Body mass index and thyroid function in adolescent girls

Ultrasonographic assessment of the thyroid gland and adjacent anatomic structures in Indo-Pacific bottlenose dolphins (Tursiops aduncus)

OBJECTIVE

To evaluate the use of ultrasonography for thyroid gland assessment in healthy Indo-Pacific bottlenose dolphins (Tursiops aduncus), describe the ultrasonographic appearance of the thyroid gland and adjacent anatomic structures, and identify potential associations between variations in thyroid gland morphology and demographic features in this species.

ANIMALS

18 captive Indo-Pacific bottlenose dolphins.

PROCEDURES

1,404 ultrasonographic examinations of the thyroid gland and adjacent anatomic structures (eg, cervical lymph nodes, musculature, and vasculature) were performed during the > 3-year study period. Shape, echogenicity, and homogeneity of thyroid glands were assessed, and glands were categorized into morphological configurations on the basis of results of 2-D and 3-D ultrasonographic evaluation. Associations between demographic factors and thyroid gland morphology were assessed.

RESULTS

Thyroid lobes appeared elliptical or fusiform in the transverse scan plane and round to oval in longitudinal scan planes; morphologically, glands comprised 2 lobes joined by an isthmus or a roughly diamond-shaped structure located on the ventral surface of the trachea. Major blood vessels and cervical lymph nodes were identified. Thyroid parenchyma was typically uniform and homogeneous, with echogenic reticulations and well-defined borders. Thyroid glands were hypoechoic or isoechoic relative to the sternocephalicus muscle; echogenicity was greater in adolescents than in adults. Thyroid gland volume differed between sexes, between sexually mature and immature dolphins, and among age groups and was positively correlated with body length and weight.

CONCLUSIONS AND CLINICAL RELEVANCE

Ultrasonography provided a reliable and repeatable method for evaluation of thyroid glands and adjacent anatomic structures in live dolphins.

The children reference range of thyroid hormones in Northern Iran

Hypothyroidism is associated with mental and growth abnormality in children. The aim of this study was to determine the reference range of thyroid stimulating hormone (TSH). Thyroxin (T4) and triodothyronine (T3) of children in Northern Iran. The sample population for this study consists of subjects of 4 age groups up to 21 years. The subjects were selected randomly from people referred to Danesh Medical Diagnostic Laboratory in Gorgan Northern Iran. Thyroid hormone level were investigated with Radio immunoassay. The mean concentration for T4, T3, TSH for the sample population of 4 groups were as follow (113.5, 107.4, 102.9, 99.2 nmol L(-1)), (1.9, 1.7, 1.9, 1.6 nmol L(-1)) and (2.1,3.5, 2.9, 2.7 mIu L(-1)). The mean value of T3, TSH were higher for females but the mean value of T4 was slightly higher in males. The findings of this investigation indicated that there is an inverse age correlation in particular for T4 in all age groups. On the bases of the results from this study, we conclude that reference range, in all age groups and lower, upper limits of our reference range are not universally similar; therefore determination of reference range in each region is a critical need for clinical practice.