The effects of weight gain after smoking cessation on atherogenic α1-antitrypsin-low-density lipoprotein.

Although cardiovascular risks decrease after quitting smoking, body weight often increases in the early period after smoking cessation. We have previously reported that the serum level of the α1-antitrypsin-low-density lipoprotein complex (AT-LDL)-an oxidatively modified low-density lipoprotein that accelerates atherosclerosis-is high in current smokers, and that the level rapidly decreases after smoking cessation. However, the effects of weight gain after smoking cessation on this cardiovascular marker are unknown. In 183 outpatients (134 males, 49 females) who had successfully quit smoking, serum AT-LDL levels were measured using an enzyme-linked immunosorbent assay. For all persons who had successfully quit smoking, body mass index (BMI) significantly increased 12 weeks after the first examination (p < 0.01). Among patients with a BMI increase smaller than the median, a significant decrease (p < 0.01) in serum AT-LDL values was found, but no significant changes in serum AT-LDL values were found in patients with a BMI increase greater than the median. The findings suggest that the decrease in serum AT-LDL levels after quitting smoking is influenced by weight gain after smoking cessation.

A novel genotoxicity assay of carbon nanotubes using functional macrophage receptor with collagenous structure (MARCO)-expressing chicken B lymphocytes.

Although carbon nanotubes (CNTs) are promising nanomaterials, their potential carcinogenicity is a major concern. We previously established a genetic method of analyzing genotoxicity of chemical compounds, where we evaluated their cytotoxic effect on the DT40 lymphoid cell line comparing DNA-repair-deficient isogenic clones with parental wild-type cells. However, application of our DT40 system for the cytotoxic and genotoxic evaluation of nanomaterials seemed to be difficult, because DT40 cells only poorly internalized nanoparticles. To solve this problem, we have constructed a chimeric gene encoding a trans-membrane receptor consisting of the 5' region of the transferrin receptor (TR) gene (to facilitate internalization of nanoparticles) and the 3' region of the macrophage receptor with collagenous structure (MARCO) gene (which is a receptor for environmental particles). We expressed the resulting MARCO-TR chimeric receptor on DNA-repair-proficient wild-type cells and mutants deficient in base excision repair (FEN1 (-/-)) and translesion DNA synthesis (REV3 (-/-)). We demonstrated that the chimera mediates uptake of particles such as fluorescence-tagged polystyrene particles and multi-walled carbon nanotubes (MWCNTs), with very poor uptake of those particles by DT40 cells not expressing the chimera. MWCNTs were cytotoxic and this effect was greater in FEN1 (-/-)and REV3 (-/-) cells than in wild-type cells. Furthermore, MWCNTs induced greater oxidative damage (measured as 8-OH-dG formation) and a larger number of mitotic chromosomal aberrations in repair-deficient cells compared to repair-proficient cells. Taken together, our novel assay system using the chimeric receptor-expressing DT40 cells provides a sensitive method to screen for genotoxicity of CNTs and possibly other nanomaterials.

Involvement of SLX4 in interstrand cross-link repair is regulated by the Fanconi anemia pathway.

Interstrand cross-links (ICLs) block replication and transcription and thus are highly cytotoxic. In higher eukaryotes, ICLs processing involves the Fanconi anemia (FA) pathway and homologous recombination. Stalled replication forks activate the eight-subunit FA core complex, which ubiquitylates FANCD2-FANCI. Once it is posttranslationally modified, this heterodimer recruits downstream members of the ICL repairosome, including the FAN1 nuclease. However, ICL processing has been shown to also involve MUS81-EME1 and XPF-ERCC1, nucleases known to interact with SLX4, a docking protein that also can bind another nuclease, SLX1. To investigate the role of SLX4 more closely, we disrupted the SLX4 gene in avian DT40 cells. SLX4 deficiency caused cell death associated with extensive chromosomal aberrations, including a significant fraction of isochromatid-type breaks, with sister chromatids broken at the same site. SLX4 thus appears to play an essential role in cell proliferation, probably by promoting the resolution of interchromatid homologous recombination intermediates. Because ubiquitylation plays a key role in the FA pathway, and because the N-terminal region of SLX4 contains a ubiquitin-binding zinc finger (UBZ) domain, we asked whether this domain is required for ICL processing. We found that SLX4(-/-) cells expressing UBZ-deficient SLX4 were selectively sensitive to ICL-inducing agents, and that the UBZ domain was required for interaction of SLX4 with ubiquitylated FANCD2 and for its recruitment to DNA-damage foci generated by ICL-inducing agents. Our findings thus suggest that ubiquitylated FANCD2 recruits SLX4 to DNA damage sites, where it mediates the resolution of recombination intermediates generated during the processing of ICLs.

