The effect of the sagittal plane osteotomy inclination on the posterior tibial slope in medial open wedge HTO: experimental study with a square column model.

BACKGROUND: Medial open-wedge high tibial osteotomy (HTO) is an effective and safe treatment method for medial osteoarthritis of the knee. However, unintended changes in the posterior tibial slope (PTS) may occur. Several factors cause PTS alterations after medial open-wedge HTO; however, research on sagittal-plane osteotomy inclination (SPOI) in relation to the PTS is sparse. The purpose of this study was to evaluate whether the SPOI affects changes in the PTS after medial open-wedge HTO. The hypothesis was that an SPOI parallel to the PTS causes no change in the PTS after medial open-wedge HTO. METHODS: A square column model with a 10° posterior slope was produced using two three-dimensional (3D) programs and a 3D printer. Then, a series of medial open-wedge HTO procedures was performed on the square column model through virtual simulation using the two 3D programs, and an actual simulation was conducted using a 3D printer, a testing machine and a measurement system. The SPOI was divided into four types: ① SPOI 20° (posterior-inclined 10° osteotomy), ② SPOI 10° (osteotomy parallel to posterior slope), ③ SPOI 0° (anterior-inclined 10° osteotomy), and ④ SPOI - 10° (anterior-inclined 20° osteotomy). The correction angle was increased at intervals of 5° from 0° to 30°. The change in posterior slope was measured in the sagittal plane. RESULTS: The posterior slope was increased in SPOI 20° (posterior-inclined 10° osteotomy), maintained in SPOI 10° (osteotomy parallel to posterior slope), and decreased in SPOI 0° (anterior-inclined 10° osteotomy) and SPOI - 10° (anterior-inclined 20° osteotomy) based on the correction angle. CONCLUSIONS: In this study using a square column model, the SPOI affected the change in the PTS, and an SPOI parallel to the PTS caused no change in the PTS after medial open-wedge HTO.

Real-Time Clinical Decision Support Based on Recurrent Neural Networks for In-Hospital Acute Kidney Injury: External Validation and Model Interpretation.

BACKGROUND: Acute kidney injury (AKI) is commonly encountered in clinical practice and is associated with poor patient outcomes and increased health care costs. Despite it posing significant challenges for clinicians, effective measures for AKI prediction and prevention are lacking. Previously published AKI prediction models mostly have a simple design without external validation. Furthermore, little is known about the process of linking model output and clinical decisions due to the black-box nature of neural network models. OBJECTIVE: We aimed to present an externally validated recurrent neural network (RNN)-based continuous prediction model for in-hospital AKI and show applicable model interpretations in relation to clinical decision support. METHODS: Study populations were all patients aged 18 years or older who were hospitalized for more than 48 hours between 2013 and 2017 in 2 tertiary hospitals in Korea (Seoul National University Bundang Hospital and Seoul National University Hospital). All demographic data, laboratory values, vital signs, and clinical conditions of patients were obtained from electronic health records of each hospital. We developed 2-stage hierarchical prediction models (model 1 and model 2) using RNN algorithms. The outcome variable for model 1 was the occurrence of AKI within 7 days from the present. Model 2 predicted the future trajectory of creatinine values up to 72 hours. The performance of each developed model was evaluated using the internal and external validation data sets. For the explainability of our models, different model-agnostic interpretation methods were used, including Shapley Additive Explanations, partial dependence plots, individual conditional expectation, and accumulated local effects plots. RESULTS: We included 69,081 patients in the training, 7675 in the internal validation, and 72,352 in the external validation cohorts for model development after excluding cases with missing data and those with an estimated glomerular filtration rate less than 15 mL/min/1.73 m2 or end-stage kidney disease. Model 1 predicted any AKI development with an area under the receiver operating characteristic curve (AUC) of 0.88 (internal validation) and 0.84 (external validation), and stage 2 or higher AKI development with an AUC of 0.93 (internal validation) and 0.90 (external validation). Model 2 predicted the future creatinine values within 3 days with mean-squared errors of 0.04-0.09 for patients with higher risks of AKI and 0.03-0.08 for those with lower risks. Based on the developed models, we showed AKI probability according to feature values in total patients and each individual with partial dependence, accumulated local effects, and individual conditional expectation plots. We also estimated the effects of feature modifications such as nephrotoxic drug discontinuation on future creatinine levels. CONCLUSIONS: We developed and externally validated a continuous AKI prediction model using RNN algorithms. Our model could provide real-time assessment of future AKI occurrences and individualized risk factors for AKI in general inpatient cohorts; thus, we suggest approaches to support clinical decisions based on prediction models for in-hospital AKI.

