RESUMEN
Phenotypic variability in pathogenic fungi has long been correlated with virulence, but specific genetic and molecular mechanisms are only recently being unraveled. Fungal morphogenesis, reflecting the expression of several regulated genes, and the capacity of the rising forms or phases to cause disease has been focused on at the XIVth Congress of the International Society for Human and Animal Mycology. Three experimental models of pathogenic fungi have been discussed. In Cryptococcus neoformans, phenotypic variability or switching represents controlled and programmed changes rather than random mutations. Evaluated phenotypic traits were the capsular polysaccharide, cell and colony morphology and virulence. In the dimorphic Paracoccidioides brasiliensis, the serine-thiol proteinase from the yeast phase cleaves the main components of the basal membrane, thus being potentially relevant in fungal dissemination. In Candida albicans, relationships between adhesion proteins and those of lymphocytes and neutrophils are related to fungal pathogenicity. Regulation of the directional growth of hyphae and its tropic responses are correlated with the invasive potential of C. albicans.
Asunto(s)
Candida albicans/patogenicidad , Cryptococcus neoformans/patogenicidad , Paracoccidioides/patogenicidad , Candida albicans/genética , Candida albicans/crecimiento & desarrollo , Secuencia de Carbohidratos , Cryptococcus neoformans/genética , Cryptococcus neoformans/crecimiento & desarrollo , Humanos , Datos de Secuencia Molecular , Morfogénesis , Micosis/microbiología , Paracoccidioides/genética , Paracoccidioides/crecimiento & desarrollo , VirulenciaRESUMEN
INTRODUCTION: We evaluated an intervention program for Mexican-American women to increase Pap smear and mammography screening. METHODS: The three-year intervention included the presentation of role models in the media and reinforcement by peer volunteers. We used a two-community (intervention and comparison) pre-post test design. Activities were targeted to a mainly Spanish-speaking, poverty-level, immigrant population. Pre- and postintervention screening rates were based on independent random samples of Mexican-American women 40 years and older. RESULTS: Women reported a 6% absolute increase in Pap smear use similar to the 7% increase in the comparison community. Both communities experienced large but similar increases in recent mammography use (17% and 19%). Adjusting for differences in demographic factors, intervention and comparison changes remained identical. CONCLUSIONS: Our peer intervention failed to accelerate the secular trend in cancer screening low-income Mexican-American women. Likely, promotional activities were too diffuse and the comparison community was contaminated with similar interventions. Strong social and market forces make it difficult to measure the effect of a specialized intervention on cancer screening rates.
Asunto(s)
Promoción de la Salud/métodos , Mamografía/estadística & datos numéricos , Americanos Mexicanos , Prueba de Papanicolaou , Frotis Vaginal/estadística & datos numéricos , Adulto , Anciano , Estudios Transversales , Escolaridad , Femenino , Humanos , Persona de Mediana Edad , Grupo Paritario , Pobreza , TexasRESUMEN
The activity of mitochondrial aldehyde dehydrogenase (ALDH2) was tested by isoelectric focusing of hair root extracts from 50 Chachi Indians (Ecuador). Quality of extracts and the intactness of cytoplasmic and mitochondrial enzymes were ascertained by assaying of phosphoglucomutase (PGM) and malate dehydrogenase (MDH) in the same extracts. Three of the 39 successfully assayed Chachi Indian samples showed virtual absence of the ALDH2 band on the isoelectropherogram, and the control enzymes were stained normally in these subjects. These data confirm the existence of a mitochondrial ALDH deficiency among South American Indians. The molecular origin of the ALDH2 deficiency in this population is unknown.
Asunto(s)
Aldehído Deshidrogenasa/deficiencia , Indígenas Sudamericanos , Adolescente , Adulto , Aldehído Deshidrogenasa/metabolismo , Niño , Preescolar , Ecuador/etnología , Femenino , Cabello/enzimología , Humanos , Focalización Isoeléctrica , Malato Deshidrogenasa/metabolismo , Masculino , Persona de Mediana Edad , Mitocondrias/enzimología , Fosfoglucomutasa/metabolismoRESUMEN
Phylogenetic associations among six closely related South American felid species were defined by changes in protein-encoding gene loci. We analyzed proteins isolated from skin fibroblasts using two-dimensional electrophoresis and allozymes extracted from blood cells. Genotypes were determined for multiple individuals of ocelot, margay, tigrina, Geoffroy's cat, kodkod, and pampas cat at 548 loci resolved by two-dimensional electrophoresis and 44 allozyme loci. Phenograms were constructed using the methods of Fitch-Margoliash and neighbor-joining on a matrix of Nei's unbiased genetic distances for all pairs of species. Results of a relative-rate test indicate changes in two-dimensional electrophoresis data are constant among all South American felids with respect to a hyena outgroup. Allelic frequencies were transformed to discrete character states for maximum parsimony analysis. Phylogenetic reconstruction indicates a major split occurred approximately 5-6 million years ago, leading to three groups within the ocelot lineage. The earliest divergence led to Leopardus tigrina, followed by a split between an ancestor of an unresolved trichotomy of three species (Oncifelis guigna, O. geoffroyi, and Lynchailuris colocolo) and a recent common ancestor of Leopardus pardalis and L. wiedii. The results suggest that modern South American felids are monophyletic and evolved rapidly after the formation of the Panama land bridge between North and South America.
Asunto(s)
Gatos/genética , Electroforesis en Gel Bidimensional , Filogenia , Alelos , Animales , Frecuencia de los Genes , Variación Genética/genética , Isoenzimas/genética , América del SurRESUMEN
A high prevalence of asthmalike symptoms was noted among patients of Puerto Rican descent attending Beth Israel and North Central Bronx Medical Centers in New York City, as compared with other ethnic groups. An evaluation of family and medical histories, pulmonary function data, and alpha 1-antitrypsin phenotypes was undertaken in such Puerto Rican patients and control subjects without asthma. The patients showed a higher proportion of MS and MV phenotypes. All the patients in both MM and variant phenotype groups, with the exception of four MM patients, had features indicative of asthma, with labile airway obstruction, and elevated serum immunoglobulin E and eosinophil levels. The latter was significantly higher in the patients with variant phenotypes than in MM patients. Patients with alpha 1-antitrypsin variants also had much shorter smoking histories as compared with the MM group, and all reported histories of asthma in first-degree relatives, as compared with 66% among the MM patients. We conclude that there is an increased incidence of asthma among Puerto Ricans in New York City, and that the antitrypsin variant phenotypes (specifically S and V) play a role in this incidence and its expression.
Asunto(s)
Asma/etnología , Hispánicos o Latinos/genética , alfa 1-Antitripsina/genética , Femenino , Variación Genética , Humanos , Incidencia , Masculino , Ciudad de Nueva York/epidemiología , Fenotipo , Prevalencia , Puerto Rico/etnología , Pruebas de Función Respiratoria , Fumar/etnologíaRESUMEN
Four patients developed group A streptococcal wound infections shortly following orthopedic surgery. Two of these patients developed scarlet fever which provided an early indication of the presence of a streptococcal epidemic. A single antigenically characteristic strain of group A streptococci was recovered from the wounds of all four patients and from the anus of one surgeon who had participated in the surgery on three of the patients.