Inverted U-Shaped Relationship between Obesity Parameters and Bone Mineral Density in Korean Adolescents.

As the association between obesity and bone health remains controversial in children and adolescents, we investigate the effects of obesity parameters on bone mineral density (BMD) in 2060 Korean adolescents who participated in the 2008-2011 Korea National Health and Nutrition Examination Survey (KNHANES). Multiple regression analysis and analysis of covariance (ANCOVA) were conducted to examine both the linear and non-linear associations between total-body-less-head (TBLH) BMD and four obesity parameters: body mass index, waist circumference, waist-to-height ratio, and total-body fat mass (FM). In a multiple linear regression analysis adjusted for age, menarcheal status (in females only), and total-body lean mass, there was no significant linear association between obesity parameters and TBLH BMD, except for total-body FM in males. However, upon adding a second-order polynomial term for each obesity parameter, a significant quadratic relationship between all obesity parameters and TBLH BMD was observed, with the corresponding quadratic term being negative. The results of ANCOVA also revealed an inverted U-shaped relationship between each obesity parameter and TBLH BMD. Our findings suggest the existence of an optimal range of obesity parameters for developing or maintaining optimal bone health in Korean Adolescents. Deviation from this range, in either direction (being underweight or having obesity), may compromise bone health.

Variations in aragonite saturation state and its controlling factors in the South Yellow Sea in spring and autumn.

To assess the progression of ocean acidification in the South Yellow Sea (SYS), the aragonite saturation state (Ωarag) was determined from dissolved inorganic carbon (DIC) and total alkalinity (TA) in the surface and bottom waters of the SYS in spring and autumn. The Ωarag exhibited large spatiotemporal variations in the SYS; DIC was a major factor controlling the Ωarag variations, whereas temperature, salinity, and TA were minor factors. Surface DIC concentrations were mainly influenced by the lateral transport of the DIC-enriched Yellow River waters and DIC-depleted East China Sea Surface Water; bottom DIC concentrations were affected by aerobic remineralization in spring and autumn. Ocean acidification is now seriously progressing in the SYS, particularly in the Yellow Sea Bottom Cold Water (YSBCW) where the mean value of Ωarag substantially decreased from 1.55 in spring to 1.22 in autumn. All Ωarag values measured in the YSBCW in autumn were lower than the critical threshold value of 1.5 necessary for the survival of calcareous organisms.

The effect of COVID-19 pandemic on the length of stay and outcomes in the emergency department.

OBJECTIVE: This study aimed to evaluate the change in length of stay (LOS) in the emergency department (ED) and outcomes during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: This is a single-center, retrospective observational study. We compared ED LOS and outcomes in patients aged ≥19 years who presented to the ED of Soonchunhyang University Bucheon Hospital, a single tertiary university hospital, between January and December in 2018, 2019, and 2020. We included patients who were diagnosed with fever, pneumonia, and sepsis in the ED, based on the International Statistical Classification of Diseases and Related Health Problems 10th Revision. We also compared the LOS and outcomes of overall ED patients in 2019 (before COVID-19) and in 2020 (after COVID-19). RESULTS: A total of 5,061 patients with fever, pneumonia, and sepsis were analyzed. The LOS in the ED in 2020 significantly increased compared with 2018 and 2019 (177.0±115.0 minutes in 2018, 154.0±85.0 minutes in 2019, and 208.0±239.0 minutes in 2020). The proportion of patients who were transferred to other hospitals in 2020 (2.1%) increased compared with 2018 (0.8%) and 2019 (0.7%). Intensive care unit admission significantly increased in 2020 (13.7%) compared with 2019 (10.3%). Among all ED patients, ED LOS in 2020 was longer than in 2019, particularly in patients who were admitted and then transferred to another hospital. Intensive care unit admission (4.4% vs. 5.0%), transfer rate (0.7% vs. 0.9%), and ED mortality (0.6% vs. 0.7%) also significantly increased. CONCLUSION: The ED LOS, time to intensive care unit admissions, time to transfer to other hospitals, and ED mortality significantly increased during the COVID-19 pandemic.

