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Biomedical subjects

Qing Zhang

Publications and source records attributed to Qing Zhang.

At least 127 records · Page 7Linked to original sources
PubMed2005

[Survey of the utilization and adverse effects of antibacterial drugs in patients admitted for respiratory diseases].

OBJECTIVE: To evaluate the utilization of antibacterial drugs and their adverse effects in patients admitted for respiratory disease based on medical record review. METHODS: The medical records of 141 inpatients admitted in 2002 for respiratory diseases were reviewed. The drug utilization index (DUI) and daily cost of antibacterial drugs were calculated, with also assessment of the adverse effects in relation to the drug use. RESULTS: The DUI ranged from 0.9 to 1.1 in 66.7% of the patients, and the daily cost of the antibacterial drugs was 317.8+/-194.3 RMB, with a total of 14 cases with adverse drug effects recorded. CONCLUSIONS: The utilization of antibacterial drugs was basically adequate in Nanfang Hospital though with occasional abuse of cefoperazone and sulbactam, inappropriate combination and high cost of the antibacterial drugs. More careful application of these drugs in old patients is stressed.

Adolescent↗
PubMed2005

[Theory of local inflammatory infiltration and irritation in the pathogenesis of acquired cholesteatoma].

OBJECTIVE: To explore the deep pathogenesis of acquired cholesteatoma. METHODS: The temporal bone slides of 12 ears with retraction pocket were histopathologically studied under microscope, especially focusing on the location of retraction pocket and inflammatory pathology in the local middle ear cavity next to retraction pockets. The temporal bone slides of 11 ears with acquired cholesteatoma were histopathologically observed and 33 cases diagnosed as acquired cholesteatoma were clinically observed observed in the local middle ear cavity next to the part without retraction pocket of eardrum. The results of pathological observation of the temporal bone slides with acquired cholesteatoma and clinical observation during operation for acquired cholesteatoma show that cholesteatoma invade mainly and occupied the ossicular chain eara of the middle ear cleft. CONCLUSION: In the pathological process of otitis media, the intractable pathological changes in the ossicular chain area can inward adhere posterosuperior quadrant or pars flaccida of the eardrum to form retraction pocket and permanently infiltrate the external squamous epithelial layer of retraction pocket to excessively proliferate and keratinize, leading to formation of acquired cholesteatoma.

Adolescent↗
PubMed2005

[Measurement of terrestrial ecosystem service value in China].

With the measurement of net primary productivity and vegetation coverage fraction based on remote sensing data,the terrestrial ecosystem service value of China in 2000 was quantitatively estimated as 9.17 x 10(12) yuan (RMB). The spatial distribution of the ecological service value showed a decreasing trend from southeast China to northwest China, which was consistent with the regional distribution of vegetation types. The service value varied with different vegetations, e. g., forests had the highest service value of 18 789 yuan x hm(-2), accounting for 40.80% of the total terrestrial ecosystem service value, and bushes and farmlands had a higher service value of 13 789 yuan x hm(-2) and 13054 yuan x hm(-2), which was 10.79% and 24.23% of total value, respectively. The service value was also varied with different ecosystem functions, i.e., gas regulation contributed the highest value of 45.16% to the total service value, and the contribution of soil conservation and water conservation was 28.83% and 14.44%, respectively. The integrated approach coupling ecology and remote sensing data provided a new method to measure the ecological service value, which could estimate the value objectively and spatial-explicitly. However, some uncertainties still existed in this approach, which should be improved in the future studies.

China↗
PubMed2005

[Comparison of the suppressive effects of tramadol and low-dose ketamine on the patients with postoperative hyperalgesia after remifentanil-based anaesthesia].

