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Biomedical subjects

M Endo

Publications and source records attributed to M Endo.

At least 541 records · Page 30Linked to original sources
PubMed1993

[A study of the utility of the MR image for the diagnosis of thymic tumors--imaging and pathologic correlation].

MR imaging was performed in 25 patients with thymic tumors (five with non-invasive thymomas, 15 with invasive thymomas, and five with thymic carcinomas), and the MR imaging appearance was compared with the pathological findings. Non-invasive thymomas showed generally oval or round masses with well-defined margins and homogeneous intensity on T1- and T2-weighted images. Invasive thymomas showed a multinodular appearance in 79% (11/15) of cases, and an internodular difference in signal intensity (IDSI) in 64% (7/11) on T2-weighted images. It was considered that the IDSI on T2-weighted images correlated pathologically with the hemorrhagic and/or necrotic areas and hyalinization. The IDSI seemed to be a characteristic finding of invasive thymomas. The histological findings and MR imaging appearance of thymomas were compared. The predominantly epithelial type showed a low incidence of nodular appearance but showed marked IDSI on T2-weighted images. Therefore, it is more likely that the predominantly epithelial type induced more varied intratumoral changes than other types. Extension of thymic carcinomas was similar to that of invasive thymomas on MR imaging, but thymic carcinomas showed no definite nodular appearance. In conclusion, MR images in thymic tumors were useful for not only determining the morphology of the tumor but also the tissue characteristics. Therefore, MR imaging can be a useful modality to correlate with the histological findings and biological behavior of thymic tumors.

Adult↗
PubMed1993

Effect of lentinan on lymphocyte subsets of peripheral blood, lymph nodes, and tumor tissues in patients with gastric cancer.

The effect of lentinan on lymphocyte subsets of peripheral blood, lymph nodes, and tumor tissues in gastric cancer patients was investigated. A 2-mg dose of lentinan was administered to 12 patients intravenously twice, the first at 3-9 days before and the second the day before surgery. The results were then compared with a control group without lentinan administration comprising 12 patients. Regarding peripheral blood and lymph nodes without metastasis, lymphocyte subsets defined with anti-CD3, anti-CD4, anti-CD8, anti-Leu7, and anti-Leu11 were analyzed by flow-cytometry. As for tumor tissues, lymphocyte subsets defined with anti-CD3, anti-CD4, anti-CD8, anti-Leu11, and anti-M3 were analyzed after immunohistochemical staining. There were no significant changes in the lymphocyte subsets of peripheral blood between the two groups. In the lymph nodes, the CD4 cell ratios increased; otherwise in regard to tumor-infiltrating lymphocytes (TILs), the number of CD4, Leu11 and LeuM3 cells showed a prominent increase. Therefore, lentinan was observed to produce different effects in accordance with the subjective organs.

Aged↗
PubMed1993

Depolymerization of hyaluronan by sonication.

High molecular weight hyaluronan (M(r) 400,000) obtained from human umbilical cord was depolymerized by sonication for 10 h into small molecules and finally into molecules of constant size (M(r) 11,000). The molecular size of the depolymerized hyaluronan was unaltered even under different conditions of sonication. After sonication, the main sugar residues at the reducing and non-reducing termini of depolymerized hyaluronan were N-acetylglucosamine (86%) and glucuronic acid (98%), respectively. Hyaluronans derived from rooster comb (M(r) 1 x 10(6)) and Streptococcus zooepidemicus (M(r) 1.2 x 10(6)) were depolymerized into molecules of different but characteristic sizes by sonication. On the other hand, neither chondroitin sulfate nor glycogen was depolymerized by sonication. These results suggest that high molecular weight hyaluronan may have some weak linkages related to N-acetylglucosamine in the chain, which are extremely sensitive to sonication. At present, however, the nature of these linkages is still unclear.

Animals↗
PubMed1993

Isolation of mucin from human hepatic bile and its induced effects on precipitation of cholesterol and calcium carbonate in vitro.

