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Biomedical subjects

D H Shin

Publications and source records attributed to D H Shin.

At least 109 records · Page 6Linked to original sources
PubMed1999

Idiopathic bronchiolitis obliterans with organizing pneumonia presenting with spontaneous hydropneumothorax and solitary pulmonary nodule.

The first case of idiopathic bronchiolitis obliterans with organizing pneumonia (BOOP) presenting as solitary pulmonary nodule with spontaneous hydropneumothorax is reported in a 54-year-old man. A wedge resection of the right lower lobe was performed to show typical histological features of BOOP. This case report demonstrates that BOOP has a very diverse clinical manifestation and stresses the need to include solitary pulmonary nodule with hydropneumothorax in the spectrum of BOOP.

Cryptogenic Organizing Pneumonia↗
PubMed1999

Spectrum of opportunistic infections and malignancies in patients with human immunodeficiency virus infection in South Korea.

To determine the frequency and types of major opportunistic diseases in patients with HIV infection in South Korea, we reviewed the medical records of 173 HIV-infected patients. The patients were seen from 1985 to 1998 at a referral hospital for AIDS in South Korea. Most patients (85%) were male, and 107 (62%) were infected by heterosexual contacts. CD4+ lymphocyte counts at presentation were <200/microL in 27% of the patients. Tuberculosis was the most frequent opportunistic infection (25% of patients), followed by candidiasis (21%), herpes zoster (20%), Pneumocystis carinii pneumonia (10%), cytomegalovirus disease (9.8%). There were no cases of toxoplasmosis. Kaposi's sarcoma developed in 3 patients (1.7%), and non-Hodgkin's lymphoma, in 2 (1.2%). Eleven patients (6.4%) developed peripheral neuropathy, and 8 (4.6%) had HIV encephalopathy. Tuberculosis was the single most important HIV-related infection in South Korean patients.

AIDS-Related Opportunistic Infections↗
PubMed1999

Mucormycosis of the central airways: CT findings in three patients.

Computed tomographic (CT) findings are described in three diabetic patients with central airways mucormycosis. The CT findings of the tracheobronchial mucormycosis include enhancing areas of mural thickening (n = 3), luminal narrowing (n = 3), intramural air (n = 3), low-attenuation nonenhancing bronchial wall thickening (n = 2), and bronchonodal fistula formation (n = 1). These CT features in a diabetic patient should raise a high index of suspicion for tracheobronchial mucormycosis, particularly when typical radiographic features of pulmonary tuberculosis are absent.

Aged↗
PubMed1999

Protopanaxatriol ginsenosides inhibit glucose uptake in primary cultured rabbit renal proximal tubular cells by arachidonic acid release.

Ginsenosides are involved in protective action against renal dysfunction and the regulation of renal functions. However, the effects of ginsenosides on glucose reabsorption are not yet known in renal proximal tubular cells. The aim of this study was to examine the effects of ginsenosides, protopanaxadiol (PD) saponin and protopanaxatriol (PT) saponin, on alpha-methyl-D-glucopyranoside (alpha-MG) uptake and its mechanism of action in primary cultured rabbit renal proximal tubular cells (PTCs). The alpha-MG uptake was inhibited by 90% by 0.5mM phloridizin and by removal of Na+ in the PTCs. These are typical characteristics described for the proximal tubule. To determine the time- and dose-dependent effects of PD and PT saponins on alpha-MG uptake, PTCs were incubated with different concentrations of PD and PT saponins (10-100 microg/ml) and for different time periods (from 10 min to 24 h). PT saponin (>/=50 microg/ml) from 30 min inhibited alpha-MG uptake; however, PD saponin did not alter the alpha-MG uptake at any doses and time periods. In the kinetic analysis of alpha-MG uptake, PT saponin produced a significant decrease in Vmax. The PT saponin induced inhibition of alpha-MG uptake was blocked by mepacrine, a phospholipase A2 inhibitor. In addition, PT saponin increased [3H] arachidonic acid release by 218% of that of control, and this effect was also completely blocked by mepacrine. In conclusion, PT saponin inhibited, in part, alpha-MG uptake through the phospholipase A2 signal pathway in primary cultured rabbit renal PTCs.

Animals↗
PubMed1999

Effects of interleukin-10 on chemokine KC gene expression by mouse peritoneal macrophages in response to Candida albicans.

