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Biomedical subjects

Y S Han

Publications and source records attributed to Y S Han.

At least 55 records · Page 3Linked to original sources
PubMed1997

Reticulocyte maturity index reflects erythropoietin effects in hemodialysis patients.

Flow cytometric reticulocyte analysis is widely utilized because of its sensitivity, precision, and high throughput of analysis as compared to manual reticulocyte counting. With this automated method reticulocytes can be classified into three groups according to the fluorescence intensity that reflects maturity of reticulocytes. In this study, changes in red cell parameters, reticulocyte percentage, absolute reticulocyte count, and reticulocyte maturity index were evaluated 13 hemodialysis patients with renal anemia after single administration of recombinant human erythropoietin. The reticulocyte count and reticulocyte maturity index were elevated significantly (P < .01) 2 days after the single bolus of erythropoietin, and they reached the maximum value vn the fourth day, but other red cell indices could not detect the effects of erythropoietin during this early period. These results suggested that the reticulocyte maturity index could be an early indicator of the effect of erythropoietin in hemodialysis patients.

Adult↗
PubMed1996

Increased tenascin expression is an early feature of the development of transplant renal arteriopathy in humans.

Transplant renal arteriopathy (TRA) is a major obstacle to the long-term survival of human renal allografts. Tenascin (TN) is an extracellular matrix glycoprotein associated with cell growth and differentiation. We investigated TN expression in intrarenal arteries with TRA, in association with cellular components, with phenotypic expression of smooth muscle cells (SMC) and with fibronectin expression. Ten renal allografts that had been removed due to rejection were available. Monoclonal antibodies against SMC, macrophages, T cells, B cells, fibronectin, and TN were used. In the early stages, medial SMC showed a de-differentiated phenotype and the neointima consisted largely of T cells and macrophages. At these stages, increased expression of TN was observed in the media. In later stages, the neointima consisted almost entirely of SMC of a differentiated phenotype and no TN expression was found. Up-regulation of TN may play a role in the migration and phenotypic modulation of SMC at an early stage of TRA in humans.

Actins↗
PubMed1995

Spinal pathways of nociceptive information evoked by short CO2 laser pulse in rats.

This study aimed to determine the relative importance of several spinal ascending pathways in conveying laser pulse activated A-delta and C-fiber information by using both awake and anaesthetized rats. Rats were subjected to spinal cord lesion (between T10-T12) under general anesthesia. Three types of lesion were made; dorsal column (DC, n = 4), bilateral dorsal lateral funiculus lesion (DLF, n = 4), and bilateral ventral quandrant lesion (VQ, n = 3). In normal awake rats, a laser pulse (10 watts intensity and 10 ms duration) applied to the plantar surface of the hind foot could evoke two prominent cortical potentials, one early and one late component in the contralateral somatosensory cortex. The early negative potential had a latency of 52.8 +/- 6.8 ms (mean +/- S.E.M.) and amplitude of 0.066 +/- 0.011 mV, while the late component had a latency of 264.6 (4.6 ms and an amplitude of 0.143 +/- 0.014 mV. After DC lesion, only latency of the early response was significantly lengthened (p < 0.05). Latency and amplitude of the early response were reduced markedly (p < 0.01) after bilateral DLF lesion. The change in the late response was significant only in the latency (p < 0.01). The peak amplitude of both early and late responses decreased significantly (p < 0.01) after VQ lesion. In rats with acute preparation, both of the DC and DLF lesions had no significant effect on the laser-evoked late response. The lesion of the VQ completely eliminated the late response.

Afferent Pathways↗
PubMed1993

[Obliterative arteriopathy in renal transplantation: an immunocytochemical analysis].

Obliterative arteriopathy is one of the major obstacles to long-term survival of human renal allografts. However, the cellular composition of obliterative arteriopathy has been incompletely characterized. We have performed immunocytochemical investigations of cellular components of obliterative arteriopathy and also investigated immunophenotypic features of proliferating smooth muscle cells in these lesions. Three renal allografts that had been removed due to rejection were available for this study. Time lapse between transplantation and removal of the renal allograft in these patients was 2 months, 5 months, and 4 years and 9 months, respectively. Tissue blocks cut from these renal allografts were fixed in methanol-Carnoy's fixative, and embedded in paraffin. Serial sections from each block were cut and used for histopathological and immunocytochemical studies. Monoclonal antibodies used for this study were as follows: anti-muscle actin antibody, HHF35; anti-smooth muscle actin antibody, CGA7; anti-vimentin antibody; anti-desmin antibody; anti-macrophage antibody, HAM56; and anti-Factor VIII-related antigen antibody. In all the allografts, obliterative arteriopathy was observed in the interlobular and arcuate arteries. In an early stage of proliferative lesions (2 months), the hyperplastic intima consisted largely of macrophages, intermixed with smooth muscle cells. At this stage, smooth muscle cells at the luminal site stained positive with HHF35, but negative with CGA7. In older lesions (5 months, 4 years and 9 months), however, the thickened intima consisted almost entirely of smooth muscle cells. At this stage, smooth muscle cells stained positive with both HHF35 and CGA7.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Peroxisomes in Saccharomyces cerevisiae: immunofluorescence analysis and import of catalase A into isolated peroxisomes.

