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Biomedical subjects

L Ming

Publications and source records attributed to L Ming.

At least 19 recordsLinked to original sources
PubMed2001

Mutations in a newly identified GTPase gene cause autosomal dominant hereditary spastic paraplegia.

The hereditary spastic paraplegias (HSPs; Strümpell-Lorrain syndrome, MIM number 18260) are a diverse class of disorders characterized by insidiously progressive lower-extremity spastic weakness (reviewed in refs. 1-3). Eight autosomal dominant HSP (ADHSP) loci have been identified, the most frequent of which is that linked to the SPG4 locus on chromosome 2p22 (found in approximately 42%), followed by that linked to the SPG3A locus on chromosome 14q11-q21 (in approximately 9%). Only SPG4 has been identified as a causative gene in ADHSP. Its protein (spastin) is predicted to participate in the assembly or function of nuclear protein complexes. Here we report the identification of mutations in a newly identified GTPase gene, SPG3A, in ADHSP affected individuals.

Amino Acid Sequence↗
PubMed2000

[Protective effect of extract of folium ginkgo on repeated cerebral ischemia-reperfusion injury].

OBJECTIVE: To study the protective effect of extract of Folium Ginkgo (FGE) on repeated cerebral ischemia-reperfusion injury. METHODS: The model in waking mice induced by repeated cerebral ischemia-reperfusion were used in the experiment to observe the effect of FGE on behavior, oxygen free radical metabolism and prostaglandin E2 (PGE2) content by step-through experiment, diving stand and colorimetric method. RESULTS: FGE could obviously improve the learning ability and memory of model animals, and could lower obviously the content of malonyldialdehyde, nitric oxide and PGE2, restore the lowered activity of superoxide dismutase and catalase in cerebral tissue. CONCLUSION: FGE has highly protective effect against repeated ischemia-reperfusion injury, the mechanism might be related with its action on anti-lipid oxidatin, improve the activity of antioxidase and inhibit the producing of PGE2.

Animals↗
PubMed1999

Increased risk of hepatocellular carcinoma in male hepatitis B surface antigen carriers with chronic hepatitis who have detectable urinary aflatoxin metabolite M1.

We followed 145 men with chronic hepatitis B virus (HBV) hepatitis for 10 years to determine whether exposure to aflatoxin, or concomitant exposure to hepatitis C virus (HCV), or family history of hepatocellular carcinoma (HCC) increased the risk of developing HCC. We collected 8 monthly urine samples before beginning follow-up and pooled them to detect aflatoxin metabolite M1 (AFM1). AFM1 was detected in 78 (54%) of the subjects. The risk of HCC was increased 3.3-fold (with a 95% confidence interval of 1.2-8.7) in those with detectable AFM1 (above 3.6 ng/L). This relative risk was adjusted for age and for HCV status. The attributable risk from exposure to detectable AFM1 was 0.553 (0.087, 0.94). The relative risk of fatal cirrhosis for those with elevated AFM1 was 2.8 (0.6, 14.3), and the odds of having a persistently elevated alanine transaminase (ALT) were 2.5-fold greater in those with detectable AFM1 (P =.007). Concomitant infection with HCV increased the risk of HCC 5.8-fold (2. 0-17), adjusted for age and AFM1 status. A family history of HCC increased the risk of HCC 5.6-fold, adjusted for age and AFM1. Four men with detectable AFM1 and HCC all had missense mutation in codon 249 of the p53 gene in cancer tissues. This study shows that exposure to AFM1 can account for a substantial part of the risk of HCC in men with chronic HBV hepatitis and adds importantly to the evidence that HCV and family history of HCC increase the risk of HCC in men with chronic HBV hepatitis.

Adolescent↗
PubMed1999

Pulmonary function for pectus excavatum at long-term follow-up.