Role of Human Primary Renal Fibroblast in TGF-ß1-Mediated Fibrosis-Mimicking Devices.

Renal fibrosis is a progressive chronic kidney disease that ultimately leads to end-stage renal failure. Despite several approaches to combat renal fibrosis, an experimental model to evaluate currently available drugs is not ideal. We developed fibrosis-mimicking models using three-dimensional (3D) co-culture devices designed with three separate layers of tubule interstitium, namely, epithelial, fibroblastic, and endothelial layers. We introduced human renal proximal tubular epithelial cells (HK-2), human umbilical-vein endothelial cells, and patient-derived renal fibroblasts, and evaluated the effects of transforming growth factor-ß (TGF-ß) and TGF-ß inhibitor treatment on this renal fibrosis model. The expression of the fibrosis marker alpha smooth muscle actin upon TGF-ß1 treatment was augmented in monolayer-cultured HK-2 cells in a 3D disease model. In the vascular compartment of renal fibrosis models, the density of vessels was increased and decreased in the TGF-ß-treated group and TGF-ß-inhibitor treatment group, respectively. Multiplex ELISA using supernatants in the TGF-ß-stimulating 3D models showed that pro-inflammatory cytokine and growth factor levels including interleukin-1 beta, tumor necrosis factor alpha, basic fibroblast growth factor, and TGF-ß1, TGF-ß2, and TGF-ß3 were increased, which mimicked the fibrotic microenvironments of human kidneys. This study may enable the construction of a human renal fibrosis-mimicking device model beyond traditional culture experiments.

Cancer development and mortality differences in patients with glomerulonephritis after renal biopsy: a single center retrospective cohort study.

BACKGROUND: The association between glomerulonephritis (GN) and cancer has been well known for decades. However, studies evaluating long-term de novo cancer development in patients with GN are limited. This study aimed to evaluate the incidence of cancer development among patients with renal biopsy-proven GN during post-biopsy follow-up and the differences in outcomes according to cancer occurrence. METHODS: We conducted a retrospective cohort study of adult patients who underwent renal biopsy at Seoul National Bundang Hospital between 2003 and 2017. After excluding 778 patients with age < 18 years, cancer diagnosis before or within 6 months after renal biopsy, immunosuppressant therapy before renal biopsy, or pathologic diagnoses other than GN, 822 patients were included in the analysis. Data on baseline clinical characteristics, renal biopsy results, and types and doses of immunosuppressant agents were collected from electronic medical records. The incidence of cancer was censored on the date when the first cancer was diagnosed. We evaluated rates of mortality and end-stage renal disease (ESRD) development during follow-up. RESULTS: During a mean follow-up period of 58.9 ± 44.5 months, 45 subjects (5.5%) developed de novo cancer. A comparison of clinical characteristics between subjects who did and did not develop cancer revealed that cancer patients were older and had higher comorbidities and immunosuppressant use. Overall, patients with GN had an elevated standardized incidence ratio (SIR) of 7.16 (95% confidence interval (CI): 5.22-9.61) relative to the age- and sex-matched general population. In particular, the SIR was significantly higher in GNs such as membranous nephropathy (MN), IgA nephropathy, lupus nephritis, and focal segmental glomerulosclerosis. Multivariable Cox proportional hazard model revealed that patients with MN had an increased risk of cancer development, with a hazard ratio of 2.30 [95% CI: 1.06-4.98]. Patients with MN who developed cancer had a significantly higher risk of mortality (hazard ratio: 6.59; 95% CI: 1.22-35.56, P = 0.03) than those without cancer, but there was a non-significant difference in ESRD development. CONCLUSIONS: Patients with GN without concurrent cancer, particularly those with MN, have significantly higher risks of cancer development and subsequent mortality and should remain aware of the potential development of malignancy during follow-up.

Association between Serum Uric Acid Level and ESRD or Death in a Korean Population.

