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K Shimada

Publications and source records attributed to K Shimada.

At least 469 records · Page 26Linked to original sources
PubMed1998

[A case report of extralobar pulmonary sequestration associated with mediastinal bronchogenic cyst].

A 48-year-old woman was admitted to our hospital because of abnormal shadow on the chest X-ray. Chest contrast CT scan showed roundly mass in the posterior mediastinum which were combined with and without contrast elements, and chest MRI (T2 weighted) showed high signal intensity. These features suggested mediastinal cyst or extralobar sequestration. The operation was performed through left 6th intercostal thoracotomy. Two different lesions connected to the mediastinum were confirmed, a cystic tumor and small accessory lung. The former was diagnosed as bronchogenic cyst and the latter as extralobar pulmonary sequestration.

Bronchogenic Cyst↗
PubMed1998

Optimal conditions of immune complex transfer enzyme immunoassays for antibody IgGs to HIV-1 using recombinant p17, p24, and reverse transcriptase as antigens.

The immune complex transfer enzyme immunoassays for antibody IgGs to p17, p24, and reverse transcriptase (RT) of HIV-1 were tested under various conditions. Antibody IgGs to HIV-1 were reacted for up to 20 hr with 2,4-dinitrophenyl-bovine serum albumin-recombinant HIV-1 protein conjugates and recombinant HIV-1 protein-beta-D-galactosidase conjugates, and the immune complexes formed, comprising the three components, were trapped onto polystyrene beads coated with (anti-2,4-dinitrophenyl group) IgG by incubation at 4-30 degrees C for up to 2 hr with shaking and were transferred onto polystyrene beads coated with (antihuman IgG gamma-chain) IgG in the presence of excess of epsilon N-2,4-dinitrophenyl-L-lysine by incubation at 4-30 degrees C for up to 2 hr with shaking. When serum randomly collected from an HIV-1 seropositive subject and serum included in an Western blot kit were tested, the formation of the immune complex was almost completed within 1 hr for antibody IgG to p17, within 1-2 hr for antibody IgG to p24 and within 4 hr for antibody IgG to RT. Even for antibody IgG to p17, however, the immune complex continued to be formed for at least 2 hr, when serum samples at early stages of HIV-1 infection were tested. Trapping and transferring of the immune complexes were faster at higher temperatures and were almost completed within 0.5-1.5 hr, although the amount of the immune complexes trapped and transferred at 25 and/or 30 degrees C increased for 0.5-1 hr, but subsequently tended to decline. When the formation, trapping, and transferring of the immune complexes were performed for 0.5, 1, and 1 hr, respectively, with shaking followed by 1 hr assay of bound beta-D-galactosidase activity, the sensitivities for antibody IgGs to p17, p24, and RT using 10 microliters of serum samples were similar to or significantly higher than those of the corresponding previous immune complex transfer enzyme immunoassays using 10 microliters of serum samples, in which the formation, trapping, and transferring of the immune complexes were performed for 3, 16, and 3 hr, respectively, without shaking, followed by 2.5 hr assay of bound beta-D-galactosidase activity, and the sensitivities for antibody IgGs to p17, p24, and RT using 100 microliters of serum samples were 21-22-fold, 5.5-6.3-fold, and 5.3-6.0-fold, respectively, higher. When each period of time for the formation, trapping, and transferring of the immune complexes was prolonged to up to 4 hr, the sensitivities for antibody IgGs to p17, p24, and RT using 100 microliters of serum samples were improved 88-93-fold, 15-17 fold and 20-24-fold, respectively, as compared with those of the previous ones.

Antigen-Antibody Complex↗
PubMed1998

[A case of MIDCAB to the left circumflex via the left posterolateral thoracotomy].

