[Microgravity modulates function of osteoblast].
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Adaptor Proteins, Signal Transducing↗
Biomedical subjects
M Hirano
Publications and source records attributed to M Hirano.
Mitogen-induced up-regulation of non-smooth muscle isoform of alpha-tropomyosin in rat aortic smooth muscle cells.
Correlation between the expression of the alpha-tropomyosin isoforms and cell growth was investigated in rat aortic smooth muscle cells. The levels of exon 1a, exons 1a+2a (smooth muscle type) and exons 1a+2b (non-smooth muscle type) were determined by reverse transcription-polymerase chain reaction (RT-PCR). When the cells were cultured, the level of exons 1a+2b transiently increased while reaching a maximum at 3-5 days. When the serum-deprived confluent cells were stimulated with 3-20% serum for 1.5 h, the level of exons 1a+2b increased by about twofold. The 1-(5-isoquinolinesulphonyl)-2-methylpiperazine (H-7) but not 2-[1-(3-dimethylaminopropyl)-1H-indol-3-yl]-3-(1H-indol-3-yl)-maleimi de (GF 109203X) inhibited this up-regulation. Phorbol-12, 13-dibutyrate (PDB) mimicked the effect of serum. The DNA synthesis as determined by the incorporation of 5-bromo-2'-deoxy-uridine (BrdU) was not enhanced by the 1.5 h stimulation with serum or phorbol ester. The up-regulation of non-smooth muscle isoform of alpha-tropomyosin occurred during G(0)/G(1) transition before entering S phase. Protein phosphorylation is suggested to be involved in the up-regulation. However, the responsible kinase(s) remain to be elucidated.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
Multiple transcripts of the human Cu,Zn superoxide dismutase gene.
We have identified five alternatively spliced transcripts of the gene for human Cu,Zn superoxide dismutase (SOD1), a causative gene for autosomal dominant amyotrophic lateral sclerosis (ALS). The splice variants of wild-type or mutant SOD1 were expressed in a tissue-specific manner; therefore, their expression may be regulated to modify SOD1 function. In addition, the expression in the brain implies that variants may play a role in the nervous system, the region involved in ALS. Immunoblot study of HeLa cells transfected with two variants encoding C-terminal truncated proteins did not show the proteins of expected size. However, this observation is consistent with the previous study of C-terminal truncated mutant proteins that cause ALS, suggesting that both variant and mutant proteins may share certain properties, such as instability or insolubility in the cytosol. These findings suggest that the splice variants may contribute to a physiological function of SOD1 or to a pathological mechanism in ALS.
Alternative Splicing↗
Primary LAMP-2 deficiency causes X-linked vacuolar cardiomyopathy and myopathy (Danon disease).
"Lysosomal glycogen storage disease with normal acid maltase" which was originally described by Danon et al., is characterized clinically by cardiomyopathy, myopathy and variable mental retardation. The pathological hallmark of the disease is intracytoplasmic vacuoles containing autophagic material and glycogen in skeletal and cardiac muscle cells. Sarcolemmal proteins and basal lamina are associated with the vacuolar membranes. Here we report ten unrelated patients, including one of the patients from the original case report, who have primary deficiencies of LAMP-2, a principal lysosomal membrane protein. From these results and the finding that LAMP-2-deficient mice manifest a similar vacuolar cardioskeletal myopathy, we conclude that primary LAMP-2 deficiency is the cause of Danon disease. To our knowledge this is the first example of human cardiopathy-myopathy that is caused by mutations in a lysosomal structural protein rather than an enzymatic protein.
Antigens, CD↗
Endoscopic surgery for lateral cervical cysts. A report of three cases.
Recently, endoscopic surgery has been applied to cervical exploration. We have developed new techniques for endoscopic neck surgery, and in this paper report our experience with three patients with lateral cervical cysts. A 5- or 10-mm midline trocar for the endoscope and two 5- or 10-mm lateral trocars were inserted from the anterior chest wall and/or both axillary fossae to avoid neck scars. There were no intraoperative complications. Slight subcutaneus emphysema was present postoperatively, but it was limited to the neck and disappeared in a few days. The incisions were completely covered by the patients' undergarments. This is the first report of endoscopic lateral cervical cystectomy.
Adolescent↗
Long-term treatment with haloperidol decreases the mRNA levels of complexin I, but not complexin II, in rat prefrontal cortex, nucleus accumbens and ventral tegmental area.
