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At least 91 records · Page 5Linked to original sources
PubMed1976

Characterization of mammotrophs separated from the human pituitary gland.

Human pituitary tissues from 27 patients and 7 persons post mortem were dissociated into single cell suspensions. On the average, 23% of the cells were mammotrophs. The concentration of prolactin in these suspensions averaged 3.8 ng/1,000 cells. After cell separation by velocity sedimentation at unit gravity, mammotrophs and other cell types were enriched twofold to threefold. The separated mammotrophs retained structural integrity at light and electron microscopic levels. In eight separation experiments, cells recovered from different gradient regions were assayed for intracellular prolactin levels. In cells from "normal" subjects, 8.5% of the prolactin recovered from the gradient was associated with large mammotrophs, whereas in patients with breast cancer, 28% of the hormone was associated with large mammotrophs. The number of mammotrophs recovered from this gradient region (beyond fraction 6) was doubled in breast cancer (2 expts). These mammotrophs showed areas of hypertrophied Golgi and endoplasmic reticulum. Culture of the separated cells from 1 patients with diabetes and 2 patients with breast cancer for 21 days showed that mammotrophs in the upper gradient fractions (diabetic) secreted seven times more hormone than those in the lower regions, whereas those mammotrophs from patients with breast cancer that fell to the lower gradient regions secreted 15 times more prolactin than did those in the upper regions. These data suggest that pituitaries of patients with breast cancer contain a small pool (10-20%) of hypertrophied mammotrophs that have the potential for significant secretory activity in vitro.

Adult↗
PubMedDate not supplied

Dynamic computed tomography of the pituitary gland in dogs with pituitary-dependent hyperadrenocorticism.

Dynamic computed tomography (CT) of the pituitary gland was performed in 55 dogs with pituitary-dependent hyperadrenocorticism (PDH) that underwent transsphenoidal hypophysectomy. On routine contrast-enhanced CT images, microadenomas of the pituitary gland often are indistinguishable from nontumorous pituitary tissue because of isoattenuation. Dynamic CT may allow visualization of these adenomas. The changes in the contrast-enhancement pattern of the pituitary during dynamic CT in 55 dogs with PDH were correlated with surgical and histopathologic findings. In 36 dogs, dynamic CT identified distinct contrast enhancement of the neurohypophysis (pituitary flush). In 24 dogs, this pituitary flush was displaced, which indicated the presence of an adenoma. This observation was confirmed surgically and histopathologically in 18 of the 24 dogs. In 19 dogs, there was a diffusely abnormal contrast-enhancement pattern. CT findings agreed with surgical findings in 13 of these dogs and with histopathologic findings in all 19 dogs. It is concluded that a dynamic series of scans should be included in the CT protocol of the pituitary gland in dogs with PDH because it allows for identification of an adenoma or a diffusely abnormal pituitary gland.

Adrenocortical Hyperfunction↗
PubMed1977

Effect of the isolated removal of the median eminence (ME) and pituitary stalk (PS) on the immunohistology and hormone release of the anterior pituitary gland grafted into the hypophysiotrophic area (HTA) and/or of the in situ pituitary gland.

Isolated removal of the median eminence (ME) and pituitary stalk (PS) of female rats was performed under visual control, using a new instrument to open up the 3rd ventricle. Atrophy of the uterus, the follicles and the intersitial tissue in the ovaries was accompanied by persistent corpora lutea and persistent diestrous vaginal smears in rats which had undergone a successful removal of ME and PS. No change was, however, detected in the weight of the thyroid and adrenal glands at the end of the six weeks experimental period. An adenohypophysis implanted in the place of the ME at the time of the surgery, could not prevent these changes. In animals, in which the removal of the ME was not complete, the changes of the gonadal system were less pronounced. Immunocytology of the pituitary LH-, FSH, TSH- and prolactin-cells in animals with completely removed ME and PS showed inactive LH- and FSH-cells both in the grafted and in situ pituitaries, while the TSH- and prolactin-cells appeared to be in a stimulated state. In animals with ME remnant, LH-RH axon terminals were localized only on the blood vessels of the remnant. The part of the pituitary graft in contact with these blood vessels, as well as some areas of the in situ pituitary gland, contained active LH cells as judged from their size and immunohistological appearance. Since in the absence of the ME, the hypophysiotrophic area is not able to exert its regulatory effect on the gonadotrophs of the pituitary implant in this area, the authors suggest that this effect is mediated by the blood circulation of the ME which is rich in releasing hormones and is drained toward both the anterior pituitary and the medial basal hypothalamus.

