Photoluminescence of ZnO nanocrystals embedded in BaF2 matrices by magnetron sputtering

This paper describes ZnO nanocrystals embedded in BaF2 matrices by the magnetron sputtering method in an attempt to use fluoride as a shell layer to embed ZnO nanocrystals core. BaF2 is a wide-band gap material, and can confine carriers in the ZnO films. As a result, the exciton emission intensity should be enhanced. The sample was annealed at 773 K, and X-ray diffraction (XRD) results showed that ZnO nanocrystals with wurtzite structure were embedded in BaF2 matrices. Raman-scattering spectra also confirmed the formation of ZnO nanoparticles. Abnormal longitudinal-optical (LO) phonon-dominant multiphonon Raman scattering was observed in the sample. Room-temperature photoluminescence (PL) spectra showed an ultraviolet emission peak at 374 nm. The origin of the ultraviolet emission is discussed here with the help of temperature-dependent PL spectra. The ultraviolet emission band was a mixture of free exciton and bound exciton recombination observed in the low temperature PL spectra (at 77 K). Abnormal temperature dependence of ultraviolet near-band-edge emission-integrated intensity of the sample was observed. The band tail state was observed in the absorption spectra, illustrating that the impurity-related defects were caused by the shell of the BaF2 grain layer. For comparison, ZnO films on BaF2 substrates were also fabricated by the magnetron sputtering method, and the same measurement methods were used.

The host species affects the microbial community in the goat rumen

AIMS

This study was carried out to determine whether bacterial and ciliate populations in goat rumen vary significantly between different goat species living in the same environment.

METHODS AND RESULTS

Bacterial and ciliate communities in the rumen of three goat species were analysed at the molecular level using denaturing gradient gel electrophoresis. The microbial community varied considerably among goats living in the same environment. Interspecies variation in the bacterial population was noticeably greater than intraspecies variation. In contrast, there was considerable variation in the ciliate population among goats within the same species, and intraspecies similarities were no greater than those observed across species.

CONCLUSIONS

Because environmental factors and diets were identical for all goats, differences in bacterial populations reflect species-specific differences in rumen microbes.

SIGNIFICANCE AND IMPACT OF THE STUDY

Factors related to the host species have an important effect on determining the bacterial composition in the goat rumen.

Identification and characterization of a MBP isoform specific to hypothalamus in orange-spotted grouper (Epinephelus coioides)

Myelin basic protein (MBP), as a major component of the myelin sheath, has been revealed to play an important role in forming and maintaining myelin structure in vertebrate nervous system. In teleost, hypothalamus is an instinctive brain center and plays significant roles in many physiological functions, such as energy metabolism, growth, reproduction, and stress response. In comparison with other MBP identified in vertebrates, a smallest MBP is cloned and identified from the orange-spotted grouper hypothalamic cDNA plasmid library in this study. RT-PCR analysis and Western blot detection indicate that the EcMBP is specific to hypothalamus, and expresses mainly in the tuberal hypothalamus in adult grouper. Immunofluorescence localization suggests that EcMBP should be expressed by oligodendrocytes, and the expressing cells should be concentrated in hypothalamus and the area surrounding hypothalamus, such as NPOpc, VC, DP, NLTm, and NDLI. The studies on EcMBP expression pattern and developmental behaviour in the brains of grouper embryos and larvae reveal that the EcMBP-expressing cells are only limited in a defined set of cells on the border of hypothalamus, and suggest that the EcMBP-expressing cells might be a subpopulation of oligodendrocyte progenitor cells. This study not only identifies a smallest MBP isoform specific to hypothalamus that can be used as a molecular marker of oligodendrocytes in fish, but also provides new insights for MBP evolution and cellular distribution.

