Biomedical subjects

Yang Hua

Publications and source records attributed to Yang Hua.

13 recordsLinked to original sources

PubMed2006

The feature of papers and citation analysis of eleven journals in tropical medicine indexed by Science Citation Index Expanded.

To determine the features of papers, authors, and citation of eleven journals in tropical medicine indexed by Science Citation Index Expanded, the database of the Institute for Scientific Information, we analyzed original articles, editorials, reviews, corrections, letters, biographies, and news published in these journals. The results show that these journals covered 107 countries or regions on six continents. The average number of reference was 23.05, with 87.89% of the references from periodicals. The Price Index was 31.43% and the self-citing rate was 7.02%. The references in the first 20 journals ranked by the amount of citation accounted for 36.71% of the total citations. Brazil, United States, India, and England are more advanced in tropical medicine research. The conclusion is that these journals covered most research done in these countries or regions. Most researches were done by cooperation of the researchers, but many of the publications used outdated articles and should include newer information.

Bibliometrics↗

PubMed2005

Primary study on imaging in transient ischemic attacks.

BACKGROUND: Although transient ischemic attacks (TIA) is a clinical diagnosis, imaging findings are important for its diagnosis and treatment. This study evaluated the value and limitations of conventional CT, CT cerebral perfusion imaging and transcranial Doppler sonography (TCD) in patients with TIA. METHODS: Conventional CT, CT cerebral perfusion imaging and TCD were performed in 20 patients with TIA. After regular CT examination, 40-second dynamic scans were performed on selected slice, while 40 ml of non-ionic contrast materials was bolus-injected through antecubital vein with power injector. These dynamic images were processed with the perfusion software package on workstation. Cerebral blood flow (CBF) and time to peak (TTP) were measured in specific regions of the brain. TCD was also performed in 20 patients with TIA. Comparative analysis was made on the basis of the results of conventional CT, CT cerebral perfusion imaging and TCD. RESULTS: In the 20 patients with TIA, conventional CT turned out to be normal. However, persisting abnormal perfusion changes corresponding to clinical symptoms were found in 13 cases with the prolonged TTP. The other 7 cases were normal. TTP of the affected side (11.6 +/- 3.0) s was significantly prolonged (t = 4.782, P < 0.01) in comparison with the contralateral side (8.8 +/- 1.5) s. The difference in CBF was not statistically significant (t = 1.912, P = 0.073) between the affected side [(223.9 +/- 19.6) ml.min(-1).L(-1)] and the contralateral side [(227.7 +/- 19.8) ml.min(-1).L(-1)]. TCD revealed severe stenosis or occlusion of the carotid artery in 10 patients, arteriosclerosis in 6 patients, blood speed decrease in 2 patients, vasospasm in 1 patient. CONCLUSIONS: Conventional CT can exclude intracerebral diseases. Perfusion CT provides valuable hemodynamic information and shows the extent of perfusion disturbances. TCD can demonstrate abnormalities of the involved arteries in patients with TIA. The combination of these three imaging methods can provide more diagnostic information.

Adult↗

PubMed2005

[Isolation and analysis of isolation of differentially-methylated fragment CIDM7 in rice induced by cold stress].

By using restriction enzyme isoschizomers that differ in their sensitivity to methylation of their recognition sites, AFLP analysis is carried out to analyse differences of the methylation state of anonymous CCGG sequences between cold-treated(5 degrees for 2 d) and control 9311(Oryza sativa L.) leaves DNA. Demethylation or De novo methylation induced by cold stress are found in some CCGG sites. Some differentially-methylated encoding sequences are isolated, of which a fragment named CIDM7 (cold-inducing differential methylation) is sequenced and executed BLAST against Nipponbare cDNA data, thus we obtain its full length cDNA of 1422 bp encoding a hypothetical F-box protein(425 aa).CIDM7 is demethylated induced by cold stress. Northern blot analysis confirms that CIDM7 gene expression is up-regulated by cold stress. CIDM7 is single copy and lacated on the Nipponbare chromosome 10 (12.56 Mb-12.57 Mb).

Amino Acid Sequence↗

PubMed2004

[Percutaneous transluminal stenting for stenosis of internal carotid artery: a report of 355 cases].