Animals↗
PubMed2003

Vascular networks and endothelial cells in the rat experimental pituitary glands and in the human pituitary adenomas.

There has been considerable interest in the relationship between hormone-secreting endocrine cells (HSEC) and their microvessels (MVN) in human pituitary gland. However, microcirculatory networks have rarely been studied in three dimensions (3D). Therefore, this study was designed to visualize and to reveal the relationship between hormone secreting endocrine cells and their microvessel environment including vascular endothelial cells in 3D using rat pituitary glands under various experimental conditions by confocal laser scanning microscopy (CLSM). By CLSM, the 3D distributions of MVN were visualized and revealed a relationship between HSEC and MVN in experimental pituitary glands and human pituitary adenomas. Therefore, 3D reconstructed imaging by CLSM is a useful technique with which to investigate the microvessel environment of hormone-secreting cells and has the potential to reveal dynamic hormone-secreting pathways.

Adenoma↗
PubMed2006

The effect of MR contrast medium dose on pituitary gland enhancement, microlesion enhancement and pituitary gland-to-lesion contrast conspicuity.

INTRODUCTION: The purpose of this study was to compare the differences in gland enhancement, microlesion enhancement and gland-lesion contrast ratio in patient groups in which half-dose (HD), standard-dose (SD) and double-dose (DD) contrast medium was used in pituitary MR imaging. METHODS: Pituitary gland enhancement and microlesion enhancement were measured and gland-lesion contrast ratios were calculated in 18 patients receiving HD (0.05 mmol/kg), 9 receiving SD (0.1 mmol/kg) and 13 receiving DD (0.2 mmol/kg) contrast medium. Gland enhancement and microlesion enhancement over baseline were determined employing DICOM region of interest measurements and compared after normalization to temporal lobe white matter. Contrast ratios and differences were also calculated and compared. RESULTS: Gland enhancement and lesion enhancement were greater with larger contrast medium doses (gland: HD 50%, SD 99%, DD 132%; microlesion: HD 19%, SD 54%, DD 86%). The gland-lesion contrast ratios were similar with the three doses (25.6%), reflecting expected similar fractional contrast medium distributions in spite of different doses. The signal difference between gland and microlesion, therefore, was a fixed percentage of gland enhancement (DeltaS approximately 26%) with greater signal differences with larger contrast medium doses. CONCLUSION: Greater gland-to-lesion signal differences with larger contrast medium doses would likely improve pituitary microlesion visualization and margin characterization aiding in microlesion detection as well as preoperative planning.

Adolescent↗
PubMedDate not supplied

Fetal antigen 1 (FA1) in the adult rat adrenal gland, ovary and pituitary gland.

Fetal antigen 1 (FA1) is a circulating glycoprotein containing six epidermal growth factor (EGF)-like repeats. FA1's larger membrane-bound precursor is defined by the cDNAs referred to as either human delta-like (dlk) or human adrenal specific cDNA, pG2. In rodents FA1 has also been studied under the names of preadipocyte factor 1 (Pref-1), and zona glomerulosa-specific factor (ZOG). FA1 is abundantly expressed in fetal tissues, but in the mature cells of the adult organism the tissue presence of the protein seems to be restricted to neuroendocrine tissues. The present study demonstrates FA1 localisation in endocrine tissues of the adult female rat in which the protein was found present in the medulla and the zona glomerulosa of the cortex of the adrenal glands, in the pars distalis of the adenohypophysis, and in the ovarian granulosa lutein cells. No staining was found in the pancreas, which is in contrast to what has been described in the human.

