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Alimentary Tract (alimentary + tract)
Selected AbstractsEffects of Fungal Phytase on Utilization of Dietary Protein and Minerals, and Dephosphorylation of Phytic Acid in the Alimentary Tract of Channel Catfish Ictalurus punctatus Fed an All-Plant-Protein DietJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2002Weibing Yan A feeding trial was conducted to quantify the effects of phytase at levels of 0, 500, 1,000, 2,000, 4,000, and 8,000 units (U) per kg diet on utilization of dietary protein and minerals by fingerling (12 g) channel catfish Ictalurus punctatus fed an all-plant-protein diet composed of soybean meal, corn, and wheat middlings. The effects of phytase on dephosphorylation of phytic acid (phytate) in the alimentary tract of catfish also were determined. After 14 wk, mean weight gains (30.2,43.9 g/fish), feed conversion ratios (2.27,2.40 g feed consumed/g weight gain), protein efficiency ratios (1.47,1.61 g weight gaid/g protein consumed), and dietary protein retentions (23.8,26.7%) did not differ significantly (P > 0.05) among treatment groups. A digestibility trial conducted after the feeding trial showed no difference (P > 0.05) in mean digestibility of diet dry matter (49.0,58.3%) or crude protein (85.4-88.5%) among treatment groups. Concentrations of ash (46.7,48.6%), calcium (Ca, 17.9,18.5%), phosphorus (P, 9.1,9.5%), and manganese (Mn, 65.5,74.1 mg/kg) were significantly higher (P , 0.05) in bone of fish fed , 500 U/kg than in bone of fish fed 0 U/kg (ash, 43.5%; Ca, 16.4%; P, 8.4%; and Mn, 49.0 ma/kg), but concentrations of these minerals did not differ (P > 0.05) in bone of fish fed , 500 Uk/g. The magnesium (Mg) content of bone did not differ (P > 0.05) between fish fed 0 U/kg (0.29%) or 500 U/kg (0.34%), but was significantly lower in fish fed 0 U/kg than in fish fed , 1,000 U/kg (0.35,37%). Bone Mg levels did not differ (P > 0.05) among fish fed , 500 U/kg. The amount of zinc (Zn) in bone of fish fed 8,000 U/kg (153.3 mg/kg) was significantly higher than that in fish fed 0 U/kg (115.7 mg/kg) or 500 U/kg (130.3 mg/ kg), but did not differ from Zn levels in bone of fish fed 1,000,4,000 U/kg (134.5,135.8 mg/ kg). Dephosphorylation of phytate occurred primarily in the stomach within 2,8 h after diet ingestion, depending on the level of phytase supplementation. Initial levels of total phytate in the diet decreased 32,94% in stomach contents of fish fed l,000,8,000 U/kg within 2 h after feeding. Eight hours after feeding, stomach contents of fish fed , 1,000 U/kg contained less than 6% of initial total dietary phytate. Stomach contents of fish fed 500 U/kg retained 92% of initial total dietary phytate 2 h after feeding and 15% of total dietary phytate 8 h after feeding. Results of this study indicate that phytase supplementation at levels up to 8,000 U/kg diet did not increase weight gain or improve dietary protein utilization of channel catfish fed an all-plant-protein diet. Addition of phytase at a level of 1,000 U/kg diet was sufficient to significantly increase the Ca, P, Mg, and Mn content of bone, relative to fish fed an unsupplemented diet, and significantly decrease the quantity of total phytate in feces. A phytase level of 8,000 U/kg diet significantly increased the bioavailability of naturally occurring Zn in feed ingredients and increased the rate of phytate dephosphorylation in the stomach, compared with a diet containing no added phytase. Increased utilization of naturally occurring minerals in feed ingredients reduces the need for mineral supplements in diets and results in decreased elimination of minerals in feces. Thus, use of phytase in catfish feeds can be expected to provide both economic and environmental benefits. [source] Gross anatomy of the musculature and a new description of the reproductive system of Tanaisia bragai and Tanaisia inopina (Trematoda: Eucotylidae) analysed by confocal laser scanning microscopyACTA ZOOLOGICA, Issue 2 2010Sthefane D'ávila Abstract D'ávila, S., Manso, P. P. A., Bessa, E. C. A., Rodrigues, M. L. A. and Dias, R. J. P. 2010. Gross anatomy of the musculature and a new description of the reproductive system of Tanaisia bragai and Tanaisia inopina (Trematoda: Eucotylidae) analysed by confocal laser scanning microscopy. ,Acta Zoologica (Stockholm) 91: 139,149 Confocal scanning laser microscopy has become an important tool to clarify the organization of the musculature and innervation, as well as the morphology of the reproductive and alimentary tract of