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Biomedical subjects

M Usui

Publications and source records attributed to M Usui.

At least 181 records · Page 10Linked to original sources
PubMed1996

[Systemic vascular change associated with moyamoya-like cerebrovascular disease and microvascular coronary artery disease].

A 34-year-old man with hypertension and diabetes mellitus developed dizziness and visited our institute. He had history of headache with numbness of the right hand since age 15 years and left occipital lobe infarction at age 28 years. The cerebral angiogram showed several changes peculiar to advanced stage of moyamoya disease (spontaneous occlusion of the circle of Willis), i.e. segmental stenoses or occlusions of bilateral internal carotid arteries, left vertebral artery and left posterior cerebral artery with abnormal vascular networks at the bilateral basal ganglia. He was also diagnosed to have asymptomatic ischemic heart disease. The coronary angiogram showed diffuse sclerotic lesions of left anterior descending and right coronary arteries without significant stenosis, which suggested the presence of microvascular lesion as a cause of myocardial ischemia. Coronary disease has been rarely reported as a complication of moyamoya disease, and microvascular coronary artery disease has never been described. Moyamoya disease should be regarded as a part of systemic vascular disorders, and the evaluation of extracerebral cardiovascular system is necessary to clarify pathophysiology of this disease.

Adult↗
PubMed1996

[A case report of concomitant carotid and coronary artery reconstruction].

We reported a case of a 70-year-old female who underwent simultaneous carotid endarterectomy and coronary artery bypass surgery. Preoperatively, cardiac catheterization demonstrated three vessel coronary artery disease. Her carotid angiogram revealed a 90% stenosis in the left common carotid artery. The cerebral blood flow scintigram on acetazolamide stress detected severely reduced cerebral blood flow on her left anterior and temporal lobe. Her postoperative course was uneventful. Postoperatively, no reduced cerebral blood flow was detected on the acetazolamide stress image. In patients with significant carotid artery stenosis, the cerearal blood flow scintigraphy on acetazolamide stress was a useful method for the simultaneous carotid endarterectomy and coronary artery bypass surgery.

Acetazolamide↗
PubMed1995

Avian neurosteroids. II. Localization of a cytochrome P450scc-like substance in the quail brain.

We have recently demonstrated that the avian brain as well as the peripheral steroidogenic glands produces pregnenolone, the main precursor of steroid hormones, on the basis of biochemical studies. Therefore, the immunohistochemical and Western immunoblotting analyses with a polyclonal antibody directed against the purified bovine adrenal cytochrome P450scc, which is involved in pregnenolone formation, was undertaken to investigate the localization of a cytochrome P450scc-like substance in the brain of adult male Japanese quails. P450scc-like immunoreactive cells were distributed in several telencephalic, diencephalic and mesencephalic regions. An intense immunoreaction was observed in somata of Purkinje cells and in the dendrites extending through the cerebellar molecular layer. Clusters of immunoreactive cell bodies were also detected in the hyperstriatum accessorium (HA), the ventral portions of both the archistriatum and the corticoid area, the preoptic area (POA), the anterior hypothalamus (AHy) and the dorsolateral thalamus (DL). Preadsorbing the antibody with cytochrome P450scc resulted in a complete absence of P450scc-like immunoreactivity in all of positively stained cells. On Western immunoblotting with the P450scc antibody, a P450scc-like substance was present in homogenates of the several brain regions that contain immunohistochemically stained cells. Immunohistochemical experiments using both antibodies against P450scc and the glial fibrillary acidic protein (GFA), a specific marker of glial cells, indicated that many HA cells contained both P450scc-like and GFA-like immunoreactivities. However, no immunoreactivity for GFA was observed in Purkinje cells and the cells localized in the ventral portion of the corticoid area, despite the presence of P450scc-like immunoreactivity. These results confirm our previous findings of pregnenolone biosynthesis and suggest the presence of a P450scc-like substance in both neuronal and glial cells of the quail brain.

Animals↗
PubMed1995

A 17-year follow-up of replantation of a completely amputated leg in a child: case report.

With special reference to skeletal growth, a 17-year follow-up study of a lower-leg replantation in a four-year-old boy is reported. The patient maintained good cosmesis and function; however, foot size on the affected side was 1.5 cm smaller than the contralateral side, and leg length was 1.2 cm shorter than on the normal side. A Cybex II study disclosed that the patient had almost half-standard strength of the evertors at 30 deg/sec and of the plantar flexors at 20 and 120 deg/sec on the involved side. According to these findings on late follow-up of a replanted foot in a child, replantation in a growing child apparently has adverse influences on skeletal growth and muscle strength around the ankle joint, even when the original procedure has been carried out under almost ideal conditions.

