Time-dependent cell-state selection identifies transiently expressed genes regulating ILC2 activation

The decision of whether cells are activated or not is controlled through dynamic intracellular molecular networks. However, the low population of cells during the transition state of activation renders the analysis of the transcriptome of this state technically challenging. To address this issue, we have developed the Time-Dependent Cell-State Selection (TDCSS) technique, which employs live-cell imaging of secretion activity to detect an index of the transition state, followed by the simultaneous recovery of indexed cells for subsequent transcriptome analysis. In this study, we used the TDCSS technique to investigate the transition state of group 2 innate lymphoid cells (ILC2s) activation, which is indexed by the onset of interleukin (IL)-13 secretion. The TDCSS approach allowed us to identify time-dependent genes, including transiently induced genes (TIGs). Our findings of IL4 and MIR155HG as TIGs have shown a regulatory function in ILC2s activation.

Annexin A1 is a cell-intrinsic metalloregulator of zinc in human ILC2s

Group 2 innate lymphoid cells (ILC2s) produce large amounts of type 2 cytokines including interleukin-5 (IL-5) and IL-13 in response to various stimuli, causing allergic and eosinophilic diseases. However, the cell-intrinsic regulatory mechanisms of human ILC2s remain unclear. Here, we analyze human ILC2s derived from different tissues and pathological conditions and identify ANXA1, encoding annexin A1, as a commonly highly expressed gene in non-activated ILC2s. The expression of ANXA1 decreases when ILC2s activate, but it increases autonomously as the activation subsides. Lentiviral vector-based gene transfer experiments show that ANXA1 suppresses the activation of human ILC2s. Mechanistically, ANXA1 regulates the expression of the metallothionein family genes, including MT2A, which modulate intracellular zinc homeostasis. Furthermore, increased intracellular zinc levels play an essential role in the activation of human ILC2s by promoting the mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) pathways and GATA3 expression. Thus, the ANXA1/MT2A/zinc pathway is identified as a cell-intrinsic metalloregulatory mechanism for human ILC2s.

Whole-embryonic identification of maternal microchimeric cell types in mouse using single-cell RNA sequencing

Even though the mother and the fetus of placental mammals are immunologically non-self with respect to one other, mutual exchange of small numbers of cells between them is known to occur. Maternal cells entering the fetus, called maternal microchimeric cells (MMc cells), are thought to be involved in different physiological phenomena, such as establishing immune tolerance, tissue repair, and the pathogenesis or deterioration of some inflammatory diseases and congenital malformations. While specific MMc cell types have been reported as associated with these phenomena, the contribution of MMc cells to these different outcomes remains unknown. As one possibility, we hypothesized that different embryos have differing repertoires of MMc cell types, leading to or biasing embryos toward different fates. To date, no studies have succeeded in identifying the MMc cell type repertoire of a single embryo. Accordingly, here, we isolated MMc cells from whole mouse embryos, determined their types, and analyzed their MMc cell type variability. By combining our previously established, whole-embryonic MMc isolation method with single-cell RNA sequencing, we successfully estimated the cell type repertoires of MMc cells isolated from 26 mouse embryos. The majority of MMc cells were immune-related cells, such as myeloid cells and granulocytes. We also detected stem cell-like MMc cells expressing proliferation marker genes and terminally differentiated cells. As hypothesized, we noted statistically significant inter-individual variation in the proportion of immune-related cells in the different embryos. We here successfully estimated MMc cell types in individual whole mouse embryos. The proportion of immune-related cells significantly differed among the individual embryos, suggesting that the variations are one of the potential mechanisms underlying the differing MMc-related physiological phenomena in offspring. These findings provide insight into cell-level epigenetics by maternal cells.

Upregulation of IL-4 receptor signaling pathway in circulating ILC2s from asthma patients

Background

Group 2 innate lymphoid cells (ILC2s) produce type 2 cytokines by stimulation with epithelial cell-derived cytokines and are implicated in the pathogenesis of various allergic diseases, including asthma. However, differences in the molecular characteristics of ILC2s between patients with asthma and healthy subjects remain unclear.

Objective

We sought to evaluate differences in cytokine production capacity and gene expression profile of ILC2s in the peripheral blood of patients with asthma and healthy subjects.

Methods

We evaluated ILC2s derived from 15 patients with asthma and 7 healthy subjects using flow cytometry, live-cell imaging of secretion activity analysis, and RNA-sequencing.

