Cross-sectional and dynamic change of serum metabolite profiling for Hepatitis B-related acute-on-chronic liver failure by UPLC/MS

Summary Acute-on-chronic liver failure(ACLF) is an increasingly recognized entity encompassing an acute deterioration of liver function and results in the failure of one or more organs with high short-term mortality. The focus of this study was to discover noninvasive and reliable biomarkers for the diagnosis and prognosis of hepatitis B-related ACLF. Ultra-performance liquid chromatography-mass spectrometry (UPLC/MS) was used to analyse serum metabolites of 28 patients with hepatitis B-related ACLF, 35 patients with Child-Pugh A cirrhosis, 30 patients with chronic hepatitis B and 35 healthy volunteers (HS). Characteristic metabolites were screened, identified and dynamically tracked to investigate their value for diagnosis and prognosis. After comparing serum metabolic profile of hepatitis B-related ACLF and Child-Pugh A cirrhosis, 99 characteristic metabolites were selected, and 38 of them were identified. Dynamic tracking model demonstrated that 17 metabolites were related to prognosis of hepatitis B-related ACLF, and there were also 11 metabolites which improved with treatment in the survival group. The correlations between these characteristic metabolites and the model for end-stage liver disease score were strong. These observations contributed to the investigation of the mechanisms of hepatitis B-related ACLF manifestation and progression on the metabolic level, and they provided information for the identification of biomarkers for the diagnosis and prognosis of hepatitis B-related ACLF.

NMDA receptor signaling mediates the expression of protein inhibitor of activated STAT1 (PIAS1) in rat hippocampus

Protein inhibitor of activated STAT1 (PIAS1) was shown to play an important role in inflammation and innate immune response, but how PIAS1 is regulated is not known. We have recently demonstrated that PIAS1 enhances spatial learning and memory performance in rats. In this study, we examined the signaling pathway and neural mechanism that regulate PIAS1 expression in the brain by using pharmacological and molecular approaches. Our results revealed that pias1 gene expression is rapidly induced upon NMDA receptor activation in rat hippocampus, but this effect is blocked by transfection of sub-threshold concentrations of ERK1 siRNA/ERK2 siRNA or CREB siRNA. Pias1 gene expression is similarly induced by overexpression of the ERK1/ERK2 plasmids in rat hippocampus, and this effect is also blocked by sub-threshold concentration of CREB siRNA transfection. On the other hand, transfection of ERK1 siRNA/ERK2 siRNA or CREB siRNA at a higher concentration is sufficient to down-regulate PIAS1 expression. Inhibition of PI-3 kinase signaling and CaMKII signaling, which both result in CREB inactivation, similarly decreases PIAS1 expression. But NMDA and MK-801 do not affect the expression of IL-6 and TNFα. NMDA also did not affect the expression of PIAS2, PIAS3 and PIAS4. Further, pias1 mRNA has a similar degradation rate to that of the zif268 gene. These results together suggest that pias1 may function as an immediate early gene in an activity-dependent manner and PIAS1 expression is regulated by the NMDA-MAPK/ERK-CREB signaling pathway implicated in neuronal plasticity.

First Report of Powdery Mildew on Euphorbia pekinensis Caused by Podosphaera euphorbiae-helioscopiae in China

Euphorbia pekinensis Rupr, the Peking spurge, is a perennial grass that is planted throughout northeast China. Its roots can be used as a Chinese medicine for diuretic or purgative purposes. Some diterpenoids isolated from Euphorbia spp. show strong antitumor, antivirus, skin-irritating, and tumor-promoting activities. Some species contain chemicals that can be used as pesticides. In September and October 2009, spurge plants were seriously infected by powdery mildew fungi in Changchun Agri-Expon, Jilin Province, China. White mildew colonies appeared in early autumn and initial colonies coalesced to cover the entire upper sides of leaves, stems, and petals 3 to 4 weeks after the disease was noticed. Until late October, chasmothecia were observed on leaves and stems and the infected areas also became dark brown. Mycelium was amphigenous, in patches, white, and persistent. Conidia with distinct fibrosin bodies were ellipsoid-cylindrical, 21.6 to 33.8 × 12 to 15.6 μm, and produced in chains. Germ tubes arose near a pole of the conidia and terminated in simple, unlobed apices. Conidiophores were 59.8 to 139.9 μm; foot cells were straight to slightly flexuous, followed by one to three cells, and 24 to 48 × 8.4 to 10.8 μm. Hyphal appressoria were papillate. Chasmothecia were 70 to 95 μm in diameter, averaging 79.4 μm, and were immersed in mycelia. Mycelioid appendages (5 to 12) occurred in the lower part of the chasmothecia and were flexuous, curved, thick walled, and strongly undulate. Appendages were long (349-) 490 to 1,000 (-1,300) μm, averaging 759.4 μm. They were often densely crowded around the chasmothecia. Asci were single, sessile or short stalked, 60 to 80 × 45 to 70 μm, and eight spored. Ascospores were ellipsoid-ovoid and 16.8 to 28.8 × 10.8 to 18 μm. The fungus was identified as Podosphaera euphorbiae-helioscopiae on the basis of morphological characteristics of the anamorphic and teleomorphic stages. An herbarium specimen was deposited in the Herbarium of Mycology of Jilin Agriculture University (CJLCC100). Genomic DNA was extracted from the chasmothecia, and the internal transcribed spacer region (ITS) and the D1/D2 domains of the 28S rDNA were amplified and sequenced (GenBank Nos. JF795490 and JF795491). The ITS sequence has 98% identity with those of Podosphaera lini, P. macularis, and P. spiraeae, and the D1-D2 sequence of 28S rDNA has 99% identity with those of P. negeri and P. spiraeae, which indicated that this fungus belongs to the genus Podosphaera, even though there is no direct sequence evidence that it is P. euphorbiae-helioscopiae. P. euphorbiae-helioscopiae has only been previously reported in Japan (2), occurring on Euphorbia helioscopia. This species is unique because of the long and curved, thick-walled appendages, and there is no comparable species (1). P. euphorbiae-hirtae and P. euphorbiae are reported to infect Euphorbiaceae plants. Both species differ from P. euphorbiae-helioscopiae in their conspicuously shorter appendages (1,3). To our knowledge, this is the first reported occurrence of powdery mildew on E. pekinensis, and P. euphorbiae-helioscopiae is new to China. This is also the first description of the anamorph of the fungus since there is no record in the Erysiphales Database. References: (1) U. Braun. Nova Hedwigia 89:1, 1987. (2) Y. Nomura. Taxonomical Study of Erysiphaceae of Japan. Yokendo LTD, Tokyo, 1997. (3) R. Y. Zheng and Y. N. Yu. Flora Fungorum Sinicorum. Vol. 1. Erysiphales. Science Press, Beijing, 1987.

Immunoglobulin G4-related sclerosing disease: experience with this novel entity in a local hospital

OBJECTIVE

To review the site of involvement, clinical presentation, and treatment outcome of patients having immunoglobulin G4-related sclerosing disease in a local regional hospital.

