Clostridial necrotizing enterocolitis

In a bacteriologic investigation of infants with necrotizing enterocolitis (NEC), 16 of 50 infants had clostridia in cultures of blood or of peritoneal fluid obtained by paracentesis. Twenty-eight of the 50 infants had enteric bacteria other than clostridia, and six infants had sterile cultures. Of the 16 infants with clostridia, nine had C. perfringens and seven had other species of clostridia. Compared to infants with nonclostridial NEC, those with clostridial NEC were larger and more mature, had more extensive pneumatosis intestinalis and gangrene and more rapid progression of NEC. The nine infants with C. perfringens had a fulminant form of NEC, analogous to gas-gangrene of the intestine. Mortality in this group was 78% (7/9). The seven infants with clostridial species other than C. perfringens had a mortality comparable to that of infants with nonclostridial NEC (32%). Improved survival from NEC associated with C. perfringens may be possible only by prevention, rather than earlier diagnosis and improved heroic treatment.     

Relationship between zinc intake, physical activity, and blood levels of high-density lipoprotein cholesterol in a healthy elderly population

We investigated the relationship between level of exercise, ingestion of zinc supplements, and serum high-density lipoprotein (HDL) cholesterol levels in 270 healthy men and women over age 60. After controlling for sex, alcohol intake, and body mass, there was a significant positive correlation between level of exercise and serum HDL cholesterol in the 180 subjects not taking supplemental zinc (r = 0.26, P = .005) but not for those subjects taking supplemental zinc (r = -0.18, P = .14). Multiple regression analysis showed a significant interaction of zinc intake and activity level on HDL cholesterol (P = .04). In 22 subjects who were ingesting greater than 15 mg of supplemental, elemental zinc daily, cessation of zinc supplements for 8 weeks was associated with a significant increase in HDL cholesterol levels (2.0 mg/dL; P = .04). The change in HDL after stopping zinc was positively correlated with the level of exercise of the subjects (r = .41, P = .05). Thus supplemental zinc ingestion appears to block the exercise-induced increase in serum HDL cholesterol in a healthy population.     

Prolonged ileus after severe pelvic fracture

The data derived from 105 severe pelvic fractures have provided guidelines for managing paralytic ileus associated with fracture. Fracture types I, II, IV, and double type III can be treated expectantly with a high degree of confidence that ileus will resolve within 2 days. Type III diametric fractures can be managed similarly for 5 days with a 70 percent (14 of 20 patients in this study) likelihood that ileus will resolve. However, should ileus in patients with diametric fractures continue longer than 5 days, parenteral nutrition should be started, since ileus will persist for an average of 2 weeks. A direct correlation between type of pelvic fracture, amount of retroperitoneal blood, loss and duration of ileus has been documented.     

Bovine carotid artery heterografts versus polytetrafluoroethylene grafts. A prospective, randomized study

A prospective, randomized comparison of BCAH and PTFE vascular access grafts resulted in no statistically significant difference when analyzed for survival rates of complications, types of complications, reasons for failure, and clot salvageability. The results in diabetic patients were similar to those in nondiabetic patients. The majority of retrospective studies and subjective experiences favor PTFE grafts over BCAHs. The explanation may be part that BCAH preceded PTFE grafts into clinical use, and inexperience in the operating room and in the dialysis unit had an effect on BCAH results. A review of impressions of the graft materials indicated a decided preference for PTFE grafts.     

Comparison of noninvasive pulsed Doppler and Fick measurements of stroke volume in cardiac patients

We compared simultaneous measurements of stroke volume by direct Fick (SV_F) and noninvasive pulsed Doppler (SV_D) techniques in 15 resting, supine cardiac patients. Doppler measurements of ascending aorta blood velocity were obtained from the suprasternal notch with a single crystal transducer. The systolic velocity integral of the spatial-average velocity waveform was multiplied by cross-sectional area from the systolic aortic diameter, obtained independently by M-mode echocardiography, to determine absolute values for SV_D. The resulting linear regression equation was SV_D = ?1.14 + 0.95SV_F, r = +0.91, p < 0.0001. The mean SV_D and SV_F values were 68 and 73 cm³, respectively. These results in consecutive patients serve to validate empirically the pulsed Doppler method at rest. It is a convenient, safe, and painless procedure which appears appropriate for clinical diagnostic screening where serial measurements would be useful. However, this noninvasive technique does require technical experience and an understanding of anatomy and flow waveforms by the operator to obtain valid measurements.     

