Electrochemical Detection of Dopamine Release from Living Neurons Using Graphene Oxide-Incorporated Polypyrrole/Gold Nanocluster Hybrid Nanopattern Arrays.

Stem-cell-based therapeutics have shown immense potential in treating various diseases that are currently incurable. In particular, partial recovery of Parkinson's disease, which occurs due to massive loss or abnormal functionality of dopaminergic (DAnergic) neurons, through the engraftment of stem-cell-derived neurons ex vivo is reported. However, precise assessment of the functionality and maturity of DAnergic neurons is still challenging for their enhanced clinical efficacy. Here, a novel conductive cell cultivation platform, a graphene oxide (GO)-incorporated metallic polymer nanopillar array (GOMPON), that can electrochemically detect dopamine (DA) exocytosis from living DAnergic neurons, is reported. In the cell-free configuration, the linear range is 0.5-100 µm, with a limit of detection of 33.4 nm. Owing to its excellent biocompatibility, a model DAnergic neuron (SH-SY5Y cell) can be cultivated and differentiated on the platform while their DA release can be quantitatively measured in a real-time and nondestructive manner. Finally, it is showed that the functionality of the DAnergic neurons derived from stem cells can be precisely assessed via electrochemical detection of their DA exocytosis. The developed GOMPON is highly promising for a wide range of applications, including real-time monitoring of stem cell differentiation into neuronal lineages, evaluating differentiation protocols, and finding practical stem cell therapies.

Clinically distinct characteristics in patients younger than 40 years old with non-cardiac chest pain.

BACKGROUND AND AIM: Little is known about non-cardiac chest pain (NCCP) in young patients. We aimed to examine the proportion of gastroesophageal reflux disease (GERD) in young patients with NCCP compared to the average-aged NCCP patients and to evaluate their symptomatic characteristics and the clinical efficacy of a 2-week proton pump inhibitor (PPI) trial. METHODS: Ninety-six patients with NCCP≥1/week were classified into the young-aged (≤ 40 years, n =38) and the average-aged groups (>40 years, n=58). Typical reflux symptoms were assessed. The patients were defined into a GERD group and non-GERD group according to reflux esophagitis on esophagogastroduodenoscopy and/or pathologic acid exposure on 24-h esophageal pH monitoring. Then the patients were treated with 30mg of lansoprazole bid for 14 days. RESULTS: Nine patients (23%) in the young-aged group and 22 patients (38%) in average-aged group were diagnosed with GERD-related NCCP (P=0.144). The proportion of typical reflux symptoms was higher in the GERD group compared with the non-GERD group in both age groups. A PPI test improved symptoms in the GERD group irrespective of age, but this improvement was not observed in non-GERD group. CONCLUSIONS: In young NCCP patients, the prevalence of GERD was relatively low compared to average-aged NCCP, but the difference was insignificant. The PPI test was very effective in diagnosing GERD in the NCCP patients in both age groups. Therefore, in young NCCP patients, if there is a negative response to a 2-week PPI trial, the possibility of extra-esophageal disease origin needs to be considered.

ß-Sitosterol Attenuates Dexamethasone-Induced Muscle Atrophy via Regulating FoxO1-Dependent Signaling in C2C12 Cell and Mice Model.

Sarcopenia refers to a decline in muscle mass and strength with age, causing significant impairment in the ability to carry out normal daily functions and increased risk of falls and fractures, eventually leading to loss of independence. Maintaining protein homeostasis is an important factor in preventing muscle loss, and the decrease in muscle mass is caused by an imbalance between anabolism and catabolism of muscle proteins. Although ß-sitosterol has various effects such as anti-inflammatory, protective effect against nonalcoholic fatty liver disease (NAFLD), antioxidant, and antidiabetic activity, the mechanism of ß-sitosterol effect on the catabolic pathway was not well known. ß-sitosterol was assessed in vitro and in vivo using a dexamethasone-induced muscle atrophy mice model and C2C12 myoblasts. ß-sitosterol protected mice from dexamethasone-induced muscle mass loss. The thickness of gastrocnemius muscle myofibers was increased in dexamethasone with the ß-sitosterol treatment group (DS). Grip strength and creatine kinase (CK) activity were also recovered when ß-sitosterol was treated. The muscle loss inhibitory efficacy of ß-sitosterol in dexamethasone-induced muscle atrophy in C2C12 myotube was also verified in C2C12 myoblast. ß-sitosterol also recovered the width of myotubes. The protein expression of muscle atrophy F-box (MAFbx) was increased in dexamethasone-treated animal models and C2C12 myoblast, but it was reduced when ß-sitosterol was treated. MuRF1 also showed similar results to MAFbx in the mRNA level of C2C12 myotubes. In addition, in the gastrocnemius and tibialis anterior muscles of mouse models, Forkhead Box O1 (FoxO1) protein was increased in the dexamethasone-treated group (Dexa) compared with the control group and reduced in the DS group. Therefore, ß-sitosterol would be a potential treatment agent for aging sarcopenia.

