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H Wang

Publications and source records attributed to H Wang.

At least 1,729 records · Page 96Linked to original sources
PubMed1997

[Study of optimal parameters and normal values for auditory P300].

Study of optimum seeking method with orthogonal test for auditory P300 measuring was carried out in healthy adolescents. The result showed that the optimal conbination of parameters was as follows: stimulus sound was Logon, recording electrode site Cz, analysis time 750 ms, average 100, stimulus rate 1 c/s, target stimulus (TS) probability 10%, bandpass filter 1-50 Hz, non-target stimulus (NTS) freqency 1 kHz, target stimulus (TS) frequency 2 kHz, stimuli intensities 110 dB peSPL. The normal values of auditory P300, obtained from 30 healthy adolescents, including latencies and amplitudes, were measured under optimal parameters. P300 latency was about 310 ms, RT about 258 ms, these two values present a significant linear correlation.

Adolescent↗
PubMed1997

[The development of a laser back-scattering erythrocyte-aggregometer].

In this paper, an erythrocyte-aggregometer based on the analysis of the light intensity back-scattered by a blood suspension is presented and described in detail. It allows to approach aggregation phenomenon in terms of kinetics, structural and rheological parameters. A personal computer and a microcomputer are applied to automate the system's sampling, data-processing and data-restoring procedure.

Equipment Design↗
PubMed1997

[The development of a fluid percussion device for brain injury of animals].

This paper discusses a fluid percussion device for brain injury. The injury is produced by striking the cork with a pendulum dropped from a known fall height to produce transient high pressure through a fluid transfer system. Experimental results show the device has the advantages of making a controllable, repeatable, and precise injury, and it can produce different levels of injury on different animals.

Animals↗
PubMed1997

Spatiotemporal characteristics of central otolith neurons.

PURPOSE: To review the spatiotemporal behaviours of central otolith neurons in decerebrate animals. DATA SOURCES: Laboratory of Neurophysiology, Department of Physiology, Faculty of Medicine, The University of Hong Kong. DATA EXTRACTION: Results of key research findings from 1992 to 1997. RESULTS: With constant velocity colckwise (CW) and counterclockwise (CCW) off-vertical axis rotations as stimuli to the otolith organs, neurons in the vestibular nuclei and medullary reticular formation showed characteristic spatiotemporal behavious. One-dimensional neurons showed symmetric and stable bidirectional response sensitivities (delta) to change in velocity while two-dimensional neurons showed asymmetric and variable delta to velocity. This CW-CCW asymmetry to bidirectional rotations may provide directional coding in the modulation of neural signals. Vestibular nuclear neurons also displayed distinct spontaneous discharge patterns at the stationary and earth-horizontal position, indicating that one- and two-dimensional neurons belong to physiologically distinct etities. These spatiotemporal behavious of the vestibular nuclear neurons were also shown to be precisely controlled by imputs from the vestibulocerebellum and/or bilateral otoliths. In both the vestibular nucleus and the reticular formation, the best response orientations of one-dimensional neurons and the orientations of the maximum response vector of two-dimensional neurons were found to point in all directions close to the horizontal plane, indicating that all head orientations on this plane are encoded across an ensemble of neurons. CONCLUSION: Otolith-evoked behaviours of the one-dimensional and two-dimensional neurons constitute an important element for the recognition of the direction and orientation of head motion in space.

Animals↗
PubMed1997

Comparative study of the effects of ouabain and digoxin on blood pressure of rats.

