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Biomedical subjects

C L Williams

Publications and source records attributed to C L Williams.

At least 127 records · Page 7Linked to original sources
PubMed1994

Peer participation in Project Northland: a community-wide alcohol use prevention project.

This paper describes the rationale, conceptual framework, and program components of a peer participation program for prevention of alcohol use among young adolescents. The peer participation program was one component of Project Northland, a community-wide program that seeks to prevent or delay onset of alcohol use among a cohort of young adolescents. The peer participation program, implemented in 20 northeastern Minnesota schools when students were in seventh grade, consisted of student groups who planned supervised, alcohol-free activities for themselves and their classmates. Program goals included 1) providing peer leadership and social support for non-use of alcohol, 2) creating opportunities for alternative behaviors to alcohol use, thereby 3) creating a norm of non-use among young adolescents.

Adolescent↗
PubMed1994

Item level improvements for use of the MMPI with adolescents.

The decision to develop a separate adolescent form of the Minnesota Multiphasic Personality Inventory (i.e., the MMPI-A) raised questions about continued use of 20 original items that seemed unnecessarily ambiguous in content when employed with younger students (Ss). The responses of 362 academically gifted boys, aged 14 to 17 years, from an urban Catholic high school were compared on the experimental 704-item Form TX of the MMPI and a form containing 20 rewritten and 9 control items. The psychometric properties of the rewritten items indicated the same or better performance than that on the original versions while improving the items' face validity and reducing item ambiguity. Responses from 321 Ss to a follow-up questionnaire suggested eliminating offensive or irrelevant items and reducing the test's length would increase acceptance of the MMPI-A.

Adolescent↗
PubMed1994

Development of MMPI-A alcohol/drug problem scales.

The present study introduces two new scales for the assessment of alcohol and other drug problems developed from the new Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A), including the rationally constructed Alcohol/Drug Problems Acknowledgement Scale (ACK) and the empirically-derived Alcohol/Drug Problems Proneness Scale (PRO). Validity of these scales is examined by comparing scores from a sample of adolescents hospitalized for alcohol and other drug problems with a normative sample of adolescents and with a sample of adolescents in psychiatric inpatient treatment. Results suggest that ACK and PRO show promise in the detection and description of alcohol and other drug problems in young people. Comparisons of ACK and PRO with other adult-derived MMPI-2 scales (e.g., the MacAndrew Alcoholism Scale, MAC-R and the Addiction Potential Scale) provide support for the practice of developing age-appropriate instruments for adolescents.

Adolescent↗
PubMed1994

SNF9007: a novel analgesic that acts simultaneously at delta 1, delta 2 and mu opioid receptors.

Intracerebroventricular administration of the synthetic cholecystokinin analog SNF9007 (Asp-Tyr-D-Phe-Gly-Trp-[NMe]-Nle-Asp-Phe-NH2) produced antinociception in the mouse hot-plate and warm water tail-flick tests. The mechanisms of its analgesic actions were assessed by administering antagonists selective for CCK (cholecystokinin octapeptide, sulfated)-A and CCK-B receptors, as well as specific antagonists for the mu opioid receptor (D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2, 1 microgram i.c.v.), the delta-1 opioid receptor [D-Ala2-Leu5,Cys6]enkephalin, 4.57 nmol i.c.v., 24 hr pretreatment), the delta-2 opioid receptor (naltrindole benzofuran, 25 pmol i.c.v.) and the kappa opioid receptor (nor-binaltorphimine, 10 mg/kg s.c.). The antinociceptive activity of SNF9007 was not a result of the activation of CCK receptors, as treatment with either CCK-A or CCK-B receptor antagonist was ineffective in blocking SNF9007 antinociception. Nor-binaltorphimine and naltrindole benzofuran were completely ineffective in blocking SNF9007 antinociception when administered alone or in combination. However, co-administration of delta-1 or delta-2 opioid receptor antagonists with the mu opioid receptor antagonist D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 resulted in a dramatic reduction in analgesic responses to SNF9007. Furthermore, the co-administration of mu+delta-1 + delta-2 opioid receptor antagonists resulted in an even greater inhibition of SNF9007 antinociception (> 10-fold shift). We conclude that SNF9007 acts simultaneously at brain delta-1, delta-2 and mu opioid receptors to induce antinociceptive effects in mice.

Amino Acid Sequence↗
PubMed1993

Neuromodulatory systems and memory storage: role of the amygdala.

