Biomedical subjects

Z Sun

Publications and source records attributed to Z Sun.

At least 55 records · Page 3Linked to original sources

PubMed2001

Single-molecule magnets: Jahn-Teller isomerism and the origin of two magnetization relaxation processes in Mn12 complexes.

Several single-molecule magnets with the composition [Mn12O12(O2CR)16(H2O)x] (x = 3 or 4) exhibit two out-of-phase ac magnetic susceptibility signals, one in the 4-7 K region and the other in the 2-3 K region. New Mn12 complexes were prepared and structurally characterized, and the origin of the two magnetization relaxation processes was systematically examined. Different crystallographic forms of a Mn12 complex with a given R substituent exist where the two forms have different compositions of solvent molecules of crystallization and this results in two different arrangements of bound H2O and carboxylate ligands for the two crystallographically different forms with the same R substituent. The X-ray structure of cubic crystals of [Mn12O12(O2CEt)16(H2O)3]. 4H2O (space group P1) (complex 2a) has been reported previously. The more prevalent needle-form of [Mn12O12(O2CEt)16(H2O)3] (complex 2b) crystallizes in the monoclinic space group P2(1)/c, which at -170 degrees C has a = 16.462(7) A, b = 22.401(9) A, c = 20.766(9) A, beta = 103.85(2) degrees, and Z = 4. The arrangements of H2O and carboxylate ligands on the Mn12 molecule are different in the two crystal forms. The complex [Mn12O12-(O2)CC6H4-p-Cl)16(H2O)4].8CH2Cl2 (5) crystallizes in the monoclinic space group C2/c, which at -172 degrees C has a = 29.697(9) A, b = 17.708(4) A, c = 30.204(8) A, beta = 102.12(2) degrees, and Z = 4. The ac susceptibility data for complex 5 show that it has out-of-phase signals in both the 2-3 K and the 4-7 K ranges. X-ray structures are also reported for two isomeric forms of the p-methylbenzoate complex. [Mn12O12(O2CC6H4-p-Me)16(H2O)4]. (HO2CC6H4-p-Me) (6) crystallizes in the monoclinic space group C2/c, which at 193 K has a = 40.4589(5) A, b = 18.2288(2) A, c = 26.5882(4) A, beta = 125.8359(2) degrees, and Z = 4. [Mn12O12(O2CC6H4-p-Me)16(H2O)4].3(H2O) (7) crystallizes in the monoclinic space group I2/a, which at 223 K has a = 29.2794(4) A, b = 32.2371(4) A, c = 29.8738(6) A, beta = 99.2650(10) degrees, and Z = 8. The Mn12 molecules in complexes 6 and 7 differ in their arrangements of the four bound H2O ligands. Complex 6 exhibits an out-of-phase ac peak (chi(M)' ') in the 2-3 K region, whereas the hydrate complex 7 has a chi(M)' ' signal in the 4-7 K region. In addition, however, in complex 6, one Mn(III) ion has an abnormal Jahn-Teller distortion axis oriented at an oxide ion, and thus 6 and 7 are Jahn-Teller isomers. This reduces the symmetry of the core of complex 6 compared with complex 7. Thus, complex 6 likely has a larger tunneling matrix element and this explains why this complex shows a chi(M)' ' signal in the 2-3 K region, whereas complex 7 has its chi(M)' ' peak in the 4-7 K region, i.e., the rate of tunneling of magnetization is greater in complex 6 than complex 7. Detailed 1H NMR experiments (2-D COSY and TOCSY) lead to the assignment of all proton resonances for the benzoate and p-methyl-benzoate Mn12 complexes and confirm the structural integrity of the (Mn12O12) complexes upon dissolution. In solution there is rapid ligand exchange and no evidence for the different isomeric forms of Mn12 complexes seen in the solid state.

Journal Article↗

PubMed2001

Low birth weight, developmental milestones, and behavioral problems in Chinese children and adolescents.

