BACKGROUND: The efficacy of clinical islet transplanta- tion has been demonstrated with autografts, and although islet allografts have established insulin independence in a small number of IDDM patients, the treatment...BACKGROUND: The efficacy of clinical islet transplanta- tion has been demonstrated with autografts, and although islet allografts have established insulin independence in a small number of IDDM patients, the treatment is con- founded by the necessity of central cell damage immuno- suppression, the lack of donor tissue, and recurring islet immunogenicity. These limitations underscore a need to develop therapies to serve the large population of diabetic patients. This study was designed to document central cell damage to isolated islets of Langerhans in hamsters and its prevention. METHODS: Islets were cultured at 37 °C for 7-14 days after isolation, and then at 26 °C for 2,4 and 7 days before addi- tional culture at 37 °C for an additional 7 days. Central cell damage in the isolated islets was monitored by video-mi- croscopy and analyzed quantitatively by a computer-assis- ted image analysis system. The analysis included daily measurement of the diameter and the area of the isolated is- lets and the area of the central cell damage that developed in those islets over time during culture. Histological exami- nation and TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay were used to characterize cell damage and to monitor islet function. RESULTS; Microscopic analysis showed that during the 7 to 14 days of culture at 37 °C, central cell damage appeared in the larger islets with diameters greater than 200 μm, which included both necrotic and apoptotic cell death. Low temperature (26 °C) culture prevented central cell damage of isolated islets. The 7-day culture procedure at 26 °C could inhibit most of the central cell ( excluding diameters greater than 300 μm) damage when the islets were re- warmed to 37 °C. CONCLUSIONS: Our results indicate that central cell da- mage to isolated islets of Langerhans correlates with the size of the islets. Low temperature (26 °C) culture can preventcentral cell damage to the isolated islets, and is capable to successfully precondition these islets for 37 °C culture. These novel findings may help to understand the patho- physiology of early loss of islet tissue after transplantation, and may provide a new strategy to improve graft function in the clinical setting of islet transplantation.展开更多
AIM: To study the core cell damage in isolated islets of Langerhans and its prevention by low temperature preconditioning (26 ℃).METHODS: Islets were cultured at 37 ℃ for 7-14 d after isolation, and then at 26 ℃ fo...AIM: To study the core cell damage in isolated islets of Langerhans and its prevention by low temperature preconditioning (26 ℃).METHODS: Islets were cultured at 37 ℃ for 7-14 d after isolation, and then at 26 ℃ for 2, 4 and 7 d before additional culture at 37 ℃ for another 7 d. Core cell damage in the isolated islets was monitored by video-microscopy and analyzed quantitatively by use of a computer-assisted image analysis system. The analysis included daily measurement of the diameter and the area of the isolated islets and the area of the core cell damage that developed in those islets over time during culture. Histology and TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay were used to characterize the cell damage and to monitor islet function.RESULTS: Microscopic analysis showed that during the 7 to 14 d of culture at 37 ℃, core cell damage occurred in the larger islets with diameters ＞200 μm, which included both necrotic and apoptotic cell death. Low temperature (26 ℃) culture could prevent core cell damage of isolated islets. The 7-d culture procedure at 26 ℃ could inhibit most of the core cell (excluding diameters＞300 μm) damages when the islets were re-warmed at 37 ℃.CONCLUSION: Our results indicate that core cell damage within isolated islets of Langerhans correlates with the size of islets. Low temperature (26 ℃) culture can prevent core cell damage in isolated islets, and successfully precondition these islets for incubation at 37 ℃. These novel findings may help to understand the pathophysiology of early loss of islet tissue after transplantation, and may provide a new strategy to improve graft function in the clinical setting of islet transplantation.展开更多
Erdheim-Chester Disease (ECD) is a rare condition and has various differential diagnoses with other forms of histiocytosis, classified as one of non-Langerhans histiocytosis. The diagnosis of this condition remains ch...Erdheim-Chester Disease (ECD) is a rare condition and has various differential diagnoses with other forms of histiocytosis, classified as one of non-Langerhans histiocytosis. The diagnosis of this condition remains challenging because its presentation includes non-specific systemic manifestations that can affect different organs caused by deposition of lipids and fibrosis. Most common include bone pain followed by progressive weakness and different lung manifestations. This case is about a rare presentation of ECD with Langerhans Histiocytosis as overlap syndrome, with findings of both diseases in a middle aged woman that presented dyspnea as the first symptom. The patient was treated initially as heart failure and remained without any improvement, being admitted to investigate. After a stricted follow-up, bone and lung involvement were noticed and a skin biopsy unveiled xanthomatized macrophages accompanied by Touton giant cells. This condition remains an important clinical entity and should provide new insights for clinicians dealing with respiratory diseases.展开更多
Chronic pancreatitis (CP) is a progressive inflammatory disorder of the pancreas. It is predominantly idiopathic (with an unknown cause) in India and mostly due to alcohol in the West. Diabetes that occur secondary to...Chronic pancreatitis (CP) is a progressive inflammatory disorder of the pancreas. It is predominantly idiopathic (with an unknown cause) in India and mostly due to alcohol in the West. Diabetes that occur secondary to chronic pancreatitis (T3c Diabetes) is often brittle, and is difficult to attain normoglycemia with conventional treatment requiring multiple doses of insulin. Mild and severe model of CP was induced in mice by repeated intraperitoneal injections of cerulein and L-arginine respectively with an intent to study islet dysfunction and develop therapeutic strategy in animal models of CP. Dietary intervention of epigallocatechin-3-gallate (EGCG) was tested in both the models of CP for its beneficial effects on insulin secretory functions. Pancreata collected upon euthanasia were used to study alterations in the morphology of pancreatic parenchyma and inflammation by staining with H&E and fibrotic changes by Masson’s trichrome and picrosirius staining. Insulin secretory functions of islets were evaluated to test the efficacy of the dietary intervention on β-cell functions. Intraperitoneal glucose tolerance test was performed to monitor the glucose homeostasis before and after the dietary intervention. Both the models resulted in CP with dispersed acini, inflammation and fibrosis. The loss of acini and extent of fibrosis was more in L-arginine model. 2-fold improvement in glucose-stimulated insulin secretory functions of islets was observed with 0.5% EGCG dietary intervention in cerulein model of CP and 1.6-fold in L-arginine model of CP. A further improvement in insulin secretion by 3.2-fold was observed with additional dietary supplements like N-acetyl cysteine, curcumin in combination with EGCG. Our results thus demonstrate and highlight the therapeutic potential of dietary green tea (EGCG) supplementation in reversing islet dysfunction and improving glucose homeostasis in experimental chronic pancreatitis in mice.展开更多
