bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intraoperative ultrasonography as a guide to patient selection for duraplasty after suboccipital decompression in children with Chiari malformation Type I
Authors: McGirt Matthew J. , Attenello Frank J. , Datoo Ghazala , Gathinji Muraya , Atiba April , Weingart Jon D. , Carson Benjamin , Jallo George I. 
Published: June 2008

Object
Indications for duraplasty in treatment of Chiari malformation Type I (CM-I) remain unclear. In the present study, the authors evaluate their surgical experience to determine whether intraoperative ultrasonography is effective in the selection of patients with CM-I who can be adequately treated with craniectomy alone without duraplasty.

Methods
The authors reviewed the records of 256 children who underwent first-time hindbrain decompression for CM-I. Craniectomy alone (without duraplasty) was performed when intraoperative ultrasonography suggested adequate decompression of the subarachnoid spaces ventral and dorsal to the tonsils after suboccipital craniectomy alone. Duraplasty was performed if intraoperative ultrasonography demonstrated persistent dural compression of the tonsils following craniectomy. Symptom recurrence as a function of time was compared between cases of duraplasty versus suboccipital decompression alone stratified by extent of tonsillar herniation.

Results
Duraplasty was performed in 140 patients (55%), and suboccipital decompression alone was performed in 116 patients (45%). Patients underwent follow-up for 29 ± 15 months. Symptoms included headache in 192 patients (75%) and lower cranial nerve and brainstem dysfunction in 68 (27%). In 38 patients (15%) there was tonsillar herniation rostral to the C-1 lamina, in 195 (76%) it extended between the C-1 and C-2 lamina, and in 23 patients (9%) there was herniation caudal to the lower border of the C-2 lamina. In children with tonsillar herniation caudal to C-1, ultrasonography-guided suboccipital decompression alone was associated with a 2-fold increase in the risk of symptom recurrence compared with those who also underwent duraplasty (p = 0.01). In children with tonsillar herniation rostral to C-1, outcome was equivalent between suboccipital decompression alone and duraplasty (p = 0.41).

Conclusions
In the setting of moderate-to-severe tonsillar CM-I, intraoperative ultrasonography demonstrating decompression of the subarachnoid spaces ventral and dorsal to the tonsils may not effectively select patients in whom bone decompression alone is sufficient. Duraplasty may be warranted in cases of tonsillar herniation that extends below the C-1 lamina regardless of intraoperative ultrasonography findings. More objective cerebrospinal fluid flow or volumetric measures may be needed intraoperatively to guide duraplasty in patients with more pronounced tonsillar herniation.
Quantitative diffusion tensor imaging and intellectual outcomes in spina bifida
Authors: Hasan Khader M. , Sankar Ambika , Halphen Christopher , Kramer Larry A. , Ewing-Cobbs Linda , Dennis Maureen , Fletcher Jack M. 
Published: June 2008

Object
Patients with spina bifida (SB) have variable intellectual outcomes. The authors used diffusion tensor (DT) imaging to quantify whole-brain volumes of gray matter, white matter, and cerebrospinal fluid (CSF), and perform regional quantitative microstructural assessments of gray matter nuclei and white matter tracts in relation to intellectual outcomes in patients with SB.

Methods
Twenty-nine children with myelomeningoceles and 20 age- and sex-matched children with normal neural tube development underwent MR imaging with DT image acquisition and assessments of intelligence. The DT imaging–derived metrics were the fractional anisotropy (FA), axial (parallel), and transverse (perpendicular) diffusivities. These metrics were also used to segment the brain into white matter, gray matter, and CSF. A region-of-interest analysis was conducted of the white and gray matter structures implicated in hydrocephalus.

Results
The amount of whole-brain gray matter was decreased in patients with SB, with a corresponding increase in CSF (p < 0.0001). Regional transverse diffusivity in the caudate nucleus was decreased (p < 0.0001), and the corresponding FA was increased (p < 0.0001), suggesting reduced dendritic branching and connectivity. Fractional anisotropy in the posterior limb of the internal capsule increased in the myelomeningocele group (p = 0.02), suggesting elimination of some divergent fascicles; in contrast, the FA in several white matter structures (such as the corpus callosum genu [p < 0.001] and arcuate fasciculus) was reduced, suggesting disruption of myelination. Diffusion tensor imaging–metrics involving gray matter volume and the caudate nucleus, but not other structures, predicted variations in IQ (r = 0.37–0.50; p < 0.05).

