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Biomedical subjects

M E Molitch

Publications and source records attributed to M E Molitch.

At least 19 recordsLinked to original sources
PubMed1992

Octreotide treatment of acromegaly. A randomized, multicenter study.

OBJECTIVE: To determine the effects of the somatostatin analog, octreotide acetate, in patients with acromegaly. DESIGN: Double-blind, randomized trial. SETTING: Fourteen university-affiliated medical centers. PATIENTS: One hundred fifteen acromegalic patients, 70% of whom had persistent disease after pituitary surgery or radiotherapy. INTERVENTION: Subcutaneous octreotide, 100 micrograms, or placebo every 8 hours for 4 weeks. Four weeks after the end of treatment, patients were randomized to receive 100 or 250 micrograms octreotide subcutaneously every 8 hours for 6 months. RESULTS: After 2 weeks of treatment, a single 100-micrograms injection reduced mean serum growth hormone (GH) to 30% of the pretreatment concentration within 2 hours. The integrated mean GH level was reduced over 8 hours from 39 +/- 11 micrograms/L to 9 +/- 2 micrograms/L (P less than 0.001). Mean plasma insulin-like growth factor-1 (IGF-1) was reduced from 5100 +/- 400 U/L to 2400 +/- 400 U/L (P less than 0.001). After 6 months, the mean GH was reduced from 39 +/- 13 to 15 +/- 4 micrograms/L by 300 micrograms of octreotide and from 29 +/- 5 micrograms/L to 9 +/- 2 micrograms/L by 750 micrograms of octreotide daily. The mean IGF-1 concentration was suppressed to 2100 +/- 300 and 2500 +/- 400 U/L after 300 and 750 micrograms octreotide, respectively. Integrated mean GH levels were reduced to < 5 micrograms/L in 53% (95% CI, 39% to 67%) and 49% (CI, 35% to 63%), and IGF-1 levels were normal in 68% (CI, 54% to 82%) and 55% (CI, 40% to 70%) of patients receiving low- and high-dose octreotide, respectively. A substantial decrease in headache, amount of perspiration, joint pain, and finger circumference occurred in two thirds of the patients. The pituitary size was reduced in 19% (CI, 5% to 33%) and 37% (CI, 22% to 52%) of patients receiving 6 months of low- and high-dose octreotide, respectively. Ten percent and 13% of patients in each treatment group developed transient diarrhea; 10% and 14%, biliary sludge; and 6% and 18%, cholelithiasis, respectively. CONCLUSION: Octreotide effectively decreased GH and IGF-1 concentrations in 53% and 68% of patients, respectively. The higher dose resulted in increased frequency of tumor shrinkage but added no biochemical or clinical benefit.

Acromegaly↗
PubMed1992

Endocrine emergencies in pregnancy.

A number of endocrine conditions and emergencies have unique characteristics when present in the pregnant woman. Often the abnormal endocrine state affects both mother and fetus and the various diagnostic and therapeutic approaches have to be altered to avoid harming the fetus. Furthermore, the pregnant state itself may alter the natural course of the underlying endocrine condition. Prolactinomas may enlarge due to the hormonal milieu of pregnancy, causing mass effects and even apoplexy. Anticipation of this possibility and prompt recognition may prevent disastrous consequences. This stimulatory state may extend to the normal pituitary, resulting in Sheehan's syndrome. An acute form of Sheehan's may go unrecognized, leading to unnecessary maternal deaths. Autoimmune endocrine disorders may sometimes be exacerbated and at other times be ameliorated during pregnancy. Witness the development of lymphocytic hypophysitis during pregnancy, a condition best left alone if it can be diagnosed without surgery. Graves's disease usually improves during pregnancy but it may occasionally flare, resulting in potentially lethal thyroid storm. The various therapeutic alternatives for hyperthyroidism are very much affected by effects on the fetus. Cushing's syndrome has very bad consequences for the fetus and must be diagnosed and treated urgently, if not emergently. Phaeochromocytomas are always endocrine emergencies requiring urgent and sometimes emergent treatment. Hyperparathyroidism is usually mild, but severe hypercalcaemia can be a true endocrine emergency. Recognition of the interactions of these endocrine conditions and their specific treatments with the complicated maternal-fetal unit makes their diagnosis and treatment simultaneously both difficult and extremely rewarding.

Acute Disease↗
PubMed1992

Effects of calcium channel blockade with verapamil on the prolactin responses to TRH, L-dopa, and bromocriptine.

