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Objective@#This study enrolls diverse hospitals and analyzes the differences in meal provision and nutrition management services for patients with dysphagia. @*Methods@#A nationwide survey was conducted by mail and mobile for 850 medical institutions, and data were collected from 217 hospitals. We analyzed the status of the dysphagia diet and nutrition management by considering the type of hospital. @*Results@#Among the hospitals surveyed, 167 (77%) provided texture-modified diets for dysphagia patients. The status of providing dysphagia diets and nutrition management for dysphagia differed depending on the institution. In particular, nutrition services for dysphagia patients in long-term care hospitals were poor. Difficulties in providing a dysphagia diet included the complexity of the cooking process, difficulty maintaining constant viscosity, difficulty in hygiene management, and low meal bills. Using commercial thickeners in cooking accounted for 72.5%, and only 41.9% of hospitals provided a commercial thickener with meals. Compared to the regular diet, the additional food cost to provide a single dysphagia diet meal was estimated to be 500-1,000 won. Based on a 5-point scale, we determined that the average scores for the importance and performance of nutrition management in patients with dysphagia were 4.29 and 3.19 points, respectively. Regardless of the type of hospital, performances of all the steps in the nutrition care process were significantly lower than their importance. @*Conclusion@#Several difficulties are encountered in meal provision and nutrition management for patients with dysphagia, including the burden of expenses and human resources. Thus, the medical fees for a dysphagia diet need to be reasonably increased. Moreover, national health insurance should additionally cover nutrition education for dysphagia patients.
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Objective@#To explore the effects of tactile stimulation using air pressure at the auricular branch of the vagus nerve on autonomic activity in healthy individuals. @*Methods@#Three types of tactile stimulation were used in this study: continuous low-amplitude, continuous high-amplitude, and pulsed airflow. The tactile stimulations were provided to the cymba concha to investigate autonomic activity in 22 healthy participants. The mean heart rate (HR) and parameters of HR variability, including the standard deviation of R-R intervals (SDNN) and root mean square of successive R-R interval differences (RMSSD) were compared at baseline, stimulation, and recovery periods. @*Results@#Two-way repeated measures ANOVA indicated a significant main effect of time on HR (p=0.001), SDNN (p=0.003), and RMSSD (p<0.001). These parameters showed significant differences between baseline and stimulation periods and baseline and recovery periods in the post-hoc analyses. There were no significant differences in the changes induced by stimulation type and the interaction between time and stimulation type for all parameters. One-way repeated measures ANOVA showed that HR, SDNN, and RMSSD did not differ significantly among the three time periods during sham stimulation. @*Conclusion@#Parasympathetic activity can be enhanced by auricular tactile stimulation using air pressure, targeting the cymba concha. Further studies are warranted to investigate the optimal stimulation parameters for potential clinical significance.
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Objective@#Dysphagia is a common clinical condition characterized by difficulty in swallowing. It is sub-classified into oropharyngeal dysphagia, which refers to problems in the mouth and pharynx, and esophageal dysphagia, which refers to problems in the esophageal body and esophagogastric junction. Dysphagia can have a significant negative impact one’s physical health and quality of life as its severity increases. Therefore, proper assessment and management of dysphagia are critical for improving swallowing function and preventing complications. Thus a guideline was developed to provide evidence-based recommendations for assessment and management in patients with dysphagia. @*Methods@#Nineteen key questions on dysphagia were developed. These questions dealt with various aspects of problems related to dysphagia, including assessment, management, and complications. A literature search for relevant articles was conducted using Pubmed, Embase, the Cochrane Library, and one domestic database of KoreaMed, until April 2021. The level of evidence and recommendation grade were established according to the Grading of Recommendation Assessment, Development and Evaluation methodology. @*Results@#Early screening and assessment of videofluoroscopic swallowing were recommended for assessing the presence of dysphagia. Therapeutic methods, such as tongue and pharyngeal muscle strengthening exercises and neuromuscular electrical stimulation with swallowing therapy, were effective in improving swallowing function and quality of life in patients with dysphagia. Nutritional intervention and an oral care program were also recommended. @*Conclusion@#This guideline presents recommendations for the assessment and management of patients with oropharyngeal dysphagia, including rehabilitative strategies.
