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Biomedical subjects

S H Song

Publications and source records attributed to S H Song.

At least 37 records · Page 2Linked to original sources
PubMed1999

The coexistence of calcitonin gene-related peptide and substance P in pericellular arborization and satellite cell of goat trigeminal and nodose ganglia.

Pericellular arborization is reported to be the self-regulating structure in sensory ganglia. Although the calcitonin gene-related peptide (CGRP) or substance P (SP) immunoreactive pericellular arborization appeared in the sensory ganglia, there was no available information that CGRP and SP colocalize in this structure. As the attempts to resolve the question described above, the present study was undertaken to identify the coexistence of CGRP and SP in pericellular arborizations of the goat nodose and trigeminal ganglia by double immunohistochemistry. As the results show, CGRP immunoreactivity was present in every pericellular arborization containing SP immunoreactivity in trigeminal ganglia, however, pericellular network containing CGRP or SP immunoreactivity was not present in nodose ganglia. Unexpectedly, a few small satellite elements were observed to contain intense CGRP and SP immunoreactivity at the periphery of CGRP and SP immunoreactive neurones in nodose ganglia. Therefore, these results suggest that CGRP and SP coexist in pericellular arborizations, and that satellite cell as well as pericellular arborization may be involved in intraganglionic regulation of goat sensory ganglia.

Animals↗
PubMed1999

Modulation of renal xanthine oxidoreductase in aging: gene expression and reactive oxygen species generation.

Xanthine oxidoreductase (XD: xanthine dehydrogenase + xanthine oxidase) is a complex enzyme that catalyzes oxidation of hypoxathine to xanthine, subsequently producing uric acid. The enzyme complex exists in separate but interconvertible forms, xanthine dehydrogenase (XDH) and xanthine oxidase (XOD). XOD is one of the major cellular sources of superoxide production and is well known as a causative factor in ischemia/reperfusion damage. At present, almost no information on the conversion status is available with respect to aging. In the present study, we investigated the effect of age on the XOD/XDH status and gene expression in the kidney. In addition, we assessed XOD-induced reactive oxygen species (ROS) using the dichlorofluoroscein (DCF) method. Our results show that XD activity gradually up to 18 months of age and then a slight decrease at 24 months of age. XDH activity showed increases up to 18 months of age, then decreased at 24 months of age. The conversion of XDH to XOD, assessed by changes in the ratios of XOD/(XOD+XDH), showed an age-related increase, which peaked at 24 months. Levels of XD protein and its mRNA paralleled to overall XD activity. ROS generation has tendency to increase with age. Our results suggest that the increased conversion of XDH to XOD observed with age may be an important contributing factor to the increased renal oxidative stress during aging.

Aging↗
PubMed1998

Vestibular schwannoma with repeated intratumoral hemorrhage.

A symptomatic hemorrhage from a vestibular schwannoma is extremely rare, despite its relatively high incidence in the cerebellopontine angle. Much more unusual are repeated intratumoral hemorrhages. The authors report on such a rare case of repeated intratumoral hemorrhage from a vestibular schwannoma, presenting with sudden exacerbation of headache, nausea and vomiting. This second hemorrhage was confirmed by CT scan on the day of the onset of symptomatic exacerbation, which was 9 days after the initial CT scan, showing an enlarged amount of blood within the tumor. The MRI scan confirmed this CT finding. After removal, the tumor proved to be a typical vestibular schwannoma of mixed Antoni types A and B. Thin-dilated vessels with hemorrhage and hemosiderin-laden macrophages were observed. The patient's postoperative course was uneventful. A total of 28 reported cases of a single intratumoral hemorrhage in vestibular schwannomas, and one reported case of repeated hemorrhage are reviewed.

Adult↗
PubMed1998

Hypoplastic anaemia complicating myxoedema coma.

