Hard X-ray microbeam lithography using a Fresnel zone plate with a long focal length

Focused hard X-ray microbeams for use in X-ray nanolithography have been investigated. A 7.5 keV X-ray beam generated at an undulator was focused to about 3 µm using a Fresnel zone plate fabricated on silicon. The focused X-ray beam retains a high degree of collimation owing to the long focal length of the zone plate, which greatly facilitates hard X-ray nanoscale lithography. The focused X-ray microbeam was successfully utilized to fabricate patterns with features as small as 100 nm on a photoresist.

Characteristics of color optical shutter with dye-doped polymer network liquid crystal

The optical properties and the theoretical prediction of color optical shutter with dye-doped polymer network liquid crystal (PNLC) were investigated. The view-angle dependence of reflectance according to the bias conditions showed distinctive characteristics, which could be explained from the effects of dye absorption and path length. It was also shown that the thickness dependence of reflectance was strongly influenced by the light-scattering coefficient. Our experimental results matched up well with the theoretical prediction based on the light scattering of liquid crystals in polymer network and the absorption of dichroic dye. This work indicates potential to improve the optical device using dye-doped liquid crystal-polymer composite.

Regional volume analysis of the Parkinson disease brain in early disease stage: gray matter, white matter, striatum, and thalamus

BACKGROUND AND PURPOSE

Loss of dopaminergic neurons in the nigrostriatal pathway is well-documented in PD, whereas neuronal changes beyond the nigrostriatal pathway are uncertain. The purpose of our study was to estimate volume changes in the striatum and thalamus, which are areas of the basal ganglia, as well as in GM and WM located beyond the nigrostriatal pathway, in early-stage PD.

MATERIALS AND METHODS

We enrolled 30 participants (15 healthy controls and 15 patients with PDND with H & Y stage I or II). Cognitive function was assessed by using the MMSE. ICV and the volumes of the caudate nucleus, putamen, thalamus, GM, and WM were calculated via 3D volume analysis by using MR imaging.

RESULTS

A comparison of the PD group with the control group revealed an absence of significant differences between them regarding age and MMSE scores. Comparison of the volumes of regional brain structures of patients with PD with those of controls revealed the presence of significant differences in the caudate nucleus, thalamus, and WM (P<.05) between the groups. However, there were no significant differences in the volumes of the putamen and GM or in ICV between patients with PD and controls. The results of ANCOVA by using the covariates of age and ICV showed a significant difference in the caudate nucleus, thalamus, and WM between patients with PD and controls (P<.05).

CONCLUSIONS

We suggest that loss of WM volume may occur in early disease stages and that variation of the volumes of the caudate nucleus and thalamus may be an early phenomenon of disease progression.

Imbalanced K+ and Ca2+ subthreshold interactions contribute to increased hypothalamic presympathetic neuronal excitability in hypertensive rats

Despite the importance of brain-mediated sympathetic activation in the morbidity and mortality of patients with high blood pressure, the precise cellular mechanisms involved remain largely unknown. We show that an imbalanced interaction between two opposing currents mediated by potassium (I(A)) and calcium (I(T)) channels occurs in sympathetic-related hypothalamic neurons in hypertensive rats. We show that this imbalance contributes to enhanced membrane excitability and firing activity in this neuronal population. Knowledge of how these opposing ion channels interact in normal and disease states increases our understanding of underlying brain mechanisms contributing to the high blood pressure condition.

Cancer survival in Busan, Republic of Korea, 1996-2001

The Busan cancer registry was established in 1996; cancer registration is done by passive and active methods. The registry contributed survival data for 48 cancer sites or types registered during 1996-2001. Follow-up information has been gleaned predominantly by passive methods with median follow-up ranging between 1-57 months for various cancers. The proportion with histologically verified diagnosis for different cancers ranged between 20-100%; death certificates only (DCOs) comprised 0-53%; 47-100% of total registered cases were included for survival analysis. The top-ranking cancers on 5-year age-standardized relative survival rates were penis (94%), thyroid (91%), non-melanoma skin (89%), placenta (86%), breast (76%), Hodgkin lymphoma (75%) and testis (72%). Five-year relative survival by age group showed a decreasing trend with increasing age groups for cancers of the nasopharynx, gall bladder, lung, bone, soft tissue, breast, cervix, corpus uteri, thyroid, multiple myeloma, lymphoid leukaemia and myeloid leukaemia or was fluctuating for other cancers.

Nano-electromechanical switch-CMOS hybrid technology and its applications

Si-based CMOS technology is facing a serious challenge in terms of power consumption and variability. The increasing costs associated with physical scaling have motivated a search for alternative approaches. Hybridization of nano-electromechanical (NEM)-switch and Si-based CMOS devices has shown a theoretical feasibility for power management, but a huge technical gap must be bridged before a nanoscale NEM switch can be realized due to insufficient material development and the limited understanding of its reliability characteristics. These authors propose the use of a multilayer graphene as a nanoscale cantilever material for a nanoscale NEM switchwith dimensions comparable to those of the state-of-the-art Si-based CMOS devices. The optimal thickness for the multilayer graphene (about five layers) is suggested based on an analytical model. Multilayer graphene can provide the highest Young's modulus among the known electrode materials and a yielding strength that allows more than 15% bending. Further research on material screening and device integration is needed, however, to realize the promises of the hybridization of NEM-switch and Si-based CMOS devices.

Application of ZnO single-crystal wire grown by the thermal evaporation method as a chemical gas sensor for hydrogen sulfide

A zinc oxide single-crystal wire was synthesized for application as a gas-sensing material for hydrogen sulfide, and its gas-sensing properties were investigated in this study. The gas sensor consisted of a ZnO thin film as the buffer layer and a ZnO single-crystal wire. The ZnO thin film was deposited over a patterning silicon substrate with a gold electrode by the CFR method. The ZnO single-crystal wire was synthesized over the ZnO thin film using zinc and activated carbon as the precursor for the thermal evaporation method at 800 degrees C. The electrical properties of the gas sensors that were prepared for the growth of ZnO single-crystal wire varied with the amount of zinc contained in the precursor. The charged current on the gas sensors increased with the increasing amount of zinc in the precursor. It was concluded that the charged current on the gas sensors was related to ZnO single-crystal wire growth on the silicon substrate area between the two electrodes. The charged current on the gas sensor was enhanced when the ZnO single-crystal wire was exposed to a H2S stream. The experimental results obtained in this study confirmed that a ZnO single-crystal wire can be used as a gas sensor for H2S.

