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PubMed1995

The fowl adenovirus type 1 (CELO) virus-associated RNA-encoding gene: a new ribozyme-expression vector.

A new system for hammerhead ribozyme (Rz) expression was examined in which fowl adenovirus type 1 (CELO) virus-associated RNA (CELO VA RNA) was used as a vector for the incorporation of Rz to target the mRNA of secreted alkaline phosphatase (SEAP) both in vitro and in vivo. The Rz gene was integrated into the CELO VA RNA between the internal promoter boxes A and B; apparently this did not interfere with its transcription. Rz integrated into CELO VA RNA and, lacking the viral sequences, exhibited the same activity in vitro, Consequently, CELO VA RNA sequences did not inhibit the integrated Rz activity in vitro. In vivo experiments were carried out with human 293 cells by co-transfection with plasmids containing Rz and SEAP. Inhibition of enzyme activity was 50% in 48 h. We conclude that CELO VA RNA may be used for effective expression of hammerhead Rz.

Alkaline Phosphatase↗

PubMed1990

Expression of fowl adenovirus type 10 antigens in Escherichia coli.

In an attempt to construct a genetic map of the fowl adenovirus (FAV) and to determine which viral proteins are natural immunogens in chickens and hence may be relevant to protective immunity we have constructed an expression library of FAV type 10 DNA. The genomic DNA was partially digested with the restriction endonuclease Sau3A, and this DNA was inserted into the 3' terminal end of the beta-galactosidase gene in a plasmid vector. To date, approximately 600 clones have been identified that express FAV type 10 antigens as determined by immunological screening with rabbit antisera to purified virus, including one that has amino acid homology with the 100 kDa protein of human adenovirus type 5. These antigen positive clones were found to contain DNA from FAV type 10 genome as determined by hybridisation to FAV DNA. These clones will allow the further characterisation of FAV and possibly the identification of potential vaccine molecules.

Animals↗

PubMed1996

Comparison by restriction enzyme analysis of three fowl adenoviruses of varying pathogenicity.

Restriction enzyme studies have been used to divide the fowl adenoviruses (FAV) into 5 groups - A, B,C,D and E. More detailed restriction enzyme studies of a series of group E FAV field isolates showed that these methods could differentiate between mildly and hypervirulent FAV belonging to this group. We have mapped the genomes of the hypervirulent (CFA 40) and two of the mildly virulent FAV (CFA 44 and CFA 3), using 11 different restriction enzymes: HindIII, BglII, XbaI, NdeI, SpeI, DraI, NotI, StuI, NheI, SfiI, and AvrII. Comparison of the three maps showed that the CFA 3 genome was approximately 3.5 kb smaller than that of CFA 44 and CFA 40. This size difference was discounted as a likely cause of the reduced pathogenicity of CFA 3 as the other mildly virulent virus, CFA 44, was the same size as the hypervirulent CFA 40. Other variations between the three viruses occurred in the region of the hexon and 100 K genes, but further studies are required to determine the significance of these variations in pathogenicity.

Animals↗

PubMed1996

Determination of monensin, salinomycin and narasin in muscle, liver and eggs from domestic fowl using liquid chromatography-electrospray mass spectrometry.

A method is presented for the simultaneous determination of the three ionophores, monensin, salinomycin and narasin in muscle, liver and eggs from domestic fowl. Samples are homogenised in methanol and any ionophores present are extracted into toluene-hexane. The extracts are concentrated and injected into a bench-top electrospray LC-MS system. Chromatography is carried out using an end-capped reversed-phase column, with a mobile phase consisting a mixture of acetonitrile, methanol, tetrahydrofuran, trifluoroacetic acid and water. Using single-ion monitoring, the ionophores can be detected down to the 1 ng/g level.

Animals↗

PubMed1983

Serotoninergic drugs affect prolactin and growth hormone secretion in the domestic fowl.

