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Biomedical subjects

M Okamura

Publications and source records attributed to M Okamura.

At least 91 records · Page 5Linked to original sources

Therapeutic effect of intradermal injections with difucosyl lactosamine (dimeric Lex) on patients with rheumatoid arthritis.

As reported by us, a new myeloid cell population with an oncofetal membrane marker, dimeric Lex (di-Lex; III3FucV3 FucnLc6), was found in the epiphyseal bone marrow adjacent to the involved joints of patients with severe rheumatoid arthritis (RA). Patients with RA received intradermal (id) injections of di-Lex incorporated in liposome or of high molecular weight glycoprotein, or tumor associated carbohydrate antigen (TCA), containing the same carbohydrate epitope as di-Lex. The epiphyseal myeloid cells were reduced or sometimes eliminated during id injection. In random trials of id injection, observation under clinical and laboratory conditions showed improvement in 63% (17/27) of the patients treated for 6 months with appropriate doses of di-Lex (III3FucnLc4), and in 72% (31/43) of those treated with an identical protocol for TCA. However, id injection with monomeric Lex had no effect.

Adult↗

[Nephrosclerosis: current status].

Nephrosclerosis is the most typical and widespread renal manifestation of hypertension and can be judged as the pathological hallmark of essential hypertension. Nephrosclerosis is an important and frequent cause of progressive renal disease, however, information in the literature on the risk of developing renal failure in the course of essential hypertension is sparse. Traditionally, nephrosclerosis was thought to result from glomerular ischemia. Alternatively, glomerular sclerosis in hypertension may result from glomerular hyperperfusion or hypertension. Studies in experimental models of renal disease have identified a promising intervention with either Ca antagonists or angiotensin-converting enzyme inhibitors. Application of these therapies to patients with nephrosclerosis should await the results of careful clinical trials.

Angiotensin-Converting Enzyme Inhibitors↗

[A combined operation of aortic valve replacement and bullectomy for aortic valve stenosis and giant bulla].

A 61-year-old male with aortic valve stenosis and giant bulla, whose respiratory function was very poor, successfully underwent a combined operation of aortic valve replacement and bullectomy. Firstly aortic valve replacement was performed under cardio-pulmonary bypass, and after coming off bypass, giant bulla was resected via median sternotomy. Postoperative respiratory function was improved remarkably (VC: per-op 1.89 l, post-op 2.53 l, FEV1.0: pre-op 0.74 l, post-op 1.13 l) and also his clinical symptom improved from Hugh-Jones IV. to I. postoperatively.

Aortic Valve↗

Effects of environmental factors on maxillofacial elastomers: Part III--Physical properties.

The physical properties of four currently used and two recently introduced maxillofacial prosthetic materials were evaluated after the materials were subjected to the following seven environmental variables: natural weathering, normal aging, two types of adhesives, two types of cleaning agents and cosmetics. Ultimate tensile strength, percent elongation, tear strength, and Shore A hardness were evaluated. The physical properties recorded for the currently used materials were consistent with previous studies. Although the properties of the recently introduced materials were similar to those currently in use, one of the new materials, A-2186, showed high strength values, although it was one of the softest materials tested. Unfortunately, this new material lost these advantageous characteristics as it was weakened and made harder by most of the tested environmental variables.

1-Propanol↗

Study on the environmental behavior of Chernobyl-derived radionuclides in Kyushu Island, Japan.

The environmental behavior of Chernobyl-derived radionuclides in Kyushu Island was investigated for one month after the accident. The radioactivity level in airborne dusts was two orders of magnitude lower than that observed in Western Europe. The distribution of 131I in airborne dusts shifted to a larger particle size compared with other radionuclides. The radionuclide concentration in seaweeds varied depending on the geographical situation where the sampling was done. The biological half-lives in red algae were calculated to be 17.4 d and 32.9 d for 131I and 103Ru, respectively. The concentration factors in red algae were estimated to be 3 x 10(3) and 5 x 10(3) for 131I and 103Ru, respectively. The cooking effect of 131I in seaweeds and the committed effective dose equivalent through ingestion of seaweed were also evaluated.

Accidents↗

A study of embolizing materials for chemo-embolization therapy of hepatocellular carcinoma: embolic effect of cisplatin albumin microspheres using chitin and chitosan in dogs, and changes of cisplatin content in blood and tissue.

