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Biomedical subjects

Y Ono

Publications and source records attributed to Y Ono.

At least 1,009 records · Page 56Linked to original sources

[Head injury].

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Brain Concussion↗

[Assessment of the exposure of pest control operators to organophosphorus pesticides. Organophosphorus pesticides in blood and alkyl phosphate metabolites in urine].

Pest control operators usually spray pesticides in small areas such as a kitchen in a restaurant and are exposed to various pesticides, especially those of the organophosphorus (OP) type. In order to evaluate their occupational exposure to OP pesticides during the work, OP pesticides in blood and alkyl phosphate metabolites in urine of these operators were analyzed and the relationship between pesticide exposure and analytical results were studied. OP pesticides in blood were analyzed by gas chromatography with flame photometric detector (FPD-GC) after separation of phospholipid in blood with silicagel column chromatography. OP pesticides were not detected in any blood samples (the limit of detection was 1 ng/ml). Dimethylphosphate (DMP) and dimethylthiophosphate (DMTP), being urinary metabolites of OP pesticides, were analyzed by FPD-GC after benzyl derivatization. This method eliminated interfering peaks in gas chromatograms. The ratio of two isomeric derivatives of DMTP was found to be constant. Both DMP and DMTP of the exposed group were significantly higher than those of the non-exposed group, DMP being higher than DMTP. The ratio of DMP to DMTP in the fenitrothion-dichlorvos-exposed group was significantly higher than that in the fenitrothion-exposed group. It was considered that the ratio might reflect a result of pesticide exposure. The urinary metabolites of OP pesticides tended to become lower with the lapse of time since the last exposure. However, small amounts were detected in a few samples even 5 days after the last exposure.

Adult↗

[Vibration hazards in quarry workers].

Vibration hazards were surveyed in a population of quarry workers using chipping hammers and to a lesser extent, rock drills. Sixty-nine male quarry workers, aged 49.1 +/- 8.7 and exposed to vibration for 16.4 +/- 5.1 years, were surveyed in 1981-82. They were exposed to vibration for about 2-4 hours per days, mainly under a piece-work pay system. They had a high prevalence of Raynaud's phenomenon (36.2%) and numbness in upper extremities (53.6%). It is considered that the high prevalence was mainly due to large vibration levels in chipping hammers and rock drills and long daily exposure time. The attacks of Raynaud's phenomenon were found predominantly in the left hand, which held chisels, whereas the restriction of motion in the elbow was predominantly in the right arm which pushed chipping hammers. The same 49 male quarry workers in this population were also surveyed in 1976-77 and the prevalence of their complaints between 1976-77 and 1981-82 was compared. The prevalence of Raynaud's phenomenon was the same, but the frequency of the attacks increased between the two periods. The prevalence of other complaints such as numbness, pain and chills in the upper extremities also increased. Between 1976-77 and 1981-82, the prevalence of Raynaud's phenomenon, numbness, and pain in the upper extremities increased in the population of quarriers exposed to vibration for above 2.6 hours per day and 200 days per year, or 600 hours per year. On the other hand, the prevalence of these complaints mostly decreased in the population of quarriers with less exposure.

Adult↗

[Diagnosis of myocardial ischemia in Kawasaki disease: thallium-201 myocardial imagings at rest, with exercise and with dipyridamole administration].

