Neonate with coxsackie B1 infection, cardiomyopathy and arrhythmias

A neonate with Coxsackie B1 infection who experienced significant congestive heart failure, cardiomyopathy and arrhythmia is reported. Viral myocarditis, an important cause of acquired heart disease in neonates, should be considered in the differential diagnosis of neonatal congestive heart failure and cardiomyopathy. A review of the literature is presented.     

A short cervix in women with preterm labor and intact membranes: a risk factor for microbial invasion of the amniotic cavity

OBJECTIVE: The purpose of this study was to determine whether there was a relationship between sonographic cervical length and the presence of culture-proven microbial invasion of the amniotic cavity in women with preterm labor and intact membranes. STUDY DESIGN: Ultrasonography and amniocentesis were performed in 401 patients admitted with preterm labor (22-35 weeks) and cervical dilatation of < or = 3 cm, as assessed by digital examination. Cervical length was determined by transvaginal ultrasound at admission. Outcome variables were the presence of microbial invasion of the amniotic cavity (defined as a positive amniotic fluid culture) and the occurrence of preterm delivery before 35 weeks. Contingency tables, chi2 test, receiver-operator characteristic (ROC) curves, and logistic regression were used for statistical analysis. RESULTS: The prevalence of microbial invasion of the amniotic cavity was 7% (28/401). Spontaneous preterm delivery (< or = 35 weeks) occurred in 21.4% (82/384) of patients. ROC curve analysis showed a significant relationship between the frequency of microbial invasion of the amniotic cavity and the length of the uterine cervix (area under the curve: 0.77; P < .005). Patients with a cervical length < 15 mm had a higher rate of a positive amniotic fluid culture than patients with a cervical length > or = 15 mm (26.3% [15/57] vs. 3.8% [13/344], respectively; P < .05). Moreover, patients with a short cervix (defined as < 15 mm) were more likely to deliver spontaneously before 35 weeks, 32 weeks, within 7 days, and within 48 hours of admission ( P < .05 for all comparisons). Forty percent of patients (161/401) had a cervical length > or = 30 mm. These patients had a very low risk of microbial invasion of the amniotic cavity (1.9% [3/161]), spontaneous delivery < or = 35 weeks (4.5% [7/154]), < or = 32 weeks (2.6% [2/76]), within 7 days (1.9% [3/154]), and within 48 hours (0% [0/154]) of admission. CONCLUSION: Endovaginal ultrasonographic examination of the uterine cervix in women with preterm labor identifies patients at increased risk for intrauterine infection.     

Long-term effects of acute and of chronic hypoxia on behavior and on hippocampal histology in the developing brain

Ten-day-old rat pups (P10) subjected to acute hypoxia (down to 4% O2) had as adults increased aggression (handling test), memory impairment (water maze test), and decreased CA1 cell counts. Pups subjected to chronic hypoxia (10% O2 from P0 to P21) had increased aggression, hyperactivity (open-field test), and decreased CA1 cell counts. Chronic hypoxia with superimposed acute hypoxia resulted in consequences that were not different from those of chronic hypoxia.     

Actinobacillus actinomycetemcomitans suppresses rat natural killer cell activity in vivo

OBJECTIVE: To examine the immune suppressive effect of Actinobacillus actinomycetemcomitans (Aa) on rat natural killer (NK) cell activity in vivo. MATERIAL AND METHODS: Sprague Dawley rats were given Aa in 2 different manners: (i) by mixing Aa with food at a dose of 10(8) cells/rat/day for 3 months; or (ii) by a single i.m. injection of live Aa at doses of 10(6) and 10(7) cells/rat/day. NK cell activity was measured by means of a 51Cr-release assay using YAC-1 tumor cells as targets. RESULTS: Rats that had been infected by Aa mixed with food experienced significant suppression of their NK cell activity; this reached approximately =50% of control values at 2 and 3 months post-Aa infection. The suppression in NK cell activity was related to decreases in the extent of conjugate formation between effectors and YAC-1 target tumor cells (51.7%) and the extent of lysis of target cells (75.7%). The results also showed that addition of an admixture of Aa-treated NK cells to the control NK cells caused 75% and 53% decreases in activity at effector:target ratios of 25:1 and 50:1, respectively. In addition, a significant increase in the extent of T-suppressor cells (154.8% of control) was detected at 3 months post-Aa infection. In contrast, the single injection of live bacteria resulted in a remarkable, dose-dependent inhibition of NK cell activity (55% and 71% at doses of 10(6) and 10(7) cells/rat/day, respectively) as early as 2 days post-treatment. This also reflected significant suppression in the effector:target conjugate formation ratio (52% of control). The data also revealed a 150-188% increase in the number of splenic lymphocytes post-Aa injection. These effects were transient and normal levels were re-established by the fifth day CONCLUSION: Aa treatment causes suppression of NK cell activity and the mode of action may be due to induction of T-suppressor cells or dilution of NK cells with other lymphoid cell populations. The degree of suppression is affected by the way in which Aa is introduced to the host. These results may contribute to the understanding of how Aa evades host defense.     

The efficacy of supplemental magnesium in reducing atrial fibrillation after coronary artery bypass grafting

BACKGROUND: Atrial fibrillation after coronary artery bypass is reported from 17% to 53%. Hypomagnesemia after this surgery is considered a contributing factor. METHODS: Two hundred-two coronary bypass patients were randomized to magnesium (n = 105) or placebo (n = 97). The experimental group received 80-mg magnesium sulfate per kilogram ideal weight in 100 mL dextrose 5% water 30 minutes preoperatively. Postoperatively, patients received 8-mg magnesium sulfate per kilogram ideal weight intravenous per hour more than 48 hours. The control group received dextrose 5% water at these intervals. RESULTS: After the first bolus serum magnesium was experimental 4.75 mg/dL versus control 1.91 mg/dL, p less than 0.001, and remained different until postoperative day 4 (experimental 2.33 mg/dL vs control 2.26 mg/dL, p = 0.24). Atrial appendage and strap muscle were analyzed after the first bolus and after revascularization. There were no differences between groups in tissue magnesium or calcium. Urinary magnesium was elevated in the experimental (experimental 324.5 mg/24 hours, vs control 45.1 mg/24 hours, p = 0.01). Calcium excretion was higher (experimental 370 mg/24 hours vs control 186 mg/24 hours, p < 0.001) and was associated with lower serum calcium. Serum calcium was higher in the control through the fourth postoperative day. The incidence of atrial fibrillation was experimental 32 of 105 (30.5%) versus control 41 of 97 (42.3%) p = 0.08. Atrial fibrillation was different on the first postoperative day (experimental 3/105, 2.9% vs control 9/97, 9.3%), p = 0.05. CONCLUSIONS: Overall prophylactic magnesium supplementation does not significantly reduce atrial and ventricular arrhythmias. The only significant benefit of magnesium supplementation was on the first postoperative day.