Prevalence of occupational heat stress across the seasons and its management amongst healthcare professionals in the UK

Occupational heat stress (OHS) is an issue in healthcare facilities (HCFs) in the United Kingdom (UK). The aims of this study were to evaluate perceived levels of OHS during two seasons and its perceived consequences on healthcare professionals (HCPs) and to assess the efficacy of heat stress management (HSM) policies. An anonymous online survey was distributed to HCPs working in HCFs in the UK. The survey returned 1014 responses (87% women). Descriptive statistics and content analysis of survey data identified that OHS in HCFs is frequently experienced throughout the year and concerned most HCPs. Over 90% perceived OHS impairs their performance and 20% reported heat-related absenteeism. Awareness of HSM policies was poor and 73% deemed them not adequate. To help reduce the financial loss and impact on staff performance, health and well-being and patient safety, it is recommended that revisions and widespread dissemination of HSM policies are made.

Molecular biomarkers for assessing the heat-adapted phenotype: a narrative scoping review

Heat acclimation/acclimatisation (HA) mitigates heat-related decrements in physical capacity and heat-illness risk and is a widely advocated countermeasure for individuals operating in hot environments. The efficacy of HA is typically quantified by assessing the thermo-physiological responses to a standard heat acclimation state test (i.e. physiological biomarkers), but this can be logistically challenging, time consuming, and expensive. A valid molecular biomarker of HA would enable evaluation of the heat-adapted state through the sampling and assessment of a biological medium. This narrative review examines candidate molecular biomarkers of HA, highlighting the poor sensitivity and specificity of these candidates and identifying the current lack of a single 'standout' biomarker. It concludes by considering the potential of multivariable approaches that provide information about a range of physiological systems, identifying a number of challenges that must be overcome to develop a valid molecular biomarker of the heat-adapted state, and highlighting future research opportunities.

Changes in physical performance during British Army Junior Entry, British Army Standard Entry and Royal Air Force Basic Training

INTRODUCTION

The purpose was to quantify physical performance in men and women during British Army Junior Entry (Army-JE), British Army Standard Entry (Army-SE) and Royal Air Force (RAF) basic training (BT).

DESIGN

Prospective longitudinal study.

METHODS

381 participants ((339 men and 42 women) n=141 Army-JE, n=132 Army-SE, n=108 RAF) completed a 2 km run, medicine ball throw (MBT) and isometric mid-thigh pull (MTP), pre-BT and post-BT. To examine changes in pre-BT to post-BT physical test performance, for each course, paired Student t-test and Wilcoxon test were applied to normally and non-normally distributed data, respectively, with effect sizes reported as Cohen's D and with rank biserial correlations, respectively. A one-way between-subjects analysis of variance (ANOVA) (or Welch ANOVA for non-normally distributed data) compared performance between quartiles based on test performance pre-BT. Where the main tests statistic, p value and effect sizes identified likely effect of quartile, post hoc comparisons were made using Games-Howell tests with Tukey's p value. Data are presented as mean±SD, with statistical significance set at p<0.05.

RESULTS

During BT, 2 km run time improved by 13±46 s (-2.1%±8.1%), 30±64 s (-4.8%±12.3%) and 24±27 s (-4.5%±5.1%) for Army-JE, Army-SE and RAF, respectively (all p<0.005). MBT distance increased by 0.27±0.28 m (6.8%±7.0%) for Army-JE (p<0.001) and 0.07±0.46 m (2.3%±10.9%) for Army-SE (p=0.040), but decreased by 0.08±0.27 m (-1.4%±6.0%) for RAF (p=0.002). MTP force increased by 80±281 n (10.8%±27.6%) for Army-JE (p<0.001) and did not change for Army-SE (-36±295 n, -0.7%±20.6%, p=0.144) or RAF (-9±208 n, 1.0±17.0, p=0.603). For all tests and cohorts, participants in the lowest quartile of pre-BT performance scores demonstrated greater improvements, compared with participants in the highest quartile (except Army-JE MBT, ∆% change similar between all quartiles).

CONCLUSIONS

Changes in physical performance were observed for the three fitness tests following the different BT courses, and recruits with the lowest strength and aerobic fitness experienced greatest improvements.

Validation of the Anti-Inflammatory Effect of Tenebrio Molitor Larva Oil in a Colitis Mouse Model

Ulcerative colitis is caused by various external factors and is an inflammatory disease that causes decreased intestinal function. Tenebrio molitor larvae contain more than 30 % fat, and the fat component consists of 45 % oleic acid, 20 % linoleic acid and 20 % polyunsaturated fatty acids. In this study, after administering Tenebrio molitor larva oil (TMLO) in a dextran sodium sulphate (DSS)-induced ulcerative colitis mouse model, the pathological findings and inflammatory markers of colitis were analysed to assess whether a colitis mitigation effect was achieved. In the TMLO-administered group, the colon length increased, the spleen weight decreased, and the body weight increased compared with that in the DSS group. In addition, the disease activity index level decreased, the mRNA expression level of inflammatory cytokines in the colon decreased, and the myeloperoxidase activity level significantly decreased. Also, the activity of the NF-κB pathway involved in the regulation of the inflammatory response was lower in the TMLO group than in the DSS group. Taken together, these results suggest that TMLO suppresses occurrence of acute ulcerative colitis in the DSS mouse model. Therefore, TMLO has the potential to be developed as a health food for the prevention and treatment of ulcerative colitis.

Role of the urinary N-acetyl-beta-D-glucosaminidase/creatinine (NAG/Cr) ratio in discriminating between true and false pyuria in sterile urine bag specimens

INTRODUCTION

Urethral catheterization (CATH) and suprapubic aspiration (SA) are reliable methods of collecting urine for the diagnosis of urinary tract infections (UTIs), but both are invasive and difficult. Therefore, urine collection through a sterile urine bag (SUB) is commonly used for UTI screening. However, when pyuria is found in SUB specimens, it is difficult to interpret whether this result is true or false.