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Background@#Advances in neuroscience and neurotechnology provide great benefits to humans though unknown challenges may arise. We should address these challenges using new standards as well as existing ones. Novel standards should include ethical, legal, and social aspects which would be appropriate for advancing neuroscience and technology.Therefore, the Korea Neuroethics Guidelines were developed by stakeholders related to neuroscience and neurotechnology, including experts, policy makers, and the public in the Republic of Korea.Method: The guidelines were drafted by neuroethics experts, were disclosed at a public hearing, and were subsequently revised by opinions of various stakeholders. @*Results@#The guidelines are composed of twelve issues; humanity or human dignity, individual personality and identity, social justice, safety, sociocultural prejudice and public communication, misuse of technology, responsibility for the use of neuroscience and technology, specificity according to the purpose of using neurotechnology, autonomy, privacy and personal information, research, and enhancement. @*Conclusion@#Although the guidelines may require a more detailed discussion after future advances in neuroscience and technology or changes in socio-cultural milieu, the development of the Korea Neuroethics Guidelines is a milestone for the scientific community and society in general for the ongoing development in neuroscience and neurotechnology.
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Objective@#To investigate the clinical and swallowing characteristics related to respiratory infection in patients with parkinsonism. @*Methods@#One hundred and forty-two patients with parkinsonism who underwent videofluoroscopic swallowing studies (VFSS) were enrolled in this study. The initial clinical and VFSS characteristics were compared between patients with and without a history of respiratory infection in the past year. A multivariate logistic regression model was applied to identify clinical and swallowing characteristics related to respiratory infections. @*Results@#Patients with respiratory infections were older (74.75±10.20 years vs. 70.70±8.83 years, p=0.037), had a higher Hoehn and Yahr (H&Y) stage (stage IV–V, 67.9% vs. 49.1%; p=0.047), and were more likely to have a diagnosis of idiopathic Parkinson’s disease (IPD) (67.9% vs. 41.2%, p=0.011) than those without respiratory infections. Among VFSS findings, bolus formation, premature bolus loss, oral transit time, pyriform sinus residues, pharyngeal wall coatings, and penetration/aspiration were significantly worse in patients with respiratory infections (p<0.05). Regarding clinical characteristics, higher H&Y stage (odds ratio [OR], 3.174; 95% confidence interval [CI], 1.226–8.216; p=0.017) and diagnosis of IPD (OR, 0.280, 95% CI, 0.111–0.706; p=0.007) were significantly related to respiratory infections in the multivariate analysis. Among VFSS findings, pyriform sinus residue (OR, 14.615; 95% CI, 2.257–94.623; p=0.005) and premature bolus loss (OR, 5.151; 95% CI, 1.047–25.338; p=0.044) were also significantly associated with respiratory infection. @*Conclusion@#This study suggests that disease severity, diagnosis, pyriform sinus residue, and premature bolus loss observed in VFSS are associated with respiratory infection in patients with parkinsonism.
