Tangential x-ray imaging crystal spectrometer on J-TEXT tokamak

A tangential x-ray imaging crystal spectrometer (XICS) has been developed for the J-TEXT tokamak to measure the ion temperature and the plasma toroidal rotation velocity. The resonance spectral line and its satellites of Ar XVII in the ranges of 3.94 Å-4.0 Å are detected. A spherically bent quartz crystal with 2d = 4.913 Å is used in this system. The crystal has a dimension of 9 cm high and 3 cm wide and the radius of curvature 3823 mm. The XICS is designed to receive emission of Ar XVII from -10 cm to +10 cm region with a spatial resolution of 3.1 cm in the vertical direction considering the parameters of the J-TEXT plasma. The XICS has a tangential angle of 27° with respect to toroidal direction in the magnetic axis. A two-dimensional 100 mm by 300 mm multi-wire proportional counter is applied to detect the spectra.

Note: measurement of the runaway electrons in the J-TEXT tokamak

The runaway electrons have been measured by hard x-ray detectors and soft x-ray array in the J-TEXT tokamak. The hard x-ray radiations in the energy ranges of 0.5-5 MeV are measured by two NaI detectors. The flux of lost runaway electrons can be obtained routinely. The soft x-ray array diagnostics are used to monitor the runaway beam generated in disruptions since the soft x-ray is dominated by the interaction between runaway electrons and metallic impurities inside the plasma. With the aid of soft x-ray array, runaway electron beam has been detected directly during the formation of runaway current plateau following the disruptions.

Rosuvastatin improves endothelial function in db/db mice: role of angiotensin II type 1 receptors and oxidative stress

BACKGROUND AND PURPOSE

HMG-CoA reductase inhibitors, statins, with lipid-reducing properties combat against atherosclerosis and diabetes. The favourable modulation of endothelial function may play a significant role in this effect. The present study aimed to investigate the cellular mechanisms responsible for the therapeutic benefits of rosuvastatin in ameliorating diabetes-associated endothelial dysfunction.

EXPERIMENTAL APPROACH

Twelve-week-old db/db diabetic mice were treated with rosuvastatin at 20 mg·kg⁻¹ ·day⁻¹ p.o.for 6 weeks. Isometric force was measured in isolated aortae and renal arteries. Protein expressions including angiotensin II type 1 receptor (AT₁R), NOX4, p22(phox) , p67(phox) , Rac-1, nitrotyrosine, phospho-ERK1/2 and phospho-p38 were determined by Western blotting, while reactive oxygen species (ROS) accumulation in the vascular wall was evaluated by dihydroethidium fluorescence and lucigenin assay.

KEY RESULTS

Rosuvastatin treatment of db/db mice reversed the impaired ACh-induced endothelium-dependent dilatations in both renal arteries and aortae and prevented the exaggerated contractions to angiotensin II and phenylephrine in db/db mouse renal arteries and aortae. Rosuvastatin reduced the elevated expressions of AT₁R, p22(phox) and p67(phox) , NOX4, Rac1, nitrotyrosine and phosphorylation of ERK1/2 and p38 MAPK and inhibited ROS production in aortae from db/db mice.

CONCLUSIONS AND IMPLICATIONS

The vasoprotective effects of rosuvastatin are attributed to an increase in NO bioavailability, which is probably achieved by its inhibition of ROS production from the AT₁R-NAD(P)H oxidase cascade.

Development of the heat treatment system for the 40 T hybrid magnet superconducting outsert

The heat treatment of Nb(3)Sn coil with the glass fabric insulation is one of the key and critical processes for the outsert solenoids of the 40 T hybrid magnet, which could be wound with cable-in-conduit conductors using the insulation-wind-and-react technique. The manufacturing of the large vertical type vacuum/Ar atmosphere-protection heat treatment system has been completed and recently installed in the High Magnetic Filed Laboratory, Chinese Academy of Sciences. The heat treatment system composed mainly the furnace, the purging gas supply system, the control system, the gas impurities monitoring system, and so on. At present, the regulation and testing of the heat treatment system has been successfully finished, and all of technical parameters meet or exceed specifications.

Measurements of the equations of state and spectrum of nonideal xenon plasma under shock compression

Experimental equations of state on generation of nonideal xenon plasma by intense shock wave compression was presented in the ranges of pressure of 2-16 GPa and temperature of 31-50 kK, and the xenon plasma with the nonideal coupling parameter Γ range from 0.6-2.1 was generated. The shock wave was produced using the flyer plate impact and accelerated up to ∼6 km/s with a two-stage light gas gun. Gaseous specimens were shocked from two initial pressures of 0.80 and 4.72 MPa at room temperature. Time-resolved spectral radiation histories were recorded by using a multiwavelength channel pyrometer. The transient spectra with the wavelength range of 460-700 nm were recorded by using a spectrometer to evaluate the shock temperature. Shock velocity was measured and particle velocity was determined by the impedance matching methods. The equations of state of xenon plasma and ionization degree have been discussed in terms of the self-consistent fluid variational theory.

Comparison between phytoestrogens and estradiol in the preventionof atheroma in ovariectomized cholesterol-fed rabbits

OBJECTIVES

There is increasing interest in the role of complementary and alternative medicines for the treatment of menopause-related problems. This study compared the preventive effect on atheroma formation of a commercially available mixed phytoestrogen concentrate with that of estradiol.

METHODS

An ovariectomized cholesterol-fed rabbit model of atheroma formation was used. Rabbits were ovariectomized before the commencement of the 12-week treatment period. There were two control groups. Control Group 1 received isoflavone-free rabbit chow whilst Control Group 2 received 1% cholesterol-enriched isoflavone-free rabbit chow. Rabbits in Group 3 received 1% cholesterol-enriched isoflavone-free rabbit chow plus a 500 mg tablet containing a concentrated extract of Trifolium pretense (red clover). Rabbits in Group 4 received 1% cholesterol-enriched isoflavone-free rabbit chow plus a 0.5 mg tablet of oral estradiol. Atheroma formation was measured by, first, calculation of the area of atheroma on the intimal surface, and, second, measuring the cholesterol content in the aorta.

RESULTS

There were no significant differences in serum cholesterol between the cholesterol-fed control Group 2 and the treatment Groups 3 and 4. However, there was significantly less staining for atheroma and significantly less cholesterol accumulation in the aorta in Group 4 (estradiol-treated) rabbits compared with either control Group 2 or Group 3 (phytoestrogen-treated) rabbits.

CONCLUSION

In this study, only estradiol was shown to have a significant protective effect against atheroma formation.