OBJECTIVE: To compare the suppressive effects of tramadol and low-dose ketamine on postoperative hyperalgesia after remifentanil-based anaesthesia. METHODS: A total number of sixty ASA I - II adult patients who undergone the operation of cranio-cervical region were assigned to three groups randomly, controlled group (Group C), tramadol group (Group T) and low-dose ketamine group (Group K). Before the end of surgery, Group T was given tramadol 0.3 mg/kg, Group K was given ketamine 0.5 mg/kg and Group C wasn't given any medicine. When the visual analogue scale (VAS) score of the group C was over five, tramadol 0.3 mg/kg was given to the patients. The four-level verbal rating scale after trachea extubation, VAS score, the time of requiring analgesia again by patients and adverse drug reactions such as nausea, vomit, diplopia and hallucination were recorded for 24 hours after surgery. RESULTS: After operation, the VAS score of Group C was much higher than that of Group K in the first 4 hours and Group T was higher than Group K during 2, 3 and 4 hours (P < 0.05). The time of requiring analgesia by patients in Group C and Group T was earlier than Group K. The adverse drug reaction showed no significant difference in three groups. CONCLUSION: Low-dose ketamine had significant suppressive effect on patients with postoperative hyperalgesia and acute opioid tolerance after remifentanil-based anaesthesia.

Adult↗
PubMed2005

[Pilot study of dental erosion and associated factors in university student volunteers].

OBJECTIVE: To investigate dental erosion and associated etiologic factors among students from one university. METHODS: A total of 179 student volunteers from one university were examined clinically for their dental erosion. Each was required to complete a questionnaire regarding potentially associated etiologic factors. A modified criteria was used to grade the severity of dental erosion. RESULTS: The prevalence of dental erosion of this group was 45.8%, mostly in enamel. Facial surfaces of anterior teeth were most vulnerable to erosion. Statistic analysis indicated that acidic diets, such as carbonated drink, fruit juice, fruit drink and banana were risk factors to dental erosion. CONCLUSIONS: The findings strongly suggest that much attention should be given to dental erosion which was probably associated with acidic diet.

Adolescent↗
PubMed2005

[Correlation between octanol-air partition coefficients and retention parameters of polychlorinated biphenyls on gas chromatographic columns].

Octanol-air partition coefficient (Koa) is a key descriptor for describing the partitioning of organic pollutants, especially persistent organic pollutants (POPs), between air and environmental organic phases. Thus it is necessary to determine or predict the Koa values of these compounds. A novel method was introduced to describe the quantitive relationship between the octanol-air partition coefficients and gas chromatographic (GC) retention parameters A, B values of polychlorinated diphenyls (PCBs) which are typical persistent organic pollutants. By the correlation analysis between GC retention parameters A, B values of PCBs on DB-1, DB-5 and DB-1701 columns, and their octanol-air partition coefficients, a good linear relationship was found. The stepwise multiple linear regression was used to derive binary equations with the correlation coefficients greater than 0.99, and the standard deviations are less than 0.11. In addition, based on the 153 experimental A, B values and 56 predicted A, B values, the Koa values of the remaining 190 PCBs were predicted.

Air↗
PubMed2005

[Quantitative relationship between molecular structure of polychlorinated biphenyls (PCBs) and enthalpy change (deltaH), entropy change (deltaS') in chromatographic process].

The relationship between the rule of chromatographic retention value and molecular structure is an important part in the research of chromatographic thermodynamics. The topological index structural parameter JG and the topological index adjoining parameter LJ are put forward. Parameter J(G) describes the correlation of quantity and position of chlorine atoms in polychlorinated biphenyl (PCB) molecules. Parameter L(J) describes the ortho-position correlation of chlorine atoms in PCB molecules. The relational expression between the PCB molecular structures and their enthalpy change (deltaH), entropy change (deltaS') in chromatographic process was discovered. The values of enthalpy change and entropy change for about 140 kinds of polychlorinated biphenyls in chromatographic process on three stationary phases, DB-1, DB-5 and DB-1701, were determined. In comparison with deltaH and deltaS' of the experimental data those calculated from the relational expression had the average relative deviations for deltaH and deltaS' are 0.56% -0.97% and 0.55% - 1.06%, respectively.

Chromatography↗
PubMed2005

[Gene transfection of Livin isoforms into A549 cell line and its effect on cell growth and sensitivity to chemotherapy and radiotherapy].

