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Akahoya is a volcanic soil rich in alumina, primarily deposited in Kyushu, Japan. We have found that Akahoya adsorbs bacteria in the water surrounding cattle grazing areas, suggesting a potential for environmental purification. This study investigated the spectrum of microorganisms adsorbed by Akahoya using a column filled with Akahoya through which a suspension of microorganisms was passed. Shirasu soil, another volcanic soil with a different chemical composition, was used as a control. Akahoya effectively adsorbed a diverse range of microorganisms including Escherichia coli, Campylobacter jejuni, Vibrio parahaemolyticus, Salmonella Enteritidis, Staphylococcus aureus, Clostridium perfringens, spores of Bacillus subtilis and Bacillus anthracis, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), murine norovirus, and avian influenza virus (H3N2), whereas Shirasu soil did not adsorb any of the organisms examined. Moreover, bacteria naturally present in river water, such as aerobic bacteria, total coliforms, and Enterobacteriaceae as indicators of river contamination, as well as E. coli added artificially to sterilized river water, were reduced to below the detection limit (<1 CFU/mL) after being passed through Akahoya. Additionally, the number of viable E. coli continued to decrease after contact with Akahoya for 1 month, suggesting bactericidal effects. Notably, the adsorption of E. coli to Akahoya was influenced by the concentration of phosphate and the pH of the suspension due to the interaction between the surface phosphorylation of organisms and Al2O3, the major chemical component of Akahoya. The present results demonstrate the remarkable ability of Akahoya to remove phosphate and microbes, suggesting that Akahoya could be used for water purification processes.IMPORTANCEAlthough a safe and sufficient water supply is essential for the maintenance of hygienic conditions, a major challenge is to develop a comprehensive effective, sustainable, and cost-effective technological approach for the treatment and purification of contaminated water. In this study, we demonstrated that a novel volcanic soil, Akahoya, which has unlimited availability, is a highly effective adsorbent for a wide range of bacterial and viral pathogens, suggesting its potential as a sustainable resource for this purpose. It was suggested that the adsorption of microorganisms on Akahoya was mediated by phosphate groups present on the surface structures of microorganisms, which bind to the alumina component of Akahoya according to the phosphate concentration and pH of the liquid phase. The present findings highlight the exceptional ability of Akahoya to eliminate or reduce phosphate and microorganisms effectively in water purification processes, thus contributing to the development of efficient and sustainable solutions for addressing water pollution challenges.
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Bovine digital dermatitis (BDD) is an infectious skin disease of the hoof characterized by painful ulcerations that cause lameness in dairy cattle. Cell-free supernatants (CFS) of Falsiporphyromonas endometrii predominantly isolated from BDD lesions had the highest growth-stimulating effect on Treponema phagedenis among BDD-associated bacteria. Butyric acid was detected at a concentration of 45.4 mM in CFS of F. endometrii, and the growth of T. phagedenis was significantly promoted by butyric acid supplementation.
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Enfermedades de los Bovinos , Dermatitis Digital , Treponema , Animales , Bovinos , Treponema/aislamiento & purificación , Treponema/genética , Dermatitis Digital/microbiología , Enfermedades de los Bovinos/microbiología , Ácido Butírico/metabolismo , Infecciones por Treponema/microbiología , Infecciones por Treponema/veterinariaRESUMEN
"Akahoya" is a volcanic soil classified as a special soil deposited in Kyushu, Japan. Many of its properties are not yet clearly understood. We found that Akahoya had the potential to adsorb bacteria in cattle feces, which prompted us to investigate its material properties and perform experiments to comprehensively evaluate its adsorption performance for various fine particles such as acidic and basic dyes, NOx/SOx gas, and phosphoric acid ions, in addition to bacteria. Akahoya had a very high specific surface area owing to the large number of nanometer-sized pores in its structure; it exhibited a high adsorption capacity for both NO2 and SO2. Regarding the zeta potential of Akahoya, the point of zero charge was approximately pH 7.0. The surface potential had a significant effect on the adsorption of acidic and basic dyes. Akahoya had a very high cation exchange capacity when the sample surface was negatively charged and a high anion exchange capacity when the sample surface was positively charged. Akahoya also exhibited a relatively high adsorption capacity for phosphoric acid because of its high level of Al2O3, and the immersion liquid had a very high Al ion concentration. Finally, filtration tests were performed on Escherichia coli suspension using a column filled with Akahoya or another volcanic soil sample. The results confirmed that the Escherichia coli adhered on the Akahoya sample. The results of the Escherichia coli release test, after the filtration test, suggested that this adhesion to Akahoya could be phosphorus-mediated.
