bluuebunny/crossref_metadata_2025 huggingface dataset:
COSMOLOGICAL QUINTESSENCE ACCRETION ONTO PRIMORDIAL BLACK HOLES: CONDITIONS FOR THEIR GROWTH TO THE SUPERMASSIVE SCALE
Authors: CUSTÓDIO P. S. , HORVATH J. E.
Published: June 2005

In this work we revisit the growth of small primordial black holes (PBHs) immersed in a quintessential field and/or radiation to the supermassive black hole (SMBHs) scale. We show the difficulties of scenarios in which such huge growth is possible. For that purpose we evaluated analytical solutions of the differential equations (describing mass evolution) and point out the strong fine tuning for the conclusions. The timescale for growth in a model with a constant quintessence flux is calculated and we show that it is much bigger than the Hubble time. The fractional gain of the mass is further evaluated in other forms, including quintessence and/or radiation. We calculate the cosmological density Ω due to quintessence necessary to grow BHs to the supermassive range and show it to be much bigger than one. We also describe the set of complete equations analyzing the evolution of the BH + quintessence universe, showing some interesting effects such the quenching of the BH mass growth due to the evolution of the background energy. Additional constraints obtained by using the Holographic Bound are also described. The general equilibrium conditions for evaporating/accreting black holes evolving in a quintessence/radiation universe are discussed in Appendix.
COSMOLOGY WITH MIRROR DARK MATTER I: LINEAR EVOLUTION OF PERTURBATIONS
Authors: CIARCELLUTI PAOLO
Published: June 2005

This is the first paper of a series devoted to the study of the cosmological implications of the parallel mirror world with the same microphysics as the ordinary one, but having smaller temperature, with a limit set by the BBN constraints. The difference in temperature of the ordinary and mirror sectors generates shifts in the key epochs for structure formation, which proceeds in the mirror sector under different conditions. We consider adiabatic scalar primordial perturbations as an input and analyze the trends of all the relevant scales for structure formation (Jeans length and mass, Silk scale, horizon scale) for both ordinary and mirror sectors, comparing them with the CDM case. These scales are functions of the fundamental parameters of the theory (the temperature of the mirror plasma and the amount of mirror baryonic matter), and in particular they are influenced by the difference between the cosmological key epochs in the two sectors. Then we use a numerical code to compute the evolution in linear regime of density perturbations for all the components of a Mirror Universe: ordinary baryons and photons, mirror baryons and photons, and possibly cold dark matter. We analyze the evolution of the perturbations for different values of mirror temperature and baryonic density, and obtain that for x=T′/T less than a typical value x eq , for which the mirror baryon–photon decoupling happens before the matter–radiation equality, mirror baryons are equivalent to the CDM for the linear structure formation process. Indeed, the smaller the value of x, the closer mirror dark matter resembles standard cold dark matter during the linear regime.
COSMOLOGY WITH MIRROR DARK MATTER II: COSMIC MICROWAVE BACKGROUND AND LARGE SCALE STRUCTURE
Authors: CIARCELLUTI PAOLO
Published: June 2005

This is the second paper of a series devoted to the study of the cosmological implications of the existence of mirror dark matter. The parallel hidden mirror world has the same microphysics as the observable one and couples the latter only gravitationally. The primordial nucleosynthesis bounds demand that the mirror sector should have a smaller temperature T′ than the ordinary one T, and by this reason its evolution can be substantially deviated from the standard cosmology. In this paper we take scalar adiabatic perturbations as the input in a flat Universe, and compute the power spectra for ordinary and mirror CMB and LSS, changing the cosmological parameters, and always comparing with the CDM case. We find differences in both the CMB and LSS power spectra, and we demonstrate that the LSS spectrum is particularly sensitive to the mirror parameters, due to the presence of both the oscillatory features of mirror baryons and the collisional mirror Silk damping. For x<0.3 the mirror baryon–photon decoupling happens before the matter–radiation equality, so that CMB and LSS power spectra in linear regime are equivalent for mirror and CDM cases. For higher x-values the LSS spectra strongly depend on the amount of mirror baryons. Finally, qualitatively comparing with the present observational limits on the CMB and LSS spectra, we show that for x<0.3 the entire dark matter could be made of mirror baryons, while in the case x≳0.3 the pattern of the LSS power spectrum excludes the possibility of dark matter consisting entirely of mirror baryons, but they could present as admixture (up to ~50%) to the conventional CDM.
QSSC RE-EXAMINED FOR THE NEWLY DISCOVERED SNeIa
Authors: VISHWAKARMA R. G. , NARLIKAR J. V.
Published: June 2005

We examine the possible consistency of the quasi-steady state model with the newly discovered SNe Ia . The model assumes the existence of metallic dust ejected from the SNe explosions, which extinguishes light travelling over long distances. We find that the model shows a reasonable fit to the data, which improves if one take account of the weak gravitational lensing effect of the SNe which have been observed on the brighter side.
EXPLOITING AMODAL CUES FOR ROBOT PERCEPTION
Authors: ARSENIO ARTUR M. , FITZPATRICK PAUL M.
Published: June 2005

