An optical spectrum of the afterglow of a gamma-ray burst at a redshift of z = 6.295.

The prompt gamma-ray emission from gamma-ray bursts (GRBs) should be detectable out to distances of z > 10 (ref. 1), and should therefore provide an excellent probe of the evolution of cosmic star formation, reionization of the intergalactic medium, and the metal enrichment history of the Universe. Hitherto, the highest measured redshift for a GRB has been z = 4.50 (ref. 5). Here we report the optical spectrum of the afterglow of GRB 050904 obtained 3.4 days after the burst; the spectrum shows a clear continuum at the long-wavelength end of the spectrum with a sharp cut-off at around 9,000 A due to Lyman alpha absorption at z approximately 6.3 (with a damping wing). A system of absorption lines of heavy elements at z = 6.295 +/- 0.002 was also detected, yielding the precise measurement of the redshift. The Si ii fine-structure lines suggest a dense, metal-enriched environment around the progenitor of the GRB.

Discovery of the short gamma-ray burst GRB 050709.

Gamma-ray bursts (GRBs) fall into two classes: short-hard and long-soft bursts. The latter are now known to have X-ray and optical afterglows, to occur at cosmological distances in star-forming galaxies, and to be associated with the explosion of massive stars. In contrast, the distance scale, the energy scale and the progenitors of the short bursts have remained a mystery. Here we report the discovery of a short-hard burst whose accurate localization has led to follow-up observations that have identified the X-ray afterglow and (for the first time) the optical afterglow of a short-hard burst; this in turn led to the identification of the host galaxy of the burst as a late-type galaxy at z = 0.16 (ref. 10). These results show that at least some short-hard bursts occur at cosmological distances in the outskirts of galaxies, and are likely to be caused by the merging of compact binaries.

Sequentially addressable dielectrophoretic array for high-throughput sorting of large-volume biological compartments.

Droplet microfluidics has become a powerful tool in precision medicine, green biotechnology, and cell therapy for single-cell analysis and selection by virtue of its ability to effectively confine cells. However, there remains a fundamental trade-off between droplet volume and sorting throughput, limiting the advantages of droplet microfluidics to small droplets (<10 pl) that are incompatible with long-term maintenance and growth of most cells. We present a sequentially addressable dielectrophoretic array (SADA) sorter to overcome this problem. The SADA sorter uses an on-chip array of electrodes activated and deactivated in a sequence synchronized to the speed and position of a passing target droplet to deliver an accumulated dielectrophoretic force and gently pull it in the direction of sorting in a high-speed flow. We use it to demonstrate large-droplet sorting with ~20-fold higher throughputs than conventional techniques and apply it to long-term single-cell analysis of Saccharomyces cerevisiae based on their growth rate.

Prevalence of gastroduodenal mucosal injury in asymptomatic patients taking antiplatelet agents in Japan.

PURPOSE: There is little knowledge regarding the prevalence of mucosal injury (MI) in Japanese patients receiving antiplatelet therapy. This study estimated the prevalence of gastroduodenal MI in asymptomatic Japanese patients taking antiplatelet agents and nonsteroidal anti-inflammatory drugs (NSAIDs). METHODS: Among patients who underwent an upper gastrointestinal endoscopy at Teikyo University Hospital (Tokyo, Japan), 382 asymptomatic patients taking either low-dose aspirin, ticlopidine, cilostazol, or other NSAIDs and 119 people not taking any of these agents were included. Endoscopic records were evaluated for the presence of MI. RESULTS: Aspirin and NSAIDs users showed a higher prevalence of MI than controls (Aspirin, OR = 2.6 (95% CI = 1.4 - 4.9), NSAIDs, 2.9 (1.4 - 4.4)). Concomitant use of aspirin and NSAIDs increased the prevalence of MI (11.2 (2.8 - 44.8)). Ticlopidine and cilostazol were less likely to cause injury than aspirin and other NSAIDs, the difference remained insignificant due to small sample number (ticlopidine, 0.8 (0.2 - 4.0), cilostazol, 1.3 (0.3 - 4.8)). CONCLUSIONS: In asymptomatic Japanese patients receiving low-dose aspirin, the prevalence of the gastroduodenal MI was the same as that in patients taking NSAIDs and higher than that in controls.

