bluuebunny/crossref_metadata_2025 huggingface dataset:
Challenges of DNA‐Based Mark‐Recapture Studies of American Black Bears
Authors: SETTLAGE KATIE E. , VAN MANEN FRANK T. , CLARK JOSEPH D. , KING TIMOTHY L.
Published: April 2008

Abstract: We explored whether genetic sampling would be feasible to provide a region‐wide population estimate for American black bears (Ursus americanus) in the southern Appalachians, USA. Specifically, we determined whether adequate capture probabilities (p > 0.20) and population estimates with a low coefficient of variation (CV < 20%) could be achieved given typical agency budget and personnel constraints. We extracted DNA from hair collected from baited barbed‐wire enclosures sampled over a 10‐week period on 2 study areas: a high‐density black bear population in a portion of Great Smoky Mountains National Park and a lower density population on National Forest lands in North Carolina, South Carolina, and Georgia. We identified individual bears by their unique genotypes obtained from 9 microsatellite loci. We sampled 129 and 60 different bears in the National Park and National Forest study areas, respectively, and applied closed mark‐recapture models to estimate population abundance. Capture probabilities and precision of the population estimates were acceptable only for sampling scenarios for which we pooled weekly sampling periods. We detected capture heterogeneity biases, probably because of inadequate spatial coverage by the hair‐trapping grid. The logistical challenges of establishing and checking a sufficiently high density of hair traps make DNA‐based estimates of black bears impractical for the southern Appalachian region. Alternatives are to estimate population size for smaller areas, estimate population growth rates or survival using mark‐recapture methods, or use independent marking and recapturing techniques to reduce capture heterogeneity.
A Meta‐Analysis of the Impact of African Elephants on Savanna Vegetation
Authors: GULDEMOND ROBERT , VAN AARDE RUDI
Published: April 2008

Abstract: Large herbivores such as elephants (Loxodonta africana) apparently have a negative impact on woody vegetation at moderate to high population densities. The confounding effects that fire, drought, and management history have may complicate assignment of such impacts to herbivory. We reviewed 238 studies published over 45 years and conducted a meta‐analysis based on 21 studies that provided sufficient information on response of woody vegetation to elephants. We considered size and duration of studies, elephant densities, rainfall, fences, and study outcomes in our analysis. We detected a disproportionate citation of 20 published studies in our database, 15 of which concluded that woody vegetation responded negatively to elephants. Our analysis showed that high elephant densities had a negative effect on woody vegetation but that rainfall and presence of fences influenced these effects. In arid savannas, woody vegetation always responded negatively to elephants. In transitional savannas, an increase in elephant densities did not influence woody vegetation response. In mesic savannas, negative responses of woody vegetation increased when elephants occurred at higher densities, whereas elephants confined by fences also had more negative effects on woody plants than elephants that were not confined. Our analysis suggested that rainfall and fences influenced elephant density related impact and that research results were often site‐specific. Local environmental conditions and site‐specific objectives should be considered when developing management actions to curb elephant impacts on woody vegetation.
Modeling Response of Target and Nontarget Dolphins to Biopsy Darting
Authors: GORGONE ANTOINETTE M. , HAASE PATTI A. , GRIFFITH ERIC S. , HOHN ALETA A.
Published: April 2008

Abstract: Remote biopsy sampling is a valuable technique to collect data on free‐ranging cetaceans. Numerous researchers have evaluated effects of biopsy darting on the target animal, but biopsy sampling may also have unintentional effects on nearby nontarget animals. We evaluated reactions of target and nontarget animals during remote biopsy sampling conducted on bottlenose dolphins (Tursiops truncatus) in August 2004 off Folly Beach, South Carolina, and Jekyll Island, Georgia, USA, and in February‐March and July‐August 2005 off Hilton Head, South Carolina. We examined external factors that might influence response of the target animal as well as other individuals in the group. Target animals reacted to biopsy attempts 90.9% (n = 475) of the time. Of these, 97.5% (n = 432) of reactions were to biopsy hits, and 84.4% (n = 320) of all hits had reactions recorded as low. Nontarget animals reacted 21.9% (n = 1,158) of the time; interanimal distance from target animal, season, sea state, and depth affected reactions of nontarget animals. Overall, however, biopsy effects appear to be minimal. We present a statistical tool for identifying factors that elicit greater reactions. This model could be adapted for species or locations, as needed, to identify factors that could influence effects of biopsy sampling.
Long‐Distance Dispersal of a Female Cougar in a Basin and Range Landscape
Authors: STONER DAVID C. , RIETH WENDY R. , WOLFE MICHAEL L. , MECHAM MCLAIN B. , NEVILLE ANN
Published: April 2008

Abstract: We used Global Positioning System technology to document distance, movement path, vegetation, and elevations used by a dispersing subadult female cougar (Puma concolor) through the fragmented habitat of the Intermountain West, USA. Over the course of 1 year, female number 31 moved 357 linear km, but an actual distance of 1,341 km from the Oquirrh Mountains, Utah to the White River Plateau, Colorado, constituting the farthest dispersal yet documented for a female cougar. This cougar successfully negotiated 4 major rivers and one interstate highway while traversing portions of 3 states. Our data suggest that transient survival, and therefore total distance moved, may be enhanced when dispersal occurs during the snow‐free season due to low hunting pressure and greater access to high elevation habitats. Long‐distance movements by both sexes will be required for the recolonization of vacant habitats, and thus inter‐state management may be warranted where state boundaries do not coincide with effective dispersal barriers.
Locating the Fragments of the State and Their Limits: Water Policymaking in Israel during the 1950s
Authors: Alatout Samer
Published: April 2008