Thallium-201 myocardial imaging was performed at rest in 131 children with coronary arterial lesions due to Kawasaki disease. The coronary arterial lesions were assessed by selective coronary angiography within a few days of the isotope study. Twenty-one children had occlusive lesions, and segmental stenotic lesions were seen in 16 children. Perfusion defects of the myocardial images were detected in nine of the former and in three of the latter. The locations of the perfusion defects coincided with the perfusion areas of the affected vessels on coronary angiography. Twelve patients with initial perfusion defects at rest had a follow-up study and the defects disappeared in five. These patients had re-establishment of coronary blood flow in the initially affected areas by either development of collateral vessels or recanalization. Myocardial imaging with exercise was performed in 27 patients including four with coronary arterial occlusion and two with segmental stenosis on coronary angiography. All with coronary artery lesions showed perfusion defects on the imaging with exercise, while the resting study showed the defects only in one patient, in whom more extensive perfusion defects were observed after exercise. Myocardial imaging following intravenous injection of dipyridamole was carried out in 43 patients. Perfusion defects after the injection were noted in 15 of 17 patients with coronary occlusion and in nine of 13 patients with segmental stenosis. In four patients with perfusion defects at rest, additional or more extensive defects were revealed by this drug in the areas of additional coronary arterial involvements. In 20 patients with perfusion defects only after dipyridamole injection, the perfusion defects coincided with the angiographic findings very well. A perfusion defect was documented following dipyridamole injection in one exceptional patient who had no stenotic lesions, but had three giant coronary aneurysms of the right coronary artery. Thus the dilated coronary lesions seemed to give a perfusion defect. In some of the patients whose perfusion defects disappeared at rest on a follow-up study, the defects were disclosed by exercise and/or dipyridamole administration. Thus, thallium-201 myocardial imagings combining resting and exercise or dipyridamole studies were valuable for the detection and assessment of coronary arterial lesions of Kawasaki disease.

Adolescent↗

[Thallium-201 myocardial imaging in patients with congenital heart disease following open-heart surgery].

Thallium-201 myocardial imaging was performed for 77 patients with congenital heart disease to evaluate myocardial damage following open-heart surgery. There were 23 patients with ventricular septal defects, 33 with tetralogy of Fallot, 12 with atrial septal defects, and nine with other diseases. The imaging results were compared with the angiographic and electrocardiographic findings. Patchy perfusion defects or images of poor thallium uptake were noted in five of 77 patients, among whom four had accompanying serious ventricular arrhythmias. This suggested a close correlation of the post-operative ventricular arrhythmias with myocardial damage. For 20 of 77 patients, vents were inserted through the left ventricle, and for the remaining 57 through the left atrium. Perfusion defects were found at the apex in three, and left ventriculography showed a paradoxical motion of the apex in five in patients whose vents were inserted through the left ventricle. Sensitivity and specificity in detecting myocardial damage of the apex were 60% and 98%, respectively. In one case, myocardial infarction was demonstrated immediately after the repair of the ventricular septal defect. Myocardial imaging was useful in evaluating the infarcted area and for follow-up study. Thus, thallium-201 myocardial imaging was regarded useful for assessing myocardial damage following open-heart surgery in congenital heart disease patients.

Adolescent↗

Dental survey in Nigeria. Part I. Prevalence of dental caries in Nigeria.

A joint dental epidemiological survey was carried out in 1981 in the ancient city of Ile-Ife and its environs in the Federal Republic of Nigeria. The survey was made with the University of Ife, Ile-Ife, Oyo State, Nigeria, as the base. The occurrence of caries in 898 Nigerian school children of 509 urban and 389 rural children was compared with the occurrence of caries in the Japanese children. The results showed that the incidence of caries in the Nigerian school children was much lower than that of their Japanese counterpart. However, it is projected that with the increase in the consumption of sweet drinks and food in Nigeria, if superimposed on the existing poor oral hygiene, the incidence of caries will increase greatly.

Adolescent↗

Direct expression of hepatitis B surface antigen gene in E. coli.

A 809 bp Sau 3A - Hpa I fragment containing a complete HBsAg gene and fragments 744 bp Hinc II - Hpa I and 712 bp Xba I - Hpa I containing a truncated HBsAg gene lacking the sequence encoding the NH2-terminal hydrophobic domain were prepared from a composite plasmid pHBV933 containing the 3.2 kb Eco RI DNA fragment of the entire HBV/adw genome and inserted into an expression vector pTRP801 to give plasmids pTRP SS-6, pTRP SS-39, and pTRP SS-50, respectively. The growth of a recombinant having pTRP SS-6 was greatly inhibited and the transformant expressed a low level of HBsAg, which is reactive to human anti-HBsAg antibody. Interestingly, the growth of transformants harbouring pTRP SS-39 and pTRP SS-50 was not inhibited and these transformants expressed a considerable level of the HBsAg. Minicells harbouring pTRP SS-6, pTRP SS-39, and pTRP SS-50 formed specific polypeptides of about 24 K, 23 K, and 22 K daltons, respectively.