Degradation of PEP-19, a calmodulin-binding protein, by calpain is implicated in neuronal cell death induced by intracellular Ca2+ overload.

Excessive elevation of intracellular Ca2+ levels and, subsequently, hyperactivation of Ca2+/calmodulin-dependent processes might play an important role in the pathologic events following cerebral ischemia. PEP-19 is a neuronally expressed polypeptide that acts as an endogenous negative regulator of calmodulin by inhibiting the association of calmodulin with enzymes and other proteins. The aims of the present study were to investigate the effect of PEP-19 overexpression on cell death triggered by Ca2+ overload and how the polypeptide levels are affected by glutamate-induced excitotoxicity and cerebral ischemia. Expression of PEP-19 in HEK293T cells suppressed calmodulin-dependent signaling and protected against cell death elicited by Ca2+ ionophore. Likewise, primary cortical neurons overexpressing PEP-19 became resistant to glutamate-induced cell death. In immunoprecipitation assay, wild type PEP-19 associated with calmodulin, whereas mutated PEP-19, which contains mutations within the calmodulin binding site of PEP-19, failed to associate with calmodulin. We found that the mutation abrogates both the ability to suppress calmodulin-dependent signaling and to protect cells from death. Additionally, the endogenous PEP-19 levels in neurons were significantly reduced following glutamate exposure, this reduction precedes neuronal cell death and can be blocked by treatment with calpain inhibitors. These data suggest that PEP-19 is a substrate for calpain, and that the decreased PEP-19 levels result from its degradation by calpain. A similar reduction of PEP-19 also occurred in the hippocampus of gerbils subjected to transient global ischemia. In contrast to the reduction in PEP-19, no changes in calmodulin occurred following excitotoxicity, suggesting the loss of negative regulation of calmodulin by PEP-19. Taken together, these results provide evidence that PEP-19 overexpression enhances resistance to Ca2+-mediated cytotoxicity, which might be mediated through calmodulin inhibition, and also raises the possibility that PEP-19 degradation by calpain might produce an aberrant activation of calmodulin functions, which in turn causes neuronal cell death.

A computer-controlled contracture correction device with low-load and continuous torque: an animal experiment and prototype design for clinical use.

The purpose of this study was to clarify the relationship between mechanical stress and tissue response of the contracted knee joint in rats and to propose a new design of contracture correction device for clinical use. Wistar rats were operated on to immobilize their knee joints with a procedure causing periarticular bleeding and were kept in flexed position for 40 days. At day 40, the immobilizing wire was removed, and after day 43, the contracted knee joint had been treated with tunable corrective devices secured by an external fixation method to the rear limb. These devices consisted of four types of motor-driving system which provided several different low-load and continuous stretch torques. Measuring the angle of maximum knee extension, its effectiveness was assessed comparing with a lower load and control group of natural recovery course. The device also had a cyclic joint movement within the acquired range of motion and an oval cam mechanism producing a small distraction force to the joint along its long axis. The results showed that an appropriate range of low-load continuous torque was more effective to correct joint contracture. On the basis of the animal experiment, a new computer-controlled, gas-driven contracture correction device was developed for clinical trial. It was concluded that mechanical application in a condition with low and continuous torque is a useful treatment for fixed joint contracture.

[Usefulness of the thoracoscopic surgery under local anesthesia and irrigation for the patient with Bacillus cereus empyema; report of a case].

The case was 54-year-old male with some risks such as chronic heart failure, atrial fibrillation, and liver chirrhosis. He was admitted because of severe back pain and diagnosed as empyema by preoperative thoracentesis. By thoracoscopic procedures under local anesthesia, fibrinopurulent tissues were cleaned as much as possible and 3 of chest tubes were replaced. The final diagnosis was Bacillus cereus pyothorax by bacterial cultures of pleural effusion. Intrathoracic cavity was cleaned with physiological saline solution. The patient made favorable progress and recovered. Thoracoscopic surgery under local anesthesia with thoracic irrigation was so effective and safe methods to control the infection.

