Effects of mask-wearing on treadmill exercise test

Background

Concerning about the spread of COVID-19, World Health Organization recommends wearing facemasks to minimize viral transmission. Patients are required to wear facemasks while conducting treadmill exercise tests in hospitals. The effects of mask-wearing on the results of stress exercise testing remain uncertain.

Purpose

This study aims to assess the impact of mask-wearing on the physiological parameters during treadmill exercise testing.

Methods

Patients who underwent treadmill exercise test using the Bruce protocol for the diagnosis of ischemic heart disease were retrospectively examined between 2020 and 2021. A propensity score matching was performed to adjust the baseline characteristics of patients with and without mask. Blood pressure, heart rate, exercise duration, and the interpretation of stress test were compared. The ischemic ST-segment response was defined as flat or downsloping depression of the ST seg-ment >0.1 mV below baseline and lasting longer than 0.08 second. Nondiagnostic result of treadmill exercise test was defined as absence of ischemic ST-segment response in which the 90% of maximal predicted heart rate for age and sex was not achieved.

Results

Following 1:1 propensity score matching, a total of 3,996 patients were enrolled for analysis, including 1,998 patients who performed treadmill exercise testing with masks, and 1,998 without masks. Baseline characteristics were similar between the two groups (mean age, 56.1±12.1 years; 38.7% female; mean body mass index, 25.5±3.9 kg/m²). At baseline, patients with masks had significantly higher heart rate (84.8±14.7 bpm vs. 82.5±14.0 bpm; p<0.001) and lower systolic blood pressure (130.4±19.0 mmHg vs. 132.4±18.7 mmHg; p=0.001) than those without masks. Patients with masks conducted significantly shorter duration of exercise (435±128 seconds vs. 481±133 seconds; p<0.001), achieved significantly lower measurement of peak heart rate (149.5±17.1 bpm vs. 152.7±17.0 bpm; p<0.001), and had significantly lower rate-pressure products (26,366±5,207 mmHg·bpm vs. 27,629±5,242 mmHg*bpm; p<0.001) than those without masks. The proportion of patients who were unable to complete stage II of the Bruce protocol was significantly higher among patients with masks (15.1% vs. 9.0%; p<0.001). The proportion of nondiagnostic result was significantly higher among patients with mask (12.2% vs. 8.8%; p<0.001), whereas the proportion of positive ischemic ST-segment response rate was significantly higher among patients without mask (28.1% vs. 23.3%; p=0.001).

Conclusions

Our study demonstrated that performing treadmill exercise test with mask could significantly decrease the duration of exercise, reduce the maximal achieved heart rate, decease the rate-pressure product, and thus reduce the diagnostic power of treadmill exercise testing.

Funding Acknowledgement

Type of funding sources: None.

Long-term evaluation of activated carbon as an adsorbent for biogas desulfurization

In this study, granular activated carbon (GAC) was used as an adsorbent for biogas desulfurization. Biogas containing 932-2,350 ppm of H₂S was collected from an anaerobic digester to treat the wastewater from a dairy farm with about 200 cows. An adsorption test was performed by introducing the biogas to a column that was packed with approximately 50 L of commercial GAC. The operation ceased if the effluent gas had an H₂S concentration of over 100 ppm. The GAC was replaced by a given weight of new GAC in a subsequent test. According to the results, for H₂S concentrations in the range of 932-1,560 ppm (average±SD = 1,260 ± 256 ppm), 1 kg of the GAC yielded biogas treatment capacities of 568 ± 112 m³ and H₂S adsorption capacities of 979 ± 235 g. For the higher influent H₂S concentrations of 2,110 ± 219 ppm, the biogas treatment and H₂S-adsorption capacities decreased to 229 ± 18 m³ and 668 ± 47 g, respectively. An estimation indicated a requisite cost of US$16.5 for the purification of 1,000 m³ of biogas containing 2,110 ppm of H₂S. This cost is approximately 5% of US$330, the value of 1,000 m³ of biogas.

IMPLICATIONS

Biogas generated from anaerobic digesters of animal manure and municipal wastewater sludge contains hydrogen sulfide which must be removed before it can be combusted in electricity-generation engines. This study demonstrated that commercial activated carbon adsorption can be an economical and effective approach for removing hydrogen sulfide from biogas. In this study, granular activated carbon (GAC) was used as an adsorbent for biogas desulfurization. The biogas containing 932-2,350 ppm of H₂S was collected from an anaerobic digester for treating wastewater collected from a 200 dairy farm. The adsorption test was performed by introducing the biogas to a PVC column packed with a commercial GAC of around 50 L. Operation ceased if the effluent gas had an H₂S concentration of over 100 ppm. A given weight of the new GAC was replaced for a successive test.

Abstract BS1-2: Genome regulation by long noncoding RNA genes

The discovery of extensive transcription of long noncoding RNAs (lncRNAs) provide an important new perspective on the centrality of RNA in gene regulation. I will discuss genome-scale strategies to discover and characterize lncRNAs, including RNA chemical modifications and RNA structures. LncRNAs form extensive networks of ribonucleoprotein (RNP) complexes with numerous chromatin regulators, and target these enzymatic activities to appropriate locations in the genome. Long noncoding RNAs can function as modular scaffolds to specify higher order organization in RNP complexes and in chromatin states. A new emerging theme is that DNA elements that mediate lncRNA expression can also have powerful effects in controlling chromatin neighborhoods, which alter oncogene expression and activity. The importance of these modes of regulation is underscored by the newly recognized roles of long RNAs in human diseases.

Citation Format: HY Chang. Genome regulation by long noncoding RNA genes [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr BS1-2.

Energy intake at different times of the day: Its association with elevated total and LDL cholesterol levels

BACKGROUND AND AIMS

This study examined the association between macronutrient intake at different times of the day and blood lipid levels.

METHODS AND RESULTS

The study was based on the Nutrition and Health Survey in Taiwan, a cross-sectional study of non-institutionalized and non-pregnant healthy adults (≥19-years-old). A one-day (24 h) dietary recall assessed participants' food intake. Fasting plasma triglycerides, total cholesterol, and high-density lipoprotein (HDL) cholesterol were determined. Low-density lipoprotein (LDL) cholesterol was estimated based on the Friedewald formula. According to the data of eligible subjects (n = 1283), the time of energy intake was categorized into three meal times 0500-0929 (morning), 1130-1329 (noon), and 1730-2029 (evening), along with three snack times 0930-1129 (mid-morning), 1330-1729 (afternoon), and 2030-0459 (night). Energy and macronutrient intake were calculated for the 6 time periods, based on 24 h recall data. An adjusted regression model showed that by transferring 100 kcal intake at night to the morning or noon, LDL cholesterol would be lower by 1.46 (95% CI: 2.42-0.50) and 1.27 mg/dL (95% CI: 2.24-0.30), respectively. Transferring 100 kcal of fat intake at night to earlier periods was associated with a lower LDL cholesterol level, especially transferring to noontime (significantly lower by 5.21 mg/dL, 95% CI: [7.42-2.99]) and evening (significantly lower by 3.19 mg/dL, 95% CI: [6.29-0.08]).

CONCLUSIONS

Total cholesterol and LDL cholesterol had the same pattern of association with the timing of energy intake. The study showed that elevated total and LDL cholesterol were positively associated with nighttime energy and fat intake.

