Validity of self-reported hypertension and associated factors among Vietnamese adults: a cross-sectional study.

BACKGROUND: This study aims to determine the validity of self-reported hypertension and identify factors affecting the disagreement between self-reported hypertension and objective measures of blood pressure among adults in Vietnam. MATERIALS AND METHODS: A total of 4,219 people aged 18 and older reported their hypertension status and had their blood pressure measured. The inter-reliability between self-reported and measured hypertension was assessed using Cohen's Kappa statistics. Univariate and multivariate logistic regressions were used to examine the affecting factors of disagreement. RESULT: Self-reported hypertension prevalence was 13.2% (557/4,219), while measured hypertension was 20.9% (881/4,219). An agreement between self-reported and measured data was moderate for the hypertension of participants (κ = 0.39, 95% CI 0.36-0.43). Self-reported hypertension showed high specificity (93.9%) (95% CI 93.0-94.7) but low sensitivity (40.1%; 95 CI 36.8-43.4). The percentage of disagreement in hypertension (number of false positives and false negatives between self-reported and measured data) among adults in Vietnam was 17.3%. CONCLUSION: Our findings showed there was a high disagreement percentage of hypertension between self-reported and measured data. This is the first report of this issue to warn of health risks if high blood pressure is not detected early. The disagreement of hypertension was observed more frequently in men, people older than 40, minority ethnic groups, farmers, and people with a BMI greater than 25 kg/m2.

Researchers often ask people to answer questions about their own health problems, such as high blood pressure, to study the effects of these conditions. People often provide self-reported information in response to this inquiry. However, this information might not be accurate. Therefore, it is preferable to use biological data, which involves having blood pressure checked by a machine.In this study, the self-reported hypertension of adults in Vietnam was compared to measured blood pressure data. We found that, whereas only 13.2% of respondents reported having high blood pressure, the measured blood pressure by machine revealed that 20.9% of respondents had the condition. The study also discovered that some elements, including age, gender, ethnicity, BMI, smoking status, and drinking, were associated with the discrepancy between self-reported and measured hypertension among participants.This study demonstrates that it is unreliable to estimate the prevalence of high blood pressure in Vietnam using self-reported data. According to the study, including biological tests in social surveys can increase data accuracy and clarify societal health disparities. The study suggests that to avoid and identify these health issues early, people should obtain more health education and undergo routine physicals.

Evidence of widespread endemic populations of highly multidrug resistant Klebsiella pneumoniae in hospital settings in Hanoi, Vietnam: a prospective cohort study.

BACKGROUND: Patients with prolonged hospitalisation have a significant risk of carriage of and subsequent infection with extended spectrum ß-lactamase (ESBL)-producing and carbapenemase-producing Klebsiella pneumoniae. However, the distinctive roles of the community and hospital environments in the transmission of ESBL-producing or carbapenemase-producing K pneumoniae remain elusive. We aimed to investigate the prevalence and transmission of K pneumoniae within and between the two tertiary hospitals in Hanoi, Viet Nam, using whole-genome sequencing. METHODS: We did a prospective cohort study of 69 patients in intensive care units (ICUs) from two hospitals in Hanoi, Viet Nam. Patients were included if they were aged 18 years or older, admitted for longer than the mean length of stay in their ICU, and cultured K pneumoniae from their clinical samples. Longitudinally collected samples from patients (collected weekly) and the ICU environment (collected monthly) were cultured on selective media, and whole-genome sequences from K pneumoniae colonies analysed. We did phylogenetic analyses and correlated phenotypic antimicrobial susceptibility testing with genotypic features of K pneumoniae isolates. We constructed transmission networks of patient samples, relating ICU admission times and locations with genetic similarity of infecting K pneumoniae. FINDINGS: Between June 1, 2017, and Jan 31, 2018, 69 patients were in the ICUs and eligible for inclusion, and a total of 357 K pneumoniae isolates were cultured and successfully sequenced. 228 (64%) of K pneumoniae isolates carried between two and four different ESBL-encoding and carbapenemase-encoding genes, with 164 (46%) isolates carrying genes encoding both, with high minimum inhibitory concentrations. We found a novel co-occurrence of blaKPC-2 and blaNDM-1 in 46·6% of samples from the globally successful ST15 lineage. Despite being physically and clinically separated, the two hospitals shared closely related strains carrying the same array of antimicrobial resistance genes. INTERPRETATION: These results highlight the high prevalence of ESBL-positive carbapenem-resistant K pneumoniae in ICUs in Viet Nam. Through studying K pneumoniae ST15 in detail, we showed how important resistance genes are contained within these strains that are carried broadly by patients entering the two hospitals directly or through referral. FUNDING: Medical Research Council Newton Fund, Ministry of Science and Technology, Wellcome Trust, Academy of Medical Sciences, Health Foundation, and National Institute for Health and Care Research Cambridge Biomedical Research Centre.