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Objective@#This study aimed to explore the myelin volume change in patients with mild traumatic brain injury (mTBI) with post-concussion syndrome (PCS) using a multidynamic multiecho (MDME) sequence and automatic whole-brain segmentation. @*Materials and Methods@#Forty-one consecutive mTBI patients with PCS and 29 controls, who had undergone MRI including the MDME sequence between October 2016 and April 2018, were included. Myelin volume fraction (MVF) maps were derived from the MDME sequence. After three dimensional T1-based brain segmentation, the average MVF was analyzed at the bilateral cerebral white matter (WM), bilateral cerebral gray matter (GM), corpus callosum, and brainstem. The Mann–Whitney U-test was performed to compare MVF and myelin volume between patients with mTBI and controls. Myelin volume was correlated with neuropsychological test scores using the Spearman rank correlation test. @*Results@#The average MVF at the bilateral cerebral WM was lower in mTBI patients with PCS (median [interquartile range], 25.2% [22.6%–26.4%]) than that in controls (26.8% [25.6%–27.8%]) (p = 0.004). The region-of-interest myelin volume was lower in mTBI patients with PCS than that in controls at the corpus callosum (1.87 cm3 [1.70–2.05 cm3 ] vs. 2.21 cm3 [1.86– 3.46 cm3 ]; p = 0.003) and brainstem (9.98 cm3 [9.45–11.00 cm3 ] vs. 11.05 cm3 [10.10–11.53 cm3 ]; p = 0.015). The total myelin volume was lower in mTBI patients with PCS than that in controls at the corpus callosum (0.45 cm3 [0.39–0.48 cm3 ] vs. 0.48 cm3 [0.45–0.54 cm3 ]; p = 0.004) and brainstem (1.45 cm3 [1.28–1.59 cm3 ] vs. 1.54 cm3 [1.42–1.67 cm3 ]; p = 0.042). No significant correlation was observed between myelin volume parameters and neuropsychological test scores, except for the total myelin volume at the bilateral cerebral WM and verbal learning test (delayed recall) (r = 0.425; p = 0.048). @*Conclusion@#MVF quantified from the MDME sequence was decreased at the bilateral cerebral WM in mTBI patients with PCS. The total myelin volumes at the corpus callosum and brainstem were decreased in mTBI patients with PCS due to atrophic changes.
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These cases imply that the videofluoroscopic AP view helps the evaluation of the vocal fold movement in patients with vocal fold paralysis on laryngoscopy.
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Repetitive transcranial magnetic stimulation (rTMS) is gaining popularity as a research tool in neuroscience; however, little is known about its molecular mechanisms of action. The present study aimed to investigate the rTMS-induced transcriptomic changes; we performed microarray messenger RNA, micro RNA, and integrated analyses to explore these molecular events. Eight adult male Sprague-Dawley rats were subjected to a single session of unilateral rTMS at 1 Hz (n = 4) or sham (n = 4). The left hemisphere was stimulated for 20 minutes. To evaluate the cumulative effect of rTMS, eight additional rats were assigned to the 1-Hz (n = 4) or sham (n = 4) rTMS groups. The left hemisphere was stimulated for 5 consecutive days using the same protocol. Microarray analysis revealed differentially expressed genes in the rat cortex after rTMS treatment. The overrepresented gene ontology categories included the positive regulation of axon extension, axonogenesis, intracellular transport, and synaptic plasticity after repeated sessions of rTMS. A single session of rTMS primarily induced changes in the early genes, and several miRNAs were significantly related to the mRNAs.Future studies are required to validate the functional significance of selected genes and refine the therapeutic use of rTMS.
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Background@#Previous studies have reported an association between pneumonia risk and the use of certain drugs. We investigated the relationship between antihypertensive drugs and pneumonia in the general population. @*Methods@#This case-crossover study utilized the nationwide data of South Korea. We included participants who were hospitalized for pneumonia. A single case period was defined as 30 days before pneumonia onset, and two control periods were established (90–120 and 150–180 days before pneumonia onset). Further, we performed sensitivity and subgroup analyses (according to the presence of diabetes, documented disability, and whether participants were aged ≥ 70 years). We used conditional logistic regression models adjusted for covariates, such as angiotensin-converting-enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), other antihypertensives, statins, antipsychotics, benzodiazepine, and the number of outpatient visits. @*Results@#In total, 15,463 subjects were included in this study. ACE inhibitors (adjusted odds ratio [aOR], 0.660; 95% confidence interval [CI], 0.558–0.781), ARBs (aOR, 0.702; 95% CI, 0.640–0.770), and other antihypertensive drugs (aOR, 0.737; 95% CI, 0.665–0.816) were significantly associated with reduced pneumonia risk. Subgroup analyses according to the presence of diabetes mellitus, documented disability, and whether participants were aged ≥ 70 years consistently showed the association of antihypertensives with a reduced risk of hospitalization for pneumonia. @*Conclusion@#All antihypertensive drug types were related to a lower risk of hospitalization for pneumonia in the general population. Our results implied that frequent medical service usage and protective immunity were primarily related to a reduced risk of pneumonia in the general population of South Korea.
