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Biomedical subjects

E Yano

Publications and source records attributed to E Yano.

At least 73 records · Page 4Linked to original sources
PubMed1986

The in vitro genetic effects of fibrous erionite and crocidolite asbestos.

Epidemiologic evidence has recently identified an association between an endemic outbreak of pleural and peritoneal mesothelioma in the Urgup region of Turkey and exposure to zeolite fibres. This malignancy is usually associated with exposure to asbestos dusts whose mineralogical characteristics differ from those of zeolites. The present study further defines the in vitro biologic activity of erionite, a common zeolite fibre found in the Urgup region of Turkey. Both erionite and crocidolite asbestos fibres were clastogenic in synchronous Chinese hamster ovary (CHO) fibroblasts. Both fibres also altered CHO ploidy. Erionite, unlike crocidolite or Min-U-Sil quartz, caused a slight increase in sister chromatid exchanges in synchronous CHO cells. Neither erionite nor crocidolite was mutagenic in a human lymphoblastoid cell line. Erionite fibres thus produced in vitro cytogenic changes similar to those caused by asbestiform mineral dusts and, like asbestos fibres, did not induce mutations in human lymphoblastoid cells.

Aluminum Silicates↗
PubMed1985

Wetting characteristics and blood clotting on surfaces of copoly(gamma-Benzyl-L-glutamate, gamma-hydroxyethyl-L-glutamine).

The film surface of poly(gamma-benzyl-L-glutamate) (PBLG) was modified with 2-aminoethanol to enhance its hydrophilicity. Controlling the reaction conditions of PBLG and 2-aminoethanol, various types of copoly(gamma-benzyl-L-glutamate, gamma-hydroxyethyl-L-glutamine) film surfaces were obtained. Surface free energy (gamma sv), the dispersive component of gamma sv (gamma dsv), the nondispersive component of gamma sv (gamma psv), and the interfacial free energy of polymer surface with water (gamma sw), which were obtained by using the contact angle measurement and calculation method proposed by Andrade et al., were changed remarkably by the aminolysis. The gamma sv value increased after 2 h of aminolysis from 48.2 (PBLG) to 65.3 dyn/cm and gradually increased to around 70 dyn/cm after 12 h reaction. (gamma dsv) and (gamma psv) changed from 31.0 and 17.2 dyn/cm (PBLG) to 26.5 and 44.3 dyn/cm, respectively. These parameters of the material surfaces, modified over 12 h reaction, were found to be similar to those of the surfaces of canine aorta, vein, and human fibrin membrane. Blood clotting times on these polymer surfaces were comparatively longer than on siliconized glass surfaces.

Blood Coagulation↗
PubMed1985

In vitro biological effects of volcanic ash from Mount Sakurajima.

Mount Sakurajima in the south of the Kyushu Island of Japan erupts hundreds of times a year and continuously emits large amounts of ash. More than a million people live under this ash plume, and there is considerable concern about the possible effects of this on their health. We have studied the physicochemical characteristics and in vitro effects of airborne ash collected at 8 km from the crater. More than 30% of the ash was found to be SiO2 (w/w) with most of the particles within the respirable size range. The ash did not inhibit the colony formation of V79-4 cells and failed to activate complement or generate chemotactic factor activity in samples of fresh human serum. It was minimally active in causing the release of lysosomal enzymes from human neutrophile, and did not cause arachidonic acid release from macrophage-like cells. These results were in accord with our epidemiological study, in which very low prevalences of nonspecific respiratory disease were demonstrated even at the area with highest ash exposure.

Air Pollutants↗
PubMed1985

Hydroxyapatite associated arthritis in a patient undergoing chronic haemodialysis.

A patient with uraemia undergoing chronic haemodialysis developed a unilateral effusion of the elbow joint. The chalky-white synovial fluid obtained from the joint contained many crystals that were identified as hydroxyapatite by infrared spectroscopy. The joint effusion showed chemotactic activity for healthy human neutrophils. Chemotactic activity of the lipopolysaccharide(LPS)-activated patient's serum was low compared to that of pooled healthy human sera, but the patient's serum did not have the inhibitor for the chemotactic factor. These findings suggest that the production of chemotactic factor in this patient's serum was decreased. The possible combined effects of the uraemic state and crystal-induced inflammation on the chemotaxis of neutrophil leukocytes are discussed.

Arthritis↗
PubMed1984

Multiple ring enhancement in a case of acute reversible demyelinating disease in childhood suggestive of acute multiple sclerosis.