OBJECTIVE: To discuss the benefits and complications of percutaneous transluminal stenting for stenosis of internal carotid artery (ICA). METHODS: 355 patients with ICA stenosis were included from 1997 to 2003. All of them took periprocedual anticoagulation treatment, cerebral vascular angiography and cervical Doppler sonography. 72 patients used cerebral protection of filter devices. Among the 283 patients without cerebral protection 202 patients (71.38%) underwent predilation, 66 patients (23.32%) underwent postdilation; and 3 patients underwent neither. RESULTS: The heart rates of 25.0% of all the patients decreased. Dislocation of microemboli happened in 5 patients. 2 of them improved after treatment. 3 of them got dyskinesia of one side. 2 patients (0.56%) died of intracerebral hemorrhage (ICH). 256 patients (84.77%) turned for the better. 260 patients (73.34%) were followed up. Restenosis occurred in 11 patients (4.23%). CONCLUSION: Percutaneous transluminal stenting for stenosis of internal carotid artery is safe if proper periprocedual treatment and operative procedure are taken. However, enough attention should be paid to the occurrence of ICH resulting from over-flow after operation.

Adult↗

PubMed2004

Molecular cloning and expression analysis of rice phosphoribulokinase gene that is regulated by environmental stresses.

Phosphoribulokinase (PRKase, EC 2.7.1.19) plays an important role in regulating the flow of sugar through the Calvin cycle. To investigate its regulatory character and expression pattern, the gene encoding PRKase in rice was cloned by RACE. A full-length cDNA with an open reading frame of 1212 bp encoding 403 amino acids residues was obtained from an indica rice variety, 9311. The OsPrk is a single locus gene in the rice genome. It is localized in the region of 28.32 approximately 28.33 Mb on the Chromosome 2, flanked by the genetic markers RM450 and MRG0168. RT-PCR analysis revealed that OsPrk gene was expressed in all the tissues we tested and OsPrk transcript level could be dramatically boosted by light illumination. Its expression was down-regulated by externally applied NaCl, ABA, MeJA and glucose over 24 hr, whereas it was up-regulated by GA after 24 hr treatments. These results also indicated that OsPrk gene expression is modulated by these factors at multiple levels.

Amino Acid Sequence↗

PubMed2004

[Studies on evaluation of brain death].

OBJECTIVE: To investigate the methods of evaluating brain death accurately and objectively. METHODS: Various kinds of clinical examination [including conscious state, Glasgow coma score (GCS), brain stem reflection, cranial nerve dominated actions, spinal reflection, spinal nerve dominated automatic action, respiratory and apnea testing] and laboratory methods [such as electroencephalography (EEG), brainstem auditory evoked potentral (BAEP), brainstem auditory sensery evoked potentral (SLSEP) and transeranial Doppler (TCD)] were used to evaluate 11 cases with brain death. RESULTS: Eleven cases presenting with deep coma were conssedered to have brain death. All of them had GCS score of 3 and disappearance of brain stem reflection and cranial nerve dominated automatic action. Six of them patients showed anisocoria. Nine of them pharyngeal reflex could not be detected because of tracheal cannulization, but this did not influence the evaluation of brain death. None of them showed "flat" EEG and disappearience of BAEP dominant wave. None of the SLSEP show any wave behind N13. TCD showed blood stream characteristic of brain death except in one case blood stream characteristic of increased intracraniai pressure. Apnea test and atropine test provided the final proof brain death. The former had more influence on heart rate, blood pressure and oxygen saturation while the latter were more safe and reliable. CONCLUSION: Combined and continuous observation of clinical and laboratory indices can enhance the accuracy of the evaluation of brain death.

Adult↗

PubMed2003

[Complications of stent-assistant angioplasty of symptomatic intracranial artery stenosis].

OBJECTIVE: To discuss the safety of intracranial stenting for refractory symptomatic intracranial artery stenosis. METHODS: Forty-eight patients with symptomatic intracranial artery stenosis were treated by transluminal stent-assistant angioplasty. Of them, 40 cases were selected because they had recurrent TIAs or mild stroke despite of antiplatelet or anticoagulation therapy; 8 cases with high-grade stenosis after acute cerebral artery theromblysis. Lesions involved MCA (17/48); Basilar artery (8/48); intracranial vertebral artery (18/18); and distal ICA (5/18). RESULTS: For 46 of 48 cases the flexible coronary stent were successfully deployed. The average stenosis reduced from 83% to 5%, short-term follow-up showed good clinical improvement. Complications include vessel rupture (1/18); acute thrombosis within stent (1/48); perforation of cortical artery (1/18) and perforate vessel occlusion (1/18). CONCLUSION: Stent-assistant angioplasty are effective for treatment of symptomatic intracranial stenosis, the higher rate of complications may be because of the limited experiences of this technique. it need further practise and long term follow-up study.

Adult↗

PubMed2003

[Combined intraarterial thrombolysis and intra-cerebral stent for acute ischemic stroke institute of brain vascular diseases].

