Prediction of postoperative pain intensity after lumbar spinal surgery using pain sensitivity and preoperative back pain severity.

OBJECTIVES: To investigate the role of preoperative pain sensitivity and preoperative symptom severity for prediction of postoperative pain intensity after lumbar spine surgery. METHODS: This study consisted of two groups who underwent decompression surgery alone (62 patients) or decompression with fusion surgery (37 patients) for lumbar spinal stenosis (LSS). Pain Sensitivity Questionnaire (PSQ) and visual analog pain scale (VAS) for back pain and leg pain were collected preoperatively with detailed medical history. The assessment was performed immediately after surgery when the patients had completely recovered and regained their complete consciousness from general anesthesia (H0) and subsequently 4, 8, 18, 30, 48, and 72 hours (H4, H8, H18, H30, H48, and H72) thereafter as they recovered. RESULTS: Both groups showed a decrease in back pain and leg pain with the time postoperatively. In fusion group, preoperative VAS for back pain was significantly correlated with postoperative VAS for back pain at H0, H4, H8, and H18, and PSQ minor/total PSQ also showed a significant correlation with postoperative back pain at H48 and H72. In contrast, only total PSQ and PSQ minors were significantly correlated with postoperative back pain at H18 and H30 in decompression group. Hierarchical regression analysis finally showed that each preoperative back pain and PSQ minor was predictive of immediate postoperative back pain (from H0 to H18) in fusion group and delayed postoperative back pain (H18, H30) in decompression group. CONCLUSIONS: The study highlights that each preoperative back pain and individual pain sensitivity could predict the different aspects of postoperative pain after lumbar surgery.

Fabrication of a pure, uniform electroless silver film using ultrafine silver aerosol particles.

To obtain evenly distributed pure Ag particles with a narrow size distribution on a polymer membrane, a novel activation procedure with an environmentally friendly, cost-effective method was utilized as a pretreatment before electroless Ag deposition. The pretreatment was first performed on an untreated membrane surface by collecting ultrafine ambient spark-generated Ag aerosol particles. After annealing, the electroless Ag film was fabricated on the collected aerosol particles in the Ag electroless bath. Experimental characterizations showed that the ultrafine Ag particles were uniformly anchored onto the membrane surface through pretreatment, resulting in a pure Ag film of closely packed particles with a narrow size distribution on the membrane, and the properties were comparable to those of an Ag film on wet Sn-Ag-activated membranes.

Nonverbal memory dysfunction in obsessive-compulsive disorder patients with checking compulsions.

Obsessive-compulsive disorder (OCD) is a clinically heterogeneous disorder; nonetheless, most of the previous neuropsychological studies for assessing the involvement of memory dysfunction grouped together patients with different symptoms, thereby potentially accounting for the inconsistencies of results. The goals of this study were to compare the memory dysfunction of two main subtypes of OCD and to identify the type of memory dysfunction that is associated with the checking symptoms in OCD patients. The sample population comprised the cleaning-type OCD group (N=23), checking-type OCD group (N=24), and a control group of healthy volunteers (N=20). All the OCD patients were selected from the outpatient clinic. All the subjects underwent the Rey-Osterreith Complex Figure Test (RCFT) for the assessment of nonverbal memory function, the Hopkins Verbal Learning Test (HVLT) for verbal memory function, the Wechsler Adult Intelligence Scale-Revised (WAIS-R), and the Wisconsin Card Sorting Test (WCST). The immediate and delayed memory scores of RCFT were significantly lower in the checking-type OCD group; there were no significant differences in HVLT scores amongst the three groups. Our results indicate that the checking-type compulsion of OCD patients is associated with nonverbal memory deficits and not with verbal memory deficits.

Sexually dimorphic effects of four genes (COMT, SLC6A2, MAOA, SLC6A4) in genetic associations of ADHD: a preliminary study.

A growing body of literature finds gender differences in ADHD. However, little is known about the causes of these differences. One possibility is that ADHD risk genes have sexually dimorphic effects. We have investigated four ADHD candidate genes (COMT, SLC6A2, MAOA, SLC6A4) for which there is evidence of sexually dimorphic effects. Past neurobiological and genetic studies suggest that COMT, and SLC6A4 variants may have a greater influence on males and that SLC6A2, and MAOA variants may have a greater influence on females. Our results indicate that genetic associations are stronger when stratified by sex and in the same direction as the previous neurobiological studies indicate: associations were stronger in males for COMT, SLC6A4 and stronger in females for SLC6A2, MAOA. Moreover, we found a statistically significant gender effect in the case of COMT (P = 0.007) when we pooled our work with a prior study. In conclusion, we have found some evidence suggesting that the genetic association for these genes with ADHD may be influenced by the sex of the affected individual. Although our results are not fully validated yet, they should motivate further investigation of gender effects in ADHD genetic association studies.

Family based association study of pediatric bipolar disorder and the dopamine transporter gene (SLC6A3).