This paper presents an approach to detecting, segmenting, and recognizing rhythmically moving objects that generate sound as they move. We show selectivity and robustness in the face of distracting motion and sounds. Our method does not require accurate sound localization, and in fact is complementary to it. The work is implemented on the humanoid robot Cog.1 We are motivated by the fact that objects that move rhythmically are common and important for a humanoid robot. The humanoid form is often argued for so that the robot can interact well with tools designed for humans, and such tools are typically used in a repetitive manner, with sound generated by physical abrasion or collision; consider hammers, chisels, saws, etc. We also work with the perception of toys designed for infants — rattles, bells, etc. — which could have utility for entertainment/pet robotics. Our goal is to build the perceptual tools required for a robot to learn to use tools and toys through demonstration.
COLLABORATING WITH HUMANOID ROBOTS IN SPACE
Authors: SOFGE DONALD , BUGAJSKA MAGDALENA , TRAFTON J. GREGORY , PERZANOWSKI DENNIS , THOMAS SCOTT , SKUBIC MARJORIE , BLISARD SAMUEL , CASSIMATIS NICHOLAS , BROCK DEREK , ADAMS WILLIAM , SCHULTZ ALAN
Published: June 2005

One of the great challenges of putting humanoid robots into space is developing cognitive capabilities for the robots with an interface that allows human astronauts to collaborate with the robots as naturally and efficiently as they would with other astronauts. In this joint effort with NASA and the entire Robonaut team, we are integrating natural language and gesture understanding, spatial reasoning incorporating such features as human–robot perspective taking, and cognitive model-based understanding to achieve a high level of human–robot interaction. Building greater autonomy into the robot frees the human operator(s) from focusing strictly on the demands of operating the robot, and instead allows the possibility of actively collaborating with the robot to focus on the task at hand. By using shared representations between the human and robot, and enabling the robot to assume the perspectives of the human, the humanoid robot may become a more effective collaborator with a human astronaut for achieving mission objectives in space.
High-mobility group box 1 protein is an inflammatory mediator in necrotizing enterocolitis: protective effect of the macrophage deactivator semapimod
Authors: Zamora Ruben , Grishin Anatoli , Wong Catarina , Boyle Patricia , Wang Jin , Hackam David , Upperman Jeffrey S. , Tracey Kevin J. , Ford Henri R.
Published: June 2005

High-mobility group box 1 (HMGB1) is a late mediator of endotoxemia known to stimulate the production of proinflammatory cytokines that are putative mediators of intestinal inflammation associated with necrotizing enterocolitis (NEC). We hypothesized that HMGB1 is also involved in the pathogenesis of NEC. We examined the expression of HMGB1 and the effect of the novel drug semapimod on intestinal inflammation in an experimental model of NEC in neonatal rats. Newborn rats were subjected to hypoxia and fed a conventional formula by gavage (FFH) or were breast fed (BF). Rats were killed on day 4, and the distal ileum was harvested for morphological studies and Western blot analysis. FFH newborn rats but not BF controls developed intestinal inflammation similar to the histological changes observed in human NEC. We found that the expression of HMGB1 and its receptor for advanced glycation end products (RAGE) as well as that of other apoptosis/inflammation-related proteins (Bad, Bax, inducible nitric oxide synthase, and cyclooxygenase 2) was upregulated in the ileal mucosa of FFH newborn rats compared with BF animals. Administration of the drug semapimod inhibited the upregulation of those proteins and partially protected the animals against the FFH-induced intestinal injury. Elevated levels of HMGB1 were also found in ileal samples from infants undergoing intestinal resection for acute NEC. Our results implicate HMGB1 and RAGE as important mediators of enterocyte cell death and hypoxia-induced injury in NEC and support the hypothesis that inhibitors such as semapimod might play a therapeutic role in chronic intestinal inflammation characterized by this animal model.
Reduced constrictor reactivity balances impaired vasodilation in the mesenteric circulation of the obese Zucker rat
Authors: Romanko Olga P. , Stepp David W.
Published: June 2005

Obesity causes whole body insulin resistance and impaired vasodilation to nitric oxide (NO). Because NO is a major contributor to the regulation of mesenteric blood flow, the mesenteric circulation of obese animals is faced with reduced capacity to increase flow and increased demand for flow associated with elevated consumption of food. This study hypothesized that insulin resistance impairs NO-mediated dilation but that constrictor reactivity would be reduced to compensate in obese animals. We further hypothesized that elevated superoxide levels caused impaired responses to NO in insulin resistance. Vasodilator reactivity and vasoconstrictor reactivity of mesenteric resistance arteries from lean (LZR) and obese (OZR) Zucker rats were examined in vitro using videomicroscopy. Insulin resistance independent of obesity was induced via fructose feeding in LZR (FF-LZR). Endothelium-dependent NO-mediated dilation was reduced in OZR and FF-LZR compared with LZR. Impairments in NO-mediated dilation were reversed with 1 mM tempol, a SOD mimetic. Constrictor reactivity to norepinephrine was reduced in OZR but not in FF-LZR relative to LZR. Basal mesenteric vascular resistance was similar in LZR and OZR despite impaired NO-dependent dilation in OZR. Mesenteric vascular resistance was increased in FF-LZR relative to LZR. These data indicate that there is reduced constrictor reactivity in OZR that may offset the impaired NO-mediated dilation and preserve mesenteric blood flow in hyperphagic, obese animals.
Mechanism of nicotine-induced pulmonary fibroblast transdifferentiation
Authors: Rehan Virender K. , Wang Ying , Sugano Sharon , Romero Sonia , Chen Xiaoru , Santos Jamie , Khazanchi Aarti , Torday John S.
Published: June 2005

