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1.
Nat Commun ; 14(1): 3704, 2023 Jun 22.
Article in English | MEDLINE | ID: mdl-37349307

ABSTRACT

At seasonal-to-interannual timescales, Atlantic hurricane activity is greatly modulated by El Niño-Southern Oscillation and the Atlantic Meridional Mode. However, those climate modes develop predominantly in boreal winter or spring and are weaker during the Atlantic hurricane season (June-November). The leading mode of tropical Atlantic sea surface temperature (SST) variability during the Atlantic hurricane season is Atlantic Niño/Niña, which is characterized by warm/cold SST anomalies in the eastern equatorial Atlantic. However, the linkage between Atlantic Niño/Niña and hurricane activity has not been examined. Here, we use observations to show that Atlantic Niño, by strengthening the Atlantic inter-tropical convergence zone rainband, enhances African easterly wave activity and low-level cyclonic vorticity across the deep tropical eastern North Atlantic. We show that such conditions increase the likelihood of powerful hurricanes developing in the deep tropics near the Cape Verde islands, elevating the risk of major hurricanes impacting the Caribbean islands and the U.S.


Subject(s)
Cyclonic Storms , Cabo Verde , Temperature , Seasons , El Nino-Southern Oscillation
2.
Nat Commun ; 13(1): 1915, 2022 Apr 08.
Article in English | MEDLINE | ID: mdl-35395824

ABSTRACT

Future changes in the seasonal evolution of the El Niño-Southern Oscillation (ENSO) during its onset and decay phases have received little attention by the research community. This work investigates the projected changes in the spatio-temporal evolution of El Niño events in the 21st Century (21 C), using a multi-model ensemble of coupled general circulation models subjected to anthropogenic forcing. Here we show that El Niño is projected to (1) grow at a faster rate, (2) persist longer over the eastern and far eastern Pacific, and (3) have stronger and distinct remote impacts via teleconnections. These changes are attributable to significant changes in the tropical Pacific mean state, dominant ENSO feedback processes, and an increase in stochastic westerly wind burst forcing in the western equatorial Pacific, and may lead to more significant and persistent global impacts of El Niño in the future.

3.
Financ Res Lett ; 45: 102660, 2022 Mar.
Article in English | MEDLINE | ID: mdl-35002551

ABSTRACT

The COVID-19 pandemic in Korea provides grounds for understanding the effect of corporate social responsibility (CSR) on the stock returns and trading behavior of investors, particularly when most businesses have fallen on hard times. This study empirically finds that CSR reputations are associated with higher returns and lower volatilities by comparing the two portfolios which are composed of CSR and non-CSR firms, respectively. We also discover that public pension funds and other institutional investors have liquidated non-CSR stocks more aggressively than CSR stocks. This indicates that institutional investors consider CSR to transform their stock portfolios into less risky ones.

