Effects of environmental temperature on thyroid hormones in the barn owl (Tyto alba).

The basic patterns of thyroid hormones [thyroxine (T4) and 3,3',5-triiodothyronine (T3)] and the T4 and T3 responses induced by thyrotropin releasing hormone (TRH) are reported in captive female barn owls (Tyto alba) during the non-breeding period. The main findings of the study, conducted on a total of 10 owls, are as follow: (1) The thyroid gland of barn owl can be stimulated by the classical TRH stimulation test. (2) T3 response was much more pronounced both under cold (around 10 degrees C) and warm (around 20 degrees C) conditions, whereas T4 response ranged so widely that we could not point out any significant change in it.

Endocrine characteristics of late pregnant hyperketonaemic ewes and their reproductive performance following the induction of ovarian cyclicity out of the breeding season.

Ketosis was diagnosed in a flock of Merino ewes that conceived from synchronised oestrus in the early autumn period. On day 140 of pregnancy the ewes were sampled for determination of betaOH-butyrate (BHB), AST, glucose, non-esterified fatty acids (NEFA), total cholesterol (TCH), insulin, T4, T3, cortisol, IGF-1 and leptin. The results were evaluated according to the number of fetuses born some days later and the presence of hyperketonaemia (BHB: > or = 1.

Reduction in the adherence of Pseudomonas aeruginosa to human buccal epithelial cells with neuraminidase inhibition.

The aim of this study was to evaluate the reduction in the adherence of 33 strains of Pseudomonas aeruginosa isolated from humans and different animals to human buccal epithelial cells with neuraminidase inhibition. Buccal epithelial cells were incubated with strains of Pseudomonas aeruginosa in the presence or absence of the neuraminidase inhibitors, 2,3-dehydro-2-deoxy-N-acetyl-neuraminic acid (DANA) or N-acetyl-neuraminic acid (NANA). Incubation of cells with bacteria in the presence of either DANA or NANA reduced bacterial adherence significantly by 35.

Partial cloning and localisation of leptin and its receptor in the one-humped camel (Camelus dromedarius).

Based on the studies and results presented here, leptin and its receptor were expressed by adipose tissue, mammary alveolar epithelial cells, liver hepatocytes, and the lining epithelium of the bile duct of the one-humped camel (Camelus dromedarius). Our observations support the biological importance of leptin in the mammary gland as well as the likely local effect of leptin on the peripheral tissues. We suggest that there may be an association between hepatic leptin and the lipogenic activity of the liver in the dromedary camel.

Serum amyloid A in geese; cloning and expression of recombinant protein.

We defined the nucleotide-sequence of the full-length goose serum amyloid A and compared it to SAA sequences of the duck. The aim of this work was to clone and express recombinant goose SAA and to produce antibody against this protein: Total RNA was isolated from goose liver and used to synthesise first strand cDNA. The coding region of the goose SAA cDNA was amplified by PCR using primers corresponding to the appropriate conservative regions of duck SAA mRNA.

Thyroid hormone metabolism in the brain of domestic animals.

The action of thyroid hormones in the brain is strictly regulated, since these hormones play a crucial role in the development and in the physiological functioning of the central nervous system. It has been shown by many authors that brain tissue represents a special site of thyroid hormone handling. A relative independence of this tissue of the actual thyroid status was shown by our research group in birds and mammals.

Feeding-unrelated factors influencing the plasma leptin level in ruminants.

The triglyceride content of lipid depots associated with the current feeding level is the primary determinant of leptin gene expression and the circulating leptin level. In laboratory rodents and primates the plasma leptin is influenced also by the age, gender and physiological status (puberty, pregnancy, lactation, postpartum period), and by the health condition such as sepsis due to Gram-negative (GN) bacteria. Some pathologic conditions with intensive cytokine release evoke an increase in plasma leptin, which is thought to depress the subsequent feed intake.

Expression of leptin and its receptors in various tissues of ruminants.

