Genetic polymorphisms of VKORC1, CYP2C9, CYP4F2 in Bai, Tibetan Chinese

BACKGROUND

VKORC1, CYP2C9 and CYP4F2 are three critical genes associated with inter-individual variation of warfarin dose. Many dosing algorithms containing these gene polymorphisms and demographic characteristics have been set up for better use of warfarin. However, with distinct gene mutation frequencies among different ethnics, dosing algorithms differ greatly. For Chinese, related research just concentrate on Han Chinese, ignoring other Chinese ethnicities. This study aims to detect the popular polymorphisms in these three critical genes in Bai, Tibetan Chinese, to start the exploration of better use of warfarin in Chinese minorities.

METHODS

PCR-based methods were used to analyze VKORC1 3673G > A, CYP2C9*3, CYP4F2 rs2108622 C > T in Han, Bai and Tibetan Chinese.

RESULTS

The differences among the mutation frequencies of the studied genes in three ethnicities were not statistically significant. The frequency of A-allele of VKORC1 3673G > A was 92.8%, 90.2%, 90.8% in Bai, Tibetan, Han Chinese, respectively. The frequency of *3-allele in CYP2C9*3 was low in Bai (4.5%), Tibetan (2.8%) and Han Chinese (4.6%). Approximately one fourth of each ethnic had the mutant T-allele of CYP4F2 rs108622. However, Bai Chinese got statistically higher A-allele frequency of VKORC1 3673G > A than previously studied Han Chinese did.

CONCLUSIONS

Bai Chinese got significant higher A-allele frequency of VKORC1 3673G > A.

P1-08-02: Pre-Diagnosis Body Mass Index and Breast Cancer Prognosis and Survival: Report from the after Breast Cancer Pooling Project

Background: A large body of evidence dating back over 30 years suggests that obese women have poorer survival after a breast cancer (BC) diagnosis compared to non-obese women. Despite most studies supporting an association of elevated risk of overall mortality with obesity, the relationship of obesity with risk of BC recurrence, BC mortality and non-BC mortality remains unclear. Furthermore, reports suggest that the association of BMI with BC outcomes may be U or J shaped, prompting the necessity of examining underweight and more severely obese women as independent groups. We conducted a pooled investigation of pre-diagnosis BMI and BC recurrence and survival using data from the After Breast Cancer Pooling Project (ABCPP). Materials and Methods: The ABCPP includes 14,950 BC survivors from four prospective cohorts (three US and one Shanghai, China) diagnosed from 1990–2006 with invasive primary AJCC Stage I-III BC at ages 20–83 years. A random effects meta-analysis was conducted to assess heterogeneity across studies and poolability of data. Delayed entry Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the associations of pre-diagnosis BMI (underweight <18.5 kg/m2, normal 18.5-<25 kg/m2, overweight 25-<30 kg/m2, obese ≥30 kg/m2) with BC recurrence, BC death, non-BC death, and overall death, adjusted for age at diagnosis, stage, race/ethnicity, menopausal status, hormone receptor status, number of positive lymph nodes, treatment, smoking history, and comorbidity (diabetes, hypertension, and/or CVD). Subgroup analyses further divided the obesity group into obese (30-<35 kg/m2), severely obese (35-<40 kg/m2), and morbidly obese (≥40 kg/m2) categories.

Results: No heterogeneity in effect estimates by study was found. 2104 deaths (1416 BC-related) and 2320 recurrences were observed after a mean (SD) of 7.66 (3.95) years of follow-up. Both underweight and obese women had a statistically significant increased risk of overall death compared to normal-weight women (underweight HR=1.69; 95% CI: 1.25, 2.28 and obese HR=1.22; 95% CI: 1.08, 1.38; p for nonlinear association<0.01). Similar associations were found for non-BC death. Obese but not underweight was associated with increased risk of BC death (HR=1.17; 95% CI: 1.01, 1.36) and recurrence (HR=1.11; 95% CI: 0.98, 1.26). When examining finer obesity categories, the morbidly obese women had the greatest risk for all outcomes (overall death HR=1.90; 95% CI: 1.48, 2.45; non-BC death HR= 3.27; 95% CI: 2.25, 4.77; BC death HR = 1.47; 95% CI: 1.05, 2.06; recurrence HR = 1.27; 95% CI: 0.95, 1.71). No effect modification was observed by menopausal status, hormone receptor status, chemotherapy, and smoking. In all analyses, overweight women had similar risk of outcomes compared to normal-weight women.