Genomic characterisation of multidrug-resistant Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii in two intensive care units in Hanoi, Viet Nam: a prospective observational cohort study.

BACKGROUND: Viet Nam has high rates of antimicrobial resistance (AMR) but little capacity for genomic surveillance. This study used whole genome sequencing to examine the prevalence and transmission of three key AMR pathogens in two intensive care units (ICUs) in Hanoi, Viet Nam. METHODS: A prospective surveillance study of all adults admitted to ICUs at the National Hospital for Tropical Diseases and Bach Mai Hospital was done between June 19, 2017, and Jan 16, 2018. Clinical and environmental samples were cultured on selective media, characterised with MALDI TOF mass spectrometry, and sequenced with Illumina. Phylogenies based on the de-novo assemblies (SPAdes) were constructed with MAFFT (PARsnp), Gubbins, and RAxML. Resistance genes were detected with Abricate against the US National Center for Biotechnology Information database. FINDINGS: 3153 Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii isolates from 369 patients were analysed. Phylogenetic analysis revealed predominant lineages within A baumannii (global clone 2, sequence types ST2 and ST571) and K pneumoniae (ST15, ST16, ST656, ST11, and ST147) isolates. Isolation from stool was most common with E coli (87·0%) followed by K pneumoniae (62·5%). Of the E coli, 85·0% carried a blaCTX-M variant, while 81·8% of K pneumoniae isolates carried blaNDM (54·4%), or blaKPC (45·1%), or both. Transmission analysis with single nucleotide polymorphisms identified 167 clusters involving 251 (68%) of 369 patients, in some cases involving patients from both ICUs. There were no clear differences between the lineages or AMR genes recovered between the two ICUs. INTERPRETATION: This study represents the largest prospective surveillance study of key AMR pathogens in Vietnamese ICUs. Clusters of closely related isolates in patients across both ICUs suggests recent transmission before ICU admission in other health-care settings or in the community. FUNDING: UK Medical Research Council Newton Fund, Viet Nam Ministry of Science and Technology, Wellcome Trust, Academy of Medical Sciences, Health Foundation, and UK National Institute for Health and Care Research Cambridge Biomedical Research Centre.

Systematic Surveillance of Rickettsial Diseases in 27 Hospitals from 26 Provinces throughout Vietnam.

In Vietnam, the public health burden of rickettsial infections continues to be underestimated due to knowledge gaps in the epidemiology of these diseases. We conducted a systematic study among 27 hospitals from 26 provinces in eight ecological regions throughout Vietnam to investigate the prevalence, distribution, and clinical characteristics of rickettsial diseases. We recruited 1834 patients in the study from April 2018 to October 2019. The findings showed that rickettsial diseases were common among undifferentiated febrile patients, with 564 (30.8%) patients positive by qPCR for scrub typhus, murine typhus or spotted fever. Scrub typhus (484, 85.8%) was the most common rickettsial disease, followed by murine typhus (67, 11.9%) and spotted fever (10, 1.8%). Rickettsial diseases were widely distributed in all regions of Vietnam and presented with nonspecific clinical manifestations.

