Byung Soo Chang

Histological analysis on the medieval mummy in Korea

Recently, there have been some reports on the mummies from the medieval tombs in Korea, which were not made on purpose. Although these mummies could be an invaluable source for the studies on the physical state of medieval Koreans, there were not any reports on this subject until now. In this study, we first tried to investigate the various tissues using light- and electron-microscopic techniques. In the organs we have examined, even though the collagen fibers were profusely found within all of them, some types of cells, such as red blood cells, chondrocytes, hepatocyte and muscle cells, were also visible in various tissues. The histological characteristics of the current case seemed to be well matched with the previous study in general even though there were also somewhat different findings from the previous reports on the mummies. Although the cause of the mummification in Korea was not completely explained, we think that the cause in this case could be correlated with cultural aspects--not with natural conditions--because the mummies were only found in cases where the lime-soil barrier was maintained until their discovery, and which separated the inner space of the coffins from the outer space. As similar cases are frequently reported nowadays, invaluable data on the physical status of the medieval Koreans could be attainable if systemic investigation could be performed on similar cases which are found in the future.

Radiological analysis on a mummy from a medieval tomb in Korea.

Although naturally mummified corpses have frequently been found in medieval tombs of Korea, there have been no scientific reports on the physical status of the mummies. In this study, we first tried to investigate the mummy using radiological methods. On physical examination, there were no findings suggestive of the cause of the death. From the radiological studies, we found that some internal organs were well preserved, while the bones showed similar appearances to those of living cases. From the stage of development of the teeth and carpal bones, the age of the mummy was estimated to be 4.5 to 6.6 years old. Although the exact cause of the mummification could not be clearly elucidated, it may be due to the lime-soil mixture outside the outer coffin, completely sealing the inner coffin from the outer spaces. In this study, as the mummy in the medieval tomb has proved to be well preserved over the last 400 years, similar cases could give invaluable clues to the physical status of medieval Koreans.

Preserved skin structure of a recently found fifteenth-century mummy in Daejeon, Korea

Recently published reports on Koreas medieval mummies have been regarded as an invaluable source for studies into the physical characteristics of medieval Koreans. However, even though the mummified tissues have been investigated histologically on various previous occasions, there are many unanswered questions relating to their tissue preservation. The aim of this study was to obtain new data on the ultramicroscopic characteristics of the mummified skin of a fifteenth‐century mummy found recently in Daejeon – one of the oldest ever found in Korea. Electron microscopy revealed that much of the epidermis had decayed; what remained of the dermis was filled with collagen fibres and melanin granules or invading bacterial spores present within the mummified epidermis. Considering the histological characteristics shared by naturally formed mummies in different parts of the world, we concluded that the ultramicroscopic patterns of the Daejeon mummy were more comparable with those naturally formed mummies than with artificially formed ones. This is the first full description of the morphological characteristics of the skin collected from this recently found medieval mummy from Daejeon, South Korea.

Endoscopic investigation of the internal organs of a 15th-century child mummy from Yangju, Korea.

Our previous reports on medieval mummies in Korea have provided information on their preservation status. Because invasive techniques cannot easily be applied when investigating such mummies, the need for non‐invasive techniques incurring minimal damage has increased among researchers. Therefore, we wished to confirm whether endoscopy, which has been used in non‐invasive and minimally invasive studies of mummies around the world, is an effective tool for study of Korean mummies as well. In conducting an endoscopic investigation on a 15th‐century child mummy, we found that well‐preserved internal organs remained within the thoracic, abdominal and cranial cavities. The internal organs – including the brain, spinal cord, lung, muscles, liver, heart, intestine, diaphragm and mesentery – were easily investigated by endoscopy. Even the stool of the mummy, which accidentally leaked into the abdominal cavity during an endoscopic biopsy, was clearly observed. In addition, unusual nodules were found on the surface of the intestines and liver. Our current study therefore showed that endoscopic observation could provide an invaluable tool for the palaeo‐pathological study of Korean mummies. This technique will continue to be used in the study of medieval mummy cases in the future.