The case of a 68 year old women presenting in myxoedema coma is described. She was found to be anaemic with a haemoglobin of 8.2 g/dl. Further investigations showed a pancytopenia and a hypoplastic anaemia confirmed by bone marrow. The patient recovered and became euthyroid following initial treatment with intravenous tri-iodothyronine (T3) and later oral thyroxine (T4) replacement with resolution of pancytopenia and return of bone marrow to normal.

Aged↗
PubMed1998

Evidence that a beta-1,4-endoglucanase secreted by Acetobacter xylinum plays an essential role for the formation of cellulose fiber.

Cellulose-producing Acetobacter xylinum has been known to secrete a cellulose-hydrolyzing beta-1,4-endoglucanase (CMCax). When antibodies to recombinant CMCax were added to the culture medium, the formation of cellulose fiber was severely inhibited. Western blot analysis using the antibody showed that this enzyme was secreted into the medium even by a cellulose non-producing strain (Cel-). These results indicate that beta-1,4-endoglucanase in the medium plays a critical role in the formation of cellulose fiber by the microorganism.

Blotting, Western↗
PubMed1998

Surface features of human aortic atherosclerosis as seen with scanning electron microscopy.

Using SEM, we have observed surface structures of atherosclerotic lesions of human aortas obtained from autopsies ranging from 59 to 84 years of age (5 males and 4 females). We have found four major interesting features on the lumenal surface of the aortas: 1) blood cells including leukocytes adhering to the endothelial surface, 2) a de-endothelialized surface showing both elastogenesis and elastolysis, 3) abundant cholesterol-ester crystals in extracellular spaces, and 4) cave-like structures possibly suggesting new capillarization in the thrombotic atherosclerotic plaques. We concluded that SEM has a great value in revealing more interesting surface structures if morphological studies are previously done in detail so that the characteristic shapes can be identified, and perhaps then meaningful interpretations can be made on the mechanism of human atherogenesis.

Aged↗
PubMed1997

Outcome of pediatric patients with severe brain injury in Korea: a comparison with reports in the west.

There have been relatively wide variations in the results of studies examining the outcomes of severe brain injury in children. Among the reasons for these variations in outcome, prehospital care can be considered as one of the factors. In Korea, major hospitals use an aggressive and sophisticated management policy very similar to that practiced in the West. However, effective prehospital management, such as emergency care at the scene of injury and during transport by paramedics, have not yet been established. In order to evaluate the influence of prehospital care on the outcome in severely brain-injured children, we report the outcome recorded in 73 pediatric patients treated in our hospital following severe brain injury and compare these results with those reported from centers in the western community, where well-trained paramedic care and an excellent transfer system are in operation. The overall mortality rate in our patients was 23%; 41% had a good recovery, 22% moderate disability, and 12% severe disability, and 1% remained in a vegetative state. In conclusion, we would like to suggest that prehospital care does not remarkably influence mortality rates in severely brain-injured children.

Adolescent↗
PubMed1997

Prevalence of childhood asthma based on questionnaires and methacholine bronchial provocation test in Korea.

BACKGROUND: In most epidemiological survey studies, only subjective symptoms and past medical history of asthma have been used as diagnostic criteria. Even though a questionnaire survey can be performed in a large population study at low cost, limitations such as lack of objectivity and poor predictability in non-specific bronchial hyperresponsiveness cannot be avoided. OBJECTIVES: The purpose of this study was to elucidate the prevalence of current asthma based on questionnaires and methacholine bronchial provocation test, and the prevalence of atopy in Korea. METHODS: We performed modified ATS respiratory questionnaires and allergen skin-prick test with 10 common inhalant allergens among 3219 subjects aged 7-19 years in Seoul and a rural part of a small city, Chungju in Korea. Methacholine bronchial provocation tests were also performed among those who had asthma symptoms according to the questionnaire. The criteria of asthma was presence of both asthma symptoms and non-specific bronchial hyperresponsiveness. Atopy was defined as when an allergen induced weal size is same or larger than that caused by histamine. RESULTS: The prevalence of asthma based on questionnaires and methacholine bronchial provocation tests was 4.6%, while the prevalence of wheeze was 8.2% and 19.3% of total population complained of one or more respiratory symptoms related to asthma on the questionnaires. There was no significant difference according to age, sex and living area. The mean prevalence of atopy was 35.0% and the most common allergens were Dermatophagoides farinae (30.9%), Dermatophagoides pteronyssinus (27.5%), cat fur (20.4%) and cockroach (11.8%). The atopy prevalence in Chungju area was higher than that in Seoul and males showed a higher prevalence than females. The asthma prevalence was higher among atopics (6.8%) than among non-atopics (2.7%). None of questionnaire items were enough to predict the presence of bronchial hyperresponsiveness in terms of sensitivity, specificity and positive predictive value. CONCLUSION: The prevalence rate of current asthma in Korea was 4.6% and the prevalence rate of atopy in Korea was 35.0%. Questionnaire-based surveys are not enough to predict the actual prevalence of asthma.

