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Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 577 records · Page 32Linked to original sources
PubMed1997

[Urgent coronary reoperation under the beating heart via the left thoracotomy].

An 80-year-old female, who had received coronary artery bypass grafting (CABG) 12 years ago was admitted to our hospital because of unstable angina. The vein grafts to the left anterior descending artery (LAD) and circumflex artery (Cx) were both occluded. Chest computerized tomography showed a severely calcified aorta. An intra-aortic balloon pump was inserted and an urgent reoperation was performed. The patient was positioned for an anterolateral left thoracotomy. The chest was entered through the forth intercostal space. The pericardium was opened parallel to the phrenic nerve. Femorofemoral bypass was instituted. Anastomosis of the saphenous vein graft and the diagonal branch and anastomosis of a second saphenous vein to the old SVG just proximal to the anastomotic site of Cx were performed under a beating heart. Proximal anastomosis of the two saphenous veins and the left subclavian artery was then performed. The patient had an uncomplicated postoperative recovery. A postoperative angiogram showed that the new SVG anastomosed to the diagonal branch was patent while the other new SVG anastomosed to the old SVG/Cx was occluded. The patient was discharged and is now free from angina.

Aged↗
PubMed1997

[Coronary bypass surgery in the elderly: characteristics and quality of life].

From November 1991 to December 1996, 66 patients aged 70 years or more underwent coronary artery bypass grafting (CABG). They were compared with a group of 200 consecutive patients aged less than 70 years of age who underwent CABG during the same period. The elderly patients had a higher incidence of female gender, smaller body structure, left main trunk disease, calcification of ascending aorta and emergency operation. However, there were no significant differences between two groups in hospital mortality, IABP insertion or length of stay in intensive care unit. Quality of life (QOL) of the elderly patients was evaluated for all the 58 survivors by means of Specific Activity Scale Questionnaires. Forty of the 58 patients (69%) had functional capacity of 5 METs or more. All the 43 patients who worked before CABG were able return to work, although some patients reduced their workload. We conclude that CABG in elderly patients can be performed with mortality and morbidity similar to those in younger patients. QOL is generally maintained.

Age Factors↗
PubMed1997

Standardization of low attenuation area versus total lung area in chest X-ray CT as an indicator of chronic pulmonary emphysema.

We examined the methods for measuring the LAA% (100 x low attenuation area/total lung area) on thoracic X-ray CT scans in order to develop a useful indicator of chronic pulmonary emphysema (CPE). First, we modified the method for calculating the LAA% to be applicable by the programming tool installed in a commercially available CT machine in order to minimize manual procedures. This new method proved to be applicable in all CT machines produced after 1987. Second, we examined the difference in the Hounsfield Unit (HU) between different CT machines using two kinds of phantoms. One phantom was composed of Styrofoam, which has a density similar to the low attenuation areas. The other phantom was composed of Styrofoam and water, which has a density similar to the lung. We proved that the difference of LAA% with the correct value was 5% at maximum among four different CT machines. Thus, the phantom developed in the present study may play an important role in the standardization of HU. Finally, the possibility of decreasing the X-ray levels was examined. Twenty-five percent of the standard electrical current provided the same LAA% in cases where the subject was an established CPE patient, whereas the LAA% was overestimated in subjects with a normal LAA% value. However, a correction using a linear regression equation may be possible in the latter cases. It may be concluded that LAA% analysis can easily be performed in many city hospital, without much investment of manual procedures or any corrections to the HU levels between different CT machines. This method may be useful as a routine follow up for CPE patients because of the smaller irradiated dose given when using a CT machine.

Algorithms↗
PubMed1997

[Evaluation of clinical utility of 111In-DTPA-IgG scintigraphy in the detection of inflammation/infection--a report of multicenter phase III clinical trials].

