bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of postpartum depression by sociodemographic, obstetric and psychological factors: A prospective study
Authors: Kim Yong‐Ku , Hur Ji‐Won , Kim Kye‐Hyun , Oh Kang‐Sub , Shin Young‐Chul
Published: June 2008

Aim:  Many studies have documented serious effects of postpartum depression. This prospective study sought to determine predictive factors for postpartum depression.

Methods:  Pregnant women (n = 239) were enrolled before 24 weeks in their pregnancy. At 6 weeks postpartum, 30 women who had postpartum depression and 30 non‐depressed mothers were selected. The Edinburgh Postnatal Depression Scale (EPDS), the Beck Depression Inventory (BDI), the Beck Anxiety Inventory (BAI), the Rosenberg Self‐Esteem Scale (RSES) Marital Satisfaction Scale (MSS), and the Childcare Stress Inventory (CSI) were administered to all 60 mothers at 24 weeks pregnancy, 1 week postpartum, and 6 weeks postpartum.

Results:  The differences in most of the diverse sociodemographic and obstetric factors assessed were not statistically significant. There were significant differences in MSS scores at 24 weeks pregnancy (P = 0.003), and EPDS (P < 0.001; P = 0.002), BDI (P = 0.001; P = 0.031), and BAI (P < 0.001; P < 0.001) at both 24 weeks pregnant and 1 week postpartum, while there was no significant difference in the RSES scores at 24 weeks pregnant (P = 0.065). A logistic regression analysis was performed on the following factors: ‘depressive symptoms immediately after delivery’ (EPDS and BDI at 1 week postpartum), ‘anxiety’ (BAI prepartum), ‘stress factors from relationships’ (MSS prepartum and CSI at 1 week postpartum) or ‘self‐esteem’ (RSES prepartum). When these four factors were added individually to a model of the prepartum depressive symptoms (EPDS and BDI prepartum), no additional effect was found.

Conclusions:  The optimum psychological predictor is prepartum depression, and other psychological measures appear to bring no significant additional predictive power.
No association between the ryanodine receptor 3 gene and autism in a Japanese population
Authors: Tochigi Mamoru , Kato Chieko , Ohashi Jun , Koishi Shinko , Kawakubo Yuki , Yamamoto Kenji , Matsumoto Hideo , Hashimoto Ohiko , Kim Soo‐Yung , Watanabe Keiichiro , Kano Yukiko , Nanba Eiji , Kato Nobumasa , Sasaki Tsukasa
Published: June 2008

Aim:  Autism is a neurodevelopmental disorder with a complex genetic etiology. Chromosome 15q11‐q14 has been proposed to harbor a gene for autism susceptibility because deletion of the region leads to Prader‐Willi syndrome or Angelman syndrome, having phenotypic overlap with autism. Here we studied the association between autism and the ryanodine receptor 3 (RyR3) gene, which is located in the region. This is the first study, to our knowledge, that has investigated the association.

Methods:  We genotyped 14 tag single nucleotide polymorphisms (SNPs) in 166 Japanese patients with autism and 375 controls.

Results:  No significant difference was observed between the patients and controls in allelic frequencies or genotypic distributions of the 14 SNPs. Analysis after confining the subjects to males showed similar results.

Conclusions:  The present study provides no positive evidence for the association between the RyR3 gene and autism in the Japanese population.
Trait aggression in suicide attempters: A pilot study
Authors: Doihara Chiho , Kawanishi Chiaki , Yamada Tomoki , Sato Ryoko , Hasegawa Hana , Furuno Taku , Nakagawa Makiko , Hirayasu Yoshio
Published: June 2008

Suicide attempt is a potent risk factor of subsequent suicide. Understanding the characteristics of suicide attempters is important for preventing suicide. The authors investigated aggression in medically serious suicide attempters at an emergency department. Trait aggression was evaluated in 55 suicide attempters and 71 healthy individuals as a control group using the Japanese version of the Buss‐Perry Aggression Questionnaire (BAQ). Total BAQ scores (t = 2.782, P = 0.006) and the hostility scores (t = 3.735, P < 0.001) were significantly higher in the suicide attempters than the controls. It suggested that to focus on aggression and its management is one of the key components for preventing suicide.
Diabetic ketoacidosis in pregnancy tends to occur at lower blood glucose levels: Case–control study and a case report of euglycemic diabetic ketoacidosis in pregnancy
Authors: Guo Rui‐Xia , Yang Ling‐Zhu , Li Liu‐Xia , Zhao Xue‐Ping
Published: June 2008

Background and Objective:  The occurrence of diabetic ketoacidosis (DKA) during pregnancy is considered a medical emergency. The aims of the present study were to evaluate the incidence of DKA in pregnant and non‐pregnant women with diabetes; to compare the blood glucose levels at the diagnosis of DKA in pregnant and non‐pregnant women; and to show a case of euglycemic DKA in pregnancy.

Methods:  The subjects consisted of 90 cases of DKA in pregnant women with diabetes and 286 cases of non‐pregnant female inpatients receiving treatment for diabetes during 2001 to 2005 in our hospital. The incidence of DKA in pregnant and non‐pregnant women with diabetes and the blood glucose levels at the diagnosis of DKA in pregnant and non‐pregnant women were compared.

Results:  DKA had a higher incidence in pregnant women with diabetes (8/90, 8.9%) than in non‐pregnant women with diabetes (9/286, 3.1%) (P < 0.05). The blood glucose levels (mmol/L) in pregnant women with DKA were significantly lower than those in non‐pregnant women with DKA (16.3 ± 4.6 vs 27.5 ± 4.8, P < 0.001). A case of euglycemic DKA in pregnancy was described whose serum glucose level was only 6.9 mmol/L.

