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Biomedical subjects

Y Ma

Publications and source records attributed to Y Ma.

At least 379 records · Page 21Linked to original sources
PubMed1997

[Sequence alterations in p53 gene of hepatocellular carcinoma from high aflatoxin risk area in Guangxi].

OBJECTIVE: Check on the sequence alterations of the p53 gene of hepatocellular carcinoma (HCC) in some areas of Guangxi. METHODS: 40 cases of archival HCC samples were divided into two groups. One includes 26 cases from Fusui--an area notorious for high risk in HCC, AFB1 and HBV; The other includes 14 cases from Yulin where both HCC and HBV were high but AFB1 may be low because rice low in AFB1 was the staple food. Exon 7 were sequenced by DNA direct sequencing. p53 mutational protein and HBsAg were examined by immunostaing. RESULTS: In the Fusui group, 16/26 (61.5%) cases showed mutation at codon 249 third position G to T transversion to form a hot-spot which is generally considered to be caused by AFB1. In the Yulin group, only one single place-Guigang showed p53 mutation clustered at the hot-spot like Fusui in 3/5 cases (60%), while the other cases demonstrated mutational points in various positions. CONCLUSION: Besides Qidong and South Africa, a third AFB1 high risk area was demonstrated where HCC is accompanied by p53 gene specific mutation.

Adult↗
PubMed1997

[Rhinometry of 176 normal adults with acoustic rhinometer].

RH-2000 acoustic rhinometer was used to measure nasal parameters in 176 normal adults. The results showed that nasal minimal cross-sectional area (NMCA) was 0.55 +/- 0.13 cm2 (x +/- s), and nasal cavity volume (NCV) 6 cm beyond the nostrils was 7.16 +/- 1.82 cm3. NMCA was located in the anterior edge of the inferior turbinate and the distance from the nostrils was 2.22 +/- 0.35 cm in 82.7% of the subjects; and the distance from the nostrils to the ostium internum was 0.79 +/- 0.25 cm in 17.3% of them. Our findings indicated that the narrowest segment of the nasal cavity was located in the anterior part, from the ostium internum to the anterior edge of the inferior turbinate. NMCA and NCV were larger in male than in female (P < 0.05). There was significant difference in NMCA and NCV between two sides(P < 0.001). The width of the nasal cavity between two sides might also be different. The measured NMCA and NCV was larger in subjects above 60 years old(P < 0.01, P < 0.05). Acoustic rhinometry is a new objective method to assess the geometry of nasal cavity. NMCA is a valuable objective mark to evaluate nasal patency.

Acoustics↗
PubMed1997

[Survey of botanical origin of tongcao (medulla Tetrapanacis) and identification of its commercial products].

Through the investigation on botanical origin, output and sales of Togcao in producing areas, it has been proved that there are twenty-two species of six families used as Tongcao. The medicinal parts are the pith of stems or petioles. The provinces featuring more species and larger output of Tongcao are Sichuan, Yunnan, Guizhou, Guangxi, Hunan and Shaanxi. A hundred and two pieces of commercial samples collected from twenty-six provinces in China, Hongkong area, Japan, Malaysia, Thailand, Singapore and Republic of Korea have been identified. The result shows that both Xiaotongcao and Datongcao are called by the same name Tongcao. The main species is Xiaotongcao, which takes a proportion of 70% in Tongcao. And the Tongcao(Tetrapanax papyriferus, taking a proportion of 20%) as recorded in the Chinese Pharmacopoeia (1995 edition) is seldom used.

China↗
PubMed1997

[Analysis of chromosome karyotype of Lycium chinense Mill].

The chromosome karyotypes of wild Lycium chinese and its cultivated breeds for vegetable have been studied. The Chromosome 12 of both has a satellite. The former, with 24 chromosomes and 1B karyotype, is a diploid and its karyotype formula is 2n = 2x = 24 = 18m + 6sm. The chromosome number of the latter is 48. As a tetrploid, it has 2B karyotype and a karyotype formula 2n = 4x = 48 = 36m + 12sm.

Chromosomes↗
PubMed1997

[Purification, serology and detection of grapevine leaf roll virus].

