Una propuesta rápida y económica para detectar el virus de papiloma humano por PCR a partir de muestras cervicales con reactivo desnaturalizante / A rapid and economic option for human papillomavirus detection by PCR in cervical samples with denaturing reagent

Trabajos han demostrado la utilidad de la captura híbrida II (CH II®) en la detección del virus de papiloma humano de alto riesgo oncogénico (HR-HPV) como método de tamizaje primario para detección de cáncer de cuello uterino, así como las bondades de la PCR que permite acceder a métodos de tipificación viral. Por ello el objetivo fue detectar el genoma del HPV por PCR a partir de muestras de CH II® cien veces diluidas. Estudio transversal en 141 muestras cervicales de mujeres con citología normal y anormal que concurrieron al IICS, UNA. Las muestras fueron procesadas por CH II® y almacenadas con reactivo desnaturalizante a -80ºC. Luego, las muestras fueron diluidas 100 veces con agua destilada y posteriormente procesadas por PCR. Se detectó HPV en 51% y 43% de las muestras analizadas por CH II® y PCR, respectivamente. Diecisiete de 23 muestras positivas por CH II® con carga viral relativa baja fueron negativas por PCR. Esto podría deberse a la degradación del material. Además, 6 muestras negativas por CH II® fueron positivas por PCR sugiriendo presencia de infección con tipos virales no incluidos en CH II® . Estos resultados sugieren que es posible realizar la detección de HPV por PCR en muestras procesadas por CH II® previa dilución. Esta propuesta rápida, sencilla y económica, minimiza el riesgo de perder el material genético en la extracción y permite acceder a métodos de tipificación viral que podrían contribuir con datos sobre tipos de HPV circulantes para realizar una vigilancia en la era post-vacunal.

Studies havedemonstrated the usefulness of the hybrid capture II (CHII) in thedetection of oncogenic high risk human papillomavirus (HR-HPV) asaprimaryscreeningmethod for detection of cervical cancer, as well as the benefits of PCR that allows accessto viral typing methods. The objective was todetect HPV by PCR from cervical samplesprocessed by CH II.It was a cross-sectional study including141cervicalsamples ofwomenattendingtheIICS,UNA. Thesampleswereprocessed by CH IIand storedwithdenaturing reagent at-80ºC.Then,theywere diluted 100 times with distilled water andsubsequently processed by PCR. HPV was detected in 51% and 43% of the samples analyzed by CH IIand PCR respectively. Seventeen of 23 positive samples by CH IIwith relatively low viral load were negative by PCR. This could be due to degradation ofthe material. In addition,sixnegative samples by CH IIwere positive by PCR suggestingthe presence of infection with HPV types not included in CH II. These results suggestthat it is possible to detect HPV by PCRfrom samples processed by CH IIprior dilution.This is a quick, easy and economic alternative which minimizes the risk of losing thegenetic material in the extraction process,and allows access to viral typing methods thatcouldprovide data aboutcirculating HPVtypesto carry out surveillance in thepost-vaccine era.

Flow cytometric DNA ploidy, p53, PCNA, and c-erbB-2 protein expressions as predictors of survival in surgically resected gastric cancer patients.

In order to determine retrospectively the impact of some cytometric and immunohistochemical parameters on the overall survival of gastric cancer patients treated with surgery alone, paraffin-embedded tumor samples from 137 gastric carcinoma patients undergoing curative resection from 1987-1993 were analyzed by flow cytometry (FCM) and immunohistochemistry (p53, c-erbB-2, and PCNA expression). FCM-derived parameters were DNA ploidy and fraction of S-phase cells (SPF). Multiple regression analysis was applied to determine the prognostic significance of the conventional clinicopathologic findings together with the flow cytometric and immunohistochemical parameters on overall survival. When all parameters were entered simultaneously into the Cox regression model, stage and DNA ploidy (DNA index >1.35) clearly emerged as the only independent prognostic factors. When the stages were analysed separately, the independent prognostic factors resulted DNA ploidy in early stages (I-II) and grading in stage IIIA tumors. For stage IIIB tumors, no independent prognostic factor was found. These results indicate that the DNA ploidy pattern is a valuable predictor of survival in curatively resected gastric cancer patients, especially when less advanced tumors are taken into consideration.

Monitoring of antimicrobial prophylaxis in general surgery.

The incidence of infections in general surgery is related to different factors. Cost-benefit analysis of antimicrobic prophylaxis is positive, even though incorrect use may be even dangerous (development of resistance and/or superinfections, for instance). The authors report data on a study concerning a total of 316 patients divided into two series, who had antimicrobic prophylaxis before a surgical operation. 274 patients out of 316 (or 86.7%) had an ultra-short (one-shot-only) or short (<24 hours) prophylaxis, 42 (13.3%) standard (>24 hours). The operations performed were classified following class of contamination, i.e. I (clean), II (potentially contaminated), III (contaminated). Antibiotics used were ceftizoxime, cefepime, ceftriaxone, piperacillin and gentamicin in combination. A total of 16 postoperative infections was observed (5%); 11 of these 16 belonged to class III operations. Escherichia coli and Staphylococcus aureus were isolated in most of the infected wounds. The data confirm what is reported in the literature. The authors conclude that a preoperative single-shot 3rd or 4th generation cephalosporin reduces the incidence of wound infections in clean and clean-contaminated surgery.

Immunochemotherapy of advanced colorectal cancer with alpha-interferon and 5-fluorouracil. 1. Toxicological studies.

Twelve patients with advanced colorectal cancer were subjected to alternating cycles of treatment with low immunomodulating doses of recombinant alpha-interferon (alpha IFN) + 5-fluorouracil (5FU) or with 5FU alone. Hematological, biochemical and physical evaluation of the patients showed that alpha IFN + 5FU cycles were well tolerated like 5FU alone, except for modest and transient fever following alpha IFN administration. At hematological nadir (day 15-18 of each cycle) lymphocytopenia and granulocytopenia were more pronounced during alpha IFN + 5FU than 5FU cycles. No difference was found for platelet nadir. At the beginning of each cycle complete leukocyte recovery was observed in all cases. Platelet recovery was also complete, although counts were higher after alpha IFN + 5FU than after 5FU alone. Clinical results showed 1 complete remission, 1 partial remission, 5 stable disease and 5 progressive disease. These data point out that low doses of alpha IFN can be safely associated with 5FU. However further studies are required to establish the possible therapeutic value of alpha IFN-mediated immunomodulation for immunochemotherapy of colorectal cancer.