Biomedical subjects

Lisa Greenwell

Publications and source records attributed to Lisa Greenwell.

11 recordsLinked to original sources

PubMed2006

Substance use pathways to methamphetamine use among treated users.

Considerable research has focused on patterns of substance use initiation among adolescents and for users of selected drugs; however, few data are available for methamphetamine (MA) users. This study describes substance initiation patterns for 352 MA users and assesses predictors of age of MA initiation and its sequencing. Subjects were randomly selected from treatment admissions in a large California county and interviewed using an extensive natural history protocol. Average age of MA initiation was 19 years. Nearly all (95%) had used alcohol, marijuana, and tobacco (average initiation age 13); inhalants, hallucinogens, and crack were also commonly used earlier in the drug sequence than MA. Earlier age of MA initiation was related to race/ethnicity (being non-African-American), younger age of first use of any substance, more types of early criminal behavior, and initiating MA use for sensation-seeking reasons. Following initiation of alcohol, marijuana, and/or tobacco, 27% initiated MA before other illicit drugs, 18% initiated another illicit drug before MA, and 56% initiated two or more other illicit drugs before MA. Later MA order in the initiation sequence was related to ethnicity (being African-American) and initiating MA to substitute for another drug. Results may support targeted prevention efforts and development of more effective interventions.

Adolescent↗

PubMed2006

Physical health of mothers with HIV/AIDS and the mental health of their children.

A longitudinal study was conducted on the psychological well-being of 81 young children (mean age = 8.8 years) living with mothers with AIDS or HIV-infected mothers with symptomatic disease. The relationship between mothers' physical health and children's psychological well-being was investigated. The children were assessed at seven time points over approximately 6 years. Individual growth models were estimated for children's depression, anxiety, and aggressiveness in relation to: mothers' viral load (medical records) and physical functioning, number of HIV-related physical symptoms, and medical visits due to illness (self-report). Results showed significant linear declines in children's depression, anxiety, and aggressiveness over time. Lower levels of physical functioning and more physical symptoms among mothers were associated with higher levels of children's depression, anxiety, and aggressiveness at baseline. Lower levels of physical functioning and more physical symptoms among mothers were associated with initially high but more rapidly decreasing levels of depression among children. However, mothers who began the study in better health appear to have changed in health more quickly than mothers who began the study in poorer health. Thus, stability in mothers' health appears to be associated with a more rapid improvement in children's mental health over time. Our findings suggest that the measures representing observable levels of, and changes in, mothers' health that are most likely to be directly experienced by themselves and their children are the measures that are most predictive of changes in children's mental health over time.

Acquired Immunodeficiency Syndrome↗

PubMed2006

Contingency management for treatment of substance use disorders: a meta-analysis.

AIMS: To examine the effectiveness of contingency management (CM) techniques in treating substance use disorders (i.e. illicit drugs, alcohol, tobacco). DESIGN: Meta-analysis was used to determine the average effect size and potential moderators in 47 comparisons of the effectiveness of CM from studies based on a treatment-control group design and published between 1970 and 2002. FINDINGS: The mean effect size (ES) of CM was positive, with a magnitude of d = 0.42 using a fixed effects model. The magnitude of the ES declined over time, following treatment. CM was more effective in treating opiate use (d = 0.65) and cocaine use (d = 0.66), compared with tobacco (d = 0.31) or multiple drugs (d = 0.42). Larger effect sizes were associated with higher researcher involvement, earlier studies and shorter treatment duration. CONCLUSIONS: Study findings suggest that CM is among the more effective approaches to promoting abstinence during the treatment of substance use disorders. CM improves the ability of clients to remain abstinent, thereby allowing them to take fuller advantage of other clinical treatment components.

Behavior Therapy↗

PubMed2005

Functional analyses of oxygenases in jadomycin biosynthesis and identification of JadH as a bifunctional oxygenase/dehydrase.

A novel angucycline metabolite, 2,3-dehydro-UWM6, was identified in a jadH mutant of Streptomyces venezuelae ISP5230. Both UWM6 and 2,3-dehydro-UWM6 could be converted to jadomycin A or B by a ketosynthase alpha (jadA) mutant of S. venezuelae. These angucycline intermediates were also converted to jadomycin A by transformant of the heterologous host Streptomyces lividans expressing the jadFGH oxygenases in vivo and by its cell-free extracts in vitro; thus the three gene products JadFGH are implicated in catalysis of the post-polyketide synthase biosynthetic reactions converting UWM6 to jadomycin aglycone. Genetic and biochemical analyses indicate that JadH possesses dehydrase activity, not previously associated with polyketide-modifying oxygenase. Since the formation of aromatic polyketides often requires multiple dehydration steps, bifunctionality of oxygenases modifying aromatic polyketides may be a general phenomenon.

Amino Acid Sequence↗

PubMed2005

Methamphetamine treatment: trends and predictors of retention and completion in a large state treatment system (1992-2002).

This report describes trends in treatment admissions for methamphetamine/amphetamine (MA) abuse from 1992 to 2002 in California and assesses predictors of treatment retention and completion. Results show such admissions increasing fivefold and representing a growing proportion of overall treatment admissions. Patients admitted for MA abuse were increasingly diverse in race/ethnicity, older in age, and more frequently under legal supervision status over time. There was a decrease in injection drug use. Several user characteristics played consistent roles as risk factors for noncompletion and shorter treatment retention for both residential and outpatient admissions: having lower than a high school education, being younger at treatment admission, having a disability, having greater severity of MA use, and using injection drugs. Consistently, those with legal supervision status at admission had higher completion rates and longer retention than those reporting no legal status. Overall, findings suggested that clients with greater socioeconomic disadvantage and more severe problems may require greater efforts (e.g., services) to be retained in treatment.