Three elements dominated scholarship on Israeli water politics and policymaking in the 1950s: (1) the state is often taken to be a fully established actor since its inception in 1948; (2) Israeli water policymaking was dominated by geopolitical and regional concerns over security and access to shared water resources; (3) water was, and continues to be, a scarce resource. This article argues that these elements result in the depoliticization of Israeli water policies and offers three counterarguments. First, the totality of any state is an ever-illusive construct. Second, Israeli water politics had an internal dimension that has to be investigated in its own right. Third, scarcity did not acquire the status of a "fact" until the mid-1950s. In fact, the struggle over the notions of water abundance and scarcity was an essential part of working through the political conflicts over the meaning of Jewish subjectivity, the boundaries of the state, and its right to intervene in civil society.
Urban Ecology of Shrinking Cities: An Unrecognized Opportunity?
Authors: Haase Dagmar
Published: April 2008

Whereas environmental and social impacts of urban sprawl are widely discussed among scholars from both the natural and social sciences, the spatial consequences of urban decline are nearly neglected when discussing the impacts of land transition. Within the last decade, "shrinkage" and "perforation" have arisen as new terms to explain the land use development of urban regions faced with demographic change, particularly decreasing fertility, aging, and out-migration. Although shrinkage is far from being a "desired" scenario for urban policy makers, this paper argues that a perforation of the built-up structure in dense cities might bring up many positive implications.
Cosmopolitan Natures: Paradigms and Politics in Australian Environmental Management
Authors: Strang Veronica
Published: April 2008

Environmental management in Australia has recently shifted away from local rural communities into the hands of largely urban environmental and government agencies, sparking an intensifying contest for the control of land and resources between geographically and socially stable communities and more mobile translocal groups. There are major disjunctions between the conceptual models promulgated in this contest. Highly specific, holistic, and integrative cultural paradigms of human-environmental interaction vie with an increasingly dominant technomanagerial environmental model emerging from global discourses and knowledge practices. Categorizing "Nature" as a separate, nonhuman domain, this more cosmopolitan approach fails, intellectually and practically, to integrate social and cultural issues into environmental management. Nevertheless, its proponents are provided with increasing authority by their relationships with wider agencies of governance. Building on long-term ethnographic research in Far North Queensland, this paper explores how local and cosmopolitan environmentalisms are contested in a particular ethnographic context.
Environmental Ethics, Livelihood, and Human Rights: Subaltern-Driven Cosmopolitanism?
Authors: Raman Ravi K.
Published: April 2008

Through a case study of an anti-cola struggle in a south Indian village, this paper promotes the conceptual treatment of subaltern cosmopolitanism in the contemporary context of anticorporate social movements. In this situation the multiple issues raised by a local movement, such as livelihood, sustainability, and human rights, sensitize each of the new social agencies involved, within and outside the borders of the local state, and help forge a solidarity network across borders with their universally relevant concerns of environmental ethics and livelihood rights. It is further suggested that it is precisely the new politics of ecology and culture articulated by the subalterns that constructs an enduring and viable future for social movements.
The principles of skull base radiosurgery
Authors: Kondziolka Douglas , Flickinger John C. , Lunsford L. Dade
Published: April 2008

✓ Stereotactic radiosurgery is commonly used for selected patients with benign cranial base tumors. The goal of radiosurgery is cessation of tumor growth and preservation of neurological function. Over the last 2 decades, the technique of radiosurgery has evolved due to improved imaging, better radiosurgical devices and software, and the continued analysis of results. In this report, the authors discuss technical concepts and dose selection in skull base radiosurgery.
Radiation therapy in the treatment of pituitary tumors
Authors: Ghostine Samer , Ghostine Michelle S. , Johnson Walter D.
Published: April 2008

✓ The treatment of pituitary tumors has progressed into a multidisciplinary approach that involves neurosurgeons, radiation oncologists, and endocrinologists. This has allowed improved outcomes in treatment of pituitary tumors due to a combination of surgical, medical, and radiation therapies. In this study, the authors review the role of radiation therapy in the treatment of pituitary adenomas.
Failure of long-term nerve root stimulation to improve neuropathic pain
Authors: Weigel Ralf , Capelle Hans-Holger , Krauss Joachim K.
Published: April 2008

Object

Stimulation of dorsal nerve roots or dorsal root ganglia was reported to alleviate neuropathic pain in selected patients during the early postoperative period. A prospective study was initiated to investigate long-term outcome in patients with neuropathic pain of the lower extremities or groin who were treated with selective nerve root stimulation.

Methods

The study included patients with dermatomally distributed neuropathic pain who were > 18 years of age and in whom the pain was refractory to medical treatment. The patients were prospectively evaluated using a visual analog scale (VAS) for pain and ratings for quality of life, activities of daily living, and depression preoperatively, and after defined intervals postoperatively. Implantation of electrodes was performed via foraminotomy or interlaminar fenestration in an awake procedure. An implantable pulse generator (IPG) was implanted in a second operation after successful test stimulation performed over several days.

