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Biomedical subjects

P Chanson

Publications and source records attributed to P Chanson.

At least 109 records · Page 6Linked to original sources
PubMed1990

Cardiovascular effects of the somatostatin analog octreotide in acromegaly.

OBJECTIVE: To determine the cardiovascular effects of the somatostatin analog octreotide in patients with acromegaly. DESIGN: Prospective nonrandomized study. SETTING: Referral-based endocrinology clinic. PATIENTS: Seven patients with active acromegaly, three of whom had refractory congestive heart failure. The other four patients were free of symptoms associated with heart failure. INTERVENTIONS: All patients were treated with octreotide, 100 to 500 micrograms subcutaneously three times daily. The three patients with heart failure continued to receive cardiovascular therapy (angiotensin converting enzyme inhibitors, digitalis, diuretics). MEASUREMENTS AND MAIN RESULTS: During octreotide therapy, patients showed a rapid decrease in growth hormone and insulin-like growth factor 1 (IGF-1): Mean levels (+/- SD) fell from 28.1 +/- 32.7 micrograms/L to 5.2 +/- 8.3 micrograms/L and 740 +/- 126 micrograms/L to 372 +/- 64 micrograms/L, respectively (P less than 0.025). Plasma volume returned to normal and heart rate decreased significantly. In the four patients without heart failure, right-heart catheterization done before and after 3 months of octreotide therapy showed an 18.3% +/- 11% reduction in stroke volume and a return to normal of the cardiac index. The three patients with congestive heart failure, evaluated before and after 40 days and up to 2 years of therapy, showed a dramatic clinical improvement that was associated with an increase in stroke volume (by 24% to 51%). In these patients, the cardiac index remained in the normal range, filling pressures were markedly decreased, and pulmonary wedge pressure returned to normal. This improvement was sustained for up to 3 years in the two patients with heart failure who were receiving long-term treatment. CONCLUSION: The rapid and sustained cardiac improvement seen in our patients shows that octreotide therapy for patients with acromegaly may be highly beneficial, even in those patients with advanced cardiac failure.

Acromegaly↗
PubMed1990

Atrial natriuretic factor in patients with acromegaly.

In acromegaly the plasma volume is chronically elevated and it returns to normal when the disease is successfully treated. To define the role of ANF in such a chronic disorder of extracellular fluid volume homeostasis the plasma level was assayed in 37 acromegalic patients with active or inactive (successfully treated) disease. Five patients were studied before and after therapy. The effects of acute change in sodium-fluid status on plasma ANF levels was examined in 7 active and 4 inactive acromegalic patients and in 7 healthy subjects. As compared to 14 patients with inactive acromegaly, 23 patients with active acromegaly had an expanded plasma volume (n = 12; 50.1 vs 37.6 ml.kg-1 BW) and an increased blood concentration of growth hormone (n = 23; 22.5 vs 2.1 ng.ml-1). Plasma ANF concentrations in active and inactive acromegalic patients (33.2 and 26.6 pg.ml-1, respectively) did not differ significantly from one another or from the level in the controls (26.9 pg.ml-1). In those patients there was no correlation between plasma volume and ANF level. Infusion of 21 isotonic saline in 2 h led to a similar, significant increase in ANF levels in active (from 26.2 to 72.4 pg.ml-1) and in inactive acromegalic patients (from 33.6 to 96.7 pg.ml-1) as well as in healthy subjects (from 21 to 70.6 pg.ml-1). Successful treatment reduced the plasma volume (from 49.2 to 35.8 ml.kg-1 BW) and growth hormone level (from 10.1 to 2.6 pg.ml-1), while the ANF level remained unchanged (from 33.8 to 35.5 pg.ml-1).(ABSTRACT TRUNCATED AT 250 WORDS)

Acromegaly↗
PubMed1990

Pituitary granuloma and pyoderma gangrenosum.

Pyoderma gangrenosum is a rare chronic and recurrent skin disease characterized by progressing lesions from papulopustules to large necrotic sterile ulcers. Its definite etiology remains unknown. In a 40-year-old woman with typical pyoderma gangrenosum an intrasellar mass with suprasellar extension was diagnosed and removed by transsphenoidal surgery. Histopathological features of the lesion were those of a nonspecific granulomatous hypophysitis. Five months postoperatively the patient experienced visual defects and hypopituitarism demonstrated by endocrine evaluation. Computerized tomography showed the recurrence of the intrasellar expanding mass. Extensive and repeated evaluation failed to find any evidence of sarcoidosis, tuberculosis or histiocytosis. Corticosteroid therapy was preferred to surgery and 80 mg daily prednisone produced a dramatic shrinkage of the pituitary pseudotumor. Long-term follow-up studies did not disclose any recurrence of the pituitary granulomatous process nor objective evidence of underlying disease even after steroid dosage has been tapered. The hypothesis of a pituitary localization of pyoderma gangrenosum is suggested by the similarity between the histopathologic findings of the two conditions and the excellent response to steroid therapy.