The dopamine transporter gene (SLC6A3) is a compelling candidate for pediatric bipolar disorder because (a) it has been associated with ADHD, (b) bipolar comorbidity with ADHD has been hypothesized to be an etiologically distinct familial subtype (c) blockade of the dopamine transporter with psychostimulants can induce mania in susceptible individuals and (d) previous studies have implicated the gene in bipolar disorder in adults. We conducted a family-based association study of SLC6A3 in 170 affected offspring trios defined by a child (12.9 +/- 5.3 years of age)with DSM-IV Bipolar-I disorder. Twenty-eight tag SNPs were chosen from the CEU (European) population of the International HapMap project (www.hapmap.org). Results indicated nominally positive association for 4 SNPs (rs40184, rs11133767, rs3776512, and rs464049), but only rs40184 survived correction for multiple statistical comparisons (P = 0.038). This is the first examination of the association with SLC6A3 and bipolar disorder in children and, like previous findings in adults with bipolar disorder, we found evidence of association with SNPs in the 3' region of the gene. These data provide suggestive evidence supporting a role for SLC6A3 in the etiology of pediatric bipolar disorder.

The relationship of anger expression and alexithymia with coronary artery stenosis in patients with coronary artery diseases.

This study examined the relationship between anger expression or alexithymia and coronary artery stenosis in patients with coronary artery diseases. 143 patients with coronary artery diseases (104 males and 39 females) were enrolled in this study. The severity of their coronary artery stenosis was measured by angiography. The Anger Expression Scale and the Toronto Alexithymia Scale were used to assess the level of anger expression and alexithymia. The more stenotic group (occluded by 75% or more) exhibited a significantly higher level of alexithymia than the less stenotic group (occluded by less than 25%). Multiple regression analysis on the extent of stenosis also revealed that regardless of gender and age, the coronary artery disease patients with higher alexithymia were likely to show a greater level of stenosis. However, no significant differences were found on either the anger-in or anger-out subscale scores between the two groups. These results suggest that alexithymia is associated with the severity of coronary artery stenosis in patients with coronary artery disease. However, both anger expression and anger suppression were not shown to be associated with the severity of coronary artery stenosis.

Fabrication of bimetallic nanostructures via aerosol-assisted electroless silver deposition for catalytic CO conversion.

Bimetallic nanostructures were fabricated via aerosol-assisted electroless silver deposition for catalytic CO conversion. An ambient spark discharge was employed to produce nanocatalysts, and the particles were directly deposited on a polytetrafluoroethylene substrate for initiating silver deposition to form Pd-Ag, Pt-Ag, Au-Ag bimetallic nanostructures as well as a pure Ag nanostructure. Kinetics and morphological evolutions in the silver deposition with different nanocatalysts were comparatively studied. The Pt catalyst displayed the highest catalytic activity for electroless silver deposition, followed by the order Pd > Au > Ag. Another catalytic activity of the fabricated bimetallic structures in the carbon monoxide conversion was further evaluated at low-temperature conditions. The bimetallic systems showed significantly higher catalytic activity than that from a pure Ag system.

Aerosol-Processed Thermosensitive Nanocomposites for Controlled Drug Release.

In this study, an ambient-spark-produced iron (Fe)-nanoparticle-laden nitrogen gas was mixed with an atomized solution of N-isopropylacrylamide (NIPAM)-polydimethylsiloxane (PDMS). The Fe nanoparticles reacted with NIPAM-PDMS in the atomized droplets to form encapsulated Fe nanoparticles, i.e., Fe@NIPAM-PDMS nanocomposites, whose size distribution was unimodal (showing only a NIPAM-PDMS-like distribution, with the Fe distribution eliminated). By varying processing temperatures, it was possible to obtain Fe@NIPAM-PDMS nanocomposites with different sizes and morphologies. This is further attributed to the quantitative incorporation of Fe nanoparticles into atomized NIPAM-PDMS-doxorubicin (DOX) droplets. The Fe@NIPAM-PDMS-DOX nanocomposites released different amounts of DOX under a magnetothermal effect, which produced different levels of cytotoxic effects on the targeted HeLa cells. The thermosensitivity makes these nanocomposites an ideal candidate for important applications such as controlled drug delivery.

Biomechanical analysis of fusion segment rigidity upon stress at both the fusion and adjacent segments: a comparison between unilateral and bilateral pedicle screw fixation.

PURPOSE: The purpose of this study was to investigate the effects of unilateral pedicle screw fixation on the fusion segment and the superior adjacent segment after one segment lumbar fusion using validated finite element models. MATERIALS AND METHODS: Four L3-4 fusion models were simulated according to the extent of decompression and the method of pedicle screws fixation in L3-4 lumbar fusion. These models included hemi-laminectomy with bilateral pedicle screw fixation in the L3-4 segment (BF-HL model), total laminectomy with bilateral pedicle screw fixation (BF-TL model), hemi-laminectomy with unilateral pedicle screw fixation (UF-HL model), and total laminectomy with unilateral pedicle screw fixation (UF-TL model). In each scenario, intradiscal pressures, annulus stress, and range of motion at the L2-3 and L3-4 segments were analyzed under flexion, extension, lateral bending, and torsional moments. RESULTS: Under four pure moments, the unilateral fixation leads to a reduction in increment of range of motion at the adjacent segment, but larger motions were noted at the fusion segment (L3-4) in the unilateral fixation (UF-HL and UF-TL) models when compared to bilateral fixation. The maximal von Mises stress showed similar patterns to range of motion at both superior adjacent L2-3 segments and fusion segment. CONCLUSION: The current study suggests that unilateral pedicle screw fixation seems to be unable to afford sufficient biomechanical stability in case of bilateral total laminectomy. Conversely, in the case of hemi-laminectomy, unilateral fixation could be an alternative option, which also has potential benefit to reduce the stress of the adjacent segment.

