PubMed Health⌕ Search

Biomedical subjects

A Barelli

Publications and source records attributed to A Barelli.

33 records · Page 2Linked to original sources
PubMed1992

AZT-induced mitochondrial myopathy.

Histochemical, electron microscopy and biochemical studies were performed on muscle biopsy specimens from 11 AIDS patients treated with zidovudine. A peculiar association of structural abnormalities and mitochondrial dysfunction was found. Focal cytochrome c oxidase (COX) deficiency was evident in muscle sections from 9 patients, 8 of whom had received long-term treatment while one had been treated for 1 month only. Electron microscopy showed changes in number, size and structure of mitochondria. Biochemical studies proved partial COX and succinate cytochrome c reductase (SCR) deficiency in 4 patients; one patient had only reduced SCR activity. Our data confirm that AZT therapy can cause toxic myopathy with mitochondrial dysfunction.

Adult↗
PubMed1991

B cell activation during HIV-1 infection. II. Cell-to-cell interactions and cytokine requirement.

This study examined the mechanisms underlying the intense activation of HIV-1-specific B cells observed in peripheral blood of HIV-1-infected subjects. Spontaneous in vitro synthesis of anti-HIV-1 antibodies, as well as total Ig production, were dramatically reduced by accessory cell, but not T cell removal. This fall was counteracted by addition of rIL-6, but not other cytokines, to monocyte-depleted cultures; moreover, antisera against IL-6 suppressed spontaneous anti-HIV-1 antibody synthesis in a dose-dependent manner. Although IL-6 apparently sustained HIV-1-specific B cell activation, no increase in serum IL-6 levels was observed; PBMC from seropositive subjects did not produce increased amounts of IL-6 in vitro, compared to seronegative controls, both spontaneously and in the presence of LPS stimulation; finally, no constitutive expression of IL-6 gene could be documented in freshly isolated PBMC. These findings indicate that IL-6 may play a central role in HIV-1-specific B cell activation in seropositive patients, and further stress the importance of this cytokine during HIV-1 infection.

B-Lymphocytes↗
PubMed1991

B-cell activation during HIV-1 infection. III. Down-regulating effect of mitogens.

Spontaneous in vitro production of HIV-1-specific antibodies, a hallmark of infected subjects, is often down-regulated by the addition of pokeweed mitogen. We observed that a decrease in such ongoing anti-HIV-1 antibody synthesis could also be induced in cultures from most patients by addition of phytohemagglutinin and Concanavalin A, but not by Epstein-Barr virus, a selective B-cell mitogen. In most cases, this down-regulatory effect of mitogens was evident within the first 24 h of culture. The observed mitogen-associated decrease in spontaneous antibody synthesis was prevented by treating peripheral blood mononuclear cells with agents inhibiting non-major histocompatibility complex-restricted cytotoxic activity or by adding third-party cells to the cultures. In most cases, the mitogen-induced effect was also counteracted by removal of T lymphocytes or CD8+ T-cell sub-population. These findings recall a similar phenomenon observed in normal subjects following intentional immunization, and indicate that mitogen-induced down-regulation of spontaneous in vitro anti-HIV-1-antibody production most probably occurs through a lectin-dependent cytotoxic effect on activated B cells.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1991

Serial multimodality-evoked potentials in severely head-injured patients: diagnostic and prognostic implications.

OBJECTIVES: To assess the prognostic reliability of multimodality-evoked potentials and to evaluate the diagnostic implications and define the limits of these evoked potentials. SETTING: An ICU in a university hospital. DESIGN: Prospective clinical study. PATIENTS: Seventy-three severely head-injured patients aged 10 to 75 yrs. METHODS: Serial recording of brainstem auditory-evoked potentials and somatosensory-evoked potentials between days 1 and 21 after trauma. Comparison between evoked potential findings and prognosis, along with clinical data. RESULTS: Considering the single recordings of both brainstem auditory-evoked potentials and somatosensory-evoked potentials, the accuracy of prognostication in predicting a bad outcome was good only for severely abnormal brainstem auditory-evoked potentials. Serial brainstem auditory-evoked potential recordings and simultaneous recordings of brainstem auditory-evoked potentials and somatosensory-evoked potentials proved to be good prognostic indices in predicting a favorable outcome. Brainstem auditory-evoked potentials correlated well with brainstem reflexes and with pupil asymmetries but did not correlate with Glasgow Coma Scale scores. CONCLUSIONS: Serial recording and the use of a multimodality approach provided the best prognostic capabilities. The main diagnostic implications were: a) the possibility of detecting brainstem compression by means of brainstem auditory-evoked potentials before the appearance of pupil abnormalities; b) the usefulness of brainstem auditory-evoked potentials in monitoring brainstem function in patients undergoing high-dose barbiturate therapy. The main limitations of evoked potentials were the occurrence of peripheral acoustic damage, the electromagnetic sources of artifacts in the ICU, and the administration of ototoxic drugs.

Adolescent↗
PubMed1987

[Bile salts, copper, ceruloplasmin in meal test].

Biliary salts determination after meal test is an useful liver function test. We evaluated both biliary salts and copper-ceruloplasmin after meal test in different liver diseases. Copper-ceruloplasmin determination does not seem to be useful in the diagnosis of liver diseases because copper has only partial hepatic clearance.

Bile Acids and Salts↗
PubMedDate not supplied

[Brain mapping of middle latency auditory potentials in normal subjects].

The MLRs of 20 normal hearing adults were recorded by cerebral mapping. In regard to the Pa and Na waves, it is suggested that two different generation sites exist because of the different spatio-temporal distribution of the waves over the scalp. It is demonstrated that amplitudes measured by the "grand average" technique are constantly lower than those obtained with the manual determination, and they conclude that manual determination represents the most reliable method in order to calculate waves amplitude. Finally, it is suggested that, due to the different generation sites for Pa and Na waves and to the uneven distribution of the Na wave over the scalp, Pa amplitude should be measured from the baseline and not from the Na negative deflection. Moreover, in 14 cases, when one ear was stimulated the Pa wave obtained at most recording points was significantly larger than the one recorded contralaterally.

Acoustic Impedance Tests↗