NME3 is a gatekeeper for DRP1-dependent mitophagy in hypoxia

NME3 is a member of the nucleoside diphosphate kinase (NDPK) family localized on the mitochondrial outer membrane (MOM). Here, we report a role of NME3 in hypoxia-induced mitophagy dependent on its active site phosphohistidine but not the NDPK function. Mice carrying a knock-in mutation in the Nme3 gene disrupting NME3 active site histidine phosphorylation are vulnerable to ischemia/reperfusion-induced infarction and develop abnormalities in cerebellar function. Our mechanistic analysis reveals that hypoxia-induced phosphatidic acid (PA) on mitochondria is essential for mitophagy and the interaction of DRP1 with NME3. The PA binding function of MOM-localized NME3 is required for hypoxia-induced mitophagy. Further investigation demonstrates that the interaction with active NME3 prevents DRP1 susceptibility to MUL1-mediated ubiquitination, thereby allowing a sufficient amount of active DRP1 to mediate mitophagy. Furthermore, MUL1 overexpression suppresses hypoxia-induced mitophagy, which is reversed by co-expression of ubiquitin-resistant DRP1 mutant or histidine phosphorylatable NME3. Thus, the site-specific interaction with active NME3 provides DRP1 a microenvironment for stabilization to proceed the segregation process in mitophagy.

The novel role of ER protein TXNDC5 in the pathogenesis of organ fibrosis: mechanistic insights and therapeutic implications

Fibrosis-related disorders account for an enormous burden of disease-associated morbidity and mortality worldwide. Fibrosis is defined by excessive extracellular matrix deposition at fibrotic foci in the organ tissue following injury, resulting in abnormal architecture, impaired function and ultimately, organ failure. To date, there lacks effective pharmacological therapy to target fibrosis per se, highlighting the urgent need to identify novel drug targets against organ fibrosis. Recently, we have discovered the critical role of a fibroblasts-enriched endoplasmic reticulum protein disulfide isomerase (PDI), thioredoxin domain containing 5 (TXNDC5), in cardiac, pulmonary, renal and liver fibrosis, showing TXNDC5 is required for the activation of fibrogenic transforming growth factor-β signaling cascades depending on its catalytic activity as a PDI. Moreover, deletion of TXNDC5 in fibroblasts ameliorates organ fibrosis and preserves organ function by inhibiting myofibroblasts activation, proliferation and extracellular matrix production. In this review, we detailed the molecular and cellular mechanisms by which TXNDC5 promotes fibrogenesis in various tissue types and summarized potential therapeutic strategies targeting TXNDC5 to treat organ fibrosis.

Synchrotron X-Ray Analysis and Morphology Evidence for Stereo-Assemblies of Periodic Aggregates in Poly(3-hydroxybutyrate) with Unusual Photonic Iridescence

3D morphology of poly(3-hydroxybutyrate) (PHB), crystallized in the presence of diluents of poly(1,3-trimethylene adipate) and poly(ethylene oxide), is probed using a novel approach coupled with selective etching. For interpreting the mechanisms of crystal periodic aggregation, various microscopic techniques and synchrotron microbeam X-ray analysis are used to observe the top surface in connection with the 3D crystal assemblies. Periodic grating architectures, with the cross-bar pitch exactly matching with the optical band spacing, are proved in banded PHB. The crystals under the ridge branch out to spawn finer crystals orienting/bending horizontally underneath the valley band, repeating till species drainage or impingement. The grating structure in the banded PHB resembles many nature's iridescence crystals and is further proved by photonic reflection results as a critical breakthrough novel finding.

Integrated optical chip for a high-resolution, single-resonance-mode x-ray monochromator system

An integrated optical chip that minimizes the size of the energy-tuning single-resonance-mode x-ray monochromator system into a 3cm×5cm silicon wafer is proposed. A Fabry-Perot x-ray resonator and two back-reflecting Si mirrors are employed on the wafer as the optical components, where Si(12 4 0) back reflection is used for both Fabry-Perot resonance and re-diffraction of the x-ray beams from the resonator in the incident direction. We can achieve an energy bandwidth of 3.4 meV in single-mode x rays and tune the energy by temperature variation. Such Si chips can be readily employed at the synchrotron beamlines and conventional x-ray laboratories for high-resolution investigations.

