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Biomedical subjects

M Yonekura

Publications and source records attributed to M Yonekura.

At least 19 recordsLinked to original sources
PubMed2005

Treatment of unruptured cerebral aneurysms; a multi-center study at Japanese national hospitals.

The treatment and natural course of unruptured cerebral aneurysms were analyzed in 615 patients with 712 unruptured cerebral aneurysms registered from seven Japanese national hospitals and Zurich University hospital. For 209 aneurysms in 181 cases, the natural course of the aneurysms was observed without surgical treatment. During the follow-up period of 3,862 months (321.8 years), 11 of these aneurysms ruptured giving a rupture rate of 3.42%/year. Five of these 11 aneurysms were less than 10 mm in diameter. Seventeen aneurysms of these 209 untreated aneurysms had blebs. Seven of these 17 aneurysms ruptured yielding the high rupture rate of 28.3%/year. The likelihood of unruptured cerebral aneurysms to rupture was not exceedingly low even when the aneurysms were smaller than 10 mm. Since the risk of rupture and morbidity in relation to surgical treatment cannot be predicted by size alone, the morphology, especially the presence of blebs, should be considered when treating unruptured cerebral aneurysms. In 434 patients, 503 cerebral aneurysms were treated surgically either by craniotomy in 472 aneurysms or endovascular coil embolization in 31 aneurysms. Surgical outcome was influenced by the presence of concurrent diseases, patient age, size and location of the aneurysms. Complications after surgical treatment of 128 incidentally found aneurysms were reported in four cases; three cases of hemiparesis and one case showing disturbance of higher brain function, with a morbidity rate of 3.1%. These results suggest that surgical treatment may be acceptable in cases of incidentally found cerebral aneurysms, especially when blebs are present.

Adult↗
PubMed2005

Surgical treatment of unruptured cerebral aneurysms in the elderly.

We retrospectively analyzed the prevalence and surgical outcomes of unruptured cerebral aneurysms in the elderly for the past five years. Between 1998 and 2002, we collected data from 575 subjects with unruptured aneurysms who had no history of subarachnoid hemorrhage (SAH). One hundred and eighty-two of these patients (31.7%) were aged > or = 70 years and they had 233 aneurysms. The proportion of older patients among all subjects increased significantly from 21.4% in 1998 to 40.3% in 2002. Unruptured aneurysms found in the elderly had a predominance of female, higher frequency of multiple aneurysms, and lower frequency of anterior communicating artery aneurysms when compared with those in the younger patients. The majority of intradural aneurysms detected in the elderly were less than 10 mm in diameter (84.8%). One hundred and eleven out of 224 intradural aneurysms in the elderly were treated (49.6%); most aneurysms were directly clipped, while only 13 aneurysms including six basilar artery aneurysms were coiled endovascularly. Among the 83 elderly subjects who underwent direct surgery, perioperative complication appeared in seven subjects (morbidity 8.4%, mortality 1.2%). No SAH occurred postoperatively and conservatively during 1-5 years of follow-up. Since the rupture rate of small unruptured aneurysms without SAH history is reported to be low, surgical indication should be considered with care particularly in the elderly.

Aged↗
PubMed2002

Treatment of unruptured cerebral aneurysms--a multi-center study of Japanese national hospitals.

The treatment and natural course of unruptured cerebral aneurysms were analyzed in 427 cases of unruptured cerebral aneurysm registered at five Japanese national hospitals. Of these cerebral aneurysms 295 were treated by craniotomy, and 22 with endovascular coil embolization. Neurological deterioration after treatment occurred in 31 (9.8%) of the 295 craniotomies and 3 (13.6%) of the 22 endovascular treatments. There was no subarachnoid hemorrhage (SAH) reported after the craniotomies whereas one case of SAH was reported after endovascular treatment. For 145 aneurysms in 110 cases, the natural course of the aneurysms was observed without surgical treatment. During the follow up period of in total 2,610 months (217.5 years), seven of these aneurysms ruptured, resulting in a rupture rate of 3.2%/year. Three of these seven aneurysms were less than 10 mm in diameter. The likelihood of an unruptured cerebral aneurysm to rupture was not exceedingly low. Since the risk of rupture and the morbidity related to surgical treatment cannot be predicted by size alone, the morphology, location and condition of the patients should be considered when treating unruptured cerebral aneurysms.

Adult↗
PubMed2002

Importance of prospective studies for deciding on a therapeutic guideline for unruptured cerebral aneurysm.