To determine the mechanisms by which calcium channel blockade with verapamil causes hyperprolactinemia, the authors investigated the effects of this blockade on the prolactin (PRL) responses to stimulation by thyrotropin releasing hormone (TRH) and inhibition by dopamine, using L-dopa and bromocriptine. Verapamil, given for 1 week at a dosage of 240 mg orally to eight healthy volunteers, induced a significant elevation of basal PRL levels (17.3 +/- 1.8 ng/ml to 30.9 +/- 4.3 ng/ml, p < 0.005). Verapamil also caused an increase in the PRL response to a TRH (100 micrograms). However, when the increased basal level was considered by calculating the area under the THR response curve and subtracting the basal values, this increase (1763.4 +/- 202.6 ng/ml.min to 2260.6 +/- 223.9 ng/ml.min) was not found to be statistically significant (p > 0.05). Verapamil had no effect on the basal or TRH-stimulated thyroid stimulating hormone levels. In these same volunteers, PRL levels decreased from 13.2 +/- 2.5 ng/ml to a nadir of 5.5 +/- 1.6 ng/ml in response to L-dopa. After 1 week of verapamil 240 mg, basal PRL levels were elevated to 21.5 +/- 3.1 ng/ml, then decreased to 8.2 +/- 1.8 ng/ml with L-dopa. The percentage decreased in PRL in response to L-dopa (60 +/- 5% versus 62 +/- 3%) were not significantly different (p > 0.05). Verapamil had no effect on the basal or L-dopa-stimulated growth hormone levels. Bromocriptine 2.5 mg given to five volunteers twice daily caused PRL levels to fall from 13.3 +/- 1.6 ng/ml to 5.0 +/- 0.9 ng/ml.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Low plasma growth hormone binding protein in IDDM.

Poorly controlled insulin-dependent diabetes mellitus (IDDM) is associated with elevated basal plasma growth hormone (GH), disproportionally low insulin-like growth factor I (IGF-I) levels, and impaired somatic growth. These derangements in the GH-IGF axis imply a state of GH resistance. The mechanism of GH resistance is unknown; it may involve a defect at the level of the GH receptor, unresponsiveness due to a postreceptor defect in GH action, or both. To investigate a potential receptor involvement, we measured plasma high-affinity GH-binding protein (GHBP), which represents a truncated GH receptor and may reflect GH receptor levels in tissues, in patients with IDDM, patients with non-insulin-dependent diabetes (NIDDM), and nondiabetic control subjects. Patients with IDDM had significantly lower plasma GHBP levels than either patients with NIDDM or nondiabetic control subjects (mean value 18.2 vs. 24.6 and 23.8% GH bound/ml plasma, respectively, P less than 0.001). This difference persisted when only lean patients (less than 115% ideal body wt) were included in the analysis. Basal plasma GH levels were significantly elevated in IDDM compared with either patients with NIDDM or nondiabetic control subjects (mean 6.9 vs. 2.1 and 2.0 micrograms/L, respectively, P less than 0.001), whereas IFG-I levels were not significantly different in IDDM and NIDDM. No correlations were found between levels of GHBP and HbA1, duration of diabetes, or plasma GH. GHBP and IGF-I levels were significantly correlated in NIDDM but not in IDDM. We conclude that IDDM is associated with low GHBP levels and that GH resistance found in this disorder may be mediated, at least in part, by a decrease in GH receptor levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Pathologic hyperprolactinemia.

Unlike other pituitary hormones, PRL is under tonic inhibition by the hypothalamus by way of the PRL inhibitory factor, dopamine. GAP and GABA may also be inhibitory. PRL-releasing factors include TRH and VIP and possibly others. Circulating PRL is predominantly monomeric, although some patients with hyperprolactinemia appear to have increased quantities of the less biologically active polymeric forms. PRL is secreted episodically, with an increase in the amplitude of the secretory pulses with sleep. A transitory increase also occurs in response to the protein component of meals. Basal PRL levels increase in response to the hormonal milieu of pregnancy, and suckling postpartum triggers PRL release. Pathologic increases of PRL owing to hypothalamic dysregulation occur with a variety of medications, including the neuroleptics, metoclopramide, antidepressants, methyldopa, reserpine and verapamil, abuse of opiates and cocaine, renal insufficiency, cirrhosis, hypothyroidism, adrenal insufficiency, neurogenic stimulation, and idiopathically. Hyperprolactinemia also may occur from structural lesions of the stalk and hypothalamus, which cause disinhibition with or without maintenance of PRF activity, ectopic neoplasm production, and, most commonly, from prolactinomas. Diagnostic testing consists of routine chemistry and thyroid testing and imaging with MRI or CT. Dopamine agonists are the treatment of choice of prolactinomas of all sizes. Transsphenoidal surgery is an alternative for the patient who does not respond to medical therapy or who wishes definitive tumor removal, realizing that long-term cure is achieved in only 50% to 60% of patients with microadenomas and a much lower number in those with macroadenomas. Radiotherapy is reserved for patients who do respond to either medical or surgical treatment. Patients wishing to become pregnant usually are treated with bromocriptine, although prepregnancy surgical debulking may be advisable for those with large macroadenomas to reduce problems with tumor enlargement.