This is the report of phase III study to evaluate the safety and utility of 111In-DTPA-IgG in patients with strongly suspected inflammation/infection. One hundred and forty five patients with suspected sites of inflammation/infection were enrolled in the study. Only a few adverse experiences in one patient were reported, which were interpreted as having a possible relationship to the agent. A total of 171 suspected sites (12 in head and neck, 39 in thorax, 44 in abdomen and pelvis, 62 in musculoskeletal system, and 14 in other regions) were evaluated by investigators at each institute. Out of 171 sites, 18 were determined to be unevaluable, and 12 false negative and 5 false positive cases were observed. Overall sensitivity and specificity was 89.8% and 85.7%, respectively, and the agent proved to be effective in detecting lesions anywhere throughout the body. The analysis of data from this Phase III study indicates that 111In-DTPA-IgG is well-tolerated in patients and effective in determining focal sites of inflammation/infection although the physiological accumulation in some tissues such as the sinus or liver and possible excretion into the gastrointestinal tract may make it difficult to localize lesions.

Aged↗
PubMed1997

[A case of aortic valve replacement 3 years after coronary artery bypass grafting].

A rare case of aortic valve replacement (AVR) with poor left ventricular function, following coronary artery bypass grafting, was reported. The patient was 57-year-old man who received urgent CABG with 2 saphenous vein grafts 3 years ago. At that time, aortic regurgitation (AR) was grade 2. He suffered acute myocardial infarction 1 year after CABG because of the occlusion the saphenous vein graft to the obtuse marginal branch. Percutaneous transluminal angioplasty was successfully performed for occluded graft. Since then, however, AR increased gradually and the left ventricular function decreased. Three years after the initial operation, he was admitted again with congestive heart failure. Heart catheterization revealed grade 3 AR and 17% left ventricular ejection faction (LVEF). AVR was performed through a median sternotomy and 2 saphenous vein grafts were preserved. He showed uneventful postoperative recovery and is now very well with 40% LVEF.

Angina, Unstable↗
PubMed1997

[A case of thymic epidermoid carcinoma recurred in the pericardial cavity].

A 61-year-old woman with cough and sputum and right scapular pain was referred to our hospital with a suspected anterior mediastinal tumor by Chest X-rays and CT-scan. The tumor was diagnosed as thymic cancer cytologically by fine needle biopsy. At the the thoracotomy via median sternotomy, the tumor adhered to left brachial vein, superior vena cava and pericardium and it was dissected by maneuver. It was diagnosed as moderately differentiated epidermoid carcinoma by histology of the surgical specimen and involvement of the pericardium was histologically presumed. The patient received postoperative radiation therapy. A year after operation, the tumor recurred in the pericardial cavity. Inspite of resection of the recurred tumor and an anticancer chemotherapy, the patient died of cardiac failure due to the proliferated tumor around the heart. There are some reports that epidermoid carcinoma of the thymus may have different responses to radiation therapy according to histologic tumor differentiations. At resection of epidermoid carcinoma of thymus, therefore, intraoperative pathologic examination of the adhesive part of excised specimen and additional resection were essential to resect thymic cancer radically.

Carcinoma, Squamous Cell↗
PubMed1997

["Ghost Hanako's syndrome": report of 2 cases--initial stage of nonneurogenic neurogenic bladder (Hinman syndrome)?].

Two girls aged 6 and 7 years old with established urination habit complained of daytime incontinence and deterioration of nocturia after they started school life. They were quite afraid of the lavatory and sometimes skipped urination during school time completely. Voiding cystography revealed bladder trabeculation and vesicoureteral reflux. On cystometry, bladder compliance was preserved with no uninhibited contraction. Ghost tales about labatories, such as "the tale of Ghost Hanako," prevail in almost every elementary school in Japan. In some children, especially schoolgirls, lavatory phobia results in dysfunctional voiding. Such "Ghost Hanako's syndrome" may be an early phase of non-neurogenic neurogenic bladder (the Hinman syndrome). Detailed information regarding school life and urination habit is important for the treatment of this entity.

Child↗
PubMed1997

[Apolipoprotein E genotype as a risk factor in Japanese patients with early-onset and late-onset Alzheimer's disease].

