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Biomedical subjects

A Madej

Publications and source records attributed to A Madej.

At least 55 records · Page 3Linked to original sources

Vanadium poisoning of cattle with basic slag. Concentrations in tissues from poisoned animals and from a reference, slaughterhouse material.

In northern Sweden, 23 heifers out of 98 cattle died of acute vanadium toxicity in a 10-day period. Eight months earlier a pasture had been fertilized with basic slag, containing 3% vanadium. The fertilizer was laid on the surface without being ploughed in. Mainly heifers, and some cows, were fed with basic slag-contaminated fresh hay. The first signs of illness appeared 11 days later, and the first case of death appeared 14 days after the initial clinical signs. The signs were diffuse and difficult to interpret. Inappetence, black diarrhea, lethargy, dehydration and spontaneous abortions occurred. Further, pulmonary lesions, conjunctivitis, neurological disturbances such as depression, leg incoordination, and paralysis of the hind limbs and face were also noted. Although feeding with the contaminated hay was stopped at the outbreak of the toxicity, the 23 animals died or had to be slaughtered, and at necropsy of another heifer 4 weeks later, large amounts of basic slag were still found in the alimentary tract. High vanadium concentrations were found in the liver, kidneys, spleen and urine, 5.9, 5.5, 1.9 and 4.8 mg/kg w.w., respectively. In bone tissue (coccygeal vertebrae), the highest value in an acutely poisoned heifer was 0.680 mg/kd d.w., in the same range as that of an experimentally poisoned sheep. Surviving heifers were more affected than cows; the state of health of these heifers gradually deteriorated and, therefore, a few were slaughtered 3 months later. Because of residual neurological disturbances and decreased milk production, the rest of the herd was slaughtered 5 months after the outbreak, and samples were collected and analyzed. Elevated vanadium concentrations were found in the organs, especially in the spleen, where values of 1.40 and 1.42 mg/kg w.w. were found in 2 heifers at 3 months. The values in heifers (n = 6) were decreased 5 months after the outbreak. The median concentrations were somewhat higher in the liver than in the spleen, and lowest in the kidney (0.244, 0.213 and 0.058 mg/kg w.w., respectively). In the organs of the cows (n = 24), which were less exposed, the corresponding values were 0.012, 0.095 and 0.013 mg/kg w.w., respectively. Vanadium concentrations were also determined in livers of cows and calves at regular slaughter in four geographic regions of Sweden. In one of the regions, where basic slag (with 3% vanadium) had been used for many years, the values were significantly higher than those in the other regions. In a material of 293 specimens, an upper reference limit of 0.012 mg/kg liver w.w., with a 90% confidence interval of 0.011-0.019 mg/kg w.w., was found to be normal for cattle in Sweden. Concentrations above the Highest Swedish Reference Value, 0.019 mg/kg liver can be considered elevated. Vanadium-containing basic slag used as fertilizer caused poisoning in a herd of cattle and its regional use was detectable in livers from cattle at regular slaughter. Such fertilizer must be applied in a proper way. It should be ploughed in and any direct contact of grazing animals with the hazardous fertilizer should be prevented.

Abattoirs↗

Effects of long-term treatment with enalapril or hydralazine on the renin-angiotensin-aldosterone system and fluid balance in dogs with naturally acquired mitral valve regurgitation.

OBJECTIVE: To study long-term effects of enalapril, an angiotensin-converting enzyme inhibitor, and hydralazine, an arteriodilator, on renin-angiotensin-aldosterone system and fluid balance before and after administration of furosemide. ANIMALS: 22 dogs with clinical signs of congestive heart failure (CHF) attributable to mitral regurgitation. PROCEDURE: After initial examination, 12 dogs received enalapril and 10 received hydralazine. Dogs were re-examined 3 weeks and 6 months after initial examination. Furosemide was added after the 3-week examination, and at 6 months, dogs had received furosemide for at least 4 months. RESULTS: Angiotensin II and aldosterone plasma concentrations were low before treatment, and only aldosterone became significantly decreased after enalapril monotherapy. Concentrations of both hormones and heart rate increased in dogs receiving hydralazine monotherapy, and fluid retention was evident. After long-term treatment with either of the 2 drugs together with furosemide, angiotensin II and aldosterone values increased in both groups. Natriuresis and kaliuresis developed in all dogs, with greatest effect in those receiving enalapril and furosemide. These dogs had decreased plasma sodium concentration, whereas potassium concentration was equally decreased in both groups. After 6 months, the enalapril group, but not the hydralazine group, had increased cardiac size. All dogs had moderate reduction of weight and were azotemic, although changes were more pronounced in those of the hydralazine group. CONCLUSION: The 2 drugs have different effects on the renin-angiotensin-aldosterone system and fluid balance in dogs with CHF.