OBJECTIVE: To express Livin alpha & beta in A549 cells by using gene transfection, and to observe its effect on cell growth and cell sensitivity to chemotherapy drugs and radiation. METHODS: Eukaryotic expression vectors of Livin alpha & beta were transfected into A549 cells and cell clones with stable expression were obtained. Livin alpha & beta expression levels in the transfected A549 cells were assessed at mRNA level and protein level, respectively. Cell growth status was assessed by biological features. MTT was performed to test effects of Livin on sensitivity of the A549 cells to chemotherapy drugs and radiation, and cell cycle analysis was performed to evaluate cell apoptosis. RESULTS: After transfection, positive cells, especially A549 cells expressing Livin, showed an increase of about 20% in colony-forming ability, a shorter doubling time (P < 0.05) and lower sensitivity to chemotherapy drugs and radiation (P < 0.01). Only 0.2% of the cells committed apoptosis with 10 Gy radiation. CONCLUSION: Livin isoforms, especially Livin alpha, are implicated in genesis and development of lung cancer, thus may be an important mechanism for drug resistance of lung cancer cells.

Adaptor Proteins, Signal Transducing↗
PubMed2005

[The effects of different transcripts of AML1 on the transactivation of M-CSF-R gene].

OBJECTIVE: To observe the effects of AML1A and AML1B, two splicing isoforms of AML1, on the transactivation of macrophage colony-stimulating factor receptor (M-CSF-R), and explore the mechanism of hematopoietic stem cell committed differentiation and leukemogenesis. METHODS: The expressive plasmids of AML1A and AML1B were constructed, and co-transfected into CV-1 cells with a luciferase reporter plasmid containing M-CSF-R promoter. The transactivity of M-CSF-R promoter was assayed by luminometer. RESULTS: AML1B exhibited a distinct transactivity to M-CSF-R promoter with a sequence-specificity and dosage-dependent manner. AML1A showed no any transactivity but antagonized the effect of AML1B, causing marked reduction of M-CSF-R expression. CONCLUSION: An intact structure of AML1 is necessary for transactivation of M-CSF-R. AML1A may interfere with the transactivation of AML1B, and play a key role in the fine regulation of committed differentiation of hematopoietic cell.

Animals↗
PubMed2005

[Study on Bartonella species in rodents in western Yunnan, China].

OBJECTIVE: To study the infection status of Bartonella spp. in rodents in western part of Yunnan province. METHODS: Blood samples were collected from four species of rodents captured in four counties in western Yunnan in 2004. Bartomella was isolated through being cultured in brain and heart infusion agar media containing 5% rabbit blood. Suspective Bartomella strains isolates were confirmed by amplification of 379 bp of citrate synthase (gltA) gene with specific primer by polymerase chin reaction (PCR). RESULTS: Fifty-four strains of Bartomella isolates were obtained from 397 samples including four rodent species captured in the fields with an overall isolation-rate of 13.6% (54/397). The rates of isolation among different species were: 22.0% (22/100) in Rattus nitidus, 14.8% (31/210) in Rattus flavipectus and 1.2%(1/87) in Rattus norvegicus while in R. t. yunnanensis it was negative. CONCLUSION: These findings demonstrated that the local rodents in western Yunnan were widely infected by Bartomella spp. It is indispensable to study the vector and the route of transmission to discover the relations between Bartomella and human diseases.

Animals↗
PubMed2004

DNA biosensors based on self-assembled carbon nanotubes.

DNA biosensors based on self-assembled multi-walled carbon nanotubes (MWNTs) were described in this paper, in which the probe DNA oligonucleotides were immobilized by forming covalent amide bonds between carboxyl groups at the nanotubes and amino groups at the ends of the DNA oligonucleotides. Hybridization between the probe and target DNA oligonucleotides was confirmed by the changes in the voltammetric peak of the indicator of methylene blue. Our results demonstrate that the DNA biosensors based on self-assembled MWNTs had a higher hybridization efficiency compared to those based on random MWNTs. In addition, the developed DNA biosensors also had a high selectivity of hybridization detection.

Adsorption↗
PubMed2004

Dicer is required for embryonic angiogenesis during mouse development.

