Biomedical subjects
Publications and source records attributed to G Mazzotti.
The alterations induced in the lymphoid and epitelial cells of the Bursa of Fabricius in chicks exposed at different doses of gamma rays mainly occur during the interfase. The extent of these alterations appears reduced in comparison with that observed in the chick thymus treated in the same way.
Different doses of gamma rays induce ultrastructural alterations in limphoid and epithelial cells of the chick thymus which exhibit a different temporal evolution after the treatment. The main changes which occur in lymphoid cells treated with 50 rads disappear 48 hours after the irradiation, while with 100 rads the radiation damage is still evident in epithelial cells.
A correlative morphologic analysis was carried out on isolated metaphase chromosomes by means of field emission in-lens scanning electron microscopy (FEISEM) and atomic force microscopy (AFM). Whereas FEISEM provides ultra-high resolution power and allows the surface analysis of biological structures free of any conductive coating, the AFM allows imaging of biological specimens in ambient as well as in physiologic conditions. The analysis of the same samples was made possible by the use of electrical conductive and light transparent ITO glass as specimen holder. Further preparation of the specimen specific for the instrumentation was not required. Both techniques show a high correlation of the respective morphologic information, improving their reciprocal biological significance. In particular, the biological coat represents a barrier for surface morphologic analysis of chromosome spreads and it is sensitive to protease treatment. The chemical removal of this layer permits high-resolution imaging of the chromatid fibers but at the same time alters the chromosomal dimension after rehydration. The high-resolution level, necessary to obtain a precise physical mapping of the genome that the new instruments such as FEISEM and AFM could offer, requires homogeneously cleaned samples with a high grade of reproducibility. A correlative microscopical approach that utilizes completely different physical probes provides complementary useful information for the understanding of the biological, chemical, and physical characteristics of the samples and can be applied to optimize the chromosome preparations for further improvement of the knowledge about spatial genome organization.
INTRODUCTION: The objectives of the research are to determine the prevalence of major depression after childbirth and compare it with that of non-postpartum women; and to study the risk factors for postpartum depression. METHOD: We studied 425 women: 321 women in the first postpartum year, 41 nulliparous women and 63 women with more than 1 year postpartum. RESULTS: The prevalence of major depression in the first postpartum year was 5.92%; this value was significantly lower than that of the women with more than 1 year postpartum. In women with less than 2 years postpartum we found less depression than in those with more than 2 years of delivery. The risk factors associated with postpartum depression found by logistic regression were: obsessive-compulsive disorder, premenstrual dysphoric disorder, previous major depression, maternity blues, young age and lower educational grade. CONCLUSIONS: Our study does not support the existence of a greater prevalence of major depression during postpartum in Peruvian women.
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INTRODUCTION: To assess sexual risk behavior for human immunodeficiency virus (HIV) infection and other sexually transmitted diseases (STD) in males with psychotic disorders and to compare it to that of the patients without these disorders. METHODS: We used a structured interview to collect information regarding sexual risk behavior, knowledge about HIV/AIDS, history of STD and drug use. We included 106 patients with psychotic disorders from a psychiatric institution and 89 control medical out-patients from a general hospital. RESULTS: Among psychotic patients, 70.8% declared that they had had sexual intercourse at some time in their lives and 37.7% during the last year. The psychotic patients had significantly less knowledge about HIV/AIDS than the controls and they had a smaller proportion of stable sexual partners and greater frequency of sexual risk behaviors, such as inconsistent condom use and sexual intercourse with prostitutes. In psychotic patients, inconsistent condom use was associated with more hospitalizations. CONCLUSIONS: Although patients with psychotic disorders have reduced sexual activity, they present greater frequency of sexual risk behaviors that predispose them to acquire HIV infection and other STD.
Antacids are often the first therapeutic approach in patients with pyrosis. We carried-out a study on 8 healthy volunteers who underwent a 24 hour gastric pH-metry to assess the real efficacy of magnesium hydroxide administration on gastric acidity. Magnesium hydroxide was alternatively administered at different dosages (400 mg or 800 mg) in the population studied. Our results showed a mild and non reproducible response to lower dose, but, on the contrary, the 800 mg dose always induced an immediate, effective and prolonged antacid action, reaching a maximum pH value of 5 and lasting up to 40 minutes. Our study confirms, using a modern and reliable technique as the 24-hour gastric pH-metry, the antacid activity of magnesium hydroxide.
INTRODUCTION: We compare the prevalence of obsessive-compulsive symptoms in schizophrenic patients in treatment with clozapine and those who receive classic antipsychotic drugs. METHOD: Outpatients with schizophrenia treated with clozapine (n = 56) or classic antipsychotic drugs (n = 54) at the Honorio Delgado-Hideyo Noguchi Specialized Institute in Mental Health (Lima-Peru), were evaluated for the presence of obsessive-compulsive symptoms by means of the Obsessive-Compulsive Disorder Module of Structured Clinical Interview for DSM-IV and Yale-Brown Obsessive-Compulsive Symptoms Checklist. RESULTS: 46.4 % of patients treated with clozapine presented obsessive-compulsive symptoms while this occurred in 20.4 % of those with classic antipsychotic drugs (p = 0.005). In addition, 21.4 % of patients with clozapine and 13 % of those treated with classic antipsychotics presented obsessive-compulsive disorder according to DSM-IV criteria (p = 0.31). CONCLUSION: In schizophrenic patients, treatment with clozapine is associated with a higher rate of obsessive-compulsive symptoms than treatment with classic antipsychotic drugs.
Some tests and quality controls to assess the initial conditions and the working performance of a SPET system (Single Photon Emission Tomography), are described. Suitable tomographic phantoms were designed and built. We outline the methods to check MTF, stability of the photoelectric peak, centre of rotation, spatial uniformity, spatial resolution, sensitivity. NEMA tests should first be carried out to check the planar scintigraphic performance of the gamma-camera. This study allows to comprehensively evaluate the qualitative and quantitative performance of the SPET system and the correct check frequency of investigated parameters.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.