bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acute axis fractures: a review of 229 cases
Authors: Hadley Mark N. , Dickman Curtis A. , Browner Carol M. , Sonntag Volker K. H. 
Published: May 2009

✓ Eighteen percent of acute cervical spine fractures involve the C-2 vertebra. The odontoid Type II fracture is the most common axis fracture and it is also the most difficult to treat. The degree of odontoid dislocation has been identified as the single most important fracture feature that helps separate those patients who have a high likelihood of healing with nonoperative therapy from those who are likely to fail nonoperative therapy and should be offered early surgical stabilization. The difference is statistically significant (p < 0.001, x2 = 30.20).
The present series includes 229 patients with acute axis fractures. Follow-up data were available in 92% of these patients, for a median duration of 4 years 9 months. Treatment guidelines and results are offered for each subtype of axis fracture based on this experience.
Experimental missile wound to the brain
Authors: Carey Michael E. , Sarna Gurcharan S. , Farrell J. Bryan , Happel Leo T. 
Published: May 2009

✓ Among civilians in the United States, 33,000 gunshot wound deaths occur each year; probably half of these involve the head. In combat, head wounds account for approximately half of the immediate mortality when death can be attributed to a single wound. No significant reduction in the neurosurgical mortality associated with these wounds has occurred between World War II and the Vietnam conflict, and very little research into missile wounds of the brain has been undertaken. An experimental model has been developed in the anesthetized cat whereby a ballistic injury to the brain may be painlessly reproduced in order that the pathophysiological effects of brain wounding may be studied and better treatments may be designed to lower the mortality and morbidity rates associated with gunshot wounds.
Prominent among physiological effects observed in this model was respiratory arrest even though the missile did not injure the brain stem directly. The incidence of prolonged respiratory arrest increased with increasing missile energy, but arrest was often reversible provided respiratory support was given. It is possible that humans who receive a brain wound die from missile-induced apnea instead of brain damage per se. The mortality rate in humans with brain wounding might be reduced by prompt respiratory support. Brain wounding was associated with persistently increased intracranial pressure and reduced cerebral perfusion pressure not entirely attributable to intracranial bleeding. The magnitude of these derangements appeared to be missile energy dependent and approached dangerous levels in higher-energy wounds.
All wounded cats exhibited postwounding increases in blood glucose concentrations consistent with a generalized stress reaction. A transient rise in hematocrit also occurred immediately after wounding. Both of these phenomena could prove deleterious to optimal brain function after injury.
A Unified Strategy for Exceptionally High Diastereoselectivity in the Photochemical Ring Closure of Chiral Diarylethenes
Authors: Yokoyama Yasushi , Shiozawa Tatsuya , Tani Yutaka , Ubukata Takashi 
Published: May 2009

AbstractInto my arms: Photochemical cyclization of diarylethenes that have two chiral side arms showed up to 100 % de (see scheme). Introduction of these chiral side arms onto the carbon atoms where ring closure occurs is a general strategy for the highly diastereoselective cyclization of diarylethenes.magnified image
Kinetic Resolution of Aliphatic β‐Amino Acid Amides by β‐Aminopeptidases
Authors: Heck Tobias , Seebach Dieter , Osswald Steffen , ter Wiel Matthijs K. J. , Kohler Hans‐Peter E. , Geueke Birgit 
Published: May 2009

AbstractAccess to enantiopure β‐amino acids: β‐Aminopeptidases are hydrolases that possess the unique ability to cleave N‐terminal β‐amino acids from peptides and amides. Hydrolysis of racemic β‐amino acid amides catalyzed by these enzymes displays enantioselectivity with strong preference for substrates with the L‐configuration, and gives access to various aliphatic β‐amino acids of high enantiopurity.magnified imageThe growing demand for enantiomerically pure β‐amino acids to be used in the pharmaceutical industry and as fine chemicals requires the development of new strategies for their synthesis. The β‐aminopeptidases BapA from Sphingosinicella xenopeptidilytica 3‐2W4, BapA from Sphingosinicella microcystinivorans Y2, and DmpA from Ochrobactrum anthropi LMG7991 are hydrolases that possess the unique ability of cleaving N‐terminal β‐amino acids from peptides and amides. Hydrolysis of racemic β3‐amino acid amides catalyzed by these enzymes displays enantioselectivity with a strong preference for substrates with the L‐configuration and gives access to various aliphatic β3‐amino acids of high enantiopurity. This approach presents a new access to enantiopure β3‐amino acids under mild reaction conditions and complements chemical asymmetric synthesis strategies.
Transcatheter creation of an aortopulmonary shunt in an animal model
Authors: Sabi Titus Mbah , Schmitt Boris , Sigler Matthias , Zanjani Keyhan Sayadpour , Ovroutski Stanislav , Peters Bjoern , Miera Oliver , Nagdyman Nicole , Kuehne Titus , Berger Felix , Ewert Peter 
Published: May 2009

