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1.
Incidences and morphological features of thyroid proliferative lesions induced by carcinogens in Wistar Hannover GALAS rats (GALAS rats) showing normal growth with or without thyroid dysplasia were examined. All thyroid tissue samples were obtained from our recently conducted study using male GALAS rats treated with 5 carcinogens according to the medium-term multiorgan carcinogenicity bioassay protocol (called DMBDD treatment). In the DMBDD-treated rats, thyroid dysplasia was found in 9 out of 114 rats. Follicular cell adenomas were found in 5 out of 9 rats with thyroid dysplasia and in 7 out of 105 rats without thyroid dysplasia. The incidence of adenoma was significantly increased in rats with thyroid dysplasia (55.6%) compared with that in rats without thyroid dysplasia (6.7%). Adenomas in rats with thyroid dysplasia were observed as single or multiple nodules, well demarcated and composed of variously sized vacuolated cells or unvacuolated cells. These histopathological features and staining profiles of luminal colloid for PAS and thyroglobulin, together with PCNA-positive cells, were fundamentally similar to those of rats without thyroid dysplasia. On the other hand, the luminal colloid in adenomas of rats with thyroid dysplasia had a tendency to be poorly stained for T(4) compared with that of rats without thyroid dysplasia. From these findings, it appears that dysplastic thyroids of rats showing normal growth are more sensitive to carcinogens than normal thyroids. In addition, the morphological features of carcinogen-induced thyroid proliferative lesions in GALAS rats with thyroid dysplasia were fundamentally similar to those of rats without thyroid dysplasia, except for the vacuoles and T(4) staining profile.  相似文献   

2.
Diffuse hyperplastic goiter was diagnosed by histopathology in 11 perinatal bottlenose dolphins (Tursiops truncatus) that died at four separate zoos and aquaria. Thyroid morphology of these animals was compared with the histologically normal thyroids of two stranded wild bottlenose dolphin calves, a neonate and a 2-mo-old calf. Histologic changes included reduced follicular luminal diameter, markedly reduced or absent luminal colloid, hypertrophy of follicular epithelium, and follicular dysplasia. The etiology of the thyroid gland lesion was not identified. Cause of death was not determined for most of these animals, but they were presumed to have died from metabolic derangements associated with the thyroid lesion, drowning, or dystocia.  相似文献   

3.
The histological features of a follicular dysplasia with pigmentary changes is reported in two adult cows, one a black Brangus-cross and the other a black Angus. Adult onset of diffuse alopecia was present in both cows. Skin biopsies exhibited follicular distortion and atrophy, with melanin clumping in follicular epithelium, hair bulb matrix cells, hair shafts, and infundibular keratin. Both animals were clinically normal apart from the alopecia. This report confirms and expands on the infrequently reported syndrome of follicular dysplasia in cattle.  相似文献   

4.
Ractopamine, a synthetic β(2)-adrenoceptor agonist, is widely used as a feed additive in the United States to promote a reduction in body fat and enhance muscle growth in cattle, pigs, and turkeys. It has the potential for illegal use in show and racing animals because it may affect performance via its β-adrenergic agonist properties or anabolic activities. Nine greyhounds were orally administered 1 mg/kg of ractopamine to investigate the ability to detect the drug in urine. Postdosing, 7 of 9 dogs developed cardiac arrhythmias and had elevated troponin levels indicating myocardial damage. One dog necropsied 4 days postdosing had massive myocardial necrosis, mild to focally moderate skeletal muscle necrosis, and widespread segmental arterial mediolysis. A second dog necropsied 17 days postdosing had mild myocardial necrosis and fibrosis. Scattered arteries exhibited segmental medial and perimedial fibromuscular dysplasia. This is the first reported case of arterial, cardiac, and skeletal muscle damage associated with ractopamine.  相似文献   

5.
The percentage, distribution, shape, intensity of staining and morphometrical parameters of the pituitary TSH immunoreactive cells and the histological features of the thyroid glands, were compared between adult rats with intact adrenals, without adrenals and biadrenalectomized animals with neonatal adrenal grafts. After the removal of the adrenal glands, TSH immunoreactive cells increased in percentage and exhibited a higher complexity of the cellular outline, than that of the intact animals. The nuclear, cytoplasmic and cell areas were significantly increased. However the bigger enhancement of the cytoplasmic area relative to the nuclear area, produced a decrease in the nuclear/cell area ratio. The thyroid glands showed some histological evidences of activation. After the transplantation of neonatal adrenal glands to adult rats, several adrenocortical nodules were present in the lumen of the small bowel segment. These adrenal masses induced a great decrease in the TSH cell area, which coupled with a smaller but significant variation of the nuclear area, led to an increase in the nuclear/cell area ratio relative to that observed in adrenalectomized animals. In addition, the distribution, shape and intensity of the immunoreactive material was similar to that observed in intact animals. In this experimental group, thyroid histology was observed to be similar to that of the intact animals.  相似文献   