Chemokine KC has been considered to be a murine homologue of human GRO/MGSA and was identified as chemoattractant for monocytes and neutrophils. This study examined the expression of KC mRNA in thioglycollate-elicited mouse peritoneal macrophages that were stimulated in vitro with Candida albicans (CA). Also examined were the inhibitory effects of IL-10 on the CA-induced expression of KC gene by Northern blot analysis. CA was found to induce chemokine gene expression in a gene-specific manner, CXC chemokine IP-10 mRNA expression was not detected in CA-stimulated macrophages. Maximum KC mRNA expression was observed approximately 2 hr after adding CA. The inhibitory action of IL-10 to CA-induced KC mRNA expression on mouse peritoneal macrophages was independent on concentration and stimulation time of IL-10 and was observed approximately one hour after adding IL-10 and CA simultaneously. IL-10 produced a decrease in the stability of KC mRNA, and CA-stimulated macrophages with cycloheximide blocked the suppressive effect of IL-10. These results suggest that CA also induces chemokine KC from macrophages, and IL-10 acts to destabilize CA-induced KC mRNA and de novo synthesis of an intermediate protein is a part of the IL-10 suppressive mechanism.

Animals↗
PubMed1999

Intermittent parathyroid hormone treatment can promote linear growth in the ovariectomized growing rat.

To compare the effect of intermittent parathyroid hormone (PTH) treatment with that of estrogen treatment on epiphyseal growth in ovariectomized rats, 46 Sprague-Dawley female rats aged 9-10 weeks (about 200-220 g) were either ovariectomized or sham operated. From 6 weeks after ovariectomy (ovx), rats were daily injected with subcutaneous human recombinant PTH (1-84)-dosed 30 micrograms/kg (the low dose PTH-treated group) or 300 micrograms/kg (the high dose PTH-treated group), 17 beta-estradiol (the 17 beta-estradiol-treated group, 30 micrograms/kg) or vehicle (the ovx-alone group), 5 times a week for 4 weeks. The decalcified sections of the distal femoral epiphyseal plate were analyzed on light microscopy after H&E stain, and the lengths of the zones of proliferation, maturing and hypertrophic chondrocytes were measured. The length of the growth plate, the zone of proliferation and the zone of hypertrophic chondrocyte in the ovx-alone group were significantly shorter than those of the sham-operated group. The treatment of 17 beta-estradiol speeded up the differentiation of cells from proliferating chondrocytes to maturing and hypertrophic chondrocytes even though the length of the growth plate was comparable to that of the sham-operated group. Both low and high dose PTH treatments increased the length of the growth plate, and those lengths were comparable to that of the sham-operated group. The fractions of proliferating, maturing and hypertrophic zone in the low dose PTH-treated group were also comparable to those of the sham-operated group. However, high dose PTH treatment slowed down the differentiation of cells from proliferating chondrocytes to maturing and hypertrophic chondrocytes to a greater extent, and therefore the fraction of proliferating chondrocytes of the high dose PTH-treated group was larger than that of the low dose PTH-treated group (73.8 +/- 1.8 Vs 63.3 +/- 1.3%, p < 0.005). From these results, we showed that intermittent PTH treatment could promote linear growth in the ovariectomized growing rat. We propose that PTH may be an alternative drug candidate for promoting linear growth of long bones without the risk for early closure of the growth plate.

Animals↗
PubMed1999

Retroperitoneal multilocular bronchogenic cyst adjacent to adrenal gland.

Bronchogenic cysts are generally found in the mediastinum, particularly posterior to the carina, but they rarely occur in such unusual sites as the skin, subcutaneous tissue, pericardium, and even the retroperitoneum. A 30-year-old Korean man underwent surgery to remove a cystic adrenal mass incidentally discovered during routine physical checkup. At surgery, it proved to be a multilocular cyst located in the retroperitoneum adjacent to the left adrenal gland. Microscopically, the cyst was lined by respiratory epithelium over connective tissue with submucous glands, cartilage and smooth muscle, thereby histologically confirming bronchogenic cyst. This is the first reported case of retroperitoneal bronchogenic cyst in an adult without other congenital anomalies in Korea.

Adrenal Glands↗
PubMed1998

Patterns of status epilepticus-induced neuronal injury during development and long-term consequences.

