A feeding trial was conducted to estimate the minimal dietary pantothenic acid (PA) requirement for juvenile grass shrimp, Penaeus monodon. Purified diets with seven levels (0, 20, 40, 60, 120, 240, and 480 mg/kg) of supplemental PA were fed to P. monodon (mean weight 0.88 +/- 0.01 g) for 8 wk. The level of PA detected in the unsupplemented diet was 0.02 mg/kg. Each diet was fed to three replicate groups of shrimp. Feed efficiencies (FE) and protein efficiency ratios were highest in shrimp fed the diets supplemented with 120, 240, and 480 mg PA/kg diet, followed by the groups fed 60 mg/kg, then 40 mg/kg, and finally the unsupplemented control group (P < 0.05). Shrimp fed diets supplemented with PA had significantly higher survival percentages and lower hepatopancreatic lipid concentration than those fed the unsupplemented, control diets. Broken-line regression analyses of weight gain percentage and hepatopancreatic CoA and PA concentrations of the shrimp indicated that the adequate dietary PA concentration in growing P. monodon is 101-139 mg/kg. (+info)
Catenary cultures of embryonic gastrointestinal tract support organ morphogenesis, motility, neural crest cell migration, and cell differentiation.
(10/2559)
The embryonic gastrointestinal tract develops from a simple tube into a coiled, flexed, and regionalized structure. The changes in gut morphology coincide with the differentiation of multiple cell types in concentric layers, and include colonization by migratory neuron precursors, and the development of gastrointestinal motility. We describe a reliable method for growing embryonic mouse intestine in vitro by the attachment of segments of intestinal tract by their cut ends, with the intervening region suspended in the culture medium. These are termed "catenary cultures." E11-E11.5 mouse midgut, hindgut, or mid- plus hindgut segments were grown in catenary culture for up to 10 days and their growth, morphology, cell differentiation, ability to support neural precursor migration, and contractile activity were assessed. The increase in size of the cultured explants was not large, but morphogenesis proceeded, best exemplified by elongation of the caecum. Cell differentiation also proceeded. In the mucosa, goblet cells differentiated. Muscle layers, characterized by desmin expression, and kit-positive interstitial cells of Cajal differentiated in the correct positions. Where segments initially included neural precursors in a small sub-region, these migrated and proliferated to form uniform neuronal networks throughout the entire explant, and the cells expressed the neuron markers nitric oxide synthase and neuron specific enolase. Gut motility was attained 5-6 days into the culture period, and both contractile- and mixing-type movements were observed. Thus, cell types representative of all three germ layer contributions developed, and in addition, the gut, being mainly free, was able to elongate and bend (unlike on solid support cultures), while retaining its rostrocaudal identity. (+info)
Natural and experimental oral infection of nonhuman primates by bovine spongiform encephalopathy agents.
(11/2559)
Experimental lemurs either were infected orally with the agent of bovine spongiform encephalopathy (BSE) or were maintained as uninfected control animals. Immunohistochemical examination for proteinase-resistant protein (prion protein or PrP) was performed on tissues from two infected but still asymptomatic lemurs, killed 5 months after infection, and from three uninfected control lemurs. Control tissues showed no staining, whereas PrP was detected in the infected animals in tonsil, gastrointestinal tract and associated lymphatic tissues, and spleen. In addition, PrP was detected in ventral and dorsal roots of the cervical spinal cord, and within the spinal cord PrP could be traced in nerve tracts as far as the cerebral cortex. Similar patterns of PrP immunoreactivity were seen in two symptomatic and 18 apparently healthy lemurs in three different French primate centers, all of which had been fed diets supplemented with a beef protein product manufactured by a British company that has since ceased to include beef in its veterinary nutritional products. This study of BSE-infected lemurs early in their incubation period extends previous pathogenesis studies of the distribution of infectivity and PrP in natural and experimental scrapie. The similarity of neuropathology and PrP immunostaining patterns in experimentally infected animals to those observed in both symptomatic and asymptomatic animals in primate centers suggests that BSE contamination of zoo animals may have been more widespread than is generally appreciated. (+info)
Gastrointestinal injuries during gynaecological laparoscopy.
(12/2559)
A retrospective case review study was carried out on gastrointestinal injuries which occur during gynaecological laparoscopy. Fifty-six patients with 62 gastrointestinal injuries were identified. One-third of the complications (32.2%) occurred during the installation phase for laparoscopy. Four of the six complications attributed to electrosurgery were secondary to the use of monopolar coagulation. Diagnosis of these gastrointestinal injuries was made during surgery in only 20 patients (35.7%). The mean time before diagnosis was 4.0 +/- 5.4 (range 0-23) days. Treatment of these complications was performed by laparoscopic surgery in 16.1% of cases. Prevention relies on the surgeon's experience, strict observance of the safety rules, perfect familiarity with the physical properties of the instruments used, systematic use of bowel preparation for patients presenting a risk of bowel complications, systematic supervision of the route taken by the trocars, meticulous inspection on completion of surgery of all areas where bowel adhesiolysis has been used and, in case of any doubt, tests for leakage involving the rectosigmoid. For patients with a risk of bowel complications, the creation of a pneumoperitoneum and performing a mini laparoscopy in the left hypochondrium can be the judicious option. (+info)
Library of sequence-specific radioimmunoassays for human chromogranin A.
