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S Hu

Publications and source records attributed to S Hu.

At least 73 records · Page 4Linked to original sources
PubMed2001

Systemic cytokine response in children bitten by snakes in Costa Rica.

BACKGROUND: To characterize the host response to venom from snakes of the family Viperidae in Costa Rica, we investigated the release of cytokines: IL-1, IL-6, IL-8, TNF-alpha, MIP-1beta, and RANTES in pediatric patients who were bitten by a snake. METHODS: Patients were included in this study if they were admitted to the hospital within 24 hours of the snakebite. Blood samples were taken immediately on admission to the hospital, and then at intervals of 3, 12, and 24 hours, and on days 3, 5, and 7 after the accident. Patients received gentamicin plus clindamycin or gentamicin plus penicillin intravenously for a minimum of 3 days or longer if necessary. IL-1, IL-8, TNF-alpha, MIP-1beta, and RANTES were determined by monoclonal antibody-based ELISAs, while IL-6 was determined by bioassay. RESULTS: Eighteen patients were included in this study; 15 were bitten by Bothrops asper and three by B. lateralis. Eleven patients were male. Median (range) age was 9 (1-12) years. Nine patients had detectable serum concentrations of IL-6 (200 pg/ mL) and IL-8 (51 pg/mL) on admission, increasing to 500 pg/mL and 115 pg/mL for IL-6 and IL-8, respectively, during the first 12-24 hours. Cytokine concentrations returned to normal or undetectable ranges by 72 hours. TNF-alpha concentrations peaked at 12 hours (mean: 48 pg/mL). Low, but detectable concentrations of MIP-1beta were observed in some patients at various time intervals (48 pg/mL), whereas IL-1 was not detectable at any time point. Regulated on Activation Normal T cell Expressed and Secreted (RANTES) concentrations were evaluated in only five patients, being elevated in all of them. Patients with elevated cytokine concentrations required early fasciotomy (<24 hours after the accident) more often than those who had normal or undetectable cytokine concentrations (P < 0.05). There were no statistically significant associations between severity of envenomation, or outcome, and elevated serum cytokine concentrations (P > 0.05). CONCLUSIONS: Bothrops sp snake venoms induce clinical and pathophysiologic alterations similar to acute trauma, with release of proinflammatory cytokines. A better understanding of the role of the inflammatory response could lead to the development of new therapeutic strategies to improve the outcome in snakebitten patients.

Animals↗
PubMed2001

Association of DRD4 with attention problems in normal childhood development.

Several previous studies found an association of clinically diagnosed attention deficit hyperactivity disorder with long alleles of a variation in the DRD4 dopamine receptor gene exon III coding sequence. We evaluated the DRD4 polymorphism in a non-clinically selected sample of children for whom maternal reports of attention problems were available at 4 and 7 years of age. There was a significant elevation in attention problem scores in children carrying DRD4 long alleles that accounted for 3-4% of total variation at each age and for 5-7% of the temporally stable component of the phenotype. Our results show that the DRD4 gene influences normal as well as pathological attention processes, and the results highlight the utility of longitudinal measurements in psychiatric genetics.

Attention Deficit Disorder with Hyperactivity↗
PubMed2001

Analysis of the cat eye syndrome critical region in humans and the region of conserved synteny in mice: a search for candidate genes at or near the human chromosome 22 pericentromere.

We have sequenced a 1.1-Mb region of human chromosome 22q containing the dosage-sensitive gene(s) responsible for cat eye syndrome (CES) as well as the 450-kb homologous region on mouse chromosome 6. Fourteen putative genes were identified within or adjacent to the human CES critical region (CESCR), including three known genes (IL-17R, ATP6E, and BID) and nine novel genes, based on EST identity. Two putative genes (CECR3 and CECR9) were identified, in the absence of EST hits, by comparing segments of human and mouse genomic sequence around two solitary amplified exons, thus showing the utility of comparative genomic sequence analysis in identifying transcripts. Of the 14 genes, 10 were confirmed to be present in the mouse genomic sequence in the same order and orientation as in human. Absent from the mouse region of conserved synteny are CECR1, a promising CES candidate gene from the center of the contig, neighboring CECR4, and CECR7 and CECR8, which are located in the gene-poor proximal 400 kb of the contig. This latter proximal region, located approximately 1 Mb from the centromere, shows abundant duplicated gene fragments typical of pericentromeric DNA. The margin of this region also delineates the boundary of conserved synteny between the CESCR and mouse chromosome 6. Because the proximal CESCR appears abundant in duplicated segments and, therefore, is likely to be gene poor, we consider the putative genes identified in the distal CESCR to represent the majority of candidate genes for involvement in CES.

