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W Deng

Publications and source records attributed to W Deng.

At least 55 records · Page 3Linked to original sources
PubMed1999

Alpha coefficient of dose-response for chromosome translocations measured by FISH in human lymphocytes exposed to chronic 60Co gamma rays at body temperature.

PURPOSE: To measure the alpha coefficient, the initial slope of the translocation dose-response curve, for 60Co gamma-rays in human lymphocytes. MATERIALS AND METHODS: Human lymphocytes were exposed to 0, 0.32, 0.62 and 0.92 Gy of chronic 60Co gamma-rays under conditions that reduce the metabolic stress to the cells. Chromosome translocation frequencies were measured using fluorescence in situ hybridization with a whole-chromosome probe cocktail specific for chromosomes 1, 2, 4 (orange) and 3, 5, 6 (green). RESULTS: A total of 72,383 metaphases were analysed (33,429 in exposed cells) in two individuals. The shape of the dose-response curves for translocations was linear, and alpha coefficient was measured as 0.024 +/- 0.002 translocations per cell per Gy for the combined data for two 24 year old male donors. CONCLUSION: The alpha coefficients measured after chronic exposure were in good agreement with that reported in the literature for acute, low-dose exposure of human lymphocytes to 60Co gamma-rays.

Adult↗
PubMed1999

A targeted gene silencing technique shows that Drosophila myosin VI is required for egg chamber and imaginal disc morphogenesis.

We report that Drosophila unconventional myosin VI, encoded by Myosin heavy chain at 95F (Mhc95F), is required for both imaginal disc and egg chamber morphogenesis. During oogenesis, Mhc95F is expressed in migrating follicle cells, including the border cells, which migrate between the nurse cells to lie at the anterior of the oocyte; the columnar cells that migrate over the oocyte; the centripetal cells that migrate between the oocyte and nurse cells; and the dorsal-anterior follicle cells, which migrate to secrete the chorionic appendages. Its function during development has been studied using a targeted gene silencing technique, combining the Gal4-UAS targeted expression system and the antisense RNA technique. Antibody staining shows that the expression of myosin 95F is greatly decreased in follicle cells when antisense Mhc95F RNA is expressed. Interfering with expression of Drosophila myosin VI at various developmental stages frequently results in lethality. During metamorphosis it results in adult flies with malformed legs and wings, indicating that myosin VI is essential for imaginal disc morphogenesis. During oogenesis, abnormal follicle cell shapes and aberrant follicle cell migrations are observed when antisense Mhc95F is expressed in follicle cells during stages 9 to 10, suggesting that the Drosophila myosin VI is required for follicle cell epithelial morphogenesis.

Animals↗
PubMed1999

[Quality control of plasma(serum) specimen for the detection of HCV RNA with PCR].

OBJECTIVE: To define the optimal collection and storage parameters of serum (plasma) for HCV RNA detection. METHODS: The serum(plasma) obtained from HCV RNA positive patients by different means and different processing and storage conditions, then HCV RNA was detected with the fluorescent quantitative PCR. RESULTS: The centrifugation was performed within 2 hours after formation of the clot, loss of HCV RNA titers was 10.42% and significant loss of HCV RNA titers 40.49% was observed after 4 h. The HCV RNA titers in plasma samples with anticoagulants were much higher than that in serum samples(citrate sodium-anticoagulized 40.97%, EDTA-anticoagulated 53.14%). There was no loss of HCV RNA with up to three freeze-thaw cycles. A significant decrease in HCV RNA(15.6%) was observed at -20 degrees C after one year. CONCLUSIONS: The results suggested that it is important to process and store clinical samples for HCV RNA detection. The EDTA-K2 as anticoagulants the plasma must be collected within 3 h, and the serum must be prepared within 2 hours after hemosposia. It is essential to store the sample under -70 degrees C for the stability of HCV RNA in a longer time.

Blood Specimen Collection↗
PubMed1999

[A pharmacognostical study on herba Spirodelae and its adulterants].

OBJECTIVE: To Study the characteristics of Herba Spirodelae(Spirodela polyrrhiza) and its adulterants S. oligorrhiza and Lemna minor for identification. METHOD: The characteristics were compared and identified morphologically and histologically. RESULT: The morphological and histological characteristics of S. polyrrhiza, S. oligorrhiza and L. minor are different from each other. Several tables, keys and drawings are given. CONCLUSION: The main macroscopical and microscopical characteristics can be used fo differentiate S. polyrrhiza from its adultrants.