Habituation of the prolactin response in rats to psychological stress

It is well known that stress is a stimulant for prolactin release. However, relatively few studies have investigated the role of psychological factors in prolactin secretion, and investigators have typically used one-time exposure and a single collection period in their studies. In our studies, attempts were made to carefully characterize the prolactin response to different psychological stressors by serially sampling blood from an indwelling cannula and to determine if repeated exposure to the stressor leads to habituation of the prolactin response. Exposure of the male rats to different novel situations such as being placed in a new cage, being placed on a platform in water, or being handled resulted in increased prolactin levels. As the rats habituated behaviorally to repeated exposure to similar situations, the prolactin response also attenuated. These findings show that psychological factors do play a role in influencing prolactin secretion and are consistent with the idea that as the psychological stress imposed by a stimulus becomes habituated, the prolactin response to that stimulus also becomes habituated.     

Controlled Trial of Routine Administration of Platelet Concentrates in Cardiopulmonary Bypass Surgery

Prophylactic administration of platelet concentrates to patients undergoing their first cardiopulmonary bypass operation (coronary artery bypass grafting or uncomplicated valve replacement) was evaluated in a controlled randomized study of 28 patients. Four units of platelet concentrates administered at the end of bypass prevented prolongation of the bleeding time seen in patients not receiving platelets. However, chest tube blood loss, transfusion requirements, and clinical outcome were not improved. Moreover, thrombocytopenia and prolongation of bleeding time did not correlate with blood loss or transfusion needs. Mild thrombocytopenia (to 58,000 platelets per microliter) and transient platelet dysfunction after bypass do not require administration of platelet concentrates, and prophylactic use of this blood component in the surgical setting of bypass is not indicated.     

Periovulatory enhancement of spontaneous prolactin secretion in normal women

The role of endogenous estrogen in the regulation of prolactin secretion in man is controversial. To study this question further, spontaneous prolactin patterns were determined over 5 hr in 10 normal women during the early follicular and again during the periovulatory phases of the menstrual cycle. Steroid determinations revealed significant elevations in mean ±1 SE E₁ (113 ± 20 versus 55 ± 5 pg/ml), E₂ (144 ± 47 versus 48 ± 9 pg/ml), and 17-OHP (1,301 ± 266 versus 639 ± 46 pg/ml) during the periovulatory compared to the early follicular phase period. Each subject demonstrated increased mean plasma prolactin concentration during the higher estrogen state. Mean prolactin concentration (calculated from the individual mean values of samples obtained at 15 min intervals for 5 hr) during the midcycle study period was 10.7 ± 1.0 ng/ml compared to the early follicular phase period of 8.1 ± 1.0 ng/ml (p < 0.0005). The mean percent increment in plasma prolactin during the periovulatory period was 39% with a range of 9 to 117%. There was no correlation between mean prolactin and serum E₁, E₂, P, or 17-OHP levels during either study period. However, the incremental change in prolactin showed a positive correlation with the incremental increase in E₂ (correlation coefficient, r = 0.66, p < 0.05). In contrast, no significant correlation was present between mean incremental change in prolactin and E₁, P, or 17-OHP. These data suggest that enhanced cyclic estrogen secretion during the periovulatory phase of the menstrual cycle is associated with significantly increased serum prolactin concentrations.     

Ventricular arrhythmias in aortic valve disease: Analysis of 102 patients

Frequency and grade of ventricular arrhythmias in patients with isolated aortic stenosis (AS) or regurgitation (AR) were determined by 24-hour ambulatory electrocardiographic monitoring. The occurrence of ventricular arrhythmias in patients with aortic valve disease was compared with that in matched control subjects without aortic valve disease. Complex arrhythmias were significantly more prevalent in patients with valve disease than in control subjects (40 of 102 vs 19 of 102); the significant difference occurred in patients without concomitant coronary artery disease (CAD). In patients with valve disease without CAD, complex arrhythmias were significantly more common than in normal control subjects (22 of 65 vs 4 of 64); in the presence of CAD, complex arrhythmias were as prevalent in those with aortic valve disease as in those without it (18 of 37 vs 15 of 37, respectively). Among patients with AS or AR, arrhythmia occurrence and grade of ventricular ectopic activity were not related to the degree of AS or AR, ventricular hemodynamics or the presence or absence of concomitant CAD.