Search PubMed⌕ Search

Biomedical subjects

M Sumi

Publications and source records attributed to M Sumi.

At least 109 records · Page 6Linked to original sources

[A case of rheumatoid arthritis accompanied by repeated pleural effusion associated with rapid tapering of steroid].

A 65-year-old woman was referred to our department because of general fatigue and anorexia for one month. The patient has received anti-rheumatoid therapy with aurothiomalate and bucillamine for the last two years for rheumatoid arthritis diagnosed 11 years earlier. Based on her systemic arthralgia, positive RA factor, and characteristic pleural effusion, the diagnosis of rheumatoid pleural effusion was made and prednisolone was administered. Two weeks later, the pleural effusion had improved. Rapid tapering of the drug over one month resulted in reappearance of pleural effusion. Slow tapering of prednisolone resulted in disappearance of the pleural effusion. One year after discharge, the patient was again referred to our department because of increased arthralgia. Pleural effusion reappeared after similar rapid tapering of the drug. These results suggest that induction of pleural effusion may occur in rheumatoid arthritis patients as a result of rapid tapering of steroids. Tapering of steroids in rheumatoid patients should be performed with care.

Aged↗

A DNA fragment homologous to F1-ATPase beta subunit was amplified from genomic DNA of Methanosarcina barkeri. Indication of an archaebacterial F-type ATPase.

A 490 bp DNA fragment was amplified from Methanosarcina barkeri genomic DNA by the polymerase chain reaction (PCR) using oligonucleotide primers designed based on conserved amino acid sequences of the F1-ATPase beta subunits. The amino acid sequence deduced from the DNA sequence of this fragment was highly homologous to a portion of the F1-ATPase beta subunit. This indicates that this archaebacterium has a gene of F-type ATPase in addition to a gene of V-type ATPase.

Amino Acid Sequence↗

Structure of holo-chaperonin studied with electron microscopy. Oligomeric cpn10 on top of two layers of cpn60 rings with two stripes each.

A structural model of holo-chaperonin, known as a protein-folding control protein comprising 60 kDa (cpn60) and 10 kDa polypeptides (cpn10), is proposed based on the electron microscopic images of holo-chaperonin from Thermus thermophilus and cpn60 from Paracoccus denitrificans. Isolated Paracoccus cpn60 shows very similar images to those of Escherichia coli tetradecameric cpn60, a seven-membered ring in the top view and a rectangular shape with four stripes in the side view. However, a small number of half-thick rectangles with two stripes are also seen which indicates that a single cpn60-heptamer ring has two stripes parallel to the plane of the ring. Thermus holo-chaperonin shows a bullet-like shape in the side view, and antibody against cpn10 binds only to the round side of the bullet. We conclude that a single cpn60-heptamer ring with two stripes stacks into two layers, and a cpn10 oligomer binds to one side of the layers.

Amino Acid Sequence↗

[Studies on risk factors influencing delayed resolution of pneumonia].

Among 61 patients admitted to our hospital because of bacterial pneumonia during the last six years, we investigated several risk factors influencing delayed resolution of pneumonia shadows, such as age, extent of the lesion, period of fever and sputum production after antibiotic therapy, WBC, CRP and PaO2 values on admission, the period of increased values of WBC and CRP, the presence or absence of etiological pathogens, the period from the appearance of symptoms to admission, and the period of drug therapy. In our series, the period from appearance of symptoms to admission (r = 0.62) and that of increased WBC (r = 0.35) significantly correlated with the period of pneumonia shadows to the time of their resolution. Similar results were obtained from the multiple variate analysis of various factors. These results suggest that the duration period (nontherapy period) of inflammation closely associated with leukocytosis plays a crucial role in the delayed resolution of pneumonia shadows.

Adult↗

The newly synthesized selective Ca2+/calmodulin dependent protein kinase II inhibitor KN-93 reduces dopamine contents in PC12h cells.

