Biomedical subjects

J Han

Publications and source records attributed to J Han.

At least 199 records · Page 11Linked to original sources

PubMed1999

[The effect of thrombin on tissue factor activity in cultured bovine aortic endothelial cells and its correlation with PKC pathway].

OBJECTIVE: To study the stimulating effect of thrombin on the expression of tissue factor (TF) activity in cultured bovine aortic endothelial cells (BAEC) and to elucidate if it is associated with the PKC system. METHODS: The BAECs were cultured after the Schwartz's method and one stage clotting time assay was used to measure TF activity in BAEC lysates. The TF activity was identified by EDGR-VIIa and a monoclonal antibody against TF. RESULTS: Thrombin enhanced the expression of TF activity in cultured BAEC and the effect was dose- (r = 0.78, P < 0.05, n = 8) and time-dependent (r = 0.88, P < 0.05, n = 8). PMA, a PKC activator, also induced the expression of TF activity in BAEC. H7, a protein kinase C inhibitor, inhibited the inductive effects of PMA and thrombin on TF in BAEC. CONCLUSION: Thrombin can induce the expression of TF activity in cultured BAEC and the effect depends on PKC pathway.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed1999

DNA vaccine pCD-Sj32 and its efficacy of protective immunity against infection of Schistosoma japonicum.

OBJECTIVE: To study protective immunity afforded by murine immunization with DNA vaccine of Schistosoma japonicum (S. japonicum) as measured by reduction in worm burden and host antibody, cytokines. METHODS: DNA vaccine pCD-Sj32 was constructed, identified and expressed. pCD-Sj32 could induce substantial protective immunity against infection of S. japonicum in BALB/c mice. The best efficacy can be produced with one injection of 100 micrograms DNA into the quadriceps muscle, combined with challenge for 8 weeks after immunization. T lymphocyte subsets of CD8+, IL-2. TNF and IFN-gamma of experimental animal could play important roles in regulating immune functions of schistosomiasis. RESULTS: High titre of specific antibody IgG could be induced by vaccinated with pCD-Sj32, and antibody can mediate macrophage to produce ADCC effects in vitro. CONCLUSION: pCD-Sj32 may represent a new approach to developing subunit vaccine.

Animals↗

PubMed1999

Partial left ventriculectomy for the treatment of end-stage dilated cardiomyopathy.

OBJECTIVE: To report our initial experience of the first 5 cases of partial left ventriculectomy (PLV or Batista operation), a new surgical therapy for treatment of end-stage dilated cardiomyopathy in China. METHODS: From April to August 1998, 5 patients with idiopathic dilated cardiomyopathy received PLV at Anzhen Hospital. The mean age of the patients was 48.4 years (range: 42 to 53 years). Three patients were in New York Heart Association (NYHA) class III and 2 in class IV. All patients had mitral valve insufficiency (3 moderate and 2 severe) and 1 had severe tricuspid valve insufficiency in addition preoperatively. Cardiopulmonary bypass and cardiac arrest with cold blood cardioplegia were used in all patients. The average weight of the resected left ventricle muscle was 46.3 g. All patients underwent mitral annuloplasty and 1 plus tricuspid annuloplasty (De Vega). RESULTS: Echocardiography demonstrated a significant decrease in left ventricular diastolic diameter (8.4 +/- 1.1 cm to 5.4 +/- 0.4 cm, P < 0.01) and an increase in ejection fraction (17.78% +/- 6.26% to 34.82% +/- 3.18%, P < 0.025). One patient died of heart failure on the 6th postoperative day. The mean follow-up period of the 4 discharged patients were 4 months (from 3 to 6 months). One were in NYHA class I and 3 in class II; all had a normal life. CONCLUSION: Batista operation is a new and valuable alternative of the surgical treatment for end-stage dilated cardiomyopathy and the long-term results need further studies.

Adult↗

PubMed1999

[Effect of Panax notoginseng saponin on Ca2+, CaM in craniocerebral injury].

