cDNA clone encoding a high molecular weight antigen of Babesia bovis

An expression library was constructed by inserting cDNA copied from mRNA of the blood stages of Babesia bovis isolate KA into bacteriophage lambda gt11-amp3. An antigen-positive cDNA clone detected by screening the library with antibodies from cattle vaccinated with the KA isolate was shown to encode part of a high-molecular weight polypeptide antigen of B. bovis. This molecule was a dominant immunogen and was found by immunofluorescence to be within the parasite in infected erythrocytes.     

Vaccination of human volunteers with heat-killed M. leprae: local responses in relation to the interpretation of the lepromin reaction

The early (Fernandez) and late (Mitsuda) lepromin reactions were closely examined in a group of healthy, BCG-vaccinated individuals who were given four doses of a heat-killed, armadillo-derived vaccine, i.e., 1.5 X 10(7), 5 X 10(7), 1.5 X 10(8), and 5 X 10(8) bacilli. There was a clear dose-response relationship for both the early and late reactions with no leveling of the responses within the range of doses examined. While the early response was negative in most of the volunteers, the late response was positive in all of the volunteers. No association was found between the early lepromin test and the pre-vaccination skin test to PPD. There was also no association between the early lepromin test and the pre-vaccination skin test response to a soluble Mycobacterium leprae antigenic preparation (MLSA) in general, but there was a good correlation between these two parameters at the highest vaccine dose. The late lepromin response showed no association with either the prevaccination or post-vaccination skin test response to PPD. However, there was a significant correlation between the late lepromin response and the post-vaccination skin test response to MLSA. In general, no association could be found between the in vivo skin tests and the in vitro lymphocyte transformation test (LTT). Thus, the lepromin test is essentially a vaccination which elicits a specific response to M. leprae antigens provided that the dose of armadillo lepromin given is higher than 5 X 10(7). Therefore, it is unsuitable as a diagnostic test for leprosy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Computer-directed stereotactic biopsy of intrinsic brain stem lesions

Despite advances in the neuro-imaging of the brain stem, an accurate diagnosis of intrinsic lesions in this region requires tissue sampling and histological verification. We have performed a series of computer-directed stereotactic procedures in 12 patients with intrinsic brain stem lesions. A positive diagnosis was obtained in 11 cases and therapeutic intervention was possible in four. There was no operative mortality. Because of the importance of an accurate diagnosis in order to avoid inappropriate therapy, together with the relative safety of the technique, computer-directed stereotactic biopsy should be considered in all patients harbouring an intrinsic brain stem mass.     

Piperacillin-Tazobactam Pharmacokinetics in Patients With Intraabdominal Infections

Study Objective . To determine the appropriate compartmental and noncompartmental pharmacokinetic parameters for intravenous piperacillin and tazobactam. Design . Sequential selection of patients entered into a randomized, open-label clinical efficacy trial. Setting . Los Angeles County-University of Southern California Medical Center. Participants . Sequential sample of 18 patients admitted for intraabdominal infections and consented into a comparative antibiotic trial. Interventions . Patients received piperacillin 4 g plus tazobactam 500 mg by intravenous intermittent infusion every 8 hours. Measurements and Main Results . The estimated noncompartmental pharmacokinetic parameters (mean ± SD) for piperacillin and tazobactam, respectively, were as follows: maximum concentration in plasma 218.7 ± 48.9 μg/ml and 27.8 ± 9.1 μg/ml; half-life 1.07 ± 0.22 hours and 1.00 ± 0.27 hours; elimination rate constant 0.67 ± 0.13 hr⁻¹ and 0.73 ± 0.18 hr⁻¹; area under the concentration-time curve from zero hour to infinity 288.5 ± 71.25 mg·hr/L and 36.3 ± 9.55 mg·hr/L; total plasma clearance 14.75 ± 3.93 L/hour and 14.78 ± 4.39 L/hour; renal clearance 5.69 ± 1.94 L/hour and 7.85 ± 3.37 L/hour; volume of distribution at steady state 21.00 ± 4.18 L and 22.47 ± 8.27 L; and mean residence time 1.72 ± 0.29 hours and 1.79 ± 0.35 hours. Conclusion . Our findings were similar to those in other surgical patient models. The two-compartmental model best described piperacillin and tazobactam disposition in our patients. Bayesian analyses of the two-compartment models of piperacillin and tazobactam were able to predict trough, peak, and 2-hour postadministration levels without bias.     

Comparative study of two computerized semen motility analyzers

Semen analysis is one of the primary tests carried out to investigate the infertile male. Subjective evaluation of semen is often prone to observer bias and error. To eliminate this, a number of computerized semen analyzers have recently been introduced into the market and we have evaluated two of the more popular models, the Cell Soft Semen Analyzer and the Hamilton Thorn Motility Analyzer (HTM 2000). The Cell Soft identifies sperm on the basis of user defined values for cell size and luminosity whereas the Hamilton Thorn identifies sperm by motility, and then applies the computer-calculated average size and luminosity of all moving objects to non moving sperm cells. Semen samples from 25 normal donors and 25 subfertile patients were analyzed using these two models of computerized semen analyzers, and also by an experienced technician using both the Makler chamber and the hemocytometer. The results obtained from the two automated analyzers were compared with those obtained by subjective evaluation. Variation in sperm count and motility were analyzed according to the sperm density. Four groups, less than 30 million/ml with debris, less than 30 million/ml, 30-50 million/ml, and greater than 50 million/ml were studied. The majority of patients fit into the first two groups. We observed that the HTM 2000 is superior to the Cell Soft in evaluating sperm count within the patient population group. For our donor population with an average sperm count of greater than 85 million/ml both systems provide extremely accurate counts.(ABSTRACT TRUNCATED AT 250 WORDS)