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Biomedical subjects

H Maeda

Publications and source records attributed to H Maeda.

At least 1,297 records · Page 72Linked to original sources
PubMed1981

Unusual familial lipoprotein C-III associated with apolipoprotein C-III-O preponderance.

Among 256 consecutive subjects so far studied in our laboratory, we found one subject (a 63-year-old female) whose very low density lipoprotein (VLDL) and high density lipoprotein (HDL) contained unusually high amounts of apolipoprotein C-III-O among apolipoprotein C-III polymorphic forms. Identification of apolipoprotein C-III-O was achieved by a combination of basic polyacrylamide gel electrophoresis, isoelectric focusing and sialidase treatment of plasma apolipoproteins. This unusual lipoprotein was inherited by two of her four children without the manifestation of clinical symptoms. Triacylglycerols and cholesterol concentrations of VLDL, low density lipoprotein (LDL) and HDL fractions, and serum apolipoprotein C-III levels of the three subjects with apolipoprotein C-III-O were within the normal range, as estimated by rocket immunoelectrophoresis. Our results clearly demonstrated that the unusual lipoproteins with the preponderance of apolipoprotein C-III-O among apolipoprotein C-III polymorphic forms were genetically determined. These cases may be a new type of genetic lipoprotein disorder.

Adult↗
PubMed1981

Direct effects of carbon monoxide on cardiac function.

The direct effects of carbon monoxide (CO) on cardiac function were investigated in hemoglobin-free living rabbits treated with perfluorochemical blood substitutes. After exchange transfusion with a perfluorochemical emulsion, the erythrocyte count was below 10 X 10(4)/mm3 in each animal. Gas mixtures of oxygen with 5%, 10%, and 20% of CO or nitrogen were administered via a respirator. The results showed that the cardiac effects of CO and nitrogen were significantly different as regards changes in arterial pressure, pulse pressure, heart rate, and the product of heart rate and systolic arterial pressure in spite of the same oxygen tension in the inhaled gases. It was concluded that there was a direct effect of CO not mediated by hemoglobin.

Animals↗
PubMed1981

A pharmacokinetic simulation model for chemotherapy of brain tumor with an antitumor protein antibiotic, neocarzinostatin. Theoretical considerations behind a two-compartment model for continuous infusion via an internal carotid artery.

A pharmacokinetic two-compartment model for the treatment of brain tumors in man was simulated with the aid of a computer. The parameters necessary for the simulations such as inactivation rate constant, elimination rate constant, distribution volume, blood volume, cerebral blood flow, and cytotoxic drug concentration were either determined in this study or obtained from the literature. A proteinaceous antitumor antibiotic, neocarzinostatin (NCS), was utilized as a prototype drug because it has features making it advantageous in the treatment of brain tumor. In particular, NCS has an extremely short half-life in serum (t 1/2 less than or equal to 3 s), while it is relatively stable in the cerebrospinal fluid (CSF) (t 1/2 approximately 50 s). Therefore, the drug level in the cerebral compartment can be made adequately high with an appropriate infusion velocity into the cerebral compartment; however, it was possible to keep the plasma level of the drug much lower than the toxic level. Thus, few side-effects should result. In an in vitro study, NCS was found to exhibit its cytotoxicity to glioblastoma cells at a concentration as low as 0.005 microgram/ml. In contrast, the cytotoxicity was not apparent for the normal glia cells at 0.1 microgram/ml. The model being considered in this investigation is a two-compartment model, which consists of the cerebral compartment and the rest of the circulatory system of the body. In this case the drug is infused via an internal carotid artery. The results of pharmacokinetic simulation and dose regimens for NCs are presented, based on the effective concentration of the drug to glioblastoma cells in culture and the available pharmacological parameters.

Antibiotics, Antineoplastic↗
PubMed1981

A comparison of the effects of electrical stimulation of the lateral and ventromedial hypothalamus on the activity of neurons in the ventral tegmental area and substantia nigra.

Extracellular unit recordings were obtained from neurons in the ventral tegmental area (VTA), the substantia nigra, zona compacta (SNC) and zone reticulata (SNR) of adult female albino rats anaesthetized with urethane and chloral hydrate. Neurons were divided into two types based on their electrophysiological characteristics; Type I neurons had long duration action potentials (greater than 2.6 msec) and slow discharge rates and Type II neurons had shorter duration action potentials and a wider range of discharge rates. Both types of neurons were found in the VTA and SNC, but there were only Type II neurons in the SNR. The effects of single pulse stimuli delivered to the ipsilateral ventromedial (VMH) or lateral (LH) hypothalamic areas on activities of the two types of neurons were investigated. Only a small portion of neurons in the VTA and SNC responded to VMH stimulation, but in contrast a majority of the two types of neurons in the VTA and SNC responded to LH stimulation. Most neurons in the SNR did not respond to VMH and LH stimulation. Type iI neurons in the VTA and SNC were predominantly suppressed by LH stimulation with short onset latencies (less than 6 msec), indicating the possibility of monosynaptic mediation. However Type I neurons in the VTA and SNC were activated and suppressed and the onset latencies of these responses were relatively longer. The high proportion of neurons of VTA and SNC responding to electrical stimulation of LH is consistent with anatomical evidence. Suppression and activation of Type I neurons in VTA and SNC suggest that the LH exerts modulatory influences on these neurons of the midbrain.

