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Biomedical subjects

Y Mino

Publications and source records attributed to Y Mino.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Complement-mediated solubilization of immune complexes in immune complex nephritis].

In order to examine the ability of complement to solubilize the immune complexes (IC) in vivo, we made acute or chronic serum sickness nephritis in 10 rabbits or 12 rats with injection of BSA as antigen (Ag). Animals were divided into two groups. The 500 mu or 50 mu/week of cobra venom factor (CVF) for rabbits or rats was administered intraperitoneally in one group of animals to reduce the serum complement levels and complement-mediated solubilization of immune complex. On the other hand, the 2 ml or 0.2 ml/week of turpentine oil (TO) was injected intramuscularly in another group of animals to elevate the serum complement levels. The renal biopsy was performed with weekly intervals in each animals, and the specimens were stained for antigen (BSA), antibody (IgG) and C3 by immunofluorescence techniques. The result in this experiments showed the significant difference between TO-, and CVF-treated animals in the degree of disappearance of IC in the kidney lesions. The undetectable amount of IC (especially BSA) was remained in the renal tissue of TO-treated animals. This fact indicated that complement might act to solubilize the IC deposited in the tissue in vivo also.

Animals↗
PubMed1988

Spectral characterization of manganese peroxidase, an extracellular heme enzyme from the lignin-degrading basidiomycete, Phanerochaete chrysosporium.

Manganese peroxidase (MnP) is a component of the lignin degradation system of the basidiomycetous fungus, Phanerochaete chrysosporium. This novel MnII-dependent extracellular enzyme (Mr = 46,000) contains a single protoporphyrin IX prosthetic group and oxidizes phenolic lignin model compounds as well as a variety of other substrates. To elucidate the heme environment of this enzyme, we have studied its electron paramagnetic resonance and resonance Raman spectroscopic properties. These studies indicate that the native enzyme is predominantly in the high-spin ferric form and has a histidine as fifth ligand. The reduced enzyme has a high-spin, pentacoordinate ferrous heme. Fluoride and cyanide readily bind to the sixth coordination position of the heme iron in the native form, thereby changing MnP into a typical high-spin, hexacoordinate fluoro adduct or a low-spin, hexacoordinate cyano adduct, respectively. EPR spectra of 14NO- and 15NO-adducts of ferrous MnP were compared with those of horseradish peroxidase (HRP); the presence of a proximal histidine ligand was confirmed from the pattern of superhyperfine splittings of the NO signals centered at g approximately equal to 2.005. The appearance of the FeII-His stretch at approximately 240 cm-1 and its apparent lack of deuterium sensitivity suggest that the N delta proton of the proximal histidine of the enzyme is more strongly hydrogen bonded than that of oxygen carrier globins and that this imidazole ligand may be described as having a comparatively strong anionic character. Although resonance Raman frequencies for the spin- and coordination-state marker bands of native MnP, nu 3 (1487), nu 19 (1565), and nu 10 (1622 cm-1), do not fall into frequency regions expected for typical penta- or hexacoordinate high-spin ferric heme complexes, ligation of fluoride produces frequency shifts of these bands very similar to those observed for cytochrome c peroxidase and HRP. Hence, these data strongly suggest that the iron in native MnP is predominantly high-spin pentacoordinate. Analysis of the Raman frequencies indicates that the dx2-y2 orbital of the native enzyme is at higher energy than that of metmyoglobin. These features of the heme in MnP must be favorable for the peroxidase catalytic mechanism involving oxidation of the heme iron to FeIV. Consequently, it is most likely that the heme environment of MnP resembles those of HRP, cytochrome c peroxidase, and lignin peroxidase.

Basidiomycota↗
PubMed1987

Hydrogen bonding of sulfur ligands in blue copper and iron-sulfur proteins: detection by resonance Raman spectroscopy.