There have been many reports of MIDCAB to left anterior descending artery via a small dissection utilizing the left anterolateral thoracotomy. We report here a case of CABG reoperation to the circumflex artery by MIDCAB via the left posterolateral thoracotomy. A 66-year-old male patient had received a 3 branch bypass graft on the LITA-LAD and the SVG-OM-4 PD at another institution. Postoperative angiography revealed a SVG occlusion. Since repeated intervention was unsuccessful, reoperation was necessary. To preserve the patency of the LITA, the 4th left intercostal posterolateral thoracotomy was selected. We utilized a commercially available rib retractor for MIDCAB, as well as a stabilizer and a CO2 blower to obtain a nearly perfect bloodless stabilized view. A new SVG was used to connect the left circumflex artery. The operation was successful without any postoperative complications or need for transfusion. After a two week hospital stay, the graft patency was confirmed and the patient was discharged.

Aged↗
PubMed1998

[Case report of the right-sided aortic arch (N-type): new classification based on macroscopic observations].

We report on a case with unusual origin of the left subclavian artery, so-called N-type found in a 62-year-old Japanese male in 1995. We took the opportunity in proposing for a new classification based on macroscopic observations. In the present observation, the following arteries branched off from the aortic arch in the order of the left common carotid, the right common carotid, the right subclavian and the left subclavian arteries. There was an aortic diverticum between the left subclavian artery and the dissending aorta. The left subclavian artery passed between the esophagus and the thoracic vertebrae. The arterial ligament connected the left pulmonary artery with the aortic diverticulum of the left subclavian artery. According to our observations, the arch of the aorta, descending aorta, aortic diverticulum of the left subclavian artery, arterial ligament and pulmonary artery joined to foam an incomplete vascular ring around the trachea and esophagus. This case can be classified into the N-type according to classifications by Adachi (1928), Williams (1932, 1935) and Nakagawa (1939). This may be the 22nd report in Japan regarding this kind of combined variations. Our classification also includes those by Takemura (1990) and Edwards (1964). An explanation of the new classification is described below and is also shown in Fig. 3. Abbreviations for classification types have been arranged in the order of the relation to the esophagus, the mirror-image subtyping of the Takemura's classification and the location of the arterial ligament. For example, type Na1 (present case) represents the left subclavian artery passing behind the esophagus, mirror-image to the Takemura's G-type, and left arterial ligament.

Aorta, Thoracic↗
PubMed1998

[Long-term results after hepatectomy for hepatocellular carcinoma according to cancer stage].

The survival rates after hepatectomy for hepatocellular carcinoma (HCC) according to cancer stage were reported. The 5-year survival rates of Stage 1, 2, 3 and 4 were 69.6%, 54.2%, 35.9% and 30.2%, respectively. A significant difference was observed between any neighboring two stages. But more than 5 years till 20 years, the survival curves cross at some times. That means after 5 years the influence of the anatomic condition of the initial cancer has been weak. Probably another factor which controls multi-centric carcinogenesis of HCC may work. When the survival rate was calculated dividing the stage group into two sub-groups according to liver function, with good function or poor function, the survival of the poor liver function group of any stage group was worse than that of the good liver function group of the nearest worse stage group. The survival after hepatectomy of HCC depends not only upon anatomic condition of the cancer but also upon the liver function.

Carcinoma, Hepatocellular↗
PubMed1998

[Systematic resection for hepatocellular carcinoma].

We have performed systematic subsegmentectomy in patients with hepatocellular carcinoma complicated mainly by cirrhosis. Such small anatomical resections have become possible due to the introduction of intraoperative ultrasonography and of vascular occlusion techniques. As a result of our clinical experience involving 163 cases, it has been clarified that subsegmentectomy is a safe procedure (operative mortality rate, 0.6%) and results in a favorable long-term outcome (5-year survival rate, 51%). In the resected specimens, microscopic cancer spread was recognized frequently (portal venous invasion, 41%; intrahepatic metastasis, 31%). Subsegmentectomy is therefore the first procedure of choice in patients who have small hepatocellular carcinoma and chronic hepatitis or cirrhosis.

Aged↗
PubMed1998

Simple and Patlak models for myocardial blood flow measurements with nitrogen-13-ammonia and PET in humans.

