bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitral Valve Prolapse Syndrome and Magnesium Supplementation: A Review of the Literature
Authors: Scordo Kristine A.
Published: January 2009

Mitral valve prolapse (MVP) is the most common valvular heart disease frequently associated with a constellation of symptoms unrelated to structural valvular changes. Patients’ self-reports reflect a variety of frightening symptoms, including chest pain, shortness of breath, palpitations, migraine headaches, lightheadedness, fatigue, dizziness on standing, mood swings, and anxiety or panic attacks. Individuals with these symptoms repeatedly seek help in emergency rooms, urgent care centers, and primary care offices, contributing to the economic burden of health care. Treatment measures are directed toward symptom relief. Although traditional medications such as beta-adrenergic blockers, calcium channel blockers, and anxiolytics are widely used to treat MVP symptoms, these medications are reportedly ineffective for many people. An appreciable number use one or more alternative therapies to control symptoms—most notable among these are magnesium supplements, which are known to influence cardiac function. This article’s purpose is to review the literature on what is known about MVP syndrome and magnesium supplementation.
Patterns of macroinvertebrate assemblages in a long-term watershed-scale study to address the effects of pulp and paper mill discharges in four us receiving streams
Authors: Flinders Camille A , Minshall G Wayne , Ragsdale Renee L , Hall Timothy J
Published: January 2009

Changes in macroinvertebrate communities exposed to pulp and paper mill effluent (PPME) have been seen in mesocosm and short-term field studies. However, long-term patterns of macroinvertebrates in PPME receiving streams have not been examined. We conducted a study of 4 PPME receiving streams (Codorus Creek, PA; the Leaf River, MS; and the McKenzie and Willamette rivers, OR) over 9 y to assess temporal patterns in macroinvertebrate community structure and metrics related to PPME discharge. Study streams represented different ecoregions, warm-/cold-water systems, gradients of PPME concentration (<1%-33%), and mill process types. Bray-Curtis similarity and nonmetric multidimensional scaling showed significant community differences across sites in Codorus Creek, but differences were related to stream temperature patterns and not PPME. In the other study streams, seasonal community differences across years were greater than differences across sites. General linear models were used to examine spatial and temporal variation in macroinvertebrate metric response (% dominant taxa, density, richness, Hilsenhoff Biotic Index [HBI], Simpson's Index, and ash-free dry mass). Mean HBI scores indicated that the macroinvertebrate community reflected fair to very good water quality conditions, with water quality typically classified as “good” at most sites. Significant site differences in macroinvertebrate metric response were uncommon in the Leaf, McKenzie, and Willamette rivers but were seen in all metrics in Codorus Creek, where metric response was spatially variable. In the McKenzie River, there was an increase in mean HBI scores at sites downstream of the mill relative to 1 of the 2 upstream sites. However, significant differences were seen only between 1 upstream and downstream site, and HBI scores at all downstream sites consistently reflected “good” water quality. Significant annual differences in metric response were typical in all rivers. Water quality (pH, conductivity, total nitrogen) and habitat (velocity, depth, substrate composition) variables explained community structure patterns in the Leaf and McKenzie rivers, but macroinvertebrate-environment relationships were weak in the other 2 streams. The results of this study indicate that macroinvertebrate community structure is temporally variable and reiterate the importance of long-term studies for accurate determination of the effects of point sources such as PPME on receiving systems.
Nucleotide structure and expression of equine pigment epithelium-derived factor during repair of experimentally induced wounds in horses
Authors: Ipiña Zoë , Lussier Jacques G. , Theoret Christine L.
Published: January 2009

Objective—To clone full-length equine pigment epithelium-derived factor (PEDF) complementary DNA (cDNA) and to evaluate its temporal expression during repair of wounds in horses.

Animals—4 clinically normal 2-to 3-year-old Standardbred mares.

Procedures—Full-length equine PEDF cDNA was cloned by screening size-selected cDNA libraries derived from biopsy specimens obtained from the wound edge 7 days after experimental creation of a 6.25-cm2 full-thickness wound in the skin of the lateral thoracic wall. Expression was evaluated in normal skin and in biopsy specimens obtained weekly from experimentally induced wounds on the trunk and limbs of horses. Temporal gene expression was determined by use of reverse transcriptase PCR assay.

Results—Equine PEDF shared 87% sequence and 88% peptide homology with human PEDF. Wounding caused upregulation of PEDF mRNA, which did not return to baseline by the end of the study in either anatomic location. Relative overexpression was evident in wounds on the trunk, compared with expression for wounds on the limbs.

Conclusions and Clinical Relevance—This study characterized full-length equine cDNA for PEDF and determined that the gene for PEDF appeared to be upregulated in response to dermal wounding. Although the cause of exuberant granulation tissue is probably multifactorial, these data suggested that PEDF, via its potent antiangiogenic capabilities, may contribute to superior healing in wounds on the trunks of horses by protecting such wounds from excessive formation of vascular granulation tissue that characterizes wounds on the limbs of this species.
Vascular perfusion of reproductive organs in pony mares and heifers during sedation with detomidine or xylazine
Authors: Araujo Reno R. , Ginther O. J.
Published: January 2009

Objective—To assess the vascular effects of detomidine and xylazine in pony mares and heifers, respectively, as determined in a major artery and by extent of vascular perfusion of reproductive organs.

Animals—10 pony mares and 10 Holstein heifers.