Overexpression of miR-101-2 in donor cells improves the early development of Holstein cow somatic cell nuclear transfer embryos

Accumulating studies have suggested that microRNA play a part in regulating multiple cellular processes, such as cell proliferation, apoptosis, the cell cycle, and embryo development. This study explored the effects of miR-101-2 on donor cell physiological status and the development of Holstein cow somatic cell nuclear transfer (SCNT) embryos in vitro. Holstein cow bovine fetal fibroblasts (BFF) overexpressing miR-101-2 were used as donor cells to perform SCNT; then, cleavage rate, blastocyst rate, inner cell mass-to-trophectoderm ratio, and the expression of some development- and apoptosis-related genes in different groups were analyzed. The miR-101-2 suppressed the expression of inhibitor of growth protein 3 (ING3) at mRNA and protein levels, expedited cell proliferation, and decreased apoptosis in BFF, suggesting that ING3, a target gene of miR-101-2, is a potential player in this process. Moreover, by utilizing donor cells overexpressing miR-101-2, the development of bovine SCNT embryos in vitro was significantly enhanced; the apoptotic rate in SCNT blastocysts was reduced, and the inner cell mass-to-trophectoderm ratio and SOX2, POU5F1, and BCL2L1 expression significantly increased, whereas BAX and ING3 expression decreased. Collectively, these findings suggest that miR-101-2 promotes BFF proliferation and vitality, reduces their apoptosis, and improves the early development of SCNT embryos.

A Point-based Mortality Prediction System for Older Adults with Diabetes

The mortality prediction models for the general diabetic population have been well established, but the corresponding elderly-specific model is still lacking. This study aims to develop a mortality prediction model for the elderly with diabetes. The data used for model establishment were derived from the nationwide adult health screening program in Taiwan in 2007-2010, from which we applied a 10-fold cross-validation method for model construction and internal validation. The external validation was tested on the MJ health screening database collected in 2004-2007. Multivariable Cox proportional hazards models were used to predict five-year mortality for diabetic patients ≥65 years. A total of 220,832 older subjects with diabetes were selected for model construction, of whom 23,241 (10.5%) died by the end of follow-up (December 31, 2011). The significant predictors retained in the final model included age, gender, smoking status, body mass index (BMI), fasting glucose, systolic and diastolic blood pressure, leukocyte count, liver and renal function, total cholesterol, hemoglobin, albumin, and uric acid. The Harrell's C in the development, internal-, and external-validation datasets were 0.737, 0.746, and 0.685, respectively. We established an easy-to-use point-based model that could accurately predict five-year mortality risk in older adults with diabetes.

Interpenetration of CH3NH3PbI3 and TiO2 improves perovskite solar cells while TiO2 expansion leads to degradation

Perovskite solar cells have drawn much attention and achieved efficiencies over 22%, but relatively little is known about the long-term stability under photovoltaic operation. So far, stability studies have reported about the importance of degradation of each layer, but little to no consideration has been given to the whole device architecture. We investigated the stability of perovskite solar cells in order to fundamentally understand the mechanism behind efficiency improvement/degradation during device operation. We found that during operation the interfaces of the perovskite and the electron-transport layer (ETL), meso-porous TiO₂, further intermix with each other, which leads to improved power conversion efficiency (PCE) during the initial operation of these solar cells. The operation-induced structural changes are examined directly by X-ray photoelectron spectroscopy (XPS) with in situ low-energy Ar⁺ sputtering and time-of-flight secondary ion mass spectrometry (ToF-SIMS) with C₆₀ sputtering. In addition, this study describes that the primary cause of irreversible degradation during operation is due to the expansion of TiO₂ and ion migration throughout the perovskite solar cell.

Has Choosing Wisely® affected rates of dual-energy X-ray absorptiometry use?

Reducing overuse of tests such as dual-energy X-ray absorptiometry (DXA) scans in younger women is an important quality issue. We evaluated trends in DXA ordering before and after Choosing Wisely recommendations were released. We found no significant difference in ordering trends suggesting that other initiatives are needed to change behavior.

INTRODUCTION

Reducing overuse of tests such as dual-energy X-ray absorptiometry (DXA) scans in younger women is an important quality issue, but trends in care are difficult to change. We evaluated (1) trends in DXA ordering before and after the Choosing Wisely recommendation release and (2) patterns of key characteristics that indicate a potentially appropriate DXA scan order.

METHODS

We performed a retrospective longitudinal analysis of electronic health record data at a multi-specialty, ambulatory care network of 34 practices across Maryland and Washington, DC. Since the Choosing Wisely DXA recommendation was released April 2012, the study periods were April-December 2011 (pre-initiative) and April-December 2012 (post-initiative). Women between 50 and 64 years with primary care encounters, and primary care providers who saw ten or more women in the study population in both pre and post periods were included.

RESULTS

For 42,320 eligible patients, the mean provider ordering rate was 2.6 % pre-initiative and 2.0 % post-initiative; there was no significant difference in trend over time. Over 70 % of the population had no characteristics associated with potentially appropriate DXA ordering. Low body mass index, current smoker status, and osteopenia were the most common characteristics indicating potentially appropriate DXA orders. Patients with any of these three characteristics had DXA ordering rates between 3-20 %.

CONCLUSIONS

The trend in provider ordering rates of DXA scans did not decrease after the release of the DXA Choosing Wisely recommendation. Targeted initiatives addressing providers with high ordering rates will be needed to change behavior.

Early radiographic diagnosis of peri-implantitis enhances the outcome of peri-implantitis treatment: a 5-year retrospective study after non-surgical treatment

PURPOSE

This retrospective study evaluated the relationship between the timing of peri-implantitis diagnosis and marginal bone level after a 5-year follow-up of non-surgical peri-implantitis treatment.

METHODS

Thirty-three patients (69 implants) were given peri-implantitis diagnosis in 2008-2009 in Seoul National University Bundang Hospital. Among them, 31 implants from 16 patients were included in this study. They were treated non-surgically in this hospital, and came for regular maintenance visits for at least 5 years after peri-implantitis treatment. Radiographic marginal bone levels at each interval were measured and statistical analysis was performed.

RESULTS

Timing of peri-implantitis was one of the significant factors affecting initial bone loss and total bone loss not additional bone after peri-implantitis diagnosis. Patients with cardiovascular disease and diabetic mellitus were positively influenced on both initial bone loss and total bone loss. Patients who needed periodontal treatment after implant placement showed a negative effect on bone loss compared to those who needed periodontal treatment before implant placement during entire periods. Implant location also significantly influenced on amounts of bone loss. Mandibular implants showed less bone loss than maxillary implants. Among surgical factors, combined use of autogenous and xenogenic bone graft materials showed a negative effect on bone loss compared to autogenous bone graft materials. Use of membrane negatively affected on initial bone loss but positively on additional bone loss and total bone loss. Thread exposure showed positive effects on initial bone loss and total bone loss.

CONCLUSIONS

Early peri-implantitis diagnosis led to early non-surgical intervention for peri-implantitis treatment, which resulted in the maintenance of the bone level as well as preservation of the implant.

Association between halitosis diagnosed by a questionnaire and halimeter and symptoms of gastroesophageal reflux disease

Background/Aims

The relationship between halitosis and gastroesophageal reflux disease (GERD) remains controversial. The aim of this study was to investigate an association between subjective and objective halitosis and GERD.

Methods

The subjects were enrolled from participants who visited a health promotion center at Seoul National University Bundang Hospital. For diagnosis of halitosis, a questionnaire was requested, and volatile sulfur compounds (VSCs) were measured by Halimeter. Self-conscious halitosis was defined as halitosis perceived by himself or herself. Informed halitosis was defined as halitosis perceived by others. Objective halitosis was defined when mean VSCs values were > 100 parts per billion. GERD was defined based on a questionnaire and endoscopy, including erosive esophagitis and non-erosive reflux disease (NERD).

