Biomedical subjects
Publications and source records attributed to T Shimada.
In total, 131 strains of Plesiomonas shigelloides isolated from various sources were tested for peritrichous flagella by a flagella staining method. When incubated on a solid medium for 18 hr at 25 C, peritrichous flagella were demonstrated in 89 (68%) of them. With an electron microscope, the peritrichous flagella were clearly distinguished from the lophotrichous ones by their wavelength.
We studied the cardiovascular responses to laryngoscopy and intubation in 30 patients who received continuous infusion of either diltiazem 10 micrograms.kg-1.min-1, 40 micrograms.kg-1.min-1 or saline as control group during 20 min before induction. Heart rate, arterial pressure, rate pressure product (RPP), pressure rate quotient (PRQ) were measured starting 20 min before induction to 3 min after tracheal intubation. The increases in arterial pressure and RPP following tracheal intubation were reduced significantly in patients receiving diltiazem 40 micrograms.kg-1.min-1, but they were not reduced in patients receiving diltiazem 10 micrograms.kg-1.min-1 compared with control. We conclude that continuous infusion of diltiazem during 20 min before induction is effective for preventing the increases in arterial pressure and RPP following tracheal intubation, and the optimal infusion rate is from 10 to 40 micrograms.kg-1.min-1.
Although recently the occurrence of a malignant neoplasma as a complication of uremia is becoming more frequently, pharmacokinetics of antitumor agents are not precisely studied in patients with impaired renal function. In this report we investigated pharmacokinetics of enositabine (BHAC), arabinosylcytosine (Ara-C) and etoposide (VP-16) in a patient on maintenance hemodialysis who suffered from acute myelomonocytic leukemia and treated by BHAC-EV regimen. Pharmacokinetic parameters of BHAC in uremia were not different from that in patients with normal renal function, and hemodialysis did not affect on the plasma level of BHAC. No significant accumulation of Ara-C was seen in uremia, but there remained the possibility that Ara-C could be removed by hemodialysis. So BHAC was able to be used in uremic patients safely. Since VP-16 was proved to be not a hemodialyzable but an accumulative substance and prolongation of plasma half life was prompt in uremia, VP-16 should be administered to uremic patients very cautiously. From these results BHAC-EV regimen was presumed to be a safely, well tolerated and beneficial regimen in uremic patients.
Plasma concentration of fibrinogen (Fbg), plasminogen (PLG), antithrombin III (AT III), alpha 2-plasmin inhibitor (alpha 2-PI), thrombin antithrombin III complex (TAT) and plasmin alpha 2-plasmin inhibitor complex (PIC) were evaluated in 23 nephrotic patients with proteinuria more than 3.5 g/day, including 4 cases with clinical evidence of thromboembolism. Among patients without thromboembolism, concentration of PLG and AT III was in the normal range but that of Fbg and alpha 2-PI was significantly elevated (p less than 0.01 for Fbg and p less than 0.001 for alpha 2-PI respectively). Also there was a positive relationship between AT III and serum albumin (p less than 0.05). Two fifth of these patients had an had an increased level of TAT, and also had a higher level of PIC compared with normal control (p less than 0.01). There was a positive relationship between TAT and PIC, TAT and Fbg (p less than 0.05), PIC and Fbg (p less than 0.01). TAT and PIC levels were markedly elevated in the patients with thromboembolism. From aforementioned data, it was suggested that patients with nephrotic syndrome would be in the prethrombotic state and the increased level of Fbg is one of the major risk factors of thromboembolic complications in these patients. Furthermore measurement of TAT and PIC are the useful means for the diagnosis of these complications.
