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Biomedical subjects

Y Imai

Publications and source records attributed to Y Imai.

At least 433 records · Page 24Linked to original sources
PubMed1997

Histocompatibility antigens and polymyalgia rheumatica in a Japanese patient with insulin-dependent diabetes mellitus.

A 30-year-old Japanese female developed insulin-dependent diabetes mellitus (IDDM). She later complained of muscle pains at the age of 37. Erythrocyte sedimentation rate and C-reactive protein were abnormal, with negative antinuclear antibody and rheumatoid factor tests. The diagnosis of polymyalgia rheumatica (PMR) was made. She had HLA phenotypes including A2 and without DR4, consistent with common types of Japanese PMR. Her DNA typing included DQB1*0303 which is positively associated with Japanese IDDM. It seems likely that she suffered from these diseases at a young age on the basis of having the HLA-susceptibility to both PMR and IDDM.

Adult↗
PubMed1997

A method to estimate the transient interstitial osmolarity change upon application of osmotic stress in perfused rat submandibular gland.

Transient osmolarity changes in the interstitium of perfused rat submandibular glands were estimated by measurement of the interstitial Cl- concentration ([Cl-]ECF) with an Ag-AgCl electrode upon application of osmotic stress by the addition or subtraction of NaCl. A simple model was used to describe the interstitial osmolarity changes upon the application of osmotic stress. The measured [Cl-]ECF values and interstitial osmolarities were fit well by an exponential function derived from the model. The good fit of the theoretical curve indicates that this model describes adequately the changes in interstitial osmolarity after switching the perfusate osmolarity to a new value.

Animals↗
PubMed1997

Development of cancer vaccine by tumor rejection antigens.

Identification of the MAGE genes allowed us the molecular approach to identify genes encoding tumor rejection antigens expressed on human cancer cells. MAGE-1 proteins are normal tissue antigens compartmentalized in the particular testicular cells playing an important role in the early phase of the spermatogenesis. The MAGE-1, -2, -3, -4 and -6 genes are preferentially expressed in many different cancers at both the mRNA and protein levels. The MAGE genes, particularly MAGE-1, became positive in relatively advanced stages of cancers and recurrent cancers. Approximately one-third to half of human cancers except for myelo-monocytic leukemia expressed at least one of these MAGE genes. The MAGE gene products shall be appropriate target molecules for development of new cancer vaccine.

Animals↗
PubMed1997

New initiator system for bonding to dentin using methylcyclohexanedione.

As a part of a series of studies to examine the role of the initiator system in dentin bonding, the effectiveness of a new polymerization initiator system consisting of 2-methyl-1,3-cyclohexanedione (MCHD) and CuCl2 in dentin bonding was investigated in terms of the effects of dentin conditioners and CuCl2 concentration formulated in MMA/PMMA resins. Curing time and tensile bond strength to bovine dentin were measured using resins composed of MMA containing 0.001-0.03 wt% CuCl2 and PMMA powder containing 2 wt% MCHD. The dentin surfaces were treated with six conditioners consisting of 10 wt% phosphoric acid or citric acid containing 0-3 wt% FeCl3 or CuCl2. The bond strengths of about 10 MPa obtained under optimal conditions were comparable to those reported for tributylborane-initiated MMA resin which is one of the most effective bonding resins available. Thus, the resin using MCHD/CuCl2 system was concluded to be very effective for dentin bonding, especially when dentin was treated with acidic conditioners containing ferric or copper chloride.

Animals↗
PubMed1997

Effect of adding ethylene glycol dimethacrylate to resin cements: durability against thermal stress of adhesion to titanium.

The present study was conducted to examine the effect of the addition of a dimethacrylate to resin cements on bond strength between titanium and resin after thermocycling. Titanium disks, polished and treated with a phosphate monomer, were bonded to acrylic rods using two types of experimental resin cements. The cements were composed of methyl methacrylate (MMA) containing a tributylborane initiator and 0-10 wt% of ethylene glycol dimethacrylate (EGDMA) and two types of polymer component of hard poly (MMA) or soft fluoropolymer (2-6F). The bonded specimens were subjected to a thermocycling test in water and then to tensile strength testing. The addition of 5% or more dimethacrylate monomer to the two MMA-based resin cements caused a drastic decrease in bond strength to the metal after the thermocycling test. The resin prepared with soft 2-6F as a polymer component was significantly more durable than the rigid type resin based on PMMA. However, even a 1% addition of ECDMA to the 2-6F resin resulted in a significant decrease in durability.

