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At least 253 records · Page 14Linked to original sources
PubMed1996

An immunohistochemical study of the pathogenesis of virulent viscerotropic Newcastle disease in chickens.

Ten specific pathogen-free cockerels aged 8-12 months were infected by ocular instillation of 2 x 10(7) embryo-lethal doses 50% of a virulent viscerotropic strain of Newcastle disease virus (Fontana 1083 strain). The birds were killed at 24-h intervals after infection and tissues were collected for histological and immunohistochemical evaluation. The infection ran an acute course, severe clinical disease occurring within 72 h of infection. By gross and histological examination, the most severe damage detected was found to occur in lymphoid areas in a number of tissues. The greatest amounts of viral antigen detected occurred in the proventriculus, small intestine, spleen, thymus and eyelid. Immunohistochemical labelling was confined to large mononuclear cells.

Animals↗
PubMed1988

A histochemical study of the mucins in the digestive tract of the chicken.

Little is known about the distribution of glycoproteins in the digestive tube of birds. In the present study, the localization and distribution of mucins in the digestive tract of the chicken are reported. Sialo- and sulpho-mucins were widely distributed throughout the chicken digestive tube. Some of the mucous cells of the proximal segment of the proventriculus presented neutral glycoproteins; in the medial segment, surface cells containing only sialo-mucins were observed. Surface cells of the gizzard contained both sialo- and sulpho-mucins while PAS-positive material was localized in the lumen of the glands. 2 types of mucous cells were observed in the small intestine; 1 type contained only sialo-mucins and the other contained both sialo- and sulpho-mucins. In the large intestine and caecum, both types of acid mucins were present in the mucous cells. In conclusion, the distribution of glycoproteins in the chicken reported in the present study show marked differences with that reported in other avian species.

Animals↗
PubMed2003

Down-regulation of endodermal Shh is required for gland formation in chicken stomach.

During the development of the proventriculus (glandular stomach) of the chicken embryo, the endodermal epithelium invades into the surrounding mesenchyme and forms glands. The glandular epithelial cells produce pepsinogen, while the non-glandular (luminal) epithelial cells secrete mucus. Sonic hedgehog is expressed uniformly in the proventricular epithelium before gland formation, but its expression ceases in gland cells. Here we present evidence that down-regulation of Sonic hedgehog is necessary for gland formation in the epithelium using a specific inhibitor of Sonic hedgehog signaling and virus mediated overexpression of Sonic hedgehog. We also show that gland formation is not induced by down-regulation of Sonic hedgehog alone; a mesenchymal influence is also required.

Animals↗
PubMed2003

Surgical treatment of gastric impaction in farmed ostriches.

Partial or complete impaction of the proventriculus and/or the ventriculus is usually seen in juvenile ostriches. Common impaction materials include stones, sand, hay stems and leaves, and even plastic and metallic objects. Six live ostriches showing signs of impaction and three dead ones suspected to have impacted stomachs were presented to the Department of Clinical Sciences of the Faculty of Veterinary Medicine of the Aristotle University of Thessaloniki. The birds manifested anorexia, whitish and decreased urine output, scant defecation, unwillingness to rise and consume water. Clinical examination revealed distended and firm proventriculi, while radiographs showed foreign objects in the proventriculi of all birds and the ventriculus of one of them. The living birds were successfully treated surgically and medically. Autopsy of the three dead ostriches revealed severe dehydration and impaction of the stomachs. Bacteriological and parasitological examination was negative. Amendments in management practices were important to minimize losses caused by impaction of the stomachs in ostriches, while proventriculotomy remains the most effective approach to the problem.

Animals↗
PubMed2000

Application of efficient and specific gene transfer systems and organ culture techniques for the elucidation of mechanisms of epithelial-mesenchymal interaction in the developing gut.

Epithelial-mesenchymal interactions are very important in the development of the vertebrate gut. In the avian embryonic stomach (proventriculus), expression of embryonic chick pepsinogen (ECPg) gene, which is specific to developing glandular cells in stomach epithelium, is regulated by mesenchymal influence. Molecular mechanisms of tissue-specific transcriptional regulation of the ECPg gene and the molecular nature of the mesenchymal signals were analyzed using a combination of the classic organ culture system and gene transfer strategies. In the present review, three methods for the introduction of DNA into tissues are described: lipofection, electroporation and retroviral infection, and characteristics of each system are discussed.

