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At least 289 records · Page 16Linked to original sources
PubMed1984

Catecholamine-containing pancreatic islet cells of the domestic fowl. Light, fluorescence and electron microscopy, and immunohistochemistry.

In an attempt to identify pancreatic islet cells emitting formaldehyde-induced fluorescence (FIF), the pancreatic islets of the domestic fowl were studied by combined fluorescence, ultrastructural, silver-impregnation and immunohistochemical methods in the same section or in consecutive semi-thin and ultra-thin sections. The results indicate that islet cells emitting intense FIF exhibit a strongly argyrophil reaction with the Grimelius' silver method and also immunohistochemical reaction with anti-glucagon serum, but not with anti-5-HT serum. Therefore, the fowl islet A cell, a peptide hormone-producing cell, stores simultaneously catecholamine as biogenic amine. The islet B and D cells did not display any FIF, any argyrophil reaction with the Grimelius' silver method, or any immunoreactivity with anti-glucagon or anti-5-HT sera. The fluorescent but non-argyrophil cells dispersed in the exocrine acinus may well be PP cells.

Animals↗
PubMed1983

A Golgi study of the parvocellular neurons in the paraventricular nucleus of the domestic fowl.

The present study was focussed on the typology of small and medium-sized neurons in the hypothalamic paraventricular nucleus (PVN) of the domestic fowl as revealed by means of Golgi impregnation. This region is provided with different systems of neurons that can be distinguished on the basis of their location and dendritic morphology. Intraependymal neurons and CSF-contacting nerve cells are found in the periventricular layer together with bipolar elements endowed with processes extending parallel to the surface of the third ventricle. The short axons of these neurons may contact the magnocellular elements. Numerous isodendritic neurons are scattered throughout the entire PVN; these nerve cells possessing short and branched axons may be considered as local-circuit neurons. The complex intrinsic organization of the PVN of the domestic fowl might provide the structural basis for local interactions among the neuronal elements of this hypothalamic region.

Animals↗
PubMed1975

Structure and histochemistry of the normal intestine of the fowl. III. The fine structure of the duodenal crypt.

The fine structures of the development and maturation of intestinal chief cells from the duodenal crypts of the fowl has been described in detail. Three areas within the crypt can be recognised: 1) the crypt base where cell division is frequent but cell development is minimal; (2) the mid-crypt region where rapid growth and development of the cells takes place; and (3) the zone of differentiation where final developments and functional maturation occurs. The structure of the fowl's intestinal crypt is very similar to that described for the mammals. The results are discussed in relation to previous histochemical studies.

Animals↗
PubMed1981

The hypothalamic magnocellular system in the domestic fowl. A golgi and electron microscopic study.

In the rostral hypothalamus of the domestic fowl, the magnocellular neurosecretory nuclei show a peculiar differentiation. Golgi studies of the supraoptic and paraventricular nuclei of the fowl reveal at least two major cell types: 1) large multipolar neurons, and 2) small interneurons. Golgi impregnations provide a detailed cytoarchitectural picture of the large-sized cells; the latter may well correspond to the neurosecretory cells demonstrated in the same regions by selective staining, and immunocytochemical and electron microscopical techniques. Electron microscopically, neuronal perikarya are observed to contain variable amounts of neurosecretory granules (100-200 nm in diameter; mean diameter of 160 nm) scattered throughout the cytoplasm. The diameters of these granules do not differ statistically in the two principal nuclear areas examined. The perikarya of these neurons display only a few axosomatic synapses containing electron-lucent and dense-cored vesicles (70-90 nm in diameter). Numerous nerve terminals of this type also end on the dendritic ramifications in the surrounding neuropil.

Animals↗
PubMed1987

Genetic resistance to fowl cholera is linked to the major histocompatibility complex.

Chickens of the Iowa State S1 line have been selected for ability to regress Rous sarcoma virus-induced (RSV) tumors, humoral immune response to GAT (Ir-GAT), and erythrocyte antigen B. Sublines homozygous at the major histocompatibility complex (MHC), as well as F1 heterozygotes and F2 segregants, were tested for resistance to fowl cholera by challenge with Pasteurella multocida strain X73. Control of the response at high doses was associated in a preliminary study with Ir-GAT and response to RSV tumors. Genetic control of resistance to low doses of P. multocida was demonstrated via sublines and F2 segregants to be linked with genes of the B-G region. Thus, genetic control of resistance to fowl cholera in chickens after exposure to Pasteurella multocida was shown to be linked to the major histocompatibility B complex, in this first demonstration of MHC-linked resistance to bacterial disease challenge.