(1) In a town of 100,000 population, a 2% incidence rate of unruptured cerebral aneurysm means 2,000 patients. (2) In a town of 100,000 population, the annual occurrence of subarachnoid hemorrhage is 20. (3) The turnover of patients with unruptured cerebral aneurysm is for the 50-year cycle of patients at age from 30 to 80. On the basis of these data, in a town of 100,000 population the number of unruptured cerebral aneurysm cases and of subarachnoid hemorrhage cases occurring in 50 years are 2,000 and 1,000, respectively. In total 3,000 patients with unruptured and ruptured cerebral aneurysm, the distribution of these patients for different sizes of aneurysm can be estimated. We examined the rupture rate for each size of aneurysm. And we found that some of the aneurysm smaller than 10 mm in size rupture soon after their formation and that some of aneurysm of size remain unchanged.

Adult↗
PubMed2002

Trends in subarachnoid haemorrhage in elderly persons from Nagasaki, Japan: analysis of the Nagasaki SAH Data Bank for cerebral aneurysm, 1989-1998.

BACKGROUND: Many industrialized countries are facing a volumetric growth of the senior population. We studied the trends in the incidence and outcome of subarachnoid haemorrhage (SAH) in patients aged >or=70 years. METHOD: We retrospectively reviewed the cases of 1030 patients registered in the Nagasaki SAH Data Bank from 1989 to 1993 and 1274 patients registered from 1994 to 1998. FINDINGS: The annual age-adjusted incidence of SAH per 100,000 increased only in women, from 15.4 in the 1989-1993 period to 19.7 in the 1994-1998 period. The average annual incidence of SAH per 100,000 women in the elderly aged >or=70 years increased significantly from 44.3 in the first period to 58.2 in the second period. In patients aged >or=70 years, the proportion of high-grade SAH (Hunt & Kosnik Grade IV and V) significantly increased from 27.2% in the first 5 years to 38.2% in the second 5 years. In patients aged<70 years, it increased slightly from 23.4% to 26.7%. The rate of favorable outcomes significantly fell from 43.9% (first period) to 30.9% (second period) in patients aged >or=70 years but was stable in patients aged<70 years. INTERPRETATION: Although the incidence of elderly patients with SAH in our study is compatible with or higher than that of other reports, we believe that elderly patients (especially women) with high-grade SAH may not have all been identified. When we discuss the management of ruptured and unruptured aneurysms in the elderly, we should bear these trends of SAH in mind.

Aged↗
PubMed2001

High-resolution two-dimensional electrophoresis separation of proteins from metal-stressed rice (Oryza sativa L.) leaves: drastic reductions/fragmentation of ribulose-1,5-bisphosphate carboxylase/oxygenase and induction of stress-related proteins.

Employing high-resolution two-dimensional electrophoresis (2-DE), we studied changes in the rice leaf protein patterns, in response to applied heavy and alkaline metals, important environmental pollutants in our surroundings. Drastic changes in 2-DE protein patterns after treatment with copper, cadmium, and mercury, over control were found, including changes in the morphology of the leaf segments. Changes in the major leaf photosynthetic protein, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO, both suppression and fragmentation), and induction of proteins are reported. A total of 33 proteins, which were highly reproducible in repeated experiments, were visually identified as changed over the control, and taken for N-terminal or internal amino acid sequencing. Among these, nine proteins were N-terminally blocked, and six proteins could not be sequenced. Most of the proteins showed homology to RuBisCO protein, and some to defense/stress-related proteins, like the pathogenesis related class 5 protein (OsPR5), the probenazole-inducible protein (referred to as the OsPR10), superoxide dismutase, and the oxygen evolving protein. Results presented here strongly indicate a highly specific action of some of these metals in disturbing the photosynthetic machinery, as evidenced by prominent reductions/fragmentation of the major photosynthetic protein, RuBisCO, and resulting in stress.

Electrophoresis, Gel, Two-Dimensional↗
PubMed2001

Storage-dependent degradation of 57-kDa protein in royal jelly: a possible marker for freshness.

In order to find a marker for freshness of royal jelly (RJ), the composition change of RJ during storage was investigated. The contents of 10-hydroxy-2-decenoic acid, a bioactive component of RJ, and several vitamins did not change during storage at 40 degrees C for 7 days. However, a specific protein, designated royal jelly protein-1 (RJP-1), was gradually degraded during storage under various conditions (from 4 degrees C to 50 degrees C for up to 7 days). The specific degradation of RJP-1 was proportional to storage temperature and storage period. RJP-1 was purified to homogeneity and characterized as a monomeric glycoprotein with a molecular mass of 57 kDa. These results suggest that 57-kDa protein in RJ can be used as a marker for freshness of RJ, reflecting the conditions under which RJ has been stored.

