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H S Yu

Publications and source records attributed to H S Yu.

At least 55 records · Page 3Linked to original sources
PubMed1998

The effect of human polyclonal anti-dsDNA autoantibodies on apoptotic gene expression in cultured rat glomerular mesangial cells.

In our previous studies, we found that polyclonal anti-double-stranded DNA antibodies (anti-dsDNA) purified from sera of patients with active systemic lupus erythematosus (SLE) were cytotoxic to cultured rat glomerular mesangial cells (RMC) through an apoptotic mechanism. In order to determine whether these nephritogenic antibodies affect the expression of apoptosis-related genes in the tissues, the expression of Fas, p53, c-myc, and bcl-2 genes in the kidneys and livers of 12-week-old normal BALB/c and autoimmune MRL-lpr/lpr mice was detected by a reverse transcription-assisted polymerase chain reaction (RT-PCR). We found the mRNA of the four genes were expressed in the tissues of the normal mice. In contrast, decreased expression of the four genes in the kidney and absent expression of bcl-2 in the liver of the lpr mice were noted. Interestingly, RMC only expressed p53 and c-myc, but not Fas or bcl-2, in culture. The purified polyclonal anti-dsDNA dose-responsively (50-200 IU/ml) suppressed the 3H-thymidine incorporation of RMC after incubation for 48 h. However, the incubation of 100 IU/ml of anti-dsDNA with RMC for 4 h did not affect the expression of these apoptotic genes. The results suggest that anti-dsDNA induce RMC apoptosis via an unidentified mechanism different from Fas, c-myc or p53 pathway.

Animals↗
PubMed1998

Expression of bcl-2, p53 and Ki-67 in arsenical skin cancers.

To investigate the regulation of apoptosis and proliferation in arsenic-induced skin cancers, we examined the expression of bcl-2, p53, and Ki-67 using immunohistochemical staining. Thirty patients with Bowen's disease (BD), ten with basal cell carcinoma (BCC), eight with squamous cell carcinoma (SCC) and eleven of perilesional normal skin (PLN) of the non-sun exposure sites from endemic area were examined. The results showed that: 1) bcl-2 was expressed in all of the BCC homogeneously, in none of the SCC, and in 12/30 of the BD focally or homogeneously; 2) p53 was expressed in all of the arsenical skin cancers with a labelling index of 75 +/- 14% of BD, 50 +/- 17% of BCC, 61 +/- 15% of SCC, and also in all of the perilesional normal skin with a labelling index of 55 +/- 24%; 3) Ki-67 was expressed in all of the skin cancers with labelling index of 58 +/- 17% of BD, 12 +/- 7% of BCC, 47 +/- 21% of SCC, and in 9/11 of PLN with a labelling index of 41 +/- 24%. Expression of bcl-2 in BCC or BD is related to the phenotype of germinative basal cell. The constant expression of bcl-2 i early dysplastic cells of BD and the earliest expression of P53 in the basal cells of perilesional normal skin indicate that the initial step of arsenic-induced carcinogenesis is from the basal germinative cells. There is no mutual relationship between bcl-2, p53 or Ki-67 expression in any type of the arsenical skin cancers, but there is a positive correlation between p53 and Ki-67 expression identified in perilesional normal skin. BD had the highest labelling index of p53 and Ki-67.

Aged↗
PubMed1998

Sensory rhodopsin II transducer HtrII is also responsible for serine chemotaxis in the archaeon Halobacterium salinarum.

Previously, we demonstrated that the methyl-accepting protein HtrII is the transducer for photoreceptor sensory rhodopsin II. Here, we provide experimental evidence that HtrII is also a chemotransducer. Using an agarose-in-plug bridge method, we show that an HtrII overexpression strain has a quicker response to serine than does an HtrII deletion strain. Furthermore, an in vivo flow assay demonstrates that the deletion strain is unable to modulate methylesterase activity after serine addition or photostimulation, while the overexpression strain shows distinct methanol peaks following both types of stimuli.

Archaeal Proteins↗
PubMed1998

Subgenus classification of Acanthamoeba by riboprinting.