AbstractBackground:The surgical creation of an aortopulmonary shunt is an important tool in the therapy of complex congenital heart defects. We report on a transcatheter approach to establish an aortopulmonary shunt in piglets.Material, Methods and Results:In 10 piglets with a median body weight of 10.5 kg (8–12 kg), a central aortopulmonary shunt was created by radiofrequency perforation from the aorta to the pulmonary trunk, followed by stent implantation. The procedures were performed via the femoral vessels through 5F sheaths under biplane fluoroscopy guidance. A total of six bare metal coronary stents and five polytetrafluoroethylene‐covered coronary stents of 3–4 mm diameter were deployed. Four animals were sacrificed immediately after intervention; six pigs were reevaluated 4–5 weeks later for stent patency and measurement of shunt volume. The procedure was successful in all pigs. Median shunt volume was Qp:Qs = 2.4:1. At re‐evaluation median body weight had increased to 18 kg (15.5–27.5 kg) P < 0.028. Four of six stents were completely obstructed due to tissue ingrowth in the bare metal stents (two cases) and thrombus formation in the covered stents (two cases). A third bare metal stent had a residual lumen, and a third covered stent was fully open without any thrombus formation or tissue ingrowth.Conclusions:Transcatheter creation of an aortopulmonary shunt by radiofrequency perforation and stent implantation is feasible. The use of appropriate covered stents and an effective anticoagulatory regimen seem to be crucial to keep the shunts open. © 2009 Wiley‐Liss, Inc.
Emesis predicts bacteremia in immunocompromised children with central venous catheters and fever
Authors: Richardson Matthew W. , Grewal Satkiran S. , Visintainer Paul F. 
Published: May 2009

AbstractBACKGROUND:The objective of this study was to determine whether vomiting at presentation of a febrile illness in immunocompromised children with central venous catheters (CVCs) predicts bacteremia.METHODS:A chart review was conducted of children who were admitted to the hospital with a diagnosis of cancer or aplastic anemia, fever, and a CVC. Data were collected on the presence or absence of vomiting, catheter type, presence or absence of severe neutropenia, C‐reactive protein (Crp) value, and culture results.RESULTS:There were 143 admissions for fever among 48 children. Among 35 admissions with emesis, 19 included bacteremia; whereas, among 107 admissions without emesis, 19 included bacteremia (P < .001). There was a 5‐fold greater risk of bacteremia in children with children without vomiting (odds ratio, 5.50; 95% confidence interval, 2.20‐13.67). Gram‐negative organisms were more likely to be associated with vomiting than Gram‐positive organisms (P = .008). Children with severe neutropenia did not have a significantly higher rate of bacteremia than children who had neutrophil counts >500 cells/mm3. Other factors that were associated with higher rates of bacteremia were underlying diagnosis and catheter type.CONCLUSIONS:Immunocompromised children with a CVC and a fever who presented with vomiting were more likely to have bacteremia than similar children who presented without vomiting. Gram‐negative organisms were more likely to be associated with emesis than Gram‐positive organisms. The absence of severe neutropenia was not associated with a decreased likelihood of bacteremia. These findings may be useful in identifying children who are at high risk for bacteremia and in determining initial, empiric therapy. Cancer 2009. © 2009 American Cancer Society.
Sequential onset of presynaptic molecules during olfactory sensory neuron maturation
Authors: Marcucci Florencia , Zou Dong‐Jing , Firestein Stuart 
Published: May 2009