This article reviews findings of research examining the interaction of peripheral adrenergic systems with cholinergic, opioid peptidergic and GABAergic systems in modulating memory storage. It is well established that retention is enhanced by posttraining systemic or intra-amygdala injections of adrenergic agonists, opiate antagonists and GABAergic antagonists. These influences appear to be mediated by activation of NE receptors within the amygdala, as intra-amygdala injections of beta-adrenergic antagonists block the memory-modulating effects of hormones and drugs affecting these systems. Furthermore, these influences also appear to involve, at a subsequent step, activation of a cholinergic system: atropine blocks the memory-enhancing effects of adrenergic agonists and opiate and GABAergic antagonists and oxotremorine attenuate the memory-impairing effects of opiate agonists and GABAergic agonists. These findings suggest that the amygdala integrates the memory-modulating effects of neuromodulatory systems activated by learning experiences.

Amygdala↗
PubMed1993

Treatment of childhood obesity in pediatric practice.

Evaluation of obese children and adolescents in the pediatric office or clinic should include baseline assessment of weight for height, and body fatness; should rule out endocrine and genetic causes of obesity; and should evaluate other cardiovascular risk factors. Treatment of obesity is most successful if realistic goals are set; if a safe rate of weight loss of one to two pounds per week can be achieved through a reduction of caloric intake that amounts to 500 calories less per day; if increased physical activity is stressed as much as diet; if parental support is strong; and if behavior therapy is provided during the course of treatment to help both child and parent achieve the diet, exercise, and behavior goals.

Adolescent↗
PubMed1993

Hormonal modulation of the cutaneous initiation of lordosis in infant and adult rats.

The purpose of these experiments is to compare the regional specificity (Experiment 1) and the hormonal modulation (Experiment 2) of the cutaneous initiation of lordosis in 4- to 6-day-old male and female rats (infants) and in 60- to 90-day-old female rats (adults). In Experiment 1, subjects were primed with 100 micrograms estradiol benzoate (EB) and 0.5 mg progesterone (P) and were denervated on the Waist (dermatomes L1-L3), Midriff (dermatomes T10-L3), Flanks (dermatomes L4-L6), or Sides (dermatomes T10-L6). In infants, there were no significant differences between males and females. Denervation of the Waist, Midriff, or Sides but not of the Flanks significantly decreased the percentage of subjects displaying lordosis, lordosis quotient (LQ), and mean lordosis duration; no significant differences were obtained among Waist-, Midriff, or Sides-denervated infants. In contrast, denervation of the Sides but not of the Waist significantly decreased LQ and mean lordosis intensity among adults. In Experiment 2, Waist-denervated infants and their surgical Controls were treated either with 100 micrograms EB and 0.5 mg P or with the oil vehicle; Waist-denervated adults and their surgical Controls received either 100 or 10 micrograms EB (no P). Regardless of hormone treatment, denervation of the Waist significantly decreased LQ and lordosis duration in infants and decreased LQ and lordosis intensity in adults. In infants, the only effect of priming with EB and P was to increase the percentage of pups showing lordosis and lordosis duration among the surgical Controls. In contrast, priming with 100 micrograms EB significantly increased the percentage of rats displaying lordosis, LQ, and lordosis intensity among Waist-denervated adults. These data suggest that cutaneous input from the Waist is important for eliciting lordosis in both infant and adult rats, and that the importance of this input is modulated by hormone priming in adult but not infant rats.

Animals↗
PubMed1993

A child health report card: 1992.

It is because of statistics like the ones included above in the Report Card that the health of our children has become a topic of great concern. These statistics, however, reflect only a small piece of a much larger problem, which includes child poverty, child neglect, child abuse, family disintegration, educational failure, violence, and crime. Indeed the biggest threats to child health have roots in the past and present core of our social and environmental conditions. Improving the health of our children will require innovative and comprehensive approaches that include health education, health services, and family support. The cost of our failure to fund preventive programs in the area of child and family health is significant and mounting. Prenatal care for a pregnant women for 9 months cost about $600; however, medical care for a premature baby for only one day may cost more than four times as much ($2,500). Similar comparisons for the cost of prevention versus treatment are listed in Table 8. It is clear that unless we as a nation place more emphasis on funding preventive medicine, the health of our children will continue to suffer, with grave consequences for the future of our country.

Adolescent↗
PubMed1993

Lyme disease and pregnancy outcome: a prospective study of two thousand prenatal patients.

