Dynamic analysis of acute deterioration in chronic liver disease patients using modified quick sequential organ failure assessment.

BACKGROUND/AIMS: Quick sequential organ failure assessment (qSOFA) is believed to identify patients at risk of poor outcomes in those with suspected infection. We aimed to evaluate the ability of modified qSOFA (m-qSOFA) to identify high-risk patients among those with acutely deteriorated chronic liver disease (CLD), especially those with acute-onchronic liver failure (ACLF). METHODS: We used data from both the Korean Acute-on-Chronic Liver Failure (KACLiF) and the Asian Pacific Association for the Study of the Liver ACLF Research Consortium (AARC) cohorts. qSOFA was modified by replacing the Glasgow Coma Scale with hepatic encephalopathy, and an m-qSOFA ≥2 was considered high. RESULTS: Patients with high m-qSOFA had a significantly lower 1-month transplant-free survival (TFS) in both cohorts and higher organ failure development in KACLiF than those with low m-qSOFA (Ps<0.05). Subgroup analysis by ACLF showed that patients with high m-qSOFA had lower TFS than those with low m-qSOFA. m-qSOFA was an independent prognostic factor (hazard ratios, HR=2.604, 95% confidence interval, CI 1.353-5.013, P=0.004 in KACLiF and HR=1.904, 95% CI 1.484- 2.442, P<0.001 in AARC). The patients with low m-qSOFA at baseline but high m-qSOFA on day 7 had a significantly lower 1-month TFS than those with high m-qSOFA at baseline but low m-qSOFA on day 7 (52.6% vs. 89.4%, P<0.001 in KACLiF and 26.9% vs. 61.5%, P<0.001 in AARC). CONCLUSION: Baseline and dynamic changes in m-qSOFA may identify patients with a high risk of developing organ failure and short-term mortality among CLD patients with acute deterioration.

Safety and Efficacy Assessment of Red Ginseng Oil (RXGIN) in Men with Lower Urinary Tract Symptoms in a Randomized, Double-Blind, Placebo-Controlled Trial.

PURPOSE: The purpose of this study was to evaluate the efficacy and safety of red ginseng oil (RXGIN) in men with lower urinary tract symptoms. MATERIALS AND METHODS: Men aged between 40 and 75 years with a total International Prostate Symptom Score (IPSS) of 8 to 19 points were recruited from April 2020 to December 2020. Subjects were randomly assigned to either the RXGIN group or the control group in a 1:1 ratio and received either RXGIN or placebo daily for 12 weeks. For the primary outcome, changes in IPSS scores at 6 and 12 weeks from baseline were analyzed. The secondary outcomes were changes in International Index of Erectile Function (IIEF), maximum urinary flow rate, and post-void residual volume at weeks 6 and 12 compared to baseline. Urine analysis and blood tests were additionally performed for safety assessment. RESULTS: A total of 88 subjects (RXGIN group, 46; control group, 42) completed the study. The total IPSS and IPSS subscores (residual urine sensation, frequency, intermittency, urgency, weak stream, straining, nocturia, and quality of life) were significantly improved in the RXGIN group compared to the control group at weeks 6 and 12. Total IIEF and sexual desire were significantly improved in the RXGIN group at week 6 and week 12, respectively, but there were no significant changes in the level of serum testosterone or dihydrotestosterone. The serum prostate-specific antigen showed significant decrease at weeks 12. No serious adverse events leading to discontinuation of the study drug were observed in the RXGIN group. CONCLUSIONS: Red ginseng oil (RXGIN) appears to be safe and effective in improving lower urinary tract symptoms in men and may also improve some aspects of sexual function.

Assessment of deep learning-based auto-contouring on interobserver consistency in target volume and organs-at-risk delineation for breast cancer: Implications for RTQA program in a multi-institutional study.

