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Biomedical subjects

R Rossi

Publications and source records attributed to R Rossi.

At least 487 records · Page 27Linked to original sources
PubMed1980

Electrophoretic pattern of polypeptide synthesis in spermatocytes and spermatids of the mouse.

The pattern of protein synthesis in different stages of spermatogenesis was examined using two-dimensional polyacrylamide gel electrophoresis followed fluorography. The [3H]leucine labelling was performed by incubating in culture either seminiferous tubules before cell separation or isolated germ cells after fractionation by velocity sedimentation at unit gravity in an albumin gradient. The patterns of soluble polypeptides synthesised in middle-late pachytene spermatocytes, round spermatides (steps 1--8 of spermiogenesis) and intermediate spermatids (steps 9--13) have been compared with each other. Approximately 250 fluorographic spots were detected in middle-late pachytene spermatocytes and round spermatids, but only 100 in intermediate spermatids. From the analysis of fluorograms in the three cell stages examined, 5 categories of labelled polypeptides can be identified: (1) those specific of each cell stage; (2) those present in pachytene spermatocytes and early spermatids but absent in intermediate spermatids; (3) polypeptides labelled during spermiogenesis but unlabelled in meiotic cells; (4) polypeptides showing quantitative differences among the three cell types; and finally (5) polypeptides common to the three cell stages. These results are discussed in relation to differential gene expression during spermatogenesis.

Animals↗
PubMed1980

Altered glucoregulatory response to physiological infusions of epinephrine and glucagon in hyperthyroidism.

To study the mechanism of altered glucose homeostasis in hyperthyroidism, the effects of a 2-h physiological infusion of epinephrine (0.05 microgram/kg x min) or glucagon (3 ng/kg x min) on glucose kinetics and glucoregulatory hormones were determined in nine normal subjects and five untreated hyperthyroid patients. Under basal conditions, hyperthyroid patients exhibited increased glucose turnover (2.2 +/- 0.09 vs. 1.62 +/- 0.1 mg/kg x min in normals), a modest hyperglycemia, hyperglucagonemia, and normal levels of plasma insulin, cortisol, and GH. In normal subjects, epinephrine induced a sustained increase in plasma glucose (45 mg/dl), reflecting a transient 100% rise in glucose output, and a sustained 28% decrease in glucose clearance. In hyperthyroid patients, the rise in plasma glucose was significantly lower (22 mg/dl) due to a smaller but sustained increase in glucose output (45%) and the lack of a fall in glucose clearance. Plasma insulin rose to a peak 80% higher than baseline in hyperthyroid patients, whereas in normals it initially declined and then rose to levels 50% higher than basal. Plasma glucagon displayed only minor changes in both groups. Glucagon infusion induced similar increments in plasma glucagon levels in the two groups (120-150 pg/ml). Insulin, cortisol, and GH remained unchanged. Plasma glucose rose by 4 mg/dl in hyperthyroid patients and by 11 mg/dl in normal subjects. The net increments were significantly lower in the former group (P < 0.05-0.01). Glucose output increased by 40% in normals and returned to baseline by 75 min, whereas it increased by only 15% in hyperthyroid patients and remained above baseline until the end of the infusion. Glucagon had no appreciable effect on glucose clearance in either group. We conclude that hyperthyroidism is characterized by 1) increased glucose turnover and hyperglucagonemia in the basal state, 2) a reduced glucemic response to physiological infusions of epinephrine and glucagon, 3) a sustained response of glucose production to epinephrine and glucagon, and 4) the lack of epinephrine-induced suppression of glucose clearance, presumably due to an exaggerated response of insulin secretion to epinephrine.

Adult↗
PubMed1980

[Protein, immunological and "Gc", "Gm" and "Inv" picture in high-risk mastectomized subjects].

In the field of research on cancer we studied 294 women of which 142 who had undergone mastectomy, 70 selected for a high risk group, 82 normal. In order to determine some parameters who characterize the three groups we research for each the globulin factor Gc, Gm, and Inv, the proteic fractions and the immunoglobulins, as already pointed out by other investigators. The study of data points out results some times not according to previous reports. Comparing people who had undergone mastectomy and who had been selected for a high risk group, on the bases of GC phenotype together with immunoglobulins we obtained interesting values that characterize and delimit the two groups.

Alpha-Globulins↗
PubMed1980

A new case of human Y chromosome with satellites on the long arm.

A Y chromosome with satellites at the end of the long arm is reported. The banding techniques RBG, GTC, C and N were used. C-banding revealed a reduction of the heterochromatic part of the chromosome. The pedigree of the family didn't show any pathological feature in the carriers of this morphological variation. The frequency of satellite association was also studied.

Abnormalities, Multiple↗
PubMed1980

[Influence of the gastric acidity on the digoxinemia. Comparison between digoxin and beta-methyldigoxin (author's transl)].

In a medium term study, carried out according to a random cross-over schema, the Authors have evaluated the influence of gastric acidity on the digoxinemia, after the administration of digoxin (0.375 mg/day) and beta-methyldigoxin (0.25 mg/day) from the same batches. The results confirmed the effect of the gastric acidity on cardiac glycosides and an higher stability of beta-methyldigoxin than digoxin. These data suggest that digoxin, particularly in patients with gastric hypoacidity, must be used cautiously, because we can reach decidedly dangerous haematic levels, with a mean deviation of the values from the normal subjects of 89%, in comparison with 18% in the beta-methyldigoxin treated patients.

Aged↗
PubMed1979

Neurocutaneous syndromes and retroperitoneal tumors.

A patient with multiple basal cell carcinoma syndrome, a symptom complex characteristized by nevoid basal cell carcinomas of the skin, jaw cysts, skeletal abnormalities, and hyporesponsiveness to parathormone is presented. In addition, the patient had a retroperitoneal lymphagiomyoma, a hamartomatous lesion, causing ureteral obstruction. The association of neuroectodermic syndromes and retroperitoneal and intra-abdominal tumors is reviewed.

Adult↗
PubMed1978

Base composition changes in hepatocyte nuclei DNA of rats at different ages.

DNA extracted from isolated hepatic nuclei of rats at different aged (1 h, 6 and 30 days of life) has been characterized by (i) melting temperature, (ii) buoyant density, (iii) thermal denaturation on hydroxyapatite and (iv) nucleoside composition. The melting midpoint (Tm) determined spectrophotometrically in 0.1 X SSC (0.15 M NaCl/0.0015 M sodium citrate) is 71.9 +/- 0.4 for 1-h-old rats and decreases to 70.7 +/- 0.3 in 6-day-old animals. The buoyant densities of DNAs determined by CsCl on both native and alkaline-denaturated and reneutralized DNA were also found to decrease with age. Hydroxyapatite thermal denaturation of sonicated DNA confirmed the significant difference between the Tm values of 1-h-old and 6-day-old rats (86.5 +/- 0.5 and 85.2 +/- 0.1, respectively). The possibility that these differences in Tm values could be due to an increase in methyl bases, has been ruled out by the finding that the amount of [3H]methyl incorporated in relation to the DNA synthesis is constant at these two ages. The alternative possibility of a change in base composition has been tested by the chromatographic analysis of nucleosides. The dG + dC content is 0.433 +/- 0.003 in 1-h-old rats and decreases to 0.411 +/- 0.002 and to 0.403 +/- 0.005 in 6-day- and 30-day-old rats, respectively. The physiological significance of the different base composition is discussed in relation to the possibility that specific DNA sequences are synthesized during the non-premitotic synthesis which has been found to take place during the first 6 days of life.

Aging↗