[Factors related to sarcopenia in community-dwelling elderly subjects in Japan].

OBJECTIVES: This study aimed at determining the factors associated with sarcopenia, defined as low muscle mass and strength and low physical performance, in community-dwelling elderly subjects in Japan. METHODS: The subjects included 1,074 elderly, community-dwelling Japanese people aged 65 years or older. We measured appendicular muscle mass (AMM) by bioelectrical impedance analysis, grip strength, and usual walking speed. A low muscle mass was defined by the AMM index (AMI, weight [kg]/height [m(2)] as >2 standard deviations below the mean AMI for normal young subjects. The lowest quartile for grip strength and usual walking speed were classified as low muscle strength and low physical performance, respectively. "Sarcopenia" was characterized by a low muscle mass, combined with either a low muscle strength or low physical performance. Subjects without low muscle mass or strength and low physical performance were classified as "normal." Subjects were classified as being "intermediate" if they were neither "sarcopenic" nor "normal." Items in the questionnaire included residential status, past medical history, admission during the past year, smoking and drinking habits, leisure-time physical activity, health status, depression, masticatory ability, and dietary variety score. RESULTS: Sarcopenia was identified in 13.7% of men and 15.5% of women. Among men, a large proportion of subjects with sarcopenia had poor masticatory ability and a low dietary variety score compared with normal or intermediate subjects. Among women, a large proportion of the subjects with sarcopenia lived alone, had poor exercise habits, considered themselves to be unhealthy, and had poor masticatory ability compared with normal or intermediate subjects. A multiple logistic regression analysis showed that age and dietary variety in men and age and masticatory ability in women were associated with sarcopenia. CONCLUSION: The present study carried out in Japan showed that sarcopenia, assessed by muscle mass, muscle strength, and physical performance, was associated with age, dietary variety score (in men), and masticatory ability (in women).

Additive Effects of Solid Paraffins on Mechanical Properties of High-Density Polyethylene.

In this work, two types of solid paraffins (i.e., linear and branched) were added to high-density polyethylene (HDPE) to investigate their effects on the dynamic viscoelasticity and tensile properties of HDPE. The linear and branched paraffins exhibited high and low crystallizability, respectively. The spherulitic structure and crystalline lattice of HDPE are almost independent of the addition of these solid paraffins. The linear paraffin in the HDPE blends exhibited a melting point at 70 °C in addition to the melting point of HDPE, whereas the branched paraffins showed no melting point in the HDPE blend. Furthermore, the dynamic mechanical spectra of the HDPE/paraffin blends exhibited a novel relaxation between -50 °C and 0 °C, which was absent in HDPE. Adding linear paraffin toughened the stress-strain behavior of HDPE by forming crystallized domains in the HDPE matrix. In contrast, branched paraffins with lower crystallizability compared to linear paraffin softened the stress-strain behavior of HDPE by incorporating them into its amorphous layer. The mechanical properties of polyethylene-based polymeric materials were found to be controlled by selectively adding solid paraffins with different structural architectures and crystallinities.

Diastolic cardiac function is synonymous with long-axis systolic function: a novel concept in cardiac function.

