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Biomedical subjects

V Balestra

Publications and source records attributed to V Balestra.

At least 19 recordsLinked to original sources
PubMed1995

Behavior of soluble HLA class I antigens in patients with chronic hepatitis C during interferon therapy: an early predictor marker of response?

Soluble HLA class I antigens (sHLA-I), beta 2-microglobulin (beta 2-mu) and alanine aminotransferase (ALT) serum levels have been evaluated in 16 patients affected by chronic hepatitis C treated for six months with recombinant interferon-alpha (rIFN-alpha, 3 MU three times a week). The predictor role of sHLA-I and ALT modifications with respect to the response to rIFN-alpha therapy was also evaluated. Six patients responded (group 1), five patients relapsed followed in initial responses (group 2), and five did not respond to rIFN-alpha treatment (group 3). The baseline serum levels of sHLA-I and beta 2-mu were significantly higher in all three groups of HCV-positive patients with respect to HCV-negative controls (P < 0.05). A significant increase of sHLA-I serum level with respect to baseline value (P < 0.001) was observed in group 1 patients after two weeks of rIFN-alpha treatment. sHLA-I serum level then decreased, although remaining steadily and significantly increased with respect to baseline (P values ranging from 0.05 to 0.01) in the following five months and then returned to baseline one month after the end of rIFN-alpha administration. No significant variations of beta 2-mu serum levels were detected throughout the observation period. In group 1 patients ALT serum levels significantly decreased after two weeks of rIFN-alpha treatment (P < 0.001) and then remained in the normal range throughout the observation period. In the other two groups of patients no relevant variations of sHLA-I and beta 2-mu serum levels were found during and after rIFN-alpha therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Assessment of growth hormone insulin like growth factor-I axis in Down's syndrome.

As GH therapy has been reported to increase growth velocity in children with Down's syndrome (DS), we studied the GH-IGF-I axis in some DS patients affected by growth retardation without serious congenital malformation, malnutrition or pathological thyroid or adrenal function. IGF-I and IGF-II were evaluated in 39 patients in basal conditions. The patients were subsequently divided into two groups with respect to the IGF-I basal value: Group 1 (GR 1) consisting of patients with abnormally low basal IGF-I concentration as compared to age matched control subjects, group 2 (GR 2) consisting of patients with IGF-I in the normal range. In 6 GR 1 patients and 12 GR 2 patients we evaluated GH and IGF-I concentrations after stimulation with arginine (0.5 g/kg bw), and recombinant GH (4 IU im). In the same patients, GH radioreceptor assay and serum GH-binding protein were evaluated. In all patients IGF-II proved normal (534 +/- 23 ng/ml; mean +/- SE), while IGF-I was pathological in 36% of subjects. The cause of the defective IGF-I secretion in these patients does not seem to depend on an impaired GH axis, as no significant difference in arginine-stimulated GH peak values was seen between GR 1 (29.6 +/- 5.3 ng/ml) and GR 2 (15.1 +/- 2.24 ng/ml). IGF-I concentration evaluated 12, 24, and 48 h after arginine stimulation was significantly increased only in GR 2 patients (peak value: 0.95 +/- 0.1, p = 0.0003 vs baseline; GR 1: 0.34 +/- 0.05 U/ml).(ABSTRACT TRUNCATED AT 250 WORDS)

Carrier Proteins↗
PubMed1993

Human flash-VEP and quantitative EEG are independently affected by acute scopolamine.

