Case studies of spinal deformities in ornamental koi, Cyprinus carpio L

This is a study of vertebral deformities in ornamental koi based on computed radiography and skeletons cleaned by dermestid beetles (Dermestes maculatus). All koi developed gradual onset of swimming abnormalities as adults. Extensive intervertebral osteophyte formation correlated with age of fish and was associated with hindquarter paresis in one koi. Vertebral compression and fusion were the most common spinal deformities occurring at multiple sites, similar to findings in other farmed fish. Site-specific spinal deformities were thought to develop due to differences in swimming behaviour and rates of vertebral growth. One koi had offspring with spinal deformities. Spinal deformities are significant problems in both European and Australian food fish hatcheries. The heritability of vertebral deformities in farmed fish is reportedly low unless there is concurrent poor husbandry or nutritional deficiencies. The specific aetiologies for vertebral deformities in koi in this study could not be ascertained. Current knowledge on spinal deformities in the better studied European food fish species suggests multifactorial aetiologies. Future research should include prospective longitudinal studies of larger numbers of koi from hatch and consideration of all potential risk factors such as husbandry, nutrition, temperature, photoperiod and genetics.

Abatement of fluorinated compounds using a 2.45GHz microwave plasma torch with a reverse vortex plasma reactor

Abatement of fluorinated compounds (FCs) used in semiconductor and display industries has received an attention due to the increasingly stricter regulation on their emission. We have developed a 2.45GHz microwave plasma torch with reverse vortex reactor (RVR). In order to design a reverse vortex plasma reactor, we calculated a volume fraction and temperature distribution of discharge gas and waste gas in RVR by ANSYS CFX of computational fluid dynamics (CFD) simulation code. Abatement experiments have been performed with respect to SF6, NF3 by varying plasma power and N2 flow rates, and FCs concentration. Detailed experiments were conducted on the abatement of NF3 and SF6 in terms of destruction and removal efficiency (DRE) using Fourier transform infrared (FTIR). The DRE of 99.9% for NF3 was achieved without an additive gas at the N2 flow rate of 150 liter per minute (L/min) by applying a microwave power of 6kW with RVR. Also, a DRE of SF6 was 99.99% at the N2 flow rate of 60 L/min using an applied microwave power of 6kW. The performance of reverse vortex reactor increased about 43% of NF3 and 29% of SF6 abatements results definition by decomposition energy per liter more than conventional vortex reactor.

Air pollution interacts with past episodes of bronchiolitis in the development of asthma

BACKGROUND

Exposure to ambient air pollution and bronchiolitis are risk factors for asthma. The aim of this study was to investigate the effect of air pollution on the development of asthma in children with past episodes of bronchiolitis.

METHODS

A prospective 2-year follow-up survey consisting of parental responses to the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, and allergy evaluations were conducted in 1743 children with a mean age of 6.8 years. Recent 5-year exposure to air pollution was estimated using a geographic information system.

RESULTS

Higher exposure to ozone was associated with airway hyper-responsiveness (PC20  ≤ 16 mg/ml) at enrollment (odds ratio [OR] = 1.60, 95% CI [confidence interval] = 1.13-2.27) and with new episodes of wheezing during the 2-year period (OR = 1.92, 95% CI = 0.96-3.83). Past episodes of bronchiolitis were associated with both current wheezing and physician-diagnosed asthma. When the two factors were combined, the prevalence of bronchial hyper-reactivity (OR = 2.96, 95% CI = 1.41-6.24) and new wheezing (OR = 4.17, 95% CI = 0.89-19.66) as well as current wheezing and physician-diagnosed asthma was even greater (P for trend <0.05 for all). In children with both risk factors, lung function was significantly decreased, with atopic children being particularly vulnerable.

CONCLUSION

In children, the interaction between air pollution and past episodes of bronchiolitis resulted in a greater prevalence of asthma and pointed to an association with bronchial hyper-reactivity and decreased lung function. These results suggest mechanisms underlying the development of asthma.

Association between urine cotinine levels, continuous performance test variables, and attention deficit hyperactivity disorder and learning disability symptoms in school-aged children

BACKGROUND

We examined the cross-sectional relationship between environmental tobacco smoke exposure, continuous performance test (CPT) measures, and attention deficit hyperactivity disorder (ADHD) or learning disability symptoms in school-aged children.

METHOD

In total, 989 children (526 boys, mean age 9.1 ± 0.7 years), recruited from five South Korean cities participated in this study. We used urine cotinine as a biomarker for environmental tobacco smoke exposure, and obtained the children's scores on a CPT. Parents completed the Korean versions of the ADHD rating scale-IV (ADHD-RS) and learning disability evaluation scale (LDES). Using generalized linear mixed model (GLMM), we assessed the associations between urine cotinine concentrations, neuropsychological variables, and symptoms of ADHD and learning disabilities. Additionally, we conducted structural equation models to explore the effects' pathways.

RESULTS

After adjusting for a range of relevant covariates, GLMM showed urinary cotinine levels were significantly and positively associated with CPT scores on omission errors, commission errors, response time, and response time variability, and with parent- and teacher-rated ADHD-RS scores. In addition, urine cotinine levels were negatively associated with LDES scores on spelling and mathematical calculations. The structural equation model revealed that CPT variables mediated the association between urine cotinine levels and parental reports of symptoms of ADHD and learning disabilities.

