OBJECTIVE:To determine if streptococcicidal levels of penicillin G benzathine can be detected in maternal serum 4 weeks after treatment with 4.8 million units. METHODS:Thirty-seven pregnant women with positive group B streptococcus vaginal or urine cultures were each given 4.8 million units of penicillin G benzathine. Maternal blood samples were collected after injection and at delivery. Serum penicillin levels were measured by high-pressure liquid chromatography. Follow-up cultures were done when possible. RESULTS:None of the patients had serum penicillin levels below 0.20 microgram/mL 30 days after treatment. Cord blood levels were approximately 50% lower than maternal levels. In all but three subjects, cord blood levels exceeded 0.06 microgram/mL, the minimal inhibitory concentration for group B streptococcus. The three exceptions were patients who delivered more than 100 days after treatment. Group B streptococcus cultures were negative at the time of delivery in 72% of cases. None of the patients with positive cultures were moderately or heavily colonized. CONCLUSION:In pregnant women, penicillin G benzathine levels are high enough to inhibit the growth of group B streptococcus for more than 4 weeks after injection with 4.8 million units. Further studies are needed to evaluate whether this regimen can prevent neonatal colonization and invasive group B streptococcus disease.

Previous studies have established efficacy of transseptal defibrillation. The purpose of the present study was to evaluate the role of transvenous electrode surface area for defibrillation. Sixteen dogs were randomized to 8 French and 5 French EnGuard electrodes; 8 dogs in each group. The length of the defibrillation coils was identical for both, but the surface area was different due to differences in the electrode diameters. Defibrillation threshold (DFT) testing was performed using a biphasic shock waveform, 6 msec+/2msec-. Logistic regression analysis was used to determine if the probability of defibrillation adjusted for voltage, current, and energy was different for 8 French electrodes. Logistic regression analysis found significant differences between 8 French and 5 French electrodes, with less voltage (P < 0.005), current (P < 0.03), and energy (P < 0.001) required at any level of probability to defibrillate for 8 French electrodes. These results support the conclusion that the surface area for endocardial electrodes is a significant factor for defibrillation. Therefore, when designing endocardial electrodes a desirable objective of reducing the electrode size should be weighed against the need to minimize DFTs.

The conventional electrode configuration of current internal defibrillation systems most commonly use superior vena caval (SVC) or combined SVC and subcutaneous (SC) electrodes as anode, and right ventricular apex (HVA) electrode as cathode. We have demonstrated earlier that the septal mass is important for defibrillation. The purpose of the present study was to compare a transseptal to a conventional electrode arrangement in the canine model. Three endocardial electrodes, 5 French EnGuard™ were positioned in RVA, SVC, and the right ventricular outflow (RVO) in eight dogs. A 5 French SC electrode was positioned in the fifth left intercostal space. RVA‐RVO‐/SC+ (configuration 2) was compared to SVC‐SC+/RVA‐(configuration 1). Defibrillation threshold testing was performed using asymmetrical biphasic shock, 6 msec+/2 msec‐. Probit fit was used to compare the results at 40%, 50%, 60%, and 90% probabilities, and the logistic regression analysis to estimate the impact of variables. Electrode configuration had the strongest predictive value. Configuration 2 was superior to configuration 1 (P = 0.0016). At any voltage settings the probability of success for configuration 2 was greater, and current less (P < 0.00005). The energy requirements were reduced by approximately 33% for configuration 2. There were no significant differences in impedance between the two configurations. We conclude that transseptal defibrillation is more effective because of the improved lead geometry and voltage gradient.

This study further defines the clinical utility of squamous cell carcinoma antigen (SCC-Ag) in initial squamous carcinoma of the cervix, response to treatment, and in the detection of recurrence. Serum specimens were drawn and analyzed from patients with squamous cell carcinoma. Charts were reviewed on 272 patients with 1053 samples evaluated. Treatment of patients prior to the availability of the assay and patients lost to follow-up resulted in lower total numbers of initial and recurrent values. Data were analyzed to detect trends during and after treatment. All values at or above the lowest detectable level of antigen were included; that is, 1.5 ng/ml and above. A SCC-Ag value > or = 2.0 ng/ml drawn at any time during the disease process has a 96.3% positive predictive value, while a value < 2.0 ng/ml is 97.2% specific for absence of disease. Fifty-three percent of 103 patients had elevated SCC-Ag levels prior to treatment, with the proportion increasing accordingly with advancing stage at diagnosis. In 70 patients with recurrence, 81% had elevated values. Squamous cell carcinoma antigen predicted recurrence an average of 6.9 months prior to detection of clinically evident disease. Patients with initially negative SCC-Ag levels may demonstrate elevated values with tumor recurrence. This marker accurately reflects the response to treatment in patients who have elevated levels prior to treatment. Squamous cell carcinoma antigen is a useful tumor marker in the management of patients with squamous cell carcinoma of the uterine cervix.