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Biomedical subjects

Y Kusaka

Publications and source records attributed to Y Kusaka.

At least 91 records · Page 5Linked to original sources
PubMed1993

[Occupational diseases caused by exposure to sensitizing metals].

Diseases caused by occupational exposure to sensitizing metals including platinum (Pt), rhodium (Rh), nickel (Ni), chromium (Cr), cobalt (Co), gold (Au), mercury (Hg), zirconium (Zr) and beryllium (Be) are reviewed. Allergic reactions induced by the metals are described according to the classification by Coombs and Gell. Metals with unproven sensitizing potential are not discussed if reports on these are either very rare or devoid of convincing evidence for allergic involvement. The sensitizing metals are haptens which are not themselves able to act as antigens. There is evidence that combination of the metals with circulating or tissue protein gives rise to new antigens. An alternative hypothesis is that these metals interfere with the antigen recognition step of the immune response. Immunomodulatory effects or immunotoxicity of the metals may be also involved in metal-induced hypersensitivity. Occupational exposure to Pt, Rh, Ni, Cr, and Co causes allergic asthma via type I allergic reaction in which serum from affected individuals shows specific IgE antibodies against mental-human serum albumin conjugates. Some rheumatoid arthritis patients treated with gold salt therapy develop glomerulonephritis, thrombocytopenia, or agranulocytosis, which arise from type II and/or type III allergic reactions. Occupational exposure to mercury causes glomerulonephritis in which involvement of type III reaction is suggested. Type IV hypersensitivity reaction of the skin also takes place following exposure to the metals: allergic contact dermatitis is evoked by exposure to Ni, Cr, Co, Rh, and Hg; cutaneous granuloma is formed by contact with Zr and Be. Be is also a sensitizer of the lungs, resulting in granulomatous disease. Diagnosis of metal-induced allergic diseases is made on the basis of allergological tests with metal antigens including skin tests, radioallergosorbent test for specific antibody, lymphocyte transformation test, macrophage migration inhibition test, and provocation test. Atopy is a predisposing factor and smoking is a risk factor for developing metal-induced asthma. Evidence for genetic factors in the development of metal contact dermatitis is conflicting, although animal models implicate genetic factors in skin sensitization with some metals and respiratory sensitization with Be. Skin irritation, forearm injury, complication with atopic dermatitis and concomitant sensitization to other agents are determinants for prognosis of the dermatitis. Epidemiological reports of occupational diseases from allergic reactions to metals in industries are reviewed with respect to prevalence and allergic manifestations. There is a report on a clinical trial of hyposensitization with Pt in a platinum asthma patient. Predictive methods for evaluating sensitization potential of metals have been developed and new methods, which quantify potential more objectively, are sought.

Allergens↗
PubMed1993

[Effects of lifestyle on hematologic parameters; I. Analysis of hematologic data in association with smoking habit and age].

The effects of smoking and age on the results of hematologic tests were determined in a group of 429 healthy male workers. The results obtained were as follows: 1) The values of total leucocyte count (x10(9)/l), neutrophil count (x10(9)/l), lymphocyte count (x10(9)/l), monocyte count (x10(9)/l), hemoglobin (g/l), hematocrit, mean corpuscular volume (MCV; fl), mean corpuscular hemoglobin (MCH; pg), and mean corpuscular hemoglobin concentration (MCHC; g/dl) in current smokers were significantly higher than those in non-smokers. 2) Total leucocyte counts and neutrophil counts significantly increased with the number of cigarettes smoked per day in current smokers. 3) Total leucocyte counts, neutrophil counts, and lymphocyte counts significantly increased with Brinkman Index (B.I.) in current smokers. 4) The increase of age was significantly associated with the decrease of erythrocyte counts and the increase of MCV in both current smokers and non-smokers.

Adolescent↗
PubMed1992

MR microimaging of articular cartilage and contrast enhancement by manganese ions.

