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Biomedical subjects

T Kido

Publications and source records attributed to T Kido.

At least 37 records · Page 2Linked to original sources
PubMed2001

Development status of Terumo implantable left ventricular assist system.

We have been developing an implantable left ventricular assist system (T-ILVAS) featuring a magnetically suspended centrifugal pump (MSCP) since 1995. In vitro and in vivo studies using a prototype MSCP composed of a polycarbonate housing and impeller (196 ml) have demonstrated long-term durability and excellent blood compatibility for up to 864 days, and excellent stability of the magnetic bearing of the MSCP. These preliminary results strongly suggested that the magnetic bearing of the MSCP is reliable and is a most feasible mechanism for a long-term circulatory assist device. We have recently devised a clinical version pump made of titanium (180 ml) with a new position sensor mechanism and a wearable controller with batteries. Cadaver fit study confirmed that the Type IV pump could be implanted in a small patient with a body surface area as small as 1.3. The in vitro performance tests of the Type IV pump demonstrated excellent hydrodynamic performances with an acceptable hemolysis rate. New position sensors for the titanium housing showed more uniform sensor outputs of a magnetic bearing than in the prototype polycarbonate pump. The Type IV pump then was evaluated in vivo in 6 sheep at the Oxford Heart Centre. Four sheep were electively sacrificed at 3 months and were allowed to survive for more than 6 months for long-term evaluation. In this particular series of experiments, no anticoagulant/antiplatelet regimen was utilized except for a bolus dose of heparin during surgery. There was a left ventricular mural thrombi around the inflow cannula in 1 sheep. Otherwise, there was no mechanical failure nor sign of thromboembolism throughout the study.

Animals↗
PubMed2001

Application of path analysis to urinary findings of cadmium-induced renal dysfunction.

In order to identify some causal relations among various urinary indices of cadmium-induced renal dysfunction, such as glucose, total protein, amino nitrogen, beta 2-microglobulin (beta 2-m), metallothionein (MT), and cadmium (Cd), we applied path analysis method to previous epidemiological studies targeting the residents of the Cd-polluted Kakehashi River basin of Ishikawa Prefecture, Japan. We obtained a diagram-termed path model, representing some causal relations among the above urinary indices. It shows that urinary Cd is located at the beginning point in the diagram, and Cd-induced renal dysfunction develops in the following order: Cd exposure-->increase of beta 2-m and/or MT excretion-->increase of amino-N and/or total protein excretion-->increase of glucose excretion. It was proved mathematically, that in the case of both males and females, increased excretions of beta 2-m and/or MT were the most sensitive urinary indices of the early stage of chronic Cd-induced renal dysfunction.

Aged↗
PubMed2001

Effects of San'o-shashin-to and the constituent herbal medicines on theophylline-induced increase in arterial blood pressure of rats.

San'o-shashin-to, composed of Scutellariae Radix, Coptidis Rhizoma and Rhei Rhizoma (volume ratio = 1:1:1), reduced an increase in arterial blood pressure of anesthetized rats induced by theophylline (5 mg/kg, i.v.). The hypotensive effect of San'o-shashin-to was produced in a dose dependent manner and was maximum at its 0.5 g/kg. Then the constituent herbal medicines were examined for their possible hypotensive effect. Scutellariae Radix of 0.2 g/kg slightly decreased in the blood presure. Rhei Rhizoma of 0.2 g/kg decreased in the blood pressure and the hypotensive effect was significantly produced even at the dose of 0.05 g/kg, while Coptidis Rhizoma had little effect. Among fractions of San'o-shashin-to separated by Diaion HP-20 column chromatography, the 50% methanol-eluted fraction had a large hypotensive effect. The 50% methanol-eluted fraction of Scutellariae Radix and Rhei Rhizoma were also effective and, especially, that of Rhei Rhizoma had a large hypotensive effect. In isometric tension study, Scutellariae Radix and Rhei Rhizoma (10-30 microg/ml) slightly exerted contractile and relaxant effects, respectively, on the phenylephrine-contracted endothelium-intact rat thoracic aorta. Coptidis Rhizoma (1-10 microg/ml) caused both endothelium-dependent and -independent relaxantion. These results suggest that the hypotensive effect of San'o-shashin-to is not mediated by the direct action on blood vessel but by other actions. Some components in Scutellariae Radix and Rhei Rhizoma, especially in the latter may play a main role in the hypotensive effect.

Animals↗
PubMed2001

[Special categories of elderly patients with intractable neurological diseases (NANBYO) in Toyama, Japan].