Type 1 diabetes mellitus(T1DM) lacks insulin secretion due to autoimmune deficiency of pancreaticβ-cells.Protecting pancreatic islets and enhancing insulin secretion has been therapeutic approaches.Mannogalactoglucan...Type 1 diabetes mellitus(T1DM) lacks insulin secretion due to autoimmune deficiency of pancreaticβ-cells.Protecting pancreatic islets and enhancing insulin secretion has been therapeutic approaches.Mannogalactoglucan is the main type of polysaccharide from natural mushroom,which has potential medicinal prospects.Nevertheless,the antidiabetic property of mannogalactoglucan in T1DM has not been fully elucidated.In this study,we obtained the neutral fraction of alkali-soluble Armillaria mellea polysaccharide(AAMP-N) with the structure of mannogalactoglucan from the fruiting body of A.mellea and investigated the potential therapeutic value of AAMP-N in T1DM.We demonstrated that AAMP-N lowered blood glucose and improved diabetes symptoms in T1DM mice.AAMP-N activated unfolded protein response(UPR) signaling pathway to maintain ER protein folding homeostasis and promote insulin secretion in vivo.Besides that,AAMP-N promoted insulin synthesis via upregulating the expression of transcription factors,increased Ca^(2+) signals to stimulate intracellular insulin secretory vesicle transport via activating calcium/calmodulin-dependent kinase Ⅱ(CamkⅡ) and cAMP/PKA signals,and enhanced insulin secretory vesicle fusion with the plasma membrane via vesicle-associated membrane protein 2(VAMP2).Collectively,these studies demonstrated that the therapeutic potential of AAMP-N on pancreatic islets function,indicating that mannogalactoglucan could be natural nutraceutical used for the treatment of T1DM.展开更多
The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted.The number of people living with diabetes m...The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted.The number of people living with diabetes mellitus is currently approaching half a billion,hence the crucial relevance of new methods to stimulate regeneration of the insulin-secretingβ-cells of the islets of Langerhans.Natural restrictions on the islet regeneration are very tight;nevertheless,the islets are capable of physiological regeneration viaβ-cell self-replication,direct differentiation of multipotent progenitor cells and spontaneousα-toβ-orδ-toβ-cell conversion(trans-differentiation).The existing preclinical models ofβ-cell dysfunction or ablation(induced surgically,chemically or genetically)have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its stimulation.The ultimate goal,sufficient level of functional activity ofβ-cells or their substitutes can be achieved by two prospective broad strategies:β-cell replacement andβ-cell regeneration.The“regeneration”strategy aims to maintain a preserved population ofβ-cells through in situ exposure to biologically active substances that improveβ-cell survival,replication and insulin secretion,or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β-toβ-cell conversion.The“replacement”strategy implies transplantation ofβ-cells(as non-disintegrated pancreatic material or isolated donor islets)orβ-like cells obtained ex vivo from progenitors or mature somatic cells(for example,hepatocytes orα-cells)under the action of small-molecule inducers or by genetic modification.We believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally activeβ-cells,the innermost hope of millions of people globally.展开更多
At present, proven clinical treatments but no cures are available for diabetes, a global epidemic with a huge economic burden. Transplantation of islets ofLangerhans by their infusion into vascularized organs is an ex...At present, proven clinical treatments but no cures are available for diabetes, a global epidemic with a huge economic burden. Transplantation of islets ofLangerhans by their infusion into vascularized organs is an experimental clinical protocol, the first approach to attain cure. However, it is associated with lifelong use of immunosuppressants. To overcome the need for immunosuppression, islets are encapsulated and separated from the host immune system by a permselective membrane. The lead material for this application is alginate which was tested in many animal models and a few clinical trials. This review discusses all aspects related to the function of transplanted encapsulated islets such as the basic requirements from a permselective membrane(e.g., allowable hydrodynamic radii, implications of the thickness of the membrane and relative electrical charge). Another aspect involves adequate oxygen supply, which is essential for survival/performance of transplanted islets, especially when using large retrievable macrocapsules implanted in poorly oxygenated sites like the subcutis. Notably, islets can survive under low oxygen tension and are physiologically active at > 40 Torr. Surprisingly, when densely crowded, islets are fully functional under hyperoxic pressure of up to 500 Torr(> 300% of atmospheric oxygen tension). The review also addresses an additional category of requirements for optimal performance of transplanted islets, named auxiliary technologies. These include control of inflammation, apoptosis, angiogenesis, and the intra-capsular environment. The review highlights that curing diabetes with a functional bio-artificial pancreas requires optimizing all of these aspects, and that significant advances have already been made in many of them.展开更多
AIM: To identify the decreasing effect of xenotransplantion in combination with privileged sites on rejection and death of biological semipermeable membrane-(BSM) encapsulated implanted islets.METHODS: After the BSM e...AIM: To identify the decreasing effect of xenotransplantion in combination with privileged sites on rejection and death of biological semipermeable membrane-(BSM) encapsulated implanted islets.METHODS: After the BSM experiment in vitro, BSMencapsulated SD rat's islet-like cell clusters (ICCs) were xenotransplanted into normal dog's brain. Morphological changes were observed under light and transmission electron microscope. The islets and apoptosis of implanted B cells were identified by insulin-TUNEL double staining.RESULTS: The BSM used in our study had a favorable permeability, some degree of rigidity, lighter foreign body reaction and toxicity. The grafts consisted of epithelioid cells and loose connective tissue. Severe infiltration of inflammatory cells was not observed. The implanted ICCs were identified 2 mo later and showed typical apoptosis.CONCLUSION: BSM xenotransplantation in combination with the privileged site can inhibit the rejection of implanted heterogeneous ICCs, and death of implanted heterogeneous B cells is associated with apoptosis.展开更多
Although allogeneic islet transplantation can successfully cure type 1 diabetes,it has limited applicability.For example,organs are in short supply;several human pancreas donors are often needed to treat one diabetic ...Although allogeneic islet transplantation can successfully cure type 1 diabetes,it has limited applicability.For example,organs are in short supply;several human pancreas donors are often needed to treat one diabetic recipient;the intrahepatic site may not be the most appropriate site for islet implantation;and immunosuppressive regimens,which are associated with side effects,are often required to prolong survival of the islet graft.An alternative source of insulinproducing cells would therefore be of major interest.Pigs represent a possible alternative source of beta cells.Grafting of pig islets may appear difficult because of the immunologic species barrier,but pig islets have been shown to function in primates for at least 6 mo with clinically incompatible immunosuppression.Therefore,a bioartificial pancreas made of encapsulated pig islets may resolve issues associated with islet allotransplantation.Although several groups have shown that encapsulated pig islets are functional in small-animal models,less is known about the use of bioartificial pancreases in large-animal models.In this review,we summarize current knowledge of encapsulated pig islets,to determine obstacles to implantation in humans and possible solutions to overcome these obstacles.展开更多
BACKGROUND The common computed tomography findings of pulmonary Langerhans cell histiocytosis (PLCH) are multiple cysts and micronodules predominantly in middle to upper lung lobes.Non-cystic nodules and large nodules...BACKGROUND The common computed tomography findings of pulmonary Langerhans cell histiocytosis (PLCH) are multiple cysts and micronodules predominantly in middle to upper lung lobes.Non-cystic nodules and large nodules are atypical findings of PLCH.CASE SUMMARY The patient was a 48-year-old Japanese man with a smoking history (20 cigarettes/d,28 years) and no symptoms.Multiple nodules existed in all lung lobes,predominantly in the right lower lobe.Some nodules seemed to be distributed randomly,and others were adjacent to bronchus.Most nodules were solid;some small ones were cystic.The largest nodule was 22 mm in diameter.Although metastatic lung tumors were suspected,thoracoscopic lung biopsy led to the diagnosis of PLCH.At 6 months after he quit smoking,all nodules had almost disappeared.We investigated the characteristics of nodules at diagnosis in detail.Of 349 nodules in total,116 were in upper and 199 were in lower lobes.Ninety-six (27.5%) were cystic;the remaining 253 (72.5%) were non-cystic.The prevalence of cystic nodules was higher in upper lobes than in lower lobes (right upper 37.5% vs lower 18.2%,P = 0.0068;left upper 48.1% vs lower 24.4%,P = 0.0078).The average size (dia.) of cystic nodules was smaller than that of noncystic nodules (5.03 mm vs 7.40 mm,respectively,P < 0.0001).CONCLUSION Although multiple non-cystic nodules including large nodules (over 20 mm) are atypical,PLCH should be included in differential diagnoses.The presence of small cystic nodules predominantly in upper lobes and asymptomatic situation are also important for differential diagnoses to distinguish from metastatic cancers.展开更多
