Demonstration of a third structurally distinct human Ia beta chain by two-dimensional gel electrophoresis.

Previous studies have indicated that HLA-DR homozygous cell lines express two Ia alpha and Ia beta chains that combine to form at least two Ia molecules. This report demonstrates by two-dimensional gel electrophoresis the existence of a third structurally distinct human Ia beta chain on DR2 and DR5 cell lines. This suggests that at least five separate genes control the expression of Ia molecules on HLA-DR homozygous cell lines.

RETRACTED: Differing attenuation coefficients of normal and infarcted myocardium.

There are significant differences in attenuation coefficients between normal and infarcted myocardium measurable with a computerized transaxial tomographic scanner. Additionally, iodinated contrast material administered prior to killing the tests animals resulted in excellent visualization of the blood-myocardial interface at a time when standard radiographs detected no differences between the ventricular cavity and the myocardial wall. These natural and induced changes in attenuation coefficients offer a new approach to evaluating and understanding the processes of tissue injury and death. Their clinical relevance lies in application to the twin problems of myocardial infarction and the structure and function of the cardiac wall.

Schur maps, Young tableaux, and supersymmetric algebra.

It is shown that the Hopf algebra dual of a supersymmetric Hopf algebra admits two presentations, and a natural isomorphism between them is described.

Identification by monoclonal antibodies of an antigen shed by human bladder cancer cells.

The reactivities of two anti-bladder cancer monoclonal antibodies, AN43 and BB369, were characterized. AN43 and BB369 reacted with a majority (greater than 50%) of bladder cancer tissue sections tested by immunoperoxidase staining. When tested against a panel of 27 normal human tissues, AN43 and BB369 reacted only with urothelium and stomach. AN43 and BB369 showed identical binding patterns and competed for binding on bladder cancer cells, suggesting that the two antibodies react with identical or spatially close epitopes. Bound BB369 antibody was rapidly shed from the surface of viable UM-UC-9 human bladder cancer cells. The antigen was found in spent tissue culture medium from the UM-UC-9 human bladder cancer cell line. AN43 and BB369 define a shed bladder tumor-associated antigen with limited distribution on normal tissues. The antigen is different from bladder tumor-associated antigens defined by other monoclonal antibodies and may be useful for the diagnosis and follow-up of patients with bladder cancer.

The importance of physician communication on breast cancer screening of older women.

BACKGROUND: Breast cancer screening rates, especially for mammography, continue to lag for older women, particularly for women older than 65 years. METHODS: We investigated the associations of key variables with reported rates of mammography and clinical breast examination in a sample of 972 women older than 50 years; 724 of them were older than 65 years. They were surveyed in late 1990 through 30-minute bilingual telephone interviews. RESULTS: Although it was hypothesized that race, age, health status, and physician-patient communication variables would influence utilization rates, only the communication variables (and two access variables) significantly predicted a recent mammogram or clinical breast examination. In particular, the style of the communication--the patient's report of the physician's enthusiasm for mammography when it was discussed with women at the office visit--influenced the women's screening behavior significantly. Women who perceived that their physicians had some enthusiasm for mammography were more than four and a half times more likely than women whose physicians had no or little enthusiasm for mammography to have had one within the previous year. Other findings were that about half of the Los Angeles, Calif, women in this study reported a recent mammogram, an increase from the one third who reported one in the previous survey of 1988; a decline in screening was not reported until after age 75 years. About a quarter of the study women, on the other hand, had never been screened despite the long-standing recommendation for regular screening of women older than 50 years and the risk of breast cancer increasing with age. Surprisingly, women at higher risk of breast cancer were not being screened any more systematically than women at lower risk. CONCLUSION: We conclude that improved physician-patient communication skills could be a highly effective and easy-to-learn strategy to increase overall screening rates.

The impact of physician compliance on screening mammography for older women.

Screening mammography is underutilized, even for women older than 50 years for whom there is a general consensus that regular annual screening is appropriate and necessary. To evaluate reasons for this underutilization, we studied a random sample of 517 women in Los Angeles, Calif who were older than 50 years. All women were found to be underscreened, especially women older than 65 years. For example, approximately 35% of women 50 to 64 years old and 47% of women aged 65 years and older never had had even one mammogram. Analyses revealed that the most important factor that predicted whether a women ever had had a mammogram was whether her physician had talked to her about mammography. Women were between four and 12 times more likely, depending on their age group, to have had a mammogram at some time if their physicians discussed it with them. The discussions did not need to be lengthy or complex. These results indicate that physicians need to know that discussing screening mammography with their patients has a major impact on breast cancer screening behaviors.

