Biomedical subjects

Jaehyup Kim

Publications and source records attributed to Jaehyup Kim.

11 recordsLinked to original sources

PubMed2006

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.

Burial↗

PubMed2005

Immunohistochemical study on the distribution of sodium-dependent vitamin C transporters in the respiratory system of adult rat.

As vitamin C (L-ascorbic acid, VC) is known to be essential for many enzymatic reactions, the study on the transport mechanism of VC through cytoplasmic membrane is crucial to understanding physiological role of VC in cells and the respiratory system. In this regard, the study on the newly identified sodium-dependent VC transporters (SVCTs), SVCT1 and SVCT2, is required in organs that contain high concentration of VC. We have shown the distribution of SVCT proteins in the respiratory system, which has been reported to be one of the organs with a high concentration of VC, using immunohistochemical techniques. In the present study, intense SVCT immunoreactivities (IRs) were mainly localized in the respiratory system epithelial cells. In the trachea, both SVCT1 and 2 were localized in the psuedostratified ciliated columnar epithelium. In the terminal bronchiole, SVCT1 and 2 IRs were mainly observed in the apical portion of the simple columnar epithelium. In addition, SVCT IRs was localized within the cell membrane of some alveolar cells, even though we could not identify the exact cell types. These results provide the first evidence that intense SVCT1 and 2 IRs were found in the apical portion of the respiratory epithelial cells, suggesting that SVCT proteins in the apical portion could transport the reduced form of VC included in the airway surface liquid into the respiratory epithelial cells.

Animals↗

PubMed2005

Ultramicroscopic observations on morphological changes in hair during 25 years of weathering.

Weathering or long-term burial may cause profound morphological and histological changes in hair, which may affect the results of forensic and archaeological investigations. We therefore used ultramicroscopic techniques to assay the changes in weathering hair shafts caused by burial for up to 25 years. We found that the middle portion of hair shafts from living individuals shows the expected histological hair structure, while the cuticle layer was absent from the terminal portion of the same hairs, which may be due to the increased weathering experienced by the terminal portion. In hair samples taken 5 years after death, no significant changes in morphology were observed. By 15 years after death, however, we observed losses in various layers of the hair, including the cuticle layer. At 25 years after death, hair shafts showed a number of pores extending into the medulla, with only some hair shafts retaining their cortical layers. To our knowledge, this is the first ultramicroscopic study on weathering of hair for up to 25 years after death. Our results may therefore provide a basis for similar studies in the fields of forensic science and physical anthropology.

Burial↗

PubMed2005

An ultramicroscopic study on the distribution of Müller cell processes in the outer retinal layers of the zebrafish.

The zebrafish, Brachydanio rerio, is a good model for studying the development of various organs. We have assayed the distribution pattern of Müller cell processes in zebrafish retinas by electron microscopy. In the outer nuclear (ON) layer, multiple layers of Müller cell processes were present along both sides of the large pyramidal endings of the synaptic terminals. We found that the inner segments (ISs) of the zebrafish photoreceptors (PRs), including the cones, double cones and rods, were arranged in different planes, and that the Müller cell processes formed multilayered sheaths around virtually all PR compartments except their outer segments. Thus, Müller cell processes beyond the outer limiting membrane (OLM) are more easily observed in zebrafish retina than in the retinas of other species. To our knowledge, this is the first study to show the exact ultrastructural distribution of Müller cell processes around the OLM and the PR layer in zebrafish retina.

Animals↗

PubMed2004

Distribution of heat shock protein 108 mRNA during the development of the chicken brain.

The developmental expression of heat shock protein 108 (HSP108) mRNA was mapped in chicken brain using in situ hybridization and reverse transcription-polymerase chain reaction (RT-PCR). RT-PCR showed that HSP108 mRNA increased from embryonic day 5 (E5) to 13 (E13), significantly decreased from E17 to E21 and then increased again at the adult stage. In situ hybridization showed that while intense HSP108 positive (HSP108+) signals were localized in the cerebellum from E7 to E14, the intensities of these signals were significantly decreased at E17. However, at the adult stage, HSP108 expression increased in a cell type dependent manner. A decrease in HSP108 mRNA expression during differentiation was also observed in an in vitro study of brain cells treated with nerve growth factor (NGF).

Age Factors↗

PubMed2004

Protective effect of growth hormone on neuronal apoptosis after hypoxia-ischemia in the neonatal rat brain.