Conclusions:  DKA in pregnant women with diabetes may occur more frequently, and at lower blood glucose levels than DKA in non‐pregnant women with diabetes.
Primary ovarian pregnancy after the empty follicle syndrome: A case report
Authors: Qublan Hussein , Tahat Yousef , Al‐Masri Anwar
Published: June 2008

A32‐year‐old nulligravida woman underwent in vitro fertilization treatment because of 6 years of unexplained infertility. On the day of ovum pick‐up, no eggs were retrieved and the patient was diagnosed to have empty follicle syndrome. Six weeks later, she presented with left lower abdominal pain and mild vaginal bleeding. Laboratory tests and diagnostic laparoscopy revealed left ovarian pregnancy. Left oophorectomy was performed and the histopathological examination confirmed the diagnosis.
Neurogenesis, learning and associative strength
Authors: Waddell Jaylyn , Shors Tracey J.
Published: June 2008

Though the role of the hippocampus in processes of learning and memory is well established, the role of new neurons generated there is less understood. Training on some associative learning tasks increases the likelihood that new cells in the subgranular zone of the dentate gyrus will survive. In the rat, an effective training procedure is trace eyeblink conditioning, in which a conditioned stimulus (CS) is paired with an aversive stimulation to the eyelid (unconditioned stimulus; US), but the stimuli are separated by a temporal gap. Here, we manipulated the asymptote or rate of acquisition during trace conditioning, and examined survival of cells generated 1 week before training. Acquisition was disrupted by decreasing associative strength by insertion of unpredicted USs or slowed with latent inhibition. The number of cells was increased in animals that were trained with trace conditioning, irrespective of the decrease in associative strength or slowed acquisition. Disrupting acquisition with unsignaled USs still increased cell numbers, suggesting that the learning effect on cell survival is not dependent on reliable expression of the conditioned response. Further, animals in the latent inhibition conditions that learned but required more trials also retained more of the new cells than animals requiring fewer trials. The number of cells that survived after the effective training procedures was similar to the number of cells that were available for rescue at the beginning of training. Thus, learning can rescue the majority of cells expressed at the beginning of training, and does so most effectively when acquisition requires many trials.
Prenatal nicotine exposure changes natural and drug‐induced reinforcement in adolescent male rats
Authors: Franke Ryan M. , Park Minjung , Belluzzi James D. , Leslie Frances M.
Published: June 2008

Clinical studies have demonstrated an increased incidence of substance misuse and obesity in adolescents whose mothers smoked during pregnancy. Although dopamine systems that mediate natural and drug‐induced reinforcement have been shown in animal studies to be altered by gestational nicotine treatment, it is not clear whether there are concomitant changes in reinforcement sensitivity. To test whether prenatal nicotine exposure influences sensitivity to natural and drug rewards, timed pregnant rats were implanted with osmotic minipumps delivering saline or nicotine (3 mg/kg/day) from gestational day 4 to 18. Male offspring were tested as adolescents, on postnatal day 32, for operant responding maintained by sucrose pellets or i.v. cocaine (200 or 500 μg/kg per injection). Cocaine‐induced stereotypy andc‐fosmRNA expression in cortex and striatum were also examined. Complex changes in reward circuitry were observed in the offspring of nicotine‐exposed dams. Nicotine‐exposed adolescents did not self‐administer the low dose of cocaine, but, at the higher dose, exhibited significantly greater cocaine intake andc‐fosmRNA expression in nucleus accumbens than did controls. In contrast, control animals showed significantly greater drug‐induced stereotypy at both cocaine doses. Operant responding maintained by sucrose was also influenced by gestational nicotine exposure. At a fixed ratio (FR) 1 schedule, although the number of pellets eaten by the two experimental groups was equivalent, more pellets were left uneaten by nicotine‐exposed offspring. At FR2 and FR5 schedules, the responding maintained by sucrose pellets was lower in nicotine‐exposed offspring. These findings suggest that nicotine exposure during gestation may induce changes in both natural and drug reward pathways.
Juvenile methylphenidate modulates reward‐related behaviors and cerebral blood flow by decreasing cortical D3 receptors
Authors: Andersen Susan L. , Napierata Lee , Brenhouse Heather C. , Sonntag Kai C.
Published: June 2008

Attention deficit hyperactivity disorder is associated with reduced cortical blood flow that is reversible with exposure to the psychostimulant methylphenidate (MPH). D3 dopamine receptors modulate stimulant‐induced changes in blood flow and are associated with reward processing during young adulthood, but their role in the enduring effects of MPH during development is unknown. Rats were given vehicle (VEH) or MPH (2 mg/kg between postnatal days 20–35) and assessed in young adulthood for regional cerebral blood volume (rCBV) after MPH challenge and mRNA expression levels of dopamine receptors. To probe D3 receptor involvement, juvenile subjects were exposed to VEH, MPH, the D3‐preferring agonist ±7‐OHDPAT (0.3 mg/kg), the D3 antagonist nafadotride (Naf; 0.05, 0.5 or 5.0 mg/kg) or a Naf (0.05 mg/kg)/MPH combination, and assessed biochemically and behaviorally. Juvenile MPH exposure increased MPH‐induced rCBV in the cingulate and medial prefrontal cortex and thalamus in adulthood. Behaviorally, juvenile MPH‐ or ±7‐OHDPAT‐exposed subjects demonstrated an aversion to cocaine‐associated environments, which was prevented by juvenile co‐treatment with MPH and Naf, or with adult cortical microinjections of ±7‐OHDPAT. Cortical D3 mRNA levels significantly decreased by 23.8 ± 6.7% in MPH‐treated subjects and normalized with combined Naf/MPH treatment, with no change in the other dopamine receptors. Enhanced cortical responsiveness to psychostimulants may occur through a reduction in D3 receptors, which in turn reduces drug‐seeking behavior. These data provide evidence for a postnatal sensitive period when juvenile MPH exposure is able to alter cortical development.
Protein degradation, as with protein synthesis, is required during not only long‐term spatial memory consolidation but also reconsolidation
Authors: Artinian Julien , McGauran Anne‐Marie T. , De Jaeger Xavier , Mouledous Lionel , Frances Bernard , Roullet Pascal
Published: June 2008