Recent studies have provided evidence of an association of apolipoprotein E (apoE) epsilon 4 allele and late-onset sporadic Alzheimer's disease (AD). Some studies have shown the possibility that apoE epsilon 4 is a risk factor of developing AD in early-onset type. We have analyzed the apoE gene polymorphism in a sample of 310 Japanese AD subjects and 237 age-matched Japanese controls. We divided the sporadic AD patients into two subgroups of 237 late-onset (> 65 years) and 73 early-onset (< or = 65 years) patients, and into three subgroups according to their apoE genotype, no epsilon 4, one epsilon 4, and two epsilon 4 alleles. Our data confirmed an association between epsilon 4 allele and early-onset AD and late-onset AD. The odds ratios (95% confidence interval) referred to no epsilon 4 allele for AD were 3.4 (1.7-7.0) for one epsilon 4 allele and 20.3 (2.5-166.6) for two epsilon 4 alleles in early-onset type, and 6.7 (3.9-11.3) for one epsilon 4 allele and 19.0 (2.5-145.6) for two epsilon 4 alleles in late-onset type. These ratios were significantly increased in both early-onset AD and late-onset AD. Kaplan-Meier survival analysis, which estimates the age of onset for subjects with no, one, and two epsilon 4 alleles in early-onset and late-onset type, revealed a significant dose effect where each additional epsilon 4 allele made the age of onset earlier (p < 0.0001). The age of onset is 9.7 years earlier for two epsilon 4 bearers and 3.9 years earlier for one epsilon 4 bearers than no epsilon 4 bearers in late-onset AD, 2.9 years earlier for two epsilon 4 bearers and 1.4 years earlier for one epsilon 4 bearers than no epsilon 4 bearers in early-onset AD. Moreover, we studied an association between apoE epsilon 2 allele and early-onset AD and late-onset AD. There was a significantly decreased frequency of apoE epsilon 2 allele in patients with late-onset AD (p = 0.026), although the frequency of apoE epsilon 2 was not changed significantly in early-onset AD (p = 0.360). The odds ratios referred to no epsilon 2 allele for AD were 1.9 (0.6-5.7) for one epsilon 2 allele in early-onset type, and 0.4 (0.2-0.9) for one epsilon 2 allele in late-onset type. Our study suggested the difference in the effect of apoE genotype on developing AD between early-onset and late-onset type in Japanese patients.

Age of Onset↗
PubMed1997

Serum amyloid P component enhances induction of murine amyloidosis.

Serum amyloid P component (SAP), a common component of all known types of amyloid fibrils, protects amyloid fibrils from proteolysis in vitro. It is therefore speculated to contribute to the deposition of amyloid fibrils in various types of amyloidoses. However, a role for SAP in amyloid deposition is not yet known. To investigate the relationship between SAP and amyloid deposition, we used gene targeting techniques to generate a unique strain of mice carrying a null mutation at the sap locus. The resultant SAP-deficient mice displayed no obvious phenotypic abnormalities. We asked whether experimental amyloid A (AA) amyloidosis could be induced in the SAP-deficient mice. The wild-type and SAP-deficient mice did not differ in their synthesis of serum amyloid A, the precursor protein of AA amyloid fibril, in response to acute inflammation. The induction of AA amyloidosis, however, was significantly retarded in the SAP-deficient mice relative to wild-type mice. Our experiments present, for the first time, compelling evidence that, although not essential in the deposition of AA amyloid, SAP significantly accelerates this reaction. Thus, SAP enhances the induction of murine amyloidosis and may play an important role in the pathogenesis of human amyloidoses, including Alzheimer's disease.

Acute-Phase Reaction↗
PubMed1997

[A clinical study of intermittent hydronephrosis].

A clinical study was conducted on the intermittent hydronephrosis in children. Of 78 children with hydronephrosis due to ureteropelvic junction obstruction operated between 1991 and 1995, 5 had intermittent hydronephrosis. All 5 patients were boys between 6 months and 6 years of age. Presenting symptoms were intermittent flank pain and vomiting. Ultrasonography performed during pain attack demonstrated dilation of the renal pelvis in all patients. Diuretic renography demonstrated obstruction in 4 of the 5 children and deterioration of renal function on the affected side in 2. The cause of ureteropelvic junction obstruction was aberrant vessels in 2 cases, fibrous band in 1, ureteral kinking within adventitia in 1 and a ureteral polyp in 1. Postoperatively, all patients have been relieved from the pain. In summary, ultrasonography at the time of symptom attack as well as diuretic renography are useful for the diagnosis and observation of intermittent hydronephrosis.

Abdomen, Acute↗
PubMed1997

[Bladder hemangioma in a child: a case report].

