Development of QSAR models to predict blood-brain barrier permeability

Assessing drug permeability across the blood-brain barrier (BBB) is important when evaluating the abuse potential of new pharmaceuticals as well as developing novel therapeutics that target central nervous system disorders. One of the gold-standard in vivo methods for determining BBB permeability is rodent log BB; however, like most in vivo methods, it is time-consuming and expensive. In the present study, two statistical-based quantitative structure-activity relationship (QSAR) models were developed to predict BBB permeability of drugs based on their chemical structure. The in vivo BBB permeability data were harvested for 921 compounds from publicly available literature, non-proprietary drug approval packages, and University of Washington's Drug Interaction Database. The cross-validation performance statistics for the BBB models ranged from 82 to 85% in sensitivity and 80-83% in negative predictivity. Additionally, the performance of newly developed models was assessed using an external validation set comprised of 83 chemicals. Overall, performance of individual models ranged from 70 to 75% in sensitivity, 70-72% in negative predictivity, and 78-86% in coverage. The predictive performance was further improved to 93% in coverage by combining predictions across the two software programs. These new models can be rapidly deployed to predict blood brain barrier permeability of pharmaceutical candidates and reduce the use of experimental animals.

Racial and ethnic differences in cognitive health appraisals: a comparison of non-Hispanic White, non-Hispanic Black, and Hispanic older adults

OBJECTIVES

To investigate the relationship between cognitive performance and cognitive health appraisals across non-Hispanic White, non-Hispanic Black, and Hispanic older adults in the United States and to explore within-group variations by examining interactions between cognitive performance and background and health variables.

METHOD

The sample (N = 3,099) included 2,260 non-Hispanic White, 498 non-Hispanic Black, and 341 Hispanic adults aged 65 or older, from the 2016-2017 Harmonized Cognitive Assessment Protocol. Regression models of cognitive health appraisals, indicated by self-rated cognitive health, were examined in the entire sample and in racial and ethnic subgroups to test direct and interactive effects of cognitive performance, indicated by the Mini-Mental State Examination (MMSE).

RESULTS

The regression model for the entire sample showed direct effects of cognitive performance and race/ethnicity on cognitive health appraisals, as well as a significant interaction between cognitive performance and being non-Hispanic Black. Cognitive performance and cognitive health appraisals were positively associated in non-Hispanic Whites but not significantly associated in non-Hispanic Blacks. Our subsequent analysis within each racial/ethnic group showed that the effect of cognitive performance in non-Hispanic Blacks and Hispanics became either reversed or nonsignificant when background and health variables were considered. Modification by age or chronic medical conditions in each racial and ethnic group was also observed.

CONCLUSION

Overall, these findings suggest that perceptions and appraisals of cognitive health vary by race and ethnicity and hold implications for how these differences should be considered in research and practice with diverse groups of older adults.

In silico approaches in organ toxicity hazard assessment: current status and future needs in predicting liver toxicity

Hepatotoxicity is one of the most frequently observed adverse effects resulting from exposure to a xenobiotic. For example, in pharmaceutical research and development it is one of the major reasons for drug withdrawals, clinical failures, and discontinuation of drug candidates. The development of faster and cheaper methods to assess hepatotoxicity that are both more sustainable and more informative is critically needed. The biological mechanisms and processes underpinning hepatotoxicity are summarized and experimental approaches to support the prediction of hepatotoxicity are described, including toxicokinetic considerations. The paper describes the increasingly important role of in silico approaches and highlights challenges to the adoption of these methods including the lack of a commonly agreed upon protocol for performing such an assessment and the need for in silico solutions that take dose into consideration. A proposed framework for the integration of in silico and experimental information is provided along with a case study describing how computational methods have been used to successfully respond to a regulatory question concerning non-genotoxic impurities in chemically synthesized pharmaceuticals.

Evaluating kratom alkaloids using PHASE

Kratom is a botanical substance that is marketed and promoted in the US for pharmaceutical opioid indications despite having no US Food and Drug Administration approved uses. Kratom contains over forty alkaloids including two partial agonists at the mu opioid receptor, mitragynine and 7-hydroxymitragynine, that have been subjected to the FDA's scientific and medical evaluation. However, pharmacological and toxicological data for the remaining alkaloids are limited. Therefore, we applied the Public Health Assessment via Structural Evaluation (PHASE) protocol to generate in silico binding profiles for 25 kratom alkaloids to facilitate the risk evaluation of kratom. PHASE demonstrates that kratom alkaloids share structural features with controlled opioids, indicates that several alkaloids bind to the opioid, adrenergic, and serotonin receptors, and suggests that mitragynine and 7-hydroxymitragynine are the strongest binders at the mu opioid receptor. Subsequently, the in silico binding profiles of a subset of the alkaloids were experimentally verified at the opioid, adrenergic, and serotonin receptors using radioligand binding assays. The verified binding profiles demonstrate the ability of PHASE to identify potential safety signals and provide a tool for prioritizing experimental evaluation of high-risk compounds.