OBJECTIVE: To test feasibility, safety and efficacy of combined intraarterial thrombolysis and intra-cerebral stent for acute ischemic stroke. METHODS: From 2001-5 to 2002-8, 19 patients with acute onset of stroke were treated with intraaterial thrombolysis followed by intra-cerebral stent. 9 located in middle cerebral artery (MCA), 10 located in basal artery (BA). For each patient, intraarterial thrombolysis of MCA or BA was applied at first, stent angioplasty was applied at the stenosis left after the thrombolysis by using the stent for coronary artery. RESULTS: All the 19 patients left stenosis after intraaterial thrombolysis, and the average stenosis was 85% in diameter. After the operation of stent, the images showed the vascular is smooth and had no stenosis left. The symptoms were disappeared or improved. Thrombus formation in the stent occurred on 1 patient 24 hours after the operation. TIA never occurred in the left 18 patients then. TCD follow up showed blood flow is normal. CONCLUSIONS: It is feasibility of intraaterial thrombosis followed by intra-cerebral stent. And it is valid for preventing occlusion again of the vessel and decreasing the rate of TIA occurring.

Acute Disease↗

PubMed2002

Lysophosphatidylcholine alters enterocyte monolayer permeability via a protein kinase C/Ca2+ mechanism.

The activity of phospholipase A(2) (PLA(2)) is elevated in the intestinal epithelia of patients with inflammatory bowel disease. We recently reported that PLA(2) mediates the hydrolysis of phosphatidylcholine (PC) to lysophosphatidylcholine (L-PC) when both are applied to the apical surface of cultures enterocyte monolayers, resulting in increased bacterial translocation (BT) and decreased transepithelial electrical resistance (TEER). However, the mechanism by which the converted L-PC affects tight-junction permeability (TJP) as reflected by decreased TEER is unknown. There are some reports that protein kinase C (PKC) or Ca(2+) mediate TJP in enterocyte monolayer models. To investigate whether the observed change in TJP was mediated via PKC or Ca(2+) in our Caco-2 monolayer model, human Caco-2 enterocytes were grown to confluence on porous filters in the apical chamber of a two-chamber cell culture system. The filters were then transferred to an Ussing chamber for precise, real-time resistance measurements. After 30 min equilibration, PC (0.1 or 1 mM) and L-PC (0.01, 0.1 or 1 mM), PMA 200 or 300 nM (phorbol 12-myristate 13-acetate, PCK activator), or staurosporine 12 nM (PKC inhibitor) were added to the apical chamber and TEER was measured every 20 s for 2 h. The concentration of intracellular free Ca(2+) in the monolayers before and after treatment with L-PC (1 mM) was measured by fluorometry of whole monolayers using the fluorescent calcium indicator fura-2. Neither PC at any dose nor the 0.01-mM L-PC dose had an effect on TEER. The 0.1-mM dose of L-PC had its greatest effect (47% +/- 3.5% reduction in TEER vs control) within 6 min following its addition, with TEER recovery to control levels (100%) at 2 h ( P < 0.05). The 1-mM dose of L-PC had its greatest effect (6% +/- 0.5% reduction in TEER vs control) within 3 min after its addition, but the TEER did not recover to control levels after 2 h of incubation ( P < 0.05). The addition of 200 or 300 nM PMA inhibited the observed recovery of TEER by L-PC. Conversely, the addition of 12 nM staurosporine enhanced TEER recovery to control levels. The 1-mM dose of L-PC increased the concentration of intracellular free Ca(2+) immediately after the addition of L-PC. These results suggest that L-PC alters TJP via a PKC/Ca(2+) interaction in our Caco-2 monolayer model.

Caco-2 Cells↗

PubMed2002

[Quantitative assessment of Parkinsonian rigidity by vessel Doppler ultrasonography].

OBJECTIVE: To investigate the value of quantitative assessment of parkinsonian rigidity by vessel Doppler ultrasonography. METHODS: The diameter of the rigid limbs, including radial artery and vein, ulnar artery and vein, brachial veins, popliteal vein, anterior tibial vein, and posterior tibial vein in twelve individuals with PD and twelve age matched controls were measured by ultrasonography in both "on" and "off" states. Meanwhile the UPDRS unified Parkinson's disease rating scale for rigidity were also recorded both in "on" and "off " states by experienced neurologists. RESULTS: The mean diameter of radial vein, ulnar vein, brachial vein, popliteal vein, anterior tibial vein and posterior tibial vein, were 1.14, 1.13, 2.47, 3.85, 1.89, and 1.33 mm respectively in "off " state (group "A"), and were 1.58, 1.54, 2.88, 4.65, 2.27, and 1.69 mm respectively in "on" states (group "B") among the PD patients. The diameters of corresponding vessels in the controls (group "C") were 2.07, 1.69, 4.15, 5.07, 2.63, and 1.99 mm respectively. The data increased from group "A" to "C" gradually. Paired samples t tested showed a significant difference between the data of group A and group B (P = 0.00 approximately 0.03) and between group A and group C (P = 0.00 approximately 0.02) and no significant difference between group B and group C (P > 0.05, except for brachial vein with P = 0.02). The data of vein diameters in rigid limbs were correspondent to the UPDRS scores for rigidity with the correlation coefficient of 0.71, 0.82, 0.91, 0.73 (all P < 0.01), 0.60 P < 0.05 , and 0.77 P < 0.01) for the above mentioned vessels respectively. CONCLUSION: The diameter of distant veins in limbs can be adopted as objective and quantitative indicators for parkinsonian rigidity and contribute to the evaluation of therapeutical effects.

