Interactions between BabA and Lewis b (Leb) related antigens are the best characterized adhesin-receptor interactions in Helicobacter pylori (H pylori). Several mechanisms for the regulation of BabA expression are pre...Interactions between BabA and Lewis b (Leb) related antigens are the best characterized adhesin-receptor interactions in Helicobacter pylori (H pylori). Several mechanisms for the regulation of BabA expression are predicted, including at both transcriptional and translational levels. The formation of chimeric proteins (babA /B or babB /A chimeras) seems to play an especially important role in translational regulation. Chimeric BabB/A protein had the potential to bind Leb; however, protein production was subject to phase variation through slipped strand mispairing. The babA gene was cloned initially from strain CCUG17875, which contains a silent babA1 gene and an expressed babA2 gene. The sequence of these two genes differs only by the presence of a 10 bp deletion in the signal peptide sequence of babA1 that eliminates its translational initiation codon. However, the babA1 type deletion was found only in strain CCUG17875. A few studies evaluated BabA status by immunoblot and confirmed that BabA-positive status in Western strains was closely associated with severe clinical outcomes. BabA-positive status also was associated with the presence of other virulence factors (e.g. cagA-positive status and vacA s1 genotype). A small class of strains produced low levels of the BabA protein and lacked Leb binding activity. These were more likely to be associated with increased mucosal inflammation and severe clinical outcomes than BabA-positive strains that exhibited Leb binding activity. The underlying mechanism is unclear, and further studies will be necessary to investigate how the complex BabA-receptor network is functionally coordinated during the interaction of H pylori with the gastric mucosa.展开更多
Some patients with ascites due to liver cirrhosis become no longer responsive to diuretics. Once other causes of ascites such as portal vein thrombosis, malignancy or infection and non-compliance with medications and ...Some patients with ascites due to liver cirrhosis become no longer responsive to diuretics. Once other causes of ascites such as portal vein thrombosis, malignancy or infection and non-compliance with medications and low sodium diet have been excluded, the diagnosis of refractory ascites can be made based on strict criteria. Patients with refractory ascites have very poor prognosis and therefore referral for consideration for liver transplantation should be initiated. Search for reversible components of the underlying liver pathology should be undertaken and targeted therapy, when available, should be considered. Currently, serial large volume paracentesis （LVP） and transjugular intrahepatic portasystemic stent-shunt （TIPS） are the two mainstay treatment options for refractory ascites. Other treatment options are available but not widely used either because they carry high morlJidity and mortality （most surgical options） rates, or are new interventions that have shown promise but still need further evaluation. In this comprehensive review, we describe the evaluation and management of patients with refractory ascites from the prospective of the practicing physician.展开更多
Colonization of stomach by H pylori is followed by a marked infiltration of the mucosa with polymorphonuclear leukocytes, macrophages, and lymphocytes that very often remains asymptomatic, but in some circumstances ca...Colonization of stomach by H pylori is followed by a marked infiltration of the mucosa with polymorphonuclear leukocytes, macrophages, and lymphocytes that very often remains asymptomatic, but in some circumstances can lead to the development of gastroduodenal ulceration, gastric carcinoma, and mucosa-associated lymphoid tissue lymphoma. The molecular mechanisms by which H pylori triggers and maintains the local immune response are complex, but there is evidence that cytokines produced by both immune and non-immune cells contribute to amplify the ongoing inflammation. H pylori infection is associated with a marked mucosal induction of T helper (Th) type 1 and Th17-type cytokines that is governed by specific antigen-presenting cell-derived molecules, such as interleukin (IL)-12 and IL-23. In this paper, we will review the available data on the expression and role of IL-23 and IL-17 in H pylori- related gastritis.展开更多
