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Biomedical subjects

S J Lin

Publications and source records attributed to S J Lin.

At least 181 records · Page 10Linked to original sources
PubMed1985

Lack of influence of aluminum hydroxide on the bioavailability and beta-adrenoceptor blocking activity of propranolol.

Plasma concentrations of propranolol and the changes of exercise induced heart rate were determined in 6 healthy subjects. An amount of 40 mg of propranolol was given alone or in combination with 30 ml of aluminum hydroxide gel. Neither the bioavailability nor the beta-adrenoceptor blocking activity of propranolol was significantly changed by concurrent administration of aluminum hydroxide gel. There is no need to increase the propranolol dose when aluminum hydroxide gel is administered concurrently.

Adult↗
PubMed1984

Enzymatic preparation of seasoning 5'-nucleotides from baker's yeast.

Chemical phosphorylation with sodium trimetaphosphate (STMP) as a modifying agent was used to prepare functional protein isolate and dissociated nucleic acid (mostly RNA) from baker's yeast. The majority of protein-RNA complex in the disintegrated yeast cells was first extracted with an aqueous alkaline solution (pH 12, 40 degrees C) followed by phosphorylation with STMP under the same condition for 6 hrs. An apparent dissociation of protein-RNA complex occurred due to the covalent attachment of anionic phosphate groups onto yeast protein molecules. The nucleic acid residued in the supernatant after removal of modified protein isolate by isoelectric precipitation was recovered by reprecipitating at pH 2 followed by converting it to 5'-nucleotides with malt rootlets 5'-phosphodiesterase as well as red marine algal adenylate deaminase. This coherent process provided a preparation of food-usable functional protein isolate and 5'-nucleotides from baker's yeast.

AMP Deaminase↗
PubMedDate not supplied

Salvia miltiorrhiza inhibits intimal hyperplasia and monocyte chemotactic protein-1 expression after balloon injury in cholesterol-fed rabbits.

Antioxidants that prevent low density lipoproteins (LDL) from oxidation may inhibit atherosclerosis and post-angioplasty restenosis. Salvia miltiorrhiza (SM) has been shown to inhibit LDL oxidation and reduce atherosclerosis in cholesterol-fed rabbits. The effects of SM on neointimal hyperplasia and monocyte chemotactic protein-1 (MCP-1) expression after balloon injury were studied. Male New Zealand white rabbits were fed a 2% cholesterol diet together with daily SM (4.8 gm/kg body wt.) treatment (SM; n=10) or without SM as a control (C; n=9) for 6 weeks. Probucol-treated (0.6 gm/kg body wt.) rabbits (P; n=9) were used as a positive control group. A balloon injury of the abdominal aorta was performed at the end of the third week. Aortas were harvested at the end of 6 weeks. The plasma cholesterol levels were lowered in SM group. The neointimal hyperplasia in abdominal aortas was significantly inhibited in SM group [neointima/media area ratio: 0.63+/-0.05 (SM) versus 0.78+/-0.05 (C); P < 0.05] and in P group [0.45+/-0.02 (P) versus 0.78+/-0.05 (C); P < 0.05] when compared with C group. SM treatment significantly reduced MCP-1 mRNA and protein expression in balloon-injured abdominal aorta. These inhibitory effects on intimal response after balloon injury might be attributed to antioxidant capacity and cholesterol lowering effect of SM. SM treatment may offer some protection against post-angioplasty restenosis.

Angioplasty, Balloon↗
PubMedDate not supplied

Skin cancer recognition by computer vision.

Automatic detection of several features characteristic of basal cell epitheliomas is described. The features selected for this feasibility study are semitranslucency, telangiectasia, ulcer, crust, and tumor border. Image processing methods used in this study include frequency analysis of the Fourier transform of the image, the Sun-Wee texture analysis algorithm, and several other image analysis techniques suitable for skin photographs. This image analysis software is designed for use with AI/DERM, an expert system that models diagnosis of skin tumors by dermatologists.