Amino Acid Sequence↗
PubMed2001

[Ictal semiology in patients with medial temporal lobe epilepsy: value in lateralizing the seizure focus].

We have evaluated useful lateralizing signs in 28 patients with medial temporal lobe epilepsy who were seizure-free after anterior temporal lobectomy by reviewing videotapes during video-EEG monitoring. The most frequent types of aura were epigastric sensation and psychic symptom in 8, respectively, both of which did not predict lateralization of the focus. Of the motor signs, early head deviation and unilateral upper extremity automatism predicted an ipsilateral focus in 72 and 80%, respectively. On the other hand, late head deviation(< 15 seconds before secondarily generalized seizure) and unilateral upper extremity dystonic posturing predicted a contralateral focus in 80 and 100%, respectively. Twelve of the patients displayed oroalimentary automatism which did not predict focus lateralization. Three patients with ictal speech demonstrated a seizure focus contralateral to their language-dominant hemisphere. In medial temporal lobe epilepsy, several clinical seizure manifestations such as: early and late head deviation, unilateral upper extremity automatism and dystonic posturing were not a little noted and provided additional information as to the side of seizure origin.

Adolescent↗
PubMed2001

[Clinical analysis of the mechanism of oculomotor nerve palsy caused by unruptured internal carotid artery posterior communicating artery aneurysm].

We analyzed the clinical course of eight female patients of oculomotor nerve palsy due to unruptured internal artery posterior (IC-PC) communicating artery aneurysm in order to speculate on the mechanism of aneurysmal rupture. Seven of the eight patients had preceding headache or ophthalmalgia, three of them deteriorated oculomotor nerve palsy and one showed worsening of ophthalmalgia. These deteriorations occurred between three to seven days after the first clinical symptom appeared. Neck clipping of aneurysm was performed for all eight patients. These aneurysms were profiled except for one patient whose aneurysm ruptured before operation. None of these seven patients had subarachnoid hemorrhage in the operative field. The patients who showed clinical deterioration had fragile aneurysm wall, wall with bleb, and one aneurysm showed minor blood leakage during operative manipulation. In the four patients who did not show clinical deterioration, aneurysm attached oculomotor nerve, these aneurysm walls were arteriosclerotic and we could not find the fragile portion during operation. Repeated minor bleeding near the oculomotor nerve or direct aneurysmal compression are the main causes of oculomotor nerve palsy with unruptured IC-PC aneurysm. Adhesion or stimulation of aneurysm on the upper border of cavernous sinus cause the headache or ophthalmalgia and these deteriorations are thought to occur gradually. However, these deteriorations occur more rapidly than ever thought and reflect acute aneurysmal growth and its direct affect on the oculomotor nerve. IC-PC aneurysm is the only aneurysm we can observe its aneurysmal growth by its unique clinical presentation. From this study, we conclude that the deterioration of oculomotor nerve palsy, preceding headache or ophthalmalgia reflects rapid growth of unruptured IC-PC aneurysm. We neurosurgeons consider it to be an urgent rupture period and should introduce surgical management to prevent its rupture and the devastating consequence of subarachnoid hemorrhage.

Aged↗
PubMed2000

Naringenin 7-O-methyltransferase involved in the biosynthesis of the flavanone phytoalexin sakuranetin from rice (Oryza sativa L.).

An inducible S-adenosyl-L-methionine:naringenin 7-O-methyltransferase (NOMT) catalyzing the methylation of naringenin to sakuranetin, a major rice phytoalexin was purified approximately 985-fold from ultraviolet (UV)-irradiated rice leaves. The enzyme is not found in healthy tissues and was purified to a nearly homogeneous preparation in one step using adenosine-agarose affinity chromatography, with 1 g rice leaves (UV-irradiated) as starting material. Gel filtration chromatography resulted in an almost pure enzyme, as evidenced by a major band migrating to a position corresponding to a molecular mass of approximately 41 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The purified NOMT was strongly inhibited by Mn(2+), Ni(2+), Cu(2+), Zn(2+), Hg(2+), and Cd(2+), and to a low degree by Co(2+), Mg(2+), Ba(2+), Ca(2+) and ethylenediamine tetraacetic acid. The amino acid sequence of a NOMT cyanogen bromide (CNBr)-cleavage peptide was highly homologous to that of a caffeic acid 3-O-methyltransferase from maize, and about 70% of the amino acid sequence was obtained after sequencing the peptides generated by CNBr and/or formic acid hydrolysis. NOMT was also shown to be induced in a time-dependent manner, and purified from rice leaves treated with jasmonic acid and copper chloride.

