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Biomedical subjects

Q Chen

Publications and source records attributed to Q Chen.

At least 361 records · Page 20Linked to original sources
PubMed1999

[Changes in p50 and oxygen metabolism during mild hypothermia cardiopulmonary bypass].

OBJECTIVE: To study the changes of p50 and oxygen metabolism during mild hypothermia cardiopulmonary bypass, arterial blood lactate(ABL) were measured, arterial and venous blood gas were analysed in 21 patients undergoing cardiac valve replacement. RESULTS: p50, oxygen consumption(VO2), and oxygen extract rate(ERO2) were decreased during hypothermia and increased during rewarming, respectively (P < 0.05 or P < 0.01), while the change of SvO2 was adversed. PvO2 was decreased significantly during rewarming(P < 0.01), and ABL was continuously increased. CONCLUSION: Both reduction in oxygen utilization during hypothermia and relative deficiency of oxygen supply during rewarming cause tissue hypoxia.

Adult↗
PubMed1999

[Changes of simple epithelial cytokeratin during oral carcinogenesis].

OBJECTIVE: To investigate whether the simple epithelial cytokeratin CK18 and CK19 can be used as a marker of oral precancerous lesions. METHODS: Formalin-fixed, paraffin-embedded tissue sections of normal oral mucosa, epithelial hyperplasia, mild epithelial dysplasia, moderate epithelial dysplasia, severe epithelial dysplasia and oral squamous cell carcinomas were stained with a CK18-specific antibody and CK19-specific antibody respectively by LSAB immunohistochemical method. The stained sections were observed under light microscopy. The results were described and analyzed with Rank Sum Test. RESULTS: CK18 was not detected in normal and abnormal oral tissue sections. But in normal nonkeratinized mucosa, CK19 was detected in the basal cell layer dispersively. In epithelial dysplasia, CK19 was detected in the suprabasal cell layer and the number of CK19-positive cell layers was correlated with the dysplasia degree of epithelia. Furthermore, CK19 was detected in oral squamous cell carcinoma, especially in the poor-differentiated cancer cells. CONCLUSION: CK19 expression in suprabasal cell layer of oral mucosa can be used as a candidate marker for diagnosis of oral precancerous lesions and determination of the differentiation level of oral squamous cell carcinoma.

Biomarkers, Tumor↗
PubMed1999

[Expression of CDK4 protein in oral carcinogenesis].

OBJECTIVE: To study the expression of cyclin dependent kinase 4(CDK4) protein in oral carcinogenesis. METHODS: An LSAB immunohistochemistry method was applied to 80 cases of paraffine-fixed tissues to study the expression and distribution of CDK4 in normal oral mucosa, oral premalignant lesion (OPL) and oral squamous cell carcinoma. RESULTS: The overexpression of CDK4 protein was observed in the progression of OPL. Meanwhile, a correlation analysis was applied to investigate the relationship between P16 and CDK4 expression, and the result showed that the coefficient of correlation was 0.813, which was statistically significant. CONCLUSION: The overexpression of CDK4 is involved in the progression of OPL, and there is a positive feedback loop between CDK4 and P16.

Cyclin-Dependent Kinase 4↗
PubMed1999

[Psychological aspects of patients with burning mouth syndrome: an investigation of personality, psychopathological profiles and social life background stress].

OBJECTIVE: To know the psychosocial background of patients with burning mouth syndrome (BMS) in China. METHODS: In this study, 30 patients with BMS and 30 normal subjects of control group were evaluated for their personality, psychopathological profile and existence of recent life events. All subjects were required to complete the EPQ questionnaire, the SCL-90 questionnaire and a Life Event Scale, and chi-square test analysis of variance and rank sum test were used in this study. RESULTS: The personality of introversion and instability was common in BMS group. The scores of 9 emotional factors and negative life events were higher than that of the control group significantly. CONCLUSION: BMS may be a series of psychological disorder and somatic discomfort caused by stresses of social life events on the people with special personality.

Burning Mouth Syndrome↗
PubMed1999

[Determination of inosine 5'-monophosphate and guanosine 5'-monophosphate in taste-enhancers by ion chromatography].

