Biomedical subjects
Publications and source records attributed to Y Imai.
Elongation of the pterygoid hamulus is a rare syndrome that shows various and complex symptoms in the palatal and pharyngeal region. A case of elongated pterygoid hamulus syndrome in a 47-year old man is reported here.
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Tissue engineering (TE) is a new discipline that offers the potential to create replacement structures from autologous cells and biodegradable polymer scaffold. Various vascular and valvular grafts have been tried to create with this TE approach. In clinical use of this technique, harvested and cultured cells have to keep viability until implantation as tissue engineered tissue. But few research for cryopreservation of vascular mixed cells has been performed. So, we investigated the proper method for cryopreservation of vascular mixed cells harvested from femoral artery and vein of dogs. Cells were cultured and divide into three groups, A: cryopreserving in 5% dimethylsulfoxide (DMSO), hydroxyethyl starch (HES), and fetal bovine serum (FBS) with -80 degrees C freezer; B: cryopreserving in 10% DMSO and FBS with programmed freezer; C: control (continuous culture in media). After rapid thawing at 40 degrees C, group A showed higher viability than group B with flow cytometry. The results means that vascular mixed cells can be successfully cryopreserved in the DMSO/HES mixture simply and inexpensively, without rate controlled freezing.
Disseminated bone marrow metastasis of cancer is a critical condition, frequently complicated by disseminated intravascular coagulation (DIC). A 32-year-old man with gastric cancer was diagnosed as having disseminated bone marrow metastases. Bone scintigraphy demonstrated many abnormal radionuclide accumulations in the whole body. Bone marrow aspiration revealed cancer cells. Bone marrow scintigraphy with 111In-Cl3 demonstrated central marrow failure and peripheral expansion. The remission of DIC was observed after sequential methotrexate and 5-FU therapy, then uptake of radionuclide in the central bone marrow was remarkably improved by bone marrow scan. After thirteen anti-cancer chemotherapies, recurrence of DIC was suspected because of the reduction of blood platelet count. Nevertheless, repeated bone marrow scan still demonstrated the central bone marrow clearly. The patient discharged from our hospital without the recurrence of DIC. We considered bone marrow scintigraphy is useful in the detection of disseminated bone marrow metastases of cancer and monitoring the effectiveness of chemotherapy.
Double-switch operation was performed in 76 patients with congenitally corrected transposition of the great arteries at the Heart Institute of Japan, Tokyo Women's Medical University. Detailed surgical techniques of Mustard and Senning procedures for inlet switch, as well as arterial switch operation, pulmonary reconstruction by direct right ventricular-pulmonary arterial anastomosis, and external conduit repair for outlet switch are described in detail.
A 58-year-old woman was admitted to our hospital because of recurrent fever, severe cough and sputum. Chest radiological examinations showed diffuse reticulonodular opacities in both lung fields. Interstitial pneumonia with probable polymyositis was diagnosed. Serum surfactant protein (SP)-A, SP-D and KL-6, which are new interstitial lung disease markers, showed values significantly higher than cutoff levels. The markers increased more in parallel with the rapid development of respiratory insufficiency, CPK level, myalgia and proximal muscle weakness. Treatment with a high dose of corticosteroid and the following gradual decrease over 8 months led to clinical and radiological improvement, with normalization of values of the markers. These markers may therefore be reliable indicators of therapeutic success. However, these markers underwent different respective changes during the first 2 months. SP-A reached a maximum at the start of the treatment, while SP-D and KL-6 peaked at 5 and 10 days, respectively, after the treatment was initiated. This discrepancy demonstrates that the markers reach the bloodstream by diverse mechanisms and are useful for analyzing pathophysiological alterations in the lung in the early stages of treatment.
During the past three decades, significant advances have been made in the field of transplantation. However, clinical obstacles such as donor scarcity, cost, infection and life-long immunosuppression(especially within the pediatric age group) have become the major limitations for organ transplantation. This article discusses the recent progresses as well as the remaining challenges in tissue engineering that may enable such technology to replace organ transplantation. Additionally, we describe a practical method for tissue engineering in the field of cardiovascular surgery.
