Biomedical subjects
Publications and source records attributed to X Xu.
Resource investigation and commodity identification were carried out for 28 samples of Fructus Amomi collected from 7 provinces. The results showed that Fructus Amomi used currently were mainly from the dried ripe-fruit of Amomum villosum, A. villosum var. xanthioides or A. longiligulare. Fructus Amomi in market is nainly A. villosum which comes from Yunnan and Guangdong province.
OBJECTIVE: Most frequent molecular lesions of alpha-thalassemia-2 determinants are deletions of one alpha-globin gene. Satisfactory PCR methodologies for detecting the deletions are required for molecular diagnosis and genetic screening since there was no internal control in most published PCR-based strategies. The purpose of this study is to develop a reliable PCR protocol specific for the two common alpha-thalassemia-2 determinants with internal control. METHODS: The multiple repeat elements and the high GC-content of the alpha-globin locus impose severe limitations on designing suitable primers and optimizing stable conditions for PCR. In this study, two multiplex PCR systems were successfully set up. One was designed to detect the rightward deletion (-alpha(3.7)/) with two pairs of primers including one newly optimized pair for amplification of the internal standard to indicate the success of failure of PCR amplification. The other, to the leftward deletion(-alpha(4.2)/) with three primers, which were designed according to the newly sequenced data of the -alpha(4.2) and HbQ-alpha(4.2) deletions in this lab(Genbank Accession No. AF221717). In the PCR system, one is used as a common upstream primer and the other two are used as specific downstream primers for typing the normal allele and the deletion one, respectively. RESULTS: Easily interpretable, unambiguous amplifications were observed by using the multiplex PCR systems for the detection of the two common alpha-thalassemia-2 determinants. The three or four primers were run in the same tube under the same condition and both of these two systems could be used at the same thermal cycle parameters. For typing the rightward deletion, a mutant-specific amplification of 1.7 kb and a 1140 bp amplified band as a normal and system control were produced. For typing the leftward deletion, two PCR-amplified bands, a 956 bp fragment specific for a -alpha(4.2) gene and a 1140 bp one for a normal allele were found. CONCLUSION: Two sets of PCR systems with internal controls for detecting the most common two alpha-thalassemia-2 determinants have been established and may be suitable for molecular diagnosis and population screening.
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OBJECTIVE: To study the preventive effect of Xin-Kang oral liquid on acute Coxsackie B3 viral myocarditis in mice. METHODS: The mice were infected Coxsackie virus B3 (CVB3m) through abdominal cavity after they were fed with the Xin-Kang oral liquid for 2d, and the uses of the drug continued to the 20th day. Histopathological changes of the myocardial cells were observed under microscope and measured by morphometric quantification. RESULTS: The detection rate of pathological change of grade III of heart surface in Xin-Kang oral liquid groups were lower than in virus control group, the difference between Xin-Kang medium dose group and virus control group being specially significant (P < 0.01), and the detection rate of severe myocardial damage was much lower. The average area of myocardial damage and area of myocardial damage/area of the whole heart in Xin-Kang oral liquid groups were markedly lower than those in virus control at the 5th day and the 20th day. CONCLUSION: These results demonstrate that the preventive effect of Xin-Kang oral liquid on acute Coxsackie B3 viral myocarditis is similar to that of interferon.
OBJECTIVE: To investigate the relationship between genotype and phenotype of a deletional delta beta-thalassemia and explore an approach to rapid prenatal diagnosis for compound heterozygotes of this defect and a beta-thalassemia. METHODS: A total of ten members in a Chinese family who had a 5-year-old propositus with thalassemia major and requested prenatal diagnosis for the second pregnancy were investigated. For genotyping analysis, the deletional delta beta-thalassemia was characterized by gap-PCR method and beta-thalassemia mutations were defined by reverse dot blot(RDB). For phenotyping analysis, hematological data including the RBC indices, quantification of HbF and HbA2 by Hb electrophoresis and the ratio of globin chain Ggamma/(Ggamma+Agamma) analyzed by capillary electrophoresis (CE) were obtained. RESULTS: The propositus inherited her mother's delta beta-thalassemia gene mutation and her father's CD41-42(-CTTT) frameshift mutation. Of nine members in this family screened for this type of deletion, four were positive and the phenotype could be explained satisfactorily by genotype. The results of prenatal diagnosis showed that the fetus was normal and had no beta-globin gene defects in both chromosomes. CONCLUSION: This is the first time to have performed prenatal diagnosis in Chinese family at-risk of compound heterozygotes for beta-thalassemia and delta beta-thalassemia in mailand China. The strategy to analyze the disease presented here may be a valuable reference to the similar problem.