(13/2559)
BACKGROUND: Human chromogranin A (CgA) is an acidic protein widely expressed in neuroendocrine tissue and tumors. The extensive tissue- and tumor-specific cleavages of CgA at basic cleavage sites produce multiple peptides. METHODS: We have developed a library of RIAs specific for different epitopes, including the NH2 and COOH termini and three sequences adjacent to dibasic sites in the remaining part of CgA. RESULTS: The antisera raised against CgA(210-222) and CgA(340-348) required a free NH2 terminus for binding. All antisera displayed high titers, high indexes of heterogeneity ( approximately 1.0), and high binding affinities (Keff0 approximately 0.1 x 10(12) to 1.0 x 10(12) L/mol), implying that the RIAs were monospecific and sensitive. The concentration of CgA in different tissues varied with the assay used. Hence, in a carcinoid tumor the concentration varied from 0.5 to 34.0 nmol/g tissue depending on the specificity of the CgA assay. The lowest concentration in all tumors was measured with the assay specific for the NH2 terminus of CgA. This is consistent with the relatively low concentrations measured in plasma from carcinoid tumor patients by the N-terminal assay, whereas the assays using antisera raised against CgA(210-222) and CgA(340-348) measured increased concentrations. CONCLUSION: Only some CgA assays appear useful for diagnosis of neuroendocrine tumors, but the entire library is valuable for studies of the expression and processing of human CgA. (+info)
Disinfection of upper gastrointestinal fibreoptic endoscopy equipment: an evaluation of a cetrimide chlorhexidine solution and glutaraldehyde.
(14/2559)
There is little information available on the bacteriological contamination of upper gastrointestinal fibreoptic endoscopes during routine use and the effects of 'disinfecting solutions'. A bacteriological evaluation was therefore made of cleaning an endoscope and its ancillary equipment with (1) water, (2) an aqueous solution of 1% cetrimide with 0.1% chlorhexidine, and (3) activated aqueous 2% glutaraldehyde. All equipment, but particularly the endoscope itself, was found to be heavily contaminated after use with a wide variety of organisms of which 53% were Gram positive. Cleaning the endoscope and ancillary equipment with water and the cetrimide/chlorhexidine solution alone or in combination was inadequate to produce disinfection but immersion in glutaraldehyde for two minutes consistently produced sterile cultures with our sampling technique. A rapid and simple method for disinfection of endoscopic equipment is therefore recommended and we think this is especially suitable for busy endoscopy units. (+info)
Distribution and metabolism of intravenously administered trefoil factor 2/porcine spasmolytic polypeptide in the rat.
(15/2559)
BACKGROUND: Trefoil peptides are secreted by mucus producing cells in the gastrointestinal tract and are supposed to be involved in oligomerisation processes of the mucin glycoproteins in the lumen. Endocrine functions have also been suggested. AIMS: To target possible binding sites for iodine-125 labelled porcine spasmolytic polypeptide (pSP) in an in vivo rat model. METHODS: 125I-pSP was given by intravenous injection to female Sprague-Dawley rats. The distribution of 125I-pSP was assessed by gamma counting of samples of organs and by autoradiography of paraffin wax embedded sections. The degradation of 125I-pSP was studied by trichloroacetic acid precipitation, and the saturability of binding by administration of excess unlabelled peptide. RESULTS: 125I-pSP was taken up in the kidneys and the gastrointestinal tract and was excreted almost unmetabolised in the urine. In the stomach, it could be displaced by unlabelled pSP in a dose dependent manner. Autoradiography showed grains in mucous neck cells, parietal cells, the mucus layer, and the pyloric glands of the stomach; in Brunner's glands and the Paneth cells in the small intestine; and in cells in the lower part of the crypts in the colon. CONCLUSIONS: 125I-pSP from the circulatory system is taken up by mucus producing cells in the gastrointestinal tract. The binding can be displaced by non-radioactive pSP, suggesting the presence of a receptor. (+info)
Curcumin inhibits cyclooxygenase-2 transcription in bile acid- and phorbol ester-treated human gastrointestinal epithelial cells.
(16/2559)
We investigated whether curcumin, a chemopreventive agent, inhibited chenodeoxycholate (CD)- or phorbol ester (PMA)-mediated induction of cyclooxygenase-2 (COX-2) in several gastrointestinal cell lines (SK-GT-4, SCC450, IEC-18 and HCA-7). Treatment with curcumin suppressed CD- and PMA-mediated induction of COX-2 protein and synthesis of prostaglandin E2. Curcumin also suppressed the induction of COX-2 mRNA by CD and PMA. Nuclear run-offs revealed increased rates of COX-2 transcription after treatment with CD or PMA and these effects were inhibited by curcumin. Treatment with CD or PMA increased binding of AP-1 to DNA. This effect was also blocked by curcumin. In addition to the above effects on gene expression, we found that curcumin directly inhibited the activity of COX-2. These data provide new insights into the anticancer properties of curcumin. (+info)