Procedures—Pony mares were assigned to receive physiologic saline (0.9% NaCl) solution (n = 5) or detomidine (3.0 mg/mare, IV; 5). Heifers were assigned to receive saline solution (5) or xylazine (14 mg/heifer, IM; 5). Color Doppler ultrasonographic examinations were performed immediately before and 10 minutes after administration of saline solution or sedative. In spectral Doppler mode, a spectral graph of blood flow velocities during a cardiac cycle was obtained at the internal iliac artery and at the ovarian pedicle. In color-flow mode, color signals of blood flow in vessels of the corpus luteum and endometrium were assessed.

Results—Systemic effects of sedation in the 2 species were evident as a decrease in heart rate; increase in duration of systole, diastole, or both; decrease in volume of blood flow; and decrease in velocity of blood flow within the internal iliac artery. However, an effect of sedatives on local vascular perfusion in the ovaries and endometrium was not detected.

Conclusions and Clinical Relevance—Sedation with detomidine in pony mares and xylazine in heifers did not affect vascular perfusion in reproductive organs. These sedatives can be used in experimental and clinical color Doppler evaluations of vascular perfusion of the corpus luteum and endometrium.
Use of dietary cation anion difference for control of urolithiasis risk factors in goats
Authors: Jones Meredyth L. , Streeter Robert N. , Goad Carla L.
Published: January 2009

Objective—To determine correlations between dietary cation anion difference (DCAD) and urine pH, urine specific gravity, and blood pH in goats.

Animals—24 crossbred goat wethers. Procedures—Goats were randomly assigned to 1 of 4 DCAD groups (−150, −75, 0, or +75 mEq/kg of feed) and fed pelleted feed and ground hay for 7 days. The diet was then supplemented with ammonium chloride to achieve the assigned DCAD of each group for 7 days. Urine was obtained for pH and specific gravity measurements at hours −3 to −1, 1 to 3, 5 to 7, 9 to 11, and 13 to 15 relative to the morning feeding. Blood pH was determined on alternate days of the study period.

Results—Goats in the −150 and −75 mEq/kg groups had a urine pH of 6.0 to 6.5 two days after initiation of administration of ammonium chloride, and urine pH decreased to < 6.0 by day 7. Goats in the 0 mEq/kg group had a urine pH from 6.0 to 6.5 on day 5, whereas urine pH in goats in the +75 mEq/kg group remained > 6.5 throughout the trial. Urine specific gravity differed only between the −150 mEq/kg and the −75 mEq/kg groups. Blood pH in the −150 mEq/kg group was significantly lower than that in the other groups. Conclusions and Clinical Relevance—Goats in the 0 mEq/kg DCAD group had a urine pH of 6.0 to 6.5 five days after intitiation of feeding the diet, and that pH was maintained through day 7, without significant reduction in blood pH. This may serve as a target for diet formulation for the prevention of urolithiasis.
Use of tick surveys and serosurveys to evaluate pet dogs as a sentinel species for emerging Lyme disease
Authors: Hamer Sarah A. , Tsao Jean I. , Walker Edward D. , Mansfield Linda S. , Foster Erik S. , Hickling Graham J.
Published: January 2009

Objective—To evaluate dogs as a sentinel species for emergence of Lyme disease in a region undergoing invasion by Ixodes scapularis.

Sample Population—353 serum samples and 78 ticks obtained from dogs brought to 18 veterinary clinics located in the lower peninsula of Michigan from July 15, 2005, through August 15, 2005.

Procedures—Serum samples were evaluated for specific antibodies against Borrelia burgdorferi by use of 3 serologic assays. Ticks from dogs were subjected to PCR assays for detection of pathogens.

Results—Of 353 serum samples from dogs in 18 counties in 2005, only 2 (0.6%) contained western blot analysis–confirmed antibodies against B burgdorferi. Ten of 13 dogs with I scapularis were from clinics within or immediately adjacent to the known tick invasion zone. Six of 18 I scapularis and 12 of 60 noncompetent vector ticks were infected with B burgdorferi. No ticks were infected with Anaplasma phagocytophilum, and 3 were infected with Babesia spp.

Conclusions and Clinical Relevance—Serosurvey in dogs was found to be ineffective in tracking early invasion dynamics of I scapularis in this area. Tick chemoprophylaxis likely reduces serosurvey sensitivity in dogs. Ticks infected with B burgdorferi were more common and widely dispersed than seropositive dogs. In areas of low tick density, use of dogs as a source of ticks is preferable to serosurvey for surveillance of emerging Lyme disease. Impact for Human Medicine—By retaining ticks from dogs for identification and pathogen testing, veterinarians can play an important role in early detection in areas with increasing risk of Lyme disease.
Evaluation of immunohistochemical detection of prion protein in rectoanal mucosa–associated lymphoid tissue for diagnosis of scrapie in sheep
Authors: Dennis Michelle M. , Thomsen Bruce V. , Marshall Katherine L. , Hall S. Mark , Wagner Bruce A. , Salman Mo D. , Norden Dianne K. , Gaiser Charles , Sutton Diane L.
Published: January 2009

Objective—To determine the suitability and estimate the sensitivity of an immunohistochemical (IHC) test for disease-associated prion protein (PrPSc) in biopsy specimens of rectoanal mucosa–associated lymphoid tissue (RAMALT) for diagnosis of scrapie in sheep.

Animals—762 sheep at high risk for having scrapie and indemnified by the National Scrapie Eradication Program.