Alleles↗
PubMed1978

Electron cytochemistry of developing and mature eosinophils in the bone marrow of the fowl and the duck.

Enzyme cytochemical studies have been carried out on eosinophils in the fowl and the duck. Peroxidase was found in all regions of the Golgi apparatus, the rough endoplasmic reticulum and the perinuclear cisternae of the early cells. In fowl eosinophil granules irregular deposits of peroxidase and arylsulphatase final reaction product were found, but the acid phosphatase deposits were even. In the duck in contrast, peroxidase was demonstrated in the external part of the granule only. Acid phosphatase and arylsulphatase were found in both the interna and the externa of the duck eosinophil granules. An ammoniacal silver nitrate reaction for the presence of the histone arginine was also studied. Silver deposits were found occupying all regions of the granules of eosinophils from both species of bird. The presence of the hydrolytic enzymes acid phosphatase and arylsulphatase in avian eosinophil granules supports the theory that these structures are lysosomal in nature and that they correspond with mammalian eosinophils in this respect.

Acid Phosphatase↗
PubMed1985

Experimental analysis of the extensive pigmentation in the Silkie fowl embryo: evidence for an environmental regulatory process.

Heterospecific coelomic grafts, associated with the quail-chick marker system, showed that quail embryo melanoblasts exhibit the same invading behavior as Silkie fowl melanoblasts, when they came into contact with Silkie embryo organs. Thus the colonization or noncolonization of the organs of the Silkie fowl embryo by melanoblasts seems to depend on environmental cues.

Animals↗
PubMed1982

Experimental eosinophilia in domestic fowls and ducks following horse serum stimulation.

Multiple intraperitoneal injections of horse serum given to domestic fowls at five different ages resulted in eosinophilia in 55% of adults and in 36% of the younger birds, the highest individual eosinophil level reached being 50% of the differential white cell count. The primary eosinophilic response in fowls was between injections 7 and 36 and there was a secondary response between injections 32 and 72. Horse serum injections produced an eosinophilia in 88% of adult ducks with a maximum individual level of 31% of the differential white cell count. In ducks, primary and secondary eosinophilic responses occurred at injections 13 and 28 respectively.

Age Factors↗
PubMed1993

Growth rate and egg production of Creole and Rhode Island red x Creole fowls.

In Guyana 3 experiments were conducted using 1,440 chicks and 640 pullets and the same number of hens in a randomised block design to determine the growth rate, egg production, and egg fertility and hatchability of 1/2 Creole x 1/2 Rhode Island Red (CR) and 3/4 Rhode Island Red x 1/4 Creole (CRR) fowls compared with the parental strains of Creole (C) and Rhode Island Red (R) fowls. The growth rate of CR and CRR was higher than C, but lower (P < 0.05) than R. Total egg production per hen housed during the pullet year was 59.5, 106.8, 130.7 and 171.8 for C, CR, CRR and R respectively and they were all significantly (P < 0.05) different. There were no significant (P > 0.05) differences between the 4 strains for fertility and hatchability percentages of the eggs which averaged 87.8 and 88.9 respectively. The level of production was comparatively high and mortality low enough for the crossbreds to be recommended for small holder poultry development, although the feed cost of production would be higher for CRR than for CR.

Animals↗
PubMed1993

Effects of oxazepam on anxiety: implications for Fowles' psychophysiological interpretation of Gray's model.

