Efficacy of redox nanoparticles for improving survival of transplanted cells in a mouse model of ischemic stroke.

The success of cell transplantation therapy for ischemic stroke is hindered by the low cell survival rate in poststroke brain, due in part to high free radical production and ensuing oxidative stress. We have developed redox nanoparticles to eliminate reactive oxygen species. In this study, we tested the protective efficacy of these redox nanoparticles in cell culture and a mouse model of ischemic stroke. Induced human dental pulp stem cells were subjected to oxygen-glucose deprivation and reoxygenation to recapitulate ischemia and reperfusion in the penumbra surrounding a cerebral infarct. Cell viability using WST-8 assay, apoptosis using TUNEL, free radicals using MitoSOX, and inflammatory cytokines using ELISA kit were measured in the presence and absence of redox nanoparticles after oxygen-glucose deprivation and reoxygenation. The scavenging activity of redox nanoparticles against reactive oxygen species was detected by electron spin resonance. Moreover, induced cells were transplanted intracerebrally into to the distal middle cerebral artery occlusion model with and without redox nanoparticles, and the survival rate measured. Cell viability was enhanced, while apoptosis, free radical generation, and inflammatory cytokine expression levels were reduced in cultures with redox nanoparticles. Further, reduced redox nanoparticles were detected in the cytoplasm, indicating free radical scavenging. Addition of redox nanoparticles also improved the survival rate of transplanted cells after 6 weeks in vivo. These redox nanoparticles may increase the applicability and success of induced stem cell therapy for ischemic stroke patents by promoting long-term survival.

Transplanted neural lineage cells derived from dental pulp stem cells promote peripheral nerve regeneration.

Cell therapy for peripheral nerve injury is a promising strategy as regenerative medicine that restores neurological function. However, challenges remain in producing suitable and sufficient amounts of autologous cells for promoting nerve regeneration. This study aimed to identify the characteristics of neural lineage cells (NLCs) differentiated from dental pulp stem cells (DPSCs) and reveal their effect on functional recovery and nerve regeneration after cell transplantation into an immunodeficient rat using a nerve guide conduit. Here we report a protocol of neural induction in monolayer culture and characterize NLCs in vitro. Furthermore, NLCs were transplanted into an immunodeficient rat model with a 10-mm sciatic nerve defect, and cell survival and differentiation were investigated in vivo. Outcomes of nerve regeneration were also assessed using the remyelinated axon numbers, myelin sheath thickness, electrophysiological activities, and gastrocnemius muscle mass. NLCs comprised neuronal, astrocyte, oligodendrocyte, and neural crest lineage cells. NLCs enhanced the activities of endothelial cells, Schwann cells, and neurons in a paracrine-dependent manner in vitro. At 2 weeks post-transplantation, numerous transplanted NLCs differentiated into platelet-derived growth factor receptor alpha (PDGFRα) + oligodendrocyte progenitor cells (OPCs) and a few PDGFRα + /p75 neurotrophin receptor + Schwann cell-like cells derived from OPCs were observed. At 12 weeks post-transplantation, human Schwann cell-like cells survived, and axon growth, remyelination, electrophysiological activities, and muscle atrophy were improved. This study demonstrates the broad application of our protocol of neural induction of DPSCs and portrays the efficacy of transplantation of NLCs derived from human DPSCs as a promising strategy for peripheral nerve regeneration.

Induced Neural Cells from Human Dental Pulp Ameliorate Functional Recovery in a Murine Model of Cerebral Infarction.