We reported that one of the isoquinolinesulfonamide derivatives, KN-62, is a potent and specific inhibitor of Ca2+/calmodulin-dependent protein kinase II (CaMKII) (Tokumitsu, H., Chijiwa, T., Hagiwara, M., Mizutani, A., Terasawa, M. and Hidaka, H. (1990) J. Biol. Chem. 265, 4315-4320). We have now investigated the inhibitory property of a newly synthesized methoxybenzenesulfonamide, KN-93, on CaMKII activity in situ and in vitro. KN-93 elicited potent inhibitory effects on CaMKII phosphorylating activity with an inhibition constant of 0.37 microM but this compound had no significant effects on the catalytic activity of cAMP-dependent protein kinase, Ca2+/phospholipid dependent protein kinase, myosin light chain kinase and Ca(2+)-phosphodiesterase. KN-93 also inhibited the autophosphorylation of both the alpha- and beta-subunits of CaMKII. Kinetic analysis indicated that KN-93 inhibits CaMKII, in a competitive fashion against calmodulin. To evaluate the regulatory role of CaMKII on catecholamine metabolism, we examined the effect of KN-93 on dopamine (DA) levels in PC12h cells. The DA levels decreased in the presence of KN-93. Further, the tyrosine hydroxylase (TH) phosphorylation induced by KCl or acetylcholine was significantly suppressed by KN-93 in PC12h cells while events induced by forskolin or 8-Br-cAMP were not affected. These results suggest that KN-93 inhibits DA formation by modulating the reaction rate of TH to reduce the Ca(2+)-mediated phosphorylation levels of the TH molecule.

Animals↗

[Clinical evaluation of per-rectal scintigraphy using I-123 IMP--evaluation of the portal hemodynamic changes after TAE].

Per-rectal portal scintigraphy using I-123 IMP was performed before and after TAE in 29 patients with hepatoma. Index of porto-systemic shunt (PSS index) was obtained by lung/(lung + liver) uptake ratio at 30 min after administration of IMP. The influence of TAE on portal circulation was evaluated by using this PSS index. PSS index increased 16 of 29 patients (55.2%) after TAE. PSS index increased after TAE especially in cases of severe liver dysfunction before TAE, marked portal involvement, and embolization of a larger liver volume. PSS index also increased when there was deterioration of esophageal varices, ascites, and hepatic coma after TAE. PSS index is useful for evaluation of portal circulation after TAE.

Amphetamines↗

A selective Ca2+/calmodulin-dependent protein kinase II inhibitor, KN-62, inhibits the enhanced phosphorylation and the activation of tyrosine hydroxylase by 56 mM K+ in rat pheochromocytoma PC12h cells.

Involvement of Ca2+/calmodulin-dependent protein kinase II (Ca2+/CaM-kinase II) on the phosphorylation of tyrosine hydroxylase (TH, EC.1.14.16.2) in rat pheochromocytoma, PC12h cells was examined using KN-62, 1-[N,O-Bis(5-isoquinolinsulfonyl)-N-methyl-L-tyrosyl]-4-phenylpipe razine, a selective inhibitor of Ca2+/CaM-kinase II. Both the enhanced phosphorylation of TH and the activated L-3,4-dihydroxyphenylalanine (DOPA) formation in the high K+ depolarization were inhibited by 10 microM KN-62. After incubation of PC12h cells with 10 microM KN-62 for 1 hr, the activation of TH with 3 min incubation of 56 mM K+ was reduced to the basal activity. However, KN-62 did not directly affect the activity of purified rat TH at pH 6.0 or 7.0. These results indicate that Ca2+/CaM-kinase II phosphorylates and activates TH of PC12h cells in the high K+ depolarization.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

[A comparative study between cefpirome (CPR) and ceftazidime (CAZ) in respiratory tract infections].