Animals↗
PubMed1999

Growth of the digestive organs in ducks with considerations on their growth in birds in general.

1. Growth of the oesophagus, proventriculus, gizzard, intestine, liver and pancreas weight was investigated in Mallards, White Pekins, Muscovies and a Muscovy x White Pekin cross. The birds varied in age between hatching and 154 d. The data were analysed by fitting both the Janoschek growth curve and the allometric formula. 2. The growth rate of all organs, except the oesophagus, peaked earlier (30 d for Muscovies and 14 d for the other breeds) than body weight and they grew faster to any given percentage of their final weight. In contrast, oesophagus weight showed growth curve characteristics similar to body weight. 3. Oesophagus weight showed simple, slightly negative allometry. The remaining organs followed complex allometry that can approximately be described by 2 allometric stages. The 1st phase was isometric to positive allometric. The 2nd showed marked negative allometry. 4. These growth patterns are assumed to be generally present in birds.

Aging↗
PubMed1999

Performance and gastro-intestinal response of broiler chickens fed on cereal grain-based foods soaked in water.

1. Two experiments were carried out to investigate the addition of 1 3 kg water per kg air-dry mash diets containing high proportions (600 to 700 g/kg) of ground cereal grains (wheat, barley or oats) on broiler performance and the structure and function of the gastro-intestinal tract. 2. Chicks at the age of 7 d were fed on the wheat-, barley- or oats-based diets in the dry or wet forms for 35 d. Food and water intakes were recorded daily while body weight was measured weekly. Two birds from each treatment were killed each week to measure gut size and the viscosity of gut contents. Tissue samples from various digestive segments were histo-morphologically examined to determine the thickness of tissue layers, size of tissue glands, villa heights, crypt depths and thickness of tunica muscularis. Crypt cell proliferation rate (CCPR) for each segment was also determined using a metaphase arrest technique. 3. The results from both experiments showed that wetting food significantly (P<0.05) increased food intake, total water intake and body weight gain of broiler chickens. The body weight gains of birds were proportional to their food intakes so that the efficiency of food utilisation was similar for all treatments. Dry matter retention of food tended to increase in birds given wet food from 7 to 21 d but not thereafter, compared to the dry-fed birds. Although water intake from the water bottle was significantly (P<0.05) reduced in birds given wet food, total water intakes from the water bottle plus that from food were significantly (P<0.05) higher in the wet-fed birds than in the dry-fed birds. The ratio of total water to dry food intake was, however, similar in both feeding regimens. 4. The fresh empty weight of the gut was increased by wet-feeding while its relative weight to body weight and the length of gut was not affected by dietary treatments. Significantly greater development of the tissue glands in the proventriculus and gizzard was observed in the birds given wet food; this was associated with the reduced thickness of the muscular layer of these segments. An increase in villus height was also observed in duodenum, small intestine, caeca and colon of birds given wet food, compared to those given dry food. CCPR was significantly (P<0.05) reduced by wet-feeding throughout the digestive tract. This was associated with a significant decrease in the mean viscosity of the gut contents and the concentration of volatile fatty acids (VFAs) in the caeca. 5. Wetting diets based on cereal grains caused a significant improvement in the performance of broiler chickens. The mechanism of the beneficial effects of wet feeding could be attributed to the decreased viscosity of gut contents; the greater development of the layer of villi in the digestive segments and the reduced CCPR in the crypts of the epithelium.

Aging↗
PubMed2004

Proventricular adenocarcinoma in a Humboldt penguin (Spheniscus humboldti) and a great horned owl (Bubo virginianus); identification of origin by mucin histochemistry.

Cases of proventricular neoplasm in a Humboldt penguin (Spheniscus humboldti) and a great horned owl (Bubo virginianus) were observed. Microscopically, the neoplastic cells formed branching tubules or acini in both cases. Galactose oxidase-Schiff (GOS) staining revealed that the cytoplasm of the normal surface epithelium and surface mucosubstances of the proventriculus adjacent to the neoplasm were positive in both cases. The neoplastic cells in both cases were also classified as GOS-positive. Therefore, the two proventricular neoplasms in this report were diagnosed as proventricular adenocarcinoma that arose from the proventricular surface epithelium. This study suggests that the mucosubstances, which the neoplastic cells produced, were a useful index for identifying the origin of the neoplastic cells in the birds.