DESIGN

Retrospective case series.

SETTING

Pamela Youde Nethersole Eastern Hospital, Hong Kong.

PATIENTS

All patients with a diagnosis of immunoglobulin G4-related sclerosing disease in the hospital diagnosed in the period from April 2008 to March 2010.

RESULTS

A total of 12 patients with involvement of various organs were identified. There was a male predominance (male-to-female ratio=5:1). The mean age at diagnosis was 65 years. The salivary glands, biliary tract, pancreas, and cervical lymph nodes were the commonest involved sites. The immunoglobulin G4 level was elevated in 83% of the patients. Patients usually appeared to respond well to steroid treatment.

CONCLUSION

Immunoglobulin G4-related sclerosing disease is a systemic disease and can involve various systems.

Astragaloside IV synergizes with ferulic acid to inhibit renal tubulointerstitial fibrosis in rats with obstructive nephropathy

BACKGROUND AND PURPOSE

The combination of Chinese herbs, Astragali Radix and Angelicae Sinensis Radix, could alleviate renal interstitial fibrosis. Astragaloside IV (AS-IV) and ferulic acid (FA) are the two major active constituents in this combination. In this study, we employed rats with unilateral ureteral obstruction to determine whether AS-IV and FA have the same renoprotective effects and investigated the mechanisms of this action.

EXPERIMENTAL APPROACH

Renal pathological changes were evaluated after treatment with AS-IV, FA or AS-IV + FA (AF) for 10 days. Meanwhile, the expression of transforming growth factor β₁ (TGF-β₁), fibronectin, α-smooth muscle actin (α-SMA), phosphorylation of c-Jun NH₂-terminal kinase (p-JNK) and nitric oxide (NO) production in kidney were determined. The expressions of fibronectin, α-SMA, mitogen-activated protein kinases [JNK, extracellular signal-regulated kinases (ERK), P38] in TGF-β₁-treated NRK-49F cells or interleukin-1-treated HK-2 cells after AS-IV, FA or AF were assessed.

KEY RESULTS

AF alleviated the infiltration of mononuclear cells, tubular atrophy and interstitial fibrosis; reduced the expression of fibronectin, α-SMA, TGF-β₁ and p-JNK; and dramatically increased the production of NO in obstructed kidneys. Neither AS-IV nor FA alone improved renal damage, but both increased NO production. AF inhibited α-SMA and fibronectin expression in NRK-49F or HK-2 cells. Furthermore, AF significantly inhibited IL-1β-induced JNK phosphorylation, without affecting ERK or P38 phosphorylation. Neither AS-IV nor FA alone had any effect on the cells.

CONCLUSIONS AND IMPLICATIONS

AS-IV synergizes with FA to alleviate renal tubulointerstitial fibrosis; this was associated with inhibition of tubular epithelial–mesenchymal transdifferentiation (EMT) and fibroblast activation, as well as an increase in NO production in the kidney.

Thermoelectric power in graphene

Considering electron-impurity and electron-phonon scattering, we present a balance-equation-based theoretical examination of thermoelectric power (TEP) in a two-dimensional single-layer graphene away from the carrier neutrality point. Both the boundary scattering and phonon-phonon interaction in phonon relaxation processes are taken into account. We find that, at temperatures T > 10 K, the contribution to TEP mainly comes from diffusive processes and the phonon-drag effect can be ignored. However, at T ≤ 10 K, the phonon-phonon interaction leads to a phonon-drag peak in the temperature dependence of TEP. We also compare our results with experiments.

The pink membrane: the stable photoproduct of deionized purple membrane

When cations are removed from the purple membrane of Halobacterium halobium it turns blue (lambda(max) = 603 nm); continuous irradiation with intense red light (lambda's >/= 630 nm) converts this deionized blue membrane into a pink membrane (lambda(max) approximately 491 nm). The rate and extent of the transformation from the blue to the pink membrane is facilitated by the removal of the last twenty COOH-terminal amino acids of bacteriorhodopsin. While the chromophore of the blue membrane is a 32:68 mixture of the 13-cis and all-trans isomers of retinal, the chromophore of the pink membrane is 9-cis rectinal. The quantum efficiency of the pink to blue membrane photoconversion is relatively high compared with that of the blue to pink membrane photoconversion. Proton release is observed when the pink membrane is converted to the blue form, and proton uptake occurs during the reverse transition. Unlike the blue membrane, the absorbance maximum of the pink membrane is only slightly affected by cation addition at low pH and ionic strength.

Light-induced currents from oriented purple membrane: I. Correlation of the microsecond component (B2) with the L-M photocycle transition

When irradiated, purple membrane from Halobacterium halobium oriented in a polyacrylamide gel produces a photocurrent. The correlation of the microsecond component (B2) of the photocurrent with the L-M optical transition was studied. It was found that the lifetimes of B2 and the L-M transition are identical over the entire pH range from 2.4 to 11.0 when measured in high salt (>5 mM CaCl(2) or >40 mM KCl). Changing the temperature from 10 to 35 degrees C, or replacing the H(2)O with D(2)O maintains this correlation. The amplitude of B2 and the L-M transition are also correlated over the pH range where both of them can be represented as a single exponential. At high pH (>8), three exponentials were required to fit both the optical and photocurrent signals. Two of them are the previously described fast and slow components of M formation, but a new intermediate with a very fast lifetime, 0.3 mus, was observed both in absorption (lambda = 410 nm) and photocurrent measurements. The lifetimes of all three were found to be pH independent. This would exclude models for the L to M portion of the photocycle that explained its complex pH-dependent behavior as being due to a single pH-dependent rate constant. The area of B2, which is proportional to the number and the distance the charge moved during the transition, is almost constant from pH 5.0 to pH 8.0. It decreases to almost zero at pH 2.0 and pH 10.6 with pKs at 2.8 and 9.1. Because B2 is thought to normally reflect proton release from the membrane, this suggests at very low and high pH the photocycle does not pump protons. The pK at high pHs for the formation of the nonpumping photocycle is probably related to the formation of a new photocycle featuring the fast rising form of M.

Construction of a BAC library and a physical map of a major QTL for CBB resistance of common bean (Phaseolus vulgaris L.)

A major quantitative trait loci (QTL) conditioning common bacterial blight (CBB) resistance in common bean (Phaseolus vulgaris L.) lines HR45 and HR67 was derived from XAN159, a resistant line obtained from an interspecific cross between common bean lines and the tepary bean (P. acutifolius L.) line PI319443. This source of CBB resistance is widely used in bean breeding. Several other CBB resistance QTL have been identified but none of them have been physically mapped. Four molecular markers tightly linked to this QTL have been identified suitable for marker assisted selection and physical mapping of the resistance gene. A bacterial artificial chromosome (BAC) library was constructed from high molecular weight DNA of HR45 and is composed of 33,024 clones. The size of individual BAC clone inserts ranges from 30 kb to 280 kb with an average size of 107 kb. The library is estimated to represent approximately sixfold genome coverage. The BAC library was screened as BAC pools using four PCR-based molecular markers. Two to seven BAC clones were identified by each marker. Two clones were found to have both markers PV-tttc001 and STS183. One preliminary contig was assembled based on DNA finger printing of those positive BAC clones. The minimum tiling path of the contig contains 6 BAC clones spanning an estimated size of 750 kb covering the QTL region.