We tested the hypothesis that in vitro nicotine exposure disrupts specific epithelial-mesenchymal paracrine signaling pathways and results in pulmonary interstitial lipofibroblast (LIF)-to-myofibroblast (MYF) transdifferentiation, resulting in altered pulmonary development and function. Studies were done to determine whether nicotine induces LIF-to-MYF transdifferentiation and to elucidate underlying molecular mechanism(s) involved and to determine whether nicotine-induced LIF-to-MYF transdifferentiation could be prevented by stimulating specific alveolar interstitial fibroblast lipogenic pathway. WI38 cells, a human embryonic pulmonary fibroblast cell line, were treated with nicotine with or without specific agonists of alveolar fibroblast lipogenic pathway, PTHrP, DBcAMP, or the potent PPARγ stimulant rosiglitazone (RGZ) for 7 days. Expression of key lipogenic and myogenic markers was examined by RT-PCR, Western hybridization, and immunohistochemistry. The effect of nicotine on triglyceride uptake by WI38 cells and PTHrP binding to its receptor was also determined. Finally, the effect of transfecting WI38 cells with a PPARγ expression vector on nicotine-induced LIF-to-MYF transdifferentiation was determined. Nicotine treatment resulted in significantly decreased expression of lipogenic and increased expression of myogenic markers in a dose-dependent manner, indicating nicotine-induced LIF-to-MYF transdifferentiation. This was accompanied by decreased PTHrP receptor binding to its receptor. The nicotine-induced LIF-to-MYF transdifferentiation was completely prevented by concomitant treatment with PTHrP, DBcAMP, RGZ, and by transiently overexpressing PPARγ. Our data suggest nicotine induces alveolar LIF-to-MYF transdifferentiation through a mechanism involving downregulation of lipogenic PTHrP-mediated, cAMP-dependent PKA signaling pathway, which can be prevented using specific molecular targets. Potential therapeutic implications of these observations against in utero nicotine-induced lung injury remain to be tested.
Clinical assessment of blood leukocytes, serum cytokines, and serum immunoglobulins as responses to sleep deprivation in laboratory rats
Authors: Everson Carol A.
Published: June 2005

The specific systems and mechanisms affected by sleep deprivation that may perpetuate disease processes in humans still are speculative. In laboratory rats, prolonged sleep deprivation induces a state marked by abnormal control over indigenous bacteria that results in transient infections of internal tissues and eventual lethal septicemia. The present studies investigated changes in blood, serum, and bone marrow parameters that may provide diagnostic clues to immunopathology. Prolonged sleep deprivation was produced in rats by the disk-over-water method, a well-established and selective means that does not interfere with normal waking behaviors. Measurements included bone and blood differential white blood cell counts, multiple serum cytokines and chemokines, several major Ig classes and subclasses, and serum endotoxin concentrations. The results indicated mild, regenerative neutrophilia in sleep-deprived rats, initially accompanied by immature neutrophils and later by monocytosis. The corresponding serum cytokine profile revealed an evolving proinflammatory state, particularly by high incidence of interleukin-1β, implicating mononuclear phagocytes and resident tissue cells as main intermediary sources. In addition, multiple serum Ig classes were increased by sleep deprivation without experimental administration of an exogenous antigen. Despite this immune activation, there was failure to eradicate invading bacteria and toxins, suggesting competing anti-inflammatory processes or interference with immune effector functions during sleep deprivation. Nearly all of the immune-related events that emerged as responses to sleep deprivation have been implicated as etiological or provocative factors in other disease processes and may provide means by which sleep deprivation as a risk factor in disease may become understood.
P2X2 and P2X3 receptor expression in postnatal and adult rat urinary bladder and lumbosacral spinal cord
Authors: Studeny Simon , Torabi Ali , Vizzard Margaret A.
Published: June 2005

P2X receptors mediate the effects of ATP in micturition and nociception. During postnatal maturation, a spinobulbospinal reflex and voluntary voiding replace primitive voiding reflexes. This may involve changes in neuroactive compounds and receptors in bladder reflex pathways. We examined P2X2 and P2X3 receptors in bladder and spinal cord from postnatal (P0–P36, indicating number of days) and adult Wistar rats. Western blot of whole bladders for P2X2 and P2X3 expression was performed. Immunostaining for P2X2 and P2X3 receptors in urothelium and detrusor smooth muscle whole mounts and spinal cord sections was examined. Western blot demonstrated an age-dependent decrease ( R2= 0.96, P ≤ 0.005) in P2X2 receptor expression in bladder, whereas P2X3 receptor expression in bladder peaked ( P ≤ 0.005) during P14–P21. P2X2-immunoreactivity (IR) was present in urothelial cells, suburothelial plexus, detrusor smooth muscle, and serosa at birth, with staining in urothelial cells and serosa being most predominant. With increasing postnatal age, the intensity of P2X2-IR decreased in urothelial cells but increased in suburothelial plexus. P2X3-IR increased in urothelial cells and suburothelial plexus with postnatal age, whereas staining in detrusor and serosa remained relatively constant. At birth, P2X3-IR was present in the dorsal horn, lateral collateral pathway, and dorsal commissure. With increasing age, P2X3-IR was restricted to superficial dorsal horn and lateral collateral pathway. P2X2-IR was present in ependyme cells (S-100-IR) of the central canal as early as P2. These studies demonstrate plastic expression of P2X2 and P2X3 receptors in bladder and spinal cord during early postnatal development at times coincident with appearance of mature voiding patterns.
Early antibiotic administration but not antibody therapy directed against IL-6 improves survival in septic mice predicted to die on basis of high IL-6 levels
Authors: Vyas Dinesh , Javadi Pardis , DiPasco Peter J. , Buchman Timothy G. , Hotchkiss Richard S. , Coopersmith Craig M.
Published: June 2005

