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Q Wu

Publications and source records attributed to Q Wu.

At least 91 records · Page 5Linked to original sources
PubMed2001

Analysis of prognostic predictors in idiopathic membranous nephropathy.

We studied clinical and histologic parameters at the time of renal biopsy of 19 patients with idiopathic membranous nephropathy (IMN) to investigate the predictors for prognosis of IMN. Nineteen patients diagnosed by open renal biopsy between 1988 and 1993 and followed for at least 5 years were divided into two groups according to the latest follow-up renal function. Group I included 16 patients with normal renal function at the last follow-up point. Group II included three patients with end-stage renal failure at the last follow-up point. Antibodies to CD68, CD45RO, alpha-SMA, collagen IV, and collagen VI were used to investigate glomerular and interstitial changes in biopsy specimens by the indirect enzyme-labeled antibody method. Degree of global glomerulosclerosis, segmental glomerulosclerosis, adhesion to Bowman's capsule, and crescent formation were evaluated by light microscopy (periodic acid-Schiff, periodic acid-metheramine [PAM] staining). The difference between the two groups was analyzed by Mann-Whitney U: test. The number of interstitial cells, the number of interstitial CD45RO-positive cells, and increases of interstitial collagen IV and VI were found to be the most important factors for prognosis of IMN. These findings suggest that the extent of tubulointerstitial changes (cellular infiltration and fibrosis) determines the prognosis of renal function in IMN.

Adolescent↗
PubMed2001

Partial recovery of light-independent chlorophyll biosynthesis in the chlL-deletion mutant of Synechocystis sp. PCC 6803.

A chlL-deletion mutant of Synechocystis sp. PCC 6803 designated as chlL- was unable to make significant amounts of chlorophyll in darkness. However, an apparent pseudorevertant has been generated spontaneously that can synthesize an increased amount of chlorophyll under light-activated heterotrophic growth conditions. Under these conditions, the chlorophyll content in this pseudorevertant was about 20% of that in the wild-type strain and about 4 times more than that in the original and in the recently recreated chlL-deletion mutant. This is paralleled by increased performance of dark-grown cells in terms of chlorophyll fluorescence induction and oxygen evolution rates in the pseudorevertant versus in the original mutant. PCR analysis confirmed that the chlL- -pseudorevertant mutant still lacked the chlL gene. These results imply that the light-independent chlorophyll biosynthesis pathway was partly recovered.

Bacterial Proteins↗
PubMed2001

Comparative DNA sequence analysis of mouse and human protocadherin gene clusters.

The genomic organization of the human protocadherin alpha, beta, and gamma gene clusters (designated Pcdh alpha [gene symbol PCDHA], Pcdh beta [PCDHB], and Pcdh gamma [PCDHG]) is remarkably similar to that of immunoglobulin and T-cell receptor genes. The extracellular and transmembrane domains of each protocadherin protein are encoded by an unusually large "variable" region exon, while the intracellular domains are encoded by three small "constant" region exons located downstream from a tandem array of variable region exons. Here we report the results of a comparative DNA sequence analysis of the orthologous human (750 kb) and mouse (900 kb) protocadherin gene clusters. The organization of Pcdh alpha and Pcdh gamma gene clusters in the two species is virtually identical, whereas the mouse Pcdh beta gene cluster is larger and contains more genes than the human Pcdh beta gene cluster. We identified conserved DNA sequences upstream of the variable region exons, and found that these sequences are more conserved between orthologs than between paralogs. Within this region, there is a highly conserved DNA sequence motif located at about the same position upstream of the translation start codon of each variable region exon. In addition, the variable region of each gene cluster contains a rich array of CpG islands, whose location corresponds to the position of each variable region exon. These observations are consistent with the proposal that the expression of each variable region exon is regulated by a distinct promoter, which is highly conserved between orthologous variable region exons in mouse and human.

Animals↗
PubMed2001

Acceleration of dose calculations for intensity-modulated radiotherapy.

