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Biomedical subjects

Q He

Publications and source records attributed to Q He.

At least 163 records · Page 9Linked to original sources
PubMed1998

Method for reduction of inhibition in a Mycobacterium tuberculosis-specific ligase chain reaction DNA amplification assay.

The present study describes the identification of inhibitors of a Mycobacterium tuberculosis-specific gap ligase chain reaction (LCR) DNA amplification assay as well as a method for their removal. A major contributor to inhibition was deduced to be a calcium phosphate precipitate, CaHPO4. The precipitate forms during N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH) decontamination, digestion, and concentration of respiratory specimens. The solubility product of CaHPO4 precipitate at pH 7.8, the pH at which gap LCR is optimized, indicates that the precipitate releases an amount of phosphate ions sufficient to inhibit amplification. A method for removal of the precipitate was identified. The precipitate is dissociated by exposing it to a mildly acidic (pH 4.1) buffer during the first of two centrifugation steps; the inhibitory phosphate ions are removed by the centrifugation steps. When 100 NALC-NaOH respiratory sediments were tested by gap LCR, none of the sediments were inhibitory when the acidic buffer was used while 24 samples were inhibitory when TE buffer, pH 7.8, was used. In another study, when the acidic buffer wash was applied to 1,440 NALC-NaOH respiratory sediments, only 10 sediments were found to be inhibitory. None of the inhibited sediments were culture positive for M. tuberculosis. This work demonstrates that when inhibition mechanisms are identified, relatively simple protocols can be used to obtain low inhibition rates and to allow the use of larger volume equivalents in amplification reactions.

Acetylcysteine↗
PubMed1998

[Clinical xenotransplantation: current progress, problems and solutions].

Xenotansplantation has become a global focus because it may solve the formidable problems in allotransplantation, that is, the donor source. Hitherto clinical xenotransplantion has been in the stage of research with limited cases and unsatisfactory results. The difficulties which hinder the progress of xenotransplantation include: the ideal animal donor has not been found, it is rather difficult to control the rejections (hyperacute rejection, acute vascular rejection, perhaps acute cellular rejection and chronic rejection) after xenotransplantation compared with those after allotransplantation, some animal diseases might be transmitted to and do harm to human recipients, even the community. It is still unknown whether the functions of animal organs can substitute those of human organs permanently. Transgenic pigs on research and various measurements to suppress humoral and cellular immunity may be helpful in overcoming the problems of xenogeneic rejections. Animal diseases should be prevented, screened and treated, and animal models should be established to study the possibility of satisfactory working of animal organs in human body before clinical xenotransplantation is widely practised.

Animals↗
PubMed1998

[Social and ethical issues of xenotransplantation].

The worldwide shortage in the supply of donor organs and tissues is becoming more pronounced. Xenotransplantation may probably give the hope to overcome the problem ultimately. However, it gives rise to a number of social and ethical issues, among them, the pig appears to be a likely source for human transplantation because it entails least social and ethical issues than no-human primates or other animals and the pig is similar to human in many aspects. The ethical and economic aspects must also be taken into consideration. Patient and his family's privacy may be stripped because the patient has received a new or unusual treatment. Xenograftings will squint towards a kind of commodities which are different from human graftings and it is a challenge to human transplantation. Xenotransplantation brings a risk of creating new human disease and pandemic, so, it is necessary to formulate a policy and provide input to draft guidelines on the regulation of xenotransplantation.

Animals↗
PubMed1998

[One-stage vagina reconstruction using the pudendal-thigh skin flap].

OBJECTIVE: This is to introduce a method for vagina reconstruction using the pudendal-thigh skin flap. METHODS: The pudendal-thigh skin flap has been used for vagina reconstruction in 70 cases since 1989. RESULTS: All the operations were successful and the method has become a mature technique. CONCLUSION: The advantages of the method are 1. the reconstructed vagina has good sensation and stable in maintaining its dimensions; 2. the linear scars of the donor site are hidden and inconspicuous; 3. the appearance of the perineum looks well; 4. the procedure is simple and favors its application.