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Non-healing claw lesions (NHCLs) are a newly characterized disorder affecting the deep dermis of the hoof in dairy cattle. Although NHCLs are thought to be associated with bovine digital dermatitis (BDD), their precise etiology is not yet understood. To investigate the bacterial populations present in each type of NHCL (toe necrosis: TN, non-healing white line disease: nhWLD, and a non-healing sole ulcer: nhSU), and the newly added entity non-healing verrucous-like lesions (nhVLL), 16S rRNA-based metagenomic analysis with next-generation sequencing (NGS) was employed. Twelve cases of NHCLs (3 TN, 3 nhWLD, 4 nhSU, and 2 nhVLL) were collected from five dairy farms in two prefectures in Japan. Three samples of healthy hoof dermis collected from two farms and a slaughterhouse were used as controls. Furthermore, culture-dependent and -independent approaches were conducted for detecting Treponema species and Fusobacterium necrophorum. As reported in BDD, Treponema species and F. necrophorum were detected frequently from NHCLs by PCR and immunohistochemistry, but NGS showed that these bacterial genera were not predominant in NHCLs. The predominant bacterial genera in NHCLs differed among the lesions examined, suggesting that Treponema species present predominantly in BDD were not predominant in NHCLs and that the bacterial population in NHCLs may vary among individual cattle and/or farms.
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This study examines the association between abnormal cervical cytology and subjective health in pregnant women, as an adjunct to the Japan Environment and Children's Study, which cross-sectionally analyzed a subset of the prospective cohort. A total of 3024 pregnant women at a childbirth facility whose medical records of cervical cytology in the first trimester of pregnancy were transcribed and who responded to the subjective health questionnaire were included herein. They were classified into excellent, good, fair, and poor groups based on their subjective health. Cervical cytology results obtained from perinatal medical records were classified into normal and abnormal cytology based on the Bethesda classification. Logistic regression analysis adjusted for baseline characteristics, including age, pre-pregnancy body mass index, parity, and other possible confounding factors, was used. Of 3024 pregnant women, 106 (3.5%) had abnormal cytology, with the prevalence being 1.3%, 3.7%, 3.9%, and 4.0%, respectively (p = 0.055) in the poor, fair, good, and excellent groups. The baseline characteristics, namely age, history of gynecological diseases, Kessler 6-item psychological distress scale score, and history of mental illness, were significantly different between groups. Compared to the poor group, the other three groups had a significantly higher abnormal cytology risk after adjusting for confounding factors (Fair: adjusted OR [aOR] = 3.6, 95% CI [1.0-12.1]; Good: aOR = 4.6 [1.3-15.5]; Excellent: aOR = 4.6 [1.2-17.8]). This study encourages young women to undergo cervical cancer screening because they are at risk for cervical cancer even if they think that they are healthy, and preventive activities like regular screening are essential.
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Workers in poultry abattoirs may be frequently exposed to Campylobacter jejuni, which is a leading cause of bacterial food poisoning in Japan. The present study was conducted to measure the titers of IgG and IgA antibodies against C. jejuni among 104 female workers in a chicken processing plant in Miyazaki prefecture, Japan. Information regarding habitual ingestion of raw chicken meat and potential occupational risk factors was collected using a questionnaire. Acid extracts of four C. jejuni strains representing the genotypes most dominant in Miyazaki were used as antigens. The levels of both immunoglobulins measured by ELISA were not correlated with ingestion of edible raw chicken meat, the amount consumed in one sitting, or its frequency. Although age was correlated with antibody levels, the length of employment was not. Furthermore, the IgG and IgA levels in workers at the evisceration step were significantly higher than those at other locations in the plant. To identify the bacterial proteins recognized by the workers' IgG and IgA antibodies, Western blotting followed by LC/MS was conducted. Flagellin was identified as the common protein recognized in the sera of workers for whom ELISA demonstrated both the highest and lowest antibody levels. We concluded that the titers of IgG and IgA against C. jejuni in workers at the processing plant had been increased by occupational exposure to Campylobacter, regardless of raw chicken meat ingestion.
