Search PubMed⌕ Search

Biomedical subjects

L Sun

Publications and source records attributed to L Sun.

At least 415 records · Page 23Linked to original sources
PubMed1995

[Effect of Dendrobium nobile Lindl. on gastric acid secretion, serum gastrin and plasma somatostatin concentration].

The patients with chronic superficial gastritis were perfused in the stomach with 20 g of Dendrobium nobile to observe the variations in gastric acidity output, serum gastrin and plasma somatostatin concentration. The result showed a significant increase in both acidity output and serum gastrin concentration (P < 0.01). No significant change occurred in plasma somatostatin concentration (P > 0.05).

Adult↗
PubMed1995

[Effect of tetramethylhyrazine on proliferation of human fetal mesangial cells].

Tetramethylhyrazine (TMP) 0.6 and 1.2 mmol were added to human fetal mesangial cell (MC) cultures for 6 days, and the amounts of MC (cells/ml) were 37580 +/- 3475 and 27350 +/- 3418 respectively, significantly lower than that 71850 +/- 5108 in control (P < 0.05). The 3H-TdR incorporation by the MC with corresponding TMP were 1017 +/- 201 and 583 +/- 271, also significantly lower, than that 3575 +/- 306 in control (P < 0.01). After adding the TMP (1 mmol) to the cultures, the IL-6 bioactivity were 2118 +/- 215 that were markedly lower than those in controls (4128 +/- 351, P < 0.01). It revealed that the TMP inhibited the growth of MC and the mechanism of its inhibition might be due to that TMP could reduce the IL-6.

Cell Division↗
PubMed1995

[Evaluation of radiographic diagnosis on osteoarthrosis of the temporomandibular joint].

84 cadavers' temporomandibular joints were used to compare the results shown in standard lateral tomographs and Schuller's position films with gross views on the bone and cartilage changes. The results and conclusions were as follows: (1) The positive rates of the radiographic evidences were associated with the degrees of the macroscopic lesions. The more severe the macroscopic lesion, the higher the positive rate of radiographic evidence. (2) The sensitivity of radiographic examination was positively correlated with the extent of the macroscopic lesion. So, the negative predictive value was. However, the specificity and the positive predictive value of the radiographic examination were negatively correlated with macroscopic change index. It has been found that the more the extent of osteoarthrosis changes, the higher the sensitivity of radiographic examination; the higher the negative predictive values, the higher the positive rate of radiographic evidence, and the lower the underdiagnosis rate was. Meanwhile, the more the extent of bone pathological changes in the joint, the lower specificity of the radiographic examination, and the lower the positive predictive values and the misdiagnosis is increased. (3) The radiographic diagnostic value based on the standard latreal tomographs of TMJ, Schuller's position films or based on the both methods was not satisfied. Its underdiagnosis rate was higher. Therefore, we suggest that multiple-layers lateral tomography should be widely used in clinical practice.

Aged↗
PubMed1995

ES-like cell cultures derived from early zebrafish embryos.

Pluripotent embryonic stem (ES) cell cultures provide an efficient method for genome manipulation with many applications in marine biotechnology. To develop this technology we have been working to derive fish ES cell lines for in vitro studies of embryo cell growth and differentiation and for the generation of transgenic fish. Zebrafish embryonal cell cultures were derived from blastula-stage embryos in LDF medium supplemented with fetal bovine serum, trout serum, trout embryo extract, selenium, insulin, and leukemia inhibitory factor. Cultures derived under these conditions on feeder layers of zebrafish embryonic fibroblasts possessed a diploid karyotype and exhibited an ES-like morphology with elevated levels of alkaline phosphatase enzyme activity. Injection of primary cell cultures derived from embryos of transgenic fish carrying neo produced chimeric fish detected by polymerase chain reaction analysis. Embryo cells cultured on poly-D-lysine substrate in the presence of retinoic acid or Buffalo rat liver cell-conditioned medium (BRL-CM) and a reduced serum concentration differentiated into neuronal cell types exhibiting elevated levels of acetylcholinesterase enzyme activity and expression of neurofilament and glial fibrillary acidic protein.

Acetylcholinesterase↗
PubMed1995

Feeder cell cultures for zebrafish embryonal cells in vitro.

Use of fibroblast cells derived from mouse embryos as feeder layers was one of the major steps leading to the establishment of pluripotential mouse embryonal stem (ES) cells in culture. In attempts to obtain a culture of pluripotential ES cells from zebrafish, a culture of fibroblastoid cells, designated zebrafish embryo fibroblast (ZEF), was established from early gastrula stage zebrafish embryos for use as feeder layer. In primary cultures initiated from early embryos of zebrafish without feeder layers, melanocytes appeared on the second day of culture. In contrast, melanogenesis was markedly suppressed in cocultures containing confluent monolayers of ZEF or Buffalo rat liver (BRL) cells. BRL cells are commonly used feeder layer cells for mouse ES cells. Suppression of melanogenesis was not observed in primary cultures initiated in medium containing human recombinant differentiation-inhibiting activity (DIA) or in medium conditioned by cultures of BRL feeder cells. Proliferation of zebrafish embryonal cells was enhanced significantly in cocultures with either feeder layer. Zebrafish embryonal cells cocultured short-term on ZEF and BRL feeder layers gave rise to melanocytes and formed embryoid body-like structures when removed from feeder layers and cultured in suspension, suggesting that the cells remained pluripotent in culture.