Subgenus classification of Acanthamoeba remains uncertain. Twenty-three reference strains of Acanthamoeba including 18 (neo)type-strains were subjected for classification at the subgenus level by riboprinting. PCR/RFLP analysis of 18S rRNA gene (rDNA). On the dendrogram reconstructed on the basis of riboprint analyses, two type-strains (A. astronyxis and A. tubiashi) of morphological group 1 diverged early from the other strains and were quite distinct from each other. Four type-strains of morphological group 3, A. culbertsoni, A. palestinensis, A. healyi were considered taxonomically valid, but A. pustulosa was regarded as an invalid synonym of A. palestinensis. Strains of morphological group 2 were classified into 6 subgroups. Among them, A. griffini which has an intron in its 18S rDNA was the most divergent from the remaining strains. Acanthamoeba castellanii Castellani, A. quina Vil3, A. lugdunensis L3a, A. polyphaga Jones, A. triangularis SH621, and A. castellanii Ma strains belonged to a subgroup, A. castellanii complex. However, A. quina and A. lugdunensis were regarded as synonyms of A. castellanii. The Chang strain could be regarded as A. hatchetti. Acanthamoeba mauritaniensis, A. divionensis, A. paradivionensis could be considered as synonyms of A. rhysodes. Neff strain was regarded as A. polyphaga rather than as A. castellanii. It is likely that riboprinting can be applied for rapid identification of Acanthamoeba isolated from the clinical specimens and environments.

Acanthamoeba↗
PubMed1998

Technetium-99m(V)-DMSA and gallium-67 in the assessment of bone and joint infection.

UNLABELLED: The aim of our study was to investigate the diagnostic value of scans with 99mTc(V)-dimercaptosuccinic acid (DMSA) to localize bone and joint infection compared with scans using 67Ga. METHODS: Thirty-six patients referred for investigation of bone and joint infection were studied. In all patients, a bone scan was obtained initially. Subsequently, comparative scans with 99mTc(V)-DMSA and 67Ga were performed 1 wk apart. Microbiological findings, pathologic findings and/or clinical follow-up (until symptoms disappeared) were considered to be proof of the presence of bone and joint infection. RESULTS: Technetium-99m (V)-DMSA showed greater sensitivity and accuracy than 67Ga in the assessment of bone and joint infection, although the difference was not statistically significant. CONCLUSION: In comparison with a 67Ga scan, a 99mTc(V)-DMSA scan, in combination with a bone scan, is a reliable way to diagnose bone and joint infection. Both tracers were useful in the diagnosis of bone and joint infection.

Adult↗
PubMed1997

Change of cardiac beta-adrenoceptors in lead-exposed rats.

The effect of lead on cardiac beta-adrenoceptors was studied. Wistar rats used in these trials were divided into seven groups of ten animals each (A-G). Of these, groups B was given drinking water containing 0.01% lead acetate, group C 0.05%, group D 0.1%, group E 0.5%, group F 1% and group G 2% for a period of 60 days. Group A was given pure water. A radioligand-binding assay fulfilling strict criteria of receptor affinity and density was used to quantify cardiac beta-adrenoceptors. Application of a trend test indicated that both blood and heart lead levels increased significantly from group A to group G (A < G), but that beta-adrenoceptor density decreased (G < A), whereas Kd did not vary among the seven groups. Linear regression analysis showed that decrease of cardiac beta-adrenergic receptor density was closely related to elevation of blood and heart lead levels. The results show that lead exposure results in a reduction of cardiac beta-adrenoceptor density.

Animals↗
PubMed1997

An agarose-in-plug bridge method to study chemotaxis in the Archaeon Halobacterium salinarum.

A simple agarose-in-plug bridge method was developed to study chemotaxis in the Archaeon Halobacterium salinarum. Preheated liquid agarose solution with chemoeffectors is pipetted in the middle of a microscope slide bridge, constructed by placing two plastic strips 16 mm apart. A coverslip is immediately placed over the agarose. The solidified agarose plug is completely encircled with the halobacterial cell suspension. Within a certain time concentrated halobacteria were seen as a ring at the edge of the agarose plug containing attractant amino acids and the control growth medium. Chemotaxis mutant Pho60 cells do not accumulate either around the attractants or around the growth medium. The kinetics of the ring formation can be readily videotaped or photographed using either phase-contrast or dark-field microscopy.