PURPOSE: To quantify interobserver variation (IOV) in target volume and organs-at-risk (OAR) contouring across 31 institutions in breast cancer cases and to explore the clinical utility of deep learning (DL)-based auto-contouring in reducing potential IOV. METHODS AND MATERIALS: In phase 1, two breast cancer cases were randomly selected and distributed to multiple institutions for contouring six clinical target volumes (CTVs) and eight OAR. In Phase 2, auto-contour sets were generated using a previously published DL Breast segmentation model and were made available for all participants. The difference in IOV of submitted contours in phases 1 and 2 was investigated quantitatively using the Dice similarity coefficient (DSC) and Hausdorff distance (HD). The qualitative analysis involved using contour heat maps to visualize the extent and location of these variations and the required modification. RESULTS: Over 800 pairwise comparisons were analysed for each structure in each case. Quantitative phase 2 metrics showed significant improvement in the mean DSC (from 0.69 to 0.77) and HD (from 34.9 to 17.9 mm). Quantitative analysis showed increased interobserver agreement in phase 2, specifically for CTV structures (5-19 %), leading to fewer manual adjustments. Underlying IOV differences causes were reported using a questionnaire and hierarchical clustering analysis based on the volume of CTVs. CONCLUSION: DL-based auto-contours improved the contour agreement for OARs and CTVs significantly, both qualitatively and quantitatively, suggesting its potential role in minimizing radiation therapy protocol deviation.

Pulmonary Rehabilitation Is Associated With Decreased Exacerbation and Mortality in Patients With COPD: A Nationwide Korean Study.

BACKGROUND: Poor uptake to pulmonary rehabilitation (PR) is still challenging around the world. There have been few nationwide studies investigating whether PR impacts patient outcomes in COPD. We investigated the change of annual PR implementation rate, medical costs, and COPD outcomes including exacerbation rates and mortality between 2015 and 2019. RESEARCH QUESTION: Does PR implementation improve outcomes in patients with COPD in terms of direct cost, exacerbation, and mortality? STUDY DESIGN AND METHODS: Data of patients with COPD extracted from a large Korean Health Insurance Review and Assessment service database (2015-2019) were analyzed to determine the trends of annual PR implementation rate and direct medical costs of PR. Comparison of COPD exacerbation rates between pre-PR and post-PR, and the time to first exacerbation and mortality rate according to PR implementation, were also assessed. RESULTS: Among all patients with COPD in South Korea, only 1.43% received PR. However, the annual PR implementation rate gradually increased from 0.03% to 1.4% during 4 years, especially after health insurance coverage commencement. The direct medical cost was significantly higher in the PR group than the non-PR group, but the costs in these groups showed decreasing and increasing trends, respectively. Both the incidence rate and frequency of moderate-to-severe and severe exacerbations were lower during the post-PR period compared with the pre-PR period. The time to the first moderate-to-severe and severe exacerbations was longer in the PR group than the non-PR group. Finally, PR implementation was associated with a significant decrease in mortality. INTERPRETATION: We concluded that health insurance coverage increases PR implementation rates. Moreover, PR contributes toward improving outcomes including reducing exacerbation and mortality in patients with COPD. However, despite the well-established benefits of PR, its implementation rate remains suboptimal.

A Comparison of 2 Disease Burden Assessment Methods (3D Volume Versus the Number of Lesions) for Prognostication of Survival in Metastatic Melanoma: Implications for the Characterization of Oligometastatic Disease.

