783 research outputs found

    Manipulation of Rat Movement via Nigrostriatal Stimulation Controlled by Human Visually Evoked Potentials

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    Here, we report that the development of a brain-to-brain interface (BBI) system that enables a human user to manipulate rat movement without any previous training. In our model, the remotely-guided rats (known as ratbots) successfully navigated a T-maze via contralateral turning behaviour induced by electrical stimulation of the nigrostriatal (NS) pathway by a brain-computer interface (BCI) based on the human controller's steady-state visually evoked potentials (SSVEPs). The system allowed human participants to manipulate rat movement with an average success rate of 82.2% and at an average rat speed of approximately 1.9 m/min. The ratbots had no directional preference, showing average success rates of 81.1% and 83.3% for the left-and right-turning task, respectively. This is the first study to demonstrate the use of NS stimulation for developing a highly stable ratbot that does not require previous training, and is the first instance of a training-free BBI for rat navigation. The results of this study will facilitate the development of borderless communication between human and untrained animals, which could not only improve the understanding of animals in humans, but also allow untrained animals to more effectively provide humans with information obtained with their superior perception.11Ysciescopu

    Dose selection method for pharmacokinetic study in hemodialysis patients using a subpharmacological dose: oseltamivir as a model drug

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    BACKGROUND: Dose selection is an important step in pharmacokinetic (PK) studies of hemodialysis patients. We propose a simulation-based dose-selection method for PK studies of hemodialysis patients using a subpharmacological dose of oseltamivir as a model drug. METHODS: The concentrations of oseltamivir and its active metabolite, oseltamivir carboxylate (OC), were measured by liquid chromatography-tandem mass spectrometry. To determine a low oseltamivir dose exhibiting PK linearity, a pilot low dose determination investigation (n = 4) was performed using a single administration dose-escalation study. After the dose was determined, a low dose study (n = 10) was performed, and the optimal dose required to reach the hypothetical target OC exposure (area under the concentration-time curve [AUC] of 60,000 ng · hr/mL) was simulated using a nonparametric superposition method. Finally, observed PKs at the optimal dose were compared to the simulated PKs to verify PK predictability. RESULTS: In the pilot low dose determination study, 2.5 mg of oseltamivir was determined to be the low dose. Subsequently, we performed a single-dose PK study with the low oseltamivir dose in an additional group of 10 hemodialysis patients. The predicted AUC(last) of OC following continuous oseltamivir doses was simulated, and 35 mg of oseltamivir corresponded to the hypothetical target AUC(last) of OC. The observed PK profiles of OC at a 35-mg oseltamivir dose and the simulated data based on the low dose study were in close alignment. CONCLUSION: The results indicate that the proposed method provides a rational approach to determine the proper PK dose in hemodialysis patients

    Solitary Small Bowel Metastasis from Breast Cancer

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    The common sites of metastasis of breast cancer are bone, lung, and liver, but gastrointestinal metastasis from breast cancer is rare. We experienced a case of solitary ileal metastasis from breast cancer. A 45-years-old woman presented with melena for several weeks. She showed no other abdominal symptoms. Colonoscopy findings showed an ulcerative mucosal lesion in the terminal ileum, and biopsy was performed. Pathologic examination revealed metastatic carcinoma, originated from breast. The tumor cells were positive for estrogen receptor and negative for Cdx-2. She had had a previous medical history of bilateral breast cancer and undergone breast conserving surgery with sentinel lymph node biopsy for both breasts. The torso positron emission tomography scan at 19 months after surgery showed mildly increased uptake in the terminal ileum which was considered as inflammation. Finally, she was diagnosed with solitary ileal metastasis from breast cancer at 22 months after surgery

    Quick Sepsis-related Organ Failure Assessment score is not sensitive enough to predict 28-day mortality in emergency department patients with sepsis: a retrospective review

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    Objective To test the hypothesis that the quick Sepsis-related Organ Failure Assessment (qSOFA) score, derived from vital signs taken during triage and recommended by current sepsis guidelines for screening patients with infections for organ dysfunction, is not sensitive enough to predict the risk of mortality in emergency department (ED) sepsis patients. Methods Patients diagnosed with severe sepsis and septic shock using the old definition between May 2014 and April 2015 were retrospectively reviewed in three urban tertiary hospital EDs. The sensitivities of systemic inflammatory response syndrome (SIRS) criteria, qSOFA, and Sequential Organ Failure Assessment (SOFA) scores ≥2 were compared using McNemar’s test. Diagnostic performances were evaluated using specificity, positive predictive value, and negative predictive value. Results Among the 928 patients diagnosed with severe sepsis or septic shock using the old definition, 231 (24.9%) died within 28 days. More than half of the sepsis patients (493/928, 53.1%) and more than one-third of the mortality cases (88/231, 38.1%) had a qSOFA score <2. The sensitivity of a qSOFA score ≥2 was 61.9%, which was significantly lower than the sensitivity of SIRS ≥2 (82.7%, P<0.001) and SOFA ≥2 (99.1%, P<0.001). The specificity, positive predictive value, and negative predictive value of a qSOFA score ≥2 for 28-day mortality were 58.1%, 32.9%, and 82.2%, respectively. Conclusion The current clinical criteria of the qSOFA are less sensitive than the SIRS assessment and SOFA to predict 28-day mortality in ED patients with sepsis