Adult fowl of both sexes injected with the monoamine oxidase inhibitor pargyline showed elevated circulating prolactin concentrations and reduced growth hormone concentrations. Young cockerels injected with the serotonin agonist quipazine and the antagonist methysergide showed responses consistent with a serotoninergic stimulatory control of prolactin. Injection of the serotonin precursor tryptophan and the serotonin re-uptake blocker imipramine resulted in elevated prolactin and reduced growth hormone levels. The similarities and differences in the control of prolactin and growth hormone in birds and mammals were discussed.

Animals↗

PubMed1984

Involvement of alpha 1- and alpha 2-adrenergic receptors in the hypothalamo-pituitary-ovarian axis of the domestic fowl, Gallus domesticus.

The alpha 1-adrenergic receptor ligand, 3H-WB4101, and the alpha 2-adrenergic receptor ligand, 3H-para-aminoclonidine, were utilized at a 1.0 nM incubation concentration to determine relative alpha 1-and alpha 2-adrenergic receptor binding by cell membranes from selected tissues within the brain, ovary and oviduct of the domestic fowl. Significant specific alpha 1-adrenergic binding was observed in the hypothalamus, anterior pituitary, pineal, cerebrum and cerebellum but only the cerebrum had significant alpha 2-receptor binding. Significant levels of alpha 1-adrenergic binding were observed in the granulosa cells of the three largest ovarian follicles and in the postovulatory follicle. Significant specific alpha 2-adrenergic binding was measured in the infundibulum, magnum, isthmus and shell gland of the oviduct. The physiological implications of alpha-adrenergic receptors in these tissues are discussed.

Animals↗

PubMed1991

Relationship between thinning of eggshells and reduction in number of eggs produced after administration of some saluretic drugs in domestic fowls.

1. The effect of some diuretic drugs (acetazolamide, hydrochlorothiazide, chlorthalidone, furosemide, ethacrynic acid and amiloride) on eggshell formation and egg production in domestic fowls were investigated. All of the tested compounds significantly inhibited eggshell formation, furosemide being the most potent drug. 2. The number of laid eggs was also reduced by several of the diuretics. There was a correlation between reduction of shell thickness and number of eggs (r = 0.77; P less than 0.01). 3. If the tested diuretics were subdivided into two groups according to their different modes of action, where furosemide, ethacrynic acid and amiloride represent sodium transport inhibitors, and acetazolamide, hydrochlorothiazide and chlorthalidone (contributory action of the two latter) are inhibitors of carbanhydrase, the highest correlation coefficient (r = 0.96) between reduction of shell thickness and egg production was found for sodium transport inhibitors. The corresponding correlation coefficient for carbanhydrase inhibitors (r = 0.44) was not significant. 4. The probable mechanisms of action of the diuretics on eggshell formation and ovulation are discussed.

Animals↗

PubMed1992

Inhibition of eggshell formation in domestic fowl by indomethacin: relation to calcium and prostaglandin metabolism in the eggshell gland mucosa.

1. The involvement of prostaglandins in eggshell formation in the domestic fowl was investigated by considering the effects of the drug indomethacin on the calcium metabolism on the eggshell gland. Egglaying birds were given a single dose (100 mg) of indomethacin at the beginning of shell calcification. Fourteen hours later the birds were sacrificed and the effects of the drug were determined. There was a 21% reduction in the shell thickness of the egg present in the shell gland at the time of slaughter (P < 0.01). The calcium content of the eggshell gland mucosa was increased to 153% (P < 0.01) of the controls. In the treated birds, there was 43% more calcium (P < 0.05) present in the shell gland lumen (recovered by rinsing with Tris buffer) than in the gland lumen of control birds. Total calcium in blood plasma was decreased by 15% (P < 0.05). In homogenate and three subcellular fractions (MIII, FI and FIII) of eggshell gland mucosa, 45Ca uptake was significantly reduced (i.e. by 29%, 25%, 17% and 35%, respectively). A significant reduction (62-66%) was also observed in the synthesis of PGF2 alpha, PGE2 and TxB2 by eggshell gland mucosa homogenate. 2. The effects of indomethacin treatment on the calcium metabolism of the avian eggshell gland are discussed and compared with p,p-DDE-induced alterations in calcium metabolism and prostaglandin synthesis by the eggshell gland.

