Long-Term Exposure to AIR Pollution and COVID-19 Mortality and Morbidity in DENmark: Who Is Most Susceptible? (AIRCODEN).

INTRODUCTION: Early ecological studies have suggested a link between air pollution and Coronavirus Diseases 2019 (COVID-19); however, the evidence from individual-level prospective cohort studies is still sparse. Here, we have examined, in a general population, whether long-term exposure to air pollution is associated with the risk of contracting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and developing severe COVID-19, resulting in hospitalization or death and who is most susceptible. We also examined whether long-term exposure to air pollution is associated with hospitalization or death due to COVID-19 in those who have tested positive for SARS-CoV-2. METHODS: We included all Danish residents 30 years or older who resided in Denmark on March 1, 2020. and followed them in the National COVID-19 Surveillance System until first positive test (incidence), COVID-19 hospitalization, or death until April 26, 2021. We estimated mean levels of nitrogen dioxide (NO2), particulate matter with an aerodynamic diameter <2.5 µm (PM2.5), black carbon (BC), and ozone (O3) at cohort participants' residence in 2019 by the Danish Eulerian Hemispheric Model/Urban Background Model. We used Cox proportional hazard models to estimate the associations of air pollutants with COVID-19 incidence, hospitalization, and mortality adjusting for age, sex, and socioeconomic status (SES) at the individual and area levels. We examined effect modification by age, sex, SES (education, income, wealth, employment), and comorbidities with cardiovascular disease, respiratory disease, acute lower respiratory infections, diabetes, lung cancer, and dementia. We used logistic regression to examine association of air pollutants with COVID-19-related hospitalization or death among SARS-CoV-2 positive patients, adjusting for age, sex, individual- and area-level SES. RESULTS: Of 3,721,810 people, 138,742 were infected, 11,270 hospitalized, and 2,557 died from COVID-19 during 14 months of follow-up. We detected strong positive associations with COVID-19 incidence, with hazard ratio (HR) and 95% confidence interval (CI) of 1.10 (CI: 1.05-1.14) per 0.5-µg/m3 increase in PM2.5 and 1.18 (CI: 1.14-1.23) per 3.6-µg/m3 increase in NO2. For COVID-19 hospitalizations and for COVID-19 deaths, corresponding HRs and 95% CIs were 1.09 (CI: 1.01-1.17) and 1.19 (CI: 1.12-1.27), respectively for PM2.5, and 1.23 (CI: 1.04-1.44) and 1.18 (CI: 1.03-1.34), respectively for NO2. We also found strong positive and statistically significant associations with BC and negative associations with O3. Associations were strongest in those aged 65 years old or older, participants with the lowest SES, and patients with chronic cardiovascular, respiratory, metabolic, lung cancer, and neurodegenerative disease. Among 138,742 individuals who have tested positive for SARS-Cov-2, we detected positive association with COVID-19 hospitalizations (N = 11,270) with odds ratio and 95% CI of 1.04 (CI: 1.01- 1.08) per 0.5-µg/m3 increase in PM2.5 and 1.06 (CI: 1.01-1.12) per 3.6-µg/m3 increase in NO2, but no association with PM with an aerodynamic diameter <10 µm (PM10), BC, or O3, and no association between any of the pollutants and COVID-19 mortality (N = 2,557). CONCLUSIONS: This large nationwide study provides strong new evidence in support of association between long-term exposure to air pollution and COVID-19.

Prenatal and postnatal exposures to endocrine disrupting chemicals and timing of pubertal onset in girls and boys: a systematic review and meta-analysis.

