On-Site Deployment of an Air-Liquid-Interphase Device to Assess Health Hazard Potency of Airborne Workplace Contaminants: The Case of 3-D Printers.

Biomonitoring of workers is an approach of evaluating workers' exposure to chemicals and particulate matter by measuring biomarkers of parent chemicals, their metabolites, and reaction products in workers' biospecimens. Prerequisites for biological monitoring in the workplace include permission to enter the workplace, approval of the study plan from the IRB (Institutional Review Board), and obtaining consent from workers. Because of the complex legal process involved in biomonitoring, few studies have been conducted so far on biomonitoring of workers' exposures to nanoparticles and other hazards from emerging materials and advanced nanotechnologies. We have developed a cell-based biomonitoring device that can evaluate acute cytotoxicity and various other effect biomakers, such as inflammation, at realistic workplace exposure. This device is based on air-liquid interphase (ALI) and can be used to evaluate cell toxicity and early effect biomarkers along adverse outcome pathways. Following exposure of A549 lung epithelial cells in ALI to workplace air for 1-2 h, the cells were processed to assess the induction of inflammatory and cell damage biomarkers. Initially, we estimated the deposition rate of nanoparticles in the transwell by exposing the cell-free ALI device to silver nanoparticle aerosols (AgNP 20-30 nm) for 2 h in the laboratory. Then A549 lung epithelial cells cultured on the transwell in the ALI device were exposed to AgNP nanoaerosols for 2 h and evaluated for cytotoxicity and induction of mRNAs of pro-inflammatory cytokines IL-1b, IL-6, and TNF-α. Then the cells in the ALI device were exposed to 3-D printer emissions at the workplace and evaluated for the same matched endpoints. The mRNA levels for IL-1b, IL-6, and TNF-α increased significantly at the end of 2-h exposure of A549 cells to the positive control AgNP aerosols. These mRNAs, as well as LDH and microprotein concentrations, increased even more after 24-h post-exposure incubation (p < 0.05). Cytotoxicity evaluation of 3-D printer emissions at 810 and 957 µg/m3, which was more than 80 times higher than the airborne total suspended particulate concentrations in the workplace air (9-12.5 µg/m3), suggested no significant acute cytotoxicity at the end of 2-h exposure to 3-D-printing emission, as well as at 24-h post-exposure incubation. Hyperspectral microscopic observation showed that 3-D printers emitted particles to be attached to A549 cells after 2-h exposure, and many particles were internalized by A549 cells after 24 h of post-exposure incubation. The mRNA expression of pro-inflammatory cytokine IL-1b and IL-6 increased significantly after 2-h exposure to 3-D printer emissions and after 24-h incubation (only IL-6). In contrast, the expression of TNF-α mRNA decreased significantly after 2 h of exposure to 3-D printers and decreased even more after 24-h post-exposure incubation. These results support the use of cell-based ALI devices for direct assessment of airborne hazards in the workplace, for probing toxicological properties of airborne contaminants using adverse molecular pathways, and for guiding study design for workplace biomonitoring. ALI devices can bridge conventional exposure assessment with cellular toxicity testing platforms for hazard and risk assessment.

Impact of Vitamin B12 Insufficiency on Sarcopenia in Community-Dwelling Older Korean Adults.

Vitamin B12 (B12) is involved as a cofactor in the synthesis of myelin. A lack of B12 impairs peripheral nerve production, which can contribute to sarcopenia. In this cross-sectional study, we aimed to investigate the relationship between B12 insufficiency and sarcopenia in community-dwelling older Korean adults. A total of 2325 (1112 men; 1213 women) adults aged 70-84 years were recruited. The tools used for sarcopenia were based on the Asian Working Group for Sarcopenia (AWGS) guidelines. Individuals with low appendicular skeletal muscle mass index (ASMI) (<7.0 kg/m2 for men; <5.4 kg/m2 for women) and low hand grip strength (HGS) (<28 kg for men; <18 kg for women) were defined as the sarcopenia group. Among this group, those who showed low physical performance (≤9 points on the Short Physical Performance Battery (SPPB)) were defined as the severe sarcopenia group. B12 concentrations were classified into insufficient (<350 pg/mL) and sufficient (≥350 pg/mL). Univariate and multivariate logistic regression analyses were used to evaluate the relationship between sarcopenia and B12 levels. Low ASMI showed a high incidence in the B12-insufficient group. However, HGS, SPPB, and the severity of sarcopenia showed no correlation with B12. Further, insufficient B12 may affect muscle quantity rather than muscle strength or physical performance.

