Background: Cimetidine, an antagonist of histamine type II receptors, has shown protective effects against γ-rays or neutrons. However, there have been no reports on the effects of cimetidine against neutrons combine...Background: Cimetidine, an antagonist of histamine type II receptors, has shown protective effects against γ-rays or neutrons. However, there have been no reports on the effects of cimetidine against neutrons combined with γ-rays. This study was carried out to evaluate the protective effects of cimetidine on rats exposed to long-term, low-dose-rate neutron and γ-ray combined irradiation(n-γ LDR).Methods: Fifty male Sprague-Dawley(SD) rats were randomly divided into 5 groups: the normal control group, radiation model group, 20mg/(kg·d) cimetidine group, 80mg/(kg·d) cimetidine group and 160mg/(kg·d) cimetidine group(10 rats per group). Except for the normal control group, 40 rats were simultaneously exposed to fission neutrons(^(252)Cf, 0.085 m Gy/h) for 22 h every day and γ-rays(^(60)Co, 0.097Gy/h) for 1.03 h once every three days, and the cimetidine groups were administered intragastrically with cimetidine at doses of 20, 80 and 160mg/kg each day. Peripheral blood WBC of the rats was counted the day following exposure to γ-rays. The rats were anesthetized and sacrificed on the day following exposure to ^(252)Cf for 28 days. The spleen, thymus, testicle, liver and intestinal tract indexes were evaluated. The DNA content of bone marrow cells and concanavalin A(Con A)-induced lymphocyte proliferation were measured. The frequency of micronuclei in polychromatic erythrocytes(f MNPCEs), superoxide dismutase(SOD), malondialdehyde(MDA), and glutathione peroxidase(GSH-Px) in the serum and liver tissues were detected.Results: The peripheral blood WBC in the cimetidine groups was increased significantly on the 8th day and the 26 th day compared with those in the radiation model group. The spleen, thymus and testicle indexes of the cimetidine groups were higher than those of the radiation model group. The DNA content of bone marrow cells and lymphocyte proliferation in the cimetidine groups were increased significantly, and fMNPCE was reduced 1.41-1.77 fold in cimetidine treated groups. The activities of SOD and GSH-Px in the cimetidine groups were increased significantly, and the content of MDA in the cimetidine groups was decreased significantly.Conclusions: The results suggested that cimetidine alleviated damage induced by long-term, low-dose-rate neutron and γ combined irradiation via antioxidation and immunomodulation. Cimetidine might be useful as a potent radioprotector for radiotherapy patients as well as for occupational exposure workers.展开更多
The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus-2 has brought serious challenges for the medical field.Patients with COVID-19 usually have respiratory symptoms.Ho...The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus-2 has brought serious challenges for the medical field.Patients with COVID-19 usually have respiratory symptoms.However,liver dysfunction is not an uncommon presentation.Additionally,the degree of liver dysfunction is associated with the severity and prognosis of COVID-19.Prevention,diagnosis,and treatment of malnutrition should be routinely recommended in the management of patients with COVID-19,especially in those with liver dysfunction.Recently,a large number of studies have reported that nutrition therapy measures,including natural dietary supplements,vitamins,minerals and trace elements,and probiotics,might have potential hepatoprotective effects against COVID-19-related liver dysfunction via their antioxidant,antiviral,anti-inflammatory,and positive immunomodulatory effects.This review mainly focuses on the possible relationship between COVID-19 and liver dysfunction,nutritional and metabolic characteristics,nutritional status assessment,and nutrition therapy to provide a reference for the nutritionists while making evidence-based nutritional decisions during the COVID-19 pandemic.展开更多