Human mesenchymal stem cells are a promising cell source for the treatment of stroke. Their primary mechanism of action occurs via neuroprotective effects by trophic factors, anti-inflammatory effects, and immunomodulation. However, the regeneration of damaged neuronal networks by cell transplantation remains challenging. We hypothesized that cells induced to neural lineages would fit the niche, replace the lesion, and be more effective in improving symptoms compared with stem cells themselves. We investigated the characteristics of induced neural cells from human dental pulp tissue and compared the transplantation effects between these induced neural cells and uninduced dental pulp stem cells. Induced neural cells or dental pulp stem cells were intracerebrally transplanted 5 days after cerebral infarction induced by permanent middle cerebral artery occlusion in immunodeficient mice. Effects on functional recovery were also assessed through behavior testing. We used immunohistochemistry and neuron tracing to analyze the differentiation, axonal extension, and connectivity of transplanted cells to the host's neural circuit. Transplantation of induced neural cells from human dental pulp ameliorated functional recovery after cerebral infarction compared with dental pulp stem cells. The induced neural cells comprised both neurons and glia and expressed functional voltage, and they were more related to neurogenesis in terms of transcriptomics. Induced neural cells had a higher viability than did dental pulp stem cells in hypoxic culture. We showed that induced neural cells from dental pulp tissue offer a novel therapeutic approach for recovery after cerebral infarction.

Characterization and comparative DNA methylation profiling of four adipogenic genes in adipose-derived stem cells and dedifferentiated fat cells from aging subjects.

Adipose-derived stem cells (ASCs) and dedifferentiated fat (DFAT) cells are alternative cell sources in tissue engineering and regeneration because they are easily obtained and exhibit multilineage differentiation. However, aging may attenuate their regenerative potential and metabolic functions. Reports characterizing DFAT cells derived from aging donors are rare, and comparisons of DNA methylation profiles between aging ASCs and DFAT cells are poorly understood. Therefore, this study aimed to characterize DFAT cells relative to ASCs derived from aging subjects and compare the DNA methylation profiles of four adipogenic genes in these cells. ASCs and DFAT cells from aging donors exhibited characteristics similar to those of stem cells, including colony formation, proliferation, and multilineage differentiation abilities. However, compared with ASCs, DFAT cells exhibited increased proliferation, smooth muscle actin alpha (SMA-α) expression and decreased cellular senescence. DNA methylation profiling of ASCs and DFAT cells by combined bisulfite restriction analysis (COBRA) demonstrated hypermethylation patterns in three potent adipogenic genes-peroxisome proliferator-activated receptor gamma 2 (PPARγ2), fatty acid-binding protein 4 (FABP4), and lipoprotein lipase (LPL)-but hypomethylation of CCAAT/enhancer binding protein alpha (C/EBPα) in the aging group. Statistically significant differences were observed between the aging group and the young group. Epigenetic regulation maintains the stability of ASCs and DFAT cells in an age-dependent manner. Our findings suggested that although the DNA methylation patterns of three adipogenic genes correlated with hypermethylation and aging, ASCs and DFAT cells exhibited cellular stability and several stem cell characteristics, offering further opportunities for personalized regeneration and energy maintenance by adipogenesis during aging.

Correction to: Three-dimensional bone formation including vascular networks derived from dental pulp stem cells in vitro.

The authors would like to correct the error in the publication of the original article.

Three-dimensional bone formation including vascular networks derived from dental pulp stem cells in vitro.

The regeneration of bone tissue is an active area of research, and future clinical applications are expected. Here, to establish new bone graft materials and an experimental bone tissue model, we generated united compact and spongy bone tissues containing vascular networks from human dental pulp stem cells in vitro. We applied the cell bead and cell sheet methods to construct three-dimensional bone tissue, which was cultured using a circumfusion apparatus for 30 days. Using micro-computed tomography, we assessed structural differences between compact and spongy bone. Histological examinations revealed the presence of bone lacunae containing osteocytes, Haversian canal-like structures, and extensive vascularization. Furthermore, tartrate-resistant acid phosphatase (TRAP) staining-positive osteoclast-like cells were also observed. Thus, the bone tissue generated using this method closely resembles native bone tissue and may possess bone remodeling ability. We successfully generated bone tissue containing blood vessel networks in vitro using this method. The generated bone tissue will likely be highly applicable to medical care, the study of osteogenesis, drug-screening assays, and drug development for bone tissue.