Adenocarcinoma↗
PubMed1997

The influence of environmental temperature on in vivo limestone solubilization, feed passage rate, and gastrointestinal pH in laying hens.

Several studies were conducted to determine whether suppression of in vivo limestone solubilization was partially responsible for the reduction of shell quality under conditions of high environmental temperatures. In Experiment 1, excreta from hyperthermic and thermoneutral hens fed three levels of Ca (3.5, 4.3, and 5.2%) at two cycling environmental temperatures (averaging 28.3 and 26.1 C) were analyzed for percentage in vivo limestone solubilization. Hens in Experiment 2 received diets containing 3.9% Ca at 32.8 and 18.3 C. Rate of feed passage and gastrointestinal pH were also measured in Experiment 2. Experiment 3 evaluated the influence of temperature (22.2 and 30.0 C) and feed consumption on percentage limestone solubilization when Ca intake was held constant. In vivo limestone solubilization was influenced by Ca level in Experiment 1, but not by temperature. Hyperthermic hens solubilized a higher percentage of limestone than thermoneutral hens in Experiment 2, but it was concluded that this was due to a difference in Ca consumption and not due to temperature directly. When Ca intake was held constant in Experiment 3, there was no difference in limestone solubilization at the temperatures tested. Rate of feed passage was 16.6% slower in the hyperthermic hens. Crop, proventriculus, and upper small intestine pH were similar at each temperature, but gizzard pH was significantly lower in the hyperthermic hens. It was concluded that the high environmental temperatures used in the present studies did not suppress in vivo limestone solubilization.

Animals↗
PubMed1997

Effects of inorganic adsorbents and cyclopiazonic acid in broiler chickens.

Previous studies with cyclopiazonic acid (CPA) have indicated that this mycotoxin strongly adsorbs onto the surface of a naturally acidic phyllosilicate clay (AC). The objective of this study was to determine whether AC (and similar adsorbents) could protect against the toxicity of CPA in vivo. Acidic phyllosilicate clay, neutral phyllosilicate clay (NC, or hydrated sodium calcium aluminosilicate), and a common zeolite (CZ, or clinoptilolite) were evaluated. One-day-old broiler chicks consumed diets containing 0 or 45 mg/kg CPA alone or in combination with 1% AC, NC, or CZ ad libitum from Day 1 to 21. Body weight, feed consumption, feed:gain, hematology, serum biochemical values, and enzyme activities were evaluated. Compared to controls, CPA alone reduced body weight at Day 21 by a total of 26% and resulted in a significantly higher feed:gain ratio. Toxicity of CPA was also expressed through increased relative weights of kidney, proventriculus, and gizzard. Also, there were some alterations in hematology, serum biochemical values, and enzyme activities. Treatment with inorganic adsorbents did not effectively diminish the growth-inhibitory effects of CPA or the increased weights of organs, although there was some protection from hematological, serum biochemical, and enzymatic changes produced by CPA. The results of this study suggest that in vitro binding of CPA to clay does not accurately forecast its efficacy in vivo; the reasons for this discrepancy are not clear, but they may be related to differences in clay binding capacity and ligand selectivity for CPA in vitro vs in vivo. Predictions about the ability of inorganic adsorbents to protect chickens from the adverse effects of mycotoxins should be approached with caution and should be confirmed in vivo, paying particular attention to the potential for nutrient interactions.

Adsorption↗
PubMed2006

Expression and function of Wnt5a in the development of the glandular stomach in the chicken embryo.

The epithelium of the chicken embryonic glandular stomach (proventriculus) differentiates into both a glandular and a luminal epithelium, the cells of which express specific marker genes. The subsequent formation and differentiation of the glands then proceed under the influence of the mesenchyme. To search for possible candidates for the mesenchymal factors involved, we have now investigated the expression and function of Wnt5a in this process. Our current results show that Wnt5a is expressed in the mesenchyme during active gland formation and that overexpression of this gene in ovo results in the increased and ectopic expression of some of the marker genes of the luminal and glandular epithelia. In particular, the overexpression of Wnt5a markedly enhances the expression of the embryonic chicken pepsinogen gene, a marker of the glandular epithelium, indicating its role as a mesenchymal factor that regulates the differentiation of the proventricular epithelium.