4.
J Anal Toxicol ; 45(9): 993-1005, 2021 Nov 09.
Article in English | MEDLINE | ID: mdl-33196839

ABSTRACT

This study evaluated hair samples from 28 subjects who tested positive for ketamine at Seoul Institute National Forensic Service in Korea between 2016 and 2017. Ketamine in the hair was extracted using a solution of 1% hydrochloric acid in methanol for 16 h. Extracts were analyzed using gas chromatography-mass spectrometry (GC-MS) or liquid chromatography-tandem mass spectrometry (LC-MS-MS). The LC-MS-MS method was validated by determining the limit of detection (LOD), limit of quantification (LOQ), linearity, intra- and inter-accuracy, precision and matrix effect. In 59 ketamine-positive hair or hair segments from 28 ketamine abusers, the ketamine concentration was found to be in the range of 0.011-335.8 ng/mg (mean, 13.6; median, 1.8), and the norketamine concentration was found to be in the range of 0.001-35.7 ng/mg (mean, 7.5; median, 0.44). The ratio of norketamine to ketamine concentrations in hair was in the range of 0.01-1.46 (mean, 0.34; median, 0.26). The distribution of ketamine concentration in hair samples was as follows: 0.01-0.1 ng/mg in 11 samples (18.6%), 0.1-5 ng/mg in 33 samples (55.9%), 5-10 ng/mg in 4 samples (6.8%), 10-15 ng/mg in 2 samples (3.4%), 15-20 ng/mg in 4 samples (6.8%), 40-45 ng/mg in 2 samples (3.4%), 45-50 ng/mg in 1 sample (1.7%) and >100 ng/mg in only 2 samples (3.4%). In the hair of ketamine abusers, 26 of 28 subjects were detected simultaneously ketamine with other drugs, including methylenedioxymethamphetamine (MDMA; n = 9), methamphetamine (MA; n = 3), MDMA/MA (n = 3), MDMA/para-methoxyamphetamine (PMA; n = 3), MDMA/PMA/MA (n = 2), cocaine (n = 1) and other drugs (n = 5, propofol, zolpidem or benzodiazepines). Along with ketamine, other controlled drugs were detected in most of the hair samples: MDMA (60.7%), MA (28.6%), PMA (17.9%), zolpidem (17.9%) and propofol (14.3%) in the frequency of abuse. In conclusion, most of the ketamine abusers (92.9%) were polydrug abusers, who were concomitantly abusing other controlled substances.


Subject(s)
Ketamine , Hair Analysis , Humans , Ketamine/analogs & derivatives , Ketamine/analysis , Republic of Korea , Substance Abuse Detection
5.
Front Chem ; 8: 577371, 2020.
Article in English | MEDLINE | ID: mdl-33282828

ABSTRACT

A 7-step enantioselective synthetic method for preparing (S)(+)-coerulescine is reported through the use of diphenylmethyl tert-butyl α-(2-nitrophenyl)malonate (16% overall yield, >99% ee). Allylation is the key step under phase-transfer catalytic conditions (86% ee). This synthetic method can be used as a practical route for the synthesis of various derivatives of (S)(+)-coerulescine for analyzing its structure-activity relationships against its biological activities.

6.
J Pharmacol Toxicol Methods ; 106: 106931, 2020.
Article in English | MEDLINE | ID: mdl-33091538

ABSTRACT

INTRODUCTION: Hair analysis is useful for monitoring exposure to drugs such as antiepileptics owing to long-term therapy and a high possibility of abuse of drugs, which could be fatal. An effective and rapid analytical method for the simultaneous determination of six barbiturates, as well as phenytoin and topiramate in hair samples was developed and validated by liquid-chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: Three different extraction methods were investigated for the development of an appropriate analytical method. Hair was finely cut and then extracted with methanol, methanol containing 1% hydrochloric acid, and liquid-liquid extraction in acidic condition. RESULTS: There was no significant difference in the matrix effects among these three methods. Recoveries clearly declined in the extraction involving both acidic methanol extraction and a LLE in acidic condition. Methanol incubation was chosen as the appropriate extraction method with acceptable matrix effects and recoveries. After validating the methanol incubation, the limit of detection (LOD) and limit of quantification (LOQ) were determined as 0.01 and 0.02 ng/mg for topiramate and 0.25-0.5 and 0.5-1 ng/mg for the others in hair. The LC-MS/MS method was precise and accurate with a dynamic linear range of 0.02-5 ng/mg for topiramate and 0.5 or 1-50 ng/mg for others. This method was applied to authentic hair samples of two drug users. The hair concentrations of phenobarbital were 0.2-17.1 ng/mg in segmental analysis in one female subject and those of topiramate were 0.19-0.93 ng/mg in another female subject. DISCUSSION: The quantitative method was developed to determine 8 antiepileptics using LC-MS/MS. This method performed hair segmental analysis to provide useful informative and chronological data in both of the forensic and clinical toxicology fields.


