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Biomedical subjects

S Conti

Publications and source records attributed to S Conti.

At least 55 records · Page 3Linked to original sources

Neurokinin A-(4-10): a potent bronchospastic agent virtually devoid of sialologic properties in anaesthetized guinea-pigs.

The ability of substance P, neurokinin A and its C-terminal fragment, neurokinin A-(4-10), to elicit NK-1 (salivation) and NK-2 (bronchospasm) receptor-mediated responses was investigated in anaesthetized guinea-pigs. Neurokinin A-(4-10) produced a dose-related increase in tracheal insufflation pressure and its maximal effect was similar to that elicited by neurokinin A and significantly greater than that of substance P. On the other hand substance P induced a potent dose-dependent increase of salivation while neurokinin A was significantly less potent. Neurokinin A-(4-10) did not exert any sialologic effect even at the dose of 100 nM/kg. These findings indicate that neurokinin A-(4-10) might be a valuable pharmacological tool for characterizing the involvement of NK-1 and NK-2 receptors in physiological responses in vivo.

Anesthesia

Ethiopian National Hepatitis B Study.

A nationwide seroepidemiological study of hepatitis B markers prevalence was conducted in Ethiopia on 5,270 young males from all regions of the country. Overall prevalence rates were 10.8% for HBsAg and 73.3% for "at least one marker positive"; a remarkable geographical and ethnic variability of marker prevalence was observed, reflecting the wide differences existing in Ethiopia in sociocultural environment and activities such as tribal practices and traditional surgery. Sexual practices and medical exposure also play some role as determinants of hepatitis B marker prevalence in Ethiopia. General preventive measures, with particular reference to health education, by affecting incriminating habits and practices could have some impact on infection rates in Ethiopia, in the absence of a vaccination strategy presently unrealistic in this region of the world.

Adolescent

Delta hepatitis virus infection in Ethiopia.

The results of Hepatitis Delta virus (HDV) antibody determinations carried on 566 HBsAg positive serum samples from a population of 5270 Ethiopian military recruits are reported. The prevalence of anti-HDV among apparently healthy HBsAg carriers was 5.8%. The prevalence increases with age within the available range (18-30 years). Differences might exist by area of origin and ethnic groups. The distributions of HBV markers was similar in anti HDV positive and anti HDV negative individuals, possibly due to the relatively young age of the population and/or the hyperendemic condition of the area.

Adolescent

Hepatitis B infections in the Arsi region of Ethiopia.

In a sample of inhabitants of the Arsi region of Ethiopia prevalence of hepatitis B is around 80% in the age group 20-24. In addition to age, sex and size of family, exposure to tribal practices is a determinant of seropositivity in this group accounting for as much as 20% of the total burden of the infection. Waiting for a mass vaccination campaign, presently unrealistic in this area of the world, health education, as part of a comprehensive primary health care program, has to be considered as a potentially effective preventive tool.

Adult

Genital herpes infection in outpatients attending a sexually transmitted disease clinic in Italy.

Prevalence of Herpes Simplex, type 2, specific antibodies was estimated in sexually transmitted disease outpatients: 783 heterosexuals and 158 homosexual-bisexuals. The anti-HSV-2 prevalence rates were 69% in the homosexual-bisexuals and 35% in the heterosexuals. In both groups positive association with age of anti-HSV-2 prevalence was found: only in the homosexual-bisexuals negative association with education level was detected. No difference exists between the two groups regarding the symptomatic/asymptomatic ratio of HSV-2 infection.

Adolescent

Inhibition of thromboxane biosynthesis by 3-pyridinol carboxypentyl ethers substituted with a hydroxylated octyl chain.

Racemic 6-[4-(3'-hydroxy-1'-octenyl)-3-pyridyloxy]hexanoic and 6-[4-(3'-hydroxyoctyl)-3-pyridyloxy] exanoic acids have been synthesized and their activity as inhibitors of the biosynthesis of thromboxane A2 in human serum has been studied, in comparison with isomers having the eight-carbon chain in the 2 position. Very high, selective activity was found for the new 4-substituted 3-pyridinol ethers, whereas the 2-substituted compounds showed no action.