Animals↗

PubMed1992

Furosemide decreases eggshell thickness and inhibits 45Ca2+ uptake by a subcellular fraction of eggshell gland mucosa of the domestic fowl.

1. Administration of furosemide to egg-laying domestic fowl (single p.o. dose 100 mg/bird) caused a decrease in the thickness of the shell of eggs laid the next day. 2. Furosemide administration in vivo caused a 37% decrease in the uptake of 45Ca2+ by a subcellular fraction of the eggshell gland mucosa (mainly composed of cell fragments and plasma membranes). 3. Furosemide treatment did not affect calcium concentrations in plasma or shell gland fluid but did cause a significant increase in the calcium concentration in shell gland mucosa. 4. It is concluded that the eggshell-thinning effect of furosemide is localized to an inhibitory effect on plasma membrane calcium transport in the eggshell gland mucosa. 5. These findings are discussed and compared with the effects of other drugs and toxic substances known to influence eggshell formation in birds.

Animals↗

PubMed1995

Effects of methyl mercury at different dose regimes on eggshell formation and some biochemical characteristics of the eggshell gland mucosa of the domestic fowl.

Eggshell formation and egg production in domestic fowl were studied following the administration of methyl mercury (two dose regimes: 5 mg daily for 6 consecutive days and 1 mg daily for 50 consecutive days). A daily oral dose of 5 mg of methyl mercury for 6 consecutive days induced significant eggshell thinning and deformation and inhibited egg production. Uptake of 45Ca and synthesis of prostaglandins by a homogenate of eggshell gland mucosa from methyl-mercury-treated birds were significantly reduced, as was the calcium content of blood plasma. A daily oral dose of 1 mg of methyl mercury administered for 50 consecutive days also induced eggshell deformation and thinning and reduced egg production. This dose did not, however, have significant effects on the following: 45Ca uptake and prostaglandin synthesis by a homogenate of the eggshell gland mucosa; 45Ca uptake by a homogenate of duodenal mucosa; the Ca content of the blood plasma, shell gland mucosa or shell gland lumen; the HCO3- content of the shell gland lumen or the specific gravity of tibia. Methyl mercury added in vitro to a homogenate of eggshell gland mucosa significantly stimulated the synthesis of prostaglandins PGF2 alpha and PGE2. Addition of mercury chloride to the same type of preparation stimulated the synthesis of PGF2 alpha at the expense of thromboxane (TxB2) synthesis. Administration of 5 mg methyl mercury for 6 consecutive days seemed to reduce the availability of calcium for eggshell formation. This effect could have been due to a direct inhibitory effect of methyl mercury on calcium uptake from the gastrointestinal tract and/or to mobilization of medullary bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

PubMed2006

Phagocytotic removal of apoptotic endocrine cells by folliculostellate cells and its functional implications in clusterin accumulation in pituitary colloids in helmeted guinea fowl (Numida meleagris).

The different cell types in the anterior pituitary behave as dynamic populations. The gland maintains a continuous renewal of cells to ensure a dynamic balance between cell division, differentiation, growth arrest and apoptosis. Apoptosis is a frequent event in the anterior pituitary in which unwanted cells are eliminated without affecting neighboring cells. We examined the link between apoptosis and the occurrence of colloids in the guinea fowl (Numida meleagris) pituitary gland and the relationship of clusterin accumulation in the colloids. S-100 positive folliculostellate (FS) cells were found surrounding colloids. Apoptotic cells detected by single stranded DNA (ssDNA) immunohistochemistry were observed in the whole anterior pituitary and preferentially near colloid masses. Clusterin protein was detected in endocrine cells, FS cells and in the colloids. In situ hybridization showed clusterin mRNA in endocrine cells and FS cells. Simultaneous localization was performed to determine whether clusterin mRNA and ssDNA within anterior pituitary was present within the same cell. Clusterin mRNA was not detected in apoptotic cells but was present in neighboring surviving cells. At the ultrastructural level, numerous endocrine cells at different stages of apoptosis were found phagocytosed by FS cells. Our results suggest that clusterin is produced by endocrine cells for cytoprotection before death. Apoptotic endocrine cells are phagocytosed by FS cells and digested by their lysosomal enzymes. In FS cells, clusterin interacts and aggregates with by-products of digestion that subsequently become stored in colloid as a residual body.