BACKGROUND: Serum uric acid (SUA) is recognized as a risk factor for chronic kidney disease (CKD) and mortality. However, there is controversy as to whether a high or low level of SUA is related to the risk of CKD progression or death, and whether it differs between males and females. METHODS: We included 143,762 adults who underwent voluntary health screening between 1995 and 2009 in Korea. For each sex, we divided participants into sex-specific quintiles according to SUA levels and compared end-stage renal disease (ESRD) incidence and mortality between the groups with low and high SUA levels and those with middle SUA levels. Sex-specific Cox proportional hazard analyses were performed for ESRD and all-cause mortality. RESULTS: Among the 143,762 participants, 0.2% (n = 272) developed ESRD. The hazard ratio (HR) of ESRD was higher in the highest (adjusted HR, 2.13; 95% confidence interval [CI], 1.18-3.84) and lowest (adjusted HR, 1.90; 95% CI, 1.02-3.51) SUA quintiles than in the middle SUA quintile in males and the highest SUA quintile in females (adjusted HR, 2.31; 95% CI, 1.10-4.84). Four-point three percent (n = 6,215) of participants died during a mean follow-up period of 157 months. The hazard ratio (HR) of all-cause mortality was higher in the highest SUA quintile than in the middle SUA quintile in males (adjusted HR, 1.15; 95% CI, 1.03-1.28) and females (adjusted HR, 1.17; 95% CI, 1.01-1.35). CONCLUSION: Elevated levels of SUA are associated with increased risk for ESRD and all-cause mortality in both sexes. Low levels of SUA might be related to ESRD and death only in males, showing U-shaped associations. Our findings suggest sex-specific associations between SUA levels and ESRD development and mortality.

Effect of rifampin on enantioselective disposition and anti-hypertensive effect of benidipine.

AIMS: In vitro study showed that benidipine is exclusively metabolized by cytochrome P450 (CYP) 3A. This study evaluated the effect of rifampin on the enantioselective disposition and anti-hypertensive effect of benidipine. METHODS: Benidipine (8 mg) was administered to healthy subjects with or without repeated rifampin dosing, in a crossover design. Plasma concentrations of (S)-(S)-(+)-α and (R)-(R)-(-)-α isomers of benidipine and blood pressure were measured for up to 24 h after dosing. In addition, CYP3A metabolic capacity was evaluated in each subject using oral clearance of midazolam. RESULTS: The exposure of (S)-(S)-(+)-α-benidipine was greater than that of (R)-(R)-(-)-α-benidipine by approximately three-fold following single dose of benidipine. Repeated doses of rifampin significantly decreased the exposure of both isomers. Geometric mean ratios (GMRs) (95% CI) of Cmax and AUC∞ for (S)-(S)-(+)-α-benidipine were 0.14 (0.10-0.18) and 0.12 (0.08-0.18), respectively. GMRs (95% CI) of Cmax and AUC∞ for (R)-(R)-(-)-α-benidipine were 0.10 (0.06-0.17) and 0.10 (0.06-0.17), respectively. Oral clearances of both isomers were increased equally by approximately 10-fold. There were no significant differences in cardiovascular effect following benidipine administration between control and rifampin treatment. CYP3A activity using midazolam did not appear to correlate with oral clearance of benidipine. CONCLUSIONS: After single administration of racemic benidipine, enantioselective disposition of (S)-(S)-(+)-α- and (R)-(R)-(-)-α-benidipine was observed. Treatments with rifampin significantly decreased the exposure of both isomers but appeared to marginally affect its blood pressure-lowering effect in healthy subjects. Impact of coadministration of rifampin on the treatment effects of benidipine should be assessed in hypertensive patients.

Blood lead concentration and exposure related factors in Korea from the National Environmental Health Survey (KoNEHS) II (2012-2014).

This study evaluated lead concentrations in blood and related factors among the South Korean population based on data from the Korea National Environmental Health Survey (KoNEHS) II (2012-2014) conducted by the National Institute of Environmental Research and the Ministry of Environment. Personal data were obtained from non-institutionalized civilian Korean individuals in an interview with trained community surveyors using a structured questionnaire (n = 6,455, aged 19 or older, mean age 49.7 years). The lead concentrations in whole blood were analyzed by atomic absorption spectrophotometry (AAS) with a Zeeman-effect-based background corrector. The precision and accuracy of the analytical methods were verified by internal and external quality controls (G-EQUAS, Germany). Statistical analysis was performed using weighted KoNEHS II data separated by sex, and the lead concentration was expressed as a geometric mean (GM). Multiple linear regression was performed using the SPSS 23.0 software package (SPSS Inc., Chicago, IL, USA). The total GM of lead concentrations was 19.5 µg/L. Lead concentrations increased with age and were higher in males (22.8 µg/L) than in females (16.6 µg/L). Smokers and drinkers had higher concentrations than non-smokers and non-drinkers of both sexes. People who used herbal medications had higher concentrations than those who did not among females. People of both sexes living in rural areas had higher lead concentrations than those in urban areas. Lead concentrations also varied with educational level, total family income, the type of water regularly consumed, and occupation. The average lead concentration of the general adult population in Korea has rapidly decreased over time from 45.8 µg/L (1999) to 19.45 µg/L (2012-2014); however, it remains higher than that of the United States, Germany, and Canada. The factors significantly related to lead concentration in South Korea were age, sex, smoking and alcohol drinking status, herbal medication usage by females, residential area, drinking water at home, and occupation. These factors could be used to improve occupational and environmental hygiene among the Korean population.