This study examined the association of low birth weight (LBW) and developmental milestones with behavioral and emotional problems in a general population sample of 3344 Chinese children and adolescents aged 6-16 years in 1997. Parents completed a self-administrated questionnaire including information about birth weight and developmental milestones (i.e. lifting the head up, tooth eruption, speech, walking and bedwetting cessation), and the Child Behavioral Checklist (CBCL). Teachers completed the Teacher's Report Form (TRF) to assess classroom behavior problems. Results indicated that LBW and delayed developmental milestones were significantly associated with an increased risk for almost all parent- and teacher-reported behavioral problems after controlling for the potential effects of child's gender, age and birth order, parental ages at birth, education, occupation, complications at birth and number of children in the family. LBW was significantly associated with delay in achieving all developmental milestones including lifting of the head, tooth eruption, sitting without support, walking without help, speech as saying words with meaning, and bedwetting cessation. It is concluded that LBW and delayed early childhood development may predict the occurrence of a wide range of behavioral and emotional problems in later childhood and adolescence.

Adolescent↗

PubMed2001

Regional characteristics of sulfur and lead isotope ratios in the atmosphere at several Chinese urban sites.

Sulfur and lead isotope ratios in the atmosphere were measured at several selected sites (Harbin, Changchun, Dalian, Waliguan, Shanghai, Nanjing, Guiyang) in China and Tsukuba (Japan), to reveal regional sources characteristics over Eastern Asia. Average S isotope ratios for SO2 and sulfate in the atmosphere in China were close to those of the coals used in each region, indicating a considerable contribution of coal combustion to the sulfur compounds in the atmosphere. Most northern cities had around 5% sulfur isotope ratio, while Guiyang, a southwestern city in China, showed a considerably lower sulfur isotope ratio (about -3%) because of the unusually light sulfur isotope ratio of coals in this region. These were considerably different from the value (-1.4%) for Tsukuba (Japan). Lead isotope ratios also suggested that coal combustion considerably contributed to atmospheric lead in some cases in China. At the same time, influences by the emission of Chinese lead ores were also observed in northern cities. Seasonal variations of both sulfur and lead isotope ratios indicated the existence of a certain amount of industrial sources other than coal combustion. In addition, fractionation effect between SO2 and sulfate showed a seasonal tendency (high in winter (0-6%) and low in summer (-1-3%)), suggesting the oxidation pathway of SO2 changed seasonally.

Air Pollution↗

PubMed2001

SMAD3 represses androgen receptor-mediated transcription.

The androgen-signaling pathway is important in the growth and progression of prostate cancer. Androgen ablation therapy, which may result in programmed cell death, is often used to treat advanced prostate cancer. The growth-promoting effects of androgen are mediated mostly through the androgen receptor (AR). Transforming growth factor beta (TGF-beta) plays critical roles in controlling prostate cell proliferation, differentiation, and apoptosis. Normal transcripts and proteins of TGF-beta receptors are frequently lost in prostate cancer cells, especially in advanced stages of the disease. However, the mechanisms by which TGF-beta inhibits proliferation and induces apoptosis in prostate cancer cells is not clear. We investigated the molecular mechanism by which TGF-beta inhibits transcriptional activation mediated by AR. Using transient transfection systems, we demonstrated that Smad3 specifically represses transcriptional activation mediated by AR on two natural androgen-responsive promoters. This repression is transmitted through TGF-beta signaling and can be regulated by other Smad proteins. A protein-protein interaction between AR and Smad3 was identified in vitro and in vivo, and the transcription activation domain of AR and the MH2 of Smad3 were identified as being responsible for binding. Additional functional experiments showed that the repression of AR by Smad3 is mediated solely through the MH2 domain. These results provide fresh insight for understanding the mechanism by which TGF-beta regulates the androgen-signaling pathway in prostate cancer cells.