Results

Three patients were included in the study before it was stopped. The mean maximum pain score preoperatively was 9.3. All patients had successful test stimulation with > 50% pain relief prior to implantation of the IPG (mean maximum VAS Score 3.6). The beneficial effect, however, was lost within the next few months despite adjustment of stimulation settings. With higher amplitudes, side effects such as pain attacks or motor phenomena occurred. They disappeared after stopping stimulation, but neuropathic pain recurred to its full extent. The study was stopped 18 months after the first implantation, when the third and last IPG of this series was explanted. Due to the overall short-term effect of stimulation, no relevant changes in ratings for quality of life, activities of daily living, or depression were detected.

Conclusions

Spinal nerve root stimulation proved to be effective on short-term follow-up in 3 patients with neuropathic pain in a dermatomal distribution. Long-term stimulation, however, was disappointing because of the loss of effectiveness and the occurrence of side effects.
Normobaric oxygen therapy strategies in the treatment of postcraniotomy pneumocephalus
Authors: Gore Pankaj A. , Maan Harvinder , Chang Steve , Pitt Alan M. , Spetzler Robert F. , Nakaji Peter
Published: April 2008

Object

Postsurgical pneumocephalus is an unavoidable sequela of craniotomy. Sufficiently large volumes of intracranial air can cause headaches, lethargy, and neurological deficits. Supplemental O2 to increase the rate of absorption of intracranial air is a common but unsubstantiated neurosurgical practice. To the authors' knowledge, this is the first prospective study to examine the efficacy of this therapy and its effect on the rate of pneumocephalus absorption.

Methods

Thirteen patients with postoperative pneumocephalus that was estimated to be ≥ 30 ml were alternately assigned to breathe 100% O2 using a nonrebreather mask (treatment group) or to breathe room air (control group) for 24 hours. Head computed tomography (CT) scans without contrast enhancement were obtained at the beginning and end of treatment or control therapy. A neuroradiologist blinded to the type of treatment used software to calculate the 3D volume of the pneumocephalus from the CT scans. The percentage of pneumocephalus absorption was calculated for each study participant.

Results

There was no statistically significant difference between the treatment and control groups regarding the mean initial pneumocephalus volume or time interval between CT scans. There was a significant difference (p = 0.009) between the mean rate of pneumocephalus volume reduction in the treatment (65%) and control groups (31%) per 24 hours. No patient suffered adverse effects related to treatment.

Conclusions

Administration of postsurgical supplemental O2 through a nonrebreather mask significantly increases the absorption rate of postcraniotomy pneumocephalus as compared with breathing room air.
Chemokine detection in the cerebral tissue of patients with posttraumatic brain contusions
Authors: Stefini Roberto , Catenacci Emanuela , Piva Simone , Sozzani Silvano , Valerio Alessandra , Bergomi Riccardo , Cenzato Marco , Mortini Pietro , Latronico Nicola
Published: April 2008

Object

The clinical outcome of patients with severe head injuries is still critically dependent on their secondary injuries. Although hypoxia and hypotension appear to mediate a substantial proportion of secondary injuries, many studies associate secondary brain injury with neuroinflammatory responses. Chemokines have been detected in the cerebrospinal fluid but not in the brain tissue of patients with head trauma. This study was performed to determine if chemokines were expressed in pericontusional brain tissue in patients with moderate or severe head trauma who underwent surgical evacuation of their brain contusions.

Methods

Twelve patients with posttraumatic cerebral contusion requiring a surgical evacuation were studied. A 20- to 40-mg sample of white matter was removed from the surgical cavity in the pericontusional area. Two patients undergoing elective surgery for clip ligation of an unruptured aneurysm were used as controls. The median interval from trauma to biopsy procedure was 44 hours (range 3–360 hours). Total RNA was isolated from these samples and a ribonuclease protection assay was performed to measure the mRNA levels of several chemokines: CCL2, CCL3, CCL4, CCL5, CXCL8, CXCL10, and XCL1.

Results

The CCL2, a monocyte chemoattractant produced by activated astrocytes, was the most strongly expressed chemokine, followed by CXCL8, CCL3, and CCL4. The chemokines CXCL10 and CCL5 were expressed at very low levels, and XCL1 was not detected.

Conclusions

Chemokine activation occurs early after moderate or severe head trauma and is maintained for several days after trauma. This event may contribute to neuroinflammatory exacerbation of posttraumatic brain damage in the pericontusional brain tissue.
Canine model of convection-enhanced delivery of liposomes containing CPT-11 monitored with real-time magnetic resonance imaging
Authors: Dickinson Peter J. , Lecouteur Richard A. , Higgins Robert J. , Bringas John R. , Roberts Byron , Larson Richard F. , Yamashita Yoji , Krauze Michal , Noble Charles O. , Drummond Daryl , Kirpotin Dmitri B. , Park John W. , Berger Mitchel S. , Bankiewicz Krystof S.
Published: April 2008

Object

Many factors relating to the safety and efficacy of convection-enhanced delivery (CED) into intracranial tumors are poorly understood. To investigate these factors further and establish a more clinically relevant large animal model, with the potential to investigate CED in large, spontaneous tumors, the authors developed a magnetic resonance (MR) imaging–compatible system for CED of liposomal nanoparticles into the canine brain, incorporating real-time MR imaging. Additionally any possible toxicity of liposomes containing Gd and the chemotherapeutic agent irinotecan (CPT-11) was assessed following direct intraparenchymal delivery.

