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Biomedical subjects

T Kondo

Publications and source records attributed to T Kondo.

At least 973 records · Page 54Linked to original sources

Comparison of readability between liquid crystal displays and cathode-ray tubes.

Flat-panel displays, especially liquid crystal displays (LCDs), are almost universally used today. Do LCDs assure better readability than cathode-ray tubes (CRTs)? Two experiments were carried out to determine which type of display is better using a newly developed device. Four types of displays were tested; negative and positive CRTs, and LCDs with and without backlighting. Variables were the type of display, age, and gender. At first, analyses of readability using eye movements were conducted. Middle-aged subjects showed slower reading speed than young subjects. Then, experiments of pupillo-accommodative functions were carried out. Non-backlit LCDs reduced focusing speed among young subjects and reading performance in middle-aged subjects. Since middle-aged workers have more difficulties than young workers, they should have their vision properly corrected for VDT viewing, more appropriate displays and a more comfortable illuminance environment than young workers.

Adolescent↗

Do liquid crystal displays assure better readability than cathode-ray tubes?

Flat-panel displays, especially liquid crystal displays (LCDs), are now firmly established as important devices for information displays. But do LCDs assure better readability than cathode-ray tubes (CRTs)? We carried out an experiment using four types of displays: negative and positive CRTs, and LCDs with and without backlighting. A syllable-checking task using the Japanese katakana alphabet was conducted among fifteen healthy workers. They were divided into three groups; Group 1 had five young males aged 25 to 29, Group 2 was made up of five young females aged 18 to 24, and Group 3 consisted of five middle-aged workers who were 40 to 50 years old. We used four ambient light levels: 200 lx, 500 lx, 1250 lx without reflected glare, and 500 lx with reflected glare, on the display screens from behind. The illuminance of the glare was approximately 200 cd/m2. Multiple regression analysis showed that non-backlit LCDs reduced reading performance in middle-aged subjects significantly. Since middle-aged workers have more difficulties than young workers, they need more appropriate displays and a more comfortable illuminance environment than younger workers.

Adolescent↗

Nucleotide sequence of the Clostridium stercorarium xynA gene encoding xylanase A: identification of catalytic and cellulose binding domains.

The nucleotides of the xynA gene of Clostridium stercorarium were sequenced. The structural gene consists of an open reading frame of 1533 bp encoding 511 amino acids with an M(r) of 56,519. The signal peptide cleavage site was identified by comparison with the N-terminal amino acid sequence of the enzyme produced by a recombinant Escherichia coli. Xylanase A consists of a catalytic domain belonging to family G at the N-terminus and two direct repeats of about 90 amino acids with a short spacing at the C-terminus. Deletion analysis showed that the repeated sequences were responsible for binding the enzyme to Avicel and were not essential for catalytic activity. The catalytic domain of this enzyme is highly homologous to xylanase A of Clostridium acetobutylicum (identity: 69%) and xylanase B of Bacillus pumilus (identity: 64%).

Amino Acid Sequence↗

Distribution of T cell subsets in chicken lymphoid tissues.

The distributions of T cell subsets in chicken lymphoid tissues were investigated immunohistochemically using monoclonal antibodies (Lc-6, Lc-4) with specificity for chicken CD4 and CD8, respectively. In thymic tissues, CD8+ cells were found only in the cortex, while CD4+ cells were detected not only in the cortex but also in the medulla. The cortex just below the capsule demonstrated no immunoreactivity to either antibody. In the cecal tonsile, CD8+ cells were found restrictly in the subepithelial lamina propria. It was noted that the germinal centers were clearly surrounded with many CD4+ cells in the mid and deep portions of the lamina propria. In the spleen, clusters of CD8+ cells were observed only in the red pulp. Most lymphocytes in the periarteriolar lymphatic tissue and perivenous lymphatic tissue showed a CD4-positive reaction. No lymphocyte in the germinal centers reacted with these two monoclonal antibodies. No immunoreactivity for either CD8 or CD4 was detected anywhere else in the bone marrow or bursa of Fabricius. In the case of exposure to the protein antigen (alum-precipitated bovine serum albumin), CD4+ cells were demonstrated in some germinal centers, which were increased in size, while the areas expressing CD8 in the red pulp were decreased in size. These results suggest that the preferential distributions of T cell subsets are inherent in chicken lymphoid tissues.