Glial response to hypoxia in mutants of NPAS1/3 homolog Trachealess through Wg signaling to modulate synaptic bouton organization

Synaptic structure and activity are sensitive to environmental alterations. Modulation of synaptic morphology and function is often induced by signals from glia. However, the process by which glia mediate synaptic responses to environmental perturbations such as hypoxia remains unknown. Here, we report that, in the mutant for Trachealess (Trh), the Drosophila homolog for NPAS1 and NPAS3, smaller synaptic boutons form clusters named satellite boutons appear at larval neuromuscular junctions (NMJs), which is induced by the reduction of internal oxygen levels due to defective tracheal branches. Thus, the satellite bouton phenotype in the trh mutant is suppressed by hyperoxia, and recapitulated in wild-type larvae raised under hypoxia. We further show that hypoxia-inducible factor (HIF)-1α/Similar (Sima) is critical in mediating hypoxia-induced satellite bouton formation. Sima upregulates the level of the Wnt/Wingless (Wg) signal in glia, leading to reorganized microtubule structures within presynaptic sites. Finally, hypoxia-induced satellite boutons maintain normal synaptic transmission at the NMJs, which is crucial for coordinated larval locomotion.

Design, fabrication, and characterization of a multidimensional prism

In this research, a novel multidimensional prism with three distinct 45°, 135°, and 225° inclined optical surfaces were realized by using inclined exposure technology and SU-8 polymer. To obtain a smooth surface, the solvent loss percentage and temperature of post-exposure bake (PEB) are two key factors that need to be well controlled during fabrication. The experimental results showed that surface roughness can achieve 42.9±7.6  nm, which is one-tenth of high-precision machining or molding processes, under the processes parameter combinations of PEB temperature, and solvent loss percentage is 95°C and 82.86%, respectively. The surface reflectivity of the prism was measured by using a He-Ne laser, and reflectivity of the prism surface without and with aluminum metal film was 90.8% and 91.8%, respectively. The slight difference of reflectivity means that a prism with a high-quality inclined surface can be realized. The functionality of the prism for three lasers was also verified with RGB lasers, and it successfully demonstrated the feasibility of application of a multidimensional prism on the optical system. Finally, the utilization of inclined exposure technology not only monolithically integrates three 45° inclined surfaces into one prism without precision assembly but also greatly simplifies the fabrication processes to further reduce the cost. This component and technology can also be applied to medical endoscope systems if the SU-8 is replaced by PDMS or other biocompatible materials using a molding process. These results provide the potential for mass manufacturing, which is of considerable value to the optical markets.

High-resolution monochromator using a high-efficiency single-mode x-ray resonator at Laue incidence

We report a high-resolution and high-efficiency monochromator with energy resolution, ΔE/E∼2.08*10^-7, utilizing a hard x-ray single-mode Fabry-Perot (FP) resonator at Laue incidence at 14.4388 keV. Instead of using multiple-crystal diffraction via several asymmetric-cut crystals, a 3 meV single-peak is generated from the interference of a Si-made two-plate cavity with a thickness of 70 μm and a gap of 45 μm, where a (0-40) Laue reflection is used to excite the backreflection (12 4 0) for the enhancement of the FP efficiency. Due to the large angular acceptance of (12 4 0) and (0-40), the energy tunability can be achieved by changing the incident angle into the resonator. The application of x-ray resonators at Laue incidence as a monochromator can be further implemented to x-ray optics.

