Search PubMed⌕ Search

Biomedical subjects

W Jiang

Publications and source records attributed to W Jiang.

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

[Pharmacokinetics of pramiracetam in animals].

Pharmacokinetic rules of pramiracetam were studied here. After giving pramiracetam orally to dogs, we drew their blood at various times. The drug concentrations in blood plasma were detected by HPLC. 3p87 program was used to calculate the pharmacokinetic parameters. The time-concentration curve corresponded to one apartment model. T1/2 was about 2.3-3.9 hours in various doses. After pramiracetam was given to rats per os, high concentrations of pramiracetam were detected in the rats' tissues. The kidney had the highest concentration of pramiracetam; the liver had the next highest concentration, and then the intestine, lung, muscle, heart, gonad, spleen and sebum had the high concentration in order. The drug was also detected in the brain. 0.7% of the given dose was excreted in unchanged form in bile in 24 hours. 28.26% and 6.35% were excreted in urine and feces respectively in 72 hours. The plasma protein combining rate detected by the method of balance dialysis was 20.1-22.2%.

Animals↗
PubMed1999

[Study on G487A mutation of the glucose-6-phosphate dehydrogenase gene].

OBJECTIVE: In order to reveal the molecular evolution and ethnic origin and immigration, on the basis of G6PD G487A mutation, and estimate the incidence of the mutation in Bai, Dai, and Han people in Yunnan and Guangxi. METHOD: G6PD deficient individuals were studied by using PCR-RE, PCR-SSCP and DNA sequencing. RESULTS: The G487A mutation in Bai and Dai people was identified for the first time and its relative incidences were 6/66 and 1/52, respectively. The individuals of G6PD G487A mutation showed the features of G6PD clinic type III. No G487A was found in Han people in Guangxi(0/46). CONCLUSION: The G6PD G487A mutation revealed in some ethnic groups of China implies that different national minorities of Chinese may be origined from a common ancestor.

Asian People↗
PubMed1999

[Resection of nerve of wrist combining replacement of lunate with bone cement prosthesis in treatment of Kienbock's disease].

OBJECTIVE: There are various methods used to treat the Kienbock's disease with various outcomes. This study investigated the effect of combining acrylic lunate prosthesis replacement with resection of articular branches to wrist from anterior and dorsal interosseous nerve. METHODS: From January 1992 to January 1997, six cases were included. All of the patients were in stage III according to Lichtman's classification. Besides replacement of the acrylic lunate prosthesis, segment of the pure sensory branches from anterior and posterior interosseous nerves were resected. RESULTS: Follow-up for 10 to 54 months (an average of 32 months) the pain was relieved in all patients except one. The range of movement of wrists were as followings: The extension of the wrist was 20 to 35 degrees (an average of 26 degrees) and flexion was 20 to 35 degrees (an average of 32 degrees). There was no improvement in radial and ulnar deviation. CONCLUSION: Lunate prosthesis replacement combined with resection of articular branches to wrist resulted in a painless wrist and was a satisfactory method.

Adolescent↗
PubMed1999

[Computer-aided legal medical examination of body surface].

This paper provides a package of automatic and semi-automatic methods for computing the area of different kinds of body surface injuries. Compared with traditional methods, these processes of examination are faster and the conclusions are more precise and objective. Also presented are the authors classify the items into many types by standards which are necessary to let computer draw conclusions automatically. This software is conducive to improvement in work efficiency and convenience for judicial supervision.

Algorithms↗
PubMed1999

[Determination of conversion of asymmetric hydrosilylation of acetophenone by gas chromatography].

A gas chromatographic method to determine the conversion of asymmetric hydrosilylation of acetophenone has been established. The gas chromatographic conditions were as follows: column, 10% PEG20M on white 102 support (DMCS), 1 m x 2 mm i.d. stainless-steel column; column temp., 160 degrees C; injector temp., 200 degrees C; thermal conductivity detector temp., 190 degrees C; carrier gas H2 with flow rate of 50 mL/min. The results show that the method is simple and rapid, and has good reproducibility. The coefficient of variation of the method was less than 1% (n = 6). The results were also confirmed with 1HNMR.

Acetone↗
PubMed1999

[Sugar phosphorylation activities in acetogenic bacteria].

