Background: A hip fracture may occur spontaneously prior to the hip impact, due to the muscle pulling force exceeding the strength of the femur.
Objects: We conducted falling experiments with humans to measure the activity of the hip muscles, and to examine how this was affected by the fall type.
Methods: Eighteen individuals fell and landed sideways on a mat, by mimicking video-captured real-life older adults’ falls. Falling trials were acquired with three fall directions: forward, backward, or sideways, and with three knee positions at the time of hip impact, where the landing side knee was free of constraint, or contacted the mat or the contralateral knee. During falls, the activities of the iliopsoas (Ilio), gluteus medius (Gmed), gluteus maximus (Gmax) and adductor longus (ADDL) muscles were recorded. Outcome variables included the time to onset, activity at the time of hip impact, and timing of the peak activity with respect to the time of hip impact.
Results: For Ilio, Gmed, Gmax, and ADDL, respectively, EMG onset averaged 292, 304, 350, and 248 ms after fall initiation. Timing of the peak activity averaged 106, 96, 84, and 180 ms prior to the hip impact, and activity at the time of hip impact averaged 72.3, 45.2, 64.3, and 63.4% of the peak activity. Furthermore, the outcome variables were associated with fall direction and/or knee position in all but the iliopsoas muscle.
Conclusion: Our results provide insights on the hip muscle activation during a fall, which may help to understand the potential injury mechanism of the spontaneous hip fracture.
모기는 현재까지 약 3500여 종이 알려져 있지만 이들 중에는 외형적으로 종 동정이 어려울 뿐만 아니라 생식적 격리가 완벽하지 않고 낮은 수준에서의 유전자 이입이 일어나고 있는 단발종(incipient species) 또한 존재하고 있다. 이러한 종에 대하여 분자적 수준에서 관련된 유전자 정보 및 미소부수체(microsatellites)를 통한 개체군간 유전적 형태를 분석하여 이들의 유전적 분화 정도를 알아보고자 한다. 이를 통해서 종 내에서의 변이 또는 근연종간 유전적 차이와 유전자 이입을 확인하여 연구 대상 종의 진화 과정을 설명하고자 한다. 이러한 자료와 이들의 생태 및 행동적 특징을 바탕으로 모기 방제 및 감염성 질병 전파 연구에 대한 기초 자료로 제공하고자 한다.
모기는 말라리아, 황열, 뎅기열, 웨스트나일열, 사상충, 치쿤구냐, 일본뇌염, 지카 등의 여러 질병을 매개하고 있고 자연적 요인과 인위적 요인에 의한 지구의 기후변화는 이들 병원성 매개모기들이 점점 더 번성하게 만드는 요인이 되고 있다. 현재 우리나라에서 주목해야 될 감염성 매개질병으로 말라리아와 뎅기열은 기후변화에 의한 기온 상승 요인으로 매개모기의 분포지역 확대와 함께 교통수단의 발달 및 국가 간 빈번한 교류에 의해서 유럽을 비롯한 오세아니아, 동아시아의 온대 지역에서도 감염자의 발생빈도 수가 최근 지속적으로 증가 추세를 보이고 있다. 따라서 기후변화 요인과 인간 활동 등에 의한 요인으로 감염 지역과 매개모기 분포가 미래 예측 불확실성과 복잡성을 가지고 있지만 국내 침입을 막기 위한 해외 유입 방지에 대한 지속적인 모니터링과 방제뿐만 아니라 국가 간 방제 프로그램 공조를 통한 모기에 의해 매개되는 질병 확산에 대비하는 것이 중요할 것으로 생각된다.
The Japanese oak silkmoth, Antheraea yamamai Guérin-Méneville 1861 (Lepidoptera: Saturniidae), is one of the important natural resources possessing industrial value for silk fiber production. In this study, ten microsatellite markers and two mitochondrial DNA (mtDNA) gene sequences (COI and ND4) were used to investigate the genetic variation and geographic structure of A. yamamai populations in South Korea. Two mtDNA gene sequences revealed very low total genetic variation and resultant low geographic variation, validating to use further variable molecular markers. Population-based FIS, FST, RST, and global Mantel test consistently support that A. yamamai populations are overall well interconnected with a relatively high gene flow. Nevertheless, STRUCTURE analysis using microsatellite data and mtDNA sequences coincidently indicate the presence of two genetic pools in many populations.
Screening for antimicrobial peptide genes in the immune-induced Antheraea yamamai larvae led to the identification of a novel antifungal moricin-like peptide (MLP10) gene. The complete MLP10 cDNA is comprised of 403 bp with 174 bp open reading frame encoding a 58 amino acid precursor that contains a putative 23-residue signal peptide, a 2-residue propeptide and a 33-residue mature peptide. The deduced amino acid sequence of MLP10 has 26∼52% identity to those of moricin-related peptides from lepidopteran insects. The MLP10 was highly expressed in E. coli BL21(DE3) by fusing with ketosteroid isomerase (KSI) to avoid the cell death during induction. The resulting expressed KSI-MLP10 fusion protein was in a insoluble form. Recombinant MLP10 was released by cleavage of the fusion protein with cyanogen bromide (CNBr). Subsequently, we purified pure active MLP10 by FPLC chromatography, and 5.2mg of MLP10 was obtained from 1L culture medium. The purified MLP10 was prevented the growth of candida albicans at 6.25 uM, and was also active against gram negative and gram positive bacteria. This potent antimicrobial activity suggests that MLP10 may play a role in the immune response of A. yamamai.