Modified carotid sinus massage using an ultrasonography for maximizing vagal tone: a crossover simulation study.

INTRODUCTION: The aim of this study was to ascertain if a modified carotid sinus massage (CSM) using ultrasonography is superior to the conventional CSM for vagal tone generation. METHODS: This was a prospective, crossover, clinical trial including 30 subjects with sinus rhythm. Participants were paired, and they performed 2 types of CSM to each other. To perform the conventional technique, pressure was exerted at the point where the maximal impulse of the carotid pulse was palpated. In the modified technique, participants localized the point of maximal diameter just above the bifurcation of the common carotid artery using ultrasonography and applied pressure to that point. Mean differences between premaneuver and postmaneuver R-R intervals and heart rates were compared. The distance from the midline of the neck (x distance) to the angle of the mandible (y distance) was measured, and the mean distance between the 2 techniques was compared. RESULTS: The baseline mean premaneuver R-R interval and heart rate did not differ significantly between the 2 techniques. The postmaneuver R-R interval and heart rate as well as the mean R-R interval and heart rate differences were significantly greater in the modified CSM. The mean location determined using the modified CSM was located 0.8 cm lateral and 0.8 cm superior to the mean location of the conventional CSM. CONCLUSION: The modified CSM using ultrasonography might be more useful than the conventional CSM in reverting episodes of paroxysmal supraventricular tachycardia and may be a suitable alternative for treating the same in the emergency department.

Chronic Obstructive Pulmonary Disease (COPD) and Vapors, Gases, Dusts, or Fumes (VGDF): A Meta-analysis.

To evaluate the association between the risk of chronic obstructive pulmonary disease (COPD) and exposure to vapors, gases, dusts, or fumes (VGDF), we conducted a meta-analysis of epidemiological studies. We searched for studies investigating the relationship between COPD and occupational exposure to VGDF in the adult population. The bibliographic search was conducted in databases (PubMed and Google Scholar). Eleven studies that met predetermined inclusion criteria were included in the meta-analysis. We calculated the pooled odds ratio (OR) with its 95% confidence interval (CI) of COPD for exposure to VGDF using a random-effects model. The presence of publication bias was explored. There was moderate heterogeneity among the included studies (I(2) = 54.3%). In a random-effects model meta-analysis, the pooled OR for exposure to VGDF was 1.43 for COPD (95% CI: 1.19-1.73) compared with no exposure to VGDF. Publication bias was not observed in this study. Our study suggests that exposure to VGDF is associated with a higher risk of COPD. Further prospective cohort studies are needed to confirm this association.

Association of mixed polycyclic aromatic hydrocarbons exposure with oxidative stress in Korean adults.

Polycyclic aromatic hydrocarbons (PAHs) are widespread pollutants associated with several adverse health effects and PAH-induced oxidative stress has been proposed as a potential mechanism. This study evaluated the associations of single and multiple PAHs exposure with oxidative stress within the Korean adult population, using serum gamma glutamyltransferase (GGT) as an oxidative stress marker. Data from the Second Korean National Environmental Health Survey (2012-2014) were analyzed. For analysis, 5225 individuals were included. PAH exposure was assessed with four urinary PAH metabolites: 1-hydroxyphenanthrene, 1-hydroxypyrene, 2-hydroxyfluorene, and 2-naphthol. After adjusting for age, sex, body mass index, drinking, passive smoking, and current smoking (model 1), as well as the presence of diabetes and hepatobiliary diseases (model 2), complex samples general linear model regression analyses for each metabolite revealed a significant positive association between Ln(1-hydroxyphenanthrene) and Ln(GGT) (model 1: ß = 0.040, p < 0.01 and model 2: ß = 0.044, p < 0.05). For the complete dataset (n = 4378), a significant positive association was observed between mixture of four urinary PAH metabolites and serum GGT in both the quantile g-computation and the Bayesian kernel machine regression analysis. Our study provides evidence for the association between mixed PAH exposure and oxidative stress.