Results

ILC2s were sorted as CD45+Lineage-CRTH2+CD127+CD161+ cells from the peripheral blood of patients with asthma and healthy subjects, and the number of ILC2s was decreased in patients with asthma (851 ± 1134 vs 2679 ± 3009 cells/20 mL blood; P = .0066). However, patient-derived ILC2s were activated to produce more IL-5 and IL-13 in response to stimulation with IL-2, IL-33, and thymic stromal lymphopoietin compared with healthy subject-derived ILC2s (P = .0032 and P = .0085, respectively). Furthermore, RNA-sequencing analysis revealed that patient-derived ILC2s had different gene expression profiles, such as increased expression in cell growth-related genes (CDKN1b, CCNG2, CCND2, CCN1), prostaglandin E receptor (PTGER2), and IL-4 receptor. In addition, a gene set of the IL-4 receptor signaling pathway was significantly upregulated in ILC2s in patients with asthma (P = .042).

Conclusions

Our results suggest that circulating ILC2s in patients with asthma are preactivated via the IL-4 receptor signaling pathway and produce IL-5 and IL-13 vigorously by stimulation.

Nanaomycin E inhibits NLRP3 inflammasome activation by preventing mitochondrial dysfunction

The Nod-like receptor family pyrin domain containing 3 (NLRP3) is a cytosolic innate immune receptor that senses organelle dysfunction induced by various stimuli, such as infectious, environmental, metabolic, and drug stresses. Upon activation, NLRP3 forms an inflammasome with its adaptor protein apoptosis-associated speck-like protein, containing a caspase recruitment domain (ASC) and caspase-1, to trigger the release of inflammatory cytokines. The development of effective anti-inflammatory drugs targeting the NLRP3 inflammasome is in high demand as its aberrant activation often causes inflammatory diseases. Here, we found that nanaomycin A (NNM-A), a quinone-based antibiotic isolated from Streptomyces, effectively inhibited NLRP3 inflammasome-mediated inflammatory responses induced by imidazoquinolines, including imiquimod. Interestingly, its epoxy derivative nanaomycin E (NNM-E) showed a comparable inhibitory effect against the NLRP3 inflammasome-induced release of interleukin (IL)-1β and IL-18 from macrophages, with a much lower toxicity than NNM-A. NNM-E inhibited ASC oligomerization and caspase-1 cleavage, both of which are hallmarks of NLRP3 inflammasome activation. NNM-E reduced mitochondrial damage and the production of reactive oxygen species, thereby preventing the activation of the NLRP3 inflammasome. NNM-E treatment markedly alleviated psoriasis-like skin inflammation induced by imiquimod. Collectively, NNM-E inhibits NLRP3 inflammasome activation by preventing mitochondrial dysfunction with little toxicity and showed an anti-inflammatory effect in vivo. Thus, NNM-E could be a potential lead compound for developing effective and safe anti-inflammatory agents for the treatment of NLRP3 inflammasome-mediated inflammatory diseases.

Live-Cell Imaging Technique to Visualize DAMPs Release During Regulated Cell Death

The present protocol introduces a live-cell imaging of secretion activity (LCI-S) that is useful to visualize the real-time release of molecules from individual cells using an immunoassay coupled with total internal reflection fluorescence (FL) microscopy. This novel "live"-cell imaging technique has helped uncover the dynamics of regulated cell "death" by using this new approach. This protocol can observe the final stages of the regulated cell death process via single-cell imaging by targeting the extracellular release of damage-associated molecular patterns (DAMPs) from the cells expressing fluorescence resonance energy transfer (FRET) biosensors, such as a sensor for MLKL activation by RIPK3 based on FRET (SMART) and a sensor for caspase-1 activation based on FRET (SCAT1), which specifically identify the occurrence of regulated cell death processes.

