bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatially Selective, Testosterone-Independent Remodeling of Dendrites in Gonadotropin-Releasing Hormone (GnRH) Neurons Prepubertally in Male Rats
Authors: Ybarra Natividad , Hemond Peter J. , O'Boyle Michael P. , Suter Kelly J.
Published: February 2011

Adult GnRH neurons exhibit a stereotypic morphology with a small soma, single axon, and single dendrite arising from the soma with little branching. The adult morphology of GnRH neurons in mice reflects an anatomical consolidation of dendrites over postnatal development. We examined this issue in rat GnRH neurons with biocytin filling in live hypothalamic slices from infant males, as adult littermates and in gonad-intact males, castrated males, and in males with one of three levels of testosterone (T) treatment. Somatic area and total dendritic length were significantly greater in infant males than in adults. Moreover, total numbers of dendrite branches were greater in infant males as compared with adults. The number of higher order branches and the lengths of higher order branches were also greater in infant males than in adults. Most interestingly, in adults a single dendrite arose from the somata, consistently at 180° from the axon. In contrast, prepubertal animals had an average of 2.2 ± 0.2 primary dendrites arising from somata (range, one to seven primary dendrites). Angles relative to the axon at which dendrites in prepubertal males emanated from GnRH somata were highly variable. Castration at 25 d of age and castration at 25 d of age with one of three levels of T treatment did not influence morphological parameters when GnRH neurons were examined between 40 d and 48 d of age. Thus, a spatially selective remodeling of primary dendrites and consolidation of distal GnRH dendritic arbors occurs during postnatal development and is largely independent of T.
Expression of Insulinoma-Associated 2 (INSM2) in Pancreatic Islet Cells Is Regulated by the Transcription Factors Ngn3 and NeuroD1
Authors: Cai Tao , Chen Xiang , Wang Rennian , Xu Huan , You Yuhui , Zhang Tao , Lan Michael S. , Notkins Abner L.
Published: February 2011

The insulinoma-associated 2 (Insm2) gene is a member of the Snail/Gfi1/Insm1 transcriptional repressor superfamily. However, little is known about how the expression of human INSM2 or mouse Insm2 in neuroendocrine tissues is regulated. Here we report the expression of INSM2/Insm2 in human fetal pancreas and mouse embryos, as well as adult pancreatic islets, and its regulation by two major islet transcription factors. Mutagenesis and chromatin immunoprecipitation analysis demonstrated that the proximal E-boxes of the mouse Insm2 promoter are direct targets of neurogenin 3 and neurogenic differentiation 1 (NeuroD1). Furthermore, we found that endogenous Insm2 expression was activated in Ngn3/NeuroD1-transduced pancreatic epithelial duct cells. Our results suggest that Insm2 plays an important role in the differentiation cascade of Ngn3/NeuroD1 signaling in pancreatic islets.
Teriparatide [rhPTH (1-34)], But Not Strontium Ranelate, Demonstrated Bone Anabolic Efficacy in Mature, Osteopenic, Ovariectomized Rats
Authors: Ma Yanfei L. , Zeng Qing Q. , Porras Leah L. , Harvey Anita , Moore Terry L. , Shelbourn Timothy L. , Dalsky Gail P. , Wronski Thomas J. , Aguirre J. Ignacio , Bryant Henry U. , Sato Masahiko
Published: February 2011

We compared teriparatide (TPTD) and strontium ranelate (SR) efficacy on bone formation activity in a mature rat model of estrogen-deficiency bone loss. Rats were ovariectomized (OVX) at age 6 months and permitted to lose bone for 2 months to establish osteopenia before initiation of treatment with TPTD (5 or 15 μg/kg · d sc) or SR (150 or 450 mg/kg · d oral gavage). After 3 wk, RT-PCR analyses of bone formation genes in the distal femur metaphysis showed significant elevation of collagen 1α2, osteocalcin, bone sialoprotein, alkaline phosphatase, and Runx2 gene expression at both TPTD doses, relative to OVX controls. SR had no significant effect on expression of these genes. TPTD treatment for 12 wk dose dependently increased lumbar vertebral (LV) and femoral midshaft bone mineral content (BMC) and bone mineral density over pretreatment and age-matched OVX controls. SR 150 increased BMC, and SR 450 increased BMC and bone mineral density of femoral midshaft and LV over OVX controls. There were significant dose-dependent TPTD increases of LV and femoral neck strength, and TPTD 15 also increased midshaft strength compared with pretreatment and age-matched OVX controls. SR did not enhance bone strength relative to pretreatment or age-matched OVX controls. Histomorphometry of the proximal tibial metaphysis showed dose-dependent effects of TPTD on trabecular area, number, width, and osteoblast surface, bone mineralizing surface, and bone formation rate relative to pretreatment and age-matched OVX controls, whereas SR had no effect on these parameters. These findings confirmed the bone anabolic efficacy of teriparatide, but not SR in mature, osteopenic, OVX rats.
Differential Acute and Chronic Effects of Leptin on Hypothalamic Astrocyte Morphology and Synaptic Protein Levels
Authors: García-Cáceres Cristina , Fuente-Martín Esther , Burgos-Ramos Emma , Granado Miriam , Frago Laura M. , Barrios Vicente , Horvath Tamas , Argente Jesús , Chowen Julie A.
Published: February 2011

