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Biomedical subjects

M Okada

Publications and source records attributed to M Okada.

At least 541 records · Page 30Linked to original sources
PubMed1998

Platelet epidermal growth factor in thyroid disorders.

We evaluated the concentration of epidermal growth factor (EGF) in platelets, serum and plasma obtained from 47 patients with Graves' disease, 7 with hypothyroidism and 20 healthy subjects. The platelets of the subjects were collected from platelet rich plasma and lysed by freezing and thawing. Subsequently the platelet debris was treated with Triton X-100. The EGF concentration was determined by homologous radioimmunoassay. The concentration of EGF in the platelets in 14 patients with untreated Graves' disease was significantly higher than that in the healthy controls. After treating these 14 patients with antithyroid agents, the EGF concentration in the platelets decreased to the level of the healthy controls. The EGF concentration in the platelets in the 7 untreated hypothyroid patients decreased after replacement therapy with thyroxine. The mean volume of the platelets in the 14 patients with untreated Graves' disease was significantly larger than in the control and decreased after treatment with antithyroid agents. The serum and plasma levels of EGF in the 7 untreated hypothyroid increased after replacement therapy. In conclusion, thyroid function affected the concentration of EGF in the platelets of patients with thyroid disorders.

Adult↗
PubMed1998

[League against pain: an experiment in extracurricular teaching].

Although anatomical and physiological base of pain are subject of the basic sciences in health undergraduate curriculum, it is not usually to have pain concepts and therapy into undergraduate programs. Describing the League Against Pain objectives and organization and the students' opinions about their participation in this league were the aim of this study. The League Against Pain Statute was consulted to describe its objectives and organization. The opinions of all of the students that attended the League Against Pain program in 1995 and 1996 were investigated. The League Against Pain was organized at an university hospital in 1995. It is composed by nurses and medical students and professionals (physicians in varied specialties and nurses). All the activities are voluntary and the students are the managers of the League. The objectives of the League are: improving the quality of teaching of pain subjects in nursing and medical schools; developing research in epidemiological, clinical and therapeutics aspects of pain and to promote a model of multidisciplinary and multiprofessional assistance. The most frequent students' opinions about their participation in the League were: their abilities in pain control and in professional and client relationship were improved; they achieved their objectives; that pain should be included into undergraduate courses; and they would recommend the League for other students. The results are promising. The students' opinions about their experience in the League Against Pain have showed that the League Against Pain could be an usefull model to introduce pain subjects to undergraduate nursing and medical students.

Attitude of Health Personnel↗
PubMed1998

Prognosis of accidental low back pain at work.

Accidental low back pain at the workplace was classified into two groups; 177 cases of the organic type and 176 cases of the non-specific type. Concerning the recuperation period, the length of leave, and the amount of compensation for recuperation, medical cost and leave of absence, a comparison was made between two groups. Regarding age, sex, and the type of work, no difference was found between the organic and the non-specific groups. However, the non-specific group showed lower values than the organic one for the duration of recuperation and leave and the amount of compensation for medical cost and leave of absence. Multiple regression analysis showed that the difference in the type of low back pain had more influence on the duration and cost than that in sex and age. The prognosis of non-specific low back pain is better than that of organic one in terms of cost and duration.

Accidents, Occupational↗
PubMed1998

Magnetometric evaluation for the effect of chrysotile on alveolar macrophages.

Alveolar macrophages are thought to play an important role in fibrogenesis due to asbestos exposure. In this experiment, we evaluated the effect mainly by unique magnetometry and also by conventional methods such as lactate dehydrogenase (LDH) activity measurement and morphological observations. Alveolar macrophages obtained from Syrian golden hamsters by bronchoalveolar lavages were exposed 18 hours in vitro to Fe3O4 as an indicator for magnetometry and chrysotile for experiments. A rapid decrease of the remanent magnetic field, so called "relaxation", was observed after the cessation of an external magnetic field in macrophages phagocytizing Fe3O4 alone, while relaxation was delayed in those concurrently exposed to chrysotile. Since relaxation is thought due to the cytoskeleton-driven random rotation of phagosomes containing iron oxide particles, chrysotile is considered to interfere with the cytoskeletal function of macrophages. Release of LDH from chrysotile-exposed macrophages into the medium was recognized, but it was not significantly higher than the controls. Apoptosis was negligible in macrophages exposed to chrysotile by the DNA ladder detection, the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling method and morphological observations. Electron microscopical examinations revealed early necrotic changes in macrophages exposed to chrysotile. These findings indicate that cell magnetometry detects impaired cytoskeletal function due to in vitro exposure to chrysotile.