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More than 30 years has passed since Kawasaki disease was recognized as an independent disease entity, but the cardiovascular complications of Kawasaki disease are still not well known. We report an 22-year-old woman who underwent triple coronary artery bypass grafting because of a coronary artery aneurysm and multiple coronary artery stenoses, 22 years after the diagnosis of Kawasaki disease. A 2 cm coronary artery aneurysm due to Kawasaki disease was diagnosed when she was 10 years old, when she first presented with the symptom of dyspnea on effort. Since then, she was followed at the outpatient clinic. When she was 19 years old, the first coronary catheterization was performed. Two years later, the second coronary catheterization revealed progression of coronary artery disease. Therefore, coronary artery bypass grafting was performed. This case is rare from the point of view of long-term progression of coronary artery disease.
Apoptosis induced by ionizing irradiation of the developing mouse brain was investigated by using histology, analysis of DNA fragmentation on agarose gel and electron microscopy. A TUNEL-labeled index (L.I.) was calculated from the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labeling (TUNEL) assay in 4 specific regions, cortical plate, intermediate zone, subependymal zone, and subependymal germinal matrix. The kinetics of apoptosis associated protein was examined by western blotting and immunofluorescence. C57BL/6J mice pregnant on embryonic day 14 (E14) were exposed to a single dose of 1.5-Gy irradiation. Irradiated fetal brains at E15 and E17 showed extensive apoptosis with morphological characteristics. In all 4 regions, L.I. was greater in irradiated brains than in control brains at E15 and E17. Most of TUNEL-labeled cells expressed a mature neuronal marker (NeuN) and Bax protein, which is up-regulated in irradiation-induced apoptosis. Ionizing radiation moderately enhanced expression of Bax, Bcl-xL, and Cpp32 proteins. Postnatal irradiated mice showed microencephaly as compared to age-matched mice and the weight of whole body including brain decreased moderately.
We examined the occurrence of brain infarction with hepatic arterial infusion chemotherapy for liver cancer. One hundred and eighty-one cases of hepatic arterial infusion chemotherapy were carried out for liver cancer patients in 4 hospitals associated with Osaka University 2nd Dept. of Surgery. These included metastatic (n = 103) and primary (n = 78) liver tumors. The medication was mainly 5-FU with/without CDDP and IFN. Catheters were inserted via the left subclavian artery in 106 cases and via the femoral artery in 75 cases. Among these patients, brain infarctions occurred in seven patients. Occlusions were found in the cerebellum (n = 3), thalamus (n = 1), brain stem (n = 1) and TIA (n = 2). All these patients had catheterization from the left subclavian artery. Furthermore, 64 patients of Ikeda Municipal Hospital were examined and analyzed for brain infarction, in order to eliminate the difference between facilities (all patients in Ikeda Municipal Hospital were catheterized via the left subclavian artery). Many more brain infarctions occurred in metastatic liver cancer patients than in primary liver cancer patients. The hemostasis function deteriorated in primary liver cancer patients, and is thought to be involved in the brain infarction. Six of seven cases of brain infarction occurred in vertebral artery supply area. It may be that the occurrence of brain infarction was related to the flow of the blood vessels.
INTRODUCTION: Although fatty infiltration of liver is a benign process that generally results from chronic alcohol uptake or obesity, such lifestyle factors may lead to chronic disease. Measuring the fat concentration in liver may therefore prove useful in assessing disease status. In this study, we report the usefulness of line scan echo planar spectroscopic imaging (LSEPSI) for this problem. METHODS: Rapid successive column sampling was accomplished using orthogonal slice-selective 90 degrees and 180 degrees pulses and echo planar spectral/spatial encodings. Phantom and clinical studies of 13 patients suspected of having fatty liver were carried out with LSEPSI. Estimated fat fractions obtained with LSEPSI were compared with ultrasound findings. RESULTS: The results showed a good correlation between the actual fat content of phantoms and the estimated fat fraction obtained with LSEPSI (r = 0.95). In the clinical study, the estimated fat fraction tended to rise as the US grade of fatty liver increased. DISCUSSION: LSEPSI is largely free from T1 and T2 relaxation owing to its infinite TR and minimal T2 weighting. Thus, there is no need for relaxation analysis. In addition, the lack of phase encoding reduces motion-related ghosting artifacts. Rapid fat/water spectral quantification of liver with this technique is useful for fatty liver assessment in a clinical setting.