We report a case of bladder hemangioma in a child. An 8-year-old girl was referred to our hospital for the evaluation of painless hematuria. Neither pyuria nor bacteriuria was detected. She had no dysuria. Intravenous pyelography showed deformity of the bladder without dilation of the upper urinary tract. Voiding cystourethrography revealed a filling defect of the bladder. Reddish blue masses were seen cystoscopically at the right wall and the dome of the bladder. Partial cystectomy was performed. From the histological findings, the diagnosis was cavernous hemangioma of the urinary bladder. Her postoperative course was uneventful and no recurrence was seen at the cystoscopical examination 3 months postoperatively. This is the 15th case of bladder hemangioma in children reported in Japan.

Child↗
PubMed1997

[A case of impending rupture of coronary aneurysm after rapid growth within a month].

A case of successful surgery for a rapidly growing aneurysm is described. The patient, a 47-year-old woman, had suffered from recurrent aphtous and genital ulcers for 17 years and hyperthyroidism for two years. One month after myocardial infarction, follow-up coronary angiography showed total obstruction at the distal part of the aneurysm in the left anterior descending artery with rapid dilation to 37 mm. Echocardiography revealed gradually increasing pericardial effusion. Urgent surgery was performed on January 11, 1995. Because Behçet's disease was suspected and since the vascular wall was suspected to have become fragile, surgery was performed using the aortic-no-touch technique. Under ventricular fibrillation, the proximal and distal part of the left anterior descending artery of the coronary aneurysm was ligated and bypass grafting was achieved at the distal part of the left anterior descending artery with the left internal thoracic artery. Low dose steroid treatment was started from nine days after surgery. The post operative course was satisfactory and coronary angiography during the first month showed no abnormal signs.

Aneurysm, Ruptured↗
PubMed1997

[A case report of thoracic outlet syndrome with acute arterial obstruction caused by abnormal first rib].

A 33-year-old male was transferred to our hospital because of coldness, numbness and pain in his right arm. Chest X-ray showed abnormal first ribs on both sides that were attached to the second ribs below the clavicles. Angiogram revealed an aneurysm of right subclavian artery, thrombus in the aneurysm and embolism to the brachial artery. Thrombectomy using a Fogarty catheter was done and the radial pulse recovered. Surgical resection of the abnormal first rib and thrombectomy was performed, because ischemic symptoms recurred in spite of anticoagulation and antiplatelet therapy. Acute arterial occlusion in patients with thoracic outlet syndrome is rare. The literature on arterial complications of thoracic outlet syndrome is reviewed.

Acute Disease↗
PubMed1996

Effect of sterical stabilization on macrophage uptake in vitro and on thickness of the fixed aqueous layer of liposomes made from alkylphosphocholines.

A serious problem using liposomes for therapeutic purposes is the fast removal from blood circulation by components of the reticuloendothelial system (RES) most likely after opsonization of the vesicles. This study was performed to quantify the reduction in macrophage uptake in vitro of sterically stabilized liposomes (PEG-liposomes) prepared from hexadecylphosphocholine, cholesterol and poly(ethylene glycol2000) distearoylphosphoethanolamine (PEG2000DSPE) for the first time. The uptake was determined using HPC-liposomes of different defined size (125, 250 and 1000 nm) without and with sterical stabilization by incorporating 5 mol% of PEG2000DSPE. HPTS was used as fluorescence marker allowing the discrimination between general uptake and the part of liposomes internalized into the low pH-compartment (Daleke, L.D., Hong, K. and Papahadjopoulos. D. (1990) Biochim. Biophys. Acta 1024, 352-366). Liposomal uptake by J774 mouse macrophage-like cells was time-dependent. Both the uptake and internalization were clearly reduced for PEG-liposomes compared to plain liposomes. Sterical stabilization reduced the general uptake of liposomes in vitro by more than 50% and the internalization by about 50-60%. PEG-liposomes additionally showed a delay in internalization into the macrophages during the first 6 h. Size of used liposomes had only a minor influence on liposomal uptake but highest concentration of lipid was found for large multilammelar vesicles (MLV). The fixed aqueous layer thickness (FALT) was determined by zeta potential measurements of plain and sterically stabilised HPC-liposomes (100 nm) in solutions of different ion concentrations. The calculation of the thickness was based on the linear correlation between ln zeta (zeta-potential) and kappa (Debye Hückel-Parameter). FALT was calculated and found to be for plain HPC-liposomes 0.83 +/- 0.17 nm and for PEG-HPC-liposomes 3.57 +/- 0.17 nm. Exchange of the HPC by an alkylphospholipid with different head group has no or only minor effect (PEG-OPP-liposomes 3.44 +/- 0.31 nm). Thus the reduced uptake of HPC-LUVET correlates with an increased thickness of the fixed aqueous layer around these liposomes and could support the hypothesis that the thickness is an important property responsible for preventing opsonization and resulting finally in a reduced macrophage uptake.

