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Biomedical subjects

T Ikeda

Publications and source records attributed to T Ikeda.

At least 37 records · Page 2Linked to original sources

[Successful resection of left ventricular myxoma in a toddler; report of a case].

A 4-year-old girl was found to have large left ventricular myxoma without any tumor-related symptoms. She underwent an urgent surgery and the myxoma was successfully removed through a left ventriculectomy. Great care was taken to prevent tumor-embolization during surgery, and to resect the endocardium attaching directly to the tumor. Future surveillance of this case warrants our operative technique described in this report.

Cardiac Surgical Procedures↗

Flood management under climatic variability and its future perspective in Japan.

Devastating magnitudes of flood disasters have been occurring in various areas of Japan, and their impact has been increasing in recent years. Looking ahead, it is foreseen that rainfall and its patterns will be altered due to the climate change accompanied by global warming, and there is concern that the intensity and frequency of flood disasters might be exacerbated. This paper aims to introduce flood characteristics and management policies in Japan that have been undertaken for a long time in order to mitigate these recurrent flood disasters. It also highlights extremely devastating floods in some areas that occurred under recent climate variability, and to address the progress in the assessment of hydro-meteorological tendencies and in the promotion of dialogue among climatologists and hydrologists. Lastly, a new initiative to establish an intemational centre on water-related hazards and its risk management is presented.

Climate↗

[Successful implantation of a metal coronary angioplasty stent for bronchomalacia of the right tracheal bronchus associated with right isomerism complex in an early infant].

One-month-old boy had severe emphysema of the right upper lobe due to the stenotic tracheal bronchus compressed between the distorted right patent ductus arteriosus (PDA) and the right aortic arch associated with right isomerism complex. He underwent a left modified Blalock-Taussig shunt and a division of the PDA on cardiopulmonary bypass. Extracorporeal lung support (ECLS) was introduced because of severe hypoxemia caused by remaining bronchomalacia of the tracheal bronchus. On postoperative day 3, a metal coronary angioplasty stent was implanted at the stenotic lesion under fluoroscopic and bronchoscopic guidance. He was successfully weaned from ECLS and then respirator after the implantation. This simple stenting procedure might be an effective alternate in the treatment of bronchomalacia or bronchial stenosis in early infancy.

Angioplasty↗

[Simulation of lung lobe resection with personal computer].

Various patterns of branching are seen for pulmonary arteries and veins in the lung hilum. However, thoracic surgeons usually cannot expect to discern much anatomical detail preoperatively. If the surgeon can gain an understanding of individual patterns preoperatively, the risks inherent in exposing the pulmonary vessels in the hilum can be avoided, reducing invasiveness. This software will meet the increasing needs of them in video-assisted thoracoscopic surgery (VATS) which prefer lesser dissections of the vessels and bronchus of hilum. We have produced free application software, where we can mark on pulmonary arteries, vein, bronchus and tumor of the successive images of computed tomography (CT). After receiving a compact disk containing 60 images of 2 mm CT slices, from tumor to hilum, in DICOM format, we required only 1 hour to obtain 3-dimensional images for a patient with other free software (Metasequoia LE). Furthermore, with Metasequoia LE, we can simulate cut the vessels and change the figure of them 3-dimensionally. Although the picture image leaves much room for improvement, we believe it is very attractive for residents because they can simulate operations.

Computer Simulation↗

[Modified technique creating fenestration in the extracardiac Fontan completion; kissing anastomosis].

Acute or subacute occlusion of a fenestration between the Fontan chamber and the atrium causes low cardiac output status, sustained pleural effusion, and protein losing enteropathy in critical cases. To achieve reliable and long patency of the fenestration in extracardiac Fontan operations, we modified our technique for creating a fenestration, namely "kissing" anastomosis, in which the atrial incision is directly sutured to the surface of the extracardiac conduit leaving a few millimeters outside from the edge of the punched-out hole (fenestration). We applied this modification in 2 cases. The diameter of the hole is 4 mm (case 1) and 3 mm (case 2). The patients were anticoagulated by warfarin potassium after the surgery. The fenestrations were patent at 3- (case 1) and 1-month (case 2) after the surgery. Peripheral oxygen saturations at discharge were 86 (case 1) and 88% (case 2). There was no death or major complication. The described procedure is an effective alternative to maintain patency and function of the fenestration in extracardiac Fontan operations.

Anastomosis, Surgical↗

[Prophylactic treatment of oral sildenafil citrate for pulmonary hypertension in an infant treated with inhaled nitric oxide after open-heart surgery].