Efficacy and safety of a new injectable cephem antibiotic, cefpirome sulfate (hereafter, CPR), against respiratory tract infections were examined and compared with those of a control drug, ceftazidime (hereafter, CAZ). As a rule, CPR 0.5 g twice a day, 1.0 g twice a day, or CAZ 1.0 g twice a day (hereafter CPR 0.5 g group, CPR 1.0 g group, and CAZ group) was administered for 14 days and the following results were obtained. 1. The total number of cases was 470 (155 cases in the CPR 0.5 g group, 160 cases in the CPR 1.0 g group, and 155 cases in the CAZ group). Among them 390 cases were subjected to analyses of clinical efficacy by the efficacy evaluation committee (131 cases in the CPR 0.5 g group, 131 cases in the CPR 1.0 g group and 128 cases in the CAZ group). 2. Efficacy rates determined by the efficacy evaluation committee were 82.4% (108/131) for the CPR 0.5 g group, 81.7% (107/131) for the CPR 1.0 g group, and 83.6% (107/128) for the CAZ group. Efficacy rates determined by the physician in charge were 82.0% (105/128) for the CPR 0.5 g group, 80.5% (99/123) for the CPR 1.0 g group, and 88.5% (108/122) for the CAZ group. No statistically significant difference was observed among the 3 groups. In evaluation of equivalency, clinical efficacy for the CPR 0.5 g group and the CPR 1.0 g group determined by the clinical efficacy evaluation committee was proved to be statistically equivalent to that for the CAZ group. 3. In patients with pneumonia, efficacy rates determined by the efficacy evaluation committee were 87.1% (61/70) for the CPR 0.5 g group, 80.7% (71/88) for the CPR 1.0 g group, and 78.9% (56/71) for the CAZ group. Efficacy rates determined by the physician in charge were 85.3% (58/68) for the CPR 0.5 g group, 80.7% (67/83) for the CPR 1.0 g group, and 86.2% (56/65) for the CAZ group and no statistically significant difference was observed among the 3 groups. In patients with chronic respiratory tract infection, efficacy rates determined by the efficacy evaluation committee were 77.0% (47/61) for the CPR 0.5 g group, 83.7% (36/43) for the CPR 1.0 g group, and 89.5% (51/57) for the CAZ group. Efficacy rates determined by the physician in charge were 78.3% (47/60) for the CPR 0.5 g group, 80.0% (32/40) for the CPR 1.0 g group, and 91.2% (52/57) for the CAZ group. No statistically significant difference was observed among the 3 groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗

[An optimum dose-finding study of HR810 (CPR) in chronic respiratory tract infections].

In order to determine the optimal dose of cefpirome sulfate (HR810, CPR) against respiratory tract infections (RTI), an optimal dose-finding study was conducted on cases of chronic RTI, and the clinical properties of the drug were compared with those of ceftazidime (CAZ). Inpatients with chronic RTI were randomly assigned to 3 groups: an HR 0.5 g group, receiving 0.5 g X 2/day of CPR an HR 1.0 g group, receiving 1.0 X 2/day of CPR and a CAZ group, receiving 1.0 g X 2/day of CAZ. As a rule, the drugs were administered by intravenous drip infusion for 14 days, after which period clinical efficacy, bacteriological response, safety, and utility were investigated. Of the total 121 cases, 106 were subject to analysis of clinical efficacy, including 38 cases in the HR 0.5 g group, 32 in the HR 1.0 g group, and 36 in the CAZ group. Efficacy rates in the assessment by the committee were 84.2% for the HR 0.5 g group, 75.0% for the HR 1.0 g group, and 86.1% for the CAZ group, without any significant difference between the 3 groups. The bacterial elimination rates were 73.9%, 75.0% m and 88.5%, respectively, without any significant difference between the 3 groups. Associated reactions were noted in 2 of 36 cases in the HR 1.0 g group (eruption and diarrhea), but not in the other 2 groups. The incidence of abnormal clinical laboratory findings was 23.1% in the HR 0.5 g group, 22.2% in the HR 1.0 g group, and 22.5% in the CAZ group, without any significant difference between the 3 groups. Utility rates were 84.2% for the HR 0.5 g group, 74.2% for the HR 1.0 g group, and 86.1% for the CAZ group, without any significant difference between the 3 groups. The HR 0.5 g and 1.0 groups showed no difference in clinical efficacy, bacteriological response, safety, and utility against RTI, and the results of both groups were about equal to those of the CAZ group.

Adolescent↗

Differential diagnosis of gastric adenoma and type IIa early gastric cancer.

The endoscopic and radiographic findings of 45 gastric adenomas in 39 patients were followed for 6 months to 13 years and compared with type IIa early gastric cancer observed in 9 patients. Difficulties in the differential diagnosis of these disorders were evaluated. The following features were suggestive of gastric adenomas: clustered lesion; protuberance with gentle slope; smooth surface; and relatively young patients. Discrimination of adenoma from type IIa early gastric cancer is often difficult by visual observation alone; biopsy was essential in most patients. A group III adenoma verified on biopsy should be followed closely because the lesion may harbor a cancer (so-called carcinoma-in-adenoma) or a cancer may later develop.