Establishment and characterization of human gingival squamous cell carcinoma cell line NOCS-1.

The NOCS-1 cell line was established from the left gingiva tumor in an 86-year-old Japanese man. Histopathological diagnosis of the original tumor was well-differentiated squamous cell carcinoma. NOCS-1 cells were adhesive epithelial cells with neoplastic or pleomorphic features and grew without contact inhibition. It has been subcultured 70 times during the past 26 months. From passage 3, melanin-containing cells began to be observed in the NOCS-1 cell line. The plating efficiencies were 25% and 23%, doubling times were 29 and 26 h, and saturation densities were 6.9 × 104/cm2 and 8.7 × 104/cm2, at passage 12 and 30, respectively. When NOCS-1 cells were xenotransplanted subcutaneously into SCID mice, they produced tumors that histopathologically resembled the original tumor. In addition, NOCS-1-XG cells derived from the xenotransplanted tumor were similar to NOCS-1 cells. We believe that this cell line may be a valuable tool to develop immunotherapy and chemotherapy regimens.

Prolactin selectively transported to cerebrospinal fluid from blood under hypoxic/ischemic conditions.

AIM: The aim of this study was to determine and to verify the correlation between the amount of prolactin (PRL) levels in the blood and in the cerebrospinal fluid (CSF) by various causes of death as an indicator for acute hypoxia in autopsy cases. It is to confirm the cause of the change in prolactin level in CSF by in vitro system. MATERIALS AND METHODS: In autopsy materials, the PRL levels in blood from the right heart ventricle and in the CSF were measured by chemiluminescent enzyme immunoassay, and changes in the percentage of PRL-positive cells in the pituitary gland were examined using an immunohistochemical method. Furthermore, an inverted culture method was used as an in vitro model of the blood-CSF barrier using epithelial cells of the human choroid plexus (HIBCPP cell line) and SDR-P-1D5 or MSH-P3 (PRL-secreting cell line derived from miniature swine hypophysis) under normoxic or hypoxic (5% oxygen) conditions, and as an index of cell activity, we used Vascular Endothelial Growth Factor (VEGF). RESULTS AND DISCUSSION: Serum PRL levels were not significantly different between hypoxia/ischemia cases and other causes of death. However, PRL levels in CSF were three times higher in cases of hypoxia/ischemia than in those of the other causes of death. In the cultured cell under the hypoxia condition, PRL and VEGF showed a high concentration at 10 min. We established a brain-CSF barrier model to clarify the mechanism of PRL transport to CSF from blood, the PRL concentrations from blood to CSF increased under hypoxic conditions from 5 min. These results suggested that PRL moves in CSF through choroidal epithelium from blood within a short time. PRL is hypothesized to protect the hypoxic/ischemic brain, and this may be because of the increased transportation of the choroid plexus epithelial cells.

Establishment and characterization of a clear cell carcinoma cell line, designated NOCC, derived from human ovary.

A cell line, designated NOCC, was established from the ascites of a patient with clear cell adenocarcinoma of the ovary. The cell line has been grown without interruption and continuously propagated by serial passaging (more than 76 times) over 7 years. The cells are spherical to polygonal-shaped, display neoplastic, and pleomorphic features, and grow in a jigsaw puzzle-like pattern while forming monolayers without contact inhibition. The cells proliferate rapidly, but are easily floated as a cell sheet. The population doubling time is about 29 h. The number of chromosomes ranges from 60 to 83. The modal number of chromosomes is 70-74 at the 30th passage. NOCC cells secreted 750.5 ng/ml of VEGF over 3 days of culture. Hypoxia inducible factor-1α (HIF-1α) is a primary regulator of VEGF under hypoxic conditions. NOCC cells were not sensitive to the anticancer drugs BEV, DOX, GEM, ETP, CDDP, or TXT. The graft of NOCC cells to a scid mouse displayed similar histological aspects to the original tumor. Both the NOCC cells and the graft of the NOCC cells gave a positive PAS reaction.

