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Biomedical subjects

S Conti

Publications and source records attributed to S Conti.

At least 109 records · Page 6Linked to original sources
PubMed1989

Functional studies on the cholinergic and sympathetic innervation of the rat proximal urethra: effect of pelvic ganglionectomy or experimental diabetes.

1. Isolated rings of rat proximal urethra contracted in response to acetylcholine, noradrenaline, phenylephrine, tachykinins or field stimulation. In the presence of field stimulation-induced contractions, isoprenaline or CGRP produced an inhibitory effect on evoked contractions. 2. Electrical field stimulation produced frequency-related contractions which, when using trains of stimuli, consisted of a phasic and a tonic response. These contractions were abolished by tetrodotoxin (1 microM) but unaffected by hexamethonium (10 microM). 3. Atropine (3 microM) produced a partial inhibition of these nerve-mediated contractions, slightly more evident on the tonic than the phasic response. In the presence of atropine (3 microM), phentolamine (3 microM) or prazosin (1-10 nM) produced an almost complete inhibition of the response to field stimulation. 4. After bilateral removal of the pelvic ganglia, electrical field stimulation was still able to induce tetrodotoxin-sensitive contractions of the rat proximal urethra. However, the inhibitory effect of atropine was much reduced as compared to controls, while the phentolamine-sensitive portion of the response was increased. 5. DMPP (0.1 mM) a nicotinic receptor agonist, produced a contraction (phasic and tonic components) which was strongly inhibited by hexamethonium (10 microM), abolished by prazosin (1 microM) and reduced by tetrodotoxin (3 microM). 6. In urethral rings from diabetic rats (i.v. streptozotocin 7-9 weeks before) the contractile response to acetylcholine or noradrenaline as well as the response to field stimulation were unchanged as compared to controls. 7. Capsaicin (1 microM) produced an inhibitory effect on the nerve-mediated contractions of the rat proximal urethra. This response was abolished by pelvic ganglionectomy but was unaffected in streptozotocin-treated rats. 8. These findings provide functional evidence that both cholinergic and noradrenergic nerves mediate the contractions of the rat proximal urethra. In addition, capsaicin-sensitive sensory nerves can produce certain local motor responses through release of endogenous neuropeptides. In vivo studies are needed to examine the interplay between these differents sets of motor nerves in the regulation of proximal urethra motility.

Acetylcholine↗
PubMed1989

Yeast killer toxins and dimorphism.

The differential action of four selected yeast killer toxins on the mycelial and yeast forms of four isolates of the dimorphic fungus Sporothrix schenckii was comparatively evaluated. The results confirmed that the yeast killer phenomenon is present among hyphomycetes and yeasts and that both morphological forms of S. schenckii are susceptible to the action of the same yeast killer toxin. Quantitative differences in the response to the killer action of the mycelial and yeast forms in individual strains were also observed. To avoid retroconversion of the dimorphic forms, we used a modification of the conventional killer system.

Colony Count, Microbial↗
PubMed1989

Cardiac neurosis and psychopathology.

Psychiatric illness according to DSM-III-R criteria was investigated in 54 consecutive patients suffering from cardiac neurosis (neurocirculatory asthenia or Da Costa's syndrome). Thirty-seven of the 54 patients (68.5%) were found to suffer from a psychiatric disorder. Generalized anxiety disorder, social phobia and panic disorder accounted for most of the diagnoses. Panic disorder was frequently preceded by (and associated with) generalized anxiety, phobic avoidance and hypochondriasis. The results should alert the physician to inquire for symptoms of an anxiety disorder when a patient presents with cardiac neurosis.

Adult↗
PubMed1989

Hypochondriacal symptoms in pregnancy.

