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Biomedical subjects

Y Song

Publications and source records attributed to Y Song.

At least 235 records · Page 13Linked to original sources
PubMed1999

[Treatment of complex crainocervical junction malformation by transoccipito-cervical posterolateral approach].

OBJECTIVE: To report the treatment of six patients suffering from complex craniocervical junction (CCJ) malformation by transoccipitocervical posterolateral approach which is a new surgical method. METHODS: Transoccipitocervical posterolateral approach was confirmed feasible by anatomy of the body. Diagnosis was made sure CT-three dimensional image and MRI for every patient. All cases reaived odontoidectomy and suboccipital decompression and/or bone graft. RESULTS: All patients showed favorable outcome without deterioration or recurrence. Six patients were followed up for 15 - 10 months. All patients showed marked progressive improvement of neurological disturbances and three of them resumed work half a year after operation. CONCLUSION: Transoccipitocervical posterolateral approach is a new surgical procedure by which anterior and posterior decompression of foramen magnun aria and bone graft (posterior craniocervical stabilization) could be fulfilled during one operation.

Adult↗
PubMed1999

[Early results of 1,110 cases of coronary artery bypass].

OBJECTIVE: To introduce our experience with Coronary artery bypass. METHODS: From January 1996 to March 1999, coronary artery bypass was in 1110 patients at our hospital. They were 985 men and 125 women, aged 27 - 78 years (57 +/- 9). 500 patients were aged over 60 years. 670 patients had a history of myocardial infarction. 450 patients suffered from instable, and 460 from stable angina. 169 patients had stenosis of the left main trunk (>or= 50%). The heart function of 240 patients was over NYHA class III, the EF of 123 patients was less than 40%. 454 patients were associated with hypertension, 133 with diabetes, 131 with ventricular aneurysm, 48 with valvular disease, and 5 with rupture of ventricular septal. 1048 procedures were performed on hypothermia cardiopulmonary bypass (CPB) and 60 on beating heart. Myocardial preservation was carried out by cold blood cardioplegia with potassium. The average time of CPB was 115 +/- 35 minutes, and that of aortic cross clamp was 72 +/- 24 minutes 110 cases received one graft, 145 cases two grafts, 415 cases three grafts, and 439 cases four and more than four grafts. Left internal mammary artery, great saphenous vein, and radial artery were used as coronary artery bypass conduits on 751, 877 and 101 patients, respectively. Total arterial myocardial revascularization was performed on 72 patients. Concomitant operation included ventricular aneurysmetomy (112 cases), plication (14), left ventriculoplasty (5), valvular procedures (48), repair ventricular septal rupture (5). RESULTS: 1 101 patients were discharged uneventfully. Early death occurred in 9 patients, (0.81%). Complication included low cardiac output (11 cases), introaortic balloon pump (7), perioperative myocardial infarction (2), complication of brain (3), and rethoractomy for bleeding (4). CONCLUSIONS: To identify adequate target vessel and completely revascularize ischemic myocardium are the key of coronary artery bypass. Perioperative treatment is important.

Adult↗
PubMed1999

[The amyloidosis in cardiac conduction system].

OBJECTIVE: To investigate the relationship between arrhythmia, cardiac failure and amyloidosis of cardiac conduction system (CCS). METHODS: CCS from 6 cases with cardiac amyloidosis were sampled using technique designed by the authors. The CCS were studied by Congo red staining and polarization microscopy. RESULTS: Pathological changes could be found in the CCS of these 6 cases. It was serious in sino-atrial node while slight in atrio-ventricular conduction system. The changes in atrio-ventricular conduction system were exacerbated from proximal part (atrio-ventricular node) to distal part (left bundle branch). In the 3 cases with sinus bradycardia and conduction blocking manifested by electrocardiogram, the pathological changes in CCS were more extensive and serious than that of other cases. CONCLUSION: The amyloidosis in CCS is one of the pathological bases of arrhythmia.