Elevated interleukin (IL)-6 levels correlate with increased mortality following sepsis. IL-6 levels >14,000 pg/ml drawn 6 h after cecal ligation and puncture (CLP) are associated with 100% mortality in ND4 mice, even if antibiotic therapy is initiated 12 h after septic insult. Our first aim was to see whether earlier institution of antibiotic therapy could improve overall survival in septic mice and rescue the subset of animals predicted to die on the basis of high IL-6 levels. Mice ( n = 184) were subjected to CLP, had IL-6 levels drawn 6 h later, and then were randomized to receive imipenem, a broad spectrum antimicrobial agent, beginning 6 or 12 h postoperatively. Overall 1-wk survival improved from 25.5 to 35.9% with earlier administration of antibiotics ( P < 0.05). In mice with IL-6 levels >14,000 pg/ml, 25% survived if imipenem was started at 6 h, whereas none survived if antibiotics were started later ( P < 0.05). On the basis of these results, we examined whether targeted antibody therapy could improve survival in mice with elevated IL-6 levels. A different cohort of mice ( n = 54) had blood drawn 6 h after CLP, and then they were randomized to receive either monoclonal anti-IL-6 IgG or irrelevant rat IgG. Anti-IL-6 antibody failed to improve either overall survival or outcome in mice with IL-6 levels >14,000 pg/ml. These results demonstrate that earlier systemic therapy can improve outcome in a subset of mice predicted to die in sepsis, but we are unable to demonstrate any benefit in similar animals using targeted therapy directed at IL-6.
Orexin A-induced feeding is augmented by caloric challenge
Authors: Thorpe A. J. , Teske J. A. , Kotz C. M.
Published: June 2005

Orexin neurons are stimulated by conditions that are glucoprivic, suggesting that orexin signaling may be increased during nutritional duress. We have previously shown that injection of orexin A (OxA) into the rostral lateral hypothalamic area (rLHa) robustly and dose-dependently increases feeding behavior. Thus we hypothesized that exogenous administration of orexin A would induce a greater feeding response after acute food deprivation or perceived caloric duress achieved through 2-deoxyglucose (2DG) administration. To test our hypothesis, male Sprague-Dawley rats implanted with internal guide cannulas directed to the rLHa were exposed to varying degrees of food deprivation (0, 3, 12, 24 h) and 2DG (200 mg/kg) before intra-rLHa OxA (500 pmol) infusion. We also performed a dose-response study using graded doses of OxA (0, 31.25, 125, and 500 pmol) in fed and 24-h fasted rats. OxA administration in conjunction with the highest level of prior food deprivation (24 h) resulted in the greatest feeding response (above baseline means; 0 h deprivation: 1.9 ± 0.6; 24 h deprivation: 4.4 ± 0.8; P = 0.0034) and showed a dose-dependent enhancement of feeding. Additionally, 2DG administration before OxA administration resulted in a significantly higher feeding response (above baseline means: 2DG = 1.8 ± 0.5; OxA = 1.8 ± 0.4; 2DG + OxA = 5.1 ± 0.6; P < 0.0001). These data support the hypothesis that orexin signaling may be important in modulating the feeding network under times of nutritional duress.
Renal ischemia induces an increase in nitric oxide levels from tissue stores
Authors: Salom Miguel G. , Arregui Begoña , Carbonell Luis F. , Ruiz Fernando , González-Mora José Luis , Fenoy Francisco J.
Published: June 2005

Tissue nitric oxide (NO) levels increase dramatically during ischemia, an effect that has been shown to be partially independent from NO synthases. Because NO is stored in tissues as S-nitrosothiols and because these compounds could release NO during ischemia, we evaluated the effects of buthionine sulfoximine (BSO; an intracellular glutathione depletor), light stimulation (which releases NO, decomposing S-nitrosothiols), and N-acetyl-l-cysteine (a sulfhydryl group donor that repletes S-nitrosothiols stores) on the changes in outer medullary NO concentration produced during 45 min of renal artery occlusion in anesthetized rats. Renal ischemia increased renal tissue NO concentration (+223%), and this effect was maintained along 45 min of renal arterial blockade. After reperfusion, NO concentration fell below preischemic values and remained stable for the remainder of the experiment. Pretreatment with 10 mg/kg nitro-l-arginine methyl ester (l-NAME) decreased significantly basal NO concentration before ischemia, but it did not modify the rise in NO levels observed during ischemia. In rats pretreated with 4 mmol/kg BSO and l-NAME, ischemia was followed by a transient increase in renal NO concentration that fell to preischemic values 20 min before reperfusion. A similar response was observed when the kidney was illuminated 40 min before the ischemia. The coadministration of 10 mg/kg iv N-acetyl-l-cysteine with BSO + l-NAME restored the increase in NO levels observed during renal ischemia and prevented the depletion of renal thiol groups. These results demonstrate that the increase in renal NO concentration observed during ischemia originates from thiol-dependent tissue stores.
Epithelial Ca2+channel expression and Ca2+uptake in developing zebrafish
Authors: Pan Tien-Chien , Liao Bo-Kai , Huang Chang-Jen , Lin Li-Yih , Hwang Pung-Pung
Published: June 2005

