981 resultados para small intestine
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BACKGROUND: Alveolar echinococcosis (AE) is caused by the larval stage (metacestode) of Echinococcus multilocularis. The domestic dog can act as a definitive host and harbor adult cestodes in its small intestine or become an aberrant intermediate host carrying larval stages that may cause severe lesions in the liver, lungs and other organs with clinical signs similar to AE in humans. CASE PRESENTATION: A case of canine AE, affecting the liver and prostate with development of multilocular hydatid paraprostatic cysts and possible lung involvement is described in an 8-year-old neutered male Labrador retriever dog.The dog presented with progressive weight loss, acute constipation, stranguria and a suspected soft tissue mass in the sublumbar region. Further evaluation included computed tomography of the thorax and abdomen, which revealed cystic changes in the prostate, a paraprostatic cyst, as well as lesions in the liver and lungs. Cytological examination of fine-needle aspirates of the liver, prostate and paraprostatic cyst revealed parasitic hyaline membranes typical of an Echinococcus infection and the presence of E. multilocularis-DNA was confirmed by PCR. The dog was treated with albendazole and debulking surgery was considered in case there was a good response to antiparasitic treatment. Constipation and stranguria resolved completely. Six months after the definitive diagnosis, the dog was euthanized due to treatment-resistant ascites and acute anorexia and lethargy. CONCLUSIONS: To the authors' knowledge, this is the first publication of an E. multilocularis infection in a dog causing prostatic and paraprostatic cysts. Although rare, E. multilocularis infection should be considered as an extended differential diagnosis in dogs presenting with prostatic and paraprostatic disease, especially in areas where E. multilocularis is endemic.
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CASE DESCRIPTION A 7-year-old 573-kg (1,261 -lb) Swiss Warmblood gelding was evaluated because of signs of acute abdominal pain. CLINICAL FINDINGS Physical examination revealed a markedly distended abdomen with subjectively reduced borborygmi in all abdominal quadrants. A large, gas-distended viscus was present at the pelvic brim preventing complete palpation of the abdomen per rectum. Ultrasonographic evaluation could not be safely performed in the initial evaluation because of severe signs of abdominal pain. TREATMENT AND OUTCOME Ventral midline celiotomy was performed, and right dorsal displacement of the ascending colon was corrected. Progressive signs of abdominal pain after surgery prompted repeat ventral midline celiotomy, and small intestinal incarceration in a large, radial mesojejunal rent was detected. The incarceration was reduced, but the defect was not fully accessible for repair via the celiotomy. Repair of the mesenteric defect was not attempted, and conservative management was planned after surgery; however, signs of colic returned. A standard laparoscopic approach was attempted from both flanks in the standing patient, but the small intestine could not be adequately mobilized for full evaluation of the rent. Hand-assisted laparoscopic surgery (HALS) allowed identification and reduction of jejunal incarceration and repair of the mesenteric rent. Although minor ventral midline incisional complications were encountered, the horse recovered fully. CLINICAL RELEVANCE HALS techniques should be considered for repair of mesenteric rents in horses. In the horse of this report, HALS facilitated identification, evaluation, and repair of a large radial mesenteric rent that was not accessible from a ventral median celiotomy.
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Two genetically variant forms of rat "acid" beta-galactosidase were found to differ in isoelectric point and pH dependence, but not in thermostability or sensitivity to inhibition by p-mercuribenzoate (PMB). The results of two backcrosses and an intercross indicated that the isoelectric focusing phenotypes are controlled by two codominant alleles at a single autosomal locus, for which we propose the name Glb-1. No significant linkage between Glb-1 and albino (LG I), brown (LG II), or hooded (LG VI) was observed. Strain-specific differences in total levels of kidney beta-galactosidase were detected, but it is not yet known whether the variation is controlled by genes linked to Glb-1. Experiments in which organ homogenates were incubated with neuraminidase indicated that the genetically variant forms do not result from differences in sialylation, though sialylation does appear to be largely responsible for the presence of multiple bands within each phenotype and for differences in the banding patterns of beta-galactosidases derived from different organs. The beta-galactosidase present in the bands used for Glb-1 typing resembles human GM1 gangliosidase (GLB1) with respect to pH optimum, substrate specificity, and susceptibility to inhibition by PMB. It also appears that Glb-1 is homologous with the Bgl-e locus of the mouse. In rats as in mice the genetically variant bands of beta-galactosidase are active at acid pH and have relatively high isoelectric points. In both species these bands are readily detectable in kidney homogenates, and can be revealed in homogenates of liver or spleen following treatment with neuraminidase. The presence of the same beta-galactosidase bands in homogenates of rat kidney and small intestine as well as in neuraminidase-treated homogenates of liver and spleen suggests that the Glb-1 variants differ by one or more point mutations in the structural gene for "acid" beta-galactosidase.