The effect of long-term treatment with haloperidol on gene expression of the presynaptic protein complexins was investigated in the discrete brain regions of rats, using reverse transcription-polymerase chain reaction. Four-week-treatment with haloperidol decanoate (25 mg eq/kg) produced a significant decrease in the mRNA levels of complexin I in the medial prefrontal cortex, nucleus accumbens and ventral tegmental area, but not in the striatum and substantia nigra. No significant changes in complexin II mRNA levels were observed in any brain region examined here. The reduced expression of complexin I may be associated with the haloperidol-induced depolarization block of mesocorticolimbic dopamine neurons.
Adaptor Proteins, Vesicular Transport↗
Molecular and genetic characterization of sarcospan: insights into sarcoglycan-sarcospan interactions.
Autosomal recessive limb girdle muscular dystrophies 2C-2F represent a family of diseases caused by primary mutations in the sarcoglycan genes. We show that sarcospan, a novel tetraspan-like protein, is also lost in patients with either a complete or partial loss of the sarcoglycans. In particular, sarcospan was absent in a gamma-sarcoglycanopathy patient with normal levels of alpha-, beta- and delta-sarcoglycan. Thus, it is likely that assembly of the complete, tetrameric sarcoglycan complex is a prerequisite for membrane targeting and localization of sarcospan. Based on our findings that sarcospan is integrally associated with the sarcoglycans, we screened >50 autosomal recessive muscular dystrophy cases for mutations in sarcospan. Although we identified three intragenic polymorphisms, we did not find any cases of muscular dystrophy associated with primary mutations in the sarcospan gene. Finally, we have identified an important case of limb girdle muscular dystrophy and cardiomyopathy with normal expression of sarcospan. This patient has a primary mutation in the gamma-sarcoglycan gene, which causes premature truncation of gamma-sarcoglycan without affecting assembly of the mutant gamma-sarcoglycan into a complex with alpha-, beta- and delta-sarcoglycan and sarcospan. This is the first demonstration that membrane expression of a mutant sarcoglycan-sarcospan complex is insufficient in preventing muscular dystrophy and cardiomyopathy and that the C-terminus of gamma-sarcoglycan is critical for the functioning of the entire sarcoglycan-sarcospan complex. These findings are important as they contribute to a greater understanding of the structural determinants required for proper sarcoglycan-sarcospan expression and function.
Adult↗
Minimal requirements for the nuclear localization of p27(Kip1), a cyclin-dependent kinase inhibitor.
p27(Kip1) is a cyclin-dependent kinase inhibitor, and its nuclear localization is a prerequisite for it to function as a cell cycle regulator. In the present study, the minimal requirement for the nuclear localization signal (NLS) of p27(Kip1) was determined by analyzing the localization of various mutants of p27(Kip1) tagged with green fluorescent protein (GFP) in HeLa cells and porcine aortic endothelial cells. Wild-type p27(Kip1) exclusively localized into nucleus, while GFP alone localized in both cytosol and nucleus. A comparison of various truncation mutants revealed residues 153-166 to be the minimal region necessary for nuclear localization. However, a fusion of this region to GFP showed cytoplasmic retention in addition to nuclear localization, thus suggesting that some extension flanking this region is required to achieve a full function of NLS. The site-directed mutation of the full-length p27(Kip1) therefore showed that four basic residues (K153, R154, K165, R166), especially R166, play a critical role in the nuclear localization of p27(Kip1).
Amino Acid Sequence↗
Dissociation between the Ca(2+) signal and tube formation induced by vascular endothelial growth factor in bovine aortic endothelial cells.
The correlation between the intracellular Ca(2+) signal and the tube formation in collagen gels induced by vascular endothelial cell growth factor (VEGF) was investigated using cultured bovine aortic endothelial cells. The VEGF-induced sustained elevation of cytosolic Ca(2+) concentration ([Ca(2+)](i)) was similarly inhibited by 10 microM 1-¿beta-[3-(4-methoxyphenyl)propyl]-4-methoxyphenethyl¿-1H-imidazole hydrochloride (SKF 96365) and 10 microM troglitazone. However, 10 microM diltiazem had no effect. The basal tube formation obtained with 1% serum was augmented twofold by 100 ng/ml VEGF. SKF 96365 (0. 1-10 microM) inhibited the VEGF-induced and basal tube formation, while 10 microM troglitazone or 10 microM diltiazem had no effect. The proliferation of endothelial cells was markedly inhibited by SKF 96365 but only slightly by troglitazone and diltiazem. The inhibition of tube formation by three Ca(2+) entry blockers thus correlated with the inhibition of cell proliferation. The [Ca(2+)](i) elevation is thus not a prerequisite for VEGF to induce tube formation.