Analysis of Variance↗
PubMed1997

Effect of dimethacrylates in resin cement on durability against thermal stress of adhesion to titanium.

The present study examined the effect of crosslinking of resin cement on durability of adhesion between titanium and resin against repeated thermal stress. Titanium disks, polished and treated with a phosphate monomer, were bonded to acrylic rods with resins composed of poly (methyl methacrylate), methyl methacrylate containing 0 approximately 5% dimethacrylates or diacrylate as crosslinking agent, and a benzoyl peroxide/amine initiator system. The bonded specimens were subjected to thermocycling in water and then tensile strength testing. The addition of 5% crosslinking agent, irrespective of its type, to the resin resulted in a significant decrease in bond strength after 500 thermocycles. No significant difference in durability was revealed among the five crosslinking agents studied.

Acrylic Resins↗
PubMed1997

[Study on the surgical treatment for pulmonary metastasis from renal cell carcinoma].

BACKGROUND: Pulmonary resection for metastatic renal cell carcinoma were studied to assess the indication of surgical management. METHODS: Between January, 1981 and December 1994, 17 consecutive patients (14 men and 3 women) underwent complete pulmonary resection for metastatic renal carcinoma. Median age was 61 years (range, 45 to 73 years). Eleven were appeared lung metastasis after resection of primary tumor. Median time between nephrectomy and pulmonary resection was 32 months (range, 0 to 127 months). RESULTS: There were no operative deaths. One patient had solitary metastasis, 4 had two, 2 had three, 2 had four, one had seven, one had eight and 6 had more than twenty-two. Segmental resection was performed in 12 patients, lobectomy in 2, lobectomy and segmentectomy in 3 and segmentectomy for total lobes in 3. Four patients had another site operation of renal metastasis, brain tumor resection, chest wall and ribs resection, contra-lateral adrenalectomy and contralateral partial nephrectomy. Median follow-up was 44 months (range, 10 to 129 months). The cause specific survival rate and disease free survival after pulmonary resection was 55 and 48 percent at 5 years and 27 and 14 percent at 10 years, respectively. CONCLUSION: Pulmonary resection for metastatic renal cell carcinoma was considered effective in some selected slow-growing cases. Multiple and both lungs metastases is not contraindication and the patients under 10 metastatic focuses had good prognosis.

Aged↗
PubMed1997

The epidemiology of ambulatory blood pressure monitoring in Japan.

Ambulatory blood pressure monitoring is now being used widely in Japan. Several Japanese studies have value demonstrated that the ambulatory blood pressure is superior to the casual blood pressure in prediction of target organ damage. Ambulatory blood pressure monitoring has also been reported to be more cost effective than are casual blood pressure measurements. Nonetheless, no agreement has been reached regarding its use in clinical settings. This problem has arisen partly because no reference for ambulatory blood pressure value has been established. We reviewed several cross-sectional studies and one prospective study performed in Japan and propose tentatively a reference ambulatory blood pressure value for Japanese: 135/80 mmHg. Further prospective studies are needed in order to confirm this value in different community settings and with different prognostic parameters.

Journal Article↗
PubMed1997

Proposal of reference values for home blood pressure measurement: prognostic criteria based on a prospective observation of the general population in Ohasama, Japan.