The requirements and trade-offs between accuracy and speed for radiotherapy dose computations have been discussed for decades. Inverse planning used for intensity-modulated radiotherapy (IMRT) optimization imposes additional demands on dose calculation since it is an iterative process in which dose calculations might be repeated many (10's to 1000's) of times. This work discusses the accuracy and speed issues as related to IMRT dose calculations. A hybrid dose calculation method which accelerates the optimization process is proposed and applied in which a fast-pencil beam (PB) model is used for initial optimization iterations, followed by superposition/convolution (SC) calculations. Optimization dose results are compared for pure PB optimization, pure SC optimization, and PB optimization followed by SC optimization. Plans were evaluated in terms of isodose coverage, dose-volume histograms, and total dose calculation time for five head and neck cases with diverse locations, sizes, and shapes for tumors and critical structures. Patient plans were designed for nine equispaced beams. For one patient, an additional five-beam configuration was tested. We found that gross features of intensity distributions resulting from all schemes were similar, however there were differences in the fine detail. Differences were small between composite dose distributions optimized with PB and SC methods, yet differences in individual beam dose distributions were quite significant. When the SC method was used to compute dose following optimization with PB method, dose differences were reduced significantly both for composite plans and for individual beams. Substantial overall timesavings were observed, allowing IMRT dose planning to become a more interactive activity.

Algorithms↗
PubMed2001

Cancer gene therapy by adenovirus-mediated gene transfer.

Cancer arises as a direct result of genetic mutations. It therefore stands to reason that cancer should be well suited for the correction through gene therapy. Recent advances in the understanding of the molecular pathogenesis of cancer and the rapid development of recombinant DNA technology have made cancer gene therapy feasible in the clinical setting. The current efforts for cancer gene therapy mainly focus on immunogene therapy, chemogene therapy, restoration of tumor suppressor gene function, and oncolytic virus therapy. Central to all these therapies is the development of efficient vectors for gene delivery--this remains a work in progress. These vectors can be classified as viral and non-viral vectors. This paper will concentrate on viral vectors because of their practical advantages over non-viral vectors. Of the viral vectors, by far the most important are the human adenoviruses as is reflected by the enormous data and literature accumulated by studies relating to animal tumor models and clinical trials. In this review, we examine the recent progress in adenovirus-mediated cancer gene therapy with regard to cytokine gene, tumor suppressor gene, chemogene, and oncolytic adenovirus. We also discuss the current limitations of the adenoviral vector system and how they may be circumvented in future developments relating to targeted gene delivery.

Adenoviridae↗
PubMed2001

The effect pathway of retinoic acid through regulation of retinoic acid receptor alpha in gastric cancer cells.

AIM: To evaluate the role of RARalpha gene in mediating the growth inhibitory effect of all-trans retinoic acid (ATRA) on gastric cancer cells. METHODS: The expression levels of retinoic acid receptors (RARs) in gastric cancer cells were detected by Northern blot. Transient transfection and chlorophenicol acetyl transferase (CAT) assay were used to show the transcriptional activity of beta retinoic acid response element (betaRARE) and AP-1 activity. Cell growth inhibition was determined by MTT assay and anchorage-independent growth assay, respectively. Stable transfection was performed by the method of Lipofectamine, and the cells were screened by G418. RESULTS: ATRA could induce expression level of RARalpha in MGC80-3, BGC-823 and SGC-7901 cells obviously, resulting in growth inhibition of these cell lines. After sense RARalpha gene was transfected into MKN-45 cells that expressed rather low level of RARalpha and could not be induced by ATRA, the cell growth was inhibited by ATRA markedly. In contrast, when antisense RARalpha gene was transfected into BGC-823 cells, a little inhibitory effect by ATRA was seen, compared with the parallel BGC-823 cells. In transient transfection assay, ATRA effectively induced transcriptional activity of betaRARE in MGC80-3, BGC-823, SGC-7902 and MKN/RARalpha cell lines, but not in MKN-45 and BGC/aRARalpha cell lines. Similar results were observed in measuring-antiAP-1 activity by ATRA in these cancer cell lines. CONCLUSION: ATRA inhibits the growth of gastric cancer cells by up-regulating the level of RARalpha RARalpha is the major mediator of ATRA action in gastric cancer cells; and adequate level of RARalpha is required for ATRA effect on gastric cancer cells.