various helminth species. The goal of this work was to describe the morphology of the reproductive system and the gross anatomy of the musculature of adults of the species Tanaisia bragai and Tanaisia inopina by means of confocal scanning laser microscopy. The helminths were found parasitizing the kidney collection ducts of Columba livia, in the municipality of Juiz de Fora, Brazil. These helminths were stained with Mayer's carmalum, mounted on permanent slides and observed through a confocal scanning laser microscope. The tomographic images showed the morphology of the organs and glands of the reproductive system, along with the general morphology of the musculature of the body wall, oral sucker, acetabulum, pharynx, intestinal caeca, oesophagus and reproductive system ducts. The present work is the first re-characterization of the reproductive tract of T. bragai and T. inopina. We also present the first description of the general morphology of the gametes and cells of the glands associated with the reproductive apparatus of these species. [source] Mechanisms and modulation of intestinal epithelial repairINFLAMMATORY BOWEL DISEASES, Issue 1 2001Dr. Axel U. Dignass Abstract The mucosal epithelium of the alimentary tract represents a crucial barrier to a broad spectrum of noxious and immunogenic substances within the intestinal lumen. An impairment of the integrity of the mucosal epithelial barrier is observed in the course of various intestinal disorders including inflammatory bowel diseases (IBD), celiac disease, intestinal infections, and various other diseases. Furthermore, even under physiologic conditions temporary damage of the epithelial surface mucosa may be caused by proteases, residential flora, dietary compounds, or other factors. Generally, the integrity of the intestinal mucosal surface barrier is rapidly reestablished even after extensive destruction because of an enormous regenerative capability of the mucosal surface epithelium. Rapid resealing of the surface epithelium is accomplished by epithelial cell migration, also termed epithelial restitution, epithelial cell proliferation, and differentiation. Healing of the intestinal surface epithelium is regulated by a complex network of highly divergent factors, among them a broad spectrum of structurally distinct regulatory peptides that have been identified within the mucosa of the intestinal tract. These regulatory peptides, conventionally designated as growth factors and cytokines, play an essential role in regulating differential epithelial cell functions to preserve normal homeostasis and integrity of the intestinal mucosa. In addition, a number of other peptide molecules such as extracellular matrix factors and blood clotting factors, and also nonpeptide molecules including phospholipids, short-chain fatty acids, adenine nucleotides, trace elements, and pharmacological agents, have been demonstrated to modulate intestinal epithelial repair mechanisms. Some of these molecules may be released by platelets, adjacent stromal cells, inflammatory cells, or injured epithelial and nonepithelial cells and may play an important role in the modulation of intestinal injury. Repeated damage and injury of the intestinal surface are key features of various intestinal disorders including IBD and require constant repair of the epithelium. Enhancement of intestinal repair mechanisms by regulatory peptides or other modulatory factors may provide future approaches for the treatment of diseases that are characterized by injuries of the epithelial surface. [source] Metabolism of carbohydrate in alimentary tract of reindeer in winterINTEGRATIVE ZOOLOGY (ELECTRONIC), Issue 2 2006Tatyana I. KOCHAN Abstract The study was conducted on six reindeers in December. It was established that concentration of reducing sugars in the chyme of jejunum increases substantially (6 times in comparison with abomasum), whereas concentration cellulose, on the contrary, decreases (4.5 times). The maximal increase of monosaccharides in the small intestine testifies to formation of metabolic fund of sugars in this part of the alimentary tract due to high degree of polysaccharides hydrolysis of exogenous, as well as endogenous, microbial formation. Obtained data assume that the need of the reindeer for glucose is provided for not only by gluconeogenesis as it was considered before, but also by absorption of monosaccharides from the alimentary tract. [source] Eucalyptus pollen grain emptying by two Australian nectarivorous psittacinesJOURNAL OF AVIAN BIOLOGY, Issue 