ABSTRACT
La infección genital por el virus papiloma humano (VPH) es la enfermedad de transmisión sexual de tipo viral más común en el mundo. Loas tipos virales de alto riesgo son considerados los agentes etiológicos del cáncer de cuello uterino. El objetivo de este estudio fue analizar los genotipos del VPH en un grupo de mujeres de la ciudad de La Plata, Argentina. Se estudiaron 718 hisopados y/o biopsias cervicales correspondientes a 152 muestras normales (Pap I/II), 84 muestras clasificadas como con atipías de significado incierto (ASCUS), 100 condilomas, 279 lesiones intraepiteliales de bajo grado (LGSIL), 82 lesiones intraepiteliales de alto grado (HGSIL) y 21 carcinomas de células escamosas (SCC). La detección del genoma viral se realizó por medio de la reacción en cadena de la polimerasa (PCR), utilizando un protocolo anidado con los cebadores My 09/11 y Gp 05/06. La genotipificación del VPH se realizó por medio de la técnica de análisis de polimorfismos en la conformación de cadenas simples, utilizando solución de siembra de baja fuerza iónica (LIS-SSCP). La prevalencia general de la infección fue 75 por ciento, con 46 por ciento de muestras ADN-VPH positivas para el grupo Pap I/II, 69 por ciento para las clasificadas como ASCUS, 86 por ciento para los condilomas, 80 por ciento para los LGSIL, 98 por ciento para los HGSIL y 100 por ciento para los carcinomas de células escamosas. Los tipos virales más prevalentes fueron VPH 16 (35 por ciento), VPH 6/11 (27 por ciento cada uno), VPH 33 (6 por ciento) y VPH 18 (5 por ciento). En el grupo de mujeres con LGSIL, HGSIL y SCC el tipo viral más prevalente fue VPH 16, representando el 33 por ciento, 50 por ciento y 67 por ciento de las infecciones, respectivamente. En las mujeres con Pap I/II, ASCUS y condilomas los tipos virales más frecuentes fueron VPH 6 y 11. El grupo etario con mayor prevalencia de VPH fue el comprendido por mujeres de 21 a 30 años, acumulando el 32,2 por ciento de las infecciones totales.
Subject(s)
Humans , Argentina , Genome, Viral , Papilloma , Polymerase Chain ReactionABSTRACT
BACKGROUND: Helicobacter pylori infection is presumed to be the major causal agent of chronic active gastritis in humans. The persistent infection with this pathogen would be an important factor in the pathogenesis of peptic ulcer and also gastric cancer. METHODS: We investigated relationship between H. pylori characteristics in 42 patients with normal mucosa or gastritis with minor changes and 40 patients with mild and severe gastritis. Detection and typing of vacA and cagA genes were performed using a polymerase chain reaction method. RESULTS: The analysis of vacA prevalence and the type (S1 or S2) showed non-significant differences between the two groups studied (p > 0.05). However, cagA analysis showed highly significant differences between the groups classified as normal tissue-weak gastritis and mild-severe gastritis (p < 0.0001; OR = 8.4; CI = 3.1-22.8). CONCLUSIONS: cagA status is associated to the grade of gastritis, finding higher frequencies of H. pylori cagA+ in the moderate-severe gastritis group. These highly significant differences could make cagA status a genetic marker for disease progress.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Antigens, Bacterial/genetics , Gastritis/microbiology , Helicobacter Infections/microbiology , Helicobacter pylori/genetics , Polymerase Chain Reaction , Antigens, Bacterial/analysis , Bacterial Proteins/genetics , Bacterial Proteins/isolation & purification , Bacterial Typing Techniques/methods , DNA, Bacterial/analysis , Dyspepsia/microbiology , Dyspepsia/pathology , Gastric Mucosa/microbiology , Gastritis/pathology , Genetic Markers , Genotype , Helicobacter pylori/classification , Helicobacter pylori/pathogenicity , Nucleic Acid Amplification Techniques , Retrospective Studies , VirulenceABSTRACT
In the present study we used a simple and reliable method for HLA-DQA1 allele typing based on the single-stranded conformation polymorphism (SSCP) properties of DNA molecules obtained by PCR. The technique consists of PCR amplification of a DNA fragment comprising the second exon of the HLA-DQA1 gene, amplicon denaturation using a low ionic strength solution (LIS), and electrophoresis on a small native polyacrylamide gel, followed by a rapid silver staining procedure. In order to validate the technique and to obtain the allele patterns for the DQA1 gene, 50 cervical samples were typed using this methodology and the commercial Amplitype® HLA DQA1 Amplification and Typing kit. All the alleles detected with the kit were characterized by the LIS-SSCP approach. This procedure proved to be useful for population screening and typing of the DQA1 gene as well as for detecting new alleles or mutations in the donor-recipient molecular matching of HLA class II genes
Subject(s)
Humans , Alleles , HLA-DQ Antigens/genetics , Electrophoresis, Agar Gel , Genotype , Osmolar Concentration , Polymerase Chain Reaction , Polymorphism, Single-Stranded ConformationalABSTRACT
This study describes a fast and simple method for human papillomavirus (HPV) typing based on the polymerase chain reaction (PCR) amplification of a portion of the viral genome and single strand conformation polymorphism using low ionic strength solutions (LIS-SSCP). PCR products were obtained using My09/My11 and Gp5/Gp6 primers in a nested reaction. The band patterns corresponded to the plasmid HPV clones from HPV-6, -11, -16, -18, -31, -33 and -34. The SSCP minigels were stained with SYBR-Green II. In order to determine diagnostic applicability, 100 cervical samples were studied comprising liquid cytology and paraffin embedded biopsies from patients showing squamous intraepithelial lesions (SILs). The SSCP patterns obtained from the clinical samples and the HPV clones were similar when the same type was present. Therefore, the methodology proved to be efficient and with high reproducibility for the detection and typing of HPV in clinical samples.