Association between habitual hot spring bathing and depression in Japanese older adults: A retrospective study in Beppu

OBJECTIVES

Thermal therapy is used to manage various psychological diseases, such as depression. We investigated the relationship between hot spring bathing and depression in older adults using questionnaire responses.

DESIGN AND SETTING

We comprehensively evaluated the preventive effects of long-term hot spring bathing in 10429 adults aged ≥ 65 years in Beppu, Japan, by conducting a questionnaire study on the prevalence of depression (n = 219).

MAIN OUTCOME MEASURES

Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a multivariable logistic regression model for history of depression.

RESULTS

A separate multivariable logistic regression model for inference showed that female sex (OR, 1.56; 95 % CI, 1.17-2.08; p = 0.002), arrhythmia (OR, 1.73; 95 % CI, 1.18-2.52; p = 0.004), hyperlipidemia (OR, 1.63; 95 % CI, 1.14-2.32; p = 0.006), renal disease (OR, 2.26; 95 % CI, 1.36-3.75; p = 0.001), collagen disease (OR, 2.72; 95 % CI, 1.48-5.02; p = 0.001), allergy (OR, 1.97; 95 % CI, 1.27-3.04; p = 0.002), and habitual daily hot spring bathing (OR, 0.63; 95 % CI, 0.41-0.94; p = 0.027) were independently significantly associated with a history of depression.

CONCLUSIONS

We found an inverse relationship between habitual daily hot spring bathing and history of depression. Prospective randomized controlled trials on habitual daily hot spring bathing as a treatment for depression are warranted to investigate whether the use of hot springs can provide relief to those with psychiatric and mental health disorders.

Tea crude extracts effectively inactivate severe acute respiratory syndrome coronavirus 2

It is well known that black and green tea extracts, particularly polyphenols, have antimicrobial activity against various pathogenic microbes including viruses. However, there is limited data on the antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), which emerged rapidly in China in late 2019 and which has been responsible for coronavirus disease 2019 (COVID‐19) pandemic globally. In this study, 20 compounds and three extracts were obtained from black and green tea and found that three tea extracts showed significant antiviral activity against SARS‐CoV‐2, whereby the viral titre decreased about 5 logs TCID₅₀ per ml by 1·375 mg ml⁻¹ black tea extract and two‐fold diluted tea bag infusion obtained from black tea when incubated at 25°C for 10 s. However, when concentrations of black and green tea extracts were equally adjusted to 344 µg ml⁻¹, green tea extracts showed more antiviral activity against SARS‐CoV‐2. This simple and highly respected beverage may be a cheap and widely acceptable means to reduce SARS‐CoV‐2 viral burden in the mouth and upper gastrointestinal and respiratory tracts in developed as well as developing countries.

Chlorine dioxide is a more potent antiviral agent against SARS-CoV-2 than sodium hypochlorite

BACKGROUND

A new coronavirus (SARS-CoV-2) abruptly emerged in Wuhan, China, in 2019 and rapidly spread globally to cause the COVID-19 pandemic.

AIM

To examine the anti-SARS-CoV-2 activity of the potent disinfectant Cleverin, the major disinfecting component of which is chlorine dioxide (ClO₂); and to compare the results with that of sodium hypochlorite in the presence or absence of 0.5% or 1.0% foetal bovine serum (FBS).

METHODS

Concentrated SARS-CoV-2 viruses were treated with various concentrations of ClO₂ and sodium hypochlorite and 50% tissue culture infective dose was calcurated to evaluate the antiviral activity of each chemical.

FINDINGS

When SARS-CoV-2 viruses were treated with 0.8 ppm ClO₂ or sodium hypochlorite, viral titre was decreased only by 1 log₁₀ TCID₅₀/mL in 3 min. However, the viral titre was decreased by more than 4 log₁₀ TCID₅₀/mL when treated with 80 ppm of each chemical for 10 s regardless of presence or absence of FBS. It should be emphasized that treatment with 24 ppm of ClO₂ inactivated more than 99.99% SARS-CoV-2 within 10 s or 99.99% SARS-CoV-2 in 1 min in the presence of 0.5% or 1.0% FBS, respectively. By contrast, 24 ppm of sodium hypochlorite inactivated only 99% or 90% SARS-CoV-2 in 3 min under similar conditions. Notably, except for ClO₂, the other components of Cleverin such as sodium chlorite, decaglycerol monolaurate, and silicone showed no significant antiviral activity.