Astrocytes participate in neuroendocrine functions partially through modulation of synaptic input density in the hypothalamus. Indeed, glial ensheathing of neurons is modified by specific hormones, thus determining the availability of neuronal membrane space for synaptic inputs, with the loss of this plasticity possibly being involved in pathological processes. Leptin modulates synaptic inputs in the hypothalamus, but whether astrocytes participate in this action is unknown. Here we report that astrocyte structural proteins, such as glial fibrillary acidic protein (GFAP) and vimentin, are induced and astrocyte morphology modified by chronic leptin administration (intracerebroventricular, 2 wk), with these changes being inversely related to modifications in synaptic protein densities. Similar changes in glial structural proteins were observed in adult male rats that had increased body weight and circulating leptin levels due to neonatal overnutrition (overnutrition: four pups/litter vs. control: 12 pups/litter). However, acute leptin treatment reduced hypothalamic GFAP levels and induced synaptic protein levels 1 h after administration, with no effect on vimentin. In primary hypothalamic astrocyte cultures leptin also reduced GFAP levels at 1 h, with an induction at 24 h, indicating a possible direct effect of leptin. Hence, one mechanism by which leptin may affect metabolism is by modifying hypothalamic astrocyte morphology, which in turn could alter synaptic inputs to hypothalamic neurons. Furthermore, the responses to acute and chronic leptin exposure are inverse, raising the possibility that increased glial activation in response to chronic leptin exposure could be involved in central leptin resistance.
17β-Estradiol Increases Astrocytic Vascular Endothelial Growth Factor (VEGF) in Adult Female Rat Hippocampus
Authors: Barouk Sharon , Hintz Tana , Li Ping , Duffy Aine M. , MacLusky Neil J. , Scharfman Helen E.
Published: February 2011

Vascular endothelial growth factor (VEGF) is critical to angiogenesis and vascular permeability. It is also important in the endocrine system, in which VEGF mediates the vascular effects of estrogens in target tissues such as the uterus, a response attributed to an estrogen response element on the VEGF gene. Here we asked whether 17β-estradiol increases VEGF levels in the brain. We focused on the hippocampus, in which 17β-estradiol and VEGF both have important actions, and used immunocytochemistry to evaluate VEGF protein. VEGF immunoreactivity was compared in adult female rats sampled during the estrous cycle when serum levels of 17β-estradiol peak (proestrous morning) as well as when they are low (metestrous morning). In addition, adult rats were ovariectomized and compared after treatment with 17β-estradiol or vehicle. The results demonstrated that VEGF immunoreactivity was increased when serum levels of 17β-estradiol were elevated. Confocal microscopy showed that VEGF immunofluorescence was predominantly nonneuronal, often associated with astrocytes. Glial VEGF labeling was primarily punctate rather than diffuse and labile because glial VEGF immunoreactivity was greatly reduced if tissue sections were left in an aqueous medium overnight. We conclude that VEGF protein in normal female hippocampus is primarily nonneuronal rather than neuronal and suggest that glial VEGF immunoreactivity has been underestimated by past studies with other methods because there is a labile extracellular pool. We suggest that estrogens may exert actions on female hippocampal structure and function by increasing hippocampal VEGF.
DNA Methylation of Intronic Enhancers Directs Tissue-Specific Expression of Steroidogenic Factor 1/Adrenal 4 Binding Protein (SF-1/Ad4BP)
Authors: Hoivik Erling A. , Bjanesoy Trine E. , Mai Oliver , Okamoto Shiki , Minokoshi Yasuhiko , Shima Yuichi , Morohashi Ken-ichirou , Boehm Ulrich , Bakke Marit
Published: February 2011

The nuclear receptor steroidogenic factor 1/adrenal 4 binding protein (SF-1/Ad4BP) is an essential regulator of endocrine development and function, and the expression of the corresponding gene (sf-1/ad4bp) is precisely regulated in a time- and tissue-dependent manner. We previously demonstrated that the basal promoter of sf-1/ad4bp is controlled by DNA methylation and that its methylation status reflects the expression pattern of SF-1/Ad4BP. Recently, three intronic enhancers were identified in the sf-1/ad4bp gene that target SF-1/Ad4BP expression to the fetal adrenal (FAdE; fetal adrenal-specific enhancer), to pituitary gonadotropes (PGE; pituitary gonadotrope-specific enhancer), and to the ventromedial hypothalamic nucleus (VMHE; ventromedial hypothalamic nucleus-specific enhancer). Here, we demonstrate that the activity of these enhancers is correlated with their DNA methylation status. We show that they are hypomethylated in tissues where they are active and generally hypermethylated in tissues where they are not active. Furthermore, we demonstrate in transient transfection experiments that forced DNA methylation represses reporter gene activity driven by these enhancers. These data directly demonstrate a functional significance for the enhancers' methylation status. Intriguingly, further analyses of the basal promoter in gonadotropes revealed that it is methylated in these cells, in contrast to other SF-1/Ad4BP-expressing tissues. Consistent with this, sf-1/ad4bp is transcribed from an alternative promoter in gonadotropes. Taken together, our experiments show that the tissue-specific expression of SF-1/Ad4BP is epigenetically regulated and identify tissue-specific differentially methylated regions within the sf-1/ad4bp locus that are essential for its transcriptional control.
Ocelli contribute to the encoding of celestial compass information in the Australian desert antMelophorus bagoti
Authors: Schwarz Sebastian , Albert Laurence , Wystrach Antoine , Cheng Ken
Published: February 2011

