H py/ori is probably the most prevalent human pathogen worldwide. Since it was initially suggested in 1983 by Marshall and Warren to be implicated in gastritis and peptic ulcer disease, H pylori has also been implicat...H py/ori is probably the most prevalent human pathogen worldwide. Since it was initially suggested in 1983 by Marshall and Warren to be implicated in gastritis and peptic ulcer disease, H pylori has also been implicated in gastric carcinoma and was classified as a class I carcinogen. In the last two decades, a noteworthy body of research has revealed the multiple processes that this gram negative bacterium activates to cause gastroduodenal disease in humans. Most infections are acquired early in life and may persist for the life of the individual. While infected individuals mount an inflammatory response that becomes chronic, along with a detectable adaptive immune response, these responses are ineffective in clearing the infection. Hpylori has unique features that allow it to reside within the harsh conditions of the gastric environment, and also to evade the host immune response. In this review, we discuss the various virulence factors expressed by this bacterium and how they interact with the host epithelium to influence pathogenesis.展开更多
A total of 39 Vibrio cholerae non O1 non O139 strains were isolated from surface waters of different parts of Dhaka City, Bangladesh. All these strains showed lack of ctx or zot gene, as demonstrated by the PCR analys...A total of 39 Vibrio cholerae non O1 non O139 strains were isolated from surface waters of different parts of Dhaka City, Bangladesh. All these strains showed lack of ctx or zot gene, as demonstrated by the PCR analysis. Eighteen representative strains were tested for enterotoxin production using a rabbit ileal loop model, of which live cells of 8 strains and culture filtrates of 6 strains produced fluid accumulation in ileal loops. However, none of them produced heat stable toxin （ST）, as detected by suckling mouse assay. On the other hand, 15% of isolates produced cytotoxin as detected by the Chinese Hamster Ovary （CHO） cell assay. Fifty times concentrated culture filtrates of the representative strains did not give any precipitin band against the anti-cholera toxin, suggesting the strains produced an enterotoxin, which is antigenically different from known cholera toxin （CT）. Eighty percent of the total isolates were found to be positive for heat labile haemolysin detected by tube method, whereas, 39% were found positive by the Christie-Atkins-Munch-Petersen （CAMP） method. However, 87% of the isolates were positive for haemagglutinin/protease and all of the strains were positive for mannose-sensitive-haemagglutinin assay.展开更多
Helicobacter pylori(H. pylori) is perhaps the most ubiquitous and successful human pathogen, since it colonizes the stomach of more than half of humankind. Infection with this bacterium is commonly acquired during chi...Helicobacter pylori(H. pylori) is perhaps the most ubiquitous and successful human pathogen, since it colonizes the stomach of more than half of humankind. Infection with this bacterium is commonly acquired during childhood. Once infected, people carry the bacteria for decades or even for life, if not treated. Persistent infection with this pathogen causes gastritis, peptic ulcer disease and is also strongly associated with the development of gastric cancer. Despite induction of innate and adaptive immune responses in the infected individual, the host is unable to clear the bacteria. One widely accepted hallmark of H. pylori is that it successfully and stealthily evades host defense mechanisms. Though the gastric mucosa is well protected against infection, H. pylori is able to reside under the mucus, attach to gastric epithelial cells and cause persistent infection by evading immune responses mediated by host. In this review, we discuss how H. pylori avoids innate and acquired immune response elements, uses gastric epithelial cells as mediators to manipulate host T cell responses and uses virulence factors to avoid adaptive immune responses by T cells to establish a persistent infection. We also discuss in this review how the genetic diversity of this pathogen helps for its survival.展开更多
AIM: To investigate age, sex, histopathology and Helicobacter pylori (H. pylori) status, as risk factors for gastroduodenal disease outcome in Brazilian dyspeptic patients.tients submitted to upper gastroscopy at Hosp...AIM: To investigate age, sex, histopathology and Helicobacter pylori (H. pylori) status, as risk factors for gastroduodenal disease outcome in Brazilian dyspeptic patients.tients submitted to upper gastroscopy at Hospital das Clinicas of Marilia, antral biopsy specimens were obtained and subjected to histopathology and H. pylori diagnosis. All patients presenting chronic gastritis (CG) and peptic ulcer (PU) disease localized in the stomach, gastric ulcer (GU) and/or duodenal ulcer (DU) were included in the study. Gastric biopsies (n = 668) positive for H. pylori by rapid urease test were investigated for vacuolating cytotoxin A (vacA ) medium (m) region mosaicism by polymerase chain reaction. Logistic regression analysis was performed to verify the association of age, sex, histopathologic alterations, H. pylori diagnosis and vacA m region mosaicism with the incidence of DU, GU and CG in patients. RESULTS: Of 1466 patients submitted to endoscopy, 1060 (72.3%) presented CG [male/female = 506/554; mean age (year) ± SD = 51.2 ± 17.81], 88 (6.0%) presented DU [male/female = 54/34; mean age (year) ± SD = 51.4 ± 17.14], and 75 (5.1%) presented GU [male/female = 54/21; mean age (year) ± SD = 51.3 ± 17.12] and were included in the comparative analysis. Sex and age showed no detectable effect on CG incidence (overall c 2 = 2.1, P = 0.3423). Sex [Odds ratios (OR) = 1.8631, P = 0.0058] but not age (OR = 0.9929, P = 0.2699) was associated with DU and both parameters had a highly significant effect on GU (overall c 2 = 30.5, P < 0.0001). The histopathological results showed a significant contribution of ageing for both atrophy (OR = 1.0297, P < 0.0001) and intestinal metaplasia (OR = 1.0520, P < 0.0001). Presence of H. pylori was significantly associated with decreasing age (OR = 0.9827, P < 0.0001) and with the incidence of DU (OR = 3.6077, P < 0.0001). The prevalence of m1 in DU was statistically significant (OR = 2.3563, P = 0.0018) but not in CG (OR = 2.678, P = 0.0863) and GU (OR = 1.520, P = 0.2863). CONCLUSION: In展开更多
Many active secretions produced by animals have been employed in the development of new drugs to treat diseases such as hypertension and cancer.Snake venom toxins coutributed significantly to the treatment of many med...Many active secretions produced by animals have been employed in the development of new drugs to treat diseases such as hypertension and cancer.Snake venom toxins coutributed significantly to the treatment of many medical conditions.There are many published studies describing and elucidating the anti-cancer potential of snake venom.Cancer therapy is one of the main areas for the use of protein peptides and enzymes originating from animals of different species.Some of these proteins or peptides and enzymes from snake venom when isolated and evaluated may bind specifically to cancer cell membranes,affecting the migration and proliferation of these cells.Some of substances found in the snake venom present a great potential as anti-tumor agent.In this review,we presented the main results of recent years of research involving the active compounds of snake venom that have anticancer activity.展开更多
BACKGROUND Approximately 90%of new cases of noncardiac gastric cancer(GC)are related to Helicobacter pylori(H.pylori),and cytotoxin-associated gene A(CagA)is one of the main pathogenic factors.Recent studies have show...BACKGROUND Approximately 90%of new cases of noncardiac gastric cancer(GC)are related to Helicobacter pylori(H.pylori),and cytotoxin-associated gene A(CagA)is one of the main pathogenic factors.Recent studies have shown that the pharmacological effects of cryptotanshinone(CTS)can be used to treat a variety of tumors.However,the effects of CTS on H.pylori,especially CagA+strain-induced gastric mucosal lesions,on the development of GC is unknown.AIM To assess the role of CTS in CagA-induced proliferation and metastasis of GC cells,and determine if CagA+H.pylori strains causes pathological changes in the gastric mucosa of mice.METHODS The effects of CTS on the proliferation of GC cells were assessed using the Cell Counting Kit-8(CCK-8)assay,and the abnormal growth,migration and invasion caused by CagA were detected by CCK-8 and transwell assays.After transfection with pSR-HA-CagA and treatment with CTS,proliferation and metastasis were evaluated by CCK-8 and transwell assays,respectively,and the expression of Src homology 2(SH2)domain–containing phosphatase 2(SHP2)and phosphorylated SHP2(p-SHP2)was detected using western blotting in AGS cells.The enzymelinked immunosorbent assay was used to determine the immunoglobulin G(IgG)level against CagA in patient serum.Mice were divided into four groups and administered H.pylori strains(CagA+or CagA-)and CTS(or PBS)intragastrically,and establishment of the chronic infection model was verified using polymerase chain reaction and sequencing of isolated strains.Hematoxylin and eosin staining was used to assess mucosal erosion in the stomach and toxicity to the liver and kidney.RESULTS CTS inhibited the growth of GC cells in dose-and time-dependent manners.Overexpression of CagA promoted the growth,migration,and invasion of GC cells.Importantly,we demonstrated that CTS significantly inhibited the CagAinduced abnormal proliferation,migration,and invasion of GC cells.Moreover,the expression of p-SHP2 protein in tumor tissue was related to the expression of IgG against CagA in the展开更多
基金the National Institutes of Health Grants DK50669and DK56338 EB was a recipient of a fellowship under NationaInstitutes of Health T32 AI007536-06 Training Grant. The costs ofpublication of this article were defrayed in part by the payment ofpage charges. The article must therefore be marked advertisemenin accordance with 18 U.S.C. section 1734 solely to indicate thisfact
文摘H py/ori is probably the most prevalent human pathogen worldwide. Since it was initially suggested in 1983 by Marshall and Warren to be implicated in gastritis and peptic ulcer disease, H pylori has also been implicated in gastric carcinoma and was classified as a class I carcinogen. In the last two decades, a noteworthy body of research has revealed the multiple processes that this gram negative bacterium activates to cause gastroduodenal disease in humans. Most infections are acquired early in life and may persist for the life of the individual. While infected individuals mount an inflammatory response that becomes chronic, along with a detectable adaptive immune response, these responses are ineffective in clearing the infection. Hpylori has unique features that allow it to reside within the harsh conditions of the gastric environment, and also to evade the host immune response. In this review, we discuss the various virulence factors expressed by this bacterium and how they interact with the host epithelium to influence pathogenesis.
