Biomedical subjects

P Shen

Publications and source records attributed to P Shen.

At least 55 records · Page 3Linked to original sources

PubMed2000

[Experimental study on effect of qishejingkang recipe on activity of alkaline phosphatases in osteophyte formation of degenerated cervical vertebrae of rabbits].

OBJECTIVE: To study the effect of Qishejingkang recipe (QSJKR) on activity of alkaline phosphatase (ALP) in osteophyte formation of degenerated cervical vertebrae. METHODS: A model of degenerated cervical vertebrae in the rabbit was established through resection of the cervical supraspinous and interspinous ligaments from the cervical spine elicited by surgical intervention. The sites of osteophyte was observed with a light microscope. The activity of ALP of the annuls fibrosis and nucleus pulpous, end-plate in each cervical spine was assayed with biochemical method respectively. RESULTS: Osteophyte come from end-plate, the activity of ALP in the degenerated end-plate in QSJKR group declined significantly compared with model group. CONCLUSION: QSJKR could decrease the activity of ALP in end-plate of degenerated cervical vertebrae and it might inhibit the formation of osteophyte.

Alkaline Phosphatase↗

PubMed2000

[Influence of a G/A substitution at -75 bp promoter region of apolipoprotein A I gene and wine consumption on the plasma apolipoprotein A I levels in Yi and Han Chinese].

OBJECTIVE: To study the influence of a common polymorphism of the human apolipoprotein A I gene promoter at a position of -75 bp upstream of the transcription start site and wine consumption on plasma lipid levels. METHODS: 742 healthy Yi and Han healthy subjects all above 15 years old to be the total population which was divided into three samples, namely, Yi-farmer sample, Yi-emigrant sample and Han-resident sample for this study. Estimations of plasma lipids and apolipoproteins were carried on through an auto-analyzer. Genetic DNA was prepared from the frozen blood clot using Triton x-100 lysis technique. Amplification of a 432 bp fragment of the apoA I gene promoter was performed via the PCR, followed by restriction digestion, electrophoresis and identification of the genotypes involved. Data analysis was done at last. RESULTS: Four groups of alcohol consumption were defined: the non-drinkers, 1 - 25 g alcohol intake/day, 26 - 75 g alcohol/day and > 75 g alcohol/day. A tendency of a mild persistent elevation of plasma HDL-C and apoA I was noticed corresponding to an increase of the amount of alcohol intake, and with no evidence of threshold effect observed in the samples of both the Yi-farmers and the Han people. Similar phenomenon was obtained in the sample of Yi-emigrants, but no statistical significance. The frequencies of the A allele of all 3 samples were similar. In Han and Yi-emigrant samples, the drinkers with genotypes of GG had a higher plasma HDL-C and apoA I level than that of the non-drinkers with the same genotypes. Drinkers with A allele had a lower plasma HDL-C and apoA I level than that of drinkers without A allele, and the non-drinkers with A allele had a higher levels of apoA I than of non-drinkers with genotypes of GG. It is estimated that 18% of the variability of plasma apoA I level could be explained by the G/A polymorphism in non-drinkers of Yi-emigrants (F = 8.94, P < 0.01). CONCLUSIONS: Current data suggest that a moderate alcohol consumption or a G to A substitution could make a lower incidence of CHD, but the beneficial effect of one will be negated by the other when both factors occur simultaneously. This finding is seemed valuable for a further study on the effect of the environmental factor or genetic factor in effecting the plasma apoA I level afterwards.

Adolescent↗

PubMed2000

[Bacillus subtilis undergoes natural genetic transformation on agar plates].

This paper conducted preliminary investigation on natural genetic transformation of Bacillus subtilis on agar plates. The results showed that, under same conditions, the natural transformation of the strain on agar plate was much more efficient than that of standard liquid method, and the transformation system could sustain higher DNase concentration. In addition, that the LB culture, which usually did not support the strain acquire competency, could undergo transformation as soon as it being spread on agar plate, suggested that the natural genetic transformation of Bacillus subtilis on solid plates may be different form the standard liquid transformation method. The cell-to-cell transformation between strains having different genetic makers could also be observed on agar plates.

Agar↗

PubMed2000

[Study on the relationship between microvascular density and prognosis in laryngeal cancer].

OBJECTIVE: To study the relationship between the microvascular density(MVD) and the prognosis in laryngeal cancer. METHOD: Microvessel quantitation in 31 cases of laryngeal cancer was done with factor VIII-related antibody and SABC method. RESULT: The quantitation of microvessels in laryngeal cancer were negative of histologic grade and type, but were significantly different (P < 0.05) between metastasis (10.23 +/- 0.78) and without metastasis(6.38 +/- 0.33) two years after operation. CONCLUSION: The angiogenesis of laryngeal cancer is correlated with the lymph node metastasis and prognosis.