OBJECTIVE: To explore the change of nerve cell Ca(2+)-overload, Ca(2+)-CaM and the effect of Panax Notoginseng saponin (PNS) on it in craniocerebral injury. METHODS: Blood and brain contents of Ca2+, CaM were examined by radio-immunoassay (RIA) and atomic absorption spectrometry(AAS), and effect of PNS on these parameters was observed in craniocerebral injury rabbits. RESULTS: The levels of Ca2+ and CaM in blood and those in brain were significantly positively correlated. PNS could reduce Ca2+ and CaM contents in blood and in cerebral tissue. CONCLUSION: PNS could block the Ca(2+)-overload and Ca(2+)-CaM complex production in nerve cell after cranial cerebral injury, thereby to protect the injured brain in a certain degree. Blood CaM level is an objective index for assessment of Ca(2+)-overload in nerve cell.

Animals↗

PubMed1999

[Combined TIPSS with modified Sugiura operation for portal hypertension].

OBJECTIVE: To evaluate the clinical results of combined TIPSS with modified Sugiura operation for portal hypertension. METHODS: 24 patients with portal hypertension associated with variceal bleeding and ascites were treated with TIPSS and then modified Sugiura operation two weeks later. RESULTS: After combined TIPSS with modified Sugiura operation, variceal bleeding ceased and ascites subsided. The portal pressure significantly decreased (P < 0.01) and the portal blood flowed quickly (P < 0.01). The blood velocity of intrahepatic shunts was (132.64 +/- 41.42) cm/s. Direct portal venography showed that coronary vein had disappeared. No rebleeding was noted in varices and stenosis in intrahepatic shunts. CONCLUSIONS: Combined TIPSS with modified Sugiura operation not only can reduce portal pressure and improve portal circulation, but also completely interrupt coronary vein and maintain liver function.

Adult↗

PubMed1999

[Recovery of gastrointestinal motility following laparoscopic versus open cholecystectomy].

OBJECTIVE: To investigate the recovery of gastrointestinal motility after laparoscopic cholecystectomy (LC) and open cholecystectomy (OC). METHODS: Motilin (MOT), gastrin (GAS), electrogastrogram (EGG), the peristaltic sound recovery timing (PSRT) and the anorectum exhaust timing (AET) were determined in 30 patients having LC and 18 patients having OC. RESULTS: MOT, GAS, EGG frequency and EGG amplitude on the first, second and third day after operation in LC group were not significantly different in comparison with preoperative data (P > 0.05), but significant difference on the first and second postoperative day compared with preoperative data and data of the the LC group (P < 0.05). The PSRT and AET in the LC group were much shorter in comparison with the OC group (P < 0.05). CONCLUSIONS: The recovery of gastrointestinal motility after LC is earlier than OC, which justifies early feeding for patients after LC.

Cholecystectomy↗

PubMed1999

[Smoking, related cancers, and other diseases in shanghai: a 10-year prospective study].

OBJECTIVE: To explore the relationship between smoking and related diseases among residents of Shanghai. METHODS: A cross-sectional study on current smoking status among 213,800 residents aged 20 yr and over in Shanghai urban, suburb and rural areas was carried out during the early 1980s. The residents in the urban area were followed up for 12 years (1983 - 1994) and those in suburb and rural areas for 11 years (1984 - 1994). A Poisson regression model was used to estimate relative risks RRs of certain diseases for smoking adjusted for age with their 95% confidence intervals by sex and area among persons aged 40 yr and over at the beginning of the study. RESULTS: In the urban area, the RRs of death for smoking were 1.48 and 1.62 in males and females, respectively and for cancer death were 2.20 and 2.00. Statistically significant elevated RRs were seen for cancers of the lung and liver in both males and females and for cancers of the oesophagus, stomach, pancreas and bladder only in males. Significantly higher RRs were also observed for cerebrovascular disease, chronic bronchitis and emphysema, and pulmonary heart disease. RRs lower than in the urban area were found in the suburb and rural areas. The population attributable risks (%, PAR) for death due to smoking for males were estimated by area. PARs for death were 20.9, 18.9 and 16.3 in urban, suburb and rural areas, respectively. For all cancers, PARs were 40.0, 34.5 and 34.2 and for lung cancer were 71.7, 59.2 and 64.7. CONCLUSION: Smoking was associated with the mortality of some common cancers, chronic bronchitis, and emphysema, pulmonary heart, and cerebrovascular diseases.

China↗

PubMed1999

[Changes of TF and TFPI activities in patients with hypertension or coronary atherosclerotic heart disease].