High-resolution interference-monochromator for hard X-rays

An X-ray interference-monochromator combining a Fabry-Perot resonator (FPR) and a double-crystal monochromator (DCM) is proposed and realized for obtaining single-mode X-rays with 3.45 meV energy resolution. The monochromator is based on the generation of cavity interference fringes from a FPR and single-mode selection of the transmission spectrum by a DCM of a nearly backward symmetric reflection geometry. The energy of the monochromator can be tuned within 2500 meV(= ΔE) by temperature control of the FPR and the DCM crystals in the range of ΔT = 70 K at room temperature. The diffraction geometry and small size of the optical components used make the interference-monochromator very easy to be adapted in modern synchrotron beamlines and X-ray optics applications.

X-ray multi-beam resonant diffraction analysis of crystal symmetry for layered perovskite YBaCuFeO5

The open question of crystal symmetry for YBaCuFeO5, still under debate, is resolved by using diffraction anomalous fine structure and resonant multi-beam X-ray diffraction at the Fe and Cu K edges. The different asymmetric intensity distributions observed at 7, 7.1305 and 8.9945 keV give direct evidence that the space group of YBaCuFeO5 should be P4/mmm with the distance between Cu and apical O atoms longer than that between Fe and O atoms. This approach provides a direct way to resolve detailed structural symmetry which is indeterminate in conventional Bragg diffraction.

Single-mode selection for hard x-ray cavity resonance

Single-mode selection is realized for hard x-ray cavity resonance using a three-mirror crystal device. The developed device consists of two coupled Si Fabry-Perot resonators (FPRs) and uses (12 4 0) backward diffraction to reflect back and forth the incident 14.4388 keV x-ray beam. The coupling between the two cavities gives an effective single-mode spectrum with a bandwidth of 0.81 meV. This method can be used to enhance the longitudinal coherent length without affecting transverse coherence, and is potentially useful in generating nearly total coherent beams in synchrotron or free-electron laser facilities.

Performance enhancement using a non-uniform vertical electric field and polymer networks for in-plane switching of multi-pretilt, vertically aligned liquid crystal devices

A simple and reproducible alignment method for fabricating vertically aligned (VA) liquid crystal (LC) cells with a multi-pretilt structure is developed. A non-uniform vertical electric field is employed in the LC/monomer mixed cells during the photocuring process, and two pretilt domains with a functional small pretilt angle (∼1.6°) in the stabilized VA LC/polymer cells are achieved. The enhanced electro-optical performance of the cell driven by an in-plane switching field is demonstrated. Compared to the pure cell, the 2 wt.% pretilt angle cell shows 36%, 64%, and 76% improvement in the optical switch, the gray-level rise time, and the gray-level fall time responses, respectively, which are obtained at a low driving voltage (≤12  V). When applied to LC devices, the proposed method not only effectively benefits the LC molecular alignment, but it also significantly boosts the electro-optical performance.

Study La0.5Sr1.5MnO4with Multi-Beam X-ray Diffraction

We have used resonant multi-beam diffraction with the primary reflections G=(h/2 h/2 0) and G=(h/4 h/4 0) (h is an odd number) to investigate the charge ordering and Jahn-Teller distortion, respectively, in La0.5Sr1.5MnO4 low temperature phase. While the Renninger scans with G=(h/2 h/2 0) shows several Aulfhellung-type four-beam diffraction, most of the multi-beam diffraction with G=(h/4 h/4 0) has an Umweganregung-type nature. A detailed study of multi-beam diffraction anomalous fine structure (M-DAFS) of (0 0 0)/(3/2 3/2 0)/(1 -1 0)/(5/2 1/2 0) OUT diffraction is carried out. Its triplet invariant phase approach 1800when the x-ray energy is tuned away from manganese K-edge, and approach 900when the x-ray energy is tuned on manganese K-edge. In other words, its multi-beam diffraction profile shows strong asymmetry when (3/2 3/2 0) diffraction intensity is dominated by Jahn-Teller distortion, and becomes more symmetric when charge ordering dominated. This characteristic can be successfully simulated by tensor form dynamical x-ray diffraction theory accompanied with FDMNES software [1] calculations.