Amino acid substitutions in naphthalene dioxygenase from Pseudomonas sp. strain NCIB 9816-4 result in regio- and stereo-specific hydroxylation of flavanone and isoflavanone.

Wild-type naphthalene dioxygenase (NDO) from Pseudomonas sp. strain NCIB 9816-4 transforms relatively planar flavone and isoflavone to cis-dihydrodiols. However, this enzyme cannot catalyze the transformation of flavanone and isoflavanone in which a phenyl group bonds to the stereogenic C2 or C3 of the C-ring. Protein modeling suggested that Phe224 in the substrate binding site of NDO may play a key role in substrate specificity toward flavanone and isoflavanone. Site-directed mutants of NDO with substitution of Phe224 with Tyr biotransformed only the (S)-stereoisomers of flavanone and isoflavanone, producing an 8-OH group on the A-ring. In contrast, the Phe224Cys and Phe224Gln substitutions, which used (2S)-flavanone as a substrate, and Phe224Lys, which transformed (2S)-flavanone and (3S)-isoflavanone, each showed lower activity than the Phe224Tyr substitution. The remainder of the tested mutants had no activity with flavanone and isoflavanone. Protein docking studies of flavanone and isoflavanone to the modeled mutant enzyme structures revealed that an expanded substrate binding site, due to mutation at 224, as well as appropriate hydrophobic interaction with the residue at 224, are critical for successful binding of the substrates. Results of this study also suggested that in addition to the previously known Phe352, the Phe224 site of NDO appears to be important site for expanding the substrate range of NDO and bringing regiospecific and stereospecific hydroxylation reactions to C8 of the flavanone and isoflavanone A-rings.

Characterization of an isoeugenol monooxygenase (Iem) from Pseudomonas nitroreducens Jin1 that transforms isoeugenol to vanillin.

The isoeugenol monooxygenase (iem) gene from Pseudomonas nitroreducens Jin1, responsible for the conversion of isoeugenol to vanillin, was cloned and overexpressed in Escherichia coli. The purified Iem had a predicted molecular mass of 54 kDa. The V(max), K(M), and k(cat) values for it, using isoeugenol as substrate, were 4.2 µmol vanillin min(-1) mg(-1) of protein, 120 µM, and 3.8 s(-1), respectively. Maximum substrate turnover for Iem occurred at 30 °C and pH 9.0. An (18)Oxygen-labeling experiment revealed that oxidative cleavage of isoeugenol by Iem was catalyzed via a monooxygenation reaction, and that incorporation of the oxygen atom from O(2) into vanillin was preferable to incorporation from water. While the catalytic activity of Iem, as prepared, did not require the addition of any organic or metal cofactor, ICP-MS analysis showed 0.7 mol of iron per mol of Iem. Moreover site-directed mutagenesis of Iem of four conserved histidine residues individually, His(167), His(218), His(282), and His(471), which appear to be involved in ligand bonding with Fe(2+), resulted in a loss of activity. Enzyme activity was not appreciably influenced by preincubation of Iem with high concentrations of chelators, suggesting that iron is tightly bound. Iem has an iron-mediated mechanism that is widely spread among the three domains of life.

Dissection of SNARE-driven membrane fusion and neuroexocytosis by wedging small hydrophobic molecules into the SNARE zipper.

Neuronal SNARE proteins mediate neurotransmitter release at the synapse by facilitating the fusion of vesicles to the presynaptic plasma membrane. Cognate v-SNAREs and t-SNAREs from the vesicle and the plasma membrane, respectively, zip up and bring about the apposition of two membranes attached at the C-terminal ends. Here, we demonstrate that SNARE zippering can be modulated in the midways by wedging with small hydrophobic molecules. Myricetin, which intercalated into the hydrophobic inner core near the middle of the SNARE complex, stopped SNARE zippering in motion and accumulated the trans-complex, where the N-terminal region of v-SNARE VAMP2 is in the coiled coil with the frayed C-terminal region. Delphinidin and cyanidin inhibited N-terminal nucleation of SNARE zippering. Neuronal SNARE complex in PC12 cells showed the same pattern of vulnerability to small hydrophobic molecules. We propose that the half-zipped trans-SNARE complex is a crucial intermediate waiting for a calcium trigger that leads to fusion pore opening.

