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Biomedical subjects

S Zhu

Publications and source records attributed to S Zhu.

At least 163 records · Page 9Linked to original sources
PubMed1999

[Important adjacent relationship of external maxillary artery and clinic significances].

OBJECTIVE: To investigate the important adjacent relationship of the external maxillary artery. METHODS: 60 pieces of complete head-neck samples were dissected layer by layer (only one side per sample), then the adjacent structures of the external maxillary artery, such as the submandibular gland, the anterior facial vein, the marginal mandibular branches of facial nerve and the submandibular lymphatic nodes were observed. RESULTS: 1. 60% of external maxillary artery lay on the bottom of submandibular gland, 38.3% went through the gland and 1.7% on the surface of the gland; 2. 90% of marginal mandibular branches of facial nerve went through the surface of external maxillary artery, 5% on the bottom and 5% encircled and gripped the artery; 3. 6.7% of anterior facial vein lay on the bottom of submandibular gland and accompanied external maxillary artery, 5% went through the gland and accompanied the artery, 88.3% went on the surface of the gland and didn't accompany the artery; 4. There were constant lymphatic nodes in front of and behind the external maxillary artery. CONCLUSION: The adjacent relationship of external maxillary artery is complex, and it is significant for doctors to know the above important structures around the artery.

Adolescent↗
PubMed1999

[Applied anatomic study on intraorbital and intraethmoidal parts of ethmoidal artery].

OBJECTIVE: In order to provide anatomic data for operation of ethmoidal sinus and optic canal decompression. METHOD: Using microanatomic method, the intraorbital and intraethmoidal parts of ethmoidal arteries were observed and measured. RESULT: The length of intraorbital segment of anterior ethmoidal artery was 5.16 +/- 1.24 mm, and its diameter was 0.56 +/- 0.17 mm; the length of intraorbital segment of posterior ethmoidal artery was 9.08 +/- 2.29 mm, with diameter 0.37 +/- 0.14 mm. The ethmoidal artery, nerve and vein were surrounded by fascial sheath which could extend to ethmoidal sinus. Three variants of ethmoidal arteries could be found: It passed through bony canal; It went between the superior wall of ethmoidal cell and ethmoidal mucosa; One part went through bony canal, but the other did not. CONCLUSION: It was important to find ethmoidal artery in operation of ethmoidal sinus and optic canal decompression.

Adult↗
PubMed1999

[Preliminary studies on microwave irradiation ELISA for diagnosis of Schistosomiasis japonica].

AIM: To explore a fast and highly efficient method for the diagnosis of schistosomiasis japonica. METHODS: Using microwave irradiation ELISA (MWI-ELISA) and fast-ELISA to detect specific antibodies in sera from 118 cases with schistosomiasis japonica, 61 healthy individuals and 12 paragonimiasis cases. RESULTS: The positive rates of schistosomiasis cases were 88.1% (104/118) by MWI-ELISA and 91.5% (108/118) by fast-ELISA, respectively (chi 2 = 0.74, P > 0.05). The false positive reaction of healthy individuals was found in 2 cases(3.3%) by MWI-ELISA and 1 case (1.6%) by fast-ELISA, respectively (chi 2 = 0.34, P > 0.05). No false positive reaction was found in paragonimiasis cases. CONCLUSION: The sensitivity and specificity of the two tests were similar, however, MWI-ELISA was faster than fast-ELISA.

Animals↗
PubMed1999

[Temperature measurement and control in prostate therapy apparatus].

The importance and difficulties of the temperature measurement and control in Prostate therapy apparatus are discussses. Plans of the temperature measurement and control, and the characters of the clinical applications are compared. Finally the method of calculating the temperature distribution with few measurement signals and the advantages of using the adaptive generalized predictive control are expounded.

Equipment Design↗
PubMed1998

[The polymorphism of two microsatellites closely linked to the locus for polycystic kidney disease 1 in Chinese population].