CONCLUSION

Altogether, the results strongly suggest that although ClO₂ and sodium hypochlorite are strong antiviral agents in absence of organic matter but in presence of organic matter, ClO₂ is a more potent antiviral agent against SARS-CoV-2 than sodium hypochlorite.

Linagliptin Ameliorates Hepatic Steatosis via Non-Canonical Mechanisms in Mice Treated with a Dual Inhibitor of Insulin Receptor and IGF-1 Receptor

Abnormal hepatic insulin signaling is a cause or consequence of hepatic steatosis. DPP-4 inhibitors might be protective against fatty liver. We previously reported that the systemic inhibition of insulin receptor (IR) and IGF-1 receptor (IGF1R) by the administration of OSI-906 (linsitinib), a dual IR/IGF1R inhibitor, induced glucose intolerance, hepatic steatosis, and lipoatrophy in mice. In the present study, we investigated the effects of a DPP-4 inhibitor, linagliptin, on hepatic steatosis in OSI-906-treated mice. Unlike high-fat diet-induced hepatic steatosis, OSI-906-induced hepatic steatosis is not characterized by elevations in inflammatory responses or oxidative stress levels. Linagliptin improved OSI-906-induced hepatic steatosis via an insulin-signaling-independent pathway, without altering glucose levels, free fatty acid levels, gluconeogenic gene expressions in the liver, or visceral fat atrophy. Hepatic quantitative proteomic and phosphoproteomic analyses revealed that perilipin-2 (PLIN2), major urinary protein 20 (MUP20), cytochrome P450 2b10 (CYP2B10), and nicotinamide N-methyltransferase (NNMT) are possibly involved in the process of the amelioration of hepatic steatosis by linagliptin. Thus, linagliptin improved hepatic steatosis induced by IR and IGF1R inhibition via a previously unknown mechanism that did not involve gluconeogenesis, lipogenesis, or inflammation, suggesting the non-canonical actions of DPP-4 inhibitors in the treatment of hepatic steatosis under insulin-resistant conditions.

A covalent small molecule inhibitor of glutamate-oxaloacetate transaminase 1 impairs pancreatic cancer growth

Metabolic programs are rewired in cancer cells to support survival and tumor growth. Among these, recent studies have demonstrated that glutamate-oxaloacetate transaminase 1 (GOT1) plays key roles in maintaining redox homeostasis and proliferation of pancreatic ductal adenocarcinomas (PDA). This suggests that small molecule inhibitors of GOT1 could have utility for the treatment of PDA. However, the development of GOT1 inhibitors has been challenging, and no compound has yet demonstrated selectivity for GOT1-dependent cell metabolism or selective growth inhibition of PDA cell lines. In contrast, potent inhibitors that covalently bind to the transaminase cofactor pyridoxal-5'-phosphate (PLP), within the active site of the enzyme, have been reported for kynurenine aminotransferase (KAT) and gamma-aminobutyric acid aminotransferase (GABA-AT). Given the drug discovery successes with these transaminases, we aimed to identify PLP-dependent suicide substrate-type GOT1 inhibitors. Here, we demonstrate that PF-04859989, a known KAT2 inhibitor, has PLP-dependent inhibitory activity against GOT1 and shows selective growth inhibition of PDA cell lines.

Asymmetric Phosphorus Incorporation in Homoepitaxial P-Doped (111) Diamond Revealed by Photoelectron Holography

Diamond has two crystallographically inequivalent sites in the unit cell. In doped diamond, dopant occupation in the two sites is expected to be equal. Nevertheless, preferential dopant occupation during growth under nonequilibrium conditions is of fundamental importance, for example, to enhance the properties of nitrogen-vacancy (N-V) centers; therefore, this is a promising candidate for a qubit. However, the lack of suitable experimental techniques has made it difficult to study the crystal- and chemical-site-resolved local structures of dopants. Here, we confirm the identity of two chemical sites with asymmetric dopant incorporation in the diamond structure, via the photoelectron holography (PEH) of heavily phosphorus (P)-doped diamond prepared by chemical vapor deposition. One is substitutionally incorporated P with preferential site occupations and the other can be attributed to a PV split vacancy complex with preferential orientation. The present study shows that PEH is a valuable technique to study the local structures around dopants with a resolution of crystallographically inequivalent but energetically equivalent sites/orientations. Such information provides strategies to improve the properties of dopant related-complexes in which alignment is crucial for sensing of magnetic field or quantum spin register using N-V centers in diamond.

