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Biomedical subjects

Q Du

Publications and source records attributed to Q Du.

At least 19 recordsLinked to original sources
PubMed2006

Regulation of PUMA-alpha by p53 in cisplatin-induced renal cell apoptosis.

Nephrotoxicity is a major side effect of cisplatin, a widely used cancer therapy drug. Depending on its concentration, cisplatin induces necrosis or apoptosis of tubular cells in the kidneys, whereas the underlying injury mechanism is unclear. Our recent work has suggested a critical role for p53 in cisplatin-induced tubular cell apoptosis; nevertheless, the apoptotic events triggered by p53 remain elusive. The current study has examined Bcl-2 family proteins, critical regulators of apoptosis that may be subjected to p53 regulation. Following cisplatin treatment, the expression of Bcl-xL, an antiapoptotic molecule, was suppressed, while the expression of Bak, a proapoptotic molecule, increased slightly. Of interest, PUMA-alpha, a newly identified p53-responsive proapoptotic Bcl-2 family protein, was drastically induced by cisplatin. PUMA-alpha induction preceded or paralleled the development of apoptosis. Induced PUMA-alpha was localized in mitochondria and appeared to antagonize Bcl-xL via molecular interaction. PUMA-alpha induction during cisplatin treatment was attenuated by pifithrin-alpha, a pharmacological inhibitor of p53, which was accompanied by the amelioration of Bax activation, cytochrome c release and apoptosis. Moreover, PUMA-alpha induction was suppressed by dominant-negative p53. Importantly, cisplatin-induced apoptosis was ameliorated in PUMA-alpha knockout cells. In vivo, cisplatin induced PUMA-alpha in the kidneys, and the inductive response was abrogated in p53-deficient animals. Together, this study has demonstrated the first compelling evidence for the involvement of PUMA-alpha in p53-mediated renal cell apoptosis during cisplatin nephrotoxicity.

Animals↗
PubMed2006

Di-2-ethylhexyl phthalate in the fruits of Benincasa hispida.

Di-2-ethylhexyl phthalate (DEHP) is a commonly used plasticizer that is harmful to human health. magnetic resonance spectroscopy from the edible fruit flesh of Benincasa hispida (wax gourd) of the plant family Curcurbitaceae. The DEHP content of seven wax gourd samples collected from southern and northern provinces in China was determined as (mean +/- SD): 18.3 +/- 0.43, 2.64 +/- 0.44, 44.0 +/- 0.34, 62.5 +/- 0.48, 52.0 +/- 0.42, 58.3 +/- 0.55 and 75.5 +/- 0.63 mg kg-1 fresh weight, respectively, indicating that most wax gourds were severely contaminated with DEHP.

China↗
PubMed2006

Detection of betanodavirus in juvenile barramundi, Lates calcarifer (Bloch), by antigen capture ELISA.

Betanodavirus infection of fish has been responsible for mass mortalities in aquaculture hatcheries worldwide. Betanodaviruses possess a bipartite single-stranded RNA genome consisting of the 3.1 kb RNA1 encoding an RNA-dependent RNA polymerase and the B2 protein, while the 1.4 kb RNA2 encodes the viral nucleocapsid protein, alpha. A panel of six monoclonal antibodies against the alpha protein of greasy grouper nervous necrosis virus (GGNNV) was developed for use in diagnostics. All antibodies reacted with native and recombinant alpha in immunoblot and indirect immunofluorescence assays. Each of the monoclonal antibodies reacted against discrete regions of the alpha protein, though none reacted with the extreme C-terminal region of the protein. One of the monoclonal antibodies, specific for the K151-T246 region of alpha, was used for the development of an antigen capture ELISA. In this assay we could detect 10(3)-10(4) TCID(50) units of virus derived from infected tissue culture supernatants. Head tissue extracts prepared from experimentally infected barramundi, Lates calcarifer, juveniles were assayed for GGNNV using the antigen capture assay and a clear increase in alpha antigen was detected from 5 to 15 days post-challenge. The assay thus represents a useful method for field-based detection of betanodavirus in fish hatcheries.

Amino Acid Sequence↗
PubMed2001

Vertical transmission of Kaposi's sarcoma-associated herpesvirus.

Little is presently known about the specific routes of transmission of Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus-8 (HHV-8). To investigate whether this agent might be transmitted vertically from mother to infant, we conducted a study on 89 KSHV seropositive mothers and their newborn infants. Thirteen mothers (14.6%) had KSHV DNA detected in their peripheral blood mononuclear cells (PBMC). Two of 89 samples drawn at birth from infants born to KSHV seropositive mothers had KSHV DNA detectable within their PBMC. These findings suggest that KSHV can be transmitted perinatally, but infrequently. Other routes of transmission such as horizontal transmission remain the most likely means of KSHV transmission.