The lithium-pilocarpine model of status epilepticus (SE) was used to study the type and distribution of seizure-induced neuronal injury in the rat and its consequences during development. Cell death was evaluated in hematoxylin- and eosin-stained sections and by electron microscopy. Damage to the CA1 neurons was maximal in the 2- and 3-week-old pups and decreased as a function of age. On the other hand, damage to the hilar and CA3 neurons was minimal in the 2-week-old rat pups but reached an adult-like pattern in the 3-week-old animals, and damage to amygdalar neurons increased progressively with age. The 3-week-old animals also demonstrated vulnerability of the dentate granule cells. To evaluate neuronal apoptosis, we used terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick end labeling (TUNEL) stain, confocal fluorescence microscopy of ethidium bromide-stained sections, electron microscopy, and DNA electrophoresis. Neurons displaying all of those features of apoptotic death in response to SE were seen in the CA1 region of the 2-week-old pups and in the hilar border of the dentate granule cells of the 3-week-old animals. Some (3/11) of the animals that underwent SE at 2 weeks of age and most of the animals that underwent SE at 3 or 4 weeks of age (8/11 and 6/8, respectively) developed spontaneous seizures later in life; the latter showed SE-induced synaptic reorganization as demonstrated by Timm methodology. These results provide strong evidence for the vulnerability of the immature brain to seizure-induced damage, which bears features of both necrotic and apoptotic death and contributes to synaptic reorganization and the development of chronic epilepsy.

Age Factors↗
PubMed1998

Effects of the cys mutations on structure and function of the ATP-dependent HslVU protease in Escherichia coli. The Cys287 to Val mutation in HslU uncouples the ATP-dependent proteolysis by HslvU from ATP hydrolysis.

To define the role of the Cys residues in the ATP-dependent HslVU protease, mutagenesis was performed to replace either Cys261 or Cys287 in HslU with Val and Cys159 in HslV with Ser or Ala. Whereas HslU/C261V could hydrolyze ATP and support the ATP-dependent proteolytic activity of HslV as well as the wild-type HslU, HslU/C287V could not hydrolyze ATP. Nevertheless, HslU/C287V could support the HslV-mediated proteolysis by forming the HslVU complex in the presence of ATP but not its absence, indicating that ATP binding but not its hydrolysis is essential for proteolysis. Whereas treatment of N-ethylmaleimide (NEM) resulted in dissociation of the oligomeric HslU into monomers, the C261V mutation, but not C287V, prevented the NEM effect. These results suggest that Cys261 is involved in oligomerization and that Cys287 is related to the ATPase function of HslU. NEM also dissociated the dodecameric HslV into monomers, and this effect could be prevented by either the C159S or C159A mutation, suggesting the involvement of Cys159 in oligomerization of HslV. Moreover, either mutation abolished both the basal and HslU-activated proteolytic activity of HslV and its ability to activate the HslU ATPase and to form the HslVU complex, indicating that Cys159 is essential for the proteolytic activity of HslV and its interaction with HslU. These results suggest that the Cys residues play an important role in maintaining the structure and function of the HslVU protease.

ATP-Dependent Proteases↗
PubMed1998

Immunocytochemical study on the distribution of NOS-immunoreactive neurons in the cerebral cortex of aged rats.

Nitric oxide (NO) involvement has been demonstrated in mechanisms of synaptic plasticity, particularly in hippocampal long-term potentiation, a mechanism that underlies certain forms of learning and memory. Several findings suggest that NO production may be decreased in the aged rats. Changes in the nNOS-containing neurons with ageing were demonstrated by immunocytochemistry. NOS-immunoreactive (IR) cells in aged rats were present in all cortical areas and the hippocampus, and the pattern of distribution was similar to that of the control group. The number of NOS-IR cells in the cerebral cortex was significantly decreased in the aged rats, but the extent of changes was variable in each area, and ranged from mild decrease (< 30%) to severe decrease (> 50%). Severely decreased areas were the cingulate cortex, parietal cortex area 1, temporal cortex area 1, 2, 3, medial part of occipital cortex area 2, monocular and binocular part of occipital cortex area 1, entorhinal cortex, hippocampus proper, dentate gyrus and subiculum. Morphologically, the number of dendritic branches seemed to be decreased in aged group and the length of dendrites of NOS-IR neurons showed a tendency to shorten. These results indicate the involvement of neuronal system containing NOS in the ageing brain, and provide the first morphological evidence for the loss of NOS neurons in the cerebral cortex of the aged rats by immunocytochemistry.

Aging↗
PubMed1998

Magnone A and B, novel anti-PAF tetrahydrofuran lignans from the flower buds of Magnolia fargesii.