Intelligent image-activated cell sorting 2.0

The advent of intelligent image-activated cell sorting (iIACS) has enabled high-throughput intelligent image-based sorting of single live cells from heterogeneous populations. iIACS is an on-chip microfluidic technology that builds on a seamless integration of a high-throughput fluorescence microscope, cell focuser, cell sorter, and deep neural network on a hybrid software-hardware data management architecture, thereby providing the combined merits of optical microscopy, fluorescence-activated cell sorting (FACS), and deep learning. Here we report an iIACS machine that far surpasses the state-of-the-art iIACS machine in system performance in order to expand the range of applications and discoveries enabled by the technology. Specifically, it provides a high throughput of ∼2000 events per second and a high sensitivity of ∼50 molecules of equivalent soluble fluorophores (MESFs), both of which are 20 times superior to those achieved in previous reports. This is made possible by employing (i) an image-sensor-based optomechanical flow imaging method known as virtual-freezing fluorescence imaging and (ii) a real-time intelligent image processor on an 8-PC server equipped with 8 multi-core CPUs and GPUs for intelligent decision-making, in order to significantly boost the imaging performance and computational power of the iIACS machine. We characterize the iIACS machine with fluorescent particles and various cell types and show that the performance of the iIACS machine is close to its achievable design specification. Equipped with the improved capabilities, this new generation of the iIACS technology holds promise for diverse applications in immunology, microbiology, stem cell biology, cancer biology, pathology, and synthetic biology.

Microfluidic Immunoassays for Time-Resolved Measurement of Protein Secretion from Single Cells

Measurement of humoral factors secreted from cells has served as an indispensable method to monitor the states of a cell ensemble because humoral factors play crucial roles in cell-cell interaction and aptly reflect the states of individual cells. Although a cell ensemble consisting of a large number of cells has conventionally been the object of such measurements, recent advances in microfluidic technology together with highly sensitive immunoassays have enabled us to quantify secreted humoral factors even from individual cells in either a population or a temporal context. Many groups have reported various miniaturized platforms for immunoassays of proteins secreted from single cells. This review focuses on the current status of time-resolved assay platforms for protein secretion with single-cell resolution. We also discuss future perspectives of time-resolved immunoassays from the viewpoint of systems biology.

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.

Author Correction: A practical guide to intelligent image-activated cell sorting

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A practical guide to intelligent image-activated cell sorting

Intelligent image-activated cell sorting (iIACS) is a machine-intelligence technology that performs real-time intelligent image-based sorting of single cells with high throughput. iIACS extends beyond the capabilities of fluorescence-activated cell sorting (FACS) from fluorescence intensity profiles of cells to multidimensional images, thereby enabling high-content sorting of cells or cell clusters with unique spatial chemical and morphological traits. Therefore, iIACS serves as an integral part of holistic single-cell analysis by enabling direct links between population-level analysis (flow cytometry), cell-level analysis (microscopy), and gene-level analysis (sequencing). Specifically, iIACS is based on a seamless integration of high-throughput cell microscopy (e.g., multicolor fluorescence imaging, bright-field imaging), cell focusing, cell sorting, and deep learning on a hybrid software-hardware data management infrastructure, enabling real-time automated operation for data acquisition, data processing, intelligent decision making, and actuation. Here, we provide a practical guide to iIACS that describes how to design, build, characterize, and use an iIACS machine. The guide includes the consideration of several important design parameters, such as throughput, sensitivity, dynamic range, image quality, sort purity, and sort yield; the development and integration of optical, microfluidic, electrical, computational, and mechanical components; and the characterization and practical usage of the integrated system. Assuming that all components are readily available, a team of several researchers experienced in optics, electronics, digital signal processing, microfluidics, mechatronics, and flow cytometry can complete this protocol in ~3 months.

A20 prevents inflammasome-dependent arthritis by inhibiting macrophage necroptosis through its ZnF7 ubiquitin-binding domain

Deficiency in the deubiquitinating enzyme A20 causes severe inflammation in mice, and impaired A20 function is associated with human inflammatory diseases. A20 has been implicated in negatively regulating NF-κB signalling, cell death and inflammasome activation; however, the mechanisms by which A20 inhibits inflammation in vivo remain poorly understood. Genetic studies in mice revealed that its deubiquitinase activity is not essential for A20 anti-inflammatory function. Here we show that A20 prevents inflammasome-dependent arthritis by inhibiting macrophage necroptosis and that this function depends on its zinc finger 7 (ZnF7). We provide genetic evidence that RIPK1 kinase-dependent, RIPK3-MLKL-mediated necroptosis drives inflammasome activation in A20-deficient macrophages and causes inflammatory arthritis in mice. Single-cell imaging revealed that RIPK3-dependent death caused inflammasome-dependent IL-1β release from lipopolysaccharide-stimulated A20-deficient macrophages. Importantly, mutation of the A20 ZnF7 ubiquitin binding domain caused arthritis in mice, arguing that ZnF7-dependent inhibition of necroptosis is critical for A20 anti-inflammatory function in vivo.