Methods

Four healthy laboratory dogs were infused with liposomes containing Gd, rhodamine, or CPT-11. Convection-enhanced delivery was monitored in real time by sequential MR imaging, and the volumes of distribution were calculated from MR images and histological sections. Assessment of any toxicity was based on clinical and histopathological evaluation. Convection-enhanced delivery resulted in robust volumes of distribution in both gray and white matter, and real-time MR imaging allowed accurate calculation of volumes and pathways of distribution.

Results

Infusion variability was greatest in the gray matter, and was associated with leakage into ventricular or subarachnoid spaces. Complications were minimal and included mild transient proprioceptive deficits, focal hemorrhage in 1 dog, and focal, mild perivascular, nonsuppurative encephalitis in 1 dog.

Conclusions

Convection-enhanced delivery of liposomal Gd/CPT-11 is associated with minimal adverse effects in a large animal model, and further assessment for use in clinical patients is warranted. Future studies investigating real-time monitored CED in spontaneous gliomas in canines are feasible and will provide a unique, clinically relevant large animal translational model for testing this and other therapeutic strategies.
Polymorphisms of methionine metabolism and susceptibility to meningioma formation
Authors: Semmler Alexander , Simon Matthias , Moskau Susanna , Linnebank Michael
Published: April 2008

Object

Functionally relevant polymorphisms of methionine and folate metabolism have been shown to be associated with various human cancer entities including cerebral lymphoma and glioblastoma multiforme. The authors investigated the association of 7 functional polymorphisms of methionine metabolism with meningioma formation.

Methods

This case-controlled, monocenter association study included 290 patients of Caucasian origin undergoing surgical resection for intracranial meningioma (World Health Organization [WHO] Grade I, 190 cases; WHO Grade II, 82 cases; WHO Grade III, 18 cases) and 287 age- and sex-matched local controls. The authors analyzed the following genetic variants: dihydrofolate reductase c.594+59del19, 5,10-methylenetetrahydrofolate reductase c.677C > T and c.1298A > C, 5-methyltetrahydrofolate-homocysteine S-methyltransferase (MTR) c.2756A > G, reduced folate carrier 1 c.80G > A, cystathionine beta-synthase (CBS) c.844_855ins68 and transcobalamin 2 c.776C > G.

Results

The variant CBS c.844_855ins68—that is, the allele carrying the insertion (“ins” or “i”) as opposed to the wild-type allele designated as deletion (“del” or “d”)—was significantly overrepresented in meningioma patients (dd/ id/ii: 0.81/0.18/0.01) in comparison with the controls (dd/id/ii: 0.88/0.12/0; 2 df, chi-square 8.97, p = 0.011; multiple nominal regression with age and sex as covariables). In addition, explorative analyses revealed an association of the MTR c.2756A > G variant with meningioma WHO Grade III (AA/AG/GG: patients, 1.0/0/0; controls, 0.64/0.32/0.04; 2 df, chi-square 14.44, p = 0.001).

Conclusions

The results of this study suggest that genetic variants of methionine metabolism are associated with meningioma formation.
Use of an inflatable balloon on a catheter to prevent subdural fluid collections after intraventricular tumor surgery
Authors: Singh Lokendra , Kelkar Shailesh , Agrawal Nilesh
Published: April 2008

✓Ventricular tumor surgeries pose significant challenges to the neurosurgeon. Apart from the operative challenges and typical complications of surgery, subdural fluid collection is common after these surgeries. Various methods have been used to prevent this complication. The authors' technique of implanting an inflatable balloon attached to a catheter after resection of a huge intraventricular tumor was highly effective in preventing the development of a subdural fluid collection.
François Magendie (1783–1855) and his contributions to the foundations of neuroscience and neurosurgery
Authors: Tubbs R. Shane , Loukas Marios , Shoja Mohammadali M. , Shokouhi Ghaffar , Oakes W. Jerry
Published: April 2008

✓François Magendie lived during a tumultuous period in French history. Although this early medical pioneer made significant contributions to the fields of neuroanatomy, physiology, and pharmacology, little information is found in the non-French literature regarding this significant person in history. Based on this review, one could also consider this trained surgeon as an early pioneer of neurosurgery. For example, he is known to have used Galvanic current to treat various neuralgias, described a technique for extracting cerebrospinal fluid and quantitated and described its characteristics in normal and pathological specimens, and elucidated the functions of the the cranial nerves using vivisection. Additionally, he accurately described the functions of the dorsal and ventral rootlets using vivisection, and realized that the exposed meninges were susceptible to painful stimuli. Our current knowledge is based on the early contributions of scientists such as François Magendie.
Honoring the 75th anniversary of the American Association of Neurological Surgeons
Authors: Laws Edward R.
Published: April 2008

Ever since the Journal of Neurosurgery (JNS) published its first volume in 1944, the journal has reflected the scientific, technical, and clinical evolution of our specialty and parent organization, first called the Harvey Cushing Society and later the American Association of Neurological Surgeons. The JNS has been an uncompromising arbiter of progress in our specialty, and its superb editorial stewardship has led to its recognition as the premier journal in the field. The impact rating of JNS and its wide circulation among neurosurgeons worldwide are two of the many reasons why most of the truly innovative and paradigm-shifting advances in neurosurgery have been published in its pages.

