Assessing extent of single stranded DNA damage in oral mucosal cells of patients with oral squamous cell carcinoma and its correlation with TNM staging.

Context: This study was carried out on the assumption that oral mucosal cells might show DNA damage in oral squamous cell carcinoma (OSCC). Aims: To evaluate the extent of DNA damage in oral smears of patients with OSCC and determine correlation if any of the extent of DNA damage to TNM staging of oral cancer. Settings and design: A randomized controlled study at a regional cancer centre was designed for this project. Smears were taken from lesion proper of 30 patients with OSCC and from the buccal mucosa of 30 normal healthy volunteers. Materials and methods: Collected cells were centrifuged and single-cell gel electrophoresis (SCGE) assay was performed. DNA damage was visualized under a fluorescent microscope. Statistical analysis used : Mean DNA damage levels of both the groups were measured and statistically analyzed with students' test. The extent of DNA damage was correlated with the TNM stages by employing the one way ANOVA 'F' technique. Results: High statistical significance (P < 0.0001) was found in DNA damage levels between control and study groups. A stepwise increase in DNA damage levels with high statistical significance (P < 0.005) was also found between all the TNM stages. Conclusions: Statistically significant increased DNA damage levels in OSCC patients and their correlation to clinical staging suggest that comet assay may be used effectively to assess the prognosis of OSCC.

Evaluation of DNA damage by DNA fragmentation and comet assays in experimental Toxoplasmosis with virulent strain

The outcome of toxoplasmosis is strongly dependent on the virulence of Toxoplasma gondii strains. Infection of mice with the high-virulence T. gondii RH strain induces inflammatory cytokine over production and causes their rapid death. The outcome of toxoplasmosis is strongly dependent on the virulence of Toxoplasma gondii strains. Infection of mice with the high-virulence T. gondii RH strain induces inflammatory cytokine over production and causes their rapid death. T. gondii induced apoptosis was studied, and DNA damage in spleen and peripheral blood leukocytes was evaluated by analysis of DNA fragmentation. The level of DNA damage was assessed by the extent of DNA migration in peripheral blood leukocytes using comet assay. This study was carried out on 2 groups [II and III] of mice experimentally infected with T. gondii RH tachyzoites strain, sacrificed at 2[nd] and 7[th] days post-infection [PI], respectively. In addition, none infected control group [I] was sacrificed at 7[th] day PI. Infection with high virulence T. gondii strain caused apoptosis and high level of DNA damage especially with prolongation of acute infection. Greater DNA fragmentation and intensity of apoptotic laddering was recorded in splenocytes and blood leukocytes of group III compared to those of group II. In infected groups, there was significant increase in DNA migration in comet tail in peripheral blood compared with the control group. Strongly damaged spots were significantly higher in group III than in group II. Additionally, caspase 3 immunostain showed positive reaction in splenic section of infected groups. Infection with virulent strains of T. gondii caused DNA damage with a genetic hazard to infected blood leukocytes. Apoptosis detected in splenocytes explains the rapid lethality of infected mice during acute infection

Characterization of methicillin resistant staphylococcal aureus [MRSA] isolates from mansoura university hospitals

Hospital-acquired infections due to MRSA are associated with considerable morbidity, mortality, and excess costs. Our work aimed to study the prevalence, risk factors and genotypic characteristics of MRSA isolates from patients admitted at Mansoura University Hospitals [muhs]. A total 184 of Staphylococcal aureus [SA] clinical specimens were collected from our in-patients between June 2009 to June 2010. Isolated colonies were identified in a systematic manner for selection of MRSA. Oxacillin and cefoxitin resistance tests identified MRSA that were subjected to antibiogram and resistogram. MRSA amplified genes, visualized by agarose gel electrophoresis, were analyzed by Sanger sequencing. Only 49 isolates out of the isolated strains of SA were identified as MRSA strains by cefoxitin disc diffusion test. All strains are resistant to cefoxitin, ceftriaxon, cloxacillin and ampicillin while most strains were susceptible to vancomycin. Sanger sequencing of meca gene showed 3 monographs. MRSA isolates were more from blood samples [F< 0.001] of patients above 60 years [P< 0.001], of low socioeconomic status [P< 0.001], and of >2wks duration hospital stay [P< 0.05], in icus [P< 0.001], with a previous history of hospital admission within the past year [P< 0.001] and a positive history of antibiotic use in the last 6 months [P< 0.001]. Positive family history of chronic disease [P< 0.001] or hospitalization within the last year [P< 0.05] and the presence of family member working in a clinic or a hospital [P< 0.05] were noted in MRSA-positive patients. Our data revealed an increased prevalence of multi-drug resistant MRSA isolates where PCR was of the best choice for their rapid and accurate detection. An effective infection control program should be implemented for appropriate MRSA management