Results

A total of 54 subjects (male:female = 33:21) with mean age of 46.0 ± 11.4 years were analyzed. The mean VSCs values were not significantly different between presence and absence of self-conscious halitosis (P = 0.322), but significantly different between presence and absence of informed halitosis (P = 0.021). Informed halitosis was associated with objective halitosis (P = 0.039). GERD, erosive esophagitis and NERD did not correlate with objective halitosis (P = 0.556, 0.206 and 0.902, respectively). In multivariable analysis, the relationship between objective halitosis and GERD symptoms including chest pain, heart burn, acid regurgitation, epigastric pain, hoarseness, globus sensation and coughing was not significant. Besides, GERD was not associated with self-conscious halitosis, informed halitosis and objective halitosis, respectively.

Conclusions

GERD might not be associated with self-conscious, informed halitosis and objective halitosis indicated by Halimeter results. Informed halitosis could be correlated with objective halitosis determined by the Halimeter.

Effects of high thoracic epidural anesthesia on ischemic cardiomyopathy cardiac function and autonomic neural function

We aimed at observing the effects of high thoracic epidural anesthesia (HTEA) on cardiac structure and function, heart rate variability (HRV), and QT interval variation (QTV) in ischemic cardiomyopathy (ICM) patients with chronic heart failure. We divided 30 ICM patients into HTEA (N = 16) and control (N = 14) groups.The control group was treated with medication, and the HTEA group was treated with HTEA and medication for 4 weeks. We measured the changes in the left-ventricular end-diastolic diameter (LVEDd) and left-ventricular ejection fraction (LVEF) before and after treatment by using echocardiography and examined changes in HRV and QTV using ambulatory electrocardiogram. HTEA significantly narrowed the LVEDd, improved LVEF, significantly increased the HRV, and significantly reduced the QTV in the ICM group compared to the control group. HTEA significantly narrowed the ventricular chamber diameter size of ICM patients, enhanced myocardial contractility, increased myocardial electrical stability, and improved the cardiac structure and function.

Association of gingival biotype with the results of scaling and root planing

PURPOSE

The concept of gingival biotype has been used as a predictor of periodontal therapy outcomes since the 1980s. In the present study, prospective and controlled experiments were performed to compare periodontal pocket depth (PPD) reduction and gingival shrinkage (GSH) after scaling and root planing (SRP) according to gingival biotype.

METHODS

Twenty-five patients diagnosed with chronic periodontitis participated in the present study. The PPD and GSH of the labial side of the maxillary anterior teeth (from the right canine to the left canine) were evaluated at baseline and 3 months after SRP. Changes in the PPD following SRP were classified into 4 groups according to the gingival thickness and initial PPD. Two more groups representing normal gingival crevices were added in evaluation of the GSH. The results were statistically analyzed using the independent t-test.

RESULTS

In the end, 16 patients participated in the present study. With regard to PPD reduction, there were no significant differences according to gingival biotype (P>0.05). Likewise, sites with a PPD of over 3 mm failed to show any significant differences in the GSH (P>0.05). However, among the sites with a PPD of under 3 mm, those with the thin gingival biotype showed more GSH (P<0.05).

CONCLUSIONS

PPD changes after SRP were not affected by gingival biotype with either shallow or deep periodontal pockets. GSH also showed equal outcomes in all the groups without normal gingival crevices. The results of SRP seem not to differ according to gingival biotype.

Association between serum ferritin and microalbuminuria in Type 2 diabetes in Taiwan

AIMS

Serum ferritin has been found closely related with diabetes and glucose metabolism, but its impact on diabetic nephropathy remains unknown. This study aimed to explore the association between serum ferritin and microalbuminuria in Type 2 diabetes.

METHODS

Eight hundred and fifty-one subjects with Type 2 diabetes were selected from a cohort participating in a glycaemic control study in Taiwan in 2008. We used urine albumin:creatinine ratio to define microalbuminuria; serum ferritin was divided into quartiles for analysis. Logistic regression and trend tests were used to delineate the association between serum ferritin and microalbuminuria.

RESULTS

Subjects with diabetes with higher ferritin tended to have more metabolic disorders, higher high-sensitivity C-reactive protein and higher prevalence of microalbuminuria. Compared with those in the lowest quartile, subjects with diabetes in the highest ferritin quartile were 55% (P = 0.029) more likely to have microalbuminuria. After controlling for demographics, metabolic profiles and other inflammatory markers, the association between serum ferritin levels and microalbuminuria remained significant (P for trend < 0.001). This independent relationship was not changed either for those who had better glycaemic control or those who had not used an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker.

CONCLUSIONS

The current study shows hyperferritinemia may be an independent risk factor of nephropathy in patients with Type 2 diabetes.

Reproductive biology of female bigeye tuna Thunnus obesus in the western Pacific Ocean

The reproductive biology of female bigeye tuna Thunnus obesus was assessed by examining 888 fish (ranging from 84·9 to 174·4 cm fork length, LF ) caught by Taiwanese offshore longliners in the western Pacific Ocean from November 1997 to November 1998 and November to December 1999 and 258 gonad samples from these fish. The overall sex ratio of the catch during the sampling differed significantly from 0·5, but males were predominant in sizes >140 cm LF . Reproductive activity (assessed by histology), a gonado-somatic index, and the size-frequency distributions of whole oocytes indicated that spawning occurred throughout the year and the major spawning season appeared to be from February to September. The estimated sizes at 50% maturity (LF50 ) of females was 102·85 cm (95% c.i.: 90·79-110·21 cm) and the smallest mature female was 99·7 cm LF . They are multiple spawners and oocytes develop asynchronously. The proportion of mature (0·63) and reproductively active (0·70) females with ovaries containing postovulatory follicles indicated that they spawn almost daily. Batch fecundity for 15 females with the most advanced oocytes (>730 µm) ranged from 0·84 to 8·56 million eggs (mean ± s.d. = 3·06 ± 2·09). The relationships between batch fecundity (FB , in millions of eggs) and LF (cm) and round mass (MR , kg) were FB=9·91×10-14LF6·38 (r(2)  = 0·84) and FB=8·89×10-4MR2·05 (r(2)  = 0·80), respectively. The parameters estimated in this study are key information for stock assessments of T. obesus in the western Pacific Ocean and will contribute to the conservation and sustainable yield of this species.

Nucleotide mismatches of foot-and-mouth disease virus during replication

As there is a lack of error correction mechanisms during RNA replication, foot-and-mouth disease virus (FMDV) has a very high mismatch rate, which leads to a high mutation rate, in the range of 10(-3) to 10(-5) per nucleotide site per genome replication. We examined the nucleotide mismatch of FMDV during replication, based on the whole genomes of the 7 serotypes retrieved from NCBI. With the Mega bio-software, SPSS, and Microsoft Excel, we studied the nucleotide differences compared to the sequence in the RefSeq database, and developed two probable mutation models, i.e., once mutation model and complication mutation model. Further analysis on the nucleotide mismatch during replication was made. We found that FMDV share similar difference rates between nucleotide and reverse differences, for example the mutation U→C and C→U. We also found that each nucleotide has its domain mismatch, and the virus kept a constant nucleotide composition during mutations.

HbA1c variability is associated with microalbuminuria development in type 2 diabetes: a 7-year prospective cohort study

AIMS/HYPOTHESIS

HbA(1c) variability has been shown to be an independent risk factor for nephropathy in patients with type 1 diabetes. In this study, we aimed to explore the association between HbA(1c) variability and microalbuminuria development in patients with type 2 diabetes. We also intended to test the applicability of serially measured HbA(1c) over 2 years for this risk assessment.

METHODS

Between 2003 and 2005, we recruited 821 middle-aged normoalbuminuric individuals with type 2 diabetes and followed them through to the end of 2010. The average follow-up time was 6.2 years. We defined microalbuminuria as a urine albumin to creatinine ratio of 30 mg/g (3.4 mg/mmol) or higher. HbA(1c) variability was calculated by the SD of serially measured HbA(1c). The Cox proportional hazards model was used to evaluate the association between HbA(1c) SD quartile and development of microalbuminuria.

