Biomedical subjects

Qun Wang

Publications and source records attributed to Qun Wang.

65 records · Page 4Linked to original sources

PubMed2003

[Glucocortioid treatment for heroin-induced spongiform leucoencephalopathy: a clinical controlled study].

OBJECTIVE: To evaluate the therapeutic effects of the glucocorticoid on heroin-induced spongiform leucoencephalopathy. METHODS: Twenty cases of heroin-induced spongiform leucoencephalopathy were randomly divided into the control group and the treating group with equal number. In the control group, the treatment was constituted by oral administration of vitamin B and coenzyme Q10 in a course of 1 month. In glucocorticoid treatment group, glucocorticoid (20 mg/d) for 10 d were given in addition to vitamin B and coenzyme Q10, and the dose of the glucocorticoid was gradually decreased afterwards. General observation and statistical analysis of function scores were performed in both groups before and 1, 6, 12 months after the treatment respectively. RESULTS: No significant difference in function scores was observed between the 2 groups, while the results of observation before and after the treatment were significantly different (P<0.05). The most significant difference occurred when comparing the observations made 1 month and 6 months respectively after treatment (P<0.001). CONCLUSION: Glucocorticoid has no obvious therapeutic effect on heroin-induced spongiform leucoencephalopathy, and rapid clinical recovery occurs within the initial 6 months of the treatment.

Adult↗

PubMed2003

[Effect of calpain on the degradation of tau protein in rat brain cortex extracts].

Calpain is a calcium-activated protease and has two ubiquitously distributed mammalian isoforms, namely calpain 1 (calpain I, mu-calpain and CAPN1) and calpain 2 (calpain II, m-calpain and CAPN2). Calpains regulate the function of many proteins by limited proteolysis. To determine the nature of different subtypes of calpain on degradation of microtubule-associated protein tau, the rat cortex extracts were incubated with 0.2 mmol/L, 1 mmol/L, 3 mmol/L and 5 mmol/L of CaCl(2 )for 15 min at 37 degrees C, respectively, and it was found that Ca(2+) treatment at concentrations 1-5 mmol/L led to significant proteolysis of the tau protein and this degradation was blocked by calpain inhibitor, calpeptin. In addition, when the extracts containing 1 mmol/L CaCl(2 )were treated with mu-calpain inhibitor (0.05 micromol/L of calpastatin) or m-calpain inhibitor (100 micromol/L calpain inhibitor IV) or both, the Ca(2+)-induced degradation of tau protein was blocked to about 8.6% 92.5% and 97.8% compared with the group with 1 mmol/L CaCl(2), respectively. These data suggest that both mu-calpain and m-calpain in brain cortex extracts are activated by Ca(2+) and both of them degraded tau protein, although, m-calpain plays a more important role in proteolysis of the tau protein.

Alzheimer Disease↗

PubMed2002

Resveratrol protects against global cerebral ischemic injury in gerbils.

Increased oxidative stress has been implicated in the mechanisms of delayed neuronal cell death (DND) following cerebral ischemic insult. In this study, we investigated whether resveratrol, a polyphenolic antioxidant enriched in grape, may ameliorate ischemia-induced neuron cell death. Mongolian gerbils were divided into three groups, namely, sham control, ischemia and ischemia treated with resveratrol. Transient global cerebral ischemia was induced by occlusion of both common carotid arteries (CCA) for 5 min. Resveratrol was injected i.p. (30 mg/kg body weight), either during or shortly after CCA occlusion, and again at 24 h after ischemia. Cerebral blood flow was monitored before and during CCA occlusion using a laser Doppler flowmeter. Brain sections were immuno-stained for neurons, astrocytes and microglial cells. A time course study was also carried out to assess the bioavailability of resveratrol in serum, liver and brain using high performance liquid chromatography (HPLC). Morphometric measurements indicated extensive DND in the hippocampal CA1 region 4 days after ischemia and that neuron cell death was marked by the increase in reactive astrocytes and microglial cells. Administration of resveratrol, either during or after CCA occlusion, significantly (P<0.05) decreased DND as well as glial cell activation. Analysis of resveratrol after i.p. injection indicated its presence in serum, liver and brain with peak activity at 1, 4 and 4 h, respectively. This study demonstrated for the first time that resveratrol, a polyphenolic antioxidant, can cross the blood-brain barrier and exert protective effects against cerebral ischemic injury.

Animals↗

PubMed2002

CASK and its target gene Reelin were co-upregulated in human esophageal carcinoma.