AIM: To investigate the influence of heme oxygenase-1 (HO-1) gene transfer on the viability and function of cultured rat islets in vitro. METHODS: Islets were isolated from the pancreata of Sprague-Dawley rats by intr...AIM: To investigate the influence of heme oxygenase-1 (HO-1) gene transfer on the viability and function of cultured rat islets in vitro. METHODS: Islets were isolated from the pancreata of Sprague-Dawley rats by intraductal collagenase diges- tion, and purified by discontinuous Ficoll density gradient centrifugation. Purified rat islets were transfected with adenoviral vectors containing human HO-1 gene (Ad- HO-1) or enhanced green fluorescent protein gene (Ad- EGFP), and then cultured for seven days. Transfection was confirmed by fluorescence microscopy and Western blot. Islet viability was evaluated by acridine orange/ propidium iodide fluorescent staining. Glucose-stimulated insulin release was detected using insulin radioimmuno- assay kits and was used to assess the function of islets. Stimulation index (SI) was calculated by dividing the insulin release upon high glucose stimulation by the insulin release upon low glucose stimulation. RESULTS: After seven days culture, the viability of cultured rat islets decreased significantly (92% ± 6% vs 52% ± 13%, P < 0.05), and glucose-stimulated insulin release also decreased significantly (6.47 ± 0.55 mIU/ L/30IEQ vs 4.57 ± 0.40 mIU/L/30IEQ, 14.93 ± 1.17 mIU/L/30IEQ vs 9.63 ± 0.71 mIU/L/30IEQ, P < 0.05). Transfection of rat islets with adenoviral vectors at an MOI of 20 was efficient, and did not impair islet function. At 7 d post-transfection, the viability of Ad-HO-1 transfected islets was higher than that of control islets(71% ± 15% vs 52% ± 13%, P < 0.05). There was no significant difference in insulin release upon low glucose stimulation (2.8 mmol/L) among Ad-HO-1 transfected group, Ad-EGFP transfected group, and control group (P > 0.05), while when stimulated by high glucose (16.7 mmol/L) solution, insulin release in Ad-HO-1 transfected group was significantly higher than that in Ad-EGFP transfected group and control group, respectively (12.50 ± 2.17 mIU/L/30IEQ vs 8.87 ± 0.65 mIU/L/30IEQ; 12.50 ± 2.17 mIU/L/30IEQ vs 9.63 ± 0.71 mIU/L/30IEQ, P < 0.05). The SI of Ad-HO-1 transfected group was also significantly higher than that of Ad-EGFP transfected group and control group, respectively (2.21 ± 0.02 vs 2.08 ± 0.05; 2.21 ± 0.02 vs 2.11 ± 0.03, P < 0.05). CONCLUSION: The viability and function of rat islets decrease over time in in vitro culture, and heme oxygenase-1 gene transfer could improve the viability and function of cultured rat islets.展开更多
AIM: To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS: Primary rat islets were isolated from male Sprague-Dawley rats by collage...AIM: To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS: Primary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations (1,3,10 and 30 μmol/L) of berberine or 1 μmol/L Glibenclamide (GB) for 24 h. Glucose-stimulated insulin secretion (GSIS) assay was conducted and insulin was determined by radioimmunoassay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha (HNF4α) was determined by reverse transcription polymerase chain reaction (RT-PCR). Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4α in the islets. Glucokinase (GK) activity was measured by spectrophotometric method. RESULTS: Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 μmol/L. Both mRNA and protein expressions of HNF4α were up-regulated by berberine in a dose-dependent manner,and GK activity was also increased accordingly. However,GB demonstrated no regulatory effects on HNF4α expression or GK activity. CONCLUSION: Berberine can enhance GSIS in rat islets,and probably exerts the insulinotropic effect via a pathway involving HNF4α and GK,which is distinct from sulphonylureas (SUs).展开更多
The brain parenchymal Langerhans cell histiocytosis(LCH) without systemic disease or lytic skull lesions is extremely rare. We report a 23-year-old male presenting with new onset 1 hour seizure with loss of consciousn...The brain parenchymal Langerhans cell histiocytosis(LCH) without systemic disease or lytic skull lesions is extremely rare. We report a 23-year-old male presenting with new onset 1 hour seizure with loss of consciousness 20 days prior to admission, and recurrent seizure 2 weeks later. Brain magnetic resonance imaging(MRI) showed an irregularly mass with enhancement involving the right frontal lobe. Microscopically, the lesion was characterized by sheets of Langerhans cells in addition to reactive inflammatory elements. Immunohistochemically, Langerhans cells were positive for Langerin, CD1a and S-100 protein. The patient received no chemotherapy or radiotherapy after surgery. After 24 months of follow-up, no recurrence or other systemic lesions were observed. Although there is no standard treatment for solitary cerebral LCH, the prognosis generally appears to be good.展开更多
Objective: Langerhans cell histiocytosis (LCH) has been well described only in children. We analyzed the characteristics, reactivation, and outcome of LCH in a cohort of 55 patients across all ages. Methods: We review...Objective: Langerhans cell histiocytosis (LCH) has been well described only in children. We analyzed the characteristics, reactivation, and outcome of LCH in a cohort of 55 patients across all ages. Methods: We reviewed the records of all patients with LCH treated at a single institute between Jan. 1974 and May 1998. Results: The 55 patients were 2 to 67 years of age (median, 31 years) at the time of diagnosis, and 85.5% were male. Forty patients (72.7%) had single-system LCH; Fifteen (27.3%) had multisystem disease. The head and neck was the most frequent tumor site (63.6%). LCH was not found in organs at risk of involvement (liver, spleen, bone marrow, and lungs). The frequency of bony invasion (23.6% overall) differed significantly according to age ≤15 years (66.7%) vs. age >15 years (11.6%) (P=0.0005). At a median follow-up of 12 years, no patient died of LCH. The 5, 10-year survival estimates were 100%. The 5, 10-year disease-free survival estimates were 70.9% and 58.4%. The 5-year disease-free survival estimate was 58.3% for age ≤ 15 years vs. 74.4% for age >15 years (P=0.83) and 75% for single-system disease vs. 60% for multisystem disease (P=0.13). LCH was reactivated in 43.6% of patients, with a median of 14 months (range, 2-180 months). Three patients with recurrent disease experienced spontaneous remission. At the time of the most recent follow-up, 23.6% of survivors had active disease. Conclusion: LCH is not found exclusively in children and adolescents. The frequency of bone invasion is inversely related to age. Reactivation is very common regardless of the type of treatment, but the prognosis is generally good.展开更多
Because insulin released by the β-cells of pancreatic islets is the main regulator of glucose levels, the quantitative modeling of their glucose-stimulated insulin secretion is of obvious interest not only to improve...Because insulin released by the β-cells of pancreatic islets is the main regulator of glucose levels, the quantitative modeling of their glucose-stimulated insulin secretion is of obvious interest not only to improve our understanding of the processes involved, but also to allow better assessment of β -cell function in diabetic patients or islet transplant recipients as well as the development of improved artificial or bioartificial pancreas devices. We have recently developed a general, local concentrations-based multiphysics computational model of insulin secretion in avascular pancreatic islets that can be used to calculate insulin secretion for arbitrary geometries of cultured, perifused, transplanted, or encapsulated islets in response to various glucose profiles. Here, experimental results obtained from two different dynamic glucose-stimulated insulin release (GSIR) perifusion studies performed by us following standard procedures are compared to those calculated by the model. Such perifusion studies allow the quantitative assessment of insulin release kinetics under fully controllable experimental conditions of varying external concentrations of glucose, oxygen, or other compounds of interest, and can provide an informative assessment of islet quality and function. The time-profile of the insulin secretion calculated by the model was in good agree- ment with the experimental results obtained with isolated human islets. Detailed spatial distributions of glucose, oxygen, and insulin were calculated and are presented to provide a quantitative visualization of various important aspects of the insulin secretion dynamics in perifused islets.展开更多