6.
The objective was to study control of mature size by characterizing metacarpal growth plate closure in relation to relevant bone growth-regulating hormones in two breeds exhibiting distinct differences in mature frame size. Thirty-four Suffolk and 34 Dorset ram lambs were slaughtered in pairs within breed at birth, weaning and monthly intervals until 420 d and then bimonthly to 600 d. Plasma growth hormone was depressed to undetectable levels due to the high-energy, ad libitum-fed diet. Plasma insulin-like growth factor-I (IGF-I) rose over the growth period from 116 ng/ml (newborn Suffolk) to a high of 451 ng/ml (420-d Dorset); it appeared to peak at approximately 400 d and then declined to a stable level. Dorsets consistently exhibited higher IGF-I levels. The thyroid hormones exhibited no apparent age association. An age-associated rise was detected for testosterone, but not for estradiol. Mature metacarpal lengths were estimated to be 147.2 and 127.4 mm for Suffolks and Dorsets, respectively. Ninety-five percent of mature length was attained in Suffolks by 226 d and in Dorsets by 165 d. Growth plates, however, did not begin to appear closed until 390 d and closure was not complete in all animals until 480 d, suggesting that metacarpal growth rate was dissociated temporally from growth plate closure. Although growth plate closure likely is controlled by the endocrine system, there were no apparent relationships between circulating hormones and growth plate width, age at closure or zonal divisions within the growth plate, suggesting that the growth plate experiences a very different hormonal environment than what can be measured in the circulating blood.  相似文献   

7.
A two part survey was carried out in Irish Thoroughbred horses in 1988 and 1989 to establish the incidence and prevalence of developmental skeletal problems, particularly possible manifestations of developmental orthopaedic disease (DOD). Survey One was a retrospective study based on a questionnaire involving the foal crops of 46 stud farms for 3 successive seasons; the 1711 animals initially documented represented 10.46% of Irish foal registrations. The second survey involved repeated monitoring of the 1988 foal crop from birth to 18 months of age on 17 stud farms. The 248 foals initially examined represented 4.24% of foal registrations. Treatment for DOD was deemed necessary for 11.3% of the animals in Survey One. Angular limb deformities and physeal dysplasia ("epiphysitis") together constituted 72.9% of the cases treated. The peak incidence of DOD problems occurred between weaning and the end of December. More than half the animals treated (53.9%) recovered completely, ie achieved expected sale value as yearlings, 27.5% of those treated showed incomplete recovery and mild to moderate loss of sale value and the remaining 18.7% were killed or lost much of their sale value. In the second survey, while 67% of animals exhibited some form of DOD, the incidence and severity of problems treated were not significantly different from those of farms in Survey One. Again, physeal dysplasia and angular limb deformity were the predominant clinical conditions and their severity was greatest during the early winter. During the suckling phase colts had a significantly greater incidence of DOD. At all other stages the incidence and severity of DOD was similar in both sexes.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

8.
This study was designed to investigate the histologic changes in goitrogen-induced thyroid growth of the rat. The animals were orally treated by 1% potassium perchlorate except the controls and were sacrificed in intervals ranging from 1 to 12 months. The thyroid weight increased progressively along the treatment and after 2 months showed a diffuse homogenous hypertrophy and hyperplasia of follicular cells, decreased amount of colloid and increased vascularity. After sixth month of treatment true nodules appeared with complex morphology.  相似文献   

