bluuebunny/crossref_metadata_2025_split huggingface dataset:
Paraplegia after Tethered Cord Surgery: An Uncommon Combined Anomaly of Spinal Arteriovenous Fistula and Sacral Lipoma— Case Report
Authors: Cheung Arnold C. , Kalkanis Steven N. , Ogilvy Christopher S. 
Published: September 2005

ABSTRACT

OBJECTIVE AND IMPORTANCE:
The coexistence of spinal arteriovenous malformation (AVM) with congenital abnormalities is relatively common. However, the association of a spinal AVM and lipoma is rare. We present an adult patient with this combined anomaly and discuss the clinical relevance of this case.

CLINICAL PRESENTATION:
A 42-year-old Caucasian man with progressive paraparesis initially underwent surgery for a tethered spinal cord. Postoperatively, he became paraplegic. He improved gradually over an interval of 8 months and, at that point, worsened again. Subsequent angiographic study revealed a spinal dural arteriovenous fistula located at S1–S2. Additionally, an occipital dural AVM was discovered near the transverse sinus.

INTERVENTION:
The spinal arteriovenous fistula was excised along with the sacral lipoma. The occipital arteriovenous fistula was embolized successfully at a later time.

CONCLUSION:
The patient had immediate improvement in sensory symptoms after surgery. At a 9 month follow-up examination, he had regained the ability to walk with crutches, but his bladder dysfunction persisted. Recognition of co-existing vascular anomalies, such as spinal AVMs, is important in patients with tethered cords. The mechanisms involved in this patient's worsening neurological condition after release of the tethered cord are discussed.
Positron Emission Tomography with O-(2-[18F]fluoroethyl)-l-tyrosine versus Magnetic Resonance Imaging in the Diagnosis of Recurrent Gliomas
Authors: Rachinger Walter , Goetz Claudia , Pöpperl Gabriele , Gildehaus Franz Josef , Kreth Friedrich Wilhelm , Holtmannspötter Markus , Herms Jochen , Koch Walter , Tatsch Klaus , Tonn Jörg-Christian 
Published: September 2005

ABSTRACT

OBJECTIVE:
New treatment modalities are available for patients with glioma, which may lead to unspecific changes in posttherapeutic magnetic resonance imaging (MRI) findings. Differentiation between tumor- and therapy-associated contrast enhancement on MRI scans after treatment may be difficult. The aim of this study was to analyze the diagnostic value of O-(2-[18F]fluoroethyl)-l-tyrosine (FET)-positron emission tomography (PET) and MRI in the detection of tumor recurrence in patients with glioma after radiotherapy, radiosurgery, or multimodal treatment.

METHODS:
The study included 36 patients with gliomas and neuroradiological diagnosis of tumor recurrence and 9 patients who had undergone radioimmunotherapy. Patients were consecutively treated between September 2001 and May 2003. A contemporary FET-PET investigation was performed in all patients. A tissue diagnosis was made for comparative analysis in all patients with progressive neuroradiological or clinical findings (32 of 45 patients). In patients with transient neuroradiological or clinical deterioration (13 of 45 patients), clinical follow-up was used to support or contradict the imaging-based diagnosis.

RESULTS:
Tumor recurrence was documented in 31 of 45 patients, and 14 of 45 patients were tumor free. FET-PET and MRI revealed a correct diagnosis in 44 and 36 patients, respectively. The difference was statistically significant (P &lt; 0.01). Concordant findings after MRI and FET-PET were documented in 37 patients and discordant findings in 8 patients. The difference was statistically significant (P &lt; 0.01). Specificity of FET-PET was 92.9%, and sensitivity was 100% (in patients suspected of having recurrent tumor as revealed by MRI). Sensitivity of MRI was 93.5%, and specificity was 50% (P &lt; 0.05).

