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Biomedical subjects

H Maeda

Publications and source records attributed to H Maeda.

At least 955 records · Page 53Linked to original sources
PubMed1988

Immunocytochemical study on the ultrastructural localization of human-type ABO (H)-blood group activities in a macaque (Macaca irus).

The immunocytochemical study on the ultrastructural localization of human-type ABO(H)-activities in a crab-eating macaque (Macaca irus) was carried out by using postembedding and immuno-gold staining method. The tissue specimens examined were the esophagus, stomach (St), small intestine (Si), large intestine, liver, kidney, and pancreas. The specimens from these organs and submandibular gland (Sg) of a human (O-group) were used as staining reaction controls. Primary and secondary antibodies were commercially obtained mouse monoclonal anti-A, -B, -H (IgM), and goat anti-mouse IgM labeled with colloidal gold particles (luminal diameter 20 nm), respectively. The results were as follows: (1) In macaque specimens, only A-activity could be observed as the location of gold particles on the peripheral rim of serous secretory granules (Sg) and of epithelial cells (esophagus), the mucous droplets in epithelial cells and brush border (St, Si), the intracellular secretory canaliculi [ISC (St)] and the zymogen granules and secretory ducts (pancreas). Gold particles could be also noted at the Golgi apparatus and nascent secretory granules. (2) By periodic acid-thiocarbohydrazide-osmium tetroxide (PA-TCH-OS) reaction, hexose-rich neutral mucopolysaccharides were noted on the peripheral rim of serous secretory granules (Sg), the mucous droplets (St, Si), the ISC (St), and the brush border (Si). Such a distributional pattern corresponded well with that of gold particles, indicating that the substances were responsible for ABO(H)-activities.

ABO Blood-Group System↗
PubMed1988

Immunohistochemical study of blood group activities in the alimentary canal in normal and pathologic conditions with reference to the nature of epithelial mucopolysaccharides.

ABO(H)- and Lewis-activities in the human alimentary canal were investigated by the avidin-biotin-peroxidase complex method using commercial mouse monoclonal antibodies in order to clarify (1) the changes apparent in these activities in carcinoma of the digestive tract or premalignant intestinal metaplasia of the stomach and (2) the relationship of the activities to the histochemical properties of epithelial mucins examined by Alcian blue (pH 2.5)/periodic acid-Schiff (PAS) double staining. In intestinal metaplasia, ectopic goblet cells showed various degrees of ABO(H)-activities according to the PAS stainability of mucins and revealed Lea-activity even in a Le(a-b+) group. In carcinoma of the alimentary canal, ABO(H)- and Lewis-activities compatible with the donors' blood groups were located mainly at the PAS-positive cell surface, and in the Golgi bodies and secretions. It was thus concluded that quantitative and/or qualitative changes in blood group activities were closely associated with those of epithelial mucopolysaccharides.

ABO Blood-Group System↗
PubMed1988

Detection of muscular ventricular septal defect by the phase image.

A case of muscular ventricular septal defect shown by the phase image derived from Fourier analysis of gated equilibrium radionuclide angiocardiography is presented. The diagnostic feature of the defect on the phase image was a marked phase delay localized mainly in the trabecular portion of the right ventricle. This characteristic finding seemed to be caused by the left to right shunt flow through the defect located in the muscular portion of the interventricular septum.

Heart Septal Defects, Ventricular↗
PubMed1988

Taq I-generated HLA-DQ alpha polymorphism in Japanese patients with narcolepsy.

Taq I-generated HLA-DQ alpha restriction fragment length polymorphism was examined in Japanese patients with narcolepsy. All patients were DR2 positive and shared a 6.0 kb fragment, although this fragment was found only in 54% of the healthy DR2-positive Japanese. This finding added the DQ alpha gene to the list of candidates for the possible narcolepsy-susceptibility gene. In contrast, there was no complete association between narcolepsy and DX alpha restriction fragment length polymorphism. These findings suggest that a narcolepsy-susceptibility gene is located closer to the DQ locus than to the DX locus.

Chromosomes, Human, Pair 6↗
PubMed1988

Experimental study on diaphragm fatigue during diaphragm pacing.