Beta-amyloid induces neuronal apoptosis via a mechanism that involves the c-Jun N-terminal kinase pathway and the induction of Fas ligand.

Elevated levels of beta-Amyloid (Abeta) are present in the brains of individuals with either the sporadic or familial form of Alzheimer's disease (AD), and the deposition of Abeta within the senile plaques that are a hallmark of AD is thought to be a primary cause of the cognitive dysfunction that occurs in AD. Recent evidence suggests that Abeta induces neuronal apoptosis in the brain and in primary neuronal cultures, and that this Abeta-induced neuronal death may be responsible in part for the cognitive decline found in AD patients. In this study we have characterized one mechanism by which Abeta induces neuronal death. We found that in cortical neurons exposed to Abeta, activated c-Jun N-terminal kinase (JNK) is required for the phosphorylation and activation of the c-Jun transcription factor, which in turn stimulates the transcription of several key target genes, including the death inducer Fas ligand. The binding of Fas ligand to its receptor Fas then induces a cascade of events that lead to caspase activation and ultimately cell death. By analyzing the effects of mutations in each of the components of the JNK-c-Jun-Fas ligand-Fas pathway, we demonstrate that this pathway plays a critical role in mediating Abeta-induced death of cultured neurons. These findings raise the possibility that the JNK pathway may also contribute to Abeta-dependent death in AD patients.

Paradoxical adaptation of mature radius to unilateral use in tennis playing.

The positive effects of physical activity on human bone mass have been well documented in many cross-sectional studies comparing athletes with sedentary controls as well as in longitudinal follow-up. By applying peripheral quantitative computed tomography (pQCT), which has the advantage of measuring volumetric bone mineral density (BMD) and the ability to distinguish among trabecular and cortical components, it was demonstrated that cortical BMD of the dominant arm was not greater than that of the nondominant arm. Cortical drift toward the periosteal direction and an increase in cortical thickness resulted in an improvement of mechanical characteristics of the playing arm's midradius. An improvement in the mechanical properties of young adult bone in response to long-term exercise was therefore related to geometric adaptation, but not to an increase in BMD. The manner in which the recruitment and function of bone cells are coordinated differs between the growing and the nongrowing skeleton. In the former, modeling is the dominant mode, and in the latter it is remodeling. In the present study, the side-to-side difference of 92 middle-aged female tennis players who initiated training after bone had matured was analyzed by pQCT. The side-to-side difference detected suggested a paradoxical adaptation of the mature radius to unilateral use during tennis playing, and that tennis playing after bone had matured did not stimulate cortical drift in the periosteal direction, unlike that seen in young subjects. Unexpectedly, the cross-sectional areas (periosteal and endocortical area) of the radius were smaller in the dominant arm than in the nondominant arm in the middle-aged female players. The findings suggest that unilateral use of the arm after the third decade of life suppresses age-related changes in bone geometry.

Hemodynamic effects on aortic enzyme activities in spontaneously hypertensive rats.

Spontaneously hypertensive rats (SHRSP and SHR) and normotensive WKR were treated with hypotensive drugs, and arterial and venous enzyme activities were compared between treated and nontreated hypertensive groups. With the 4 month experiment, cholesterol esterase activity in the aorta from hypertensive SHRSP and SHR was significantly lower than that in the respective treated groups, whereas venous activity did not differ. By contrast, aortic NAGA activity was significantly higher in the hypertensive groups without any changes in venous activity. Acid phosphatase activity was unaltered. No effects of treatment were observed in the normotensive WKR. Accompanying a decrease in aortic cholesterol esterase, there was a marked increase in aortic cholesteryl esters accompanying hypertension. Aortic phosphodiesterase activity was significantly elevated in the hypertensive SHRSP and SHR compared with the respective treated groups. These results suggest that hypertension of long duration specifically decreased aortic cholesterol esterase activity with a consequent accumulation of cholesteryl esters in the aorta, and that this hemodynamic effect seemed to be partly mediated by cyclic AMP with an effect on the lysosomal membrane. These results could provide the biochemical bases for the relationship between hypertension and atherosclerosis.