RESULTS

The incidence of microalbuminuria for the overall population was 58.4, 58.6, 60.8 and 91.9 per 1,000 person-years for Q1- to Q4-adjusted HbA(1c) SD, respectively (p for trend = 0.042). Compared with patients in Q1, those in Q4 were about 37% more likely to develop microalbuminuria. The HR derived from a series of 2 year HbA(1c) measurements was similar to that from data collection for longer than 4 years.

CONCLUSIONS/INTERPRETATION

In addition to mean HbA(1c) values, HbA(1c) variability, even measured as early as 2 years, is independently associated with the development of microalbuminuria in patients with type 2 diabetes.

Ipr1 gene mediates RAW 264.7 macrophage cell line resistance to Mycobacterium bovis

Tuberculosis caused by Mycobacterium bovis (M. bovis) seriously affects efficiency of animal production with impacts on public health as well. Effective programmes of prevention and eradication of M. bovis infection therefore are urgently needed. Intracellular pathogen resistance gene 1 (Ipr1) is well known to mediate innate immunity to Mycobacterium tuberculosis (MTB), but there are no reports as to whether Ipr1 can enhance the phagocytic ability of macrophage against M. bovis. In this investigation, RAW 264.7 macrophage was transduced with lentiviral vector carrying Ipr1 (named Lenti-Ipr1); transgenic cells were identified by RT-PCR and western blotting. Transgenic positive cells (R-Ipr1) were then infected with an M. bovis virulent strain, with non-transduced cells used as control. When cell proliferation, viability and apoptosis of the two groups were investigated, it was found that infected RAW 264.7 died by necrosis whereas R-Ipr1 underwent apoptosis. Furthermore, the numbers of intracellular bacteria in R-Ipr1 were lower than those in control cells (P < 0.05). To identify the role of Ipr1, we measured the genes of Casp3, Mcl-1 and NOS2A which associated with macrophage activation and apoptosis by real-time quantitative PCR. The results demonstrated that Ipr1 gene expression can enhance anti-M. bovis infection of macrophage. This establishes a basis for the future production of Ipr1-transgenic cattle to strengthen the tuberculosis resistance.

A retrospective study of pulmonary infarction in patients with systemic lupus erythematosus from southern Taiwan

Since large-scale reports of pulmonary infarction in systemic lupus erythematosus (SLE) are limited, a retrospective study was performed for this manifestation in 773 hospitalized patients in southern Taiwan from 1999 to 2009. Pulmonary infarction was defined as the presence of pulmonary embolism, persistent pulmonary infiltrates, and characteristic clinical symptoms. Demographic, clinical, laboratory, and radiological images data were analyzed. There were 12 patients with pulmonary embolism and 9 of them had antiphospholipid syndrome (APS). Six patients (19 to 53 years, average 38.2 ± 12.6) with 9 episodes of lung infarction were identified. All cases were APS and four episodes had coincidental venous thromboembolism. There were four episodes of bilateral infarction and seven episodes of larger central pulmonary artery embolism. Heparin therapy was routinely prescribed and thrombolytic agents were added in two episodes. Successful recovery was noted in all patients. In conclusion, there was a 0.8% incidence of pulmonary infarction in patients with SLE, all with the risk factor of APS. Differentiation between pulmonary infarction and pneumonia in lupus patients should be made; they have similar chest radiography with lung consolidation but require a different clinical approach in management. Although this report is a retrospective study with relatively small numbers of lupus patients with lung infarcts, our observation might provide beneficial information on the clinical features and radiological presentations during the disease evolution of pulmonary infarction in SLE with APS.

Abstract P4-01-03: The Homeobox Protein H0XC10 Is Overexpressed in Breast Cancer and Confers Resistance to Chemotherapy

Background: Breast cancer is the second leading cause of cancer deaths in women worldwide. Although chemotherapy is effective, resistance to drugs develops over time and can account for treatment failure in over 90% of metastatic breast cancer patients. HOX genes are homeobox-containing transcription factors well-known for their role in morphogenesis. However, accumulating evidence has emphasized their importance during carcinogenesis and metastasis. The goal of this study is to understand the role of HOXC10 in breast cancer and the consequence of its overexpression in conferring chemotherapy resistance.

Methods: We conducted a tiling array of all four HOX clusters to identify dysregulated HOX genes in a panel of primary and metastatic breast cancer tissues, and validated the overexpression of HOXC10 in metastatic breast cancer. Next we established cell lines that stably overexpress HOXC10 and others where endogenously overexpressed HOXC10 was silenced by shRNAs, and determined phenotypic and biochemical changes resulting from these manipulations.

Results: HOXC10 is overexpressed in 67% of primary breast tumors (n=31), in 82% of the metastatic tissues (n=49) and in most breast cancer cell lines. When compared to cancers at other sites, overexpression tends to be significantly higher in breast cancer, and correlates with increasing grade and tumor size. Cell survival assays (MTT and colony formation) after drug treatment show that overexpression of exogenous HOXC10 in MCF10A conferred drug resistance. Further molecular examination revealed that overexpression of HOXC10 led to a dysregulation in the Rb-E2F pathway, and therefore the G1/S checkpoint was affected. In addition, the tendency for the formation of 8N cells and the concomitant protection from apoptosis suggested that HOXC10 overexpression might lead to genomic endoreduplication and instability. This fact along with the strikingenhanced recovery of the cells from pactitaxel treatment (as compared to the recovery from any other chemotherapeutic drug) and the protection from mitotic catastrophe implied a role of HOXC10 in the mitotic checkpoint. This was confirmed by a dysregulation of the expression of the genes involved in this checkpoint. All these experiments were further validated by stably expressing a shRNA to HOXC10 in SUM159 breast cancer cells with high endogenous HOXC10 levels. Conclusion: Our studies show for the first time that HOXC10, a homeobox protein previously shown to be regulated during the cell cycle and to have a positive effect on proliferation, is overexpressed in the majority of breast cancers. This upregulation may have some clinical implications since cells with higher expression of HOXC10 tend to have more invasive properties, more genomic instability, and are more resistant to some chemotherapy drugs.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P4-01-03.

Fatal crash trends for Australian young drivers 1997-2007: geographic and socioeconomic differentials

BACKGROUND

Little has been published on changes in young driver fatality rates over time. This paper examines differences in Australian young driver fatality rates over the last decade, examining important risk factors including place of residence and socioeconomic status (SES).

METHODS

Young driver (17-25years) police-recorded passenger vehicle crashes were extracted from New South Wales State records from 1997-2007. Rurality of residence and SES were classified into three levels based on drivers' residential postcode: urban, regional, or rural; and high, moderate, or low SES areas. Geographic and SES disparities in trends of fatality rates were examined by the generalized linear model. Chi-square trend test was used to examine the distributions of posted speed limits, drinking driving, fatigue, seatbelt use, vehicle age, night-time driving, and the time from crash to death across rurality and socioeconomic status.

RESULTS

Young driver fatality rate significantly decreased 5% per year (p<0.05); however, stratified analyses (by rurality and by SES) showed that only the reduction among urban drivers was significant (average 5% decrease per year, p<0.01). The higher relative risk of fatality for rural versus urban drivers, and for drivers of low versus high SES remained unchanged over the last decade. High posted speed limits, fatigue, drink driving and seatbelt non-use were significantly associated with rural fatalities, whereas high posted speed limit, fatigue, and driving an older vehicle were significantly related to low SES fatality.

CONCLUSION

The constant geographic and SES disparities in young driver fatality rates highlight safety inequities for those living in rural areas and those of low SES. Better targeted interventions are needed, including attention to behavioral risk factors and vehicle age.

Road crash trends for young drivers in New South Wales, Australia, from 1997 to 2007

OBJECTIVES

The objective of this article was to explore overall crash and injury trends over the past decade for young drivers residing in New South Wales (NSW), Australia, including gender and age disparities.

