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Biomedical subjects

C Ezrin

Publications and source records attributed to C Ezrin.

At least 19 recordsLinked to original sources

Hereditary diabetes insipidus: an immunohistochemical study of the hypothalamus and pituitary gland.

We report the histological findings in a case of hereditary diabetes insipidus (HDI) using vasopressin (VP) immunohistochemistry. The hypothalamus displayed a marked loss of magnocellular VP neurons, with preservation of the smaller cells. The neurohypophysis was severely atrophic with scanty immunoreactivity. Our results support the hypothesis that HDI results from a selective degeneration of VP neurons affecting chiefly the magnocellular elements projecting to the neurohypophysis. The sparing of the parvocellular component may reflect the projection of these neurons to non-pituitary targets.

Aged

Sustained pulsatile insulin secretion from adenomatous human beta-cells. Synchronous cycling of insulin, C-peptide, and proinsulin.

The endocrine pancreas secretes insulin in a pulsatile fashion. This rhythm is generated at a site within the pancreas, although its precise location has not been determined. With an in vitro system, we tested the possibility that beta-cells might generate spontaneous pulsatile insulin secretion in the absence of any external influence. Human insulinoma tissue from five patients was perifused for 7-10 h with RPMI-1640 medium and constant concentrations of glucose (5.5 mM). Insulin, C-peptide, and proinsulin were measured in the effluent collected at 3.3-min intervals. All three peptides demonstrated pulsatility of secretion in a similar, synchronous fashion that was sustained throughout each study. The Clifton cycle detection program demonstrated cycling in all five tumors, with an average period for all tumors of 28, 29, and 26 min for insulin, C-peptide, and proinsulin, respectively. Spectral analysis confirmed the regularity and consistency of the hormonal secretory patterns. Mean hormone concentrations secreted by different tumors varied, but insulin and C-peptide were secreted in a nearly 1:1 ratio. This study demonstrates 1) that beta-cells are able to generate spontaneous pulsatile insulin secretory activity, which is independent of innervation or the presence of other islet cells, and 2) proinsulin secretion from the beta-cell also has an inherent pulsatility. The synchrony observed in the cycles of proinsulin and its peptide products confirms their common secretory pathway in the beta-cell. We conclude that the beta-cell may be the originator of insulin cycling.

Adenoma

Metastatic carcinoma to pituitary adenomas: a report of two cases.

Two cases of carcinoma metastatic to pituitary adenomas are reported. One patient had a prostatic adenocarcinoma, giving rise to metastases in an adenoma found incidentally at autopsy; clinically and immunohistochemically, the adenoma showed lack of endocrine activity. The second patient had symptoms of cortisol excess. A corticotroph adenoma associated with a malignant neoplasm was diagnosed ante mortem; at autopsy a pancreatic endocrine neoplasm was found. Immunohistochemistry and electron microscopy were important in elucidating the primary tumor. The formation of extraportal vascular channels and altered blood flow may have importance in the pathogenesis of cancer metastases to pituitary adenomas.

Adenocarcinoma

Rhabdomyosarcoma in the region of the sella turcica.

Intracranial extension of rhabdomyosarcoma from the face, nasopharynx or middle ear is rare. A 16-year-old boy presented with deterioration of vision and headache. CT scan revealed a soft tissue mass occupying the sphenoid and ethmoid sinuses, extending to the suprasellar fossa and impinging on the optic chiasm. The tumour, mimicking pituitary carcinoma, was removed by transsphenoidal craniotomy. Morphologic studies, including immunohistochemistry and electron microscopy, revealed that the tumour was a rhabdomyosarcoma. This case stresses the value of immunohistochemical and ultrastructural studies in the diagnosis of tumours occurring in the region of the sella turcica. The origin of this tumour was thought to be the sphenoid or ethmoid sinus. The pituitary gland appeared intact.

Adolescent

Effects of caloric restriction and exercise on insulin receptors in obesity: association with changes in membrane lipids.