BACKGROUND: Globally, the ages at pubertal onset for girls and boys have been decreasing during recent decades, partly attributed to excess body fat accumulation. However, a growing body of literature has recognized that endocrine disrupting chemicals (EDCs) may play an important role in this global trend, but the association has not yet been fully established. OBJECTIVE AND RATIONALE: EDCs can interfere with normal hormone function and metabolism and play a role in pubertal onset. We aimed to systematically identify and evaluate the current evidence on the timing of pubertal onset in girls and boys following prenatal or postnatal exposures to xenobiotic EDCs. SEARCH METHODS: Following PRISMA guidelines, we performed a systematic literature search of original peer-reviewed publications in the PubMed database through a block search approach using a combination of index MeSH and free text search terms. Publications were considered if they covered biomarkers of prenatal or postnatal exposures to xenobiotic EDCs (European Commission's list of category 1 EDCs) measured in maternal or child biospecimen and pubertal onset defined by the progression of the following milestones (and assessed in terms of the following measures): menarche (age), thelarche (Tanner staging) and pubarche (Tanner staging), in girls, and genital stage (Tanner staging), testicular volume (ml) and pubarche (Tanner staging), in boys. OUTCOMES: The literature search resulted in 703 references, of which we identified 52 publications fulfilling the eligibility criteria for the qualitative trend synthesis and 23 publications for the meta-analysis. The qualitative trend synthesis provided data on 103 combinations of associations between prenatal or postnatal exposure to EDC compounds groups and puberty outcomes and the meta-analysis enabled 18 summary risk estimates of meta-associations. WIDER IMPLICATIONS: Statistically significant associations in the qualitative trend synthesis suggested that postnatal exposure to phthalates may be associated with earlier thelarche and later pubarche. However, we did not find consistent evidence in the meta-analysis for associations between timing of pubertal onset in girls and boys and exposures to any of the studied xenobiotic EDCs. We were not able to identify specific pre- or postnatal windows of exposure as particularly critical and susceptible for effects of EDCs. Current evidence is subject to several methodological challenges and inconsistencies and evidence on specific exposure-outcome associations remains too scarce to firmly confirm EDC exposure as a risk factor for changes in age of pubertal onset in the general child population. To create a more uniform foundation for future comparison of evidence and to strengthen pooled studies, we recommend the use of more standardized approaches in the choice of statistical analyses, with exposure transformations, and in the definitions and assessments of puberty outcomes. The impact of mixtures of EDC exposures on the association also remains unestablished and would be valuable to elucidate for prenatal and postnatal windows of exposure. Future large, longitudinal epidemiological studies are needed to clarify the overall association.

Ultrafine particle exposure for bicycle commutes in rush and non-rush hour traffic: A repeated measures study in Copenhagen, Denmark.

Ultrafine particles (UFP), harmful to human health, are emitted at high levels from motorized traffic. Bicycle commuting is increasingly encouraged to reduce traffic emissions and increase physical activity, but higher breathing rates increase inhaled UFP concentrations while in traffic. We assessed exposure to UFP while cycling along a fixed 8.5 km inner-city route in Copenhagen, on weekdays over six weeks (from September to October 2020), during morning and afternoon rush-hour, as well as morning non-rush-hour, traffic time periods starting from 07:45, 15:45, and 09:45 h, respectively. Continuous measurements were made (each second) of particle number concentration (PNC) and location. PNC levels were summarized and compared across time periods. We used generalized additive models to adjust for meteorological factors, weekdays and trends. A total of 61 laps were completed, during 28 days (∼20 per time period). Overall mean PNC was 18,149 pt/cm3 (range 256-999,560 pt/cm3) with no significant difference between morning rush-hour (18003 pt/cm3), afternoon rush-hour (17560 pt/cm3) and late morning commute (17560 pt/cm3) [p = 0.85]. There was substantial spatial variation of UFP exposure along the route with highest PNC levels measured at traffic intersections (∼38,000-42000 pt/cm3), multiple lane roads (∼38,000-40000 pt/cm3) and construction sites (∼44,000-51000 pt/cm3), while lowest levels were measured at smaller streets, areas with open built environment (∼12,000 pt/cm3), as well as at a bus-only zone (∼15,000 pt/cm3). UFP exposure in inner-city Copenhagen did not differ substantially when bicycling in either rush-hour or non-rush-hour, or morning or afternoon, traffic time periods. UFP exposure varied substantially spatially, with highest concentrations around intersections, multiple lane roads, and construction sites. This suggests that exposure to UFP is not necessarily reduced by avoiding rush-hours, but by avoiding sources of pollution along the bicycling route.

Exposure to ultrafine particles while walking or bicycling during COVID-19 closures: A repeated measures study in Copenhagen, Denmark.

