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M Soejima

Publications and source records attributed to M Soejima.

60 records · Page 4Linked to original sources
PubMed1983

Single channel analysis of the inward rectifier K current in the rabbit ventricular cells.

The inward rectifier K channel in rabbit ventricular cells was studied by the patch-clamp method. Single channel currents were recorded in giga-sealed cell-attached patches with 150 mM K+ in the pipette. The slope conductance in the membrane potential range from -140 to -40 mV was 46.6 +/- 6.7 pS (mean +/- S.D., n = 16), and was reduced by decreasing [K+] in the pipette (20 or 50 mM). The channel was blocked by an application of Cs+ or Ba2+ (0.04-1 mM) in the pipette. Outwardly directed current, recorded with 50 mM K+ in the pipette, revealed the inward rectification of the single channel current. The probability of the channel being open was 0.33 +/- 0.05 (n = 10) at the resting potential (RP=-81.7 +/- 1.7 mV, n = 16) with 150 mM K+ in the pipette, and it decreased with hyperpolarization. The mean open time of the channel was 178 +/- 25 msec (n = 6) at RP. The closed time of the channel seemed to have two exponential components, with time constants of 11.0 +/- 2.0 msec and 1.92 +/- 0.52 sec (n = 6) at RP. The slower time constant was increased with hyperpolarization. The averaged patch current recorded upon hyperpolarizing pulses demonstrated a time-dependent current decay as expected from the single channel kinetics. The results indicated that the inward rectifier K+ current has time- and voltage-dependent kinetics.

Animals↗
PubMed1981

Studies on a new proteolytic enzyme from A chromobacter lyticus M497-1. I. Purification and some enzymatic properties.

Achromobacter lyticus M497-1 produces three kinds of alkaline proteases (protease I, II and III) in culture medium along with the bacteriolytic enzyme (Masaki, T., Nakamura, K., Isono, M. and Soejima, M. (1978) Agric. Biol. Chem. 42, 1443--1445). Among these three proteases, Achromobacter protease I (EC 3.4.21.-) shows strict splitting for lysine residues at the carboxyl side of the splitting point. This enzyme was purified through a sequence of benzalkonium chloride treatment, acetone fractionation, CM-cellulose and DEAE-cellulose treatment chromatography on AH-Sepharose 4B and isoelectric focusing method. This form was shown to be homogeneous by polyacrylamide gel electrophoresis and ultracentrifugation analysis. The physicochemical properties of the enzyme were: Mr 30 500; partial specific volume (v), 0.717 ml/g; intrinsic viscosity (nu), 0.0385) dl/g; isoelectric point (pI) 6.9; and E1%1cm at 280 nm, 18.77. The enzyme was composed of 294 residues of amino acid per molecule, with glycine as NH2-terminal and lysine as COOH-terminal amino acids. The optimum pH values with casein, Bz-lys-pNA and Tos-Lys-OMe were 8.5--10.7, 9.0--9.5 and 7.8--8.2, respectively. The enzyme was inhibited by iPr2P-F, PhCH2SO2F and Tos-LysCH2Cl but not by Tos-ArgCH2Cl, EDTA, o-phenanthroline and PCMB.

Amino Acids↗
PubMed1981

Studies on a new proteolytic enzyme from Achromobacter lyticus M497-1. II. specificity and inhibition studies of Achromobacter protease I.

The unique specificity of Achromobacter protease I for lysine residue was investigated using synthetic and natural substrates, i.e., lysine derivatives, arginine derivatives, lysine vasopressin, substance P, ACTH and insulin. The enzyme cleaved only the -Lys-X- bonds in the above substrates. The binding affinity of alkylamines as determined by Ki was much stronger than that of the corresponding alkylguanidines.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Systemic necrotizing vasculitis with renal involvement accompanied by remarkable eosinophilia: a case with overlapping features of polyarteritis nodosa and allergic granulomatous angiitis.

A 71-year-old woman was clinically suspected of allergic granulomatous angiitis (AGA) because of preceding allergic diseases including bronchial asthma, remarkable eosinophilia (14,300/mm3), mononeuritis multiplex, positive rheumatoid factor, elevated serum immunoglobulin E, and eosinophilic inflammation of the kidney. Autopsy findings, however, were characterized of polyarteritis nodosa (PAN). Necrotizing angiitis was present in several organs except for the lung; focal and segmental glomerular lesions with crescent formation were observed in the kidney, and granuloma formation was not found. This case may be an intermediate type between PAN and AGA (an overlap syndrome) and provide useful information on the clinical entities of systemic necrotizing vasculitis.

Aged↗
PubMedDate not supplied

Rapid decline of residual renal function in patients on automated peritoneal dialysis.

OBJECTIVE: To determine the effect of peritoneal dialysis modalities such as nightly intermittent peritoneal dialysis (NIPD), continuous cyclic peritoneal dialysis (CCPD), and continuous ambulatory peritoneal dialysis (CAPD) on residual renal function. DESIGN: A six-month prospective, nonrandomized comparison study. SETTING: Outpatient CAPD unit of a university hospital. PARTICIPANTS: Eighteen end-stage renal disease patients treated by peritoneal dialysis (8 by NIPD, 5 by CCPD, and 5 by CAPD). INTERVENTIONS: Samples from the total dialysate, blood, and 24-hour urine collection were obtained monthly. MEASUREMENTS: Urea, creatinine, and beta2-microglobulin concentrations were measured. Renal and peritoneal clearances of each substance and KT/V urea were calculated. Residual renal function (RRF) was estimated by renal creatinine clearance (RCcr). RESULTS: No significant differences in age, sex, and primary renal disease among the three groups were noted. In all groups, anemic and hypertensive states were controlled identically, and mean weekly total (renal + peritoneal) KT/V urea (over 2.1/wk) and total creatinine clearance (over 60 L/wk/1.73 m2) were maintained during the whole experimental period. Starting mean RCcr was near 4.0 mL/min/1.73 m2 in all groups. Thereafter, a rapid and significant decline in RRF was demonstrated on NIPD and CCPD. The declining rates of RCcr values at 6 months after starting NIPD and CCPD were -0.29 and -0.34 mL/min/month, respectively, which were much greater than those of CAPD (+0.01 mL/min/month). CONCLUSION: Because of a possibly characteristic progressive loss of RRF in automated peritoneal dialysis (APD), strict regular assessment of RRF should be performed from the start of APD.

Adult↗