AIM: To determine whether the elevated vascular endothelial growth factor (VEGF) expression produced by the transfected vascular endothelial cells (VECs) could stimulate angiogenesis of the graft islets and exert its ...AIM: To determine whether the elevated vascular endothelial growth factor (VEGF) expression produced by the transfected vascular endothelial cells (VECs) could stimulate angiogenesis of the graft islets and exert its effect on the graft function. METHODS: Thirty diabetic recipient rats were divided into three groups (n = 10 per group). In the control group,300 IEQ islets were transplanted in each rat under the capsule of the right kidney,which were considered as marginal grafts. In the VEC group,VEC together with the islets were transplanted in each rat. In the VEGF group,VEC transfected by pIRES2-EGFP/ VEGF165 plasmid and the islets were transplanted in each rat. Blood glucose and insulin levels were evaluated every other day after operation. Intravenous glucose tolerance test (IVGTT) was performed 10 d after the transplantation. Hematoxylin and eosin (HE) staining was used to evaluate the histological features of the graft islets. Immunohistochemical staining was used to detect insulin-6,VEGF and CD34 (MVD) expression in the graft islets. RESULTS: Blood glucose and insulin levels in the VEGF group restored to normal 3 d after transplantation. In contrast,diabetic rats receiving the same islets with or without normal VECs displayed moderate hyperglycemia and insulin,without a significant difference between these two groups. IVGTT showed that both the amplitude of blood glucose induction and the kinetics of blood glucose in the VEGF group restored to normal after transplantation. H&E and immunohistochemical staining showed the presence of a large amount of graft islets under the capsule of the kidney,which were positively stained with insulin-6 and VEGF antibodies in the VEGF group. In the cell masses,CD34-stained VECs were observed. The similar masses were also seen in the other two groups,but with a fewer positive cells stained with insulin-6 and CD34 antibodies. No VEGF-positive cells appeared in these groups. Microvessel density (MVD) was significantly higher in the VEGF group compared to the other two groups. CONCLUSION: Elevated VEGF production by trans-fected vascular endothelial cells in the site of islet transplantation stimulates angiogenesis of the islet grafts. The accelerated islet revascularization in early stage could improve the outcome of islet transplantation,and enhance the graft survival.展开更多
Objectives Langerhans' Cell histiocytosis (LCH) is a rare disease, which remains poorly understood and whose cellular origin remains unknown. To increase understanding of temporal bone LCH, it is necessary to stud...Objectives Langerhans' Cell histiocytosis (LCH) is a rare disease, which remains poorly understood and whose cellular origin remains unknown. To increase understanding of temporal bone LCH, it is necessary to study recent advances in the diagnosis and treatment of this disease. Methods The long term(5 to 30 years) results of 21 temporal bone LCH cases treated between 1973 and 2003 were reviewed. Surgery, radiotherapy, pharmacologic therapy or a combination of these treatments were employed in these cases. Results Eighteen patients were cured(18/21, 85%). Six patients developed residual diabetes insipidus (DI) and dwarfism (28%). Three patients died(14%). Conclusions The Alessi classification system for LCH based on the extent of disease accurately predicts prognosis and is a useful guide in selecting treatment methodologies. X-ray, computed tomography and magnetic resonance imaging have proved useful in defining the extent of osseous and soft tissue diseases. Diagnosis of LCH is based on clinical presentations, radiographic findings and histopathological results. Surgery and radiotherapy are the main treatment modalities. Pharmacologic therapy should be used in patients with aggressive, disseminate, and refractory lesions. LCH has a predilection for children and prognosis depends on age and extent of vital organ involvement.展开更多
Langerhans cell histiocytosis (LCH) is a group of idiopathic disorders characterized by the proliferation of specialized,bone marrow-derived langerhans cells and mature eosinophils.The clinical spectrum ranges from an...Langerhans cell histiocytosis (LCH) is a group of idiopathic disorders characterized by the proliferation of specialized,bone marrow-derived langerhans cells and mature eosinophils.The clinical spectrum ranges from an acute,fulminant,disseminated disease called LettererSiwe disease to solitary or few,indolent and chronic lesions of the bone or other organs called eosinophilic granuloma.Involvement of the gastrointestinal tract is very rare in LCH.We present the case of a 53-yearold woman referred by her primary care physician for a screening colonoscopy.A single sessile polyp,measuring 4 mm in size,was found in the rectum.Histopathological examination revealed that the lesion was relatively well circumscribed and comprised mainly a mixture of polygonal cells with moderate-to-abundant pink slightly granular cytoplasm.The nuclei within these cells had frequent grooves and were occasionally folded.Immunohistochemical staining was positive for CD1a which confirmed the diagnosis of LCH.On further workup,there was no evidence of involvement of any other organ.On follow up colonoscopy one year later,there was no evidence of disease recurrence.Review of the published literature revealed that LCH presenting as solitary colonic polyp is rare.However,with the increas-ing rates of screening colonoscopy,more colonic polyps may be identified as LCH on histopathology.This underscores the importance of recognizing this rare condition and ensuring proper follow-up to rule out systemic disease.展开更多
Purpose:Ocular trauma occurs disproportionately in children on an annual basis.However,because of this frequency,other diagnoses,.such as orbital neoplasms,.can easily be ignored.Methods:We report on a two-year-old bo...Purpose:Ocular trauma occurs disproportionately in children on an annual basis.However,because of this frequency,other diagnoses,.such as orbital neoplasms,.can easily be ignored.Methods:We report on a two-year-old boy who presented with a dark purple,irregularly shaped lesion on his lower left eyelid.The patient had suffered injuries twice to that area.Results:Axial computed tomography images demonstrated an ill-defined and inhomogeneous soft tissue mass in the lateral and posterior region of the left orbit,.with bony destruction and absorption of the adjacent orbital wall..Magnetic resonance imaging of the orbit showed a lesion involving the greater sphenoidal wing,the supraorbital wall,and the frontal area.Enlarged nuchal and inguinal lymph nodes were detected by sonographic examination.Histopathological examination of a surgical biopsy showed an accumulation of characteristic Langerhans cells.The diagnosis of Langerhans cell histiocytosis was confirmed by immunohistochemical examinations positive for CD1a and SP-100.Conclusion:Orbital Langerhans cell histiocytosis is rarely encountered in ophthalmic practice,.so the ophthalmologist needs to be familiar with its presentation and work-up,.and has to be aware of possible OLCH diagnosis when a child(or even an adult)presents with prolonged and persistent eyelid edema,.even with a history of ocular trauma.展开更多
