Biomedical subjects

H Yang

Publications and source records attributed to H Yang.

At least 667 records · Page 37Linked to original sources

PubMed1997

[Construction of genomic library of L. interrogans serovar lai using lambda gt11 as the vector and a study of recombiant plasmid pDL121].

A genomic library of L. interrogans serovar lai strain 017 has been constructed using lambda gt11 as the vector. DNA was partially digested by two blunt-end restriction enzymes, then methylated with EcoR I methylase; after EcoR I linker was added to the DNA, the linker-ended DNA was ligated to the dephosphorylated EcoR I digested lambda gt11 arms. The recombined DNA was packaged in vitro, and used to transduct E. coli Y1090 for amplification. There were 2.1 x 10(6) recombinant bacteriophages as recognized by their ability to form white plaques plated on Lac host in the presence of both IPTG and X-Ga1. A positive clone, designated lambda DL12, was screened with a rabbit anti-serum against L. interrogans serovar lai from the genomic library. The DNA from lambda DL12 was subcloned into plasmid pUC18. A recombinant (designated as pDL121) was obtained. SDS-PAGE analysis indicated that a 23 kd was expressed in E. coli JM 103 harboring pDL121. Western blotting analysis showed that a specific protein band molecular weight of 23 kd could be recognized by the rabbit antiserum against L. interrogans serovar lai strain 017.

Cloning, Molecular↗

PubMed1997

[Influence of transfection of sense- and antisense-TGF beta 1 gene on human pulmonary giant cell carcinoma cell proliferation].

OBJECTIVE: To investigate the effect of human sense- and antisense-transforming growth factor beta 1 (TGF beta 1) gene on human pulmonary giant cell carcinoma cell (PLA-801D) proliferation. METHODS: PLA-801D cells were transfected with an expression vector containing a full length human sense- or antisense-TGF beta 1 gene by gene transfer. The changes of cell proliferation, expressions of nm23 mRNA and c-myc mRNA and the feature of apoptosis were studied on transfected cells and untransfected cells. RESULTS: The cells transfected by sense-TGF beta 1 gene showed higher TGF beta 1 activity in the conditioned media, growth inhibition in vitro and decreased coloning formation in anchorage-independent assay. The tumorigenic rate was reduced about 47%, the metastasis was inhibited in athymic nude mice as compared with untransfected cells group. The mechanism of such changes described may be associated with the higher expression of nm23 mRNA, and the lower expression of c-myc mRNA as well as the apoptosis in sense-TGF beta 1 gene transfected cells. However, opposing changes were observed in the antisense-TGF beta 1 gene transfected cells. CONCLUSION: TGF beta 1 acts as a negative growth regulator of the PLA-801D in vitro as well as in vivo.

Animals↗

PubMed1997

[Effect of cultivating measures on the tuber yield of Curcuma longa L].

The effect of cultivating measures on the tuber yield of Curcuma longa was observed. dibble planting has been proved move effective in raising the tuber yield than drill culture, and the dibble planting quantity has no effect on the tuber. The rational producing area, soil, seed tuber and so on were selected according to the experiments.

Methods↗

PubMed1997

[Loss of heterozygosity on chromosome 17p13.3 in ovarian cancer and cervical cancer].

OBJECTIVE: To identify the loss of heterozygosity (LOH) on chromosome 17p13.3 in ovarian cancer and cervical cancer. METHODS: The frequency of LOH on chromosome 17p13.3 in DNA samples from 24 ovarian cancers, 9 cervical cancers, and 13 non-malignant gynecological diseases were determined respectively, using Southern blot method with probe PYNZ. 22. RESULTS: LOH on 17p13.3 was found in 12 of 24 (50.0%) ovarian cancers (including a borderline mucinous cystadenoma), 4 of 9 (44.4%) cervical carcinomas, and 1 of 13 (7.7%) non-malignant gynecological diseases, which was cervical intraepithelial neoplasm III (CIN III) (P < 0.01). CONCLUSION: These results show that LOH on 17p13.3 is associated with ovarian cancer and cervical cancer, suggesting that detection of LOH on 17p13.3 may be helpful to understand the molecular pathogenesis of ovarian cancer and cervical cancer.

