Search PubMed⌕ Search

Biomedical subjects

H Iida

Publications and source records attributed to H Iida.

At least 235 records · Page 13Linked to original sources

Intercalary replacement of canine femora using a new bioactive bone cement.

We have developed a bioactive bone cement (BA cement) consisting of Bis-GMA resin and bioactive glass powder. It has high compressive and tensile strengths, a low curing temperature and its bioactivity allows it to bond directly with bone. We operated on the 18 femora of nine mongrel dogs for intercalary replacement of part of the bone by a metal prosthesis using either PMMA cement or BA cement for fixation. Three dogs were killed at each of 4, 12 and 26 weeks after surgery for the evaluation of fixation strength by a push-out test and for histological examination by Giemsa surface staining and SEM. Fixation strengths with PMMA cement at 4, 12 and 26 weeks after surgery were 46.8 +/- 18.9, 50.0 +/- 24.7, and 58.2 +/- 28.9 kgf (mean +/-sD), respectively. Those with BA cement were 56.8 +/- 26.1, 67.2 +/- 19.2, and 72.8 +/- 22.2 kgf, respectively. Fibrous tissue intervened between bone and PMMA cement but BA cement had bonded directly to bone at 12 and 26 weeks. This suggests that BA cement will be useful in providing long-lasting fixation of implants to bone under weight-bearing conditions.

Animals↗

[Immunocytochemistry with epitope tagging].

Epitope tagging is a useful method to investigate the cellular location of a tagged protein of interest. It also enables us to elucidate the size, abundance and posttranslational modification of the protein. I describe here the methods of them.

Animals↗

[Nicorandil, as ATP-sensitive K+ channel opener, potentiated morphine analgesia].

Recent reports demonstrated that K+ channels could contribute to signal transmission in the brain and spinal cord, and opioids' action may be related to K+ channels' functions. We investigated the antinociceptive effect of epidurally injected ATP-sensitive K+ channel opener, nicorandil, using tail flick test in rats. Epidural nicorandil (100 micrograms.rat-1) increased % maximum possible effect (%MPE) of epidural morphine (1, 10 micrograms.rat-1) from -3% to 40% (P < 0.05) and 46% to 65%, respectively. Epidural glibenclamide (10 micrograms.rat-1), ATP-sensitive K+ channel blocker, antagonized this effect. Epidural nicorandil alone (10 approximately 100 micrograms.rat-1) showed no antinociceptive effects. Systemic nicorandil (100 micrograms.rat-1, i.m.) did not increase the epidural morphine analgesia. These data suggest that the K+ channel opener could point the way to a new approach to pain treatment.

Adenosine Triphosphate↗

[Coronary artery bypass grafting under the beating heart in a patient with insufficient cardiopulmonary bypass].

Coronary artery bypass grafting in a 64-year-old male with a severe calcified ascending aorta was performed under the beating heart, because of insufficient cardiopulmonary bypass. The patient suffered inferior and anterolateral myocardial infarction with moderate mitral regurgitation. Computerized tomography showed a severely calcified ascending aorta. During the operation, cardiopulmonary bypass was conducted with femoral arterial cannulation and bicaval cannulation. Adequate perfusion flow, however, could not be achieved. Anastomoses of left internal thoracic artery-left anterior descending artery and right gastroepiploic artery-right coronary artery were performed under a beating heart supported by cardiopulmonary bypass. The patient made an uneventful recovery and postoperative angiography revealed patent grafts. Mitral regurgitation remained unchanged, but the postoperative lifestyle has been stable for the last 15 months.

Aortic Diseases↗

[Indication and result of hypothermic fibrillatory arrest in coronary artery bypass grafting].

