Biomedical subjects

Y Iida

Publications and source records attributed to Y Iida.

At least 55 records · Page 3Linked to original sources

PubMed2000

[MVP for MR associated with extensive calcification of the mitral valve annulus].

We experienced two surgical cases of MR associated with extensive calcification of the mitral valve annulus. For two cases we performed MVP which consisted of valve repair and annular remodeling. Annular remodeling was performed only on the annulus without calcification using 3 mm Gore-tex graft, because calcified annulus did not contribute to annular dilatation and would not dilate in the future. Both patients recovered uneventfully. Postoperative echocardiography revealed no MR in both cases.

Aged↗

PubMed2000

Dexa-measured bone density changes over time after intertrochanteric hip fractures.

The local bone density after an intertrochanteric hip fracture changes over time. In this study, bone density was measured in proximal femur and third lumbar vertebrae in patients treated for an intertrochanteric hip fracture at various periods. There were 60 patients (mean age 71.4 years) and 50 control patients (mean age 62.4 years). Bone density measurements were performed with Dual energy X-ray absorptiometry (DEXA). Bilateral measurements of the greater trochanter, lesser trochanter and femoral diaphysis as well as the third lumbar vertebrae were performed. Each area showed different course of change. The bone density of the greater trochanter and the lesser trochanter in the injured side increased after three months as compared with the control. After three years, the bone density of the greater trochanter decreased. The bone density of the femoral diaphysis and the third vertebrae gradually decreased over time. The authors suggest that bone density changes under the influence of callus formation, bone remodeling, decrease in daily activity, and use of ambulatory aids, etc.

Absorptiometry, Photon↗

PubMed1999

Saccular descending thoracic aortic aneurysm with dysphagia.

A 76 year old woman had suffered from chest pain, back pain, and dysphagia for 8 months. She was diagnosed as having a thoracic aortic aneurysm by chest X-ray and chest enhanced computed tomography. Simultaneously, severe dysphagia developed. Chest enhanced computed tomography and chest aortic aortography at our hospital demonstrated a saccular descending thoracic aortic aneurysm. Esophagography demonstrated that the esophagus was compressed by the aneurysm; therefore, a graft replacement for the saccular descending thoracic aortic aneurysm was performed on February 17th, 1998. A left sided 6th intercostal approach was made, and graft replacement for the aneurysm using a 22 mm Hemashield prosthetic graft was performed under temporary bypass from the thoracic aorta just distal to the left subclavian artery and to the left femoral artery. The postoperative course was uneventful, the severe dysphagia improved dramatically, but a pleural effusion of 1000 ml collected 3 weeks after the operation. Surgical cases of saccular descending thoracic aortic aneurysm with dysphagia are rare, and with this in mind, we report this case to the the medical literature.

Aged↗

PubMed1999

Detection of antifungal activity in Anemarrhena asphodeloides by sensitive BCT method and isolation of its active compound.

Antifungal activity was detected from Anemarrhena asphodeloides by the Bio-Cell Tracer (BCT) method. An active fraction was separated by silica gel column chromatography and reverse-phase HPLC. The molecular weight was determined by GC-MS, and the molecular structure was analyzed by IR, (1)H NMR, and (13)C NMR. The isolated compound was found to be identical to nyasol, (Z)-1, 3-bis(4-hydroxyphenyl)-1,4-pentadiene, which formerly appeared in the literature without any remark on the antifungal activity. This compound showed antimicrobial activity against 38 strains of fungi and five strains of bacteria. The minimum inhibitory concentration (MIC) ranged from 12.5 to 200 microg mL(-)(1), except for two strains based on the broth dilution method.

Antifungal Agents↗

PubMed1999

Konjac mannan improves the vitamin B-6 status of rats fed a vitamin B-6-deficient diet.

