Phenotype Analysis and Quantification of Proliferating Cells in the Cortical Gray Matter of the Adult Rat

In intact adult mammalian brains, there are two neurogenic regions: the subependymal zone and the subgranular layer of the hippocampus. Even outside these regions, small numbers of proliferating precursors do exist. Many studies suggest that the majority of these are oligodendrocyte precursors that express NG2, a chondroitin sulfate proteoglycan, and most of the residual proliferating cells seem to be endothelial cells. However, it is still unclear whether NG2-immunonegative proliferating precursors are present, because previous studies have neglected their possible existence. In this study, we systematically analyzed the phenotypes of the proliferating cells in the intact adult rat cortical gray matter. We improved our techniques and carefully characterized the proliferating cells, because there were several problems with identifying and quantifying the proliferating cells: the detection of NG2-expressing cells was dependent on the fixation condition; there were residual proliferating leukocytes in the blood vessels; and two anti-NG2 antibodies gave rise to different staining patterns. Moreover, we used two methods, BrdU and Ki67 immunostaining, to quantify the proliferating cells. Our results strongly suggest that in the intact adult cerebral cortical gray matter, there were only two types of proliferating cells: the majority were NG2-expressing cells, including pericytes, and the rest were endothelial cells

Differential expression of nuclear lamin subtypes in the neural cells of the adult rat cerebral cortex

Lamins are type V intermediate filament proteins that are located beneath the inner nuclear membrane. In mammalian somatic cells, LMNB1 and LMNB2 encode somatic lamins B1 and B2, respectively, and the LMNA gene is alternatively spliced to generate somatic lamins A and C. Mutations in lamin genes have been linked to many human hereditary diseases, including neurodegenerative disorders. Knowledge about lamins in the nervous system has been accumulated recently, but a precise analysis of lamin subtypes in glial cells has not yet been reported. In this study we investigated the composition of lamin subtypes in neurons, astrocytes, oligodendrocyte-lineage cells, and microglia in the adult rat cerebral cortex using an immunohistochemical staining method. Lamin A was not observed in neurons and glial cells. Lamin C was observed in astrocytes, mature oligodendrocytes and neurons, but not observed in oligodendrocyte progenitor cells. Microglia also did not stain positive for lamin C which differed from macrophages, with lamin C positive. Lamin B1 and B2 were observed in all glial cells and neurons. Lamin B1 was intensely positive in oligodendrocyte progenitor cells compared with other glial cells and neurons. Lamin B2 was weakly positive in all glial cells compared to neurons. Our current study might provide useful information to reveal how the onset mechanisms of human neurodegenerative diseases are associated with mutations in genes for nuclear lamin proteins

On-Orbit Construction Experiment by Tele-Operated Robot Arm

On-orbit assembly technology is a key for future large-scale structure construction. For several decades, many concepts of space structures have been proposed and some of them have the idea of robotic construction systems. Authors have developed a concept of a truss joint system for large-scale orbital structures and worked for space robotics research. Participating aJapanese space robotics experiment project on Engineering Test Satellite No. 7 scheduled to be launched by NASDA in 1997, the authors will conduct spare truss construction experiments. The experiments have objectives to establish basic technologies of on-orbit assembly work and robotic construction by using NA SDA's manipulator on the satellite. Our experiment system consists of the experiment unit including a truss joint anda deployable truss on the satellite, and our teleoperation facility on the ground The on-board truss unit has been tested in both vibration and thermal vacuum conahtions simulating orbit environment, and the ground teleoperation facility has been developed The actual experiments will start in late 1997. 1

Truss structure tele-manipulation experiment using ETS-7

A robot experiment concept of space truss telemanipulation by National Aerospace Laboratory (NAL) is described in its flight model development. The experiment will be carried out on the Engineering Test Satellite No. 7 (ETS-7) using its robot arm. The satellite is scheduled to be launched in 1997 by National Space Development Agency of Japan (NASDA). The truss flight model is composed of deployable truss system and assemble truss joint. Those truss components will be manipulated by the ETS-7 robot arm using its small grapple fixture type-N (GPF-N), and the experimental task operation will be executed from the ground control station

A Case of Giant Mesenteric Cyst Originating from the Small Intestine

A 62-year-old man was admitted to Showa University Fujigaoka Hospital because of a giant mass that was discovered approximately 8 weeks after the development of obvious symptoms, namely upper abdominal pain, vomiting, and progressive distension. Ultrasonography revealed a giant cystic mass that was occupying the right upper abdomen, and contrast-enhanced computed tomography revealed a huge, relatively well-defined, and low-density cystic mass that measured 10cm in diameter. Radical resection of the tumor was performed via open laparotomy, along with segmental small intestine resection to address potential invasion into adjacent tissues. Histological findings of the resected specimen indicated mesenteric cyst. The patient\u27s postoperative recovery was uneventful and he was discharged after 11 days. At the 12-month follow-up, the patient was in good health with no signs of recurrence

A New Device Facilitating Intracorporeal Purse-string Suture during Endoscopic Surgery