OBJECT: To investigate the changes of tissue factor (TF) and tissue factor pathway inhibitor(TFPI) activities in patients with hypertension or coronary atherosclerotic heart (CAH) disease. METHODS: TF activity was measured by two-stage assay, and TFPI activity was detected according to Sandset's method. RESULTS: Plasma TF activity in both patients with hypertension and patients with CAH disease was higher than that of normal control(P < 0.05). CONCLUSION: Hypercoagulative state may be involved in the pathogenetic processes of hypertension and CAH diseases. TF and TFPI activities have the likelihood to become the accessory diagnostic indexes for hypertension and CAH diseases.

Adult↗

PubMed1999

[Studies on identification of yinchaihu by UV and IR].

OBJECTIVE: To study the identification of nine species of Yinchaihu derived from four genera of Caryophyllaceae, namely, Stellaria dichotoma var. lanceolata, St. dichotoma var. dichotoma, Arenaria juncea, A. capillaris var. glandulifera, Silene fortunei, Si. jenisseensis, Gypsophila pacifica, G. oldhamiana and G. licentiana. METHOD: UV and IR of alcohol extraction. RESULTS: The UV and IR spectra of these 9 plant roots have some difference. CONCLUSION: St. dichotoma var. lanceolata specified in the Chinese Pharmacopoeia can be distinguished from the other plants and all these 4 genera can be differentiated from one another by both UV and first derivative spectra. The genus Stellaria can be identified from the other 3 genera by IR.

Caryophyllaceae↗

PubMed1999

[Inhibitory Effects of Etoposide Combined with 8-methoxypsoral en on Highly Metastatic Human Mucoepidermoid Carcinoma Cells].

OBJECTIVE: To study the inhibitory effects of Etoposide (VP16) combined with 8-methoxypsoralen (8-MOP) on human highly metastatic mucoepidermoid carcinoma cells (Mc3). METHODS: Mc3 cells were exposed to the drugs and their combinations at various concentrations. The inhibitory effects were tested with microculture tetrazolium colorimetric assay (MTT assay) and cologenic assay. RESULTS: The IC50 values of VP16 and 8-MOP were 1625. 25 ng/ml and 750000 ng/ml respectively, the CI50 of the combination at 100320 and 1000 ng/ml of VP16 with 8-MOP were 0.350, 0.599 and 0.880 respectively. CONCLUSION: The data indicate that combination of VP16 and 8-MOP is synergic in the inhibition of Mc3 cell growth.

Carcinoma, Mucoepidermoid↗

PubMed1999

[Preliminary study of a new concept for left ventricular assistance dynamic aortic valve].

Dynamic aortic valve, a novel design for left ventricular assistance is proposed. An impeller similar to the airscrew is placed in the position of aortic valve. The impeller is held by a pair of bearings in the center of a cylindrical supporting cage which is located in the lumen of the aorta ascendens. The supporting cage is attached to the valve annulus by a sewing ring of textile cuff around the outside of the cage. A rotor is fitted into the cage and connected to the impeller with a common shaft. The cage supports the aortic wall, thus prevents the rotor from founching the wall and allows the rotor to rotate freely. A stator, functioning as that of the electric motor, is located outside the aortic wall. When actuated, the magnetic field generated by the stator would drive the rotor to turning, and the axial flow of blood from ventricular to the aorta would be produced, resulting in the reduction of the ventricular load. We studied this concept in a simulating model. The result suggests that this design be reasonable. Further exploration of this concept is justified.

Heart Valve Prosthesis↗

PubMed1999

[Solid-state fermentation with Penicillium sp. PT95 for carotenoid production].

A preliminary study on solid-state fermentation (SSF) with Penicillium sp PT95 for carotenoid production was performed. The results showed that the production of carotenoid in sclerotia of PT95 was more efficient in corn meal medium than in either wheat bran medium or cottonseed hull medium. Addition of nitrogen and carbon sources as well as vegetable oil to media was required for increasing the dry weight of sclerotia and carotenoid yield. Among several tested compounds for nitrogen and carbon sources, sodium nitrate and maltose were the best. Through orthogonal experiments, the optimum culture medium was obtained by supplement of NaNO3 3g, maltose 10 g, soybean oil 2.5 g to per liter of salt solution. Under the optimum culture conditions, the sclerotia dry weight increased from 5.36 g to 9.70 g per 100 g dry substrate, the carotenoid yield from 2149 micrograms to 5260 micrograms per 100 g dry substrate, the proportion of beta-carotene in carotenoids from 61.4% to 71.3%.