Many animal species, including some social hymenoptera, use the visual system for navigation. Although the insect compound eyes have been well studied, less is known about the second visual system in some insects, the ocelli. Here we demonstrate navigational functions of the ocelli in the visually guided Australian desert ant Melophorus bagoti. These ants are known to rely on both visual landmark learning and path integration. We conducted experiments to reveal the role of ocelli in the perception and use of celestial compass information and landmark guidance. Ants with directional information from their path integration system were tested with covered compound eyes and open ocelli on an unfamiliar test field where only celestial compass cues were available for homing. These full-vector ants, using only their ocelli for visual information, oriented significantly towards the fictive nest on the test field, indicating the use of celestial compass information that is presumably based on polarised skylight, the sun's position or the colour gradient of the sky. Ants without any directional information from their path-integration system (zero-vector) were tested, also with covered compound eyes and open ocelli, on a familiar training field where they have to use the surrounding panorama to home. These ants failed to orient significantly in the homeward direction. Together, our results demonstrated that M. bagoti could perceive and process celestial compass information for directional orientation with their ocelli. In contrast, the ocelli do not seem to contribute to terrestrial landmark-based navigation in M. bagoti.
Energy budget during lactation in striped hamsters at different ambient temperatures
Authors: Zhao Zhi-Jun
Published: February 2011

The combination of two stressors, lactation and cold, is suggested to be an excellent model for testing the factors limiting sustained energy intake (SusEI). Limits to SusEI during peak lactation may be imposed peripherally by the capacity of mammary glands to produce milk or may be driven by the ability of animals to dissipate body heat. To distinguish between the two mechanisms, body mass change, food intake, reproductive output (using litter size and mass) and serum prolactin (PRL) levels were measured in striped hamsters lactating at 23, 30 and 5°C. Resting metabolic rate (RMR) during late lactation was also measured. Female hamsters lactating at 5°C showed significantly lower change in body mass, but had higher food intake and RMR than females at 23 and 30°C. Asymptotic food intake averaged 14.6±0.4, 14.5±0.7 and 16.2±0.5 g d–1 for females at 23, 30 and 5°C, respectively. The females at 5°C had 11.4% higher asymptotic food intake than females at 23 and 30°C (F2,51=3.3, P<0.05, Tukey's HSD, P<0.05). No significant differences in litter size and PRL levels were observed between the three groups; however, litter mass at 5°C was lower by 19.7 and 19.8% than litter mass at 23 and 30°C on day 19 of lactation (F2,51=3.5, P<0.05, Tukey's HSD, P<0.05). Differences in the above parameters between 23 and 30°C were not significant. Litter mass was positively correlated with asymptotic food intake (23°C, r=0.60, P<0.05; 30°C, r=0.94, P<0.01; 5°C, r=0.77, P<0.01). These data suggested that females lactating at cold temperatures increased food intake to compensate for additional energy demands for thermogenesis, but they might not be capable of exporting more energy as milk to the pups, indicating a possible consistency with the peripheral hypothesis. However, the present results do not considerably distinguish the peripheral limitation hypothesis from the heat dissipation limits hypothesis.
Geometric analysis of macronutrient selection in the adult domestic cat, Felis catus
Authors: Hewson-Hughes Adrian K. , Hewson-Hughes Victoria L. , Miller Andrew T. , Hall Simon R. , Simpson Stephen J. , Raubenheimer David
Published: February 2011

We report feeding studies on adult domestic cats designed to disentangle the complex interactions among dietary protein, fat and carbohydrate in the control of intake. Using geometric techniques that combine mixture triangles and intake plots from the geometric framework, we: (1) demonstrate that cats balance their macronutrient intake, (2) estimate the composition of the target balance and (3) reveal the priorities given to different macronutrients under dietary conditions where the target is unachievable. Our analysis indicates that cats have a ceiling for carbohydrate intake, which limits ingestion and constrains them to deficits in protein and fat intake (relative to their target) on high-carbohydrate foods. Finally, we reanalyse data from a previous experiment that claimed that kittens failed to regulate protein intake, and show that, in fact, they did. These results not only add to the growing appreciation that carnivores, like herbivores and omnivores, regulate macronutrient intake, they also have important implications for designing feeding regimens for companion animals.
Comparison of volatile blends and gene sequences of two isolates of Metarhizium anisopliae of different virulence and repellency toward the termite Macrotermes michaelseni
Authors: Mburu David M. , Ndung'u Mary W. , Maniania Nguya K. , Hassanali Ahmed
Published: February 2011