PURPOSE: The aim of this article was to assess whether and to what extent pulmonary function recovered to normal degree postoperatively and to investigate the changes in pulmonary function after surgical correction and the value of surgical correction. METHODS: A total of 27 patients who could be questioned and examined in person at the outpatient department of our hospital were included in this study. Of these patents, 24 were boys and 3 were girls. Their ages ranged from 3 to 16 years (mean, 8.67) at follow-up. The mean age at surgery was 4 years, and mean years of follow-up was 6.8. Pulmonary functional measurements included in vital capacity (VC), total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), RV-TLC ratio, maximal voluntary ventilation (MVV), force ventilatory capacity (FVC), forced expiratory volume in one second (FEV1), maximal midexpiratory flow curve (MMEF), maximal expiratory flow in 75% vital capacity (V75), maximal expiratory flow in 50% vital capacity (V50), maximal expiratory flow in 25% vital capacity (V25), and breathing reserve ratio (BR). RESULTS: TLC, FRC, MVV, MMEF, V75, and V50 values were not different from the normal values. IVC, FVC, FEV1, and V25 values were decreased significantly compared with the normal values. The RV and RV-TLC were high in 87.5% cases. CONCLUSIONS: Preoperative symptoms obviously improved after operation. There was little airway obstruction in the patients postoperatively. The patients with pectus excavatum should be operated on as soon as possible.

Adolescent↗
PubMed1999

Tumor necrosis factor-alpha-activated cell death pathways in NIT-1 insulinoma cells and primary pancreatic beta cells.

Tumor necrosis factor-alpha (TNFalpha) is a potential mediator of beta cell destruction in insulin-dependent diabetes mellitus. We have studied TNF-responsive pathways leading to apoptosis in beta cells. Primary beta cells express low levels of the type I TNF receptor (TNFR1) but do not express the type 2 receptor (TNFR2). Evidence for TNFR1 expression on beta cells came from flow cytometry using monoclonal antibodies specific for TNFR1 and TNFR2 and from RT-PCR of beta cell RNA. NIT-1 insulinoma cells similarly expressed TNFR1 (at higher levels than primary beta cells) as detected by flow cytometry and radio-binding studies. TNF induced NF-kappaB activation in both primary islet cells and NIT-1 cells. Apoptosis in response to TNFalpha was observed in NIT-1 cells whereas apoptosis of primary beta cells required both TNFalpha and interferon-gamma (IFNgamma). Apoptosis could be prevented in NIT-1 cells by expression of dominant negative Fas-associating protein with death domain (dnFADD). Apoptosis in NIT-1 cells was increased by coincubation with IFNgamma, which also increased caspase 1 expression. These data show that TNF-activated pathways capable of inducing apoptotic cell death are present in beta cells. Caspase activation is the dominant pathway of TNF-induced cell death in NIT-1 cells and may be an important mechanism of beta cell damage in insulin-dependent diabetes mellitus.

Animals↗
PubMed1999

[Characteristics of high frequency 249 codon mutation of p53 gene in hepatocellular carcinoma in prevalent area of China].

OBJECTIVE: To study the characteristic features of an unique hotspot missense mutation of the 249 codon of p53 gene demonstrated in human hepato-cellular carcinoma(HCC) in a region of high(Qidong) and low (Beijing) exposure to both hepatitis B virus (HBV) and aflatoxin B1 (AFB1) in China. METHODS: Surgical samples from 97 HCC from Qidong and 22 from Beijing, China, collected in 1994 through 1997, were studied. The 249 codon mutation of p53 gene was detected by PCR followed by HaeIII RFLP analysis and DNA sequencing. Intracellular p53 protein level was determined by immunohistochemical staining. RESULTS: High mutation rate of 249 codon of p53 gene was consistently found in recent years, with an average of 53.6% (52/97). No such mutation was identified in 22 Beijing HCC collected in the same time period. The genotype of p53 249 codon mutants which showed heterozygous profile was identified to be homozygous in nature following tumor tissue enrichment. Of 21 HCC shown to have 249 codon mutation, 20 exhibited high intranuclear accumulation of p53 protein. p53 protein staining was negative in the surrounding noncancerous hepatic tissue. CONCLUSION: The high frequency of homozygous mutation of the 249 codon of p53 gene accompanied with p53 protein accumulation provides important enlightenment in the understanding of hepatocarcinogenesis and clinical application of gene therapy and/or immunotherapy for HCC.

Carcinoma, Hepatocellular↗
PubMed1998

Synthesis and anticholinesterase activity of huperzine A analogues containing phenol and catechol replacements for the pyridone ring.