The purpose of this study was to propose reference values, from a viewpoint of prognostic significance, for blood pressure (BP) measured at home with a semiautomated device (home BP measurement) to differentiate normotension and hypertension. We obtained home BP measurements for 1,913 population-based subjects aged 40 years and over in a rural Japanese community and followed up their survival for a mean duration of 5.0 years. There were 141 deaths during the follow-up period. The association between baseline BP values and the overall mortality was examined by Cox proportional hazards regression model, adjusted for age, gender, and the use of antihypertensive medication. The results indicated that the predictive power of home BP level for subsequent mortality was stronger than that of casual screening BP. There was a linear association between home systolic BP and mortality. The association between home diastolic BP and mortality was nonlinear and well approximated with the secondary degree equation of diastolic BP values. Based on this relation, we propose that the reference value for hypertension is 137/84 mm Hg, and normotension is below 137 mm Hg for home systolic BP and between 66 and 83 mm Hg for home diastolic BP. Home diastolic BP below 66 mm Hg should be considered as low diastolic blood pressure. In this population, home systolic BP of 137 mm Hg and home diastolic BP of 84 mm Hg corresponded to the 80th and 87th percentiles, respectively. Then, 29% of the subjects were classified as having hypertension, 52% as normotension, and 19% as low diastolic blood pressure. All previous studies proposing reference values for home BP measurement, derived from cross-sectional observations, were based on the statistical distribution of home BP values. The reference value must, however, be the one that best predicts the risk for morbidity and mortality from hypertension-related complications. This is the first report proposing reference values for home BP measurement based on prognostic criteria.

Adult↗
PubMed1997

Successful endoscopic injection sclerotherapy with N-butyl-2-cyanoacrylate following the recurrence of bleeding soon after endoscopic ligation for ruptured duodenal varices.

Bleeding from duodenal varices in a 63-yr-old man with alcoholic cirrhosis of the liver was found at endoscopy, and ligation surgery was carried out. Ten months after the operation, bleeding from the duodenal varices occurred and was treated by endoscopic ligation. However, after performing this procedure, bleeding again occurred 1 week later. Hemostasis was finally achieved by endoscopic injection sclerotherapy with N-butyl-2-cyanoacrylate. For the 22 months since the injection, the patient has been free from further bleeding. These results suggest that endoscopic injection sclerotherapy with N-butyl-2-cyanoacrylate was effective in bringing about immediate cessation of the bleeding in duodenal varices and that long-term hemostasis can be expected.

Duodenoscopy↗
PubMed1997

[A successful mitral valve replacement for a 13-year-old girl with mitral stenosis and pulmonary hypertension after renal transplantation].

Mitral valve replacement was successfully performed in a 13-year-old girl due to severely calcified mitral valve stenosis and pulmonary hypertension who had undergone renal transplantation from her father at the age of 8 years old. Although, percutaneous transluminal mitral commissurotomy had been performed for four times until January 1996, severe mitral stenosis could be relieved and she was transported to our hospital in emergency for respiratory failure caused by pulmonary edema. Then we decided to perform mitral valve replacement. The operation was done successfully using trans-septal superior approach with SJMHP 19 mmM. the blood cyclosporin levels were monitored and controlled within normal limits. This is the first successful case of pediatric open heart surgery after renal transplantation to our knowledge.

Adolescent↗
PubMed1997

[Effect of daily administration of oral etoposide for non-small cell lung cancer treated with concurrent radiation therapy].

The purpose of this study was to explore the effect of daily administration of oral etoposide (25 mg) for patients with non-small cell lung cancer treated with concurrent radiation therapy. Planned endpoints were response, survival and toxicity. Forty-one patients with non-small cell lung cancer were divided into 25 patients given daily oral etoposide (25 mg) with concurrent radiation therapy (ERT group) and 16 patients given radiation therapy alone (RT group). Etoposide was administrated in the morning throughout radiation therapy. The median total irradiated dose was 63.1 Gy in the ERT group and 64.0 Gy in the RT group. Twenty-four patients completed therapy in the ERT group and 16 in the RT group. Three (15%) ERT patients achieved complete response (CR) and 9 (45%) achieved partial response (PR). In the RT group, no patients achieved CR and 9 (69%) achieved PR. One-year survival was 22.6% with ERT and 23.0% with RT. The prognosis of stage III patients in the ERT group was worse than that in the RT group because radiation pneumonitis and radiation esophagitis were more severe with ERT. In conclusion, the ERT group had better local response but worse in survival than the RT group. Complications of ERT were severe enough to cause death in some patients. ERT had no clear advantage over RT.

Administration, Oral↗
PubMed1997

Generation and characterization of a microglial cell line, MG5, derived from a p53-deficient mouse.