Procedures—The IHC test for PrPSc was applied to 2 RAMALT and 2 third-eyelid biopsy specimens and a postmortem RAMALT specimen from each sheep. Results were compared with those of a reference test in which results for tissues from obex and retropharyngeal lymph nodes, tonsil, or both were considered in parallel.

Results—The reference test identified 139 sheep as having scrapie. Biopsy-related complications occurred in 3 sheep. Sensitivity of the IHC test in RAMALT ranged from 85.3% to 89.4%, depending on the anatomic location from which RAMALT was obtained. Results for the test applied to 1 RAMALT specimen were similar to results interpreted in parallel for 2 third-eyelid specimens (sensitivity, 87.0%). The proportion of inconclusive test results attributable to insufficient lymphoid follicles in biopsy specimens was lower when considering results for 2 RAMALT specimens in parallel (10.1%) than when considering results for 2 third-eyelid specimens in parallel (23.7%). Specimens of RAMALT that were inappropriately collected from an area caudal to the rectoanal interface yielded a high proportion of inconclusive results (33.3% to 50.0%).

Conclusions and Clinical Relevance—The IHC test for PrPSc in RAMALT was an effective means of detecting subclinical scrapie in live, high-risk sheep.
Assessment of viremia associated with experimental primary feline herpesvirus infection or presumed herpetic recrudescence in cats
Authors: Westermeyer Hans D. , Thomasy Sara M. , Kado-Fong Helen , Maggs David J.
Published: January 2009

Objective—To detect feline herpesvirus type 1 (FHV-1) in blood of cats undergoing experimental primary herpetic disease or with spontaneous disease presumed to be caused by FHV-1 reactivation.

Animals—6 young specific-pathogen–free (SPF) cats and 34 adult cats from a shelter.

Procedures—Conjunctiva and nares of SPF cats were inoculated with FHV-1, and cats were monitored for 21 days. Periodically, blood was collected for CBC, serum biochemical analyses, and detection of FHV-1 DNA via PCR assay. For shelter cats, a conjunctival swab specimen was collected for FHV-1 PCR assay, and blood mononuclear cells were tested via virus isolation (with or without hydrocortisone) and FHV-1 PCR assay.

Results—All SPF cats developed clinical and clinicopathologic evidence of upper respiratory tract and ocular disease only. Via PCR assay, FHV-1 DNA was detected in blood of all SPF cats at least once between 2 and 15 days after inoculation. Feline herpesvirus type 1 DNA was detected in conjunctival swabs of 27 shelter cats; 25 had clinical signs of herpetic infection. However, virus was not isolated from mononuclear cell samples of any shelter cat regardless of passage number or whether hydrocortisone was present in the culture medium; FHV-1 DNA was not detected in any mononuclear cell sample collected from shelter cats.

Conclusions and Clinical Relevance—A brief period of viremia occurred in cats undergoing primary herpetic disease but not in cats undergoing presumed recrudescent herpetic disease. Viremia may be important in the pathogenesis of primary herpetic disease but seems unlikely to be associated with recrudescent disease.
Association of periodontal disease, oral procedures, and other clinical findings with bacterial endocarditis in dogs
Authors: Peddle Gordon D. , Drobatz Kenneth J. , Harvey Colin E. , Adams Allison , Sleeper Meg M.
Published: January 2009

Objective—To identify risk factors potentially associated with the development of bacterial endocarditis in dogs and determine whether periodontal disease and surgical procedures (oral and nonoral) were associated with bacterial endocarditis.

Design—Retrospective case-control study.

Animals—76 dogs with (cases) and 80 dogs without (controls) bacterial endocarditis.

Procedures—Medical records were reviewed for information on signalment, physical examination findings, recent medical history, and results of echocardiography, clinicopatho- logic testing, and necropsy.

Results—None of the dogs with endocarditis had a history of undergoing any dental or oral procedure in the 3 months prior to the diagnosis of endocarditis, and no significant difference was found between groups with regard to the prevalence of oral infection. Dogs with endocarditis were significantly more likely to have undergone a nonoral surgical procedure that required general anesthesia in the preceding 3 months or to have developed a new heart murmur or a change in intensity of an existing heart murmur. Preexisting cardiac dis-ease (congenital or acquired) was not found to be a risk factor.

Conclusions and Clinical Relevance—Results did not provide any evidence of an association between bacterial endocarditis in dogs and either dental or oral surgical procedures or oral infection. Findings suggested that the routine use of prophylactic antimicrobial administration in dogs undergoing oral procedures needs to be reevaluated.
Evaluation of allele frequencies of inherited disease genes in subgroups of American Quarter Horses
Authors: Tryon Robert C. , Penedo M. Cecilia T. , McCue Molly E. , Valberg Stephanie J. , Mickelson James R. , Famula Thomas R. , Wagner Michelle L. , Jackson Mark , Hamilton Michael J. , Nooteboom Sabine , Bannasch Danika L.
Published: January 2009

Objective—To estimate allele frequencies of the hyperkalaemic periodic paralysis (HYPP), lethal white foal syndrome (LWFS), glycogen branching enzyme deficiency (GBED), hereditary equine regional dermal asthenia (HERDA), and type 1 polysaccharide storage myopathy (PSSM) genes in elite performance subgroups of American Quarter Horses (AQHs).

Design—Prospective genetic survey.

Animals—651 elite performance AQHs, 200 control AQHs, and 180 control American Paint Horses (APHs).