Abnormalities, Multiple↗
PubMed2001

High-throughput SNP genotyping by allele-specific PCR with universal energy-transfer-labeled primers.

We have developed a new method for high-throughput genotyping of single nucleotide polymorphisms (SNPs). The technique involves PCR amplification of genomic DNA with two tailed allele-specific primers that introduce priming sites for universal energy-transfer-labeled primers. The output of red and green light is conveniently scored using a fluorescence plate reader. The new method, which was validated on nine model SNPs, is well suited for high-throughput, automated genotyping because it requires only one reaction per SNP, it is performed in a single tube with no post-PCR handling, the same energy-transfer-labeled primers are used for all analyses, and the instrumentation is inexpensive. Possible applications include multiple-candidate gene analysis, genomewide scans, and medical diagnostics.

Alleles↗
PubMed2001

Automatic lung segmentation for accurate quantitation of volumetric X-ray CT images.

Segmentation of pulmonary X-ray computed tomography (CT) images is a precursor to most pulmonary image analysis applications. This paper presents a fully automatic method for identifying the lungs in three-dimensional (3-D) pulmonary X-ray CT images. The method has three main steps. First, the lung region is extracted from the CT images by gray-level thresholding. Then, the left and right lungs are separated by identifying the anterior and posterior junctions by dynamic programming. Finally, a sequence of morphological operations is used to smooth the irregular boundary along the mediastinum in order to obtain results consistent with those obtained by manual analysis, in which only the most central pulmonary arteries are excluded from the lung region. The method has been tested by processing 3-D CT data sets from eight normal subjects, each imaged three times at biweekly intervals with lungs at 90% vital capacity. We present results by comparing our automatic method to manually traced borders from two image analysts. Averaged over all volumes, the root mean square difference between the computer and human analysis is 0.8 pixels (0.54 mm). The mean intrasubject change in tissue content over the three scans was 2.75% +/- 2.29% (mean +/- standard deviation).

Algorithms↗
PubMed2001

Glucose-dependent and glucose-sensitizing insulinotropic effect of nateglinide: comparison to sulfonylureas and repaglinide.

Nateglinide, a novel D-phenylalanine derivative, stimulates insulin release via closure of K(ATP) channels in pancreatic beta-cell, a primary mechanism of action it shares with sulfonylureas (SUs) and repaglinide. This study investigated (1) the influence of ambient glucose levels on the insulinotropic effects of nateglinide, glyburide and repaglinide, and (2) the influence of the antidiabetic agents on glucose-stimulated insulin secretion (GSIS) in vitro from isolated rat islets. The EC50 of nateglinide to stimulate insulin secretion was 14 microM in the presence of 3 mM glucose and was reduced by 6-fold in 8 mM glucose and by 16-fold in 16 mM glucose, indicating a glucose-dependent insulinotropic effect. The actions of glyburide and repaglinide failed to demonstrate such a glucose concentration-dependent sensitization. When tested at fixed and equipotent concentrations (approximately 2x EC50 in the presence of 8 mM glucose) nateglinide and repaglinide shifted the EC50s for GSIS to the left by 1.7 mM suggesting an enhancement of islet glucose sensitivity, while glimepiride and glyburide caused, respectively, no change and a right shift of the EC50. These data demonstrate that despite a common basic mechanism of action, the insulinotropic effects of different agents can be influenced differentially by ambient glucose and can differentially influence the islet responsiveness to glucose. Further, the present findings suggest that nateglinide may exert a more physiologic effect on insulin secretion than comparator agents and thereby have less propensity to elicit hypoglycemia in vivo.

Animals↗
PubMed2001

Effectiveness of nateglinide on in vitro insulin secretion from rat pancreatic islets desensitized to sulfonylureas.