A novel method for air drying aloe leaf slices by covering with filter papers as a shrink-proof layer

To prevent the shrinkage of aloe vera slices during air drying, a method utilizing a shrink-proof layer was developed. The sample was configured of whole leaf aloe slices, where 1 side or both sides were covered with filter papers as shrink-proof layers. After air drying by varying the air temperature and the slice thickness, the drying characteristics, as well as several quality factors of the dried aloe vera leaf slices, were analyzed. In the simulation of the drying curves, the modified Page model showed the best fitness, representing a diffusion-controlled drying mechanism. Nonetheless, there was a trace of a constant-rate drying period in the samples dried by the method. Shrinkage was greatly reduced, and the rehydration ratios increased by approximately 50%. Scanning electron microscopic analysis revealed that the surface structure of original fibrous form was well sustained. FT-IR characteristics showed that the dried samples could sustain aloe polysaccharide acetylation. Furthermore, the functional properties of the dried slices including water holding capacity, swelling, and fat absorption capability were improved, and polysaccharide retention levels increased by 20% to 30%. Therefore, we concluded that application of shrink-proof layers on aloe slices provides a novel way to overcome the shrinkage problems commonly found in air drying, thereby improving their functional properties with less cost. Practical Application: This research article demonstrates a novel air drying method using shrink-proof layers to prevent the shrinkage of aloe slices. We analyzed extensively the characteristics of shrinkage mechanism and physical properties of aloe flesh gels in this drying system. We concluded that this method can be a beneficial means to retain the functional properties of dried aloe, and a potential alternative to freeze drying, which is still costly.

Poly(3-Hydroxybutyrate) Production with High Productivity and High Polymer Content by a Fed-Batch Culture of Alcaligenes latus under Nitrogen Limitation

Alcaligenes latus has been known to produce poly(3-hydroxybutyrate) (PHB) in a growth-associated manner even under nutrient-sufficient conditions. However, the PHB content obtained by fed-batch culture was always low, at ca. 50%, which makes the recovery process inefficient. In this study, the effect of applying nitrogen limitation on the production of PHB by A. latus was examined. In flask and batch cultures, the PHB synthesis rate could be increased considerably by applying nitrogen limitation. The PHB content could be increased to 87% by applying nitrogen limitation in batch culture, which was considerably higher than that typically obtainable (50%) under nitrogen-sufficient conditions. In fed-batch culture, cells were first cultured by the DO-stat feeding strategy without applying nitrogen limitation. Nitrogen limitation was applied at a cell concentration of 76 g (dry cell weight)/liter, and the sucrose concentration was maintained within 5 to 20 g/liter. After 8 h of nitrogen limitation, the cell concentration, PHB concentration, and PHB content reached 111.7 g (dry cell weight)/liter, 98.7 g/liter, and 88%, respectively, resulting in a productivity of 4.94 g of PHB/liter/h. The highest PHB productivity, 5.13 g/liter/h, was obtained after 16 h.

Immune regulatory effects of simvastatin on regulatory T cell-mediated tumour immune tolerance

Statins are potent inhibitors of hydroxyl-3-methylglutaryl co-enzyme A (HMG-CoA) reductase, and have emerged as potential anti-cancer agents based on preclinical evidence. In particular, compelling evidence suggests that statins have a wide range of immunomodulatory properties. However, little is known about the role of statins in tumour immune tolerance. Tumour immune tolerance involves the production of immunosuppressive molecules, such as interleukin (IL)-10, transforming growth factor (TGF)-beta and indoleamine-2,3-dioxygenase (IDO) by tumours, which induce a regulatory T cell (T(reg)) response. In this study, we investigated the effect of simvastatin on the production of IL-10, TGF-beta and IDO production and the proliferation of T(regs) using several cancer cell lines, and Lewis lung cancer (3LL) cells-inoculated mouse tumour model. Simvastatin treatment resulted in a decrease in the number of cancer cells (3LL, A549 and NCI-H292). The production of the immune regulatory markers IL-10, TGF-beta in 3LL and NCI-H292 cells increased after treatment with simvastatin. The expression of IDO and forkhead box P3 (FoxP3) transcription factor was also increased in the presence of simvastatin. In a murine 3LL model, there were no significant differences in tumour growth rate between untreated and simvastatin-treated mice groups. Therefore, while simvastatin had an anti-proliferative effect, it also exhibited immune tolerance-promoting properties during tumour development. Thus, due to these opposing actions, simvastatin had no net effect on tumour growth.

Assessment of Achilles enthesitis in the spondyloarthropathies by colour Doppler energy ultrasound in the context of the 'enthesis organ'

OBJECTIVES

To identify the characteristic features of Achilles enthesitis of the spondyloarthropathies (SpA) detectable by colour Doppler energy ultrasound (CDEU) in the context of the 'enthesis organ'.

METHODS

Seventy patients with SpA and 15 healthy subjects were clinically evaluated and underwent CDEU examination of the Achilles entheses. The CDEU images were evaluated according to five distinctive CDEU features of enthesitis in the context of the enthesis organ.

RESULTS

Fifty-six of the 70 SpA patients (80%) showed at least one abnormal finding of the enthesitis on CDEU examination, affecting 91 of 140 Achilles entheses examined (65%). Only 22 of 140 Achilles entheses (15.7%) showed abnormal vascularization in the peri-sesamoidal and periosteal areas or in the area of enthesis fibrocartilage. In addition, 67 (47.9%) and 18 (12.9%) of 140 Achilles entheses examined showed cortical bone irregularities and erosions, respectively, at areas of the periosteal and the enthesis fibrocartilage. Sixteen (88.9%) of 18 clinically detected Achilles enthesitis and six (75%) of eight Achilles entheses with swelling on clinical examination presented corresponding abnormalities on CDEU examination. The Doppler twinkling artefact (TA) was observed consistently in all normal entheses and completely disappeared upon stabilization of the probe application. The C-reactive protein (CRP) level was higher in the patients with cortical bone erosion than in those without erosion.

CONCLUSIONS

This study demonstrates the characteristic features of enthesitis detectable by CDEU in the context of the enthesis organ and shows a good correlation with clinical as well as with laboratory findings.

Pregnancy outcome of women transfused during pregnancy with blood products inadvertently obtained from donors treated with acitretin

We assessed the pregnancy outcome of nine women inadvertently transfused with acitretin-contaminated blood products in South Korea. A total of 18 women matched to cases by age, gravidity, and singleton- or twin-pregnancy, and who were transfused with blood products not contaminated with acitretin, was also recruited. There were nine babies born in the case group. No differences (p > 0.05) were observed between cases and controls in the gestational age at delivery (38.3 +/- 1.6 weeks vs 37.8 +/- 2.2 weeks), birth weight (3,146 +/- 874 g vs 3,106 +/- 568 g), rate of pre-term deliveries (22.2% vs 11.1%) and rate of low birth weight (<2,500 g) (33.3% vs 16.7%). There was no case of malformation or neurological abnormalities born in either group. In conclusion, inadvertent exposure to acitretin-contaminated blood products was not associated with adverse pregnancy outcomes, probably because of the removal of acitretin and etretinate during the manufacturing process of blood products.