The present dose-response study investigated the effects of the benzodiazepine oxazepam (Serax) on anxiety as measured by autonomic and self-report indices in a nonclinical sample. Given Fowles' (1980, 1988) theory that electrodermal activity primarily reflects the activity of the behavioral inhibition system (BIS) while heart rate primarily reflects the activity of the behavioral activation system (BAS), we predicted that electrodermal indices of anxiety would be more affected by oxazepam than heart rate. Psychophysiological and self-report measures were recorded prior to and following a speech stressor in subjects given placebo (n = 17), 15 mg oxazepam (n = 19), and 30 mg oxazepam (n = 17). Anxiolytic effects were found during stressed state as measured by skin conductance level but not heart rate or self-reported anxiety. Furthermore, the anxiolytic effects of oxazepam were noted only during the stressful phases of the experiment. The results are viewed as supportive of Fowles' motivational interpretation of the distinction between heart rate and electrodermal responding.

Adolescent↗
PubMed1991

Influence of chlorinated hydrocarbons, Hg2+ and methyl-Hg+ on steroid hormone receptors from eggshell gland mucosa of domestic fowls and ducks.

A series of chlorinated hydrocarbons were investigated for their ability to inhibit the binding of tritiated progesterone, dexamethasone and testosterone to their respective cytoplasmic receptors, prepared from the eggshell gland mucosa of the domestic fowl. o,p'-DDE and toxaphene were most potent in inhibiting the binding of progesterone and testosterone to their receptors, while p,p'-DDE was most potent in inhibiting the binding of dexamethasone. The effect of the latter compound on dexamethasone binding was biphasic. There were significant differences between ducks and domestic fowls in the dissociation constant (KD) and maximal number of binding sites (Bmax) for several of the steroid hormones. No effect of steroid binding was observed in the p,p'-DDE-treated ducks that were laying thin-shelled eggs. Some metals were also tested for their ability to inhibit progesterone binding. Hg2+ was most potent (IC50 = 5.8 x 10(-5) M) in this respect, while Cd2+, Pb2+ and Al3+ inhibited the binding only when administered in very high concentrations (10(-3) M). Me-Hg+ was less potent than Hg2+. It is concluded that chlorinated hydrocarbon pesticides may interact with several different steroid hormone receptors. These findings are discussed in relation to some reproductive and other hormonal disturbances observed in birds and mammals.

Animals↗
PubMed1991

Virus-induced pancreatic cancer in guinea fowl. An electron-microscopical study.

Pancreatic tumors were induced in guinea fowls inoculated with virus strain Pts-56. Sequential high-resolution light microscopic and ultrastructural studies revealed consecutive occurrence of alterations in the pancreas of the infected birds. From the second month p.i., there were nonobligatory, unspecific focal degenerative changes in acinar units that were replaced by tubular complexes, lined with centroacinar-like cells. From the third month, proliferation of ductule structures with mucin-producing or mucin-nonproducing epithelium occurred, giving rise to cystic and papillary adenomas. From the fourth to sixth months, pancreatic adenocarcinomas and poorly differentiated carcinomas arose. The cells of the serous adenomas ultrastructurally resembled the normal pancreatic centroacinar and ductular cells with their regular glandular arrangement on basal lamina, elongated nuclei with finely dispersed heterochromatin, scanty cytoplasmic organelles, microvilli, and occasional cilium. The cells of the mucinous tumors showed similarities to ductal cells with their darker cytoplasmic matrix, larger number of small mitochondria, microfilaments, vesicles, mucin granules, and extensive interdigitations. The cells of the pancreatic carcinomas revealed irregularities in glandular formation, nuclear polymorphism, low cytodifferentiation, and ultrastructural abnormalities, but in most cases retained basic fine structural similarities to the epithelium of the pancreatic ductal system. The present results indicate that the centroacinar cell is the cell of origin of the broad spectrum of pancreatic neoplasms with various differentiation and malignancy induced in guinea fowl by virus strain Pts-56.

Adenocarcinoma↗
PubMed2002

A survey of the inter- and intraspecific RAPD markers of Eimeria spp. of the domestic fowl and the development of reliable diagnostic tools.

