RESUMO
A very high prevalence of multiple sclerosis (MS) has been reported in some Western European and North American countries. The few surveys of MS epidemiology in South America reveal lower prevalence rates, implying that susceptibility varies between distinct ethnic groups, thus forming an important determinant of the geographic distribution of the disease. The objective of this study is to review MS prevalence estimates in different Latin American and Caribbean countries. We reviewed surveys of regional MS prevalence from 1991 to 2011. Sources included an online database, authors' reports and proceedings or specific lectures from regional conferences. We obtained a total of 30 prevalence surveys from 15 countries, showing low/medium MS prevalence rates. Both the number and the quality of prevalence surveys have greatly improved in this region over recent decades. This is the first collaborative study to map the regional frequency of MS. Establishment of standardized methods and joint epidemiological studies will advance future MS research in Latin America and the Caribbean.
Assuntos
Esclerose Múltipla/epidemiologia , Região do Caribe/epidemiologia , Coleta de Dados , Notificação de Doenças , Etnicidade , Geografia , Humanos , América Latina/epidemiologia , Prevalência , América do Sul/epidemiologia , Raios UltravioletaRESUMO
BACKGROUND: Both clinical and laboratory evidence in exposed seronegative (ESN) individuals to human HIV-1 has suggested the existence of mechanisms of natural resistance to the infection. A 32 base-pair deletion in the gene that codes for the CCR5, which is the main coreceptor for HIV-1, confers a high degree of resistance to HIV-1 infection. However, the genotype Delta32/Delta32 is present only in 2-4% of Caucasoid ESN individuals suggesting the existence of other mechanisms of protection. Mutations different from Delta32 have also been proposed as playing a role in resistance/susceptibility to this infection. OBJECTIVE: To screen for different mutations along the entire coding region of the ccr5 gene that can potentially explain the persistent seronegativity in a group of ESN individuals. STUDY DESIGN: Of a total of 86 individuals analyzed for Delta32 mutation by the PCR technique, 36 scored HIV seropositive (SP) and 50 were ESN. The entire group of ESN individuals was screened for other mutations in the ccr5 gene by single strand conformational polymorphism (SSCP) and DNA sequencing. RESULTS: The frequency of the mutant allele Delta32 was 4% (4/100) for ESN individuals and 4.2% (3/72) for SP individuals. The homozygous mutant genotype (Delta32/Delta32) was found in only 2% (1/50) of ESN individuals, but in no SP individuals. The heterozygous genotype was found in 8.3% (3/36) of SP individuals and in 4% (2/50) of ESN individuals. The differences in the allelic and genotypic frequencies among the groups were not statistically significant. A comparison between the observed and the expected genotypic frequencies showed that they were significantly different for the ESN group, suggesting a protective, yet indirect effect of the mutant genotype. CONCLUSIONS: The screening of the entire coding region of the ccr5 gene in all ESN did not revealed no other mutations that could account for resistance to HIV-1 infection. Although the CCR5 molecule is the most important coreceptor for HIV-1, mutations in this gene do not account for most of the cases of natural resistance to this virus that have so far been reported.
Assuntos
Infecções por HIV/genética , Soronegatividade para HIV/genética , HIV-1 , Receptores CCR5/genética , Alelos , Frequência do Gene , Infecções por HIV/imunologia , Soronegatividade para HIV/imunologia , Humanos , Imunidade Inata , MutaçãoRESUMO
PIP: In Colombia, health workers obtained a nasopharyngeal wash from 103 infants aged less than 12 months hospitalized for acute lower respiratory infection (ALRI) at the General Hospital of Medellin during April 1994 to April 1995 so researchers could determine the frequency of ALRI caused by respiratory syncytial virus (RSV) in hospitalized children. Immunofluorescence detected RSV infection in 43 (41.7%) patients. The presence of the following signs and symptoms allowed a clinical diagnosis of a viral infection: rhinorrhea, prolonged expiration, expiratory wheezing, interstitial infiltrates, and hyperinflation on chest radiographs as well as negative tests for 3 or 4 acute phase reactants. The physicians initiated antibiotic therapy (for 1-3 days) in 12 cases (27.9%) based on acute phase reactant findings who actually had an RSV infection. When the physicians learned that the laboratory confirmed RSV infection, they stopped antibiotic therapy. Antibiotics were continued in 16 (37.2%) other RSV infected infants, all of whom were less than 2 months old, due to mixed pneumonia (viral and bacterial). 39.4% of RSV-infected children whose clinical findings strongly suggested RSV received no antibiotics. None of these children or other ALRI patients with a viral disease suffered complications. They required less hospitalization time--since no further diagnostic tests were needed--than ALRI patients with a bacterial infection. Admissions for both ALRI and RSV infection peaked during November to January. RSV incidence peaked in January (23.3%). The leading reasons for hospitalization were pneumonia and bronchiolitis. These findings show that RSV diagnosis is useful and it lessens the indiscriminate use of antibiotics.^ieng
