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Biomedical subjects

M Endo

Publications and source records attributed to M Endo.

At least 253 records · Page 14Linked to original sources
PubMed1998

Afterload-dependent flow fluctuation of centrifugal pump: should it be actively fixed?

To evaluate the clinical meaning and effects of afterload-dependent flow fluctuation in a centrifugal pump, concomitant measurement of flow rate and mixed venous oxygen saturation (SVO2) was performed in 5 cases of open heart surgery in which the patients underwent cardiopulmonary bypass (CPB) with the Terumo Capiox centrifugal pump. Continuous measurement of SVO2 using the 3M CDI System 100 was performed with a disposable cuvette incorporated into the drainage circuit. After the target flow rate of 2.4 L/min/m2 was obtained under a nonbeating condition, the pump rotational speed was fixed. During the cooling and low temperature period, SVO2 decreased as the flow rate spontaneously decreased but still stayed around 80% even with a 15-20% decrease in blood flow rate. This indicates that a luxury perfusion condition is ensured as long as the body temperature is kept low. In contrast, during the rewarming period, SVO2 decreased to around 70-75% despite a 15-25% spontaneous increase in flow rate. Although this level of SVO2 still indicates adequate systemic perfusion, there is a possibility of regional hypoperfusion in patients with such conditions as cerebrovascular disease. In conclusion, although diligent adjustment of the physiological fluctuating flow rate in the centrifugal pump seems unnecessary during conventional open heart surgery, manual control may be necessary especially during the rewarming period, normothermic surgery, or circulatory assist for shocked patients. From this study, we also conclude that the major benefit of the afterload-independent autoflow control system of the centrifugal pump is the improvement of safety in terms of the fixed reservoir level and the handling of cardiopulmonary bypass.

Blood Flow Velocity↗
PubMed1998

Minimally invasive cardiac surgery in the adult: surgical instruments, equipment, and techniques.

To clarify the special instruments and equipment used for minimally invasive cardiac surgery (MICS), we examined the initial experiences with MICS operations with ministernotomy or minithoracotomy at our institution. Fifty adult patients with congenital, valvular, and/or ischemic heart diseases underwent MICS operations, and all surgical procedures were completed without conversion to full sternotomy. The length of the skin incision was about 10 cm or less in all patients. Postoperative recovery was favorable, and the majority of the patients were discharged from the hospital around the end of the second postoperative week. In this series of patients, an oscillating bone saw, lifting type retractor, 2 blade spreader, cannula with a balloon, and right-angled aortic clamp among other items, were very useful for successfully performing various operations with MICS approaches and techniques. The associated results suggest that MICS with ministernotomy or minithoracotomy was feasible using special instruments and equipment and could be encouraged for adult patients with various cardiovascular diseases.

Adult↗
PubMed1998

Pathophysiological response of cytokines and vasoactive agents in patients undergoing total gastrectomy.

OBJECTIVE: To investigate the involvement of vasoactive agents, endothelin (ET)-1, and atrial natriuretic peptide (ANP), and the responses of cytokines in patients undergoing total gastrectomy. DESIGN: Prospective study. SETTING: University hospital, Japan. SUBJECTS: 20 patients with advanced gastric cancer who had undergone total gastrectomy with lymph node dissection. INTERVENTIONS: Serum or plasma samples collected on the day before the operation, at the time of skin closure, and on postoperative days 1, 3, 5, and 7. MAIN OUTCOME MEASURES: Concentrations of acute phase reactants, cytokines (interleukin (IL)-1, tumour necrosis factor (TNF) and interleukin (IL)-6), and vasoactive agents (ET-1 and ANP). RESULTS: There were significant increases in concentrations of IL-6 and acute phase reactants postoperatively. ET-1 and ANP concentrations did not change significantly. CONCLUSION: There was no correlation between concentrations of the vasoactive agents ET-1 and ANP, and those of acute phase reactants or cytokines in serum or plasma in patients undergoing total gastrectomy.

Acute-Phase Proteins↗
PubMed1998

Relationship between CT number and electron density, scatter angle and nuclear reaction for hadron-therapy treatment planning.