Spin polarization induced by in-plane electric and magnetic fields in two-dimensional heavy-hole systems

Using a nonequilibrium Green function approach, we systematically investigate the current induced spin polarization (CISP) in a two-dimensional heavy-hole system with cubic Rashba spin-orbit coupling, driven by in-plane electric and magnetic fields. We find that when a magnetic field is applied along the direction of electric field, the longitudinal conductivity drops monotonously with an increase of magnetic-field strength or of hole density. The spin polarization along the electric-field direction is just the Pauli paramagnetism and it quadratically increases with an increase of hole density. The nonvanishing out-of-plane component of spin polarization emerges for both short-range and long-range disorders, and it changes sign with the variation of magnetic field, especially for long-range hole-impurity scattering. In the magnetic-field dependences of this out-of-plane CISP and of the in-plane CISP perpendicular to the electric field, there are singular magnetic fields, below or above which the effects of magnetic field are completely different.

Energy spectrum and density of states for a graphene quantum dot in a magnetic field

In this paper, we determine the spectrum and density of states of a graphene quantum dot in a normal quantizing magnetic field. To accomplish this, we employ the retarded Green function for a magnetized, infinite-sheet graphene layer to describe the dynamics of a tightly confined graphene quantum dot subject to Landau quantization. Considering a δ((2))(r) potential well that supports just one subband state in the well in the absence of a magnetic field, the effect of Landau quantization is to 'splinter' this single energy level into a proliferation of many Landau-quantized states within the well. Treating the graphene sheet and dot as a closed system subject to a fully Hermitian Hamiltonian (including boundary conditions), there is no indication of decay of the Landau-quantized graphene dot states into the quantized states of the host graphene sheet for 'tight' confinement by the δ((2))(r) potential well, notwithstanding extension of the dot Green function (and eigenfunctions) outside the δ((2))(r) potential well.

Rat Dlx5 is expressed in the subventricular zone and promotes neuronal differentiation

The molecular mechanisms and potential clinical applications of neural precursor cells have recently been the subject of intensive study. Dlx5, a homeobox transcription factor related to the distal-less gene in Drosophila, was shown to play an important role during forebrain development. The subventricular zone (SVZ) in the adult brain harbors the largest abundance of neural precursors. The anterior SVZ (SVZa) contains the most representative neural precursors in the SVZ. Further research is necessary to elucidate how Dlx5-related genes regulate the differentiation of SVZa neural precursors. Here, we employed immunohistochemistry and molecular biology techniques to study the expression of Dlx5 and related homeobox genes Er81 and Islet1 in neonatal rat brain and in in vitro cultured SVZa neural precursors. Our results show that Dlx5 and Er81 are also highly expressed in the SVZa, rostral migratory stream, and olfactory bulb. Islet1 is only expressed in the striatum. In cultured SVZa neural precursors, Dlx5 mRNA expression gradually decreased with subsequent cell passages and was completely lost by passage four. We also transfected a Dlx5 recombinant plasmid and found that Dlx5 overexpression promoted neuronal differentiation of in vitro cultured SVZa neural precursors. Taken together, our data suggest that Dlx5 plays an important role during neuronal differentiation.

Nonlinear dc transport in graphene

Considering electron-impurity, electron-acoustic-phonon and electron-optical-phonon scatterings, the nonlinear steady-state transport properties of graphene are studied theoretically by means of the balance equation approach. We find that the conductivity as a function of electric field strength, E, exhibits strongly nonlinear behavior for E larger than a critical value, E(c)≈0.1 kV cm(-1). With the increase of E from zero, the conductivity first decreases slowly and then it falls rapidly when E>E(c). The dependence of electron temperature on E is also demonstrated.

Properties of murine embryonic stem cells maintained on human foreskin fibroblasts without LIF

In embryonic stem (ES) cells, leukemia inhibitory factor (LIF)/STAT3, wnt and nodal/activin signaling are mainly active to control pluripotency during expansion. To maintain pluripotency, ES cells are typically cultured on feeder cells of varying origins. Murine ES cells are commonly cultured on murine embryonic fibroblasts (MEFs), which senesce early and must be frequently prepared. This process is laborious and leads to batch variation presenting a challenge for high-throughput ES cell expansion. Although some cell lines can be sustained by exogenous LIF, this method is costly. We present here a novel and inexpensive culture method for expanding murine ES cells on human foreskin fibroblast (HFF) feeders. After 20 passages on HFFs without LIF, ES cell lines showed normal expression levels of pluripotency markers, maintained a normal karyotype and retained the ability to contribute to the germline. As HFFs do not senesce for at least 62 passages, they present a vast supply of feeders.

Unfolding core asymmetries with x-ray emission images in symmetry diagnostic experiments

A novel inversion technique is proposed to unfold core asymmetries at the source with x-ray emission images, which were obtained from imploded surrogate capsules in symmetry diagnostic experiments. The axisymmetrical core emission can be expanded as a Fourier series, with Legendre polynomials and spherical Bessel functions as bases concerned with polar angle and radius, respectively. A least-squares estimator is employed to obtain the unknown coefficients from its two-dimensional image data. The unfolded Legendre coefficients can be further used to test modeling of drive asymmetries in hohlraums. This technique is also demonstrated with a proof-of-principle experiment performed on the Shenguang II laser facility [L. Zunqi et al., Chin. J. Lasers B10, 6 (2001)].

Characterisation of plasmids encoding CTX-M-3 extended-spectrum β-lactamase from Enterobacteriaceae isolated at a university hospital in Taiwan

CTX-M-3 is the most common extended-spectrum beta-lactamase produced by Enterobacteriaceae in Taiwan. The present study was conducted to characterise the genetic environment surrounding bla(CTX-M-3). A total of 11 ceftriaxone-resistant isolates were studied: Escherichia coli (n=4), Klebsiella pneumoniae (n=5) and Salmonella enterica serotypes Anatum (SA831R) and Potsdam (SC72). Molecular methods used included polymerase chain reaction, sequencing, DNA-DNA hybridisation, conjugation, physical mapping and restriction fragment length polymorphism (RFLP) analysis. All isolates examined carried bla(CTX-M-3) on large plasmids (>70kb). The resistance plasmids of the two Salmonella and two K. pneumoniae strains (KP104 and KP116) were confirmed to be conjugative in vitro. RFLP analysis indicated that the plasmids were different. Physical mapping also revealed the difference between the two Salmonella plasmids, pSA831R (82kb) and pSC72 (74kb). An insertion sequence, ISEcp1, was found upstream of each bla(CTX-M-3) gene. However, sequencing of downstream regions of the bla genes showed two different patterns: the presence of orf477 in pSA831R and of orf1-mucA in pSC72, pKP104 and pKP116. IncI1-type oriT and nikA sequences were present in the plasmids of all the clinical isolates tested, except S. Anatum. Different bla(CTX-M-3)-carrying plasmids were identified among the enterobacteria studied. The presence of ISEcp1 in all isolates may be associated with the widespread resistance among Enterobacteriaceae. Although the plasmids were not identical, they appeared to belong to the same incompatibility group (IncI1-like plasmids), suggesting that they are genetically related but may have evolved divergently over time.

