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Biomedical subjects

L Ye

Publications and source records attributed to L Ye.

At least 91 records · Page 5Linked to original sources
PubMed1997

Molecular and epidemiological studies of Werner syndrome in the Japanese population.

Werner syndrome (WS) is an autosomal recessive genetic disease characterized by many age-related features. The gene responsible for WS (WRN) has been isolated and contains a helicase domain, but its function is unknown. Six different mutations throughout the WRN gene have been reported in the Japanese population. We have studied whether patients with a specific mutation exhibit distinct phenotypes from others. Fourteen patients with different mutations showed almost the same signs and symptoms and, therefore, the C terminal part of the product appears to be crucial for its functions, although other parts may be important as well. Haplotype analyses using 13 microsatellites covering the 2.8-3.0 cM WRN region showed that two out of six different mutations had founder chromosomes. These two founder chromosomes may be evenly distributed throughout the western part of Japan, suggesting that these mutations go back to a time earlier than 1400 years ago.

Chromosome Mapping↗
PubMed1997

First trial of home ECG and blood pressure telemonitoring system in Macau.

OBJECTIVE: To determine the feasibility of home monitoring of patients with cardiac disease or hypertension. METHODS: An improved home electrocardiographic and blood pressure telemonitoring system linked to a central workstation was tested in 10 patients in Macau for 3 months. RESULTS: The total number of connections was 1377. Of the automatic alarm connections, 32.5% were false positive, with the percentage of false positives ranging from 7.6 to 54.6 for different patients. Both patients and physicians found the system easy to use. CONCLUSIONS: Further investigation is required to match the number of patients with the system capacity. A more robust dysrhythmia detection algorithm is needed to reduce the number of false alarms. Nevertheless, the results were sufficiently good that the trial is being expanded.

Blood Pressure Determination↗
PubMed1997

Growth factor and cytokine-regulated hyaluronan-binding protein TSG-6 is localized to the injury-induced rat neointima and confers enhanced growth in vascular smooth muscle cells.

Hyaluronan (HA) and HA-binding proteins have been implicated in a diverse array of biological processes, including development, tissue repair, and tumor invasion. However, the role of HA and HA-binding proteins in atherosclerosis and restenosis is poorly understood. PS4 (TSG-6) is a HA-binding protein expressed by cultured vascular smooth muscle cells (SMCs) in response to serum and growth factor stimulation. To delineate a possible role for TSG-6 in vascular disease progression, we have characterized its expression in cultured SMCs and in a rat vascular injury model, and we have studied the effect of constitutive overexpression of TSG-6 on SMC behavior. We found that interleukin-1 (IL-1) but not tumor necrosis factor or interleukin-6 was able to stimulate TSG-6 expression in SMCs. The IL-1 pathway could be distinguished from the growth factor pathway by its insensitivity to protein synthesis inhibitors. Furthermore, epidermal growth factor, fibroblast growth factor-1, and transforming growth factor-beta1 were all capable of augmenting maximum IL-1-induced expression of TSG-6. To gain further insight into the function of TSG-6 in SMCs, we examined the effect of constitutive overexpression of TSG-6 on these cells. We found that TSG-6-overexpressing cells grew >50% faster than control cells. Furthermore, this growth advantage became more evident in the absence of serum growth factors, with an average increase in cell number of 118% over control cells after 6 days. Consistent with these in vitro data, we observed intense immunostaining for TSG-6 in proliferating SMCs in the rat neointima after injury, whereas only an occasional cell was positive for TSG-6 in the medial layer and in nonballooned arteries. We conclude that the expression of TSG-6 is tightly controlled by growth factors and cytokines via two distinct pathways in SMCs and that overexpression of TSG-6 confers a growth advantage to these cells.

Animals↗
PubMed1997

A home electrocardiography and blood pressure telemonitoring system.

A home electrocardiography (ECG) and blood pressure telemonitoring system for cardiac patients was installed in the Macau region. The monitoring centre was established in the emergency unit at the Government Hospital of Macau. The first users were 10 cardiovascular patients selected by a physician. The average age of these users was 61 years (range 30-78). The results of a three-month trial showed that the system was easy to operate and technically reliable. It was found to be helpful for cardiac patients. The most significant problem during the trial was electrical noise from the ECG electrodes.

Adult↗
PubMed1997

Serum inhibits tight junction formation in cultured pigment epithelial cells.

PURPOSE: These experiments were designed to characterize tight junction formation by retinal pigment epithelial (RPE) cells in vitro and to compare the effects on this process of hormonally defined medium (HDM) and serum-containing medium. METHODS: Formation of RPE tight junctions was analyzed in freshly isolated rat RPE cells maintained either in HDM or serum-containing medium. Junctions were evaluated functionally by measuring transepithelial electrical resistance (TER) and permeability and structurally by immunolocalization of the junction-associated actin microfilaments. Calcium dependency of the junctions was determined by reducing media calcium concentration. RESULTS: RPE cells cultured in serum-free HDM developed calcium-dependent tight junctions, which exhibited TER levels > 150 omega cm2 and low paracellular permeability. Serum-containing media inhibited tight junction formation as indicated by significant reductions in TER and increases in permeability. Junction-associated actin microfilaments and cell density were unchanged. CONCLUSIONS: Tight junction formation by RPE cells is inhibited by serum. This activity may play an important role in responses of the RPE layer to injury, contributing to the pathologic progression of blood-retinal barrier dysfunction.