Addendum: A FRET biosensor for necroptosis uncovers two different modes of the release of DAMPs

The cDNA sequence of human SMART described in this Article was misreported, as described in the accompanying Addendum. This error does not affect the results or any conclusion of the Article.

Development of novel methods that monitor necroptosis and the release of DAMPs at the single cell resolution

Necroptosis is a regulated form of necrosis that depends on receptor-interacting protein kinase (RIPK)3 and mixed lineage kinase domain-like protein (MLKL). While danger-associated molecular pattern (DAMP)s are released from dead cells and involved in various pathological conditions, the mechanisms underlying regulation of the release of DAMPs are not fully understood. Apoptosis and pyroptosis can be detected by several types of sensors such as Forster resonance energy transfer (FRET) biosensors, termed SCAT1 (a sensor for caspase 1 activation based on FRET) and SCAT3, respectively. These sensors have provided better understanding of pyroptosis and apoptosis in vitro and in vivo. However, there have been no biosensors to monitor necroptosis. Development of a FRET biosensor that monitors necroptosis and generation of transgenic mice expressing such FRET biosensor might be useful to understand the mechanisms underlying the execution of necroptosis and also the consequences of necroptosis in vivo. In our recent study (Nat Commun, 9(1):4457), we developed a FRET biosensor for necroptosis, termed SMART (a sensor for MLKL activation by RIPK3 based on FRET). SMART is composed of a fragment of MLKL and monitors necroptosis, but not apoptosis or necrosis. Moreover, we recently developed a platform called Live-Cell Imaging for Secretion activity (LCI-S) to monitor protein secretion at the single cell level. This platform has enabled us to monitor the release of HMGB1 (High Mobility Group Box 1), one of the DAMPs, at the single cell level and reveals two different modes of the release of HMGB1 from necroptotic cells.

A FRET biosensor for necroptosis uncovers two different modes of the release of DAMPs

Necroptosis is a regulated form of necrosis that depends on receptor-interacting protein kinase (RIPK)3 and mixed lineage kinase domain-like (MLKL). While danger-associated molecular pattern (DAMP)s are involved in various pathological conditions and released from dead cells, the underlying mechanisms are not fully understood. Here we develop a fluorescence resonance energy transfer (FRET) biosensor, termed SMART (a sensor for MLKL activation by RIPK3 based on FRET). SMART is composed of a fragment of MLKL and monitors necroptosis, but not apoptosis or necrosis. Mechanistically, SMART monitors plasma membrane translocation of oligomerized MLKL, which is induced by RIPK3 or mutational activation. SMART in combination with imaging of the release of nuclear DAMPs and Live-Cell Imaging for Secretion activity (LCI-S) reveals two different modes of the release of High Mobility Group Box 1 from necroptotic cells. Thus, SMART and LCI-S uncover novel regulation of the release of DAMPs during necroptosis.

Necroptotic cells activate MLKL and release inflammatory DAMPs, although the underlying regulatory mechanisms of this process are poorly understood. Here, Murai et al. develop a necroptosis-specific FRET sensor (SMART) that monitors MLKL membrane translocation to identify two modes of DAMP release.

Single-cell imaging of caspase-1 dynamics reveals an all-or-none inflammasome signaling response

Inflammasome-mediated caspase-1 activation is involved in cell death and the secretion of the proinflammatory cytokine interleukin-1β (IL-1β). Although the dynamics of caspase-1 activation, IL-1β secretion, and cell death have been examined with bulk assays in population-level studies, they remain poorly understood at the single-cell level. In this study, we conducted single-cell imaging using a genetic fluorescence resonance energy transfer sensor that detects caspase-1 activation. We determined that caspase-1 exhibits all-or-none (digital) activation at the single-cell level, with similar activation kinetics irrespective of the type of inflammasome or the intensity of the stimulus. Real-time concurrent detection of caspase-1 activation and IL-1β release demonstrated that dead macrophages containing activated caspase-1 release a local burst of IL-1β in a digital manner, which identified these macrophages as the main source of IL-1β within cell populations. Our results highlight the value of single-cell analysis in enhancing understanding of the inflammasome system and chronic inflammatory diseases.