An experimental study was performed to determine the main site of fatigue associated with diaphragm pacing. Using 24 mature mongrel dogs, weighing 7.5 to 12.7 kg, direct phrenic nerve pacing was conducted from the right cervical area at three different respiration rates, 37 (Group 1, n = 6), 25 (Group 2, n = 6) and 12 (Group 3, n = 6) times per minute, under fixed stimulation conditions (pulse duration, 200 microseconds; frequency, 25 Hz; pulse train repetition time, 1.2 sec). Diaphragm fatigue was defined as the reduction in transdiaphragmatic pressure (Pdi) to less than or equal to 60% of the initial value. In each animal, tidal volume (Vt), induced muscle action potential (Edi), conduction time (CT) and electrical current (E) between two electrodes were examined at various periods until fatigue. In addition, after fatigue, aminophylline (10 mg/kg) was injected and each parameter was observed for an additional 45 min. In 10 animals, the polarity of stimulation was changed from anodal to cathodal current after fatigue and changes in Pdi and Edi were examined. The time to fatigue was 70 +/- 20 min for Group 1, 149 +/- 48 min for Group 2, and 371 +/- 97 min for Group 3, showing a significant stimulation rate dependency (P less than 0.05). Vt and Edi showed a significant decrease (P less than 0.05) at fatigue in all of the groups. However, no significant differences of CT and E were seen between pre- and postfatigue values. Pdi and Edi did not change even when polarity was changed after fatigue. Following administration of aminophylline, Pdi showed a significant (P less than 0.05) increase over time in all groups: 19.8 +/- 13.5% at 5 min, 23.0 +/- 13.5% at 15 min, and 16.2 +/- 14.9% at 30 min for Group 1; 23.6 +/- 11.6% at 5 min, 27.3 +/- 15.5% at 15 min, and 19.0 +/- 16.1% at 30 min for Group 2; and 29.9 +/- 21.1% at 5 min, 29.5 +/- 18.6% at 15 min, 22.3 +/- 13.8% at 30 min, and 15.5 +/- 13.4% at 45 min for Group 3. In contrast, administration of aminophylline caused no significant changes in Edi. Based upon the finding that aminophylline was significantly effective at the time of diaphragm fatigue, it is concluded that fatigue of the muscle itself constitutes one of the contributing factors for the fatigue phenomenon associated with diaphragm pacing.

Action Potentials↗
PubMed1988

Stability of the folded-chain beta-structure of a homopolypeptide based on time-resolved potentiometric titrations.

The standard free energy change of the unimolecular conversion between the folded-chain beta-structure and random coil of uncharged poly(S-carboxymethyl-L-cysteine) was evaluated from the potentiometric titration curves extrapolated to zero time to reduce the effect of aggregation which occurred at slower rates than chain folding for most degrees of ionization. To reduce the remaining contribution from the aggregation, the results obtained at finite concentrations were further extrapolated to zero polymer concentration. A value of -(400 +/- 100) cal/mol was obtained for a sample of chain length 630. From the titration curves at the aggregation equilibrium, the total free energy change of the whole solution associated with the same conversion was determined. The contribution made by aggregation to the stability was determined from the difference between these two quantities, which turned out to be comparable with that from the unimolecular conversion.

Drug Stability↗
PubMed1988

Prediction of postoperative respiratory failure in patients undergoing lung resection for lung cancer.

To evaluate the correlation between predicted postoperative lung function and postoperative respiratory morbidity, 156 patients with lung cancer who underwent resection were classified into four groups based on the degree of postoperative problems: Group 1--no problems (116 patients); Group 2--retention of sputum or atelectasis requiring bronchofiberscopy two or more times (17 patients); Group 3--tracheostomy or mechanical ventilation for more than 2 days or both (14 patients); and Group 4--postoperative death (9 patients). The mean ages of Groups 2, 3, and 4 were significantly (p less than 0.05) higher than the mean age of Group 1. The predicted postoperative lung function (F) was assessed by the formula F = [1-(b-n)/(42-n)] x f, where f is the preoperative vital capacity or forced expiratory volume in one second, b is the number of subsegments of the resected lung lobe, and n is the number of subsegments obstructed by the tumor, which was assessed by the findings on the chest tomogram, on the bronchogram, at bronchofiberscopy, or a combination of these. The total number of subsegments was assumed to be 42. The predicted postoperative % FEV1 was 65.1 +/- 19.3% in Group 1,55.3 +/- 10.6% in Group 2,37.6 +/- 12.1% in Group 3, and 42.3 +/- 18.4% in Group 4. It was significantly (p less than 0.05) different between all the groups except between Groups 3 and 4. All 10 patients with a predicted postoperative % FEV1 of less than 30% were in Groups 3 and 4. We conclude that special attention to postoperative management is needed for patients whose predicted postoperative %FEV1 is lower than 30%.