Hepatic portal venous gas (HPVG), an ominous radiologic sign, is associated in some cases with a severe underlying abdominal disease requiring urgent operative intervention. HPVG has been reported with increasing freq...Hepatic portal venous gas (HPVG), an ominous radiologic sign, is associated in some cases with a severe underlying abdominal disease requiring urgent operative intervention. HPVG has been reported with increasing frequency in medical literature and usually accompanies severe or lethal conditions. The diagnosis of HPVG is usually made by plain abdominal radiography, sonography, color Doppler flow imaging or computed tomography (CT) scan. Currently, the increased use of CT scan and ultrasound in the inpatient setting allows early and highly sensitive detection of such severe illnesses and also the recognition of an increasing number of benign and non-life threatening causes of HPVG. HPVG is not by itself a surgical indication and the treatment depends mainly on the underlying disease. The prognosis is related to the pathology itself and is not influenced by the presence of HPVG. Based on a review of the literature, we discuss in this paper the pathophysiology, risk factors, radiographic findings, management, and prognosis of pathologies associated with HPVG.展开更多
In addition to regulating acid secretion, the gastric antral hormone gastrin regulates several important cellular processes in the gastric epithelium including proliferation, apoptosis, migration, invasion, tissue rem...In addition to regulating acid secretion, the gastric antral hormone gastrin regulates several important cellular processes in the gastric epithelium including proliferation, apoptosis, migration, invasion, tissue remodelling and angiogenesis. Elevated serum concentrations of this hormone are caused by many conditions, particularly hypochlorhydria (as a result of autoimmune or Helicobacter pylori (H pylori)-induced chronic atrophic gastritis or acid suppressing drugs) and gastrin producing tumors (gastrinomas). There is now accumulating evidence that altered local and plasma concentrations of gastrin may play a role during the development of various gastric tumors. In the absence of H pylori infection, marked hypergastrinemia frequently results in the development of gastric enterochromaffi n cell-like neuroendocrine tumors and surgery to remove the cause of hypergastrinemia may lead to tumor resolution in this condition. In animal models such as transgenic INS-GAS mice, hypergastrinemia has also been shown to act as a cofactor with Helicobacter infection during gastric adenocarcinoma development. However, it is currently unclear as to what extent gastrin also modulates human gastric adenocarcinoma development. Therapeutic approaches targeting hypergastrinemia,such as immunization with G17DT, have been evaluated for the treatment of gastric adenocarcinoma, with some promising results. Although the mild hypergastrinemia associated with proton pump inhibitor drug use has been shown to cause ECL-cell hyperplasia and to increase H pylori-induced gastric atrophy, there is currently no convincing evidence that this class of agents contributes towards the development of gastric neuroendocrine tumors or gastric adenocarcinomas in human subjects.展开更多
AIM: To determine, by counting sister chromatid exchange (SCE) frequencies, whether genetic impairment and DNA damage have an effect on the pathogenesis of gastric cancer (GC). METHODS: Analysis of SCE is a cytogeneti...AIM: To determine, by counting sister chromatid exchange (SCE) frequencies, whether genetic impairment and DNA damage have an effect on the pathogenesis of gastric cancer (GC). METHODS: Analysis of SCE is a cytogenetic technique used to show DNA damage as a result of an exchange of DNA fragments between sister chromatids. We analyzed SCE frequency in 24 patients with GC, 26 patients with chronic atrophic gastritis (CAG), and 15 normal controls. The presence of H pylori was confirmed by urease test, toluidine-blue stain and hematoxylin-eosin stain. RESULTS: SCE was significantly increased in H pylori- negative GC patients, and in H pylori-negative CAG patients compared with controls (7.41 ± 1.36 and 6.92 ± 1.20, respectively, vs 5.54 ± 0.8, P < 0.001). There was no difference in the SCE frequency between H pylori- negative GC patients and H pylori-negative CAG patients (P > 0.05). On other hand, the SCE frequencies in H pylori-positive GC patients were higher than those in H pylori-positive CAG patients (9.20 ± 0.94 vs 7.93 ± 0.81, P < 0.01). Furthermore, H pylori-positive GC patients had a higher SCE frequency than H pylori- negative GC patients (9.20 ± 0.94 vs 7.41 ± 1.36, P < 0.001). Similarly, a significant difference was detected between H pylori-positive CAG patients and H pylori-negative CAG patients (7.93 ± 0.81 vs 6.92 ± 1.20, P < 0.05). CONCLUSION: We suggest the increased SCE in patients reflects a genomic instability that may be operative in gastric carcinogenesis.展开更多
