Production of cis-Vaccenic Acid-oriented Unsaturated Fatty Acid in Escherichia coli

도경희,박혜민,김세경,윤현식 한국생물공학회 2018 Biotechnology and Bioprocess Engineering Vol.23 No.1

Biodiesel is produced worldwide as an alternative energy fuel and substitute for petroleum. Biodiesel is often obtained from vegetable oil, but production of biodiesel from plants requires additional land for growing crops and can affect the global food supply. Consequently, it is necessary to develop appropriate microorganisms for the development of an alternative biodiesel feedstock. Escherichia coli is suitable for the production of biodiesel feedstocks since it can synthesize fatty acids for lipid production, grows well, and is amenable to genetic engineering. Recombinant E. coli was designed and constructed for the production of biodiesel with improved unsaturated fatty acid contents via regulation of the FAS pathway consisting of initiation, elongation, and termination steps. Here, we investigated the effects of fabA, fabB, and fabF gene expression on the production of unsaturated fatty acids and observed that the concentration of cis-vaccenic acid, a major component of unsaturated fatty acids, increased 1.77-fold compared to that of the control strain. We also introduced the genes which synthesize malonyl-ACP used during initiation step of fatty acid synthesis and the genes which produce free fatty acids during termination step to study the effect of combination of genes in elongation step and other steps. The total fatty acid content of this strain increased by 35.7% compared to that of the control strain. The amounts of unsaturated fatty acids and cis-vaccenic acid increased by 3.27 and 3.37-fold, respectively.

Isosorbide Concentration in Perilymph of the Guinea Pig After Oral Administration Versus That After Round Window Perfusion

김민범,도경희,김규성 대한이비인후과학회 2014 Clinical and Experimental Otorhinolaryngology Vol.7 No.4

Objectives. The aims of this study were to investigate the feasibility of isosorbide delivery into perilymph through the round window membrane (RWM), and to compare the intracochlear isosorbide concentration in perilymph after oral administration (PO) versus that after round window perfusion (RWP). Methods. Sixteen male guinea pigs (32 ears) were used. Isosorbide, an osmotic diuretic, was administered via RWP or PO. First, to investigate the optimal perfusion time, perilymph sampling of scala tympani from the RWM was performed after RWP for 15, 30, or 60 minutes. Second, to compare the drug concentration after RWP versus that after PO, perilymph was aspirated at 3 and 6 hours after administration. Intracochlear concentration of isosorbide was ana- lyzed by high-performance liquid chromatography coupled to refractive index detection. Results. Isosorbide passed through the RWM into perilymph after RWP. After RWP for 15, 30, and 60 minutes, mean iso- sorbide concentrations in perilymph were 116.27±44.65, 245.48±112.84, and 279.78±186.32 mM, respectively. The intracochlear concentration after RWP for 30 minutes was higher than that after RWP for 15 minutes (P=0.043). At 3 and 6 hours after PO, isosorbide concentrations in perilymph were 28.88±4.69 and 12.67±2.28 mM, respec- tively. In contrast, the corresponding concentrations after RWP were 117.91±17.70 and 75.03±14.82 mM at 3 and 6 hours, respectively. Isosorbide concentrations in perilymph following RWP were significantly higher than those fol- lowing PO at both 3 and 6 hours (P=0.025 and P=0.034, respectively). Conclusion. Isosorbide can rapidly pass through the RWM after RWP in guinea pigs, and 30 minutes of perfusion is con- sidered to be appropriate. In addition, over a 6-hour period, RWP can deliver higher concentrations of isosorbide into perilymph than those achieved with PO.