Transitioning to composite bacterial mutagenicity models in ICH M7 (Q)SAR analyses

The International Council on Harmonisation (ICH) M7(R1) guideline describes the use of complementary (quantitative) structure-activity relationship ((Q)SAR) models to assess the mutagenic potential of drug impurities in new and generic drugs. Historically, the CASE Ultra and Leadscope software platforms used two different statistical-based models to predict mutations at G-C (guanine-cytosine) and A-T (adenine-thymine) sites, to comprehensively assess bacterial mutagenesis. In the present study, composite bacterial mutagenicity models covering multiple mutation types were developed. These new models contain more than double the number of chemicals (n = 9,254 and n = 13,514) than the corresponding non-composite models and show better toxicophore coverage. Additionally, the use of a single composite bacterial mutagenicity model simplifies impurity analysis in an ICH M7 (Q)SAR workflow by reducing the number of model outputs requiring review. An external validation set of 388 drug impurities representing proprietary pharmaceutical chemical space showed performance statistics ranging from of 66-82% in sensitivity, 91-95% in negative predictivity and 96% in coverage. This effort represents a major enhancement to these (Q)SAR models and their use under ICH M7(R1), leading to improved patient safety through greater predictive accuracy, applicability, and efficiency when assessing the bacterial mutagenic potential of drug impurities.

Assessing the Structural and Pharmacological Similarity of Newly Identified Drugs of Abuse to Controlled Substances Using Public Health Assessment via Structural Evaluation

The US Food and Drug Administration's Center for Drug Evaluation and Research (CDER) developed an investigational Public Health Assessment via Structural Evaluation (PHASE) methodology to provide a structure-based evaluation of a newly identified opioid's risk to public safety. PHASE utilizes molecular structure to predict biological function. First, a similarity metric quantifies the structural similarity of a new drug relative to drugs currently controlled in the Controlled Substances Act (CSA). Next, software predictions provide the primary and secondary biological targets of the new drug. Finally, molecular docking estimates the binding affinity at the identified biological targets. The multicomponent computational approach coupled with expert review provides a rapid, systematic evaluation of a new drug in the absence of in vitro or in vivo data. The information provided by PHASE has the potential to inform law enforcement agencies with vital information regarding newly emerging illicit opioids.

CIIPro: a new read-across portal to fill data gaps using public large-scale chemical and biological data

Summary

We have developed a public Chemical In vitro–In vivo Profiling (CIIPro) portal, which can automatically extract in vitro biological data from public resources (i.e. PubChem) for user-supplied compounds. For compounds with in vivo target activity data (e.g. animal toxicity testing results), the integrated cheminformatics algorithm will optimize the extracted biological data using in vitro–in vivo correlations. The resulting in vitro biological data for target compounds can be used for read-across risk assessment of target compounds. Additionally, the CIIPro portal can identify the most similar compounds based on their optimized bioprofiles. The CIIPro portal provides new powerful assessment capabilities to the scientific community and can be easily integrated with other cheminformatics tools.

Availability and Implementation

ciipro.rutgers.edu.

Contact

danrusso@scarletmail.rutgers.edu or hao.zhu99@rutgers.edu

Predicting opioid receptor binding affinity of pharmacologically unclassified designer substances using molecular docking

Opioids represent a highly-abused and highly potent class of drugs that have become a significant threat to public safety. Often there are little to no pharmacological and toxicological data available for new, illicitly used and abused opioids, and this has resulted in a growing number of serious adverse events, including death. The large influx of new synthetic opioids permeating the street-drug market, including fentanyl and fentanyl analogs, has generated the need for a fast and effective method to evaluate the risk a substance poses to public safety. In response, the US FDA’s Center for Drug Evaluation and Research (CDER) has developed a rapidly-deployable, multi-pronged computational approach to assess a drug’s risk to public health. A key component of this approach is a molecular docking model to predict the binding affinity of biologically uncharacterized fentanyl analogs to the mu opioid receptor. The model was validated by correlating the docking scores of structurally diverse opioids with experimentally determined binding affinities. Fentanyl derivatives with sub-nanomolar binding affinity at the mu receptor (e.g. carfentanil and lofentanil) have significantly lower binding scores, while less potent fentanyl derivatives have increased binding scores. The strong correlation between the binding scores and the experimental binding affinities suggests that this approach can be used to accurately predict the binding strength of newly identified fentanyl analogs at the mu receptor in the absence of in vitro data and may assist in the temporary scheduling of those substances that pose a risk to public safety.

