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17Beta-hydroxysteroid dehydrogenase (17betaHSD) isoforms reversibly catalyze the final step in the formation of estradiol (E2) from estrone (E1) and the formation of testosterone from androstenedione. We have investigated 17betaHSD type 1, 2, 3, and 4 gene expression and 17betaHSD estrogenic activity in human anterior pituitary adenomas. 17BetaHSD messenger ribonucleic acid (mRNA) expression was studied by RT-PCR in 42 pituitary tumors and 3 normal pituitaries, 17betaHSD activity was studied in 11 tumors and 17betaHSD type 1 was immunolocalized in vitro in 6 tumors. 17BetaHSD type 1 gene expression was detected in 34 of 42 adenomas in all tumor subtypes; 17betaHSD type 2 mRNA was detected in 18 of 42 adenomas, but not in prolactinomas; 17betaHSD type 3 mRNA was detected in 12 of 42 adenomas, but not in corticotropinomas; 17betaHSD type 4 was expressed in 20 of 42 adenomas by all adenoma subtypes. Reversible 17betaHSD activity was found in 9 of 11 adenomas, and 17betaHSD type 1 immunopositivity was cytoplasmically distributed in all 6 adenomas in vitro. All 4 17betaHSD isoforms are variably expressed in human anterior pituitary adenomas, which also show 17betaHSD enzyme activity, suggesting that 17betaHSD may play an important role in regulating the local cellular levels of estradiol.

Unlabelled: Cell density effects were investigated on tumorous hormonal secretion from 10 pituitary adenomas: 3 somatotrophinomas secreting GH and PRL; 7 gonadotrophinomas, 3 co-secreted both FSH and LH, all 7 secreted LH. Enzymatically dispersed tissue was plated out in 24-well plates at 5 x 10(5), 10(5), 5 x 10(4) and 10(4) cells/well in serum-free media. Media were collected weekly for 2 weeks., Results: In 3 of 3 somatotrophinomas, GH and PRL secretion was higher (p < 0.05) at both week 1 and 2 from 10(4) cells/well, but similar at other cell densities. In all 3 gonadotrophinomas, the FSH secretory rate was highest at 5 x 10(5) cells/well which fell as cell density decreased. Conversely, in 7 of 7 gonadotrophinomas the LH secretory rate was highest at 10(4) cells/well (p < 0.01) which fell as cell density increased., Conclusion: These data suggest that paracrine factors may modulate tumorous GH, PRL, FSH and LH secretion, and show that FSH and LH secretion vary inversely as cell density increases.

The authors compared detection methods for cell proliferation in human anterior pituitary adenomas using histological sections and dispersed cell culture. After tumor cells had been grown for 4 days in dispersed culture, bromodeoxyuridine (BUdR), proliferating cell nuclear antigen (PCNA), and Ki-67 were compared by double immunostaining and contrasted with single staining of PCNA and Ki-67 indices in the corresponding histological sections from 12 human pituitary adenomas. In vitro, the BUdR labeling index was positive in six of 12 tumors (range < 0.1-5.1%), 10 of 12 tumors were PCNA-positive (range < 0.1-100%), and Ki-67 was positive in 10 of 12 adenomas (range < 0.1-8%). In vitro, BUdR and Ki-67 gave similar proliferative indices for 10 of 12 adenomas. In vivo, the PCNA labeling index was positive in 12 of 12 adenomas (range 0.9-95%) and Ki-67 was positive in 11 of 12 adenomas (range < 0.1-2%). Tumors with a labeling index less than 0.1% were considered to be negative for proliferation. High PCNA values were found in vitro and in vivo, whereas Ki-67 labeling indices were similar in vitro and in vivo for nine of 12 adenomas. It is concluded that Ki-67 proliferative indices in vivo reflect those found in vitro, at least after 4 days in dispersed culture, but that PCNA overestimates pituitary adenoma proliferation in histological sections as well as in dispersed culture.

