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Biomedical subjects

H Chen

Publications and source records attributed to H Chen.

At least 721 records · Page 40Linked to original sources
PubMed1999

[A study on ovariectomized goat osteoblast culture in vitro].

Osteoblasts were isolated from the frontal parietal bone of ovariectomized goat and were confirmed by testing for multiple biological features. The results showed that the goat osteoblasts cultured had the typical morphological feature of osteoblasts, the activity of alkaline phosphatase, and the ability of calcification in vitro. Also, the results proved that these goat osteoblasts in vitro had the same function and features as those in vivo. The experimental techniques in this study have provided a useful system for researches in bone metabolism.

Alkaline Phosphatase↗
PubMed1999

[Influence of sample dilution on separation and detection of DNA fragments by capillary electrophoresis].

Capillary electrophoresis has become an important and useful method to separate and determine DNA fragments. In molecular biochemistry, the volume of DNA sample is very small (microL level) and DNA sample is liable to be contaminated and degraded. According to theoretical inference and experiments, we propose that dilution of DNA sample solution can increase separation efficiency and resolution without evidently reducing height of peaks. By this method, the usage efficiency of DNA sample can be improved. It is also demonstrated the separation and detection of DNA fragments by capillary electrophoresis with hydroxyethyl cellulose non-gel sieving matrix and with laser-induced fluorescence charge-coupled device as detector. By using lower concentration non-gel matrix (0.4%), all 8 larger size fragments of lambda DNA/Hind III (125 bp-23 130 bp) can be completely separated. Twenty smaller size fragments of pBR322-Hae III DNA (18 bp-587 bp) can be separated by higher concentration (1.6%) non-gel matrix. As ratio of sample dilution is 10, two adjacent fragment (123 bp and 124 bp) of pBR322-Hae III DNA can be separated.

DNA↗
PubMed1999

[Analysis of organic acids in human dental plaque by means of gas chromatography/mass spectrometry].

The purpose of this study was to investigate the composition of plaque fatty acids in the healthy population. The study was made on 10 volunteers over the age of 18 who were divided into three sub-groups (3-4 individuals). Neither subject exhibited clinical evidence of salivary gland disorder and any medication affecting salivary functions were not used. A sensitive GC/MS method with VG7070E mass spectrometer was developed in our study. The sample separation was carried out on a fused silica capillary column with OV-1. The column size was 23 m x 0.23 mm. The temperature program was as follows: from 40 degrees C to 120 degrees C fast, then from 120 degrees C to 240 degrees C at 6 degrees C/min. The results showed that there were 14 organic acids and isomers present in plaque. They were C12:0, C14:0, C15:0, C16:0, C16:1, C18:0, C18:1, C18:2, C20:0 and phenylacetic acid, phenylpropionic acid. The higher content of fatty acids in the sample were C16:0, C18:0, and C18:1. The aromatic acids were detected only in some samples. The odd-numbers fatty acids and aromatic acids were for the first time detected. The origin of organic acids in plaque is an ongoing area of research. Our data clearly identify the bacterial contribution to the organic acids of plaque matrix, which may have a special relationship with bacteria metabolism. The research will help us to understand fatty acids metabolism of dental plaque and to determine their role in the microbial homeostasis of dental plaque.

Adult↗
PubMed1999

[The advances of research for problems of developing flow in blood vessel].

The development and the tendency of the problems of developing flow in the vessel are reviewed in this paper. It is pointed out that the problems of developing flow of viscoelastic blood vessel are front subjects, and that consideration shouldbe be give to three aspects, namely the blood flow, the blood vessel's wall motion and the coupling between the blood and the wall.

Blood Flow Velocity↗
PubMed1999

[Construction of a GFP broad-host-range promoter-probe vector and its application].