Is it enough for COVID-19 screening test? Limitation of swab test and general characteristics of mild symptom patients.

The most common method for SARS-CoV-2 testing is throat or nasal swabbing by real-time reverse transcription polymerase chain reaction (RT-PCR) assay. In South Korea, drive-through swab test is used for screening system and community treatment centers (CTCs), which admit and treat confirmed COVID-19 patients with mild symptoms, are being used. This retrospective study was conducted on patients admitted to a CTC on March 6, 2020. A total of 313 patients were admitted. The nasal and throat swabs were collected from the upper respiratory tract, and a sputum test was performed to obtain lower respiratory samples. The positive rate of the first set of test, sputum test was higher than that of the swab test (p = 0.011). In the second set of test, 1 week after the first ones, the rate of positive swab tests was relatively high (p = 0.026). In the first set of test, 66 of 152 (43.4%) patients showed 24-h consecutive negative swab test results, when the sputum test results were considered together, that number fell to 29 patients (19.1%) (p < 0.001). Also, in the second set of test, 63 of 164 (38.4%) patients met the discharge criteria only when the swab test was considered; that number fell to 30 (18.3%) when the sputum test results were also considered (p < 0.001). Using the swab test alone is insufficient for screening test and discharge decision. Patients who may have positive result in the sputum test can be missed.

Overseas Air Medical Repatriation of National Soccer Players Infected With Coronavirus Disease 2019 and Contacted Staff From Austria to South Korea.

Korea rarely has a system to transport patients from abroad. However, single-patient transfers are steadily being performed, and there was an experience of transferring a large number of personnel regardless of whether they were confirmed or not due to coronavirus disease 2019. Recently, a national soccer game was held abroad, and a total of 8 players and staff were infected. A total of 15 people were transported through a charter fully equipped with quarantine equipment by a medical response team with experience in air transport.

Excessive Daytime Sleepiness and Its Associated Factors among Emergency Medicine Residents in South Korea: A Nationwide Survey.

OBJECTIVE: Excessive daytime sleepiness (EDS) in emergency medicine (EM) residents is associated with patient safety. However, studies regarding EDS in EM residents are limited. The objective of this study was to identify the prevalence of EDS and its associated factors among EM residents. METHODS: Epworth sleepiness scale scores, working hours per week (WHW), night working days per month, working environment, and depression were analyzed using data from the 2019 Korean Emergency Medicine Resident Survey. RESULTS: The survey response rate was 63.8% (384/601). Among 241 respondents, the prevalence rate of EDS was 32.4%. Multivariable logistic regression analysis demonstrated that WHW (odds ratio [OR] = 1.03, 95% confidence interval [CI] = 1.01-1.06) and depression (OR = 3.64, 95% CI = 1.91-6.96) had increased ORs for EDS. CONCLUSIONS: Approximately one-third of EM residents had EDS. Depression and WHW were the associated factors.

Preventive effects of seat belts on traumatic brain injury in motor vehicle collisions classified by crash severities and collision directions.

PURPOSE: This study aimed to measure the preventive effect of seat belt on traumatic brain injury (TBI) and to compare the effect according to the crash severities and collision directions. METHODS: Korea In-Depth Accident Study (KIDAS) has collected vehicle and demographic data on injured occupants involved in motor vehicle collisions (MVCs) who visited three emergency medical centers for calendar years 2011-2016. Primary and secondary end points were TBI (abbreviated injury score 2+) and in-hospital mortality. Crush extent (CE) was classified into 1-2, 3-4, 5-6, and 7-9 according to the crash severity. We calculated adjusted odds ratios (ORs) of seat belts and CE for study outcomes and developed an interaction model in each collision direction using multivariate logistic regression analysis. RESULTS: Of the 2,245 occupants who were injured in MVCs, 295 (13.1%) occupants sustained TBI. In univariate analysis, old age, unbelted status, lateral collision, and higher CE were factors associated with TBI in MVCs. Occupants with belted status was less likely to have TBI and in-hospital mortality compared with those with unbelted status [AORs (95% CI) 0.48 (0.37-0.62) and 0.49 (0.30-0.81), respectively]. In interaction analysis, preventive effects of seat belts on TBI from MVCs were retained within CE 5-6 in frontal MVCs and within CE 1-2 in near side lateral MVCs, and those of seat belts on in-hospital mortality were reserved within CE 3-4 in frontal and rollover MVCs. CONCLUSIONS: The preventive effects of seat belts on TBI and in-hospital mortality are preserved within a limited crash severity in each collision direction.

