Biomedical subjects

J C Anthony

Publications and source records attributed to J C Anthony.

At least 37 records · Page 2Linked to original sources

PubMed2001

Intrauterine growth of full-term infants: impact of prenatal cocaine exposure.

OBJECTIVE: The objectives of this study were to estimate the effect of prenatal cocaine exposure on fetal growth and gestational age after controlling for exposure to alcohol, tobacco, and marijuana and other covariates; to evaluate whether prenatal cocaine exposure has a disproportionate adverse effect on head circumference compared with overall somatic growth; and to assess whether the effect of prenatal cocaine exposure on fetal growth is mediated by cocaine's suspected effect on gestational age. METHODS: The study population includes 476 neonates participating in the Miami Prenatal Cocaine Study, a longitudinal follow-up of in utero cocaine exposure. The sample, restricted to full-term neonates born to African-American inner-city mothers, included 253 infants exposed prenatally to cocaine (with or without alcohol, tobacco, or marijuana exposure) and 223 non-cocaine-exposed infants, of whom 147 were drug-free and 76 were exposed to varying combinations of alcohol, tobacco, or marijuana. RESULTS: Evidence based on structural equations and multiple regression models supports a hypothesis of cocaine-associated fetal growth deficits (0.63 standard deviation) and an independent mild effect on gestational age (0.33 standard deviation). There was no evidence of a disproportionate adverse effect on birth head circumference once the impact on overall growth was estimated. There was evidence that some but not all of the cocaine effect on fetal growth was direct and some was indirect, acting via an intermediate influence of cocaine on gestational age. CONCLUSIONS: Cocaine-associated growth deficits, symmetrical and partially mediated by gestational age, were observed in this sample of inner-city African-American full-term infants prospectively enrolled at birth. Long-term implications will be the subject of future reports from this longitudinal investigation.

Adult↗

PubMed2001

Tobacco use among high school students in Buenos Aires, Argentina.

OBJECTIVES: This study assessed the prevalence and correlates of tobacco use among high school students in Buenos Aires, Argentina. METHODS: Anonymous, self-administered questionnaires were given to 3909 8th and 11th graders in a stratified random sample of 49 public and private schools. The instrument included items from American surveys, translated and validated among Argentinean teens. Multiple logistic regression analysis was used to estimate possible effects on smoking behavior of environment, students' personal characteristics, and their knowledge, beliefs, and attitudes regarding smoking. RESULTS: Of 8th and 11th graders, 20% and 43%, respectively, were classified as current smokers. Overall, 29% of males and 32% of females were current smokers. Students attending public schools were more likely to smoke than those in private schools (P < .05). Current smoking was associated with having a best friend who smokes, reporting that more than 50% of friends of the same sex smoke, having positive attitudes and beliefs toward smoking, and having a positive intention to smoke within the next year (all P < .001). CONCLUSIONS: Over 20% of the 8th graders in our sample were current smokers; prevention efforts must therefore start early.

Adolescent↗

PubMed2000

Clusters of drug involvement in Panama: results from Panama's 1996 National Youth Survey.

This report is based on the first epidemiological investigation of clustering of tobacco, alcohol, inhalant, and other drug involvement within individual schools using data from Panama's 1996 National Youth Survey on Alcohol and Drug Use. Clustering was estimated with the Alternating Logistic Regression method. Adjusted estimates of pair-wise cross-product ratios (PWCPR), a measure of clustering, show modest clustering (i.e. PWCPR>1.0) at the school level for tobacco smoking (PWCPR=1.41; 95% confidence interval, CI=1.22-1.64), alcohol consumption (PWCPR=1.33; 95% CI=1.22-1.45), use of inhalants, (PWCPR=1.35; 95% CI=1.07-1.69), and other drug use (PWCPR=1.38; 95% CI=1.14-1.68). These findings provide preliminary evidence that the odds of drug use among school-attending youths increase when another youth in the same school uses drugs, and suggest a new line of research on within-school diffusion that should include the identification of school-level factors that contribute to student drug use.

Adolescent↗

PubMed2000

Reduced prevalence of AD in users of NSAIDs and H2 receptor antagonists: the Cache County study.