Seven acetogenic bacteria (Acetitomaculum ruminis, Acetobacterium woodii, Eubacterium limosum as well as isolates A2, A4, A10 and H3HH) were tested for PEP- and ATP-dependent phosphorylation of glucose and 2-deoxyglucose. Although all organisms had detectable phosphorylation activity, substantial variation existed in the rates of both PEP- and ATP-dependent phosphorylation. Isolate Alo had the highest rate of PEP-dependent phosphorylation of 11.62 nmol.L-1.mg-1.min-1. Isolate A10, H3HH as well as E. limosum most likely have a glucose phosphotransferase system(PTS). In contrast, A ruminis, A. woodii and isolate A2, A4 had PEP-dependent glucose phosphorylation rates very similar to control rates, suggesting the lack of PTS activity. The rates of ATP-dependent glucose phosphorylation were higher than PEP-dependent phosphorylation in all organisms surveyed. However, substantial variation existed in the rates of ATP-dependent glucose phosphorylation. The glucose PTS of isolates A10 and H3HH were induced by the presence of extracellular glucose. Moreover, the specific activity of the glucose PTS of both isolates increased as cultures progressed from the early log to late log phase of growth. ATP- and PEP-dependent maltose and sucrose phosphorylation was detected in isolates A10 and H3HH. Although activity was detected in both isolates(A10 and H3HH), the rate of activity varied considerably, depending on the sugar and organism tested.

Acetic Acid↗
PubMed1999

[Protective effects of leishmanial antigens against Leishmania infantum infection in Lagurus lagurus].

AIM: To determine the protective effect of leishmanial surface antigens against experimental visceral leishmaniasis in Lagurus lagurus caused by Leishmania infantum. METHODS: Recombinant surface protein (rGP63) and lipophosphoglycan (LPG) of Leishmania were used with Corinebacterium parum vaccine as ajuvant to immunize Lagurus lagurus against a challenge with virulent strain of Leishmania infantum. The efficacy of immunoprotection was observed. RESULTS: When challenged with up to 2 x 10(7) promastigotes, the number of LD on the liver printing sections in the rGP63 + LPG + CP immunised animals was significantly decreased, the parasite reduction rate being 89.79%. LPG + CP gave a parasite reduction rate of 60.6% and rGP63/beta-galactosidase fusion protein + CP showed a parasite reduction rate of 42.45%. Purified rGP63 showed no protection. Immunization with rGP63 + LPG + CP followed by challenge inifection with 1 x 10(6), 5 x 10(6) and 1 x 10(7) promastigotes also showed significantly reduced infection rates. CONCLUSION: A combination of rGP63 + LPG + CP antigens could provide significant immunoprotection against L. infantum challenge in L. lagurus.

Animals↗
PubMed1999

[The postoperative complications and management of excimer laser in situ keratomilleusis].

OBJECTIVE: To evaluate the safety of excimer laser in situ keratomilleusis (LASLK) METHODS: The postoperative complications in 699 eyes of LASIK were observed and statistically analyzed. RESULTS: The haze, halo, growth of corneal epithelium under valve, the foreign body under valve, the fold of corneal valve, infection, decentralization, irregular astigmatism, valvular damage, low contrast sensibility, undercorrection and over correction, the psychological dysopia, glaucoma, fluctuating visual acuity and the loss of the best corrected visual acuity were found. CONCLUSION: LASIK has it's advantages of accurate manipulation, extensive range of correction and rapid recovery, but some of the complications resulting from this operation are so difficult to treat that careful consideration should be given before using this technique.

Adolescent↗
PubMed1999

[Differences in furosemide-induced changes of summating potential and endocochlear potential in guinea pigs].

OBJECTIVE: To investigate the physiological properties of summating potential (SP) and to compare the different changes between SP and endocochlear potential (EP) induced by Furosemide in guinea pigs. METHODS: SP in response to clicks with alternative polarities at 105 dB peSPL was recorded from a electrode in the facial nerve canal. EP was measured with a glass microelectrode in the basal turn of the cochlea. SP and EP were observed simultaneously and continuously after injection of Furosemide or the solution of Furosemide-bovine serum albumin injected into the jugular vein of the animal. RESULTS: Before furosemide application, only SP could be recorded with small or without +SP. After furosemide injection, EP declined dramatically followed by reduction of the -SP which quickly vanished, while +SP appeared or the amplitude increased. When EP recovered to a certain level, +SP disappeared or dramatically decreased and then -SP reappeared. The amplitude of -SP increased progressively with EP recovery. Both -SP and EP recovered to the pre-injected level in 60 min after the furosemide application. CONCLUSION: The results suggest that Furosemide induced distinct changes of -SP and +SP, the two components of SP. The changes of -SP amplitude was consistent with that of the EP value, while the changes of +SP amplitude were contrary to that of the EP value.