Androgen Receptor Antagonists↗

PubMed2001

Androgen receptor specifically interacts with a novel p21-activated kinase, PAK6.

The androgen receptor (AR) is a hormone-dependent transcription factor that plays important roles in male sexual differentiation and development. Transcription activation by steroid hormone receptors, such as the androgen receptor, is mediated through interaction with cofactors. We recently identified a novel AR-interacting protein, provisionally termed PAK6, that shares a high degree of sequence similarity with p21-activated kinases (PAKs). PAK6 is a 75-kDa protein that contains a putative amino-terminal Cdc42/Rac interactive binding motif and a carboxyl-terminal kinase domain. A domain-specific and ligand-dependent interaction between AR and PAK6 was further confirmed in vivo and in vitro. Northern blot analysis revealed that PAK6 is highly expressed in testis and prostate tissues. Most importantly, immunofluorescence studies showed that PAK6 cotranslocates into the nucleus with AR in response to androgen. Transient transfection experiments showed that PAK6 specifically repressed AR-mediated transcription. This report identifies a novel function for a PAK-homologous protein and suggests a potential unique mechanism by which other signal transduction pathways may cross-talk with AR pathways to regulate AR function in normal and malignant prostate cells.

Amino Acid Sequence↗

PubMed2001

alpha-lactalbumin mutant acting as lysozyme.

A mutant of alpha-lactalbumin was expressed and purified, in which His32, Thr33, Glu49, Ile59, Val99, and Tyr103 were substituted by Leu32, Glu33, Asp49, Trp59, Asn99, and Ala103, respectively, to create a catalytic site of lysozyme in alpha-lactalbumin. The mutant catalyzed hydrolysis of the synthetic substrate, pNP-(NAcGlc)(3), with a K(M) and k(cat) of 0.160 +/- 0.00986 mmol/L and 3.39 +/- 0. 0456 x10(-5) min(-1), respectively, which was comparable with those of chicken lysozyme of 0.137 +/- 0.0153 mmol/L and 5.25 +/- 0.115 x10(-4) min(-1). By using the Isothermal Titration Calorimetre (ITC), the average binding enthalpy of the mutant or chicken lysozyme with the substrate (chitopentaose) was measured, which was 49.22 KJ/mol for the mutant and 105.47 KJ/mol for chicken lysozyme. In conclusion, the six point mutations occurring in alpha-lactalbumin could be converted into an enzyme that was 17.5-fold less efficient than chicken lysozyme but nevertheless capable of hydrolyzing the glycosidic bond.

Amino Acid Sequence↗

PubMed2001

Total cavopulmonary connection for complex cardiac anomalies with the functional single ventricle.

From Aug. 1999 to Feb. 2001, 8 patients with complex congenital heart diseases, including 5 cases accompanied by hypoplastic left ventricle and 3 by hypoplastic right ventricle, were subjected to total cavopulmonary connection (TCPC). Eight cases underwent the operation under cardiopulmonary bypass and 7 of whom under no cardiac clamp. Seven cases received cavopulmonary anastomosis by flaring method and one case by end-side anastomosis. All the patients underwent the intracardiac tunnels to drain inferior vena cava and plus 4 mm fenestration except one. The results showed that 6 patients had postoperative oxygen saturation more than 90%, sinus rhythm, no anastomostic stoma obstruction, no flow regurgitation and CVP < 16 cmH2O. Two (25%) patients died postoperatively from high venous pressure of 18-20 cmH2O, finally from cardiac failure and anoxima. It was concluded that TCPC was an effective treatment for complex congenital cardiac diseases, especially with ventricular maldevelopment. Intracardiac tunnel plus 4 mm fenestration and flaring cavopulmonary anastomosis could prevent the postoperative complications. Larger anastomotic stoma, venous pressure less than 16 cmH2O and artery saturation more than 90% might indicate excellent TCPC procedures in our experience.