A 5-year-old Japanese boy was admitted to our hospital because of progressive visual disturbance and quadriplegia. Computed tomography (CT) revealed multiple low density areas in the cerebral white matter, and intravenous injection of contrast medium resulted in ring enhancement around these areas. Exploratory aspiration of one of the low density areas gave a xanthochromic, viscous fluid. Pathologic examination of the drained fluid demonstrated small pieces of brain tissue with necrotizing lesions surrounded by demyelinating areas. The patient has been followed up for 3 years with corticosteroid treatment, and marked improvement has been achieved both in neurological examination and CT findings. From these clinicopathological findings an acute form of multiple sclerosis (MS) in childhood was suspected.

Cerebrospinal Fluid↗
PubMed1984

Chemotactic factor generation by asbestos. Fibre type differences and the effects of leaching.

The generation of chemotactic factors in normal human serum by treatment with chrysotile and crocidolite asbestos was investigated using the Boyden chamber method. Both types of asbestos produced chemotactic activity but not to the same extent. The two fibre types also produced different levels of complement activation as measured by C3 conversion using two dimensional immunoelectrophoresis. While there was a simple correlation between fibre concentration and C3 conversion the production of chemotactic activity declined at high doses of chrysotile. Phosphate buffer treatment reduced the differences between fibre types. The possible role of these phenomena in asbestos-associated disease is discussed.

Asbestos↗
PubMed1983

A pilot study on the anticonvulsive effects of a thyrotropin-releasing hormone analog in intractable epilepsy.

In 1981, Inanaga et al reported on the efficacy of DN-1417 (a TRH analog) in the treatment of degenerative myoclonus epilepsy and other forms of intractable epilepsy. Following this report, we studied the efficacy and safety of DN-1417 treatment in 10 intractable epileptic children ranging in age from 6 months to 11 years (mean 4 years), including 7 with Lennox syndrome (LS), 2 with West syndrome (WS) and 1 with degenerative myoclonus epilepsy (DME). The daily dose was from 0.02 to 0.05 mg/kg, initially, and then was increased to 0.05 mg/kg. Complete control of seizures was achieved in 2 patients with LS, a 50% or greater decrease in seizure frequency was observed in one patient each with LS and DME and a less than 50% decrease in 1 with LS and 2 with WS. There was no change in 2 LS cases, and 1 LS case became worse. Activation of psychic activities, such as psychomotor activity, facial expression and motivation, was also noted in 7 of the 10 patients. Furthermore, improvement of motor function was noted in 5 patients. Electroencephalographic abnormalities improved in 2 completely seizure free patients with LS in which EEG ameliorated along with clinical seizure control.

Anticonvulsants↗
PubMed1982

Basilar artery occlusion in a case of Duchenne muscular dystrophy.

This is a report of a case of Duchenne muscular dystrophy (DMD), with multiple infarcts in the territories of the basilar artery. He developed abrupt vomiting and transient left hemiparesis at the age of 4 years. The episodes were seen 3 times between 4-year-1-month to 5-year-1-month old. Transaxial computerized tomography (CT) revealed multiple, well-defined but irregularly marginated areas of low density centered in the mid- and upper pons, right cerebral peduncle and thalamus. A right vertebral angiogram illustrated the narrowed basilar artery. The rectus femoris muscle was biopsied at the age of 4-year-1-month which showed marked variation in fiber size, myonecrosis with phagocytosis, central nuclei, and adipose and connective tissue proliferation, which were consistent with those seen in DMD. It remains unknown whether the basilar artery occlusion was an incidental event in this particular case or closely related to the disease process of DMD.

Biopsy↗
PubMed1982

Vacuolar myopathy with type 2 A fiber atrophy and type 2 B fiber deficiency. A case of childhood form acid alpha-1,4-glucosidase deficiency.

This report describes a female patient with childhood form of acid maltase deficiency who survived till fifteen years old. Although acid alpha-1,4-glucosidase was deficient in the liver, kidney, skeletal and cardiac muscles, neutral alpha-1,4-glucosidase was present in normal concentrations in those organs. On light microscopic examination, numerous intracytoplasmic vacuoles containing acid phosphatase positive granules and PAS positive materials were present in both type 1 and 2 A fibers, predominantly in the latter. The striking finding in the present case was a selective type 2 fiber atrophy with type 2 B fiber deficiency believed to result from type 2 motor neuron dysfunction in the spinal cord. Electron microscopic study revealed extensive glycogen particle accumulation, autophagic vacuoles and myelin figures in the muscle fibers.

Adolescent↗
PubMed1981

The mode of genetic transmission of gouty family with increased phosphoribosylpyrophosphate synthetase activity.