OBJECTIVE: To test the hypothesis that nonsteroidal anti-inflammatory drugs (NSAIDs) and histamine H2 receptor antagonists (H2RAs) are associated with a decreased risk of AD in late life. BACKGROUND: Sustained use of non-aspirin NSAIDs has been repeatedly associated with a reduced occurrence of AD. Similar effects with aspirin have been weaker. One prior study showed a strong association between use of H2RAs and reduced AD prevalence. METHODS: In a population study of AD in Cache County, UT, we used a sequenced plan of sampling and case ascertainment to identify 201 cases of AD and 4425 participants with no indication of cognitive impairment. Independently, an interview and medicine chest inventory assessed use of several medicines including aspirin, non-aspirin NSAIDs, H2RAs, and three classes of "control" drugs not thought to be associated with AD. Follow-up questioning probed possible indications for use of these drugs. RESULTS: Compared with cognitively intact individuals, the AD cases had significantly less reported current use of NSAIDs, aspirin, and H2RAs. Stronger associations appeared when subjects reported use of both NSAIDs and aspirin (no H2RAs), two different NSAIDs (no H2RAs), or two different H2RAs (with neither aspirin nor NSAIDs). There was little or no such association with use of the control medicines. Adjustment for usage indication did not influence these findings, and there was no appreciable variation with number of APOE epsilon4 alleles. CONCLUSIONS: As predicted, use of NSAIDs and aspirin were specifically associated with reduced occurrence of AD. Notably, a previous observation of an inverse association of AD and use of H2RAs was also affirmed. Definitive evidence for a preventive action of these agents will require randomized prevention trials.

Aged↗

PubMed2000

The suspected association between methamphetamine ('ice') smoking and frequent episodes of alcohol intoxication: data from the 1993 National Household Survey on Drug Abuse.

This study estimates the strength of association between frequent episodes of alcohol intoxication and recent smoking of methamphetamine ('ice'). Drawn from the 1993 National Household Survey on Drug Abuse, a total of 101 ice smokers were matched on neighborhood of residence to 816 non-smokers. Based upon conditional logistic regression analyses, persons with daily episodes of alcohol intoxication were an estimated five times more likely to have smoked ice, as compared with non-drinkers or drinkers with little or no history of alcohol intoxication. This estimate includes statistical adjustment for potential confounders (e.g. age, sex) and was statistically significant (P=0.01). The association between frequent alcohol intoxication and 'ice smoking' offers an intriguing lead for a broad range of new research.

Adult↗

PubMed2000

Perceived risk of cocaine use and experience with cocaine: do they cluster within US neighborhoods and cities?

This study investigates whether experience with cocaine and the perception of risk associated with cocaine use might tend to cluster within neighborhoods and cities in the US. Population-based data from six years of the National Household Surveys on Drug Abuse public use files are employed. The alternating logistic regressions model is used to quantify the extent of geographic concentration. Perceptions of the harm associated with cocaine use and actual experience with cocaine tend to cluster within neighborhoods; once within-neighborhood concentration is taken into account, there is little evidence of residual concentration within cities.

Adolescent↗

PubMed2000

The estimated rate of depressed mood in US adults: recent evidence for a peak in later life.

OBJECTIVE: The main aim of this study is to add new evidence on the descriptive epidemiology of depressed mood, and to investigate suspected determinants for depressed mood in adulthood. METHODS: The data are from a continuing survey of a nationally representative sample of adult household residents in the United States, conducted in 1995 and 1996, totaling 26,883 respondents. Multiple logistic regression procedures yielded estimated associations. RESULTS: We found that an estimated 1.9% of adult females and 1.0% of adult males experience a spell of sustained depressed mood during a span of approximately 2 weeks duration (i.e. point prevalence). For most of these cases, this is not the first spell. Among women, the smoothed curve for the prevalence estimates shows a peak in the youngest age stratum and decreases across age strata before 60 years, and has a slight secondary peak thereafter. In contrast, for males, the prevalence estimates of depression show no peak in the older age strata. Evidence from logistic regression analyses supports the inference of this later life peak in frequency of depressed mood among women. These new findings add to a growing body of epidemiological evidence on age and depression, and provoke new questions about the possibly etiological relationships involving social structural characteristics of local neighborhoods in combination with individual-level risk factors that have received primary attention in recent psychiatric epidemiology. CONCLUSIONS: These findings point to the need for further etiological research, including studies of relationships between social structural characteristics of local neighborhoods and the occurrence of spells of depressed mood, as well as clinical implications for depression mood in late life.

Adolescent↗

PubMed2000

Elucidating the contributions of processing speed, executive ability, and frontal lobe volume to normal age-related differences in fluid intelligence.