OBJECTIVE

We aimed to determine the diagnostic performance of the urinary NAG/Cr ratio in detecting true pyuria in SUB specimens for children with suspected UTIs.

STUDY DESIGN

This retrospective study included children 2-24 months of age presenting to the pediatric emergency department (PED) and in whom urinary NAG and creatinine levels were measured and a urine culture was performed between January 1, 2018, and December 31, 2019. Children with the presence of pyuria in SUB specimens were categorized into true or false pyuria groups depending on whether pyuria was present in CATH specimens. The diagnostic performance of the urinary NAG/Cr ratio in detecting true pyuria was identified using receiver operating characteristic (ROC) curve analysis. The optimal cutoff was calculated based on ROC curve analysis. Sensitivity, specificity, and positive and negative likelihood ratios were assessed for optimal cutoff values.

RESULTS

Among 606 children with measured urinary NAG levels, 144 children with pyuria in SUB specimens were included in the analyses. Pyuria was consistently present in the CATH specimens of 67 (46.5%) children and absent in those of 77 (44.5%) children. The urinary NAG/Cr ratio was significantly higher in the true pyuria group than in the false pyuria group (21.5 IU/g; 95% confidence interval [CI]: 12.3-35.6; vs 9.6 IU/g; 95% CI: 6.7-16.1, P < 0.001). The area under the ROC curve (AUC) for the urinary NAG/Cr ratio was 0.776 (95% CI: 0.700-0.851). The optimal cutoff of 18.85 IU/g corresponded to the best combination of sensitivity (58.2, 95% CI: 46.4-70.0) and specificity (83.3, 95% CI: 74.7-91.6), with positive and negative likelihood ratios of 3.49 (95% CI: 2.04-5.97) and 0.50 (95% CI: 0.37-0.68), respectively.

CONCLUSION

The urinary NAG/Cr ratio may be a potential indicator discriminating true pyuria from false pyuria in SUB specimens in the PED. However, large prospective studies are required to implement the NAG/Cr ratio in clinical practice.

Structural and functional studies of SAV1707 from Staphylococcus aureus elucidate its distinct metal-dependent activity and a crucial residue for catalysis

The metallo-β-lactamase fold is the most abundant metal-binding domain found in two major kingdoms: bacteria and archaea. Despite the rapid growth in genomic information, most of these enzymes, which may play critical roles in cellular metabolism, remain uncharacterized in terms of structure and function. In this study, X-ray crystal structures of SAV1707, a hypothetical metalloenzyme from Staphylococcus aureus, and its complex with cAMP are reported at high resolutions of 2.05 and 1.55 Å, respectively, with a detailed atomic description. Through a functional study, it was verified that SAV1707 has Ni²⁺-dependent phosphodiesterase activity and Mn²⁺-dependent endonuclease activity, revealing a different metal selectivity depending on the reaction. In addition, the crystal structure of cAMP-bound SAV1707 shows a unique snapshot of cAMP that reveals the binding mode of the intermediate, and a key residue Phe511 that forms π-π interactions with cAMP was verified as contributing to substrate recognition by functional studies of its mutant. Overall, these findings characterized the relationship between the structure and function of SAV1707 and may provide further understanding of metalloenzymes possessing the metallo-β-lactamase fold.

FCC to BCC transformation-induced plasticity based on thermodynamic phase stability in novel V10Cr10Fe45CoxNi35-x medium-entropy alloys

We introduce a novel transformation-induced plasticity mechanism, i.e., a martensitic transformation from fcc phase to bcc phase, in medium-entropy alloys (MEAs). A VCrFeCoNi MEA system is designed by thermodynamic calculations in consideration of phase stability between bcc and fcc phases. The resultantly formed bcc martensite favorably contributes to the transformation-induced plasticity, thereby leading to a significant enhancement in both strength and ductility as well as strain hardening. We reveal the microstructural evolutions according to the Co-Ni balance and their contributions to a mechanical response. The Co-Ni balance plays a leading role in phase stability and consequently tunes the cryogenic-temperature strength-ductility balance. The main difference from recently-reported metastable high-entropy dual-phase alloys is the formation of bcc martensite as a daughter phase, which shows significant effects on strain hardening. The hcp phase in the present MEA mostly acts as a nucleation site for the bcc martensite. Our findings demonstrate that the fcc to bcc transformation can be an attractive route to a new MEA design strategy for improving cryogenic strength-ductility.

Stemmed DNA nanostructure for the selective delivery of therapeutics

DNA has emerged as a biocompatible biomaterial that may be considered for various applications. Here, we report tumor cell-specific aptamer-modified DNA nanostructures for the specific recognition and delivery of therapeutic chemicals to cancer cells. Protein tyrosine kinase (PTK)7-specific DNA aptamer sequences were linked to 15 consecutive guanines. The resulting aptamer-modified product, AptG15, self-assembled into a Y-shaped structure. The presence of a G-quadruplex at AptG15 was confirmed by circular dichroism and Raman spectroscopy. The utility of AptG15 as a nanocarrier of therapeutics was tested by loading the photosensitizer, methylene blue (MB), to the G-quadruplex as a model drug. The generated MB-loaded AptG15 (MB/AptG15) showed specific and enhanced uptake to CCRF-CEM cells, which overexpress PTK7, compared with Ramos cells, which lack PTK7, or CCRF-CEM cells treated with a PTK7-specific siRNA. The therapeutic activity of MB/AptG15 was tested by triggering its photodynamic effects. Upon 660 nm light irradiation, MB/AptG15 showed greater reactive oxygen species generation and anticancer activity in PTK7-overexpressing cells compared to cells treated with MB alone, those treated with AptG15, and other comparison groups. AptG15 stemmed DNA nanostructures have significant potential for the cell-type-specific delivery of therapeutics, and possibly for the molecular imaging of target cells.