"Reactive filtration": use of functionalized porous polymer monoliths as scavengers in solution-phase synthesis.

[reaction: see text] Solid functionalized porous monolithic disks with reactive polymer chains grafted to their inner pore surface have been developed for scavenging excess reagents from reaction mixtures. A poly(chloromethylstyrene-co-divinylbenzene) monolith was cut into disks and activated by graft polymerizing 4-vinyl-2,2-dimethylazlactone to its pore surface. In contrast to the direct copolymerization of reactive monomers, grafting increases the accessibility of the reactive groups. Application of the reactive disks is demonstrated in the scavenging of excess amines from reaction mixtures in different solvents.

Mercaptoacetate induces feeding through central opioid-mediated mechanisms in rats.

The endogenous opioid system has been implicated in the mediation of food intake elicited by such regulatory challenges as glucoprivation induced by 2-deoxy-D-glucose (2DG) or food deprivation in rodents. Administration of the free fatty acid oxidation inhibitor, mercaptoacetate (MA), produces a potent short-term increase in feeding in rats, the mechanisms of which have been dissociated from that elicited by 2DG. The present study evaluated whether MA-induced feeding in rats was mediated by the endogenous opioid system through systemic administration of the general opioid antagonist, naltrexone, through central administration of either general, mu, mu(1), kappa(1) or delta opioid antagonists, and through central administration of antisense oligodeoxynucleotide (AS ODN) probes directed against specific exons of either the mu (MOR-1), kappa (KOR-1), kappa(3) (KOR-3/ORL-1) or delta (DOR-1) opioid receptor clones. MA-induced feeding was significantly and dose-dependently reduced by systemic naltrexone (0.005-5 mg/kg); these ingestive effects were quite selective since neither total, ambulatory nor stereotypic activity was affected by either MA itself or MA paired with naltrexone. MA-induced feeding was significantly reduced by central pretreatment with either naltrexone (0.1-20 microgram) or mu-selective (beta-funaltrexamine, 0.1-20 microgram), mu(1)-selective (naloxonazine, 1-20 microgram), kappa(1)-selective (nor-binaltorphamine, 0.1-20 microgram), or delta-selective (naltrindole, 1-20 microgram) opioid receptor antagonists. MA-induced feeding was significantly reduced by AS ODN probes directed against either exons 1, 2 or 3, but not exon 4 of the MOR-1 clone, exon 3, but not exons 1 or 2 of the KOR-1 clone, exons 1 or 2, but not exon 3 of the KOR-3/ORL-1 clone, and exon 1, but not exons 2 or 3 of the DOR-1 clone. These data are discussed in terms of opioid mediation of ingestive responses related to fat, and in terms of potential central sites of action at which lipoprivic ingestive responses might act.

Comparability and representativeness of clinical homeless, community homeless, and domiciled clinic samples: physical and mental health, substance use, and health services utilization.

Evaluating the representativeness of homeless samples is important for generalizing research findings on the homeless and designing interventions targeting their health needs. The present study contrasts homeless and domiciled free-clinic users (216 homeless [132 men, 84 women], 212 domiciled [102 men, 110 women]) and 531 community homeless persons (388 men, 143 women) on latent variables representing substance use, mental and physical health, appearance, life satisfaction, and health services utilization (HSU). Homeless clinic patients equalled the community sample in substance abuse and psychological problems but exceeded the sample in HSU and cleanliness. Homeless clinic users reported more substance abuse, poorer health, greater mental illness and mental HSU, less cleanliness, and lower life satisfaction than domiciled patients. Relationships among the variables are reported, and implications concerning health needs among the homeless are discussed.

Psychosocial predictors of AIDS risk behavior and drug use behavior in homeless and drug addicted women of color.

The present study examined a causal model consisting of personal and social resources, threat appraisal processes, coping styles, and barriers to risk reduction as predictors of general AIDS risk and specific drug use behaviors among homeless African American (N = 714) and Latina (N = 691) women. The model, which was based on a stress and coping framework, supported many of the hypothesized relationships. Active coping was associated with fewer general AIDS risk behaviors for both groups and less specific drug use behavior among African American women. Specific drug use behavior was predicted by high threat appraisal and avoidant coping for both groups. Ethnic differences and implications for intervention are discussed.

Severity of homelessness and adverse birth outcomes.