Adolescent↗
PubMed1994

Three dimensional structures of pulmonary elastin; airway vs vascular elastin.

Elastin is known to occur in the lung parenchyma and pleura as well as in the pulmonary vessels, but no detailed studies of this elastin's linkage between them have been done in three dimensions. For many years we have known that there is abundant elastin in the mammalian lungs, which may be associated with etiology of causing emphysema. We have developed selective casting methods to allow us to determine the location where elastin is found morphologically. The method involves casting either the vasculature via the right ventricle, or the airways via the trachea in the air sacs. Studies of the vasculature were done with the lung inflated to 80% of the vital capacity. The casted lungs were then put in 0.1 N NaOH at 75 degrees C for 48 hours, turning them frequently. THis method removed all non-elastin tissues. The scanning electron microscopy (SEM) was used to reveal the three dimensional pictures of elastin structures from both lung parenchyma and pulmonary vessels. Elastin was seen as fenestrated sheets and some fibers in both the vessels and the airways. Elastin in the two different locations was often interconnected. Studies on 6 dogs, 8 rabbits, and 2 pigs showed no significant species difference at the level of resolution of the SEM, which was used to study the specimens after they had been freeze-dried.

Animals↗
PubMed1994

Variations in strength of the porcine aorta as a function of location.

Dissecting aneurysms split the wall of the aorta and other large arteries to create a false lumen in parallel with the true lumen. Experiments were designed to determine the pressure required to tear the media and the work required per unit area to propagate the dissection once it started. India ink was injected into the media of 17 opened porcine aortas through a needle inserted parallel to the lumen of opened aortas placed in a saline bath. The ink was infused at 0.9 ml/min with a constant infusion pump as the pressure was monitored with a pressure transducer. The size of the bleb formed by the ink in the media was recorded with a video camera mounted perpendicular to the lumenal surface. All data were recorded on a computer. The pressure-volume curve was used to obtain the distensibility of the media (the upslope), the peak pressure, the tearing pressure, and the work of dissection (the area under the P-V curve once tearing occurred). The projected area of the bleb was calculated from the video images, and the work/area was calculated. The peak pressures were always extremely high, and ranged from 634 +/- 204 (SD) mmHg for the lower abdominal aorta to 816 +/- 145 mmHg for the lower thoracic aorta. The work/area ranged from 1.88 +/- 0.89 mJ/cm2 for the upper abdominal aorta to 11.34 +/- 4.05 mJ/cm2 for the lower abdominal aorta. An ANOVA showed that the lower abdominal aorta tore at lower pressures initially, but required much more energy to propagate the dissection. We believe that this is because of structural differences in the elastin pattern in the abdominal aorta.

Animals↗
PubMed1992

Modulation of acute morphine tolerance by corticotropin-releasing factor and dynorphin A in the mouse spinal cord.

