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Biomedical subjects

R Vigneri

Publications and source records attributed to R Vigneri.

At least 199 records · Page 11Linked to original sources

Epidemiology and clinical characteristics of endemic cretinism in Sicily.

In this study we report the prevalence of endemic cretinism in the general population of two iodine deficient areas in Northeastern Sicily that were described more than 10 yr ago. In addition, the individual characteristics of endemic cretins are considered in order to define the typical expressions of this major iodine deficiency disorder in Sicily. Forty-three mental defectives were identified: 22 were living in an area with three bordering and closely connected municipalities within the province of Messina and with a population of 17,485 inhabitants (prevalence = 0.13%). Three out of the 22 were school-age children. The other community, in the province of Catania, was constituted by a unique and mostly agricultural hamlet, and showed a prevalence of cretinism that was 0.68% (21/3,100). Among the 43 mental defectives, 16 (37%) presented prominent neuromotor and neurosensorial disorders, including deafmutism and were euthyroid, thus conforming to the neurological type of cretinism; 13 (30%) were hypothyroid and exhibited stunted growth without significant neuromotor and neurosensorial impairment (myxedematous cretins). In the remaining 14 individuals (33%) neurological disorders were associated with stunted growth and clinical or biochemical hypothyroidism. These data indicate that also in Sicily endemic cretinism is a continuum of a variety of forms: among these the pure neurological and pure myxedematous forms represent the two extremes. Our observations also indicate that endemic cretinism still represents a major public health problem in Sicily. The finding of 3 endemic cretins younger than 13 yr suggests the persistence of this disorder even in the presence of improved economic, social and nutritional conditions.

Adolescent↗

Cytogenetic analysis in congenital hypothyroidism.

In order to evaluate the possible role of genetic factors in the pathogenesis of congenital hypothyroidism (CH), we investigated the occurrence of chromosome aberrations in a consecutive series of 47 patients with CH and 208 matched healthy controls. No abnormal karyotype was found in CH patients. In 5 CH patients and in 3 healthy controls a number of heterochromatin variants was detected. Although chromosomal variants are devoid of phenotypic effects, the frequency of these variants was higher in CH patients than in the control group (10.6% vs 1.4%, p less than 0.005). These findings suggest that the association of congenital hypothyroidism with chromosomal variants may reflect more than chance concurrence.

Chromosome Aberrations↗

Endemic cretinism in Sicily.

This work reports the presence of endemic cretinism in a small district located inside an endemic goiter area in north-eastern Sicily, personally described. The study covers 19 mental defectives (11 females and 8 males, mean age 35.8 +/- 15.5 yr) selected on the basis of severe mental retardation recognized by the local doctors. No systematic survey for cretinism was carried out in the total population. Marked mental retardation was evident in all subjects. Nine of them exhibited clinical and biochemical signs of hypothyroidism (myxedematous cretins). The 10 others were clinically euthyroid and had deaf-mutism and/or pyramidal tract dysfunction (neurological cretinism). Familial aggregation of cretinism was also observed. In both myxedematous and neurological cretins and urinary iodine excretion was very low, but not significantly different from that recorded in the euthyroid controls of the same area. The data available do not clarify the pathogenesis of endemic cretinism in Sicily. However, the marked height retardation, the observation of delayed bone maturation and the severity of mental deficiency suggest that thyroid failure was present in early life. The presence of endemic cretinism today in Sicily constitutes a strong argument in favour of the immediate introduction of adequate iodine prophylaxis.

Adolescent↗

Role of metformin in treatment of diabetes mellitus.

Metformin, a biguanide antidiabetic agent that can be administered either alone or in combination with sulfonylureas, has been extensively used in Europe and Canada. The mechanism of action of metformin and other biguanides is not completely understood, but recent in vitro and in vivo studies suggest that metformin may act in part by both increasing the binding of insulin to its receptor and potentiating insulin action. Metformin, because of its chemical structure, does not interact with the liver and has a short half-life. Consequently, lactic acidosis, which is a rare complication of metformin, has not been associated with the proper use of this drug. In addition to its antidiabetic actions, metformin causes weight loss in obese diabetic patients and may be useful in managing associated lipid disorders.

Acidosis, Lactic↗

[Receptor status and ovarian function in carcinoma of the breast].

The Authors have evaluated the relationship between the presence of estrogen (ER) and progesterone (PgR) receptors and the ovarian function in 321 consecutive and unselected women who have undergone surgery for breast cancer. A significant relationship was found between the presence and the concentration of steroid receptors (ER and PgR) in the neoplastic tissue and the ovarian function. The Authors confirm the importance of considering the menopausal status in the evaluation of the results of steroid receptor assay.

Adult↗

Metformin and insulin receptors.

We evaluated the effect of metformin (N,N-dimethylbiguanide), a biguanide known to be less toxic than phenformin, on insulin binding to its receptors, both in vitro and in vivo. Specific 125I-insulin binding to cultured IM-9 human lymphocytes and MCF-7 human breast cancer cells was determined after preincubation with metformin. Specific 125I-insulin binding to circulating monocytes was also evaluated in six controls, eight obese subjects, and six obese type II diabetic patients before and after a short-term treatment with metformin (850 mg orally, b.i.d., for 4 days). Plasma insulin levels and blood glucose were also measured on both occasions. Metformin significantly increased insulin binding in vitro to both IM-9 lymphocytes and MCF-7 cells; the maximum increment was 47.1% and 38.0%, respectively. Metformin treatment significantly increased insulin binding in vivo to monocytes of obese subjects (+ 31%, P less than 0.05) and diabetic patients (+ 63%, P less than 0.01). Scatchard analysis indicated that the increased binding was mainly due to an increase in receptor capacity. Insulin binding to monocytes of normal controls was unchanged after metformin as were insulin levels in all groups; blood glucose was significantly reduced after metformin only in diabetic patients. These data indicate that metformin increases insulin binding to its receptors in vitro and in vivo. The effect in vivo is observed in obese subjects and in obese type II diabetic patients, paralleling the clinical effectiveness of this antidiabetic agent, and is not due to receptor regulation by circulating insulin, since no variation in insulin levels was recorded. By this mechanism, therefore, metformin may contribute to restoring insulin effectiveness in subjects with impaired insulin responsiveness.

Blood Glucose↗