The mode of genetic transmission of gout and increased activity of phosphoribosylphrophosphate synthetase (PRPPS) was studied in one family. Among 15 members of Family F, two male members had gout and had PRPPS activity of erythrocyte lysates three times higher than normal subjects. Five female members had activity 2.5 times higher than normal. The difference between the activities of male and female affected members was statistically significant (P less than 0.05). To examine the genetic trait of this abnormal PRPPS, the incorporation of 3H-adenine into erythrocytes or lymphocytes was studied using autoradiography. The number of grains which show the uptake of labeled adenine into cells revealed a normal distribution pattern in two normal persons and in two male patients, and a mixed pattern of the two cell populations in two female affected members. These results suggested mosaicism in female members and X-linked dominant transmission of this trait. Thermal inactivation of PRPPS of an affected female was intermediate between that from a normal subject and that from the affected males. This result showed the heterogeneity of the PRPPS from the hemolysate of an affected female. The genotype of PRPPS on the X-chromosome was assumed and the lod score between PRPPS and Xg was also estimated. From these findings and electrophoretical study, it was suggested that the abnormal enzyme was a mutant enzyme transmitted in an X-linked dominant trait, and that the mutation occurred on the structural gene of the PRPPS.

Adenine↗
PubMed1981

Relationship between chemical structure and cytotoxicity of aliphatic amines examined by a microtiter system with cultured fibroblasts.

Cytotoxicity of aliphatic amines was examined by a microtiter system with human diploid fibroblasts in relation to chain length of the compounds. Regression curves of the minimum inhibitory concentration on the carbon number in the chain was derived and it was revealed that the type of the regression curve of monoamines differed from that of diamines. Chromatographic hydrophobic parameter (RM) was also derived from high-performance thin-layer chromatography, and the relation between Hansch's parabolic model and the regression curve determined by carbon number (n) was discussed. The concept of quantitative structure-toxicity relationship is applicable to find less hazardous industrial chemicals. For the analysis of the relationship, measurement of RM value lessens the difficulty for obtaining partition coefficients of compounds. In addition, a newly developed microtiter system is simple, rapid and less tedious for the evaluation of the toxicity of chemicals especially in terms of a preliminary screening test.

Amines↗
PubMed1979

Nonionic nucleic acid analogues. Synthesis and characterization of dideoxyribonucleoside methylphosphonates.

A series of dideoxyribonucleoside methylphosphonate analogues, dNpN and dNpNp, which contain a nonionic 3'--5' methylphosphonyl internucleoside linkage were prepared. The two diastereoisomers, designated isomers 1 and 2, of each dimer differ in configuration of the methylphosphonate group and were separated by column chromatography. The diastereoisomers of each dimer have different conformations in solution as shown by ultraviolet hypochromicity data and their circular dichroism spectra. For example, dApA isomer 1 is more highly stacked than isomer 2, although both isomers are less stacked than the dinucleoside monophosphate, dApA. The circular dichroism spectrum of isomer 1 is very similar to that of dApA, while the CD spectrum of isomer 2 shows a loss of molecular ellipticity, [theta], at 270 nm and a greatly diminished [theta] at 250 nm. These results suggest that the stacked bases of dApA isomer 1 tend to orient in an oblique manner, while those in isomer 2 tend to orient in a parallel manner. This interpretation is verified by the 1H NMR study of these dimers (L. S. Kan, D. M. Cheng, P. S. Miller, J. Yano, and P. O. P. Ts'o, unpublished experiments). Both diastereoisomers of dAaA form 2U:1A and 2T:1A complexes with poly(U) and poly(dT), respectively. The higher Tm (Tm of poly(U)--isomer 1, 15.4 degrees C; Tm of poly(U)--isomer 2, 19.8 degrees C; Tm of poly(dT)--isomer 1, 18.7 degrees C; Tm of poly(dT)--isomer 2, 18.4 degrees C) values of these complexes vs. those of the corresponding dApA--polynucleotide complexes (Tm of poly(U)--dApA, 7.0 degrees C; Tm of poly(dT)--DApA, 9.2 degrees C) result from decreased charge repulsion between the nonionic dimer backbone and the negatively charged polymer backbone. The difference in conformations between dApA isomer 1 and dApA isomer 2 is reflected in the Tm of the isomer 1-poly(U) complex which is 4.4 degrees C lower than that of the isomer 2-poly(U) complex. Since these nonionic oligonucleotide analogues are taken up by cells in culture, they show promise as molecular probes for the function and structure of nucleic acids inside living cells.

Circular Dichroism↗