High-sensitivity photovoltaic responses in manganite-based heterojunctions on Si substrates for weak light detection

We have fabricated and characterized a weak light photodetector in a heterojunction composed of manganite La0.4Ca0.6MnO3 and n-type Si. High-sensitivity photoresponse properties were investigated. The responsivities of open-circuit photovoltage and short-circuit photocurrent reach ∼1000  V/mJ and ∼30  A/mJ, respectively, without any amplification bias under irradiation by 20-ps-wide and 355, 532, and 1064-nm-wavelength laser pulses in nanojoule to microjoule order. The present results demonstrate that the manganite-based heterojunction on Si substrate has potential applications in weak light detection from ultraviolet to near-infrared light.

Analysis of the bacterial community changes in soil for septic tank effluent treatment in response to bio-clogging

Soil columns were set up to survey the bacterial community in the soil for septic tank effluent treatment. When bio-clogging occurred in the soil columns, the effluent from the columns was in poorer quality. To evaluate changes of the soil bacterial community in response to bio-clogging, the bacterial community was characterized by DNA gene sequences from soil samples after polymerase chain reaction coupled with denaturing gradient gel electrophoresis process. Correspondence analysis showed that Proteobacteria related bacteria were the main bacteria within the soil when treating septic tank effluent. However, Betaproteobacteria related bacteria were the dominant microorganisms in the normal soil, whereas Alphaproteobacteria related bacteria were more abundant in the clogged soil. This study provided insight into changes of the soil bacterial community in response to bio-clogging. The results can supply some useful information for the design and management of soil infiltration systems.

Effects of tripeptides and lactogenic hormones on oligopeptide transporter 2 in bovine mammary gland

This study was conducted to investigate the expression of oligopeptide transporter 2 (PepT2) and its potential function in bovine mammary gland. First, the PepT2 mRNA and protein were determined in cultured mammary epithelial cells. Then the effects of lactogenic hormones (prolactin, hydrocortisone or insulin) and substrate (threonyl-phenylalanyl-phenylalanine) on PepT2 were investigated. The PepT2 mRNA and protein were successfully detected in bovine mammary epithelial cells. PepT2 gene expression was enhanced by the addition of 50, 500 and 5000 ng/ml prolactin, 10 and 100 ng/ml hydrocortisone, and 50, 500, 5000 and 50,000 ng/ml insulin. PepT2 mRNA abundance was increased when 5, 10 and 15% of threonyl-phenylalanyl-phenylalanine was included. Responses of PepT2 to lactogenic hormones and oligopeptide inferred that it may play an important role in bovine mammary gland.

Superconductivity above 33 K in (Ca(₁ - x)Na(x))Fe₂As₂

We report the synthesis of (Ca₀.₃₃Na₀.₆₆)Fe₂As₂ showing a superconducting transition with T(c) above 33 K. Both dc magnetic susceptibility or specific heat measurements indicated the bulk superconductivity nature of the sample. We also have successfully grown single crystals of the (Ca₀.₃₃Na₀.₆₆)Fe₂As₂ superconductors. The single crystals exhibit sharp superconducting transitions with T(c) above 33 K. The effects of magnetic field on the superconducting transitions are studied, giving rise to high upper critical fields with H(c₂)(c)≈85 T and H(c₂)(ab)≈172 T, respectively. The anisotropy parameter was calculated to be around 2.

A dynamic method for in vitro multisegment spine testing

Robotics recently spread to spine biomechanical research. The aim of the present work is to describe and validate a new method for in vitro studying of a multisegmental spinal specimen under dynamic conditions. This method relies on the use of a simulator with six degrees of freedom (to impose movements in all directions), an optoelectric apparatus (for collecting kinematics data) and an original system for attaching kinematic markers, allowing their precise removal and replacement under different examination conditions. The accuracy of measurements as well as their reproducibility under static and dynamic conditions is reported here in the study of a human lumbar spinal specimen (L1-sacrum). The method appears to be reliable and reproducible, and should therefore enable future studies of variations in mobility between healthy and pathological spines, to better understand the influence of different implants on spinal kinematics.

Involved-field radiotherapy for patients with limited small cell lung cancer: Patterns of local-regional failure and feasibility

7554

Background: To investigate the feasibility of the involved-field radiotherapy in patients with limited-stage small cell lung cancer (LSCLC) according to the patterns of local failure, focused on the first local-regional failure. Methods: Two clinical phase II studies for patients with LSCLC treated at our institute between 1997 and 2007 were reviewed. All patients received combined chemotherapy (CHT) with cisplatin and etoposide, and thoracic RT (TRT) was generally delivered sequentially following one to three cycles of CHT and consisted of either 56 Gy in 40 fractions for 4 weeks or 55 Gy in 22 fractions for 4–5 weeks. TRT fields encompassed primary tumor volume (post-CHT) and the involved nodal areas (pre- and post-CHT) without elective node irradiation. The local-regional failure was defined as failure within thoracic cavity and supraclavicular fossa except for pleural effusion, which was then divided into two subtypes: in-field and out-field failure according to the first occurred site in the planning target volume or not. Results: There were 89 patients completed the planed regimen and eligible for evaluating patterns of failure, 54 patients (57%) in 56 Gy cohort and 35 patients(43%) in 55 Gy cohort. The media cycles of CHT were 6 (4–8). The overall survival and local progression-free survival rates for 89 patients at 2 years were 56% and 71%, respectively, with a median survival of 25.6 months. 56 patients (63%) developed distant metastases and 21 patients (24%) developed local-regional failures: 12 in-field and 9 out-field. 8 out of 9 out-field failures occurred in the ipsilateral supraclavicular fossa, and the media duration to the end of TRT was 6 mouths (5–14). Comparing the 56 Gy and 55 Gy cohorts, the rates of any thoracic, in-field and out-field failures were no difference significantly. Conclusions: Thoracic radiotherapy using involved-field technique in patients with LSCLC resulted in a high failure rate of the supraclavicular fossa. Whether improving accuracy for the initial evaluation of clinical stage could reduce out-field failure in supraclavicular fossa need to be investigated.