To isolate peroxisomes from Saccharomyces cerevisiae of a quality sufficient for in vitro import studies, we optimized the conditions for cell growth and for cell fractionation. Stability of the isolated peroxisomes was monitored by catalase latency and sedimentability of marker enzymes. It was improved by (i) using cells that were shifted to oleic acid medium after growth to stationary phase in glucose precultures, (ii) shifting the pH from 7.2 to 6.0 during cell fractionation, and (iii) carrying out equilibrium density centrifugation with Nycodenz containing 0.25 M sucrose throughout the gradient. A concentrated peroxisomal fraction was used for in vitro import of catalase A. After 2 h of incubation, 62% of the catalase was associated with, and 16% was imported into, the organelle in a protease-resistant fashion. We introduced immunofluorescence microscopy for S. cerevisiae peroxisomes, using antibodies against thiolase, which allowed us to identify even the extremely small organelles in glucose-grown cells. Peroxisomes from media containing oleic acid were larger in size, were greater in number, and had a more intense fluorescence signal. The peroxisomes were located, sometimes in clusters, in the cell periphery, often immediately adjacent to the plasma membrane. Systematic immunofluorescence observations of glucose-grown S. cerevisiae demonstrated that all such cells contained at least one and usually several very small peroxisomes despite the glucose repression. This finding fits a central prediction of our model of peroxisome biogenesis: peroxisomes form by division of preexisting peroxisomes; therefore, every cell must have at least one peroxisome if additional organelles are to be induced in that cell.

Acyl-CoA Oxidase↗
PubMed1991

[Patent urachus associated with abdominal abscess: report of a case].

A case of the patent urachus associated with abdominal abscess was reported. A 44-year-old woman was consulted to our clinic with the complaints of bladder irritability and discharge from the navel on October 27, 1987. A fist-sized tumor around the umbilicus was pointed out and the cystography from the umbilicus demonstrated that the contrast medium reached to the urinary bladder. The cystoscopy showed the protruded lesion on the dome of the bladder. The pre-operative diagnosis was patent urachus. She received resection of the urachus on November 11, 1987. The pathological finding was pyogenic granuloma of the urachus due to chronic inflammation.

Abdominal Muscles↗
PubMed1991

[Chemical studies of coumarins from Glycyrrhiza uralensis Fisch].

This paper reports the isolation and identification of eight crystalline substances (I, II, III, IV, V, VI, VII, VIII) from the root of Glycyrrhiza uralensis Fisch. Besides the known compounds liquiritin, hexacosance, beta-sitosterol, licoricone liquiritigenin and etc, a new constituent, named neoglycyrol was obtained by sillica gel and polyamide column chromatographic method. Its chemical structure was elucidated by means of chemical and spectrometric analysis (UV, IR, NMR and MS). Neoglycyrol, C21H18O6, yellow needles with mp 263.5-265 degrees C, possesses one methoxyl, one isopentenyl and two hydroxyls. Its diacetate derivative is C25H22O8 with mp 202-203.5 degrees C. Its dimethyl ether derivative is C23H22O6 with mp 207-208.5 degrees C. Its structure was found to be VII.

Coumarins↗
PubMed1984

Purification and characterization of methylmalonyl-CoA mutase from Ascaris lumbricoides.

Methylmalonyl CoA mutase from Ascaris lumbricoides has been purified to homogeneity. The mutase is homogeneous as judged by equilibrium sedimentation and polyacrylamide gel electrophoresis. The worm mutase is a glycoprotein with a mol. wt of 147,000 +/- 3500 composed of two identical or very similar subunits. One molecule of adenosylcobalamin is tightly bound to each subunit. The mutase from Ascaris is not affected by exposure to light, cyanide ion or intrinsic factor and is not inhibited by iodoacetate and rho-hydroxymercuribenzoate. The kinetic constants of this mutase for (R,S)methylmalonyl CoA are Km = 4.2 X 10(-5) M and Vmax = 4.73 mumol/mg/min.

Amino Acids↗