Procedures—Elite performance AQHs successful in 7 competitive disciplines (barrel racing, cutting, halter, racing, reining, western pleasure, and working cow horse) were geno- typed for 5 disease-causing alleles. Age-matched control AQHs and APHs were used to establish comparative whole-breed estimates of allele frequencies.

Results—Highest allele frequencies among control AQHs were for type 1 PSSM (0.055) and GBED (0.054), whereas HERDA (0.021) and HYPP (0.008) were less prevalent. Control APHs uniquely harbored LWFS (0.107) and had high prevalence of HYPP (0.025), relative to AQHs. Halter horse subgroups had significantly greater allele frequencies for HYPP (0.299) and PSSM (0.155). Glycogen branching enzyme deficiency, HERDA, and PSSM were found broadly throughout subgroups; cutting subgroups were distinct for HERDA (0.142), and western pleasure subgroups were distinct for GBED (0.132). Racing and barrel racing subgroups had the lowest frequencies of the 5 disease genes.

Conclusions and Clinical Relevance—Accurate estimates of disease-causing alleles in AQHs and APHs may guide use of diagnostic genetic testing, aid management of genetic diseases, and help minimize production of affected foals.
Contrast harmonic ultrasonography of splenic masses and associated liver nodules in dogs
Authors: Ivančić Marina , Long Fenella , Seiler Gabriela S.
Published: January 2009

Objective—To determine whether contrast harmonic ultrasonography (CHUS) can be used in dogs to distinguish splenic hemangiosarcoma from hematoma and to accurately detect and characterize liver nodules.

Design—Cross-sectional study.

Animals—20 dogs with a splenic mass.

Procedures—Routine abdominal ultrasonography was followed by CHUS of hepatic and splenic lesions. Qualitative evaluation included location, enhancement pattern, and vascularity of lesions. Quantitative evaluation included peak mean pixel intensity, interval to peak intensity, area under the curve (spleen), and liver-to-lesion intensity ratio (liver). Histologic findings were compared with CHUS lesion characteristics.

Results—Histologic evaluation of the spleen was performed in 19 dogs, resulting in diagnoses of hemangiosarcoma (n = 11), hematoma (7), and undifferentiated sarcoma (1). Benign and malignant processes in the spleen were indistinguishable via CHUS. Histologic evaluation of the liver was performed in 18 dogs, resulting in a diagnosis of hemangiosarcoma in 5 dogs. None of the dogs with splenic hematomas had evidence of hepatic lesions by means of con-ventional or contrast ultrasonography, and none had histologic evidence of liver metastases. In 3 of 18 dogs, isoenhancing liver nodules were detected and all were histologically benign. Five dogs had liver nodules that remained hypoechoic after contrast agent was injected; all had histologic evidence of metastatic hemangiosarcoma. Results of CHUS were used to characterize hepatic metastases with 100% sensitivity and specificity.

Conclusions and Clinical Relevance—Contrast harmonic ultrasonography was a noninvasive and accurate means of differentiating metastatic versus benign hepatic disease in dogs with splenic hemangiosarcoma but was not useful in distinguishing splenic hemangiosarcoma from hematoma.
Cercarial dimensions and surface structures as a tool for species determination of Trichobilharzia spp.
Authors: Podhorský Martin , Huůzová Zuzana , Mikeš Libor , Horák Petr
Published: January 2009

Cercariae of bird schistosomes are traditionally considered to be very similar in their morphological characteristics. In order to solve the problem, we tested some methods which might be suitable for cercarial differentiation. Fourteen isolates of three Trichobilharzia species (T. szidati, T. franki, T. regenti) occurring sympatrically in Central Europe were used. Dimensions of individual cercariae do not represent a useful criterion for identification, because the intraspecific variability exceeds the interspecific one. On the other hand, chaetotaxy appears a promising way for discrimination, although some sensory papillae do not stain sufficiently with silver nitrate. The papillary pattern (i.e. number and relative position of papillae) is specific for all Trichobilharzia species studied by us. Therefore, we compiled an identification key for the three Trichobilharzia species. In addition, we tried to find species-specific surface saccharide epitopes; none of the labeled lectin probes can be used as a speciesspecific marker.
The configuration polytope of ℓ-line configurations in Steiner triple systems
Authors: Colbourn Charles
Published: January 2009

It has been shown that the number of occurrences of any ℓ-line configuration in a Steiner triple system can be written as a linear combination of the numbers of full m-line configurations for 1 ≤ m ≤ ℓ; full means that every point has degree at least two. More precisely, the coefficients of the linear combination are ratios of polynomials in v, the order of the Steiner triple system. Moreover, the counts of full configurations, together with v, form a linear basis for all of the configuration counts when ℓ ≤ 7. By relaxing the linear integer equalities to fractional inequalities, a configuration polytope is defined that captures all feasible assignments of counts to the full configurations. An effective procedure for determining this polytope is developed and applied when ℓ = 6. Using this, minimum and maximum counts of each configuration are examined, and consequences for the simultaneous avoidance of sets of configurations explored.
Cliques in Steiner systems
Authors: Dudek Andrzej , Franěk František , Rödl Vojtěch
Published: January 2009

A partial Steiner (k,l)-system is a k-uniform hypergraph with the property that every l-element subset of V is contained in at most one edge of . In this paper we show that for given k,l and t there exists a partial Steiner (k,l)-system such that whenever an l-element subset from every edge is chosen, the resulting l-uniform hypergraph contains a clique of size t. As the main result of this note, we establish asymptotic lower and upper bounds on the size of such cliques with respect to the order of Steiner systems.
ABC Surgical Risk Scale for skull base meningioma: a new scoring system for predicting the extent of tumor removal and neurological outcome
Authors: Adachi Kazuhide , Kawase Takeshi , Yoshida Kazunari , Yazaki Takahito , Onozuka Satoshi
Published: January 2009

Object

Surgery for skull base meningiomas (SBMs) can lead to complications because these lesions are difficult to approach and can involve cranial nerves and arteries. The authors propose a scoring system to evaluate the relative risks and benefits of surgical treatment of SBMs.