Adolescent↗
PubMed2001

Preparative separation of isoflavone components in soybeans using high-speed counter-current chromatography.

Four isoflavone components were purified from soybean extract by high-speed counter-current chromatography (HSCCC). Two types of multilayer coil separation columns were used: a small column made of standard 2.6-mm I.D. PTFE (polytetrafluoroethylene) tubing with a 260-ml capacity and a large column of convoluted PTFE tubing of 5.7-mm average I.D. with a 1,200-ml capacity. Separation was performed with a two-phase solvent system composed of hexane-ethyl acetate-1-butanol-methanol-acetic acid-water (1:2:1:1:5:1, v/v) by eluting the lower aqueous phase at 2 ml/min (small column) and 5 ml/min (large column) at a revolution speed of 700 rpm. From 500 mg of crude sample the small column yielded 33 mg of daidzin, 41 mg of genistin, 27 mg of 6''-O-malonyldaidzin and 24 mg of 6"-O-malonylgenistin. The large convoluted column separated, from 3 g of crude sample, 203 mg of daidzin, 241 mg of genistin, 158 mg of 6''-Omalonyldaidzin and 135 mg of 6"-O-malonylgenistin all at over 90% purity. The convoluted tubing facilitated preparation of a large multilayer coil due to its high flexibility.

Chromatography↗
PubMed2001

Separation of radioactive metabolites in cultured tea cells fed with [14C]phenylalanine using high-speed counter-current chromatography.

Separation of radioactive metabolites in cultured tea cells fed with [14C]phenylalanine was conducted using high-speed counter-current chromatography. Among seven components obtained our studies focused two metabolites, i.e. (-)-epicatechin and D,L-catechin. The specific radioactivity of (-)-epicatechin was 212.01 KBq/mg, amounting to 8.5% of the total radioactivity of ethyl acetate extract while that of D,L-catechin was 1.0006 MBq/mg or 5.4% of the total.

Carbon Radioisotopes↗
PubMed2001

A mammalian Partner of inscuteable binds NuMA and regulates mitotic spindle organization.

Asymmetric cell division requires the orientation of mitotic spindles along the cell-polarity axis. In Drosophila neuroblasts, this involves the interaction of the proteins Inscuteable (Insc) and Partner of inscuteable (Pins). We report here that a human Pins-related protein, called LGN, is instead essential for the assembly and organization of the mitotic spindle. LGN is cytoplasmic in interphase cells, but associates with the spindle poles during mitosis. Ectopic expression of LGN disrupts spindle-pole organization and chromosome segregation. Silencing of LGN expression by RNA interference also disrupts spindle-pole organization and prevents normal chromosome segregation. We found that LGN binds the nuclear mitotic apparatus protein NuMA, which tethers spindles at the poles, and that this interaction is required for the LGN phenotype. Anti-LGN antibodies and the LGN-binding domain of NuMA both trigger microtubule aster formation in mitotic Xenopus egg extracts, and the NuMA-binding domain of LGN blocks aster assembly in egg extracts treated with taxol. Thus, we have identified a mammalian Pins homologue as a key regulator of spindle organization during mitosis.

Animals↗
PubMed2001

Synthesis of selenium-derivatized nucleosides and oligonucleotides for X-ray crystallography.

We report here the synthesis of nucleoside and oligonucleotide analogs containing selenium, which serves as an anomalous scattering center to enable MAD phase determination in nucleotide X-ray crystallography. We have developed a phase transfer approach to introduce the selenium functionality in A, C, G, T, and U nucleosides at 5'-positions. In the incorporation of the selenium functionality, the leaving groups (bromide, mesyl, and tosyl) were readily displaced by sodium selenide, sodium diselenide, and sodium methyl selenide with yields higher than 90%. Selenium-derivatized oligonucleotides have been synthesized via phosphoramidite chemistry.

Crystallography, X-Ray↗
PubMed2001

Expression of two HOOKLESS genes in peas (Pisum sativum L.).

The apical hook of dark-grown dicotyledonous plants results from asymmetric growth of its inner and outer sides. It is a protective structure that prevents damage to the shoot apical meristem and the young leaves as the seedling pushes through the soil. Two phytohormones, ethylene and auxin, are thought to be involved in regulating apical hook formation. HOOKLESS1 (HLS1) of Arabidopsis was recognized as an ethylene-response gene whose product is required for hook formation. We cloned two cDNAs from peas, Ps-HLS1 and Ps-HLS2, whose products are functional homologs of HLS1. Both Ps-HLS1 and Ps-HLS2 complement the hls1 mutation in Arabidopsis. Expression of Ps-HLS1 is enhanced by ethylene and by IAA. Because the effect of ethylene is counteracted by 2,5-norbornadiene, an inhibitor of ethylene action, it appears that the primary factor in apical hook formation in peas is ethylene.