Assessment and Mitigation of Exposure of 3-D Printer Emissions.

This study monitored particulates, and volatile organic compounds (VOCs) emitted from 3-D printers using acrylonitrile-butadiene-styrene copolymer (ABS) filaments at a workplace to assess exposure before and after introducing exposure mitigation measures. Air samples were collected in the printing room and adjacent corridor, and real-time measurements of ultrafine and fine particle were also conducted. Extensive physicochemical characterizations of 3-D printer emissions were performed, including real-time (size distribution, number concentration) nanoparticle characterization, size-fractionated mass distribution and concentration, as well as chemical composition for metals by ICP-MS and VOCs by GC-FID, real-time VOC monitors, and proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS). Air sampling showed low levels of total suspended particulates (TSP, 9-12.5/m3), minimal levels (1.93-4 ppm) of total volatile organic chemicals (TVOC), and formaldehyde (2.5-21.7 ppb). Various harmful gases, such as formaldehyde, acrolein, acetone, hexane, styrene, toluene, and trimethylamine, were detected at concentrations in the 1-100 ppb by PTR-TOF-MS when air sample was collected into the Tedlar bag from the front of the 3-D printer. Ultrafine particles having an average particle size (30 nm count median diameter and 71 nm mass median diameter) increased during the 3-D printing operation. They decreased to the background level after the 3-D printing operation, while fine particles continually increased after the termination of 3-D printing to the next day morning. The exposure to 3-D printer emissions was greatly reduced after isolating 3-D printers in the enclosed space. Particle number concentration measured by real-time particle counters (DMAS and OPC) were greatly reduced after isolating 3-D printers to the isolated place.

Using miniaturised scanning mobility particle sizers to observe size distribution patterns of quasi-ultrafine aerosols inhaled during city commuting.

Portable miniaturised scanning mobility particle sizer (SMPS) instruments measuring atmospheric particles within the 10-241 nm size range were used to track particle number size distributions and concentrations during near-simultaneous pedestrian, bicycle, bus, car, tram and subway commuting journeys in Barcelona, Spain on 4th-6th July 2018. The majority of particles in this size range were <100 nm, with k-means cluster analysis identifying peaks at 15-22 nm, 30-40 nm, and 45-75 nm. Around 10-25% of the particles measured however were >100 nm (especially in the subway environment) and so lie outside the commonly defined range of "ultrafine" particles (UFP, or <100 nm particles). The study demonstrated in detail how personal exposure to quasi-UFP (QUFP, <241 nm), most of which present in the city streets are produced by road traffic, varies greatly depending on the transport mode and route chosen. Proximity to fresh traffic exhaust sources, such as in a car with open windows, on-road cycling, walking downwind of busy roads, or in a subway station contaminated by roadside air, enhances commuter exposure to particles <30 nm in size. In contrast, travelling inside air-conditioned bus or tram offers greater protection to the commuter from high concentrations of fresh exhaust. Ultrafine number size distributions in traffic-contaminated city air typically peak in the size range 30-70 nm, but they can be shifted to finer sizes not only by increased content of fresh proximal exhaust emissions but also by bursts of new particle formation (NPF) events in the city. One such afternoon photochemical nucleation NPF event was identified during our Barcelona study and recognised in different transport modes, including underground in the subway system. The integration of static urban background air monitoring station information with particle number concentration and size distribution data obtained from portable miniaturised SMPS instruments during commuting journeys opens new approaches to investigating city air quality by offering a level of detail not previously available.

Mode of silver clearance following 28-day inhalation exposure to silver nanoparticles determined from lung burden assessment including post-exposure observation periods.