OBJECTIVE: To evaluate the polymorphism of AC2.5 and SM7, two microsatellite markers closely linked to the locus for polycystic kidney disease 1 (PKD1), in the Han (Chinese majority) and the Zhuang(the largest minority in China) populations and make clear whether the allele frequencies of these markers exhibit significant differences between populations. METHODS: The two microsatellite markers were amplified by polymerase chain reaction(PCR), followed by 10% non-denatured polyacrylamide gel electrophoresis(PAGE) and DNA sequencing to analyze the PCR products. RESULTS: (1) Ten AC2.5 alleles and eleven SM7 alleles were observed in 104 Chinese Han people, and eight AC2.5 alleles and nine SM7 alleles were observed in 75 Chinese Zhuang people. (2) The expected heterozygosities of AC2. 5 and SM7 were 68.4% and 77.4% in the Han population and 67.1% and 57.5% in the Zhuang population respectively. The polymorphism information content(PIC) values of them were 0.68 and 0.77 in the Han population and 0.67 and 0.57 in the Zhuang population respectively. (3) Several allele frequencies of the two markers exhibited significant differences between populations(P 0.05). CONCLUSION: AC2.5 and SM7 are highly polymorphic and can be used in genetic diagnosis of both Chinese Han and Zhuang PKD1 families. The allele frequency distributions of them exhibit significant difference between populations.

Alleles↗
PubMed1998

Comparison of the mode of action of a dinuclear platinum complex containing a pyridine derivative with its monomeric analog.

The DNA binding and interstrand cross-linking properties of the dinuclear platinum complex [¿cis-Pt(NH3)2Cl¿2bpsu](NO3)2 (bpsu is 4,4'-dipyridyl sulfide) (II) and the mononuclear complex [cis-Pt(NH3)2Cl(4-methylpyridine)]NO3 (I) were compared with those of [¿cis-Pt(NH3)2Cl¿2H2N(CH2)4NH2](NO3)2 (III) in order to understand the mode of action of complexes I and II. Both compound I and compound II caused significantly different changes of conformation in poly(dG-dC) x poly(dG-dC) than compound III did. Studies of DNA binding, interstrand cross-linking and fluorescence assay suggest that compound I monofunctionally binds to DNA and compound II bifunctionally binds to DNA, that the dinuclear platinum complex II more efficiently interacts with DNA compared to its monomeric analog, and that platinum I and II complexes both interact with DNA in a non-intercalative mode. All the results indicate that the mode of action of the dinuclear complex II is different from that of the mononuclear complex I.

Animals↗
PubMed1998

Asbestos inhalation induces reactive nitrogen species and nitrotyrosine formation in the lungs and pleura of the rat.

To determine whether asbestos inhalation induces the formation of reactive nitrogen species, three groups of rats were exposed intermittently over 2 wk to either filtered room air (sham-exposed) or to chrysotile or crocidolite asbestos fibers. The rats were killed at 1 or 6 wk after exposure. At 1 wk, significantly greater numbers of alveolar and pleural macrophages from asbestos-exposed rats than from sham-exposed rats demonstrated inducible nitric oxide synthase protein immunoreactivity. Alveolar macrophages from asbestos-exposed rats also generated significantly greater nitrite formation than did macrophages from sham-exposed rats. Strong immunoreactivity for nitrotyrosine, a marker of peroxynitrite formation, was evident in lungs from chrysotile- and crocidolite-exposed rats at 1 and 6 wk. Staining was most evident at alveolar duct bifurcations and within bronchiolar epithelium, alveolar macrophages, and the visceral and parietal pleural mesothelium. Lungs from sham-exposed rats demonstrated minimal immunoreactivity for nitrotyrosine. Significantly greater quantities of nitrotyrosine were detected by ELISA in lung extracts from asbestos-exposed rats than from sham-exposed rats. These findings suggest that asbestos inhalation can induce inducible nitric oxide synthase activation and peroxynitrite formation in vivo, and provide evidence of a possible alternative mechanism of asbestos-induced injury to that thought to be induced by Fenton reactions.

Animals↗
PubMed1998

Ribosome-binding domain of eukaryotic initiation factor-2 kinase GCN2 facilitates translation control.