Human anterior pituitary adenomas proliferate and express the p53 tumour suppressor gene protein, but it is not known if apoptosis (programmed cell death) occurs. Therefore, the detection of apoptosis was undertaken in tumorous human anterior pituitary tissue and compared with p53 protein expression, tumour type and tumour size. Apoptosis (detected by the in situ end labelling technique) and p53 suppressor gene protein (detected by DO.1-antibody immunocytochemistry) were determined in formalin-fixed and paraffin-embedded tissue from 37 human pituitary adenomas (2 macroprolactinomas, 9 somatotrophinomas and 26 non-functioning adenomas). Two normal anterior pituitaries were also included in this study. Pre-operative tumour size was scored 1 to 4 from magnetic resonance imaging radiology. Apoptosis was found in 7 of 29 tumours (24%), 11% of somatotrophinomas and 33% of non-functioning adenomas, although this difference was not significant. The p53 tumour suppressor protein was found in 7 of 31 tumours (23%), 33% of somatotrophinomas and 19% of non-functioning adenomas. Apoptosis and p53 protein expression were not found in normal anterior pituitary. In conclusion, apoptosis occurs in human anterior pituitary adenomas, but no significant association was found between apoptosis and p53 protein expression, tumour type or tumour size.

Objective: There is increasing evidence for the role of cytokines in pituitary differentiated function and tumorigenesis, but the spectrum of cytokines found in the pituitary is unknown. Therefore profiles of cytokine expression were determined in different human anterior pituitary adenoma sub-types., Design: The reverse transcriptase-linked polymerase chain reaction (PCR) was used to identify the presence of cytokine mRNA within human pituitary adenomas., Patients: Seventeen pituitary adenoma biopsies removed at transsphenoidal surgery were examined: 4 somatotrophinomas, 7 non-functional adenomas, 4 prolactinomas, one case of Cushing's disease and one case of Nelson's syndrome., Measurements: RNA was extracted from each adenoma biopsy and reverse transcribed into cDNA. This was specifically amplified in a PCR using oligonucleotide primers complementary to each cytokine. The cytokines investigated were interleukin (IL)-I alpha, IL-I beta, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, tumour necrosis factor (TNF)-alpha, TNF-beta and transforming growth factor (TGF)-beta 1, beta 2 and beta 3. The products of each PCR were visualized using agarose gel electrophoresis., Results: All 17 adenomas expressed IL-8 transcripts, but no expression of IL-2, IL-5 or IL-7 was found. IL-6 was expressed in all 4 somatotrophinomas, 3 of 7 non-functional tumours, 2 of 4 prolactinomas and in the single case of Nelson's syndrome. At least one of the 3 isoforms of TGF-beta was found in all but 2 tumours; one prolactinoma and one non-functional adenoma. IL-1 alpha, IL-beta, IL-4, TNF-alpha and TNF-beta were expressed sporadically by individual adenomas., Conclusion: These data suggest that whilst IL-8 may be important, the local expression of the cytokines IL-2, IL-5 and IL-7 is not important in human anterior pituitary tumorigenesis.

Objective: The human pituitary gland is affected selectively by conditions associated with iron deposition, but the mechanisms for this are unknown. In this study we have determined whether the transferrin receptor, which mediates iron uptake by cells, could be detected immunocytochemically in human pituitary adenomas in vitro., Patients: Data were derived from 35 patients undergoing transsphenoidal surgery and included 13 with clinically non-functioning adenomas, 15 with acromegaly, 4 prolactinomas, 2 patients with Cushing's disease and one patient with Nelson's syndrome., Measurements: Transferrin receptor immunopositivity was determined for each adenoma in dispersed cell culture using a specific monoclonal antibody., Results: Eight of 13 clinically functionless adenomas showed immunopositive transferrin receptor expression, whilst adenomas from 15 patients with acromegaly, 4 prolactinomas, 2 Cushing's syndrome and one patient with Nelson's syndrome were negative. The eight transferrin receptor positive tumours were gonadotrophinomas and accounted for eight of the nine tumours which secreted and immunostained for FSH; all eight also secreted and immunostained for LH., Conclusions: These findings may reflect a special requirement for iron by gonadotrophin secreting cells in comparison to other pituitary cell types and this could underlie the reasons why in the normal pituitary these cells are especially susceptible to malfunction in iron overload syndromes such as genetic haemochromatosis and beta-thalassaemia.