Aged↗
PubMed1999

[The analysis of pathological changes of cardiac conduction system in 54 cases of cardiac sudden deaths].

OBJECTIVE: To elucidate the exact cause of death in cases of cardiac sudden deaths. METHODS: Sampling of cardiac conduction system (CCS) designed by the research group was adopted. The CCS of 120 cases died of cardiac sudden deaths were collected for routine histological examination. RESULTS: In 54 out of 120 cases, the causes of death were attributed to lesions present in the CCS, and 85.2% of them were young adults. The peak age range was from 20 - 30. Much more in males (6.7:1). The pathological changes in CCS include: inflammation (46.2%), fatty infiltration, hypertrophic cardiomyopathy associated with CCS changes; hemorrhage, developmental anomalies, fibrosis and tumors. CONCLUSION: The pathological changes of CCS are relatively common, as the cause of sudden deaths. Which is considered to be the pathological basis of the unstable cardiac electric potentials and arrhythmia. This study recommended the necessity of routine examination on CCS in cases of sudden deaths.

Adult↗
PubMed1999

[Changes of telomere length in human nasopharyngeal carcinoma].

Using Southern hybridization, we analysed the telomere length from thirty patients with nasopharyngeal carcinoma and demonstrated telomere reduction in these individuals when compared with their age-matched controls. Of the 30 samples, 16.67% had telomere elongation, 76.67% had telomere reduction and 6.67% exhibited equal lengths as compared with the controls. Analysis of leukocytes from 30 controls indicated that the telomere length decreased (average 39 base Pairs Per year) with aging and a statistically significant correlation between the length and age was noted (r = -0.3913, P < 0.05). These results suggest that the consequences of telomere shortening in nasopharyngeal carcinoma may lead to chromosome instability.

Adult↗
PubMed1999

[Quantitative determination of vanillic acid in rhizoma Picrorhizae by TLC-scanning].

OBJECTIVE: To establish a method to determine the content of vanillic acid in Rhizoma Picrorhizae. METHOD: The content was determined by dual wavelength TLC-scanning. RESULT: The peak area of vanillic acid is reproducible in 4 hours; recovery 96.5%; RSD-3%; RSD of duplicate experiment-5%. CONCLUSION: A thin-layer chromatographic scanning method has been developed for determining the content of vanillic acid. The method is reproducible, workable and reliable.

Chromatography, Thin Layer↗
PubMed1999

[Synthesis and distribution of type IV collagen in mice testes].

OBJECTIVE: The variations of the synthesis and distribution type IV collagen in the testes of young, adult, and old mice were studied. METHODS: Biotin-avidin DCS system indirect immunofluorescence technique and in situ hybridization method were used. RESULTS: Sertoli cell could synthesize type IV collagen. Type IV collagen was present in the basement membrane of seminiferous tubules in mouse testis. Type IV collagen mRNA signal was seen in the Sertoli cells. The content of type IV collagen and type IV collagen mRNA peaked at day 15, and then declined successively to adult value and the aged value. CONCLUSIONS: The results suggest that the extracellular matrix of testis might play an important role in the process of spermatogenesis.

Age Factors↗
PubMed1999

[Research on applications of micromachine technology in medical engineering].

This paper presents the basic concept of micromachines. The development aim and Key technology of medical micromachine Research are discussed here too. Besides, this Paper introduces some typical application research of micromachines, which may have actual reference Value for the future development of medical engineering.

Artificial Organs↗
PubMed1999

[Study of dental model testing tool based on robot theory].

A new three dimensional testing and analysing system of dental model is discussed It is designed based on the motion theory of robots. The system is capable of not only measuring the three dimensional sizes of dental models, but also saving and outputing the tested data. The construction of the system is briefly introduced here.

Equipment Design↗
PubMed1999

[The reconstruction of laryngeal function in subtotal laryngectomy with preservation of arytenoid cartilage].