Discussion: In this large pooling study of nearly 15,000 BC survivors, we found that the association between BMI and BC outcomes, specifically overall death and non-BC death, was U shaped with both underweight and obese women at greatest risk. Morbidly obese women were at even greater risk compared to other obesity groups. Maintaining a healthy weight throughout adult life may be beneficial for BC prognosis and survival.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-08-02.

Brain infarction as the initial presentation of primary posterior mediastinal seminoma

A 40-year-old man was admitted with acute onset of slurred speech and right hemiparesis. Cerebral infarction was diagnosed from magnetic resonance (MR) images. Chest X-ray incidentally revealed a posterior mediastinal tumour, which proved to be seminoma on CT-guided biopsy. The patient then received chemotherapy. Five months later, right upper limb weakness and slurred speech occurred again. Brain MR images revealed two metastatic lesions in the prior infarct areas, which on histology proved to be metastatic seminoma.

Cooperative RNP assembly: complementary rescue of structural defects by protein and RNA subunits of archaeal RNase P

Ribonuclease P (RNase P) is a ribonucleoprotein complex that utilizes a Mg(2+)-dependent RNA catalyst to cleave the 5' leader of precursor tRNAs (pre-tRNAs) and generate mature tRNAs. The bacterial RNase P protein (RPP) aids RNase P RNA (RPR) catalysis by promoting substrate binding, Mg(2+) coordination and product release. Archaeal RNase P comprises an RPR and at least four RPPs, which have eukaryal homologs and function as two binary complexes (POP5·RPP30 and RPP21·RPP29). Here, we employed a previously characterized substrate-enzyme conjugate [pre-tRNA(Tyr)-Methanocaldococcus jannaschii (Mja) RPR] to investigate the functional role of a universally conserved uridine in a bulge-helix structure in archaeal RPRs. Deletion of this bulged uridine resulted in an 80-fold decrease in the self-cleavage rate of pre-tRNA(Tyr)-MjaΔU RPR compared to the wild type, and this defect was partially ameliorated upon addition of either RPP pair. The catalytic defect in the archaeal mutant RPR mirrors that reported in a bacterial RPR and highlights a parallel in their active sites. Furthermore, an N-terminal deletion mutant of Pyrococcus furiosus (Pfu) RPP29 that is defective in assembling with its binary partner RPP21, as assessed by isothermal titration calorimetry and NMR spectroscopy, is functional when reconstituted with the cognate Pfu RPR. Collectively, these results indicate that archaeal RPPs are able to compensate for structural defects in their cognate RPR and vice-versa, and provide striking examples of the cooperative subunit interactions critical for driving archaeal RNase P toward its functional conformation.

[Critical research issues in nursing policy and management: a healthcare system perspective]

This study explores critical research issues in nursing policy and management in Taiwan from a healthcare system perspective that considers resources, programmes and organisations, service delivery, policy and management, and economic support. Findings suggest the following: In terms of resources, priority issues include quantity planning, active surveillance, planning methodology, and estimation of work life expectancies for nursing manpower. In terms of programmes ÷ organisations and delivery, priority issues include skill mix, task shifting, nationwide nursing work surveys, and nursing manpower structure and utilization. In terms of policy/management and economic support, priority issues included minimum nursing manpower requirements by law or medical institution standards and the relationship between the social insurance payment system and development of the nursing profession. The last section of this paper makes suggestions on practical ways to improve nursing policy and management research in Taiwan.

Visible light responsive photocatalyst induces progressive and apical-terminus preferential damages on Escherichia coli surfaces

Background

Recent research shows that visible-light responsive photocatalysts have potential usage in antimicrobial applications. However, the dynamic changes in the damage to photocatalyzed bacteria remain unclear.

Methodology/Principal Findings

Facilitated by atomic force microscopy, this study analyzes the visible-light driven photocatalyst-mediated damage of Escherichia coli. Results show that antibacterial properties are associated with the appearance of hole-like structures on the bacteria surfaces. Unexpectedly, these hole-like structures were preferentially induced at the apical terminus of rod shaped E. coli cells. Differentiating the damages into various levels and analyzing the percentage of damage to the cells showed that photocatalysis was likely to elicit sequential damages in E. coli cells. The process began with changing the surface properties on bacterial cells, as indicated in surface roughness measurements using atomic force microscopy, and holes then formed at the apical terminus of the cells. The holes were then subsequently enlarged until the cells were totally transformed into a flattened shape. Parallel experiments indicated that photocatalysis-induced bacterial protein leakage is associated with the progression of hole-like damages, further suggesting pore formation. Control experiments using ultraviolet light responsive titanium-dioxide substrates also obtained similar observations, suggesting that this is a general phenomenon of E. coli in response to photocatalysis.