Joint toxicity evaluation and QSAR modeling of aromatic amines and phenols to bacteria

Acute toxicity of aromatic amines and phenols and their mixtures to bacteria in natural waters was determined and the median inhibition concentration IC(50) values for single compounds and IC(50mix) values for binary and multiple mixtures were obtained. Based on the quantitative structure-activity relationship model for single chemical toxicity, a two-descriptor model accounting for n-octanol/water partition coefficient (log P(mix)) and the energy of the lowest unoccupied molecular orbital (E(LUMOmix)) was developed for the toxicity of a mixture: log(1/IC(50mix) = 0.326 log P(mix) - 0.660E(LUMOmix) + 3.323 (n = 32, R(2) = 0.834). This model can be used successfully to predict the toxicity of a mixture, whether binary mixtures or multiple mixtures of three or four chemicals are used as predictors.

Preliminary experience with indications for liver transplantation for hepatolithiasis

OBJECTIVE

The aim of this study was to explore the indications for liver transplantation among patients with hepatolithiasis.

PATIENTS AND METHODS

Data from 1,431 consecutive patients who underwent surgical treatment from January 2000 to December 2006 were retrospectively collected for analysis. Surgical procedures included T-tube insertion combined with intraoperative cholangioscopic removal of intrahepatic stones, hepatectomy, cholangiojejunostomy, and liver transplantation.

RESULTS

Nine hundred sixty-one patients who had a stone located in the left or right intrahepatic duct underwent hepatectomy or T-tube insertion combined with intraoperative cholangioscopic removal of intrahepatic stones. The rate of residual stones was 7.5%. Four hundred seventy patients who had a stone located in the bilateral intrahepatic ducts underwent surgical procedures other than liver transplantation; the rate of residual stones was 21.7%. Only 15 patients with hepatolithiasis underwent liver transplantation; they all survived. According to the degree of biliary cirrhosis, recipients were divided into 2 groups: a group with biliary decompensated cirrhosis (n = 7), or group with compensated cirrhosis or no cirrhosis (n = 8). There were significant differences in operative times, transfusion volumes, and blood losses between the 2 groups (P < .05). In the first group, 6 of 7 patients experienced surgical complications, and in the second, 8 recipients recovered smoothly with no complications. Health status, disability, and psychological wellness of all recipients (n = 15) were significantly improved at 1 year after transplantation compared with pretransplantation (P < .05).

CONCLUSIONS

Liver transplantation is a possible method to address hepatolithiasis and secondary decompensated biliary cirrhosis or difficult to remove, diffusely distributed intrahepatic duct stones unavailable by hepatectomy, cholangiojejunostomy, and choledochoscopy.

Treatment of municipal wastewater with the sequence batch reactor under uncoupling metabolic conditions

The activated sludge process generates large quantities of excess sludge as by-product, which is one of the most serious challenges in biological wastewater treatment. In this study, the feasibility of 2,4,6-trichlorophenol (TCP) as metabolic uncoupler to reduce sludge generation in the Sequence Batch Reactor (SBR) for the long-term treatment of municipal wastewater was evaluated. The results of 90 days continuous treatment showed that 2 mg/L TCP reduced sludge generation by about 47%, while COD removal efficiency and sludge ability to settle were only slightly decreased. The specific substrate removal rate of sludge in the reactor with TCP exceeded the removal rate of sludge in the control reactor, indicating that the catabolism and anabolism of sludge in the reactor with TCP was uncoupled. Microscopic and 16s DNA analyses showed that the microbial population of sludge varied when TCP was fed into the SBR. The occurrence of filaments and the disappearance of some protozoa in the sludge system might be reasons for the slight variation of sludge ability to settle under uncoupled metabolic conditions.

Medicinal herbs for esophageal cancer

BACKGROUND

Esophageal cancer is the seventh leading cause of cancer death worldwide. Traditional Chinese medicinal herbs are sometimes used as an adjunct to radiotherapy or chemotherapy for this type of cancer.

OBJECTIVES

To assess the efficacy and possible adverse effects of the addition of Chinese medicinal herbs to treatment with radiotherapy or chemotherapy for esophageal cancer.

SEARCH STRATEGY

We searched the Cochrane Upper Gastrointestinal and Pancreatic Diseases Group Trials Register, The Cochrane Library, MEDLINE, EMBASE, AMED (Allied and Complementary Medicine Database), CBM (Chinese Biomedical Database), China National Knowledge Infrastructure, the Chinese Cochrane Centre Controlled Trials Register and CISCOM (The Research Council for Complementary Medicine) (up to June 2004). Databases of ongoing trials, the internet and reference lists were also searched.

SELECTION CRITERIA

Randomised controlled trials comparing the use of radiotherapy or chemotherapy with and without the addition of Chinese medicinal herbs.

DATA COLLECTION AND ANALYSIS

At least two review authors extracted data and assessed trial quality.

MAIN RESULTS

Two studies were included. The numbers of participants in these two trials were 42 and 80, 122 in total. Both studies were analysed separately because of the differences in interventions used. Although one study reported a positive result, the majority of outcome measurements from the two studies showed no significant benefit with the addition of Chinese herbal medicines to radiotherapy or chemotherapy. There was statistically significant improvement in quality of life with the additional Huachansu injection, however, no statistically significant improvement was found in short-term therapy effects, one-year survival rate or the adverse effect of radiation-induced esophagitis.

AUTHORS' CONCLUSIONS

The included studies were of low quality. The results suggest Zhenxiang capsules or Huachansu injection may not improve short-term therapy effects or one-year survival rate when used as adjunct treatment to chemo- or radiotherapy in the treatment of esophageal cancer. The quality of life may be improved by Huachansu injection. The results suggest that more high-quality trials on Huachansu injection and other Chinese herbal medicines are needed in the future.

Multiple void formation in plasmas containing multispecies charged grains

Self-organized separation of charged-dust species in two-dimensional dusty plasmas is studied by means of molecular-dynamics simulation. The multispecies dust grains, interacting through a screened Coulomb potential with a long-range attractive component, are confined by an external quadratic potential and subjected to a radially outward ion drag force. It is found that, in general, the species are spatially separated by bandlike dust-free (or void) regions, and grains of the same species tend to populate a common shell. At large ion drag and/or large plasma screening, a central disklike void as well as concentric bandlike voids separating the different species appear. Because of the outward drag and the attractive component of the dust-dust interaction forces, highly asymmetrical states consisting of species-separated dust clumps can also exist despite the fact that all the forces are either radial or central.

Tamoxifen dilates porcine coronary arteries: roles for nitric oxide and ouabain-sensitive mechanisms

BACKGROUND AND PURPOSE

Experiments were designed to determine the mechanism of the relaxation induced by tamoxifen in porcine coronary arteries at the tissue, cellular and molecular levels.

EXPERIMENTAL APPROACH

Porcine left circumflex coronary arteries were isolated and isometric tension was measured. [Ca2+]i in native endothelial cells of intact arteries was determined by a calcium fluorescence imaging technique and eNOS ser1177 phosphorylation was assayed by Western blotting.