Child↗

PubMed2001

Human apolipoprotein A-IV metabolism within triglyceride-rich lipoproteins and plasma.

In order to investigate the metabolism of apo A-IV within TRL and plasma, we assessed TRL and plasma apo A-IV kinetics in 19 and 4 subjects, respectively, consuming an average US diet for a 6-week period. At the end of this diet study, each subject received a primed-constant infusion of deuterated leucine over a 15 h time period with hourly feeding, and blood samples were drawn at 10 time points. TRL was separated by ultracentrifugation. Apo A-IV was isolated by immunoprecipitation and/or SDS-PAGE. Apo A-IV concentrations were determined by immunoelectrophoresis. Stable isotope tracer/tracee ratios were measured by gas chromatography/mass spectrometry, and the data were analyzed by multicompartmental modeling. The mean concentrations of plasma and TRL apo A-IV during the isotope infusion period were 21.0+/-3.2 and 0.66+/-0.25 mg/dl, respectively, and these values were 11.5 and 30.5% higher than those of fasting samples. The mean TRL and plasma apo A-IV residence times (RT) were 1.97+/-0.57 and 2.71+/-0.65 days, and transport rates (TR) were 0.17+/-0.19 and 3.90+/-1.24 mg/kg per day, respectively. There were significant correlations between TRL apo A-IV concentrations and TR (r(2)=0.79, P<0.001), and between TRL apo A-IV pool size and TRL cholesterol levels (r(2)=0.29, P=0.02). Our data indicated that; (1) TRL apo A-IV has a RT of 1.97 days which is similar to that earlier reported for HDL apo A-IV; (2) Apo A-IV recirculates between TRL and other slowly turning over pools; (3) the primary determinant of TRL apo A-IV levels is its TR; and (4) there is no correlation between TRL apo A-IV and apo B48 fractional catabolism in TRL.

Adult↗

PubMed2001

Clad polymer buffer rods for polymer process monitoring.

Clad polymer buffer rods consisting of a polyetheretherketone (PEEK) core and a cladding made of a heat resistance epoxy aluminum composite are presented. The core has a uniform diameter or a taper shape. Ultrasonic measurement results indicate that the ultrasonic signal strength and signal to noise ratio of these clad rods are better than those of the non-clad PEEK rods for both longitudinal and shear waves because of the improved ultrasonic wave guidance in the core. Comparisons of these rods with those made of polymide and high-density polyethylene are given. Applications of these buffer rods for ultrasonic monitoring of polymer extrusion at temperatures up to 200 degrees C and pressures up to 180 psi are demonstrated. The monitoring results also reveal that within certain operating temperature and pressure range, clad polymer buffer rods show advantages over clad steel buffer rods.

Benzophenones↗

PubMed2001

Determination of active component in silymarin by RP-LC and LC/MS.

Silybin, isosilybin, silydianin and silycristin in silymarin were separated and quantitatively determined by RP-HPLC. Two diastereoisomers of silybin and isosilybin were respectively separated by RP-HPLC and confirmed by LC/MS. Chromatographic condition consisted of column: Shim-pack VP-ODS (150 x 4.6mm i.d. 5 microm) and Pre-column (10 x 4.6 mm i.d. 5 microm); mobile phase: methanol and solvent mixture (water: dioxane=9:1) by gradient; flow rate: 1.5ml/min; column temp.: 40 degrees C; detector wavelength: 288 nm; The recovery of 99.66% for silycristin, 99.48% for silydianin, 100.0% for silybin and 98.72% for isosilybin was respectively obtained.

Antioxidants↗

PubMed2001

The strawberry FaMYB1 transcription factor suppresses anthocyanin and flavonol accumulation in transgenic tobacco.