The induced RNA-binding protein, HuR, targets 3'-UTR region of IL-6 mRNA and enhances its stabilization in periodontitis

RNA-binding proteins (RBPs) regulate mRNA stability by binding to the 3'-untranslated region (UTR) region of mRNA. Human antigen-R (HuR), one of the RBPs, is involved in the progression of diseases, such as rheumatoid arthritis, diabetes mellitus and some inflammatory diseases. Interleukin (IL)-6 is a major inflammatory cytokine regulated by HuR binding to mRNA. Periodontal disease (PD) is also an inflammatory disease caused by elevations in IL-6 following an infection by periodontopathogenic bacteria. The involvement of HuR in the progression of PD was assessed using in-vitro and in-vivo experiments. Immunohistochemistry of inflamed periodontal tissue showed strong staining of HuR in the epithelium and connective tissue. HuR mRNA and protein level was increased following stimulation with Porphyromonas gingivalis (Pg), one of the periodontopathogenic bacteria, lipopolysacchride (LPS)-derived from Pg (PgLPS) and tumour necrosis factor (TNF)-α in OBA-9, an immortalized human gingival epithelial cell. The luciferase activity of 3'-UTR of IL-6 mRNA was increased by TNF-α, Pg and PgLPS in OBA-9. Luciferase activity was also increased in HuR-over-expressing OBA-9 following a bacterial stimulation. Down-regulation of HuR by siRNA resulted in a decrease in mRNA expression and production of IL-6. In contrast, the over-expression of HuR increased IL-6 mRNA expression and production in OBA-9. The HuR inhibitor, quercetin, suppressed Pg-induced HuR mRNA expression and IL-6 production in OBA-9. An oral inoculation with quercetin also inhibited bone resorption in ligature-induced periodontitis model mice as a result of down-regulation of IL-6. These results show that HuR modulates inflammatory responses by regulating IL-6.

Calcineurin inhibitors exacerbate coronary arteritis via the MyD88 signalling pathway in a murine model of Kawasaki disease

Calcineurin inhibitors (CNIs) have been used off-label for the treatment of refractory Kawasaki disease (KD). However, it remains unknown whether CNIs show protective effects against the development of coronary artery lesions in KD patients. To investigate the effects of CNIs on coronary arteries and the mechanisms of their actions on coronary arteritis in a mouse model of KD, we performed experiments with FK565, a ligand of nucleotide-binding oligomerization domain-containing protein 1 (NOD1) in wild-type, severe combined immunodeficiency (SCID), caspase-associated recruitment domain 9 (CARD9)^-/- and myeloid differentiation primary response gene 88 (MyD88)^-/- mice. We also performed in-vitro studies with vascular and monocytic cells and vascular tissues. A histopathological analysis showed that both cyclosporin A and tacrolimus exacerbated the NOD1-mediated coronary arteritis in a dose-dependent manner. Cyclosporin A induced the exacerbation of coronary arteritis in mice only in high doses, while tacrolimus exacerbated it within the therapeutic range in humans. Similar effects were obtained in SCID and CARD9^-/- mice but not in MyD88^-/- mice. CNIs enhanced the expression of adhesion molecules by endothelial cells and the cytokine secretion by monocytic cells in our KD model. These data indicated that both vascular and monocytic cells were involved in the exacerbation of coronary arteritis. Activation of MyD88-dependent inflammatory signals in both vascular cells and macrophages appears to contribute to their adverse effects. Particular attention should be paid to the development of coronary artery lesions when using CNIs to treat refractory KD.

Genetic divergence with ongoing gene flow is maintained by the use of different hosts in phytophagous ladybird beetles genus Henosepilachna

Adaptation to different environments can promote population divergence via natural selection even in the presence of gene flow - a phenomenon that typically occurs during ecological speciation. To elucidate how natural selection promotes and maintains population divergence during speciation, we investigated the population genetic structure, degree of gene flow and heterogeneous genomic divergence in three closely related Japanese phytophagous ladybird beetles: Henosepilachna pustulosa, H. niponica and H. yasutomii. These species act as a generalist, a wild thistle (Cirsium spp.) specialist and a blue cohosh (Caulophyllum robustum) specialist, respectively, and their ranges differ accordingly. The two specialist species widely co-occur but are reproductively isolated solely due to their high specialization to a particular host plant. Genomewide amplified fragment-length polymorphism (AFLP) markers and mitochondrial cytochrome c oxidase subunit I (COI) gene sequences demonstrated obvious genomewide divergence associated with both geographic distance and ecological divergence. However, a hybridization assessment for both AFLP loci and the mitochondrial sequences revealed a certain degree of unidirectional gene flow between the two sympatric specialist species. Principal coordinates analysis (PCoA) based on all of the variable AFLP loci demonstrated that there are genetic similarities between populations from adjacent localities irrespective of the species (i.e. host range). However, a further comparative genome scan identified a few fractions of loci representing approximately 1% of all loci as different host-associated outliers. These results suggest that these three species had a complex origin, which could be obscured by current gene flow, and that ecological divergence can be maintained with only a small fraction of the genome is related to different host use even when there is a certain degree of gene flow between sympatric species pairs.

