Articles: brain.
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Thyroid hormones play an important morphogenetic role during the fetal and neonatal periods and regulate numerous metabolic processes. In the central nervous system, they control myelination and overall brain development, regional gene expression, and regulation of oxygen consumption. Their deficiency in the fetal and neonatal periods causes severe mental retardation, due to lack of thyroid function, or to iodine deficiency. ⋯ We induced hypothyroidism by administering mercaptomethylimidazole to pregnant mothers, from the seventh day of gestation until the sacrifice of the offspring. The results show a delay in the evolution of the expression of the two isoforms of the enzyme nitric oxide synthase in hypothyroid animals, followed by an anomalous overexpression in later stages. Finally, the expression of nitrotyrosine follows an evolution that is synchronized with that shown by both isoenzymes in control and hypothyroid animals.
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Aims/Background Previous research has shown that smoking tobacco is associated with changes or differences in brain volume and cortical thickness, resulting in a smaller brain volume and decreased cortical thickness in smokers compared with non-smokers. However, the effects of smokeless tobacco on brain volume and cortical thickness remain unclear. This study aimed to investigate whether the use of shammah, a nicotine-containing smokeless tobacco popular in Middle Eastern countries, is associated with differences in brain volume and thickness compared with non-users and to assess the influence of shammah quantity and type on these effects. ⋯ Furthermore, yellow shammah users exhibited smaller volumes in the right lateral ventricle (p = 0.02), total lateral ventricle (p = 0.03), and right putamen (p = 0.02) compared with users of other types of shammah. Regarding cortical thickness, significant differences were observed in the right medial orbito-frontal thickness (p = 0.03), left rostral middle frontal thickness (p = 0.03), and right rostral anterior cingulate thickness (p = 0.04). Conclusion These findings shed light on the potential neurobiological effects of shammah use, particularly the yellow shammah, and highlighting the need for further research to fully understand its implications for brain structure and function.
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Traumatic brain injury (TBI) is a significant health issue among veterans and poses a substantial risk for pituitary injury. Consensus guidelines recommend that patients who have sustained a TBI should undergo a baseline pituitary hormonal evaluation after the primary brain insult. Patients with abnormal screening test results or with symptoms of hypopituitarism should be referred to endocrinology for a full assessment. Currently, there are no reported data on the screening rates of hypopituitarism in veterans with TBI. This pilot study was conducted to determine the frequency of screening for hypopituitarism in veterans with TBI in a primary care clinic setting. ⋯ We report that the screening rate for hypopituitarism in TBI patients is exceedingly low in the primary care setting, even with the less rigorous newer screening recommendations. Measures should be taken to improve screening of hypopituitarism to decrease morbidity and improve the quality of life in patients with a history of TBI.