Construction of MoS2/C Hierarchical Tubular Heterostructures for High-Performance Sodium Ion Batteries

Molybdenum disulfide (MoS₂) has been considered to be a promising anode material for sodium ion batteries (SIBs), because of its high capacity and graphene-like layered structure. However, irreversible conversion reaction during the sodiation/desodiation process is a major problem that must be overcome before its practical applications. In this work, MoS₂/amorphous carbon (C) microtubes (MTs) composed of heterostructured MoS₂/C nanosheets have been developed via a simple template method. The existence of MoS₂/C heterointerface plays a key role in achieving high and stable performance by stabilizing the reaction products Mo and sulfide phases, providing fast electronic and Na⁺ ions diffusion mobility, and alleviating the volume change. MoS₂/C MTs exhibit a high reversible specific capacity of 563.5 mA h g^-1 at 0.2 A g^-1, good rate performance (520.5, 489.4, 452.9, 425.1, and 401.3 mA h g^-1 at 0.5, 1.0, 2.0, 5.0, and 10.0 A g^-1, respectively), and excellent cycling stability (484.9 mA h g^-1 at 2.0 A g^-1 after 1500 cycles).

Activated Amorphous Carbon With High-Porosity Derived From Camellia Pollen Grains as Anode Materials for Lithium/Sodium Ion Batteries

Carbonaceous anode materials are commonly utilized in the energy storage systems, while their unsatisfied electrochemical performances hardly meet the increasing requirements for advanced anode materials. Here, activated amorphous carbon (AAC) is synthesized by carbonizing renewable camellia pollen grains with naturally hierarchical structure, which not only maintains abundant micro- and mesopores with surprising specific surface area (660 m² g⁻¹), but also enlarges the interlayer spacing from 0.352 to 0.4 nm, effectively facilitating ions transport, intercalation, and adsorption. Benefiting from such unique characteristic, AAC exhibits 691.7 mAh g⁻¹ after 1200 cycles at 2 A g⁻¹, and achieves 459.7, 335.4, 288.7, 251.7, and 213.5 mAh g⁻¹ at 0.1, 0.5, 1, 2, 5 A g⁻¹ in rate response for lithium-ion batteries (LIBs). Additionally, reversible capacities of 324.8, 321.6, 312.1, 298.9, 282.3, 272.4 mAh g⁻¹ at various rates of 0.1, 0.2, 0.5, 1, 2, 5 A g⁻¹ are preserved for sodium-ion batteries (SIBs). The results reveal that the AAC anode derived from camellia pollen grains can display excellent cyclic life and superior rate performances, endowing the infinite potential to extend its applications in LIBs and SIBs.

Exploration of VPO4 as a new anode material for sodium-ion batteries

Carbon-coated VPO₄ nanoparticles embedded into a porous carbon matrix were synthesized via a facile sol-gel approach and investigated as a novel polyanion anode material for sodium-ion batteries. The VPO₄@carbon anode demonstrates excellent rate capability and superior cyclic stability (245.3 mA h g^-1 at 1000 mA g^-1 after 200 cycles).

Gestational Age at Birth and Brain White Matter Development in Term-Born Infants and Children

BACKGROUND AND PURPOSE

Studies on infants and children born preterm have shown that adequate gestational length is critical for brain white matter development. Less is known regarding how variations in gestational age at birth in term infants and children affect white matter development, which was evaluated in this study.

MATERIALS AND METHODS

Using DTI tract-based spatial statistics methods, we evaluated white matter microstructures in 2 groups of term-born (≥37 weeks of gestation) healthy subjects: 2-week-old infants (n = 44) and 8-year-old children (n = 63). DTI parameters including fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were calculated by voxelwise and ROI methods and were correlated with gestational age at birth, with potential confounding factors such as postnatal age and sex controlled.

RESULTS

Fractional anisotropy values, which are markers for white matter microstructural integrity, positively correlated (P < .05, corrected) with gestational age at birth in most major white matter tracts/regions for the term infants. Mean diffusivity values, which are measures of water diffusivities in the brain, and axial and radial diffusivity values, which are markers for axonal growth and myelination, respectively, negatively correlated (P < .05, corrected) with gestational age at birth in all major white matter tracts/regions excluding the body and splenium of the corpus callosum for the term infants. No significant correlations with gestational age were observed for any tracts/regions for the term-born 8-year-old children.

CONCLUSIONS

Our results indicate that longer gestation during the normal term period is associated with significantly greater infant white matter development (as reflected by higher fractional anisotropy and lower mean diffusivity, axial diffusivity, and radial diffusivity values); however, similar associations were not observable in later childhood.

Surface Modification of Na3V2(PO4)3 by Nitrogen and Sulfur Dual-Doped Carbon Layer with Advanced Sodium Storage Property

Nitrogen and sulfur dual-doped carbon layer wrapped Na₃V₂(PO₄)₃ nanoparticles (NVP@NSC) have been successfully fabricated by the facile solid-state method. In this hierarchical structure, the Na₃V₂(PO₄)₃ nanoparticles are well dispersed and closely coated by nitrogen and sulfur dual-doped carbon layer, constructing an effective and interconnected conducting network to reduce the internal resistance. Furthermore, the uniform coating layers alleviate the agglomeration of Na₃V₂(PO₄)₃ as well as mitigate the side reaction between electrode and electrolyte. Because of the excellent electron transfer mutually enhancing sodium diffusion for this extraordinary structure, the NVP@NSC composite delivers an impressive discharge capacity of 113.0 mAh g^-1 at 1 C and shows a capacity retention of 82.1% after 5000 cycles at an ultrahigh rate of 50 C, suggesting the remarkable rate capability and long cyclicity. Surprisingly, a reversible capacity of 91.1 mAh g^-1 is maintained after 1000 cycles at 5 C under the elevated temperature of 55 °C. The approach of nitrogen and sulfur dual-doped carbon-coated Na₃V₂(PO₄)₃ provides an effective and promising strategy to enhance the ultrahigh rate and ultralong life property of cathode, which can be used for large-scale commercial production in sodium ion batteries.