CONCLUSIONS

Our data indicate that environmental exposure to tobacco smoke is associated with ADHD and learning disabilities in children, and that impairments in attention and inhibitory control probably mediate the effect.

Cancer survival in Incheon, Republic of Korea, 1997-2001

The Incheon cancer registry was established in 1997. Cancer is not a notifiable disease, hence registration of cases is done by active methods. The registry contributed survival data for 42 cancer sites or types registered during 1997-2001. The follow-up information has been obtained predominantly by passive methods, with median follow-up ranging between 1-44 months for various cancers. The proportion with histologically verified diagnosis for different cancers ranged between 16-100%; death certificates only (DCOs) comprised 0-51%; 49-100% of total registered cases were included for the survival analysis. The top-ranking cancers on 5-year age-standardized relative survival rates were testis (98%), thyroid (90%), ureter (87%), adrenal gland (86%), nonmelanoma skin (83%), corpus uteri (82%), Hodgkin lymphoma (81%), breast and cervix (74%). Five-year relative survival by age group showed a decreasing trend with increasing age groups for cancers of the stomach, small intestine, colon, gall bladder, larynx, lung, breast, cervix and ovary, and was fluctuating for other cancers.

Hair follicle: a reliable source of recipient origin after allogeneic hematopoietic stem cell transplantation

Blood, buccal swab and hair follicles are among the most commonly used sources for forensic science, parentage testing and personal identification. A total of 29 patients who have had a sustained engraftment from 15 months to 21.5 years after allogeneic hematopoietic stem cell transplantation (HSCT) without rejection, relapse or chronic GVHD involving oral mucosa were enrolled for a chimerism study. PCR-amplified short tandem repeat analyses were conducted per patient every 3 months for at least three consecutive times. The results for blood were all donor type except one who had a mixed chimerism, 14.5 years after receiving a transplant for lymphoma. As for buccal swab, mixed chimerism ranging from 10 to 96% donor origin was noted for 28 recipients except the one who had mixed chimerism of blood and retained total recipient type. In contrast, hair follicles were 100% recipient type for the entire group. It is concluded that the hair follicle is devoid of adult stem cell plasticity and may serve as a reliable source of recipient's origin when pre-transplant DNA fingerprinting or reference DNA is not available for people who have successfully received allogeneic HSCT while in need of a personal identification.

Bilateral retrocaval ureters with IVC duplication

We report a rare case of bilateral retrocaval ureters associated with duplicated inferior renal cava. A 69-year-old woman was sent to our emergency room for abdominal pain. Multidetector computed tomogram with multiplanar reconstruction revealed duplicated inferior renal cavae and the bilateral ureters were positioned behind the duplicated inferior vena cava. To our knowledge, coexistence of bilateral retrocaval ureters and duplicated inferior renal cavae has not been reported in the literature.

Influence of maternal serum levels of vitamins C and E during the second trimester on birth weight and length

OBJECTIVE

It has been known that maternal oxidative stress during pregnancy plays an important role in fetal growth. However, the association between antioxidant vitamin levels and birth outcomes is not conclusive. We investigated the relationship between maternal serum levels of vitamins C and E during the second trimester and birth weight and length.

DESIGN

Prospective cohort study.

SETTING

Outpatient-clinic of obstetrics, Ewha Womans University Hospital, South Korea.

SUBJECTS AND METHODS

The study subjects were 239 healthy, pregnant women who visited an obstetric clinic for antenatal care, and their singleton live births, in Seoul, Korea, between August 2001 and March 2003. We measured the levels of vitamins C and E in maternal serum during the period 24-28 gestational weeks. Each woman was interviewed for dietary intake by trained interviewers during the second trimester.

RESULTS

The serum concentration of maternal vitamin C during the second trimester was significantly associated with birth weight and length in the group of full-term deliveries. An increase of 1 microg/ml in the serum vitamin C level increased the birth weight by 27.2 g and the birth length by 0.17 cm. When we considered the levels of vitamins C and E together in the relationship with birth weight and length, we found that the heaviest birth weight and the longest birth length belonged to the group of upper vitamin C/upper vitamin E. However, dietary intake estimated by 24-h recall method was not a predictor of the levels of serum vitamins C and E.

CONCLUSION

We found that maternal serum vitamin C levels during the second trimester were positively correlated with birth weight and length in full-term babies. We also found that birth weight and length were highest when the levels of both vitamins C and E were high. Our results indicate the importance of antioxidant nutrient balance for pregnant women who are exposed to various oxidants through food, drinking water, or inhaled air.

Exposure to air pollution during different gestational phases contributes to risks of low birth weight

BACKGROUND

Although there have been growing concerns about the adverse effects of air pollution on birth outcomes, little is known about which specific exposure times of specific pollutants contribute to low birth weight (LBW).

METHODS

We evaluated the relationships between LBW and air pollution exposure levels in Seoul, Korea. Using the air pollution data, we estimated the exposure during each trimester and also during each month of pregnancy on the basis of the gestational age and birth date of each newborn. Generalized additive logistic regression analyses were conducted considering infant sex, birth order, maternal age, parental education level, time trend, and gestational age.