In silico toxicology protocols

The present publication surveys several applications of in silico (i.e., computational) toxicology approaches across different industries and institutions. It highlights the need to develop standardized protocols when conducting toxicity-related predictions. This contribution articulates the information needed for protocols to support in silico predictions for major toxicological endpoints of concern (e.g., genetic toxicity, carcinogenicity, acute toxicity, reproductive toxicity, developmental toxicity) across several industries and regulatory bodies. Such novel in silico toxicology (IST) protocols, when fully developed and implemented, will ensure in silico toxicological assessments are performed and evaluated in a consistent, reproducible, and well-documented manner across industries and regulatory bodies to support wider uptake and acceptance of the approaches. The development of IST protocols is an initiative developed through a collaboration among an international consortium to reflect the state-of-the-art in in silico toxicology for hazard identification and characterization. A general outline for describing the development of such protocols is included and it is based on in silico predictions and/or available experimental data for a defined series of relevant toxicological effects or mechanisms. The publication presents a novel approach for determining the reliability of in silico predictions alongside experimental data. In addition, we discuss how to determine the level of confidence in the assessment based on the relevance and reliability of the information.

Predictive Modeling of Estrogen Receptor Binding Agents Using Advanced Cheminformatics Tools and Massive Public Data

Estrogen receptors (ERα) are a critical target for drug design as well as a potential source of toxicity when activated unintentionally. Thus, evaluating potential ERα binding agents is critical in both drug discovery and chemical toxicity areas. Using computational tools, e.g., Quantitative Structure-Activity Relationship (QSAR) models, can predict potential ERα binding agents before chemical synthesis. The purpose of this project was to develop enhanced predictive models of ERα binding agents by utilizing advanced cheminformatics tools that can integrate publicly available bioassay data. The initial ERα binding agent data set, consisting of 446 binders and 8307 non-binders, was obtained from the Tox21 Challenge project organized by the NIH Chemical Genomics Center (NCGC). After removing the duplicates and inorganic compounds, this data set was used to create a training set (259 binders and 259 non-binders). This training set was used to develop QSAR models using chemical descriptors. The resulting models were then used to predict the binding activity of 264 external compounds, which were available to us after the models were developed. The cross-validation results of training set [Correct Classification Rate (CCR) = 0.72] were much higher than the external predictivity of the unknown compounds (CCR = 0.59). To improve the conventional QSAR models, all compounds in the training set were used to search PubChem and generate a profile of their biological responses across thousands of bioassays. The most important bioassays were prioritized to generate a similarity index that was used to calculate the biosimilarity score between each two compounds. The nearest neighbors for each compound within the set were then identified and its ERα binding potential was predicted by its nearest neighbors in the training set. The hybrid model performance (CCR = 0.94 for cross validation; CCR = 0.68 for external prediction) showed significant improvement over the original QSAR models, particularly for the activity cliffs that induce prediction errors. The results of this study indicate that the response profile of chemicals from public data provides useful information for modeling and evaluation purposes. The public big data resources should be considered along with chemical structure information when predicting new compounds, such as unknown ERα binding agents.

Curating and Preparing High-Throughput Screening Data for Quantitative Structure-Activity Relationship Modeling

Publicly available bioassay data often contains errors. Curating massive bioassay data, especially high-throughput screening (HTS) data, for Quantitative Structure-Activity Relationship (QSAR) modeling requires the assistance of automated data curation tools. Using automated data curation tools are beneficial to users, especially ones without prior computer skills, because many platforms have been developed and optimized based on standardized requirements. As a result, the users do not need to extensively configure the curation tool prior to the application procedure. In this chapter, a freely available automatic tool to curate and prepare HTS data for QSAR modeling purposes will be described.

Developing Enhanced Blood-Brain Barrier Permeability Models: Integrating External Bio-Assay Data in QSAR Modeling

PURPOSE

Experimental Blood-Brain Barrier (BBB) permeability models for drug molecules are expensive and time-consuming. As alternative methods, several traditional Quantitative Structure-Activity Relationship (QSAR) models have been developed previously. In this study, we aimed to improve the predictivity of traditional QSAR BBB permeability models by employing relevant public bio-assay data in the modeling process.

METHODS

We compiled a BBB permeability database consisting of 439 unique compounds from various resources. The database was split into a modeling set of 341 compounds and a validation set of 98 compounds. Consensus QSAR modeling workflow was employed on the modeling set to develop various QSAR models. A five-fold cross-validation approach was used to validate the developed models, and the resulting models were used to predict the external validation set compounds. Furthermore, we used previously published membrane transporter models to generate relevant transporter profiles for target compounds. The transporter profiles were used as additional biological descriptors to develop hybrid QSAR BBB models.

RESULTS

The consensus QSAR models have R(2) = 0.638 for five-fold cross-validation and R(2) = 0.504 for external validation. The consensus model developed by pooling chemical and transporter descriptors showed better predictivity (R(2) = 0.646 for five-fold cross-validation and R(2) = 0.526 for external validation). Moreover, several external bio-assays that correlate with BBB permeability were identified using our automatic profiling tool.

CONCLUSIONS

The BBB permeability models developed in this study can be useful for early evaluation of new compounds (e.g., new drug candidates). The combination of chemical and biological descriptors shows a promising direction to improve the current traditional QSAR models.