Animals↗
PubMed1998

Subacute and chronic toxicity studies of triethylenetetramine dihydrochloride (TJA-250) by oral administration to F-344 rats.

Triethylenetetramine dihydrochloride (trientine-2HCl, TJA-250), a copper chelating agent used to treat Wilson's disease, was administered orally to male and female F-344 rats for 4 or 8 weeks at dosages of 0, 100, 350 or 1200 mg/kg/day or for 26 weeks at dosages of 50, 175 or 600 mg/kg/day. 4 or 8-week study. Two males receiving 1200 mg/kg/day died during week 8 of treatment. In males receiving 1200 mg/kg/day during weeks 5 to 8 of treatment, body weight gain and food consumption were decreased and hunched posture and thin build were observed. During week 4 or 8 of treatment urinalysis revealed, for males receiving 100 mg/kg/day or animals receiving 350 mg/kg/day or more, increased electrolyte outputs possibly due to the hydrochloride nature of trientine-2HCl, with low plasma alkaline phosphatase activities evident in animals receiving 350 or 1200 mg/kg/day. After 4 and 8 weeks, and during 8 weeks of treatment, high lung weights and bronchiolar epithelium hypertrophy and broncho-alveolar pneumonia were recorded for animals receiving 1200 mg/kg/day, and submucosal acute inflammation within the glandular region of the stomach was recorded for males receiving 350 or 1200 mg/kg/day and in all treated female groups. 26-week study. One male receiving 175 mg/kg/day and three males receiving 600 mg/kg/day died, showing lung changes. The body weight gain of animals receiving 600 mg/kg/day was slightly decreased. Blood chemistry and urinalysis examinations showed changes similar to those indicated in the 4- or 8-week study. The low plasma copper concentrations seen in males receiving 600 mg/kg/day, the slightly low liver copper concentrations found in animals receiving 600 or 175 mg/kg/day and the high urinary copper concentrations found in all treated groups, are attributed to the pharmacological action of trientine-2HCl. Histopathology revealed a dosage-related incidence and severity of focal chronic interstitial pneumonitis accompanied by fibrosis of the alveolar walls in females receiving 175 mg/kg/day or more and all treated male groups, but no significant pathological changes in the stomach. Apart from the histological changes found in the lung, all the above changes were reversible. In conclusion, the NOAEL of trientine-2HCl in this 26-week study was considered to be 50 mg/kg/day for females and less than 50 mg/kg/day for males.

Administration, Oral↗
PubMed1998

Dietary protein as a factor affecting vitamin B6 requirement.

Rats were fed 20 or 70% casein diets with varying amounts of vitamin B6 (B6), and the B6 content and B6-dependent enzymatic activity in their tissues were examined to determine the minimum requirement of B6 for animals subjected to different levels of dietary protein (i.e., 20%: 0, 1.45, 2.90, 5.80 mg pyridoxine (PN)/kg diet; 70%: 0, 2.90, 5.80, 8.70 mg PN/kg diet). B6 requirements for the rats were almost met in the 1.45 mg PN/kg 20% casein diet and the 2.90 mg PN/kg 70% casein diet when judged from the hepatic B6 content. However, almost twice the PN was required in both 20 and 70% casein diets when judged from PLP-enzymatic activity. The content of B6 vitamers in plasma appeared to be most sensitive to B6 status, though the satisfactory level is not known. It was confirmed that, in any case tested, a high-protein diet increased the requirement of B6.

Animals↗
PubMed1998

alpha-tocopherol protects the peroxidative modification of LDL to be recognized by LDL receptors.

BACKGROUND: Peroxidatively modified low-density lipoprotein (LDL) may contribute to the atherosclerotic process; therefore, protecting LDL against peroxidation may reduce or retard the progression of atherosclerosis. We evaluated the effect of alpha-tocopherol on copper-catalyzed LDL peroxidative modification. METHODS: The protective effects of alpha-tocopherol on copper-catalyzed LDL peroxidative modification were examined by measurement of the concentration of lipid hydroperoxides in LDL and by the provision of LDL cholesterol to lymphocytes via the LDL receptor-mediated pathway. RESULTS: The measurement of concentration of lipid hydroperoxides in LDL showed that alpha-tocopherol inhibited the peroxidative modification of LDL. Also, alpha-tocopherol preserved the ability of LDL to be recognized by LDL receptors in peripheral blood lymphocytes to the same extent as native LDL. CONCLUSION: These findings indicate that alpha-tocopherol may protect LDL against peroxidative modification, maintaining its ability to act as a ligand for LDL receptors in vivo.