The precise conversion of CT numbers to their electron densities is essential in treatment planning for hadron therapy. Although some conversion methods have already been proposed, it is hard to check the conversion accuracy during practical therapy. We have estimated the CT numbers of real tissues by a calculational method established by Mustafa and Jackson. The relationship between the CT numbers and the electron densities was investigated for various body tissues as well as some tissue-equivalent materials used for a conversion to check the accuracy of the current conversion methods. The result indicates a slight disagreement at the high-CT-number region. A precise estimation of the multiple scattering, nuclear reaction and range straggling of incident particles has been considered as being important to realize higher-level conformal therapy in the future. The relationship between these parameters and the CT numbers was also investigated for tissues and water. The result shows that it is sufficiently practical to replace these parameters for real tissues with those for water by adjusting the density.

Biophysical Phenomena↗
PubMed1998

Ion-spray mass spectrometry for identification of the nonreducing terminal sugar of glycosaminoglycan.

Various oligosaccharides from hyaluronic acid, which have glucuronic acid or N- acetylglucosamine at the nonreducing terminal, were prepared by digestion with a combination of testicular hyaluronidase and beta-glucuronidase. These oligo saccharides were analyzed by negative-mode ion-spray mass spectrometry (MS) with an atmospheric pressure ion source. Introduction of collisionally activated dissociation tandem mass spectrometry (CAD-MS/MS) produced ions derived from cleavage of the glycosidic bonds, allowing the structure to be analyzed. The CAD-MS/MS spectrum showed an intense and characteristic fragment ion at m/z 193 for oligosaccharides having glucuronic acid at the nonreducing terminal. On the other hand, this ion was not observed in the spectra of oligosaccharides having N- acetylglucosamine at the nonreducing terminal. Therefore, the fragmentation pattern revealed by CAD-MS/MS provides useful information for distinguishing glucuronic acid and N- acetylglucosamine at the nonreducing terminal of oligosaccharides derived from hyaluronic acid and other glycosaminoglycans. This ion-spray CAD-MS/MS technique was also applied successfully to the characterization of glycosaminoglycans reconstructed by glycotechnology.

Animals↗
PubMed1998

A novel 4-methylumbelliferyl-beta-D-xyloside derivative, sulfate-O-3-xylosylbeta1-(4-methylumbelliferone), isolated from culture medium of human skin fibroblasts, and its role in methylumbelliferone-initiated glycosaminoglycan biosynthesis.

Human skin fibroblasts were incubated in the presence of 4-methylumbelliferyl-beta-D-xyloside (Xyl-MU). The culture medium was recovered and Xyl-MU derivatives which were initiated by the Xyl-MU acting as a primer were purified. As a result, a novel Xyl-MU derivative was isolated, in addition to previously reported Xyl-MU derivatives such as glycosaminoglycan-MU, Gal-Gal-Xyl-MU, Gal-Xyl-MU, SA-Gal-Xyl-MU, Xyl-Xyl-MU, GlcA-Xyl-MU, and sulfate-GlcA-Xyl-MU. This Xyl-MU derivative was subjected to carbohydrate composition analysis, enzyme digestion, ion-spray mass spectrometric analysis, and Smith degradation. The results indicated that it was sulfate- O -3-Xyl-MU. When Xyl-MU was incubated with [35S]PAPS using a homogenate prepared from the same cultured skin fibroblasts, [35S]sulfate- O -3-Xyl-MU was produced. Moreover, when Xyl-MU was incubated with UDP-[3H]Gal, [3H]galactose was transferred to Xyl-MU, but when sulfate- O -3-Xyl-MU was incubated with UDP-[3H]Gal, [3H]galactose was not transferred. These results indicate that chain elongation from Xyl-MU is inhibited by sulfation of Xyl-MU, and that Xyl-MU sulfation is involved in the control of Xyl-MU-initiated glycosaminoglycan biosynthesis.

Cells, Cultured↗
PubMed1998

Glomerular deposition of mannose-binding lectin (MBL) indicates a novel mechanism of complement activation in IgA nephropathy.

