Kyoung Sup Hong

Effect of Probiotics on Symptoms in Korean Adults with Irritable Bowel Syndrome

Background/Aims Irritable bowel syndrome (IBS) is a troublesome disease. Some strains of probiotics reportedly exert remarkable immunomodulatory effects, and so we designed a prospective double-blind randomized placebo-controlled clinical study to assess their effects in Korean adults with IBS. Methods IBS patients who met Rome III criteria were randomly assigned to receive composite probiotics or placebo. A total of 20 billion lyophilized bacteria were administered twice daily for 8 weeks. Primary outcome variables were symptom scores consisting of abdominal pain, flatulence, defecation discomfort, and sum of symptom scores. A visual analogue scale was used to quantify the severity. Secondary outcome variables consisted of the quality of life and bowel habits including defecation frequency and stool form. Results Thirty-six and 34 patients were randomized to the probiotics and placebo groups, respectively. Intention-to-treat analysis showed significant reductions in pain after 8 weeks of treatment: -31.9 and -17.7 in the probiotics and placebo groups, respectively (p=0.045). The reductions in abdominal pain, defecation discomfort, and sum of scores were more significant in 58 patients with a score of at least 3 on the baseline stool-form scale. Conclusions Composite probiotics containing Bifidobacterium bifidum BGN4, Lactobacillus acidophilus AD031, and other species are safe and effective, especially in patients who excrete normal or loose stools.

Anatase-to-rutile transition of titania thin films prepared by MOCVD

Phase transitions of TiO{sub 2} thin films prepared by MOCVD were investigated using X-ray diffraction, scanning electron microscope, transmission electron microscope, and secondary ion mass spectroscope. It was found that the in-situ deposited thin films showed the onset of anatase-to-rutile transition at a much lower temperature of 400 C. In order to reveal the mechanism responsible for the low temperature transition, the transition of titanium iso-propoxide derived and titanium tetra-chloride derived powders were investigated. The onset temperatures of transition were 450 C and 700 C, respectively. It is therefore suggested that source effect is the main mechanism of low temperature transition. It is also suggested that the heterogeneous nucleation on the surface of substrate is responsible for the transition shown by in-situ deposited and post-annealed titania thin films being much faster than that shown by titanium powders.

Metabonomic understanding of probiotic effects in humans with irritable bowel syndrome.

Goals This study was undertaken to evaluate the effects of probiotics on adult patients with irritable bowel syndrome (IBS) through clinical parameters and 1H nuclear magnetic resonance (NMR)-based metabonomics. Background As systematic effect of probiotics on inflammatory bowel disease through metabonomics approach has been extensively studied to date, metabonomic characterization of the probiotics effect on IBS is also needed for better understanding the effect with respect to host metabolic mechanism. Study Seventy-four IBS patients meeting Rome criteria were randomized to receive probiotics and placebo through a parallel-group, double-blind, randomized, placebo-controlled clinical study. Probiotic fermented milk and placebo were administered 3 times daily for 8 weeks. Improvements of IBS were assessed according to Rome III questionnaires and 1H NMR metabolic profiling of serum and fecal samples from all participants was used to characterize a significant change in serum and fecal metabolome before and after probiotics. Results Fecal counts of the Lactobacilli, but not Bifidobacteria species, which included in the probiotic milk, were increased significantly in feces of IBS patients receiving treatment (P=0.014). NMR data set coupled with multivariate statistical analysis identified intrinsically elevated serum levels of glucose (P=0.0265) and tyrosine (P=0.0016) in IBS patients. These levels normalized to those of healthy individuals in the probiotic administration group, but not the placebo group. Conclusions This metabonomic study suggests that in a subset of IBS patients there exists a potential dysregulation in energy homeostasis (serum glucose) and liver function (serum tyrosine) that may be improved through probiotics supplementation. Moreover, global metabolic profiling highlights the potential of metabonomic approach for assessing bowel diseases or symptoms with respect to host metabolic perturbation.

Crystallization of amorphous alloy Co68Fe4Cr4Si13B11

Crystallization of amorphous alloy Co68Fe4Cr4Si13B11 was analyzed by X-ray diffraction, transmission electron microscopy and differential scanning calorimetry. The polymorphic crystallization of cobalt and eutectic crystallization of cobalt and Co3B were observed during the crystallization of the alloy. The Avrami constant was found to be 1.65, indicating that crystallization of the glass is dominated by three-dimensional diffusion controlled growth with a near zero nucleation rate. The onset of crystallization of Co68Fe4Cr4Si13B11 alloy was found to be above 773 K which was higher than those of Cr-free Co-rich amorphous alloy. The magnetic property of crystallized samples was also correlated to the microstructure during crystallization.

Microstructure and crystallization kinetics of amorphous metallic alloy: Fe54Co26Si6B14

Abstract Magnetic properties and microstructural evolution of the amorphous Co26Fe54B14Si6 alloy during thermal annealing were characterized using transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). TEM demonstrated that, similar to the Co-free iron glass system, the amorphous Co26Fe54B14Si6 alloy crystallizes through two stages: initial development of α-(Fe,Co) dendrites and eutectic reaction due to the solute enrichment. Through the DSC analysis, the activation energy for the initial dendritic crystallization was determined to be 208 kJ/mol, which is considerably lower than that of Co-free system, indicating that the addition of Co in the glass system destabilize the amorphous structure and promotes devitrification. The magnetic property of the material was also correlated to the microstructure developed during the crystallization process. The coercivity of the material was observed to increase steadily as the crystallization process proceeded due to increasing density of α-(Fe,Co) crystallites providing domain wall pinning sites.