Adult↗
PubMed1998

Efficacy of applied cardiovascular surgery techniques for extended resection in hepato-biliary-pancreatic malignancies.

The application of extracorporeal circulation (ECC) and vascular surgery techniques provide the possibility to resect severely advanced hepato-biliary-pancreatic (HBP) malignancies that had been adjudged unresectable hitherto. In this paper, recent two successful cases are reported for the purpose of indicating the efficacy of ECC and vascular surgery techniques in HBP surgery. Two patients had a cholangiocellular carcinoma and a carcinoma of the pancreatic head, those metastatic lymph nodes invaded to the portal veins and the hepatic arteries. These tumors could be resected en bloc with these Glissonian vessels using a centrifugal pump through veno-venous bypass. Reconstruction of these portal veins was performed with autologous external iliac vein graft. Postoperative angiographies showed no anastomotic leakage or occlusion on vascular anastomotic sites in both cases, and they have gone on uneventful postoperative courses. Application of cardiovascular techniques in the field of HBP surgery might expand surgical indication for advanced malignancies.

Bile Duct Neoplasms↗
PubMed1998

Two-step approach for the operation of male breast cancer: report of a case at high risk for surgery.

We report herein the rare case of a 61-year-old man with a history of dissecting aortic aneurysm as well as right breast cancer. He complained of abdominal pain due to a progress of aortic dissection in preparation for the radical operation for breast cancer. Blood pressure was initially controlled and he was administered a simple mastectomy under local anesthesia. One month after the first operation, a radical operation for breast cancer was successfully performed. The tumor was in stage II, and two years after the operation, the patient remained free of recurrent disease. This two-step approach for the operation of male breast cancer may be used as a treatment of breast cancer if a patient is too frail for normal surgery.

Adenocarcinoma↗
PubMed1998

Results of surgical treatment for thoracoabdominal aneurysm using cardiopulmonary bypass under moderate hypothermia and selective visceral artery perfusion.

From 1994 to 1997, 11 consecutive patients with thoracoabdominal aneurysms underwent surgery using cardiopulmonary bypass under moderate hypothermia (33 degrees C) and selective visceralartery perfusion for spinal cord and visceral organ protection. Distal perfusion pressure was maintained above 60 mmHg (mean) during cardiopulmonary bypass. In the four patients, one or two pairs of large intercostal arteries between Th10 and L2 were reimplanted. In the four patients, visceral and renal arteries were reconstructed. Surgical mortality rate within 1 month was 18.2% (2/11). One patient died of bleeding from old empyema and another of multiple organ failure. No patients had paraplegia. In conclusion, cardiopulmonary bypass with selective visceral artery perfusion under moderate hypothermia may contribute to the prevention of the occurrence of paraplegia and acute renal failure.

Aneurysm↗
PubMed1998

Hepatic microcirculation during transient hepatic venous occlusion--intravital microscopic observation using hepatic vein clamp model in the mouse.

The purpose of this experiment was to evaluate the etiology of hepatic dysfunction in patients difficult to wean from cardiopulmonary bypass. We hypothesized that increased central venous pressure and subsequent hepatic congestion during weaning from cardiopulmonary bypass would lead to hepatic dysfunction. To induce hepatic congestion in mice, we clamped the hepatic vein for fifteen min, and observed the microcirculation of the liver using an intravital microscope during clamping and the following 30 min of reperfusion. During reperfusion, non-reflow phenomenon, leukocytes adhesion to the wall of sinusoids, erythrocytes sludging, acute swelling of hepatic cells and narrowing of sinusoids were observed. These phenomena were indicative of warm ischemia-reperfusion injury of the liver itself. Based on these findings we concluded that, after repeated episodes of warm ischemia and reperfusion of the liver, hepatic cells would be damaged, and finally hepatic dysfunction was induced. To prevent hepatic dysfunction, repeated attempts to wean the patient from cardiopulmonary bypass should be avoided and increases central venous pressure should be prevented by early use of cardiopulmonary support.

Animals↗
PubMed1998

The prognostic factor of the surgically treated metastatic lung cancer.