To assess the protective effects of L-carnitine (LC) infusion on ischemic heart disease, 30 patients who had angina and ischemic ECG changes during exercise were evaluated by bicycle ergometry. They were categorized in LC and non-treatment (NT) groups. There were no significant differences in age and sex between the 2 groups. Before exercise, 15 patients (9 males and 6 females) received 60 mg/kg LC and the results including hemodynamics, coronary circulation, and cardiac metabolism at rest and during exercise were compared with those of the NT group studied in the same protocol (50 watts x to cycle, 15 min). At the end of 30 min LC drip infusion, the arterial carnitine content (LC (a)) reached 1,980 +/- 257.3 microM and then was maintained at 1,212.7 +/- 136.2 microM during exercise. There was no correlation of LC (a) with the coronary arterio-venous difference nor with myocardial uptake of LC. Although there was no significant difference in coronary blood flow (CBF: mliters/100 g/min) between the LC and NT groups at rest (LC: 92.1 +/- 29.0 vs NT: 88.0 +/- 26.5), CBF during exercise increased significantly in the LC group compared with the NT group (LC: 230.4 +/- 113.8 vs NT: 139.1 +/- 52.7; p < 0.05). In the NT group, there was no significant change in coronary arterio-venous oxygen difference ((a-cs) O2: vol %) during exercise, but in the LC group (a-cs) O2 increased significantly from 10.2 +/- 1.3 to 11.5 +/- 1.9 (p < 0.01). Furthermore, although there was no significant difference in myocardial oxygen consumption (MVO2: mliters/100 g/min) at rest between the 2 groups (LC: 9.30 +/- 2.96 vs NT: 9.71 +/- 3.09), it increased significantly in the LC group compared with the NT group during exercise (LC: 25.11 +/- 9.98 vs NT: 15.55 +/- 6.09). MVO2/LVWI (LVWI = left ventricular work index) and MVO2MT (MT = myocardial tension) did not significantly differ at rest between the 2 groups. However, these 2 indices decreased significantly during exercise (p < 0.05) in the NT group, and remained unchanged in the LC group, showing a significant difference between the 2 groups (both p < 0.05). In myocardial energy substrates, the myocardial uptake ((a-cs) x CBF) of free fatty acid (FFA: muEq/100 g/min) increased significantly in the LC group compared with that of the NT group (LC: 10.16 +/- 13.26-->31.88 +/- 27.58* vs NT: 16.02 +/- 27.92-->18.11 +/- 31.00;* = p < 0.05, LC vs NT).
Characteristics of venous return and its determining factors were observed using pulsed Doppler echocardiography. Superior vena caval (SVC) flow was regarded as representing venous return. Ten healthy subjects and 23 patients with chronic pulmonary disease were studied. 1. In the healthy subjects, the forward flow was biphasic with dominant systolic (S) wave. Among 23 patients, 18 had normal SVC flow patterns (Group I), while in the remaining 5, SVC flow showed disappearance of the diastolic (D) wave, or both the D and S waves (Group II). 2. The healthy subjects and Group I patients had negative pleural pressures during inspiration and expiration. Consistent findings in Group II patients included positive pleural pressures during expiration and reduction in FEV1.0%. In the normal subjects and Group I patients, right atrial (RA) pressure was less than the pressure of the subclavian vein (ScV) during an entire respiratory phase. However, in Group II, RA pressure was equal to or greater than ScV pressure during expiration, resulting in disappearance or reversal of the S and D waves. 3. Respiratory variation in pleural pressure correlated significantly with that of the S wave (r = 0.77) (p < 0.005), D wave (r = 0.80) (p < 0.005), x descent of RA pressure (r = 0.77) (p < 0.005), and y descent of RA pressure (r = 0.82) (p < 0.005). The present study clearly confirmed that the superior vena caval flow patterns were closely correlated with right heart hemodynamics and truly reflected the effects of pleural pressure.
We developed a new body surface isopotential mapping system using a colored spatial mapping electrocardiographic technique based on Frank's vectorcardiography to be used with CERX CQ-3011 and NEC PC-100 computers. We assessed its usefulness in comparison with the conventional body surface mapping technique in 12 patients with old myocardial infarction (6 with anterior and 6 with inferior infarction), and in 10 healthy subjects. All distributions of positive and negative zones presented on body surface isopotential maps were obtained with this new technique, which corresponded well with the distribution of zones on conventional body surface isopotential maps. Although the maximum and minimum positions of the 2 maps did not coincide with one another, this new map aided in diagnosing anterior and inferior infarction from the minimum position determined 20 msec after the onset of QRS. This new mapping system allows a clear spatial representation of vectorcardiograms and requires less complicated procedure compared with the conventional body surface mapping technique. Thus, this body surface isopotential mapping system should be clinically useful.