The 0.9 kb DNA fragment was obtained by PCR and using a pair of special designed primers from the green fluorescent protein gene(gfp). It Was then cloned into an expression vector pET-11C and named as pHN115. A promoferless gfp vector with SD fragment was obtained from pHN115 and subcloned into SK(+), pIJ 2925 and finally into pTR102. A broad-hast-range and visible promoter-probe vector, pHN127 was constructed and used successfully for the identification of constitutive and inducible promoters from Sinorhizobium fredii HN01.

Cloning, Molecular↗
PubMed1999

[Screening of acidic xylanase producing strain and studies on its enzyme production conditions].

From 150 fungal strains, the authors found 8 strains contained mainly of xylanase activity over 100 U/mL in which the No. 149 strain was the highest xylanase producer. Which tentatively identified as Aspergillas niger. The appropriate medium composition was as follows: wheat bran hemicellulose 4%; NaNO3 1%; wheat bran 1% prepared in Mandels nutritional solution without (NH4)2SO4 and urea. After cultivated in shake-flask at 28 degrees C-32 degrees C for 60 h, the activity reached the highest value of 357.2 U/mL. The optimum pH of xylanase was 4.6 and it was stable at pH3-11. The fermented broth of strain 149 contained in addition to xylanase (relative activity 100) also included amylase(1.8), mannanase(0.98), beta-xylosidase(0.94) and cellulase(0.17).

Aspergillus niger↗
PubMed1999

[Effects of IFN-gamma gene-modified hepatocytes on TGF-beta 1 and its receptor in mice infected with Schistosoma japonicum].

AIM: To explore the anti-schistosomal hepatic fibrosis effect and the changes in transforming growth factor-beta 1 (TGF-beta 1) and its receptors (TGF-beta RII) in S. japonicum infected mice after intrasplenic transplantation of gamma-interferon (IFN-gamma) gene-modified hepatocytes. METHODS: At 16 wk after infection with cercariae of Schistosoma japonicum, the mice were intrasplenically transplantated with murine hepatocytes which had been transfected with IFN-gamma gene-combinant adenovirus vector. ELISA, immunohistochemical and dot blot techniques were used to observe the dynamic changes in IFN-gamma, TGF-beta 1, TGF-beta RII and type I, III collagen. RESULTS: The intrasplenic transplantation of IFN-gamma gene modified hepatocytes effectively expressed IFN-gamma and obviously reduced the production and deposition of type I, III collagen as well as TGF-beta 1 and TGF-beta RII. CONCLUSION: IFN-gamma gene transplantation has anti-hepatic fibrosis efficacy in Schistosoma japonicum-infected mice, being related to its role of decreasing the expression of TGF-beta 1 and TGF-beta RII.

Animals↗
PubMed1999

[Studies on the chemical constituents of essential oil from roots and rhizomes of Patrinia rupestris].

OBJECTIVE: To study the chemical constituents of the essential oil from the roots and rhizomes of Patrinia rupestris. METHOD: The essential oil was extracted by steam distillation. The components were separated and identified by gas chromatography mass spectrometry and elucidated on the standard mass spectral data. Gas chromatography showed their percentages by area normalization method. RESULTS: Seventeen constituents were identified which make up 74.57% of the oil. CONCLUSION: Transcaryophyllene (38.41%) was the main constituent, and other constituents include alpha-gurjunene, caryophyllene oxide, humulene, 9,12-octadecadienoic acid, etc.

Gas Chromatography-Mass Spectrometry↗
PubMed1999

The killing effect of photodynamic therapy using benzoporphyrin derivative on retinoblastoma cell line in vitro.

