[A case of hepatic artery aneurysm ruptured into the biliary tract to be treated with hepatic artery embolization].
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Adult↗
Biomedical subjects
H Mukai
Publications and source records attributed to H Mukai.
Alpha-amylase from the hyperthermophilic archaebacterium Pyrococcus furiosus. Cloning and sequencing of the gene and expression in Escherichia coli.
A gene encoding a highly thermostable alpha-amylase from the hyperthermophilic archaebacterium Pyrococcus furiosus was cloned and expressed in Escherichia coli. The nucleotide sequence of the gene predicts a 649-amino acid protein with a calculated molecular mass of 76.3 kDa, which corresponds well with the value obtained from purified enzyme using denaturing polyacrylamide gel electrophoresis. The NH2 terminus of the deduced amino acid sequence corresponds precisely to that obtained from the purified enzyme, excluding the NH2-terminal methionine. The amylase expressed in E. coli exhibits temperature-dependent activation characteristic of of the original enzyme from P. furiosus, but has a higher apparent molecular weight which is attributed to the improper formation of the native quaternary structure. No homology was found with previously characterized promotor or termination sequences. The deduced amino acid sequence displayed strong homology to the alpha-amylase A of Dictyoglomus thermophilum, an obligately anaerobic, extremely thermophilic bacterium. Evolutionary implications of this homology are discussed.
Amino Acid Sequence↗
Isolation and characterization of SSE1 and SSE2, new members of the yeast HSP70 multigene family.
Two new members of the Saccharomyces cerevisiae heat-shock protein 70 multigene (HSP70) family were isolated from a yeast expression library using antisera made against a yeast calmodulin-binding fraction. They are designated as SSE1 and SSE2, because their predicted amino acid (aa) sequences are highly homologous to each other (76% identical), and share homology with known members of the yeast HSP70 multigene family, but their homologies (13 to 28% identity) are not high enough to place them in known subfamilies. SSE1 and SSE2 are thought to encode polypeptides of 693 aa with calculated M(r)'s of 77,408 and 77,619, respectively. The SSE1 mRNAs were moderately abundant during steady-state growth at 23 degrees C, and increased a few-fold upon upshift to 37 degrees C. SSE2 mRNAs were present at low level during steady-state growth at 23 degrees C, and greatly increased upon upshift to 37 degrees C. Disruption of SSE1 results in slow-growing cells at any temperature. No phenotypic effects of the mutation in SSE2 were detected, and the growth property of the sse1sse2 double mutant was the same as that of the sse1 single mutant.
Amino Acid Sequence↗
Exocytosis in chromaffin cells. Possible involvement of the heterotrimeric GTP-binding protein G(o).
The use of non-hydrolyzable analogues of GTP in permeabilized secretory cells suggests that guanine nucleotide-binding regulatory proteins (G proteins) may be involved in regulated exocytosis. Because GTP analogues are known to modulate both monomeric low molecular mass G proteins and heterotrimeric G proteins, we have examined the effect of mastoparan, an activator of heterotrimeric G proteins, on secretion from intact and permeabilized chromaffin cells. In intact cells, mastoparan inhibited catecholamine secretion evoked by nicotine but had no effect on release induced by other secretagogues. In permeabilized cells, mastoparan inhibited calcium-dependent secretion providing that the pores created in the plasma membrane allow the penetration of the peptide into the cytoplasm. These results indicate that mastoparan blocks the exocytotic machinery through an intracellular target protein that may not be located just beneath the plasma membrane. Accordingly, mastoparan was able to stimulate G proteins associated with purified chromaffin granule membranes, in a range of concentration and Mg2+ requirement that was similar to its inhibitory effect on secretion. Mas 17, a mastoparan analogue inactive on purified G proteins, neither modified catecholamine secretion nor stimulated chromaffin granule G proteins. The substance P-related peptide, GPAnt-2, known to antagonize the effects of mastoparan on G(o), blocked both the inhibitory effect of mastoparan on secretion and the mastoparan-stimulated GTPase activity in chromaffin granule membranes. Moreover, specific antibodies raised against the carboxyl terminus of G(o) alpha reversed in a dose-dependent manner the inhibition by mastoparan on catecholamine release and the stimulation by mastoparan of chromaffin granule-associated G proteins. These results suggest that the secretory machinery in chromaffin cells can be blocked by activating a G(o) protein. Consistent with this finding, two other known activators of heterotrimeric G proteins, aluminum fluoride and benzalkonium chloride, inhibited calcium-evoked catecholamine secretion in streptolysin O-permeabilized chromaffin cells. We conclude that an inhibitory G(o) protein, possibly located on the membrane of secretory granules, is involved in the final stages of exocytosis in chromaffin cells.