Toward an understanding of immune cell sociology: real-time monitoring of cytokine secretion at the single-cell level

The immune system is a very complex and dynamic cellular system, and its intricacies are considered akin to those of human society. Disturbance of homeostasis of the immune system results in various types of diseases; therefore, the homeostatic mechanism of the immune system has long been a subject of great interest in biology, and a lot of information has been accumulated at the cellular and the molecular levels. However, the sociological aspects of the immune system remain too abstract to address because of its high complexity, which mainly originates from a large number and variety of cell-cell interactions. As long-range interactions mediated by cytokines play a key role in the homeostasis of the immune system, cytokine secretion analyses, ranging from analyses of the micro level of individual cells to the macro level of a bulk of cell ensembles, provide us with a solid basis of a sociological viewpoint of the immune system. In this review, as the first step toward a comprehensive understanding of immune cell sociology, cytokine secretion of immune cells is surveyed with a special emphasis on the single-cell level, which has been overlooked but should serve as a basis of immune cell sociology. Now that it has become evident that large cell-to-cell variations in cytokine secretion exist at the single-cell level, we face a tricky yet interesting question: How is homeostasis maintained when the system is composed of intrinsically noisy agents? In this context, we discuss how the heterogeneity of cytokine secretion at the single-cell level affects our view of immune cell sociology. While the apparent inconsistency between homeostasis and cell-to-cell heterogeneity is difficult to address by a conventional reductive approach, comparison and integration of single-cell data with macroscopic data will offer us a new direction for the comprehensive understanding of immune cell sociology.

Single-molecule tracking of mRNA in living cells

Some mRNAs localize to specific regions within eukaryotic cells to express their functions. The movement and localization of mRNA molecules provides valuable information about how they concentrate to particular regions. Recent technical advances in optical microscopy and image analysis algorithms enable real-time tracking of single mRNA molecules in living cells. This chapter presents the methods to visualize and track single β-actin mRNA molecules that localize at the leading edge of chicken embryo fibroblasts. Furthermore, this chapter presents an analysis approach for single-molecule tracking data to extract quantitative information about the microenvironments of the mRNA molecules.

Integration in a multilayer microfluidic chip of 8 parallel cell sorters with flow control by sol-gel transition of thermoreversible gelation polymer

Microfluidic systems have significant implications in the field of cell separation since they could provide platforms with inexpensive, disposable and sterile structures. Here, we present a novel strategy to integrate microfluidic sorters into a single chip for high throughput sorting. Our parallel sorter consists of a microfluidic chip with a three-dimensional channel network that utilizes flow switching by a heat-induced sol-gel transition of thermoreversible gelation polymer. The 8 parallel sheathed sample flows were realized by injecting sample and buffer solutions into only 2 inlets. The sheathed flows enabled disposal of unwanted sample waste without laser irradiation, and collection of wanted sample upon irradiation. As an application of the sorter, two kinds of fluorescent microspheres were separated with recovery ratio and purity of 70% or 90% at throughputs of about 100 or 20 particles per second, respectively. Next, Escherichia coli cells expressing green fluorescent protein were separated from those expressing DsRed with recovery ratio and purity of 90% at a throughput of about 20 cells per second.

On-chip microfluidic sorting with fluorescence spectrum detection and multiway separation

The microfluidic platform is an important tool for diagnosis and biomedical studies because it enables us to handle precious cells and infectious materials safely. We have developed an on-chip microfluidic sorter with fluorescence spectrum detection and multiway separation. The fluorescence spectrum of specimens (495-685 nm) in the microchannels was obtained every 2 ms using a 1 x 16 arrayed photomultiplier tube. The specimen was identified by its spectrum and collected into the corresponding channel based on our previously reported thermoreversible gelation polymer technique (Y. Shirasaki, J. Tanaka, H. Makazu, K. Tashiro, S. Shoji, S. Tsukita and T. Funatsu, Anal. Chem., 2006, 78, 695-701). Four kinds of fluorescence microspheres and three kinds of Escherichia coli cells, expressing different fluorescent proteins, were successfully separated with accuracy and purity better than 90% at a throughput of about one particle per second.

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.

[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.

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.

Experimental joint contracture correction with low torque--long duration repeated stretching

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.

An optical spectrum of the afterglow of a γ-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.