PURPOSE: Oligometastatic disease (OMD), generally defined by the presence of ≤5 metastatic lesions, represents an intermediate state between localized and widespread metastatic disease. This study aimed to question the conventional definition of OMD and assess the significance of the total volume and loci of metastases in characterizing OMD using an unselected metastatic melanoma cohort. METHODS AND MATERIALS: We identified 86 consecutive patients with metastatic melanoma who received pembrolizumab monotherapy from 2015 to 2020. We retrospectively contoured the gross tumor volumes of all metastatic lesions on baseline and follow-up imaging. The number, total volume, and loci information of metastases was collected. The primary endpoint was overall survival. A density histogram plot was used for tumor characteristic descriptions, and classification analysis using the decision tree and random forest methods was performed to determine the optimal combination of prognostic factors in the clinical setting. RESULTS: A total of 2728 gross tumor volumes were delineated. On baseline imaging, the median number and total volume of metastases was 7 (interquartile range, 3-17) and 28.4 cc (interquartile range, 8.4-88.78), respectively. The lymph node was the most common metastatic site (n = 46, 54%), followed by the lungs (n = 32, 37%), liver (n = 23, 27%), and bones (n = 21, 24%). Two-year overall survival rates of patients with 1 to 5, 6 to 10, 11 to 20, and >20 metastases were 58%, 47%, 31%, and 14%, respectively, and with ≤10, 11 to 30, 31 to 130, and >130 cc of metastatic volume were 64%, 43%, 33%, and 25%, respectively. K-adaptive partitioning revealed that the optimal cutoff was 20 and 37.9 cc. Decision tree and random forest analyses revealed that volume and loci (brain and liver metastases) were the most important factors (Harrell's C-index, 0.78). CONCLUSIONS: The OMD state could represent a continuous spectrum of disease burden instead of a binary phenomenon. We propose integrating the volumetric and spatial information of metastases into the characterization of OMD and the stratification tool of clinical trials in the metastatic setting, although external validation studies are needed.

Diagnostic Feasibility of Magnetic Resonance Elastography Radiomics Analysis for the Assessment of Hepatic Fibrosis in Patients With Nonalcoholic Fatty Liver Disease.

OBJECTIVE: The aim of the study was to investigate the diagnostic feasibility of radiomics analysis using magnetic resonance elastography (MRE) to assess hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: One hundred patients with suspected NAFLD were retrospectively enrolled. All patients underwent a liver parenchymal biopsy. Magnetic resonance elastography was performed using a 3.0-T scanner. After multislice segmentation of MRE images, 834 radiomic features were analyzed using a commercial program. Radiologic features, such as median and mean values of the regions of interest and variable clinical features, were analyzed. A random forest regressor was used to extract important radiomic, radiological, and clinical features. A random forest classifier model was trained to use these features to classify the fibrosis stage. The area under the receiver operating characteristic curve was evaluated using a classifier for fibrosis stage diagnosis. RESULTS: The pathological hepatic fibrosis stage was classified as low-grade fibrosis (stages F0-F1, n = 82) or clinically significant fibrosis (stages F2-F4, n = 18). Eight important features were extracted from radiomics analysis, with the 2 most important being wavelet-high high low gray level dependence matrix dependence nonuniformity-normalized and wavelet-high high low gray level dependence matrix dependence entropy. The median value of the multiple small regions of interest was identified as the most important radiologic feature. Platelet count has been identified as an important clinical feature. The area under the receiver operating characteristic curve of the classifier using radiomics was comparable with that of radiologic measures (0.97 ± 0.07 and 0.96 ± 0.06, respectively). CONCLUSIONS: Magnetic resonance elastography radiomics analysis provides diagnostic performance comparable with conventional MRE analysis for the assessment of clinically significant hepatic fibrosis in patients with NAFLD.

Quantitative assessment of increase in orbital volume after orbital floor fracture reconstruction using a bioabsorbable implant.