RESULTS

The monthly analyses suggested that the risks for LBW tended to increase with carbon monoxide (CO) exposure between months 2-5 of pregnancy, with exposure to particles <10 micro m (PM(10)) in months 2 and 4, and for sulphur dioxide (SO(2)) and nitrogen dioxide (NO(2)) exposure between months 3-5.

CONCLUSIONS

This study suggests that exposure to CO, PM(10,) SO(2) and NO(2) during early to mid pregnancy contribute to risks for LBW.

Is air pollution a risk factor for low birth weight in Seoul?

Environmental factors contributing to reduced birth weight are of great concern because of the well-known relation of birth weight to infant mortality and adverse effects in later life. We examined the associations between air pollution exposures during pregnancy and low birth weight among all full-term births (gestational age 37-44 weeks) for a 2-year period (January 1996 through December 1997) in Seoul, South Korea. We evaluated these associations with a generalized additive logistic regression adjusting for gestational age, maternal age, parental educational level, parity, and infant sex. We used smoothing plots with generalized additive models to analyze the exposure-response relation for each air pollutant. The adjusted relative risk of low birth weight was 1.08 [95% confidence interval (CI) = 1.04-1.12] for each interquartile increase for carbon monoxide concentrations during the first trimester of pregnancy. The relative risks were 1.07 (95% CI = 1.03-1.11) for nitrogen dioxide, 1.06 (95% CI = 1.02-1.10) for sulfur dioxide, and 1.04 (95% CI = 1.00-1.08) for total suspended particles also for interquartile increase in exposure. Carbon monoxide, nitrogen dioxide, sulfur dioxide, and total suspended particle concentrations in the first trimester of pregnancy period are risk factors for low birth weight.

Helicobacter pylori-associated iron-deficiency anemia in adolescent female athletes

OBJECTIVE

The objective was to investigate the role of Helicobacter pylori infection in iron-deficiency anemia (IDA) of pubescent athletes.

STUDY DESIGN

Blood sampling and a questionnaire survey were performed on 440 regular high school students and 220 athletes of a physical education high school. Hemoglobin, serum iron, total iron-binding capacity, ferritin, and immunoglobulin G antibody to H. pylori were measured to compare the prevalence of IDA and H. pylori infection in the groups. Nutritional analysis and a questionnaire survey for socioeconomic status were undertaken to compare and control for other risk factors that might influence IDA and H. pylori infection in the groups. In those with IDA coexistent with H. pylori infection, we also determined whether IDA can be managed by H pylori eradication.

RESULTS

The prevalence rates of IDA, H pylori infection, and H. pylori -associated IDA in female athletes were higher than in the control group. The relative risk of IDA was 2.9 (95% CI, 1.5 to 5.6) for those with H. pylori infection. Athletes who exhibited H. pylori -associated IDA showed significant increases in hemoglobin, iron, and ferritin levels after H. pylori eradication. The subjects in the control group who were treated orally with iron alone showed no significant changes.

CONCLUSION

Adolescent female athletes may have development of H. pylori -associated IDA, which can be managed by H. pylori eradication.

Air pollution and daily mortality in seven major cities of Korea, 1991-1997

The relationship between ambient air pollution and daily mortality in seven major cities of Korea for the period 1991-1997 was examined. These cities account for half of the Korean population (about 22 million). The observed concentrations of sulfur dioxide (SO(2), mean=23.3 ppb), ozone (O(3), mean=23.7 ppb), and total suspended particulates (TSP, mean=77.9 microg/m(3)) during the study period were at levels below Korea's current ambient air quality standards. Generalized additive models were applied to allow for the highly flexible fitting of seasonal and long-term time trends in air pollution as well as nonlinear associations with weather variables, such as air temperature and relative humidity. In city-specific analyses, an increase of 50 ppb of SO(2) corresponded to 1-12% more deaths, given constant weather conditions. The risk of all-cause mortality was estimated to increase by 0.5-4%, with an increase in the 2-day moving average of TSP levels equal to 100 microg/m(3). In multipollutant models with pooled data, we found that the estimated risk of death by SO(2) was notably unaffected by adding the other two pollutants (TSP and O(3)) to the model and was statistically significant in various regression models. The rate ratio (RR) for SO(2) remained elevated, indicating an excess mortality of 3% 50 ppb (RR=1.03; 95% CI, 1.01-1.05). TSP's effect on mortality maintained its significance with O(3), but not with SO(2). This implies that there may be collinearity problems where TSP and SO(2) are included in the same model or that TSP may function less than SO(2) as a surrogate for fine particles in the ambient air of Korea. In conclusion, increased mortality was associated with air pollution at SO(2) levels below the current recommendation for air quality. Further research is needed to clarify the relationship between SO(2) and fine particles in Korea.

Influence of genetic susceptibility on the urinary excretion of 8-hydroxydeoxyguanosine of firefighters

OBJECTIVES

Oxidative DNA damage has been implicated in carcinogenesis. The DNA damage can be assessed from the urinary excretion of the DNA-repair product 8-hydroxydeoxyguanosine (8-OH-dG). The factors were investigated that influenced the excretion of urinary 8-OH-dG in 78 firefighters.