Coccidiosis of domestic fowl is a protozoan disease, caused by seven distinct species of the genus Eimeria, which is responsible for important economic losses in poultry production. In order to select RAPD primers for the discrimination of these seven Eimeria species, we carried out an initial screening using samples of E. acervulina, E. tenella and E. maxima. Out of 150 primers tested, 110 generated band profiles specific for each one of these species. A subset of 14 oligonucleotides were also tested for the simultaneous differentiation of the seven species, resulting in 11 discriminative primers. The intraspecific discrimination was assessed for five different species, using samples from different geographic regions including three continents. Numerous primers exhibited highly discriminative band profiles containing strain-specific markers, with a higher variability being observed among strains of E. acervulina than among E. tenella and E. maximastrains. However, no major differences were observed in the band patterns from strains collected in locations near to one another compared to strains originating from distantly located regions. Because RAPD is a technique performed under low stringency conditions, it suffers from poor reproducibility. Aiming at obtaining more reliable markers that might be universally used, we started an effort to convert species-specific RAPD fragments into SCAR markers. An initial conversion of 25 RAPD markers into SCARs, followed by validation of their specificity, resulted in 14 totally new Eimeria species-specific markers that can be used for the molecular diagnosis of the seven species that infect domestic fowl. This work represents a first step in the development of a set of species-specific SCARs that will be useful as tools for molecular diagnosis, genome mapping, and genetic diversity studies.

Animals↗
PubMed2003

Extracellular matrix of different composition supports the various splenic compartments of guinea fowl ( Numida meleagris).

The extracellular matrix (ECM) of the spleen of the guinea fowl has been studied by immunohistochemistry. Each splenic compartment contains a different composition of ECM. Reticular-fiber-specific collagen III is expressed by the red pulp and thymus-dependent periarterial lymphatic sheath, but silver impregnation reveals a reticular-fiber-like structure in the periellipsoidal white pulp (PWP) where collagen III is absent. The penicillar capillaries of one central artery are enveloped by a single branching sheath or sleeve: the ellipsoid or Schweigger-Seidel sheath. The shape of the sleeve shows more resemblance to a deer antler than to an ellipsoid; it emerges at the beginning of the penicillar capillaries and ends at the edge of the PWP. It is wrapped by a novel discontinuous basement-membrane-like structure that expresses tenascin and that is named the capsule of the Schweigger-Seidel sheath (CSS). The cuboidal-shaped inner cell layer of the ellipsoid can be identified by a novel monoclonal antibody: BID3. BID3-positive stellate-shaped cells also occur in the PWP, suggesting that this cell population has migratory capability. Monoclonal antibody KIF8 recognizes an ECM component in the ellipsoid not only of guinea fowl, but also of chicken and quail, and may thus identify an ellipsoid-specific antigen. Collagen I is associated with both the basement membrane of the penicillar capillary and the CSS, whereas collagen III is present only in the CSS. Laminin is expressed in the red pulp, but its staining pattern does not indicate the presence of the "ring fibers", which suggests the absence of sinuses. Fibronectin is the only ECM molecule studied that occurs in every splenic compartment, indicating extensive intrasplenic cell migration.

Aging↗
PubMed1998

The major late promoter and bipartite leader sequence of fowl adenovirus.

The region of the fowl adenovirus serotype 10 (FAV-10) genome containing the major late promoter (MLP) and leader sequences was determined and appropriate genomic fragments were cloned and sequenced. A TATA box was identified and the location of the putative transcription start site was determined. By using synthetic primers from the transcription start site in conjunction with oligonucleotides from the coding regions of the penton base and hexon genes, cDNA was produced from late mRNA isolated from cell cultures infected with FAV-10 at 24 h post-infection. The resulting cDNA was cloned and sequenced and the leader sequences thus identified. It was found that the FAV-10 MLP utilized only two leader sequences (a bipartite leader). By comparison with human adenoviruses (HAVs) it appeared that the second leader in HAVs was absent from the FAV-10. The second leader sequences of FAV-10 was larger than either the second or third leaders of HAVs, but was 29 basepairs shorter than the combined size of the leader sequences 2 and 3 from HAV-2. To confirm the transcription start site and leader sequences, single stranded cDNA was produced from mRNA using the primers from within the coding sequence for the penton base or hexon. A tail of dGTP's was added and cDNA synthesis was completed using an oligonucleotide from within the hexon or penton base coding sequence and a second poly-dCTP oligonucleotide. Sequencing of the resultant G-tailed DNA confirmed the location of the transcription start site as an adenosine residue 24 basepairs upstream from the 3-prime (3') end of the TATA box. Sequencing 5' of the TATA box failed to reveal any sequence similarity with the human adenovirus upstream stimulatory factor (USF). Various plasmids were constructed which placed the determined sequences of the MLP, leader, and the region upstream of the TATA box linked to the co-acetyl acid transferase (CAT) gene. These expression plasmids in transient expression assays of CAT activity in primary chicken kidney cell culture with or without FAV-10 co-infection were determined. These experiments showed that the cassette containing sequences 5' of the TATA box expressed CAT to a much greater level than cassettes not containing this upstream region and that the presence of virus significantly increased the activity of the promoter following the onset of viral DNA replication. Without the 5' region, cassettes failed to express above background levels. These results suggest that the basic structure of the fowl adenovirus MLP is similar to that of the human adenovirus although it utilizes a bipartite rather than a tripartite leader sequence.

