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Biomedical subjects

A Imperato

Publications and source records attributed to A Imperato.

98 records · Page 6Linked to original sources

Benzodiazepines prevent kainate-induced loss of GABAergic and cholinergic neurons in the chick retina.

Kainic acid (50 nmol), applied intravitreally to the eyes of chicks, produces within 6 h a loss of more than 50% of biochemical markers for cholinergic and GABAergic neurons in the retina. Repeated peripheral administration of benzodiazepines, such as diazepam and clonazepam, protects from the kainate-induced loss of cholinergic and GABAergic markers in the retina. Histologically diazepam reduces the nuclear pyknosis induced by kainate particularly at the level of the amacrine cell-layer.

Animals↗

Enoxaparin reduces cerebral edemaafter photothrombotic injury in the rat.

This study investigates the effect of enoxaparin (Lovenox, Klexane), a low-molecular-weight heparin, on edema following a photothrombotic lesion using rose bengal dye in the rat. An area of cerebral ischemia was provoked in the right hemisphere of rats. Edema developed over 24 h after the lesion, as seen comparing water content of a core sample from the right hemisphere to that of a similar sample from the left hemisphere of each rat. Enoxaparin at 0. 5 mg/kg i.v. plus 2 mg/kg s.c. reduced edema 24 h after lesion induction by 32% (p < 0.01) when the treatment was started 2 h after photothrombotic insult, with maintenance doses of 2 mg/kg s.c. enoxaparin at 6 and 18 h. When the same initial treatment with enoxaparin was started 18 h after insult, there was still a significant reduction of 20% (p < 0.01) in cerebral edema. Administration of enoxaparin 18 h after insult reduced cerebral edema in a dose-dependent manner. There was no evidence of intracranial hemorrhages in any of the animal groups and when the hemoglobin content of the brain samples was assayed by the method of Drabkin, no increase in hemoglobin content was seen compared to sham-operated animals.

Animals↗

Decreased surface antigen density on lymphocytes of elderly humans.

The aim of our study was to analyze some poorly investigated and controversial aspects of senescent lymphocyte phenotype and functions. We examined 100 healthy aging individuals, divided into 4 age groups, and 30 young controls, correlating lymphocyte responsiveness to mitogenic stimulation with membrane phenotypic pattern and surface molecular densities of the main functional lymphoid markers. Stability of values in the period of study was established. No age-related differences in the parameters evaluated were detected among aging subjects. Phytohemagglutinin-induced lymphocyte proliferation was found severely impaired (about halved) in all elderly individuals with respect to controls. There was no significant difference between elderly group and controls in CD2, CD3, CD4, CD8, CD19, CD25 and HLA-DR antigen distribution. CD56 positive cell percentages were slightly decreased in the elderly groups. In apparent correlation with reduced lymphocyte responsiveness, CD2, CD3, CD4 and CD8 molecular densities, to different extents, were found relevantly (about 1 to 3-fold) lower in all aging groups than in controls. We could not ascertain if those antigens were poorly synthesized, defectively transported to membrane or shed in excess. However, we suggest that decreased surface molecular densities of antigens involved in functional processes of immune responses may be responsible for an abnormal costimulatory pattern during lymphocyte activation, leading to apoptotic rather than proliferative signals in a greater proportion of cells than normal.

Age Factors↗

Liposomal amphotericin B as first line and secondary prophylactic treatment for visceral leishmaniasis in a patient infected with HIV.

Visceral leishmaniasis has emerged in both endemic and non-endemic areas as an opportunistic infection in HIV-positive subjects. At risk for infection are HIV-positive intravenous drug abusers with a low CD4 T cell count and a high HIV viral load. In these patients, who are not always symptomatic, leishmaniasis is probably due to endogenous reactivation and often presents in an atypical fashion. Death results from uncontrolled bleeding or bacterial infections. The clinical and biological spectrum of this disease suggests that it should be included among the diagnostic criteria for AIDS. Visceral leishmaniasis responds poorly to therapy and, when responsive, the relapse rate is high. Treatment protocols and criteria to document cure after treatment have not been definitely established. Lastly, there is no effective immuno- or chemo-prophylaxis against this protozoan. We report the case of an HIV-infected patient affected by visceral leishmaniasis who was successfully treated with liposomal amphotericin B given both as first line and as secondary prophylactic therapy. The patient has remained disease-free for 26 months after his first remission whereas, to our knowledge, almost all immunocompromised patients relapse within 12 months.

AIDS-Related Opportunistic Infections↗