Serum creatine, creatinine, and other guanidino compounds in patients with thyroid dysfunction

Serum levels of creatine (CT), creatinine (CTN), urea, guanidinosuccinic acid (GSA), guanidinoacetic acid (GAA), guanidine (G), arginine (Arg), homoarginine (Harg), argininic acid (ArgA), and alpha-keto-delta-guanidinovaleric acid (alpha-K-delta-GVA) were measured in 54 patients with hyperthyroidism, 56 with subclinical hyperthyroidism, 28 with subclinical hypothyroidism, and 51 with hypothyroidism compared with 62 euthyroid controls. In agreement with previous reports, serum CT increased (+35%) and CTN decreased (-17.6%) in hyperthyroidism as compared with normal thyroid function, whereas the opposite was seen in hypothyroidism (-17.7% and +11%, P < .0001). Original findings from this study are a highly significant decrease in GSA (-41.7%) and GAA (-36.8%) in hyperthyroidism and an increase in GSA (+36%) in hypothyroidism (P < .0001). In addition, a slight decrease in hyperthyroidism and hypothyroidism was noted for Arg (-6.2% and -13.2%, P = .001) and Harg (-14.8% and -18.1%, P = .05). By contrast, no significant change was seen in levels of urea, G, ArgA, and alpha-K-delta-GVA. No major differences were found for any of the compounds between subclinical hypothyroidism, euthyroidism, and subclinical hyperthyroidism. There was a highly significant positive linear correlation between urea and GSA levels in hyperthyroidism, euthyroidism, and hypothyroidism (r = .68, r = .77, and r = .75, P < .0001), taking into account that for the same increase in urea, GSA increased threefold more in hypothyroid versus hyperthyroid patients. In conclusion, apart from CT and CTN, significant changes can be found in serum levels of GSA, GAA, Arg, and Harg in patients with thyroid dysfunction. Subclinical thyroid dysfunction does not seem to induce changes in serum levels of guanidino compounds. Decreased serum GSA and GAA levels might be an additional indicator of hyperthyroidism.

125I-Tyr0-hCRH labelling characteristics of corticotropin-releasing hormone receptors: differences between normal and adenomatous corticotrophs

The presence of corticotropin-releasing hormone (CRH) receptors has been previously demonstrated in corticotrophs from normal pituitaries using a method combining immunocytochemistry and liquid emulsion autoradiography. The aim of this study was to compare the characteristics of the 125I-Tyr0-hCRH binding in corticotrophs from normal pituitaries (three obtained at autopsy and one obtained at surgery) with corticotrophs from pituitary adenomas (six corticotroph adenomas responsible for Cushing's disease and two silent corticotroph adenomas secreting a biologically inactive ACTH molecule). In normal corticotrophs, the larger part of the 125I-Tyr0-hCRH binding was localised in patchy conglomerates at the centre of the cell and, to a much lesser degree, in a diffuse pattern at the cell periphery. In adenomatous corticotrophs, CRH receptor expression is disturbed both quantitatively and qualitatively. Except for a minority of cells in one adenoma, all adenomatous corticotrophs showed only peripherally bound 125I-Tyr0-hCRH and no centrally localised binding. Furthermore, adenomatous corticotrophs revealed a statistically significant lower signal intensity when compared to normal corticotrophs and a strongly negative correlation was found between the labelling area in adenomatous corticotrophs and both the basal and CRH-stimulated plasma ACTH levels. These findings suggest defective processing of CRH receptors and could be relevant to the sustained ACTH secretion by adenomatous corticotrophs in Cushing's disease and, more generally, provide an explanation to its pathology. The silent corticotrophs secreting a biologically inactive ACTH molecule were characterised by a very faint signal intensity, although present on almost every cell.