The resonance Raman spectrum of the blue copper protein azurin from Alcaligenes denitrificans exhibits nine vibrational modes between 330 and 460 cm-1, seven of which shift 0.4-3.0 cm-1 to lower energy after incubation of the protein in D2O. These deuterium-dependent shifts have been previously ascribed to exchangeable protons on imidazole ligands [Nestor, L., Larrabee, J. A., Woolery, G., Reinhammar, B., & Spiro, T. G. (1984) Biochemistry 23, 1084] or to exchangeable protons on amide groups which are hydrogen bonded to the cysteine thiolate ligands (a feature common to all blue copper proteins of known structure). In order to distinguish between these two possibilities, a systematic investigation of Fe2S2(Cys)4-containing proteins was undertaken. Extensive hydrogen bonding between sulfur ligands and the polypeptide backbone had been observed in the crystal structure of ferredoxin from Spirulina platensis. The resonance Raman spectrum of this protein is typical of a chloroplast-type ferredoxin and exhibits deuterium-dependent shifts of -0.3 to -0.5 cm-1 in the Fe-S modes at 283, 367, and 394 cm-1 (assigned to the bridging sulfurs) and -0.6 to -0.8 cm-1 in the Fe-S modes at 328 and 341 cm-1 (assigned to the terminal cysteine thiolates). Considerably greater deuterium sensitivity is observed in the Raman spectra of spinach ferredoxin and bovine adrenodoxin, particularly for the symmetric stretching vibration of the Fe2S2 moiety at approximately 390 cm-1. This feature decreases by 0.8 and 1.1 cm-1, respectively, for the two oxidized proteins in D2O and by 1.8 cm-1 for reduced adrenodoxin in D2O.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1986

Studies on motion sickness caused by high curve speed railway vehicles. Evaluation of the swing and its effects on passengers and conductors.

The high curve speed railway vehicles (HCSRVs) of the Japanese National Railway have been operating since 1973 with the aim of increasing speed on ordinary routes with many curve track sections. Although the aim of increased speed has been attained, it has been pointed out that the swing of HCSRVs is stronger than that of ordinary-type trains and it may increase motion sickness among the passengers and conductors. In this study, the authors examined motion sickness symptoms among 119 passengers and 100 conductors of both trains with a self-administered questionnaire, and evaluated the vibration acceleration on the floor by using the 1/3 Octave Band Analyzer and the Fast Fourier Transform method (FFT). The results can be summarized as follows: There were more passengers and conductors suffering from motion sickness riding on HCSRVs than those on the control trains. HCSRVs had the peak values of vibration acceleration within the range of 0.5 Hz and 1 Hz at horizontal, although the control train showed them above 1.0 Hz. These results suggest that the high rates of subjective complaints of passengers and conductors riding on HCSRVs were affected by vibration acceleration of frequency lower than 1 Hz.

Acceleration↗
PubMed1985

Partial purification and properties of phleinase induced in stem base of orchardgrass after defoliation.

Phleinase induced in stem base of orchardgrass (Dactylis glomerata L.) after defoliation was partially purified with ammonium sulfate precipitation, DEAE-Sephadex chromatography, gel filtration, and preparative polyacrylamide gel electrophoresis. The molecular weight of phleinase was 57,000 as determined by gel chromatography. The enzyme showed normal Michaelis-Menten kinetics and its K(m) value was 91 millimolar for phlein of mean degree of polymerization 60 as substrate. Reaction velocity of the enzyme was proportional to molarity of phlein irrespective of its chain length (mean degree of polymerization, 30 to 314). Phleinase attacked terminal fructosyl linkage of phlein by multi-chain mechanism. Phleinase cleaved beta-2,6 linkage, beta-2,6 linkage branched with beta-2,1 linkage, and beta-2,1 linkage of fructan in order of affinity, but not sucrose. Phleinase exhibited an optimum activity at pH 5.5 at 40 degrees C. Its complete inactivation occurred at 60 and 70 degrees C without and with phlein, respectively. Heat inactivation of the enzyme was enhanced by p-chloromercuribenzoate and protected partially by l-cysteine. The enzyme was inhibited by sulfhydryl reagents such as p-chloromercuribenzoate and Hg(2+). The modes of action of phleinase were compared with those of the related enzymes.

Journal Article↗
PubMed1985

Comparative study of the work load between one-man buses and two-man buses.

The differences in physiological and safety conditions of one-man buses and two-man buses were examined from the view point of occupational fatigue. This survey consisted of a work load study which included a time study, study of subsidiary behavior, auditory task, memory test, Galvanic Skin Response (GSR) and physiological function tests and a self-administered questionnaire which involved items concerning safety and subjective fatigue complaints. The visual and postural restrictions in the one-man bus were greater than in the two-man bus. The mental capacity of the one-man bus drivers was found to be less. Greater mental fatigue and stress were observed in the one-man bus. More subjective fatigue complaints were observed in the one-man bus. More cases of near accidents were observed in the one-man bus. From these results it was concluded that the one-man bus caused bus drivers a greater mental and physical work load.