METHODS

Passenger vehicle crashes for drivers aged 17-25 occurring during 1997-2007 were extracted from the state crash database to calculate crash rates (per licensed driver). Generalized linear models were used to examine crash trends over time by severity of driver injury, adjusting for age, gender, rurality of residence, and socioeconomic status. Yearly adjusted relative risks of crash by gender and by age group were also examined over the study period.

RESULTS

Young driver noninjury and fatality rates significantly decreased by an average of 4 percent (95% CI: 4-5) and 5 percent (95% CI: 0-9) respectively each year from 1997 to 2007. Young driver injury rates significantly increased by about 12 percent (95% CI: 9-14) to the year 2001 and then significantly decreased. The relative risk of crash (regardless of driver injury) for males compared to females significantly decreased over time. Compared to drivers aged 21-25, drivers aged 17 and particularly 18- to 20-year-olds had significantly and consistently higher crash risks across the study period.

CONCLUSIONS

Overall, there has been a significant decline in young driver crashes in NSW over the last decade. Regardless of injury severity, males' risk of crash has reduced more than female young drivers, but drivers aged 17 continue to be at higher risk. These findings provide feedback on potential road safety successes and areas needing specific interventions for future improvements.

Health-related quality of life predicts hospital admission within 1 year in people with diabetes: a nationwide study from Taiwan

AIMS

To investigate whether health-related quality of life (HRQOL) predicts hospital admission in a nationally representative sample of adults with diabetes.

METHODS

We conducted a prospective study on persons aged > or = 18 years with self-reported physician-diagnosed diabetes (n = 797) who participated in the National Health Interview Survey in Taiwan, 2001. Of these potential participants, 674 provided consent for data linkage and were successfully linked to the National Health Insurance claims data. We analysed the associations between the Short Form 36 (SF-36) subscales and summaries and the occurrence of hospital admission for any cause during 2002.

RESULTS

Approximately 23% of participants with diabetes had at least one hospital admission during 2002. After adjusting for demographic characteristics, co-morbidities and diabetics-related attributes, those who had been admitted to hospital had significantly poorer mean scores on each of the physical dimensions, physical components summary (PCS) and social functioning domain of the SF-36 at baseline. In logistic regression models, poorer scores on the PCS [odds ratio (OR) = 1.80; 95% confidence interval (CI) = (1.14-2.86)], duration of diabetes > or = 10 years [OR = 2.10; 95% CI = (1.14-3.89)] and the presence of heart disease [OR = 1.63; 95% CI = (1.01-2.63)] were significantly associated with an increased risk of hospital admission.

CONCLUSION

In people with diabetes, poorer scores on the PCS of the SF-36 at baseline may provide additional information for assessment of hospital admission risk, independent of other measures of health outcomes.

A simplified tumour model established via Epstein-Barr virus-encoded, nasopharyngeal carcinoma-derived oncogene latent membrane protein 1 in immunocompetent mice

The expression and immune modulation of Epstein-Barr virus-encoded oncogene latent membrane protein 1 (N-LMP1) is essential in the pathogenesis of nasopharyngeal carcinoma. In previous studies, cell transformation has been induced by the expression of EBV-encoded N-LMP1 in non-tumour BALB/c-3T3 cells and these cells have then been used to form tumours in T-cell-deficient nude mice. However, studies using this model have been limited by the lack of a competent immune system. To facilitate the study of immune components in N-LMP1-driven oncogenesis, we herein developed a simplified N-LMP1-derived tumour model in immunocompetent mice. Cell transformation was induced by the expression of N-LMP1 in BALB/c-3T3 cells, and these transformants were used to induce oncogenesis in BALB/c mice. In contrast to the 100% successful tumour-induction rate in nude mice treated with monodispersed transformed cells, the tumour incidence in BALB/c mice was only 5-36%. However, the transplantation of tumour fragments into BALB/c mice yielded a reproducible tumour-induction rate of >85%, which is acceptable for most of the research needs. This novel model of N-LMP1-directed oncogenesis in an immunocompetent environment may serve as an important platform for the future assessment of N-LMP1-targeted tumour therapies.

User adaptive handwriting recognition by self-growing probabilistic decision-based neural networks

It is generally agreed that, for a given handwriting recognition task, a user dependent system usually outperforms a user independent system, as long as a sufficient amount of training data is available. When the amount of user training data is limited, however, such a performance gain is not guaranteed. One way to improve the performance is to make use of existing knowledge, contained in a rich multiuser data base, so that a minimum amount of training data is sufficient to initialize a model for the new user.We mainly address the user adaption issues for a handwriting recognition system. Based on self-growing probabilistic decision-based neural networks (SPDNNs), user adaptation of the parameters of SPDNN is formulated as incremental reinforced and antireinforced learning procedures, which are easily integrated into the batched training procedures of the SPDNN. In this study, we developed 1) an SPDNN based handwriting recognition system; 2) a two-stage recognition structure; and 3) a three-phase training methodology for a) a global coarse classifier (stage 1); b) a user independent hand written character recognizer (stage 2); and c) a user adaptation module on a personal computer. With training and testing on a 600-word commonly used Chinese character set, the recognition results indicate that the user adaptation module significantly improved the recognition accuracy. The average recognition rate increased from 44.2% to 82.4% in five adapting cycles, and the performance could finally increase up to 90.2% in ten adapting cycles.

Protection abilities of influenza B virus DNA vaccines expressing hemagglutinin, neuraminidase, or both in mice

Every year, a vaccination against Influenza B virus (IBV) is essential due to an antigenic variation. Development of an efficient and convenient vaccine is important for the prevention of viral infection. This study reports examination of the protective immunity in mice evoked by a single inoculation of plasmid DNA expressing hemagglutinin (HA DNA) or neuraminidase (NA DNA) of IBV. The HA DNA or NA DNA was injected intramuscularly into BALB/c mice separately or as a mixture. The injection of plasmid was followed by an electroporation close to the site of puncture. Four weeks later, the immunized mice were challenged with a lethal dose of IBV. The protective abilities of DNA vaccines were evaluated by the detection of specific antibodies in serum, survival rate, virus titer in lungs, and change of body weight. We found that a single dose of HA DNA or NA DNA induced the formation of specific antibodies and conferred effective protection against the lethal challenge of IBV. However, the combined vaccine HA DNA and NA DNA enhanced the protective ability of immunized mice. The obtained results suggested that immunization with single dose of HA DNA, NA DNA or with combination of both could be an efficient method for preventing IBV infection.

Effect of microwave annealing temperatures on lead zirconate titanate thin films

Lead zirconate titanate (Pb(1.1)(Zr(0.52)Ti(0.48))O(3)) thin films of thickness 260 nm on Pt/Ti/SiO(2)/Si substrates were densified by 2.45 GHz microwave annealing. The PZT thin films were annealed at various annealing temperatures from 400 to 700 °C for 30 min. X-ray diffraction showed that the pyrochlore phase was transformed to the perovskite phase at 450 °C and the film was fully crystallized. The secondary (again pyrochlore) phase was observed in the PZT thin films, which were annealed above 550 °C. The surface morphologies were changed above 550 °C of the PZT thin films due to the secondary phase. Higher dielectric constant (ε(r)) and lower dielectric loss coercive field (E(c)) were achieved for the 450 °C film than for the other annealed films.