Animals↗
PubMed1996

Narrowing the position of the Werner syndrome locus by homozygosity analysis-extension of homozygosity analysis.

Werner syndrome (WS) is an autosomal recessive disorder characterized by the premature occurrence of many age-related features. Previously, the WS gene (WRN) was mapped between D8S131 and D8S87, in an 8.3-cM interval. In this study, regions of homozygosity in 36 WS patients from inbred families were searched for by genotyping for 35 dinucleotide repeat polymorphic markers to narrow down the WRN critical region. The region most consistently homozygous in these patients was between the D8S1219/D8S1220 cluster and D8S278, within a 4.4-cM interval. For 16 markers mapped in this interval, 24 WS patients (22 Japanese patients and 2 Caucasian patients) in whom consanguinity failed to be proved were also genotyped, under the assumption that some of these patients might still be from consanguineous marriages. The data were analyzed by Fisher's exact test with a 2 x 2 contingency table for the 22 Japanese patients, excluding the 2 Caucasian patients. The frequencies of homozygosity in the 22 patients at 10 of 16 markers tested were significantly higher than those detected in the general population. Analysis of homozygosity patterns indicated that the region most consistently homozygous was between D8S1445 and D8S278. Thus the WRN locus is most likely between the two markers D8S1445 and D8S278, in a 1.6-cM interval.

Asian People↗
PubMed1996

Artificial antibodies to corticosteroids prepared by molecular imprinting.

BACKGROUND: Molecular imprinting can be used to prepare antibody and receptor mimics. We have previously shown that acrylic acid polymers can be imprinted to recognize a variety of small molecules. Here, we show that molecularly imprinted polymers (MIPs) can selectively recognize steroid structures. RESULTS: Artificial antibodies mimicking the binding performance of natural anti-corticosteroid antibodies have been prepared using a molecular imprinting protocol with either cortisol or corticosterone as a target molecule. The binding characteristics of a range of structurally related ligands were estimated using a form of radioimmunoassay. The antibody mimics were found to be highly selective for the ligands used in their preparation and the cross-reactivities with compounds of related structure resembled those obtained in studies with natural antibodies. CONCLUSIONS: The binding properties of MIPs, prepared against corticosteroids, exhibit strong similarities to those of naturally raised antibodies. Such artificial antibodies may serve as a useful complement to their natural counterparts in studies of corticosteroid binding events.

Adrenal Cortex Hormones↗
PubMed1996

[Linkage mapping].

Explore the source record for details and available documents.

Chromosome Mapping↗
PubMed1996

[New ellagic glycosides and known triterpenoids from Duchesnea indica Focke].

Two new ellagic glycosides, named ducheside A and ducheside B, have been isolated from Ducheside indica Focke. Their structures were established as 3'-O-methyl-ellagic acid-4-O-beta-D-xylopyranoside (I), 3'-O-methyl-ellagic acid-4-O-alpha-L-arabinofuranoside (II), respectively, on the basis of chemical method and spectral analysis. In addition, four known compounds were isolated and identified as 3 beta-hydroxylurs-12-en-28-oic acid (III), 2 alpha, 3 beta, 19 alpha-trihydroxylurs-12-en-28-oic acid (IV), 2 alpha, 3 beta, 19 alpha-trihydroxylurs-12-en-28-oic acid 28-O-beta-D-glucopyranoside (V), 2 alpha, 3 alpha, 19 alpha-trihydroxylurs-12-en-28-oic acid 28-O-beta-D-glucopyranoside (VI). Compounds IV, V, VI were isolated for the first time from Duchesnea genus.

Molecular Structure↗
PubMed1995

Genetic association between chromosome 8 microsatellite (MS8-134) and Werner syndrome (WRN): chromosome microdissection and homozygosity mapping.

Werner syndrome (WRN) is an autosomal recessive disorder characterized by premature aging that has been mapped to the short arm of chromosome 8, 8p11.2-p12. To refine the genetic map around the WRN region, we have isolated eight microsatellites for this region from a microdissection library. We typed members of Japanese families with WRN on the basis of homozygosity mapping analysis. There was no obligate recombination between the WRN locus and microsatellite clone, MS8-134 (D8S1055). The maximum lod score was 20.28 at theta = 0.00. Alleles for MS8-134 showed association with WRN in a case-control study (OR = 3.55, 95% CI 1.56-8.07, P < 0.01). Such microsatellites from a microdissection library of the definite chromosome region may be useful for positional cloning of the WRN gene.

Base Sequence↗