Novel antiviral drug discovery strategies to tackle drug-resistant mutants of influenza virus strains

INTRODUCTION

The emergence of drug-resistant influenza virus strains highlights the need for new antiviral therapeutics to combat future pandemic outbreaks as well as continuing seasonal cycles of influenza. Areas covered: This review summarizes the mechanisms of current FDA-approved anti-influenza drugs and patterns of resistance to those drugs. It also discusses potential novel targets for broad-spectrum antiviral drugs and recent progress in novel drug design to overcome drug resistance in influenza. Expert opinion: Using the available structural information about drug-binding pockets, research is currently underway to identify molecular interactions that can be exploited to generate new antiviral drugs. Despite continued efforts, antivirals targeting viral surface proteins like HA, NA, and M2, are all susceptible to developing resistance. Structural information on the internal viral polymerase complex (PB1, PB2, and PA) provides a new avenue for influenza drug discovery. Host factors, either at the initial step of viral infection or at the later step of nuclear trafficking of viral RNP complex, are being actively pursued to generate novel drugs with new modes of action, without resulting in drug resistance.

Ferret animal model of severe fever with thrombocytopenia syndrome phlebovirus for human lethal infection and pathogenesis

Severe fever with thrombocytopenia syndrome phlebovirus (SFTSV), listed in the most dangerous pathogens by the World Health Organization, has 12-30% fatality rates with a characteristic thrombocytopenia syndrome. With a majority of clinically diagnosed SFTSV patients older than ~50 years of age, age is a critical risk factor for SFTSV morbidity and mortality. Here, we report an age-dependent ferret model of SFTSV infection and pathogenesis that fully recapitulates the clinical manifestations of human infections. Whereas young adult ferrets (≤2 years of age) did not show any clinical symptoms and mortality, SFTSV-infected aged ferrets (≥4 years of age) demonstrated severe thrombocytopenia, reduced white blood cell counts and high fever with 93% mortality rate. Moreover, a significantly higher viral load was observed in aged ferrets. Transcriptome analysis of SFTSV-infected young ferrets revealed strong interferon-mediated anti-viral signalling, whereas inflammatory immune responses were markedly upregulated and persisted in aged ferrets. Thus, this immunocompetent age-dependent ferret model should be useful for anti-SFTSV therapy and vaccine development.

Discrimination of the geographic origin of pork using multi-isotopes and statistical analysis

RATIONALE

While global pork production has grown exponentially in recent decades to 109 Mt in 2010, methods aimed at verifying the geographic origin of pork products have yet to be thoroughly investigated. Here, we analyzed pork samples available in South Korea in order to discriminate their geographic origin.

METHODS

A total of the 37 pork samples originated from South Korea and other countries (Denmark, Germany, France, Spain, Canada and Mexico) were collected in order to classify their geographic origins using multi-isotope ratios, such as δ¹⁸ O, δ² H, δ¹³ C, δ¹⁵ N values measured by IRMS, ⁸⁷ Sr/⁸⁶ Sr ratios measured by MC-ICP-MS, and multivariate statistical approaches.

RESULTS

There is a wide range of ⁸⁷ Sr/⁸⁶ Sr ratios in the pork samples, varying from 0.70779 to 0.71245, due to the lithology where the pork was raised. Canadian samples displayed the lowest δ¹⁸ O and δ² H values mainly due to the latitude effect. Furthermore, the δ¹³ C values of European and Canadian samples were lower than those of Korean and Mexican samples, depending on whether the feed was composed of either C₃ or C₄ plants. The δ¹⁵ N values of the European and Canadian samples were much higher than those of the other samples, possibly resulting from the δ¹⁵ N values of the feed.

CONCLUSIONS

While differences in pork samples were observed that depended on geographic origin, this study suggests that more detailed investigations are needed to validate whether a combination of multi-isotope and multivariate statistical approaches is a valid method for determining the geographic origin of pork.