Synergy of TLR2 and H1R on Cox-2 Activation in Pulpal Cells

Although pulp fibroblasts are a major cell type in dental pulp, their roles in microbial recognition and pulpal inflammation are not well-understood. Considering the pivotal role of Toll-like receptors (TLRs) in the recognition of micro-organisms, we hypothesized that TLRs on pulp fibroblasts may induce inflammatory signals in dental pulp. In human pulp fibroblasts, TLR2, 3, 4, and 5 were constitutively expressed. Stimulation of TLR2 and 3 induced the expression of pro-inflammatory genes such as CXCL10, CCL5, and/or Cox-2 in pulp fibroblasts. Interestingly, histamine synergistically activated TLR2-mediated Cox-2 expression and PGE(2) production. The synergistic effect of histamine is mediated by histamine receptor-1 (H1R). Studies on the intra-cellular signaling pathways revealed that p38 activation is required for the synergistic activation of Cox-2 by TLR2 and histamine. Analysis of these data suggests that TLR2 on pulp fibroblasts, in concert with H1R, can induce an inflammatory response during microbial infection in dental pulp.

Terahertz response in single-walled carbon nanotube transistor: a real-time quantum dynamics simulation

We use time-dependent quantum wavepacket methods to simulate ballistic electron transport in a single-walled carbon nanotube field-effect transistor at terahertz frequencies ( approximately 100 GHz-10 THz). We observe an electron resonance phenomenon in a sub-picosecond-scale time domain. Our simulation results clearly show that the electron resonance corresponds to the formation of the resonance cavity and the interference of the electron wavepackets, which is directly supported by recent experimental measurements (Zhong et al 2008 Nat. Nanotechnol. 3 201).

Synthesis of poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) by recombinant Escherichia coli

Several recombinant Escherichia coli strains, including XL1-Blue, JM109, HB101, and DH5alpha harboring a stable high-copynumber plasmid pSYL105 containing the Alcaligenes eutrophus polyhydroxyalkanoate (PHA) biosynthesis genes were constructed. These recombinant strains were examined for their ability to synthesize and accumulate poly-(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] copolymer from glucose and either propionate or valerate. All recombinant E. coli strains could synthesize the P(3HB-co-3HV) copolymer in the medium containing glucose and propionate. However, only the homopolymer poly-(3-hydroxybutyrate) [P(3HB)] was synthesized from glucose and valerate. The PHA concentration and the 3HV fraction could be increased by inducing with acetate and/or oleate. When supplemented with oleate, the 3HV fraction increased by fourfold compared with that obtained without induction. Induction with propionate resulted in lower PHA concentration due to the inhibitory effect, but an 3HV fraction of as high as 33.0% could be obtained. These results suggest that P(3HB-co-3HV) can be efficiently produced from propionate by recombinant E. coli by inducing with acetate, propionate, or oleate.

Bacterial polyhydroxyalkanoates

Polyhydroxyalkanoates (PHAs) are polyesters of hydroxyalkanoates (HAs) synthesized by numerous bacteria as intracellular carbon and energy storage compounds and accumulated as granules in the cytoplasm of cells. More than 80 HAs have been detected as constituents of PHAs, which allows these thermoplastic materials to have various mechanical properties resembling hard crystalline polymer or elastic rubber depending on the incorporated monomer units. Even though PHAs have been recognized as good candidates for biodegradable plastics, their high price compared with conventional plastics has limited their use in a wide range of applications. A number of bacteria including Alcaligenes eutrophus, Alcaligenes latus, Azotobacter vinelandii, methylotrophs, pseudomonads, and recombinant Escherichia coli have been employed for the production of PHAs, and the productivity of greater than 2 g PHA/L/h has been achieved. Recent advances in understanding metabolism, molecular biology, and genetics of the PHA-synthesizing bacteria and cloning of more than 20 different PHA biosynthesis genes allowed construction of various recombinant strains that were able to synthesize polyesters having different monomer units and/or to accumulate much more polymers. Also, genetically engineered plants harboring the bacterial PHA biosynthesis genes are being developed for the economical production of PHAs. Improvements in fermentation/separation technology and the development of bacterial strains or plants that more efficiently synthesize PHAs will bring the costs down to make PHAs competitive with the conventional plastics.

Comparison of recombinant Escherichia coli strains for synthesis and accumulation of poly-(3-hydroxybutyric acid) and morphological changes

A stable high-copy-number plasmid pSYL105 containing the Alcaligenes eutrophus polyhydroxyalkanoic acid (PHA) biosynthesis genes was constructed. This plasmid was transferred to seven Escherichia coli strains (K12, B, W, XL1-Blue, JM109, DH5alpha, and HB101), which were subsequently compared for their ability to synthesize and accumulate ploy- (3-hydroxybutyric acid) (PHB). Growth of recombinant cells and PHB synthesis were investigated in detail in Luria-Bertani (LB) medium containing 20 g/L glucose. Cell growth, the rate of PHB synthesis, the extent of PHB accumulation, the amount of glucose utilized, and the amount of acetate formed varied from one strain to another. XL1-Blue (pSYL105) and B (pSYL105) synthesized PHB at the fastest rate, which was ca. 0.2 g PHB/g true cell mass-h, and produced PHB up to 6-7 g/L. The yields of cell mass, true cell mass, and PHB varied considerably among the strains. The PHB yield of XL1-Blue (pSYL105) in LB plus 20 g/L glucose was as high as 0.369 g PHB/g glucose. Strains W (pSYL105) and K12 (pSYL105) accumulated the least amount of PHB with the lowest PHB yield at the lowest synthesis rate. JM109 (pSYL105) accumulated PHB to the highest extent (85.6%) with relatively low true cell mass (0.77 g/L). Considerable filamentation of cells accumulating PHB was observed for all strains except for K12 and W, which seemed to be due either to the overexpression of the foreign PHA biosynthesis enzymes or to the accumulation of PHB.

Elderly Mexicans have less muscle and greater total and truncal fat compared to African-Americans and Caucasians with the same BMI

BACKGROUND

How body composition, specifically skeletal muscle mass, compares in Mexican elderly to other ethnic groups has not previously been reported. We tested the hypothesis that older adults from Northwest Mexico (Mex) would have similar total appendicular skeletal muscle (TASM) compared with New York dwelling Caucasians (Cauc) and African-Americans (AA).

