ABSTRACT
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.
Subject(s)
Microfluidics , Saccharomyces cerevisiae , Electrodes , Microfluidics/methodsABSTRACT
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.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Duodenitis/epidemiology , Gastritis/epidemiology , Gastrointestinal Hemorrhage/epidemiology , Platelet Aggregation Inhibitors/adverse effects , Aged , Duodenitis/chemically induced , Female , Gastritis/chemically induced , Gastrointestinal Hemorrhage/chemically induced , Helicobacter Infections/blood , Helicobacter Infections/epidemiology , Humans , Japan , Male , Middle Aged , PrevalenceABSTRACT
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.
Subject(s)
Calcium/toxicity , Calmodulin-Binding Proteins/metabolism , Calpain/metabolism , Neurons/physiology , Peptides/metabolism , Animals , Blotting, Western , Calmodulin/antagonists & inhibitors , Cell Death/drug effects , Cell Death/physiology , Cell Line , Cerebral Cortex/cytology , Cerebral Cortex/drug effects , Cerebral Cortex/physiology , Cysteine Endopeptidases/metabolism , Excitatory Amino Acid Agonists/toxicity , Female , Gerbillinae , Glutamic Acid/toxicity , Humans , Neurons/drug effects , Neuroprotective Agents/pharmacology , Peptides/genetics , Plasmids/genetics , Pregnancy , Rats , Reverse Transcriptase Polymerase Chain Reaction , TransfectionABSTRACT
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.
Subject(s)
Anesthesia, Local , Bacillus cereus , Empyema, Pleural/surgery , Gram-Positive Bacterial Infections , Thoracoscopy , Anti-Bacterial Agents/therapeutic use , Cardiomyopathy, Dilated/complications , Clarithromycin/therapeutic use , Empyema, Pleural/microbiology , Humans , Liver Cirrhosis/complications , Male , Middle Aged , Therapeutic Irrigation , Thoracic CavityABSTRACT
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.
Subject(s)
Contracture/therapy , Equipment Design , Knee Joint , Therapy, Computer-Assisted/instrumentation , Animals , Contracture/physiopathology , Disease Models, Animal , Male , Range of Motion, Articular , Rats , Rats, Wistar , Torque , Weight-BearingABSTRACT
Tension is necessary to maintain and restore the mechanical properties of soft connective tissues. Conversely, reduced tension states such as produced by immobilization weaken mechanical properties and facilitate joint contracture. We assessed the effect of low torque-long duration stretching to increase the range of motion (ROM) and to restore the mechanical properties of contracted joints in 66 rat knees immobilized for 40 days. After remobilization, we randomly divided the contracted knees into four treatment groups treated with repeated stretches of diverse torques and duration: stretching with low-torque and long-duration, high-torque and short-duration, high-torque and long-duration, low-torque and short duration. We included control and natural recovery groups. Phase lag in all treatment groups recovered to the same range as in the normal controls. Dynamic stiffness, which was not altered by joint immobilization, increased in all treatment groups. Deformation and load to failure improved substantially only in the low-torque and long-duration stretching group. Low-torque and long-duration repeated stretching leads to a greater restoration of ROM with more normal mechanical properties compared to high-torque and short duration stretching.
Subject(s)
Contracture/therapy , Animals , Male , Physical Therapy Modalities , Range of Motion, Articular , Rats , Rats, Wistar , Time Factors , TorqueABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
Subject(s)
Brain Ischemia/prevention & control , Calmodulin/antagonists & inhibitors , Hippocampus/drug effects , Indazoles/therapeutic use , Ischemic Attack, Transient/pathology , Neuroprotective Agents/therapeutic use , Tyrosine/analogs & derivatives , Animals , Blotting, Western , Carotid Artery, Internal, Dissection , Chromatography, High Pressure Liquid , Disease Models, Animal , Enzyme Inhibitors/administration & dosage , Gerbillinae , Hippocampus/metabolism , Immunohistochemistry , Male , Microdialysis , NG-Nitroarginine Methyl Ester/administration & dosage , Nitric Oxide/metabolism , Reperfusion/methods , Time Factors , Tyrosine/metabolismABSTRACT
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.
Subject(s)
Adaptation, Physiological/physiology , Radius/physiology , Tennis/physiology , Adult , Bone Density , Female , Humans , Middle Aged , Radius/diagnostic imaging , Tomography, X-Ray ComputedABSTRACT
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.
Subject(s)
Alzheimer Disease/metabolism , Amyloid beta-Peptides/pharmacology , Apoptosis , Membrane Glycoproteins/metabolism , Mitogen-Activated Protein Kinases/metabolism , Neurons/drug effects , Alzheimer Disease/etiology , Animals , Apoptosis/genetics , Cells, Cultured , Enzyme Activation/drug effects , Fas Ligand Protein , Gene Expression Regulation , JNK Mitogen-Activated Protein Kinases , Membrane Glycoproteins/genetics , Mice , Mice, Inbred Strains , Mice, Knockout , Mitogen-Activated Protein Kinase 10 , Mitogen-Activated Protein Kinases/deficiency , Mitogen-Activated Protein Kinases/genetics , Neurons/metabolism , Neurons/pathology , Phosphorylation/drug effects , Protein-Tyrosine Kinases/deficiency , Protein-Tyrosine Kinases/genetics , Proto-Oncogene Proteins c-jun/metabolism , Rats , Rats, Long-Evans , Signal Transduction/drug effects , Transcription, Genetic/drug effects , fas Receptor/metabolismABSTRACT
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.