Epidemic Surveillance Models for Containing the Spread of SARS-CoV-2 Variants: Taiwan Experience

ObjectivesTwo kinds of epidemic surveillance models are presented for containing the spread of SARS-CoV-2 variants so as to avert and stamp out a community-acquired outbreak (CAO) with non-pharmaceutical interventions (NPIs), tests, and vaccination. DesignThe surveillance of domestic cluster infections transmitted from imported cases with one-week time lag assessed by the Poisson model and the surveillance of whether, how and when NPIs and test contained the CAO with the SEIR model. SettingsBorder and Community of Taiwan. Main Outcome MeasurementsThe expected number and the upper bound of the 95% credible interval (CrI) of weekly covid-19 cases compared with the observed number for assessing the threshold of a CAO; effective reproductive number (Rt) and the effectiveness of NPIs for containing a CAO. ResultsFor the period of January-September 2020 when the wild type and the D614G period were prevailing, an increase in one imported case prior to one week would lead to 9.54% (95% CrI 6.44% to 12.59%) higher risk of domestic cluster infection that provides a one-week prior alert signal for more stringent NPIs and active testing locally. Accordingly, there was an absence of CAO until the Alpha VOC period of February 2021. However, given level one of NPI alert the risk of domestic cluster infections was gradually elevated to 14.14% (95% CrI 5.41% to 25.10%), leading to the Alpha VOC CAOs of six hotspots around mid-May 2021. It took two-and-half months for containing this CAO mainly with level three of NPI alert and rapid test and partially by the rolling out of vaccination. By applying the SEIR model, the Rt decreased from 4.0 at beginning to 0.7 on 31 July 2021 in parallel with the escalating NPIs from 30% to 90%. Containing a small outbreak of Delta VOC during this CAO period was also evaluated and demonstrated. After controlling the CAO, it again returned to imported-domestic transmission for Delta VOC from July until September 2021, giving an estimate of 10.16% (95% CrI: 7.01% to 13.59%) for the risk of several small cluster infections. However, there was an absence of CAO that resulted from the effectiveness of NPIs and tests, and the rapid expansion of vaccination. ConclusionsAverting and containing CAOs of SARS-CoV-2 variants are demonstrated by two kinds of epidemic surveillance models that have been applied to Taiwan scenario. These two models can be accommodated to monitor the epidemic of forthcoming emerging SARS-CoV-2 VOCs with various circumstances of vaccine coverage, NPIs, and tests in countries worldwide.

Viral Metagenomic Analysis of Cerebrospinal Fluid from Patients with Acute Central Nervous System Infections of Unknown Origin, Vietnam.

Central nervous system (CNS) infection is a serious neurologic condition, although the etiology remains unknown in >50% of patients. We used metagenomic next-generation sequencing to detect viruses in 204 cerebrospinal fluid (CSF) samples from patients with acute CNS infection who were enrolled from Vietnam hospitals during 2012-2016. We detected 8 viral species in 107/204 (52.4%) of CSF samples. After virus-specific PCR confirmation, the detection rate was lowered to 30/204 (14.7%). Enteroviruses were the most common viruses detected (n = 23), followed by hepatitis B virus (3), HIV (2), molluscum contagiosum virus (1), and gemycircularvirus (1). Analysis of enterovirus sequences revealed the predominance of echovirus 30 (9). Phylogenetically, the echovirus 30 strains belonged to genogroup V and VIIb. Our results expanded knowledge about the clinical burden of enterovirus in Vietnam and underscore the challenges of identifying a plausible viral pathogen in CSF of patients with CNS infections.

The Virome of Acute Respiratory Diseases in Individuals at Risk of Zoonotic Infections.