Ultrafine particles (UFP; particulate matter <0.1 µm diameter) emitted from motorized traffic may be highly detrimental to health. Active mobility (walking, bicycling) is increasingly encouraged as a way to reduce traffic congestion and increase physical activity levels. However, it has raised concerns of increased exposure to UFP, due to increased breathing rates in traffic microenvironments, immediately close to their source. The recent Coronavirus Disease 2019 (COVID-19) societal closures reduced commuting needs, allowing a natural experiment to estimate contributions from motorized traffic to UFP exposure while walking or bicycling. From late-March to mid-July 2020, UFP was repeatedly measured while walking or bicycling, capturing local COVID-19 closure ('Phase 0') and subsequent phased re-opening ('Phase 1', '2', '2.1' & '3'). A DiSCmini continuously measured particle number concentration (PNC) in the walker/bicyclist's breathing zone. PNC while walking or bicycling was compared across phased re-openings, and the effect of ambient temperature, wind speed and direction was determined using regression models. Approximately 40 repeated 20-minute walking and bicycling laps were made over 4 months during societal re-opening phases related to the COVID-19 pandemic (late-March to mid-July 2020) in Copenhagen. Highest median PNC exposure of both walking (13,170 pt/cm3, standard deviation (SD): 3560 pt/cm3) and bicycling (21,477 pt/cm3, SD: 8964) was seen during societal closures (Phase 0) and decreased to 5367 pt/cm3 (SD: 2949) and 8714 pt/cm3 (SD: 4309) in Phase 3 of re-opening. These reductions in PNC were mainly explained by meteorological conditions, with most of the deviation explained by wind speed (14-22%) and temperature (10-13%). Highest PNC was observed along major roads and intersections. In conclusion, we observed decreases in UFP exposure while walking and bicycling during societal re-opening phases related to the COVID-19 pandemic, due largely to meteorological factors (e.g., wind speed and temperature) and seasonal variations in UFP levels.

Eliminating artifacts in single-grid phase-contrast x-ray imaging for improving image quality.

In this study, we propose a modification to a single-grid phase-contrast x-ray imaging (PCXI) system using a Fourier domain analysis technique to extract absorption, scattering, and differential phase-contrast images. The proposed modification is to rotate the x-ray grid in the image plane to achieve spectral separation between the desired information and the moiré artifact, which is introduced by the superposition of the periodic image of the grid shadow and the periodic sampling by the detector. In addition, we performed some system optimization by adjusting distances between source, object, grid, and detector to further improve image quality. This optimization aimed to increase the spectral spacing between the primary spectrum (lower frequency) and the harmonics of the spectrum (higher frequency) used to extract the various image contrasts. The table-top setup used in the experiment consisted of a focused-linear grid with a 200-lines/inch strip density, a microfocus x-ray tube with a 55-µm focal spot size, and a CMOS flat-panel detector with a 49.5-µm pixel size. The x-ray grid was rotated at 27.8° with respect to the detector and the sample was placed as close as possible to the x-ray tube. Our results indicated that the proposed method effectively eliminated the PCXI artifacts, thus improving image quality.

Probing the molecular determinants of fluorinase specificity.

Molecular determinants of FlA1 fluorinase specificity were probed using 5'-chloro-5'-deoxyadenosine (5'-ClDA) analogs as substrates and FlA1 active site mutants. Modifications at F213 or A279 residues are beneficial towards these modified substrates, including 5'-chloro-5'-deoxy-2-ethynyladenosine, ClDEA (>10-fold activity improvement), and conferred novel activity towards substrates not readily accepted by wild-type FlA1.

Cutaneous skeletal hypophosphatemia syndrome: clinical spectrum, natural history, and treatment.

Cutaneous skeletal hypophosphatemia syndrome (CSHS), caused by somatic RAS mutations, features excess fibroblast growth factor-23 (FGF23) and skeletal dysplasia. Records from 56 individuals were reviewed and demonstrated fractures, scoliosis, and non-congenital hypophosphatemia that in some cases were resolved. Phosphate and calcitriol, but not skin lesion removal, were effective at controlling hypophosphatemia. No skeletal malignancies were found. PURPOSE: CSHS is a disorder defined by the association of epidermal and/or melanocytic nevi, a mosaic skeletal dysplasia, and an FGF23-mediated hypophosphatemia. To date, somatic RAS mutations have been identified in all patients whose affected tissue has undergone DNA sequencing. However, the clinical spectrum and treatment are poorly defined in CSHS. The purpose of this study is to determine the spectrum of the phenotype, natural history of the disease, and response to treatment of hypophosphatemia. METHODS: Five CSHS subjects underwent prospective data collection at clinical research centers. A review of the literature identified 45 reports that included a total of 51 additional patients, in whom the findings were compatible with CSHS. Data on nevi subtypes, bone histology, mineral and skeletal disorders, abnormalities in other tissues, and response to treatment of hypophosphatemia were analyzed. RESULTS: Fractures, limb deformities, and scoliosis affected most CSHS subjects. Hypophosphatemia was not present at birth. Histology revealed severe osteomalacia but no other abnormalities. Skeletal dysplasia was reported in all anatomical compartments, though less frequently in the spine; there was no clear correlation between the location of nevi and the skeletal lesions. Phosphate and calcitriol supplementation was the most effective therapy for rickets. Convincing data that nevi removal improved blood phosphate levels was lacking. An age-dependent improvement in mineral abnormalities was observed. A spectrum of extra-osseous/extra-cutaneous manifestations that included both benign and malignant neoplasms was present in many subjects, though osteosarcoma remains unreported. CONCLUSION: An understanding of the spectrum, natural history, and efficacy of treatment of hypophosphatemia in CSHS may improve the care of these patients.