Adolescent↗
PubMed1998

[Changes of serum myocardial enzymes in patients with malignant hematologic diseases].

Myocardial enzymes including aspartate aminotransferase (AST), lactate dehydrogenase (LDH), HBD (LDH1 and LDH2), and creatine kinase (CK) and its isoenzyme were monitored in 106 cases of malignant hematologic diseases. The findings were that average values of LDH and HBD increased. There were 82.4% myocardial enzyme levels of 51 patients with leukemia, lymphoma, and myelodysplastic syndrome (MDS) returning to normal or making an obvious reduction after chemotherapy associated with drugs of heart toxicity, while there were increases of the myocardial enzyme levels before chemotherapy. Patients with the increasing of enzyme levels were only 3.9% after chemotherapy. After several courses of chemotherapy, the positive rates of the increasings of CK and CK-MB were higher than that of pretreatment. The results suggest that the injuries of myocardium are possible.

Anthracyclines↗
PubMed1998

[Determination of valaciclovir polybutylcyanoacrylate nanoparticles].

The valaciclovir content of polybutylcyanoacrylate nanoparticles was determined by HPLC after dissolving the valaciclovir-poly butylcyanoacrylate nanoparticles in a solvent mixture. ODS-C18 column was used. The mobile phase consisted of CH3OH-0.02 mol/L KH2PO4 (20:80). The linear range was 2.02-20.20 micrograms/ml; the recovery 97.30%, and RSD 4.90%. This method is accurate and can be used for determining the contents of other nanoparticles.

Acyclovir↗
PubMed1998

[Preparation of acyclovir-polybutylcyanoacrylate-nanoparticles by emulsion polymerization method].

The aim of this study was to optimize the conditions and technology of preparing acyclovir-polybutylcyanoacrylate-nanoparticles (ACV-PBCA-NP) which has the diameter of about 100 nm and the shape of a sphere. The influential factors on sphericization were observed by single factor optimization. The preparation conditions and technology were optimized by the even design method. The contents of acyclovirin in acyclovir polybutyloganoacrylate nanoparticles were determined by HPLC. The optimum conditions and technology of preparing acyclovir polybutylcyanoacrylate nanoparticles were decided and put into use. The average diameter of the ACV-PBCA-NP thus prepared was 108.5 +/- 94.8 (n = 588). Its embedding ratio was 71.8%, and drug loading was 18.5%. The results suggest that the conditions and technology of preparing ACV-PBCA-NP presented in this paper are stable and practical.

Acyclovir↗
PubMed1998

[National epidemiological study on obesity of children aged 0-7 years in China 1996].

OBJECTIVE: To study on obesity of children aged 0-7 years in 11 cities in 1996. METHODS: The sampling size was 208, 513. The children were divided into 9 groups: birth-, 1 mo-, 6 mo-, 1 yr, 2 yr-, 3 yr, 4 yr-, 5 yr-, 6-7 yr. RESULTS: The prevalence of overweight was 4.2% (M4.2%, F4.2%); and of obesity, 2.0%(M2.2% F1.9%). The obesity to overweight ratio (ORR) was 2.1%(M1.9%, F2.2%). The adiposity rebound age (ARA) was 5 years. The adiposity rebound ratio (ARR) was 3.2 for ARR1 (M2.9%, F.5%) and 2.0 for ARR2 (M1.7%, F2.4%) in obese children and 3.5 for ARR1 (M 3.5, F3.5) and 2.5 for ARR2 (M2.8, F2.8) in overweight children respectively. The secular trend of prevalence of childhood obesity during 1986-1996 showed that the prevalence of obesity increased annually at 9.1% (M10%, F8.7%). CONCLUSION: The obesity has already been a severe health and social problem of preschool children in China. The increment of prevalence of obesity during 1986-1996 has been out of control. The earlier of ARA and the larger of OOR is an important risk factor of increasing of obesity. 1 year and 5 years after birth, predicted by ARR, are two critical periods of obesity control in preschool children in China.

Child↗
PubMed1998

[Investigation and analysis of the diagnostic status of bronchial asthma].