The ongoing coronavirus disease 2019 (COVID-19) pandemic emphasizes the need to actively study the virome of unexplained respiratory diseases. We performed viral metagenomic next-generation sequencing (mNGS) analysis of 91 nasal-throat swabs from individuals working with animals and with acute respiratory diseases. Fifteen virus RT-PCR-positive samples were included as controls, while the other 76 samples were RT-PCR negative for a wide panel of respiratory pathogens. Eukaryotic viruses detected by mNGS were then screened by PCR (using primers based on mNGS-derived contigs) in all samples to compare viral detection by mNGS versus PCR and assess the utility of mNGS in routine diagnostics. mNGS identified expected human rhinoviruses, enteroviruses, influenza A virus, coronavirus OC43, and respiratory syncytial virus (RSV) A in 13 of 15 (86.7%) positive control samples. Additionally, rotavirus, torque teno virus, human papillomavirus, human betaherpesvirus 7, cyclovirus, vientovirus, gemycircularvirus, and statovirus were identified through mNGS. Notably, complete genomes of novel cyclovirus, gemycircularvirus, and statovirus were genetically characterized. Using PCR screening, the novel cyclovirus was additionally detected in 5 and the novel gemycircularvirus in 12 of the remaining samples included for mNGS analysis. Our studies therefore provide pioneering data of the virome of acute-respiratory diseases from individuals at risk of zoonotic infections. The mNGS protocol/pipeline applied here is sensitive for the detection of a variety of viruses, including novel ones. More frequent detections of the novel viruses by PCR than by mNGS on the same samples suggests that PCR remains the most sensitive diagnostic test for viruses whose genomes are known. The detection of novel viruses expands our understanding of the respiratory virome of animal-exposed humans and warrant further studies.

Pig Exposure and Health Outcomes in Hospitalized Infectious Disease Patients in Vietnam.

Many infectious diseases have a zoonotic origin, and several have had major public health implications. Contact with animals is a known risk factor for zoonotic infections, although there are limited data on disease symptoms and pathogens associated with contact with different animal species. The rise in pig production in Southeast Asia has contributed to the emergence and re-emergence of zoonotic infections caused by contact with pigs and pig products. To compare the symptom and pathogen profiles of hospitalized patients with and without pig contact, we collected data on disease symptoms, infecting pathogens, and animal contact behaviour from patients attending six hospitals across Vietnam between 2012 and 2016. Patients who had previous contact with pigs were more likely to have enteric disease than respiratory or central nervous system infections and were more likely to grow Escherichia coli and Shigella from stool culture than those without pig contact. Patients with enteric infections who kept pigs were also more likely to have a disease of unknown origin. Public health initiatives that account for differences in animal contact behaviours and offer more comprehensive diagnostics in high-risk individuals are needed if emergence and re-emergence of zoonotic disease is to be monitored and prevented.

Analysis of the 56-kDa type specific antigen gene of Orientia tsutsugamushi from northern Vietnam.

Scrub typhus has been documented since 1932 in Vietnam, however, the disease burden of scrub typhus remains poorly understood in the country. We conducted this study to describe the phylogenetic analysis of the 56-kDa type-specific antigen (TSA) gene of Orientia tsutsugamushi associated with PCR positive cases of scrub typhus. Of 116 positive samples, 65 type-specific antigen gene sequences were obtained and classified into 3 genogroups: Karp, Kato and Gilliam. The Karp genogroup was the most frequently detected phylogenetic cluster in the study with 30 samples (46%), followed by Kato and Gilliam with 20 (31%) and 15 (23%), respectively. All sequences showed 94-100% nucleotide similarity to reference sequences collected in the central part of Vietnam in 2017. Patients infected with Karp genogroup were more likely to have significant thrombocytopenia than the other genogroups. These results suggest that any scrub typhus vaccine considered for use in Vietnam should provide protection against each of these 3 genogroups.

Clinical Manifestations and Molecular Diagnosis of Scrub Typhus and Murine Typhus, Vietnam, 2015-2017.