In vitro assessment of the gastrointestinal tolerance and immunomodulatory function of Bacillus methylotrophicus isolated from a traditional Korean fermented soybean food.

AIMS: This study aimed to investigate the potential of Bacillus methylotrophicus as a probiotic. METHODS AND RESULTS: A Bacillus isolate designated strain C14 was isolated from Korean traditional fermented soybean paste (doenjang). The strain was identified, and its physiological and biochemical properties were characterized. The gastrointestinal tolerance and immunomodulatory function of strain C14 were also investigated. Strain C14 was identified as B. methylotrophicus by analysis of its biochemical properties using the API 50CHB system and by phylogenetic analysis of the 16S rDNA sequence. Strain C14 showed >80% and >75% of survival for artificial gastric juices (pH 2.5 and 1% pepsin) and 0.5% (w/v) bile salt, respectively. Heat-killed B. methylotrophicus C14 inhibited the adhesion of various pathogens and enhanced the adhesion of probiotic bacteria to Caco-2 cells. The heat-killed cells also induced high levels of immune cell proliferation compared with the control and stimulated interleukin-6 and tumour necrosis factor-α production in mouse macrophages. CONCLUSIONS: Bacillus methylotrophicus C14 could be used as a probiotic. SIGNIFICANCE AND IMPACT OF THE STUDY: Recently identified B. methylotrophicus is a new potential probiotic with high gastrointestinal tolerance.

Purification and functional characterization of the first stilbene glucoside-specific ß-glucosidase isolated from Lactobacillus kimchi.

This study aimed to develop viable enzymes for bioconversion of resveratrol-glucoside into resveratrol. Out of 13 bacterial strains tested, Lactobacillus kimchi JB301 could completely convert polydatin into resveratrol. The purified enzyme had an optimum temperature of 30-40°C and optimum pH of pH 5.0 against polydatin. This enzyme showed high substrate specificities towards different substrates in the following order: isorhaponticin>>polydatin>>mulberroside A>oxyresveratrol-3-O-glucoside. Additionally, it rarely hydrolyzed astringin and desoxyrhaponticin. Based on these catalytic specificities, we suggest this enzyme be named stilbene glucoside-specific ß-glucosidase. Furthermore, polydatin extracts from Polygonum cuspidatum were successfully converted to resveratrol with a high yield (of over 99%). Stilbene glucoside-specific ß-glucosidase is the first enzyme isolated from lactic acid bacteria capable of bio-converting various stilbene glucosides into stilbene.

HDL-C levels modify the association between C-reactive protein and coronary artery calcium score.

BACKGROUNDS AND AIMS: C-reactive protein (CRP) levels predict incident and recurrent cardiovascular disease (CVD) events; however, associations between CRP and pre-clinical atherosclerosis is less certain. Since high concentrations of high-density lipoprotein cholesterol (HDL-C) are inversely associated with CVD risk, we investigated whether HDL-C modified the association between CRP concentration and measures of preclinical atherosclerosis. METHODS AND RESULTS: Data were analyzed from a Korean occupational cohort of 12,030 male subjects who underwent a cardiac computed tomography (CT) estimation of coronary artery calcification (CAC) score and an assessment of CVD risk factors. Logistic regression was used to describe associations between CRP and measures of pre-clinical atherosclerosis, such as CAC scores >0. As many as 1351 (11.2%) participants had a CAC score>0. CRP was stratified into 3 groups based on clinical category: <1 mg/L, 1 to <2 mg/L, and ≥ 2 mg/dL. In the bottom CRP group, 907/8697 (10.4%) of subjects had a CAC score >0, compared with 242/1943 (12.5%) in the middle group and 202/1396 (14.5%) in the top CRP group (p < 0.0001). After adjustment for multiple CVD risk factors, there was a positive association between CRP and CAC score>0 (OR between top and bottom CRP groups, 1.41 [1.04, 1.90], p = 0.027) in the lowest HDL-C quartile but not in the highest HDL-C (OR between top and bottom CRP group, 0.80 [0.46, 1.39], p = 0.425). CONCLUSION: The association between CRP concentration and CAC score differed according to HDL-C levels.

