Impact of right ventricular reserve on exercise capacity and quality of life in patients with left ventricular assist device

Background

Right heart failure following left ventricular assist device (LVAD) implantation is a major complication which significantly impairs functional capacity and quality of life (QoL). Right ventricular (RV) reserve function may limit exercise capacity and QoL in LVAD patients; however, most patients show normal RV haemodynamics at rest.

Purpose

The aim of this study was to investigate whether RV reserve assessed by the changes of RV function during exercise is correlated with exercise capacity and QoL in patients with LVAD.

Methods

We prospectively examined 20 consecutive LVAD patients who were admitted to our university hospital between June 2020 and November 2021 after excluding those who were unable to perform exercise (n=8). All patients underwent invasive exercise right heart catheterisation with simultaneous echocardiography in the supine position. RV stroke work index (RVSWI) was calculated as 0.0136 × stroke volume index × (mean pulmonary artery pressure [mPAP] − right atrial pressure [RAP]) at rest and during exercise. Exercise capacity and QoL were assessed by 6-minute walk distance (6MWD) and peak oxygen consumption (VO2) in cardiopulmonary exercise testing, and the EuroQol visual analogue scale (EQ-VAS), respectively. The patients were divided into two groups according to the median ΔRVSWI (RVSWI change from rest to peak exercise) of 1.45 (interquartile range [IQR] −0.31 to 8.25) g/m2.

Results

Patients were predominantly male (75%) and the median age was 47 (IQR 38–60) years. Patients with lower ΔRVSWI had significantly higher change on RAP (P=0.019), but significantly lower change on mPAP (P<0.001) compared to those with higher ΔRVSWI. There were no significant differences in age, gender, primary aetiology of heart failure, type of LVAD devices, or echocardiographic parameters including tricuspid annular plane systolic excursion, and RVSWI at rest between the groups. ΔRVSWI during exercise were positively correlated with 6MWD (R=0.69, P<0.01) and peak VO2 (R=0.66, P<0.01) (Figure A). In addition, ΔRVSWI during exercise were positively correlated with the EQ-VAS (R=0.48, P=0.031). On the other hand, there was no significant correlation between RVSWI at rest and 6MWD (R=−0.11, P=0.63) and peak VO2 (R=0.13, P=0.95), and the EQ-VAS (R=0.11, P=0.61). During a median follow-up period of 312 (IQR 176–369) days, adverse events occurred in 3 patients (15%), including 1 death and 2 hospitalisations for major bleeding and right heart failure. Kaplan-Meier analysis revealed that the adverse events more frequently occurred in patients with lower ΔRVSWI compared to those with higher ΔRVSWI (Figure B).

Conclusions

ΔRVSWI was positively correlated with 6MWD, peak VO2 and EQ-VAS irrespective of RV function at rest. Our findings suggest that the assessment of RV reserve function using ΔRVSWI would be useful for risk stratification in patients with LVAD.

Funding Acknowledgement

Type of funding sources: None.

Salicylic Acid Acts Antagonistically to Plastid Retrograde Signaling by Promoting the Accumulation of Photosynthesis-associated Proteins in Arabidopsis

Plastids are involved in phytohormone metabolism as well as photosynthesis. However, the mechanism by which plastid retrograde signals and phytohormones cooperatively regulate plastid biogenesis remains elusive. Here, we investigated the effects of an inhibitor and a mutation that generate biogenic plastid signals on phytohormones and vice versa. Inhibition of plastid biogenesis by norflurazon (NF) treatment and the plastid protein import2 (ppi2) mutation caused a decrease in salicylic acid (SA) and jasmonic acid (JA). This effect can be attributed in part to the altered expression of genes involved in the biosynthesis and the metabolism of SA and JA. However, SA-dependent induction of the PATHOGENESIS-RELATED1 gene was virtually unaffected in NF-treated plants and the ppi2 mutant. Instead, the level of chlorophyll in these plants was partially restored by the exogenous application of SA. Consistent with this observation, the levels of some photosynthesis-associated proteins increased in the ppi2 and NF-treated plants in response to SA treatment. This regulation in true leaves seems to occur at the posttranscriptional level since SA treatment did not induce the expression of photosynthesis-associated genes. In salicylic acid induction deficient 2 and lesions simulating disease resistance 1 mutants, endogenous SA regulates the accumulation of photosynthesis-associated proteins through transcriptional and posttranscriptional mechanisms. These data indicate that SA acts antagonistically to the inhibition of plastid biogenesis by promoting the accumulation of photosynthesis-associated proteins in Arabidopsis, suggesting a possible link between SA and biogenic plastid signaling.

Validation of the HFA-PEFF and the H2FPEF scores for the diagnosis of heart failure with preserved ejection fraction in Japanese patients:a report from the Japanese multicentre registry

Background

The standard diagnosis of heart failure (HF) with preserved ejection fraction (HFpEF) is based on the following: 1) symptoms of HF, 2) preserved left ventricular (LV) ejection fraction (LVEF, >50%), and 3) presence of LV diastolic dysfunction confirmed by echocardiography or cardiac catheterisation. However, there are limits to the diagnostic accuracy of individual parameters, and what cut-off values should be applied and how they should be combined remain unclear. Diagnostic algorithms for HFpEF such as the HFA-PEFF algorithm and the H2FPEF score have been proposed; however, previous validation studies were conducted in stable chronic HF and did not include an invasive haemodynamic assessment. Thus, the diagnostic accuracy for HFpEF lacked robustness. Moreover, information on their applicability in the Asian population is limited.

Purpose

The aim of this study was to investigate these scores' diagnostic validity for HFpEF in Japanese patients recently hospitalised due to acute decompensated HF.

Methods

We examined patients with HFpEF recently hospitalised with acute decompensated HF whose HFA-PEFF and H2FPEF scores could be calculated at discharge from a nationwide HFpEF-specific multicentre registry (HFpEF group) and control patients who underwent echocardiography to investigate the cause of dyspnoea in our hospital (Non-HFpEF group). We calculated the HFA-PEFF and the H2FPEF scores among the studied population. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were computed to compare the diagnostic accuracy of these scores.