Adenoma↗

d-Indobufen inhibits collagen-induced intracellular calcium mobilization and inositol phosphates formation in human platelets.

We obtained evidence that the cyclooxygenase inhibitor d-indobufen, (+)2[p-(1-oxo-2-isoindolinyl)phenyl] buthylic acid has a potent and specific inhibitory effect on collagen-induced aggregation and 40K-protein phosphorylation (Mamiya, S., Hagiwara, M., Ishikawa, T., and Hidaka, H. Thromb. Res. 54, 447, 1989). In Fura-2 loaded platelets, d-indobufen inhibited collagen-induced intracellular calcium mobilization in a dose dependent manner and this inhibitory effect on calcium mobilization paralleled that on aggregation, either in the presence or absence of extracellular free calcium ions. This compound inhibited inositol phosphates (IPs) formation in collagen-stimulated platelets. In arachidonic acid-stimulated platelets, d-indobufen caused a lag on calcium mobilization, as observed with arachidonic acid-induced aggregation. There was no significant effect on thrombin- or A23187-induced calcium mobilization or on aggregation. These observations suggest that the collagen receptor couples to a distinct intracellular calcium mobilization system possibly via inositol phospholipid metabolism and that d-indobufen blocks the collagen-induced aggregation by arresting mobilization of intracellular calcium.

Blood Platelets↗

Effect of aspartame on N-methyl-D-aspartate-sensitive L-[3H]glutamate binding sites in rat brain synaptic membranes.

Aspartame (L-aspartyl-L-phenylalanine methyl ester), an artificial low-calorie sweetener, was shown to dose-dependently inhibit L-[3H]glutamate binding to its N-methyl-D-aspartate-specific receptors. L-Aspartic acid, a major endogenous metabolite of aspartame, inhibited the binding more stronger than aspartame, while the other metabolites, L-phenylalanine and methanol, had no effect at the same concentration. Aspartame caused a significant change in the affinities of L-[3H]glutamate binding without altering the Vmax values of the binding, suggesting the inhibition is competitive. These in vitro findings suggested that aspartame may act directly on the N-methyl-D-aspartate-sensitive glutamate recognition sites in the brain synaptic membranes.

Animals↗

Continuous epidural infusion for postoperative mechanical ventilation.

We evaluated in analgesic and sedative effects of continuous epidural infusion of two analgesic regimens in ventilated patients following esophagectomy. Forty-six patients, divided into two treatment groups, received postoperative continuous epidural infusion of morphine, or that of a combination of bupivacaine and morphine. Assessments were made with the following indices: pain relief score, somnolence score, patient ventilator coordination score, and the number of supplemental administrations of analgesics and sedatives. No significant differences occurred in somnolence scores or patient ventilator coordination scores between the two groups, which revealed satisfactory sedation for mechanical ventilation. Patients receiving the combination of bupivacaine and morphine had significantly less pain postoperatively, requiring a smaller number of supplemental administrations of analgesics and sedatives ( P < 0.05). It is concluded that: 1) continuous epidural infusion of analgesics gives potent analgesia and sedation of ventilated patients following esophagectomy; 2) the combination of bupivacaine and morphine gives pain relief superior to morphine alone.

Journal Article↗

Discrepancy of protein kinase C translocation and platelet aggregation--immunocytobiochemical evidence.