Aldosterone↗

Endocrine changes during group housing of primiparous sows in early pregnancy.

The effect of group housing sows during early pregnancy on maternal endocrine changes and on embryonic survival was studied. Twenty crossbred (Swedish Yorkshire x Swedish Landrace) primiparous sows were used. On day 11 +/- 1 of pregnancy 3 unacquainted sows were randomly assigned to a single pen measuring 3 m x 3 m in area. A fourth sow in each group was housed in an individual pen and used as a control. This procedure was repeated 5 times to collect data from 5 animals in each rank as well as in a control group. Blood samples were collected from the day before grouping to day 5 after grouping for cortisol, corticosteroid-binding globulin (CBG), progesterone (P4), oestradiol-17 beta (E2) and prostaglandin F2 alpha metabolite (PG-metabolite) analysis. A rank-order test and an ACTH test were performed on day 4 and day 5 of grouping respectively. The sows were slaughtered on day 17 +/- 1 of pregnancy and embryos recovered. Aggression accompanied by elevations (p < 0.05) in cortisol concentrations occurred in all grouped sows on the first day of grouping. The cortisol increase was greater (p < 0.01) in the subordinate than in the other ranked sows. Cortisol concentrations and the level of aggression decreased on subsequent days during grouping, but the cortisol levels were still higher than on the pre-grouping day except for the intermediate ranked sows. Cortisol concentrations after the ACTH test were similar in the grouped as well as the control sows. The dominance hierarchy was confirmed during the rank order test. Concentrations of P4, E2, PG-metabolite and CBG were similar between the group-housed sows and with the controls. Mean embryonic recovery was 66.8% +/- 11.5%, 71.3% +/- 6.0%, 70.0% +/- 16.0%, and 69.9% +/- 5.8% for the dominant, intermediate, subordinate, and control sows respectively. Hence, group housing during early pregnancy did not influence reproductive hormones or embryonic survival.

Animal Husbandry↗

Hormone profiles around weaning in cyclic and anoestrous sows.

Peripheral plasma patterns of LH, cortisol, corticosteroid-binding globulin (CBG) and beta-endorphin were studied around weaning in sows that resumed cyclicity and those that remained anoestrus after weaning. Average LH concentration in both groups of sows, and basal LH concentration, LH pulses/6 h and the sum of LH pulses and peaks/6 h in the cyclic sows, increased from the day before weaning to significantly higher (P < 0.05) levels on the days after weaning. Overall, average and basal LH concentrations were higher (P < 0.05) in the sows that resumed cyclicity than in those that remained anoestrus. Cortisol and beta-endorphin concentrations were high before weaning and on the day of weaning in both groups of sows. Cortisol in the cyclic sows, and beta-endorphin in both groups of sows, decreased (P < 0.05) after weaning. CBG levels were unchanged until the second day after weaning when there was an increase (P < 0.05) in both groups of sows. Before and even after weaning cortisol, CBG and beta-endorphin levels tended to be higher in the sows that remained anoestrus compared with those that resumed cyclicity. Findings in the present study show higher levels of cortisol, CBG and beta-endorphin before weaning that persisted even after weaning, and lower LH concentrations around weaning in sows that failed compared with those that resumed oestrous activity.

Animals↗

Clinical changes in ovariectomized ewes exposed to phytoestrogens and 17 beta-estradiol implants.