    Hyperchloremia is associated with poor renal outcome after coronary artery bypass grafting

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    Background Hyperchloremia is associated with the risks of several morbidities and mortality. However, its relationship with acute kidney injury (AKI) and end-stage renal disease (ESRD) in patients undergoing coronary artery bypass grafting (CABG) remains unresolved. Methods A total of 2977 patients undergoing CABG between 2003 and 2015 were retrospectively reviewed from two tertiary hospitals. Patients were categorized by serum chloride levels into normochloremia (95–105 mmol/L), mild hyperchloremia (106–110 mmol/L), and severe hyperchloremia (> 110 mmol/L). The odds ratios (ORs) for AKI and hazard ratios (HRs) for ESRD were calculated after adjustment for multiple covariates. The death-adjusted risk of ESRD was additionally evaluated. Results Postoperative AKI occurred in 798 patients (26.5%). The hyperchloremia group had a higher risk of AKI than the normochloremia group, wherein the risk was incremental depending on the severity of hyperchloremia, as follows: ORs were 1.26 (1.06–1.51) and 1.95 (1.52–2.51) in the mild and severe hyperchloremia groups, respectively. During a median period of 7 years (maximum 15 years), 70 patients (2.3%) had ESRD. The severe hyperchloremia group was at an elevated risk of ESRD compared with the normochloremia group, with an HR of 2.43 (1.28–4.63). Even after adjusting for the competing risk of death, hyperchloremia was associated with the risk of ESRD. Conclusions Preoperative hyperchloremia is associated with poor renal outcomes such as AKI and ESRD after CABG. Accordingly, serum chloride should be monitored in patients undergoing CABG.This research was supported by grant No. 2019R1A2C1085411 from the National Research Foundation

    Efficacy and Safety of Pueraria lobata Extract in Gray Hair Prevention: A Randomized, Double-Blind, Placebo-Controlled Study

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    Background: Graying of hair?a sign of aging?raises cosmetic concerns. Individuals with gray hair often look older than others their age; therefore, some dye their hair for aesthetic purposes. However, hair colorants can induce many problems including skin irritation, allergic reaction and hair-breakage. Objective: This randomized, double-blind clinical trial was performed in order to examine the effects of APHG-1001, a compound including an extract from Pueraria lobata, on graying hair. Methods: A total of 44 female subjects were randomly treated with either APHG-1001 or placebo twice daily for 24 weeks. Using the phototrichogram analysis, a count of newly developed gray hair was estimated. Investigator assessment and subject self-assessment were also performed in order to evaluate the efficacy of the compound. Results: The mean number of newly developed gray hair at 24 weeks was 6.3/cm2 in the APHG-1001 group and 11.4/cm2 in the placebo group; the difference was statistically significant (p<0.05). However, the investigator assessment and subject self-assessment did not show any significant change in the gross appearance of hair grayness by the end of the study. No severe adverse events in either group were observed. Moreover, the incidence of adverse events did not differ between the groups. Conclusion: This clinical trial revealed that APHG- 1001, which contains an extract of P. lobata, could prevent the development of new gray hair without any remarkable adverse effects. Thus, it can be considered as a viable treatment option for the prevention of gray hair. (Ann Dermatol 25(2) 218∼222, 2013)OAIID:oai:osos.snu.ac.kr:snu2013-01/102/0000045457/3SEQ:3PERF_CD:SNU2013-01EVAL_ITEM_CD:102USER_ID:0000045457ADJUST_YN:NEMP_ID:A079130DEPT_CD:801CITE_RATE:.531FILENAME:jo sj, et al ann dermatol 2013.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:YCONFIRM:

    Video-Assisted Thoracoscopic Surgery for Correction of Adolescent Idiopatic Scoliosis: Comparison of 4.5 mm versus 5.5 mm Rod Constructs

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    PURPOSE: The purpose of this study is to report the comparative results of thoracoscopic correction achieved via cantilever technique using a 4.5 mm thin rod and the poly-axial reduction screw technique using a 5.5 mm thick rod in Lenke type 1 adolescent idiopathic scoliosis (AIS). MATERIALS AND METHODS: Radiographic data, Scoliosis Research Society (SRS) patient-based outcome questionnaires, and operative records were reviewed for forty-nine patients undergoing surgical treatment of scoliosis. The study group was divided into a 4.5 mm thin rod group (n = 24) and a 5.5 mm thick rod group (n = 25). The radiographic parameters that were analyzed included coronal curve correction, the most caudal instrumented vertebra tilt angle correction, coronal balance, and thoracic kyphosis. RESULTS: The major curve was corrected from 49.8 degrees and 47.2 degrees pre-operatively to 24.5 degrees and 18.8 degrees at the final follow-up for the thin and thick rod groups, respectively (50.8% vs. 60.2% correction). There were no significant differences between the two groups in terms of kyphosis, coronal balance, or tilt angle at the time of the final follow-up. The mean number of levels fused was 6.2 in the thin rod group, compared with 5.9 levels in the thick rod group. There were no major intraoperative complications in either group. CONCLUSION: Significant correction loss was observed in the thin rod system at the final follow-up though both groups had comparable correction immediately post-operative. Therefore, the thick rod with poly axial screw system helps to maintain post-operative correctionope
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