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The serum levels of IgA class antibodies against autologous IgG Fc and Fab fragments were measured by ELISA in 62 patients with primary IgA nephropathy (IgAN) and 20 normal healthy volunteers. Both antibodies were significantly higher in the patients (P less than 0.01). The total IgA levels were correlated with those of IgA anti-IgG Fc antibodies (IgA anti-Fc) (rs = 0.57, P less than 0.001), but not with those of the IgA anti-IgG Fab antibodies (IgA anti-Fab). A histopathological comparison revealed that the sera of patients with severe glomerulonephritis had significantly higher levels of IgA anti-Fc than those with milder lesions (P less than 0.01). On the other hand, no correlation was observed between the serum levels of IgA anti-Fab and the histopathological severity. A comparison before and after treatment in 12 patients demonstrated a significant decrease of IgA anti-Fc (P less than 0.01) and an increase of IgA anti-Fab (P less than 0.05) after the treatment. Size analysis in serial sera from 3 patients was performed using HPLC under neutral (pH = 7.0) and under acid (pH = 3.5) buffer conditions. A markedly increased ratio of both antibodies with the polymeric form was observed in the active phase. In the remission phase, the amounts of acid-dissociable polymeric form IgA anti-Fc were decreased. In contrast, high levels of polymeric form IgA anti-Fab continued to be observed in 2 patients at this phase. These results suggest that abnormally stimulated production of IgA class autoantibodies especially with the polymeric form against both IgG Fc and Fab fragments, occurs in IgAN, involving separate regulation with differing reactions to treatment and a distinct relationship between IgA anti-Fc and active histopathological lesions.
Cytochrome P-450 (P-450) 2A6 was purified by chromatography of human liver microsomes. The final preparation was electrophoretically homogeneous and contained 16 nmol of P-450/mg of protein. The amino-terminal amino acid sequence of the protein (first 13 residues) matched that of the reported cDNA exactly. The UV-visible spectrum indicated that the isolated hemoprotein was in the low-spin form. The protein was recognized by rabbit antibodies raised against rat P-450 2A1, and a rabbit antiserum against the P-450 2A6 preparation was also prepared. With these antibodies, it was estimated that P-450 2A6 accounted for a maximum of 1% of the total P-450 present in the human liver microsomes; the level varied greater than 100-fold among the 20 samples examined. Purified P-450 2A6 catalyzed coumarin 7-hydroxylation and 7-ethoxycoumarin O-deethylation at rates similar to those measured in the human liver sample used to prepare P-450 2A6, and these two microsomal activities were strongly inhibited by the antibodies. The purified P-450 2A6 enzyme also catalyzed low levels of 4,4'-methylene-bis(2-chloroaniline) (MOCA) N-oxidation and activation of aflatoxin B1, 6-aminochrysene, 2-amino-3-methylimidazo[4,5-f]quinoline, and 2-amino-3,5-dimethylimidazo [4,5-f]quinoline to genotoxic products; the antibody inhibited the activity of purified P-450 2A6 towards aflatoxin B1 and 6-aminochrysene but did not inhibit these reactions in human liver microsomes (MOCA N-oxidation was inhibited approximately 20%). Human P-450 2A6 did not catalyze testosterone 7 alpha-hydroxylation, a characteristic activity of the related rat P-450 2A1 protein. These results emphasize the need to characterize individual P-450 enzymes in order to understand their functions in the context of more complex systems.