Saline solutions of manganese ions (Mn2+) were used as articular contrast agents in magnetic resonance microscopy (9.4 T) of cartilage of chicken femoral condyles and pig temporomandibular joints. The diffusion of Mn2+ from the articular surface into the cartilage matrix led to a strong contrast enhancement in the cartilage. The combination of the high spatial resolution and the contrast enhancement allowed the visualization of fine structures (tissue types) in the cartilage, which correlate with the tissue zones in histological sections stained with cationic dyes. We assume that the electrostatic interactions between the negatively charged groups of the proteoglycans and Mn2+ are most important for the mechanism of contrast enhancement. Hence, the different signal intensities of the various zones of cartilage indicate differences in density of proteoglycans. The intraarticular injection of the cationic contrast agent could improve the possibility of an early diagnosis of cartilage dysfunction and degeneration.

Animals↗
PubMed1992

Healthy lifestyles are associated with higher natural killer cell activity.

BACKGROUND: To investigate the association of individual lifestyle with immune response against tumors, we assayed peripheral blood lymphocytes of 62 healthy males ranging in age from 30 to 60 years for natural killer (NK) cell activity, which is the first line of defense against tumors, and for frequencies of NK cell subsets. METHODS: The NK cell activity was determined by 51Cr release assay, and NK cell subsets were counted using surface antigens (CD16, CD57) which recognize NK cell subgroups with different cytolytic potentials. Subjects were classified into groups reporting good, moderate, and poor lifestyles according to their responses on a questionnaire regarding eight health practices (tobacco smoking, alcohol consumption, hours of sleep, physical exercise, eating breakfast, balanced nutrition, hours of work habits, and mental stress). RESULTS: Individuals reporting good lifestyle habits were found to have the highest NK cell activity and it was significantly higher than the NK cell activity in those reporting poor lifestyle habits. Those reporting good health practices regarding smoking and physical exercise showed significantly higher NK cell activity at an effector-to-target-cell ratio of 40:1. CONCLUSIONS: The higher NK cell activity among individuals reporting good lifestyle practices may reflect an increase in the cytolytic potential of NK cell activity within the CD16+, CD57- subset.

Adult↗
PubMed1992

Primary culture of liver cancer tissues with or without transcatheter arterial embolization and establishment of a cell strain.

More epithelial-like cells are found in primary cultures of transcathetel arterial embolization (TAE)-untreated human liver cancer tissues than in those of TAE-treated tissues. A new cell strain, HUH-33, established from the former, grows slowly and is untransplantable into nude mice and secretes alpha-fetoprotein, albumin and some other tumor markers. Chromosome numbers are widely distributed. HUH-33 expresses hepatocyte type keratin and contains desmosome- or intermediate filament bundle-like structures.

Aged↗
PubMed1992

A pilot study to evaluate Japanese standard radiographs of pneumoconioses (1982) according to the ILO 1980 International Classification of Radiographs of Pneumoconioses.

The Japanese Classification of Radiographs of Pneumoconioses (JC) is characterized by its own standard films, including limit films which are defined to represent the upper limit of category 0 or the lower limit of category 1. This pilot study was aimed at evaluating the JC standard radiographs according to the ILO 1980 International Classification of Radiographs of Pneumoconioses (IC) in which some of the JC standards were read according to the IC by two groups of experienced British workers, four non-medically qualified (NM panel) and six medically qualified (MQ panel). The Japanese standard limit films, with rounded opacities of category 0/1 or 1/0, were classified by both groups as having lower categories in the IC than in the JC. With the standard mid-category films showing rounded or irregular opacities, the NM panel tended to produce higher categories than the MQ panel. From reading results by both panels, however, it may be said that the JC mid-category standards agree with the IC in terms of category.

Humans↗
PubMed1992

Determination of exposure to cobalt and nickel in the atmosphere in the hard metal industry.

Cobalt and nickel, matrices of hard metal, have been shown to be respiratory sensitizers. Airborne dust at hard metal-grinding worksites in a factor with a work-force of about 180 grinders was analysed for cobalt and nickel. The electron-microscopic X-ray microanalysis of airborne dust particles demonstrated that they had the same metallic components as hard metal products. Andersen sampling revealed that 66% of total dust was respirable (< 7 microns). Consecutive personal sampling for individuals indicated log-normally distributed concentrations of total dust and cobalt. Of the workers surveyed, 12% (16 out of 133) were exposed to cobalt at more than 50 micrograms m-3, while 1.5% (two out of 133) were exposed to nickel concentrations of more than 50 micrograms m-3. A correlation between cobalt exposure concentrations and nickel concentrations for individuals was significant and positive. Further improvement of the working environment is necessary because of the hazard caused by exposure to cobalt and nickel.