3 2001B. D. Gartrell The relative importance of pollen as a source of protein to vertebrates is controversial. In nectarivorous psittacine birds, field studies support its importance, but an experimental study in a nectarivorous parrot showed that less than 7% of pollen grains were emptied. We investigated pollen grain emptying by two nectarivorous Australian parrots, the Swift Parrot Lathamus discolor and the Musk Lorikeet Glossopsitta concinna. We used a controlled experiment, and examined pollen located at different levels through the alimentary tract of wild L. discolor. There was significant emptying of pollen grains (x=45.4%±1.91 s.e.) by all birds in the experimental trials. There was also a progressive increase in the percentage of pollen grains emptied at different sites along the alimentary tract in wild birds (crop x=24.2%±4.44 s.e., proventriculus x=34.0%±7.29 s.e., duodenum x=54.3%±5.42 s.e. and distal intestine x=64.2%±4.68 s.e.). The percentage of pollen grains emptied by captive L. discolor in the experimental trial (x=44.1%±2.77 s.e.) was not significantly different from that found in wild L. discolor (x=40.3%±4.25 s.e.). Both species of nectarivorous parrot were able to rapidly ingest large quantities of Eucalyptus pollen and appeared to empty the pollen grains efficiently. Eucalyptus pollen appears to be an important source of protein for these birds. [source] The ontogeny of the alimentary tract of larval pandora, Pagellus erythrinus L.JOURNAL OF FISH BIOLOGY, Issue 2004V. Micale The ontogenesis of the alimentary tract and its associated structures (liver, pancreas, gall bladder) was studied in common pandora Pagellus eythrinus L., a promising species for diversification in Mediterranean aquaculture. Mass production of pandora has been limited so far by high larval and juvenile mortalities, which appear to be related to nutritional deficiencies. The development of the larval digestive system was studied histologically from hatching (0 DAH) until day 50 (50 DAH) in reared specimens, obtained by natural spawning from a broodstock adapted to captivity. At first feeding (3,4 DAH) both the mouth and anus had opened and the digestive tract was differentiated in four portions: buccopharynx, oesophagus, incipient stomach and intestine. The pancreas, liver and gall bladder were also differentiated at this stage. Soon after the commencement of exogenous feeding (5,6 DAH), the anterior intestinal epithelium showed large vacuoles indicating the capacity for absorption of lipids, whereas acidophilic supranuclear inclusions indicating protein absorption were observed in the posterior intestinal epithelium. Both the bile and main pancreatic ducts had opened in the anterior intestine, just after the pyloric sphincter, at this stage. Intestinal coiling was apparent since 4 DAH, while mucosal folding began at 10 DAH. Scattered mucous cells occurred in the oral cavity and the intestine, while they were largely diffused in the oesophagus. Gastric glands and pyloric caeca were firstly observed at 28 DAH and appeared well developed by 41 DAH, indicating the transition from larval to juvenile stage and the acquisition of an adult mode of digestion. [source] CLINICAL COURSE and RELAPSE RATE IN INTESTINAL BEHCET'S DISEASEJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 2001TI Kim Behçet's disease is a multisystemic recurrent inflammatory disease. Gastrointestinal tract involvement in Behçet's disease has been identified throughout the alimentary tract and causes diverse symptoms. Various treatment have been utilized to induce or maintain remission. However, little is known about clinical course and prognosis in Behçet's disease with intestinal involvement. The aims of this study were to evaluate the clinical course and relapse rate in intestinal Behçet's disease and to investigate factors that may affect relapse. Methods, Clinical course and characteristics, including demographic parameters, gastrointestinal symptoms as well as systemic manifestations, laboratory data, endoscopic findings, and treatment strategies for the induction of remission, of 97 patients (49 male, 48 female) with intestinal Behçet's disease were retrospectively reviewed. Cumulative relapse free rate and factors related with relapse were analysed by Kaplan,Meier method and log,rank test, respectively. Results, The median duration of the relapse free period was 7 months (ranges from 1 to 171 months). One, two, and five year relapse free rates were 41.2, 29.7 and 10.2%, respectively. Sex, clinical