Fruit ripening is characterized by dramatic changes in gene expression, enzymatic activities and metabolism. Although the process of ripening has been studied extensively, we still lack valuable information on how the numerous metabolic pathways are regulated and co-ordinated. In this paper we describe the characterization of FaMYB1, a ripening regulated strawberry gene member of the MYB family of transcription factors. Flowers of transgenic tobacco lines overexpressing FaMYB1 showed a severe reduction in pigmentation. A reduction in the level of cyanidin 3-rutinoside (an anthocyanin) and of quercetin-glycosides (flavonols) was observed. Expression of late flavonoid biosynthesis genes and their enzyme activities were adversely affected by FaMYB1 overexpression. Two-hybrid assays in yeast showed that FaMYB1 could interact with other known anthocyanin regulators, but it does not act as a transcriptional activator. Interestingly, the C-terminus of FaMYB1 contains the motif pdLNL(D)/(E)Lxi(G)/S. This motif is contained in a region recently proposed to be involved in the repression of transcription by AtMYB4, an Arabidopsis MYB protein. Our results suggest that FaMYB1 may play a key role in regulating the biosynthesis of anthocyanins and flavonols in strawberry. It may act to repress transcription in order to balance the levels of anthocyanin pigments produced at the latter stages of strawberry fruit maturation, and/or to regulate metabolite levels in various branches of the flavonoid biosynthetic pathway.

Amino Acid Sequence↗

PubMed2001

Activation of MKK6, an upstream activator of p38, in Alzheimer's disease.

Mitogen-activated protein kinase (MAPK) p38 has been implicated in the pathogenesis of Alzheimer's disease, but the upstream cascade leading to p38 activation has not been elucidated in the disease. In the present study, we focused on mitogen-activated protein kinase kinase 6 (MKK6), one of the upstream activators of p38 MAPK. We found that MKK6 was not only increased but also specifically associated with granular structures in the susceptible neurons in the hippocampus and cortex of Alzheimer's disease patients, but was only weakly diffuse in the cytoplasm in neurons in control cases. Immunoblot analysis demonstrated a significant increase of MKK6 level in Alzheimer's disease compared with age-matched controls. In this regard, in hippocampal and cortical regions of individuals with Alzheimer's disease, the activated phospho-MKK6 was localized exclusively in association with pathological alterations including neurofibrillary tangles, senile plaques, neuropil threads and granular structures, overlapping with activated p38 MAPK suggesting both a functional and mechanic link. By immunoblot analysis, phospho-MKK6 is also significantly increased in AD compared with control cases. Together, these findings lend further credence to the notion that the p38 MAPK pathway is dysregulated in Alzheimer's disease and also indicates an active role for this pathway in disease pathogenesis.

Adolescent↗

PubMed2001

Effects of inhibition of PAF, ICAM-1 and PECAM-1 on gut barrier failure caused by intestinal ischemia and reperfusion.

BACKGROUND: The role of cell adhesion molecules and transmigration of PMNs through the endothelial barrier is probably essential in intestinal ischemia and reperfusion (I/R)-induced gut barrier dysfunction. Although cytokines are released in I/R, it is unclear whether cytokines directly increase permeability or if this phenomenon requires both expression of cell adhesion molecules and PMN adhesion-activation. Endothelial barrier dysfunction plays an important role in the pathogenesis of multiple organ dysfunction syndrome, inducing gut barrier failure, but the mechanisms are not fully understood. The purpose of this study was to evaluate the potential therapeutic value of inhibition of platelet activating factor (PAF), intercellular adhesion molecule-1 (ICAM-1), and platelet endothelial cell adhesion molecule-1 (PECAM-1) in gut barrier dysfunction induced by intestinal I/R. METHODS: A PAF antagonist (lexipafant, BB-882) and monoclonal antibodies against rat ICAM-1 (anti-ICAM-1-MAb) and PECAM-1 (anti-PECAM-1-MAb) were used in a model of gut barrier dysfunction caused by intestinal ischemia for 40 min and concomitant reperfusion for 12 h in the rat, and endothelial permeability, myeloperoxidase activity, interleukin-1beta and protease inhibitor levels were evaluated. RESULTS: The endothelial permeability and tissue leukocyte recruitment in the distal small intestine significantly increased in rats with I/R treated with saline. Proteolytic activity in plasma was evident by low levels of the three measured plasma protease inhibitors. These changes were, to different degrees, reduced by treatment with lexipafant, anti-ICAM-1-MAb, or anti-PECAM-1-MAb. Alterations in systemic levels of interleukin-1beta paralleled the changes found in gut barrier permeability and leukocyte trapping. CONCLUSIONS: Our results suggest that treatment with the PAF inhibitor lexipafant and monoclonal antibodies against ICAM-1 or, seemingly most efficient, PECAM-1 reduces the severity of I/R-associated intestinal dysfunction, associated with a decrease in systemic concentrations of IL-1beta local leukocyte recruitment, and partly restoring plasma protease inhibitor levels.