Big data in chemical toxicity research: the use of high-throughput screening assays to identify potential toxicants

High-throughput screening (HTS) assays that measure the in vitro toxicity of environmental compounds have been widely applied as an alternative to in vivo animal tests of chemical toxicity. Current HTS studies provide the community with rich toxicology information that has the potential to be integrated into toxicity research. The available in vitro toxicity data is updated daily in structured formats (e.g., deposited into PubChem and other data-sharing web portals) or in an unstructured way (papers, laboratory reports, toxicity Web site updates, etc.). The information derived from the current toxicity data is so large and complex that it becomes difficult to process using available database management tools or traditional data processing applications. For this reason, it is necessary to develop a big data approach when conducting modern chemical toxicity research. In vitro data for a compound, obtained from meaningful bioassays, can be viewed as a response profile that gives detailed information about the compound's ability to affect relevant biological proteins/receptors. This information is critical for the evaluation of complex bioactivities (e.g., animal toxicities) and grows rapidly as big data in toxicology communities. This review focuses mainly on the existing structured in vitro data (e.g., PubChem data sets) as response profiles for compounds of environmental interest (e.g., potential human/animal toxicants). Potential modeling and mining tools to use the current big data pool in chemical toxicity research are also described.

Big data in chemical toxicity research: the use of high-throughput screening assays to identify potential toxicants

High-throughput screening (HTS) assays that measure the in vitro toxicity of environmental compounds have been widely applied as an alternative to in vivo animal tests of chemical toxicity. Current HTS studies provide the community with rich toxicology information that has the potential to be integrated into toxicity research. The available in vitro toxicity data is updated daily in structured formats (e.g., deposited into PubChem and other data-sharing web portals) or in an unstructured way (papers, laboratory reports, toxicity Web site updates, etc.). The information derived from the current toxicity data is so large and complex that it becomes difficult to process using available database management tools or traditional data processing applications. For this reason, it is necessary to develop a big data approach when conducting modern chemical toxicity research. In vitro data for a compound, obtained from meaningful bioassays, can be viewed as a response profile that gives detailed information about the compound's ability to affect relevant biological proteins/receptors. This information is critical for the evaluation of complex bioactivities (e.g., animal toxicities) and grows rapidly as big data in toxicology communities. This review focuses mainly on the existing structured in vitro data (e.g., PubChem data sets) as response profiles for compounds of environmental interest (e.g., potential human/animal toxicants). Potential modeling and mining tools to use the current big data pool in chemical toxicity research are also described.

Effect of carbon nanotube addition on the wear behavior of basalt/epoxy woven composites

The effect of acid-treated carbon nanotube (CNT) addition on the wear and dynamic mechanical thermal properties of basalt/epoxy woven composites was investigated in this study. Basalt/CNT/epoxy composites were fabricated by impregnating woven basalt fibers into epoxy resin mixed with 1 wt% CNTs which were acid-treated. Wear and DMA (dynamic mechanical analyzer) tests were performed on basalt/epoxy composites and basalt/CNT/epoxy composites. The results showed that the addition of the acid-treated CNTs improved the wear properties of basalt/epoxy woven composites. Specifically, the friction coefficient of the basalt/epoxy composite was stabilized in the range of 0.5-0.6 while it fell in the range of 0.3-0.4 for basalt/CNT/epoxy composites. The wear volume loss of the basalt/CNT/epoxy composites was approximately 68% lower than that of the basalt/epoxy composites. The results also showed that the glass transition temperature of basalt/CNT/epoxy composites was higher than that of basalt/epoxy composites. The improvement of wear properties of basalt/epoxy composites by the addition of acid-treated CNTs was caused by the homogeneous load transfer between basalt fibers and epoxy matrix due to the reinforcement of CNTs.

Tailored lay health worker intervention improves breast cancer screening outcomes in non-adherent Korean-American women

Despite rapidly increasing incidence rates of breast cancer, recent immigrants such as Korean-American (KA) women report disproportionately lower utilization of screening tests compared with other ethnic groups. Early screening of breast cancer for this population may be greatly facilitated by indigenous lay health workers (LHWs). We conducted an intervention trial with a 6-month follow-up. Trained LHWs recruited 100 KA women 40 years of age or older who had not had a mammogram during the past 2 years. Ninety-three completed follow-up questionnaires. A 120-min, in-class education combined with LHW follow-up counseling and navigation assistance through the health care system was provided. Rates of breast cancer screening behaviors significantly increased at 6 months (P < 0.001); changes between pre- and post-intervention were 31.9% for mammography, 23% for clinical breast examination and 36.2% for breast self-examination. Modesty toward screening significantly decreased over time, but we did not find any significant differences in breast cancer knowledge and beliefs before and after the intervention. Results support the efficacy of this neighborhood-based, culturally sensitive intervention. Further research should seek to replicate these findings and to incorporate more self-care skills such as health literacy when designing an intervention program for linguistically and culturally isolated immigrant women.