AbstractDifferentiated olfactory sensory neurons express specific presynaptic proteins, including enzymes involved in neurotransmitter transport and proteins involved in the trafficking and release of synaptic vesicles. Studying the regulation of these presynaptic proteins will help to elucidate the presynaptic differentiation process that ultimately leads to synapse formation. It has been postulated that the formation of a synapse between the axons of the sensory neurons and the dendrites of second order neurons in the olfactory bulb is a critical step in the processes of sensory neuron maturation. One approach to study the relationship between synaptogenesis and sensory neuron maturation is to examine the expression patterns of synaptic molecules through the olfactory neuron lineage. To this end we designed specific in situ hybridization probes to target messengers for proteins involved in presynaptic vesicle release. Our findings show that, as they mature, mouse olfactory neurons sequentially express specific presynaptic genes. Furthermore, the different patterns of expression of these presynaptic genes suggest the existence of discrete steps in presynaptic development: genes encoding proteins involved in scaffolding show an early onset of expression, whereas expression of genes encoding proteins involved in the regulation of vesicle release starts later. In particular, the signature molecule for glutamatergic neurons vesicle glutamate transporter 2 shows the latest onset of expression. In addition, contact with the targets in the olfactory bulb is not controlling presynaptic protein gene expression, suggesting that olfactory sensory neurons follow an intrinsic program of development. J. Comp. Neurol. 516:187–198, 2009. © 2009 Wiley‐Liss, Inc.
Sexual dimorphism and hormone responsiveness in the spinal cord of the socially monogamous prairie vole (Microtus ochrogaster)
Authors: Holmes Melissa M. , Musa Mutaz , Lonstein Joseph S. , Monks D. Ashley 
Published: May 2009

AbstractPrairie voles (Microtus ochrogaster) are exceptional among rodents in that many aspects of their brain and behavior are not masculinized by exogenous aromatizable androgens. However, the sexually differentiated endpoints studied to date rely on estrogenic mechanisms in other mammals. We examined whether sexual differentiation of an androgen receptor‐dependent sex difference would be similarly distinct in prairie voles. Male mammals have more and larger motoneurons projecting to perineal muscles than do females. This sex difference normally arises from males' perinatal androgen exposure and can be eliminated by treating developing females with androgens. Gross dissection revealed bulbospongiosus muscles in adult male, but not female, prairie voles. Retrograde tracing from males' bulbocavernosus muscles and the external anal sphincter from both sexes revealed sexually dimorphic populations of labeled motoneurons in the ventral horn of the lumbar spinal cord. Similar to other rodents, males had twice as many motoneurons as females, although no sex difference in motoneuron size was detected. Unexpectedly, prenatal or early postnatal exposure to testosterone propionate had no effect on adult females' motoneuron number or size. In adulthood, gonadectomy alone or followed by chronic testosterone treatment also had no effect on females' motoneuron size or number, although castration reduced motoneuron size in males. Comparing gonadally intact weanlings confirmed that the sex difference in motoneuron number exists before adulthood. As with some other sexually dimorphic traits, and perhaps related to their unique social organization, sexual differentiation of the prairie vole spinal cord differs from that found in most other laboratory rodents. J. Comp. Neurol. 516:117–124, 2009. © 2009 Wiley‐Liss, Inc.
Vagal gustatory reflex circuits for intraoral food sorting behavior in the goldfish: Cellular organization and neurotransmitters
Authors: Ikenaga Takanori , Ogura Tatsuya , Finger Thomas E. 
Published: May 2009

AbstractThe sense of taste is crucial in an animal's determination as to what is edible and what is not. This gustatory function is especially important in goldfish, who utilize a sophisticated oropharyngeal sorting mechanism to separate food from substrate material. The computational aspects of this detection are carried out by the medullary vagal lobe, which is a large, laminated structure combining elements of both the gustatory nucleus of the solitary tract and the nucleus ambiguus. The sensory layers of the vagal lobe are coupled to the motor layers via a simple reflex arc. Details of this reflex circuit were investigated with histology and calcium imaging. Biocytin injections into the motor layer labeled vagal reflex interneurons that have radially directed dendrites ramifying within the layers of primary afferent terminals. Axons of reflex interneurons extend radially inward to terminate onto both vagal motoneurons and small, GABAergic interneurons in the motor layer. Functional imaging shows increases in intracellular Ca++ of vagal motoneurons following electrical stimulation in the sensory layer. These responses were suppressed under Ca++‐free conditions and by interruption of the axons bridging between the sensory and motor layers. Pharmacological experiments showed that glutamate acting via (±)‐α‐amino‐3‐hydroxy‐ 5‐ethylisoxazole‐4‐propioinc acid (AMPA)/kainate and N‐methyl‐D‐aspartic acid (NMDA) receptors mediate neurotransmission between reflex interneurons and vagal motoneurons. Thus, the vagal gustatory portion of the viscerosensory complex is linked to branchiomotor neurons of the pharynx via a glutamatergic interneuronal system. J. Comp. Neurol. 516:213–225, 2009. © 2009 Wiley‐Liss, Inc.
Immunotoxin‐induced ablation of melanopsin retinal ganglion cells in a non‐murine mammalian model
Authors: Ingham Elizabeth S. , Günhan Emine , Fuller Patrick M. , Fuller Charles A. 
Published: May 2009