Eight Swedish Finewool Landrace ewes, ovariectomized 5 months earlier and kept on nonestrogenic hay, were each fed 3.5 kg red clover silage, corresponding to 6.1 g phytoestrogens (of which 3.5 g was formononetin) per day, for 14 days in November (short days). In January (short days), two groups (3 each) of these ewes received one or two 17 beta-estradiol sc implants. In May (long days), one of two new groups (4 each) of these ewes was reexposed to phytoestrogens for another 14 days while the other served as a control. Physical examination of ewes for changes in reproductive organs was carried out two or three times per week during each feeding/treatment, and continued until observed changes disappeared. Clinically significant changes occurred in the reproductive organs of ewes fed red clover. Vulva color changed from pale to pink and red, and there were enlargements of the vulva, uterus, and udder. In addition, teat length and circumference increased, and secretion of milky fluid began. These changes were similar, but more pronounced during treatment with 17 beta-estradiol, particularly teat circumference. The changes in vulva were more dramatic in May than in November and resembled those observed in ewes treated with estradiol. Our data show that a daily intake of 3.5 g formononetin for 14 days caused the increase of teat size and changes in the color of the vulva and in uterus weight in ovariectomized ewes.

Animals↗

Leucine enkephalin level in rat hypothalamus, striatum, hippocampus and adrenal glands in experimental rat uremia.

The aim of the study was to analyze the effect of experimental uremia elicited in Wistar rats by 5/6 kidney resection on the leu-enkephalin level in hypothalamus, striatum, hippocampus and adrenal glands. We found, that in uremic rats leu-enkephalin levels decreased in striatum and in adrenal glands. The level of leu-enkephalin in adrenal glands was directly related to plasma creatinine. The weight of uremic rats was significantly lower than that of control rats.

Adrenal Glands↗

Antitumor activity of bestatin and thiorphan in mice.

We have investigated the effect of bestatin and thiorphan on growth of murine transplantable tumors, survival time, activity of natural killer (NK) cells and macrophages in mice. The injections of thiorphan at the does of 0.5 or 5 micrograms per mouse retarded tumor growth and prolonged survival period in B16 melanoma bearing animals. Pretreatment with naloxone (an unspecific antagonist of opioid receptors) blocked the tumor growth inhibition induced by the treatment with bestatin and thiorphan what could suggest a contribution of endogenous enkephalin in this antitumor effect. The percentage of mice bearing B16 melanoma tumor in the group treated with thiorphan at doses of 0.5, 5 or 50 micrograms per mouse was lower in comparison with control animals in a dose-dependent manner. The treatment with thiorphan at concentrations of 0.4-1.6 mg/ml inhibited growth of cultured in vitro B16 melanoma cell in comparison with control culture. Thiorphan added to the medium at concentration of 0.5 microgram/ml or administered 4 times at the dose of 0.5 microgram/mouse augmented NK lymphocyte activity.

Animals↗

Effects of oestrogenic silage on some clinical and endocrinological parameters in ovariectomized heifers.

The influence of phytoestrogens was studied in 3 ovariectomized Swedish Friesian heifers fed 20 kg of 100% red clover silage per heifer/day for 14 days. Behaviour, reproductive organs and pituitary response to exogenous gonadotropin-releasing hormone (GnRH) injections were monitored. Clinical effects like oedema and mucous discharge in the vulva, presence of milky fluid in the mammae and increases in teat size and the cross-sectional distance of the uterus were observed in heifers fed red clover silage. Fluid accumulation in the uterus, visualized by means of ultrasonography, had still not disappeared 30 days after the red clover silage had been completely withdrawn. Red clover silage appeared to reduce the magnitude and duration of the pituitary response to GnRH injections.

Animals↗

Patterns of release of oxytocin, prolactin, insulin and LH in lactating sows, studied using continuous blood collection technique.