AIMS: There has been recent speculation on the relationship between diastolic cardiac function and long-axis cardiac function. The goal of this study was to obtain conclusive evidence regarding the relationship between these parameters. METHODS: Echocardiography and cardiac magnetic resonance imaging were performed consecutively in 33 subjects. Longitudinal fractional shortening and fractional shortening of the left ventricular wall length were measured in each procedure and the relationships with diastolic cardiac function were assessed. RESULTS: Diastolic cardiac function and long-axis systolic function in each procedure were significantly correlated. Spearman coefficients for correlations between longitudinal fractional shortening measured echocardiographically and diastolic cardiac function parameters were 0.76 (P < 0.0001) for E/A, -0.77 (P < 0.0001) for E/e', 0.87 (P < 0.0001) for e', and 0.91 (P < 0.0001) for e'/a'. CONCLUSIONS: Long-axis cardiac function correlates well with diastolic cardiac function. e'/a' showed a strong correlation with longitudinal fractional shortening and is a good candidate for use as an index for assessment of long-axis cardiac function.

Toxicological aspects of cadmium and occupational health activities to prevent workplace exposure in Japan: A narrative review.

Chemicals are an essential part of modern manufacture processes. Their use must be managed with great attention in occupational settings to avoid serious detrimental effects to the health of employees. For example, cadmium compounds are indispensable for the production of nickel-cadmium rechargeable batteries or as chemical stabilizer in plastics. It is an exceptionally toxic heavy metal and personnel exposed to cadmium in the workplace meet with potential health risks that can lead to the development of kidney, skeletal and respiratory disorders. In consequence, proactive and systematical development of occupational hygiene and health activities are necessary to reduce chemical exposure to cadmium in the workplace. This review describes the known facts of cadmium toxicity, the biological effects of cadmium exposure, possible regulation measures to prevent occupational cadmium exposure in three industrial health management systems and discusses future cooperation programs in these systems, proactive safety activities and occupational safety and health management strategies.

[Comparison of diagnostic criteria for the metabolic syndrome among Japanese university faculty].

OBJECTIVES: Diagnostic criteria for the metabolic syndrome (Mets) in Japan have been set by the Medical Committee of the Japanese Association of Medical Sciences (Med), the National Health and Nutrition Examination Survey (Nat), specific health checkups (Ckup), and second medical examination by Worker's Accident Compensation Insurance System (Wor). The purpose of this study was to compare classification of the metabolic syndrome by different organizational criteria and to investigate underlying differences. METHODS: All faculty members of a university in Osaka, Japan, underwent mandatory health checkups in September 2008. The demographic distribution included 769 males (mean age, 49 +/- 12 years) and 415 females (mean age, 43 +/- 10 years). Using the Med, Nat, Ckup and Wor criteria, individuals were assessed for the MetS and pre-metabolic syndrome (pre-Mets), strongly suspected metabolic syndrome (S-Mets) and assumed pre-metabolic syndrome (A-pre-Mets), as well as a positive support level (PSL) and a motivational support level (MSL). All faculty members were categorized into a morbid group (Mets, S-Mets, PSL, and FB) or a pre-morbid group (pre-Mets, A-pre-Mets, and MSL) based on medical data and smoking habits. The incidence of morbid and pre-morbid individuals was compared across the four criteria and analyzed based on gender and age (under 40 and 40 or over). RESULTS: Male incidences for the morbid and pre-morbid classifications were 17% and 20% with Med, 9% and 23% with Nat, 27% and 14% with Ckup, and 1.4% and 0% with Wor. There were significant differences across criteria sets in both the morbid and pre-morbid groups, with significantly greater numbers of males than females, and higher prevalences in those aged 40 or over than in their younger counterparts. Males aged under 40 classified into the pre-morbid group comprised 18% in Med, 16% in Nat, and 13% in Ckup. CONCLUSION: The different disease incidences found between Med and Ckup data in males aged 40 or over might be attributed to varying criteria for blood glucose levels, while Wor data may be influenced by the higher level of blood pressure set as a criterion with this approach. It will be important to continuously validate currently established criteria to identify the actual prevalence of MetS in Japan. Furthermore, incorporation of waist circumference and BMI for females, and a positive approach for young males, may be critical for future developments.

[Objective assessment of walking in housebound elderly who are able to go out alone].