OBJECTIVE: The aim of this study was to investigate the rate of delayed diagnosis of the bronchial asthma and related factors. METHOD: 57 asthmatic outpatients were investigated randomly by questionnaire including main symptoms of asthmatic attack, the date of initial attack, the date of initial visit physician, and initial diagnosis, the basis of diagnosis and the names of misdiagnosed diseases. Then according to the above-mentioned data the duration of delayed diagnosis, the rate of delayed diagnosis were calculated. RESULT: 96% of outpatients saw physician within 1 yr. after initial attack. The duration from initial visit to making diagnosis were 11.1 +/- 2.3, and 1.5 +/- 0.3 yr. before and after 1980, respectively, and their rate of delayed diagnosis were 75%, 15%, respectively. Both of their differences were statistically significant (P < 0.01). Only 20% of diagnosis of asthma was by pulmonary function test. CONCLUSION: The majority of the delayed diagnosis should be due to making the mis-understanding and underattention of physician to the asthma, and their diagnostic levels should need further improving.

Adult↗
PubMed1998

[The role of glucocorticosteroid and theophylline in asthmatic inflammation of murine model and the inhibition in NO production in lung].

OBJECTIVE: To investigate the role of glucocorticosteroid and theophylline in treatment of asthmatic inflammation and their effects in production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS). METHOD: A murine model was set up (A group: asthma model, N group: control mice), then the number of WBC, eosinophils% (EOS), total protein level and the NO level in brochoalveolar lavage fluid (BALF) were measured after treatment with glucocorticosteroid (C1 group: dexamethason inhalation; C2 group: dexamethason peritoneal injection and C3 group: budisonide inhalation) and aminophylline(T group). The expression of iNOS was studied by histochemistry and immunohistochemistry. RESULT: There was a significant increase in number of WBC [(10.64 +/- 0.75) x 10(7)/L vs (3.15 +/- 0.92) x 10(7)/L, P < 0.001), EOS% (12.55% +/- 7.64% vs 0.02% +/- 0.04%, P < 0.001), total protein level (0.124 +/- 0.080 g/L vs 0.008 +/- 0.004 g/L, P < 0.001) and concentration of NO (5.00 +/- 1.87 mumol/L vs 1.30 +/- 0.67 mumol/L, P < 0.001) in BALF after antigen challenge, and the expression of iNOS was increased in airway epithelial cells and alveolar macrophages. After administration of steroids and theophylline, the number of WBC[C1: (5.05 +/- 1.14) x 10(7)/L, C2: (5.47 +/- 0.59) x 10(7)/L, C3: (6.53 +/- 0.47) x 10(7)/L, T: (3.65% +/- 1.04) x 10(7)/L, P < 0.001], EOS% (C1: 0.10% +/- 0.06%, C2: 0.10% +/- 0.08%, C3: 0.24% +/- 0.33%, T: 2.84% +/- 1.90%, P < 0.001-0.005), total protein level (C1: 0.016 +/- 0.011 g/L, C2: 0.010 +/- 0.008 g/L, C3: 0.020 +/- 0.012 g/L, T: 0.012 +/- 0.008 g/L, P < 0.001-0.05) were significantly decreased. There was a significant reduction of NO level (C1: 1.20 +/- 0.97 mumol/L, P < 0.001) and iNOS expression after treated with steroids, but no significant change after management with theophylline. CONCLUSION: EOS is main inflammatory cell in asthma. NO may play an important role in aggravating asthma. Steroids and theophylline both can inhibit cell infiltration and serum protein leakage in asthma. Steroids can also inhibit the production of NO and iNOS expression. But theophylline has no significant effect in NO.

Animals↗
PubMed1998

[Mechanism of Canscora lucidissima xanthones against arrhythmia induced by myocardial ischemia-reperfusion in rats].