Virulence of acute hepatopancreatic necrosis disease PirAB-like relies on secreted proteins not on gene copy number

AIMS

To investigate the virulence of the Vp_PirAB-like genes in Vibrio parahaemolyticus- acute hepatopancreatic necrosis disease (AHPND)-causing strain and the factors that are associated with the virulence level.

METHODS AND RESULTS

The virulence of Vp_PirAB-like was examined using a non-virulent strain FP11 of V. parahaemolyticus transformed with a plasmid harbouring Vp_PirAB-like genes and then it was used to challenge shrimp Litopenaeus vannamei and Marsupenaeus japonicus. Both species experienced 100% mortality at 10 days post infection. Analysis of a mutant strain (E1M), that was originally identified as virulent strain (E1) but lost its virulence to L. vannamei, revealed that it lacked a part of the Vp_PirA-like gene and all of the Vp_PirB-like gene. The copy numbers of Vp_PirA-like and Vp_PirB-like genes varied among virulent strains and were not correlated with their virulence. In Western blotting, Vp_PirA-like and Vp_PirB-like proteins were detected in both the cell lysate and the culture supernatant. The strongest intensity of detecting band in the culture supernatant was observed in the strain that caused the highest mortality. The V. parahaemolyticus AHPND-causing strain, unlike the human tdh-positive strain, did not show any enterotoxicity.

CONCLUSION

Vibrio parahaemolyticus AHPND-causing strains secrete the Vp_PirA-like and Vp_PirB-like proteins during the growing phase. The amount of secreted proteins affects the shrimp mortality.

SIGNIFICANCE AND IMPACT OF THE STUDY

The secreted proteins of Vp_PirAB-like are key factors of virulence in the V. parahaemolyticus AHPND-causing strain, but not gene copy.

Kawasaki disease: a matter of innate immunity

Kawasaki disease (KD) is an acute systemic vasculitis of childhood that does not have a known cause or aetiology. The epidemiological features (existence of epidemics, community outbreaks and seasonality), unique age distribution and clinical symptoms and signs of KD suggest that the disease is caused by one or more infectious environmental triggers. However, KD is not transmitted person-to-person and does not occur in clusters within households, schools or nurseries. KD is a self-limited illness that is not associated with the production of autoantibodies or the deposition of immune complexes, and it rarely recurs. Regarding the underlying pathophysiology of KD, innate immune activity (the inflammasome) is believed to play a role in the development of KD vasculitis, based on the results of studies with animal models and the clinical and laboratory findings of KD patients. Animal studies have demonstrated that innate immune pathogen-associated molecular patterns (PAMPs) can cause vasculitis independently of acquired immunity and have provided valuable insights regarding the underlying mechanisms of this phenomenon. To validate this concept, we recently searched for KD-specific PAMPs and identified such molecules with high specificity and sensitivity. These molecules have structures similar to those of microbe-associated molecular patterns (MAMPs), as shown by liquid chromatography-tandem mass spectrometry. We propose herein that KD is an innate immune disorder resulting from the exposure of a genetically predisposed individual to microbe-derived innate immune stimulants and that it is not a typical infectious disease.

Emergent Embolization for Control of Massive Hemorrhage from a Splanchnic Artery with a New Coaxial Catheter System

Emergent superselective embolization with a 3.0 F (1 mm) coaxial catheter and a steerable guidewire was performed in 27 patients with massive hemorrhage from a small-caliber splanchnic artery. Eight patients had intraperitoneal hemorrhage, 3 had hemobilia, 9 had gastric hemorrhage, and 7 had intestinal hemorrhage. Out of 27 patients, 7 had hemorrhage from a splanchnic artery pseudoaneurysm. Complete cessation of bleeding was obtained in all patients initially, but in 3 patients gastric hemorrhage recurred later. Otherwise, there was no rebleeding nor any major complication such as marked infarction of tissue or misplacement of embolic materials. This coaxial catheter system was highly reliable for achieving superselective catheterization in small-caliber arteries, minimizing the volume of infarcted tissue and allowing maximal preservation of splanchnic organic function. We conclude that this system represents a major advance in interventional radiology.