Drug Contamination↗
PubMed1999

Theoretical and experimental tests of a chromosomal fingerprint for densely ionizing radiation based on F ratios calculated from stable and unstable chromosome aberrations.

In the present study, F ratios for both stable chromosome aberrations, i.e. ratios of translocations to pericentric inversions, and unstable aberrations, i.e. dicentrics and centric rings, were measured using fluorescence in situ hybridization. F ratios for stable aberrations measured after exposure to low (2.89 Gy 60Co gamma rays) and high-LET (0.25 Gy 56Fe ions; 1.25 Gy 56Fe ions; 3.0 Gy 12C ions) radiation were 6.5 +/- 1.5, 4.7 +/- 1.6, 9.3 +/- 2.5 and 10.4 +/- 3.0, respectively. F ratios for unstable aberrations measured after low (2.89 Gy 60Co gamma rays) and high-LET (0.25 Gy 56Fe ions; 3.0 Gy 12C ions) radiations were 6.5 +/- 1.6, 6.3 +/- 2.3 and 11.1 +/- 3.7, respectively. No significant difference between the F ratios for low- and high-LET radiation was found. Further tests on the models for calculation of the F ratio proposed by Brenner and Sachs (Radiat. Res. 140, 134-142, 1994) showed that the F ratio may not be straightforward as a practical fingerprint for densely ionizing radiation.

Cells, Cultured↗
PubMed1998

Agrobacterium VirD2 protein interacts with plant host cyclophilins.

Agrobacterium tumefaciens induces crown gall tumors on plants by transferring a nucleoprotein complex, the T-complex, from the bacterium to the plant cell. The T-complex consists of T-DNA, a single-stranded DNA segment of the tumor-inducing plasmid, VirD2, an endonuclease covalently bound to the 5' end of the T-DNA, and perhaps VirE2, a single-stranded DNA binding protein. The yeast two-hybrid system was used to screen for proteins interacting with VirD2 and VirE2 to identify components in Arabidopsis thaliana that interact with the T-complex. Three VirD2- and two VirE2-interacting proteins were identified. Here we characterize the interactions of VirD2 with two isoforms of Arabidopsis cyclophilins identified by using this analysis. The VirD2 domain interacting with the cyclophilins is distinct from the endonuclease, omega, and the nuclear localization signal domains. The VirD2-cyclophilin interaction is disrupted in vitro by cyclosporin A, which also inhibits Agrobacterium-mediated transformation of Arabidopsis and tobacco. These data strongly suggest that host cyclophilins play a role in T-DNA transfer.

Bacterial Proteins↗
PubMed1998

Limiting dilution analysis of peripheral blood lymphocytes reacting with non-small-cell lung cancer: functionally heterogeneous effectors efficiently lyse autologous cancer cells.

It has recently been shown that the infusion of tumor infiltrating lymphocytes (TIL) and recombinant interleukin-2 (rIL-2) in patients operated on for advanced non-small-cell lung cancer (NSCLC), has significant effects in terms of the survival time and control of local relapses. Despite the evident clinical effects, the treatment is unavailable for patients in which TIL have lost their proliferative potential. In an attempt to identify new sources of effector cells using mixed lymphocyte/tumor cultures (MLTC), populations of peripheral blood (PB) lymphoid cells, which have the capability of lysing autologous NSCLC, were studied at the clonal level. Specific cytolytic lymphocytes were detected at very low frequencies in two out of four patients, whereas non-MHC restricted cytolytic T cells were frequently detected. Cytolytic CD4+ belonged to the Th0 or Th2 subsets and were characterized by cytokine secretion patterns suggestive of a lymphokine cascade that could be involved in cancer control. The identification of different efficient effector mechanisms at the clonal level strongly supports the use of in vitro activated lymphocytes, derived from PB, in protocols of adoptive immunotherapy in patients with advanced NSCLC in which TIL are unavailable.

Aged↗
PubMed1998

Effect of selective substitution of 5-bromocytosine on conformation of DNA triple helices.

Three triplex DNAs containing 5-bromocytosine[BrC] were studied by vibrational spectroscopy and molecular modelling. Firstly, three oligodeoxypyrimidines of 5'-(TC)3-T4-(BrCT)3 [CBrC], 5'-(TBrC)3-T4-(CT)3 [BrCC] and 5'-(TBrC)3-T4-(BrCT)3 [BrCBrC] were synthesized and then reacted with an oligodeoxypurine of 5'-(AG)3 at pH=4.5 in phosphate buffer respectively to form three comparative hairpin triplex named CY,YC and YY. The results of FT-Raman and IR revealed that YY is almost in A-like form, CY and YC are combinations of A-like form and B-like form, but A-form dominates in CY while B-form is equivalent as A-form in YC. The result is consistent with the theoretical analysis.