METHODS

53 Out of 78 firefighters were exposed to fire within 5 days of the study and 25 were not. 8-OH-dG was measured by ELISA and the distribution of the genotypes of CYP1A1, CYP2E1, GSTM1, and GSTT1 was measured by polymerase chain reaction.

RESULTS

The homozygous wild type frequencies of CYP1A1 MspI, CYP1A1 ile-val, CYP2E1, GSTM1, and GSTT1 were 31.5%, 56.2%, 60.3%, 50.7%, and 53.4%, respectively. The geometric mean of urinary 8-OH-dG was 14.1 ng/mg creatinine in more active firefighters and 12.3 ng/mg creatinine in non-exposed and less active subjects. Significantly increased concentrations of urinary 8-OH-dG were found to be associated with cigarette smoking, and 14% of the variation of 8-OH-dG was explained by cigarettes smoked per day. The CYP1A1 MspI, CYP1A1 ile-val, GSTM1, and GSTT1 genetic polymorphisms were not found to be significantly associated with the urinary excretion of 8-OH-dG. However, the subjects carrying the CYP2E1 mutant type excreted higher concentrations of 8-OH-dG and there was a marginally significant interaction of GSTT1 with firefighting activity. Multiple regression analysis confirmed that smoking was the strongest predictor of excretion of 8-OH-dG. Age, body mass index, and firefighting activity were not significant predictive factors for urinary 8-OH-dG.

CONCLUSION

Smoking and CYP2E1 gene polymorphism may be important factors in carcinogenesis and the GSTT1 positive genotype may be a genetic susceptibility factor in firefighters who are exposed regularly to various chemical carcinogens.

Pulmonary fibrosis in a steel mill worker

We report a case of pulmonary fibrosis in a 32-year-old man, who had worked at a steel mill and who died of respiratory failure due to interstitial fibrosis despite vigorous treatment. He showed SLE-associated symptoms, such as pleural effusion, malar rashes, discoid rashes, arthritis, leukopenia, and positive antinuclear antibody and anti-histone antibody. However, he did not present anti-DNA antibody. A thoracoscopic lung biopsy showed interstitial fibrosis, chronic inflammation and a small non-caseating granuloma in lung tissues, which could be induced by external agents such as metals. The manganese concentration in the lung tissue was 4.64 microg/g compared to 0.42-0.7 microg/g in the controls. The levels of other metals, such as iron, nickel, cobalt and zinc in patient's lung tissue were higher than those in the controls. The patient was probably exposed to Si and various metal dusts, and the lung fibrosis was related to these exposures. Exposure to Si and metal dusts should be sought in the history of any patient with SLE, especially in a male with pulmonary signs, and if present, exposure should be stopped. In the meantime, steps should be taken to ensure that workers exposure to Si and metal dusts in all environments have adequate protection.

Helicobacter pylori infection with iron deficiency anaemia and subnormal growth at puberty

The purpose of this study was to determine whether Helicobacter pylori infection can contribute to growth deficit, especially in pubescent children who need large amounts of iron for growth. A structured questionnaire was sent to the parents of 532 healthy children aged 10 to 15 years (mean 12.9) to obtain demographic information on the parents and the environment. Of the 532 questionnaires sent out, 375 (70.5%; 170 girls and 205 boys) were returned. After collecting blood samples from participants, haemoglobin, serum iron, total iron binding capacity, serum ferritin, and serum IgG antibodies to H pylori were measured. The effects of risk factors such as H pylori infection, iron deficiency anaemia, sex, socioeconomic status, type of house, and crowding index on growth were analysed using multiple regression analysis. Of 63 H pylori positive children, 18 (28.6%) were below the 25th centile values for height, compared with 63 of 312 (20.2%) H pylori negative children. The prevalence rate of H pylori infection was 15.5% (53 of 343) in children without iron deficiency anaemia and 31.3% (10 of 32) in those affected. The relative risk of short stature was 2.2 (95% confidence interval (CI), 1.0 to 4.8) for iron deficiency anaemia, and 1.4 (95% CI, 0.8 to 2.4) for H pylori infection. The mean height was significantly lower in the group having both H pylori infection and iron deficiency anaemia. Therefore, H pylori infection accompanied by iron deficiency anaemia, rather than H pylori infection per se, might delay pubertal growth.

PM(10) exposure, gaseous pollutants, and daily mortality in Inchon, South Korea

To evaluate the relative importance of various measures of particulate and gaseous air pollution as predictors of daily mortality in Inchon, South Korea, the association between total daily mortality and air pollution was investigated for a 20-month period (January 1995 through August 1996). Poisson regression was used to regress daily death counts on each air pollutant, controlling for time trends, season, and meteorologic influences such as temperature and relative humidity. Regression coefficients of a 5-day moving average of particulate matter less than or = to 10 microm in aerodynamic diameter (PM(10)) on total mortality were positively significant when considered separately and simultaneously with other pollutants in the model. PM(10) remained significant when the models were confined to cardiovascular or respiratory mortality. Sulfur dioxide (SO(2)) and carbon monoxide (CO) were significantly related to respiratory mortality in the single-pollutant model. Ozone exposure was not statistically significant with regard to mortality in the above models, and graphic analysis showed that the relationship was nonlinear. A combined index of PM(10), nitrogen dioxide, SO(2), and CO seemed to better explain the exposure-response relationship with total mortality than an individual air pollutant. Pollutants should be considered together in the risk assessment of air pollution, as opposed to measuring the risk of individual pollutants.