Animals↗

[Musculoskeletal symptoms and working postures in pear and apple orchard workers].

Musculoskeletal symptoms in pear and apple orchard workers were studied in relation to working postures, particularly arm elevation and head extension. The same forty-six female workers were examined three times; in May while thinning pears, in June while bagging pears, and in July while bagging apples. Musculoskeletal symptoms in the neck and shoulders were predominant in thinning and bagging pears when compared with bagging apples. When thinning pears, there was a significantly higher prevalence of complaints of stiffness and pain in the neck and shoulders, pain in the upper and lower back, muscle tenderness in the shoulders and forearm, and decreased back muscle power. When bagging pears, there was a significant difference in complaints of stiffness and pain in the neck and shoulders, muscle tenderness in the shoulders, and pain in motion of the neck joint. Pear tasks require more arm elevation and head extension than apple tasks. The working postures of arm elevation and head extension were considered to be a dominant causative factor in shoulder-neck disorders of the workers examined. The low back pain from thinning pears may be related with continuous backward bending of the back associated with the thinning work.

Agriculture↗

An experimental study on the objective measurement of accommodative amplitude under binocular and natural viewing conditions.

A high resolution optometer makes it possible to measure changes in refractive power objectively using reflected light from the fundus of the eye. There are limitations in that the subject has to see the target monocularly through a hole in the instrument. In the present study, we attempted to measure the accommodation and pupillary response with a newly developed device as a means to measure these factors in both binocular and natural viewing conditions. We compared the subjective accommodative amplitude levels obtained from the near-point distance with those of objective accommodative amplitude obtained in earlier studies using a monocular internal target. The amplitude of accommodation of the cases with binocular, natural viewing conditions was approximately 0.7 D larger than with monocular, internal target gazing. In previous studies, the difference between the subjective amplitude of accommodation and the results of the objective measurements, had been reported to be approximately 2 D, and was explained by the depth of focus. However, the difference between the subjective and objective amplitude of accommodation under binocular, natural viewing was smaller than that between the subjective and objective measurements (under monocular internal target gazing) from previous studies. This leads us to believe that besides the depth of the focus, we should consider the fact that the advantageous conditions inherent in binocular, natural viewing may increase the amplitude of accommodation. In the measurement of accommodative amplitude, the use of objective measuring methods are not affected by the subjects' subjective judgement.

Accommodation, Ocular↗

Acute eosinophilic pneumonia evaluated with high-resolution computed tomography.

We describe two cases of acute eosinophilic pneumonia (AEP) presenting with high fever and hypoxia of acute onset with bilateral interstitial infiltrates on chest roentgenograms. Diagnosis was confirmed in each case by bronchoalveolar lavage and transbronchial lung biopsy in which the pathologic process was limited to the lung interstitium. High-resolution computed tomography (HRCT) of the thorax at the height of the disease process revealed peripheral ground-glass opacities along the bronchovascular bundles. Symptoms and radiologic abnormalities resolved spontaneously within two weeks. The HRCT-findings may reflect the pathologic process in AEP and the ground-glass opacities likely indicate spontaneous resolution without corticosteroid therapy.

Acute Disease↗

Analysis of various factors affecting vibration-induced white finger.

Forty-one stone quarriers were studied with regard to various factors affecting vibration-induced white finger (VWF), i. e., age, total operating time (TOT), body mass index (BMI), smoking, drinking, past history of diseases and sensitivity to cold in childhood. Subjects were asked about these factors by interview according to a questionnaire. TOT and BMI were significantly different between subjects with VWF (VWF group) and those without VWF (NON-VWF group). TOT was considered to be a great factor in stone quarriers. BMI was 21.6 (kg/m2) in VWF group against 24.0 (kg/m2) in NON-VWF group, which suggests that lean subjects may be susceptible to VWF. As for other factors such as age, smoking, drinking, past history of diseases and sensitivity to cold in childhood, our findings showed no significant difference between VWF group and NON-VWF group.