Thyrotoxic periodic paralysis, an unusual cause of hypokalemic periodic paralysis

Over a two-year period two patients were admitted to the hospital with episodes of paralysis and hypokalemia. In the first patient, familial hypokalemic periodic paralysis was initially suspected. Only several months later was Graves' disease diagnosed and this diagnosis linked to thyrotoxic periodic paralysis. The second patient came to notice after treatment with thyreostatic drugs was stopped prematurely and paralysis together with hypokalemia developed. Thyrotoxic periodic paralysis, being rare outside Asia, closely mimics the clinical presentation of familial hypokalemic periodic paralysis. Mainly men in the third decade with a negative family history are affected. Graves' disease is the most common cause of hyperthyroidism. This disorder is not always clinically apparent since signs of hyperthyroidism may be easily missed. Therefore thyroid function tests are part of the diagnostic workup of hypokalemic periodic paralysis. Correction of thyroid function is essential to treatment. The pathophysiology is still controversial.

The effect of naloxone and metoclopramide on the secretion of luteinizing hormone in a hyperprolactinemic hypogonadotropic postmenopausal woman

OBJECTIVE

To determine the role of opioidergic and dopaminergic activity in the suppression of GnRH0LH in a hyperprolactinemic state.

DESIGN

Case report.

SETTING

University hospital.

PATIENT

A 68-year-old woman with a macroprolactinoma.

INTERVENTIONS

Serial 10-hour IV infusions of naloxone and metoclopramide.

MAIN OUTCOME MEASURE

Serum LH concentration.

RESULTS

Naloxone induced a small but significant rise of serum LH levels, which displayed a pulsatile pattern. By contrast, metoclopramide elicited no significant response in LH secretion.

CONCLUSION

Opioidergic but not dopaminergic neurotransmission plays a direct role in the suppression of LH secondary to hyperprolactinemia.

Factitious hypoglycaemia documented by a modified assay for the measurement of plasma sulphonylurea

Two cases of factitious hypoglycaemia due to intentional or inadvertent intake of glipizide by non-diabetic subjects were identified through the measurement of this sulphonylurea in plasma by a modified assay procedure.

Pituitary metastasis mimicking a pituitary adenoma. A description of two cases

The cases of two elderly women treated for temporal hemianopsia due to a large pituitary mass with suprasellar extension are presented. In both cases, the clinical picture, without diabetes insipidus and cranial nerve paralysis, as well the neuroimaging and endocrinological investigation showing hypopituitarism, were suggestive of a non-secreting pituitary adenoma. In the first patient malignant tissue was unexpectedly encountered during transsphenoidal surgery. Anatomopathological investigation confirmed the presence of a metastasis of a breast carcinoma for which she had been treated 17 years earlier. In the second patient, a preoperative chest X-ray before transsphenoidal surgery revealed an asymptomatic bronchial tumour. Subsequently a squamous cell carcinoma with a metastasis in the pituitary was confirmed. These two cases illustrate the fact that a pituitary metastasis can closely mimic a pituitary adenoma. Even in the absence of suggestive symptoms such as diabetes insipidus and/or cranial nerve paralysis the possibility of metastatic disease in the differential diagnosis of a pituitary mass should always be considered.

Endocrine profiles during administration of the new non-steroidal anti-androgen Casodex in prostate cancer

OBJECTIVE

Casodex (Zeneca) is a new potent, long-acting non-steroidal anti-androgen, which produces androgen deprivation by blocking the androgen receptor. We evaluated the endocrine effects of Casodex 150 mg daily given in monotherapy as primary treatment for patients with prostate cancer.

DESIGN

As part of a large, multicentre study comparing the therapeutic effects of surgical castration with 150 mg/day Casodex in monotherapy for patients with prostate cancer, a subgroup of 23 patients on Casodex were studied in detail for changes in endocrine parameters. Serum levels of LH, FSH, testosterone, DHT, oestradiol, prolactin, sex hormone binding globulin and free testosterone were measured at the start of therapy and after 1, 4, 8, 12 and 24 weeks. Effects on libido, sexual activity and the appearance of hot flushes, breast pain and gynaecomastia were recorded.