The purpose of the present work was to study the possible role of the epithelial Ca2+channel (ECaC) in the Ca2+uptake mechanism in developing zebrafish ( Danio rerio). With rapid amplification of cDNA ends, full-length cDNA encoding the ECaC of zebrafish (zECaC) was cloned and sequenced. The cloned zECaC was 2,578 bp in length and encoded a protein of 709 amino acids that showed up to 73% identity with previously described vertebrate ECaCs. The zECaC was found to be expressed in all tissues examined and began to be expressed in the skin covering the yolk sac of embryos at 24 h postfertilization (hpf). zECaC-expressing cells expanded to cover the skin of the entire yolk sac after embryonic development and began to occur in the gill filaments at 96 hpf, and thereafter zECaC-expressing cells rapidly increased in both gills and yolk sac skin. Corresponding to ECaC expression profile, the Ca2+influx and content began to increase at 36–72 hpf. Incubating zebrafish embryos in low-Ca2+(0.02 mM) freshwater caused upregulation of the whole body Ca2+influx and zECaC expression in both gills and skin. Colocalization of zECaC mRNA and the Na+-K+-ATPase α-subunit (a marker for mitochondria-rich cells) indicated that only a portion of the mitochondria-rich cells expressed zECaC mRNA. These results suggest that the zECaC plays a key role in Ca2+absorption in developing zebrafish.
DNA damage and osmotic regulation in the kidney
Authors: Dmitrieva Natalia I. , Burg Maurice B. , Ferraris Joan D.
Published: June 2005

Renal medullary cells normally are exposed to extraordinarily high interstitial NaCl concentration as part of the urinary concentrating mechanism, yet they survive and function. Acute elevation of NaCl to a moderate level causes transient cell cycle arrest in culture. Higher levels of NaCl, within the range found in the inner medulla, cause apoptosis. Recently, it was surprising to discover that even moderately high levels of NaCl cause DNA double-strand breaks. The DNA breaks persist in cultured cells that are proliferating rapidly after adaptation to high NaCl, and DNA breaks normally are present in the renal inner medulla in vivo. High NaCl inhibits repair of broken DNA both in culture and in vivo, but the DNA is rapidly repaired if the level of NaCl is reduced. The inhibition of DNA repair is associated with suppressed activity of some DNA damage-response proteins like Mre11, Chk1, and H2AX but not that of others, like GADD45, p53, ataxia telangiectasia-mutated kinase (ATM), and Ku86. In this review, we consider possible mechanisms by which the renal cells escape the known dangerous consequences of persistent DNA damage. Furthermore, we consider that the persistent DNA damage may be a sensor of hypertonicity that activates ATM kinase to provide a signal that contributes to protective osmotic regulation.
Functional specificity of Sgk1 and Akt1 on ENaC activity
Authors: Arteaga Maria Francisca , Canessa Cecilia M.
Published: June 2005

Reabsorption of sodium by the epithelial sodium channel (ENaC) is essential for maintaining the volume of the extracellular compartment and blood pressure. The function of ENaC is regulated primarily by aldosterone, antidiuretic hormone [arginine vasopressin (AVP)], and insulin, but the molecular mechanisms that increase channel activity are still poorly understood. It has been proposed that the related serine/threonine kinases serum- and glucocorticoid-induced kinase (Sgk1) and protein kinase B (Akt) mediate activation of ENaC. Here, we addressed the question of whether there is functional specificity of these kinases for the activation of ENaC in epithelial cells of the distal renal tubule. We demonstrate that Akt does not increase ENaC function under basal conditions or after stimulation with aldosterone, insulin, or AVP. In contrast, under the same experimental conditions, Sgk1 increases ENaC activity by 10-fold. The effect of Sgk1 is additive to that of aldosterone, whereas, in the presence of active Sgk1, cells do not further respond to insulin or AVP. We conclude that, in cells expressing both kinases, modulation of ENaC activity is mediated by Sgk1 but not by Akt1.
Age-related differences in corticospinal control during functional isometric contractions in left and right hands
Authors: Sale Martin V. , Semmler John G.
Published: June 2005

The purpose of the study was to examine age-related differences in electromyographic (EMG) responses to transcranial magnetic stimulation (TMS) during functional isometric contractions in left and right hands. EMG responses were recorded from the first dorsal interosseus muscle following TMS in 10 young (26.6 ± 1.3 yr) and 10 old (67.6 ± 2.3 yr) right-handed subjects. Muscle evoked potentials (MEPs) and silent-period durations were obtained in the left and right hands during index finger abduction, a precision grip, a power grip, and a scissor grip, while EMG was held constant at 5% of maximum. For all tasks, MEP area was 30% ( P < 0.001) lower in the left hand of old compared with young subjects, whereas there was no age difference in the right hand. The duration of the EMG silent period was 14% ( P < 0.001) shorter in old (150.3 ± 2.9 ms) compared with young (173.9 ± 3.0 ms) subjects, and the age differences were accentuated in the left hand (19% shorter, P < 0.001). For all subjects, the largest MEP area (10–12% larger) and longest EMG silent period (8–19 ms longer) were observed for the scissor grip compared with the other three tasks, and the largest task-dependent change in these variables was observed in the right hand of older adults. These differences in corticospinal control in the left and right hands of older adults may reflect neural adaptations that occur throughout a lifetime of preferential hand use for skilled (dominant) and unskilled (nondominant) motor tasks.
Changes in lipoprotein lipase modulate tissue energy supply during stress
Authors: Ricart-Jané David , Cejudo-Martín Pilar , Peinado-Onsurbe Julia , López-Tejero M. Dolores , Llobera Miquel
Published: June 2005