Bromocriptine↗
PubMed1992

Clinical manifestations of acromegaly.

Acromegaly is an uncommon disorder and may present in a variety of ways, leading to considerable delay in diagnosis. Unlike other pituitary tumors, tumors associated with acromegaly tend to be fairly large in most patients. Thus, symptoms may be commonly due to the tumor mass as well as to hormone oversecretion. Mortality is two- to threefold increased due to cardiovascular, respiratory, and neoplastic causes. An increase in diabetes mellitus and hypertension may contribute to the first of these. Early treatment may reverse the diabetes, soft tissue changes, sleep apnea, cardiovascular disease, and neuromuscular disease. The effect of early treatment on neoplasia is unclear, and patients probably should continue to be screened, especially for colon neoplasia, even after appropriate therapy for the acromegaly. Hypopituitarism may be present initially as a result of tumor mass but may also develop as a result of ablative therapy.

Acromegaly↗
PubMed1990

The pituitary "incidentaloma".

PURPOSE: To review evidence related to sellar masses that might be found incidentally on various radiologic procedures, including their differential diagnosis and recommendations for their evaluation and treatment. DATA IDENTIFICATION: An English-language literature search using bibliographic reviews of textbooks and review articles. STUDY SELECTION: Articles were selected on the basis of providing data on the autopsy prevalence of sellar masses, the radiologic and endocrinologic evaluation of such masses, and the prognostic aspects of pituitary adenomas. DATA EXTRACTION: Twelve studies relating autopsy findings, 6 studies describing radiologic characteristics, and 26 articles reviewing various endocrine aspects of pituitary adenomas were evaluated. RESULTS OF DATA SYNTHESIS: Pituitary adenoma is the most common incidental sellar mass. Scanning techniques are of great importance in differentiating the pituitary adenoma from other mass lesions. Autopsy and radiologic studies suggest that microadenomas (less than 10 mm in diameter) may be present in 10% to 20% of the population but that macroadenomas (greater than 10 mm in diameter) are quite rare. Hormone oversecretion by an adenoma may be asymptomatic but, when present, is very helpful in the differential diagnosis. CONCLUSIONS: For adenomas found to be hypersecreting, therapy is as indicated for that specific tumor type. If there is no evidence of hormone oversecretion from microadenomas, we suggest a conservative approach with repeat scanning done at yearly intervals, initially, and subsequently less frequently. Macroadenomas, because they have already indicated some propensity for growth, should either be surgically removed or, if completely asymptomatic, followed closely with repeat scans at 6- to 12-month intervals.

Adenoma↗
PubMed1990

Endocrinology.

Explore the source record for details and available documents.

Endocrinology↗
PubMed1990

Treatment of prolactin-secreting pituitary macroadenomas with the long-acting non-ergot dopamine agonist CV 205-502.

STUDY OBJECTIVE: Evaluation of the effects of an experimental long-acting non-ergot dopamine agonist, CV 205-502, on serum prolactin, tumor size, gonadal function, visual abnormalities, and tolerability in patients with macroprolactinomas. DESIGN: Prospective, unblinded, dose escalation as needed. SETTING: Four university medical centers; patients referred for treatment. PATIENTS: Twenty-six hyperprolactinemic patients (prolactin greater than 150 micrograms/L) with a pituitary macroadenoma were treated for 24 weeks with CV 205-502 given once daily. MEASUREMENTS AND MAIN RESULTS: Serum prolactin was measured at regular intervals. Prolactin levels decreased in all patients during treatment (mean pretreatment level, 2051.7 +/- 1077 micrograms/L [+/- SE]; 24 weeks, 39.0 +/- 11.3 micrograms/L; P = 0.0001); normal prolactin levels were achieved in 15 (58%). Tumor size decreased in 21 of 26 patients and ranged from 6% to 67% (mean, 19.2% +/- 3.4%). Onset or return of regular menses occurred in 11 of 15 premenopausal women, accompanied by an increase in estradiol concentrations (pretreatment, 186.5 +/- 25.0 pmol/L; on treatment, 690.9 +/- 104.3 pmol/L; P = 0.0003). Serum testosterone increased in 6 of 8 men; sexual function improved in 5 of 7 with pretreatment abnormalities. Two patients with reversible visual abnormalities improved within 2 weeks of starting treatment. Side effects occurred in 11 patients and abated over 1 to 2 weeks or after the dose was reduced. There was no evidence of toxicity as indicated by serial serum chemistries, liver function tests, hematologic profiles, thyroxine levels, and electrocardiogram studies. CONCLUSIONS: CV 205-502 reverses hyperprolactinemia and promotes reduction in tumor size with reversal of visual abnormalities and restoration of gonadal function in most patients. This compound will probably be useful in treating prolactinomas.