A 3-month-old boy with coarctation of the aorta (CoA), ventricular septal defect (VSD), atrial septal defect, and severe pulmonary hypertension (PH) underwent one-stage repair consisting of patch closure of VSD and coarctation repair. Inhalation of nitric oxide (iNO) was commenced to treat residual severe PH on the day of the operation. Oral sildenafil citrate was commenced on the day 1 and iNO was gradually weaned off on the day 3. There was no "rebound", severe increase in pulmonary artery pressure, which commonly occurs after discontinuation of iNO. Then the patient was extubated without any difficulties or recurrent PH. The oral sildenafil citrate therapy was ceased on the day 8. Prophylactic use of oral sildenafil citrate for PH might be an useful alternative to shorten the duration of iNO therapy and intensive care unit (ICU) stay in the selected patients after congenital open heart surgery.

Administration, Inhalation↗

Differential gene-expression profiles associated with gastric adenoma.

Gastric adenomas may eventually progress to adenocarcinomas at varying rates. The purpose of the present study was to identify gene-expression profiles linked to the heterogeneous nature of gastric adenoma as compared to adenocarcinoma. Suppression subtractive hybridisation analysis was performed to extract relevant genes from two cases of low- and high-grade gastric adenomas. The identified genes were quantified by RT-PCR in 14 low-grade adenoma, nine high-grade adenoma and nine adenocarcinoma samples, followed by hierarchical clustering analysis to separate tumours into groups according to their gene-expression profiles. Nine genes previously implicated in carcinogenesis in a variety of organs, including three genes related to gastric adenocarcinoma, were identified. The overexpression of these genes in gastric adenoma has not been reported previously. The clustering analysis of these nine genes across 32 cases identified three groups, one of which consisted primarily of adenocarcinomas, whereas the other two groups consisted of adenomas. One group of adenomas, characterised by larger tumour size, exhibited gene-expression profiles of an intestinal cell lineage implicated in the pathogenesis of an intestinal-type gastric adenocarcinoma. Another adenoma group consisting of low-grade adenomas with smaller tumour size exhibited a unique expression profile. In conclusion, clustering analysis of expression profiles using a limited number of genes may serve as molecular markers for gastric adenoma with different biological properties. Although the prognostic values of these gene-expression profiles need to be evaluated in further follow-up study of adenoma cases, these findings add new insights to (a) our understanding of the pathogenesis of gastric tumours, (b) the development of specific tumour markers for clinical practice, and (c) the design of novel therapeutic targets.

Adenocarcinoma↗

Clinical significance of alendronate in postmenopausal type 2 diabetes mellitus.

OBJECTIVES: To examine early changes in biochemical markers of bone turnover and bone mineral density (BMD) in a clinical trial of anti-resorptive agent alendronate versus alfacalcidol in postmenopausal women with type 2 diabetes mellitus. METHODS: 12 subjects (mean age; 73.1 +/- 6.3 yrs, duration of diabetes; 13.2 +/- 3.7 yrs) were administered alendronate sodium (5 mg/day) and 12 subjects (mean age; 70.7 +/- 7.8 yrs, duration of diabetes; 12.8 +/- 2.0 yrs) were administered alfacalcidol (0.5 microg/day) for 12 months. Urinary N-telopeptide cross-linked collagen type I (NTx), one of biochemical markers, and radial bone mineral density (BMD) were measured as a marker of bone turnover. RESULTS: After 12 months, urinary NTx did not change in women with alfacalcidol treatment, however urinary NTx significantly decreased after alendronate treatment. The BMD significantly decreased by 3.33% (p<0.05) in women with alfacalcidol treatment, while the BMD did not decrease in women with alendronate treatment. CONCLUSION: Alendronate that produces reduction in urinary NTx and inhibition of decrease in BMD may have a clinical significance to reduce the risk of bone fracture in postmenopausal type 2 diabetic women.

Aged↗

Diurnal variation in microcirculation of ocular fundus and visual field change in normal-tension glaucoma.

PURPOSE: Diurnal variations in microcirculation of the ocular fundus in normal-tension glaucoma (NTG) were examined to compare with the normal control eyes. The correlation between progression of visual field impairment and diurnal variations in ocular circulation was also studied. METHODS: The subjects were 12 patients with NTG and 12 normal controls. Blood pressure (BP), intraocular pressure (IOP), ocular perfusion pressure (OPP), and square blur rate (SBR), an index of microcirculation acquired by the laser speckle method, were measured at 9 a.m. (morning), 3 p.m. (afternoon), and 9 p.m. (night). Diurnal variations in SBR were tested using the Friedman test and Wilcoxon signed ranks test. On the other hand, diurnal variations in BP, IOP, and OPP were tested by the analysis of variance. The visual field was evaluated at the same time as determining diurnal variation and again about 9 months later to calculate the change. The correlation between variation ratio in SBR and the change in visual field was examined by simple regression. RESULTS: A significant decrease (P=0.04) was found in SBR at night, as compared with the morning value, in the optic nerve head (ONH) of NTG, although no significant diurnal variations were found in SBR either in the choroid-retina or in normal control eyes. Other parameters showed no significant diurnal variations. The larger diurnal variation was in SBR of the ONH, and the more exacerbated visual field impairment was (r=0.59, P=0.04). CONCLUSION: These findings suggest that diurnal variations in the microcirculation of the ONH may play a role in the progression of NTG.