We studied the variations caused by stress in lipoprotein lipase (LPL) activity, LPL-mRNA, and local blood flow in LPL-rich tissues in the rat. Stress was produced by body immobilization (Immo): the rat's limbs were taped to metal mounts, and its head was placed in a plastic tube. Chronic stress (2 h daily of Immo) decreased total LPL activity in mesenteric and epididymal white adipose tissue (WAT) and was accompanied by a weight reduction of these tissues. In limb muscle, heart, and adrenals, total LPL activity and mRNA levels increased, and, in plasma, LPL activity and mass also increased. Acute stress (30-min Immo) caused a decrease in total LPL activity only in retroperitoneal WAT and an increase in preheparin plasma active LPL, but the overall weight of this tissue did not vary significantly. We propose an early release of the enzyme from this tissue into the bloodstream by some unknown extracellular pathways or other local mechanisms. These changes in this key energy-regulating enzyme are probably induced by catecholamines. They modify the flow of energy substrates between tissues, switching the WAT from importer to exporter of free fatty acids and favoring the uptake by muscle of circulating triacylglycerides for energy supply. Moreover, we found that acute stress almost doubled blood flow in all WAT studied, favoring the export of free fatty acids.
Alternatives to Debriefing and Modifications to Cognitive Behavior Therapy for Posttraumatic Stress Disorder
Authors: Belaise Carlotta , Fava Giovanni A. , Marks Isaac M.
Published: June 2005

Background: Psychological debriefing uses brief unsystematic exposure, and is ineffective for posttraumatic stress symptoms and disorder. Systematic exposure alone and cognitive restructuring alone are each effective. Other approaches too may be useful. Methods: The treatment of 3 posttraumatic stress disorder (PTSD) patients is detailed in which there was no exposure to the main traumatic event.There was exposure to related cues in case 1, exposure to related and other cues followed by well-being therapy (WBT) in case 2 and WBT in case 3. Results: The 3 patients improved enduringly, confirming earlier findings that exposure to the main trauma is not essential for PTSD to improve. Conclusions: A study is needed of therapeutic mechanisms in PTSD and of the value of WBT in a randomized controlled trial.
Increased Recognition of Depression in Primary Care
Authors: Berardi Domenico , Menchetti Marco , Cevenini Nadia , Scaini Sara , Versari Matteo , de Ronchi Diana
Published: June 2005

Background: Underrecognition and undertreatment of depression in primary care has been regarded as a major public health problem. In contrast, some studies found that among patients labeled as depressed by primary-care physicians (PCPs), a relevant proportion do not satisfy international diagnostic criteria for depression. The aims of this study are: (1) to assess disparity between PCP diagnosis and research diagnosis of depression; (2) to compare antidepressant treatment in concordant and discordant cases of depression. Methods: Data are gathered from a national survey on depressive disorders in primary care, conducted with the collaboration of 191 PCPs. Three hundred and sixty-one PCP patients were evaluated, and their psychiatric diagnosis was established by the ‘unaided’ PCPs and by using a research interview for depression. Results: PCPs recognized 79.4% of cases of depression and prescribed antidepressants to 40.9% of them. Yet, 45.0% of patients labeled as depressed by the PCPs were not cases of depression according to ICD-10 criteria; 26.9% of false-positive cases received an antidepressant. Globally, 35% of antidepressants for ‘depression’ were prescribed to false-positive cases. Conclusions: Underrecognition and undertreatment of depression in primary care seem to be less alarming. Conversely, PCP diagnoses of depression appear to be more inclusive than psychiatric diagnostic criteria. A possible consequence of this apparently more inclusive diagnostic threshold may be an excessive use of antidepressants. These changes require a corresponding change in research, toward efficacy and safety of the treatment of milder cases, and in education, toward the distinction between the management of mild and severe cases of depression.
Alexithymia and Interpersonal Problems
Authors: Spitzer Carsten , Siebel-Jürges Ute , Barnow Sven , Grabe Hans Joergen , Freyberger Harald J.
Published: June 2005

Background: Interpersonal relationships are substantially codetermined by nonverbal communication, e.g. facial affect. Given the deficits of nonverbal affect recognition and expression in alexithymia, we hypothesized that alexithymics had more interpersonal problems than nonalexithymic individuals, and that the various facets of the alexithymia construct are differentially related to interpersonal problems. Method: 149 subjects participating in an inpatient group psychotherapy program completed the Toronto Alexithymia Scale (TAS-20) and the Inventory of Interpersonal Problems (IIP-C) at the beginning of the treatment. The IIP-C was also administered to a subgroup at the end of the treatment. Results: Based on the alexithymia scores, patients were classified as low- (TAS-20 score ≤51), moderate- or high-alexithymic (TAS-20 score ≧61). High-alexithymic patients had significantly more interpersonal problems than low alexithymics, particularly in the IIP-C scales indicating hostility and social avoidance. The TAS-20 subscale difficulty describing feelings showed the highest correlations with interpersonal problems (r between 0.23 and 0.55). At the end of the treatment, the high alexithymics still scored highest on the IIP-C, but the magnitude of change in interpersonal problems did not differ across the groups. Conclusions: Our findings suggest that the interpersonal style of alexithymic individuals is characterized by a cold and socially avoidant behavior, corresponding to the predominantly insecure attachment pattern found in alexithymia. Additionally, our results indicate that group psychotherapy is as helpful for alexithymic as for nonalexithymic subjects with respect to interpersonal problems. Finally, we propose that alexithymia involves a reduced capacity to use social interactions for affect regulation.
An Evaluation of the ‘Coping with Depression Course’ for Relapse Prevention with Unipolar Depressed Patients
Authors: Kuehner Christine
Published: June 2005