We searched for possible relationships between platelet aggregation induced by 12-O-tetradecanoyl phorbol 13-acetate (TPA) or thrombin and the translocation of protein kinase C. Using monoclonal antibodies against subspecies of protein kinase C, we noted a predominant expression of the isozyme, type II, in human platelets (M. Watanabe, M. Hagiwara, K. Onoda, and H. Hidaka, 1988, Biochem. Biophys. Res. Commun. 152, 642). Analysis of the subcellular distribution of protein kinase C revealed that 65% of the kinase activity was present in the cytosolic fraction in unstimulated platelets, with the remaining activity in the membrane fraction. Treatment of platelets with 100 nM TPA resulted in a greater than 60% decrease in protein kinase C activity in the cytosolic fraction and a greater than 200% increase in the activity in the membrane fraction, within 10 min after treatment. Translocation of the enzyme was also found after treatment of platelets with thrombin, although the response was of lower magnitude than that induced by TPA. Similar results were obtained by immunoblotting using MC-2a, an anti-type II protein kinase C monoclonal antibody. We also examined localization of the enzyme, by electron microscopic immunocytochemistry. The presence of type II protein kinase C seemed to be localized mostly in hyaluromeres and not in granulomeres. When platelets were fixed just after the addition of TPA (within 1 min), protein kinase C was localized at the submembranal region with no remarkable change in shape but there was a decrease in the number of granules in the cytoplasma and the open canalicular system was dilated. We then investigated the effects of cytochalasin B, W-7, ML-9, and H-7 on TPA-induced platelet aggregation and the translocation of protein kinase C. W-7 and ML-9 potently inhibited platelet aggregation but none of these compounds hampered the translocation. Thus, activation of protein kinase C may not be a complete requirement for the initiation of platelet aggregation.

Antibodies, Monoclonal↗

Processing of an NH2-terminally extended thermostable alpha-amylase by Bacillus subtilis alkaline protease.

To analyze the processing of extracellular enzymes of Bacillus subtilis, an NH2-terminally extended hybrid alpha-amylase [pTUBE638-alpha-amylase (E24)] was purified from the periplasm of E. coli(pTUBE638) as the substrate for the in vitro processing reaction, in which a 21-amino-acid extra-peptide was added at the NH2-terminus of the mature thermostable alpha-amylase. The extended peptide in pTUBE638-alpha-amylase (E24) was completely processed by the extracellular alkaline protease of B. subtilis alone at pH 7.5 to 10.0. The processing was inhibited by 2 mM PMSF. In contrast, the neutral protease did not process the extended peptide. The processing activity of the purified alkaline protease was fully active in 100 mM phosphate and glycine-NaCl-NaOH buffer while it was partially active in 100 mM Tris-HCl or MOPS buffer. The optimum pH of the activity ranged from 8.0 to 9.0, although the optimum pH of the alkaline protease activity toward casein and Azocoll was 10.5. The NH2-terminal amino acid sequences of the enzymes processed in vitro coincided with those of the mature extracellular thermostable alpha-amylases in the culture medium of B. subtilis (pTUBE638). The appearance of the processing activity of alkaline protease was correlated with the changes of the pH in the culture medium.

Amino Acid Sequence↗

Pathomechanism, pathogenesis, and results of treatment in cervical spondylotic myelopathy caused by dynamic canal stenosis.

In this study, the pathomechanism and pathogenesis of dynamic canal stenosis caused by cervical instability in patients with cervical spondylotic myelopathy and the validity of the concept of instability are clarified by analyzing the results of treatment in 53 cases. In cases of cervical spondylotic myelopathy caused by dynamic canal stenosis, the authors found that the posterior slide of the vertebral body occurs as a result of degeneration in the cervical spine due to aging changes, and that the dynamic sagittal diameter of the spinal canal decreases with an increase of the degree of posterior slide. This is followed by gradual aggravation of the clinical symptoms. Continuous cervical traction was found to be the first choice of treatment. Surgical treatment is indicated in cases in which the traction was ineffective, or even when it was effective, in cases in which the Japanese Orthopaedic Association (JOA) score remained low or when there was a tendency toward rapid aggravation of symptoms. It was demonstrated that the shorter the duration of the myelopathy, the better the results of treatment obtained. A limit of the dynamic sagittal diameter of the spinal canal of 12 mm was considered as valid.

Cervical Vertebrae↗

Postoperative lumbar spinal instability occurring or progressing secondary to laminectomy.

The manifestations and pathomechanism of postoperative lumbar spinal instability, occurring or progressing secondary to laminectomy, was clarified by means of functional radiographic analysis in a series of 46 patients over 40 years of age. The relation between instability and the clinical symptoms also is discussed. In patients under 60 years of age, instability at the operated level tended to appear in cases of wide laminectomy more often than in cases of partial laminectomy. Occurrence or progress of instability seems to be promoted by resection of the posterior spinal elements rather than the disc. It is further considered that the postoperative aggravation of clinical symptoms may be influenced not only by instability, but also by the other factors.

Age Factors↗