As part of the 75th anniversary of the American Association of Neurological Surgeons celebration, the JNS Publishing Group has initiated a project of reviewing papers published over the years that have had the highest impact factor and greatest scientific interest: papers that have heralded new knowledge, new concepts, and new techniques that have been at the heart of modern neurosurgery and its continuing excitement and progress. We hope you will enjoy these articles and the accompanying commentaries. In this issue we present the next paper in this series.
Natural history of unruptured intracranial aneurysms: probability of and risk factors for aneurysm rupture
Authors: Juvela Seppo , Porras Matti , Poussa Kristiina
Published: April 2008

Object

The authors conducted a study to investigate the long-term natural history of unruptured intracranial aneurysms and the predictive risk factors determining subsequent rupture in a patient population in which surgical selection of cases was not performed.

Methods

One hundred forty-two patients with 181 unruptured aneurysms were followed from the 1950s until death or the occurrence of subarachnoid hemorrhage or until the years 1997 to 1998. The annual and cumulative incidence of aneurysm rupture as well as several potential risk factors predictive of rupture were studied using life-table analyses and Cox's proportional hazards regression models including time-dependent covariates.

The median follow-up time was 19.7 years (range 0.8–38.9 years). During 2575 person-years of follow up, there were 33 first-time episodes of hemorrhage from previously unruptured aneurysms, for an average annual incidence of 1.3%. In 17 patients, hemorrhage led to death. The cumulative rate of bleeding was 10.5% at 10 years, 23% at 20 years, and 30.3% at 30 years after diagnosis. The diameter of the unruptured aneurysm (relative risk [RR] 1.11 per mm in diameter, 95% confidence interval [CI] 1–1.23, p = 0.05) and patient age at diagnosis inversely (RR 0.97 per year, 95% CI 0.93–1, p = 0.05) were significant independent predictors for a subsequent aneurysm rupture after adjustment for sex, hypertension, and aneurysm group. Active smoking status at the time of diagnosis was a significant risk factor for aneurysm rupture (RR 1.46, 95% CI 1.04–2.06, p = 0.033) after adjustment for size of the aneurysm, patient age, sex, presence of hypertension, and aneurysm group. Active smoking status as a time-dependent covariate was an even more significant risk factor for aneurysm rupture (adjusted RR 3.04, 95% CI 1.21–7.66, p = 0.02).

Conclusions

Cigarette smoking, size of the unruptured intracranial aneurysm, and age, inversely, are important factors determining risk for subsequent aneurysm rupture. The authors conclude that such unruptured aneurysms should be surgically treated regardless of their size and of a patient's smoking status, especially in young and middle-aged adults, if this is technically possible and if the patient's concurrent diseases are not contraindications. Cessation of smoking may also be a good alternative to surgery in older patients with small-sized aneurysms.
Demographics of abusive head trauma in the Commonwealth of Pennsylvania
Authors: Kesler Henry , Dias Mark S. , Shaffer Michele , Rottmund Carroll , Cappos Kelly , Thomas Neal J.
Published: April 2008

Object

The aim of this study was to characterize the prevalence and demographic features of abusive head trauma (AHT) among infants and children < 36 months of age in Pennsylvania.

Methods

The authors included all cases of substantiated AHT involving children < 36 months of age in Pennsylvania between 1996 and 2002 that had been reported to a statewide registry. Demographic information was derived from child abuse reports and birth certificates; the study cohort was contrasted with all infants born in Pennsylvania during the same period.

Results

The study identified 327 cases. The incidence was 14.7 cases (95% confidence interval 13.1–16.5) per 100,000 person-years for the first 2 years of life with a higher incidence during the 1st year (26.0 cases per 100,000 person-years) than the 2nd year (3.4 cases per 100,000 person-years). The incidence was similar among metropolitan, non-metropolitan, and rural counties. Significantly more cases occurred during the holiday months (October–December). The median age of victims was 4.1 months. Both victims and perpetrators were more commonly male (58.4% of victims, and 70% of identified perpetrators). Compared with the entire population of Pennsylvania parents, the parents of the study cohort were more likely to be younger, less educated, and unmarried. Both mothers and fathers were more often African-American and fathers more often Hispanic. Finally, mothers more often smoked during pregnancy, sought prenatal care later in the pregnancy, and delivered low birth weight infants.

Conclusions

This population-based study of abusive head injuries throughout an entire state adds significantly to the growing knowledge about this condition. The results suggests that families of infants with abusive head injuries have significantly different demographic features compared with the general population, although which of these variables is independently significant cannot be ascertained from this study and require further investigation.
Management of lumbar shunt site swelling in children
Authors: Sood Sandeep , Gilmer-Hill Holly , Ham Steven D.
Published: April 2008

Object

The aim of this study was to define the origin and management of lumbar shunt site swelling/cerebrospinal fluid (CSF) leak seen in children who underwent placement of a percutaneous lumbar shunt due to recurrent problems with a ventricular shunt.