Aged↗
PubMed1988

Postoperative erythrodermia (POED), a type of graft-versus-host reaction (GVHR)?

Postoperative erythrodermia (POED) is a rare disease appearing several days after surgery for which blood transfusion has been required, characterized by erythrodermia, fever, pancytopenia, hepatic insufficiency or diarrhea. Most affected patients die within four weeks. The etiology remains unknown, but some assume it to be a type of graft-versus-host reaction (GVHR) caused by transfused lymphocytes. In this study, skin biopsies taken from 9 POED patients were examined to clarify whether POED is a type of GVHR. In seven samples, changes compatible with GVHR, such as lymphocyte infiltration in the basal layer and occasional eosinophilic or vacuolar degeneration of the epidermal cells, with occasional satellitosis, were noted. Immunopathologically, infiltrating lymphocytes mostly expressed suppressor/cytotoxic T cell markers like those in GVHR. Meanwhile, immunostaining with anti-HLA-A type specific antibodies failed to differentiate infiltrating lymphocytes from host cells. Thus, the present morphologic and in vivo marker study suggested POED to be a type of GVHR, while in vivo HLA-A typing showed two contradictory possibilities: first, that POED is a GVHR in which major histocompatibility antigen-matched donor lymphocytes attack host cells, and secondly that POED is not a GVHR, the infiltrating lymphocytes being of host origin.

Adult↗
PubMed1988

Characterization of 73 kDa thiol protease from Serratia marcescens and its effect on plasma proteins.

The 73-kDa protease (73K protease) was purified from a clinical isolate of Serratia marcescens kums 3958. The purified protease appeared homogeneous by sodium dodecyl sulfate polyacrylamide gel electrophoresis in the presence or absence of 2-mercaptoethanol. The protease is active in a broad pH range with maximum activity at pH 7.5-8.0. The protease appeared to be a thiol protease, since it was inhibited by sulfhydryl reactive compounds such as p-chloromercuribenzoic acid, fluorescein mercuric acetate (FMA), iodoacetamide, and N-ethylmaleimide, and the protease activity was enhanced by various reducing agents such as cysteine, glutathione, 2-mercaptoethanol, and dithiothreitol. The protease contained 2 mol of free sulfhydryl residues per mol of protease. When the protease was reacted with FMA, a maximum of 2 mol of FMA per mol of enzyme was found reacted, based on fluorescence quenching in which the enzyme inactivation was paralleled linearly with the loss of both SH groups. This indicates possible equal involvement of the two thiol groups for the enzyme activity. The inactivation of the protease by FMA was partially restored by a dialysis in the presence of cysteine or dithiothreitol. The protease was not inhibited by high molecular weight kininogen but was inhibited by alpha 2-macroglobulin. The protease bound stoichiometrically to alpha 2-macroglobulin with 1:1 molar ratio and 25% activity remained constant even after the addition of 4 molar excess of alpha 2-macroglobulin. The protease extensively degraded IgG, IgA, fibronectin, fibrinogen, and alpha 1-protease inhibitor.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1988

Somatic mutation in peripheral lymphocytes of former workers at the Okunojima poison gas factory.

The former workers at the Okunojima poison gas factory comprise a high risk group for malignant tumors such as respiratory tract cancer. Demonstration of injury to somatic cell genes in this group may provide important data for evaluating the association between mustard gas and malignant tumors. So we measured the frequency of T lymphocytes lacking the hypoxanthine guanine phosphoribosyl transferase (HGPRT) activity, by cloning with interleukin 2 (IL2). In this study, we performed cloning of T lymphocytes lacking the HGPRT activity using recombinant IL2 (rIL2) and observed an increased frequency of somatic mutation in poison gas workers who had had more chances to be exposed to mustard gas and those who had worked for a longer period. This result suggested that inhalation of small amounts of mustard gas damaged somatic cell genes, resulting in carcinogenesis.