Fabrication of TiO2 coated porous CoMn2O4 submicrospheres for advanced lithium-ion anodes

Uniform CoMn₂O₄@TiO₂ porous nanospheres have been developed with excellent electrochemical performance when evaluated as anode materials for lithium ion batteries.

Enhancing Sodium Ion Battery Performance by Strongly Binding Nanostructured Sb2S3 on Sulfur-Doped Graphene Sheets

Sodium ion batteries (SIBs) have been considered a promising alternative to lithium ion batteries for large-scale energy storage. However, their inferior electrochemical performances, especially cyclability, become the major challenge for further development of SIBs. Large volume change and sluggish diffusion kinetics are generally considered to be responsible for the fast capacity degradation. Here we report the strong chemical bonding of nanostructured Sb₂S₃ on sulfur-doped graphene sheets (Sb₂S₃/SGS) that enables a stable capacity retention of 83% for 900 cycles with high capacities and excellent rate performances. To the best of our knowledge, the cycling performance of the Sb₂S₃/SGS composite is superior to those reported for any other Sb-based materials for SIBs. Computational calculations demonstrate that sulfur-doped graphene (SGS) has a stronger affinity for Sb₂S₃ and the discharge products than pure graphene, resulting in a robust composite architecture for outstanding cycling stability. Our study shows a feasible and effective way to solve the long-term cycling stability issue for SIBs.

Synthesis and Characterization of Self-Standing and Highly Flexible δ-MnO2@CNTs/CNTs Composite Films for Direct Use of Supercapacitor Electrodes

Self-standing and flexible films worked as pseudocapacitor electrodes have been fabricated via a simple vacuum-filtration procedure to stack δ-MnO2@carbon nanotubes (CNTs) composite layer and pure CNT layer one by one with CNT layers ended. The lightweight CNTs layers served as both current collector and supporter, while the MnO2@CNTs composite layers with birnessite-type MnO2 worked as active layer and made the main contribution to the capacitance. At a low discharge current of 0.2 A g(-1), the layered films displayed a high areal capacitance of 0.293 F cm(-2) with a mass of 1.97 mg cm(-2) (specific capacitance of 149 F g(-1)) and thickness of only 16.5 μm, and hence an volumetric capacitance of about 177.5 F cm(-3). Moreover, the films also exhibited a good rate capability (only about 15% fading for the capacitance when the discharge current increased to 5 A g(-1) from 0.2 A g(-1)), outstanding cycling stability (about 90% of the initial capacitance was remained after 5,000 cycles) and high flexibility (almost no performance change when bended to different angles). In addition, the capacitance of the films increased proportionally with the stacked layers and the geometry area. E.g., when the stacked layers were three times many with a mass of 6.18 mg cm(-2), the areal capacitance of the films was increased to 0.764 F cm(-2) at 0.5 A g(-1), indicating a high electronic conductivity. It is not overstated to say that the flexible and lightweight layered films emerged high potential for future practical applications as supercapacitor electrodes.

Effects of acute aerobic exercise on neural correlates of attention and inhibition in adolescents with bipolar disorder

Executive dysfunction is common during and between mood episodes in bipolar disorder (BD), causing social and functional impairment. This study investigated the effect of acute exercise on adolescents with BD and healthy control subjects (HC) to test for positive or negative consequences on neural response during an executive task. Fifty adolescents (mean age 16.54±1.47 years, 56% female, 30 with BD) completed an attention and response inhibition task before and after 20 min of recumbent cycling at ~70% of age-predicted maximum heart rate. 3 T functional magnetic resonance imaging data were analyzed in a whole brain voxel-wise analysis and as regions of interest (ROI), examining Go and NoGo response events. In the whole brain analysis of Go trials, exercise had larger effect in BD vs HC throughout ventral prefrontal cortex, amygdala and hippocampus; the profile of these effects was of greater disengagement after exercise. Pre-exercise ROI analysis confirmed this 'deficit in deactivation' for BDs in rostral ACC and found an activation deficit on NoGo errors in accumbens. Pre-exercise accumbens NoGo error activity correlated with depression symptoms and Go activity with mania symptoms; no correlations were present after exercise. Performance was matched to controls and results survived a series of covariate analyses. This study provides evidence that acute aerobic exercise transiently changes neural response during an executive task among adolescents with BD, and that pre-exercise relationships between symptoms and neural response are absent after exercise. Acute aerobic exercise constitutes a biological probe that may provide insights regarding pathophysiology and treatment of BD.

Skin image retrieval using Gabor wavelet texture feature

OBJECTIVE

Skin imaging plays a key role in many clinical studies. We have used many skin imaging techniques, including the recently developed capacitive contact skin imaging based on fingerprint sensors. The aim of this study was to develop an effective skin image retrieval technique using Gabor wavelet transform, which can be used on different types of skin images, but with a special focus on skin capacitive contact images.

METHODS

Content-based image retrieval (CBIR) is a useful technology to retrieve stored images from database by supplying query images. In a typical CBIR, images are retrieved based on colour, shape, texture, etc. In this study, texture feature is used for retrieving skin images, and Gabor wavelet transform is used for texture feature description and extraction.