Post ischemia intermittent hypoxia induces hippocampal neurogenesis and synaptic alterations and alleviates long-term memory impairment

Adult hippocampal neurogenesis is important for learning and memory, especially after a brain injury such as ischemia. Newborn hippocampal neurons contribute to memory performance by establishing functional synapses with target cells. This study demonstrated that the maturation of hippocampal neurons is enhanced by postischemia intermittent hypoxia (IH) intervention. The effects of IH intervention in cultured neurons were mediated by increased synaptogenesis, which was primarily regulated by brain-derived neurotrophic factor (BDNF)/PI3K/AKT. Hippocampal neo-neurons expressed BDNF and exhibited enhanced presynaptic function as indicated by increases in the pSynapsin expression, synaptophysin intensity, and postsynapse density following IH intervention after ischemia. Postischemia IH-induced hippocampal neo-neurons were affected by presynaptic activity, which reflected the dynamic plasticity of the glutamatergic receptors. These alterations were also associated with the alleviation of ischemia-induced long-term memory impairment. Our results suggest that postischemia IH intervention rescued ischemia-induced spatial learning and memory impairment by inducing hippocampal neurogenesis and functional synaptogenesis via BDNF expression.

Design and fabrication of a novel prism for micro-optical system

This study presents a special k-type (45°, 135°) microprism structure design for the lateral-type semiconductor laser of optical systems. This study combines front- and back-side inclined exposure technology to develop a k-type microprism structure and replaces the optical prism manufactured through traditional machine processing or injection molding with a new polymer (thick-film negative photoresists) micro-optical prism structure. To obtain the optimal structural surface roughness (12-15 nm at 400  μm×400  μm area), the percentage of polymer material loss caused by the solvent was controlled. This roughness level meets Blu-ray specifications (λ/10, λ=405  nm).

Intermittent hypoxia after transient focal ischemia induces hippocampal neurogenesis and c-Fos expression and reverses spatial memory deficits in rats

BACKGROUND

Memory impairment is a frequent complication of brain ischemia. Neurogenesis is implicated in learning and memory and is regulated by the transcription factor c-Fos. Preconditioning intermittent hypoxia (IH) attenuates ischemia-related memory impairments, but it is not known whether post-ischemia IH intervention has a similar effect. We investigated the effects of post-ischemia IH on hippocampal neurogenesis and c-Fos expression as well as spatial learning and memory in rats.

METHODOLOGY/PRINCIPAL FINDINGS

Focal cerebral ischemia was induced in some rats by middle cerebral artery occlusion (MCAO), while other rats received sham MCAO surgery. Beginning a week later, half of the rats of each group received IH interventions (12% oxygen concentration, 4 hrs/d, for 7 d) and half received sham IH sessions. An additional group of rats received MCAO, IH, and injections of the neurogenesis-impairing agent 3'-AZT. Spatial learning and memory was measured in the Morris water maze, and hippocampal neurogenesis and c-Fos expression were examined. Hypoxia-inducible factor 1α (HIF-1α) and phosphorylated mitogen-activated protein kinase (pMAPK) were considered as possible mediators of IH-induced changes in neurogenesis and c-Fos expression. IH intervention following MCAO resulted in recovered spatial memory, increased hippocampal neurogenesis, and increased expression of c-Fos in newborn hippocampal cells. These effects were blocked by 3'-AZT. IH intervention following MCAO also was associated with increased hippocampal pMAPK and HIF-1α expression.

CONCLUSIONS/SIGNIFICANCE

IH intervention following MCAO rescued ischemia-induced spatial learning and memory impairments, likely by inducing hippocampal neurogenesis and c-Fos expression through mediators including pMAPK and HIF-1α.