Subject(s)
Brain Infarction/drug therapy , Brain Ischemia/drug therapy , Calcium/metabolism , Calmodulin/antagonists & inhibitors , Indazoles/pharmacology , Nerve Degeneration/drug therapy , Neuroprotective Agents/pharmacology , Animals , Brain Infarction/metabolism , Brain Infarction/physiopathology , Brain Ischemia/metabolism , Brain Ischemia/physiopathology , Calmodulin/metabolism , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Cerebral Cortex/physiopathology , Cerebrovascular Circulation/drug effects , Cerebrovascular Circulation/physiology , Disease Models, Animal , Glutamic Acid/metabolism , Male , Neostriatum/drug effects , Neostriatum/metabolism , Neostriatum/physiopathology , Nerve Degeneration/physiopathology , Nerve Degeneration/prevention & control , Rats , Rats, Inbred SHRABSTRACT
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.
Subject(s)
Enzyme Inhibitors/pharmacology , Indazoles/pharmacology , Neurons/drug effects , Neuroprotective Agents/pharmacology , Nitric Oxide Synthase/antagonists & inhibitors , Analysis of Variance , Animals , Calcium-Calmodulin-Dependent Protein Kinase Type 2 , Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors , Calmodulin/antagonists & inhibitors , Cell Extracts/analysis , Hippocampus/drug effects , Hippocampus/enzymology , Neuroblastoma , Neurons/enzymology , Nitric Oxide/metabolism , Nitric Oxide Synthase Type I , Nitric Oxide Synthase Type II , Nitric Oxide Synthase Type III , Rats , Sulfonamides/pharmacology , Tumor Cells, CulturedABSTRACT
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.
Subject(s)
Atlanto-Axial Joint/surgery , Bone Screws , Joint Instability/surgery , Adult , Aged , Atlanto-Axial Joint/diagnostic imaging , Biomechanical Phenomena , Cervical Vertebrae , Female , Humans , Joint Dislocations/surgery , Male , Methods , Middle Aged , Postoperative Care , Radiography , RotationABSTRACT
We compared the safety and efficacy of transurethral resection of the prostate (TURP) with a thick loop and with a standard loop. We compared 36 consecutive men (median age, 70 years) with symptomatic benign prostatic hyperlasia (BPH) treated by TURP with a thick loop to a cohort of 36 men (median age, 72 years) treated by TURP with a standard loop. The safety parameters of evaluation included the operative time, blood loss, chronological changes in serum sodium, and complications. The efficacy parameters of evaluation included International Prostate Symptom Score, quality of life assessment, peak urinary flow rate, and post-void residual urine volume. The operative time (median, 49.5 versus 43.5 minutes), blood loss (median, 179 versus 127 ml), and change in serum sodium (median, -4.0 versus -6.0 mEq/L) were not significantly greater in the thick loop group than in the standard loop group, respectively. There were no major complications in either group. Clinically significant improvement was observed in all efficacy parameters in both groups, with no difference between the two groups. These results suggest that TURP with a thick loop is not necessarily superior to TURP with a standard loop in terms of decreasing the blood loss and decreasing the operative time.
Subject(s)
Prostatectomy/methods , Prostatic Hyperplasia/surgery , Aged , Aged, 80 and over , Blood Loss, Surgical , Blood Volume , Humans , Male , Middle Aged , Sodium/blood , Time FactorsABSTRACT
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.
Subject(s)
Brain Ischemia/drug therapy , Calmodulin/antagonists & inhibitors , Carrier Proteins/metabolism , Indazoles/therapeutic use , Microfilament Proteins/metabolism , Nerve Tissue Proteins/metabolism , Animals , Blood Pressure/drug effects , Brain Ischemia/metabolism , Cerebral Arteries/drug effects , Cerebral Cortex/drug effects , Cerebral Cortex/metabolism , Cerebral Cortex/pathology , Constriction, Pathologic , Corpus Striatum/drug effects , Corpus Striatum/metabolism , Corpus Striatum/pathology , Indazoles/pharmacology , Infusions, Intravenous , Male , Rats , Rats, WistarABSTRACT
BACKGROUND AND OBJECTIVE: The purpose of this study was to compare the effect of Low-Level Laser Therapy (LLLT) with sham and whirlpool treatment on the contracted knee joint in rat. STUDY DESIGN/MATERIALS AND METHODS: Forty-eight Wistar rats were operated on to immobilize knee joint, and 1 week after operation they were randomly assigned to four treatment groups: laser 40 mW (3.9 W/cm2), laser 60 mW (5.8 W/cm2), whirlpool (42 degrees C), and sham laser. Tunable Ga-Al-As semiconductor (810 nm) laser was used for another 2 weeks of treatment. Removing and preparing bilateral hind legs, degree of knee contracture was assessed by measuring the knee flexion angle, weight of the gastrocnemius muscle, and periarticular connective tissue viscoelasticity measuring phase-lag and stiffness. RESULTS AND CONCLUSION: Laser irradiation showed no significant changes except the phase-lag of laser 60 mW. Under the conditions of this study, LLLT stimulation did not provide a significant effect for minimizing the degree of experimental joint contracture over whirlpool treatment.