Scopolamine in acute intramuscular doses of 0.25-0.75 mg reduced the P2-N3 flash-VEP amplitude and, in the quantitative EEG, the 8.5-12.0 Hz power and total power in 8 healthy young male volunteers. The effects on flash-VEP and EEG total power were dose dependent and were evident 30 min and 90 min respectively after drug administration, regardless of dose. The reduction in 8.5-12.0 Hz power was limited to the 0.50 and 0.75 mg doses. No systematic effects on the pattern-VEP were observed. Possible interferences with flash- or pattern-VEP amplitude of the scopolamine-induced EEG changes were identified and removed by regression analysis and computation of VEP residuals from the regression function. The P2-N3 flash-VEP residuals proved EEG independent and showed relationships with dose and time after drug administration that were superimposable on those of the original data, with comparable significance levels at the drug/placebo and pre/postdrug statistical comparisons. The results indicate that VEP estimates of drug effects which are independent from EEG changes can be identified in human studies and allow some inference on the cholinergic specificity of the systems affecting late flash-VEP components. The statistical approach used in this study is suitable for application in VEP studies when effects of interacting factors are to be expected.

Adult↗
PubMed1993

Ammonia-independent modifications of the background EEG signal and paradoxical enhancement of epileptic abnormalities in EEG after acute administration of valproate to epileptic patients.

The effects on the background quantitative EEG (power spectral analysis) and concentration of valproate in plasma were studied after single-dose (14.3-33.3 mg/kg) oral administration in 12 epileptic patients with generalized nonconvulsive or partial seizures. An increase of the amplitude of the background EEG (diffuse and preponderant on anterior scalp areas) and a decrease of the 12.5-32.0 Hz relative power (limited to the posterior electrode deviations) were observed; the increase in the EEG total power was paralleled by a definite increment in incidence of epileptic phenomena in the EEG. Both effects proved unrelated to shifts in vigilance or changes in the concentration of ammonia or serum glucose in plasma and confirm previous observations from superimposable study designs. These findings are qualitatively opposite to those observed during long-term treatment at comparable doses and are suggested to reflect a direct CNS action of acute administration of valproate.

Adolescent↗
PubMed1992

Placebo effects in standard human neuropharmacological studies: effects of physiological variations of blood glucose and ammonia concentration on the electrophysiology of the visual system.

The effects on retinal and cortical visual evoked phenomena of the stimulus intensity/spatial frequency and of the spontaneous, physiological blood glucose/ammonia fluctuations were investigated comparatively in a pilot study on young male volunteers. Flash ERG and flash OPs to 5 different stimulus intensities and pattern VECP to 3 spatial frequencies were recorded at 2-hour intervals during a standard acute pharmaco-EEG experimental session (8 h) with administration of placebo; glucose and ammonia blood concentration levels were assessed concomitantly. The effects of the stimulus intensity/spatial frequency were statistically defined for each amplitude/latency measure by nonlinear regression analysis and were removed by computing the residuals from the regression function, which were then tested separately versus the glucose/ammonia concentration by linear regression. Glucose/ammonia statistically significant effects on the visual system were detected at concentration levels within the range of normality and were representative of a nonnegligeable portion of the data overall variance. These effects were selective on retinal/cortical evoked phenomena and it is conceivable that physiological or pathological metabolic changes might account for a still underestimated source of individual variability in human neuropharmacological studies otherwise adequately controlled.

Adult↗
PubMed1991

The relative contribution of androgens and insulin in determining abdominal body fat distribution in premenopausal women.

To investigate the relative contribution of insulin and sex hormones in determining the abdominal pattern of fat distribution in premenopausal women, five groups of age-matched subjects were examined: Group 1 consisted of 14 normal weight eumenorrheic women (NO); Group 2 of 9 obese eumenorrheic women (OB); Group 3 of 14 normal weight hyperandrogenic women with polycystic ovary syndrome (NO-HA); Group 4 of 10 obese hyperandrogenic women with polycystic ovary syndrome (OB-HA) and, finally, Group 5 of 10 obese hyperandrogenic women with polycystic ovary syndrome and acanthosis nigricans (OB-HA-AN). Both the two normal weight groups and the three obese groups were matched for body mass index values. Sex hormone pattern showed significantly higher LH and testosterone levels in hyperandrogenic women with respect to NO and OB women but obese hyperandrogenic groups (OB-HA and OB-HA-AN) presented significantly lower LH concentrations than NO-HA. Fasting and glucose-stimulated insulin levels were significantly higher in OB than NO, in OB-HA and OB-HA-AN than in OB and NO-HA, and in OB-HA-AN than in OB-HA, without any significant difference between OB and NO-HA. Body fat distribution, expressed by the waist to hip ratio (WHR), showed progressively higher values (p less than 0.01) from NO to OB, NO-HA, OB-HA and, particularly, OB-HA-AN women. Determination coefficients r2 obtained from simple regression analysis showed that the sum of insulin values during the glucose tolerance test and testosterone levels had a more significant power in determining WHR variability.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1990