OBJECTIVE: The purpose of the study was to determine if prenatal exposure to Lyme disease was associated with an increased risk of adverse pregnancy outcome. STUDY DESIGN: Approximately 2000 Westchester County, New York, women completed questionnaires and had sera tested for antibody to Borrelia burgdorferi at their first prenatal visit and at delivery. Fetal death, birth weight, length of gestation at delivery, and congenital malformations were examined in relation to maternal Lyme disease exposure before and during pregnancy. RESULTS: Maternal Lyme disease or an increased risk of exposure to Lyme disease was not associated with fetal death, decreased birth weight, or length of gestation at delivery. Tick bites or Lyme disease around the time of conception was not associated with congenital malformations. Tick bites within 3 years preceding conception were significantly associated with congenital malformations, but this could have reflected reporting differences between exposed and unexposed women. CONCLUSIONS: Maternal exposure to Lyme disease before conception or during pregnancy is not associated with fetal death, prematurity, or congenital malformations taken as a whole. We have not ruled out the possibility that exposure to Lyme disease as defined by maternal history increases the risk of specific malformations or has an effect if it is not treated. We have insufficient numbers of women who were seropositive at their first prenatal visit to determine if this subgroup of exposed women are at a moderately increased risk of having a child with a congenital abnormality. The low frequency of seroconversion at delivery in this endemic area suggests that preventive measures are being taken by obstetricians and patients.

Congenital Abnormalities↗
PubMed1993

Effects of vagotomy on Leu-enkephalin-induced changes in memory storage processes.

When given before or after training, Leu-enkephalin impairs later retention of learning. To replicate these findings, Experiment 1 determined if Leu-enkephalin impairs retention when administered after inhibitory avoidance training. Posttraining injection of 100.0 micrograms/kg of Leu-enkephalin impaired retention relative to saline controls or those receiving a lower dose of this peptide. Since Leu-enkephalin does not cross freely from the blood stream into the brain, this peptide may exert its influence on mnemonic processes by activating peripheral receptors that transmit neural messages to the brain via the vagus nerve. In Experiment 2, 100.0 micrograms/kg Leu-enkephalin impaired retention in unoperated and sham-operated animals although vagotomized animals did not differ significantly from these groups or saline controls. These results suggest that subdiaphragmatic vagotomy may not be sufficient to disrupt the mnemonic effects of Leu-enkephalin. Alternatively, the vagus nerve may be one pathway but not the only pathway by which the activation of peripheral systems may influence the memory storage process.

Animals↗
PubMed1993

Regulation of E-cadherin-mediated adhesion by muscarinic acetylcholine receptors in small cell lung carcinoma.

We present the first evidence that adhesion mediated by a member of the cadherin gene family can be regulated by a G protein-coupled receptor. We show that activating the M3 muscarinic acetylcholine receptor (mAChR) rapidly induces E-cadherin-mediated adhesion in a small cell lung carcinoma (SCLC) cell line. This response is inhibited by E-cadherin antibodies, and does not occur in another SCLC cell line which expresses functional mAChR but reduced levels of E-cadherin. Protein kinase C may be involved, since phorbol 12-myristate 13-acetate also induces E-cadherin-mediated aggregation. Immunofluorescence analyses indicate that mAChR activation does not grossly alter E-cadherin surface expression or localization at areas of cell-cell contact, suggesting mAChR activation may increase E-cadherin binding activity. Our findings suggest that G protein-coupled receptors may regulate processes involving cadherin-mediated adhesion, such as embryonic development, neurogenesis, and cancer metastasis.

Cadherins↗
PubMed1993

Background, conceptualization and design of a community-wide research program on adolescent alcohol use: Project Northland.

Project Northland is a community-wide research program funded by the National Institute on Alcoholism and Alcohol Abuse, for a 5-year period (1990-95). The aim of the study is to prevent or delay onset of alcohol use among young adolescents, as well as to reduce use among those who are already drinkers. Twenty communities were recruited in northeastern Minnesota, an area referred to as the Northland, Arrowhead or Iron Range region, and then were randomly assigned to either Education or Delayed Program conditions. The 10 Education school districts have agreed to participate in 3 years of intervention programs in schools, with parents and in the community-at-large. One group of young adolescents, the Class of 1998 (sixth grade students in the 1991-92 school year), form the study cohort. Surveys (1991-94) of the Class of 1998, their parents, community leaders and alcohol merchants are the primary components of the program's evaluation. Many conceptual and methodological questions emerged during the development of the research protocols for Project Northland over the past 2 years. These questions are the impetus for this article. Specifically, the focus on young adolescents and alcohol use was selected, as contrasted with older adolescents or with multiple problem behaviors. The project was designed using a community-wide model that addresses both supply and demand issues, rather than limited to a school-based model. Intervention strategies and evaluation methods were chosen that could address community-level as well as individual-level behavior change, which required the development and application of new technologies. The rationale for these decisions may be useful to others considering community-wide health promotion efforts.

