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Biomedical subjects

G Paoli

Publications and source records attributed to G Paoli.

42 records · Page 3Linked to original sources

Platelet aggregation and thromboxane A2 production after adrenergic stimulation in young healthy humans.

The effects of adrenergic stimulation on platelet aggregation (platelet aggregation ratio; PAR), beta-thromboglobulin (beta-TG) release and plasma thromboxane B2 (TxB2) levels were investigated in 25 healthy young volunteers. Adrenergic stimulation induced by cold application was checked by evaluating the changes in the calculated vascular resistance in the forearm. A prompt increase in platelet aggregates and plasma beta-TG and TxB2 concentrations was observed after adrenergic stimulation. PAR changed from resting values of 0.97 +/- 0.05 to 0.75 +/- 0.08 (p less than 0.001) at the end of cold application. At the same time, beta-TG plasma concentration increased from 32.09 +/- 19.64 to 135.48 +/- 37.97 ng/ml (p less than 0.001) and TxB2 plasma levels changed from 0.49 +/- 0.24 to 0.99 +/- 0.39 pmol/ml (p less than 0.001). TxB2 levels, but not PAR and beta-TG concentration came back to the resting values at the end of the observation period (10 min). Aspirin, as the lysine acetylsalicylate equivalent to 5 mg/kg i.v. of acetylsalicylic acid, although able to completely inhibit platelet cyclooxygenase failed to inhibit the plasma TxB2 increase induced by adrenergic stimulation. This strongly suggests that the increase in plasma TxB2 following adrenergic stimulation is of extraplatelet origin. Also beta-TG and PAR changes were not affected by aspirin administration.

Adolescent↗

Ethnogenomic diversity of Caucasus, Daghestan.

Autosomal short-tandem repeats (STRs) were typed in ethnic populations of Kubachians, Dargins, Avars, Lezgins, Kumiks, and Nogais of the Caucasus (Daghestan, Russia) at the University of Utah. Daghestan ethnic populations demonstrated differences in STR allele frequency distributions, but these differences were much lower among these ethnic groups compared to worldwide ethnic groups. The observed genetic diversity was low while F(ST) values were high, both of which provided supporting evidence for small population sizes and high levels of isolation among the ethnic groups. An analysis of genetic distance from the three major continents, encompassing Daghestan populations and groups, reveals three distinct clusters: all populations of African affiliation, European and Daghestan populations except the Nogais, and Asian populations with ethnic Nogais.

Dagestan↗

Antihypertensive action of nifedipine: effects on arteries and veins.

Nifedipine is a calcium-channel antagonist with effective antihypertensive activity and has been suggested for the treatment of high blood pressure as an alternative to vasodilators. The aim of this study was to define the acute effect of nifedipine and in particular the dose-effect relationship, effects on veins, influence on adrenergic reflexes, and effectiveness on hypertension according to severity and etiologic type. The effects of nifedipine on blood pressure, heart rate, forearm blood flow, peripheral vascular resistance, orthostatic and cold reflexes, and venous tone were examined in 45 patients with hypertension of different etiologies (essential, renovascular, and renal parenchymal) and different World Health Organization grades. The antihypertensive effect was dose dependent, but a dose of 20 mg has nearly maximal activity with acceptable side effects. The drug acts by lowering peripheral vascular resistance, and this lowering is directly related to baseline values; therefore, the antihypertensive effect increases with severity of the hypertension. Nifedipine had the same effect in all three etiologic groups of hypertension studied. The drug seems to increase venous tone, since it caused venoconstriction when locally injected in hand veins. Nifedipine did not alter adrenergic reflexes induced by both cold application and standing and was well tolerated. In conclusion, the calcium antagonist nifedipine for its characteristics of action, at least in acute administration, seems to be a useful alternative in the treatment of various forms of hypertension.

Adult↗

Genetic structure in the Garfagnana (Tuscany, Italy): a study of eight protein markers by isoelectric focusing.

The genetic structure of the human population in a random sample of 238 unrelated individuals from Garfagnana (Tuscany, Italy) was studied for five highly polymorphic serum proteins (GC, TF, PI, AHSG, ORM1) and three red cell isozymes (ACP, PGM1, ESD) by isoelectric focusing. Comparison with the gene frequencies from other districts of Tuscany has shown no significant deviation in seven out of eight polymorphic protein systems. Subtype allele frequencies of orosomucoid 1 (ORM1), which were not yet determined in Italian populations, are as follow: ORM1*F1 = 0.586, ORM1*F2 = 0.021, and ORM1*S = 0.393. The most striking features of this unique sample were the relatively high frequencies of PGM1*2B (0.093) and PI*I (0.013) alleles.

Alleles↗

Introducing quality assurance in radiotherapy.

Introducing a Quality Assurance methodology appears particularly useful in Radiation Oncology due to the complexity of the procedures involved and the heterogeneity of the standards adopted, if any, in the great majority of the Centers. There are two possible ways of evaluating quality in the Health Environment: a formal, Institutional certification, or a voluntary one obtained through a mechanism of peer review. The European Society for Therapeutic Radiology and Oncology (ESTRO) started in 1994 with the publication of a methodological Report intended to be adopted by the individual national Societies, and this paper is an invitation to do it.

Humans↗