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Biomedical subjects

Y Ma

Publications and source records attributed to Y Ma.

At least 163 records · Page 9Linked to original sources
PubMed2001

Effect of acupuncture on plasmic levels of insulin, glucagon and hypercoagulability in NIDDM complicated by acute cerebral infarction.

Twenty-one cases of acute cerebral infarction secondary to NIDDM were treated with acupuncture and conventional therapy, and compared with 16 cases treated with conventional therapy alone. The results showed that acupuncture was more effective in reducing insulin and glucagon levels (P < 0.001) and improving hypercoagulability (P < 0.05) of blood.

Acupuncture Therapy↗
PubMed2001

[The effects of iron supplementation on auditory brain-stem response with iron deficiency anemia in rats].

OBJECTIVE: To evaluate the therapeutic methods of sensorineural hearing loss with iron deficiency anemia and their effects. METHOD: Sixty-eight Wistar rats were randomly divided into 3 groups: Group A (iron deficiency group A) 24 rats, group B (iron deficiency group B) 24 rats and group C (control group) 20 rats. Group A and B were fed with iron deficiency diet for 6 weeks. By analyzing ABR and DPOAE, hearing loss was detected in group A and B. Then, group A was given iron supplementation diet and hyperbaric oxygen therapies, and group B was given iron supplementation diet only. RESULT: The auditory thresholds and period latencies (PL) of I waves of ABR and DPOAE amplitude in 2 kHz and 3 kHz within group A and B were significantly different before and after treatment (P < 0.05). But the effects of treatment between these two groups had not significant differences (P > 0.05). CONCLUSION: It suggested that good results can be obtained by early iron supplementation in iron deficiency hearing loss cases. Hyperbaric Oxygen therapy may not be necessary.

Anemia, Iron-Deficiency↗
PubMed2001

[Gentamicin for the transtympanic treatment of Menière's disease].

OBJECTIVE: This study described the method and efficacy of intratympanic gentamicin injection for obstinated, incapacitated Meniere's disease. METHOD: It is a prospective study. Patients selected had classic unilateral Meniere's disease. All had preinjection audiometric and electronystagmography. Injection was accepted every two or three days. It is important to direct the therapy by observing the symptoms closely and checking the audiometric and electronystagmography whenever necessary. RESULT: All the 12 cases undergone the treatment were followed up from 2 to 9 years. According to the criterion of Chinese Medical Association of ENT, the vertigo of Meniere's disease was evaluated. A (completed control): 10 cases; B (largely control): 2 cases. 4 cases said their tinnitus disappeared and 3 cases felt it improved. Hearing loss and vibration illusion vision are two complications. CONCLUSION: The methods is simple, useful and safe, the effect of which is similar to vestibular neurectomy. It is the first choice therapy suitable to Meniere's disease patients, which symptoms keep unchanged after medical treatment or failed in surgery.

Adult↗
PubMed2001

[Cloning and expression of two garlic virus coat protein genes].

The coat protein(CP) genes of garlic mosaic virus(GMVc) and garlic latent virus(GLVc) isolated from garlic(Allium) plants in Tianjin, China, were amplified from an established cDNA library by PCR method and subsequently expressed in E. coli. using the pET-30a expression system. The determined sequences of GMVc and GLVc CP genes show that the complete GMVc CP gene has 867 nucleotides encoding 289 amino acids. It has 88.5% and 97.2% homology, at the levels of nucleotide and amino acid, respectively, to a reported GMV, indicating that it belongs to Potyvirus. The complete GLVc CP gene has 885 nucleotides coding for 294 amino acids. It has 73.6% and 90.9% homologous percents, in nucleotide and amino acid, respectively, compared to a previously reported GLV, suggesting that it is a member of Carlavirus. The expressed products presented in inclusion body and were analyzed by SDS-PAGE. The molecular weights of GMVc and GLVc CPs appear in 32 kD and 34 kD size, respectively, which are consistent with the deduced sizes of these two CPs. These data will be virtually significant to the further investigation of viruses infecting parlic plant, the control of garlic virus diseases and the production of virus-freed garlic plants.