Animals↗
Mmh/Ogg1 gene inactivation results in accumulation of 8-hydroxyguanine in mice.
The major mutagenic base lesion in DNA caused by exposure to reactive oxygen species is 8-hydroxyguanine or 7, 8-dihydro-8-oxoguanine (8-OH-G). Products of the human MMH/OGG1 gene are known to catalyze in vitro the reactions repairing this DNA lesion. To analyze the function of Mmh in vivo, we generated a mouse line carrying a mutant Mmh allele by targeted gene disruption. Mmh homozygous mutant mice were found to have a physically normal appearance, but to have lost nicking activity in liver extracts for substrate DNA containing 8-OH-G, exhibiting a 3-fold increased accumulation of this adduct at 9 weeks of age compared with wild-type or heterozygous mice. Further elevation to 7-fold was observed in 14-week-old animals. Substantial increase of spontaneous mutation frequencies was clearly identified in Mmh mutant mice bearing transgenic gpt genes. These results indicate that exposure of DNA to endogenous oxidative species continuously produces the mutagenic adduct 8-OH-G in mice, and Mmh plays an essential role in repair of this DNA damage.
Animals↗
[Laparoscopic radical nephrectomy for renal cell carcinomas; report on two initial cases].
We recently performed a laparoscopic radical nephrectomy (LRN) on two patients with a renal cell carcinoma. Case 1, a 72-year-old man, was diagnosed as having a renal cell carcinoma 2.5 cm in diameter in the right kidney, and also a submucosal tumor of the cecum. LRN and laparoscopically assisted ileocecal resection were performed using a transperitoneal approach on September 28, 1999. Total operation time and blood loss during the operation were 308 minutes and 320 ml, respectively. The operation time needed for LRN, which was calculated as the total operation time minus the time spent on ileocecal resection, was 199 minutes. There were no complications after surgery, and the patient was recommended for discharge on the 7th postoperative day, but was actually discharged on the 10th postoperative day. Case 2, an 81-year-old man, was diagnosed as having a renal cell carcinoma 3.0 cm in diameter in the right kidney. He had been undergone a total gastrectomy for a gastric carcinoma at age 77, and a sigmoidectomy for a sigmoid colon carcinoma at age 79. A transperitoneal approach was applied for LRN to detect any recurrence of previous carcinomas on September 30, 1999. During adhesiolytic procedures, the colon was injured due to an inappropriate maneuver of the grasping forceps. A small laparotomy (5 cm) was required for repair of the colon. The total operation time and blood loss during surgery were 370 minutes and 850 ml. The operation time calculated from the video of LRN was 274 minutes. Two additional surgical procedures were required in this case. The first was for a postoperative intraperitoneal hemorrhage due to the hemoclip dropping out of the small vein. The second was for hemorrhage in the abdominal wall. Fortunately, the clinical course after surgery was good and the patient was discharged on the 8th postoperative day. There were no complications in case 1. Omitting ileocecal resection was considered to speed up oral intake, leading to earlier discharge. However, major complications occurred in case 2. It is important to clarify the cause of postoperative hemorrhage by careful observation of the video recording, in order to suggest safer procedures in laparoscopic surgery. Although these are only two LRN experiences, we are convinced that LRN can improve postoperative QOL (Quality of life) and is an acceptable alternative for the treatment of renal cell carcinomas.
Aged↗
[The C tube in biliary surgery--its development and clinical application].
