[The natural history of sperm cleareance after vasectomy]. / La historia natural del aclaramiento de espermatozoides en el semen tras la vasectomía.

OBJECTIVE: To study the time required to obtain a negative sperm analysis after vasectomy. MATERIAL AND METHODS: We reviewed 239 consecutive vasectomies performed between september 1998 and september 1999. All of them were done in an ambulatory basis. Follow up interval was 41-853 days (mean 144, median 104). The first semen analysis was requested between 1 and 6 months after the surgical procedure. If the sample still showed spermatozoa, then a new one was requested every two months. Probability of becoming azoospermic was studied with Kaplan-Meier curves. RESULTS: Persistent spermatozoa could be found in 31 patients (13%) at the end of follow-up. Despite having a positive semen analysis, 10 patients (4.2%) discontinued medical visits. Time required to obtain a negative sperm count ranged from 58 to 362 days (mean 133, median 99). The probability of being azoospermic 200 and 260 days after vasectomy was 80-90% respectively. A total of 328 semen analysis were requested (range 1-4, mean 1.37, median 1) CONCLUSIONS: A minimum of 200 days (6.6 months) are needed to clear all the spermatozoa in semen after vasectomy in 80% of our patients. Requesting the first semen sample 7 months after vasectomy is cost-effective, reducing unnecesary medical visits and increasing the rentability of this test.

La historia natural del aclaramiento de espermatozoides en el semen tras la vasectomía / The natural history of sperm cleareance after vasectomy

OBJETIVO: Estudiar el tiempo necesario para obtener un seminograma negativo tras la vasectomía. MATERIAL Y MÉTODO: Revisamos 239 vasectomías consecutivas durante un año. Todas ellas fueron realizadas de forma ambulatoria. El tiempo de seguimiento fue de 41-853 días (media 144, mediana 104).El primer seminograma fue solicitado entre 1 y 6 meses tras la intervención. A los pacientes que presentaron espermatozoides en la primera muestra de semen, se les solicitó una nueva muestra cada dos meses hasta que el seminograma fuese negativo. La probabilidad de azoospermia fue estudiada mediante curvas de Kaplan-Meier. RESULTADOS: Al final del periodo de seguimiento, 31 pacientes (13%) seguían teniendo espermatozoides en el seminograma. A pesar de ello, 10 pacientes (4,2%) dejaron de acudir a la consulta. El tiempo requerido para obtener un seminograma negativo osciló entre 58 y 362 días (media 133, mediana 99). La probabilidad de quedar azoospérmico a los 200 y 260 días tras la vasectomía, fue del 80 y 90% respectivamente. Se realizaron un total de 328 seminogramas (rango 1-4, media 1,37, mediana 1).CONCLUSIONES: Se necesita un mínimo de 200 días (6,6 meses) para que el 80% de nuestros pacientes queden azoospérmicos. Solicitar el primer seminograma 7 meses tras la vasectomía es rentable, reduciendo el número de visitas médicas innecesarias e incrementando la rentabilidad de esta prueba (AU)

OBJECTIVE: To study the time required to obtain a negative sperm analysis after vasectomy. MATERIAL AND METHODS: We reviewed 239 consecutive vasectomies performed between September 1998 and September 1999. All of them were done in an ambulatory basis. Follow up interval was 41-853days (mean 144, median 104). The first semen analysis was requested between 1 and 6 months after the surgical procedure. If the sample still showed spermatozoa, then a new one was requested every two months. Probability of becoming azoospermic was studied with Kaplan-Meier curves. RESULTS: Persistent spermatozoa could be found in 31 patients (13%) at the end of follow-up. Despite having a positive semen analysis, 10 patients (4.2%) discontinued medical visits. Time required to obtain a negative sperm count ranged from 58 to 362 days (mean 133, median 99). The probability of being azoospermic 200 and 260 days after vasectomy was 80-90% respectively. A total of 328 semen analysis were requested (range 1-4, mean 1.37, median 1). CONCLUSIONS: A minimum of 200 days (6.6 months) are needed to clear all the spermatozoa in semen after vasectomy in 80% of our patients. Requesting the first semen sample 7 months after vasectomy is cost-effective, reducing unnecesary medical visits and increasing the rentability of this test (AU)

Prostate specific antigen density. Is there a role for this parameter when screening for prostate cancer?

The objective of this paper is to validate prostate specific antigen (PSA) density (PSAD) routine use to enhance PSA specificity in men with normal digital rectal examination and intermediate PSA values. It is a retrospective study of 235 men from a prostate cancer (PCa) screening program. All of them presented PSA values between 4 and 10 ng/ml, normal digital rectal examination, and a transrectal ultrasound (TRUS) guided biopsy available (PSA>/=4 ng/ml as the sole criterion for biopsy). Multivariate analysis failed to demonstrate higher PSAD values in men with PCa. PSAD cutoff points higher than 0.07 ng/ml per cc were considered as unacceptable, with less than 95% sensitivity. When a cutoff point of 0.15 was considered, as many as 30.6% of the cancers were missed. In conclusion we cannot recommend the use of this parameter for the above mentioned purpose.Prostate Cancer and Prostatic Diseases (2001) 4, 146-149.

Biochemical and hematological changes in low-level aluminum intoxication.