Ouham-Pendè: a new endemic goiter area in Centro-African Republic (C.A.R.). Preliminary observations on school children.

In this work, the Authors make several epidemiological observations and report a series of biohumoral data relative to a new endemic goiter area in the north-western region of the Centro-African Republic (CAR). In this province whose chief-town is Bocaranga, living conditions are very poor and primitive, manioca being the staple food. The survey was carried out in 11 rural schools and in 2 schools in the chief-town; 4009 subjects were examined; 2839 were males, 1170 females. The goiter prevalence observed in the whole sample population was 79.75%. The prevalence for each step of the grading were: 34.6% for 1a; 32.9% for 1b; and 11.8% for 2. In the schools of the chief town the goiter prevalence was found to be significantly lower than in the rural schools (71.9% versus 83.6% with P less than 0.01). Being the goitrous F/M ratio equal to 1.041, the goiter prevalences and gradings in females were higher and more severe than in males. After calculating these differences by means of the cumulated frequencies and the Kolmogorov Smirnov test, they were found to be significant. In 45 goitrous subjects, high TSH (7.19 microU/ml +/- 5.1), T3 (1.65 ng/ml +/- 0.56), and TG serum levels (410 ng/ml +/- 280) were found; however, low normal levels were observed for rT3 (8.97 ng/dl +/- 7.5) and fT4 (0.50 ng/ml +/- 0.51). In 42 casual urine samples, iodine excretion was 23.2 micrograms/l +/- 12.8; thyocianate excretion was 9.72 mg/l +/- 6 with a I/SCN ratio = 2.38.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Ouham-Pendé: a new endemic goiter area in the Centroafrican Republic (CAR): epidemiological survey on 7621 subjects.

The authors report epidemiological observations about a new endemic goiter area in the North western region of the Centro-African Republic (CAR). The research was carried out in 7 quarters of the chief-town (Bocaranga) and in 8 rural villages; 7621 people were examined by the same three of the present Authors who filled in a sample individual form (proposed by WHO) with the generalities and the goiter grading. The data were analyzed according to sex, age and place of residence by means of the common position parameters and the cumulative frequencies, taking into account the goiter grading of each group. The goiter prevalences observed in the rural areas varied from 70.9% (males) to 82.6% (females), whereas in the chief-town they varied from 29.3% (males) to 57.9% (females). Neurological and myxedematous cretins were seen to constitute 3.4% of the visited population. The M/F goitrous ratio was near unity under the age of 6; above this age, females are more widely and severely affected than males. An important fall in goiter prevalence was observed in adult males after the age of 16. The gradings observed in the rural villages, in both females and males of different ages (0-5; 6-15; 16-45; greater than 45 ys.) were significantly more severe than those observed in the chief town (P less than 0.01). The results obtained confirm those of a preliminary survey which the Authors previously carried out on a sample of school children living in the same region of CAR.

Adolescent↗
PubMed1989

Clinical and hormonal characteristics of obese amenorrheic hyperandrogenic women before and after weight loss.