Standard laparoscopic colorectal surgery requires additional incision or enlargement of the trocar incision for the retrieval of the surgical specimen. A natural orifice specimen extraction （NOSE） procedure, in which the specimen is retrieved through the anus or vagina without any additional skin incision, requires purse-string suture （PSS） of the rostral intestinal segment in order to fix the anvil head of the stapler and perform extracorporeal mechanical anastomosis. Colorectal surgery has a limited NOSE in cases where the end of the rostral segment could be pulled through the anus. Broader application of NOSE depends on intracorporeal PSS. We developed a new forceps for intracorporeal PSS during NOSE and evaluated its efficacy. The PSS instrument was refined to pass through a 12-mm trocar in an intracorporeal PSS and achieve anastomosis using double stapling. In trials utilizing an endoscopic practice box, regular spacing of stitches during PSS were consistent （n＝10）, and tight intracorporeal anastomosis of the porcine colon was successfully performed （n＝2）. We then confirmed efficacy through an operation on a pig. Our novel PSS device will help us perform NOSE not only in laparoscopic colorectal surgery but also in any operation requiring intracorporeal PSS, which should contribute to further advances in endoscopic digestive surgery

Delphi consensus on bile duct injuries during laparoscopic cholecystectomy:An evolutionary cul-de-sac or the birth pangs of a new technical framework?

Bile duct injury (BDI) during laparoscopic cholecystectomy remains a serious iatrogenic surgical complication. BDI most often occurs as a result of misidentification of the anatomy; however, clinical evidence on its precise mechanism and surgeons' perceptions is scarce. Surgeons from Japan, Korea, Taiwan, and the USA, etc. (n=614) participated in a questionnaire regarding their BDI experience and near-misses; and perceptions on landmarks, intraoperative findings, and surgical techniques. Respondents voted for a Delphi process and graded each item on a five-point scale. The consensus was built when 80% of overall responses were 4 or 5. Response rates for the first- and second-round Delphi were 60.6% and 74.9%, respectively. Misidentification of local anatomy accounted for 76.2% of BDI. Final consensus was reached on: (1) Effective retraction of the gallbladder, (2) Always obtaining critical view of safety, and (3) Avoiding excessive use of electrocautery/clipping as vital procedures; and (4) Calot's triangle area and (5) Critical view of safety as important landmarks. For (6) Impacted gallstone and (7) Severe fibrosis/scarring in Calot's triangle, bail-out procedures may be indicated. A consensus was reached among expert surgeons on relevant landmarks and intraoperative findings and appropriate surgical techniques to avoid BD

Sox2 promotes survival of satellite glial cells in vitro

Sox2 is a transcriptional factor expressed in neural stem cells. It is known that Sox2 regulates cell differentiation, proliferation and survival of the neural stem cells. Our previous study showed that Sox2 is expressed in all satellite glial cells of the adult rat dorsal root ganglion. In this study, to examine the role of Sox2 in satellite glial cells, we establish a satellite glial cell-enriched culture system. Our culture method succeeded in harvesting satellite glial cells with the somata of neurons in the dorsal root ganglion. Using this culture system, Sox2 was downregulated by siRNA against Sox2. The knockdown of Sox2 downregulated ErbB2 and ErbB3 mRNA at 2 and 4 days after siRNA treatment. MAPK phosphorylation, downstream of ErbB, was also inhibited by Sox2 knockdown. Because ErbB2 and ErbB3 are receptors that support the survival of glial cells in the peripheral nervous system, apoptotic cells were also counted. TUNEL-positive cells increased at 5 days after siRNA treatment. These results suggest that Sox2 promotes satellite glial cell survival through the MAPK pathway via ErbB receptors

Increased Histone H3 Phosphorylation in Neurons in Specific Brain Structures after Induction of Status Epilepticus in Mice

Status epilepticus (SE) induces pathological and morphological changes in the brain. Recently, it has become clear that excessive neuronal excitation, stress and drug abuse induce chromatin remodeling in neurons, thereby altering gene expression. Chromatin remodeling is a key mechanism of epigenetic gene regulation. Histone H3 phosphorylation is frequently used as a marker of chromatin remodeling and is closely related to the upregulation of mRNA transcription. In the present study, we analyzed H3 phosphorylation levels in vivo using immunohistochemistry in the brains of mice with pilocarpine-induced SE. A substantial increase in H3 phosphorylation was detected in neurons in specific brain structures. Increased H3 phosphorylation was dependent on neuronal excitation. In particular, a robust upregulation of H3 phosphorylation was detected in the caudate putamen, and there was a gradient of phosphorylated H3+ (PH3+) neurons along the medio-lateral axis. After unilateral ablation of dopaminergic neurons in the substantia nigra by injection of 6-hydroxydopamine, the distribution of PH3+ neurons changed in the caudate putamen. Moreover, our histological analysis suggested that, in addition to the well-known MSK1 (mitogen and stress-activated kinase)/H3 phosphorylation/c-fos pathway, other signaling pathways were also activated. Together, our findings suggest that a number of genes involved in the pathology of epileptogenesis are upregulated in PH3+ brain regions, and that H3 phosphorylation is a suitable indicator of strong neuronal excitation