Journal Article↗
PubMed2000

[Staged total callosotomy for medically intractable seizures].

For the treatment of intractable generalized epilepsies, two-staged total callosotomy was performed in five patients. In all patients, preceded anterior callosotomy failed to obtain satisfactory seizure control. All patients showed mental retardation with various degrees. Mean age at the first operation was 10.2 years and 4 patients were operated in their childhood. All patients showed various types of seizures; drop attack (DA) in 3 patients, tonic seizure (TS) in 2, myoclonus (MY) in 2, complex partial seizure (CPS) in 2, atypical absence (AA) in 1, and head drop (HD) in 2. After anterior callosotomy, complete cessation of CPS and 50-80% reduction of DA was obtained in one, respectively. However, only less than 50% reduction of seizures was obtained in other types of seizures. Two years after anterior callosotomy, posterior portion of the corpus callosum was divided. After staged total callosotomy, complete cessation of DA was obtained in all patients and 80-100% reduction of AA was obtained in one patient. One adult patient showed the disconnection syndrome which did not affect activities of his daily life. Our study revealed the efficacy of posterior callosotomy in DA patients with unsatisfactory results after anterior callosotomy. This strategy should be considered especially in childhood cases, since obvious complication was not observed in such cases.

Adolescent↗
PubMed1999

Separation of proteins from stressed rice (Oryza sativa L.) leaf tissues by two-dimensional polyacrylamide gel electrophoresis: induction of pathogenesis-related and cellular protectant proteins by jasmonic acid, UV irradiation and copper chloride.

We have used three kinds of stresses, including the signaling compound jasmonic acid, an environmental stressor, UV irradiation, and a heavy metal salt copper chloride, to study changes in the protein patterns in rice (Oryza sativa L.) leaf tissues using two-dimensional polyacrylamide gel electrophoresis. However, instead of using lysis buffer containing urea (O'Farrell, J. Biol. Chem. 1975, 250, 4007-4021) for extraction of proteins from rice seedling tissues, we used Tris-HCl buffer (commonly used for extraction of proteins for separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) for extraction of proteins and resolved these extracted proteins by the usual method of O'Farrell. Furthermore, the induction of a large number of proteins was clearly observed over controls. No spots corresponding to these induced proteins were found in the control experiment, indicating qualitative changes in protein patterns after various stress treatments. A total of 12 out of 13 proteins could be N-terminally sequenced from jasmonic acid-treated rice leaf tissues, and one protein was sequenced from UV-irradiated leaf tissues. These proteins showed high homology to pathogenesis-related (thaumatin-like protein, a PR5 class protein; a beta-1,3-glucanase precursor; an intracellular PR protein encoded by PBZ1 gene, and an antifungal protein) and cellular protectant (glutathione transferase, EC 2.5.1.18; and ascorbate peroxidase) proteins, from plants, including rice. Results presented here suggest a role for jasmonic acid in the self-defense mechanisms of rice plants.

Amino Acid Sequence↗
PubMed1999

Purification and some chemical properties of 30 kDa Ginkgo biloba glycoprotein, which reacts with antiserum against beta 1-->2 xylose-containing N-glycans.

From the seeds of Ginkgo biloba, a glycoprotein, which is a major component that reacts with an antiserum against beta 1-->2 xylose-containing N-glycans, has been purified and characterized. The N-terminal amino acid sequence of the purified glycoprotein was H-K-A-N-X-V-T-V-A-F-V-M-T-Q-H-L-L-F-G-Q-. The molecular mass was estimated to be 17 kDa and 16 kDa by SDS-PAGE under reducing conditions, however, the molecular mass of this glycoprotein in the native state was 30,762 by MALDI-TOF MS, suggesting that this glycoprotein consists of two subunits; one is glycosylated and the other is not. The structure of N-glycan linked to this glycoprotein (designated 30 kDa GBGP) was identified as Man3Fuc1Xyl1GlcNAc2, which is the predominant N-glycan linked to the storage glycoproteins in the same seeds (Kimura, Y et al. (1998) Biosci. Biotechnol. Biochem. 62, 253-261). From the peptic digest of the carboxymethylated glycosylated subunit, one glycopeptide was purified by RP-HPLC and the amino acid sequence was identified as H-K-A-N-N(Man3Fuc1Xyl1Glc-NAc2)-V-T-V-A-F, which corresponded to the N-terminal amino acid sequence.

Amino Acid Sequence↗
PubMed1998

Malonate decarboxylase of Pseudomonas putida is composed of five subunits.