Aged↗

Autoantibodies to REG, a beta-cell regeneration factor, in diabetic patients.

BACKGROUND: Regenerating gene (Reg) product, Reg, acts as an autocrine/paracrine growth factor for beta-cell regeneration. The presence of autoimmunity against REG may affect the operative of the regenerative mechanisms in beta cells of Type 1 and Type 2 diabetes patients. We screened sera from Type 1 and Type 2 diabetes subjects for anti-REG autoantibodies, searched for correlations in the general characteristics of the subjects with the presence of anti-REG autoimmunity, and tested the attenuation of REG-induced beta-cell proliferation by the autoanitibodies. MATERIAL AND METHODS: We examined the occurrence of anti-REG autoantibodies in patients' sera (265 Type 1, 368 Type 2 diabetes patients, and 75 unrelated control subjects) by Western blot analysis, and evaluated inhibitory effects of the sera on REG-stimulated beta-cell proliferation by a 5'-Bromo-2'-deoxyuridine (BrdU) incorporation assay in vitro. RESULTS: Anti-REG autoantibodies were found in 24.9% of Type 1, 14.9% of Type 2 and 2.7% of control subjects (P = 0.0004). There were significant differences between the autoantibody positive and negative groups in the duration of disease in the Type 1 subjects (P = 0.0035), and the age of onset in the Type 2 subjects (P = 0.0274). The patient sera containing anti-REG autoantibodies significantly attenuated the BrdU incorporation by REG (35.6 +/- 4.06% of the control), whereas the nondiabetic sera without anti-REG autoantibodies scarcely reduced the incorporation (88.8 +/- 5.10%). CONCLUSION: Anti-REG autoantibodies, which retard beta-cell proliferation in vitro, are found in some diabetic patients. Thus, autoimmunity to REG may be associated with the development/acceleration of diabetes in at least some patients.

Adolescent↗

Effect of metal strengthener length on stress distribution in acrylic denture bases: a finite element study.

This study investigated the influence of metal strengthener length on stress created in acrylic denture bases in relation to location of the vertical support to the dentures. Finite element analysis was conducted to calculate stress generated in the straps of 2 mm-thickness and 18 mm-width that were reinforced with metal strengtheners of five different lengths. A vertical biting force of 60 N was directed on one end of each strap, while the other end was fixed. Vertical movements were restricted at one of the three support locations between the centre of the strap and the loading site. When the straps were vertically supported near the loading site, greater maximum tensile stresses were seen in the straps with relatively short strengtheners than those shown in the straps with longer strengtheners. The metal strengtheners with sufficient length may provide a preventive denture design against the acrylic fractures.

Acrylic Resins↗

Bond strength of simplified-step adhesives to enamel prepared with two different diamond burs.

BACKGROUND: Self-etching primers are reported to produce considerable etching on flat enamel surfaces. However, little is known about the influence of different enamel surface textures. In this study the influence of grinding enamel on bond strength of two all-in-one and one two-step adhesives was investigated. METHODS: Resin composite was bonded to the ground enamel of extracted human third molars that was reduced 0.5 mm from the buccal or lingual surfaces using either regular- or superfine-grit diamond burs with each of the three adhesives. After 24 hours in 37 degrees C water, the specimens were sectioned into slabs of 0.7 mm thickness, trimmed to an hourglass configuration, and subjected to microtensile bond strength (MTBS) testing. RESULTS: For all adhesive systems, MTBS to enamel ground with a regular-grit diamond bur was not significantly different from that with a superfine-grit diamond bur. The etching patterns of these adhesives were partly varied according to the aggressiveness of the adhesives. CONCLUSION: The use of two different burs does not affect the tensile bond strength of the adhesives to enamel.

Acid Etching, Dental↗

[Clinical study on video-assisted thoracic surgical simultaneously stapled subsegmentectomy for peripheral lung tumors].