Adult↗

PubMed1999

Expression of a truncated receptor protein tyrosine phosphatase kappa in the brain of an adult transgenic mouse.

Receptor protein tyrosine phosphatases (RPTPs) comprise a family of proteins that feature intracellular phosphatase domains and an ectodomain with putative ligand-binding motifs. Several RPTPs are expressed in the brain, including RPTP-kappa which participates in homophilic cell-cell interactions in vitro [Y.-P. Jiang, H. Wang, P. D'Eustachio, J.M. Musacchio, J. Schlessinger, J. Sap, Cloning and characterization of R-PTP-kappa, a new member of the receptor protein tyrosine phosphatase family with a proteolytically cleaved cellular adhesion molecule-like extracellular region, Mol. Cell. Biol. 13 (1993) 2942-2951; J. Sap, Y.-P. Jiang, D. Friedlander, M. Grumet, J. Schlessinger, Receptor tyrosine phosphatase R-PTP-kappa mediates homophilic binding, Mol. Cell. Biol. 14 (1994) 1-9]. The homology of RPTP-kappa's ectodomain to neural cell adhesion molecules indicates potential roles in developmental processes such as axonal growth and target recognition, as has been demonstrated for certain Drosophila RPTPs. The brain distribution of RPTP-kappa-expressing cells has not been determined, however. In a gene-trap mouse model with a beta-gal+neo (beta-geo) insertion in the endogenous RPTP-kappa gene, the consequent loss of RPTP-kappa's enzymatic activity does not produce any obvious phenotypic defects [W.C. Skarnes, J.E. Moss, S.M. Hurtley, R.S.P. Beddington, Capturing genes encoding membrane and secreted proteins important for mouse development, Proc. Natl. Acad. Sci. U.S.A. 92 (1995) 6592-6596]. Nevertheless, since the transgene's expression is driven by the endogenous RPTP-kappa promoter, distribution of the truncated RPTP-kappa/beta-geo fusion protein should reflect the regional and cellular expression of wild-type RPTP-kappa, and thus may identify sites where RPTP-kappa is important. Towards that goal, we have used this mouse model to map the distribution of the truncated RPTP-kappa/beta-geo fusion protein in the adult mouse brain using beta-galactosidase as a marker enzyme. Visualization of the beta-galactosidase activity revealed a non-random pattern of expression, and identified cells throughout the CNS that display RPTP-kappa promoter activity. Several neural systems highly expressed the transgene-most notably cortical, olfactory, hippocampal, hypothalamic, amygdaloid and visual structures. These well-characterized brain regions may provide a basis for future studies of RPTP-kappa function.

Age Factors↗

PubMed1999

Distribution of haplotypes from a chromosome 21 region distinguishes multiple prehistoric human migrations.

Despite mounting genetic evidence implicating a recent origin of modern humans, the elucidation of early migratory gene-flow episodes remains incomplete. Geographic distribution of haplotypes may show traces of ancestral migrations. However, such evolutionary signatures can be erased easily by recombination and mutational perturbations. A 565-bp chromosome 21 region near the MX1 gene, which contains nine sites frequently polymorphic in human populations, has been found. It is unaffected by recombination and recurrent mutation and thus reflects only migratory history, genetic drift, and possibly selection. Geographic distribution of contemporary haplotypes implies distinctive prehistoric human migrations: one to Oceania, one to Asia and subsequently to America, and a third one predominantly to Europe. The findings with chromosome 21 are confirmed by independent evidence from a Y chromosome phylogeny. Loci of this type will help to decipher the evolutionary history of modern humans.

Animals↗

PubMed1999

Identification of a Drosophila brain-gut peptide related to the neuropeptide Y family.

A neuropeptide F (NPF) was isolated from the fruit fly, Drosophila mellanogaster, based on a radioimmunoassay for a gut peptide from the corn earworm, Helicoverpa zea. A partial sequence was obtained from the fly peptide, and a genomic sequence coding for NPF was cloned after inverse polymerase chain reaction and shown to exist as a single genomic copy. The encoded, putative prepropeptide can be processed into an amidated NPF with 36 residues that is related to invertebrate NPF's and the neuropeptide Y family of vertebrates. In situ hybridization and immunocytochemistry showed that Drosophila NPF was expressed in the brain and midgut of fly larvae and adults.