Rickettsioses are endemic to Vietnam; however, only a limited number of clinical studies have been performed on these vectorborne bacteria. We conducted a prospective hospital-based study at 2 national referral hospitals in Hanoi to describe the clinical characteristics of scrub typhus and murine typhus in northern Vietnam and to assess the diagnostic applicability of quantitative real-time PCR assays to diagnose rickettsial diseases. We enrolled 302 patients with acute undifferentiated fever and clinically suspected rickettsiosis during March 2015-March 2017. We used a standardized case report form to collect clinical information and laboratory results at the time of admission and during treatment. We confirmed scrub typhus in 103 (34.1%) patients and murine typhus in 12 (3.3%) patients. These results highlight the need for increased emphasis on training for healthcare providers for earlier recognition, prevention, and treatment of rickettsial diseases in Vietnam.

Enterovirus D68 in Viet Nam (2009-2015).

BACKGROUND: Since 1962, enterovirus D68 (EV-D68) has been implicated in multiple outbreaks and sporadic cases of respiratory infection worldwide, but especially in the USA and Europe with an increasing frequency between 2010 and 2014. We describe the detection, associated clinical features and molecular characterization of EV-D68 in central and southern Viet Nam between 2009 and 2015. METHODS: Enterovirus/rhinovirus PCR positive respiratory or CSF samples taken from children and adults with respiratory/central nervous system infections in Viet Nam were tested by an EV-D68 specific PCR. The included samples were derived from 3 different observational studies conducted at referral hospitals across central and southern Viet Nam between 2009 and 2015. Whole-genome sequencing was carried out using a MiSeq based approach. Phylogenetic reconstruction and estimation of evolutionary rate and recombination were carried out in BEAST and Recombination Detection Program, respectively. RESULTS: EV-D68 was detected in 21/625 (3.4%) enterovirus/rhinovirus PCR positive respiratory samples but in none of the 15 CSF. All the EV-D68 patients were young children (age range: 11.8 - 24.5 months) and had moderate respiratory infections. Phylogenetic analysis suggested that the Vietnamese sequences clustered with those from Asian countries, of which 9 fell in the B1 clade, and the remaining sequence was identified within the A2 clade. One intra sub-clade recombination event was detected, representing the second reported recombination within EV-D68. The evolutionary rate of EV-D68 was estimated to be 5.12E -3 substitutions/site/year. Phylogenetic analysis indicated that the virus was imported into Viet Nam in 2008. CONCLUSIONS: We have demonstrated for the first time EV-D68 has been circulating at low levels in Viet Nam since 2008, associated with moderate acute respiratory infection in children. EV-D68 in Viet Nam is most closely related to Asian viruses, and clusters separately from recent US and European viruses that were suggested to be associated with acute flaccid paralysis.

Evaluation of the Luminex xTAG Respiratory Viral Panel FAST v2 assay for detection of multiple respiratory viral pathogens in nasal and throat swabs in Vietnam.

BACKGROUND: Acute respiratory infections (ARI) are among the leading causes of hospitalization in children ≤5 years old. Rapid diagnostics of viral pathogens is essential to avoid unnecessary antibiotic treatment, thereby slowing down antibiotic-resistance. We evaluated the diagnostic performance of the Luminex xTAG Respiratory Viral Panel FAST v2 against viral specific PCR as reference assays for ARI in Vietnam. METHODS: Four hundred and forty two nose and throat swabs were collected in viral transport medium, and were tested with Luminex xTAG Respiratory Viral Panel FAST v2. Multiplex RT-PCR and single RT-PCR were used as references.    Results: Overall, viral pathogens were detected in a total count of 270/294 (91.8%, 95% CI 88.1-94.7) by the Luminex among reference assays, whilst 112/6336 (1.8%, 95% CI, 1.4-2.1) of pathogens were detected by the Luminex, but not by reference assays. Frequency of pathogens detected by Luminex and reference assays was 379 and 292, respectively. The diagnostic yield was 66.7% (295/442, 95%CI 62.1-71.1%) for the Luminex assay and 54.1% (239/442, 95% CI, 49.3-58.8%) for reference assays. The Luminex kit had higher yields for all viruses except influenza B virus, respiratory syncytial virus, and human bocavirus. High agreements between both methods [mean (range): 0.91 (0.83-1.00)] were found for 10/15 viral agents. CONCLUSIONS: The Luminex assay is a high throughput multiplex platform for rapid detection of common viral pathogens causing ARI. Although the current high cost may prevent Luminex assays from being widely used, especially in limited resource settings where ARI are felt most, its introduction in clinical diagnostics may help reduce unnecessary use of antibiotic prescription.

