Search PubMed⌕ Search

Biomedical subjects

C T Mooney

Publications and source records attributed to C T Mooney.

22 records · Page 2Linked to original sources

Serum thyroxine and triiodothyronine responses of hyperthyroid cats to thyrotropin.

OBJECTIVE: To document circulating total thyroxine (T4) and triiodothyronine (T3) responses after administration of thyrotropin (thyroid-stimulating hormone [TSH]) to hyperthyroid and healthy cats and assess the value of these responses as an additional diagnostic test for hyperthyroidism. DESIGN: Prospective case series. ANIMALS: 21 healthy and 40 hyperthyroid cats. PROCEDURES: Serum total T4 and T3 concentrations were measured by radioimmunoassay before and 6 hours after administration of 0.5 IU of bovine TSH/kg of body weight. RESULTS: In healthy cats, serum total T4 concentration increased after administration of TSH (mean +/- SD, 114.0 +/- 36.4 nmol/L) representing a mean increment 3 times baseline concentration (mean +/- SD, 33.7 +/- 7.6 nmol/L). In hyperthyroid cats, the relative increase in serum total T4 concentration was significantly (P < 0.001) different; baseline values (mean +/- SD, 236.2 +/- 146.0 nmol/L) increased minimally after TSH administration (mean +/- SD, 308.1 +/- 178.9 nmol/L) There was a significant negative correlation (rs = -0.366) between relative increase in serum total T4 concentration after TSH administration and baseline concentration in hyperthyroid cats. In 3 cats with equivocal baseline serum total T4 concentration, the T4 response to TSH administration was indistinguishable from that in healthy cats. Serum total T3 response to TSH administration was significantly (P < 0.001) lower in hyperthyroid, compared with healthy, cats but the T3 response in healthy cats was more variable than that for T4 CONCLUSIONS: Thyrotoxic cats with high baseline serum total T4 concentration have a limited T4 response to TSH stimulation. Hyperthyroid cats with equivocal baseline serum total T4 concentrations have T4 response after TSH stimulation similar to those of healthy cats. Measurement of serum total T3 concentration provides no additional information. CLINICAL RELEVANCE: The TSH response test is of limited value in diagnosing hyperthyroidism in cats.

Animals↗

Historical, clinical and laboratory features of 126 hyperthyroid cats.

The historical and clinical features and the haematological and biochemical changes in 126 cats with hyperthyroidism are described; 125 of the cats were domestic short- or longhaired, and one was a chinchilla. There were 62 males and 64 females with a mean age of 13.0 years. The duration of signs ranged from two days to two years with a mean of 5.4 months. The historical and clinical features were weight loss, polyphagia, polyuria/polydipsia, tachycardia, hyperactivity, diarrhoea, respiratory abnormalities, other cardiac abnormalities, skin lesions, vomiting, moderately raised temperature, decreased activity, decreased appetite, congestive cardiac failure, haematuria and intermittently decreased appetite. Goitre was palpable in 123 cats. The serum total thyroxine concentrations of the cats were more than three standard deviations above the mean of the reference range. Serum total tri-iodothyronine concentrations ranged from 0.78 to 14.96 nmol/litre and were within the reference range in 11 of the cats. Mild hyperthyroidism was a much commoner cause of high normal or marginally above normal thyroid hormone concentrations than severe, concurrent, non-thyroidal illness. Other common biochemical changes were increased of serum alanine aminotransferase, urea, aspartate aminotransferase, alkaline phosphatase and lactate dehydrogenase. There were minimal changes in the red cell parameters. Leucocyte changes showed two trends: a mature neutrophilia, either with or without an accompanying leucocytosis often in association with a lymphopenia, or an eosinophilia, either with or without a lymphocytosis.

Age Factors↗

Evaluation of the basal and post-adrenocorticotrophic hormone serum concentrations of 17-hydroxyprogesterone for the diagnosis of hyperadrenocorticism in dogs.

Serum concentrations of 17-hydroxyprogesterone and cortisol were measured before and after the administration of exogenous adrenocorticotrophic hormone (ACTH) to three groups of dogs: 27 healthy dogs (group 1), 19 dogs with non-adrenal illness (group 2) and 46 dogs with hyperadrenocorticism (group 3). The median (range) post-ACTH concentrations of 17-hydroxyprogesterone were 5.0 (22.2 to 16.8), 6.9 (2.0 to 36.2) and 14.4 (1.7 to 71) nmol/litre in groups 1, 2 and 3, respectively. There were no significant differences in the basal or post-ACTH concentrations of cortisol or 17-hydroxyprogesterone between groups 1 and 2. The post-ACTH concentrations of 17-hydroxyprogesterone in group 3 were significantly (P<0.001) greater than those in groups 1 and 2 combined. The area under the receiver operating curve (ROC) for the post-ACTH concentration of cortisol (0.94) was significantly greater than that for the post-ACTH concentration of 17-hydroxyprogesterone (0.76). Using a two-graph ROC analysis, a cut-off of 8.5 nmol/litre was found to maximise both the sensitivity and specificity of the post-ACTH concentration of 17-hydroxyprogesterone for the diagnosis of hyperadrenocorticism at 71 per cent. With a cut-off of 4.5 nmol/litre the sensitivity increased to 90 per cent but the specificity decreased to 40 per cent; with a cut-off of 16.7 nmol/litre the specificity increased to 90 per cent but the sensitivity decreased to 47 per cent.

17-alpha-Hydroxyprogesterone↗