Agar↗
PubMed2001

Clinical outcome of patients with previous myocardial infarction and left ventricular dysfunction assessed with myocardial (99m)Tc-MIBI SPECT and (18)F-FDG PET.

UNLABELLED: Myocardial viability was assessed by (99m)Tc-methoxyisobutylisonitrile (MIBI) SPECT and (18)F-FDG PET to evaluate the prognosis and treatment strategy of patients with myocardial infarction (MI) and left ventricular (LV) dysfunction. METHODS: One hundred twenty-three consecutive patients with previous MI and LV dysfunction (LV ejection fraction [EF], 35% +/- 6% [mean +/- SD]) who underwent (99m)Tc-MIBI SPECT and FDG PET were followed-up for 26 +/- 10 mo (mean +/- SD). Distributions of the 2 radiotracers in myocardial segments were classified into 2 patterns: myocardial perfusion-metabolism mismatch (MM) and match (M). LV EF and LV end-diastolic diameter (EDD) were measured by echocardiography at baseline, 3 mo (Pos1), and 6 mo (Pos2) after revascularization. Cardiac death, acute MI, unstable angina, and late revascularization (>3 mo) experienced by the patients during follow-up were defined as cardiac events. RESULTS: Sixty-seven patients underwent revascularization and 56 patients were treated medically. Of the 72 patients with > or =2 MM segments, 42 underwent revascularization (group A1) and 30 were treated medically (group A2). Of the 51 patients with <2 MM segments, 25 underwent revascularization (group B1) and 26 were treated medically (group B2). The 4 groups had similar baseline characteristics and rest LV EF. After revascularization, EF (mean +/- SD) increased in group A1 from 36% +/- 5% to 44% +/- 8% (P < 0.0001) in Pos1 and to 51% +/- 9% (P < 0.0001) in Pos2. EDD (mean +/- SD) decreased from 62 +/- 8 mm to 56 +/- 5 mm (P < 0.001) in Pos1 and to 55 +/- 5 mm (P < 0.001) in Pos2. However, EF and EDD were unchanged in group B1 (P > 0.05). During the follow-up, 22 patients (17.9%) suffered from cardiac events, including 11 cardiac deaths, 4 acute MI, 6 late coronary artery bypass grafting, and 1 unstable angina pectoris. The cardiac event rate in group A2 (50%) was significantly higher than that of groups A1 (2.4%; chi(2) = 23.08; P < 0.0001), B1 (12%; chi(2) = 8.94; P = 0.003), and B2 (11.5%; chi(2) = 9.45; P = 0.002). CONCLUSION: Assessment of myocardial viability using hybrid (99m)Tc-MIBI SPECT and FDG PET can predict the clinical outcome and is helpful to decision making in the treatment strategy of patients with MI and LV dysfunction. Revascularization can improve the LV function and clinical outcome of patients with >2 viable myocardial segments.

Aged↗
PubMed2001

Sludge digestion enhancement and nutrient removal from anaerobic supernatant by Mg(OH)2 application.

Anaerobic sludge digestion is a widely adopted process for sludge stabilization. Phosphate removal from anaerobic supernatant is necessary to limit the phosphate returned to the head of the treatment plant, thereby improving the overall treatment efficiency. In this study, magnesium hydroxide (Mg(OH)2) was used to improve the sludge digestion efficiency and to remove phosphorus from anaerobic supernatant. The anaerobic sludge digestion experiment was conducted at a pilot scale, and the results showed that applying Mg(OH)2 to anaerobic sludge digester resulted in a larger reduction in SS and COD, a higher biogas production rate, a lower level of phosphate and ammonia nitrogen concentrations in the sludge supernatant and an improved sludge dewaterability. Research results at both lab scale and pilot scale on phosphorus removal from anaerobic supernatant using Mg(OH)2 showed that a high removal of phosphorus can be achieved through the addition of Mg(OH)2. The required reaction time depends on the initial phosphorus concentration and the Mg(OH)2 dosage.

Ammonia↗
PubMed2001

[Preparation, characterization and characteristics of copolypeptide consisting of L-aspartic acid and L-glutamic acid].