Previously, we reported an interesting relationship between virulence and repellency of different isolates of the fungus Metarhizium anisopliae towards the termite Macrotermes michaelseni: the higher the virulence of a given isolate, the greater its repellency. In the present study, we compared the volatile profiles of two isolates, one that was more virulent (and repellent) and one that was less virulent (and repellent) to the termite. The prominent components of the two blends were characterized by gas chromatography-mass spectrometry and authenticated by gas chromatography coinjections with synthentic standards. There were both qualitative and quantitative differences between the two blends. The repellencies of synthetic blends of 10 prominent constituents of the volatiles of the two isolates were compared and that of the more virulent isolate was found to be significantly more repellent. Subtractive bioassays were carried out with one of the constituents of each of the two 10-component blends missing at a time to determine its relative contribution to the overall repellency. The results indicated that the repellency of the volatiles of each isolate was primarily due to synergistic effects of a smaller number of constituents. Intraspecific differences between the two isolates were also reflected in their nucleotide sequences.
Expression of multidrug resistance proteins is localized principally to the Malpighian tubules in larvae of the cabbage looper moth, Trichoplusia ni
Authors: Labbé Roselyne , Caveney Stanley , Donly Cam
Published: February 2011

The multidrug resistance proteins (MRPs) serve a number of important roles in development, physiological homeostasis and metabolic resistance. In insects, they may also contribute to resistance against xenobiotics including insecticides and plant secondary metabolites. To investigate their contribution to xenobiotic resistance, we have examined the tissue distribution of gene and protein expression of the multidrug resistance proteins TrnMRP1 and TrnMRP4 of the lepidopteran insect, Trichoplusia ni. Using quantitative PCR and immunohistochemistry, we have identified high expression levels of both transporters in the Malpighian tubules relative to levels in other major tissues of the body, where they probably contribute to excretion of metabolic wastes or ingested xenobiotics. We have specifically located TrnMRP protein expression in a subpopulation of Malpighian tubule secondary cells. Expression of TrnMRP1 was also detected both at a high level in specific cortical neurons of larval ganglia and at a lower level throughout the cortex, where it may act in signaling or protective functions, respectively. In contrast, expression of TrnMRP4 was low to absent in larval ganglia, with the exception of single cells in the central connective. We discuss the potential implications of this TrnMRP activity on insect development and metabolic resistance.
Live CT imaging of sound reception anatomy and hearing measurements in the pygmy killer whale, Feresa attenuata
Authors: Montie Eric W. , Manire Charlie A. , Mann David A.
Published: February 2011

In June 2008, two pygmy killer whales (Feresa attenuata) were stranded alive near Boca Grande, FL, USA, and were taken into rehabilitation. We used this opportunity to learn about the peripheral anatomy of the auditory system and hearing sensitivity of these rare toothed whales. Three-dimensional (3-D) reconstructions of head structures from X-ray computed tomography (CT) images revealed mandibles that were hollow, lacked a bony lamina medial to the pan bone and contained mandibular fat bodies that extended caudally and abutted the tympanoperiotic complex. Using auditory evoked potential (AEP) procedures, the modulation rate transfer function was determined. Maximum evoked potential responses occurred at modulation frequencies of 500 and 1000 Hz. The AEP-derived audiograms were U-shaped. The lowest hearing thresholds occurred between 20 and 60 kHz, with the best hearing sensitivity at 40 kHz. The auditory brainstem response (ABR) was composed of seven waves and resembled the ABR of the bottlenose and common dolphins. By changing electrode locations, creating 3-D reconstructions of the brain from CT images and measuring the amplitude of the ABR waves, we provided evidence that the neuroanatomical sources of ABR waves I, IV and VI were the auditory nerve, inferior colliculus and the medial geniculate body, respectively. The combination of AEP testing and CT imaging provided a new synthesis of methods for studying the auditory system of cetaceans.
Regulation of heart rate and rumen temperature in red deer: effects of season and food intake
Authors: Turbill Christopher , Ruf Thomas , Mang Thomas , Arnold Walter
Published: February 2011

Red deer, Cervus elaphus, like other temperate-zone animals, show a large seasonal fluctuation in energy intake and expenditure. Many seasonal phenotypic adjustments are coordinated by endogenous signals entrained to the photoperiod. The cues determining variation in the resting metabolism of ungulates remain equivocal, however, largely because of the confounding effects of food intake and thus the heat increment of feeding. To distinguish endogenous seasonal and environmental effects on metabolism, we subjected 15 female red deer to two feeding treatments, 80% food restriction and low/high protein content, over two winter seasons in a cross-over design experiment. We used rumen-located transmitters to measure heart rate and rumen temperature, which provided indices of metabolism and core body temperature, respectively. Our mixed model (R2=0.85) indicated a residual seasonal effect on mean daily heart rate that was unexplained by the pellet food treatments, activity, body mass or air temperature. In addition to an apparently endogenous down-regulation of heart rate in winter, the deer further reduced heart rate over about 8 days in response to food restriction. We found a strong correlation between rumen temperature and seasonal or periodic variation in heart rate. An effect of lowered rumen (and hence core body) temperature was enhanced during winter, perhaps owing to peripheral cooling, which is known to accompany bouts of hypometabolism. Our experimental results therefore support the hypothesis that a reduction in body temperature is a physiological mechanism employed even by large mammals, like red deer, to reduce their energy expenditure during periods of negative energy balance.
Neurogenomic signatures of spatiotemporal memories in time-trained forager honey bees
Authors: Naeger Nicholas L. , Van Nest Byron N. , Johnson Jennifer N. , Boyd Sam D. , Southey Bruce R. , Rodriguez-Zas Sandra L. , Moore Darrell , Robinson Gene E.
Published: February 2011