BACKGROUND: The purpose of this study is to confirm the safety and validity of video-assisted thoracic surgical simultaneously stapled subsegmentectomy (simultaneously stapling of all subsegmental bronchi and vessels in their natural construction). METHODS: The clinicopathologic information of the 10 patients who underwent video-assisted thoracic surgical simultaneously stapled subsegmentectomy for primary lung cancer (6) and metastatic lung tumor (4) were reviewed retrospectively. The patient population consisted of 7 men and 3 women with a mean age of 70.2 years. RESULTS: Median operative time was 201 minutes. Average blood loss was 76 ml. Mean duration of thoracic drainage was 3 days. There was no surgical mortality. Recurrence was diagnosed in 2 of 6 lung cancer patients (each of contralateral lung metastasis and brain metastasis), and 1 of 2 died 26 months after the operation. All patients have been followed for a mean period of 30.4 months with no local recurrence. CONCLUSIONS: Video-assisted thoracic surgical simultaneously stapled subsegmentectomy is safe and may be an acceptable alternative to segmentectomy, and wedge resection for strictly selective patients with peripheral lung tumors.

Adenocarcinoma↗

[Stenting in obstruction of superior vena cava; clinical experience with the self-expanding endovascular prosthesis].

From August 1997 to December 2002, 14 consecutive patients with superior vena cava syndrome with the self-expanding endovascular prosthesis. Diagnoses were adenocarcinoma in 6, small cell carcinoma in 4, squamous cell carcinoma in 1, metastatic lung cancer in 2, and invasive thymoma in 1. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured on their admission and perioperative period. Expecting only 1 patient complete symptomatically relieved within 3 days of stent implantation. Superior vena cava pressure or radial pressure of the stent was sufficient to relieve obstruction. Preoperative ANP level were normal, BNP level were increased. Postoperatively both ANP level and BNP level were slightly increased under intravenous dopamine hydrochloride. Implantation of the self-expanding stent endovascular prosthesis for superior vena cava syndrome provides rapid symptomatic relief and improves the patient's quality of life.

Adult↗

[Squamous cell carcinoma caused by dysplasia on the bullous wall].

We experienced a squamous cell lung carcinoma caused by dysplasia around the bullous wall after right upper lobectomy by tuberculosis. A case is 70 years old male who was resected right upper lobe caused by tuberculosis 50 years ago. He was pointed out an abnormal shadow on the chest X-ray in March 2002. There were bullous change in right lung field on the chest computed tomography (CT). There was appeared a tumor contiguous to the bullous wall. A part of bullous wall surrounding the tumor was thickened bronchio-alveolar lavage gave proof of squamous cell carcinoma. Right basal segmentectomy and subcarinal lymph node dissection was done, because of severe adhesion a right middle lobe. Radiation therapy at the mediastinum is performed, because of positive subcarinal lymph nodes. It is rare case of squamous cell carcinoma caused by dysplasia, we reported.

Aged↗

[Isolated coronary artery bypass grafting in octogenarians].

We evaluate the outcomes of isolated coronary artery bypass grafting (CABG) in high-risk octogenarians. There are 20 cases in 5 years, which contain 1 re-operation case, and 10 emergency cases. Nineteen cases were performed off-pump CABG (OPCAB), and conventional CABG was performed for only 1 case because of unstable hemodynamics with intraaortic balloon pumping (IABP). We generally performed CABG with aorta no-touch technique. There is no death case, and no serious complication like stroke. We used 23 artery and 11 vein grafts for CABG, and mean number of grafts per patient was 1.8+/-0.7. And "hybrid therapy" with percutaneous transluminal coronary angioplasty (PTCA) was done for 5 cases. Octogenarians are at increased risk for perioperative morbidity and mortality after CABG, but we have performed OPCAB for them and have had good results. And we think that aorta no-touch technique, proper selection and use of graft are important.

Aged↗

[Oral sildenafil citrate as an effective alternate in the treatment of postoperative pulmonary hypertensive crisis after congenital heart surgery].

A five-month-old girl of Down syndrome underwent a corrective surgery for complete atrioventricular septal defect. Her postoperative course was complicated with pulmonary hypertensive (PH) crises despite nitroglycerin (NTG) infusion and inhaled nitric oxide (NO). Sildenafil citrate, a phosphodiesterase 5 inhibitor, was administered through a nasogastric tube at a starting dose of 0.3 mg/kg by stepwise increment to the maximum dose of 2 mg/kg 4 hourly. Sildenafil citrate dramatically lowered pulmonary arterial pressure and the patient was weaned from NTG and NO without PH crisis. There was no side effect after sildenafil citrate administration. Oral sildenafil citrate is a safe and potent adjunct to the existing therapies for postoperative PH in infants after open heart surgery.

Administration, Inhalation↗