To investigate how dietary fiber in the diet affects vitamin B-6 nutriture of rats which have been deprived of vitamin B-6, rats were made vitamin B-6-deficient by feeding a vitamin B-6-deficient 70% casein diet. They were fed 2% cellulose powder-based vitamin B-6-deficient diets supplemented with 3% of additional dietary fiber sources (agar, konjac mannan, pectin and cellulose powder) for subsequent 18 days. Vitamin B-6 status was evaluated according to several biological criteria (weight gain, urinary excretion of xanthurenic acid after tryptophan loading, plasma pyridoxal 5'-phosphate, apparent pyridoxal 5'-phosphate-saturation of liver kynureninase, urinary excretion of 4-pyridoxic acid and fecal output of vitamin B-6). Vitamin B-6 status evaluated by these criteria was considerably improved in the konjac mannan-fed group, when compared with the respective data of the vitamin B-6 supplemented group. The relative mean effect of the konjac mannan diet was about 40% of the vitamin B-6 supplemented diet. In conclusion, konjac mannan was effective for improving the vitamin B-6 nutritional state in vitamin B-6-deprived rats.

Animals↗

PubMed1999

The effects of N(G)-nitro-L-arginine-methyl ester on neurologic and histopathologic outcome after transient spinal cord ischemia in rabbits.

UNLABELLED: Little is known about the role of nitric oxide in the pathophysiology of spinal cord ischemia. We evaluated the effects of nitric oxide synthase (NOS) inhibition by N(G)-nitro-L-arginine-methyl ester (L-NAME) in rabbits whose abdominal aorta was occluded for 20 min (Experiment 1) or 25 min (Experiment 2). In Experiment 1, the L-NAME group (n = 6) received 3 mg/kg i.v. L-NAME, followed by an i.v. infusion of 3 mg x kg(-1). h(-1) until 6 h after reperfusion. Ischemia was induced 20 min after the start of L-NAME. The phenylephrine group (n = 6) received phenylephrine to maintain comparable blood pressure. The control group (n = 6) received saline. In Experiment 2, L-NAME (3 mg/kg i.v. L-NAME, followed by an i.v. infusion of 3 mg x kg(-1). h(-1) until 6 h after reperfusion) and phenylephrine groups (n = 6 each) were studied. Ischemia was induced 100 min after the start of L-NAME. Forty-eight hours after reperfusion, hindlimb motor function and histopathology of the spinal cord were examined. In Experiment 1, L-NAME and phenylephrine both improved neurologic outcome, with higher intraischemic blood pressures than saline. In Experiment 2, L-NAME worsened the neurologic and histopathologic outcome compared with phenylephrine. Attenuation of damage by L-NAME in Experiment 1 may be attributable to an intraischemic blood pressure increase. The worse outcome with L-NAME in Experiment 2 suggests that NOS inhibition exacerbates ischemic spinal cord damage. IMPLICATIONS: Nonselective inhibition of nitric oxide synthase activity has aggravating effects on the neurologic and histopathologic outcome after transient spinal cord ischemia.

Animals↗

PubMed1999

Radioimmunotherapy for liver micrometastases in mice: pharmacokinetics, dose estimation, and long-term effect.

The pharmacokinetics of a therapeutic dose of 131I-labeled antibody and the absorbed dose in liver micrometastases of human colon cancer LS174T in female BALB/c nu/nu mice were investigated, along with the long-term therapeutic effect. Mice with liver micrometastases were given an intravenous injection of 131I-labeled anti-carcinoembryonic antigen (CEA) antibody F33-104 (8.88 MBq/ 40 microg). The biodistribution of the antibody was determined 1, 2, 4, 6, and 10 days later. The absorbed dose was estimated for three hypothetical tumor diameters; 1,000, 500, and 300 microm. Autoradiography showed a homogeneous distribution of radioactivity in the micrometastases, and a high uptake was maintained until day 6 (24.0 % injected dose (ID)/g on day 1 to 17.8 %ID/g on day 6), but decreased thereafter. The absorbed doses in the 1,000-, 500-, and 300-microm tumors were calculated to be 19.1, 12.0, and 8.2 Gy, respectively. The intravenous injection of the 131I-labeled antibody also showed a dose-dependent therapeutic effect (all mice of the nontreated group died, with a mean survival period of 4 weeks; 3 of the 8 mice that received 9.25 MBq survived up to 120 days with no sign of liver metastasis). These data give further evidence that micrometastasis is a good target of radioimmunotherapy, and that an absorbed dose of less than 20 Gy can effectively control small metastatic lesions.