Honey bees can form distinct spatiotemporal memories that allow them to return repeatedly to different food sources at different times of day. Although it is becoming increasingly clear that different behavioral states are associated with different profiles of brain gene expression, it is not known whether this relationship extends to states that are as dynamic and specific as those associated with foraging-related spatiotemporal memories. We tested this hypothesis by training different groups of foragers from the same colony to collect sucrose solution from one of two artificial feeders; each feeder was in a different location and had sucrose available at a different time, either in the morning or afternoon. Bees from both training groups were collected at both the morning and afternoon training times to result in one set of bees that was undergoing stereotypical food anticipatory behavior and another that was inactive for each time of day. Between the two groups with the different spatiotemporal memories, microarray analysis revealed that 1329 genes were differentially expressed in the brains of honey bees. Many of these genes also varied with time of day, time of training or state of food anticipation. Some of these genes are known to be involved in a variety of biological processes, including metabolism and behavior. These results indicate that distinct spatiotemporal foraging memories in honey bees are associated with distinct neurogenomic signatures, and the decomposition of these signatures into sets of genes that are also influenced by time or activity state hints at the modular composition of this complex neurogenomic phenotype.
Use of Gabapentin for the Management of Natural or Surgical Menopausal Hot Flashes
Authors: Hayes Laura P , Carroll Dana G , Kelley Kristi W
Published: February 2011

Objective:

To review the literature examining the use of gabapentin for treatment of hot flashes during natural or surgically Induced menopause.

Data Sources:

A literature search was conducted via PubMed, MEDLINE, and International Pharmaceutical Abstracts (1948-November 2010) using the search terms gabapentin, hot flashes, and menopause. Literature was limited to English-language, human studies. Additional material was identified by reviewing reference citations of the articles retrieved.

Study Selection and Data Extraction:

Studies with data describing gabapentin for hot flash management during natural or surgically induced menopause were included. Any studies including women with a history of breast cancer were excluded. Four studies met the inclusion criteria.

Data Synthesis:

Gabapentin significantly decreased hot flash frequency and hot flash composite scores by 45-71% from baseline in the 4 trials included in this review. In 2 of the trials, gabapentin was comparable to hormone replacement therapy (71 % vs 72%, respectively, p = 0.63) in decreasing hot flash composite scores at the end of 12 weeks and in decreasing hot flash frequency at the end of 8 weeks (58.9% vs 70.1 %, p > 0.05). In all trials, the most common adverse effects with gabapentin were somnolence/drowsiness, unsteadiness, and dizziness. These adverse effects were most pronounced during the first 1-2 weeks of therapy, but resolved and were similar to those reported with placebo by week 4. These trials were short (<12 weeks) and had small sample sizes; however, their results appear to show that gabapentin is safe and effective for short-term treatment of hot flashes in women who have entered menopause either naturally or surgically.

Conclusions:

Gabapentin 600-2400 mg/day in divided doses may be a viable option for treating hot flashes in menopausal women who do not want to use hormone replacement therapy.
Oxytocin: recent developments
Authors: Tom Nicole C. , Assinder Stephen J.
Published: February 2011

Oxytocin is a neurohypophyseal hormone that is produced centrally by neurons in the paraventricular nucleus and supraoptic nucleus of the hypothalamus. It is released directly into higher brain centres and into the peripheral circulation where it produces a multitude of effects. Classically, oxytocin is known for inducing uterine contractions at parturition and milk ejection during suckling. Oxytocin also acts in a species and gender specific manner as an important neuromodulator. It can affect behaviours associated with stress and anxiety, as well social behaviours including sexual and relationship behaviours, and maternal care. Additionally, oxytocin has been shown to have a variety of physiological roles in peripheral tissues, many of which appear to be modulated largely by locally produced oxytocin, dispelling the notion that oxytocin is a purely neurohypophyseal hormone. Oxytocin levels are altered in several diseases and the use of oxytocin or its antagonists have been identified as a possible clinical intervention in the treatment of mood disorders and pain conditions, some cancers, benign prostatic disease and osteoporosis. Indeed, oxytocin has already been successful in clinical trials to treat autism and schizophrenia. This review will report briefly on the known functions of oxytocin, it will discuss in depth the data from recent clinical trials and highlight future targets for oxytocinergic modulation.
Pseudohypocalcemia caused by perchlorate (Irenat®)
Authors: Durner Jürgen , Winkler-Budenhofer Ursula , Gahr Simon , Samtleben Walter , Schönermarck Ulf
Published: February 2011

Background: Blood gas analysis (BGA), including measurement of ionized calcium, is performed routinely in patients with end stage renal disease on renal replacement therapy, especially when using citrate for regional anticoagulation. After installation of a new blood gas analyzer (RAPIDpoint® 405; BGA), we observed lower ionized calcium concentrations in a few patients without signs of hypocalcemia, whereas calcium concentrations were normal using a standard laboratory method. Pseudohypocalcemia was of limited duration and correlated with the short-term intake of sodium perchlorate monohydrate (Irenat®).

Methods: We prepared dilution series from whole blood samples and stock solutions of calcium and perchlorate with different concentrations of ionized calcium and perchlorate. Measurement of ionized calcium concentrations was performed using two different blood gas analyzers (RAPIDpoint® 405; BGA and Roche AVL 9180; standard laboratory method).