Conclusions
Diffusion tensor imaging–derived metrics provide noninvasive neuronal surrogate markers of the pathogenesis of SB and predict variations in general intellectual outcomes in children with this condition.
Intracranial pressure waves: characterization of a pulsation absorber with notch filter properties using systems analysis
Authors: Zou Rui , Park Eun-Hyoung , Kelly Erin McCormack , Egnor Michael , Wagshul Mark E. , Madsen Joseph R. 
Published: June 2008

Object
The relationship between the waveform of intracranial pressure (ICP) and arterial blood pressure can be quantitatively characterized using a newly developed technique in systems analysis, the time-varying transfer function. This technique considers the arterial blood pressure as an input signal composed of multiple frequencies represented in the output ICP according to the transfer function imposed by the intracranial system on the input signal. The transfer function can change with time and with physiological manipulations. The authors examined data obtained from canine experiments involving manipulations of ICP.

Methods
The authors analyzed 11 experiments from 3 normal mongrel dogs under conditions of normal ICP and with changes in ICP made by bolus injection, infusion, or withdrawal of cerebrospinal fluid by using time-varying transfer function.

Results
During normal ICP periods, the gain of the transfer function displayed a deep notch (≥ 1 log unit) centered at or near the cardiac frequency. In systems terms, the intracranial compartment under normal conditions appears to act as a notch filter attenuating the cardiac frequency input relative to other frequencies. Epochs of ICP elevation showed suppression of the notch, and the notch was restored when ICP returned to normal.

Conclusions
The intracranial system in these animals could be considered to include a pulsation absorber for which the target frequency appears to be close to the cardiac frequency. One possible source for such an absorber mechanism might be the free movement of cerebrospinal fluid, implying that impairment of this motion may have important clinical implications in various neurological conditions such as hydrocephalus.
A novel approach to sagittal balance restoration following iatrogenic sacral fracture and resulting sacral kyphotic deformity
Authors: Hsieh Patrick C. , Ondra Stephen L. , Wienecke Robert J. , O'Shaughnessy Brian A. , Koski Tyler R. 
Published: July 2008

✓The authors describe the use of sacral pedicle subtraction osteotomy (PSO) with multiple sacral alar osteotomies for the correction of sacral kyphosis and pelvic incidence and for achieving sagittal balance correction in cases of fixed sagittal deformity after a sacral fracture.In this paper, the authors report on a novel technique using a series of sacral osteotomies and a sacral PSO to correct a fixed sagittal deformity in a patient with a sacral fracture that had healed in a kyphotic position. The patient sustained this fracture after a previous surgery for multilevel instrumented fusion. Preoperative and postoperative radiographic studies are reviewed and the clinical course and outcome are presented.Experts agree that the pelvic incidence is a fixed parameter that dictates the morphological characteristics of the pelvis and affects spinopelvic orientation and sagittal spinal alignment. An increased pelvic incidence is associated with a higher degree of spondylolisthesis in the lumbosacral junction, and increased shear forces across this junction. The authors demonstrate that the pelvic incidence can be altered and corrected with a series of sacral osteotomies to improve sacral kyphosis, compensatory lumbar hyperlordosis, and sagittal balance.
Surgical results in patients with tuberculosis of the spine and severe lower-extremity motor deficits: a retrospective study of 48 patients
Authors: Kiran Narayanam Anantha Sai , Vaishya Sandeep , Kale Shashank Sharad , Sharma Bhavani Shankar , Mahapatra Ashok Kumar 
Published: July 2008