Principios y aplicaciones de la reacción en cadena de la polimerasa / Principle and application of the chain reaction of the polymerase

El descubrimiento de la reacción en cadena de la polimerasa (PCR), técnica para la amplificación de ácidos nucleicos, ha tenido un enorme impacto sobre áreas diversas, tanto de la investigación básica como de la investigación clínica. Desde su descubrimiento en 1985, los informes sobre una gran variedad de aplicaciones de la PCR han recibido mucha atención en la literatura médica y científica. Esta tecnología ha demostrado tener una gran aplicabilidad para el diagnóstico de enfermedades humanas, incluyendo áreas tan diversas como enfermedades infecciosas, desórdenes genéticos y cáncer. Este artículo presenta una amplia revisión de los principios de la PCR, que incluyen conceptos genéricos que deben manejarse cuando se use o se diseñe un ensayo basado en la PCR. También se discute la aplicación de tales ensayos para el diagnóstico de desórdenes genéticos y para el estudio de enfermedades infecciosas. En los últimos 10 años ha aumentado, de manera notable, la aplicación de herramientas de la biología molecular para el diagnóstico de las enfermedades humanas. Los ensayos con sondas de ADN están, ahora, disponibles comercialmente para la detección e identificación de una gran variedad de patógenos humanos, así como para el diagnóstico de desórdenes genéticos humanos. Una manifestación del rápido crecimiento de la tecnología del ADN, ha sido el desarrollo de técnicas para amplificar secuencias específicas de ácidos nucleicos. En la literatura, han sido descritos muchos métodos, que se enumeran en la tabla i. Una comparación de estos métodos ha sido el tema de una revisión frecuente. Entre ellos se destacan la reacción en cadena de la polimerasa, como la de mayor impacto, tanto como herramienta de investigación como de diagnóstico. El objetivo de este artículo es presentar una breve revisión de los principios y aplicaciones de la amplificación de PCR, que incluyen una discusión de la selección correcta de las secuencias en blanco, el diseño de los "primer" y los medios necesarios para llevar a cabo la técnica

Marcadores pronósticos de carcinoma mamario: experiencia del hospital de oncología / Breast carcinoma prognostic cancer markers: experience in the oncology hospital

Se investigó la presencia de marcadores pronósticos en el citosol de 323 neoplasias de glándula mamaria. En 107 de éstas se cuantificaron las concentraciones de alfa-1-intitripsina y se observó que fueron más bajas en los carcinomas de pacientes con recurrencia tumoral, después de la mastectomía, en comparación con aquellos de pacientes sin recurrencia tumoral (p<0.01). Las pacientes cuyas neoplasias tuvieron valores más altos de alfa-1-antitripsina y no presentaron recurrencia tumoral mostraron una mayor probabilidad se supervivencia en cinco años comparadas con las que tuvieron valores más bajos de alfa-1-antitripsina en el carcinoma y presentaron recurrencia tumoral (p<0.0001). Aparentemente la presencia de concentraciones bajas de alfa-1-antitripsina en el carcinoma mamario, es un indicador de mal pronóstico en estas pacientes. Por otro lado, en 126 carcinomas de mama se investigó el receptor estrogénico, el grado de diferenciación y la recurrencia tumoral y se observó que en las neoplasias grado de diferenciación II con receptor estrogénico negativo, el porcentaje de pacientes con recurrencia tumoral, después de la mastectomía, fue tres veces más alto que en los casos receptor estrogénico positivo. Estos resultadosa sugieren que se puede predecir la presencia de recurrencia tumoral en las pacientes con neoplasias grado de diferenciación II y receptor estrogénico negativo.