White organic light-emitting devices with Sm:Ag black cathode

White organic light-emitting device (WOLED) with Sm:Ag black cathode was first reported. The effect of the black cathode on the performances (such as efficiency, luminance, contrast ratio at different angle and EL spectra, etc) of the WOLEDs was discussed. We found that the efficiency of the WOLED with Sm:Ag was comparable to that of the device with conventional Mg:Ag cathode. For example, the efficiency of the device with Sm:Ag cathode is just 15% lower than that of the device with Mg:Ag cathode. However, the contrast ratio (CR) of the device with black cathode is 105:1 under 140 lx ambient lighting at a high brightness of 1000 cd/m(2), which is four times better than that of the device with Mg:Ag cathode. Besides, the CR of the WOLED with Sm:Ag cathode is insensitive to the viewing angle less than 50 degrees .

Contrast and efficiency enhancement in organic light-emitting devices utilizing high absorption and high charge mobility organic layers

Organic light-emitting devices utilizing copper phthalocyanine (CuPc) and C(60) as the hole- and electron-injection layers were reported. Compared with a conventional device without CuPc and C(60) layers, the improvement of the contrast is more than 100% under 140-lx ambient lighting at a brightness of 300 cd/m(2). A maximum current efficiency of 3.93 cd/A, which is higher than 3.62 cd/A for a conventional device, was obtained at 9 V. The device has a maximum luminance of 17170 cd/m(2) at 15 V. The high contrast and high efficiency of the device are attributed to the high absorption and high charge mobility of CuPc and C(60) films.

Analysis of MS2Bnap genomic DNA homologous to MS2 gene from Arabidopsis thaliana in two dominant digenic male sterile accessions of oilseed rape (Brassica napus L.)

PCR technique was employed to isolate gene homologous to the MS2Bnap (X99922.1) from two rapeseed (Brassica napus L.) dominant digenic male sterile lines, namely 220A (male sterile) and 220B (male fertile), 6A (male sterile) and 6C (male fertile). The isolated 2,581 bp sequences from 220A (named 220A-gDNA, GenBank accession number AY288778), 220B (220B-gDNA, AY257490), 6A (6A-gDNA, DQ060318) and 6C (6C-gDNA, DQ060319) all contained six introns. Forty-one single nucleotide polymorphism (SNP) sites were detected by alignment of these four sequences, seven of them dispersed in the exon regions. Two SNPs (1247, 1656) were detected between 220A-gDNA and 220B-gDNA, and the one at nucleotide 1247 of 220A-gDNA with A replaced by C was a missense mutation, which may be the putative male sterility site in 220A. All eight SNPs identified between 6A-gDNA and 6C-gDNA were located in the third intron, so the proteins encoded by them are the same. The one SNP between 6A-/6C-gDNA and 220A-/220B-gDNA at nucleotide 2474 of 220A-/220B-gDNA with C replaced by G was a missense mutation. Mutation site of BNMS2PROT (CAA68190.1) encoded by MS2Bnap in 220A(254) and 6A/6C(584) is different, which indicated dominant digenic male sterile line 220AB and 6CA have some difference in the molecular level. Comparison of structure of MS2Bnap in B. napus with that of MS2 in Arabidopsis thaliana revealed that the similarity of exons between these two genes is higher than that of introns.

Integron-associated imipenem resistance in Acinetobacter baumannii isolated from a regional hospital in Taiwan

We investigated the genetic properties of imipenem-resistant Acinetobacter baumannii collected from a regional hospital in Taiwan. Pulsed-field gel electrophoresis demonstrated that the isolates were genetically diverse. Polymerase chain reaction, DNA sequencing, and DNA-DNA hybridisation showed that the bla(IMP-1) gene resided as a cassette in a plasmid-borne class 1 integron in two isolates. The majority of the resistant isolates were plasmid-less and carried no bla(IMP), bla(VIM) or bla(CFI) genes, indicating that other uncharacterised metallo-beta-lactamases or mechanisms other than enzyme production are involved in carbapenem resistance in this group of A. baumannii. We conclude that multidrug resistance of A. baumannii was a combined effect of lateral gene transfer and clonal spread of multiple resistant clones. Strict measures should be implemented to control the further spread of resistance.

DOT and timely treatment completion among Asian-born immigrant tuberculosis patients

SETTING

A large urban tuberculosis (TB) control program.

OBJECTIVES

To identify factors associated with directly observed therapy (DOT) participation and to quantify how early use of DOT affected treatment duration.

DESIGN

A retrospective study of 731 Asian-born patients with drug-susceptible Mycobacterium tuberculosis isolates who were verified in New York City between 1993 and 1997 and completed treatment.

RESULTS

Overall, 297 (41%) of 731 patients in the study participated in DOT for some or all of their TB treatment. DOT participation was significantly associated with TB disease in a pulmonary site (adjusted odds ratio [aOR] 2.85, 95% CI 1.86-4.35), more recent year of diagnosis (aOR 1.70, 95% CI 1.50-1.94) and male sex (aOR 1.86, 95% CI 1.30-2.66). Patients who received > or = 70% of their TB treatment at a health department chest clinic were also significantly more likely to participate in DOT (aOR 3.83, 95% CI 2.55-5.74). Among 297 DOT patients, those who completed treatment by 9 months received a greater amount of treatment by DOT during the first 4 months of treatment than those who took longer to complete treatment.

CONCLUSION

Earlier DOT participation can lead to overall shorter treatment duration. Health care providers should encourage TB patients to participate in DOT as early as possible in their TB treatment.

Thomson scattering measurements of heat flux from ion-acoustic waves in laser-produced aluminum plasmas

Thomson scattering (TS) measurements are performed at different locations in a laser-produced aluminum plasma. Variations of the separation, wavelength shift, and asymmetric distribution of the two ion-acoustic waves are investigated from their spectral-time-resolved TS images. Detailed information on the space-time evolution of the plasma parameters is obtained. Electron distribution and variation of the heat flux in the plasma are also obtained for a steep temperature gradient.

Volumetric productivity improvement for endoglucanase of Trichoderma pseudokoingii S-38

AIMS

The objective of this study was to design an economically feasible process for endoglucanase (EG) production.