Efficacy of Cartoons as a Distraction Technique for Children Undergoing Suture of Facial Lacerations in the Emergency Department.

PURPOSE: To show the efficacy of cartoon as a distraction technique in suturing a child patient in the emergency room. METHODS: We studied children aged 2 to 8 years who had sustained a facial laceration 3 cm or less that required suturing from September 2015 to November 2016. We used local anesthesia and attempted to place the sutures without sedation while showing the children cartoons instead. If the first attempt failed, 1 more attempt was made. The patients were divided into 3 groups: success, success on second attempt, and failure. Age, location and size of the wound, and scores on the FACES Pain Rating Scale (FPS) before and after local anesthesia were recorded. RESULTS: The study included 106 children. Cartoon distraction was most effective for those aged 3 to 6 years (4.6 ± 1.9 years). The second-attempt group tended to be older, whereas the failure group was much younger (mean age, 7.4 ± 1.0 vs 2.7 ± 1.8 years). The FPS-R score differed widely among the groups. The success group tended to have a low score before and after local anesthetic injection (4.1 ± 2.0 and 3.1 ± 1.3), whereas the second-attempt and failure groups had much higher scores after injection (8.0 ± 1.7 and 8.8 ± 0.8; 5.2 ± 2.6 and 9.3 ± 0.8). CONCLUSIONS: Cartoon distraction techniques can reduce the treatment duration and number of assistants, which also makes it appropriate for the emergency room. In addition, our results indicate that the pre-/post-local injection FPS score is a good predictor of success.

Comparison of the characteristics and injury severity of passengers in motor vehicle accidents between urban and rural cities in South Korea.

OBJECTIVE: To analyze motor vehicle accidents in two different traffic environments and compare differences in severity between both regions. METHODS: Injury data were collected by the Emergency Medicine and Traffic Accident Research Team as part of the Korean In-Depth Accident Study. Patients admitted to emergency medical centers located in Wonju, Gangwon province (population 345,143, rural, group A) and Bucheon, Gyeonggi province (population 870,735, urban, group B) between January 2011 and December 2017 were included for analysis. Injury severity was classified into four categories based on Injury Severity Score (ISS): minor (1≤ <9), moderate (9≤ <15), major (15≤ <25), and critical (≥25). RESULTS: Overall, 1,807 patients were included (group A, 1,484; group B, 323). There was a higher proportion of daytime accidents, accidents involving larger cars, passenger injuries, and accidents involving lack of seat belt use in group A than in group B. The mean ISS value was 8.98 in group A and 4.62 in group B (P<0.001). Minor (20.4% vs. 10.8%) and major/critical (15.7% vs. 5.0%) injuries were more frequent in group A than group B (P<0.001). Patient ratios (A/B) for each ISS classification were 0.76 (minor), 1.89 (moderate), 3.43 (major), and 2.77 (critical). The factors showing a significant relationship with severity were driver's seat (P=0.037) and no seat belt (P<0.001). CONCLUSION: Patients in a rural city who visited the emergency room owing to motor vehicle accidents had more severe injuries than those in an urban city.

Epidemiological and clinical profile of Korean travelers receiving international medical repatriation.