Methods

Fifty-seven children with a lumbar shunt were analyzed. Episodes of swelling along the lumbar shunt site, presenting symptoms, origin of the CSF leak, and surgical outcome were recorded.

Results

Twenty patients had 30 episodes of CSF leak/swelling at a mean interval of 92 ± 233 days (± standard deviation) after placement or revision. There were 7 episodes of an external CSF leak; 5 of marked swelling; and 18 episodes of headache, dizziness, and swelling. In 4 patients, the cause of CSF leakage was a fracture/disconnection or dislocation of the proximal catheter. In the remaining patients, CSF leakage was from around the proximal catheter entry point into the spinal dura (with a rate of 16.9% for placement and 15.7% for revision/reinsertion). Interlaminar removal of the existing catheter, microsurgical repair of the leak, and replacement through an opening made with the stylet of a 14-gauge Tuohy needle (Medtronic Neurosurgery) was most effective compared with percutaneous blood patch, pericatheter fascial suture, and percutaneous repositioning of the proximal catheter or downgrading valve pressure.

Conclusions

Lumbar shunt site swelling is predominantly a consequence of pericatheter CSF leakage from the mismatch in the dural opening, which corresponds to the outer diameter of the 14-gauge Tuohy needle and the smaller proximal lumbar catheter. It is best managed by direct repair of the defect through a microsurgical interlaminar approach and recannulation of the dura by using only the stylet of a 14-gauge Tuohy needle.
Diffuse intrinsic brainstem tumors in neonates
Authors: Shah Niketa C. , Ray Amit , Bartels Ute , Rutka James , Bouffet Eric , Drake James , Hawkins Cynthia E. , Huang Annie
Published: April 2008

✓ The authors report on 2 newborn infants with the unusual presentation of intrinsic brainstem tumors. Both nondysmorphic, full-term neonates had cranial nerve palsies and hypotonia. Diagnoses of diffuse intrinsic brainstem gliomas were made on the basis of magnetic resonance imaging, which showed large expansive, nonenhancing intrinsic pontine masses. Intrinsic pontine tumors, characteristically seen in school-age children, are most often high-grade gliomas that are almost invariably fatal. However, the microanatomy and natural history of pontine tumors in neonates are unknown. With parental consent, both newborns were treated expectantly with supportive care but died of progressive disease by 2 weeks of age. In one child, postmortem examination revealed a primary brainstem primitive neuroectodermal tumor. The authors conclude that, as in older children, neonatal intrinsic brainstem tumors may be of a highly malignant nature. The rapid tumor progression in both cases indicates that where a diagnostic procedure may pose significant risks, supportive observation can aid in distinguishing malignant from benign tumor growth.
Significant clinical and radiological resolution of a spinal cord syrinx following the release of a tethered cord in a patient with an anatomically normal conus medullaris
Authors: Caird John , Flynn Peter , McConnell Robert S.
Published: April 2008

✓The authors describe a case of progressive neurological deficit caused by syringomyelia in a 7-year-old boy with a normally positioned conus medullaris. This deficit responded favorably to surgical untethering of the filum terminale, with subsequent clinical and radiological improvement. The authors discuss the implications of their findings in the context of the current understanding of the pathophysiology of tethered cord syndrome, particularly in relation to the ongoing debate in the neurosurgical literature.
Gastric bypass: a risk factor for neural tube defects?
Authors: Moliterno Jennifer A. , DiLuna Michael L. , Sood Shreya , Roberts Kurt E. , Duncan Charles C.
Published: April 2008

✓ Gastric bypass surgery has become a safe and acceptable surgical weight loss treatment for individuals who suffer from morbid obesity. Patients who undergo this procedure are subject to vitamin deficiencies due to an iatrogenic malabsorptive state. Folate, a vitamin known for its role in the prevention of neural tube defects (NTDs), can be part of the deficiency spectrum resulting from this procedure. The authors describe the case of a woman who was nonadherent to multivitamin treatment after undergoing gastric bypass surgery. Her lack of understanding and appreciation of the relationship between gastric bypass surgery, folate deficiency, and NTDs may have contributed to her noncompliance with daily multivitamin consumption. As a result, her potential problems with folate absorption could have contributed to her subsequently giving birth to a child with a myelomeningocele. Thus, patient awareness and counseling along with aggressive vitamin supplementation among this particular population may help prevent the occurrence of NTDs after gastric bypass surgery.
Fetus-in-fetu in the cranium of a 4-month-old boy: histopathology and short tandem repeat polymorphism–based genotyping
Authors: Kim Jin Wook , Park Sung-Hye , Park Sung-Sup , Wang Kyu-Chang , Cho Byung-Kyu , Kim So Yeon , Ra Eun Kyung , Kim Chae-Yong , Kim Seung-Ki
Published: April 2008

✓Fetus-in-fetu is a very rare condition in which one fetus is contained within another. About 100 cases have been reported, and in most of these the fetus was located in the retroperitoneum. The authors describe an extremely rare case of an intracranial fetus-in-fetu in an extraaxial location. This is the eighth intracranial fetus-in-fetu to be reported, the first intracranial extraaxial case, and involves the oldest documented patient with this condition.