Water quality impacts of irrigation return flow on stream and groundwater in an intensive agricultural watershed

Irrigation return flow can include contaminants derived from agricultural practices, and then deteriorate the quality of surface and subsurface water within the watershed. Thus, it is important to estimate the effect of irrigation return flow on water chemistry/quality. To do that water samples were collected between November 2004 and December 2005 from stream and groundwater in a small watershed that contains extensive rice paddy fields. The water isotopic compositions represented seasonal variation, particularly in downstream of main channel and the tributary. In April and May, water samples in the downstream and tributary could not be explained by three-component (soil water, groundwater and rainfall) hydrograph separation models (THSM). These results indicated that the stream water was affected by high evaporation and that another water body (e.g. quick return flow) impacted on THSM. Plot of Cl/NO₃ and NO₃/HCO₃ showed that the water chemistry of all water samples was mainly regulated by soil water and groundwater. In addition, the water chemistry was related to water derived from rice paddy fields (WR) and manure. Manure impacted the water chemistry in tributary, one of the shallow groundwaters and the deep groundwaters, whereas that water in downstream was affected by WR. On a plot of δ¹⁵N_NO3 and δ¹⁸O_NO3 values, many samples were in a cluster indicative of manure and on a denitrification line. These imply that irrigation return flow characterized by denitrification processes was involved in determining the water chemistry. We suggest that chemical and multi-isotopes approach combined with the THSM is useful to elucidate the sources and processes controlling water chemistry in stream associated with rice paddy fields.

Morphological Analysis of Tibiofibular Disruption Using CT images in Ankle Fractures with Unstable Syndesmotic Injury

Category:

Trauma

Introduction/Purpose:

We aimed to investigate the diagnostic value of CT scan and the morphologic pattern of distal tibiofibular disruption associated with fracture-type or concomitant avulsion fractures in cases of ankle fracture with unstable syndesmosis requiring surgical fixation.

Methods:

104 cases images(preoperative plane radiographs and CT axial images) of ankle fractures needed syndesmotic fixation due to unstable syndesmosis on intraoperative stress test were retrospectively reviewed. We classified ankle fractures by Lauge-Hansen classification and AO-OTA classification. Also, associated tibiofibular avulsion fractures including anterior distal tibiofibular avulsion fractures and posterior malleolar fractures were identified. Classification of posterior malleolar fractures based on Bartonícek-Rammelt classification was conducted. We grouped morphologic patterns of distal tibiofibular disruption which is 10 mm proximal to the plafond on CT axial images. We divided them into no diastasis, symmetric diastasis, anterior open, and posterior open according to the diastasis pattern, and no translation, anterior translation, and posterior translation depending on sagittal translation. Chi-square test/Fisher’s exact test and adjusted residual analysis were used for statistical analysis.

Results:

On LH classification, SER in 78(75%), PER in 18(17.3%), and PA in 8(7.7%). AITFL avulsions were in 37(35.6%) and PM fractures in 58(55.8%). Diastasis patterns were recorded in 30(28.8%) of no diastasis, 41(39.4%) of symmetric diastasis, 3(2.9%) of anterior open, and 30(28.8%) of posterior open. Depending on sagittal translation, 53(51.0%) of no translation, 44(42.3%) of anterior translation, and 7(6.7%) of posterior translation. Neither diastasis nor sagittal translation was revealed by CT in 17.3% of all. Syndesmotic morphologic pattern was various in SER [no diastasis (35.9%, AR=2.7), posterior open (35.9%, AR=2.7), and anterior translation (48.7%, AR=2.3)] whereas PER had relatively consistent pattern (symmetric diastasis in 88.9%, AR=4.7). Tibiofibular avulsion fractures such as Charput and PM fracture did not create distinct feature of widening.

Conclusion:

In terms of syndesmotic disruption pattern by CT images, PER fractures tend to show simple symmetric diastasis pattern, but SER fractures have a variety of patterns including normal appearance. Even if associated avulsion fracture do not make certain diastasis feature on static CT images, we still have to be careful not to overlook the syndesmotic instability. Diagnostic value of static imaging such as CT may not be higher than expected if not accompanied with intraoperative dynamic stress test.