We have established a cell line cloned from primary-cultured microglia obtained from p53-deficient mice. The cell line, MG5, could be grown in astrocyte-conditioned medium and has been maintained for more than a year. MG5 cells are immunocytochemically positive for Mac-1 and F4/80 antibody and express the major histocompatibility complex (MHC) class I antigen, leukocyte function-associated antigen-1, leukocyte common antigen, and intercellular adhesion molecular-1 mRNA. Interferon-gamma enhanced the expression of MHC class II antigen mRNA in MG5 cells. We previously identified a novel calcium-binding protein, Iba1 (ionized calcium-binding adapter molecule 1), which is highly and specifically expressed in cultured microglia. Iba1 protein was also immunocytochemically demonstrated in MG5 cells. The cells retained non-specific esterase activity, 5'-nucleotidase activity, acid phosphatase activity, and phagocytic ability. Like primary cultured microglia from wild-type mice, MG5 cells released nitric oxide in response to lipopolysaccharide, and actively proliferated in the presence of mitogenic factors such as macrophage-colony stimulating factor (M-CSF), granulocyte/macrophage-CSF (GM-CSF), and interleukin-3 (IL-3). Tyrosine-phosphorylation of M-CSF receptor in MG5 cells was induced by the addition of M-CSF or astrocyte-conditioned medium. These findings indicate that MG5 cells preserve the morphological, biochemical, and physiological properties of primary-cultured microglia well. The MG5 cell line will be a useful tool for studying microglial function.

5'-Nucleotidase↗
PubMed1997

[Usefulness of magnetic resonance imaging for managing patients with prosthetic carbon valve in the mitral position].

The safety, findings and clinical usefulness of magnetic resonance (MR) imaging were assessed in patients with a prosthetic carbon valve in the mitral position. In vitro deflection, heating and image distortion due to the magnetic field of a 1.5 tesla MR machine were examined in three carbon valves (CarboMedics, St. Jude Medical and Björk-Shiley valves). In vivo MR imaging of the left ventricular horizontal long-axis, vertical long-axis and short-axis views was performed by electrocardiographically synchronized spin echo and field (gradient) echo techniques in eight patients with prosthetic mitral carbon valves, consisting of six CarboMedics valves, one St. Jude Medical valve and one Björk-Shiley valve. No deflection and significant heating was seen in all three valves in vitro. Although little image distortion was shown in the CarboMedics and St. Jude Medical valves, a small distortion toward the frequency encoded direction was seen in the Björk-Shiley valve but caused no difficulty in assessing the surrounding images. Four of the eight patients had normal sinus rhythm and the other four had atrial fibrillation. The prosthetic valves were depicted as signal voids in the images taken by both spin echo and field echo techniques in vivo. Clear structural information with little image distortion of the adjacent tissues of the prosthetic valves were obtained in all patients, although the image of the Björk-Shiley valve which contained stainless steel in the frame had a slightly stronger distortion than those of the CarboMedics and St. Jude Medical valves which contained titanium. The stainless wire suture material used to close the sternal incision was depicted as a signal void, and the areas of the signal loss were larger in the images taken by the field echo technique than those by the spin echo technique. The images taken by the spin echo technique in patients with atrial fibrillation had reduced quality due to the irregularity of repetition time. Cine MR imaging by the field echo technique showed physiological mitral regurgitant jets as signal loss within the flowing blood, which appeared as high signal intensity, bidirectionally in the bileaflet mechanical valve and unidirectionally in the monoleaflet mechanical valve. An abnormal cavity was seen behind the basal left ventricular myocardium in one patient with a CarboMedics valve. The wall of the abnormal cavity was disrupted abruptly and the rest of the wall consisted of pericardium and adjacent tissue in the image taken by the spin echo technique. The image taken by the field echo technique showed an abnormal jet flow from the basal part of the left ventricular cavity into the abnormal cavity, which was compatible with left ventricular pseudoaneurysm. Two-dimensional echocardiography and Doppler color flow mapping disclosed the abnormal cavity and the abnormal flow inside, but failed to show the connection between the left ventricle and the cavity due to reverberation of the ultrasound signal by the prosthetic valve. These findings suggest that MR imaging is a safe and promising method to assess the complications and valvular function in patients with a prosthetic carbon valve in the mitral position.