Background: Patients with treated episodes of depression are at high risk of relapse and recurrence. This study describes the clinical course of patients who had received cognitive-behavioral group intervention for relapse prevention. Method: Forty-four remitted unipolar depressed patients with recently treated episodes of illness participated in a 16-week group program, the ‘Coping with Depression Course’ (CWD). The majority of patients had suffered from multiple episodes of depression and nearly half of them were only partially remitted when they started the program. Assessments took place throughout the intervention and 17–23 months after the pretest. Descriptive analyses included proportions of reliable and clinically significant improvements, and cumulative relapse rates were estimated using survival analysis. Results: At posttest, residual depression and dysfunctional attitudes had significantly decreased. Improvements were similar in patients with and those without parallel antidepressant medication. Two thirds of patients starting within a dysfunctional depression range showed a clinically significant improvement at the end of the intervention. The estimated cumulative relapse rates at 6, 12, 17, and 23 months after pretest were 13.6, 30.0, 37.0 and 44.9%. Conclusions: Participants appeared to be protected from relapse during active intervention, but a substantial proportion suffered relapses in the postintervention period. Further research into the CWD is needed within the framework of randomized controlled trials.
Simulation in Perimetry – Program Perisim 2000
Authors: Fankhauser Franz , Kwasniewska Sylwia , Weale Robert
Published: June 2005

The program Perisim 2000 enables one to simulate the interaction of a number of visual field examination strategies with a number of stored visual fields, both normal and pathological, with several patterns of observer (patient) behavior. A considerable number of visual fields, patient behavior patterns and examination strategies, including a full bracketing strategy, Gonzalez de la Rosa’s tendency-oriented perimetry (TOP) and Weber’s dynamic program, are available. Statistical programs are also incorporated. While the examination strategies to be used in the simulations must be selected from a predefined list, new visual field and observer patterns may be defined by the user. The results may be shown as numerical tables, symbolic or gray tone, pseudocolor or profile displays. Cumulative defect curves may also be selected. The learning/teaching benefits of the program Perisim 2000 are considerable. It is easy to understand and to operate, and ample explanations are available at each step of the program.
Electrolytes and Electrophoretic Studies of Tear Proteins in Tears of Patients with Nasolacrimal Duct Obstruction
Authors: Lew Helen , Yun Young-Soo , Lee Sang-Yeul
Published: June 2005

This study was performed to determine whether there are differences in tear constituents between normal persons and patients with primary acquired nasolacrimal duct obstruction (PANDO) and to correlate differences in tear composition with the degree of PANDO. We tested 30 normal persons (mean age 42.0 ± 21.4 years) and 34 PANDO patients (mean age 44.8 ± 17.9 years) consisting of 18 cases with complete obstruction and 16 cases with partial obstruction. We measured the pH, the concentration of Na+, K+, Cl–, total calcium and total protein of the tears. The composition of tear protein was assessed by cellulose acetate electrophoresis. The data were analyzed by a t test. The pH was more alkaline in patients with PANDO (7.11 ± 0.38), especially in cases with complete obstruction (7.14 ± 0.30, p = 0.47) compared with the normal persons (6.94 ± 0.35). The concentration of Na+, K+, Cl– and total protein were similar in normal and PANDO cases, while total calcium concentration was significantly higher in PANDO (2.62 ± 1.70 mg/dl) compared with the normal cases (1.73 ± 0.97 mg/dl), (p = 0.015). This change was found in both cases with complete obstruction (2.47 ± 1.25 mg/dl, p = 0.027) and cases with partial obstruction (3.00 ± 2.16 mg/dl, p = 0.009). PANDO patients had lower levels of tear protein fraction (TPF) 1 (p = 0.006) and higher levels of tear TPF 4 (p = 0.000) than normal persons. Tears in PANDO cases were more alkaline, higher in calcium concentration, and unstable in the proportion of tear proteins compared with normal persons. These results may improve our understanding of tear physiology and the pathogenesis of PANDO.
Comparison of the Proliferation and Differentiation Ability between Adult Rat Retinal Stem Cells and Cerebral Cortex-Derived Neural Stem Cells
Authors: Liu I-Hsien , Chen Shih-Jen , Ku Hung-Hai , Kao Chung-Lan , Tsai Fu-Ting , Hsu Wen-Ming , Lo Chih-Wen , Kuo Yao-Haur , Kuo Cheng-Deng , Lee Chen-hsen , Chiou Shih-Hwa
Published: June 2005

Recent studies have demonstrated that retinal stem cells (RSCs) and stem cells of the central nervous system both exhibited the abilities of self-renewal, proliferation and differentiation into multilineage. In the present study, we compared the proliferation and differentiation abilities between RSCs and cerebral corticex-derived neural stem cells (CNSCs) of adult rats. Stem cells isolated from pigmented ciliary margins of eyes and cerebral cortical tissues of adult rats were cultured in 96-well plates that contained serum-free medium with epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF). In contrast to RSCs, which stopped proliferating after the 8th week, the total cell count of neurospheres in CNSCs increased twofold at the 5th week and more than fourfold at the 10th week after in vitro culture. In contrast, RSCs stopped proliferating after 8 weeks of culture. After adding 2% fetal calf serum and withdrawing EGF and bFGF from the culture medium, the percentages of nestin-positive cells(20.6 ± 2.7%), microtubule-associated-protein-2-positive neurons (33.2 ± 3.9%) and glial-fibrillary-acidic-protein-positive glial cells(51.3 ± 6.2%) in the differentiated CNSCs were significantly higher than those in the differentiated RSCs (10.2 ± 1.9, 22.3 ± 1.3 and 44.6 ± 5.1%, respectively; p < 0.05). We also found that the combination of transforming growth factor β type III with retinoic acid played an important role in the induction of CNSCs to differentiate into opsin-positive cells. Our data demonstrated that CNSCs displayed a higher ability of proliferation and retinal lineage. This report also offers an alternative protocol of cell reproduction for producing retinal cells.
Orbital Spread of Conjunctival Squamous Cell Carcinoma following Evisceration: A Reminder of the Importance of Thorough Evaluation before and after Destructive Surgery
Authors: Sharma Vidushi , Betharia Subhash M. , Pushker Neelam , Kashyap Seema , Sen Seema
Published: June 2005