Palladium-catalyzed Heck condensation of C-p-bromophenyl delta2-glycopyranoside with methyl vinyl ketone, methyl acrylate, acrylonitrile, or N-acetyldehydroalanine methyl ester occurred in quite good yields (60-82%).
The granulation of PCP degrading anaerobic sludge in two improved UASB reactors under co-existence of two types of industrial wastewater and PCP were studied. It was found that the granulation of PCP degrading anaerobic sludge could be divided into three stages, i.e. sludge acclimation, granular pre-formation and granular maturation. The changes in biomass, sludge bioactivity, population and ecological distribution of three group bacteria involved in anaerobic digestion during the course of granulation were also examined. Anaerobic granules from two reactors showed high dechlorination activity at meta, otho and para position. Rod-shaped and filamentous shaped Methanosaeta-like spp. were found in anaerobic granules. Results of electron microscopy revealed the presence of synthophic microcolonies and non-layed microstructure in PCP-degrading granules. The types of industrial wastewater used as co-substrate had affected the course of sludge granulation, dechlorinating activity and pre-dominant methanogens in PCP-degrading anaerobic granules.
PCDDs-degrading bacterial strains were isolated from soil and oxic-sediments polluted by PCDDs. One of them was identified as Pseudomonas sp. EE41. They are capable of growing on and degrade mono- and di-chlorinated dibenzo-p-dioxins as a sole carbon source. The biodegradability of TrCDD and TCDD can be enhanced through primary nutrient of co-metabolism of o-CDB, thus, 1,2,3-TrCDD and 2,3,7,8-TCDD were degraded by 33% (at the concentration of 1.2 mg/L, within 3 weeks) and 37.8% (at the concentration of 0.1 mg/L, within 3 weeks) respectively. Most highly chlorinated dibenzo-p-dioxins (P-CDD, H6-, H7-CDD and OCDD) tested in this study were accumulated in bacterial cells, but could not be degraded.
BACKGROUND: The National Institutes of Health Consensus Panel on Acupuncture has listed as a priority the study comparing indications and patterns of use of acupuncture in different countries. METHODS: I visited an outpatient acupuncture clinic in China and reviewed the clinical files. A MEDLINE search was done to compare the use of acupuncture in North America and China. RESULTS: The most common disorder treated in the clinic was musculoskeletal pain. Less common indications included stroke rehabilitation, Bell's palsy, cholelithiasis, tinnitus, insomnia, migraine, and visceral pain. In North America, acupuncture is primarily for pain relief. Other uses include stroke rehabilitation, various emetic problems, migraine, and various addictions. CONCLUSIONS: Acupuncture is most frequently used in China and North America for pain relief. Other common indications include peripheral nerve palsy, peripheral nerve neuralgia, stroke rehabilitation, psychoemotional disorders, migraine, visceral pain, emesis, asthma, and tinnitus. Acupuncture for cholelithiasis in China but not in the United States suggests a novel use of this modality.
The development and certification of a coal fly ash certified reference material (CRM) for polycyclic aromatic hydrocarbons (PAH) is described; this is the first natural matrix CRM for organic environmental analysis in China. The homogeneity and stability of this material have been tested by HPLC. The concentrations of several PAH were determined by use of two independent, different methods--solvent extraction-HPLC analysis with UV detection coupled with fluorescence detection (FLD) and solvent extraction, isolation with a silica column, and GC analysis with flame ionization detection (FID). Five certified values were determined: phenanthrene 7.1 +/- 2.6 microg g(-1), anthracene 2.0 +/- 0.8 microg g(-1), fluoranthene 7.4 +/- 1.9 microg g(-1), pyrene 7 +/- 2 microg g(-1), and benzo[a]pyrene 1.3 +/- 0.3 microg g(-1). Reference values for several other PAH are also suggested.