Conclusion/Significance

The photocatalysis-mediated localization-preferential damage to E. coli cells reveals the weak points of the bacteria. This might facilitate the investigation of antibacterial mechanism of the photocatalysis.

Formation of Ge quantum dots array in layer-cake technique for advanced photovoltaics

We report a simple and manageable growth method for placing dense three-dimensional Ge quantum dot (QD) arrays in a uniform or a graded size distribution, based on thermally oxidizing stacked poly-SiGe in a layer-cake technique. The QD size and spatial density in each stack can be modulated by conditions of the Ge content in poly-Si(1-x)Ge(x), oxidation, and the underlay buffer layer. Size-dependent internal structure, strain, and photoluminescence properties of Ge QDs are systematically investigated. Optimization of the processing conditions could be carried out for producing dense Ge QD arrays to maximize photovoltaic efficiency.

Nonemergent emergency department visits under the National Health Insurance in Taiwan

OBJECTIVES

To explore the magnitude of nonemergent emergency department visits under the Taiwan National Health Insurance program and to identify significant factors associated with these visits.

METHODS

A cross-sectional analysis of the 2002 Taiwan National Health Insurance Research Database was used to identify nonemergent emergency department conditions according to the New York University algorithm. The data contained 43,384 visits, of which 83.89% could be classified. Multivariate logistic regression identified individual and contextual factors associated with nonemergent emergency department visits.

RESULTS

Nearly 15% of all emergency department visits were nonemergent; an additional 20% were emergent-preventable with primary care. Patients likely to make nonemergent emergency department visits were older, female, categorized as a Taiwan National Health Insurance Category IV beneficiary, and without major illness. Hospital accreditation level, teaching status, and location were associated with an increased likelihood of nonemergent emergency department visits.

CONCLUSION

Understanding the factors leading to nonemergent emergency department visits can assist in evaluating the overall quality of a health care system and help reduce the use of the emergency department for nonemergent conditions. Policy makers desiring cost-effective care should assess emergency department visit rates in light of available resources for specific populations.

[Effect of nurse staffing on patient outcomes: a review of the literature]

Staff shortages present nurses with ever increasing levels of stress and working hours. This has resulted in a corresponding increase in talent flight away from the nursing profession. Responding to financial constraints imposed by the Bureau of National Health Insurance (NHI), Taiwan hospitals have reduced nursing staff numbers and recruited nurses at lower levels of competencies and experience. However, few studies have explored the impact of nurse staffing on patient outcomes in Taiwan. Accordingly, we review relevant literature on nurse classifications, the current status of Taiwan nursing manpower, Taiwan and other national regulations on nursing staffing, and the impact of nursing staffing on patient outcomes in an effort to facilitate future study. Our literature review demonstrated that insufficient nursing staffing relates significantly to rates of nosocomial infections, patient mortality, patient falls, pressure ulcers, and rates of patient and family satisfaction. Insufficient nurse staffing leads to increases in adverse patient events, prolonged average hospital stay lengths, and total healthcare expenditures. Evidence shows that nurse staffing is closely linked to patient outcomes.

Pricing-out effect from possible user-fee policies under Taiwan's National Health Insurance

This article simulates the pricing-out effect due to various user-fee policies under Taiwan's National Health Insurance. Our simulation results indicate that the lower income group is more likely to be priced out of the healthcare system than the higher income group. On average, pricing-out effects are 0.04, 0.21, 0.52 and 0.73% of total beneficiaries with respect to the new co-payment policy, the catastrophic insurance policy, the under insurance policy, and the case of no National Health Insurance, respectively. We caution that a reduction of healthcare utilization due to higher user fees could result in some patients being left behind without professional care because the pricing-out effects could be higher than the substitution effects diverting demand to other professional care alternatives.