CONCLUSION:
For patients with gliomas undergoing multimodal treatment or various forms of irradiation, conventional follow-up with MRI is insufficient to distinguish between benign side effects of therapy and tumor recurrence. FET-PET is a powerful tool to improve the differential diagnosis in these patients.
Neurobiological Background for Performing Surgical Intervention in the Inferior Thalamic Peduncle for Treatment of Major Depression Disorders
Authors: Velasco Francisco , Velasco Marcos , Jiménez Fiacro , Velasco Ana Luisa , Salin-Pascual Rafael 
Published: September 2005

ABSTRACTOBJECTIVE:To present a review of evidence for an inhibitory thalamo-orbitofrontal system related to physiopathology of major depression disorders (MDDs) and to postulate that interfering with hyperactivity of the thalamo-orbitofrontal system by means of chronic high-frequency electrical stimulation of its main fiber connection, the inferior thalamic peduncle (ITP), may result in an improvement in patients with MDD.METHODS:Experimentally, the thalamo-orbitofrontal system has been proposed as part of the nonspecific thalamic system. Under normal conditions, the nonspecific thalamic system induces characteristic electrocortical synchronization in the form of recruiting responses that mimic some sleep stages. It also inhibits input of irrelevant sensory stimuli, thus facilitating the process of selective attention. Permanent disruption of the system, via lesioning or temporary inactivation through cooling of the ITP with cryoprobes, results in a state of hyperkinesia, increased attention, and cortical desynchronization.RESULTS:Surgical lesioning of the medial part of orbitofrontal cortex and white matter overlying area 13, which includes the ITP, may result in significant improvement in MDD. Imaging studies (functional magnetic resonance imaging and positron emission tomography) consistently demonstrate hyperactivity in the orbitofrontal cortex and midline thalamic regions during episodes of MDD. This hyperactivity decreases with efficient control of MDD by medical treatment, indicating that orbitofrontal cortex and midline thalamic overactivity are related to the depressive condition. Conversely, noradrenergic and serotoninergic systems in the frontal lobes have been implicated in the pathophysiology of MDD. Although noradrenergic receptor density in the frontal lobe is consistently increased in depressed patients who commit suicide, 5-hydroxytryptamine reuptake blockers, which are potent antidepressive drugs, decrease hypermetabolism in the orbital frontal cortex in MDD. Therefore, the serotonin hypothesis for depression postulates that norepinephrine and serotonin in the frontal lobes are required to maintain antidepressive responsiveness. Dysregulation of the secretion of both neurotransmitters initiates overactivity of orbitofrontal cortex, resulting in depression. It is possible that surgical interventions in this region, including electrical stimulation of ITP, disrupt adrenergic and serotoninergic dysregulation in patients with MDD.CONCLUSION:Circumscribed lesions or electrical stimulation of the ITP, a discrete target easily identified by electrophysiological studies, may improve MDD. Electrical stimulation may have the advantage of being less invasive and more adjustable to patient needs.
Nucleotide Diversity and Linkage Disequilibrium in Cold-Hardiness- and Wood Quality-Related Candidate Genes in Douglas Fir
Authors: Krutovsky Konstantin V , Neale David B 
Published: September 2005

Abstract
Nuclear sequence variation and linkage disequilibrium (LD) were studied in 15 cold-hardiness- and 3 wood quality-related candidate genes in Douglas fir [Pseudotsuga menziesii (Mirb.) Franco]. This set of genes was selected on the basis of its function in other plants and collocation with cold-hardiness-related quantitative trait loci (QTL). The single-nucleotide polymorphism (SNP) discovery panel represented 24 different trees from six regions in Washington and Oregon plus parents of a segregating population used in the QTL study. The frequency of SNPs was one SNP per 46 bp across coding and noncoding regions on average. Haplotype and nucleotide diversities were also moderately high with Hd = 0.827 ± 0.043 and π = 0.00655 ± 0.00082 on average, respectively. The nonsynonymous (replacement) nucleotide substitutions were almost five times less frequent than synonymous ones and substitutions in noncoding regions. LD decayed relatively slowly but steadily within genes. Haploblock analysis was used to define haplotype tag SNPs (htSNPs). These data will help to select SNPs for association mapping, which is already in progress.
Analysis of Repeat-Mediated Deletions in the Mitochondrial Genome of Saccharomyces cerevisiae
Authors: Phadnis Naina , Sia Rey A , Sia Elaine A 
Published: September 2005