RESULTS

Administration of Casodex resulted in a rise in LH levels in all patients with a mean increase after 24 weeks of 102% (P < 0.001). Mean FSH levels showed a limited increase (7%) after 24 weeks, which was significant only after 1 week (P < 0.001). As a result of the high LH levels, total testosterone levels increased after 24 weeks by 66% (P < 0.001), free testosterone by 57% (P < 0.001) and dihydrotestosterone by 24% (P = 0.0112). Parallel to testosterone, oestradiol levels rose by a mean of 66% (P < 0.001). Mean sex hormone binding globulin and prolactin levels rose by respectively 8% (P = NS) and 65% (P < 0.01). Despite an increase in testosterone levels, excellent androgen blockade was obtained, as shown by a decrease in prostate specific antigen levels in 22/23 patients. Libido was maintained in 8/11 patients, and sexual activity in 5/6. No patient complained of hot flushes. However, mild gynaecomastia and/or breast tenderness were seen in 48 and 30% of cases respectively.

CONCLUSION

Casodex 150 mg/day monotherapy resembles surgical castration in achieving androgen deprivation, despite an increase in LH and testosterone levels. In contrast to castration, libido and sexual activity are usually maintained and hot flushes are rare. However, mild gynaecomastia and/or breast tenderness were noted in 48 and 30% of patients.

Octreotide in advanced prostatic cancer relapsing under hormonal treatment

Since somatostatin analogues have been shown to possess inhibitory activity on prostatic cancer cells in animal models, we studied the clinical effects of the long-acting somatostatin analogue octreotide in the treatment of advanced prostatic cancer. Five patients with metastatic prostatic cancer in relapse under hormonal treatment and with rapidly increasing levels of prostate specific antigen (PSA) received a subcutaneous infusion of octreotide in a dose of 400 to 1,000 micrograms/day for a period of 2 to 6 months. Patients were followed clinically and by monthly measurement of PSA levels. During treatment 3/5 patients showed a temporary halt in rising PSA levels, while another patient had a small decrease. This inhibitory effect however was lost after 1 to 3 months of therapy in 3 patients. The remaining patient died after 4 months before an escape of PSA levels was seen. Side effects consisted of mild diarrhoea in three patients. From this very preliminary data, it appears that octreotide in a dose of 400 to 1,000 micrograms/day may give only a moderate and temporary inhibition of tumor growth in patients with advanced prostatic cancer. Because of the limited effects the study was interrupted prematurely. Since higher doses, other somatostatin-analogues or the combination of LHRH analogues may give better results, further studies are needed to determine the potential therapeutic role of somatostatin-analogues in this group of patients.

Glucose metabolism in a patient with hyperthyroidism and an insulinoma

A 67-year-old woman was admitted in hypoglycemic coma, with fever and signs of hyperthyroidism. Diagnosis was made of both an insulinoma and subacute ("De Quervain") thyroiditis. This rare coincidence of two diseases with opposite effects on serum glucose levels, offered a rare opportunity to study glucose metabolism in this peculiar physiopathological situation. During the day abnormally high postprandial blood glucose levels were seen, pointing to the glucose intolerance usually seen in the hyperthyroid state. During the night and after prolonged fasting, however, hypoglycemia predominated, consistent with the clinical picture typical of an insulinoma. After resection of the insulinoma and spontaneous healing of hyperthyroidism, glucose metabolism reverted to normal. As shown in this case, concurrent hyperthyroidism and an insulinoma may lead to consecutive episodes of glucose intolerance and hypoglycemia within the same 24-hour period.

Hyperfunctioning unilateral adrenal macronodule in three patients with Cushing's disease: hormonal and imaging characterization

We aimed to investigate the dynamics of adrenocorticotropin (ACTH) and cortisol secretion in pituitary-dependent Cushing's syndrome with bilateral macronodular adrenal hyperplasia presenting as a single adrenal macronodule, and to determine the imaging characteristics of this syndrome. Three female patients were studied. Plasma ACTH and serum cortisol secretion were studied by determining their rhythmicity and pulsatility and their responses to the administration of ovine corticotropin-releasing factor, thyrotropin-releasing hormone, metyrapone, tetracosactrin, insulin and dexamethasone. Techniques used to localize the anatomical lesion were bilateral simultaneous inferior petrosal sinus sampling, magnetic resonance examination of the pituitary, computed tomography (CT) scanning and [75Se]cholesterol scintigraphy of the adrenal glands. Plasma ACTH and serum cortisol levels were measured using a commercial radioimmunoassay and an immunoradiometric assay. The ACTH and cortisol pulse number and amplitude were calculated using established computer software. In all three patients ACTH and cortisol secretory dynamics fulfilled the requirements for diagnosis of pituitary-dependent Cushing's syndrome. A close relationship between ACTH and cortisol pulses also favored a pituitary dependency. Study of the amplitude of cortisol pulses classified two patients in the group of hypopulsatile Cushing's disease. Adrenal CT scanning demonstrated the presence of a large single nodule. [75Se]Cholesterol scintigraphy showed bilateral radionuclide uptake, although mostly localized over the adrenal nodule. All patients underwent successful trans-sphenoidal hypophysectomy. Over a period of 1 year, a slow shrinkage of the adrenal nodule was observed in two patients, while no change in volume was observed in one patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and endocrine effects of laser vaporization in patients with polycystic ovarian disease