Biliary mucin was isolated from human hepatic bile, and its induced effects on the appearance time of cholesterol monohydrate crystals (nucleation time) and on the precipitation of calcium carbonate were studied in vitro to examine the possible significance of mucin for ductular gallstone formation. Mucin was isolated by gel filtration on Sepharose CL-4B and a subsequent CsCl density gradient ultracentrifugation. Mucin thus obtained had a high purity as shown by a high-molecular-weight band on SDS-polyacrylamide gel electrophoresis and by the compatible amino acid composition with mucin purified from the gallbladder. The mucin at as low a concentration as 100 micrograms/ml significantly shortened the cholesterol nucleation time in the supersaturated model bile, mimicking human hepatic bile. On the other hand, the addition of mucin inhibited calcium carbonate precipitation in vitro. Taking account of that both cholesterol and calcium salts are major constituents of ductular gallstones, we conclude that biliary mucin is likely to play an important regulating role in the formation of ductular stones.

Bile↗
PubMed1993

Enzymic determination of acidic glycoconjugates in human pancreatic juice.

Acidic glycoconjugates (glycosaminoglycans, sulfated glycopeptide, and sialoglycopeptide) were isolated by precipitation with cetylpyridinium chloride from human pancreatic juice after digestion with pronase. The acidic glycoconjugates were found exclusively in the proteinaceous precipitate that occurred during dialysis against a buffer of low ionic strength. The concentration of the acidic glycoconjugates in normal pancreatic juice was about 2.4 mg/L. The acidic glycoconjugates were characterized by electrophoresis on cellulose acetate membrane and chemical analysis before and after digestion with Streptomyces hyaluronidase, chondroitinase AC, chondroitinase ABC, and heparitinase. It was found that the major acidic glycoconjugates were heparan sulfate (39.3%), sulfated glycopeptide (34.4%), chondroitin sulfate (14.2%), and the minor ones hyaluronic acid (6.4%) and sialoglycopeptide (5.7%).

Chondroitinases and Chondroitin Lyases↗
PubMed1993

Simple measurement of glycosaminoglycan produced by cultured fibroblasts using 4-methylumbelliferyl beta-D-xyloside.

A simple and rapid method was devised for measurement of glycosaminoglycan produced by cultured cells. 4-Methylumbelliferyl-beta-D-xyloside was added to the medium of the cultured cells. After incubation, glycosaminoglycan, which was produced from 4-methylumbelliferyl-beta-D-xyloside as a primer and secreted into the medium, was separated by proteinase digestion, trichloroacetic acid treatment and ethanol precipitation. The glycosaminoglycan, bearing a fluorescent moiety at the reducing terminal, was electrophoresed on cellulose acetate membrane, and then the fluorescent band visible on the membrane was extracted. The fluorescence of the band was measured, and from this the amount of glycosaminoglycan was estimated. Using this method, it was possible to quantify a very small amount of glycosaminoglycan with relatively high sensitivity without employing a radioisotope. This method was applied for determination of glycosaminoglycan produced by cultured fibroblasts from human uterine cervix, and also the effect of a hormone on glycosaminoglycan production. It was found that uterine cervical fibroblasts produced twice as much glycosaminoglycan as skin fibroblasts.

Carbohydrate Sequence↗
PubMed1993

Endoscopic resection as local treatment of mucosal cancer of the esophagus.

Limited surgery is indicated for mucosal cancer of the esophagus without lymph node metastasis. Esophagectomy without thoracotomy and endoscopic resection are carried out as the operative modalities of reduced surgery. Mucosal cancer less than 3 cm in size without any nodal involvement is suitable for endoscopic resection. The maneuver of endoscopic resection of esophageal cancer is carried out as follows; a transparent covering tube with a small channel for electric snare forceps is used, a forward-viewing endoscopic is inserted inside the covering tube, the grasping forceps of the mucosa is inserted through the working channel of the endoscope, the mucosa is grasped by forceps through the opening of snare forceps, and is snared and resected by electric cauterization. The maneuver is repeated. No postoperative complication has ever been experienced. The mechanically induced ulcer down to the submucosal layer heals within a month.