Animals↗
PubMed1981

Fluorescence polarization with FDA in leukaemic cells: a clear difference between myelogenous and lymphocytic origins.

Intracellular fluorescence polarization (IFP) values of normal human lymphocytes and leukaemic cells from newly diagnosed patients were determined from fluorescence polarization using fluorescein diacetate (FDA). Thirty healthy donors and 40 patients with various types of leukaemia (20 myelogenous and 20 lymphocytic) were included in the present studies. The result was that myeloid cells had about twice the polarization value of lymphocytic cells. The use of FDA for the determination of IFP appears to be useful for differential diagnosis, at least between acute myelogenous and lymphocytic leukaemias. These 2 types of leukaemia also showed a pronounced difference in fluorescence intensity when treated with FDA, perhaps owing to a difference in uptake velocity. The previously described membrane microviscosity using 1,6-diphenyl-1,3,5-hexatriene (DPH), however, did not show such a difference between these 2 leukaemias. The fluorescein-binding protein(s) was also investigated in order to clarify its effect on IFP, but there seemed little evidence for the existence of any such dyebinding protein(s). The advantages of the present method, using FDA, reside in its simplicity, rapidity and considerable sensitivity, requiring a small sample of blood usually less than 5 ml.

Adolescent↗
PubMed1981

Circumscribed myxoedema of lichen myxoedematosus as a sign of faulty formation of the proteoglycan macromolecule.

Using a new method devised by our laboratory, the ultrastructure of dermal glycosaminoglycan in an involved area of lichen myxoedematosus was examined. Although histochemical and biochemical studies have indicated simply an accumulated deposition of hyaluronic acid in the lesion, the glycosaminoglycan ultrastructure within it was distinctly different from that in normal skin. The glycosaminoglycan structure of normal skin was similar to the proteoglycan aggregate model described by Rosenberg (1975). As confirmed by the enzymatic digestion procedure, it represents the ultrastructure of hyaluronic acid bound to glycosaminoglycans such as dermatan sulphate or chondroitin sulphate. In contrast, hyaluronic acid filaments observed in lesions of lichen myxoedematosus contained no glycosaminoglycan subunits.

Adult↗
PubMed1981

Tuberculoid leprosy and HLA in Japanese.

HLA phenotypes of 54 patients with tuberculoid leprosy were compared with those of 167 healthy controls. Frequencies of HLA-A, -B and -C antigens did not differ significantly between the leprosy patients and the controls. However, an increase in the frequencies of DR1, DR2, DRW8 and MT1 antigens and a decrease in the frequencies of DR4 and MT3 antigens were observed in the leprosy patients. Statistical evidence was presented that MT1 antigens were primarily associated with tuberculoid leprosy in Japanese patients rather than DR2.

Adult↗
PubMed1981

Diffuse hemangiomatosis, coagulopathy and microangiopathic hemolytic anemia.

Described here is an autopsy case of a 30-year-old woman with systemic hemangiomatosis accompanied by coagulopathy and microangiopathic hemolytic anemia. She had hepato-splenomegaly, anemia, thrombocytopenia, prolonged prothrombin time and partial thromboplastin time, and fibrinogenopenia. A splenectomy was performed and a diffuse angioma of the spleen was found. Postmortem examination revealed cavernous hemangiomas and hemangioendotheliomatous lesions in the liver, bone marrow, intestine, and lymph nodes. Coagulation studies suggested that exacerbation of coagulopathy occurred due to Liniac (10MV X-ray) irradiation. Our observation raised the possibility that the irradiation might lead to chronic localized consumption coagulopathy, which was confined to the hemangioma, to acute disseminated types of intravascular coagulation.

Adult↗
PubMed1981

HLA DR4 and rheumatoid arthritis in Japanese people.

Eighty-eight Japanese patients with rheumatoid arthritis and 104 normal Japanese persons were typed for HLA A, B, C, and DR antigens. The frequency of HLA DR4 was 70.5% in patients compared with 46.1% in normal controls (P less than 0.001). However, a sex difference in the frequency of HLA DR4 in patients was noted. HLA DR4 was found in 80.6% of male patients, which was highly significant compared with controls (P less than 0.0005), while only a borderline increase of 60.5% was found in female patients (P less than 0.05). In addition, the frequency of HLA DR2 was remarkably low in male patients. These suggest the possible heterogeneity of rheumatoid arthritis in Japanese.

Adult↗
PubMed1981

Scintigraphic evaluation of regional pulmonary circulation and ventilation abnormalities in mitral valvular disease and congestive heart failure.

Regional pulmonary mean transit time, MTT (RV-Lung) was measured by radionuclide angiography using 99mTc-pertechnetate or 99mTc-HSA. In 8 normal subjects, MTT (RV-Lung) in upper (U) and lower (L) lung fields averaged 2.48 and 2.81 sec, respectively. In MS and CHF groups, MTT (RV-Lung) in L was markedly prolonged (5.04 and 5.10 sec, respectively) and after appropriate medical or surgical treatment, MTT in L markedly reduced. Pulmonary ventilation perfusion scintigraphy with 133Xe was performed in 18 patients with MS. Both Vu/L and Ou/L increased in accordance with the severity of disease, however, Vu/L had never exceeded unity. The estimation of regional MTT in the lung field is to be useful way in evaluating the severity of pulmonary circulatory disturbance in MS or in congestive heart failure.

Adolescent↗