Background: Wounded personnel who work at sea often encounter a plethora of difficulties. The most important of these difficulties is seawater immersion. Common medical dressings have little effect when the affected a...Background: Wounded personnel who work at sea often encounter a plethora of difficulties. The most important of these difficulties is seawater immersion. Common medical dressings have little effect when the affected area is immersed in seawater, and only rarely dressings have been reported for the treatment of seawater-immersed wounds. The objective of this study is to develop a new dressing which should be suitable to prevent the wound from seawater immersion and to promote the wound healing.Methods: Shark skin collagen(SSC) was purified via ethanol de-sugaring and de-pigmentation and adjusted for p H. A shark skin collagen sponge(SSCS) was prepared by freeze-drying. SSCS was attached to an anti-seawater immersion polyurethane(PU) film(SSCS+PU) to compose a new dressing. The biochemical properties of SSC and physicochemical properties of SSCS were assessed by standard methods. The effects of SSCS and SSCS+PU on the healing of seawaterimmersed wounds were studied using a seawater immersion rat model. For the detection of SSCS effects on seawaterimmersed wounds, 12 SD rats, with four wounds created in each rat, were divided into four groups: the 3 rd day group, 5 th day group, 7 th day group and 12 th day group. In each group, six wounds were treated with SSCS, three wounds treated with chitosan served as the positive control, and three wounds treated with gauze served as the negative control. For the detection of the SSCS+PU effects on seawater-immersed wounds, 36 SD rats were divided into three groups: the gauze(GZ)+PU group, chitosan(CS)+PU group and SSCS+PU group, with 12 rats in each group, and two wounds in each rat. The wound sizes were measured to calculate the healing rate, and histomorphology and the immunohistochemistry of the CD31 and TGF-β expression levels in the wounded tissues were measured by standard methods.Results: The results of Ultraviolet-visible(UV-vis) spectrum, Fourier-transform infrared(FTIR) spectrum, circular dichroism(CD) spectra, sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE), and amino acid composition analyses of SSC demonstrated that SSC is type I collagen. SSCS had a homogeneous porous structure of approximately 200μm, porosity rate of 83.57%±2.64%, water vapor transmission ratio(WVTR) of 4500 g/m2, tensile strength of 1.79±0.41 N/mm, and elongation at break of 4.52%±0.01%. SSCS had significant beneficial effects on seawater-immersed wound healing. On the 3 rd day, the healing rates in the GZ negative control, CS positive control and SSCS rats were 13.94%±5.50%, 29.40%±1.10% and 47.24%±8.40%, respectively. SSCS also enhanced TGF-in the initial stage of the healing period. The SSCS+PU dressing effectively protected woundsβ and CD31 expression from seawater immersion for at least 4 h, and accelerated re-epithelialization, vascularization and granulation formation of seawater-immersed wounds in the earlier stages of wound healing, and as well as significantly promoted wound healing. The SSCS+PU dressing also enhanced expression of TGF-n and gauze dressings.β and CD31. The effects of SSCS and SSCS+PU were superior to those of both the chitosaConclusion: SSCS has significant positive effects on the promotion of seawater-immersed wound healing, and a SSCS+PU dressing effectively prevents seawater immersion, and significantly promotes seawater-immersed wound healing.展开更多
The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)is spreading at an alarming rate,and it has created an unprecedented health emergency threatening ten...The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)is spreading at an alarming rate,and it has created an unprecedented health emergency threatening tens of millions of people worldwide.Previous studies have indicated that SARS-CoV-2 ribonucleic acid could be detected in the feces of patients even after smearnegative respiratory samples.However,demonstration of confirmed fecal-oral transmission has been difficult.Clinical studies have shown an incidence rate of gastrointestinal(GI)symptoms ranging from 2%to 79.1%in patients with COVID-19.They may precede or accompany respiratory symptoms.The most common GI symptoms included nausea,diarrhea,and abdominal pain.In addition,some patients also had liver injury,pancreatic damage,and even acute mesenteric ischemia/thrombosis.Although the incidence rates reported in different centers were quite different,the digestive system was the clinical component of the COVID-19 section.Studies have shown that angiotensinconverting enzyme 2,the receptor of SARS-CoV-2,was not only expressed in the lungs,but also in the upper esophagus,small intestine,liver,and colon.The possible mechanism of GI symptoms in COVID-19 patients may include direct viral invasion into target cells,dysregulation of angiotensin-converting enzyme 2,immune-mediated tissue injury,and gut dysbiosis caused by microbiota.Additionally,numerous experiences,guidelines,recommendations,and position statements were published or released by different organizations and societies worldwide to optimize the management practice of outpatients,inpatients,and endoscopy in the era of COVID-19.In this review,based on our previous work and relevant literature,we mainly discuss potential fecal-oral transmission,GI manifestations,abdominal imaging findings,relevant pathophysiological mechanisms,and infection control and prevention measures in the time of COVID-19.展开更多