Damped wave diffusion effects during oxygen transport in islets of Langerhans is studied. Simultaneous reaction and diffusion models were developed. The asymptotic limits of first and zeroth order in Michaelis and Men...Damped wave diffusion effects during oxygen transport in islets of Langerhans is studied. Simultaneous reaction and diffusion models were developed. The asymptotic limits of first and zeroth order in Michaelis and Menten kinetics was used in the study. Parabolic Fick diffusion and hyperbolic damped wave diffusion were studied separately. Method of relativistic transformation was used in order to obtain the solution for the hyperbolic model. Model solutions was used to obtain mass inertial times. Convective boundary condition was used. Sharma number (mass) may be used in evaluating the importance of the damped wave diffusion process in relation to other processes such as convection, Fick steady diffusion in the given application. Four regimes can be identified in the solution of hyperbolic damped wave diffusion model. These are;1) Zero Transfer Inertial Regime, 0 0≤τ≤τinertia;2) Rising Regime during times greater than inertial regime and less than at the wave front, Xp > τ, 3) at Wave front , τ = Xp;4) Falling Regime in open Interval, of times greater than at the wave front, τ > Xp. Method of superposition of steady state concentration and transient concentration used in both solutions of parabolic and hyperbolic models. Expression for steady state concentration developed. Closed form analytic model solutions developed in asymptotic limits of Michaelis and Menten kinetic at zeroth order and first order. Expression for Penetration Length Derived-Hypoxia Explained. Expression for Inertial Lag Time Derived. Solution was obtained by the method of separation of variables for transient for parabolic model and by the method of relativistic transformation for hyperbolic models. The concentration profile was expressed as a sum of steadty state and transient parts.展开更多
文摘BACKGROUND: The efficacy of clinical islet transplanta- tion has been demonstrated with autografts, and although islet allografts have established insulin independence in a small number of IDDM patients, the treatment is con- founded by the necessity of central cell damage immuno- suppression, the lack of donor tissue, and recurring islet immunogenicity. These limitations underscore a need to develop therapies to serve the large population of diabetic patients. This study was designed to document central cell damage to isolated islets of Langerhans in hamsters and its prevention. METHODS: Islets were cultured at 37 °C for 7-14 days after isolation, and then at 26 °C for 2,4 and 7 days before addi- tional culture at 37 °C for an additional 7 days. Central cell damage in the isolated islets was monitored by video-mi- croscopy and analyzed quantitatively by a computer-assis- ted image analysis system. The analysis included daily measurement of the diameter and the area of the isolated is- lets and the area of the central cell damage that developed in those islets over time during culture. Histological exami- nation and TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay were used to characterize cell damage and to monitor islet function. RESULTS; Microscopic analysis showed that during the 7 to 14 days of culture at 37 °C, central cell damage appeared in the larger islets with diameters greater than 200 μm, which included both necrotic and apoptotic cell death. Low temperature (26 °C) culture prevented central cell damage of isolated islets. The 7-day culture procedure at 26 °C could inhibit most of the central cell ( excluding diameters greater than 300 μm) damage when the islets were re- warmed to 37 °C. CONCLUSIONS: Our results indicate that central cell da- mage to isolated islets of Langerhans correlates with the size of the islets. Low temperature (26 °C) culture can preventcentral cell damage to the isolated islets, and is capable to successfully precondition these islets for 37 °C culture. These novel findings may help to understand the patho- physiology of early loss of islet tissue after transplantation, and may provide a new strategy to improve graft function in the clinical setting of islet transplantation.
基金Supported by the National Natural Science Foundation of China, No.30271274 German DAAD-Wong Kuan Cheng Fellowship
文摘AIM: To study the core cell damage in isolated islets of Langerhans and its prevention by low temperature preconditioning (26 ℃).METHODS: Islets were cultured at 37 ℃ for 7-14 d after isolation, and then at 26 ℃ for 2, 4 and 7 d before additional culture at 37 ℃ for another 7 d. Core cell damage in the isolated islets was monitored by video-microscopy and analyzed quantitatively by use of a computer-assisted image analysis system. The analysis included daily measurement of the diameter and the area of the isolated islets and the area of the core cell damage that developed in those islets over time during culture. Histology and TdT-mediated dUTP-biotin nick end labeling (TUNEL) assay were used to characterize the cell damage and to monitor islet function.RESULTS: Microscopic analysis showed that during the 7 to 14 d of culture at 37 ℃, core cell damage occurred in the larger islets with diameters ＞200 μm, which included both necrotic and apoptotic cell death. Low temperature (26 ℃) culture could prevent core cell damage of isolated islets. The 7-d culture procedure at 26 ℃ could inhibit most of the core cell (excluding diameters＞300 μm) damages when the islets were re-warmed at 37 ℃.CONCLUSION: Our results indicate that core cell damage within isolated islets of Langerhans correlates with the size of islets. Low temperature (26 ℃) culture can prevent core cell damage in isolated islets, and successfully precondition these islets for incubation at 37 ℃. These novel findings may help to understand the pathophysiology of early loss of islet tissue after transplantation, and may provide a new strategy to improve graft function in the clinical setting of islet transplantation.
文摘Erdheim-Chester Disease (ECD) is a rare condition and has various differential diagnoses with other forms of histiocytosis, classified as one of non-Langerhans histiocytosis. The diagnosis of this condition remains challenging because its presentation includes non-specific systemic manifestations that can affect different organs caused by deposition of lipids and fibrosis. Most common include bone pain followed by progressive weakness and different lung manifestations. This case is about a rare presentation of ECD with Langerhans Histiocytosis as overlap syndrome, with findings of both diseases in a middle aged woman that presented dyspnea as the first symptom. The patient was treated initially as heart failure and remained without any improvement, being admitted to investigate. After a stricted follow-up, bone and lung involvement were noticed and a skin biopsy unveiled xanthomatized macrophages accompanied by Touton giant cells. This condition remains an important clinical entity and should provide new insights for clinicians dealing with respiratory diseases.
文摘Chronic pancreatitis (CP) is a progressive inflammatory disorder of the pancreas. It is predominantly idiopathic (with an unknown cause) in India and mostly due to alcohol in the West. Diabetes that occur secondary to chronic pancreatitis (T3c Diabetes) is often brittle, and is difficult to attain normoglycemia with conventional treatment requiring multiple doses of insulin. Mild and severe model of CP was induced in mice by repeated intraperitoneal injections of cerulein and L-arginine respectively with an intent to study islet dysfunction and develop therapeutic strategy in animal models of CP. Dietary intervention of epigallocatechin-3-gallate (EGCG) was tested in both the models of CP for its beneficial effects on insulin secretory functions. Pancreata collected upon euthanasia were used to study alterations in the morphology of pancreatic parenchyma and inflammation by staining with H&E and fibrotic changes by Masson’s trichrome and picrosirius staining. Insulin secretory functions of islets were evaluated to test the efficacy of the dietary intervention on β-cell functions. Intraperitoneal glucose tolerance test was performed to monitor the glucose homeostasis before and after the dietary intervention. Both the models resulted in CP with dispersed acini, inflammation and fibrosis. The loss of acini and extent of fibrosis was more in L-arginine model. 2-fold improvement in glucose-stimulated insulin secretory functions of islets was observed with 0.5% EGCG dietary intervention in cerulein model of CP and 1.6-fold in L-arginine model of CP. A further improvement in insulin secretion by 3.2-fold was observed with additional dietary supplements like N-acetyl cysteine, curcumin in combination with EGCG. Our results thus demonstrate and highlight the therapeutic potential of dietary green tea (EGCG) supplementation in reversing islet dysfunction and improving glucose homeostasis in experimental chronic pancreatitis in mice.