BACKGROUND: IgA nephropathy (IgA-N) is considered the most common glomerular disease in the world and leads to renal failure in a substantial number of patients. Although many studies have looked at the pathogenesis of the disease, many points need to be clarified, including the mechanism of complement activation. Recent studies have shown that mannose-binding lectin (MBL or mannose binding protein, MBP) initiates activation of the complement cascade (lectin pathway) utilizing two types of MBP-associated serine protease, namely MASP-1 and MASP-2. The present study was undertaken to elucidate whether the lectin pathway was involved in the pathogenic mechanism of IgA-N. METHODS: Forty-five renal biopsy cases with IgA-N, 35 cases with other forms of glomerulonephritis (GN), and normal kidney tissues were collected and an immunohistochemical study was performed using monoclonal antibodies against MBL and MASP-1. Furthermore, clinicopathological and serological features were also analysed in the patients with IgA-N. RESULTS: Glomerular deposition of MBL, which was accompanied by MASP-1, was detected in 11 of 45 (24.4%) cases with IgA-N, while it was detected in only one case with other forms of GN. The deposited MBL/MASP-1 was observed to associate with C3b/C3c and C5b-9 but not with IgG, IgM, C1q, C4c, or properdin. Compared with MBL/MASP-1 negative cases with IgA-N, the positive cases with IgA-N were young and the renal biopsies had been performed at an early stage of the disease. No significant correlation was found between glomerular deposition of MBL/MASP-1 and proteinuria, haematuria, creatinine clearance, and serum levels of IgA, C3, or C4 at the time of renal biopsy. There were also no significant differences between MBL/MASP-1 positive cases and negative cases in the plasma levels of circulating immune complexes or soluble C5b-9. CONCLUSION: The lectin pathway of complement activation, which is initiated by the MBL/MASPs complex, evidently contributes to the development of glomerular injury in a significant number of cases with IgA-N. In addition, these findings will add insight to the pathogenesis of IgA-N, including its relation to infection, since MBL plays a crucial role in the host defense against various pathogens.

Adolescent↗
PubMed1998

Role of ABC transporters in aureobasidin A resistance.

Aureobasidin A (AbA) has strong antifungal effects arising from an unusual mechanism. We show that AbA interacts with ATP-binding cassette (ABC) transporters in yeast and mammalian cells. We isolated a gene of Saccharomyces cerevisiae that conferred resistance to AbA when the gene was present in multiple copies. The gene was identical to YOR1/YRS1, which confers resistance to oligomycin, reveromycin, and organic anions, none of which have structures similar to that of AbA. We also isolated an aur3R recessive mutant of S. cerevisiae with increased resistance to AbA. Northern hybridization showed that the aur3R mutant expressed not only YOR1 but also the ABC transporter-encoding gene PDR5 at high levels. Genetic studies showed that the aur3R mutant had a mutation in the PDR1 gene, which encodes a transcriptional regulator of PDR5 and YOR1. Analysis of a yor1 disruptant of the aur3/pdr1 mutant showed that both the functional YOR1 gene and the mutation in PDR1 were necessary for AbA resistance. These results suggest that YOR1 is more important than PDR5 for AbA resistance. We found in Candida albicans a novel gene whose sequence was similar to the sequence of YOR1 in S. cerevisiae. The amino acid sequence of the C. albicans YOR1 homolog showed no significant similarity to the sequences of CDR1 and CDR2, which are ABC transporters of C. albicans. Furthermore, AbA inhibited the efflux of the anticancer agent vincristine through P glycoproteins in cancer cells with multidrug resistance.

ATP-Binding Cassette Transporters↗
PubMed1998

Appearance of nephrotic syndrome following interferon-alpha therapy in a patient with hepatitis B virus and hepatitis C virus coinfection.

A 59-year-old woman with hepatitis B surface antigen (HBsAg) and hepatitis C viral (HCV) antibody presented with proteinuria and hematuria. The patient was treated with interferon-alpha (INF-alpha) because plasma aminotransferase levels had been elevated and a liver biopsy had showed chronic active hepatitis. Her urinary protein excretion decreased as liver function normalized and her serum HCV-RNA was negative during treatment. Eleven weeks after completion of INF-alpha treatment, she suddenly presented with nephrotic-range proteinuria, although an improvement in the hepatic function was maintained. Renal pathologic findings were consistent with membranous glomerulonephritis (MGN), and HBsAg was detected in the glomeruli but not HCV. After treatment with prednisolone, her 24-hour protein excretion was below 0.7 g/day. To our knowledge this is the first report on hepatitis B virus MGN with nephrotic syndrome following IFN-alpha therapy for HCV. This suggests that treatment with INF-alpha might affect the immune processes and may be associated with the pathogenic mechanism in this patient.