The effect of chymotrypsin on the determination of total alpha-glucosidase activity in seminal plasma and the correlation between alpha-glucosidase level and semen parameters

To evaluate the effect of chymotrypsin on the examination of alpha-glucosidase activity in seminal plasma, thirty-nine samples of fresh liquefied semen with or without chymotrypsin and forty-eight samples of fresh un-liquefied semen with chymotrypsin were determined for the total alpha-glucosidase activity in seminal plasma. The total alpha-glucosidase level of each sample was assayed by the method of glucose oxidase. The correlations between alpha-glucosidase level and semen parameters, including semen volume, pH, sperm concentration, grade a and b motility and total motility, were analyzed with SPSS 11.0 software. The results showed that chymotrypsin had no effect on seminal alpha-glucosidase activity determination. Chymotrypsin could improve the liquefaction for un-liquefied semen, and there was no significant difference of alpha-glucosidase activity between liquefied and un-liquefied semen samples. There were significantly positive correlations between seminal alpha-glucosidase activity (U/ml) and sperm concentration (r = 0.338, p = 0.015) and between total alpha-glucosidase activity (U/ejaculate) and semen volume (r = 0.677, p = 0.000). However, there was no significant correlation between alpha-glucosidase level (U/ml) and semen volume, pH, sperm motility or grade a and b motility (r = -0.234 approximately 0.077, p = 0.099 approximately 0.993). The data indicated that chymotrypsin could be added into the un-liquefied semen samples for alpha-glucosidase activity determination, and there were different correlations between seminal alpha-glucosidase level and various semen parameters.

Introduction of a disulfide bridge enhances the thermostability of a Streptomyces olivaceoviridis xylanase mutant

Substitution of the N-terminus of Streptomyces olivaceoviridis xylanase XYNB to generate mutant TB has been previously shown to increase the thermostability of the enzyme. To further improve the stability of this mutant, we introduced a disulfide bridge (C109-C153) into the TB mutant, generating TS. To assess the effect of the disulfide bridge in the wild-type enzyme, the S109C-N153C mutation was also introduced into XYNB, resulting in XS. The mutants were expressed in Pichia pastoris, the recombinant enzymes were purified, and the effect of temperature and pH on enzymatic activity was characterized. Introduction of the disulfide bridge (C109-C153) into XYNB (XS variant) and TB (TS variant) increased the thermostability up to 2.8-fold and 12.4-fold, respectively, relative to XYNB, after incubation at 70 degrees C, pH 6.0, for 20 min. In addition, a synergistic effect of the disulfide bridge and the N-terminus replacement was observed, which extended the half-life of XYNB from 3 to 150 min. Moreover, XS and TS displayed better resistance to acidic conditions compared with the respective enzymes that did not contain a disulfide bridge.

A genetic algorithm design for microcalcification detection and classification in digital mammograms

In this paper, we propose a genetic algorithm design to automatically classify and detect micocalcification clusters in digital mammograms. The proposed GA technique is characterised by transforming input images into a feature domain, where each pixel is represented by its mean and standard deviation inside a surrounding window of size 9 x 9 pixel. In the feature domain, chromosomes are constructed to populate the initial generation and further features are extracted to enable the proposed GA to search for optimised classification and detection of microcalcification clusters via regions of 128 x 128 pixels. Extensive experiments show that the proposed GA design is able to achieve high performances in microcalcification classification and detection, which are measured by ROC curves, sensitivity against specificity, areas under ROC curves and benchmarked by existing representative techniques.

Differential effects of Th1, monocyte/macrophage and Th2 cytokine mixtures on early gene expression for immune-related molecules by central nervous system mixed glial cell cultures

Cytokines secreted within the central nervous system (CNS) are important in the development of multiple sclerosis (MS) lesions. The balance between Th1, monocyte/macrophage (M/M) and Th2 cytokines in the CNS may be pivotal in determining the outcome of lesion development. We examined the effects of mixtures of cytokines on gene expression by CNS glial cells, as mixtures of cytokines are present in MS lesions, which in turn contain mixtures of glial cells. In this initial analysis by gene array, we examined changes at 6 hours to identify early changes in gene expression that represent primary responses to the cytokines. Rat glial cells were incubated with mixtures of Th1, M/M and Th2 cytokines for 6 hours and examined for changes in early gene expression employing microarray gene chip technology. A minimum of 814 genes were differentially regulated by one or more of the cytokine mixtures in comparison to controls, including changes in expression in a large number of genes for immune system-related proteins. Expression of the proteins for these genes likely influences development and inhibition of MS lesions as well as protective and regenerative processes. Analysing gene expression for the effects of various combinations of exogenous cytokines on glial cells in the absence of the confounding effects of inflammatory cells themselves should increase our understanding of cytokine-induced pathways in the CNS.