OBJECTIVE: To evaluate the killing effect of photodynamic therapy (PDT) using new photosensitizer benzoporphyrin derivative complexed with human low density lipoprotein on retinoblastoma (RB) cell line in vitro. METHODS: The experiment of photodynamic killing effect on RB cell line in vitro was performed by using benzoporphyrin derivative (BPD or Verteporfin) and monochromatic light at the wavelength around 690 nm. Seven BPD concentrations (2,500 ng/ml, 1,250 ng/ml, 625 ng/ml, 312.5 ng/ml, 156.25 ng/ml, 78.125 ng/ml, 39.0625 ng/ml) and three energy densities (1.2 J/cm2, 2.4 J/cm2 and 3.6 J/cm2) were applied. The damage of the tumor cells was evaluated by MTT assay 24 hours after PDT. The changes of the ultrastructure of RB cells were observed under eleceronic microscope 4 hours after PDT. RESULTS: There was a significant dose-response relationship between tumor cell damage and BPD concentration in the medium under light irradiation at the energy density of 1.2 J/cm2. At each BPD concentration, the inhibition rate increased with the rise of energy density. RB tumor cell necrosis was found widely under electronic microscope. CONCLUSIONS: This study suggested that RB cells are very sensitive to the PDT induced by BPD in vitro. RB tumor cell were directly killed by photodynamic effect induced by BPD.

Cytotoxicity, Immunologic↗
PubMed1999

A study on the compliance of the patients with ocular fundus diseases.

PURPOSE: To investigate the compliance of the patients with ocular fundus diseases with recommendation for follow-up examination after laser treatment, and the underlying reasons for non-compliance. METHODS: 53 patients with ocular fundus disease were asked to fill in a questionnaire which includes the socio-demographic characteristics, fear of the fundus disease, conception of the laser treatment and the motivation for staying healthy. Variables were compared for the compliers group and the non-compliers group by chi-square test. RESULT: Of the 53 subjects, 35 were classified as non-compliers and 18 were classified as compliers. There was no statistically significant difference between the two groups on all selected socio-demographic factors, conception of the laser treatment and the motivation for staying healthy. Significant difference was found between the two groups on two of those items concerning the fear of the diseases (P < 0.05). About half of the participants showed the lack of knowledge about the laser treatment. CONCLUSION: The present study revealed the poor compliance of the patients with fundus disease. Patient's health beliefs influenced their compliance status.

Adult↗
PubMed1999

[Development of the automatic dental X-ray film processor].

This paper introduces a multiple-point detecting technique of the density of dental X-ray films. With the infrared ray multiple-point detecting technique, a single-chip microcomputer control system is used to analyze the effectiveness of the film-developing in real time in order to achieve a good image. Based on the new technology, We designed the intelligent automatic dental X-ray film processing.

Equipment Design↗
PubMed1999

[Effect of shen-dong-xin-bao oral liquid on IFN-induction and NK cell activity in CVB3m infected mice].

OBJECTIVE: Our aim was to investigate the effect of Shen-dong-xin-bao oral liquid on IFN-induction and NK cell activity in mice with coxsackie virus B3(CVB3m) infection in different infective stages. METHODS: The level of serum interferon (IFN) and the activity of natural killer (NK) cells in CVB3m induced myocarditis in mice were determined. Natural killer cell cytolytic activity was tested by MTT method and interferon titers by 50% microcytopathic effect assay. RESULTS: In the infected mice fed with 30 g/kg or 12 g/kg per day of Shen-dong-xin-bao oral administration for 10d and 20d, the mean titers of IFN were markedly higher than that in untreated infected group, P < 0.05. The NK cell activity in treated infected groups was also prominently higher than that in untreated infected group, especially on 20d, P < 0.05. CONCLUSION: This results demonstrate that administration of Shen-dong-xin-bao oral liquid possesses enhancement of antiviral immunocompetent action.

Animals↗
PubMed1999

[Analyze T lymphocyte subsets of HIV/AIDS patients by flowcytometer].