GSK3 beta mediates suppression of cyclin D2 expression by tumor suppressor PTEN

PTEN, encoding a lipid phosphatase, is a tumor suppressor gene and is mutated in various types of cancers. It is reported to regulate G1 to S phase transition of the cell cycle by influencing the expression, protein stability and subcellular location of cyclin D1. Here, we provide evidence that PTEN modulates the transcription and protein stability of cyclin D2. Targeted deletion of Pten in mouse embryonic fibroblasts (MEFs) endowed cells with greater potential to overcome G1 arrest than wild-type MEFs and led to the elevated expression of cyclin D2, which was suppressed by the introduction of PTEN. We further defined a pathway involving GSK3beta and beta-catenin/TCF in PTEN-mediated suppression of cyclin D2 transcription. LiCl, an inhibitor of GSK3beta, abolished inhibitory effect of PTEN on cyclin D2 expression, and TCF members could directly bind to the promoter of cyclin D2 and regulate its transcription in a CREB-dependent manner. Our results indicate that the downregulation of cyclin D2 expression by PTEN is mediated by the GSK3beta/beta-catenin/TCF pathway in cooperation with CREB, and suggest a convergence from the PI-3 kinase/PTEN pathway and the Wnt pathway in modulation of cyclin D2 expression.

Cell-type-specific limitation on in vivo serotonin storage following ectopic expression of the Drosophila serotonin transporter, dSERT

The synaptic machinery for neurotransmitter storage is cell-type specific. Although most elements of biosynthesis and transport have been identified, it remains unclear whether additional factors may be required to maintain this specificity. The Drosophila serotonin transporter (dSERT) is normally expressed exclusively in serotonin (5-HT) neurons in the CNS. Here we examine the effects of ectopic transcriptional expression of dSERT in the Drosophila larval CNS. We find a surprising limitation on 5-HT storage following ectopic expression of dSERT and green fluorescence protein-tagged dSERT (GFP-dSERT). When dSERT transcription is driven ectopically in the CNS, 5-HT is detectable only in 5-HT, dopamine (DA), and a very limited number of additional neurons. Addition of exogenous 5-HT does not dramatically broaden neuronal storage sites, so this limitation is only partly due to restricted intercellular diffusion of 5-HT. Furthermore, this limitation is not due to gross mislocalization of dSERT, because cells lacking or containing 5-HT show similar levels and subcellular distribution of GFP-dSERT protein, nor is it due to lack of the vesicular transporter, dVMAT. These data suggest that a small number of neurons selectively express factor(s) required for 5-HT storage, and potentially for function of dSERT.

Tuberculous peritonitis in a haemodialysis patient with elevated serum CA 125 and hypercalcaemia

CA 125, a glycoprotein derived from coelomic epithelium, is used primarily as a marker of epithelial ovarian cancer. However, elevated levels of serum CA 125 have also been detected in other benign and malignant disorders. This study describes a haemodialysis patient who contracted tuberculous peritonitis associated with hypercalcaemia, erythropoietin-resistant anaemia and elevated CA 125, which normalised gradually following antituberculosis treatment. Tuberculous peritonitis should be considered in the differential diagnosis of ascites with elevated serum CA 125. Additionally, CA 125 is a useful marker for monitoring response to tuberculous peritonitis treatment.

Low-molecular-weight heparin successfully treating a nephrotic patient complicated by renal and ovarian vein thrombosis and pulmonary embolism

Thromboembolic complications, frequently associated with idiopathic membranous glomerulonephritis, are frequent and serious problems associated with nephrotic syndrome. However, ovarian vein thrombosis associated with nephrotic syndrome has never been reported. This study describes the case of a 35-year-old woman with idiopathic membranous glomerulonephritis who developed left renal vein thrombosis with ovarian vein thrombosis and pulmonary embolism. The thromboembolic complications were successfully treated with low-molecular-weight heparin. Low-molecular-weight heparin thus appears safe and effective for treating thromboembolism in nephrotic patients.

Microbial kinetic analysis of three different types of EBNR process

The disadvantages of developed biological nutrient removal (BNR) processes (additional energy for liquid circulation and addition of external carbon substrate for denitrification in anoxic zones) were improved by reconfiguring the process into (1) an anaerobic zone followed by multiple stages of aerobic-anoxic zones (TNCU3 process) or (2) anaerobic, oxic, anoxic, oxic zones in sequence (TNCU2 process). These two pilot plants were operated at a recycling sludge ratio of 0.5 without internal recycle of nitrified supernatant. The sludge retention time was maintained at 10 d. The main objective of this study is to analyze the kinetics of different microorganisms in these two processes and A2O process by using the Activated Sludge Model No. 2d. The effective removal efficiency of carbon, total phosphorus and total nitrogen at 87-98%, 92-100% and 63-80%, respectively, were achieved in the testing runs. According to model simulations, the microbial kinetics in the TNCU3 and TNCU2 processes would be affected by different operations. When the step feeding strategy was adopted, the HRT was longer due to the less influent flowrate in the front stages and the microbes would grow in quantities by about 6% in the aerobic reactors. In the followed anoxic reactors, the microbes would decrease in quantities by about 12% due to the dilution effect. The dilution effects in TNCU3 and TNCU2 processes did not take place in A2O process because the recycling mixed liquid from the aerobic reactor to the anoxic reactor still contained particulate components. The XH, XPAO, and XAUT concentrations in the effluent of the last tank were lower when the step-feeding mode was adopted. The TNCU3 and TNCU2 processes could be operated efficiently without nitrified liquid circulation and addition of external carbon substrate for denitrification.

Experimental measurement of the electron energy distribution function in the radio frequency electron cyclotron resonance inductive discharge

Recently, the existence of electron cyclotron resonance (ECR) in a weakly magnetized inductively coupled plasma (MICP) has been evidenced [ChinWook Chung et al., Phys. Rev. Lett. 80, 095002 (2002)]. The distinctive feature of the ECR effect in the MICP is efficacious heating of low-energy electrons. In the present paper, electron heating characteristics in the MICP have been investigated by observing electron energy distribution function dependencies on various external parameters such as gas pressure, driving frequency, and rf power (electron density). It is found that the ECR effect on electron heating becomes enhanced with decreasing pressure or increasing driving frequency. The ECR heating becomes weak at high rf power due to the electron-electron collisions.

Prediction of disease persistence after conization for microinvasive cervical carcinoma and cervical intraepithelial neoplasia grade 3

We attempted to determine the significant variables and to predict the probability of disease persistence after conization for microinvasive cervical carcinoma and cervical intraepithelial neoplasia grade 3 (CIN3). We analyzed 133 patients from 2001 to 2002 who had a subsequent hysterectomy after conization. The histological findings of the cone specimens, together with the clinical parameters, were correlated with the presence of residual dysplasia in the hysterectomy specimen. The probability of having residual dysplasia was calculated based on the function of the significant variables obtained by logistic regression analysis. Of the 133 patients, 42 (31.6%) had residual disease in their hysterectomy specimens. Using multivariate analysis only for the postmenopausal state, positive endocervical curettage, positive margin, and microinvasive carcinoma were predictive of residual dysplasia. The probabilities of having residual dysplasia were about 0.99, 0.84, 0.4, 0.07, and 0.01 in patients with a presence of all four, any three, any two, any one, and no risk factors, respectively. The best cutoff probability determined by the receiver operating characteristic curve was 0.32, yielding a sensitivity of 81% and a specificity of 88%. Based on these results, patients with the presence of any two or more of the risk factors mentioned above should be considered as a high-risk group for having disease persistence after conization for the treatment of CIN3 and microinvasive carcinoma.