Adult↗
PubMed1990

Comparison of HbA1 and fructosamine in diagnosis of glucose-tolerance abnormalities.

Total glycosylated hemoglobin (HbA1) and fructosamine were evaluated as screening tools for detection of glucose-tolerance abnormalities in 144 asymptomatic subjects undergoing a 75-g oral glucose tolerance test. Subjects were classified according to World Health Organization criteria as having normal (n = 78), impaired (n = 40), or diabetic (n = 26) glucose tolerance. We found good specificity for HbA1 and fructosamine (100 and 97%, respectively) but low sensitivity (15 and 19%, respectively). At the intersection of the curves of sensitivity and specificity drawn from various thresholds of normality, both sensitivity and specificity were 75% for HbA1 and 55% for fructosamine. Thus, neither HbA1 nor fructosamine seems to be suitable for the diagnosis of mild abnormalities in glucose tolerance.

Blood Glucose↗
PubMed1990

Comparison of fructosamine with glycated hemoglobin as an index of glycemic control in diabetic patients.

Fasting and postprandial (or post-glucose load) plasma glucose, total HbA1 and fructosamine (F) were simultaneously assessed in 371 diabetic patients (125 insulin dependent and 246 non-insulin dependent) and in 122 nondiabetic subjects, (98 with normal glucose tolerance and 24 with impaired glucose tolerance). Fructosamine yielded nearly similar information as HbA1 about glycemic control, since similar relationships were observed between plasma glucose values and HbA1 or fructosamine levels in the different groups. A longitudinal study performed during a three-month follow-up in 74 diabetic patients and extended to six months in 19 of them, without any modification of treatment, indicated that reproducibility of HbA1 and fructosamine was nearly the same with a slight advantage for HbA1. The only clinically significant difference results from the longer half-life of hemoglobin when compared to serum proteins. Fructosamine assay should be proposed as a complement of HbA1 in the management of diabetic patients when detection of recent metabolic changes is needed.

Adult↗
PubMed1989

Platelet-derived growth factor (PDGF) in type 1 diabetes mellitus.

In 10 patients with type 1 diabetes mellitus, platelet-derived growth factor (PDGF) was assessed using an in vitro assay based on the stimulation of DNA synthesis in the 3T3 mouse fibroblast cell line. beta-Thromboglobulin (beta-TG) was used as an index for platelet alpha-granules content. Platelet beta-TG content and PDGF were markedly decreased in diabetic patients while plasma beta-TG was increased as compared with control subjects. In diabetic patients, a significant negative correlation was found between plasma beta-TG level and beta-TG total platelet content, associated with a significant positive correlation between platelet beta-TG content and PDGF. These results suggest that PDGF release might be increased in diabetic subjects. This may account in part for the cell proliferation observed in diabetic angiopathy.

Adult↗
PubMed1989

Experience of a six-month treatment with sandostatin at increasing doses in acromegaly.

The French Sandostatin/Acromegaly Study Group performed a multicentric, prospective, open-label trial of incremental doses with the aim of obtaining the best antisecretory effect. Forty-two patients (24 women, 18 men) aged 22-71 years were involved, either after unsuccessful surgery and/or radiotherapy (30 patients), or as primary treatment (12 patients). Doses were increased from 3 x 100 to 3 x 500 micrograms/day, according to the results of hormonal investigations (GH profiles and Sm-C) performed each month and for each dose, and tolerability. Four patients dropped out because of major digestive troubles. Recurrent pain at the injection site and minor gastrointestinal disorders were noted in some patients. Asymptomatic gallstones appeared in 4 patients. Carbohydrate tolerance and insulin secretion (determined by diurnal plasma glucose and insulin profiles) were not significantly altered by the various SMS doses. Clinical improvement was determined by the scoring of the symptoms. Mean plasma GH concentrations were significantly reduced for each SMS dose, compared to pretreatment values. Fifteen patients obtained 75% of GH values less than or equal to 2 micrograms/l. In 9 patients the highest dose failed to bring GH below 10 micrograms/l. Sm-C normalized in 17/31 patients. After 6 months of treatment a tumor reduction of 20-50% was found in 7 patients and greater than 50% in 5 patients. We conclude that (1) the tolerability of SMS is compatible with long-term treatments; (2) clinical improvement and biological criteria of efficacy are obtained in 3/4 acromegalic patients treated by SMS, and that (3) some patients are resistant to SMS and the increase in the dose does not improve the result.