Chronic exposure of pancreatic islets to sulfonylureas (SUs) is known to impair the ability of islets to respond to subsequent acute stimulation by SUs or glucose. Nateglinide (NAT) is a novel insulinotropic agent with a primarily site of action at beta-cell K(ATP) channels, which is common to the structurally diverse drugs like repaglinide (REP) and the SUs. Earlier studies on the kinetics, glucose-dependence and sensitivity to metabolic inhibitors of the interaction between NAT and K(ATP) channels suggested a distinct signaling pathways with NAT compared to REP, glyburide (GLY) or glimepiride (GLI). To obtain further evidence for this concept, the present study compared the insulin secretion in vitro from rat islets stimulated acutely by NAT, GLY, GLI or REP at equipotent concentrations during 1-hr static incubation following overnight treatment with GLY or tolbutamide (TOL). The islets fully retained the responsiveness to NAT stimulation after prolonged pretreatment with both SUs, while their acute response to REP, GLY, and GLI was markedly attenuated, confirming the desensitization of islets. The insulinotropic efficacy of NAT in islets desensitized to SUs may result from a distinct receptor/effector mechanism, which contributes to the unique pharmacological profile of NAT.

Animals↗
PubMed2001

Effects of retention intervals on the magnitude of optokinetic rotation-induced taste aversions.

This study investigated the effects of different retention intervals on the magnitude of optokinetic rotation-induced conditioned taste aversions in humans. Two experiments were conducted. In Exp. 1, 20 subjects were divided into two groups, a CS-UCS group in which drinking soybean milk was paired with optokinetic rotation-induced gastric illness and a CS-Only group in which drinking soybean milk was not paired with optokinetic rotation. Analysis indicated that two days after pairing soybean milk drinking with optokinetic rotation, the subjects in the CS-UCS group had significantly reduced palatability ratings of soybean milk and lower consumption of soybean milk than those in the CS-Only group. In Exp. 2, 40 subjects were divided into four CS-UCS groups with 1-day, 3-day, 5 day, and 10-day retention intervals between the session of pairing soybean milk with optokinetic rotation and the session of retasting soybean milk. Analysis yielded no significant differences among four groups on palatability of soybean milk and consumption of soybean milk in the retasting session. It is concluded that optokinetic rotation is an effective unconditioned stimulus for conditioned taste aversions formation and that the aversion has a retention period of at least 10 days.

Avoidance Learning↗
PubMed2001

Susceptibility to motion sickness induced by optokinetic rotation and self-rotation by walking around a vertical pole.

31 subjects viewed an optokinetic rotating drum for 12 min. in one session and self-rotated by walking quickly around a vertical pole with eyes closed while alternately flexing and extending the neck in another session. The self-rotation session contained 6 trials (3 clockwise and 3 counterclockwise rotations). Each trial contained 20 cycles of self-rotations. Self-reported ratings of nausea and symptoms of motion sickness were obtained for each session. The subjects developed symptoms of nausea, sweating, dizziness, headache, drowsiness, and changes in salivation in both drum rotation and self-rotation sessions. However, the subjects reported higher ratings of nausea in the session of optokinetic rotation than in the session of self-rotation around a vertical pole. These results indicated that both optokinetic rotation and self-rotation with eyes closed while alternately flexing and extending the neck are effective means of inducing nausea and motion sickness.

Adolescent↗
PubMed2001

A common mechanism for cystic fibrosis transmembrane conductance regulator protein activation by genistein and benzimidazolone analogs.

We have investigated the mechanism of action of two benzimidazolone analogs (NS004 and NS1619) on DeltaF508-CFTR using both whole-cell and cell-attached patch-clamp techniques and compared their effects with those of genistein. We conclude that benzimidazolone analogs and genistein act through a common mechanism, based on the following evidence: 1) both act only on phosphorylated CFTR, 2) the maximal DeltaF508-CFTR current activated by benzimidazolone analogs is identical to that induced by genistein, 3) benzimidazolone analogs increase the open probability of the forskolin-dependent DeltaF508-CFTR channel activity through an increase of the channel open time and a decrease of the channel closed time (effects indistinct from those reported for genistein), and 4) the prolonged K1250A-CFTR channel open time (in the presence of 10 microM forskolin) is unaffected by benzimidazolone analogs or genistein, supporting the hypothesis that these compounds stabilize the open state by inhibiting ATP hydrolysis at nucleotide binding domain 2 (NBD2). In addition, we demonstrate that NS004 and NS1619 are more potent CFTR activators than genistein (EC(50) values are 87 +/- 14 nM, 472 +/- 88 nM, and 4.4 +/- 0.5 microM, respectively). From our studies with the double mutant DeltaF508/K1250A-CFTR, we conclude that benzimidazolone analogs and genistein rectify the DeltaF508-CFTR prolonged closed time independent of their effects on channel open time, since these agonists enhance DeltaF508/K1250A-CFTR activity by shortening the channel closed time. These studies should pave the way toward understanding the agonist binding sites at a molecular level.