One theory of normal cognitive aging asserts that decreases in simple processing speed mediate the age-related decline of fluid intelligence. Another possibility is that age-related atrophic changes in frontal brain structures undermine the functioning of executive abilities, thereby producing the same decline. In this study, we used principal components analysis to derive a measure of fluid-spatial intelligence in 197 normal adults between 20 and 92 years of age. Measures of perceptual comparison speed, working memory, and executive ability, as well as regional brain volumes based on high resolution magnetic resonance imaging were obtained from a subsample of 112 participants. We then conducted a series of hierarchical multiple regression analyses to test whether (1) the processing speed theory, (2) frontal-executive theory, or (3) some combination of these best accounted for age-related variation in fluid intelligence. The results showed that perceptual comparison speed, executive ability, and frontal lobe volume each made significant contributions to a regression equation that explained 57% of the variance in fluid intelligence. These findings suggest that both the processing speed and frontal-executive theory of cognitive aging are partially correct and complement one another.

Adult↗

PubMed2000

Drug use among welfare recipients in the United States.

This study examined the prevalence of drug use in a nationally representative sample of 1989 recipients and 6840 nonrecipients of four welfare programs. Data from the 1995 National Household Survey on Drug Abuse (NHSDA) were analyzed using the conditional form of multiple logistic regression with matching of respondents on neighborhood of residence. Weighted proportions and variances accounting for the complex sample design of the NHSDA survey were estimated using the Taylor series linearization method. The results indicate that drug use is 50% more common in households with welfare recipients than in nonwelfare households. Programs making welfare eligibility contingent on the recipient working toward a drug-free lifestyle are worth examining, although a vigilant eye must be kept on the potential unintended consequences.

Eligibility Determination↗

PubMed2000

Leucine stimulates translation initiation in skeletal muscle of postabsorptive rats via a rapamycin-sensitive pathway.

The objectives of the present study were twofold: 1) to determine whether leucine is unique among the branched-chain amino acids (BCAA) in its ability to stimulate protein synthesis in skeletal muscle of food-deprived rats; and 2) to investigate whether changes in muscle protein synthesis after leucine administration involve a signaling pathway that includes the protein kinase mammalian target of rapamycin (mTOR). In the first set of experiments, food-deprived (18 h) male rats (200 g) were orally administered saline or 270 mg valine, isoleucine or leucine. In the second set of experiments, food-deprived rats were injected intravenously with rapamycin (0.75 mg/kg), a specific inhibitor of mTOR, before leucine administration. Only leucine stimulated protein synthesis in skeletal muscle above saline-treated controls (P: < 0.05). Furthermore, leucine was most effective among the BCAA at enhancing phosphorylation of eukaryotic initiation factor (eIF), 4E binding protein 1 (4E-BP1) and the 70-kDa ribosomal protein S6 kinase (S6K1). Leucine-dependent hyperphosphorylation of 4E-BP1 increased the availability of eIF4E to form the active eIF4G.eIF4E complex. To a lesser extent, isoleucine also enhanced phosphorylation of 4E-BP1 and S6K1. Rapamycin inhibited protein synthesis in both leucine-treated and food-deprived rats. Additionally, rapamycin prevented the stimulatory effects of leucine on eIF4E availability for binding eIF4G and inhibited leucine-dependent phosphorylation of S6K1. The data demonstrate that leucine is unique among the BCAA in its ability to stimulate protein synthesis in muscle of food-deprived rats. We show for the first time that leucine-dependent stimulation of translation initiation in vivo occurs via a rapamycin-sensitive pathway.

Animals↗

PubMed2000

Orally administered leucine stimulates protein synthesis in skeletal muscle of postabsorptive rats in association with increased eIF4F formation.

We investigated the protein synthetic response of skeletal muscle to an orally administered dose of leucine given alone or in combination with carbohydrate. Male rats were freely fed (F) or food deprived for 18 h; food-deprived rats were then administered saline (S), carbohydrate (CHO), leucine (L) or a combination of carbohydrate plus leucine (CL). CHO and CL meals were isocaloric and provided 15% of daily energy requirements. L and CL meals each delivered 270 mg leucine. Muscle protein synthesis in S was 65% of F (P<0.01) 1 h after meal administration. Concomitant with lower rates of protein synthesis, phosphorylation of the translational repressor, eukaryotic initiation factor (eIF)4E-binding protein 1 (4E-BP1), was less in S, leading to greater association of 4E-BP1.eIF4E, and reduced formation of the active eIF4G.eIF4E complex compared with F (P<0.01). Oral administration of leucine (L or CL), but not CHO, restored protein synthesis equal to that in F and resulted in 4E-BP1 phosphorylation that was threefold greater than that of S (P<0.01). Consequently, formation of 4E-BP1.eIF4E was inhibited and eIF4G.eIF4E was not different from F. The amount of eIF4E in the phosphorylated form was greater in S and CHO (P<0.01) than in all other groups. In contrast, no differences in the phosphorylation state of eIF2alpha or the activity of eIF2B were noted among treatment groups. Serum insulin was elevated 2.6- and 3.7-fold in CHO and CL, respectively, but was not different in L, compared with S (P<0.05). These results suggest that leucine stimulates protein synthesis in skeletal muscle by enhancing eIF4F formation independently of increases in serum insulin.