Adrenal Glands↗
Inhibitory effects of substance P analogs on the activation of GTP-binding regulatory proteins by receptors.
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Animals↗
Detection of the FK506-FKBP-calcineurin complex by a simple binding assay.
[3H]FK506-FK506-binding protein (FKBP) complex does not bind polyethyleneimine-treated glass fiber filters, on the other hand, it binds the filter when it makes a complex with calcineurin. This enabled us to develop a simple binding assay to detect the FK506-FKBP-calcineurin complex in the mixture and to estimate the amount of FKBP or calcineurin which can form the complex in the soluble extracts from rat tissues. The molar concentration of FKBP of every rat tissue is much higher than that of calcineurin, and FKBP/calcineurin molar ratio varies from 13 to 33 in various brain regions, and from 42 to 343 in peripheral tissues. These results suggest that most of the FKBP molecules have physiological roles which are not related to calcineurin, in spite of their potential ability to form the complex with FK506 and calcineurin.
Animals↗
Staging of pancreatic carcinoma by endoscopic ultrasonography.
The ability of EUS to diagnose small pancreatic cancer is well known. In this study, we present our experience with EUS in the local staging of 29 patients with pancreatic carcinoma who underwent surgery. EUS was 79, 83 and 79% accurate in determining anterior (including gastric), duodenal and retroperitoneal (vascular) invasion by the tumor. Ultrasonography (48, 39 and 55%, respectively) and CT (38, 33 and 41%, respectively) were less reliable. EUS was equal to angiography in diagnosing vascular involvement. EUS was more effective in detecting splenoportal infiltration (sensitivity 88%, specificity 78%) than arterial involvement (accuracy 50%). EUS was also less reliable in determining the N stage (66%) and in stage grouping (72%). Although EUS is superior to ultrasonography and CT in the local staging of pancreatic carcinoma, further studies must show whether improved staging criteria will lead to better results.
Endoscopy, Digestive System↗
Empathy and aggression: effects of self-disclosure and fearful appeal.
On the basis of the familiarity-empathy assumption that self-disclosure evokes empathy for the speaker, it was predicted that a victim's self-disclosure would inhibit aggression against the victim. Female Japanese subjects were asked to give electric shocks to a female victim who disclosed information about herself, was not given an opportunity to do so, or rejected disclosure. Independently of self-disclosure, another empathy arousal was introduced, that is, whether or not the victim expressed her fear of shocks before they were delivered. Consistent with our hypothesis, subjects selected less severe shocks when the victim disclosed information about herself than when she was not given an opportunity to do so or when she rejected self-disclosure. The victim's expression of fear was also very effective in reducing subjects' aggression, suggesting that drawing subjects' attention to the victim's negative emotional state evoked empathy for her and reduced their aggression.
Aggression↗
FKBP12-FK506 complex inhibits phosphatase activity of two mammalian isoforms of calcineurin irrespective of their substrates or activation mechanisms.
The interaction of calcineurin (Ca2+/calmodulin-dependent protein phosphatase) with the potent immunosuppressive agent FK506 and its 12 kDa isoform binding protein (FKBP12) was investigated. The FKBP12-FK506 complex inhibited the Ca2+/calmodulin-stimulated phosphatase activity of each of two calcineurin isoforms, which contain either the catalytic subunit A alpha or A beta (calcineurin A alpha or A beta) of bovine calcineurin. Calcineurin phosphatase activity was inhibited by the FKBP12-FK506 complex irrespective of the substrate or the enzyme activation mechanism. FK506 and FKBP-12 inhibited calcineurin in a concentration-dependent manner, and complete inhibition of the phosphatase activity appeared to require a molar excess of FKBP12-FK506 complex. Immunochemical measurements revealed tissue differences in the concentration of calcineurin, which may be of importance to the selectivity for immunosuppression of all of the biological effects. Direct binding studies with [3H]dihydro-FK506 suggest that the ratio of FKBP12-FK506 complex to calcineurin in vivo when IL2 production is inhibited is well correlated with the ratio when calcineurin phosphatase activity is inhibited in vitro. These results suggest that calcineurin is a relevant cellular target of FK506 when bound to FKBP-12.
Amino Acid Sequence↗
Molecular cloning of two additional members of the neural visinin-like Ca(2+)-binding protein gene family.