Closterovirus-like particles associated with grapevine leaf roll disease were purified from stem phloem tissue by differential centrifugation and cesium sulphate-sucrose density gradient centrifugation. The particles were between 660-2000 nm long. Most of them were about 1400 nm long and also decorated by the antiserum against GLRV NY-1 isolate. The purified preparation was tested for their serological relatedness in indirect ELISA. The results indicated that these closterovirus-like particles reacted with serotype II, III and IV of GLRV. The antiserum to NY-1 (type III) reacted more strongly than type IV (to VA-4) and type II. (to 1800 nm). In sodium dodecyl sulfate immunodiffusion test, the extract of diseased petiole reacted with serotype III, IV and II. It is possible to be infected by 2 or 3 closterovirus-like particles in China. We have made antiserum to the purified closterovirus-like GLRV and set up a PAS-ELISA to detect GLRV-free grapevine plantelets. We have obtaimed 21 varieties of GLRV-free and GFLV-free grapevine. They shown high quality and quantity in field test.

English Abstract↗
PubMed1997

[Computer simulation of system controlling--application to designing of anti-shock resuscitation therapy for burn injured patient].

The computer simulation of aim-controlling of changes in the circulative plasma volume, plasma protein concentration, hematocrit and electrolytes for five burn injured patients during their shock phase was carried out by using back-propagation algorithm of the simulation system. Based on the aim-controlling, the better resuscitation therapy protocol for the patient was given by computer. The clinical application in five cases of the burns showed that the new method helped us to make individualized clinical anti-shock resuscitation formula for the burn injured patient more reasonable.

Burns↗
PubMed1997

[Biological characteristics of residual leukemic cells and their drug-resistant regrowth].

OBJECTIVE: To elucidate the mechanisms of residual leukemia and its drug-resistant regrowth. METHODS: Bone marrow cells from transplantable mouse leukemia models L615 and L7811 were cultivated in long-term culture system respectively. Daunorubicin (DNR) was added to the systems to mimick in vivo chemotherapy. RESULTS: Residual leukemic cells on stromal layers escaped DNR killing. They derived from the adherent leukemic cell population, which was heterogeneous with many undifferentiated and dormant cells. They were drug-resistant and expressed bcl-2 gene. CONCLUSION: Bone marrow stromal layer was the vital microenvironment for the residual leukemic cells to survive and regrow, and might increase the drug-resistance by up-regulating bcl-2 gene expression.

Animals↗
PubMed1997

[9-cis retinoic acid induces apoptosis in HL-60 cells].

OBJECTIVE: To investigate the apoptosis of HL-60 cells induced by 9-cis retinoic acid (9-cis RA), and illustrate the possible molecular mechanism. METHODS: Apoptosis was detected by morphological observation, DNA electrophoresis and flow cytometric cell cycle analysis. Bcl-2 expression was detected by flow cytometry. RESULTS: 9-cis RA initiated apoptosis of HL-60 cells after inducing them irreversibly commited to differentiation. Bcl-2 was downregulated during the differentiation and apoptosis process. 9-cis RA was more potent than all-trans retinoic acid (ATRA) did in inducing terminal differentiation associated apoptosis and in downregulation of Bcl-2 expression. CONCLUSION: 9-cis RA can induce apoptosis in HL-60 cells. Downregulation of Bcl-2 expression appears to play an important role in the apoptosis of the differentiated leukemic cells.

Alitretinoin↗
PubMed1997

[Study of the photoluminescence spectra of laser dye impregnated in porous silicon].

We studied the photoluminescence (PL) of the compound films, which were made by implanting some laser dyes into the porous silicon films, and compared it with the PL of the laser dyes in other states. We also measured the PL of the compound films with different substrates. It was found that the spectra symmetry of the implanted laser dyes is better than that of the dyes in other states. The experimental results suggest that the PL of the compound films mainly comes from the monomers of the implanted laser dyes.

English Abstract↗
PubMed1997

Possible role of indoor environment and coal combustion emission in lung carcinogenesis in Fuyuan County, China.

Fuyuan Country, in Yunnan Province, China has an extremely high lung cancer mortality both in males and non-smoking females. Out of 5768 deaths, 588 patients died of malignant diseases. Lung cancer was the number one cause of death among malignant diseases both in males and females. The rate of lung cancer death to the whole of malignant diseases was 56.2% for males and 55.0% for females. Indoor soot and combustion emission derived from smoky coal produced in northern Fuyuan exhibited high mutagenic activities against Salmonella typhimurium TA98 strain in Ames test. Resected lung tissues derived from the patients with lung cancer in Fuyuan contained significantly higher concentrations of benzo(a)pyrene than those in Japan, both in males and females (i.e., 608.7 +/- 477.1 pg/dry weight for samples of the patients in Fuyuan, 180.1 +/- 104.5 for Japanese non-smokers, and 207.5 +/- 98.8 for Japanese heavy smokers, respectively). These results suggest that mutagenic chemicals contained in coal as well as indoor environment may have a great influence on lung carcinogenesis in Fuyuan, Yunnan Province, China.