The antibiotic peptide PAJE (RWKIFKKPFKISIHL-NH2), designed incorporating the N-terminal α-helical segments of papiliocin and jelleine, is a 15-residue hybrid peptide that has a broad spectrum of activity against Gram-negative, positive bacteria and fungi. In this study, we successfully expressed bioactive PAJE in Escherichia coli cells that are highly sensitive to this peptide. For the efficient production of peptide, we synthesized gene encoding PAJE, and fused the sequence in-frame to ketosteroid isomerase (KSI) gene to construct an expression vector pET29b-PAJE-KSI, which was then used to transform E. coli BL21 (DE3). The fusion protein PAJE-KSI was expressed as inclusion body at high level (more than 30% of the total proteins). Recombinant PAJE was easily released by cleavage of the fusion protein with cyanogen bromide (CNBr). Subsequently, we purified the recombinant PAJE by FPLC chromatography. The purified PAJE displayed considerably antibacterial activity identical to that previously reported for chemically synthesized PAJE. The results indicated that successful expression of PAJE in E. coli cells and efficient procedure for purification may lead to a cost-effective platform for the mass production of PAJE.
Disulfide bond formation, reduction and isomerization are important posttranslational modification in proteins that occur in most, if not all, living organisms. In eukatoyes, disulfide bond in substrate proteins are primarily formes by ERO1 and PDI. ERO1, oxidized by molecular oxygen, acts as a specific oxidant of PDI, which then makes disulfide bonds in folding proteins oxidized directly. It means that ERO1 plays an essential role in setting the redox potential in the ER, and the regulation of Ero1p activity is critical to maintain redox homeostasis and proper ER folding activity. We have isolated and analysed a endoplasmic reticulum oxidoreductase (ERO1) from Bombye mori. It apperas that both an N-terminal CxxxxC motif and a C-terminl CxxCxxC motif are necessary for Ero1p fuction. In vivo, the result of the 5day of 5th instar larvae by RT-PCR and Real-Time PCR shows that posterior silkgland, skin and mid silkgland are revealed more than rhose of other tissues. The same result for tissue distribution of transcripts is appeared about ERO1 and PDI. In Bombyx mori, ERO1 is also supposed to correlate with PDI. Afterwards, more experiments are needed to figure out accurate interrelation between ERO1 and PDI.
Recently Transgenesis was achieved in Bombix mori. For stable and effective transgenesis in B.mori, B.mori cytoplasmic actin gene (BmA3) promoter was used to expression of marker gene, the green fluorescent protein(GFP). Green fluorescent protein expression for selection of transformants was visible in all larval, pupal, and adult tissues but, unexpectdly, was not detectable in embryos. So, it spend times and money on rearing of silkworm. Furthermore, the BmA3 promoter is predominantly active in the midgut, which makes it difficult to reliably identify transformants since autofluorescence of many insect foods can mask low-level fluorescence and only allows the detection of strongly expressing individuals with potentially multiple insertions. Therefore, we need more intensely promoter than BmA3 promoter for selected by expression of GFP in embryos and selected by reliable expression of GFP in larvae. We performed dot blot hybridization to develop strong promoter. Nine differentially expressed clones were isolated and we focused one clone of them which has high similarity with heat shock protein 70 gene from D.melanogaster. We named it as bHSP70 (Bombyx mori heat shock protein 70). Expression from the hsp70 promoter was strong and heat shock-dependent. And Drosophila hsp70 promoter appears useful for regulating expression of Exogenous DNA. So, we analyzed transcriptional activity of promoter with bHSP70 gene by using dual luciferase assay system. bHSP70 promoter has about 264 folds more intensely than BmA3 promoter. Also, when bHSP70 promoter treated heat shock(42℃), transcriptional activity incresed 2 times more than normal condition. Therefore, we suggest that bHSP70 promoter is more effective candidate for stable transformation and selection of transformants.
Peptidyl prolyl cis/trans isomerases (PPIases) catalyze the slow cis/trans isomeraization of proline peptide (Xaa-Pro) bonds in oligopeptides and accelerates slow, rate-limiting steps in the folding of several proteins. We studied the characterization of Cyclophilin A (bCyp A) isolated from Bombyx mori . The cDNA of bCyp A is 947 bp. There is a 5´-untranslated region of 91 nucleotides followed by an initiating ATG codon. The TAA termination codon occurs at nucleotide 588. Thus translation of the sequence from nucleotides 91 to 588 would produce a protein of 166 amino acids with a calculated molecular mass of 18.2kDa. The 'AATAAA' consensus polyadenylation signal and poly A tail are present in the 3´-untranslated region. To analysis of PPIase activity, we expressed the bCyp A protein in Sf9 cell by using baculovirus expression vector system (BEVS). SDS-PAGE and Western blot analysis showed that the molecular weights of intracelluar expressed protein was approximately 28.2 kDa. The PPIase activity assay was monitored by proteolytic cleavage of the chromophore p-nitroanilide byα-chymotrypsin. As substrate the synthetic tetrapeptide succinyl-Ala-Ala- Pro-Phe-p-nitroanilide was used.
The insect baculovirus expression vector system (BEVS) is useful for the production of biologically active recombinant proteins. However, the overexpression of foreign proteins in this system often results in misfolded proteins and the formation of protein aggregates. To overcome this limitation, we have developed a versatile baculovirus expression and secretion system using the Bombyx mori protein disulfide isomerase (bPDI) as a fusion partner. bPDI gene fusion improved the secretion and antibacterial activity of recombinant nuecin proteins. Thus, bPDI gene fusion is a useful addition to the BEVS for the large-scale production of bioactive recombinant proteins.