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Biomedical subjects

R Cauda

Publications and source records attributed to R Cauda.

At least 91 records · Page 5Linked to original sources
PubMed1994

Analysis of natural killer (NK) cell subsets defined by the expression of two novel surface antigens (EB6 and GL183) in AIDS and AIDS-related conditions.

In this study we analyzed the expression of EB6 and GL183, which are part of P58 molecular family that represents the putative NK receptor for MHC class I molecules, in peripheral blood lymphocytes of 60 patients with HIV infection (20 asymptomatic HIV-seropositive individuals, 20 patients with constitutional symptoms, and 20 AIDS patients) and correlated it with the level of CD4+, CD56+ cells, and the NK cell activity in order to determine a possible relation with disease progression. The absolute number (but not the percentage) of CD56+, EB6+, and GL183+ cells was significantly reduced only in AIDS patients but not in the other AIDS-related clinical conditions. On the contrary, NK cell activity was reduced in all HIV-infected patients. In a 6-month follow-up, patients with constant clinical conditions and stable CD4+ cells level showed no significant difference, either in the percentage or absolute number of EB6+ and GL183+ cells. Interestingly, dual-color fluorescence indicates that GL183 and EB6 molecules (that in normal individuals are virtually absent on CD3- NK cells) are expressed in HIV-infected individuals not only in CD56+ cells but also in CD3+ cells. This may reflect a depletion of other T cell subsets or alternatively (less likely) a specific immune response. Our data indicate that the expression of EB6 and GL183 in T and NK cells from HIV-infected patients might be relevant in the course of the disease and for the disease-associated functional defect of NK cell activity.

AIDS-Related Complex↗
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↗
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

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

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↗
PubMed1988

Ten years of brucellosis in Italy (1977-1986).

In the decade 1977-1986 the total number of cases of brucellosis recorded in Italy was 25,165. The reported cases probably reflect only a minority of the total number of the effective cases due to lack of reporting. The epidemiological and clinical features of 62 cases of brucellosis, observed by the authors are reported as a sample of the total number of cases.

Adult↗
PubMed1988

Inhibition of normal human natural killer cell activity by human immunodeficiency virus synthetic transmembrane peptides.

The inhibitory effect on normal natural killer (NK) cell activity of two synthetic peptides corresponding to amino acid sequences 735-752 and 846-860, respectively, as deduced from the amino acid sequences of HTLV-IIIB gp160, was assessed. Sequences 735-752 and 846-860 correspond to regions located within the HIV transmembrane gp41, the carboxy terminus of HIV gp160. These two synthetic peptides have been shown previously to suppress the mitogen- and alloantigen-induced normal human lymphocyte blastogenic responses. Peptides 735-752 and 846-860 conjugated to protein carriers exerted a significant inhibition on the normal NK cell activity assayed against K562 tumor target cells in an in vitro 51Cr-release cytoltoxicity assay. At variance, control peptides similarly conjugated had no effect on NK activity. Addition of exogenous recombinant human interleukin-2 (IL-2) resulted in a partial restoration of the suppression of NK cell activity exerted by both peptides. Binding experiments indicated that peptides 735-752 and 846-860 did not affect the formation of effector cell-target cell conjugates, suggesting inhibitory effect(s) subsequent to the formation of the lytic complex as one potential mechanism of the observed NK suppression. These results suggest that peptides 735-752 and 846-860 homologous to sequences within the HIV transmembrane gp41 may play an important role in the pathogenesis of the defective NK cell activity observed in patients with acquired immunodeficiency syndrome (AIDS).

Adult↗
PubMed1988

Detection of parasite related antigens associated with conglutinin binding immune complexes in patients with Schistosoma haematobium.

An ELISA assay was designed to detect the presence of parasite related antigens associated with circulating immune complexes in patients affected by urinary schistosomiasis. The assay makes use of bovine conglutinin as the immune complex recognition unit and of human anti-Schistosoma antibody as the antigen recognition unit. Using this method we showed that 10 of 15 (67%) patients with a positive polyethylene glycol assay had circulating immune complexes in which parasite antigens could be detected.

Antigen-Antibody Complex↗