Assuntos
Países em Desenvolvimento , Infecções por Vírus Respiratório Sincicial/diagnóstico , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções Respiratórias/diagnóstico , Distribuição por Idade , Colômbia/epidemiologia , Diagnóstico Diferencial , Feminino , Hospitalização , Humanos , Incidência , Lactente , Masculino , Infecções por Vírus Respiratório Sincicial/complicações , Infecções Respiratórias/complicações , Infecções Respiratórias/epidemiologia , Fatores de Risco , Distribuição por Sexo , Taxa de SobrevidaRESUMO
The present study reports of the geographic distribution of 2,878 cases of uniformly classified malignant lymphomas and of 2,349 similar cases from the literature. Data on histological entities are compared with the geographic and socio-economic characteristics of the regions where they preferentially occur. The results provide three patterns in lymphoma distribution: small cell lymphocytic lymphomas are frequent among populations of European extraction and in farming rather than industrial regions. Lymphomas derived from cells of the germinal center are seen preferentially in so-called "underdeveloped countries", and large cell (immunoblastic) lymphomas appear rather characteristic of industrial areas. Besides genetic influences (rare chronic lymphocytic leukemia (CLL) in Asia as compared to Europe), the results suggest environmental cofactors in the pathogenesis of malignant lymphomas. CLL is more frequent in areas with rather low-dose chronic toxic influences such as from the use of fertilizers and pesticides in farming. Germinal center cell lymphomas tend to occur more frequently in countries with nutritional and hygienic deficiencies with frequent infectious diseases. Large cell high malignancy lymphomas apparently prefer highly industrialized regions with pollution of water supplies by more toxic and immunosuppressive substances.
Assuntos
Poluição Ambiental , Linfoma não Hodgkin/induzido quimicamente , Linfoma não Hodgkin/epidemiologia , Clima , Poluentes Ambientais/toxicidade , Europa (Continente)/epidemiologia , Geografia , Humanos , Linfoma não Hodgkin/patologia , México/epidemiologia , Fatores Socioeconômicos , América do Sul/epidemiologia , Estados Unidos/epidemiologiaRESUMO
Surgical specimens were obtained from a patient who had had life-threatening paracoccidioidomycosis 5 years previously. Residual lesions were found in the mesenteric lymph nodes; there were areas of caseous necrosis separated from the surrounding tissue by a fibrous capsule made of connective tissue. Abundant P. brasiliensis cells, many of which appeared degenerated, were observed in the necrotic material. Primary isolation was possible only under the microaerophilic conditions offered by fluid media kept stationary at 36 degrees C. Cultures in solid media were obtained after serial passages and gradual accommodation of the strain to aerobic incubation. It is apparent that P. brasiliensis yeast cells can become accustomed to reduced oxygen tension in the tissues. In this way, they are able to withstand the passing of time without completely losing their viability.
Assuntos
Calcinose/microbiologia , Fungos/isolamento & purificação , Linfonodos/microbiologia , Técnicas Microbiológicas , Paracoccidioides/isolamento & purificação , Paracoccidioidomicose/microbiologia , Adolescente , Adulto , Meios de Cultura , Humanos , Masculino , Oxigênio/metabolismo , Paracoccidioides/metabolismoRESUMO
Las enfermedades humanas causadas por Zigomicetos (Ficomicetos) pueden dividirse en dos grupos, las Mucormicosis y las Entomoftoramicosis. La Mucormicosis es causada por hongos del orden Mucorales y se observa en condiciones de bajas defensas del huesped. La Entomoftoramicosis, causada por hongos del orden Entomoftorales incluye la variedad Basidiobola, causada por el Basidiobolus haptosporus y la Conidiabolae cuyo agente es el Conidiobolus (Entomophthora) coronatus; a diferencia de los Mucorales este grupo puede afectar a pacientes sanos. Se presenta un segundo caso colombiano de Entomoftoramicosis naso-facial (Rinoficomicosis) observada en un paciente moreno de 36 anos procedente del Choco, lugar de procedencia del primer caso observado en el pais y cuyos aspectos clinicos e histopatologicos se resumen brevemente
Assuntos
Entomophthora , Mucormicose , MicosesRESUMO
Four hundred and fifty two cases of Hodgkin's disease (H.D.) were studied in Medellin, Colombia, following the Rye histological classification: The relative frequency of H.D. was 2.3% for all malignancies and 34% for the solid lymphoreticular tumors. The percentage of H.D. in children as compared with adults was 27%, which is higher than usually reported. The age curve of incidence was bimodal with a first high peak at age 5--9 years and a lower second peak between 15--25 years. Males predominated mainly in children, 4.5--1. The epidemiological pattern for H.D. in our area generally corresponded with the Type I recently described for developing countries; but a high frequency for Nodular Sclerosis in children, with unusual anatomical localizations, more severe clinical manifestations, and poorer prognosis seems to indicate complex factors in the etiopathogenesis of the disease in the same geographical area.