Biomedical subjects

L Mecocci

Publications and source records attributed to L Mecocci.

9 recordsLinked to original sources

PubMed1999

Archetypal and rearranged sequences of human polyomavirus JC transcription control region in peripheral blood leukocytes and in cerebrospinal fluid.

Two forms of human polyomavirus JC (JCV) genome are known based upon the structure of the transcriptional control region (TCR) of the virus: the archetypal form, which is commonly detected in urine, and the rearranged form, which was first detected in brain tissue from progressive multifocal leukoencephalopathy (PML) patients. The latter actually includes a group of TCR variants that, relative to the former, are characterized by various deletions and/or duplications. The aim of this study was to establish whether or not a correlation exists among the TCR type, the spreading of the virus within the host and its ability to cause PML. JCV TCR sequences from peripheral blood leukocytes (PBL) and cerebrospinal fluid (CSF) obtained from various groups of patients were compared. JCV with archetypal TCR was detected in CSF and PBL specimens from patients without neurological disorders or who eventually received a diagnosis of a non-PML neurological disorder. Rearranged TCR sequences were detected in all the CSF and PBL specimens from PML patients. The high similarity observed between the TCR structure detected in PBL and CSF specimens from individual patients could strengthen the hypothesis that PBL has a role in spreading JCV to the brain. Moreover, heterogeneous TCR patterns have been shown in individual PBL specimens from PML patients. This supports the hypothesis that, in PBL, JCV may replicate and undergo rearrangements of the TCR. The detection of JCV DNA by PCR in CSF independently from PML, although rare, could suggest that this assay is not sufficient for a virological diagnosis of PML. Further studies are required to assess the usefulness of quantitative assays or TCR typing in combination with PCR for diagnostic purposes.

Base Sequence↗

PubMed1997

Correlation between plasma HIV-1 RNA levels and the rate of immunologic decline.

To determine the influence of HIV-1 replication on immunologic decline and clinical outcome, we quantified the HIV-1 plasma viral load in 20 patients at different times over a mean period of 10.8 months. Quantitation was performed by branched DNA signal amplification (bDNA) and p24 antigenemia. Immunologic status was assessed through beta 2-microglobulin and CD4+ cell count determinations. CD4+ cell decline was expressed as a slope of the regression line constructed by the logarithms of CD4+ cell count observations. Mean values of plasma viral load were correlated with CD4+ cell decline and mean beta 2-microglobulin levels. Significant correlation was observed between plasma viral load quantified by the bDNA technique and CD4+ cell decline. No significant correlation was observed between plasma viral load quantified by p24 antigenemia and CD4+ cell decline. A significant correlation was observed between plasma viral load and beta 2-microglobulin levels. Immunologic decline was better predicted from HIV-1 RNA levels than from the CD4+ cell count. Significantly higher plasma viral load was observed in patients who had clinical progression of HIV-1 infection. Thus, HIV-1 plasma viral load quantified by a highly reliable technique such as bDNA showed that the immunologic decline is closely related to HIV-1 RNA replication.

Anti-HIV Agents↗

PubMed1997

Human herpesvirus-6 reactivation in a longitudinal study of two HIV-1 infected patients.

After primary infection, human herpesvirus-6 (HHV-6) persists in latent form and can be reactivated in immunocompromised subjects. A longitudinal study of HHV-6 infection was carried out in two HIV-1 seropositive patients to provide in vivo evidence of HHV-6 reactivation. Concomitant with a significant rise of anti-HHV-6 IgG detected by IFA, a transient increase of HHV-6 viral load was shown in PBLs by PCR. During HHV-6 reactivation it was also identified either cell-free HHV-6 by PCR in plasma or IgM antibody titers. HHV-6 reactivation was followed by a temporary decrease in CD4+ count and by a progressive dramatic loss of CD4+ during the following 18 months. HHV-6 strain characterization by PCR demonstrated that first patient (MM) initially showed the B variant, followed by reactivation and persistence of the A variant, while in the second (SG) only the A variant was detected. The evidence of HHV-6 reactivation suggests its involvement in immunologic damage underlying the disease.

AIDS-Related Opportunistic Infections↗

PubMed1993

Electrophysiological study of neurologically asymptomatic HIV1 seropositive patients.