A high performance anion-exchange chromatographic method was developed for the simultaneous determination of two kinds of taste-enhancers, inosine 5'-monophosphate (IMP) and guanosine 5'-monophosphate (GMP), in the presence of monosodium glutamate and chloride (salt). The separation was achieved by using Dionex IonPac AG11 and IonPac AS11 columns, and the determination by ultraviolet absorbance detection at 254 nm. The detection limits (S/N = 3) were 0.21 mg/L and 0.27 mg/L for IMP and GMP, respectively. Good linearities between the concentrations of the two analytes and relevant peak area responses were obtained in the range of 2-100 mg/L. Under the experimental conditions, glutamate, chloride, succinate, benzoate, sorbic acid and citrate did not interfere in the determination of IMP and GMP. The method has been successfully applied to the determination of IMP and GMP in gourmet powder as well as chicken bouillon, and the average recoveries for various samples ranged from 97% to 103%.

Calibration↗
PubMed1999

[A primary clinical study of HRV analysis of nonlinear dynamics].

We observed the changes of nonlinear dynamic parameters in the patients with diabetes and old myocardial infarction with the methods of nonlinear dynamics. The results indicate that the correlation dimension of the patients with old myocardial infarction is higher than that of the normal, their Lyapunov exponent is lower than the normal's; that the correlation dimension of the patients with diabetes is also higher than that of the normal, their Lyapunov exponent is lower than the normal's; and that the values of the entropy of the two patient groups are basically identical to the entropy of the normal. Therefore the correlation dimension can indicate the changes in the function of autonomic nerve of the patients with diabetes and old myocardial infarction.

Autonomic Nervous System↗
PubMed1999

[Studies on degradation of poly-(propyl,3-hydroxypropyl)-DL-asparamide and release of conjugate linking aspirin in vivo and in vitro].

Two polyasparamide derivants having different hydrophilicities were selected to be degraded in vivo and in vitro. The results demonstrate that the degradation process of polyasparamide is enzymatic hydrolysis. Materials with different hydrophobicities are different in degradation rate and the same material has different metabolic rates in the planting position, kidney and liver. The release results of two polymeric drugs indicate that protease is of advantage to release of drug, and hydrophobicity of material is also an advantage to the release.

Animals↗
PubMed1999

[A water-soluble synthetic polymer, alpha,beta-poly(hydroxyalkyl)-DL-asparamide, and conjugating drug].

A water-soluble polymer alpha,beta-poly (hydroxyalkyl)-DL-asparamide was synthesized by polysuccinimide(PSI) and different lengths of hydroxyalkyls, including alpha,beta-poly(hydroxyethyl)-DL-asparamide(PHEA), alpha,beta-poly(hydroxypropyl)-DL-asparamide(PHPA), and alpha,beta-poly(hydroxybutyl)-DL-asparamide(PHBA). These polymers were characterized by differential scanning calorimetry(DSC) and infrared spectrophotometry(IR). Stability and acutetoxicity of these polymers were studied. The experiment indicated that these materials were of low-toxicity and high stability. Acetylsalicylic acid, as a model drug, was conjugated into polymers; the drug loadings were 38.63%, 37.68% and 38.70% respectively. Polymer drugs were made into cylinder, and in-vivo release in rabbits was set out. It showed that the longer the spacer was linked into the polymer, the faster the drug was released.

Animals↗
PubMed1999

[Treatment of chronic prostatitis with computerized herbal drug penetrator].

A computerized herbal drug penetrator for chronic prostatitis was designed and developed on the basis of a combination of the authors' clinical practice with modern Traditional Chinese Medicinal theories. The device has integrated many hi-techs of current engineering science. It works by applying special herbal medicine, electro-magnetic effects, thermal moxibustion, perfusion and pulsated massage with water-capsule. The result of using this technique in the treatment of 100 cases has demonstrated its satisfying effectiveness.

Acupuncture Therapy↗
PubMed1999

[On the biomechanical reasons why children are liable to have fracture in supracondyle of humerus].

