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Biomedical subjects

H Maeda

Publications and source records attributed to H Maeda.

At least 865 records · Page 48Linked to original sources
PubMed1990

[A case of an operation for lung cancer after PTCA].

A 64-year-old lung cancer patient combined with angina pectoris was admitted to our hospital. Chest roentgenogram showed a coin lesion in the left upper lobe. Broncho-fiberscopic examination proved adenocarcinoma. Coronary angiography revealed 90% stenosis of the left circumflex artery. Percutaneous transluminal coronary angioplasty (PTCA) was done and resulted in success. Eight days after PTCA, left upper lobectomy for lung cancer was undergone. Postoperative course was uneventful. Compared with coronary artery bypass grafting, PTCA was very useful for the patient having malignant disease combined with angina pectoris because of little surgical stress and no delay of operation.

Adenocarcinoma↗
PubMed1990

[Clinical study of extracorporeal shock wave lithotripsy for 1000 patients with renal and ureteral stones].

Using a Dornier HM3 lithotripter, we treated 1,000 patients with renal and ureteral stones from April, 1986 to July, 1989. They consisted of 612 solitary stones (pelvic stones, 152; calyceal stones, 167; ureteral stones, 293), 265 multiple stones and 123 staghorn calculi (complete, 48; partial, 75). The overall rate of the auxiliary procedure was 59.3% (pre-operative, 47.9%; post-operative, 11.4%). Pre-operative procedure included 430 catheterizations, 26 percutaneous nephrostomies (PNSs) and 23 pyelograms . Post-operative procedure included 69 transurethral lithotripsy , 21 PNSs, 26 percutaneous nephrolithotripsy (PNLs), 6 meatotomy , 5 chemolysis and 1 open surgery. 484 (68.3%) in 709 good follow-up cases were stone-free at the time of 3 months since the first extracorporeal shock-wave lithotripsy (ESWL). Complications were pain (34.8%), fever (4.3%), pain & fever (8.5%), subcapsular hematoma (0.1%) and ureteral obstruction (0.1%). Thus, ESWL is considered to be a useful means for renal and ureteral stones and in the case of large stone the combination therapy with PNL is more effective than ESWL-monotherapy.

Adult↗
PubMed1990

[An autopsy case of sudden death due to hyperthyroidism].

A rare autopsy case of death due to thyroid crisis is reported. A 45-year-old lean woman with pigmentation of the skin was found dead at the seaside. The autopsy findings were as follows: The enlarged thyroid gland (35.5 g) had a histological finding of diffuse hyperplastic goiter (hyperthyroidism). The thymus (28.5 g) was enlarged and parenchymatous. The lymphocytes in the thymus and spleen were conspicuously proliferated, probably due to secondary adrenal cortex insufficiency. The adrenal cortex was slightly atrophic. Hemosiderin-laden macrophages in the lung, and centrilobular necrosis, microscopic bleeding, fibrosis, and nodular regenerative hyperplasia of the liver indicated the persisted heart failure. A small pericardial scar was found at the right ventricle of the heart (280 g), and the histological finding of the heart was only congestion. Acetone was detected in a relatively high concentration in the blood (72 micrograms/ml), urine (139 micrograms/ml), bile (32 micrograms/ml) and gastric contents (38 micrograms/g), probably due to metabolic disorder from thyroid crisis. In conclusion, the cause of death was diagnosed as sudden death due to thyroid crisis from hyperthyroidism.

Death, Sudden↗
PubMed1990

Cerebral hemodynamics in patients with chronic obstructive carotid disease by rCBF, rCBV, and rCBV/rCBF ratio using SPECT.

To evaluate cerebral hemodynamics, 21 patients with chronic occlusion or severe stenosis of the internal carotid or middle cerebral artery with normal or only lacunar infarction on x-ray CT were studied using single photon emission computed tomography (SPECT). We measured rCBV with 99mTc erythrocytes after rCBF with 133Xe, and calculated rCBV/rCBF. rCBF and rCBV of the 25 affected hemispheres were classified as (a) patients with normal rCBF [type I (n = 7) and type II (n = 3)]; (b) patients with decreased rCBF [type III (n = 6) and type IV (n = 9)]. These two groups then could be subdivided according to findings of rCBV, normal, and increased blood volumes. rCBV/rCBF increased as the cerebral perfusion pressure dropped from type I to type III. In type IV, other situations but cerebral autoregulation could be assumed. rCBV/rCBF signifies vascular mean transit time. Type III (high rCBV/rCBF) assumed as the increased OEF, misery perfusion as reported in PET. We propose rCBF, rCBV and rCBV/rCBF using SPECT can be an index for cerebral circulatory reserve.