Results: After addition of different amounts of perchlorate, significant lower ionized calcium concentrations were measured with BGA compared to the standard laboratory method using either preparations from whole blood samples or stock solutions. The addition of potassium or methylene blue known to complex perchlorate had no effect on the concentrations of ionized calcium measured with BGA. Using different mathematical methods, a calculation of the “real” ionized calcium concentration from the value measured with BGA was not possible.

Conclusions: Based on our experiments, we confirm the hypothesis that perchlorate can influence the measurement of ionized calcium by BGA. As the effect depends on the ion selective electrode that is used, it is advisable to test the blood gas analyzer with calcium and perchlorate solutions.
Cooperação interinstitucional no campo dapesquisa em estratégia
Authors: Rossoni Luciano , Ronaldo Guarido Filho Edson
Published: February 2011

Este artigo investiga a associação entre produção científica e a cooperação entre instituições que compõem o campo da pesquisa em estratégia. A partir de 765 artigos científicos publicados na área durante os anos de 2001 a 2006, utilizou-se a análise de redes sociais para estudar o relacionamento entre instituições considerando suas propriedades estruturais e posicionais, bem como suas implicações sobre a produção científica. Os resultados apontam para a existência de estruturas do tipo small worlds e centro-periferia, com desdobramentos importantes para a formação de capital social e para a estratifi cação da produção científica entre instituições, condicionada também por sua localização geográfica. Os resultados indicam, ainda, maior probabilidade de produção daquelas instituições mais colaborativas e que exercem papel de intermediação, evidenciando relação significativa entre centralidade e produção científica.
New Perspectives on the Treatment of Metastatic Renal Cell Carcinoma: An Introduction and Historical Overview
Authors: Motzer Robert J.
Published: February 2011

The content of the supplement is summarized, including a review of the pathogenesis and diagnosis of renal cell carcinoma and the efficacy and safety of the currently available targeted therapies.
Beyond Traditional Outcomes: Improving Quality of Life in Patients with Renal Cell Carcinoma
Authors: Cella David
Published: February 2011

The introduction of molecular targeted therapies for patients with metastatic renal cell carcinoma has provided treatment options that are more efficacious and better tolerated than cytokine therapy, the previous standard of care. These advances have led to renewed efforts to define the health-related quality of life (HRQOL) impact of disease status stabilization or improvement versus that of treatment-associated adverse events. The distinct classes of targeted agents have unique AE profiles related to their specific targets; therefore, treatment considerations should include the patient's pretreatment HRQOL along with the known HRQOL effects of each drug. With more second- and third-line treatment options available for patients with metastatic renal cell carcinoma, HRQOL outcomes in earlier lines of therapy may guide treatment decisions for subsequent therapy, as poor HRQOL at therapy onset predicts poor survival. Both general and disease-specific instruments are used in clinical trials to reveal the impact of treatment on patient-reported outcomes. In this article, the common instruments used to assess HRQOL and the HRQOL outcomes observed in pivotal trials of targeted therapies are reviewed. Current data indicate that first-line therapy with sunitinib and first-line therapy in poor-prognosis patients with temsirolimus provide improved HRQOL compared with interferon-α. First- and second-line therapy with pazopanib and second-line therapy with everolimus and sorafenib maintained HRQOL levels similar to placebo, indicating that these agents do not worsen HRQOL. The HRQOL effects of bevacizumab plus IFN-α have not been reported. As new agents enter clinical investigation, HRQOL data can help determine their overall role in treatment.
Action Research for the Health and Safety of Domestic Workers in Montreal: Using Numbers to Tell Stories and Effect Change
Authors: Hanley Jill , Premji Stephanie , Messing Karen , Lippel Katherine
Published: February 2011

In 2007, a Filipina organization in Quebec (PINAY) sought the help of university researchers to document the workplace health and safety experiences of domestic workers. Together, they surveyed 150 domestic workers and produced a report that generated interest from community groups, policymakers, and the media. In this article, we—the university researchers—offer a case study of community-university action research. We share the story of how one project contributed to academic knowledge of domestic workers' health and safety experiences and also to a related policy campaign. We describe how Quebec workers' compensation legislation excludes domestic workers, and we analyze the occupational health literature related to domestic work. Striking data related to workplace accidents and illnesses emerged from the survey, and interesting lessons were learned about how occupational health questions should be posed. We conclude with a description of the successful policy advocacy that was possible as an outcome of this project.
Gender, Aging, and Work: Aging Workers' Strategies to Confront the Demands of Production in Maquiladora Plants in Nogales, Mexico
Authors: Adarga Mireya Scarone , Becerril Leonor Cedillo , Champion Catalina Denman
Published: February 2011

This work is part of a qualitative socio-cultural investigation with a group of men and women 40 years and older in the maquila export industry in Nogales, Sonora, Mexico. In 1994, as a result of the North American Free Trade Agreement, maquila plants combined traditional intensive work methods with new “just in time” production norms that impacted work and health conditions, particularly in older, or aging, workers. The workers that were interviewed for this study show a reduction in their functional ability to work starting at 40 years of age. Work organization demands, general health conditions, and a decrease in physical abilities brings these 40-year-old workers to prematurely construct an image of themselves as aging workers and to develop coping strategies that vary by gender.
Cellular and Molecular Responses of Cultured Neurons to Stressful Stimuli
Authors: Chen Jun , Pan Hongna , Lipsky Robert H. , Pérez-Gómez Anabel , Cabrera-Garcia David , Fernández-Sánchez Maria Teresa , Novelli Antonello , Marini Ann M.
Published: February 2011