基金supported by the Research Fund of National Science and Technology Major Project of China(No.2014ZX09J14103-07B)
文摘Background: Cimetidine, an antagonist of histamine type II receptors, has shown protective effects against γ-rays or neutrons. However, there have been no reports on the effects of cimetidine against neutrons combined with γ-rays. This study was carried out to evaluate the protective effects of cimetidine on rats exposed to long-term, low-dose-rate neutron and γ-ray combined irradiation(n-γ LDR).Methods: Fifty male Sprague-Dawley(SD) rats were randomly divided into 5 groups: the normal control group, radiation model group, 20mg/(kg·d) cimetidine group, 80mg/(kg·d) cimetidine group and 160mg/(kg·d) cimetidine group(10 rats per group). Except for the normal control group, 40 rats were simultaneously exposed to fission neutrons(^(252)Cf, 0.085 m Gy/h) for 22 h every day and γ-rays(^(60)Co, 0.097Gy/h) for 1.03 h once every three days, and the cimetidine groups were administered intragastrically with cimetidine at doses of 20, 80 and 160mg/kg each day. Peripheral blood WBC of the rats was counted the day following exposure to γ-rays. The rats were anesthetized and sacrificed on the day following exposure to ^(252)Cf for 28 days. The spleen, thymus, testicle, liver and intestinal tract indexes were evaluated. The DNA content of bone marrow cells and concanavalin A(Con A)-induced lymphocyte proliferation were measured. The frequency of micronuclei in polychromatic erythrocytes(f MNPCEs), superoxide dismutase(SOD), malondialdehyde(MDA), and glutathione peroxidase(GSH-Px) in the serum and liver tissues were detected.Results: The peripheral blood WBC in the cimetidine groups was increased significantly on the 8th day and the 26 th day compared with those in the radiation model group. The spleen, thymus and testicle indexes of the cimetidine groups were higher than those of the radiation model group. The DNA content of bone marrow cells and lymphocyte proliferation in the cimetidine groups were increased significantly, and fMNPCE was reduced 1.41-1.77 fold in cimetidine treated groups. The activities of SOD and GSH-Px in the cimetidine groups were increased significantly, and the content of MDA in the cimetidine groups was decreased significantly.Conclusions: The results suggested that cimetidine alleviated damage induced by long-term, low-dose-rate neutron and γ combined irradiation via antioxidation and immunomodulation. Cimetidine might be useful as a potent radioprotector for radiotherapy patients as well as for occupational exposure workers.
基金Supported by Major Construction Program of Military Key Disciplines during the 13^(th)Five-Year Plan Period,No.2020SZ21-15。
文摘The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus-2 has brought serious challenges for the medical field.Patients with COVID-19 usually have respiratory symptoms.However,liver dysfunction is not an uncommon presentation.Additionally,the degree of liver dysfunction is associated with the severity and prognosis of COVID-19.Prevention,diagnosis,and treatment of malnutrition should be routinely recommended in the management of patients with COVID-19,especially in those with liver dysfunction.Recently,a large number of studies have reported that nutrition therapy measures,including natural dietary supplements,vitamins,minerals and trace elements,and probiotics,might have potential hepatoprotective effects against COVID-19-related liver dysfunction via their antioxidant,antiviral,anti-inflammatory,and positive immunomodulatory effects.This review mainly focuses on the possible relationship between COVID-19 and liver dysfunction,nutritional and metabolic characteristics,nutritional status assessment,and nutrition therapy to provide a reference for the nutritionists while making evidence-based nutritional decisions during the COVID-19 pandemic.
基金supported by a Major Project of the Ministry of National Science and Technology of China(Grant No.2014ZX09J14103-09C).