Depression, Chemical

Blockade by theophylline of capsaicin-induced motor effects in guinea-pig airways.

The effect of theophylline was tested on the capsaicin-induced increase in insufflation pressure in anaesthetized guinea-pigs and contraction of isolated tracheal spirals. Theophylline (6.25-25 mg/kg i.v.) inhibited in a marked, prolonged and dose-related manner the increase in insufflation pressure elicited by i.v. injection of capsaicin (2-10 micrograms/kg). Theophylline, even at plasma concentrations as low as 15-23 micrograms/ml (which are within or slightly higher than the therapeutic range in humans) produced an inhibition of about 30-50% of capsaicin-induced bronchospasm. Theophylline was significantly less effective in antagonizing the bronchospasm elicited by maximally effective dose (100 micrograms/kg i.v.) of acetylcholine as well as by a dose equieffective to capsaicin 10 micrograms/kg (i.e. acetylcholine 50 micrograms/kg). Theophylline (30 microM-1 mM) also inhibited potently and concentration dependently the capsaicin-induced contraction in vitro and, again, it was significantly less effective against cholinomimetic-induced responses. These data suggest that theophylline can interfere, at therapeutic doses, with some process(es) selectively involved in capsaicin-induced neuropeptide-mediated bronchoconstriction. Since capsaicin-sensitive sensory fibers are thought to be involved in the pathogenesis of bronchial hyperreactivity and asthma, these inhibitory actions of theophylline might be relevant for its therapeutic effects.

Acetylcholine

Immunity to tetanus among Italians born between 1956 and 1963.

Systematic mandatory immunization of children against tetanus begun in Italy in 1968. Preceding birth cohorts, accounting for almost 80% of present Italian population, were poorly immune or totally non-immune; around 90% of cases of tetanus occurring in Italy in recent years are observed among them. In a national sample of 4770 young males born between 1956 and 1963, about one third was not protected. Prevalence of non-immune subjects was greater in the Southern Regions and the Islands, in rural areas, among the unemployed, among the older birth cohorts.

Adolescent

Prevalence of hyperimmunization against tetanus in a national sample of 18-26 year old immune subjects in Italy.

Prevalence of tetanus hyperimmunization was estimated among 3217 immune subjects to be approximately equal to 11%. Hyperimmunization was associated with age, area of residence and health care availability. Indiscriminate administration of booster doses of tetanus vaccine could result in some areas in unnecessary revaccinations and possibly hypersensitivity reactions. The immunization policy regarding booster doses should be based on factual evidence and not on rigid recommendations.

Adolescent

Coronary risk factors and survival probability from coronary and other causes of death.

The analysis concerns the two rural Italian cohorts of the Seven Countries Study and includes 1,712 men who, at the entry examination in 1960, were aged 40-59 years and whose 20-year follow-up examinations were complete for life status, dates, and causes of death. Excluded were 175 men because they lacked one or more of the risk factors selected for the study. A total of 517 deaths occurred in the remaining 1,537 men. The Cox proportional hazards regression model was applied with a forward procedure to include the entry risk factors in the model. First, total mortality was used as the endpoint. Then the risk factors identified as being related to total mortality were used to predict specific causes of death, i.e., coronary heart disease, stroke, cancer, violent death, and other causes. Blood pressure appeared as a nonspecific risk factor for all causes, including cancer and violence, forced expiratory volume and arm circumference appeared as nonspecific risk factors, smoking habits could not be easily classified, and cholesterol was definitely specific only for coronary deaths. Models for estimating survival probabilities from total mortality and from any of several causes of death are provided.

Adult

The prediction of future health in healthy middle-aged men.