Methods

The authors used a 2-step process to construct their scale. First, they derived significant predictive variables from retrospective data on 132 SBM cases treated surgically (primary surgeries only) between May 2000 and December 2005. Next, they validated the predictive accuracy of their scoring system in 60 consecutive cases treated surgically between January 1995 and April 2000, including both primary and repeated surgeries. Finally, they investigated the effect of the surgery on the patients' preoperative symptoms for consecutive cases treated surgically between January 1995 and December 2005, including both primary surgeries and retreatments.

Results

Five items that predicted surgical risk were identified: 1) tumor attachment size; 2) arterial involvement; 3) brainstem contact; 4) central cavity location; and 5) cranial nerve group involvement. The authors named their scoring system the ABC Surgical Risk Scale, after the initial letters of these items. Each factor was assigned a score of 0–2 points, and an additional point was added for previous surgical treatment or for radiation, giving a possible total score of 12 points. On average, the scoring system allocated 2 points for gross-total resections, 6.1 points for near-total resections, and 9 points for subtotal resections, with significant differences between groups. For cases scoring ≥ 8 points, the percentage of cases showing neurological deterioration postoperatively exceeded the percentage showing improvement.

Conclusions

The authors conclude that this scoring system can be used to predict the extent of tumor removal and that the scores reflect the surgical risk.
Decompressive craniectomy in children with nontraumatic refractory high intracranial pressure
Authors: Aghakhani Nozar , Durand Philippe , Chevret Laurent , Parker Fabrice , Devictor Denis , Tardieu Marc , Tadié Marc
Published: January 2009

Object

In this study, the authors investigated the clinical efficacy of decompressive craniectomy treatments for nontraumatic intracranial hypertension in children.

Methods

Seven patients with nontraumatic refractory high intracranial pressure (ICP) were enrolled in the study between 1995 and 2005; there were 2 boys and 5 girls with a mean age of 9 years (range 4–14). Decompressive craniectomy was performed in all patients after standard medical therapy had proven insufficient and ICP remained > 50 mm Hg. All patients had a Glasgow Coma Scale score < 8 at admission and a mean Pediatric Risk of Mortality Scale score of 20 (range 10–27).

Results

One patient died of persistent high ICP and circulatory failure 48 hours after surgery. Six months later, according to their Glasgow Outcome Scale scores, 3 patients had adequate recoveries, 2 patients recovered with moderate disabilities, and 1 patient had severe disabilities. According to the Pediatric Overall Performance Category Scale, 4 patients received a score of 2 (mild disability), 1 a score of 3 (moderate disability), and 1 a score of 4 (severe disability). Five patients returned to school and normal life.

Conclusions

The authors found decompressive craniectomy to be an effective and lifesaving technique in children. This procedure should be included in the arsenal of treatments for nontraumatic intracranial hypertension.
Computed tomography morphometric analysis for C-1 lateral mass screw placement in children
Authors: Chamoun Roukoz B. , Whitehead William E. , Curry Daniel J. , Luerssen Thomas G. , Jea Andrew
Published: January 2009

Object

The use of C-1 lateral mass screws provides an alternative to C1–2 transarticular screws in the pediatric population. However, the confined space of the local anatomy and unfamiliarity with the technique may make the placement of a C-1 lateral mass screw more challenging, especially in the juvenile or growing spine.

Methods

A CT morphometric analysis was performed in 76 pediatric atlases imaged at Texas Children's Hospital from October 1, 2007 until April 30, 2008. Critical measurements were determined for potential screw entry points, trajectories, and lengths, with the goal of replicating the operative technique described by Harms and Melcher for adult patients.

Results

The mean height and width for screw entry on the posterior surface of the lateral mass were 2.6 and 8.5 mm, respectively. The mean medially angled screw trajectory from an idealized entry point on the lateral mass was 16° (range 4 to 27°). The mean maximal screw depth from this same ideal entry point was 20.3 mm. The overhang of the posterior arch averaged 6.3 mm (range 2.1–12.4 mm). The measurement between the left- and right-side lateral masses was significantly different for the maximum medially angled screw trajectory (p = 0.003) and the maximum inferiorly directed angle (p = 0.045). Those measurements in children < 8 years of age were statistically significant for the entry point height (p = 0.038) and maximum laterally angled screw trajectory (p = 0.025) compared with older children. The differences between boys and girls were statistically significant for the minimum screw length (p = 0.04) and the anterior lateral mass height (p < 0.001).