Previously, we have demonstrated that intrathecally (i.t.) administered corticotropin-releasing factor (CRF) in mice produces stimulus-specific antinociception and modulation of morphine-induced antinociception by mechanisms involving spinal kappa opioid receptors. Recently, we also have found that CRF releases immunoreactive dynorphin A, a putative endogenous kappa opioid receptor agonist, from superfused mice spinal cords in vitro. Dynorphin A administered intracerebroventricularlly (i.c.v.) to mice has been shown to modulate the expression of morphine tolerance. In the present study, the possible modulatory effects of i.t. administered CRF as well as dynorphin A on morphine tolerance were studied in an acute tolerance model. Subcutaneous administration of 100 mg/kg of morphine sulfate (MS) to mice caused an acute tolerance to morphine-induced antinociception. The antinociceptive ED50 of MS was increased from 4.4 mg/kg (naive mice) to 17.9 mg/kg (4 hours after the injection of 100 mg/kg MS). To study the modulatory effects of spinally administered CRF and dynorphin A on the expression of morphine tolerance, CRF and dynorphin A were injected i.t. at 15 min and 5 min, respectively, before testing the tolerant mice by the tail-flick assay. The antinociceptive ED50 of MS in tolerant mice was decreased to 8.8 mg/kg and 7.1 mg/kg, respectively, after i.t. administration of CRF (0.1 nmol) and dynorphin A (0.2 nmol). In contrast, 0.5 nmol of alpha-helical CRF (9-41), a CRF antagonist and 0.4 nmol of norbinaltorphimine, a highly selective kappa opioid receptor antagonist, when administered i.t. at 15 min before the tail-flick test in tolerant mice, increased the antinociceptive ED50 of MS to 56.6 mg/kg and 88.8 mg/kg, respectively. These data confirmed the modulatory effect of dynorphin A on morphine tolerance and suggested that CRF, which releases dynorphin A in several central nervous system regions, also plays a modulatory role in the expression of morphine tolerance.

Animals↗
PubMed1992

Effect of peripheral nerve stimulation on the dorsal horn cell activity in cats with cutaneous inflammation.

There are some reports showing that an experience of long-enduring pain causes a change in the pain transmission system, suggesting a plastic nature of the nociceptive system. However, most of the studies concerning the analgesic effect of peripheral nerve stimulation dealt with normal animal or human subjects. So, the present study was undertaken to investigate the effect of peripheral nerve stimulation on the dorsal horn cell activity using a tonic pain model, which was made by producing a cutaneous inflammation. The main results are summarized as follows. 1) The evoked activity by electrical or natural stimulation as well as spontaneous activity was enhanced, and the receptive field size was also expanded by the inflammation. 2) Peripheral nerve conditioning stimulation reduced the C-response of the dorsal horn cell in the normal and inflamed group, and the degree of inhibition between the two groups showed no significant difference. 3) Inhibition of the C-response of the dorsal horn cells by peripheral conditioning stimulation was completely reversed by naloxone in the inflamed group whereas there was a partial block in the normal group.

Analgesia↗
PubMed1992

Compartmental analysis of RBC circulation through the rabbit kidney.

This experiment involved 12 rabbits of both sexes, weighing 2.1 kg. After anesthesia, the kidneys were exposed, isolated and cannulated in the renal artery, ureter and sometimes in the vein as well. The kidney were perfused through the renal artery with Krebs-Henseleit solution, which were then filtered to be free of particles, gased with 95% O2-5% CO2, and kept at 37 degrees C. We measured RBCs concentrations by means of Coulter Counter in the venous outflow collected, and plotted them against the volume perfused. Using 2 different flow rates, 9 ml/min (group I) and 19 ml/min (group II), we found that the RBCs decreased in a multiexponential decay fashion and a biophysical model for each flow rate was constructed. These models indicated that there were more cell stores (2.20 x 10(10)) in the fast compartment of group II than in group I (1.72 x 10(10)). This difference is not statistically significant, but certainly coincides with urine flow collected from ureter cannula during perfusion. Our present data clearly suggest that in order to clear 99% blood cells out of 10-12 gm rabbit kidneys, at least 3-6 ml of cell free perfusate is required while clearing the whole blood cells out of human kidneys (200-240 gm) may need 600 ml or more. Thus, we recommend that at least 600 ml of perfusate should be used to clear most of the blood cells in the renal vasculature before renal transplantation is performed.