Reduction of plasma glutathione in psychosis associated with schizophrenia and bipolar disorder in translational psychiatry

The establishment of mechanism-driven peripheral markers is important for translational psychiatry. Many groups, including ours, have addressed molecular alterations in peripheral tissues in association with symptomatic changes in major illnesses. Oxidative stress is implicated in the pathophysiology of schizophrenia (SZ) and bipolar disorder (BP) through studies of patient peripheral tissues and animal models. Although the relationship between peripheral changes and brain pathology remain elusive, oxidative stress may bridge such translational efforts. Nonetheless, the molecular substrates of oxidative stress are not well defined in mental conditions. Glutathione (GSH) is a non-enzymatic antioxidant that eliminates free radicals, and has been suggested to have a role in SZ. We performed a cross-sectional study of 48 healthy controls (CON), 52 SZ patients and 62 BP patients to compare the levels of peripheral GSH by a biochemical enzyme assay. We show a significant reduction of plasma GSH in both SZ and BP patients compared with CON. We evaluated possible influences of clinical characteristics on the level of GSH in SZ and BP. A decrease in GSH level correlated with Positive and Negative Syndrome Scale (PANSS) total and positive scores for SZ and correlated with the PANSS general for BP. Taken together, we provide evidence that SZ and BP display a common molecular signature in the reduction of peripheral GSH in the psychosis dimension.

ARD1-mediated Hsp70 acetylation balances stress-induced protein refolding and degradation

Heat shock protein (Hsp)70 is a molecular chaperone that maintains protein homoeostasis during cellular stress through two opposing mechanisms: protein refolding and degradation. However, the mechanisms by which Hsp70 balances these opposing functions under stress conditions remain unknown. Here, we demonstrate that Hsp70 preferentially facilitates protein refolding after stress, gradually switching to protein degradation via a mechanism dependent on ARD1-mediated Hsp70 acetylation. During the early stress response, Hsp70 is immediately acetylated by ARD1 at K77, and the acetylated Hsp70 binds to the co-chaperone Hop to allow protein refolding. Thereafter, Hsp70 is deacetylated and binds to the ubiquitin ligase protein CHIP to complete protein degradation during later stages. This switch is required for the maintenance of protein homoeostasis and ultimately rescues cells from stress-induced cell death in vitro and in vivo. Therefore, ARD1-mediated Hsp70 acetylation is a regulatory mechanism that temporally balances protein refolding/degradation in response to stress.

The chaperone Hsp70 has a dual role, promoting both protein refolding and protein degradation. Seo and Park et al. show that Hsp70 acetylation enhances protein refolding after stress, and that subsequent deacetylation progressively promotes ubiquitin ligase binding and protein degradation.

Overexpression of Selenoprotein SelK in BGC-823 Cells Inhibits Cell Adhesion and Migration

Effects of human selenoprotein SelK on the adhesion and migration ability of human gastric cancer BGC-823 cells using Matrigel adhesion and transwell migration assays, respectively, were investigated in this study. The Matrigel adhesion ability of BGC-823 cells that overexpressed SelK declined extremely significantly (p < 0.01) compared with that of the cells not expressing the protein. The migration ability of BGC-823 cells that overexpressed SelK also declined extremely significantly (p < 0.01). On the other hand, the Matrigel adhesion ability and migration ability of the cells that overexpressed C-terminally truncated SelK did not decline significantly. The Matrigel adhesion ability and migration ability of human embryonic kidney HEK-293 cells that overexpressed SelK did not show significant change (p > 0.05) with the cells that overexpressed the C-terminally truncated protein. In addition to the effect on Matrigel adhesion and migration, the overexpression of SelK also caused a loss in cell viability (as measured by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H tetrazolium bromide (MTT) colorimetric assay) and induced apoptosis as shown by confocal microscopy and flow cytometry. The cytosolic free Ca2+ level of these cells was significantly increased as detected by flow cytometry. But the overexpression of SelK in HEK-293 cells caused neither significant loss in cell viability nor apoptosis induction. Only the elevation of cytosolic free Ca2+ level in these cells was significant. Taken together, the results suggest that the overexpression of SelK can inhibit human cancer cell Matrigel adhesion and migration and cause both the loss in cell viability and induction of apoptosis. The release of intracellular Ca2+ from the endoplasmic reticulum might be a mechanism whereby the protein exerted its impact. Furthermore, only the full-length protein, but not C-terminally truncated form, was capable of producing such impact. The embryonic cells were not influenced by the elevation of free Ca2+ level in cytosol, probably due to their much greater tolerance to the variation.

A comparison of two commercially available ELISA methods for the quantification of human plasma heat shock protein 70 during rest and exercise stress