Conventional versus nerve-sparing radical surgery for cervical cancer: a meta-analysis

Objective Although nerve-sparing radical surgery (NSRS) is an emerging technique for reducing surgery-related dysfunctions, its efficacy is controversial in patients with cervical cancer. Thus, we performed a meta-analysis to compare clinical outcomes, and urinary, anorectal, and sexual dysfunctions between conventional radical surgery (CRS) and NSRS. Methods After searching PubMed, Embase, and the Cochrane Library, two randomized controlled trials, seven prospective and eleven retrospective cohort studies were included with 2,253 patients from January 2000 to February 2014. We performed crude analyses and then conducted subgroup analyses according to study design, quality of study, surgical approach, radicality, and adjustment for potential confounding factors. Results Crude analyses showed decreases in blood loss, hospital stay, frequency of intraoperative complications, length of the resected vagina, duration of postoperative catheterization (DPC), urinary frequency, and abnormal sensation in NSRS, whereas there were no significant differences in other clinical parameters and dysfunctions between CRS and NSRS. In subgroup analyses, operative time was longer (standardized difference in means, 0.948; 95% confidence interval [CI], 0.642 to 1.253), while intraoperative complications were less common (odds ratio, 0.147; 95% CI, 0.035 to 0.621) in NSRS. Furthermore, subgroup analyses showed that DPC was shorter, urinary incontinence or frequency, and constipation were less frequent in NSRS without adverse effects on survival and sexual functions. Conclusion NSRS may not affect prognosis and sexual dysfunctions in patients with cervical cancer, whereas it may decrease intraoperative complications, and urinary and anorectal dysfunctions despite long operative time and short length of the resected vagina when compared with CRS.

Domain structure of polycrystalline MnZn ferrites

Abstract The magnetic domain structure of sintered MnZn ferrites was observed using the Bitter method, Lorentz microscopy and Colloid-SEM method. The Bitter method revealed that the domain structure of the surface is stripe-like. Under an external magnetic field, the Bitter method showed the domain wall motion during the initial magnetization process and the irregular motion of domain wall near the saturation magnetic field (90∼120 Oe). Using Lorentz microscopy, the closure domain, which is characteristic of the soft magnetic materials, and the bulging of the domain wall were directly observed. In the Colloid-SEM method, the domain structure was observed as a function of the oxygen partial pressure during the sintering process. As atmospheric parameter, a , increased, the roughness of the domain wall increased, while the initial permeability decreased.

Rifaximin for the treatment of acute infectious diarrhea

Rifaximin is a nonabsorbable rifamycin derivative with an excellent safety profile and a broad spectrum of antimicrobial activity against a variety of enteropathogens causing acute infectious diarrhea. After oral ingestion, its bioavailability is known to be less than 0.4%, and it has a low potential for significant drug interactions. In the treatment of travelers’ diarrhea caused by noninvasive diarrheagenic Escherichia coli, it has been demonstrated that rifaximin significantly shortens the duration of diarrhea and has an efficacy similar to that of ciprofloxacin. Moreover, according to two randomized placebo-controlled trials, prophylactic treatment with rifaximin reduced the risk of developing travelers’ diarrhea by more than 50% compared with the placebo group. For the treatment of acute diarrhea unrelated to travel, a short course of rifaximin significantly reduced the duration of diarrhea, and its overall efficacy was comparable to that of ciprofloxacin. The discrepancy between the in vitro and in vivoantimicrobial activities of rifaximin, however, and the clinical implication of the rapid appearance of bacterial resistance, must be further elucidated. In conclusion, this gut-selective antibiotic seems to be a promising option for the treatment of acute infectious diarrhea secondary to noninvasive E. coli and also appears to be effective in chemoprophylaxis for travelers’ diarrhea.

Synthesis of low thermal expansion ceramics based on CaZr4(PO4)6-Li2O system

Abstract Ultra-low thermal expansion ceramics based upon CaZr 4 (PO 4 ) 6 –Li 2 O system were synthesized through solid state sintering. Lithium oxide was introduced to the CaZr 4 (PO 4 ) 6 lattice to promote liquid phase sintering to form CaZr 4 (PO 4 ) 6 with strongly negative thermal expansion. A small addition of Li 2 O has improved the densification rate, but also caused an excessive grain growth, which resulted in extensive microcracking. The microcracking lowered the bulk thermal expansion to −6×10 −6 °C −1 . Excessive amount of Li 2 O content also led to formation of the secondary phase, Li 2 Zr(PO 4 ) 2 , and also caused the swelling of the CaZr 4 (PO 4 ) 6 phase to lower the sintered density. An addition of over 5% of lithium oxide, the glass phase surrounding the CaZr 4 (PO 4 ) 6 grain, together with the secondary phase increased the thermal expansion. At 2.5% addition, there was an indication that the viscous glassy phase has partially relieved the stresses associated with the thermal expansion anisotropy during cooling from the processing temperature. It was demonstrated that the microstructure of the CaZr 4 (PO 4 ) 6 could be altered by adding varying amount of lithium oxide to tailor the thermophysical properties of the material.

Impedance spectroscopic study on the magnetization of polycrystalline MnZn ferrite with very low magnetic anisotropy

Magnetization processes of polycrystalline MnZn ferrite with very low magnetic anisotropy were investigated in the Rayleigh region. Complex permeability spectrum of polycrystalline MnZn ferrite has typically one dispersion. However, two dispersions in complex impedance spectrum from which complex permeability are calculated were observed. Topological and magnetostrictive investigations showed that domain wall motion and domain rotation are responsible for the two dispersions. Calculation of individual contributions of domain wall motion and domain rotation showed that both mechanisms play a significant role in the magnetization process of this material. The role of domain wall in magnetic loss was also discussed.