Adult↗

PubMed1997

[Effects of spinal cord extract on neurite growth of GABAergic and dynergic neurons of spinal cord in vitro].

We use the crude extract from human fetal spinal cord to study the effect of endogenous substances of the spinal cord on neurite growth of E 12-15 mouse GABAergic and DNYergic neurons of the spinal cord in vitro. The results indicated that the crude extract had no effect on GABAergic neurons but had markedly neurite-promoting effect on DNYergic neurons when the protein concentration of the crude extract was 250 micrograms/ml. It suggests that there are endogenous substances in the crude extract of the human fetal spinal cord, which can promote neurite growth of spinal cord neurons and this effect is neuron type specific at particular embryonic age.

Animals↗

PubMed1997

Electrophoretic determination of aqueous and serum neuron-specific enolase in the diagnosis of retinoblastoma.

PURPOSE: Neuron-specific enolase (NSE) of containing gamma-enolase is considered valuable in the diagnosis of tumours of neuroectodermal origin. METHOD: We used rapid electrophoretic method on cellulose acetate plate to determine the pattern of enolase isoenzymes in 21 aqueous humor and 23 serum specimens from retinoblastoma (Rb) and 21 aqueous and 25 serum specimens from 25 control cases to evaluate NSE in the diagnosis of Rb. The assay allowed assessment of all three major isoenzymes (alpha alpha, alpha gamma and gamma gamma), and NSE relative activity and its percentage in the total relative activity of the three enolase isoenzymes were assessed by means of fluorometer. RESULT: Aqueous from all patients with Rb contained alpha alpha, alpha gamma and gamma gamma isoenzymes and presented strong positive, the positive rate of NSE being 100% and its relative activity accounting for 45 +/- 9% of the total relative activity of the 3 enolase isoenzymes; No enolase was detectable in control aqueous with cataract, glaucoma and Coats's diseases (4 cases), but in two patients with traumatic hyphema alpha alpha and faint alpha gamma and gamma gamma were presented in aqueous. The control serum contained only an alpha alpha band, while the sera form patients with Rb contained alpha alpha, alpha gamma and gamma gamma bands in 18 of 23 specimens, the positive rate being 78.2%, and only alpha alpha bands in the rest 5 specimens (21.8%). In patients with Rb, the NSE relative activity and its percentage in the total relative activity of the 3 isoenzymes in serum (36 +/- 9%) were significantly lower lever than those in aqueous. CONCLUSION: The amounts of NSE increase significantly in both serum and aqueous from patients with Rb, and the immunoelectrophoretic assay for determination of enolase patterns is valuable in the diagnosis of Rb and differential diagnosis of Rb. In addition, the method is rapid, simple and requires only a little amount (< 5 microL) of samples.

Aqueous Humor↗

PubMed1997

[Color Doppler imaging of persistent heperplastic primary vitreous].

PURPOSE: To evaluate Color Doppler Imaging (CDI) in the value of Persistent Hyperplastic Primary Vitreous(PHPV). METHODS: 3 cases (4 eyes) of PHPV were reproted and were examinated by high resolution CDI, the blood flow pattern was evaluated in basic of two dimensional grayscale image. RESULTS: CDI shows a band vascular structure coursing through the band-shaped moderately echogenic structure in the central portion of vitreous chamber, with the apex located near the optic disk and the base extending toward the lens. Spectral display of the Doppler signal indicated arterial flow. CONCLUSION: Central vessel exhibiting arterial flow is compatible with a prominent persistent hyaloid vascular structure. This CDI imaging feature, in addition to microphthalmia and lack of calcification, is virtually pathogenomonic of PHPV and aids in enabling distinction between PHPV and simulating lesions.

Arteries↗

PubMed1997

[Cloning and restriction analysis of saw1--a key gene for differentiation of Streptomyces ansochromogenes].

saw1--a essential gene for sporulation of Streptomyces ansochromogenes was cloned, 7 kb of DNA fragment in Streptomyces plasmid pIJ702 could recover the sporulation of saw1-deficient strain W51 which could not form spore with white phenotype of aerial hyphae. The recombinant plasmid was deleted by some restriction enzymes, the result showed that 2.5 kb DNA fragment in pIJ702 still has function to recover sporulation of W51. The sequencing and expression of saw1 gene is carrying out at present.