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Objective: To determine alterations in quantities and distributions of natural antimicrobials following ischemia-reperfusion injury. We hypothesized that these compounds would be upregulated in areas of small intestine where changes in permeability and cellular disruption were likely and where protective mechanisms would be initiated. Methods: Rats with ischemia-reperfusion underwent superior mesenteric artery clamping and reperfusion. Shams were subjected to laparotomy but no clamping. Ileum and jejunum were harvested and sectioned, and subjected to fluorescence deconvolution microscopy for determinations of content and localization of rat beta defensins, 1, 2, 3; rat neutrophil protein-1; and cathelicidin LL-37. Modeling was performed to determine cellular location of antimicrobials. Results: Ischemia-reperfusion increased neutrophil defensin alpha (RNP-1) in jejunum; rat beta defensin 1 was increased 2-fold in ileal mucosa and slightly reduced in jejunal mucosa; rat beta defensin 2 was reduced by ischemia-reperfusion in ileum, but slightly increased in jejunum; rat beta defensin 3 was concentrated in the muscularis externa and myenteric plexus of the jejunum; ischemia-reperfusion did not alter cathelicidin LL-37 content in the small intestine, although a greater concentration was seen in jejunum compared with ileum. Conclusion: Ischemia-reperfusion injury caused changes in antimicrobial content in defined areas, and these different regulations might reflect the specific roles of jejunum versus ileum.
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Inhibition of local host immune reactions is one mechanism contributing to tumor progression. To determine if alterations in local immune functioning occur during colon carcinogenesis, a model mucosal immune response, type I hypersensitivity against the intestinal parasite Trichinella spiralis, was first characterized in normal mice and then examined during experimental colon carcinogenesis. Segments of sensitized colon mounted in Ussing chambers and challenged with T. spiralis-derived antigen resulted in a rise in short-circuit current ($\rm\Delta I\sb{sc}$) that was antigen-specific and inhibited by furosemide, implicating epithelial Cl$\sp-$ secretion as the ionic mechanism. The immune-regulated Cl$\sp-$ secretion by colonic epithelial cells required the presence of mast cells with surface IgE. Inhibition of potential anaphylactic mediators with various pharmacological agents in vitro implicated prostaglandins and leukotrienes as the principal mediators of the antigen-induced $\rm\Delta I\sb{sc}$, with 5-hydroxytryptamine also playing a role. Distal colon from immune mice fed an aspirin-containing diet (800 mg/kg powdered diet) ad libitum for 6 wk had a decreased response to antigen, confirming the major role of prostaglandins in generating the colonic I$\sb{\rm sc}$. To determine the effects of early stages of colon carcinogenesis on this mucosal immune response, mice were immunized with T. spiralis 1 day after or 8 wk prior to the first of 6 weekly injections of the procarcinogen 1,2-dimethylhydrazine (DMH). Responsiveness to antigenic challenge was suppressed in the distal colon 4-6 wk after the final injection of DMH. One injection of DMH was not sufficient to inhibit antigen responsiveness. The colonic epithelium remained sensitive to direct stimulation by exogenous Cl$\sp-$ secretagogues. Decreased antigen-induced $\rm\Delta I\sb{sc}$ in the distal colon was not due to systemic immune suppression by DMH, as the proximal colon and jejunum maintained responsiveness to antigen. Also, rejection of a secondary T. spiralis infection from the small intestine was not altered. Tumors eventually developed 25-30 wk after the final injection of DMH only in the distal portions of the colon. These results suggest that early stages of DMH-induced colon carcinogenesis manipulate the microenvironment such that mucosal immune function, as measured by immune-regulated Cl$\sp-$ secretion, is suppressed in the distal colon, but not in other regions of the gut. Future elucidation of the mechanisms by which this localized inhibition of immune-mediated ion transport occurs may provide possible clues to the microenvironmental changes necessary for tumor progression in the distal colon. ^
