Oxidopyrylium-Alkene [5 + 2] Cycloaddition Conjugate Addition Cascade (C3) Sequences: Scope, Limitation, and Computational Investigations.

Oxidopyrylium-alkene [5 + 2] cycloaddition conjugate addition cascade (C3) sequences are described. Intramolecular cycloadditions involving terminal alkenes, enals, and enones were investigated. Substrates with tethers of varying lengths delivered five- and six-membered carbocycles and heterocycles thus demonstrating the scope and limitation of the cycloaddition-conjugate addition cascade. Several experiments and theoretical calculations provide evidence for the proposed mechanistic pathway.

Investigation of oxidopyrylium-alkene [5+2] cycloaddition conjugate addition cascade (C3) sequences.

Novel oxidopyrylium-alkene [5+2] cycloaddition conjugate addition cascade (C(3)) sequences are described. Various acetoxypyranone-alkenes with pendant nucleophiles undergo [5+2] cycloaddition followed by conjugate addition from the concave face of the intermediate pyranone toward bridged, tetracyclic ethers. In several cases, 3 new rings, 4 new bonds, and 6 new contiguous stereocenters are constructed with excellent diastereoselectivity. Finally, an asynchronous concerted reaction pathway is proposed to explain the high diastereoselectivity of the oxidopyrylium-alkene [5+2] C(3).

Unique reactivity of anti- and syn-acetoxypyranones en route to oxidopyrylium intermediates leading to a cascade process.

Unique reactivity of anti- and syn-acetoxypyranones was observed in oxidopyrylium-alkene [5 + 2] cycloadditions. The subtle interplay between the corresponding acetoxypyranone conformation and steric bulk of tertiary amine bases causes syn-acetoxypyranones to undergo [5 + 2] cycloaddition appreciably faster than anti-acetoxypyranones. Additionally, the efficiency of a cascade process that afforded a novel tetracyclic lactol was determined to be dependent on the relative stereochemistry of each diastereomer, the amine base utilized, and the addition of water.

Alternating current scanning electrochemical microscopy with simultaneous fast-scan cyclic voltammetry.

Fast-scan cyclic voltammetry (FSCV) is combined with alternating current scanning electrochemical microscopy (AC-SECM) for simultaneous measurements of impedance and faradaic current. Scan rates of 10-1000 V s(-1) were used for voltammetry, while a high-frequency (100 kHz), low-amplitude (10 mV rms) sine wave was added to the voltammetric waveform for the ac measurement. Both a lock-in amplifier and an analog circuit were used to measure the amplitude of the resultant ac signal. The effect of the added sine wave on the voltammetry at a carbon fiber electrode was investigated and found to have negligible effect. The combined FSCV and ac measurements were used to provide simultaneous chemical and topographical information about a substrate using a single carbon fiber probe. The technique is demonstrated in living cell culture, where cellular respiration and topography were simultaneously imaged without the addition of a redox mediator. This approach promises to be useful for the topographical and multidimensional chemical imaging of substrates.

Evaluation of a cervical cancer control intervention using lay health workers for Vietnamese American women.

OBJECTIVES: We conducted a trial to evaluate the effectiveness of a cervical cancer control intervention for Vietnamese American women that used lay health workers. METHODS: The study group included 234 women who had not received a Papanicolaou (Pap) test in the last 3 years. Experimental group participants received a lay health worker home visit. Our trial endpoint was Pap test receipt within 6 months of randomization. Pap testing completion was ascertained through women's self-reports and medical record reviews. We examined intervention effects among women who had ever received a Pap test (prior to randomization) and women who had never received a Pap test. RESULTS: Three quarters of the women in the experimental group completed a home visit. Ever-screened experimental group women were significantly more likely to report Pap testing (P < .02) and to have records verifying Pap testing (P < .04) than were ever-screened control group women. There were no significant differences between the trial arms for women who had never been screened. CONCLUSIONS: Our findings indicate that lay health worker-based interventions for Vietnamese American women are feasible to implement and can increase levels of Pap testing use among ever-screened women but not among never-screened women.