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Background@#We aimed to examine the association between antihypertensive use and the incidence of hospitalized pneumonia in patients with a history of stroke. @*Methods@#In this case-crossover study, we obtained data from the Korean National Health Insurance Service–National Sample Cohort database. We included the data of patients with history of stroke who were admitted with a disease code of pneumonia. We analyzed the patients’ exposure to antihypertensives in the 30 (single case period), 90–120, and 150–180 days (2 control periods) before the onset of pneumonia using conditional logistic regression analysis. Additionally, sensitivity analysis and subgroup analysis according to diabetes status, age, and documented disability were performed. @*Results@#Angiotensin II receptor blocker (ARB) use was associated with a reduced risk of hospitalized pneumonia (adjusted odds ratio [OR] [95% confidence interval; 95% CI]: 0.718 [0.576–0.894]). However, the use of angiotensin converting enzyme inhibitors and other antihypertensives were not associated with a change in hospitalized pneumonia incidence (adjusted OR [95% CI]: 0.902, [0.603–1.350] and 0.788 [0609–1.018], respectively). Subgroup analysis revealed that ARB use was associated with a reduced incidence of hospitalized pneumonia in patients with a history of stroke who were older than 65 years, but not in younger (≤ 65 years) group (adjusted OR [95% CI]: 0.687 [0.536–0.880]). @*Conclusion@#ARB use is associated with a reduced incidence of hospitalized pneumonia in patients with a history of stroke, especially in older adults.
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Objective@#To develop a set of reference standards for tibial motor, common peroneal motor, sural sensory, and superficial peroneal sensory nerve conduction studies (NCSs) with expanded uncertainty in a healthy Korean population. @*Methods@#Standardized procedures were conducted for individual lower extremity NCSs of 199 healthy participants in their 20s (n=100) and 50s (n=99). Mean values and expanded uncertainties for parameters were analyzed with thorough consideration of multiple uncertainty factors under the International Guide to the Expression of Uncertainty in Measurement. In addition, side-to-side differences in onset latency, amplitude, and nerve conduction velocity (NCV) were analyzed. @*Results@#Mean (reference range) for distal onset latency, baseline to negative peak amplitude, NCV of tibial motor nerve in males in their 20s were 4.3 ms (3.1–5.4 ms), 7.1 mV (3.4–10.9 mV), and 50.7 m/s (42.2–59.3 m/s), respectively; sural sensory nerve baseline to negative peak amplitude in males in their 20s was 21.7 μV (8.3–35.2 μV). Including the aforementioned data, we present a vast dataset of normative mean values and expanded uncertainties for NCSs of the leg in a healthy Korean population. Furthermore, upper limits for normal side-to-side differences for onset latency, amplitude, and NCV of each nerve are suggested. @*Conclusion@#To our knowledge, this is the first study to present the reference standards of leg NCSs with consideration for multifactorial uncertainties in an Asian population. We expect these results to help practitioners make reliable and reproducible clinical decisions.
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Acquired brain injury (ABI) is a leading cause of serious long-term disability resulting in substantial economic costs for post-ABI care. This study was conducted to estimate the socioeconomic burden of persons with ABI in Korea. We used a prevalence-based approach and societal perspective to estimate the direct medical, non-medical costs and indirect costs of ABI, including stroke, traumatic brain injury (TBI), and non-traumatic ABI (anoxia, brain tumor, encephalitis, meningitis, hydrocephalus, and other brain disorders) from 2015 to 2017. The study population included patients with ABI over 20 years of age and analyzed according to insurance types encompassing National Health Insurance and automobile insurance. The socioeconomic burden of ABI was 4.67, 5.18, and 5.73 trillion KRW (approximately 4,162, 4,612, and 5,106 million USD) from 2015 to 2017 and around 0.3% of Korea's GDP annually. Estimating by disease, the socioeconomic cost was 72.4% for stroke, 18.6% for TBI, and 9.0% for non-traumatic ABI. Calculated by cost component, medical costs and non-medical costs showed a slight increase every year. Through this study, establishment of rehabilitation systems maximizing the health and quality of life for injured persons remain the key public health strategy for ABI to reduce socioeconomic burden and financial policies to support patients should be needed.