Results

The studied population included 372 consecutive patients (194 HFpEF group and 178 Non-HFpEF group; HFpEF prevalence, 52%). The HFA-PEFF score classified 155 (42%) of all patients into the high likelihood category (5–6 points) and only 19 (5%) into the low likelihood category (0–1 point). A high HFA-PEFF score could diagnose HFpEF with a high specificity of 84% and a positive predictive value (PPV) of 82%, and a low HFA-PEFF score could rule out HFpEF with a high sensitivity of 99% and a negative predictive value (NPV) of 89%. The H2FPEF score classified 86 (23%) of all patients into the high likelihood category (6–9 points) and 84 (23%) into the low likelihood category (0–1 point). HFpEF could be diagnosed with a high H2FPEF score (specificity, 97%; PPV, 94%) or ruled out with a low H2FPEF score (sensitivity, 97%; NPV, 93%). The diagnostic accuracy for the HFA-PEFF and H2FPEF scores was 0.82 (95% confidence interval [CI] 0.78–0.86) and 0.89 (95% CI 0.86–0.93), respectively, by the AUC of the ROC curve (P=0.004) (Figure 1A). In the HFA-PEFF sub-scores, the functional score showed little diagnostic value, while the morphological and biomarker scores showed moderate diagnostic value (Figure 1B).

Conclusions

The H2FPEF score may be more useful than the HFA-PEFF score in diagnosing HFpEF in Japanese patients.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS KAKENHI) Figure 1

Applicability of the AHA/ACC/HRS guideline for implantable cardioverter defibrillator implantation in Japanese patients with cardiac sarcoidosis

Background

Sarcoidosis is a systemic granulomatous disease that affects multiple organs. Cardiac involvement is a key determinant of poor clinical outcomes in the patients with sarcoidosis, as it causes congestive heart failure, conduction abnormalities, ventricular tachycardia and fibrillation (VT/VF), and sudden cardiac death (SCD). Although implantable cardioverter defibrillators (ICDs) are used to prevent SCD from VT/VF in patients with cardiac sarcoidosis (CS), the generalizability of the AHA/ACC/HRS guidelines for the Japanese CS patients remains unclear.

Purpose

We aimed to assess, among Japanese patients with CS, the ICD recommendations from the 2017 AHA/ACC/HRS Guidelines for Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death.

Methods

We examined 188 consecutive patients with CS in two tertiary hospitals between 1979 and 2020. The primary outcome was defined as a composite outcome involving SCD or ventricular arrhythmic events. Ventricular arrhythmic events were defined as either emergency treatment for VF or sustained VT, which included appropriate ICD therapy.

Results

During a median follow-up period of 5.68 (IQR: 4.87–6.70) years, the primary outcome occurred in 44 patients (23%), which included 6 cases of SCD and 38 cases of VT/VF. ICD implant was indicated based on left ventricular ejection fraction (LVEF) of ≤35% (class I recommendation) in 62 patients, with an annualized event rate of 3.93%. A LVEF of >35% with a need for a permanent pacemaker (class IIa recommendation) was observed for 53 patients, with an annualized event rate of 2.54%. A LVEF of >35% with late gadolinium enhancement (LGE) during cardiovascular magnetic resonance (class IIa recommendation) was observed for 62 patients, with an annualized event rate of 2.38% (Figure A). Kaplan-Meier analyses revealed that patients with a class I recommendation for ICD implantation had a significant higher incidence of the primary outcome, compared to patients with a class IIa recommendation and patients with no indication for ICD implantation (P=0.03). However, there were no significant differences in the incidence of the primary outcome between patients with a LVEF of >35% and a need for a permanent pacemaker and patients with a class I recommendation (P=0.08) or patients with a LVEF of ≤35% (P=0.31). Moreover, there was no significant difference in the incidence of the primary outcome between patients with a LVEF of >35% and LGE on cardiovascular magnetic resonance and patients with a class I recommendation (P=0.054) or patients with a LVEF of ≤35% (P=0.22) (Figure B).

Conclusions

The American guideline recommendations for ICD implantation might be applicable to Japanese patients with CS. Implantation of an ICD may need to be considered in these patients if they require a permanent pacemaker or have LGE, regardless of LVEF.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science

Induction of TOC and TIC genes during photomorphogenesis is mediated primarily by cryptochrome 1 in Arabidopsis

The majority of genes encoding photosynthesis-associated proteins in the nucleus are induced by light during photomorphogenesis, allowing plants to establish photoautotrophic growth. Therefore, optimizing the protein import apparatus of plastids, designated as the translocon at the outer and inner envelope membranes of chloroplast (TOC–TIC) complex, upon light exposure is a prerequisite to the import of abundant nuclear-encoded photosynthesis-associated proteins. However, the mechanism that coordinates the optimization of the TOC–TIC complex with the expression of nuclear-encoded photosynthesis-associated genes remains to be characterized in detail. To address this question, we investigated the mechanism by which plastid protein import is regulated by light during photomorphogenesis in Arabidopsis. We found that the albino plastid protein import2 (ppi2) mutant lacking Toc159 protein import receptors have active photoreceptors, even though the mutant fails to induce the expression of photosynthesis-associated nuclear genes upon light illumination. In contrast, many TOC and TIC genes are rapidly induced by blue light in both WT and the ppi2 mutant. We uncovered that this regulation is mediated primarily by cryptochrome 1 (CRY1). Furthermore, deficiency of CRY1 resulted in the decrease of some TOC proteins in vivo. Our results suggest that CRY1 plays key roles in optimizing the content of the TOC–TIC apparatus to accommodate the import of abundant photosynthesis-associated proteins during photomorphogenesis.

Basket-weave structure in the stratum corneum is an important factor for maintaining the physiological properties of human skin as studied using reconstructed human epidermis and tape stripping of human cheek skin

BACKGROUND

The normal stratum corneum (SC) has an upper basket-weave (BW) pattern layer and a lower compact layer. The transition from compact to BW SC is well associated with a transition from diffuse to peripheral distributions of corneodesmosomes (CDs). The loss of transition from compact SC to BW SC appears to cause structural and barrier-function impairments.

OBJECTIVES

To show the involvement of the BW SC in maintaining the physiological properties of the skin.

METHODS

Reconstructed human epidermis (RHE) with a complete BW structure was created by treatment with prepared emulsion-A, an oil-in-water emulsion. The RHE tissues were subjected to histological analysis, and the distribution of CDs on the SC with or without BW SC was analysed by anti-desmoglein (Dsg)1 antibody immunofluorescence and ultrastructural and Western blotting analyses. Ultrastructural analysis of intercellular lipids was performed. The mechanical properties of the RHE were evaluated.