RESULTS

The results show that the Gabor wavelet texture features can work efficiently on different types of skin images. Although Gabor wavelet transform is slower compared with other image retrieval techniques, such as principal component analysis (PCA) and grey-level co-occurrence matrix (GLCM), Gabor wavelet transform is the best for retrieving skin capacitive contact images and facial images with different orientations. Gabor wavelet transform can also work well on facial images with different expressions and skin cancer/disease images.

CONCLUSION

We have developed an effective skin image retrieval method based on Gabor wavelet transform, that it is useful for retrieving different types of images, namely digital colour face images, digital colour skin cancer and skin disease images, and particularly greyscale skin capacitive contact images. Gabor wavelet transform can also be potentially useful for face recognition (with different orientation and expressions) and skin cancer/disease diagnosis.

Voxel-Based Morphometry and fMRI Revealed Differences in Brain Gray Matter in Breastfed and Milk Formula-Fed Children

BACKGROUND AND PURPOSE

Infant diets may have significant impact on brain development in children. The aim of this study was to evaluate brain gray matter structure and function in 8-year-old children who were predominantly breastfed or fed cow's milk formula as infants.

MATERIALS AND METHODS

Forty-two healthy children (breastfed: n = 22, 10 boys and 12 girls; cow's milk formula: n = 20, 10 boys and 10 girls) were studied by using structural MR imaging (3D T1-weighted imaging) and blood oxygen level-dependent fMRI (while performing tasks involving visual perception and language functions). They were also administered standardized tests evaluating intelligence (Reynolds Intellectual Assessment Scales) and language skills (Clinical Evaluation of Language Fundamentals).

RESULTS

Total brain gray matter volume did not differ between the breastfed and cow's milk formula groups. However, breastfed children had significantly higher (P < .05, corrected) regional gray matter volume measured by voxel-based morphometry in the left inferior temporal lobe and left superior parietal lobe compared with cow's milk formula-fed children. Breastfed children showed significantly more brain activation in the right frontal and left/right temporal lobes on fMRI when processing the perception task and in the left temporal/occipital lobe when processing the visual language task than cow's milk formula-fed children. The imaging findings were associated with significantly better performance for breastfed than cow's milk formula-fed children on both tasks.

CONCLUSIONS

Our findings indicated greater regional gray matter development and better regional gray matter function in breastfed than cow's milk formula-fed children at 8 years of age and suggested that infant diets may have long-term influences on brain development in children.

Impaired white matter development in extremely low-birth-weight infants with previous brain hemorrhage

BACKGROUND AND PURPOSE

Brain hemorrhage is common in premature infants. The purpose of the study is to evaluate white matter development in extremely low-birth-weight infants with or without previous brain hemorrhage.

MATERIALS AND METHODS

Thirty-three extremely low-birth-weight infants were prospectively enrolled and included in this institutional review board-approved study. Another 10 healthy term infants were included as controls. The medical records of the extremely low-birth-weight infants were reviewed for sonography diagnosis of intraventricular hemorrhage. All infants had an MR imaging examination at term-equivalent age for detection of previous hemorrhage, and their white matter was scored and compared among different groups. DTI measured fractional anisotropy values were also compared voxelwise by tract-based spatial statistics.

RESULTS

Compared with controls, the white matter score was not significantly different in extremely low-birth-weight infants without blood deposition on MR imaging (P = .17), but was significantly worse in extremely low-birth-weight infants with blood deposition on MR imaging but no intraventricular hemorrhage diagnosis by sonography (P = .02), in extremely low-birth-weight infants with grade 1 or 2 intraventricular hemorrhage on sonography (P = .003), and in extremely low-birth-weight infants with grade 3 or 4 intraventricular hemorrhage on sonography (P = .0001). Extremely low-birth-weight infants without blood deposition on MR imaging did not show any white matter regions with significantly lower fractional anisotropy values than controls. Extremely low-birth-weight infants with blood deposition on MR imaging, but no intraventricular hemorrhage diagnosis, did show white matter regions with significantly lower fractional anisotropy values, and extremely low-birth-weight infants with intraventricular hemorrhage diagnosis had widespread white matter regions with lower fractional anisotropy values.

CONCLUSIONS

Previous brain hemorrhage is associated with abnormal white matter in extremely low-birth-weight infants at term-equivalent age, and sonography is not sensitive to minor hemorrhages that are sufficient to cause white matter injury.

Electrochemical properties of VPO4/C nanosheets and microspheres as anode materials for lithium-ion batteries

VPO4/C nanosheets and microspheres are successfully synthesized via a hydrothermal method followed by calcinations. The XRD results reveal that the obtained products both have an orthorhombic VPO4 phase. The SEM and TEM images demonstrate that nanosheets and spherical morphology can be obtained by controlling the synthesis conditions. The samples are both uniformly coated by amorphous carbon. The electrochemical test results show that the sample with a nanosheet structure has a better electrochemical performance than the microsphere samples. The VPO4/C nanosheets can deliver an initial discharge capacity of 788.7 mAh g(-1) at 0.05 C and possessed a favorable capacity at the rates of 1, 2, and 4 C. The nanosheet structure can effectively improve the electrochemical performances of VPO4/C anode materials.