Animals↗
PubMed1995

Ultrastructural and radioautographic studies on DNA synthesis in Leydig cells on aging mouse testis.

A morphological observation and a radioautographic study were carried out to detect the ultrastructure and aging changes of DNA synthesis of the Leydig cells, whose structure has been observed and the area of the lipid droplets in the cytoplasm calculated. The observation by electron microscopy showed that Leydig cells contained abundant mitochondria and endoplasmic reticulum and that the area of the lipids in the cytoplasm changed with aging. Only little lipid droplets were found in embryonic and early postnatal stages, but they increased from postnatal two weeks onwards and no significant differences were found from 9 months to 21 months. The DNA synthesis in these cells was not vigorous at embryonic day 19, explored by light microscopic radioautography 1 hr. following a single injection of 3H-thymidine. The labeling index increased slightly before six months of age and reached its peak at 9 months. There was no significant difference found in the number of labelled cells from that time on. A relatively high level was maintained at adult and senescent periods. Our results demonstrate that the generation of the Leydig cells contained plentiful lipid droplets was vigorous at adult and senescence.

Aging↗
PubMed1995

Study on the DNA synthesis of pulmonary cells in aging mice by light microscopic radioautography.

The DNA synthesis and morphological changes of the pulmonary cells of 11 groups of mice from fetal day 16 to 22 months after birth were studied by light microscopic radioautography after 3H-thymidine incorporation. A detailed investigation was first carried out to determine the localization and the frequency of 3H-thymidine incorporation with the age-related change of pulmonary cells in the mouse lung. The results showed that the DNA synthesis of pulmonary cells changed with aging. The examination of radioautograms demonstrated that the activity of DNA synthesis of type 1 epithelial cells was very low, which reached the peak on the third day after birth, decreased gradually with aging, and lost the ability from postnatal 6 months onwards. On the other hand, the labeling indices of type 2 epithelial, interstitial and endothelial cells were the highest on the fetal day 16, then fell down with the developing of the lung, but increased again on the third postnatal day, and decreased gradually with age. These data provided the evidence that the DNA synthesis of type 2 epithelial, interstitial and endothelial cells were the largest on fetal day 16, then decreased with the developing of the lung due to aging.

Aging↗
PubMed1995

Mechanisms of platelet dysfunction and response to DDAVP in patients with congenital platelet function defects. A double-blind placebo-controlled trial.

To examine the impact of the underlying defective platelet mechanism on the response to 1-desamino-8-D-arginine vasopressin (DDAVP, Desmopressin), we studied the effect of intravenous infusion of 0.3 microgram/kg of DDAVP in a randomized double blind placebo-controlled trial with cross-over in 18 carefully characterized patients with congenital platelet defects (CPD) and BT > or = 9 min. Eleven patients had normal dense granule stores and normal thromboxane A2 (TxA2) production (Group I), 3 patients had normal granule stores but impaired TxA2 production (Group II), and 4 had delta-storage pool deficiency (Group III). DDAVP shortened BT at 50 min (DDAVP 14.6 +/- 2.2 vs placebo 19.6 +/- 2.3 min; n = 18; mean +/- SE; p = 0.003) and 4 h (17.0 +/- 2.2 vs 19.6 +/- 2.1 min, p = 0.055), and raised plasma FVIIIC and von Willebrand factor (vWF). At 50 min DDAVP shortened BT by > or = 5 min in 8 of 11 Group I patients (mean 9.7 +/- 1.3 vs 16.3 +/- 2.8 min; p < 0.008), 1 of 3 Group II patients (11.9 +/- 3.9 vs 17.7 +/- 6.6; p = NS) and none of Group III patients (mean 30 min both arms). Ten patients (Group I or II) were managed successfully during surgical procedures with DDAVP alone. We conclude that DDAVP shortens BT in majority of CPD patients with normal dense granule stores and suggest that BT response may be dependent on the underlying platelet defect. DDAVP is a useful modality in management of selected patients, particularly those with normal dense granule stores.

Bleeding Time↗
PubMed1995

[Protein analysis of 6 crude drugs and their processed products by polyacrylamide gel electrophoresis technique].

In this paper, the proteins in 6 crude drugs (Prunus persica; P. armeniaca; Dolichos lablab; Strychnos nux-vomica; Mylabris phalerata; Whitmania pigra) and their processed products were analysed by polyacrylamide gel electrophoresis technique, and the effect of different processing methods on the quantity and kind of protein was explored. Protein electrophorograms of 20 samples are drawn.

Animals↗
PubMed1995

Age-related changes of RNA synthesis in the lungs of aging mice by light and electron microscopic radioautography.

