Results of transition zone biopsy in black and white men with suspected prostate cancer

OBJECTIVES: To determine whether biopsy-detectable transition zone tumors are more common in black than in white men with suspected Stage T1c and T2 prostate cancer. METHODS: We performed a prospective study of transition zone prostate biopsy (TZ biopsy) in 1 78 black and 261 white men who had not undergone previous prostate biopsy and in 61 black and 65 white men who had undergone one benign sextant peripheral zone prostate biopsy (PZ biopsy). RESULTS: The mean age of the 239 black and 326 white study patients was 68.6+/-7.4 and 67.2+/-7.2 years, respectively (P = 0.02), the mean prostate-specific antigen (PSA) was 8.4+/-7.4 and 6.4+/-5.4 ng/mL, respectively (P = 0.003), and the mean PSA density was 0.20+/-0.23 and 0.16+/-0.16 ng/mL/mL, respectively (P = 0.006). Overall, cancer was diagnosed by TZ biopsy only in 7 black men (3%) and in no white men (0%) (P = 0.003). However, cancer detection with a TZ biopsy only was not significantly different in the black and white men when controlled for age, PSA, or PSA density (P>0.90). A TZ biopsy only detected cancer in 1% of patients who had not undergone prior PZ biopsy and in 2% of patients who had undergone prior PZ biopsy. Of the seven cancers detected with TZ biopsy, six (86%) had a Gleason score of 2 to 6. CONCLUSIONS: Prostate cancer detection with a TZ biopsy only is not common and when controlled for confounding variables is the same in black and white men. The preferential use of TZ biopsies in black men is not warranted, and the low diagnostic yield argues against routine use of the biopsy technique in men of either race.     

Irradiation of clinically uninvolved cervical lymph nodes

Of 402 patients with cancers of the oral cavity, oropharynx, and supraglottic larynx treated at Stanford between 1957 and 1972, 164 had clinically uninvolved cervical lymph nodes prior to the initiation of radiation therapy. Lymph node metastases developed later in 38 per cent of patients with primary oral cavity carcinomas who were treated with interstitial radium implants alone. No late cervical lymph node involvement was found in those patients who received high dose external irradiation to at least the primary site and first echelon lymph nodes. Lymph node failures were ultimately noted in 20 of the 140 patients (14 per cent), who received partial or complete neck irradiation, but 18 of these occurred in patients with uncontrolled primary lesions, suggesting that re-seeding of cervical lymph nodes had taken place rather than failure of the initial irradiation to control subclinical metastases. Our present policy is to treat the primary lesion and adjacent lymph nodes with high dose megavoltage techniques, combined with interstitial irradiation if possible. Bilateral supplemental inferior neck radiation ports are added for patients with advanced primary neoplasms and for those with clinically involved cervical lymph nodes. All other patients undergoing radiation therapy for stage T1 primary lesions and clinically negative necks also receive ipsilateral low neck irradiation. In addition, cervical lymph nodes are electively irradiated when the primary lesion has been resected. When these policies are adopted, the incidence of cervical lymph node failures is extremely low in patients whose primary sites remain controlled, and morbidity from the cervical radiation fields is negligible.     

The impact of diaphragm management on prolonged ventilator support after thoracoabdominal aortic repair

PURPOSE: The relationship of the division of the diaphragm during thoracoabdominal aortic repair to prolonged ventilator support has not been studied. The purpose of this study was (1) to determine whether preservation of diaphragm integrity has a significant effect on postoperative ventilator duration and (2) to elucidate other pulmonary risk factors related to thoracoabdominal aortic surgery and to study the relationship of these factors to the intact diaphragm technique. METHODS:Between February 1991 and January 1997, we repaired 397 descending and thoracoabdominal aortic aneurysms. Descending thoracic aneurysms were not included in the study because their repair does not include the diaphragm. A total of 256 patients participated in this study. The diaphragm was divided in 150 patients and left intact in 106 patients. Examined as potential risk factors were patient demographics, history and physical findings, aneurysm extent, urgency of the procedure, acute dissection, cross-clamp time, homologous and autologous blood product consumption, and adjunctive operative techniques. FEV1 also was considered in the 197 patients for whom preoperative spirometry was available. Prolonged mechanical ventilation was defined as ventilator support for >72 hours. Data were analyzed by univariate contingency table and multiple logistic regression methods. RESULTS: Increasing age (odds ratio [OR], 1.02/y; P <.02), current smoking (OR, 2.6; P <.0008), total cross-clamp time (OR, 1.0/min; P <.008), units packed red blood cells transfused (OR, 1.06/unit; P <.008), and division of the diaphragm (OR, 2.03; P <.02) were significant, independent predictors of prolonged ventilation. Sixty-seven percent of patients (71 of 106) whose diaphragms were preserved were extubated in <72 hours compared with 52% of patients (78 of 150) who underwent diaphragm division (OR, 0.53; P <.02). CONCLUSION: Independently of well known pulmonary risk factors, an intact diaphragm during thoracoabdominal aortic repair results in a higher probability of early ventilator weaning.     

Lack of infection in HIV-exposed individuals is associated with a strong CD8(+) cell noncytotoxic anti-HIV response

Individuals repeatedly exposed to HIV, but who remain uninfected, form a population enriched for persons likely to have either natural or acquired resistance to the virus. We have studied four such exposed uninfected cohorts, representing 60 individuals, for evidence of protective immunity. This population included participants exposed to HIV through anal or vaginal receptive intercourse on multiple occasions over many years. We observed CD8(+)-cell noncytotoxic inhibition of HIV replication in acutely infected CD4(+) cells in the vast majority of individuals most recently exposed to the virus (within 1 year). The levels of this CD8(+)-cell response were sufficient to inhibit the in vitro infection of the exposed subjects' peripheral blood mononuclear cells. We found no evidence of a significant role for CCR5 Delta32 mutation in this population, nor did CD4(+) cell susceptibility to infection or HIV-specific cytotoxic T-lymphocytes correlate with resistance to infection in the individuals tested. Therefore, the observed strong noncytotoxic CD8(+)-cell anti-HIV responses may be an antiviral immune activity contributing to the apparent protection from infection in these exposed uninfected individuals.     

Stimulation of large-conductance Ca2+-activated K+ channels by Evans blue in cultured endothelial cells of human umbilical veins

The effect of Evans blue (EB) on large-conductance Ca2+-activated K+ (BKCa) channels was investigated in cultured endothelial cells of human umbilical veins. In whole-cell configuration, EB (50 microM) reversibly increased the amplitude of K+ outward currents (IK). When the patch pipettes were filled with 10 mM EGTA, its stimulatory effect on IK was unaltered. Further application of EB in the presence of suramin, a blocker of P2-purinergic receptor, or AOPCP, an inhibitor of 5'-nucleotidase, still increased IK. However, charybdotoxin (100 nM) suppressed EB-induced increase in IK. In inside-out configuration, bath application of EB (50 microM) did not change single channel conductance but significantly increased the activity of BKCa channels. The EB-induced increase in the activity of BKCa channels was independent on internal Ca2+. EB (50 microM) shifted the activation curve of BKCa channels to less positive membrane potentials by approximately 20 mV. The change in the kinetic behavior of BKCa channels caused by EB in these cells is due to an increase in mean open time and a decrease in mean closed time. These results indicate that EB can stimulate the activity of BKCa channel in endothelial cells. This effect is unrelated to its blockade of P2-purinergic receptors or inhibition of 5'-nucleotidase. The direct stimulation of these ionic channels by EB may contribute to its effect on capillary permeability.