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A heterodimeric 760-kDa dermatan sulphate proteoglycan tentatively named PG-760 was characterized as a product of keratinocytes, endothelial cells, and fibroblasts. The two core proteins of 460 kDa and 300 kDa are linked by disulphide bridges, and both carry one or only very few dermatan sulphate chains. Different antisera against PG-760 were used in the present study to investigate the distribution in selected murine tissues by light and electron microscopy. PG-760 immunostaining was observed in cornea (epithelium including basement membrane, stroma, and Descemet's membrane), skin, mucosa of the small intestine, Engelbreth-Holm-Swarm (EHS)-tumour (matrix and cells), and the smooth muscle layers of uterus, small intestine, and blood vessels. No staining was observed in capillaries, striated muscles, and liver parenchyma including the central vein. The expression of PG-760 in EHS-tumour was also demonstrated after extraction with 4 M guanidine and partial purification by diethylaminoethyl (DEAE)-chromatography. We conclude that this novel proteoglycan exhibits a unique tissue distribution being a constituent of some but not all basement membranes, of some other extracellular matrices, and additionally, of all investigated smooth muscle layers.
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Gastroenteropancreatic neuroendocrine tumors (NETs) often present as liver metastasis from a carcinoma of unknown primary. We recently showed that primary NETs from the pancreas, small intestine and stomach as well as their respective liver metastases differ from each other by the expression profile of the three genes CD302, PPWD1 and ABHB14B. The gene and protein expression of CD302, PPWD1, and ABHB14B was studied in abdominal NET metastases to identify the site of the respective primary tumors. Cryopreserved tissue from NET metastases collected in different institutions (group A: 29, group B: 50, group C: 132 specimens) were examined by comparative genomic hybridization (Agilent 105 K), gene expression analysis (Agilent 44 K) (groups A and B) and immunohistochemistry (group C). The data were blindly evaluated, i.e. without knowing the site of the primary. Gene expression analysis correctly revealed the primary in the ileum in 94 % of the cases of group A and in 58 % of group B. A pancreatic primary was predicted in 83 % (group A) and 20 % (group B), respectively. The combined sensitivity of group A and B was 75 % for ileal NETs and 38 % for pancreatic NETs. Immunohistochemical analysis of group C revealed an overall sensitivity of 80 %. Gene and protein expression analysis of CD302 and PPWD1 in NET metastases correctly identifies the primary in the pancreas or the ileum in 80 % of the cases, provided that the tissue is well preserved. Immunohistochemical profiling revealed CD302 as the best marker for ileal and PPWD1 for pancreatic detection.
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Eosinophils natively inhabit the small intestine, but a functional role for them there has remained elusive. Here, we show that eosinophil-deficient mice were protected from induction of Th2-mediated peanut food allergy and anaphylaxis, and Th2 priming was restored by reconstitution with il4(+/+) or il4(-/-) eosinophils. Eosinophils controlled CD103(+) dendritic cell (DC) activation and migration from the intestine to draining lymph nodes, events necessary for Th2 priming. Eosinophil activation in vitro and in vivo led to degranulation of eosinophil peroxidase, a granule protein whose enzymatic activity promoted DC activation in mice and humans in vitro, and intestinal and extraintestinal mouse DC activation and mobilization to lymph nodes in vivo. Further, eosinophil peroxidase enhanced responses to ovalbumin seen after immunization. Thus, eosinophils can be critical contributors to the intestinal immune system, and granule-mediated shaping of DC responses can promote both intestinal and extraintestinal adaptive immunity.
