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Biomedical subjects

L Ortona

Publications and source records attributed to L Ortona.

At least 73 records · Page 4Linked to original sources
PubMed1993

An emerging opportunistic infection in HIV patients: a retrospective analysis of 11 cases of pulmonary aspergillosis.

Invasive pulmonary aspergillosis usually occurs in patients with severe granulocytopenia or defects of cell-mediated immunity secondary to cytotoxic chemotherapy or high-dose corticosteroids, but it is an unusual opportunistic infection in patients with AIDS. Eleven cases of Aspergillus pulmonary disease were diagnosed in HIV-infected patients from January 1985 to December 1992, in the Department of Infectious Diseases of the Catholic University. Four patients had invasive pulmonary aspergillosis, six probable pulmonary invasive aspergillosis and one allergic bronchopulmonary aspergillosis. Fiberoptic bronchoscopy with bronchoalveolar lavage was confirmed to be an useful tool for the diagnosis of pulmonary aspergillosis in AIDS patients. The response of aspergillosis to therapy, either amphotericin B or itraconazole, has usually been poor. It is possible to speculate that the longer survival of AIDS patients and the latter development of other functional immunological abnormalities related to HIV infection may allow the appearance of opportunistic infection, such as pulmonary aspergillosis, different from those more often observed.

AIDS-Related Opportunistic Infections↗
PubMed1993

Diagnosis of Pneumocystis carinii pneumonia: specificity and sensitivity of polymerase chain reaction in comparison with immunofluorescence in bronchoalveolar lavage specimens.

DNA amplification by the polymerase chain reaction (PCR) is a promising method for the detection of Pneumocystis carinii in immunosuppressed patients. The sensitivity and specificity of the PCR technique has been assessed in comparison with the immunofluorescence method (IF) on bronchoalveolar lavage fluid (BALF). Results correlated in 43 (78.8%) of 52 cases studied. P. carinii PCR gave positive results with BALF from all 32 patients found to have P. carinii pneumonia (PCP); IF gave positive results with 26 of them. PCR was more sensitive and as specific as IF. However, at the present time, we do not believe that it is clinically useful for detection of P. carinii in BALF samples. P. carinii DNA amplification by PCR should be reserved for testing IF-negative BALF samples from patients judged clinically to have PCP.

Adult↗
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↗
PubMed1991

A seroepidemiological survey on Leishmania infantum infection.

Findings from a seroepidemiological survey of Leishmania infantum (LI) infection are presented. Among residents in the province of Rome, 2.7% (4.4% in the city of Rome and 1% in the suburbs) of 374 adults were positive for specific LI antibodies in indirect haemoagglutination studies. Among 217 adult residents of Caltanissetta province (Sicily), 4.1% were positive for LI antibodies (4.2% in Caltanissetta city and 4% in the suburbs). Serological tests for LI antibodies were also carried out on stray dogs captured in Rome. 5% of them resulted positive. Our findings show that LI infection is moderately present in both Rome and Caltanissetta, the latter being an area of known endemicity. According to our data, LI infections are usually asymptomatic: none of the positive subjects had a history of visceral leishmaniasis, and none of the seropositive dogs showed any sign or symptom correlated to leishmaniasis.

Adolescent↗
PubMed1991

Meningococcal meningitis in Italy: 1887-1986.

In Italy three epidemic peaks of meningococcal meningitis have occurred reflecting pandemic recrudescence of the disease. The seasonal distribution of the disease is similar in the epidemic or non-epidemic periods. There is no significant difference in the regional distribution of the disease. The disease is more prevalent among young males. The prevalent serogroup of Neisseria meningitidis is C. There has been a decrease in resistance to sulphonamides and an increase to rifampin among the isolated strains.

Adolescent↗
PubMed1991

Synthetic peptides corresponding to sequences in HIV envelope gp41 and gp120 enhance in vitro production of interleukin-1 and tumor necrosis factor but depress production of interferon-alpha, interferon-gamma and interleukin-2.

Patients with human immunodeficiency virus (HIV) infections have aberrant production of a number of lymphokines and monokines. Envelope glycoproteins are believed to be important in HIV pathogenesis and may influence the production of these cytokines. Therefore, synthetic peptides corresponding to amino acid sequences 735-752 and 846-860 of glycoprotein gp41 and to amino acid sequence 304-328 of gp120 were investigated for their abilities to affect the production of the following cytokines by normal peripheral blood mononuclear cells in the presence of appropriate inducers: interferon (IFN)-alpha, IFN-gamma, interleukin (IL)-1, IL-2, and tumor necrosis factor (TNF). In contrast to cells and inducers alone (or in the presence of a control peptide), gp41 or gp120 synthetic peptides were able to depress the production of IFN-alpha, IFN-gamma and IL-2. In contrast, these peptides produced an elevation of the production of IL-1 and TNF. The effect of the gp41 peptides was more marked than that of gp120 peptides in most cases. These studies indicate that these HIV envelope glycoproteins may be directly responsible for aberrant lymphokine and monokine production in patients infected with this virus and therefore may be at least partially responsible for the pathogenesis of AIDS.

Cytokines↗
PubMed1990

Risk of AIDS in HIV seroconverters: a comparison between intravenous drug users and homosexual males.