Evidence-based hyponatremia management in liver disease.

Hyponatremia is primarily a water balance disorder associated with high morbidity and mortality. The pathophysiological mechanisms behind hyponatremia are multifactorial, and diagnosing and treating this disorder remains challenging. In this review, the classification, pathogenesis, and step-by-step management approaches for hyponatremia in patients with liver disease are described based on recent evidence. We summarize the five sequential steps of the traditional diagnostic approach: 1) confirm true hypotonic hyponatremia, 2) assess the severity of hyponatremia symptoms, 3) measure urine osmolality, 4) classify hyponatremia based on the urine sodium concentration and extracellular fluid status, and 5) rule out any coexisting endocrine disorder and renal failure. Distinct treatment strategies for hyponatremia in liver disease should be applied according to the symptoms, duration, and etiology of disease. Symptomatic hyponatremia requires immediate correction with 3% saline. Asymptomatic chronic hyponatremia in liver disease is prevalent and treatment plans should be individualized based on diagnosis. Treatment options for correcting hyponatremia in advanced liver disease may include water restriction; hypokalemia correction; and administration of vasopressin antagonists, albumin, and 3% saline. Safety concerns for patients with liver disease include a higher risk of osmotic demyelination syndrome.

Occupational exposure to polycyclic aromatic hydrocarbons in Korean adults: evaluation of urinary 1-hydroxypyrene, 2-naphthol, 1-hydroxyphenanthrene, and 2-hydroxyfluorene using Second Korean National Environmental Health Survey data.

Background: Polycyclic aromatic hydrocarbons (PAHs) are occupational and environmental pollutants generated by the incomplete combustion of organic matter. Exposure to PAHs can occur in various occupations. In this study, we compared PAH exposure levels among occupations based on 4 urinary PAH metabolites in a Korean adult population. Methods: The evaluation of occupational exposure to PAHs was conducted using Second Korean National Environmental Health Survey data. The occupational groups were classified based on skill types. Four urinary PAH metabolites were used to evaluate PAH exposure: 1-hydroxypyrene (1-OHP), 2-naphthol (2-NAP), 1-hydroxyphenanthrene (1-OHPHE), and 2-hydroxyfluorene (2-OHFLU). The fraction exceeding the third quartile of urinary concentration for each PAH metabolite was assessed for each occupational group. Adjusted odds ratios (ORs) for exceeding the third quartile of urinary PAH metabolite concentration were calculated for each occupational group compared to the "business, administrative, clerical, financial, and insurance" group using multiple logistic regression analyses. Results: The "guard and security" (OR: 2.949; 95% confidence interval [CI]: 1.300-6.691), "driving and transportation" (OR: 2.487; 95% CI: 1.418-4.364), "construction and mining" (OR: 2.683; 95% CI: 1.547-4.655), and "agriculture, forestry, and fisheries" (OR: 1.973; 95% CI: 1.220-3.191) groups had significantly higher ORs for 1-OHP compared to the reference group. No group showed significantly higher ORs than the reference group for 2-NAP. The groups with significantly higher ORs for 1-OHPHE than the reference group were "cooking and food service" (OR: 2.073; 95% CI: 1.208-3.556), "driving and transportation" (OR: 1.724; 95% CI: 1.059-2.808), and "printing, wood, and craft manufacturing" (OR: 2.255; 95% CI: 1.022-4.974). The OR for 2-OHFLU was significantly higher in the "printing, wood, and craft manufacturing" group (OR: 3.109; 95% CI: 1.335-7.241) than in the reference group. Conclusions: The types and levels of PAH exposure differed among occupational groups in a Korean adult population.

Comparison of dominant and nondominant C3 deposition in primary glomerulonephritis.

