Biomedical subjects

Dong Hoon Shin

Publications and source records attributed to Dong Hoon Shin.

44 records · Page 3Linked to original sources

PubMed2003

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.

Age Determination by Skeleton↗

PubMed2003

Microglial phagocytosis of dopamine neurons at early phases of apoptosis.

Transection of the medial forebrain bundle caused apoptosis of dopamine neurons in the rat substantia nigra. Immunohistochemical localization of activated microglia and tyrosine hydroxylase in the axotomized substantia nigra showed that activation of microglia was rapid and OX-6 (MHC-II marker)-positive and ED1 (lysosomal phagocytic marker)-positive microglia were apposed to structurally intact tyrosine hydroxylase-positive dopamine neurons, indicating microglial phagocytosis of degenerating dopamine neurons. The occurrence of microglial phagocytosis at early stages of apoptosis may indicate the evolution of apoptosis into an irreversible state. Alternatively, interventions that suppress early activation of microglia might lead to novel mechanisms for neuron protection.

Animals↗

PubMed2003

Ultramicroscopical immunolocalization of PAX6 in the adult chicken retina.

Cell type-specific PAX6 protein expression was examined in all retinal layers of the normal chicken retina. The most intense PAX6 immunostaining was found in the ganglion cell and inner nuclear layers, and in lower amounts in the optic nerve fiber, the inner plexiform and the photoreceptor layers. PAX6 immunostaining was variable in terms of its subcellular localization, even within one cell. PAX6 immunostaining was mainly localized in nuclear heterochromatin of the ganglion cell and inner nuclear layers whereas in the outer nuclear layer, PAX6 immunostaining was only observed in the intercellular space and the cytoplasm. In photoreceptors, the myoid portion of the inner segment showed PAX6 immunostaining, but the ellipsoid portion and the outer segment did not. The ultrastructural distribution pattern of PAX6 in the adult chicken retina suggests that normal expression of PAX6 is variable even in subcellular structures in the same cell type.

Animals↗

PubMed2003

Clinical features of Plasmodium vivax malaria.

BACKGROUND: Since its reemergence in 1993, a number of cases of Plasmodium vivax malaria have been reported in Korea. We analyzed the cases of malaria patients living in Chuncheon and its neighboring communities, to characterize its clinical manifestations and laboratory findings, and to identify any differences between our clinical findings and those of previous studies. METHODS: We reviewed the clinical records of cases that were confirmed as malaria by peripheral blood smear at Chuncheon Sacred Heart Hospital from July 1998 to September 2001. RESULTS: Forty-four cases were included in the study. All patients were infected with Plasmodium vivax, and presented with high fever; however, tertian fever developed in only 15 patients (35.7%). A number of cases showed various symptoms, which included headache, abdominal pain, nausea and vomiting. Of the 44 cases identified, 41 (93.2%) developed malaria between June and September. Thrombocytopenia was a prominent finding in 75% of the cases at diagnosis, but resolved during or after therapy. Other laboratory abnormalities such as, anemia, elevated transamines, coagulopathies, and elevated lactose dehydrogenase (LDH) were also noted. Cerebrospinal fluid (CSF) studies were performed in five cases, one of which showed pleocytosis in the CSF. CONCLUSION: We noted only 15 patients (35.7%) with tertian fever; the other patients showed variable fever patterns. Thrombocytopenia was the most prominent laboratory finding. Therefore, we suggest that malaria should be included in the differential diagnosis of febrile diseases with an onset between June to and September, regardless of the pattern of the fever.

Adult↗

PubMed2002

Fas ligand mRNA expression in the mouse central nervous system.

Fas ligand (FasL) expressing cells delete Fas bearing T cells, thereby enabling privileged immune status in the brain. Although the presence of FasL immunoreactivity has been shown in various cell types in the central nervous system, the precise in vivo distribution of FasL mRNA in mammals is not known. Accordingly, we localized intense FasL mRNA signals in neuroglial cells mainly within the white matter regions. Using a combined labeling technique of immunocytochemistry and in situ hybridization, we confirmed that FasL signals were due to neuroglial cells rather than neurons. This study shows that FasL mRNA is constitutively expressed in the normal mouse brain, and suggests that the Fas/FasL system protects the CNS from immunological damage.