Subject(s)
Anticonvulsants/analysis , Hair/chemistry , Substance Abuse Detection/methods , Adult , Barbiturates/analysis , Chromatography, High Pressure Liquid/methods , Female , Humans , Limit of Detection , Middle Aged , Phenytoin/analysis , Reproducibility of Results , Tandem Mass Spectrometry/methods , Topiramate/analysis
7.
Sci Adv ; 6(36)2020 Sep.
Article in English | MEDLINE | ID: mdl-32917620

ABSTRACT

Following the onset of the strong 2014-2016 El Niño, a decade-long increase of the basin-wide sea level and heat content in the subtropical southern Indian Ocean (SIO) in 2004-2013 ended with an unprecedented drop, which quickly recovered during the weak 2017-2018 La Niña. Here, we show that the 2014-2016 El Niño contributed to the observed cooling through an unusual combination of both the reduced heat advection from the Pacific (dominant in the eastern SIO) and the basin-wide cyclonic wind anomaly that led to shoaling of isotherms (dominant in the western SIO). The ensuing recovery was mainly forced by an anticyclonic wind anomaly associated with stronger trade winds that caused deepening of isotherms and upper-ocean warming, effectively suppressing the 2014-2016 cooling signal propagating from the eastern boundary. The results presented here highlight the complexity of the SIO heat content variability driven by remote and local forcing.

8.
Int J Mol Sci ; 21(17)2020 Aug 21.
Article in English | MEDLINE | ID: mdl-32839415

ABSTRACT

Methamphetamine (MA) is a highly addictive central nervous system stimulant. Drug addiction is not a static condition but rather a chronically relapsing disorder. Hair is a valuable and stable specimen for chronic toxicological monitoring as it retains toxicants and metabolites. The primary focus of this study was to discover the metabolic effects encompassing diverse pathological symptoms of MA addiction. Therefore, metabolic alterations were investigated in human hair following heavy MA abuse using both targeted and untargeted mass spectrometry and through integrated network analysis. The statistical analyses (t-test, variable importance on projection score, and receiver-operator characteristic curve) demonstrated that 32 metabolites (in targeted metabolomics) as well as 417 and 224 ion features (in positive and negative ionization modes of untargeted metabolomics, respectively) were critically dysregulated. The network analysis showed that the biosynthesis or metabolism of lipids, such as glycosphingolipids, sphingolipids, glycerophospholipids, and ether lipids, as well as the metabolism of amino acids (glycine, serine and threonine; cysteine and methionine) is affected by heavy MA abuse. These findings reveal crucial metabolic effects caused by MA addiction, with emphasis on the value of human hair as a diagnostic specimen for determining drug addiction, and will aid in identifying robust diagnostic markers and therapeutic targets.


Subject(s)
Amphetamine/analysis , Central Nervous System Stimulants/analysis , Hair/chemistry , Methamphetamine/analysis , Substance-Related Disorders/diagnosis , Adult , Amino Acids/chemistry , Amino Acids/classification , Amino Acids/isolation & purification , Amino Acids/metabolism , Amphetamine/administration & dosage , Amphetamine/metabolism , Case-Control Studies , Central Nervous System Stimulants/administration & dosage , Central Nervous System Stimulants/metabolism , Glycerophospholipids/chemistry , Glycerophospholipids/classification , Glycerophospholipids/isolation & purification , Glycerophospholipids/metabolism , Glycosphingolipids/chemistry , Glycosphingolipids/classification , Glycosphingolipids/isolation & purification , Glycosphingolipids/metabolism , Humans , Lipid Metabolism/physiology , Male , Metabolomics/methods , Methamphetamine/administration & dosage , Methamphetamine/metabolism , Middle Aged , Principal Component Analysis , Sphingolipids/chemistry , Sphingolipids/classification , Sphingolipids/isolation & purification , Sphingolipids/metabolism , Substance Abuse Detection/methods , Substance-Related Disorders/metabolism , Tandem Mass Spectrometry
9.
Sci Rep ; 9(1): 178, 2019 01 17.
Article in English | MEDLINE | ID: mdl-30655587