Animals↗

PubMed1999

Adventitia-dependent relaxations of canine basilar arteries transduced with recombinant eNOS gene.

We recently reported that expression of recombinant endothelial nitric oxide (NO) synthase (eNOS) gene in adventitial fibroblasts restores NO formation in canine cerebral arteries without endothelium in response to bradykinin ex vivo and in vivo. The present study was designed to further characterize the stimuli that can activate recombinant eNOS enzyme expressed in the adventitia of cerebral arteries. To stimulate recombinant eNOS, we used serum (0. 1-10%), substance P (10(-11)-3 x 10(-9) M), and ANG II (10(-7)-10(-5) M) because they increase intracellular calcium concentrations in fibroblasts. Endothelium-denuded segments of canine basilar arteries were incubated with an adenoviral vector encoding beta-galactosidase gene or eNOS gene for 30 min at 37 degrees C. After 24 h, vasomotor activity and cGMP formation in eNOS or beta-galactosidase arteries were examined by isometric force recording and by radioimmunoassay, respectively. In control arteries and beta-galactosidase gene-transduced arteries, serum caused concentration-dependent contractions, whereas in recombinant eNOS gene-transduced arteries, serum produced concentration-dependent relaxations. Substance P and ANG II had no effect on vascular tone in control and beta-galactosidase arteries but caused concentration-dependent relaxations as well as a significant increase in cGMP levels in eNOS arteries. These relaxations were blocked by the NOS inhibitor NG-nitro-L-arginine methyl ester. Chemical treatment or mechanical inactivation of adventitial function significantly attenuated substance P-induced relaxations and ANG II-induced relaxations. These findings demonstrate that serum, substance P, and ANG II cause adventitia-dependent relaxations in cerebral arteries expressing the recombinant eNOS gene. This mechanism of vasodilatation may have beneficial effects in the prevention and treatment of vascular disorders characterized by the diminished bioavailability of NO, such as cerebral vasospasm.

Angiotensin II↗

PubMed1999

Characteristics of intracardiac potentials at successful ablation sites in concealed Wolff-Parkinson-White syndrome.

The authors investigated bipolar electrograms recorded from the catheter tip at the actual successful ablation sites in 22 consecutive patients with concealed Wolff-Parkinson-White syndrome to clarify the characteristics of the potentials indicating the optimal site for catheter ablation. In all patients the retrograde transaortic approach to their left-sided accessory pathways, and a temperature-controlled (60 degrees C) energy delivery, were performed. The authors assumed that a shorter dissociation time (time from energy delivery to ventriculoatrial conduction dissociation) indicated more accurate catheter mapping. A significant negative correlation (r = 0.527, p < 0.05) between the AV ratio (ratio of the amplitudes of the atrial to ventricular potentials) recorded at the ablation catheter tip and the dissociation time was observed. When the AV ratio and the dissociation time were compared among the groups classified according to the corresponding Npeak (the number of positive potential peaks in the electrogram obtained from the ablation catheter tip during right ventricular apical pacing) value, they differed significantly (p < 0.05 and p < 0.01, respectively), ie, a higher AV ratio and a shorter dissociation time related to a multipeak electrogram from the ablation catheter tip. The authors conclude that the atrial insertion site of the accessory pathway, exhibiting a multipeak complex electrogram that may represent nonuniform anisotropic characteristics, is an adequate ablation site.

Action Potentials↗

PubMed1999

[Sensitive screening of antifungal compounds from acetone extracts of medicinal plants with a Bio-Cell Tracer].