The energy metabolism of domestic animals is under the control of hormonal factors, which include thyroid hormones and leptin. Leptin signals from the periphery to the centre. It is mostly produced in the white adipose tissue and informs the central nervous system (CNS) about the total fat depot of the body.

Expression and localisation of leptin and leptin receptor in the mammary gland of the dry and lactating non-pregnant cow.

Leptin and leptin receptor were studied in the mammary gland of non-pregnant dry and lactating cows. Using RT-PCR it was demonstrated that leptin and its short (Ob-Ra) and long (Ob-Rb) receptor isoforms are expressed both in the dry and the lactating mammary gland tissue. Tissue distribution of leptin and its receptor mRNA transcripts were examined by in situ hybridisation, while the leptin protein was localised by immunohistochemistry.

Partial cloning and localization of leptin and leptin receptor in the mammary gland of the Egyptian water buffalo.

Originally an overall metabolic control was attributed to the leptin hormone, which is produced mainly by the adipose tissue. Recently, leptin gene expression was demonstrated in several additional peripheral tissues. Furthermore, several isoforms of leptin receptor were found both in the central nervous system and in the peripheral tissues.

Transcriptional regulation of iodothyronine deiodinases during embryonic development.

A single dose of chicken growth hormone (cGH) or dexamethasone acutely increases circulating T(3) levels in 18-day-old chicken embryos through a reduction of hepatic type III iodothyronine deiodinase (D3). The data in the present study suggest that this decrease in D3 is induced by a direct downregulation of hepatic D3 gene transcription. The lack of effect of cGH or dexamethasone on brain and kidney D3 activity, furthermore suggests that both hormones affect peripheral thyroid hormone metabolism in a tissue specific manner.

Relationships between force-feeding and some physiological parameters in geese bred for fatty liver.

The susceptibility of geese of different genotypes and sexes to force-feeding, some plasma biochemical parameters (thyroid hormones, cholesterol, retinoids, total protein and albumin) of force-fed geese, and the relationship between force-feeding, fat storage and the above-mentioned parameters were studied. Sixty (30 male and 30 female) geese of three genotypes (Hungarian, Landes and their crossbred called Babat Hybrid) were divided in two groups at 12 weeks of age. Geese in one group (5 males and 5 females from each genotype) received mixed feeding ad libitum.

Relationship between thyroid function and seasonal reproductive activity in mares.

The relationship between thyroid function and seasonal reproductive activity in mares was investigated by comparing plasma triiodothyronine and thyroxine concentrations in anoestrous mares and in mares with cyclic ovarian activity during the anovulatory season. In study 1, the diurnal changes in plasma triiodothyronine and thyroxine concentrations on a single day were compared in anoestrous and cyclic mares. The mean thyroxine concentrations were significantly higher (P < 0.

Characterization of the 5'-flanking and 5'-untranslated regions of the cyclic adenosine 3',5'-monophosphate-responsive human type 2 iodothyronine deiodinase gene.

The type 2 iodothyronine deiodinase (D2) catalyzes T4 activation. In humans, unlike rodents, it is widely expressed, and its action probably contributes to both intracellular and plasma T3 pools. We have isolated the 6.

Massive goitre (struma parenchymatosa) in geese.

In a goose flock consisting of 2300 birds of 6 months of age severe goitre was diagnosed. To the best of our knowledge this is the first report of naturally occurring goitre in geese, which is not related to the feeding of rapeseed meal. The major pathological findings included retarded growth and plumage development, significantly (300%) increased relative thyroid weight, fat accumulation in the mesenteric and abdominal region, and lipid infiltration of liver and kidney cells.

Cloning and expression of the chicken type 2 iodothyronine 5'-deiodinase.

The type 2 iodothyronine deiodinase (D2) is critical for the intracellular production of 3,5,3'-triiodothyronine from thyroxine. The D2 mRNA of higher vertebrates is over 6 kilobases (kb), and no complete cDNA clones have been reported. Using 5'- and 3'-rapid amplification of cDNA ends and two cDNA libraries, we have cloned the 6094-base pair full-length chicken D2 cDNA.

