A five-gene molecular phylogeny reveals Parapanteles Ashmead (Hymenoptera: Braconidae) to be polyphyletic as currently composed.

Parapanteles Ashmead (Braconidae: Microgastrinae) is a medium-sized genus of microgastrine wasps that was erected over a century ago and lacks a unique synapomorphic character, and its monophyly has not been tested by any means. Parapanteles usually are parasitoids of large, unconcealed caterpillars (macrolepidoptera) and have been reared from an unusually large diversity of hosts for a relatively small microgastrine genus. We used Cytochrome Oxidase I sequences ("DNA barcodes") available for Parapanteles and other microgastrines to sample the generic diversity of described and undescribed species currently placed in Parapanteles, and then sequenced four additional genes for this subsample (wingless, elongation factor 1-alpha, ribosomal subunit 28s, and NADH dehydrogenase subunit 1). We constructed individual gene trees and concatenated Bayesian and maximum-likelihood phylogenies for this 5-gene subsample. In these phylogenies, most Parapanteles species formed a monophyletic clade within another genus, Dolichogenidea, while the remaining Parapanteles species were recovered polyphyletically within several other genera. The latter likely represent misidentified members of other morphologically similar genera. Species in the monophyletic clade containing most Parapanteles parasitized caterpillars from only five families - Erebidae (Arctiinae), Geometridae, Saturniidae, Notodontidae, and Crambidae. We do not make any formal taxonomic decisions here because we were not able to include representatives of type species for Parapanteles or other relevant genera, and because we feel such decisions should be reserved until a comprehensive morphological analysis of the boundaries of these genera is accomplished.

In vitro adsorption of sodium pentobarbital by SuperChar, USP and Darco G-60 activated charcoals.

This study was designed to examine the in vitro adsorption of sodium pentobarbital by three activated charcoals. Solutions of sodium pentobarbital (20 mM) were prepared in distilled water and in 70% sorbitol (w/v). Radiolabeled (14C) sodium pentobarbital was added to each solution to serve as a concentration marker. Two ml of each drug solution was added to test tubes containing 40 mg of either Darco G-60, USP, or SuperChar activated charcoal. The drug-charcoal mixtures were incubated at 37 degrees C for O, 2.5, 5, 7.5 or 10 min. Equilibrium, indicated by a constant percentage of drug bound for two consecutive time periods, was established immediately for the aqueous mixtures and for Darco G-60 in sorbitol. The time to equilibrium was prolonged for USP (2.5 min) and SuperChar (5 min) in the presence of sorbitol. In the second series of experiments, solutions of sodium pentobarbital (1.25 to 160 mM) were prepared in either distilled water or sorbitol. Amount of drug bound by 10 to 320 mg of activated charcoal within a 10 min incubation period was determined. Scatchard analysis determined maximum binding capacity (Bmax) and dissociation constants (Kd) for each activated charcoal. In water, Bmax (mumoles/gm) was greatest for SuperChar (1141), followed by USP (580) and Darco G-60 (381), while the Kd's did not differ. Sorbitol did not change the Bmax or Kd of USP or Darco G-60, but the additive significantly decreased the Bmax (717) and increased the Kd for SuperChar (3.3 to 10.1 mM). The results suggest that relative binding capacity of activated charcoal is directly proportional to surface area, and that sorbitol significantly reduces sodium pentobarbital binding to SuperChar.

Effects of activated charcoal and sorbitol on sodium pentobarbital absorption in the rat.

Three activated charcoals were tested for their ability to reduce the oral absorption of sodium pentobarbital (SP) in rats. Fasted adult, male rats were given 40 mg/kg of C-14 labelled SP by gavage (2 ml). Five minutes after drug administration, the animals were given 40 mg of either Darco (G-60), United States Pharmacopeia (USP) or SuperChar (SC) activated charcoals. The charcoals were administered as a slurry in either 1 ml of water, or 1 ml of 70 percent (w/v) sorbitol solution. Water (control) and sorbitol given alone were tested separately. Various pharmacokinetic parameters were calculated from the plasma concentration of SP determined at various time intervals after drug administration. When given in water, only SC significantly (p less than .01) reduced the peak plasma concentration and oral bioavailability of SP. Sorbitol given alone produced diarrhea but did not affect drug absorption. However, sorbitol selectively enhanced the effectiveness of G-60 and USP charcoals and, as a result, all charcoals significantly reduced SP absorption when given along with the cathartic. The results suggest that when given in water, charcoal antidotal effectiveness is proportional to absorptive surface area, and that sorbitol may enhance the antidotal effectiveness of some charcoals but not others.

Spontaneous clearance of Chlamydia trachomatis infection in untreated patients.

BACKGROUND AND OBJECTIVES: To assess the spontaneous clearance of untreated Chlamydia trachomatis infections and factors correlated with the process. STUDY DESIGN: Spontaneous clearance was assessed through review of laboratory database, chart review, and laboratory testing using direct immunofluorescence (DFA) and polymerase chain reaction (PCR) tests on C. trachomatis culture transport media from patients with negative chlamydial cultures. Specimens (C. trachomatis culture transport media) were obtained from patients attending a Birmingham, Alabama sexually transmitted diseases clinic. The study group consisted of patients with positive cultures for C. trachomatis who had repeat specimens obtained for culture within 45 days of initial observation and who had not received recommended therapy for chlamydial infection in the interval between the two tests. RESULTS: Of 74 evaluable patients, 24 (32%) had negative follow-up cultures. Culture transport media for these 24 culture-negative patients were tested with DFA or PCR assays for chlamydial infection, and 3 (13%) were positive. Culture positivity rates declined significantly with increasing age and duration of follow-up. Interval treatment with benzathine penicillin resulted in apparent resolution of infection in 9 of 10 patients. Neither a history of a C. trachomatis-associated syndrome nor treatment with cefixime, metronidazole, or antifungal agents was associated with clearance of infection. CONCLUSIONS: These results are consistent with host response-mediated resolution of infection in a minority of patients and have implications regarding public health efforts to control chlamydial infection.