Potential of Three Trap Crops in Managing Nezara viridula (Hemiptera: Pentatomidae) on Tomatoes in Florida.

The southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae), is a serious insect pest of tomatoes in Florida. In this study, we examined the use of three species of trap crops to manage N. viridula in North Florida tomato crops in 2014 and 2015. We used striped sunflower (Helianthus annuus) (Asterales: Asteraceae) and wild game feed sorghum (Sorghum bicolor) (Poales: Poaceae) in both years, but different species of millet each year: browntop millet (Panicum ramosum) (Poales: Poaceae) in 2014 and pearl millet (Pennisetum glaucum) (Poales: Poaceae) in 2015. The number of stink bug adults collected from wild game feed sorghum exceeded the number from sunflower, and none were collected from either species of millet. Sorghum attracted a significantly higher number of adults than did striped sunflower; however, both sunflower and sorghum attracted the adults of N. viridula. Adults of the pest feed on the sorghum panicle and sunflower head (inflorescence). Although fewer stink bugs were found feeding on sunflower, the sunflower was found to be a good source of other natural enemies and pollinators and also attracted significantly greater numbers of the brown stink bug Euschistus servus (Say) (Hemiptera: Pentatomidae) (another pest of tomatoes). While this study demonstrated the effectiveness of sorghum, we recommend that sorghum be planted with another trap crop, preferably sunflower, for better preventive control of the southern green stink bug.

The effects of aging on mu and delta opioid receptors in the spinal cord of Fischer-344 rats.

Previous research has demonstrated that the antinociceptive efficacy of opioids decreases with advancing age. This study utilized radioligand binding techniques to determine if this decline is due to a change in the receptor density (Bmax) and/or affinity (measured as Kd) of the mu (mu) and/or delta (delta) opioid receptors in the spinal cord with advancing age. Saturation binding analysis with [3H][d-Ala2,N-methyl-Phe4,Gly5-ol]enkephalin (DAMGO: a mu-opioid selective agonist) and [3H]naltrindole (a delta-opioid selective antagonist) revealed no age-related changes in Bmax for either the mu or delta-opioid receptors. The Kd value for naltrindole was likewise unaffected by age. The Kd value for DAMGO however, was significantly higher in the aged group as compared with the young and mature groups, indicating a decreased affinity of spinal mu-opioid receptors for DAMGO.

The effects of aging on spinal neurochemistry in the rat.

The purpose of this study was to investigate how the aging process alters the basal levels of serotonin, norepinephrine, dopamine, and their respective metabolites in the spinal cord using high-performance liquid chromatography and electrochemical detection. Young, mature and aged male Fischer 344 rats (5-6, 15-16, and 25-26 months old, respectively) were used in all experiments. Dorsal and ventral halves of the cervical, thoracic, lumbar and sacral vertebral sections of the rat spinal cord were analyzed. The results indicate that as chronological age increases, local spinal levels of serotonin and norepinephrine decrease. These findings are discussed in terms of how age-related changes in the endogenous levels of the biogenic amines may alter the perception of pain in the elderly.

MDMA (Ecstasy) substitutes for the ethanol discriminative cue in HAD but not LAD rats.

Selectively bred high- and low-alcohol-drinking (HAD/LAD) rats were trained to discriminate the interoceptive stimuli produced by IP-administered 600 mg/kg ethanol (10% w/v in a two-lever, food-motivated operant task. Once criterion discrimination was attained, animals were tested with 3.0, 1.5, 1.0, and 0.5 mg/kg MDMA. Although no differences in alcohol discrimination were observed between the HAD and LAD animals, the HAD line was significantly more sensitive than the LAD line to the effects of MDMA. These results provide additional information to the growing body of evidence suggesting serotonergic mediation of some of the behavioral effects of ethanol.

Age-related changes in the spinal antinociceptive effects of DAGO, DPDPE and beta-endorphin in the rat.