Association of XRCC5 polymorphisms with COPD and COPD-related phenotypes in the Han Chinese population: a case-control cohort study

Genome-wide association studies (GWAS) and integrative genomic approaches have demonstrated significant associations between chronic obstructive pulmonary disease (COPD) and polymorphisms of the X-ray repair cross-complementing protein 5 gene (XRCC5) in non-Asian populations. We investigated whether XRCC5 polymorphisms might be associated with COPD susceptibility and COPD-related phenotypes in the Chinese Han population. Nine single nucleotide polymorphisms (SNPs) (rs3821104, rs12470053, rs207936, rs3770498, rs6704622, rs3770492, rs4674066, rs7573191, and rs207906) in the XRCC5 gene were genotyped in a case-control study including 680 COPD patients and 687 controls. To estimate the strength of association, odds ratios (ORs) were calculated and the effects of potentially confounding variables were tested by logistic regression analysis. The association between haplotypes and COPD outcome was also assessed. Our data identified that the SNP rs207936 was associated with COPD with an adjusted P value of 0.038, which was also found when analyzing only data of current smokers (P=0.046). No significant associations were found between any of the SNPs and pulmonary function. Eight SNPs (rs3821104, rs12470053, rs207936, rs3770498, rs6704622, rs3770492, rs4674066, and rs7573191) showed strong linkage disequilibrium (R2≥0.9). Two major haplotypes were observed and showed a significant difference between case and control groups (P=0.0054 and 0.0081, respectively). The present study showed that the XRCC5 locus might be a contributor to COPD susceptibility in the Chinese Han population.

Central and peripheral arterial stiffness in patients after surgical repair of tetralogy of Fallot: implications for aortic root dilatation

OBJECTIVES

To test the hypotheses that (1) the central conduit arteries stiffen preferentially over the peripheral conduit arteries in patients with repaired tetralogy of Fallot (ToF); and (2) central arterial stiffening is related to aortic root dilatation.

DESIGN AND PATIENTS

Heart-femoral pulse wave velocity (PWV), femoral-ankle PWV, carotid augmentation index and body surface area-adjusted aortic sinotubular dimension were determined in 31 children after ToF repair and compared with those in 31 age-matched controls after left-to-right shunt repair. In addition, the PWVs and augmentation index were related to the sinotubular junction dimension.

SETTINGS

Tertiary paediatric cardiac centre.

RESULTS

Compared with controls, patients had significantly greater heart-femoral PWV (mean 666 (SD 151) v 587 (81) cm/s, p = 0.021) and carotid augmentation index (-14.1 (17.0)% v -25.2 (14.6)%, p = 0.016), whereas the right (888 (202) v 845 (207) cm/s, p = 0.42) and left (918 (227) v 851 (215) cm/s, p = 0.25) femoral-ankle PWVs were similar between the two groups. The sinotubular junction z score of patients was significantly greater than that of controls (4.7 (1.5) v 1.1 (1.4), p < 0.001). Univariate analysis showed that the sinotubular junction z score correlated positively with heart-femoral PWV (r = 0.43, p = 0.001) and carotid augmentation index (r = 0.46, p = 0.001). Multiple linear regression similarly identified heart-femoral PWV (beta = 0.30, p = 0.04) and carotid augmentation index (beta = 0.31, p = 0.04) (model R(2) = 0.26) as significant determinants of sinotubular junction z score.

CONCLUSIONS

The aorta stiffens in patients with repaired ToF, which may contribute to progressive dilatation of the aortic root in the long term.

Hirudin ameliorates intestinal radiation toxicity in the rat: support for thrombin inhibition as strategy to minimize side-effects after radiation therapy and as countermeasure against radiation exposure

BACKGROUND

The small bowel is a dose-limiting normal tissue in radiation therapy of malignancies in the abdomen and pelvis, as well as an important determinant of survival after non-therapeutic radiation exposure. Irradiation of normal tissues, including intestine, causes loss of vascular thromboresistance and upregulation of thrombin receptors. Radiation-induced endothelial dysfunction is thought to be involved in both early and delayed radiation responses. Hence, thrombin may be a potential target for ameliorating normal tissue radiation toxicity.

OBJECTIVE

To assess direct thrombin inhibition as a protective strategy against small bowel radiation toxicity.

METHODS

Rat small intestine was exposed to localized orthovoltage X-radiation. Recombinant hirudin, a direct thrombin inhibitor, or vehicle was infused from 2 days before irradiation to 14 days after irradiation. Structural, cellular, and molecular aspects of intestinal radiation injury were assessed at 2 weeks (early toxicity) and 26 weeks (chronic toxicity) after irradiation.

RESULTS

Compared with unirradiated intestine, irradiated intestine showed increased expression of tissue factor, increased immunoreactivity for enzymatically active thrombin, and increased extravascular fibrin(ogen) deposition. Hirudin treatment significantly attenuated radiation-induced mucosal damage (P = 0.04), reactive intestinal wall thickening (P = 0.02), transforming growth factor-beta immunoreactivity levels (P = 0.0002), and collagen III deposition (P = 0.003). The differences between hirudin-treated and control rats were more pronounced at 2 weeks than at 26 weeks after irradiation. Hirudin treatment did not affect postradiation granulocyte infiltration.

CONCLUSIONS

Short-term thrombin inhibition attenuates important aspects of intestinal radiation toxicity. Thrombin is a promising target for minimizing normal tissue injury after radiation therapy of cancer, as well as for protecting normal tissues from the adverse effects of non-therapeutic radiation exposure.

[The binding characteristics of insulin-MTX to insulin receptor]

OBJECTIVE

It has been reported that several kinds of tumors express increased insulin receptor and the molecules of insulin can be internalized in cells and may thence enter into the nuclei mediated by insulin receptor. In this study, we investigated the receptor binding characteristics of insulin-MTX for the possibility of using insulin as a carrier for carcinoma targeted therapy by receptor mediation.