This study compared resting and exercise heat/hypoxic stress-induced levels of plasma extracellular heat shock protein 70 (eHSP70) in humans using two commercially available enzyme-linked immunosorbent assay (ELIS)A kits. EDTA plasma samples were collected from 21 males during two separate investigations. Participants in part A completed a 60-min treadmill run in the heat (HOT70; 33.0 ± 0.1 °C, 28.7 ± 0.8 %, n = 6) at 70 % V̇O2max. Participants in part B completed 60 min of cycling exercise at 50 % V̇O2max in either hot (HOT50; 40.5 °C, 25.4 relative humidity (RH)%, n = 7) or hypoxic (HYP50; fraction of inspired oxygen (FIO2) = 0.14, 21 °C, 35 % RH, n = 8) conditions. Samples were collected prior to and immediately upon termination of exercise and analysed for eHSP70 using EKS-715 high-sensitivity HSP70 ELISA and new ENZ-KIT-101 Amp'd(™) HSP70 high-sensitivity ELISA. ENZ-KIT was superior in detecting resting eHSP70 (1.54 ± 3.27 ng · mL(-1); range 0.08 to 14.01 ng · mL(-1)), with concentrations obtained from 100 % of samples compared to 19 % with EKS-715 assay. The ENZ-KIT requires optimisation prior to running samples in order to ensure participants fall within the standard curve, a step not required with EKS-715. Using ENZ-KIT, a 1:4 dilution allowed for quantification of resting HSP70 in 26/32 samples, with a 1:8 (n = 3) and 1:16 (n = 3) dilution required to determine the remaining samples. After exercise, eHSP70 was detected in 6/21 and 21/21 samples using EKS-715 and ENZ-KIT, respectively. eHSP70 was increased from rest after HOT70 (p < 0.05), but not HOT50 (p > 0.05) or HYP50 (p > 0.05) when analysed using ENZ-KIT. It is recommended that future studies requiring the precise determination of resting plasma eHSP70 use the ENZ-KIT (i.e. HSP70 Amp'd(®) ELISA) instead of the EKS-715 assay, despite additional assay development time and cost required.

Influence of previous tuberculosis treatment history on acid-fast bacilli smear and culture conversion

SETTING

A teaching hospital in the Republic of Korea, 2003-2009.

OBJECTIVE

To evaluate the effect of previous tuberculosis (TB) treatment history on sputum smear and culture conversion.

DESIGN

Data, including sputum acid-fast bacilli (AFB) results at baseline and at weeks 2, 4, 8, 12, 16, 20 and 24, were collected from patients with AFB sputum smear-positive and culture-confirmed pulmonary TB. Patients with multidrug-resistant TB or those with poor adherence were excluded. AFB conversion was compared between patients with a previous history of anti-tuberculosis treatment and those without.

RESULTS

The median age of the 208 patients was 49.0 years; 58.3% were male, while 43 (20.7%) had a history of previous anti-tuberculosis treatment. Patients with a history of previous treatment had significantly lower sputum smear-negative conversion at 2 weeks of treatment compared with patients without (70.0% vs. 44.8%, P = 0.005). However, the two groups did not differ in culture conversion and in smear conversion at 4, 8, 12, 16, 20 and 24 weeks of anti-tuberculosis treatment.

CONCLUSION

Patients with a history of previous anti-tuberculosis treatment are more likely to have positive sputum AFB smear at 2 weeks of treatment. However, sputum culture conversion is not affected by previous treatment history.

Solubility and stability of melatonin in propylene glycol and 2-hydroxypropyl-beta-cyclodextrin vehicles

The physicochemical properties of melatonin (MT) in propylene glycol (PG) and 2-hydroxypropyl-beta-cyclodextrin (2-HPbetaCD) vehicles were characterized. MT was endothermally decomposed as determined by differential scanning calorimetry (DSC). Melting point and heat of fusion obtained were 116.9+/-0.24 degrees C and 7249+/-217 cal/mol, respectively. MT as received from a manufacture was very pure, at least 99.9%. The solubility of MT in PG solution increased slowly until reaching 40% PG and then steeply increased. Solubility of MT increased linearly as concentration of 2-HPbetaCD without PG increased (R(2)=0.993). MT solubility in the mixtures of PG and 2-HPbetaCD also increased linearly but was less than the sum of its solubility in 2-HPbetaCD and PG individually. The MT solubility was low in water, simulated gastric or intestinal fluid but the highest in the mixture of PG (40 v/v%) and 2-HPbetaCD (30 w/v%) although efficiency of MT solubilization in 2-HPbetaCD decreased as the concentration of PG increased. MT was degraded in a fashion of the first order kinetics (r(2)>0.90). MT was unstable in strong acidic solution (HCl-NaCl buffer, pH 1.4) but relatively stable in other pH values of 4 approximately 10 at 70 degrees C. In HCl-NaCl buffer, MT in 10% PG was more quickly degraded and then slowed down at a higher concentration. However, the degradation rate constant of MT in 2-HPbetaCD was not changed significantly when compared to the water. The current studies can be applied to the dosage formulations for the purpose of enhancing percutaneous absorption or bioavailability of MT.

Effect of sodium phytate, sodium pyrophosphate and sodium tripolyphosphate on physico-chemical characteristics of restructured beef

The effects of 0.5% sodium phytate (SPT), sodium pyrophosphate (SPP), and sodium tripolyphosphate (STPP), along with 1% NaCl, on physico-chemical properties of restructured raw and cooked beef were evaluated. In raw beef stored for 1 day at 4 ° C, the SPT, SPP, and STPP increased pH and salt-soluble protein level and decreased %MetMb and thiobarbituric acid reactive substances (TBARS), compared to the control with salt alone (p < 0.05). In cooked beef, SPT, SPP, and STPP increased bind strength, cook yield, moisture level, and pH, and decreased TBARS (p < 0.05). SPP and STPP increased orthophosphate in both raw and cooked beef (p < 0.05), compared to the SPT and control. SPT, SPP, and STPP decreased the Hunter color L and b values and increased a value in raw beef (p < 0.05) but had no effect on the Hunter color values in cooked beef. The binding value of SPP and STPP were similar over time, and the time to reach maximum binding strength was 10s longer than SPT and 25s longer than the control. These results indicate that SPT compares favorably with traditional phosphates for bind strength and cooked yield, but SPT was slightly more effective than other phosphates for reduction of TBARS 1 day after cooking.