Evisceration is a neglected surgery usually performed by the most junior ophthalmologists in unsalvageable eyes with panophthalmitis. It is universal knowledge that evisceration is contraindicated in eyes with intraocular malignancy. We report 2 patients who presented to us with squamous cell carcinoma (SCC) in eviscerated sockets. While one of them was diagnosed with SCC on histopathological examination of the eviscerated contents, the other had history suggestive of conjunctival SCC prior to evisceration. The second patient presented to us with complaints of poorly fitting prostheses. We conclude that it is imperative to rule out not just intraocular but also adnexal malignancy prior to evisceration, and these eyes should be regularly followed up and carefully examined if poor fitting of the prostheses develops.
Unilateral Exophthalmos Associated with Severe Fibrous Dysplasia
Authors: Kuhli Claudia , Lüchtenberg Marc , Weidauer Stefan , Ohrloff Christian
Published: June 2005

Fibrous dysplasia is a benign developmental anomaly of bone, often affecting craniofacial bones. We report on a 9-year-old boy, who presented for routine checkup. Clinical examination revealed unilateral exophthalmos of his left eye without decrease of visual acuity or double vision. Radiologic studies showed characteristic extensive changes of fibrous dysplasia involving the left frontal bone, left orbital bones, maxillary and sphenoid bones. The patient was started on conservative therapy and the condition of the affected eye remained stable. As fibrous dysplasia of the orbital bones can be a cause of significant dysfunction and a treatable cause of blindness, early diagnosis is very important. These patients are most likely to present with complaints of facial asymmetry, including axial, vertical, or horizontal displacement of the globe, or visual loss. Therefore the ophthalmologist plays an important role in the early diagnosis of fibrous dysplasia.
Perioperative Posterior Ischemic Optic Neuropathy as a Rare Complication of Blepharoplasty
Authors: Kordic H. , Flammer J. , Mironow A. , Killer H.E.
Published: June 2005

Purpose: To report a case of visual loss to light perception in the right eye after upper and lower eyelid blepharoplasty. Design: Case report. Method: A 46-year-old man was referred 3 days after combined bilateral upper and lower lid blepharoplasty with visual acuity of light perception in the right eye. The fundus examination, fluorescein angiography and magnetic resonance imaging of the orbit were normal. Ocular motility was full in all directions of gaze. Result: The diagnosis of optic nerve damage was initially based on the relative afferent pupillary defect. The diagnosis of a perioperative posterior ischemic optic neuropathy was based on the Goldmann visual field examination and the subsequent optic atrophy. Central visual acuity, color vision as well as the visual field improved markedly within 3 months. Conclusion: Blindness is a rare but feared complication of blepharoplasty and is reported to occur in about 0.04% of cases. Although intraorbital hemorrhage is thought to be the leading cause for optic nerve damage in most of the patients with this devastating condition, we present a case with perioperative posterior ischemic optic neuropathy leading to visual loss after blepharoplasty. The mechanism leading to optic nerve damage in this patient may include compromised small arteries perfusing the optic disk due to direct mechanical compression and a probable vasoconstrictive activity of the anesthetic agent.
Epidemiological Survey of Epilepsy in the Primary School Population in Buenos Aires
Authors: Somoza Manuel J. , Forlenza Raúl H. , Brussino Marta , Licciardi Liliana
Published: June 2005

Background: Most studies carried out in Latin America have shown greater rates of epilepsy and generalized seizures than those observed in developed countries, in spite of lower numbers of patients receiving treatment. To date, studies in Argentina have been insufficient to establish true prevalence. Objective: To determine the prevalence of epilepsy in primary school children in Buenos Aires, together with rates of different seizure types, treatments prescribed, diagnoses made and number of inadequate therapies administered, as well as the relationship between epilepsy and learning difficulties. Design and Method: A cross-sectional study was carried out on 10% of the entire primary school population of Buenos Aires through randomized, systematic, representative and conglomerate sampling of public and private school students. A total of 26,270 responses were received (83.1% of the population) to a specially designed questionnaire, with 96.4% sensitivity and 41.5% specificity, respectively. Interviews were conducted in all probable epilepsy cases as well as in a random sample of probable negative ones. Results: Eighty-four children with epilepsy were detected (lifetime prevalence 3.2‰; active prevalence 2.6‰), in whom generalized seizures predominated (57.1%). Ninety-three percent of cases diagnosed were currently under, or had previously received antiepileptic drug (AED) therapy. Almost 1% of the primary school population studied had a prior diagnosis and/or received AED for dysrhythmia or epilepsy. The percentage of grade repeaters in the general population and in children with epilepsy was 8.4 and 26.2%, respectively. Conclusions: (1) The prevalence of epilepsy in primary school children in Buenos Aires is similar to that reported for developed countries; (2) a slight prevalence for generalized seizures was observed; (3) 93% of cases received AEDs; (4) misdiagnoses and unnecessary treatments exceeded correct diagnoses and adequate therapy, and (5) disease presence and/or treatment were associated with poorer school performance.