Detection of antimicrobial substances from larvae of the black soldier fly, Hermetia illucens (Diptera: Stratiomyidae)

Maggots have become highly successful in the treatment of non‐healing wounds and multidrug‐resistant pathogen infections. The main objective of this study was to extract antibacterial substances from larvae of the black soldier fly, Hermetia illucens. To induce immune responses, we septically injured the larvae with a contaminated needle. Lyophilized H. illucens larvae were homogenized and extracted with acidic methanol. We examined the antifungal and antibacterial effects of the low molecular weight antimicrobial factors within the larval extract on the growth of a broad range of microorganisms, including Gram‐positive Staphylococcus aureus, methicillin resistant Staphylococcus aureus (MRSA), and Gram‐negative Pseudomonas aeruginosa. Furthermore, we isolated the anti‐MRSA substances from the larval extract using high performance liquid chromatography. These investigations revealed that the larval extract possessed a broad‐spectrum of antibacterial activity, demonstrating that secretions of H. illucens larvae prove useful in the fight against MRSA and can potentially be a source of novel antibiotic‐like compounds for infection control.

IKKβ-mediated inflammatory myeloid cell activation exacerbates experimental autoimmune encephalomyelitis by potentiating Th1/Th17 cell activation and compromising blood brain barrier

BackgroundThe inflammatory myeloid cell activation is one of the hallmarks of experimental autoimmune encephalomyelitis (EAE), yet the in vivo role of the inflammatory myeloid cell activation in EAE has not been clearly resolved. It is well-known that IKK/NF-κB is a key signaling pathway that regulates inflammatory myeloid activation.MethodsWe investigated the in vivo role of inflammatory myeloid cell activation in myelin oligodendrocyte glycoprotein (MOG) peptides-induced EAE using myeloid cell type-specific ikkβ gene conditional knockout-mice (LysM-Cre/IkkβF/F).ResultsIn our study, LysM-Cre/IkkβF/F mice had alleviated clinical signs of EAE corresponding to the decreased spinal demyelination, microglial activation, and immune cell infiltration in the spinal cord, compared to the wild-type mice (WT, IkkβF/F). Myeloid ikkβ gene deletion significantly reduced the percentage of CD4+/IFN-γ+ (Th1) and CD4+/IL-17+ (Th17) cells but increased the percentages of CD4+/CD25+/Foxp3+ (Treg) cells in the spinal cord and lymph nodes, corresponding to the altered mRNA expression of IFN-γ, IL-17, IL-23, and Foxp3 in the spinal cords of LysM-Cre/IkkβF/F EAE mice. Also, the beneficial effect of myeloid IKKβ deletion in EAE corresponded to the decreased permeability of the blood brain barrier (BBB).ConclusionsOur findings strongly suggest that IKK/NF-kB-induced myeloid cell activation exacerbates EAE by activating Th1 and Th17 responses and compromising the BBB. The development of NF-κB inhibitory agents with high efficacy through specific targeting of IKKβ in myeloid cells might be of therapeutic potential in MS and other autoimmune disorders.

The Presence of Megamitochondria in the Ellipsoid of Photoreceptor Inner Segment of the Zebrafish Retina

Although the megamitochondria (MM) were localized in various pathological conditions, normal retina of some mammalian species was reported to include MM for various physiological roles. However, it was not clearly confirmed whether the MM is present in the retina of lower vertebrate as well. In this study, we tried to show the presence of the MM in the zebrafish retina using electron microscopic technique. In all the photoreceptors including rods, cones and double cones of the zebrafish retina, MM were observed in the ellipsoid of inner segment. In the photoreceptor epllipsoid of the zebrafish retina, the mitochondria located in the central portion of the ellipsoid had a highly electron‐dense matrix, which were accompanied by the mitochondria with electron‐lucent matrix in the apical portion of the ellipsoid. The presence of MM was more clearly discernable in the rods, which were localized under the double cones. This finding is somewhat different from those observed in the previous studies because MM were localized in the inner segment of cones, but were not in those of rods in the case of mammalian retina. Although the exact physiological meaning for the presence of MM in some vertebrate species should be further studied, the present study could show that the MM in the ellipsoid of the retinal photoreceptors was not only restricted in some mammalian species.