Variations in urinary 1-hydroxypyrene glucuronide in relation to smoking and the modification effects of GSTM1 and GSTT1

The measurement of the pyrene metabolite, 1-hydroxypyrene, in human urine has been used to assess recent exposure to polycyclic aromatic hydrocarbons (PAH). The objective of this study was to see whether genetic polymorphisms in metabolic enzymes could explain some of the variation in urinary 1-hydroxypyrene glucuronide (1-OHPG) excretion in relation to smoking. Forty-seven male hospital workers, who were not occupationally exposed to PAH, participated in this study. The urine samples were analyzed for 1-OHPG utilizing immunoaffinity chromatography and synchronous fluorescence spectroscopy. The analysis of GSTM1 and GSTT1 polymorphism was performed by PCR. The 1-OHPG concentration in the urine of the hospital workers was 0.57 +/- 0.85 micromol/mol creatinine, and ranged from 0.02 to 5.04 mciromol/mol creatinine. Cigarette smoking was significantly correlated with urinary 1-OHPG (r = 0.3976, P = 0.0056). The 1-OHPG excretion in GSTM1-deficient smokers was higher than that in GSTM1-positive smokers. On the other hand, 1-OHPG excretion was higher in GSTT1-positive smokers than in GSTT1-deficient smokers. It is important to note the variability of individual PAH metabolite excretion due to different GSTM1 and GSTT1 genotypes.

Air pollution and daily mortality in Inchon, Korea

The association between total daily mortality and air pollution was investigated for a 1-year period (January 1995 to December 1995) in Inchon, Korea. The purpose of this study was to evaluate the relative importance of particulate and gaseous air pollution as predictors of daily mortality. Concentration of total suspended particulates (TSP), inhalable particles (PM10), and gaseous pollutants, such as sulfur dioxide, nitrogen dioxide, ozone, carbon monoxide, were measured daily during the study period. A generalized additive model was used to regress daily death counts on each air pollutant, controlling for time trend and meteorologic influences such as temperature or relative humidity. Total mortality was found to increase 1.2% (95% CI: 0.2 to 2.2%) for each 10 microg/m3 increase in 6-day moving average of TSP, and 1.2% (95% CI 0.2 to 2.1%) for each 10 microg/m3 increase in 5-day moving average of PM10. The association is similar in magnitude to associations between particulate air pollution and mortality found in several other communities in America and Europe. Associations with gaseous pollutants were all statistically insignificant in the generalized additive model. The relative risk of death increased at particulate levels that were well below the current Korean Ambient Air Quality Standard.

Randomized placebo-controlled trial of Helicobacter pylori eradication for iron-deficiency anemia in preadolescent children and adolescents

BACKGROUND

A few cases relating H. pylori infection to iron-deficiency anemia have been described recently. We investigated the role of H. pylori infection in iron-deficiency anemia in preadolescent children and adolescents.

PATIENTS AND METHODS

We conducted a double-blind, placebo-controlled therapeutic trial in 43 subjects (mean age, 15.4 years) with iron-deficiency anemia. Endoscopy was performed, and biopsy specimens were examined by urease test and histological analysis. Twenty-two of 25 H. pylori-positive patients were assigned randomly to three groups. Group A patients were given oral ferrous sulfate and a 2-week course of bismuth subcitrate, amoxicillin, and metronidazole. Group B patients were given placebo for iron and a 2-week course of triple therapy. Group C patients were given oral ferrous sulfate and a 2-week course of placebo. Iron status was reassessed 4 weeks and 8 weeks after the 2-week regimen ended.

RESULTS

Of the 43 subjects with iron-deficiency anemia, 25 (58.1%) had H. pylori in the antrum. Group A and B subjects, who received eradication therapy, showed a significant increase in hemoglobin level as compared with group C subjects at 8 weeks after therapy (p = .0086).

CONCLUSIONS

Treatment of H. pylori infection was associated with more rapid response to oral iron therapy as compared with the use of iron therapy alone. Such treatment also led to enhanced iron absorption even in those subjects who did not receive oral iron therapy.

Enhancement of DNA damage and involvement of reactive oxygen species after exposure to bitumen with UVA irradiation

This study was carried out to evaluate whether bitumen cytotoxicity is enhanced when bitumen treatment is combined with UVA exposure. We also evaluated the oxidative processes in bitumen-induced DNA damage, and attempted to identify the DNA damage caused by bitumen and UVA exposures, either alone or in combination. The effects of bitumen and UVA on cell proliferation were examined using HL 60 cells. DNA-protein crosslinks (DPCs) were assessed using a K-SDS assay, and reactive oxygen species formation was detected by 8-OH-dG formation. We evaluated the formations of double-strand breaks (DSB) using lambdaDNA/HindIII and single-strand breaks (SSB) using PM2 DNA. The cytotoxicity assay showed enhanced suppression of cell proliferation when bitumen exposure and UVA exposure were combined. Combined exposure caused significant increases in DPCs over either exposure alone. Incubation of deoxyguanosine (dG) with bitumen or UVA showed an increase in 8-hydroxy-2'-deoxyguanosine (8-OH-dG) levels when compared with controls, and combined exposure enhanced this effect. An evaluation of agarose gel bands showed that DSB and SSB were not formed following exposure to bitumen and UVA. This fact indicates that bitumen and UVA may be involved in genotoxic processes by producing oxygen free radicals and that combined exposure enhances these effects.