Responses to laparoscopic ovarian laser vaporization were studied in 17 anovulatory patients with clomiphene citrate-resistant polycystic ovarian disease (PCOD). Ovulatory cycles were obtained in 14 patients (82%). A total of 11 patients (65%) conceived within 1-8 months. Measurements of basal serum hormone levels before and after the procedure in 12 patients revealed a significant decline in testosterone, dihydrotestosterone and androstenedione. In addition, luteinizing hormone (LH) levels decreased, but not significantly. On the other hand estradiol levels slightly increased and a surge in luteal progesterone levels was noted. Serum levels of sex hormone binding globulin, prolactin, dehydroepiandrosterone (DHEA) sulfate, 17-OH-progesterone and follicle stimulating hormone (FSH) remained unchanged. These results suggest that ovarian laser vaporization is very useful when clomiphene citrate fails in PCOD, and has no risk of ovarian hyperstimulation syndrome or multiple gestation, which is frequently observed in ovulation induction with drugs. Most of the endocrine abnormalities associated with PCOD are corrected by the laser procedure.

Wolfram syndrome: a clinical study of two cases

Two unrelated patients with two different images of Wolfram (or 'DIDMOAD') syndrome are presented: a 19-year old woman suffering from all the important features of this syndrome, and a 38-year old man showing two major characteristics but several minor abnormalities. This syndrome should be considered in young diabetic patients with unexplained visual loss or with polyuria and polydipsia in the presence of adequate blood sugar control. An early diagnosis is important to prevent unnecessary diagnostic investigations.

Ketoconazole and liarozole in the treatment of advanced prostatic cancer

BACKGROUND

Ketoconazole, an imidazole derivative, is an orally active antifungal agent. In high doses (400 mg three times a day), it inhibits the biosynthesis of testicular and adrenal androgens and may therefore be useful for the treatment of hormone dependent diseases such as advanced prostatic cancer. Similarly, a new imidazole derivative, liarozole, was recently found to interfere with testicular and adrenal steroid biosynthesis in animals and healthy volunteers.

METHODS

The therapeutic and endocrine effects of ketoconazole and liarozole in patients with disseminated prostatic cancer are discussed, including data from the literature and personal experience.

RESULTS

Using high-dose ketoconazole, medical castration with the expected clinical response was achieved easily in previously untreated patients in all clinical series (personal data include seven patients). In patients with prostatic cancer who had relapses after castration, few objective remissions were achieved. By contrast, long-lasting subjective remissions, especially pain relief, were seen in more than half of the patients (personal data include 20 patients). Gastrointestinal intolerance, which was the main side effect, severely limits the routine use of the drug. Recently, the authors studied the effect of liarozole on adrenal steroid production in castrated patients whose disease was progressive after first-line treatment. Unlike ketoconazole therapy, adrenal androgen and cortisol levels were not modified. A Phase I-II trial was then done in 44 patients with metastatic prostatic cancer in clinical relapse. In patients with measurable disease, objective responses, including tumoral volume reduction, occurred in approximatively 30%. A prostate specific antigen reduction of 50% or more was noted in approximatively 50% of patients. Pain relief occurred in most patients. Mucocutaneous side effects were observed in most patients--dryness of the skin and onychomalacia. Raised tissue retinoic acid levels suggested a possible pathway by which this drug might exert its cytotoxic effects.