Air Pollutants, Occupational↗
PubMed1992

Specific IgE antibodies to nickel in workers with known reactivity to cobalt.

Twenty-one workers with hard metal asthma, including eight atopics, diagnosed on the basis of peak flow diaries and positive reaction to cobalt chloride (CoCl2) and/or nickel sulphate (NiSO4) in skin and provocation tests were studied for sensitization by detection of specific antibodies to nickel-conjugated human serum albumin (Ni-HSA), and nickel-conjugated exchange resin (Ni-resin). Their results were compared with those of sera obtained from control sera from 60 asthmatic patients and pair-matched asymptomatic control workers in the hard metal plant. In the RASTs (radioallergosorbent tests), sera from the same six subjects developed positive reactions both to Ni-HSA (RAST index greater than 2.0, P less than 0.01) and Ni-resin (RAST index greater than 2.0, P less than 0.01), while the counts measured for the others of the 15 subjects (RAST index less than 1.52) were about the same as those for control groups (RAST index less than 1.58). Subject HSA RAST and resin RAST results (378 +/- 52 c.p.m. in HSA RAST and 324 +/- 56 in the resin RAST) were about the same as those of the control sera (388 +/- 65 c.p.m. and 398 +/- 59 c.p.m., respectively). There was no difference in the prevalence of smoking habit and high IgE between Ni-RAST positive and negative subjects. However, subjects with simultaneous sensitivity to nickel and/or cobalt still developed asthmatic attacks following medications, while those without sensitivity to these metals were almost symptom free. The positive sera had simultaneous sensitivity to both cobalt and nickel, suggesting the presence in them of specific IgE antibodies to nickel playing some role in the aetiology of hard metal asthma.

Adult↗
PubMed1992

[Does lifestyle modulate natural killer cell activities?].

Natural killer (NK) cells play a crucial role in the defense against tumors. Peripheral blood monocytes are routinely assayed for the activity of NK cells by using a 4hr-51Cr release assay, and subsets of the NK cells are determined with monoclonal antibodies directed against surface phenotypes of the NK cells. We reviewed associations of demographic characteristics and individual lifestyles with the NK cells activities and the NK cell subpopulation frequencies. The age-dependence of NK cell activities has been a matter of controversy, although there are a number of cross-sectional survey reports suggesting an increase in NK cell activities with aging. The elevation of an NK subset bearing a phenotype of CD16+ (Leull+) has been reported to coincide with an increase in NK cell activities. Males are said to have higher NK cell activities than females. Smoking tobacco seems to reduce the NK cell activities and cessation of the smoking habit clearly increases the activities. With respect to alcohol consumption, no clear relevance to the NK cytolytic capability has been reported. Polyunsaturated fatty acid in food lowers the NK cell activities, while acute and subacute physical exercises significantly enhance the NK cell activities and the NK cell numbers in the peripheral blood, and a physical training protocol over a several-week period heightens the NK cell activities even among non-trained individuals. The association of the number of daily sleeping hours with the activities has not yet been elucidated. Stressful life events, daily hassles, mood, and a pattern of behavioural characteristics or personalities have been described as altering the NK cell activities and subpopulation frequencies.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1992

Combined effect of smoking habits and occupational exposure to hard metal on total IgE antibodies.

A survey was made within a population of workers (n = 706) exposed to hard metal dust (an alloy including cobalt), an agent known to cause occupational allergy. Twenty-seven (4 percent) of 733 workers were eliminated from consideration in this study because of atopic status identified prior to starting work in the plant. Using a Phadebas PRIST, the subjects' total IgE levels were determined and related to their smoking and exposure status. Nonexposed male smokers (n = 135) had a higher geometric mean IgE level (39.7 IU/ml) than did nonexposed subjects who had never smoked (33.1 IU/ml; n = 99); those with a higher Brinkman index (greater than 300), a smoking index obtained by multiplying the number of cigarettes per day by the duration of smoking in years, had significantly (p less than 0.05) decreased IgE levels. Although ex-smokers (n = 72) had a higher geometric mean IgE level (73.3 IU/ml) than did those who had never smoked, their serum IgE level declined with age since the time they quit smoking, regardless of their hard metal exposure status. Hard metal (cobalt) exposure may play a significant role as an adjuvant in the production of total IgE. A multivariate analysis demonstrated that hard metal exposure and a smoking habit together arithmetically (p less than 0.05) increased total IgE levels. These two factors may be preventable risk factors for occupational allergy in hard metal workers.