Evaluation of the training of Korean community health workers for chronic disease management

The use of community health workers (CHWs) or lay health advisors has been increasingly popular as an effective means of secondary prevention for cardiovascular health in hard-to-reach, underserved populations. Yet, published evaluations of the CHW training programs are rare. The purpose of this article is to report the results of an evaluation of a CHW training program for hypertension and diabetes management for Korean-American seniors. Forty-eight hours of training was developed and delivered to 12 Korean CHWs. Evaluation of the training program involved CHW surveys, trainer observation and debriefing and CHW focus groups. Testing of CHW knowledge showed that all CHWs met the minimum required knowledge level of 70%. Independent ratings by two trainer observations revealed that the overall CHW performance was satisfactory. Both CHW ratings and focus group data indicated that the training program met their expectation (average 9.3 on a 10-point scale) and was successful in empowering them to assume their role as a 'health initiator', 'health advertising agent' or 'health role model'. While this course is judged to be effective in general, future research is warranted to determine whether CHW provision of care and support will affect health outcomes in the target population.

17beta-Estradiol potentiates field excitatory postsynaptic potentials within each subfield of the hippocampus with greatest potentiation of the associational/commissural afferents of CA3

We sought to determine the impact of 17beta-estradiol throughout the hippocampal trisynaptic pathway and to investigate the afferent fiber systems within CA1 and CA3 in detail. To achieve this objective, we utilized multielectrode arrays to simultaneously record the field excitatory postsynaptic potentials from the CA1, dentate gyrus, and CA3 of rat hippocampal slices in the presence or absence of 100 pM 17beta-estradiol. We confirmed our earlier findings in CA1, where 17beta-estradiol significantly increased field excitatory postsynaptic potentials amplitude (20%+/-3%) and slope (22%+/-7%). 17beta-Estradiol significantly potentiated the field excitatory postsynaptic potentials in dentate gyrus, amplitude (15%+/-4%) and slope (17%+/-5), and in CA3, amplitude (15%+/-4%) and slope (19%+/-5%). Using a high-density multielectrode array, we sought to determine the source of potentiation in CA1 and CA3 by determining the impact of 17beta-estradiol on the apical afferents and the basal afferents within CA1 and on the mossy fibers and the associational/commissural fibers within CA3. In CA1, 17beta-estradiol induced a modest increase in the amplitude (7%+/-2%) and slope (9%+/-3%) following apical stimulation with similar magnitude of increase following basal stimulation amplitude (10%+/-2%) and slope (12%+/-3%). In CA3, 17beta-estradiol augmented the mossy fiber amplitude (15%+/-3%) and slope (18%+/-6%) and the associational/commissural fiber amplitude (31%+/-13%) and slope (40%+/-15%). These results indicate that 17beta-estradiol potentiated synaptic transmission in each subfield of the hippocampal slice, with the greatest magnitude of potentiation at the associational/commissural fibers in CA3. 17beta-Estradiol regulation of CA3 responses provides a novel site of 17beta-estradiol action that corresponds to the density of estrogen receptors within the hippocampus. The implications of 17beta-estradiol potentiation of the field potential in each of the hippocampal subfields and in particular CA3 associational/commissural fibers for memory function and clinical assessment are discussed.

Segregation analysis of waist circumference, hip circumference and waist-to-hip ratio in the Korean Nationwide Family Study

AIM

A central distribution of adipose tissue is frequently associated with cardiovascular disease and its risk factors. In this study, we investigated environmental, familial and genetic influences on waist circumference (WC), hip circumference (HC) and waist-to-hip ratio (WHR) in 2507 members of 435 families who had participated in the Korean Nationwide Health Examination Survey.

METHOD

Maximum likelihood methods were used to fit several genetic and nongenetic models of inheritance to these data to determine whether an unobserved Mendelian major gene could explain the familial distribution of WC, HC and WHR. Adjustments for age, age(2), body mass index, smoking, alcohol consumption and exercise were carried out separately for males and females by multiple regression procedures for WC, HC and WHR phenotypes prior to segregation analysis. Regression models were used to test genetic and non-genetic models in these 435 families.

RESULTS

Segregation analysis did not provide statistical evidence of a major gene controlling either HC or WHR. Mendelian single-locus models with two underlying genotypic distributions were best supported by these data on WC, and this putative major gene explained the 22.4% of variance in adjusted WC.

CONCLUSION

Future linkage studies may be worthwhile to further clarify the mechanisms controlling WC.