We have isolated a rat cDNA clone encoding a neural visinin-like Ca(2+)-binding protein (NVP), which we designate NVP-1. To identify additional molecular forms of NVP, a rat brain cDNA library was screened for their presence using an NVP-1 cDNA probe under low-stringency hybridization conditions. Two types of cDNA clones encoding structurally related proteins, designated NVP-2 and NVP-3, have been isolated. The deduced amino acid sequences of NVP-2 and NVP-3 are 89.0% and 68.6% identical to that of NVP-1, respectively, and contain consensus sequences for EF-hand Ca(2+)-binding sites. Northern blot analysis shows that NVP-1, NVP-2, and NVP-3 mRNAs are most highly expressed in brain and are differentially expressed in various regions of rat brain. These results suggest that NVP-2 and NVP-3 are additional members of the NVP gene family.
Amino Acid Sequence↗
Utilization of intravenously infused maltooligosaccharides in rabbits.
The utilization of intravenously infused maltotriose, maltotetraose and maltopentaose was investigated in rabbits. Rabbits were infused with isotonic solutions of each maltooligosaccharide for 2 h and the utilization was assessed by the 24-h urinary loss of carbohydrates. The utilization of these maltooligosaccharides was good (> or = 87.5%) at a rate of 1 ml/kg/h (< or = 250 mg/kg/h) and poor (< or = 36.2%) at a rate of 5 ml/kg/h (> 250 mg/kg/h). Furthermore, these maltooligosaccharides infused as 5% solution showed good utilization (> or = 86.2%) at a rate of 5 ml/kg/h (250 mg/kg/h). These results suggest the existence of a threshold dose in the utilization of intravenously infused maltooligosaccharides, and this threshold value in rabbits is estimated to be nearly 250 mg/kg/h.
Animals↗
Coronary stenosis and steal phenomenon in coronary-pulmonary fistula--assessment with stress thallium tomography after coronary angioplasty and fistulectomy.
We present a 46-year-old male with unstable angina and bilateral coronary-to-pulmonary artery fistulae in whom reversible myocardial ischemia was detected by exercise-stress thallium-201 single-photon emission computed tomography (SPECT). Coronary angiography revealed a 99% stenosis at the proximal site of the left descending coronary artery and bilateral coronary-to-pulmonary artery fistulae with a saccular aneurysm. Percutaneous transluminal coronary angioplasty abolished chest pain and electrocardiographic changes. However, definitely improved, but still present, stress-induced perfusion abnormalities were demonstrated by an exercise-stress thallium-201 SPECT study. Myocardial ischemia was the only serious complication related to the coronary fistulae, and after they were surgically resected, the reversible perfusion abnormality was no longer observed. These findings suggest that coronary-to-pulmonary artery fistulae potentiated the myocardial ischemia in patient with coronary stenosis leading to unstable angina and prolonged the presence of coronary perfusion abnormality on stress thallium scans probably through a coronary steal phenomenon.
Angina, Unstable↗
Penetrating injury of the transverse sinus by a nail-gun--case report.
A 46-year-old male presented with a penetrating injury of the transverse sinus caused by a nail-gun. Open craniotomy reflected a doughnut-shaped bone flap and the 45 mm long nail, which was fortunately only touching the edge of the sinus, successfully removed. A wide surgical exposure and careful manipulation of the embedded nail are important to avoid inadvertent injury to the venous sinus and the surrounding brain tissues during the surgical procedure.
Accidents, Occupational↗
[Endoscopic sphincterotomy for lithotripsy (EST-L) of bile duct stones].
We performed EST-L for 555 patients with choledocholithiasis between 1981 and 1992. With the aid of conventional occlusion balloons and dormia-type baskets, calculi < or = 1.5 cm was extracted with relative ease. In patients with larger stone (> 1.5 cm), the mechanical lithotripter, extracorporeal shock wave lithotripsy (ESWL) and electrohydrolic lithotripsy were used for the lithotripsy. The overall success rate was 95%. Important early and late complications from these procedures occurred in 6.9% and 9.1% of all cases respectively. This result reveal that EST-L is safe and effective therapeutic procedures for choledocholithiasis. We would recommend EST-L is adopted as an initial measure to remove common bile duct stones.
Bile Duct Diseases↗
Molecular cloning and characterization of the promoter region of the calcineurin A alpha gene.