A family of protein kinases regulate translation initiation in response to cellular stresses by phosphorylation of eukaryotic initiation factor-2 (eIF-2). One family member from yeast, GCN2, contains a region homologous to histidyl-tRNA synthetases juxtaposed to the kinase catalytic domain. It is thought that uncharged tRNA accumulating during amino acid starvation binds to the synthetase-related sequences and stimulates phosphorylation of the alpha subunit of eIF-2. In this report, we define another domain in GCN2 that functions to target the kinase to ribosomes. A truncated version of GCN2 containing only amino acid residues 1467 to 1590 can independently associate with the translational machinery. Interestingly, this region of GCN2 shares sequence similarities with the core of the double-stranded RNA-binding domain (DRBD). Substitutions of the lysine residues conserved among DRBD sequences block association of GCN2 with ribosomes and impaired the ability of the kinase to stimulate translational control in response to amino acid limitation. Additionally, as found for other DRBD sequences, recombinant protein containing GCN2 residues 1467-1590 can bind double-stranded RNA in vitro, suggesting that interaction with rRNA mediates ribosome targeting. These results indicate that appropriate ribosome localization of the kinase is an obligate step in the mechanism leading to translational control by GCN2.

Amino Acid Sequence↗
PubMed1998

A transcript map of an 800-kb region on human chromosome 11q13, part of the candidate region for SCA5 and BBS1.

The exon-amplification method was used to identify putative transcribed sequences from an 800-kb region that includes the genes for phospholipase Cbeta3 and PYGM on human chromosome 11q13. The clone contig consisted of ten cosmids, three bacterial artificial chromosomes, and one P1 artificial chromosome. A total of 83 exons were generated of which 23 were derived from known genes and expressed sequence tags (ESTs). Five different EST cDNA clones were identified and mapped on the contig. One is a homolog of the human p70S6 kinase (p70s6 k) gene whose function involves the translational regulation of ribosomal protein synthesis and thereby impacts on ribosomal biogenesis. The gene for p70s6 k is expressed universally, including within adipose cells and retina, and it could play a role in Bardet-Biedl syndrome type 1, which has been mapped to 11q13.

Chromosome Mapping↗
PubMed1998

Dinuclear palladium(II) complexes containing two monofunctional [Pd(en)(pyridine)Cl]+ units bridged by Se or S. Synthesis, characterization, cytotoxicity and kinetic studies of DNA-binding.

Two novel dinuclear palladium(II) complexes, ¿[Pd(en)Cl]2(bpse)¿(NO3)2 (1) and ¿[Pd(en)Cl]2 (bpsu)¿(NO3)2 (2), (where en is ethylenediamine; bpse is bis(3-methyl-4-pyridyl) selenide; bpsu is bis(3-methyl-4-pyridyl) sulfide) have been synthesized. The complexes have been characterized by elemental analysis, IR, 1H NMR, and 13C NMR. They have been assayed for antitumor activity in vitro against the mice leukemia L1210 and the human coloadenocarcinoma HCT8 cell lines. The results show that compound 1 has a lower I.D.50 value against the two cancer cell lines as compared to compound 2; the compounds also shows a lower I.D.50 value than cisplatin against the HCT8 cell line, but a higher I.D.50 value than cisplatin against the L1210 cell line. Binding studies indicate that compound 1 possibly interacts with DNA by a nonintercalative mode. Kinetics of binding of the two compounds to DNA are firstly studied using ethidium bromide as a fluorescence probe with stopped-flow spectrophotometer under pseudo-first-order condition. The stronger binding of two steps in the process of the compounds interacting with DNA are observed, and the Kobs and Ea of binding of the two steps (where Kobs is the observed pseudo-first-order rate constant, Ea is the observed energy of activation) are obtained.

Animals↗
PubMed1998

Palladium(II) complexes with N,N'-dialkyl-1,10-phenanthroline-2,9-dimathanamine: synthesis, characterization and cytotoxic activity.

Five new tetradentate ligands and their corresponding palladium complexes, [Pd(L)]Cl2 (L = N,N'-dimethyl-1,10-phenanthroline-2,9-dimathanamine, N,N'-diethyl-1,10-phenanthroline-2,9-dimathanamine, N,N'-dipropyl-1,10-phenanthroline-2,9-dimathanamine, N,N'-ditert-butyl-1,10-phenanthroline-2,9-dimathanamine, N,N'-dicyclohexyl-1,10-phenanthroline-2,9-dimathanamine) have been synthesized. The ligands and their complexes have been characterized by elemental analysis, IR, and 1H NMR. The complexes have been assayed for antitumor activity in vitro against the mouse leukemia L1210 and the mouse liver carcinoma Bel7402 cell lines. The results showed that the activities of these complexes are significantly dependent on the nature of the alkyl groups on the coordinated amine moieties, and three of these palladium complexes showed lower ID50 values against the two cell lines than cisplatin.

Animals↗