Animals↗

PubMed2005

Opioid receptor function in social attachment in young domestic fowl.

Opioid systems are implicated in social attachment processes. This research sought to determine the functional contribution of each opioid receptor in modulating social attachment/separation distress. Following ICV administration of opiate probes, 7-day-old cockerels were isolated from conspecifics for a 3 min test period under either a mirror or no-mirror condition. Vocalizations served as the measure of separation-stress. Opioid receptor probes included: the mu agonist DAMGO (0.02, 0.19, 1.95 nmol), the mu antagonist CTOP (0.009, 0.09, 0.9 nmol), the delta agonist SNC80 (0.3, 1.0, 3.0 micromol), the delta antagonist naltrindole (0.2, 2.2, 22.2 nmol), the kappa agonist U50, 488 (1, 30, 100 nmol), the kappa antagonist norBNI (1.3, 13.6, 136.1 nmol), the NOP agonist N/OFQ (0.01, 0.1, 1.0 nmol), and the NOP antagonist UFP-101 (0.1, 1.0, 10.0 nmol). DAMGO attenuated separation distress vocalizations. No other drug probe enhanced or attenuated distress vocalizations. Further, the non-selective opiate antagonist naloxone (0.3, 8.3, 27.5 nmol) did not exacerbate distress vocalizations. These results suggest that only the mu receptor modulates social attachment in young domestic fowl.

Analgesics, Opioid↗

PubMed2004

Preen gland function in layer fowls: factors affecting morphology and feather lipid levels.

The effects of age and external factors on preen gland morphology and feather lipid concentrations in layer fowl (Gallus domesticus) have not previously been described. This work examines how floor substrate, whether a bird is feather pecked or not, and age influence both gross and histological morphology. Furthermore, the effects of age, beak trimming and floor substrate on feather lipid concentration (mg lipid per g feathers) are investigated. Neither absolute nor relative preen gland weight were reliably affected by floor substrate or feather pecked status. However, these parameters were strongly affected by changes in bird age and related body weight changes. The microstructures of the gland also increased consistently with age. Feather lipid concentration generally increased with age. Feather lipid was strongly influenced by the presence or absence of a dustbathing substrate. Of all the parameters tested here, the age and growth of the bird had the greatest effects on preen gland development. Feather lipid concentration is also influenced by age, and by the presence or absence of a dustbathing substrate.

Aging↗

PubMed2005

Molecular cloning, expression profile and functional implications of clusterin in the pituitary gland of helmeted guinea fowl (Numida meleagris).

Clusterin is shown to contain putative amphipathic alpha-helices that mediate hydrophobic interactions with numerous types of molecules and may be involved in clearance of cellular debris caused by cell injury or death. To assess this function in vivo, we have cloned the full-length cDNA encoding guinea fowl (Numida meleagris) clusterin and studied its synthesis and expression pattern in specific cell types in pituitary. Quantity of clusterin mRNA expressed in pituitary and endocrine tissues was quantified by real-time PCR. Highest levels were detected in gonads. In situ hybridization showed clusterin mRNA in endocrine cells and folliculostellate cells. Clusterin protein detected by immunohistochemistry was observed in endocrine cells, folliculostellate cells and in colloid. The expression pattern suggests that clusterin is produced by endocrine cells for cytoprotection. Degenerating endocrine cells are phagocytosed by folliculostellate cells and digested by their lysosomal enzymes. In folliculostellate cells clusterin interacts and aggregates with by-products of digestion that subsequently become stored in colloid.

Amino Acid Sequence↗

PubMed2004

Characterization of SCAR markers of Eimeria spp. of domestic fowl and construction of a public relational database (The Eimeria SCARdb).

