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Biomedical subjects

G Zanchetta

Publications and source records attributed to G Zanchetta.

12 recordsLinked to original sources

Optical and electro-optical derivation of the pretransitional behavior of orientational and shear viscosities in the isotropic phase of liquid crystals.

The pretransitional equilibrium properties of isotropic liquids in the proximity of the isotropic-nematic phase transition are well known and successfully modeled. Much less is known about the dynamic behavior, and in particular about the pretransitional viscosity. In this work we combine two techniques [dynamic light scattering (DLS) and electric birefringence spectroscopy (EBS)] offering complementary insights into both static and dynamic pretransitional behavior of the homologous nCB family (n-alkyl cyanobiphenyl). EBS explores the single molecule flipping dynamics retarded by a paranematic potential barrier and enables extracting the associated transport coefficient, which is found to be of Arrhenius type in the whole temperature range explored. DLS reflects the collective dynamics of correlated domains and depends on the viscous damping of the orientational order. Such a viscosity displays Arrhenius behavior only sufficiently far from the transition temperature, with deviations growing as a power law of the appropriate reduced temperature with exponents around 0.1.

Journal Article↗

Behavior of antibody profile against hepatitis C virus in patients on maintenance hemodialysis.

The prevalence of anti-hepatitis C virus (HCV) in dialysis setting is still a nonstandard datum. In particular, it is not known of the phenomenon is stable or increasing or decreasing, even in a given geographical area. We studied the behavior of anti-HCV prevalence during a 12-month follow-up in 415 hemodialysis patients treated at a single institution and belonging to a limited geographical area with standard HCV endemic. Point prevalence of anti-HCV has shown a tendency to growth linked in part of the incidence of infection, in part to new positivities in patients already on dialysis treatment. More than 50% of the new HCV-positive patients, had no history of classical parenteral transmission of the virus. These findings suggest that HCV infection is a phenomenon on the increase in dialysis units and that dialysis treatment emerges as an independent risk factor in contracting infection.

Aged↗

Heterosexual transmission of the human immunodeficiency virus: a seroepidemiological study.

The transmission of the human immunodeficiency virus (HIV) was studied in 647 subjects who presented no apparent risk factors for the infection other than having had promiscuous heterosexual relations, heterosexual relations with people with an elevated risk of infection, or heterosexual relations with people infected by human immunodeficiency virus. Thirty subjects were found to be seropositive for anti-human immunodeficiency virus antibodies. The elevated risk factors included being the habitual partner of a person at risk of infection or of a person who was infected by human immunodeficiency virus, or being the partner of a patient with acquired immunodeficiency syndrome. The transmission of the virus was verified in 13 of 284 subjects (4.57%) who had had heterosexual intercourse three or more times with persons at risk and in 16 of 101 subjects (15.84%) who had had heterosexual intercourse three or more times with persons who were seropositive for human immunodeficiency virus antibodies. No significant correlation between human immunodeficiency virus infection and a history of sexually transmitted infections, nor between human immunodeficiency virus infection and female subjects was found. These data suggest that the epidemic of acquired immunodeficiency syndrome can also spread through heterosexual relations, even if the possibility of becoming infected in this way seems at the moment limited to particular risk behaviors.

Acquired Immunodeficiency Syndrome↗

Amebic pleuro-pericarditis.

Author's report a case of visceral amebiasis in a 26 year old woman, clinically characterized by pericarditis, without any other symptoms related to organs usually interested in such disease. It was possible to reach an etiological diagnosis by indirect hemagglutination assay. The successful treatment with metronidazole confirmed the etiology "ex adjuvantibus".

Adult↗

Primary hepatic actinomycosis.

A case of primary hepatic actinomycosis is reported. Multiple liver abscesses were diagnosed in a febrile 60-year-old-man by means of non-invasive techniques such as ultrasonography, CT and radioisotope scans. The aetiology was confirmed by the unusual finding of Actinomyces israelii in anaerobic blood cultures. Other sites were not involved. Early penicillin therapy enabled surgery to be avoided.

Actinomycosis↗

[Description of a case of type E botulism in Italy].

The authors report the first documented italian case of type E botulism. The initial symptoms were typical permitting prompt diagnosis; the symptoms became severe and the patient had to be moved to intensive care. Biological tests on guinea-pigs showed the presence of type E botulin toxin in the tuna (stored in oil) which the patient had eaten 24 hours prior to admission. This tuna had been caught near the mediterranean coast of Spain several months earlier and canned at home. The authors emphasize that, even though this fish was imported, there is a danger that this intoxication could, in the future, be more widely observed.

Adult↗

[Tuberculous lymphadenitis. Apropos of a non-typical histological picture].

The case is presented of a young Somali with acute lymphadenitis. Whereas histological examination indicated abscessing granulomatous lymphadenitis, bacteriological studies revealed the presence of M. tuberculosis in the pus taken from the lymph node. Hence the aetiological diagnosis contradicted the morphological picture.

Adult↗

[On a case of autochthonous amebiasis].

Amoebiasis is usually acquired in countries where the disease is endemic. A case is presented of hepatic infection acquired indigenously. The Authors emphasized the importance of amoebic hepatic abscess as potential cause for delay in diagnosis.

Adult↗