Prevalence and factors associated with high blood pressure in Korean Americans

This study, conducted from October 1998 to February 1999, included a cross-sectional epidemiological survey administered to Korean Americans (KAs) living in Maryland (N = 761). One third (32%) of participants had high blood pressure (HPB: SBP > or = 140 mm Hg and/or DBP > or = 90 mm Hg or were on hypertension medication). HBP was more common among males (35%) than females (30%) and those who were aged 50 years or older (53%) compared to those who were less than 50 years old (12%). The prevalence of HBP in Maryland KAs was found to be much higher than in other Americans (24%) and in their counterparts in Korea (22% overall: 29% in males, 11% in females). Only 40% of the hypertensive KAs were taking HBP medication, and 74% of those did not have controlled HBPs. Further, multivariate logistic analyses were conducted to estimate the relative biobehavioral risk factors related to hypertension. Several significant risk factors were identified, including family history of HBP, gender, level of education, level of acculturation, regular exercise, and being overweight. Findings from this study indicate that culturally relevant approaches to prevention and treatment of HBP are urgently needed to address the HBP problem in Korean Americans.

Cancer screening behaviors among Korean-American women

The goals of this study were to evaluate breast and cervical cancer screening tests and to examine the correlates of cancer screening behaviors. A cross-sectional face-to-face survey of 438 Korean-American women residing in Maryland was conducted. About 50% of women age 18 and older had had a Pap smear and 46.6% of these women age 40 and older had had a mammogram in the past 2 years. In multiple logistic regression analyses, the strongest correlate of screening behaviors was having a regular medical checkup. Age and acculturation were found to be important correlates of cancer screening tests: Women less than 50 years of age were more likely to have cancer screening tests than those 50 years and older. English language proficiency was associated with having a mammogram and the proportion of life spent in the United States was associated with having a Pap smear. Employment interacted with marital status for a Pap smear, with those married and unemployed being less likely to have a Pap smear than women who were both married and employed. For strategies to increase cancer-screening tests among Korean-American women, we need to aim at developing culturally appropriate educational programs about cancer for less acculturated and recent immigrants.

Cardiovascular disease risk factors in Korean American elderly

An in-depth cardiovascular risk factor assessment was carried out in a sample of 205 Korean American elderly in Maryland, consisting of 75 males and 130 females aged 60 to 89 years (mean age = 69.9 +/- 6.5 years). Six risk factors were assessed in each participant: high blood pressure, current smoking, high blood cholesterol, overweight, sedentary lifestyle, and diabetes. The findings of this cross-sectional study suggested that high blood pressure was the leading cardiovascular disease risk factor among Korean American elderly (71%), followed by high blood cholesterol (53%), overweight (43%), sedentary life style (24%), diabetes (18%), and smoking (7%). Two thirds of the sample had multiple cardiovascular disease risk factors. The pattern of prevalence and risk factors that was observed was consistent with the distribution of multiple risk factors in that the combination of high blood pressure, high blood cholesterol, and overweight was most common in Korean American elderly (62%). These findings indicate that culturally relevant and salient strategies are needed to reduce multiple risk factors in this population.

Relationship of alcohol and illicit drug use with high blood pressure care and control among urban hypertensive Black men

OBJECTIVE

To examine the relationships among alcohol and illicit drug use and high blood pressure (HBP) care and control.

DESIGN

Baseline cross-sectional data from an ongoing clinical trial evaluating the effectiveness of a HBP care program was utilized.

METHODS

Data collected at baseline on 309 urban hypertensive Black men, aged 18-54, included: socio-demographics, health status, HBP care behaviors, alcohol and illicit drug use, urine screen for illicit drug use, and blood pressure (BP).

RESULTS

Men using alcohol and illicit drugs were less likely to report having medical insurance, having a doctor for HBP care, engaging in critical patient behaviors for HBP control, being on HBP medications, and compliance with HBP medication regimen. Alcohol and illicit drug users were more likely to eat high fat/high salt foods and significantly more likely to smoke cigarettes. In comparison to abstainers, men who used both alcohol and illicit drugs were significantly more likely to have uncontrolled BP and higher systolic blood pressure (SBP).

CONCLUSIONS

Alcohol and illicit drug use were negatively associated with HBP care behaviors. Thus, BP was poorly controlled in this group of alcohol and illicit drug users. Screening, counseling, and treatment for alcohol and illicit drug use should be essential components in comprehensive HBP care.

Development and testing of the Hill-Bone Compliance to High Blood Pressure Therapy Scale

The Hill-Bone Compliance to High Blood Pressure Therapy Scale assesses patient behaviors for three important behavioral domains of high blood pressure treatment: 1) reduced sodium intake; 2) appointment keeping; and 3) medication taking. This scale is comprised of 14 items in three subscales. Each item is a four point Likert type scale. The content validity of the scale was assessed by a relevant literature review and an expert panel, which focused on cultural sensitivity and appropriateness of the instrument for low literacy. Internal consistency reliability and predictive validity of the scale were evaluated using two community based samples of hypertensive adults enrolled in clinical trials of high blood pressure care and control. The standardized alpha for the total scale were 0.74 and 0.84, and the average interitem correlations of the 14 items were 0.18 and 0.28, respectively. The construct and predictive validity of the scale was assessed by factor analysis and by testing of theoretically derived hypotheses regarding whether the scale demonstrated consistent and expected relationships with related variables. In this study, high compliance scale scores predicted significantly lower levels of blood pressure and blood pressure control. Moreover, high compliance scale scores at the baseline were significantly associated with blood pressure control at both baseline and at follow up in the two independent samples. This brief instrument provides a simple method for clinicians in various settings to use to assess patients' self reported compliance levels and to plan appropriate interventions.