AbstractIn mammals, non‐image‐forming visual functions, including circadian photoentrainment and the pupillary light reflex, are thought to be mediated by the combination of rods, cones, and the melanopsin‐expressing intrinsically photosensitive retinal ganglion cells (ipRGCs). Although several genetic models have been developed to clarify the individual roles of the rod, cone, and ipRGC systems in mediating non‐image visual function, assessing the in vivo role(s) of the ipRGCs has been complicated by the possibility of ontogenetic issues in these genetically modified animal models. In the present study, we describe the development and validation of an immunotoxin that specifically targets the ipRGC population in the mature mammalian retina. This ipRGC immunotoxin, consisting of saporin conjugated to a melanopsin polyclonal antibody, was evaluated with respect to its effectiveness and specificity in depleting the ipRGC population in the fully developed rat retina. The results showed that the ipRGC toxin rapidly and permanently depleted ∼70% of the ipRGC population, without inducing appreciable changes in the cell number or morphology of any of the non‐melanopsin‐containing retinal cell populations investigated. These findings suggest that the newly developed ipRGC immunotoxin provides a potent method for achieving relatively rapid, permanent, and selective depletion of the ipRGC population in a non‐murine model system. The development of this ipRGC‐ablation method is the next step in elucidating the role of ipRGCs in mediating non‐visual and circadian light‐resetting responses in a wide range of non‐murine mammalian models. J. Comp. Neurol. 516:125–140, 2009. © 2009 Wiley‐Liss, Inc.
Thymidine analog methods for studies of adult neurogenesis are not equally sensitive
Authors: Leuner Benedetta , Glasper Erica R. , Gould Elizabeth 
Published: May 2009

AbstractAdult neurogenesis is often studied by labeling new cells with the thymidine analog bromodeoxyuridine (BrdU) and using immunohistochemical methods for their visualization. Using this approach, considerable variability has been reported in the number of new cells produced in the dentate gyrus of adult rodents. We examined whether immunohistochemical methods, including BrdU antibodies from different vendors (Vector, BD, Roche, Dako, Novocastra, and Accurate) and DNA denaturation pretreatments alter the quantitative and qualitative patterns of BrdU labeling. We also compared the sensitivity and specificity of BrdU with two other thymidine analogs, iododeoxyuridine (IdU) and chlorodeoxyuridine (CldU). We found that the number of BrdU‐labeled cells in the dentate gyrus of adult rats was dependent on the BrdU antibody used but was unrelated to differences in antibody penetration. Even at a higher concentration, some antibodies (Vector and Novocastra) stained fewer cells. A sensitive BrdU antibody (BD) was specific for dividing cells; all BrdU‐labeled cells stained for Ki67, an endogenous marker of cell proliferation. We also observed that DNA denaturation pretreatments affected the number of BrdU‐labeled cells and staining intensity for a marker of neuronal differentiation, NeuN. Finally, we found that IdU and CldU, when used at molarities comparable to those that label the maximal number of cells with BrdU, are less sensitive. These data suggest that antibody and thymidine analog selection, as well as the staining procedure employed, can affect the number of newly generated neurons detected in the adult brain, thus providing a potential explanation for some of the variability in the adult neurogenesis literature. J. Comp. Neurol. 517:123–133, 2009. © 2009 Wiley‐Liss, Inc.
Exciton Diffusion in Polyfluorene Copolymer Thin Films: Kinetics, Energy Disorder and Thermally Assisted Hopping
Authors: Dias Fernando B. , Kamtekar Kiran T. , Cazati Thiago , Williams Geoff , Bryce Martin R. , Monkman Andrew P. 
Published: May 2009