The aim of this study was to investigate the experiences of medical transportation of Korean travelers who suffered accidents abroad and then transferred home by our aeromedical team.We collected demographic and clinical data on patients injured while traveling abroad from January 2013 to July 2017. Descriptive analyses based on 4 different transportation methods and transport time since hospitalization were performed.A total of 33 patients were repatriated during the study period. Of these, 28 (84.8%) were trauma cases with pedestrian injuries being the most common (11 cases; 39.3%). Twenty patients were repatriated by flight-stretchers, 6 by flight-prestige, 2 by ship, and 5 by air ambulance. The air ambulance was the most expensive (average 61,124 US Dollars) mode of transportation (P = .001) and the ship took the longest time (14 hours) to transport patients back to Korea from regions with similar distance (P = .0023).We experienced medical repatriation of 33 seriously injured Korean travelers back to South Korea. Transfer time should be an important considering factor and directly contacting and communicating with the specialized staff of foreign hospitals could also be very important to reduce unnecessary overseas hospital stay and cost incidence.

Should Let Them Go? Study on the Emergency Department Discharge of Patients Who Attempted Suicide.

OBJECTIVE: The purpose of this study was to analyze the characteristics and factors of voluntary discharged patients after suicide attempt and analyze the effectiveness of follow-up measures. METHODS: Total 504 adult patients aged 14 years and over, who visited a local emergency medical center from September 1, 2013 to December 31, 2015 were enrolled and retrospectively reviewed. We analyzed the relationship with voluntary discharge group (VDG) among basic characteristics, suicidal attempt variables, outcome variables related to suicide attempts, and treatment related variables comparing with normal discharge group (NDG). RESULTS: Of the total 504 suicide attempts, three hundred eleven (61.7%) patients were VDG and 193 (38.2%) were NDG. The proportion of patients who completed the community service linkage were 18.7% (36/193) in NDG, compared with 7.7% (24/311) in VDG (p<0.05). In addition, the ratio of the patients who visited psychiatric outpatient department in NDG were 57.0% (110/193), more than four times as likely as 14.5% (45/311) in VDG (p<0.05). CONCLUSION: Over sixty percent of suicide attempters discharged against medical advice. Further various aspects of national supportive measures including strengthening case management service should be considered.

Safety and Efficacy of Tolvaptan in Korean Patients with Hyponatremia Caused by the Syndrome of Inappropriate Antidiuretic Hormone.

BACKGROUND: The aim of this multicenter study was to evaluate the safety and efficacy of tolvaptan (TLV) in Korean patients with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). METHODS: Of 51 enrolled patients with SIADH, 39 patients (16 female patients, aged 70.8 ± 11.3 years) were included in an intention to treat analysis. All patients received 15 mg/day as the initial dose, and the dose was then increased up to 60 mg/day (as needed) until day 4. RESULTS: Serum sodium increased significantly from baseline during the first 24 hours (126.8 ± 4.3 vs. 133.7 ± 3.8 mmol/L, P < 0.001), rose gradually between days 1 and 4 (133.7 ± 3.8 vs. 135.6 ± 3.6 mmol/L, P < 0.05), and then plateaued until day 11 (136.7 ± 4.5 mmol/L). The correlation between the change in serum sodium for the first 24 hours and initial serum sodium concentration was significant (r = -0.602, P < 0.001). In severe hyponatremia (< 125 mmol/L), the change was significantly higher (11.1 ± 4.8 mmol/L) than in moderate (6.4 ± 2.5 mmol/L, P < 0.05) or mild hyponatremia (4.3 ± 3.3 mmol/L, P < 0.01). In addition, logistic regression analysis showed that body weight (odds ratio [OR], 0.858; 95% confidence interval [CI], 0.775-0.976; P = 0.020) and body mass index (BMI) (OR, 0.692; 95% CI, 0.500-0.956; P = 0.026) were associated with rapid correction. No serious adverse events were reported, but in 13% of patients hyponatremia was overcorrected. CONCLUSION: TLV is effective in correcting hyponatremia and well-tolerated in Korean patients with SIADH. However, those with low body weight, low BMI or severe hyponatremia, could be vulnerable to overcorrection with the initial dose of 15 mg TLV.