Synaptic function is critical for the brain to process experiences dictated by the environment requiring change over the lifetime of the organism. Experience-driven adaptation requires that receptors, signal transduction pathways, transcription and translational mechanisms within neurons respond rapidly over its lifetime. Adaptive responses communicated through the rapid firing of neurons are dependent upon the integrity and function of synapses. These rapid responses via adaptation underlie the organism's ability to perceive, learn, remember, calculate and plan. Glutamate, the endogenous neurotransmitter required for physiological excitation in the brain, is critically involved in neuronal adaptive responses and in the pathophysiology of neurodegenerative disorders. Using neuronal experimental systems, we will discuss how compounds with low dose effects mediated via glutamate receptors can result either in a neuroprotective or neurotoxic response. Because the brain has evolved to respond rapidly to environmental cues, exposure of neurons to stressful stimuli can result in a pivotal response toward either synaptic adaptation or dysfunction and neuronal cell death. Understanding how neurons adapt to stressful stimuli will provide important clues toward the development of strategies to protect the brain against neurodegeneration.
A study of the extraction kinetics of the minerals from the white lady's bedstraw (Galium mollugo L.) by using an artificial neural network
Authors: Milic Petar , Bekric Danijela , Milic Slavica , Rajkovic Katarina
Published: February 2011

The present work deals with the mineral composition of the extracts obtained
from lady's bedstraw (Galium mollugo L.) by maceration, extraction under
reflux (extraction at the boiling temperature of solvent) and ultrasonic
extraction, using atomic absorption spectrometry. The main goals of the work
were to evaluate the operation of an artificial neural network (ANN) of the
selected topology, to determine the parameters of a kinetic model of unsteady
diffusion of minerals through plant material, and to define the yield of
minerals as a function of the time of extraction and the yield of total
extract (resinoid). The ANN results showed a positive correlation with the
experimental data, so they could be used to examine the kinetics of
extraction of minerals from lady's bedstraw (G. mollugo), regardless of the
extraction technique. The yield of minerals (K, Ca and Mg) was correlated
with the time of extraction and the yield resinoid by a polynomial equation
of the first order in both variables.
Endogenous stem cell proliferation induced by intravenous hedgehog agonist administration after contusion in the adult rat spinal cord
Authors: Bambakidis Nicholas C. , Horn Eric M. , Nakaji Peter , Theodore Nicholas , Bless Elizabeth , Dellovade Tammy , Ma Chiyuan , Wang Xukui , Preul Mark C. , Coons Stephen W. , Spetzler Robert F. , Sonntag Volker K. H.
Published: February 2011

Object

Sonic hedgehog (Shh) is a glycoprotein molecule that upregulates the transcription factor Gli1. The Shh protein plays a critical role in the proliferation of endogenous neural precursor cells when directly injected into the spinal cord after a spinal cord injury in adult rodents. Small-molecule agonists of the hedgehog (Hh) pathway were used in an attempt to reproduce these findings through intravenous administration.

Methods

The expression of Gli1 was measured in rat spinal cord after the intravenous administration of an Hh agonist. Ten adult rats received a moderate contusion and were treated with either an Hh agonist (10 mg/kg, intravenously) or vehicle (5 rodents per group) 1 hour and 4 days after injury. The rats were killed 5 days postinjury. Tissue samples were immediately placed in fixative. Samples were immunohistochemically stained for neural precursor cells, and these cells were counted.

Results

Systemic dosing with an Hh agonist significantly upregulated Gli1 expression in the spinal cord (p < 0.005). After spinal contusion, animals treated with the Hh agonist had significantly more nestin-positive neural precursor cells around the rim of the lesion cavity than in vehicle-treated controls (means ± SDs, 46.9 ± 12.9 vs 20.9 ± 8.3 cells/hpf, respectively, p < 0.005). There was no significant difference in the area of white matter injury between the groups.

Conclusions

An intravenous Hh agonist at doses that upregulate spinal cord Gli1 transcription also increases the population of neural precursor cells after spinal cord injury in adult rats. These data support previous findings based on injections of Shh protein directly into the spinal cord.
Abdominal complications following kyphosis correction in ankylosing spondylitis
Authors: Sugrue Patrick A. , O'Shaughnessy Brian A. , Nasr Fadi , Koski Tyler R. , Ondra Stephen L.
Published: February 2011

Spinal deformity surgery is associated with high rates of morbidity and a wide range of complications. The most significant abdominal complications following kyphosis correction, while uncommon, can certainly pose significant infectious and hemodynamic risks to the patient. Abdominal compartment syndrome is the most severe of the sequelae. It is the end result of elevated abdominal compartment pressure with physiological compromise and end organ system dysfunction. Although most commonly associated with trauma, abdominal compartment syndrome has also been witnessed following massive fluid shifts, which can occur during adult spinal deformity surgery. In this manuscript, we report on 2 patients with ankylosing spondylitis who developed significant abdominal pathology requiring exploratory laparotomy following kyphosis correction. In addition to describing the details of each case, we propose explanations of the relevant pathophysiology and review diagnostic and treatment strategies for such events. The key to effectively treating such a debilitating complication is to recognize it quickly and intervene rapidly and aggressively.
Reconstruction of C-1 lateral mass with titanium mesh cage after resection of an aneurysmal bone cyst of the atlas
Authors: Wang Vincent Y. , Deviren Vedat , Ames Christopher P.
Published: February 2011