Sources of health information among Chinese immigrants to the Pacific Northwest.

BACKGROUND: Chinese immigrants to North America experience cancer-related health disparities and underutilize preventive care. Little is known about Chinese immigrants' sources of health information. METHODS: A population-based survey of Chinese immigrants was conducted in Vancouver, British Columbia, Canada and Seattle, Washington. RESULTS: The study group included 899 individuals. Less than three fourths of the respondents reported receiving health information from health care providers, and only a minority used the Internet as a source of health information. We found significant differences between the sources of health information in Seattle and Vancouver. CONCLUSIONS: Health educators should consider available media outlets as well as the characteristics of a target community when planning intervention programs for Chinese immigrants.

Pap smear receipt among Vietnamese immigrants: the importance of health care factors.

OBJECTIVE: Recent US data indicate that women of Vietnamese descent have higher cervical cancer incidence rates than women of any other race/ethnicity, and lower levels of Pap testing than white, black, and Latina women. Our objective was to provide information about Pap testing barriers and facilitators that could be used to develop cervical cancer control intervention programs for Vietnamese American women. DESIGN: We conducted a cross-sectional, community-based survey of Vietnamese immigrants. Our study was conducted in metropolitan Seattle, Washington, DC. A total of 1532 Vietnamese American women participated in the study. Demographic, health care, and knowledge/belief items associated with previous cervical cancer screening participation (ever screened and screened according to interval screening guidelines) were examined. RESULTS: Eighty-one percentage of the respondents had been screened for cervical cancer in the previous three years. Recent Pap testing was strongly associated (p<0.001) with having a regular doctor, having a physical in the last year, previous physician recommendation for testing, and having asked a physician for testing. Women whose regular doctor was a Vietnamese man were no more likely to have received a recent Pap smear than those with no regular doctor. CONCLUSION: Our findings indicate that cervical cancer screening disparities between Vietnamese and other racial/ethnic groups are decreasing. Efforts to further increase Pap smear receipt in Vietnamese American communities should enable women without a source of health care to find a regular provider. Additionally, intervention programs should improve patient-provider communication by encouraging health care providers (especially male Vietnamese physicians serving women living in ethnic enclaves) to recommend Pap testing, as well as by empowering Vietnamese women to specifically ask their physicians for Pap testing.

Evaluation of a hepatitis B lay health worker intervention for Chinese Americans and Canadians.

Hepatitis B testing is recommended for immigrants from countries where hepatitis B infection is endemic. However, only about one-half of Chinese in North America have received hepatitis B testing. We conducted a randomized controlled trial to evaluate the effectiveness of a hepatitis B lay health worker intervention for Chinese Americans/Canadians. Four hundred and sixty individuals who had never been tested for hepatitis B were identified from community-based surveys of Chinese conducted in Seattle, Washington, and Vancouver, British Columbia. These individuals were randomly assigned to receive a hepatitis B lay health worker intervention or a direct mailing of physical activity educational materials. Follow-up surveys were completed 6 months after randomization. Self-reported hepatitis B testing was verified through medical records review. A total of 319 individuals responded to the follow-up survey (69% response rate). Medical records data verified hepatitis B testing since randomization for 9 (6%) of the 142 experimental group participants and 3 (2%) of the 177 control group participants (P = 0.04). At follow-up, a higher proportion of individuals in the experimental arm than individuals in the control arm knew that hepatitis B can be spread by razors (P < 0.001) and during sexual intercourse (P = 0.07). Our findings suggest that lay health worker interventions can impact hepatitis B-related knowledge. However, our hepatitis B lay health worker intervention had a very limited impact on hepatitis B testing completion. Future research should evaluate other intervention approaches to improving hepatitis B testing rates among Chinese in North America.

Heart disease prevention practices among immigrant Vietnamese women.