METHODS

Two hundred and eighty nine Mex (135 males and 154 females), 166 AA (36 males and 130 females) and 229 Cauc (64 males and 165 females), aged 60-98 years were assessed. Total and regional fat and lean tissues were measured by whole-body dual energy X-ray absorptiometry where TASM is the sum of arm and leg bone-free and fat-free lean tissue. Differences in TASM were tested by ANCOVA, with age, height, and body mass index (BMI) as covariates.

RESULTS

TASM adjusted for ethnicity, age, height and BMI, were 22.6 +/- 0.2 kg and 17.8 +/- 0.1 kg for males and females, respectively (p < 0.001). Among males with similar age, height, and BMI, Mex had less TASM compared with AA and Cauc (p < 0.001). Total body fat and truncal fat were higher (p < 0.001) and FFM lower (p < 0.001) in Mex compared to both AA and Cauc males after adjusting for age and BMI. Among females, Mex had higher total and truncal fat (p < 0.001) after adjusting for age and BMI, and significantly lower TASM (p < 0.001) after adjusting for age, height, and BMI compared to AA and Cauc females.

CONCLUSIONS

Elderly Mex have a different body composition compared with AA and Cauc of a similar BMI and age. Mex have significantly less TASM with greater total and truncal fat. In the long-term, Mex elderly may be at greater risk for sarcopenic obesity compared to other ethnic groups.

An efficient sound speed estimation method to enhance image resolution in ultrasound imaging

Most of clinical ultrasound imaging systems use a pre-determined sound speed, mostly 1540 m/s, in transmit- and receive-beamforming while actual sound speed varies depending on tissue composition and temperature. Sound speed errors, particularly in receive-beamforming, lead to resolution degradation and sensitivity loss in ultrasound imaging. In this paper, we propose a sound speed estimation method in which an optimal sound speed, the speed that makes the echo signal delays at the transducer elements be best matched to the theoretical delays, is estimated by maximizing the beamformed echo signal amplitude with respect to the sound speed and the reflector displacement from the central axis of the ultrasound beam. Since the sound speed can be estimated from the echo signals on several scan lines, the proposed method does not require excessive computation. Experimental imaging studies of phantoms and porcine tissue with a 6 MHz 128-element linear probe and a 3 MHz 128-element convex probe have shown that spatial resolution, particularly in the lateral direction, can be improved by the proposed method.

Non-O1, non-O139 Vibrio cholerae bacteraemia in splenectomised thalassaemic patient from Malaysia

Vibrio cholerae infection is mainly caused acute diarrhoea disease. Bacteraemia due to non-O1 V. cholerae is rare and mainly reported in liver cirrhotic patients. We report one case of non-O1 V. cholerae bacteraemia in splenectomised thalassaemic patient who presented with septic shock secondary to abdominal sepsis. She had undergone emergency laporatomy and was managed in the intensive care unit for nine days. She was treated with meropenem and doxycyline and discharged well after fourteen days of admission. The V. cholerae was identified by API 20NE, serotype and polymerase chain reaction showed as non-O1, non-O139 strain. Besides known cholera-like toxin and El Tor hemolysin, with increasing reported cases of V. cholerae bacteraemia, there is possibility of other virulence factors that allow this organism to invade the bloodstream.

Effect of active smoking on asthma symptoms, pulmonary function, and BHR in adolescents

BACKGROUND

Active smoking is known to increase asthma symptoms and bronchial hyper-responsiveness (BHR) while decreasing pulmonary function in adults, but few studies have addressed these issues in adolescents.

METHODS

We conducted a cross-sectional survey involving questionnaires and assessment of urinary cotinine levels among 1,492 adolescents from three urban areas of South Korea. Current smoking was defined as having smoked more than 1 day in the prior 30 days or having urine cotinine levels >or=100 ng/ml. Spirometry, skin tests, and methacholine challenge tests were performed on adolescents in Seoul (n = 724).

RESULTS

The prevalence of current smoking was 8.2% in boys and 2.4% in girls. Reports of wheeze and exercise-induced wheeze in the previous 12 months were more frequent in smokers than nonsmokers (15.2% vs. 8.5%, P = 0.024, and 20.4% vs. 10.7%, P = 0.004, respectively). In multiple logistic regression analysis, current smoking was found to be a significant risk factor for having wheezed in previous 12 months (OR = 4.5, 95% CI 1.5-13.2) and having exercise-induced wheezing in previous 12 months (OR = 8.7, 95% CI, 3.7-20.9). The subgroup analysis revealed that the FEV(1)/FVC was lower in smokers than nonsmokers (mean +/- SD, 105.1 +/- 8.6% vs. 107.8 +/- 7.8%, P = 0.019). In contrast, there was no significant difference in BHR. The effect of smoking on asthma symptoms were more pronounced in non-atopic compared with atopic adolescents.

CONCLUSION

Current smoking was significantly associated with symptoms of asthma, such as having recent wheezing and recent exercise-induced wheezing, especially for non-atopics, in Korean adolescent population. Current smoking was further associated with lower pulmonary function, but not BHR.

Where has the tumor gone? The characteristics of cases of negative pathologic diagnosis after endoscopic mucosal resection

BACKGROUND AND STUDY AIMS

Discrepancies can occur between the histopathological findings from forceps biopsy and endoscopic mucosal resection (EMR), and occasionally in embarrassing cases tumorous tissue is not found at EMR. The aim of the present study was to evaluate the clinical, endoscopic, and histological features of gastric tumors in patients with pathololgically negative findings at EMR.

PATIENTS AND METHODS

We retrospectively reviewed data from all patients with gastric tumor treated with EMR or endoscopic submucosal dissection (ESD) between August 1999 and April 2007 at our institution, and enrolled into the study patients with no tumor tissue found at mucosal resection. Their biopsy and EMR specimen slides were reviewed by a single pathologist. Patient characteristics, including demographic and clinical features, and the endoscopic appearance of mucosal lesions were evaluated.

RESULTS

Out of 633 patients treated with EMR or ESD, 20 patients (3.2 %) were included. The mean +/- SD maximal dimension of the mucosal lesions was 6.40 +/- 2.19 mm (range 3 - 10). Mean number of forceps biopsy fragments was 3.80 +/- 1.96 and mean sampling ratio was 2.08 +/- 1.07 mm/fragment. Before resection, histological findings from forceps biopsy were: 13 low grade dysplasias (65.0 %), 2 high grade dysplasias (10.0 %), and 5 intramucosal carcinomas (25.0 %).

CONCLUSIONS

In the case of pathologically negative findings at EMR, tumors might have been small enough to have been removed by the previous forceps biopsy. However, the possibility of sampling error or of a different location should be considered. Furthermore, appropriate communication between endoscopists and pathologists is essential.