Aged↗

PubMed2002

[Stent-assisted angioplasty in treatment of symptomatic intracranial artery stenosis].

OBJECTIVE: To investigate the indications, safety and effectiveness of intracranial deployment of stents in treatment of systematic intracranial artery stenosis. METHODS: Stent-assisted angioplasty was performed upon 7 consecutive patients with symptoms of intracranial artery stenosis unresponsive to anticoagulant therapy and antiplatelet therapy. The lesions involved the middle cerebral artery in 3 cases, distal end of internal carotid artery in one case, basilar artery in one case, and intracranial section of vertebral artery in 2 cases. Short-term clinical and angiographic data were obtained. RESULTS: Symptoms of procedure-related intracranial hemorrhage and intracranial haematoma developed later were found in one patient. Emergency craniotomy was performed 5 hours after the stenosis-assisted angioplasty. The remaining patients experienced alleviation of symptoms without transient ischemic attack and apoplexy during the short-term follow-up. Angiography showed that the stenosis degree reduced from 83% to 5%. 0 - 3 months of follow-up by transcranial Doppler showed good patency of stented lesions. CONCLUSION: Stent-assisted angioplasty effectively treats atherosclerotic intracranial stenosis lesions. Long-term follow-up and further clinical/technical research are still needed.

Adult↗

PubMed2002

[Experience with transluminal stent-assisted angioplasty for intracranial vascular diseases].

OBJECTIVE: To assess the value of stent-assistant angioplasty for intracranial vascular diseases. METHODS: Thirteen patients with intracranial vascular diseases were treated consecutively by stent-assistant angioplasty for different purposes. Of these patients 7 had symptomatic intracranial artery stenosis, 3 intracranial wide-neck aneurysms, 2 intracranial pseudoaneurysms, and 1 bilateral transverse sinus stenosis. Clinical procedures and technical data of the patients were retrospectively analyzed. RESULTS: In the 7 patients, the degree of intracranial artery stenosis reduced from 83% to 5%. Three months after the operation they exhibited good patency of stented lesions. Intracranial wide neck aneurysms (with 2 pseudoaneurysms) were successfully embolized with GDC in 5 patients. The patients with bilateral transverse sinus stenosis were implanted a self-expanded stent in the right transverse sinus. One patient failed because of the tortuous configuration of the left jugular bulb, but the patient's symptoms were improved quickly after the procedure. CONCLUSION: Stent-assistant angioplasty is a useful technique for selected intracranial vascular diseases, and it needs further investigation.

Adult↗

PubMed2002

Experience of minimally invasive treatment in 520 patients with intracranial aneurysms.

OBJECTIVE: To summarize the experience of minimally invasive treatment in 520 patients with intracranial aneurysms on a retrospective study. METHODS: The measures used in the treatment of 520 patients were reviewed in terms of timing of surgery, induced-hypotensive anesthesia, brain protection combined with temporal occlusion of the feeding artery, external drainage of CSF, dynamic monitoring of intracranial pressure, blood flow velocity, serum osmolality and CT scanning, anti-vasospasm therapy as well as selected interventional endovascular embolization of aneurysms. RESULTS: Of the 520 patients, 485 were treated with either direct clipping or endovascular embolization and 35 patients were treated non-surgically. In 449 patients undergoing direct clipping and 36 undergoing endovascular embolization, intraoperative rupture of aneurysm occurred in 27 (6.0%) and 0%, respectively. Death occurred in 13 (2.6%), hemiplegia in 8 (1.6%), and vegetative state in 2 (0.4%). The operative mortality of direct clipping was 3.8% in 210 patients before 1990 and 1.8% in 275 patients after 1990 (36 patients undergoing endovascular embolization, the operative mortality was 0%). CONCLUSION: The outcome of patients with intacranial aneurysms can be markedly improved and the operative mortality can be lowered by minimally invasive treatment.

Adult↗