Recently revised OECD inhalation toxicity testing guidelines require measurements of lung burden immediately after and for periods following exposure for nanomaterials. Lung burden is a function of pulmonary deposition and retention of nanoparticles. Using lung burden studies as per OECD guidelines, it may be possible to assess clearance mechanisms of nanoparticles. In this study, male rats were exposed to silver nanoparticle (AgNP) aerosols (18.1-19.6 nm) generated from a spark generator. Exposure groups consisted of (1) control (fresh air), (2) low (31.2 ± 8.5 µg/m3), (3) moderate (81.8 ± 11.4 µg/m3), and (4) high concentrations (115.6 ± 30.5 µg/m3). Rats were exposed for 6-h/day, 5-days/week for 4 weeks (28-days) based on the revised OECD test guideline 412. Bronchoalveolar lavage (BAL) fluids were collected on post-exposure observation (PEO)-1 and PEO-7 days and analyzed for inflammatory cells and inflammatory biomarkers. The lung burdens of Ag from AgNPs were measured on PEO-1, PEO-7, and PEO-28 days to obtain quantitative mass concentrations per lung. Differential counting of blood cells and inflammatory biomarkers in BAL fluid and histopathological evaluation of lung tissue indicated that exposure to the high concentrations of AgNP aerosol induced inflammation at PEO-1, slowly resolved at PEO-7 and completely resolved at PEO-28 days. Lung burden measurement suggested that Ag from AgNPs was cleared through two different modes; fast and slow clearance. The fast clearance component was concentration-dependent with half-times ranging from two to four days and clearance rates of 0.35-0.17/day-1 from low to high concentrations. The slow clearance had half-times of 100, 57, and 76 days and clearance rates of 0.009, 0.012, and 0.007/day-1 for the high, moderate and low concentration exposure. The exact mechanism of clearance is not known currently. The fast clearance component which was concentration-dependent could be dependent on the dissolution of AgNPs and the slow clearance would be due to slow clearance of the low dissolution AgNPs secondary particles originating from silver ions reacting with biogenic anions. These secondary AgNPs might be cleared by mechanisms other than dissolution such as mucociliary escalation, translocation to the lymphatic system or other organs.

28-Day inhalation toxicity study with evaluation of lung deposition and retention of tangled multi-walled carbon nanotubes.

Lung deposition and retention measurements are now required by the newly revised OECD inhalation toxicity testing guidelines 412 and 413 when evaluating the clearance and biopersistence of poorly soluble nanomaterials, such as multi-walled carbon nanotubes (MWCNTs). However, evaluating the lung deposition concentration is challenging with certain nanomaterials, such as carbon-based and iron-based nanomaterials, as it is difficult to differentiate them from endogenous elements. Therefore, the current 28-day inhalation toxicity study investigated the lung retention kinetics of tangled MWCNTs. Male Sprague Dawley rats were exposed to MWCNTs at 0, 0.257, 1.439, and 4.253 mg/m3 for 28 days (6 h/day, 5 days/week, 4 weeks). Thereafter, the rats were sacrificed at day 1, 7, and 28 post-exposure and the pulmonary inflammatory response evaluated by analyzing the bronchoalveolar lavage fluid. Plus, the blood biochemistry, hematology, and histopathology of the lungs were also examined. The lung deposition and retention of MWCNTs were determined based on the elemental carbon content in the lungs after tissue digestion. The number of polymorphonuclear cells and LDH concentration were both found to be significantly higher with the medium and high concentrations (1.439 and 4.253 mg/m3) and dose dependent. The estimated retention half-life for the high concentration (4.253 mg/m3) was about 35 days. The results of this study indicate that tangled MWCNTs seem to have a relatively shorter retention half-life when compared to previous reports on rigid MWCNTs, and the no-observed adverse effect level (NOAEL) for the tested tangled MWCNTs was 0.257 mg/m3 in a previous rat 28-day subacute inhalation toxicity study.

Correlations between swallowing function and acoustic vowel space in stroke patients with dysarthria.

BACKGROUND: Dysphagia and dysarthria tend to coexist in stroke patients. Dysphagia can reduce patients' quality of life, cause aspiration pneumonia and increased mortality. OBJECTIVE: To evaluate correlations among swallowing function parameters and acoustic vowel space values in patients with stroke. METHODS: Data from stroke patients with dysarthria and dysphagia were collected. The formant parameter representing the resonance frequency of the vocal tract as a two-dimensional coordinate point was measured for the /a/, /ae/, /i/, and /u/vowels, and the quadrilateral vowel space area (VSA) and formant centralization ratio (FCR) were measured. Swallowing function was evaluated by a videofluoroscopic swallowing study (VFSS) using the videofluoroscopic dysphagia scale (VDS) and penetration aspiration scale (PAS). Pearson's correlation and linear regression analyses were used to assess the correlation of VSA and FCR to VDS and PAS scores. RESULTS: Thirty-one stroke patients with dysphagia and dysarthria were analyzed. VSA showed a negative correlation to VDS and PAS scores, while FCR showed a positive correlation to VDS score, but not to PAS score. VSA and FCR were significant factors for assessing dysphagia severity. CONCLUSIONS: VSA and FCR values were correlated with swallowing function and may be helpful in predicting dysphagia severity associated with stroke.