Porphyromonas gingivalis infection exacerbates the onset of rheumatoid arthritis in SKG mice

Epidemiological studies have linked periodontitis to rheumatoid arthritis (RA). Porphyromonas gingivalis (Pg) was reported recently to produce citrullinated protein (CP) and increase anti-cyclic CP antibody (ACPA), both of which have been identified as causative factors of RA. In the present study, we determined the effects of Pg infection on the exacerbation of RA in a mouse model. RA model mice (SKG mice) were established by an intraperitoneal (i.p.) injection of laminarin (LA). Mice were divided into six groups, Ctrl (PBS injection), LA (LA injection), Pg/LA (Pg + LA injection), Pg (Pg injection), Ec/LA (Escherichia coli and LA injection) and Ec (E. coli injection). In order to evaluate RA, joint swelling by the arthritis score, bone morphology by microcomputed tomography (microCT), haematoxylin and eosin staining, ACPA, matrix metalloproteinase-3 (MMP-3) and cytokine level in serum by enzyme-linked immunosorbent assay were determined. Osteoclast differentiation from bone marrow mononuclear cells (BMCs) was examined to clarify the underlying mechanisms of RA. The presence of Pg and CP in joint tissue was also investigated. The arthritis score was threefold higher in the Pg/LA group than in the LA group. Severe bone destruction was observed in joint tissue of the Pg/LA group. A microCT analysis of the Pg/LA group revealed a decrease in bone density. ACPA, MMP-3, interleukin (IL)-2, IL-6, CXCL1 and macrophage inflammatory protein (MIP)-1α levels from the Pg/LA group were the highest. The osteoclastogenesis of BMCs was enhanced in the Pg/LA group. Furthermore, large amounts of Pg components and CP were detected in the Pg/LA group. In conclusion, Pg infection has the potential to exacerbate RA.

The host galaxy of a fast radio burst

In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy; we measure the galaxy's redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called 'missing baryons'. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts.

Atypical mycobacteriosis in two patients with rheumatoid arthritis

Abstract We report two cases of rheumatoid arthritis (RA) with atypical mycobacteriosis. Opportunistic infections are critical complications for rheumatic diseases. The use of steroids or immunosuppressants may increase the risk of opportunistic infections. However, these reports are rare in that they demonstrate atypical mycobacterial infections as complications of RA, even though no immunosuppressive agents were used. We discuss the characteristics of atypical mycobacterial infections of the lung in RA.

Pharmacological characterization of the novel γ-secretase modulator AS2715348, a potential therapy for Alzheimer's disease, in rodents and nonhuman primates

γ-Secretase is the enzyme responsible for the intramembranous proteolysis of various substrates, such as amyloid precursor protein (APP) and Notch. Amyloid-β peptide 42 (Aβ42) is produced through the sequential proteolytic cleavage of APP by β- and γ-secretase and causes the synaptic dysfunction associated with memory impairment in Alzheimer's disease. Here, we identified a novel cyclohexylamine-derived γ-secretase modulator, {(1R*,2S*,3R*)-3-[(cyclohexylmethyl)(3,3-dimethylbutyl)amino]-2-[4-(trifluoromethyl)phenyl]cyclohexyl}acetic acid (AS2715348), that may inhibit this pathological response. AS2715348 was seen to reduce both cell-free and cellular production of Aβ42 without increasing levels of APP β-carboxyl terminal fragment or inhibiting Notch signaling. Additionally, the compound increased Aβ38 production, suggesting a shift of the cleavage site in APP. The inhibitory potency of AS2715348 on endogenous Aβ42 production was similar across human, mouse, and rat cells. Oral administration with AS2715348 at 1 mg/kg and greater significantly reduced brain Aβ42 levels in rats, and no Notch-related toxicity was observed after 28-day treatment at 100 mg/kg. Further, AS2715348 significantly ameliorated cognitive deficits in APP-transgenic Tg2576 mice. Finally, AS2715348 significantly reduced brain Aβ42 levels in cynomolgus monkeys. These findings collectively show the promise for AS2715348 as a potential disease-modifying drug for Alzheimer's disease.