PURPOSE: To assess the postoperative changes in the orbital volume and the degree of enophthalmos after orbital floor fracture reconstruction using a bioabsorbable implant and to determine the predictors of postoperative orbital volume change. METHODS: Single-center, retrospective case series of 16 patients who underwent orbital floor fracture reconstruction using a bioabsorbable implant [poly(L-lactic acid)-poly(glycolic acid)/ß-tricalcium phosphate; Biobsorb ß®] were included. Three-dimensional volumetric calculations of orbit were determined using computed tomography scans and the degree of enophthalmos was assessed via Hertel exophthalmometry. Postoperative changes in the orbital volume and the degree of enophthalmos and their correlation were assessed. RESULTS: The mean volume of fractured orbits immediately after surgery was 22.26 ± 1.98 cm3, increasing to 23.67 ± 2.00 cm3 at 6-month follow-up (p < 0.001); the increased orbital volume was associated with postoperative deformation of the implant. The mean degree of enophthalmos was 0.09 ± 0.27 mm at 1-month follow-up, which increased to 0.66 ± 0.30 mm at 6-month follow-up (p = 0.001). Increase in orbital volume and enophthalmos progression showed a linear correlation (R = 0.682, p = 0.004). Patients with more herniated orbital tissue preoperatively showed increased postoperative orbital volume change (p = 0.015), whereas the size of the fracture area was not predictive of postoperative orbital volume change (p = 0.442). CONCLUSION: Increase in orbital volume by deformation of the bioabsorbable implant resulted in progressive enophthalmos during the postoperative follow-up period after orbital floor fracture reconstruction. Thus, careful selection of proper implants before surgery and close postoperative follow-up is needed for an optimal outcome.

Clinical Role of the Chronic Obstructive Pulmonary Disease Assessment Test in Prediction of the Response to Treatment for Exacerbations.

BACKGROUND: The chronic obstructive pulmonary disease (COPD) assessment test (CAT) is a validated, eight-item questionnaire used to quantify the health status of patients. The aim of this study was to evaluate the usefulness of the CAT questionnaire as a tool to assess the response to treatment in acute exacerbations of COPD in an outpatient setting. METHODS: A multicenter, phase 3 randomized controlled trial was conducted previously to examine the efficacy and safety of oral zabofloxacin for the treatment of COPD exacerbations. In the present post hoc analysis of the original study, patients with COPD exacerbation were categorized as responders or non-responders according to the respiratory symptoms persisting on day 10 (visit 3) of treatment. The CAT questionnaire was completed daily by patients at home from the initial visit to the second visit on day 5. Subsequently, the questionnaire was completed in the presence of a physician on days 10 (visit 3) and 36 (visit 4). Multivariate regression analysis was performed to determine the association between CAT scores and the therapeutic response. RESULTS: The CAT scores decreased more rapidly in responders compared to non-responders during the first 5 days (23.3-20.4 vs. 23.5-22). Among responders, patients with higher severity of illness also revealed higher CAT scores on the first day of an exacerbation (mild, 19.8; moderate, 21.4; severe, 23.8; very severe, 28.6). Multivariate analysis revealed that a change in the CAT score during the first 3 days influenced the therapeutic response. A significant decrease in scores in the domains of sputum production, chest tightness, and activities of daily living was seen among responders. CONCLUSION: Early improvement in CAT scores may be associated with a more favorable response to the treatment of COPD exacerbations. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01658020. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0000532.

Tumor Homing Reactive Oxygen Species Nanoparticle for Enhanced Cancer Therapy.

Multifunctional nanoparticles that carry chemotherapeutic agents can be innovative anticancer therapeutic options owing to their tumor-targeting ability and high drug-loading capacity. However, the nonspecific release of toxic DNA-intercalating anticancer drugs from the nanoparticles has significant side effects on healthy cells surrounding the tumors. Herein, we report a tumor homing reactive oxygen species nanoparticle (THoR-NP) platform that is highly effective and selective for ablating malignant tumors. Sodium nitroprusside (SNP) and diethyldithiocarbamate (DDC) were selected as an exogenous reactive oxygen species (ROS) generator and a superoxide dismutase 1 inhibitor, respectively. DDC-loaded THoR-NP, in combination with SNP treatment, eliminated multiple cancer cell lines effectively by the generation of peroxynitrite in the cells (>95% cell death), as compared to control drug treatments of the same concentration of DDC or SNP alone (0% cell death). Moreover, the magnetic core (ZnFe2O4) of the THoR-NP can specifically ablate tumor cells (breast cancer cells) via magnetic hyperthermia, in conjunction with DDC, even in the absence of any exogenous RS supplements. Finally, by incorporating iRGD peptide moieties in the THoR-NP, integrin-enriched cancer cells (malignant tumors, MDA-MB-231) were effectively and selectively killed, as opposed to nonmetastatic tumors (MCF-7), as confirmed in a mouse xenograft model. Hence, our strategy of using nanoparticles embedded with ROS-scavenger-inhibitor with an exogenous ROS supplement is highly selective and effective cancer therapy.