Reductions in the effects of damping on stress concentration in premolars by post-endodontic restorations: a non-linear finite element study

The aim of this study was to measure the structural damping constants of premolars after treatment with a cast Co-Cr post-core system or permanent root filling, and to evaluate the stress damping effects of these restored premolars. Both the damping ratio and the natural frequency (NF) of the cast Co-Cr post-core restored premolars and the permanent root-filled premolars were detected by in-vitro NF testing experiments. Unprepared premolars served as the control. The damping constants beta of the samples were calculated from the measured damping ratios and natural frequencies. The measured damping constants beta of the test premolars were then used for dynamic finite element (FE) analyses. Stress contours and damping effects of stresses in each treated type of premolar were computed and compared using ANSYS. The measured damping constants beta were 0.75 x 10(-5) for the unprepared premolars, 0.69 x 10(-5) for the root-filled premolars with coronal restoration, and 0.72 x 10(-5) for the cast Co-Cr post-core restored premolars. The unprepared intact premolars demonstrated the highest stress dissipation effects with a ratio of 29.3 per cent at the middle root opposite to the loading side. However, no stress dissipation effects were found in the premolars that had been restored with the cast Co-Cr post-core system. The FE analysis showed that metallic post treatment attenuated the damping properties of the premolar. The effects of damping on stress concentration were significantly lower in restored premolars than in untreated vital premolars. These findings suggest that future research on post material should take the damping property into consideration.

Phenotype-genotype interactions on renal function in type 2 diabetes: an analysis using structural equation modelling

AIMS/HYPOTHESIS

Cardiovascular and renal diseases share common risk factors. We used structural equation modelling (SEM) to evaluate the independent and combined effects of phenotypes and genotypes implicated in cardiovascular diseases on renal function in type 2 diabetes.

METHODS

1,188 type 2 diabetic patients were stratified into high-risk and low-risk groups according to bimodal distributions of the logarithmically transformed (log(e)) urinary albumin:creatinine ratio and plasma creatinine levels. Models for these groups, comprising continuous and non-ranking categorical data, were developed separately to evaluate the inter-relationships among measured variables and latent factors using non-linear SEMs, Bayesian estimation and model selection as assessed by a goodness-of-fit statistic.

RESULTS

Inter-correlated measured variables (obesity, glycaemia, lipid, blood pressure) and variants of the genes encoding endothelial nitric oxide synthase (NOS), beta-adrenergic receptor (ADRB), components of the renin-angiotensin system (RAS) and lipid metabolism were loaded onto their respective latent factors of phenotypes and genotypes. In addition to direct and indirect effects, latent factors of obesity, lipid and BP interacted with latent factors of ADRB and RAS genotypes to influence renal function. Together with variants of the genes encoding peroxisome proliferator-activated receptor gamma, atrial natriuretic peptide, adducin, G protein beta(3) subunit, epithelial sodium channel alpha subunit and matrix metallopeptidase 3, these parameters explained 39-80% of the variance in renal function in the high-risk and low-risk models.

CONCLUSIONS/INTERPRETATION

SEM is a useful tool for confirming and quantifying multiple interactions of biological pathways with genetic determinants. The combined and interactive effects of blood pressure, lipid and obesity on renal function may have therapeutic implications, especially in type 2 diabetic individuals with genetic risk factors.

Age-associated alterations in cortical gray and white matter signal intensity and gray to white matter contrast

Prior studies have focused on patterns of brain atrophy with aging and age-associated cognitive decline. It is possible that changes in neural tissue properties could provide an important marker of more subtle changes compared to gross morphometry. However, little is known about how MRI tissue parameters are altered in aging. We created cortical surface models of 148 individuals and mapped regional gray and white matter T1-weighted signal intensities from 3D MPRAGE images to examine patterns of age-associated signal alterations. Gray matter intensity was decreased with aging with strongest effects in medial frontal, anterior cingulate, and inferior temporal regions. White matter signal intensity decreased with aging in superior and medial frontal, cingulum, and medial and lateral temporal regions. The gray/white ratio (GWR) was altered throughout a large portion of the cortical mantle, with strong changes in superior and inferior frontal, lateral parietal, and superior temporal and precuneus regions demonstrating decreased overall contrast. Statistical effects of contrast changes were stronger than those of cortical thinning. These results demonstrate that there are strong regional changes in neural tissue properties with aging and tissue intensity measures may serve as an important biomarker of degeneration.

Angular correlation between photoelectrons and auger electrons from K-shell ionization of neon

We have used cold target recoil ion momentum spectroscopy to study the continuum correlation between the photoelectron of core-photoionized neon and the subsequent Auger electron. We observe a strong angular correlation between the two electrons. Classical trajectory Monte Carlo calculations agree quite well with the photoelectron energy distribution that is shifted due to the potential change associated with Auger decay. However, a striking discrepancy results in the distribution of the relative angle between Auger and photoelectron. The classical model predicts a shift in photoelectron flux away from the Auger emission direction, and the data strikingly reveal that the flux is lost rather than diverted, indicating that the two-step interpretation of photoionization followed by Auger emission is insufficient to fully describe the core-photoionization process.

Diffractive grating structure for coherent light source production

A diffractive structure of cavities is designed to produce resonances at very high frequencies. This type of cavity structure may be useful for producing controllable coherent synchrotron radiation by microbunching the particle beam.

3-D diffusion tensor MRI anisotropy content-adaptive finite element head model generation for bioelectromagnetic imaging

Realistic finite element (FE) head models have been successfully applied to bioelectromagnetic problems due to a realistic representation of arbitrary head geometry with inclusion of anisotropic material properties. In this paper, we propose a new automatic FE mesh generation scheme to generate a diffusion tensor MRI (DT-MRI) white matter anisotropy content-adaptive FE head model. We term this kind of mesh as wMesh. With this meshing technique, the anisotropic electrical conductivities derived from DT-MRIs can be best incorporated into the model. The influence of the white matter anisotropy on the EEG forward solutions has been studied via our wMesh head models. The scalp potentials computed from the anisotropic wMesh models against those of the isotropic models have been compared. The results describe that there are substantial changes in the scalp electrical potentials between the isotropic and anisotropic models, indicating that the inclusion of the white matter anisotropy is critical for accurate computation of E/MEG forward and inverse solutions. This fully automatic anisotropy-adaptive wMesh meshing scheme could be useful for modeling of individual-specific FE head models with better incorporation of the white matter anisotropic property towards bioelectromagnetic imaging.

Metabolic syndrome and quality of life (QOL) using generalised and obesity-specific QOL scales

OBJECTIVES

We investigated the association between metabolic syndrome (MS) and health-related quality of life (HRQOL) assessed using generalised and obesity-specific QOL instruments.