Subject(s)
Contracture/therapy , Hydrotherapy , Joints , Laser Therapy , Animals , Contracture/physiopathology , Contracture/radiotherapy , Hindlimb , Joints/physiopathology , Joints/radiation effects , Male , Rats , Rats, WistarABSTRACT
The purpose of this investigation was to compare the dynamic viscoelastic properties of various models composed of denture teeth and heat-cured denture base resin. The specimens were porcelain and resin teeth mounted in denture base resin. Compressive dynamic stiffness and phase differences were measured with a viscoelastic spectrometer. Measurements of the viscoelastic frequency spectrum based on the fast Fourier transform of displacement to applied random forces were analyzed with a spectrum analyzer. The stiffness of the specimens was independent of the frequency. The stiffness of the porcelain specimens was higher than that of the resin ones measured under the same conditions. The phase lag of the specimens was dependent on the frequency. The phase lag of the porcelain specimens was lower than that of the resin ones measured under the same conditions. This study suggested that the acrylic resin teeth had greater toughness and higher shock-absorbing ability than the porcelain teeth, and that the porcelain teeth were more brittle than the acrylic resin ones, whether the teeth were isolated or in dentures.
Subject(s)
Tooth, Artificial , Acrylic Resins/chemistry , Bicuspid , Dental Porcelain/chemistry , Dental Stress Analysis , Denture Bases , Elasticity , Fourier Analysis , Humans , Materials Testing , Spectrum Analysis , ViscosityABSTRACT
Only a few plate systems are available for anterior fixation of thoracolumbar vertebrae because of the difficulty in fastening a screw and a plate together. If the fixation is inadequate, the screws will become loose. The Rigix plate system consists of screws made of titanium alloy and a plate made of pure titanium. All screws used for internal fixation are screwed into the plate. This system permits the use of anchor screws, which facilitate exertion of force to compress the vertebral bodies together or to distract them from each other. In this study, Rigix plates were used in 24 patients (20 with burst fractures and 4 with metastatic tumors). In the 20 patients with fracture, internal fixation with a graft and a Rigix plate was performed after anterior decompression. In the four patients with malignant tumors, total spondylectomy was performed anteriorly and posteriorly, followed by implantation of a vertebral prosthesis, and then internal fixation with a Rigix plate combined posterior instrumentation with Diapson (Stryker Co., Tokyo, Japan) pedicular screws. Bone union was achieved in all patients. Neither breakage of instruments nor loosening of connections occurred in any case. In patients treated for bone metastases, the reconstructed spinal structure was able to be maintained for a long period. Of the screws used, five (5%) were not able to remain fixed as intended because they were inserted at inappropriate angles into the plate, but the fixation itself was excellent. Because of the low profile, ease of manipulation (mean instrumentation time was 25 min), and compatibility with magnetic resonance imaging, the Rigix plate is useful for anterior fixation of thoracolumbar vertebrae.
Subject(s)
Bone Plates , Fracture Fixation, Internal/instrumentation , Lumbar Vertebrae/injuries , Lumbar Vertebrae/surgery , Spinal Fractures/surgery , Thoracic Vertebrae/injuries , Thoracic Vertebrae/surgery , Adult , Aged , Biomechanical Phenomena , Bone Screws , Equipment Design , Female , Humans , Magnetic Resonance Imaging , Male , Materials Testing , Middle Aged , Radiography , Spinal Fractures/diagnosis , Spinal Fractures/diagnostic imagingABSTRACT
OBJECTIVE: To examine whether electrical stimulation could decrease the degree of joint stiffness in a rat lower extremity model. DESIGN: Rat knee joints were surgically immobilized in a flexed position for 3 weeks. Two groups of rats were stimulated with 20 microA and 50 microA constant direct current. Another group had surgical intervention and sham electrodes without electricity. The hind leg was extirpated and prepared for a sample with the femur-knee joint-tibia unit. Recording the knee flexion angle with extension torque, the degree of joint contracture was assessed biomechanically by measuring the bone-joint-bone sample as a cantilever. Measurement was performed with (1) spectral analysis of transfer function measurement using random mechanical noise with frequency range from 1 to 50Hz, and (2) dynamic stiffness and loss tangent with steady-state sinusoidal excitation (11 and 35Hz). RESULTS: The results showed that no significant difference or trend was found in vibration analysis among three groups. However, spectral analysis of transfer function measurement revealed more deformation against load, and more viscous nature in the stimulation groups, especially in low frequency band, than in the sham group. CONCLUSION: Electrical stimulation with constant direct current has a possibility of reducing the degree of joint contracture.