Prostaglandin synthesis along the gastrointestinal tract of the rabbit: Differences in total synthesis and profile

In the present study we systematically investigated the synthesis of prostaglandins in the mucosa and the muscle layer along the length of the rabbit gut. Homogenates of mucosa and muscle layer were incubated with (14C)-labelled arachidonic acid, and prostaglandin formation was determined using thin-layer chromatography.With respect to total prostaglandin synthesis the highest values in the mucosa were measured in fundus, antrum and colon, whereas the prostaglandin synthesis in the muscle layer was maximal in the small bowel, particularly the ileum.In the mucosa, the prostaglandins E2 and F2a predominated, and there were minor differences along the gastrointestinal tract. In the muscle layer of the stomach, high amounts of 6-keto prostaglandin Fla, the stable degradation product of prostacyclin were produced, while small and large bowel homogenates synthesized mostly F2a. Consistently the prostaglandins A2/B2 were a major product in most locations. In addition, PG E2 catabolism to 15-keto PG E2 and 13,14-dihydro-15-keto PG E2 in the absence of NAD was slow.No significant changes in total prostaglandin synthesis and prostaglandin profile were detected between 24 hrs fasted and normally fed rabbits at any part of the gastrointestinal tract.     

Prostaglandin synthesis along the gastrointestinal tract of the rabbit: differences in total synthesis and profile

In the present study we systematically investigated the synthesis of prostaglandins in the mucosa and the muscle layer along the length of the rabbit gut. Homogenates of mucosa and muscle layer were incubated with (14C)-labelled arachidonic acid, and prostaglandin formation was determined using thin-layer chromatography. With respect to total prostaglandin synthesis the highest values in the mucosa were measured in fundus, antrum and colon, whereas the prostaglandin synthesis in the muscle layer was maximal in the small bowel, particularly the ileum. In the mucosa, the prostaglandins E2 and F2a predominated, and there were minor differences along the gastrointestinal tract. In the muscle layer of the stomach, high amounts of 6-keto prostaglandin F1a, the stable degradation product of prostacyclin were produced, while small and large bowel homogenates synthesized mostly F2a. Consistently the prostaglandins A2/B2 were a major product in most locations. In addition, PG E2 catabolism to 15-keto PG E2 and 13,14-dihydro-15-keto PG E2 in the absence of NAD was slow. No significant changes in total prostaglandin synthesis and prostaglandin profile were detected between 24 hrs fasted and normally fed rabbits at any part of the gastrointestinal tract.     

Binding to faeces and influence on human anaerobes of antimicrobial agents used for selective decontamination

The degree of binding of ampicillin, cephradine, co-trimoxazole, gentamicin, nalidixic acid, neomycin, polymyxin B and tobramycin by faecal substance as well as the influence of these antibiotics on human intestinal obligate anaerobes was investigated. In contrast to ampicillin, cephradine, co-trimoxazole and nalidixic acid, the nonabsorbable antibiotics polymyxin B and neomycin were bound to a considerable degree by human faeces. The binding of tobramycin and gentamicin to the solid part of faeces was less effective. The inhibitory effect of co-trimoxazole, gentamicin, nalidixic acid, neomycin, polymyxin B and tobramycin on the human obligate anaerobes was weak as compared with ampicillin and cephradine. Drugs which effectively eliminate Enterobacteriaceae from the gastrointestinal tract and which have a moderate effect on obligate anaerobes, like polymyxin B, are particularly suitable for selective decontamination of the gastrointestinal tract. The strong inactivating binding of aminoglycosides and polymyxin B to faeces accounts for the relatively high oral dose needed for a suitable faecal concentration.     

The efficiency of strict reverse isolation and antimicrobial decontamination in remission induction therapy of acute leukemia

The efficiency of strict reverse isolation and antimicrobial decontamination in remission induction therapy of acute leukemia was studied retrospectively in 47 patients who were treated with a standardized aggressive chemotherapy of daunorubicin and cytosine arabinoside. Twenty-two patients were treated in strict reverse isolation with antimicrobial decontamination and 25 patients in the open ward without any measures against infections. In the patients in isolation the incidence of new infections per patient was 0.77 compared to 1.42 in the control group. The rate of complete remissions was 77% in the patients in isolation vs. 56% in the control patients.     

Endotoxin and cytokines in patients with gastrointestinal tract perforation

Plasma levels of endotoxin and various cytokines were assessed in 70 patients with gastrointestinal tract perforation. Sepsis developed in 29 of them, and eight of these (27.6%) had on admission endotoxin levels higher than 9.8 pg ml(-1). The clinical outcome correlated with the level of tumour necrosis factor alpha (TNFalpha), rather than with the endotoxin level. The high interleukin 6 (IL-6) level was shown in septic patients and no correlation was observed between the IL-6 level and the clinical outcome. Plasma TNFalpha levels tended to change independently from endotoxin levels, suggesting that TNFalpha may have been locally produced in inflammatory lesions.     