UNLABELLED: The Simple and Patlak models for estimating myocardial blood flow with 13N-ammonia have become attractive for clinical applications with PET because of their simplicity and ease of implementation. However, these models are sensitive to factors such as the data acquisition times and data integration times, which can cause errors in the estimation of myocardial blood flow, as demonstrated in this study. Limiting the application of these models to specific conditions can minimize the errors. METHODS: Dynamic PET images of the uptake of 13N-ammonia in the heart were obtained in seven humans under rest and dipyridamole stress. Myocardial blood flow was estimated using the Simple and Patlak models for different data acquisition times and data integration times. Blood flow values were compared to flow values computed with the two-compartment model as a reference. RESULTS: Blood flow values calculated with the Simple and Patlak models during the first 2 min of data acquisition were closely correlated to the two-compartment model values. Longer acquisition times resulted in significant underestimation of blood flow for the Simple model. Long integration times of greater than 60 sec also resulted in significant underestimation of blood flow for both models. CONCLUSION: The Simple and Patlak models produce estimates of myocardial blood flow that are well correlated with the two-compartment model estimated blood flows for the integration time of 60 sec from 60 to 120 sec postinjection. Because of the errors associated with longer data acquisition times and longer integration times, use of these models should be limited to a well-documented data acquisition paradigm.

Ammonia↗
PubMed1998

Endothelial cell damage and angiotensin-converting enzyme insertion/deletion genotype in elderly hypertensive patients.

OBJECTIVES: The purpose of this study was to investigate the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) genotype and endothelial cell dysfunction or hypercoagulable state in elderly hypertensive patients. BACKGROUND: Angiotensin-converting enzyme (ACE) insertion/ deletion (I/D) polymorphism was recently reported to be associated with various cardiovascular diseases. However, the precise mechanism of this association remains unknown, and some confounding factors might also affect the association. Endothelial cell dysfunction and coagulation activation play important roles in both the atherosclerotic process and the onset of cardiovascular events. METHODS: We identified the ACE I/D genotype and measured the plasma levels of markers of endothelial cell damage (von Willebrand factor [vWF] and thrombomodulin) and of coagulation activation (prothrombin fragment F1 + 2 [F1 + 2]) in 318 asymptomatic elderly patients with hypertension, aged 59-93 years. RESULTS: The vWF level was significantly higher in those with the DD genotype (n = 54) than in those with the II genotype (n = 131, p < 0.0001) or with the ID genotype (n = 133, p < 0.0001). The TM levels were also higher in patients with the ID genotype (p < 0.005) and the DD genotype (p < 0.01) than in those with the II genotype. There were no differences in F1 + 2 level among the groups. Positive correlations of systolic blood pressure with levels of both vWF and thrombomodulin were found predominantly in patients with the II genotype (both p < 0.001), but no correlation was noted in those with the DD genotype. CONCLUSIONS: Considering the increased plasma levels of both endothelial cell-derived markers in the hypertensive patients with ACE DD genotype, we speculate that the ACE D allele is a risk factor for the development of hypertensive cardiovascular disease associated with endothelial cell damage.

Aged↗
PubMed1998

[Role of cytokines in acute coronary syndrome].

Cytokines modulate immunologic processes, inflammation, proliferative responses and apoptosis. Recent studies focused on the role of proinflammatory cytokines in cardiovascular diseases. Proinflammatory cytokines, such as interleukin (IL)-6, IL-8, IL-1 beta and tumor necrosis factor-alpha play important roles in acute coronary syndrome by regulating inflammation, cellular adhesion and production of growth factors and various vasoactive substances. Reperfusion after myocardial infarction and transient myocardial ischemia are supposed to induce these proinflammatory cytokines. We reviewed the mechanisms and clinical significance of proinflammatory cytokine expression in acute coronary syndrome. In addition we recently found out that an interaction between monocytes and vascular endothelial cells induces matrix metallo-proteinase expression by these cytokine-mediated mechanisms.

