In healthy men, levels of endothelial progenitor cells may be a surrogate biologic marker for vascular function and cumulative cardiovascular risk. These findings suggest that endothelial injury in the absence of sufficient circulating progenitor cells may affect the progression of cardiovascular disease.

Nitrite anions comprise the largest vascular storage pool of nitric oxide (NO), provided that physiological mechanisms exist to reduce nitrite to NO. We evaluated the vasodilator properties and mechanisms for bioactivation of nitrite in the human forearm. Nitrite infusions of 36 and 0.36 micromol/min into the forearm brachial artery resulted in supra- and near-physiologic intravascular nitrite concentrations, respectively, and increased forearm blood flow before and during exercise, with or without NO synthase inhibition. Nitrite infusions were associated with rapid formation of erythrocyte iron-nitrosylated hemoglobin and, to a lesser extent, S-nitroso-hemoglobin. NO-modified hemoglobin formation was inversely proportional to oxyhemoglobin saturation. Vasodilation of rat aortic rings and formation of both NO gas and NO-modified hemoglobin resulted from the nitrite reductase activity of deoxyhemoglobin and deoxygenated erythrocytes. This finding links tissue hypoxia, hemoglobin allostery and nitrite bioactivation. These results suggest that nitrite represents a major bioavailable pool of NO, and describe a new physiological function for hemoglobin as a nitrite reductase, potentially contributing to hypoxic vasodilation.

This study was conducted to investigate the risk factors associated with peripartum hysterectomy in women who had either vaginal or cesarean delivery. The study subjects were women (n ϭ 101) who had a peripartum hysterectomy at the authors' institution from January 1986 to April 2001. Seventy-two of the 101 patients had delivered at Yonsei University Medical Center and 29 were referred from other hospitals. Of the total 31,044 deliveries at Yonsei during this time period, 11,924 were performed by cesarean section. Fifty-four of these women (0.45%) and 28 of the 19,080 who had a vaginal delivery (0.09%) underwent peripartum hysterectomy. Five of the 29 referred patients had a cesarean section and 24 had a vaginal delivery. The average time from delivery to hysterectomy was significantly longer in the vaginal group than in the cesarean section group (169 min vs. 49 min; P Ͻ.05). Also, women who had a vaginal delivery required significantly more blood (1908 ml) than those who had a cesarean section (1536 ml)(P Ͻ.05), although the average length of hospital stay was similar for both groups. Uterine atony was the most common indication for peripartum hysterectomy (42 of 101; 41.6%). Placenta previa accreta, placenta accreta, and placenta previa was the diagnosis in 23.8%, 16.7% and 11.9% of patients, respectively. Among the 29 women who had a previous cesarean section, the indications were uterine atony (n ϭ 10; 34.5%), placenta previa accreta (n ϭ 13; 44.8%), placenta previa (n ϭ 4; 13.8%), and placenta accreta (n ϭ 2; 6.9%). Blood loss was more highly associated with placenta previa accreta than with placenta previa or accreta alone (1734 ml vs. 16,58 ml and 1084 ml, respectively; P Ͻ.05). The only complications recorded were bladder injury in one woman with placenta previa, one disseminated intravascular coagulopathy in the placenta accreta group, and one case of sepsis among patients with placenta previa accreta. Of the 59 peripartum hysterectomies associated with cesarean section, 26 were in women undergoing elective cesarean section (44.1%) and 33 were after emergency cesarean section (55.9%). Blood loss was similar in both groups. The women who had emergency surgery experienced a higher complication rate than those undergoing elective cesarean section. Two patients sustained bladder injury, one had ureteral injury, one had bowel injury, one developed acute hepatitis, and one had disseminated intravascular coagulopathy. In the elective surgery group, there was a bladder laceration in one patient and another patient had disseminated intravascular coagulopathy. GYNECOLOGYVolume 58, Number 7 OBSTETRICAL AND GYNECOLOGICAL SURVEY ABSTRACT This paper presents the results of an investigation of the force required to insert a laparoscopic trocar into the abdominal cavity. Both disposable and reusable laparoscopic trocar systems were studied. Study subjects were 20 consecutive women who were scheduled to undergo routine diagnostic and laparoscopic surgery and were randomly selected for either the disposable trocar device...