The purpose of this study was to elucidate special categories of elderly patients with intractable neurological diseases (NANBYO) in Toyama, Japan. This goal was accomplished through comparisons of data gathered in 1991 and 1997. Forty-eight (20 males, 28 females) with such diseases were recruited for the study and agreed to be interviewed. The surveys were performed by three public health center nurses. The same questionnaire was used in both years. The surveys show that the number of jobless patients and those who needed total support increased by approximately 20% from 1991 to 1997. In addition, it appears that the ratio of hospitalized patients and those who needed medical equipment installed at home increased considerably. The number of patients with caregivers increased by approximately 30%. As the caregivers got older, it was observed that the patients became more anxious about their health condition. Also, in both years, both patients and caregivers showed the highest concern about a sudden change in the patients' conditions. In conclusion, an assessment of patient and family needs is important for the development of a community health care system. It is also essential for all the parties in the field of health, medicine, and welfare, as well as volunteer groups, to have a good understanding of each other's services and to have a cooperative relationship coordinated by health centers through discussion of each individual case.

Adult↗
PubMed2001

Rapid dephosphorylation of eIF4E by dietary protein in the skeletal muscle and liver of food-deprived rats.

The effect of dietary protein on eIF4E phosphorylation was examined in rats starved for 18 h and then fed on either a 20% casein diet (20C) or a protein-free diet (0C). Refeeding with the 20C diet, but not the 0C diet, resulted in partial dephosphorylation of eIF4E in both the skeletal muscle and liver. The results suggest that the dephosphorylation of eIF4E in response to food intake was regulated by the increase in plasma amino acid concentration that occurred after feeding with the 20C diet.

Amino Acids↗
PubMed2001

Lipoprotein analysis using agarose gel electrophoresis and differential staining of lipids.

We established a strategy to directly measure cholesterol and triglyceride levels of each lipoprotein fraction using a combination of agarose gel electrophoresis and differential staining. The cholesterol and triglyceride levels determined by electrophoresis correlated significantly with those of ultracentrifugation. The correlation coefficients between these methods were, for cholesterol levels 0.975(very low density lipoproteins, VLDL), 0.986(low density lipoproteins, LDL) and 0.965(high density lipoproteins, HDL) and for triglyceride levels 0.994(VLDL), 0.963(LDL) and 0.959(HDL) respectively. Both intra-and inter-assays showed low values of coefficients of variation (CV) (less than 3.57%). We observed a strong linearity between staining and triglyceride concentration. An increased VLDL-cholesterol was observed in type III subjects, a result which enabled distinction between type III and type IIb or type V lipoproteinemia. The method revealed lipoprotein patterns in some samples otherwise unexpected from their corresponding serum lipid parameters. Analyses of these electrophoretic patterns thus provide an effective technique to classify types of hyperlipidemia defined by the WHO. Furthermore, quantitative measurement of chylomicrons, usually difficult, proved to be achievable, providing an additional analysis of postprandial hyperlipidemia and the exact measurement of LDL-cholesterol after diet. Consequently, we recommend this simple and easy method for clinical evaluation of abnormalities in lipoprotein profiles.

Chylomicrons↗
PubMed2001

[Pulmonary granulomatous lesion with severe chest pain and hemoptysis: a case report].

We encountered a rare case of pulmonary granulomatous lesion accompanied with severe chest pain and hemoptysis. A 42-year-old man visited our hospital complaining of hemosputum. A chest radiograph showed a nodular shadow in the left lower lung field. Further examinations including fiberoptic bronchoscopy, bronchoalveolar lavage and transbronchial lung biopsy did not suggest a diagnosis. During the course of his illness, he suffered an episode of severe chest pain which could be controlled only by intravenous morphine chloride (10 mg). The chest radiograph at the time showed a broad infiltration in the left lower lung field. However, the lung perfusion scintigram taken 2 days before demonstrated decreased blood flow in the same field. We waited for the infiltration in the chest radiograph to diminish and then performed partial resection of the left lower lobe, thus terminating both hemosputum and chest pain. Histological examination showed a cavitary lesion in the periphery of the lung, surrounded by large numbers of infiltrating plasma cells and lymphocytes, among which were many hemosiderinladen macrophages. A small amount of mycelium, considered to be Nocardia or fungus, was seen in the cavity wall. These findings may indicate that an infection had contributed to the formation of a hemorrhagic granulomatous lesion, and that this lesion caused chest pain mainly because of the pleuritis and the decrease in the local pulmonary circulation.

Adult↗
PubMed2001

Sickness absence and shift work among Japanese factory workers.