METHODS AND RESULTS

Trichoderma pseudokoingii S-38 EG synthesis was studied. Initially, either glucose at 2.5, 5 or 10 g l-1, or cellulose powder (CF11) at 5 g l-1 was used as the sole carbon source. The results showed that enzyme synthesis and biomass formation were closely correlated, and both were affected by the carbon source. To improve EG volumetric product efficiency, a new technique was developed. Glucose and CF11 (2.5 and 5 g l-1, respectively) were used as initial carbon source, and glucose was added at 2.5 g l-1 day-1. EG activity, volumetric and specific EG productivities were 6.17 IU l-1, 53 IU l-1 h-1 and 114.3 IU (g cell protein)-1 h-1, respectively. Batch production in a 2-l laboratory fermenter confirmed the advantage of the technique. The product contained 10.86 IU ml-1 EG activity in 88 h. The volumetric and specific EG productivities were 123.4 IU l-1 h-1 and 177.8 IU (g cell protein)-1 h-1, respectively.

CONCLUSIONS

These results suggest that optimization of the ratio of glucose to CF11 for balancing the induction and growth rate in the production of EG may lead to technical and economical benefits.

SIGNIFICANCE AND IMPACT OF THE STUDY

A new technique was developed for the production of EG which improves both the volumetric product efficiency and the specific activity.

Radiation-induced magnetoresistance oscillation in a two-dimensional electron gas in Faraday geometry

Microwave-radiation induced giant magnetoresistance oscillations recently discovered in high-mobility two-dimensional electron systems are analyzed theoretically. Multiphoton-assisted impurity scatterings are shown to be the primary origin of the oscillation. Based on a theory which considers the interaction of electrons with electromagnetic fields and the effect of the cyclotron resonance in Faraday geometry, we are able not only to reproduce the correct period, phase, and the negative resistivity of the main oscillation, but also to predict the secondary peaks and additional maxima and minima observed in the experiments. These peak-valley structures are identified to relate, respectively, to single-, double-, and triple-photon processes.

Inhibition of protein phosphatase 2A- and protein phosphatase 1-induced tau hyperphosphorylation and impairment of spatial memory retention in rats

Tau hyperphosphorylation leads to formation of paired helical filament/neurofibrillary tangles, the hallmark lesion seen in Alzheimer's disease (AD) brain. An imbalanced regulation in protein kinases and protein phosphatases in the affected neurons is proposed to be a reasonable causative factor to the disease process. To verify the hypothesis, we have injected in the present study calyculin A, a potent and specific inhibitor of protein phosphatase (PP) 2A and PP1, into rat hippocampus bilaterally, thus reproduced an Alzheimer's-like deficiency in dephosphorylation system. It was found that calyculin A-injected rats developed lesions in spatial memory retention in Morris water maze test. At mean time, tau was hyperphosphorylated at Ser396/Ser404 (PHF-1) and Ser-262/Ser-356 (12E8) sites determined both by immunohistochemistry and Western blot. It is implicated that (1) PP2A and PP1 participate in the in vivo regulation of tau phosphorylation, and down-regulation of the two phosphatases will result in tau hyperphosphorylation; (2) hyperphosphorylation of tau at PHF-1 and 12E8 sites might be crucial to affect spatial memory in AD.

Arsenic trioxide in comparison with chemotherapy and bone marrow transplantation for the treatment of relapsed acute promyelocytic leukaemia

BACKGROUND

The best overall treatment strategy for patients with acute promyelocytic leukaemia (APL) in relapse with chemotherapy, bone marrow transplantation (BMT) or arsenic trioxide (As(2)O(3)) based therapy remains undefined.

PATIENTS AND METHODS

We reviewed the clinical course and treatment outcome of 143 APL cases seen in four major hospitals in Hong Kong over a 10-year period.

RESULTS

Complete remission (CR) was attained in 113 cases (79%) with all-trans retinoic acid (ATRA) and chemotherapy. Relapse occurred at a median of 16 months in 54 cases, with a 3-year disease free survival of 56%. Post-relapse treatment was successful in 41 cases (76%), giving an actuarial 3-year overall survival (OS) of 81% from CR1. Three different protocols were used: chemotherapy alone (n = 19), allogeneic BMT (n = 14) and an As(2)O(3)-based regimen (n = 21). Chemotherapy was associated with the highest treatment-related mortality (TRM) at 53%, giving a CR2 rate of 47%. TRM was 36% for BMT. The CR2 rate for the As(2)O(3)-based regimen was 100%, with no TRM. However, 38% of As(2)O(3) treated patients had subsequent relapses, which were further salvaged in 75% by combined As(2)O(3) plus ATRA. The actuarial OS for the three protocols leveled off by 2 years at 82% for As(2)O(3), 43% for BMT and 23% for chemotherapy (P = 0.0004).

CONCLUSIONS

Our results suggest that As(2)O(3) may be superior to chemotherapy and BMT for the treatment of APL in relapse.

Bilateral parotid and submandibular gland enlargement: rare features of Wegener's granulomatosis

Wegener's granulomatosis is a potentially fatal disease of unknown origin affecting mainly the upper and lower respiratory tracts and kidneys. Prompt recognition of the more unusual presentations of the disease is necessary to ensure early treatment. We present a case of a 46-year-old female with bilateral submandibular and parotid gland enlargement. Parotid or submandibular salivary gland enlargement is a rare presenting feature of Wegener's granulomatosis. Common to 80 per cent of these cases is nasal involvement, while ear pathology or lung lesions may occur in the remaining cases. The diagnosis is both clinical and pathological, biopsy of suspicious tissue, serum c-ANCA levels and a chest X-ray are valuable investigations. Treatment with immunosuppressive therapy is essential, and usually ensures a long-term remission.

A surprisingly mild and versatile method for palladium-catalyzed Suzuki cross-couplings of aryl chlorides in the presence of a triarylphosphine

In the presence of new air-stable triarylphosphine 2, palladium-catalyzed Suzuki reactions of a wide array of aryl chlorides can be accomplished in uniformly good yield, including couplings of very sterically demanding and electronically deactivated substrates; activated aryl chlorides can be coupled at room temperature. In terms of scope and mildness, Pd-2 compares well with other catalyst systems that have been described for Suzuki reactions of aryl chlorides, thereby establishing that triarylphosphines should be regarded as fertile ground for future ligand-design efforts for palladium-catalyzed couplings of aryl chlorides.

Comparisons of hydroperoxide isomerase and monooxygenase activities of cytochrome P450 for conversions of allylic hydroperoxides and alcohols to epoxyalcohols and diols: probing substrate reorientation in the active site