The aim of this study was to investigate the biochemical and hematological changes in patients on routine hemodialysis treatment when they were accidentally exposed to moderately high serum aluminum concentrations during a period of time of less than four months. We studied the changes in biochemical and hematological measurements in 33 patients on dialysis in our hospital before and during the exposure to about 0.85 pmol/l of aluminum in dialysis water due to a malfunction of the reverse osmosis system of water purification. Patients showed a decrease in the hemoglobin concentration from 115+/-12.4 g/l to 108+/-12.2 g/l (p=0.026) and in the mean corpuscular hemoglobin concentration from 5.15+/-0.22 to 5.02+/-0.30 mmol/l (p=0.014). Ferritin was decreased from 243+/-192 microg/l to 196+/-163 microg/l (p=0.047) and transferrin saturation from 0.20+/-0.06 to 0.15+/-0.07 (p=0.004). Biochemical measurements related to calcium-phosphate metabolism did not change. Otherwise, all patients showed an increase in serum aluminum from 0.56+/-0.44 to 1.63+/-0.52 micromol/l (p<0.001). No differences were detected in serum aluminum between patients receiving and not receiving oral aluminum salts. Even moderately high aluminum concentrations maintained during a short period of time could produce significant hematological alterations and a depletion of body iron stores before clinical manifestations were evident.

Rifampicin causes false-positive immunoassay results for urine opiates.

The treatment of tuberculosis usually includes the antibiotic rifampicin, especially in patients with concomitant human immunodeficiency virus infection. Some of these patients are in withdrawal therapy for drug abuse. When opiate screening is carried out in patients receiving rifampicin, false positive results are detected with the kinetic interaction of microparticles in solution method. We evaluated this interference in a Cobas-Integra analyzer and found a 12% cross-reactivity of rifampicin for antibiotic concentrations ranging from 0.19 to 6.08 mumol/l (156 to 5000 micrograms/l). This effect is not explained by the colour of the rifampicin solutions. Calculations assuming first order kinetics of elimination show that more than 18 hours after a single oral dose of 600 mg of rifampicin, a false positive result for opiates could be obtained. This indicates that the risk of a false positive result must always be considered when urine samples from these patients are analyzed.

Urinary enzyme activities in patients treated with gold and other antirheumatic drugs.

We have studied 48 rheumatoid arthritis (RA) patients treated with nonsteroidal antiinflammatory drugs (NSAIDs), except salicylates, in 31 of whom parenteral gold was associated as therapeutic agent. In order to assess initial tubular involvement, the activities of some urinary enzymes were measured: N-acetylglucosaminidase (NAG, EC 3.2.1.30), microsomal amino-peptidase (MAP, EC 3.4.11.2) and gamma-glutamyltransferase (GGT; EC 2.3.2.2). Results were compared with a control group of 51 subjects of similar age, with no rheumatic symptoms and normal renal function. Both groups of patients (31 with gold therapy and 17 without) showed a significantly increased activity of NAG in urine, but the increase was greater in those treated with gold. MAP and GGT were not elevated significantly in either group. There was no correlation, however, between the increase of NAG and the cumulative dose of gold. NAG, MAP and GGT activities in serum yielded no relevant information. All the usual tests of renal function were also normal. Determination of NAG in urine may be regarded as a sensitive test, capable of detecting selective involvement of renal tubular cells, whose final diagnostic and prognostic significance merits further evaluation.

Effects of long-term treatment with indomethacin on renal function.

The prolonged effects (42 days) of indomethacin treatment on the renin-angiotensin-aldosterone axis, renal hemodynamics, and renal excretory function in humans were studied. Indomethacin produced a 41% sustained depression in the 24-hour excretion of prostaglandin E2 and a mild (7%) decrease in inulin clearance but did not affect the clearance of p-aminohippurate, the 24-hour excretion of sodium and potassium, or the basal values of plasma aldosterone; however, it decreased the basal values of renin and prevented the stimulated (3 hours of walking) responses of plasma renin activity and plasma aldosterone. Indomethacin also produced a decrease in both the diuretic and saluretic response to furosemide and in the renal ability to concentrate urine. The indomethacin-induced hyporeninism and hypoaldosteronism were more pronounced when the subjects were receiving a sodium-restricted diet. This finding indicates that prolonged administration of anti-inflammatory drugs induces chronic hyporeninism and hypoaldosteronism. Prolonged treatment with indomethacin also produced some of the symptoms of a syndrome of hypoprostaglandinism, such as decreased plasma renin activity, plasma aldosterone, and urinary prostaglandin E2 in association with increases in plasma potassium levels and diastolic pressure.

Dose-related hemodynamic and renal effects of dopamine in septic shock.

offstudied hemodynamic and renal effects of increasing the dosage of dopamine (DP) by 5 micrograms/kg X min, in 7 patients with peritonitis and clinical findings of septic shock, all of whom were already receiving variable dosages of DP. Stroke index (SI) (p less than .01), except in 3 cases, and mean arterial pressure (p less than .01) were significantly elevated without significant increases in HR and systemic vascular resistance index (SVRI). Changes in mean pulmonary artery pressure (MPAP) and pulmonary wedge pressure (WP) were insignificant (less than 3 mm Hg). Renal response showed augmentation of diuresis (p less than .01), inulin clearance (Cin) (p less than .05), and fractional excretion of sodium (FENa) (p = .02) without significant changes in either paraminohypurate clearance (Cpha) or filtration fraction. There was no correlation between hemodynamic or renal changes and initial dosage of DP. We conclude that increasing the DP dosage in septic shock patients may be useful even when the patient is already receiving large doses. Increased natriuresis was not due to changes in plasma renal flow.