The formation of long‐term memory requires protein synthesis, particularly during initial memory consolidation. This process also seems to be dependant upon protein degradation, particularly degradation by the ubiquitin‐proteasome system. The aim of this study was to investigate the temporal requirement of protein synthesis and degradation during the initial consolidation of allocentric spatial learning. As memory returns to a labile state during reactivation, we also focus on the role of protein synthesis and degradation during memory reconsolidation of this spatial learning. Male CD1 mice were submitted to massed training in the spatial version of the Morris water maze. At various time intervals after initial acquisition or after a reactivation trial taking place 24 h after acquisition, mice received an injection of either the protein synthesis inhibitor anisomycin or the protein degradation inhibitor lactacystin. This injection was performed into the hippocampal CA3 region, which is specifically implicated in the processing of spatial information. Results show that, in the CA3 hippocampal region, consolidation of an allocentric spatial learning task requires two waves of protein synthesis taking place immediately and 4 h after acquisition, whereas reconsolidation requires only the first wave. However, for protein degradation, both consolidation and reconsolidation require only one wave, taking place immediately after acquisition or reactivation, respectively. These findings suggest that protein degradation is a key step for memory reconsolidation, as for consolidation. Moreover, as protein synthesis‐dependent reconsolidation occurred faster than consolidation, reconsolidation did not consist of a simple repetition of the initial consolidation.
Adaptations in endocannabinoid signaling in response to repeated homotypic stress: a novel mechanism for stress habituation
Authors: Patel Sachin , Hillard Cecilia J.
Published: June 2008

Daily life stressors are a major environmental factor contributing to precipitation and exacerbation of mental illness. Animal models using repeated homotypic stress induce anxious and depressive phenotypes and are used to study the pathophysiology of affective disorders. Here we discuss data demonstrating that repeated homotypic stress produces temporally and anatomically distinct changes in endocannabinoid signaling components within stress‐responsive brain regions. We also present evidence describing the neural and behavioral correlates of these adaptations in endocannabinoid signaling. These data support a role for endocannabinoid signaling in the central nervous system response to chronic, homotypic stress, and specifically in the process of stress–response habituation. The clinical implications of these findings for the pathophysiology and treatment of affective disorders are discussed.
Mu‐opioid receptor activation induces transcriptional plasticity in the central extended amygdala
Authors: Befort K. , Filliol D. , Ghate A. , Darcq E. , Matifas A. , Muller J. , Lardenois A. , Thibault C. , Dembele D. , Le Merrer J. , Becker J. A. J. , Poch O. , Kieffer B. L.
Published: June 2008

Addiction develops from the gradual adaptation of the brain to chronic drug exposure, and involves genetic reprogramming of neuronal function. The central extended amygdala (EAc) is a network formed by the central amygdala and the bed nucleus of the stria terminalis. This key site controls drug craving and seeking behaviors, and has not been investigated at the gene regulation level. We used Affymetrix microarrays to analyze transcriptional activity in the murine EAc, with a focus on mu‐opioid receptor‐associated events because these receptors mediate drug reward and dependence. We identified 132 genes whose expression is regulated by a chronic escalating morphine regimen in the EAc from wild‐type but not mu‐opioid receptor knockout mice. These modifications are mostly EAc‐specific. Gene ontology analysis reveals an overrepresentation of neurogenesis, cell growth and signaling protein categories. A separate quantitative PCR analysis of genes in the last of these groups confirms the dysregulation of both orphan (Gpr88) and known (DrD1A,Adora2A,Cnr1,Grm5,Gpr6) G protein‐coupled receptors, scaffolding (PSD95,Homer1) and signaling (Sgk,Cap1) proteins, and neuropeptides (CCK,galanin). These transcriptional modifications do not occur following a single morphine injection, and hence result from long‐term adaptation to excessive mu receptor activation. Proteins encoded by these genes are classically associated with spine modules function in other brain areas, and therefore our data suggest a remodeling of EAc circuits at sites where glutamatergic and monoaminergic afferences interact. Together, mu receptor‐dependent genes identified in this study potentially contribute to drug‐induced neural plasticity, and provide a unique molecular repertoire towards understanding drug craving and relapse.
GABAergic mechanism mediated via D1receptors in the rat periaqueductal gray participates in the micturition reflex: anin vivomicrodialysis study
Authors: Kitta Takeya , Matsumoto Machiko , Tanaka Hiroshi , Mitsui Takahiko , Yoshioka Mitsuhiro , Nonomura Katsuya
Published: June 2008