Radiological outcome from Tight-RopeTM fixation for acute syndesmotic injury

Category:

Trauma

Introduction/Purpose:

The reduction and maintenance of tibiofibular joint is essential in the treatment of syndesmotic ankle injury. Tight-RopeTM (Arthrex, Naples, FL, USA) has been used recently but suspected in terms of tightening and sustaining power in spite of biomechanical results. We aimed to assess fixation-tightness and delayed syndesmotic widening after rehabilitation in syndesmotic injuries treated with Tight-RopeTM comparing with conventional screws.

Methods:

62 consecutive patients with acute syndesmotic injury were retrospectively reviewed. They were divided into 28 cases of Tight-RopeTM(TR) group and 34 cases of conventional screw fixation(Screw) group. We divided them into subgroups along the fixation methods such as 2 screws, 1 screw, TR only, and TR combined with screw. We analyzed syndesmotic widening by percentage. We measured tibiofibular clear space(TFCS) and tibiofibular overlap(TFOL). Tibiofibular clear space ratio and tibiofibular overlap ratio is measured as a ratio of tibiofibular clear space and tibiofibular overlap to the width of talar dome at preoperative, immediate postoperative, 3 months, and last (one year) visit time points and measured as a percentage of each measured value on the injured side to that on the contralateral side at the respective time points. The independent t-test and paired t-test were used for statistical analysis.

Results:

Mean TFCS ratio at each time point was 145.7±43.8%, 80.6±29.3%, 95.2±32.5%, and 96.3±31.1% in TR group and 126.2±42.6%, 73.9±22.6%, 104.8±59.2%, 106.4±35.0% in screw group. There were no statistical differences between groups in all 4 time points, no meaningful difference between subgroups. TFCS widening at 3 months in TR was less than screw group but no statistical significance. The TFCS was significantly tightened postoperatively then widened at 3 months and no meaningful change until last visit on both group. Mean TFOL ratio at each point was 51.84±43.6%, 119.2±36.7%, 110.7±44.5%, 96.8±27.7% in TR and 65.7±34.5%, 110.8±36.6%, 114.2±45.6%, 102.4±37.8% in screw group. There was no statistical difference between groups and subgroups. The overlap was increased postoperatively and no change between every sequential time points until last visit.

Conclusion:

The Tight-RopeTM fixation has a similar tightening and sustaining power compared to conventional screws and it was determined that the sustaining capacity did not decreased with time. Tight-RopeTM fixation can be effective treatment because it enables effective fixation, early weight-bearing and rehabilitation after surgery, and maintaining device for longer time in severe injury.

Surgical Treatment With Closing-Wedge Distal Femoral Osteotomy for Recurrent Patellar Dislocation With Genu Valgum

BACKGROUND

Closing-wedge distal femoral osteotomy (CWDFO)-combined with medial reefing and lateral release, if necessary- has been used to treat recurrent patellar dislocation (RPD) with genu valgum.

PURPOSE

To evaluate the clinical and radiologic outcomes of surgical treatment with CWDFO for treatment of RPD with genu valgum.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Fourteen consecutive patients (23 knees) with RPD and genu valgum were treated with CWDFO. Patients with a minimum 2-year follow-up period were eligible for this study. Patients with prior failed surgery were also eligible. Radiographic evaluation was performed with mechanical femorotibial and lateral distal femoral angle. The radiographic parameters presenting patellar positions and pathologic abnormalities associated with RPD were evaluated. Chondral lesion changes in second-look arthroscopic examination were examined, and clinical outcomes (eg, occurrence of redislocation, range of motion, and clinical scores) were assessed pre- and postoperatively at a minimum of 2 years.