For the purpose of increasing the hydrophilicity of poly-aspartic acid, a copolypeptide consisting of L-aspartic acid and L-glutamic acid (8: 2 mol/mol) was prepared. The copolymer was characterized by 1H NMR, 13C NMR, differential scanning calorimetry, X-ray and element analysis. 3-hydroxyamino, as a side chain, was linked to the polymer, and poly-(3-hydroxypropyl)-L-aspartamide-L-glutamide (PHPAG) was obtained. The molecular weight of PHPAG was determined by GPC. Tests of the PHPAG on laboratory animals corroborated its potential use as a drug carrier. Acute toxicity studies revealed no death in animals treated, other studies recorded no notable difference between treated and control animals either in terms of principal haematological parameters or in micronucleus test. In vitro enzymatic hydrolysis for the co-polymer was performed using chymotrypsin, fungi protease and trypsin. It showed that these proteins could degrade the copolymer to some degree. The effects of pH, light and humidity on PHPAG were also investigated. The results indicated that it was stable under the experiment conditions.

Animals↗
PubMed2001

[Determination of +Gz tolerance end-point by steady state visual evoked potential].

OBJECTIVE: To study the possibility of applying steady-state visual evoked potential (SSVEP) to detect the end-point of +Gz tolerance. METHOD: When a subject was exposed to +Gz acceleration on a human centrifuge, the SSVEP signals (evoked by LED lamps triggered by 8 Hz pulse train) were recorded. The characters of SSVEP in frequency domain were extracted by adaptive filtering, and a modified T2circ statistic was used to determine the visual obstruct objectively. RESULT: SSVEP had strong relationship with visual obstruct of the subjects during +Gz exposure. CONCLUSION: SSVEP might be used as an objective criterion for determination of end-point of +Gz tolerance and an index of the degree of symptoms as well. But, multi-parameter method seemed still necessary to get reliable estimations.

Acceleration↗
PubMed2001

Aortic root replacement.

OBJECTIVE: To report our operative experience with aortic root replacement in 231 patients with aortic root aneurysm and discuss the current indications, methods, and surgical techniques. METHODS: Between January 1994 and August 1999, a group of 231 consecutive patients underwent aortic root replacement at our hospital, with 13 being treated on an emergency basis. There were 189 men and 42 women, ranging in age from 14 to 69 years. The diameter of the aneurysm varied from 4.5 to 11 cm. Among this group, 145 had isolated aortic root aneurysms, 65 suffered from DeBakey type I aortic dissection, and the remaining 21 were diagnosed as having DeBakey type II aortic dissection. Aortic valve regurgitation occurred in all cases. Aortic root replacement was performed with composite valved graft in 229 patients, and in 2 patients the aortic valve was preserved. RESULTS: The hospital mortality rate was 3.03% (7 patients). Early complications included re-exploration for bleeding in 6 patients, pericardial effusion in 9, as well as cerebral infarction, pleural effusion, and pneumothorax in 2 patients each. One hundred and seventy-five patients (78.12%) were followed up, with a mean follow-up time of 15.7 +/- 13.1 months (range, 2 weeks to 65 months). One patient died from lower-limb embolism and renal dysfunction 3 months postoperatively. Three patients died from postoperative anticoagulation accidents. The preoperative and postoperative mean left ventricular end-diastolic diameters were significantly different (68.1 +/- 9.4 mm, range 54 to 112 mm; vs 54.8 +/- 8.2 mm, range 38 to 88 mm; P < 0.001). CONCLUSIONS: Once a diagnosis of acute aortic root dissecting aneurysm is made, the patient should undergo surgery as soon as possible if the general conditions permit. Aortic aneurysm without dissection or with chronic dissection should be operated if the diameter of the aneurysm is greater than 5 cm.

Adolescent↗
PubMed2001

Protective effect and mechanism of Ginkgo biloba leaf extracts for Parkinson disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine.

