Impacto del uso de antibióticos en el valor de PSA, previo a la biopsia de prostata / Impact of antibiotic use in prostate-specific antigen levels before prostate biopsy

Existen observaciones clínicas sobre el uso empírico de antibióticos en pacientes con alto nivel de PSA, sin síntomas de infecciones del tracto urinario y con indicación de biopsia prostática. El uso indiscriminado de antibióticos puede llevar a la resistencia bacteriana y diversos efectos secundarios; pero sobre todo, esto puede ser una acción médica injustificada. El objetivo de esta investigación es determinar el impacto del uso de antibióticos en los valores de PSA antes de la biopsia prostática y en la decisión de si hacer o no una biopsia prostática en pacientes con sospecha de neoplasia prostática. Estudio de casos y controles de 63 pacientes menores de 80 años de edad, con tacto rectal normal, sin infección urinaria y los valores de PSA alterado con indicación de biopsia. El grupo de control no recibió medicamento y el grupo de casos recibió cotrimoxazol (80/400 mg) cada 12 horas durante 10 días. Quince días más tarde los niveles de PSA se evaluaron de nuevo y los resultados se analizaron estadísticamente. No se encontraron diferencias significativas entre ambos grupos en relación con la edad, tacto rectal o el valor de PSA. La variación de la PSA después del uso de la terapia con antibióticos no fue significativa (p = 0,588). El uso de la terapia antimicrobiana para disminuir los valores de PSA antes de una biopsia de próstata es controvertido y no hay evidencia científica para el tratamiento de una prostatitis asintomática que pueden estar alterando los valores de PSA. Los resultados de nuestro estudio muestran la necesidad de una investigación más compleja que puede confirmar que la terapia antimicrobiana no tiene un papel terapéutico en esta situación específica y común...

There is a clinical observation about the empiric use of antibiotics on patients with high PSA level, without symptoms of urinary tract infections and with indication for prostatic biopsy. The indiscriminate use of antibiotics may lead to bacterial resistance and various others side effects as well; but above all, this may be an unjustified medical action. The objective of this research is to determinate the impact of antibiotic use on PSA values before prostatic biopsy and on the decision whether make or not a prostatic biopsy in patients suspected of having prostatic cancer. Case and control study of 63 patients younger than 80 years old, with normal rectal tact, without symptoms of urinary tract infection and PSA values altered with biopsy indication. Control group did not receive medicament and the case group received Cotrimoxazole (80/400 mg) every 12 hours for 10 days. 15 days later PSA levels were evaluated again and the results were statistically analyzed. No significant differences were found between both groups in relation to age or PSA value. The variation of the PSA after the use of antibiotic therapy was no significant (p=0,588). The use of antimicrobial therapy to decrease the values of PSA before a prostate biopsy is controversial and there isn’t scientific evidence to treat a possible asyntomatic prostatitis that may be altering the PSA values. The results of our study shows the need of a more complex research that can confirm that the antimicrobial therapy has no therapeutic role on this specific and common situation...

Identificación de factor de crecimiento vascular endotelial en células glandulares de tejido prostético maligno y benigno: Relación con la recidiva tumoral al año de la prostatectomía / Vascular endothelial growth factor in malignant and non malignant prostatic tissue: Association with tumor recurrence at one year after prostatectomy

Background: Prostate cancer (PC) is the second cause of death by cancer in men in Chile. Its behavior is so variable that it is necessary to search reliable prognostic markers. Vascular Endothelial Growth Factor (VEGF) is one of the most powerful pro-angiogenic factors. There is no agreement on its validity as a diagnostic or prognostic factor. Aim: To search for VEFG in prostatic tissue. Material and Methods: This study was performed in prostatectomy tissue coming from 41 patients with PC and 39 patients with benign prostatic hyperplasia (BPH). Specimens were studied using immunohistochemical staining for VEGF. The percentage of stained glandular cells per patient was calculated and associated with pathological diagnosis in cancer patients. Results: PC biopsies had a mean of 82% of VEGF (+) stained cells, while BPH had only 1.6% (p < 0.01). No relationship was found between the percentage of staining and recurrence at one year of follow-up in the case of PC. Conclusions: These results would rule out VEGF as a prognostic factor in this series of patients.