Conclusions

A significant variation in the morphological features of C-1 exists, especially between the left and right sides and in younger children. The differences between boys and girls are clinically insignificant. The critical measurement of whether the C-1 lateral mass in a child could accommodate a 3.5-mm-diameter screw is the width of the lateral mass and its proximity to the vertebral artery. Only 1 of 152 lateral masses studied would not have been able to accommodate a lateral mass screw. This study reemphasizes the importance of a preoperative CT scan of the upper cervical spine to assure safe and effective placement of the instrumentation at this level.
Aggressive variant of a papillary glioneuronal tumor
Authors: Javahery Ramin J. , Davidson Laurence , Fangusaro Jason , Finlay Jonathan L. , Gonzalez-Gomez Ignacio , McComb J. Gordon
Published: January 2009

Papillary glioneuronal tumors are a newly recognized type of brain neoplasm characterized by prominent pseudopapillary structures and glioneuronal elements. All prior cases have shown that these tumors have an indolent course. The authors present 2 patients with an aggressive variant of the tumor. The first patient had dissemination of her tumor and the second had local spreading. Therefore, the authors conclude that papillary glioneuronal tumors do not always behave in a strictly benign fashion.
Jefferson fractures of the immature spine
Authors: AuYong Nicholas , Piatt Joseph
Published: January 2009

Jefferson fractures of the immature spine have received little attention in the study of pediatric spinal trauma. Fractures through synchondroses are a possibility in the immature spine, in addition to fractures through osseous portions of the vertebral ring, and they create opportunities for misinterpretation of diagnostic imaging. The authors describe 3 examples of Jefferson fractures in young children. All 3 cases featured fractures through an anterior synchondrosis in association with persistence of the posterior synchondrosis or a fracture of the posterior arch. The possibility of a Jefferson fracture should be considered for any child presenting with neck pain, cervical muscle spasm, or torticollis following a head injury, despite a seemingly normal cervical spine study. Jefferson fractures in young children are probably much more common than previously recognized.
An analysis of general surgery–related complications in a series of 412 minilaparotomic anterior lumbosacral procedures
Authors: Kang Byung-Uk , Choi Won-Chul , Lee Sang-Ho , Jeon Sang Hyeop , Park Jong Dae , Maeng Dae Hyeon , Choi Young-Geun
Published: January 2009

Object

Anterior lumbar surgery is associated with certain perioperative visceral and vascular complications. The aim of this study was to document all general surgery–related adverse events and complications following minilaparotomic retroperitoneal lumbar procedures and to discuss strategies for their management or prevention.

Methods

The authors analyzed data obtained in 412 patients who underwent anterior lumbosacral surgery between 2003 and 2005. The series comprised 114 men and 298 women whose mean age was 56 years (range 34–79 years). Preoperative diagnoses were as follows: isthmic spondylolisthesis (32%), degenerative spondylolisthesis (24%), instability/stenosis (15%), degenerative disc disease (15%), failed–back surgery syndrome (7%), and lumbar degenerative kyphosis or scoliosis (7%). A single level was exposed in 264 patients (64%), 2 in 118 (29%), and 3 or 4 in 30 (7%). The average follow-up period was 16 months.

Results

Overall, 52 instances of complications and adverse events occurred in 50 patients (12.1%), including sympathetic dysfunction in 25 (6.06%), vascular injury repaired with/without direct suture in 12 (2.9%), ileus lasting > 3 days in 5 (1.2%), pleural effusion in 4 (0.97%), wound dehiscence in 2 (0.49%), symptomatic retroperitoneal hematoma in 2 (0.49%), angina in 1 (0.24%), and bowel laceration in 1 patient (0.24%). There was no instance of retrograde ejaculation in male patients, and most complications had no long-term sequelae.

Conclusions

This report presents a detailed analysis of complications related to anterior lumbar surgery. Although the incidence of complications appears low considering the magnitude of the procedure, surgeons should be aware of these potential complications and their management.
Long-term result of the Echols procedure for treating syringomyelia
Authors: Peterson Matthew M. , Craciun Liviu , Heiss John D.
Published: January 2009

In 1974, a 9-year-old girl with syringomyelia and scoliosis was treated using the Echols procedure, a surgical technique that makes use of a metal stent to maintain drainage of fluid from the syrinx into the subarachnoid space. The patient presented to the authors' institution 34 years later with a history of progressive myelopathy and surgically treated deformities of the thoracic spine, lumbar spine, and right foot. Computer-assisted myelography indicated that the metal wire remained in place and that the syrinx had collapsed. Neurological examination and neurophysiological testing confirmed the presence of thoracic myelopathy, which may have been due to the wire tethering the thoracic spinal cord to the dorsal dura. This case is believed to be the only long-term report of the effects of the Echols procedure. The history of direct treatment of syringomyelia is reviewed and is contrasted with indirect treatment of syringomyelia, which relieves the condition by opening obstructed CSF pathways within the foramen magnum or spine.
Placement of thoracolumbar pedicle screws using three-dimensional image guidance: experience in a large patient cohort
Authors: Nottmeier Eric W. , Seemer Will , Young Phillip M.
Published: January 2009

Object

The goal of this study was to analyze the placement accuracy and complications of thoracolumbar pedicle screws (PSs) inserted using 3D image guidance in a large patient cohort.

Methods

The authors reviewed the charts of 220 consecutive patients undergoing posterior spinal fusion using 3D image guidance for instrumentation placement. A total of 1084 thoracolumbar PSs were placed using either the BrainLAB Vector Vision (BrainLAB, Inc.) or Medtronic StealthStation Treon (Medtronic, Inc.) image guidance systems. Postoperative CT scanning was performed in 184 patients, allowing for 951 screws to be graded by an independent radiologist for bone breach. All complications resulting from instrumentation placement were noted. Using the intraoperative planning function of the image-guided system, the largest diameter screw possible in each particular case was placed. The screw diameter of instrumentation placed into the L3–S1 levels was noted.