KEY RESULTS

Tamoxifen induced an endothelium-dependent relaxation that was antagonized by ICI 182,780 and abolished by NG-nitro-L-arginine methyl ester (L-NAME) or 1H-[1,2,4]oxadizolo[4,3-a]quinoxalin-1-one (ODQ). L-Arginine reversed the effect of L-NAME while indomethacin was without effect. Tamoxifen-induced relaxation was attenuated by charybdotoxin (CTX) plus apamin, ouabain or by incubation in a K+ -free solution. Moreover, tamoxifen triggered extracellular Ca2+ -dependent increases in endothelial [Ca2+]i and this effect was abolished by ICI 182,780. Endothelium-independent relaxation to sodium nitroprusside was also inhibited by ouabain or in a K+ -free solution. Furthermore, tamoxifen increased endothelial nitric oxide synthase (eNOS) phosphorylation at Ser-1177 and ICI 182,780 prevented this effect.

CONCLUSIONS AND IMPLICATIONS

The present results suggest that tamoxifen mainly induces endothelium-dependent relaxation and that endothelial nitric oxide (NO) is the primary mediator of this effect. NO-dependent responses may result from elevated [Ca2+]i in endothelial cells; an effect abolished by ICI 182,780. NO activates Na+/K+ -ATPase in vascular smooth muscle, leading to relaxation. These results suggest that tamoxifen is able to modulate eNOS phosphorylation directly.

A novel method for analysis of single ion channel signal based on wavelet transform

A single ion channel signal was analysed by the power distribution fraction constructed by a discrete wavelet transform. Average opening time and energy distribution of the signal can be obtained directly by this method. The method can also be used when the signal is corrupted by noise. By contrast, the conventional frequency domain analysis method--power spectral density--is less effective. Power distribution fraction will therefore give more useful information in analysis of experimental ion channel signals, principally by giving values of the mean channel opening time. The method may be applied to distinguish different ion channels more efficiently and to find their reactions to drugs.

Structure of multispecies charged particles in a quadratic trap

Multispecies interacting charged particles in a two-dimensional quadratic trap are studied. The ground-state configurations for different particle and species numbers are obtained by molecular dynamics simulation. It is found that particles with similar mass-to-charge ratio tend to populate a common shell, whose location depends on the particle mass-to-charge ratio, and that the greater the latter, the closer are the particles to the center of the trap. This scaling for the ground-state configuration is independent of the total particle and species numbers in the system.

Six cases of ectopic ACTH syndrome caused by thymic carcinoid

The ectopic ACTH syndrome (EAS) caused by thymic carcinoid is rare and its diagnosis remains a challenge to the endocrinologist. Here are six cases of EAS with a typical Cushing habitus accompanied by hyperpigmentation and hypokalemia. For all six patients, the high dose (8 mg) dexamethasone suppression test (HDDST) showed lack of suppression, computed tomography (CT) scanning documented anterior mediastinal masses, and the mediastenal tumors removed were confirmed as ACTH secreting thymic carcinoids by positive ACTH and NSE staining. Our data indicate that HDDST chest radiologic imaging and other laboratory examinations will greatly assist in diagnosing the thymic carcinoid-induced EAS at an earlier stage, which will significantly improve the long-term survival of the patient.

AFM study of the effect of metronidazole on surface structures of sulfate-reducing bacteria

The effect of metronidazole (ME) on sulfate-reducing bacteria (SRB) was studied by atomic force microscopy (AFM) in this paper. Topography images of SRB cell show that after exposure to ME individual cell shape is sharply modified. Topography and phase images of SRB cell wall show that after exposure to ME not only the roughness of the cell wall increases but also the physical performance of SRB surface is changed to be uniform. AFM frictional loops show that after exposure to ME, SRB surface friction is increased remarkably.

An isoform of GTPase regulator DOCK4 localizes to the stereocilia in the inner ear and binds to harmonin (USH1C)

The driving forces for the regulation of cell morphology are the Rho family GTPases that coordinate the assembly of the actin cytoskeleton. This dynamic feature is a result of tight coupling between the cytoskeleton and signal transduction and is facilitated by actin-binding proteins (ABPs). Mutations in the actin bundling and PDZ domain-containing protein harmonin are the causes of Usher syndrome type 1C (USH1C), a syndrome of congenital deafness and progressive blindness, as well as certain forms of non-syndromic deafness. Here, we have used the yeast two-hybrid assay to isolate molecular partners of harmonin and identified DOCK4, an unconventional guanine exchange factor for the Rho family of guanosine triphosphatases (Rho GEF GTPases), as a protein interacting with harmonin. Detailed molecular analysis revealed that a novel DOCK4 isoform (DOCK4-Ex49) is expressed in the brain, eye and inner ear tissues. We have further provided evidence that the DOCK4-Ex49 binds to nucleotide free Rac as effectively as DOCK2 and DOCK4 and it is a potent Rac activator. By immunostaining using a peptide antibody specific to DOCK4-Ex49, we showed its localization in the inner ear within the hair bundles along the stereocilia (SC). Together, our data indicate a possible Rac-DOCK4-ABP harmonin-activated signaling pathway in regulating actin cytoskeleton organization in stereocilia.

Effects of isoflurane and propofol on cortical somatosensory evoked potentials during comparable depth of anaesthesia as guided by bispectral index

BACKGROUND

The aim of this study was to determine if propofol caused less suppression of cortical somatosensory evoked potentials (SSEPs) during spine surgery compared with isoflurane during comparable depth of anaesthesia as guided by bispectral index (BIS) measurements.

METHODS

This was a randomized controlled trial of propofol and isoflurane involving 60 patients undergoing elective spine surgery. BIS monitoring was used to guide a consistent and comparable depth of anaesthesia, the index was maintained at between 40 and 50 during anaesthesia. The cortical SSEP P40-N50 peak-to-peak amplitude and latency time to the P40 peak were measured before induction of anaesthesia, after induction of anaesthesia, at the start of skin incision, at the start of pedicle screw insertion and at the start of rod insertion, by a neurophysiologist blinded to drug allocation.

RESULTS

Both propofol and isoflurane decreased SSEP amplitude and increased latency during the course of anaesthesia. After achieving a comparable depth of anaesthesia, the SSEP amplitude was significantly lower with isoflurane, 1.5 (1.0) vs 2.4 (1.4) muV (P=0.005). Latency was significantly longer with isoflurane, 39.5 (3.9) vs 37.3 (3.1) ms (P=0.024). Isoflurane was associated with greater variability of SSEP amplitude during the course of anaesthesia and surgery, coefficient of variation 35.4 (18.0) vs 21.2 (10.2)% (P=0.008).