Adolescent↗
PubMed1993

Effects of a saliva test pipeline procedure on adolescent self-reported alcohol use.

Self-reports on alcohol use collected via school-based questionnaires, telephone surveys, and household interviews are central measures in many studies in the alcohol field. The validity of such self-reports remains an issue. Use of biological pipeline procedures is one way in which the quality of self-reports might be improved. The current study tested the effectiveness of a saliva test pipeline procedure in increasing drinking disclosure rates among adolescents in the sixth and eighth grades. Two sixth-grade classes from each of 14 elementary schools (n = 828) and four eighth-grade classes from each of 8 middle schools (n = 754) were selected. Half of the classes in each school were assigned to the pipeline condition and half to the control condition. Each student in the pipeline condition was asked to provide a saliva sample via dental roll before completing a questionnaire that all students (pipeline and control) received. Pipeline students were told that "some of the saliva we collect today will be tested in a laboratory and will provide a biological measure of alcohol use." Sixth- and eighth-grade students exposed to the alcohol procedure reported 5 to 7% higher alcohol use prevalences than students in the control group. While the pattern of improved reporting under the pipeline condition held across four alcohol-use measures and two grade levels, the effect was statistically significant for only one measure. The pipeline procedures used here had small effects on adolescent self-reported alcohol use.

Adolescent↗
PubMed1993

Enteric GABA-containing nerves projecting to the guinea-pig inferior mesenteric ganglion modulate acetylcholine release.

1. The effect of GABA and GABA receptor-modulating drugs on release of [3H]acetylcholine was studied in the guinea-pig inferior mesenteric ganglion. 2. GABA caused a dose-dependent increase in [3H]acetylcholine release during stimulation of the lumbar colonic nerves. Muscimol (10 microM) and diazepam (5 microM) also increased [3H]acetylcholine release during stimulation of the lumbar colonic nerves whereas baclofen (10 microM) had no effect. 3. Bicuculline (20-100 microM) and picrotoxin (50 microM) alone reduced [3H]acetylcholine release during electrical stimulation of the lumbar colonic nerves whereas phaclofen (300 microM) had no effect. 4. Bicuculline (100 microM) significantly decreased whereas diazepam (5 microM) significantly increased distension-induced [3H]acetylcholine release. 5. Colonic distension significantly increased [3H]GABA release in the inferior mesenteric ganglion compared to basal periods when the colon was not distended. Distension-induced release of [3H]GABA resulted from active neuronal transmission from the colon to the inferior mesenteric ganglion, since perfusion of the inferior mesenteric ganglion with tetrodotoxin (1 microM) reduced basal release of [3H]GABA and abolished distension-evoked increases in the release of [3H]GABA. 6. In contrast to its excitatory effects on peripheral colonic afferent cholinergic nerves, exogenous GABA caused a dose-dependent decrease in [3H]acetylcholine release during electrical stimulation of the central lumbar splanchnic nerves. Baclofen (10 microM) also inhibited [3H]acetylcholine release whereas muscimol (10 microM) or diazepam (5 microM) had no effect. Phaclofen (300 microM) antagonized the inhibitory effects of exogenous GABA (10 microM) and of baclofen (10 microM). Bicuculline (100 microM), picrotoxin (50 microM) and phaclofen (300 microM) alone had no effect on [3H]acetylcholine release during splanchnic nerve stimulation. 7. Phaclofen (300 microM) increased [3H]acetylcholine release during simultaneous electrical stimulation of the lumbar colonic nerves and splanchnic nerves and when GABAA receptors were blocked by bicuculline (20 microM). 8. The data suggest that GABAA receptors facilitate release of acetylcholine from peripheral cholinergic mechanosensory nerves projecting from the colon to the inferior mesenteric ganglion and that GABAB receptors inhibit release of acetylcholine from central cholinergic nerves. Enteric GABA-containing nerves projecting to the inferior mesenteric ganglion are mechanosensory. Endogenous release of GABA may act on GABAA receptors to facilitate peripheral cholinergic mechanosensory transmission and/or on GABAB receptors to inhibit central cholinergic transmission.