Ferric cytochrome P450 (P450) catalyzes intramolecular rearrangements of hydroperoxides to diols by heterolytic scission of the O-O bond and insertion of the terminal oxygen atom into the resulting alcohol. The goals of this work were to further characterize the regio- and stereochemistry of P450 isomerase activity using allylic hydroperoxides and to compare these reactions with NADPH-supported monooxygenations of the corresponding alcohols. Microsomes from phenobarbital-treated rats or purified P450 2B1 catalyzed the conversions of several peroxyquinols, including 2-tert-butyl-4-hydroperoxy-4-methylcyclohexa-2,5-dien-1-one (BMPOOH) and its 2,6-dimethyl derivative (TMPOOH), to diols and to alpha,beta-epoxyquinols by predominant (>93%) cis addition of oxygen to the least hindered double bond. Monooxygenation of the 4-hydroxy analogues (quinols) yielded identical cis-epoxyquinols, and both isomerization and monooxygenation reactions exhibited similar enantioselectivities (32-74% enantiomer excess). Regioselectivities were similar for BMPOOH and BMPOH (epoxyquinol:diol ratios of 5.8-7.6), but quite different for TMPOOH and TMPOH (ratios of 0.6 and 6.4, respectively). Bulky peroxyquinols and quinols derived from the A-rings of 17beta-estradiol and estrone were utilized to further compare these reactions. Both estradiol derivatives underwent approximately equal amounts of 6beta-hydroxylation and 1,2-epoxidation. The estrone derivatives also underwent 6beta-hydroxylation, but only estrone quinol yielded a second product consistent with hydroxylation at position 16. The results support several conclusions. (i) Allylic hydroperoxides may be isomerized to alpha,beta-epoxyalcohols by a heterolytic O-O cleavage mechanism with high stereoselectivity. (ii) Hydroperoxide isomerization is an efficient process relative to monooxygenation. (iii) Isomerase substrates remain in proximity to the P450 oxoferryl intermediate and are rapidly captured by the oxidant. Monooxygenase substrates, on the other hand, may bind to ferric P450 in multiple orientations and undergo more extensive substrate reorientation prior to oxidative attack.

Synthesis and structural comparison of a series of divalent Ln(Tp(R,R)')2 (Ln = Sm, Eu, Yb) and trivalent Sm(Tp(Me2))2X (X = F, Cl, I, BPh4) complexes

Reaction of LnI2 (Ln = Sm, Yb) with two equivalents of NaTp(Me2) or reduction of Eu(Tp(Me2))2OTf gives good yields of the highly insoluble homoleptic Ln(II) complexes, Ln(Tp(Me2))2 (Ln = Sm (1a), Yb (2a), Eu (3a)). Use of the additionally 4-ethyl substituted Tp(Me2,4Et) ligand produces the analogous, but soluble Ln(Tp(Me2,4Et))2 (1-3b) complexes. Soluble compounds are also obtained with the Tp(Ph) and Tp(Tn) ligands (Tn = thienyl), Ln(Tp(Ph))2 (Ln = Sm, 1c; Yb, 2c) and Ln(Tp(Tn))2 (Ln = Sm, 1d; Yb, 2d). To provide benchmark parameters for structural comparison the series of Sm(Tp(Me2))2X complexes (X = F, 1e; Cl, 1f; Br, 1g; I, 1h; BPh4, 1j) were prepared either via oxidation of the Sm(Tp(Me2))2 or salt metathesis from SmX3 (X = Cl, Br, I). The solid-state structures of 1-3a, 1b, 1-2c and 1e, 1f, 1h, and 1j were determined by single-crystal X-ray diffraction. The homoleptic bis-Tp complexes are all six-coordinate with trigonal antiprismatic geometries, planes of the kappa(3)-Tp ligands are parallel to one another. In the series of Sm(Tp(Me2))2X complexes the structure changes from seven-coordinate molecular compounds, with intact Sm-X bonds, for X = F, Cl, to six-coordinate ionic structures [Sm(Tp(Me2))2]X (X = I, BPh4), suitable crystals of the bromide compound could not be obtained. The dependence of the structures on the size of X is understandable in terms of the interplay between the size of the cleft that the [Sm(Tp(Me2))2](+) fragment can make available and the donor ability of the anionic group toward the hard Sm(III) center.

Direct projections from serotonergic neurons in the dorsal and median raphe nuclei of midbrain to the suprachiasmatic nucleus in Tupaia belangeri chinensis

This study investigated the direct serotonergic projections to the suprachiasmatic nucleus (SCN) from the dorsal and median raphe nuclei (DR/MR) of the midbrain in Tupaia belangeri chinensis (TBC) by combined application of retrograde horseradish peroxidase (HRP) tract tracing, immunohistochemistry, and electron microscope techniques. The results provide evidence for the direct projections to the SCN from serotonergic neurons distributed predominantly in the MR (mainly in its lateral portion) and to a lesser degree in the DR (in its ventrolateral portion) more caudally in the midbrain, and the existence of abundant symmetrical and asymmetrical synaptic connections between the serotonergic terminals and the postsynaptic elements in the SCN TBC. The results also revealed that almost all DR neurons projecting to the SCN contained serotonin, whereas about one-half of MR neurons projecting to the SCN were immunoreactive for serotonin.

Regulation of the strypsin-related proteinase ISP2 by progesterone in endometrial gland epithelium during implantation in mice

Hormones prepare the uterus for the arrival and subsequent invasion of the embryo during pregnancy. Extracellular matrix-degrading proteinases and their inhibitors are involved in this integration process. Recent genetic evidence indicates that there is redundancy within the implantation proteinase cascade, indicating that additional proteinases may be involved. Recently, we described a novel implantation serine proteinase (ISP1) gene that encodes the embryo-derived enzyme strypsin, which is necessary for blastocyst hatching in vitro and the initiation of invasion. The evidence presented in the present study indicates that a second proteinase secreted from the uterus also participates in lysis of the zona pellucida. A second implantation serine proteinase gene (ISP2) was isolated, which encodes a related secreted tryptase expressed specifically within uterine endometrial glands. In pseudopregnancy, ISP2 gene expression is dependent on progesterone priming and is inhibited by the antiprogestin RU486. On the basis of similarities between ISP2 gene expression and that of a progesterone-regulated luminal proteinase associated with lysis of the zona pellucida, it is possible that the strypsin-related protein, ISP2, may encode a zona lysin proteinase.

A novel murine tryptase involved in blastocyst hatching and outgrowth

Before implantation the blastocyst is maintained within a proteinaceous coat, the zona pellucida, which prevents polyspermy and ectopic pregnancy. An extracellular trypsin-like activity, which is necessary for hatching from the zona pellucida in vitro, is localized to the abembryonic pole of the blastocyst. Upon hatching, the extracellular matrix-degrading proteinases urokinase plasminogen activator (uPA) and matrix metalloproteinase 9 (MMP-9) are thought to promote blastocyst invasion. However, gene disruption experiments have demonstrated that uPA and MMP-9 are dispensable and, thus, that other key enzymes are involved in implantation. In this study, a novel implantation serine proteinase (ISP1) gene, which is distantly related to haematopoietic tryptases and represents a novel branch of the S1 proteinase family, was cloned. ISP1 is expressed throughout morulae and blastocysts during hatching and outgrowth. Abrogation of ISP1 mRNA accumulation using antisense oligodeoxynucleotides disrupts blastocyst hatching and outgrowth in vitro. The results of this study indicate that the ISP1 gene probably encodes the long sought after 'hatching enzyme' that is localized to the abembryonic pole during hatching in vitro. ISP1 is the earliest embryo-specific proteinase to be expressed in implantation and may play a critical role in connecting embryo hatching to the establishment of implantation competence at the abembryonic pole of the blastocyst.