CONCLUSIONS

Ketoconazole in high doses is effective in first-line and second-line therapy for advanced prostatic cancer, but gastrointestinal side effects limit its routine use. Liarozole is a new imidazole that is also effective in second-line therapy for prostatic cancer and has fewer side effects. Unlike ketoconazole, its effect is not mediated by inhibition of steroid biosynthesis.

Transsphenoidal resection in Cushing's disease: undetectable serum cortisol as the definition of successful treatment

OBJECTIVE

We tested the hypothesis that in Cushing's disease, ACTH secretion from the normal pituitary surrounding an ACTH-secreting adenoma is inhibited and hence removal of the entire adenoma should result in an undetectable serum cortisol in the immediate post-operative period.

DESIGN

A retrospective study of patients undergoing transsphenoidal selective adenomectomy, hemi-hypophysectomy or total hypophysectomy for Cushing's disease at St Bartholomew's Hospital between 1985 and 1990.

PATIENTS

Forty-eight consecutive patients (33 women, mean age 43, range 7-69 years) undergoing transsphenoidal hypophysectomy for Cushing's disease. Ten patients who underwent a second operation were re-evaluated; the patients were followed for a median time of 40 months after operation (range 15-70).

MEASUREMENTS

Post-operatively, serum cortisol was measured daily at 0900 h. Serum TSH, T4, prolactin, LH, FSH, testosterone or oestradiol plus plasma and urine osmolality were measured.

RESULTS

After initial surgery, post-operative serum cortisol was undetectable (< 50 nmol/l) in 20 out of 48 patients (42%) and < 300 nmol/l in 32 out of 48 patients (67%). Re-exploration of the pituitary fossa in 10 patients found undetectable cortisol levels in 25 (52%) and levels < 300 nmol/l in 39 (81%) patients. Cushing's syndrome has not recurred, clinically or biochemically, in any patient in whom the post-operative cortisol was < 50 nmol/l. Post-operatively, hypothyroidism was present in 40% of patients and hypogonadism in 53% of men and 30% of premenopausal women. Diabetes insipidus, persisting for at least six months, occurred in 46% of patients.

CONCLUSIONS

Cushing's disease has not recurred in any patient with an undetectable serum cortisol (< 50 nmol/l) post-operatively. Serum cortisol should be regarded as a tumour marker in Cushing's disease and the aim of transsphenoidal hypophysectomy for Cushing's disease should be to render the immediate post-operative serum cortisol undetectable.

The association of meningioma and pituitary adenoma: report of seven cases and review of the literature

Seven patients with the co-occurrence of meningioma and pituitary adenoma are reported. Diagnosis was based on histological examination and if not available on MR imaging. Extensive review of the literature reveals only 18 other cases with this association if meningiomas appearing after radiation therapy for pituitary tumors are excluded. As in isolated meningiomas, the female-to-male ratio is high. A preponderance of perisellar meningiomas is apparent. Another distinct characteristic of this combination is not revealed, since no specific typing of the meningioma and no specific endocrine syndrome is uncovered. Two patients presented with multiple meningiomas, of which one showed two histologically different tumor types. The presence of other tumors in association with pituitary adenomas and meningiomas in our series is striking and could suggest a genetic dysregulation leading to the development of these tumors.

Failure of total hypophysectomy to remove intrasellar microadenoma in cushing's disease

The pathological findings are described of a female patient with persistent Cushing's disease after two unsuccessful transsphenoidal operations: a left transsphenoidal hemihypophysectomy followed by a total hypophysectomy 1 month later. The patient was finally cured by bilateral adrenalectomy but suddenly died of heart failure 4 months later. Postmortem examination did not show invasive ACTH-secreting tissue in the pituitary region or an ectopic ACTH-secreting tumor, as initially presumed. Instead, a very small corticotroph adenoma was located immediately under the diaphragm sellae at the left side. The reasons for surgical failure in Cushing's disease are discussed. As in our patient, a missed small intrasellar adenoma must not be excluded when "total" hypophysectomy fails to cure Cushing's disease.