Aged↗
PubMed1997

[Surgical relief of airway obstruction from a double aortic arch associated with corrected transposition of the great arteries, pulmonary atresia and bilateral patent ductus arteriosus in a neonate].

A rare 20-day-old male with double aortic arch, corrected transposition of the great arteries (cTGA), pulmonary atresia and bilateral patent ductus arteriosus (PDA) was transported to our institute because of severe respiratory dysfunction and cyanosis. The patient had been already intubated and ventilated on respirator. A echocardiography and cine-angiography demonstrated that the both sides aortic arch had almost identical sizes, originating common carotid arteries and subclavian arteries and PDAs respectively, and the descending aorta located on the left side of the mid-line. At the first surgery, the distal of the right aortic arch was divided just proximal to the descending aorta after complete tissue dissection around the arch. The divided right sided aortic arch was mobilized from posterior to anterior aspect of the bronchus. Then the right subclavian artery was divided and an original Blalock-Taussig shunt was employed. The right sided PDA was ligated. After the first surgery, respiratory dysfunction lasted for weeks mainly because of the PGE1 dependent left sided PDA. At the second surgery, left sided modified Blalock-Taussig shunt was constructed and the left sided PDA was divided. These procedures resulted in stable respiratory status and oxygen saturation. The patient was extubated three days later and now in satisfactory clinical condition.

Abnormalities, Multiple↗
PubMed1997

[Surgical treatment of double outlet left ventricle].

Double outlet left ventricle (DOLV) is an uncommon congenital cardiac defect which was first reported by Sakakibara and associates. We studied anatomical aspects relevant to surgical repair in our 4 cases and additional 28 cases which had been reported on the literatures. The locations of ventricular septal defect (VSD) were subaortic in 20 cases, subpulmonary in 7, doubly-committed in 2 and unknown in 2. The positions of the aorta relative to the pulmonary artery were right or left anterior oblique in 11 cases, right or left side-by-side in 9, right or left posterior oblique in 10 and unknown in 3. The definitive surgery included Rastelli type operation in 18 cases, right ventricular outflow tract repair with closure of VSD in 6, intraventricular conduit repair in 4 and Fontan type operation in 4. In regard to the selection of the procedure, the size of right ventricle, the presence of pulmonary stenosis, the location of VSD and the relationship of the great arteries are very important. Although most of the patients underwent the Rastelli type operation, the right ventricular outflow tract reconstruction or intraventricular conduit repair could be adopted particularly in patients with posterior oblique position of the aorta relative to the pulmonary artery or subpulmonary VSD.

Adolescent↗
PubMed1997

[A case of modified Fontan operation with reconstruction of the nonconfluent pulmonary artery].

A three-year-old girl with complex cardiac anomalies and right isomerism successfully underwent a modified Fontan procedure and reconstruction of the nonconfluent pulmonary artery using autologous tissues. These cardiac anomalies included single right ventricle, atresia of the pulmonary trunk with nonconfluent pulmonary artery, atrial septal defect, common atrioventricular valve, bilateral PDAs, and bilateral SVCs. Preoperative cardiac catheterization showed elevated pulmonary artery pressure (mean pressure of 24 mmHg) and a small orifice of common pulmonary vein chamber. Pulmonary arteriographies showed balanced development of the branches. Indication for Fontan procedure was finally determined by measurement of the pulmonary artery and vein pressures and pulmonary vascular resistance before the cardiopulmonary bypass in the operation. Nonconfluent pulmonary artery was reconstructed by direct anastomosis of the right and left branches in the posterior aspect and enlarged with autologous pericardium patch. Intracardiac anomalies were repaired by enlargement of common pulmonary vein orifice (from 5 mm to 15 mm in diameter) and right atrial oblique partition. Furthermore, Fontan circulation was established by pulmonary artery angioplasty, direct anastomosis of left SVC to left pulmonary artery and direct anastomosis of right atrial appendage to pulmonary artery. Postoperative clinical course was uneventful, and cardiac catheterization showed mean right atrial pressure of 14 mmHg, cardiac index of 3.5 l/min/m2, and no pressure gradient at the site of reconstruction of the pulmonary artery.

Child, Preschool↗