A predictive model to analyze factors affecting the presence of mild whiplash-associated disorders in minor motor vehicle crashes based on the Korean In-Depth Accidents Study (KIDAS) Database.

OBJECTIVES: We aimed to analyze factors affecting the severity of mild whiplash-associated disorders (WADs) and to develop a predictive model to evaluate the presence of mild WAD in minor motor vehicle crashes (MVCs). METHODS: We used the Korean In-Depth Accident Study (KIDAS) database, which collects data from 4 regional emergency centers, to obtain data from 2011 to 2017. The Collision Deformation Classification code was obtained as vehicle's damage information, and Abbreviated Injury Scale (AIS), Maximum Abbreviated Injury Scale (MAIS), and Injury Severity Score (ISS) were used as occupant's injury information. The degree of WAD was determined using the Quebec Task Force (QTF) classification, comprised of 5 stages (QTF 0-4), depending on the occupant's pain and the physician's findings. QTF 1 was defined as mild WAD, and we used QTF 0 to define those who were uninjured. For KIDAS data between 2011 and 2016, a logistic regression model was used to identify factors affecting the occurrence of mild WAD and a predictive model was constructed. Internal validity was estimated using random bootstrapping, and external validity was evaluated by applying 2017 KIDAS data. Of the 2,629 occupants in the KIDAS database from 2011 to 2016, after applying several exclusion conditions, 459 occupants were used to develop the predictive model. The external validity of the derived predictive model was assessed using the 13 MVC occupants from the 2017 KIDAS database meeting our inclusion criteria. Among the 137 MVC occupants from the 2017 KIDAS database for analysis of the external validity of the derived predictive model, the predictive model was verified for 13 MVC occupants. RESULTS: Logistic regression analysis was used to derive a predictive model based on sex, age, body mass index, type of vehicle, belt status, seating row, crush type, and crush extent. This predictive model had an explanatory power of 65.5% to determine an actual QTF of 0 and 1 (c-statistics: 0.655). As a result of the external validity analysis of the predictive model using data from the 2017 KIDAS database (N = 13), sensitivity, specificity, and accuracy were 0.500, 0.857, and 0.692, respectively. CONCLUSIONS: Using the predictive model, the results of the external validity analysis showed low sensitivity but high specificity. This predictive model provided meaningful results, with a high success rate for determining no injury to an occupant. Given our study results, future research is needed to create a more accurate predictive model that includes relevant technical and sociological factors.

Risk of serious injury of occupants involved in frontal crashes of cab-over-type trucks.

OBJECTIVES: Truck vehicles (TVs) have a different structure and stiffness than non-TVs and are used commercially for transporting goods. This study aimed to analyze whether truck occupants have a greater risk of serious injury than those of other types of vehicles. METHODS: Crash data were obtained from the Korean In-Depth Data Analysis Study (KIDAS) for calendar years 2011-2016. Vehicles involved in frontal crash were included and classified into TVs and non-TVs (passenger cars and sports utility vehicles). We compared the demographic characteristics and serious injuries by body region between the 2 groups and analyzed factors that contributed to the serious injury severity from frontal crashes. RESULTS: The analysis was based on 884 occupants; 177 (20.0%) were in TVs and 707 (80.0%) were in non-TVs. Non-TVs had more frontal airbags deployments than TVs (50.9% vs. 3.4%, P <.01). TV occupants were 4.8 times more likely to have a serious lower extremity (LE) injury (adjusted odds ratio [AOR] = 4.820; 95% confidence interval [CI], 2.407-9.653) and 2.5 times to have a serious abdominal injury (AOR = 2.465; 95% CI, 1.108-5.487) compared to non-TV occupants. CONCLUSIONS: Truck occupants had more serious LE and abdominal injuries than those of other types of vehicles in frontal crashes. Structural improvement and legislative efforts to develop safety systems are necessary to improve the safety of truck occupants.

Considerations for physicians using ketamine for sedation of children in emergency departments.