These studies were designed to investigate how the aging process alters the spinal antinociceptive efficacy of mu (mu), delta (delta) and epsilon (epsilon) opioid receptor agonists administered intrathecally (i.t.) in rats. Various doses of the mu agonist DAGO, the delta agonist DPDPE or the putative epsilon beta-endorphin were injected i.t. in young (5-6-month-old), mature (15-16-month-old) and aged (25-26-month-old) Fischer 344 rats. Antinociception was measured using the rat tail-flick analgesiometric assay. The data demonstrated a decline in spinal opioid-induced antinociception as a function of age. For instance, the i.t. dose of DPDPE or beta-endorphin needed to produce antinociception in the 25-26-month-old rats was higher than that needed to elevate tail-flick latency in the young and mature animals. We also noted that the i.t. doses of the opioid agonists needed to produce 'antinociception' in the aged cohort were within a range of spinal doses that produced motor impairment. Apparently, the aging process alters the ability of opioid receptors to mediate antinociception. Perhaps an age-related decrease in the number and/or affinity of opioid receptor sites in the rat spinal cord accounts for these observations.

Comparison of the behavioral effects of ibogaine from three sources: mediation of discriminative activity.

Ibogaine is an alkaloid employed for its hallucinatory properties in West Central Africa which has been the subject of alleged efficacy as an aid in the interruption and treatment of chemical dependency. The major sources of the Schedule I agent are: Sigma Chemical Co., the National Institute on Drug Abuse and as NDA International Inc.'s Endabuse. The intent of the present study was to, for the first time, train rats to discriminate the interoceptive stimuli produced by (10 mg/kg, intraperitoneally administered) ibogaine. Once trained, these rats were used to investigate the dose-response effects to ibogaine from each of the three suppliers. In addition, stimulus generalization to the dopamine antagonist CGS 10476B, as well as to the serotonergically active compounds fenfluramine, TFMPP (1-(m-trifluoromethylphenyl)piperazine, DOI (1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane), MDMA (3,4-methylenedioxymethamphetamine), quipazine and LSD, was tested. The results indicate that ibogaine is readily discriminable from its vehicle and that ibogaine from each of the three supplies produced statistically similar discrimination with ED50 values ranging from 2.5 to 3.4 mg/kg. In addition, various doses of the novel drugs tested produced, at best, intermediate ibogaine-appropriate responding and, thus, no drug tested can be considered to generalize to ibogaine-like stimuli. Discussion concerns the multiple actions of ibogaine that have been cited in the scientific literature. The similarity in potency of ibogaine from three potential suppliers should allow for pre-clinical work using any of these research samples to be comparable.

P and NP rats respond differently to the discriminative stimulus effects of nicotine.

Rats selectively bred for ethanol preference, that is, alcohol-preferring (P) and -nonpreferring (NP) rats, were trained to discriminate the interoceptive stimuli produced by IP-administered 1,000 mg/kg ethanol (10% v/v) in a two-lever, food-motivated, operant task. Once criterion performance was attained, dose-response experiments indicated an ED50 value for P rats = 354.1 mg/kg, whereas NP rats generated an ED50 value of 495.1 mg/kg, not significantly different from each other. In contrast to these similar sensitivities to ethanol, administration of doses of nicotine (0.4-1.2 mg/kg, SC) indicated that P rats were significantly more sensitive to the ethanol-like effects of nicotine than were NP rats. The results provide additional evidence for a possible hereditary co-occurrence of alcohol and nicotine sensitivity.

The NMDA receptor antagonist MK-801 produces ethanol-like discrimination in the rat.

Two groups of rats, one derived from N/Nih stock and the second from the (putatively) serotonin-compromised Fawn-Hooded line, were trained to discriminate ethanol from its vehicle in a drug discrimination paradigm. Once each of the two groups attained discrimination criterion, dose-response relationships with lower doses of ethanol indicated that the Fawn-Hooded rats were less sensitive (ED50 value = 579.5 mg/kg) than the N/Nih rats (ED50 = 371.4 mg/kg). Testing of various doses of the NMDA (N-methyl-D-aspartate) receptor antagonist MK-801 produced complete generalization in each group of animals, with a similar difference in ED50 values between N/Nih and Fawn-Hooded lines. These results extend previous ethanol-to-MK-801 generalization reported in pigeon, and are discussed in light of a possible NMDA-mediated contribution to the ethanol-induced discriminative stimulus cues.