Animals↗

PubMed2001

Effects of a National Cholesterol Education Program Step II Diet on apolipoprotein A-IV metabolism within triacylglycerol-rich lipoproteins and plasma.

BACKGROUND: Apolipoprotein (apo) A-IV is a major component of triacylglycerol-rich lipoprotein (TRL) apolipoproteins. OBJECTIVE: We investigated the effects of dietary saturated fat and cholesterol restriction on the metabolism of TRL and plasma apo A-IV. DESIGN: We assessed TRL and plasma apo A-IV kinetics in 16 and 4 subjects, respectively, consuming an average US (baseline) diet for 6 wk and a National Cholesterol Education Program Step II diet for 24 wk, respectively. At the end of each diet period, all subjects received a primed, constant infusion of deuterated leucine for 15 h with hourly feeding. Ratios of stable-isotope tracer to tracee were measured by using gas chromatography-mass spectrometry, and kinetic data were modeled by using SAAM II. RESULTS: Mean apo A-IV concentrations during the isotope infusion period were 6.9 +/- 2.6 mg/L in TRL and 2.2 +/- 3.2 mg/L in plasma with the baseline diet; these values were 37.7% (P < 0.001) and 19.4% (P < 0.01) lower with the Step II diet. Similar changes were observed in the fasting state between the 2 diets. The mean apo A-IV secretion rate decreased significantly from baseline by 59.6% in TRLs and by 40.2% in plasma. Significant correlations were observed between TRL apo A-IV concentrations and the secretion rate (r = 0.94, P < 0.001) and between TRL apo A-IV pool size and TRL-cholesterol concentrations (r = 0.48, P < 0.01). CONCLUSIONS: Our data indicate that the National Cholesterol Education Program Step II diet significantly decreases TRL and plasma apo A-IV concentrations compared with the average US diet and that this decrease is due to a decreased secretion rate.

Adult↗

PubMed2001

Support vector machine approach for protein subcellular localization prediction.

MOTIVATION: Subcellular localization is a key functional characteristic of proteins. A fully automatic and reliable prediction system for protein subcellular localization is needed, especially for the analysis of large-scale genome sequences. RESULTS: In this paper, Support Vector Machine has been introduced to predict the subcellular localization of proteins from their amino acid compositions. The total prediction accuracies reach 91.4% for three subcellular locations in prokaryotic organisms and 79.4% for four locations in eukaryotic organisms. Predictions by our approach are robust to errors in the protein N-terminal sequences. This new approach provides superior prediction performance compared with existing algorithms based on amino acid composition and can be a complementary method to other existing methods based on sorting signals. AVAILABILITY: A web server implementing the prediction method is available at http://www.bioinfo.tsinghua.edu.cn/SubLoc/. SUPPLEMENTARY INFORMATION: Supplementary material is available at http://www.bioinfo.tsinghua.edu.cn/SubLoc/.

Amino Acid Sequence↗

PubMed2001

Behavioral and emotional problems in Chinese adolescents: parent and teacher reports.