Arterial Occlusive Diseases↗
PubMed1990

[Three dimensional model constructed from Tl-201 myocardial SPECT in combination with bull's-eye mapping].

Three dimensional images (3D Model) and Bull's-eye maps of Tl-201 stress and redistribution scintigrams were reconstructed from average distances and relative accumulations per unit area. 3D Models viewed from different angles were studied in cine mode, in conjunction with the Bull's-eye map. The accumulations of Tl-201 were classified into five different ranks. ROC curves for 3D Model were computed. The coronary artery stenoses estimated by 3D Model were found to have statistical correlations with the results of coronary angiography, in one and two coronary vessel disease, but not in three. Concerning the areas and the locations of abnormal Tl-201 distributions, 3D Model images offer more comprehensible informations than the conventional Bull's-eye method, especially around the left ventricular outlet.

Adult↗
PubMed1990

[A case report of widely recurrent carcinoid tumor of the thymus].

We performed wide resection of recurrent carcinoid tumor of thymus. A 62-year-old male patient admitted to our department because of swelling of anterior chest wall. He had received extirpation of thymic carcinoid tumor 5 years ago and he was pointed out large mass formation in anterior mediastinum before admission. Wide resection of tumor including pericardium, chest wall, left lung and left brachiocephalic vein was performed. Left brachiocephalic vein was reconstructed and pericardium was replaced with Gore-Tex patch. The carcinoid tumor of thymus sometimes invade to adjacent organs and is apt to recur long time after first operation.

Carcinoid Tumor↗
PubMed1989

Pathogenic potentials of bacterial proteases.

Six separate molecular mechanisms for pathogenesis attributed to bacterial proteases are described. (I). Enhancements of vascular permeability and edema formation which result from the activation of kinin generating cascade such as Hageman factor by the proteases. (II). Degradation of defense oriented proteins including IgG and IgA as well as destruction of structural matrices such as fibronectin, proteoglycan and collagen. (III). Inactivation of complement system and generated chemotactic factor from C3 and C5. (IV). Degradation of regulatory plasma protease inhibitors (serpins) including alpha 1-protease inhibitor, alpha 2-macroglobulin (alpha 2M), C1-esterase inhibitor, alpha 2-antiplasmin and antithrombin-III. (V). The protease forms a transitory stable enzyme/inhibitor(alpha 2M) complex. It binds to and internalizes into the cells which possess alpha 2M-receptor such as fibroblasts via the alpha 2M-receptor, and the protease activity is regenerated in cells, and subsequently intracellular integrity is destroyed resulting in cell killing. (VI). The serratial 56 kDa (56K) protease is found to potential viral yield 100 fold more when influenza virus infected mice were subjected to administrations of this protease intranasally. This results in rapid and much elevated lethality.

Animals↗
PubMed1989

Nation-wide study of lethal mid-line granuloma in Japan: frequencies of wegener's granulomatosis, polymorphic reticulosis, malignant lymphoma and other related conditions.

Lethal mid-line granuloma (LMG) is a clinical term, and it is histologically composed of Wegener's granulomatosis (WG), polymorphic reticulosis (PR), and malignant lymphoma (ML). WG is an inflammatory disease, and PR and ML are considered to represent a neoplastic proliferation of lymphoreticular cells. In the present report, a nation-wide study on LMG in Japan is compared with a study from the UK, to examine differences in frequencies of each disease in Eastern and Western countries. A total of 340 cases of LMG were examined. On the basis of histological and clinical findings, these cases were categorized as 68 WG, 129 PR, 92 ML, 44 chronic inflammation not specified, and 7 other related conditions. The crude frequencies of WG, PR, and ML per 100,000 outpatients of ENT clinics in Japan and England were 4, 8 and 6, respectively and 8, 4 and I, respectively. The predominance of malignant lymphoproliferative diseases to WG in Japan (3.5:1) was in marked contrast to the situation in the UK (1:1.6). A review of the pertinent literature suggests a clustering of malignant lymphoproliferative diseases of the nose among Mongolian ethnic groups.