The time window of intermittent hypoxia intervention after middle cerebral artery occlusion

It was known that preconditioning hypoxia can reduce the damage caused by ischemia. However, there was no study investigating the effects of intermittent hypoxia post ischemia. The purpose of this study was to investigate the time window for administering the hypoxia for beneficial effects after cerebral ischemic damage. According to the recovery days post transient middle cerebral occlusion (MCAO), the rats were randomly assigned to one of the 4 groups (n = 20 for each group, I, II, III, and IV). Rats were then assigned to one of the 2 subgroups (a and b). Rats in group Ia, IIa, IIIa, and IVa were exposed to 7 days of intermittent hypoxia (12% O2 for 4 hours per day) after recovery 1, 2, 3, and 7 days from MCAO, respectively. Rats in group Ib, IIb, IIIb, and IVb rested for 7 days in the same hypoxia chamber without hypoxia exposure after 1, 2, 3, and 7 days post MCAO, respectively. The mortality rate of rats received hypoxia after 1 day' and 2 days' recovery post MCAO was 40% (P = 0.087) and 10% (P = 0.5), respectively. The mean infarct volume of rats received hypoxia after 7 days' recovery was significantly less than that of the comparable control group (9.23 +/- 0.71% vs. 13.32 +/- 1.26%; P = 0.013), and no rats died in this group. In summary, intermittent hypoxia intervention for 7 days after 7 days of recovery post ischemia can reduce the infract volume, and does not increase the mortality rate. According to our results, we suggest that 7 days post ischemia may be the suitable time to begin the intermittent hypoxia intervention to enhance the recovery from cerebral ischemia.

In situ EXAFS investigation of carbon-supported Pt clusters under potential control

The transformation of carbon supported Pt clusters under potential control in 1M HClO4 solution was investigated by in-situ X-ray absorption spectroscopy measurements. Both XANES and EXAFS data are used to show the structure evolution of the Pt clusters at various potentials. It showed that the white line area and the edge energy increase with the applied potential in the range 0.1-1.5V. The coordination number of oxygen and platinum on the Pt/C electrode increases and decreases, respectively, with the applied potential. It is found that the size of Pt cluster does not grow during the electrode fabrication. However, the crystallization of Pt cluster occurs during the potential cycling.

Cigarette consumption in rural China: survey results from 3 provinces

OBJECTIVES

This study assessed cigarette consumption and its main determinants in rural China.

METHODS

A logistic regression model was used to analyze status of smoking, daily amount of smoking, and expense of cigarettes in rural China.

RESULTS

Approximately 57.1% of the males and 3.1% of the females were current smokers. The daily amount of smoking among smokers was 15.23 cigarettes, and their annual expenses were 227 yuan.

CONCLUSIONS

People in rural China consume fewer cigarettes and are less likely to smoke than those in urban areas. Education and occupation are 2 major factors that determine the likelihood of smoking in rural China.

Three-dimensional modelling of the catalytic domain of Streptococcus mutans glucosyltransferase GtfB

Glucosyltransferases (GtfB/C/D) of Streptococcus mutans, a pathogen for human dental caries, synthesize water-insoluble glucan through the hydrolysis of sucrose. Genetic and biochemical approaches have identified several active sites of these enzymes, but no three-dimensional (3D) structural evidence is yet available to elucidate the subdomain arrangement and molecular mechanism of catalysis. Based on a combined sequence and secondary structure alignment against known crystal structures of segments from closely related proteins, we propose here the 3D model of an N-terminal domain essential for the sucrose binding and splitting in GtfB. A Tim-barrel of (alpha/beta)(8) structural characteristics is revealed and the structural correlation for two peptides is described.

Children of working low-income families in California: does parental work benefit children's insurance status, access, and utilization of primary health care?

OBJECTIVE

To examine financial and nonfinancial access to care and utilization of primary health care services among children of working low-income families earning below 200 percent of the federal poverty level in California, and to compare them to children in nonworking low-income families and in families earning over 200 percent of poverty.

DATA SOURCES/STUDY SETTING

The 1994 National Health Interview survey weighted to reflect population estimates for California.

STUDY DESIGN

This cross-sectional study of 3,831 children under age 19 focuses on financial access, that is, the prevalence and continuity of health insurance coverage; structural access, including the presence of a usual source of care, the predominant care source, its responsiveness to patient's needs, and any indications of delayed or missed care; and utilization of health care measured by the presence of an outpatient doctor's visit and the mean number of visits relative to child health status.