Hepatic artery of dogs was embolized with cisplatin (CDDP) albumin microspheres containing chitin and chitosan to investigate the in vivo CDDP release kinetics from CDDP albumin microspheres, the CDDP cumulative characteristics in the liver, and the influence of microsphere administration on hepatic tissue. Results showed that changes in blood CDDP content were dependent on CDDP albumin microsphere type and that release kinetics were better sustained when chitin was added to the microspheres or when the microspheres were treated with chitosan. In particular, the administration of CDDP in the chitin-containing CDDP chitosan albumin microspheres showed a blood CDDP content of approximately 0.26 micrograms Pt/ml 14 d after administration. The administration of chitin-containing or chitosan treated CDDP microspheres showed a CDDP content in the hepatic tissue of 0.14 to 0.23 micrograms Pt/g 28 d after administration. They also showed better control of CDDP release than those without chitin or chitosan treatment. No CDDP influence on hepatic tissue was observed. We conclude that, even in vivo, chitin and chitosan are effective embolic materials.

Animals↗

A study of embolizing materials for chemo-embolization therapy of hepatocellular carcinoma: antitumor effect of cis-diamminedichloroplatinum(II) albumin microspheres, containing chitin and treated with chitosan on rabbits with VX2 hepatic tumors.

As an effective therapy for hepatocellular carcinoma, hepatic arterial chemo-embolization therapy has been widely used, and many embolizing materials have been extensively investigated. In the present study, we prepared various types of cis-diamminedichloroplatinum(II) (CDDP) albumin microspheres using chitin and chitosan, both of which have attracted considerable attention as new non-toxic biological polymer materials having favorable characteristics such as immune adjuvant activity, biological compatibility, and biodegradation. Hepatic artery of rabbit hepatic cancer models, which had transplanted VX2 tumors, were embolized with various types of microspheres. The anti-tumor effects and tumor-targeting of the microspheres, and the effects of the microspheres administration on the hepatic tissue were investigated. As a result, anti-tumor activity of the microspheres was increased by the addition of chitin-containing or chitosan treated materials; tumor growth rates of chitin addition and chitosan treated groups were approximately 160% and 120%, respectively, and were significantly lower than that of the non-treatment groups with a rate of approximately 580%. However, complete inhibition of tumor growth might have been impossible. Anti-tumor activity was increased by the addition of chitin-containing or chitosan treated materials. Whereas the growth inhibitory effect was insufficient, in order to potentiate anti-tumor activity, higher CDDP contents and sustained release of CDDP at a high level from microsphere and so on should be essentially improved for the near future. The CDDP level in hepatic tissue following the administration of microspheres was increased by adding chitin to the microspheres or by treating the microspheres with chitosan.(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗

Evaluation of cardiac motion and function by cine magnetic resonance imaging.

Cardiac cine magnetic resonance imaging (MRI) was studied to evaluated the cardiac motion and function, and a water-stream phantom study was performed to clarify whether it was possible to quantitatively assess the valvular regurgitation flow by the size of the flow void. In normal subjects, the left ventricular (LV) epicardial apex swung up to the base only a few millimeters, and the mitral annulus ring moved about 14 mm as mean value toward the apex during systole. Those motions of mitral annulus ring may contribute to the left atrial filling. The LV longitudinal shortening and torsions were shown by the tagging method. This tagging method was the best method for estimating cardiac motions. Cardiac cine MRI using software including a modified Simpson's method program and a wall motion analysis program was useful for routine LV volumetry and wall motion analysis because it was a simple and reliable method. Our water-stream phantom studies demonstrated that it might be difficult to perform quantitative evaluation of valvular regurgitation flow by using only the size of the flow void without acquiring information relating to the orifice area.

Adult↗

Abnormalities of pulmonary function in patients with non-insulin-dependent diabetes mellitus.

To examine the possible association between the vascular complications of diabetes and changes in pulmonary function, we performed pulmonary function tests including assessment of the diffusing capacity (%DLco) in 80 patients with non-insulin-dependent diabetes mellitus (45 males and 35 females) without overt lung or heart disease. The mean age of the subjects was 57.9 years and the mean duration of diabetes was 10.8 years. The %DLco decreased significantly as the duration of diabetes increased (r = -0.38, p less than 0.01), and the same relationship was also observed in non-smoking subjects (N = 37). The reduction in %DLco was greater in patients with diabetic microangiopathy (especially nephropathy) and in those treated with insulin. Other pulmonary function tests (%VC, FEV1.0, PaO2 and PaCO2) showed no relationship to the duration of diabetes, the degree of microangiopathy or the type of treatment. These results suggest that diabetic microangiopathy may play an important role in the decrease of %DLco.