Aged↗
PubMed1988

Involvement of the kinin-generating cascade in enhanced vascular permeability in tumor tissue.

Enhanced vascular permeability in tumor tissue has profound pathological consequences in tumor biology. However, details of the mechanism involved are not clear. The present work on tumor vascular permeability has led to the following three findings. (i) Ascitic tumor fluid contained kinin (about 1-40 ng/ml), which is known to enhance vascular permeability and induce pain in vivo. (ii) Kinin is generated via the kallikrein-dependent cascade in the ascitic tumor fluid. By blocking this kinin-generating cascade with Kunitz-type soybean trypsin inhibitor the formation of ascites was suppressed. (iii) Blocking of kinin-degrading enzymes (kininases I and II) by an appropriate kininase inhibitor (e.g., captopril) may result in increased permeability, leading to accumulation of the ascitic fluid. This phenomenon was verified by an about 1.2-1.5 fold increase in leakage of 51Cr-labeled bovine serum albumin into the ascites when kininase inhibitors had been administered orally 30 min before intravenous administration of the bovine serum albumin.

Animals↗
PubMed1988

Platelet peroxidase-positive blast cells in transient myeloproliferative disorder with Down's syndrome.

Transient myeloproliferative disorder accompanied by Down's syndrome has been characterized as exhibiting self-limiting haematological abnormalities. We studied six patients suffering from this disorder in order to clarify the biological nature of their blast cells. Metaphases of leucocytes stimulated with phytohaemagglutinin (PHA) showed trisomy 21 in all patients except one. The exception was constitutionally trisomy 21 mosaic (46,XY = 89/47,XY,+21 = 11). However, metaphases from the peripheral blood cells (blast cells: 70%) without PHA stimulation showed exclusively trisomy 21. Simultaneous examination for morphology and chromosomal analysis on single colonies revealed that granulocyte-macrophage (GM) colonies and an erythroid colony contained only cells with the trisomy 21 karyotype. The blast cells showed positive reactions for platelet peroxidase (PPO) and with monoclonal antibodies against platelet-megakaryocyte antigen (TP 80 and TP 82). In methylcellulose and liquid culture systems, high plating efficiencies were observed, and mainly mature basophils containing histamine developed in the presence of PHA-stimulated leucocyte conditioned medium (PHA-LCM). In vivo, mature neutrophils, basophils, eosinophils or megakaryocytes coexisted with PPO-positive blast cells in the peripheral blood of some patients with this disorder. These findings suggest that transient myeloproliferative disorder is characterized by a proliferation of PPO-positive blast cells with trisomy 21, although some heterogeneity may be seen.

Blood Platelets↗
PubMed1988

Chemical modification of superoxide dismutase. Extension of plasma half life of the enzyme through its reversible binding to the circulating albumin.

Protection of organisms from oxidative stress is one of the major prerequisites for aerobic life. Since intravenously injected Cu++/Zn++-type superoxide dismutase (SOD) rapidly undergoes renal glomerular filtration and appears in urine in its intact form, its clinical use as a scavenger for superoxide radicals has been highly limited. To test whether reversible interaction of SOD with plasma albumin might decrease the rate of disappearance of the enzyme from the circulation, the lysyl residues of the human erythrocyte-type enzyme were covalently linked with poly-(styrene-co-maleic acid) butyl ester (SMA) via amide linkage. Affinity chromatographic analysis by an albumin-Sepharose column revealed that the enzyme samples labeled with SMA (SMA-SOD) tightly bound to the column, while unmodified SOD was eluted in the unbound fractions. SMA-SOD bound to the column could be eluted by the buffer solution containing 0.1% sodium dodecylsulfate. In vivo analysis revealed that intravenously administered SMA-SOD circulated bound to albumin with an extremely long half-life (6 h), while unmodified SOD rapidly underwent renal glomerular filtration with a plasma half-life of 4 min. Thus, SMA-SOD may effectively dismutase superoxide radicals in the circulation.

Animals↗
PubMed1988

An electron microscopic examination of age-related changes in the rat liver. The influence of diet.