Dicer is a multi-domain protein responsible for the generation of short interfering RNAs (siRNAs) from long double-stranded RNAs during RNA interference. It is also involved in the maturation of microRNAs, some of which are transcriptional regulators of developmental timing in nematodes. To assess the role of Dicer in mammals, we generated Dicerex1/2 mice with a deletion of the amino acid sequences corresponding to the first and second exons of the dicer gene via homologous recombination. We found that Dicerex1/2 homozygous embryos displayed a retarded phenotype and died between days 12.5 and 14.5 of gestation. Thus, these results show that dicerex1/2 is severely hypomorphic and that Dicer is essential for normal mouse development. Interestingly, we also found that blood vessel formation/maintenance in dicerex1/2 embryos and yolk sacs were severely compromised, suggesting a possible role for Dicer in angiogenesis. This finding is consistent with the altered expression of vegf, flt1, kdr, and tie1 in the mutant embryos. Taken together, the results of this study indicate that Dicer exerts its function on mouse embryonic angiogenesis probably through its role in the processing of microRNAs that regulate the expression levels of some critical angiogenic regulators in the cell.

Animals↗
PubMed2004

Absence of a deglutitive inhibition equivalent with secondary peristalsis.

This study aimed to determine the interactions between closely paired swallow-induced primary peristalsis (PP) and air injection-induced secondary peristalsis (SP). Ten subjects (7 men, 18-42 yr) were studied using a catheter, including two sleeves (upper and lower esophageal sphincters), a midesophageal infusion port, and seven esophageal and two pharyngeal recording sites. Ten iterations of PP and SP were induced by 5-ml water swallows and 20-ml intraesophageal air injections, respectively. Thereafter, the interactions between PP and SP, separated by 1- to 12-s intervals, were studied in all four possible sequences: paired swallows, swallow preceded by air injection, air injection preceded by swallow, and paired air injections. Tracings were analyzed for lower esophageal sphincter relaxation, presence and integrity of peristalsis, and event interaction. Eight subjects with success rates of both >/=90% PP and >/=80% SP were analyzed (PP 97 +/- 2%, SP 90 +/- 3%). During paired PP interactions and SP followed by PP, the first sequence was inhibited by the second with intervals < 4-6 s. However, no inhibition of the first peristaltic sequence was found in either PP followed by SP trials or SP followed by air injection. In contrast to swallowing or proximal esophageal distention, air injection into the lumen of the midesophagus does not inhibit an ongoing peristaltic event. Being that the elicitation of SP in the smooth muscle esophagus is intramurally mediated, this suggests that deglutitive inhibition is a centrally mediated phenomenon rather than an intrinsic property of peristalsis.

Adult↗
PubMed2004

SRC family kinases mediate epidermal growth factor receptor ligand cleavage, proliferation, and invasion of head and neck cancer cells.

Head and neck squamous cell carcinomas (HNSCCs) are characterized by up-regulation of the epidermal growth factor receptor (EGFR). We previously reported that a gastrin-releasing peptide/gastrin-releasing peptide receptor (GRP/GRPR) autocrine growth pathway is activated early in HNSCC carcinogenesis. GRP can induce rapid phosphorylation of EGFR and p42/44 mitogen-activated protein kinase (MAPK) activation in part via extracellular release of transforming growth factor alpha (TGF-alpha) by matrix metalloproteinases (MMPs). It has been reported that Src family kinases are activated by G-protein-coupled receptors (GPCRs), followed by downstream EGFR and MAPK activation. To further elucidate the mechanism of activation of EGFR by GRP in HNSCC, we investigated the role of Src family kinases. Blockade of Src family kinases using an Src-specific tyrosine kinase inhibitor A-419259 decreased GRP-induced EGFR phosphorylation and MAPK activation. GRP also failed to induce MAPK activation in dominant-negative c-Src-transfected HNSCC cells. Invasion and growth assays showed that c-Src was required for GRP-induced proliferation or invasion of HNSCC cells. In addition to TGF-alpha release, GRP induced amphiregulin, but not EGF, secretion into HNSCC cell culture medium, an effect that was blocked by the MMP inhibitor marimastat. TGF-alpha and amphiregulin secretion by GRP stimulation also was inhibited by blockade of Src family kinases. These results suggest that Src family kinases contribute to GRP-mediated EGFR growth and invasion pathways by facilitating cleavage and release of TGF-alpha and amphiregulin in HNSCC.