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This study aimed to estimate the trend of traumatic brain injuries (TBIs) and TBI-related medical usage in Korea. Patients first diagnosed with disease codes of TBIs were included.We calculated the crude incidence and age-adjusted incidence, as well as medical cost, length of stay (LOS), clinic visits, and the number of specialized rehabilitation therapy for 1 year. Patients first diagnosed as TBI was higher in national health insurance (NHI) than in automobile insurance (AUTO-I). In contrast with the gradual decrease of the crude incidence, total medical costs both in NH-I and AUTO-I were generally and steadily increased. For oriental medicine, total medical costs dramatically increased in both inpatient and outpatient. LOS, clinic visits, and the number of specialized rehabilitation therapy were higher in AUTO-I than in NH-I. The most frequent age groups in NH-I were the young (0–9) and old (70 or over), whereas in AUTO-I, the working age group was prominent. Our results show differences in the incidence of TBI and medical usage between NH-I and AUTO-I, which could be associated with the policy for strengthening health insurance coverage, automobile-related regulations to prevent accidents and injuries, as well as rapid changes in the structure of the population in Korea.
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Objective@#To evaluate the reliability of suprahyoid and infrahyoid electromyography (EMG) measurement during swallowing. @*Methods@#In all, 10 healthy volunteers were evaluated for the following surface EMG (sEMG) parameters in the suprahyoid and infrahyoid muscles during swallowing: onset latency, offset latency, duration, peak latency, maximal amplitude during swallowing, and the area under curve (AUC) of the rectified EMG signal. The sEMG was recorded while the participants swallowed five times each of the four fluid volumes (saliva, 2 ml, 5 ml, and 20 ml of water), totaling to 20 swallows. Moreover, the intra-participant variability per parameter was evaluated using the coefficient of variation (CV). @*Results@#Suprahyoid muscles were activated 0.095 s (95% CI, 0.062-0.128) earlier than the infrahyoid muscles.Maximal amplitudes during the 20 ml swallow were 17.484 (−1.543-36.512) and 13.490 (1.254-25.727) μV higher than values obtained during the 2 ml swallow in the suprahyoid and infrahyoid muscles, respectively. Furthermore, the AUC of the rectified EMG signal increased with the volume of swallow in both muscle groups (P=0.003, suprahyoid; P＜0.002, infrahyoid). The intra-individual variabilities of offset latency, duration, and maximal amplitude were relatively low (＜30% CV) in both muscle groups with respect to other parameters. The assessment of each parameter using EMG was highly reliable, with an intraclass correlation coefficient of ＞0.8. @*Conclusion@#Among the variable sEMG parameters assessed, the offset latency, duration, and maximal amplitude were the least variable. Although reliability on the rater side showed good results, the swallow-to-swallow variability of the parameters need to be considered in swallowing studies using sEMG.
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Objective@#To evaluate the reliability of suprahyoid and infrahyoid electromyography (EMG) measurement during swallowing. @*Methods@#In all, 10 healthy volunteers were evaluated for the following surface EMG (sEMG) parameters in the suprahyoid and infrahyoid muscles during swallowing: onset latency, offset latency, duration, peak latency, maximal amplitude during swallowing, and the area under curve (AUC) of the rectified EMG signal. The sEMG was recorded while the participants swallowed five times each of the four fluid volumes (saliva, 2 ml, 5 ml, and 20 ml of water), totaling to 20 swallows. Moreover, the intra-participant variability per parameter was evaluated using the coefficient of variation (CV). @*Results@#Suprahyoid muscles were activated 0.095 s (95% CI, 0.062-0.128) earlier than the infrahyoid muscles.Maximal amplitudes during the 20 ml swallow were 17.484 (−1.543-36.512) and 13.490 (1.254-25.727) μV higher than values obtained during the 2 ml swallow in the suprahyoid and infrahyoid muscles, respectively. Furthermore, the AUC of the rectified EMG signal increased with the volume of swallow in both muscle groups (P=0.003, suprahyoid; P＜0.002, infrahyoid). The intra-individual variabilities of offset latency, duration, and maximal amplitude were relatively low (＜30% CV) in both muscle groups with respect to other parameters. The assessment of each parameter using EMG was highly reliable, with an intraclass correlation coefficient of ＞0.8. @*Conclusion@#Among the variable sEMG parameters assessed, the offset latency, duration, and maximal amplitude were the least variable. Although reliability on the rater side showed good results, the swallow-to-swallow variability of the parameters need to be considered in swallowing studies using sEMG.