OBJECTIVE: To study the protective effect of 1,8-dihydroxy-3,5- dimethoxyxanthone (Xan-I) 1-hydroxy-5-dimethoxyxanthone(Xam-II) and 1-hydroxy-3,7,8-trimethoxyanthone (Xan-III) on arrhythmia induced by myocardial ischemia-reperfusion injury and their mechanism. METHOD: A rat model was used. The experimental result shows that. RESULT: An intravenous injection of Xan-I, Xan-II and Xan-III 1 mg/kg given 3 min before left coronary artery ligation reduces significantly the incidence of ventricular arrhythmia and its duration, diminishes the release of glutamic oxaloacetic transaminase and lactate dehydrogenase, elevates the activity of superoxide dismutase and reduces the amount of malondialdehyde. The potency of the above effect among 3 Xans is Xan-I > Xan-III > Xan-II. CONCLUSION: It follows that the protective effect of Xans on myocardial ischemia reperfusion induced by arrhythmia might be associated with the reduction of myocardial lipid peroxidation and the enhancement of SOD activity, and the amount and site of-OH(hydroxy) and -OCH3 (methoxy) on the benzenoid structure may be related to the affinity of Xan.

Animals↗
PubMed1998

[Diagnosis and treatment of duodenal injury].

OBJECTIVE: To increase the value of early diagnosis and decrease postoperative complications of duodenal injury. METHOD: 16 patients with duodenal injury were treated and 5 patients were treated successfully with Modified Cogbill's techniques. RESULT: We emphasized the importance of early diagnosis and treatment of duodenal injury. CONCLUSION: The simplified techniques produce less complications and considered to be used clinically application.

Abdominal Injuries↗
PubMed1998

[Dynamic change of androgen-receptor in tumor and surrounding liver tissue of nude mice model with transplanted human HCC].

OBJECTIVE: To research into the law of androgen-receptor (AR) dynamic change in developing course of human HCC. METHOD: Dynamic measurement of AR in tumor and peritumorous tissue was performed in nude mice model with orthotopic transplanted human HCC. RESULT: Tumor nodules were present in 90% nude mice 4 weeks after transplantation, tumor necrosis was found in the 10th week, and remarkable necrosis occurred in the 12th week. The quantity of AR in tumor and peritumorous tissue was highest in the early stage of tumor (102.32 +/- 21.42 fmol/mg protein and 72.45 +/- 10.11 fmol/mg protein respectively), and then decreased progressively with time to the 10th week (40.98 +/- 21.11 fmol/mg protein and 53.39 +/- 7.01 fmol/mg protein respectively). The difference in AR between each two weeks was significant. CONCLUSION: Androgen promotes the development of tumor because of existence of AR, and its action may decline after establishment of tumor. Therefore, antiandrogen treatment may be ineffective after establishment of tumor.

Animals↗
PubMed1998

[Study on liver targeted valaciclovir polybutylcyanoacrylate nanoparticles].

The valaciclovir polybutylcyanoacrylate nanoparticles (VACA-PBCA-NP) were prepared by emulsion polymerization method. The morphology, size and size distribution, release characteristics in vitro, drug loading, stability and distribution of VACV-PBCA-NP in mice were studied. The results showed that the dav = 104.77 +/- 11.78 nm, drug loading was 11.20%. The release characteristics in vitro was in accord with two-phase kinetics. 74.49% of the VACV were concentrated in liver at 15 min after i.v. VACA-PBCA-NP. The amount of VACV entering hepatocytes was also increased greatly. This research seems to have important value for increasing the anti-hepatitis B virus effect and decreasing toxicity of VACV.

Acyclovir↗
PubMed1998

[Determination algorithms in oscillometric blood pressure measurement].

This paper discusses the method of oscillometric blood pressure determination. A new criterion for systolic pressure and diastolic pressure determination has been proposed, which is based on ratio changes of the oscillation amplitude under a wide normalized range. Primary experiment results show the new criterion is effective.

Algorithms↗
PubMed1998

[A multiexponential model in cavity ring-down absorption spectroscopy].

A multiexponential model of cavity ring-down absorption spectroscopy is established for taking into account the laser linewidth effects. It is demonstrated that by fitting the logarithmic ring-down function to a truncated polynomial, absorption coefficent can be extracted from coefficients of the first as well as higher order terms of the fitted polynomial. The new fit model results in higher accuracy and broader dynamic range than the previous single exponential model.

English Abstract↗