To investigate the effect of shift work on long-term sickness absence (more than 7 calendar days), an 8-year follow-up study was carried out in a factory in Japan. The participants were male employees aged 18-54 years who were engaged in manufacturing sites. Shift patterns were classified by the number of non-daytime working days during the previous one-year. The causes of sickness absence were classified into three groups, 1) causes except injury, diseases of the musculoskeletal system and connective tissue, 2) injury, 3) diseases of the musculoskeletal system and connective tissue. The analysis of long-term sickness absences was based on the first occurrence. The age-adjusted incidence of sickness absence among shift workers who were on non-daytime shifts more than two-thirds of working days during the previous one year was significantly higher than that among other workers. After adjusting for confounding factors, a significant high risk still existed for this group of workers taking sickness absence for all causes and causes except for injury and the musculoskletal disorders. These findings suggest that shift workers who are engaged on a particular shift schedule are more likely to take leave due to sickness.

Accidents, Occupational↗
PubMed2000

Endoscopic resection of a pelvic neurogenic tumor through the retroperitoneal approach.

A pelvic neurogenic tumor resected endoscopically through the retroperitoneal approach is described. Close examination of a 62-year-old man who complained of dull pain in the lower abdomen revealed a tumor on the posterior surface of the iliacus muscle. The tumor was extracted endoscopically without the need for a laparotomy. This procedure involves a less invasive approach that may be useful for benign retroperitoneal pelvic tumors.

Endoscopy↗
PubMed2000

Renal effects of cadmium exposure in cadmium nonpolluted areas in Japan.

Long-term exposure to cadmium (Cd) causes renal damage in the general population. The maximum allowable urinary Cd concentration, which was calculated from our previous study performed in a Cd-polluted area, was almost the same as the mean urinary Cd concentration of people living in nonpolluted areas. We assessed whether environmental Cd exposure is related to renal dysfunction of people in nonpolluted areas in Japan. Blood and urine samples were collected from 2753 subjects (1105 men and 1648 women) ages over 50 years old in three nonpolluted areas. Blood was analyzed for Cd and urine was analyzed for Cd, total protein, beta(2)-microglobulin (beta(2)-mg), and N-acetyl-beta-D-glucosaminidase (NAG). Cd in blood or urine was employed as indicators of internal dose; and urinary total protein, beta(2)-mg, and NAG were used as an indicator of renal dysfunction. Multiple regression analysis and logistic regression analysis were performed to clarify the dose-effect and dose-response relationship between blood or urinary Cd concentration and indicators of renal dysfunction. Multiple regression analysis demonstrated a significant dose-effect relationship between Cd in blood and urine and indicators of renal dysfunction. Logistic regression analysis also showed that the probability that individual subjects would have abnormal values of the renal variables was significantly related to Cd in blood and urine.

Acetylglucosaminidase↗
PubMed2000

Haemorrhagic complication following percutaneous transluminal angioplasty for carotid stenosis.

We report 2 cases with haemorrhagic complications following percutaneous transluminal angioplasty (PTA) for carotid stenosis. Computed tomography (CT) scanning of these cases demonstrated diffuse subarachnoid haemorrhage in 1 case, and intracerebral haemorrhage in the other case on the next day after PTA. In the latter case, we measured cerebral blood flow velocity and mean transit time with transcranial doppler (TCD) and dynamic CT scan, which demonstrated remarkable increases in the blood flow velocity and peak height, respectively. From these results, postoperative hyperperfusion was suggested to have caused haemorrhagic complications.

Aged↗
PubMed2000

Reduced stability of retinoblastoma protein by gankyrin, an oncogenic ankyrin-repeat protein overexpressed in hepatomas.

Hepatocellular carcinoma (HCC) is one of the most common cancers in Asia and Africa, where hepatitis virus infection and exposure to specific liver carcinogens are prevalent. Although inactivation of some tumor suppressor genes such as p53 and p16INK4Ahas been identified, no known oncogene is commonly activated in hepatocellular carcinomas. Here we have isolated genes overexpressed in hepatocellular carcinomas by cDNA subtractive hybridization, and identified an oncoprotein consisting of six ankyrin repeats (gankyrin). The expression of gankyrin was increased in all 34 hepatocellular carcinomas studied. Gankyrin induced anchorage-independent growth and tumorigenicity in NIH/3T3 cells. Gankyrin bound to the product of the retinoblastoma gene (RB1), increasing its phosphorylation and releasing the activity of the transcription factor E2F-1. Gankyrin accelerated the degradation of RB1 in vitro and in vivo, and was identical to or interacted with a subunit of the 26S proteasome. These results demonstrate the importance of ubiquitin-proteasome pathway in the regulation of cell growth and oncogenic transformation, and indicate that gankyrin overexpression contributes to hepatocarcinogenesis by destabilizing RB1.