Aerosol assisted fabrication of carbon nanotube/zinc oxide arrays for a field emission device.

Aerosol deposition of zinc oxide (ZnO) nanoparticles was used to catalyze a silicon substrate site-selectively for a carbon nanotube (CNT) growth. An ambient spark discharge was used to produce aerosol ZnO nanoparticles, and the particle deposition on the substrate through a shadow mask was enhanced by thermophoresis. The ZnO-deposited substrate was then loaded into a chemical vapor deposition chamber, resulting in the formation of CNT/ZnO arrays. The turn-on field of an emission device constructed with the CNT/ZnO arrays was 1.7 V µm(-1) at a current of 2 µA, which was lower than that of the common CNT arrays.

Novel electroless copper deposition on carbon fibers with environmentally friendly processes.

A novel electroless deposition (ELD) of copper (Cu) on carbon fibers (CFs) with environmentally friendly processes, silver (Ag) aerosol activation and subsequent nonformaldehyde Cu ELD, was developed. Spark-generated Ag aerosol nanoparticles (approximately 10 nm in mode diameter) were deposited (48.4 microg Ag/g CF in activation intensity) onto the surfaces of CFs. After annealing (at 220 degrees C in a nitrogen atmosphere), the catalytically activated CFs were placed into a solution for Cu ELD (at 82 degrees C). Homogeneous Cu coating (approximately 5.1 nm/min) on CFs was achieved with 90 min of deposition and the corresponding mass deposition rate and Cu grain size for 30-90 min of deposition had ranges of 0.25-1.14 mg Cu/g CF-min and 14.8-37.2 nm, respectively. The porosity of CFs decreased by depositing the Cu for 30-90 min, and the specific surface area and pore volume of CFs decreased from 1536 to 1399 m(2)/g and from 0.65 to 0.57 cm(3)/g, respectively.

Morphology and structure of aerosol carbon-encapsulated metal nanoparticles from various ambient metal-carbon spark discharges.

The morphology and structure of aerosol carbon encapsulated metal nanoparticles (CEMNs) of various transition metals (anode; Ti, Cu, Zn, Mo, Pd, W, Pt, or Au) formed by ambient spark discharge at the same electrical operating specifications were analyzed. CEMNs were produced with aggregated carbon particles, and their yields and sizes varied according to the metal-to-carbon fraction of each discharge relating to the ionization potential of the electrode material. Each encapsulated metal had natural crystallinity for all discharges, but carbon graphitization for the Mo-C and W-C configurations, which have relatively small differences in melting temperature between the materials, was particularly weak. An empty zone in the carbon shell was also detected in the CEMNs because of the difference in density between the molten and solid phases of the core metal during encapsulation.

Investigation of parent-of-origin effects in ADHD candidate genes.

Attention deficit hyperactivity disorder (ADHD) is a common early-onset childhood disorder with a strong genetic component. Results from previous studies have suggested that there may be a parent-of-origin effect for ADHD candidate genes. In particular, a recent investigation identified a pattern of paternal over-transmission of risk alleles for nine ADHD candidate genes. We examined this phenomenon in a sample of 291 trios for five genes previously associated with ADHD (HTR1B, SNAP-25, DRD5, DAT1, and BDNF). Using a dense map of markers and two analytic methods in this relatively large family-based sample, we do not find any evidence for significant paternal over-transmission of risk alleles in these candidate loci. Thus, we conclude that a substantial parent-of-origin effect is unlikely for these leading ADHD candidate genes.

Variations in the dopamine beta-hydroxylase gene are not associated with the autonomic disorders, pure autonomic failure, or multiple system atrophy.

Norepinephrine (NE) is the major neurotransmitter of the sympathetic division of the autonomic nervous system (ANS). Recent findings of an association between human NE deficiency and variants at the dopamine beta-hydroxylase (DBH) gene [Kim et al., 2002] prompted us to investigate these markers in patients with autonomic disorders; 38 with orthostatic intolerance (OI), 26 with pure autonomic failure (PAF), and 39 with multiple system atrophy (MSA). Eighty-eight normal controls were included in this study. In contrast to NE deficiency, allele frequency and genotype distribution of the genetic variants showed no differences between autonomic disease patients and controls. In addition, no DBH mutation was found that distinguished autonomic disease patients from controls, suggesting that genetic variants of the DBH gene are not associated with the autonomic diseases OI, PAF, and MSA.