The periaqueductal gray (PAG) is critically involved in the micturition reflex, but little is known about the neuronal mechanisms involved. The present study elucidated dynamic changes in dopamine (DA), glutamate and γ‐aminobutyric acid (GABA) in the rat PAG during the micturition reflex, with a focus on dopaminergic modulation usingin vivomicrodialysis combined with cystometrography. Extracellular levels of DA and glutamate increased, whereas levels of GABA decreased, in parallel with the micturition reflex. Application of a D1receptor antagonist into the PAG produced increases in maximal voiding pressure (MVP) and decreases in intercontraction interval (ICI), suggesting that the micturition reflex was facilitated by D1receptor blockade. The D1receptor antagonist prevented micturition‐induced decreases in GABA efflux but had no effect on DA or glutamate. Neither a D2receptor antagonist nor a D1/D2receptor agonist affected these neurochemical and physiological parameters. Micturition‐induced inhibition of GABA was not observed in 6‐hydroxydopamine (6‐OHDA)‐lesioned rats, an animal model of Parkinson’s disease. 6‐OHDA‐lesioned rats exhibited bladder hyperactivity evaluated by increases in MVP and decreases in ICI, mimicking facilitation of the micturition reflex induced by D1receptor blockade. These findings suggest that the micturition reflex is under tonic dopaminergic regulation through D1receptors, in which a GABAergic mechanism is involved. Bladder hyperactivity observed in 6‐OHDA‐lesioned rats may be caused by dysfunction of GABAergic regulation underlying the micturition reflex. The present findings contribute to our understanding not only of the neurophysiology of the micturition reflex but also of the pathophysiology of lower urinary tract dysfunction in patients with Parkinson’s disease.
Synaptogenesis in the mouse olfactory bulb during glomerulus development
Authors: Blanchart Albert , Romaguera Miriam , García‐Verdugo Jose M. , De Carlos Juan A. , López‐Mascaraque Laura
Published: June 2008

Synaptogenesis is essential for the development of neuronal networks in the brain. In the olfactory bulb (OB) glomeruli, numerous synapses must form between sensory olfactory neurons and the dendrites of mitral/tufted and periglomerular cells. Glomeruli develop from E13 to E16 in the mouse, coincident with an increment of the neuropil in the border between the external plexiform (EPL) and olfactory nerve layers (ONL), coupled to an extensive labelling of phalloidin and GAP‐43 from the ONL to EPL. We have tracked synaptogenesis in the OB during this period by electron microscopy (EM) and immunolabelling of the transmembrane synaptic vesicle glycoprotein SV‐2. No SV‐2 labelling or synapses were detected at E13, although electrodense junctions lacking synaptic vesicles could be observed by EM. At E14, sparse SV‐2 labelling appears in the most ventral and medial part of the incipient OB, which displays a ventro‐dorsal gradient by E15 but covers the entire OB by E16. These data establish a spatio‐temporal pattern of synaptogenesis, which perfectly matches with the glomeruli formation in developing OB.
Individual differences in disgust sensitivity modulate neural responses to aversive/disgusting stimuli
Authors: Mataix‐Cols David , An Suk Kyoon , Lawrence Natalia S. , Caseras Xavier , Speckens Anne , Giampietro Vincent , Brammer Michael J. , Phillips Mary L.
Published: June 2008

Little is known about how individual differences in trait disgust sensitivity modulate the neural responses to disgusting stimuli in the brain. Thirty‐seven adult healthy volunteers completed the Disgust Scale (DS) and viewed alternating blocks of disgusting and neutral pictures from the International Affective Picture System while undergoing fMRI scanning. DS scores correlated positively with activations in brain regions previously associated with disgust (anterior insula, ventrolateral prefrontal cortex–temporal pole, putamen–globus pallidus, dorsal anterior cingulate, and visual cortex) and negatively with brain regions involved in the regulation of emotions (dorsolateral and rostral prefrontal cortices). The results were not confounded by biological sex, anxiety or depression scores, which were statistically controlled for. Disgust sensitivity, a behavioral trait that is normally distributed in the general population, predicts the magnitude of the individual’s neural responses to a broad range of disgusting stimuli. The results have implications for disgust‐related psychiatric disorders.
Progression of benign prostatic hyperplasia: systematic review of the placebo arms of clinical trials
Authors: Emberton Mark , Fitzpatrick John M. , Garcia‐Losa Manuel , Qizilbash Nawab , Djavan Bob
Published: June 2008

OBJECTIVE

To systematically review the placebo arms of randomized trials of medical therapy for benign prostatic hyperplasia (BPH) and thus estimate rates of progression.

METHODS

We searched PubMed, the Cochrane Trials Register and the USA Food and Drug Administration website. Retrieved citations were reviewed in two stages: a title and abstract screen, followed by a review of selected full‐length articles. The inclusion criterion for studies were trials of BPH with >100 patients in the placebo group.

RESULTS

From 1774 citations screened, 16 eligible studies were found with a total of 12 158 patients. The range of mean baseline age was 62.6–66.5 years, for prostate volume 33.9–61.0 mL and for maximum urinary flow 8.6–11.6 mL/s. With studies spanning 12–48 months, the rates of surgery were 1–10% and for acute urinary retention 0.4–6.6%. Most studies showed progression, based on a worsening in clinical outcomes of the change from baseline in prostate volume and maximum urinary flow. Statistical heterogeneity prevented a quantitative synthesis of the data.

CONCLUSION

This systematic review confirms BPH disease progression in the form of increased prostate volume, reduction in maximum urinary flow rate and an increase in the risk of acute urinary retention and surgery. To provide quantitative estimates of effect, access to data from individual participants would be required.
Antitumour effect of electrochemotherapy with bleomycin on human prostate cancer xenograft
Authors: Ueki Tei‐ichiro , Uemura Hiroji , Nagashima Yoji , Ohta Shinsuke , Ishiguro Hitoshi , Kubota Yoshinobu
Published: June 2008

OBJECTIVE

To investigate the antitumour effect of electroporation (EP), a drug delivery system that has been shown to be effective synergistically with antitumour drugs, with bleomycin on the growth of prostate cancer xenografts in nude mice.