Animals↗

PubMed2002

Biochemical properties of polysaccharides from black pepper.

The purified polysaccharides from Piper nigrum were prepared as follows: a hot water extract of pepper seeds was fractionated by ultrafiltration with a 5-kDa-membrane cartridge. A fraction with 5 kDa or bigger molecules was successively purified by open column chromatography on DEAE-Toyopearl 650C and Bio-gel P-60 with each active fraction, resulting in PN-Ib and PN-IIa, purified anti-complementary polysaccharides. None of the anti-complementary activity of any polysaccharide was changed by pronase digestion or polymyxin B treatment, but they were decreased by periodate oxidation. Analysis of component sugar and molecular mass determination of the anti-complementary polysaccharides indicated that PN-Ib with an average molecular mass of 21 kDa contained 88.5% glucose and other negligible minor monosaccharides, while PN-IIa showed a different monosaccharide composition, which contained a significant proportion of galactose, arabinose, galacturonic acid and rhamnose. The molar ratio of galactose and arabinose of PN-IIa (48 kDa) was 1.93:1. PN-1 did not react with beta-glucosyl Yariv reagent, however, PN-IIa did react, which indicated that PN-IIa might be an arabinogalactan. Based upon these results, the usefulness of purified anti-complementary polysaccharides from Piper nigrum is suggested as a supplement for immune enhancement.

Piper nigrum↗

PubMed2002

In vitro and in vivo effects of macrophage-stimulatory polysaccharide from leaves of Perilla frutescens var. crispa.

The crude polysaccharide (PFB-1) was isolated from the leaves of Perilla frutescens var. crispa by the sequential procedures with hot-water extraction, methanol reflux, and ethanol precipitation. It was further purified by anion column chromatography in order to obtain the partially purified polysaccharide (PFB-1-0). In the presence of PFB-1-0, strong cellular lysosomal enzyme activity of murine peritoneal macrophages was observed in vitro. Compared to bacterial lipopolysaccharide (LPS), its activity was relatively high. The in vitro phagocytic activity was enhanced by PFB-1-0 as the similar pattern in both gram-negative bacteria, E. coli, and gram-positive bacteria, S. aureus with a time-dependent manner. We also investigated the production of several mediators by murine peritoneal macrophages upon stimulation with PFB-1 (in vivo) or PFB-1-0 (in vitro). The levels of nitric oxide (NO) and tumor necrosis factor (TNF)-alpha were increased in the presence of PFB-1-0 in vitro. The PFB-1 stimulated the production of interleukin (IL)-6 and granulocyte-macrophage colony-stimulating factor (GM-CSF) in vivo. Results suggest that the polysaccharide from P. frutescens var. crispa represents an immunopotentiator and biological response modifiers in vitro and in vivo levels.

Granulocyte-Macrophage Colony-Stimulating Factor↗

PubMedDate not supplied

Antioxidative and anti-diabetic effects of amaranth (Amaranthus esculantus) in streptozotocin-induced diabetic rats.

The anti-diabetic and antioxidative effect of amaranth grain (AG) and its oil fraction (AO) was studied in streptozotocin-induced diabetic rats. Male Sprague-Dawley rats were divided into four groups after induction of STZ-diabetes: normal control; diabetic control; diabetic-AG supplement (500 g kg(-1) diet); diabetic-AO supplement (100 g kg(-1) diet) and fed experimental diets for 3 weeks. Serum glucose, insulin, activities of serum marker enzymes of liver function and liver cytosolic antioxidant enzymes were measured. The AG and AO supplement significantly decreased the serum glucose and increased serum insulin level in diabetic rats. Serum concentration of liver function marker enzymes, GOT and GPT, were also normalized by AG and AO treatment in diabetic rats. Liver cytosolic SOD and GSH-reductase activities were significantly increased, and catalase, peroxidase and GSH-Px activities were decreased in diabetic rats. AG and AO supplement reverted the antioxidant enzyme activities to near normal values. Hepatic lipid peroxide product was significantly higher, and GSH content was decreased in diabetic rats. However, AG and AO supplement normalized these values. Our data suggest that AG and AO supplement, as an antioxidant therapy, may be beneficial for correcting hyperglycaemia and preventing diabetic complications.

Amaranthus↗