The effect of glucagon-induced gastric relaxation on TLOSR frequency

This study aimed to determine the effect of glucagon-induced gastric relaxation on the frequency of transient lower oesophageal sphincter relaxations (TLOSRs). Eight normal subjects (four male, age 18-52 y) were studied after a 6-h fast using a combined manometric barostat assembly. The recording was divided into two 1-h sessions: (1) a baseline period with the barostat set at minimal distending pressure (MDP) + 2 mmHg and (2) a period with continuous glucagon or placebo infusion with barostat set at MDP + 2 mmHg. Patients were studied on two different days and randomly received glucagon (4.8 microg kg(-1) bolus followed by 9.6 microg kg(-1) h(-1) infusion) on 1 day and placebo (saline) on another. Lower oesophageal sphincter (LOS) pressure, frequency of TLOSRs, and barostat bag volumes were determined for both placebo and glucagon infusion. Glucagon induced significant fundal relaxation compared with placebo (P < 0.05) and significantly decreased baseline LEOS pressure (P < 0.05). The frequency of TLOSRs was not altered by glucagon infusion compared with placebo. Despite causing substantial proximal stomach relaxation, glucagon did not increase TLOSR frequency. This suggests that the relevant gastric mechanoreceptors responsible for triggering TLOSRs do not respond to passive elongation.

Method for the determination of dialkyl phosphates in urine by strong anion exchange disk extraction and in-vial derivatization

A method for the determination of four dialkylphosphate metabolites in urine by strong anion exchange disk (SAX) was investigated. Calcium hydroxide was added to a 1-mL urine sample to reduce interference. The aliquot was passed through the SAX disk to accumulate dialkylphosphate metabolites on the disk. The retained dialkylphosphate metabolites were derivatized with methyl iodide in acetonitrile online, and the resulting methyl esters of dialkylphosphate metabolites were directly analyzed by capillary column gas chromatography with flame photometric detection. The recoveries of these dialkylphosphate metabolites were found to be stable. When the intact sample was diluted with deionized water at a 1:1 ratio, the recoveries were both increased and stabilized. The urine samples collected from eight fruit farmers showed that levels of dialkylphosphate metabolites in urine were significantly different before and after pesticide application, indicating the method established in this study is applicable for real sample analysis. Compared with previous studies, this method not only can greatly simplify sample preparation, but it can also significantly reduce the consumption of toxic solvents in sample preparation.

Electron cyclotron resonance in a weakly magnetized radio-frequency inductive discharge

The evolution of the electron energy distribution function (EEDF) over a weak magnetic field range is investigated in magnetized radio-frequency (rf) inductive discharges under a collisionless regime where an anomalous skin effect and electron cyclotron resonance (ECR) can occur. A significant change in the low-energy range of the EEDF is found in the ECR condition during the evolution. The observed result reveals the low-energy electrons are efficiently heated by the rf ECR in the presence of the anomalous skin effect. The calculated result of the electron distribution based on kinetic theory is in good agreement with the experiment.

Prevalence, awareness, treatment and control of hypertension in Taiwan: results of Nutrition and Health Survey in Taiwan (NAHSIT) 1993-1996

The objective of this paper is to describe hypertension status in Taiwan using data from the Nutrition and Health Survey in Taiwan (NAHSIT) 1993-1996, which adopted a clustered stratified multistage sampling scheme. A total of 4838 males and 4876 females aged 4 years and above were interviewed and examined corresponding to a response rate of 74%. Almost all of them (97.5%) had blood pressures measured. The results show that the mean blood pressure of adult males was higher than that of adult females below 45 years of age. After that, the pattern was reversed. When defined by JNC IV criteria (SBP/DBP > or = 160/95 mm Hg or taking antihypertensive drugs), the prevalence was 13% in adult males (> or = 19 years) and 12% in adult females. When defined by JNC VI criteria (SBP/DBP > or = 140/90 mm Hg or taking antihypertensive drugs), the prevalence was 26% in adult males and 19% in adult females. The prevalence in the mountainous area, was the highest among the seven survey strata. Under the JNC IV definition, 43% males and 53% females with hypertension knew their disease status, 31% of males and 45% of females took medicine for it, and 15% of males and 22% of females had their blood pressure under control. Percentages of awareness, treatment, and control were much lower with the JNC V definition, which was introduced toward the end of survey period. People in metropolitan areas had the highest rates of awareness, treatment, control, and compliance to medication.

Identification of genes induced in vivo during Klebsiella pneumoniae CG43 infection

A novel in vivo expression technology (IVET) was performed to identify Klebsiella pneumoniae CG43 genes that are specifically expressed during infection of BALB/c mice. The IVET employed a UDP glucose pyrophosphorylase (galU)-deficient mutant of K. pneumoniae which is incapable of utilizing galactose and synthesizing capsular polysaccharide, as demonstrated by its low virulence to BALB/c mice and a white nonmucoid colony morphology on MacConkey-galactose agar. By using a functional galU gene as the reporter, an IVE promoter could render the galU mutant virulent while maintaining the white nonmucoid colony phenotype. A total of 20 distinct sequences were obtained through the in vivo selection. Five of them have been identified previously as virulence-associated genes in other pathogens, while another five with characterized functions are involved in regulation and transportation of nutrient uptake, biosynthesis of isoprenoids, and protein folding. No known functions have been attributed to the other 10 sequences. We have also demonstrated that 2 of the 20 IVE genes turn on under iron deprivation, whereas the expression of another five genes was found to be activated in the presence of paraquat, a superoxide generator.

Expression of the Klebsiella pneumoniae CG21 acetoin reductase gene in Clostridium acetobutylicum ATCC 824

Acetoin reductase catalyzes the production of 2,3-butanediol from acetoin. The gene encoding the acetoin reductase of Klebsiella pneumoniae CG21 was cloned and expressed in Escherichia coli and Clostridium acetobutylicum ATCC 824. The nucleotide sequence of the gene encoding the enzyme was determined to be 768 bp long. Expression of the K. pneumoniae acetoin reductase gene in E. coli revealed that the enzyme has a molecular mass of about 31,000 Da based on sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis. The K. pneumoniae acetoin reductase gene was cloned into a clostridial/E. coli shuttle vector, and expression of the gene resulted in detectable levels of acetoin reductase activity in both E. coli and C. acetobutylicum. While acetoin, the natural substrate of acetoin reductase, is a typical product of fermentation by C. acetobutylicum, 2,3-butanediol is not. Analysis of culture supernatants by gas chromatography revealed that introduction of the K. pneumoniae acetoin reductase gene into C. acetobutylicum was not sufficient for 2,3-butanediol production even though the cultures were producing acetoin. 2,3-Butanediol was produced by cultures of C. acetobutylicum containing the gene only when commercial acetoin was added.

Using the overdispersed exponential family to estimate the distribution of usual daily intakes of people aged between 18 and 28 in Taiwan

Assessment of usual dietary intake of a population is essential to understand the nutrition status of the population. Methods like 24-hour dietary recall and food records are commonly used for this task. However, within-individual variation exists in the food record data. Methods considering measurement errors have been used to evaluate the association between nutrient intakes and diseases. Few have been devoted to estimating the distribution of usual daily intakes. This paper proposes applying the formulation of the overdispersed exponential family to estimate the distribution of usual nutrient intake and applies the adjustments developed by Liu to reduce the variance of the distribution. The proposed method has the advantages of working on the original scale of data and implementation convenience. The adjustment of the variance is carried out by dividing the variance into within-individual variance and among-individual variance. The adjusted variance, then, is used to estimate the distribution of the usual daily intake. Sampling weights are considered in all the steps, except the estimation of the ratio of within to among variance. The data for this study are from the Nutritional and Health Survey in Taiwan conducted between 1993 and 1996 (NAHSIT, 1993-1996). An independent external set of data for people aged between 18 and 28 years (49 males and 20 females) is used to estimate the ratio of within to among individual variance. Due to the availability of data in estimating the ratio of within to among individual variance, 430 males and 422 females in the NAHSIT sample are used to estimate the distribution of usual daily intakes for people aged between 18 and 28 in Taiwan. The distribution also allows us to estimate the proportion of people who do not meet the recommended daily nutrient allowance (RDNA). The results show that the intakes of calcium and vitamin E of this group of people fall far below RDNA.