Adult↗
PubMed1992

[Assessment of occupational exposures to industrial hazardous substances. V. A proposed method for evaluating employee's exposure averages (8-h TWAs) using a single day measurement].

Daily exposure averages (8-h TWAs) to hazardous substances may vary considerably day to day, even though a worker is engaged in the same job. Previously we proposed a method to evaluate a long-term exposure condition with interday fluctuation using some exposure measurements. As it is assumed that 8-h TWAs are log-normally distributed, geometric standard deviation (sigma g) representing true interday fluctuation of 8-h TWAs should be estimated. If a single day's 8-h TWA of a worker is measured, sigma g of his own distribution of 8-h TWAs cannot be estimated. Therefore, to evaluate a long-term condition using a single day's 8-h TWA, representative sigma g in all industrial workplaces must be determined beforehand. To investigate sigma g observed in many industrial workplaces, two days' 8-h TWAs of each worker were measured in a week on 260 workers exposed to 19 hazardous substances. Sg2 (geometric standard deviation estimated by two samples) ranged from 1.00 to 8.22 with a median of 1.47 and a 90% upper limit of 2.47. Transforming Sg2 into sigma g, median and 90% upper limit of sigma g were 1.75 and 2.47, respectively. According to a classification scheme in the proposed method, exposure levels (I to III) were calculated using sigma g of 1.75 and 2.47. A long-term exposure condition to hazardous substances can be evaluated by comparing a single day's 8-h TWA with the exposure levels.

Environmental Monitoring↗
PubMed1992

Reversible lung lesions in rats due to short-term exposure to ultrafine cobalt particles.

Using an ultrasonic nebulizer, cobalt aerosols (MMAD = 0.76 microns, sigma g = 2.1) were generated from an aqueous suspension of ultrafine metallic cobalt particles (Uf-Co) with a primary diameter of 20 nm. Rats were exposed to Uf-Co aerosols at 2.72 +/- 0.44 mg/m3 for 5 hours (Exp. 1) or at 2.12 +/- 0.55 mg/m3 for 4 days at 5 hours/day (Exp. 2). Only minimum histopathological changes were observed in the lungs in Exp. 1. In Exp. 2, evidence of slight injury was noted, including focal hypertrophy or proliferation of the epithelium in the lower airways, damages of macrophages, intracellular edema of the type I alveolar epithelium, interstitial edema, and proliferation of the type II alveolar epithelium. A new finding in this study was the morphological transformation of some damaged type I cells to the juvenile form, which appeared to indicate the capability of self-repair of this cell type. The return to a juvenile form seemed to be a key response of type I cells during the early process of repair without cell division following non-lethal injury. Cobalt accumulated in the lungs after inhalation and was transferred rapidly to the blood. In conclusion, inhaled Uf-Co induced reversible pulmonary injury even after short-term exposure.

Administration, Inhalation↗
PubMed1991

Lymphocyte transformation test with nickel in hard metal asthma: another sensitizing component of hard metal.

To determine cell-mediated immunity to nickel, another matrix in hard metal besides cobalt, lymphocyte transformation tests (LTT) with nickel were carried out in seven hard metal asthma patients all of who had reacted to cobalt chloride in the bronchial provocation tests (BPT). Immunoallergic studies prior to the present study revealed that three of the seven generated a simultaneous positive reaction in the BPT with nickel and the allergosorbent test with nickel-conjugated human serum albumin (Ni-HSA). A stimulation index in LTT indicating a positive response was defined on the basis of results from the studies in the controls. Data revealed that two of the three who showed a combination of positive bronchial and immunological reactions with nickel had a positive LTT with nickel. In the other five, peripheral lymphocytes did not proliferate in response to nickel. Thus it is suggested that cell-mediated immunity to nickel as well as cobalt is implicated in some cases associated with hard metal asthma.