Assessment and prediction of acute kidney injury in patients with decompensated cirrhosis with serum cystatin C and urine N-acetyl-ß-D-glucosaminidase.

BACKGROUND AND AIM: For appropriate management of acute kidney injury (AKI) in cirrhotic patients, accurate differentiation of the types of AKI, prerenal azotemia (PRA), hepatorenal syndrome (HRS), and acute tubular necrosis (ATN) is very important. Urine N-acetyl-ß-D-glucosaminidase (NAG) has been proposed as a good tubular injury marker in many studies, but its efficacy in cirrhosis is unclear. This study was performed to evaluate the usefulness of urine NAG in patients with decompensated cirrhosis. METHODS: In 114 hospitalized patients with decompensated cirrhosis, we assessed serum creatinine, cystatin C, and urine NAG levels as markers for AKI differentiation and development and patient mortality. RESULTS: Thirty patients diagnosed with AKI at baseline had significantly higher serum creatinine and cystatin C levels, urine NAG levels, and Child-Pugh scores than those without AKI. Only urine NAG levels were significantly higher in patients with ATN than those with PRA or HRS (116.1 ± 46.8 U/g vs 39.4 ± 20.2 or 54.0 ± 19.2 U/g urinary creatinine, all P < 0.05). During a median follow up of 6.1 months, AKI developed in 17 of 84 patients: PRA in nine, HRS in six, and ATN in three. Higher serum cystatin C and urine NAG levels were independent predictors of AKI development in patients with decompensated cirrhosis. Survival was significantly associated with low serum cystatin C and urine NAG levels. CONCLUSION: Serum cystatin C and urine NAG levels are useful to differentiate types of AKI and are strong predictors for AKI development and mortality in patients with decompensated cirrhosis.

Protection against High-Fat-Diet-Induced Obesity in MDM2C305F Mice Due to Reduced p53 Activity and Enhanced Energy Expenditure.

The RPL11-MDM2 interaction constitutes a p53 signaling pathway activated by deregulated ribosomal biosynthesis in response to stress. Mice bearing an MDM2C305F mutation that disrupts RPL11-MDM2 binding were analyzed on a high-fat diet (HFD). The Mdm2C305F/C305F mice, although phenotypically indistinguishable from wild-type (WT) mice when fed normal chow, demonstrated decreased fat accumulation along with improved insulin sensitivity and glucose tolerance after prolonged HFD feeding. We found that HFD increases expression of c-MYC and RPL11 in both WT and Mdm2C305F/C305F mice; however, p53 was induced in WT but not in Mdm2C305F/C305F mice. Reduced p53 activity in HFD-fed Mdm2C305F/C305F mice resulted in higher levels of p53 downregulated targets GLUT4 and SIRT1, leading to increased biosynthesis of NAD+, and increased energy expenditure. Our study reveals a role for the RPL11-MDM2-p53 pathway in fat storage during nutrient excess and suggests that targeting this pathway may be a potential treatment for obesity.

Transaxillary robotic modified radical neck dissection: a 5-year assessment of operative and oncologic outcomes.