Esophageal Neoplasms↗
PubMed1993

Age-related changes in proteoglycans of human ligamentum flavum.

Age-related changes in proteoglycans of human ligamentum flavum were studied using specimens obtained from patients divided into four age groups. The proteoglycans were purified by ion-exchange and gel-filtration chromatography. A low-molecular-weight proteoglycan with the same molecular size was present in all each age groups. Conversely, high-molecular-weight proteoglycan increased with advancing age. Properties of the sugar chains, glycosaminoglycans, in these proteoglycans were studied using cellulose acetate membrane electrophoresis and chondroitinase digestion. It was found that the high-molecular-weight proteoglycan consisted mainly of chondroitin 6-sulfate, whereas the low-molecular-weight proteoglycan consisted mainly of dermatan sulfate, although the ratio of chondroitin 6-sulfate increased with age. These results indicate that proteoglycans of human ligamentum flavum show changes in amount and composition with age.

Adolescent↗
PubMed1993

Mechanical circulatory support for postcardiotomy ventricular failure: the Heart Institute of Japan experience 1984-1992.

In the last 9 years, 30 patients received assisted circulation or a ventricular assist device after open-heart operations at the Heart Institute of Japan. After cardiovascular surgery, 9 of those patients underwent venoarterial bypass, 10 had biventricular bypass, 7 had left ventricular bypass, and the remaining 4 received a left ventricular assist device. Of the first 15 patients, only 3 (20%) were discharged from the hospital. In contrast, 7 (46.7%) of the last 15 patients were discharged without major complications. With respect to complications, bleeding and ventricular arrhythmia (immature weaning) decreased with low-heparinized isolated left ventricular supports. However, profound biventricular failure, infection, and multiple organ failure remain as possible complications with any type of assisted circulation. These results suggest that early application of circulatory support and appropriate selection of the mode of support and devices used are important for successful circulatory support.

Adult↗
PubMed1993

Percutaneous cardiopulmonary support as the second generation of venoarterial bypass: current status and future direction.

We have developed a new percutaneous cardiopulmonary support (PCPS) system in cooperation with Terumo Corporation, called the Emergency Bypass System (EBS). This preassembled system is unique in terms of its small priming volume (470 cc), fully automatic priming function, originally developed membrane oxygenator, and Capiox straight path centrifugal pump. The priming process takes only 5 min. We have used this system in 4 patients (all were male; mean age 56 years, range 35-73 years). The duration of assist ranged from 15 min to 210 h. Maximum bypass flow ranged from 2.2 to 3.6 L/min, systemic circulation was very well maintained, and urinary output was acceptable. Although the centrifugal pump was in good working condition, we had to change the oxygenator because of serum leakage 36 to 48 h after initiation of the assist. One patient was weaned from the PCPS, but died of brain death. The other patients could not be weaned from the PCPS. The cause of death in these patients was irreversible myocardial damage. Disseminated intravascular coagulopathy triggered by surgical trauma related to various procedures developed in 2 patients during assist and was the cause of cessation of the assist. Problems to be ratified and future directions in the EBS and PCPS were earlier introduction through the establishment of clear indications and endpoint, heparin coating, improvement in durability of the oxygenator, and cost.

Adult↗
PubMed1993

Development of the Terumo Capiox centrifugal pump and its clinical application to open heart surgery: a comparative study with the roller pump.

