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Biomedical subjects

S Conti

Publications and source records attributed to S Conti.

At least 37 records · Page 2Linked to original sources

Detection by immunofluorescent anti-idiotypic antibodies of yeast killer toxin cell wall receptors of Candida albicans.

Yeast killer toxin cell wall receptors of Candida albicans were observed by indirect immunofluorescence using an affinity purified rabbit anti-idiotypic antiserum. The antiserum had been raised against a monoclonal antibody neutralizing the in vitro activity of a killer toxin produced by a selected strain of Hansenula anomala UCSC 25F. This simple procedure permitted the location of killer toxin cell wall receptors in various morphological phases of the yeast cells. The use of the indirect immunofluorescence technique with anti-idiotypic antibodies may have potential value in determining the occurrence of killer toxin receptors in other microbial systems.

Antibodies, Anti-Idiotypic

Production of yeast killer toxin in experimentally infected animals.

The ability of a killer yeast (Pichia anomala, UCSC 25F) to produce toxin in vivo was demonstrated, for the first time, in tissues of normal and immunosuppressed experimentally infected mice by means of a fluorescent antibody technique and a killer toxin specific monoclonal antibody. The possible significance of the findings is discussed.

Animals

Hypochondriacal fears and beliefs 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 3 different occasions. For each trimester of pregnancy, women displayed more hypochondriacal fears and beliefs and conviction of disease (disease phobia) than normal controls. In the third trimester, they also reported more fear of dying and bodily preoccupations. 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 well-being and the health attitudes of pregnant women. If properly recognized, they may effectively be treated.

Adult

Prevalence of hepatitis B infection among hospital personnel in Addis Ababa (Ethiopia).

Hepatitis B serological markers (HBsAG, anti-HBc and anti-HBs) were determined in 432 (60%) hospital employees by the Hepanostika microenzyme linked immunoassay method. The overall prevalence rate was 9.02% for HBsAg, 46.25% for anti-HBs, 73.6% for anti-HBc and 76.38% for "at least one marker positive". Marker positivity as well as HBsAg carrier rate is higher for males than for females. (82.0 Vs 69.9%; 11.4 Vs 6.75% respectively). The majority of the infections occur early in life, 75% being positive for "at least one marker" by age twenty. The distribution of markers is somewhat different from previous observations with non-hospital personnel. Departments most exposed to blood and certain job categories seem to be an increased risk of acquiring the infection. We conclude that hospital exposure is associated with an additional risk of hepatitis B infection.

Adolescent

Biotyping of bacterial isolates using the yeast killer system.

Forty-four presumptive killer yeasts were tested against bacterial isolates, including rapid-growing gram-positive and gram-negative bacteria, as well as slow-growing bacteria, such as the mycobacteria. A killer system, based on the patterns of bacterial susceptibility to the action of nine selected killer yeasts, was developed for epidemiological purposes. The killer system, previously standardized for yeasts and hyphomycetes, was adapted to the specific growth conditions of the bacterial isolates. The results obtained confirm that susceptibility to the yeast killer phenomenon is widespread among microorganisms unrelated to yeasts and that it could form the basis for a convenient and adaptable biotyping method in microbiological laboratories.

Bacterial Typing Techniques

Studies on the epidemiology of Aspergillus fumigatus infections in a university hospital.

The impact of the airborne opportunistic fungus pathogen, Aspergillus fumigatus in patients hospitalized at the university hospital of Parma, Italy, and its outpatients was investigated during a period of six months. Sputum and bronchial washings were collected from 986 patients. The 2,437 specimens were culturally examined for the presence of A. fumigatus regardless of the patient's clinical diagnosis. This fungus was isolated from 32 patients (3.2%). Subsequently, immunological tests for aspergillosis were performed on 22 of these culture-positive patients. Eight of these patients (36.4%) were serologically proven to be affected by aspergillosis. The 32 A. fumigatus isolates were epidemiologically investigated by the killer system to determine the mode of spread of these infections. Among the patients, fifteen different biotypes were differentiated, and their value in studying the epidemiology of aspergillosis in the hospital environment was investigated.

Adolescent

Serological study of yeast killer toxins by monoclonal antibodies.

Yeast killer toxins coded by determined and undetermined killer plasmids or presumptive nuclear gene(s) in various genera (Saccharomyces, Kluyveromyces, Pichia and Candida) have been serologically investigated by a monoclonal antibody (KT4), produced against the yeast killer toxin of Pichia (Hansenula) anomala UCSC 25F. Double immunodiffusion with the killer toxins as antigens and indirect immunofluorescence on whole cells of the corresponding killer yeast have been used. In both the serological procedures, monoclonal antibody KT4 proved to be reacting only with the killer toxins and the whole cells of yeasts belonging to the genus Pichia.

Antibodies, Monoclonal

Biotyping of pathogenic fungi by the killer system and with monoclonal antibodies.

Biotyping of pathogenic yeasts and hyphomycetes based on their susceptibility to selected killer yeasts and their reactivity with monoclonal antibodies are described. Both methods were used to differentiate fungi isolated from patients providing valuable epidemiological information on mycotic infections. The functional biotyping obtained with the two systems and the conventional auxenographic biocoding approaches commercially available for opportunistic yeasts are comparatively evaluated. The potential for biotyping of industrial fungal isolates is also discussed.

Antibodies, Monoclonal

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

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

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

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

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

[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

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