Triterpenoids from the roots of Pterospermum heterophyllum Hance.

Two new triterpenoids taraxer-14-ene-1alpha,3beta-diol (1) and 3beta-hydroxytaraxer-14-ene-1-one (2), together with the known triterpenes taraxerol (3), betulin (4), betulinic acid (5), sumaresinolic acid (6), and 5-hydroxy-2-methoxy-1,4-naphthoquinone (7), 5,7-dihydroxy-6,8-dimethylchromone (8), alpha-monpalmitin (9), palmitic acid (10), 6beta-hydroxystigmast-4-en-3-one (11), beta-sitostero1 (12), have been isolated from the petroleum ether fraction of the ethanolic extract of Pterospermum heterophyllum. Their structures were established by spectroscopic methods including IR, MS, 1D, and 2D NMR experiments. Compounds 1-8 were evaluated against several human cancer cell lines.

LYP, a novel bestatin derivative, inhibits cell growth and suppresses APN/CD13 activity in human ovarian carcinoma cells more potently than bestatin.

LYP is a bestatin dimethylaminoethyl ester which inhibits aminopeptidase N (APN/CD13). Our goal in this study was to evaluate LYP as a candidate compound for cancer treatment, beginning by studying its inhibitory effects on tumors and then comparing it to bestatin. Experiments were performed on human ovarian carcinoma (OVCA) ES-2 and SKOV-3 cell lines, which have high and low levels of APN/CD13 respectively.

Gray matter density negatively correlates with duration of heroin use in young lifetime heroin-dependent individuals.

Numerous studies have documented cognitive impairments and hypoactivity in the prefrontal and anterior cingulate cortices in drug users. However, the relationships between opiate dependence and brain structure changes in heroin users are largely unknown. In the present study, we measured the density of gray matter (DGM) with voxel-based morphometry in 30 lifetime heroin-dependent individuals who had abstained from drug use for 5 months, and 34 healthy participants.

Electrochemical formation of Mg-Li-Ca alloys by codeposition of Mg, Li and Ca from LiCl-KCl-MgCl2-CaCl2 melts.

This work presents electrochemical formation of Mg-Li-Ca alloys via codeposition of Mg, Li and Ca on a molybdenum electrode in KCl-LiCl-MgCl(2)-CaCl(2) melts at 943 K. Cyclic voltammograms (CVs) showed that the underpotential deposition (UPD) of calcium on pre-deposited magnesium leads to the formation of a liquid Mg-Ca alloy, and the succeeding underpotential deposition of lithium on pre-deposited Mg-Ca alloy leads to the formation of a liquid Mg-Li-Ca solution. Chronopotentiometric measurements indicated that the codepositon of Mg, Li and Ca occurs at current densities more negative than -0.

Remineralization of enamel subsurface lesions by chewing gum with added calcium.

Objectives: Chewing sugar-free gum has been shown to promote enamel remineralization. Manufacturers are now adding calcium to the gum in an approach to further promote enamel remineralization. The aim of this study was to compare the remineralization efficacy of four sugar-free chewing gums, two containing added calcium, utilizing a double-blind, randomized, crossover in situ model.

Photoacoustic molecular imaging with antibody-functionalized single-walled carbon nanotubes for early diagnosis of tumor.

Single-walled carbon nanotubes (SWNT) in a poly(ethylene)ghycol solution are a biocompatible transporters with strong optical absorption in the near-infrared region, in which the biological tissue is almost transparent with very low absorbance. Here, antibody-functionalized SWNTs for tumor early detection with photoacoustic molecular imaging in vivo are reported. To lay the groundwork for this goal and insure system stability, images were collected in tissue simulating phantoms to determine appropriate detectable concentrations of SWNTs.

A convenient synthesis of Type A procyanidins.

Type A procyanidins can be synthesized in good yields from the condensation of benzopyrilium salts 8 and either catechin or phloroglucinol.

[Studies on chemical constituents from roots of Pterospermum heterophyllum].

Objective: To study the chemical constituents from the roots of Pterospermum heterophyllum.