Carotenoids↗

PubMed1999

[A preliminary study of two Chinese herbs protective tablets on some Chinese traditional medicines].

The protective action of 2 tablets of Chinese herb to 5 Chinese traditional medicines against harm of insects and mildews was tested. It was found that 2 tablets have a obvious effects of insect-repellency and mouthproof in the test with Homalomena occulta and Prunus armeniaca, the bore in the medicinal materials was decreased 94.95% and 95.55% respectively than that of check. The tablets have some effects of mildewproof in the test with Tussilago farfara.

Alisma↗

PubMed1998

Interaction of E1B 19K with Bax is required to block Bax-induced loss of mitochondrial membrane potential and apoptosis.

The Bcl-2 homologous region 3 (BH3) is sufficient for interaction of pro-apoptotic with anti-apoptotic Bcl-2 family members, and functional antagonism may determine whether cell survival or death is the outcome of this protein-protein interaction. To address the biological role of BH3, two Bax-Bcl2 chimeras were generated in which 13 amino acids encompassing BH3 was swapped between anti-apoptotic Bcl-2 and pro-apoptotic Bax, thereby generating Bax with BH3 of Bcl-2 (Bax-BH3Bcl2), and Bcl-2 with BH3 of Bax (Bcl2-BH3Bax). Function and binding of the chimeras was then assessed utilizing the adenoviral Bcl-2 homologue, E1B 19K, which blocks apoptosis, and interacts with Bax, but not with Bcl-2. E1B 19K did not interact with Bax-BH3Bcl2 but did interact with Bcl2-BH3Bax. Bax-BH3Bcl2 retained pro-apoptotic function, while Bcl2-BH3Bax did not exhibit either pro- or anti-apoptotic activity. Thus, BH3 of Bcl-2 encodes binding specificity but not the apoptotic propensity. E1B 19K could not block Bax-BH3Bcl2-induced apoptosis, suggesting that E1B 19K may act to antagonize pro-apoptotic proteins rather than as an effector of survival. Furthermore, Bax expression disrupted the mitochondrial membrane potential, which could be rescued by E1B 19K expression. Thus, BH3 controls the binding specificity among Bcl-2 family members, and direct interaction between pro-apoptotic and anti-apoptotic proteins is a mechanism to regulate mitochondrial membrane potential and apoptosis.

Adenovirus E1B Proteins↗

PubMed1998

p38 Kinase is a negative regulator of angiotensin II signal transduction in vascular smooth muscle cells: effects on Na+/H+ exchange and ERK1/2.

Activation of the Na+/H+ exchanger isoform-1 (NHE-1) by angiotensin II is an early signal transduction event that may regulate vascular smooth muscle cell (VSMC) growth and migration. Many signal transduction events stimulated by angiotensin II are mediated by the mitogen-activated protein (MAP) kinases. To define their roles in angiotensin II-mediated NHE-1 activity, VSMCs were treated with angiotensin II and the activities of p38, c-Jun N-terminal kinase (JNK), and extracellular signal-regulated kinases 1 and 2 (ERK1/2) were measured. Angiotensin II rapidly (peak, 5 minutes) activated p38 and ERK1/2, whereas JNK was activated more slowly (peak, 30 minutes). Because angiotensin II stimulated Na+/H+ exchange within 5 minutes, the effects of p38 and ERK1/2 antagonists on Na+/H+ exchange were studied. The MEK-1 inhibitor PD98059 decreased ERK1/2 activity and Na+/H+ exchange stimulated by angiotensin II. In contrast, the specific p38 antagonist SKF-86002 increased Na+/H+ exchange. Two mechanisms were identified that may mediate the effects of p38 and SKF-86002 on angiotensin II-stimulated Na+/H+ exchange. First, angiotensin II activation of ERK1/2 was increased 1. 5- to 2.5-fold (depending on assay technique) in the presence of SKF-86002, demonstrating that p38 negatively regulates ERK1/2. Second, the ability of angiotensin II-stimulated MAP kinases to phosphorylate a glutathione S-transferase fusion protein containing amino acids 625 to 747 of NHE-1 in vitro was analyzed. The relative activities of endogenous immunoprecipitated p38, ERK1/2, and JNK were 1.0, 2.0, and 0.05 versus control, respectively suggesting that p38 and ERK1/2, but not JNK, may phosphorylate NHE-1 in VSMC. These data indicate important roles for p38 and ERK1/2 in angiotensin II-mediated regulation of the Na+/H+ exchanger in VSMC.