ABSTRACT

The northern Gulf of Mexico (GoM) is a region strongly influenced by river discharges of freshwater and nutrients, which promote a highly productive coastal ecosystem that host commercially valuable marine species. A variety of climate and weather processes could potentially influence the river discharges into the northern GoM. However, their impacts on the coastal ecosystem remain poorly described. By using a regional ocean-biogeochemical model, complemented with satellite and in situ observations, here we show that El Niño - Southern Oscillation (ENSO) is a main driver of the interannual variability in salinity and plankton biomass during winter and spring. Composite analysis of salinity and plankton biomass anomalies shows a strong asymmetry between El Niño and La Niña impacts, with much larger amplitude and broader areas affected during El Niño conditions. Further analysis of the model simulation reveals significant coastal circulation anomalies driven by changes in salinity and winds. The coastal circulation anomalies in turn largely determine the spatial extent and distribution of the ENSO-induced plankton biomass variability. These findings highlight that ENSO-induced changes in salinity, plankton biomass, and coastal circulation across the northern GoM are closely interlinked and may significantly impact the abundance and distribution of fish and invertebrates.

10.
Geophys Res Lett ; 44(2): 927-936, 2017 Jan 28.
Article in English | MEDLINE | ID: mdl-29200536

ABSTRACT

The persistent energy imbalance at the top of the atmosphere, inferred from satellite measurements, indicates that the Earth's climate system continues to accumulate excess heat. As only sparse and irregular measurements of ocean heat below 2000 m depth exist, one of the most challenging questions in global climate change studies is whether the excess heat has already penetrated into the deep ocean. Here we perform a comprehensive analysis of satellite and in situ measurements to report that a significant deep-ocean warming occurred in the subtropical South Pacific Ocean over the past decade (2005-2014). The local accumulation of heat accounted for up to a quarter of the global ocean heat increase, with directly and indirectly inferred deep ocean (below 2000 m) contribution of 2.4 ± 1.4 and 6.1-10.1 ± 4.4%, respectively. We further demonstrate that this heat accumulation is consistent with a decade-long intensification of the subtropical convergence, possibly linked to the persistent La Niña-like state.

11.
J Korean Med Sci ; 32(12): 2069-2072, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29115093

ABSTRACT

Congenital cardiovascular anomalies, such as dextrocardia, persistent left superior vena cava (SVC), and pulmonary artery (PA) sling, are rare disorders. These congenital anomalies can occur alone, or coincide with other congenital malformations. In the majority of cases, congenital anomalies are detected early in life by certain signs and symptoms. A 56-year-old man with no previous medical history was admitted due to recurrent wide QRS complex tachycardia with hemodynamic collapse. A chest radiograph showed dextrocardia. After synchronized cardioversion, an electrocardiogram revealed Wolff-Parkinson-White (WPW) syndrome. Persistent left SVC, PA sling, and right tracheal bronchus were also detected by a chest computed tomography (CT) scan. He was diagnosed with paroxysmal supraventricular tachycardia (PSVT) associated with WPW syndrome, and underwent radiofrequency ablation. We reported the first case of situs solitus dextrocardia coexisting with persistent left SVC, PA sling and right tracheal bronchus presented with WPW and PSVT in a middle-aged adult. In patients with a cardiovascular anomaly, clinicians should consider thorough evaluation of possibly combined cardiovascular and airway malformations and cardiac dysrhythmia.


Subject(s)
Tachycardia, Paroxysmal/diagnosis , Wolff-Parkinson-White Syndrome/diagnosis , Catheter Ablation , Dextrocardia/diagnosis , Dextrocardia/diagnostic imaging , Electrocardiography , Humans , Male , Middle Aged , Tachycardia, Paroxysmal/etiology , Tachycardia, Paroxysmal/surgery , Tomography, X-Ray Computed , Vena Cava, Superior/diagnostic imaging , Wolff-Parkinson-White Syndrome/complications
12.
Korean J Thorac Cardiovasc Surg ; 50(1): 50-53, 2017 Feb.
Article in English | MEDLINE | ID: mdl-28180105