OBJECTIVE: To compare the effect of ouabain on the blood pressure of rats with that of digoxin to find the evidences of the relationship between endogenous ouabain (EO) and development of hypertension. METHODS: Sprague-Dawley rats, which were divided into 3 groups, were infused with ouabain (23 x 75 micrograms.kg-1/day, i.p.), digoxin (36 x 84 micrograms.kg-1/day, i.p.) and normal saline (NS) once a day respectively. Systolic blood pressure and body weight were recorded weekly. Five weeks later, rats of ouabain group were randomly assigned to three infusion subgroups: Oc group, continued with ouabain infusion; Od group, added digoxin (73 x 68 micrograms.kg-1/day, i.p.) and Os group, stopped administration of ouabain. Another week later, direct blood pressure was recorded in aorta. Systolic and diastolic cardiac function, plasma renin activity and aldosterone levels of all the rats were measured. RESULTS: After a latent period of one week, blood pressure of Ouabain group increased significantly [95.4 +/- 11.8 mmHg (1 mmHg = 0.133 kPa) at the beginning of the experiment vs 122.5 +/- 16.9 mmHg at the end of week 6, P < 0.05] with normal plasma renin activity and higher aldosterone (1.28 +/- 0.45 ng/ml vs 0.69 +/- 0.27 ng/ml, P < 0.05). The blood pressure decreased after either withdrawal of ouabain or addition of digoxin (116.3 +/- 14.4 mmHg vs 100 +/- 10.7 mmHg, P < 0.05; 123.9 +/- 13.9 vs 103.3 +/- 10.5 mmHg, P < 0.05, respectively). No difference of blood pressure was found between the digoxin and NS group. CONCLUSIONS: Our results suggested that EO might be one of the causes of the development of hypertension. Aldosterone might play some role in the mechanism of ouabain-induced hypertension. Digoxin can not induce hypertension. There is a great difference between the effect of ouabain and digoxin on the blood pressure. Moreover, digoxin can reverse the hypertension induced by ouabain.

Animals↗
PubMed1997

[Relationship between human papillomavirus E7 protein and Rb gene product in fresh tissues of squamous cervical carcinoma].

OBJECTIVE: To study the possibility of complex formation of the E7 protein encoded by human papillomavirus (HPV) binding to retinoblastoma gene product (pRb) in fresh samples of squamous cervical carcinoma (SCC). METHODS: HPV 6/11, 16, 18, 33 DNA were detected in 40 samples of by polymerase chain reaction technique (PCR). The complexes of HPV E7-pRb were examined in fresh tissues of HPV contained SCC through capture enzyme linked immunosorbent assay (capture-ELISA). RESULTS: 45.0% (18/40) of the samples were proved to be HPV positive by PCR. Out of 18 samples with HPV positive samples, the complexes of HPV E7-pRb were detected in 9 cses, including 1 HPV18 positive and 8 HPV16 positives. The complexes of HPV E7-pRb were not found in 2 cases of positive HPV 6/11. No correlation was observed between the E7 protein binding to pRb and the histological grade of cervical carcinoma (P < 0.05). There was correlation with clinical staging, the number of cases showing that the E7 protein pRb complex in stage I was significantly higher than that in stages II-IV (P < 0.05). CONCLUSIONS: The complex of "high risk" HPV E7-pRb was demonstrated in fresh tissues of SCC. There is no correlation between the complex and histological grade of SCC. The complex formation may occur in the early developmental stage of cervical cancer.

Carcinoma, Squamous Cell↗
PubMed1997

[Determination of fetal umbilical artery flow velocity during induction of term labor by mifepristone].

OBJECTIVE: To evaluate the effects of mifepristone for induction of term labor on blood supply of placenta. METHODS: 97 pregnant women (38-42 gestational weeks) were recruited, and randomly allocated into 2 groups, group 1 (n = 49) mifepristone was given orally 50 mg q12h for 2 days followed by misoprostol intravaginally (25 micrograms q12h); group 2 (n = 48), Sodium prasterone sulfate intravenous injection of 200 mg qd for 3 days followed by oxytocin intravenous infusion. Fetal umbilical artery flow velocity was determined before and 36-48 hours after treatment to observe the variation of S/D value in both groups. RESULTS: There were no significant variations of S/D value in both groups (P > 0.05). CONCLUSIONS: Mifipristone for induction of term labor (50 mg q12h for 2 days) is effective, and has no significant influence on the blood supply of placenta.

Abortifacient Agents, Steroidal↗
PubMed1997

[Experimental study on free grafting of fat particles].