Objective: IGF-I inhibits GH secretion from normal and some tumorous pituitary tissue, and has been shown to be mitogenic for gonadotrophinoma cells in vitro. It is not known whether IGF-I affects somatotrophinoma cellular proliferation or the secretion of other hormones, such as PRL and alpha-subunit, which are often co-secreted by these tumours. We have therefore examined the effects of IGF-I on proliferation and hormonal secretion of human somatotrophinomas and prolactinomas in vitro., Design: Pituitary adenoma tissue was dispersed to single cells in monolayer culture. The effects of 100 nM IGF-I on GH, PRL and alpha-subunit secretion were determined over 4-hour and over 4-day periods, and a 4-day dose-response study using 1-100 nM IGF-I was performed on two tumours. Adenoma cell S-phase proliferation was determined after bromodeoxyuridine incorporation for 1 hour after 4 days, using a double immunostaining method., Results: Over 4 hours, 100 nM IGF-I had no effect on GH, PRL or alpha-subunit secretion in 7 tumours. Over 4 days, 100 nM IGF-I reduced GH secretion in 5/8 somatotrophinomas (range 17-84%, P < 0.05) compared to controls, with tumours responding to IGF-I having lower basal serum and in-vitro GH levels than tumours unaffected by IGF-I (P < 0.05). There was no effect on alpha-subunit secretion in any of the three tumours studied. PRL cosecretion was increased in 3/5 somatotrophinomas compared to control (20, 30 and 37%, P < 0.05), with tumours responding to IGF-I being associated with lower basal serum and in-vitro PRL levels than those tumours unaffected by IGF-I. IGF-I also increased PRL secretion in 2/2 prolactinomas (27 and 32%, P < 0.05) compared with control. GH was inhibited and PRL secretion was stimulated by 1 and 10 nM IGF-I in the two dose-response studies. The proliferative labelling index did not exceed 1.9% in any tumour and no proliferative effect was found with 100 nM IGF-I in any somatotrophinoma., Conclusion: IGF-I inhibited tumorous GH in 62% and stimulated PRL secretion in 71% of tumours over 4 days, without affecting alpha-subunit secretion or being mitogenic for somatotrophinoma cells in vitro. No hormonal effects were observed over short (4-hour) incubations. IGF-I may be a newly recognized factor directly stimulating tumorous PRL secretion.

A 51-year-old man had been treated for hyperthyroidism with antithyroid drugs for 8 years. He was then found to have a large pituitary adenoma with biochemical evidence of overproduction of TSH, FSH and alpha-subunit. Subsequent immunocytochemical and tissue culture studies confirmed secretion of these hormones. In addition, the tumour stained for GH and was capable of GH production in vitro. This combination of hormones produced by a pituitary adenoma has not been previously reported.

The effects of human recombinant insulin-like growth factor 1 (IGF-1) on the secretion, viability, and proliferation of dispersed human anterior pituitary adenomas secreting FSH, LH, and alpha-subunit (alpha-su) were examined in vitro over 4 h and 4 days. The acute effect of IGF-1 on secretion over 4 h was examined in four tumors secreting FSH, LH, and alpha-su. IGF-1 (100 nmol/L) reduced LH compared to control (100%) in one tumor (61%, P < 0.01), and three tumors remained unaffected. FSH and alpha-su secretion were insufficient to measure over 4 h. Nine tumors were studied over 4 days; relative to control, IGF-1 (100 nmol/L) increased FSH secretion in all seven tumors secreting FSH (28-266%, P < 0.05) and increased alpha-su secretion in all four tumors studied (36%, 63%, 91%, and 121%, P < 0.05). IGF-1 reduced LH secretion in four/nine tumors (13%, 23%, 32%, and 50%, P < 0.05). Dose response curves (1-100 nmol/L IGF-1) were performed on three tumors cosecreting FSH and LH. Stimulation of FSH was achieved with either 1 or 10 nmol/L IGF-1, a single tumor in which alpha-su was measured showed maximal stimulation at 10 nmol/L IGF-1, and one of three tumors showed LH inhibition with 100 nmol/L IGF-1. In situ viability of attached cells was assessed with fluorescein and propidium iodide in seven tumors. After 4 days' exposure to 100 nmol/L IGF-1, in situ viability was increased in five tumors (range 12-19%, 15 +/- 1.3% SEM, P < 0.05). The effects of IGF-1 on the adenoma cell proliferative S-phase fraction was determined in six tumors after 4 days of treatment using double immunostaining with bromodeoxyuridine incorporation for 1 h. In four/six adenomas that stained positive for bromodeoxyuridine in the controls (1-5.6%), the S-phase fraction was increased by 100 nmol/L IGF-1 [(range 2.1-10.6%, increase 90-220%) (P < 0.05)]. These results show that IGF-1 has differential effects on gonadotropins from human pituitary adenomas, stimulating intact FSH and alpha-su, inhibiting or being without effect on intact LH in vitro, and increasing both viability and number of tumorous glycoprotein-secreting cells entering into the S-phase of proliferation.