ObjectSignificant numbers of patients with spinal tuberculosis (TB), especially in developing countries, still present late after disease onset with severe neurological deficits. The authors conducted a study to assess the outcome in these patients.MethodsFifty-nine patients with spinal TB and severe motor deficits underwent surgery at the authors' center during the past 10 years. Data obtained in 48 patients with a minimum of 3 months of follow up (mean follow-up period 12.8 months) were analyzed. The disease in 34 patients was characterized by Frankel Grade A/B (Medical Research Council Grade 0/5) and in 14 patients by Frankel Grade C (unable to walk even with support) at admission. Thirty (88%) of the 34 patients with Frankel Grade A/B status and 13 (92.8%) of the 14 patients with Frankel Grade C status at admission experienced improvement to Frankel Grade D/E (walking with or without support) at the last follow-up examination 3 or more months after surgery. The degree of improvement exhibited by patients with a Frankel Grade A/B spinal cord injury was comparable to that shown by patients with Frankel Grade C status. Even patients with flaccid paraplegia, gross sensory deficit, prolonged weakness, spinal cord signal changes demonstrated on magnetic resonance imaging, and bladder involvement have experienced dramatic improvement in motor function since surgery. A significant number of the patients have shown remarkable improvement in other symptoms such as pain (91.6%), spasticity (88%), and bladder symptoms (88%).ConclusionsA significant proportion of patients with spinal TB and severe motor deficits experience remarkable improvement after surgical decompression and hence should undergo surgery even though they may be suffering from paraplegia of considerable duration.
Nonsteroidal antiinflammatory drugs for postoperative pain management after lumbar spine surgery: a meta-analysis of randomized controlled trials
Authors: Jirarattanaphochai Kitti , Jung Surachai 
Published: June 2008

ObjectThe authors undertook this meta-analysis to assess the efficacy and safety of nonsteroidal antiinflammatory drugs (NSAIDs) in addition to opioid analgesics on perioperative pain management in lumbar spine surgery.MethodsThe authors searched MEDLINE, Excerpta Medica (EMBASE), The Cochrane Library, CINAHL, PsycINFO, Allied and Complementary Medicine (AMED), and Science Citation Index Expanded databases. In addition, they manually searched key journals and their references. They included randomized trials comparing the use of NSAIDs in addition to opioid analgesics versus opioid analgesics alone after posterior lumbar discectomy, laminectomy, or spinal fusion. Two independent reviewers performed an assessment of the quality of the methods.ResultsSeventeen studies comprising 400 patients who received NSAIDs in addition to opioid analgesics and 389 patients receiving opioid analgesics alone were included. Patients receiving NSAIDs in addition to opioid analgesics had lower pain scores and consumed fewer opioids than the group receiving opioid analgesics alone. There was no difference in the incidence of adverse effects.ConclusionsThis meta-analysis provides evidence that the addition of NSAIDs to opioid analgesics in lumbar spine surgery provided better pain control than opioid analgesics alone.
Management of sciatica due to lumbar disc herniation in the Netherlands: a survey among spine surgeons
Authors: Arts Mark P. , Peul Wilco C. , Koes Bart W. , Thomeer Ralph T. W. M. , _ _ 
Published: June 2008

Object
Although clinical guidelines for sciatica have been developed, various aspects of lumbar disc herniation remain unclear, and daily clinical practice may vary. The authors conducted a descriptive survey among spine surgeons in the Netherlands to obtain an overview of routine management of lumbar disc herniation.

Methods
One hundred thirty-one spine surgeons were sent a questionnaire regarding various aspects of different surgical procedures. Eighty-six (70%) of the 122 who performed lumbar disc surgery provided usable questionnaires.

Results
Unilateral transflaval discectomy was the most frequently performed procedure and was expected to be the most effective, whereas percutaneous laser disc decompression was expected to be the least effective. Bilateral discectomy was expected to be associated with the most postoperative low-back pain. Recurrent disc herniation was expected to be lowest after bilateral discectomy and highest after percutaneous laser disc decompression. Complications were expected to be highest after bilateral discectomy and lowest after unilateral transflaval discectomy. Nearly half of the surgeons preferentially treated patients with 8–12 weeks of disabling leg pain. Some consensus was shown on acute surgery in patients with short-lasting drop foot and those with a cauda equina syndrome, and nonsurgical treatment in patients with long-lasting, painless drop foot. Most respondents allowed postoperative mobilization within 24 hours but advised their patients not to resume work until 8–12 weeks postoperatively.

