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Biomedical subjects

M Mercader

Publications and source records attributed to M Mercader.

10 recordsLinked to original sources
PubMed2001

Injection of human herpesvirus-8 in human skin engrafted on SCID mice induces Kaposi's sarcoma-like lesions.

Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV-8) has been implicated in the development of Kaposi's sarcoma (KS) and several B-cell lymphoproliferative diseases. Serologic and molecular genetic association data has implicated HHV-8 as the causal agent of KS, but its role in the development of KS lesions is not understood. To examine the etiology of KS, HHV-8 was injected into normal human skin transplanted onto SCID mice. Injection of HHV-8 induced lesion formation that is morphologically and phenotypically consistent with KS, including the presence of angiogenesis and spindle-shaped cells latently infected with HHV-8. These findings suggest that HHV-8 is indeed the etiologic agent of KS, and that the virus plays an important role in initiation of this disease.

Animals↗
PubMed2001

Induction of human immunodeficiency virus 1 replication by human herpesvirus 8.

BACKGROUND: Human immunodeficiency virus 1 (HIV-1)-infected individuals are commonly infected with herpesviruses, including cytomegalovirus, herpes simplex virus, varicella-zoster virus, and human herpesvirus 8 (HHV-8, also known as Kaposi sarcoma-associated herpesvirus [KSHV]). Previous studies have demonstrated that coinfection with herpesviruses can modulate HIV-1 replication. This can occur either through direct interaction between the 2 viruses or through secondary effects resulting from the release of cellular factors in response to infection. OBJECTIVE: To investigate HIV-1 replication in the presence and absence of HHV-8. DESIGN AND METHODS: HIV-1 replication was analyzed following culture of HIV-1-infected CD4(+) T cells in the presence of HHV-8 infected B-cell lines or control, uninfected B-cell lines. To confirm and extend the results of these in vitro studies, HIV-1-infected T cells were injected into human skin transplanted onto severe combined immunodeficient mice. The human skin was also injected with purified HHV-8 or phosphate-buffered saline as a control and HIV replication measured in biopsy specimens taken 5 to 8 days later. RESULTS AND CONCLUSIONS: The results demonstrated a significant increase in HIV-1 replication in the presence of HHV-8 in both the in vitro and in vivo model systems. Although the mechanism responsible for HHV-8 induction of HIV-1 replication remains to be identified, the results indicate that these 2 viruses may interact at the molecular level in coinfected patients, resulting in increased HIV-1 viral load.

Animals↗
PubMed2000

Induction of HHV-8 lytic cycle replication by inflammatory cytokines produced by HIV-1-infected T cells.

Human herpesvirus 8 (HHV-8) is a gamma2-herpesvirus consistently identified in Kaposi's sarcoma (KS), primary effusion lymphoma, and multicentric Castleman's disease. Although HHV-8 infection appears to be necessary, it may not be sufficient for development of KS without the involvement of other cofactors. One potentially important cofactor is HIV-1. HIV-1-infected cells produce HIV-1-related proteins and cytokines, both of which have been shown to promote growth of KS cells in vitro. Though HIV-1 is not absolutely necessary for KS development, KS is the most frequent neoplasm in AIDS patients, and AIDS-KS is recognized as a particularly aggressive form of the disease. To determine whether HIV-1 could participate in the pathogenesis of KS by modulating HHV-8 replication (rather than by inducing immunodeficiency), HIV-1-infected T cells were cocultured with the HHV-8-infected cell line, BCBL-1. The results demonstrate soluble factors produced by or in response to HIV-1-infected T cells induced HHV-8 replication, as determined by production of lytic phase mRNA transcripts, viral proteins, and detection of progeny virions. By focusing on cytokines produced in the coculture system, several cytokines known to be important in growth and proliferation of KS cells in vitro, particularly Oncostatin M, hepatocyte growth factor/scatter factor, and interferon-gamma, were found to induce HHV-8 lytic replication when added individually to BCBL-1 cells. These results suggest specific cytokines can play an important role in the initiation and progression of KS through reactivation of HHV-8. Thus, HIV-1 may participate more directly than previously recognized in KS by promoting HHV-8 replication and, hence, increasing local HHV-8 viral load.

Coculture Techniques↗
PubMed2000

Conceptualizing and applying a minimum basic needs approach in southern Philippines.

This study, a collaboration between Canadian and Filipino researchers, focuses on how the national government's Minimum Basic Needs (MBN) Approach has been implemented at the local level in some selected sites in Region XI on the Philippine island of Mindanao. This case study of MBN implementation focuses on the experiences of three municipalities and three barangays (villages) within them. The research explores, through interviews and group discussions, what the mayors, technical working groups and volunteer health workers in these areas thought about MBN and how they participated in the initiative. The objectives of the study were: to explore models of MBN data utilization at the municipal and barangay levels; to understand how the MBN data guided decision-making about community priorities and resource allocation; to examine the role that community volunteers played in promoting the use of MBN data, and in community health and development activities which ensued; and to determine what factors challenged or encouraged the use of MBN data for social development at the barangay level. In all the sites, MBN had some impact, most often due to methods of concentrating information on unmet basic needs locally and making use of it in planning and project development processes. The findings show that although there is still some way to go before MBN is effectively integrated into local planning and project development, some responses to problems have been implemented and innovative projects were undertaken or being considered.