We studied a group of obese hyperandrogenic amenorrheic women to determine the effects of weight loss on anthropometry, hormonal status, menstrual cycles, ovulation, and fertility. Fourteen women had polycystic ovaries, two the hyperandrogenism-insulin resistance-acanthosis nigricans syndrome, one hirsutism of adrenal origin, and three idiopathic chronic anovulation. The duration of amenorrhea before the study ranged from 3-17 months [mean, 8.6 +/- 4.5 (+/- SD)]. All women ate a hypocaloric diet for a period of 8.0 +/- 2.4 months. Weight loss ranged from 4.8 to 15.2 kg (mean, 9.7 +/- 3.1 kg; 1.35 +/- 0.56 kg/month) and the waist to hip ratio, which was used as a measurement of body fat distribution, decreased from 0.86 +/- 0.1 to 0.81 +/- 0.06 (P less than 0.0001). The women's mean plasma testosterone and LH concentrations decreased significantly (P less than 0.001 and P less than 0.005, respectively). A significant positive correlation was found between the decreases in plasma testosterone levels and the decreases in glucose-stimulated insulin levels. Moreover, the decreases in the waist to hip ratio correlated positively with the decreases in glucose-stimulated insulin levels and inversely with the decreases in plasma 17 beta-estradiol. No relationships were found between weight loss and the changes in plasma insulin, steroid, and gonadotropin concentrations. The responsiveness to the weight reduction program was evaluated by comparing the number of menstrual cycles during the study period with the number reported before it. Eight women had significantly improved menstrual cyclicity (responders), while 12 did not (nonresponders). The clinical characteristics and hormone values were similar in responder and nonresponder women. In the group as a whole, 33% of the menstrual cycles during the study were ovulatory, and 4 pregnancies occurred. Hirsutism improved significantly in more than half of the women, as did acanthosis nigricans when present. We conclude that weight loss is beneficial in all obese hyperandrogenic women regardless of the presence of polycystic ovaries, the degree of hyperandrogenism, and the degree and distribution of obesity.

Adult↗
PubMed1989

[Biometrico-statistical evaluation of a biological sample].

The total animal population percentage composition, found during period May-August 1979 on tunny-fishing coco-fibres nets in Camogli (Genoa), has been valued in relation to the depth. In particular, connections between population and presence of some fish species draughted has been studied, considering ecological, reproductive and trophic habits of fishes, in order to value relations between the influence these populations exert on fishing and biological characteristics of the quantitatively more meaningful fish species.

Animals↗
PubMed1989

[Percent composition of fatty acids in Tigriopus fulvus from rocky pools on the Ligurian coast (Copepoda harpacticoida)].

The study concerns the Tigriopus fulvus specimens fatty acid composition, sampled in Ligurian coast rockpools from September 1980 to June 1981. By the study of frequency distribution it was observed that the fatty acid found in greater quantity was the palmitic one, followed by the palmitoleic, the oleic and stearic acids. Short and long chain fatty acids are less frequent. Investigation about each fatty acid concentration shows that the seasonal trends between males and females are different and the trend of some fatty acids (e.g. linolenic and stearic acid) is characteristic.

Animals↗
PubMed1988

Long-term effects of ticlopidine on fibrinogen and haemorheology in patients with peripheral arterial disease.

The effects of ticlopidine treatment (250 mg b.i.d. for 21 months) on fibrinogen and other rheological variables, as compared to placebo, were studied in 44 patients with intermittent claudication due to peripheral arterial occlusive disease. Blood samples were collected every 3 months during this double-blind, randomised placebo-controlled trial which lasted 21 months. Consistently lower values of fibrinogen, haematocrit and whole blood viscosity at high and low shear rate levels were found in the ticlopidine group; the intergroup differences were statistically significant at most but not all follow-up examinations. A significant time-related variance was observed in the ticlopidine group for the measured variables, also after correction for the variability found in the placebo group. Thus, the observed changes in the ticlopidine group are mainly treatment related. These effects on fibrinogen and haemorheology may contribute, besides the known antiplatelet activity of the drug, to the clinical improvement reported in a larger group of claudicants to which the present subset of patients belong.