The contexts of adherence for African Americans with high blood pressure

The contexts of adherence for African Americans with high blood pressure African American men between the ages of 18 and 49 years have the lowest rates of awareness, treatment and control of high blood pressure (HBP) of all age/race/gender groups in the United States. A qualitative study was done to gain an understanding of urban black males' experiences of living with HBP. In-depth semi-structured interviews were conducted with 19 black males. The interviews explored perceptions of health, health problems and priorities, and concerns of daily living that influenced appointment keeping and medication taking. The sample was a subset of 309 men participating in a 3-year clinical trial to improve HBP control in an inner city African-American population. Content analysis of transcribed interviews identified the following themes and related concerns: (a) personal contexts: meaning of health, high blood pressure and treatments; (b) social context: living as a young black male in an urban environment; and (c) cultural context of relating: patient-provider relationship can make a difference. Influencing participants' responses were: interpreting symptoms; adjusting medication taking; protecting personal privacy; allocating limited resources; dealing with addiction; and feeling cared for by a health care provider. Adherence appeared to be multifaceted and changing depending upon: the men's social, economic and personal circumstances; empathetic and non-judgemental assistance from providers; financial concerns and employment; and drug addiction. Findings are useful in refining high blood pressure interventions.

Isolation and analysis of the 3'-untranslated regions of the human relaxin H1 and H2 genes

The human has two relaxins, termed H1 and H2, both of which are biologically active and co-expressed in the decidua, placenta and prostate; in the corpus luteum, the main source of circulating relaxin, only the H2 form is expressed. The reasons for this differential expression of the relaxin genes are unknown. The possibility that their 3'-untranslated regions (UTRs) contribute to this differential expression by affecting their mRNA stabilities was investigated. Thus the 3'-UTRs of both relaxin genes were isolated through a combined 3'-rapid amplification of cDNA ends-PCR (RACE-PCR) using poly (A)(+)RNA from human decidua, placenta, prostate and corpus luteum. The sequences obtained for each 3'-UTR were identical in the tissues examined, were AT-rich (72%) and showed 91% homology between relaxin H1 and H2 when maximally aligned to include several gaps, the significance of which is unknown. Relaxin H1 has two, and relaxin H2 has one, poly (A)(+) signal, in addition to one cytoplasmic polyadenylation element 30 nucleotides upstream of this. The mRNA levels of relaxin H1 and H2 in the prostate adenocarcinoma LNCaP.FGC cell line were determined by quantitative competitive RT-PCR. Relaxin H1 had a 10-fold greater number of molecules (approximately 2.5x10(7)) per microgram of total RNA than relaxin H2 (approximately 2.5x10(6)). The stability of relaxin H1 and H2 mRNAs were compared in LNCaP cells treated with the transcription inhibitor actinomycin D (10 mM) for 0, 1, 2, 4, 8, 10, 14, or 24 h. Half-lives of 3.17 days for relaxin H1 mRNA and 11. 4 h for relaxin H2 mRNA were obtained from semi-logarithmic plots. Thus both mRNAs are relatively stable; however, relaxin H1 mRNA is considerably more stable than relaxin H2, at least in LNCaP cells. This difference in their mRNA stability may partly explain the greater level of expression of relaxin H1 in these cells.

Barriers to hypertension care and control in young urban black men

Barriers to high blood pressure (HBP) care and control have been reported in the literature for > 30 years. Few reports on barriers, however, have focused on the young black man with HBP, the age/sex/race group with the highest rates of early severe and complicated HBP and the lowest rates of awareness, treatment, and control. In a randomized clinical trial of comprehensive care for hypertensive young urban black men, factors potentially associated with care and control were assessed at baseline for the 309 enrolled men. A majority of the men encountered a variety of barriers including economic, social, and lifestyle obstacles to adequate BP care and control, including no current HBP care (49%), risk of alcoholism (62%), use of illicit drugs (45%), social isolation (47%), unemployment (40%), and lack of health insurance (51%). Having health insurance (odds ratio = 7.20, P = .00) and a negative urine drug screen (odds ratio = .56, P = .04) were significant predictors of being in HBP care. Low alcoholism risk and employment were identified as significant predictors of compliance with HBP medication-taking behavior. Men currently using illicit drugs were 2.64 times less likely to have controlled BP compared with their counterparts who did not use illicit drugs, and men currently taking HBP medication were 63 times more likely have controlled BP compared with men not taking HBP medication. Comprehensive interventions are needed to address socioeconomic and lifestyle issues as well as other barriers to care and treatment, if HBP care is to be salient and effective in this high risk group.