CONCLUSIONS

Propofol anaesthesia caused less suppression of the cortical SSEP, with better preservation of SSEP amplitude, and less variability at an equivalent depth of anaesthesia.

Silencing of episomal transgene expression by plasmid bacterial DNA elements in vivo

We previously demonstrated that sustainable enhanced levels of transgene products could be expressed from a bacterial DNA-free expression cassette either formed from a fragmented plasmid in mouse liver or delivered as a minicircle vector. This suggested that bacterial DNA sequences played a role in episomal transgene silencing. To further understand the silencing mechanism, we systematically altered the DNA components in both the expression cassette and the bacterial backbone, and compared the gene expression profiles from mice receiving different DNA forms. In nine vectors tested, animals that received the purified expression cassette alone always expressed persistently higher levels of transgene compared to 2fDNA groups. In contrast, animals that received linearized DNA by a single cut in the bacterial backbone had similar expression profiles to that of intact plasmid groups. All three linear DNAs formed large concatemers and small circles in mouse liver, while ccDNA remained intact. In all groups, the relative amount of vector DNA in liver remained similar. Together, these results further established that the DNA silencing effect was mediated by a covalent linkage of the expression cassette and the bacteria DNA elements.

Anti-proliferative and differentiation-inducing activities of the green tea catechin epigallocatechin-3-gallate (EGCG) on the human eosinophilic leukemia EoL-1 cell line

A novel approach for the treatment of leukemia is the differentiation therapy in which immature leukemia cells are induced to attain a mature phenotype when exposed to differentiation inducers, either alone or in combinations with other chemotherapeutic or chemopreventive drugs. Over the past decade, numerous studies indicated that green tea catechins (GTC) could suppress the growth and induce apoptosis on a number of human cancer cell lines. However, the differentiation-inducing activity of GTC on human tumors remains poorly understood. In the present study, the effect of the major GTC epigallocatechin-3-gallate (EGCG) on the proliferation and differentiation of a human eosinophilc leukemic cell line, EoL-1, was examined. Our results showed that EGCG suppressed the proliferation of the EoL-1 cells in a dose-dependent manner, with an estimated IC(50) value of 31.5 microM. On the other hand, EGCG at a concentration of 40 microM could trigger the EoL-1 cells to undergo morphological differentiation into mature eosinophil-like cells. Using RT-PCR and flow cytometry, it was found that EGCG upregulated the gene and protein expression of two eosinophil-specific granule proteins, the major basic protein (MBP) and eosinophil peroxidase (EPO), in EoL-1 cells. Taken together, our findings suggest that EGCG can exhibit anti-leukemic activity on a human eosinophilic cell line EoL-1 by suppressing the proliferation and by inducing the differentiation of the leukemia cells.

Electron acceleration and high-order harmonic generation by an intense short pulse laser in a magnetic field

Electron acceleration and short-wavelength radiation generation by an intense, short, linearly polarized laser pulse in an external magnetic field parallel to that of the light wave is investigated classically. It is found that enhanced electron acceleration by the laser can occur. After the pulse has passed, much of the energy gained by the electron is retained in its relativistic cyclotron motion. The electron emits radiation at high harmonics of the cyclotron frequency until the static magnetic field decays.

A novel locus for autosomal dominant non-syndromic deafness (DFNA41) maps to chromosome 12q24-qter

We have studied 36 subjects in a large multigenerational Chinese family that is segregating for an autosomal dominant adult onset form of progressive non-syndromic hearing loss. All affected subjects had bilateral sensorineural hearing loss involving all frequencies with some significant gender differences in initial presentation. After excluding linkage to known loci for non-syndromic deafness, we used the Center for Inherited Disease Research (CIDR) to test for 351 polymorphic markers distributed at approximately 10 cM intervals throughout the genome. Analysis of the resulting data provided evidence that the locus designated DFNA41 maps to a 15 cM region on chromosome 12q24.32-qter, proximal to the marker D12S1609. A maximum two point lod score of 6.56 at theta=0.0 was obtained for D12S343. This gene is distal to DFNA25, a previously identified locus for dominant adult onset hearing loss that maps to 12q21-24. Positional/functional candidate genes in this region include frizzled 10, epimorphin, RAN, and ZFOC1.

Effect of 17beta-estradiol exposure on vasorelaxation induced by K(+) channel openers and Ca(2+) channel blockers

17beta-Estradiol has been shown to relax blood vessels partly through inhibition of Ca(2+) channels at supraphysiological concentrations; however, it is unknown whether acute exposure of the isolated artery rings to near physiological concentrations of sex steroid hormones could modulate the ionic channels that are involved in regulation of vascular tone. Brief incubation (20 min) with 17beta-estradiol (1-3 nmol/l) did not alter the relaxant response to three blocking agents of L-type voltage-sensitive Ca(2+) channels, nifedipine, diltiazem and verapamil in either endothelium-intact or endothelium-denuded rat mesenteric artery rings. In contrast, 17beta-estradiol at 3 nmol/l significantly attenuated the relaxation induced by K(+) channel openers, cromakalim and pinacidil in endothelium-denuded rings. Similarly, preincubation with progesterone (3 nmol/l) inhibited pinacidil-induced relaxation with much less effect on cromakalim-induced relaxation. It appears that 17beta-estradiol and progesterone attenuated the cromakalim- and pinacidil-induced relaxation in a different manner. These results suggest that acute exposure to female sex steroid hormones at near physiological levels may reduce the activity of ATP-sensitive K(+) channels in the rat arteries.

NMR and monte carlo simulation studies of water adsorption dynamics

Nuclear magnetic resonance water proton spin-spin relaxation time T(2) was measured in wood samples with moisture contents ranging from 0.50 to 26.4%. The experimental results are discussed in terms of Monte Carlo simulations, which determine the correlation times tau for reorientation of the water molecule proton-proton vectors. We demonstrate that 1/T(2) and tau qualitatively follow the same behavior with surface hydration. The common application of the multisite exchange model to hydrated systems is discussed in light of the new results.

Stimulation of chloride secretion by baicalein in isolated rat distal colon

The effect of baicalein on mucosal ion transport in the rat distal colon was investigated in Ussing chambers. Mucosal addition of baicalein (1-100 microM) elicited a concentration-dependent short-circuit current (I(sc)) response. The increase in I(sc) was mainly due to Cl(-) secretion. The presence of mucosal indomethacin (10 microM) significantly reduced both the basal and subsequent baicalein-evoked I(sc) responses. The baicalein-induced I(sc) were inhibited by mucosal application of diphenylamine-2-carboxylic acid (100 microM) and glibenclamide (500 microM) and basolateral application of chromanol 293B (30 microM), a blocker of K(v)LQT1 channels and Ba(2+) ions (5 mM). Treatment of the colonic mucosa with baicalein elicited a threefold increase in cAMP production. Pretreating the colonic mucosa with carbachol (100 microM, serosal) but not thapsigargin (1 microM, both sides) abolished the baicalein-induced I(sc). Addition of baicalein subsequent to forskolin induced a further increase in I(sc). These results indicate that the baicalein evoked Cl(-) secretion across rat colonic mucosa, possibly via a cAMP-dependent pathway. However, the action of baicalein cannot be solely explained by its cAMP-elevating effect. Baicalein may stimulate Cl(-) secretion via a cAMP-independent pathway or have a direct effect on cystic fibrosis transmembrane conductance regulator.