Capsid Proteins↗
PubMed2001

[Effect of pH on the permeability of timolol maleate across isolated rabbit cornea].

AIM: To study the effect of pH on the transcorneal permeability of timolol maleate (TM). METHODS: The apparent distribution coefficients of TM were determined. The permeability of TM across isolated rabbit cornea was measured using in vitro method at various pH. RESULTS: The partition coefficient and pKa of TM were 63.63 and 9.17 respectively. At neutral pH, the apparent permeation coefficient of TM was 1.43 x 10(-5) cm.s-1. When the pH varied from 6.65 to 9.20, the cumulative amount for timolol transcorneal penetration increased 1.3 times and the lag time decreased more than 19-folds. The calculated permeability coefficients of ionized and un-ionized timolol were 1.29 x 10(-5) cm.s-1 and 4.22 x 10(-5) cm.s-1, respectively. CONCLUSION: Timolol penetrated corneal membrane mainly as free base by intracellular pathway, and corneal epithelium was the rate-limiting barrier.

Animals↗
PubMed2001

[Effect on proliferation and apoptosis of human lingual carcinoma cells cotransfected by bax and p53 genes].

OBJECTIVE: To investigate the effects on proliferation and apoptosis of human cancerous cells cotransfected by bax apoptosis-inducing gene and p53 tumor suppressor gene. METHODS: The chimeric gene pSV-CIP-bax-CAT was constructed in which bax gene was flanked upstream by a 217 bp fragment(+822(-)+1093) of the first intron and a 317 bp promoter fragment of human a 1(I) collagen gene. Human lingual carcinoma cell line Tca 8113 (LCC) in culture was respectively transfected with pSV-CIP-bax-CAT, and cotransfected with pSV-p53-CAT and pSV-CIP-bax-CAT by using the transfection reagent DOSPER. RESULTS: Immuno-slot blot and ELISA demonstrated that the expression of bax and p53 genes increased remarkably in the transfected and cotransfected LCC, compared with the controls (LCC transfected with pSV-CIP-CAT and LCC). MTT colorimetric assay, TUNEL fluorenscence microscopy and flow cytometry showed that foreign bax or p53 gene inhibited the LCC growth and induced apoptosis (23.9% and 26.1% of inhibitory rate by bax gene and p53 plus bax genes respectively). CONCLUSION: The ectopic expression of the bax gene in the LCC promoted by the cis-acting elements of human a1 (I)collagen gene has obviously synergistic effect on the proliferation and apoptosis of the LCC contransfected with p53 gene plus bax gene for 48 hours.

Apoptosis↗
PubMed2001

[Endoscopic surgery for nasal inverted papilloma].

OBJECTIVE: To study and perfect the endoscopic surgery for nasal inverted papilloma(IP) and to decrease the recurrence after operation. METHODS: Forty-seven cases who were diagnosed as nasal IP were divided into two groups according to the tumor extension and operated upon and observed for 12-40 months (average 24.6 months). 51% of all cases had been operated on for 1-3 times before the treatment. Thirty-six cases in which the tumor had invaded the lateral nasal wall, middle meatus, partial or total ethmoid and/or sphenoid and infiltrated around the natural ostium of the maxillary sinus had performed transnasal endoscopic surgical procedures(TNESP). Another group (9 cases) in which involvement of the IP had further extended, into the maxillary sinus, had been treated by combination transnasal and Caldwell-Luc endoscopic surgical procedures (CTESP). In order to decrease bleeding during the operation, the body and bases of the IP were irradiated with YAG laser. The tumor was removed using the shaver system. The bony attachment of the IP and neighboring tissues were irradiated in all cases. RESULTS: Forty-five (95.7%) cases were not recurrent. The recurrence of the IP was identified in two cases (4.3%). But in 6 cases (12.8%), during postoperative follow-up management (1-3 months postoperatively) small mass of the IP (pathologically identified) were observed and removed and irradiated with YAG laser immediately. The recurrence was not observed in the one year follow-up period. CONCLUSION: Endoscopic surgical technique combining the irradiation of YAG laser and the application of shaver system is recommended. This procedure was effective and led to a decreased recurrence rate.