Bacteriological Techniques↗
PubMed1997

The expression of genes modulating programmed cell death in normal human polymorphonuclear neutrophils.

Normal human polymorphonuclear neutrophils (PMN) have a short life and die in progression via apoptosis. In order to understand the molecular basis of PMN apoptosis, the expression of apoptosis-related (Fas, Fas-ligand, p53, and c-myc) and survival-related (bcl-2) genes was detected by flow cytometry, Western blot and reverse transcription-assisted polymerase chain reaction (RT-PCR). We found that Fas and Fas-ligand (FasL) were expressed on the surface of most of the cells. However, the disappearance of FasL was much faster than Fas after 24 h incubation. p53 and bcl-2 were also expressed in the cytoplasm of most of the cells. In contrast, the expression of c-myc was negligible in PMN. The addition of monoclonal anti-human Fas antibody (25 micrograms/ml) to PMN suspension enhanced whereas anti-FasL antibody (25 micrograms/ml) suppressed PMN apoptosis in 48 h incubation. These results suggest that the activation of Fas pathway induced by Fas-FasL interaction among PMNs is one of the mechanisms for spontaneous PMN apoptosis. Lack of proto-oncoprotein c-myc expression in PMN is responsible for their non-proliferative property and may aggravate the spontaneous apoptosis of the cells.

Animals↗
PubMed1997

Use of dynamic capillaroscopy for studying cutaneous microcirculation in patients with diabetes mellitus.

To investigate the relationship between cutaneous microcirculation and retinopathy in diabetes mellitus, we studied by dynamic capillaroscopy 35 diabetes mellitus patients, including 10 patients without retinopathy, 10 patients with background retinopathy, and 15 patients with proliferative retinopathy. We found that (1) cutaneous and retinal microcirculation in diabetes mellitus in long-term diabetes mellitus, regressional rather than proliferational changes occurred in skin vasculature as compared to that in retina; (2) functional impairments of cutaneous microcirculation, that is, decreased resting capillary blood cell velocity, peak blood cell velocity, and prolonged time to peak capillary blood cell velocity by dynamic capillaroscopy, could be detected in diabetes mellitus patients without retinopathy; (3) the degree of tortouosity of capillaries, impairment in peak capillary blood cell velocity, and time to peak capillary blood cell velocity of cutaneous microcirculation were significantly correlated with the gravity of retinopathy in diabetes mellitus patients; (4) abnormal leakage of fluorescence in cutaneous microcirculation appeared in diabetes mellitus patients with or without abnormal fluorescein angiography in retina. In conclusion, dynamic capillaroscopy used in concert with ophthalmoscopy and fluorescein angiography can facilitate a comprehensive examination of vasculopathy in diabetes mellitus.

Adult↗
PubMed1997

Reduced vascular beta-adrenergic receptors and catecholamine response in rats with lead induced hypertension.

Beta-adrenergic receptor-mediated relaxation of blood vessels declines in lead induced hypertension although the mechanism is unknown. We have utilized the aorta of lead hypertensive rats to investigate this problem. In an effort to elucidate the mechanism responsible for this alteration we examined plasma catecholamine levels, vascular beta-adrenergic receptor density, and cyclic adenosine monophosphate (cAMP) production in lead hypertensive rats. The density of beta-adrenergic receptors was 41% lower in the blood vessels of lead hypertensive rats compared with control rats. The corresponding apparent Kd values were not significantly different between two groups. The plasma catecholamine level was significantly higher in lead hypertensive rats compared with controls (P < 0.001). Stimulation of the vascular beta-adrenoceptor resulted in significantly lower levels of cAMP in lead hypertensive rats compared with controls (P < 0.001). The present results suggest that there is reduced beta-adrenoceptor density and diminished cAMP accumulation in blood vessels from lead hypertensive rats. Plasma catecholamine may play a role in the diminished beta-adrenoceptor and responsiveness to cAMP-mediated vascular relaxation in lead exposure.

