Biomedical subjects

E Visconti

Publications and source records attributed to E Visconti.

At least 19 recordsLinked to original sources

PubMed1995

Genetic variability in different Pneumocystis isolates from man and rats.

To gain further insight into the genetic variability between different isolates of Pneumocystis carinii of rat and human origin, we sequenced three DNA regions from the mitochondrial rRNA gene, the 5S rRNA gene and the dihydrofolate reductase gene (DHFR) of microorganisms isolated from three different immunosuppressed rat sources and from one HIV + patient with P. carinii pneumonia. Some point mutations and deletions were found among rat isolates in two regions (mitochondrial rRNA gene and 5S rRNA gene). Nucleotide sequence variations in these conserved regions support the hypothesis of the existence of several Pneumocystis strains infecting the same host species.

Animals↗

PubMed1993

Haemopoietic CD34+ progenitor cells are not infected by HIV-1 in vivo but show impaired clonogenesis.

We evaluated the role of CD34+ bone marrow progenitor cells in vivo, in the pathogenesis of AIDS-related haematological abnormalities. The clonogenic activity of CD34+ cells from seven patients with HIV-1 infection, without bone marrow involving opportunistic infections or neoplasms, was assessed in semisolid cultures. The number of CFU-GM was significantly reduced as compared to the controls (P = 0.017), independently from myelotoxic therapy, while the number of BFU-E was not. The presence of retroviral sequences in CFU-GM colonies from four patients and in the total population of CD34+ cells from six patients with advanced stage HIV infection was investigated using the polymerase chain reaction. The presence of HIV-1 sequences was also searched for in a purified suspension of CD34+ cells after 3 weeks liquid culture. All these cells were always HIV-1 negative, while viral sequences were always detected in bone marrow mononuclear cells from these and other patients. The number of HIV-1 DNA copies decreased with increasing enrichment. At most 1:10,000 CD34+ cells are infected in vivo. Other mechanisms than direct viral infection of progenitor cells must account for the defective haemopoiesis in HIV-1 infected patients.

Adult↗

PubMed1993

Simple and rapid two-step polymerase chain reaction for diagnosis of Pneumocystis carinii infection.

Two amplification steps were made to detect Pneumocystis carinii DNA by polymerase chain reaction (PCR). pAZ102-E and pAZ102-H (standard PCR), pAZ102-L2 (sense), and pAZ102-E (antisense) (two-step PCR) were used as primers. The amplification products were analyzed by ethidium bromide. After the two-step PCR, ethidium bromide detected all samples positive by oligohybridization after one amplification step. Our two-step PCR is a rapid, cost-effective, and clinically suitable method for the detection of P. carinii infection.

Bronchoalveolar Lavage Fluid↗

PubMed1992

Antibody production in infants born to HIV-1-infected mothers.

Naturally occurring antibodies to polysaccharide antigens of pathogens commonly isolated from HIV-1-infected subjects were analyzed in serially collected sera of children born to seropositive mothers. Purified polysaccharides from type 14 Streptococcus pneumoniae, group C Neisseria meningitidis, type b Haemophilus influenzae, glucomannoprotein from Candida albicans and diphtheria toxoid antigens were used in an ELISA test to assess antibody levels. A significant rise of anti-pneumococcus antibody titres was noticed both in HIV-1-infected and in non-HIV-1-infected children aged 18 months or more. Anti-C. albicans and anti-group C N. meningitidis antibodies were elevated only in HIV-1-infected children older than 12 months. Anti-type b H. influenzae antibodies remained at low titres in both groups. Anti-diphtheria toxoid antibodies, analyzed as a model of humoral response to a protein antigen, were similar in both groups of HIV-1-infected and noninfected children.

Antibodies, Bacterial↗

PubMed1992

[The clinical and immunological efficacy of a combination of immunoglobulins and an oral polyvalent antibacterial vaccine in recurrent respiratory infections].

Ninety patients with a history of recurrent upper and lower respiratory infections were randomized into three groups of 30 patients each. Group 1 was treated with i.m. immunoglobulins and oral polyvalent bacterial vaccine, group 2 with vaccine only, while group 3 was not submitted to prophylactic treatment. During and after prophylaxis, all three groups were evaluated for frequency of recurrent respiratory infections and the most relevant immunological parameters. In groups 1 and 2, a significant reduction of minor and major upper and lower respiratory infections was observed compared to the control group. Patients treated with Ig+vaccine or vaccine alone showed an increase of IgG2 subclasses and CD4 lymphocytes and positive changes of delayed skin tests. These findings confirm the results of previous preliminary studies which had shown the polyvalent bacterial vaccine to be useful for the reduction of recurrent infections of the respiratory tract, especially during the winter. Further studies will have to be carried out in order to identify the precise mechanism by which antigen stimulation with the oral vaccine improves the immunological response of the respiratory tract.

Administration, Oral↗

PubMed1990

Granulomatous prostatitis induced by capsule-deficient cryptococcal infection.

A 59-year-old man with prostatism, in otherwise good health, was treated with transurethral prostatectomy and ketoconazole. At microscopic examination of the prostatic tissue he had acute and chronic prostatitis with granulomatous lesions, in the center of which capsular-deficient cryptococcal organisms were demonstrated. The patient was well without evidence of systemic or local infection at 22 months. The differential diagnosis of granulomatous prostatitis is discussed.

Cryptococcosis↗

PubMed1989