Antigen-Antibody Complex↗

Expression of human immunoglobulin E epsilon chain cDNA in E. coli.

Using the cDNA of human epsilon chain, three expression plasmids that code directly the constant portion of the epsilon chain (C epsilon 1-C epsilon 4, C epsilon 2-C epsilon 4 and C epsilon 3-C epsilon 4 domains) were constructed. These epsilon chain peptides were synthesized in E. coli under the control of the trp promoter-operator. The bacterially produced peptides have the antigenicity of human epsilon chain and gave the molecular weights equal to the values calculated from the amino acid sequence of the constructed plasmids.

Base Sequence↗

The complete nucleotide sequences of the cloned hepatitis B virus DNA; subtype adr and adw.

The complete nucleotide sequences of two different subtypes (adr and adw) of hepatitis B virus (HBV) DNA cloned in E. coli were determined. The sequence of the viral genome of the adr clone was 3188 nucleotides long, and that of the adw clone was 3200 nucleotides long. The adr and adw clones differed from the reported cloned ayw HBV DNA (3182 nucleotides long) in 11.2% and 10.0% of nucleotides, respectively. Heterogeneity of the HBV genome in the clones with the same subtype was observed.

Amino Acid Sequence↗

Molecular cloning and nucleotide sequencing of human immunoglobulin epsilon chain cDNA.

DNA complementary to mRNA of human immunoglobulin E heavy chain (epsilon chain) isolated and purified from U266 cells has been synthesized and inserted into the PstI site of pBR322 by G-C tailing. This recombinant plasmid was used to transform E. coli chi 1776 to screen 1445 tetracycline resistant colonies. Nine clones (pGETI - 9) containing cDNA coding for the human epsilon chain were recognized by colony hybridization and Southern blotting analysis with a nick-translated human IgE genome fragment. The nucleotide sequence of the longest cDNA contained in pGET2 was determined. The results indicate that the sequence of 1657 nucleotides codes for 494 amino acids covering a part of the variable region and all of the constant region of the human epsilon chain. Most of the amino acid sequence deduced from the nucleotide sequence is in substantial agreement with that reported. Furthermore a termination codon after the -COOH terminal amino acid marks the beginning of a 3' untranslated region of 125 nucleotides with a poly A tail. Taking this into account, the structure of the human epsilon chain mRNA, except a part of the 5' end, is conserved fairly well in the cDNA insert in pGET2.

Amino Acid Sequence↗

A study on biological monitoring of n-hexane exposure.

n-Hexane is one of the solvents widely used in industry and well known to be neurotoxic. Recently it was clearly revealed that n-hexane is metabolized in vivo and its metabolites are excreted in the urine. However, the relationship between the exposed dose of n-hexane and the metabolites in the urine has not yet been substantially determined. Therefore, in this investigation we intended to clarify the above relationship in order to establish its usefulness for biological monitoring of n-hexane exposure. The exposed dose was measured by means of a personal monitoring badge worn by workers in seven factories manufacturing vinyl sandals. The time-weighted average (TWA) concentration of n-hexane was 0.2-47.4 ppm. The n-hexane metabolites in the urine of 22 workers were measured with modified Perbellini's method [12] in the early morning (6:00-7:00 hrs) and at 17:00 hrs. 2,5-Dimethylfuran, 2,5-hexanedione and gamma-valerolactone were identified by gas chromatography and mass spectrometory. At 17:00 hrs the means +/- SD of the metabolites were 0.21 +/- 0.11 mg/l for 2,5-dimethylfuran, 1.13 +/- 0.71 mg/l for 2,5-hexanedione, and 2.04 +/- 2.31 mg/l for gamma-valerolactone. The metabolites were also found in the urine in the early morning. 2-Hexanol was not detected in the urine of any worker examined. A strong correlation between TWA concentration of n-hexane and 2,5-hexanedione in the urine was found at 17:00 hrs (r = 0.895, P less than 0.001). The results suggest that the urinary metabolites of n-hexane, especially 2,5-hexanedione, could be useful indicators for biological monitoring of n-hexane exposure. Furthermore the present study offers the advantage of a better estimate of n-hexane TWA.

Adolescent↗