Cytosine↗
PubMed1998

[Multicentre, randomized, prospective and comparative study of ceftriaxone, cefotaxime and cefuroxime in treating mild to moderate respiratory tract infection].

OBJECTIVE: The objective of this multicentre, randomized, prospective and comparative study was to evaluate and compare the efficacy and safety of 1 g intravenous ceftriaxone (active ingredient of Rocephin), 3 g intravenous cefoiaxime (active ingredient of clafron), and 2.25 g intavenous cefuroxime (active ingredient of Zinacef). METHOD: In this multicentre, randomized, prospective and comparative study, patients received 1 g of ceftriaxone intravenously once a day (group A), or 1 g of cefotaxime intravenously three times a day (group B), or 0.75 g of cefuroxime intravenously three time a day (group C). 197 patients were enrolled in the study, and in 142 (48 in group A, 46 in group B and 48 in group C) we were able to make an evaluation. RESULT: The overall efficacy (bacteriological eradication plus clinical cure or clear improvement) of ceftriaxone, cefotaxime and cefuroxime were 81%, 83%, 79% respectively (P > 0.05). The eradication rate for three groups were 80%, 78%, 75% (P > 0.05). No adverse events occured. CONCLUSION: Data obtained in our study indicate that for the majority of patients with lower respiratory tract infections, 1 g ceftriaxone, 3 g cefotaxime and 2.25 g cefuroxime are effective and safe, and 7 days therapy is enough, but the use of 1 g ceftriaxone is more convenient.

Adolescent↗
PubMed1998

[Clinical analysis of syndrome of obstructive sleep apnea (OSA) induced acute respiratory failure].

OBJECTIVE: To study the clinical characteristics of syndrome of OSA induced acute respiratory failure that might allow earlier recognition and treatment in critical care. METHOD: The clinical and laboratory characteristics of 9 patients were reviewed. RESULT: 9 patients (8 female, 1 male) presented with obesity and mental disturbance, with a BMI being 44.97 kg/m2, (45.25 kg/m2 in the female). The mean age of the group was 67.89 years (61-74 y). All had respiratory acidosis (mean pH 7.1732), hypercapnia (mean PaCO2 12.56 kPa) (8.53-19.09 kPa), and hypoxemia (mean PaO2 5.20 kPa) (3.87-5.87 kPa). During period of clinical stability all but 2 had awake hypercapnia (mean PaCO2 6.23 kPa) (5.10-7.29 kPa). Four of the 9 patients had pulmonary function test showing FEV1% > 70%. CONCLUSION: OSAS induced acute respiratroy failure has a sudden onset and various presentation and can be reversed with early and proper treatment. The severity of abnormal pulmonary function was less than what would be expected to cause respiratroy failure.

Acidosis, Respiratory↗
PubMed1998

[Comparison of continuous positive airway pressure (CPAP) with uvulopalatopharyngoplasty in the treatment of obstructive sleep apnea syndrome].

OBJECTIVE: To compare the efficacy, side effects, and effects on parameters of sleep of continuous positive airway pressure (CPAP) and uvulopalatopharyngoplasty (UPPP) therapy in OSAS and evaluate their role in the treatment of OSAS. METHOD: 60 patients with OSAS were studied, 36 patients treated with CPAP, 24 patients with UPPP, and the parameters of polysomnography (PSG) obtained before and after treatment were analysed. RESULT: Respiratory disturbance index and sleep hypoxemia were improved significantly in both groups, but the CPAP group was better than UPPP group (P < 0.01). The efficacy was 97% in CPAP and 46% in UPPP group (P < 0.01). The longest apnea duration shortened in CPAP group (from 89 +/- 46 to 39 +/- 19) but there was no difference in UPPP (from 76 +/- 26 to 62 +/- 30) group. The apnea duration in 10 patients was lengthened. CONCLUSION: The effects of UPPP in OSAS were limited. CPAP was more effective than UPPP. CPAP may be indicated as the first choice in the treatment of OSAS.

Adult↗
PubMed1998

[Corneal topography analysis after excimer laser photorefractive keratectomy].