AIM: The aim of this study was to objectively assess the risk parameters associated with walking in housebound elderly. METHODS: The subjects were 622 community-dwelling elderly (210 men and 375 women: age 65-85) with independence in activities of daily living (ADL). We administered questionnaires pertaining to housebound factors and measured walking parameters, twice, in May 2008 and May 2009. Housebound status was defined as leaving the house no more than once a week, and non-housebound status as more than once every 2-3 days. We measured the following walking parameters: usual and maximum walking speed, timed up and go, obstacle-negotiating gait, stair-climbing, and number of daily steps. RESULTS: The overall prevalence of housebound status was 10.0% in men and 8.5% in women. No statistically significant differences were seen in the prevalence of housebound status between genders or age groups. In men, maximum walking speed, timed up and go, and daily steps were slower or less in housebound than in non-housebound subjects. In women, all walking parameters, except usual walking speed, were slower or less in housebound than in non-housebound subjects. Logistic regression analysis showed that obstacle-negotiating gait was a risk factor for men (odds ratio 2.49), and for women, all walking parameters, except walking at usual speed, were risk factors, with the highest odds ratio of 4.77 for obstacle-negotiating gait. A slower obstacle-negotiating gait was a risk factor for housebound status for both men and women. CONCLUSION: Compared with non-housebound subjects, housebound elderly with the ability to go out alone had a similar usual walking speed but a slower obstacle-negotiating gait.

Evaluation of epidemiological studies of intestinal bacteria that affected occurrence of colorectal cancer: studies of prevention of colorectal tumors by dairy products and lactic acid bacteria.

Enviromental factors have been consistently associated with colon cancer risk. In particular, consumption of Western-style diet including red meat is the most widely accepted etiologic risk factor. It has been reported that dietary factors change the proportion of intestinal flora, and it also affects the composition of fecal bile acids and the intestinal activity of some mutagens. In addition, it was suggested that modulating the composition of intestinal flora may reduce the occurrence of colorectal cancer. In this review, we present the clinical studies on the association between intestinal flora and the risk of colorectal cancer that have been carried out to date. The clinical studies of intestinal bacteria related to colorectal cancer risk have not shown consistent results so far, compared with the accomplishments of some basic studies. On the other hand, it was suggested in some clinical studies that lactic acid bacteria reduce the occurrence of colorectal cancer.

[Aging changes in muscle mass of Japanese].

AIM: The purpose of this study is To examine the influence of age on muscle mass in a Japanese population for health promotion. METHODS: Subjects were 4,003 community-dwelling Japanese men and women. We employed four-frequency bioelectrical impedance analysis to estimate upper and lower limbs, trunk and whole body muscle mass. RESULTS: Men showed significantly more muscle mass in all parts of the body compared to women. There was a curvilinear relationship between age and muscle mass in both men and women. For all parts of the body, the slope of the regression line between age and muscle mass was greater in men than women. The changes in muscle mass with advancing age were different in each part of the body. In the upper limbs, there was little change with advancing age in both men and women. In the lower limbs, the decrease in muscle mass began after two decades, with the reduction in this muscle mass the greatest of all parts of the body with advancing age. In the trunk, the slope of the regression line increased from the second to the fifth decade, after which the slope decreased. CONCLUSIONS: These findings indicated that lower limb muscle mass was the first to begin to decrease and also showed the greatest decrease. For health promotion, it was seen as important to maintain muscle mass from at least middle age, with particular emphasis on the lower limbs.

Effects of sodium monofluoroacetate on glucose, amino-acid, and fatty-acid metabolism and risk assessment of glucose supplementation.