RESULTS

At a mean follow-up of 30.7 months (range, 25-62 months), the mean mechanical femorotibial and mechanical lateral distal femoral angles changed significantly from valgus 5° (range, 2°-11°) to varus 3° (2°-11°; P < .001) and from 83° (range, 78°-86°) to 89° (84°-92°; P < .001), respectively. The mean patellar congruence angle improved from 40° lateral (range, 20°-53° lateral) to 4° medial (23° medial to 21° lateral; P < .001), as did the lateral patellofemoral angle from 26° (range, 8°-62°) to 9° (0°-15°; P < .001). Computed tomography scans showed that the mean distance of patellar lateral shift decreased from 13.5 mm (range, 4-22 mm) to 2.0 mm (-4 to 5 mm; P < .001). The mean tibial tubercle to trochlear groove distance significantly decreased from 20.4 to 13.5 mm ( P < .001), while the Caton-Deschamps ratio did not change significantly after surgery ( P = .984). Chondral lesions of the patella and trochlear groove significantly improved or were maintained. None of the patients experienced subluxation or redislocation after surgery. Patellar instability symptoms also improved, as validated by radiographic and other clinical outcomes.

CONCLUSION

CWDFO combined with medial reefing and lateral release successfully treated RPD with genu valgum for a minimum follow-up of 2 years, with improved patellar alignment and stability.

TRIM56-mediated monoubiquitination of cGAS for cytosolic DNA sensing

Intracellular nucleic acid sensors often undergo sophisticated modifications that are critical for the regulation of antimicrobial responses. Upon recognition of DNA, the cytosolic sensor cyclic GMP-AMP (cGAMP) synthase (cGAS) produces the second messenger cGAMP, which subsequently initiates downstream signaling to induce interferon-αβ (IFNαβ) production. Here we report that TRIM56 E3 ligase-induced monoubiquitination of cGAS is important for cytosolic DNA sensing and IFNαβ production to induce anti-DNA viral immunity. TRIM56 induces the Lys335 monoubiquitination of cGAS, resulting in a marked increase of its dimerization, DNA-binding activity, and cGAMP production. Consequently, TRIM56-deficient cells are defective in cGAS-mediated IFNαβ production upon herpes simplex virus-1 (HSV-1) infection. Furthermore, TRIM56-deficient mice show impaired IFNαβ production and high susceptibility to lethal HSV-1 infection but not to influenza A virus infection. This adds TRIM56 as a crucial component of the cytosolic DNA sensing pathway that induces anti-DNA viral innate immunity.

The protein cGAS responds to the presence of cytosolic DNA by producing the second messenger cGAMP, which triggers antiviral interferon responses. Here, Seo et al. show that ubiquitination by the E3 ligase TRIM56 enhances cGAS activity and is important for the immune response against DNA viruses.

Nitrogen, Sulfur, and Oxygen Isotope Ratios of Animal- and Plant-Based Organic Fertilizers Used in South Korea

Organic fertilizers are increasingly used in agriculture in Asia and elsewhere. Tracer techniques are desirable to distinguish the fate of nutrients added to agroecosystems with organic fertilizers from those contained in synthetic fertilizers. Therefore, we determined the nitrogen, sulfur, and oxygen isotope ratios of nitrogen- and sulfur-bearing compounds in animal- and plant-based organic fertilizers (ABOF and PBOF, respectively) used in South Korea to evaluate whether they are isotopically distinct. The δN values of total and organic nitrogen for ABOF ranged from +7 to +19‰ and were higher than those of PBOF (generally <+6‰). This suggests that ABOFs have distinct δN values suitable for tracing these fertilizer compounds in the plant-soil-water system, whereas PBOFs have similar δN values to synthetic fertilizers. However, δO values for nitrate (δO) from organic fertilizer samples (<+17.0‰) were consistently lower than those of synthetic nitrate-containing fertilizers. The δS values of total sulfur, organic sulfur compounds (e.g., carbon-bonded sulfur and hydriodic acid-reducible sulfur), and sulfate for ABOFs yielded wide and overlapping ranges of +0.3 to +6.3, +0.9 to +7.2, and -2.6 to +14.2‰, whereas those for PBOFs varied from -3.4 to +7.7, +1.4 to +9.4, and -4.1 to +12.5‰, respectively, making it challenging to distinguish the fate of sulfur compounds from ABOF and PBOF in the environment using sulfur isotopes. We conclude that the δN values of ABOFs and the O values of organic fertilizers are distinct from those of synthetic fertilizers and are a promising tool for tracing the fate of nutrients added by organic fertilizers to agroecosystems.

