Canine thyroid carcinoma

Malignant thyroid carcinomas are relatively common in dogs. The majority of tumors are unilateral and nonfunctional. Before deciding on treatment options, it is important to determine whether the tumor is freely moveable or fixed and invasive into adjacent tissues. Thyroidectomy is recommended for unilateral, mobile thyroid carcinomas. Radiation therapy or radioactive iodine therapy are recommended for dogs with invasive or bilateral thyroid carcinomas. The role of adjunctive chemotherapy is poorly defined, but should be considered in dogs with high-risk tumors, such as large or bilateral thyroid carcinomas. The prognosis is good following surgical treatment of mobile thyroid tumors and irradiation of fixed thyroid carcinomas, with median survival times greater than 3 years.     

Cyclin D1 protein expression in human thyroid gland and thyroid cancer

Cell cycle progression is facilitated by cyclin dependent kinases (CDKs) that are activated by cyclins, including Cyclin D1 and inhibited by CDK inhibitors. Evidence of the involvement of cyclin gene alterations and over expression of various cyclins in human cancer is growing. The role of Cyclin D1 in malignant progression of papillary carcinomas of the thyroid has yet to be established. We therefore studied the expression of Cyclin D1 protein in thyroid carcinomas of young Kuwaiti patients (36 cases of conventional papillary thyroid carcinoma, 12 cases of its follicular variant, one case of tall cell thyroid carcinoma and one case of medullary carcinoma) using immunohistochemistry. In 23 patients (46%) circumscribed areas of cells were detected that showed a distinct to strong nuclear staining for immunoreactive Cyclin D1 whereas the remaining bulk of the carcinoma cells were negative or only showed a slight cytoplasmic staining. None of the tested clinical or path histological parameters showed a statistically significant correlation with the focal immunostaining. This does not rule out that the detected foci with positive nuclear Cyclin D1 immunostaining are areas where a progressive transformation to a more malignant phenotype occurs which eventually leading to lymph node and distant metastases.     

Equine thyroid dysfunction.

Hypothyroidism is the most common type of thyroid gland dysfunction reported in horses. Primary, secondary, and tertiary causes of hypothyroidism are discussed. Equine hypothyroidism remains a controversial endocrine disorder because extrathyroidal factors, including the administration of drugs and systemic diseases, affect serum triiodothyronine (T3) and thyroxine (T3) concentrations in horses. Accurate diagnosis of hypothyroidism therefore requires assessment of the hypothalamic-pituitary-thyroid axis. Diagnostic procedures for evaluating thyroid gland function are outlined and results of studies utilizing experimental models are discussed.     

Feline thyroid surgery.

Hyperthyroidism is the most commonly diagnosed endocrine disease in cats. Surgery is a widely available curative therapy for hyperthyroid cats. Because of the multiple metabolic changes associated with hyperthyroidism, surgical management can be challenging. Multiple methods of thyroidectomy and their associated levels of morbidity are reviewed.     

Feline thyroid storm.

Thyroid storm is a syndrome described in human medicine to define a multisystemic disorder resulting from organ exposure to excessive levels of thyroid hormone. This form of acute thyrotoxicosis, although uncommon, can be life threatening and is a significant cause of mortality in human emergency rooms. Although thyroid storm is a well-recognized clinical entity in human medicine, it has not been described in veterinary medicine. This article discusses the human syndrome and defines a similar syndrome in hyperthyroid veterinary patients. The clinical signs of and treatment modalities for feline thyroid storm are also presented.     

The avian thyroid gland.

There has been a considerable amount of research regarding the function of the avian thyroid gland, particularly in chickens. There is also more information on diseases of the avian thyroid gland, although it is usually in the form of case reports. This article covers a limited amount of material on the structure and function of the avian thyroid gland and its diseases.     

Assessment of the value of quantitative thyroid scintigraphy for determination of thyroid function in dogs

Objective : To assess the value of thyroid scintigraphy to determine thyroid status in dogs with hypothyroidism and various non‐thyroidal illnesses. Methods : Thyroid hormone concentrations were measured and quantitative thyroid scintigraphy performed in 21 dogs with clinical and/or clinicopathological features consistent with hypothyroidism. Results : In 14 dogs with technetium thyroidal uptake values consistent with euthyroidism, further investigations supported non‐thyroidal illness. In five dogs with technetium thyroidal uptake values within the hypothyroid range, primary hypothyroidism was confirmed as the only disease in four. The remaining dog had pituitary‐dependent hyperadrenocorticism. Two dogs had technetium thyroidal uptake values in the non‐diagnostic range. One dog had iodothyronine concentrations indicative of euthyroidism. In the other, a dog receiving glucocorticoid therapy, all iodothyronine concentrations were decreased. Markedly asymmetric technetium thyroidal uptake was present in two dogs. All iodothyronine concentrations were within reference interval but canine thyroid stimulating hormone concentration was elevated in one. Non‐thyroidal illness was identified in both cases. Clinical Significance : In dogs, technetium thyroidal uptake is a useful test to determine thyroid function. However, values may be non‐diagnostic, asymmetric uptake can occur and excess glucocorticoids may variably suppress technetium thyroidal uptake and/or thyroid hormone concentrations. Further studies are necessary to evaluate quantitative thyroid scintigraphy as a gold standard method for determining canine thyroid function.     

Effect of recombinant human thyroid stimulating hormone on serum thyroxin and thyroid scintigraphy in euthyroid cats

This study investigated the thyroidal response to administration of recombinant human thyroid stimulating hormone (rhTSH) by means of serum total thyroxine (TT(4)) concentration and pertechnetate uptake by the thyroid gland in six healthy euthyroid spayed female cats. A pertechnetate scan was performed on day 1 to calculate thyroid/salivary gland (T/S) uptake ratio. On day 3, 25 microg rhTSH was injected intravenously. Six hours later the thyroid scan was repeated as on day 1. Blood was drawn for serum TT(4) measurement prior to injection of rhTSH and performance of the pertechnetate scan. Statistically significant differences in mean serum TT(4) concentration, T/S uptake ratio before and 6h after rhTSH administration and T/S uptake ratio between left and right lobes were noted. We can conclude that 25 microg rhTSH increases pertechnetate uptake in the thyroid glands of cats, this should be taken into account when thyroid scintigraphy after rhTSH administration is interpreted.     

犊牛甲状腺细胞的制作

犊牛甲状腺细胞对口蹄疫病毒特别敏感 ,并能产生很高的病毒滴度。该细胞制作的成功对口蹄疫病毒的分离鉴定有重要意义。本文报告了该细胞的制作方法。