OBJECTIVE: Ketamine use in emergency departments (EDs) for procedural sedation and analgesia is becoming increasingly common. However, few studies have examined patient factors related to adverse events associated with ketamine. This study investigated factors for consideration when using ketamine to sedate pediatric ED patients. METHODS: The study included pediatric patients receiving ketamine for laceration repair in the ED. Before sedation, information was collected about upper respiratory tract infection symptoms, allergy history, and fasting time. Patients received 2 mg/kg ketamine intravenously or 4 mg/kg ketamine intramuscularly. The primary outcomes were adverse events due to ketamine. RESULTS: We studied 116 patients aged 8 months to 7 years (2.8±1.5 years). The group with adverse events was significantly younger on average than the group without adverse events (2.5±1.5 vs. 3.1±1.5, P=0.028). Upper respiratory tract infection symptoms were not significant variables affecting ketamine sedation (48.9% vs. 43.7%, P=0.719). There was no significant association between duration of fasting and adverse events (P=0.073 and P=0.897, respectively), or between food type and adverse events (P=0.734). However, the number of attempts to sedate and ketamine dose correlated with adverse events (P<0.001 and P=0.022, respectively). In multiple logistic regression analysis, intravenous injection and ketamine dose were significant factors (odds ratio, 16.77; 95% confidence interval, 1.78 to 498.54; odds ratio, 4.37; 95% confidence interval, 1.59 to 22.9, respectively). CONCLUSION: Emergency medicine physicians should consider injection type and ketamine dose when using ketamine sedation while suturing lacerations.

Identifying the optimal hand placement site for chest compression by measuring hand width and sternal length in young adults.

OBJECTIVE: There are no specific guidelines regarding the exact hand placement location for effective chest compressions. This study was designed to identify the optimal hand placement site over the chest during cardiopulmonary resuscitation (CPR). METHODS: The sternal length (SL) of young Korean adults was measured as the distance from the suprasternal notch (SN) to the lower end of the sternum. In addition, the heel width of the hand (H) was measured 1 cm (H1) and 2 cm (H2) distal to the proximal end of the carpal bones. RESULTS: A total of 300 men and 300 women were enrolled. SL positively correlated with height (R(2)=14.2), weight (R(2)=15.3), BMI (R(2)=10.3), H1 (R(2) =3.4), and H2 (R(2) = 5.0). Mean H2 and half of the SL (SL/2) for the subgroups were M 8.4 and 10.1 cm, M' 8.3 and 9.7 cm, W 7.6 and 10.1 cm, and W' 7.4 and 9.5 cm, respectively (M, men taller than the mean; M', men shorter than the mean; W, women taller than the mean; W', women shorter than the mean). Mean H2 in men was 1.1 to 1.6 cm shorter than SL/2, whereas mean H2 in women was 2.2 to 2.9 cm shorter than SL/2. CONCLUSIONS: To find the most optimal chest compression point, from the patients' left side, CPR providers need to palpate the SN using the right little finger and placing the left heel one heel width (H2) from the SN. From the patient's right side, CPR providers should use the left little finger to palpate the SN and place the right heel one heel width (H2) from the SN.

Does hypokalemia contribute to acute kidney injury in chronic laxative abuse?

Prolonged hypokalemia from chronic laxative abuse is recognized as the cause of chronic tubulointerstitial disease, known as "hypokalemic nephropathy," but it is not clear whether it contributes to acute kidney injury (AKI). A 42-year-old woman with a history of chronic kidney disease as a result of chronic laxative abuse from a purging type of anorexia nervosa (AN-P), developed an anuric AKI requiring hemodialysis and a mild AKI 2 months later. Both episodes of AKI involved severe to moderate hypokalemia (1.2 and 2.7 mmol/L, respectively), volume depletion, and mild rhabdomyolysis. The histologic findings of the first AKI revealed the remnants of acute tubular necrosis with advanced chronic tubulointerstitial nephritis and ischemic glomerular injury. Along with these observations, the intertwined relationship among precipitants of recurrent AKI in AN-P is discussed, and then we postulate a contributory role of hypokalemia involved in the pathophysiology of the renal ischemia-induced AKI.