To describe the patterns of release of oxytocin, prolactin, insulin and LH in relation to suckling and to investigate relationships between them, blood was collected continuously from four sows at a rate of 1 ml per min for 12 h (0900-2100 h) on day 10 (D10) and day 20 (D20) of lactation. The 12-h period was divided into four smaller periods: P1 (0900-1200 h), P2 (1200-1500 h), P3 (1500-1800 h) and P4 (1800-2100 h). The number of nursings occurring during a 12-h period tended to decrease between D10 (17.3 +/- 0.3) and D20 (16.0 +/- 0.3). About 40-50% of all sucklings induced a significant rise in plasma oxytocin, while prolactin gradually increased following each suckling. Decrease in the levels of oxytocin (14.1 +/- 0.4 vs 7.1 +/- 0.4 pmol/l, P < 0.001), prolactin (12.9 +/- 0.3 vs 7.9 +/- 0.1 micrograms/l, P < 0.001) and insulin (24.8 +/- 1.7 vs 14.4 +/- 1.7 mU/l, P < 0.001) were observed between D10 and D20. Average and basal levels of LH and the number of LH pulses increased (P < 0.01) between D10 and D20. A negative correlation between number of sucklings and number of LH pulses was demonstrated on D20 (r = -0.59, P = 0.07). There was a positive correlation between levels of LH and oxytocin on D10 (r = 0.54, P = 0.001) and between prolactin and insulin levels on D20 (r = 0.34, P = 0.05).

Animals↗

Radioimmunoassay of bovine, ovine and porcine luteinizing hormone with a monoclonal antibody and a human tracer.

A radioimmunoassay for bovine (bLH), ovine (oLH) and porcine (pLH) luteinizing hormone was developed using a human 125ILH tracer from a commercial kit and a monoclonal antibody (518B7) specific for LH but with low species specificity. Standard curves demonstrated similar binding kinetics when bLH, oLH and pLH were incubated with tracer and antibody for 2 h at room temperature. A 30-min delay in the addition of the tracer gave sufficient sensitivity when analysing pLH. Separation of antibody-bound LH from free hormone was achieved by using second antibody-coated micro Sepharose beads. The assay was validated and the performance compared with that of an RIA currently in use for determination of bLH and oLH (coefficient of correlation: 0.99 and 0.98). Regardless of the standards used, intra-assay coefficients of variation were < 10% for LH concentrations exceeding 1 microgram/L. The inter-assay coefficients of variation were < 15%. The assay was used for clinical evaluation demonstrating the pre-ovulatory LH surge in two cyclic cows, LH pulsatility in an oophorectomized ewe and LH response to GnRH injection in a boar.

Animals↗

Effects on testosterone, LH and cortisol concentrations, and on testicular ultrasonographic appearance of induced testicular degeneration in bulls.

It is well known that heat stress has a detrimental effect on testicular functions. In addition to the alteration of semen quality and testicular damage, reproductive hormone secretion can be altered. The objective of this study was to describe changes in plasma concentrations of testosterone, LH and cortisol, as well as in testicular ultrasonographic appearance after induced testicular degeneration. Four Swedish Red and White bulls, aged 3 years, were used. They were fed according to Swedish standards. The scrotum was covered with an insulation device during 96 h. Semen was collected weekly 3 times before and up to 4 months after insulation. Testicular ultrasonography and clinical genital examination were performed with the same intervals. Heparinized blood samples were taken from the jugular vein at 2 h interval during 24 h every 2 weeks during the study. Blood samples were tested for the content of testosterone, LH and cortisol. Data were analysed, using one way analysis of variance of seminal data, clinical examination data as well as 24 h hormonal output data as percentage of mean individual pretreatment values. The use of a 5 MHz B-mode ultrasound unit did not contribute with an objective estimation of the degree of testicular degeneration. In 3 of the bulls testosterone levels had a tendency to decrease and LH to increase during the time of severe degeneration, whereas an opposite trend was seen during the regenerative phase, changes becoming significant 15 weeks after scrotal insulation. Variation between animals was big. Cortisol levels had a decreasing trend, changes being significant only in individual bulls at 10 and 15 weeks after scrotal insulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Hormonal interrelationships in postpartum suckled dairy cows.