AIM: To observe the effects of extracts of Ginkgo biloba leaves (EGb) on the Parkinson disease (PD) models induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its ion 1-methyl-4-phenylpyridinium (MPP+). METHODS: MPTP was microinjected into substantia nigra of rats to induce a behavior change of rotation. EGb (ip, 50 or 100 mg.kg(1 . d-1) was pretreated consecutively for 19 d before MPTP administered and 1 d after MPTP administered. The contents of malondialdehyde (MDA), superoxide dismutase (SOD), and dopamine (DA) in substantia nigra of model rats were determined. Apoptosis of PC12 cells was induced by MPP+, and the protective effect of EGb (25, 50, and 100 mg/L) was also observed. The cells of apoptosis were observed under a microscope and counted under a fluoroscope after stained with AO/EB. RESULTS: EGb (100 mg . kg-1 . d-1) decreased the duration and frequency of the rotation of rats (P < 0.05, n = 10 ) while EGb (50 or 100 mg/L)inhibited the decreases of DA and SOD and the increase of MDA induced by MPTP, (P < 0.05 or P < 0.01, n = 10). MPP+ (10 micromol/L) induced the apoptosis of PC12 cells, and EGb (50 or 100 mg/L) prevented cells from apoptosis at 6 h, 12 h, and 24 h (P < 0.05 or P < 0.01, n = 3). CONCLUSION: EGb possesses protective effect on the PD models in vivo and in vitro. The anti-oxidation and anti-apoptosis may be one of the mechanisms underlying the neuroprotective effect of EGb.

Animals↗
PubMed2001

[Surgical treatment of DeBakey type I and II aortic dissection].

OBJECTIVE: Aortic dissection is associated with significant mortality and morbidity. Effective methods to treat aortic disection are now available although these lesions still challenge the cardiovascular surgeon. METHODS: From January 1994 to January 2000. 131 patients with DeBakey I, II type aortic dissection underwent surgical treatment. Operations were performed under cardiopulmonary bypass in 59 patients. Hypothermic circulatory arrest was used in 15 patients. Hypothermic circulatory arrest and selective cerebral perfusion was used in 57 patients. A graft replacement of ascending aorta and partial aortic arch was performed in 25 patients, ascending aorta and total aortic arch in 10. 83 patients underwent the Bentall procedure. The Bentall procedure and total aortic arch replacement were performed in 3 patients, the Wheats operation in 4. 4 patients underwent the elephant trunk techniques and 2 patients with the elephant trunk techniques and the Bentall procedures. RESULTS: There were 4 deaths within 30 days after surgery with an operative mortality of 3.05%, and 3 neurological dysfunction undergone hypothermic circulatory arrest. They were recovered within 1 week. CONCLUSION: The operative technique is difficult. Selective cerebral perfusion can provide available protection during surgery of aortic dissection. It prolongs the time allowed to performed the aortic repair.

Adolescent↗
PubMed2001

Surgical treatment of 52 patients with congenital coronary artery fistulas.

OBJECTIVE: To evaluate the outcome of surgical treatment for congenital coronary artery fistulas (CAF) in 52 patients seen between May 1988 and July 1999. METHODS: Fifty-two patients ranging in age from 9 months 58 years (mean 15.7 +/- 16.4 years) were studied. Thirty-six patients had no other cardiac defects, 9 of those patients were more than 20 years old and presented with symptoms. Only one of 36 patients less than 20 years old had clinical findings before surgery. Sixteen patients had associated cardiac lesions. The site of fistula origin was the right coronary artery in 37 patients (71.2%), and the left coronary artery in 15 patients (28.8%). The sites of CAF drainage were the right ventricle, right atrium, left ventricle, left atrium and pulmonary artery in 22 (42.3%), 16 (30.8%), 6 (11.5%), 3 (5.8%), and 5 (9.6%) patients, respectively. The mean diameter of the fistula in 43 patients with single ostium was 7.34 +/- 4.12 mm. RESULTS: Cardiopulmonary bypass was used in all patients and no patient died. An arteriotomy was made on the anomalous coronary artery and the proximal opening of a fistula was closed within the vessel in 10 patients. Closure of the distal opening of a fistula draining into a cardiac chamber or pulmonary artery was performed in 26 patients. In 16 patients, both the proximal and distal opening were closed. Two and 3 distal opening of a fistula were found in 6 and 3 patients, respectively. No residual shunt was found before patients were discharged from the hospital. Forty patients were followed up for a mean period of 3.14 +/- 1.84 years. The remaining 12 patients could not be contacted during follow-up. No clinical symptoms were found in those patients during follow-up but one patient still presented with ST-T change. CONCLUSION: Early and properly surgical management is safe and effective for congenital coronary fistula.