MATERIALS AND METHODS

PC‐3 cells were implanted subcutaneously into nude mice. After determination of the optimal conditions of electric pulse voltage and bleomycin dose, tumour growth in mice treated with EP plus bleomycin was compared with that in mice receiving EP alone, bleomycin alone or no treatment. In all four groups, apoptosis in the tumours was assessed.

RESULTS

There was a significant reduction in tumour growth in mice that received EP with bleomycin. Apoptotic cells in tumours at 24 h after treatment with EP plus bleomycin showed a significant difference compared with the other three groups, but not at 12 h after treatment.

CONCLUSIONS

These results indicate the possibility that EP with bleomycin could be effective as an ablation therapy for prostate cancer, especially androgen‐independent cancer.
PRICING DISCRETELY MONITORED BARRIER OPTIONS AND DEFAULTABLE BONDS IN LÉVY PROCESS MODELS: A FAST HILBERT TRANSFORM APPROACH
Authors: Feng Liming , Linetsky Vadim
Published: June 2008

This paper presents a novel method to price discretely monitored single‐ and double‐barrier options in Lévy process‐based models. The method involves a sequential evaluation of Hilbert transforms of the product of the Fourier transform of the value function at the previous barrier monitoring date and the characteristic function of the (Esscher transformed) Lévy process. A discrete approximation with exponentially decaying errors is developed based on the Whittaker cardinal series (Sinc expansion) in Hardy spaces of functions analytic in a strip. An efficient computational algorithm is developed based on the fast Hilbert transform that, in turn, relies on the FFT‐based Toeplitz matrix–vector multiplication. Our method also provides a natural framework for credit risk applications, where the firm value follows an exponential Lévy process and default occurs at the first time the firm value is below the default barrier on one of a discrete set of monitoring dates.
BEHAVIORAL PORTFOLIO SELECTION IN CONTINUOUS TIME
Authors: Jin Hanqing , Yu Zhou Xun
Published: June 2008

This paper formulates and studies a general continuous‐time behavioral portfolio selection model under Kahneman and Tversky's (cumulative) prospect theory, featuring S‐shaped utility (value) functions and probability distortions. Unlike the conventional expected utility maximization model, such a behavioral model could be easily mis‐formulated (a.k.a. ill‐posed) if its different components do not coordinate well with each other. Certain classes of an ill‐posed model are identified. A systematic approach, which is fundamentally different from the ones employed for the utility model, is developed to solve a well‐posed model, assuming a complete market and general Itô processes for asset prices. The optimal terminal wealth positions, derived in fairly explicit forms, possess surprisingly simple structure reminiscent of a gambling policy betting on a good state of the world while accepting a fixed, known loss in case of a bad one. An example with a two‐piece CRRA utility is presented to illustrate the general results obtained, and is solved completely for all admissible parameters. The effect of the behavioral criterion on the risky allocations is finally discussed.
BIVARIATE SUPPORT OF FORWARD LIBOR AND SWAP RATES
Authors: Jamshidian Farshid
Published: June 2008

Based on a certain notion of “prolific process,” we find an explicit expression for the bivariate (topological) support of the solution to a particular class of 2 × 2 stochastic differential equations that includes those of the three‐period “lognormal” Libor and swap market models. This yields that in the lognormal swap market model (SMM), the support of the 1 × 1 forward Libor L*t equals [l*t, ∞) for some semi‐explicit −1 ≤l*t≤ 0, sharpening a result of Davis and Mataix‐Pastor (2007) that forward Libor rates (eventually) become negative with positive probability in the lognormal SMM. We classify the instances l*t < 0, and explicitly calculate the threshold time at or before which L*t remains positive a.s.
M129V polymorphism in the prion protein gene is not associated with mesial temporal lobe epilepsy in a Han Chinese population
Authors: Wang X. , Sun W. , Zhu X. , Wu X. , Li L. , Zhu S. , Du T. , Liu Y. , Niu N. , Wang Y. , Liu Y.
Published: June 2008

Background and purpose:  Prion protein (PrP) predominantly localized at synapses can modulate neuronal excitability. The prion protein gene (PRNP) has been considered one of the candidate genes that play a role in seizure susceptibility. A recent study demonstrated that the 129V allele in the PRNP gene was associated with susceptibility to temporal lobe epilepsy (TLE) in female patients in an Italian population. We screened variations in the open‐reading frame (ORF) of the PRNP gene and also replicated the association of the M129V polymorphism with TLE in a Han Chinese population.

Methods:  The M129V polymorphism was genotyped in 320 MTLE patients and 558 non‐epilepsy controls. All subjects were Han Chinese.

Results:  No novel polymorphism in the ORF of the PRNP gene was detected. Differences in the genotype distributions and allele frequencies of this polymorphism between cases and controls were insignificant (P = 0.24). Further analysis with stratification of the results by gender or age and analysis of clinical features in relation to M129V genotypes also yielded negative findings.

Conclusions:  The present study provides evidence that the M129V polymorphism in the PRNP gene is not associated with MTLE in a Han Chinese population.
Idiopathic polyneuropathy and impaired glucose metabolism in a Norwegian patient series
Authors: Nebuchennykh M. , Løseth S. , Jorde R. , Mellgren S. I.
Published: June 2008

Background and purpose:  North American studies have indicated a high prevalence of impaired glucose tolerance (IGT) in patients with sensory polyneuropathy. We searched for the occurrence of IGT in a Norwegian patient material with polyneuropathy.