METHODS

MTX(methotrexate) was covalently linked to insulin directly. The insulin-MTX conjugate was purified by polyacrylamine agarose gel electrophoresis and analysed by high performance liquid chromatography and SDS- polyacrylamine agarose gel electrophoresis. Histologically confirmed human hepatocellular carcinoma specimens were obtained from patients at surgery and immediately frozen under -80 degrees C. Cell membrane fractions were isolated by sucrose density gradient centrifugation. Competitive displacement of 125I-insulin with insulin and insulin-MTX binding to insulin receptor were carried out and the values of IC50 and Ki were calculated so as to observe the characteristics of insulin-MTX binding to insulin receptor.

RESULTS

Insulin-MTX competed as effectively as insulin with 125I-insulin for insulin receptor. The values of IC50 and Ki for insulin-MTX were 93.82 +/- 19.32 nmol/L and 91.88 +/- 16.86 nmol/L respectively, while the values of IC50 and Ki for insulin were 5.01 +/- 1.24 nmol/L and 4.85 +/- 1.12 nmol/L respectively.

CONCLUSION

Insulin-MTX could bind with insulin receptor with high affinity. The result demonstrates us that there is a possibility of using insulin as a carrier for carcinoma targeted therapy by receptor mediation.

Cloning and characterization of the 5'-flanking region of the rat glutamate-cysteine ligase catalytic subunit

Glutamate-cysteine ligase (GCL), the rate-limiting enzyme in glutathione synthesis, is made up of two subunits, a catalytic (heavy) subunit (GCLC) and a modifier (light) subunit (GCLM), which are differentially regulated. Increased hepatic GCLC expression occurs during rapid growth, oxidative stress and after ethanol treatment. To facilitate studies of GCLC transcriptional regulation, we have cloned and characterized a 1.8 kb 5'-flanking region of the rat GCLC (GenBank accession number AF218362). A consensus TATA box and one transcriptional start site are located at 302 and 197 nucleotides upstream of the translational start site, respectively. The promoter contains consensus binding sites for many transcription factors including nuclear factor kappaB (NF-kappaB) and activator protein 1 (AP-1). The rat GCLC promoter was able to efficiently drive luciferase expression in H4IIE cells. Sequential deletion analysis revealed that three DNA regions, -595 to -111, -1108 to -705 and -705 to -595, are involved in positive (the first two regions) and negative (the latter region) gene regulation. Specific protein binding to these regions was confirmed by DNase I footprinting and electrophoretic mobility-shift assays (EMSAs). Ethanol-fed livers exhibit increased protein binding to region -416 to -336 on DNase I footprinting analysis, which was found to be NF-kappaB and AP-1 on EMSA and supershift analysis. Acetaldehyde treatment of H4IIE cells led to a time- and dose-dependent increase in GCLC mRNA levels, binding of NF-kappaB and AP-1 to the GCLC promoter, and luciferase activity driven by the GCLC promoter fragment containing these binding sites.

Cloning and analysis of the rat glutamate-cysteine ligase modifier subunit promoter

Glutamate-cysteine ligase (GCL), the rate-limiting enzyme in glutathione (GSH) synthesis, is made up of two subunits, a catalytic (GCLC) and a modifier (GCLM) subunit, which are differentially regulated. Increased GCLM expression occurs under certain oxidative stress conditions. To facilitate studies of GCLM transcriptional regulation, we have cloned and characterized a 1.86-kb 5'-flanking region of the rat GCLM (GenBank Accession No. AF311745). A TATA-like element and one transcriptional start sites are located at 364 and 93 nucleotides upstream of the translational start site, respectively. The promoter contains consensus binding sites for many transcription factors including activator protein 1 (AP-1), transcription factor 11 (TCF11), heat shock transcription factor (HSF), and nuclear factor kappa B (NFkappaB). The rat GCLM promoter was able to drive efficiently luciferase expression in H4IIE cells. Sequential deletion analysis revealed DNA regions, -649 to -154 and -1251 to -649, are involved in positive and negative gene regulation, respectively. Candidate transcription factors were identified by DNase I footprinting.

[Clinical study: the effects of inhaling nitrous oxide for analgesia labor on pregnant women and fetus]

OBJECTIVE

To investigate the effect of the inhalation of nitrous oxide premixed with oxygen (50%:50%) for analgesia labor on maternal and fetus.

METHODS

A total of 100 cases of pregnant women were provided with nitrous oxide premixed with oxygen (50%:50%) (control group); Another 100 cases were provided only with oxygen (comparison group). Recording duration of the Labor, way of delivery, bleeding volume, Apgars score, blood gas analysis to maternal radius artery and fetal umbilical blood among all patients.

RESULTS

The effect for analgesia labor of the premixed gas was much better than that of control group, but there were no significant differences in time of labor, bleeding volume, Apgars score between the two groups.

CONCLUSIONS

The inhalation of nitrous oxide premixed with oxygen (50%:50%) for analgesia labor benefits pregnant women because of keeping them being a good mental and physical condition. The inhalation of nitrous oxide for analgesia labor is a safe, effective and easy method.

Genetic analysis of vesicular stomatitis virus-New Jersey from the 1995 outbreak in the western United States

OBJECTIVE

To compare molecular associations between the vesicular stomatitis virus (VSV)-New Jersey isolates of the 1995 outbreak with those from previous outbreaks between 1982 and 1985 in the western United States.

SAMPLE POPULATION

23 virus isolates considered representative of the 1995 outbreak of vesicular stomatitis.

PROCEDURE

Viral gene coding for surface-envelope protein G was evaluated by use of nucleotide sequencing and phylogenetic analysis.