Adolescent↗
PubMed2001

Growth inhibition of gastric cancer cells by all-trans retinoic acid through arresting cell cycle progression.

OBJECTIVE: To investigate the mechanism of all-trans retinoic acid (ATRA) on the regulation of the cell cycle in gastric cancer cells. METHODS: The protein level was detected by Western blot. Immunoprecipitation was used in protein kinase activity determination. Cell growth and cell cycle phase were examined by MTT assay and flow-cytometric analysis, respectively. RESULTS: ATRA could effectively induce G0/G1 arrest and inhibit cell growth in certain human gastric cancer cell lines. ATRA might induce p21WAF1/CIP1 expression in ATRA-sensitive cell lines through p53-dependent and p53-independent pathways. Induction of p21WAF1/CIP1 caused decrease in CDK4 and CDK2 activities independent of CDK4 and CDK2 protein expression levels. In addition, the dephosphorylated form of Rb protein increased because of the down-regulation of CDK4 and CDK2 activities by ATRA. CONCLUSIONS: Growth inhibition on gastric cancer cells by ATRA occurs through the regulation of relevant proteins leading to the arrest of cell cycle progression.

Antineoplastic Agents↗
PubMed2001

Evaluation of coronary artery bypass graft patency using three-dimensional reconstruction and flow study of electron beam tomography.

OBJECTIVE: To establish and evaluate two protocols for the noninvasive visualization and assessment of coronary artery bypass graft (CABG) patency on electron beam tomography (EBT). METHODS: Two hundred and fourteen consecutive patients who underwent coronary artery bypass graft surgery were scanned using both EBT angiography with 3-dimensional reconstruction and EBT flow study with time-density-curve analysis. RESULTS: There were 589 CABGs evaluated in this study (10 grafts were excluded because of artifacts). Among them, 133 (98.5%) of 135 arterial grafts were patent, and 345 (77.7%) of 444 saphenous-vein grafts were patent. Within 5 years or between 5 and 10 years after operation, arterial graft patency exceeded venous graft patency (P < 0.001). Three-dimensional EBT angiography achieved higher sensitivity, specificity and accuracy (97.7%, 94.1% and 96.7%, respectively) than did EBT flow study (88.4%, 82.4% and 85.2%, respectively) for evaluating occlusion or patency of CABG. The intra-graft flow of patent arterial and venous grafts were 4.9 +/- 2.2 ml.min-1.g-1 and 6.9 +/- 2.8 ml.min-1.g-1, respectively (P < 0.001). CONCLUSION: The combination of EBT three-dimensional reconstruction and flow study can be more effective in the assessment of CABG anatomy and quantification of patent CABG blood flow.

Adult↗
PubMed2001

[Distal intramural spread of rectal cancer studied on large slices].

OBJECTIVE: To study the length of distal intramural spread of rectal cancers, and provide evidence for anal-preserving operations. METHODS: Specimens of ninety-eight patients with rectal cancers who had been operated from August, 1996 to October, 1997, were collected and their large pathologic slices examined. The length of intramural spread distal to rectal cancers was measured under light microscope. The actual length of spread in live conditions was estimated according to equal proportional shrinkage. RESULTS: In 48 of the 98 patients, distal intramural spread of the tumor was observed. The length of spread varied from 0.1 cm to 2.5 cm. In 77% of the 48 patients, the length of tumor spread was < 0.5 cm. In only 5 patients was the distance of spread > or = 1.0 cm. Four different ways of tumor invasion were observed: contiguous, lymphatic, neural and venous invasion. Distal intramural spread could be via mucosa, submucosa, inner circular muscular layer, outer longitudinal muscular layer or serosa, either separately or concomitantly. CONCLUSION: Distal intramural spread of rectal cancers can be detected in about 1/2 of the specimens examined on large pathologic slice. In most of them the distance of spread is < 0.5 cm. Occasionally it may be > or = 1 cm. To set the edge of resection > or = 3 cm distal to the rectal cancers is relatively safe in anal-preserving operations.

Colorectal Neoplasms↗