Conclusions
Unilateral transflaval discectomy was the most frequently performed procedure. Minimally invasive techniques were expected to be less effective, with higher recurrence rates but less postoperative low-back pain. Variety was shown between surgeons in the management of patients with neurological deficit. Most responding surgeons allowed early mobilization but appeared to give conservative advice in resumption of work.
Fine structure of cartilage canal and vascular buds in the rabbit vertebral endplate
Authors: Kobayashi Shigeru , Baba Hisatoshi , Takeno Kenichi , Miyazaki Tsuyoshi , Uchida Kenzo , Kokubo Yasuo , Nomura Eiki , Morita Chisato , Yoshizawa Hidezo , Meir Adam 
Published: June 2008

Object
The vascular terminations (vascular buds) in the bone–disc junction area are structurally very similar to cartilage. In all previous studies to date, however, the roles of cartilage canals and vascular buds were mainly discussed using histological and transparent sections but not electron microscopic sections. The purpose of this study was to clarify the ultrastructure of the vascular bud seen in the bone–disc junction in comparison to the cartilage canal.

Methods
Japanese white rabbits from 2 days to 6 months of age were used in this study. The bone–disc junctions were examined by microangiogram and light and electron microscopy, and morphological changes and their association with the age of the animals were noted.

Results
The fine structure of the vascular bud was similar to that of the cartilage canal that nourished the growing cartilage. They were composed of arteries, veins, capillaries, cells resembling fibroblasts, and macrophages. The capillaries in the cartilage canal were all the fenestrated type. Vascular buds were seen over the entire bone–cartilage interface, with maximum density in the area related to the nucleus pulposus. They projected into the bone–disc junction area from the vertebral body contacting the cartilaginous endplate directly.

Conclusions
The results of this study clarify the formation process and ultrastructure of the vascular bud seen in the bone–disc junction. The authors found a strong structural resemblance between the vascular bud and the cartilage canal and hypothesize that the immature cells seen surrounding the cartilage canal and vascular bud represent a common precursor for the 3 main types of connective tissue cells seen during early vertebral development.
Nonheme Iron Halogenases
Authors: Blasiak Leah C , Drennan Catherine L 
Published: June 2008

Abstract

Nonheme iron halogenases require Fe(II), O
2
, α‐ketoglutarate (αKG), and a halide ion and catalyze halogenation at unactivated, aliphatic carbons on their substrates. The nonheme iron halogenase SyrB2, from

Pseudomonas syringae

, catalyzes chlorination of threonine during biosynthesis of the plant toxin syringomycin. The X‐ray crystal structure of SyrB2 revealed a mononuclear iron center coordinated by two histidine residues, bidentate αKG, and a chloride ion. Spectroscopic studies on the nonheme iron halogenase CytC3 from
Streptomyces
sp. RK95‐74 have implicated an iron(IV)‐oxo as a hydrogen atom abstracting species in a mechanism similar to the related nonheme iron dioxygenases.
The Impact of Climate Change and Variability on Heavy Precipitation, Floods, and Droughts
Authors: Trenberth Kevin E 
Published: June 2008

Abstract
There is a direct influence of global warming on changes in precipitation and heavy rains. Increased heating leads to greater evaporation and thus surface drying, thereby increasing intensity and duration of drought. However, the water‐holding capacity of air increases by about 7% per 1 °C warming, which leads to increased water vapor in the atmosphere, and this probably provides the biggest influence on precipitation. Storms, whether individual thunderstorms, extratropical rain or snow storms, or tropical cyclones and hurricanes, supplied by increased moisture, produce more intense precipitation events that are widely observed to be occurring, even in places where total precipitation is decreasing. In turn, this increases the risk of flooding. Patterns of where it rains also have been observed to change, with dry areas becoming drier (generally throughout the subtropics) and wet areas becoming wetter, especially in mid to high latitudes. This pattern is simulated by climate models and is projected to continue into the future. Since more precipitation occurs as rain instead of snow with warming, and snow melts earlier, there is increased runoff and risk of flooding in early spring, but increased risk of drought in deep summer, especially over continental areas.
Boron: Metallacarbaboranes
Authors: Housecroft Catherine E. 
Published: June 2008

Abstract
Metallacarbaboranes comprise carbon, boron, and metal‐atom‐containing clusters. The classes of compounds and their syntheses are described, as well as skeletal isomerism, electrochemistry, and reactivity. The applications of metallacarbaboranes in biosciences, medicinal chemistry, and materials science are gradually becoming more significant.
ResonanceRaman Spectroscopy
Authors: Czernuszewicz Roman S. , Zaczek Marzena B. 
Published: June 2008