Modulational instability of short-wavelength ion waves in strongly coupled dusty plasmas

Modulational instability of electrostatic short-wavelength ion waves in plasmas containing strongly coupled dusts with variable charge is considered. The evolution equations for the ion waves modulated by slow dust motion are obtained. The instability behavior differs considerably from that of plasmas with weakly coupled dust grains and depends strongly on the Coulomb coupling parameter as well as the dust-charge relaxation rate.

Cardiovascular actions of berberine

Berberine, is an alkaloid from Hydrastis canadensis L., Chinese herb Huanglian, and many other plants. It is widely used in traditional Chinese medicine as an antimicrobial in the treatment of dysentery and infectious diarrhea. This manuscript describes cardiovascular effects of berberine and its derivatives, tetrahydroberberine and 8-oxoberberine. Berberine has positive inotropic, negative chronotropic, antiarrhythmic, and vasodilator properties. Both derivatives of berberine have antiarrhythmic activity. Some cardiovascular effects of berberine and its derivatives are attributed to the blockade of K+ channels (delayed rectifier and K(ATP)) and stimulation of Na+ -Ca(2+) exchanger. Berberine has been shown to prolong the duration of ventricular action potential. Its vasodilator activity has been attributed to multiple cellular mechanisms. The cardiovascular effects of berberine suggest its possible clinical usefulness in the treatment of arrhythmias and/or heart failure.

Mutations in GJA1 (connexin 43) are associated with non-syndromic autosomal recessive deafness

Mutations in four members of the connexin gene family have been shown to underlie distinct genetic forms of deafness, including GJB2 [connexin 26 (Cx26)], GJB3 (Cx31), GJB6 (Cx30) and GJB1 (Cx32). We have found that alterations in a fifth member of this family, GJA1 (Cx43), appear to cause a common form of deafness in African Americans. We identified two different GJA1 mutations in four of 26 African American probands. Three were homozygous for a Leu-->Phe substitution in the absolutely conserved codon 11, whereas the other was homozygous for a Val-->Ala transversion at the highly conserved codon 24. Neither mutation was detected in DNA from 100 control subjects without deafness. Cx43 is expressed in the cochlea, as is demonstrated by PCR amplification from human fetal cochlear cDNA and by RT-PCR of mouse cochlear tissues. Immunohistochemical staining of mouse cochlear preparations showed immunostaining for Cx43 in non-sensory epithelial cells and in fibrocytes of the spiral ligament and the spiral limbus. To our knowledge this is the first alpha connexin gene to be associated with non-syndromic deafness. Cx43 must also play a critical role in the physiology of hearing, presumably by participating in the recycling of potassium to the cochlear endolymph.

Prevalence, incidence, and mortality of PD: a door-to-door survey in Ilan county, Taiwan

BACKGROUND

The reported prevalence and incidence rates of PD were significantly lower in China than those in Western countries. People in China and Taiwan have a similar ethnic background.

OBJECTIVE

To investigate the prevalence, incidence, and mortality rate of PD in Taiwan.

METHOD

The authors conducted a population-based survey using a two-stage door-to-door approach for patients aged 40 years or older in Ilan, Taiwan. Patients were diagnosed with PD by having at least two of the four cardinal signs of parkinsonism and exclusion of seconddary parkinsonism. To identify new cases of PD after the survey, patients with negative results of parkinsonism in the first stage were matched to the information on clinical diagnosis of PD from the Bureau of National Health Insurance toward the end of December 31, 1997. All cases of PD were linked to the Taiwan mortality registration to ascertain causes of deaths until December 31, 1999.

RESULTS

The participation rate was 88.1% among the 11,411 contacted individuals. Thirty-seven cases of PD were identified. The age-adjusted prevalence rate of PD for all age groups was 130.1 per 100,000 population after being adjusted to the 1970 US census, assuming no cases of PD would be found among those younger than 40 years of age. Of 9972 non-PD subjects in the first screen, 15 new cases of PD were ascertained. The age-adjusted incidence rate was 10.4 per 100,000 population for all age groups. The case fatality rate of PD after a 7-year follow-up was 40.4% (21 deaths in 52 patients with PD). The relative risk of death for PD cases versus non-PD cases was 3.38 (95% CI: 2.05-4.34). The 5-year cumulative survival rate in PD cases (78.85%) was statistically lower than that in non-PD cases (92.84%).

CONCLUSION

The prevalence and incidence rates of PD in Taiwan were much higher than those reported in China, but closer to those in Western countries. These results suggest that environmental factors may be more important than racial factors in the pathogenesis of PD.

Comparison of constitutive and inducible maize kernel proteins of genotypes resistant or susceptible to aflatoxin production

Maize genotypes resistant or susceptible to aflatoxin production or contamination were compared for differences in both constitutive and inducible proteins. Five additional constitutive proteins were found to be associated with resistance in over 8 of the 10 genotypes examined. Among these, the 58- and 46-kDa proteins were identified as globulin-1 and globulin-2, respectively. Differences in the ability to induce specific antifungal proteins, such as the higher synthesis of the 22-kDa zeamatin in resistant genotypes, were also observed between resistant and susceptible kernels incubated under germinating conditions (31 degrees C, 100% humidity). Both constitutive and inducible proteins appear to be necessary for kernel resistance. Embryo-killed kernels (unable to synthesize new proteins) supported the highest level of aflatoxins, whereas imbibed kernels (to hasten protein induction) supported the lowest among all treatments. This suggests that the synthesis of new proteins by the embryo plays an important role in conferring resistance. However, significantly lower levels of aflatoxin production in embryo-killed resistant kernels than in susceptible ones suggest that, in reality, high levels of constitutive antifungal proteins are indispensable to kernel resistance.

Phrenic nerve conduction study in patients with traumatic brachial plexus palsy

Phrenic nerve conduction studies were performed to assess the ipsilateral nerve in 100 patients with traumatic brachial plexus palsy. Open exploration and intraoperative recordings of somatosensory evoked potentials and nerve action potentials were used to confirm the level of root lesions. The relationship between C-5 preganglionic root lesion and the functional integrity of the ipsilateral phrenic nerve was examined. The phrenic nerves were normal in 80 cases, partially injured in 7, and severely injured in 13. We found C-5 preganglionic root lesions in 13 (100%) patients with severely injured, 5 (71.4%) with partially injured, and 24 (30%) with normal phrenic nerves. This correlation suggests phrenic nerve conduction study is a useful tool in the diagnosis of C-5 preganglionic root lesions in patients with traumatic brachial plexopathy.