Simultaneous potentiometric determination of ClO(3)(-)-ClO(2)(-) and ClO(3)(-)-HClO by flow injection analysis using Fe(III)-Fe(II) potential buffer

A rapid potentiometric flow injection technique for the simultaneous determination of oxychlorine species such as ClO(3)(-)-ClO(2)(-) and ClO(3)(-)-HClO has been developed, using both a redox electrode detector and a Fe(III)-Fe(II) potential buffer solution containing chloride. The analytical method is based on the detection of a large transient potential change of the redox electrode due to chlorine generated via the reaction of the oxychlorine species with chloride in the potential buffer solution. The sensitivities to HClO and ClO(2)(-) obtained by the transient potential change were enhanced 700-800-fold over that using an equilibrium potential. The detection limit of the present method for HClO and ClO(2)(-) is as low as 5x10(-8) M with use of a 5x10(-4) M Fe(III)-1x10(-3) M Fe(II) buffer containing 0.3 M KCl and 0.5 M H(2)SO(4). On the other hand, sensitivity to ClO(3)(-) was low when a potential buffer solution containing 0.5 M H(2)SO(4) was used, but could be increased largely by increasing the acidity of the potential buffer. The detection limit for ClO(3)(-) was 2x10(-6) M with the use of a 5x10(-4) M Fe(III)-1x10(-3) M Fe(II) buffer containing 0.3 M KCl and 9 M H(2)SO(4). By utilizing the difference in reactivity of oxychlorine species with chloride in the potential buffer, a simultaneous determination method for a mixed solution of ClO(3)(-)-ClO(2)(-) or ClO(3)(-)-HClO was designed to detect, in a timely manner, a transient potential change with the use of two streams of potential buffers which contain different concentrations of sulfuric acid. Analytical concentration ranges of oxychlorine species were 2x10(-5)-2x10(-4) M for ClO(3)(-), and 1x10(-6)-1x10(-5) M for HClO and ClO(2)(-). The reproducibility of the present method was in the range 1.5-2.3%. The reaction mechanism for the transient potential change used in the present method is also discussed, based on the results of batchwise experiments. The simultaneous determination method was applied to the determination of oxychlorine species in a tap water sample, and was found to provide an analytical result for HClO, which was in good agreement with that obtained by the o-tolidine method and to provide a good recovery for ClO(3)(-) added to the sample.

Expression and analysis of a cytolethal distending toxin (cdt) gene operon in Campylobacter lari

The present study examines the expression of cytolethal distending toxin (cdt) gene encoding a cytotoxin in Campylobacter lari (n=6 urease-negative [UN] C. lari; n=4 urease-positive thermophilic Campylobacter [UPTC]). When reverse transcription polymerase chain reaction (RT-PCR) was carried out with 10 C. lari isolates using a primer pair to amplify the cdtB gene transcript segment, an approximate 260 bp RT-PCR amplicon was generated with all the isolates. In addition, cdtA, cdtB and cdtC gene operon was identified to be polycistronicly transcribed in the C. lari cells. The cdtB gene translation in the C. lari cells was also confirmed by Western blot analysis. Thus, the cdt gene operon in C. lari organisms, including UN C. lari and UPTC, was expressed at the transcriptional and translational levels in the cells. The present results suggest that all three cdt genes may be functional in the cells.

Adipogenesis of the mesenchymal stromal cells and bone oedema in rheumatoid arthritis

OBJECTIVES

Bone oedema is a pathological change in rheumatoid arthritis (RA) that is detectable by magnetic resonance imaging (MRI). Recent histological analyses revealed that a prominent feature of bone oedema is the replacement of adipose tissue with inflammatory cells. Here, we demonstrate the possible roles of mesenchymal stromal cells (MSCs) in bone oedema formation and the pathogenic potential of the cells in RA.

METHODS

Adipogenesis of bone marrow-derived human MSCs was induced by a standard adipogenic induction medium in the presence or absence of cytokines. The cytokine productions from MSCs were screened by an antibody array system and confirmed by ELISA. The migration assay was performed to determine the locomotive abilities of undifferentiated MSCs or MSCs after adipogenesis. The expression of α smooth muscle actin (SMA) and F-actin was examined by immunostaining and phalloidin staining, respectively.