Histopathological analysis of the mass revealed a degenerated amnionic membranelike tissue, well-differentiated extremities (including fingerlike structures), skin, matured lungs, well-formed intestines, cerebellar and cerebral tissue, and a notochord with ganglion cells. DNA analysis using short tandem repeat polymorphisms confirmed that the fetus-in-fetu mass and the host infant had heterozygous alleles and were of identical sex and genotype.
Radiographic and clinical outcomes following single-level anterior cervical discectomy and allograft fusion without plate placement or cervical collar
Authors: Jagannathan Jay , Shaffrey Christopher I. , Oskouian Rod J. , Dumont Aaron S. , Herrold Christian , Sansur Charles A. , Jane John A.
Published: April 2008

Object

Although the clinical outcomes following anterior cervical discectomy and fusion (ACDF) surgery are generally good, 2 major complications are graft migration and nonunion. These complications have led some to advocate rigid internal fixation and/or cervical immobilization postoperatively. This paper examines a single-surgeon experience with single-level ACDF without use of plates or hard collars in patients with degenerative spondylosis in whom allograft was used as the fusion material.

Methods

The authors conducted a retrospective review of a prospective database of (Cloward-type) ACDF operations performed by the senior author (J.A.J.) between July 1996 and June 2005. Radiographic follow-up included static and flexion/extension radiographs obtained to assess fusion, focal and segmental kyphosis, and change in disc space height. At most recent follow-up, the patients' condition was evaluated by an independent physician examiner. The Odom criteria and Neck Disability Index (NDI) were used to assess outcome.

Results

One hundred seventy patients underwent single-level ACDF for degenerative pathology during the study period. Their most common presenting symptoms were pain, weakness, and radiculopathy; 88% of patients noted ≥ 2 neurological complaints. The mean hospital stay was 1.76 days (range 0–36 days), and 3 patients (2%) had major immediate postoperative complications requiring reoperation. The mean duration of follow-up was 22 months (range 12–124 months). Radiographic evidence of fusion was present in 160 patients (94%). Seven patients (4%) showed radiographic evidence of pseudarthrosis, and graft migration was seen in 3 patients (2%). All patients had increases in focal kyphosis at the operated level on postoperative radiographs (mean −7.4°), although segmental alignment was preserved in 133 patients (78%). Mean change in disc space height was 36.5% (range 28–53%). At most recent clinical follow-up, 122 patients (72%) had no complaints referable to cervical disease and were able to carry out their activities of daily living without impairment. The mean postoperative NDI score was 3.2 (median 3, range 0–31).

Conclusions

Single-level ACDF without intraoperative plate placement or the use of a postoperative collar is an effective treatment for cervical spondylosis. Although there is evidence of focal kyphosis and loss of disc space height, radiographic evidence of fusion is comparable to that attained with plate fixation, and the rate of clinical improvement is high.
Three-dimensional constructive interference in steady-state magnetic resonance imaging in syringomyelia: advantages over conventional imaging
Authors: Roser Florian , Ebner Florian H. , Danz Søren , Riether Felix , Ritz Rainer , Dietz Klaus , Naegele Thomas , Tatagiba Marcos S.
Published: April 2008

Object

Neuroradiology has become indispensable in detecting the pathophysiology in syringomyelia. Constructive interference in steady-state (CISS) magnetic resonance (MR) imaging can provide superior contrast at the sub-arachnoid tissue borders. As this region is critical in preoperative evaluation, the authors hypothesized that CISS imaging would provide superior assessment of syrinx pathology and surgical planning.

Methods

Based on records collected from a database of 130 patients with syringomyelia treated at the authors' institution, 59 patients were prospectively evaluated with complete neuroradiological examinations. In addition to routine acquisitions with FLAIR, T1- and T2-weighted, and contrast-enhanced MR imaging series, the authors obtained sagittal cardiac-gated sequences to visualize cerebrospinal fluid (CSF) pulsations and axial 3D CISS MR sequences to detect focal arachnoid webs. Statistical qualitative and quantitative evaluations of spinal cord/CSF contrast, spinal cord/CSF delineation, motion artifacts, and artifacts induced by pulsatile CSF flow were performed.

Results

The 3D CISS MR sequences demonstrated a contrast-to-noise ratio significantly better than any other routine imaging sequence (p < 0.001). Moreover, 3D CISS imaging can detect more subarachnoid webs and cavitations in the syrinx than T2-weighted MR imaging with less flow-void artifact. The limitation of 3D CISS imaging is a susceptibility to motion artifacts that can cause reduced spatial resolution. Lengthy acquisition times for axial segments can be reduced with multiplanar reconstruction of 3D CISS–generated sagittal images.