Adrenal Glands↗
PubMed1988

Quantitative analysis of immunoreactive human growth hormone (HGH) in the secretory granules of normal pituitary glands and hgh-producing pituitary adenomas. An immunoelectron microscopic study using the protein A-gold (PAG) technique.

We applied the protein A-gold (PAG) technique to two normal human pituitary glands and three samples of hGH-producing pituitary adenoma in order to demonstrate immunoreactive hGH at the ultrastructural level. Ultrathin mirror sections immunostained for hGH were observed by electron microscopy and the numbers of immunoreactive gold particles were calculated. The numbers of gold particles of the same secretory granule shared by the mirror sections showed counts which were approximately the same. Thus, assuming that the influence on the hGH antigenicity of the tissue treatment and conditions of immunostaining should be the same at all points on the ultrathin sections, the numbers of gold particles were considered to be a quantitative indicator of the amount of hGH antigen on the secretory granules of sections processed under the same conditions. The numbers of gold particles per micron2 of cut surface of secretory granules in hGH-producing adenoma cells were statistically lower than those of hGH-positive cells from normal pituitary glands, suggesting endocrinological derangement of the tumor cells together with morphological immaturity in their secretory granules and other organelles.

Adenoma↗
PubMed1997

Correlation between impairment of glucocorticoid feedback and the size of the pituitary gland in dogs with pituitary-dependent hyperadrenocorticism.

Under the assumption that the impaired inhibitory effect of glucocorticoids on cell division is an important determinant in the progression of corticotrophic adenomas, it is postulated that the magnitude of proliferation and the resistance to glucocorticoids are correlated. To test this hypothesis, 67 dogs with pituitary-dependent hyperadrenocorticism were studied to determine whether a correlation could be demonstrated between the effect of dexamethasone administration on the activity of the pituitary-adrenocortical axis and the size of the pituitary gland as estimated by computed tomography. The volumes of the pituitary glands as calculated from summations of subsequent images of pituitary areas, ranged from 11.8 to 3238.6 mm3. Among the three dimensions, the height of the pituitary was the most sensitive indicator of enlargement. Calculation of the pituitary height/brain area ratio (P/B ratio) allowed correction for the size of the dog. The P/B ratio had the highest discriminatory power in distinguishing enlarged (n = 41) from non-enlarged (n = 26) pituitaries. The effects of dexamethasone (0.1 mg/kg) on the plasma concentrations of cortisol and ACTH and on the urinary corticoid/creatinine (C/C) ratios were expressed as percentage changes from the initial values. For ACTH, cortisol and C/C ratios these figures for resistance to dexamethasone were significantly correlated with the dimensions of the pituitary, particularly the height, volume and P/B ratio. It is concluded that the magnitude of the expansion of pituitary corticotrophic adenomas is dependent upon the loss of restraint by glucocorticoids, i.e. the degree of insensitivity to glucocorticoid feedback.

Adrenal Cortex↗
PubMed1995

Congenital hypopituitarism with hypoplasia of the anterior pituitary gland and a normal posterior pituitary lobe.

We report a female infant with congenital hypopituitarism. All anterior pituitary hormones were deficient, and the anterior pituitary gland was undetectable on magnetic resonance images. Antidiuretic hormone secretion was appropriate, and the posterior lobe was localized at the end of the stalk, in the sella. These observations suggest that the posterior pituitary gland may develop independently of the anterior lobe.

Female↗
PubMed2001

[Increased T1 signal of the residual normal anterior pituitary gland following medical treatment of pituitary prolactinoma].