Aortic cholesterol esterase and other lysosomal enzyme activities in DOCA-salt, renal and spontaneous hypertension in the rat.

In spontaneously hypertensive rats, prolonged hypertension caused a decrease in aortic cholesterol esterase activity with N-acetyl-beta-D-glucosaminidase activity increased and acid phosphatase activity unchanged [3]. The present study was undertaken to compare these changes with those caused by other experimentally induced types of hypertension. Treatment with DOCA-salt for one month significantly elevated both aortic cholesterol esterase and acid phosphatase activities. In contrast, to spontaneous hypertension, venous changes were also observed. An intake of 1% NaCl ad libitum produced results similar to those with the DOCA-salt treatment, despite the fact that blood pressure did not increase. This suggested that humoral factors were the main cause of the elevated enzyme activities in DOCA-salt hypertension. In rats made hypertensive by unilateral renal arterial constriction with contralateral nephrectomy (one clip--one kidney hypertension) or without contralateral nephrectomy (one clip--two kidney hypertension), aortic cholesterol esterase activities were unchanged, while aortic N-acetyl-beta-D-glucosaminidase, and aortic and venous acid phosphatase activities were increased. These results show distinct differences in the response of lysosomal enzymes during the three hypertensive states.

The neuroprotective effect of a novel calmodulin antagonist, 3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate, in transient forebrain ischemia.

A novel calmodulin (CaM) antagonist DY-9760e, (3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate), with an apparent neuroprotective effect in vivo, potently inhibits CaM-dependent nitric oxide synthase in situ. In the present study, we determined whether DY-9760e inhibits nitric oxide (NO) production and protein nitration by peroxynitrite (ONOO(-)) formation in the hippocampal CA1 region of gerbils after transient forebrain ischemia. In freely moving gerbils, NO production after 10-minute forebrain ischemia was monitored consecutively with in vivo brain microdialysis. Pretreatment with DY-9760e (50 mg/kg i.p.) significantly decreased the increased levels of NO(x)(-) (NO metabolites, NO(2)(-) plus NO(3)(-)) immediately after, 24 h after cerebral ischemia-reperfusion to the control levels of sham-operated animals. Western blot and immunohistochemical analyses using an anti-nitrotyrosine antibody as a marker of ONOO(-) formation indicated a marked increase in nitrotyrosine immunoreactivity in the pyramidal neurons of the CA1 region 2 h after reperfusion, and DY-9760e significantly inhibited increased nitrotyrosine immunoreactivity. Coincident with the inhibition of the NO production and protein tyrosine nitration, pretreatment with DY-9760e rescued the delayed neuronal death in the hippocampal CA1 region. These results suggest that the inhibitory effects of DY-9760e on the NO-ONOO(-) pathway partly account for its neuroprotective effects in cerebral ischemia.

Inhibition of neuronal nitric oxide synthase activity by 3-[2-[4-(3-chloro-2-methylphenyl)- 1-piperazinyl]ethyl]-5, 6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate (DY-9760e), a novel neuroprotective agent, in vitro and in cultured neuroblastoma cells in situ.

DY-9760e, 3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5, 6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate, a novel calmodulin (CaM) antagonist, possesses neuroprotective activity. In the current study, we examined the effects of DY-9760e on nitric oxide synthase (NOS) activities in vitro and on calcium ionophore-induced NO production in situ. DY-9760e inhibited both neuronal NOS and endothelial NOS activities without affecting inducible NOS activity. It also inhibited purified neuronal NOS activity with a potency similar to that seen for purified CaM kinase II activity in vitro. Furthermore, DY-9760e significantly inhibited Ca(2+) ionophore (A23187)-induced NO production in mouse N1E-115 neuroblastoma cells, at a concentration of less than 1 microM. In contrast, no apparent inhibitory effect on Ca(2+)/CaM-dependent protein kinase II activity was observed in cultured hippocampal neurons up to 5 microM. These results suggest that the inhibitory effect of DY-9760e on CaM-dependent NOS activities underlies neuroprotective effects of the agent.