Adolescent↗
PubMed2001

Expression and glycosylation of rotavirus strain SA11 VP4 protein in a recombinant adenovirus.

OBJECTIVE: Using a recombinant human adenovirus to express modified VP4 gene of rotavirus SA11 strain. METHODS: A whole VP4 gene was obtained with PCR and induced the signal peptide at the gene N terminal. The chimera gene was cloned into pCMV plasmid that consists of human cytomegalovirus promoter, and then the gene was cloned to the transfer vector of human adenovirus type 5. Homologous recombination was performed by co-transfection to 293 cell lines with recombinant plasmid and viral genome using CaPO4 precipitation. RESULTS: No mutation was found in the whole VP4 gene sequence of 2362 base pair. The expressed product in recombinant adenovirus was confirmed to be specific and more antigenicity by indirect immunofluorescence assay. Both the Western blot and immunoprecipitation assay showed that the molecular mass of the expressed protein was higher than the wild type VP4 protein, and that the modified product was corresponding to a glycosylation of VP4 protein. CONCLUSION: To modify the target gene might be an effective method to enhance the stability, antigenicity and immunogenicity of expressed protein.

Adenoviruses, Human↗
PubMed2001

[Experimental study on bioglass application in extending alveolar bone crest in rabbit].

OBJECTIVE: To observe the effect of Bioglass guiding bone regeneration and forming normal new bone in extending alveolar bone crest by surgery. METHODS: Thirty-six rabbits were randomly divided into three groups. The first group was treated with Bioglass and the second with hudroxyapectite (HA). The third group was control group. At 4 8 12 weeks after surgery, the condition of bone regeneration was observed with radiological and pathological methods. RESULTS: Statistical analysis showed that there was a significant difference between the third group and the other two groups (P<0.05). In addition, Bioglass can guide bone regeneration faster than hydroxyapatite, and it can be substituted by new bone to form completely normal bone. CONCLUSION: Since Bioglass is more effective than HA in guiding bone regeneration, it is an ideal bone graft substitute.

English Abstract↗
PubMed2001

[The effects of E1A gene on the proliferation and the cell cycle of human lung adenoma cell line].

OBJECTIVE: To investigate the effects of E1A gene on the proliferation rate and the cell cycle of human lung adenoma cell line. METHODS: The characteristics of human adenoma cells transfected and untransfected with E1A gene were studied including the cell growth rate in vitro, the tumorigenicity in nude mouse, and cell cycle analyzed by flow cytometry. The level of P16, P21, P53 and cyclinB1 was assayed using Western blot. RESULTS: The proliferation rate in vitro and the tumorigenicity in vivo of the human lung adenoma cells transfected with E1A gene (Anip973-E1A) were suppressed and cell cycle was retarded at G2/M phase. There was no significant change in the level of P16, P21 and P53, however, the level of cyclinB1 diminished remarkedly. CONCLUSIONS: E1A gene could suppress the proliferation of human adenoma cells in vitro and in vivo. The expression level of cyclinB1, one of the key G2/M checkpoint modulators, was inhibited by E1A, resulting in retardation at G2/M phase. It may be one of the mechanisms of E1A as a tumor-suppressing gene.

Adenovirus E1A Proteins↗
PubMed2000

Haplotypes of four novel single nucleotide polymorphisms in the nicotinic acetylcholine receptor beta2-subunit (CHRNB2) gene show no association with smoking initiation or nicotine dependence.

Several types of evidence, including experiments with mice that lack the nicotinic acetylcholine receptor beta2-subunit gene (CHRNB2), have suggested that a beta2-containing nicotinic receptor is necessary for at least some of the reinforcing properties of nicotine. However, sequence variations in CHRNB2 have not been reported, and its role in influencing human smoking behavior and nicotine dependence is not known. We screened most of the introns and exons and found five novel single nucleotide polymorphisms (SNPs). We tested four of these SNPs in three large, carefully selected samples: nonsmokers (n = 317) and regular smokers low levels of nicotine dependence (ND, n = 238), or smokers with high-ND (n = 317). None of the four polymorphisms we tested, nor their estimated haplotypes, were associated with smoking initiation or progression to nicotine dependence.