We have developed the Terumo Capiox centrifugal pump (CXP), which consists of a rotor having a unique straight-path design to reduce pump rotational speed without decreasing hydraulic efficiency. The CXP was tested in vitro for blood trauma with a specially designed test circuit using fresh bovine blood. The Biopump (BP) (Medtronic, Minneapolis, MN, U.S.A.) and the roller pump (RP) were used as controls. The CXP demonstrated the smallest elevation of free plasma hemoglobin compared with the BP and the RP. The CXP was then applied to cardiopulmonary bypass (CPB) in 10 patients (CXP group) who underwent elective coronary artery bypass grafting (CABG), and the results were compared with those for a comparable roller pump group (RP group). Free plasma hemoglobin level, platelet count, and serum beta-thromboglobulin (beta-TG) level were measured during CPB. There were no CXP-related complications nor hemodynamic abnormalities during CPB. The CXP group demonstrated less hemolysis and less platelet depletion than the RP group. Furthermore, the serum beta-TG level was significantly lower in the CXP group than in the RP group. The CXP showed excellent hemodynamic performance with less blood trauma both in vitro and in clinical application to open heart surgery. Thus, the CXP has significant potential to be safely applied to CPB for open heart surgery and circulatory support.

Animals↗
PubMed1993

Clinical experience of assisted circulation with a centrifugal pump at Tokyo Women's Medical College.

In postpericardiotomy patients, the use of pulsatile pumps is limited in a semielective fashion to patients whose postoperative marginal hemodynamics are expected preoperatively. Since 1989, 25 patients have undergone assisted circulation with a centrifugal pump: 15 (60%) were weaned from the pump, and 7 (28%) survived. In 1988, we heparin-coated the Bio-Pump using the Carmeda technique and developed a totally heparin-coated left heart bypass system together with heparin-coated cannulas and tubing. Four postpericardiotomy patients underwent left heart bypass with this system without heparin for 2 to 9 days. No thrombus was detected in the system. Left heart bypass with a centrifugal pump has been used as a supportive method in surgical repair of thoracic or thoracoabdominal aortic aneurysm. To overcome intraoperative hypothermia and hypoxia, we used a small membrane oxygenator with a heat exchanger in 11 patients, and postoperative recovery dramatically improved. We also developed a preassembled percutaneous cardiopulmonary support (PCPS) system with an automatic priming function using Terumo's straight path centrifugal pump and small membrane oxygenator in cooperation with the Terumo Corporation. This system was used in a patient with cardiogenic shock after acute myocardial infarction. The setup and priming took only 5 min, and 2.5-3.5 L/min of flow was obtained.

Adult↗
PubMed1993

Effects of ryanodine on the properties of Ca2+ release from the sarcoplasmic reticulum in skinned skeletal muscle fibres of the frog.

1. We studied the effects of ryanodine on the functions of the sarcoplasmic reticulum (SR) in skinned muscle fibres from Xenopus laevis. 2. Ryanodine treatment decreased the Ca2+ uptake capacity of the SR in a fixed Ca2+ loading condition. The extent of the decrease in the SR Ca2+ uptake capacity was closely correlated with the activity of the Ca(2+)-induced Ca2+ release (CICR) during the ryanodine treatment. This suggests, in agreement with the previous biochemical results, that ryanodine acts on the CICR channels when they are open. 3. The rate of Ca2+ leakage from the SR increased after ryanodine treatment. However, the leakage rate constants were independent of the degree of the loss of SR Ca2+ uptake capacity by the ryanodine treatment. This is inconsistent with the notion that the SR is a single uniform compartment and that the decline in the SR Ca2+ uptake capacity is a result of the increase in the Ca2+ leakage. 4. Partial recovery of the Ca2+ uptake capacity of the ryanodine-treated SR was observed when Ca2+ loading was carried out in the presence of 10 mM procaine. This indicates that procaine partially blocks the open-locked channels. 5. After Ca2+ loading in the presence of procaine, removal of procaine induced a rapid release of Ca2+ from the SR through the open-locked channels. This rapid release was dependent both on the adenine nucleotide concentration and on the Ca2+ concentration. Thus, the 'open-locked' CICR channels are still regulated by Ca2+ and adenine nucleotides.

Animals↗
PubMed1993

[Ca2+ release mechanism studied in single isolated smooth muscle cells].