Protein kinase C subspecies in hippocampus and striatum of reserpinized rat brain.

Protein kinase C (PKC) (alpha) and (beta) immunoreactivities were determined in the cytosolic and particulate fractions of the hippocampus and striatum after single and repetitive, intraperitoneal administration of reserpine. Significant decrease of PKC(alpha) immunoreactivities was observed in the particulate fractions of both striatum and hippocampus. Compared with the alteration of PKC(alpha), the decreased immunoreactivity of PKC(beta) was only observed in the particulate fraction of the hippocampus, associated with the increase in the cytosolic fraction. These findings suggest a novel mechanism regulating the distribution of PKC. The topographical selectivity in the present study may indicate the importance of the alteration of PKC(beta) in the pathophysiological mechanism in Alzheimer's disease.

Endothelium removal augments vasodilation by sodium nitroprusside and sodium nitrite.

Sodium nitroprusside (3-100 nM) and sodium nitrite (0.03-1 mM) caused relaxation of the rat aortic ring segments precontracted by norepinephrine. The relaxation was significantly augmented by removal of endothelium, and this augmentation was greater in the aorta from spontaneously hypertensive rats (SHR) than Wistar Kyoto rats (WKY). The mechanism remains unknown but such augmentation may be clinically favorable to the use of nitrovasodilators.

DY-9760e, a novel calmodulin antagonist, reduces brain damage induced by transient focal cerebral ischemia.

Perturbations in Ca2+ homeostasis have been proposed to lead to neuronal damage after cerebral ischemia. DY-9760e (3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1- (4-imidazolylethyl)-1H-indazole dihydrochloride 3.5 hydrate) is a novel calmodulin antagonist. In this study, we examined the effects of DY-9760e on brain damage in rats subjected to transient (1 h) focal cerebral ischemia. DY-9760e (0.25-1.00 mg kg(-1) h(-1)) was intravenously infused for 6 h, starting 1 h after middle cerebral artery occlusion. Treatment with DY-9760e 0.25, 0.50 and 1.00 mg kg(-1) h(-1) reduced infarct volume by 30, 42 (P < 0.05), and 60% (P < 0.05), respectively. Furthermore, the effect of DY-9760e on ischemia-induced fodrin breakdown was examined in the same model. Pronounced fodrin breakdown was observed in the cerebral cortex and striatum at 24 h after ischemia. DY-9760e caused potent suppression of fodrin breakdown in the cerebral cortex at the same doses as those that had a protective action against cerebral infarction. From these results DY-9760e may have a therapeutic effect against cerebral ischemic damage in the acute stage.

DY-9760e, a novel calmodulin antagonist with cytoprotective action.

We report the pharmacological characterization and cytoprotective effect of DY-9760e, 3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-( 4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate, a novel antagonist of calmodulin. DY-9760e inhibited calmodulin-dependent enzymes, including calmodulin-dependent protein kinase II and IV, calcineurin, [corrected] calmodulin-dependent phosphodiesterase and myosin light chain kinase with Ki values of 1.4, 12, 2.0, 3.8 and 133 microM, respectively. These antagonistic effects of DY-9760e were more potent than those of W-7, N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide, another calmodulin antagonist. This compound showed little or no effect on calmodulin-independent enzymes, such as protein kinase A and C and calpain I and II. Analysis of the hydrophobic interaction of DY-9760e with calmodulin by using 2-p-toluidinylnaphthalene-6-sulfonate and 9-anthroylcholine revealed that, like W-7, DY-9760e bound to the hydrophobic regions of calmodulin. The [14C]DY-9760e binding assay indicated that DY-9760e bound to calmodulin at one class of binding site. Finally, DY-9760e substantially protected N1E-115 neuroblastoma cells from cytotoxicity induced by the Ca2+ ionophore, A23187. These results indicate that DY-9760e, a novel calmodulin antagonist, possesses a cytoprotective action and suggest that calmodulin plays a critical role in mediating some of the biochemical events leading to cell death following Ca2+ overload.

