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Biomedical subjects

K Ota

Publications and source records attributed to K Ota.

At least 397 records · Page 22Linked to original sources
PubMed1991

Evaluation of magnesium, calcium and aluminum metabolism in rats and monkeys maintained on calcium-deficient diets.

The epidemiology of amyotrophic lateral sclerosis (ALS) in the Western Pacific indicates that low concentrations of calcium (Ca) and magnesium (Mg) and high levels of aluminum (Al) in soil and water in these foci are etiologically important. To determine the biochemical derangements and metal deposition induced by chronic dietary deficiencies of Ca, we maintained experimental animals on several regimens. Male Wistar rats, weighing 100g, were fed either a standard diet, low Ca diet, low Ca-Mg diet, or low Ca-Mg diet with high Al for 90 days. Ca, Mg and Al content was determined in central nervous system (CNS) tissues and bone using inductively coupled plasma emission spectrometry (ICP). In separate studies, five male Japanese macaques (Macaca fuscata), weighing 3.5 to 5 kg, were fed alternately with diets, normal in Ca, low in Ca, low in Mg, low in Ca-Mg, or low in Ca-Mg with added Al for four-week periods. Serum Ca, Mg, Al, parathyroid hormone (PTH), bone Gla-protein (BGP) and alkaline phosphatase (ALP) were measured after feeding each dietary regimen. Ca and Mg levels in lumbar vertebrae and femur were significantly reduced and bone Al levels were significantly increased in rats fed diets deficient in Ca alone or diets low in Ca-Mg with or without added Al. Al content in bones was also higher in rats fed the Ca deficient diets. In monkeys fed the low Ca-Mg diet with added Al, reduced levels of serum Ca and Mg, serum PTH, BGP, and ALP were apparent. Our data support the conjecture that deranged bone mineralization induced by chronic dietary deficiency of Ca accelerates mobilization of Ca and Mg from bone and deposition in brain.

Aluminum↗
PubMed1991

Aluminum deposition in the central nervous system of patients with amyotrophic lateral sclerosis from the Kii Peninsula of Japan.

Chronic dietary deficiency of calcium (Ca) and magnesium (Mg) with excessive intake of aluminum (Al) and manganese (Mn) has been implicated in the pathogenesis of high incidence amyotrophic lateral sclerosis (ALS) in the Western Pacific. We report two cases of ALS from the Kii Peninsula of Japan with markedly elevated concentrations of Al in central nervous system (CNS) tissues. Six pathologically verified cases of ALS and five neurologically normal controls were studied. Levels of Al, Ca and phosphorus (P) were determined simultaneously by neutron activation analysis (NAA), and Mg concentration was measured by inductively coupled plasma emission spectrometry (ICP) in 26 CNS regions. Al concentrations in the precentral gyrus, internal capsule, crus cerebri and spinal cord were significantly increased in two ALS patients, compared with those of controls. Mean Al concentrations of the 26 CNS regions in these two patients were also higher than those of controls and of the four other ALS cases (p less than 0.01). By contrast, Mg concentrations in the 26 CNS regions were markedly reduced in the ALS cases, compared with controls (p less than 0.01), and the Ca/Mg ratios were significantly increased in the ALS cases (p less than 0.01). Our data indicate that high-incidence ALS in the Western Pacific may result from Ca-Mg dysmetabolism with resultant deposition of Al.

Aged↗
PubMed1991

Clinical application of modified polyurethane graft to blood access.

Based on a study of 34 clinical implantations, a porous poly(ether-urethane) graft developed for blood access was evaluated. Although it became clear that the graft has several advantages over expanded polytetrafluoroethylene (E-PTFE), it was also revealed that the occlusion at the anastomotic site was more frequently observed than that with E-PTFE. To improve the patency rate, a small modification of the luminal surface was attempted to give a better anchoring of the neointima. The results so far are better than those with the unmodified graft. However, the number of cases is small and the period of observation is short. More work will be necessary to confirm these preliminary results.

Arteriovenous Shunt, Surgical↗
PubMed1991

[Burkitt's lymphoma with monoclonal pattern (IgG, kappa type) of cytoplasmic immunoglobulin--clinical report and review of Japanese literature].