DNA↗
PubMed2000

Mutations in the N-terminal cooperativity domain of gene 32 protein alter properties of the T4 DNA replication and recombination systems.

The gene 32 protein (gp32) of bacteriophage T4 is the essential single-stranded DNA (ssDNA)-binding protein required for phage DNA replication and recombination. gp32 binds ssDNA with high affinity and cooperativity, forming contiguous clusters that optimally configure the ssDNA for recognition by DNA polymerase or recombination enzymes. The precise roles of gp32 affinity and cooperativity in promoting replication and recombination have yet to be defined, however. Previous work established that the N-terminal "B-domain" of gp32 is essential for cooperativity and that point mutations at Arg(4) and Lys(3) positions have varying and dramatic effects on gp32-ssDNA interactions. Therefore, we examined the effects of six different gp32 B-domain mutants on T4 in vitro systems for DNA synthesis and homologous pairing. We find that the B-domain is essential for gp32's stimulation of these reactions. The stimulatory efficacy of gp32 B-domain mutants generally correlates with the hierarchy of relative ssDNA binding affinities, i.e. wild-type gp32 approximately R4K > K3A approximately R4Q > R4T > R4G gp32-B. However, the functional defect of a particular mutant is often greater than can be explained simply by its ability to saturate the ssDNA at equilibrium, suggesting additional defects in the proper assembly and activity of DNA polymerase and recombinase complexes on ssDNA, which may derive from a decreased lifetime of gp32-ssDNA clusters.

Bacteriophage T4↗
PubMed2000

Oncogenic transformation by the FOX protein Qin requires DNA binding.

Some functions of the Qin oncoprotein are not dependent on DNA binding. In order to test the requirement for DNA binding in Qin-induced oncogenic transformation, site directed mutations were introduced in the winged helix (WH) DNA binding domain of the Qin protein. In cellular Qin (c-Qin), the glycine at position 233 was either deleted or substituted with the amino acids aspartic acid, alanine, glutamic acid, asparagine, proline or lysine. The same position carries aspartic acid in the viral Qin protein (v-Qin). The adjacent residues, threonine 232 and lysine 234, were separately mutated to proline. Several additional amino acid substitutions believed to be involved in DNA contacts were introduced at the following c-Qin positions: asparagine 189, histidine 193, serine 196 or arginine 236. Most of the substitutions reduced DNA binding of Qin, one mutation, H193A, completely abolished DNA binding, and another mutation, T232P, increased DNA binding affinity. Mutant H193A failed to transform chicken embryo fibroblasts (CEF), all other mutants, even those showing minimal DNA binding, retained oncogenicity for CEF. The efficiencies of focus formation induced by these mutant proteins in cell culture were not significantly different from that of wild type. However, the rate of focus development and the size of foci induced by the Qin mutants were greater with strong DNA binders than with weak DNA binders. Transdominant negative constructs consisting of the winged helix domain of cQin or v-Qin interfered with focus formation induced by full length Qin proteins. These results suggest that DNA binding is a prerequisite for transformation by Qin, and strong DNA binding is related to accelerated transformation in CEF.

Amino Acid Sequence↗
PubMed2000

High-throughput single-molecule spectroscopy in free solution.

A high-speed high-throughput single-molecule imaging technique for identifying molecules in free solution based on differences in their fluorescence emission spectra is presented. Unlike previous reports, the entire spectrum, rather than selected wavelengths through optical filters, is recorded. Furthermore, the millisecond data acquisition time means that the molecules do not need to be immobilized or spatially confined. In one example, individual lambdaDNA molecules labeled with YOYO-I, POPO-III, or a combination of the two dyes can be distinguished from one another. In another example, biotinylated 2.1-kb DNA labeled with YOYO-I was reacted with avidin-conjugated R-phycoerythrin. The two different reactant molecules and the product molecule can be simultaneously imaged and identified by their spectroscopic characteristics. This technique can therefore be used for screening single molecules for disease markers and for monitoring individual molecular interactions at a rate of thousands of molecules per second.