An Outpatient Department is the first point of contact with the hospital, and good Doctor-Patient communication would improve the service quality of the hospital, so it is important to construct a harmonious Doctor-Pa...An Outpatient Department is the first point of contact with the hospital, and good Doctor-Patient communication would improve the service quality of the hospital, so it is important to construct a harmonious Doctor-Patient relationship. This article, from the perspective of psychology, investigates into the common psychological factors which affect the Doctor-Patient communication, the appearance of the communication problem, and make suggestions on possible solutions accordingly.展开更多
基金(in part) National Institutes of Health Grants, R01 DK62813
文摘Interactions between BabA and Lewis b (Leb) related antigens are the best characterized adhesin-receptor interactions in Helicobacter pylori (H pylori). Several mechanisms for the regulation of BabA expression are predicted, including at both transcriptional and translational levels. The formation of chimeric proteins (babA /B or babB /A chimeras) seems to play an especially important role in translational regulation. Chimeric BabB/A protein had the potential to bind Leb; however, protein production was subject to phase variation through slipped strand mispairing. The babA gene was cloned initially from strain CCUG17875, which contains a silent babA1 gene and an expressed babA2 gene. The sequence of these two genes differs only by the presence of a 10 bp deletion in the signal peptide sequence of babA1 that eliminates its translational initiation codon. However, the babA1 type deletion was found only in strain CCUG17875. A few studies evaluated BabA status by immunoblot and confirmed that BabA-positive status in Western strains was closely associated with severe clinical outcomes. BabA-positive status also was associated with the presence of other virulence factors (e.g. cagA-positive status and vacA s1 genotype). A small class of strains produced low levels of the BabA protein and lacked Leb binding activity. These were more likely to be associated with increased mucosal inflammation and severe clinical outcomes than BabA-positive strains that exhibited Leb binding activity. The underlying mechanism is unclear, and further studies will be necessary to investigate how the complex BabA-receptor network is functionally coordinated during the interaction of H pylori with the gastric mucosa.
文摘Some patients with ascites due to liver cirrhosis become no longer responsive to diuretics. Once other causes of ascites such as portal vein thrombosis, malignancy or infection and non-compliance with medications and low sodium diet have been excluded, the diagnosis of refractory ascites can be made based on strict criteria. Patients with refractory ascites have very poor prognosis and therefore referral for consideration for liver transplantation should be initiated. Search for reversible components of the underlying liver pathology should be undertaken and targeted therapy, when available, should be considered. Currently, serial large volume paracentesis （LVP） and transjugular intrahepatic portasystemic stent-shunt （TIPS） are the two mainstay treatment options for refractory ascites. Other treatment options are available but not widely used either because they carry high morlJidity and mortality （most surgical options） rates, or are new interventions that have shown promise but still need further evaluation. In this comprehensive review, we describe the evaluation and management of patients with refractory ascites from the prospective of the practicing physician.
文摘Colonization of stomach by H pylori is followed by a marked infiltration of the mucosa with polymorphonuclear leukocytes, macrophages, and lymphocytes that very often remains asymptomatic, but in some circumstances can lead to the development of gastroduodenal ulceration, gastric carcinoma, and mucosa-associated lymphoid tissue lymphoma. The molecular mechanisms by which H pylori triggers and maintains the local immune response are complex, but there is evidence that cytokines produced by both immune and non-immune cells contribute to amplify the ongoing inflammation. H pylori infection is associated with a marked mucosal induction of T helper (Th) type 1 and Th17-type cytokines that is governed by specific antigen-presenting cell-derived molecules, such as interleukin (IL)-12 and IL-23. In this paper, we will review the available data on the expression and role of IL-23 and IL-17 in H pylori- related gastritis.