The influence of age and diet on the ultrastructure of hepatocytes is reported. The following dietary manipulations were investigated: Group 1, fed ad libitum a diet containing 21% protein; Group 2, fed a similar diet but restricted to 60% of the intake of Group 1 from 6 weeks of age onwards; Group 3, restricted from 6 weeks to 6 months of age and thereafter fed ad libitum; Group 4, restriction started at 6 months of age; Group 5, fed ad libitum a diet containing 12.6% protein. In all groups the size of hepatocytes was found not to increase during adult life. The size of hepatocytes in Groups 2 and 4 was the same as or larger than that of the other groups; thus food restriction resulted in a decreased number of hepatocytes. Changes in the structure of some organelles and the accumulation of lipofuscin granules occurred with advancing age and the extent of these age-related changes was less in Groups 2 and 4 than in the other groups. These morphologic findings in conjunction with our previously reported metabolic findings provide a new view of the action of food restriction on the aging process.

Aging↗
PubMed1988

In vitro activities of T-3262, NY-198, fleroxacin (AM-833; RO 23-6240), and other new quinolone agents against clinically isolated Chlamydia trachomatis strains.

The in vitro activities of three newly developed quinolone drugs (T-3262, NY-198, and fleroxacin [AM-833; RO 23-6240]) against 10 strains of clinically isolated Chlamydia trachomatis were assessed and compared with those of other quinolones and minocycline. T-3262 (MIC for 90% of isolates tested, 0.1 microgram/ml) was the most active of the quinolones. The NY-198 and fleroxacin MICs for 90% of isolates were 3.13 and 62.5 micrograms/ml, respectively.

Anti-Infective Agents↗
PubMed1988

Cleavage of immunoglobulin G (IgG) and IgA around the hinge region by proteases from Serratia marcescens.

Seven clinical and two nonclinical isolates of Serratia marcescens were examined for their ability to produce extracellular enzymes that cleave immunoglobulin G (IgG) and IgA molecules. All seven clinical isolates excreted a large amount of a 56-kilodalton (kDa) protease (56K protease) and small amounts of a 60-kDa and a 73-kDa protease (60K and 73K proteases, respectively) in culture medium during growth. All purified proteases cleaved IgG and IgA effectively if the level of protease production exceeded 2 to 5 micrograms/ml. The proteolytic activity in the culture supernatant was inhibited by about 85% by a chelating agent (EDTA), which indicated that the major immunoglobulin-cleaving enzyme is the metalloprotease(s) reported previously. Immunological quantification of proteases by single radial immunodiffusion showed similar results: the amount of 56K protease was about 65% and those of the 60K and 73K proteases were about 20 and 5%, respectively. Incubation for 3 h at 37 degrees C was required to generate immunoreactive Fab and Fc fragments. Further analysis of the cleavage products of IgG or IgA demonstrated that the 56K protease, as well as the 60K and 73K proteases, cleaves only the heavy chain of these immunoglobulins near the hinge region to generate Fab and Fc fragments. The susceptibilities of the subclasses of IgG and IgA to the 56K protease were as follows: IgG3 greater than IgG1 greater than IgG2 greater than IgG4 and IgA1 greater than IgA2. IgG2, IgG4, and IgA2 were relatively resistant to the 56K protease.

Humans↗
PubMed1988

Effects of intrauterine treatment on nonimmunologic hydrops fetalis.

In 44 cases with nonimmunologic hydrops fetalis (NIHF), perinatal management was performed based on our protocol. Twenty-one cases were treated by albumin and/or packed red blood cell (PRC) injection into the fetal abdominal cavity, and 8 cases were treated by transplacental digitalization. Among the cases treated by albumin and/or PRC injection, 5 of 7 cases without pleural effusion recovered in utero, and all 5 cases are alive at the time of writing. However, of 14 cases with pleural effusion, none recovered in utero, and only 1 case is alive. Of 8 cases treated by transplacental digitalization, 2 cases recovered in utero, and 1 case is alive. All fetuses with congenital heart anomaly died. This evidence indicates that albumin and/or PRC injection into the fetal abdominal cavity is an effective procedure for in utero treatment of NIHF without pleural effusion, but suggests that in NIHF resulting from either congenital heart anomaly and/or heart failure, the survival rate may not be increased by transplacental digitalization.

Blood Transfusion, Intrauterine↗