Investigation of nanostructural changes following acute injury using atomic force microscopy in rabbit vocal folds.

There continues to be a paucity of data regarding the nanostructural changes of vocal fold (VF) collagen after injury. The aim of this study is to investigate the nanostructural and morphological changes in the rabbit VF lamina propria following acute injury using atomic force microscopy (AFM). Unilateral VF injury was performed on 9 New Zealand breeder rabbits. Sacrifice and laryngeal harvest were performed at three time points: 1 day, 3 days, and 7 days after injury. Histology and immunohistochemistry data were collected to confirm extracellular matrix (ECM) changes in rabbit VF. The progressive changes in thickness and D-spacing of VF collagen fibrils were investigated over a 7-day postinjury period using AFM. At post-injury day 1, a fibrin clot and inflammatory cell infiltration were observed at the injured VF. The inflammatory score at postinjury day 1 was highest in injured VF tissue, with a significant decrease at postinjury day 7. The immunoreactivity of inflammatory proteins (COX-2, TNF-α) was observed in VF up to day 7 after injury. AFM investigation showed clustered and disorganized collagen fibrils at the nanoscale resolution at post-injury day 7. Collagen fibrils in injured VF at postinjury day 7 were significantly thicker than control and postinjury days 1 and 3 (P < 0.001). D-spacing of collagen at postinjury day 7 was not studied due to loss of distinct edges resulting from immature collagen deposition. AFM investigation of VF could add valuable information to understanding micromechanical changes in VF scar tissue.

Transformation of Ramsey electromagnetically induced absorption into magnetic-field induced transparency in a paraffin-coated Rb vapor cell.

We report on magnetic-field induced transparency (MIT) based on Ramsey electromagnetically induced absorption (EIA) in a paraffin-coated Rb vapor cell. Changing the laser polarization from linear to circular in the presence of a weak residual transverse magnetic field to the laser propagation, the narrow absorption due to the Ramsey EIA transformed into the transparency due to MIT of the 5S1/2 (F = 2)-5P3/2 (F' = 3) transition of 87Rb in the paraffin-coated Rb vapor cell. The spectral widths of the EIA and MIT in the Hanle configuration were measured to be 0.6 mG (425 Hz) and 1.2 mG, respectively. MIT depended on the long preservation time of the ground-state coherent spin states and the transverse magnetic field. From the numerical results, the crossover between the Ramsey EIA and the MIT could be illustrated as the superposition of both signals.

Identification of perirenal or renal splenosis from undetermined masses: case report and review of the literature.

The incidental finding of tumor-llke perirenal or renal splenosis (PRS) creates a challenge to the renal physicians, because its benign nature has to be distinguished from a malignancy. This paper describes the case of a 40-year-old man referred from a local clinic for further evaluation of an incidental finding of left abdominal masses by ultrasonogram suspecting neoplasm, but was eventually confirmed as PRS by obtaining a history of splenectomy that pointed to splenosis and subsequently by a fusion image from single photon emission computed tomography using 99mTc-labelled heat-denatured erythrocytes and computed tomography (hybrid SPECT/CT). In addition, a review of 27 cases of PRS in a MEDLINE search including the present case revealed the following: all the masses were found incidentally and were associated with a history of previous splenectomy or splenic injury; the initial impressions were neoplastic tumor/PRS (n = 9), PRS (n = 10), and neoplastic tumor without consideration of splenosis (n = 8); surgical exploration was undertaken in all the 8 cases of suspected neoplastic tumor only, whereas non-invasive radiological or radionuclide imaging confirmed splenosis in the rest of the cases (n = 19). To avoid unnecessary tests and invasive surgery for undetermined perirenal or renal masses accompanying previous splenic injury, we stress the paramount importance of careful history-taking, physical examination, and a high index of suspicion for splenosis. Also, fusion imaging of hybrid SPECT/CT was reconfirmed as a useful diagnostic technique for accurately detecting and localizing splenic tissues by PRS.