Theaflavins in black tea and catechins in green tea are equally effective antioxidants

Green tea catechins, including (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG), are oxidized and dimerized during the manufacture of black tea and oolong tea to form orange-red pigments, theaflavins (TF), a mixture of theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B) and theaflavin-3,3'-digallate (TF3). The present study was designed to compare the antioxidant activities of individual TF with that of each catechin using human LDL oxidation as a model. All catechins and TF tested inhibited Cu(+2)-mediated LDL oxidation. Analysis of the thiobarbituric acid-reactive substances (TBARS) and conjugated dienes produced during LDL oxidation revealed that the antioxidant activity was in the order: TF3 > ECG > EGCG > or = TF2B > or = TF2A > TF1 > or = EC > EGC. Four TF derivatives also demonstrated a dose-dependent antioxidant activity in Cu(+2)-mediated LDL oxidation at concentrations of 5-40 micromol/L. These results demonstrate that the TF present in black tea possess at least the same antioxidant potency as catechins present in green tea, and that the conversion of catechins to TF during fermentation in making black tea does not alter significantly their free radical-scavenging activity.

Development of neurotrophic molecules for treatment of neurodegeneration

Over the past several years, neurotrophic factors have made considerable progress from the laboratory into the clinic. Evidence from preclinical and clinical studies indicates that it may be possible to use neurotrophic factors to prevent, slow the progression of, or even reverse the effects of a number of neurodegenerative diseases and other types of insults in both the central and peripheral nervous system. Their potential importance in the development of therapeutic agents against neurodegenerative disorders and nerve injury has led to a flurry of activity towards understanding their structure, function and signalling mechanisms. Approaches to develop pharmacological agents that target neurotrophic factors, their receptors or neurotrophic factors signalling pathways have been attempted. This review focuses on some of the major themes and lines of mechanistic and therapeutic advances in this fast-moving field of neuroscience.

Effects of butachlor on microbial populations and enzyme activities in paddy soil

This paper reports the influences of the herbicide butachlor (n-butoxymethlchloro -2', 6'-diethylacetnilide) on microbial populations, respiration, nitrogen fixation and nitrification, and on the activities of dehydrogenase and hydrogen peroxidase in paddy soil. The results showed that the number of actinomycetes declined significantly after the application of butachlor at different concentrations ranging from 5.5 microg g(-1) to 22.0 microg g(-1) dried soil, while that of bacteria and fungi increased. Fungi were easily affected by butachlor compared to the bacteria. The growth of fungi was retarded by butachlor at higher concentrations. Butachlor however, stimulated the growth of anaerobic hydrolytic fermentative bacteria, sulfate-reducing bacteria (SRB) and denitrifying bacteria. The increased concentration of butachlor applied resulted in the higher number of SRB. Butachlor inhibited the growth of hydrogen-producing acetogenic bacteria. The effect of butachlor varied on methane-producing bacteria (MPB) at different concentrations. Butachlor at the concentration of 1.0 microg g(-1) dried soil or less than this concentration accelerated the growth of MPB, while at 22.0 microg g(-1) dried soil showed an inhibition. Butachlor enhanced the activity of dehydrogenase at increasing concentrations. The soil dehydrogenase showed the highest activity on the 16th day after application of 22.0 microg g(-1) dried soil of butachlor. The hydrogen peroxidase could be stimulated by butachlor. The soil respiration was depressed during the period from several days to more than 20 days, depending on concentrations of butachlor applied. Both the nitrogen fixation and nitrification were stimulated in the beginning but reduced greatly afterwards in paddy soil.

Accumulation and apparent oxidation of cis,trans-18 : 2 isomers relative to linoleic acid in rats

Dietary cis,trans-18 : 2 isomers impair desaturation and elongation of linoleic acid (Delta9cis,12cis-18 : 2), but little is known of their proportional partitioning between accumulation and oxidation. The present study was therefore designed to assess the accumulation and apparent oxidation of cis,trans-18 : 2 isomers compared with that of trans-18 : 1 isomers and Delta9cis,12cis-18 : 2 in rats. Accumulation is defined as whole-body increase in a fatty acid during a given period (i.e. final body content-initial body content). The apparent oxidation (disappearance) is defined as whole-body utilization of a fatty acid relative to its intake for a given period (intake-excretion-accumulation-longer-chain products)/intakex100). The animals were fed on a diet containing 15 % (w/w) partially hydrogenated rapeseed oil with 1.72 % energy as cis,trans-18 : 2 isomers and varying amounts of Delta9cis,12cis-18 : 2. The apparent oxidation of total cis,trans-18 : 2 isomers (72-76 % dietary intake) was greater than that of Delta9cis,12cis-18 : 2 (38-51 % dietary intake) but it was similar to that of total trans-18 : 1 isomers (78-82 % dietary intake). Among the four isomers, the apparent oxidation of Delta9trans,12trans-18 : 2 was greater than that of the other isomers including Delta9trans,12cis-18 : 2, Delta9cis,12trans-18 : 2 and Delta9cis,13trans-18 : 2. Accumulation of Delta5cis,8cis,11cis,15trans-20 : 4 and Delta5cis,8cis,11cis,14trans-20 : 4 derived from chain-elongation and desaturation of Delta9cis,13trans-18 : 2 and Delta9cis,12trans-18 : 2 was decreased when the dietary Delta9cis,12cis-18 : 2 supply was increased.

Purification of phenylethanoids from Brandisia hancei and the antiproliferative effects on aortic smooth muscle

The present study describes the isolation and purification of acteoside, 2'-acetylacteoside, poliumoside and brandioside, four phenylethanoid glycosides from Brandisia hancei. We examined their effects on the proliferation of cultured A7r5 rat aortic smooth muscle cells. The proliferative response was measured from the [(3)H]-thymidine incorporation into DNA. All four glycosides suppressed the proliferative response in the presence of 2 % or 5 % fetal bovine serum in a concentration-dependent manner. The rank order of effectiveness for inhibition of cell proliferation was: brandioside > or = poliumoside > 2'-acetylacteoside > or = acteoside. The acetyl group at position 2' of glucose does not seem necessary for the anti-proliferative effects of acteoside and 2'-acetylacteoside, while the hydroxy groups of the aromatic rings appear to play a role. Inhibition of smooth muscle cell proliferation by phenylethanoids indicates that these compounds may have preventative effects on arteriosclerosis.