Method: The chemical constituents of P. heterophyllum were isolated and purified by silica gel and sephadex LH-20 column chromatography.

Novel mutations of the SPG11 gene in hereditary spastic paraplegia with thin corpus callosum.

Background: Hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) is a clinically and genetically heterogeneous neurodegenerative disorder with genetic linkage to multi-loci. Recently pathogenic mutations in the KIAA1840 (now named SPG11) for SPG11, the major HSP-TCC locus, were identified; at least 42 different mutations have been detected.

Objective: To study the clinical features and identify the SPG11 gene mutations in Chinese patients with HSP-TCC.

[Correlative study of carotid transient ischemic attacks and intracranial or extracranial angiostenosis].

Objective: To investigate the relationship between the clinical features of carotid transient ischemic attacks (TIA) and the intracranial or extracranial angiostenosis.

Methods: Location and degree of stenosis of involved arteries were examined by the digital subtraction angiography in 52 patients with carotid TIA.

Results: Intracranial or extracranial vascular lesions of different degrees were revealed in 45 patients (86.

[Study on molluscicidal effect of chlorosalicylicamide].

Objective: To observe the molluscicidal effect of chlorosalicylicamide on Oncomelania hupensis and toxicity on fishes.

Methods: Different concentrations of chlorosalicylicamide were prepared, and immersion and spraying methods were used to test its molluscicidal effect and toxicity to fishes. Niclosamide ethanolamine salt was used as control.

Genome-wide analysis of heat shock transcription factor families in rice and Arabidopsis.

The heat shock transcription factors (HSFs) are the major heat shock factors regulating the heat stress response. They participate in regulating the expression of heat shock proteins (HSPs), which are critical in the protection against stress damage and many other important biological processes. Study of the HSF gene family is important for understanding the mechanism by which plants respond to stress.

[Relation between acute respiratory infection and enterovirus in children in Beijing area].

Objective: To probe into the relation between acute respiratory infection and enterovirus (EV), season, age and sex of children in Beijing area.

Methods: Nasopharyngeal secretion samples from 402 inpatient children with acute respiratory infection (ARI) were obtained, and EV RNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR). The distribution of month, age and sex among the children positive for EV were analyzed.

Identification and characterization of two closely related histone H4 arginine 3 methyltransferases in Arabidopsis thaliana.

Arginine methylation of histone H3 and H4 plays important roles in transcriptional regulation in eukaryotes such as yeasts, fruitflies, nematode worms, fish and mammals; however, less is known in plants. In the present paper, we report the identification and characterization of two Arabidopsis thaliana protein arginine N-methyltransferases, AtPRMT1a and AtPRMT1b, which exhibit high homology with human PRMT1. Both AtPRMT1a and AtPRMT1b methylated histone H4, H2A, and myelin basic protein in vitro.

[Clinical observation on acupuncture combined with motortherapy for early treatment of cerebral palsy high risk infants].

Objective: To observe the effect of early treatment with acupuncture and motortherapy on developmental quotient (DQ) of cerebral palsy high risk infants.

Methods: Sixty cerebral palsy high risk infants were divided into an acupuncture combined with motortherapy group (treatment group) and a control group, 30 cases in each group. Changes of DQ were investigated by the children mental development scale.

[Preparation and functional identification of testicular Sertoli cells].

Objective: To simplify the method for separation and cultivation of rat testicular Sertoli cells with high viability, quantity and expression efficiency.

Methods: Testicular Sertoli cells from 2 to 3-week-old male Wistar rats were prepared by digestion with collagenase, trypsin and DNase and cultured together with active lymphocytes to observe their killing effect against lymphocytes. After cell culture for 72 h, the Sertoli cells were morphologically observed by different means and identified with transmission electron microscope.

The finished DNA sequence of human chromosome 12.

Human chromosome 12 contains more than 1,400 coding genes and 487 loci that have been directly implicated in human disease. The q arm of chromosome 12 contains one of the largest blocks of linkage disequilibrium found in the human genome. Here we present the finished sequence of human chromosome 12, which has been finished to high quality and spans approximately 132 megabases, representing approximately 4.