OBJECTIVE: To evaluate subtotal laryngectomy with preservation of arytenoid cartilage to reconstruct laryngeal function in T3 glottic or supraglottic laryngeal cancer. METHODS: Subtotal laryngectomy with preservation of arytenoid cartilage to reconstruct laryngeal function was reviewed in 20 patients with T3 laryngeal cancer(3 cases with glottic cancer and 17 cases with supraglottic cancer). Recurrent laryngeal nerve was preserved during surgery. The mucous membranes between cricoid cartilage and pharynx were sewed up accordingly. RESULTS: All patients had restored phonation and swallowing functions. The 3- and 5-year survival rates were 94.1% and 91.8% respectively. Decannulation rate was 95.0%. CONCLUSION: Subtotal laryngectomy with preservation of arytenoid cartilage is recommended for T3 laryngeal cancer.

Aged↗
PubMed1999

[SERS of bilirubin and its complexes].

SERS spectra of bilirubin and its complexes were determined in Ag sol by the technique of the connection between NIR-FT-Raman and SERS. The spectra showed that this kind of biological complexes, which is closely related to gallstones, differ in coordination pattens and adsorptive orientation as well. The reason why the black-pigment gallstone exhibits that peculiar dark color was also given from the coordination-chemistry point of view.

Bilirubin↗
PubMed1998

A trypsin-like platelet protease propagates protease-activated receptor-1 cleavage and platelet activation.

Protease-activated receptor-1 (PAR-1) is a G-protein-linked receptor on platelets and perivascular cells activated by alpha-thrombin and the PAR-1-activating peptide, SFLLRN. alpha-Thrombin activates PAR-1 by cleaving it at R41-S42 to release the 41-residue peptide TR(1-41). Unexpectedly, platelet activation with SFLLRN was also associated with PAR-1 cleavage and the release of TR(1-41). Both PAR-1 cleavage and platelet activation resulting from SFLLRN addition to platelets were markedly inhibited by the serine protease inhibitor 4, 2-(aminoethyl)-benzene sulphonylfluoride.HCl (pefabloc SC) and soybean trypsin inhibitor, but not by inhibitors of calpain, cysteine proteases or metalloproteases. Thus, a trypsin-like platelet protease propagates SFLLRN-dependent PAR-1 cleavage and platelet activation.

Collagen↗
PubMed1998

Evidence for an Alzheimer disease susceptibility locus on chromosome 12 and for further locus heterogeneity.

CONTEXT: Alzheimer disease (AD) susceptibility genes have been identified on chromosomes 1, 14, 19, and 21, and a recent study has suggested a locus on chromosome 12. OBJECTIVE: To confirm or refute the existence of a familial AD susceptibility locus on chromosome 12 in an independent sample of familial AD cases. DESIGN: Retrospective cohort study. DNA data for 6 chromosome 12 genetic markers were evaluated using parametric lod score and nonparametric linkage methods and linkage heterogeneity tests. The latter include the admixture test of homogeneity in the total group of families and the predivided sample test in families stratified by the presence or absence of an apolipoprotein E (APOE) epsilon4 allele among affected members. Parametric analyses were repeated assuming autosomal dominant inheritance of AD and either age- and sex-dependent penetrance or zero penetrance for the analysis of unaffected relatives. SETTING: Clinical populations in the continental United States, Canada, Argentina, and Italy. PATIENTS: Fifty-three white families composed of multiple members affected with AD, from whom DNA samples were obtained from 173 patients with AD whose conditions were diagnosed using established criteria and from 146 nondemented relatives. MAIN OUTCOME MEASURE: Presence of an APOE epsilon4 allele among affected family members. RESULTS: Using parametric methods, no evidence for linkage to the region spanned by the chromosome 12 markers could be detected if familial AD is assumed to arise from the same genetic locus in all 53 families. However, significant evidence for linkage was detected in the presence of locus heterogeneity using the admixture test (odds ratio, 15, 135:1). The estimated proportion of linked families within the 53 families examined varied between 0.40 and 0.65, depending on the genetic model assumed and APOE status. The precise location of the AD gene could not be determined, but includes the entire region suggested previously. Nonparametric linkage analysis confirmed linkage to chromosome 12 with the strongest evidence at D12S96 (P<.001). CONCLUSIONS: Our data provide independent confirmation of the existence of an AD susceptibility locus on chromosome 12 and suggest the existence of AD susceptibility genes on other chromosomes. Screening a larger set of families with additional chromosome markers will be necessary for identifying the chromosome 12 AD gene.