Currently, cardioplegic arrest is used for almost all coronary artery bypass grafting (CABG). However, there are some cases in which aortic occlusion or the cardioplegic infusion is not desirable. In this paper, we discussed the indications and the usefulness of hypothermic fibrillatory arrest for CABG. From April 1992 to March 1995, CABG with hypothermic fibrillatory arrest was performed in 6 patients (3.9% of total CABG cases). The reasons of employing hypothermic ventricular fibrillation were as follows; calcified ascending aorta in 2 patients, coronary aneurysm associated with Behçet's decrease in 1, revascularization to the totally obstructed branches with poor left ventricular function in 2, and collateral circulation from bronchial artery with total obstruction of left main trunk in 1. The age range was 48 to 68 years with a mean of 59.0 +/- 7.8 years. Five patients had a history of myocardial infarction and 2 of them had a left ventricular ejection function less than 0.25. Surgical procedures consisted of elective ventricular fibrillation without aortic cross-clamp, systemic hypothermia and local pericardial cooling, left atrial or pulmonary artery venting, and local vessel isolation during distal anastomosis. Average number of grafts was 2.0 +/- 0.6, and 5 left internal thoracic arteries, 2 gastroepiploic arteries and 5 saphenous vein were used. Mean duration of ventricular fibrillation was 74.0 +/- 17.5 min. Postoperative angiography confirmed all bypasses patent. Only 1 patient, whose preoperative left ventricular ejection function was 0.20, died of heart failure 5 months after the operation. All other patients survived asymptomatically. Hypothermic fibrillatory arrest is useful and reliable technique in coronary artery bypass grafting when aortic occlusion or cardioplegic arrest is not desirable.

Aged↗

[Three cases of coronary to pulmonary arterial fistulae combined with valvular disease].

Three cases of coronary to pulmonary arterial fistulae (CAF) combined with valvular disease are reported. The first case was 53-year-old male admitted with mitral stenosis (MS) and left atrium thrombus. CAF originating from both coronary artery and draining to pulmonary artery were found by coronary angiography. Open mitral comissurotomy (OMC), thrombectory and ligation of CAF were performed. Case 2 was 52-year-old female suffered from CHF due to MS. Abnormal communication from left coronary artery to pulmonary artery was demonstrated. OMC and ligation of CAF were performed. Case 3 was 65-year-old male with combined valvular disease. MS, aortic regurgitation and CAF from right coronary artery to pulmonary artery were revealed. Mitral and aortic valve replacement and ligation of CAF were done. Diffusion of coronary angiography increase chance to reveal coronary artery fistulas during examination of acquired cardiac disease. Coronary artery fistulas draining into pulmonary artery were completely ligated by double ligation at both the arising point from coronary artery and the draining point to pulmonary trunk.

Aged↗

[Bone marrow transplantation versus maintenance chemotherapy for adult acute leukemia in first remission].

We compared the outcome of bone marrow transplantation (BMT) with that of maintenance chemotherapy for adults with acute leukemia who achieved first remission in Japanese Red Cross Nagoya First Hospital. From 1976 to 1993, 17 patients with acute myelogenous leukemia (AML) and 10 patients with acute lymphoblastic leukemia (ALL) received allogeneic BMT from HLA genotypically identical siblings in first remission, 4 patients with ALL undertook purged autologous BMT using monoclonal antibody and complement, and 55 patients with AML and 27 patients with ALL were treated with maintenance chemotherapy. The estimated 6-year disease free survival (DFS) of AML patients was significantly higher in the BMT group than in the chemotherapy group (77.3% vs 42.6%; p < 0.01). For ALL patients, the estimated 6-year DFS was 72.5% in the allo-BMT group and 100% for the auto-BMT group, but no patient was disease free more than 2 years in the chemotherapy group (p < 0.0001). We conclude that BMT after several courses of consolidation chemotherapy is the optimal treatment of choice in patients with AML and ALL in first remission. A prospective study is needed to confirm the efficacy of BMT after intensive consolidation chemotherapy.

Adolescent↗

Clinical analysis of malignant lymphomas of tonsils.

Data of 38 patients with primary tonsil lymphoma, treated during the past 14 years was analysed. All cases were non-Hodgkin lymphomas. There were 11 patients with Stage 1, 14 with Stage II, 8 with Stage III, and 4 with Stage IV tonsillar lymphomas. The applied chemotherapies were CHOP or MACOP-B regimen. The overall 5-year survival rate was 64.4%. Further analysis of the intermediate grade group showed that 5-year survival rates were 72.7%) for patients younger than 60 years old, in contrast to 35.0% for patients aged 60 or older (p 0.0049). Five-year survival rates were 100%) for Stage I, 32.4% for Stage II, 55.6% for Stage III, and 100%) for Stage IV patients (p = 0.0878). In patients with Stage II tonsillar lymphomas, 5-year survival rates were below 100% for CHOP regimen, 100% for MACOP-B regimen, 66.7% for radiation alone, and 0% for radiation followed by chemotherapy (p = 0.1966). In patients with Stage III tonsillar lymphomas, 5-year survival rates were below 100% for MACOP-B regimen, and 0% for initial radiation followed by chemotherapy (p = 0.2568). The factors influencing survival were age, stage, and treatment modality. For Stage I patients without bulky mass, radiation therapy is sufficient. For Stage II patients or Stage I patients with a bulky mass, CHOP regimen (followed by radiation) is the choice of treatment. For Stage III or IV patients,, MACOP-B regimen is promising.