We have studied the effects of supervised caloric restriction and exercise on mononuclear leukocyte lipid composition, membrane fluidity, and insulin receptors in ten nondiabetic obese adults, (175 +/- 9.3% of ideal body weight) and ten normal adult subjects. In a second study, we examined the effects of caloric restriction alone using a very low calorie liquid diet in the treatment of another ten obese adults. In both groups of obese adults, fasting insulin levels were elevated and fell to normal levels following treatment. Insulin binding to monocytes, which was reduced in obese subjects, increased toward normal after short-term treatment; this was due to the restoration of total insulin binding capacity to levels one half of that seen in the normal adult group. Obese subjects undergoing either treatment had elevated membrane cholesterol/phospholipid ratios prior to treatment (0.499 +/- 0.050 and 0.446 +/- 0.011 v 0.400 +/- 0.025 mol/mol in normal adults P less than 0.005 by ANOVA). Prior to treatment, for all subjects there was a significant inverse correlation between insulin tracer binding and membrane cholesterol/phospholipid ratios (r = .484, n = 34, P less than 0.005). This relationship did not change significantly in obese subjects in either treatment group. Cell membrane microviscosity was determined by fluorescence polarization (FP) using DPH (2 X 10(-6) mol/L). Prior to weight loss, obese subjects had significantly higher FP values than controls (0.304 +/- 0.006 and 0.319 v 0.259 +/- 0.009, P less than 0.005, by ANOVA) indicating greater microviscosity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Human fetal adenohypophysis. Histologic and immunocytochemical analysis.

One hundred and forty human fetal pituitary glands were removed from fetuses at 7-40 weeks of gestation and studied by light microscopy and immunocytochemistry to localize adenohypophysial hormones. For immunocytology, the avidin-biotin-peroxidase complex technique was more sensitive and identified hormones in younger fetuses than did the immunoperoxidase method. Adrenocorticotrophin, beta-endorphin, and growth hormone were the first hormones detected; they were identified by intense cytoplasmic immunopositivity at 8 weeks of gestation. Between 10 and 20 weeks, many growth hormone containing cells were large and showed scattered, faint positivity; after 20 weeks, smaller cells with intense positivity predominated. alpha-Subunit of the glycoprotein hormones was identified at 9 weeks of development; beta-subunits of thyroid-stimulating hormone, follicle-stimulating hormone, and luteinizing hormone appeared by 12 weeks. Gonadotrophs differed in numbers related to fetal age and sex. From 15 to 25 weeks, glands of female fetuses contained more gonadotrophs than did those of males; after 25 weeks, there was no significant difference in total gonadotroph numbers. Throughout gestation, adenohypophyses of male fetuses had more luteinizing hormone containing cells than follicle-stimulating hormone containing cells; pituitaries of females had approximately the same numbers of follicle-stimulating hormone containing and luteinizing hormone containing cells. Prolactin was identified in few small cells at 12 weeks; at term, prolactin-containing cells were numerous, comparable to those seen in the hyperplasia of maternal glands in late gestation and during lactation. This comprehensive study indicates morphologic correlations with pituitary hormone extraction data and with the appearance of the various hormones in the fetal circulation.

Adrenocorticotropic Hormone

Regression of pituitary tumors, a possible effect of bromergocryptine.

With the advent of the prolactin radioimmunoassay and more sensitive methods of roentgenologic examination, prolactin-secreting pituitary tumors are now being diagnosed with much greater frequency. Definitive treatment has been considered to involve transphenoidal hypophysectomy. The symptoms of hyperprolactinemia including amenorrhea, galactorrhea and infertility can usually be controlled without difficulty by bromergocryptine therapy, but little is known regarding continued tumor growth. Bromergocryptine and other ergot alkaloids have been shown to decrease the production of prolactin and to inhibit the rate of pituitary tumor growth in animal studies. In man, evidence for a similar effect is not as clear. The present study demonstrates tumor regression associated with bromergocryptine therapy in two patients.

Adult

Cushing's syndrome and autoimmunity.