Molecular size and charge distribution of IgA of sera and glomerular eluates were investigated in ddY mice, spontaneously developing mesangial proliferative glomerulonephritis (GN) with IgA deposition after 40 weeks of age. Serum IgA levels were increased in aged ddY mice more than 40 weeks old with a significant increase (P less than 0.01) at the age of 60 weeks, comparing with those of BALB/c mice. The isoelectric focusing (IEF) spectrotype of pooled serum IgA in 60-week-old mice ranged from 4.2 to 5.5, being similar to those in younger ddY (16 weeks old) and control BALB/c mice (12 weeks old) without enhanced expression of specific IgA peaks. However, IgA in the glomerular eluate from the 60-week-old mice showed limited anionic spectrotypes from pH 4.2 to 4.8. HPLC of IgA in pooled sera and glomerular eluates of 16-, 40- and 60-week-old ddY mice, revealed markedly increased ratios of the dimeric IgA (dIgA) and polymeric IgA (pIgA) in the total IgA with age. In the contrast to serum profiles, monomeric IgA (mIgA) was always detected as the smallest peak of the IgA fractions in glomerular eluates. Furthermore, aged mice with severe GN showed a higher percentage of dIgA and pIgA in total IgA (80%) in the sera than that of the mice with mild GN (64%). HPLC analysis under acid condition of glomerular IgA from 40-week-old ddY mice showed a similar pattern of dIgA and pIgA peaks in neutral buffer without the appearance of mIgA. These findings suggest that there is a selective mechanism for glomerular accumulation of more acid IgA among the polyclonally expanded IgA in old ddY mice, and that the polymeric form of IgA plays a pathogenic role in the development of mesangial proliferative GN in these mice.
A 19-year-old female patient with renovascular hypertension accompanied by focal segmental glomerulosclerosis like lesion in the contralateral kidney is described. She was admitted to our hospital for uncontrollable hypertension which was first pointed out at check-up when she was 18 years old. On admission physical examination revealed remarkable hypertension and a bruit around the umbilical region. Laboratory findings disclosed renal dysfunction and slight proteinuria (0.8-1.1 g/day). Arteriography revealed severe narrowing of the right renal artery suggesting fibromuscular dysplasia. Taken together, renovascular hypertension was diagnosed. She underwent an operation to reconstruct the artery with autotransplantation of the ipsilateral kidney in the pelvic cavity, and sections were taken from both kidney for histological evaluation during the procedure. After the operation her blood pressure normalized and proteinuria decreased. And interestingly, the kidney specimens revealed that the left side consisted of focal segmental glomerulosclerosis like lesion whereas the right was only of ischemic change. Hyperfiltration theory has recently been highlighted experimentally. And the etiology of the renal findings in this case may be based on such hemodynamic alteration as has been described in animal models. We present the case so that it may be of some help to understand how focal segmental glomerulosclerosis is brought about in humans.
A human liver cytochrome P-450 (P-450) IIIA4 cDNA clone was inserted behind an alcohol dehydrogenase promoter in the plasmid vector pAAH5 and expressed in Saccharomyces cerevisiae (D12 and AH22 strains). A cytochrome P-450 with typical spectral properties was expressed at a level of approximately 8 x 10(5) molecules/cell in either strain of yeast. The expressed P-450 IIIA4 had the same apparent monomeric Mr as the corresponding protein in human liver microsomes (P-450NF) and could be isolated from yeast microsomes. Catalytic activity of the yeast microsomes toward putative P-450 IIIA4 substrates was seen in the reactions supported by cumene hydroperoxide but was often lower and variable when supported by the physiological donor NADPH. The catalytic activity of purified P-450 IIIA4 was also poor in some systems reconstituted with rabbit liver NADPH-P-450 reductase and best when both the detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate and a lipid extract (from liver or yeast microsomes) or L-alpha-1,2-dilauroyl-sn-glycero-3-phosphocholine were present. Under these conditions the expressed