subtype of Behçet's disease, symptom and laboratory data at onset, colonoscopic findings, such as distribution of lesions as well as number, size, depth, and shape of ulcer, and initial treatment (medical vs. surgical) did not affect relapse rate. However, large ulcers (> 20 mm) and young age at onset (< 37 years old) were factors significantly related with higher relapse rate (P < 0.05, log,rank test). Conclusion, High relapse rate in intestinal Behçet's disease was identified. Age at onset and size of the ulcer are factors related with long-term prognosis of intestinal Behçet's disease. [source] Spontaneous neoplasia in the baboon (Papio spp.)JOURNAL OF MEDICAL PRIMATOLOGY, Issue 2 2007Rachel E. Cianciolo Abstract Background, There are several comprehensive reviews of spontaneous neoplasia in non-human primates that compile individual cases or small numbers of cases, but do not provide statistical analysis of tumor incidence, demographics, or epidemiology. Methods, This paper reports all spontaneous neoplasms (n = 363) diagnosed over a 15-year period in a baboon colony with an average annual colony population of 4000. Results, A total of 363 spontaneous neoplasms were diagnosed in 313 baboons: 77 cases were males (25%) and 236 were females (75%); ages ranged from 1 month to 33 years (mean 16.5, median 17). Conclusions, The organ systems affected in descending order of number of neoplasms were hematopoietic organs (n = 101, 28%), urogenital tract (n = 78, 21%), integument (n = 43, 12%), alimentary tract (n = 43, 12%), endocrine organs (n = 40, 11%), nervous system (n = 33, 9%), musculoskeletal system (n = 5, 1%), and respiratory system (n = 4, 1%). Malignant cases numbered 171 (47%); 192 (53%) cases were benign. [source] Gastrointestinal foreign bodies in dogs and cats: a retrospective study of 208 casesJOURNAL OF SMALL ANIMAL PRACTICE, Issue 11 2009G. Hayes Objectives:To establish predilection sites of obstruction and to investigate clinical factors associated with a poor outcome. Methods:A retrospective study of 208 consecutive cases over a 48-month period from first-opinion practice. Results:Overall, 91 per cent of cases recovered with higher survival rates from discrete foreign bodies (94 per cent in dogs and 100 per cent in cats) as opposed to linear foreign bodies (80 per cent in dogs and 63 per cent in cats). English bull terriers, springer spaniels, Staffordshire bull terriers, Border collies and Jack Russell terriers were over-represented. In dogs, 63 per cent of obstructions occurred in the jejunum but foreign objects were encountered at all points along the gastrointestinal tract. A longer duration of clinical signs, the presence of a linear foreign body and multiple intestinal procedures were associated with significantly increased mortality. Neither the degree of obstruction (partial or complete) nor the location of the foreign body was shown to have a significant influence on survival. Clinical Significance:Prompt presentation, diagnosis and surgical intervention improve the outcome of gastrointestinal obstruction by foreign bodies. At surgery, the minimal number of intestinal procedures should be performed to restore the integrity of the alimentary tract. [source] Relationship between faecal character and intestinal transit time in normal dogs and diet-sensitive dogsJOURNAL OF SMALL ANIMAL PRACTICE, Issue 7 2002V. E. Rolfe The relationship between stool character and whole gut transit time (WGTT), which is the average time for the passage of material through the lumen of the alimentary tract from ingestion to defecation, was studied in eight control dogs and 12 dogs with nonspecific dietary sensitivity. Dogs were fed four diets in a cross-over design, and faecal quality was assessed daily and WGTT determined using plastic pellets. Faecal quality was unaffected by diet in the control dogs. Dogs with dietary sensitivity produced looser faeces compared with the control dogs, and this was significant for two of the diets. There was no significant effect of diet on mean WGTT within or between groups. Minimum WGTT, which was the interval to the first appearance of markers in faeces, was shorter in sensitive dogs compared with controls, and this was significant for two of the four diets. There were significant, inverse relationships between minimum WGTT and both mean faeces score and percentage unacceptable defecations. These data suggest that rapid transit of certain dietary components may impact negatively on stool quality and contribute to loose faeces in dogs with