No significant financial relationships to disclose.

Corneal nerves alterations in various types of systemic polyneuropathy, identified by in vivo confocal microscopy

BACKGROUND

In vivo confocal microscopy (IVCM) is a newly developed application to assess corneal nerve morphology. The purpose of the study is to evaluate the role of IVCM in the assessment of various types of polyneuropathy, and to define alterations of corneal nerves in such conditions.

PATIENTS AND METHODS

Eighteen patients with various types of polyneuropathy were characterized by clinical neurological and ophthalmic examinations, as well as by electroneuromyography (ENMG). Full thickness IVCM of corneal nerves was carried out on all patients and 15 age-matched eyes using Heidelberg Retina Tomograph II (HRT II). The subbasal nerve plexus were statistically analysed regarding long nerve fiber density, nerve branch density, nerve thickness, nerve bead number and nerve tortuosity.

RESULTS

In subbasal nerve plexus, the following three parameters were significantly reduced in patients with polyneuropathy compared to controls: long nerve fibre density (p < 0.01), nerve branch density (p < 0.001), and nerve bead number (p = 0.001). In addition, the average grade of nerve tortuosity was 2.87 +/- 0.97 in the polyneuropathic group and 1.17 +/- 0.68 in the control group (p < 0.0001).

CONCLUSIONS

IVCM allows a non-invasive, in vivo study of corneal nerves with high resolution. It therefore appears invaluable in clinical investigations. IVCM appears to be valuable in a large variety of polyneuropathic conditions.

Visible-blind, ultraviolet-sensitive photodetector based on SrTiO3 single crystal

High-sensitivity and visible-blind ultraviolet (UV) photoconductive detectors based on SrTiO(3) single crystal with interdigitated electrodes are reported. The responsivities of photovoltage and photocurrent can reach 2.13x10(5) V/W and 213 mA/W, respectively, at 330 nm at ambient temperature, and the corresponding quantum efficiency eta reaches 80.2%. The dark current is lower than 50 pA at 10 V bias, and the UV/visible contrast ratio is about four orders of magnitude with a sharp cutoff at 390 nm. The experimental results demonstrate that SrTiO(3) single crystal has potentially wide applications in UV detection.

Virtual screening for finding natural inhibitor against cathepsin-L for SARS therapy

Recently Simmons et al. reported a new mechanism for SARS virus entry into target cells, where MDL28170 was identified as an efficient inhibitor of CTSL-meditated substrate cleavage with IC₅₀ of 2.5 nmol/l. Based on the molecule fingerprint searching method, 11 natural molecules were found in the Traditional Chinese Medicines Database (TCMD). Molecular simulation indicates that the MOL376 (a compound derived from a Chinese medicine herb with the therapeutic efficacy on the human body such as relieving cough, removing the phlegm, and relieving asthma) has not only the highest binding energy with the receptor but also the good match in geometric conformation. It was observed through docking studies that the van der Waals interactions made substantial contributions to the affinity, and that the receptor active pocket was too large for MDL21870 but more suitable for MOL736. Accordingly, MOL736 might possibly become a promising lead compound for CTSL inhibition for SARS therapy.

An electric bottle for colloids

Particle concentration is a dominant control parameter for colloids and other soft matter systems. We demonstrate a simple technique, "dielectrophoretic equilibrium," implemented as an "electric bottle," a planar capacitor in a larger volume. The uniform field in the capacitor traps particles in this force-free region at a higher density than in the zero field regions outside. We show how the technique measures the equation of state and we initiate and grow colloidal crystals. "Dielectrophoretic equilibria" enable the study of a complete concentration-dependent phase diagram from a single microscopic sample, obviating the previous need for preparing a large number of samples.