Aged↗

Platelet-derived growth factor gene expression in the kidney of malignant hypertension.

To examine the pathogenetic role of platelet-derived growth factor (PDGF) in hypertensive kidney damage, we studied the gene expression of PDGF A-chain and B-chain in an animal model of malignant hypertension. Experimental malignant hypertension induced by unilateral nephrectomy combined with deoxycorticosterone and salt loading in the spontaneously hypertensive rat resulted in severely elevated blood pressure and renal histological damage, characterized by necrotizing vasculitis. Using reverse transcription-polymerase chain reaction analysis followed by Southern blot analysis, we observed that PDGF B-chain gene expression was increased in the kidney of experimental malignant hypertension and was correlated with the severity of glomerular damage, while PDGF A-chain gene expression was unaffected. Antihypertensive treatment with manidipine reduced glomerular damage and a decreased gene expression of PDGF B-chain. These results suggest that PDGF B-chain may have a role in mediating hypertensive kidney damage.

Animals↗

[Assessment of urinary beta-core fragment of hCG as a tumor marker of cervical cancer].

Beta-core fragment (beta-CF), a fragment of the hCG beta-subunit missing its carboxyterminal peptide, can be detected in the urine of women throughout pregnancy or in trophoblastic disease. It is also found in the urine of patients with nontrophoblastic cancers. We examined the beta-CF level in urine samples from patients with cervical cancer and assessed its value as a tumor marker. beta-CF was measured by an enzyme immunoassay with hCG beta-core directed monoclonal antibody No. 229. Based on the cut-off value (0.2ng/ml) from control subjects, the overall positivity rate for urinary beta-CF in the cervical cancer group was 45% (57 of 128 patients), increasing from 32% (23 of 73) in stage I to 100% (2 of 2) in stage IV. These positivity rates exceeded or equaled those of the other markers, SCC, CEA, CA19-9 and CA125, simultaneously measured in the patients' serum. There was no significant difference between the positivity rates for the two histological types of cancer, squamous cell carcinoma and adenocarcinoma. Serial determination in 28 patients with increased urinary beta-CF prior to therapy showed that 24 patients had a decreased concentration after successful treatment, but 2 of 4 patients with still increased urinary beta-CF during or after treatment subsequently relapsed. The determination of urinary beta-CF may provide a useful tool in monitoring the response to treatment in patients with cervical cancer.

Adenocarcinoma↗

Prothrombin Himi; an abnormal prothrombin characterized by a defective thrombin activity.

An abnormal prothrombin has been detected in a 26-year-old female, who had no history of excessive bleeding. Prothrombin activity was approximately 10% when measured using either the classical one-stage assay or the assay with Echis carinatus venom, whereas prothrombin antigen level was normal. In keeping with current nomenclature practices, the abnormal prothrombin was designated "Prothrombin Himi". The electrophoretic behavior and calcium binding properties of Prothrombin Himi did not differ significantly from normal. Prothrombin Himi was isolated by chromatography on Q-Sepharose. Electrophoretic migration of the purified abnormal prothrombin on SDS-PAGE was normal. Upon prothrombin activation by Echis carinatus venom, the clotting activity produced from Prothrombin Himi was only 37% of the normal level after 90 minutes of the activation time, where as the amidolytic activity was almost the same as normal. The cleavage patterns of Prothrombin Himi by factor Xa or Echis carinatus venom investigated by SDS-PAGE, were found to be normal. These results indicate that Prothrombin Himi was characterized by a defective thrombin enzymatic activity.

Adult↗

Enhanced expression of fibronectin by cmd/cmd chondrocytes and its modulation by exogenously added proteoglycan.