P-450 IIIA4 was an efficient catalyst for nifedipine oxidation, 6 beta-hydroxylation of testosterone and cortisol, 2-hydroxylation of 17 beta-estradiol and 17 alpha-ethynylestradiol, N-oxygenation and 3-hydroxylation of quinidine, 16 alpha-hydroxylation of dehydroepiandrosterone 3-sulfate, erythromycin N-demethylation, the 10-hydroxylation of (R)-warfarin, the formation of 9,10-dehydrowarfarin from (S)-warfarin, and the activation of aflatoxins B1 and G1, sterigmatocystin, 7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (both + and - diastereomers), 3,4-dihydroxy-3,4-dihydrobenz[a]anthracene, 3,4-dihydroxy-3,4-dihydro-7, 12-dimethylbenz[a]anthracene, 9,10-dihydroxy-9,10-dihydrobenzo[b]fluoranthene, 6-aminochrysene, and tris(2,3-dibromopropyl) phosphate to products genotoxic in a Salmonella typhimurium TA1535/pSK1002 system where a chimeric umuC' 'lacZ plasmid is responsive to DNA alkylation. Reaction rates were stimulated by 7,8-benzoflavone and inhibited by rabbit anti-P-450 IIIA (anti-P-450NF), troleandomycin, gestodene, and cimetidine. Evidence was obtained that rates of reduction of ferric P-450 IIIA4 in yeast microsomes and the reconstituted systems are slow and at least partially responsible for the lower rates of catalysis seen in these systems (relative to liver microsomes). The results of these studies with a defined protein clearly demonstrate the ability of P-450 IIIA4 to catalyze regio- and stereoselective oxidations with a diverse group of substrates, and this enzyme appears to be one of the most versatile catalysts in the P-450 family.
The mutagenicity of 1,2-dibromoethane is highly dependent upon its conjugation to glutathione by the enzyme glutathione S-transferase. The conjugates thus formed can react with DNA and yield almost exclusively N7-guanyl adducts. We have synthesized the S-haloethyl conjugates of cysteine and glutathione, as well as selected methyl ester and N-acetyl derivatives, and compared them for ability to produce N7-guanyl adducts with calf thymus DNA. The cysteine compounds were found to be more reactive toward calf thymus DNA and yielded higher adduct levels than did the glutathione compounds. Adduct levels tended to be suppressed when there was a net charge on the compound and were not affected by substitution of bromine for chlorine, as expected for a mechanism known to involve an intermediate episulfonium ion. Sequence-selective alkylation of fragments of pBR322 DNA was investigated. The compounds produced qualitatively similar patterns of alkylation, with higher levels of alkylation at runs of guanines. The compounds were also tested for their ability to act as direct mutagens in Salmonella typhimurium TA98 and TA100. None of the compounds caused mutations in the TA98 frameshift mutagenesis assay. In the strain TA100, where mutation of a specific guanine by base-pair substitution produces reversion, all compounds were found to produce mutations, but the levels of mutagenicity did not correlate at all with the levels of DNA alkylation. The ratio of mutations to adducts varied at least 14-fold among the various N7-guanyl adducts examined.(ABSTRACT TRUNCATED AT 250 WORDS)
The low-density lipoprotein (LDL) receptor of molecular mass 155 kDa was expressed on the cell surface of cultured mouse macrophage J774 cells. The conversion rate of precursor to mature form of LDL receptor in J774 cells was comparable to that in mouse fibroblast L cells. The half-life of the LDL receptor of J774 cells was about 2 h, that of L cells was about 11 h. The rapid degradation of LDL receptor was not significantly inhibited by the lysosomotropic agents, chloroquine and NH4Cl, nor by the thiol-protease inhibitors leupeptin and E-64. By contrast, incubation at 18 degrees C retarded the degradation of LDL receptor. Treatment of J774 cells with brefeldin A, an inhibitor of membrane transport between the endoplasmic reticulum and the Golgi apparatus, inhibited the rapid turnover of the LDL receptor. Even after a 9-h chase in the presence of brefeldin A, LDL receptor 5-10 kDa smaller than the normal mature form was found to be stable. Rapid turnover of the LDL receptor in the macrophages appeared to occur after exit from the Golgi apparatus, possibly during transport of the LDL receptor to the plasma membrane.
