Cortical recording with conducting polymer electrodes

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (leaves 39-41).The ability to record from the same neuron for extended periods of time is essential to understanding how the brain reorganizes during motor learning. Conventional chronic recording microelectrodes are made from metal or silicon. However, the large stiffness mismatch between the electrodes and brain tissue causes shear-induced inflammation, limiting long-term recording stability. The flexibility of a polypyrrole microwire has the potential to improve the chronic recording stability by minimizing the stiffness mismatch. This thesis shows the fabrication of conducting polymer electrodes and the stability of their impedance in physiological saline. The initial impedance was as low as 70 k[omega], but the electrode impedance increased by a factor of 10 when immersed in saline over 370 hours. This conducting polymer microwire electrode was implanted in a rodent brain and successfully used to record neuronal action potentials.by Woong Jin Bae.S.M

Rejuvenating Star Formation Activity in an Early-type Dwarf Galaxy, LEDA 1915372, with Accreted HI Gas

We report a rare astrophysical phenomenon, in which an early-type dwarf galaxy (dE), LEDA 1915372, is accreting gas from a nearby star-forming dwarf galaxy, MRK 0689, and is rejuvenating star-formation activity at the center. Both LEDA 1915372 and MRK 0689 have similar brightness of $M_{r}$ = $-$16.99 and $-$16.78 mag, respectively. They are located in a small group environment, separated by a sky-projected distance of 20.27 kpc (up to 70 kpc in three dimension), and have a relative line-of-sight radial velocity of 6 km/s. The observation of 21 cm emission with the Giant Metrewave Radio Telescope provides strong evidence of interaction between the pair dwarf galaxies in terms of neutral hydrogen (HI) morphology and kinematics. In particular, the HI map reveals that the two galaxies are clearly connected by a gas bridge, and the gas components of both LEDA 1915372 and MRK 0689 share a common direction of rotation. We also find that the HI emission peak deviates from LEDA 1915372 toward its optical blue plume, suggesting a tidal origin of ongoing central star formation. Our findings provide a new path to the formation of blue-cored dEs.Comment: Accepted for publication in ApJ

Neuro-inflammation induced by lipopolysaccharide causes cognitive impairment through enhancement of beta-amyloid generation

<p>Abstract</p> <p>Background</p> <p>Alzheimer's disease (AD) is characterized by extensive loss of neurons in the brain of AD patients. Intracellular accumulation of beta-amyloid peptide (Aβ) has also shown to occur in AD. Neuro-inflammation has been known to play a role in the pathogenesis of AD.</p> <p>Methods</p> <p>In this study, we investigated neuro-inflammation and amyloidogenesis and memory impairment following the systemic inflammation generated by lipopolysaccharide (LPS) using immunohistochemistry, ELISA, behavioral tests and Western blotting.</p> <p>Results</p> <p>Intraperitoneal injection of LPS, (250 μg/kg) induced memory impairment determined by passive avoidance and water maze tests in mice. Repeated injection of LPS (250 μg/kg, 3 or 7 times) resulted in an accumulation of Aβ_1–42in the hippocampus and cerebralcortex of mice brains through increased β- and γ-secretase activities accompanied with the increased expression of amyloid precursor protein (APP), 99-residue carboxy-terminal fragment of APP (C99) and generation of Aβ_1–42as well as activation of astrocytes <it>in vivo</it>. 3 weeks of pretreatment of sulindac sulfide (3.75 and 7.5 mg/kg, orally), an anti-inflammatory agent, suppressed the LPS-induced amyloidogenesis, memory dysfunction as well as neuronal cell death <it>in vivo</it>. Sulindac sulfide (12.5–50 μM) also suppressed LPS (1 μg/ml)-induced amyloidogenesis in cultured neurons and astrocytes <it>in vitro</it>.</p> <p>Conclusion</p> <p>This study suggests that neuro-inflammatory reaction could contribute to AD pathology, and anti-inflammatory agent could be useful for the prevention of AD.</p

Role of age and sex in determining antibiotic resistance in febrile urinary tract infections