RESULTS

Emulsion-A successfully generated the BW SC in the RHE in which the degradation of CDs was promoted. The intercellular space of the BW SC generated by emulsion-A was filled with multilamellar lipid sheets. The softness of the SC with a BW structure formed with emulsion-A was higher than that of the compact SC in RHE. The outermost SC Dsg1 degradation (formation of the BW SC as determined with Dsg1 pixels) was correlated with water-barrier functions and the SC softness of healthy human cheek, which varied widely.

CONCLUSIONS

Emulsion-A successfully generated the BW SC in RHE for the first time. This method is suggested to be a useful tool for investigating the physiological significance of the BW SC in vitro. Determination of Dsg1 content in the SC obtained by tape stripping from human skin allows study of the effects of external stimulants, such as creams and ointments, including cosmetics, on the completeness of the BW SC in situ without biopsy. What's already known about this topic? The normal stratum corneum (SC) has two layers, an upper basket-weave (BW) pattern layer and a lower compact layer. Epidermal diseases such as ichthyosis vulgaris and X-linked ichthyosis have an incomplete or no BW SC and impaired SC barrier functions, in which corneodesmosome (CD) degradation in a peripheral distribution is impaired. The roles of the BW SC in the physiological properties of human skin have not been clearly elucidated. What does this study add? Reconstructed human epidermis (RHE) with a complete BW structure was generated for the first time by treatment with oil-in-water emulsion-A. The formation of the BW SC was associated with a decrease in Dsg1 content, which represents the CD number in the SC. The intercellular space of the BW SC generated by emulsion-A, but not compact SC, was filled with multilamellar lipid sheets. The softness of the SC with a BW structure formed by emulsion-A treatment was higher than that of the compact SC in RHE. What is the translational message? RHE with a complete BW SC generated by emulsion-A treatment is suggested to be a useful tool for investigating effects on the physiological functions of the BW SC, as in treatments with creams and ointments including cosmetics. Determination of desmoglein 1 content in the SC obtained by tape stripping from human skin can make it possible to study the effects of external stimulants, such as creams and ointments, including cosmetics, on the completeness of the BW SC in situ without biopsy.

Evaluation of the safety and efficacy of Glycyrrhiza uralensis root extracts produced using artificial hydroponic and artificial hydroponic-field hybrid cultivation systems

Glycyrrhiza uralensis roots used in this study were produced using novel cultivation systems, including artificial hydroponics and artificial hydroponic-field hybrid cultivation. The equivalency between G. uralensis root extracts produced by hydroponics and/or hybrid cultivation and a commercial Glycyrrhiza crude drug were evaluated for both safety and efficacy, and there were no significant differences in terms of mutagenicity on the Ames tests. The levels of cadmium and mercury in both hydroponic roots and crude drugs were less than the limit of quantitation. Arsenic levels were lower in all hydroponic roots than in the crude drug, whereas mean lead levels in the crude drug were not significantly different from those in the hydroponically cultivated G. uralensis roots. Both hydroponic and hybrid-cultivated root extracts showed antiallergic activities against contact hypersensitivity that were similar to those of the crude drug extracts. These study results suggest that hydroponic and hybrid-cultivated roots are equivalent in safety and efficacy to those of commercial crude drugs. Further studies are necessary before the roots are applicable as replacements for the currently available commercial crude drugs produced from wild plant resources.

Production of viable seeds from the seedling lethal mutant ppi2-2 lacking the atToc159 chloroplast protein import receptor using plastic containers, and characterization of the homozygous mutant progeny

Biogenesis of chloroplasts is essential for plant growth and development. A number of homozygous mutants lacking a chloroplast protein exhibit an albino phenotype. In general, it is challenging to grow albino Arabidopsis plants on soil until they set seeds. Homozygous albino mutants are usually obtained as progenies of heterozygous parents. Here, we describe a method of recovering seeds from the seedling lethal Arabidopsis mutant ppi2-2, which lacks the atToc159 protein import receptor at the outer envelope membrane of chloroplast. Using plastic containers, we were able to grow homozygous ppi2-2 plants until these set seed. Although the germination rate of the harvested seeds was relatively low, it was still sufficient to allow us to further analyze the ppi2-2 progeny. Using ppi2-2 homozygous seeds, we were able to analyze the role of plastid protein import in the light-regulated induction of nuclear genes. We propose that this method be applied to other seedling lethal Arabidopsis mutants to obtain homozygous seeds, helping us further investigate the roles of plastid proteins in plant growth and development.

Factors influencing compliance with infection control practice in Japanese dentists

BACKGROUND

In recent years, dentists have more opportunity of treating patients infected with blood-borne pathogens. Although compliance with infection control practice (ICP) in dental practice is required, it is not still sufficiently spread in Japan.

OBJECTIVE

To identify factors associated with compliance with ICPs in the population of Japanese dentists.

METHODS

In a questionnaire-based cross-sectional study in 2009, 2134 dentists in Aichi prefecture, Japan, were surveyed. They were asked for their demographic characteristics, willingness to treat HIV/AIDS patients, and knowledge about universal/standard precautions and ICP.

RESULTS

Many ICP items had significant association with age, specialty for oral surgery, number of patients treated per day, willingness to treat HIV/AIDS patients and knowledge about the universal/standard precautions. In logistic regression model, knowledge about the precautions had significant associations with all ICP items. Among participants with disadvantageous characteristic group for ICP (ie, age ≥50 years, being general dentist, and treating ≤35 patients/day), knowledge about the universal/standard precautions had greater impact on exchanging handpiece for each patient and installing extra-oral vacuum in those with age of ≥50 years than in those who visited ≤35 patient per day.

CONCLUSION

Knowledge about the meaning of universal/standard precautions is the most significant predictor of compliance with ICPs among Japanese dentists.

Efficacy and safety of voriconazole in the treatment of chronic pulmonary aspergillosis: experience in Japan

BACKGROUND

Though various clinical conditions of aspergillosis can occur, depending essentially on the host's immunological status, the focus of research in North American and European countries has mainly been on invasive pulmonary aspergillosis in immunocompromised patients. There are, however, also many problems to overcome in chronic forms of aspergillosis. One of those problems is that there are no codified treatment guidelines for chronic pulmonary aspergillosis (CPA). Especially in Japan, this issue is more serious, because there are more cases with CPA due to the many aged people with past history of tuberculosis. Several clinical cases and case series have reported the usefulness of the various antifungal agents that are available. The new triazole, voriconazole, in particular, seems to be effective in the treatment of CPA. The aim of the present study is to evaluate the efficacy and safety of voriconazole in the treatment of CPA in non-immunocompromised patients.