ABSTRACT

A mixed infection of Mycobacterium abscessus subsp. abscessus (Mab) and Mycobacterium tuberculosis (MTB) in the lung is an unusual clinical manifestation and has not yet been reported. A 61-year-old woman had been treated for Mab lung disease and concomitant pneumonia, and was diagnosed with pulmonary tuberculosis (PTB). Despite both anti-PTB and anti-Mab therapy, her entire left lung was destroyed and collapsed. She underwent left pneumonectomy and received medical therapy. We were able to successfully treat her mixed infection by pneumonectomy followed by inhaled amikacin therapy. To the best of our knowledge, thus far, this is the first description of a mixed Mab and MTB lung infection.

13.
J Anal Toxicol ; 40(6): 460-5, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27197984

ABSTRACT

Rotenone is a neurotoxin derived from Derris roots or yam bean of genus Derris or Lonchocarpus It is known to cause Parkinson-like symptoms and is a potent electron transport inhibitor. Rotenone was detected in postmortem specimens in a fatal case of rotenone poisoning with an organic pesticide by liquid chromatography-tandem mass spectrometry with an information-dependent acquisition and MS-MS library search. The forensic specimens were prepared by solid-phase extraction with a Bond Elut(®) Certify cartridge. The mobile phase comprised 5 mM ammonium formate in 10% methanol and 5 mM ammonium formate in 90% methanol. The assay was linear over the range from 0.01 to 1.0 mg/L (r(2) = 0.995). The limit of detection and quantitation in the blood were 0.001 mg/L (signal-to-noise, S/N = 3) and 0.003 mg/L (S/N = 10), respectively. The intraday accuracy and precision for rotenone that were determined by five replicates at 0.02, 0.10 and 1.0 mg/L in blood were <15.0% of bias and <9.0% of CV, respectively. The interday accuracy and precision for rotenone that were determined by seven replicates at 0.02, 0.10 and 1.0 mg/L in blood were <18.0% of bias and <17.0% of CV, respectively. Relative recovery with 0.02, 0.1 and 1.0 mg/L in blood was 104.2, 103.3 and 81.6% (n = 6), respectively. The described method was applied for the determination of rotenone in a fatal case of intoxication of a 33-year-old man who was found dead on a bed in a temporary house. In this case study, the concentrations of rotenone in heart blood (HB), peripheral blood (PB), gastric contents and vitreous humor were 0.77 mg/L, 0.02 mg/L, 126.4 mg/kg and 0.003 mg/L, respectively. The rotenone concentration ratio of the HB/PB was 38.8 and that of gastric contents/PB was 6412.3, suggesting a massive ingestion of rotenone with postmortem redistribution. This study is the report of rotenone detection in a fatal case with the ingestion of the organic insecticide containing rotenone.


Subject(s)
Insecticides/metabolism , Rotenone/metabolism , Adult , Chromatography, Liquid , Fatal Outcome , Forensic Toxicology , Humans , Insecticides/poisoning , Male , Rotenone/poisoning
14.
Forensic Sci Int ; 259: 69-76, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26760907

ABSTRACT

Phenylalkylamine derivatives, such as methamphetamine (MA), 3,4-methylenedioxymethamphetamine (MDMA), phentermine, fenfluramine, phendimetrazine, amfepramone, and ketamine, are widely abused recreational or anorectic drugs in Korea, and their abuse has become a serious social problem. Hair is a useful specimen to prove chronic use and liquid chromatography-tandem mass spectrometry (LC-MS/MS) has recently become a more popular tool for hair analysis due to sensitivity and simplicity in sample preparation. In order to overcome limitations of standard reversed-phase column to separate low molecular weight amines, we adopted a multi-mode reversed-phase column, Scherzo SS-C18, which was composed of strong ionic ligands and C18 ligands, and used pH gradient elution to separate seven psychotropic phenylalkylamines and their metabolites. The essential validation parameters including selectivity, LOD, LLOQ, linearity, intra- and inter-assay precision and accuracy, recovery, and the matrix effect were satisfactory. The LODs ranged from 0.1ng/5mg hair (diethylnorephedrine, fenfluramine, ketamine, and MA) to 0.5ng/5mg hair (amfepramone, MDA, phendimetrazine, and phentermine). The LLOQs were 1ng/5mg hair for all analytes. The developed method was successfully applied to determination of phenylalkylamines in authentic hair samples analyzed previously by a routine gas chromatography/mass spectrometry (GC-MS) method. A good correlation was observed between the two methods, with a slope near one.