Abstract
Mitochondrial DNA deletions and point mutations accumulate in an age-dependent manner in mammals. The mitochondrial genome in aging humans often displays a 4977-bp deletion flanked by short direct repeats. Additionally, direct repeats flank two-thirds of the reported mitochondrial DNA deletions. The mechanism by which these deletions arise is unknown, but direct-repeat-mediated deletions involving polymerase slippage, homologous recombination, and nonhomologous end joining have been proposed. We have developed a genetic reporter to measure the rate at which direct-repeat-mediated deletions arise in the mitochondrial genome of Saccharomyces cerevisiae. Here we analyze the effect of repeat size and heterology between repeats on the rate of deletions. We find that the dependence on homology for repeat-mediated deletions is linear down to 33 bp. Heterology between repeats does not affect the deletion rate substantially. Analysis of recombination products suggests that the deletions are produced by at least two different pathways, one that generates only deletions and one that appears to generate both deletions and reciprocal products of recombination. We discuss how this reporter may be used to identify the proteins in yeast that have an impact on the generation of direct-repeat-mediated deletions.
Identification of Quantitative Trait Loci That Regulate Arabidopsis Root System Size and Plasticity
Authors: Fitz Gerald Jonathan N , Lehti-Shiu Melissa D , Ingram Paul A , Deak Karen I , Biesiada Theresa , Malamy Jocelyn E 
Published: September 2005

AbstractRoot system size (RSS) is a complex trait that is greatly influenced by environmental cues. Hence, both intrinsic developmental pathways and environmental-response pathways contribute to RSS. To assess the natural variation in both types of pathways, we examined the root systems of the closely related Arabidopsis ecotypes Landsberg erecta (Ler) and Columbia (Col) grown under mild osmotic stress conditions. We found that Ler initiates more lateral root primordia, produces lateral roots from a higher percentage of these primordia, and has an overall larger root system than Col under these conditions. Furthermore, although each of these parameters is reduced by osmotic stress in both ecotypes, Ler shows a decreased sensitivity to osmotica. To understand the genetic basis for these differences, QTL for RSS under mild osmotic stress were mapped in a Ler × Col recombinant inbred population. Two robust quantitative trait loci (QTL) were identified and confirmed in near-isogenic lines (NILs). The NILs also allowed us to define distinct physiological roles for the gene(s) at each locus. This study provides insight into the genetic and physiological complexity that determines RSS and begins to dissect the molecular basis for naturally occurring differences in morphology and developmental plasticity in the root system.
A CFD–PBM coupled model for gas–liquid flows
Authors: Wang Tiefeng , Wang Jinfu , Jin Yong 
Published: September 2005

AbstractA computational fluid dynamics–population balance model (CFD‐PBM) coupled model was developed that combines the advantages of CFD to calculate the entire flow field and of the PBM to calculate the local bubble size distribution. Bubble coalescence and breakup were taken into account to determine the evolution of the bubble size. Different bubble breakup and coalescence models were compared. An algorithm was proposed for computing the parameters based on the bubble size distribution, including the drag force, transverse lift force, wall lubrication force, turbulent dispersion force, and bubble‐induced turbulence. With the bubble breakup and coalescence models and the interphase force formulations in this work, the CFD‐PBM coupled model can give a unified description for both the homogeneous and the heterogeneous regimes. Good agreement was obtained with the experimental results for the gas holdup, liquid velocity, and bubble size distribution. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Novel experiments and a mechanistic model for macroinstabilities in stirred tanks
Authors: Paglianti A. , Montante G. , Magelli F. 
Published: September 2005

AbstractIn this work a new experimental technique and a simple model for the identification and the analysis of macro‐instabilities (MIs) in stirred tanks are presented. A pressure transducer is proposed for detecting the MIs that can take place inside a stirred vessel; its main advantages are the non‐intrusivity, cheapness, and simplicity of installation and operation. Moreover, it can be used for both laboratory and industrial scale stirred tanks. The experimental technique and the time series analysis method, based on Fast Fourier Transform (FFT), are shown to provide reliable information on the frequency of MIs, through the comparison of the present data with those, from literature, obtained in similar systems. Its applicability to solid‐liquid systems is also assessed. Afterwards, the data collected in several conditions differing by geometric characteristics of the stirred tanks and by the physical properties of the systems are presented. Finally, a new simplified model, based on the theory of impinging jets,1 is suggested for predicting the MI frequency. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Genome‐wide SNP arrays as a diagnostic tool: Clinical description, genetic mapping, and molecular characterization of Salla disease in an Old Order Mennonite population
Authors: Strauss Kevin A. , Puffenberger Erik G. , Craig David W. , Panganiban Corrie B. , Lee Anne M. , Hu‐Lince Diane , Stephan Dietrich A. , Morton D. Holmes 
Published: September 2005