Molecular evolution and intragenic recombination of the merozoite surface protein MSP-3alpha from the malaria parasite Plasmodium vivax in Thailand

The merozoite surface antigens of malaria parasites are prime anti-morbidity/mortality vaccine candidates. However, their highly polymorphic nature requires extensive surveys of parasite populations to validate vaccine designs. Previous studies have found 3 molecular types (A, B and C) of the Plasmodium vivax merozoite surface protein 3a (PvMSP-3alpha) among parasite field populations. Here we analysed complete PvMSP-3alpha sequences from 17 clinical P. vivax isolates from Thailand and found that the nucleotide diversity was as high as that from samples widely separated by time and space. The polymorphic sites were not randomly distributed but concentrated in the N-terminal Ala-rich domain (block 2A), which is partially deleted in type B and C sequences. The size variations among type A sequences were due to small indels occurring in block 2A, whereas type B and C sequences were uniform in length with each type having a different large deletion. Analysis of synonymous and non-synonymous substitutions suggested that different selection forces were operating on different regions of the molecule. The numerous recombination sites detected within the Ala-rich domain suggested that intragenic recombination was at least partially responsible for the observed genetic diversity of the PvMSP-3alpha gene. Phylogenetic analysis failed to link any alleles to a specific geographical origin, even when different domains of PvMSP-3alpha were used for analysis. The highly polymorphic nature and lack of geographical clustering of isolates suggest that more systematic investigations of the PvMSP-3alpha gene are needed to explore its evolution and vaccine potential.

Static and fatigue mechanical behavior of bone cement with elevated barium sulfate content for treatment of vertebral compression fractures

The use of bone cement to treat vertebral compression fractures in a percutaneous manner requires placement of the cement under fluoroscopic image guidance. To enhance visualization of the flow during injection and to monitor and prevent leakage beyond the confines of the vertebral body, the orthopedic community has described increasing the amount of radiopacifier in the bone cement. In this study, static tensile and compressive testing, as well as fully reversed fatigue testing, was performed on three PMMA-based bone cements. Cements tested were SimplexP with 10% barium sulfate (Stryker Orthopedics, Mahwah, NJ) which served as a control; SimplexP with 36% barium sulfate prepared according to the clinical recommendation of Theodorou et al.; and KyphX HV-R with 30% barium sulfate (Kyphon Inc., Sunnyvale, CA). Static tensile and compressive testing was performed in accordance with ASTM F451-99a. Fatigue testing was conducted in accordance with ASTM F2118-01a under fully reversed, +/-10-, +/-15-, and +/-20-MPa stress ranges. Survival analysis was performed using three-parameter Weibull modeling techniques. KyphX HV-R was found to have comparable static mechanical properties and significantly greater fatigue life than either of the two control materials evaluated in the present study. The static tensile and compressive strengths for all three PMMA-based bone cements were found to be an order of magnitude greater than the expected stress levels within a treated vertebral body. The static and fatigue testing data collected in this study indicate that bone cement can be designed with barium sulfate levels sufficiently high to permit fluoroscopic visualization while retaining the overall mechanical profile of a conventional bone cement under typical in vivo loading conditions.

Characterization of genotype II Rubella virus strains

Two genotypes of Rubella virus have been described that differ by 8-9% at the nucleotide level in the E1 glycoprotein gene. Of these, genotype II (RGII) was only recently reported and in this study two RGII viruses, the BRDII vaccine strain and BR1 wild type strain, were characterized. Monoclonal antibodies against each of the virion proteins (capsid [C], glycoproteins E1 and E2) and polyclonal anti-rubella virus sera reacted similarly with purified virions from the RGII and reference RGI strains on Western gels, with the exception of one anti-E2 Mab, and thus the two genotypes are closely related antigenically. The genomic sequences of two genotype II (RGII) rubella virus strains were determined and compared with the six previously reported RGI sequences. The genomes of these viruses all contained 9762 nts and the lengths of the three untranslated regions (UTRs) and two open reading frames (ORF's) were identical. The overall difference between the RGI and RGII sequences at the nt level was approximately 8% and this difference was maintained across most of the genome. At the amino acid level, the RGI and RGII sequences differed overall by approximately 4%, however this difference was not uniform across the ORF's as the N-terminal third of P150 and the entirety of P90, both replicase proteins, were more conserved (<1% difference) while the C-terminal two thirds of P150 exhibited greater variation ( approximately 8% difference), including a hypervariable region between residues 771-801 within which divergence as great as 20-30% was detected. The parent wt virus of the BRDII vaccine was not available and its sequence was compared with the BR1 sequence to identify potential attenuating mutations. The BRDII and BR1 sequences varied at 252 residues (2.59%), including twelve in the UTRs and thirty coding differences in the ORF's. None of these differences in the BRDII sequence was vaccine-specific when compared with RGI wt and vaccine sequences and, therefore, there appeared to be no common pathway in the generation of live, attenuated rubella vaccines.

Hyperfine polarization and its normal gradient coefficient of (87)Rb atoms in the vicinity (approximately 10(-5) cm) of coated and uncoated Pyrex glass surfaces

We have made regionally specific measurement of the hyperfine polarization <S.I> of 87Rb atoms in the vicinity ( approximately 10(-5) cm) of coated and uncoated Pyrex glass surfaces. We find that the polarization near an uncoated surface decreases rapidly with decreasing distance from the surface whereas for a silicone-coated surface the polarization is independent of the distance from the surface. We have also determined the normal gradient coefficient micro (S.I) of the hyperfine polarization in uncoated cells. In a representative uncoated cell, at a Rb density 7.35 x 10(13) cm(-3) and a pump beam intensity 1.3 W/cm(2), we find micro(S.I)=24+/-7 microm(-1).

Establishment of a highly efficient transformation system for pepper (Capsicum annuum L.)