Evaluation of Luminex xTAG Gastrointestinal Pathogen Panel Assay for Detection of Multiple Diarrheal Pathogens in Fecal Samples in Vietnam.

Diarrheal disease is a complex syndrome that remains a leading cause of global childhood morbidity and mortality. The diagnosis of enteric pathogens in a timely and precise manner is important for making treatment decisions and informing public health policy, but accurate diagnosis is a major challenge in industrializing countries. Multiplex molecular diagnostic techniques may represent a significant improvement over classical approaches. We evaluated the Luminex xTAG gastrointestinal pathogen panel (GPP) assay for the detection of common enteric bacterial and viral pathogens in Vietnam. Microbiological culture and real-time PCR were used as gold standards. The tests were performed on 479 stool samples collected from people admitted to the hospital for diarrheal disease throughout Vietnam. Sensitivity and specificity were calculated for the xTAG GPP for the seven principal diarrheal etiologies. The sensitivity and specificity for the xTAG GPP were >88% for Shigellaspp.,Campylobacterspp., rotavirus, norovirus genotype 1/2 (GI/GII), and adenovirus compared to those of microbiological culture and/or real-time PCR. However, the specificity was low (∼60%) for Salmonella species. Additionally, a number of important pathogens that are not identified in routine hospital procedures in this setting, such as Cryptosporidiumspp. and Clostridium difficile, were detected with the GPP. The use of the Luminex xTAG GPP for the detection of enteric pathogens in settings, like Vietnam, would dramatically improve the diagnostic accuracy and capacity of hospital laboratories, allowing for timely and appropriate therapy decisions and a wider understanding of the epidemiology of pathogens associated with severe diarrheal disease in low-resource settings.

Antibiotic residue monitoring results for pork, chicken, and beef samples in Vietnam in 2012-2013.

A monitoring plan of residual antibiotics in food of animal origin was conducted in Vietnam from 2012 to 2013. Meat samples were collected from slaughterhouses and retail stores in Ho Chi Minh City and Nha Trang. A total of 28 antibiotics were analyzed using a LC-MS/MS screening method. Sulfonamides, fluoroquinolones, and tilmicosin were detected in some of the samples. Sulfaclozine and fluoroquinolones were mainly detected in chicken samples, and sulfamethazine was mainly detected in pork samples. High levels of sulfonamide residues, ranging between 2500 and 2700 µg/kg sulfaclozine and between 1300 and 3600 µg/kg sulfamethazine, were present in two chicken and three pork samples, respectively. Tilmicosin was detected at ranges of 150-450 µg/kg in 10 chicken samples. Positive percentages were 17.3, 8.8, and 7.4% for chicken, pork, and beef, respectively, for an average of 11.9%. The results suggest an appropriate withdrawal period after drug administration had not been observed in some livestock.

Health-financing reforms in southeast Asia: challenges in achieving universal coverage.

In this sixth paper of the Series, we review health-financing reforms in seven countries in southeast Asia that have sought to reduce dependence on out-of-pocket payments, increase pooled health finance, and expand service use as steps towards universal coverage. Laos and Cambodia, both resource-poor countries, have mostly relied on donor-supported health equity funds to reach the poor, and reliable funding and appropriate identification of the eligible poor are two major challenges for nationwide expansion. For Thailand, the Philippines, Indonesia, and Vietnam, social health insurance financed by payroll tax is commonly used for formal sector employees (excluding Malaysia), with varying outcomes in terms of financial protection. Alternative payment methods have different implications for provider behaviour and financial protection. Two alternative approaches for financial protection of the non-poor outside the formal sector have emerged-contributory arrangements and tax-financed schemes-with different abilities to achieve high population coverage rapidly. Fiscal space and mobilisation of payroll contributions are both important in accelerating financial protection. Expanding coverage of good-quality services and ensuring adequate human resources are also important to achieve universal coverage. As health-financing reform is complex, institutional capacity to generate evidence and inform policy is essential and should be strengthened.