Identificación de factor de crecimiento endotelial vascular (VEGF) en cáncer de próstata / Identification of vascular endotelial growth factor (VEGF) in prostate cancer

El cáncer de próstata (Ca P) es la segunda causa de muerte en hombres y su comportamiento es tan heterogéneo que se ha sido necesario buscar factores pronósticos que sean fiables. Entre ellos, se está investigando la angiogénesis, proceso necesario para el crecimiento y desarrollo de metástasis del cáncer. El factor de crecimiento endotelial vascular (VEGF), es uno de los factores proangiogénicos más potentes encontrados. No se ha llegado a un consenso internacional en cuanto a su validez como factor pronóstico y tampoco hay estudios en Chile que demuestren una diferencia en su presencia entre el cáncer prostático y la hiperplasia benigna prostática (HBP). Se propuso investigar ambas relaciones en nuestro medio pues contamos con la alternativa de efectuar inmunohistoquímica a pesar de nuestras clásicas limitaciones tecnológicas. Se contaron con 66 biopsias obtenidas de cirugía prostática, de las cuales 30 eran prostatectomías radicales por cáncer prostático clínicamente localizado y 36 eran HBP obtenidas por técnica transvesical. Se les realizó inmunohistoquímica para VEGF y se obtuvo el porcentaje de marcaje de células glandulares por paciente. Se encontró una relación estadísticamente significativa en el porcentaje de marcaje entre cáncer yHBP, ya que el marcaje está prácticamente ausente en la HBP. Cuando se intento correlacionar la intensidad del marcaje con la evolución y el pronóstico de los tumores no se encontró relación entre el porcentaje de marcaje y el mal pronóstico de los tumores operados como en el caso de los cánceres que evolucionaron con recidiva bioquímica definida comoPSA mayor de 0,2 ng/ml. Como expectativas de utilidad clínica podemos plantear que en el futuro el VEGF podría tener utilidad en facilitar el diagnóstico de cáncer y un eventual uso como criterio para optar por una terapia antiangiogénica.

Introduction. Prostate cancer (PCa) is the second cause of death in men and its behavior is so versatile that it has been necessary to search for reliable prognostic factors and therapeutical targets, such as angiogenesis. The Vascular Endothelial Growth Factor (VEGF) is one of the most powerful proangiogenic factors. There is no agreement on its validity as a prognostic factor. Material and methods. A case control study was performed in patients with PCa age matched with patients with benign hyperplasia (BPH). Specimens from prostatectomies were studied using immunohistochemical staining of VEGF in prostate gland cells. The percentage of stained glandular cells per patient was calculated, and associated with diagnosis and recurrence. Prostatic Specific Antigen (PSA) over 0.2 ng/ml at 1 year after the surgery was considered as a recurrence. Results. Sixty biopsies were available, obtained by radical prostatectomy, of which 30 were PCa and 30 were BPH. PCa biopsies had a proportion of VEGF stained cells of 79.5 per cent, while BPH had a 0.86 per cent of stained cells (p<0.0001). However, association between staining percentage and recurrence of the PCa was not found. Discussion: Glandular cells in prostatic cancer show a significantly different pattern of VEGF than in non neoplasic prostates. VEGF could be useful to make PCa diagnosis in cases of dubious biopsies, through positive or negative staining for VEGF. Further studies are necessary to evaluate whether VEGF pattern correlates with aggresiveness of prostate cancer.

Brotes epizoóticos de triquinosis en dos criaderos de cerdos de la Región Metropolitana, Chile / Epizootic outbreaks of trichinosis in 2 pig farms from the Metropolitan Region, Chile

In Chile swine trichinosis has presented a progressive decreasing in the last two decades of XX century. T. spiralis pig infection descended from an average of 0,683 per 1000 in 1980-1984 to 0,315 in 1985-1989 and to 0,115 in 1990-1996. In the particular case of Metropolitan Region this decreasing has been more marked: from an average of 0,058 per 1000 in 1990-1994 to 0,003 in 1995-1999. Between the end of june 1999 and middle january 2000 in Metropolitan Region abattoirs T. spiralis was detected in 15 (4,9 percent) out of 306 swine from two pigsties located in El Monte (E.M) and Padre Hurtado (P.H) 45 and 30 km south-west from Santiago. In the same period another four pigs from the same premises were found infected in abattoirs of other regions. During inspection visits it was stated that both pig farms had deficient sanitary conditions. Phototrichinoscopy was positive in three out of five rattus norvegicus collected in E.M. In pigsty PH the examination of diaphragm samples of 25 dogs and 17 cats resulted negative. In the premises originating T. spirali infected swine the Metropolitan Environmetal Health Service Abattoirs Program carries out and epidemiological vigilance consisting in the follow-up of animls destined for slaughtering in order to initiate prophylactic actions oriented to eliminate eventual sources of trichinosis infection for human and rearing pigs