基金funded by the National Natural Science Foundation of China (32371341,31872674)the Scientific and Technologic Foundation of Jilin Province (20230202050NC)the Fundamental Research Funds for the Central Universities (CGZH202206)。
文摘Type 1 diabetes mellitus(T1DM) lacks insulin secretion due to autoimmune deficiency of pancreaticβ-cells.Protecting pancreatic islets and enhancing insulin secretion has been therapeutic approaches.Mannogalactoglucan is the main type of polysaccharide from natural mushroom,which has potential medicinal prospects.Nevertheless,the antidiabetic property of mannogalactoglucan in T1DM has not been fully elucidated.In this study,we obtained the neutral fraction of alkali-soluble Armillaria mellea polysaccharide(AAMP-N) with the structure of mannogalactoglucan from the fruiting body of A.mellea and investigated the potential therapeutic value of AAMP-N in T1DM.We demonstrated that AAMP-N lowered blood glucose and improved diabetes symptoms in T1DM mice.AAMP-N activated unfolded protein response(UPR) signaling pathway to maintain ER protein folding homeostasis and promote insulin secretion in vivo.Besides that,AAMP-N promoted insulin synthesis via upregulating the expression of transcription factors,increased Ca^(2+) signals to stimulate intracellular insulin secretory vesicle transport via activating calcium/calmodulin-dependent kinase Ⅱ(CamkⅡ) and cAMP/PKA signals,and enhanced insulin secretory vesicle fusion with the plasma membrane via vesicle-associated membrane protein 2(VAMP2).Collectively,these studies demonstrated that the therapeutic potential of AAMP-N on pancreatic islets function,indicating that mannogalactoglucan could be natural nutraceutical used for the treatment of T1DM.
基金Supported by the President Grant for Government Support of Young Russian Scientists,No.075-15-2019-1120.
文摘The pancreas became one of the first objects of regenerative medicine,since other possibilities of dealing with the pancreatic endocrine insufficiency were clearly exhausted.The number of people living with diabetes mellitus is currently approaching half a billion,hence the crucial relevance of new methods to stimulate regeneration of the insulin-secretingβ-cells of the islets of Langerhans.Natural restrictions on the islet regeneration are very tight;nevertheless,the islets are capable of physiological regeneration viaβ-cell self-replication,direct differentiation of multipotent progenitor cells and spontaneousα-toβ-orδ-toβ-cell conversion(trans-differentiation).The existing preclinical models ofβ-cell dysfunction or ablation(induced surgically,chemically or genetically)have significantly expanded our understanding of reparative regeneration of the islets and possible ways of its stimulation.The ultimate goal,sufficient level of functional activity ofβ-cells or their substitutes can be achieved by two prospective broad strategies:β-cell replacement andβ-cell regeneration.The“regeneration”strategy aims to maintain a preserved population ofβ-cells through in situ exposure to biologically active substances that improveβ-cell survival,replication and insulin secretion,or to evoke the intrinsic adaptive mechanisms triggering the spontaneous non-β-toβ-cell conversion.The“replacement”strategy implies transplantation ofβ-cells(as non-disintegrated pancreatic material or isolated donor islets)orβ-like cells obtained ex vivo from progenitors or mature somatic cells(for example,hepatocytes orα-cells)under the action of small-molecule inducers or by genetic modification.We believe that the huge volume of experimental and clinical studies will finally allow a safe and effective solution to a seemingly simple goal-restoration of the functionally activeβ-cells,the innermost hope of millions of people globally.
文摘At present, proven clinical treatments but no cures are available for diabetes, a global epidemic with a huge economic burden. Transplantation of islets ofLangerhans by their infusion into vascularized organs is an experimental clinical protocol, the first approach to attain cure. However, it is associated with lifelong use of immunosuppressants. To overcome the need for immunosuppression, islets are encapsulated and separated from the host immune system by a permselective membrane. The lead material for this application is alginate which was tested in many animal models and a few clinical trials. This review discusses all aspects related to the function of transplanted encapsulated islets such as the basic requirements from a permselective membrane(e.g., allowable hydrodynamic radii, implications of the thickness of the membrane and relative electrical charge). Another aspect involves adequate oxygen supply, which is essential for survival/performance of transplanted islets, especially when using large retrievable macrocapsules implanted in poorly oxygenated sites like the subcutis. Notably, islets can survive under low oxygen tension and are physiologically active at > 40 Torr. Surprisingly, when densely crowded, islets are fully functional under hyperoxic pressure of up to 500 Torr(> 300% of atmospheric oxygen tension). The review also addresses an additional category of requirements for optimal performance of transplanted islets, named auxiliary technologies. These include control of inflammation, apoptosis, angiogenesis, and the intra-capsular environment. The review highlights that curing diabetes with a functional bio-artificial pancreas requires optimizing all of these aspects, and that significant advances have already been made in many of them.
基金Supported by the Natural Science Foundation of Shaanxi Province, No. 98SZ-064
文摘AIM: To identify the decreasing effect of xenotransplantion in combination with privileged sites on rejection and death of biological semipermeable membrane-(BSM) encapsulated implanted islets.METHODS: After the BSM experiment in vitro, BSMencapsulated SD rat's islet-like cell clusters (ICCs) were xenotransplanted into normal dog's brain. Morphological changes were observed under light and transmission electron microscope. The islets and apoptosis of implanted B cells were identified by insulin-TUNEL double staining.RESULTS: The BSM used in our study had a favorable permeability, some degree of rigidity, lighter foreign body reaction and toxicity. The grafts consisted of epithelioid cells and loose connective tissue. Severe infiltration of inflammatory cells was not observed. The implanted ICCs were identified 2 mo later and showed typical apoptosis.CONCLUSION: BSM xenotransplantation in combination with the privileged site can inhibit the rejection of implanted heterogeneous ICCs, and death of implanted heterogeneous B cells is associated with apoptosis.
基金Supported by European Grant Titled Xenome,UE LSHBCT-2006-037377
文摘Although allogeneic islet transplantation can successfully cure type 1 diabetes,it has limited applicability.For example,organs are in short supply;several human pancreas donors are often needed to treat one diabetic recipient;the intrahepatic site may not be the most appropriate site for islet implantation;and immunosuppressive regimens,which are associated with side effects,are often required to prolong survival of the islet graft.An alternative source of insulinproducing cells would therefore be of major interest.Pigs represent a possible alternative source of beta cells.Grafting of pig islets may appear difficult because of the immunologic species barrier,but pig islets have been shown to function in primates for at least 6 mo with clinically incompatible immunosuppression.Therefore,a bioartificial pancreas made of encapsulated pig islets may resolve issues associated with islet allotransplantation.Although several groups have shown that encapsulated pig islets are functional in small-animal models,less is known about the use of bioartificial pancreases in large-animal models.In this review,we summarize current knowledge of encapsulated pig islets,to determine obstacles to implantation in humans and possible solutions to overcome these obstacles.
文摘BACKGROUND The common computed tomography findings of pulmonary Langerhans cell histiocytosis (PLCH) are multiple cysts and micronodules predominantly in middle to upper lung lobes.Non-cystic nodules and large nodules are atypical findings of PLCH.CASE SUMMARY The patient was a 48-year-old Japanese man with a smoking history (20 cigarettes/d,28 years) and no symptoms.Multiple nodules existed in all lung lobes,predominantly in the right lower lobe.Some nodules seemed to be distributed randomly,and others were adjacent to bronchus.Most nodules were solid;some small ones were cystic.The largest nodule was 22 mm in diameter.Although metastatic lung tumors were suspected,thoracoscopic lung biopsy led to the diagnosis of PLCH.At 6 months after he quit smoking,all nodules had almost disappeared.We investigated the characteristics of nodules at diagnosis in detail.Of 349 nodules in total,116 were in upper and 199 were in lower lobes.Ninety-six (27.5%) were cystic;the remaining 253 (72.5%) were non-cystic.The prevalence of cystic nodules was higher in upper lobes than in lower lobes (right upper 37.5% vs lower 18.2%,P = 0.0068;left upper 48.1% vs lower 24.4%,P = 0.0078).The average size (dia.) of cystic nodules was smaller than that of noncystic nodules (5.03 mm vs 7.40 mm,respectively,P < 0.0001).CONCLUSION Although multiple non-cystic nodules including large nodules (over 20 mm) are atypical,PLCH should be included in differential diagnoses.The presence of small cystic nodules predominantly in upper lobes and asymptomatic situation are also important for differential diagnoses to distinguish from metastatic cancers.