Establishment and characterization of a cell line designated Nur-1 derived from human endometrioid adenocarcinoma of uterine corps.

A new cell line designated Nur-1 has been established from human endometrioid adenocarcinoma, Grade 1, pT1a, PN1 (3/24), Stage IIIc (International Federation of Gynecology and Obstetrics/Union for International Cancer Control (FIGO/UICC TNM Classification of Malignant Tumours, 7th ed.). Cytological findings of Nur-1 cells reveal anaplastic and pleomorphic features such as anisonucleosis, nucleolar pleomorphism, and piling-up tendency in cellular arrangement. Distribution of the chromosome number is found at the hyperploid range, and the apparent marker chromosome has not been identified. The original tumor and graft of the Nur-1 cell line had a large amount of estrogen receptors and progesterone receptors, as revealed by immunohistochemistry. The cytokeratin pattern of the tumor was positive for cytokeratin-7 and negative for cytokeratin-20. However, a few cells were positive for cytokeratin-20 in the original tumor. Nur-1 cells express mRNA of estrogen receptors and progesterone receptors, cytokeratin-7, and cytokeratin-20 at 105 passages. These findings are consistent with the cytokeratin pattern of endometrial glandular cells. The cells make contact with each other via interdigitation and desmosomes. They possess bundles of microtubules and tonofilaments and many free ribosomes. Some cells have various sizes of phagosomes. The Nur-1 cell line exceeded 102 passages in 5 years, and multiplication of the cells is stable. The modal number of the Nur-1 cell line is 91-92 (56 %). The Nur-1 cells develop well-differentiated adenocarcinoma in tumors sustained in nude mice that resemble the original tumors.

Establishment and characterization of the rhabdomyosarcoma cell line designated NUTOS derived from the human tongue sarcoma: Special reference to the susceptibility of anti-cancer drugs.

Primary alveolar type of rhabdomyosarcoma (RMS) tumor tissue was collected from the tongue of a 17-year-old Japanese woman and used to successfully establish a rhabdomyosarcoma cell line, which has been designated NUTOS. The chromosomal distribution revealed that the NUTOS cell line was hyper-tetraploid with chromosomal translocation. The cells were grown in Dulbecco's modified eagle medium/F12 supplemented with 15% fetal bovine serum, 0.1% non-essential amino acids solution (NEAA), 50 microg of streptomycin, 50 U/mL of penicillin and 0.25 microg /mL of Fungizone. The NUTOS shapes included small spindles, large spindles and long, thick multinucleated cells. All three cell types were immunostained with anti-desmin antibody, which is a marker protein for middle sized myofilaments. Furthermore, immunocytochemical staining revealed that the cells were positively immunostained with anti-MyoD, myogenin, alpha-sarcomeric actin, myosin and troponin T. Mitotic figures were only observed in the small spindle cells. These cells were coadunated with each other at the lateral portion of the apex of the cells. Subsequently, these cells grew into large multinucleated cells. Autonomic contractions (approximately 20 times/min) were observed in both the large spindle cells and the large multinucleated cells. NUTOS cells incorporated serotonin from the serum in the growth medium. Histopathological observations of the NUTOS cell grafts in the subcutis of nude mice exhibited characteristics similar to those seen for the primary rhabdomyosarcoma of the tongue. Susceptibility tests for the anti-cancer drugs revealed that NUTOS cells were susceptive to cisplatin, paclitaxel, and docetaxel, but not to adriacin.

Novel amelanotic and melanotic cell lines NM78-AM and NM78-MM derived from a human oral malignant melanoma.