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Campylobacter jejuni , Animales , Pollos , Ingestión de Alimentos , Femenino , Japón , CarneRESUMEN
Although the addition of bevacizumab to platinum-based combination chemotherapy has been recommended as a standard regimen for patients with advanced or recurrent cervical cancer, there is no clear evidence regarding the effectiveness of bevacizumab monotherapy as salvage chemotherapy. This study prospectively examined the efficacy and safety of switching from platinum-based chemotherapy combined with bevacizumab to single maintenance therapy in patients with advanced or recurrent cervical cancer. Patients were first treated with standard combination chemotherapy. However, if chemotherapy was discontinued because of an adverse event, bevacizumab monotherapy was continued for patients who agreed to participate in this study and provided written informed consent. The study protocol was approved by the Independent Review Board of Tohoku University School of Medicine (reception number 2017-1-540). A total of 15 patients (median age of 55 years, range 33-69 years) participated in this study. The median number of cycles of bevacizumab single maintenance administration was 8, and the main reasons for discontinuation were disease progression and adverse events. Bevacizumab single maintenance therapy had a disease control rate of 53.3% (CR 40%, PR 6.7%, SD 6.7%). The most frequent grade 3/4 clinical adverse events were proteinuria (5/15) and hypertension (4/15). No treatment-related deaths occurred. Bevacizumab single maintenance therapy was effective as salvage chemotherapy in patients with advanced or recurrent cervical cancer, and the safety profile was generally consistent with those reported in previous studies of bevacizumab monotherapy.
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Neoplasias del Cuello Uterino , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bevacizumab/efectos adversos , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/tratamiento farmacológico , Proyectos Piloto , Platino (Metal)/uso terapéutico , Estudios Prospectivos , Neoplasias del Cuello Uterino/tratamiento farmacológicoRESUMEN
BACKGROUND: The purpose of this study was to clarify the practical clinical treatment for acute carbon monoxide (CO) poisoning in Japan and to investigate the efficacy of hyperbaric oxygen (HBO2) therapy in preventing delayed neurological sequelae (DNS) in the acute phase of CO poisoning. METHODS: We conducted a multicenter, prospective, observational study of acute CO poisoning in Japan. Patients with acute CO poisoning were enrolled and their treatment details were recorded. The primary endpoint was the onset of DNS within 2 months of CO exposure. Factors associated with DNS were assessed with logistic regression analysis. RESULTS: A total of 311 patients from 57 institutions were registered and 255 were analyzed: 171 received HBO2 therapy (HBO2 group) and 84 did not (normobaric oxygen [NBO2] group). HBO2 therapy was performed zero, once, twice, or three times within the first 24 h in 1.8%, 55.9%, 30.9%, and 11.3% of the HBO2 group, respectively. The treatment pressure in the first HBO2 session was 2.8 ATA (47.9% of the HBO2 group), 2.0 ATA (41.8%), 2.5 ATA (7.9%), or another pressure (2.4%). The incidence of DNS was 13/171 (7.6%) in the HBO2 group and 3/84 (3.6%) in the NBO2 group (P = 0.212). The number of HBO2 sessions in the first 24 h was one of the factors associated with the incidence of DNS (odds ratio, 2.082; 95% confidence interval, 1.101-3.937; P = 0.024). CONCLUSIONS: The practical clinical treatment for acute CO poisoning, including HBO2 therapy, varied among the institutions participating in Japan. HBO2 therapy with inconsistent protocols showed no advantage over NBO2 therapy in preventing DNS. Multiple HBO2 sessions was associated with the incidence of DNS.