Within-visit blood pressure variability: relevant factors in the general population.

The objective of this study was to use a nationwide epidemiological survey to investigate the factors that affect within-visit blood pressure (BP) variability. We analyzed the Korean National Health and Nutrition Examination Survey (KNHNES) data for 2005 (n=5488). We examined three within-visit BP variability parameters that include the following: the alarm reaction (AR), defined as the first BP reading minus the third BP reading; the BP discrepancy, defined as the maximal BP reading minus the minimal BP reading (ΔBPmax); and the s.d. (BPSD). Age, fasting glucose, eGFR, total cholesterol, LDL cholesterol, and the metabolic syndrome (MetS) score were the relevant factors that affected the systolic AR, ΔSBPmax and SBPSD. Multiple linear regression models revealed that age (P<0.0001), the office systolic BP (SBP) level (P<0.0001), the MetS score (P<0.0001), the female gender (P=0.007) and the eGFR (P=0.049) were independently associated with the systolic AR, whereas age (P<0.0001), the office SBP level (P<0.0001), and the female gender (P=0.024 and 0.022) were independently associated with ΔSBPmax and SBPSD, respectively. Within-visit BP variability, especially the variability associated with the SBP, was significantly associated with increased age, female gender and cardiovascular risk factors, such as hypertension, low eGFR and adverse glucose and lipid profiles. In addition, increased age, female gender, the eGFR and the MetS score were independently relevant factors that affected the systolic AR. Systolic within-visit BP variability and systolic AR are associated with cardiovascular risk factors.

Heterochronic protein expression patterns in the developing embryonic chick cerebellum.

The advantages of the embryonic chick as a model for studying neural development range from the relatively low cost of fertilized eggs to the rapid rate of development. We investigated in ovo cerebellar development in the chick, which has a nearly identical embryonic period as the mouse (19-22 days). We focused on three antigens: Calbindin (CB), Zebrin II (ZII), and Calretinin (CR), and our results demonstrate asynchronous expression patterns during cerebellar development. Presumptive CB+ Purkinje cells are first observed at embryonic day (E)10 in clusters in posterior cerebellum. At E12, corresponding with global expression of CB across the cerebellum, Purkinje cells began to express ZII. By E14-E16, Purkinje cells disperse into a monolayer and develop a pattern of alternating immunopositive and immunonegative ZII stripes. CR is initially expressed by clusters of presumptive Purkinje cells in the nodular zone at E8. However, this expression is transient and at later stages, CR is largely confined to the granule and molecular layers. Before hatch (E18-E20), Purkinje cells adopt a morphologically mature phenotype with complex dendritic arborizations. Comparing this data to that seen in mice, we found that the sequence of Purkinje cell formation, protein expression, and development is similar in both species, but these events consistently begin ∼5-7 days earlier in the precocial chick cerebellum, suggesting an important role for heterochrony in neurodevelopment.

Pantothenate kinase-associated neurodegeneration in Korea: recurrent R440P mutation in PANK2 and outcome of deep brain stimulation.

BACKGROUND AND PURPOSE: The purpose of this study was to evaluate the mutation status of PANK2 among Korean patients with pantothenate kinase-associated neurodegeneration (PKAN) and to document the outcome of pallidal deep brain stimulation (DBS). METHODS: Direct sequencing and deletion/duplication analysis of PANK2 were conducted in 12 patients (11 unrelated) with PKAN, diagnosed on the basis of extrapyramidal dysfunction and the 'eye-of-the-tiger sign' on brain magnetic resonance imaging (MRI). Pallidal DBS was conducted in four patients, and the outcomes were measured using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). RESULTS: A PANK2 mutation was identified in both alleles in all patients. The most prevalent mutation was c.1319G>C (p.R440P) in 8/22 mutated alleles (36%). An intragenic deletion ranging from exons 2 to 4 was found in one allele (1/22, 4.5%) using deletion/duplication analysis. The outcome of pallidal DBS was favorable in two patients with atypical PKAN and moderate severity of dystonia. However, two patients with typical PKAN and relatively severe symptoms showed variable responses. CONCLUSIONS: The c.1319G>C (p.R440P) mutation appears to be a founder genotype among Korean patients with PKAN. Furthermore, this study provides additional data for the recent international effort to evaluate the efficacy of pallidal DBS in the treatment of patients with PKAN.

