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Biomedical subjects

R L Collins

Publications and source records attributed to R L Collins.

At least 37 records · Page 2Linked to original sources
PubMed1998

Simultaneous polydrug use among teens: prevalence and predictors.

The use of two or more substances in combination, simultaneous polydrug use (SPU), is a particularly dangerous form of drug use that appears to be established by late adolescence. We examined the prevalence of SPU in a diverse sample of 12th graders, and identified risk and protective factors for SPU that are present at 10th grade. We also tested for differences in SPU across race and gender, and explored the basis for observed differences. Our goals were to determine the extent of SPU problems in different groups and how to address these problems. Twenty-nine percent of participants had engaged in SPU in the past year. The best predictors of alcohol/marijuana SPU were a pro-drug environment, pro-drug beliefs, social deviance, and family disruption; only a pro-drug environment was predictive of hard drug SPU. Women were far less likely to combine marijuana and alcohol than were men. Asian Americans were less likely to combine alcohol and marijuana than were other racial groups, apparently due to their advantaged standing on all predictors of this behavior. African Americans were less likely to use hard drugs in combination than were other groups. Overall, polydrug use is a substantial problem for older teens. Broader drug-use prevention programs may be sufficient to address SPU involving gateway drugs, but reducing drug availability appears central to addressing hard drug SPU.

Adolescent↗
PubMed1998

Ecological momentary assessment in a behavioral drinking moderation training program.

We assessed predictors of self-reported excessive drinking (> 5 drinks) in a sample of heavy drinkers. Participants were randomly assigned to moderation training or a waiting-list control condition. They were trained in ecological momentary assessment (EMA) involving self-monitoring of drinking and other variables on a small hand-held computer, the electronic diary (ED). During the 8-week study, participants were compliant in their use of the ED for both random prompts and the entry of data related to specific drinking episodes. Generalized estimating equations were used to fit models involving predictors related to past history of drinking, aspects of the training program, drinking restraint, and episode-specific mood. The models indicated robust predictors of decreased and increased drinking. Our results suggest that EMA is a useful methodology for assessing drinking and related behaviors.

Adult↗
PubMed1996

Paw preference and intra-/infrapyramidal mossy fibers in the hippocampus of the mouse.

The size of the intra-/infrapyramidal mossy fiber projections (IIP-MF) and their left/right asymmetry were assessed in 86 mice of either sex, including 26 animals from two mouse lines bred for strong or weak paw preference, 38 mice of a randomly bred F3 generation derived from an eight-way cross, and 22 mice with variably sized corpora callosa in which only the left hippocampus was measured. Prior to morphometry, all mice were tested for paw preference. In addition, we compared the strain means in paw preference as observed in nine inbred mouse strains with known differences in their IIP-MF distribution. Mice bred for strong paw preference had a 70% larger IIP-MF projection than weakly lateralized and dyscallosal mice; random-bred mice fell in-between the extremes. The individual scores of the strength of paw preference were positively correlated with the extent of the IIP-MF. Among the inbred strains, the extent of the IIP-MF was similarly correlated with the strength of paw preference. The acallosal mice showed a significant negative correlation between extent of the IIP-MF projection and test-retest reliability of paw use. The left-right asymmetry of the IIP-MF was significantly and positively correlated with the direction of paw preference in the entire sample. We conclude that size and asymmetry of the IIP-MF projection are some of the many factors influencing the direction of paw preference and its strength, albeit moderately. We hypothesize that mice with larger IIP-MF projections use a given paw more consistently, being perhaps more resistant to interferences, and that left-right asymmetries of the IIP-MF may bias and/or reinforce an initial choice of a paw. In addition, the data provide another example of correlations between IIP-MF variations and nonspatial behavior.

Animals↗
PubMed1996

Comparison of saline infusion sonography with office hysteroscopy for the evaluation of the endometrium.