Air Pollution, Indoor↗
PubMed1997

Inhibitory effects of Chinese ant extract (CAE) on nephrotoxicity induced by ferric-nitrilotriacetate (Fe-NTA) in Wistar rats.

We observed the inhibitory effects of Chinese ant extract (CAE), a Chinese traditional medicine, on nephrotoxicity induced by Fe-NTA in Wistar rat. Strong positive staining with Schiff's reagent was found in the proximal tubules of the untreated control rats. In contrast, the positivity was very weak in CAE treated rats. The level of TBARS was also higher in the untreated control rats than in CAE treated rats. Meanwhile, the scavenging effect of CAE on hydroxyl radicals was analyzed by electron spin resonance (ESR) in vitro. The results indicate that CAE can efficiently prevent Fe-NTA induced nephrotoxicity through quenching free radicals mechanism.

Animals↗
PubMed1997

[The effect of gestational impaired glucose tolerance on fetus and newborns].

OBJECTIVE: To study the effect of gestational impaired glucose tolerance (GIGT) on fetus and newborns. METHODS: 52 GIGT mothers and 34 gestational diabetes mothers (GDM) were subjected to systematic monitoring prospectively, other 44 normal mothers served as controls. The perinatal outcomes were compared in the three groups. RESULTS: The incidence of macrosmia in the GIGT group was higher than that of the control group (P < 0.025). Neonatal blood glucose level in the GIGT group at 2 hours of age was the lowest in the three groups (P < 0.05). The incidence of hypoglycemia, polycythemia and wet lung in the GIGT group was higher than that of the control group. CONCLUSION: GIGT and GDM are important factors for poor perinatal outcome. Obstetricians and pediatricians must pay more attention to it.

Diabetes, Gestational↗
PubMed1997

[Influence of prenatal exposure to low levels of lead on the neuro-behavioral development of neonates].

OBJECTIVES: To study the effects on the neuro-behavioral development of neonates exposed to low levels of lead in utero. METHODS: 131 neonates were selected and their umbilical blood lead level was determined by Atomic Absorption Spectrometer. The neurobehavioral-cognitive performance of neonates was evaluated by Neonatal Behavioral Neurological Assessment (NBNA). RESULTS: NBNA scores in neonates with blood lead levels greater than or equal to 0.29 mumol/L were markedly lower than those with less than 0.14 mumol/L, and the difference was highly significant. CONCLUSION: Blood lead levels of less than 0.48 mumol/L could still have harmful effects on the development of children.

Child Development↗
PubMed1997

[A study on viremia in patients with hepatitis E].

Hepatitis E virus RNA (HEV RNA) was detected in 531 serial serum specimens collected from 62 hospitalized patients with hepatitis E by reverse transcription-nested polymerase chain reaction (RT-nPCR) setting two pairs of primer from open reading frame 1 (ORF1) to understand the process of HEV infection more thoroughly. Results showed that 71 percent of the patients were positive for HEV RNA. Thirty-two of them with 288 serial serum specimens were followed up for the whole process, and 24 cases (75%) were positive for HEV RNA, positive rates declined with the course of the disease and serum HEV RNA lasted for 20.6 days in average. Serum HEV RNA was kept positive in 36 of the 44 patients (81.8%) at the time their serum alanine aminotransferase (ALT) and serum total bilirubin began to lower, and anti-HEV was detected in 39 of them (88.6%). Proportion of HEV viremia and length of it had no direct relationship with serum ALT and levels of total serum bilirubin and anti-HEV.

Hepatitis E↗
PubMed1996

pH-zone-refining countercurrent chromatography.

A recently developed preparative technique, pH-zone-refining countercurrent chromatography (CCC), separates organic acids and bases according to their pKa and hydrophobicity. The hydrodynamic mechanism of pH-zone-refining CCC is illustrated in two elution modes along with a simple mathematical analysis. Separations include acidic and basic derivatives of amino acids and peptides, hydroxyxanthene dyes, alkaloids, indole auxins, and structural and geometrical isomers. In addition, recently developed affinity ligand separations of enantiomers, polar catecholamines, and free peptides are also described. Technical guidance is provided for interested users so that they can conduct a systematic search for the optimum solvent system and experimental conditions. Advantages as well as limitations of the present technique are discussed.

Countercurrent Distribution↗