This study reports the development and characterization of 151 sequence characterized amplified region (SCAR) markers for the seven Eimeria species that infect the domestic fowl. From this set, 84 markers are species-specific and 67 present partial specificity. The complete nucleotide sequence was derived for all markers, revealing the presence of micro- and minisatellite repetitive units in 22 SCARs, with up to five distinct repeat units being observed per marker. Only 15 markers showed significant hits in similarity searches against public sequence databases, thus confirming their anonymous and non-coding character. Finally, a relational database of the markers (the Eimeria SCARdb) was developed and made available on the Internet, providing a valuable resource of SCAR markers that can be useful for molecular diagnosis, and also for epizootiological, genetic variability and genome mapping studies.

Animals↗

PubMed2005

Effect of isoflavone from Flemingia vestita (Fabaceae) on the Ca2+ homeostasis in Raillietina echinobothrida, the cestode of domestic fowl.

The alcoholic crude root-peel extract of Flemingia vestita and its major isoflavone, genistein, have been shown to have a vermifugal/vermicidal effect by causing a flaccid paralysis accompanied by alterations in the structural architecture of the tegumental interface and metabolic activity in Raillietina echinobothrida, the cestode of domestic fowl. In the present study, the crude root-peel extract and pure genistein were tested in vitro with respect to Ca2+ homeostasis and the occurrence of some metal ions was detected in the parasite. Live cestodes were incubated in pre-defined concentrations of the crude root-peel extract, genistein and praziquantel (as reference drug), till the paralysis time with simultaneous maintenance of respective controls. In the parasite tissue, a significant amount of Ca2+ (approximately 400 microg/g dry tissue wt) was found to be present besides magnesium, iron, zinc, lead and chromium, whilst manganese, cadmium and nickel were below the level of detection. The Ca2+ concentration was decreased significantly by 39%-49%, in the parasite tissue exposed to the test materials in comparison to the respective controls. There was also an increase in Ca2+ efflux by 91%-160% into the culture medium under similar treatments. The changes in Ca2+ homeostasis may be related to the rapid muscular contraction and consequent paralysis in the parasite due to the anthelmintic stress caused by the phytochemicals of F. vestita.

Animals↗

PubMed2005

Effects of non-steroidal anti-inflammatory drugs on pain-related behaviour in a model of articular pain in the domestic fowl.

The optimum doses of carprofen, flunixin, ketoprofen and sodium salicylate for the treatment of inflammatory pain were determined in domestic fowl using the microcrystalline sodium urate model of articular pain. The response criteria were the changes in pain-related behaviour over 60 min commencing 1 h after an intra-articular injection of sodium urate and an intramuscular injection of a range of doses of each of the drugs. The minimum effective doses for carprofen, flunixin and ketoprofen, respectively, were 30, 3 and 12 mg kg(-1). The minimum dose for sodium salicylate ranged from 100 to 200 mg kg(-1) and did not fully restore normal behaviour.

Animals↗

PubMed2007

Isolation and molecular characterization of a Brazilian strain of Borrelia anserina, the agent of fowl spirochaetosis.

Borrelia anserina the agent of fowl spirochaetosis, has a worldwide distribution, where it is transmitted by Argas spp. ticks. The present study reports the first molecular characterization and in vitro isolation of an avian spirochaete strain from Brazil, presumably identified as B. anserina originated from naturally infected Argas miniatus ticks. DNA fragments of the rrs and flab genes were amplified by PCR and sequenced to determine phylogenetic similarities. The resulting sequences were 99.8% (483 of 484) and 98.7% (754 of 764) similar to GenBank corresponding sequences of B. anserina rrs and flaB genes, respectively. By neighbor-joining phylogenetic analysis, the flaB sequence of the Brazilian strain clustered in a monophyletic group with the sequence of B. anserina under 100% bootstrap support. The isolate was successfully isolated in BSK medium, with seven passages performed. The spirochaete strain isolated in the present study was genetically identified as B. anserina labeled as strain PL.

Animals↗