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Biomedical subjects

F Valente

Publications and source records attributed to F Valente.

At least 19 recordsLinked to original sources
PubMed2002

Excess of allele1 for alpha3 subunit GABA receptor gene (GABRA3) in bipolar patients: a multicentric association study.

The available data from preclinical and pharmacological studies on the role of gamma amino butyric acid (GABA) support the hypothesis that a dysfunction in brain GABAergic system activity contributes to the vulnerability to bipolar affective disorders (BPAD). Moreover, the localization of the alpha3 subunit GABA receptor GABRA3 gene on the Xq28, a region of interest in certain forms of bipolar illness, suggests that GABRA3 may be a candidate gene in BPAD. In the present study, we tested the genetic contribution of the GABRA3 dinucleotide polymorphism in a European multicentric case-control sample, matched for sex and ethnogeographical origin. Allele and genotype (in females) frequencies were compared in 185 BPAD patients and 370 controls. A significant increase of genotype 1-1 was observed in BPAD females compared to controls (P=0.0004). Furthermore, when considering recessivity of allele 1 (females with genotype 1-1 and males carrying allele 1), results were even more significant (P= 0.00002). Our findings suggest that the GABRA3 polymorphism may confer susceptibility to or may be in linkage disequilibrium with another gene involved in the genetic etiology of BPAD.

Alleles↗
PubMed2001

Ambient temperature is associated with changes in infants' arousability from sleep.

STUDY OBJECTIVE: To evaluate the influence of ambient temperature on infants' arousability from sleep. DESIGN: Two groups of healthy infants with a median age of 11 weeks were recorded polygraphically during one night: 31 infants were studied at 24 degreesC and 31 infants at 28 degreesC. To determine their arousal thresholds, the infants were exposed to white noises of increasing intensities during REM and NREM sleep. Arousal thresholds were defined by the auditory stimuli needed to induce arousals. SETTING: N/A. PATIENTS OR PARTICIPANTS: N/A. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: The arousal thresholds decreased across the night in the infants sleeping at 24 degreesC (p=.017). The finding was not found for the infants sleeping at 28 degreesC. When analyzing the arousal responses according to time of the night, it was found that the auditory thresholds were significantly higher at 28 degreesC than at 24 degreesC between 03:00 hr and 06:00 hr (p=.003). These findings were only seen in REM sleep. CONCLUSION: High ambient temperature could add to the difficulty to arouse from REM sleep in the late hours of the night.

Acoustic Stimulation↗
PubMed2000

Massive outbreak of poliomyelitis caused by type-3 wild poliovirus in Angola in 1999.

The largest outbreak of poliomyelitis ever recorded in Africa (1093 cases) occurred from 1 March to 28 May 1999 in Luanda, Angola, and in surrounding areas. The outbreak was caused primarily by a type-3 wild poliovirus, although type-1 wild poliovirus was circulating in the outbreak area at the same time. Infected individuals ranged in age from 2 months to 22 years; 788 individuals (72%) were younger than 3 years. Of the 590 individuals whose vaccination status was known, 23% had received no vaccine and 54% had received fewer than three doses of oral poliovirus vaccine (OPV). The major factors that contributed to this outbreak were as follows: massive displacement of unvaccinated persons to urban settings; low routine OPV coverage; inaccessible populations during the previous three national immunization days (NIDs); and inadequate sanitation. This outbreak indicates the urgent need to improve accessibility to all children during NIDs and the dramatic impact that war can have by displacing persons and impeding access to routine immunizations. The period immediately after an outbreak provides an enhanced opportunity to eradicate poliomyelitis. If continuous access in all districts for acute flaccid paralysis surveillance and supplemental immunizations cannot be assured, the current war in Angola may threaten global poliomyelitis eradication.

Acute Disease↗
PubMed2000

The influence of a pacifier on infants' arousals from sleep.

OBJECTIVE: The risk of sudden infant death during sleep was postulated to decrease with the use of a pacifier and by conditions facilitating arousals from sleep. We evaluated the influence of a pacifier on arousal from sleep in healthy infants. STUDY DESIGN: Fifty-six healthy infants were studied with polygraphy during 1 night; 36 infants used a pacifier regularly during sleep, and 20 never used a pacifier. Thumb users or occasional pacifier users were not included in the study. The infants were recorded at a median age of 10 weeks (range 6 to 19 weeks). To evaluate auditory arousal thresholds, the infants were exposed to white noise of increasing intensity during rapid eye movement sleep. RESULTS: Polygraphic arousals occurred at significantly lower auditory stimuli in pacifier users than in nonusers (P =.010). Compared with nonusers, pacifier users were more frequently bottle-fed than breast-fed (P =. 036). Among infants sleeping without a pacifier, breast-fed infants had lower auditory thresholds than bottle-fed infants (P =.049). CONCLUSIONS: Infants using pacifiers during sleep had lower auditory arousal thresholds than those who did not use a pacifier during sleep. Breast-feeding could be a further factor contributing to lower arousal thresholds. These findings could be relevant to the occurrence of sudden infant deaths during sleep.