A placental phenotype for intrahepatic cholestasis of pregnancy.

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy specific liver disease associated with significant risk of fetal complications. It is hypothesised that the risk of adverse fetal outcomes relates to the toxic effects of bile acids, the levels of which are increased in both maternal and fetal serum. Human and rodent studies have shown that transplacental transfer of bile acids is impaired in ICP. Furthermore, the morphology of placentas from the rodent model of ICP is markedly abnormal, and is associated with increased expression of apoptotic markers and oxidative stress. Using placental tissue from ICP cases and normal pregnancies and cultured placental explant fragments we investigated the histological and molecular effects of cholestasis. We also examined the influence of ursodeoxycholic acid (UDCA) administration on these parameters. Here we report that ICP is associated with several morphological abnormalities of the placenta, including an increase in the number of syncytial knots, and that these can be reproduced in an in vitro (explant) model exposed to the bile acids taurocholic acid and taurochenodoexycholic acid. Furthermore, we demonstrate that ursodeoxycholic acid, a drug commonly used in the management of ICP, has a protective effect on placental tissue both in vivo and in vitro.

Environmental surveillance and molecular characterization of Legionella in tropical Singapore.

Legionnaires' disease is often acquired by inhalation of legionellae from a contaminated environmental source. In recent years, Singapore has seen an increase in the use of aerosol-generating fixtures such as mist fans and spa pools. Poorly maintained and designed water fixtures could pose a public health threat to the community. In this study, we provided an update on the prevalence of Legionella in mist fans (N=28), household water heaters with storage tanks (N=19) and instantaneous heaters (N=30); and extended the survey to spa pools (N=29) and aerosol-generating fixtures in nursing homes (N=116). The prevalence of Legionella were 21.1% in water heaters with storage tanks, 24.1% in spa pools, 14.2% in mist fans and 3.3% in instantaneous heaters. Legionella was not detected in nursing homes. A total of 37 isolates were subjected to molecular characterization using Sequence-Based Typing (SBT) protocol from the European Working Group on Legionella Infections (EWGLI). This is the first study on the use of SBT protocol on environmental strains isolated from tropical South East Asia. The Legionella flora was very heterogenous. The overall diversity of the allelic profile was found to be 0.970 (95% CI 0.946 - 0.994). All known STs of our isolates have been associated with clinical cases in EWGLI database. The phylogenetic analysis showed that our novel environmental isolates were clustered with clinical STs that were previously reported in Europe, Japan, United Kingdom and United States etc. (in EWGLI database), suggesting that Legionella found in the environment of Singapore may potentially cause human disease.

Spectral entropy monitoring allowed lower sevoflurane concentration and faster recovery in children.

BACKGROUND: Anesthetic titration using spectral entropy monitoring reduces anesthetic requirements and shortens recovery in adult surgical patients. This study was performed to evaluate the effect of entropy monitoring on end-tidal sevoflurane concentration and recovery characteristics in pediatric patients undergoing sevoflurane anesthesia. METHODS: Seventy-eight children (aged 3-12 years) scheduled for a tonsillectomy and/or an adenoidectomy were randomly divided into one of two groups: standard practice (Standard) or entropy-guided (Entropy). In the Standard group, sevoflurane was adjusted to maintain the heart rate and systolic blood pressure (BP) within 20% of the baseline values. In the Entropy group, sevoflurane was adjusted to achieve a state entropy of 40-50. We compared the entropy values, end-tidal sevoflurane concentration and recovery times between groups. RESULTS: During maintenance of anesthesia, the entropy and BP values were higher in the Entropy group (P<0.05). The end-tidal sevoflurane concentration during maintenance was lower in the Entropy group (2.2 (0.3) vol%) compared with the Standard group (2.6 (0.4) vol%) (P<0.05). Recovery times were faster in the Entropy group (P<0.05). CONCLUSIONS: Compared with standard practice, we found that entropy-guided anesthetic administration was associated with a reduced sevoflurane concentration and a slightly faster emergence and recovery in 3-12-year-old children.