With the viewpoint of biomechanics in theory, this paper analyses why children are liable to have fracture in supracondyle of humerus as a result of falling to the ground with the upper limbs propping up the body while adults usually have fracture in the middle or upper part of humerus under the same condition. The focus of discussion is the change of front-inclination in the lower end of humerus in the process of bone maturity from childhood to adulthood.

Adult↗
PubMed1999

[Ion chromatography of L-ascorbic acid, sulfite and thiosulfate using their postcolumn reactions with cerium (IV) and fluorescence detection of cerium (III)].

An ion chromatographic method was used to separate the species of L-ascorbic acid, sulfite and thiosulfate in their mixtures. This method is based on the separation of each anion in their mixtures by using a separation column, and then on the fluorimetric measurement of cerium (III) formed by a postcolumn reaction of cerium (IV) with the species of L-ascorbic acid, sulfite and thiosulfate in the effluent. The optimal conditions for separating and determining the above three species have been established. By using a 3 mmol/L carbonate eluent, the species of L-ascorbic acid, sulfite and thiosulfate could be eluted at the proper retention times of 1.7, 2.6 and 5.0 min, respectively, and these three anions could be separated completely. The effects of the concentrations of cerium (IV) and sulfuric acid in the postcolumn reaction solution on the chromatographic peak-height were tested in order to obtain the optimal peak-height. It was found that the peak-height at first increases rapidly with an increase in the concentration of cerium (IV) and sulfuric acid respectively up to a certain concertation, then increases slowly. These critical concentrations of cerium (IV) and sulfuric acid also depend on the amount of the analyte injected. Meanwhile the baseline signals of the sepectra increase with an increase in the concentration of cerium (IV). Some concentrations above the critical concentration of sulfuric acid could be selected as the optimal concentration of sulfuric acid, but the concentration of cerium (IV) should be optimized by establishing a compromise between the higher peak-height and the lower baseline signal. The detection limit of this method was found to be 1 mumol/L for thiosulfate when an amount of 100 microL analyte was injected.

Ascorbic Acid↗
PubMed1999

[The use of AFLP technique for the study of genetic diversity in peanut bradyrhizobia].

A total of 146 bradyrhizobial strains including 133 peanut bradyrhizobia isolated from different regions and 13 reference strains representing B. japonicum and B. elkanii were studied for their genetic diversity by use of AFLP marker technique. The genomic similarity was analysed by numerical Taxonomy based on the AFLP patterns. The results showed that the genetic diversity of peanut bradyrhizbia were very high. Each strain had a identical AFLP pattern. AFLP technique is simple, fast, highly reproducible, and is a useful tool for evaluating genetic diversity.

Arachis↗
PubMed1999

[Use of diagnostic ultrasound of sinus in the paranasal sinus disease].

OBJECTIVE: To utilize the diagnostic A ultrasound of sinuses in the diagnosis of paranasal sinus disease. METHOD: Through history enquirement, careful clinical otorhinolaryngological examination, X-ray examination of paranasal sinus, CT, maxillary sinus puncture and examination of the diagnostic ultrasound of sinus, we observed 115 patients with paranasal sinus disease and compared them with 22 normal people who were in control group. RESULTS: In normal people, the according rate between ultrasound examination and clinicaly diagnostic methods, include history enquirement, otorhinolaryngological examination, X-ray examination, CT and maxillary puncture, is 100%. And in the group of patients with paranasal disease, the according rate is 62.5%-92%. CONCLUSION: The diagnostic A ultrasound of sinus has high accuracy, the control is easy, the cost is relatively lower, it can be used repeatedly and do no harm to the patient's health. It is a good method and assistant technigue in the diagnosis of frontal and maxillary sinus disease.

Adolescent↗
PubMed1999

[The immunological cause of auricular pseudocyst].