[Determination of organic acids in cigarette smoke]

Solid phase microextraction (SPME) is a simple, cost-effective, time-saving extraction technique. It is rapid and highly sensitive. In this study, organic acids in cigarette smoke were extracted with 85 microns polyacrylate coated fiber. Volatile and semi-volatile organic acids, such as butanoic acid, hexanoic acid, 2-furancarboxylic acid, octanoic acid, nonanoic acid, benzoic acid, phenylacetic acid, tetradecanoic acid, and hexadecanoic acid from cigarette smoke were converted to their esters by using methanolic derivatization agent. The esters were extracted by using headspace solid phase microextraction and determined quantitatively by gas chromatography with selected ion monitoring mode mass spectrometry. Qualitative analysis of 4 brands cigarette smoke demonstrated the usefulness of this analytical technique of volatile and semi-volatile acids in cigarette smoke. More than sixty organic acids were detected by using this method.

Gender difference in enzymes related with alcohol consumption in hamster, an avid consumer of alcohol

Syrian golden hamster (Mesocricetus auratus) is extraordinary among laboratory rodents in its ability to drink alcohol. After being given a free choice between 15% ethanol and water for 5 days, both male and female hamsters derived at least 85% of the fluid intake from the ethanol solution. Analysis of the alcohol-metabolizing enzymes in alcohol-naïve hamsters showed that the male had a higher activity of 57%, 58% and 34% in stomach alcohol dehydrogenase, liver cytochrome P450 1A2 and liver aldehyde dehydrogenase, respectively, compared with the female. The activity of lung angiotensin-converting enzyme, which influence fluid intake, was twofold higher in the male. After 4 weeks of ethanol consumption, the activities of the hepatic alcohol-metabolizing enzymes remained unchanged except cytochrome P450 2E1 which increased 42% and 88% in male and female hamsters, respectively. A reduction of approximately 80% in the activity of cytochrome P450 1A2 was observed in both genders. The activities of several other cytochrome P450 enzymes were also decreased. Although ethanol consumption did not increase plasma aminotransferase levels, it caused a significant increase in liver weight in female, but not male hamsters.

The 3'-end-processing factor CPSF is required for the splicing of single-intron pre-mRNAs in vivo

We describe a new approach to elucidate the role of 3'-end processing in pre-mRNA splicing in vivo using the influenza virus NS1A protein. The effector domain of the NS1A protein, which inhibits the function of the CPSF and PABII factors of the cellular 3'-end-processing machinery, is sufficient for the inhibition of not only 3'-end formation but also the splicing of single-intron pre-mRNAs in vivo. We demonstrate that inhibition of the splicing of single-intron pre-mRNAs results from inhibition of 3'-end processing, thereby establishing that 3'-end processing is required for the splicing of a 3' terminal intron in vivo. Because the NS1A protein causes a global suppression of 3'-end processing in trans, we avoid the ambiguities caused by the activation of cryptic poly(A) sites that occurs when mutations are introduced into the AAUAAA sequence in the pre-mRNA. In addition, this strategy enabled us to establish that the function of a particular 3'-end-processing factor, namely CPSF, is required for the splicing of single-intron pre-mRNAs in vivo: splicing is inhibited only when the effector domain of the NS1A protein binds and inhibits the function of the 30-kDa CPSF protein in 3'-end formation. In contrast, the 3'-end processing factor PABII is not required for splicing. We discuss the implications of these results for cellular and influenza viral mRNA splicing.

Glial cell line-derived neurotrophic factor enhances axonal regeneration following sciatic nerve transection in adult rats

Adult rat sciatic nerve was transected and sutured with an entubulation technique. The nerve interstump gap was filled with either collagen gel (COL) or collagen gel mixed with glial cell line-derived neurotrophic factor (COL/GDNF). Four weeks after nerve transection, horseradish peroxidase (HRP)-labelled spinal cord motoneurons and the myelinated distal stump axons were quantified. Compared with the COL group, the percentages of labeled spinal somas and axon number were significantly increased after topically applied glial cell line-derived neurotrophic factor (GDNF). The functional recovery of the transected nerve was improved in COL/GDNF group. GAP-43 expression was also significantly higher in COL/GDNF group 1 and 2 weeks after sciatic nerve axotomy vs. COL group. These data provide strong evidence that GDNF could promote axonal regeneration in adult rats, suggesting the potential use of GDNF in therapeutic approaches to peripheral nerve injury and neuropathies.

Antioxidative activities of phenylethanoid glycosides from Ligustrum purpurascens

Tea and kudingcha (bitter tea) are the two most popular beverages consumed in China. Tea derived from the leaves of Camellia sinensis has been well studied for its various health benefits, but there are very limited data on the biological activities of bitter tea derived from the leaves of Ligustrum purpurascens (LP). The present study was carried out to characterize the antioxidants present in the bitter tea brewed from the leaves of LP. It was found that the crude glycoside fraction possessed strong protection against oxidation of human low-density lipoprotein (LDL). The column chromatographic separation led to the isolatation of five phenylethanoid glycosides, namely, acteoside, ligupurpuroside A, cis-ligupurpuroside B, trans-ligupurpuroside B, and osmanthuside B. When acteoside was heated in the boiling water, it was isomerized to form isoacteoside. Acteoside, isoacteoside, and ligupurpuroside A purified from LP were protective, whereas cis-ligupurpuroside B, trans-ligupurpuroside B, and osmanthuside B exhibited no protection to human LDL from Cu(2+)-medicated oxidation. Acteoside, isoacteoside, and ligupurpuroside A were also effective in preventing the peroxyl free radical-induced oxidation of alpha-tocopherol in human LDL. The antioxidant activities of acteoside, isoacteoside, and ligupurpuroside A were comparable to that observed for a green tea antioxidant, (-)-epicatechin gallate. The inhibitory effect of these three phenylethanoid glycosides on oxidation of human LDL and alpha-tocopherol was dose-dependent at concentrations of 5-40 microM. The present results suggest that the bitter tea beverage derived from LP contains effective antioxidants that may have an equal benefit as a green tea beverage.