Calcium/calmodulin-dependent serine protein kinase (CASK) showed overexpression in human esophageal carcinoma by suppression subtractive hybridization. The upregulation of CASK gene and its target gene Reelin in human esophageal carcinoma tissues versus corresponding normal tissues was revealed by reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry or Western blot. Moreover, RT-PCR results indicated that the expression patterns of CASK and Reelin in human gastric carcinoma and colon carcinoma were different with those in esophageal carcinoma. Therefore, it suggested that CASK and Reelin were associated with tumorigenesis of esophagus and they were co-upregulated in human esophageal carcinoma.

Blotting, Western↗

PubMed2002

[Detection of level and mutation of neurofilament mRNA in Alzheimer's disease].

OBJECTIVE: To study if the increase of levels of neurofilament (NF)-M and NF-L in brain of Alzheimer's diseases (AD) is caused by increase of NF-M and NF-L. METHODS: Semi-quantitative reverse transcription PCR was used to measure the NF-M and NF-L mRNA levels in the brain gray matter obtained by autopsy from 8 patients with AD and 7 age-matched patients with Huntington's disease (HD) used as controls. The mutation of NF-M and NF-L was detected by single strand DNA conformation polymorphism technique. RESULTS: The levels of NF-M mRNA and NF-L mRNA were significantly lower in the brains of AD patients (0.3 +/- 0.03 * OD(NF-M)/OD(GAPDH) or OD(NF-L)/OD(GAPDH) and 0.44 +/- 0.16 * OD(NF-M)/OD(GAPDH) or OD(NF-L)/OD(GAPDH) respectively) than in the brains of HD patients (0.42 +/- 0.07 OD(NF-M)/OD(GAPDH) or OD(NF-L)/OD(GAPDH) and 0.79 +/- 0.09 OD(NF-M)/OD(GAPDH) or OD(NF-L)/OD(GAPDH) respectively) (P < 0.005 and P < 0.007 respectively). NF-M mutation was detected in one AD patient. No NF-L mutation was found in the samples examined. CONCLUSION: The increase of neurofilament protein observed in the brains of AD patients is related neither to increased gene transcription nor to mutation of NF mRNA.

Alzheimer Disease↗

PubMed2002

The C domain of netrin UNC-6 silences calcium/calmodulin-dependent protein kinase- and diacylglycerol-dependent axon branching in Caenorhabditis elegans.

Second messenger systems mediate neuronal responses to extracellular factors that elicit axon branching, turning, and guidance. We found that mutations in Caenorhabditis elegans that affect components of second messenger systems, a G-protein subunit, phospholipase Cbeta, diacylglycerol (DAG) kinase, and calcium/calmodulin-dependent protein kinase (CaMKII), have no obvious effect on axon responses to UNC-6 except in animals in which the N-terminal fragment, UNC-6DeltaC, is expressed. In these animals, the mutations enhance or suppress ectopic branching of certain axons. Netrin UNC-6 is an extracellular protein that guides circumferential migrations, and UNC-6DeltaC has UNC-6 guidance activity. We propose that the guidance response elicited by the UNC-6 N-terminal domains involves mechanisms that can induce branching that is sensitive to CaMKII- and DAG-dependent signaling, and that the UNC-6 C domain is required in cis to the N-terminal domains to silence the branching and to maintain proper axon morphology.

Alleles↗

PubMed2002

Diminished proliferation of B blast cell in response to cytokines in ethanol-consuming mice.

We and others have demonstrated that ethanol suppresses the antibody response in humans and animals. The purpose of this study was to determine whether ethanol affects cytokine-induced proliferative responses of splenic B blast cells, and whether the decreased response was due to an imbalance of the cytokine activity. Thus, the ability of spleen cells from individual ethanol-diet-fed C57BL/6 mice to proliferate and produce cytokines was determined. The ability of anti-IgM monoclonal antibodies (mAb)-activated splenic B blast cells in response to mouse recombinant IL-2 (rIL-2) or rIL-4 was also assessed. A thymidine incorporation assay was used to determine cell proliferation, and the conventional bioassays for cytokine-dependent cell proliferation were used for determining the bioactivity of cytokines. Data were analyzed with general linear model procedure. Our results showed that ethanol weakened the proliferative response of B cells in response to mitogen as well as to mouse rIL-2 and rIL-4. The decreased B cell responses may result from an increase in the production of IL-4 by helper T cells. Finally, in the presence of excessive dose of rIL-4, the proliferative responses of B blast cells from all three groups of mice were diminished (p<0.01). Thus, our data clearly indicated that the diminished B cell proliferation in ethanol-consuming mice was due in part to an excessive amount of IL-4 produced and an inability of the B cell to interact properly with IL-4 that was secreted by helper T cells. The results should extend our basic understanding of the mechanism by which chronic alcoholism impairs the interactions and interdependence of T- and B-cell immune functions.

Alcoholism↗

PubMed2002

[The application of transcranial Doppler in detecting diabetic cerebral macroangiopathy and microangiopathy].