Two cohorts of men aged 49-59 at entry, representing cluster samples of two rural areas in Northern and Central Italy, for a total of 1712 subjects have been followed-up for 20 years within an epidemiological study originally designed for cardiovascular disease. After 20 years, only 41 men have been judged to have remained substancially healthy throughout the observation period, i.e. free from a number of major diseases. Univariate and multivariate analyses trying to predict the maintenance of health status showed that among 21 selected characteristics only the following one had a significant power: age, cigarette smoking (adverse effect) and vital capacity (favourable effect). A minor role was also played by the body mass index (adverse effect) and forced expiratory volume (favourable effect). Those who did not remain healthy exibited a greater increase in blood pressure and body mass index.

Adult

Risk factors for definite hypertension: cross-sectional and prospective analyses of two Italian rural cohorts.

Risk factors for definite hypertension were examined using data from two Italian rural cohorts from the Seven Countries Study, originally composed of 1,712 men ages 40-59 at entry. Two approaches were used: cross-sectional examination of baseline exposure/outcome measurements; and prospective examination of data, correlating baseline measurements with subsequent definite hypertension, diagnosed at the 10-year follow-up exam. Hypertension was defined as diastolic blood pressure greater than or equal to 95 mm Hg or systolic blood pressure greater than or equal to 160 mm Hg. Included in the cross-sectional analysis were 1,437 subjects free from other cardiovascular diseases at baseline. Of these, 590 were included in the prospective analysis. Using a multiple logistic function that did not include baseline (normal) blood pressure, age, pulse rate, and weight were confirmed as risk factors for hypertension both cross-sectionally and prospectively, thus suggesting that bias cannot explain the relationship of hypertension to these factors. Although proteinuria and vital capacity were associated with hypertension in the cross-sectional analysis, no such relationships were detected prospectively, thus implying that these factors are effects, rather than determinants, of definite hypertension. Smoking had a negative prospective (but not cross-sectional) association with hypertension, which can probably be explained by survival bias at 10 years after ascertainment of smoking habits. When mean baseline blood pressure was added to the prospective multiple logistic function, it became the only factor significantly associated with hypertension (P less than 0.001), again confirming the importance of "tracking" in the determination of hypertension.

Age Factors

Synthesis of guanylhydrazones derived from 3-pyridinol and evaluation of their effect on serum thromboxane B2 and prostaglandin E2 production.

3-Pyridyloxyacetaldehyde guanylhydrazone and the guanylhydrazones of pyridine-2- and -4-aldehydes substituted at the 3-position with the omega-carboxypentyloxy chain were synthesized in order to evaluate their activity as thromboxane synthase inhibitors in vitro. The tested compounds inhibit thromboxane B2 biosynthesis in human serum. The first appears to be a selective inhibitor of thromboxane synthase, since there was a concomitant rise in Prostaglandin E2 (PGE2) level. The derivative of 4-pyridinealdehyde was the more active one of the other two compounds but it also markedly lowered PGE2 biosynthesis proving to be an inhibitor of cyclooxygenase.

Chemical Phenomena

Incidence of coronary heart disease in two generations of men exposed to different levels of risk factors.

Within an epidemiological study on coronary heart disease (CHD) (alive) two samples of middle aged men living in two rural areas of Northern and Central Italy, two subgroups of individuals aged 51-59 (alive), free from CHD (alive) belonging to different generations have been identified. Group A (n = 593) was followed-up from 1960 to 1970 and group B (n = 553) from 1970 to 1980. Entry mean levels of some classical risk factors were higher in group B than in group A (serum cholesterol by 19 mg/dl; diastolic blood pressure by 2.9 mmHg; body mass index by 0.9 units), whereas physical activity at work was lower by 0.2 units of a score. The 10 year incidence of hard-criteria CHD events has been higher though not significantly so in group B by 19%, suggesting a connection with the different levels of risk factors, mainly serum cholesterol.

Blood Pressure

[Risk factors between blood cholesterol and coronary disease].

Some risk functions are presented linking serum cholesterol to the development of coronary heart disease. They are produced from epidemiological studies on Italian population samples made of men aged 40-59 at entry and followed up to 20 years. The purpose is to provide a simple tool for the estimation of the expected risk and of that depending on changes of the risk factor.

Adult