Dissecting functional cooperation among protein subunits in archaeal RNase P, a catalytic ribonucleoprotein complex

RNase P catalyzes the Mg²⁺-dependent 5′-maturation of precursor tRNAs. Biochemical studies on the bacterial holoenzyme, composed of one catalytic RNase P RNA (RPR) and one RNase P protein (RPP), have helped understand the pleiotropic roles (including substrate/Mg²⁺ binding) by which a protein could facilitate RNA catalysis. As a model for uncovering the functional coordination among multiple proteins that aid an RNA catalyst, we use archaeal RNase P, which comprises one catalytic RPR and at least four RPPs. Exploiting our previous finding that these archaeal RPPs function as two binary RPP complexes (POP5•RPP30 and RPP21•RPP29), we prepared recombinant RPP pairs from three archaea and established interchangeability of subunits through homologous/heterologous assemblies. Our finding that archaeal POP5•RPP30 reconstituted with bacterial and organellar RPRs suggests functional overlap of this binary complex with the bacterial RPP and highlights their shared recognition of a phylogenetically-conserved RPR catalytic core, whose minimal attributes we further defined through deletion mutagenesis. Moreover, single-turnover kinetic studies revealed that while POP5•RPP30 is solely responsible for enhancing the RPR’s rate of precursor tRNA cleavage (by 60-fold), RPP21•RPP29 contributes to increased substrate affinity (by 16-fold). Collectively, these studies provide new perspectives on the functioning and evolution of an ancient, catalytic ribonucleoprotein.

Online detection of waterborne bioavailable copper by valve daily rhythms in freshwater clam Corbicula fluminea

Freshwater clam Corbicula fluminea, a surrogate species in metal toxicity testing, is a promising bioindicator of impairment in aquatic ecosystems. Little is known, however, about the relationship between clam valve daily rhythmic response and metal bioavailability related to a metal biological early warning system (BEWS) design. The purpose of this study was to link biotic ligand model (BLM)-based bioavailability and valve daily rhythm in C. fluminea to design a biomonitoring system for online in situ detection of waterborne copper (Cu). We integrated the Hill-based dose-time-response function and the fitted daily rhythm function of valve closure into a constructed programmatic mechanism. The functional presentation of the present dynamic system was completely demonstrated by employing a LabVIEW graphic control program in a personal computer. We used site-specific effect concentration causing 10% of total valve closure response (EC10) as the detection threshold to implement the proposed C. fluminea-based Cu BEWS. Here our results show that the proposed C. fluminea-based BEWS could be deliberately synthesized to online in situ transmit rapidly the information on waterborne bioavailable Cu levels under various aquatic environmental conditions through monitoring the valve daily rhythmic changes. We suggested that the developed C. fluminea-based dynamic biomonitoring system could assist in developing technically defensible site-specific water quality criteria to promote more efficient uses in water resources for protection of species health in aquatic environments.

Novel modeling concept for evaluating the effects of cadmium and copper on heterotrophic growth and lysis rates in activated sludge process

A new modeling concept to evaluate the effects of cadmium and copper on heterotrophic growth rate constant (mu(H)) and lysis rate constant (b(H)) in activated sludge was introduced. The oxygen uptake rate (OUR) was employed to measure the constants. The results indicated that the mu(H) value decreased from 4.52 to 3.26 d(-1) or by 28% when 0.7 mg L(-1) of cadmium was added. Contrarily the b(H) value increased from 0.31 to 0.35 d(-1) or by 11%. When adding 0.7 mg L(-1) of copper, the mu(H) value decreased to 2.80 d(-1) or by 38%. The b(H) value increased to 0.42 d(-1) or by 35%. After regression, the inhibitory effect was in a good agreement with non-competitive inhibition kinetic. The inhibition coefficient values for cadmium and copper were 1.82 and 1.21 mg L(-1), respectively. The relation between the b(H) values and heavy metal concentrations agreed with exponential type well. The heavy metal would enhance b(H) value. Using these data, a new kinetic model was established and used to simulate the degree of inhibition. It was evident that not only the inhibitory effect on mu(H) but also that the enhancement effect on b(H) should be considered when heavy metal presented.

Single crystalline film on glass for thin film solar cells

A simple Ge-on-glass metal-oxide-semiconductor solar cell has been demonstrated by wafer bonding and smart-cut. Since single crystalline Ge is directly bonded on glass, the crystalline substrate is not necessary. The metal-oxide-semiconductor structure can be easily fabricated without n and p dopant diffusion or implantation. The reason for low efficiency is discussed, and then the optimized structures are designed by simulation. An outstanding enhancement on efficiency can be achieved with the Si/Ge/Si structure. The best performance can be achieved by optimization of the position of the Ge layer, the thickness of the Ge layer, and the number of the Ge layers. The efficiency of the thin film Si/Ge/Si solar cell with single layer of 30-nm-thick Ge outside the depletion region reaches 15.9%, as compared to the control Si sample of 11.8%. Based on the simulation and technologies, high efficiency thin film solar cells can be demonstrated in the future.