Early colorectal neoplasms, especially flat-type and depressed-type lesions, should be treated with an EMR technique. In general because depressed-type lesions, in contrast to flat-type or protruded-type lesions, tend to invade the submucosa rapidly, they ought to be treated by EMR at an early stage. Histopathologically in the case of lesions that only minimally invade the submucosa without vessel invasion (sm1a and sm1b without vessel invasion), a treatment can be completed with EMR. Massive submucosal invasive cancers ought to be resected by surgical treatment because of the risk of recurrence or metastasis. In addition, pit pattern diagnosis with magnifying colonoscopy is useful to determine a therapeutic method for colonic neoplasms. Lesions with the type VN pit pattern represent malignancy and usually invade the submucosa massively, so it is better to treat them surgically from the outset. Endoscopic mucosal resection should be conducted under fully controlled endoscopy to prevent complications. EMR is a superior therapeutic method and will be performed frequently in the future. It is necessary for colonoscopists to determine a suitable therapy for each colorectal neoplastic lesion. They also need to master the EMR technique in the correct manner.
Cystic fibrosis (CF) takes its name from the pathological changes that occur in the pancreas. Cystic fibrosis transmembrane conductance regulator (CFTR) is highly expressed in the pancreatic ductal epithelium and plays a key role in ductal HCO(3)(-) secretion. In humans, the pancreatic duct secretes near isotonic NaHCO(3). Experimental data suggests that HCO(3)(-) secretion occurs via apical Cl(-)/HCO(3)(-) exchangers working in parallel with Cl(-) channels (CFTR and calcium activated chloride channels, CaCC). Programming the currently available experimental data into our computer model (based on network thermodynamics) shows that while the anion exchanger/Cl(-) channel mechanism will produce a relatively large volume of a HCO(3)(-)-rich fluid, it can only raise the luminal HCO(3)(-) concentration up to about 70 mM. To achieve secretion of about 150 mM NaHCO(3) it is necessary to modulate the properties of the apical membrane transporters as the secreted fluid flows down the ductal system. On the basis of our computer simulations, we propose that HCO(3)(-) secretion occurs mainly via the exchanger in duct segments near the acini (luminal HCO(3)(-) concentration up to about 70 mM), but mainly via channels further down the ductal tree (raising luminal HCO(3)(-) to about 150 mM). We speculate that the switch between these two secretory mechanisms is controlled by a series of luminal signals (e.g. pH, HCO(3)(-) concentration) acting on the apical membrane transporters in the duct cell.
The thermal properties of the dispersion of sodium salt of dimyristoylphosphatidylglycerol (NaDMPG) in water have been investigated as functions of incubation temperature and aging time by DSC, XRD, sodium ion activity, pH, zeta-potential, and IR measurements. The DSC charts for NaDMPG dispersions incubated below 30 degrees C showed an endothermic peak at 31.7 degrees C with a small shoulder peak at Tm (gel-liquid crystal transition temperature: 23.5 degrees C). The temperature of 31.7 degrees C coincides with the T* temperature at which a high-order transition in the NaDMPG bilayer assembly has been found to occur in our previous studies. However, no peak was observed for the dispersions incubated above 32 degrees C. These results indicate that thermal properties of NaDMPG bilayers definitely differ below and above the T* temperature. The dispersion which had been once incubated at 40 degrees C for 24 h never showed the endothermic peak at T* even after the further aging at 3 degrees C for 12-day. Namely, the NaDMPG bilayer assembly exhibits an intensive thermohysteresis. The XRD charts for the NaDMPG dispersions incubated at 25 degrees C showed a sharp X-ray diffraction pattern corresponding to the repeat distance of d = 4.75 nm regardless of their aging time, while the dispersions incubated at 40 degrees C had no diffraction peak until 9-day elapsed. After 10-day aging at 40 degrees C, however, a diffraction peak corresponding to d = 5.55 nm clearly appeared. In the DSC measurements for the dispersion incubated at 40 degrees C, a few endothermic peaks began to appear between Tm and T* after approximately 7-day aging. Then, they shifted toward higher temperatures and finally converged into a single peak at 40-42 degrees C after 14-day aging. These XRD and DSC peaks observed after a long period of aging time above T* suggest that conformations of the hydrophilic groups and the hydrocarbon chains in the NaDMPG bilayers take a more tight and closer arrangement very slowly via an intermediate state above T*, and a new gel phase of the bilayers is consequently formed, the transition temperature (T(I) temperature) of which is 40-42 degrees C. A molecular interpretation for such transition processes in the bilayer assembly of NaDMPG dispersions has been proposed on the basis of pH, sodium ion activity, zeta-potential, IR data, etc.