AbstractResonance Raman (RR) spectroscopy is an invaluable and widely used probe of structure and bonding for chromophoric transition metal centers in proteins and enzymes. The spectacular increase in detection sensitivity and selectivity of RR spectroscopy for vibrations that are localized in the absorbing center(s) of the molecule has revolutionized the vibrational spectroscopic field of bioinorganic systems. In this article, we explain the characteristics of RR spectra, emphasizing the kind of information that can be obtained and the rules for optimal resonance enhancement. We then discuss the applications of RR scattering to the study of structural dynamics of two different mononuclear metal‐cysteinate sites, type‐1 copper in cupredoxins and Fe(S‐Cys)4center in rubredoxins, using a combination of site‐directed mutagenesis, production of isotopically labeled proteins, and cryogenic‐temperature RR methods. These chromophores, involved in biological electron transport, have been very suitable subjects for RR studies because they exhibit strong absorption bands in the visible region due to (Cys)S → Cu(II) (∼625 nm) and (Cys)S → Fe(III) (∼500–570 nm) charge‐transfer electronic transitions that facilitate the observation of resonantly enhanced Cu‐and Fe‐thiolate vibrations.
Receptor Theory
Authors: Kenakin Terry 
Published: June 2008

AbstractReceptor theory assigns mathematical rules to biological systems in order to quantify drug effects and define what biological systems can and cannot do, leading to the design of experiments that may further modify the model. Drug receptor theory also furnishes the tools for quantifying the activity of drugs in a system‐independent manner, essential because drugs are almost always studied in test systems somewhat removed from the therapeutic system for which they are intended. Since biological systems operate at different set points in the body under different conditions, the ability to predict drug effects under a variety of circumstances is important. This unit provides a historical perspective of classical receptor theory and the currently used operational model of drug effects. The mechanism of drug receptor function is also described in terms of the various iterations of the ternary complex model, the two‐state theory for ion channels, and a probabilistic model of multiple receptor conformations.Curr. Protoc. Pharmacol. 41:1.2.1‐1.2.28. © 2008 by John Wiley & Sons, Inc.
Rodent Model of Attention: The 5‐Choice Serial Reaction Time Task
Authors: Higgins Guy A. , Breysse Nathalie 
Published: June 2008

AbstractThe 5‐choice serial reaction time task (5‐CSRTT) is the most widely used test to measure attentional performance in rodents. The basic test design involves training animals to respond to a brief visual stimulus presented unpredictably in one of five locations. Once trained to stable performance levels, the effects of experimental manipulations on response speed and choice accuracy are measured and each are related to attentional performance. Increasingly, the test is also used to examine aspects of response control. Having been adapted from a human task, the test has also been successfully extended to the mouse and primate, thus highlighting its translational value. Increasingly this test is being applied in drug discovery efforts, primarily to identify novel drug treatments for conditions associated with attention deficits.Curr. Protoc. Pharmacol. 41:5.49.1‐5.49.20. © 2008 by John Wiley & Sons, Inc.
Synthesis of 2′‐Cyclohexenylnucleosides and Corresponding CeNA Building Blocks
Authors: Liu Feng‐Wu , Di Salvo Alberto , Herdewijn Piet 
Published: June 2008

AbstractA cyclohexene ring has similar structural properties and conformational behavior to a saturated five‐membered furanose ring. In particular, it has good hydrolytic stability. Cyclohexenylnucleosides have been utilized in antiviral drug design, and some nucleosides and oligonucleotides based on the cyclohexene system have been developed. For further investigation of these modified nucleosides and oligonucleotides, synthesis of the chiral cyclohexenylnucleosides in high enantiomeric excess and in bulk quantities is necessary. This unit describes the complete synthesis of four enantiomerically pure 5′‐hydroxy‐4′‐hydroxymethyl‐2′‐cyclohexenylnucleosides (thymine, cytosine, guanine, and adenine) and the four corresponding N‐protected 4′‐(monomethoxytrityl)oxymethyl cyclohexenyl nucleic acids (CeNA) building blocks. The chirality of these compounds is 1′S, 4′R, and 5′S. Curr. Protoc. Nucleic Acid Chem. 33:1.20.1‐1.20.21. © 2008 by John Wiley & Sons, Inc.