Accidents, Traffic↗
PubMed1984

X-ray diffraction studies of enkephalins. Crystal structure of [(4'-bromo) Phe4,Leu5]enkephalin.

In order to investigate the structure-activity relationship of [Leu5]- and [Met5]enkephalins, [(4'-bromo)Phe4, Leu5]-, [(4'-bromo)Phe4, Met5]- and [Met5] enkephalins were synthesized and crystallized. The crystal structure of [(4'-bromo) Phe4, Leu5]- enkephalin was determined by X-ray diffraction method using the heavy atom method and refined to R = 0.092 by the least-squares method. The molecule in this crystal took essentially the same type I' beta-turn conformation found in [Leu5]enkephalin [Smith & Griffin (1978) Science 199, 1214-1216). On the other hand, the preliminary three-dimensional Patterson analyses showed that the most probable conformations of [(4'-bromo)Phe4,Met5]- and [Met5]enkephalins are both the dimeric extended forms. Based on these insights, the biologically active conformation of enkephalin was discussed in relation to the mu- and delta-receptors.

Crystallization↗
PubMed1984

Effects of consecutive night-shift work on health conditions among car-cleaners of super-express trains.

The Shinkansen Super-Express trains of the Japanese National Railways, the so-called bullet trains, run from early morning until late at night. Accordingly the car-cleaners of the Shinkansen must do late night shift work. A self-administered questionnaire survey including items about health and work conditions was given to 246 workers at Osaka Station, who were then divided into 3 groups: Group A consisted of 102 night workers working 5 successive days with 2 days off, Group B consisted of 124 alternate-day 24-hour workers working 3 days a week, while Group C included 20 day-workers working 6 days a week. A subjective fatigue inventory was administered before and after work for a week to 20 workers selected from each of three groups, group A, B above group D whose shift was 2 times 2 successive night shifts with one day off, and one holiday a week. The results of the questionnaire survey revealed that the rates of complaints such as gastroenteric disorders and general fatigue were the highest in group A. The results of the subjective fatigue inventory show a tendency for the number of complaints in group A and B to increase significantly after the last work shift of the week, but not in the case of group D. The authors demonstrated that there was a close relationship between patterns of night-shift work and various kinds of health problems, and concluded that to insert a day off on the third day of the group D shift was effective in reducing the work load.

Dizziness↗
PubMed1984

Production of monoclonal antibodies to human glomerular basement membrane.

Using the technique of somatic cell fusion, we produced monoclonal antibodies to collagenase-digested human glomerular basement membrane (GBM). Fourteen monoclonal antibodies which reacted with normal human kidney in indirect immunofluorescence (IIF) studies were produced. An analysis of the binding patterns indicated that the antigens recognized could be divided into six broad groups. Monoclonal antibody B3-H10 (Group 1) reacted with only GBM in a fine granular pattern. A5-B12 and B5-C2 (Group 2) reacted with GBM and peritubular capillary in a linear pattern. B2-A12 (Group 3) reacted with only epithelial cells. Al-C9 and A4-E2 (Group 4) showed a mesangial pattern in glomerulus and a lineal pattern in tubular basement membrane (TBM), Bowman's capsule and peritubular capillary. A1-E1, A1-E11, A2-E6, A3-B6, A4-F8 and B5-H2 (Group 5) recognized determinants common to GBM, TBM, Bowman's capsule and/or peritubular capillary. A3-F1 and B5-E10 (Group 6) reacted with TBM and Bowman's capsule. The staining pattern of B3-H10 (Group 1) was characteristic because it was not linear, but finely granular along the GBM. The staining pattern of B2-A12 (Group 3) was also characteristic because only epithelial cells were stained, and processes of epithelial cells were observed as fine fibrils. To the best of our knowledge, these two types of monoclonal antibodies have not been reported previously.

Animals↗
PubMed1983

Molecular sieve in bovine descemets membrane as revealed by negative staining.

Descemet's membrane was isolated from the corneas of cows and observed by electron microscopy after negative staining with 1% phosphotungstic acid solution, pH 7.2. Ultrastructurally, bovine Descement's membrane had a very regular hexagonal pattern. Nodes were connected to the six others around each of them by thin filaments to form a hexagon. The distance between the nodes was approximately 120 nm, the diameter of the nodes approximately 30 nm, and the width of the connecting filaments approximately 10 nm. Bovine Descement's membrane was a molecular sieve composed of nodes and filaments substantiating our molecular sieve theory of basement membranes.

Animals↗