BACKGROUND: Although the clinical significance of systolic-diastolic hypertension and isolated systolic hypertension has been established, the significance of isolated diastolic hypertension has not been fully investigated. OBJECTIVE: To clarify the prognostic significance of isolated systolic and isolated diastolic hypertension as assessed by self-measurement of blood pressure (BP) at home (home BP measurements), which has a better reproducibility and prognostic value than casual BP measurements in the general population. SUBJECTS AND METHODS: We obtained home BP measurements for 1913 subjects aged 40 years or older, then followed up their survival status (mean, 8.6 years). We classified the subjects into the following 4 groups according to their home BP levels: systolic-diastolic hypertension, isolated systolic hypertension, isolated diastolic hypertension, and normotension. The prognostic significance of each type of hypertension for the risk of cardiovascular mortality risk was investigated using a Cox proportional hazards regression model adjusted for possible confounding factors. RESULTS: The risk for isolated systolic hypertension and systolic-diastolic hypertension were significantly higher than the relative hazard for normotension, while isolated diastolic hypertension was associated with no significant increase in risk. Home pulse pressure measurement was also independently associated with an increase in the risk of cardiovascular mortality. CONCLUSIONS: Isolated diastolic hypertension, as assessed by home BP measurements, carried a low risk of cardiovascular mortality, similar to that found in subjects with normotension, suggesting that the prognosis of hypertension would be improved by treatment focused on systolic rather than on diastolic home BP measurements. To our knowledge, this study is the first to demonstrate the clinical significance of pulse pressure as assessed by home BP measurement. Arch Intern Med. 2000;160:3301-3306.
Ca(2+), which enters cardiac myocytes through voltage-dependent Ca(2+) channels during excitation, is extruded from myocytes primarily by the Na(+)/Ca(2+) exchanger (NCX1) during relaxation. The increase in intracellular Ca(2+) concentration in myocytes by digitalis treatment and after ischemia/reperfusion is also thought to result from the reverse mode of the Na(+)/Ca(2+) exchange mechanism. However, the precise roles of the NCX1 are still unclear because of the lack of its specific inhibitors. We generated Ncx1-deficient mice by gene targeting to determine the in vivo function of the exchanger. Homozygous Ncx1-deficient mice died between embryonic days 9 and 10. Their hearts did not beat, and cardiac myocytes showed apoptosis. No forward mode or reverse mode of the Na(+)/Ca(2+) exchange activity was detected in null mutant hearts. The Na(+)-dependent Ca(2+) exchange activity as well as protein content of NCX1 were decreased by approximately 50% in the heart, kidney, aorta, and smooth muscle cells of the heterozygous mice, and tension development of the aortic ring in Na(+)-free solution was markedly impaired in heterozygous mice. These findings suggest that NCX1 is required for heartbeats and survival of cardiac myocytes in embryos and plays critical roles in Na(+)-dependent Ca(2+) handling in the heart and aorta.
Autosomal recessive juvenile parkinsonism (AR-JP) is caused by mutations in the parkin gene. Parkin protein is characterized by a ubiquitin-like domain at its NH(2)-terminus and two RING finger motifs and an IBR (in between RING fingers) at its COOH terminus (RING-IBR-RING). Here, we show that Parkin is a RING-type E3 ubiquitin-protein ligase which binds to E2 ubiquitin-conjugating enzymes, including UbcH7 and UbcH8, through its RING-IBR-RING motif. Moreover, we found that unfolded protein stress induces up-regulation of both the mRNA and protein level of Parkin. Furthermore, overexpression of Parkin, but not a set of mutants without the E3 activity, specifically suppressed unfolded protein stress-induced cell death. These findings demonstrate that Parkin is an E3 enzyme and suggest that it is involved in the ubiquitination pathway for misfolded proteins derived from endoplasmic reticulum and contributes to protection from neurotoxicity induced by unfolded protein stresses.