Cloning, Molecular↗

PubMed1997

[The primary study of ultrasound biomicroscope in imaging anterior segment tumors of eye].

PURPOSE: To evaluate the use of ultrasound biomicroscope (UBM) in imaging anterior segment tumors of eye. METHODS: 13 cases of anterior segment tumors of eye were examined with UBM. RESULTS: 3 cases had the ocular history of trauma or surgery and were clinically diagnosed as anterior iris cysts. UBM displayed the cysts as thin-walled, no internal reflectivity, and at the locate of anterior humour angle; 8 cases had superficial anterior humour, narrow anterior angle and clinically be suspected as tumors behind iris or ciliary body. UBM showed cystic reflectivity in 7 cases and a solid tumor in ciliary body in one case. 2 cases were clinically diagnosed as iris nevi. UBM displayed solid convex lesions. CONCLUSION: UBM is a valuable new technique in the diagnosis and accurate localization of anterior segment tumors.

Adult↗

PubMed1997

[Herbological study of 4 Chinese herbs in Ardisia and "yiedihong"].

Herbological study are given to the original plants of "Zijinniu", "Pingdimu", "Xiaoqing", "Duanjiaosanlang" and "Yiedihong" recorded in the herbal books. The research shows that they are not the same plant with different names. Also, "Yiedihong" doesn't belong to Ardisia.

Ardisia↗

PubMed1997

[An analysis of maicaodi by high performance liquid chromatography].

Maicaodi has recently been developed and produced by the pesticide plant of Nanjing Agricultural University. The quantitative analysis of the effective components--tribenuron methyl and R (-)napropamide in wettable powder of Maicaode, by a high performance liquid chromatographic method was carried out with a Lichrosorb Si-60 20cm x 0.46cm i.d. column, mobile phase of petroleum ether/isopropanol/methanol/acetonitrile/chloroform mixture solvent (80:5:5:5:5) and internal standard of diisooctyl phthalate. The sample was detected by ultraviolet absorption at 254 nm. The retention times of tribenuron methyl and R (-)napropamide were 10-11min and 6-7min respectively. The coefficient of variation of this analysis was 0.34% with a recovery of 99.51%-100.32%. The coefficient of linear correlation was 0.9999.

Chromatography, High Pressure Liquid↗

PubMed1997

[Packed glass capillary column with multi-cores].

The paper describes the preparation of the columns with multi-cores and their plate heights, optimum gas velocity, minimum plate heights (HETP) and corresponding pressure drop (deltaP=Pi-Po) were measured. It is found that HETP increases as core number increase, but column pressure drop (deltaP) decrease with increase of core number. The conclusion is: 1. The column with multi-cores have a better permeability than the conventional packed capillary column. Although its column efficiency is lower than that of the conventional one when packed particles is in the same column size, the comprehensive properties (N/deltaP) are evidently superior than the conventional capillary column. 2. The pressure drop decreasesas the number and diameter of the core in packed capillary column increase. 3. When packed column particle size gets smaller, column efficiency gets higher, but the particle inlay bacomes difficult. The existence of the cores will make the column efficiency get some loss, but it can improve the column permeability and the inlaid geomery. 4. In considering pressure drop, HETP and the particle inlaid condition in column fabrication as a whole, the optimum column type is the packed capillary column with three cores. 5. Ideal column size is: deltad=1-1. 5dp,d=1-2dp,n> or =3, dp=140-250 mesh.

English Abstract↗

PubMed1997

[The analysis of C4 and C5 olefins in cracking gasoline].

The paper described the analytical method of butenes and pentenes in cracking gasoline with a boiling point range from initial to 210 degrees C. Beside the C3 (propane + protene) and n, i-C4 = (n-butene + i-butene) combine peaks, all C2-C5 components in the sample were separated on the OV-1 column. The proportion of the combined peaks was determined on the Al2O3 column. The quantitative results were calculated on the data determined from the above one-column analytical systems with a relative standard deviation < 8%. Comparing with the ASTM D2427-87, the simple operation, easy application, good repetition and all component results were characteristic of the method.