Adult↗
PubMed1998

The immunostimulatory effect of bio-active peptide from pollen on murine and human lymphocytes.

The effects of bio-active peptide (BP) from buckwheat pollen and its synthetic analogues on murine and human lymphocytes and HL-60 cells were examined. Both natural and synthetic BP had the same effect in the lymphocyte blast transformation test. The proliferative response of HL-60 cells, co-cultured for 72 h with BP, was measured by the MTT method. BP had a stimulatory effect on HL-60 cell proliferation. The optical density (OD) value was 0.339+/-0.015, whereas, that of the control without BP was significantly lower (0.279+/-0.037; P < 0.05). The CD25 (IL-2Ralpha chain) positive cells of BP-stimulated human lymphocytes assessed by indirect immunofluorescence were 53.97+/-7.12% (1 microg/ml) and 42.53+/-4.4% (10 microg/ml), significantly higher than the control (11.77+/-1.88%; P < 0.001). The content of sIL-2R in the supernatant after culture with BP was determined by ELISA and was 1782.3+/-78.18 U/ml, lower than control 2381.2+/-99.9 U/ml. Taken together, our results showed that BP has an immunostimulatory effect on lymphocytes. The likely mode of BP action and the possibility of developing a novel immunomodulator are discussed.

Adjuvants, Immunologic↗
PubMed1998

Estrogen receptor transactivation in MCF-7 breast cancer cells by melatonin and growth factors.

The pineal hormone, melatonin, inhibits proliferation of estrogen receptor (ER)-positive MCF-7 human breast cancer cells, modulates both ER mRNA and protein expression, and appears to be serum dependent, indicating interaction between melatonin and serum components. To examine the effects of melatonin on ER activity, ER transactivation assays were performed by transiently transfecting MCF-7 cells with an ERE-luciferase reporter construct. MCF-7 cells pre-treated with melatonin for as little as 5 min followed by either epidermal growth factor (EGF) or insulin resulted in the estrogen-independent transactivation of the ER. None of the compounds when used alone transactivated the ER. The ability of melatonin and EGF to transactivate the ER was abolished by the addition of the antiestrogen, ICI 164384, suggesting that melatonin and EGF co-operate to transactivate the ER. The modulation of ER transactivation was associated with changes in mitogen activated protein kinase activity and ER phosphorylation. This ER transactivation was blocked by pertussis toxin, a Galpha i-protein-coupled receptor inhibitor, suggesting cross talk between the G-protein-coupled melatonin receptor pathway and the EGF/insulin tyrosine kinase receptor pathways in modulating ER transactivation. Exactly how the ability of melatonin in combination with EGF to transactivate the ER relates to melatonin's observed growth suppressive effects is not clear. It is possible that, although melatonin and EGF transactivate the ER, this transactivation does not result in the full transcription of estrogen-responsive genes, but rather, makes the ER refractory to activation by estradiol, thus, blocking the mitogenic actions of estradiol.

Blotting, Western↗
PubMed1998

Interaction of monomeric and dimeric kinesin with microtubules.

The binding stoichiometry of kinesin to microtubules was determined using several biochemical and biophysical approaches (chemical crosslinking, binding assays, scanning transmission electron microscopy (STEM), image reconstruction, and X-ray scattering). The results show that each tubulin dimer associates with one kinesin head, irrespective of whether kinesin occurs in a monomeric or dimeric form in solution. Moreover, these heads appear to align along the protofilament axis generating a 16 nm periodicity of successive kinesin dimers. This is consistent with a "tightrope" model of movement where the first head of the dimer provides a guiding signal for the following one.

Animals↗