Structures of Staphylococcus aureus peptide deformylase in complex with two classes of new inhibitors

Peptide deformylase (PDF) catalyzes the removal of the formyl group from the N-terminal methionine residue in newly synthesized polypeptides, which is an essential process in bacteria. Four new inhibitors of PDF that belong to two different classes, hydroxamate/pseudopeptide compounds [PMT387 (7a) and PMT497] and reverse-hydroxamate/nonpeptide compounds [PMT1039 (15e) and PMT1067], have been developed. These compounds inhibited the growth of several pathogens involved in respiratory-tract infections, such as Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae, and leading nosocomial pathogens such as Staphylococcus aureus and Klebsiella pneumoniae with a minimum inhibitory concentration (MIC) in the range 0.1-0.8 mg ml(-1). Interestingly, the reverse-hydroxamate/nonpeptide compounds showed a 250-fold higher antimicrobial activity towards S. aureus, although the four compounds showed similar K(i) values against S. aureus PDF enzymes, with K(i) values in the 11-85 nM range. To provide a structural basis for the discovery of additional PDF inhibitors, the crystal structures of S. aureus PDF in complex with the four inhibitors were determined at resolutions of 1.90-2.30 Å. The inhibitor-bound structures displayed distinct deviations depending on the inhibitor class. The distance between the Zn(2+) ion and the carbonyl O atom of the hydroxamate inhibitors (or the hydroxyl O atom of the reverse-hydroxamate inhibitors) appears to be correlated to S. aureus inhibition activity. The structural information reported in this study should aid in the discovery of new PDF inhibitors that can be used as novel antibacterial drugs.

Selenoprotein dSelK in Drosophila elevates release of Ca2+ from endoplasmic reticulum by upregulating expression of inositol 1,4,5-tris-phosphate receptor

dSelK (G-rich), a homolog of human and mouse SelK, is one of three selenoproteins in Drosophila melanogaster. It is the only trans-membrane selenoprotein in D. melanogaster integrated into both the endoplasmic reticulum (ER) membrane and the Golgi apparatus. The gene expression profile of Drosophila Schneider 2 (S2) cells after the dsRNA interference (dsRNAi) targeting of dSelK was examined with the GeneChip Drosophila Genome 2.0 Array (Affymetrix), a high-density oligonucleotide microarray encompassing nearly the full Drosophila genome. The results showed that the transcriptional expression of eight genes whose proteins are located on (or related to) the ER or the Golgi apparatus was highly induced or repressed by the dsRNAi treatment. The mRNA levels of the inositol 1,4,5-tris-phosphate receptor (IP3 receptor), whose gene product is integrated into the ER membrane and regulates the release of Ca2+ from the ER to the cytosol, were significantly downregulated. In contrast, the expression of inositol 1,4,5-tris-phosphate kinase 1, which is a cytosolic protein with opposing functions to the IP3 receptor, was significantly upregulated. Quantitative real-time PCR verified these results. The concentration of intracellular free Ca2+ of the Drosophila S2 cells was significantly decreased after the knockdown of dSelK, whereas overexpression of dSelK significantly increased the intracellular free Ca2+ concentration. These results indicate that dSelK in D. melanogaster is involved in regulating the release of Ca2+ from the ER to the cytosol and may play important roles in the signal transduction pathways involving Ca2+ mobilization.

Differences in the prevalence of colorectal polyps in patients undergoing endoscopic removal of gastric adenoma or early gastric cancer and in healthy individuals

BACKGROUND AND AIMS

We compared the prevalence of adenomatous and cancerous colon polyps in patients who underwent endoscopic removal of gastric neoplasms and in healthy controls.

MATERIALS AND METHODS

This retrospective study reviewed the medical records of 186 patients with gastric neoplasms and 186 healthy subjects from January 2002 to October 2008. The gastric neoplasm group was comprised of patients undergoing endoscopic removal of gastric adenomas or early gastric cancers and serial fiberoptic colonoscopy (FCS) for checkups. The control group was comprised of subjects undergoing fiberoptic esophagogastroduodenoscopy (FEGD) and FCS for general checkup and was matched for age and sex with the gastric neoplasm group. Advanced colonic neoplasm was defined by any of the following: (1) the presence of three or more polyps; (2) polyp size at least 1.0 cm; (3) high-grade dysplasia or adenocarcinoma confirmed by histopathologic examination.

RESULTS

Of the 372 persons, colorectal polyps were detected in 124 (33.3 %), advanced colonic neoplasms in 44 (11.8 %), and adenocarcinomas in 10 (2.7 %). The overall prevalence of adenomatous or cancerous polyps ("all polyps") and the prevalence of advanced colonic neoplasms were significantly higher in the gastric neoplasm group than in the control group (all polyps: 40.9 % in the gastric neoplasm group vs. 25.8 % in the control group, P = 0.002; advanced colonic neoplasms: 15.6 % vs. 8.1 %, P = 0.025). The risk factors for all polyps were age, male sex, diabetes mellitus, and being assigned to the gastric neoplasm group, and those for advanced colonic neoplasms were age and being assigned to the gastric neoplasm group. Confining the analysis to the gastric neoplasm group, the risk factors for all polyps were identical with those for the total group; however, those for advanced colonic neoplasm were different (age vs. diabetes and hypertriglyceridemia).

CONCLUSION

Endoscopists should consider performing routine FCS in patients undergoing endoscopic removal of gastric neoplasms.