BACKGROUND: Cardiovascular disease is a leading cause of death in the United States as well as in many countries around the world, including Vietnam. METHODS: Using data from a household survey of Vietnamese American women aged 20-79 years in Seattle, Washington, collected in 2006 and 2007, we examined heart disease prevention practices. Multivariable analyses were conducted to examine the relationship between demographic factors and preventive behaviors. RESULTS: A total of 1523 immigrant women completed interviews. The average daily consumption of fruits and vegetables was 3.5 servings, and 31% of our sample reported being physically active (engaging in at least 30 minutes of physical activity 5 or more days per week). Few respondents reported being current smokers (1.5%). Over three quarters of women had received a recent blood pressure check and a recent cholesterol check. Age and length of time in the United States were strongly associated with several cardiovascular prevention behaviors. CONCLUSIONS: Our findings confirm the need for continued efforts to develop and implement targeted educational campaigns to reduce the risk of cardiovascular disease among Vietnamese American women.

Development of an ESL curriculum to educate Chinese immigrants about physical activity.

Regular physical activity reduces the risk of many chronic conditions. Multiple studies have shown that Asians in North America engage in less physical activity than the general population. One area for strategic development in the area of health education is the design and evaluation of English as a second language (ESL) curricula. The PRECEDE model and findings from focus groups were used to develop a physical activity ESL curriculum for Chinese immigrants. In general, focus group participants recognized that physical activity contributes to physical and mental wellbeing. However, the benefits of physical activity were most commonly described in terms of improved blood circulation, immune responses, digestion, and reflexes. The importance of peer pressure and the encouragement of friends in adhering to regular physical activity regimens were mentioned frequently. Reported barriers to regular physical activity included lack of time, weather conditions, and financial costs. The ESL curriculum aims to both promote physical activity and improve knowledge, and includes seven different ESL exercises. Our curriculum development methods could be replicated for other health education topics and in other limited English-speaking populations.

Correlates of hepatitis B testing among Chinese Americans.

Chinese Americans are 10 times more likely to be diagnosed with hepatocellular carcinoma (HCC) than their white counterparts. About 80% of HCC's among Asian immigrants are associated with hepatitis B virus (HBV) infection. We used data from in-person interviews of Chinese residents in Seattle to examine factors associated with HBV testing. The survey was completed by 206 men and 236 women (cooperation rate: 58%). Less than one-half (48%) of respondents had been tested for HBV. Factors associated (p < 0.01) with ever having tested in bivariate comparisons included knowing that Chinese are more likely to be infected with HBV than Whites; individuals can be infected with HBV for life; HBV infection can cause liver cancer; not believing that HBV can be prevented by having a positive attitude; having a family member, friend, or medical doctor recommend testing; asking for testing from a medical doctor; and not needing interpreter services. In multiple regression analyses, the following factors were independently associated with testing: believing that Chinese were more likely than Whites to get HBV (p = 0.004), having a doctor recommend testing (p

Heart disease prevention among Chinese immigrants.

There is little information about the heart disease prevention behavior of Asian immigrants. Chinese are the largest Asian sub-group in the United States (US), and 69% of Chinese Americans are foreign-born. Our objective was to describe Chinese immigrants' heart disease prevention practices. A community-based, in-person survey of Chinese men and women was conducted in Seattle during 2005. Our study sample included 395 Chinese immigrants. Only 15% of the respondents consumed five or more servings of fruit/ vegetables per day, and less than one-third (31%) engaged in regular physical activity. Smoking rates were significantly higher among men (21%) than women (1%). About three-quarters (74%) of the study group had received a cholesterol test in the previous five years. Recent immigrants had higher levels of fruit/ vegetable consumption and physical activity than those who had been in the US for 10 years or more. Conversely, longer duration of US residence was positively associated with recent cholesterol testing. Heart disease prevention programs should be developed, implemented, and evaluated in Chinese immigrant populations. These efforts should specifically aim to increase fruit/ vegetable consumption and regular physical activity. Future efforts to increase cholesterol testing should focus on recent immigrants.

Tobacco knowledge and beliefs in Chinese American men.