Three cross-bred cows calved in March and April and were followed until day 62 after parturition. Each animal was suckled by 2 calves ad libitum. All calves were removed from the cows on day 55 after parturition. Blood was collected 3 times per day from the jugular vein by venipuncture. On 4 occasions after parturition--i.e. days 7-8, 21-22, 35-36 and 49-50, the cows were bled through a jugular venous catheter every 30 min during the 24 h. The plasma samples were analyzed for the content of 15-keto-13,14-dihydro-PGF2 alpha (main PGF2 alpha metabolite), LH, prolactin, cortisol and progesterone by radioimmunoassay methods. The concentration of PGF2 alpha increased from 280 to 730 pmol/l within the last 4 days before parturition. The highest geometric mean was 3106 pmol/l on the day of parturition. Thereafter a steady decrease of PGF2 alpha metabolite concentration was seen until day 21 when it reached plateau at 148 pmol/l. In all cows plasma LH concentrations increased significantly (P < 0.05) from about 1.6 micrograms/l on days 7-8 to 2.4 micrograms/l on days 21-22 post partum. The frequency of LH pulses showed no tendency to increase as the postpartum period progressed and averaged 6.5 pulses/24 h. Mean plasma LH concentrations increased from 2.1 micrograms/l 2 days before weaning to 3.2 micrograms/l 2 days after weaning (P < 0.05). LH peaks occurred less frequently in association with prolactin and cortisol peaks than in their absence. A partial positive correlation between PGF2 alpha metabolite and cortisol (r = 0.30) was found on days 7-8 post partum. Correlation between prolactin and cortisol on days 7-8 and 21-22 post partum was also positive (r = 0.20 and r = 0.27, respectively). There was a negative correlation between LH and cortisol on days 7-8 (r = -0.27) and days 49-50 (r = -0.21) post partum. The first and short progesterone increase observed after weaning was terminated in conjunction with PGF2 alpha metabolite peaks.

Animals↗

Quantitative relationships between suckling-induced teat stimulation and the release of prolactin, gastrin, somatostatin, insulin, glucagon and vasoactive intestinal polypeptide in sows.

The pituitary hormones prolactin and oxytocin play important roles in the production and ejection of milk. In addition, some gastrointestinal peptides are released in response to suckling. During suckling, the piglets massage the udder of the sow both before and after let-down and the duration of suckling is correlated to the amount of milk produced by the sow. The aim of this study was to investigate whether there is a quantitative relation between the release of prolactin, gastrin, somatostatin, insulin, glucagon and vasoactive intestinal polypeptide (VIP) and the amount of stimulation of the sow's teats by the piglets. Repeated blood samples were drawn from three Swedish Landrace sows during three consecutive nursings by each sow on days 1, 3, 7 and 14 after parturition. The duration of massage by the piglets was noted, as was the number of piglets massaging. Hormone levels were quantified by radioimmunoassay. The release of prolactin, somatostatin, insulin, glucagon and VIP but not of gastrin were found to be significantly related to the amount of teat massage performed by the piglets during the first 2 weeks of lactation. The release was related to the duration of piglet massage or to the combined effect of duration and the number of piglets massaging but not to the number of piglets massaging per se. The basal level of prolactin was found to decrease during this time.

Animals↗

A rapid radioimmunoassay for determining plasma concentrations of LH in dogs.

A heterologous dog LH radioimmunoassay was modified to provide accurate results for LH concentrations in blood plasma of dogs within 3-4 h. This assay utilizes radioiodinated ovine LH (LER-1056-C2), antiserum against ovine LH (GDN-15) at a final dilution of 1:48,000 and dog LH (LER-1685-1) as standard. A 60-min incubation, including a 30-min delay in the addition of tracer, was carried out at 37 degrees C. The free and antibody-bound hormone were separated by addition of a Micro Sepharose bead suspension containing anti-gamma-globulin, followed by incubation at room temperature for 30 min. The minimum detectable concentration in this assay, calculated from the precision profile, was 1.5 micrograms/l. The amount of dog LH needed to cause 50% reduction of the initial binding was 1.57 +/- 0.13 ng/tube (15.7 micrograms/l for 100-microliters samples). Daily blood samples were collected in heparinized tubes from the cephalic vein of 5 pointer and 7 beagle bitches from the onset of pro-oestrus until 3-4 days after either the last mating or artificial insemination with frozen semen or until metoestrus. Samples were assayed for LH content by the short and normal incubations as well as for progesterone and oestradiol-17 beta content. In all bitches plasma concentrations of progesterone increased rapidly within 1 week after the LH peak which indicates that they had ovulated. Comparison of the short (1.5 h) with the normal (24 h) incubation system resulted in a regression equation: y = 1.0 + 0.7 x (r = 0.95, n = 153 samples).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Levels of oestrone sulphate during pregnancy in different breeds of cows and its possible association with retained foetal membranes.