Conclusions

Constructive interference in steady-state imaging is the MR sequence of choice in the preoperative evaluation of syringomyelia, allowing significantly higher detection rates of focal subarachnoid webs, whereas standard T2-weighted MR imaging shows turbulent CSF flow voids. Constructive interference in steady-state MR imaging enables the neurosurgeon to accurately identify cases requiring decompression for obstructed CSF. Motion artifacts can be eliminated with technical variations.
Balloon kyphoplasty for painful C-7 vertebral hemangioma
Authors: Zapalowicz Krzysztof , Skora Piotr , Myslinski Ryszard , Karnicki Feliks , Radek Andrzej
Published: April 2008

✓The authors report on the efficacy of balloon kyphoplasty applied to obliteration of symptomatic cervical hemangioma. This 49-year-old woman suffered from progressive neck pain, numbness of the upper extremities, and frequent headaches. Hemangioma of the C-7 vertebral body was diagnosed. Kyphoplasty was performed successfully through a right anterolateral approach. The patient became asymptomatic, and follow-up examinations confirmed complete recovery. To the authors' knowledge, this is the first description of cervical hemangioma treated by balloon kyphoplasty.
Gas-filled intradural cyst with migration into the nerve root of the cauda equina
Authors: Kudo Yohei , Nishijima Yoji , Mochida Kiyoshi , Sekido Yasutomo , Tachibana Shigekuni
Published: April 2008

✓Only 4 cases of gas-filled intradural cysts of the spine have been reported previously. All cysts were due to intradural herniation of a gas-containing disc. The authors report 2 additional patients with gas-filled intradural cysts that migrated into the nerve root of the cauda equina. After surgical treatment their severe leg pain completely resolved.
Rectothecal fistula secondary to an anterior sacral meningocele
Authors: Sánchez Alvaro Arjona , Iglesias Carlos Diaz , López Cesar Díaz , Cecilia David Martínez , Gómez Jaime Alonso , Barbadillo Jose Gómez , Peña Sebastian Rufian
Published: April 2008

✓ A rectothecal fistula secondary to anterior sacral meningocele is an extremely rare disease. To the authors' knowledge, only 2 cases have been reported in the English-language literature. It can cause symptoms by compressing adjacent structures, causing urinary difficulties and constipation. The authors report an unusual case of a patient in whom this condition was diagnosed as an incidental finding. The patient had a sacral myelomeningocele with secondary meningitis to a rectothecal fistula. The authors will briefly review the diagnosis, the various treatments, and the surgical approach to treat this infrequent entity.
Partial Hepatectomy–Induced Regeneration Accelerates Reversion of Liver Fibrosis Involving Participation of Hepatic Stellate Cells
Authors: Suárez-Cuenca Juan A. , Chagoya de Sánchez Victoria , Aranda-Fraustro Alberto , Sánchez-Sevilla Lourdes , Martínez-Pérez Lidia , Hernández-Muñoz Rolando
Published: April 2008

Hepatic fibrosis underlies most types of chronic liver diseases and is characterized by excessive deposition of extracellular matrix (ECM), altered liver architecture, and impaired hepatocyte proliferation; however, the fibrotic liver can still regenerate after partial hepatectomy (PH). Therefore, the present study was aimed at addressing whether a PH-induced regeneration normalizes ECM turnover and the possible involvement of hepatic stellate cells (HSC) during resolution of a pre-established fibrosis. Male Wistar rats were rendered fibrotic by intraperitoneal administration of swine serum for 9 weeks and subjected afterwards to 70% PH or sham-operation. Histological and morphometric analyses were performed, and parameters indicative of cell proliferation, collagen synthesis and degradation, and activation of HSC were determined. Liver collagen content was reduced to 75% after PH in cirrhotic rats when compared with sham-operated cirrhotic rats. The regenerating fibrotic liver oxidized actively free proline and had diminished transcripts for α-1 (I) collagen mRNA, resulting in decreased collagen synthesis. PH also increased collagenase activity, accounted for by higher amounts of pro-MMP-9, MMP-2, and MMP-13, which largely coincided with a lower expression of TIMP-1 and TIMP-2. Therefore, an early decreased collagen synthesis, mild ECM degradation, and active liver regeneration were followed by higher collagenolysis and limited deposition of ECM, probably associated with increased mitochondrial activity. Activated HSC readily increased during liver fibrosis and remained activated after liver regeneration, even during fibrosis resolution. In conclusion, stimulation of liver regeneration through PH restores the balance in ECM synthesis/degradation, leading to ECM remodeling and to an almost complete resolution of liver fibrosis. As a response to the regenerative stimulus, activated HSC seem to play a controlling role on ECM remodeling during experimental cirrhosis in rats. Therefore, pharmacological approaches for the resolution of liver fibrosis by blocking HSC activation should also evaluate possible effects on liver cell proliferation.
Measurement Techniques for Cellular Biomechanics In Vitro
Authors: Addae-Mensah Kweku A. , Wikswo John P.
Published: April 2008

Living cells and tissues experience mechanical forces in their physiological environments that are known to affect many cellular processes. Also of importance are the mechanical properties of cells, as well as the microforces generated by cellular processes themselves in their microenvironments. The difficulty associated with studying these phenomena in vivo has led to alternatives such as using in vitro models. The need for experimental techniques for investigating cellular biomechanics and mechanobiology in vitro has fueled an evolution in the technology used in these studies. Particularly noteworthy are some of the new biomicroelectromechanical systems (Bio-MEMS) devices and techniques that have been introduced to the field. We describe some of the cellular micromechanical techniques and methods that have been developed for in vitro studies, and provide summaries of the ranges of measured values of various biomechanical quantities. We also briefly address some of our experiences in using these methods and include modifications we have introduced in order to improve them.