The 5'-flanking region of the calcineurin A alpha gene was isolated from a rat genomic library. It lacked TATA and CAAT boxes but contained G+C-rich regions, and was demonstrated to function as a strong promoter in neuronal cell lines (NG108-15 mouse neuroblastoma x rat glioma hybrid cells or N1E115 mouse neuroblastoma cells), but not in nonneuronal cell lines (C6 rat glioma or L-M mouse fibroblastoid cells) in a transient chloramphenicol acetyltransferase expression assay. Deletion analysis of the 5'-flanking region revealed that the core promoter region, as well as the sequence critical for cell-type-specific-promoter function, reside within the fragment -107 to +157 with respect to the major transcription initiation site.
Amino Acid Sequence↗
[Percutaneous injection of cisplatin lipiodol suspension (CLS) in rabbit lung, aiming at intratumoral injection therapy for lung cancer].
Cisplatin lipiodol suspension (CLS: cisplatin 20 mg/ml) was percutaneously injected (cisplatin dose, 2, 4 or 6 mg/kg) in normal lungs of 10 rabbits (1.9-2.3 kg) to assess the safety and feasibility of intratumoral injection of CLS for lung cancer. Histological study revealed acute and chronic infiltrates with bronchiolitis and immature fibrosis at the injected lung tissue even at four weeks after injection. Intrathoracic leaks of CLS produced mild and focal fibrinous pleuritis. Intrabronchial leaks of CLS produced peripheral bronchiolitis with regenerative epithelia. However, no noxious parenchymal damage in the lung and surrounding tissues was noted. Neither oil embolism in brain nor renal toxicity was demonstrated. Seven of eight rabbits showed an increase in body weight. Concentration levels of plasma platinum were lower when compared with intravenous injection of cisplatin in the rabbit: highest at 30 minutes and unmeasurable one week after injection. Lipiodol accumulation in mediastinal lymph nodes was demonstrated in two of nine rabbits by X-ray examination, suggesting intralymphatic drainage of CLS. Intratumoral injection of CLS is safe even with CLS leaks in surrounding normal lung tissues and may be a potent therapy for controlling mediastinal lymph nodes metastasized from lung cancer as well as the primary tumor.
Administration, Cutaneous↗
Ca2+/calmodulin-activated protein phosphatase (PP2B) of Saccharomyces cerevisiae. PP2B activity is not essential for growth.
Protein phosphatase (PP2B) whose activity is stimulated 12-20-fold by Ca2+/calmodulin (CaM) was partially purified by CaM-Sepharose and heparin-agarose chromatographies from cell extract of the yeast Saccharomyces cerevisiae. PP2B activity was not detectable in a mutant in which two genes (CMP1 and CMP2) encoding homologs of mammalian PP2B catalytic subunit were disrupted. We have previously shown that the double gene disruption has no significant effect on the growth of yeast [1991, Mol. Gen. Genet. 227, 52-59]. The results indicated that CMP1 and CMP2 are the only genes that encode the PP2B catalytic polypeptide in S. cerevisiae, and PP2B activity is not essential for the growth of the yeast under normal conditions.
Calcium↗
G protein antagonists. A novel hydrophobic peptide competes with receptor for G protein binding.
A substance P (SP) analog, [D-Pro4,D-Trp7,9,10] SP4-11, is known to inhibit the actions of various structurally unrelated messenger molecules as well as SP. Our studies on the effects of this peptide on the regulation of purified G proteins by receptor showed that at least some of the biological effects of the peptide can be explained by the ability of the peptide to block the activation of G proteins by receptors. Here we report that a novel truncated SP-related peptide, pGlu-Gln-D-Trp-Phe-D-Trp-D-Trp-Met-NH2, inhibited the activation of G(i) or G(o) by M2 muscarinic cholinergic receptor (M2 mAChR) or of Gs by beta-adrenergic receptor in the reconstituted phospholipid vesicles, assayed by receptor-promoted GTP hydrolysis. The inhibition by the peptide was apparently reversible and competitive with respect to receptor binding to G proteins; the inhibition could be overcome by increasing the concentration of receptor in the vesicles and was not altered by changes in the concentration of G protein. The competing effects of the peptide were used to analyze the effect of agonist on receptor-G protein interaction. The concentration change of muscarinic agonist did not alter the inhibitory effects of the peptide on M2 mAChR-promoted GTPase by G(o), which is consistent with the idea that agonist increases the regulatory efficiency of the receptor but does not alter its affinity for G proteins. This new group of compounds (G protein antagonists) is a promising tool to study receptor-G protein interaction quantitatively.
Amino Acid Sequence↗