3T3 Cells↗
PubMed2001

"Hybrid" revascularization: video-thoracoscopy assisted MIDCAB combined with angioplasty.

A "hybrid" revascularization technique has been developed for cases in which a chronic total occlusion of the left anterior descending coronary artery (LAD) cannot be recanalized by percutaneous coronary intervention, but the lesions in the right coronary artery and/or left circumflex artery are very good candidates for angioplasty. This technique, which uses video-thoracoscopy assisted minimally invasive direct coronary artery bypass to recanalize the occluded LAD and angioplasty to dilate favorable lesions in other vessels, would achieve complete revascularization in selected patients with multi-vessel disease. In this preliminary study of four patients, angioplasty and stenting were successful in all patients without any complications; complete revascularization was achieved in all 4 patients. No recurrence of angina and no cardiovascular events developed during follow-up; this study therefore supports the belief that the "hybrid" revascularization technique is both feasible and safe.

Adult↗
PubMed2001

[The relationship between the mutation of methylenetetrahydrofolate reductase gene 677C-->T and the diabetic microangiopathy].

OBJECTIVE: To investigate the relationship between the mutation of methylenetetra- hydrofolate reductase gene 677C-->T and the diabetic microangiopathy(DMA) in diabetes mellitus(DM). METHODS: A total of 168 subjects were divided into control group, DM group and DMA group(including diabetic nephropathy and diabetic retinopathy). PCR-restrictive fragment length polymorphism(RFLP) analysis was conducted to examine mutation, and then the frequency of mutation was statistically computed. RESULTS: Markedly elevated mutation was observed in patients with diabetic nephropathy and diabetic retinopathy as compared with non-microangiopathy diabetes mellitus and normal people (20.8% vs 8.3% and 7.3%, P<0.01). The odds ratio of the TT genotype for DMA was 3.36, P<0.001. CONCLUSION: It was found that the mutation of methylenetetrahydrofolate reductase gene 677C-->T was an impressibility factor of diabetic microangiopathy.

Adult↗
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

[Design and implementation of mini PACS in the hospital].

This paper introduces the principle and classification of picture archiving and communication system (PACS) and some pertinent technologies, including the capture methods of pictures data, images storage equipment and the choice of medium, and the network of images transmission. Also presented is an analysis of the merit and demerit of different kinds of PACS, and in the end we put forward a PACS design method and network framework based on practical implication in the Jinwei project experimental hospital.

Computer Communication Networks↗
PubMed2001

Growth inhibition of epidermal growth factor-stimulated human glioblastoma cells by nicardipine in vitro.

BACKGROUND: The objective of this work was to observe and analyze the effects of epidermal growth factor (EGF) and the calcium channel antagonist nicardipine on the growth of U251MG, a human malignant glioma cell line, which have high-affinity EGF receptors. METHODS: The growth effects of EGF and nicardipine on U251MG cultured in serum-free and serum-supplemented (10% fetal bovine serum, FBS) medium respectively were observed by MTT colorimeritric analysis. RESULTS: EGF significantly enhanced the growth of U251MG cells in a dose-dependent manner in serum-free medium. The maximal effect was seen at 20 ng/ml. The effects of EGF approximated those obtained in 10% FBS. Nicardipine decreased U251MG cell proliferation, especially in serum-supplemented medium, and completely blocked the growth-stimulated effects of EGF. The combined effects of EGF (10 ng/ml) and nicardipine equaled those of nicardipine alone. CONCLUSIONS: When serum was absent, the U251MG cells showed a pronounced mitogenic response to EGF in a dose-dependent manner, which approximated that achieved with 10% FBS. The addition of serum obscured this effect. Nicardipine suppressed the growth of U251MG cells and completely blocked the growth-stimulated effects of EGF may suggest a possible role of this drug as adjuvant therapy for human malignant gliomas.

Calcium Channel Blockers↗
PubMed2001

[History of the grafting of coronary artery bypass].

Great efforts had been made to treat coronary artery disease by using myocardial revascularization for a century. Evolved from the early exploration, and the early forms of direct revascularization. The grafting of coronary artery bypass began in the 1960s. Big progresses had been made in the operative technique, the grafting materials of bypass and myocardial protection etc. in the following forty years. Now it is one of the most effective therapies for coronary artery disease.

Coronary Artery Bypass↗
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↗