Two different forms of malonate decarboxylase were purified from Pseudomonas putida. The active form was composed of the five different subunits alpha (60 kDa), beta (33 kDa), gamma (28 kDa), delta (13 kDa), and epsilon (30 kDa) and the inactive form was composed of the four subunits lacking the epsilon subunit. The former catalyzed the decarboxylation of malonate to acetate, but the latter could not, although it retained both activities of acetyl-CoA:malonate CoA transferase and malonyl-CoA decarboxylase. The delta subunit of the active form was acylated by the incubation with [2-14C]malonyl-CoA, but the delta subunit of the inactive form was not labeled. From the above results and the N-terminal amino acid sequence analysis, it was concluded that the epsilon subunit was an essential subunit to function as malonyl-CoA:ACP transacylase, which was an indispensable component of the enzyme for the cyclic decarboxylation of malonate.

Acyl-Carrier Protein S-Malonyltransferase↗
PubMed1998

Combination of serine protease inhibitor FUT-175 and thromboxane synthetase inhibitor OKY-046 decreases cerebral vasospasm in patients with subarachnoid hemorrhage.

The preventive effect of the serine protease inhibitor FUT-175 (nafamostat mesilate), a potent inhibitor of the complement system, against vasospasm was evaluated in 34 high risk patients with thick and diffuse subarachnoid hemorrhage (SAH) demonstrated by computed tomography corresponding to Fisher group 3. All patients underwent surgery within 96 hours following SAH and received the thromboxane A2 synthetase inhibitor, OKY-046, as part of standard care. FUT-175 (40-160 mg/day) was administered during the initial 4 days following surgery. 455 patients treated without FUT-175 in the Nagasaki SAH Data Bank (non-FUT group) formed the control group. FUT-175 significantly decreased the incidence of symptomatic vasospasm in patients with severe neurological grade (Hunt and Hess grade 3, p < 0.02; Hunt and Hess grade 4, p < 0.02). The incidence of favorable outcome was 76.5% in the FUT group and 60.4% in the non-FUT group, but not statistically different. However, when patients of Hunt and Hess grade 5 were excluded, the FUT group had a significantly improved outcome (p < 0.05). This study suggests that FUT-175 has an additive effect to OKY-046 in preventing vasospasm in high risk patients with severe SAH.

Aged↗
PubMed1996

Acid lipase inhibitor in chicken plasma identified as apolipoprotein A-I.

We have reported a inhibitor of acid lipases in liver lysosomes and erythrocytes from chickens [M. Fujii et al., Int. J. Biochem., 22, 895-898 (1990)]. In this paper, the properties of the inhibitor were described in comparison with those of apo A-I of chicken. The purified inhibitor migrated with the same mobility on SDS-PAGE as apo A-I, and had a molecular weight of 27,000. The peptide map from the lipase inhibitor was similar to that of apo A-I. Antibodies to the acid lipase inhibitor also reacted with apo A-I. Apo A-I inhibited the acid lipase activities of liver lysosomes and erythrocytes from chickens as strongly as the lipase inhibitor. The N-terminal amino acid sequence of lipase inhibitor was identical to that of apo A-I as far as residue 20. The amino acid sequence of peptides obtained from the inhibitor by cleavage with CNBr corresponded to internal sequence of apo A-I, and so the CNBr-peptides were derived by cleavage after the methionine residues in apo A-I. The findings showed that the inhibitor of the acid lipases in liver lysosomes and erythrocytes from chickens was identical to apo A-I.

Amino Acid Sequence↗
PubMed1996

N-linked sugar chain of 55-kDa royal jelly glycoprotein.

An N-linked sugar chain from 55-kDa royal jelly glycoprotein (RJGP), which maintains the high viability of rat liver primary cultured cell and is a different molecular species from 350-kDa RJGP [Kimura et al., Biosci. Biotech. Biochem., 59, 507-509 (1995)], has been identified. The sugar chains were released by hydrazinolysis followed by N-acetylation and pyridylamination. The structural analysis of the pyridylaminated sugar chain was done by a combination of sequential exo-mannosidase digestions, MALDI-TOF MS, and 500 MHz 1H-NMR. For the carbohydrate moiety of 55-kDa RJGP, only one N-linked sugar chain has been detected. The structure has been found to be Man alpha 1-->2Man alpha 1-->6(Man alpha 1--> 2Man alpha 1-->3)Man alpha 1-->6(Man alpha 1-->2Man alpha 1-->2Man alpha 1-->3)Man beta 1-->4GlcNAc beta 1-->4GlcNAc, which is a non-processed high mannose type structure.

Animals↗