A randomized open-label study of darbepoetin alfa administered every 3 weeks with or without parenteral iron in anemic subjects with nonmyeloid malignancies receiving chemotherapy

8612

Background: Patients (pts) with cancer receiving chemotherapy often have chemotherapy-induced anemia (CIA) and reduced quality of life. Darbepoetin alfa (DA) is an erythropoiesis-stimulating agent (ESA) that can effectively treat CIA when administered once every 3 weeks (Q3W). In patients with CIA, limited data in the literature suggest that administration of intravenous (IV) iron with ESA therapy may increase clinical response. Methods: This randomized, multicenter, open-label, 16-week study evaluated the safety and efficacy of DA 500 mcg administered Q3W using the SureClick injection device in pts with CIA (Hb < 11 g/dL) who received either IV iron or standard practice for iron administration (oral iron or no iron). The dose of IV iron was 200 mcg administered either Q3W with DA Q3W or, if required, as 2 doses (200 mcg total) within a 3-week period. Pts who received ≥ 1 dose of DA and who completed the 16-week study period by October 19, 2005 are included in this interim analysis (planned sample size = 400 pts). Accrual will have finished by conference time. Randomization was stratified by tumor type and baseline (BL) Hb (< 10 or ≥ 10 g/dL). The incidence of adverse events and serious adverse events, in particular embolic/thrombotic events, was summarized. Efficacy endpoints were estimated using the crude % of pts (95% CI). Hb values within 28 days of a transfusion were not included in any efficacy analysis. Results: Of the 114 pts included in this interim analysis, 65% were women, 99% were Caucasian, the mean (SD) age was 60 years (12), and 26% had lung or gynecological tumors; study endpoints are shown in the table. Conclusions: Based on the interim results, the safety profile for pts receiving DA 500 mcg Q3W with IV iron appears to be comparable to pts receiving DA 500 mcg Q3W with oral iron or no iron. The % pts who achieved the target Hb (≥ 11 g/dL) appeared higher, and the % pts who required transfusions appeared lower, in the group receiving IV iron.

[Table: see text]

[Table: see text]

Combination of MIG (CXCL9) chemokine gene therapy with low-dose cisplatin improves therapeutic efficacy against murine carcinoma

MIG (monokine induced by interferon-gamma) is a CXC chemokine ligand (CXCL9) that can potently inhibit angiogenesis, and displays thymus-dependent antitumor effects. The effectiveness of a treatment combining gene therapy with plasmid-borne MIG (pORF-MIG) and low-dose cisplatin chemotherapy was determined using colon carcinoma (CT26) and Lewis lung carcinoma (LL/2c) murine models. The program was carried out via intramuscular delivery of pORF-MIG at 100 mug/mouse twice a week for 4 weeks, and/or intraperitoneal delivery of cisplatin at 0.6 mg/kg/mouse every 3 days for 48 days. Tumor volume and survival time were evaluated after treatment. CD31 immunohistochemical staining in tumor tissues and alginate capsule models in vivo was used to evaluate angiogenesis. Induction of apoptosis and cytotoxic T-lymphocyte (CTL) activity were also assessed. The combination of pORF-MIG and low-dose cisplatin produced significant antitumor activity, with complete tumor regression in 4/10 of CT26 colon carcinomas and 3/10 of LL/2c lung carcinomas, low vascularity, in alginate capsules, apparently degraded tumor microvessel density, and increased induction of apoptotic and CTL activities compared with either treatment alone. This study suggests that the combination of pORF-MIG plus cisplatin augments the inhibition of angiogenesis and the induction of apoptosis or CTL activity, all of which enhance antitumor activity. These findings may prove useful in further explorations of the application of combinatorial approaches to the treatment of solid tumors.