METHODS

We recruited 456 outpatients [age: 19-81 years, body mass index (BMI): 16.3-36.7 kg/m2] in the primary care division from 12 general hospitals in Korea. HRQOL was measured using EuroQol comprising the health states descriptive system (EQ-5D) and visual analogue scale (EQ-VAS) as a general instrument. The Korean Obesity-related QOL scale (KOQOL) composed of six domains was used as a disease-specific QOL instrument. MS was defined on the basis of International Diabetes Federation (IDF) criteria with Korean-specific waist circumference cutoffs (men: 90 cm, women: 85 cm).

RESULTS

Subjects with MS displayed significantly higher impairment of EQ-5D and KOQOL. Binary logistic regression analysis of MS patients with controls for age, gender, smoking, alcohol, exercise, education, income, marital status and medication history disclosed odds ratio (OR) values of 2.13 (1.33-3.41) for impaired total KOQOL, 2.07 (1.31-3.27) for impaired physical health, 1.63 (1.03-2.60) for impaired work-related health, 2.42 (1.45-4.04) for impaired routine life, 2.08 (1.27-3.40) for impaired sexual life and 2.56 (1.59-4.11) for diet distress. Among the EQ-5D dimensions, only pain/discomfort displayed a significantly increased OR of 1.60 (1.01-2.56) in MS group.

CONCLUSIONS

Subjects with MS displayed a significantly impaired HRQOL compared with those without MS. MS and HRQOL were more strongly associated in obesity-specific QOL than in generalised QOL.

Multipurpose DVD pick-up scanner for analysis of microfluidics and micromechanical structures

Microfluidics has become increasingly prevalent and has founded widespread use in various applications such as biomedical applications (diagnostics, therapeutics, and cell/tissue engineering), inkjet head, and fuel cells etc. The issue of inspection and characterization of microfluidics has emerged as a major consideration in design, fabrication, and optical detection of devices. In this paper, we characterize the mixing flow pattern by diffusion, when two flows are combined in microchannel, using an optical scanner based on a DVD pick-up module, which is widely used in optical storage. Using Cy5.5 dye, we measure the fluorescent intensity that represents fluidic characteristics in Y-microchannel with 1 mum resolution and compare experimental results with computational fluid dynamics (CFD) simulation ones. Si based microstructures are measured using different optical reflective paths to the optical scanner with respect to the surface topologies. It is shown that the proposed optical scanner can be effectively and versatilely used to observe microfluidic characteristics and to measure the surface profiles of microstructures, being a cost-effective alternative device to conventional epifluorescent microscopes using high resolution CCD camera and interferometers.

The synthesis and characterization of [(124)I]IMPY, a thioflavin-S derivative, in transgenic mouse models of Alzheimer's disease

6-[(124)I]iodo-2-(4'-N,N-dimethylamino)-phenylimidazo[1,2-a]pyridine ([(124)I]IMPY) was synthesized and characterized as a positron-emitting probe to identify Alzheimer's disease in transgenic mouse models. A significant reduction in radioactivity retention in the hippocampus and frontal cortex by co-incubation with nonradioactive IMPY was observed. Highly specific retention of radioactivity in beta-amyloid-rich regions of brain sections was also noted. This study demonstrated that [(124)I]IMPY was a promising probe for the mouse model and may be useful for positron emission tomography to image beta-amyloid plaques in the human brain.

Significant invasion depth of early oral tongue cancer originated from the lateral border to predict regional metastases and prognosis

In oral tongue cancer, tumor depth is crucial for cervical lymph node metastasis. There is no standardized method to predict tumor invasion or deciding who should undergo selective neck dissection. In this study, calculated MRI invasion depth was compared with histopathologic (HP) invasion depth to find a correlation, and determine a cutoff value of invasion depth that predicts occult neck node metastasis. 50 patients, diagnosed with T1 or T2 oral tongue cancer originating from the lateral border of the tongue, underwent MRI screening and received surgical excision as primary treatment. MRI and HP invasion depths were compared and the cutoff value determined. The invasion depth to determine the presence of nodal metastasis where summation of specificity and sensitivity was greatest was 8.5mm HP, 10.5mm in T1 weighted enhanced axial image, and 11.5mm in T2 weighted MRI axial image. The relation coefficient of T2 weighted MRI invasion depth and HP depth was 0.851, and accuracy 84%, all of which showed higher correlation compared with T1 weighted enhanced axial image. HP depth was significantly correlated with survival rate. The measurement of invasion depth using MRI is a prerequisite for determining a surgical plan in early oral tongue cancer.

Search for a light pseudoscalar particle in the decay K_{L};{0}-->pi;{0}pi;{0}X

We performed a search for a light pseudoscalar particle X in the decay K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma with the E391a detector at KEK. Such a particle with a mass of 214.3 MeV/c;{2} was suggested by the HyperCP experiment. We found no evidence for X and set an upper limit on the product branching ratio for K_{L};{0}-->pi;{0}pi;{0}X, X-->gammagamma of 2.4x10;{-7} at the 90% confidence level. Upper limits on the branching ratios in the mass region of X from 194.3 to 219.3 MeV/c;{2} are also presented.

Cowpea bruchid midgut transcriptome response to a soybean cystatin--costs and benefits of counter-defence

The insect digestive system is the first line of defence protecting cells and tissues of the body from a broad spectrum of toxins and antinutritional factors in its food. To gain insight into the nature and breadth of genes involved in adaptation to dietary challenge, a collection of 20 352 cDNAs was prepared from the midgut tissue of cowpea bruchid larvae (Callosobruchus maculatus) fed on regular diet and diets containing antinutritional compounds. Transcript responses of the larvae to dietary soybean cystatin (scN) were analysed using cDNA microarrays, followed by quantitative real-time PCR (RT-PCR) confirmation with selected genes. The midgut transcript profile of insects fed a sustained sublethal scN dose over the larval life was compared with that of insects treated with an acute high dose of scN for 24 h. A total of 1756 scN-responsive cDNAs was sequenced; these clustered into 967 contigs, of which 653 were singletons. Many contigs (451) did not show homology with known genes, or had homology only with genes of unknown function in a Blast search. The identified differentially regulated sequences encoded proteins presumptively involved in metabolism, structure, development, signalling, defence and stress response. Expression patterns of some scN-responsive genes were consistent in each larval stage, whereas others exhibited developmental stage-specificity. Acute (24 h), high level exposure to dietary scN caused altered expression of a set of genes partially overlapping with the transcript profile seen under chronic lower level exposure. Protein and carbohydrate hydrolases were generally up-regulated by scN whereas structural, defence and stress-related genes were largely down-regulated. These results show that insects actively mobilize genomic resources in the alimentary tract to mitigate the impact of a digestive protease inhibitor. The enhanced or restored digestibility that may result is possibly crucial for insect survival, yet may be bought at the cost of weakened response to other stresses.