Arousal↗
PubMed1998

Introduction: the EUROCARE II Study.

This introduction provides a general overview of the aims, methods and procedures used in the EUROCARE II study and the types of analyses presented in each article of this Special Issue of the European Journal of Cancer. The main aims of the EUROCARE II project are the updating of the survival database of the European Cancer Registries, the study of recent trends in relative survival rates and the interpretation of the survival differences observed both in time and across populations. Once having completed the preliminary stage of data checking, a total of 3,473,659 individual records from patients of all cancer sites, diagnosed between 1978 and 1989 and provided by 45 cancer registries in 17 European countries were accepted to build up the EUROCARE database. The quality of these data, in terms of the accuracy of the diagnosis and the validity of vital status assessment, was checked by indirect indicators, based on cross-validation analysis of consistency of the relevant variables. Statistical analysis was based on age-specific relative survival rates, computed for each cancer sites as the ratio of observed survival to the expected survival of the general population of the same area, gender and age, according to the Hakulinen method. An estimate of the European survival was computed as a weighted mean of the corresponding survival of the different countries, using as weights the expected yearly number of incident cases in each country. For comparison purposes, age-standardised survival was also calculated for Europe and for each country involved in the study.

Europe↗
PubMed1997

tTGase/G alpha h protein expression inhibits adenylate cyclase activity in Balb-C 3T3 fibroblasts membranes.

Stably transfected Balb-C 3T3 fibroblasts (clone 5), overexpressing a catalytically active tissue transglutaminase, showed a basal adenylate cyclase activity lower than control cells (clone 1). Several modulators of the adenylate cyclase activity (forskolin, Mn2+ and pertussis toxin) showed the existence of a marked negative control on the adenylate cyclase activity present in clone 5 cells. Very interestingly, this same marked negative control was also found in a Balb-C 3T3 fibroblast clone stably transfected with a mutagenized human tissue transglutaminase (mut277 cys > ser) virtually devoid of transglutaminase catalytic activity (clone Ser). Conversely, a significant increase of the adenylate cyclase activity was observed in bovine aortic endothelial cells after the lowering of tissue transglutaminase expression levels by the transfection of an eukaryotic expression vector containing the gene for tissue transglutaminase in antisense orientation. All these findings suggest a possible role for type II tissue transglutaminase as a negative modulator of the adenylate cyclase activity in different cell types, beside its transglutaminase enzyme activity.

3T3 Cells↗
PubMed1997

[Chorioangioma of the placenta].

Chorioangioma is the most frequent nontrophoblastic tumour of the placenta, with a reported incidence ranging from 0.01% to 1.3%. The authors describe three cases of placental chorioangiomas, two of these diagnosed prenatally by ultrasound, and the clinical implications for both mother and fetus. Premature delivery and hydramnios were the obstetric complications associated with these vascular tumours. We confirmed this diagnosis by histologic examination, in all cases.

Adult↗
PubMed1997

[Our experience with pediatric pH-metry].

INTRODUCTION AND METHODS: The authors present their experience of pH monitoring in children performed in patients in the Pediatric Division selected on the basis of the following criteria: endoscopic evidence of incontinent cardia with or without oesophagitis, presence of pyrosis/epigastralgia even in the absence of objective endoscopic findings, dry cough without bronchopulmonary findings, vomit with apparent endoscopic causes, presence of anti-helicobacter antibodies with clinical symptoms. RESULTS: The authors report their findings and discuss them in comparison to the literature. CONCLUSIONS: They conclude by affirming that pH monitoring is a well tolerated and easily performed test in children. It may provide indications and useful clarifications regarding a number of pathologies often over- or undervalued by the doctors in charge or parents, leading to the start of correct treatment with excellent clinical results.

Adolescent↗
PubMed1995

Anterior fontanelle pressure variations during sleep in healthy infants.