Expression, cDNA cloning, and characterization of the antibacterial peptide cecropin D from Agrius convolvuli

Abstract Cecropins are basic antibacterial peptides that have potent activities against microorganisms. We have cloned and characterized a cecropin-like peptide of the lepidopteran insect Agrius convolvuli and analyzed its expression in Escherichia coli. The full-length cDNA of A. convolvuli cecropin D3 (AcCec) was 318 bp, containing a 5′ untranslated region (UTR) of 47 bp, a 3′ UTR of 82 bp with a poly (A) tail, and an open reading frame (ORF) of 189 bp encoding a polypeptide of 63 amino acids, including a 24 amino acid signal sequence and a 38 amino acid mature peptide (GenBank accession no. GQ888768). The mature peptide is highly similar to D-type cecropin. To understand the effect of C-terminal amidation, while overcoming the disadvantage of its lack in the prokaryote system, we added a lysine residue to AcCec (AcCec-K) and compared its antibacterial activity to the purified AcCec. The recombinant AcCec (rAcCec) and AcCec-K were expressed, respectively, in E. coli Rosetta cells using a pGEX-4T-1 expression vector, which contained the glutathione S-transferase (GST) gene for fusion partner, and the fusion proteins were induced by isopropyl-β-d-thiogalactopyranoside (IPTG). The recombinant proteins were purified by fast protein liquid chromatography (FPLC) using GSTrap FF and Resource RPC column. The result of the inhibition zone suggests that C-terminal lysine residue could increase the activity due to activated phosphorylation.

Spermatogenesis of Siamese Fighting Fish, Betta splendens, Osphronemidae, Teleostei

Taxonomically, Betta splendens, which is generally known as Siamese fighting fish belongs to the Osphronemidae. The common name ‘fighting fish’ came from their specific behaviors. When two males encounter each other in the same living place, typical pattern of aggressive behavior is occurred (Figler, 1972; Lobb & McCain, 1976). The labyrinth organ, which is situated on either side of the head in the gill cavity directly above the gills, allows Betta splendens to have ability to breathe atmospheric air (Bailey & Sandford, 1998). Generally, spermatogenesis of teleost varies depending on species and inhabited environments. The spermatogenesis of fish has been studied in some species, Liza aurata (Brusle, 1981), Salmo gairdnen (Billard, 1984), Acanthopagrus schlegeli (Gwo & Gwo, 1993), Boleophthalmus pectinirostris (Chung, 2008), Atlantic cod, Gadus morhua L. (Rebours & Ottesen, 2013) and Epinephelus bruneus (Kim et al., 2013). There are various studies about Betta splendens in relation to their aggressive behavioral responses (Thompson & Strum, 1965), intrasexual communications (Doutrelant et al., 2001), sex reversal (Pandian & Sheela, 1995), and development (Mabee & Trendler, 1996). Also, there is a study focusing on changes of testis followed by aging under light microscope (LM) (Woodhead, 1974). But there are few studies and limited information about spermatogenesis in ultrastructural approach of Betta splendens. Moreover, to increase understandings about hormonal effects regarding to their patterns of behaviors (Kirankumar & Pandian, 2002), it is necessary to investigate spermatogenesis of Betta splendens. Especially, in contrast to sperms of genus salmo and genus Oncorhynchus (Alfert, 1956) which spawn demersal eggs, settled under the water, sperms of Betta splendens spawn pelagic eggs which float on the water. The differences between each sperm spawning demersal and pelagic eggs, respectively, are expected regarding to spermatogenesis and Spermatogenesis of Siamese Fighting Fish, Betta splendens, Osphronemidae, Teleostei

Production and on-column re-folding of human vascular endothelial growth factor 165 in Escherichia coli

Vascular endothelial growth factors (VEGFs) are a family of proteins that promote angiogenesis and participate in a variety of physiological and pathological processes. In this work, the gene encoding the human VEGF isoform 165 (hVEGF165) was cloned into the expression vector pET32a (+) to construct a fusion expression plasmid that induced the thioredoxin (Trx) gene and transformed into Escherichia coli. The recombinant fusion protein TrxhVEGF165 was expressed optimally as inclusion bodies in the case of being cultivated for 4 h at 30°C and 1 mM IPTG concentration. The Trx-hVEGF165 was refolded and purified effectively from urea-solubilized inclusion bodies by the immobilized metal affinity chromatography. Released from the fusion protein by enterokinase cleavage and purified to homogeneity, the recombinant hVEGF165 (rhVEGF165) was biologically active as assessed by the human umbilicalvein endothelial cells (HUVECs) proliferation and the chicken chorioallantoic membrane (CAM) assay. The expression and in vitro refolding of rhVEGF165 resulted in production of an active molecule in a yield of 4.04 mg/L flask cultivation.