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Objective@#This study aimed to investigate the blood-brain barrier (BBB) disruption in mild traumatic brain injury (mTBI) patients with post-concussion syndrome (PCS) using dynamic contrast-enhanced (DCE) magnetic resonance (MR) imaging and automatic whole brain segmentation. @*Materials and Methods@#Forty-two consecutive mTBI patients with PCS who had undergone post-traumatic MR imaging, including DCE MR imaging, between October 2016 and April 2018, and 29 controls with DCE MR imaging were included in this retrospective study. After performing three-dimensional T1-based brain segmentation with FreeSurfer software (Laboratory for Computational Neuroimaging), the mean Ktrans and vp from DCE MR imaging (derived using the Patlak model and extended Tofts and Kermode model) were analyzed in the bilateral cerebral/cerebellar cortex, bilateral cerebral/cerebellar white matter (WM), and brainstem. Ktrans values of the mTBI patients and controls were calculated using both models to identify the model that better reflected the increased permeability owing to mTBI (tendency toward higher Ktrans values in mTBI patients than in controls). The Mann-Whitney U test and Spearman rank correlation test were performed to compare the mean Ktrans and vp between the two groups and correlate Ktrans and vp with neuropsychological tests for mTBI patients. @*Results@#Increased permeability owing to mTBI was observed in the Patlak model but not in the extended Tofts and Kermode model. In the Patlak model, the mean Ktrans in the bilateral cerebral cortex was significantly higher in mTBI patients than in controls (p = 0.042). The mean vp values in the bilateral cerebellar WM and brainstem were significantly lower in mTBI patients than in controls (p = 0.009 and p = 0.011, respectively). The mean Ktrans of the bilateral cerebral cortex was significantly higher in patients with atypical performance in the auditory continuous performance test (commission errors) than in average or good performers (p = 0.041). @*Conclusion@#BBB disruption, as reflected by the increased Ktrans and decreased vp values from the Patlak model, was observed throughout the bilateral cerebral cortex, bilateral cerebellar WM, and brainstem in mTBI patients with PCS.
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Objective@#Thickening agents used in dysphagia diets to adjust the viscosity of foods adversely affect the inherent food flavors and colors. Chopped and ground foods have unfamiliar flavors, colors and textures, causing a loss of appetite. Therefore, this study aimed to develop a savory and easy-to-make dysphagia diet without changing the appearance and taste of foods, and evaluate the suitability of the newly developed diet for patients with dysphagia. @*Methods@#Twenty participants aged 55-85 years (8 patients with dysphagia and 12 healthy elderly) were recruited.The diet consisted of fried rice, hamburger steak, and soybean paste soup, where the solid foods were categorized as International Dysphagia Diet Standardisation Initiative (IDDSI) Level 5 (Minced and Moist), and the liquid foods were categorized as IDDSI Level 2 (Mildly Thick). To develop the dysphagia diet, textural modifications to the ingredients and viscosity adjustments were applied. A sensory evaluation was conducted by the panel to measure the extent of chewing, swallowing, adhesiveness, choking, and overall flavor and preference. @*Results@#No significant differences in textural properties, such as chewing, swallowing, adhesiveness and choking, were observed between the control and patient groups, but the flavor and preferences in the patient group were statistically significant. @*Conclusion@#The modified and newly designed dysphagia foods positively impacted easy swallowing for patients with dysphagia. Therefore, customized dysphagia foods should be considered in terms of flavor-enhancement to provide tailored diets for patients with dysphagia.
