The relationship between alcohol dosage and performance decrement in humans.

The effects of alcohol on human perceptual, cognitive and motor performance was assessed in a battery of tests, and the dose-response relationships for alcohol, important for the study of drug-alcohol interactions, established.

Hysteria in childhood: a note on Proctor's incidence figures 27 years later.

Confirmation of Proctor's 1958 estimate of high incidence of hysterical phenomena among a rural child psychiatric population is provided by recent observations on a small, random sample of children referred for psychological assessment in Australia. Demographic and other similarities between the two groups are discussed, and tentative directions for treatment are noted.

Role of associated bacteria in growth and toxicity of cultured benthic dinoflagellates.

Clonal cultures of the toxic benthic dinoflagellate Ostreopsis lenticularis isolated from the coastal waters of southwest of Puerto Rico show peak toxicities during the stationary phase of growth, correlated with significant increases in bacteria directly associated with these cells. The specific toxicity (MU/mg) of dinoflagellate extracts in control cultures increased 340% during the static phase of culture growth, while those cultures treated with antibiotics that inhibit prokaryote protein synthesis showed no significant increase in toxicity during this phase of culture growth. There was a significant decrease in the diversity of dinoflagellate associated bacterial strains in antibiotic treated cultures. These data indicate that associated bacteria play a role in toxin production by dinoflagellate-bacteria consortia when grown in laboratory culture.

The Children's Depression Scale. A study of its validity.

The validity of the Children's Depression Scale and of its parent-report version were examined on a sample of normal and clinically referred adolescents. The CDS and CDS-A discriminated adequately between clinical and non-clinical Ss, as well as between depressed and non-depressed. Only the CDS discriminated between depressed and 'sad', i.e. parental report did not discriminate between these two groups. A high correlation was found between the CDS and the Children's Depression Inventory. Internal consistency of the scale was found to be adequate. However, no support was found for the subscale structure of the CDS as proposed by its authors.

Validation of the Children's Depression Scale and the Children's Depression Inventory in a prepubertal sample.

The validity of the Children's Depression Scale (CDS), the Children's Depression Inventory (CDI) and their respective parent report versions was assessed in a sample of outpatient and normal control prepubertal children. Scores from the child and parent versions of both scales significantly discriminated between children independently diagnosed as depressed and those with nondepressive disorders. Both measures also distinguished depressed and dysphoric children. Contrary to the findings of earlier studies, a significant rate of agreement was found between the reports provided by the children and their parents. The results suggest that the influence of the child's age and clinical status on reporter correspondence patterns should be considered more exhaustively in future research.

Bedwetting and psychopathology in adolescents.

OBJECTIVE: To ascertain whether nocturnal enuresis in adolescents is associated with depression, hyperactivity, oppositionality, conduct and peer problems. METHODOLOGY: This was investigated cross-sectionally in adolescents aged 12-16 years from a community sample (n = 528) and a clinically referred cohort (n = 2325) using parents' reports. RESULTS: Referred adolescents were 7 times more likely to wet the bed than their community counterparts. There was a small but significant association between nocturnal enuresis and hyperactivity. Depressed adolescents were half as likely to wet the bed as those without depression. Bedwetters had more problems relating to peers but were not disliked more often. There was no association between bedwetting, oppositionality, conduct problems and gender. Gender differences disappeared when the effect of hyperactivity was controlled. CONCLUSIONS: Clinicians need to inquire about symptoms of attention deficit hyperactivity disorder in adolescents who present with enuresis and vice versa.

The effect of caffeine on human performance, alone and in combination with ethanol.

The effect of caffeine (300 mg/70 kg) on cognitive, perceptual and motor functions was investigated both alone and in combination with ethanol (0.75 g/kg) in 68 healthy student volunteers of both sexes. A test battery consisting of standing steadiness, simple and complex reaction time, manual dexterity, numerical reasoning, perceptual speed and verbal fluency was used. Placebos for both drugs were included. Caffeine was administered in decaffeinated coffee immediately after finishing drinking the alcoholic beverage. A peak plasma ethanol concentration of 92 +/- 4 mg/100 ml occurred at 40 min which was not modified by caffeine. Caffeine did not antagonise the ethanol-induced decrement in performance except in the reaction time tests. Caffeine alone caused a significant increase in body sway at 40 min.

Problems and competencies reported by parents of Australian and American children.

We compared problems and competencies reported for 2600 randomly selected nonreferred children in Sydney and the U.S.A. Sydney children scored significantly higher on 82 problem items, with a mean total problem score of 31.6 versus 20.1 for the U.S.A. Nevertheless, item scores correlated 0.92 between countries, most differences between competence scores were small, and patterns were similar for sex, age, socioeconomic status, and internalizing versus externalizing problems. Although higher clinical cutoffs may be needed in Sydney, the similarity of patterns in scores permits calibration of the Child Behavior Checklist between Sydney and the U.S.A. Sex differences found in seven cultures were summarized.

Associated bacterial flora, growth, and toxicity of cultured benthic dinoflagellates Ostreopsis lenticularis and Gambierdiscus toxicus.