Factors affecting the predictability of SRK II in patients with normal axial length undergoing phacoemulsification surgery

INTRODUCTION

This study aims to evaluate the factors affecting the accuracy of biometry assessment using the SRK II formula in predicting the refractive outcome after uneventful cataract surgery by phacoemulsification for eyes within the normal range of axial lengths.

METHODS

A retrospective review of 100 consecutive cases of uncomplicated phacoemulsification surgery performed by two surgeons from January to September 2005 in a single centre was done. Eyes with axial length greater than or equal to 22.5 mm and less than 24.5 mm were included in the study. The error of prediction was calculated by actual postoperative refractive error minus the refraction target. A comparison was made between the low predictability (prediction error more than 0.50 dioptres [D]) and high predictability (prediction error less than or equal to 0.50 D) groups of eyes. Statistical analysis was performed.

RESULTS

A total of 267 case notes were reviewed, of which 100 met the inclusion criteria. The mean age was 68.3 years, with a mean keratometric reading of 43.94 +/- 1.27 D and mean axial length of 23.38 +/- 0.51 mm. The mean IOL power used was 21.77 +/- 1.50 D. The mean error was +0.25 +/- 0.67 (range -1.58 to +1.80) D, with the standard error of mean 0.669. 45 percent of the patients were within 0.5 D of the predicted refractive error and 83 percent were within 1.0 D. There was no difference in preoperative corneal astigmatism, mean keratometry, axial length, age or gender of the patient, laterality of the operated eye and intraocular lens power between the low and high predictability groups. There was a negative correlation between the axial length and prediction error.

CONCLUSION

SRK II is reliable in the prediction of the refractive outcome in normal axial length eyes. The findings in our study are comparable to those found in previous studies. We found a negative correlation between axial length and prediction error, even within the range of normal axial length eyes.

Spleen-preserving distal pancreatectomy

INTRODUCTION

Splenectomy is routinely performed in conventional distal pancreatectomies. Spleen removal with its possible sequelae of infections and haematological complications has prompted the development of spleen-preserving techniques. This study aimed to evaluate the safety and clinical outcomes of distal pancreatectomy with preservation of the spleen.

METHODS

A retrospective review of 24 consecutive patients who underwent spleen-preserving distal pancreatectomy in a tertiary care hospital was conducted.

RESULTS

There were 17 female and seven male patients, and the mean age was 47 (range 14-77) years. Median American Society of Anesthesiologists score was II (range I-III) . The indications were as follows : mucinous cystadenoma (n = 7), serous cystadenoma (n = 6), insulinoma (n = 3), intraductal papillary mucinous tumour (n = 2), pseudocyst (n = 3), papillary cystic adenoma (n = 1), neuroendocrine neoplasm (n = 1), and metastatic carcinoma of the thyroid (n = 1). Two patients developed postoperative pancreatic fistula and another two patients developed postoperative ileus with spontaneous resolution. Mean operative time was 172 (range 105-250) minutes. Mean length of postoperative hospital stay was 6.7 (range 5-11) days. There was no perioperative mortality in this series.

CONCLUSION

Spleen-preserving distal pancreatectomy can be safely performed with low morbidity, and should be considered in the surgical management of distal pancreatic disease.

Laparoscopic resection of splenic artery aneurysm with preservation of splenic function

We report a 59-year-old woman who had a successful laparoscopic resection of a splenic artery aneurysm. The common treatment for this condition is radiological embolisation or splenectomy. Laparoscopic resection of the splenic artery aneurysm with preservation of good splenic function over the long-term is presented.

Cost and effectiveness of treatments for mild-to-moderate bleeding episodes in haemophilia patients with inhibitors in Korea

First-line treatment for mild-to-moderate bleeding episodes in patients with haemophilia and inhibitors in Korea is currently activated prothrombin complex concentrate (aPCC) with recombinant activated factor VII (rFVIIa) as second-line therapy or as a last resort. The aim of this study was to estimate the cost and effectiveness of aPCC vs. rFVIIa for treating mild-to-moderate bleeds in inhibitor patients from the Korean reimbursement authorities' perspective. Clinical outcomes and resource utilization data (number of doses, average dose, number of outpatient visits, inpatient stays, ambulance transport and concomitant medications) were collected from an observational study involving four Korean paediatric haemophilia centres. Cost-effectiveness was modelled using a decision analysis approach and sensitivity analyses undertaken. rFVIIa was a more effective haemostatic therapy (87.1% efficacy in bleed resolution) than aPCC (64.0%). rFVIIa effected more rapid haemostasis, resolving bleeding in a mean of 6.6 h vs. 25.2 h for aPCC. Fewer rFVIIa doses were required per bleed vs. aPCC (means 1.7 and 2.3). Mean total direct medical costs from bleed initiation to cessation were estimated at Korean Won (KRW)12 460 thousand (US$12 311) for rFVIIa given as first-line therapy and KRW18 304 thousand (US$18 085) for aPCC given as first-line therapy. Sensitivity analyses confirmed the cost-effectiveness of rFVIIa vs. aPCC given as first-line therapy. In Korea, use of rFVIIa as first-line therapy for treatment of mild-to-moderate bleeding episodes in inhibitor patients is both clinically effective and cost-effective compared with initial aPCC treatment. rFVIIa should be considered as the first-line treatment for mild-to-moderate bleeding episodes in patients with haemophilia and inhibitors in Korea.

Structure-based classification of 45 FK506-binding proteins

The FK506-binding proteins (FKBPs) are a unique group of chaperones found in a wide variety of organisms. They perform a number of cellular functions including protein folding, regulation of cytokines, transport of steroid receptor complexes, nucleic acid binding, histone assembly, and modulation of apoptosis. These functions are mediated by specific domains that adopt distinct tertiary conformations. Using the Threading/ASSEmbly/Refinement (TASSER) approach, tertiary structures were predicted for a total of 45 FKBPs in 23 species. These models were compared with previously characterized FKBP solution structures and the predicted structures were employed to identify groups of homologous proteins. The resulting classification may be utilized to infer functional roles of newly discovered FKBPs. The three-dimensional conformations revealed that this family may have undergone several modifications throughout evolution, including loss of N- and C-terminal regions, duplication of FKBP domains as well as insertions of entire functional motifs. Docking simulations suggest that additional sequence segments outside FKBP domains may modulate the binding affinity of FKBPs to immunosuppressive drugs. The docking models also indicate the presence of a helix-loop-helix (HLH) region within a subset of FKBPs, which may be responsible for the interaction between this group of proteins and nucleic acids.