BACKGROUND: The T tube procedure for bile drainage after biliary surgery has been used all over the world for more than 90 years. However, this method has serious drawbacks: a high complication ratio and a need for long-term hospitalization. Therefore other bile drainage methods including PTGBD, PTBD and ENBD have been developed, but none has so far been able to replace T tube. We have developed a new technique for bile drainage using the C tube (cystic duct tube), which is a slender tube (6Fr. polyvinyl) inserted via the cystic duct into the common bile duct (CBD). We have used C tube in more than 400 cases over the last 20 years: for open surgery during the first 10 years, and for laparoscopic surgery in the last 10 years. Here we describe the history of improvements in the C tube method and the techniques of C tube application in biliary surgery. Elastic surgical suture has been used to fix the C tube to the cystic duct, which successfully prevented bile leakage from the ductal stump after withdrawal of the tube. C tube is not only used for postoperative bile drainage but also for the management of remnant stones. The purpose of this study is to assess the safety and benefits of the C tube procedure. METHODS: I: From 1980 to 1998, 335 cholecystectomized cases which had undergone the C tube procedure were examined for complications resulting from C tube placement. II: We analyzed 134 patients with choledocholithiasis: 34 patients had been treated using C tube drainage, and 100 patients had been treated with the T tube procedure after undergoing CBD exploration. The main outcome criteria were: the frequency of post-operative complications, quantity of bile drainage, drainage period, and length of post-operative hospital stay. III: Between 1990 and 1999, 131 patients (15.2%) of a total of 860 laparoscopically cholecystectomized patients with gallstones underwent C tube treatment. We assessed the usefulness of the C tube procedure for the detection and management of remnant stones. RESULTS: I: There were no major complications (bile-leakage, CBD stenosis, etc.) in 335 cases which underwent the C tube procedure. Minor complications related to C tube were: spontaneous withdrawal of the tube in 5 cases, movement of the tube tip in 17 cases, and difficulties during tube removal in 32 cases which included slight resistance. Two cases had liver dysfunction (GOT 705 IU/l and 488 IU/l), although this was easily normalized after withdrawal of the tube tip from the duodenal papillae into the CBD. II: The frequency of complications in patients who underwent the C tube procedure was zero, whilst in the T tube group the major complication rate was 3% and the minor complication rate was 21%. The quantity of bile drainage was 283.6 +/- 22.9 ml/day in the C tube group compared with 302.7 +/- 10.3 ml/day in the T tube group, showing no significant difference. The drainage period (5.9 +/- 0.6 days) in the C tube group was significantly shorter than in the T tube group (27.7 +/- 0.9 days). Hospital stays (11.6 +/- 0.6 days) in the C tube group were significantly shorter than in the T tube group (45.0 +/- 1.5 days). III: Remnant CBD stones were detected by postoperative cholangiography via the C tube in 28 (21.4%) of the C tube replacement cases and in 3.3% of all the laparoscopically cholecystectomized patients. Seventeen patients with remnant stones were managed using glyceryl trinitrate CBD perfusion-induced relaxation of the sphincter of Oddi. The remaining patients were managed with endoscopic papillary balloon dilatation (EPBD) and/or endoscopic sphincterotomy (EST) without reoperation. We also have described other applications of the C tube procedure for the evaluation of sphincter of Oddi motility as an indication for EST, for bile drainage in liver resection, in the treatment of liver injuries, and for duodenal decompression after duodenal surgery. Finally we have mentioned the possibility of C tube application in the management of obstructive jaundice and bile drainage in liver transplantation surgery. CONCLUSION: The C tube method in biliary surgery is safe and useful in comparison with the T tube method. We are strongly convinced that the T tube will be completely replaced by the C tube.
Aged↗
Chronic fentanyl treatments induce the up-regulation of mu opioid receptor mRNA in rat pheochromocytoma cells.
Chronic activation of adenylate cyclase-cAMP-cAMP-dependent protein kinase (PKA) systems by administration of opioid receptor agonists has been considered as one of the mechanisms of opioid tolerance and dependence. Although analysis of the micro opioid receptor (MOR) gene suggests that cAMP-related signal transduction systems regulate the expression of this gene, which transcription factors affect the MOR gene expression in brain and neural cells has not been clarified. This study deals with the effects of fentanyl on MOR mRNA levels in the rat pheochromocytoma cell line (PC12 cells). PC12 cells were cultured in medium with clinically relevant concentrations of fentanyl. The quantitative reverse transcription and polymerase chain reaction (RT-PCR) method was used for determination of MOR mRNA. Treatment of PC12 cells with fentanyl induced the MOR mRNA up-regulation in a concentration- and time-dependent manner. A cAMP analogue also up-regulated MOR mRNA. The intracellular cAMP level increased after fentanyl treatment. A PKA inhibitor blocked the MOR mRNA up-regulation by fentanyl and the cAMP analogue. Expression of a dominant inhibitory Ras also inhibited the MOR mRNA up-regulation. Fentanyl-induced up-regulation of MOR mRNA via activation of cAMP signaling may be important in compensating for the MOR reduction during long-term treatment of PC12 cells with fentanyl. The present study could be relevant to understanding the molecular mechanisms of opioids in a state of drug tolerance or dependence, and in patients under anesthesia or being treated for pain.