Abstract Novel cell lines, designated NM78-AM and NM78-MM, have been established from a malignant melanoma of the cheek oral mucosa. NM78-AM cells were spherical, grew in suspension as clusters, and produced no melanin. In contrast, NM78-MM cells were adherent and produced melanin granules. Initially, NM78-AM cells were grown on fibroblast feeder cells or in growth media supplemented with 10% conditioned medium from fibroblasts, but eventually grew in standard growth media alone. NM78-AM cells had interdigitating microvilli and formed cell clusters. They had large nucleoli, desmosomes, lipid droplets, and well-developed Golgi apparatuses. In contrast, NM78-MM cells grew as adherent neuron-like cells. They had large prominent nucleoli, irregular nuclear membranes, a number of mitochondria, well-developed Golgi apparatuses, melanosomes at various stages of development in the cytoplasm, and the cells secreted melanin granules. Projections from these melanotic cells formed anastomoses with each other. NM78-MM cells stained immunofluorescently for internexin, neuron specific enolase, NF-200, and glial fibrillary acidic protein. These cells were severely aneuploid, approximating to triploidy, and had many marker chromosomes. We used a real-time monitoring system to evaluate oxygen concentrations in culture medium to investigate the susceptibility of both cell lines to various anti-cancer drugs. NM78-AM cells were slightly sensitive to actinomycin D, but not to cisplatin, irinotecan, the irinotecan metabolite SN-38, taxol, taxotere, bleomycin and methotrexate; NM78-MM cells were sensitive to cisplatin, and not to taxol, taxotere, carboplatin, and irinotecan. These new cell lines, NM78-AM and NM78-MM, will be very important for the development of new chemotherapeutics for oral malignant melanoma.

Establishment and characterization of the NEYS cell line derived from carcinosarcoma of human ovary with special reference to the susceptibility test of anticancer drugs.

A cell line designated as NEYS was established from ovarian carcinosarcoma (stage IIIc) of a 56-year-old Japanese woman. The extirpated original tumor was carried in growth medium at 0 degrees C to the culture room. The primary culture was done on 20 August 2003. The cell line was composed of angular adhesive cells and showed neoplastic and pleomorphic features, such as bizarre aggregation of chromatin granules, an irregular thickening nuclear membrane and multiple large nucleoli. They grew as multi-layered cultures without contact inhibition. The cells proliferated moderately, and population doubling time was about 56 h. The chromosome number showed an underdiploidy of aneuploidy. The modal chromosome numbers were 37 (36%) and 38 (26%). The cultures produced carcinoembryonic antigen (27.4 ng/mL), carbohydrate antigen 19-9 (210 U/mL), and carbohydrate antigen 125 (526 U/mL). The NEYS cells did not give rise to transplant tumors in nude mice, and showed no susceptibility against cisplatin (CDDP), CPT-11, carboplatin, Paclitaxel, Taxotere and 5-FU. This cell line is useful for studies on the histogenesis of carcinosarcoma and susceptibility of cancer drugs in human ovarian carcinosarcoma. The immunohistochemical and ultrastructual analysis demonstrated that NEYS cells showed epithelial and mesenchymal differentiation, and supported the metaplasis theory as the cause of carcinosarcoma.

Establishment and characterization of a cell line (IGSK-3) secreting human chorionic gonadotropin, adrenocorticotropic hormone and parathyroid hormone-related protein derived from primary poorly differentiated adenocarcinoma of the stomach.