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Intoxicación por Monóxido de Carbono/complicaciones , Disfunción Cognitiva/prevención & control , Trastornos de la Conciencia/prevención & control , Cefalea/prevención & control , Oxigenoterapia Hiperbárica , Adulto , Anciano , Disfunción Cognitiva/etiología , Trastornos de la Conciencia/etiología , Progresión de la Enfermedad , Femenino , Cefalea/etiología , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Resultado del TratamientoRESUMEN
BACKGROUND: To examine changes in psychological distress prevalence among pregnant women in Miyagi Prefecture, which was directly affected by the Great East Japan Earthquake and tsunami, and compare it with the other, less damaged areas of Japan. METHODS: This study was conducted in conjunction with the Japan Environment and Children`s Study. We examined 76,152 pregnant women including 8270 in Miyagi Regional Center and 67,882 in 13 other regional centers from the all-birth fixed data of the Japan Environment and Children's Study. We then compared the prevalence and risk of distress in women in Miyagi Regional Center and women in the 13 regional centers for 3 years after the disaster. RESULTS: Women in the Miyagi Regional Center suffered more psychological distress than those in the 13 regional centers: OR 1.38 (95% CI, 1.03-1.87) to 1.92 (95% CI, 1.42-2.60). Additionally, women in the inland area had a consistently higher prevalence of psychological distress compared to those from the 13 regional centers: OR 1.67 (95% CI, 1.18-2.38) to 2.19 (95% CI, 1.60-2.99). CONCLUSIONS: The lack of pre-disaster data in the Japan Environment and Children's Study made it impossible to compare the incidence of psychological distress before and after the March 2011 Great East Japan Earthquake. However, 3 years after the Great East Japan Earthquake, the prevalence of pregnant women with psychological distress did not improve in Miyagi Regional Center. Further, the prevalence of mental illness in inland areas was consistently higher than that in the 13 regional centers after the disaster.
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Desastres , Terremotos , Complicaciones del Embarazo/epidemiología , Mujeres Embarazadas/psicología , Distrés Psicológico , Tsunamis , Adolescente , Adulto , Femenino , Humanos , Japón/epidemiología , Embarazo , Complicaciones del Embarazo/psicología , Prevalencia , Adulto JovenRESUMEN
AIMS: To investigate the associations between glycosylated hemoglobin (HbA1c) levels at less than 24 weeks of gestation and adverse pregnancy outcomes in Japan. METHODS: This was a prospective nationwide birth cohort study of 77,526 subjects with an HbA1c level of <6.5% (<48 mmol/mol) at less than 24 weeks of gestation. Associations of HbA1c level with adverse pregnancy outcomes were evaluated using multivariate analyses. RESULTS: The adjusted odds ratios per 1% (11 mmol/mol) increase in HbA1c level were 1.77 (95% confidence interval [CI]: 1.48-2.12) for hypertensive disorders of pregnancy; 1.78 (95% CI: 1.12-2.83) for placental abruption; 1.30 (95% CI: 1.12-1.50) for preterm birth; 2.11 (95% CI: 1.41-3.16) for very preterm birth; 1.49 (95% CI: 1.33-1.68) for low birth weight infants; 1.95 (95% CI: 1.42-2.70) for macrosomia; 1.23 (95% CI: 1.09-1.39) for small for gestational age; 1.15 (95% CI: 1.04-1.28) for large for gestational age; and 1.29 (95% CI: 1.20-1.39) for the composite adverse pregnancy outcome. CONCLUSIONS: The higher the HbA1c level, the higher the risk of adverse pregnancy outcomes in Japan. Further studies will be needed to determine prenatal management based on the HbA1c level in pregnant women with HbA1c <6.5% (<48 mmol/mol) at less than 24 weeks of gestation.
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Diabetes Gestacional/diagnóstico , Hemoglobina Glucada/metabolismo , Complicaciones del Embarazo/etiología , Adulto , Estudios de Cohortes , Diabetes Gestacional/patología , Femenino , Hemoglobina Glucada/análisis , Humanos , Recién Nacido , Japón , Embarazo , Resultado del Embarazo , Estudios ProspectivosRESUMEN
This study investigated the association between maternal home blood pressure (HBP) trajectory during pregnancy and infant birth weight. A total of 755 pregnant women were included in this prospective cohort study. A group-based trajectory model identified six trajectory groups for home systolic blood pressure (SBP), diastolic BP (DBP), and mean arterial pressure (MAP). Next, the association of HBP trajectory groups with infant birth weight was evaluated using a general linear model considering potential confounding factors. For home SBP and MAP, the trajectory groups with a low-steep J-curve, moderate J-curve, little high J-curve, and high J-curve were significantly associated with lower infant birth weight than the low-J-curve group. Among the trajectory groups for home DBP, the moderate-steep J-curve, little high J-curve, and high J-curve were significantly associated with lower infant birth weight than the group with low-J-curve. The effect sizes of the trajectory groups varied in infant birth weight from -0.21 standard deviations (SDs) (95% confidence interval (CI): -0.42 to -0.01 SD) to -1.13 SD (95% CI: -1.54 to -0.72 SD). In the analyses of infant birth weight in grams, effect sizes that were significantly associated with infant birth weight varied from -84 g (95% CI: -167 to -1 g) to -567 g (95% CI: -732 to -402 g). Trajectory groups with a moderate-reverse J-curve for home SBP, DBP, and MAP were not significantly associated with infant birth weight. Maternal HBP trajectory during pregnancy was an indicator of infant birth weight. Further studies evaluating the associations between HBP during pregnancy and other perinatal outcomes are needed.
