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Biomedical subjects

J Lubetzki

Publications and source records attributed to J Lubetzki.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1990

[Increase of circulating levels of thymulin in hyperprolactinemia and acromegaly].

The production of thymulin by the thymic epithelium is under complex control involving the endocrine system. Experimental models have suggested that prolactin (PRL) and growth hormone (GH) participate in this regulation but this has not been documented in humans. Using a bioassay we measured circulating thymulin levels in patients with hyperprolactinemia (n = 21), acromegaly (n = 15), or both (n = 6). Thymulin was elevated in these three groups of patients compared with normal subjects or with patients with pituitary disease but no excess in PRL or GH. Contrasting with observations in control groups, thymulin did not decrease as a function of age in patients. No correlation between thymulin and PRL or GH levels was observed while thymulin and insulin-like growth factor 1 levels were correlated. A new radioimmunoassay used in some patients for thymulin determination yielded similar results. Overall these data demonstrate that PRL and GH are involved in the hormonal control of thymulin production by the thymic epithelium in the human.

Acromegaly↗
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

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

Creatinine clearance evaluation in routine diabetes practice.

Creatinine clearance measurement based on timed urine collection is not reliable in routine practice. Methods for creatinine clearance estimation have already been established and validated in non diabetic patients. In order to ascertain their validity in diabetic patients, creatinine clearance values were determined in 33 diabetic patients (16 men, 17 women) on two consecutive days by direct measurement and by estimation according to the methods of Kampmann et al., Bjornsson et al. and Cockcroft and Gault. A good correlation (r = 0.73-0.75, p less than 0.001) was observed between measured and estimated creatinine clearance values. The correlation coefficients were stronger in men than in women. The day to day coefficient of variation was poor for creatinine clearance direct measurements (28%) and better for creatinine clearance estimation values (about 17%). These results suggest that methods for creatinine clearance estimation are suitable in diabetic patients for routine clinical practice.

Creatinine↗
PubMed1987

[Mixed endocrine tumor of the pancreas (vipoma, glucagonoma). Treatment by somatostatin followed by one of its long-acting analogs].

We describe the 4-year follow-up of an endocrine tumour of the pancreas (vipoma-glucagonoma) treated with chemotherapy. To control the endocrine syndrome we used somatostatin 14 by continuous subcutaneous infusion for 1 year, followed by the somatostatin analogue SMS 201-995 administered alone without antitumoral chemotherapy. Under SMS 201-995 (100 micrograms 12-hourly) the endocrine syndrome dramatically improved. This effect persisted for 12 months after which a relative resistance to the drug developed. It was necessary to increase the dosage (300-400 micrograms/24 hours) and to alter the mode of administration (continuous subcutaneous infusion) to obtain a clinical benefit inferior to that obtained during the first year of treatment with SMS 201-995. At present this drug is given combined with recombinant interferon alpha 2A. In spite of computerized tomography, ultrasonography and monitoring of hormone levels we were unable to determine whether or not SMS 201-995 exerted a partial antitumoral effect.

Adenoma, Islet Cell↗
PubMed1987

Androgen producing adrenal adenoma. Report on a case associated with hyperparathyroidism.

In a 41-year-old hirsute woman, severe hypercalcemia led to the discovery of hyperparathyroidism related to the involvement (hyperplasia/or adenoma) of the 4 parathyroid glands. Plasma and urinary DHA, plasma DHA-sulfate and delta 5 steroid precursors were elevated. Steroid hormone hypersecretion was stimulated by hCG and ACTH, and exhibited a paradoxical rise during dexamethasone administration. Computerized tomography scanning as well as arteriography disclosed bilateral adrenal hyperplasia and left adrenal adenoma. Bilateral adrenal vein catheterization indicated a left/right gradient for delta 5 steroids and delta 5 steroid sulfates. At surgery a left brown adrenal encapsulated adenoma was removed with a hyperplastic adrenal gland. Results of in vitro studies (adrenal steroid content and incubation) together with postadrenalectomy hormonal results suggest that the left brown adrenal adenoma was the main source of excessive androgen production. The infrequent association of an androgen-producing adrenal adenoma with hyperparathyroidism raises the hypothesis of multiple endocrine neoplasia syndrome. However, evidence for this diagnosis is lacking in the absence of other glandular involvement and of family history.

Adenoma↗
PubMed1987

The effect of subcutaneous infusion versus subcutaneous injections of a somatostatin analogue (SMS 201-995) on the diurnal GH profile in acromegaly.

Multiple sc injections of a long-acting somatostatin analogue (SMS 201-995) are currently used in the treatment of acromegaly. However, plasma GH concentration often reaches a pathological level (less than 5 micrograms/l) between two injections. In seven patients with active acromegaly we compared, in a short-term trial, the effect of SMS 201-995 administered by continuous sc infusion (50 micrograms and 100 micrograms a day) and by three sc injections (100 micrograms each). In six patients, plasma GH levels were significantly reduced regardless of the mode and dose of treatment (P less than 0.05). However, comparing diurnal profiles, 100 micrograms continuous sc infusion was more effective than discontinuous administration in reducing the number of GH levels above 5 micrograms/l (P less than 0.01). In two patients, continuous infusion was the only way to decrease all plasma GH values below 5 micrograms/l during the diurnal profile determination. Moreover, even when, in a long-term study, the dose of multiple injections was progressively increased to 500 micrograms three times a day, GH levels remained consistently elevated in one of these patients. Thus, in some acromegalic patients continuous sc injection seems currently the most efficient way of treatment with SMS 201-995.

Acromegaly↗
PubMed1987

[Biological detection of hormonal overdose in treated peripheral thyroid insufficiency. Comparison of ultrasensitive TSH and the TRH tests. Therapeutic consequences].

Fifty-two patients with peripheral hypothyroidism receiving hormone replacement therapy at conventional dosages and having normal free thyroid hormone levels underwent a TRH test (200 micrograms). This test was found areactive (delta TSH less than 4.0 microU/ml) indicating therapeutic overdosage in 38 cases (73 p. 100). It was possible to reestablish reactivity to the TRH test in 20 of these patients by progressively reducing the dosage to an average of 70 p. 100 of the initial dose. This reduction had no effects on body weight, heart rate or serum lipids. These results show that the plasma concentrations of thyroid hormones are poor indicators of overdose and underline the limitations of the concept of group normality to which that of individual normality is to be preferred. The treatment of hypothyroidism is much easier to adapt using the TSH test. Since the introduction of ultrasensitive methods of assaying this hormone the value of the TRH test has been questioned. We have defined the limits beyond which the TRH test is of no value and the basal TSH dosage adequate. There remains a zone (basal TSH between 0.15 and 1.00 microU/ml in our laboratory) within which the result of the TRH test cannot automatically be deduced from that of the basal TSH.

Adult↗