Amino Acid Sequence↗

PubMed1999

Determination of interaction mechanism of sensorgrams by analysis of binding kinetics.

We monitored the interactions between pairs of molecules where the antigen adenylate kinase (AK) was immobilized on the surface of a chip and the antibody against AK, McAb3D3, was in solution. The association data that we obtained were not always accurately described by the expected pseudo-first-order reaction mechanism. A better description of the association data was achieved with a double-exponential function. Various models were applied to describe these observations: mass transport-controlled processes, inhomogeneous immobilized ligands, or inhomogeneous soluble analytes. Inhomogeneous immobilized ligands seemed to be the most likely explanation for the observed biphasic association kinetics. We simulated the kinetics of the SPR signal under the above-mentioned conditions. Plots of dR/dt versus R of the association phase showed characteristic differences between those nonlinearities resulting from mass transport limitation and those from inhomogeneous ligands. The plots of dR/dt versus R of McAb3D3 binding to immobilized AK show positive curvatures, indicating that the observed biphasic association kinetics is due to the inhomogeneity of the immobilized ligands. This is consistent with the results obtained from the comparison of various model fittings.

Adenylate Kinase↗

PubMed1999

Y-Chromosome evidence for a northward migration of modern humans into Eastern Asia during the last Ice Age.

The timing and nature of the arrival and the subsequent expansion of modern humans into eastern Asia remains controversial. Using Y-chromosome biallelic markers, we investigated the ancient human-migration patterns in eastern Asia. Our data indicate that southern populations in eastern Asia are much more polymorphic than northern populations, which have only a subset of the southern haplotypes. This pattern indicates that the first settlement of modern humans in eastern Asia occurred in mainland Southeast Asia during the last Ice Age, coinciding with the absence of human fossils in eastern Asia, 50,000-100,000 years ago. After the initial peopling, a great northward migration extended into northern China and Siberia.

Africa↗

PubMed1999

Global sequence diversity of BRCA2: analysis of 71 breast cancer families and 95 control individuals of worldwide populations.

The aim of this study was to evaluate the prevalence of simple sequence variation in the BRCA2 gene. To this end, 71 breast and breast-ovarian cancer (HBC/HBOC) families along with 95 control individuals from a wide range of ethnicities were analyzed by means of denaturing high-performance liquid chromatography (DHPLC) and direct sequence analysis. In the coding (10 257 bp) and non-coding (2799 bp) sequences of BRCA2, 82 sequence variants were identified. Three different, apparently disease-associated BRCA2 mutations were found in six HBC/HBOC families (8%): two splice site mutations in introns 5 and 21, and one frameshift mutation in exon 11. In the coding region, 53 simple sequence variants were found: 35 missense mutations, one 2 bp deletion (CT) resulting in a stop at codon 3364, one nonsense mutation with a stop at codon 3326, one deletion of a complete codon (AAA) resulting in the loss of leucine, and 15 silent mutations. In the non-coding region, 26 polymorphisms were detected. Of the 79 sequence variants that were not obviously disease-associated, eight were detected only in HBC/HBOC families. The remaining 71 variants were identified in both HBC/HBOC families and control individuals. Sixty three sequence variants (80%) were specific for a continent. Forty two percent (33 out of 79) of the sequence variants were detected exclusively in Africa, though only 13% of the 332 chromosomes screened were of African origin. Our data indicate that, in BRCA2, simple sequence variation is frequent [in the coding region 1 in 194 bp (straight theta = 2.2 x 10(-4)), and in the non-coding region 1 in 108 bp (straight theta = 4.4 x 10(-4)), respectively].

Africa↗

PubMed1999

Regulation of the genes for 11beta-hydroxysteroid dehydrogenase type 1 and type 2 in the kidney of the Dahl rat.