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Peso al Nacer/fisiología , Presión Sanguínea/fisiología , Hipertensión Inducida en el Embarazo/fisiopatología , Adulto , Monitoreo Ambulatorio de la Presión Arterial , Femenino , Humanos , Recién Nacido , Masculino , Embarazo , Estudios Prospectivos , Adulto JovenRESUMEN
BACKGROUND: Recurrent infections of Helicobacter cinaedi are often reported, and long-term antimicrobial treatment is empirically recommended to prevent such infections. However, there have been no studies examining whether recurrent infections are relapses of former infections or reinfections with different clones. METHODS: A 69-year-old woman presented with recurrent H cinaedi bacteremia-associated cellulitis after a 51-day interval. We isolated 10 colonies from the blood cultures obtained during each of the 2 episodes and subjected them to whole-genome sequencing (WGS). High-confidence single-nucleotide polymorphisms (SNPs) were identified by an assembly based method. Heterogeneous SNP sites were identified by read mapping. The susceptibility of a representative isolate to 14 antimicrobials was also examined. RESULTS: Whole-genome sequence analysis revealed only 6 SNP sites among the 20 isolates at the whole-genome level. Based on the 6 SNPs, 5 within-host variants (referred to as genotypes) were identified. All 5 genotypes were detected in the first infection; however, only 2 genotypes were detected in the second infection. Although the H cinaedi clone showed a higher minimum inhibitory concentration to fluoroquinolones and macrolides and responsible mutations were identified, none of the 6 SNPs appeared related to additional resistance. CONCLUSIONS: The second infection analyzed here was a relapse of the first infection. A certain level of within-host genomic heterogeneity of the H cinaedi clone was already present in the first infection. Our results suggest the importance of longer treatment courses to eradicate H cinaedi for preventing the relapse of its infection.
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Campylobacter jejuni and C. coli are the leading causes of enteric infections in many developed countries. Healthy chickens are considered to act as reservoirs of campylobacters, as the organisms colonize the intestinal tract. Once infected birds enter a processing plant, contamination of chicken carcasses with campylobacters occurs over the entire skin during defeathering and evisceration due to leakage of crop and/or intestinal contents. Although the role of feather follicles in the contamination of chicken carcasses by campylobacters during processing is still debatable, it has been considered that the microorganisms would be entrapped and retained in the follicles due to the morphological changes resulting from defeathering and chilling. In the present study, we observed the morphology of feather follicles in chicken carcasses after defeathering and chilling. A total of 3,133 feather follicles were examined for morphological changes before and after chilling. Shortly after defeathering, most (91.5%) of the follicles were closed, whereas after chilling they were either closed (85.5%) or open (6%), although a small proportion of enlarged follicles became smaller or closed (2.6%). Moreover, 5.9% of the follicles that were slightly open became further enlarged after chilling. Furthermore, the proportion of enlarged feather follicles that became closed after chilling showed no discernible relationship with the degree of campylobacter contamination in different areas of the carcass skin, suggesting that campylobacters may not be confined to feather follicles as a result of the morphological changes attributable to defeathering and chilling.