Community Health Planning↗
PubMed1999

Conventional respiratory viruses recovered from immunocompromised patients: clinical considerations.

Lower respiratory tract infection is the most common complication in the immunocompromised patient. From January 1991 to December 1995, 785 consecutive patients with suspected respiratory tract infections were studied. One hundred ninety-nine viruses were isolated from 182 (23%) of 785 bronchoalveolar lavage fluid specimens. Cytomegalovirus was isolated from 131 patients, herpes simplex virus was recovered from 31, and conventional respiratory viruses (CRVs) were recovered from 36. There were 9 influenza A viruses, 2 influenza B viruses, 7 parainfluenza viruses, 5 respiratory syncytial viruses, 5 adenoviruses, 6 enteroviruses, and 3 rhinoviruses. We identified 22 patients from whom a CRV was the only microorganism recovered; 13 patients developed pneumonia, 10 had acute respiratory failure, 5 required support with mechanical ventilation, and 5 (23%) died. In conclusion, CRVs are frequent causes of respiratory illnesses and are associated with high rates of morbidity and mortality among immunocompromised patients.

Adenoviridae↗
PubMed1998

[Practice of preventive activities in primary care and objectives of the 1993-1995 Health Plan of Catalonia].

OBJECTIVES: To find how much the detection of two factors of cardiovascular risk, over-consumption of alcohol and anti-tetanus vaccination, has been incorporated into clinical practice in the treatment of adults in the primary care reform; and to what extent the objectives on these questions of the Health Plan for Catalonia 1993-1995 were met. DESIGN: A descriptive crossover study of a sample of primary care clinical histories (PCCHs). PATIENTS: A random sample of 3000 PCCHs of patients aged 15 and over attended during 1995 in the Health Districts in Catalonia which had been in operation for over three years. MEASUREMENTS AND MAIN RESULTS: The following data were obtained from the PCCHs: patients' age and sex, whether blood pressure values were recorded, cholesterol levels, glucose levels, weight, size, tobacco habit, alcohol consumption, antitetanus vaccination and explicit documentation of diagnoses in relation to risk factors studied. The results showed that recording was above the level established in the Plan for cholesterol levels (64.4%), glucose levels (72.1%) and tobacco habit (66.5%); and slightly below, for blood pressure (57.8%) and alcohol consumption (9.6%). Among the youngest of the target population, detection was less common, especially for tobacco habit and alcohol consumption. Antitetanus vaccinations were recorded in 24.3% of the PCCHs. CONCLUSIONS: In general the objectives set in the plan have been reached. The detection of cardiovascular risk factors and over-consumption of alcohol was adequate for the target population groups established. Antitetanus vaccination is the preventive activity with the least compliance.

Adolescent↗
PubMed1991

Echinococcus granulosus: antigen characterization by chemical treatment and enzymatic deglycosylation.

Parasite antigenic fractions obtained by biochemical purification of sheep hydatid fluid were subjected to enzymatic digestion. The relative mobilities of the 5 and B antigens, before and after treatment, were analyzed by polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot. Antigenic fractions transferred to nitrocellulose were also treated with sodium metaperiodate and concanavalin A. The results indicate that antigen 5 contains a substantial amount of carbohydrates covalently linked to a polypeptide backbone, which strongly bind to concanavalin A and is removed by N-glycosidase F (PNGase F). Antigen 5 possesses complex N-linked oligosaccharides (PNGase F sensitive), without terminal N-acetyl-D-glucosamine residues (N-acetyl-D-glucosaminidase nonsensitive) and has no high-mannose oligosaccharides (endo-beta-N-acetylglucosaminidase H nonsensitive). In contrast, the antigen B of low molecular weight is not susceptible to either enzymatic digestions (PNGase F, Endo H, and N-acetyl-D-glucosaminidase) or sodium metaperiodate oxidation and it does not bind to concanavalin A. Polyclonal antibodies prepared against the two antigens reacted with the deglycosylated antigen 5 in Western blot. The dominant epitopes are, therefore, polypeptides, although the presence of carbohydrate epitopes in the native glycoproteins cannot be excluded.

Acetylglucosaminidase↗
PubMed1991

Immunochemical localization of major hydatid fluid antigens in protoscoleces and cysts of Echinococcus granulosus from human origin.

Monospecific rabbit antisera obtained through experimental immunization with previously purified proteins were used in the structural localization of two hydatid fluid antigens, antigen 5 and antigen B, in cyst membranes and protoscoleces of E. granulosus from human origin. The antigen-antibody reaction was revealed by an avidin-biotin-peroxidase technique. Antigen 5 was not evident in the laminated membrane of the cyst wall, but it was associated with the germinal membrane of the cyst wall and brood capsules. The parenchyma of invaginated and evaginated protoscoleces was heavily labelled. The tegument, the calcareous corpuscles, the suckers and the hooks did not contain antigen 5. Degenerated protoscoleces were also labelled. Antigen B localization was essentially identical to antigen 5, but degenerated protoscoleces were not recognized by anti-antigen B antiserum. Technical aspects and differences with previously published work are discussed.

Animals↗