Our aim was to study the intracranial pressure (ICP) variations during sleep normal infants. Using a noninvasive method, ICP was measured continuously during polysomnography in 12 healthy infants aged from 1 to 11 months (median 3.5 months). We analyzed the variations of mean basal ICP, mean basal pulse pressure amplitude and maximal amplitude of both plateau and B-like waves between transient sleep, quiet sleep and rapid eye movement (REM) sleep. Mean ICP, mean pulse pressure amplitude and B-like wave amplitude increased significantly during transient sleep and REM sleep. Plateau waves occurred during transient sleep and especially REM sleep. By contrast, noninvasive ICP recordings were relatively flat during quiet sleep stages 2 and 3. ICP variations and pressure waves seem to be related to cerebrovascular changes associated with sleep. The physiological ICP variations during sleep must be known in order to allow correct interpretation of continuous ICP measurements in infants.

Humans↗
PubMed1994

Time trends of lung and larynx cancers in Italy.

During the period 1970-1989, age-adjusted mortality rates for lung cancer in Italy increased by more than 50%, while rates for larynx cancer in males decreased by approximately 13%. This study aims to interpret this difference, which seems to contradict the finding that cigarette smoking is a common major risk factor for both lung and larynx cancer. To this end, we jointly analyzed the time trends of incidence, survival and mortality. We first examined survival data taken from the population-based Lombardy Cancer Registry (northern Italy). Based on data referring to 880 incident cases of larynx cancer, diagnosed during the period 1976-1987, we estimated a 3% annual increase in relative survival. By contrast, no significant period effect was observed for survival rates of 2,259 incident cases of lung cancer. National incidence rates were estimated using official mortality data and the above-described survival data. Age-adjusted estimated incidence rates increased, from 1970 to 1989, for both cancer sites: +55% for male lung, +56% for female lung, and +22% for male larynx. Moreover, the patterns of birth-cohort effect, which are diverging for mortality, are nearly parallel with regard to incidence. This analysis suggests that a substantial improvement in survival of larynx cancer patients may largely explain the differences in mortality trends for cancer of lung and larynx.

Adolescent↗
PubMed1994

Dyspnoea and flow-volume curve during exercise in COPD patients.

The purpose of this study, in patients with chronic obstructive pulmonary disease (COPD), was to examine the relationship of dyspnoea, rated on a visual analogue scale (VAS), to 1) tidal ventilatory variables measured on exercise and 2) pre-exercise lung function. Twenty one patients (forced expiratory volume in one second (FEV1) mean (SD) 1.19 (0.32) l) were studied. During a preliminary test, the maximal workload was assessed and the upper end of the VAS was anchored. On the study day, the tidal flow-volume curve on exercise was monitored and dyspnoea was assessed serially every minute. In each individual, the relationship of dyspnoea to various tidal ventilatory variables was studied using linear regression analysis; results were reported squared correlation coefficients, slopes and dyspnoea thresholds. Subsequently, the relationship of slopes and thresholds to pre-exercise lung function was examined. In all patients, dyspnoea showed a close correlation with ventilation, tidal volume, breathing frequency and tidal flow. The tidal peak inspiratory flow was the best individual predictor of dyspnoea with a median r2 of 0.91. Patients with the poorest pre-exercise lung function exhibited the highest rates of increase in dyspnoea and the lowest thresholds, the strongest correlation being observed between the dyspnoea/ventilation slope and pre-exercise maximal peak inspiratory flow (r2 = 0.54). In conclusion, for individual COPD patients dyspnoea on exercise is closely related to inspiratory flow. The degree of pre-exercise ventilatory impairment accounts, at most, for only half of the variation in dyspnoea perception between subjects.

Dyspnea↗
PubMed1993

ras oncogene-induced transformation of a rat seminal vesicle epithelial cell line produces a marked increase of adenylate cyclase and protein kinase C activities.

Cells transformed by Kirsten murine sarcoma virus (Ki-MSV) have basal adenylate cyclase activity (AC) higher than control cells and comparable level of forskolin-stimulated AC activity. Moreover, a higher protein kinase C (PKC) activity was found to be present in the transformed cells. The molecular mechanism underlying the increase of AC activity was investigated. Our findings strongly suggest that this biochemical event is due to a marked decrease of the alpha i negative control of the enzyme, even though the alpha i of transformed cells appears to possess fully functional domains interacting with both the effector enzyme and the agonist-activated receptor.

Adenosine Diphosphate Ribose↗
PubMed1993

Prognostic factors of early fatal outcome and long-term survival in patients with Pneumocystis carinii pneumonia and acquired immunodeficiency syndrome.