Anthropogenic rare earth elements and their spatial distributions in the Han River, South Korea

Rare earth elements (REE) consist of lanthanides (from La to Lu), together with yttrium and scandium, in which anthropogenic REE, such as gadolinium (Gd), lanthanum (La), and samarium (Sm), has emerged as micro-contaminants in natural waters in highly developed countries. Here, we collected water samples in the Han River (HR) and its tributaries flowing through Seoul Capital Area, the world's second largest metropolitan area in order to examine how and to what extent anthropogenic REE anomalies may occur. Water samples show higher light REE concentrations than heavy REE concentrations, while wastewater treatment plant (WWTP) samples display much higher heavy REE concentrations due to high Gd concentration. The PAAS-normalized REE patterns indicate that WWTP samples display the pronounced positive Gd anomalies, in which anthropogenic Gd from magnetic resonance imaging (MRI) diagnostic system occurs as a form of Gd complexation with either Cl^- or SO₄^2-. Due to the WWTP, both the HR and tributaries show also positive Gd anomalies and the anthropogenic Gd concentrations increase as a function of the distance from the Paldang dam. This result indicates a positive correlation between populaton, number of MRI instruments, and positive Gd anomaly. Similarly, positive La and Sm anomalies exist in the HR, indicating that the HR is also affected by their point sources. Based on the discharge rate and anthropogenic REE concentrations, their fluxes are estimated to be 952 ± 319 kg/yr, suggesting that this amount of fluxes could disturb REE distribution in the Yellow Sea, and pose harmful effects on aquatic ecosystems.

Discrimination of side-window glass of Korean autos by laser ablation inductively coupled plasma mass spectrometry

RATIONALE

Fragments of glass from cars are often found at crime scenes and can be crucial evidence for solving the crime. The glass fragments are important as trace evidence at crime scenes related to car accidents and burgled homes. By identifying the origin of glass fragments, it is possible to infer the identity of a suspect. Our results represent a promising approach to a thorough forensic investigation of car glass.

METHODS

Thirty-five samples from the side windows of cars produced and used in South Korea were collected from the official agencies of five car manufacturers and from two glassmakers. In addition, 120 samples from side mirrors were collected from the same suppliers as well as from small businesses. Their chemical compositions (including Pb isotopes) were analyzed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and linear discriminant analysis (LDA) was performed.

RESULTS

The percentages of major elements (Si, Ca, and Fe) in side-window glass varied within narrow ranges (30.0 ± 2.36%, 5.93 ± 0.52%, and 0.33 ± 0.05%, respectively), while the differences among Pb isotope ratios were not significant. In contrast, light rare earth elements (LREEs) were different from each glassmaker. From the LDA, the types of side-window glass were successfully discriminated according to car manufacturer, glassmaker, and even glass thickness. However, glass from side mirrors cannot be used for good forensic identifiers.

CONCLUSIONS

Discrimination techniques for side-window glass, although not for side mirrors, using chemical compositions combined with multivariate statistical analyses provide evidence for forensic investigations. Copyright © 2016 John Wiley & Sons, Ltd.

Identification of a Small Benzamide Inhibitor of Influenza Virus Using a Cell-Based Screening

BACKGROUND

The zoonotic transmission of highly pathogenic avian influenza viruses and the global pandemic of H1N1 influenza in 2009 signified the need for a wider coverage of therapeutic options for the control of influenza.

METHODS

An in-house compound library was screened using a cytopathic effect inhibition assay. Selected hits were then tested in vivo and used as a core skeleton for derivative synthesis.