Sodium monofluoroacetate (SMFA; also known as compound 1080) is a highly toxic chemical; therefore, accidental exposure and intentional misuse are of great concern. SMFA intoxication is reportedly caused by the inhibition of aconitase. However, the pathogenesis underlying SMFA intoxication is not clear. This study was conducted to elucidate the acute effects of SMFA on glucose, amino-acid, and fatty-acid metabolism and to assess glucose supplementation as a possible alleviator or aggravator in SMFA intoxication. Rats were assigned to three groups: SMFA+saline, SMFA+glucose, and control (i.e., no SMFA), and blood samples were analyzed at 3 hours after SMFA or saline (control) administration. Additional rats were used for the monitoring of blood-glucose and lactate concentrations for 10 hour- and 14-day survival rates. SMFA increased the serum-citrate, serum-pyruvate, and blood-lactate concentrations. However, despite significant increases in these parameters when SMFA was administered with glucose, the effects on pH values were small and the survival rate was not changed. SMFA also increased the serum concentrations of free fatty acids, branched-chain amino acids, ammonia, urea, and calcium. The presence of glucose enhanced or suppressed these metabolic changes. Amphibolic intermediates in the tricarboxylic acid cycle might be supplied through the catabolism of proteins in SMFA intoxication. We conclude that other factors, in addition to the accumulation of lactate, citrate, and pyruvate, may affect survival rates, and that SMFA induces imbalances in glucose, amino-acid, and, fatty-acid metabolism. All these changes are inter-related and may contribute to SMFA intoxication.

Implantable cardioverter defibrillator in maintenance hemodialysis patients with ventricular tachyarrhythmias: a single-center experience.

Patients with hemodialysis (HD) are at risk of death due to cardiac arrhythmias, worsening congestive heart failure (CHF), and noncardiac causes. This study reviews our experience with the use of implantable cardioverter defibrillators (ICDs) in patients with ventricular tachycardia who are under maintenance HD. We retrospectively reviewed 71 consecutive patients who underwent an ICD implantation in our hospital. There were 11 patients under maintenance HD and 60 patients without HD. The group of patients with HD (HD group) was compared with the patients without HD (control group). The mean follow-up period was 30+/-9 vs. 39+/-4 months in the HD group vs. the control group, respectively. Among these patients, 6 in the HD group and 26 in the control group received appropriate ICD therapies. There was no difference in appropriate ICD therapy, time to the first therapy, and electrical storm between the 2 groups. In the HD group, 1 patient underwent surgical removal of the ICD system due to infective endocarditis. There were 5 deaths in the HD group (4 from CHF) and 8 deaths in the control group (4 from CHF). There were no sudden cardiac deaths or arrhythmic deaths in both groups of patients during the follow-up period. However, the overall death rate was significantly higher in the HD group (P<0.01). In HD patients, ICD therapy prevented arrhythmic death, but their rate of nonarrhythmic adverse outcomes was high. This risk-benefit association should be considered before implantation of the device.

[Utility of color-changeable chewing gum to evaluate masticatory ability in community-dwelling elderly persons].

PURPOSE: The masticatory ability of community-dwelling elderly persons is often evaluated using subjective questionnaires. However, an objective evaluation would clearly be beneficial so that problems can be adequately addressed. The purpose of this study was to determine the utility of color-changeable chewing gum to evaluate masticatory ability in community-dwelling elderly persons. METHODS: We analyzed the reliability of the chewing gum for assessment of masticatory ability in 5 individuals who were examined on 5 occasions at 2 hour intervals. We also analyzed the validity of color-change of the chewing gum for assessment of masticatory ability by means of a four-part examination of 210 community-dwelling elderly persons. The four parts were as follows: evaluation of masticatory ability with the gum, determination of the number of residual teeth, measurement of maximum bite force, and a questionnaire in which participants were asked to assess their own masticatory ability. Color changes in the gum after chewing were measured with a color-reader and quantified with the a* color space defined by the Commission Internationale de l'Eclairage. A higher a* value indicates a higher degree of mastication. RESULTS: With respect to reliability, the coefficient of variation for the a* of the color-changeable chewing gum was 2.15-3.75%. There were no significant a* value differences between men and women in any age group. Decrease with age was significantly only in women. With respect to validity, the a* value of the color-changeable chewing gum had a significant positive correlation with the number of residual teeth and maximum bite force in both men and women. In addition, men and women who reported good masticatory ability in response to the questionnaire had significantly high a* values. CONCLUSION: We found the use of color-changeable chewing gum to be a highly reliable and valid method for evaluating masticatory ability. Our results indicate that this method could be useful for monitoring masticatory ability in the community-dwelling elderly.

Delayed pericarditis associated with an implantable cardioverter defibrillator implantation using an active-fixation atrial lead.