9.
Since insufficient iodine intake is widespread among the German population, farm animals should if possible receive iodine above requirement, thus concentrating the trace element in milk, eggs and possibly meat. Experiments with a total of 29 fattening pigs with grain soy-bean meal diets without iodine supplementation or with increasing supplements up to 1000 micrograms iodine/kg diet did not show any effect on growth intensity (gain) and feed efficiency. At and above 125 micrograms supplementary iodine/kg diet the thyroid was not or only little hypertrophied and iodine incorporation into thyroglobulin sufficed to sustain serum T4 concentration. The glucosinolates of rape feeds increase iodine requirement. In an experiment with a total of 36 fattening pigs the thyroid iodine depot was decreased due to rapeseed meal feeding, this in agreement with antithyroid drugs which had been also tested. A thyroid with emptied iodine depot is hardly able to synthesize and release hormone, the serum thyroxine concentration showed a drastic decrease. More iodine may compensate for effects of glucosinolates, however, only with not too much of these compounds in the feed. Excessive iodine dosages (10 mg/kg diet) were compared with supplements in the range of recommendations (100 and 1000 micrograms/kg diet) with a total of 120 pigs in three groups of 40 animals each. The dosage of 10 mg iodine/kg diet decreased serum T3 concentration. The enlarged thyroid with double weight had a very high iodine concentration. In comparison with physiological application (100 or 1000 micrograms iodine/kg diet) the thyroid deposited only little iodine in the group with the excessive iodine intake related to consumed iodine quantity. In case of sufficient and excessive iodine supply--industry of compounds feed applies up to 2.5 mg supplementary iodine/kg diet--T4 and iodine of serum but also thyroid weight cannot serve as markers. This range of usual iodine supply is better characterized by the iodine depot of the thyroid. As a rule, thyroid weight increase indicates glucosinolate effects, generally those of dietary antithyroid compounds, more seldom it shows extreme and longterm iodine undersupply or iodine excess.  相似文献   

10.
Massimo  Vignoli  DMV  SRV  Giuseppe  Sarli  DMV  Federica  Rossi  DMV  SRV  Rossella  Terragni  DMV  SPCAA  Luigi  Pozzi  DMV 《Veterinary radiology & ultrasound》2002,43(6):528-533
A Boxer puppy had an unusual dysplastic lesion of the distal epiphysis of the left femur. Biopsy and CT examination were performed. A diagnosis of dysplasia epiphysealis hemimelica (DEH) was made. To the investigators knowledge, this condition has not been described before in animals. DEH is a growth disorder involving preferentially the medial compartment of the lower limbs, and it is associated with epiphyseal hypertrophy and delayed mineralization.  相似文献   

11.
Observations of feed intake, digestibility, production and selected blood values were made during the winter housing period on 10 lactating dairy cows, naturally infected with gastrointestinal roundworms, which were either left untreated or dosed on two occasions with thiabendazole in-feed. While treatment had no significant effect on appetite or production, there was a 9.8 per cent improvement in cellulose digestibility (P less than 0.05). An increase in circulating cholesterol in treated cows was associated with the improved utilisation of cellulose. It is considered unlikely that thiabendazole's primary anthelmintic activity was responsible for this effect. Treated cattle also exhibited a significant improvement in thyroid function during the course of the study compared with control animals. This might account for the increase in milk production reported in several trials following anthelmintic treatment of dairy cows.  相似文献   

12.
Hair loss in Chesapeake Bay retrievers has been increasingly recognized by breeders in recent years. Anecdotal reports suggest an endocrine disorder or follicular dysplasia as the underlying cause, but no scientific study has been done to investigate the underlying problem. A prospective study was carried out in collaboration with the American Chesapeake Club. Affected dogs were recruited into the study. Routine dermatological and hormonal (blood and urine) tests, and skin biopsies were performed. Ten dogs (age 1.5–10 years), seven females (two spayed) and three males (two neutered), were included in the study. All dogs had mild or severe hair loss affecting the lateral ventral chest, flanks, rump and thighs. Affected dogs were clinically healthy. Hormonal tests revealed normal thyroid hormone panels, insulin-like growth factor-1 levels, and urinary cortisol:creatinine ratios in samples collected for ten consecutive days. In six of 10 dogs, an adrenal hormone panel showed slight or moderate increased values pre- and/or post-ACTH stimulation of cortisol (three of six), 17-hydroxyprogesterone (five of six), androstenedione (three of six), estradiol (two of six) and progesterone (six of six). The major histopathologic changes resembled canine flank alopecia and follicular dysplasia with pronounced infundibular hyperkeratosis, mild follicular atrophy, and occasional melanin clumping with dystrophic hair shafts. Chesapeake Bay retrievers suffer from a type of hair loss that is likely related to an abnormal production of adrenal sex hormone. Further studies are currently underway to determine if there is a heritable basis for this disease and to evaluate therapeutic options.
Funding: University of Pennsylvania.  相似文献   