RESULTS

The hit compound (BMD-2601505) was effective [50% effective concentration (EC50) of 60-70 μM] in reducing the death rate of cells infected with human influenza A and B viruses as well as avian influenza A virus. Furthermore, BMD-2601505 reduced the weight loss and increased the survival after lethal infection. The compound was further modified to enhance its antiviral potency. Results show that one derivative with bromobenzene moiety was most effective (EC50 of 22-37 μM) against the influenza viruses tested.

CONCLUSION

We identified a small benzamide compound exhibiting antiviral activity against influenza viruses. The results warrant further evaluation of antiviral activities against drug-resistant influenza isolates.

Osteonecrosis of Femoral Head Treated with Extracorporeal Shock Wave Therapy: Analysis of Short-term Clinical Outcomes of Treatment with Radiologic Staging

Purpose

To evaluate clinical results of extracorporeal shock wave therapy (ESWT) with radiographic staging on patients with avascular necrosis of femoral head (AVNFH).

Materials and Methods

We evaluated 24 patients diagnosed with AVNFH (32 hip joints) who were treated with ESWT from 1993 to 2012. Average follow-up period was 27 months, and the average age of patients was 47.8 years. The Association Research Circulation Osseous (ARCO) system was used to grade radiographic stage prior to treatment. For this study patients were divided into two groups based on their ARCO stage, group 1 (ARCO stages I and II) and group 2 (ARCO stage III). Comparative analyses were done between the two groups using the visual analogue scale (VAS) score and the Harris hip score (HHS) at pre-treatment and 3, 6, 12, and 24 months after treatment. Failure was defined when radiographic stage progressed or arthroplasty surgery was needed due to clinical exacerbation.

Results

Both groups showed clinical improvements with VAS scoring at final follow-up (group 1: median 7 to 1.5, P<0.001; group 2: mean 7 to 4, P=0.056). Using HHS, group 1 showed a significant improvement (from 65.5 to 95 [P<0.001]), while no significance was observed for group 2 (P=0.280). At final follow-up, 3 hips from group 1 and one hip from group 2 showed radiographic improvement; however, two patients underwent total hip arthroplasty due to persistent pain and dysfunction.

Conclusion

ESWT can be considered as an interventional option before surgical treatment in patients with not only early stage AVNFH but also with mid stage.

Natural and anthropogenic sources and processes affecting water chemistry in two South Korean streams

Acid mine drainage (AMD) in a watershed provides potential sources of pollutants for surface and subsurface waters that can deteriorate water quality. Between March and early August 2011, water samples were collected from two streams in South Korea, one dominantly draining a watershed with carbonate bedrock affected by coal mines and another draining a watershed with silicate bedrock and a relatively undisturbed catchment area. The objective of the study was to identify the sources and processes controlling water chemistry, which was dependent on bedrock and land use. In the Odae stream (OS), the stream in the silicate-dominated catchment, Ca, Na, and HCO3 were the dominant ions and total dissolved solids (TDS) was low (26.1-165 mg/L). In the Jijang stream (JS), in the carbonate-dominated watershed, TDS (224-434 mg/L) and ion concentrations were typically higher, and Ca and SO4 were the dominant ions due to carbonate weathering and oxidation of pyrite exposed at coal mines. Dual isotopic compositions of sulfate (δ(34)SSO4 and δ(18)OSO4) verified that the SO4 in JS is derived mainly from sulfide mineral oxidation in coal mines. Cl in JS was highest upstream and decreased progressively downstream, which implies that pollutants from recreational facilities in the uppermost part of the catchment are the major source governing Cl concentrations within the discharge basin. Dual isotopic compositions of nitrate (δ(15)NNO3 and δ(18)ONO3) indicated that NO3 in JS is attributable to nitrification of soil organic matter but that NO3 in OS is derived mostly from manure. Additionally, the contributions of potential anthropogenic sources to the two streams were estimated in more detail by using a plot of δ(34)SSO4 and δ(15)NNO3. This study suggests that the dual isotope approach for sulfate and nitrate is an excellent additional tool for elucidating the sources and processes controlling the water chemistry of streams draining watersheds having different lithologies and land-use patterns.