PURPOSE: To illustrate that residual normal pituitary gland may show hyperintense signal on T1-weighted image after medical treatment of pituitary prolactinoma. MATERIAL: and methods. Three patients treated with bromocriptine for a prolactinoma and showing hyperintense signal of the residual normal pituitary tissue on T1-weighted images were studied. In all patients, measurements of the anterior pituitary gland signal (APGS) and the temporal lobe white matter signal (TLWMS) were obtained by a "region of interest" (ROI) on coronal T1-weighted images. The APGS/TLWMS ratios were calculated and compared to those of a control group of 30 normal subjects. RESULTS: In the three patients, the measurements obtained by ROI confirmed the visual impression of high signal of the residual normal pituitary tissue. Ratios were ranging from 1.15 to 1.21, while they were ranging, in the control group from 0.92 to 1.09. CONCLUSION: In patients with prolactin-secreting adenoma seen after medical treatment, high signal of the residual normal pituitary tissue can be observed, probably due to cellular hyperactivity as it can be noticed during some physiological states. This pattern has to be differentiated from other pituitary abnormalities demonstrating T1 hyperintensity such as hemorrhagic changes of a prolactinoma.

Adult↗
PubMed2001

Adenocarcinoma of the salivary gland metastatic to the pituitary gland: case report.

OBJECTIVE AND IMPORTANCE: A case of metastasis to the pituitary gland from a ductal adenocarcinoma of the salivary gland is presented. Metastasis to this site is rare, and a salivary gland source has never previously been described. CLINICAL PRESENTATION: This patient presented with hypopituitarism, including diabetes insipidus. INTERVENTION: A craniotomy was performed to alleviate visual loss. The histological features of the sellar tumor were identical to those of a tumor removed from the parotid gland 18 months earlier. CONCLUSION: Although intrasellar tumors originating from embryonic rests of salivary gland tissue have been reported, metastasis from a malignant neoplasm arising within a true salivary gland is also possible and should not be excluded from consideration for patients in whom a salivary gland-like tumor is discovered in the sella turcica.

Carcinoma, Ductal, Breast↗
PubMed2006

Immunohistochemical detection of angiotensin receptors AT1 and AT2 in normal rat pituitary gland, estrogen-induced rat pituitary tumor and human pituitary adenomas.

Male rat pituitary glands, diethylstilbestrol (DES)-induced rat pituitary tumors and 12 human pituitary adenomas were immunostained with antibodies raised against AT1 and AT2 angiotensin receptor proteins. Positive immunostaining of AT1 was observed in a subpopulation of anterior and intermediate pituitary lobe cells as well as in some nerve endings of the neurohypophysis. In the DES-induced rat pituiary tumors, the subpopulation of AT1-immunnopositive cells was smaller than in the non-tumoral anterior pituitary. In human pituitary adenomas, weak AT1 immunostaining was found in 5 tumors. In the remaining adenomas, the AT1 immunostaining was trace (doubtful) or absent. The AT1 immunostaining in the peritumoral non-neoplastic pituitary tissue was stronger than that observed in the tumors. The normal rat pituitaries and rat tumors did not show immunostaining with anti-AT2 antibody. In human pituitary adenomas, the tumoral cells were AT2- negative but moderate to strong AT2 immunostaining was observed in intratumoral blood vessel walls. The data suggest that the experimental (in rat) and spontaneous (in man) pituitary tumorigenesis is associated with the down-regulation of AT1 receptors. The expression of AT2 receptors, in turn, may be connected with the process of tumoral neo-angiogenesis.

Animals↗
PubMed1998

Lack of normal MR enhancement of the pituitary gland: findings in three siblings with combined pituitary hormone deficiency.

We present the MR appearance of the sella turcica in three sibling dwarfs with combined pituitary hormone deficiency in which MR images revealed a peripheral curvilinear band of enhancement about the pituitary gland in all three patients, a normal-size pituitary gland in two siblings, a mildly enlarged pituitary gland in one sibling, and a thin infundibulum and a normal posterior pituitary bright spot in all three siblings. Possible antecedents include an abnormal vascular supply, pituitary gland replacement by a nonfunctioning adenoma, a proteinaceous cyst, or a hamartoma.

Adolescent↗