Angiotensin II↗

PubMed1998

PRAK, a novel protein kinase regulated by the p38 MAP kinase.

We have identified and cloned a novel serine/ threonine kinase, p38-regulated/activated protein kinase (PRAK). PRAK is a 471 amino acid protein with 20-30% sequence identity to the known MAP kinase-regulated protein kinases RSK1/2/3, MNK1/2 and MAPKAP-K2/3. PRAK was found to be expressed in all human tissues and cell lines examined. In HeLa cells, PRAK was activated in response to cellular stress and proinflammatory cytokines. PRAK activity was regulated by p38alpha and p38beta both in vitro and in vivo and Thr182 was shown to be the regulatory phosphorylation site. Activated PRAK in turn phosphorylated small heat shock protein 27 (HSP27) at the physiologically relevant sites. An in-gel kinase assay demonstrated that PRAK is a major stress-activated kinase that can phosphorylate small heat shock protein, suggesting a potential role for PRAK in mediating stress-induced HSP27 phosphorylation in vivo.

Amino Acid Sequence↗

PubMed1998

Molecular cloning and characterization of a human protein kinase that specifically activates c-Jun N-terminal kinase.

The c-Jun N-terminal kinases (JNKs), also called stress-activated protein kinases (SAPKs), belong to the mitogen-activated protein kinase (MAPK) gene super-family. Like all the MAPKs, JNKs are activated through dual phosphorylation of a theronine residue and a tyrosine residue by a dual specificity kinase such as JNKK1/MKK4/SEK1. Here, we report the molecular cloning and characterization of hJNKK2 alpha, a human homolog of the recently reported murine MKK7 alpha. hJNKK2 alpha belongs to the MAPK kinase gene family and is expressed in many adult tissues. It is nearly identical to a recently reported human JNKK2 at the kinase domain but with major differences in both amino- and carboxyl-terminal sequences, suggesting that hJNKK2 alpha may be an alternative spliced form of this kinase. Expression of hJNKK2 alpha, but not its related kinases JNKK1/MKK4/SEK1, MEK1, MKK3, or MKK6, leads to strong activation of JNK in several cell lines. No activation of ERK or p38 kinases was observed with this kinase. An in-vitro kinase assay demonstrated that JNK1 activation by hJNKK2 alpha requires phosphorylation of the theronine and tyrosine residues at positions 183 and 185 in JNK1. Furthermore, hJNKK2 alpha activated the JNK-dependent signal transduction pathway in vivo by induction of c-Jun- and ATF2-mediated gene transcription. In conclusion, we have cloned the human homolog of murine MKK7 alpha, which may be an alternative spliced form of human JNKK2 involved in transducing specific upstream signals to regulate JNK activity in vivo.

Adult↗

PubMed1998

Cellular activation mechanisms in septic shock.

Septic shock is an increasingly important clinical condition, characterized by systemic hypotension, ischemia, and ultimately organ failure. In Gram negative infection, the bacterial cell wall component, lipopolysaccharide (endotoxin, LPS), has been strongly linked to the pathophysiological responses that result in septic shock. LPS is bound in plasma to a protein called LPS-binding protein (LBP), which facilitates the binding of LPS to a cell surface receptor, CD14. Binding to CD14 stimulates cell signaling mechanisms that result in the production of inflammatory cytokines. However, the events which follow LPS binding to CD14 and which lead to the production of cytokines remain unclear. It has recently become evident that a number of phosphorylation cascades including MAP kinase pathways and NF-kappaB activation pathway are initiated by exposure of cells to LPS. These cascades act at both the transcriptional and translational levels to regulate cytokine production. This review will focus on the signaling pathways that are initiated by LPS and the cellular effects of the signaling pathways.

Gram-Negative Bacterial Infections↗