OBJECTIVE: To evaluate the application of transcranial Doppler (TCD) in the detection of cerebral hemodynamic changes in diabetic macroangiopathy and microangiopathy. METHODS: 81 of diabetic patients and 62 age-, gender- matched healthy controls were monitored with TCD in this study. The pulsatility index (PI) and mean flow velocities (Vm) between the patients and healthy controls, between the patients with microangiopathic complications and patients without complication, were analyzed respectively. RESULTS: The PIs of arteries and Vms of the extracranial internal carotid artery (ICA), middle cerebral artery (MCA) and basilar artery (BA) were significantly higher in diabetic patients than those in healthy controls (P < 0.001), while PIs of ICA and MCA but not BA were significantly increased in patients with complications than those in noncomplicated patients (P < 0.001). CONCLUSIONS: It indicated that PI and Vm might be two useful markers for the detection of diabetic cerebrovascular changes. Marked increase of PIs of ICA and MCA might reflect the microangiopathic changes of cerebral vessels in diabetic patients.

Anterior Cerebral Artery↗

PubMed2002

Single photon emission computerized tomography of spongiform leukoencephalopathy heroin addicts: analysis of 10 cases.

OBJECTIVE: To investigate the changes in cerebral circulation in heroin addicts with pongiform leukoencephalopathy. METHODS: Single photon emission computerized tomography (SPECT) was performed in 10 such patients. RESULTS: Regional cerebral blood flow (rCBF) in the involved white matter of bilateral cerebral and cerebellar hemispheres was obviously reduced. rCBF of temporal lobes, parietal lobes, cerebellar hemispheres and basal ganglion were reduced in varying degrees. CONCLUSION: As demonstrated by the result of SPECT, rCBF in the white matter of bilateral cerebral and cerebellar hemispheres was reduced with partial involvement of the gray matter of heroin addicts with spongiform leukoencephalopathy.

Adult↗

PubMed2002

In vitro analysis of tau phosphorylation sites and its biological activity.

OBJECTIVE: To explore the association between the abnormal phosphorylation sites found in Alzheimer disease (AD) tau and the inhibition of its biological activity. METHODS: Ultracentrifugation, chromatography, manual Edman degradation and autosequence techniques were used to prepare and phosphorylate human recombinant tau, isolate and purify 32P tau peptides and determine phosphorylation sites. RESULTS: Phosphorylation of tau by casein kinase 1 (CK-1), cyclic AMP-dependent protein kinase (PKA) and glycogen synthetase kinase 3 (GSK-3) separately inhibited its biological activity and the inhibition of this activity by (CSK-3 was significantly increased if tau was prephosphorylated by CK-1 or PKA. The most potent inhibition was seen by a combined phosphorylation of tau with PKA and GSK-3. The treatment of tau by PKA and GSK-3 combination induced phosphorylation of tau at Ser-195, Ser-198, Ser-199, Ser-202, Thr-205, Thr-231, Ser-235, Ser-262, Ser-356, Ser-404, whereas Thr-181, Ser-184, Ser-262, Ser-356 and Ser-400 were phosphorylated by GSK-3 alone under the same condition. CONCLUSION: Phosphorylation of tau by PKA plus GSK-3 at Thr-205 might play a key role in tau pathology in AD.

Alzheimer Disease↗

PubMedDate not supplied

Endotoxin removal using a synthetic adsorbent of crystalline calcium silicate hydrate.

A synthetic adsorbent of crystalline calcium silicate hydrate, the product LRA by Advanced Minerals Corp., has been studied for endotoxin removal from aqueous solutions. This adsorbent removes endotoxin effectively, and the removal is greatly enhanced by the presence of an electrolyte such as NaCl, Tris-HCl, or Na2HPO4. It has an endotoxin removal capacity as high as 6 million endotoxin units (EU) per gram. Its endotoxin removal kinetics is fast, and for instance, over 99.9% endotoxin in a 5000 EU/mL solution was removed by mixing for 2 min at an adsorbent usage of 10 g/L. Using the chromatographic column method to treat a 5000 EU/mL solution, an endotoxin log-reduction factor of 6.2 was achieved with a single pass. This adsorbent also demonstrated significantly better performance when compared to many commonly used endotoxin removal agents, such as ActiClean Etox Endotoxin Removal Resin, Affi-Prep Polymyxin Support, Detroxi-Gel Endotoxin Removing Gel, Q Sepharose Fast Flow Media, and Sigma Endotoxin Removal Solution. Furthermore, it demonstrated a high selective removal of endotoxin from a solution of lambda DNA. This adsorbent provides opportunities for developing disposable, scaleable, and cost-effective methods for endotoxin reduction in many biotechnological and pharmaceutical processes.

Adsorption↗