Linear correlation between fractal dimension of EEG signal and handgrip force

Fractal dimension (FD) has been proved useful in quantifying the complexity of dynamical signals in biology and medicine. In this study, we measured FDs of human electroencephalographic (EEG) signals at different levels of handgrip forces. EEG signals were recorded from five major motor-related cortical areas in eight normal healthy subjects. FDs were calculated using three different methods. The three physiological periods of handgrip (command preparation, movement and holding periods) were analyzed and compared. The results showed that FDs of the EEG signals during the movement and holding periods increased linearly with handgrip force, whereas FD during the preparation period had no correlation with force. The results also demonstrated that one method (Katz's) gave greater changes in FD, and thus, had more power in capturing the dynamic changes in the signal. The linear increase of FD, together with results from other EEG and neuroimaging studies, suggest that under normal conditions the brain recruits motor neurons at a linear progress when increasing the force.

LARALink: a web application for cytogenetic linkage analysis

Genomic and expression data have increased dramatically over the last several years. This is primarily due to the completion of the human genome project as well as an upsurge in the use of various high-throughput technologies. Recent attempts to correlate genomic and expression data have stimulated the scientific community to determine how this data can be used within a clinical setting (P Khatri et al., Genomics 2002: 79: 266; LJ van't Veer et al., Nature 2002: 415: 530). LARALink (Loci Analysis for Rearrangements Link) is a database-driven web application that utilizes several public datasets to analyze clinical cytogenetic data to identify candidate genes. LARALink allows UniGene clusters or single-nucleotide polymorphisms (SNPs) to be queried for multiple patients by cytoband, chromosome marker, or base pair. The results can be further refined with the use of an anatomical site, developmental stage, pathology, or cell-type expression filter. Once a set of UniGene clusters (expressed genes) has been identified either for a single patient or for a shared region among multiple patients, the expression-distribution profile, expressed sequence tags (ESTs), or online mendelian inheritance in man (OMIM) entries are displayed. The utility of this tool is shown by its application to both research and clinical medicine. LARALink is a public resource available at: http://www.laralink.bioinformatics.wayne.edu:8080/unigene.

[Urogenital tuberculosis: diagnostic difficulties in 5 cases]

OBJECTIVES

The aim of this study is: to emphasize the difficulties of diagnosing genito-urinary tuberculosis because of its non specific symptoms; to incite the physician to seek it more frequently.

MATERIAL AND METHOD

Five cases of genito-urinary tuberculosis have been diagnosed within a 10-years period and included in a retrospective study.

RESULTS

We found one location in the kidney and one location in the bladder with 2 women diagnosed by repeated urianalysis and 3 cases of location in epididymis diagnosed after surgery.

CONCLUSION

Symptoms of genito-urinary tuberculosis are misleading, pathologic findings are taking a more and more important place in the diagnosis, which the new techniques of serologic tests will surely improve.

[Heavy hematuria with shock caused by bladder pheochromocytoma]

The authors report a case of pheochromocytoma of the bladder revealed by an important gross hematuria with shock. The diagnosis has been established by the pathologist after a partial cystectomy. This location mimmicks a bladder tumor. The diagnosis is difficult; conservative surgery is the rule.

[Treatment of vesicovaginal fistulas using the musculofascial flap of the levator ani muscle: 26 case reports]

OBJECTIVE

The authors reported the preliminary results of levator ani muscle flap in the treatment of vesicovaginal fistula.

MATERIALS AND METHODS

Twenty-six patients whose age varied between 13 and 18 years (mean: 30 years) are selected. All the patients are treated by the vaginal approach using the part of superficial rectal fibers of the levator ani muscle.

RESULTS

Among the 26 patients, 14 are free after the first cure of vesicovaginal fistula (54%), and 4 patients (15%), after the treatment of some complications.

CONCLUSION

The musculofascial levator ani flap with its vascular pedicle and its mobilisation can successfully close the vesicovaginal fistula. The preliminary results obtained (88%) tie up with that previously described in the literature.