Clinical and Radiological Evaluation After Chemical Synovectomy With Rifampicin in Hemophilic Arthropathy: Korean Experience With a 2-Week Interval Protocol.

OBJECTIVE: To assess the clinical outcome of chemical synovectomy with rifampicin in hemophilic arthropathy by using the World Federation of Hemophilia (WFH) scoring system and plain radiograph. METHODS: We performed rifampicin synovectomy (RS) on 30 joints of 28 hemophilic patients diagnosed as hemophilic arthropathy stage I-III (based on Fernandez-Palazzi clinical classification). Clinical status (bleeding frequency, pain, joint physical status) and radiological staging were evaluated as parts of the WFH scoring system before and 1 year after RS. The patients were divided into two groups by the Arnold-Hilgartner scale of the initial X-ray as stage 3 or less for the low-stage group (n=17) and over 3 for the high-stage group (n=13). RESULTS: Total WFH joint physical scores were reduced after injection, and the number of bleeding episodes and pain showed especially significant improvement. For other subscores of the WFH joint physical score, only swelling, range of motion, and crepitus showed statistically significant improvement. According to the severity of the radiologic finding, the WFH joint physical score of both the low-stage and high-stage groups showed significant improvement. In the radiological aspect, the low-stage group, without joint space narrowing at the initial plain radiograph, showed no further aggravation after injection. However, in the high-stage group, radiology found aggravation regardless of the procedure. CONCLUSION: It is suggested that chemical synovectomy with rifampicin may prevent hemarthrosis and improve clinical symptoms. Especially in the early stage of arthropathy without joint-space narrowing, it seems to have an additional benefit that delays radiological aggravation and preserves joint status.

Association Between Asymmetry in Knee Extension Strength and Balance in a Community-Dwelling Elderly Population: A Cross-Sectional Analysis.

OBJECTIVE: To evaluate the association between balance function and asymmetry of knee extension strength in an elderly Korean population. METHODS: The strength of the knee extensors in each leg was measured in 306 community-dwelling elderly subjects (age, 76.70±4.85 years) and 25 young healthy subjects (age, 34.23±8.93 years). Based on the difference in strength of both legs, the elderly subjects were divided into symmetric (n=128) and asymmetric (n=178) strength groups using an asymmetry cutoff 20%. We determined the postural control ability of the subjects using InBody posturography, Berg Balance Scale (BBS), Timed Up and Go test (TUG) and Short Physical Performance Battery (SPPB). The sway index (SI) of the subjects in four positions was assessed using posturography. RESULTS: The group with asymmetric strength presented a significantly higher SI than the group with symmetric strength, in the normal position with eyes open and eyes open on pillows. In the normal position with the eyes closed and in postures with the eyes closed on pillows, the statistical analysis revealed no significant differences between the two groups. The three tests for physical performance (BBS, TUG, and SPPB) show no statistically significant difference between the two groups. CONCLUSION: The asymmetric strength group showed a significantly lower balance than the group with symmetric strength based on several posturographic parameters. Ambulatory elderly individuals with asymmetry in knee extension strength, showed deficits in balance control even in normal clinical tests.

Asymmetric Atrophy of Paraspinal Muscles in Patients With Chronic Unilateral Lumbar Radiculopathy.

OBJECTIVE: To assess the cross-sectional area (CSA) of the muscles for investigating the occurrence of asymmetry of the paraspinal (multifidus and erector spinae) and psoas muscles and its relation to the chronicity of unilateral lumbar radiculopathy using magnetic resonance imaging (MRI). METHODS: This retrospective study was conducted between January 2012 to December 2014. Sixty one patients with unilateral L5 radiculopathy were enrolled: 30 patients had a symptom duration less than 3 months (group A) and 31 patients had a symptom duration of 3 months or more (group B). Axial MRI measured the CSA of the paraspinal and psoas muscles at the middle between the lower margin of the upper vertebra and upper margin of the lower vertebra, and obtained the relative CSA (rCSA) which is the ratio of the CSA of muscles to that of the lower margin of L4 vertebra. RESULTS: There were no differences in the demographics between the two groups. In group B, rCSA of the erector spinae at the L4-5 level, and that of multifidus at the L4-5 and L5-S1 levels, were significantly smaller on the involved side as compared with the uninvolved side. In contrast, no significant muscle asymmetry was observed in group A. The rCSA of the psoas was not affected in either group. CONCLUSION: The atrophy of the multifidus and erector spinae ipsilateral to the lumbar radiculopathy was observed only in patients suffering from unilateral radiculopathy for 3 months or more.