Body Mass Index↗

Free radical formation induced by ultrasound and its effects on strand breaks in DNA of cultured FM3A cells.

Recent sonochemical studies have revealed that active oxygen species are formed by pyrolysis of water molecules due to high temperature cavitation bubbles. When aqueous solutions of DNA were sonicated, single-strand breaks and double-strand breaks of DNA were observed. Formation of double-strand breaks due to mechanical effects of cavitation and formation of single-strand breaks mostly due to free radicals were indicated. The sonochemically generated radicals from DNA constituents due to H atom and OH radical reactions, and pyrolysis processes, were identified by spin trapping with 3,5-dibromo-2,6-dideuterio-4-nitrosobenzene sulfonate. When suspensions of mouse mammary carcinoma FM3A cells and aqueous solutions of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) were exposed to 1 MHz ultrasound in the presence of Ar, a good correlation between DMPO-OH formation and the cell killing induced by ultrasound were observed. Although single-strand breaks of DNA in the cells were observed at the maximum intensity of DMPO-OH formation and cell killing, double-strand breaks were not. Free radical formation by ultrasound in aqueous solutions and its relation to DNA strand breaks in vitro and in vivo are discussed.

Animals↗

Sonochemistry of acetone and acetonitrile in aqueous solutions. A spin trapping study.

The 50 kHz sonolysis of argon-saturated water-acetone and water-acetonitrile mixtures was studied by EPR and spin trapping with 3,5-dibromo-4-nitrosobenzenesulfonate over a wide range of solvent composition. For both systems a single maximum was observed for the spin adduct yield of methyl radicals and of the radicals formed by H-abstraction from acetone and acetonitrile. These results combined with previous studies of water-methanol and water-ethanol mixtures indicate that the greater the vapor pressure of the volatile organic component, the lower the concentration of organic solute at which the maximum radical yield occurs. Methyl radicals from acetone are formed by C-C bond scission in the collapsing argon bubbles. For acetonitrile, C-H bond scission at high temperature is followed by H-addition to the triple bond and the decomposition of this intermediate radical to form methyl radicals. Since Anbar has shown (Science 161, 1343, 1961) that sonoluminescence and acoustic cavitation occur during the impact of liquid water on water with linear velocities similar to those of collapsing ocean waves, the sonochemistry of nitriles is of interest to chemical evolution studies.

Acetone↗

Preparation of heat responding artificial cells.

Enzyme-loaded microcapsules were prepared and treated with dimyristoylphosphatidylcholine molecules so as to control the permeation of substrates through the microcapsule membranes. The activities of enclosed enzymes increased with increase in ambient temperature, but gave an abrupt change at around the phase transition temperature of the lipid. The experimental results indicate the possibility of making artificial cells which respond to the temperature change of the surrounding medium.

Capsules↗

Serological evidence of Coxiella burnetii infection in wild animals in Japan.

One hundred and thirty-four (26%) of 511 sera from 11 wild animal species in eight prefectures in Japan had antibody titers to Coxiella burnetii by the enzyme-linked immunosorbent assay. High prevalences were observed in Japanese black bears (Ursus thibetanus) (78%), Hokkaido deer (Cervus nippon yesoensis) (69%), Japanese hares (Lepus brachyurus) (63%), Japanese deer (Cervus nippon centralis) (56%), and to some extent in Japanese monkeys (Macaca fuscata) (28%). A low prevalence (13%) was observed in nutrias (Myocastor coypus). Japanese serows (Capricornis crispus), wild rats (Muroides sp.), raccoon dogs (Nyctereutes procyonoides viverrinus), wild pigs (Sus scrofa leucomystax), and masked palm civets (Paguma larvata) had no detectable antibodies to C. burnetii. Thus, six of 11 wild animal species in Japan were exposed to C. burnetii. Based on the high prevalences in some species, they may be a potential source of infection to both domestic animal and human populations.