Results

No vascular or visceral complications occurred as a result of screw placement. Two nerve root injuries occurred in 1084 screws placed, resulting in a 0.2% per screw incidence and a 0.9% patient incidence of nerve root injury. Neither nerve root injury was associated with a motor deficit. The breach rate was 7.5%. Grade 1 and minor anterolateral “tip out” breaches accounted for 90% of the total breaches. Patients undergoing revision surgery accounted for 46% of the patients in this study. Accordingly, 154 screws placed through previous fusion mass could be evaluated using postoperative CT scanning. The breach rate in this specific cohort was 7.8%. A total of 765 PSs were placed into the L3–S1 levels in this study; 546 (71%) of these screws were ≥ 7.5 mm in diameter. No statistical difference in breach rate was noted in PSs placed through revision spinal levels versus nonrevision spinal levels (p = 0.499). Additionally, no increase in breach rate was noted with placement of 7.5-mm-diameter screws.

Conclusions

Three-dimensional image guidance is a useful adjunct to placement of spinal instrumentation. The complication rate in this study was low, and accurate placement of instrumentation was achieved despite the high percentage of revision surgery cases in our patient population. Additionally, because active fluoroscopy was not used for instrumentation placement, there was minimal to no radiation exposure to the surgeon or operating room staff.
Role of hyperbaric oxygen therapy in the treatment of bacterial spinal osteomyelitis
Authors: Ahmed Raheel , Severson Meryl A. , Traynelis Vincent C.
Published: January 2009

Object

Hyperbaric oxygen therapy (HBO) is used as primary and/or adjunctive therapy in the treatment of various clinical conditions complicated by local hypoxia. It may have therapeutic potential in the treatment of neurosurgical infections such as spinal osteomyelitis that are associated with significant morbidity rates. The purpose of this study was to evaluate the efficacy of HBO therapy in the treatment of spinal osteomyelitis.

Methods

The clinical records of patients diagnosed with spinal osteomyelitis who received HBO therapy during their treatment at the authors' institution over the past 10 years were retrospectively reviewed. Six adult patients were identified. Four patients had recently undergone spinal surgery and secondary spinal osteomyelitis had developed. These patients received adjunctive HBO therapy due to significant comorbidities and risk factors for poor healing.

Results

All patients remained symptom and infection free over the subsequent follow-up period. Two patients had primary spinal osteomyelitis that had recurred despite a full course of appropriate antimicrobial therapy. Infection control was achieved after HBO therapy in 1 patient. The mean follow-up period for the study group was 2.9 years (range 5 months to 5 years).

Conclusions

Hyperbaric oxygen therapy enabled infection cure in 5 of 6 patients with spinal osteomyelitis complicated by medical comorbidities or the failure of primary therapy. These results show that HBO may be a useful adjunctive therapeutic modality in the treatment of spinal osteomyelitis, particularly when there are medical comorbidities that increase the risk of poor healing. Hyperbaric oxygen therapy may also be beneficial in patients with relapsing primary spinal osteomyelitis after standard therapy has failed.
Feasibility and potential value of flat-panel detector–based computed tomography in myelography after spinal surgery
Authors: Kau Thomas , Rabitsch Egon , Celedin Stefan , Jeschofnig Barbara , Illiasch Herbert , Eicher Wolfgang , Uhl Eberhard , Honl Matthias , Hausegger Klaus Armin
Published: January 2009

Object

The purpose of this study was to assess the value of myelography using flat-panel detector–based computed tomography (fpCT) in 5 patients in whom the image quality of multislice CT (MSCT) or MR imaging was limited by metal artifacts.

Methods

The application of fpCT to myelographic imaging of the lumbar spine and cervicothoracic junction after surgery was feasible. Multiplanar, preferably sagittal, and 3D reconstructions adequately depicted disc space implants and provided high resolution images of osseous structures.

Results

The images obtained with fpCT allowed evaluation of anatomical details such as single nerve roots and proved especially valuable in a patient with impaired MR imaging results caused by metal artifacts from an intraoperative abrasion. In a case of recurrent disc herniation, imaging results of myelographic fpCT and MSCT scanning were in good agreement.

Conclusions

The novel imaging technique the authors describe yielded adequate results in patients with a history of spinal surgery, may be superior to MSCT scanning in depicting osseous structures and metallic implants, and has the potential to provide multilevel spinal images. Myelographic fpCT scanning may be the preferred modality in patients with expected or known metal artifacts on myelographic MSCT scans and/or MR images.
A novel strategy for repairing preganglionic cervical root avulsion in brachial plexus injury by sural nerve grafting
Authors: Wu Jau-Ching , Huang Wen-Cheng , Huang Ming-Chao , Tsai Yun-An , Chen Yu-Chun , Shih Yang-Hsin , Cheng Henrich
Published: January 2009

Object

In this study, the authors evaluated the efficacy of a new surgical strategy for reconnecting the injured brachial plexus with the spinal cord using fibrin glue containing acidic fibroblast growth factor as an adhesive and neurotrophic agent.