Association Between a Polymorphism in CASP3 and CASP9 Genes and Ischemic Stroke.

OBJECTIVE: To investigate whether the polymorphisms of CASP3 gene (rs4647602, intron A/C and rs1049216, UTR C/T) and CASP9 gene (rs1052576, Gln/Arg G/A and rs1052571, Ser/Val T/C) were associated with the development, and clinical severity of ischemic stroke and functional consequences after stroke. METHODS: Genomic DNA from 121 ischemic stroke patients and 201 healthy control subjects were extracted, and polymerase chain reaction products were sequenced. To investigate the association of polymorphisms and the development, and National Institutes of Health Stroke Scale (K-NIHSS), logistic regression models were analyzed. RESULTS: Polymorphism of the untranslational region of CASP3 (rs1049216, UTR C/T) has been associated with the development of ischemic stroke-in codominant1 model (odds ratio [OR], 0.51; 95% confidence interval [CI], 0.29-0.88; p=0.017), in dominant model (OR, 0.57; 95% CI, 0.34-0.97; p=0.034), and in the overdominant model (OR, 0.50; 95% CI, 0.29-0.87; p=0.011). A missense SNP of CASP9 gene (rs1052571, Ser/Val T/C) was associated with the development of ischemic stroke (OR, 1.93; 95% CI, 1.05-3.55; p=0.034 in recessive model). CONCLUSION: These results indicate the possibility that CASP3 and CASP9 genes are markers for the development of ischemic stroke.

The Association Between Fall History and Physical Performance Tests in the Community-Dwelling Elderly: A Cross-Sectional Analysis.

OBJECTIVE: To evaluate the association between baseline characteristics, three physical performance tests and fall history in a sample of the elderly from Korean population. METHODS: A total of 307 participants (mean age, 76.70±4.85 years) were categorized into one of two groups, i.e., fallers and non-fallers. Fifty-two participants who had reported falling unexpectedly at least once in the previous 12 months were assigned to the fallers group. Physical performance tests included Short Physical Performance Battery (SPPB), Berg Balance Scale (BBS), Timed Up and Go test. The differences between the two study groups were compared and we analyzed the correlations between fall histories and physical performance tests. RESULTS: SPPB demonstrated a significant association with fall history. Although the BBS total scores did not show statistical significance, two dynamic balance test items of BBS (B12 and B13) showed a significant association among fallers. CONCLUSION: This study suggests that SPPB and two dynamic balance test items of the BBS can be used in screening for risk of falls in an ambulatory elderly population.

Biomechanical Parameters in Plantar Fasciitis Measured by Gait Analysis System With Pressure Sensor.

OBJECTIVE: To investigate the differences in biomechanical parameters measured by gait analysis systems between healthy subjects and subjects with plantar fasciitis (PF), and to compare biomechanical parameters between 'normal, barefooted' gait and arch building gait in the participants. METHODS: The researchers evaluated 15 subjects (30 feet) with bilateral foot pain and 15 subjects (15 feet) with unilateral foot pain who had a clinical diagnosis of PF. Additionally, 17 subjects (34 feet) who had no heel pain were recruited. Subjects were excluded if they had a traumatic event, prior surgery or fractures of the lower limbs, a leg length discrepancy of 1 cm or greater, a body mass index greater than 35 kg/m2, or had musculoskeletal disorders. The participants were asked to walk with an arch building gait on a treadmill at 2.3 km/hr for 5 minutes. Various gait parameters were measured. RESULTS: With the arch building gait, the PF group proved that gait line length and single support line were significantly decreased, and lateral symmetry of the PF group was increased compared to that of the control group. The subjects with bilateral PF displayed significantly increased maximum pressure over the heel and the forefoot during arch building gait. In addition, the subjects with unilateral PF showed significantly increased maximum pressure over the forefoot with arch building gait. CONCLUSION: The researchers show that various biomechanical differences exist between healthy subjects and those with PF. Employing an arch building gait in patients with PF could be helpful in changing gait patterns to normal biomechanics.