A 52-year-old male was admitted to the hospital because of abdominal mass. Bone marrow examination revealed 26% blasts, which morphology was L3 in FAB criteria. Abdominal tumor was resected and histologic feature of the tumor was malignant lymphoma, small non-cleaved cell, Burkitt's. Lymphoma cells from the resected tumor were cultured and a cell line was established. Cytological studies of the original tumor cells and the cell line revealed that the lymphoma was negative both for EBNA and EBV DNA, and possessed t(8;14) (q24;q32) in chromosome analysis. Surface antigens were positive for HLA-DR, CD19 and CD20, but negative for CD10. The lymphoma also expressed a monoclonal pattern (IgG, kappa type) both of surface immunoglobulin and cytoplasmic immunoglobulin. Thus, the lymphoma was originated from mature B-lymphocyte. We analysed clinicopathological findings of 216 patients who were reported as Burkitt's lymphoma in Japan. Of 35 cases examined for cell EBNA, 7 (20%) were positive for EBNA. Of 86 cases tested for surface immunoglobulin of tumor cells, 67 expressed IgM alone and 10 IgG alone on tumor cells. Cytoplasmic immunoglobulin of tumor cells was positive in 61% of patients. Of 11 cases positive for cytoplasmic immunoglobulin, IgM was detected in 8 patients and IgG only in our patient.

Burkitt Lymphoma↗
PubMed1991

[Zinc concentration in the central nervous system in a case of multiple sclerosis--comparison with other neurological diseases].

The possible role of trace elements in a pathogenesis of central nervous system (CNS) on degenerative and demyelinating diseases has been suggested. Simultaneous measurements of Zinc (Zn) and iron (Fe) concentration in CNS were undertaken by neutron activation analysis in CNS tissues: a patient with multiple sclerosis (MS), five patients with amyotrophic lateral sclerosis (ALS), five with spinocerebellar degeneration (SCD), and five with cerebral infarction (CVD) in non-invasive area of CNS as control. Although Zn and Fe concentration were present in white matter and gray matter of CNS in each disease, 1) Zn concentration showed no special pattern in gray matter among four diseases, but decreased more in white matter of MS and ALS than that of CVD (p less than 0.05); 2) Fe concentration in gray matter of SCD increased more than that in CVD (p less than 0.05), but Fe concentration in white matter of CVD was increased more than that of ALS (p less than 0.05); 3) Fe concentration of CNS in a patient with MS was not notable except for high Fe concentration in caudate nucleus and globus pallidus. The demyelinated pathological area in CNS of MS showed a decrease in Zn level but no change in Fe level. These results indicate that low Zn concentration in CNS tissues of MS seemed to be responsible for CNS demyelination, but not for undernutrition due to poor conditions of a patient with MS. It seems that Zn might be one pathogenetic factor of MS, but the action of Fe in MS can not be ruled out.

Adult↗
PubMed1991

[Effects of 4-(o-benzylphenoxy)-N-methylbutylamine hydrochloride (bifemelane) on deposition of calcium and magnesium in the central nervous system tissues of rats maintained on low-calcium diets].

Since the reduction of calcium (Ca) intake leads Ca and magnesium (Mg) to mobilize from their bone pool and to deposit Ca in the soft tissues, especially in the central nervous system (CNS) tissues, the effects of 4-(o-benzylphenoxy)-N-methylbutylamine hydrochloride (bifemelane) on the deposition of Ca and Mg in the CNS tissues, heart, liver, kidney, muscle, abdominal aorta and bones were studied in rats maintained on low-Ca diets. Thirty-two male, 7-week-old Wistar rats, randomly divided into four groups, each consisting of 8 rats, were maintained for 90 days on the following diets: (A) standard, (B) standard with bifemelane (10 mg/100 g diet), (C) low-Ca, and (D) low-Ca with bifemelane (10 mg/100 g diet). Neither the A-B groups' nor the C-D groups' blood chemistry changed. However, Mg concentration in the cerebellum showed higher values in the B group than in the A group (p less than 0.05). And Mg concentration in pons, cerebellum, spinal cord, heart, liver and femur of the D group increased more than that of the C group (p less than 0.05-0.01), as determined by inductively coupled plasma emission spectrometry (ICP). On the other hand, Ca concentration in the liver was less in the D group than that of the C group (p less than 0.05). In general bifemelane had a tendency to decrease Ca deposition in the CNS and soft tissues of B and D groups. Bifemelane may possibly participate in activating the cerebral metabolism and in keeping an adequate Mg level in the CNS and soft tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Aluminum deposition in the central nervous system tissues of patients with Parkinson's disease].

Aluminum (Al) concentration in the 26 anatomic central nervous system (CNS) regions, liver, kidney, spleen and heart of our patients with Parkinson's disease, and five neurologically normal controls was measured by a non-destructive neutron activation analysis (NAA), in order to clarify the implication of Al on pathogenesis of Parkinson's disease. Al concentration in substantia nigra, caudate nucleus and globus pallidus increased in patients with Parkinson's disease more than that in controls (p less than 0.05). There was a significant difference in Al concentration of gray matter and basal ganglia in Parkinson's disease, compared with those of controls (p less than 0.01). It is likely that high Al deposition in pathological foci responsible for Parkinson's disease might be implicated in the pathogenesis of Parkinson's disease.