文摘A total of 39 Vibrio cholerae non O1 non O139 strains were isolated from surface waters of different parts of Dhaka City, Bangladesh. All these strains showed lack of ctx or zot gene, as demonstrated by the PCR analysis. Eighteen representative strains were tested for enterotoxin production using a rabbit ileal loop model, of which live cells of 8 strains and culture filtrates of 6 strains produced fluid accumulation in ileal loops. However, none of them produced heat stable toxin （ST）, as detected by suckling mouse assay. On the other hand, 15% of isolates produced cytotoxin as detected by the Chinese Hamster Ovary （CHO） cell assay. Fifty times concentrated culture filtrates of the representative strains did not give any precipitin band against the anti-cholera toxin, suggesting the strains produced an enterotoxin, which is antigenically different from known cholera toxin （CT）. Eighty percent of the total isolates were found to be positive for heat labile haemolysin detected by tube method, whereas, 39% were found positive by the Christie-Atkins-Munch-Petersen （CAMP） method. However, 87% of the isolates were positive for haemagglutinin/protease and all of the strains were positive for mannose-sensitive-haemagglutinin assay.
基金Supported by National Institutes of Health grants K22AI68712,R56DK090090-01American Gastroenterological Association Research Scholar Award,NIH 1U54RR02614+3 种基金The University of Texas Medical Branch Clinical and Translational Sciences AwardThe American cancer society RSG-10-159-01-LIB,NIH 8UL1TR000041The University of New Mexico clinical and Translational Science CenterTaslima T Lina is funded by Sealy Centre for Vaccine Development Pre-doctoral fellowship and McLaughlin Pre-doctoral Fellowship,UTMB
文摘Helicobacter pylori(H. pylori) is perhaps the most ubiquitous and successful human pathogen, since it colonizes the stomach of more than half of humankind. Infection with this bacterium is commonly acquired during childhood. Once infected, people carry the bacteria for decades or even for life, if not treated. Persistent infection with this pathogen causes gastritis, peptic ulcer disease and is also strongly associated with the development of gastric cancer. Despite induction of innate and adaptive immune responses in the infected individual, the host is unable to clear the bacteria. One widely accepted hallmark of H. pylori is that it successfully and stealthily evades host defense mechanisms. Though the gastric mucosa is well protected against infection, H. pylori is able to reside under the mucus, attach to gastric epithelial cells and cause persistent infection by evading immune responses mediated by host. In this review, we discuss how H. pylori avoids innate and acquired immune response elements, uses gastric epithelial cells as mediators to manipulate host T cell responses and uses virulence factors to avoid adaptive immune responses by T cells to establish a persistent infection. We also discuss in this review how the genetic diversity of this pathogen helps for its survival.