Adrenergic beta-Agonists↗
PubMed1997

Tamm-Horsfall glycoprotein (THG) is a binder for surface membrane proteins on blood cells and glomerular mesangial cells.

A macromolecule with a molecular weight of 90-100 kDa was purified from normal human pregnancy urine. The molecule was proved to be the Tamm-Horsfall glycoprotein (THG) by Western blot analysis. The macromolecule contains carbohydrate as detected by an enzyme immunoassay. Functionally, the glycoprotein can adhere to and stimulate the thymidine incorporation of human mononuclear cells (MNC) in modest degree via its membranotropic property. In addition to MNC, the protein can also bind to the surface of human polymorphonuclear neutrophils (PMN), red blood cells (RBC) and rat glomerular mesangial cells (RMC). Western blot analysis of various cell lysates with/without proteinase K pretreatment before cell lysis revealed that a 60 kDa and a molecule larger that 94 kDa on the surface of PMN, a 60 kDa protein on MNC and a 32 kDa protein on RBC are the binding molecules for THG. In contrast, many proteins on the surface of RMC could be bound by THG. Immunoprecipitation of membranous iodinated MNC lysates also confirmed that the 60 kDa molecule on MNC is the binding protein for THG. A number of monosaccharide including N-acetylneuraminic acid, N-acetyl-galactosamine, N-acetyl-glucosamine and alpha-methyl-D-mannoside could not inhibit the mitogenic effect of THG on human mononuclear cells. These results suggest that THG is capable of reacting with surface membrane proteins on different cells, but not through the specific carbohydrate-containing lectin-like receptors on the cell surface.

Animals↗
PubMed1997

Effect of growth factors on dermal fibroblast contraction in normal skin and hypertrophic scar.

We have examined the effects of four 'exogenous' growth factors, i.e. PDGF-BB (5 ng/ml), TGF-beta1 (5 ng/ml), bFGF (10 ng/ml) and EGF (10 ng/ml) on the contraction of floating collagen type I lattices populated by human normal skin (NS) and hypertrophic scar (HS) fibroblasts (FPCL). Only TGF-beta1 enhanced the contractility of both NS and HS fibroblasts in the collagen lattice (P < 0.01). Other growth factors (PDGF-BB, bFGF and EGF) did not affect FPCLs contraction at 72 h (P > 0.05). The onset effect of TGF-beta1 on NS-FPCL contraction was relative early at 24 h after FPCL casting as compared to a 72 h delay on HS-FPCL contraction. Besides, PDGF-BB was found to be able to enhance HS-FPCL contraction (P < 0.05) but not on NS-FPCL contraction on day 4. On the other hand, three enzyme-linked immunosorbent assays (ELISA) were performed to demonstrate quantitatively the 'endogenous' growth factors that fibroblasts secreted into the culture medium 48 h after FPCL casting. No appreciable difference was found between 10 NS and 11 HS samples tested for PDGF-AB immunoassay (11.48 +/- 5.5 pg/ml versus 12.20 +/- 5.34 pg/ml). The same result existed in 7 NS and 13 HS samples for TGF-beta2 immunoassay (15.15 +/- 6.2 pg/ml versus 11.84 +/- 7.46 pg/ml). In bFGF immunoassay study, relative variable data was noted in both 7 NS (18.18 +/- 13.18 pg/ml) and 12 HS samples (20.41 +/- 22.36 pg/ml). In conclusion, we suppose that TGF-beta role in wound healing may be due to the secondary exogenous influences. The endogenous ability of TGF-beta2 secretion (quantity) in HS fibroblasts are the same as NS fibroblasts but with delayed timing responses (quality) to exogenous TGF-beta1 effect in the collagen lattice. Further studies with timing-regulated selective specific monoclonal antibodies against the growth factor receptors may provide the therapeutic applications on HS during wound healing.

Becaplermin↗
PubMed1997

Alterations in IL-6, IL-8, GM-CSF, TNF-alpha, and IFN-gamma release by peripheral mononuclear cells in patients with active vitiligo.