Amphiregulin↗
PubMed2004

Overexpression of the NOTCH ligand JAG2 in malignant plasma cells from multiple myeloma patients and cell lines.

The NOTCH ligand, JAG2, was found to be overexpressed in malignant plasma cells from multiple myeloma (MM) patients and cell lines but not in nonmalignant plasma cells from tonsils, bone marrow from healthy individuals, or patients with other malignancies. In addition, JAG2 overexpression was detected in 5 of 5 patients with monoclonal gammopathy of undetermined significance (MGUS), an early phase of myeloma disease progression. This overexpression appears to be a consequence of hypomethylation of the JAG2 promoter in malignant plasma cells. An in vitro coculture assay was used to demonstrate that JAG2 induced the secretion of interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), and insulin-like growth factor-1 (IGF-1) in stromal cells. Further, the induction of IL-6 secretion was blocked in vitro by interference with anti-Notch-1 monoclonal antibodies raised against the binding sequence of Notch-1 with JAG2. Taken together, these results indicate that JAG2 overexpression may be an early event in the pathogenesis of multiple myeloma involving IL-6 production.

Cell Communication↗
PubMed2004

Gene structure and molecular analysis of Arabidopsis thaliana ALWAYS EARLY homologs.

Drosophila always early (aly) is essential for spermatogenesis, and is related to the LIN-9 protein of Caenorhabditis elegans; lin-9 is a class B Synthetic Multivulva gene (synMuvB) required for gonadal sheath development. Aly/LIN-9 have two conserved regions, called domains 1 and 2, which have been identified in homologous proteins from several multicellular eukaryotes, including the model plant Arabidopsis thaliana. We cloned and sequenced cDNAs of three different A. thaliana ALWAYS EARLY homologs (AtALY1, AtALY2 and AtALY3), analysed the expression pattern of these three genes and show that AtALY1, like Aly, is nuclear localised. We also demonstrate that the plant homologs of aly/lin-9 contain an additional N-terminal myb domain not present in the animal Aly/LIN-9 proteins, and that part of the ALY/LIN-9 conserved domain 1 in the predicted plant proteins is related to the TUDOR domain.

Amino Acid Sequence↗
PubMed2004

Deformations of promoter DNA bound to carcinogens help interpret effects on TATA-element structure and activity.

The TATA-box binding protein (TBP) is required by eukaryotic RNA polymerases for correct transcription initiation. TBP binds to the minor groove of an 8 base pair (bp) DNA-promoter element known as the TATA box and severely bends the TATA box. The promoter-DNA substrate can be damaged by components present in the cell or the environment to produce covalent carcinogen-DNA adducts. These may lead to transcription blockage or unfaithful transcription. Benzo[a]pyrene (BP) is a widespread environmental chemical carcinogen which can be metabolically converted to DNA-reactive enantiomeric (+) and (-)-anti-benzo[a]pyrene diol epoxides (BPDEs). Recent experimental studies of a pair of stereoisomeric adenine adducts, derived from (+) and (-)-anti-BPDEs, have revealed how these lesions influence the complexation of TBP with the TATA box. Depending on the adduct's location in the TATA box and its stereochemistry, the stability of monomeric TATA-TBP complexes was found to increase or decrease relative to the unmodified DNA. We report here analyses of molecular-dynamics simulations to interpret these findings. Structural analyses of 12 DNA-protein systems representing different combinations of adduct stereoisomer type and placement within the promoter reveal that the location of the adduct within the TATA octamer determines whether the stability of TATA-TBP complexes is increased or decreased. The effect on binding stability can be interpreted in terms of conformational freedom and major-groove space available to BP due to the hydrogen bonds and inserted phenylalanines of the TATA-TBP complex; that is, depending on the position of the adenine to which BP is covalently bound, BP can be accommodated in an intercalated or major-groove orientation with ease or with difficulty (due to interference with TATA-TBP interactions). The unravelled structures and interactions thus reveal the effect of different adduct locations on TATA-TBP complex formation and suggest how transcription initiation may be affected by the presence of a bulky BP.

Base Sequence↗