基金Supported by Fundaao de Amparo a Pesquisa do Estado de So Paulo (FAPESP), Research Grant 06/01223-0Fellowship CGF 2001/14509-5
文摘AIM: To investigate age, sex, histopathology and Helicobacter pylori (H. pylori) status, as risk factors for gastroduodenal disease outcome in Brazilian dyspeptic patients.tients submitted to upper gastroscopy at Hospital das Clinicas of Marilia, antral biopsy specimens were obtained and subjected to histopathology and H. pylori diagnosis. All patients presenting chronic gastritis (CG) and peptic ulcer (PU) disease localized in the stomach, gastric ulcer (GU) and/or duodenal ulcer (DU) were included in the study. Gastric biopsies (n = 668) positive for H. pylori by rapid urease test were investigated for vacuolating cytotoxin A (vacA ) medium (m) region mosaicism by polymerase chain reaction. Logistic regression analysis was performed to verify the association of age, sex, histopathologic alterations, H. pylori diagnosis and vacA m region mosaicism with the incidence of DU, GU and CG in patients. RESULTS: Of 1466 patients submitted to endoscopy, 1060 (72.3%) presented CG [male/female = 506/554; mean age (year) ± SD = 51.2 ± 17.81], 88 (6.0%) presented DU [male/female = 54/34; mean age (year) ± SD = 51.4 ± 17.14], and 75 (5.1%) presented GU [male/female = 54/21; mean age (year) ± SD = 51.3 ± 17.12] and were included in the comparative analysis. Sex and age showed no detectable effect on CG incidence (overall c 2 = 2.1, P = 0.3423). Sex [Odds ratios (OR) = 1.8631, P = 0.0058] but not age (OR = 0.9929, P = 0.2699) was associated with DU and both parameters had a highly significant effect on GU (overall c 2 = 30.5, P < 0.0001). The histopathological results showed a significant contribution of ageing for both atrophy (OR = 1.0297, P < 0.0001) and intestinal metaplasia (OR = 1.0520, P < 0.0001). Presence of H. pylori was significantly associated with decreasing age (OR = 0.9827, P < 0.0001) and with the incidence of DU (OR = 3.6077, P < 0.0001). The prevalence of m1 in DU was statistically significant (OR = 2.3563, P = 0.0018) but not in CG (OR = 2.678, P = 0.0863) and GU (OR = 1.520, P = 0.2863). CONCLUSION: In
文摘Many active secretions produced by animals have been employed in the development of new drugs to treat diseases such as hypertension and cancer.Snake venom toxins coutributed significantly to the treatment of many medical conditions.There are many published studies describing and elucidating the anti-cancer potential of snake venom.Cancer therapy is one of the main areas for the use of protein peptides and enzymes originating from animals of different species.Some of these proteins or peptides and enzymes from snake venom when isolated and evaluated may bind specifically to cancer cell membranes,affecting the migration and proliferation of these cells.Some of substances found in the snake venom present a great potential as anti-tumor agent.In this review,we presented the main results of recent years of research involving the active compounds of snake venom that have anticancer activity.
基金National Natural Science Foundation of China,No.81572350。
文摘BACKGROUND Approximately 90%of new cases of noncardiac gastric cancer(GC)are related to Helicobacter pylori(H.pylori),and cytotoxin-associated gene A(CagA)is one of the main pathogenic factors.Recent studies have shown that the pharmacological effects of cryptotanshinone(CTS)can be used to treat a variety of tumors.However,the effects of CTS on H.pylori,especially CagA+strain-induced gastric mucosal lesions,on the development of GC is unknown.AIM To assess the role of CTS in CagA-induced proliferation and metastasis of GC cells,and determine if CagA+H.pylori strains causes pathological changes in the gastric mucosa of mice.METHODS The effects of CTS on the proliferation of GC cells were assessed using the Cell Counting Kit-8(CCK-8)assay,and the abnormal growth,migration and invasion caused by CagA were detected by CCK-8 and transwell assays.After transfection with pSR-HA-CagA and treatment with CTS,proliferation and metastasis were evaluated by CCK-8 and transwell assays,respectively,and the expression of Src homology 2(SH2)domain–containing phosphatase 2(SHP2)and phosphorylated SHP2(p-SHP2)was detected using western blotting in AGS cells.The enzymelinked immunosorbent assay was used to determine the immunoglobulin G(IgG)level against CagA in patient serum.Mice were divided into four groups and administered H.pylori strains(CagA+or CagA-)and CTS(or PBS)intragastrically,and establishment of the chronic infection model was verified using polymerase chain reaction and sequencing of isolated strains.Hematoxylin and eosin staining was used to assess mucosal erosion in the stomach and toxicity to the liver and kidney.RESULTS CTS inhibited the growth of GC cells in dose-and time-dependent manners.Overexpression of CagA promoted the growth,migration,and invasion of GC cells.Importantly,we demonstrated that CTS significantly inhibited the CagAinduced abnormal proliferation,migration,and invasion of GC cells.Moreover,the expression of p-SHP2 protein in tumor tissue was related to the expression of IgG against CagA in the