BACKGROUND: Chinese American men have relatively high smoking rates. However, there are limited data about the tobacco-related knowledge, attitudes, and beliefs of this racial/ethnic group. METHODS: We conducted a community-based telephone survey in Seattle, Washington during 2004. Households were identified by applying a previously validated list of Chinese last names to an electronic version of the Seattle telephone book. Interviews were completed in Cantonese, Mandarin, or English. Survey items addressed tobacco knowledge, cultural beliefs, and practices. RESULTS: The study sample included 168 Chinese American men. Current, former, and never smoking rates were 22%, 42%, and 36%, respectively. Current smokers were less likely to be proficient in English than never smokers, and were less likely to have a regular doctor than former smokers. They also had lower levels of knowledge about the health effects of tobacco, and were more likely to have traditional Chinese cultural beliefs about tobacco use than non-smokers. CONCLUSION: Tobacco use continues to be a public health problem among Chinese American men. Smoking cessation programs should target men with limited English proficiency and those without a regular source of health care. Educational materials should specifically address the negative health effects of smoking. They should also both acknowledge and address Chinese cultural beliefs about tobacco use.

Hepatitis B knowledge and practices among Chinese immigrants to the United States.

INTRODUCTION: Chinese immigrants to the United States experience high rates of liver cancer. Chronic carriage of hepatitis B virus (HBV) is the most common underlying cause of liver cancer among Chinese Americans. Our objective was to describe Chinese immigrants' hepatitis B knowledge, testing, and vaccination levels. METHODS: A community-based, in-person survey of Chinese men and women was conducted in Seattle during 2005. Our study sample included 395 individuals. RESULTS: Less than one-half (48%) of our study group indicated they had received a hepatitis B blood test, and about one-third (31%) indicated they had been vaccinated against hepatitis B. The proportions of respondents who knew HBV can be spread during childbirth, during sexual intercourse, and by sharing razors were 70%, 54%, and 55%, respectively. Less than one-quarter of the study group knew that HBV cannot be spread by eating food that was prepared by an infected person (23%) and by sharing eating utensils with an infected person (16%). DISCUSSION: Over 50% of our respondents did not recall being tested for HBV. Important knowledge deficits about routes of hepatitis B transmission were identified. Continued efforts should be made to develop and implement hepatitis B educational campaigns for Chinese immigrant communities.

Sources of health information among Vietnamese American men.

Vietnamese American men face multiple health disparities compared to white men. Our study objective was to determine the sources of health information used by Vietnamese men in the United States. A population-based, in-person survey was conducted among Vietnamese men in Seattle during 2002. Our survey was completed by 509 Vietnamese men (79% response rate). The most commonly reported sources of health information included Vietnamese newspapers/magazines (73%), Vietnamese and English language television (64% and 67%, respectively), Vietnamese radio (51%), and friends and family members (51% and 63%, respectively). We found that sources of health information varied significantly among sociodemographic subgroups of the Vietnamese male population. Sources of health information among Vietnamese American men differ considerably from other racial/ethnic groups. Research findings should be used to guide the development of health education interventions for Vietnamese men and subgroups within the Vietnamese male population.

Hepatitis B and liver cancer beliefs among Korean immigrants in Western Washington.

Hepatocellular cancer occurs more frequently among Koreans, Vietnamese, and Chinese than other racial/ethnic groups in the U.S. This excess risk can be attributed to high rates of chronic hepatitis B viral (HBV) infection and low rates of HBV vaccination among Asian immigrants. However, there is little available information regarding the hepatitis B knowledge, beliefs, and practices among Koreans, the fifth-largest Asian population in the U.S. This brief report summarizes results from 30 qualitative interviews and two focus groups investigating hepatitis and liver cancer prevention, behavior, and beliefs among first-generation Korean immigrant adults ages 18-64 years residing in the Seattle-Tacoma metropolitan area of Washington State. The report concludes with suggestions for future investigations to address the high rates of chronic HBV infection and hepatocellular cancer in this vulnerable population.