Subject(s)
Chromatography, Liquid/methods , Chromatography, Reverse-Phase/methods , Hair/chemistry , Phenethylamines/analysis , Psychotropic Drugs/analysis , Tandem Mass Spectrometry/methods , Adult , Female , Humans , Hydrogen-Ion Concentration , Male , Middle Aged , Young Adult
15.
Biomed Mater Eng ; 26 Suppl 1: S803-9, 2015.
Article in English | MEDLINE | ID: mdl-26406077

ABSTRACT

Essential tremor is an involuntary trembling of body limbs in people without tremor-related disease. In previous study, suppression of tremor by sensory electrical stimulation was confirmed on the index finger. This study investigates the effect of sensory stimulation on multiple segments and joints of the upper limb. It denotes the observation regarding the effect's continuity after halting the stimulation. 18 patients with essential tremor (8 men and 10 women) participated in this study. The task, "arms stretched forward", was performed and sensory electrical stimulation was applied on four muscles of the upper limb (Flexor Carpi Radialis, Extensor Carpi Radialis, Biceps Brachii, and Triceps Brachii) for 15 seconds. Three 3-D gyro sensors were used to measure the angular velocities of segments (finger, hand, and forearm) and joints (metacarpophalangeal and wrist joints) for three phases of pre-stimulation (Pre), during-stimulation (On), and 5 minute post-stimulation (P5). Three characteristic variables of root-mean-squared angular velocity, peak power, and peak power frequency were derived from the vector sum of the sensor signals. At On phase, RMS velocity was reduced from Pre in all segments and joints while peak power was reduced from Pre in all segments and joints except for forearm segment. Sensory stimulation showed no effect on peak power frequency. All variables at P5 were similar to those at On at all segments and joints. The decrease of peak power of the index finger was noted by 90% during stimulation from that of On phase, which was maintained even after 5 min. The results indicate that sensory stimulation may be an effective clinical method to treat the essential tremor.


Subject(s)
Afferent Pathways/physiopathology , Electric Stimulation Therapy/methods , Essential Tremor/physiopathology , Essential Tremor/therapy , Fingers/physiopathology , Muscle, Skeletal/physiopathology , Aged , Essential Tremor/complications , Essential Tremor/diagnosis , Female , Fingers/innervation , Humans , Male , Muscle, Skeletal/innervation , Sensory Thresholds , Treatment Outcome , Tremor/etiology , Tremor/physiopathology , Tremor/therapy
16.
Glob Chang Biol ; 21(9): 3389-401, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25833698

ABSTRACT

Projections of climate change impacts on coral reefs produced at the coarse resolution (~1°) of Global Climate Models (GCMs) have informed debate but have not helped target local management actions. Here, projections of the onset of annual coral bleaching conditions in the Caribbean under Representative Concentration Pathway (RCP) 8.5 are produced using an ensemble of 33 Coupled Model Intercomparison Project phase-5 models and via dynamical and statistical downscaling. A high-resolution (~11 km) regional ocean model (MOM4.1) is used for the dynamical downscaling. For statistical downscaling, sea surface temperature (SST) means and annual cycles in all the GCMs are replaced with observed data from the ~4-km NOAA Pathfinder SST dataset. Spatial patterns in all three projections are broadly similar; the average year for the onset of annual severe bleaching is 2040-2043 for all projections. However, downscaled projections show many locations where the onset of annual severe bleaching (ASB) varies 10 or more years within a single GCM grid cell. Managers in locations where this applies (e.g., Florida, Turks and Caicos, Puerto Rico, and the Dominican Republic, among others) can identify locations that represent relative albeit temporary refugia. Both downscaled projections are different for the Bahamas compared to the GCM projections. The dynamically downscaled projections suggest an earlier onset of ASB linked to projected changes in regional currents, a feature not resolved in GCMs. This result demonstrates the value of dynamical downscaling for this application and means statistically downscaled projections have to be interpreted with caution. However, aside from west of Andros Island, the projections for the two types of downscaling are mostly aligned; projected onset of ASB is within ±10 years for 72% of the reef locations.