Out-of-pocket payment for medical care under Taiwan's National Health Insurance system

The objective of this study is to estimate the amount of and factors associated with out-of-pocket (OOP) payment for medical care under Taiwan's National Health Insurance (NHI) program. This research used two methods to collect original data. The first method consisted of using a sample household survey and household diary records to collect data on OOP payment prospectively over a two-month period from a random sample of 600 households in central Taiwan. Using the individual as the unit of analysis, we obtained a total of 1062 sample subjects. To ascertain the quality and accuracy of survey data, the claim records of the bureau of NHI were merged with the survey data. These data were analyzed by a two-part model, with a probit model for use of health care and an ordinary least-squares model for OOP payments. Results of this research indicate that on average an individual's annual OOP payment for medical care was euro 247, which is substantial, compared with the average euro 144 for per capita NHI earmarked tax. Finally, results of model estimation indicate that supplemental health insurance and household income were positively associated with any use of health care, while household income was also positively associated with OOP payment for health care.

Characterization of viscoelastic properties of normal and osteoarthritic chondrocytes in experimental rabbit model

The goal of this study was to characterize the changes of the viscoelastic properties of rabbit chondrocytes from normal and osteoarthritic cartilage. All samples were harvested from rabbit articular cartilage with the same age, sex, body weight, breed and osteoarthritic degree. Anterior cruciate ligament transection was utilized to induce rabbit osteoarthritic model. Micropipette aspiration technique coupled with a viscoelastic model was used to characterize viscoelastic properties of rabbit chondrocytes. The present results indicate that the viscoelastic behaviors of osteoarthritic chondrocytes have decreased during the progress of osteoarthritis and exhibited a significantly lower equilibrium modulus, instantaneous modulus and apparent viscosity (E( proportional, variant)=0.39+/-0.14 kPa, E(0)=0.68+/-0.27 kPa, mu=0.39+/-0.14 kPa.s, n=67) compared with normal chondrocytes (E( proportional, variant)=0.55+/-0.11 kPa, E(0)=0.98+/-0.14 kPa, mu=6.36+/-1.12 kPa.s, n=52) (p<0.0001). These findings may be relevant for chondrocyte-based cartilage tissue engineering.

Effect of hyperbaric oxygen on patients with traumatic brain injury

Hyperbaric oxygen therapy (HBOT) is the medical therapeutic use of oxygen at a higher atmospheric pressure. The United States Food and Drug Administration have approved several clinical applications for HBOT, but HBOT in traumatic brain injury (TBI) patients has still remained in controversial. The purpose of our study is to evaluate the benefit of HBOT on the prognosis of subacute TBI patients. We prospectively enrolled 44 patients with TBI from November 1, 2004 to October 31, 2005. The study group randomly included 22 patients who received HBOT after the patients' condition stabilization, and the other 22 corresponding condition patients were assigned into the matched control group who were not treated with HBOT. The clinical conditions of the patients were evaluated with the Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS) before and 3 to 6 months after HBOT. The GCS of the HBOT group was improved from 11.1 to 13.5 in average, and from 10.4 to 11.5 (p < 0.05) for control group. Among those patients with GOS = 4 before the HBOT, significant GOS improvement was observed in the HBOT group 6 months after HBOT. Based on this study, HBOT can provide some benefits for the subacute TBI patients with minimal adverse side effects.

Rb is critical in a mammalian tissue stem cell population

The inactivation of the retinoblastoma (Rb) tumor suppressor gene in mice results in ectopic proliferation, apoptosis, and impaired differentiation in extraembryonic, neural, and erythroid lineages, culminating in fetal death by embryonic day 15.5 (E15.5). Here we show that the specific loss of Rb in trophoblast stem (TS) cells, but not in trophoblast derivatives, leads to an overexpansion of trophoblasts, a disruption of placental architecture, and fetal death by E15.5. Despite profound placental abnormalities, fetal tissues appeared remarkably normal, suggesting that the full manifestation of fetal phenotypes requires the loss of Rb in both extraembryonic and fetal tissues. Loss of Rb resulted in an increase of E2f3 expression, and the combined ablation of Rb and E2f3 significantly suppressed Rb mutant phenotypes. This rescue appears to be cell autonomous since the inactivation of Rb and E2f3 in TS cells restored placental development and extended the life of embryos to E17.5. Taken together, these results demonstrate that loss of Rb in TS cells is the defining event causing lethality of Rb(-/-) embryos and reveal the convergence of extraembryonic and fetal functions of Rb in neural and erythroid development. We conclude that the Rb pathway plays a critical role in the maintenance of a mammalian stem cell population.