Animals↗
PubMed1996

Role of the Yersinia pestis hemin storage (hms) locus in the transmission of plague by fleas.

Yersinia pestis, the cause of bubonic plague, is transmitted by the bites of infected fleas. Biological transmission of plague depends on blockage of the foregut of the flea by a mass of plague bacilli. Blockage was found to be dependent on the hemin storage (hms) locus. Yersinia pestis hms mutants established long-term infection of the flea's midgut but failed to colonize the proventriculus, the site in the foregut where blockage normally develops. Thus, the hms locus markedly alters the course of Y. pestis infection in its insect vector, leading to a change in blood-feeding behavior and to efficient transmission of plague.

Animals↗
PubMed1992

Megabacteriosis in exhibition budgerigars.

Megabacteriosis is a common cause of illness and death in exhibition budgerigars. The clinical signs are variable but include weight loss, difficulty in swallowing, vomiting, diarrhoea and sudden death due to haemorrhage. Significant lesions are confined to the proventriculus which becomes inflamed, dilated and ulcerated, and loses its normal architecture, and to the gizzard in which there are degenerative changes in the koilin layer.

Animals↗
PubMed1992

Fumonisin toxicity in broiler chicks.

The effects of dietary fumonisin B1 were evaluated in young broiler chicks. The experimental design consisted of 5 treatments each with 9 randomly allotted male broiler chicks. Day-old chicks were fed diets containing 0 (feed control), 100, 200, 300, or 400 mg fumonisin B1/kg feed for 21 days. Response variables measured were chick performance, organ weights, serum biochemistry, and histologic parameters. Body weights and average daily gain dramatically decreased with increasing dietary fumonisin B1, and liver, proventriculus, and gizzard weights increased. Diarrhea, thymic cortical atrophy, multifocal hepatic necrosis, biliary hyperplasia, and rickets were present in chicks fed diets containing fumonisin B1. Serum calcium, cholesterol, and aspartate aminotransferase levels all increased at higher fumonisin dietary levels. Results indicate that fumonisin, from Fusarium moniliforme culture material, is toxic in young chicks.

Animal Feed↗
PubMed1979

Mn2+ ions pass through Ca2+ channels in myoepithelial cells.

1. Intracellular recordings were made from the myoepithelial cells of the proventriculus of the marine polychaete worm Syllis spongiphila. Over-shooting responses were elicited either by carbamylcholine added to the bathing medium or by directly applied intracellular current pulses. 2. In control artificial sea water (ASW) directly applied current pulses elicited regenerative responses of 68-119 mV in amplitude and 70-1800 ms in duration; these responses were associated with contractions of the myoepithelial cells. 3. Both pharmacologically and electrically elicited responses were reversibly abolished in Ca-free ASW and were unaffected by TTX or low-sodium solutions. Regenerative responses were elicited by direct intracellular stimulation in calcium-free ASW containing 1 mM-Ba2+ or 10 mM-Sr2+. Directly elicited responses were blocked reversibly in ASW containing calcium and 15-20 mM-Co2+ or 2.5-10 mM-Ni2+; they were blocked irreversibly in ASW containing calcium and 10 mM-La3+ or 100 microM-Zn2+. 4. Regenerative responses were elicited in Ca-free solutions containing 10-50 mM-Mn2+; these responses were not associated with contractions, were consistently of longer duration than responses elicited in control ASW, and were blocked by 20 mM-Co2+ or 10 mM-La3+. The overshoots of Mn2+ responses elicited in both Na-free and Na-containing, Ca-free solutions increased as the external concentration of Mn2+ was increased, with a slope of about 27 mV per 10-fold change in concentration of Mn2+. In Ca-containing solutions the slope was reduced to about 15 mV per 10-fold change. 5. The results indicate that the myoepithelial cells generate Ca-spikes and that Mn2+ ions, in addition to Sr2+ and Ba2+ ions, pass through the Ca2+ channels of the myoepithelial cell membranes. Although Mn2+ can replace Ca2+ in generating spikes, it apparently cannot replace Ca2+ in initiating contraction, and it many compete with Ca2+ in activating repolarization of the cell.