PATIENTS AND METHODS

We conducted a prospective, open-label, non-comparative, multicenter study over a 2-year period. For inclusion in the study, patients with confirmed or probable CPA were recruited in 11 hospitals of the National Hospital Organization in Japan. Clinical, radiological, serological, and mycological data were collected at baseline and 12 weeks after treatment or at the end of treatment.

RESULTS

Among 77 patients enrolled in the study, 71 patients (mean age 65.9 years, 56 males and 15 females) were eligible for the study. All of the eligible patients presented with underlying lung diseases, including sequelae of tuberculosis (n = 35), non-tuberculous mycobacterial lung disease (n = 8), chronic obstructive pulmonary disease (COPD) (n = 8), interstitial pneumonia (n = 7), cystic lung disease (n = 4), pneumothorax (n = 3), bronchial cancer (n = 1), and others (n = 5). Voriconazole was indicated in 48 cases (68 %) as the first-line treatment for CPA and 23 patients previously received other antifungal therapies. Based on a composite of clinical, radiologic, serological, and mycologic criteria, good response was seen in 43 patients (60.6 %), no response was observed in 19 patients (26.8 %), and 4 cases (5.6 %) got worse. Five patients (7.0 %) were unassessable for efficacy. The common adverse events were visual disturbances (17 patients, 23.9 %), abnormal liver function test results (12 patients, 16.9 %), adverse psychological effects (3 patients, 4.2 %), and others (10 patients, 14.0 %). Treatment with voriconazole had to be stopped in 2 cases (2.8 %) because of serious adverse events (abnormal liver function test results). There was no association between adverse effects and trough voriconazole levels in serum.

CONCLUSIONS

In Japan, voriconazole provides effective therapy of CPA in non-immunocompromised patients with an acceptable level of toxicity.

Attitudes about chemotherapy for Japanese patients with or without cancer: Doctors, nurses, and the general public

17062

Background: A prospective survey in England demonstrated that patients with cancer were much more likely to accept radical treatment with minimal chance of benefit than people who did not have cancer (Slevin et al. Br Med J 1990; 300: 1458–60). We compared responses of Japanese patients with cancer with those of a control group of physicians, nurses, and patients without cancer in assessing personal cost-benefit of chemotherapy using the same questionnaire with Slevin's study. Methods: Subjects were asked with questionnaires whether of not to accept intensive and mild chemotherapy with a supposed minimum chance of effectiveness. 153 patients with cancer, 265 controls, 213 doctors, 397 nurses, and 51 patients without cancer were subjects of the study. Results: Percentage of subjects who accepted intensive chemotherapy with a supposed minimum chance of effectiveness (1% chance of cure, 3-month prolonging life, 1% relief of symptoms) by subject group were as follows: cancer patients; 62/55/52, doctors; 27/32/4, nurses; 11/12/5, non-cancer patients; 35/40/36, controls; 23/24/15, respectively. Conclusions: More patients with cancer than people without cancer accepted treatments giving the minimal benefit for cure, prolonging life or palliation of symptoms. Interestingly, the results in Japanese survey were similar to the previous study in England.

No significant financial relationships to disclose.

Association between commensal bacteria and opportunistic pathogens in the dental plaque of elderly individuals

Opportunistic infections in the oral cavity of the elderly may increase the incidence of systemic disease. The objective of this study was to investigate the differences in the oral bacterial flora between dependent elderly (inpatients) and independent elderly (community-dwelling residents). After multiple variables were taken into account, inpatients had significantly lower detection rates than community-dwelling residents for alpha-streptococci (p < 0.001) and Neisseria (p 0.004), and higher detection rates for Pseudomonas aeruginosa (p 0.024), methicillin-resistant Staphylococcus aureus (MRSA) (p 0.011) and Actinomyces spp. (p 0.005). Among inpatients, the requirement for a high degree of care was related negatively to detection of alpha-streptococci, but was related significantly to detection of P. aeruginosa (p 0.018) or MRSA (p 0.004). Tube-fed inpatients had a significantly lower detection rate for alpha-streptococci (p 0.041) and a higher detection rate for P. aeruginosa (p 0.004) than those who did not require tube feeding. Inpatients with a history of antibiotic use had a significantly lower detection rate for alpha-streptococci (p 0.049) and a higher detection rate for MRSA (p 0.007) than those without a history of antibiotic use. The detection rates for P. aeruginosa or MRSA in inpatients without alpha-streptococci were higher than in inpatients with alpha-streptococci after controlling for age and gender (P. aeruginosa, p 0.006; MRSA, p 0.001). Overall, detection of alpha-streptococci had an inverse correlation with the detection of P. aeruginosa and MRSA in the oral cavity and is likely to be an indicator of pathogenic bacterial infection.

Post-operative infection by pathogenic micro-organisms in the oral cavity of patients with prostatic carcinoma

The aim of this study was to analyse the change in the oral cavity microflora of 14 patients who had undergone a radical prostatectomy for prostatic carcinoma. The detection of micro-organisms in the oral cavity was compared before and after the surgical procedure. Post-operative infection, defined as those patients who had increased Candida species counts and/or pathogenic bacteria only at the post-operative examination, was observed in 10 patients. Six patients showed increased Candida species counts at the post-operative examination compared with the pre-operative examination. In five patients, pathogenic bacterial species were detected at the post-operative examination but not at the pre-operative examination. One patient had detectable pathogenic bacterial species only at the post-operative examination along with increased Candida species counts. Our findings suggest that pre-operative oral hygiene to remove bacterial and Candida species from patients who are scheduled for surgical procedures is important for satisfactory clinical outcomes.

Activation of torularhodin production by Rhodotorula glutinis using weak white light irradiation

The effects of the irradiation of weak white light on the growth of the red yeast Rhodotorula glutinis and its production of carotenoids were investigated. The ability of beta-carotene and torularhodin, which are final products of carotenoid biosynthesis in R. glutinis, to quench singlet oxygen has also been investigated. Weak white light irradiation that has no effect on the growth of Saccharomyces cerevisiae inhibited the growth of R. glutinis. Simultaneously, the production of torularhodin by R. glutinis markedly increased. In a mutant of R. glutinis, which exhibited increased production of torularhodin, an increase in torularhodin production was shown as a result of light irradiation during the logarithmic growth phase. An experiment using 3-(1,4-epidioxyl-4-methyl-1,4-dehydro-1-naphtyl) propionic acid clarified that torularhodin inhibited 2,5-diphenyl-3,4-benzofran decomposition by singlet oxygen quenching more strongly than did beta-carotene. This result is consistent with the report that carotenoids having a longer polyene chain may exhibit a more potent ability to quench singlet oxygen. These results suggest that the biosynthesis of carotenoids in R. glutinis may play an important role in protecting against oxidative damage caused by light irradiation, and in particular, torularhodin which has a potent singlet oxygen quenching ability may be important. We suggest that acquisition of the ability to produce torularhodin may be an important property for this yeast to promote its wider distribution in the natural world.