Biotinylation↗
PubMed2000

Identification and functional expression of four isoforms of ATPase II, the putative aminophospholipid translocase. Effect of isoform variation on the ATPase activity and phospholipid specificity.

ATPase II, a vanadate-sensitive and phosphatidylserine-dependent Mg(2+)-ATPase, is a member of a subfamily of P-type ATPase and is presumably responsible for aminophospholipid translocation activity in eukaryotic cells. The aminophospholipid translocation activity plays an important physiological role in the maintenance of membrane phospholipid asymmetry that is observed in the plasma membrane as well as the membranes of certain cellular organelles. While the preparations of ATPase II from different sources share common fundamental properties, such as substrate specificity, inhibitor spectrum, and phospholipid dependence, they are divergent in several characteristics. These include specific ATPase activity and phospholipid selectivity. We report here the identification of four isoforms of ATPase II in bovine brain. These isoforms are formed by a combination of two major variations in their primary sequences and show that the structural variation of these isoforms has functional significance in both ATPase activity and phosholipid selectivity. Furthermore, studies with the phosphoenzyme intermediate of ATPase II and its recombinant isoforms revealed that phosphatidylserine is essential for the dephosphorylation of the intermediate. Without phosphatidylserine, ATPase II would be accumulated as phosphoenzyme in the presence of ATP, resulting in the interruption of its catalytic cycle.

Amino Acid Sequence↗
PubMed2000

Cutting edge: repurification of lipopolysaccharide eliminates signaling through both human and murine toll-like receptor 2.

Toll-like receptor (TLR) 2 has recently been associated with cellular responses to numerous microbial products, including LPS and bacterial lipoproteins. However, many preparations of LPS contain low concentrations of highly bioactive contaminants described previously as "endotoxin protein," suggesting that these contaminants could be responsible for the TLR2-mediated signaling observed upon LPS stimulation. To test this hypothesis, commercial preparations of LPS were subjected to a modified phenol re-extraction protocol to eliminate endotoxin protein. While it did not influence the ability to stimulate cells from wild-type mice, repurification eliminated the ability of LPS to activate cells from C3H/HeJ (Lpsd) mice. Additionally, only cell lines transfected with human TLR4, but not human or murine TLR2, acquired responsiveness to both re-extracted LPS and to a protein-free, synthetic preparation of lipid A. These results suggest that neither human nor murine TLR2 plays a role in LPS signaling in the absence of contaminating endotoxin protein.

Animals↗
PubMed2000

Functional interactions between Drosophila bHLH/PAS, Sox, and POU transcription factors regulate CNS midline expression of the slit gene.

During Drosophila embryogenesis the CNS midline cells have organizing activities that are required for proper elaboration of the axon scaffold and differentiation of neighboring neuroectodermal and mesodermal cells. CNS midline development is dependent on Single-minded (Sim), a basic-helix-loop-helix (bHLH)-PAS transcription factor. We show here that Fish-hook (Fish), a Sox HMG domain protein, and Drifter (Dfr), a POU domain protein, act in concert with Single-minded to control midline gene expression. single-minded, fish-hook, and drifter are all expressed in developing midline cells, and both loss- and gain-of-function assays revealed genetic interactions between these genes. The corresponding proteins bind to DNA sites present in a 1 kb midline enhancer from the slit gene and regulate the activity of this enhancer in cultured Drosophila Schneider line 2 cells. Fish-hook directly associates with the PAS domain of Single-minded and the POU domain of Drifter; the three proteins can together form a ternary complex in yeast. In addition, Fish can form homodimers and also associates with other bHLH-PAS and POU proteins. These results indicate that midline gene regulation involves the coordinate functions of three distinct types of transcription factors. Functional interactions between members of these protein families may be important for numerous developmental and physiological processes.

Animals↗