RESULTS

Changes in up to 0.77% of the nucleotide bases and 1.35% of the amino acids were detected among the 1995 viral isolates, whereas changes in up to 3.2 and 2.9% of the nucleotides and amino acids, respectively, were found, compared with the 1982 to 1985 viruses. Insertions or deletions were not found in the entire gene, which spanned 1,554 nucleotide bases.

CONCLUSIONS AND CLINICAL RELEVANCE

Phylogenetic analysis indicated that the 1995 VSV-New Jersey belongs to a lineage distinct from that of the 1982 to 1985 viruses that caused previous outbreaks in the western United States. Furthermore, it also is distinct from strains from Central America and from the Georgian Hazelhurst strain.

Regulation of the promoters for the human bone morphogenetic protein 2 and 4 genes

The bone morphogenetic proteins 2 and 4 are known to be important in bone formation and are expressed in both the developing and adult mammalian bone. Understanding the regulation of these genes in osteoblasts may yield methods by which we can control expression to induce bone formation. We have isolated and characterized the human BMP-2 and BMP-4 promoters and report substantially more upstream sequence information than that which has been published. Human osteoblasts were found to have a single transcript initiation site that is conserved across species, rather than multiple start sites, as has previously been reported (Feng, J.Q., Harris, M.A., Ghosh-Choudhury, N., Feng, M., Mundy, G.R., Harris, S.E., 1994. Structure and sequence of mouse morphogenetic protein-2 gene (BMP-2): comparison of the structures and promoter regions of BMP-2 and BMP-4 genes. Biochim. Biophys. Acta 1218, 221-224; Heller, L.C., Li, Y., Abrams, K.L., Rogers, M.B., 1999. Transcriptional regulation of the Bmp2 gene. J. Biol. Chem. 274, 1394-1400; Sugiura, T., 1999. Cloning and functional characterization of the 5'-flanking region of the human bone morphogenetic protein-2 gene. Biochem. J. 338, 433-440). A series of promoter deletions for both human BMP-2 and BMP-4 fused to the luciferase reporter gene were analyzed thoroughly in human and murine osteoblastic cell lines. Several compounds and growth factors that stimulate general or osteogenic pathways were used to treat cells transfected with the promoter constructs. Retinoic acid compounds and the phorbol ester, PMA were found to stimulate BMP-2 and, to a lesser degree, BMP-4. The combination of all trans-RA and PMA caused a synergistic increase in BMP-2 promoter activity and endogenous mRNA. The RA stimulation appears to be an indirect effect on the BMP-2 promoter, as the most highly conserved RRE in the BMP-2 promoter was unable to functionally bind or compete for protein binding. Potential binding sites in both promoters for the bone-specific transcription factor, Cbfa-1, were found to specifically bind Cbfa-1 protein in osteoblast nuclear extracts; however, deletion of these sites did not significantly affect transcriptional activity of the promoters in osteoblasts. These data thus present new sequence and regulatory information for the human BMP-2 and BMP-4 promoters and clarify the human BMP-2 gene transcriptional start site in osteoblasts.

[The use of insulin as carrier in targeted therapy]

Upon insulin binding to its receptor, the receptor-ligand complexes will be internalized into the target cell. The internalized insulin will leave the endosome and associate with the nuclear matrix. This process might be useful for targeted therapy. Some complex can link with the insulin be internalized into the target cell by insulin receptor-mediated endocytosis and enter the cell nuclei to cure some diseases.

[Determination of micro amounts of calcium and magnesium in saturated high purity sodium chloride solution by FAAS]

Micro amounts of calcium and magnesium in saturated high purity sodium chloride solution were determined by flame atomic absorption spectrometry after the preseparation of calcium and magnesium from matrix solution through ion-exchange resin column filled with model 401 chelate resin. The parameters and operating conditions of the preseparation of calcium and magnesium from matrix solution were studied by orthogonal optimization process. The relative standard deviations of this method were 6.5% and 5.5% for calcium and magnesium, respectively. The recoveries were 99% and 94% for calcium and magnesium, respectively.

Combined adenine phosphoribosyltransferase and N-acetylgalactosamine-6-sulfate sulfatase deficiency

We describe a Czech patient with combined adenine phosphoribosyltransferase (APRT) deficiency (2,8-dihydroxyadenine urolithiasis) and N-acetylgalactosamine-6-sulfate sulfatase (GALNS) deficiency (mucopolysaccharidosis Type IVA, Morquio disease A). Adenine and its extremely insoluble derivative, 2,8-dihydroxyadenine, were identified in the urine, and APRT deficiency was confirmed in erythrocytes. There was excessive excretion of keratan sulfate in the urine, and GALNS deficiency was confirmed in leukocytes. GALNS and APRT are both located on chromosome 16q24.3, suggesting that the patient had a deletion involving both genes. PCR amplification of genomic DNA indicated that a novel junction was created by the fusion of sequences distal to GALNS exon 2 and proximal to APRT exon 3, and that the size of the deleted region was approximately 100 kb. The deletion breakpoints were localized within GALNS intron 2 and APRT intron 2. Several other genes, including the alpha subunit of cytochrome B (CYBA), which is deleted or mutated in the autosomal form of chronic granulomatous disease, are located in the 16q24.3 region, but PCR amplification showed that this gene was present in the proband. A patient with hemizygosity for GALNS deficiency and APRT deficiency has been reported from Japan recently. These findings indicate that: (i) APRT is located telomeric to GALNS; (ii) GALNS and APRT are transcribed in the same orientation (centromeric to telomeric); and (iii) combined APRT/GALNS deficiency may be more common than hitherto realized.

