Effect of a bradykinin potentiating factor separated from honey bee venom on thyroid gland and testis in hypothyroid white rats

Background Animal venoms have been known as a source of drugs beneficial to human health. Accordingly, this study was designed to determine the effect of bradykinin potentiating factor (BPF) separated from honey bee venom, Apis mellifera on histological structure, thyroid and male sex hormones of the thyroid gland and testis in a model of hypothyroid male white rats induced by carbimazole. Results This study includes male rats divided into 6 main and sub-groups (10 rats in each group). Control group, carbimazole group, levothyroxine group, BPF group, carbimazole group treated with levothyroxine and carbimazole group treated with BPF. At the end of experiments (60 days) rats were sacrificed and dissected; the blood was collected for determination of thyroid and male sex hormones. Also, the thyroid gland and testis were taken to histological study. The results indicated that, carbimazole group showed a highly significant decrease in thyroid hormones (T4, T3, Ft4 and Ft3) and male sex hormones (LH, FSH and testosterone), but a significant increase in TSH compared to control group. The results revealed that, treated groups with levothyroxine or BPF have significant increase in thyroid and male sex hormones and significant decreasein TSH. A significant improvement was detected in co-treated groups (hypothyroid groups) with levothyroxine or (BPF). Also, the present study showed a histopathological change in thyroid gland and testis of hypothyroid male rats. Conclusion Treated hypothyroid rats with levothyroxine as a drug and BPF as a natural product showed an improvement of these complications induced by carbimazole in thyroid gland and testis. Therefore, BPF may be benefical in treatment of hypothyroidism.

ONTOGENETIC, BREED, AND SEASONAL FEATURES OF THE SYNTHESIS OF THYROXIN AND CORTISOL IN DOGS AND CATS

The article presents data on the breed and seasonal characteristics of the synthesis of thyroxine and cortisol in dogs of different breeds and cats that do not have a breed. It has been shown that the synthesis of thyroxine in dogs and cats depends on the breed, age and season. The functional activity of the thyroid gland in dogs decreases by 10-12, and in cats by 9-13 years of age. The highest level of thyroxine production throughout the entire research period belongs to the Griffon Petit-Brabancons. The synthesis of cortisol in dogs and cats is stable and does not undergo statistically significant changes. Seasonal dynamics of thyroxine is observed in dogs, but absent in cats. No sea-sonal dependence of cortisol synthesis has been reported in dogs and cats.

Association between exposure to radioactive iodine after the Chernobyl accident and thyroid volume in Belarus 10-15 years later

Background While there is a robust literature on environmental exposure to iodine-131 (131I) in childhood and adolescence and the risk of thyroid cancer and benign nodules, little is known about its effects on thyroid volume. Methods To assess the effect of 131I dose to the thyroid on the volume of the thyroid gland, we examined the data from the baseline screening of the Belarusian-American Cohort Study of residents of Belarus who were exposed to the Chernobyl fallout at ages ≤18 years. Thyroid dose estimates were based on individual thyroid activity measurements made shortly after the accident and dosimetric data from questionnaires obtained 10-15 years later at baseline screening. During baseline screening, thyroid gland volume was assessed from thyroid ultrasound measurements. The association between radiation dose and thyroid volume was modeled using linear regression where radiation dose was expressed with power terms to address non-linearity. The model was adjusted for attained age, sex, and place of residence, and their modifying effects were examined. Results The analysis was based on 10,703 subjects. We found a statistically significant positive association between radiation dose and thyroid volume (P < 0.001). Heterogeneity of association was observed by attained age (P < 0.001) with statistically significant association remaining only in the subgroup of ≥18 years at screening (P < 0.001). For this group, increase in dose from 0.0005 to 0.15 Gy was associated with a 1.27 ml (95% CI: 0.46, 2.07) increase in thyroid volume. The estimated effect did not change with increasing doses above 0.15 Gy. Conclusions This is the first study to examine the association between 131I dose to the thyroid gland and thyroid volume in a population of individuals exposed during childhood and systematically screened 10-15 years later. It provides evidence for a moderate statistically significant increase in thyroid volume among those who were ≥ 18 years at screening. Given that this effect was observed at very low doses and was restricted to a narrow dose range, further studies are necessary to better understand the effect.

Curious case of Retrosternal Colloid Goitre

Background: Retrosternal goitre is considered to be a rare entity. It is a slow growing enlargement of the thyroid gland which remains asymptomatic for many years. Symptoms are mainly due to compression of airways and oesophagus. Surgical management with the removal of the involved lobe is considered sufficient. Summary: Here we report a case of a 33 yrs. old lady who presented to us with complaints of neck pain, facial flushing, difficulty in breathing and vague body ache. Clinical examination was within normal limits. The patient was referred to orthopedician for further evaluation. MRI cervical spine was done which was suggestive of large swelling in left lobe of thyroid with retrosternal extension causing deviation of trachea to opposite side. FNAC was done which was inconclusive. The involved lobe was removed surgically with frozen section suggestive of Colloid goitre. Conclusion: Retrosternal goitre are slow growing enlargement of thyroid gland which may present with vague symptoms, best managed surgically often followed relief from the symptoms post-surgery.

Cellular and molecular basis of thyroid autoimmunity

Autoimmune thyroid disease (AITD) is the most common human autoimmune disease. The two major clinical manifestations of AITD are Graves’ disease and Hashimoto’s thyroiditis (HT). AITD is characterized by lymphocytic infiltration of the thyroid gland, leading either to follicular cell damage, thyroid gland destruction, and development of hypothyroidism (in HT) or thyroid hyperplasia, induced by thyroid antibodies which activate thyrotropin receptor (TSHR) on thyrocytes, leading to hyperthyroidism. The aim of this review is to present up-to-date picture of the molecular and cellular mechanisms that underlie the pathology of AITD. Based on studies involving patients, animal AITD models, and thyroid cell lines, we discuss the key events leading to the loss of immune tolerance to thyroid autoantigens as well as the signaling cascades leading to the destruction of thyroid gland. Special focus is given on the interplay between the environmental and genetic factors, as well as ncRNAs and microbiome contributing to AITD development. In particular, we describe mechanistic models by which SNPs in genes involved in immune regulation and thyroid function, such as CD40, TSHR, FLT3, and PTPN22, underlie AITD predisposition. The clinical significance of novel diagnostic and prognostic biomarkers based on ncRNAs and microbiome composition is also underscored. Finally, we discuss the possible significance of probiotic supplementation on thyroid function in AITD.