In a search for platelet-activating-factor (PAF) antagonists, two new lignan compounds were isolated from the Chinese crude drug shin-i, the flower buds of Magnolia fargesii. Their structures were elucidated as (2S,3R,4R)-tetrahydro-2-(3,4-dimethoxyphenyl)-4-(3, 4-dimethoxybenzoyl)-3-(hydroxymethyl)furan (magnone A, 1) and (2S,3R, 4R)-tetrahydro-2-(3,4,5-trimethoxyphenyl)-4-(3, 4-dimethoxybenzoyl)-3-(hydroxymethyl)furan (magnone B, 2). Magnones A and B showed antagonistic activity against PAF in the [3H]PAF receptor binding assay with the IC50 values of 3.8 x 10(-5) M and 2.7 x 10(-5) M, respectively.

Animals↗
PubMed1998

Localization of transferrin binding protein in relation to iron, ferritin, and transferrin receptors in the chicken cerebellum.

We have demonstrated that transferrin binding protein (TfBP), ferritin, and iron, are specifically localized in Bergmann glia, while the transferrin receptor is confined to Purkinje cells in the chicken cerebellum. The results of this study suggest that Bergmann glia have previously undescribed functions related to iron regulation such as sequestration of iron and the maintenance of iron homeostasis in the cerebellum.

Animals↗
PubMed1998

Reactive astrocytes express nitric oxide synthase in the spinal cord of transgenic mice expressing a human Cu/Zn SOD mutation.

The distribution of the neuronal isoform of nitric oxide synthase (nNOS) in the spinal cord of transgenic mice expressing a mutated human copper/zinc superoxide dismutase gene was enhanced when investigated by immunocytochemistry. Immunocytochemistry showed intensely stained NOS-immunoreactive (IR) glial cells with the appearance of astrocytes in the spinal cord and brain stem of transgenic mice, but none were observed at these sites in control mice. Using antisera directed against GFAP, the specific marker for astrocyte, the glial cells were confirmed by immunocytochemistry to be astrocytes. This immunocytochemical evidence suggests that nitric oxide may mediate glutamate neurotoxicity, and this study provides the first in vivo evidence that nitric oxide may be implicated in the pathologic process of human familial amyotrophic lateral sclerosis.

Animals↗
PubMed1998

Comparison of solution and crystal structures of maize nonspecific lipid transfer protein: a model for a potential in vivo lipid carrier protein.

The three-dimensional solution structure of maize nonspecific lipid transfer protein (nsLTP) obtained by nuclear magnetic resonance (NMR) is compared to the X-ray structure. Although both structures are very similar, some local structural differences are observed in the first and the fourth helices and in several side-chain conformations. These discrepancies arise partly from intermolecular contacts in the crystal lattice. The main characteristic of nsLTP structures is the presence of an internal hydrophobic cavity whose volume was found to vary from 237 to 513 A3 without major variations in the 15 solution structures. Comparison of crystal and NMR structures shows the existence of another small hollow at the periphery of the protein containing a water molecule in the X-ray structure, which could play an important structural role. A model of the complexed form of maize nsLTP by alpha-lysopalmitoylphosphatidylcholine was built by docking the lipid inside the protein cavity of the NMR structure. The main structural feature is a hydrogen bond found also in the X-ray structure of the complex maize nsLTP/palmitate between the hydroxyl of Tyr81 and the carbonyl of the lipid. Comparison of 12 primary sequences of nsLTPs emphasizes that all residues delineating the cavities calculated on solution and X-ray structures are conserved, which suggests that this large cavity is a common feature of all compared plant nsLTPs. Furthermore several conserved basic residues seem to be involved in the stabilization of the protein architecture.

Amino Acid Sequence↗
PubMed1998

Rice non-specific lipid transfer protein: the 1.6 A crystal structure in the unliganded state reveals a small hydrophobic cavity.