Acromegaly↗
PubMed1989

Treatment of hyperthyroidism due to inappropriate secretion of thyrotropin with the somatostatin analog SMS 201-995.

The management of hyperthyroidism due to inappropriate secretion of TSH (IST) includes agents that selectively suppress TSH hypersecretion both in patients with TSH-secreting tumor [neoplastic IST (nIST)] in whom pituitary surgery was unsuccessful and in those with selective pituitary resistance to thyroid hormone action [nonneoplastic IST (nnIST)]. Among such agents, somatostatin administration has proven to be effective in blocking TSH hypersecretion, but its short plasma half-life prevented its use in long term therapeutic trials. The recent availability of a potent and long-acting analog of somatostatin (SMS 201-995, Sandostatin) prompted us to study its effects on serum TSH, alpha-subunit, and free thyroid hormone (FT4 and FT3) concentrations in five patients with nIST and three patients with nnIST. During short term SMS 201-995 administration (100 micrograms, sc, three times daily for 5 days) both serum TSH and alpha-subunit levels decreased in all patients with nIST (mean decrements, -86% and -85%, respectively), with concomitant normalization of serum FT4 and FT3 concentrations. In the three patients with nnIST, this treatment lowered serum TSH levels less well (mean decrement, -47%), although serum FT4 and FT3 levels normalized in one patient. Chronic SMS 201-995 (100 micrograms, sc, every 12 h for 1-7 months) treatment in four hyperthyroid patients (two with nIST and two with nnIST) resulted in a steady euthyroid state in both patients with nIST, with restoration of normal visual fields in one patient. In contrast, in both patients with nnIST, escape occurred after 2 weeks of therapy. We conclude that SMS 201-995 administration is effective treatment for patients with nIST, able to suppress TSH hypersecretion from the adenomatous thyrotrophs and, consequently, to restore clinical and biochemical euthyroidism in such patients. On the contrary, the inhibitory effects of SMS 201-995 on TSH secretion in patients with nnIST are weaker and transient.

Adult↗
PubMed1989

The effect of somatostatin analogue on chiasmal dysfunction from pituitary macroadenomas.

The long-acting somatostatin analogue SMS 201-995 has been shown to be efficient in the treatment of somatotropic and thyrotropic adenomas. In some cases, it can suppress adenoma secretion and lead to tumor shrinkage. Pituitary macroadenomas are often associated with a vision-threatening chiasmal syndrome. In this series, SMS 201-995 was administered subcutaneously to eight patients with pituitary macroadenomas of various types responsible for severe long-lasting visual defects. An obvious improvement of both visual fields and acuity occurred in six patients, in two of these during the first 4 to 6 hours of treatment; in two patients, gonadotropic adenomas were unresponsive. Maximal improvement (normalization of visual fields in three cases) occurred within 6 to 45 days and was sustained during the 1- to 12-month follow-up period. This effect seems independent of the type of adenoma since the adenomas secreting growth hormone (GH) and thyroid-stimulating hormone and silent corticotropic-secreting adenomas responded as well as did two of the non-functioning adenomas. In one acromegalic patient visual improvement was obtained while the abnormal GH secretion remained unaltered. In all cases but one, no tumor shrinkage could be demonstrated. These data demonstrate that SMS 201-995 can rapidly improve the chiasmal syndrome due to pituitary macroadenoma, and suggest that this effect might be independent of a reduction in tumor volume.

Adenoma↗
PubMed1988

[Treatment of post-neurosurgical diabetes insipidus with desmopressin by intramuscular route].

Desmopressin (DDAVP) is used intramuscularly in the treatment of post operative diabetes insipidus as soon as the condition is diagnosed to ensure continuous replacement of antidiuretic hormone secretion during the first 5 days of therapy. Two successive studies, each involving 15 patients, were conducted. The first study was designed to test the effectiveness and detect the possible side effects of intramuscular DDAVP, while the purpose of the second study was to evaluate the clinical application of the drug. With seven 2 mcg doses of DDAVP, administered 12-hourly by intramuscular injection to patients weighing more than 30 kg, continuous antidiuresis during 96 hours was achieved. This method is simple and effective, but it should not be prolonged beyond that period of time. Moreover, to prevent plasma hypo-osmolality, fluid intake must be strictly controlled and kept at the same level as or below diuresis.

Adolescent↗