BACKGROUND: Robotic modified radical neck dissection (MRND) using a gasless transaxillary approach has been reported to be a safe and meticulous technique in patients with papillary thyroid carcinoma (PTC) and lateral neck node metastasis (N1b). Few studies, however, have attempted to assess the long-term oncologic outcomes of robotic MRND in these patients. This study aimed to compare perioperative and 5-year oncologic outcomes of robotic MRND with conventional open procedures in patients with N1b PTC. METHODS: Between September 2007 and February 2010, 193 patients with N1b PTC underwent total thyroidectomy and MRND by a single surgeon. Of these, 42 (21.8 %) underwent robotic procedures and 151 (78.2 %) underwent conventional open procedures. All patients received 3.7- to 5.5-GBq radioactive iodine (RAI) ablation, post-therapy whole-body scans (TxWBSs), and diagnostic WBS (DxWBSs) during follow-up. An exact 1:3 matching for age and stage was performed to minimize selection bias, and perioperative and 5-year oncologic outcomes were compared in the matched groups. RESULTS: The mean follow-up period was 66.0 months (range 60-90 months). Number of retrieved cervical lymph nodes (LNs) (p = .102) and postoperative ablation success rates (p = .864) were similar between the two groups. TSH-suppressed serum Tg concentrations after 5 years (0.7 ± 1.5 vs. 2.4 ± 14.1 ng/ml; p = .471) and recurrence rates in the robotic and open groups (1/41 [2.4 %] vs. 3/102 [2.9 %]; p = .864) were similar for the 5-year follow-up period. Four patients experienced recurrence: Three exhibited regional lymph node metastasis, and one showed bilateral lung metastases. CONCLUSION: The perioperative and 5-year oncologic outcomes were similar after robotic and conventional open MRND. Large, prospective randomized controlled trials with long-term follow-up data are needed to validate these results.

Combination of surgical subcision and intralesional corticosteroid injection as a cost-effective and minimally invasive treatment for postoperative adhesive thyroidectomy scars.

BACKGROUND: Postoperative adhesive symptoms (swallowing difficulty or pulling sensation during neck extension) are one of the major complications of thyroidectomy. Moreover, adhesive scars are often visible and cause cosmetic concerns. OBJECTIVE: To evaluate the efficacy and safety of combined treatment with surgical subcision and intralesional corticosteroid injection for postoperative adhesive thyroidectomy scars. METHODS: A retrospective analysis was performed of 16 Korean patients with postoperative adhesive thyroidectomy scars treated with three sessions of surgical subcision and intralesional corticosteroid injection. RESULTS: The Vancouver Scar Scale score decreased significantly after treatment (P < .001). Follow-up revealed that six of the 16 patients (37.5%) had clinical improvement of 51% to 75%, six (37.5%) had moderate clinical improvement of 26% to 50%, and three (18.8%) had improvement of 76% to 100%; one patient (6.3%) demonstrated minimal to no improvement. After three sessions of treatment, the mean clinical improvement grade was 2.68, which means moderate to marked improvement compared to before treatment. Post-treatment erythema was observed in most patients, and notable bruising after treatment observed in five patients resolved spontaneously within 7 days. CONCLUSION: Combined treatment with surgical subcision and intralesional corticosteroid injection is a cost-effective and minimally invasive treatment for postoperative adhesive thyroidectomy scars.

Collateral ventilation in a canine model with bronchial obstruction: assessment with xenon-enhanced dual-energy CT.

PURPOSE: To determine the feasibility of the use of xenon-enhanced dynamic dual-energy computed tomography (CT) for visualization and quantitative assessment of collateral ventilation in a canine model with bronchial obstruction. MATERIALS AND METHODS: This study was approved by the institutional animal care and use committee. One segmental bronchus was occluded in nine dogs (weight range, 20-25 kg). Dynamic dual-energy CT scanning was performed by using dual-source CT during the wash-in-washout study of xenon inhalation via mechanical ventilation. Imaging parameters were 14 x 1.2-mm collimation, 40 mAs (effective) at 140 kV and 170 mAs (effective) at 80 kV, pitch of 0.45, and 0.33-second rotation time. By using dual-energy software, CT images and xenon maps were reconstructed. CT attenuation values were measured in the airways proximal to obstruction (AW(PROX)) and airways distal to obstruction (AW(DIST)) and at the parenchyma with patent airways (P(PATE)) and parenchyma with obstructed airways (P(OBST)). CT attenuation values on dynamic xenon maps were plotted with exponential function; ventilation parameters, including velocity of ventilation (K value), magnitude of ventilation (A value), and time of arrival (TOA), were calculated on the basis of the Kety model. RESULTS: In all animals, delayed and weaker xenon enhancement was identified at the airway and parenchyma distal to obstruction. For the A value, in the wash-in study, the differences between AW(PROX) and AW(DIST) and between P(PATE) and P(OBST) were significant (71.80 and 57.64, P = .05; 51.86 and 37.52 HU, P = .02). The K value of P(OBST) was lower than that of P(PATE) in the wash-in study (0.006 and 0 .010, P = .06). Mean and standard deviation for TOA were observed in the following increasing order: AW(PROX) ([3.50 +/- 7.70] x 10(-6) sec), P(PATE) (4.58 +/- 2.83), AW(DIST) (9.20 +/- 6.87), and P(OBST) (21.00 +/- 13.44). CONCLUSION: Collateral ventilation in a canine model with bronchial obstruction can be quantitatively assessed by using xenon-enhanced dynamic dual-energy CT.