文摘Hepatic portal venous gas (HPVG), an ominous radiologic sign, is associated in some cases with a severe underlying abdominal disease requiring urgent operative intervention. HPVG has been reported with increasing frequency in medical literature and usually accompanies severe or lethal conditions. The diagnosis of HPVG is usually made by plain abdominal radiography, sonography, color Doppler flow imaging or computed tomography (CT) scan. Currently, the increased use of CT scan and ultrasound in the inpatient setting allows early and highly sensitive detection of such severe illnesses and also the recognition of an increasing number of benign and non-life threatening causes of HPVG. HPVG is not by itself a surgical indication and the treatment depends mainly on the underlying disease. The prognosis is related to the pathology itself and is not influenced by the presence of HPVG. Based on a review of the literature, we discuss in this paper the pathophysiology, risk factors, radiographic findings, management, and prognosis of pathologies associated with HPVG.
基金Supported by Wellcome Trust Clinical Research Training Fellowship to MDB
文摘In addition to regulating acid secretion, the gastric antral hormone gastrin regulates several important cellular processes in the gastric epithelium including proliferation, apoptosis, migration, invasion, tissue remodelling and angiogenesis. Elevated serum concentrations of this hormone are caused by many conditions, particularly hypochlorhydria (as a result of autoimmune or Helicobacter pylori (H pylori)-induced chronic atrophic gastritis or acid suppressing drugs) and gastrin producing tumors (gastrinomas). There is now accumulating evidence that altered local and plasma concentrations of gastrin may play a role during the development of various gastric tumors. In the absence of H pylori infection, marked hypergastrinemia frequently results in the development of gastric enterochromaffi n cell-like neuroendocrine tumors and surgery to remove the cause of hypergastrinemia may lead to tumor resolution in this condition. In animal models such as transgenic INS-GAS mice, hypergastrinemia has also been shown to act as a cofactor with Helicobacter infection during gastric adenocarcinoma development. However, it is currently unclear as to what extent gastrin also modulates human gastric adenocarcinoma development. Therapeutic approaches targeting hypergastrinemia,such as immunization with G17DT, have been evaluated for the treatment of gastric adenocarcinoma, with some promising results. Although the mild hypergastrinemia associated with proton pump inhibitor drug use has been shown to cause ECL-cell hyperplasia and to increase H pylori-induced gastric atrophy, there is currently no convincing evidence that this class of agents contributes towards the development of gastric neuroendocrine tumors or gastric adenocarcinomas in human subjects.
文摘AIM: To determine, by counting sister chromatid exchange (SCE) frequencies, whether genetic impairment and DNA damage have an effect on the pathogenesis of gastric cancer (GC). METHODS: Analysis of SCE is a cytogenetic technique used to show DNA damage as a result of an exchange of DNA fragments between sister chromatids. We analyzed SCE frequency in 24 patients with GC, 26 patients with chronic atrophic gastritis (CAG), and 15 normal controls. The presence of H pylori was confirmed by urease test, toluidine-blue stain and hematoxylin-eosin stain. RESULTS: SCE was significantly increased in H pylori- negative GC patients, and in H pylori-negative CAG patients compared with controls (7.41 ± 1.36 and 6.92 ± 1.20, respectively, vs 5.54 ± 0.8, P < 0.001). There was no difference in the SCE frequency between H pylori- negative GC patients and H pylori-negative CAG patients (P > 0.05). On other hand, the SCE frequencies in H pylori-positive GC patients were higher than those in H pylori-positive CAG patients (9.20 ± 0.94 vs 7.93 ± 0.81, P < 0.01). Furthermore, H pylori-positive GC patients had a higher SCE frequency than H pylori- negative GC patients (9.20 ± 0.94 vs 7.41 ± 1.36, P < 0.001). Similarly, a significant difference was detected between H pylori-positive CAG patients and H pylori-negative CAG patients (7.93 ± 0.81 vs 6.92 ± 1.20, P < 0.05). CONCLUSION: We suggest the increased SCE in patients reflects a genomic instability that may be operative in gastric carcinogenesis.
文摘An Outpatient Department is the first point of contact with the hospital, and good Doctor-Patient communication would improve the service quality of the hospital, so it is important to construct a harmonious Doctor-Patient relationship. This article, from the perspective of psychology, investigates into the common psychological factors which affect the Doctor-Patient communication, the appearance of the communication problem, and make suggestions on possible solutions accordingly.