OBJECTIVE: To study the pattern of ablation, evaluate centration and stability following excimer laser photorefractive keratectomy (PRK) for myopia. METHOD: Corneal topography of 312 patients (366 eyes) with a month, 3 months and 6 months of follow-up after PRK was examined. RESULTS: The mean decentration from the pupillary center to ablating center was 0.266 mm. In both eyes, the mean decentration was located supernasally. At one month postoperative examination, uniform ablation was 49.5%, semicircular, keyhole, kidney and dumbbell shaped ablations were 42.9% and central island one was 6.0%. Central island pattern affected the best corrected visual acuity greatly. High myopia began regression at 1-3 months after PRK. CONCLUSION: Corneal topography is essential for evaluating surface changes after PRK. Long-time stability issues are answered with continued topographic follow-up.

Corneal Topography↗
PubMed1998

[Experimental studies on dynamic changes of circulating antigens of Schistosoma japonicum in infected rabbits].

AIM: To observe the dynamic changes and disappearance of three kinds of schistosome circulating antigens(CAgs) in infected rabbits before and after praziquantel treatment. METHODS: Dot-ELISA assays were developed by using 3 McAbs to determine the dynamic changes of the gut-associated antigen (GAA), membrane-associated antigen (MAA) and soluble egg antigen (SEA) respectively in sera of rabbits infected with S. japonicum. RESULTS: By the 4th week after infection 39% of the rabbits infected with S. japonicum were GAA positive and only 8.6% were MAA or SEA positive. All the infected rabbits becOme positive with GAA, MAA and SEA by the 8th week after infection. The titers of the GAA, MAA and SEA in sera of the infected rabbits reached their peaks by the 10th week after infection. Titers from rabbits of the untreated group rabbits remained high level until the 27th week after infection. SEA titers were found negative in 10% of the infected rabbits in the treatment group by the 6th week after treatment. The titers of GAA of, MAA' and SEA were found negative in 20%, 80% and 70% of the rabbits in the treatment group, respectively the 8th after treatment. GAA, MAA and SEA in sera except one of the treated rabbits were all negative by the 14th week after treatment. CONCLUSION: The determination of GAA is useful for the early diagnosis of schistosomiasis, while the determination of, MAA and SEA might be used for the efficacy evaluation.

Animals↗
PubMed1998

Biological dosimetry of beta-ray exposure from tritium using chromosome translocations in human lymphocytes analyzed by fluorescence in situ hybridization.

Radiation exposures from tritium make up a substantial fraction of the occupational and accidental radiation exposures associated with the nuclear power industry. Tritiated water, the most abundant form of tritium, is of particular interest because it is readily taken up by human cells and its irradiation of the cells is spread over a period of days. To approximate the prolonged exposure and the conditions that the cells of an individual would experience in vivo, we irradiated human lymphocytes with tritiated water for 48 h in a 1:1 blood:medium mix. For estimation of the tritium beta-ray dose, a cellular water content of 0.78, based on measurements of human lymphoblastoid cells in culture medium, was used. A modified dose calculation formula was developed for the radiation exposure conditions. A total of 48,014 metaphases (14,482 in irradiated samples and 33,532 in control, unirradiated samples) in human lymphocytes cultured for 72 h after exposure were analyzed for chromosome translocations using fluorescence in situ hybridization. The linear slope (alpha coefficient) of the dose-response curve was measured to be (3.93+/-0.42) x 10(-2) and (5.26+/-0.48) x 10(-2) translocations per cell per gray for complete translocations (tc) and complete translocations plus incomplete translocations [ti(Ab)], respectively, when the data were fitted to a linear model using a weighted least-squares method. The alpha coefficient for tc is significantly lower than that for conventionally measured dicentrics after tritium beta irradiation, but the alpha coefficient for tc + ti(Ab) does not differ significantly from that for dicentrics. This is in agreement with theoretical considerations. The importance of scoring criteria is stressed. The frequency of tc + ti(Ab) is proposed to be a reliable biodosimeter for tritium exposures, and its practical use in a dose reconstruction is presented.

Beta Particles↗
PubMed1997

Spectrosomes and fusomes anchor mitotic spindles during asymmetric germ cell divisions and facilitate the formation of a polarized microtubule array for oocyte specification in Drosophila.