We recently established human chorionic gonadotropin-, adrenocorticotropic hormone- and parathyroid hormone-related protein-secreting cell line derived from primary poorly differentiated adenocarcinoma of the stomach. The cell line was designated as IGSK-3. Inverted-phase contrast microscopy revealed that the IGSK-3 cells consist of two morphological subtypes. One type has visible nucleoli and clear nuclei, but nucleoli and nuclear membrane of the other type are invisible. The population-doubling time was about 43 h. An analysis of conditioned medium by IGSK-3 cells cultured for 4 days revealed the IGSK-3 cells secrete human chorionic gonadotropin-beta (0.5 ng/mL), adrenocorticotropic hormone (5.5 pg/mL), parathyroid hormone-related protein (3.4 pmol/mL) and epidermal growth factor (14.2 pg/mL). Histopathological diagnosis of the graft of IGSK-3 cells revealed that IGSK-3 cells built a poorly differentiated adenocarcinoma which resembled the original tumor. In addition, the IGSK-3 cell line was immunocytochemically positive for human chorionic gonadotropin-beta and epidermal growth factor receptor, and negative for vascular endothelial growth factor.

Use of hand-held ultrasonography to confirm the correct placement of a central venous catheter tip.

To avoid severe complications resulting from malpositioning of a central venous catheter, removal and recannulation of the catheter may be necessary, thus wasting medical equipment and increasing stress on the patient. Therefore, central venous catheters should be inserted correctly the first time. We tested whether real-time hand-held ultrasound-guided confirmation of the location of the tip of a central venous catheter inserted from the femoral vein could reduce the rate of malpositioning. Catheters were inserted using conventional methods for 65 patients, and using ultrasound guidance for 29 patients. For the latter group, when a central venous catheter was inserted, the ultrasound examiner first identified its tip located dorsal to the liver in the inferior vena cava and then fixed the catheter in position. We considered a central venous catheter to be malpositioned when its tip appeared in neither the inferior vena cava nor the right atrium-inferior vena cava junction in X-rays. Flexed or inverted catheters were also considered to be malpositioned. We compared the malpositioning rates for the ultrasound and conventional groups. Malpositioning was identified for two (6.9%) patients in the ultrasound group and 19 (29.2%) patients in the conventional group. The relative risk of ultrasound-guided versus conventional catheter insertion was 0.23 (95% confidence interval, 0.09-0.62). Our data suggest that real-time ultrasound monitoring is useful for avoiding malpositioning of central venous catheters inserted from the femoral vein.

[Clinical phenotype of a Japanese family with primary open-angle glaucoma caused by a Ala 363 Thr mutation in the MYOC gene].

BACKGROUND: Myocilin is a gene that causes primary open-angle glaucoma (POAG). We report a family whose members had an Ala 363 Thr mutation in the myocilin gene. We present the clinical phenotype of this family. CASE: The proband was a 57-year-old man diagnosed with POAG. His younger sister (50 years old) was also diagnosed with POAG. Visual field impairment did not worsen and ocular pressure decreased with eyedrop treatment. Although two of their children in their 30s had ocular hypertension, they did not have any sign of glaucomatous optic neuropathy. Genetic analysis revealed that all four family members had an Ala 363 Thr mutation in myocilin gene. CONCLUSION: Ala 363 Thr mutation was considered to be the cause of open-angle glaucoma. In this family, age at onset was comparatively high The two patients in their 30s had high intraocular pressure but no loss in visual acuity. The family members who had POAG and those who did not have POAG were not different from each other in the results of standard ocular examinations, only in age. Patients with this mutation will develop high intraocular pressure after 30 years of age and glaucomatous neuropathy after 50 years of age. When this gene mutation is detected in juvenile patients, careful follow-up and early therapy are necessary.

Myosin-Va regulates exocytosis through the submicromolar Ca2+-dependent binding of syntaxin-1A.

