ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Bacterial enteric infections exact a heavy toll on human populations, particularly among children. Despite the explosion of knowledge on the pathogenesis of enteric diseases experienced during the past decade, the number of diarrheal episodes and human deaths reported worldwide remains of apocalyptic dimensions. However, our better understanding of the pathogenic mechanisms involved in the onset of diarrhea is finally leading to preventive interventions, such as the development of enteric vaccines, that may have a significant impact on the magnitude of this human plague.

ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Virus infections of the gastrointestinal tract, leading to gastroenteritis, are a common problem in both developed and developing countries. Rotavirus and Norwalk-like viruses are the most common agents responsible for clinically severe disease in humans, and this paper focuses on new information about the mechanisms of pathogenesis and epidemiology of these two pathogens. Rotavirus-induced disease involves a viral enterotoxin and activation of the enteric nervous system, as well as malabsorption, suggesting that common mechanisms of pathogenesis may exist between viral and bacterial pathogens. Each gastrointestinal virus possesses unique molecular properties that can be exploited to discover new information about responses of cells of the gastrointestinal tract. Work continues toward making vaccines for rotavirus and Norwalk-like viruses.

ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

The intestinal protozoa have gained importance to physicians practicing medicine in the United States, Canada, and Europe during recent years as a result of increasing world travel, the globalization of the world’s economy, and the growing number of chronically immunosuppressed people. During the spring of 1996,Cyclospora cayetanensiscaused diarrhea in approximately 1500 people exposed to Guatemalan raspberries. This epidemic recurred in 1997, emphasizing the risks of the global economy and food supply on which we depend. In addition to importation of intestinal protozoa from the tropics, AIDS and the increasing use of organ transplants have created a new population of people at risk for chronic infection by ubiquitous protozoa previously not known to cause serious human disease. These infections include cryptosporidiosis, isosporiasis, and microsporidiosis. Finally,Entamoeba histolytica, the etiologic agent of invasive amebiasis, has only recently been recognized to be a distinct species from a nonpathogenic but indistinguishable (by light microscopy) intestinal commensal,Entamoeba dispar. The rapidly changing epidemiology of these intestinal protozoa, as well as new approaches to diagnosis and treatment of these protozoa, are discussed.

ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Helicobacter pyloriinfects over half of the world population. Infection with the bacterium causes gastritis and peptic ulcer disease and is associated with the development of gastric cancers. However, only a small proportion of individuals develop these complications of infection. Therefore, identification of both host and bacterial factors that mediate disease is an intense area of current research interest. This review highlights recent advances in understanding of the mechanisms underlying disease pathophysiology following infection withH. pylori.

ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Helicobacter pyloricauses several gastroduodenal diseases. Various antibiotic regimens are available that eradicateH. pyloriin 80 to 90% of patients, but no regimen cures all patients. Dual therapy is now obsolete. Triple therapy with two antibiotics and either a proton pump inhibitor or bismuth is the regimens of choice. Metronidazole and clarithromycin are the two key antibiotics. Antibiotic resistance against these two drugs is becoming more problematic and should be taken into consideration when choosing a regimen. Antibiotic resistance is usually induced after failure. Quadruple therapy has been used as a salvage regimen in failed cases but it is also the most complicated regimen. Several new agents are being studied including a single capsule that contains bismuth, metronidazole, and tetracycline.

ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Gastrointestinal infections in children are a major cause of morbidity and mortality worldwide. Children living in developing countries are particularly susceptible to infectious diarrhea because of poor standards of hygiene and sanitation. Although the magnitude of diarrheal illnesses in developed countries is less, costly hospital admissions are still frequent. The causal agent of infectious diarrhea is most frequently related to age, geographical location, lifestyle habits, use of antibiotics, associated medical conditions, social circumstances, and degree of immune competence. In this article we present some of the most important articles published in the field during the last year. The role ofHelicobacter pyloriin the pathogenensis of gastritis and peptic ulcer disease has been shown in adults and children. Information about the natural history ofH. pylori, symptomatology, and diagnostic therapeutic approaches for children are being generated constantly; we discuss some of the most relevant information in this review.

ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

The gastrointestinal tract is a common site of infection in the opportunistic host. Pathogens range from highly virulent organisms, which infect people with well functioning immune systems as well as people with poorly functioning immune systems, to opportunistic organisms, which infect only those with impaired immune systems. Viruses, bacteria, fungi, and protozoa lead to disease that can be especially severe, debilitating, and difficult to treat in the immunocompromised host. Yet in this era of highly active antiretroviral therapy for HIV-infected patients and strategies to reduce immunosuppression in transplant and oncology patients, appropriate diagnostic tests and treatment can both improve the quality of life and decrease mortality. In this article, I review the changing pathogenesis, epidemiology, clinical presentation, diagnosis, and treatment of gastrointestinal infections in the immunocompromised host.

ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Studies aimed at improving treatment strategies for patients with acute diarrhea have included the clinical testing of modifications to the standard oral rehydration solution. A malabsorbed carbohydrate has been found to improve resuscitation, probably through the recruitment of colonic absorptive capacity. A reduced osmolarity solution is safe in adults and as effective as the standard solution. For nonnursing infants, increasing the frequency of feeding with reduced volume results in comparable total caloric intake and diminishes the risk of prolonged diarrhea. Increasing resistance of important enteric pathogens to inexpensive and newer antibiotics continues to be a concern. Reports from Asia of decreasedSalmonella typhiresistance to chloramphenicol, attributed to restricted antibiotic usage, may indicate a reversal of the usual trend. A strategy to block the action of shiga toxins in the gut through the use of recombinant bacteria has shown promise in a mouse model. A small but well-designed study supported the use of either norfloxacin or amoxicillin-clavulanic acid in the treatment of small bowel overgrowth syndrome. Studies exploring passive immunity strategies for the treatment ofEscherichia coli,Cryptosporidium,andCandidainfections have reported variable levels of success.

ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

Molecular-phylogenetic methods have revolutionized the analysis of complex microbial communities. Polymerase chain reaction amplification and phylogenetic analysis of small-subunit ribosomal RNA gene sequences allow microbes to be identified objectively, even in the absence of cultivation. Furthermore, the sequence information obtained by these means can be used to design sequence-based tools for identifying, tracking, and diagnosing the presence of microbes in complex samples. In this article, we summarize this approach and review its application to the study of the human gastrointestinal microbiota. Although just beginning, molecular-phylogenetic surveys of human gut microbes have revealed that most microbes identified in the gastrointestinal tract represent novel, previously undescribed species. A full description of the microbial constituents of the human gut will set the groundwork for interpreting how the gastrointestinal microbiota influence the health of the host.

ISSN:0267-1379    

出版商:OVID    

年代:2001

数据来源: OVID