Application of modern genetic manipulation has been limited in pepper ( Capsicum annuum L.) due to the lack of an efficient transformation system. Following the development of an efficient protocol for in vitro regeneration of pepper cotyledons, we investigated the key factors affecting transformation and established a highly efficient genetic transformation system using the pepper cotyledon as starting material. In this system, cotyledon explants are preconditioned for 2 days on kanamycin (km)-free DM1 medium [Murashige and Skoog (MS) salts/Gamborg B5 vitamins basal medium supplemented with 20 g/l sucrose, 5,000 mg/l DJ nutrients and a hormone combination of 1.0 mg/l indoleacetic acid (IAA) and 5.0 mg/l 6-benzyladenine (BA) solidified with 0.7% agar, pH 5.8], followed by co-cultivation with Agrobacterium tumefaciens on DM1 for 2 days and delay selection on DM1 with 500 mg/l carbenicillin (carb) for 2 days. The explants are then placed on DM1 containing 10 mg/l AgNO(3), 50 mg/l km-sulfate and 500 mg/l carb. After 4-5 weeks, the explants with buds are transferred to EM1 medium (MS salts/Gamborg B5 vitamins basal medium supplemented with 20 g/l sucrose, 5,000 mg/l DJ nutrients, 10 mg/l AgNO(3) and a hormone combination of 1.0 mg/l IAA, 3.0 mg/l BA and 2.0 mg/l gibberellic acid, solidified with 0.7% agar, pH 5.8) with 50 mg/l kanamycin and 500 mg/l carbenicillin for the elongation of buds. After 3-6 weeks, 1- to 2-cm-long elongated shoots are excised and planted on RM1 medium (MS basal medium supplemented with a hormone combination of 0.2 mg/l NAA and 0.1 mg/l IAA, solidified with 0.8% agar, pH 5.8) with 25 mg/l km and 200 mg/l carb for rooting. We tested four genotypes of pepper, and all presented a high differentiation efficiency (81.3% on average), elongation rate (61.5%) and rooting efficiency (89.5%). Polymerase chain reaction analysis results showed that 40.8% of the regenerated plantlets were transgenic plants.

Effect of lipase treatment on the biocompatibility of microbial polyhydroxyalkanoates

Films made from microbial polyesters polyhydroxybutyrate (PHB) and poly(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx) were treated by lipases and NaOH solution. The change of the polyester biocompatibility was evaluated by inoculating mouse fibroblast cell line L929 on films of PHB, PHBHHx and their blends. Polylactic acid (PLA) was used as a control. It was found that untreated PHB and PLA films gave a poor support to the growth of L929 cells, viable cell density ranged from 0.1x10(4}) to 0.7x10(4) per ml only. While films of pure PHBHHx and PHB blended with PHBHHx showed improved biocompatibility, viable cell density observed increased from 9.6x10(2) to 6x10(4) on blended films of PHB/PHBHHx in ratios of 0.9/0.1 to 0/1, respectively. This result showed PHBHHx has a better biocompatibility compared with PHB. Films of PHB, PLA and the blends treated with lipases and 1 N NaOH, respectively, showed an improved ability to support cell growth. Biocompatibility of PHB was approximately the same as PLA after the treatment, while PHBHHx and its dominant blends showed improved biocompatibility compared with PLA. The sensitivity of the treatments was reduced when PHBHHx content increased in the PHB/PHBHHx blends. All three lipase treatments demonstrated more biocompatibility increase on all the films compared with the results of NaOH treatment. Scanning electron microscopy showed that PHB films changed its surface from multi-porous to rough non-porous after the lipase or NaOH treatment. While PHBHHx films showed little change after these treatments. The results showed that the polyester surface morphology played an important role in affecting cell attachment and growth on these materials.

Rossby vortex simulation on a paraboloidal coordinate system using the lattice Boltzmann method

In this paper, we apply our compressible lattice Boltzmann model to a rotating parabolic coordinate system to simulate Rossby vortices emerging in a layer of shallow water flowing zonally in a rotating paraboloidal vessel. By introducing a scaling factor, nonuniform curvilinear mesh can be mapped to a flat uniform mesh and then normal lattice Boltzmann method works. Since the mass per unit area on the two-dimensional (2D) surface varies with the thickness of the water layer, the 2D flow seems to be "compressible" and our compressible model is applied. Simulation solutions meet with the experimental observations qualitatively. Based on this research, quantitative solutions and many natural phenomena simulations in planetary atmospheres, oceans, and magnetized plasma, such as the famous Jovian Giant Red Spot, the Galactic Spiral-vortex, the Gulf Stream, and the Kuroshio Current, etc., can be expected.

Novel deletion of the RPGR gene in a Chinese family with X-linked retinitis pigmentosa

PURPOSE

To characterize a Chinese family with inherited retinitis pigmentosa (RP).

METHODS

Linkage studies and haplotype analysis were used for gene mapping, and single-strand conformation polymorphism (SSCP) analysis and direct DNA sequence analysis were used for identifying the responsible mutation.