The changes of RNA synthesis and morphology in the lungs of aging mice from fetal day 16 to 22 months after birth were investigated by means of light and electron microscopic radioautography after 3H-uridine incorporation. Eleven groups of mice, each consisting of 3 animals from embryo day 16 to newborn, weanling, adult and senescent were used. Lung tissues were labelled in vitro with 3H-uridine and fixed, embedded, sectioned and radioautographed. The localization and number of silver grains were analyzed. The radioautograms revealed that all types of pulmonary tissue cells were labelled. The number of silver grains in respective cell types indicating the RNA synthesis changed with aging. The activity of RNA synthesis of type 1 epithelial cells increased gradually from the first day after birth, reached a peak at 1 week after birth, then decreased with aging. The RNA synthesis of type 2 epithelial, interstitial and endothelial cells increased gradually from fetal day 16, reached the peaks at 1 week after birth, then diminished with the developing of the lung due to aging.

Aging↗
PubMed1995

Change of water-soluble-protein, urea-soluble-protein and membrane intrinsic protein in human senile cataract.

PURPOSE: To analyze the change of water-soluble-protein (WSP), urea-soluble-protein (USP) and membrane intrinsic protein (MIP) in human senile cataract. METHODS: The water-soluble-fractions (WSF) were prepared basically according to the method of Kibbelear, et al. But in this study, 5 mmol/L B-mercaptoethanol was added to the buffer solution. The urea-soluble-fractions (USF) were prepared basically according to the method of Kibbelear, et al. Lens fiber cell membranes were purified basically according to the method of Russell, et al. SDS-PAGE were performed according to the procedure of Laemmili, et al. using resolving gel 13% and 3% stacking gel. RESULTS: The WSP was fractionated into HM+ alpha-, beta(1-3)- and gamma-crystallin components. In nuclear cataractous lenses HM+ alpha- and B-crystallin increase, while r-crystallin decrease. The USP from clear lenses contains mainly alpha beta chains of 22KD, whereas in cataractous lenses, especially in nuclear cataractous lenses, the relative amount of the 28- and 23KD polypeptide (the components of beta-crystallin) increased markedly. Lens fiber cell MIP, clear lens and cataract lens contained the main polypeptide of 27KD (MIP) and 23KD (MP23). CONCLUSION: The water-insoluble protein, whether in quantity or in quality, plays an important role in cataract formation.

Aged↗
PubMed1994

Expression of transforming growth factor beta type II receptor leads to reduced malignancy in human breast cancer MCF-7 cells.

The role of transforming growth factor (TGF) beta type II receptor in reversing the malignant phenotype of human breast cancer MCF-7 cells was examined. MCF-7 cells were insensitive to TGF beta 1 and expressed undetectable levels of cell surface TGF beta type I receptor (RI) and type II receptor (RII) by cross-linking with 125I-TGF beta 1. Stable transfection of a RII expression vector yielded 3 transfectants with varying levels of exogenous RII mRNA and protein levels. Expression of RII also increased TGF beta 1 binding to RI in all 3 clones. Proliferation of RII-positive clones was inhibited by exogenous TGF beta 1 in a dose-dependent manner, whereas the control clones remained TGF beta-insensitive. The RII transfectants were growth arrested in monolayer culture at saturation densities which were 41-66% of that of the Neo controls. They also showed reduced clonogenicity in soft-agarose. Tumorigenicity in ovariectomized, estrogen-supplemented nude mice was delayed in transfectants with low RII levels. Transfectants expressing high levels of RII showed a large reduction in tumorigenicity as well as a longer delay in tumor formation. Tumor growth was associated with loss of exogenous RII expression in transfectants. The results indicate that when systems for TGF beta signal transduction are intact, reconstitution of the TGF beta receptor system can lead to reversion of malignancy in cells lacking RII.

Animals↗
PubMed1994

Transmissibility of Pseudomonas cepacia infection in clinic patients and lung-transplant recipients with cystic fibrosis.

BACKGROUND: In patients with cystic fibrosis, infection with Pseudomonas cepacia is associated with poor outcomes. However, the extent of person-to-person transmission and the source of P. cepacia infection after lung transplantation are not well defined. Using DNA-based typing systems, we sought to determine the genetic relatedness of P. cepacia infection at one cystic fibrosis center. METHODS: We analyzed 65 P. cepacia isolates gathered over a period of eight years at a single cystic fibrosis center from 17 clinic patients and from 5 patients who underwent double-lung transplantation. The isolates were analyzed by ribotyping and chromosomal fingerprinting based on pulsed-field gel electrophoresis. RESULTS: Analyses of serial isolates revealed that each clinic patient and transplant recipient harbored a different P. cepacia clone that was persistent. In the transplant recipients, the preoperative and postoperative isolates were identical. In the two patients with disseminated infection after lung transplantation, isolates from multiple sites were identical and indicated clonal expansion of the previous respiratory P. cepacia strain. Pulsed-field gel electrophoresis proved both more discriminative and more practical than ribotyping as a means of defining the genetic relatedness of the P. cepacia isolates. CONCLUSIONS: Our serial analyses in patients with cystic fibrosis at one center found distinct strains of P. cepacia persistently infecting each patient and no evidence of person-to-person transmission of this organism. P. cepacia infection after lung transplantation was due to the persistence of the strain present before transplantation.

Bacterial Typing Techniques↗