基金Supported by the National Natural Science Foundation of China, No. 30571759Social Development Foundation of Shanghai, No. 200253
文摘AIM: To investigate the influence of heme oxygenase-1 (HO-1) gene transfer on the viability and function of cultured rat islets in vitro. METHODS: Islets were isolated from the pancreata of Sprague-Dawley rats by intraductal collagenase diges- tion, and purified by discontinuous Ficoll density gradient centrifugation. Purified rat islets were transfected with adenoviral vectors containing human HO-1 gene (Ad- HO-1) or enhanced green fluorescent protein gene (Ad- EGFP), and then cultured for seven days. Transfection was confirmed by fluorescence microscopy and Western blot. Islet viability was evaluated by acridine orange/ propidium iodide fluorescent staining. Glucose-stimulated insulin release was detected using insulin radioimmuno- assay kits and was used to assess the function of islets. Stimulation index (SI) was calculated by dividing the insulin release upon high glucose stimulation by the insulin release upon low glucose stimulation. RESULTS: After seven days culture, the viability of cultured rat islets decreased significantly (92% ± 6% vs 52% ± 13%, P < 0.05), and glucose-stimulated insulin release also decreased significantly (6.47 ± 0.55 mIU/ L/30IEQ vs 4.57 ± 0.40 mIU/L/30IEQ, 14.93 ± 1.17 mIU/L/30IEQ vs 9.63 ± 0.71 mIU/L/30IEQ, P < 0.05). Transfection of rat islets with adenoviral vectors at an MOI of 20 was efficient, and did not impair islet function. At 7 d post-transfection, the viability of Ad-HO-1 transfected islets was higher than that of control islets(71% ± 15% vs 52% ± 13%, P < 0.05). There was no significant difference in insulin release upon low glucose stimulation (2.8 mmol/L) among Ad-HO-1 transfected group, Ad-EGFP transfected group, and control group (P > 0.05), while when stimulated by high glucose (16.7 mmol/L) solution, insulin release in Ad-HO-1 transfected group was significantly higher than that in Ad-EGFP transfected group and control group, respectively (12.50 ± 2.17 mIU/L/30IEQ vs 8.87 ± 0.65 mIU/L/30IEQ; 12.50 ± 2.17 mIU/L/30IEQ vs 9.63 ± 0.71 mIU/L/30IEQ, P < 0.05). The SI of Ad-HO-1 transfected group was also significantly higher than that of Ad-EGFP transfected group and control group, respectively (2.21 ± 0.02 vs 2.08 ± 0.05; 2.21 ± 0.02 vs 2.11 ± 0.03, P < 0.05). CONCLUSION: The viability and function of rat islets decrease over time in in vitro culture, and heme oxygenase-1 gene transfer could improve the viability and function of cultured rat islets.
基金The National Natural Science Foundation of China,No.30500685
文摘AIM: To observe the effect of berberine on insulin secretion in rat pancreatic islets and to explore its possible molecular mechanism. METHODS: Primary rat islets were isolated from male Sprague-Dawley rats by collagenase digestion and treated with different concentrations (1,3,10 and 30 μmol/L) of berberine or 1 μmol/L Glibenclamide (GB) for 24 h. Glucose-stimulated insulin secretion (GSIS) assay was conducted and insulin was determined by radioimmunoassay. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate cytotoxicity. The mRNA level of hepatic nuclear factor 4 alpha (HNF4α) was determined by reverse transcription polymerase chain reaction (RT-PCR). Indirect immunofluorescence staining and Western blot analysis were employed to detect protein expression of HNF4α in the islets. Glucokinase (GK) activity was measured by spectrophotometric method. RESULTS: Berberine enhanced GSIS rather than basal insulin secretion dose-dependently in rat islets and showed no significant cytotoxicity on islet cells at the concentration of 10 μmol/L. Both mRNA and protein expressions of HNF4α were up-regulated by berberine in a dose-dependent manner,and GK activity was also increased accordingly. However,GB demonstrated no regulatory effects on HNF4α expression or GK activity. CONCLUSION: Berberine can enhance GSIS in rat islets,and probably exerts the insulinotropic effect via a pathway involving HNF4α and GK,which is distinct from sulphonylureas (SUs).
文摘The brain parenchymal Langerhans cell histiocytosis(LCH) without systemic disease or lytic skull lesions is extremely rare. We report a 23-year-old male presenting with new onset 1 hour seizure with loss of consciousness 20 days prior to admission, and recurrent seizure 2 weeks later. Brain magnetic resonance imaging(MRI) showed an irregularly mass with enhancement involving the right frontal lobe. Microscopically, the lesion was characterized by sheets of Langerhans cells in addition to reactive inflammatory elements. Immunohistochemically, Langerhans cells were positive for Langerin, CD1a and S-100 protein. The patient received no chemotherapy or radiotherapy after surgery. After 24 months of follow-up, no recurrence or other systemic lesions were observed. Although there is no standard treatment for solitary cerebral LCH, the prognosis generally appears to be good.
文摘Objective: Langerhans cell histiocytosis (LCH) has been well described only in children. We analyzed the characteristics, reactivation, and outcome of LCH in a cohort of 55 patients across all ages. Methods: We reviewed the records of all patients with LCH treated at a single institute between Jan. 1974 and May 1998. Results: The 55 patients were 2 to 67 years of age (median, 31 years) at the time of diagnosis, and 85.5% were male. Forty patients (72.7%) had single-system LCH; Fifteen (27.3%) had multisystem disease. The head and neck was the most frequent tumor site (63.6%). LCH was not found in organs at risk of involvement (liver, spleen, bone marrow, and lungs). The frequency of bony invasion (23.6% overall) differed significantly according to age ≤15 years (66.7%) vs. age >15 years (11.6%) (P=0.0005). At a median follow-up of 12 years, no patient died of LCH. The 5, 10-year survival estimates were 100%. The 5, 10-year disease-free survival estimates were 70.9% and 58.4%. The 5-year disease-free survival estimate was 58.3% for age ≤ 15 years vs. 74.4% for age >15 years (P=0.83) and 75% for single-system disease vs. 60% for multisystem disease (P=0.13). LCH was reactivated in 43.6% of patients, with a median of 14 months (range, 2-180 months). Three patients with recurrent disease experienced spontaneous remission. At the time of the most recent follow-up, 23.6% of survivors had active disease. Conclusion: LCH is not found exclusively in children and adolescents. The frequency of bone invasion is inversely related to age. Reactivation is very common regardless of the type of treatment, but the prognosis is generally good.
文摘Because insulin released by the β-cells of pancreatic islets is the main regulator of glucose levels, the quantitative modeling of their glucose-stimulated insulin secretion is of obvious interest not only to improve our understanding of the processes involved, but also to allow better assessment of β -cell function in diabetic patients or islet transplant recipients as well as the development of improved artificial or bioartificial pancreas devices. We have recently developed a general, local concentrations-based multiphysics computational model of insulin secretion in avascular pancreatic islets that can be used to calculate insulin secretion for arbitrary geometries of cultured, perifused, transplanted, or encapsulated islets in response to various glucose profiles. Here, experimental results obtained from two different dynamic glucose-stimulated insulin release (GSIR) perifusion studies performed by us following standard procedures are compared to those calculated by the model. Such perifusion studies allow the quantitative assessment of insulin release kinetics under fully controllable experimental conditions of varying external concentrations of glucose, oxygen, or other compounds of interest, and can provide an informative assessment of islet quality and function. The time-profile of the insulin secretion calculated by the model was in good agree- ment with the experimental results obtained with isolated human islets. Detailed spatial distributions of glucose, oxygen, and insulin were calculated and are presented to provide a quantitative visualization of various important aspects of the insulin secretion dynamics in perifused islets.