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BACKGROUND Neuroendocrine neoplasms (NENs) are difficult to diagnose. We used SwissNET data to characterise NEN patients followed in the two academic centres of western Switzerland (WS), and to compare them with patients followed in eastern Switzerland (ES) as well as with international guidelines. METHOD SwissNET is a prospective database covering data from 522 consecutive patients (285 men, 237 women) from WS (n = 99) and ES (n = 423). RESULTS Mean ± SD age at diagnosis was 59.0 ± 15.7 years. Overall, 76/522 experienced a functional syndrome, with a median interval of 1.0 (IQR: 1.0-3.0) year between symptoms onset and diagnosis. A total of 51/522 of these tumours were incidental. The primary tumour site was the small intestine (29%), pancreas (21%), appendix (18%) and lung (11%) in both regions combined. In all, 513 functional imaging studies were obtained (139 in WS, 374 in ES). Of these, 381 were 111In-pentetreotide scintigraphies and 20 were 68Ga-DOTATOC PET. First line therapy was surgery in 87% of patients, medical therapy (biotherapy or chemotherapy) in 9% and irradiation in 3% for both regions together. CONCLUSION Swiss NEN patients appear similar to what has been described in the literature. Imaging by somatostatin receptor scintigraphy (SRS) is widely used in both regions of Switzerland. In good accordance with published guidelines, data on first line therapy demonstrate the crucial role of surgery. The low incidence of biotherapy suggests that long-acting somatostatin analogues are not yet widely used for their anti-proliferative effects. The SwissNET initiative should help improve compliance with ENETS guidelines in the workup and care of NEN patients.
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After intestinal bypass, the mucosa of the in-continuity segment (ICS) of intestine undergoes adaptive hyperplasia which results in increased absorptive function per length of intestine. In the present study, 70% of the small intestine was bypassed in rats to determine if intestinal muscle also adapts after bypass. To determine the effect of bypass on intestinal transit, a poorly absorbed marker substance was introduced into the orad portion of the ICS or bypassed loop (BL). Significantly less marker (P < 0.05) was passed from the ICS into the colon in 50 minutes in fed rats at 14 days compared to at 3 days after bypass. In 150 minutes there was more marker in the colon of fed rats at 3 and 14 days but not at 35 days after bypass than in control. In the BL, transit was slowed significantly in fed rats at 3 and 35 days and in fasted rats at 3 days but not 35 days after bypass compared to control. The circular muscle from the BL and the distal but not proximal portion of the ICS developed significantly more carbachol-stimulated force in vitro at 35 but not 3 days after bypass compared to unoperated but not sham-operated controls. At 35 days after bypass, the muscle layers had a greater muscle wet weight and protein content compared to both unoperated and sham-operated control in both the proximal and distal portions of the ICS. Similarly, there was more muscle in histological sections of the BL and distal portion of the ICS at 35 days after bypass compared to either control. Nonetheless, at 35 days after bypass actomyosin content as a fraction of muscle weight or total protein content was not different from control. The results support the hypothesis that there was a functional adaptation, i.e. slowed transit in fed rats that allowed more time for absorption. Feeding caused slowed transit in the BL as well as the ICS. Other results suggest that an increased amount of functional muscle formed in the distal portion of the ICS after bypass. ^
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The etiological role of enterotoxigenic E. coli (ETEC) in diarrheal diseases of man and domestic animals is firmly established. Besides the production of enterotoxins (ST and LT), ETEC produces other important virulence factors; the colonization factor antigens (CFAs). CFAs mediate the attachment of ETEC to the epithelial cells of the small intestine, and this favors colonization by the bacteria and facilitates delivery of the enterotoxins to the intestinal cells.^ The production of enterotoxin and CFA is determined by plasmids and has been found to be restricted to a select number of E. coli serotypes.^ In this work, plasmid DNA analysis was performed in twenty-three CFA/II-producing enterotoxigenic Escherichia coli strains and their spontaneous CFA/II-negative derivatives. In some cases, strains lost the high molecular weight plasmid and also the ability to produce CFA/II, ST and LT. In other cases there was a deletion of the plasmid, which produced strains that were CFA/II('-), ST('-), LT('-) or CFA/II('-), ST('+), LT('+).^ The CFA/II plasmid from strain PB-176 (06:H16:CFA/II('+), ST('+), LT('+)) was transferred by transformation into E. coli K12 with concomitant transfer of the three characteristics: CFA/II, ST and LT.^ A physical map of the prototype CFA/II:ST:LT (pMEP60) plasmid was constructed by restriction endonuclease analysis and compared to plasmids from three other CFA/II-producing strains. A CFA/II-negative (but ST and LT positive) deletion derivative of pMEP60 (pMEP30) was also included in the map. The four CFA/II plasmids analyzed had a common region of approximately 30 kilobase pairs. The toxin genes were approximately 5 kbp apart and about 20 kbp from the common region. The information given by this physical map could be of great value when constructing a clone that will express the CFA/II genes but not the toxin genes. ^