Measurement of prostaglandin E2 and leukotriene B4 in the gingival crevicular fluid

The arachidonic acid metabolites prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) are inflammatory mediators which are likely to be involved in the pathogenesis of periodontal disease. PGE2 mediates vasodilatation, increases vascular permeability, enhances pain perception by bradykinin and histamine, alters connective tissue metabolism and enhances osteoclastic bone resorption. LTB4 causes the accumulation of inflammatory cells in the inflamed sites, and degranulation of polymorphonuclear leukocytes.

OBJECTIVE

To measure gingival crevicular fluid (GCF) levels of PGE2, LTB4 and periodontal health.

METHODS

The periodontal condition of 24 subjects was evaluated on the basis of plaque index, gingival index, probing depth, and attachment level. GCF samples were collected from one or two site(s) of each sextant per subject and the volume was measured using Periotron 6000. Samples were then assayed for PGE2 and LTB4 using a competitive enzyme immunoassay. Mean PGE2 and LTB4 levels were determined for each subject and group means compared.

RESULTS

Significant differences in the levels of PGE2 and LTB4 were found between patients with periodontitis, and non-periodontitis individuals (P < 0.001). The PGE2/LTB4 levels were positively correlated with the clinical parameters (P < 0.01) and reduced markedly after phase 1 of the periodontal treatment (P < 0.01). The total amount and concentration (ng ml-1) of LTB4 was positively correlated with the gingival index (P < 0.01).

CONCLUSIONS

These results indicate that the levels of PGE2 correlated with the severity of the periodontal status, and the levels of LTB4 correlated with gingival inflammation. Thus, our data suggest that the total amounts of PGE2/LTB4 may be good indicators for periodontal inflammation.

Magnesium inhibits nickel-induced genotoxicity and formation of reactive oxygen

Nickel compounds are recognized to cause nasal and lung cancers. Magnesium is an effective protector against nickel-induced carcinogenesis in vivo, although its mechanisms of protection remain elusive. The effects of magnesium carbonate on the cytotoxicity and genotoxicity induced by nickel subsulfide were examined with respect to the inhibition of cell proliferation, micronuclei formation, DNA-protein cross-link formation, and intranuclear nickel concentration. The generation of reactive oxygen by nickel chloride was also analyzed by observing 8-hydroxy-deoxyguanosine formation from deoxyguanosine in the presence and absence of magnesium chloride. The suppression of up to 64% of the proliferation of BALB/3T3 fibroblasts by nickel subsulfide (1 microgram/ml) was reversed by magnesium. The nickel compound increased not only the number of micronuclei but also the amount of DNA-protein cross-links examined with CHO and BALB/3T3 cells, respectively. These genotoxic effects of nickel were again lessened by magnesium carbonate. In addition, the cellular accumulation of nickel increased 80-fold with nickel subsulfide treatment and decreased with magnesium carbonate treatment. Nickel also enhanced 8-hydroxy-deoxyguanosine formation in the presence of H2O2 and ascorbic acid, where magnesium played another suppressive role. In fact, inhibition by magnesium was still observed even in the absence of nickel treatment. These results suggest that the protective role of magnesium in nickel-induced cytotoxicity and genotoxicity can be attributed to its ability to reduce either the intracellular nickel concentration or reactive oxygen formation.

Cytotoxicity and multinucleate giant cell formation in Chinese hamster lung fibroblast caused by crocidolite and chrysotile

The mechanism of carcinogenic action of asbestos remains unclear but the physical properties of the fiber appear to be important in this process. Asbestos may cause multinucleate giant cell formation primarily by interfering with the normal course of mitosis. We evaluated the cytotoxicity and multinucleate giant cell formation induced by crocidolite and chrysotile in Chinese hamster lung fibroblast (V79 cell) with observation of phagocytic activities. Asbestos fibers were rapidly ingested by V79 cells and most fibers were inside the cells. Cytotoxicity was evaluated by observing inhibition of V79 cell proliferation with trypan blue exclusion test. For determination of frequency of multinucleate giant cells, the cells were treated with different doses of crocidolite or chrysotile for 72 hours. Crocidolite and chrysotile induced cytotoxicity in V79 cells in a dose-dependent manner. The pattern of inhibition of cell proliferation is similar for both types of fibers, but chrysotile was more potent at the highest level (20.0 micrograms/ml) of fiber concentration. There was a good relationship (regression coefficientcrocidolite = 0.02, P < 0.01; regression coefficientchrysotile = 0.04, P < 0.01) between the dose of both asbestos fibers and the frequency of multinucleate giant cells. Chrysotile was again more potent at inducing multinucleate giant cells in higher levels of fiber concentrations. We found that asbestos fibers were cytotoxic after phagocytosis and induced multinucleate giant cells by interfering mitosis.