Base Sequence↗
PubMed2001

[Genotype polymorphism and its implications of mannose-binding protein allele in 5 Chinese nationalities].

OBJECTIVE: To detect the genotypes and sequences of the exon 1 of human mannose-binding protein (MBP) allele in 5 Chinese nationalities. METHODS: The genotypes of MBP gene of 5 Chinese nationalities were detected by polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP). The exon 1 of the MBP gene of 22 Chinese Hans was analyzed by using ABI 310 genetic analyzer. RESULTS: The DNA sequences of exon 1 of Chinese MBP gene were acquired. The allele frequencies of the codon 54 of the MBP gene (MBP-54) of 5 Chinese nationalities were 0.181(Hans), 0.128(Uygurs), 0.181(Mongols), 0.179(Tibetans) and 0.181(Yis). The allele distribution for MBP-54 mutation of 5 Chinese nationalities was in good agreement with Hardy-Weinberg equilibrium. Compared with the Hans, Uygurs had a lower MBP-54 mutation rate. There were no differences in the allele frequencies between the chronic hepatitis B patients and health controls in Chinese Hans. The mutations of the codons 52 and 57 were not detected in this study. CONCLUSION: A higher prevalence of MBP-54 mutation was found in 5 Chinese nationalities, MBP-54 mutation was not associated with the persistence of hepatitis B.

Adolescent↗
PubMed2001

[Genotyping of HIV resistant alleles in indigenous Tibetan ethnic group of China: low frequency of CCR5triangle32 and high frequency of CCR2b-64I alleles].

OBJECTIVE: To investigate the allelic polymorphism of CCR5triangle32, CCR5m303, CCR2b-64I and SDF1-3'A in Tibetan population in Lasa area of China. METHODS: The genomic DNA samples from 330 Tibetan subjects' whole blood samples were purified by use of QIAgen Blood Kit and identified by PCR or PCR-RFLP analyses. RESULTS: The mutation frequencies of CCR5triangle32 and CCR5m303 alleles were lower than 0.15%, and those of CCR2 b-64I and SDF1-3'A alleles were 29.42% and 19.24% respectively in the study samples. The allelic polymorphisms of the four alleles of Tibetan population were similar to those of Chinese Han population. Genotype distribution of the four alleles was in accordance with Hardy-Weinberg equilibrium. The above results suggest that Tibetan population may be relatively susceptive to HIV-1. CONCLUSION: The Chinese Tibetan may have a lower frequency of CCR5triangle32 and a higher frequency of CCR2b-64I allele, compared with Caucasian.

Adolescent↗
PubMed2001

[Hypermethylation of the calcitonin gene as molecular genetic marker in detecting minimal residual disease of leukemia].

OBJECTIVE: To explore whether detecting minimal residual disease (MRD) of leukemia with hypermethylation of the calcitonin gene as molecular genetic marker of leukemic clone may predict the prognosis. METHODS: Polymerase chain reaction (PCR) in combination with digestion of DNA with HpaII was used to examine the methylation patterns of the calcitonin gene in 29 cases with acute leukemia and 8 cases with transformation of chronic myeloid leukemia. By using PCR, MRD was longitudinally detected in patients who were positive for hypermethylation of the calcitonin gene as molecular genetic marker. RESULTS: Twenty patients with acute leukemia and transformation of chronic myeloid leukemia had MRD after complete remission. Bone marrow relapse occurred soon when MRD persisted or reappeared. It may predict bone marrow relapse two to eleven months earlier. The patients who were negative for MRD early and remained persistently negative may acquire prolonged survival. CONCLUSION: MRD of leukemia may be monitored by using PCR with hypermethylation of the calcitonin gene as molecular genetic marker for leukemic clone. It may prove useful in predicting the prognosis of leukemia.

Adult↗
PubMed2001

[The clinical and pathological research of supraglottic carcinoma with bilateral cervical nodal metastasis].