文摘Background: Wounded personnel who work at sea often encounter a plethora of difficulties. The most important of these difficulties is seawater immersion. Common medical dressings have little effect when the affected area is immersed in seawater, and only rarely dressings have been reported for the treatment of seawater-immersed wounds. The objective of this study is to develop a new dressing which should be suitable to prevent the wound from seawater immersion and to promote the wound healing.Methods: Shark skin collagen(SSC) was purified via ethanol de-sugaring and de-pigmentation and adjusted for p H. A shark skin collagen sponge(SSCS) was prepared by freeze-drying. SSCS was attached to an anti-seawater immersion polyurethane(PU) film(SSCS+PU) to compose a new dressing. The biochemical properties of SSC and physicochemical properties of SSCS were assessed by standard methods. The effects of SSCS and SSCS+PU on the healing of seawaterimmersed wounds were studied using a seawater immersion rat model. For the detection of SSCS effects on seawaterimmersed wounds, 12 SD rats, with four wounds created in each rat, were divided into four groups: the 3 rd day group, 5 th day group, 7 th day group and 12 th day group. In each group, six wounds were treated with SSCS, three wounds treated with chitosan served as the positive control, and three wounds treated with gauze served as the negative control. For the detection of the SSCS+PU effects on seawater-immersed wounds, 36 SD rats were divided into three groups: the gauze(GZ)+PU group, chitosan(CS)+PU group and SSCS+PU group, with 12 rats in each group, and two wounds in each rat. The wound sizes were measured to calculate the healing rate, and histomorphology and the immunohistochemistry of the CD31 and TGF-β expression levels in the wounded tissues were measured by standard methods.Results: The results of Ultraviolet-visible(UV-vis) spectrum, Fourier-transform infrared(FTIR) spectrum, circular dichroism(CD) spectra, sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE), and amino acid composition analyses of SSC demonstrated that SSC is type I collagen. SSCS had a homogeneous porous structure of approximately 200μm, porosity rate of 83.57%±2.64%, water vapor transmission ratio(WVTR) of 4500 g/m2, tensile strength of 1.79±0.41 N/mm, and elongation at break of 4.52%±0.01%. SSCS had significant beneficial effects on seawater-immersed wound healing. On the 3 rd day, the healing rates in the GZ negative control, CS positive control and SSCS rats were 13.94%±5.50%, 29.40%±1.10% and 47.24%±8.40%, respectively. SSCS also enhanced TGF-in the initial stage of the healing period. The SSCS+PU dressing effectively protected woundsβ and CD31 expression from seawater immersion for at least 4 h, and accelerated re-epithelialization, vascularization and granulation formation of seawater-immersed wounds in the earlier stages of wound healing, and as well as significantly promoted wound healing. The SSCS+PU dressing also enhanced expression of TGF-n and gauze dressings.β and CD31. The effects of SSCS and SSCS+PU were superior to those of both the chitosaConclusion: SSCS has significant positive effects on the promotion of seawater-immersed wound healing, and a SSCS+PU dressing effectively prevents seawater immersion, and significantly promotes seawater-immersed wound healing.
文摘The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)is spreading at an alarming rate,and it has created an unprecedented health emergency threatening tens of millions of people worldwide.Previous studies have indicated that SARS-CoV-2 ribonucleic acid could be detected in the feces of patients even after smearnegative respiratory samples.However,demonstration of confirmed fecal-oral transmission has been difficult.Clinical studies have shown an incidence rate of gastrointestinal(GI)symptoms ranging from 2%to 79.1%in patients with COVID-19.They may precede or accompany respiratory symptoms.The most common GI symptoms included nausea,diarrhea,and abdominal pain.In addition,some patients also had liver injury,pancreatic damage,and even acute mesenteric ischemia/thrombosis.Although the incidence rates reported in different centers were quite different,the digestive system was the clinical component of the COVID-19 section.Studies have shown that angiotensinconverting enzyme 2,the receptor of SARS-CoV-2,was not only expressed in the lungs,but also in the upper esophagus,small intestine,liver,and colon.The possible mechanism of GI symptoms in COVID-19 patients may include direct viral invasion into target cells,dysregulation of angiotensin-converting enzyme 2,immune-mediated tissue injury,and gut dysbiosis caused by microbiota.Additionally,numerous experiences,guidelines,recommendations,and position statements were published or released by different organizations and societies worldwide to optimize the management practice of outpatients,inpatients,and endoscopy in the era of COVID-19.In this review,based on our previous work and relevant literature,we mainly discuss potential fecal-oral transmission,GI manifestations,abdominal imaging findings,relevant pathophysiological mechanisms,and infection control and prevention measures in the time of COVID-19.