Hyperuricemia and gout in Taiwan: results from the Nutritional and Health Survey in Taiwan (1993-96)

OBJECTIVE

To evaluate the prevalence of hyperuricemia in Taiwan.

METHODS

A multi-stage stratified sampling scheme was used in Nutrition and Health Survey, which was conducted in Taiwan between 1993 and 96. Complete biochemical and questionnaire data for 2754 males and 2953 females aged 4 years and older were included in the analysis. The colorimetric enzymatic method was used to measure plasma uric acid in fasting blood samples. Information on self-reported, physician-diagnosed gout was also obtained.

RESULTS

The uric acid values of males were found to reach a peak between the ages of 13 and 18 and decrease slightly after 18. The uric acid values of females were stable before the age of 18, decreasing slightly between 19 and 44 years, and increasing in the mid to older age groups (> or = 45 years). Twenty-six percent of adult males (> or = 19 years) and 22% of older males (> or = 45 years) either had hyperuricemia (serum uric acid > 458.0 microM or 7.7 mg/dl) or were taking medication for it. Seventeen percent of adult females and 23% of older females either had hyperuricemia (serum uric acid > 392.57 microM or 6.6 mg/dl) or were taking medication for it. Both adult males and females in mountainous areas, who were primarily aboriginal, had the highest prevalence of hyperuricemia (> 50%) among the 7 survey areas. Mean body mass index (BMI), alcohol consumption, and prevalence of gout were among the highest in mountainous people compared to all included in the study. Multivariate analysis showed that mountainous area, age and BMI are important factors associated with hyperuricemia in males, whereas mountainous area, Class II townships, and BMI are the factors associated with hyperuricemia in females.

CONCLUSIONS

We found a high prevalence of hyperuricemia in Han Chinese in Taiwan despite a lack both of obesity and high alcohol consumption. Mountainous people (mainly aborigines) in Taiwan have an even higher prevalence of hyperuricemia, which cannot be completely explained by obesity and alcohol consumption. Genetic components and other environmental factors may have contributed to this pattern of hyperuricemia.

Reduction of sperm motility in a male laboratory worker exposed to solvents: a case study

A 34-year-old male laboratory worker suffered from asthenospermia and fertility problems. He was suspected of having been exposed to solvents used at work due to a malfunction of the ventilation system in his laboratory from August 1996 to April 1997. A laboratory walk-through and air and bulk sample collection were performed to determine the possible exposure levels of chemical hazards in his job. The scenario was reconstructed to simulate the worker's previous exposure during the ventilation shutdown period. It was found that the worker was possibly exposed to chloroform at levels of 10 or 50 times higher than the permissible exposure limit or the threshold limit value of 2 hr/day, 5.5 days/week, and 4.25 weeks/month for 8 months. Because chloroform is known to be spermatotoxic, the possibility of chloroform causing the worker's asthenospermia cannot be ruled out. Further study on spermatotoxicity of chloroform is warranted.

Evaluation of bone mineral density by quantitative ultrasound of bone in 16,862 subjects during routine health examination

Caucasians and Asians are among those with the highest risk for involutional osteoporosis. To obtain accurate data about the prevalence of osteoporosis or osteopenia in different age groups, a large epidemiological study is necessary. Quantitative ultrasound (QUS) of bone is a promising technique in assessing bone microarchitecture in addition to bone mass. This study had two aims. The first was to establish bone mineral density (BMD) using QUS in subjects with no obvious disease undergoing routine health examination. The second was to determine risk factors for osteoporosis in Taiwan in order that better prevention and treatment measures may be provided for these patients. A prospective study of the risk factors for fracture was conducted in the health examination division of Chang Gung Medical Center in Linkou, Taiwan, from January 1996 to December 1997. Broadband ultrasound attenuation of the right heel was measured with an achilles bone densitometer (Lunar, Nauheim, Germany). A total of 16,862 subjects were examined, including 9,314 women (mean age 51.5+/-11.7 years) and 7,548 men (mean age 51.1+/-12.1 years). The incidence of osteoporosis in all subjects increased from 1.13% in the 21--30-year-old age group to 54.55% in those over 80 years of age. 12.02% of the subjects had osteoporosis and 34.45% had osteopenia. From multivariate analysis, bone density evaluated by QUS showed a relationship with age, gender, body mass index, waist/hip ratio, smoking and frequency of exercise. In conclusion, BMD evaluated by QUS is not found to be higher in Taiwan than elsewhere. The role of QUS in predicting fractures in Taiwan requires further investigation.

The influence of long-term different diabetic therapies on plasma leptin in type 2 diabetic subjects

The aim of this study was to assess the effect of the long-term different diabetic therapies on the plasma leptin level in type 2 diabetic subjects. We measured plasma leptin, body fat and fasting plasma insulin in 96 type 2 diabetic male subjects. They had received the same treatment regimen for more than one year (3.5 +/- 2.3 years, mean +/- SD) and were weight-stable over the previous three months. The distribution was as follows: diet control group: 32, oral hypoglycemic agent (OHA) group: 32, and insulin group: 32. The results showed that the plasma leptin level of the different therapy groups was all positively correlated with body fat. The fasting insulin levels were significantly higher (p < 0.0001) in the insulin group than those in the other two groups. The fasting insulin of the OHA group was also greater than that of the diet group but was not statistically significant. The leptin concentrations were significantly higher in the insulin group (p < 0.001) and OHA group (p = 0.0082) than that in the diet group. The leptin concentrations of insulin group were also significantly higher (p = 0.0021) than that of the OHA group. Stepwise multiple regression analysis revealed that the significant differences in the leptin level of whole group was mainly affected by fasting insulin (p < 0.0001), followed by fat percentage (p = 0.001), fat distribution (p = 0.009) and fasting sugar (p = 0.02), whereas there was no association of leptin with age, height, glycosylated hemoglobin A1c, lipid, or blood pressure. We concluded that long-term different diabetic therapies may affect the plasma leptin level, which is mediated mainly by insulin changes. This insulin effect is independent of body fat and may be superior to the fat effect on plasma leptin in the type 2 diabetic patients.

Comparison of official coders versus physician panel in assignment of underlying cause of death

BACKGROUND AND PURPOSE

In outcome analyses of clinical trials and mortality follow-up studies, the underlying cause of death (UCOD) is commonly assigned either by official coders or by a panel of physicians. We evaluated the validity of UCOD assigned by official coders by comparison with the assignments of a panel of physicians who reviewed the available medical records of the deceased.

METHODS

The comparisons focused on deaths occurring from October 1995 through June 1998 in a series of residents in a veterans home. Because of limited resources, only the first 104 deaths that occurred during the study period were included. Agreement rate, sensitivity, specificity, and kappa statistics were calculated to assess the consistency of coder versus physician panel assignment of UCOD by selected main causes of death. For 32 of the 104 deaths, the panel concluded that the information obtained from medical records was insufficient to determine the UCOD, and the following analyses were confined to the other 72 deaths.

RESULTS

For the 72 deaths considered by the panel to have sufficient information to determine UCOD, all four physicians agreed on a single UCOD in 50 (69%) cases, while three or four agreed in 66 (92%) cases. A consensus was reached in cases with disagreement. The two procedures completely agreed in 40 (56%) of the deaths. For general category UCOD, the kappa value was high for cancer (0.83) and cardiovascular disease (CVD, 0.73) but only moderate for pulmonary disease (PD, 0.60). When the UCOD assigned by the panel was used as the gold standard, official coders showed relatively low sensitivity for correct determination of UCOD in cases of CVD (0.76) compared with cancer (0.86) and PD (0.80).

CONCLUSIONS

Given the high inter-physician consistency and the relatively low sensitivity of official coders in assigning CVD as the UCOD, we conclude that the use of clinical review panels would provide more accurate UCOD assignments for use in outcome analyses in mortality follow-up studies and clinical trials in Taiwan.