Basal Cell Carcinoma↗
PubMedDate not supplied

Voxel-based texture mapping for medical data.

In computerized image and graphic applications, texture mapping is one of the most commonly used methods to improve the realism or to enhance the visual effect of object rendering without too much increase in computational complexity. The conventional method usually has to transfer three-dimensional (3D) object to the polygonal structure, and is computationally expensive. As the medical data are mostly in voxel format, the polygonal structure is not efficient or requires more complicated mechanism in retrieving the internal information of medical data. In this paper, we propose a new texture mapping method, based on flattening a chain-coded 3D surface, to handle the voxel-based data directly. The method flattens the 3D object surface onto a two-dimensional (2D) plane and then uses 2D metamorphosis to generate the correspondences between object surface and texture image. Therefore, polygon transformation is no longer necessary and texture mapping is handled with inexpensive 2D morphing. More importantly, the internal information of medical data can be easily preserved and utilized further. Experimental results have shown the effectiveness and efficiency of the proposed algorithm.

Algorithms↗
PubMedDate not supplied

Effect of two-round Ficoll-Hypaque density gradient centrifugation on lymphocyte subsets and natural killer activity of umbilical cord blood mononuclear cells.

Umbilical cord blood (CB) mononuclear cells (MNCs) obtained from Ficoll-Hypaque density gradient centrifugation (FDGC) are frequently contaminated with erythrocytes and nucleated erythroid precursors. The authors investigated the effect of two-round (2-r) FDGC on lymphocyte subsets and natural killer activity of CB and adult peripheral blood (APB) MNCs, in comparison with those obtained from conventional one-round (1-r) separation. The percentage of CD45-expressing CB MNCs was greatly increased after the second density step (p < .01), indicating the efficacy in purification. The percentages of CD3/CD4, CD3/CD8, and CD16/56 double-positive staining CB MNCs were significantly increased after 2-r FDGC, as compared to those after 1-r separation. However, the percentages of CD34+ stem cells and CD19+ B cells were not affected by 2-r FDGC. MNCs obtained from 2-r FDGC had higher natural killer (NK) activity than did MNCs obtained from 1-r separation (p < .01). In contrast, 2-r FDGC did not affect lymphocyte subsets and NK activity of APB MNCs as compared to 1-r FDGC. Thus, 2-r FDGC are recommended to obtain CB MNCs for flow cytometric analysis and NK cytotoxicity assays.

Cell Survival↗
PubMedDate not supplied

Determination of thiocyanate anion by high-performance liquid chromatography with fluorimetric detection.

A simple and sensitive high-performance liquid chromatographic (HPLC) method was established for the trace determination of thiocyanate anion as a fluorogenic derivative. The method is based on the chemical derivatization of thiocyanate anion with 3-bromomethyl-7-methoxy-1,4-benzoxazin-2-one. The resulting derivative was separated by a Nova-Pak C18 reversed-phase column. Optimization conditions for the derivatization of thiocyanate anion were investigated by HPLC with fluorimetric detection. The linear range for the quantitation of thiocyanate anion was 1-0.05 nmol in 0.1 mL of sample; the detection limit (with a signal-to-noise ratio of 5) of a 20-microL injected aliquot was approximately 3.3 +/- 1.2 fmol. Application of the method to the analysis of thiocyanate anion in saliva and plasma proved to be feasible.

Anions↗
PubMedDate not supplied

Macromolecular transport across arterial and venous endothelium in rats. Studies with Evans blue-albumin and horseradish peroxidase.