Adult↗
PubMed1995

Carbohydrate structures of the glycoprotein allergen Cry j I from Japanese cedar (Cryptomeria japonica) pollen.

The glycoprotein allergen Cry j I from Japanese cedar (Cryptomeria japonica) pollen was treated with pepsin and glycopeptidase A to release asparagine-linked oligosaccharides. The reducing ends of the oligosaccharides were aminated with the fluorescent reagent 2-aminopyridine. The oligosaccharide derivatives were purified by gel permeation chromatography and reversed-phase HPLC. Their structures were determined by sequential exoglycosidase digestion and 500 MHz 1H-NMR spectroscopy. Four oligosaccharide structures, A, B, C, and D, were identified as the xylose-containing complex-type. They were present at a molar ratio of 8:1:6:1. By amino acid sequence analyses of the tryptic peptides, Asn-170 and Asn-333 of Cry j I were found to carry asparagine-linked oligosaccharides. [formula: see text]

Allergens↗
PubMed1995

Prolongation of intraventricular conduction time associated with fatal [correction of fetal] impairment of defibrillation efficiency during treatment with class I antiarrhythmic agents.

To test whether fatal deterioration of defibrillation efficiency during antiarrhythmic therapy can be prevented by avoiding extreme decrease in ventricular prevented by avoiding extreme decrease in ventricular conduction or toxic plasma drug levels, we determined the defibrillation threshold (DFT) before and during infusion of incremental doses of disopyramide (n = 8), mexiletine (n = 9), or flecainide (n = 9) in anesthetized dogs. Disopyramide did not alter DFT [from 4.4 +/- 1.5 to 4.4 +/- 1.6 J (3.1 +/- 1.2 micrograms/ml)]. Mexiletine tended to increase DFT [from 4.6 +/- 1.2 to 6.1 +/- 2.0 J (1.8 +/- 0.6 micrograms/ml); p < 0.05], and defibrillation eventually was unsuccessful in 3 of the 9 dogs. Although the plasma mexiletine level before refractory fibrillation was far beyond the human therapeutic range, prolongation of intraventricular conduction time (CT) was moderate (16 +/- 3%). Flecainide increased DFT from 4.2 +/- 1.3 to 6.1 +/- 1.5 J at a plasma level of 1.04 +/- 0.37 micrograms/ml (p < 0.0005). In 3 of 5 dogs that developed refractory fibrillation, plasma flecainide level before terminal ventricular fibrillation (VF) was not toxic, but prolongation of CT in the 5 dogs was remarkable (30 +/- 9%). Thus, VF resistant to defibrillation is not necessarily associated with both toxic plasma drug level and remarkably decreased conduction. Reliability of these valuables as indicators of fatally deteriorated defibrillation efficiency may vary among antiarrhythmic agents.

Analysis of Variance↗
PubMed1995

Effect of isoproterenol on facilitation of electrical defibrillation by E-4031.

To determine whether isoproterenol could reverse enhancement of electrical defibrillation effectiveness by class III antiarrhythmic agents, we measured the internal defibrillation threshold (DFT) in 12 anesthetized dogs during infusion of (a) saline (baseline), (b) isoproterenol, (c) isoproterenol + E4031 (a new class III antiarrhythmic agent), and (d) E4031 alone. The isoproterenol infusion was adjusted so that heart rate (HR) was at least 30 beats/min greater than baseline. E4031 was given as a 40-micrograms/kg bolus at the beginning of the third stage of the study, followed by constant infusion at 2 micrograms/kg/min. Eight dogs completed the study. Although the energy-based DFT was not affected by isoproterenol (from 6.1 +/- 1.5 to 6.0 +/- 1.7 J), it was decreased to 3.7 +/- 1.6 J in the third stage by infusion of E4031 and isoproterenol (p < 0.01 vs. baseline and vs. isoproterenol). After the discontinuation of isoproterenol in the fourth stage, i.e., during infusion of E4031 alone, DFT was 3.4 +/- 1.6 J (p < 0.01 vs. baseline and vs. isoproterenol). Therefore, isoproterenol did not antagonize the effect of E4031 on the DFT, suggesting the possible clinical usefulness of class III agents for facilitating defibrillation even in the presence of augmented sympathetic activity.

Animals↗
PubMed1995

Cry j 2, a major allergen of Japanese cedar pollen, shows polymethylgalacturonase activity.