13.
In the experiment, 2 x 12 growing pigs received 19 or 6.7 mmol glucosinolates + aglucones/kg feed via conventional rapeseed meal (RSM) or RSM of a newly bred variety. These pigs and 24 littermates pair fed with a soya bean meal (SBM) diet were subdivided in groups of 4 animals each. Their diet contained either no supplementary iodine or an iodine supplementation of up to 1 mg/kg feed. In the RSM and SBM groups the lack of additional iodine lowered the serum T4 and T3 content below the detection limit and caused goitre with about 1 mg iodine in the total thyroid. The SBM diet with 0.0625 mg supplementary iodine/kg increased the serum T4 level and reversed the thyroid enlargement but not that of epithelial cells. The hypothyroidism (goitre and serum T4 level approximately 10 nmol/l) still existed in the case of this iodine dosage together with the RSM of the newly bred variety. A serum T4 level comparable to that of the animals fed SBM was only reached by supplementing the low glucosinolate diet with 0.25 mg iodine/kg feed. The iodine content of the thyroid, however, was reduced by 50 per cent. Though thyroid and epithelial cells were enlarged, this enlargement was not so obvious as in animals exposed to higher glucosinolate level. In spite of 1 mg supplementary iodine/kg feed, the feeding of the conventional RSM resulted in a lower serum T4 level a reduced thyroid iodine content and the enlargement of thyroid and that of epithelial cells. Compared to the high glucosinolate RSM, a significantly lower antithyroid effect of the low glucosinolate RSM was found in pigs with iodine supply. The degree of thyroid enlargement and the serum T4 level were the criteria.  相似文献   

14.
Congenital hypothyroidism with goiter was observed to segregate as a simple autosomal recessive trait in Toy Fox Terriers (TFTs). Neonatal affected pups exhibited inactivity, abnormal hair coat, stenotic ear canals, and delayed eye opening. Palpable ventrolateral cervical swellings were evident by 1 week of age. Serum thyroid hormone and thyroid-stimulating hormone concentrations were low and high, respectively. Histologic examination of the cervical masses disclosed cuboidal to columnar follicular epithelial cell hyperplasia with widely varying follicular size, shape, and amount of colloid. Oral thyroid hormone replacement therapy restored near-normal growth and development. At 8 weeks of age, radioiodine uptake and perchlorate discharge testing indicated an iodine organification defect. Biochemical analysis of thyroid tissue from affected dogs demonstrated enzymatic iodine oxidation deficiency and lack of sodium dodecyl sulfate-resistant thyroglobulin dimers, suggesting thyroid peroxidase deficiency. A nonsense mutation in the thyroid peroxidase gene of affected dogs was discovered and demonstrated to segregate with the disease. A DNA-based carrier test was developed and currently is used by TFT breeders to prevent this disorder.  相似文献   

15.
Effects of thyroid status on renal calcium and magnesium handling.   总被引：1，自引：0，他引：1       下载免费PDF全文
Renal calcium and magnesium handling was studied in rats with chronic thyroid hormone deficiency or excess, hyperthyroidism. Mean kidney weight of the thyroid deficient rats was 42% of age matched, euthyroid and hyperthyroid animals and glomerular filtration rate was 71% of normal. Fractional sodium excretion was consistently elevated in thyroid deficient rats (0.26%) as compared to euthyroid (0.07%) and hyperthyroid animals (0.07%). Urinary calcium excretion (0.39%) was also elevated and parallel to sodium excretion in thyroid deficiency. Despite this renal leak of sodium and calcium, thyroid deficient animals conserved magnesium much more efficiently than either euthyroid or hyperthyroid rats (5.7% vs 17.4% respectively). Plasma magnesium concentration was elevated by acute MgCl2 infusions to determine the reabsorptive capacity of magnesium. Thyroid deficient rats reabsorbed 15-30% more of the filtered magnesium at any given plasma concentration. Although these effects on electrolyte reabsorption are modest compared to the hemodynamic alterations, the data suggest that thyroid hormone has a direct effect on the tubule which if chronically absent results in subtle sodium and calcium wasting and renal retention of magnesium. Administration of thyroid hormone to euthyroid or thyroid deficient rats twenty-four hours prior to experimentation had no effect on calcium and magnesium handling.  相似文献   

16.
One hundred sixty crossbred steers were used to compare the effects of metabolizable protein and energy restrictions on subsequent compensatory growth. Diets were formulated to impose severe or mild growth restrictions for periods of 77 to 154 d. Steers were realimented on a high-concentrate diet and fed to achieve approximately 1 cm s.c. fat thickness. Finishing performance and carcass characteristics were evaluated relative to unrestricted control animals. All restricted animals, with the exception of those on the mild, brief energy restriction, exhibited compensatory growth relative to controls. A single direct comparison of energy and protein restriction treatments indicated that finishing performance during realimentation was similar for these two groups. Evaluation of the relative effects of protein and energy restriction by multiple linear regression indicated that compensatory growth was influenced by differences in duration or severity of nutrient deprivation to a greater extent for energy-restricted than for protein-restricted steers. Linear contrasts and regression estimates indicated that compensatory growth was influenced more by differences in severity of restriction than by duration of the restriction period.  相似文献   