Surgical treatment for metastatic lung tumor has also been aggressively performed to treat multiple or bilateral lesions recently. However, in some patients, metastatic pulmonary foci have recurred after surgery for metastatic lung tumor. These foci could not be controlled even after performing thoracotomy several times in some patients. In this study, we examined prognostic factors in patients undergoing surgery for metastatic lung tumor with respect to early relapse of metastatic pulmonary foci after surgery, and discussed strategies for improving long-term results. This study included 120 patients who underwent surgery for metastatic lung tumor in our department between November 1975 and November 1997. Overall, the 5-year survival rate was 37.1%. When results were compared among groups, there were no significant differences related to age, gender, primary organ, DFI, number of metastatic foci or surgical technique. However, the prognosis was significantly poorer in patients with recurrent metastatic pulmonary foci after surgery. Especially in patients with early relapse within 6 months after resection of the lung, the prognosis was markedly poor. Early relapse was an important factor involved in unfavorable surgical outcomes. The mechanism involved in the early relapse of metastatic pulmonary foci after surgery for metastatic lung tumor may be associated with the presence of several micrometastases that could not be recognized during surgery for metastatic lung tumor, that is, dormancy, in the lung. Surgical outcomes in patients with metastatic lung tumor will be improved if a method of controlling this increase in dormant metastases is established.

Adolescent↗
PubMed1998

Extra-anatomical bypass with EPTFE graft for residual pulmonary artery stenosis in Tetralogy of Fallot.

We describe the case of 35-year old woman who had undergone radical surgery to correct Tetralogy of Fallot malformation at the age of nine admitted to our hospital because of palpitation and exertional dyspnea. Angiography revealed 90% re-stenosis of the right pulmonary artery and grade IV tricuspid regurgitation. Right lung was perfused only 16.7% as shown by pulmonary perfusion scintigraphy. Interposition between the pulmonary trunk and right pulmonary artery using an EPTFE graft and tricuspid annuloplasty using a Duran ring was performed. Blood flow to the right lung improved markedly from 16.7% to 37.0% and her symptom disappeared completely.

Adult↗
PubMed1998

[Monitoring of CMV infection after bone marrow transplantation].

Cytomegalovirus interstitial pneumonitis (CMV-IP) is one of the most serious complication after allogeneic stem cell transplantation. In the recent reports, ganciclovir administration have been shown to be effective for CMV infection by using more sensitive detection methods such as PCR method and antigenemia assay. The risk factors of CMV infection pretransplant time are known as follows, such as 1. unrelated donor marrow, 2. TBI, 3. anti thymocyte globulin, 4. T cell depletion and 5. HLA mismatched donor. After transplantation period 1. acute GVHD and 2. use of steroid hormone are important risk factors. It is necessary to select the effective strategy for the prevention of CMV-IP after stem cell transplantation.

Antigens, Viral↗
PubMed1998

Diagnosis of the nutcracker phenomenon using two-dimensional ultrasonography.

We aimed to establish new criteria for the diagnosis of the nutcracker phenomenon (N phenomenon) using ultrasonography (US). The left renal vien (LRV) was examined with US in 125 children, divided into three groups, namely the macroscopic hematuria group (23 children), the microscopic hematuria group (52 children) and the control group (50 normal children) all without nephritis, urolithiasis and tumor. The following parameters were calculated: (1) the ratio of the diameter of the dilated part of the LRV (D) to that of the narrowed part of the same vein (N) (D/N ratio), (2) the ratio of D to the aortic diameter (A) (D/A ratio) and (3) the difference in diameter between the LRV and the right renal vein (RRV) (RVD difference). The D/A ratio and the RVD difference correlated significantly with the D/N ratio. This indicates that not only the D/N ratio but also the D/N ratio but also the D/A ratio and RVD difference can be used for diagnosing the N phenomenon. The cutoff levels for the three parameters were set at the mean + 2 SD of the values of the normal controls, that is, at 3.7 (D/N ratio), 0.75 (D/A ratio) and 1.7 mm (RVD difference). We made diagnoses of the N phenomenon when two or more parameters were over the cutoff level. According to these criteria, most patients with macrohematuria and one third of patients with microhematuria were positive for the N phenomenon. The D/A ratio and RVD difference were useful for diagnosing the N phenomenon, and as a result our criteria can reduce misdiagnosis for normal children.

Adolescent↗