Larval habitat characterization for Aedes triseriatus (Say), the mosquito vector of LaCrosse encephalitis in West Virginia.

OBJECTIVE: The principal aim of this investigation was to provide quantitative information on the frequency of occurrence for Aedes triseriatus (Say) larvae in West Virginia at 3 broad elevation categories, in different months of the year, and in specific types of larval habitats. METHODS: Larvae were collected in 54 West Virginia counties over a 6-year period, and their occurrence was recorded for defined habitat categories. RESULTS: Aedes triseriatus larvae were collected at 206 of the 587 sites examined and in 48 of the 54 West Virginia counties sampled. CONCLUSION: Aedes triseriatus larvae are distributed equally across all elevation categories from March through October and are predisposed to shaded habitats.

Marijuana and medicine: assessing the science base: a summary of the 1999 Institute of Medicine report.

In response to public pressure to allow the medical use of marijuana, the Office of National Drug Control Policy, Washington, DC, funded a study by the Institute of Medicine evaluating the scientific evidence for benefits and risks of using marijuana as a medicine. The report used scientific reviews, public hearings, and reports from other agencies, and was evaluated by knowledgeable advisors and reviewers. It called for heavier investment in research on the biology of cannabinoid systems, careful clinical studies of cannabinoids in clinical syndromes, analysis of cannabinoids' psychological effects on symptoms, and evaluations of the health consequences of heavy marijuana use; recommends against the use of smoked marijuana in medicine and for the development of a medical cannabinoid inhaler; and recommends that compassionate use of marijuana be considered under carefully reviewed protocols. Finally, the report evaluates the abuse potential, tolerance, withdrawal, and gateway risks of medical use of cannabinoid drugs.

Intrahepatic larval nematode infection in the northern spring peeper, Pseudacris crucifer crucifer (Anura: Hylidae), in West Virginia.

Larval stages of an unknown nematode were observed encapsulated in the livers of spring peepers, Pseudacris crucifer crucifer (Weid-Neuweid), collected from a marsh in western West Virginia (USA) during the spring breeding seasons of 1993 and 1994. Prevalence and mean intensity of infection were 37% (30 of 82 animals) and 2.03 parasites per infected host, respectively. Capsules with white or darkly pigmented walls were observed in infected livers; the former containing viable larvae, and the latter enveloping larvae in various stages of degeneration.

Parasitic arthropods of white-footed mice at McClintic Wildlife Station, West Virginia.

Seven species of parasitic arthropods (one sucking louse, one bot, 2 fleas, one tick, and 2 mites) were recovered from 81 white-footed mice, Peromyscus leucopus, live-trapped on the grounds of the McClintic Wildlife Station, Mason County, WV, from March through November 1990. The most commonly collected arthropods were the fleas Orchopeas leucopus (89 specimens) and Epitedia wenmanni (23), and the tick Dermacentor variabilis (38). Sex ratios for both flea species were female biased; 1.8:1.0 for O. leucopus and 1.6:1.0 for E. wenmanni.

Mosquitoes of West Virginia: an update.

Nineteen species of larval mosquitoes were collected from 209 sites in 47 of West Virginia's 55 counties over a 7-month period (April-October) in 1992. Aedes abserratus is recorded from the state for the first time.

Protein differences in tau mutant hamsters: candidate clock proteins.

In the tau mutant hamster, the period of the circadian rhythm is shortened from about 24 h to about 22 h in heterozygotes and to about 20 h in homozygotes. Understanding the biochemical basis of the period changes in the tau mutant may elucidate the regulation of the vertebrate pacemaker. Using two-dimensional gel electrophoresis, we have found two sets of proteins that differ between the different genotypes. P33tau (about 33 kDa; pI 6.5) was found in all gels from wild type and heterozygous animals, but was absent in gels from all except one of the homozygous mutant animals. P32tau (about 32 kDa; pI 4.8) was a chain of spots, which showed a striking difference in pattern between gels from wild type animals and from mutant animals. P33tau was greatly enriched in soluble cellular fractions, whereas P32tau was found only in insoluble fractions. These differences between P33tau and P32tau were apparent in gels from both SCN and cortical tissue, suggesting that both proteins are distributed throughout the brain. These proteins should be useful as new tools to explore the biochemistry of circadian pacemakers.

Combined effects on the circadian clock of agents with different phase response curves: phase-shifting effects of triazolam and light.

Although light provides the primary signal for the entrainment of circadian pacemakers, a number of endogenous substances and pharmacological agents are also capable of resetting circadian pacemakers. Very little is known about the combined effects of photic and nonphotic agents on clock functions. We conducted a "double-pulse" experiment, in which two discrete stimuli are presented at different times within a single circadian cycle, to determine the combined effects of a 1-hr light pulse and injections of a benzodiazepine, triazolam, on the circadian rhythm of activity in the golden hamster. Our results suggest that, first, when given together as done in these experiments, the effects of triazolam and light are partially but not completely additive. Triazolam-induced phase advances appeared to make the effects of subsequent 1-hr light pulses more negative; phase delays were increased, and phase advances were decreased. Second, it appears that triazolam and light may alter the circadian pacemaker in very different ways, beyond the obvious difference in the shape of their phase response curves. The phase-shifting mechanics of the circadian system of the golden hamster appear to involve a longer response time to triazolam than to light pulses. Alternative possibilities to account for this difference are discussed.