OBJECTIVE: Using flowcytometer (FCM) to detect CD4+, CD8+ lymphocytes in peripheral blood, combine with clinical symptoms to evaluate the HIV/AIDS patients' immune state. METHODS: Anti-coagulated peripheral blood were obtained from 8 HIV-AIDS patients and 5 normal persons. After analyzing their total white cell counts, the whole blood was stained with two-color immunofluorescence using directly conjugated monoclonal antibody pairs, followed by lysis of red erythrocytes, fixation of lymphocytes, and analysis by flowcytometry. Multiplying the CD4 and CD8 percentages by the absolute number of lymphocytes obtained from the total white blood cell (WBC) count divide by the lymphocyte differential percentage, we got the CD4, CD8 counts. RESULTS: The HIV/AIDS patients' CD4 counts were lower than those of normal controls'. Especially, the AIDS patients' CD4 counts were all below 200 cells/mm3 and their clinical symptoms were serious. CONCLUSION: The HIV/AIDS patients' CD4 counts are highly correlated with their clinical symptoms. The result also shows that FCM is accurate, sensitive and reliable in CD4 count.

Acquired Immunodeficiency Syndrome↗
PubMed1999

[The detection of virus antigen in the lower respiratory tract of the patients with lung cancer].

OBJECTIVE: To find out about the viral infection situation of lower respiratory tract of the patients with lung cancer. METHODS: The excretion from the surface of bronchiogenic carcinoma was brushed under fibrobronchoscopy. The respiratory virus antigen was detected and analysed by reagent kit produced by the 262nd Hospital of Beijing Military Region. RESULTS: The respiratory virus antigen was positive in eight cases of lung cancer group, the positive rate was 17.4%(8/46), it was significantly higher than that in non-lung cancer group (P < 0.05). Among them, there were one case of influenza virus A, two cases of influenza virus B, two cases of para-influenza 1,3, two cases of adenovirus and one case of respiratory syncytial virus. The carcinoma accompanied with viral infection were 4,3,1, cases in order of squamous carcinoma, small cell lung carcinoma and adenocarcinoma. CONCLUSION: The results showed that a relationship existed between lung cancer and viral infection of respiratory tract statistically. The viral infection increased in patients with lung cancer, this is worthy to pay attention to.

Adult↗
PubMed1999

[The applied anatomy of the periosteal flap composed of submental artery and dgastric muscle].

OBJECTIVE: To provide anatomical basis for a new style operation using periosteal flap composed of submental artery, anteroventral portion of digastric muscle and submental artery for the renovation of laryngotrachea. METHODS: The anatomical structures correlative with submental artery, submental vein, anteroventral portion of digastric muscle and mandibular periosteum in 23 (46 sides) cephalocervical samples were measured. RESULTS: The periosteal flaps had shown many advantages inculding large transfer capacity, rich blood supply, flexibility. CONCLUSION: It is feasible that the periosteal flap composed of submental artery, anteroventral portion of digastric muscle and mandibular periosteum is useful laryngotracheal renovation.

Arteries↗
PubMed1999

[Spectroscopic study of the 1pig Rydberg states of Na2].

Six highly excited 1pig states of the Na2 molecule have been investigated by optical-optical double resonance (OODR) flourescence excitation spectroscopy. Absolute vibrational numberings are determined and molecular constants and RKR potential curves are obtained. The lowest 10 1pig states have been relabeled according to the hydrogenic nllambda characters of the Rydberg orbital and classified into core-penetrating and core-nonpenetrating Rydberg states.

English Abstract↗
PubMed1999

[Information system for ICP-AES in windows environment].

An information system for inductively coupled plasma atomic emission spectrometry (ICP-AES) in MS Windows environment was developed based on the previous work in the labroatory. The system contains the data of about 28 000 spectral lines and a function of ICP spectral simulation, so it would be very helpful for line selection. The system also contains the Kalman filter and factor analysis programmes written with MS Visual Basic(version 4.0), which can be used for spectral interference correction and peak position optimization. A large amount of real spectral scanning data of rare earth elements were included in the system for user's references. All these characteristics made the system more useful and practical.

English Abstract↗