DATA COLLECTION

The study uses secondary analysis.

FINDINGS

Compared to children of nonworking low-income parents and to nonpoor children, children of working low-income parents were more likely to be uninsured (32.1 percent versus 15.6 percent and 10.3 percent, p = .0001) and to experience disruptions in insurance coverage (p = .0009). These differences persisted after controlling for other covariates in multivariate analyses. Children of working low-income parents did not differ significantly from children of nonworking low-income parents on measures of structural access or utilization, after adjusting for other covariates. However, they differed significantly from nonpoor children on structural access and utilization, and these differences mostly persisted after adjusting for other covariates (odds ratios from 1.5 to 2.9). Similar patterns were observed when children of full-time, year-round working parents with low earnings were compared with the two reference populations.

CONCLUSION

Children in working low-income families in California have some of the worst access problems. Even full attachment to the workforce does not guarantee health insurance benefits, access to care, or improved health care use for children of low-income parents. These children are not better off than other low-income children of nonworking parents and are much worse off than nonpoor children. Expansion of health insurance coverage through Healthy Families and Medi-Cal, and attention to nonfinancial barriers to care for working low-income families may help to reduce these disparities.

Differentiation of lactate-fermenting, gas-producing Clostridium spp. isolated from milk

Endospores of Clostridium spp. capable of producing gas in a lactate-containing medium were enumerated from 14 pasteurized milk samples from Wisconsin cheese plants. Concentrations of endospores of lactate-fermenting, gas-producing Clostridium spp. were between 5.0 x 10(-2) and 1.7 x 10(0) MPN ml(-1). Concentrations of presumptive C. tyrobutyricum endospores (defined by subterminal endospore position and lactate dehydrogenase activity) were lower, not exceeding 2.0 x 10(-2) MPN ml(-1). Based on subterminal endospore position, lactate dehydrogenase activity, and a carbohydrate fermentation profile identical to C. tyrobutyricum strain ATCC 25755, five isolates (Ct) were initially characterized as C. tyrobutyricum, a known cause of late-blowing in high-pH cheeses. Twenty-eight other isolates (Cx) produced gas from lactate, but differed from ATCC 25755 in either endospore position, lactate dehydrogenase activity or carbohydrate fermentation profile. When inoculated at high concentrations in Gouda cheese, strain ATCC 25755, two Ct isolates and 18 Cx isolates tested produced gas during ripening. Among the five Ct isolates obtained and two reference strains confirmed as C. tyrobutyricum, there were four qualitatively different volatile organic acid byproduct profiles. Each of the two confirmed C. tyrobutyricum reference strains and five Ct isolates had distinct quantitative cell membrane fatty acid (CMFA) profiles. The Cx isolates represented 14 different volatile organic acid byproduct profiles and each isolate had a unique CMFA profile. Pulsed field gel electrophoresis (PFGE) of DNA from the two confirmed reference C. tyrobutyricum strains, four Ct and three Cx isolates, showed a low degree of relatedness. The results of this study suggest that a heterogeneous group of lactate-fermenting, gas-producing Clostridium spp. may be found in milk. Gas chromatographic analysis of volatile organic acid byproducts or CMFA, and PFGE of DNA are highly discriminating methods for differentiating Clostridium spp. that may cause late blowing in high-pH cheeses.

T-tube drainage for the treatment of high jejunal atresia

Since 1976, the authors have used T-tube drainage for the treatment of diaphragmatic type, high jejunal atresia. Twelve cases were operated on. All cases survived the operation. On the fourteenth to thirtieth postoperative day, T-tubes were removed when the dilated proximal intestine returned to normal size.

Adult Hirschsprung's disease

This report presents a series of 17 patients with adult Hirschsprung's disease treated at the National Taiwan University Hospital and its affiliated hospitals from 1965 to 1988. Adults with Hirschsprung's disease may present with symptoms and operative findings different from those of children with Hirschsprung's disease. The symptoms, signs, criteria for diagnosis, operative findings, and operative procedures are presented.