OBJECTIVE: Intrauterine infusion of saline solution during transvaginal ultrasonography enhances visualization of the endometrium. We compared the accuracy and pain rating of saline infusion sonography with those of flexible office hysteroscopy. STUDY DESIGN: The uterine cavities of 130 patients with abnormal bleeding were evaluated by two physicians in an office setting. Findings of endometrial polyps, submucous myomas, synechiae, endometrial hyperplasia, or cancer were recorded independently and subsequently compared. Patients rated their pain after each procedure. RESULTS: Both procedures were performed in 113 of 130 patients. With saline infusion sonography pathologic findings were identified in 61 patients (54%). For all findings combined, sensitivity was 0.96 and specificity was 0.88, compared with hysteroscopy. The results of saline infusion sonography and hysteroscopy did not differ significantly (p = 0.18). The former was less painful for patients than hysteroscopy (p < 0.0001). CONCLUSION: Saline infusion sonography is an accurate and well-tolerated method to evaluate abnormal uterine bleeding, compared with hysteroscopy.

Adult↗
PubMed1996

Ovulation induction using s.c. pulsatile gonadotrophin-releasing hormone: effectiveness of different pulse frequencies.

To determine the ovarian response to a fixed dose of gonadotrophin-releasing hormone (GnRH) administered s.c. at four different pulse frequencies, 20 patients with hypothalamic amenorrhoea were treated over 41 cycles using a dose of 20 ng/kg/pulse. These patients were randomly assigned to receive GnRH at pulse frequencies of 60, 90, 120 or 180 min. GnRH was administered s.c. using portable infusion pumps. Subjects were paid volunteers with a diagnosis of hypothalamic amenorrhoea. All patients had low to less than detectable serum concentrations of luteinizing hormone and follicle stimulating hormone on 8 h serial sampling, and normal serum concentrations of prolactin and androgen, including androstenedione, testosterone and dihydroepiandrosterone sulphate. Six of the 20 patients were enrolled in the protocol to achieve a pregnancy, while 14 were volunteers using a barrier method of contraception. Highest ovulation rates were achieved using pulse frequencies of 90 and 120 min (60 and 88% of cycles respectively). Ovulation occurred significantly less often with frequencies of 60 and 180 min (12 and 38% respectively; P </= 0.05). Pregnancy was achieved in four of the six patients who desired a pregnancy at pulse frequencies of 90 (three out of three) and 120 (one out of one) min. No pregnancies occurred at pulse frequencies of 60 (none out of one) and 180 (none out of one) min. When ovulatory cycles were considered, oestradiol concentrations were not different among pulse frequencies but varied significantly between ovulatory and anovulatory cycles. Integrated luteal progesterone concentrations for 90 and 120 min frequencies (118.26 +/- 25.89 and 125.15 +/- 32. 10 ng/ml/luteal phase respectively) were significantly higher than for 60 and 180 min (80.1 +/- 48.2 and 42.75 +/- 26.48 ng/ml/luteal phase respectively). Ovulation may be induced by a broad range of pulse frequencies. Pulse frequencies of 90 or 120 min for s.c. GnRH appear to induce more reliably the sequence of follicular development, ovulation and normal luteal function than frequencies of either 60 or 180 min. Significantly higher ovulation rates occurred at 90 and 120 min by s.c. administered GnRH.

Adult↗
PubMed1996

Drinking restraint and alcohol-related outcomes: exploring the contributions of beverage instructions, beverage content and self-monitoring.

OBJECTIVE: We examined the role of drinking restraint (temptation and restriction), beverage instructions and content and self- monitoring in alcohol-related outcomes (consumption, subjective intoxication and blood alcohol concentration [BAC]) in a sample of moderate-to heavy-drinking young men. METHOD: Male social drinkers (N = 132) participated in an individualized taste-rating task (TRT), an unobtrusive method for determining ad libitum alcohol consumption. Beverages were presented using the format of the balanced placebo design (BPD), in which subjects' expectation of an alcoholic versus a non- alcoholic beer was crossed with their receipt of an alcoholic versus a nonalcoholic beer. During a single 30-minute drinking occasion, each subject sampled two beers and rated their taste characteristics on a computer. RESULTS: Consumption during the TRT, ratings of subjective intoxication and postdrinking BAC, served as criterion variables in regressions in which BPD beverage condition, the two aspects of drinking restraint, self-monitoring, and their interactions, served as the predictors. The results indicated that TRT consumption was mainly a function of the temptation to drink (an aspect of restraint). As expected, assignment to the conditions of the BPD predicted subjective intoxication and BAC. Self-monitoring did not have an impact on any of the alcohol- related outcomes. CONCLUSIONS: The results for TRT consumption suggest that drinking restraint, particularly the temptation to drink (i.e., view the regulation of intake as difficult and/or drink to repair negative affective states), enhances the consumption of social drinkers during a single drinking occasion. Consistent with previous research, the conditions of the BPD predicted some alcohol-related outcomes.