Action Potentials↗
PubMed1994

An occurrence of stomach impaction in ostriches (Struthio camelus) on a farm in Zambia associated with high mortality.

Fifty-one ostriches (Struthio camelus), 6 weeks old, were imported from Namibia and introduced onto a farm in Zambia. Soon after introduction, most of the birds manifested clinical symptoms such as anorexia and diarrhea and 19 birds died within 1 week. The proventriculus and gizzard in the 4 dead birds were full of solid masses of lucerne hay mixed with maize and consequently the gizzard was extremely impacted by them. Neither pathogenic bacteria nor parasites were detected from the autopsied birds and 8 fecal samples. After diagnosis, the ostrich feed was improved and a demulcent was given immediately; then all ostriches that remained on the farm recovered. In conclusion, these data confirmed that the present case was stomach impaction in ostriches.

Animal Feed↗
PubMedDate not supplied

Infectious bursal disease virus and proventriculitis in broiler chickens.

Acute necrotic proventriculitis is a naturally occurring disease of broiler chickens that causes proventricular rupture during routine evisceration. Although infectious bursal disease virus (IBDV) has been implicated, it has not been proven to be a direct cause of this disease. To further study the role of IBDV in proventriculitis, proventriculi and bursas were collected during both acute and chronic phases of naturally occurring proventriculitis and from chickens experimentally infected with seven different [BDV strains. All tissues were examined for IBDV by light microscopy, immunohistochemistry (IHC), and real time reverse transcriptase(RT)-polymerase chain reaction (PCR) and for apoptosis by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling method (TUNEL). Tissues from naturally occurring proventriculitis had bursal and proventricular lesions. Two out of four bursas had no IHC-stainable IBDV antigen or RT-PCR detectable IBDV sequences. No proventriculus had IBDV detectable by any of these methods. Bursas from chickens experimentally infected with IBDV had microscopically evident lesions, IBDV was detectable by IHC and RT-PCR, and strong IHC staining for apoptosis was present. Proventriculi from these experimentally exposed chickens had no lesions, low levels of IBDV detectable by IHC or RT-PCR, and very little IHC-stainable apoptosis. We conclude that naturally occurring proventriculitis can occur in the absence of IBDV and that the IBDV strains tested do not directly produce proventriculitis or induce increased proventricular apoptosis.

Animals↗
PubMed2005

Reproduction of proventriculitis in commercial and specific-pathogen-free broiler chickens.

Proventriculitis was studied by experimentally reproducing the disease in broiler chickens. One-day-old infectious bursal disease virus (IBDV) and infectious bronchitis virus (IBV) antibody positive commercial broilers and 1-day-old antibody negative specific-pathogen-free (SPF) broilers were orally gavaged with proventricular homogenates produced from the proventriculi of broilers with proventriculitis. At 7 and 14 days, both commercial and SPF broilers had enlargement of the proventriculus with necrosis of the glandular epithelium and lymphocytic infiltrates in the proventricular glands. SPF broilers exposed to the proventricular homogenates developed infectious bursal disease, and IBDV was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). They also were positive by RT-PCR to IBV and developed nephritis. Commercial broilers developed mild nephritis but not bursal disease and were negative for IBDV and positive for IBV by RT-PCR. Both homogenate-inoculated commercial and SPF chickens were negative for reovirus and Newcastle disease virus by RT-PCR and variably positive for adenovirus by PCR. Bacteria were not identified in histologic sections, nor were they isolated from affected proventriculi. Indirect fluorescent antibody assay using convalescent sera detected intracytoplasmic staining in the proventricular glandular epithelial cells. Examination of thin sections of proventriculi using electron microscopy identified virus-like particles approximately 120 nm in diameter within the cytoplasm of these cells at 7 days after inoculation. Passage of proventricular homogenate filtrates in chicken embryos for virus isolation caused stunting, and allantoic fluid from these eggs was positive for IBV by RT-PCR.

Animals↗