Devastation of bone tissue in the appendicular skeleton parallels the progression of neuromuscular disease

A mouse model of spinal muscular atrophy with respiratory distress (SMARD1) was used to study the consequences of neuromuscular degenerative disease on bone quantity and morphology. Histomorphometry and micro-computed tomography were used to assess the cortical and cancellous bone in the tibia, femur and humerus of adult neuromuscular degeneration (nmd) mice (up to 21w) and age-matched wild-type controls (WT). At 21w, the average lengths of the humerus, tibia and femur were 15%, 10%, and 10% shorter in the nmd mice, respectively. The midshaft of the humerus, tibia and femur of nmd mice had 41%, 47% and 34% less cortical bone than the WT. In the humeral, tibial, and femoral metaphyses of the nmd mice, there was 50%, 78%, and 85% less trabecular bone volume, and 58%, 92%, and 94% less trabecular connectivity than the WT. NMD cortical bone had less than half of the 42% active surface measured in the WT, yet the mineral apposition rate of those surfaces were similar between strains (nmd: 1.80 microm x day(-1); WT: 2.05 microm x day(-1)). Osteoclast number and activity levels did not differ across strains. These data emphasize that neuromuscular degeneration as a result of immunoglobulin S-mu binding protein-2 (Ighmbp2) mutation will compromise several critical parameters of bone quantity and architecture, the most severe occurring in the trabecular compartment.

Visible and near-infrared radiative properties of vertically aligned multi-walled carbon nanotubes

This work investigates the reflection and scattering from vertically aligned carbon nanotubes, fabricated on silicon substrate using thermally enhanced chemical vapor deposition with both tip-growth and base-growth mechanisms. The directional-hemispherical reflectance in the visible and near-infrared wavelengths was measured with an integrating sphere. The polarization-dependent bidirectional reflectance distribution function was characterized with a laser scatterometer at the wavelength of 635 nm. The effective medium theory was used to elucidate the mechanism of high absorptance (greater than 0.97 in the spectral region from 400 to 1800 nm) of the multi-walled carbon nanotube samples. It is observed that scattering by impurities on the top of the nanotubes, by the nanotube tips, and by defects and misalignment can significantly increase the reflectance and introduce retroreflection. This study may facilitate application of carbon nanotubes in pyroelectric detectors as well as thermophotovoltaic emitters and absorbers.

Membrane binding properties of EBV gp110 C-terminal domain; evidences for structural transition in the membrane environment

Gp110 of Epstein-Barr virus (EBV) mainly localizes on nuclear/ER membranes and plays a role in the assembly of EBV nucleocapsid. The C-terminal tail domain (gp110 CTD) is essential for the function of gp110 and the nuclear/ER membranes localization of gp110 is ruled by its C-terminal unique nuclear localization signal (NLS), consecutive four arginines. In the present study, the structural properties of gp110 CTD in membrane mimics were investigated using CD, size-exclusion chromatography, and NMR, to elucidate the effect of membrane environment on the structural transition and to compare the structural feature of the protein in the solution state with that of the membrane-bound form. CD and NMR analysis showed that gp110 CTD in a buffer solution appears to adopt a stable folding intermediate which lacks compactness, and a highly helical structure is formed only in membrane environments. The helical content of gp110 CTD was significantly affected by the negative charge as well as the size of membrane mimics. Based on the elution profiles of the size-exclusion chromatography, we found that gp110 CTD intrinsically forms a trimer, revealing that a trimerization region may exist in the C-terminal domain of gp110 like the ectodomain of gp110. The mutation of NLS (RRRR) to RTTR does not affect the overall structure of gp110 CTD in membrane mimics, while the helical propensity in a buffer solution was slightly different between the wild-type and the mutant proteins. This result suggests that not only the helicity induced in membrane environment but also the local structure around NLS may be related to trafficking to the nuclear membrane. More detailed structural difference between the wild-type and the mutant in membrane environment was examined using synthetic two peptides including the wild-type NLS and the mutant NLS.

Coherent thermal emission by excitation of magnetic polaritons between periodic strips and a metallic film

The present paper theoretically demonstrates coherent thermal emission in the infrared region by exciting magnetic polaritons between metallic gratings and an opaque metallic film, separated by a dielectric spacer. The coupling of the metallic strips and the film induces a magnetic response that is characterized by a negative permeability and positive permittivity. On the other hand, the metallic film intrinsically exhibits a negative permittivity and positive permeability in the near infrared. This artificial structure is equivalent to a pair of single-negative materials. By exciting surface magnetic polaritons, large emissivity peaks can be achieved at the resonance frequencies and are almost independent of the emission angle. The resonance frequency of the magnetic response can be predicted by an analogy to an inductor and capacitor circuit. The proposed structure can be easily constructed using micro/nanofabrication.

Structural insight into the distinct properties of copper transport by the Helicobacter pylori CopP protein

Helicobacter pylori CopP (HpCopP) is a putative copper binding regulatory protein composed of 66 amino acid residues. The small HpCopP protein is homologous to CopZ, encoded by the E. hirae and B. subtilis cop operons. To clarify the role of HpCopP in copper metabolism in H. pylori, we studied the structural and copper binding characteristics by NMR spectroscopy. Based on the resonance assignments, the tertiary structure of HpCopP was determined. Unlike the betaalphabetabetaalphabeta fold of the homologous CopZ, HpCopP adopts the betaalphabetabetaalpha fold. The superposition with structures of other bacterial copper binding proteins showed that the global structure of HpCopP follows the general topology of the family, regardless of absence of the C-terminal beta-strand. The Cu(I) binding property of HpCopP was well conserved like CopZs: the structural changes due to Cu(I) and Ag(I) bindings were primarily restricted to the metal binding motif (CXXC motif). On the other hand, the Cu(II) binding property of CopP was different with that of CopZ: in the absence of reducing agent, Cu(II) ion oxidized a mutant HpCopP, resulting in disulfide bond formation in the CXXC motif. The Cu(II) ion binding property was evaluated using the mutant HpCopP, in which two amino acids were artificially introduced at the C-terminus, since the reduced state of the CXXC motif was more stabile in the mutant HpCopP without a reducing agent. Here, the structure and copper binding property of HpCopP are discussed in detail.