Adult↗
PubMed1996

Tenidap in patients with rheumatoid arthritis. A 4-week, placebo-controlled study.

The present double-blind, placebo-controlled study was conducted to compare the safety and efficacy of tenidap in patients with rheumatoid arthritis (RA). Patients with flare of active RA following NSAID withdrawal were randomized to receive either placebo (n = 67) or tenidap (n = 131; 40-200 mg/day). The mean changes from baseline in efficacy and biochemical variables were compared between treatment groups at endpoint (4 weeks). The improvements in four of the five primary efficacy variables were significantly greater in the tenidap group compared with the placebo group (p < 0.01). Tenidap was also associated with an 18% reduction in erythrocyte sedimentation rate (ESR) and a marked, 51%, reduction in serum C-reactive protein (CRP) level, both of which were significantly greater than the changes in the placebo group (p < 0.05). The percentage of patients who discontinued because of side effects was the same in both groups (3%). In conclusion, tenidap 40-200 mg/day was effective and well tolerated in the treatment of patients with RA for 4 weeks.

Administration, Oral↗
PubMed1996

The role of ethnic versus nonethnic sociocultural factors in substance use and misuse.

Substance use research in the United States has focused on ethnicity/race to the detriment of studying the role of nonethnic sociocultural factors. Reliance on politically defined ethnic categories has not added to knowledge on the etiology, prevalence, prevention, or treatment of substance use and misuse. Rather it has reflected the preoccupation with race/ethnicity in the larger United States society and has contributed to further stereotyping of non-European ethnic groups. Ethnicity serves as a proxy for a number of sociocultural factors (e.g., socioeconomic status) that are linked to substance use. To make progress in understanding substance use and misuse, researchers must move away from the simplistic reliance on ethnic labels to a more complex understanding of the impact of the sociocultural variables that such labels represent.

Cross-Cultural Comparison↗
PubMed1995

Tenidap in rheumatoid arthritis. A 24-week double-blind comparison with hydroxychloroquine-plus-piroxicam, and piroxicam alone.

OBJECTIVE: To compare the clinical efficacy, effect on serum C-reactive protein (CRP), serum amyloid A (SAA), and plasma interleukin-6 (IL-6) levels, and safety of tenidap with a combination of hydroxychloroquine-plus-piroxicam, and piroxicam alone, in the treatment of rheumatoid arthritis (RA) patients. METHODS: A double-blind, randomized, multicenter study in which patients with active RA were treated with tenidap 120 mg/day, hydroxychloroquine 400 mg/day and piroxicam 20 mg/day, or piroxicam alone 20 mg/day, for 24 weeks. RESULTS: At weeks 12 and 24, tenidap produced greater improvements than piroxicam based on 5 primary efficacy parameters; this improvement showed statistical significance in 4 of the 5 measures at week 12, and in 3 of the 5 measures at week 24. Clinical improvements in the hydroxychloroquine-plus-piroxicam-treated with tenidap. Compared with piroxicam, tenidap was associated with significantly greater reductions in serum CRP concentrations at 4, 12, and 24 weeks, and significantly greater reductions in SAA concentrations at weeks 12 and 24. The decrease in SAA concentrations was also significantly greater at weeks 4 and 24 in the tenidap-treated group than in the hydroxychloroquine-plus-piroxicam-treated group. Significant reductions in plasma IL-6 levels were observed at weeks 4, 12, and 24 within the tenidap group, and at week 24 within the hydroxychloroquine-plus-piroxicam-treated group. The overall occurrence of side effects, including gastrointestinal side effects, was similar in all 3 treatment groups. A small proportion of tenidap-treated patients (6.4%) manifested mild, nonprogressive, reversible proteinuria of presumed renal proximal tubular origin, and 3-4% of patients had elevated transaminase levels. CONCLUSION: In the treatment of patients with RA, tenidap is as effective as the combination of hydroxychloroquine-plus-piroxicam, and is more effective than piroxicam alone; moreover, tenidap's safety profile is comparable to that observed with piroxicam alone, and with hydroxychloroquine-plus-piroxicam. The clinical response observed in this study, as well as the prompt decreases in acute-phase protein levels of CRP and SAA, and in plasma IL-6 levels, suggest that tenidap represents a new type of antiarthritic medication, with properties similar to, but not identical to, a therapeutic combination of a nonsteroidal antiinflammatory drug with disease-modifying antirheumatic drugs.