Antifungal activity of medicinal plants against Aspergillus niger was evaluated using Bio-Cell Tracer (BCT). By this system enabled the real time determination of hyphal growth rate could be done in the presence or absence of Chinese herbal extracts. Of the 41 herbal extracts with 60% acetone extracts tested by the present method, 26 were found to contain active components against A. niger hyphal growth. In contrast, by conventional methods, no active component was detected from every herbal extract except 3 herbal extracts. From the extract of Anemarrhena asphodeloides, one of active components was isolated and its structure determined by NMR, UV, and mass spectroscopy. The compound was identified as broussonin A (2-3-(4-hydroxyphenyl)propyl)-5-methoxy-phenol) which was formerly reported as a phytoalexin of Broussonetia papyrifera Vent.

Acetone↗

PubMed1999

Alteration of hepatic sulfation by endotoxin.

Administration of an endotoxin, lipopolysaccharide (1 mg/kg body weight), caused decreases in hepatic sulfations of xenobiotics in male rats through changes in the amounts of at least three forms of sulfotransferases, ST1A1, ST1B1 and ST1C1. The time-dependent decrease was first observed with ST1B1, followed by ST1A1 and ST1C1; and the decrease was more profound in the levels of mRNAs than those of proteins. The decreases in their mRNAs were, however, prevented by the pretreatment with dexamethasone. These results suggest that the endotoxin suppresses the hepatic sulfation through a cytokine-mediated mechanism to change individually hepatic levels of ST1A1, ST1B1 and ST1C1.

Animals↗

PubMed1999

Intratumoral distribution of radiolabeled antibody and radioimmunotherapy in experimental liver metastases model of nude mouse.

UNLABELLED: The biodistribution and intratumoral distribution of radiolabeled anticarcinoembryonic antigen (CEA) monoclonal antibody in experimental liver metastases and the therapeutic effect of 131I-labeled anti-CEA antibody on the metastases were studied. METHODS: Three weeks after an intrasplenic injection of human colon cancer cells, mice received an intravenous injection of 125I- or 111In-labeled anti-CEA antibody F33-104. The biodistribution and tumor penetration of radiolabeled antibody were examined by using quantitative autoradiography. To evaluate the therapeutic effect, 5.55, 9.25 or 11.1 MBq (150, 250 or 300 microCi) 131I-labeled F33-104 were injected into groups of mice that had micrometastases smaller than 1 mm. Control groups were injected with phosphate-buffered saline or 131I-labeled control antibody. Mice were killed 3 wk later to determine the size of liver metastases. RESULTS: 1251-labeled F33-104 showed a high accumulation in the liver metastases (percentage of injected dose per gram of metastases [%ID/g] >24%, metastasis-to-liver ratio >9.8, metastasis-to-blood ratio >2.1); however, its accumulation was heterogeneous or peripheral in the nodules more than 1 mm in diameter. When the antibody dose was increased, antibody penetration was improved, but tumor uptake of radioactivity and specificity ratios decreased. In mice with large metastases, radioactivity in the normal tissue was lower than that in mice with small metastases, resulting in higher metastasis-to-background ratios. 111In-labeled antibody showed even higher tumor uptake than 125I-labeled antibody (>51 %ID/g). Metastases formation was suppressed in a dose-dependent manner by 131I-labeled F33-104 injection (5 of 8 mice had no macroscopic tumor after an injection of 5.55 MBq (150 microCi), and all mice had no visible metastasis after an injection of 9.25 or 11.1 MBq [250 or 300 microCi]), whereas tumor progression was seen in the control groups. CONCLUSION: Liver metastases had easy accessibility to the antibody. Micrometastases of less than 0.5 mm in diameter showed homogeneous intratumoral distribution of injected antibody and were successfully treated with 131I-labeled antibody. Very high uptake and satisfactory metastasis-to-liver ratios with 111In-labeled antibody suggest that the use of a radiometal with high beta-energy, such as 90Y or 188Re, is preferable for the successful radioimmunotherapy of metastases larger than 1 mm.

Animals↗

PubMed1999

[Surgical repair for ischemic mitral regurgitation: a method of mitral valve plasty with evaluation of morphological changes of mitral valve].