A multicentre cohort study was conducted in Italy to estimate the risk of developing AIDS in 261 intravenous drug users and 89 homosexual males for whom the seroconversion period was known. Four years after HIV seroconversion, AIDS incidence, estimated by Kaplan-Meier survival technique, was 13.8% for intravenous drug users and 16.2% for homosexual males; the difference was not statistically significant. These findings suggest that four years after seroconversion the risk of developing AIDS in HIV seropositive intravenous drug users is no higher than that of subjects who acquired HIV infection through sexual contact.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Role of polymorphonuclear leukocytes in infection by retroviruses with emphasis on the human immunodeficiency virus.

Neutrophil function is an integral part of the host defense against multiple pathogens. Through phagocytosis and production of toxic substances, these short lived cells aid in the effective elimination of invading microorganisms such as bacterial and fungal targets. Viral infections, and in particular those of the retroviral type, appear to suppress the immune response through direct cytotoxic destruction of immune cells or alteration of the biochemical interactions that are essential for eradicating the foreign agent. In this report, we describe abnormalities of neutrophil number and function consequent to HIV and other retroviral infections. A myriad of mechanisms, either alone or in concert may explain the underlying aberrations.

Animals↗
PubMed1990

Inhibition of lymphokine-activated killer activity during HIV infection: role of HIV-1 gp41 synthetic peptides.

Lymphokine-activated killer (LAK) activity was analyzed in 31 human immune deficiency virus 1 (HIV-1)-infected patients. It was found to be reduced in all groups of patients, being more pronounced in those with acquired immune deficiency syndrome (AIDS) and AIDS-related complex compared to HIV-1-seropositive, asymptomatic individuals. Only high doses of interleukin-2 were able to restore LAK activity comparable to that of normal controls. In addition, HIV-1 gp41 synthetic peptide sequences 735-752 and 846-860 were able to significantly inhibit normal LAK activity at all the effector:target ratios tested. HIV-1-positive serum and the supernatant fluids from cultured peripheral-blood mononuclear cells from HIV-1-infected patients had the same inhibitory effect on normal LAK activity. These data provide evidence that (1) LAK activity appears to be impaired during the course of HIV-1 infection and (2) HIV-1-positive serum and HIV-1 components could exert a profound inhibition of this functional activity.

Adult↗
PubMed1989

Immunological alterations associated with recurrent herpes simplex genitalis.

Immunological studies on 12 patients with culture-proven frequently recurrent herpes simplex genitalis were performed. All the patients were evaluated at three time intervals, initially without lesions and/or within 24 hr of lesion onset (acute illness); Days 5-7 from onset and after healing (convalescence); and between recurrences (quiescence). During the first 24 hr of lesions there was a decreased number of helper (CD4+) and an increased number of suppressor/cytotoxic (CD8+) cells with a resultant decrease in the CD4/CD8 ratio. An increased proportion of CD8+ cells coexpressing the CD11 marker (suppressor cells) was noted and correlated with a low proliferative response to HSV-2 antigens. Both the NK cells (CD16+) and the NK cell activity versus HSV-2-infected targets and the K562 cell line were decreased. Five to seven days after onset the number of CD8+ cells remained increased, although the expression of CD11 marker was decreased, indicating that the majority of CD8+ cells were cytotoxic (i.e., CD8+CD11-). At this time, the lymphoproliferative response to HSV-2 antigens and NK cell activity increased, correlating both with the number of CD16+ cells and with the expression of HLA-DR on this subset. In the interval between two recurrences, no significant alteration in any of the above immunological parameters was observed.

Adult↗
PubMed1989

The natural history of HIV infection in intravenous drug users: risk of disease progression in a cohort of seroconverters.

A multicentre cohort study was carried out to estimate the incidence of AIDS and HIV-related conditions in newly infected intravenous drug users (IVDU). The enrollment criteria included the identification of the seroconversion time. Two hundred and five subjects entered the study, and were followed for a mean of 26 months. Twelve subjects developed clinical AIDS over a 4-year period. The actuarial incidence of AIDS estimated by Kaplan-Meier survival technique was 17.8% by 4 years since seroconversion. The risk of developing AIDS increased significantly after 24 months from seroconversion. Relatively small figures accounted for the lack of statistical association between the risk factors investigated and the disease status.

AIDS-Related Complex↗
PubMed1989

Radiological changes and circulating immune complexes in patients with urinary schistosomiasis.

The degree of infection and the urographic picture was correlated to the presence and level of circulating immune complexes (CICs) in 69 patients affected by urinary schistosomiasis. Patients were divided into 2 groups: those eliminating less and those eliminating more than 25 eggs/10 ml of urine. Radiological changes in the urinary tract were present in 67% of patients, the most frequent finding being single or multiple filling defects in the bladder. CICs were present in 39 patients. A positive correlation was found between the presence and level of CICs and the output of Schistosoma haematobium eggs, as well as between the presence of CIC and single or multiple filling defects of the bladder. Our findings indicated that CICs were present in patients with urinary schistosomiasis, but the different incidence in patients with a large egg output and radiological filling defects suggests a possible pathogenic role only in the earlier phase of the infection.

Adult↗