Adult↗
PubMed1994

Covering embryo cultures with mineral oil alters embryo growth by acting as a sink for an embryotoxic substance.

PURPOSE: Assisted reproductive technologies require the use of culture media for gametes and embryos. Culture media and conditions intended for use in human in vitro fertilization are tested prior to use by evaluating their ability to support normal development of mouse embryos. RESULTS: Development to blastocysts of two-cell mouse embryos was equivalent for embryos cultured in center well dishes alone (93 +/- 10%, mean +/- SD) and embryos cultured in center well dishes with an overlay of 1 ml of mineral oil (94 +/- 5%). In contrast, no development of two-cell-stage mouse embryos occurred in an embryotoxic medium when cultured in center well dishes. However, when this medium was covered with an overlay of mineral oil, development to blastocyst was no different than that of controls (96 +/- 5%). Similar results were found with cultures of one-cell-stage mouse embryos. CONCLUSION: These results indicate that in some circumstances the presence of mineral oil can significantly alter the outcome of embryo culture. Further, these results reinforce the necessity of directly testing the exact culture conditions to be used for assisted reproductive technologies.

Analysis of Variance↗
PubMed1994

Psychological screening and the success of donor insemination.

In a previous case series, a psychologist's rating of couples' emotional adjustment and readiness for donor insemination was predictive of pregnancy rates. We attempted to replicate this finding with an extended series of 120 consecutive couples in which each spouse filled out questionnaires when evaluated for donor insemination. The Stress and Infertility Questionnaire measured specific attitudes and anxieties about donor insemination. The Brief Symptom Inventory assessed psychological distress. The Dyadic Adjustment Scale measured marital happiness. A psychologist used these questionnaires to rate the couple's overall adjustment in regard to donor insemination. Those couples rated as distressed had a session of psychological counselling. Outcome was reviewed at a mean of 20 months after evaluation, with categories of pregnancy, continuing donor insemination, failure to begin the programme, or dropped out. For the 120 couples overall, psychological factors did not predict pregnancy outcome. Younger age of the wife did predict higher pregnancy rates.

Adaptation, Psychological↗
PubMed1994

Affective and behavioral reactions to the violation of limits on alcohol consumption.

The limit violation effect (LVE) was studied by inducing male social drinkers to consume either more or less beer than their prestated limit on alcohol intake. Affective and behavioral reactions to the violation of drinking limits were mediated by attributional style and aspects of drinking restraint. Subjects who reported greater than average levels of self-blaming attributions, restrictions on alcohol intake and cognitive preoccupation with alcohol became depressed and angry after the violation of drinking limits. In contrast to the hypothesized excessive-drinking component of the LVE, subjects who experienced negative affective reactions to the violation ordered fewer shots in a subsequent whiskey-tasting task. Possible conceptual and methodological reasons for observing only the affective component of the LVE are discussed.

Adult↗
PubMed1994

Psychopharmacological effects of alcohol on time perception: the extended balanced placebo design.

Time perception is affected by the pharmacological action of many drugs, but the contribution of expected effects of drugs has not been considered. A new design, the extended balanced placebo design (EBPD), is presented to study both the pharmacological and expected effects of alcohol on time perception. The EBPD makes it possible to examine the effects of alcohol across a broad range of expected and pharmacological doses. By contrast, the domain of inquiry was limited to low doses of alcohol in the original balanced placebo design. The design was later modified to study higher doses, but the control and the pure drug and expectancy conditions were sacrificed in the transformation. In the EBPD, however, any realistic combination of the expected and actual dose of alcohol can be studied, while retaining pure drug and expectancy conditions. The EBPD was tested in the present study with respect to its psychopharmacological effectiveness and the effects of alcohol on time perception. The design was effective in terms of three manipulation checks: blood alcohol concentration, subjective intoxication and postexperimental beliefs about the alcohol content of the beverage consumed. In addition, the expected and actual doses of alcohol interacted over time to evidence active compensation for the pharmacological effects of alcohol on time perception. Finally, a covariance structure model was confirmed in which the expected and actual doses of alcohol increased the perceived rate of time passage, which in turn lengthened objective estimation of a one-second interval.