Effective asymmetric epoxidation of styrenes by chiral dioxirane.

High enantioselectivity (80-92% enantiomeric excess (ee)) has been obtained for the epoxidation of various styrenes using an easily prepared ketone (4) catalyst.

Transmission control of schistosomiasis japonica: implementation and evaluation of different snail control interventions.

The great progress made in the control of schistosomiasis japonica in China is to some extent explained by successful intermediate host snail control, in particular with environmental management commencing some 50 years ago. By 1995, interruption of Schistosoma japonicum transmission had been achieved in five of the 12 schistosome-endemic provinces while endemic areas in the remaining provinces had been reduced significantly, and snail habitats had decreased by 74%. In this paper, we review the role and approaches towards control and give an account of compounds toxic to snails.

Voltammetric detection of heparin at polarized blood plasma/1,2-dichloroethane interfaces.

Heparin, a highly negatively charged polysaccharide, which has been used widely as an anticoagulant and antithrombotic, was detected by ion-transfer voltammetry at the interface between 1,2-dichloroethane and an aqueous buffer solution or undiluted blood plasma. Quaternary ammoniums with different numbers of methyl and long alkyl groups were examined as positively charged heparin ionophores using pipet electrodes filled with the organic electrolyte solutions of their tetrakis(4-chlorophenyl)borate salts. It was shown that octadecyltrimethylammonium most selectively facilitates interfacial heparin adsorption without interference from potential-dependent ionophore transfer into the aqueous phase.

Facilitated protamine transfer at polarized water/1,2-dichloroethane interfaces studied by cyclic voltammetry and chronoamperometry at micropipet electrodes.

Cyclic voltammetry and chronoamperometry at micropipet electrodes were applied to study the phase transfer of polypeptide protamine facilitated by complexation with charged ionophore dinonylnaphthalenesulfonate (DNNS) at polarized water/1,2-dichloroethane (DCE) interfaces, i.e., sDNNS(-) (DCE) + protamine(n+) (aq) right harpoon over left harpoon protamine-DNNS complex (DCE).

Chronoamperometry at micropipet electrodes for determination of diffusion coefficients and transferred charges at liquid/liquid interfaces.

Chronoamperometry was carried out at liquid/liquid interfaces supported at the tip of micropipet electrodes for direct determination of the diffusion coefficient of a species in the outer solution. The diffusion coefficient was used for subsequent determination of the transferred charges per species from the diffusion-limited steady-state current. A large tip resistance of the micropipets causes prolonged charging current so that the faradic current can be measured accurately only at a long-time regime (typically t > 5 ms).

[Study on the attenuation of graft versus host disease by methoxy polyethylene glycol modification of donor lymphocytes].

Aim: To find out why mPEG modification of donor's lymphocytes can attenuate the occurrence of graft versus host disease(GVHD), but not affect the hemopoietic reconstitution of stem/progenitor cells after transplanting the mPEG-modified mononuclear cells from human cord blood into the SCID mice.

Methods: The followings were observed: (1) Changes of CD4(+) and CD8(+) T cells and the ratio of CD4(+)/CD8(+) T cells were examined by flow cytometry before and after mononuclear cells from human cord blood were modified with mPEG. (2) The difference in forming the CFU-GM in-vitro between the mPEG modified-stem/progenitor cell group and non-modified cell group was observed.

[Clinical characteristics of bronchiolitis caused by human metapneumovirus in infants].

Objective: The fact that the acute lower respiratory infections (ALRI) are associated with a newly discovered virus, human metapneumovirus (hMPV), has been shown in several studies. The authors conducted this study to understand the etiological and clinical characteristics of bronchiolitis, one of the most common ALRI in infants, caused by hMPV.

Methods: Nasopharyngeal aspirate specimens from 54 out of 126 infants with bronchiolitis admitted to the Children's Hospital Affiliated to Capital Institute of Pediatrics, Beijing from November 2002 to February 2003 were examined for hMPV gene fragments by reverse transcription-polymerase chain reaction (RT-PCR).