Combined Modality Therapy↗

Cooperation of calcineurin and vacuolar H(+)-ATPase in intracellular Ca2+ homeostasis of yeast cells.

Saccharomyces cerevisiae VMA genes, encoding essential components for the expression of vacuolar membrane H(+)-ATPase activity, are involved in intracellular ionic homeostasis and vacuolar biogenesis. We report here that the immunosuppressants FK506 and cyclosporin A cause general growth inhibition of the vma3 mutant. Upon addition of the drugs, the mutant grew neither in the presence of more than 5 mM Ca2+ nor above pH 6.0. The action of the immunosuppressants is dependent on their binding proteins and ascribable to inhibition of calcineurin activity; a mutation of a calcineurin subunit (cnb1) shows synthetic lethal interaction with the vma mutation. The addition of FK506 decreases the cytosolic free concentration of Ca2+ in the vma3 mutant cells. Consequently, FK506 induces an 8.9-fold elevation of a nonexchangeable Ca2+ pool. These results suggest that calcineurin controls calcium homeostasis by repression of Ca2+ flux into a cellular compartment(s) and that the vacuolar H(+)-ATPase is essential for cell growth cooperating with calcineurin to regulate the cytosolic free concentration of Ca2+.

Base Sequence↗

Purification and characterization of recombinant human cathepsin E.

The human cathepsin E was purified from the culture supernatant of Pichia pastoris strain transformed with a human cathepsin E expression plasmid. Purification was performed by a three-step procedure, TSKgel Phenyl-5PW, Toyopearl HW55S and TSKgel DEAE-5PW column chromatographies. The purified recombinant cathepsin E had the molecular mass of around 82-kDa with the amino-terminal sequence started with Ile37 of the predicted amino acid sequence, suggesting the human cathepsin E was accumulated in the culture suparnatant as the mature dimer enzyme. The result of endoglycosidase-H digestion followed by Western blot analysis of the purified recombinant cathepsin E suggested that the human cathepsin E expressed in Pichia pastoris received N-linked high-mannose type glycosylation.

Cathepsin E↗

Calmodulin-dependent protein kinase II and calmodulin are required for induced thermotolerance in Saccharomyces cerevisiae.

We show here that yeast mutants lacking calmodulin-dependent protein kinase II fail to fully acquire induced thermotolerance. A similar result was also obtained with mutants depending solely on either the N-terminal half or the C-terminal half of calmodulin. These findings indicate that both calmodulin-dependent protein kinase II and calmodulin are required for induced thermotolerance.

Calcium↗

Error analysis of table look-up method for cerebral blood flow measurement by 123I-IMP brain SPECT: comparison with conventional microsphere model method.

While N-isopropyl-p-[123I]iodoamphetamine (IMP) is commonly used as a flow tracer, significant clearance from the brain causes underestimation of CBF as compared with true CBF when conventional microsphere model analysis is applied. We previously reported a simple "table look-up" method for CBF measurement using IMP taking into account this clearance effect. The method is based on a two-compartment model, the K1 (corresponding to CBF) and k2 constants being obtained from a table from the ratio of the 1st SPECT (40 min) to the 2nd SPECT (180 min) counts. Arterial input data used were obtained by one point blood sampling 10 min after IMP infusion against the standard input function. In the present study, this approach was compared with conventional microsphere model analysis. For 30 subjects, the latter method entailed 8 min continuous arterial blood sampling after IMP infusion and the use of SPECT data at the end of this period, calibrated by a count ratio of 8 min/40 min planar images of whole brains. A good correlation was observed between the two methods (r = 0.88), but an overestimation of table look-up method CBF as compared with microsphere model CBF was observed contrary to theoretical predictions. Limitations in the estimation of SPECT data at 8 min, obtained with SPECT data at 40 min for calibration of the count ratio of 8 min/40 min whole brain planar images, might be responsible for this.