Subject(s)
Anthozoa/physiology , Climate Change , Conservation of Natural Resources , Coral Reefs , Animals , Caribbean Region , Geographic Mapping , Models, Biological , Population Dynamics
17.
J Arthroplasty ; 29(12): 2397-401, 2014 Dec.
Article in English | MEDLINE | ID: mdl-24726172

ABSTRACT

Although cemented tibial fixation of total knee arthroplasty accepted as the gold standard, cementless fixation as a means to supplement disadvantages of cemented fixation continues to be of interest to clinicians. One hundred sixty-eight consecutive knees undergoing primary knee arthroplasty for osteoarthritis were randomly assigned to receive either a cemented (86 knees) or cementless (82 knees) fixation of tibial component. We report the outcomes at 8 to 11years (mean, 9.5). The mean KSS, the HSS score, the mean WOMAC, the mean ranges of knee movement and radiological results were similar in both groups. No osteolysis was identified in either group. The rate of survival of the femoral and tibial components was 100% in both groups at final follow-up.


Subject(s)
Arthroplasty, Replacement, Knee/methods , Knee Prosthesis , Osteoarthritis, Knee/surgery , Aged , Aged, 80 and over , Bone Cements , Cementation , Female , Follow-Up Studies , Humans , Knee Joint/surgery , Male , Middle Aged , Prosthesis Design , Tibia/surgery , Treatment Outcome
18.
Forensic Sci Int ; 233(1-3): 333-7, 2013 Dec 10.
Article in English | MEDLINE | ID: mdl-24314538

ABSTRACT

Propofol, a short-acting and sedative-hypnotic agent, induces and maintains anesthesia. Since it is known to produce mild euphoria and hallucinations, the recreational use of propofol has been a big issue in Korea. Furthermore, many deaths have occurred due to its abuse and misuse. In order to study the prevalence of abuse and deaths due to propofol, all autopsy cases conducted between 2005 and 2010 at the NFS (National Forensic Service, Korea) were monitored by checking its concentrations in the blood. Propofol was detected in 131 cases (0.88%) out of 14,673 autopsied cases within 6 years. Propofol alone was detected in 49 of 131 fatal cases, while the combination of drugs was detected with propofol in the remaining 82 cases. The concentrations of propofol from autopsied cases ranged from 0.05 to 8.83 mg/L (mean 1.66; median 0.9) and from 0.08 to 8.65 mg/L (mean 1.71; median 1.05) in the heart (n=31) and the femoral blood (n=32), respectively. The investigation of the ratio of heart to femoral blood and the difference between the concentrations in heart and femoral blood (n=15) from the same body revealed the ratio from 0.45 to 3.66 (mean 1.53; median 1.40). The autopsy resulted in accidental death after self-administration in 16 autopsied cases among 131 autopsied cases. In 16 cases, their ages ranged from 17 to 56 and 75% of them were in their 20's and 30's and 75% were female. Half of them were medical personnel including 19% of doctors and 38% of nurses. The combination of drugs was detected in 6 cases. Fluoxetine was detected in three and vecuronium was detected in two along with propofol. The cause of death in 14 cases was drug intoxication, while that in 2 cases was hanging. Due to its prevalence, Korea has become the first country that regulates propofol as a psychotropic substance.