BACKGROUND: An isoenzyme of 11beta-hydroxysteroid dehydrogenase (11beta-HSD), 11beta-HSD-2 confers aldosterone specificity on the mineralocorticoid receptor (MR) and is found collocated in renal cortical collecting duct cells with the MR. To investigate whether the salt sensitivity of the Dahl salt-sensitive (S) rat is due to 11beta-HSD deficiency, we measured 11beta-HSD-1 and 11beta-HSD-2 mRNA levels in the kidneys of Dahl-S and Dahl salt-resistant (R) rats. In addition, we studied the effects of gender, age and dietary sodium on expression of mRNA for the two isoforms. S and R rats were placed on low- or high-sodium (HNa) diets and sacrificed after 33 and 115 days. Rat kidney RNA was isolated and 11beta-HSD-1 and 11beta-HSD-2 mRNA levels were measured on Northern filter hybridization using isoform-specific probes. RESULTS: No strain differences were observed in the mRNA expression of the two isoforms of 11beta-HSD under any of the experimental conditions. No gender or age differences were observed in 11beta-HSD-2 mRNA but HNa diet almost doubled 11beta-HSD-2 mRNA (P<0.0009). 11beta-HSD-1 mRNA levels were consistently higher, more than double, in male rats versus females rats (P<0.0001), and in the 115-day-old rats versus the 33-day-old rats (P<0.0001). Dietary sodium intake did not affect 11beta-HSD-1 mRNA levels. CONCLUSIONS: There is no difference in the expression of the two isoforms of 11beta-HSD in the kidneys of the S and R rats, which might explain the salt sensitivity and higher blood pressure of the S rat. Renal 11beta-HSD-1 mRNA levels are higher in male than in female rats, and in the older rats of both strains. In the kidney, the 11beta-HSD-2 gene is regulated by sodium status but is not affected by gender or age.

11-beta-Hydroxysteroid Dehydrogenases↗

PubMed1999

Phylogenetic analysis of L4-mediated autogenous control of the S10 ribosomal protein operon.

We investigated the regulation of the S10 ribosomal protein (r-protein) operon among members of the gamma subdivision of the proteobacteria, which includes Escherichia coli. In E. coli, this 11-gene operon is autogenously controlled by r-protein L4. This regulation requires specific determinants within the untranslated leader of the mRNA. Secondary structure analysis of the S10 leaders of five enterobacteria (Salmonella typhimurium, Citrobacter freundii, Yersinia enterocolitica, Serratia marcescens, and Morganella morganii) and two nonenteric members of the gamma subdivision (Haemophilus influenzae and Vibrio cholerae) shows that these foreign leaders share significant structural homology with the E. coli leader, particularly in the region which is critical for L4-mediated autogenous control in E. coli. Moreover, these heterologous leaders produce a regulatory response to L4 oversynthesis in E. coli. Our results suggest that an E. coli-like L4-mediated regulatory mechanism may operate in all of these species. However, the mechanism is not universally conserved among the gamma subdivision members, since at least one, Pseudomonas aeruginosa, does not contain the required S10 leader features, and its leader cannot provide the signals for regulation by L4 in E. coli. We speculate that L4-mediated autogenous control developed during the evolution of the gamma branch of proteobacteria.

Base Sequence↗

PubMed1999

[Cloning and expression of tyrosinase gene from Pseudomonas maltophilia in E. coli].

The enzyme tyrosinase, encoded by tyrosinase gene (mel), is responsible for melanin formation. In a shotgun cloning experiment, a SalI-digested DNA fragment coding for tyrosinase was cloned from Pseudomonas maltophilia DNA into plasmid vector (pUC18) to generate the hybrid plasmid (pWSY). The recombinant plasmid imparted the ability of melanin synthesis to an E. coli host (HB101). The foreign DNA fragment (0.7 kb) possessed no recognition sites for BamHI, HindIII, EcoRI or BclI. Hybridization studies confirmed that the small fragment cloned in pWSY was from P. maltophilia DNA. Nucleotide sequence analysis identified an ORF of 504 nt coding tyrosinase. SDS-PAGE analysis also revealed an additional protein of 18 kDa, which was equal to the putative tyrosinase according to the size of mel fragment, was expressed in the E. coli recombinant carrying the plasmid pWSY.

Amino Acid Sequence↗

PubMed1999

Reversal effect of TTD on human multidrug resistant KBV200 cell line.

The reversal effect of TTD (a Chinese medicine) on human multidrug- resistant KBV200 cell line was studied and compared with verapamil (VPL). The chemosensitivity of KBV200 was detected by MTT assay in vitro and the level of MDR1 mRNA of KBV200 was investigated by RT-PCR. The cytotoxicity of TTD to KBV200 and the parent sensitive cell line KB is very low and nearly same with a concentration of 10(-6) mol x L(-1). With the concentration TTD increased VCR cytotoxicity on KBV200, 50% inhibitory concentration (IC50) decreased from 1122.5+/-72.36 mol x L(-1) to 31.76+/-5.4 nmol x L(-1) (p<0.001). It was more effective than VPL was (p<0.01). The combination of low concentration of TTD (10(-8) mol x L(-1)) and VCR (100 nmol x L(-1)) has significantly increased VCR cytotoxicity on KBV200, cell Surviving Fraction decreased from 0.91+/-0.056 to 0.74+/-0.07 (p<0.02). TTD did not inhibit the expression of MDR1 mRNA of KBV200 with the concentration of 10(-6) mol x L(-1). These data indicated that TTD could reverse VCR resistance of KBV200 and may be useful in enhancing the clinical effectiveness of VCR.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1999

[The relationship between cartilage end-plate calcification and disc degeneration: an experimental study].