Sexual differences in smoking behaviour and dental caries experience in young adults

Smokers have been reported to exhibit a low awareness of their health. However, oral health awareness in smokers has not been fully studied. Having adequate oral care and high awareness of oral health from youth is necessary to prevent the deterioration of oral health in middle and old age. The aim of this study was to investigate the oral health status and oral health behaviour in young smokers. A survey composed of a questionnaire and an oral examination was administrated to adults aged 20-29 y who consulted dentists. The relationship between smoking behaviour and oral health status and oral health behaviour in subjects was analysed. In women, though no significant relationship between smoking behaviour and the number of decayed, missing, and filled teeth was seen, current smokers had significantly more decayed teeth, missing teeth and fewer filled teeth than ex-smokers and non-smokers. Current smokers tended to practice less oral health behaviour than non-smokers. In men, there was no significant relationship between smoking behaviour and each oral health status item. These findings suggested that the smoking group had lower oral health awareness than the non-smoking group in women.

Oral bacteria influenced by the functional status of the elderly people and the type and quality of facilities for the bedridden

AIMS

To analyse the relationship between oral bacteria and the health and functional status of the elderly.

METHODS AND RESULTS

The bacteria species in the oral cavity of the elderly were examined. It was found that the bedridden subjects staying at two hospitals for long-term (HOBR) showed significantly lower detection rates of commensal bacteria species and significantly higher detection rates of Pseudomonas aeruginosa, of methicillin-resistant Staphylococcus aureus (MRSA) and of coagulase(-) Staph. aureus than those living independently (the independent). In addition, the detection rate of Haemophilus parainfluenzae in NUBR was discovered to be higher than that found in the independent. In HOBR, the detection rate of Ps. aeruginosa was significantly higher among in-patients who required continual care than those in need of partial care, while the detection rate of MRSA was significantly higher among in-patients with low serum albumin than those with normal serum albumin.

CONCLUSIONS

Oral bacteria examination analysis proved that the risks of infection of some pathogenic bacteria species were correlated with functional status, physical function and nutritional state.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study suggests that the oral bacteria, especially pathogenic bacteria were influenced by the functional status of the elderly and the type and quality of the facilities for the bedridden, physical function and nutritional state.

Synthesis of 2-phenylbenzotriazole-type mutagens, PBTA-5 and PBTA-6, and their detection in river water from Japan

We previously determined the chemical structures of four 2-phenylbenzotriazole mutagens (PBTA-1, -2, -3 and -4) in blue rayon-adsorbed material from the Nishitakase River in Kyoto prefecture and the Nikko River in Aichi prefecture in Japan. On the basis of a synthesis study, these four PBTA derivatives were deduced to have originated from corresponding dinitrophenylazo dyes by reduction and chlorination. 2-[(2-Bromo-4,6-dinitrophenyl)azo]-5-[bis(2-acetoxyethyl) amino]-4-methoxyacetanilide (Color Index Name, Disperse Blue 79:1; CAS Registry Number, 75497-74-4) is a very common dinitrophenylazo dye used in textile dyeing factories. In the present study, we synthesized 2-[4-[bis(2-acetoxyethyl)amino]-2-(acetylamino)-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-5) from Disperse Blue 79:1 by reduction with sodium hydrosulfite and subsequent chlorination with sodium hypochlorite. On hydrolysis of PBTA-5 with alkali, 2-[2-(acetylamino)-4-[bis(2-hydroxyethyl)amino]-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-6) was obtained. Both PBTA-5 and -6 were potent mutagens, inducing 723,000 revertants and 485,000 revertants per microgram of Salmonella typhimurium YG1024, respectively, in the presence of S9 mix. To clarify whether PBTA-5 and -6 exist in the environment, water samples were collected from five rivers flowing through regions where textile dyeing industries are developed. PBTA-6 was detected at levels of 3-134 ng/g blue rayon in all water samples that were examined. On the other hand, the amount of PBTA-5 in the samples was less than the detection limit.

[Pulmonary involvement, pleural effusion, and electrocardiographic abnormality in hypereosinophilic syndrome]

A 47-year-old man was admitted to our hospital with complaints of cough and shortness of breath. Chest radiography showed infiltration of the right lung and left pleural effusion, the eosinophil count increased notably in the peripheral blood, sputum, and pleural effusion. Transbronchial lung biopsy revealed the invasion of eosinophils like eosinophilic pneumonia. Heart failure easily developed in this patient after the intravenous infusion. Myocardial involvement was suspected, and hypereosinophilic syndrome was diagnosed. After prednisolone was administered, the peripheral blood eosinophil count normalized rapidly, and subsequently, the pleural effusion and infiltration shadows in the lung disappeared.

Manual control in space--research on perceptual-motor functions under zero gravity condition

Microgravity effects on human factor were studied through a series of manual control experiments conducted in the First Material Processing Test. The Japanese Payload Specialist operated a finger stick for 130 seconds to maintain a light spot movement around the center of a vertical LED array display. The stick angle is doubly integrated to make the controlled element motion. The light spot position indicates the difference between the motion and pseudo-random wave patterns which drives the man-machine tracking system. 24 runs were conducted in each of 2 months before launch, immediately pre-flight, and post-flight experiments. During the flight experiments, the PS felt pain in fast eye movement. He was obliged to fix his line of sight at the center of display and to watch the displayed error movement using peripheral view. He also felt difficulty in supporting his body against reaction force of his hand movement. During a few days after landing, disturbance was observed in the PS's posture. The operator describing function analysis revealed the disappearance of the "regression" phenomenon and increment of the effective time delay. As the result, the flight describing function showed better fit to the simplified model of lead with pure time delay.