Forty-eight rats were used to study the change in fat tissue after grafting. In the experimental group, the fat tissue to be grafted was treated with insulin. Evaluation was made by graft measurement, ink injection, light microscopic and electronic microscopic observations. The results showed that the volume of the grafted fat decreased obviously and there was no significant difference between the experimental and the control groups in the change of volume of the grafted fat tissue. At the early stage of grafting, the grafted fat showed ischemia. The adipocytes released lipid and dedifferentiated to preadipocytes. After revascularization, the preadipocytes began to absorb lipid and became mature adipocytes. The structure of the grafted fat was almost normal at 6 months after grafting. The formation of the cytoskeletal filament, found by ultrastructural study, was closely related with the synthesis of lipid.

Abdominal Muscles↗
PubMed1997

[Detection of p53 gene mutation in paraffin-embedded asbestos-related lung cancer tissue].

Paraffin-embedded asbestos-related lung cancer tissue of ten cases was analyzed with polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) to study its genetic mutation of exon 5, 7 and 8 of anti-oncogene p53 by silver stain. Results showed that fragment of exon 7 or 8 of p53 gene in four cases was positive in silver-staining analysis of PCR-SSCP. Exon 7 or 8 fragments of p53 gene was detected positive for mutation in seven of these ten cases with autoradiographic analysis of PCR-SSCP. No exon 5 fragment was found positive for mutation in these ten cases with both methods. Agreement between results of silver staining and those of autoradiographic PCR-SSCP was 60%. Hence, autoradiographic method could be replaced by silver staining, a simpler and more sensitive one, in PCR-SSCP to study gene mutation of asbestosrelated lung cancer.

Adenocarcinoma↗
PubMed1997

[Autopsies of five coal workers with pleural plaque].

Data from autopsies for 200 coal workers were analyzed to study the significance of pleural plaque in diagnosis for pneumoconiosis. Parietal Pleural plaques were found in them. Macroscopically, pleural plaques could be divided into two types, one smooth and the other nodular. Under microscope, typical pleural plaques were composed of a basket-woven, coarse collagen fiber arrayed in parallel, and nodular plaques were collagen fiber arrayed in a folding pattern. Ferruginous bodies could be seen among collagen fiber in the histological sections of pleural plaques. It suggests that corresponding amendement to the national diagnostic criteria for pneumoconiosis is necessary.

Aged↗
PubMed1997

[Tissue concentration and secretion of renin in human placental villi during early pregnancy].

In this study, tissue concentrations of renin and angiotensins in human placental villi during early pregnancy and contents of renin and angiotensin I (A I) secreted by cultured chorion were measured by radioimmunal assay (RIA). The results are as follows. During early pregnancy, the human chorion contains renin and A II. The activity of renin is much higher at 6th week of gestation, but as gestation proceeds, it decreases gradually, while A II shows somewhat increased change. The activity of renin secreted by cultured chorion can also be measured. A I in human placental villi can not be detected by RIA in chorion leaves or their culturing fluid. These results indicate that renin-angiotensin system may exist independently in human placental villi during early pregnancy.

Angiotensin I↗
PubMed1997

Basic fibroblast growth factor confers growth inhibition and mitogen-activated protein kinase activation in human breast cancer cells.

The effect of basic fibroblast growth factor (bFGF) on human breast cancer cells was studied in vitro. Exposure to bFGF resulted in significant growth inhibition, decreased DNA synthesis, and accumulation of cells in G0-G1. The IC50 for growth inhibition in MCF-7 cells was 50 pg/ml, and it was abrogated by neutralizing antibodies against bFGF. Inhibition of growth by bFGF was predominant over the growth stimulatory effects of 17beta-estradiol, insulin, or epidermal growth factor. Binding and cross-linking studies of 125I-labeled bFGF in intact MCF-7 cells demonstrated 5.2 x 10(3) saturable bFGF binding sites per cell, a dissociation constant of 57 pm, and a Mr 142,000 (125)I-labeled bFGF cross-linked protein. Stimulation of MCF-7 cells with bFGF at concentrations which effected growth inhibition also resulted in activation of p42(mapk) (ERK2) and p44(mapk) (ERK1) mitogen-activated protein kinases. These data demonstrate that whereas bFGF inhibits the growth of several breast cancer cell lines, it concomitantly activates ERK1 and ERK2, generally considered to signal mitogenic rather than growth inhibitory responses. Whether there is association between these phenomena remains unknown.