OBJECTIVE: To study the relationship between cartilage end-plate calcification and intervertebral disc degeneration. METHODS: An experimental model of cervical disc degeneration in rabbits was established by resection of cervical supraspinous and interspinous ligaments and detachment of the posterior paravertebral muscles from cervical vertebrae. Mechanical instability in the cervical spine elicited by this surgical intervention accelerated the process of intervertebral disc degeneration. The degrees of intervertebral disc degeneration were graded morphologically. The thickness of the calcified layer and the uncalcified layer of the cartilage end-plate was measured in each degenerated cervical disc. RESULTS: A positive correlation existed between the thickness of the calcified layer of the cartilage end-plate and the degree of the cervical disc degeneration (r = 0.92). CONCLUSION: The calcification of the cartilage end-plate could initiate and promote intervertebral disc degeneration.

Animals↗

PubMed1999

[Long-term results of surgical treatment of intractable Menière's disease for control of vertigo].

OBJECTIVE: To acquire the long-term (an average of over 10 years follow-up) results of surgical treatment of patients with Meniere's disease for control of vertigo. METHOD: Endolymphatic sac surgery was done in 6 cases (1 case of endolymphatic sac decompression and 5 cases of sac-mastoid shunting) and translabyrinth vestibular neurotomy was operated on 6 cases. RESULT: Complete relief from symptoms of vertigo occurred in the 6 cases through vestibular neurotomy and there were no recurrence in 11-13 years follow-up. Three of 6 cases with endolymphatic sac surgery had complete control of vertigo and were cured clinically. Symptoms of vertigo of the rest 3 cases were effectively controlled. CONCLUSION: Endolymphatic sac surgery and translabyrinth vestibular neurotomy are effective way for control of vertigo of patients with intractable Meniere's disease. Translabyrinth vestibular neurotomy are more effective for control of vertigo for appropriately selected patients.

Adult↗

PubMed1999

[Transantral orbit decompression to malignant ophthalmopathy].

OBJECTIVE: To recognize the indication and the value of transantral orbit decompression to malignant ophthalmopathy. METHOD: 9 eyes of 5 cases undergone transantral orbital decompression from November 1986 to October 1998 were reviewed. RESULT: After 3 months-2 years of follow-up. We found this approach successfully improved visual function of all 5 cases. Average proptosis reduction was 5 mm. The eye lids could be closed in 4 of the 5 cases and the palpebral fissures was decreased 1-2 mm in 1 of the 5 cases. Preoperative exposure keratitis resolved in both of the 2 cases. Diplopia was cured in both of the 2 cases. Secondary glucorna also recovered in both the 2 cases. Disturbance of ocular motility in both of the 2 cases improved postoperatively and preoperative visual acurity worsen also improved in both of the 2 cases. CONCLUSION: It has been suggested that the transantral decompression of the orbit provided a safe, effective therapeutic modality for patients with vision-threatening or major cosmetic problem.

Adult↗

PubMed1999

[The application of basic fibroblast growth factor to auricles of rabbits with compound injury].

OBJECTIVE: To study the role of basic fibroblast growth factor (bFGF) in the repair of irradiation- and surgery-induced auricle trauma. METHODS: The bilateral auricles of New Zealand white rabbits were received surgical trauma and beta-active irradiation(90Sr-90Y), bFGF was then applied to the wound. The efficacy of bFGF on wound healing was compared with the control group. RESULTS: On the 10th day after the trauma, the mean epithelalized area was (34.17 +/- 0.37) mm2 and the mean number of microvessels/high power field was (10.25 +/- 2.34) in the treated group, whereas both were (26.25 +/- 0.20) mm2 and (4.38 +/- 0.92) respectivety in the control group. There was a significant difference between the two groups (P < 0.05). On the 7th and 14th days after the trauma, the mean epithelialized area in the treated group was significantly different from that of the control group. The measurement by the image cytometry showed that the treated group had a mean nuclear peak area value of (38.28 +/- 7.23) micron 2 and the mean S-stage cell value of (31.28 +/- 10.35)%, and those of the control group were (28.02 +/- 8.13) micron 2 and (20.14 +/- 9.46)% respectively. There were significant differences (P < 0.05) between them. CONCLUSION: Application of bFGF can, to a certain extent, accelerate the repair of irradiated and surgically injured soft tissue.

Administration, Topical↗