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Campylobacter , Pollos/microbiología , Manipulación de Alimentos/métodos , Carne/microbiología , Piel/microbiología , Mataderos , Animales , Frío , Recuento de Colonia Microbiana , Plumas/microbiologíaRESUMEN
OBJECTIVES: The aim of this study is to determine the predictors of secondary tricuspid regurgitation after aortic valve replacement for aortic stenosis. METHODS: Seventy-one patients, who underwent aortic valve replacement for aortic stenosis at our institute from January 2006 to July 2011, were divided into two groups: an STR group, which included 15 patients with moderate or greater than moderate secondary tricuspid regurgitation at a follow-up visit and a control group. Echocardiography was performed before surgery, at discharge, and at a late follow-up visit (mean follow-up 36 ± 19 months, range 0-77). RESULTS: Preoperatively, the number of women (p < .01), body surface area (p < .001), and relative wall thickness (0.60 ± 0.15 vs 0.71 ± 0.13, p = .022) showed significant differences between the two groups. At a follow-up visit, moderate or severe mitral regurgitation (p = .0001) and severe diastolic dysfunction (p = .003) showed significant differences between the two groups. In the Cox regression analysis, moderate or severe mitral regurgitation at follow-up (p = .038, hazard ratio 4.394, 95% CI 1.085-17.791) was the only independent predictor of secondary tricuspid regurgitation. CONCLUSIONS: This study suggested that preoperative concentric myocardial hypertrophy and diastolic dysfunction were associated with development of the secondary tricuspid regurgitation at late follow-up.
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Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Prótesis Valvulares Cardíacas , Hipertrofia Ventricular Izquierda/complicaciones , Insuficiencia de la Válvula Tricúspide/etiología , Disfunción Ventricular Izquierda/complicaciones , Función Ventricular Izquierda/fisiología , Anciano , Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/fisiopatología , Diástole , Ecocardiografía , Femenino , Estudios de Seguimiento , Humanos , Hipertrofia Ventricular Izquierda/diagnóstico , Hipertrofia Ventricular Izquierda/fisiopatología , Masculino , Pronóstico , Estudios Retrospectivos , Factores de Tiempo , Insuficiencia de la Válvula Tricúspide/diagnóstico , Insuficiencia de la Válvula Tricúspide/fisiopatología , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/fisiopatologíaRESUMEN
Equine canker is a chronic pododermatitis of the hoof in horses. Although spirochetes are detectable histopathologically in the lesions, the precise etiology remains unclear. This study reports the 16S rRNA gene sequencing of randomly selected clones based on PCR with Treponema-specific primers, using the canker lesions from two horses and healthy frog and sole from a horse. A total of 114 clones were obtained from the lesions, but no clones were detected in the healthy hoof tissues. The clones from the canker lesions examined were grouped into 19 operational taxonomic units, such as treponemal phylotypes originating from papillomatous digital dermatitis lesions of dairy cattle and as-yet uncultured human oral treponemes, indicating the presence of multiple treponemes in the lesions.
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Dermatitis/veterinaria , Enfermedades del Pie/veterinaria , Enfermedades de los Caballos/microbiología , Filogenia , Treponema/aislamiento & purificación , Infecciones por Treponema/veterinaria , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , ADN Bacteriano/química , ADN Bacteriano/genética , Dermatitis/microbiología , Dermatitis/patología , Enfermedades del Pie/microbiología , Enfermedades del Pie/patología , Enfermedades de los Caballos/patología , Caballos , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa/veterinaria , ARN Ribosómico 16S/química , ARN Ribosómico 16S/genética , Alineación de Secuencia , Análisis de Secuencia de ADN , Treponema/genética , Infecciones por Treponema/microbiología , Infecciones por Treponema/patologíaRESUMEN
BACKGROUND: The intake of some benzoic acid-containing foods or drinks such as green tea and coffee is known to increase urinary hippuric acid (HA) concentrations, and, unless this can be accounted for, may result in false-positive findings during the biological monitoring of toluene exposure. AIMS: To investigate the influence of green tea and coffee ingestion on urinary HA concentrations. METHODS: Time-weighted average exposures to toluene were monitored by measuring urinary HA in 245 car painters in 2005 and again in 2006. Samples of both urine and blood were collected during work hours. All the participants were also asked about their alcohol intake, smoking and dietary and beverage habits, especially green tea and coffee. To clarify the relationship between green tea and coffee ingestion, workers were prohibited from consuming green tea and coffee for 1 day before the health check-up in 2006. RESULTS: The frequency of positive urinary HA concentrations (>1.0 g/l) in heavy consumers of green tea and/or coffee was significantly higher than that of the non-consumer or light consumers (OR 2.34, 95% CI 1.15-4.74). Prohibiting green tea and coffee ingestion was effective in decreasing the frequency of falsely elevated urinary HA concentrations (P < 0.01). CONCLUSIONS: The consumption of green tea and/or coffee can result in an overestimation of urinary HA concentrations and cause false-positive results during the biological monitoring of workers exposed to low doses of toluene.