Mineral metabolism and parathyroid gland

7. Mineral metabolism and parathyroid gland

Four parathyroid glands located adjacent to the thyroid gland. The two superior glands are usually found near the posterior aspect of the thyroid capsul, and the inferior glands are located most often located near the inferior thyroid margin. The parathyroid gland composed of epithelial cell and stromal fat. The epithelial cell consist of chief cell and oxyphil cell, both contain of parathyroid hormone PTH. The function of PTH is to regulate serum calcium levels by concerted effects on three target organs: bone, intestinal mucosa, and kidney. 8. Adrenal gland and disorders The adrenal cortex produces many steroid hormones, the most important are cortisol, aldosterone, and the adrenal androgen. Disorders of the adrenal glands lead to a classic endocrinopathies such as Cushing’s syndrome, Addison’s disease, hyperaldosteronism and the syndrome of congenital adrenal hyperplasia. The adrenal medulla is a specialized part of the symphathetic nervous system that secretes catecholamines. Pheochromacytoma is tumors that arise from the adrenal medulla, may present at any age. Screening for pheochromacytoma should be considered for such patients with severe hypertension and also for hypertensive patients with suspicious symptoms, e.g., headache, palpitation, sweating episodes, or unexplained bouts of abdominal or chest pains. 9. Congenital hypothyroid and ambiguous genital Congenital hypothyroidism CH occurs in babies who are born without the ability to produce adequate amounts of thyroid hormone. Thyroid hormone is important for normal function of all of the bodys organs and is essential for normal brain development. CH affects about one in every 3,500 babies. The most common cause of primary CH is dysgenesis various abnormalities in the formation of the thyroid gland. If detected early a child will develop normally. Treatment is thyroid medication daily. Deficiency of thyroid hormone may result in mental and growth retardation. If CH is not diagnosed and treated early in life, most infants will still appear clinically normal before 3 months of age, by which time some brain damage has usually occurred. Symptoms or signs, when present, may include prolonged neonatal jaundice, constipation, lethargy and poor muscle tone, poor feeding, a large tongue, coarse facies, wide fontanelle, distended abdomen and umbilical hernia. Ideally a neonatal screening TSH screening for CH should be routinely done in all children as treatment of affected infants within 45 days of birth leads to normal mental development. The TSH should be done 3 to 5 days after birth and patients with TSH levels more than 20-25 mUL should be assessed further. Once clinically suspected or a positive neonatal screening test; the diagnosis is confirmed by serum T4 and TSH levels. The TSH will be elevated 10 mcUml and T4 will be low 6.5 mcgdl in neonatal period in patients with CH. 20 of the infants may have normal T4 with modest TSH elevations. Such infants may require repeat examinations to establish a diagnosis of CH. Treatment should be started as soon as diagnosis is confirmed. The goal of therapy is early, adequate thyroid hormone replacement. It is desirable to maintain the serum T4 in the upper half of normal range in infants. An initial dose of thyroxine at 10-15 mcgkgday is recommended to minimize IQ loss. T4 and TSH should be monitored at regular intervals. Over treatment should be prevented and can be recognized by signs such as tachycardia, excessive nervousness, disturbed sleep pattern, advanced bone age and craniosynostosis. Udayana University Departement of Medicine Education, DME 17 Disorder of sex development DSD In human sexual development, the female phenotype represents the default pathway. therefore, a failure of testis determination results in the development of the female phenotype, while genetic alterations resulting in partial testicular development can give rise to a wide spectrum of masculinization. In addition to defects in peptide hormones and their receptors, timing of hormonal exposure is also critical to appropriate development. Genital anomalies are estimated to occur in 1 in 4500 births. Disorder of sex development DSD is a medical term referring to congenital conditions in which development of chromosomal, gonadal, or anatomical sex is atypical. Patients with ambiguous genitalia have disorders of sexual development DSD, that previously termed intersex conditions. The term DSD in lieu of potentially pejorative and confusing terms such as intersex, pseudohermaphroditism, hermaphroditism, sex reversal, and gender-based diagnostic labels. For clinical purposes, DSDs in newborns are classified according to karyotype. Based on the various steps of sex differentiation and development, we suggest the following classification: A DSD with a 46,XY karyotype formerly referred to as male pseudohermaphroditism, undervirilization of an XY male and undermasculinization of an XY male. In 46,XY DSD the bipotential gonads differentiate to variable degrees into testes, B DSD with a 46,XX karyotype formerly referred to as female pseudohermaphroditism or masculinization of an XX female. In 46,XX DSD the bipotential gonads usually differentiate into ovaries but with abnormally increased androgen exposure and C DSD with an unusual karyotype such as mosaicism 45,XO46,XY or 46,XX46,XY, transposition of genes 46,XX, SRY+ or chromosome deletions that include one of the genes necessary for sex determination and differentiation. For optimal clinical management of individuals with DSD, the consensus statement recommends the following: Avoid gender assignment in newborns before expert evaluation. Conduct evaluation and long-term management at a center with an experienced multidisciplinary team, including pediatric subspecialists in endocrinology, surgery or urology or both, psychologypsychiatry, gynecology, genetics, neonatology, and, if available, social work, nursing, and medical ethics. Give a gender assignment to all individuals. Openly communicate with patients and families and encourage their participation in decision making. Respect patient and family concerns, and address them in strict confidence.

10. Drug treatment in endocrine disorders