Evaluation of BRCA1 and BRCA2 mutations and risk-prediction models in a typical Asian country (Malaysia) with a relatively low incidence of breast cancer

INTRODUCTION

The cost of genetic testing and the limited knowledge about the BRCA1 and BRCA2 genes in different ethnic groups has limited its availability in medium- and low-resource countries, including Malaysia. In addition, the applicability of many risk-assessment tools, such as the Manchester Scoring System and BOADICEA (Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm) which were developed based on mutation rates observed primarily in Caucasian populations using data from multiplex families, and in populations where the rate of breast cancer is higher, has not been widely tested in Asia or in Asians living elsewhere. Here, we report the results of genetic testing for mutations in the BRCA1 or BRCA2 genes in a series of families with breast cancer in the multi-ethnic population (Malay, Chinese and Indian) of Malaysia.

METHOD

A total of 187 breast cancer patients with either early-onset breast cancer (at age </= 40 years) or a personal and/or family history of breast or ovarian cancer were comprehensively tested by full sequencing of both BRCA1 and BRCA2. Two algorithms to predict the presence of mutations, the Manchester Scoring System and BOADICEA, were evaluated.

RESULTS

Twenty-seven deleterious mutations were detected (14 in BRCA1 and 13 in BRCA2), only one of which was found in two unrelated individuals (BRCA2 490 delCT). In addition, 47 variants of uncertain clinical significance were identified (16 in BRCA1 and 31 in BRCA2). Notably, many mutations are novel (13 of the 30 BRCA1 mutations and 24 of the 44 BRCA2). We report that while there were an equal proportion of BRCA1 and BRCA2 mutations in the Chinese population in our study, there were significantly more BRCA2 mutations among the Malays. In addition, we show that the predictive power of the BOADICEA risk-prediction model and the Manchester Scoring System was significantly better for BRCA1 than BRCA2, but that the overall sensitivity, specificity and positive-predictive value was lower in this population than has been previously reported in Caucasian populations.

CONCLUSION

Our study underscores the need for larger collaborative studies among non-Caucasian populations to validate the role of genetic testing and the use of risk-prediction models in ensuring that the other populations in the world may also benefit from the genomics and genetics era.

Molecular characterization of T-type Ca(2+) channels responsible for low threshold spikes in hypothalamic paraventricular nucleus neurons

The hypothalamic paraventricular nucleus (PVN) is composed of functionally heterogeneous cell groups, possessing distinct electrophysiological properties depending on their functional roles. Previously, T-type Ca(2+) dependent low-threshold spikes (LTS) have been demonstrated in various PVN neuronal types, including preautonomic cells. However, the molecular composition and functional properties of the underlying T-type Ca(2+) channels have not been characterized. In the present study, we combined single cell reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry and patch-clamp recordings to identify subtypes of T-type Ca(2+) channels expressed in PVN cells displaying LTS (PVN-LTS), including identified preautonomic neurons. LTS appeared at the end of hyperpolarizing pulses either as long-lasting plateaus or as short-lasting depolarizing humps. LTS were mediated by rapidly activating and inactivating T-type Ca(2+) currents and were blocked by Ni(2+). Single cell RT-PCR and immunohistochemical studies revealed Cav3.1 (voltage-gated Ca(2+) channel) as the main channel subunit detected in PVN-LTS neurons. In conclusion, these data indicate that Cav3.1 is the major subtype of T-type Ca(2+) channel subunit that mediates T-type Ca(2+) dependent LTS in PVN neurons.

Functional expression of an insect cathepsin B-like counter-defence protein

Insects are capable of readjusting their digestive regimes in response to dietary challenge. Cowpea bruchids (Callosobruchus maculatus) strongly induce C. maculatus cathepsin B-like cysteine protease 1 (CmCatB1) transcripts when fed diet containing a soybean cysteine protease inhibitor soyacystatin N (scN). CmCatB1 shares significant sequence similarity with cathepsin B-like cysteine proteases. In this study, we isolated another cDNA, namely CmCatB2 that encodes a protein sequence otherwise identical to CmCatB1, but lacking a 70-amino-acid internal section. CmCatB1 and CmCatB2 probably resulted from alternate splicing events. Only the CmCatB1 transcript, however, exhibited differential expression in response to dietary scN. Further, this expression was only detectable in larvae, which is the developmental stage associated with food ingestion. The scN-activated and developmentally regulated CmCatB1 expression pattern suggests it may have a unique function in insect counter-defence against antinutritional factors. Heterologously expressed recombinant CmCatB1 protein exhibited enzymatic activity in a pH-dependent manner. Activity of the protein was inhibited by both the cysteine protease inhibitor E-64 and the cathepsin B-specific inhibitor CA-074, verifying its cathepsin B-like cysteine protease nature. Interestingly, the enzymatic activity was unaffected by the presence of scN. Together, we have provided functional evidence suggesting that CmCatB1 confers inhibitor-insensitive enzymatic activity to cowpea bruchids, which is crucial for insect survival when challenged by dietary protease inhibitors.

Search for the Decay K L0-->pi0nu nu[over]

We performed a search for the K L0-->pi0nu nu[over] decay at the KEK 12-GeV proton synchrotron. No candidate events were observed. An upper limit on the branching ratio for the decay was set to be 6.7 x 10(-8) at the 90% confidence level.

[Herpes simplex virus type 1 ICP27 induces apoptotic cell death by increasing intracellular reactive oxygen species]

HSV-1 ICP27, an immediate early protein of herpes simplex virus type 1, is involved in viral replication, transcriptional activation, RNA stability, apoptosis, and reactivation from viral latency. The reactivation from viral latency is closely related to apoptosis and oxidative stress. To understand the effect of ICP27 upon apoptosis, we tested for cell death of ICP27-expressing cells (3-3) in the presence of hydrogen peroxide. Under oxidative stress, 3-3 cells were sensitive to death, displaying typical apoptosis features such as oligonucleosomal DNA fragmentation, chromatin condensation, and G0/G1 accumulation. To dissect the sensitizing mechanism of ICP27 in apoptosis, we analyzed the level of intracellular reactive oxygen species (ROS) in 3-3 cells. We found that 3-3 cells exhibited increased ROS levels compared to Vero cells devoid of ICP27. We also observed that the increased levels of intracellular ROS in 3-3 cells were caused by disturbances in antioxidant enzymes. In 3-3 cells, the elevated ROS increased the AP-1 activity, subsequently the expression of Bax increased, and the expression of Bcl2 was reduced. In addition, 3-3 cells were sensitive to various apoptotic agents. Taken together, these results indicate that HSV-I ICP27 sensitizes the cells to apoptosis by elevating the intracellular levels of ROS.