Animals↗

Immortalization of normal human cells is a multistep process and a rate limiting step of neoplastic transformation of the cells.

Three normal human fibroblast strains were immortalized by treatment with either 4-nitroquinoline 1-oxide (SUSM-1 and OUMS-24F lines) or 60Co gamma rays (KMST-6 line). Immortalization of normal human cells with these agents required repeated treatments. Before immortalization, most of the cells treated with these mutagenic agents showed more or less chromosome aberrations, but immortalized cells appeared very rarely. This suggests that several mutational events are involved in the immortalization process itself. The immortalized cells showed polygonal or epithelial-like morphology, prominent numerical and structural abnormalities of chromosomes, requirement of serum growth factors for their growth, and no tumorigenicity. The immortalized KMST-6 and OUMS-24F were further transformed into neoplastic ones by the ras oncogene, but not by transfection with the mutant p53 gene. Normal human fibroblasts which are mortal were not immortalized nor neoplastically transformed with the ras oncogene or the mutant p53. These findings strongly indicate that the immortalization of human cells is prerequisite for neoplastic transformation of the cells.

4-Nitroquinoline-1-oxide↗

[A 50-year-old man with metamorphopsia and optic nerve swelling].

We report a 50-year-old male having metamorphopsia associated with retinal edema. He was well until one month prior to the present admission when he developed occipital headache and backache. Three weeks later, he noted a sudden onset of twisting of visual images. On admission, he was in no acute distress with well preserved general conditions. Only neurological abnormalities were bilateral papilledema, retinal edema and horizontal nystagmus with a rotatory component. Routine blood chemistries were unremarkable. The CSF contained 28 cells/cmm with 60% consisting of large atypical cells. Cranial CT scans revealed no mass, however, the magnified orbital CT showed bilateral swelling of the optic nerve. He was treated with ventriculoperitoneal shunt and Ommaya tube placement through which methotrexate, cytarabine and prednisolone were administered. He was also treated with systemic cisplatin, mitomycin-C and 5-fluorouracil. With these therapy, his headache, metamorphopsia and papilledema improved. He was discharged for out-patient follow-up, however, he had to admitted again because of progressive difficulty of gait and loss of appetite. On admission, he complained of severe backache, and his gait disturbance appeared to be in part due to his backache. A slight weakness was noted in all four limbs with loss of deep reflexes. Mentally he was alert and cranial nerves appeared intact without papilledema. But nuchal rigidity was noted. Cranial CT scan revealed attenuation of all the cortical sulci and marked diffuse low density changes in the cerebral white matter, and his chest film revealed a ring-shape shadow in his left lung field. He deteriorated progressively with terminal gastrointestinal hemorrhage. He expired three weeks after his second admission.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

[A 62-year-old man with multiple cranial nerve palsies on the right side and a pelvic mass].