Quantitative single-cell-reverse transcription-PCR demonstrates that A-current magnitude varies as a linear function of shal gene expression in identified stomatogastric neurons

Different Shaker family alpha-subunit genes generate distinct voltage-dependent K+ currents when expressed in heterologous expression systems. Thus it generally is believed that diverse neuronal K+ current phenotypes arise, in part, from differences in Shaker family gene expression among neurons. It is difficult to evaluate the extent to which differential Shaker family gene expression contributes to endogenous K+ current diversity, because the specific Shaker family gene or genes responsible for a given K+ current are still unknown for nearly all adult neurons. In this paper we explore the role of differential Shaker family gene expression in creating transient K+ current (IA) diversity in the 14-neuron pyloric network of the spiny lobster, Panulirus interruptus. We used two-electrode voltage clamp to characterize the somatic IA in each of the six different cell types of the pyloric network. The size, voltage-dependent properties, and kinetic properties of the somatic IA vary significantly among pyloric neurons such that the somatic IA is unique in each pyloric cell type. Comparing these currents with the IAs obtained from oocytes injected with Panulirus shaker and shal cRNA (lobster Ishaker and lobster Ishal, respectively) reveals that the pyloric cell IAs more closely resemble lobster Ishal than lobster Ishaker. Using a novel, quantitative single-cell-reverse transcription-PCR method to count the number of shal transcripts in individual identified pyloric neurons, we found that the size of the somatic IA varies linearly with the number of endogenous shal transcripts. These data suggest that the shal gene contributes substantially to the peak somatic IA in all neurons of the pyloric network.

Lobster shal: comparison with Drosophila shal and native potassium currents in identified neurons

The transient potassium (K+) current, or A-current (IA), plays an essential role in shaping the firing properties of identified neurons in the 14-cell pyloric network in the stomatogastric ganglion of the spiny lobster, Panulirus interruptus. The different cells in the pyloric network have distinct IAs. To begin to understand the molecular basis for IA heterogeneity, we examined the relationship between the Panulirus shal current, the IAs in the lateral pyloric (LP) and pyloric dilator (PY) cells, and the Drosophila shal current. After isolating a complete open reading frame for lobster shal 1, which shows significant sequence homology to the fly, mouse, and rat shal homologs, we used a single-cell reverse transcription polymerase chain reaction method to demonstrate that the shal 1 gene was expressed in the LP and PY cells. Next, we compared the lobster shal 1 current generated in a Xenopus oocyte expression system to the IAs in the LP and PY neurons as well as to the Drosophila shal current in Xenopus oocytes. While the transient K+ lobster shal 1 current was similar to the IAs in pyloric neurons, a detailed comparison shows that they are not identical and differ in kinetic and voltage-dependent parameters. The highly homologous lobster and fly shal genes also produce currents with some significant similarities and differences in an oocyte expression system.

Cultural Influences on Depression in Korean Americans

This article does not intend to simplify the emotional world of KAs, nor to generate a stereotype of cultural knowledge about KAs. A practice based on stereotypical knowledge often does more harm than good (Brigham, 1971). Cultures are not indefinitely static systems. Cultural subgroups and the dominant culture in which they reside exchange influences, which results in changing cultural pattern (DHHS, 1993). Consequently, a wide range of individual differences exists in terms of educational status, language sufficiency, acculturation status, and personalities. Although clinicians should acknowledge and be sensitive to a client's cultural background, they need to base clinical decisions on awareness of individual differences. Nevertheless, an understanding of how cultural and social forces affect the vulnerability to depression should guide practitioners in designing and implementing culturally relevant treatment regimens for all clients (Weiss, 1988). Unfortunately, critical questions, such as what specific therapies are necessary for effective treatment of Korean-American clients, has not been found in current research. Systematic and accurate data-based information about KAs are lacking. Future research into the mental health needs of KAs should include assessments of needs in order to provide a basis for planning the prevention and intervention programs to adequately meet Korean Americans' mental health needs.

Caries levels and patterns in head start children in fluoridated and non-fluoridated, urban and non-urban sites in Ohio, USA

The purpose of the study was to determine caries levels and prevalences of previously identified caries patterns in low income children in the primary dentition in Ohio, USA. Children were examined from urban fluoridated (n = 505), urban non-fluoridated (n = 395), non-urban optimal fluoride (n = 183), and non-urban suboptimal fluoride (n = 227) sites. Caries scores were similar for the two sites having optimal fluoride; scores from fluoridated sites were lower than scores from the two suboptimal fluoride sites. Children from all four sites were caries-free ranging from 36% in the urban non-fluoridated site to 50% in the non-urban optimally fluoride site. More children in the suboptimal fluoridated sites had smooth surface lesions than in the optimally fluoridated sites. More children with defect associated lesions had fewer than six (chi 2 = 222; P less than 0.01) carious surfaces than did children with smooth surface lesions.