Analgesics, Opioid↗
Sensory innervation of the pharynx and larynx.
To shed light on supraesophageal complications of reflux disease, sensory innervation--particularly, distinct distribution, area, and density of sensory fibers--of the feline pharyngolaryngeal mucosa was reported. The investigations were performed by means of histochemistry (tracer techniques) and immunohistochemistry. The pharyngeal mucosa from the Eustachian cushion to the middle level of aryepiglottic fold, except the laryngeal surface of epiglottis, was supplied by the glossopharyngeal sensory fibers, whereas the laryngeal sensory fibers innervated between the apex of epiglottis and the level of the first tracheal ring in the larynx and between the middle level of aryepiglottic fold and the caudal end of piriform sinus in the pharynx. Most areas of the mucosa, except the subglottis, had unilateral innervation. The subglottis, including the caudal aspect of vocal fold and the posterior glottis, had bilateral supply with ipsilateral predominance. The density of sensory fibers in the vestibule of larynx involving the posterolateral aspect of arytenoid eminence was much heavier than the other parts. Sensory nerve fibers around the caudal pole of palatine tonsil, and in the root of tongue and the hypopharyngeal wall also were dense. Regional distribution and density of substance P and calcitonin gene-related peptide immunoreactive fibers showed almost the same pattern as did the sensory fibers.
Animals↗
Effect of atypical antipsychotics on phencyclidine-induced expression of arc in rat brain.
The effect of atypical antipsychotics on the immediate-early gene, arc (activity-regulated cytoskeleton-associated gene), expression was investigated in phencyclidine (PCP)-treated rats using RT-PCR. Administration of PCP (10 mg/kg) increased arc mRNA levels in the prefrontal cortex, nucleus accumbens and posterior cingulate cortex. Pretreatment with clozapine (20 mg/kg), olanzapine (10 mg/kg) and risperidone (2 mg/kg), but not haloperidol (2 mg/kg), prevented PCP-induced arc expression in the prefrontal cortex and nucleus accumbens. Pretreatment of haloperidol increased the striatal arc mRNA levels. Clozapine, olanzapine and haloperidol inhibited the PCP-induced arc expression in the posterior cingulate cortex. These results suggest that the effects of antipsychotic drugs on PCP-induced arc expression in the prefrontal cortex and nucleus accumbens are useful for distinguishing atypical antipsychotic properties of the drugs.
Animals↗
Oxygen-related intrinsic defects in glassy SiO2: interstitial ozone molecules
Interstitial O3 molecules in 7.9 eV photon-irradiated silica are identified. Their optical absorption band at 4.8 eV nearly coincides with the 4.8 eV band of nonbridging oxygen hole centers. The O3-related band is distinguished by a smaller halfwidth (0.84 vs 1. 05 eV), by susceptibility to ultraviolet bleaching, by lack of correlation to the 1.9 eV luminescence band, and by rise of a singlet O2 luminescence band at 0.974 eV during photobleaching. This identification solves a long controversy on the nature of optical bands in silica and gives a tool for studying the mobility of atomic oxygen in SiO2.
Journal Article↗
Analysis of mtDNA deletions in muscle by in situ hybridization.
We compared the distribution of deleted mitochondrial DNA (Delta-mtDNA) in skeletal muscle of a patient with autosomal recessive (AR) and another with autosomal dominant (AD) progressive external ophthalmoplegia (PEO) by in situ hybridization (ISH). The patients studied had similar numbers of fibers deficient in cytochrome c oxidase (COX) activity (13.6% and 12.8%) and fibers with mitochondrial proliferation (5.5% and 5.3%). ISH suggested that each COX-deficient fiber contained a single species of Delta-mtDNA. Most deletions ablated the region between the genes encoding adenosine triphosphate (ATP) synthase subunit 8 and cytochrome b. Fibers that appeared to be depleted of mtDNA were also present. We conclude that muscle from patients with autosomally inherited PEO contains not only Delta-mtDNA but also focal depletion of mtDNA and that the distribution of these mtDNA defects appears to be similar. These changes most likely represent the common consequence of whatever genetic factors are responsible for the generation of Delta-mtDNA.
Adult↗
Invagination induced by a long intestinal tube: report of a case.
Invagination induced by a long intestinal tube is rarely encountered. We report herein one such case of a 62-year-old man who was successfully treated by laparoscopically reducing the invagination, then performing partial resection of the small intestine.
Humans↗