Animals↗
PubMed1999

[Fluorescence enhancement of the dysprosium-sulfosalicylic acid system by lanthanum and its application].

A fluorescence enhancement produced by adding lanthanum(III) to dysprosium-sulfosalicylic acid system was observed. La3+ enhanced the fluorescence intensity by two orders of magnitude compared with the system without La3+. The system was used for the determination of trace amount of dysprosium in the range of 3.0 x 10(-7)-1.0 x 10(-5) mol/dm3, and the detection limit was 8.0 x 10(-8) mol/dm3. The procedure was applied to the determination of dysprosium in synthetic rare earth samples and standard rare earth samples with satisfactory results.

English Abstract↗
PubMed1998

Sequence of a second gene encoding bovine submaxillary mucin: implication for mucin heterogeneity and cloning.

Secreted epithelial mucins are extremely large and heterogeneous glycoproteins. We report the 5 kilobase DNA sequence of a second gene, BSM2, which encodes bovine submaxillary mucin. The determined nucleotide and deduced amino acid sequences of BSM2 are 95.2% and 92. 2% identical, respectively, to those of the previously described BSM1 gene isolated from the same cow. Further, the five predicted protein domains of the two genes are 100%, 94%, 93%, 77%, and 88% identical. Based on the above results, we propose that expression of multiple homologous core proteins from a single animal is a factor in generating diversity of saccharides in mucins and in providing resistance of the molecules to proteolysis. In addition, this work raises several important issues in mucin cloning such as assembling sequences from seemingly overlapping clones and deducing consensus sequences for nearly identical tandem repeats.

Amino Acid Sequence↗
PubMed1998

Four distinct regions in the auxiliary domain of heterogeneous nuclear ribonucleoprotein C-related proteins.

A 306 amino acid sequence deduced from a rabbit bladder cDNA is 98% identical to the human heterogeneous nuclear ribonucleoprotein (hnRNP) C2. The sequence comparison of the hnRNP C-related proteins reveals four distinct regions in the C-terminal auxiliary domain. The region next to the N-terminal RNA-binding domain is variable in length. Following the variable region, a basic region and a leucine zipper are conserved in all hnRNP C-related proteins including mouse and human Raly. Several Lys-Ser-Gly repeats are present in the basic region of the hnRNP C proteins. The C-terminal region is more divergent between hnRNP C and Raly. Signature sequences and possible functions are proposed for the different regions of the hnRNP C proteins.

Amino Acid Sequence↗
PubMed1998

Arrangement of the multicopy H+-translocating subunit c in the membrane sector of the Escherichia coli F1F0 ATP synthase.

The multicopy subunit c of the H+-transporting F1F0 ATP synthase of Escherichia coli is thought to fold across the membrane as a hairpin of two hydrophobic alpha-helices. The conserved Asp61, centered in the second transmembrane helix, is essential for H+ transport. In this study, we have made sequential Cys substitutions across both transmembrane helices and used disulfide cross-link formation to determine the oligomeric arrangement of the c subunits. Cross-link formation between single Cys substitutions in helix 1 provided initial limitations on how the subunits could be arranged. Double Cys substitutions at positions 14/16, 16/18, and 21/23 in helix 1 and 70/72 in helix 2 led to the formation of cross-linked multimers upon oxidation. Double Cys substitutions in helix 1 and helix 2, at residues 14/72, 21/65, and 20/66, respectively, also formed cross-linked multimers. These results indicate that at least 10 and probably 12 subunits c interact in a front-to-back fashion to form a ring-like arrangement in F0. Helix 1 packs at the interior and helix 2 at the periphery of the ring. The model indicates that the Asp61 carboxylate is centered between the helical faces of adjacent subunit c at the center of a four-helix bundle.

Adenosine Triphosphate↗
PubMed1998

Subunit organization and structure in the F0 sector of Escherichia coli F1F0 ATP synthase.