The effects of human recombinant basic fibroblastic growth factor (bFGF) on the secretion and/or proliferation of 26 human anterior pituitary adenomas secreting PRL alone (6 tumors), PRL and GH (18 tumors), or GH alone (2 tumors) were examined. Secretory studies were performed over 4 h, 4 days, and 21 days, and proliferation studies over 4 days. The acute effect of bFGF on secretion over 4 h was examined in 10 tumors. bFGF (10 nmol/L) increased PRL compared to that in controls (100%) in 2 tumors (126% and 290%; P < 0.05) and PRL and GH in a third tumor (183% and 133%, respectively; P < 0.05), whereas 7 tumors remained unaffected. Fourteen tumors were studied over 4 days. bFGF (10 nmol/L) increased PRL secretion in 9 of 11 tumors (117-525%; P < 0.05) cosecreting PRL and GH and in all 3 tumors secreting PRL alone (156%, 183%, and 691%; P < 0.01). Dose-response curves with 0.1, 1, and 10 nmol/L bFGF in 2 of these tumors cosecreting GH and PRL showed that stimulation was achieved with all 3 concentrations. bFGF (10 nmol/L) stimulated GH secretion in 2 of 11 mixed tumors (159% and 196%, respectively; P < 0.05). In 2 tumors studied over 3 weeks, 5 nmol/L bFGF stimulated PRL secretion progressively without affecting GH secretion (106% and 207%; P < 0.05). Tissue proliferation was determined by double immunostaining after bromodeoxyuridine incorporation for 1 h in 7 tumors after 4 days. The labeling index did not exceed 1.2% in any tumor, and there was no effect of 10 nmol/L bFGF on the proliferation of adenoma cells. These results suggest that bFGF may have a paracrine role in the stimulatory regulation of PRL secretion in human pituitary adenomas, and these effects are most likely due to increased hormonal synthesis. An in vitro cell culture system can be used to study proliferative potential. However, bFGF is not mitogenic for human anterior pituitary adenomas secreting PRL and PRL plus GH in vitro.

Pituitary apoplexy has been reported as a rare complication of combined tests and of TRH administration in prolactinomas. A 54-year-old man with a pituitary macroadenoma had a single injection of 100 micrograms GnRH. Twenty minutes later he complained of increasing headache and vomited. These symptoms settled spontaneously and were attributed to the pharmacological effects of GnRH. Five hours later he was found to be blind and disorientated without spontaneous complaint. Emergency CT showed a large adenoma with central necrosis, consistent with pituitary apoplexy. An urgent surgical decompression was carried out and necrotic haemorrhagic debris removed. Baseline bloods revealed non-pulsatile FSH of 40 U/l with LH 0.3 U/l with no hormonal response to GnRH administration, but the sequence of events strongly suggests a causal relationship between this and pituitary apoplexy. To our knowledge this is the first time that GnRH administration has been associated with pituitary apoplexy of a glycoprotein secreting pituitary adenoma.

Objective:To identify the cause of operative failure in patients who have undergone parathyroid surgery for primary hyperparathyroidism.Design:Retrospective case review.Participants:Patients who had undergone a primary procedure for primary hyperparathyroidism between July 2003 and December 2007. Cases with incomplete post-operative serum calcium data were excluded.Main outcome measure:Operative failure was defined as failure to achieve normalisation of serum adjusted calcium levels post-operatively.Results:A total of 220 primary procedures were conducted over 4.5 years. Data were not available for 16 patients. Thirteen procedures (6.4 per cent) were considered failures, and these cases were individually reviewed and classified according to the reason for failure.Conclusion:Establishing the cause of failure following surgery for primary hyperparathyroidism can be a complex task. In some instances, diagnostic uncertainty remains despite detailed biochemical and radiological assessment. This paper outlines our approach to maximising the cure rate at primary surgery. [ABSTRACT FROM PUBLISHER]