Atherosclerotic lesions are characterized by lipid infiltration in regions with high rates of endothelial cell turnover. The present investigation was designed to elucidate the route of macromolecular transport across vascular endothelium. The aorta and vena cava of male Sprague-Dawley rats were perfusion-fixed after the intravenous injection of Evans-blue albumin (EBA) or horseradish peroxidase (HRP). Fluorescence microscopic examination of en face preparation of the aorta stained with hematoxylin allowed the identification of endothelial cells that underwent mitosis, together with the localization and quantification of fluorescent spots for EBA leakage. The HRP specimens were subjected to histochemical treatment, and HRP leakage was seen as brown spots under the light microscope. Silver nitrate stain was added in both EBA and HRP studies to outline cell boundaries and to visualize stigmata, stomata, and dead cells. In the aorta, almost every dividing cell showed junctional leakage to albumin and HRP, with clustering of leaky spots around the branch orifices. Time-dependent studies showed gradual increases in the diameter and number of these heterogeneously sized leaky spots, which finally fused to sizes corresponding to the "blue areas" for EBA or "brown areas" for HRP. Compared with arteries, veins had fewer mitotic cells, but more dead cells and diffuse dye-staining areas, indicating a more rapid transport of macromolecules. The leaky spots in the artery were associated mainly with mitotic cells, dead cells, and stigmata, whereas those in the vein occurred primarily at regions with dead cells. These results suggest that the preferential association of the enhanced transport of macromolecules with mitosis in the arterial as compared to venous endothelium and the differential behavior in transmural transport between arteries and veins may form the basis for the predilection of atherosclerosis in arteries.

Animals↗
PubMedDate not supplied

Role of dying endothelial cells in transendothelial macromolecular transport.

There are focal areas in the aorta with an enhanced endothelial permeability to macromolecules, as indicated by the focal uptake of the protein-binding azo dye Evans blue in vivo. These areas exhibit high rates of endothelial cell turnover and a number of structural characteristics in en face endothelial morphology. To determine the relationship of endothelial cell death to macromolecular leakage at the level of individual endothelial cells, thoracic aortas of 12 adult male Sprague-Dawley rats were studied at 3 to 5 minutes after intravenous administration of Evans blue-albumin (EBA). Leakage of EBA around individual endothelial cells in en face preparations of the aorta was visualized by fluorescence microscopy. Dying or dead endothelial cells were identified by indirect immunoglobulin G (IgG) immunocytochemistry. Although endothelial cell death is uncommon in normal aortic endothedium (i.e., an average frequency of 0.48%), a high percentage (63%) of IgG-containing dying or dead endothelial cells was found to be associated with EBA leakage. These dying or dead endothelial cells were responsible for 37% of total EBA leaky foci. The results suggest that, in addition to mitotic endothelial cells, the dying or dead endothelial cells also make significant contributions to the local enhancement in aortic endothelial permeability. The present findings lend further support to the "cell turnover-leaky junction" hypothesis for the localization of atherosclerosis.

Albumins↗
PubMedDate not supplied

Transendothelial transport of low density lipoprotein in association with cell mitosis in rat aorta.

Atherosclerosis is characterized by focal areas of lipid accumulation and intimal smooth muscle cell proliferation in large arteries. In vivo studies on rat aorta with Evans blue-albumin conjugate (EBA) have shown that there are preferential sites of increased permeability with an increased uptake of the conjugate. It has been shown that these blue areas are associated with a high endothelial cell turnover rate and an enhanced permeability to lipids. In a previous study, we demonstrated that 99% of endothelial cells in the mitotic (M) phase as identified by hematoxylin staining of the dividing nuclei exhibited EBA leakage and that these dividing cells accounted for 30% of all leakage sites. In the present study, experiments were performed on the thoracic aortas of 10 adult male Sprague-Dawley rats to determine the statistical frequency of isolated leaks to Lucifer yellow-low density lipoprotein conjugate (LY-LDL) at the level of individual cells and to assess the relationship of such leaks to the cell turnover processes. Leakage of LY-LDL around individual endothelial cells was visualized by fluorescence microscopy, and cells in mitosis on the same specimens were identified by hematoxylin staining. Although endothelial cell mitosis is infrequent (0.034%), 80% of dividing cells in the M phase were associated with LY-LDL leakage. These dividing cells accounted for 45% of all leakage spots. These findings lend support to our recent hypothesis that transiently open junctions surrounding the endothelial cells undergoing cell turnover provide pathways through which LDL enters the subendothelial space, resulting in lipid accumulation.