A BAC-Based STS-Content Map Spanning a 35-Mb Region of Human Chromosome 1p35–p36

We have devised a mapping method for rapid assembly and ordering of bacterial artificial chromosome (BAC) clones on a radiation hybrid (RH) panel, using sequence-tagged sites (STSs) and PCR. The protocol consists of two rounds of two-dimensional screening from a limited number of BACs to correspond each to an STS. In the first round, STSs are assembled in the RH bins and ordered according to PCR signals derived from 384-well microtiter plates (MTPs) in which BAC clones have been arrayed. In the second round, individual BAC clones are isolated from the MTPs to build a contig. We applied this method to a 35-Mb region spanning human chromosome 1p35-p36 and assembled 1366 BACs in 11 contigs, the longest being about 20 Mb. The working draft sequences of the human genome have been integrated into the contigs to validate the accuracy.

Solid-state structure and solution behavior of eight-coordinate Sm(III) poly(pyrazolyl)borate compounds

[Sm(Tp(Me2)(2)(kappa(2)-S(2)CNR(2))] compounds (R = Et (1), Me (2); Tp(Me2) = HB(3,5-Me2pz)(3)) have been isolated from reaction of (R(2)NC(S)S)(2) with 2 equiv of [Sm(Tp(Me2)(2)]. Reductive cleavage of 2,2'-dipyridyl disulfide or 2,2'-dipyridyl diselenide by [Sm(Tp(Me2)(2)] afforded good yields of [Sm(Tp(Me2)(2)(kappa(2)-Y)] compounds (Y = 2-SC(5)H(4)N (3), 2-SeC(5)H(4)N (4)). 4 is the first selenopyridine complex of an f-block element. Sm(Tp(Me2)(2)(2-OC(5)H(4)N) (5) has been synthesized by salt metathesis of [Sm(Tp(Me2)(2)Cl] with the sodium salt of the 2-hydroxypyridine. The solid-state structures of 1, 3, 4, and 5 were determined by single-crystal X-ray diffraction analysis and revealed that the compounds are all eight-coordinate with dodecahedral geometry. The samarium atoms are bound in tridentate fashion to two pyrazolylborate ligands and in bidentate fashion by the third ligand. The solution behavior of the compounds was studied by (1)H NMR techniques. (1)H-(1)H exchange spectroscopy experiments give evidence for two distinct dynamic regimes occurring in solution.

Adenoma of the posterior urethra: 131 case report

AIM

A case-report on adenoma of the posterior urethra.

METHODS

In 131 cases of adenoma of the posterior urethra, aged 17-79 (mean: 36.4) years, a detailed medical history was taken and urinalysis, urethroscopy, and prostatic specific antigen (PSA) immunohistochemical staining were performed. They were then treated with transurethral resection (TUR) or transurethral electric coagulation (TUEC).

RESULTS

Hemospermia occurred in 51% of the cases, hematuria in 38%, blood overflow from the urethral orifice in 6%, and dysuria in 5%. The position of the tumor was at or around the verumontanum. The appearance of the tumor was similar to those of a papilla, a villus, a dactyl or polyp, or simply an engorgement. The tumor contained glandular alveoli and adeno-epithelial cells. PSA immunohistochemistry was positive in the cytoplasm and nucleus of the adeno-epithelial cell. One hundred and tweenty-nine cases were cured after TUR or TUEC, while 2 patients recurred and were operated again.

CONCLUSION

Adenoma of the posterior urethra is a common cause of hemospermia and hematuria in young men. Urethroscopic examination and biopsy are the principal diagnostic measures. TUR or TUEC are believed to be the treatment of choice with a short-term recurrence rate of around 1. 5%.

HPLC and GC-MS screening of Chinese proprietary medicine for undeclared therapeutic substances

Traditional Chinese medicine includes raw medicinal materials and Chinese proprietary medicine (CPM). Despite being of natural origin, toxic effects, adulteration with synthetic therapeutic substances and even deaths had been associated with CPM. There is thus a need to develop analytical technique to rapidly screen for undeclared toxic and therapeutic substances in CPM. In this study, a high performance liquid chromatography-diode-array detection method was developed and used to screen for undeclared therapeutic substances in CPM. An ultraviolet (UV) library of 266 drugs had been compiled. Solute identification was performed by comparing the analytical data (UV spectra, retention time and relative retention time) with those of the 266 standards. Gas chromatography-mass spectrometry was used as a confirmation method. These chromatographic methods had been shown to be selective and reproducible in screening for undeclared drugs in CPM. Using the method developed, 41 CPM samples in seven categories were screened for undeclared therapeutic substances. One anti-asthmatic CPM was found to contain codeine.

Absence of p53-mediated G1 arrest with induction of MDM2 in sterigmatocystin-treated cells

P53 plays a critical role in G1 checkpoint after DNA damage. MDM2 gene is a p53 target gene and its protein forms a feedback loop with p53 and inhibits p53-mediated G1 arrest. Sterigmatocystin (ST) is a mycotoxin and carcinogen. In this study we show that exposure of cells to ST for 12 or 24 h resulted in failure of G1 arrest at both time points. Accordingly, p53 protein was not increased and p21WAF1 expression was inhibited at 12 h, and both proteins were weakly induced at 24 h after treatment with ST. Meanwhile, MDM2 protein was induced in a p53-dependent fashion by ST at both 12 and 24 h. The induction of MDM2 was coincident with the cellular responses of p53 and p21WAF1, and might contribute to the failure of G1 arrest in ST-treated cells. In addition, ST-treated cells exhibited G2M arrest, regardless of p53 status. Our results indicate that the carcinogenic effects of ST seem to be mediated by failure of p53-mediated G1 checkpoint.

[Nasopharyngeal submucous carcinoma with the first show of cervical lymphnode swell]

OBJECTIVE

To understand the nasopharyngeal submucous carcinoma with the first show of cervical lymph node swell.

METHOD

To collect the clinical data of 4 patients with such disease.

RESULT

The 4 cases of nasopharyngeal submucous carcinoma were not diagnosed until 3-6 months after cervical lymphnode metastasis. All patients received radiotherapy, three died within 1 year and another survived.

CONCLUSION

If some patients have cervical lymph node swell, pay attention to the metastasis of nasopharyngeal submucous carcinoma firstly. Even the examinations such as cytologic test, VCA-IgA, CT, MRI were negative, or even tuberculomas had been diagnosed, nasopharyngeal submucous carcinoma still can not be excluded.