Activity of dolastatin 10 against small-cell lung cancer in vitro and in vivo: induction of apoptosis and bcl-2 modification

PURPOSE

Dolastatin 10 is a natural cytotoxic peptide which acts through the inhibition of microtubule assembly. Studies have suggested that such agents can induce apoptosis in association with bcl-2 phosphorylation. Since bcl-2 overexpression is common in small-cell lung cancer (SCLC), we evaluated the activity of dolastatin 10 in SCLC cell lines and xenografts.

METHODS

In vitro growth inhibition was evaluated with a standardized MTT assay and apoptosis with fluorescent microscopy and a TUNEL assay. Immunoblot analysis and phosphatase digestion were used to determine bcl-2 modification. In vivo activity was evaluated in subcutaneous and metastatic SCLC xenograft models in SCID mice.

RESULTS

Dolastatin 10 had growth inhibitory activity against four SCLC cell lines (NCI-H69, -H82, -H446, -H510) with IC50 values ranging from 0.032 to 0.184 nM. All four cell lines exhibited evidence of apoptosis after 48 h of exposure to 1.3 nM dolastatin 10. Immunoblot analysis revealed that 1.3 nM dolastatin 10 altered the electrophoretic mobility of bcl-2 in NCI-H69 and -H510 cells within 16 h of treatment. Incubation of protein extract from dolastatin 10-treated NCI-H69 and -H510 cells with calcineurin resulted in the disappearance of the altered mobility species, suggesting dolastatin 10-induced bcl-2 phosphorylation. In in vivo studies, 450 microg/kg of dolastatin 10 IV x 2 given after intravenous injection of NCI-H446 cells completely inhibited tumor formation. In established subcutaneous NCI-H446 xenografts, 450 microg/kg of dolastatin 10 IV induced apoptosis in the majority of tumor cells within 96 h, resulting in a log10 cell kill of 5.2 and an increase in median survival from 42 to 91 days.

CONCLUSIONS

These findings suggest that dolastatin 10 has potent activity against SCLC and that the modulation of apoptotic pathways deserves further evaluation as an anticancer strategy.

Identification and functional characterization of the murine Rac2 gene promoter

Rac2, a member of the Rho family of GTPases, is highly expressed in myeloid cells and is a regulator of the NADPH-oxidase complex. A murine genomic clone was isolated that contains the 5' end and putative promoter region of the Rac2 gene. Ribonuclease protection experiments detected 13 transcription initiation sites scattered 50 to 130 bp upstream of the translation initiation site. Transient transfection studies revealed that -7 kb to +31 bp (relative to the strongest transcription initiation site) of the Rac2 gene 5'-flanking region exhibited strong promoter activity in both RAW 264.7 macrophage cells that express the endogenous Rac2 gene and NIH-3T3 fibroblast cells that do not express the endogenous gene. Truncated Rac2 promoter fragments containing as little as the -74 to +31 bp sequence produced full transcriptional activity. However, a -57 to +31 promoter fragment directed significantly less transcription, and a -39 to +31 promoter fragment was transcriptionally inactive. In vitro binding assays revealed sequence-specific and widely expressed DNA-binding activities that interacted within the -74 to -58 Rac2 promoter cis element. Oligonucleotide competition and antibody disruption studies indicated that these complexes contained the transcription factors Spl and Sp3. Specific ablation of the Sp1/Sp3 binding site significantly decreased Rac2 promoter activity in both RAW 264.7 and NIH-3T3 cells. Additional cis elements may be required to restrict Rac2 promoter activity to hematopoietic cells expressing the endogenous gene.

Activity of fenretinide plus chemotherapeutic agents in small-cell lung cancer cell lines

PURPOSE

Fenretinide [N-(4-hydroxyphenyl)retinamide, 4HPR], a synthetic retinoid, is a potent inducer of apoptosis in small-cell lung cancer (SCLC) cell lines that may act through the generation of reactive oxygen species, suggesting that it may enhance the activity of other cytotoxic agents. In light of 4HPR's clinical potential and potent activity against SCLC cells, we evaluated the in vitro activity of 4HPR in combination with cisplatin, etoposide or paclitaxel.

METHODS

The growth-inhibitory activities of single-agent 4HPR, cisplatin, etoposide or paclitaxel, and combinations of 4HPR and individual chemotherapeutic agents, were evaluated using an MTT assay in two SCLC cell lines. Each two-drug combination was studied over a range of concentrations at a fixed ratio corresponding to the ratio of the IC5 values of the individual agents. Data were analyzed by median-effect analysis as previously applied to drug combination studies.

RESULTS

All four agents inhibited growth in a dose-dependent manner in the NCI-H82 and NCI-H446 SCLC cell lines. At clinically reported drug concentrations that resulted in over 50% growth inhibition, the activities of the combinations 4HPR and cisplatin and 4HPR and etoposide were more than additive in both cell lines, and the activity of 4HPR plus paclitaxel was more than additive in NCI-H446 cells.

CONCLUSION

4HPR's potent single-agent activity, minimal toxicity, and potential synergy with standard cytotoxic drugs will allow for the development of promising investigational regimens for the treatment of patients with SCLC.