RESULTS

Pedigree analysis suggests that RP in the Chinese family RP002 is inherited either as an autosomal recessive trait or as an X-linked trait. Linkage analysis of RP002 excluded all known autosomal recessive RP loci. Further analysis with 17 polymorphic markers covering the entire X chromosome localized the RP gene in RP002 between markers GATA175D03 and GATA144D04 on Xp11.4, a region where the RP3 gene (RPGR ) is found. Mutation analysis of the RPGR gene in RP002 revealed a novel 28-bp deletion in exon 7. This deletion resulted in an in-frame stop codon that eliminates the C-terminal two-thirds of the RPGR protein. The 28-bp deletion co-segregated with the disease in the family and was not present in 100 normal Chinese individuals. Female carriers of the deletion were affected with myopia and had ERG abnormalities and mild constriction of visual field.

CONCLUSIONS

A novel 28-bp deletion in the RPGR gene identified in an X-linked Chinese RP family causes severe RP in male patients as well as myopia and ERG abnormalities in female carriers. The deletion represents the largest microdeletion identified in RPGR to date, and expands the spectrum of RPGR mutations causing XLRP.

[Treatment of congenital jerky nystagmus with opposite bidirectional neutral zone]

OBJECTIVE

To explore a method for the treatment of congenital jerky nystagmus with opposite bidirectional neutral zones.

METHOD

The relatively used side between the two neutral zone was found by neutralizing bilateral head torsion angle with prisms. The surgical intervention was indicated for those patients whose head position would not turn to another side.

RESULT

There were 14 cases treated by this method, none of these cases whose head position turned to another side. Ten cases underwent once operation, 2 cases, twice operations and another 2 cases undertook once operation with additional prism correction. The compensatory head posture was corrected and the vision in the primary position of gaze was improved in all the cases.

CONCLUSION

This therapy for congenital jerky nystagmus with opposite bidirectional neutral zone shows significant therapeutic effects and can be available for clinical application.

Novel rhodopsin mutation in a Chinese family with autosomal dominant retinitis pigmentosa

PURPOSE

To identify mutations in the rhodopsin (RHO) gene in Chinese patients with autosomal dominant retinitis pigmentosa (ADRP) and to measure the prevalence rate of RHO mutations in Chinese ADRP cases.

METHODS

Thirteen Chinese families with ADRP were clinically characterized. The complete coding region and intron splice sites of RHO were analyzed for mutations with single-strand conformation polymorphism (SSCP) analysis and direct genomic sequencing.

RESULTS

One of the 13 Chinese families with ADRP was found to have a new, previously unidentified RHO mutation, a change from GAG to TAG at codon 341. The mutation (E341X) results in an in-frame stop codon, leading to the truncation of the rhodopsin protein. Mutation E341X was not detected in 100 normal control individuals. Patients carrying mutation E341X reported night blindness and showed optic atrophy, vessel attenuation, and a few bone spicule-like pigments in peripheral retina at the age of 23-25 years. At the age of 30 years, visual acuity was severely impaired, peripheral visual field was greatly constricted, rod and cone ERG was not detectable, and only a slight left cone response remained.

CONCLUSIONS

We have identified a novel rhodopsin mutation (E341X) in a Chinese family with ADRP. The location and character of the mutation expand the spectrum of RHO mutations causing RP. Identification of a RHO mutation in one of the 13 ADRP families studied suggests that only 7.7% of the ADRP cases in a Chinese population were caused by RHO mutations, a ratio significantly lower than that from North America or Europe.

[A clinical investigation into the effect of comfort denture adhesive on masticatory function with complete dentures]

OBJECTIVE

The purpose of this study was to evaluate the clinical effect of the new developed form of Comfort denture adhesive (Comfort DA).

METHODS

10 edentulous patients with complete dentures were selected for this study. The maximum biting force and masticatory efficiency were recorded before and after application of the adhesive to all the new and old dentures. Subjective test was also used to evaluate this adhesive in enhancing retention and stability of complete denture using the questionnaire way.

RESULTS

The data indicated that significantly greater biting forces were generated with old dentures than with the new dentures. The major findings were that the adhesive produced a statistically significant improvement in the masticatory efficiency after application. Subjective views of the patients indicated that this tested product significantly improved denture retention, stability and had other favorable features. The time of adhesion was about 6 8 hours.

CONCLUSION

The generally favorable clinical performance of the developed Comfort DA formulation indicated that it might be an efficacious denture adhesive.

Update on the molecular genetics of retinitis pigmentosa

Retinitis pigmentosa (RP) is a heterogeneous group of retinal dystrophies characterized by photoreceptor cell degeneration. RP causes night blindness, a gradual loss of peripheral visual fields, and eventual loss of central vision. Advances in molecular genetics have provided new insights into the genes responsible and the pathogenic mechanisms of RP. The genetics of RP is complex, and the disease can be inherited in autosomal dominant, recessive, X-linked, or digenic modes. Twenty-six causative genes have been identified or cloned for RP, and an additional fourteen genes have been mapped, but not yet identified. Eight autosomal dominant forms are due to mutations in RHO on chromosome 3q21-24, RDS on 6p21.1-cen, RP1 on 8p11-21, RGR on 10q23, ROM1 on 11q13, NRL on 14q11.1-11.2, CRX on 19q13.3, and PRKCG on 19q13.4. Autosomal recessive genes include RPE65 on chromosome 1p31, ABCA4 on 1p21-13, CRB1 on 1q31-32.1, USH2A on 1q41, MERTK on 2q14.1, SAG on 2q37.1, RHO on 3q21-24, PDE6B on 4p16.3, CNGA1 on 4p14-q13, PDE6A on 5q31.2-34, TULP1 on 6p21.3, RGR on 10q, NR2E3 on 15q23, and RLBP1 on 15q26. For X-linked RP, two genes, RP2 and RP3 (RPGR), have been cloned. Moreover, heterozygous mutations in ROM1 on 11q13, in combination with heterozygous mutations in RDS on 6p21.1-cen, cause digenic RP (the two-locus mechanism). These exciting molecular discoveries have defined the genetic pathways underlying the pathogenesis of retinitis pigmentosa, and have raised the hope of genetic testing for RP and the development of new avenues for therapy.