The purpose of this study was to clarify the relationship between the cellular and humoral immune components in the pathogenesis of vitiligo vulgaris. By using cytokines as indicators of peripheral mononuclear cell (MNC) function, we compared the effects of phytohemagglutinin (PHA) and purified IgG on MNCs derived from patients suffering from active vitiligo with those from normal controls. The results revealed (i) a significant increase in spontaneous production of IL-6 and IL-8 in patients; (ii) PHA, purified IgG from patients (IgG-anti-MC), or IgG from normal controls (N-IgG) induced a significant increase in IL-6 but diminished GM-CSF, TNF-alpha, and IFN-gamma release in patients; and (iii) IgG-anti-MC brought about a significantly higher stimulatory effect on IL-1beta and IFN-gamma production than N-IgG in normal controls. Immunologically, IL-6 can enhance melanocyte ICAM-1 expression, which may increase leukocyte-melanocyte attachment and cause melanocyte damage in vitiligo. A decrease in GM-CSF (an intrinsic growth factor for melanocyte) production may retard recovery from vitiligo by checking the proliferation of surviving melanocytes. A significant decrease in TNF-alpha and IFN-gamma production may partially explain the reduced inflammatory reaction in vitiliginous lesions. That IgG-anti-MC stimulates an increase in IL-1beta and IFN-gamma production in controls suggests that IgG-anti-MC may play a role in melanocyte destruction mediated by monocytes.

Antibodies↗
PubMed1997

The inhibitory effect of UVB irradiation on the expression of p53 and Ki-67 proteins in arsenic-induced Bowen's disease.

The aim of this study is to evaluate the effect of ultraviolet B (UVB) on arsenic-induced Bowen's disease. Four patients were irradiated with 750 mJ/cm2 of UVB and biopsies were performed before treatment and 2 weeks later. Immunohistochemical stains of p53 and Ki-67 were compared by the labelled-streptavidin method before and after the UVB treatment. We found that the number of p53 and Ki-67 positive cells after the UVB treatment were significantly fewer than those of non-UVB-treated specimens. These results suggest that the UVB inhibitory effect in Bowen's disease needs further studies to clarify its value in potentially retarding the progression of the hyperproliferative status in overt skin cancer on a molecular basis.

Arsenic↗
PubMed1997

Live female Enterobius vermicularis in the posterior fornix of the vagina of a Korean woman.

A 33-year-old Korean woman, para 2. visited an obstetrics and gynecology clinic, Kumi-shi, Kyongsangbuk-do, due to postcoital spotting and flank pain. She had a tubal ligation 7 years before and demonstrated back pain during menstruation. She revealed a foul smelling discharge without complaint of itching. Enterobius vermicularis eggs were demonstrated during microscopic examination of a smear taken from the posterior fornix of the vagina. On endoscopic examination of her vagina, a live worm was found in the posterior fornix. The worm was removed and identified as a female E. vermicularis based on morphology. This is the first case report of vaginal enterobiasis in Korea.

Adult↗
PubMed1997

[Bacterial endosymbiosis within the cytoplasm of Acanthamoeba lugdunensis isolated from a contact lens storage case].

Transmission electron microscopy of an Acanthamoeba isolate (KA/L5) from a contact lens case revealed bacterial endosymbionts within cytoplasm of the amoebae. The Acanthamoeba isolate belonged to the morphological group II. Based on the polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) of 18S ribosomal RNA coding DNA (rDNA), the isolate was identified as A. lugdunensis. Strain typing by isoenzyme analysis using isoelectric focusing (IEF) and mitochondrial (Mt) DNA RFLP revealed that the isolate was closely related with KA/L1, the most predominant type of isolates from contact lens storage cases, KA/E2, a clinical isolate, KA/W4, previously reported to host endosymbionts, and L3a strains of A. lugdunensis. The endosymbionts were similar to those of KA/W4 in aspects that they were randomly distributed in both trophozoites and cysts, and were rod-shaped bacteria measuring approximately 1.38 x 0.50 microns. But the number of endosymbionts per amoeba was significantly lower than that of KA/W4. They were neither limited by phagosomal membranes nor included in lacunaelike structure.

Acanthamoeba↗