3T3 Cells↗
PubMed2000

Expression of testicular fatty acid-binding protein PERF 15 during germ cell apoptosis.

PERF 15 is a testicular germ cell specific fatty acid-binding protein (FABP) isolated from rat. Indirect immunofluorescent analysis of juvenile rat testis showed that there were some strongly PERF 15-positive spermatocytes. These cells showed unclear nuclear structure and were predicted to undergo apoptosis. Apoptosis in germ cells is an important regulatory event to limit the number of germ cells in the seminiferous epithelium, but the physiological significance and molecular mechanisms of this testicular germ cell apoptosis are poorly understood. To determine whether PERF 15 participates in germ cell apoptosis, juvenile rat testis was examined by immunohistochemical and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) methods. Strongly PERF 15-positive cells and TUNEL-positive cells were co-localized in adjacent sections. Exposure to methoxyacetic acid (MAA), known to induce apoptosis in spermatocytes, increased the number of strongly PERF 15-positive cells in 25-day-old rats' testes. Therefore, it seems that PERF 15 is involved in both spermatogenesis and testicular germ cell apoptosis.

Acetates↗
PubMed2000

Engineering analysis of diamond-like carbon coated polymeric materials for biomedical applications.

Diamond-like carbon (DLC) films have received much attention recently owing to their properties, which are similar to diamond: hardness, thermal conductivity, corrosion resistance against chemicals, abrasion resistance, good biocompatibility, and uniform flat surface. Furthermore, DLC films can be deposited easily on many substrates for wide area coat at room temperature. DLC films were developed for applications as biomedical materials in blood contacting-devices (e.g., rotary blood pump) and showed good biocompatibility for these applications. In this study, we investigated the surface roughness by Atomic Force Microscopy (AFM) and Hi-vision camera, SEM for surface imaging. The DLC films were produced by radio frequency glow discharge plasma decomposed of hydrocarbon gas at room temperature and low pressure (53 Pa) on several kinds of polycarbonate substrates. For the evaluation of the relation between deposition rate and platelet adhesion that we investigated in a previous study, DLC films were deposited at the same methane pressure for several deposition times, and film thickness was investigated. In addition, the deposition rate of DLC films on polymeric substrates is similar to the deposition rate of those deposited on Si substrates. There were no significant differences in substrates' surface roughness that were coated by DLC films in different deposition rates (16-40 nm). The surface energy and the contact angle of the DLC films were investigated. The chemical bond of DLC films also was evaluated. The evaluation of surface properties by many methods and measurements and the relationship between the platelet adhesion and film thickness is discussed. Finally, the presented DLC films appear to be promising candidates for biomedical applications and merit investigation.

Anticoagulants↗
PubMed2000

The depressor function of biceps on the head of the humerus in shoulders with tears of the rotator cuff.

We investigated the function of biceps in 18 patients (19 shoulders) with lesions of the rotator cuff. Their mean age was 59 years. Another series of 18 patients (19 shoulders) with normal rotator cuffs as seen on MRI acted as a control group. Their mean age was 55 years. A brace was used to maintain contraction of biceps during elevation. Anteroposterior radiographs were obtained with the arm elevated at 0 degrees , 45 degrees and 90 degrees with and without contraction of biceps. The distance between the centre of the head of the humerus and the glenoid was compared in the two groups. We found that in the group with tears there was significantly greater proximal migration of the head of the humerus at 0 degrees and 45 degrees of elevation without contraction of biceps but depression of the head of the humerus at 0 degrees, 45 degrees and 90 degrees when biceps was functioning. We conclude that biceps is an active depressor of the head of the humerus in shoulders with lesions of the rotator cuff.

Adult↗
PubMed2000

Effects of biceps loading and arm rotation on the superior labrum in the cadaveric shoulder.

Effects of loading the long head of the biceps brachii (LHB) and arm rotation on the strain of the superior labrum (anterior and posterior) in 10 fresh frozen cadaveric shoulder joints were studied. Loads were applied to the rotator cuff muscles to stabilize the humeral head. The strain of the anterior and posterior portions of the labrum with the biceps loaded with 0.42 kg, 1.36 kg, and 2.31 kg were measured using linear transducers. The humerus was rotated externally (30, 45, 60, and 90 degrees) and internally (30, 45, and 60 degrees) with the arm elevated 60 degrees at glenohumeral joint (simulated 90 degrees elevation of arm to the trunk). The strain increased with an increase in the weight of the load to LHB and with increase in rotation angle both internally and externally. Since the strain in the posterior portion was larger than that of the anterior portion it seems likely that the labrum, especially the posterior portion, is subject to large strain during biceps loading and arm rotation.

Aged↗