NADPH-fortified human liver microsomes were examined with regard to ability to detoxicate several chemicals that do not require enzymatic oxidation to elicit a genotoxic response in a Salmonella typhimurium TA1535/pSK1002 system where umu response is used as an indicator of DNA damage. Microsomes did not affect the response seen with daunomycin, mitomycin C, 2,4,7-trinitro-9-fluorene, 1-nitropyrene, doxorubicin, 1-methyl-3-nitro-1-nitrosoguanidine, 2-nitrofluorene, or 1-ethyl-3-nitro-1-nitrosoguanidine (cited in order of decreasing umu response per mol). Human and rat liver microsomes did inactivate 1,3-, 1,6-, and 1,8-dinitropyrene; with human liver microsomes the activity of 1,3-dinitropyrene was most strongly inhibited, while with rat liver microsomes the genotoxicities of all three dinitropyrenes were inhibited to a similar extent. NADPH-cytochrome P-450 reductase was demonstrated to inactivate 1,6- and 1,8-dinitropyrene but not 1,3-dinitropyrene. Both rat cytochrome P-450 beta NF-B (P-450 IA1) and P-450ISF-G (P-450 IA2) inactivated 1,3-dinitropyrene, with the former being more effective. Correlation studies done with liver microsomes prepared from variously treated rats and immunoinhibition studies suggest that cytochrome P-450 beta NF-B and P-450ISF-G are both involved in the detoxication of all three of the dinitropyrenes in rat liver microsomes. In a series of assays done with various human liver microsomal preparations, the inactivation of the three dinitropyrenes was not correlated to each other at all. Correlation analysis and inhibition studies with 7,8-benzoflavone and antibodies indicate that human cytochrome P-450 enzymes in the IA family are most effective in detoxicating this compound; the contribution of cytochrome P-450PA (P-450 IA2, the phenacetin O-deethylase) is deemed more important, but a role for the small amount of cytochrome P1-450 (P-450 IA1) in the liver cannot be ruled out. In contrast to the case of 1,3-dinitropyrene, the inactivation of 1,6-dinitropyrene is well correlated with levels of cytochrome P-450NF (P-450 IIIA4, nifedipine oxidase) and its catalytic activities. The inactivation of 1,8-dinitropyrene was not correlated with any of the above parameters and only correlated with the conversion of benzo(a)pyrene to its 3-hydroxy and 4,5-dihydrodiol products, for which the principal enzymes involved in human liver are unknown. Thus, distinct human cytochrome P-450 enzymes are involved in the detoxication of different dinitropyrene congeners, and the situation appears to contrast with that in rat liver.
A new restriction endonuclease (ENase), PshAI, has been isolated from Plesiomonas shigelloides 319-73, an organism that causes food poisoning in humans. The enzyme was stable and produced a yield of 410 units/g of cells. In the presence of 10 mM MgCl2, PshAI recognizes and cleaves the nucleotide sequence 5'-GACNN/NNGTC, producing blunt ends. PshAI will be useful for structural analysis and molecular cloning of DNA, because no ENases recognizing sequence GACNNNNGTC have been previously described.
The normal development of vascular and lymphatic capillaries in the right ventricular septomarginal band of the sheep heart was studied in 9 fetuses aged 60-143 days (term = 147 days), 14 lambs aged 1 day to 16 weeks, and 3 adults. Tissue was fixed by perfusion and examined with light and transmission electron microscopy. The septomarginal band is composed of working myocardium and a well-defined peripheral bundle of Purkinje cells. Vascular capillaries of the working myocardium were closely apposed to myocardial cells. By contrast, vascular capillaries of the Purkinje bundle were situated within the connective tissue sheath and septa, at variable distances from the Purkinje cells. After birth, the capillaries of the Purkinje bundle were also found in grooves and tunnels within the Purkinje strands. The ultrastructure of fetal vascular capillaries associated with myocardial and Purkinje cells was initially similar, and characterized by an abundance of synthetic organelles in endothelial cells and pericytes. However, after 115 days in utero, capillary endothelium with diaphragmed fenestrae, 40-60 nm in width, were observed within the Purkinje bundle. The fenestrae attained an average frequency of 1 per 11 capillary cross sections just before term, and this was maintained in lambs and adults. The ultrastructure of lymphatic capillaries, which were not observed in the septomarginal band until just before term, changed little during development.