Regulation of CSF1 promoter by the SWI/SNF-like BAF complex

The mammalian BAF complex regulates gene expression by modifying chromatin structure. In this report, we identify 80 genes activated and 2 genes repressed by the BAF complex in SW-13 cells. We find that prior binding of NFI/CTF to the NFI/CTF binding site in CSF1 promoter is required for the recruitment of the BAF complex and the BAF-dependent activation of the promoter. Furthermore, the activation of the CSF1 promoter requires Z-DNA-forming sequences that are converted to Z-DNA structure upon activation by the BAF complex. The BAF complex facilitates Z-DNA formation in a nucleosomal template in vitro. We propose a model in which the BAF complex promotes Z-DNA formation which, in turn, stabilizes the open chromatin structure at the CSF1 promoter.

Image labeling: a graphical interface to correlation in multiparticle ejection dynamics

A novel graphical approach for probing multicomponent collective ejection processes is described. Image labeling provides a visual means for identifying ejection partners and their relative momenta, isolating specific decay channels for detailed study and determining initial electronic and/or molecular geometries prior to ejection. The power of the technique is demonstrated by looking at strong-field multiphoton-induce 3-atom Coulomb explosion spectra.

Effect of menthone on the in vitro percutaneous absorption of tamoxifen and skin reversibility

The effect of penetration enhancer (i.e., 1, 2, 3 and 5% menthone in combination with 50% ethanol (EtOH)) was investigated on the in vitro percutaneous absorption of tamoxifen, and post-recovery epidermal permeability after removal of the above enhancer. The flux of tamoxifen with menthone in combination with 50% EtOH was significantly greater (P<0.05) than the control (50% EtOH). The flux of tamoxifen increased with increasing concentrations of menthone. The post-recovery flux through enhancer exposed epidermis was significantly decreased (P<0.05) as compared to pre-recovery. However, post-recovery flux of tamoxifen through the enhancer-exposed epidermis did not completely recover to the baseline (i.e., post-recovery flux through phosphate buffered saline, pH 7.4 treated epidermis).

MECP2 truncating mutations cause histone H4 hyperacetylation in Rett syndrome

Rett syndrome (RTT) is a mostly sporadic disorder of developmental regression, with loss of speech and purposeful hand use, microcephaly and seizures. It affects 1 in 10 000-15 000 females. RTT is caused by mutations in the MECP2 gene, which is located in Xq28 and subject to X inactivation. MECP2 encodes a methyl-CpG-binding protein that binds to 5-methyl-cytosine in DNA through its methyl-binding domain. Recruitment of a transcriptional silencing complex through MeCP2's transcriptional repression domain results in histone deacetylation and chromatin condensation. To study the effects of two common truncating RTT mutations (R168X and 803delG), we examined mutant MeCP2 expression and global histone acetylation levels in clonal cell cultures from a female RTT patient with the mutant R168X allele on the active X chromosome, as well as in cells from a male hemizygous for the frameshift mutation 803delG (V288X). Both mutant alleles generated stable RNA transcripts, but no intact MeCP2 protein was detected with an antibody against the C-terminal region of MeCP2. Western blots with antibodies against acetylated histones H3 and H4 revealed that H4, but not H3, was hyperacetylated. By using antibodies against individual acetylated lysine residues, the observed H4 hyperacetylation was attributed to increased acetylation of lysine 16. Therefore, expression of endogenous truncating MECP2 alleles, in the absence of wild-type MeCP2 protein, is specifically associated with an increase in the mono-acetylated histone isoform H4K16. This observed effect may result in over-expression of MeCP2 target genes and, thus, play a role in the pathogenesis of RTT.