Subject(s)
Hypnotics and Sedatives/blood , Propofol/blood , Substance-Related Disorders/epidemiology , Adolescent , Adult , Drug Overdose/mortality , Female , Forensic Toxicology , Gas Chromatography-Mass Spectrometry , Humans , Hypnotics and Sedatives/poisoning , Male , Middle Aged , Nurses/statistics & numerical data , Physicians/statistics & numerical data , Propofol/poisoning , Republic of Korea/epidemiology , Substance-Related Disorders/blood , Young Adult
19.
Anal Bioanal Chem ; 405(10): 3185-94, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23371534

ABSTRACT

The chemical castration law, which targets child molesters with recidivism, was introduced in Korea in 2011. For this, leuprolide, a gonadotropin-releasing hormone agonist, is used to decrease testosterone production and suppress libido. In order to achieve efficient law enforcement, it is necessary to monitor intentional ingestion of drugs that antagonize the effect of leuprolide. Therefore, an analytical method for the simultaneous detection of mirodenafil, sildenafil, tadalafil, udenafil, vardenafil, icariin, alprostadil, and yohimbine, which are the major impotence treatment drugs, legitimately or otherwise, in Korea, as well as their selected metabolites, in human urine was established and validated using liquid chromatography-tandem mass spectrometry (LC-MS/MS). First, different sample preparation methods, two solid-phase extractions with different cartridges and protein precipitation, were compared and protein precipitation was chosen for the entire study because it showed better matrix effects and recoveries. Thus, the drugs and metabolites in urine were extracted by protein precipitation and then filtered and analyzed by LC-MS/MS with polarity switching electrospray ionization. The validation results of selectivity, matrix effect, recovery, linearity, intra- and inter-assay precision and accuracy were satisfactory. The limits of detection ranged from 0.25 to 10 ng/mL, and the limits of quantification were 2.5 to 50 ng/mL. The drugs and metabolites in urine did not show any degradation under storage for 7 and 15 days at 4 and -20 °C as well as after three freeze-thaw cycles. The developed method will be very useful for monitoring the illegal use of impotence treatment drugs.


Subject(s)
Chromatography, High Pressure Liquid/methods , Leuprolide/antagonists & inhibitors , Tandem Mass Spectrometry/methods , Vasodilator Agents/urine , Humans , Leuprolide/metabolism , Leuprolide/urine , Male , Vasodilator Agents/metabolism
20.
Forensic Sci Int ; 219(1-3): 265-71, 2012 Jun 10.
Article in English | MEDLINE | ID: mdl-22284073

ABSTRACT

We described the findings of a study into the post-mortem redistribution (PMR) of 76 drugs found in 129 drug-related cases between 2006 and 2009. Seventy six drugs (psychotropic drugs (n=14), antidepressants (n=9), sedatives (n=6) and so on) were simultaneously quantified in cardiac and peripheral blood by gas chromatography-mass spectrometry (GC/MS) or liquid chromatography-tandem mass spectrometry (LC/MS/MS). The absence, possibility or presence of PMR of drugs was determined according to the ratios of cardiac to femoral blood concentrations (C/P ratios). Proxyphylline (C/P ratio: 0.85) showed no PMR; carbamazepine was not subject to PMR; a potential for PMR of lorazepam and mirtrazapine cannot be excluded; chlordiazepoxide is subject to PMR; acetaminophen and alprazolam exhibit minimal PMR; amitriptyline and benztropine exhibit PMR. Codeine (C/P ratio: 4.9), zolpidem (C/P ratio: 3.74), chlorpromazine (C/P ratio: 2.97), fluoxetine (C/P ratio: 2.83) and propranolol (C/P ratio: 2.72) had the largest C/P ratios. Postmortem drug concentrations showed variations depending on sampling sites and characteristics of the drugs. It is continuously necessary to analyze commonly used or abused drugs in simultaneously collected cardiac and peripheral blood to establish significant reference values for PMR. These findings can be used to reach a conclusion about the cause and manner of death.


Subject(s)
Pharmaceutical Preparations/blood , Pharmacokinetics , Postmortem Changes , Chromatography, Liquid , Forensic Toxicology , Gas Chromatography-Mass Spectrometry , Humans , Reference Values , Tandem Mass Spectrometry
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