Adenoma↗
PubMed1990

Unaltered drug metabolizing enzyme systems in type II diabetes mellitus before and during glyburide therapy.

Diabetes mellitus is associated with alterations in hepatic drug metabolizing enzyme activities in experimental animals. To determine whether Type II diabetes or glyburide affect hepatic drug metabolism, the authors used 13C-labeled aminopyrine and caffeine breath tests as in vivo probes of the hepatic cytochrome P450 and P(1)450 enzyme activities respectively in six subjects with Type II diabetes (4 women, 2 men). These subjects had been treated previously with diet, had an age range of 41-63 years, had a body mass index range of 24.1-43.3 kg/m2 and had a mean fasting plasma glucose of 14.6 +/- 1.2 mM and a mean hemoglobin A1c of 12.2 +/- 0.7%. These subjects did not drink alcohol or take drugs known to affect hepatic drug metabolism. The caffeine and aminopyrine breath tests (CBT, ABT) were performed sequentially while fasting before the start of glyburide treatment (5 mg daily) and at weekly intervals for 4 weeks. ABT and CBT values are expressed as cumulative percentage of dose exhaled through 2 hours. Before beginning glyburide, the mean ABT and CBT results were 10.2 +/- 0.7% and 4.2 +/- 0.7% respectively, well within the normal ranges for these tests (ABT 6.5-15%; CBT 2.5-10%). The ABT and CBT values remained unaltered during 4 weeks of glyburide therapy. However, FBS decreased to 10.2 +/- 1.1 mM and HbA1C to 10.1 +/- 0.8% by the end of drug treatment. Type II diabetes that is poorly controlled by diet alone is not associated with alterations of the hepatic drug metabolizing enzymes as judged by the caffeine and aminopyrine breath tests. Furthermore, glyburide does not induce or inhibit the drug metabolizing enzyme systems in the liver, thereby precluding drug-drug interactions of this type.

Adult↗
PubMed1990

Occurrence of intercapillary nodular glomerulosclerosis in the absence of glucose intolerance.

The case of a 58-year-old man with nephrotic syndrome and characteristic pathologic renal lesions of KW disease is presented. No evidence of diabetes was found by oral or intravenous glucose tolerance tests. The possibilities of light-chain disease, membranoproliferative form of glomerulonephritis, and amyloidosis were excluded by histochemistry and immunofluorescent microscopy.

Blood Glucose↗
PubMed1990

Effect of angiotensin-converting enzyme inhibition on pituitary hormone responses to insulin-induced hypoglycemia in humans.

Renin, angiotensin-II, and angiotensin-converting enzyme (ACE) have been found in the hypothalamus and pituitary in rats, and renin, angiotensinogen, and ACE have been found in human pituitary lactotrophs. To determine the physiological relevance of the renin-angiotensin system in the pituitary hormone response to stress in humans, we created significant inhibition of ACE by administering a clinically used dose (10 mg) of enalapril (E) 4 h before measuring the stress hormone responses to insulin-induced hypoglycemia. Eight fasting lean healthy males (aged 20-35 yr) were given either placebo (P) or E (10 mg, orally) in two studies separated by at least 5 days in a blinded study design. Glucose, ACTH, cortisol, PRL, and GH levels were measured before E or P and at 20-min intervals beginning 20 min before insulin administration. ACE levels were similar at baseline (E, 21.6 +/- 2.7; P, 22.4 +/- 2.4 mU/mL/min), but were significantly lower at the time of insulin injection with E treatment (E, 2.9 +/- 0.5; P, 20.9 +/- 2.5 mU/mL/min; P less than 0.001). The mean of the total area under the curve of PRL secretion was significantly lower for the E group (E, 3767.2 +/- 710.7; P, 4554.9 +/- 650.1 micrograms/L.min; P less than 0.05). Although the mean peak PRL levels were lower for the E group, this did not reach statistical significance (E, 53.0 +/- 9.7; P, 64.4 +/- 9.4 micrograms/L; 0.05 less than P less than 0.10). These differences in PRL responses appeared to be due primarily to substantial decreases in PRL responses with E in three of the eight subjects. No significant differences were found with ACTH, cortisol, or GH for basal levels, peak levels, or areas under the curve.