The growth, toxicity, and associated bacterial flora of 10 clonal cultures of the toxic benthic dinoflagellates Ostreopsis lenticularis and Gambierdiscus toxicus isolated from the coastal waters of southwest Puerto Rico have been examined. Clonal cultures of O. lenticularis grew more rapidly and at broader temperature ranges than those of G. toxicus. All five Ostreopsis clones were toxic, while only one of the five Gambierdiscus clones was poisonous. The degree of toxicity among poisonous clones was highly variable. The number of associated bacterial genera and their frequency of occurrence were quite variable among clones of both dinoflagellate genera. Bacterial isolates represented six genera (Nocardia, Pseudomonas, Vibrio, Aeromonas, Flavobacterium, and Moraxella) in addition to coryneform bacteria. Extracts of dinoflagellate-associated bacteria grown in pure culture were not toxic. Gambierdiscus clones were characterized by the frequent presence of Pseudomonas spp. (four of five clones) and the absence of coryneforms. In O. lenticularis, only one of five clones showed the presence of Pseudomonas spp., and Moraxella sp. was absent altogether. Detailed analyses of toxicity and associated microflora in a selected Ostreopsis clone, repeatedly cultivated (four times) over a period of 160 days, showed that peak cell toxicities developed in the late static and early negative culture growth phases. Peak Ostreopsis cell toxicities in the stationary phase of culture growth were correlated with significant increases in the percent total bacteria directly associated with these cells. Changes in the quantity of bacteria directly associated with microalgal cell surfaces and extracellular matrices during culture growth may be related to variability and degree of toxicity in these laboratory-cultured benthic dinoflagellates.

The interaction of fructose, dextrose and ethanol on human performance.

1. The effects of orally administered fructose (1.2 g.kg-1) and dextrose (1.2 g.kg-1) on the performance decrement induced by ethanol (1.0 g.kg-1) in a series of perceptual, cognitive and motor tests were studied in twelve healthy, paid University student volunteers using a double-blind cross-over design. Ethanol was consumed at a constant rate over 20 min and the hexoses or placebo were given approximately 40 min later. 2. The peak blood ethanol concentration was attained earlier when the subjects also received either hexose than after placebo but although its rate of fall was unaffected, significantly lower ethanol concentrations were encountered in the hexose-treated groups in the latter part of the experiment. 3. In general, the subjects were impaired to a slightly lesser degree when they received a combination of hexose and ethanol than after ethanol alone. There were no differences between the effects of fructose and dextrose. 4. The results do not support contentions that fructose is able to accelerate a return to sobriety and observed differences between hexose and placebo-treated groups were attributed to an effect on the absorption of ethanol rather than its metabolism.

The interaction between ethanol and antihistamines: 2. Clemastine.

Eighty paid student volunteers (35 male, 45 female) were used in an experiment to investigate the effects of a therapeutic dose of clemastine (1 mg) alone and in combination with a social dose of ethanol (0.54 g/kg) on perceptual, cognitive and motor functions. Both drugs were given orally. Clemastine did not significantly modify performance when given alone, and the performance decrements induced by ethanol were not enhanced by clemastine premedication.

The effect of disodium cromoglycate on human performance, alone and in combination with ethanol.

Seventeen paid volunteer subjects were used in a double-blind crossover experiment to investigate the effects of disodium cromoglycate (DSCG), alone and in combination with ethanol, on human perceptual, cognitive and motor performance. DSCG (40 mg) had little effect when given alone. When administered with ethanol (0-75 g/kg), DSCG did not significantly modify the ethanol-induced decrement in performance except in the complex reaction time test.

The interaction between ethanol and antihistamines. 1: Dexchlorpheniramine.

Thirteen paid student volunteers (9 male, 4 female) were used in a double-blind crossover experiment to investigate the effects of a therapeutic dose of dexchlorpheniramine alone, and in combination with a social dose of ethanol on perceptual, cognitive and motor functions. Both ethanol (0.75 g/kg) and dexchlorpheniramine (4 mg/70 kg) were given orally. Although a synergistic effect of dexchlorpheniramine with ethanol was only observed in some of the tests, a delayed recovery from the effects of the combination was noted. Subjective data indicated that the sedative effects of dexchlorpheniramine were more pronounced in the presence of ethanol.

The interaction of ethanol and delta9-tetrahydrocannabinol in man: effects on perceptual, cognitive and motor functions.

Twelve paid student volunteers (8 male, 4 female) were used in a double-blind crossover experiment to investigate the effects of delta9-tetrahydrocannabinol (THC) alone, and in combination with ethanol, on human perceptual, cognitive and motor functions. Both THC (10 mg/70 kg) and ethanol (0-5 g/kg) had little effect when administered alone. The combination of drugs, however, induced a significnat decrement in performance in some of the tests and this interaction was considered to be at least additive. The peak blood ethanol concentration was higher (P = 0-05) when subjects received both ethanol and THC than when they received ethanol alone.