In this review, we summarize recent work from our laboratory which establishes the topology and nearest neighbor organization of subunits in the F0 sector of the H+ transporting ATP synthase of Escherichia coli. The E. coli F0 sector is composed of three subunits in an a1b2c12 stoichiometric ratio. Crosslinking experiments with genetically introduced Cys establish a ring-like organization of the 12 c subunits with subunits a and b lying to the outside of the ring. The results are interpreted using an atomic resolution structural model of monomeric subunit c in a chloroform-methanol-water (4:4:1, v/v/v) solution, derived by heteronuclear NMR (M.E. Girvin, F. Abildgaard, V. Rastogi, J. Markley, R.H. Fillingame, in press). The crosslinking results validate many predictions of the structural model and confirm a front-to-back-type packing of two subunit c into a functional dimer, as was first predicted from genetic studies. Aspartyl-61, the proton translocating residue, lies at the center of the four transmembrane helices of the functional dimer, rather than at the periphery of the subunit c ring. Subunit a is shown to fold with five transmembrane helices, and a functionally important interaction of transmembrane helix-4 with transmembrane helix-2 of subunit c is established. The single transmembrane helices of the two subunit b dimerize in the membrane. The structure of the transmembrane segment of subunit b is predicted from the NMR structure of the monomeric peptide.

Dimerization↗
PubMed1998

Interacting helical faces of subunits a and c in the F1Fo ATP synthase of Escherichia coli defined by disulfide cross-linking.

Subunits a and c of Fo are thought to cooperatively catalyze proton translocation during ATP synthesis by the Escherichia coli F1Fo ATP synthase. Optimizing mutations in subunit a at residues A217, I221, and L224 improves the partial function of the cA24D/cD61G double mutant and, on this basis, these three residues were proposed to lie on one face of a transmembrane helix of subunit a, which then interacted with the transmembrane helix of subunit c anchoring the essential aspartyl group. To test this model, in the present work Cys residues were introduced into the second transmembrane helix of subunit c and the predicted fourth transmembrane helix of subunit a. After treating the membrane vesicles of these mutants with Cu(1, 10-phenanthroline)2SO4 at 0 degrees, 10 degrees, or 20 degreesC, strong a-c dimer formation was observed at all three temperatures in membranes of 7 of the 65 double mutants constructed, i.e., in the aS207C/cI55C, aN214C/cA62C, aN214C/cM65C, aI221C/cG69C, aI223C/cL72C, aL224C/cY73C, and aI225C/cY73C double mutant proteins. The pattern of cross-linking aligns the helices in a parallel fashion over a span of 19 residues with the aN214C residue lying close to the cA62C and cM65C residues in the middle of the membrane. Lesser a-c dimer formation was observed in nine other double mutants after treatment at 20 degreesC in a pattern generally supporting that indicated by the seven landmark residues cited above. Cross-link formation was not observed between helix-1 of subunit c and helix-4 of subunit a in 19 additional combinations of doubly Cys-substituted proteins. These results provide direct chemical evidence that helix-2 of subunit c and helix-4 of subunit a pack close enough to each other in the membrane to interact during function. The proximity of helices supports the possibility of an interaction between Arg210 in helix-4 of subunit a and Asp61 in helix-2 of subunit c during proton translocation, as has been suggested previously.

Amino Acid Substitution↗
PubMed1998

A directly spliced exon 10-containing CD44 variant promotes the metastasis and homotypic aggregation of aggressive non-Hodgkin's lymphoma.

Variants of the CD44 cell-surface adhesion molecule include additional sequences encoded by combinations of exons from the membrane proximal domain (exons 6-14). Preliminary studies suggest that these additional variable membrane proximal sequences may alter the ligand specificity, glycosylation, and biologic function of CD44. In earlier studies, we found that primary extranodal and widely disseminated aggressive non-Hodgkin's lymphomas (NHLs) and normal activated B cells expressed a directly spliced exon 10-containing variant (CD44ex10), whereas normal resting B cells expressed larger exon 10-containing variants (CD44ex10-14 and CD44ex7-14). To obtain additional information regarding the function of exon 10-containing CD44 variants in aggressive NHL, we generated aggressive NHL transfectants that expressed CD44ex10, CD44ex10-14, CD44ex7-14, the standard CD44 isoform (CD44H), or vector alone, and evaluated the local tumorogenicity, aggregation, and metastatic potential of these transfectants. CD44ex10 aggressive NHL transfectants were more likely to cause local tumor formation in nude mice than transfectants expressing the larger exon 10-containing variants, CD44H, or vector alone. In addition, cell suspensions derived from CD44ex10 local tumors exhibited far greater homotypic aggregation than those obtained from other CD44 or vector-only local tumors. In nude mice that received CD44ex10 transfectants, distant metastases were also significantly more likely to develop than in animals that were given either the CD44ex10-14, CD44ex7-14, CD44H, or vector-only transfectants. These data provide the first evidence that the directly spliced exon 10-containing CD44 variant (CD44ex10) has a unique biologic function in aggressive NHL.

Alternative Splicing↗