Aged↗
PubMed1991

Multicentre clinical trial of antirejection pulse therapy with deoxyspergualin in kidney transplant patients.

The present randomized comparative clinical trial was carried out to confirm the efficacy of a newly developed immunosuppressive drug, 15-deoxyspergualin (DSG), and also to find its optimal dose for antirejection pulse therapy. The study included 66 patients with rejection which had occurred within 6 months after renal transplantation. They were treated with DSG at 3, 5 or 7 mg/kg/day for 5 days. The overall percentage of efficacy was 73% and the percentage of efficacy was the highest in the 3-mg/kg group (82%). The incidence of adverse reaction tended to be dose-dependent. From these results, the optimal dose of DSG was judged to be 3-5 mg/kg/day for antirejection pulse therapy, and at doses in this range the percent efficacy could be expected to be 80% or more.

Graft Rejection↗
PubMed1991

[A case of small cell carcinoma of the lung responding well to oral etoposide therapy].

A case of recurrent small cell carcinoma of the lung, accompanied by intraperitoneal metastasis, was orally treated with etoposide (50 mg/day) for 3 consecutive weeks. Subjective symptoms such as abdominal pain began to improve one week after the start of treatment. After three weeks of treatment, these symptoms disappeared completely, and CT findings also improved. The serum NSE level, which was as high as 89.5 ng/ml before treatment, fell to 8.7 ng/ml after 3 weeks of treatment. The patient is now being followed at the outpatient clinic of our hospital. As adverse reactions to the drug, alopecia and leukopenia were observed. The leukopenia appeared in the third week of treatment, but the white blood cell count returned to normal soon after the drug was discontinued.

Administration, Oral↗
PubMed1991

[Transient focal abnormalities of MRI and angiographic neuroimaging in status epilepticus: case report].

We reported transient changes in computed tomography (CT), angiography and magnetic resonance imaging (MRI) scans in a patient with status epilepticus, referred to us with a tentative diagnosis of neoplasma based on CT, MRI and angiographic findings, MRI showed increased signal intensity, and CT showed decreased left hemisphere attenuation without enhancement. Two months later, resolution of these radiological and clinical abnormalities had been attained. The transient CT and MRI changes probably represented focal cerebral edema, developing during focal status epilepticus.

Adult↗
PubMed1991

Biocompatibility and capability of haemopurification systems: review and future development.

Past, present, and future developments of haemopurification systems are reviewed with respect to their biocompatibility and functional capability. The history of the polymethylmethacrylate (PMMA) membrane is introduced, along with the modifications aimed at removing beta 2-microglobulin (beta 2-M). A highly permeable PMMA membrane (BK) has the capability to adsorb beta 2-M. We have succeeded in finding material, thought to be beta 2-M, in transmission electron-microscopy of the membrane perfused with plasma from haemodialysis patients. As examples of the future development of haemopurification systems to remove targeted substances more specifically and efficiently, we consider hybridised bioartificial kidney containing proximal renal tubular cells fixed on collagen hollow fibre for degradation of beta 2-M to aminoacids, and an artificial reticuloendothelial system with polymyxin B immobilised fibre for removing endotoxin in blood. Targeting and specific removal with prepared biocompatible materials will open the way to the development of the second generation systems and close collaboration between medicine and industry is essential for realising these goals.

Biocompatible Materials↗
PubMed1991

[Evaluation of magnesium, calcium and aluminum deposition in bone in situ].

Current changing epidemiological pattern in the Western Pacific strongly suggests a contribution of the environmental factors to the pathogenetic process of amyotrophic lateral sclerosis (ALS). As a reflection of excess metals and a deficiency of minerals in soil and water samples in these foci, this study was designed experimentally to evaluate the concentration of calcium (Ca), magnesium (Mg) and aluminum (Al) in the bones of rats fed unbalanced mineral diets. Twenty-eight male Wistar rats, weighing 200 g, were fed either a standard diet, a low Ca diet, a low Ca-Mg diet, or a low Ca-Mg diet with high Al for 90 days. The composition of the diet/100 g consists of Ca 1250 mg, Mg 300 mg, Al 10 mg, Zn 4 mg in the standard diet; Ca 3 mg and Mg 2 mg in the low Ca-Mg diet; and Al 194 mg in the high Al diet, Al supplied as Al lactate. Ca, Mg and Al concentrations were determined by using inductively coupled plasma emission spectrometry (ICP) for bone and atomic absorption spectrometry for serum. Serum Ca levels in the groups fed unbalanced mineral diets were lower than those in the group fed standard diet. Serum Mg levels were markedly decreased in the groups fed low Ca-Mg diet and low Ca-Mg plus high Al diet, compared with those in the groups fed standard diet and low Ca diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Aluminum↗