Hyperthermal neutral beam sources for material processing

Hyperthermal neutral beams have a great potential for material processes, especially for etching and thin film deposition for semiconductor and display fabrication as well as deposition for various thin film applications. Plasma-induced damage during plasma etching is a serious problem for manufacturing deep submicron semiconductor devices and is expected to be a problem for future nanoscale devices. Thermal and plasma-induced damage is also problematic for thin film depositions such as transparent conductive oxide films on organic light emitting diodes or flexible displays due to high temperature processes in plasma environments. These problems can be overcome by damage-free and low-temperature processes with hyperthermal neutral beams. We will present the status of the hyperthermal neutral beam development and the applications, especially, in semiconductor and display fabrication and introduce potential applications of thin film growing for optoelectronic devices such as light emitting diodes.

Surface waves between metallic films and truncated photonic crystals observed with reflectance spectroscopy

We have analyzed and demonstrated surface-wave excitations, by propagating waves in air, at the interface between a truncated photonic crystal (PC) and a silver film in the near-infrared. The truncated PC was fabricated with several unit cells of alternating SiO(2) and Si(3)N(4) layers. The dispersion relation of surface waves was calculated using the supercell method. A Fourier-transform infrared spectrometer measured the spectral reflectance of the fabricated sample at different incidence angles. An angle-resolved laser scatterometer measured the reflectance as a function of the incidence angle at the wavelength of 891 nm. The agreement between the resonance conditions obtained from experiments and the calculated dispersion relation manifests that surface waves at the PC-Ag interface may be utilized to build coherent thermal-emission sources.

Laryngeal exposure during laryngoscopy is better in the 25 degrees back-up position than in the supine position

BACKGROUND

Good visualization of the glottis is important for tracheal intubation. This study evaluated whether the 25 degrees back-up position improves the quality of the laryngeal view during laryngoscopy.

METHODS

Laryngoscopy with a curved blade was performed on 40 anaesthetized patients. The patients were randomly assigned to two groups. Laryngeal views were captured with a rigid 0 degrees endoscope. Views were recorded for each patient in Group A (n = 20) during laryngoscopies performed with the patient lying first in the supine position and then in the 25 degrees back-up position. Laryngeal views for patients in Group B (n = 20) were first captured while the patient was in the 25 degrees back-up position and then while the patient was in the flat supine position. An anaesthetist blinded to the position graded the quality of the images using the percentage of glottic opening (POGO) score.

RESULTS

Comparing the two positions, mean (sd) POGO scores increased significantly from 42.2 (27.4)% in supine position to 66.8 (27.6)% in 25 degrees back-up position (P < 0.0001).

CONCLUSIONS

During laryngoscopy, the laryngeal view, as assessed by POGO scores, improves significantly in the 25 degrees back-up position when compared with the flat supine position.

A novel strategy for identifying mutations that sensitize Drosophila eye development to caffeine and hydroxyurea

This report describes a novel strategy for isolating Drosophila mutants with conditional eye phenotypes that should be generally applicable for identifying genes required for cellular responses to specific drugs. To test the strategy, we screened 3 of the 5 major chromosome arms for hydroxyurea- and (or) caffeine-sensitive (huc) mutants, and isolated mutations affecting 5 different complementation groups. Most of these were represented by single alleles; however, we also isolated multiple alleles of huc(29DE) gene, an essential gene that is also associated with a nonconditional pupal lethal phenotype. We also identified huc(95E) mutants, which are extremely sensitive to caffeine. Although huc(95E) is a nonessential gene, mutant imaginal disc cells undergo caffeine-dependent apoptosis, and huc(95E) gene function is required for the viability of the organism when mutant larvae are exposed to levels of caffeine that controls can easily tolerate. We have mapped the cytological positions of huc(29D) and huc(95E) as a first step toward molecularly characterizing the relevant genes.

Identification of the WW domain-interaction sites in the unstructured N-terminal domain of EBV LMP 2A

Epstein-Barr virus latency is maintained by the latent membrane protein (LMP) 2A, which mimics the B-cell receptor (BCR) and perturbs BCR signaling. The cytoplasmic N-terminal domain of LMP2A is composed of 119 amino acids. The N-terminal domain of LMP2A (LMP2A NTD) contains two PY motifs (PPPPY) that interact with the WW domains of Nedd4 family ubiquitin-protein ligases. Based on our analysis of NMR data, we found that the LMP2A NTD adopts an overall random-coil structure in its native state. However, the region between residues 60 and 90 was relatively ordered, and seemed to form the hydrophobic core of the LMP2A NTD. This region resides between two PY motifs and is important for WW domain binding. Mapping of the residues involved in the interaction between the LMP2A NTD and WW domains was achieved by chemical shift perturbation, by the addition of WW2 and WW3 peptides. Interestingly, the binding of the WW domains mainly occurred in the hydrophobic core of the LMP2A NTD. In addition, we detected a difference in the binding modes of the two PY motifs against the two WW peptides. The binding of the WW3 peptide caused the resonances of five residues (Tyr(60), Glu(61), Asp(62), Trp(65), and Gly(66)) just behind the N-terminal PY motif of the LMP2A NTD to disappear. A similar result was obtained with WW2 binding. However, near the C-terminal PY motif, the chemical shift perturbation caused by WW2 binding was different from that due to WW3 binding, indicating that the residues near the PY motifs are involved in selective binding of WW domains. The present work represents the first structural study of the LMP2A NTD and provides fundamental structural information about its interaction with ubiquitin-protein ligase.