non-specific dietary sensitivity. [source] Effects of Fungal Phytase on Utilization of Dietary Protein and Minerals, and Dephosphorylation of Phytic Acid in the Alimentary Tract of Channel Catfish Ictalurus punctatus Fed an All-Plant-Protein DietJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 1 2002Weibing Yan A feeding trial was conducted to quantify the effects of phytase at levels of 0, 500, 1,000, 2,000, 4,000, and 8,000 units (U) per kg diet on utilization of dietary protein and minerals by fingerling (12 g) channel catfish Ictalurus punctatus fed an all-plant-protein diet composed of soybean meal, corn, and wheat middlings. The effects of phytase on dephosphorylation of phytic acid (phytate) in the alimentary tract of catfish also were determined. After 14 wk, mean weight gains (30.2,43.9 g/fish), feed conversion ratios (2.27,2.40 g feed consumed/g weight gain), protein efficiency ratios (1.47,1.61 g weight gaid/g protein consumed), and dietary protein retentions (23.8,26.7%) did not differ significantly (P > 0.05) among treatment groups. A digestibility trial conducted after the feeding trial showed no difference (P > 0.05) in mean digestibility of diet dry matter (49.0,58.3%) or crude protein (85.4-88.5%) among treatment groups. Concentrations of ash (46.7,48.6%), calcium (Ca, 17.9,18.5%), phosphorus (P, 9.1,9.5%), and manganese (Mn, 65.5,74.1 mg/kg) were significantly higher (P , 0.05) in bone of fish fed , 500 U/kg than in bone of fish fed 0 U/kg (ash, 43.5%; Ca, 16.4%; P, 8.4%; and Mn, 49.0 ma/kg), but concentrations of these minerals did not differ (P > 0.05) in bone of fish fed , 500 Uk/g. The magnesium (Mg) content of bone did not differ (P > 0.05) between fish fed 0 U/kg (0.29%) or 500 U/kg (0.34%), but was significantly lower in fish fed 0 U/kg than in fish fed , 1,000 U/kg (0.35,37%). Bone Mg levels did not differ (P > 0.05) among fish fed , 500 U/kg. The amount of zinc (Zn) in bone of fish fed 8,000 U/kg (153.3 mg/kg) was significantly higher than that in fish fed 0 U/kg (115.7 mg/kg) or 500 U/kg (130.3 mg/ kg), but did not differ from Zn levels in bone of fish fed 1,000,4,000 U/kg (134.5,135.8 mg/ kg). Dephosphorylation of phytate occurred primarily in the stomach within 2,8 h after diet ingestion, depending on the level of phytase supplementation. Initial levels of total phytate in the diet decreased 32,94% in stomach contents of fish fed l,000,8,000 U/kg within 2 h after feeding. Eight hours after feeding, stomach contents of fish fed , 1,000 U/kg contained less than 6% of initial total dietary phytate. Stomach contents of fish fed 500 U/kg retained 92% of initial total dietary phytate 2 h after feeding and 15% of total dietary phytate 8 h after feeding. Results of this study indicate that phytase supplementation at levels up to 8,000 U/kg diet did not increase weight gain or improve dietary protein utilization of channel catfish fed an all-plant-protein diet. Addition of phytase at a level of 1,000 U/kg diet was sufficient to significantly increase the Ca, P, Mg, and Mn content of bone, relative to fish fed an unsupplemented diet, and significantly decrease the quantity of total phytate in feces. A phytase level of 8,000 U/kg diet significantly increased the bioavailability of naturally occurring Zn in feed ingredients and increased the rate of phytate dephosphorylation in the stomach, compared with a diet containing no added phytase. Increased utilization of naturally occurring minerals in feed ingredients reduces the need for mineral supplements in diets and results in decreased elimination of minerals in feces. Thus, use of phytase in catfish feeds can be expected to provide both economic and environmental benefits. [source] Chronic Intestinal Inflammation and Intestinal Disease in DogsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2003A.J. German Normal individuals maintain tolerance to the endogenous bacterial flora residing within their alimentary tract, a phenomenon mediated by the gastrointestinal lymphoid tissue. Loss of this tolerance is a key factor in the development of chronic intestinal inflammation. Manifestations of such uncontrolled inflammation in humans include inflammatory bowel disease and celiac disease. Dogs may similarly be affected, and although the etiopathogenesis is likely similar, the lesions differ. This review includes discussion of the factors involved in breakdown of mucosal tolerance, the immunologic basis of canine enteropathies, and the use of novel immunotherapies for these diseases. [source] Drug information for patients,an update of long-term results: type of enquiries and patient characteristics,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 2 2009Martin Huber MPharm Abstract Purpose To analyse the type of enquiries to a drug information service in Germany, available exclusively for patients. Methods Sociodemographic characteristics of the patients who used the service, number and kind of drugs taken, existing diseases, reasons for enquiry as well as type of answers provided were recorded. For the present evaluation we analysed all enquiries to the service from August 2001 to January 2007. Results A total of 5587 enquiries were received. 