Adult↗
PubMed1994

On the enhancement of creativity by alcohol: pharmacology or expectation?

Creative individuals may use psychoactive drugs to enhance their ability to produce creative works, but it is difficult to differentiate the pharmacological effects from other influences. Part of the problem is that creativity defies any simple definition, making it hard to determine when or how much creativity is evident. The other major obstacle is that life circumstances are confounded with the propensity to use drugs (including alcohol), so the causal relation of drugs to creativity is uncertain. We examined this question by an experiment in which subjects were asked to creatively combine pictures of wildflowers that were implicitly organized around a set of three dimensions: color, shape, and number. Pharmacological and expected effects of alcohol were dissociated in the experiment by using the balanced placebo design (BPD). The results showed no pharmacological effect of alcohol on the creative combinations that subjects produced. However, the novelty and structural recombination of the wildflower arrangements were enhanced when subjects thought they had consumed alcohol, whether or not they had actually done so. Implications for measuring creativity and the possible motivation to use drugs for creative effect are discussed.

Adult↗
PubMed1993

Genetic and behavioral tests of the McManus hypothesis relating response to selection for lateralization of handedness in mice to degree of heterozygosity.

McManus advanced a genetic hypothesis to explain differences of lateralization between HI and LO lines of mice selectively bred for degree of handedness. It states that lateralization is a function of heterozygosity. Specifically it predicts that (a) the HI line will be more heterozygous than the LO line and (b) populations with a greater average heterozygosity (AH) will be more strongly lateralized. Both genetic and behavioral predictions were tested here. Results using coat color and biochemical variants show that AH in the HI line is somewhat less (not greater) than that in the LO line. The handedness of HET control mice and HI by LO reciprocal hybrids, where AH is greater than that of the HI line, exhibits lessened (not greater) lateralization. Results reject the heterozygosity hypothesis. A model for the inheritance of human handedness that accounts for difficulty in detecting heritable differences in degree of asymmetry is presented.

Animals↗
PubMed1992

The effects of early experience on callosal development and functional lateralization in pigmented BALB/c mice.

A proportion of animals of the BALB/c inbred mouse strain have an unusually small (sometimes absent) midsagittal area of the corpus callosum (CC). In this study, we used a large sample of both males and females (total n = 198) from a pigmented congenic BALB/c line to investigate the relations among preweaning handling, area of CC, and direction and degree of lateralization as measured by Collins' paw preference task. Twenty litters were handled daily from the day after birth until day 25 (weaning) according to Denenberg's procedure and 18 litters were left undisturbed until weaning. All animals were tested for degree and direction of paw preference in a modification of Collins' apparatus at about 60 days and measures taken on CNS structures at 100 days of age. There were no handling or sex effects on degree or direction of paw preference or on the extent of CC defects, but for animals in the normal range (CC > or = 0.7 mm2), those which had been handled had significantly smaller callosa. No significant differences were detected between right and left hemisphere weights, and these measures did not appear to be related to the behavioural measures. There was no significant correlation between CC area and degree of paw preference nor was there any relationship between total agenesis and degree of handedness. This last result is particularly interesting in light of recent evidence that ILn/J mice, all acallosal, are exclusively ambilateral.

Animals↗
PubMed1992

Confirmation of the influence of a chromosome 7 locus on susceptibility to audiogenic seizures.

Mouse strain differences in susceptibility to audiogenic seizures (AGS) are due to allelic differences at multiple genetic loci. Three loci that influence susceptibility to AGS have been mapped on Chromosomes (Chr) 12, 4, and 7 (Asp-1, Asp-2, and Asp-3, respectively). Here we report evidence that confirms linkage of Asp-3 to c on Chr 7 and parental effects on AGS susceptibility, but not genomic imprinting of Asp-3.

Acoustic Stimulation↗