A 57-year-old man with nonischemic dilated cardiomyopathy and ventricular tachycardia underwent routine dual chamber implantable cardioverter defibrillator (ICD) implantation. An active-fixation atrial lead was positioned at the lateral wall of the right atrium. He subsequently developed chronic severe pericarditis. Histopathological findings of the pericardium showed mechanical stimulus localized pericarditis. This case demonstrates that contact of the screw of the active-fixation atrial lead with the pericardium may be a possible mechanism for pericarditis after pacemaker/ICD implantation.

[A cross-sectional study on the relationship between the Trail Making Test and mobility-related functions in community-dwelling elderly].

AIM: The Trail Making Test (TMT) has been studied in western countries as an indicator of executive function, but there are few data on the TMT in Japan. This study was conducted to assess the characteristics of TMT and to explore the effect of TMT on physical function among community-dwelling elderly Japanese to promote health in the aged. METHODS: Subjects were 175 individuals aged>or=65 years (57 men and 118 women). The TMT test which consists of two parts (part A and part B)was performed. 8 physical function items such as indicators of functional decline (usual walking speed, timed up-and-go (TUG), one-leg standing balance, and handgrip strength), and indicators of mobility (maximum walking speed, TUG with cup, stair-climbing, obstacle-negotiating gait) were measured. For this analysis, we used a difference score defined as TMT calculated as the difference between times (part B-part A=TMT). Data were analyzed by sex respectively. RESULTS: The median TMT value was 58.61 seconds in men and 65.67 seconds in women. TMT value increased with age and there was no difference between men and women in absolute values. multinomial logistic regression analysis showed that poor TMT was related to low tertiles of TUG, handgrip strength, MWS, TUG with cup, stair-climbing and obstacle-negotiating gait, and to intermediate tertile of MWS with adjustment for age and sex. CONCLUSION: TMT was significantly associated with mobility-related functions, suggesting that TMT, as the indicator of executive function, should be considered to be included in the test batteries for evaluating older people.

[Evaluation of the best indicator of muscle mass in community-dwelling elderly persons].

AIM: The purpose of this study was to determine the best way to indicate muscle mass of community-dwelling elderly men and women. METHODS: We recruited 398 elderly men and women (age range, 61-96, years) who use a community center and live in a metropolitan suburb. We measured appendicular and whole body muscle mass by using bioelectrical impedance analysis and analyzed our results in relation to indicators of physical function. We assessed muscle mass with no adjustment, adjustment by body mass, and adjustment by body height. RESULTS: In men, appendicular muscle mass adjusted by body mass correlated significantly with 10-m obstacle walking time, and whole body muscle mass adjusted by body mass correlated significantly with all indicators physical function except five chair stands and maximum walking speed. In women, appendicular and whole body muscle mass adjusted by body mass correlated significantly with all indicators of physical function. However, appendicular and whole body muscle mass adjusted by body height were unrelated to indicators of physical function. CONCLUSIONS: Only whole body muscle mass adjusted by body mass was related to physical function in both men and women. This finding suggests that whole body muscle mass adjusted by body mass is the best indicator of muscle mass in community-dwelling elderly persons.

Factors associated with good self-rated health of non-disabled elderly living alone in Japan: a cross-sectional study.