Ontogeny of the circadian system controlling release of sperm from the insect testis.

In the gypsy moth, the release of sperm bundles from the testis into the vas deferens is rhythmic and is controlled by a circadian pacemaker located in the reproductive system. However, in males kept since pupation in constant darkness (DD) and temperature, the release of sperm was arrhythmic. The release of sperm became rhythmic when males were transferred from a light-dark cycle (LD 16:8) to DD 6-7 days after pupation. To further investigate the development of the circadian system during the pupal stage, we exposed DD pupae to a single 8-hr pulse of light or 8-hr pulse of a 4 degrees C temperature increase on different days after pupation. The pattern of sperm release was determined 5-6 days after the pulse. Males that were exposed to light or temperature pulses 5 days after pupation subsequently showed nonrhythmic sperm release. However, about half of the pupae that received the pulse on day 6 and most of the pupae that received it on day 7 subsequently showed synchronized sperm release. These results suggested that the clock underlying rhythmic release of sperm becomes operational at approximately 6 days after pupation--that is, 2 days prior to initiation of rhythmic sperm release from the testis.

Abnormal protein in the cerebrospinal fluid of patients with a submicroscopic X-chromosomal deletion associated with Norrie disease: preliminary report.

Norrie disease is an X-linked recessive disorder characterized by congenital blindness and, in many cases, mental retardation. Some Norrie disease cases have been shown to be associated with a submicroscopic deletion in chromosomal region Xp11.3. Cerebrospinal fluid (CSF) was collected from four male patients with an X-chromosomal deletion associated with Norrie disease. CSF proteins were resolved using two-dimensional gel electrophoresis and then analyzed by computer using the Elsie V program. Our analysis revealed a protein that appears to be altered in patients with Norrie disease deletion.

Single injections of triazolam, a short-acting benzodiazepine, lengthen the period of the circadian activity rhythm in golden hamsters.

Single injections of the benzodiazepine, triazolam, induce phase shifts and cause a lengthening of the circadian activity rhythm in the golden hamster. The effect of triazolam on period depends on the phase of injection, but is not dependent on the direction of the phase shifts. Triazolam injections caused increases in period that were associated with phase advances as well as phase delays in the activity rhythm. This relationship between triazolam-induced phase shifts and changes in period is different from the relationship between light-induced phase shifts and period changes.

Hibernation in garter snakes (Thamnophis sirtalis parietalis): seasonal cycles of cold tolerance.

1. The red-sided garter snake hibernates for about six months each year in Manitoba, Canada, where winter temperatures are often as low as -40 degrees C. Mammalian hibernators typically undergo profound changes in preparation for hibernation, but little is known about corresponding changes in reptiles. 2. We tested the importance of seasonal changes in the ability of red-sided garter snakes to hibernate successfully by exposing them to winter conditions at different times of year. 3. Animals that began hibernation in the fall were more likely to survive hibernation than animals that began hibernation in either early or late summer, despite the fact that the animals were kept on seasonally constant conditions prior to hibernation. 4. We suggest that these changes are derived from endogenous components of the yearly hibernation cycle of red-sided garter snakes but that only part of the cycle proceeds endogenously, i.e. it is not a completely endogenous circannual cycle.

Social dynamics of group courtship behavior in male red-sided garter snakes (Thamnophis sirtalis parietalis).

Mating in red-sided garter snakes is characterized by the formation of mating balls. Up to 100 males simultaneously court single females. The social dynamics of the formation of these mating balls was examined to determine whether the mating balls are formed simply because of a common attraction to the female or whether males are stimulated by the mating balls themselves. A sexually attractive female garter snake appears to be even more attractive to a male when she is being courted by other males than when she is alone. Male garter snakes courted females more actively when other males were also courting the female than when they were alone with her. There is a positive correlation between the number of additional males present and the amount of courtship activity shown by the test male toward the stimulus female. The extent to which the courtship activity of the test males was stimulated by the presence of additional courting males was not influenced by how actively the additional males courted.

Persistence of infradian body weight cycles in castrated dormice (Glis glis).

Male dormice were castrated at 2 phases of their infradian body weight cycles. No consistent changes were found in cycle period, amplitude, or absolute weights of the dormice following castration. Unlike other mammals, body weights of dormice appear unaffected by castration. Although both body weight and reproductive condition vary on an infradian basis, the changes in body weight appear to be programmed independently from changes in gonadal function.