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Cytochrome P450s, a superfamily of heme enzymes found in most living organisms. They are responsible for metabolism of many therapeutic drugs, industrial pollutants, carcinogens, and additives to foodstuffs, as well as some endogenous compounds including fatty acids and steroids. First pass drug metabolism studies represent mainly liver and small intestine elimination, and are viewed as the standard to predict therapeutic outcome. However, drug plasma levels determined after administration do not always correlate with therapeutic efficacy of the drug. Therefore, a possible explanation may come by understanding drug metabolism in extrahepatic tissues and/or at the site of drug action. Identification and characterization of novel tissue specific isoforms of P450 generated by alternative splicing of known P450 genes or as yet unidentified genes is essential to predict pharmacological outcome of drugs or the fate of a carcinogen that act at sites remote from liver. ^ Using RT-PCR, brain-specific cytochrome P450s were detected in samples of human autopsy brain. So far, we have identified two human brain variants including P450 2D7 and P450 1A1. We have shown the presence of the P450 1A1 brain specific splice variant in African Americans, Caucasians and Indians albeit different patterns of liver to brain variant ratio were seen distributed throughout each population. Interestingly, the splice variant was detected only in the brain but not in any other tissues from the same individual. Homology modeling was used to compare the variant 3D structure to the liver form structure and differences in the substrate access channels and substrate binding sites were noticed. Automated computational docking was used to predict the metabolic fate of the potent carcinogenic substrate, benzo[a]pyrene. P450 1A1 brain variant showed no binding orientations that could produce the active metabolite, whereas P450 1A1 liver form did reveal orientations capable of generating active carcinogenic product. In vitro P32 labeling studies verified the docking predictions. Therefore, the data support the hypothesis that P450 brain splice variants mediate the metabolism of xenobiotics by mechanisms distinct from the well-studied liver counterparts. ^
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It is generally believed that 1,25(OH)2D3, bound to its receptor (VDR) contributes to calcium homeostasis by regulating active calcium absorption in the proximal small intestine. However, studying patients with hereditary vitamin D-resistant rickets (HVDRR) provided investigators with a better understanding of VDR's role in calcium homeostasis. HVDRR patients have inactivating mutations in the VDR, and as a consequence they develop hypocalcemia, hyperparathyroidism and severe rickets. However, these phenotypes can be corrected if the patients are given IV infusions of calcium or dietary calcium. This raises the question of what is the physiological significance of VDR-regulated active calcium absorption if calcium homeostasis can be restored independently of the VDR. ^ In order to distinguish the contribution of VDR in the proximal small intestine to overall calcium homeostasis, I generated transgenic mice expressing the human VDR (hVDR) exclusively in the proximal small intestine of mVDR-/- mice by using an hVDR-expressing transgene driven by the duodenal-specific adenosine deaminase enhancer (hVDR+/mVDR-/-). hVDR+/mVDR-/- mice expressed transcriptionally active hVDR only in the proximal small intestine and responded to 1,25(OH)2D3 by up-regulating expression of TRPV6 and calbindin D9K, genes involved in calcium absorption. Furthermore, ligated duodenal loop assays determined that calcium absorption in hVDR+/mVDR-/- mice was as responsive to 1,25(OH)2D3 as in WT mice. Despite having a functional hVDR in the proximal small intestine, hVDR+/mVDR-/- mice were hypocalcemic, had hyperparathyroidism, and were rachitic when fed a normal rodent diet at weaning, as were the mVDR-/- mice. However, when fed a high calcium, phosphorus, and lactose diet (rescue diet), the hVDR+/mVDR-/- mice responded more effectively than the mVDR-/- mice by down-regulation of parathyroid hormone production and by a greater increase in bone mineralization. Furthermore, when three-month-old rachitic mice were fed a rescue diet for 3 weeks, serum calcium and bone mineral content were normalized in hVDR+/mVDR-/- mice, but not in mVDR-/- mice. ^ In conclusion, hVDR expression enabled young mice to better use the rescue diet than mVDR-/- mice. Expression of transgenic hVDR also protected the ability of older mice to respond to the rescue diet despite the absence of the VDR elsewhere in the intestinal tract. I propose that because hVDR+/mVDR-/- mice responded better than mVDR-/- mice to the rescue diet, it is likely that VDR expression in the proximal small intestine is necessary in nutritional (insufficient dietary calcium) and physiological (age) conditions when passive calcium absorption is inadequate. ^