This study describes the high-resolution X-ray structure of the non-specific lipid transfer protein (ns-LTP) from rice seeds in the unliganded state. The model has been refined to a crystallographic R-factor of 0.186 for 8.0 to 1.6 A data (with Fo > 2 sigma F). It accounts for all 91 amino acid residues, 68 water molecules, one sulfate ion, and two molecules of 3-[cyclohexylamino]-1-propanesulfonic acid. The root-mean-square deviations from ideal bond lengths and angles are 0.017 A and 1.76 degrees, respectively. The overall fold of rice ns-LTP is very similar to that of maize ns-LTP. A superposition of 91 common C alpha atoms in rice and maize ns-LTPs, both in the unliganded state, gives a root-mean-square deviation of 1.2 A. Large structural differences from the crystal structure of maize ns-LTP are observed in two regions: the loop between two alpha-helices H1 and H2, where one residue deletion (Gln21 of maize sequence) occurs, and the C-terminal region around Tyr79. The C-terminal region of rice protein is somewhat collapsed into the hydrophobic cavity. As a consequence, its hydrophobic cavity is considerably smaller than that of maize protein (144 A3 versus 408 A3 for van der Waals cavity volumes), despite a high level of sequence identity (79%) between them. In the rice ns-LTP structure, the side-chain of Arg44 partially blocks the mouth of the cavity, while the side-chain of Ile81 effectively closes the other end by protruding into the cavity. And the side-chain of Tyr79 divides the cavity into two parts, with the larger part being shielded from the solvent. The present study illuminates the structure-function relationship of rice ns-LTP and allows a detailed structural comparison with other plant ns-LTPs.

Amino Acid Sequence↗
PubMed1998

Molecular characterization of tobacco squalene synthase and regulation in response to fungal elicitor.

The enzyme squalene synthase (SS) represents the first commitment of carbon from the general isoprenoid pathway toward sterol biosynthesis and is a potential point for regulation of sterol biosynthesis. The isolation and characterization of tobacco (Nicotiana tabacum) squalene synthase (TSS) cDNA and genomic DNA clones, as well as determination of the steady state level of TSS mRNA in response to elicitor treatment, were investigated. cDNA clones for TSS were isolated from poly (A)+ RNA using a reverse transcription/polymerase chain reaction (RT/PCR) method. A 1233-bp cDNA clone was generated that contained an open reading frame of 411 amino acids giving a predicted molecular mass of 46.9 kDa. Comparison of the TSS deduced amino acid sequence with currently described SS from different species showed the highest identify with Nicotiana benthamiana (97%), followed by Glycyrrhiza glabra (81%), Arabidopsis thaliana (74%), rat (40%), and yeast (37%). Expression of a soluble form of the TSS enzyme with enzymatic activity in Escherichia coli was achieved by truncating 24 hydrophobic amino acids at the carboxy terminus. Characterization of genomic TSS (gTSS) revealed a gene of 7.086 kb with a complex organization of small exons and large introns not typical of plant genes. Southern blot hybridization indicated only two copies of the SS gene in the tobacco genome. Treatment of tobacco cell suspension cultures with a fungal elicitor dramatically reduced TSS enzymatic activity, lowering it to zero within 24 h. Analysis of TSS mRNA levels, by RNA blot hybridization and primer extension assays, in elicitor-treated cells indicated that the transcript level remained largely unchanged over this 24-h period. These results suggest that the suppression of TSS enzyme activity in elicitor-treated cells may result from a posttranscriptional modification of TSS.

Amino Acid Sequence↗
PubMed1998

Long-term outcome of primary glaucoma triple procedure with adjunctive 5-fluorouracil.

PURPOSE: To evaluate the long-term effect of adjunctive subconjunctival 5-fluorouracil (5-FU) on the filtration outcome of primary glaucoma triple procedure (PGTP) in primary open-angle glaucoma (POAG) patients. METHODS: Seventy-four POAG patients were randomly assigned to PGTP alone (36 patients) or PGTP with adjunctive subconjunctival 5-FU (5.0 +/- 1.3 injections of 5 mg each, total of 24.8 mg) (38 patients). After surgery, the patients were examined at regular intervals for intraocular pressure (IOP), visual acuity, medical therapy requirements, and complications. Surgical success was defined as IOP < or = 20 mmHg on postoperative medication < or = 1 without additional glaucoma surgery. RESULTS: Over an average follow-up (+/- SD) of 45.3 +/- 25.0 months, both 5-FU and control groups maintained significant improvement of IOP control and visual acuity. However, there were no statistically significant differences between the 5-FU and control groups with respect to postoperative IOP, number of glaucoma medications, visual acuity outcome, and success rate overall or in selected patients with one or more of the risk factors for filtration failure. CONCLUSIONS: The use of low-dose subconjunctival 5-FU (mean dosage of 24.8 mg in 5.0 +/- 1.3 injections) as an adjunct did not significantly improve the long-term filtration outcome of PGTP in POAG patients.

Aged↗