Solution culture experiments with Zn-inefficient cultivar (IR26) and the Zn-efficient cultivar (IR8192-31-2) were conducted to study the effect of HCO3- on the root growth and nutrient absorption of different rice cultivars. The results showed that HCO3- strongly inhibited the root growth of Zn-inefficient cultivar especially at low Zn concentration. In contrast, that of Zn-efficient cultivar was slightly stimulated by HCO3- at low Zn concentration. HCO3- not only inhibited Zn absorption of Zn-inefficient cultivar, but also inhibited its absorption of Fe, Mn, Cu, implying that there was no specific inhibition of HCO3- on Zn absorption. These results demonstrated that the inhibition of root growth by HCO3- was likely to be the initial action of HCO3- in inducing Zn deficiency in lowland rice. With treatment of bicarbonate, Zn concentrations in upper and lower leaves of the Zn-efficient cultivar and their ratios were higher than those of the Zn-inefficient cultivar. The results showed that the Zn-efficient cultivar could transport more zinc from lower leaves to upper leaves, which might be-one of mechanisms that the Zn-efficient cultivar adapted to zinc deficiency in calcareous soil.
The performances of soil-slurry process with supplement of anaerobic granular sludge for remediating PCP-contaminated soil was investigated. The results showed that inherent anaerobic microbes in soil exhibited a little dechlorinating activity for simulative contaminated soil with 30 mg.kg-1 of PCP, the average PCP degradation rates within 28 d was 0.258 mg.kg-1.d-1. In soil slurry processes with 5 g.kg-1 granular sludge at aerobic, aerobic/anaerobic and anaerobic operation, the average PCP degradation rates within 28 d were 0.269, 0.291/0.842 and 0.892 mg.kg-1.d-1, respectively. PCP degradation rates were increased with increasing the amounts of anaerobic granular sludge, 0.834, 0.843, 0.928 mg.kg-1.d-1 of the average PCP degradation rates within 35 d were achieved in soil slurry processes supplemented with 5, 10, 25 g.kg-1 of granular sludge, respectively. This bioremediation process also presented higher initial PCP degradation rate for higher concentration(60 mg.kg-1) of PCP in soil.
OBJECTIVE: To study the association of Alzheimer disease (AD) with apolipoprotein E (ApoE) epsilon 4 allele and to find the biological peripheral markers for the laboratory diagnosis of AD. METHODS: 107 patients with AD, 68 patients with vascular dementia (VD) and 74 sex- and age-matched non-demented healthy individuals (NDC) were collected. DNA from patients and healthy individuals was extracted from peripheral blood samples with the phenol-chloroform procedure and ApoE was investigated with the methods of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULTS: The frequency of epsilon 4 was significantly higher in AD than that in VD and NDC and there was no difference in the frequency of epsilon 4 between VD and NDC. The age at onset of the disease in the group carrying two epsilon 4 alleles was significantly younger than that in the group with one epsilon 4 allele in AD. Moreover, in comparison with AD patients without epsilon 4 allele, the age at onset in the group with one epsilon 4 allele was younger. Patients with epsilon 4 or without epsilon 4 allele in VD patients did not differ significantly in age at onset. Meanwhile, 3 familial AD cases were found, all carrying epsilon 4 allele. CONCLUSION: AD and ApoE4 were closely related. ApoE epsilon 4 was a dangerous factor of AD and ApoE 4 allele made contribution to the heterogenicity of AD.
OBJECTIVE: To evaluate the effect of community intervention for COPD and chronic cor-pulmonale. METHODS: The baseline survey of the study was carried out in 1992. The total population was randomly divided into intervention and control regions. From 1992 the comprehensive community intervention trial was conducted in the intervention region. The data of baseline study has been published elsewhere. The family inquiry was made in all baseline population, 50 percent of high risk population and 100 percent of COPD and cor pulmonale population were reexamined. RESULTS: Of the 3,739 subjects who should be investigated 3,316 subjects were really investigated (88.7% of responsive rate). Of 814 subjects randomly abstracted from 3,316 in intervention and control regions, the awareness rates of smoking harm to health were 95.0% and 80.0%, of how to prevent and treat COPD were 62.0% and 35.7%, of regular visit by doctors were 46.1% and 27.0% respectively. The rate of ex-smoker was 28.2% in intervention region more than that of 23% in control region (P = 0.004). Of 3,075 subjects undergone lung function test, FEV1 decrements per capita yearly were 32.0 ml and 37.9 ml (P = 0.001); FVC decrement were 42.0 ml and 48.3 ml (P = 0.012) in intervention and control regions. The prevalence increment in COPD were 5.6% and 8.0% (P = 0.03), cor-pulmonale were 3.5% and 6.7% (P = 0.02) compared to baseline survey in both regions. The mortality of cor-pulmonale were 72.9 and 95 per 100,000 per year (P = 0.0044) from 1995 to 1999. CONCLUSION: The rate of quiting smoke is significantly increased by intervention. The declination of lung function significantly decreases. The increment in prevalence of COPD and cor-pulmonale significantly decreases. The mortality of cor-pulmonale decreases significantly in intervention region. The results indicates that the comprehensive intervention in community is an important measurement for decreasing incidence of COPD and mortality of cor-pulmonale.