Binding Sites↗
PubMed1997

[Investigation on the viscoelastic properties of hepatocytes and their relavances to cytoskeleton structure].

Using micropipette aspiration technique, the authors investigated the viscoelastic properties of human fetal hepatocytes (HFH) and hepatocellular carcinoma (HCC) cells. And further, the effects of two cytoskeleton interferents, cytochalasin D and colchicine on the viscoelastic properties of HFHs were investigated. The results showed: the elastic coefficients K1 and K2 of HCC cells were significantly higher than those of HFHs; the action of cytochalasin D led to an obvious decrease in elastic coefficients K1, K2 as well as the viscous coefficient mu of HFHs; under the action of colchicine, the K1 value of HFHs increased while the K2 and mu values decreased obviously or tended to decrease. A brief discussion was presented about these results.

Carcinoma, Hepatocellular↗
PubMed1997

[A review of 3-D ultrasonic medicine imaging].

This paper introduces the present situation of research and methods of 3-D ultrasonic medicine imaging. An extensive summary of the clinical application of 3-D ultrasonic images is also presented. At last this paper discusses the factors influencing the quality of 3-D image reconstruction and some cynosure of research directions.

Echocardiography, Three-Dimensional↗
PubMed1997

[Design of noninvasive steel miniplate for tenodesis and its clinical application].

To fix the ligaments, tendons or other transplantation materials by passing through bone channels was commonly used and a relialde method in the reconstruction of joint stability. Usually an additional incision was necessary on the side of the outlet of the bone channel, that the screws, plates or U-shaped staple could be applied. An instrument was designed that the steel miniplate could be fixed to the bone by noninvasive method. This technique was applied in 20 cases in which anterior cruciate ligament in 14, posterior cruciate ligament in 4, and collateral ligaments in 2 with carbon fibers. The result was successful in all patients. It was shown that it gave simple manipulation, reliable fixation and no need to have an additional incision, and it could lessen patients' suffering and lead to satisfactory clinical result.

Adult↗
PubMed1997

[Study on culture and osteogenic potential of stromal cell of bone marrow in vitro].

The osteogenc potential of bone marrow has been proved by experiment. To investigate more in details, bone marrow was obtained from the trochanteric region of femur of New-Zealand rabbit in 4 to 8 weeks old. After being cultured in vitro for one week, the hematopoietic component of the bone marrow had disappeared, thus the stromal cells were obtained. Then the stromal cells were subcultured in cultural fluid containing dexamethasone (10(-8) mol/L) and natrium glycerophosphate (10 mmol/L). Under the phase-contrast microscope, it was found that being cultured for 15 days. The stromal cells were lined up in one layer and late the secretion activity was increased and gradually transformed into multilayer structure and was congregated into diffused opaque clusters in twenty days. During culture, the cells were examined by tetracycline fluorescence label, histochemistry stains, transmission electron microscopy, scanning electron microscopy and energy dispersive X-ray microanalysis. The results showed that the morphological and biological characteristics of the cultured stromal cells derived from the bone marrow were similiar to those of osteoblasts and could synthesized mineralized new bone tissue in vitro.

Animals↗
PubMed1996

Structure and analysis of the mouse Na+/H+ exchanger (NHE1) gene: homology and conservation of splice sites.

The Na+/H+ exchanger is a widely distributed integral membrane protein that is responsible for pH regulation in mammalian tissues. We have cloned and analyzed the NHE1 isoform of the mouse genomic Na+/H+ exchanger. A clone from a mouse genomic library contained the NHE1 promoter region and the 5'-untranslated region. It also contained the first 121 amino acids of the coding region of the Na+/H+ exchanger. A splice site occurred after amino acid 121, at the same region as in the human NHE1 gene. The deduced amino terminal coding sequence was 76 and 88% identical to the human and rat NHE1 sequences respectively. The 5'-untranslated region was highly homologous to that of other species and two minicistrons contained in the human Na+/H+ exchanger were present in the mouse sequence. The results show that the deduced protein sequence of the mouse NHE1 gene has a high level of homology with other species and that the splice site of the first intron is conserved. These results suggest that the first large intron may play an important role in the NHE1 gene expression.

Amino Acid Sequence↗