We examined Cry j 2, a major allergen of Japanese cedar (Cryptomeria japonica) pollen, for polygalacturonase enzyme activity, since a nucleotide sequence of cDNA of Cry j 2 showed a significant homology with that of tomato polygalacturonase. Polygalacturonase is well known to depolymerize preferentially polygalacturonic acid (PGA) by hydrolysis. However, Cry j 2 did not act on PGA, but was found to depolymerize pectin and methylesterified PGA in a dose-dependent manner. The substrate specificity of Cry j 2 was different from that of polygalacturonase derived from Aspergillus niger. The depolymerizing activity of Cry j 2 reached a maximum at 50%-60% of methylesterification of PGA. In contrast, polygalacturonase showed its maximum activity of PGA, and the activity decreased as the degree of methylesterification increased. Interestingly, the pectin-depolymerizing activity of Cry j 2 was due to a hydrolysis, but not a lyase, activity which splits the glycosidic bonds by beta-elimination, since no unsaturated uronides were found by measurement of absorbance at 235 nm in the reaction mixture. The enzyme activity was markedly inhibited by anti-Cry j 2 antibodies. These results indicate that Cry j 2 probably has polymethylgalacturonase enzyme activity, as postulated by von Neukom in 1963, although existence of this activity has not yet been proven.

Allergens↗
PubMed1995

Cry j I, a major allergen of Japanese cedar pollen, has pectate lyase enzyme activity.

In the course of analyzing the partial amino acid sequences of Cry j I, a major allergen of Japanese cedar (Cryptomeria japonica) pollen, we found a peptide fragment which has a significant homology to some pectate lyase isozymes secreted by plant pathogenic bacteria. Therefore, we investigated whether Cry j I has pectate lyase activity. Cry j I reacted with polygalacturonic acid, resulting in the release of unsaturated uronide products. The optimum temperature and pH for the reaction were 60-70 degrees C and pH 10. The enzymatic reaction had an absolute Ca2+ ion requirement. These characteristics were very compatible with the character of the pectate lyase isozymes reported previously. These results clearly show that Cry j I has pectate lyase activity.

Allergens↗
PubMed1995

Detection and identification of amines in bacterial vaginosis.

For the purpose of determining an objective indicator of bacterial vaginosis (BV), we tried to detect and to identify amines in the vaginal fluid of patients by using the dansyl method (to detect amine in a solution of water). Bacteria isolated from these patients were also analyzed. 1) In BV (n: 32) 7 kinds of amines were detected; and the positive rate of detection of the dansyl method was 90.6%. No specific bacteria was found in BV. 2) The positive rate was 80.0% for the patients with trichomonas vaginitis (n: 5). 3) The positive rate of detection was 20.0% in the candida group (n: 5), and 28.6% in the control group (n: 14). Those amines detected in other than BV-related vaginitis are presumed not to vaporize. For purposes of diagnosis, it would be better to detect vaporized amines instead of detecting amines dissolved in vaginal fluid.

Amines↗
PubMed1995

Influence of malpositioned transvenous leads on defibrillation efficacy with and without a subcutaneous array electrode.

Some patients cannot receive a transvenous lead system because of high defibrillation thresholds (DFTs). We hypothesized that a right ventricular (RV) catheter electrode not extending as far as possible into the RV apex could cause high DFTs. Recently, a subcutaneous array (SQA) electrode has been shown to lower DFTs substantially. We compared the influence of a malpositioned RV catheter electrode on defibrillation efficacy for endocardial lead systems with and without a SQA. In eight anesthetized pigs, defibrillation catheters were placed in the RV apex and near the junction of the superior vena cava (SVC) and right atrium. SQA, formed by three elements, each 20 cm in length, was placed in the left thorax. DFTs were determined for a biphasic waveform using an up/down protocol with the RV catheter at the apex and with it repositioned 1-cm and 2-cm proximal to the apex. The mean DFT energies for the configurations with a SQA were less than those without a SQA for every catheter position. The placement of the RV catheter away from the apex caused an increase in defibrillation energy for the configurations without a SQA (apex: 17.1 +/- 3.8 J [mean +/- SD]; 1 cm: 20.1 +/- 4.6 J; 2 cm: 27.6 +/- 9.5 J; P < 0.05), but not for the configurations with a SQA (apex: 12.2 +/- 2.2 J; 1 cm: 12.3 +/- 2.9 J; 2 cm: 12.1 +/- 0.9 J: P = NS). These results suggest that a malpositioned RV catheter electrode, at the time of implantation or by late dislodgment, significantly elevates DFTs for a total endocardial system but not for a system that includes a SQA.

Animals↗
PubMed1995

[Incidence of uveitis at Tokyo Medical College Hospital].

We reviewed the records of 980 patients with endogenous uveitis who were followed in the uveitis clinic of the Tokyo Medical College Hospital, Department of Ophthalmology. A group of 693 patients examined within a 5-year period from January, 1989 through December, 1993 (Group A) were compared to an earlier group of 287 patients examined within a 3-year period from January, 1982 through December, 1984 (Group B). The incidence of Behçet's disease, intermediate uveitis, and toxoplasmosis showed an apparent decrease. In contrast, the incidence of sarcoidosis and acute anterior uveitis increased. In comparison to Group B, Group A showed an increased number of patients with virus-associated uveitis, toxocariasis, and uveitis caused by fungal infection. The changes observed in the prevalence of certain uveitic diseases in the patient population we followed may be related to changing environment and/or life style, in addition to various advances in diagnostic testing. In the future, the classification of uveitis will become more varied according to the establishment of new concepts.