Methods:  Seventy patients with symptoms and signs of sensory polyneuropathy were included. Cases with known causes of neuropathy were excluded. All patients underwent a 2 h oral glucose tolerance test (OGTT). Nerve conduction studies (NCS), quantitative sensory testing (QST) and skin biopsy with assessment of intra‐epidermal nerve fibre (IENF) density were performed.

Results:  Sixteen patients (23%) had impaired glucose metabolism (IGM): 2 (3%) were found to have diabetes, 9 (13%) had IGT, 3 (4%) had impaired fasting glucose (IFG) and 2 (3%) both IFG and IGT. About 62% of the patients with IGM and polyneuropathy and 50% of those with chronic idiopathic axonal polyneuropathy (CIAP) had abnormalities on NCS. Reduction of IENF occurred in 37% of the patients with IGM and 43% of those with CIAP.

Conclusions:  Patients with polyneuropathy and IGM had essentially the same degree of involvement of small and large nerve fibres as patients with CIAP. IGT seems less frequent in Norwegian patients with polyneuropathy than reported in North American populations.
Enhanced CREB and DARPP‐32 phosphorylation in the nucleus accumbens and CREB, ERK, and GluR1 phosphorylation in the dorsal hippocampus is associated with cocaine‐conditioned place preference behavior
Authors: Tropea Thomas F. , Kosofsky Barry E. , Rajadhyaksha Anjali M.
Published: June 2008

Environment‐induced relapse is a major concern in drug addiction because of the strong associations formed between drug reward and environment. Cocaine‐conditioned place preference is an ideal experimental tool to examine adaptations in the molecular pathways that are activated upon re‐exposure to an environment previously paired with drug reward. To better understand the mechanism of cocaine‐conditioned place preference we have used western blot analysis to examine changes in phosphorylation of cAMP‐response element binding protein (CREB), dopamine‐ and cyclic AMP‐regulated phosphoprotein 32 (DARPP‐32), extracellular signal‐regulated kinase (ERK) and GluR1, key molecular substrates altered by cocaine, in the nucleus accumbens (NAc) and dorsal hippocampus (DHC) of C57BL/6 mice. Our studies revealed that re‐exposing mice to an environment in which they were previously given cocaine resulted in increased levels of Ser133 phospho‐CREB and Thr34 phospho‐DARPP‐32 with a corresponding decrease in Thr75 phospho‐DARPP‐32 in the NAc. In DHC there were increased levels of phospho‐CREB, Thr183/Tyr185 phospho‐ERK, and Ser845 phospho‐GluR1. These data suggest that the formation of contextual drug reward associations involves recruitment of the DHC‐NAc circuit with activation of the DARPP‐32/CREB pathway in the NAc and the ERK/CREB pathway in the DHC.
Clusterin increases post‐ischemic damages in organotypic hippocampal slice cultures
Authors: Hakkoum David , Imhof Anouk , Vallet Philippe G. , Boze Helène , Moulin Guy , Charnay Yves , Stoppini Luc , Aronow Bruce , Bouras Constantin , Giannakopoulos Panteleimon
Published: June 2008

Clusterin or apolipoprotein J is a heterodimeric glycoprotein which is known to be increased during tissue involution in response to hormonal changes or injury and under circumstances leading to apoptosis. Previous studies in wild‐type (WT) and clusterin‐null (Clu−/−) mice indicated a protective role of clusterin over‐expression in astrocytes lasting up to 90 days post‐ischemia. However, in in vitro and in vivo models of neonatal hypoxia‐ischemia, clusterin exacerbates necrotic cell death. We developed recombinant forms of clusterin and examined their effect on propidium iodide uptake, neuronal and synaptic markers as well as electrophysiological recordings in hippocampal slice cultures from Clu−/− and WT mice subjected to oxygen‐glucose deprivation (OGD). WT mice displayed a marked up‐regulation of clusterin associated with electrophysiological deficits and dramatic increase of propidium iodide uptake 5 days post‐OGD. Immunocytochemical and western blot analyses revealed a substantial decrease of neuronal nuclei and synaptophysin immunoreactivity that predominated in WT mice. These findings contrasted with the relative post‐OGD resistance of Clu−/− mice. The addition of biologically active recombinant forms of human clusterin for 24 h post‐OGD led to the abolishment of the ischemic tolerance in Clu−/− slices. This deleterious effect of clusterin was reverted by the concomitant administration of the NMDA receptor antagonist, d‐2‐amino‐5‐phosphonopentanoate. The present data indicate that in an in vitro model of ischemia characterized by the predominance of NMDA‐mediated cell death, clusterin exerts a negative effect on the structural integrity and functionality of hippocampal neurons.
Why Risk Is Not Variance: An Expository Note
Authors: Cox, Jr Louis Anthony (Tony)
Published: June 2008

Variance (or standard deviation) of return is widely used as a measure of risk in financial investment risk analysis applications, where mean‐variance analysis is applied to calculate efficient frontiers and undominated portfolios. Why, then, do health, safety, and environmental (HS&E) and reliability engineering risk analysts insist on defining risk more flexibly, as being determined by probabilities and consequences, rather than simply by variances? This note suggests an answer by providing a simple proof that mean‐variance decision making violates the principle that a rational decisionmaker should prefer higher to lower probabilities of receiving a fixed gain, all else being equal. Indeed, simply hypothesizing a continuous increasing indifference curve for mean‐variance combinations at the origin is enough to imply that a decisionmaker must find unacceptable some prospects that offer a positive probability of gain and zero probability of loss. Unlike some previous analyses of limitations of variance as a risk metric, this expository note uses only simple mathematics and does not require the additional framework of von Neumann Morgenstern utility theory.
Epistemic Uncertainty in the Ranking and Categorization of Probabilistic Safety Assessment Model Elements: Issues and Findings
Authors: Borgonovo Emanuele
Published: June 2008