Animals↗
PubMed1992

Morphological evidence of pulmonary vascular leakage through gaps observed with casting methods and S.E.M.

We have used selective casting methods to separate pulmonary elastin from vascular elastin in the lungs of rabbits, dogs and pigs. The lungs are digested with 0.1 N NaOH at 75 degrees C for 24 approximately 48 hours with frequent turning as the lungs are filled with air to about 80% of the vital capacity prior to the casting which is done at pressure of 20 approximately 50 mmHg. After vascular injections, we saw many small globular bits of casting material well separated from cast vessels and lying in the pulmonary elastin. Surface forces should make the casting material creep along the vessels even if they are not completely filled, so that the spherical shape is the one expected if the case is extruded into the parenchymal space and the air space. We conclude that this suggests that the pulmonary circulation is partially and temporarily 'open' as seen in the spleen and some other organs, rather than a completely 'closed' one as is generally accepted. At least some of these extravasations may be associated with lymphatics, although we have not proved this.

Animals↗
PubMed1992

Development of elastin layers in the aortic wall of human fetuses.

The presence of elastin layers in the aortic walls of twelve human fetuses was confirmed with scanning electron microscope pictures after hot alkali treatment and histochemical examination. In addition, the number of elastin layers in aortic walls of 5 different segments were compared in fetuses of varying ages. Aldehyde fuchsin stained slides of elastin ascending aortas showed a range between 27 and 55 layers of elastin in fetuses of 8 weeks to 32 weeks. However, in the lower abdominal aortas, elastin layers decreased from 28 to only 3 layers for fetuses of the same age. Furthermore, as elastin layers decreased from ascending aorta to abdominal aorta with the progression of fetal life, similar changes in the elastin lamellae were observed. These results suggest that while aortas grow rapidly in length, the medial elastin thickens slowly, perhaps due to slow development of hydrodynamic forces and pressures. Also the adventitial elastin appears to lose out gradually along the length from ascending aorta to abdominal aorta.

Aorta↗
PubMed1991

Internal intensity standards for heme protein UV resonance Raman studies: excitation profiles of cacodylic acid and sodium selenate.

We examine the utility of SO4(2-), ClO4-, cacodylic acid, and SeO4(2-) as internal intensity standards for Raman spectral measurements of protein structure. We find that 0.1 M SO4(2-) and ClO4- perturb the protein tertiary structure of aquomethemoglobin (met-Hb) and its fluoride (met-HbF) and azide (met-HbN3) complexes. Changes occur for the tryptophan near-UV absorption bands, the iron spin state is altered, and the fluoride ligand affinity decreases. Concentrations of ClO4- and SO4(2-) as low as 0.1 M suppress the met-HbF quaternary R----T transition induced by the allosteric effector inositol hexaphosphate (IHP). In contrast, similar concentrations of cacodylic acid and SeO4(2-) show little effect on the hemoglobin tertiary or quaternary protein structures or upon the R----T transition induced by IHP. We measure the Raman cross sections of cacodylic acid and SeO4(2-) between 218 and 514.5 nm and find that for UV excitation they are ca. 5-fold larger than ClO4- or SO4(2-). Thus, cacodylic acid and selenate can be used at lower concentrations. Cacodylic acid and SeO4(2-) are superior Raman internal intensity standards for protein structural studies.

Cacodylic Acid↗
PubMed1990

Heterogeneous electron transfer of cytochrome c facilitated by polypyrrole and methylene blue polypyrrole film modified electrodes.

Polypyrrole and methylene blue incorporated polypyrrole thin-film modified electrodes were prepared by the electrochemical polymerization method. These modified electrodes may facilitate heterogeneous electron transfer of cytochrome c with high electrocatalytic activity and good stability. Optical thin-layer spectroelectrochemical techniques were used to determine the characteristics of these electrochemical processes such as formal redox potential (E0), electron transfer number (n), and the apparent rate constant (ks.h0).

Cytochrome c Group↗