SummaryObjectivesTo identify the age- and sex-specific antimicrobial susceptibility patterns of Gram-negative bacteria (GNB) in outpatient febrile urinary tract infections (UTIs) in Korea.MethodsA total 2262 consecutive samples collected from patients aged 1–101 years with febrile UTIs, during the period January 2012 to December 2014, were analyzed in this multicentre, retrospective cohort study.ResultsThe sensitivities to cefotaxime and cefoxitin were over 85% for females but under 75% for males. Sex played an important role in the susceptibility of GNB to cefotaxime (p<0.001) and cefoxitin (p<0.001). The sensitivity to ciprofloxacin (age >20 years) was under 75% in both sexes, and was not influenced by sex (p=0.204). Age distributions of the incidences of resistance to cefotaxime, cefoxitin, and ciprofloxacin (age >20 years) were similar to the age distribution of the incidence of GNB, which indicates that the resistance patterns to these drugs were not affected by age (Kolmogorov–Smirnov test, female/male: p=0.927/p=0.509, p=0.193/p=0.911, and p=0.077/p=0.999, respectively).ConclusionsAge is not a considerable factor in determining the antibiotic resistance in febrile UTIs. Ciprofloxacin should be withheld from both sexes until culture results indicate its use. Second- or third-generation cephalosporins such as cefoxitin and cefotaxime can be used empirically only in females

Transplantation of Muscle-Derived Stem Cells into the Corpus Cavernosum Restores Erectile Function in a Rat Model of Cavernous Nerve Injury

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A Case of Anaphylaxis to Oral Minocycline

Minocycline is a semisynthetic tetracycline derivative that is often used in the treatment of acne vulgaris. To date, there has been only one case report of anaphylaxis to minocycline. We report here a case of anaphylaxis to oral minocycline. A 56-yr-old woman visited our hospital after three episodes of recurrent anaphylaxis. We performed an oral challenge test, the standard method for diagnosing drug allergies, with minocycline, one of the drugs she had taken previously. She developed urticaria, angioedema, nausea, vomiting, hypotension, and dyspnea within 4 min and was treated with intramuscular epinephrine, intravenous antihistamine and systemic corticosteroid. However, she presented similar symptoms at 50 min and at 110 min. In prescribing oral minocycline, physicians should consider the possibility of serious adverse reactions, such as anaphylaxis

Genome sequence of the moderately halophilic bacterium Salinicoccus carnicancri type strain CrmT (= DSM 23852T)

Salinicoccus carnicancri Jung et al. 2010 belongs to the genus Salinicoccus in the family Staphylococcaceae. Members of the Salinicoccus are moderately halophilic and originate from various salty environments. The halophilic features of the Salinicoccus suggest their possible uses in biotechnological applications, such as biodegradation and fermented food production. However, the genus Salinicoccus is poorly characterized at the genome level, despite its potential importance. This study presents the draft genome sequence of S. carnicancri strain Crm(T) and its annotation. The 2,673,309 base pair genome contained 2,700 protein-coding genes and 78 RNA genes with an average G+C content of 47.93 mol%. It was notable that the strain carried 72 predicted genes associated with osmoregulation, which suggests the presence of beneficial functions that facilitate growth in high-salt environments.

A Randomized, Double-Blind, Placebo-Controlled, Bridging Study to Evaluate the Efficacy and Safety of Vibegron in Treating Korean Patients With Overactive Bladder

Purpose Vibegron, a novel, potent β3 agonist, has been approved for clinical use in overactive bladder (OAB) treatment in Japan and the Unites States. We performed a bridging study to investigate the efficacy and safety of a daily 50-mg vibegron (code name JLP-2002) dose in Korean patients with OAB. Methods A multicenter, randomized, double-blind, placebo-controlled study was conducted from September 2020 to August 2021. Adult patients with OAB with a symptom duration of more than 6 months entered a 2-week placebo run-in phase. Eligibility was assessed at the end of this phase and selected patients entered a double-blind treatment phase after 1:1 randomization to either the placebo or vibegron (50 mg) group. The study drug was administered once daily for 12 weeks and follow-up visits were scheduled at weeks 4, 8, and 12. The primary endpoint was the change in mean daily micturition at the end of treatment. The secondary endpoints included changes in OAB symptoms (daily micturition, nocturia, urgency, urgency incontinence, and incontinence episodes, and mean voided volume per micturition) and safety. A constrained longitudinal data model was used for statistical analysis. Results Patients who took daily vibegron had significant improvements over the placebo group in both primary and secondary endpoints, except for daily nocturia episodes. The proportions of patients with normalized micturition and resolution of urgency incontinence and incontinence episodes were significantly higher in vibegron group than in the placebo. Vibegron also improved the patients’ quality of life with higher satisfaction rates. The incidence of adverse events in the vibegron and placebo groups was similar with no serious, unexpected adverse drug reactions. No abnormality in electrocardiographs was observed as well as no significant increase in postvoid residual volume. Conclusions Once daily vibegron (50 mg) for 12 weeks was effective, safe, and well-tolerated in Korean patients with OAB