Inverse hierarchy of vimentin epitope expression in primary cultures of chicken and rat astrocytes: a double-immunofluorescence study.

Vimentin contributes to the cytoskeleton of different cell-types, among them glial cells. We report here that different forms of this protein, distinguishable by the monoclonal antibodies Vim3B4 and V9, are species-specifically expressed in cultures of glial fibrillary acidic protein (GFAP) positive, primary astrocytes of the chicken and rat. Most cells in the cultures co-expressed GFAP and one of the two vimentin epitopes.

3,3',5-Triiodothyronine (T3) uptake and expression of thyroid hormone receptors during the adaptation to hypothyroidism of the brain of chicken.

Thyroid hormone action in the brain is strictly regulated, since these hormones play a crucial role in the development and physiological functioning of the central nervous system. Hormone kinetics and molecular events at the nuclear receptor level during the adaptation of the brain of chicken to hypothyroidism were simultaneously investigated. Data obtained by Oldendorff's 'single-pass' technique showed a significantly higher labelled 3,3'5-triiodothyronine (125I-T3) uptake into the brain of surgically thyroidectomized (TX) 2-week-old broilers after 1 week of surgery in comparison to sham-operated (SH) and t3 supplemented (TX + T3) controls in the 10th second after the bolus injection.

Thyroid volumetric measurement and quantitative thyroid scintigraphy in dogs.

Thyroid volumetric measurement combined with quantitative 99mTc-per-technetate thyroid scintigraphy was performed in 62 clinical canine patients having suspected thyroid abnormalities. Euthyroid dogs (n = 22) had a total thyroid size of 3.60 +/- 1.

T-cell subsets in blood and lymphoid tissues obtained from fetal calves, maturing calves, and adult bovine.

Assessment of CD2, CD4, CD8 and gamma delta cell distribution among mononuclear cells obtained from the blood and lymphoid tissues of fetal calves, 0-150-day-old calves and adult cows was the focus of this investigation. The distributions of some of the lymphocyte subsets in peripheral blood showed variation in fetal and maturing calves as well as being markedly different from those observed in adult cows. We provide evidence that as early as 1 month prepartum, fetal calves have a full complement of at least four of the major T-cell subsets found in the normal bovine.

Thyroid hormones in nestling great tits (Parus major).

Plasma concentrations of thyroid hormones (T4 and T3) were examined in nestlings of the altricial great tit (Parus major), from hatching to when young birds left the nest at 16 days of age. T4 levels were approximately 1-2 ng/ml during the first 2 days after hatching and increased to reach maximal levels (9-10 ng/ml) 12 days after hatching, a time at which nestlings reach maximum body weight. Both sexes showed the same pattern.

Influence of a deficient intake of high and low degradable protein on body composition, metabolic adaptation, production and reproductive performance in early lactation dairy cows.

High-yielding dairy cows (n = 34) were divided into high (HD) and low (LD) protein degradability groups after delivery, and used for a feeding trial which lasted up to day 80 +/- 10 of lactation. The cows were regularly weighed, their body condition was scored (BCS), and their reproductive status assessed. Blood samples were taken simultaneously, and ruminal fluid was collected on the last day of the trial.

Species-specificity of glial vimentin as revealed by immunocytochemical studies with the Vim 3B4 and V9 monoclonal antibodies.

Two monoclonal antibodies directed against vimentin, Vim 3B4 and V9 could distinguish between vimentins originating from certain species, when tested on cell lines (Bohn et al, 1992). Our comparative immunohistochemical studies in the rat and chicken brain with the same antibodies suggest the coexistence of two vimentin forms in the glial cells of both species. One of these forms bearing the epitope present in the respective non-glial cell lines is present in astrocytes and Bergmann glia independently of the ontogenic state of the animal.