OBJECTIVE: To elucidate the relationship between the auricular pseudocyst and the systemic and local immunological status. METHODS: The cyst fluid and blood samples of 44 cases were collected to measure contents of IgG, IgA, IgM and complement C3 by radial immunodiffusion, the content of immune complex by polyethylene glycol turbidimetry, DNA of cytomegalovirus in the fluid by polymerose chain reaction, anti-nuclear antibody(ANA) by immunofluorescent technique and reactions between samples and frozen sections of healthy white rat. RESULTS: Contents of IgG, IgA, IgM and C3 in the cyst fluid were significantly lower than those in the serum (P < 0.01). No immune complex could be detected in both serum and cyst fluid. No DNA of cytomegalovirus was found in cyst fluid, whereas ANA was discovered. Reactive immunocomplex in the auricular cartilaginous tissue was found in the frozen sections of white rats. CONCLUSION: The results suggest that auriular pseudocyst may be an autoimmune disease involving the auricle. The possible mechanism may be an accumulation of reactive exudate due to immunoreactions of autologous antibody and auricular tissue.

Adult↗
PubMed1999

[Observation in vivo histological response induced by imlplanted domestic poly-DL-lactic acid plates]

OBJECTIVE:To analyze the histological response and biocompatibility to implanted domestic PDLLA plates in vivo METHODS:Bilateral artificial fractures were created in mandibular bodies in dog and internal fixed with domestic PDLLA plate,TM plate respectively;meanwhile,a domestic PDLLA plate was imlplanted in femur.The interfacial soft tissue around the plates were collected and performed histological study RESULTS:All the skin wound healed well without abscess and fistula formation. From 2 to 4 weeks after the operation,the inflmmatory granulomatous response around the intenal fixation PDLLA plates was more serious than that of the control,in which more macrophages,plasmocytes and less lymphocytes,mononuclear cells infiltrated CONCLUSION:Domestic PDLLA plate is an inert internal fixation material with good biocompatibility, which induced a non-speciflc foreign reaction

Journal Article↗
PubMed1999

[Observation of the biodegradation of domestic poly-DL-lactic acid plates in vivo]

OBJECTIVE:To analyze the degradation and related factors of domestic poly-DL-lactic acid(PDLLA) plates in vivo. METHODS: The artifical transverse fractures in mandibular bodies of dogs were created and internal fixed with domestic PDLLA plates as experimental group,the implanted PDLLA plates in femurs as control.A certain time after the operation,the plates in fractured and implanted regions were collected and undertaken macroscopy and scanning electromicroscopy(SEM),meanwhile the fracture-healing status was evaluated. RESULTS: With time going on,the surface of domestic PDLLA plates y and density of micro-holes among poly-DL-lactic acid molecules in the PDLLA plates increased gradually.16-20 weeks Domestic PDLLA plates can be gradually biodegradation in vivo,in which it is correspondent with and accelerative the fracture-healing process.

Journal Article↗
PubMed1998

Blood cells with reduced mitochondrial membrane potential and cytosolic cytochrome C can survive and maintain clonogenicity given appropriate signals to suppress apoptosis.

Reduction of mitochondrial membrane potential (Psim) and release of cytochrome c from mitochondria appear to be key events during apoptosis. Apoptosis was induced in IC.DP premast cells by the withdrawal of interleukin-3 (IL-3). Psim decreased by 12 hours and cytochrome c was detected in the cytosol at 18 hours. Despite these changes in the mitochondria after 18 hours of IL-3 deprivation, clonogenicity was unaffected when IL-3 was replenished at 18 hours. Activation of v-Abl tyrosine kinase (v-Abl TK) in IC.DP cells before IL-3 depletion led to increased levels of Bcl-XL, prevented reduction of Psim and the release of mitochondrial cytochrome c, and suppressed apoptosis. Activation of v-Abl TK 18 hours after withdrawal of IL-3 when </=10% of the cells had died restored Psim in the remaining cells. More than 40% of cells thus rescued by v-Abl TK between 18 and 42 hours could subsequently form colonies in the presence of IL-3. These data suggest that reduction in Psim precedes loss of mitochondrial cytochrome c in IC.DP cells; that v-Abl TK activation, probably via upregulation of Bcl-XL, prevents loss of Psim and blocks the release of cytochrome c from mitochondria; and that neither of these mitochondrial events is sufficient for commitment to apoptosis.

Animals↗