Teichoic acid antibody and circulating immune complexes in the management of staphylococcus aureus bacteremia

Optimal antibiotic therapy for patients with Staphylococcus aureus bacteremia remains controversial. The results of two serologic tests, teichoic acid antibody and circulating immune complexes, have shown promise in detecting patients who have serious bacteremia (sustained bacteremia with endocarditis or metastatic abscess) and require longer, more intensive treatment. These tests were performed on serial samples from 38 patients with staphylococcal bacteremia prospectively categorized by severity of infection and by risk factors associated with serious disease (sustained bacteremia, valvular heart disease, absence of focus of infection, metastatic abscess). A surprisingly large group of these patients (20, or 53 percent) could not be prospectively defined as having “serious” or “benign” bacteremia. Neither test differentiated patients with serious bacteremia from those with benign bacteremia. Although it is possible that additional significant associations with risk factors might have been obtained with the teichoic acid antibody test had more patients been included, positive tests were found more frequently only in patients in whom metastatic abscesses developed. The teichoic acid antibody test was found to be a sensitive, but not specific, indicator of serious staphylococcal disease and was of value in excluding serious infection only when a negative result was supported by clinical evidence for benign disease. Other than this use, neither assay was helpful in determining optimal therapy of staphylococcal bacteremia.     

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.     

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.     

鼠药毒饵中氟乙酸钠提取方法的比较与氟乙酰胺转化的观察

比较了不同溶剂系统对毒饵中氟乙酸钠提取效果的影响。在所试验的四种溶剂系统中，以水的提取效果最好，毒饵是否粉碎对提取效果没有影响。另外，还观察到，在自然放置过程中毒饵中的氟乙酰胺转化为氟乙酸钠。     

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.     

Use of a sagittal oscillating saw for repeat sternotomy: a safer and simpler technique

A method of repeat sternotomy using a microsagittal oscillating saw is described. We have found this method to be safer and simpler than previously described techniques. We have used this technique in more than 50 repeat sternotomies without a single complication related to the mediastinal reentry procedure.