Predictors and the prevalence of adverse birth outcomes among 237 homeless women interviewed at 78 shelters and meal programs in Los Angeles in 1997 were assessed. It was hypothesized that they would report worse outcomes than national norms, that African Americans would report the worst outcomes because of their greater risk in the general population, and that homelessness severity would independently predict poorer outcomes beyond its association with other adverse conditions. Other predictors included reproductive history, behavioral and health-related variables, psychological trauma and distress, ethnicity, and income. African Americans and Hispanics reported worse outcomes than are found nationally, and African Americans reported the worst outcomes. In a predictive structural equation model, severity of homelessness significantly predicted low birth weight and preterm births beyond its relationship with prenatal care and other risk factors.

Psychosocial correlates and predictors of AIDS risk behaviors, abortion, and drug use among a community sample, of young adult women.

Relations among latent constructs of Social Conformity, Sensation Seeking, Polydrug Use, Sexual Experience, Abortion, and Risky AIDS Behaviors were examined among a community sample of women (N = 438, mean age = 25.5 years) using confirmatory factor analysis (CFA) and predictive structural equation models (SEM). In the CFA, Risky AIDS Behavior was strongly related to more Polydrug Use and less Social Conformity and modestly related to Sexual Experience and Abortions. In SEMs, Social Conformity significantly predicted less Risky AIDS Behavior and less Polydrug Use but did not predict Abortions. Prior Sexual Experience predicted more Polydrug Use and Abortions. We conclude that the same psychological processes and predispositions that relate low social conformity to drug use and other unhealthy behaviors also influence AIDS-risk behaviors, even among a community sample of women.

Conceptualizing the multidimensional nature of self-efficacy: assessment of situational context and level of behavioral challenge to maintain safer sex. National Institute of Mental Health Multisite HIV Prevention Trial Group.

A. Bandura (1991) argued that self-efficacy measurement should be specific both to the situation in which the behavior occurs and level of challenge in that situation. Measures consistent with the 2 dimensions were developed with graded challenge levels and differing gender-appropriate situations. Participants were 1,496 controls in the National Institute of Mental Health Multisite HIV Prevention Trial recruited from STD clinics and health service centers (925 women and 571 men). The authors tested 4 separate-sex confirmatory factor analysis models as follows: (a) Condom negotiation efficacy as a unitary construct across situations and gradation of difficulty; (b) situation as preeminent, which transfers across skills whatever the gradation of difficulty; (c) skill as predominant, irrespective of situation; and (d) a multidimensional design that simultaneously accounts for both situation and graded difficulty. Consistent with Bandura's theory, the multidimensional model provided the best fit for both samples.

Structural equation analyses of clinical subpopulation differences and comparative treatment outcomes: characterizing the daily lives of drug addicts.

The use of structural equation modeling (SEM) is illustrated for comparative treatment outcome research conducted with heterogeneous clinical subpopulations within large multimodality treatment settings. All analyses are accomplished with SEM analogs of more familiar classical multivariate techniques. The effect of the early period of treatment on the daily lives of 486 clients in two drug abuse treatment modalities (methadone maintenance and outpatient counseling) is evaluated. Structured means analysis is used to assess initial differences between modalities on the latent means of 6 latent constructs reflecting daily life. The effect of treatment modality and attrition from the program on daily life latent constructs is evaluated while initial selection differences are statistically controlled. Effect sizes are computed on the basis of SEM parameter estimates. The advantage of SEM over classic multivariate approaches for correcting for selection bias when assessing comparative outcomes is explained.

Impact of parent death and an intervention on the adjustment of adolescents whose parents have HIV/AIDS.

The impact of parental death and the efficacy of a coping-skills intervention were examined on the adjustment of 211 adolescent children of parents with HIV/AIDS (PWH) over a 2-year period. During the follow-up period, 35% of the PWH died. Using longitudinal structural equation model, controlling for prior measures of adjustment at baseline, the authors found that children of deceased PWH reported significantly more emotional distress and problem behaviors 2 years later. Youth randomized with their parent to a coping-skills intervention reported significantly fewer problem behaviors and sexual partners 2 years later. Also, adolescents were better-adjusted 2 years later when their parents had reported less emotional distress and less severe physical health symptoms at baseline. Female adolescents reported more emotional distress at baseline and at 2 years than males; male adolescents reported more problem behaviors at baseline than the females.

Evaluation of a new bladder tumor marker.

Two monoclonal antibodies have been developed that bind to a shed bladder tumor-associated antigen. Preliminary data have demonstrated that antigen-positive tumors shed detectable amounts of antigen in the urine while antigen-negative tumors do not. This antigen may be differentially metabolized by normal and malignant urothelial cells. Further characterization of this antigen and its evaluation as a urinary marker for antigen positive bladder cancers is continuing.