Myosin-Va is an actin-based processive motor that conveys intracellular cargoes. Synaptic vesicles are one of the most important cargoes for myosin-Va, but the role of mammalian myosin-Va in secretion is less clear than for its yeast homologue, Myo2p. In the current studies, we show that myosin-Va on synaptic vesicles interacts with syntaxin-1A, a t-SNARE involved in exocytosis, at or above 0.3 microM Ca2+. Interference with formation of the syntaxin-1A-myosin-Va complex reduces the exocytotic frequency in chromaffin cells. Surprisingly, the syntaxin-1A-binding site was not in the tail of myosin-Va but rather in the neck, a region that contains calmodulin-binding IQ-motifs. Furthermore, we found that syntaxin-1A binding by myosin-Va in the presence of Ca2+ depends on the release of calmodulin from the myosin-Va neck, allowing syntaxin-1A to occupy the vacant IQ-motif. Using an anti-myosin-Va neck antibody, which blocks this binding, we demonstrated that the step most important for the antibody's inhibitory activity is the late sustained phase, which is involved in supplying readily releasable vesicles. Our results demonstrate that the interaction between myosin-Va and syntaxin-1A is involved in exocytosis and suggest that the myosin-Va neck contributes not only to the large step size but also to the regulation of exocytosis by Ca2+.

Minimal residues in linker domain of syntaxin 1A required for binding affinity to Ca2+/calmodulin-dependent protein kinase II.

The linker domain is important for the conformational change syntaxin 1A, which enables it to act as a SNARE for exocytosis. We found that when applied exogenously, the linker domain is a potent inhibitor of exocytosis through inhibiting interaction between autophosphorylated CaMKII and endogenous syntaxin 1A (Ohyama et al. [2002] J. Neurosci. 22:3342-3351). To identify the simplest and the most potent inhibitor for exocytosis, we further characterized the linker domain and determined the minimal number of residues required for CaMKII binding. The minimal length of the CaMKII-binding site was 145-172 residues and a loss of G172 considerably weakened affinity for CaMKII. The basic amino acid clusters, R151 and K146, were indispensable for binding, whereas R148 was not. A comparison of the CaMKII-binding in several syntaxin isoforms revealed that the substitution of S162 attenuated CaMKII-binding activity. These results suggest that S162 is an important residue as well as the basic amino acid cluster within region 145-172 of the linker domain.

Regulation of exocytosis through Ca2+/ATP-dependent binding of autophosphorylated Ca2+/calmodulin-activated protein kinase II to syntaxin 1A.

Syntaxin 1A/HPC-1 is a key component of the exocytotic molecular machinery, namely, the soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP) receptor mechanism. Although >10 syntaxin-binding proteins have been identified, they cannot completely explain the regulation of exocytosis. Thus, novel proteins may interact with syntaxin. Because exocytosis requires both Ca2+ and ATP, we searched for Ca2+/ATP-dependent syntaxin-binding proteins from the rat brain and discovered Ca2+/calmodulin-activated protein kinase II (CaMKII)-alpha. At Ca2+ concentrations of >10(-6) m, only autophosphorylated CaMKII bound to syntaxin. Bound CaMKII was released from syntaxin by EGTA or by phosphatase, indicating that the binding is reversible. CaMKII bound to the linker domain of syntaxin, unlike any other known syntaxin-binding proteins. CaMKII-syntaxin complexes were also detected in synaptosomes by immunoprecipitation, and when reconstituted in vitro, they recruited larger amounts of synaptotagmin and SNAP-25 than syntaxin alone. The microinjected CaMKII-binding domain of syntaxin specifically affected exocytosis in chromaffin cells and in neurons. These results indicate that the Ca2+/ATP-dependent binding of CaMKII to syntaxin is an important process in the regulation of exocytosis.

Completely laparoscopic extraperigastric lymph node dissection for gastric malignancies located in the middle or lower third of the stomach.

Dissection of the extraperigastric lymph nodes is necessary in most submucosal gastric cancers. Laparoscopy-assisted gastrectomy with extraperigastric lymph node dissection via minilaparotomy has been performed, but, to our knowledge, completely laparoscopic extraperigastric lymph node dissection has never been reported. We successfully performed completely laparoscopic distal gastrectomy with extraperigastric lymph node dissection in 12 patients, of whom 11 had early gastric cancer and 1 had malignant lymphoma. This surgery is technically feasible, has an acceptable complication rate, and a curability similar to that with open surgery.