Acetylcholine↗
PubMed1993

Effects of naloxone on estrogen-induced changes in hypothalamic gonadotropin-releasing hormone pulse generator activity in the rhesus monkey.

In the ovariectomized rhesus monkey, estradiol (E2) markedly reduces the frequency of the GnRH pulse generator as monitored by LH pulse frequency and the concurrent changes in hypothalamic electrical activity, an action mimicked by morphine. In addition, the duration of the increments in multiunit electrical activity (MUA volleys) that precede each LH pulse is decreased by estrogen administration, an action also shared by morphine. The role of endogenous opioids in these actions of E2 was investigated in 8 ovariectomized animals restrained in primate chairs. They were fitted with indwelling cardiac catheters and with bilateral arrays of recording electrodes chronically implanted in the mediobasal hypothalamus. Physiological serum E2 levels achieved by subcutaneous implantation of E2-containing Silastic capsules increased MUA volley interval from 50.8 +/- (SEM) 1.6 min in the control period to 81.1 +/- 6.2 min following E2. Mean MUA volley duration decreased from 21.9 +/- 1.0 to 13.0 +/- 0.7 min. The placement of empty Silastic capsules had no effect on MUA volley duration or interval. Naloxone administration (2.5 mg bolus followed by a 1 mg/h infusion lasting 4-8 h) completely (n = 4) or partially (n = 2) blocked the effects of E2 on MUA volley interval in 6 of the 8 monkeys, and was without effect in the remainder. In contrast, however, naloxone had little or no effect on the action of E2 on MUA volley duration, (13.0 +/- 0.7 vs. 14.0 +/- 0.9 min). These findings suggest that the inhibitory action of E2 on GnRH pulse generator frequency, like that of all other gonadal steroids studied to date, may be mediated by endogenous opioids.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Ovarian control of gonadotropin hormone-releasing hormone pulse generator activity in the rhesus monkey: duration of the associated hypothalamic signal.

The activity of the GnRH pulse generator in the rhesus monkey is associated with abrupt increases in multiunit electrical activity (MUA) volleys recorded from the mediobasal hypothalamus that precede each pulse of LH in the peripheral circulation. In long-term ovariectomized animals the duration of these MUA volleys is 10-25 min and consists of a brief initial 'overshoot' followed by a plateau phase that ends in a rapid decline to baseline activity. In intact monkeys, however, the MUA volley lasts only 1-3 min, a duration equivalent to the overshoot in ovariectomized animals. In addition, the maximal frequency of neuronal activity during each MUA volley is reduced in normal animals when compared to castrates. As shown in earlier studies, estradiol given to ovariectomized monkeys causes a reduction in the duration of MUA volleys to that characteristic of intact animals within 3-5 h. In contrast to this acute effect of estradiol, the increase in MUA volley duration following ovariectomy is a gradual phenomenon, 4-6 weeks being required to achieve the MUA volley duration observed in long-term ovariectomized monkeys. A similar slow time course was observed for the increase in maximal neuronal frequency during each MUA volley. This protracted effect of ovariectomy on MUA volley duration and firing rate may be the consequence of hypothalamic remodelling but this consideration must be tempered by the observation that estradiol reverses these phenomena within hours.

Animals↗
PubMed1993

Success in baccalaureate nursing programs: a matter of accommodation?

This article explores student learning styles as an important variable in four-year baccalaureate nursing programs. Student learning styles were assessed by Kolb's Learning Style Inventory-1985 (LSI-1985), which identifies the accommodator, diverger, assimilator, and converger learning styles. The authors examined the relationship between learning style and academic performance as measured by grade-point ratio (GPR) and studied behaviors and attitudes as measured by Brown and Holtzman's (1964) Survey of Study Habits and Attitudes. Analysis indicated that this sample (N = 100) included mainly assimilators and divergers, making reflective observation the most common mode of learning. Compared to the accommodator/converger group, the assimilator/diverger group earned a significantly higher GPR, significantly better scores on the study habits variable of Work Methods (WM), and moderately better scores on the study attitude variable of Educational Acceptance (EA). Accommodators were identified as the most at-risk learning style group, and specific interventions were suggested to assist accommodators in adapting to the academic rigors of a nursing curriculum.

Achievement↗