17.
One hundred and five Labrador dogs were randomly divided into two groups to determine the number of animals that develop elbow dysplasia when treated with an oral supplement compared to untreated ones. Efficacy of the oral treatment was also evaluated once illness was diagnosed. The supplement (Hyaloral) contained hyaluronic acid, hydrolysed collagen, glucosamine, chondroitin sulphate, and gamma oryzanol. Clinical evaluation of the elbow joints was completed at months 3, 6, 12, and 20 by orthopaedic evaluations, radiography, serologic and blood analysis, and veterinarian evaluation of dysplasia symptoms. All side effects were recorded. In the control group, 33.3% of the dogs developed radiographic evidence of elbow dysplasia compared to 18.5% in the treated group. Symptoms of dysplasia at 12 months differed between the treated (12.5%) and control (61.5%) animals, and were significantly different at 20 months (p < 0.05). Differences in lameness along with movement and swelling of the elbows between groups were observed after 12 months. The treated group had improved significantly by the last visit (p < 0.05). No adverse side effects were reported. In conclusion, oral treatment with Hyaloral may have a potential cumulative action that provides protection against dysplasia and significantly improves symptoms of elbow dysplasia.  相似文献   

18.
Hair loss in Chesapeake Bay retrievers has been increasingly recognized by breeders in recent years. Anecdotal reports suggest an endocrine disorder or follicular dysplasia as the underlying cause, but no scientific study has been done to investigate the underlying problem. A prospective study was carried out in collaboration with the American Chesapeake Club. Affected dogs were recruited into the study. Routine dermatological and hormonal (blood and urine) tests, and skin biopsies were performed. Ten dogs (age 1.5–10 years), seven females (two spayed) and three males (two neutered), were included in the study. All dogs had mild or severe hair loss affecting the lateral ventral chest, flanks, rump and thighs. Affected dogs were clinically healthy. Hormonal tests revealed normal thyroid hormone panels, insulin‐like growth factor‐1 levels, and urinary cortisol:creatinine ratios in samples collected for ten consecutive days. In six of 10 dogs, an adrenal hormone panel showed slight or moderate increased values pre‐ and/or post‐ACTH stimulation of cortisol (three of six), 17‐hydroxyprogesterone (five of six), androstenedione (three of six), estradiol (two of six) and progesterone (six of six). The major histopathologic changes resembled canine flank alopecia and follicular dysplasia with pronounced infundibular hyperkeratosis, mild follicular atrophy, and occasional melanin clumping with dystrophic hair shafts. Chesapeake Bay retrievers suffer from a type of hair loss that is likely related to an abnormal production of adrenal sex hormone. Further studies are currently underway to determine if there is a heritable basis for this disease and to evaluate therapeutic options. Funding: University of Pennsylvania.  相似文献   

19.
The normal radiographic anatomy of the equine larynx was determine by use of xeroradiography and dissection. The body and laminae of the thyroid cartilage, the muscular process of the arytenoid cartilages, and the dorsal lamina and arch of the cricoid cartilage had radiographic evidence of mineralization (calcification) and/or ossification in clinically normal horses. There was a significant (P less than 0.01) increase in the degree of mineralization of the thyroid and arytenoid cartilages with advancing age. Horses with diagnosis of arytenoid chondrosis (arytenoid chondral dysplasia, arytenoid chondropathy) by use of endoscopy had radiographic changes that included: enlargement with increased density of the arytenoid cartilage region, abnormal patterns of mineralization (dystrophic mineralization or osseous metaplasia), abnormal contour of the corniculate process(es) and laryngeal masses, sometimes obliterating part or all of the lateral laryngeal ventricles.  相似文献   

20.
Spontaneous sleep movement disorders in 5 cats and 3 dogs were studied. Objective abnormalities during sleep were confirmed by electrographic or behavioral monitoring techniques in all animals. The cause of the disorder was CNS disease in 3 animals. A cause was not discovered in the other 5 animals, although at necropsy, 2 were found to have thyroid tumors. Many pharmacologic treatments were ineffectual, but trials with the benzodiazepine tranquilizer, clonazepam, suggested it will prove useful in controlling violent movements during rapid-eye-movement sleep.  相似文献   

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