Aneurysmal bone cysts (ABCs) are rare benign tumors with a prevalence of 0.14 cases per 100,000 people. A majority of cases arise during adolescence, and there is a female predominance. This lesion accounts for 1.4% of all primary bone tumors. Aneurysmal bone cysts occur mainly in the long bones, with spinal involvement in 10–30% of cases. Cervical spine ABCs account for about one-third of spinal ABCs, and atlas involvement occurs in 1% of cases. Resection of ABCs at the atlas is difficult because of the location and the lack of proper instrumentation for reconstruction of C-1. The authors present a case of an ABC at C-1 in a child who underwent resection of the lesion and reconstruction of the lateral mass with a titanium mesh cage.
Cervical myelopathy in patients with ossification of the posterior longitudinal ligament
Authors: Mochizuki Macondo , Aiba Atsuomi , Hashimoto Mitsuhiro , Fujiyoshi Takayuki , Yamazaki Masashi
Published: February 2011

Object

The authors assessed the clinical course in patients with a narrowed cervical spinal canal caused by ossification of the posterior longitudinal ligament (OPLL), but who have no or only mild myelopathy. Additionally, the authors analyzed the factors contributing to the development and aggravation of myelopathy in patients with OPLLinduced spinal canal stenosis.

Methods

Between 1997 and 2004, the authors selected treatments for patients with cervical OPLL in whom the residual space available for the spinal cord was ≤ 12 mm. Treatment decisions were based on the severity of myelopathy at presentation. Twenty-one patients with no or mild myelopathy (defined as a Japanese Orthopaedic Association [JOA] scale score ≥ 14 points) received conservative treatment, with a mean follow-up period of 4.5 years. In 20 patients with moderate or severe myelopathy (JOA scale score < 14 points), the authors performed surgery via an anterior approach. The clinical course in these patients was assessed with the JOA scale and the OPLL types were classified. The authors evaluated the range of motion between C-1 and C-7, the developmental segmental sagittal diameter, the percentage of spinal canal diameter occupied by the OPLL (% ratio), and the residual space available for the spinal cord on cervical radiographs; T2-weighted MR images were examined for high signal changes (HSCs).

Results

In the conservative treatment group, 8 patients showed improvement, 12 remained unchanged, and 1 patient's condition became slightly worse during the observation period. Fifteen patients in this group had mixedtype, 3 had continuous-type, 2 had localized-type, and 1 had a segmental-type OPLL. In the surgically treated group, there were 12 patients with segmental-type, 10 patients with mixed-type, and 1 with localized-type OPLL. The mean range of motion at C1–7 was 36.4° in the conservatively treated group and 46.5° in the surgical group (p < 0.05). No significant difference was seen between the groups in terms of developmental segmental sagittal diameter, % ratio, or residual space available for the cord. No HSCs were noted in the conservative group, while 17 patients in the surgical group had HSCs (p < 0.05).

Conclusions

In the present study, the authors demonstrate that the mobility of the cervical spine and the type of OPLL are important factors contributing to the development and aggravation of myelopathy in patients with OPLLinduced spinal canal stenosis. The authors advocate conservative treatment in most patients with OPLLs who have no or only mild myelopathy, even in the presence of spinal canal narrowing.
Isolated unilateral hypoglossal nerve palsy secondary to an atlantooccipital joint juxtafacet synovial cyst
Authors: Elhammady Mohamed Samy , Farhat Hamad , Aziz-Sultan Mohammad Ali , Morcos Jacques J.
Published: February 2011

Juxtafacet cysts of the atlantooccipital joint that present with isolated hypoglossal nerve palsy are rare and may mimic more common pathological entities. The authors report on the third such case in the literature and discuss the differential diagnosis, imaging hallmarks, preoperative recognition, and surgical management of this lesion, and provide a review of the literature.

The authors discuss their experience with the treatment of a 67-year-old woman who presented with an isolated hypoglossal nerve palsy caused by a nonenhancing cystic septated lesion abutting the lateral medulla just medial to the left hypoglossal canal. The lesion was presumed to be a necrotic hypoglossal schwannoma or epidermoid tumor. Intradural surgical exploration failed to demonstrate an intradural lesion, but confirmed the presence of an extradural mass caudal to the hypoglossal nerve. Extradural exploration revealed a synovial cyst of the atlantooccipital joint, which was then resected. Postoperatively, the patient developed worsening dysphagia and hoarseness. Failure to recognize this rare entity preoperatively resulted in unnecessary intradural exploration and cranial nerve morbidity. In retrospect, the preoperative diagnosis of this lesion was suggested by lack of central enhancement, absence of dumbbell formation and the presence of erosive synovial changes. Regardless, the extreme rarity of this lesion at this location will always make its recognition challenging.