We evaluated a method of mitral valve plasty (MVP) for ischemic mitral regurgitation (IMR) by examining the morphological changes of the mitral valve. From November 1992 to May 1998, 8 patients (M : F = 4/4, age 44-79 years, mean age 65.1 years) with IMR underwent surgical repair. Preoperative mitral regurgitation (MR) was grade III of Sellers classification in 7 patients and grade IV in 1 patient. The cause of MR was mitral valve annular dilatation in 4 patients, mitral valve prolapse due to papillary muscle elongation in 2 patients, and partial papillary muscle rupture (PMR) in 2 patients. Cardiac surgery consisted of CABG + MVP in 7 patients and MVP in 1 patient. Mitral valve repair was separated into three types. Repair for annular dilatation consisted of commissuroplasty in 3 patients (2 patients Kay method, 1 patient Reed method) and ring annuloplasty using a Carpentier-Edwards ring (C-E ring) in 1 patient. Repair for papillary muscle elongation consisted of papillary muscle shortening and ring annuloplasty using a C-E ring. Repair for partial PMR consisted of papillary muscle implantation and ring annuloplasty for anterior leaflet prolapse in 1 patient, and quadrangular resection, posterior leaflet plasty (McGoon method) and ring annuloplasty in 1 patient. There was no hospital death. Postoperative outcome was 6 patients with no MR and 2 patients with grade II MR, but they were well-controlled with medication. Based on the morphological changes of the mitral valve, it is considered that MVP for IMR is an effective and recommended procedure.

Adult↗

PubMed1999

Quantification analysis of splice signal sequences: mutation of 3'-splice signal sequence and mechanism of unsplicing in a beta-thalassemia pre-mRNA.

Strength of splice signal sequence plays an important role in mammalian pre-mRNA splicings. In the splicing of human beta-globin thalassemia pre-mRNA, a 25-nucleotide deletion covering the signal sequence at 3'-splice site of intron 1 causes unsplicing of intron 1, while splicing of intron 2 occurs normally. This gives abnormal mRNA and beta-thalassemia disease. If 3'-splice site of intron 1 is inactivated, two 5'-splice signals of introns 1 and 2 compete with each other for the 3'-splice site of intron 2. Our quantification analysis revealed that the 5'-splice signal of intron 2 is stronger than that of intron 1, explaining the mechanism for unsplicing of intron 1.

3' Untranslated Regions↗

PubMed1998

Cimetidine reduces impairment of cellular immunity after cardiac operations with cardiopulmonary bypass.

OBJECTIVE: Depressive effects of cardiopulmonary bypass on cell-mediated immune responses may lead to postoperative infectious complications. We previously reported that cimetidine reduced postbypass depression of the cytotoxic activity of natural killer cells. This study evaluated cimetidine as an agent to preserve cellular immunity after cardiac operations. METHODS: In a prospective randomized study, 20 patients were divided into two groups of equal size. Cimetidine-group patients received 400 mg of cimetidine intravenously before bypass and a 33 mg/hr intravenous infusion of cimetidine after the operation, continuing until the fifth postoperative day. Control-group patients received conventional perioperative therapy. Lymphocyte subsets, natural killer cell activity, percentage of CD56+CD16+ (percentage of natural killer cells), and percentage of CD11b+CD8+ (percentage of suppressor T lymphocytes) were measured perioperatively. RESULTS: Although temporary postoperative reductions in percentages of CD3+, CD4+, and CD56+CD16+ cells were observed in both groups, CD8+ percentages on postoperative day 1 and CD11b+CD8+ percentages on postoperative days 1 and 3 in the cimetidine group were significantly lower compared with those in the control group (p = 0.01,p = 0.004, andp = 0.02, respectively). Temporary postoperative reduction of natural killer cell activity was also observed in both groups, but the natural killer cell activity on postoperative day 1 in the cimetidine group (17.1%) was significantly higher (p = 0.02) than that in the control group (8.20%). CONCLUSIONS: Cimetidine counteracts depressive effects of cardiopulmonary bypass on cell-mediated immunity and may possibly reduce postoperative susceptibility to infection.

Antigens, CD↗

PubMed1998

Functional quantitative analysis of the genome in cultured human mesangial cells. Technical note.

