The Effects of Epigallocatechin-3-Gallate and Mechanical Stimulation on Osteogenic Differentiation of Human Mesenchymal Stem Cells: Individual or Synergistic Effects

This study aims to investigate the roles and effects of EGCG (epigallocatechin-3-gallate) during the osteogenic differentiation of human mesenchymal stem cells (hMSCs) in vitro. Recent studies have shown that proper mechanical stimuli can induce osteogenic differentiation of hMSCs apart from biochemical factors. In this study, the hMSC cultures were subjected to: (1) 25 uM EGCG alone or (2) 3% mechanical stretching (0.2 Hz for 4 h/day for 4 days) or (3) in combination with 3% mechanical stretching (0.2 Hz for 4 h/day for 4 days). The two factors were applied to the cell cultures separately and in combination to investigate the individual and synergistic effect of both mechanical stimulation and ECGC in the osteogenic differentiation of hMSCs. Utilizing real time PCR, we measured various osteogenic markers and even those related to intracellular signalings. Further investigation of mitochondria was performed that mitochondria biogenesis, antioxidant capacity, and morphological related markers were measured. hMSCs were to be osteogenic or myogenic differentiated when they were under 3% stretching only. However, when EGCG was applied along with stretching they were to be osteogenic differentiated rather than to be myogenic differentiated. This was supported by evaluating intracellular signalings: BMP-2 and VEGF. Therefore, the synergistical effects of simultaneous employment of stretching and EGCG on osteogenic differentiation were confirmed. Moreover, simultaneous employment was found positive in mitochondria biogenesis, antioxidant capacity, and morphological changes. Through this study, we came into the conclusion that the combination of proper mechanical stretching, 3% in this study, and EGCG promote osteogenic differentiation. Reflecting that EGCG can be obtained from plants not from the chemical syntheses, it is worth to be studied further either by animal tests or long-term experiments for clinical applications.

Dose-Volume Analysis of Lung and Heart according to Respiration in Breast Cancer Patients Treated with Breast Conserving Surgery / 한국유방암학회지

PURPOSE: Adjuvant radiotherapy of breast cancer using a photon tangential field incurs a risk of late heart and lung toxicity. The use of free breathing (FB), expiration breath hold (EBH), and deep inspiration breath hold (DIBH) during tangential breast radiotherapy as a means of reducing irradiated lung and heart volume was evaluated. METHODS: In 10 women with left-sided breast cancer (mean age, 44 years) post-operative computed tomography (CT) scanning was done under different respiratory conditions using FB, EBH, and DIBH in 3 CT scans. For each scan, an optimized radiotherapy plan was designed with 6 MV photon tangential fields encompassing the clinical target volume after breast-conserving surgery. RESULTS: The results of dose-volume histograms were compared using three breathing pattern techniques for the irradiated volume and dose to the heart. A significant reduction dose to the irradiated heart volume for the DIBH breathing technique was compared to FB and EBH breathing techniques (p<0.05). CONCLUSION: This study demonstrated that the irradiated heart volume can be significantly reduced in patients with left-sided breast cancer using the DIBH breathing technique for tangential radiotherapy.

Characterization of UV-irradiated dense/porous collagen membranes: morphology, enzymatic degradation, and mechanical properties

Collagen-based membranous materials of various shapes (gel, film, sponge) are known to be the most promising materials in terms of facilitating the regeneration of dermal defects. In this study, dense and porous collagen membranes were fabricated using air-drying and freeze-drying processes, respectively, and the effect of ultraviolet (UV) radiation on the degree of membrane crosslinking was evaluated by in vitro biodegradation and mechanical testing. A non-irradiated membrane group was used as the negative control and a glutaraldehyde (GA) treated group as the positive control. Scanning electron microscopy showed that, as the freezing temperature decreased to -196 degrees C, the resultant mean pore sizes also decreased; optimal pore size was obtained at a freezing temperature of -70 degrees C. In vitro biodegradation and mechanical testing demonstrated that GA treatment or 4 hours of exposure to UV radiation significantly increased both resistance to collagenase and mechanical strength versus the untreated controls, regardless of the collagen membrane type (dense or porous). Our results suggest that UV treatment is a useful tool for the fabrication of collagen membranes designed to be used as dermal dressings.

Follicle stimulating hormone receptor gene mutation in Korean women with premature ovarian failure and normal karyotype / 대한산부인과학회잡지

OBJECTIVE: To determine whether the follicle stimulating hormone(FSH) receptor gene mutation (C566T point mutation) is present in Korean women with premature ovarian failure and normal karyotype. METHODS: Genomic deoxyribonucleic acid(DNA) obtained from 40 patients with chromosomally competent premature ovarian failure and from 30 normal fertile women(control group) was amplified by polymerase chain reaction(PCR). PCR products were digested by the enzyme BsmI and polyacrylamide gel(PAG) elctrophoretic patterns of these enzyme-digested products were analyzed. The direct sequencing of PCR products was also performed. RESULTS: All patients with premature ovarian failure and 30 normal control women demonstrated homozygous, normal alleles with 51- and 27- base pairs fragments in PAG elctrophoresis. The absence of C566T point mutation in both group was confirmed by direct DNA sequencing. CONCLUSIONS: A C566T mutation in FSH receptor gene is rare in Korean women with premature ovarian failure and normal karyotype.

Carrier Detection and Prenatal Diagnosis of Hemophilia A in a Korean Population by Analysis of Two Variable Dinucleotide Tandem Repeats within the Factor VIII Gene / 대한산부인과학회잡지

We have undertaken this study to identify the usefulness of two variable dinucleotide tandem repeats within the factor VIII gene for carrier detection and prenatal diagnosis of hemophilia A in the Korean population. We have analyzed these polymorphisms in 50 unrelated Korean mothers of patients with severe hemophilia A, using polymerase chain reaction. The expected heterozygosity rates of the intron 13 and intron 22 dinucleotide repeats were 56% and 40%, respectively. Analysis of the intron 13 and intron 22 dinucleotide repeats revealed heterozygous patterns in 29(58%) and 17(34%) of 50 mothers studied, respectively. The combined overall informativity of the intron 13 and intron 22 dinucleotide repeats was 68%. Using linkage analysis with the intron 13 dinucleotide repeats, we have attempted three cases of carrier detection and two cases of prenatal diagnosis in two families of patients with severe hemophilia A. Two pregnant women were diagnosed as carriers, and the other patients as non-carrier Prenatal diagnosis revealed an unaffected male in one fetus, and an unaffected female in another fetus. This data demonstrated that the analysis of the intron 13 and intron 22 dinucleotide repeats very useful in the carrier detection and prenatal diagnosis of hemophilia A in the Korean population.