In the Drosophila ovary, membrane skeletal proteins such as the adducin-like Hts protein(s), spectrin, and ankyrin are found in the spectrosome, an organelle in germline stem cells (GSC) and their differentiated daughter cells (cystoblasts). These proteins are also components of the fusome, a cytoplasmic structure that spans the cystoblast's progeny that develop to form a germline cyst consisting of 15 nurse cells and an oocyte. Spectrosomes and fusomes are associated with one pole of spindles during mitosis and are implicated in cyst formation and oocyte differentiation. Here we show that the asymmetric behavior of the spectrosome persists throughout the cell cycle of GSC. Eliminating the spectrosome by the htsl mutation leads to randomized spindle orientation, suggesting that the spectrosome anchors the spindle to ensure the asymmetry of GSC division; eliminating the fusome in developing cysts results in defective spindles and randomized spindle orientation as well as asynchronous and reduced cystocyte divisions. These observations suggest that fusomes are required for the proper formation and asymmetric orientation of mitotic spindles. Moreover, they reinforce the notion that fusomes are required for the four synchronous divisions of the cystoblast leading to cyst formation. In htsl cysts which lack fusomes and fail to incorporate a hts gene product(s) into ring canals following cyst formation, polarized microtubule networks do not form, the dynamics of cytoplasmic dynein is disrupted, and oskar and orb RNAs fail to be transported to the future oocyte. These observations support the proposed role of fusomes and ring canals in organizing a polarized microtubule-based transport system for RNA localization that leads to oocyte differentiation.

Animals↗
PubMed1997

Biphasic transitions of a hairpin hexanucleotide triplex DNA.

The conformational transitions (helix-coil transitions) of three hairpin triple helices, models 5'-(A-G)(3) + 5'-(T-C)(3)-T(4)-((br)C-T)(3) [CY], 5'-(A-G)(3) + 5'-(T-(br)C)(3)-T(4)-(C-T)(3) [YC] and 5'-(A-G)(3) + 5'-(T-(br)C)(3)-T(4)-((br)C-T)(3) [YY], are characterized in this work by UV spectroscopy. Melting of these triplexes is biphasic, and the profiles are used to obtain the thermodynamic parameters. The thermodynamic properties of the hairpin triplex are T(m) = 19.45 degrees C and DeltaH(vH) = 293.12 kJ mol(-1) for CY, T(m) = 22.85 degrees C and DeltaH(vH) = 256.63 kJ mol(-1) for YC and T(m) = 28.47 degrees C and DeltaH(vH) = 234.68 kJ mol(-1) for YY at pH 4.4. Those of the duplex are T(m) = 30.50 degrees C and DeltaH(vH) = 427.09 kJ mol(-1) for CY, T(m) = 32.96 degrees C and DeltaH(vH) = 374.47 kJ mol(-1) for YC and T(m) = 33.24 degrees C and DeltaH(vH) = 329.67 kJ mol(-1) for YY at pH 4.4. The distinct transitions of triplex to duplex and duplex to single strands are analyzed using the nearest-neighbor Ising model. Electrostatic effects on each conformation are also analyzed.

Journal Article↗
PubMed1997

Radioactivity in zircon and building tiles.

Zircon (ZrSiO4) is commonly used in the manufacture of glazed tiles. In this study we found high concentrations of the radionuclides 226Ra, 232Th, 40K in zircon sand. The average radium equivalent (A(Ra) + 1.26 A(Th) + 0.086 A(k)) in zircon sand is 17,500 Bq kg(-1), which is 106 times as much as that in ordinary building materials. The external radiation (gamma + beta) dose rates in air at 5 cm from the surface of piles of zircon sand sacks range from 1.1 to 4.9 x 10(-2) mGy h(-1) with an average of 2.1 x 10(-2) mGy h(-1). Although no elevated gamma-ray radiation or radon exhalation rate was detected in rooms decorated with glazed tiles, which is characteristic of combined alpha, beta and gamma emitting thin materials, the average gamma-ray radiation dose rate at the surface of the tile stacks in shops is 1.5 times as much as the indoor background level. The average area density of total beta emitting radionuclides in glazed floor tiles and glazed wall tiles is 0.30 Bq cm(-2) and 0.28 Bq cm(-2), respectively. It was estimated that the average beta dose rates in tissue at a depth 7 mg cm(-2) with a distance 20-100 cm from the floor tiles were 3.2 to 0.9 x 10(-7) Gy h(-1). The study indicates that the beta-rays from glazed tiles might be one of the main factors leading to an increase in ionizing radiation received by the general public. Workers in glazed tile manufacturing factories and in tile shops or stores may be exposed to elevated levels of both beta-rays and gamma-rays from zircon sand or glazed tile stacks. No elevated radiation from unglazed tiles was detected.

Gamma Rays↗