Microecology of the gastrointestinal tract of chronic enteritis patients

The results obtained in the simultaneous study of the microbiology of different sections of the gastrointestinal tract (the oral cavity, the stomach, the large and small intestines) in chronic enteritis patients, as well as in the study of biopsy mucosa samples from the small intestine of such patients, are presented. This method has been shown to give a complete picture indicating both the severity of dysbiotic disturbances in the patient and the degree of their spread in the alimentary canal, which should be taken into account in clinical practice for the determination of the severity of the disease, the rational course of treatment and the time of the discharge of the patient from the hospital.     

Microflora of gastrointestinal tract in patients with chronic cholecystitis

AIM: Assessment of quantitative and qualitative characteristics of gastrointestinal microflora in patients with chronic cholecystitis. MATERIALS AND METHODS: Bacteriological analysis of biopsy samples of esophageal and gastric mucosae as well as stool samples was performed in 10 healthy volunteers and 28 patients with chronic cholecystitis. RESULTS: Opportunistic microorganisms are acquiring greater significance in formation of gastrointestinal microbiocenosis. Significant increase of both isolation rate and density of gastrointestinal tract colonization by staphylococci, enterobacteriae and anaerobic microorganisms was revealed. CONCLUSION: Obtained results showed abnormalities of microbiocenosis of esophageal and gastric mucosae and presence of intestinal disbacteriosis of different degrees of intensity.     

Selective decontamination of the intestine and total gnotobiologic isolation in treatment of mice with acute radiation sickness]

Comparative study of ciprofloxacin, pefloxacin and amikacin showed that ciprofloxacin and pefloxacin had a selective action on the intestinal microflora of conventional mice. Amikacin induced inhibition not only of the opportunistic bacteria but also of the representatives of the indigenous microflora. The use of the drugs in combination with total gnotobiological isolation in treatment of experimental radiation sickness provided an increase in survival of the irradiated animals, the more so as ciprofloxacin was used.     

慢性阻塞性肺病急性加重期下呼吸道病原菌感染及药敏结果分析

目的探讨慢性阻塞性肺病急性加重期(AECOPD)下呼吸道病原菌群的分布及分析药敏试验结果。方法对仙居县人民医院呼吸病房收治的128例AECOPD患者的痰细菌培养和药敏试验结果进行分析。结果 AECOPD患者感染的病原菌中,革兰阴性杆菌占61.95%,以铜绿假单胞菌、肺炎克雷伯菌、鲍曼不动杆菌为主;革兰阳性球菌占21.43%,以金黄色葡萄球菌、粪肠球菌为主;真菌占14.88%;2种以上病原菌混合感染占20.31%。体外药敏试验发现:亚胺培南对大部分革兰阴性杆菌有较好敏感性,万古霉素对大部分革兰阳性球菌有较好敏感性,检出的真菌对氟胞嘧啶、两性霉素、氟康唑、依曲康唑均保持较高敏感性。结论 AECOPD患者下呼吸道感染病原菌以革兰阴性杆菌为主,真菌感染率和混合感染率较高,应引起重视,应根据药敏结果合理选用抗菌药物。     

Evaluation of amixine reactivity and efficacy for prophylaxis of acute respiratory tract infections]

Amixine reactivity and tolerability were evaluated in controlled trial at the risk group of medical personal at the period of flu and respiratory viral infection season. Drugs safety was estimated according to anamnesis, direct observation and hemogram. High efficacy of the drug for the infections prophylaxis and treatment was demonstrated. The drug was well tolerated and had no side effects. Amixine unreactivity was proved.     

Mutualistic fermentative digestion in the gastrointestinal tract: diversity and evolution

All animals, including humans, are adapted to life in a microbialworld. Anaerobic habitats have existed continuously throughoutthe history of the earth, the gastrointestinal tract being acontemporary microniche. Since microorganisms colonize and growrapidly under the favorable conditions in the gut they couldcompete for nutrients with the host. This microbial challengehas modified the course of evolution in animals, resulting inselection of complex animal-microbe relationships that varytremendously, ranging from competition to cooperation. The ecologicaland evolutionary interactions between herbivorous dinosaursand the first mammalian herbivores and their food plants arereconstructed using knowledge gained during the study of modernliving vertebrates, especially foregut and hindgut fermentingmammals. The ruminant is well adapted to achieve maximal digestionof roughage using the physiological mechanism at the reticulo-omasalorifice which selectively retains large particles in the reticulo-rumen.However, the most obvious feature of all ruminants is the regurgitation,rechewing and reswallowing of foregut digesta termed rumination.Foregut fermenting mammals also share interesting and uniquefeatures in two enzymes, stomach lysozyme and pancreatic ribonucleasewhich accompany and are adaptations to this mode of digestion.The microbial community inhabiting the gastrointestinal tractis represented by all major groups of microbes (bacteria, archaea,ciliate protozoa, anaerobic fungi and bacteriophage) and characterizedby its high population density, wide diversity and complexityof interactions. The development and application of molecularecology techniques promises to link distribution and identityof gastrointestinal microbes in their natural environment withtheir genetic potential and in situ activities.