基金Supported by National Natural Science Foundation of China, No. 30672094
文摘AIM: To determine whether the elevated vascular endothelial growth factor (VEGF) expression produced by the transfected vascular endothelial cells (VECs) could stimulate angiogenesis of the graft islets and exert its effect on the graft function. METHODS: Thirty diabetic recipient rats were divided into three groups (n = 10 per group). In the control group,300 IEQ islets were transplanted in each rat under the capsule of the right kidney,which were considered as marginal grafts. In the VEC group,VEC together with the islets were transplanted in each rat. In the VEGF group,VEC transfected by pIRES2-EGFP/ VEGF165 plasmid and the islets were transplanted in each rat. Blood glucose and insulin levels were evaluated every other day after operation. Intravenous glucose tolerance test (IVGTT) was performed 10 d after the transplantation. Hematoxylin and eosin (HE) staining was used to evaluate the histological features of the graft islets. Immunohistochemical staining was used to detect insulin-6,VEGF and CD34 (MVD) expression in the graft islets. RESULTS: Blood glucose and insulin levels in the VEGF group restored to normal 3 d after transplantation. In contrast,diabetic rats receiving the same islets with or without normal VECs displayed moderate hyperglycemia and insulin,without a significant difference between these two groups. IVGTT showed that both the amplitude of blood glucose induction and the kinetics of blood glucose in the VEGF group restored to normal after transplantation. H&E and immunohistochemical staining showed the presence of a large amount of graft islets under the capsule of the kidney,which were positively stained with insulin-6 and VEGF antibodies in the VEGF group. In the cell masses,CD34-stained VECs were observed. The similar masses were also seen in the other two groups,but with a fewer positive cells stained with insulin-6 and CD34 antibodies. No VEGF-positive cells appeared in these groups. Microvessel density (MVD) was significantly higher in the VEGF group compared to the other two groups. CONCLUSION: Elevated VEGF production by trans-fected vascular endothelial cells in the site of islet transplantation stimulates angiogenesis of the islet grafts. The accelerated islet revascularization in early stage could improve the outcome of islet transplantation,and enhance the graft survival.
文摘Objectives Langerhans' Cell histiocytosis (LCH) is a rare disease, which remains poorly understood and whose cellular origin remains unknown. To increase understanding of temporal bone LCH, it is necessary to study recent advances in the diagnosis and treatment of this disease. Methods The long term(5 to 30 years) results of 21 temporal bone LCH cases treated between 1973 and 2003 were reviewed. Surgery, radiotherapy, pharmacologic therapy or a combination of these treatments were employed in these cases. Results Eighteen patients were cured(18/21, 85%). Six patients developed residual diabetes insipidus (DI) and dwarfism (28%). Three patients died(14%). Conclusions The Alessi classification system for LCH based on the extent of disease accurately predicts prognosis and is a useful guide in selecting treatment methodologies. X-ray, computed tomography and magnetic resonance imaging have proved useful in defining the extent of osseous and soft tissue diseases. Diagnosis of LCH is based on clinical presentations, radiographic findings and histopathological results. Surgery and radiotherapy are the main treatment modalities. Pharmacologic therapy should be used in patients with aggressive, disseminate, and refractory lesions. LCH has a predilection for children and prognosis depends on age and extent of vital organ involvement.
文摘Langerhans cell histiocytosis (LCH) is a group of idiopathic disorders characterized by the proliferation of specialized,bone marrow-derived langerhans cells and mature eosinophils.The clinical spectrum ranges from an acute,fulminant,disseminated disease called LettererSiwe disease to solitary or few,indolent and chronic lesions of the bone or other organs called eosinophilic granuloma.Involvement of the gastrointestinal tract is very rare in LCH.We present the case of a 53-yearold woman referred by her primary care physician for a screening colonoscopy.A single sessile polyp,measuring 4 mm in size,was found in the rectum.Histopathological examination revealed that the lesion was relatively well circumscribed and comprised mainly a mixture of polygonal cells with moderate-to-abundant pink slightly granular cytoplasm.The nuclei within these cells had frequent grooves and were occasionally folded.Immunohistochemical staining was positive for CD1a which confirmed the diagnosis of LCH.On further workup,there was no evidence of involvement of any other organ.On follow up colonoscopy one year later,there was no evidence of disease recurrence.Review of the published literature revealed that LCH presenting as solitary colonic polyp is rare.However,with the increas-ing rates of screening colonoscopy,more colonic polyps may be identified as LCH on histopathology.This underscores the importance of recognizing this rare condition and ensuring proper follow-up to rule out systemic disease.
文摘Purpose:Ocular trauma occurs disproportionately in children on an annual basis.However,because of this frequency,other diagnoses,.such as orbital neoplasms,.can easily be ignored.Methods:We report on a two-year-old boy who presented with a dark purple,irregularly shaped lesion on his lower left eyelid.The patient had suffered injuries twice to that area.Results:Axial computed tomography images demonstrated an ill-defined and inhomogeneous soft tissue mass in the lateral and posterior region of the left orbit,.with bony destruction and absorption of the adjacent orbital wall..Magnetic resonance imaging of the orbit showed a lesion involving the greater sphenoidal wing,the supraorbital wall,and the frontal area.Enlarged nuchal and inguinal lymph nodes were detected by sonographic examination.Histopathological examination of a surgical biopsy showed an accumulation of characteristic Langerhans cells.The diagnosis of Langerhans cell histiocytosis was confirmed by immunohistochemical examinations positive for CD1a and SP-100.Conclusion:Orbital Langerhans cell histiocytosis is rarely encountered in ophthalmic practice,.so the ophthalmologist needs to be familiar with its presentation and work-up,.and has to be aware of possible OLCH diagnosis when a child(or even an adult)presents with prolonged and persistent eyelid edema,.even with a history of ocular trauma.
文摘Damped wave diffusion effects during oxygen transport in islets of Langerhans is studied. Simultaneous reaction and diffusion models were developed. The asymptotic limits of first and zeroth order in Michaelis and Menten kinetics was used in the study. Parabolic Fick diffusion and hyperbolic damped wave diffusion were studied separately. Method of relativistic transformation was used in order to obtain the solution for the hyperbolic model. Model solutions was used to obtain mass inertial times. Convective boundary condition was used. Sharma number (mass) may be used in evaluating the importance of the damped wave diffusion process in relation to other processes such as convection, Fick steady diffusion in the given application. Four regimes can be identified in the solution of hyperbolic damped wave diffusion model. These are;1) Zero Transfer Inertial Regime, 0 0≤τ≤τinertia;2) Rising Regime during times greater than inertial regime and less than at the wave front, Xp > τ, 3) at Wave front , τ = Xp;4) Falling Regime in open Interval, of times greater than at the wave front, τ > Xp. Method of superposition of steady state concentration and transient concentration used in both solutions of parabolic and hyperbolic models. Expression for steady state concentration developed. Closed form analytic model solutions developed in asymptotic limits of Michaelis and Menten kinetic at zeroth order and first order. Expression for Penetration Length Derived-Hypoxia Explained. Expression for Inertial Lag Time Derived. Solution was obtained by the method of separation of variables for transient for parabolic model and by the method of relativistic transformation for hyperbolic models. The concentration profile was expressed as a sum of steadty state and transient parts.