Exposure assessment of polybrominated diphenyl ethers (PBDE) in umbilical cord blood of Korean infants.

This study examined the levels of polybrominated diphenyl ethers (PBDE) in the umbilical cord blood of infants, and investigated the relationship between PBDE concentration and thyroid hormone levels. The concentration of PBDE were measured in the cord blood samples of 108 infants collected in Cheil Woman's Hospital, Seoul, Korea, in 2007. Of 108 pregnant woman reported, the average age was 31.9 +/- 3.54 yr (range 20-42 yr). The mean body weight of the infants was 3.15 +/- 0.57 kg (1.89-4.43 kg), and no birth defects were documented. The concentrations of the total PBDEs (7 congeners) found in the umbilical cord blood averaged 8.377 +/- 6.381 ng/g lipid, ranging from not determined (ND) to 29.407 ng/g lipid. Of the seven congeners detected, BDE-47 (4.571 +/- 2.903 ng/g lipid) accounted for the majority (38% of total PBDE) of total PBDE, followed in descending order by BDE-153 (3.080 +/- 2.231 ng/g lipid) and BDE-183 (2.933 +/- 2.386). There was no apparent correlation between the serum PBDE levels and thyroid hormone concentrations. Similarly, there was no apparent relationship between the infant thyroxine (T4) levels and four prevalent PBDE congener concentrations. Data suggest that the concentration of PBDE in umbilical cord blood of Korean infants is similar to or lower than concentrations reported from North America. In addition, PBDE readily crossed the blood placenta barrier. Therefore, further study on the relationship between the maternal and fetal blood concentrations of PBDE is recommended for a more comprehensive exposure assessment of PBDE in Koreans.

Comparative assessment of coal tars obtained from 10 former manufactured gas plant sites in the eastern United States.

A comparative analysis was performed on eleven coal tars obtained from former manufactured gas plant sites in the eastern United States. Bulk properties analyzed included percent ash, Karl Fisher water content, viscosity and average molecular weight. Chemical properties included monocyclic- and polycyclic-aromatic hydrocarbon (PAH) concentrations, alkylated aromatic concentrations, and concentrations of aliphatic and aromatic fractions. It was found that there was at least an order-of-magnitude variation in all properties measured between the eleven coal tars. Additionally, two coal tars obtained from the same manufactured gas plant site had very different properties, highlighting that there can be wide variations in coal tar properties from different samples obtained from the same site. Similarities were also observed between the coal tars. The relative chemical distributions were similar for all coal tars, and the coal tars predominantly consisted of PAHs, with naphthalene being the single-most prevalent compound. The C(9-22) aromatic fraction, an indicator of all PAHs up to a molecular weight of approximately 276 gmole(-1), showed a strong power-law relationship with the coal tar average molecular weight (MW (ct)). And the concentrations of individual PAHs decreased linearly as MW (ct) increased up to ca. 1000 gmole(-1), above which they remained low and variable. Implications of these properties and their variation with MW (ct) on groundwater quality are discussed. Ultimately, while these similarities do allow generalities to be made about coal tars, the wide range of coal tar bulk and chemical properties reported here highlights the complex nature of coal tars.