OBJECTIVE: To evaluate clinical and pathological characteristics in patients with supraglottic carcinoma and bilateral cervical nodal metastasis. METHOD: 60 patients with supraglottic carcinoma treated in this hospital from 1985 to 1994 were retrospectively reviewed, including 30 cases with bilateral metastasis (experiment group) and 30 cases with unilateral metastasis (control group). The two groups were contrasted according to site of tumor, tumor diameter, surface morphology, clinical staging, the degree of invading the contralateral semilarynx, Border's grading, growth mode of tumor edge, the degree of invading preepiglottic space. RESULT: In stage T4 cases with low grading of cell differentiation made up 63.6% (7/11) in the bilateral metastasis group, while 10% in the ipsilateral metastasis group (P < 0.05). Significant differences lied between N0 group and N2 group (P < 0.05). Moderate and severe invasion of contralateral semilarynx in the bilateral group made up 87.5% (14/16), significantly higher than that in ipsilateral group 53.3% (16/30). CONCLUSION: Bilateral neck dissection should be used in T4 cases with low grading of cell differentiation in which the contralateral semilarynx was invaded. Bilateral neck dissection should be taken for the treatment of supraglottic carcinoma with N2.3 diseases. Bilateral neck dissection is recommended for the patients with moderate and severe invasion of the contralateral semilarynx.

Adult↗
PubMed2001

[Permeation of buspirone hydrochloride across animal buccal mucosa and its mechanism].

AIM: To study the permeation of busprione hydrochloride across animal buccal mucosa and its permeation mechanism. METHODS: The in vitro penetration model was designed to investigate drug buccal mucosa permeability, and the influence factors (different animal oral mucosa, such as rabbit, guinea pig, pig, sheep and cow, drug concentrations and solution pH values) were measured. RESULTS: The permeability of rabbit buccal mucosa for busprione hydrochloride was the largest. The permeation rate was increased with solution pH and directly to the drug concentration. CONCLUSION: The transport way of busprione hydrochloride was passive diffusion and the transport channel was through cells.

Animals↗
PubMed2001

[Study on hypermethylation of the calcitonin gene in malignant hematological disorders].

OBJECTIVE: To investigate the clinical significance of hypermethylation of the calcitonin (CT) gene in malignant hematological disorders (MHD). METHODS: Polymerase chain reaction (PCR) in combination with digestion of DNA with Hpa II was used to examine the methylation patterns of the CT gene in 73 patients with MHD, 6 healthy people and 24 patients with nonmalignant hematological disorders (NON-MHD). RESULTS: Hypermethylation of the CT gene occurred in 12 of 14 (85.7%) patients with acute lymphoblastic leukemia (ALL), 9 of 15 (60%) acute nonlymphocytic leukemia (ANLL), 8 of 10 (80%) chronic myelogenous leukemia (CML), 5 of 15 (33.3%) malignant lymphoma (ML), 2 of 5 patients with myelodysplastic syndrome (MDS), 1 of 2 malignant histiocytosis (MH), 1 of 3 chronic lymphocytic leukemia (CLL) and 1 of 9 multiple myeloma (MM). However, it did not occur in normal controls and NON-MHD. CONCLUSION: Hypermethylation of CT gene may serve as an important molecular maker for tumorous cell clone and may be useful in diagnosing MHD, monitoring minimal residual disease and predicting prognosis.

Calcitonin↗
PubMed2001

[Clinical application and evaluation of polymerase chain reaction-microwell plate hybridization assay in the detection of Mycobacterium tuberculosis].

OBJECTIVE: To evaluate the clinical application and feasibility of polymerase chain reaction-microwell plate hybridization assay in the detection of Mycobacterium tuberculosis. METHODS: 1130 specimens with strong suspicion for mycobacterium tuberculosis were collected from the hospitals and were detected by fast bacilli stain, culture, PCR-electrophoresis and PCR-microwell plate hybridization respectively. The laboratory results were analyzed in combination with the symptoms and signs of patients and the observations on treatment. Also detected were 100 samples from the clinically evidenced non-tuberculosis patients. RESULTS: In the 100 samples collected from the patients without tuberculosis, the PCR-hybridization method and culture method did not detect Mycobacterium tuberculosis, but the fast bacilli stain method and PCR-electrophoresis method brought out one and two false-positive results respectively. The results of testing the 1030 clinical samples which probably contained Mycobacterium tuberculosis demonstrated that the PCR-hybridization method had the highest positive rate (481/1030) among the four methods, and the positive rates of the other three methods were PCR-electrophoresis (406/1030), culture (365/1030) and fast bacilli stain (256/1030) in proper order. The chi-square test showed that there were significant difference between the PCR-hybridization method and the other three methods respectively (P < 0.0083 or P < 0.0017). CONCLUSION: PCR-Hybridization method is specific, sensitive, accurate and fast in detecting mycobacterium tuberculosis; it is worthy to be used clinically.

Evaluation Studies as Topic↗
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↗