Cushing's disease and hyperprolactinemia due to a mixed ACTH- and prolactin-secreting pituitary macroadenoma

A 36-year-old man with depression, Cushingoid features and hypogonadism was found to have simultaneous pituitary-dependent Cushing's disease and marked elevation of serum prolactin (PRL). CT-scan revealed a macroadenoma with suprasellar extension. Transphenoidal surgery cured the patient's Cushing's disease, but failed to correct his hyperprolactinemia, which was controlled by subsequent bromocriptine therapy. Immunostaining of the pituitary tumor was positive for PRL as well as for ACTH, and ACTH-related peptides beta-lipotropin and beta-endorphin in two distinct tumor cell lines. This pituitary tumor is one of the few mixed PRL- and ACTH-secreting tumors documented by immunostaining. It is the second reported in a macroadenoma, in which PRL-secreting tumoral cells are much more abundant than ACTH-secreting cells.

Hyperfunctioning metastatic follicular thyroid carcinoma in Pendred's syndrome

A 66-year-old woman with Pendred's syndrome underwent a partial thyroidectomy when she was 17 years old. At the age of 52 years, she had a second thyroid operation because of hyperthyroidism due to a toxic multinodular goiter with a mediastinal extension consisting of several separate nodules. Five years later a hyperfunctioning metastatic follicular carcinoma was diagnosed histologically. After treatment with radioactive iodine, the patient was well. To the authors' knowledge, this is the first description of a metastatic follicular thyroid carcinoma in Pendred's syndrome and the first report of hyperthyroidism occurring after malignant degeneration of a dyshormonogenetic goiter.

Calculation of half-life of carcinoembryonic antigen after lung tumour resection: a case report

Since little is known about carcinoembryonic antigen (CEA) half-life in humans, we followed changes in CEA levels after curative resection of a small bronchial adenocarcinoma in a 54 yr old man with an unusually high preoperative serum CEA level of 1,199 ng.ml-1. Serum CEA followed a four phase curve with an initial increase, attributed to release of CEA from the tumour, a rapid fall during four days (CEA half-life 3.2 days), a slower exponential decay to normal levels during almost three months (CEA half-life 11 days) and eventually maintenance of normal levels for 14 months. These results are consistent with data from animal experiments and a single report on CEA half-life in humans, but CEA half-life seems longer in man than in animals. This observation also suggests that a very high serum CEA level should not in itself preclude curative surgical resection of a primary bronchogenic carcinoma.

Calculation of half-life of carcinoembryonic antigen after lung tumour resection: a case report

Since little is known about carcinoembryonic antigen (CEA) half-life in humans, we followed changes in CEA levels after curative resection of a small bronchial adenocarcinoma in a 54 yr old man with an unusually high preoperative serum CEA level of 1,199 ng.ml-1. Serum CEA followed a four phase curve with an initial increase, attributed to release of CEA from the tumour, a rapid fall during four days (CEA half-life 3.2 days), a slower exponential decay to normal levels during almost three months (CEA half-life 11 days) and eventually maintenance of normal levels for 14 months. These results are consistent with data from animal experiments and a single report on CEA half-life in humans, but CEA half-life seems longer in man than in animals. This observation also suggests that a very high serum CEA level should not in itself preclude curative surgical resection of a primary bronchogenic carcinoma.

Prolactin and pituitary gonadotropin values and responses to acute luteinizing hormone-releasing hormone (LHRH) challenge in patients having long-term treatment with a depot LHRH analogue

Sixty patients with advanced prostatic carcinoma were treated with monthly subcutaneous injections of a depot formulation of goserelin, a luteinizing hormone-releasing hormone (LHRH) analogue (Zoladex, ICI Pharma, Destelbergen, Belgium). All patients were regularly evaluated with measurements of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), and prolactin (PRL) levels. In 15 patients among them who could be treated for more than 42 months, an LHRH stimulation test was performed at the end of each 28-day period and before the next administration of the depot formulation. A complete and maintained suppression of both T and LH levels was seen. FSH levels also decreased, but to a lesser extent than LH levels, and showed a small escape after reaching a minimum value after 1 month of therapy. The LHRH challenge after 42 months of therapy elicited no significant responses of LH and FSH levels. The PRL values showed a small decrease.