Adult↗

PubMed2005

Associations among childhood trauma, adolescent problem behaviors, and adverse adult outcomes in substance-abusing women offenders.

This article explores relationships among exposure to childhood abuse and traumatic events, adolescent conduct problems and substance abuse, and adult psychological distress and criminal behaviors in a sample of substance-abusing women offenders (N=440). Latent variable structural equation models revealed direct relationships between several childhood traumatic events and greater adolescent conduct problems and substance abuse. Conduct problems predicted more adult criminal behavior, and adolescent substance abuse predicted higher levels of current psychological distress. There were direct relationships between several types of traumatic events and current psychological distress and between traumatic events and specific criminal behaviors. Ethnic differences were also found, suggesting different pathways to criminal behavior. The findings underscore the need to provide trauma-related services for substance-abusing women offenders.

Adolescent↗

PubMed2004

The dynamic structure of jadomycin B and the amino acid incorporation step of its biosynthesis.

Jadomycin B, an antifungal antibiotic with a unique 8H-benz[b]oxazolo[3,2-f]phenanthridine pentacyclic skeleton produced by the bacterium Streptomyces venezuelae ISP 5230, exists in a dynamic equilibrium of two diastereomers differing in the configuration of C-3a. Several novel jadomycins with various amino acid-derived 1-side chains could be generated, by replacing isoleucine in the production medium of S. venezuelae with other amino acids. These two findings led to the conclusion that a nonenzymatic reaction with the amino acid followed by a likewise nonenzymatic cyclization cascade are crucial for its late biosynthesis.

Amino Acids↗

PubMed2004

Engineering biosynthetic pathways for deoxysugars: branched-chain sugar pathways and derivatives from the antitumor tetracenomycin.

Sugar biosynthesis cassette genes have been used to construct plasmids directing the biosynthesis of branched-chain deoxysugars: pFL942 (NDP-L-mycarose), pFL947 (NDP-4-deacetyl-L-chromose B), and pFL946/pFL954 (NDP-2,3,4-tridemethyl-L-nogalose). Expression of pFL942 and pFL947 in S. lividans 16F4, which harbors genes for elloramycinone biosynthesis and the flexible ElmGT glycosyltransferase of the elloramycin biosynthetic pathway, led to the formation of two compounds: 8-alpha-L-mycarosyl-elloramycinone and 8-demethyl-8-(4-deacetyl)-alpha-L-chromosyl-tetracenomycin C, respectively. Expression of pFL946 or pFL954 failed to produce detectable amounts of a novel glycosylated tetracenomycin derivative. Formation of these two compounds represents examples of the sugar cosubstrate flexibility of the ElmGT glycosyltransferase. The use of these cassette plasmids also provided insights into the substrate flexibility of deoxysugar biosynthesis enzymes as the C-methyltransferases EryBIII and MtmC, the epimerases OleL and EryBVII, and the 4-ketoreductases EryBIV and OleU.

Antineoplastic Agents↗

PubMed2003

Self-reported health status among treated methamphetamine users.

Very little research has examined how drug abuse is related to general health status over the long term among both young and middle-aged adults. In this article, we investigate how self-reported health status is related to prolonged methamphetamine (MA) use in a diverse sample of MA users from ages 18 to 52 who have been treated for drug abuse in Los Angeles County. Using retrospective data, we investigate how prolonged MA use within younger and older age groups is related to two self-reported measures of current health status: the presence of a health condition that began after starting illegal drug use, and overall health. We control for the effects of drug use history, social and demographic factors, and other early experiences (e.g., early sexual abuse) that might be obstacles to achieving good health later in life. We find that having a current health condition is predicted by greater age and by more prolonged MA use, especially among younger people. Early sexual abuse predicts both measures of poor health. Current health status is predicted by several measures of drug use history and early experiences, but by fewer social and demographic factors. The results suggest that reduction of MA use among younger people is important in promoting their later health and that MA treatment services could be improved by a greater understanding of how early experiences influence later health.

Adolescent↗

PubMed2002

Factors associated with antiretroviral adherence among HIV-infected women with children.

HIV symptomatic or AIDS diagnosed women who had a young well child were recruited for a study investigating their adherence to antiretrovirals (N = 46). Very poor rates of adherence were found, ranging from 43% (pill count assessment) to 56% (self-report of 3-day adherence to dose). Several factors were associated with nonadherence, including alcohol use, perceived stress, having a partner and age of youngest child, poor self-efficacy to stay with treatment, and poor outcome expectancies regarding the benefits of following the treatment regimen. Interventions to assist these women in improving adherence are urgently needed.

Adult↗

PubMedDate not supplied

Substance abuse treatment for women: changes in the settings where women received treatment and types of services provided, 1987-1998.

Changes in social policies during the last 2 decades have had major implications for the provision of substance abuse treatment services to women. The goal of this analysis was to examine (a) changes in the proportion of women clients served within different types of treatment facilities and (b) the services provided in these facilities. Data were analyzed from national surveys of treatment providers for the period of 1987 to 1998. Overall, there were gradual increases in the proportion of women clients across treatment facilities and greater concentrations of women in more intensive treatment modalities. The provision of childcare increased over time, particularly in programs with only women clients. Treatment facilities in which there were higher proportions of women generally had higher rates of providing services related to pregnancy, parenting, and domestic violence. These findings can be used to assess the adequacy of service delivery to women in substance abuse treatment.

Ambulatory Care↗