Administration, Oral↗

PubMed2000

4E-BP1 and S6K1: translational integration sites for nutritional and hormonal information in muscle.

Maintenance of cellular protein stores in skeletal muscle depends on a tightly regulated synthesis-degradation equilibrium that is conditionally modulated under an extensive range of physiological and pathophysiological circumstances. Recent studies have established the initiation phase of mRNA translation as a pivotal site of regulation for global rates of protein synthesis, as well as a site through which the synthesis of specific proteins is controlled. The protein synthetic pathway is exquisitely sensitive to the availability of hormones and nutrients and employs a comprehensive integrative strategy to interpret the information provided by hormonal and nutritional cues. The translational repressor, eukaryotic initiation factor 4E binding protein 1 (4E-BP1), and the 70-kDa ribosomal protein S6 kinase (S6K1) have emerged as important components of this strategy, and together they coordinate the behavior of both eukaryotic initiation factors and the ribosome. This review discusses the role of 4E-BP1 and S6K1 in translational control and outlines the mechanisms through which hormones and nutrients effect changes in mRNA translation through the influence of these translational effectors.

Amino Acids↗

PubMed2000

Glucocorticoids oppose translational control by leucine in skeletal muscle.

Glucocorticoids comprise an important class of hormonal mediators of fuel and protein homeostasis in normal and pathological scenarios. In skeletal muscle, exposure to glucocorticoids is characterized by a reduction in protein synthetic rate coincident with hampered translation initiation. However, it is unclear whether this involves attenuation of anabolic stimuli or is simply due to inhibition of the basally activated translational apparatus. Therefore, this inquiry was designed to determine whether leucine, administered orally, could rescue the translational inhibition induced by glucocorticoids. Dexamethasone, injected intraperitoneally, acutely diminished protein synthetic rates to 80% of control values in skeletal muscle from rat hindlimb. The eukaryotic initiation factor (eIF)4 regulatory element was simultaneously and negatively impacted via sequestration of eIF4E by the hypophosphorylated form of the translational suppressor, eIF4E binding protein 1 (4E-BP1). The 70-kDa ribosomal protein S6 kinase (S6K1) was also dephosphorylated, notably at T389, in response to glucocorticoids. Leucine, administered orally, effectively restored each aforementioned translational parameter to control levels. Inasmuch as leucine's potency in modulation of the translational machinery, and indeed of protein turnover in general, is widely appreciated, this amino acid may prove useful in normalizing the impairment of mRNA translation associated with various muscle-wasting pathologies, such as glucocorticoid excess.

Animals↗

PubMed2000

School dropout and injecting drug use in a national sample of white non-Hispanic American adults.

In this study we sought to extend our previous finding of an association between school dropout and injecting drug use (IDU) among African Americans by testing the association in a sample of White non-Hispanic Americans. A nationally representative sample of White non-Hispanic Americans age eighteen years and older was drawn from public use data files of the 1995-1996 National Household Surveys on Drug Abuse (NHSDA). Adults with a self-report history of IDU were identified, and were matched to non-IDU adults in the same neighborhoods of residence. Conditional logistic regression was used to estimate the association between dropping out of high school and the occurrence of IDU. White non-Hispanic American high school dropouts were more likely than high school graduates to have injected a drug at least once. The findings of this research on non-Hispanic Whites are generally consistent with our earlier evidence on the association between educational status and a history of IDU among African-American adults. School dropout prevention programs may merit attention in an overall strategy of preventing injecting drug use and HIV/AIDS.

Adult↗

PubMed2000

"Alcohol dependence" and death: survival analysis of the Baltimore ECA sample from 1981 to 1995.