Differential effects of nicotine but not cathinone on motor activity of P and NP rats.

The locomotor stimulatory effects of nicotine (0.4 and 0.8 mg/kg) and cathinone (0.5 and 1.0 mg/kg) were assessed in alcohol-preferring (P) and -nonpreferring (NP) rats. Whereas P rats demonstrated enhanced (0.8 mg/kg) or no change (0.4 mg/kg) in spontaneous locomotor activity (SMA) to nicotine, NP animals showed no change (0.4 mg/kg) or depression of activity (0.8 mg/kg). However, following cathinone administration both P and NP rats exhibited an increase in SMA. The above results are discussed in light of the genotypic variations between P/NP rats and the potential mediation of differential neurotransmitter effects in the two lines.

The effects of preexposure to the drug on state dependent retention.

The present experiment examined whether previous experience with a drug would decrease the potential of the drug to produce state dependent retention (SDR) for a passive avoidance response in rats. In the first experiment, a single injection of sodium pentobarbital (20 mg/kg) given on six consecutive days before the training day slightly reduced, but did not block, pentobarbital-induced SDR. In Experiment Two, four preexposure injections of 5 IU/kg insulin reduced the magnitude of memory loss produced by administration of the hormone prior to training. As with pentobarbital, however, preexposure to insulin did not completely block the amnestic effect of the hormone. A subsequent experiment demonstrated that the decrease in the strength of insulin-induced SDR in insulin preexposed rats was not the result of enhanced acquisition. Collectively, these data indicate that noncontingent preexposure to an amnestic treatment may decrease the magnitude of memory loss that would normally result from the administration of that treatment during training.

Pediatric update #11. Congenital radioulnar synostosis. A new technique for derotational osteotomy.

Hyperpronation deformity due to congenital radioulnar synostosis has previously been managed by derotational osteotomy through the synostosis, while stabilization has been achieved with K-wires and a long arm cast. The technique presented here uses a small external fixation device that allows precise rotational correction and affords adequate stabilization yet avoids cast immobilization.

Study of U.S. Medical School Applicants, 1977--78.

This annual report on applicants to the 1977--78 U.S. medical school freshman class describes the first substantial decline in applicants during the past quarter century. Since the decline was accompanied by the opening of several new medical schools, the chances of gaining admission improved to 39 percent, the highest in six years. For applicants making their first attempt the acceptance rate was 43 percent. There was no loss of qualified applicants, however; the 1977--78 pool presented record-high entrance test scores and undergraduate college grades. In the report comparisons are made with activity in 1974--75--the peak year for medical school spplicants--in order to measure the impact of the decline on individual medical schools and geographical regions and on various applicant subpopulations.

Study of U.S. medical school applicants, 1976--77.

This annual study contains descriptive statistics on applicants to the 1976--77 freshman classes of U.S. medical schools. In contrast to the growth rates of the early 1970s, the total number of applicants declined slightly for the second successive year. However, comparisons with past applicant pools show a continued increase in the annual number of women applying and a modest increment over the previous year in applicants from minority groups. For the first time in the annual series the 1976--77 study includes data on applicants' size of hometown and summarizes information collected on marital status, country of citizenship, and undergraduate degree level.

Study of U.S. medical school applicants, 1975-76.

This annual descriptive study provides statistics on the demographic and background characteristics, academic ability, and career plans of applicants to the 1975--76 first-year class. Comparisons with the preceding year's applicant pool, traditionally the focus of the applicant study series, show a slight decline in the size of the pool, a continued increase in the number of women applicants and acceptees, and a slightly higher acceptance rate for all applicants. The study has been expanded by reinstating data on the socioeconomic background of applicants and by providing general summaries on topics such as career plan preferences of applicants. New to the series is an analysis of "in-phase" applicants, that is, undergraduate college seniors applying to medical school for the first time. The conclusion outlines those activities of the Association of American Medical Colleges over the past year that are related to the medical school admissions process.