In this work, we study the effect of epistemic uncertainty in the ranking and categorization of elements of probabilistic safety assessment (PSA) models. We show that, while in a deterministic setting a PSA element belongs to a given category univocally, in the presence of epistemic uncertainty, a PSA element belongs to a given category only with a certain probability. We propose an approach to estimate these probabilities, showing that their knowledge allows to appreciate “the sensitivity of component categorizations to uncertainties in the parameter values” (U.S. NRC Regulatory Guide 1.174). We investigate the meaning and utilization of an assignment method based on the expected value of importance measures. We discuss the problem of evaluating changes in quality assurance, maintenance activities prioritization, etc. in the presence of epistemic uncertainty. We show that the inclusion of epistemic uncertainly in the evaluation makes it necessary to evaluate changes through their effect on PSA model parameters. We propose a categorization of parameters based on the Fussell‐Vesely and differential importance (DIM) measures. In addition, issues in the calculation of the expected value of the joint importance measure are present when evaluating changes affecting groups of components. We illustrate that the problem can be solved using DIM. A numerical application to a case study concludes the work.
Andersen‐Tawil Syndrome: Management Challenges During Pregnancy, Labor, and Delivery
Authors: SUBBIAH RAJESH N. , GULA LORNE J. , SKANES ALLAN C. , KRAHN ANDREW D.
Published: June 2008

Andersen‐Tawil syndrome (ATS) is characterized by ventricular arrhythmias, hypokalemic periodic paralysis and developmental anomalies. It is caused by mutations in the KCNJ2 gene that encodes for the α‐subunit of Kir2.1, a K+ channel responsible for cardiac repolarization. Providing effective therapy to reduce arrhythmia burden and risk of sudden death is challenging, especially in the context of pregnancy and childbirth. We report a case of a pregnant 27‐year‐old woman with an R218W mutation in the C‐terminal interaction domain of KCNJ2 causing ATS. Regular cardiac and obstetric assessments were performed for the duration of the pregnancy, which carried to term and delivered successfully with potassium replacement and intravenous beta blockade. ATS is a rare and potentially lethal condition in which there is considerable genetic and phenotypic heterogeneity. Effective management strategies are directed at reducing symptoms, arrhythmia burden and sudden cardiac death. This case illustrates the challenges and approach to management of patients with ATS who are pregnant and undergo childbirth.
Diagnostic Accuracy of a New Software for Complex Fractionated Electrograms Identification in Patients with Persistent and Permanent Atrial Fibrillation
Authors: CALÒ LEONARDO , DE RUVO ERMENEGILDO , SCIARRA LUIGI , GRICIA ROBERTO , NAVONE GIOVANNA , DE LUCA LUCIA , NUCCIO FRANCESCA , SETTE ANTONELLA , PRISTIPINO CRISTIAN , DULIO ALESSANDRO , GAITA FIORENZO , LIOY ERNESTO
Published: June 2008

Introduction:
The elimination of complex fractionated atrial electrograms (CFAEs) has been proposed as a potential target for guiding successful AF substrate ablation. The possibility to efficiently map the atria and rapidly identify CFAEs sites is necessary, before the CFAEs ablation becomes a routine approach. The aims of this study, conducted in patients with persistent and permanent atrial fibrillation (AF), were to analyze by CARTO mapping in the right (RA) and in the left atrium (LA) during AF: (1) the diagnostic accuracy of a new software for CFAEs analysis, (2) the spatial distribution of CFAEs, (3) the regional beat to beat AF intervals (FF).

Methods and Results:
Twenty‐five consecutive patients (four women, 58.8 ± 11.4 years) undergoing radiofrequency catheter ablation for persistent and permanent AF were enrolled in the study. The CFAE software showed a high sensitivity (90%) and specificity (91%) in the identification of CFAEs, using a specific setting of parameters. The LA had a significantly higher prevalence of CFAEs as compared with the RA (30.5% vs 20.3%, P = 0.016). The CFAEs were mostly present in the septum and in the area of coronary sinus ostium (CS os). The FF intervals were significantly shorter in the LA than in the RA (P < 0.01).

Conclusion:
CARTO system has a high diagnostic accuracy in the identification of CFAEs. Atrial electrical activity (CFAEs, mean FF intervals) during AF showed a significant spatial inhomogeneity.
Perovskite‐Type Strontium Zirconate as a New Material for Thermal Barrier Coatings
Authors: Ma Wen , Mack Daniel E. , Vaßen Robert , Stöver Detlev
Published: June 2008

Perovskite‐type SrZrO3 was investigated as an alternative to yttria‐stabilized zirconia (YSZ) material for thermal barrier coating (TBC) applications. Three phase transformations (orthorhombic↔pseudo‐tetragonal↔tetragonal↔cubic) were found only by heat capacity measurement, whereas the phase transformation from orthorhombic to pseudo‐tetragonal was found in thermal expansion measurements. The thermal expansion coefficients (TECs) of SrZrO3 coatings were at least 4.5% larger than YSZ coatings up to 1200°C. Mechanical properties (Young's modulus, hardness, and fracture toughness) of dense SrZrO3 showed lower Young's modulus, hardness, and comparable fracture toughness with respect to YSZ. The “steady‐state” sintering rate of a SrZrO3 coating at 1200°C was 1.04 × 10−9 s−1, which was less than half that of YSZ coating at 1200°C. Plasma‐sprayed coatings were produced and characterized. Thermal cycling with a gas burner showed that at operating temperatures ∼1250°C the cycling lifetime of SrZrO3/YSZ double‐layer coating (DLC) was more than twice as long as SrZrO3 coating and comparable to YSZ coating. However, at operating temperatures >1300°C, the cycling lifetime of SrZrO3/YSZ DLC was comparable to the optimized YSZ coating, indicating SrZrO3 might be a promising material for TBC applications at higher temperatures compared with YSZ.
Cell Dimensions and Composition of Nanocrystalline Calcium Silicate Hydrate Solid Solutions. Part 1: Synchrotron‐Based X‐Ray Diffraction
Authors: Garbev Krassimir , Beuchle Günter , Bornefeld Marc , Black Leon , Stemmermann Peter
Published: June 2008