This paper briefly reviews our current effort to study the Ca2+ mobilization mechanism in enzymatically dispersed single smooth muscle cells. Each single cell obtained from guinea pig taenia caeci possesses two types of Ca2+ stores, one (S alpha) with both Ca(2+)-induced and IP3-induced Ca2+ release mechanisms and the other (S beta) with only IP3-induced Ca2+ release mechanism. After depletion of S alpha either with ryanodine treatment or with caffeine pretreatment, carbachol failed to induce Ca2+ release, while intracellular application of IP3 did induce Ca2+ release. Our results suggest that the difference between the agonist- and IP3-induced responses can be resolved by obligatory involvement of positive feedback control of IP3-induced Ca2+ release in the agonist-induced Ca2+ release. Furthermore, we were able to demonstrate that the dose-response relation in single cells shows an all-or-none feature, which seems at least partly due to the feedback control of Ca2+ release. We discuss the reasons why graded dose-response relation is obtained in bundles of smooth muscles, while the response of single cells is an all-or-none type.

Animals↗
PubMed1993

[Cerebral and testicular myeloblastoma formation in relapsing acute myeloid leukemia (M1) with t(8;21)].

This paper reports a relapsed case of acute myeloid leukemia with intracranial, testicular and intestinal tumor formation. A-56-year-old male, diagnosed as M1 on September, 1988, entered complete remission on October 14, 1988, aided by JAL-SG and AML-85 regimen. Blast cells with Auer rods demonstrated 8;21 translocation lacking 11q with 30 of 30 analyzed bone marrow cells, and the following antigen pattern: CD5+, CD19+, CD33+, CD56+, HLA-DR+. After 4 courses of post remission therapy, the maintenance therapy was discontinued because of his liver dysfunction. He was discharged on May, 1989, and was seen as an out patient. He complained of left hemiplegia and was re-admitted on September 30, 1989. Though the bone marrow was in complete remission on September 4th, CT scan and MRI demonstrated intracranial tumor formation. Bone marrow relapse occurred on October 27th, eventually resulting in his death on November 18th. Autopsy showed intracranial, testicular and intestinal tumor formation and blast cell invasion into the liver, spleen and kidneys. We analyzed the characteristics of 14 cases with intracranial tumor formation previously reported. The focal neurological symptoms reflecting the intracranial tumor mass effect were considered to be important initial signs. CT scan was a useful tool for diagnosis. The average age of the 14 cases was 38, 9 and the male/female ratio was 9:5. Six of 9 cases, diagnosed by FAB classification, were M2 and one of the 6 cases in whom chromosomes of blast cells were examined had t(8;21). Though irradiation seemed effective for the reduction of tumor mass, the patients' prognosis was poor.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1993

Flow study of coronary-coronary bypass grafting.

Coronary-coronary bypass grafting was recently introduced for patients with either calcification of the ascending aorta or an inadequate length of graft. Flow in the coronary-coronary bypass graft and that in aortocoronary bypass to the same coronary bed was compared in eight mongrel dogs. Flow reserve of the proximal right coronary artery as a donor vessel to the coronary-coronary bypass graft was also measured. Both a coronary-coronary and aortocoronary bypass were constructed to the proximally ligated left anterior descending artery. The flow in each graft was measured with the other graft temporarily occluded. Flow reserve of the right coronary artery (mean internal diameter 1.5mm) proximal to the anastomosis was measured before and after opening of the coronary-coronary bypass. Mean(s.d.) flow as 50.0(12.3) ml/min in the coronary-coronary bypass graft and 54.9(14.8) ml/min in the aortocoronary bypass, which was not significantly different. Flow curve studies demonstrated early systolic flow reversal in the aortocoronary bypass, while the coronary-coronary bypass showed only forward flow. Mean(s.d.) flow in the proximal right coronary artery increased from 35.4(11.8) to 76.0(15.3) ml/min after opening the coronary-coronary bypass graft, which had a flow rate of 42.2(10.4) ml/min. It is concluded that the coronary-coronary bypass graft can provide nearly the same flow rate as aortocoronary bypass, and that the proximal right coronary artery has sufficient flow reserve for this technique.

Anastomosis, Surgical↗