Animals↗
PubMed1992

Regulation of flagellar motility by temperature-dependent phosphorylation of a 43 kDa axonemal protein in fowl spermatozoa.

Phosphorylation of fowl sperm proteins was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) after incubating the demembranated spermatozoa with [gamma-32P]ATP at 30 degrees C or 40 degrees C. A marked difference of phosphorylation between 30 degrees C and 40 degrees C was observed in a 43 kDa protein. This protein was slightly phosphorylated at 40 degrees C, but strongly phosphorylated at 30 degrees C in a cAMP-independent manner. The motility of demembranated spermatozoa was negligible at 40 degrees C, but vigorous movement was observed at 30 degrees C. These results showed that phosphorylation of a 43 kDa protein is likely to be a regulatory step in the maintenance of fowl sperm motility.

Animals↗
PubMed1983

Autoradiographic observations on the innervation of the carotid body of the domestic fowl.

Tritiated leucine was injected into the distal vagal ganglion of 11 domestic fowl, which survived for 12-24 h under general anaesthesia. The cells of this ganglion are known to be exclusively afferent. EM autoradiography showed that in all 11 birds the vast majority of the silver grains fell upon the nervous tissues of the carotid body. In 5 of these birds a quantitative analysis was made, using point-counting morphometry. The incidence of silver grain per unit area was found to be 26 times greater in axonal endings than in the non-nervous components, and 15 times greater in axons in transit than in non-nervous components. The difference in incidence per unit area between these nervous and non-nervous components was highly significant (P less than 0.001). Of all the observed axonal endings 77% were labelled, but there is evidence that this is a substantial underestimate of the total population of afferent endings; in one bird 88% of the endings were labelled. Of the axons in transit, 18% were labelled. This low value is believed to be related to transfer of the label to the axonal endings by the fast component of axonal transport. Afferent and reciprocal synapses occurred in labelled axonal endings, which were therefore considered to have an afferent function. 'Efferent' type synapses also occurred in labelled endings, and therefore belonged to axons which in fact were afferent in function. It is concluded that the innervation of the carotid body of the domestic fowl is almost entirely afferent, the nerve cell bodies being in the distal vagal ganglion. Only very few efferent axonal endings are present. Ultrastructural features, including synaptic morphology, appear to constitute unreliable criteria for distinguishing between afferent and efferent axonal endings in the carotid body.

Animals↗
PubMed1987

Benzodiazepine antagonist Ro 15-1788 (flumazepil) attenuates the anticonvulsant activity of diazepam in epileptic fowl.

The ability of the imidazobenzodiazepine Ro 15-1788 to displace diazepam from brain membranes in vitro and to antagonize the anticonvulsant activity of diazepam in vivo was determined in epileptic fowl. At doses of 1.0 mg/kg and higher, Ro 15-1788 significantly attenuated the anticonvulsant action of diazepam (1.0 mg/kg) in epileptic chickens. Ro 15-1788 alone exerted no anticonvulsant activity even in doses as high as 10 mg/kg. Specific binding of 10 nM [3H]diazepam to whole homogenate fractions prepared from cerebral hemispheres of epileptic fowl was inhibited by Ro 15-1788 with an IC50 of 8.5 nM and the Ki was determined to be 4.25 nM. These results suggest that Ro 15-1788 competes directly with diazepam for a binding site involved in producing anticonvulsant activity.

Animals↗