Cartilage matrix deficiency (cmd/cmd) in mice is a genetic disorder associated with the failure of chondrocytes to synthesize the core protein of cartilage proteoglycan monomer (cartilage-PG). Immunohistochemical and biochemical analyses revealed enhanced accumulation of fibronectin in culture of cmd/cmd chondrocytes as well as in mutant cartilage tissue in vivo. Purified cartilage-PG, when added exogenously to a culture of cmd/cmd chondrocytes, caused a reduction in abnormal accumulation of fibronectin over several subsequent days of culturing. Using a fibronectin cDNA probe, we showed that, on the basis of total RNA, the fibronectin mRNA level was four or eight times higher in cmd/cmd chondrocytes than in the normal. The level of fibronectin mRNA in cmd/cmd cells was lowered by culturing the cells in the presence of added cartilage-PG. These findings suggest that the abnormal accumulation of fibronectin in the mutant cell culture is primarily due to elevation of fibronectin mRNA level, and that cartilage-PG in the extracellular matrix may affect the regulation of fibronectin biosynthesis at the steady-state level of mRNA.

Animals↗

[A case of successful treatment of aneurysms of the suture line following Bentall's operation].

A 33-year-old male who had received Bentall's operation 10 years ago was admitted to our hospital with severe chest pain. The pseudoaneurysm at the right coronary ostium was observed on angiography and CT scan. He underwent the repair of the anastomosis between the graft and the right coronary ostium under extracorporeal circulation. Although he was discharged from the hospital asymptomatically, he was again admitted to our hospital with severe chest pain and back pain 4 months after re-operation. Aneurysmal formation of the ascending aorta due to blood leakage from the distal anastomotic suture line was observed and the graft was compressed by hematoma on angiography and CT scan. He underwent re-operation of the distal anastomosis of the graft, and could be discharged from the hospital uneventfully.

Adult↗

[Electron microscopic and immunological studies concerning the effect on the antitumor activity of sizofiran (SPG) combined with radiotherapy for cervical cancer].

It has been well known that Sizofiran (SPG) cultured from the Schizophyllum commune Fries activates the macrophages and induces the cytotoxic lymphocytes in some cancers. In this study, we observed electronmicroscopically the macrophages around the cancer tissue from the patients with uterine cervical cancer after the treatment with SPG. At the same time, their immune responses were also examined by analyzing lymphocyte subsets, ADCC and NK activity in peripheral blood. A considerable number of erratic macrophage with well developed Golgi apparatus, endoplasmic reticulum and mitochondria were found in the uterine cervical cancer tissue from the patients treated with SPG under radiotherapy. Simultaneously, we identified the lysosome granules with a bright filament structure which appeared to be specific for SPG. In the immune responses evaluated by analyses of peripheral blood, the number of CD 16+ cells and NK activity significantly increased in the patients treated with SPG as compared with non-treated group. The present results indicate that SPG-immunotherapy combined with radiotherapy not only induces the cytotoxic activity of macrophage but also augments NK activity in the patients with uterine cervical cancer.

Carcinoma, Squamous Cell↗

[A case of young woman with giant ovarian tumor as the manifestation of leukemic recurrence].

Following rapid development of chemotherapy to leukemia, reports about tumor-forming-leukemia are on the increase. But ovarian tumor-forming-leukemia is relatively rare, hence not enough is known about it. Recently, the authors experienced a case of young woman with recurrent leukemia which manifested as a giant ovarian tumor. She suffered from acute lymphocytic leukemia (ALL) in February, 1986, and received chemotherapy (predonisolone and cytocine arabinoside) until complete remission in peripheral blood. But she developed a giant abdominal tumor in May, 1988, and admitted to our hospital for close examination and treatment. Preoperative blood examination was within normal range, and peripheral blood smear revealed no leukemic blasts. She had a giant abdominal tumor occupying whole abdominal cavity, and the tumor showed solid pattern in ultra-sonography, CT and NMR-CT. Malignant lower abdominal tumor was suspected, and simple abdominal hysterectomy, bilateral salphingo-oophorectomy and omentumectomy was performed on 27th. May, 1988. A giant abdominal tumor developed from left ovary, infiltrating to the uterus through left Fallopian tube, and metastatic lesion at omentum were present. Postoperative pathological findings in immunochemistry showed that the tumor was recurrence of ALL as tumor-forming-leukemia. After operation, she was treated in the department of internal medicine for postoperative chemotherapy (TCMP-therapy 1 kur) and discharged in December, 1988. She is alive and healthy 10 months after operation, and reveals no signs of recurrence. It was important to recognize lower abdominal tumor in leukemic patients as gynecologic problem, and significance of surgical approach to ovarian tumor-forming-leukemia was indicated.

Adult↗