BACKGROUND: Self-rated health (SRH) is reported as a reliable predictor of disability and mortality in the aged population and has been studied worldwide to enhance the quality of life of the elderly. Nowadays, the elderly living alone, a particular population at great risk of suffering physical and mental health problems, is increasing rapidly in Japan and could potentially make up the majority of the aged population. However, few data are available pertaining to SRH of this population. Given the fact that sufficient healthcare is provided to the disabled elderly whereas there is little support for non-disabled elderly, we designed this population-based survey to investigate SRH of non-disabled elderly living alone and to identify the factors associated with good SRH with the purpose of aiding health promotion for the elderly. METHODS: A cross-sectional study was conducted in a metropolitan suburb in Japan. Questionnaires pertaining to SRH and physical conditions, lifestyle factors, psychological status, and social activities, were distributed in October 2005 to individuals aged > or = 65 years and living alone. Response rate was 75.1%. Among these respondents, a total of 600 male and 2587 female respondents were identified as non-disabled elderly living alone and became our subjects. Multivariate logistic regression was used to identify the factors associated with good SRH and sex-specific effect was tested by stepwise logistic regression. RESULTS: Good SRH was reported by 69.8% of men and 73.8% of women. Multivariate logistic regression analysis showed that good SRH correlated with, in odds ratio sequence, "can go out alone to distant places", no depression, no weight loss, absence of self-rated chronic disease, good chewing ability, and good visual ability in men; whereas with "can go out alone to distant places", absence of self-rated chronic disease, no weight loss, no depression, no risk of falling, independent IADL, good chewing ability, good visual ability, and social integration (attend) in women. CONCLUSION: For the non-disabled elderly living alone, sex-appropriate support should be considered by health promotion systems from the view point of SRH. Overall, the ability to go out alone to distant places is crucial to SRH of both men and women.

Strong acute toxicity, severe hepatic damage, renal injury and abnormal serum electrolytes after intravenous administration of cadmium fluoride in rats.

Cadmium fluoride (CdF) is commonly used as an insulator for ulta high speed mass telecommunications equipment, and there is a considerable risk that industrial workers will inhale CdF particles. Despite the possibility that acute exposure can cause harmful systemic effects, there are no studies to date that address the health consequences of acute CdF exposure. This study therefore aimed to determine the acute lethal dose of CdF and its effects on various target organs, including the liver and kidney. We also determined the effect of CdF on serum electrolytes and acid-base balance. The effective lethal dose was determined and dose-response study was conducted after intravenous administration of CdF in rats. The 24 h LD(50) of CdF was determined to be 3.29 mg/kg. The dose-response study used doses of 1.34, 2.67, 4.01 mg/kg CdF. Saline or sodium fluoride solution were used for controles. Severe hepatocellular injury was induced at doses greater than 2.67 mg/kg, as demonstrated by AST and ALT activities greater than 1,500 IU/l in rats injected with a dose of 4.01 mg/kg. Acute renal failure was induced at doses greater than 2.67 mg/kg. Decreased serum Ca, increased serum K and metabolic acidosis were induced at a dose of 4.01 mg/kg. Decreased serum Ca was caused by exposure to ionized F. CdF has the strongest lethal and hepatic toxicity among all Cd containing compounds.

Acute lethal toxicity, hyperkalemia associated with renal injury and hepatic damage after intravenous administration of cadmium nitrate in rats.

Cadmium nitrate Cd(NO(3))(2) (CdN) is commonly used in Ni-Cd battery factories. The possibility of accidental exposure to CdN is great. CdN is very soluble in water compared to other Cd compounds. Therefore, acute toxicity would be expected to be quick due to rapid absorption after exposure. However, the mechanisms of CdN toxicity have not been fully elucidated. We investigated the acute lethal toxicity and harmful systemic effects of acute exposure to large doses of CdN. The lethal dose and dose-response study of the liver and kidney were determined after intravenous administration of CdN in rats. The LD(50) of CdN was determined to be 5.5 mg/kg. Doses of 2.1, 4.2, 6.3 mg/kg were selected for the dose-response study. Liver injury was induced at doses greater than 4.2 mg/kg. Severe hepatic injury occurred in the 6.3 mg/kg group, which would have been caused by acute exposure to the high concentration of Cd that exceeded the critical concentration in hepatic tissue. A remarkable decrease in urine volume in the 6.3 mg/kg group indicated acute renal failure. A decrease in creatinine clearance suggested acute glomerular dysfunction at doses greater than 4.2 mg/kg. Increases in urinary N-acetyl-beta-D-glucosaminidase/creatinine, beta(2)-microglobulin and glucose in the 6.3 mg/kg group indicated proximal tubular injury. Secretion of K ion was also severely affected by proximal tubular injury and severe decreases in urine volume, and an increase in serum K ion was identified at doses greater than 4.2 mg/kg. Thus severe hyperkalemia might be associated with the cardiac-derived lethal toxicity of CdN.