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Objective@#The purpose of this study was to understand the mechanism of normal hyoid movement during swallowing by calculating the activity of each muscle involved in the hyoid movement and propose a new kinetic modeling of hyoid movement using videofluoroscopy images. @*Methods@#Eight healthy volunteers with an average age of 56.8 swallowed 2-ml of diluted barium under videofluoroscopy. A video image was digitized to analyze the movement of the hyoid bone. The activity of the muscles acting on the hyoid bone was calculated from the movement of the hyoid bone using kinetic modeling. A surface electromyogram was measured simultaneously with videofluoroscopy, and the muscle force calculated by kinetic modeling was compared with the muscle force measured by surface EMG. @*Results@#The muscles acting on the hyoid bone were divided into three groups according to the direction of force and analyzed. The contraction of the retractor muscle group was observed as a median of 433 ms (95% CI 264-602, P=0.012) earlier than the contraction of protractor muscle group in all subjects. Generally, the peak activity of each muscle group was observed in the order of retractor (0 ms), protractor (592 ms, 95% CI 429-755), and depressor (717 ms, 95% CI 535-899) muscle group. The contraction of the protractor muscle measured by surface electromyography showed an earlier onset latency with a median of 82 2 ms (95% CI 615-102 9, P=0.012 ) compared to the contraction of the protractor muscle calculated by kinetic modeling. @*Conclusion@#Kinetic modeling reflects the pattern of contraction in the order of retractor, protractor, depressor muscle groups, as previously known. And it was possible to evaluate the activity of the retractor muscle, which is difficult to evaluate by electromyogram.
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Objective@#To analyze the rheological and biochemical properties of saliva in healthy adults. @*Methods@#The subjects were seven healthy young adults (20-39 years). The whole saliva was collected by the spitting method between 9:00 am and 12:00 am. Unstimulated saliva was collected first, which was followed by the collection of stimulated saliva using citric acid was collected. The viscosity was measured using a capillary viscometer to examine the rheological properties. The MUC5B concentration was analyzed using an enzyme-linked immunosorbent assay (ELISA) for the biochemical properties. @*Results@#Ten and five minutes were required on average for unstimulated saliva and stimulated saliva, respectively, to collect the minimum amount needed for analysis (8 ml). The flow rate increased from 1.037±0.323 ml/min to 1.823± 0.660 ml/min after stimulation (P=0.018). Citric acid stimulation also increased the MUC5B concentration in the saliva from 3.706±3.575 μg/ml to 6.928±2.03 μg/ml (P=0.028). The viscosity of saliva, however, did not show a significant difference between with (1.1±0.164 cSt) or without (1.019±0.08 cSt) stimulation (P=0.128). A positive correlation was observed between the flow rate and MUC5B concentration (Spearman’s rho=0.547, P=0.043). On the other hand, there was no significant correlation between the MUC5B concentration and viscosity both in the unstimulated and stimulated saliva (P=0.939 and 0.819, respectively). @*Conclusion@#No significant correlation was observed between the MUC5B concentration and viscosity. Considering the time required to collect samples, an analysis of the stimulated saliva appears feasible in various research settings.The feasibility of these analysis methods should be examined in a patient population.
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Toxoplasma gondii is an obligate intracellular protozoan parasite that can invade various organs in the host body, including the central nervous system. Chronic intracranial T. gondii is known to be associated with neuroprotection against neurodegenerative diseases through interaction with host brain cells in various ways. The present study investigated the neuroprotective effects of chronic T. gondii infection in mice with cerebral ischemia experimentally produced by middle cerebral artery occlusion (MCAO) surgery. The neurobehavioral effects of cerebral ischemia were assessed by measurement of Garcia score and Rotarod behavior tests. The volume of brain ischemia was measured by triphenyltetrazolium chloride staining. The expression levels of related genes and proteins were determined. After cerebral ischemia, corrected infarction volume was significantly reduced in T. gondii infected mice, and their neurobehavioral function was significantly better than that of the uninfection control group. Chronic T. gondii infection induced the expression of hypoxia-inducible factor 1-alpha (HIF-1α) in the brain before MCAO. T. gondii infection also increased the expression of vascular endothelial growth factor after the cerebral ischemia. It is suggested that chronic intracerebral infection of T. gondii may be a potential preconditioning strategy to reduce neural deficits associated with cerebral ischemia and induce brain ischemic tolerance through the regulation of HIF-1α expression.