The Relationship Between Tongue Pressure and Oral Dysphagia in Stroke Patients.

OBJECTIVE: To evaluate the relationships between tongue pressure and different aspects of the oral-phase swallowing function. METHODS: We included 96 stroke patients with dysphagia, ranging in age from 40 to 88 years (mean, 63.7 years). Measurements of tongue pressure were obtained with the Iowa Oral Performance Instrument, a device with established normative data. Three trials of maximum performance were performed for lip closure pressure (LP), anterior hard palate-to-tongue pressure (AP), and posterior hard palate-to-tongue pressure (PP); buccal-to-tongue pressures on both sides were also recorded (buccal-to-tongue pressure, on the weak side [BW]; buccal-to-tongue pressure, on the healthy side [BH]). The average pressure in each result was compared between the groups. Clinical evaluation of the swallowing function was performed with a videofluoroscopic swallowing study. RESULTS: The average maximum AP and PP values in the intact LC group were significantly higher than those in the inadequate lip closure group (AP, p=0.003; PP, p<0.001). AP and PP showed significant relationships with bolus formation (BF), mastication, premature bolus loss (PBL), tongue to palate contact (TP), and oral transit time (OTT). Furthermore, LP, BW, and BH values were significantly higher in the groups with intact mastication, without PBL and intact TP. CONCLUSION: These findings indicate that the tongue pressure appears to be closely related to the oral-phase swallowing function in post-stroke patients, especially BF, mastication, PBL, TP and OTT.

Association Between a Polymorphism (rs2071214) in Baculoviral IAP Repeat Containing 5 Gene (BIRC5) and Ischemic Stroke in Korean Population.

OBJECTIVE: To investigate whether baculoviral inhibitor of apoptosis (IAP) repeat containing 5 gene (BIRC5) polymorphisms are associated with the development and clinical phenotypes of ischemic stroke in Korea population. METHODS: We enrolled 121 ischemic stroke patients and 291 control subjects. Ischemic stroke patients were divided into subgroups according to the scores of National Institutes of Health Stroke Survey (<6 or ≥6) and Modified Barthel Index (<60 or ≥60). Single nucleotide polymorphisms (SNPs) of BIRC5 (rs3764383 and rs2071214) were selected and genotyped by direct sequencing for all subjects. Multiple logistic regression models (codominant 1 and 2, dominant, recessive, overdominant and log-additive) were used to estimate odds ratios (ORs), 95% confidence intervals (CIs), and p-values. RESULTS: In analysis of stroke susceptibility, the genotype and allele frequencies of rs3764383 exhibited no difference between the control group and the ischemic stroke group. SNP rs2071214 was associated with ischemic stroke in the codominant (p=0.003), dominant (p=0.002), overdominant (p=0.005), and log-additive (p=0.008) models, respectively. The G allele frequency of rs2071214 was significantly (p=0.009) associated with susceptibility for ischemic stroke (OR, 1.57; 95% CI, 1.12-2.21). However, in the analysis for clinical phenotype, no SNP of the BIRC5 gene was found to be associated with ischemic stroke. CONCLUSION: These results suggest that a missense SNP (rs2071214) of BIRC5 may be associated with the development of ischemic stroke in the Korean population.

Interleukin-6 Receptor Polymorphisms Contribute to the Neurological Status of Korean Patients with Ischemic Stroke.

To investigate the contribution of the interleukin-6 receptor (IL-6R) gene single nucleotide polymorphisms (SNPs) to the neurological status of Korean patients with ischemic stroke (IS), two SNPs of the IL-6R gene (rs4845617, 5 UTR; rs2228144, Ala31Ala) were selected. IS patients were classified into clinical phenotypes according to two well-defined scores: the National Institutes of Health Stroke Survey (NIHSS) and the Modified Barthel Index scores. There were 121 IS patients and 291 control subjects. The SNP rs4845617 significantly contributed to the neurological status of patients with IS (P = 0.011 in codominant model 2, P = 0.006 in recessive model, and P = 0.008 in log-additive model). Allele frequencies of rs4845617 and rs2228144 demonstrated no significant difference in IS patients and controls. The AG and GG haplotypes differed between the NIHSS 1 (NIHSS scores < 6) group and the NIHSS 2 (NIHSS scores ≥ 6) group in patients with IS (P = 0.014, P = 0.0024). These results suggest that rs4845617 of the IL-6R gene is associated with the neurologic status of Korean patients with IS.