Changes of respiratory chain enzyme activities in growing rat muscle mitochondria

The activities of three mitochondrial respiratory chain enzymes, namely rotenone sensitive NADH-cytochrome c reductase (NCCR), succinate-cytochrome c reductase (SCCR), and cytochrome c oxidase (CCO) in the extensor digitorum longus muscle were determined in Wistar rats, twenty each, at 3, 4, 5, 6, 10 and 26 weeks of age. The activity of NCCR was extremely low from birth up to 10 weeks of age. The activity of SCCR was stable at 64% to 72% during the first 6 weeks of life and increased to 78% of the adult level at 10 weeks of age. The CCO activity was only 52% of the adult level at 3 weeks of age, increased to 78% to 86% during the next 3 weeks and reached 92% at 10 weeks of age which was not statistically different from the adult level. We conclude that the activities of these 3 respiratory chain enzymes, in muscle mitochondria in rats, were low during development and reached the adult levels at various ages. Before the normal values of these enzyme activities can be established in human pediatric population, age-matched control should be used as the reference value for evaluation of mitochondrial myopathy.

[Hemophilus aphrophilus meningitis: report of one case]

Hemophilus aphrophilus, a gram negative, capnophilic slow growing bacillus, is a rarely recognized pathogen in meningitis and is most frequently seen in patients with either endocarditis or brain abscess. This article reported one case with Hemophilus aphrophilus meningitis. A 10-year-old boy presented at the emergency room with chief complaint of fever for 2 days and sudden onset of loss of consciousness. Hemophilus aphrophilus was isolated from the blood and cerebrospinal fluid. Aqueous penicillin and chloramphenicol were given for three weeks. The patient discharged without any sequelae. Three months later, fever and consciousness disturbance were noted again. No pathogen was isolated from the cerebrospinal fluid and blood culture this time, but CSF finding was consistent with bacterial meningitis. Aqueous penicillin and chloramphenicol were readministered for 30 days. The patient recovered smoothly. Because the patient had no history of CSF rhinorrhea or hypogammaglobulinemia, recurrence of the bacterial meningitis could be due to incomplete treatment during the first admission. Brain computed tomography (CT) done during the two admissions showed focal cortical enhancement in the fronto-temporo-parietal region. This is presumed to indicate infarction over these regions. The findings of brain CT are in accordance with the development of hemiplegia in the patient. It is still unknown, however, whether Hemophilus aphrophilus meningitis also causes a higher incidence of brain infarction, which was frequently noted in patients with Hemophilus influenzae meningitis.

The periapical tissue reactions to a calcium phosphate cement in the teeth of monkeys

A calcium phosphate cement, Grossman sealer, and Sargenti N2 were compared under conditions where root canals of monkey incisors were deliberately overfilled and the apical tissue responses were evaluated histologically. The periapical tissues exposed to Sargenti N2 revealed severe irritation at all times through the 6-month experimental period. The reactions to Grossman sealer were milder but persisted throughout the observation period. The calcium-phosphate-cement treated animals showed mild tissue irritation after 1 month, but thereafter the adverse tissue reactions were minimal. New bone formation adjacent to the cement was also observed. These results point to the possibility that calcium phosphate cement might be used in simplified endodontic procedures. The compatibility of calcium phosphate cement with the periapical tissue suggests that the cement may have other applications in dentistry and medicine.

Histologic reactions to a newly developed calcium phosphate cement implanted in the periapical and periodontal tissues

A newly developed calcium phosphate cement (CPC), basically composed of tetracalcium phosphate, Ca4(PO4)2O and dicalcium phosphate dihydrate, CaHPO4.2H2O or anhydrous calcium phosphate, CaHPO4, was tested in this study. When combined with water, the cement hardens and produces hydroxylapatite resembling the principal mineral of teeth and bones. Therefore, the CPC should be highly compatible with the body. However, before its clinical application in dentistry, the biocompatibility of CPC in the potential environments of implantation needs confirmation. Eight monkeys were used in our study to test the material in the periapical and marginal periodontal regions. Surgically created periodontal defects were implanted with CPC and hydroxylapatite (HA) (Calcitite 4060). In another application, CPC was pushed into the periapical areas via overfilling of the root canals. Sargenti N2 served as the control material in the periapical test. Generally, only a limited inflammatory response to CPC was found after 6 weeks of implantation in the periodontal area. In the 16-week specimens, the adverse reaction was negligible, and bone regeneration was marked and directly surrounding the CPC. The bone formation activity and biocompatibility in general were found to be even better in the periapical region. The results suggest that the CPC may have a good potential in future clinical applications, although many issues remain to be investigated.