Fifty-five episodes of Pneumocystis carinii pneumonia (PCP) in AIDS patients were evaluated to assess clinical and laboratory risk factors predicting the probability of surviving the acute episode of PCP and the long-term survival after PCP. Age > 45 yrs, PaO2 < 50 mmHg, AaPO2 > 50 mmHg, and LDH > 800 IU/L correlated strongly with early mortality; patients who needed mechanical ventilation had a significantly lower PaO2 and serum albumin, and higher AaPO2 and LDH compared to the patients who did not. Neither age nor PaO2, AaPO2, LDH, albumin, days from onset, time for recovery, CD4+ cell count correlated with long-term survival of AIDS patients with PCP. Informations obtained at initial presentation of PCP may predict early outcome and influence therapeutic approach, improving chances for survival.

AIDS-Related Opportunistic Infections↗
PubMed1993

Therapeutical doses of salbutamol inhibit the somatotropic responsiveness to growth hormone-releasing hormone in asthmatic children.

In humans beta-adrenergic receptors mediate an inhibitory effect on somatotropic function, likely via stimulation of hypothalamic somatostatin release. Accordingly, salbutamol (SAL), a beta 2-agonist, given iv abolishes the GH response to GH-releasing hormone (GHRH) in adults. Taking into account that in bronchial asthma an alteration in the beta-adrenergic neural control of airways has been hypothesized, we aimed to verify whether, in asthmatic children, beta-adrenergic activation inhibits or not GH secretion. To this goal, we studied the effect of therapeutical doses of SAL on GH response to GHRH in 15 asthmatic children (12 M and 3 F, 5.9-11.1 yr, pubertal stage I-II). All children underwent a GHRH test (1 microgram/kg iv). Moreover, in 7 children (group A), SAL was administered orally (0.125 mg/kg) 1 h before GHRH, while in 8 (group B) by inhaled aerosol (2 mg) 30 min before GHRH. Oral SAL (group A) abolished the GHRH-induced GH rise (AUC, mean +/- SE 165.1 +/- 33.3 vs 959.9 +/- 158.1 micrograms/L/h; p < 0.03). In group B, the GH response to GHRH was only blunted by inhaled SAL (938.6 +/- 284.6 vs 1378.8 +/- 315.6 micrograms/L/h; p < 0.02). In conclusion, our data show that in asthmatic children, therapeutical doses of SAL exert a marked inhibitory effect on GH secretion. Further studies are needed to exclude detrimental effects of chronic treatment with beta 2-agonists on GH secretion and growth velocity in asthmatic children.

Administration, Oral↗
PubMed1993

Evidence against depletion of the growth hormone (GH)-releasable pool in human primary hypothyroidism: studies with GH-releasing hormone, pyridostigmine, and arginine.

We investigated whether the impaired GH secretion of hypothyroid patients could be due to an increase in hypothalamic somatostatinergic tone. Twenty-four patients with primary hypothyroidism [20 females and 4 males; mean age (+/- SE), 47.5 +/- 2.7 yr] and 20 normal subjects (17 females and 3 males; age, 47.6 +/- 3.0 yr) were studied. In the first group of 12 hypothyroid patients, administration of pyridostigmine, a cholinergic agonist drug (120 mg, orally, at -60 min), notably increased GH responses to GH-releasing hormone (GHRH; 1 microgram/kg, iv, at 0 min; peak GH levels for pyridostigmine plus GHRH vs. placebo plus GHRH, 16.6 +/- 4.9 vs. 6.0 +/- 1.8 micrograms/L; P < 0.01). The GH responses to pyridostigmine plus GHRH, however, were considerably lower than those in 10 normal subjects (peak GH levels, 53.0 +/- 3.5 micrograms/L; P < 0.001). In the second group of 12 hypothyroid patients, arginine infusion (30 g, iv, from 0-30 min) markedly increased the GH responses induced by GHRH administration (1 microgram/kg, iv, at 0 min; peak GH levels for arginine plus GHRH vs. placebo plus GHRH, 30.6 +/- 4.7 vs. 5.3 +/- 1.0 micrograms/L; P < 0.001). However, GH release after GHRH plus arginine was greater in 10 normal subjects than in the hypothyroid patients (peak GH levels, 50.9 +/- 5.3 micrograms/L; P < 0.001). Pyridostigmine and arginine inhibit hypothalamic somatostatin tone. The stimulatory effect of both agents on GHRH-induced GH release indicates that reduced GH secretion in hypothyroidism can be reversed to a considerable extent by inhibiting hypothalamic somatostatinergic tone. The relatively greater potency of arginine compared to pyridostigmine suggests that hypothyroid patients may have an impairment of the cholinergic pathways. Furthermore, these data show that hypothyroid patients have a somatotrope secretory capacity much greater than previously thought.

Adult↗