Reduced membrane-associated protein kinase C(beta) immunoreactivity in the hippocampus of reserpinized rat brain.

Protein kinase C(beta) immunoreactivity was determined in the membrane and cytosol fractions of the hippocampus, frontal cortex and cerebellum after repetitive, intraperitoneal administration of reserpine. A marked decrease in the immunoreactivity was observed in the membrane of the hippocampus, while no significant change was found in any other subfractions of the frontal cortex or cerebellum. These findings suggest a novel mechanism regulating the distribution of protein kinase C. The topographical selectivity in the present study may indicate the importance of the alteration of protein kinase C in the pathophysiological mechanism in Alzheimer's disease.

Post-ischemic administration of DY-9760e, a novel calmodulin antagonist, reduced infarct volume in the permanent focal ischemia model of spontaneously hypertensive rat.

We assessed the effect of a novel calmodulin antagonist, DY-9760e (3-[2-[4-(3-chloro-2-methylphenyl)-1-piperazinyl]ethyl]-5,6-dimethoxy-1-(4-imidazolylmethyl)-1H-indazole dihydrochloride 3.5 hydrate) in a spontaneously hypertensive rat (SHR) permanent focal cerebral ischemia. In experiment I, the left middle cerebral artery was permanently occluded in 62 SHRs. DY-9760e (0.5 mg kg(-1) h(-1)) or vehicle alone were administered continuously i.v. for 6 h, beginning 0, 30, or 60 min after the arterial occlusion. The infarct volume was measured 24 h of ischemia. In experiment II, the effect of DY-9760e on CBF was assessed in 10 SHRs. Administration without a delay resulted in a mean infarct volume of 166.7 +/- 21.0 mm3 (vehicle; n = 10) and 125.1 +/- 31.8 mm3 (DY-9760e; n = 9). Administration with a 30 min delay resulted in a mean infarct volume of 173.2 +/- 32.4 mm3 (vehicle; n = 12) and 143.3 +/- 35.3 mm3 (DY-9760e; n = 11). Dy-9760e significantly reduced the infarct under these conditions (p < 0.05). The administration with a 60 min delay failed to reduce the infarct. DY-9760e had no effect on the CBF. Continuous i.v. administration of DY-9760e reduced infarct volume in a SHR permanent focal ischemia without affecting ischemic CBF.

C1-C2 intra-articular screw fixation for atlantoaxial posterior stabilization.

STUDY DESIGN: A trial of a new posterior stabilization technique for atlantoaxial instability and a report of preliminary results. OBJECTIVES: To describe a new posterior stabilization technique for atlantoxial instability. SUMMARY OF BACKGROUND DATA: Magerl's transarticular screw fixation is an accepted technique for rigid atlantoaxial stabilization, which reportedly has yielded many good clinical results. However, the technique is technically demanding and poses a risk of injury to the nerves and veins. METHODS: Eleven patients who had been treated with intra-articular screw fixation in combination with Halifax interlaminar clamp (OSTEONICS, Allendale, NJ) for atlantoaxial instability were observed. Results of their clinical examinations and biomechanical studies using resinous bones of a cervical spine model were reviewed. RESULTS: In all patients, occipital pain, neck pain, and neural deficit improved, and bony fusion with no correction loss was shown on radiography. To date, no vascular or neural complications have been found, and no instrumentation failures have occurred. In the biomechanical study, the Halifax with transarticular screw fixation had significantly greater flexion stiffness than the Halifax only or the Halifax with intra-articular screw fixation, but the torsion stiffness of the Halifax with intra-articular screw fixation was significantly greater than that of the other Halifax combinations. CONCLUSION: The preliminary results showed that this technique was effective in strengthening the rotational stability of the atlantoaxial fixation and was considered useful for atlantoaxial posterior stabilization.