The relationship between oral health status and biological and psychosocial function in the bedridden elderly

The present study was conducted in order to determine what item of biological and psychosocial function is related to oral health status in the bedridden elderly. The subjects were 94 elderly individuals (30 males, 64 females) who had been admitted to a nursing home in Chiba city, Japan. We assessed the number of remaining teeth and the number of functional teeth as oral health status variables. Biological and psychosocial function levels were determined using the functional independence measure method developed by the State University of New York at Buffalo. More than 70% of subjects had less than ten remaining teeth. Almost all subjects needed prosthesis treatment. More than 50% of subjects had 27 or less functional teeth. Mann-Whitney U-test and logistic regression models showed that 'expression' was concerned with the number of remaining teeth and 'bladder management', 'locomotion', 'transfers' were related to the number of functional teeth. These data suggest close relation between oral health status and biological and psychosocial function levels in the bedridden elderly.

Relationship between serum tumor necrosis factor-alpha and insulin resistance in obese men with Type 2 diabetes mellitus

We analyzed serum concentrations of tumor necrosis factor-alpha (TNF-alpha) for their role in insulin resistance in 12 obese men with untreated Type 2 diabetes mellitus and in 6 age-and BMI-matched obese controls. Insulin resistance was expressed using the homeostasis model assessment (HOMA-R). Six of the patients were insulin-resistant (HOMA-R>5.0), while six were not (HOMA-R</=3.0). Serum levels of TNF-alpha were higher in patients with insulin resistance (4.19+/-0.96 pg/ml) than in patients without insulin resistance (2.52+/-1.64 pg/ml) and in controls (2.03+/-1.21 pg/ml). Fasting serum concentrations of insulin and HOMA-R were higher in patients with insulin resistance (16.2+/-5.0 and 6.30+/-1.0 IU/ml, respectively) than in patients without insulin resistance (7.3+/-2.2 and 2.4+/-0.6 IU/ml) and in controls (8.0+/-2.9 and 1.8+/-0.6 IU/ml). These data suggest that high levels of serum TNF-alpha in patients with insulin resistance are related to high levels of fasting insulin and HOMA-R. We conclude that TNF-alpha may be involved in the pathogenesis of Type 2 diabetes mellitus in obese men. The importance of this investigation is that the subjects recruited in the study are BMI matched, because human obesity is associated with an increased TNF-alpha mRNA expression in adipose tissue.

Epstein-Barr virus associated diffuse large B-cell lymphoma complicated by autoimmune hemolytic anemia and pure red cell aplasia

A 53-year old man with systemic lymphadenopathy and hepatosplenomegaly was diagnosed with diffuse large B cell-lymphoma after inguinal lymph node biopsy. Anemia was noted, direct and indirect Coombs tests were positive, and the haptoglobin level was low. However, the bone marrow aspirate revealed erythroid aplasia. Co-existing autoimmune haemolytic anemia (AIHA) and pure red cell aplasia (PRCA) were diagnosed. In situ hybridization with Epstein-Barr virus (EBV) encoded small RNA (EBER) showed positive findings in lymphoma cells. Southern blot hybridization revealed immunoglobulin heavy chain gene rearrangement and a clonal EBV terminal repeat, indicating monoclonal proliferation of EBV in infected B cells. The patient was treated with CHOP, resulting in a complete remission (CR). AIHA and PRCA subsided after 3 courses of chemotherapy. In conclusion, this case demonstrates not only the association of B-cell lymphoma with autoimmune disorders but also the involvement of EBV in these conditions.

Chromosomal effects of newly identified water pollutants PBTA-1 and PBTA-2 and their possible mother compounds (azo dyes) and intermediates (non-ClPBTAs) in two Chinese hamster cell lines

We performed the in vitro micronucleus (MN) test on 2-[2-(acetylamino)-4-[bis(2-methoxyethyl)amino]-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-1) and 2-[2-(acetylamino)-4-[N-(2-cyanoethyl)-ethylamino]-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-2), which are newly identified water pollutants from the Nishitakase river in Kyoto, Japan, and on their possible mother compounds (AZO DYE) and intermediates (non-ClPBTAs). We tested these compounds in the absence and presence of S9 mix in two Chinese hamster cell lines CHL and V79-MZ and scored MN, polynuclear and karyorrhectic (PN), and mitotic (M) cells. PBTA-2 in the absence of S9 mix induced the strongest responses in both cell lines. It was also a strong inducer of binucleate cells in PN cells in both cell lines, which suggested that it induced polyploidy. PBTA-1 showed clear positive results only in the absence of S9 mix and only in V79-MZ cells, inducing aneuploidy. In CHL cells AZO DYE-1 significantly induced MN cells in the presence of S9 mix, and AZO DYE-2 induced MN and PN cells, including binucleate cells and cells with a multilobed nucleus, in the absence of S9 mix. In V79-MZ cells, AZO DYE-1 and -2 induced primarily M cells in the presence of S9 mix. 9% of the M cells treated with 50 microg/ml AZO DYE-1 showed endoreduplication. AZO DYE-2 at 200 microg/ml condensed the chromatin in 100% of the cells. The non-ClPBTAs were a bit more cytotoxic than the other compounds and induced a slight increase in MN cells in both cell lines. Some of the chemicals tested induced a characteristic karyomorphology that might reflect abnormal cell division. Abnormalities of cell division could be detected in PN and M cells as well as in MN cells. Structure-activity relationships have also been discussed.

Administration route-dependent vaccine efficiency of murine dendritic cells pulsed with antigens

Dendritic cells (DCs) loaded with tumour antigens have been successfully used to induce protective tumour immunity in murine models and human trials. However, it is still unclear which DC administration route elicits a superior therapeutic effect. Herein, we investigated the vaccine efficiency of DC2.4 cells, a murine dendritic cell line, pulsed with ovalbumin (OVA) in the murine E.G7-OVA tumour model after immunization via various routes. After a single vaccination using 1 x 10(6)OVA-pulsed DC2.4 cells, tumour was completely rejected in the intradermally (i.d.; three of four mice), subcutaneously (s.c.; three of four mice), and intraperitoneally (i.p.; one of four mice) immunized groups. Double vaccinations enhanced the anti-tumour effect in all groups except the intravenous (i.v.) group, which failed to achieve complete rejection. The anti-tumour efficacy of each immunization route was correlated with the OVA-specific cytotoxic T lymphocyte (CTL) activity evaluated on day 7 post-vaccination. Furthermore, the accumulation of DC2.4 cells in the regional lymph nodes was detected only in the i.d.-and s.c.-injected groups. These results demonstrate that the administration route of antigen-loaded DCs affects the migration of DCs to lymphoid tissues and the magnitude of antigen-specific CTL response. Furthermore, the immunization route affects vaccine efficiency.