Amphetamines↗

Regional cerebral blood flow, blood volume, oxygen extraction fraction, and oxygen utilization rate in normal volunteers measured by the autoradiographic technique and the single breath inhalation method.

By means of a high resolution PET scanner, the regional cerebral blood flow (rCBF), cerebral blood volume (rCBV), oxygen extraction fraction (rOEF), and metabolic rate of oxygen (rCMRO2) for major cerebral gyri and deep brain structures were studied in eleven normal volunteers during an eye-covered and ear-unplugged resting condition. Regional CBF was measured by the autoradiographic method after intravenous administration of H2(15)O. Regional OEF and rCMRO2 were measured by the single inhalation of 15O2. With MR T1-weighted images as an anatomical reference, thirteen major cerebral gyri, caudate nucleus, lentiform nucleus, thalamus, midbrain, pons, cerebellum and vermis were defined on the CMRO2 images. Values were read by using circular regions of interest 16 mm in diameter. The posterior part of the cingulate gyri had the highest rCBF and rCMRO2 values among brain structures, followed by the lentiform nucleus, the cerebellum, the caudate nucleus, and the thalamus. Parahippocampal gyri had the lowest rCBF and rCMRO2 values among the cortical gyri. Regional OEF for the pontine nuclei (0.34 +/- 0.04), the midbrain (0.35 +/- 0.05), the parahippocampal gyri (0.35 +/- 0.04 for the right and 0.37 +/- 0.05 for the left), and the thalami (0.37 +/- 0.05 for the right and 0.36 +/- 0.04 for the left) were significantly lower than the mean OEF for the cerebral cortices (0.42 +/- 0.04) (p < 0.05 or less). The global CBF and CMRO2 were consistent with those obtained by the Kety-Schmidt method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Clinical assessment of squamous cell carcinoma of the nasal cavity proper.

The subjects were 14 patients with squamous cell carcinoma or undifferentiated carcinoma of the nasal cavity treated at Nihon University Hospital between October 1984 and November 1991, who were followed for at least 3 years. The site of the tumor origin within the nasal cavity was the lateral wall in 8 patients, the nasal septum in three patients, and unknown in three patients. Histologically, there were 13 squamous cell carcinomas in (3 well differentiated, 7 moderately differentiated, and 3 poorly differentiated) and 1 undifferentiated carcinoma. Treatment was by a combination of radiotherapy, chemotherapy, and surgery in 8 cases, a combination of radiotherapy and surgery in 5 cases, and surgery alone in 1 case. The 3-year and 5-year Kaplan-Meier survival rates were 86 and 69%, respectively. A total of 6 patients suffered a recurrence, with local recurrence occurring in 4 patients and pulmonary metastasis in 2 patients. Tumor control was achieved in 3 of the 4 cases of local recurrence by reoperation, and by surgery in 1 of the 2 cases of pulmonary metastasis. The duration of the recurrence-free interval in the patients who developed local recurrences, 18 to 46 months after the completion of the initial course of therapy, was of considerable interest.

Carcinoma, Squamous Cell↗

Photic stimulation study of changing the arterial partial pressure level of carbon dioxide.

To investigate the effect of the level of baseline cerebral blood flow (CBF) on local CBF augmentation by activation, we have used positron emission tomography to measure regional CBF (rCBF) in 12 normal volunteers with and without photic stimulation during hypocapnia, normocapnia, and hypercapnia. The increase in rCBF in the primary visual cortex by photic stimulation was 10.8 +/- 3.1, 18.6 +/- 9.3, and 19.5 +/- 6.1 ml 100 ml-1 min-1 in hypo-, normo-, and hypercapnia, respectively. The increase was significantly smaller in hypocapnia than in normocapnia (p < 0.005). The fractional CBF increase caused by the photic stimulation was the same in all breathing conditions. This result indicates that the magnitude of the CBF increase induced by neuronal activity correlates proportionally with the level of baseline CBF.

Adult↗