Adrenocorticotropic Hormone↗
PubMed1990

Inhibition of follicle-stimulating hormone secretion from gonadotroph adenomas by repetitive administration of a gonadotropin-releasing hormone antagonist.

As a preliminary step in searching for a pharmacological treatment for gonadotroph adenomas, we administered the GnRH antagonist analog Nal-Glu GnRH to five patients, four men and a woman, with FSH-secreting gonadotroph adenomas in order to determine its effect on FSH secretion. Administration of a single 10-mg dose of Nal-Glu GnRH to four of the patients produced a significant decrease in the serum FSH concentration in two patients and returned the FSH level to normal in only one. Administration of 5 mg Nal-Glu every 12 h for 7 days, however, produced a significant (P less than 0.001) decrease, and to within the normal range, in four of the five patients (mean +/- SEM, 32.7 +/- 5.6 IU/L during the 3 days before treatment and 9.8 +/- 1.4 IU/L during the last 3 days of treatment). Also, in response to the 7-day treatment, LH fell significantly in all five patients, alpha-subunit fell in three, and testosterone fell in all four men. Administration for 6 weeks of the GnRH agonist analog leuprolide did not decrease the serum FSH concentration of one of the patients whose serum FSH did decrease in response to Nal-Glu GnRH. We conclude that repetitive administration of Nal-Glu GnRH may often inhibit FSH secretion by gonadotroph adenomas and that FSH secretion by gonadotroph adenomas may be dependent on endogenous GnRH secretion.

Adenoma↗
PubMed1989

Management of prolactinomas.

Prolactinomas are the most common of the hormone-secreting pituitary tumors and must be distinguished from nonsecreting tumors causing hyperprolactinemia by hypothalamic or stalk dysfunction. For both micro- and macroadenomas, dopamine agonists appear to be the treatment of choice, transsphenoidal surgery being reserved for nonresponders. For women desiring pregnancy, dopamine agonists are safe when there is a microadenoma or an intrasellar macroadenoma. However, in women with large macroadenomas desiring pregnancy, limited transsphenoidal decompression followed by bromocriptine appears to be the safest mode of treatment.

Female↗
PubMed1989

CV 205-502 treatment of hyperprolactinemia.

CV 205-502 is a nonergot oral dopamine agonist with specific D2 activity, which has a prolonged suppressive effect on serum PRL and may have fewer side-effects than other dopamine agonists. We treated 26 hyperprolactinemic women with this compound given as a single bedtime (hs) dose for up to 12 weeks. All had gonadal dysfunction, either amenorrhea or oligomenorrhea, and 15 had galactorrhea. The initial and subsequent doses were administered in a randomized fashion; the initial dose ranged from 0.01-0.05 mg, and the dose at 12 weeks ranged from 0.03-0.09 mg. The women were evaluated every 2 weeks, and the dose was increased by 0.02 mg every 4 weeks if the serum PRL level was greater than 20 micrograms/L. Of the 26 women initially enrolled, 24 completed 12 weeks of therapy, and 2 discontinued therapy because of side-effects. Thirteen women (54%) had return of menses, and 12 (80%) had either a decrease in or disappearance of galactorrhea. Serum PRL concentrations decreased to a variable degree in all patients; 13 (54%) achieved a normal serum PRL level (less than or equal to 20 micrograms/L). The mean (+/- SE) pretreatment serum PRL concentration was 129 +/- 34, and it was 29.9 +/- 5.9 micrograms/L after 12 weeks of treatment (P = 0.005). The mean (+/- SE) percent reduction in serum PRL was 66.5 +/- 5.0% (median, 78.0%). A dose response was not demonstrated (r = -0.08; P = 0.70) among the 6 dose groups during the last 4 weeks of therapy. In 5 women, serum PRL levels, measured frequently for 24 h after treatment remained low. Side-effects after the initiation of therapy included nausea, headache, and morning fatigue in 10 women. These symptoms caused 2 women to discontinue therapy; they subsided in the other women. An optimal dose was not determined and will probably need to be determined by titration in each patient. CV 205-502, given once daily, appears to be a safe and effective alternative to other dopamine agonists in the treatment of hyperprolactinemia.

Amenorrhea↗