Lanthanide chalcogenolate complexes: synthesis and crystal structures of the isoleptic series [Sm(TpMe,Me)2ER] (E = O, S, Se, Te; TpMe,Me = tris-3,5-dimethylpyrazolylborate)

A series of lanthanide complexes containing a chalcogenolate ligand supported by two TpMe,Me (tris-3,5-dimethylpyrazolylborate) groups has been prepared and crystallized and provides direct comparisons of bonding to hard and soft ligands at lanthanide centers. Reaction of [Sm(TpMe,Me)2Cl] with NaOR (R = Ph, Ph-Bu(t)) gives [Sm(TpMe,Me)2OR] (1a and 1b, respectively) in good yields. Reductive cleavage of dichalcogenides by samarium(II) was used to prepare the heavier congeners. Complexes of the type [Sm(TpMe,Me)2ER] for E = S, R = Ph (2a), E = S, R = Ph-4-Me (2b), E = S, R = CH2Ph (2c), E = Se, R = Ph (3a), E = Se, R = Ph-4-Bu(t) (3b), E = Se, R = CH2Ph (3c), and E = Te, R = Ph (4) have been prepared together with the corresponding complexes with TpMe,Me,4-Et as ancillary. The X-ray crystal structures of 1b, 2b, 3a, 3b, and 4 have been determined. The crystal of 1b (C40H57B2N12OSm.C7H8) was monoclinic, P2(1)/c, a = 10.6845(6) A, b = 18.5573(11) A, c = 24.4075(14) A, beta = 91.616(2) degrees, Z = 4. The crystal of 2b (C37H51B2N12SSm) was monoclinic, P2(1)/n, a = 15.0154(9) A, b = 13.1853(8) A, c = 21.1254(13) A, beta = 108.628(2) degrees, Z = 4. The crystal of 3a (C36H49B2N12SeSm.C7H8) was triclinic, P1, a = 10.7819(6) A, b = 19.3011(10) A, c = 23.0235(12) A, alpha = 79.443(2) degrees, beta = 77.428(2) degrees, gamma = 89.827(2) degrees, Z = 4. The crystal of 3b (C40H57B2N12SeSm) was triclinic, P1, a = 10.1801(6) A, b = 10.2622(6) A, c = 23.4367(14) A, alpha = 88.313(2) degrees, beta = 86.268(2) degrees, gamma = 62.503(2) degrees, Z = 2. The crystal of 4 (C36H49B2N12TeSm.C7H8) was monoclinic, P2(1)/c, a = 18.7440(10) A, b = 10.3892(6) A, c = 23.8351(13) A, beta = 94.854(2) degrees, Z = 4. The compounds form an isoleptic series of seven-coordinate complexes with terminal chalcogenolate ligands. Examination of 1b and other crystallographically characterized lanthanide alkoxides suggests that there is little correlation between bond angle and bond length. The structures of 3a and 3b, however, contain molecules in which one of the pyrazolylborate ligands undergoes a major distortion arising from twisting around a B-N bond so as to give an effectively eight-coordinate complex with pi-stacking of the phenyl group with one pyrazolyl ring. These distortions shed light on the fluxionality of these systems.

LC and LC-MS-MS analyses of undeclared codeine in antiasthmatic Chinese proprietary medicine

This paper describes an accurate and sensitive reversed phase high-performance liquid chromatographic (RP-HPLC) method for the detection and quantification of undeclared codeine in a Chinese Proprietary Medicine (CPM) for asthma. A rapid and specific liquid chromatography-mass spectrometry-mass spectrometry (LC-MS-MS) method was applied to confirm the presence of codeine by selected reaction monitoring (SRM). Codeine was extracted from the capsules by dissolving in sodium dihydrogen phosphate buffer (10 mM, pH = 2.2) and ethanol, then made alkaline (pH = 9) and extracted using chloroform. The amount of codeine in AsthmaWan was found to be 61.8 microg/capsule (R.S.D. = 7.9%, n = 9). Excellent resolution was obtained despite the complexity of the product which claimed to contain at least nine herbal ingredients, none of which will give rise to codeine. As a further confirmation method, LC-MS-MS is accurate and specific. The LC method has been validated for linearity, limit of detection, limit of quantification, accuracy and specificity. Greater awareness of and control over undeclared drugs in complementary medicine are necessary to ensure patients' safety.

Effect of speech processor program modifications on cochlear implant recipients' threshold and maximum acceptable loudness levels

This study's purpose was to determine whether or not modifications in speech processor electrical stimulation levels were associated with changes in five Nucleus 22 cochlear implant recipients' thresholds or maximum acceptable loudness levels (MALs). These modifications in minimum and maximum stimulation levels were made to optimize hearing in everyday life. One threshold and one MAL were obtained on each active electrode during six, weekly test sessions, three before and three after program modification. Only one participant had a significant change in threshold after program modification; this participant and four others had significant changes in MAL. Participants' threshold variability was the same, but MAL variability was higher than that observed in other studies. Because these participants had no experience making MAL judgments prior to this study, this result suggests that implant recipients should be given sufficient practice in making MAL judgments to provide a stable clinical estimate of the upper boundary of the electrical dynamic range.

Changes in sarcolemmal PLC isoenzymes in postinfarct congestive heart failure: partial correction by imidapril

We have examined the changes in quantity and activity of cardiac sarcolemmal (SL) phosphoinositide-phospholipase C (PLC)-beta(1), -gamma(1), and -delta(1) in a model of congestive heart failure (CHF) secondary to large transmural myocardial infarction (MI). We also instituted a late in vivo monotherapy with imidapril, an ANG-converting enzyme (ACE) inhibitor, to test the hypothesis that its therapeutic action is associated with the functional correction of PLC isoenzymes. SL membranes were purified from the surviving left ventricle of rats in a moderate stage of CHF at 8 wk after occlusion of the left anterior descending coronary artery. SL PLC isoenzymes were examined in terms of protein mass and hydrolytic activity. CHF resulted in a striking reduction (to 6-17% of controls) of the mass and activity of gamma(1)- and delta(1)-isoforms in combination with a significant increase of both PLC beta(1) parameters. In vivo treatment with imidapril (1 mg/kg body wt, daily, initiated 4 wk after coronary occlusion) improved the contractile function and induced a partial correction of PLCs. The mass of SL phosphatidylinositol 4,5-bisphosphate and the activities of the enzymes responsible for its synthesis were significantly reduced in post-MI CHF and partially corrected by imidapril. The results indicate that profound changes in the profile of heart SL PLC-beta(1), -gamma(1), and -delta(1) occur in CHF, which could alter the complex second messenger responses of these isoforms, whereas their partial correction by imidapril may be related to the mechanism of action of this ACE inhibitor.

Transplacement mutagenesis: a novel in situ mutagenesis system using phage-plasmid recombination

Site-specific mutagenesis provides the ability to alter DNA with precision so that the function of any given gene can be more fully understood. Several methods of in vitro mutagenesis are time-consuming and imprecise, requiring the subcloning and sequencing of products. Here we describe a rapid, high fidelity method of in situ mutagenesis in bacteriophage lambda using transplacement. Using this method, mutations are transferred from oligonucleotides to target phages using a plasmid interface. A small (50 bp) homology region bearing a centred point mutation is generated from oligonucleotides and subcloned into a transplacement plasmid bearing positive and negative phage selectable markers. Following a positive/negative selection cycle of integrative recombination and excision, the point mutation is transferred precisely from plasmid to phage in a subset ( approximately 25-50%) of recombinants. As the fidelity of both oligonucleotide synthesis and phage-plasmid recombination is great, this approach is extremely reliable. Using transplacement, point mutations can be accurately deposited within large phage clones and we demonstrate the utility of this technique in the construction of gene targeting vectors in bacteriophages.