Effect of Repetitive Transcranial Magnetic Stimulation on Patients With Dysarthria After Subacute Stroke

권용규,도경희,박성정,장민철,전민호 대한재활의학회 2015 Annals of Rehabilitation Medicine Vol.39 No.5

Objective To evaluate whether repetitive transcranial magnetic stimulation (rTMS) could improve dysarthria in stroke patients at the subacute stage.Methods This study was a prospective, randomized, double-blind controlled trial. Patients who had unilateral middle cerebral artery infarction were enrolled. In patients in the rTMS group, we found hot spots by searching for the evoked motor potential of the orbicularis oris on the non-affected side. We performed rTMS at a low frequency (1 Hz), 1,500 stimulations/day, 5 days a week for 2 weeks on the hotspots. We used the same protocol in the sham stimulation group patients as that in the rTMS group, except that the angle of the coil was perpendicular to the skull rather than tangential to it. The patients in both groups received speech therapy for 30 minutes, 5 days a week from a skilled speech therapist. The speech therapist measured the Urimal Test of Articulation and Phonology, alternative motion rates, sequential motion rates, and maximal phonation time before and after intervention sessions.Results Forty-two patients were enrolled in this study and 20 completed the study. Statistical analysis revealed significant improvements on the dysarthria scales in both groups. The sequential motion rate (SMR)-PəTəKə showed significantly greater improvement in the rTMS group patients than in the sham stimulation group.Conclusion Patients in the rTMS group showed greater improvement in articulation than did patients in the sham rTMS group. Therefore, rTMS can have a synergistic effect with speech therapy in treating dysarthria after stroke.

Clinical Predictors of Oro-esophageal Tube Feeding Success in Brain Injury Patients With Dysphagia

전윤목,전민호,도경희,최수진 대한재활의학회 2017 Annals of Rehabilitation Medicine Vol.41 No.5

Objective To identify possible clinical predictors of intermittent oro-esophageal (OE) tube feeding success, and evaluate the clinical factors associated with OE tube treatment.Methods A total of 135 dysphagic patients were reviewed, who received OE tube treatment and were hospitalized in the department of rehabilitation medicine between January 2005 and December 2014. The 76 eligible cases enrolled were divided into two groups, based on the OE tube training success. Clinical factors assessed included age, cause of brain lesion, gag reflex, cognitive function and reasons for OE tube training failure.Results Of the 76 cases enrolled, 56 study patients were assigned to the success group, with the remaining 20 in the failure group. There were significant differences between these two groups in terms of age, gag reflex, ability to follow commands, and the score of Korean version of Mini-Mental Status Examination (K-MMSE). Location of the brain lesion showed a borderline significance. Multivariable analysis using logistic regression revealed that age, cause of brain lesion, gag reflex, and K-MMSE were the main predictors of OE tube training success.Conclusion A younger age, impaired gag reflex and higher cognitive function (specifically a K-MMSE score ≥19.5) are associated with an increased probability of OE tube training success in dysphagic patients.

Neurocognitive Dysfunction According to Hypoperfusion Territory in Patients With Moyamoya Disease

강창구,전민호,강정아,도경희,최수진 대한재활의학회 2017 Annals of Rehabilitation Medicine Vol.41 No.1

Objective To demonstrate the prevalence of cerebral hypoperfusion without focal cerebral lesions in patients with Moyamoya disease (MMD), and the relationship between areas of hypoperfusion and cognitive impairment.Methods Twenty-six MMD patients were included. Patients were categorized according to the presence/absence of hypoperfusion in the frontal, parietal, temporal, and occipital lobes on brain single-photon-emission computed tomography (SPECT) after acetazolamide challenge. Computerized neuropsychological test (CNT) results were compared between groups.Results Only 3 patients showed normal cerebral perfusion. Baseline characteristics were similar between groups. Patients with frontal lobe hypoperfusion showed lower scores in visual continuous performance test (CPT), auditory CPT, forward digit span test, backward digit span test, verbal learning test, and trail-making test. Patients with parietal lobe hypoperfusion showed lower backward digit span test, visual learning test, and trail-making test scores. Related to temporal and occipital lobes, there were no significant differences in CNT results between the hypoperfusion and normal groups.Conclusion MMD patients without focal cerebral lesion frequently exhibit cerebral hypoperfusion. MMD patients with frontal and parietal hypoperfusion had abnormal CNT profiles, similar to those with frontal and parietal lesions. It is suggested that the hypoperfusion territory on brain SPECT without focal lesion may affect the characteristics of neurocognitive dysfunction in MMD patients.