Crystal structure of the mouse p53 core DNA-binding domain at 2.7 A resolution

The p53 tumor suppressor is a sequence-specific DNA-binding protein that activates transcription in response to DNA damage to promote cell cycle arrest or apoptosis. The p53 protein functions in a tetrameric form in vivo and contains four domains including an N-terminal transcriptional activation domain, a C-terminal regulatory domain, a tetramerization domain, and a central core DNA-binding domain that is the site of the majority of tumor-derived mutations. Here we report the 2.7-A crystal structure of the mouse p53 core domain. Like the human p53 core domain in complex with DNA, the mouse p53 core domain adopts an immunoglobulin-like beta sandwich architecture with a series of loops and short helices at opposite ends of the beta sandwich. Comparison of the DNA-bound and DNA-free p53 core domains reveals that while the central beta sandwich architecture remains largely unchanged, a loop region important for DNA binding undergoes significant rearrangement. Although this loop region mediates major groove DNA contacts in the DNA-bound structure, it adopts a conformation that is incompatible with DNA binding in the DNA-free structure. Interestingly, crystals of the DNA-free core domain contain a noncrystallographic trimer with three nearly identical subunit-subunit (dimer) contacts. These dimer contacts align the p53 core domains in a way that is incompatible with simultaneous DNA binding by both protomers of the dimer. Surprisingly, similar dimer contacts are observed in crystals of the human p53 core domain with DNA in which only one of the three p53 protomers in the asymmetric unit cell is specifically bound to DNA. We propose that the p53 core domain dimer that is seen in the crystals described here represents a physiologically relevant inactive form of p53 that must undergo structural rearrangement for sequence-specific DNA binding.

Food-derived heterocyclic amine mutagens: variable metabolism and significance to humans

The cooking of meat has been found to generate compounds that possess extreme mutagenicity when examined in short term tests. This observation led to the isolation and identification of a family of mutagenic chemicals, all of which are heterocyclic amines. These amines are potent bacterial and eukaryotic cell mutagens, and all of those tested have been found to induce tumors in laboratory animals. Metabolic activation of the heterocyclic amines predominantly involves CYP1-mediated N-hydroxylation and then O-esterification by phase II enzymes. In contrast, carbon oxidation, glucuronidation, and sulfation reactions at sites other than the hydroxylamine yield detoxication metabolites. In humans, the activities of these pathways are known to vary between individuals and are likely to influence susceptibility to the genetic toxicity of the heterocyclic amines. Clearly, accurate determination of human exposure to the heterocyclic amines and identification of the key enzyme systems involved and their regulation will be required for rational assessment of the risk and will help devise strategies to reduce such risk.

Development of an occupational illness and injury surveillance database for the electric energy sector

Currently available occupational injury and illness data for electric energy companies provide only overall summary rates. Specific information about types of injury or illnesses, rates by occupational or work environments, and injury costs and severity are generally not readily available. Relevant data such as personnel and claims information are frequently not integrated into a comprehensive health and safety surveillance system suitable for epidemiologic and health and safety research purposes. Epidemiological methods are valuable for identifying key risk factors for work-related injuries and illnesses and assessing their magnitude, as well establishing priorities for health and safety research. Application of such methods can result in long-term reductions in injury and illness rates and their attendant costs. Aggregation of relevant health and safety data across companies improves statistical power for the assessment of rare (yet costly) injuries or illness or specific at-risk subgroups within the electric energy sector. A pilot occupational injury and illness database has been developed that can incorporate and standardize data across a spectrum of companies of differing sizes and configurations. In illustrative data analyses, injury trends were summarized by company size, occupation, and demographic factors, among others. Trends observed in these illustrative analyses were consistent with results previously reported in the epidemiological literature, however, results are considered preliminary pending development of the full database. This study shows that development of a standardized surveillance occupational injury and illness database across companies with different database configurations is feasible. This database will ultimately provide a stable and accurate occupational health and safety assessment tool not currently available for this sector.

[Recent advance in studies of new intraaortic axial flow pump: "dynamic aortic valve"]

We have previously proposed and demonstrated the feasibility of a new concept of intraaortic axial flow blood pump, termed "Dynamic Aortic Valve(DAV)". Implanted in the position of aortic valve, DAV can serve as either an assistant pump or a mechanical valve subjected to the power input. It has several merits over the traditional axial blood pumps: (1) better anatomic compatibility and biologic compatibility; (2) little foreign material is to be introduced into the corporeality; (3) better resistance to infection; (4) puncturing power line could be eliminated; (5) promoting the failing heart to recovery; (6) simpler structure and better durability. In our recent studies, the structure of DAV is further simplified and performance improved greatly. The structure of DAV is merely an impeller fixed to a magnetic rotor while held by a central shaft hanging from a rigid supporting cage. The rotor-impeller can be driven by an alternative magnetic field derived from a remote magnet, implying that the magnetic source can even be arranged extracorporeally. The DAV can be driven by a rotational magnet placed at a distance of 60 mm. At the state of maximal output of hydraulic power, the flow rate (FR) generated by DAV reaches 5 L/min against an afterload of 70 mmHg(1 mmHg = 0.133 KPa). The maximal pressure differential (PD) maintained by DAV is 131 mmHg. The results further revealed the feasibility of the concept of DAV.

In vitro cytotoxicity evaluation of denture adhesive

OBJECTIVE

The ideal denture adhesive demonstrates a minimal toxicity to the mucosa. The purpose of this study was to evaluate the in vitro cytotoxicity of a new denture adhesive.

MATERIAL AND METHODS

Samples were prepared and extracted in Dulbecco's Modified Eagle's Medium. The cell viability of human oral fibroblast cells cultivated for 24 hours with DA-containing medium was evaluated by the MTT assay to investigate cell proliferation. Optical densities were measured by a spectrophotometer at 490 nm.

RESULTS

The statistical analysis of results showed that this denture adhesive displayed only slight cytotoxicity.

CONCLUSION

The generally favorable in vitro cytotoxicity of the denture adhesive formulation indicates that this product may be efficacious.