Polymorphism of Nitric Oxide Synthase 1 Affects the Clinical Phenotypes of Ischemic Stroke in Korean Population.

OBJECTIVE: To investigate whether four single nucleotide polymorphisms (SNPs) rs2293054 [Ile734Ile], rs1047735 [His902His], rs2293044 [Val1353Val], rs2682826 (3'UTR) of nitric oxide synthase 1 (NOS1) are associated with the development and clinical phenotypes of ischemic stroke. METHODS: We enrolled 120 ischemic stroke patients and 314 control subjects. Ischemic stroke patients were divided into subgroups according to the scores of the National Institutes of Health Stroke Survey (NIHSS, <6 and ≥6) and Modified Barthel Index (MBI, <60 and ≥60). SNPStats, SNPAnalyzer, and HelixTree programs were used to calculate odds ratios (ORs), 95% confidence intervals (CIs), and p-values. Multiple logistic regression models were performed to analyze genetic data. RESULTS: No SNPs of the NOS1 gene were found to be associated with ischemic stroke. However, in an analysis of clinical phenotypes, we found that rs2293054 was associated with the NIHSS scores of ischemic stroke patients in codominant (p=0.019), dominant (p=0.007), overdominant (p=0.033), and log-additive (p=0.0048) models. Also, rs2682826 revealed a significant association in the recessive model (p=0.034). In allele frequency analysis, we also found that the T alleles of rs2293054 were associated with lower NIHSS scores (p=0.007). Respectively, rs2293054 had a significant association in the MBI scores of ischemic stroke in codominant (p=0.038), dominant (p=0.031), overdominant (p=0.045), and log-additive (p=0.04) models. CONCLUSION: These results suggest that NOS1 may be related to the clinical phenotypes of ischemic stroke in Korean population.

A Patient With Focal Dystonia That Occurred Secondary to a Peripheral Neurogenic Tumor: A Case Report.

Dystonia is a movement disorder characterized by involuntary muscle contractions. Patients with dystonia may experience uncontrollable twisting, repetitive movements, or abnormal posture. A 55-year-old man presented with an involuntary left forearm supination, which he had experienced for five years. There was no history of antecedent trauma to the wrist or elbow. Although conventional therapeutic modalities had been performed, the symptoms persisted. When he visited our hospital, electromyography was performed. Reduced conduction velocity was evident at the elbow-axilla segment of the left median nerve. We suspected that there was a problem on the median nerve between the elbow and the axilla. For this reason, we performed an ultrasonography and magnetic resonance imaging study. A spindle-shaped soft tissue mass was observed at the left median nerve that suggested the possibility of neurofibroma. Dystonia caused by traumatic or compressive peripheral nerve injury has often been reported, but focal dystonia due to a neurogenic tumor is extremely rare. Here, we report our case with a review of the literature.

Monomelic amyotrophy (hirayama disease) with upper motor neuron signs: a case report.

Monomelic amyotrophy (MMA), also known as Hirayama disease, is a sporadic juvenile muscular atrophy in the distal upper extremities. This disorder rarely involves proximal upper extremities and presents minimal sensory symptoms with no upper motor neuron (UMN) signs. It is caused by anterior displacement of the posterior dural sac and compression of the cervical cord during neck flexion. An 18-year-old boy visited our clinic with a 5-year history of left upper extremity pain and slowly progressive weakness affecting the left shoulder. Atrophy was present in the left supraspinatus and infraspinatus. On neurological examination, positive UMN signs were evident in both upper and lower extremities. Electrodiagnostic study showed root lesion involving the fifth to seventh cervical segment of the cord with chronic and ongoing denervation in the fifth and sixth cervical segment innervated muscles. Cervical magnetic resonance imaging (MRI) showed asymmetric cord atrophy apparent in the left side and intramedullary high signal intensity along the fourth to sixth cervical vertebral levels. With neck flexion, cervical MRI revealed anterior displacement of posterior dural sac, which results in the cord compression of those segments. The mechanisms of myelopathy in our patient seem to be same as that of MMA. We report a MMA patient involving proximal limb with UMN signs in biomechanical concerns and discuss clinical importance of cervical MRI with neck flexion. The case highlights that clinical variation might cause misdiagnosis.