Is Cushing's syndrome ever caused by adrenal stimulating autoantibodies? Specific antiadrenal antibodies were found in the serum of three of seven patients with Cushing's syndrome. The immunologic techniques that showed positive results were complement fixation, tanned RBC hemagglutination, and immunofluorescence. Lymphocytic infiltration of the adrenal was present in two cases, in one of which nodular hyperplasia seemed to be of primary adrenal origin with autoimmunity as a possible cause. However, in cases with clear-cut pituitary origin, the lymphocytic adrenalitis and circulating adrenal antibodies are likely secondary to antigen leaking from damaged tissue.

Adrenal Glands

Thyrotrophs in old age. An immunocytologic study of human pituitary glands.

In order to reveal whether thyrotroph cells of the human pituitary are affected by aging, a histologic and immunocytologic study was undertaken on the pituitaries of patients over 80 years of age (10 men, 10 women), dying of various acute illnesses and the findings compared with those of a younger age group (10 men, 10 women), dying of various acute illnesses between the age of 20-56 years. The incidence, distribution, granulation, cytoplasmic vacuolization, as well as immunoreactivity of TSH cells, showed no major differences related to age and sex. Lack of involution of thyrotroph cells in old subjects indicates that the pituitary is capable of producing TSH with advancing age.

Adult

Hypothalamic hypopituitarism presenting as galactorrhea-amenorrhea.

A young woman with secondary amenorrhea was also found to have a deficiency of growth hormone. Functional deficiency of adrenocorticotropic and thyroid stimulating hormones, and probably prolactin-inhibiting hormone, developed subsequently. No evidence of a mass lesion in the hypothalamic pituitary axis was found. She failed to respond to any pharmacologic agent believed to act functionally at a suprapituitary level, but responded to all stimuli believed to act directly on the pituitary. This progressive failure of the endocrine hypothalamus may be an extension of the idiopathic hypopituitarism syndrome found in children.

Adult

Isochromosome for the long arm of the Y in an infertile male.

A 37-year-old man investigated for infertility had bilateral atrophic testes. Cytogenetic investigations revealed a chromosome complement of 45,XO/46,Xi(Yq)/46,XY. Mechanisms for the origin of the i(Yq) are considered, and the relation of his chromosome constitution to his infertility and hypogonadism are discussed.

Adult

Pituitary hyperthyroidism. Case report and review of the literature.

A 58 year old woman with an enlarged sella turcica was found to have hyperthyroidism with a supranormal concentration of serum thyrotropin. Transsphenoidal microsurgery resulted in the removal of a chromophobe adenoma comprised mainly of thyrotropes. Postoperatively, serum thyrotropin, thyroxine and triiodothyronine levels fell within normal limits, and the patient maintained normal thyroid and pituitary function.

Adenoma, Chromophobe

Pituitary adenomas associated with elevated blood follicle-stimulating hormone levels: a histologic, immunocytologic, and electron microscopic study of two cases.

The histologic, immunocytologic, and electron microscopic features of pituitary adenomas surgically removed from two men with elevated levels of blood follicle-stimulating hormone (FSH) are described. In both cases, the high blood FSH levels were reduced after surgery. By light microscopy, the tumors corresponded to chromophobic adenomas, and the immunoperoxidase technique revealed the presence of immunoreactive FSH (beta-subunit) in the cytoplasm of the adenoma cells. By electron microscopy, the adenoma cells differed considerably from nontumorous FSH cells. They were smaller and angular and contained numerous microtubules as well as spherical secretory granules measuring 100 to 250 nm in diameter and often lining up along the cell membranes. The present findings are consistent with the view that FSH-producing adenomas may originate in the human pituitary.

Adenoma

Prolactin cell adenomas of the human pituitary. Morphologic features of prolactin cells in the nontumorous portions of the anterior lobe.

Twenty pituitary glands, harbouring prolactin cell adenomas, obtained from autopsy of male and female patients of various ages and dying of different diseases have been investigated by the immunoperoxidase technique in order to reveal the morphologic changes of prolactin cells in the nontumorous protions of the anterior lobes. For comparison, 40 nontumorous pituitary glands and 20 pituitaries lodging adenomas not consisting of prolactin cells have also been studied. In all four prolactin cell adenoma cases, the anterior lobes contained numberous prolactin cells outside the tumors, indicating a lack of involution of prolactin cells in the nontumorous portions of the pituitary glands.

Adenoma