Methods

Eighteen patients with preganglionic brachial plexus injuries, each with varying degrees of upper limb dysfunction, underwent cervical laminectomy with or without sural nerve grafting. The treatment of each avulsed root varied according to the severity of the injury. Some patients also underwent a second-stage operation involving supraclavicular brachial plexus exploration for reconnection with the corresponding segment of cervical spinal cord at the trunk level. Muscle strength was graded both pre- and postoperatively with the British Medical Research Council scale, and the results were analyzed with the Friedman and Wilcoxon signed-rank tests.

Results

Muscle strength improvements were observed in 16 of the 18 patients after 24 months of follow-up. Significant improvements in mean muscle strength were observed in patients from all repair method groups at 12 and 24 months postoperatively (p < 0.05). Statistical significance was not reached in the groups with insufficient numbers of cases.

Conclusions

The authors' new surgical strategy yielded clinical improvement in muscle strength after preganglionic brachial plexus injury, such that nerve regeneration may have taken place. Reconnection of the brachial plexus to the cervical spinal cord is possible. Functional motor recovery, observed through increases in Medical Research Council–rated muscle strength in the affected arm, is likewise possible.
Image-based drill templates for cervical pedicle screw placement
Authors: Ryken Timothy C. , Owen Brent D. , Christensen Gary E. , Reinhardt Joseph M.
Published: January 2009

Object

Pedicle screws (PSs) in the cervical spine can provide fixation superior to current fixation methods; however, their implementation is challenging due to the small size of the cervical vertebrae. In this study, the authors explored and evaluated the use of patient-specific, rapid prototype drill templates for PS placement in the cervical spine. The goal of the study was to assess the accuracy of a drill template in the placement of cervical PSs at a single vertebral level.

Methods

Volumetric CT scanning was performed in 4 cadaveric cervical spines. Using computer software, the authors constructed drill templates with a predefined trajectory designed to match the posterior surface of vertebrae C3–7. Twenty physical templates were created from the computer models using a rapid prototyping machine. The drill templates were used to guide pilot-hole drilling, and CT scanning was performed to assess the accuracy of the pilot holes. Pedicle screws (3.5-mm diameter) were placed in the pilot holes. The spines were then dissected to separate the vertebrae, and the trajectory of the screws was visually inspected.

Results

The feasibility of this patient-specific, rapid prototyping technique was demonstrated. Imaging and visual inspection of pilot holes and cervical PSs revealed that the majority of trajectories did not violate the pedicle cortex (19 [95%] of 20). The single cortical violation was judged as noncritical and would probably not have resulted in injury to a patient.

Conclusions

The potential of drill templates to aid in the placement of cervical PSs is promising. The authors' methods appear to provide an accurate technique and trajectory for PS placement in the cervical spine.
Spinal cord vascular shunts: spinal cord vascular malformations and dural arteriovenous fistulas
Authors: da Costa Leodante , Dehdashti Amir R. , terBrugg E Karel G.
Published: January 2009

Object

Spinal cord vascular malformations are rare, fascinating lesions. In this paper, the authors' goal was to demonstrate how these lesions, more specifically spinal cord arteriovenous malformations and dural arteriovenous fistulas, are assessed, classified, and managed at their institution. They also highlight some aspects of classification and management that may be different from the views of others.

Methods

The authors reviewed the 20-year experience at the senior author's institution regarding the management of spinal cord vascular malformations. They discuss the management, surgical and endovascular treatment results, and the classification that resulted from the combined experience of 3 major reference centers.

Results

The accumulated knowledge on embryological and pathophysiological aspects in such a rare disease resulted in a more global, patient-oriented (and not radiologically oriented) approach to spinal cord shunts.

Conclusions

The multiple classifications proposed for spinal cord vascular malformations reflect the continuous advancement of the authors' understanding. They adopt a classification based on new physiological and genetic data that treats these lesions as expressions of more complex disease processes and not simply a morphological target, with direct impact on therapeutic options.
Endovascular management of spinal vascular malformations: history and literature review
Authors: Medel Ricky , Crowley R. Webster , Dumont Aaron S.
Published: January 2009

Spinal vascular malformations represent a complex group of entities whose treatment paradigm continually evolves. Given the ever-increasing role of endovascular therapy, it is the goal of the authors to review the current literature regarding this therapeutic tool and to provide recommendations guiding management. A thorough literature search was conducted using Medline, with subsequent articles being identified through cross-referencing. The analysis revealed that, since its introduction in the 1960s, endovascular therapy has been used to manage the entire spectrum of spinal vascular malformations, during which period it has undergone considerable technological and technical evolution. As such, embolization has proved of growing therapeutic utility, largely resulting from the mounting evidence supporting its safety and efficacy, in addition to the inherent minimally invasive nature. This alternative to surgical intervention will be increasingly used as first-line therapy in spinal vascular malformations.
1T Pixel Using Floating-Body MOSFET for CMOS Image Sensors
Authors: Lu Guo-Neng , Tournier Arnaud , Roy François , Deschamps Benoît
Published: January 2009

We present a single-transistor pixel for CMOS image sensors (CIS). It is a floating-body MOSFET structure, which is used as photo-sensing device and source-follower transistor, and can be controlled to store and evacuate charges. Our investigation into this 1T pixel structure includes modeling to obtain analytical description of conversion gain. Model validation has been done by comparing theoretical predictions and experimental results. On the other hand, the 1T pixel structure has been implemented in different configurations, including rectangular-gate and ring-gate designs, and variations of oxidation parameters for the fabrication process. The pixel characteristics are presented and discussed.