BACKGROUND: Alternative complement pathway dysregulation plays a key role in glomerulonephritis (GN) and is associated with C3 deposition. Herein, we examined pathological and clinical differences between cases of primary GN with C3-dominant (C3D-GN) and nondominant (C3ND-GN) deposition. METHODS: We extracted primary GN data from the Korean GlomeruloNEphritis sTudy (KoGNET). C3D-GN was defined as C3 staining two grades greater than C1q, C4, and immunoglobulin via immunofluorescence analysis. To overcome a large difference in the number of patients between the C3D-GN and C3ND-GN groups (31 vs. 9,689), permutation testing was used for analysis. RESULTS: The C3D-GN group exhibited higher serum creatinine (p ≤ 0.001), a greater prevalence of estimated glomerular filtration rate of <60 mL/min/1.72 m2 (p ≤ 0.001), higher (but not significantly so) C-reactive protein level, and lower serum C3 level (p ≤ 0.001). Serum albumin, urine protein/creatinine ratio, number of patients who progressed to end-stage renal disease, and all-cause mortality were comparable between groups. Interstitial fibrosis and mesangial cellularity were greater in the C3D-GN group (p = 0.04 and p = 0.01, respectively) than in the C3ND-GN group. C3 deposition was dominant in the former group (p < 0.001), in parallel with increased subendothelial deposition (p ≤ 0.001). CONCLUSION: Greater progression of renal injury and higher mortality occurred in patients with C3D-GN than with C3ND-GN, along with pathologic differences in interstitial and mesangial changes.

Isolation of a gene responsible for the oxidation of trans-anethole to para-anisaldehyde by Pseudomonas putida JYR-1 and its expression in Escherichia coli.

A plasmid, pTA163, in Escherichia coli contained an approximately 34-kb gene fragment from Pseudomonas putida JYR-1 that included the genes responsible for the metabolism of trans-anethole to protocatechuic acid. Three Tn5-disrupted open reading frame 10 (ORF 10) mutants of plasmid pTA163 lost their abilities to catalyze trans-anethole. Heterologously expressed ORF 10 (1,047 nucleotides [nt]) under a T7 promoter in E. coli catalyzed oxidative cleavage of a propenyl group of trans-anethole to an aldehyde group, resulting in the production of para-anisaldehyde, and this gene was designated tao (trans-anethole oxygenase). The deduced amino acid sequence of TAO had the highest identity (34%) to a hypothetical protein of Agrobacterium vitis S4 and likely contained a flavin-binding site. Preferred incorporation of an oxygen molecule from water into p-anisaldehyde using (18)O-labeling experiments indicated stereo preference of TAO for hydrolysis of the epoxide group. Interestingly, unlike the narrow substrate range of isoeugenol monooxygenase from Pseudomonas putida IE27 and Pseudomonas nitroreducens Jin1, TAO from P. putida JYR-1 catalyzed isoeugenol, O-methyl isoeugenol, and isosafrole, all of which contain the 2-propenyl functional group on the aromatic ring structure. Addition of NAD(P)H to the ultrafiltered cell extracts of E. coli (pTA163) increased the activity of TAO. Due to the relaxed substrate range of TAO, it may be utilized for the production of various fragrance compounds from plant phenylpropanoids in the future.

One-step sequence- and ligation-independent cloning as a rapid and versatile cloning method for functional genomics studies.

We developed one-step sequence- and ligation-independent cloning (SLIC) as a simple, cost-effective, time-saving, and versatile cloning method. Highly efficient and directional cloning can be achieved by direct bacterial transformation 2.5 min after mixing any linearized vector, an insert(s) prepared by PCR, and T4 DNA polymerase in a tube at room temperature.

Transcriptional control of the isoeugenol monooxygenase of Pseudomonas nitroreducens Jin1 in Escherichia coli.

Vanillin is one of the most valuable compounds in the flavoring and fragrance industries, and many attempts to produce natural vanillin have been made in recent years. Isoeugenol monooxygenase (Iem) converts the phenylpropanoid compound isoeugenol to vanillin. In Pseudomonas nitroreducens Jin1, the positive regulatory protein IemR is divergently expressed from Iem, and the promoter region is located between the genes. In this study, we investigated the transcriptional regulation of iem in Escherichia coli. We focused on inducers and regulatory protein IemR. Transcription of iem was found to be dependent on the amounts of isoeugenol and IemR. Isoeugenol was found to be the best inducer of iem, followed by trans-anethole, which induced iem to 58% of the transcription level observed for isoeugenol. Overproduction of IemR in E. coli significantly increased the transcription of iem, up to 96-fold, even in the absence of isoeugenol, as compared to basally expressed IemR. Results of this study indicate that the transcription of iem iss dependent on the type of inducers and on IemR. They should contribute to the development of bioengineering strategies for increased production of vanillin through high-level expression of the isoeugenol monooxygenase gene in microorganisms.