Animals↗
PubMedDate not supplied

Hodgkin's disease in a child with hyperimmunoglobulin E syndrome.

A 10-year-old boy with hyperimmunoglobulin E (HIE) syndrome was admitted to the hospital due to intermittent fever and a growing neck mass noted for 3 months. He had had chronic eczema and recurrent skin infections since infancy. At age 8, the diagnosis of HIE was established when a pneumatocele was found in the presence of extremely elevated serum IgE levels (7842 IU/mL). He also had defective T-lymphocyte function, manifested by cutaneus anergy, as well as abnormal proliferative response to mitogenic stimuli. Chemotactic function of neutrophils was normal. Pathological examination of the lymph node disclosed Hodgkin's disease (nodular sclerosis). A high index of suspicion for lymphoma should be given in patients with HIE syndrome who present with lymph node enlargement.

Child↗
PubMedDate not supplied

A follow-up study of systemic-onset juvenile rheumatoid arthritis in children.

We analyzed the clinical and laboratory features, treatment, and course of twenty-one children with systemic-onset juvenile rheumatoid arthritis (S-JRA) encountered at our institution over the past ten years. There were eleven boys and ten girls. The mean age at onset was 11.6 +/- 4.2 years. The mean duration of symptoms prior to diagnosis was 5.5 +/- 1.7 months, and the mean follow-up period was 45.7 +/- 9.5 months. The clinical and laboratory features at presentation were similar to previous reports, except that peripheral blood smear revealed toxic granulation of neutrophils in 60% of our patients. Although systemic manifestation could be readily controlled by non-steroidal anti-inflammatory drugs (NSAIDs) with or without additional steroids, nine patients suffered from chronic arthritis (duration > 6 months) requiring disease-modifying anti-rheumatic drugs (DMARDs). Of the nine children with chronic arthritis, six (67%) had a monocylic systemic course, and seven (78%) had polyarticular disease (five or more joints affected) at the disease onset. Five patients developed severe destructive polyarthritis, with persistent anemia, thrombocytosis, elevated serum C-reactive protein (CRP) levels, and marked functional limitation during follow-up. One of the five patients with severe arthritis developed systemic lupus erythromatosis after 8-year follow-up, and died of sepsis. Our study indicated significant morbidity in children with S-JRA in Taiwan.

Adolescent↗
PubMedDate not supplied

Intraarticular triamcinolone hexacetonide injection in children with chronic arthritis: a survey of clinical practice.

To assess the efficacy of the intraarticular steroid(IAS) injection in the management of arthritis and the possible related complications in children with chronic arthritis. We evaluated 11 children of chronic arthritis (4 girls and 7 boys), age of onset ranged from 2-13.6 years, who had persistent arthritis treated with IAS from November 1994 to June 1997. The results of injections showed that the beneficial effect was noted within one day to 2 weeks without significant adverse reactions, remission exceeding 6 months was seen in 10 of 11 patients (in 14 of 18 joints). According to subgroups of chronic arthritis, the remission rate of IAS injection in children with pauciarticular arthritis reached 100%. A significant fall in C-reactive protein (CRP) between pre- and post-IAS injection (p = 0.03), but there were no differences in hemoglobin (Hb), white blood cells (WBCs), thrombocytes (Plts), erythrocyte sedimentation rate (ESR) and osteocalcin level. No injection-related complications were found. In conclusion, the IAS injection was an effective and safe treatment in children with chronic arthritis with no obvious complications especially in pauciarticular arthritis.

Adolescent↗