AbstractAn Old Order Mennonite child was evaluated for gross motor delay, truncal ataxia, and slow linear growth. The diagnostic evaluation, which included sub‐specialty consultations, neuroimaging, and metabolic testing, was long, costly, and did not yield a diagnosis. Recognition of a similarly affected second cousin prompted a genome‐wide homozygosity mapping study using high‐density single nucleotide polymorphism (SNP) arrays. SNP genotypes from two affected individuals and their parents were used to localize the disease locus to a 14.9 Mb region on chromosome 6. This region contained 55 genes, including SLC17A5, the gene encoding the lysosomal N‐acetylneuraminic acid transport protein. Direct sequencing of SLC17A5 in the proband revealed homozygosity for the 115C → T (R39C) sequence variant, the common cause of Salla disease in Finland. Three additional affected Mennonite individuals, ages 8 months to 50 years, were subsequently identified by directed molecular genetic testing. This small‐scale mapping study was rapid, inexpensive, and analytically simple. In families with shared genetic heritage, genome‐wide SNP arrays with relatively high marker density allow disease gene mapping studies to be incorporated into routine diagnostic evaluations. © 2005 Wiley‐Liss, Inc.
Facial and physical features of Aicardi syndrome: Infants to teenagers
Authors: Sutton V. Reid , Hopkins Bobbi J. , Eble Tanya N. , Gambhir Nikki , Lewis Richard A. , Van den Veyver Ignatia B. 
Published: September 2005

AbstractAicardi syndrome is a sporadic disorder that affects primarily females and is hypothesized to be caused by heterozygous mutations in an X‐linked gene. Its main features include of a triad of infantile spasms, agenesis of the corpus callosum, and distinctive chorioretinal lacunae. Additional common findings include moderate to profound mental retardation, gray matter heterotopia, gyral anomalies, and vertebral and rib defects. To date, no consistent facial dysmorphisms have been described. We examined 40 girls with Aicardi syndrome and determined that consistent facial features appeared in over half the study participants and included a prominent premaxilla, upturned nasal tip, decreased angle of the nasal bridge, and sparse lateral eyebrows. Externally apparent microphthalmia was seen in 10/40 (25%). Various skin lesions (including multiple nevi, skin tags, hemangiomas, one giant melanotic nevus, and a history of a previously removed angiosarcoma) were present in 8/40 (20%). Hand abnormalities were seen in 3/40 (7.5%) and included camptodactyly, proximal placement of the thumb and hypoplasia of the fifth finger. This study clearly delineates the existence of a distinctive facial phenotype of Aicardi syndrome not previously described. We recommend that features of a prominent premaxilla with upturned nasal tip and vascular malformations/vascular tumors be added to the modified diagnostic criteria in order to improve the ability of geneticists to diagnose Aicardi syndrome. © 2005 Wiley‐Liss, Inc.
Multiple dose pharmacokinetics of caffeine administered in chewing gum to normal healthy volunteers
Authors: Syed Shariq A. , Kamimori Gary H. , Kelly William , Eddington Natalie D. 
Published: September 2005

AbstractThe purpose of this study was to examine the pharmacokinetics of three doses of caffeine administered as Stay Alert® chewing gum in a multiple dose regimen.Methods: A double‐blind, parallel randomized, four‐treatment study design was employed. The treatment groups were: 50, 100 and 200 mg caffeine and placebo. Subjects were 48 (n = 12 per group), healthy, non‐smoking, males and females who had abstained from caffeine ingestion for at least 20 h prior to dosing, who were randomly assigned to the treatment groups. Caffeine was administered at 2400, 0200 and 0400 h depending on the treatment group. Blood samples were collected pre‐dose and at 5, 15, 30, 45, 60, 75, 90 and 105 min after each caffeine dose. Samples were also collected at 7.5, 8.5 and 18 h after the last dose of caffeine. Plasma caffeine levels were analysed by a validated UV‐HPLC method.Result: The mean Tmax after the third dosing ranged from 0.37 to 1.12 h. Cmax for 50, 100 and 200 mg was 2.69, 3.45 and 6.33 mg/l, respectively. AUCinf for 50, 100 and 200 mg group was 33.2, 46.94 and 86.94 mg/l * h, respectively. AUCinf values suggested a dose proportionate increase. Dose normalized Cmax and AUC0−τ values across doses were not significantly different, suggesting linearity was maintained after multiple doses of the Stay Alert® chewing gum. There were no group related differences in elimination.Conclusions: The results suggest that caffeine administered in the gum formulation (Stay Alert® chewing gum) via a multiple dosing regimen provides an effective and convenient means of maintaining effective concentrations of caffeine that would in some operational scenarios be desirable for maintaining alertness and performance in sleep deprived individuals. Copyright © 2005 John Wiley & Sons, Ltd.
Transport phenomena during freezing of adipose tissue derived adult stem cells
Authors: Thirumala Sreedhar , Gimble Jeffrey M. , Devireddy Ram V. 
Published: September 2005