Activity of 9-cis-retinoic acid and receptor-selective retinoids in small cell lung cancer cell lines

Dysregulation of retinoid signaling pathways appears to be an early event in the pathogenesis of small cell lung cancer (SCLC). We evaluated the activity of 9-cis-retinoic acid (9cRA), a pan- receptor agonist, and two synthetic retinoids, TTNPB and LG100153, which are RAR- and RXR- selective, respectively, against a panel of SCLC cell lines. LG100153 was the most potent agent with an IC50 < 1.0 microM in three cell lines. TTNPB had an IC50 < 1.0 microM in two lines, and 9cRA an IC50 < 1.0 microM in only one. By fluorescent microscopy, LG100153, TTNPB and 9cRA also induced morphologic evidence of apoptosis in three, two and one cell lines, respectively. Although the expression of RARs and RXRs varied widely between cell lines, there was no clear correlation between the level or pattern of receptor expression and retinoid activity. These data suggest that novel retinoids, especially RXR-selective agents, deserve further evaluation in the treatment of SCLC.

One face of a transmembrane helix is crucial in mechanosensitive channel gating

MscL is a mechanosensitive channel in bacteria that responds directly to membrane tension by opening a large conductance pore. To determine functionally important residues within this molecule, we have randomly mutagenized mscL, expressed the genes in living bacteria, and screened for gain-of-function mutants with hampered growth. Expression of these genes caused leakage of cytoplasmic solutes on little or no hypo-osmotic stress. In excised patches, the mutant channels gated at membrane tensions that are less than that required for the gating of the wild-type MscL. Hence, the data suggest that the slowed or no-growth phenotype is caused by solute loss because of inappropriate gating of the channel. Most of the mutations mapped to the first transmembrane domain. When this domain is modeled as an alpha-helix, the most severe mutations are substitutions of smaller amino acids (three glycines and one valine) on one facet, suggesting an important role for this structure in MS channel gating.

Exaggerated astrocyte reactivity after nigrostriatal deafferentation in the aged rat

Although clinical experience suggests that brain injury in the aged is associated with a poor prognosis, little research has examined this phenomenon at a cellular or molecular level. Unilateral 6-hydroxydopamine lesions of the nigrostriatal system were produced in 6-, 15- or 24-month-old rats. In the deafferented neostriatum, the time-dependent induction of glial fibrillary acidic protein (GFAP) was larger and persisted longer in the aged rats. The response of middle-aged rats was intermediate. In contrast, no induction of S-100 or glutamine synthetase was observed in any age group. In a second series of rats with stab wounds in the neostriatum, there were substantially larger GFAP inductions than after deafferentation, but fewer effects of age. However, in both lesion paradigms, GFAP staining increased in the contralateral striatum of old rats, but not in young rats. These data support and extend our earlier work describing larger GFAP RNA inductions after fornix transections in aged mouse hippocampus. The consistency of this exaggerated glial reactivity in the aged brain after modest injury suggests the following: 1) aged astrocytes are more sensitive to gliotrophic factors released by terminal degeneration, 2) larger quantities of such factors are produced after injury, 3) clearance of these factors is delayed in old rodents, and/or 4) aged astrocytes are less able to terminate GFAP inductions after activation. Given the potential role of inflammatory reactions as pathogenic mechanisms in Alzheimer's dementia, these data suggest that age-related glial hypersensitivity may independently increase the risk for some degenerative diseases.

Age-related change in short-term synaptic plasticity intrinsic to excitatory striatal synapses

Aging disrupts the expression of synaptic plasticity in many central nervous system (CNS) structures including the striatum. We found age differences in paired-pulse plasticity to persist at excitatory striatal synapses following block of gamma aminobutyric acid (GABA)A and GABA(B) receptors, a property that was independent of the number of afferents activated. High Mg2+/low Ca2+ artificial cerebral spinal fluid (ACSF) reduced release probability and consequently the size of the evoked excitatory post-synaptic potential (EPSP). High Mg2+/low Ca2+ ACSF also increased the expression of paired-pulse facilitation and eliminated the age difference seen previously in normal ACSF. These data suggest that age differences in paired-pulse plasticity reflect an alteration in release probability at excitatory striatal synapses. In support of this hypothesis, we found age differences in another presynaptic form of plasticity referred to as synaptic augmentation. Examination of the synaptic depression that developed during the conditioning tetanus also revealed an age-related increase in synaptic depression. These data indicate that age-related changes in facilitation may be due in part to a reduction in the readily releasable pool of synaptic vesicles. Dendritic structure (spine density and dendritic length) was correlated with short-term synaptic plasticity, but these relationships depended upon the variance associated with age (hierarchical regression). Post-hoc within-age group regressions demonstrated relationship between spine density and paired-pulse plasticity. No other age-specific correlations were found. These findings imply an age-dependent association between altered dendritic morphology and changes in synaptic plasticity.

[Correction of occipito-posterior position by maternal posture during the process of labor]

OBJECTIVE

To investigate the effect on correction of occipito-posterior (OP) presentation by changing maternal posture during labor.

METHOD

A prospective study was conducted in 120 pregnant women from March 1994 to December 1995. Women in labor were instructed to take the lateral posture so that the resultant force of the gravity of the fetus, the buoyancy of amniotic fluid, and the intermittent uterine contraction may change the fetal position from occipito-posterior into occipito-anterior (OA) presentation. Another 120 women were selected as controls.

RESULTS

(1) In the study group, 106 women (88.3%) delivered vaginally with fetal presentation changed from OP into OA, and 14 (11.7%) received cesarean section. In the control group, only 20 women (16.7%) delivered vaginally, and 100 (83.3%) had cesarean sections (P < 0.001). (2) The average time interval in the study group was 302.6 min for the first stage and 59.8 min for the second stage, whereas 483.7 min and 156.1 min respectively in the controls. A significant difference was noted (P < 0.01).

CONCLUSION

It is an effective method for the mother to take the lateral posture on the same side of the fetal spine for correcting the OP position. The incidence of dystocia may be reduced as well as the cesarean section rate. The method in simple and effective, and can be used in most of hospitals.