Alkenes↗

PubMed1997

CAND3: a ubiquitously expressed gene immediately adjacent and in opposite transcriptional orientation to the ATM gene at 11q23.1.

Using a magnetic beads-mediated cDNA selection procedure and a fetal brain expression library, we identified a transcriptional unit within a cosmid positive for the marker D11S384. Pursuit of its full-length cDNA led to the cloning of the third candidate gene (CAND3) we studied in our quest for the ataxia-telangiectasia (A-T) gene, ATM. CAND3 spans approximately 140 kb of genomic DNA and is located immediately centrimeric to ATM, with 544 bp of DNA separating the two genes. CAND3 encodes two ubiquitously expressed transcripts of approximately 5.8 kb and approximately 4.6 kb that are divergently transcribed from a promoter region common to ATM. Nucleotide sequence was determined for one of its alternately spliced transcripts. The predicted protein has 1175 amino acids and is novel in sequence, with only weak homologies to transcriptional factors, nucleoporin protein, and protein kinases, including members of the phosphatidylinositol 3-kinase (PI-3 kinase) family. Although neither homology to ATM nor any mutation of CAND3 in A-T patients has been found, the head-to-head arrangement of CAND3 and ATM, with expression of both housekeeping genes from a common stretch of 544 bp intergenic DNA, suggests a bi-directional promoter possibly for co-regulation of biologically related functions. YACs, BACs, cosmids, and STSs are defined to aid in further study of this gene.

Amino Acid Sequence↗

PubMed1997

Analysis of ICAM-1 gene polymorphism in immunologic subsets of inflammatory bowel disease.

Inflammatory bowel disease (IBD) consists of ulcerative colitis (UC) and Crohn's disease (CD) - two chronic idiopathic inflammatory diseases of the gastrointestinal tract. Although exogenous or infectious agents might contribute to the pathogenesis or trigger the onset of disease, and the immune system certainly mediates tissue damage, it is clear from available data that the genetic factors determine the susceptibility of a given individual. IBD is characterized by a failure to downregulate the usual self-limited gut inflammatory response, suggesting that one or more of the predisposing genes could be those that determine the level of the immune response along the inflammatory pathway. Thus, we examined potential associations of intercellular adhesion molecule- 1 (ICAM- 1) gene polymorphisms with IBD or subsets of IBD by studying 118 UC and 130 CD patients, and 77 ethnically matched controls. These subjects were tested for antineutrophil cytoplasmic antibody (ANCA) and genotyped by PCR and ASO techniques for ICAM1 polymorphisms at codon 241 (exon 4) and codon 469 (exon 6). There was no significant difference between all UC patients, CD patients, and controls in either polymorphism. However, when stratified by ANCA status, ANCA-negative UC exhibited a borderline statistically significant increase of the R241 allele compared to ANCA-positive UC patients (28 vs. 12%, p = 0.05). In contrast, it was ANCA-positive CD that had a significantly increased allele frequency compared to ANCA-negative CD (36 vs. 16%, p = 0.018). Since the codon 241 polymorphism is in a functionally important domain III of ICAM-1, we may have identified an actual responsible genetic variation for genetically heterogeneous subsets of both of UC and of CD. Further characterization of ANCA and the understanding of functional significance of the ICAM-1 polymorphism will help delineate immunopathogenesis in certain subgroups of IBD patients.

Animals↗

PubMed1997

Initial study on naturally occurring products from traditional Chinese herbs and vegetables for chemoprevention.