Comparison of Fentanyl versus Meperidine in Combination with Midazolam for Sedative Colonoscopy in Korea.

BACKGROUND/AIMS: Combination of midazolam and opioids is used widely for endoscopic sedation. Compared with meperidine, fentanyl is reportedly associated with rapid recovery, turnover rate of endoscopy room, and quality of endoscopy. We compared fentanyl with meperidine when combined with midazolam for sedative colonoscopy. METHODS: A retrospective, cross-sectional, 1:2 matching study was conducted. Induction and recovery time were compared as the primary outcomes. Moreover, cecal intubation time, withdrawal time, total procedure time of colonoscopy, paradoxical reaction, adenoma detection rate, and adverse effect of midazolam or opioids were assessed as the secondary outcomes. RESULTS: A total of 129 subjects (43 fentanyl vs. 86 meperidine) were included in the analysis. The fentanyl group showed significantly more rapid induction time (4.5±2.7 min vs. 7.5±4.7 min, p<0.001), but longer recovery time (59.5±25.6 min vs. 50.3±10.9 min, p=0.030) than the meperidine group. In multivariate analysis, the induction time of the fentanyl group was 3.40 min faster (p<0.001), but the recovery time was 6.38 min longer (p=0.046) than that of the meperidine group. There was no difference in withdrawal time and adenoma detection rate between the two groups. CONCLUSION: The fentanyl group had more rapid sedation induction time but longer recovery time than the meperidine group.

Factors for cecal intubation time during colonoscopy in women: Impact of surgical history.

BACKGROUND/AIM: Cecal intubation during colonoscopy is prone to be prolonged in women, which may be related to frequent exposure to pelvic/abdominal surgery. We evaluated the association between Cecal Intubation Time (CIT) and prior episodes of pelvic/abdominal surgery in women. PATIENTS AND METHODS: A cross-sectional study was conducted on screening participants who underwent colonoscopy. Multivariate regression with parameter estimates (ß) was performed to determine the factors affecting CIT, including age, body mass index (BMI), bowel preparation, sedation, diverticulosis, experience of colonoscopists, and a surgical history. Also, subgroup analyses according to type of surgery were performed. RESULTS: A total of 835 women were enrolled. The mean CIT was 5.82 ± 3.40 min. 323 females (38.7%) had episodes of surgery. The CIT was prolonged in cases performed by non-experienced trainees (ß = 3.61, P< 0.001) and with a history of gynecological surgery (ß = 0.97, P = 0.001). In the subgroup of non-experienced trainees, lower BMI, poor preparation, and a history of cesarean section significantly prolonged the CIT. Also, the risk for difficult colonoscopy (CIT ≥ 15 min) was increased with a history of cesarean section (odds ratio = 4.43, P= 0.024). CONCLUSION: A prior episode of gynecological surgery prolonged CIT. Also, cesarean section history was associated with difficult colonoscopy in the examination by non-experienced trainees.

Clinical distinct features of noncardiac chest pain in young patients.

BACKGROUND/AIMS: Noncardiac chest pain (NCCP) is a very common disorder world-wide and gastroesophageal reflux disease (GERD) is known to be the most common cause. The prevalence of NCCP may tend to decrease with increasing age. However, there is little report about young aged NCCP. The aim of this study was to examine the prevalence of GERD and to evaluate the efficacy of proton pump inhibitor (PPI) test in the young NCCP patients. METHODS: Thirty patients with at least weekly NCCP less than 40 years were enrolled. The baseline symptoms were assessed using a daily symptom diary for 14 days. Esophago-gastro-duodenoscopy (EGD) and 24 hr esophageal pH monitoring were performed for the diagnosis of GERD and esophageal manometry was done. Then, patients were tried with lansoprazole 30 mg twice daily for 14 days, considering positive if a symptom score improved >/= 50% compared to the baseline. RESULTS: Nine (30%) of the patients were diagnosed with GERD at EGD and/or 24 hr esophageal pH monitoring, also, 3 (10%) were diagnosed with GERD-associated esophageal motility disorder and 3 (10%) were non GERD-associated. Concerning PPI test, GERD-related NCCP had a higher positive PPI test (n = 8, 89%) than non GERD-related NCCP (n = 5, 24%) (p = 0.002). CONCLUSIONS: In young patients with NCCP, a prevalence of GERD diagnosed using EGD and/or 24 hr esophageal pH monitoring was 30%. PPI test was very predictable on diagnosis of GERD-related NCCP, thus, PPI test in young NCCP patients may assist to the physician's clinical judgment of NCCP.