RESULTS

TNF-α, interleukin (IL)-1β, IL-6, and TGF-β clearly inhibited the adipogenesis of MSCs. Production of IL-6 was markedly reduced, and IL-8 secretion was augmented in MSCs after adipogenesis. The mobility of MSCs after adipogenesis was clearly reduced in migration assays compared to that of undifferentiated MSCs. Consistent with these findings, SMA and F-actin expressions were clearly suppressed in MSCs committed to adipogenesis.

CONCLUSIONS

Our data suggest that the inflammatory milieu promotes bone oedema by blocking adipogenesis of MSCs. In bone oedema, the enhanced IL-6 production and the increased mobility of MSCs may contribute to the progression of RA. Therefore, bone oedema may be an important target lesion in the treatment of RA.

Comparative analysis of Campylobacter lari cytolethal distending toxin (CDT) effect on HeLa cells

We aimed to clarify if Campylobacter lari exerts a cytolethal distending toxin (CDT) effect on HeLa cells. Campylobacter cell lysates (CCLys) from C. jejuni 81-176 and urease-positive thermophilic Campylobacter (UPTC) CF89-12 and UPTC NCTC12893 isolates were shown to exert a CDT effect on HeLa cells with morphological changes examined by Giemsa staining and microscopy. However, Campylobacter lari JCM2530(T) isolate showed no effect. In addition, Campylobacter cell culture supernatant wash gave low or absent toxic effects with both C. jejuni and C. lari organisms. When western blot analysis was carried out to clarify if there was a CDTB effect in the CCLys and soluble fractions from Campylobacter isolates, which had a CDT effect on HeLa cells or did not have any effect, anti-recombinant CjCDTB antibodies identified an immunoreactively positive signal at around approximately 25 kDa on all the C. lari isolates examined, as well as the C. jejuni 81116 strain. Thus, all the Campylobacter isolates including those without any CDT effect were shown to express CDTB at the translational level.

QRDR mutations, efflux system & antimicrobial resistance genes in enterotoxigenic Escherichia coli isolated from an outbreak of diarrhoea in Ahmedabad, India

BACKGROUND & OBJECTIVES

Diverse mechanisms have been identified in enteric bacteria for their adaptation and survival against multiple classes of antimicrobial agents. Resistance of bacteria to the most effective fluoroquinolones have increasingly been reported in many countries. We have identified that most of the enterotoxigenic Escherichia coli (ETEC) were resistant to several antimicrobials in a diarrhoea outbreak at Ahmedabad during 2000. The present study was done to identify several genes responsible for antimicrobial resistance and mobile genetic elements in the ETEC strains.

METHODS

Seventeen ETEC strains isolated from diarrhoeal patients were included in this study. The antimicrobial resistance was confirmed by conventional disc diffusion method. PCR and DNA sequencing were performed for the identification of mutation in the quinolone resistance-determining regions (QRDRs). Efflux pump was tested by inhibiting the proton-motive force. DNA hybridization assay was made for the detection of integrase genes and the resistance gene cassettes were identified by direct sequencing of the PCR amplicons.

RESULTS

Majority of the ETEC had GyrA mutations at codons 83 and 87 and in ParC at codon 80. Six strains had an additional mutation in ParC at codon 108 and two had at position 84. Plasmid-borne qnr gene alleles that encode quinolone resistance were not detected but the newly described aac(6')-Ib-cr gene encoding a fluoroquinolne-modifying enzyme was detected in 64.7 per cent of the ETEC. Class 1 (intI1) and class 2 (intI2) integrons were detected in six (35.3%) and three (17.6%) strains, respectively. Four strains (23.5%) had both the classes of integrons. Sequence analysis revealed presence of dfrA17, aadA1, aadA5 in class 1, and dfrA1, sat1, aadA1 in class 2 integrons. In addition, the other resistance genes such as tet gene alleles (94.1%), catAI (70.6%), strA (58.8%), bla TEM-1 (35.2%), and aphA1-Ia (29.4%) were detected in most of the strains.

INTERPRETATION & CONCLUSIONS

Innate gene mutations and acquisition of multidrug resistance genes through mobile genetic elements might have contributed to the emergence of multidrug resistance (MDR) in ETEC. This study reinforces the necessity of utilizing molecular techniques in the epidemiological studies to understand the nature of resistance responsible for antimicrobial resistance in different species of pathogenic bacteria.