AbstractIn the present study a well‐established differential scanning calorimeter (DSC) technique is used to measure the water transport phenomena during freezing of stromal vascular fraction (SVF) and adipose tissue derived adult stem (ADAS) cells at different passages (Passages 0 and 2). Volumetric shrinkage during freezing of adipose derived cells was obtained at a cooling rate of 20°C/min in the presence of extracellular ice and two different, commonly used, cryoprotective agents, CPAs (10% DMSO and 10% Glycerol). The adipose derived cells were modeled as spheres of 50 µm diameter with an osmotically inactive volume (Vb) of 0.6Vo, where Vo is the isotonic cell volume. By fitting a model of water transport to the experimentally obtained volumetric shrinkage data, the “best‐fit” membrane permeability parameters (reference membrane permeability to water, Lpg or Lpg[cpa] and the activation energy, ELp or ELp[cpa]) were determined. The “best‐fit” membrane permeability parameters for adipose derived cells in the absence and presence of CPAs ranged from: Lpg = 23.1–111.5 × 10−15 m3/Ns (0.135–0.652 µm/min‐atm) and ELp = 43.1–168.8 kJ/mol (9.7–40.4 kcal/mol). Numerical simulations of water transport were then performed under a variety of cooling rates (5–100°C/min) using the experimentally determined membrane permeability parameters. And finally, the simulation results were analyzed to predict the optimal rates of freezing adipose derived cells in the presence and absence of CPAs. © 2005 Wiley Periodicals, Inc.
Prediction of gas‐liquid mass transfer coefficient in sparged stirred tank bioreactors
Authors: Garcia‐Ochoa Felix , Gomez Emilio 
Published: September 2005

AbstractOxygen mass transfer in sparged stirred tank bioreactors has been studied. The rate of oxygen mass transfer into a culture in a bioreactor is affected by operational conditions and geometrical parameters as well as the physicochemical properties of the medium (nutrients, substances excreted by the micro‐organism, and surface active agents that are often added to the medium) and the presence of the micro‐organism. Thus, oxygen mass transfer coefficient values in fermentation broths often differ substantially from values estimated for simple aqueous solutions. The influence of liquid phase physicochemical properties on k
La must be divided into the influence on kL and a, because they are affected in different ways. The presence of micro‐organisms (cells, bacteria, or yeasts) can affect the mass transfer rate, and thus kLa values, due to the consumption of oxygen for both cell growth and metabolite production. In this work, theoretical equations for kLa prediction, developed for sparged and stirred tanks, taking into account the possible oxygen mass transfer enhancement due to the consumption by biochemical reactions, are proposed. The estimation of k
La is carried out taking into account a strong increase of viscosity broth, changes in surface tension and different oxygen uptake rates (OURs), and the biological enhancement factor, E, is also estimated. These different operational conditions and changes in several variables are performed using different systems and cultures (xanthan aqueous solutions, xanthan production cultures by Xanthomonas campestris, sophorolipids production by Candida bombicola, etc.). Experimental and theoretical results are presented and compared, with very good results. © 2005 Wiley Periodicals, Inc.
Engineering an affinity tag for genetically encoded cyclic peptides
Authors: Naumann Todd A. , Savinov Sergey N. , Benkovic Stephen J. 
Published: September 2005

AbstractPeptide expression libraries are valuable probes of cellular function. SICLOPPS technology merges the principal advantages of both genetic methods and small‐molecule approaches in yielding superior library sizes of operationally stable, structurally well‐defined entities with an established biological and medicinal record. Here, we describe development, application, and the first‐generation library implementation of an expressed affinity tag for a library of cyclic peptides. A tripeptide streptavidin‐binding motif (HPQ) proved to be compatible with presentation from a backbone cyclized template. A resulting peptide was employed as a sensitive indicator of peptide splicing, expression, and recovery as well as an affinity tag for one‐step purification. Specific recognition of the tag by streptavidin was also critical for an analysis of intein mutants. Finally, the initially identified probe was used as a template for design of a streptavidin‐responsive cyclic peptide library. © 2005 Wiley Periodicals, Inc.