Biomedical subjects

L Y Weckx

Publications and source records attributed to L Y Weckx.

7 recordsLinked to original sources

PubMed2006

Effect of a single tetanus-diphtheria vaccine dose on the immunity of elderly people in São Paulo, Brazil.

Epidemiological data regarding tetanus and diphtheria immunity in elderly people in Brazil are scarce. During the First National Immunization Campaign for the Elderly in Brazil in April 1999, 98 individuals (median age: 84 years) received one tetanus-dyphtheria (Td) vaccine dose (Butantan Institute, lot number 9808079/G). Inclusion criteria were elderly individuals without a history of severe immunosuppressive disease, acute infectious disease or use of immunomodulators. Blood samples were collected immediately before the vaccine and 30 days later. Serum was separated and stored at -20 degrees C until analysis. Tetanus and diphtheria antibodies were measured by the double-antigen ELISA test. Tetanus and diphtheria antibody concentrations lower than 0.01 IU/mL were considered to indicate the absence of protection, between 0.01 and 0.09 IU/mL were considered to indicate basic immunity, and values of 0.1 IU/mL or higher were considered to indicate full protection. Before vaccination, 18% of the individuals were susceptible to diphtheria and 94% were susceptible to tetanus. After one Td dose, 78% became fully immune to diphtheria, 13% attained basic immunity, and 9% were still susceptible to the disease. In contrast, 79% remained susceptible to tetanus, 4% had basic immunity and 17% were fully immune. Although one Td dose increases immunity to diphtheria in many elderly people who live in Brazil, a complete vaccination series appears to be necessary for the prevention of tetanus.

Aged↗

PubMed2005

Immunogenicity and tolerability of hepatitis A vaccine in HIV-infected children.

The immunogenicity and tolerability of hepatitis A virus vaccine was evaluated in a group of 32 children with human immunodeficiency virus (HIV) infection and 27 children with seroreversion. After 2 doses of vaccine, 100% of children experienced seroconversion with good toleration of the vaccine. There were no differences in variation of virus load between immunized HIV-positive children and a group of 31 nonimmunized HIV-positive children with similar characteristics.

Antiretroviral Therapy, Highly Active↗

PubMed2004

Varicella zoster antibodies in healthcare workers from two neonatal units in São Paulo, Brazil--assessment of a staff varicella policy.

Although frequently reported in the literature, a staff varicella policy is not standard in many hospitals even in developed countries. In the present study, we assessed varicella zoster immunity in staff from two neonatal units from hospitals in São Paulo, Brazil. Ninety-seven percent of all staff working in both units agreed to participate. A simple and cost-effective varicella policy was subsequently set up, based on costs and data from serology and a history of previous varicella infection. Our results confirm that a varicella vaccination programme can be implemented in a healthcare facility, even in developing countries.

Adult↗

PubMed2002

Immunophenotypic characterization of peripheral T lymphocytes in Mycobacterium tuberculosis infection and disease.

The cellular immune response probably plays a pivotal role in determining the clinical outcome after exposure to Mycobacterium tuberculosis. We used multi-parameter flow-cytometry to evaluate the distribution of T-lymphocyte subsets during infection and disease caused by M. tuberculosis. Samples were obtained from 71 volunteers to identify the T CD4+ and CD8+ lymphocyte numbers, and the activation plus memory/naïve phenotypes, as defined by CD38, HLA-DR, CD45RA and CD27 markers. Subjects were divided into 18 healthy volunteers without detectable reaction to purified protein derivative (PPD-), 18 health care workers with a recent conversion to PPD, 20 patients with active pulmonary tuberculosis (TBC) and 15 patients with treated TBC at 6 months of therapy. By multiple-comparison analyses, the T CD4+ lymphocyte number of the TBC group was lower than the PPD- group (P < 0.05). This difference was apparently lost after treatment. The higher and the lower number of naïve T CD4+ cells was observed in the PPD- and TBC group, respectively. CD8+ T lymphocytes were also statistically different among the four groups (P = 0.0002), lower in the TBC group (P < 0.05). CD8+ T lymphocyte activation was evaluated by the CD38 and HLA-DR surface expression. The percentage distribution of these markers was statistically different between the four groups (P = 0.0055). TBC patients had a higher percentage of CD38+ cells and mean fluorescence index, suggesting an overall increase of cell activation. These results suggest that peripheral T lymphocytes reflect cellular activation during TBC, along with possible redistribution of naïve, memory/effector and late differentiated memory/effector phenotypes in the peripheral blood after infection and disease caused by M. tuberculosis.

ADP-ribosyl Cyclase↗

PubMed1999

[Immunization schedule: dynamics and updating]

OBJECTIVES: The objective of this article is to make an analysis of the dynamics of the imunization schedule and an updating of the practical aspects of the vaccination. METHODS: The authors, based on the official recommendations, in the imunization schedule of the Infectology Department of the Brazilian Society of Pediatrics and on their experience, present practical aspects to facilitate the understanding of the dynamics of application of the calendar. RESULTS: The current calendar of the Brazilian Society of Pediatrics (SBP) is presented with a practical analysis of the vaccines BCG, hepatitis B, poliomyelitis, Haemophilus influenzae type b (Hib), DPT and triple viral, which are also part of the Calendar of the National Program of Immunizations. Besides this, they analyze two other suitable vaccines for SBP, against varicella and hepatitis A. Finally they comment on the risk of urbanization of the yellow fever and the increasing indication of vaccination against this disease in Brazil. CONCLUSIONS: The imunization schedule should be dynamic, adapted to the epidemiologic characteristics of each country or place. The presented calendar is what is now recommended by the Infectology Department of the Brazilian Society of Pediatrics (SBP).

Journal Article↗

PubMed1992

Early immunization of neonates with trivalent oral poliovirus vaccine.

Described is the evaluation in Brazil of the immune response of early immunization with trivalent oral poliovirus vaccine (TOPV). A total of 85 normal neonates from São Paulo were assigned one of the following immunization schedules: group A--one dose of TOPV at birth and subsequent doses at 2, 4, and 9 months of age; or group B--one dose of TOPV at 2, 4 and 6 months of age. Blood samples were collected sequentially from the mother at delivery, from the umbilical cord, and from the child at 2, 4, 6, 9 and 12 months of age for assay of poliovirus neutralizing antibodies. Administration of TOPV at birth, in addition to establishing immunity against poliomyelitis at an earlier stage, produced a superior immune response to poliovirus type 3. At the end of the first year, the proportion of susceptible individuals was 3.7% in group A and 25.9% in group B. When immunization against poliomyelitis is started at birth, excellent seroconversion rates are obtained from the third dose onward.

Age Factors↗

PubMed1990

Hypoglossia congenita.

Hypoglossia and aglossia are rare congenital malformations, especially when found as isolated abnormalities. In view of their usual association with other anomalies of the face, oral cavity, and distal extremities, an accurate investigation is required. We describe a 2-year-old girl with isolated hypoglossia and severe dental disease. Clinical understanding of the changes in the mechanisms of oral suction, mastication, swallowing, and speech, as well as the existing dental occlusion, requires a multidisciplinary team approach so that a more effective treatment can be administered.

Child, Preschool↗