5013 enquiries from 4091 patients were available for further analysis in detail. The patient group using the service most frequently were women between 61 and 70 years (23.3%). 1457 enquiries (29.1%) were made by patients who had contacted the information service once or several times before. The group of drugs most often asked about were cardiovascular drugs (33.4%), followed by drugs for the nervous system (16.2%) and for the alimentary tract and metabolism (12.4%). On average, each patient had questions about 2.6 (median 1; 1,22) drugs simultaneously. Common reasons for contacting the service were adverse drug reactions (22.1%), the need for general information about the drug (19.9%), information about therapy (12.4%) and drug interactions (10.2%). Conclusions A lot of patients need additional information about their medication, especially concerning drug groups that are frequently prescribed. The presented drug information service can be one helpful tool to counteract these information deficits and to increase patients' knowledge about their drugs. Copyright © 2008 John Wiley & Sons, Ltd. [source] Development of testis and digestive tract in longnose gar (Lepisosteus osseus) at the onset of exogenous feeding of larvae and in juvenilesAQUACULTURE RESEARCH, Issue 10 2010Marta Jaroszewska Abstract The aim of this study was to describe the ontogenetic development of the testis and the alimentary tract in longnose gar (Lepisosteus osseus) related to fish size and age at the onset of exogenous feeding and late ontogenesis. Using light microscopy, testes were first detected histologically by the appearance of primordial germ cells 9 days after the first exogenous feeding [31,31.5 mm total body length(TL)] and presumptive seminiferous tubules (maleness characteristic) in fish of 107 mm TL. The present histological studies indicated that the alimentary tract of lepisosteids is completely functional at the beginning of exogenous feeding, several days before the completion of yolk absorption. Based on these results, we have concluded that garfish larvae/juveniles can be effectively trained to consume formulated diets at early stages, after an initial feeding of live food for 2,3 days (23.5 mm TL). Our findings provide evidence of the first controlled rearing of longnose gar using live and formulated diets, providing the possibility of experimental work with this non-teleost fish. [source] Cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the N-terminal carbohydrate-recognition domain of human galectin-4ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2010Ana Lucia L. R. Zimbardi Galectin-4 is a tandem-repeat-type galectin that is expressed in the epithelium of the alimentary tract from the tongue to the large intestine. Additionally, strong expression of galectin-4 can also be induced in cancers in other tissues, including the breast and liver. In order to explore its potential as a target for anticancer drug design, elucidation of the structural basis of the carbohydrate-binding specificities of galectin-4 has been focused on. As an initial step, the N-terminal carbohydrate-recognition domain of human galectin-4 (hGal4-CRD-1) has been successfully crystallized using the vapour-diffusion technique, a complete data set has been collected to 2.2,Å resolution and the structure has been solved by the molecular-replacement technique. The crystals belonged to space group P6122, with unit-cell parameters a = b = 71.25, c = 108.66,Å. The asymmetric unit contained one molecule of hGal4-CRD-1, with a VM value of 2.34,Å3,Da,1 and a solvent content of 47.51%. [source] Crystallization and preliminary X-ray diffraction analysis of mouse galectin-4 N-terminal carbohydrate recognition domain in complex with lactoseACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 7 2008Veronika Krej, íková Galectin-4 is thought to play a role in the process of