Asthma↗
PubMed1990

Alveolitis caused by exposure to coal mine dusts: production of interleukin-1 and immunomodulation by bronchoalveolar leukocytes.

Two kinds of coal mine dust, low rank with high quartz (bituminous) and high rank with low quartz (anthracite), were assayed for ability to induce alveolitis and to stimulate interleukin-1 release from normal alveolar macrophages in vitro. Dust-elicited bronchoalveolar leukocytes were also assessed for their effects on macrophage-depleted splenocyte mitogenesis and their ability to produce interleukin-1. Quartz and titanium dioxide were used for comparison as toxic and inert dusts, respectively. Both coal mine dusts caused substantial release of interleukin-1 from normal alveolar macrophages in vitro and the levels were higher than those caused by quartz. Bituminous coal mine dust provoked acute but rapidly subsiding macrophage/neutrophil alveolitis which was greater than that provoked by titanium dioxide; anthracite caused less alveolitis than titanium dioxide and quartz caused large scale, persistent alveolitis. Whole bronchoalveolar leukocytes, including polymorphonuclear neutrophils, elicited by exposure to dust, were less inhibitory to lymphocyte mitogenesis than normal alveolar macrophages and bituminous coal mine dust-induced neutrophils were augmentary to lymphocyte mitogenesis; macrophages from inflamed lungs were, on the whole, inhibitory to lymphocyte mitogenesis. Alveolar macrophages from bituminous coal mine dust- or titanium dioxide-exposed lungs showed increased ability to release interleukin-1 on stimulation in vitro. These findings suggest that bronchoalveolar leukocytes elicited by coal mine dust could modulate immunity by means of interleukin-1 release and enhancement of lymphocyte proliferation.

Animals↗
PubMed1990

Immunomodulation in mineral dust-exposed lungs: stimulatory effect and interleukin-1 release by neutrophils from quartz-elicited alveolitis.

Quartz deposition in the rat lung causes an intense and persistent neutrophil alveolitis leading to parenchymal fibrosis. Bronchoalveolar leucocytes (BAL) from quartz-exposed rat lungs were studied for their effects on splenic lymphocyte proliferation; titanium dioxide (TiO2) was used as a control, non-fibrogenic dust. Seven days after the intratracheal instillation of 1 mg of quartz or TiO2 suspended in phosphate-buffered saline (PBS), BAL were recovered by lavage; the effect of PBS alone was also studied. TiO2-elicited BAL (macrophages greater than 98%) inhibited splenocytes responding to suboptimal phytohaemagglutinin (PHA) more than PBS-elicited BAL (macrophages greater than 98%); the effect was dependent on the BAL:splenic lymphocyte ratio. Quartz-elicited whole BAL (macrophages 49%, neutrophils 51%), and an alveolar macrophage-enriched population with purity of 87% separated from it, were less inhibitory to splenocyte mitogenesis than PBS-elicited BAL. A neutrophil-enriched population, with a purity of 80%, markedly enhanced splenocyte response to PHA. In addition, whole quartz BAL and the macrophage-enriched population obtained from it enhanced the mitogenesis of T cell-enriched lymphocytes at a much lower BAL:lymphocyte ratio. The neutrophil-enriched quartz BAL enhanced mitogenesis substantially more than the whole or macrophage-enriched population from quartz-exposed lung. Supernatants from normal macrophages, PBS BAL, TiO2 BAL, quartz BAL and both alveolar macrophage and neutrophil-enriched quartz populations were assessed for interleukin-1 (IL-1) activity. Quartz-BAL, quartz macrophages and quartz neutrophils all produced significantly higher IL-1 levels than PBS BAL; the supernatants from quartz neutrophils, however, showed the highest IL-1 activity. These findings suggest that quartz-elicited bronchoalveolar leukocytes, especially neutrophils, enhance lymphocyte proliferation and that increased IL-1 secretion by these cells is likely to be the effector molecule involved. These findings have important implications for immune response in mineral dust-stimulated lung and for inflammatory lung disease in general.

Animals↗