Synchrotron‐based X‐ray diffraction has been used to analyze a series of mechanochemically prepared calcium silicate hydrate (C–S–H) phases with aimed Ca/Si ratios from 1/5 to 3/2. Fumed silica and CaO were used as starting materials. All samples contain 3‐dimensionally ordered C–S–H phases. Pure C–S–H phases are present in samples with Ca/Si ratios from 2/3 to 6/5. The samples with C/S ratios 1/5 and 1/2 contain unreacted silica, while those with C/S ratios 4/3 and 3/2 contain portlandite as minor component. A new approach has been used to follow structural changes with C/S ratio, involving assignment of an orthorhombic space group (I2mm) to the C–S–H phase followed by refinement of the unit cell parameters by the whole powder pattern decomposition (WPPD) method. The results reveal a discontinuity in the c parameter at C/S=5/6–1/1, indicating that at least two different structural types separated by a miscibility gap are needed to describe C–S–H, there being two ordered end members with C/S ratios of 2/3 and 5/4, respectively. Nevertheless the structure of C–S–H phases within this interval may be well described by the defect‐tobermorite model. At C/S=2/3 it consists of tobermorite slabs linked via H‐bonds without interlayer Ca. At this C/S ratio, the layer thickness is 13.2 Å. Increasing the C/S ratio leads to little change in the layer thickness, but increased disorder due to competitive omission of bridging tetrahedra and incorporation of Ca in the interlayer in samples with 2/3<C/S<1. For C/S ratios above 1/1, there is an increased structural ordering accompanied by a reduction in layer thickness, which reaches a theoretical minimum at C/S=5/4. This end member has structural features of a tobermorite‐based dimer: {Ca4H2[Si2O7]2}·Ca·mH2O with a layer thickness of 11.7 Å. Its powder pattern fits the B11b space group. Indexing according I2mm sub cell and B11b true cell are also presented.
Reduction of Eu3+ to Eu2+ in Aluminoborosilicate Glasses Prepared in Air
Authors: Liu Shimin , Zhao Gaoling , Ruan Wangle , Yao Zhiwang , Xie Tingting , Jin Ji , Ying Hao , Wang Jianxun , Han Gaorong
Published: June 2008

Eu2O3‐doped aluminoborosilicate glasses were prepared in air at high temperature. Luminescence measurements were used to investigate a valence change from Eu3+ to Eu2+ ions in the aluminoborosilicate glasses. The results showed that the doped Eu3+ ions were partially reduced to Eu2+ in the Eu2O3:RO–Al2O3–B2O3–SiO2 (RO=CaO, SrO, BaO, Li2O) glasses, but not in the Eu2O3:RO–Al2O3–B2O3–SiO2 (RO=Na2O, K2O) glasses. The changes of Eu reduction with different RO components were discussed with the variation of optical basicity of RO and with different valency of R cations. The effects of co‐doping BaO and ZnO in aluminoborosilicate glasses on Eu reduction were also investigated and discussed.
Comparison Between Carbon Nanotube and Carbon Nanofiber Reinforcements in Amorphous Silicon Nitride Coatings
Authors: Kothari Abhishek K. , Jian Kengqing , Rankin Janet , Sheldon Brian W.
Published: June 2008

Amorphous silicon nitride coatings were reinforced with carbon nanotubes and dense carbon nanofibers. These reinforcements were all fabricated with graphene layers oriented parallel to the fiber axis, and some of the nanofibers were also heat‐treated at high temperature to improve graphitic ordering. The effectiveness of these reinforcements as toughening agents was then compared qualitatively by examining the fiber pull out lengths from fracture surfaces. With the dense nanofibers there was almost no evidence of pull‐out, whereas the materials reinforced with multiwalled carbon nanotubes exhibited significant pull‐out. Based on these results, the multiwalled carbon nanotubes appear to provide significantly more toughening than the dense nanofibers.
Sol–Gel Combustion Synthesis of Nanocrystalline YAG Powder from Metal‐Organic Precursors
Authors: Chen Dianying , Jordan Eric H. , Gell Maurice
Published: June 2008

Yttrium aluminum garnet (Y3Al5O12, YAG) nanocrystalline powders were synthesized by a novel sol–gel combustion process. Yttrium acetate and aluminum sec‐butoxide were used as the precursors and triethanolamine was used as the chelating agent and fuel. Thermal and crystallization behaviors of the YAG precursor powders were investigated by thermal gravimetric differential thermal analysis (DTA), Fourier transform infrared spectrum, and X‐ray diffraction. The combustion‐synthesized powders are amorphous and transform to a pure YAG crystalline phase at 900°C. The crystallization activation energy of amorphous YAG precursor was investigated by variable heating rate DTA. The calculated activation energy is 58.9 KJ/mol. The average crystalline size of heat‐treated YAG powders at 900°C is ∼20 nm.