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Objective. Gastrointestinal Stromal Tumors (GISTs) are rare mesenchymal tumors of the gastrointestinal (GI) tract with spindled cell, epithelioid, or occasionally pleomorphic morphology. The primary objective of this paper is to describe the demographic and clinical characteristics and survival among GIST patients registered at the University of Texas M.D. Anderson Cancer Center (MDACC). ^ Methods. This cohort study includes 783 consecutive patients diagnosed with GIST from 1995 to 2007. Demographic, clinical and survival information were obtained from the MDACC cancer registry. ^ Statistical Analysis. Kaplan-Meier survival curves, univariate and multivariate Cox proportional hazards analysis were conducted to estimate survival and identify prognostic clinical factors associated with survival. Results. The age at diagnosis of MDACC GIST cases ranged from 17 to 91 with a mean of 57 years and a male-to-female ratio of 1.3:1. The racial distribution was whites 77%, African-Americans 9.5%, Hispanics 9.3% and other races 4.2%. Fifty per cent of the GISTs arose from stomach, 35% small intestine, 7% retroperitoneal space, 6% colorectal and 2% were omentum and mesentery. About half of the tumors were less than 10 cm in size. Fifty eight per cent of the tumors were localized whereas 36% were metastatic. MDACC GIST patients were generally comparable to SEER patients, but, on the average, were 7 years younger than SEER patients and were predominantly whites. ^ Stratification of 783 GIST cases by year of diagnosis based on the introduction of imatinib treatment in 2000 revealed that 60% of the GIST cases were first diagnosed between 2000 and 2007 whereas, 40% were first diagnosed between 1995 and 1999. There was a significant difference between the two cohorts in the distribution of race, GIST symptom, tumor size, tumor site, and stage of the tumor at diagnosis. The 1- and 5-year survival was 93% and 59% in the 1995–2007 cohort. Multivariate Cox regression analysis identified age at diagnosis (p<0.001), female sex (p=0.047), tumor size (p=0.07), multiple cancers (p=0.002), and GIST diagnosed between 2000 and 2007 (p<0.001) were significantly associated with survival. Approximately, 58% of the cases were treated with imatinib whereas 42% did not receive imatinib in 2000–2005 cohort. There was a significant difference in survival between imatinib and non-imatinib groups and in the distribution of tumor size categories, stage of the tumor at diagnosis and cancers before the diagnosis of GIST. The 1- and 5-year survival for imatinib patients was 99% and 73% and was 91% and 63% for non-imatinib patients. Multivariate Cox regression analysis of the 2000–2007 cohort identified, age at diagnosis and tumor stage as possible prognostic factors associated with survival.^
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The prevalence of antirotavirus antibodies in chickens and turkeys in the Gonzales, Texas and Llano, Texas areas was studied. Caged layer chicken flocks were found to have a prevalence of 64% when samples were taken randomly. This compares to 45% in chicken broiler breeder flocks and 92% in turkey breeding flocks. The natural occurrence of turkey rotavirus infection in two separate field studies showed an increase in mortality varying from 9% to 45% above expected death losses. Clinically, pasted vents, lacitude, and general malaise were noted in affected poults. Lesions noted on post mortem examination were; slight ballooning of the small intestine, excessively large ceca, and mild hyperemia of the small and large intestines.^ The use of maternal antibody from simian rotavirus immunized chickens' eggs for preventing murine rotavirus infection in infant mice was investigated. There was a reduction from 91% to 15% incidence when infant mice were treated twice daily with egg yolk immunoglobulin.^ The need for a convenient, easily grown and rapidly reproducing model for avian and mammalian rotaviruses led to the use of coturnix chicks. The turkey rotavirus was adapted to the quail chicks be serial passage. Transmission and scanning electron microscopy as well as micropathological methods were used in the study of the pathogenesis of rotavirus infection in quail and infant mice. ^