A number of naturally occurring products from vegetables and herbs exert chemopreventive properties against carcinogenesis. In this paper, two such compounds, isolated from garlic and from a traditional Chinese medicinal herb, are described for review. Elemene, isolated from the Chinese medicinal herb Rhizoma zedoariae, was shown to exhibit antitumor activity in human and murine tumor cells in vitro and in vivo. This novel antineoplastic agent has substantial clinical activity against various tumors. The in vitro effect of elemene on the growth of leukemia cells was evaluated by MTT assay. The IC50 values of elemene for promyelocytic leukemia HL-60 cells and erythroleukemia K562 cells were 27.5 micrograms/mL and 81 micrograms/mL, respectively, while IC50 for peripheral blood leukocytes (PBL) was 254.3 micrograms/mL. The inhibitory effect of elemene on proliferation of HL-60 cells was associated with cell cycle arrest from S to G2M phase transition and with induction of apoptosis. The apoptosis of tumor cells was confirmed by DNA ladder formation on gel electrophoresis and characteristic ultrastructural alterations. The results also demonstrated that inhibitory effects of allicin, a natural organosulfide from garlic, on proliferation of tumor cells were associated with the cell cycle blockage of S/G2M boundary phase and induction of apoptosis. These findings suggest that induction of apoptosis may contribute to the mechanisms of antitumor activity of elemene and allicin, which merit investigation as potential chemoprevention agents in humans.

Anticarcinogenic Agents↗

PubMed1997

Oxygen free radical injury and its relation to bacterial and endotoxin translocation after delayed fluid resuscitation: clinical and experimental study.

OBJECTIVE: To examine whether there is generation of oxygen free radicals (OFR) and lipid peroxidation of cell membrane after volume replacement for burn shock, and to study the relationship between OFR injury and enterogenous endotoxemia. METHODS: Forty-seven burn patients were involved in this study. Among them, 18 had delayed fluid resuscitation (DR) and the others had early fluid resuscitation (ER) within 6 hours postburn. Sixty-six gnotobiotic rats were used in a collaborating experiment as burn models. They were divided into 4 groups: sham injury (n = 6), early resuscitation (n = 24), late resuscitation (n = 24) and vitamins E and C treatment group (n = 12). All the rats, except those in the sham injury group, were inflicted with 40% total body surface area (TBSA) third-degree burns. OFR was determined in the blood of patients with electron spin resonance (ESR). S/W ratio and tau c values of patients' erythrocytes were measured with ESR spectrometer. Blood superoxide dismutase (SOD) and glutathione peroxidase (GSHPx) activities, malondialdehyde contents and plasma endotoxin levels were assayed. Rats were sacrificed at the 12th, 24th, 48th and 72nd hour after injury. Plasma endotoxin levels, mucosal SOD, GSHPx and malondialdehyde (MDA), as well as diamine oxidase activity of ileum were determined. Cultures of mesenteric lymph nodes (MLN), liver, spleen, heart, lung, kidney and blood were done. RESULTS: A significant increase in blood OFR contents and plasma MDA, and a significant decline in blood SOD and GSHPx were found after resuscitation in DR group as compared with those in ER group. Both strong to weak spectra component (S/W) ratio and tau c value were higher in DR group in contrast with those in ER group. Higher elevation in plasma endotoxin level in DR group was seen. In DR group, plasma MDA content was correlated with S/W ratio, tau c value and plasma endotoxin level. In rats, the level of mucosal MDA, plasma endotoxin and incidence of bacterial translocation (BT) were significantly higher. Mucosal SOD, GSHPx and diamine oxidase (DAO) activity were significantly lower in DR group as compared with those in ER group. In DR group, mucosal MDA content was negatively correlated with mucosal DAO activity, while the latter was negatively correlated with BT. After treatment with vitamins E and C, mucosal MDA content decreased, plasma endotoxin and BT significantly declined and mucosal DAO heightened. CONCLUSIONS: Tissue reperfusion might induce the production of OFR, resulting in lipid peroxidation injury, especially to intestinal mucosa, and resulting in disruption of mucosal barrier function followed by endotoxemia and BT.

Adolescent↗

PubMed1997

[Clinical analysis of pregnancy with overt diabetes complicated with retinopathy].

OBJECTIVE: To study the outcome of pregnancy in overt diabetes with retinopathy and the changes of retinopathy during pregnancy. METHOD: Retrospective study was made on 49 pregnancies with overt diabetes from 1981 to 1995. RESULTS: Maternal complications and perinatal morbidity were higher in pregnancies with retinopathy but there were no significant differences between those with and without retinopathy. Retinopathy progressed during pregnancy i 31.1% of the parturients. CONCLUSION: Pregnancies with overt diabetes complicated with retinopathy are not the indications for terminating pregnancy, but the changes of retinopathy should be carefully monitored during pregnancy.

Adult↗