For normal physiological function, each cell tightly regulates gene expression in a specific fashion so that critical proteins are synthesized in a well-coordinated manner. Therefore, it is very important to uncover which genes are expressed in specific cells. Recent technological advances combined with rapid large-scale DNA sequencing and computerized data processing have allowed us to investigate the expression levels of a variety of transcripts in the mesangial cells, a target of injury in many forms of glomerulonephritis. Utilizing a large scale sequencing of a 3'-directed cDNA library, which allows us to avoid variable cloning efficiencies reflecting the size of cDNA, we investigated expression profiles of various molecules in cultured human mesangial cells. Among the 1,193 sequenced clones, 688 (57.7%) appeared more than once (redundant sequence group), representing 203 different species. Thirty-nine of these appeared more than three times. The most abundant mRNA was that of fibronectin, which consisted of 3.9% of the total mRNA population. Except for mitochondrial or ribosomal genes, calcyclin came next (2.5%), followed by two cytoskeletal genes, gamma-actin gene and calpactin 1 light chain gene, in addition to an amyloid precursor protein homolog (0.7%). In conclusion, we performed a molecular biological quantification of transcripts in mesangial cells. Fibronectin was the most abundantly expressed, followed by calcyclin, gamma-actin, calpactin 1 light chain, and an amyloid precursor protein homolog. We also discovered some candidate genes specific for human mesangial cells. The expression profile of the transcripts serves as an important tool in understanding the biological properties of mesangial cells.

Actins↗

PubMed1998

Diagnostic value of technetium-99m methoxyisobutyl isonitrile (99mTc-MIBI) scintigraphy in detecting thyroid cancer metastases: a critical evaluation.

Technetium-99m methoxyisobutyl isonitrile (99mTc-MIBI) scintigraphy has recently been used in clinical application for detecting thyroid cancer metastases, its role being considered supplementary to serum thyroglobulin (Tg) measurements and radioactive iodine (131I) whole-body scans (WBS). The present retrospective study was designed to elucidate the role of 99mTc-MIBI scans in localizing metastatic lesions by assessing sensitivity and specificity of the scan results obtained in a group of 68 thyroidectomized thyroid cancer patients. Presence or absence of thyroid cancer was judged with other diagnostic modes including serum Tg measurements, 131I WBS, bone scans, chest x-rays, computed tomography (CT), ultrasonography, histopathology, and evolution of disease during follow-up. All scans were read on lesion basis for detecting neck, lung, and bone metastases and also on region basis, namely head-neck, chest, and abdomen-pelvis-extremities (ab-p-ex) areas. The sensitivity of detection was 94.4% (17/18) for neck, 78.4% (40/51) for lung, and 92.8% (64/69) for skeletal lesions. Positive predictive value (PPV) and negative predictive value (NPV) were 96.3% (26/27) and 97.7% (43/44) for head-neck; 94.7% (71/75) and 50.0% (12/24) for chest; 100.0% (25/25) and 93.1% (54/58) for ab-p-ex regions, respectively. For all scan sites taken together, PPV and NPV were 96.1% (122/127) and 86.5% (109/126), respectively. In conclusion, the present study reveals that 99mTc-MIBI can be proposed as a first-line diagnostic agent for the follow-up protocol of thyroid cancer patients, although the ability to detect small lung metastases is somewhat limited.

Adult↗

PubMed1998

[A case of idiopathic intussusception of the stomach].

A 73-year-old man was admitted to our hospital because of vomiting. A fist-sized tumor with tenderness was palpated on his epigastric region. Fluoroscopic examination of the stomach showed narrow body and dilated antrum with intussusception. Endoscopic findings revealed fold convergence to the antrum. Intraoperatively, the body of the stomach was invaginated into the antrum with hepatoduodenal ligament. It was difficult to repair or resect, and a gastrojejunostomy was performed. On the 10th operative day, fluoroscopic examination of the stomach showed no intussusception of the stomach and no lesion in the upper gastrointestinal tract. To our knowledge, such cases of idiopathic intussusception of the stomach are rare.

Aged↗