Adolescent↗
PubMed1989

Activation of hageman factor and prekallikrein and generation of kinin by various microbial proteinases.

Activation of the Hageman factor-kallikrein-kinin system by serratial 56-kDa proteinase was previously demonstrated (Matsumoto, K., Yamamoto, T., Kamata, T., and Maeda, H. (1984) J. Biochem. (Tokyo) 96, 739-749; Kamata, R., Yamamoto, T., Matsumoto, K., and Maeda, H. (1985) Infect. Immun. 48, 747-753). To investigate whether the activation of the system is specific for 56-kDa proteinase or is found similarly with other microbial proteinases, 11 proteinases of microbial origins were studied; the 56-kDa proteinase was the control. For in vitro studies, activation of guinea pig Hageman factor and prekallikrein was examined in purified systems as well as in plasma as a zymogen source. Specific antibodies and inhibitors confirmed the activation steps of the cascade. In the in vivo study the enhancement of vascular permeability in guinea pig skin and its sensitivity to inhibitors of activated Hageman factor, plasma kallikrein, or a kininase were examined. The results from the in vivo experiments were consistent with those in vitro. Taking all the data together, we classified the 11 microbial proteinases into three groups as follows: 1) Serratia marcescens 56-, 60-, and 73-kDa proteinases, Pseudomonas aeruginosa alkaline proteinase and elastase, and Aspergillus melleus proteinase (this group activated Hageman factor but not prekallikrein); 2) Vibrio vulnificus proteinase, subtilisin from Bacillus subtilis, and thermolysin from Bacillus stearothermophilus (this group activated both Hageman factor and prekallikrein); 3) Streptomyces caespitosus proteinase and V8 proteinase from Staphylococcus aureus (this group activated neither Hageman factor nor prekallikrein, but generated kinin from high molecular weight kininogen directly).

Animals↗
PubMed1989

Putative amino acid sequence of HLA-DRB chain contributing to rheumatoid arthritis susceptibility.

The association between HLA-DR4 and rheumatoid arthritis (RA) has been established in many ethnic groups. To clarify the determinant of susceptibility to RA, a polymorphic segment of the HLA-DRB gene was amplified in vitro by polymerase chain reaction and analyzed with oligonucleotide probes specific for the HLA-DR4 DNA sequences. A particular sequence encoding amino acids Gln70-Arg71-Arg72-Ala73-Ala74 showed a strong association with RA (p less than 0.005, relative risk 6.0). This amino acid sequence occurs in the DRB molecules with three RA-associated specificities, DR4/Dw14, DR4/Dw15, and DR1. DR4/Dw4, which is common in Caucasian RA patients, has a strikingly similar amino acid sequence Gln70-Lys71-Arg72-Ala73-Ala74 in terms of polarity and charge profiles. Other RA nonassociated sequences differ from this sequence by at least one amino acid substitution that causes the change of the net charge. The composition of amino acid residues at the positions 70-74 may play a crucial role in the pathogenesis of RA.

Amino Acid Sequence↗
PubMed1989

Oxygen radicals in influenza-induced pathogenesis and treatment with pyran polymer-conjugated SOD.

The pathogenicity of influenza virus infection in the mice involves, at least in part, overreaction of the immune responses of the host rather than a direct effect of virus multiplication. Xanthine oxidase, which is responsible for the generation of oxygen free radicals, was elevated in serum and lung tissue of mice infected with influenza virus. To test the theory that oxygen-free radicals are involved in pathogenesis, free radicals were removed by injecting superoxide dismutase (SOD), a specific superoxide radical scavenger, which was conjugated with a pyran copolymer. The conjugate protected mice against a potentially lethal influenza virus infection if administered 5 to 8 days after infection. These findings indicate that oxygen radicals are important in the pathogenesis of influenza virus infection, and that a polymer-conjugated SOD has therapeutic potential for this virus infection and other diseases associated with free radicals.

Animals↗