EEGs, brainstem auditory evoked potentials (BAEPs) and auditory event-related potentials (ERPs) were recorded from 33 individuals infected with the human immunodeficiency virus, type 1 (HIV1+ patients: 13 CDC Class II or III; 20 Class IV). All were neurologically asymptomatic, non-demented, and had a past history of intravenous drug abuse. Sixteen age- and sex-matched normals and 10 HIV1- former drug addicts served as controls. Half of the HIV1+ and HIV1- subjects displayed mild EEG anomalies and, except for one HIV1+ patient, BAEPs were normal in both groups. ERPs were normal in all HIV1- subjects but anomalous (longer latencies of components P2, N2, P3; reduced amplitude of P3) in 9 HIV1+ patients (27%), the incidence of such anomalies being higher for Class IV than Class II/III patients. Auditory ERPs proved the most sensitive and specific of these electrophysiological procedures in detecting subclinical central nervous system involvement in HIV1 infection.

Adult↗

PubMed1992

[Appendicitis: microbial interactions and new pathogens].

The Authors present an exhaustive review on microbial agents of appendicitis by means of literature and personal research data. Thus, a detailed analysis is made on common autochthonous agents and their pathogenetic interactions and on less common exogenous bacterial, viral, mycotic, protozoan and helminthic agents with emphasis to the role of Yersinia enterocolitica. In fact this bacterium seems responsible for 3% to 8% of cases in accordance with literature and personal research data (more detailed, Y. enterocolitica has been isolated in 3.8% of 208 inflamed appendices from both pediatric and adults surgical florentine patients). At the end, the pathogenetic role of "new" other bacteria, like Buttiauxella agrestis, Aeromonas hydrophila, Arizona, Streptococcus lactis, is debated on the basis of a personal study.

Acute Disease↗

PubMed1991

[Intestinal microbial pathology in AIDS. A clinical case series].

Microbial isolates from 60 diarrheic AIDS patients hospitalized to the Infectious Disease Division of Careggi hospital (Florence) are described. Clinical, microbiological and diagnostic features of each case are discussed with emphasis to some rare or underestimated entities in Europe: Campylobacter laridis bacteremia, Whipple-like disease by atypical Mycobacteria, Schistosoma mansoni proctocolitis. Results regarding newly AIDS-related microorganisms are also stressed.

Acquired Immunodeficiency Syndrome↗

PubMed1990

[Pseudo-Whipple disease caused by atypical mycobacteriosis in AIDS: a clinical and electron microscopic study of 2 cases].

The Authors focus on two cases, studied by electron and light microscopy, of Whipple-like disease caused by atypical mycobacteria in AIDS. Differential characteristics between the cases and classical Whipple's disease are analyzed with regard to the diagnostic and therapeutical peculiarities of Mycobacterium avium-intracellulare infection which accounts for over 80% of atypical mycobacterial infections in AIDS. In this regard the Authors stress the role of histological findings of pale blue striated histiocytes as a marker of Mycobacterium avium-intracellulare infection.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

Quantitation of HCV viraemia by branched DNA signal amplification in patients treated with alpha-interferon--a longitudinal study.

Using bDNA, the plasma viral load trend of HCV-infected patients undergoing IFN therapy was analyzed. Nine patients were enrolled, each assigned to one of three groups, based on IFN response as determined by ALT and AST level trend. HCV was genotyped using DEIA. Each patient's clinical stage was determined by liver biopsy analysis. In nonresponding patients elevated viral loads and biochemical parameters were observed. These values were not influenced by IFN treatment. In relapsed patients the cessation of IFN treatment increased viral load; this was associated with a rise in ALT and AST values. In responders ALT and AST levels remained normal; viral load was low. Patients with elevated HCV viral load showed a worsening in their liver histology during the follow-up period. These results confirm that plasma viral load is a good marker of biochemical change and disease progression.

Adult↗

PubMedDate not supplied

[Amebic liver abscess: 2 imported cases].

Two imported cases of amebic liver abscess are discussed with regard to laboratory, diagnostic and therapeutic peculiarities. The diagnostic role of ultrasonography and especially of specific serology is stressed, whereas in therapeutic terms, the efficacy of medical approach alone is emphasized even when complications until yesterday surgically treated occur.

Adult↗