Recent studies have shown that growth hormone (GH) can reduce neuronal loss after hypoxic-ischemic injury (HI) in neonatal and juvenile rat brains. Here, we investigated whether GH exerts its neuroprotective role through an anti-apoptotic effect in neonatal rat brains damaged by severe HI. Gross and histological observations showed that the extent of brain damage was found to be reduced in GH-treated brain at E7 after injury. In a terminal transferase-mediated dUTP nick-end-labeling (TUNEL) study, TUNEL-positive apoptotic cells were localized only at the damaged region in animals treated with saline, which was confirmed by an electron microscopy. In an immunohistochemical study with anti-bcl-2, -bax, -bad, -neuronal nitric oxide synthase (nNOS), -inducible NOS (iNOS) and -endothelial NOS (eNOS) antibodies, we observed that bax, bad, iNOS and eNOS were elevated in the saline-treated group. This study thus suggests that the protective role of GH against HI injury is mediated thorough an anti-apoptotic effect, which offers the possibility of a GH application for the treatment of neonatal HI encephalopathy.

Animals↗

PubMed2003

Immunocytochemical study on the distribution of c-myb in the central nervous system of the transgenic mice expressing a human copper/zinc superoxide dismutase mutation.

Although our previous study showed the constitutive expression of c-myb in neurons, suggesting that this gene might be involved in the normal function of these cells, there were no reports on the expression pattern of c-myb under pathological conditions. In the present study, we first investigated the changes in c-myb immunoreactivities (IRs) in the central nervous system of the transgenic mice expressing a human copper/zinc superoxide dismutase (Cu/Zn SOD) mutation. The distribution of c-myb was enhanced in the various brain regions of transgenic mice expressing a mutated human Cu/Zn SOD gene. Immunohistochemistry showed intensely stained c-myb IR glial cells with the appearance of astrocytes within the various brain regions of transgenic mice such as the gray matter of the midbrain, medulla oblongata and spinal cord. Even though the exact functions of c-myb in the normal and pathological states were not clearly revealed until now, we think that the increase in c-myb expression in the mutant mice could be due to the compensate mechanism of the astrocytes for the reduced defence against superoxide toxicity because the only known function of c-myb was its correlation with the prevention of programmed cell death, which could be deduced from the previous studies.

Animals↗

PubMed2003

Vasoactive intestinal peptide (VIP) and VIP mRNA decrease in the cerebral cortex of nNOS knock-out(-/-) mice.

Although there is much evidence showing that NO regulates the release of VIP in several areas, there is no report about the influence of NO on VIP in the cerebral cortex. We therefore examined changes in VIP expression in the cerebral cortex of nNOS knock-out(-/-) mice using immunohistochemistry and in situ hybridization. The nNOS((-/-)) mice had significantly fewer VIP-immunoreactive neurons than the control mice and the VIP mRNA as well as the VIP-immunoreactivity of the individual neuron was decreased in the nNOS((-/-)) mice. The first demonstration of decrease in VIP expression in the cerebral cortex of nNOS((-/-)) mice may provide useful data for investigating the relation between NO and VIP in the cerebral cortex and the mechanisms of many functions of these two neurotransmitters.

Animals↗

PubMed2003

Heat shock protein 108 mRNA expression during chicken retina development.

In a developmental study on the expression of heat shock protein 108 (HSP108) mRNA in the chicken retina, we found different spatial and temporal expressions of HSP108 mRNA in each retinal layer. While intense HSP108 signals were found in the retina neuroblast layer at embryonic day 5 (E5), the ganglion cell population (GC), inner nuclear layer (IN) and pigment epithelium (PE) showed HSP108 expression at E9. At E14, HSP108 signals were reduced versus the previous stages even though signals were still detected in the GC, the IN, the outer nuclear layer and the PE. HSP108 signals were still detectable at the E21 stage, although each retinal layer showed a much differentiated morphology and diminished signal intensity. These results suggest that HSP108 expression might be developmentally regulated throughout eye organogenesis and that it plays a role in ocular development.

Animals↗

PubMed2003

The correspondence between the labeling patterns of antibody RT97, neurofilaments, microtubule associated protein 1B and tau varies with cell types and development stages of chicken retina.

The correspondence between the labeling patterns of antibody RT97, neurofilaments (NF-M and NF-H), microtubule associated protein 1B (MAP1B) and tau, were studied in the developing chicken. At embryonic day 3 (E3), intense RT97 immunoreactivity (IR) was found to be localized in cells in the region adjacent to the intraretinal space, which separates the inner and outer layers of the optic cup, and this was sustained at E8. However, this pattern changed dramatically at E12, as the intensities of RT97 IR increased in the inner retinal layer, while the outermost layers showed only weak IR. The adult stage retina showed RT97 IR within the nerve fibers of the ganglion cells, the processes of the amacrine cells and the photoreceptors. Additional immunostainings for NF-M, -H, MAP1B and tau showed that the observed changes in RT97 IRs were due to the different expressions of these proteins at different development stages.

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↗