The necessity of bone densitometry for patients taking selective serotonin reuptake inhibitors

BACKGROUND

To analyze the necessity of bone densitometry for patients long-term taking selective serotonin reuptake inhibitors (SSRI) over a long period of time, which is one of the risk factors of osteoporosis.

METHODS

We selected patients from 5 veterans hospitals who took SSRI for more than 2 months while taking bone densitometry on a regular basis.

RESULTS

Of the 85 patients from a total of 5 veterans hospitals taking SSRI for more than two months, only 34 patients were under diagnosis and treatment measures of osteoporosis through checking each person's bone mineral density.

CONCLUSIONS

It is necessary for patients taking SSRI to check bone density on a regular basis.

Increased B-type natriuretic peptide during liver transplantation: relationship to invasively measured hemodynamic parameters

BACKGROUND

The role of B-type natriuretic peptide (BNP) concentration in predicting cardiac dysfunction has been extensively investigated in many clinical conditions. Little is known, however, about its relationships with hemodynamic parameters from right heart catheterization in patients undergoing liver transplant surgery.

METHODS

We retrospectively evaluated 525 patients who underwent liver transplantation. Hemodynamic variables from a Swan-Ganz catheter and BNP concentrations were measured 1 hour after induction of general anesthesia. Patients were stratified by quintiles of BNP concentrations. Univariate and multivariate logistic regression analysis were used to identify hemodynamic parameters associated with BNP ≥ 135 pg/mL, a cutoff point for the 5th quintile.

RESULTS

Univariate analysis showed that factors significantly associated with BNP ≥ 135 pg/mL included model for end-stage liver disease (MELD) score, diastolic blood pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure (PCWP), cardiac index, right ventricular end-diastolic volume index (RVEDVI), systemic vascular resistance index, pulmonary vascular resistance index (PVRI), and right ventricular stroke work index. Multivariate analysis revealed that MELD score (odds ratio [OR] = 1.059, P < .001), PCWP (OR = 1.116, P = .026), RVEDVI (OR = 1.010, P = .009), and PVRI (OR = 1.009, P = .002) were independent determinants of BNP ≥ 135 pg/mL.

CONCLUSIONS

Severity of liver disease, preload dependent hemodynamic parameters, and pulmonary vascular resistance were found to be significantly associated with increased BNP concentration, reinforcing the utility of BNP as a marker of cardiac strain and ventricular volume overload in liver failure patients undergoing liver transplant surgery.

Using stable isotope analysis to discriminate gasoline on the basis of its origin

RATIONALE

Leakage of gasoline and diesel from underground tanks has led to a severe environmental problem in many countries. Tracing the production origin of gasoline and diesel is required to enable the development of dispute resolution and appropriate remediation strategies for the oil-contaminated sites.

METHODS

We investigated the bulk and compound-specific isotopic compositions of gasoline produced by four oil companies in South Korea: S-Oil, SK, GS and Hyundai. The relative abundance of several compounds in gasoline was determined by the peak height of the major ion (m/z 44).

RESULTS

The δ(13)C(Bulk) and δD(Bulk) values of gasoline produced by S-Oil were significantly different from those of SK, GS and Hyundai. In particular, the compound-specific isotopic value (δ(13)C(CSIA)) of methyl tert-butyl ether (MTBE) in S-Oil gasoline was significantly lower than that of gasoline produced by other oil companies. The abundance of several compounds in gasoline, such as n-pentane, MTBE, n-hexane, toluene, ethylbenzene and o-xylene, differed widely among gasoline from different oil companies.

CONCLUSIONS

This study shows that gasoline can be forensically discriminated according to the oil company responsible for its manufacture using stable isotope analysis combined with multivariate statistical analysis.