Based upon modeling results obtained using the crystal structure of huperzine A in complex with acetylcholinesterase (AChE), two novel analogues of this potent AChE inhibitor were designed with phenol or catechol rings replacing the pyridone ring. From the modeling studies, the catechol analogue appeared capable of replacing one of the crystallographic waters bridging huperzine with Tyr 130 and Glu 199 of AChE. The synthesis of these materials by use of a palladium catalyzed bicycloannulation strategy is detailed together with the results of AChE inhibition assays.

Alkaloids↗
PubMed1997

Fertilization-independent seed development in Arabidopsis thaliana.

We report mutants in Arabidopsis thaliana (fertilization-independent seed:fis) in which certain processes of seed development are uncoupled from the double fertilization event that occurs after pollination. These mutants were isolated as ethyl methanesulfonate-induced pseudo-revertants of the pistillata phenotype. Although the pistillata (pi) mutant has short siliques devoid of seed, the fis mutants in the pi background have long siliques containing developing seeds, even though the flowers remain free of pollen. The three fis mutations map to loci on three different chromosomes. In fis1 and fis2 seeds, the autonomous endosperm nuclei are diploid and the endosperm develops to the point of cellularization; the partially developed seeds then atrophy. In these two mutants, proembryos are formed in a low proportion of seeds and do not develop beyond the globular stage. When FIS/fis plants are pollinated by pollen from FIS/FIS plants, approximately 50% of the resulting seeds contain fully developed embryos; these seeds germinate and form viable seedlings (FIS/FIS). The other 50% of seeds shrivel and do not germinate; they contain embryos arrested at the torpedo stage (FIS/fis). In normal sexual reproduction, the products of the FIS genes are likely to play important regulatory roles in the development of seed after fertilization.

Arabidopsis↗
PubMed1997

Infection with human immunodeficiency virus and hepatitis viruses in Chinese drug addicts.

The prevalence of antibody against hepatitis C virus (anti-HCV) and five hepatitis B virus markers (HBVM) was measured in 176 Chinese drug addicts, of whom 23 were AIDS patients. Of 176 drug addicts, 147 were members of ethnic minorities while 29 were Han, the majority ethnic group. The total prevalence rates of anti-HCV and HBVM were 35.8% and 50.6% respectively, significantly different (P < 0.01). Anti-HCV and HBVM were together found in 22.7%. Similar prevalence rates were found among the different ethnic groups. Among the ethnic minorities, there was a significantly higher prevalence rate of anti-HCV in intravenous drug addicts (IVDA, 51.1%) than in oral drug addicts (20.3%). Furthermore, the prevalence of anti-HCV was significantly higher in needle-sharing abusers (60.4%) than in non-needle sharing ones (37.1%, P < 0.05). The prevalence of HBVM was also significantly higher in needle-sharing abusers (69.8%) than in non-needle sharing ones (34.3%). Prevalence of HBsAg was significantly higher in drug abusers with AIDS (47.8%) than in IVDA only (16.1%). The anti-HCV positive rates among ethnic minority people were: for the Yi people 69.2%, the Hui 55.6%, the Bai 53.9%, the Dai 26.8% and the Wa 23.1%. No obvious difference was identified for HBVM. The prevalence rates of HCV, HBV and HCV + HBV in IVDA showed no significant difference (P > 0.05) between the two regions. HIV, HCV and HBV infections may promote each other and be related to needle-sharing behaviour in drug abuse and to different subcultures and living habits.

Adolescent↗
PubMed1995

Moldy sugarcane poisoning--a case report with a brief review.

A five-year-old girl developed an acute encephalopathy after eating a piece of moldy sugarcane. Delayed symptomatic dystonia was the main effect; cranial CT scans revealed bilateral lenticular lucencies. This case is typical of moldy sugarcane poisoning cases previously reported only in China. 3-Nitropropionic acid produced by Arthrinium sp is the most likely etiologic agent.

Carbohydrates↗
PubMed1995

Chemical modification of tylosin.

20-Homo tylosin, 20-nor tylosin, 20-deoxy-19,20-didehydro tylosin (6-vinyl tylosin) and 2",3"-didehydro-3"-deoxy tylosin were prepared by multi-step procedures. 20-Homo tylosin was about twice less active than tylosin while the other compounds exhibited very weak antibacterial activity.

Anti-Bacterial Agents↗
PubMed1993

ABO blood grouping on dental tissue.