OBJECTIVE: This study examined behavioral and emotional problems in Chinese adolescents. METHOD: A sample of 1,694 adolescents aged 12 to 16 years participated in this study in 1997. Parents completed the Child Behavior Checklist (CBCL), and teachers completed the Teacher's Report Form (TRF). RESULTS: For both parent and teacher reports, internalizing syndromes were scored higher in girls and externalizing syndromes were scored higher in boys. Scores on most of the CBCL and TRF subscales were higher for the older adolescents. The overall prevalence rates of parent- and teacher-reported behavioral problems were 23.1% and 19.2%, respectively. The eight cross-informant syndromes were highly comorbid, with a significant association across syndromes (mean odds ratio = 16.1 for CBCL and 22.5 for TRF). Correlations between parent and teacher reports were 0.51 for eight subscales and 0.68 for Total Problems. CONCLUSIONS: These findings demonstrate that behavioral and emotional problems tend to increase with age and cluster in the same individuals. The prevalence rates of behavioral problems in Chinese adolescents are comparable to those reported in Western countries. In contrast to findings for Western samples, parent reports of behavioral problems were highly correlated with teacher reports.

Adolescent↗

PubMed2001

A noninvasive cross-correlation ultrasound technique for detecting spatial profile of laser-induced coagulation damage--an in vitro study.

A cross-correlation A-mode ultrasound technique is proposed for noninvasively detecting the spatial profile of coagulation damage in tissue being irradiated by laser. The basic assumption underlying this technique is that when coagulation is taking place in a tissue region, owing to thermally-induced structure changes in tissue, the waveform of echo signal scattered from that region should be changing accordingly. Our technique consists of four steps: 1) repeatedly sending the same acoustic signal to the tissue being heated; 2) tracking echo signals scattered from many small tissue regions using a cross-correlation echo-tracking technique; 3) quantifying waveform change of echo signal scattered from each region by means of cross-correlation coefficient between the currently acquired signal and a reference signal; 4) using the spatial profile of the degree of the waveform change to represent the tissue coagulation status at different depths. We carried out 23 heating experiments on fresh canine liver samples using a Nd:YAG laser (1,064 nm wavelength) at various light intensity (62 to 105 W/cm2) and exposure time (20 to 350 s). A 13-mm-diameter 10-MHz broadband single-element spherical focused ultrasound transducer was used. The spatial profiles of the degree of coagulation damage in the heated tissues, as determined by our technique, qualitatively agreed with the grossly inspected results. They also appeared to be consistent with the experimental and theoretical findings in the literature on laser-tissue interaction. Moreover, we developed an automatic procedure to compute the coagulation depth using the spatial profiles of the waveform change. We used the result as an indirect but quantitative means for evaluating the technique. Good overall agreement with a root mean square (rms) difference of only 0.81 mm was obtained between the computed and visually inspected final coagulation depths for the 23 experiments.

Animals↗

PubMed2001

Surgical treatment of intractable epilepsy combined with bipolar electrocoagulation on functional cortex.

OBJECTIVE: Resecting epileptogenic foci combined with bipolar electrocoagulation of functional cortex has been successfully used to treat intractable epilepsy. METHOD: 124 cases with intractable epilepsy have been treated from 1996 to 1999, 75 cases with temporal lobe epilepsy and 48 cases with extra-temporal lobe epilepsy, and one case with infantile hemiplegia. Electrocorticography (ECoG) was used pre- and postoperatively. 108 cases were followed-up from one to three years. RESULTS: The general efficiency of bipolar electrocoagulation on functional cortex (BCFC) for epilepsy is 91.7%. The pathological features indicate that the damage by coagulation of the cortex is only in the supra- and infra-granular layers, similar to multiple subpial transection (MST). CONCLUSION: When the epileptogenic foci are located in functional cortex, the method of resecting the foci combined with BCFC has been effective and improves the results greatly. BCFC is safe and easy to use.

Adolescent↗