OBJECTIVE: To assess the effectiveness of artificial liver support system (ALSS) treatment in patients with hepatic failure. METHODS: 235 cases of hepatic failure were treated with ALSS in our hospital. All data were analyzed by SPSS. The effectiveness of ALSS treatment was compared according to different stages (i.e., early, middle and end stages). RESULTS: 108 patients survived after therapy of ALSS. After each ALSS treatment, the liver function of these patients was greatly improved, the serum endotoxin and HBV-DNA concentrations were significantly decreased, and the serum concentration of aromatic amino acids (AAA) such as methionine decreased while the ratio of branched chain amino acids and aromatic amino acids (BCAA/AAA ratio) increased; patients treated with ALSS in the early or middle stages of disease had much higher survival rates than patients in the end stage of disease. CONCLUSION: ALSS is a reliable therapy for advanced liver diseases and treatment at early or middle stages is appropriate.
OBJECTIVE: To observe engraftment kinetics, the incidence and severity of graft-versus-host disease (GVHD), and clinical outcome on 40 recipients undergoing allogeneic peripheral blood stem cell transplantation (allo-PBSCT). METHODS: From June 1997 to May 1999, forty leukemia patients with a median age of 35 years underwent allo-PBSCT. PBSC were mobilized with G-CSF at a dose of 5 micrograms/kg s.c. every 12 hours for 5 days. A median of 7.7 (2.0-16.8) x 10(6) CD34+ cells/kg was infused into the recipients. Busulfan-cyclophosphamide (BU-CY) was used as the conditioning regimen. All patients received cyclosporine A and either methotrexate (n = 34) or methylprednisolone (n = 6) for GVHD prophylaxis. RESULTS: Engraftment of neutrophils and platelets was achieved at a median of 13 days (9-28 days) and 12 days (7-60 days) respectively. Patients receiving > or = 4 x 10(6) CD34+ cells/kg or given G-CSF post transplant had significantly accelerated neutrophil and platelet engraftment. Acute GVHD occurred in 17 of 40 patients (42.5%), with grade II-IV acute GVHD in 10 patients (25%). Chronic GVHD developed in 21 (9 extensive, 12 limited) out of 30 evaluable patients (21/30, 70%) with a median follow up of 380 days (180-900 days). Transplant related mortality was 17.5% and the relapse rate was 10%. The probability of leukemia free survival at 3 years was 72.5%. CONCLUSION: Allo-PBSCT can provide rapid hematopoietic reconstitution without an increased incidence of acute GVHD, but may be associated with a high risk of chronic GVHD.
OBJECTIVE: To construct a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma (HCC) tissue. METHODS: Using the suppression subtractive hybridization (SSH), a novel technique has been described recently. cDNA fragments of missing or low expressing tumor suppressor genes in HCC tissue were isolated using paracancerous normal liver tissue and HCC tissue as targets. Then these cDNA fragments were directly inserted into T/A cloning vector to set up the subtractive library. Amplification of the library was carried out with transformation of E.coli by high voltage electroperforation. One hundred positive bacteria clones were randomly picked and identified using enzyme restriction method. RESULTS: The amplified library contained more than 4,000 positive bacteria clones. Random analysis of 100 clones with enzyme restriction method showed that all clones contained 200-600 bp inserts. CONCLUSIONS: A subtracted cDNA library of differentially expressed genes in human normal liver tissue and HCC tissue is constructed successfully with SSH and T/A cloning techniques. The library is efficient and lays solid foundation for screening and cloning new and specific missing or low expressing tumor suppressor genes of HCC.
In this article, a new approach is introduced to lowering the myo-electronic noise in weak ECG signals. We use artificial neural network to make the noise be white, and then we adopt an adaptive filter of which the reference signal is achieved by extracting from other ECG cycle. The outcome is the reduction of both white noise and non-white noise in ECG signal. Satisfactory results have been achieved by using this method in the experiment of late potential detection.