Acute Disease↗
PubMed1998

High-resolution cardiac PET in rabbits: imaging and quantitation of myocardial blood flow.

UNLABELLED: A high-resolution PET system for small animals was tested for its applicability to the investigation of regional myocardial blood flow (MBF) in rabbits. METHODS: Nineteen measurements were performed in 10 closed-chest anesthetized rabbits at baseline and during infusions of adenosine (0.2 mg/kg/min) and propranolol (0.20-1.20 mg slow infusion) to obtain a wide range of MBF. Myocardial blood flow was assessed both by dynamic 13N-ammonia PET and by colored microspheres. Blood was withdrawn directly from the femoral artery, and arterial 13N activity was measured by coincidence type gamma detection system for the input function. Nitrogen-13 myocardial uptake was calculated by dividing the myocardial 13N activity by the integral value of the input function. RESULTS: Three or four contiguous cross-sectional myocardial images were obtained after 13N-ammonia injection. The left ventricular wall and cardiac cavity were clearly visualized. Moreover, initial passage of the tracer through the heart was obtained with serial 10-sec PET images. Nitrogen-13 myocardial uptake correlated well with flow measured with microspheres (r = 0.88). CONCLUSION: Our cardiac PET system can be used for in vivo imaging and quantitation of MBF in small animals and may play an important role in the future study of animal models of cardiovascular diseases.

Adenosine↗
PubMed1997

HIV type 1 V3 variation dynamics in vivo: long-term persistence of non-syncytium-inducing genotypes and transient presence of syncytium-inducing genotypes during the course of progressive AIDS.

We performed a population-based sequence analysis of the envelope V3 region of human immunodeficiency virus type 1 (HIV-1) in two infected hemophiliacs. The study was conducted over 6-9 years, extending from the asymptomatic phase to AIDS. In both patients, serial analysis showed that the V3 population at the initial stage consisted exclusively of putative non-syncytium-inducing (NSI) genotypes. Several of these clones continued to be present without change for many years until the terminal stage and often represented the dominant species in the population at each time interval. On the other hand, syncytium-inducing (SI) genotypes were initially absent but appeared shortly before severe depletion of CD4+ T cells and their proportion in the population appeared to correlate with the viral load. In sharp contrast to NSI genotypes, SI genotypes displayed a significantly shorter presence. Thus, rapid gross population changes were found in SI genotypes, which were particularly frequent in the asymptomatic phase and less frequent in the terminal stage. Furthermore, the ratio of nonsynonymous nucleotide substitutions per synonymous substitutions in the V3 region in SI genotypes was higher than the corresponding value of NSI genotypes and the phylogenetic tree analysis revealed that a longer branch length was observed in SI genotypes than in NSI genotypes. These results suggest that there might be a stronger pressure for selection on SI viruses than on NSI viruses during the high CD4 counts on the contrary to the fact that emergence of SI genotypes was well correlated with the rapid decline of CD4 count.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Fluorescence detection of calcium-binding proteins with quinoline Ca-indicator quin2.

We have established a fluorescence method to detect calcium-binding proteins by making use of the quinoline Ca indicator quin2. Authentic calcium-binding proteins were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then electrophoretically transferred onto polyvinylidene difluoride membranes. Transfers were incubated with nonradioactive calcium ions, then with quin2 to detect the calcium-binding proteins as fluorescent bands by illumination with UV light. Calmodulin and parvalbumin of EF hand conformation calcium-binding type were clearly identified. Quin2 distinguished smooth muscle alpha-actinin from skeletal muscle alpha-actinin; the former was faintly fluorescent, having a low affinity for calcium ions. In whole myofibril preparations from skeletal muscles, troponin-C, connectin (titin), and nebulin were intensely fluorescent, being shown to have calcium-binding ability. The fluorescence method is an accurate, safe, and simple procedure to detect the binding of calcium ions to proteins following electrophoresis. The overlay technique described can be completed within 15 h and detects as little as 38 ng/well of troponin-C in the starting sample.

Actinin↗