Relationship between serum tumor necrosis factor-alpha and insulin resistance in obese men with Type 2 diabetes mellitus

We analyzed serum concentrations of tumor necrosis factor-alpha (TNF-alpha) for their role in insulin resistance in 12 obese men with untreated Type 2 diabetes mellitus and in 6 age-and BMI-matched obese controls. Insulin resistance was expressed using the homeostasis model assessment (HOMA-R). Six of the patients were insulin-resistant (HOMA-R>5.0), while six were not (HOMA-R</=3.0). Serum levels of TNF-alpha were higher in patients with insulin resistance (4.19+/-0.96 pg/ml) than in patients without insulin resistance (2.52+/-1.64 pg/ml) and in controls (2.03+/-1.21 pg/ml). Fasting serum concentrations of insulin and HOMA-R were higher in patients with insulin resistance (16.2+/-5.0 and 6.30+/-1.0 IU/ml, respectively) than in patients without insulin resistance (7.3+/-2.2 and 2.4+/-0.6 IU/ml) and in controls (8.0+/-2.9 and 1.8+/-0.6 IU/ml). These data suggest that high levels of serum TNF-alpha in patients with insulin resistance are related to high levels of fasting insulin and HOMA-R. We conclude that TNF-alpha may be involved in the pathogenesis of Type 2 diabetes mellitus in obese men. The importance of this investigation is that the subjects recruited in the study are BMI matched, because human obesity is associated with an increased TNF-alpha mRNA expression in adipose tissue.

Identification of 2-[2-(acetylamino)-4-amino-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-4) as a potent mutagen in river water in Kyoto and Aichi prefectures, Japan

We have previously isolated five mutagens in blue rayon-adsorbed substances from water at a site below sewage plants in the Nishitakase River, in Kyoto, Japan, and identified two of them as 2-phenylbenzotriazole derivatives, 2-[2-(acetylamino)-4-[bis(2-methoxyethyl)amino]-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-1) and 2-[2-(acetylamino)-4-[(2-cyanoethyl)ethylamino]-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-2). In the present study, we collected adsorbed materials on blue cotton (3 kg x 9 times) at the same location, and isolated a sufficient amount (97 microg) of one of the remaining three mutagens other than PBTA-1 and PBTA-2, for structural analysis, by multiple column chromatography. The structure of mutagen, accounting for 12% of the total mutagenicity of the blue rayon-adsorbed substances, was determined to be a PBTA-1 analogue, 2-[2-(acetylamino)-4-amino-5-methoxyphenyl]-5-amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-4). PBTA-4 is a potent mutagen, inducing 190,000 and 7,800,000 revertants of Salmonella typhimurium TA98 and YG1024 per microgram, respectively, in the presence of S9 mix. In addition to the water of the Nishitakase River, PBTA-4 was detected in water samples from two rivers that flow through other regions where textile-dyeing industries have been developed. Like other PBTA analogues, PBTA-4 might also be produced from azo dyes during industrial processes in dyeing factories and treatment at sewage plants.

The melanocortin-1 receptor is a key regulator of human cutaneous pigmentation

The cloning and characterization of the human melanocortin-1 receptor (MC1R) and the demonstration that normal human melanocytes respond to the melanocortins, alpha-melanocyte stimulating hormone (alpha-MSH) and adrenocorticotrophic hormone (ACTH), with increased proliferation and eumelanogenesis had put an end to a long-standing controversy about the role of melanocortins in regulating human cutaneous pigmentation. We have shown that alpha-MSH and ACTH bind the human MC1R with equal affinity, and are equipotent in their mitogenic and melanogenic effects on human melanocytes. We also showed that the activation of the MC1R is important for the melanogenic response of human melanocytes to ultraviolet radiation (UVR). The MC1R is also the principal mediator of the inhibitory effects of agouti signaling protein (ASP) on melanogenesis. Expression of the MC1R is subject to regulation by its own ligands alpha-MSH and ACTH, as well as by UVR and endothelin-1. Recent studies that we conducted on the expression of MC1R variants by human melanocytes and the implications of these variants on the function of the MC1R revealed the following. Human melanocytes homozygous for Arg160Trp mutation in the MC1R demonstrated a significantly reduced response to alpha-MSH. Also, this culture responded poorly to ASP and exhibited an exaggerated cytotoxic response to UVR. Another culture, which was homozygous for Val92Met mutation in the MC1R, demonstrated a normal response to alpha-MSH. Heterozygous mutations that are frequently expressed in various melanocyte cultures did not disrupt MC1R function. These results begin to elucidate the significance of MC1R variants in the function of the receptor. Our data emphasize the significance of a normally functioning MC1R in the response of melanocytes to melanocortins, ASP, and UVR.

[Comparison of in vitro antimicrobial activities of ofloxacin, levofloxacin, ciprofloxacin, and sparfloxacin against various mycobacteria]

In vitro antimicrobial activities of ofloxacin (OFLX), levofloxacin (LVFX), ciprofloxacin (CPFX), and sparfloxacin (SPFX) were compared against various mycobacteria using the agar dilution method with 7H11 medium, and the following results were obtained. (1) These four new quinolones showed excellent antimicrobial activities against M. tuberculosis, M. kansasii, and M. fortuitum. (2) SPFX was most active against slowly growing mycobacteria. The activity against M. tuberculosis was in the order of SPFX > CPFX > LVFX > OFLX. The activity against M. kansasii was in the order of SPFX > LVFX > OFLX > or = CPFX. (3) On the other hand, CPFX was most active against rapidly growing mycobacteria. The activity against M. fortuitum was in the order of CPFX > SPFX > LVFX > OFLX. Considering the in vitro antimicrobial activities and the pharmacokinetics of these four drugs, they could achieve favorable clinical outcomes for all the patients with pulmonary infection due to M. tuberculosis or M. fortuitum and some of the patients with pulmonary infection due to M. kansasii or M. chelonae.

Caries risk factors among three-year old children in Chiba, Japan

In order to predict the factors which affect the occurrence of dental caries in children after the age 18-months, we analyzed the relationship between the increment of the decayed, missing, and filled teeth (dmft) in children from 18-months to three-years of age and caries risk factors. Subjects were 392 infants who received both an 18-month-old check-up and a three-year-old check-up in Chiba city. Stepwise multiple logistic regression analyses were used to analyze the results with the increment of the dmft by various combinations of independent variables (sex, order of birth, sweets intake, beverage intake, tooth brushing and feeding). The most predictive factors for the increment of the dmft in upper anterior and molar were "breast feeding" and "bottle feeding" respectively. From these results, we concluded that bottle feeding and breast feeding were the risk factors for the increment of the dmft from the age of 18-months to three years.