The Optical Resolution of Racemic Chlorpheniramine and Its Stereoselective Pharmacokinetics in Rat Plasma

An ovomucoid-conjugated column has been developed for the chiral stationary-phase liquid chromatographic resolution of racemic chlorpheniramine with a quantitation limit of 0·05 μg mL−1. The assay was used to study the stereoselective kinetics of chlorpheniramine enantiomers in rats. After bolus intravenous administration of racemic chlorpheniramine maleate (20 mg kg−1), plasma concentration of the (–)-form was higher than that of the (+)-form. In the elimination phase, the concentrations of (+)- and (–)-chlorpheniramine in the plasma declined biexponentially with half-lives of 18·2 and 50·0 min, respectively. Although there was no significant difference in blood-to-plasma concentration ratio of both enantiomers, the apparent total blood clearance of (+)-chlorpheniramine was twice as large as that of the (–)-isomer. Binding of (–)-chlorpheniramine to rat plasma protein was stronger than that of (+)-chlorpheniramine suggesting stereoselective pharmacokinetics may be due to a difference in the plasma protein binding.

Enantioselective Pharmacokinetics of α-Fluoromethylhistidine in Rats and Its Comparison with Histidine

The enantiomer-specific pharmacokinetics of histidine and its analogue, α-fluoromethylhistidine (FMH), were investigated in rats. After bolus intravenous administration of each enantiomer of histidine or FMH at a dose of 40·3 mg kg−1 as free base equivalents, the plasma concentrations of l-histidine, d-histidine, (S)-FMH and (R)-FMH decreased biexponentially with half-lives of 39·2, 20·8, 32·8 and 25·0 min, respectively, in the elimination phase. Although the concentration of l-histidine in the plasma was lower than that of d-histidine, there was no large difference in plasma concentration-time curves of the enantiomers of FMH. The apparent total clearance of l-histidine from rat plasma was about 4 times that of d-histidine or the enantiomers of FMH. l-Histidine was quickly transferred to the peripheral tissues where the concentrations also decrease biphasically. l-Histidine penetrated more rapidly into the brain than either its d-enantiomer or a compound closely related in structure such as FMH. However, the disappearance of l-histidine from the various brain regions was very rapid. In contrast, brain/plasma ratios of d-histidine and (S)-FMH increased continuously after injection of these compounds, indicating that d-histidine or (S)-FMH partitioned into the brain and was very slowly removed from the brain; (R)-FMH was not distributed to the brain. These results suggested stereoselectivity in disposition of histidine and FMH enantiomers in rats.

STM Observation on the Initial growth of Amorphous and Microcrystalline Silicon Films

Direct nanoscale observation on the nucleation and growth of hydrogenated amorphous and microcrystalline silicon on graphite substrates was made using scanning tunneling microscopy, atomic force microscopy, and Raman scattering spectroscopy. Nucleation of hydrogenated silicon clusters is initiated through the nucleation sites created by reactive hydrogen species coming from the source gas plasma. The difference in spatial distribution of nucleated clusters at the initial stage of deposition between a-Si:H and μc-Si:H is ascribed to the difference in the number density of nucleation sites which results in difference in the diffusion length of a SiH3 radical at the initial stage of deposition on the graphite substrate. The RMS roughness of μc-Si:H films is larger than that of a-Si:H when the film thickness is larger than 10 Å, which is opposite to the behavior at the initial nucleation stage on the graphite substrate.

Aquatic Ecosystems, Human Health, and Ecohydrology

This chapter treats two main topics: the relationship between human health, aquatic ecosystems, and water use; and the necessity of interdisciplinary approaches for the development of water management policies and disease control.

Main waterborne diseases, mostly affecting developing countries and relevant in terms of water management and changes in land use, such as malaria, schistosomiasis, or cholera, are discussed stressing links to the global water crisis. Also, the role of artificial and natural wetlands in influenza epidemics is treated. The effects of increasing water use and scarcity on human health are discussed considering historical and contemporary incidence of diarrheal diseases in European and South Asian megacities, relationships between dams and on waterborne diseases in Asia and Africa, and intensive agri- and aquaculture resulting in man-made ecotones, fragmented aquatic ecosystems, and pathogen mutations.

It is emphasized that the comprehension of the multiple interactions among changes in environmental settings, land use, and human health requires a new synthesis of ecohydrology, biomedical sciences, and water management for surveillance and control of waterborne diseases in basin-based, transboundary health systems. Surveillance systems should monitor changes in water management, ecotones, and hydrological cycles and shifts in, for example, the outbreak timing of strongly seasonal diseases. These indicators would provide criteria for the development of innovative water management policies, combining methods of vector control and the safe creation of water reservoirs, irrigation systems, and wetland habitats.