Twenty-five permanent teeth, including eight carious ones whose pulp cavities had been exposed, were used for this research 3-5 weeks after extraction. Phosphate-buffered saline (PBS, at pH 7.2) was employed to extract ABO blood group substance from tooth powder. ABO grouping was performed on blood-stained compresses from the extraction wound (as controls), tooth fragment, tooth powder, and cotton fibers immersed in PBS extract by absorption-elution (AE) technique and on the PBS extracts by the two-dimensional absorption-inhibition (2-D AI) technique. It was found that blood grouping in PBS extracts by 2-D AI yielded reliable results: no false positive results, and a high rate of correct grouping, (24/25), while blood grouping on other dental materials, such as tooth fragments, tooth powders, immersed fibers, by AE gave an unacceptable rate of false positive/negative results.

ABO Blood-Group System↗
PubMed1991

The association between cervical carcinoma and human papilloma virus (HPV) in Xiangyuan County.

A mass survey was conducted to investigate the association between cervical carcinoma and human papilloma virus (HPV) infection in a high-risk area, Xiangyuan County, Shanxi Province. Fifty-four cases of cervical cancer in situ (CIS), including severe dysplasia (CIN III), 14 cases of invasive cervical carcinoma, 28 cases of mild cervical dysplasia (CIN I), and 13 cases of moderate cervical dysplasia (CIN II) were identified among 6710 women examined. One hundred and sixty-nine punch biopsies from abnormal cervix and genital tract were examined for the presence of HPV 6B/11, 16 and 18 DNA sequences by dot blot hybridization: The positive rates of HPV infection in cervicitis, CIN I, II, III, CIS and invasive cervical carcinoma specimens were 35.06% (27/77), 25% (2/8), 33.33% (2/6), 40% (2/5), 70.58% (24/34) and 40% (4/10), respectively. Among these groups, there was no regular distribution of HPV types except for HPV 16, the positive rate of which was increased from 25% in CIN I to 46.15% in CIS: HPV 16 was also the only type seen in the invasive cervical cancer group. Distribution analysis of HPV types in HPV-positive cervical cancer tissues uncovered an HPV 16 positive rate of 59.4%; 3.7 and 2.4 times higher than those of HPV 6B/11 and HPV 18, respectively. These data confirm the close association between cervical cancer and HPV 16 infection.

Adult↗
PubMed1990

Adrenocorticotrophin-induced hypertension in the rat: haemodynamic, metabolic and morphological characteristics.

Adrenocorticotrophin (ACTH) administration has been systematically studied in man and sheep. It raises systolic blood pressure (SBP) in the rat, but this has been little studied. ACTH was injected once daily at 0.5 mg/kg for 12 days in male Sprague-Dawley rats (n = 19). Sham-injected animals were studied in parallel (n = 15). ACTH increased SBP from 94 +/- 4 to 121 +/- 4 mmHg (P less than 0.001), significantly greater (P less than 0.02) than sham injection. The SBP of ACTH-treated rats was significantly higher than that of sham-injected rats when the same animals were measured by both the tail-cuff method (ACTH, 126 +/- 3 mmHg; sham, 99 +/- 3 mmHg) and direct arterial cannulation (ACTH, 137 +/- 2 mmHg; sham, 123 +/- 3 mmHg): P less than 0.005 and P less than 0.001, respectively. There was a loss of body weight, and increased water intake and urine output in ACTH-treated animals compared with both control (P less than 0.001) and sham treatments (P less than 0.02). ACTH increased plasma [Na] (sham, 140 +/- 1 mmol/l; ACTH, 145 +/- 1 mmol/l; P less than 0.001) and urinary Na excretion compared with control (P less than 0.01) and sham injection (P less than 0.05), and also decreased plasma [K] (sham, 4.6 +/- 0.2 mmol/l; ACTH, 3.3 +/- 0.8 mmol/l; P less than 0.01) and increased urinary K excretion (P less than 0.01) compared with control. SBP in adrenalectomized animals (n = 10) was unchanged by ACTH. ACTH increased adrenal, renal, cardiac and brain weights compared with sham injection (P less than 0.05). There were no significant changes in vascular morphology, although ACTH treatment increased glomerular epithelial cell droplets and abolished the adrenal zona glomerulosa.

Adrenal Glands↗