Adolescent↗
PubMed1995

Inhibition of parathyroid hormone-related protein release by extracellular calcium in dispersed cells from human parathyroid hyperplasia secondary to chronic renal failure and adenoma.

The relationship between parathyroid hormone-related protein (PTHrP) release from parathyroid cells and extracellular calcium ion concentration was investigated in three cases of parathyroid hyperplasia secondary to chronic renal failure and in four cases of parathyroid adenoma. Amounts of PTHrP released from individual parathyroid cells dispersed from surgical specimens were estimated by cell immunoblot assay. Parathyroid cells from both hyperplasias and adenomas showed significant suppression in the release of PTHrP with increase in extracellular calcium ions, but the amounts of PTHrP released from adenoma cells were significantly larger than from hyperplasia cells. The maximal value for PTHrP released within 120 minutes from adenoma cells was 2.91 +/- 2.11 x 10(-2) fmol/cell ([Ca2+], 0.4 mmol/L), and the minimal value was 1.32 +/- 0.35 x 10(-2) fmol/cell ([Ca2+], 2.0 mmol/L). On the other hand, the maximal value for PTHrP released from hyperplasia cells was 1.79 +/- 1.56 x 10(-2) fmol/cell ([Ca2+], 0.4 mmol/L), and the minimal value was 0.32 +/- 0.19 x 10(-2) fmol/cell ([Ca2+], 2.0 mmol/L). These results demonstrate actual release of PTHrP from abnormal parathyroid tissues into the extracellular space with the response to extracellular calcium ions depending on the cell status. Given the lack of definite histological criteria to differentiate between hyperplasias and adenomas in the parathyroid gland, the presently demonstrated significant difference in the ability to release PTHrP is important in pointing to parathyroid hyperplasia secondary to chronic renal failure as a distinct pathological entity separate from parathyroid adenoma.

Adenoma↗
PubMed1995

[Clinical and histological effect of induction chemotherapy with peplomycin, vincristine, mitomycin C and cis-platinum on oral squamous cell carcinomas].

Twenty one patients with resectable oral cancer received two courses of induction chemotherapy with peplomycin (PEP), vincristine (VCR), mitomycin C (MMC) and cisplatin (CDDP). Five patients had a complete response to the therapy and 9 had a partial response. Histological evaluation by Ohboshi-Shimozato classification indicated that Grade IV was obtained in 7 cases, Grade III was in 4 cases. Moreover, the study suggested that this regimen was less effective for metastatic lymph lesions than that for the primary tumors.

Adult↗
PubMed1995

[Rapid diagnosis of adenoviral conjunctivitis by enzyme-linked immunosorbent assay (Adenoclone)].

We evaluated an enzyme-linked immunosorbent assay test (Adenoclone) for the rapid diagnosis of adenovirus infection in 589 cases of acute follicular conjunctivitis. Of 255 cases of adenoviral conjunctivitis proven by positive virus isolation. Adenoclone was positive in 51.0% by visual determination and 40.4% by spectrophotometry. Twenty-seven of 130 cases giving visually positive results were interpreted to be negative by spectrophotometry. In 334 adenovirus-negative cases, Adenoclone was negative in 99.1% and 99.4 by visual and spectrophotometric determination, respectively. Adenoclone was less sensitive in cases of adenovirus 3, 4 or 37, infections than in those of adenovirus 8, and also showed lower sensitivity in cases presenting mild conjunctivitis. Adenoclone is a rapid and easy test with high specificity but low sensitivity, and thus the test seems to be helpful in diagnosing adenoviral conjunctivitis.

Adenovirus Infections, Human↗
PubMed1994

Molecular cloning of the second major allergen, Cry j II, from Japanese cedar pollen.

Cloning of a cDNA from Cry j II, the second major allergen from Japanese cedar (Cryptomeria japonica) pollen, is described. An isolated Cry j II cDNA contained an open reading frame coding for 514 amino acid residues. The mature Cry j II protein consisted of 388 amino acid residues (R46-S433). According to a homology analysis, no amino acid sequence homology was observed between Cry j II and Cry j I, another major allergen. But Cry j II showed homology with polygalacturonase (PG) derived from tomato (40% identity) at the amino acid level. The sequence information can potentially be used to devise an effective course of immunotherapy for Japanese cedar pollinosis.

Allergens↗