[In vitro antimycobacterial activities of a new quinolone, balofloxacin]

Balofloxacin (BLFX), a newly developed fluoroquinolone, was studied for its in vitro antimycobacterial activity by the agar dilution method with 7H11 agar medium. The MIC90s were as follows: 0.39 microgram/ml for M. tuberculosis, > 50 micrograms/ml for M. avium, > 50 micrograms/ml for M. intracellulare, 0.39 microgram/ml for M. kansasii, 0.39 microgram/ml for M. fortuitum, > 50 micrograms/ml for M. abscessus, and 50 micrograms/ml for M. chelonae. The antimycobacterial activity of BLFX was comparable or slightly inferior to that of levofloxacin (LVFX). Considering the present findings and pharmacokinetics of BFLX, it appears that BFLX may achieve favorable outcome in the treatment of patients with infection due to M. tuberculosis, M. kansasii, or M. fortuitum similar to that of ofloxacin or LVFX.

[Improvement of a case of broncholithiasis after spontaneous lithoptysis]

A 53-year-old woman was admitted for recurrent hemoptysis and cough. The chest radiograph showed an infiltrative shadow in the left upper region. Chest tomogram and CT scan showed a small calcification and consolidation in the left upper lobe. Fiberoptic bronchoscopy revealed fresh hemorrhage from the left upper bronchus but no broncholith or bleeding point were detected. Since the symptoms had disappeared by 10 days after admission, the patient was discharged and followed up as an outpatient. Three weeks later, she spontaneously expectorated a stone 3 mm in maximum diameter, with an irregular surface. Analysis revealed that the stone's composition was 56% of calcium phosphate and 44% of calcium carbonate. Hemoptysis seemed to have been caused by the broncholith, which had originated as a calcification of a peribronchial lymph node that subsequently eroded its way into the airway. After lithoptysis, no recurrence has been observed.

Antagonistic effect of EGF against TGF beta1 on transformed phenotype and tropomyosin expression of human lung carcinoma A549 cells

TGF beta1 suppressed the colony forming ability of human lung carcinoma cell line, A549 cells in a dose-dependent manner. Accompanying these changes, the levels of the expression of high-molecular weight tropomyosin (TM) isoforms, especially TM1 and TM2, were significantly increased in the TGF beta1-treated A549 cells in a dose-dependent manner. When A549 cells were treated with TGF beta1 (2.5 pM) and EGF (1 nM) simultaneously, anchorage-independent growth of A549 cells was restored. In these cells, the expression of high-molecular weight TM decreased. The results suggest that the levels of the expression of high-molecular weight TM may be involved in antagonistic effects of EGF and TGF beta1 on the anchorage-independent growth of A549 cells.

Isolation and identification of a new 2-phenylbenzotriazole-type mutagen (PBTA-3) in the Nikko river in Aichi, Japan

We have previously determined the chemical structures of two 2-phenylbenzotriazole mutagens (PBTA-1 and PBTA-2) in blue cotton-adsorbed material from the Nishitakase River in Kyoto, Japan. In the present study, further analysis of mutagenic substances in the Nikko River, which flows through Aichi Prefecture in Japan, allowed the isolation of a new mutagen. Material (2.2 g) adsorbed on blue cotton (3 kg) at a site below the sewage plant on the Nikko River was purified by various column chromatographies, and a mutagen (120 microg) accounting for 11% of the total mutagenicity was isolated. On the basis of data from UV, mass, and (1)H NMR spectra of the mutagen, the compound was deduced to be a PBTA-1 analogue. As with PBTA-1, the mutagen was able to be synthesized from the azo dye 2-[(2-bromo-4, 6-dinitrophenyl)azo]-4-methoxy-5-[(2-hydroxyethyl)amino]acetanilide by reduction and chlorination. Since all spectra of the mutagen isolated from the river water were the same as those of the synthesized form, the structure was concluded to be 2-[2-(acetylamino)-4-[(2-hydroxyethyl)amino]-5-methoxyphenyl]-5-amino -7-bromo-4-chloro-2H-benzotriazole (PBTA-3). PBTA-3 is a potent mutagen, inducing 81 000 and 3 000 000 revertants per microgram of Salmonella typhimurium TA 98 and YG1024 respectively, in the presence of an S9 mix. In addition to its detection in the water of the Nikko River, PBTA-3 was detected in water samples from three other rivers flowing through regions where dyeing industries have been developed. Like PBTA-1 and PBTA-2, PBTA-3 might have also been produced from azo dyes during industrial processes in dyeing factories and/or through treatment at sewage plants.

The 2-phenylbenzotriazole-type water pollutant PBTA-2 has cytochalasin B-mimetic activity

The 2-phenylbenzotriazole (PBTA)-type water pollutant, 2-[2-(acetylamino)-4-[N-(2-cyanoethyl)ethylamino]-5-methoxyphenyl]-5- amino-7-bromo-4-chloro-2H-benzotriazole (PBTA-2), has been recently identified in samples from the Nishitakase River in Kyoto, Japan, and shows potent mutagenic activities in Salmonella typhimurium in the presence of a microsomal metabolizing system (S9 mix). In the present study, we conducted the in vitro micronucleus (MN) test on PBTA-2 in the absence and presence of S9 mix in two Chinese hamster cell lines, CHL and V79-MZ. In the MN test, PBTA-2 was weakly positive in CHL cells and strongly positive in V79-MZ cells. Because the positive results were accompanied by a statistically significant increase in the number of polynuclear (PN) and/or mitotic (M) cells, we examined treated cells in metaphase to see if numerical chromosome aberrations were being induced. We found that PBTA-2 induces polyploidy in both CHL and V79-MZ cells. A detailed analysis of MN preparations showed that in CHL cells, PBTA-2 predominantly induces equal-sized binucleated cells. Rhodamine phalloidin staining revealed that PBTA-2 causes actin filament abnormalities in both cell lines similar to those caused by cytochalasin B. Cytochalasin B induced PN cells predominantly and dose dependently, and almost all the cells were equal-sized and binucleate. The results suggest that PBTA-2 has cytochalasin B-mimetic activity, although agents affecting actin filaments, such as cytochalasins, phallotoxins and chloropeptide, have been derived only from molds so far. This study also suggests that our MN test protocol may be used to identify chemicals that have cytochalasin B-mimetic activity as well as those that induce numerical aberrations.