Herbal use amongst multiethnic medical patients in Penang Hospital: pattern and perceptions.

A cross sectional survey on pattern and perception of herbal use among medical patients in Penang Hospital was conducted. Among 250 patients surveyed, 67.9% were using herbal medicine and conventional medicine concomitantly. A majority of the patients used herbs for health maintenance (51.3%) purpose. More than 90% of herbal users did not disclose herbal use to their physician and "Doctor never asked" was the major reason given (54.2%). The Chinese reported the highest rate of herbal use but was least likely to disclose. These findings are important for health professionals to ensure medication safety and recognise potential drug herb interaction.

Identification of a novel HLA-DRB1*12 allele (DRB1*1210) in the Korean population.

At least 11 HLA-DRB1*12 alleles have been identified to date. We report a new HLA-DRB1*12 allele, DRB1*1210, that was identified in the Korean population. This new allele differs from HLA-DRB1*120101 by a single nucleotide at position 40 (G-->A) in exon 1 that falls within codon--16 (GTT-->ATT). This change results in a single valine to isoleucine amino acid alteration.

Combined effects of ionizing-irradiation and different environments on Clostridium botulinum type E spores.

We examined the combined effects of gamma-radiation (24 degrees C) on spores of Clostridium botulinum-type Eklund strain suspended in different gas-saturated Na-phosphate buffer in absence or presence of protectors or sensitizers. Response surface methodology (RSM) was also used to ascertain the effects of radiation on the recovery of spores using a medium containing various levels of NaCl or Na-thioglycollate. The former (< 0.5%) decreased viable spore counts, but the latter (0.15%) did not. Irradiation inactivation of Eklund spores was most effective in air-saturated buffers compared to N2O and N2 gas. The Na2-EDTA (0.01 M) was the most efficient radioprotector of spores due to its reactivity toward hydroxy radicals, followed by t-butanol (0.1 M) in NO2 or N(2)-saturated buffers, respectively. Catalase (10.0 mg ml(-1)) and DL-cysteine (0.1 mM) sensitized the spores during irradiated N2O or N(2)-saturated buffers, and NaCl (0.01 M) only sensitized spores in N2 environment. Spores frozen at -75 degrees C for 30 days and thawed prior to use were more sensitive to radiation damage compared to freshly prepared spores. Glycerol (15%), in Na-phosphate buffer (pH 7.0, 0.06 M), protected Eklund spores and increased the number of spores from 10(6) to 10(11) colony forming unit (CFU) ml(-1), and enhanced their radiosensitivities. Seven strains of C. botulinum type E were screened for plasmids and strain BL764 had two plasmids (15.8 and 46.8 mDa), BL4028 also had two (4.4 and 13.2 mDa), BL4850 contained only one (4.9 mDa), whereas EQA, BL211, Eklund, and Beluga had none. Gamma-Radiation (10 kGy, absorbed dose) cured the 15.8-mDa plasmid in strain BL764, but its absence yielded no changes in toxigenicity.

Identification of essential amino acid residues for catalytic activity and thermostability of novel chitosanase by site-directed mutagenesis.

The functional importance of a conserved region in a novel chitosanase from Bacillus sp. CK4 was investigated. Each of the three carboxylic amino acid residues (Glu-50, Glu-62, and Asp-66) was changed to Asp and Gln or Asn and Glu by site-directed mutagenesis, respectively. The Asp-66-->Asn and Asp-66-->Glu mutation remarkably decreased kinetic parameters such as Vmax and kcat to approximately 1/1,000 those of the wild-type enzyme, indicating that the Asp-66 residue was essential for catalysis. The thermostable chitosanase contains three Cys residues at positions 49, 72, and 211. The Cys-49-->Ser/Tyr and Cys-72-->Ser/Tyr mutant enzymes were as stable to thermal inactivation and denaturating agents as the wild-type enzyme. However, the half-life of the Cys-211-->Ser/Tyr mutant enzyme was less than 10 min at 80 degrees C, while that of the wild-type enzyme was about 90 min. Moreover, the residual activity of Cys-211-->Ser/Tyr enzyme was substantially decreased by 8 M urea; and it lost all catalytic activity in 40% ethanol. These results show that the substitution of Cys with any amino acid residues at position 211 seems to affect the conformational stability of the chitosanase.