The levels of oestrone sulphate in plasma of pregnant cows was followed from 30 days of pregnancy until parturition. The Swedish Jersey Breed (SJB) showed significantly lower levels of oestrone sulphate between 101 and 200 days of pregnancy than either the Swedish Red and White (SRB) or the Swedish Lowland Breed (SLB). No significant difference was noted between SRB and SLB. On days 141-160 of gestation the oestrone sulphate values were still below the 10 nmol/l level for the SJB while they were above this level for the SRB and the SLB, and the difference was significant. In the SJB, levels above 10 nmol/l were reached on days 161-180 of gestation. In the second part of this study the levels of oestrone sulphate were measured around parturition in SRB cows. At parturition, the levels of oestrone sulphate rose to peak values of 79.9 +/- 5.2 nmol/l and then decreased to 6.6 +/- 0.5 nmol/l on the day after calving. In one cow peak values of 66.0 nmol/l were reached 2 days prior to parturition, and subsequently dropped to 7.0 nmol/l at parturition. This cow had retained foetal membranes. A possible relationship between low oestrone sulphate levels prior to parturition and retained foetal membranes is discussed.

Animals↗

Effect of fractionated weaning on hormonal patterns and weaning to oestrus interval in primiparous sows.

The effect of weaning the 4-5 heaviest piglets in the litter on day 33 of lactation and the remainder 2 days later (fractionated weaning) on plasma levels of prolactin, cortisol, oestradiol-17 beta (E2), progesterone (P4) and LH, as well as on the weaning to oestrus interval in primiparous sows was studied. Twelve crossbred sows were grouped into 6 pairs according to farrowing date and litter size. The litter of 1 sow in each pair (F) was weaned in 2 stages, and the other conventionally weaned at 35 days (C). Blood samples were collected via a permanent jugular vein catheter every 3 h from 9 a m to 9 p m daily throughout the experimental period, and intensively at 15 min intervals for 12 h on the day of first and final weaning and for 6 h on the day after each weaning. All sows were slaughtered following their first post-weaning oestrus and the reproductive organs were macroscopically examined. Lactational oestrus was not observed in any of the sows. Sows from 5 out of 6 pairs showed oestrus within 8 days of weaning and post-mortem examination showed normal ovulation. There was a tendency for the F sows to have a shorter weaning to oestrus interval, as compared with the C sows (5 of 6 pairs, 4.8 days v 5.6 days). The plasma levels of prolactin around weaning were not significantly different between the 2 groups. Within 6 h after final weaning, the prolactin concentrations decreased gradually from 7.6 and 8.7 to 1.6 and 1.7 microgram/l in the control and treatment groups, respectively. The plasma levels of cortisol, showing a diurnal rhythm (with the lowest level at 6 and/or 9 p m), did on no occasion differ between the 2 groups. On the day of final weaning, no diurnal rhythm was observed, with cortisol remaining high at 6 and 9 p m. The plasma levels of E2 and P4 were low until final weaning in both groups. After final weaning the E2 levels rose faster in the F sows than in the C sows, to 44.3 and 34.8 pmol/l, respectively, on day 2 (p less than 0.01). No significant differences in levels of plasma LH and the number of LH pulses were observed between the groups. After final weaning the average and base levels of LH and the number of LH pulse(s) increased significantly.

Animals↗