On-Chip Cell Sorting System Using Laser-Induced Heating of a Thermoreversible Gelation Polymer to Control Flow

We have developed a microfabricated fluorescence-activated cell sorter system using a thermoreversible gelation polymer (TGP) as a switching valve. The glass sorter chip has Y-shaped microchannels with one inlet and two outlets. A biological specimen containing fluorescently labeled cells is mixed with a solution containing a thermoreversible sol-gel polymer. The mixed solution is then introduced into the sorter chip through the inlet. The sol-gel transformation was locally induced by site-directed infrared laser irradiation to plug one of the outlets. The fluorescently labeled target cells were detected with sensitive fluorescence microscopy. In the absence of a fluorescence signal, the collection channel is plugged through laser irradiation of the TGP and the specimens are directed to the waste channel. Upon detection of a fluorescence signal from the target cells, the laser beam is then used to plug the waste channel, allowing the fluorescent cells to be channeled into the collection reservoir. The response time of the sol-gel transformation was 3 ms, and a flow switching time of 120 ms was achieved. Using this system, we have demonstrated the sorting of fluorescent microspheres and Escherichia coli cells expressing fluorescent proteins. These cells were found to be viable after extraction from the sorting system, indicating no damage to the cells.

Discovery of the short γ-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.

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.

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.

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.

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.

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.

Effect of low-level laser therapy (LLLT) on viscoelasticity of the contracted knee joint: comparison with whirlpool treatment in rats

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.

Laser's effect on bone and cartilage change induced by joint immobilization: an experiment with animal model

OBJECTIVE

Influence of low-level (810 nm, Ga-Al-As semiconductor) laser on bone and cartilage during joint immobilization was examined with rats' knee model.

MATERIALS AND METHODS

The hind limbs of 42 young Wistar rats were operated on in order to immobilize the knee joint. One week after operation they were assigned to three groups; irradiance 3.9 W/cm2, 5.8 W/cm2, and sham treatment. After 6 times of treatment for another 2 weeks both hind legs were prepared for 1) indentation of the articular surface of the knee (stiffness and loss tangent), and for 2) dual energy X-ray absorptiometry (bone mineral density) of the focused regions.

RESULTS AND CONCLUSIONS

The indentation test revealed preservation of articular cartilage stiffness with 3.9 and 5.8 W/cm2 therapy. Soft laser treatment has a possibility for prevention of biomechanical changes by immobilization.

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.

[A comparative study of a thick and standard loop in transurethral resection of the prostate]

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.

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.

Dynamic viscoelastic properties of models composed of posterior denture teeth and denture base resin

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.

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.

Rigix plate system for anterior fixation of thoracolumbar vertebrae

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.

Electrical stimulation on joint contracture: an experiment in rat model with direct current

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.

Localized osteoarticular change due to joint immobilization; biomechanical test and bone densitometry in rat's hind limb model

Bone change induced by knee immobilization was assessed on dissected femurs and tibias to clarify the influences upon the mechanical properties and their demands. Fifty-eight Wistar-Imamichi male rats (11-12 weeks old, body weight 350-450 g) were subjected to knee joint immobilization (150 degrees flexed position) on one side while the opposite side served as a control. Animals were killed in seven groups at time intervals of 1, 2, 3, 4, 5, 7, and 10 weeks. The hind leg was extirpated and prepared for (1) biomechanical analysis by the indentation method at the articular surfaces of the femoral condyle and head and at the subchondral bone of the proximal tibia, and for (2) dual-energy X-ray absorptiometry of the distal metaphysis of the femur. The biomechanical parameters measured induced dynamic stiffness and phase lag derived from forced oscillation (preload 3 N, cyclic load 2 N and 11 Hz, 35 Hz), and bone mineral density was analyzed. These were compared between the immobilized side and control side, and among the seven time groups. The biomechanical results showed an early change of osteocartilaginous properties at the femoral condyle, a late response at the tibial subchondral bone, and no change at the femoral head. The measurement of bone mineral density revealed that a very sensitive reaction started within 1-2 weeks. This study provides objective data demonstrating that disuse or lack of mechanical stress greatly affects the remodeling activity for homeostasis of joints, and dramatically impairs normal bone mineral density next to the immobilized joint in young animals.

Processing of beta/A4 amyloid precursor protein is altered in the hippocampus of reserpinized rat brain

Immunoreactivities of beta/A4 amyloid precursor protein (APP) and soluble derivative of APP (APPs) were determined in the hippocampus and the striatum of reserpinized rat brains. Significant decrease of APPs immunoreactivity was observed in the cytosolic fraction of hippocampus, but not of striatum, whereas APP immunoreactivity was found to be increased in the membrane fraction of hippocampus. These findings suggest that processing of APP in hippocampus may be regulated through the monoaminergic signal transduction system.