Sexual behaviour induces the expression of activity-regulated cytoskeletal protein and modifies neuronal morphology in the female rat ventromedial hypothalamus

Female sexual behaviour activates a distributed network within the brain, including the ventrolateral subdivision of the hypothalamic ventromedial nucleus (vlVMH), as demonstrated by behavioural studies performed in conjunction with the neuroanatomical analysis of immediate early gene (IEG) expression. However, it has been difficult to interpret mating-induced IEG expression because the precise function of many IEGs remains poorly defined. One possible function for genomic activation of the vlVMH during mating behaviour is to establish synaptic remodelling. The present experiments tested the hypothesis that sexual behaviour rapidly induces the expression of a structural protein associated with synaptic plasticity and ultimately causes morphological changes in the vlVMH. First, the expression of activity-regulated cytoskeletal protein (Arc), an IEG associated with neural plasticity, was assayed immunohistochemically in females after approximately 1 h of mating. The number of Arc-labelled neurones in the vlVMH was greater in mated females compared to unmated controls. Second, VMH neurones were biolistically labelled for morphological measurements, including soma size, dendrite number and length and dendritic spine density. Dendritic spine density in the vlVMH was significantly reduced 5 days after mating in experienced females compared to sexually naïve females. There were no differences between these groups in soma size, dendrite length or dendrite number. Collectively, these studies suggest that mating behaviour produces short-term changes in structural proteins and long-term, selective changes in dendrite morphology, which then may influence future behaviours and/or physiology.

Tongue abscess mimicking neoplasia

Tongue abscess is a very rare condition about which only sparse imaging findings have been reported. In 2 patients, a submucosal malignant tumor was suspected because of the presence of a painful hard tongue mass with intact mucosal surface. Differential diagnosis of the tongue abscess or malignancy was difficult on MR imaging or positron emission tomography-CT. In careful retrospective history taking, the symptoms had dated from an episode of eating fish several months before presentation. Plain radiographs and noncontrast CT images of the pharynx revealed a foreign body within the lesion. Thus, we present the imaging findings of 2 cases of malignancy mimicking tongue abscess as a result of impaction of a fish bone.

Lateral shift in photon tunneling studied by the energy streamline method

The energy streamline method based on the Poynting vector of the coupled forward and backward waves is used to study photon tunneling phenomenon associated with the lateral shift of energy path. Each point on the energy streamline indicates the direction of the net energy flow of a plane wave. In the tunneling configuration, the light energy of the propagating waves is squeezed to the inside of a cone, whereas the streamlines of the coupled evanescent waves go through the barrier inside or outside the cone. This observation provides insight of the photon tunneling phenomenon. A relationship between the energy refraction angle and the incidence angle exists in the proximity limit and can be used to evaluate the lateral shift of the energy path. Furthermore, the energy streamline method can help gain deeper understanding of nanoscale radiation where photon tunneling plays an important role in the heat transfer enhancement.

Measurement and modelling of ordinary heterotrophic organism active biomass concentrations in anoxic/aerobic activated sludge mixed liquor

Ordinary heterotrophic organism (OHO) active biomass (ZBH) is a key parameter in models for activated sludge systems, which defines quantitatively the kinetic rates of relevant processes. However, ZBH has not been measured directly with consistent success: a simple respirometric batch test has provided varying correspondence between measured and theoretical concentrations. In this paper, the batch test is applied to mixed liquors drawn from well defined anoxic/aerobic parent systems at 10 and 20 d sludge ages, with consistent but poor correspondence between measured and theoretical values. In contrast, aerobic digestion batch tests on the same mixed liquors give good correspondences. It is concluded that the differences between theoretical and batch test measured values are due to the batch test method itself and its interpretation. It is found that the batch test conditions (particularly the substrate/ZBH ratio) influence the kinetic constants derived from the data, and hence the ZBH estimate. Two kinetic models with two competing OHO populations, a fast and a slow grower, are developed and applied to the batch tests and parent systems. The first model is based on kinetic selection only, while the second includes additional metabolic selection. Both models can account for the observations in the batch tests, but the second provides greater consistency between simulations of the parent systems and batch tests.

Expression and characterization of N-terminal domain of Epstein-Barr virus latent membrane protein 2A in Escherichia coli

Latency of Epstein-Barr virus (EBV) is maintained by the transmembrane protein latent membrane protein (LMP) 2A, which mimics the B-cell receptor (BCR) and perturbs BCR signaling. LMP2A contains a cytoplasmic N-terminal domain composed of 119 amino acids, which provides signals that are responsible for the association with various signal molecules, resulting in negative regulation of B-cell signaling and the EBV lytic cycle. In the present study, to obtain N-terminal domain of LMP2A (LMP2A NTD, 13 kDa) in Escherichia coli for structural analysis, a strategy for obtaining the unfused form of LMP2A NTD without any fusion partners was proposed. Recombinant LMP2A NTD has previously been expressed using the GST fusion system in E. coli [Virology 268 (2000) 178, J. Virol. 71 (1997) 4752, Mol. Cell. Biol. 20 (2000) 8526]. However, we were unable to obtain untagged LMP2A NTD from this construct because of rapid proteolysis by thrombin. To overcome the proteolysis by thrombin, C-terminal His-tagged LMP2A NTD and intein-fused LMP2A NTD were prepared. As a result, LMP2A NTD without a fusion partner could be successfully obtained using non-enzymatic cleavage. The secondary structure of the recombinant LMP2A NTD was analyzed using circular dichroism. In aqueous solution, LMP2A NTD adopts an unordered structure, which was not affected by varying pH and salt concentration. In addition, any secondary structural components of LMP2A NTD were not induced in the membrane-mimicking environments, suggesting that LMP2A NTD may intrinsically have a random coil-like structure. The biological activity of recombinant LMP2A NTD was monitored by chemical shift perturbation in HSQC spectra of LMP2A NTD with or without WW domains, which result supports that the structural change induced by WW domains is restricted within narrow region.