tumour conversion of cells of the alimentary tract and the breast tissue; however, its exact function remains unknown. With the aim of elucidating the structural basis of mouse galectin-4 (mGal-4) binding specificity, we have undertaken X-ray analysis of the N-terminal domain, CRD1, of mGal-4 in complex with lactose (the basic building block of known galectin-4 carbohydrate ligands). Crystals of CRD1 in complex with lactose were obtained using vapour-diffusion techniques. The crystals belong to tetragonal space group P4212 with unit-cell parameters a = 91.1, b = 91.16, c = 57.10,Å and preliminary X-ray diffraction data were collected to 3.2,Å resolution. An optimized crystallization procedure and cryocooling protocol allowed us to extend resolution to 2.1,Å. Structure refinement is currently under way; the initial electron-density maps clearly show non-protein electron density in the vicinity of the carbohydrate binding site, indicating the presence of one lactose molecule. The structure will help to improve understanding of the binding specificity and function of the potential colon cancer marker galectin-4. [source] Attaching and effacing pathogen-induced tight junction disruption in vivoCELLULAR MICROBIOLOGY, Issue 4 2006Julian A. Guttman Summary Diarrhoea is a hallmark of infections by the human attaching and effacing (A/E) pathogens, enterohaemorrhagic Escherichia coli (EHEC) and enteropathogenic E. coli (EPEC). Although the mechanisms underlying diarrhoea induced by these pathogens remain unknown, cell culture results have suggested that these pathogens may target tight junctions. Tight junctions in the colon function as physical intercellular barriers that separate and prevent mixing of the luminal contents with adlumenal regions of the epithelium. Consequently, it is thought that the disruption of intestinal epithelial tight junctions by A/E pathogens could result in a loss of barrier function in the alimentary tract; however, this remains unexamined. Here we demonstrate for the first time that A/E pathogen infection results in the morphological alteration of tight junctions during natural disease. Tight junction alteration, characterized by relocalization of the transmembrane tight junction proteins claudin 1, 3 and 5, is a functional disruption; molecular tracers, which do not normally penetrate uninfected epithelia, pass across pathogen-infected epithelia. Functional junction disruption occurs with a concomitant increase in colon luminal water content. The effects on tissue are dependent upon the bacterial type III effector EspF (E. coli secreted protein F), because bacteria lacking EspF, while able to colonize, are defective for junction disruption and result in decreased proportions of water in the colon compared with wild-type infection. These results suggest that the diarrhoea induced by A/E pathogens occurs as part of functional tight junction disruption. [source] M cells and associated lymphoid tissue of the equine nasopharyngeal tonsilEQUINE VETERINARY JOURNAL, Issue 3 2001P. KUMAR Summary The aim of this study was to characterise the morphological and histochemical features of equine nasopharyngeal tonsillar tissue. Nasal and oropharyngeal tonsillar tissue has been described as the gatekeeper to mucosal immunity because of its strategic location at the entrance to the respiratory and alimentary tracts. A combination of light, scanning and transmission electron microscopy has revealed the presence of follicle-associated epithelium (FAE) overlying lymphoid tissue of the equine nasopharyngeal tonsil caudal to the pharyngeal opening of the guttural pouch. Membranous microvillus (M) cells were identified in the FAE on the basis of short microvilli, an intimate association with lymphocytes, cytoplasmic vimentin filaments and epitopes on the apical surface reactive with lectin GS I-B4 specific for ,-linked galactose. CD4-positive lymphocytes were scattered throughout the lamina propria mucosae as well as forming dense aggregates in the subepithelial part. The central follicular area was heavily populated with B lymphocytes and the dome and parafollicular areas contained both CD4- and CD8-positive lymphocytes. CD8-positive lymphocytes were also present in the epithelium and, together with B lymphocytes, in small numbers in the lamina propria mucosae. These observations indicate that the nasopharyngeal tonsil is potentially an important mucosal immune induction site in the horse and an appropriate target forintranasally administered vaccines. [source] | ||||||||||||||||