Anti-Inflammatory Agents↗
PubMed1998

Extraperitoneal retrograde transhepatic biliary drainage for common bile duct exploration for prevention of tube dislodgment and its earlier removal.

Primary bile duct closure with retrograde transhepatic biliary drainage (RTBD) using an RTBD tube (RTBDT) is a feasible surgical technique after common bile duct exploration in choledocholithiasis in comparison to conventional T-tube insertion. But, unfortunately, this technique is not popular because of the difficulty to introduce a catheter into a proposed intrahepatic bile duct branch without hepatic injury. In addition, the time for its safe removal is not shorter than that with T-tube insertion. So, we have devised a special needle-attached RTBDT (n-RTBDT) to guide the tube via the intrahepatic bile duct of the liver with minimal hepatic injury, and proposed a new surgical technique, namely extraperitoneal RTBD (Ep-RTBD), using the n-RTBDT providing earlier removal without fistula formation in the general peritoneal cavity. In all patients with common bile duct calculi who underwent this surgical procedure, the tube could be revoved within 10 postoperative days with no complication.

Biliary Tract Surgical Procedures↗
PubMed1998

Virtualized angioscopy of the thoracic aorta in a rabbit model of atherosclerosis.

The purpose of this study was to apply virtual reality technology to spiral computed tomographic (CT) angiogram images in a rabbit model of atherosclerosis and to correlate the images with histopathologic evaluation of the aorta. Image data were transferred to the virtual endoscope system in a graphics workstation. "Virtualized angioscopy" includes an interactive graphic user interface, which controls the viewpoint, the direction of the observation, and rendering and navigation functions. The virtual angioscopy system demonstrated irregularities of the luminal surface of the ascending aorta and a smooth luminal surface in the descending aorta. These observations were correlated with histopathologic findings. The results of this study indicate that the potential and real benefits of virtualized angioscopy far outweigh several technical limitations.

Angioscopy↗
PubMed1998

Salivary amylase activity of rats fed a low calcium diet.

Wistar strain rats fed low calcium diets (1, 2, 3, 4, 6 and 8 weeks) exhibited changes in secretory function of whole saliva. In particular, there were changes in salivary flow rate, total salivary protein, amylase enzyme activity, salivary amylase content and the level of cyclic AMP in the parotid gland acinar cell. Although there were no changes for the first 3 weeks, the levels increased at week 4 and decreased at week 6. The wet weight of the parotid gland started to decrease at week 4. These results suggest that when fed low calcium diets for long periods of time, rats develop defective salivary secretion.

Amylases↗
PubMed1998

A novel epitope (pentapeptide) in the human hemoglobin beta chain.

We have cloned 16 monoclonal antibodies by immunizing mice with human hemoglobin for the purpose of analyzing epitopes in human hemoglobin. By using one, SU-115, which is specific for the beta chain, an epitope in the beta chain reacting with this monoclonal antibody was investigated, and a pentapeptide was identified as a novel epitope. After digestion of the beta chain by lysylendopeptidase, the antigenicity of degradation products was examined. An antigenic fragment against SU-115 was found to be a peptide corresponding to residues 96-120 of the beta chain by amino acid analysis of its N-terminal region. Several peptides involved in the region of beta96-120 were synthesized to be examined for their reactivity to SU-115 using dot-blot analysis and a resonant mirror detection method, and a pentapeptide (N108VLVC) was determined as a major sequence of an epitope. By injecting this pentapeptide into a mouse, an antibody reacting human hemoglobin (alpha2beta2) in the same order of strength as SU-115, was obtained. The pentapeptide described in this paper seems to be the minimum size as a major sequence of the actual epitope in human hemoglobin so far reported, and in the primary structure of this region (108-112) there is a difference of three amino acids between human and mouse hemoglobin.