OBJECTIVE: Evidence is provided about the association between "alcohol-use disorders" and the 14-year risk of death in a community sample. Most prior descriptions of this association come from treatment samples. METHOD: 3,481 adult household residents were recruited into the NIMB Baltimore Epidemiologic Catchment Area survey and interviewed in 1981. The Diagnostic Interview Schedule (DIS) was employed to assess alcohol drinking and other drug-taking behaviors, and to determine fulfillment of DSM-III criteria for "alcohol abuse" and/or "dependence" diagnoses. Participants were followed-up in 1993-1996, by which time 24% of the sample had died. Median age of death was estimated for persons with and without alcohol disorders, and for "heavy" and "nonheavy" drinkers. Cox proportional hazards models adjusted for the influence of age, sex, race, "drug-use disorders," and tobacco smoking. RESULTS: "Alcohol abuse" and/or "dependence" was associated with a higher risk of death and a younger median age of death (adjusted relative risk = 1.3, p = .016). "Heavy" alcohol consumption was also associated with a significantly elevated risk of death. The DIS diagnosis of "alcohol use disorder" helped predict mortality over and above a prediction based solely upon "heavy drinking" (p < .01). CONCLUSIONS: These findings indicate that the observed increased risk of death associated with "alcohol dependence" is not limited to cases severe enough to have been treated but is also present among cases in the household population.

Adolescent↗

PubMed2000

"Drug dependence" and death: survival analysis of the Baltimore ECA sample from 1981 to 1995.

AIMS: Illicit drug use and dependence often are associated with premature death, but available evidence comes mainly from clinical samples. The present paper examines drug-related mortality experience over 14 years in a United States community sample. PARTICIPANTS: Following probability sampling, 3,481 adult community household residents were recruited for the 1981 NIMH Baltimore Epidemiologic Catchment Area survey. Follow-up occurred in 1993-1996. METHODS: Survival analyses were used to estimate median age at death and relative risk of dying in relation to drug use and dependence as assessed in 1981 using the Diagnostic Interview Schedule (DIS). FINDINGS: Cases with DIS "drug dependence" were more likely to have died and to have a younger median age at death (p < .05), with and without statistical adjustment for confounding variables. Higher levels of drug involvement also were associated with increased age-adjusted mortality. CONCLUSIONS: The evidence favors the hypothesis that DIS-elicited "drug dependence," as well as subthreshold drug use, help to account for premature death in this community sample.

Adolescent↗

PubMed2000

Educational level and risk for alcohol abuse and dependence: differences by race-ethnicity.

OBJECTIVE: Using prospective data, we extend and strengthen prior evidence on the relationship of educational level and the risk of alcohol abuse and dependence among adults. Hypothesizing that risk of alcohol disorders would be greater among individuals who dropped out of high school without getting a diploma, and among those who entered college but then failed to get a degree, relative to those with a college or higher degree, we examined these relationships by race-ethnicity. METHODS: Data are from the total of 18,571 adult participants selected for the Epidemiologic Catchment Area (ECA) program by probability sampling of households and census tracts between 1980 and 1984. To assess occurrence of psychiatric conditions over time, staff administered the Diagnostic Interview Schedule soon after sampling and again at followup approximately one year later. The final sample for this report was stratified: African Americans (N = 2856) and whites (N = 7889). RESULTS: In multiple logistic regression analyses, we found that dropping out of high school was associated with elevated risk for alcohol disorders, relative to those with an Associate of Arts degree or higher, among both African Americans (estimated relative risk [RR] = 4.0, 95% confidence interval [CI], 1.1-14.3, P = .03), and whites (RR = 4.7, 95% CI, 2.2-10.0, P = .0001). In contrast, entering college but failing to get a degree was associated with a significantly increased risk only for whites; however, African Americans were less numerous in the sample, causing attenuation of power. In order to assess whether this relationship was confounded by macrosocial factors of the neighborhood environment, cases were matched to non-cases by age and census tract, and initial conditional logistic regression analyses also were completed. CONCLUSIONS: If confirmed in other investigations, these findings may help to identify groups that are at higher risk for developing alcohol abuse and alcohol dependence in adulthood, and may aid in the development of prevention or early intervention programs.

Adolescent↗

PubMed2000

Epidemiologic analysis of alcohol and tobacco use.

Epidemiologists have conducted nationwide surveys, such as the National Household Survey on Drug Abuse (NHSDA) and the National Comorbidity Survey (NCS), to estimate the prevalence of either the individual or the concurrent consumption of and dependence on alcohol and tobacco. These estimates indicated that for both alcohol and tobacco, use was already relatively high among the youngest respondents, peaked among young adults, and declined in older age groups. A similar pattern existed for concurrent alcohol and tobacco use. Moreover, these estimates showed only moderate gender differences. With respect to dependence, the age-related prevalence patterns differed somewhat for alcohol and tobacco, with the prevalence of tobacco dependence relatively lower among the youngest respondents compared with the prevalence of alcohol dependence. The age-related pattern for concurrent alcohol and tobacco dependence was similar to that found for tobacco dependence.

Age Factors↗