Animals↗
PubMed1996

Circadian variation in incidence of cardioembolism.

Cardioembolism is most likely to occur after waking in the morning. The identification of periods of high risk for cardioembolism may have important therapeutic implications, such as matching drug effects with vulnerability.

Adult↗
PubMed1996

Adrenomedullin augments inducible nitric oxide synthase expression in cytokine-stimulated cardiac myocytes.

BACKGROUND: Plasma levels of adrenomedullin are increased in patients with congestive heart failure, but there has been no report concerning the effects of adrenomedullin on the heart. We investigated the effects of adrenomedullin on NO synthase activity in cardiac myocytes. METHODS AND RESULTS: We measured the production of nitrite, a stable metabolite of NO, in cultured neonatal rat cardiac myocytes with the Griess reagent. Inducible NO synthase mRNA and protein expression were assayed by Northern and Western blotting, respectively. Incubation of the cultures with interleukin-1 beta (10 ng/mL) for 24 hours caused a significant increase in nitrite accumulation. Adrenomedullin significantly augmented nitrite production by interleukin-1 beta-stimulated but not by unstimulated cardiac myocytes in a dose-dependent manner (10(-10) to 10(-6) mol/L). The adrenomedullin-induced nitrite production by interleukin-1 beta-stimulated cells was accompanied by increased inducible NO synthase mRNA and protein expression. In the presence of dibutyryl cAMP, the interleukin-1 beta-induced nitrite accumulation was increased further, but the stimulatory effect of adrenomedullin on nitrite production was abolished. Adrenomedullin dose-dependently increased intracellular cAMP levels in cardiac myocytes. Addition of the calcitonin gene-related peptide (CGRP) receptor antagonist CGRP[8-37] to the culture dose-dependently inhibited both cAMP and NO generation stimulated by adrenomedullin. CONCLUSIONS: These results indicate that adrenomedullin acts on cardiac myocytes and augments NO synthesis in these cells under cytokine-stimulated conditions, at least partially through a cAMP-dependent pathway.

Adrenomedullin↗
PubMed1996

Effect of cilostazol, a cAMP phosphodiesterase inhibitor, on nitric oxide production by vascular smooth muscle cells.

We investigated the effects of cilostazol, a cAMP phosphodiesterase inhibitor, on nitric oxide (NO) synthesis in cultured rat vascular smooth muscle cells. Incubation of the cultures with interleukin-1 beta (10 ng/ml) for 24 h caused a significant increase in the accumulation of nitrite, a stable metabolite of NO. Although cilostazol itself showed no effect on nitrite accumulation, it stimulated interleukin-1 beta-induced nitrite accumulation in a concentration-dependent manner (10(-8)-10(-5) M). This effect of cilostazol was completely abolished in the presence of NG-monomethyl-L-arginine, actinomycin D or dexamethasone. The cilostazol-induced nitrite production was accompanied by increased inducible NO synthase protein expression. In the presence of dibutyryl-cAMP, interleukin-1 beta-induced nitrite accumulation was further increased, but the stimulatory effect of cilostazol on nitrite accumulation was blunted. The effect of cilostazol was also abolished in the presence of Rp-8-bromoadenosine-3',5-cyclic monophosphorothioate, a competitive inhibitor of protein kinase A. Addition of cilostazol to the cultures significantly increased intracellular cAMP levels of vascular smooth muscle cells. These results indicate that cilostazol increases NO synthesis in interleukin-1 beta-stimulated smooth muscle cells, at least partially through a cAMP-dependent pathway.

Animals↗