Amino Acid Sequence↗
PubMed1998

[The effect of MS-551 on two VT/Vf patients in CABG: a case report].

Uncontrollable arrhythmia is one of the causes of operative death in CABG. We report two cases of successful treatment of recurrent VT/Vf in CABG operation by MS-551. One case was a 72-year-old male, who had unstable angina and OMI with left ventricular dysfunction (LVEF 24%). After weaning from CPB, the rhythm turned into VT/Vf suddenly. Lidocaine and verapamil were not effective. VT/Vf recurred over the over. The another case was a 52-year-old male, who had OMI and effort angina. He became myocardial infarction during operation. VT/Vf occurred after the weaning from CPB. Lidocaine and amiodarone were of no effect on his VT/Vf. In both cases, intravenous injection of MS-551 promptly stopped VT/Vf. Use of MS-551 was limited mainly on DCM patients. But other antiarrhythmic agents were ineffective on these cases. We have had to continue support circulation for a long time without MS-551. As MS-551 is being used as a trial on medically followed patients, it was unknown how effective clinically on the acute myocardial infarction. In this regard, our cases may suggest a positive answer to that.

Aged↗
PubMed1998

[Brain damage following aortic arch repair with regard to techniques of selective cerebral perfusion and preoperative cerebral lesions].

One hundred and twenty-nine aortic aneurysm patients (true 68 and dissection 61) underwent aortic arch repair from January 1987 to December 1995. Postoperative brain damage was evaluated regarding both preoperative brain lesions and techniques of selective cerebral perfusion (SCP) in that one pump for SCP until April 1992, then two pumps were employed, one for right and the other for left hemisphere of the brain. Overall hospital mortalities were 21% in true and 13% in dissecting aneurysms. Ten patients were complicated with postoperative brain damages (coma 8 and hemiplegia 2), registering 7.8% of total patients. Both history of stroke and silent cerebral infarction (SCI) detected by CT and/or MRI were considered to be positive in the mean of having preoperative brain lesions. Although there was no significant difference between incidences of postoperative brain damage in true and dissecting aneurysms, registering 11% and 4% respectively, preoperative brain lesions in true aneurysm (68%) was significantly greater than dissecting aneurysm (32%). Furthermore, the incidence of postoperative brain damage was 22% in one-pump SCP which was significantly greater than 3% in two-pumps SCP in the patients with a true aneurysm. But there was no postoperative brain complication in patients with SCI even using either one two pumps for SCP. The present data suggest two-pumps SCP is better technique for cerebral protection compared to one-pump SCP for aortic arch repair.

Adult↗
PubMed1998

Serum C3 content in vitamin B(12)-deficient rats.

As a clue to clarifying the role of vitamin B12 (B12) in the function of the complement system, serum C3 content was determined in B12-deficient rats, and the effect of the administration of methylcobalamin (CH3-B12) on the serum C3 content was also studied. It was found that the serum C3 content in rats fed on a vitamin B12-deficient diet for 90 and 120 days significantly decreased compared with that in control rats. The administration of CH3-B12) restored the serum C3 content to control levels. The above results indicate that B12-deficiency depressed the serum C3 content and lowered humoral immunocompetence, and that these changes were ascribable to B12-deficiency.

Animals↗
PubMed1998

[Polyclonal plasmacytosis in peripheral blood and leukocytoclastic vasculitis in Castleman's disease].

A 62 year-old man had fever, splenomegaly, systemic lymphadenopathy and palpable petechiae. Laboratory studies showed leukocytosis (10,200/microliters) with plasma cells (23%) and polyclonal gammopathy. Southern blot analysis of peripheral blood mononuclear cells showed no rearrangement of immunoglobulin genes, indicating polyclonal plasmacytosis in peripheral blood. A diagnosis of Castleman's disease was made by the cervical lymph node biopsy, which showed onion-skin structures in the germinal centers and plasmacytosis in the interfollicular region. A skin biopsy of the purpura lesion disclosed leukocytoclastic vasculitis. This is an unusual case of Castleman's disease presenting plasmacytosis in peripheral blood and leukocytoclastic vasculitis.

Castleman Disease↗