Relaxing effects of Ligstrum purpurascens extract and purified acteoside in rat aortic rings

The present study describes the effects of an extract obtained from the leaves of Ligstrum purpurascens and acteoside purified from the extract on the contractile response to various agonists in rat isolated aortic rings. L. purpurascens extract relaxed 9,11-dideoxy-11 alpha,9 alpha-epoxymethanoprostaglandin F2 alpha (U46619)-preconstricted rings in a concentration-dependent manner (IC50: 0.14 +/- 0.01 mg/ml with endothelium and 0.16 +/- 0.01 mg/ml without endothelium). The extract also reduced contraction induced by 35 mM K+ or by 1 microM phorbol 12,13-diacetate (PDA) in endothelium-intact rings. The extract (0.1-0.3 mg/ml) reduced the concentration-response to U46619 in normal Krebs solution or to CaCl2 in 35 mM K(+)-containing solution. Acteoside accounts for 2.05% of total L. purpurascens extract in weight. Acteoside induced relaxation of rings preconstricted by U46619 (IC50: 0.22 +/- 0.01 mg/ml) but it caused an increase in 35 mM K(+)-induced tone. Removal of endothelium enhanced the relaxing effect of acteoside. Besides, pretreatment with acteoside inhibited endothelium/nitric oxide-mediated relaxation induced by acetylcholine. These results indicate that acteoside is unlikely the major ingredient responsible for the vasodilator effect of L. purpurascens extract. The extract relaxed the preconstricted aortic rings probably through multiple mechanisms by acting on smooth muscle cells. The inhibitory effect on endothelial nitric oxide-mediated relaxation suggests that acteoside could also act on the endothelial cells to reduce nitric oxide release.

Vasorelaxant effects of cardamonin and alpinetin from Alpinia henryi K. Schum

The vascular effects of cardamonin and alpinetin from Alpinia henryi K. Schum. were examined in the rat isolated mesenteric arteries. 1H and 13C nuclear magnetic resonance spectra showed that cardamonin is present in trans-form, and single-crystal radiographic structure revealed that alpinetin is present in S configuration. Both cardamonin and alpinetin produced a rightward shift in the concentration-response curve for phenylephrine in a noncompetitive manner, and they induced relaxation of phenylephrine-preconstricted arteries with respective mean inhibitory concentrations (IC50) of 9.3+/-0.6 microM and 27.5+/-2.8 microM. Both compounds also relaxed arteries preconstricted by endothelin I or U46619. Their relaxant effects were decreased in endothelium-removed rings. Pretreatment with N(G)-nitro-L-arginine methyl ester or methylene blue inhibited relaxation induced by both agents, and pretreatment with L-arginine reversed the effect of N(G)-nitro-L-arginine methyl ester on cardamonin-induced endothelium-dependent relaxation. The relaxant effects of cardamonin and alpinetin were unaffected by indomethacin (3 microM). Cardamonin and alpinetin inhibited 60 mM K+-induced contraction with respective IC50 of 11.5+/-0.3 microM and 37.9+/-3.6 microM. In addition, both agents inhibited the transient contraction induced by 3 microM phenylephrine or by 10 mM caffeine in Ca2+-free Krebs solution. Finally, these two agents also concentration dependently relax the arteries preconstricted by 1 microM phorbol 12,13-diacetate in Ca2+-free Krebs solution. These results indicate that purified cardamonin and alpinetin from A. henryi K. Schum. relaxed rat mesenteric arteries through multiple mechanisms. They induced both endothelium-dependent and -independent relaxation; the former is likely mediated by nitric oxide whereas the latter is probably mediated through nonselective inhibition of Ca2+ influx and intracellular Ca2+ release and inhibition of the protein kinase C-dependent contractile mechanism.

Myosin-VIIb, a novel unconventional myosin, is a constituent of microvilli in transporting epithelia

Mouse myosin-VIIb, a novel unconventional myosin, was cloned from the inner ear and kidney. The human myosin-VIIb (HGMW-approved symbol MYO7B) sequence and exon structure were then deduced from a human BAC clone. The mouse gene was mapped to chromosome 18, approximately 0.5 cM proximal to D18Mit12. The human gene location at 2q21.1 was deduced from the map location of the BAC and confirmed by fluorescence in situ hybridization. Myosin-VIIb has a conserved myosin head domain, five IQ domains, two MyTH4 domains coupled to two FERM domains, and an SH3 domain. A phylogenetic analysis based on the MyTH4 domains suggests that the coupled MyTH and FERM domains were duplicated in myosin evolution before separation into different classes. Myosin-VIIb is expressed primarily in kidney and intestine, as shown by Northern and immunoblot analyses. An antibody to myosin-VIIb labeled proximal tubule cells of the kidney and enterocytes of the intestine, specifically the distal tips of apical microvilli on these transporting epithelial cells.

Variation in in vitro alpha-amylase and protease activity is related to the virulence of Aspergillus flavus isolates

Variation in the ability of Aspergillus flavus isolates to spread between cotton boll locules was previously shown to be at least partially related to variation in the production of a specific polygalacturonase (pectinase P2C). To determine if non-pectolytic hydrolase differences between low- and high-virulence isolates exist and, thus, could also potentially contribute to virulence differences, the present investigation was undertaken. Two A. flavus isolates, AF12 with low virulence and lacking pectinase P2C and AF13 with high virulence and producing pectinase P2C, were compared for production of nonpectolytic hydrolases after growth in 10% potato dextrose broth. Activity of amylases, cellulases, xylanases, and proteases was quantified using the radial diffusion/cup plate technique followed by differential staining. Culture filtrates also were subjected to native polyacrylamide gel electrophoresis. Both isolates produced amylases, proteases, and xylanases, whereas cellulases were not detected for either. AF13 produced more amylase than AF12, and this difference was supported by amylase isoform differences between isolates on native polyacrylamide gel electrophoresis gels. AF13 also produced more protease than AF12; however, isoform differences between isolates were inconclusive. These variations in other hydrolytic activities (besides pectinases) may contribute to virulence differences in cotton bolls between AF12 and AF13.

Resistance to aflatoxin accumulation in kernels of maize inbreds selected for ear rot resistance in West and Central Africa

Thirty-six inbred lines selected in West and Central Africa for moderate to high resistance to maize ear rot under conditions of severe natural infection were screened for resistance to aflatoxin contamination using the previously established kernel screening assay. Results showed that more than half the inbreds accumulated aflatoxins at levels as low as or lower than the resistant U.S. lines GT-MAS:gk or MI82. In 10 selected aflatoxin-resistant or aflatoxin-susceptible inbreds, Aspergillus flavus growth, which was quantified using an A. flavus transformant containing a GUS-beta-tubulin reporter gene construct, was, in general, positively related to aflatoxin accumulation. However, one aflatoxin-resistant inbred supported a relatively high level of fungal infection, whereas two susceptibles supported relatively low fungal infection. When kernels of the 10 tested lines were profiled for proteins using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, significant variations from protein profiles of U.S. lines were observed. Confirmation of resistance in promising African lines in field trials may significantly broaden the resistant germplasm base available for managing aflatoxin contamination through breeding approaches. Biochemical resistance markers different from those being identified and characterized in U.S. genotypes, such as ones inhibitory to aflatoxin biosynthesis rather than to fungal infection, may also be identified in African lines. These discoveries could significantly enhance the host resistance strategy of pyramiding different traits into agronomically useful maize germplasm to control aflatoxin contamination.