Illness attitudes were evaluated in 26 pregnant women and 26 control subjects matched for sociodemographic variables, by means of a self-rating scale, on three different occasions. In each trimester of pregnancy, women displayed more hypochondriacal fears and beliefs and conviction of disease (disease phobia) than normal controls (p less than 0.001). The findings should alert physicians to ask their pregnant patients whether they are preoccupied with fear of dying, or are concerned that they suffer from an undiagnosed physical illness, or dread a specific illness such as cancer or heart disease. Hypochondriacal fears and beliefs are liable to affect the well-being and health attitudes of pregnant women. If properly recognized, they may effectively be treated.

Female↗
PubMed1989

Regional differences in the motor and inflammatory responses to capsaicin in guinea pig airways. Correlation with content and release of substance P-like immunoreactivity.

The motor and inflammatory effects of capsaicin, substance P, and neurokinin A, as well as the content and release of substance P-like immunoreactivity (SP-LI), were assessed in the upper and lower guinea pig trachea and in the main bronchus. Capsaicin-induced motor and inflammatory effects were greater in the lower than in the upper tract of the trachea and much more evident at the bronchial than at the tracheal level. On the other hand, no significant regional differences were observed in the potency and efficacy of tachykinins. SP-LI content was significantly greater in the lower than in the upper tract of the trachea and about five times greater in the bronchus than in the trachea. In each single tracheal preparation, a highly significant correlation was found between the motor effect of capsaicin (but not carbachol) and the SP-LI content. Furthermore, capsaicin-induced release of SP-LI was about eight times greater in bronchial than in tracheal tissues. In view of the strict correlation observed between magnitude of motor and inflammatory actions of capsaicin (but not substance P or neurokinin A) and SP-LI content and release, it is proposed that the regional differences in the response of guinea pig respiratory tissues to activation of capsaicin-sensitive sensory fibers might be mainly prejunctional in origin.

Animals↗
PubMed1989

[Ultrastructural analysis of human ejaculate from infertile subjects].

It has been demonstrated that the semen of infertile patients contains at high percentage of abnormal forms and no clear answer has been so far provided to the questions of which malformations are compatible with male fertility, which malformations are responsible for the infertility and which is the percentage of defective cells that gives rise to infertility. In this study the eiaculates of 56 patients of suspected male infertility were used as material. The semen samples were fixed for 2 hr at room temperature in 4% glutaraldehyde in 0.05 M cacodilate buffer + 0.018% CaCl2 + 6.6% sucrose, post-fixed in 1.5% OsO4 in same buffer + 6.6% sucrose, dehydrated and embedded in Spurr. The samples were sectioned with Reichert OMu3 ultratome. The sections, contrasted with uranyl acetate and lead citrate, were examined in a Feol M T8 E.M. The varieties of sperm malformations are described and classificated into morphological categories based upon the type of alteration and the cellular portion in which the malformation appeared. From this research we have got the following conclusions: 1) an absolute correlation between microscopical, ultrastructural defects and functionality of spermatozoa does not exists; 2) the submicroscopic analysis contributes to a more accurate definition of the eiaculate; 3) the high variability of the ultrastructural defects needs that the submicroscopical analysis of the human semen must be supplemented by a quantitative evaluation.

Humans↗
PubMed1989

Risk behaviors for HIV-1 infection in Italian drug users: report from a multicenter study. First Drug User Multicenter Study Group.

In June 1987, a cross-sectional study was carried out on drug users attending public centers for drug dependency in Italy. Observed proportions of HIV seropositives among the 1,363 subjects from 34 public centers in 11 regions included in the study varied widely, with an overall seropositivity rate of 37%. Sharing syringes/needles, already used by other intravenous drug users, for preparing and injecting drugs represented independent risk factors for HIV-1 infection, while sexual lifestyle did not. Risk of infection increased with frequency of sharing equipment for preparing and for injecting drugs. Modification of risk behaviors in drug use was reported more frequently than in sexual lifestyle; both were significantly associated with knowledge of being seropositive for HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1988

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↗
PubMed1987

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↗
PubMed1987

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↗