Blood Viscosity↗
PubMed1988

Weight loss and sex steroid metabolism in massively obese man.

To evaluate the effect of weight loss and diet therapy on plasma sex hormone behavior in male obesity, 9 men with a BMI of 43.4 +/- 6.3 participated in an 8-week semistarvation program [whose energy content ranged from 320 to 500 k calorie/day (proteins 44 to 60 g and carbohydrates 54 to 81 g per day)] followed by a two-week hypocaloric (1000 k calorie/day) refeeding. In basal conditions, obese patients presented higher estrogen and lower dehydroepiandrosterone sulphate, testosterone (total and free) and sex-hormone binding globulin concentrations with respect to a group of control normal-weight subjects. Cumulative weight loss was 23.9 +/- 3.6 kg after semistarvation and 24.4 +/- 4.8 kg after refeeding (p = NS). A significant increase in testosterone, free testosterone and dehydroepiandrosterone sulfate was observed throughout the study, irrespective of dietary intake. A transient increase occurred in estrone levels while 17B-estradiol did not change. Gonadotropins and sex-hormone binding globulin values remained unaltered. No relationship was found between sex hormones and dietary energy content or composition. Daily urine free cortisol, which was used as a parameter of adrenal function, fell approximately 50% during semistarvation but returned to baseline values after refeeding. These results show that in massively obese patients weight loss per se may partially reverse sex hormone abnormalities but not sex-hormone binding globulin concentrations. It remains to be determined whether the return to "normal weight" can normalize steroid metabolic derangements in the obese man.

Adult↗
PubMed1985

Quantitative EEG and neuropsychological effects of piracetam and of the association piracetam-lecithin in healthy volunteers.

The electroencephalographic (EEG) and neuropsychological effects of single, oral doses or piracetam (800-6,400 mg) and of its association with lecithin (4,800 mg and 25 g, respectively) were investigated in two groups of healthy volunteers in placebo-controlled studies. The EEG was quantified by power spectral analysis; both parametric and nonparametric procedures were applied to process the EEG and neuropsychological data statistically. The drug plasma concentration was assessed (gas chromatography) in concomitance with the EEG and neuropsychological measurements. Piracetam was found to elicit systematic EEG effects, namely a decrease in the low-frequency components and an increase in the power of the 8.5- to 12.0-Hz and of the fast-frequency components. The EEG modifications were restricted to the anterior scalp areas; its detection by means of parametric statistics was conditioned by the relevant individual variability and was inferred resting upon a number of criteria (indication at nonparametric tests, topography, consistency across subjects, replicability, etc). The correlation between EEG changes and drug plasma concentration was ambiguous, and the compound was not found to be effective on any of the neuropsychological variables considered. The study exemplifies some of the methodological problems in quantitative pharmaco-EEG and emphasizes the relevance of topography and replication.

Brain↗
PubMed1984

Comparison between the central effects of camazepam and temazepam. Computerized analysis of sleep recordings.

The effects of acute administration per os of 30 mg camazepam and the same dose of temazepam, were compared with placebo in 8 young male volunteers, fully adapted to the laboratory environment by 6 nights of adaptation. The study was double-blind, in a random order, 10 days separating each session. Spectral analysis was performed on the all-night records (1-min epochs), and the relative power of six frequency bands calculated. Concerning sleep parameters, temazepam induces a statistically significant reduction of: phase shifts; number of awakenings; percent duration of sleep stages I and IV. A significant increase of the percent duration of stage II and sleep efficiency was also found. Camazepam shows modification, with the same trend, but not reaching statistical significance. Concerning spectral analysis, temazepam induces a light increase of the relative power of the slowest frequencies, paralleled by an increase of the fast bands, while major effects are found on the characteristic periodicity of delta activities, which appear disrupted by the drug. These effects are not evident with camazepam, which does not seem to distort the normal sleep pattern.

Adult↗