Prevalence of mottled enamel after 12 years of water fluoridation in Chung-hsing New Village

The prevalence of mottled enamel (dental fluorosis) was investigated among children, aged 6 to 15 years, in Chung-hsing New Village and in Tsao-tun Village. The drinking water in Chung-hsing New Village has been fluoridated for 12 years at a level of 0.6 ppm, while the drinking water in Tsao-tun contains a negligible level of 0.08 ppm. The degree of mottled enamel was assessed by using Dean's Index and the Community Fluorosis Index (CFI), the latter being derived from Dean's Index for the purpose of comparison. In Dean's Index, 6 classes based on the severity of the mottling, are identified: normal, questionable, very mild, mild, moderate, and severe. The results showed that children in Chung-hsing had whiter teeth than those in Tsao-tun Village. In the fluoridated group, 5.8% of children fell into the "very mild" mottling category, as compared to 0.9% in Taso-tun, the control area. For the "mild" class, the rate was 1.9% for Chung-hsing New Village and 0.4% for Tsao-tun. With only one exception in Tsao-tun, none of the children in the two groups showed mottling in the "moderate" or "severe" classes. The Community Fluorosis Index (CFI) was 0.15 for the Chung-hsing group, indicating that the occurrence of mottled enamel is very low when compared with data from fluoridation programs in other countries. It is concluded that in Taiwan, a 0.6 ppm fluoride concentration in drinking water, which has previously been reported to be effective in prevention of dental caries, is associated with only negligible mottling of enamel. Even when mottling does occur, the degree is very mild and only small chalky spots can be seen on the teeth.

Influence of water fluoridation on the eruption of permanent teeth in Chung-Hsing New Village, Taiwan

Along with an evaluation of the effects of 12 years' water fluoridation in the prevention of caries, the present study was conducted to explore the influence of water fluoridation on the eruption of permanent teeth. The survey was carried out in fluoridated Chung-Hsing New Village and the control town of Tsao-Tun from October to December, 1984. Dental examinations were performed on 3,459 children Chung-Hsing New Village and 4,610 in Tsao-Tun, at ages ranging from 3 to 15 years. The results showed that in general, the mean tooth eruption time of girls was earlier than that of boys, and that teeth in the lower jaw emerge sooner than their homologues in the upper jaw, except for premolars. In both fluoridated and control areas the order of tooth eruption was very similar except for the teeth of girls in the upper jaw. The eruption sequence was first premolar, canine then second premolar in the girls of Chung-Hsing New Village, while first premolar, second premolar then canine in those of Tsao-Tun. By comparing the eruption time of permanent teeth in the children of fluoridated and control areas, it was found that they were very alike in general, the only difference being observed in the premolars of the sexes. The premolars of the children in the fluoridated area emerged in the oral cavity 2.5 to 4.5 months later than did their counterparts in the control area.(ABSTRACT TRUNCATED AT 250 WORDS)

Application of a microcomputer-based system in the analysis of infection data at the emergency units of a large hospital

After three years of retrospective study in four emergency units from a large hospital (2000 beds) and analysis of 6283 positive cultures, a microcomputer database system was built to store information concerning nosocomial infections in order to help the clinical staff from those units to study the incidence of 20 bacterial species and their sensitivity pattern evolutions for 27 antibiotics (from samples in 15 different collecting sites). This system was developed as an alternative to the hospital mainframe computer microbiological reports. It put emphasis on graphical outputs instead of the coded tables generated by the bigger system. This orientation and the possibility of sectorial infection data analysis were responsible for the general acceptance of the microcomputer-based system by the clinical staff. As the first practical results, the system was able to detect a particular increase in the incidence of Staphylococcus aureus in surgical emergency units (up to 21.6% in 1982) as well as the dissemination of the antimicrobial resistance patterns of S. aureus and Klebsiella pneumoniae from the surgical units to the clinical ones. The time evolution behaviour of Pseudomonas aeruginosa, Escherichia coli and other nonfermentative Gram negative bacilli was also studied to complete the analysis of the most pathogenic bacterial species found in our emergency units.

Enhanced fluoride uptake from mouthrinses

It has been shown in laboratory and animal studies that tooth enamel becomes considerably more reactive toward low levels of fluoride after receiving pre-treatment which forms dicalcium phosphate dihydrate (DCPD) in the enamel as an intermediate. This in vitro study was undertaken to determine the effect on human enamel fluoride uptake of incorporating DCPD-forming rinses into a conventional fluoride rinsing program. In one group, enamel samples received a one-minute rinse with 0.2% NaF each day for 20 days. Samples in the second group were treated identically, except that they were also given a one-minute DCPD-forming rinse prior to the first, sixth, eleventh, and sixteenth fluoride rinses. At the end of the rinsing program, all samples were washed in 1 M KOH to remove labile fluorides. The enamel biopsy data showed that the fluoride uptake resulting from 0.2% NaF alone was not statistically significant, whereas uptake produced by the DCPD-forming plus NaF rinses was significant. The results suggest that the DCPD-forming rinse may improve the efficacy of fluoride rinse programs.

Reactions of powdered human enamel and fluoride solutions with and without intermediate CaHPO4 x 2H2O formation

Powdered human enamel treated for three minutes each with a CaHPO4 x 2H2O forming solution and a fluoride solution, and then suspended in "synthetic saliva" for 72 hours acquired a large amount of apatitic fluoride. This apatitic fluoride appears to form after the fluoride treatment.

Effects of some staining agents on dentin apposition in young rabbits

Alizarin red S, trypan blue, chlortetracycline, and 45Ca were administered to young rabbits that received multiple injections of lead acetate as marker. Inhibiting effects of these agents on dentin apposition were studied. No evidence of toxicity of chlortetracycline or 45Ca was detected. Alizarin at 100 mg/kg reduced the rate of dentin apposition, and 150 mg/kg caused severe retardation. Trypan blue at 50 to 100 mglkg showed no adverse effects, but 350 mglkg arrested dentinogenesis completely.