The gastrointestinal tract: a major site of antioxidant action?

Diets rich in fruits and vegetables delay the onset of many age-related diseases, and contain a complex mixture of antioxidants (including ascorbate, carotenoids, vitamin E and other phenolics such as the flavonoids). However, diet also contains pro-oxidants, including iron, copper, H2O2, haem, lipid peroxides and aldehydes. Nitrite is frequently present in diet, leading to generation of reactive nitrogen species in the stomach. In considering the biological importance of dietary antioxidants, attention has usually focussed on those that are absorbed through the gastrointestinal tract into the rest of the body. In the present paper we develop the argument that the high levels of antioxidants present in certain foods (fruits, vegetables, grains) and beverages (e.g. green tea) play an important role in protecting the gastrointestinal tract itself from oxidative damage, and in delaying the development of stomach, colon and rectal cancer. Indeed, carotenoids and flavonoids do not seem to be as well absorbed as vitamins C and E. Hence their concentrations can be much higher in the lumen of the GI tract than are ever achieved in plasma or other body tissues, making an antioxidant action in the GI tract more likely. Additional protective mechanisms of these dietary constituents (e.g. effects on intercellular communication, apoptosis, cyclooxygenases and telomerase) may also be important.

CeReS-18, a cell regulatory sialoglycopeptide, inhibits proliferation and migration of rat vascular smooth muscle cells

CeReS-18, a cell regulatory sialoglycopeptide, has been shown to inhibit proliferation of a wide array of target cells. In the present study, the effect of CeReS-18 on vascular smooth muscle cell (SMC) proliferation was characterized in cultured rat aorta SMCs (A7r5). More extensively, the effect of CeReS-18 on platelet-derived growth factor (PDGF)-induced SMC migration was examined using a modified Boyden's chamber assay. CeReS-18 inhibits both SMC proliferation and migration in a concentration-dependent, calcium-sensitive, and reversible manner. Furthermore, cells preincubated with the inhibitor had an increased sensitivity to CeReS-18-mediated inhibition of SMC migration. Immunoprecipitation and in vitro phosphorylation assays demonstrated that MAP kinase activity was inhibited in the CeReS-18-treated cells and pretreatment with CeReS-18 suppressed the activation of MAP kinase stimulated by PDGF. However, it is not likely that the suppression of the MAP kinase pathway was directly responsible for the ability of CeReS-18 to inhibit migration of the rat aorta smooth muscle cells since a MEK-specific inhibitor, PD98059, did not influence A7r5 cell migration.

DNA strand break and 8-hydroxyguanine formation induced by 2-hydroxyestradiol dispersed in liposomes

DNA damage induced by estrogens dispersed in liposomes was investigated. 2-Hydroxyestradiol (2HOE(2)) and 4-hydroxyestradiol (4HOE(2)), but not estrone, estradiol-17beta or estriol, caused strand break of plasmid DNA damage in the presence of ADP-Fe(3+). The catechol structure may be necessary for DNA damage. When DNA was incubated with 2HOE(2) for a long time (24 h), DNA damage was induced even at very low concentrations. Adding hydrogen peroxide markedly enhanced the sensitivity of DNA to the attack by 2HOE(2). Hydroxyl radical (HO.) scavengers strongly inhibited the 2HOE(2)-induced DNA damage, and EDTA partially inhibited DNA damage. However, 2HOE(2) caused 8-hydroxyguanine formation from calf thymus DNA only in the presence of EDTA-Fe(3+), but not ADP-Fe(3+). In addition, deoxyribose, which is a detective molecule of HO(.), was not degraded by 2HOE(2) in the presence of ADP-Fe(3+). Upon adding EDTA 2HOE(2) rapidly degraded deoxyribose. These results suggest that DNA strand break caused by 2HOE(2) in the presence of ADP-Fe(3+) was due to ferryl ion rather than HO(.), whereas 8-hydroxyguanine (8HOG) induced by 2HOE(2) in the presence of EDTA-Fe(3+) was due to HO(.).

[Long-term follow-up results of microsurgical treatment for glossopharyngeal neuralgia]

OBJECTIVE

To discuss effective surgical methods for the treatment of glossopharyngeal neuralgia.

METHODS

During 1986 - 1998, 21 patients with glossopharyngeal neuralgia were treated microsurgically. Of whom, 5 patients were treated by microvascular decompression (MVD), 4 by MVD combined with rhizotomy of glossopharyngeal nerve root and upper 1st to 2nd rootlets of vagus nerve root, and 12 by rhizotomy of glossopharyngeal nerve root and upper 1st to 2nd rootlets of vagus nerve root.

RESULTS

Neuralgia disappeared in all patients postoperatively. In 3 patients, occasional coughing episodes occurred postoperatively. One of the 3 patients also suffered from mild hoarseness and swallowing difficulty. All patients were followed up on average 7.2 years with no recurrence.

CONCLUSIONS

MVD, rhizotomy of glossopharyngeal nerve root and upper 1st to 2nd rootlets of vagus nerve and their combination are effective for the treatment of glossopharyngeal neuralgia. Operative methods should be chosen according to the following two points: compression of nerve roots by affected vessels or not; and the condition of compression.