We report a 62-year-old man with a pelvic mass, who developed multiple cranial nerve palsies on the right side. He was well until the summer of 1977 when he developed a numb sensation in the sacral region. In the next year, a huge tumor was found in the sacral area in another hospital. Most of the tumor was resected at that time. Post-operative course was uneventful. In July 1988, there was an onset of weakness in his legs, gait disturbance, and dysuria. Myelography at the above hospital revealed a complete block at the seventh thoracic level. He was treated by laminectomy and post-operative radiation. In June 1990, he developed a neuralgic pan in his right leg. Two months later, he noted diplopia, deafness in his right ear, and swallowing difficulty. He was admitted to our hospital for further work up on January 14th of 1991. On admission, he was afebrile. General physical examination revealed a 4 cm had mass in his right anterior chest attaching the rib. Gynecomastia was noted bilaterally. Liver was felt by 5 cms under the right hypochondrium. The edge of the liver was firm. On neurologic examination he was an alert and mentally sound man. His higher cerebral functions were intact. In the cranial nerves, complete palsy of the abducens nerve, mild nerve deafness, paresis of the soft palate, atrophy and weakness of the sternocleidomastoid and upper trapezium muscles, all on the right side, deviation of the tongue to the right, slurred speech, and dysphagia were observed. The neck was supple. He was able to walk with a support. Mild weakness was present in his right lower extremity. Both legs were spastic. No ataxia or involuntary movements were noted. Deep reflexes were symmetric and normally active. No sensory loss was observed. No meningeal signs were present. Pertinent laboratory findings included moderate anemia (Hb 8.8 g/dl), LDH 2,631 U/l, CRP 7.4 mg/dl. The CSF was under an increased pressure (OP 260 mmH2O) containing 2 lymphocytes/ml, 43 mg/dl of protein, and 49 mg/dl of glucose. Radiologic examinations revealed a destructive change in the sacrum, lytic lesions in the seventh thoracic spine and in the clivus.(ABSTRACT TRUNCATED AT 400 WORDS)

Cranial Nerve Diseases↗

The relationship of high-density lipoprotein cholesterol to obesity, drinking and smoking habits.

Subjects were a total of 726 Japanese male transport service workers between the ages of 35 and 50. They were analyzed for obesity and drinking or smoking habits in relation to their HDL-cholesterol level and total cholesterol concentration. The cases were 100 low HDL-cholesterol (less than 40 mg/dl) and 121 high total cholesterol (greater than 230 mg/dl) subjects. We used a multiple logistic regression analysis. As for abnormally high total cholesterol, it was determined that the odds ratios at 40, 45, and 50 years of age were 1.95, 2.23, and 2.65, respectively, when 35-year-olds were considered the baseline. Abnormally high total cholesterol showed an odds ratio of 0.27 among thin subjects with a Body Mass Index (BMI) less than 21.0, when subjects with a standard BMI were calculated as the baseline. With reference to low HDL-cholesterol, the odds ratio for lean subjects was 0.30 against those who had standard habitus, while subjects with a BMI of more than 25.1 had an odds ratio of more than double. Compared with nondrinkers, low HDL-cholesterol exhibited odds ratios of 0.16 and 0.23, respectively, for moderate and heavy drinkers. In cases of low HDL-cholesterol, the odds ratios for mild and heavy smokers were 1.91 and 2.27, respectively, versus nonsmokers.

Adult↗

[Forensic toxicological application of TOXI-LAB screening for biological specimens in autopsy cases and emergency cares].

Using the TOXI-LAB drug detection system, emergency toxicological screening was performed in autopsy cases and emergency cares. In 280 autopsy cases (male 182 cases 65%, female 98 cases 35%), drug positive cases were 28 cases of male (15%) and 24 cases of female (24%). The age groups which showed higher rate of drug positive cases were 10s-40s in male (approximately 20%) and 20s in female (67%). In the 238 cases of emergency care (male 129 cases 54%, female 104 cases 44%, unknown 5 cases 2%), drugs were positive in 29 cases of male (22%) and 32 cases of female (30%). The age groups which showed relatively higher rate of drug positive cases were 40s in male (64%), 20s (71%) and 30s (89%) in female. Forty-four different kinds of drugs were detected in TOXI-LAB positive cases, in which the psychotropic drugs and the sedative-hypnotic drugs amounted to approximately 70%. Methamphetamine and amphetamine, which were the main abused drugs showing a socially important problem, were detected in total 15 cases. TOXI-LAB was based on thin-layer chromatography (TLC); however, from the extraction to development, coloration and detection have been accelerated (about 50 min) and simplified. In order to perform the forensic toxicological practice in Japan, it becomes more useful that TOXI-LAB is used in autopsy cases and emergency cares, if the drugs, which have caused poisoning cares in Japan, are added to TOXI-LAB. The present study describes the advantage and problem of TOXI-LAB drug detection system through demonstrating the practical cases of autopsy cases and emergency cares.

Emergencies↗