Rural health care in Vietnam and China: conflict between market reforms and social need.

China and Vietnam have adopted market reforms in the health sector in the context of market economic reforms. Vietnam has developed a large private health sector, while in China commercialization has occurred mainly in the formal public sector, where user fees are now the main source of facility finance. As a result, the integrity of China's planned health service has been disrupted, especially in poor rural areas. In Vietnam the government has been an important financer of public health facilities and the pre-reform health service is largely intact, although user fees finance an increasing share of facility expenditure. Over-servicing of patients to generate revenue occurs in both countries, but more seriously in China. In both countries government health expenditure has declined as a share of total health expenditure and total government expenditure, while out-of-pocket health spending has become the main form of health finance. This has particularly affected the rural poor, deterring them from accessing health care. Assistance for the poor to meet public-sector user fees is more beneficial and widespread in Vietnam than China. China is now criticizing the degree of commercialization of its health system and considers its health reforms "basically unsuccessful." Market reforms that stimulate growth in the economy are not appropriate to reform of social sectors such as health.

Oophorectomy and tamoxifen adjuvant therapy in premenopausal Vietnamese and Chinese women with operable breast cancer.

PURPOSE: In 1992, the Early Breast Cancer Trialists' Collaborative Group reported that a meta-analysis of six randomized trials in European and North American women begun from 1948 to 1972 demonstrated disease-free and overall survival benefit from adjuvant ovarian ablation. Approximately 350,000 new cases of breast cancer are diagnosed annually in premenopausal Asian women who have lower levels of estrogen than western women. PATIENTS AND METHODS: From 1993 to 1999, we recruited 709 premenopausal women with operable breast cancer (652 from Vietnam, 47 from China) to a randomized clinical trial of adjuvant oophorectomy and tamoxifen (20 mg orally every day) for 5 years or observation and this combined hormonal treatment on recurrence. At later dates estrogen- and progesterone-receptor protein assays by immunohistochemistry were performed for 470 of the cases (66%). RESULTS: Treatment arms were well balanced. With a median follow-up of 3.6 years, there have been 84 events and 69 deaths in the adjuvant treatment group and 127 events and 91 deaths in the observation group, with 5-year disease-free survival rates of 75% and 58% (P =.0003 unadjusted; P =.0075 adjusted), and overall survival rates of 78% and 70% (P =.041 unadjusted) for the adjuvant and observation groups, respectively. Only patients with hormone receptor-positive tumors benefited from the adjuvant treatment. In Vietnam, for women unselected for hormone receptor status, a cost-effectiveness analysis suggests that this intervention costs $350 per year of life saved. CONCLUSION: Vietnamese and Chinese women with hormone receptor-positive operable breast cancer benefit from adjuvant treatment with surgical oophorectomy and tamoxifen.

Monoamine oxidase inhibitory coumarin from Zanthoxylum schinifolium.

A methanol extract of Zanthoxylum schinifolium stems at a concentration of 250 microg/ml showed potent inhibitory activity against monoamine oxidase (MAO) in a mouse brain. Activity-guided separation and purification of the extract yielded lacinartin (1) as an active coumarin compound. Lacinartin showed significant inhibitory effects on MAO in a dose-dependent manner. The IC(50) value on MAO activity was 9.2 microM. The MAO-A (IC(50) value, 5.7 microM) sensitivity to lacinartin was greater than that of MAO-B (IC(50) value, 28.6 microM). An enzyme kinetic study revealed that lacinartin inhibited MAO activity by a non-competitive mode.