AbstractA series of {(9,9‐dioctylfluorene)0.7−x‐(dibenzothiophene‐S,S‐dioxide)0.3‐[4,7‐bis(2‐thienyl)‐2,1,3‐benzothiadiazole]x} (PFS30‐TBTx), where x represents the minor percentage of the red emitter 4,7‐bis(2‐thienyl)‐2,1,3‐benzothiadiazole (TBT) randomly incorporated into the copolymer backbone, is investigated in order to follow the energy transfer from PFS30 to TBT moieties. The emission of the donor poly[(9,9‐dioctylfluorene)0.7‐(dibenzothiophene‐S,S‐dioxide)0.3 identified by PFS30 and peaking at 450 nm, is clearly quenched by the presence of the red TBT chromophore emitting at 612 nm, with an isoemissive point observed when the spectra are collected as a function of temperature. A plot of the ratio between the TBT and PFS30 emissions as a function of the reciprocal of temperature gives a clear linear trend between 290 and 200 K, with an activation energy of 20 meV and showing a turn over to a non‐activated regime below 200 K. Picosecond time‐resolved fluorescence decays collected at the PFS30 and TBT emission wavelengths, show a decay of the PFS30 emission and a fast build‐in, followed by a decay, of the TBT emission, confirming that the population of the TBT excited state occurs during the PFS30 lifetime(∼600 ps). The population of the TBT excited state occurs on a time regime around 150 ps at 290 K, showing an energy barrier of 20 meV that turns over to a non‐activated regime below 200 K in clear agreement with the steady‐state data. The origin of the activation barrier is attributed to the presence of physical and energetic disorder, affected by fast thermal fluctuations that dynamically change the energy landscape and control the exciton migration through the polymer density of states.
Identification of genes expressed preferentially in the developing peripheral margin of the optic cup
Authors: Trimarchi Jeffrey M. , Cho Seo‐Hee , Cepko Constance L. 
Published: May 2009

AbstractSpecification of the peripheral optic cup by Wnt signaling is critical for formation of the ciliary body/iris. Identification of marker genes for this region during development provides a starting point for functional analyses. During transcriptional profiling of single cells from the developing eye, two cells were identified that expressed genes not found in most other single cell profiles. In situ hybridizations demonstrated that many of these genes were expressed in the peripheral optic cup in both early mouse and chicken development, and in the ciliary body/iris at subsequent developmental stages. These analyses indicate that the two cells probably originated from the developing ciliary body/iris. Changes in expression of these genes were assayed in embryonic chicken retinas when canonical Wnt signaling was ectopically activated by CA‐β‐catenin. Twelve ciliary body/iris genes were identified as upregulated following induction, suggesting they are excellent candidates for downstream effectors of Wnt signaling in the optic cup. Developmental Dynamics 238:2327–2339, 2009. © 2009 Wiley‐Liss, Inc.
Cytoplasmic localization of oocyte‐specific variant of porcine DNA methyltransferase‐1 during early development
Authors: Jeong Young Sun , Oh Keon Bong , Park Jung Sun , Kim Ji‐Su , Kang Yong‐Kook 
Published: May 2009

AbstractDNA methyltransferase‐1 (Dnmt1) is involved in the maintenance of genomic methylation patterns. Rather than full‐length Dnmt1, mouse oocytes have a truncated variant called Dnmt1o. Immunofluorescence data showed that Dnmt1o localized to the cytoplasm, but this has not been confirmed using more direct methods. The cytoplasmic localization of Dnmt1o has been assigned to the main cause of global DNA demethylation in early mouse embryos. We studied localization of Dnmt1o in mouse and pig embryos. We identified pig Dnmt1o protein and its transcript with unique 5′‐end sequence. Physically separating mouse and pig 2‐cell embryos into their nuclear and cytoplasmic components demonstrated that Dnmt1o of both species localized to the cytoplasm. Cloned pig embryos had Dnmt1o as the main form, with no indication of somatic Dnmt1. These findings indicate that Dnmt1o is cytoplasmic during early development; its presence in both pig and mouse embryos further suggests that Dnmt1o is conserved in mammals. Developmental Dynamics 238:1666–1673, 2009. © 2009 Wiley‐Liss, Inc.