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Biomedical subjects

Y Song

Publications and source records attributed to Y Song.

At least 433 records · Page 24Linked to original sources
PubMed1992

The identification and characterization of 125I-labelled iodomelatonin-binding sites in the duck kidney.

The melatonin-binding sites in membrane preparations of duck kidney were demonstrated by utilizing 125I-labelled iodomelatonin as a radioligand. Binding at these sites was found to be reversible, saturable, specific and of high affinity. Scatchard analysis of the specific binding revealed an equilibrium binding constant (Kd) of 44.6 +/- 4.4 pmol/l (n = 6) and a total number of binding sites (Bmax) of 6.43 +/- 0.60 fmol/mg protein (n = 6) at the mid-point of the light period (mid-light). The Hill coefficient approached 1.0, suggesting a single class of 125I-labelled iodomelatonin-binding site in the duck kidney. Diurnal variation in 125I-labelled iodomelatonin binding showed that the Bmax was 53.4% higher at mid-light than at mid-point of the dark period (P < 0.05), with no significant variation in Kd. The Kd value determined from kinetic analysis was 22.5 pmol/l in birds at mid-light, which was comparable with values determined from equilibrium studies. The order of pharmacological affinity for 125I-labelled iodomelatonin-binding sites in the duck kidney membrane preparations was: 2-iodomelatonin > melatonin > 6-chloromelatonin > 6-hydroxymelatonin > N-acetylserotonin >> 5-methoxytryptamine, 5-methoxytryptophol, 5-hydroxytryptamine, tryptamine, 1-acetylindole-3-carboxaldehyde, 5-hydroxyindole-3-acetic acid, L-tryptophan, 5-methoxyindole-3-acetic acid, 3-acetylindole, acetylcholine, epinephrine, norepinephrine and harmaline. The pharmacological characteristics indicated that 125I-labelled iodomelatonin-binding sites are highly specific for melatonin. Our finding of 125I-labelled iodomelatonin-binding sites in the kidney suggests that melatonin may regulate kidney function.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Mass culture of anchorage-dependent animal cells with newly born calf skin collagen membrane and microcarrier.

It was shown that collagen substrate enhances the growth as well as the differentiation of many cells in culture. Collagen is one of the major fibrous proteins of animal bodies and the pure collagen used in this experiment was extracted from the newly born calf skin by chemical and biochemical methods. The analytical results obtained by ion-exchange chromatography and electrophoresis showed that the main components of denatured collagen were alpha monomers and beta dimers. The collagen and denatured collagen membranes were prepared by coating their solution on peteri dishes. Various types of cells were cultured on these membranes after being irradiated by ultraviolet ray. The denatured collagen was proved a good substratum for culturing anchorage dependent cells. A denatured collagen (gelatin) microcarrier, GT-2 was obtained by cross-linking gelatin with glutaraldehyde in a suspension polymerization process. These microcarriers were used successfully to culture various anchorage-dependent cells such as Vero, CHO, Bowes and fish cells in varying scales, including T-flasks, spinning bottles, revolving bottles and 1.5 l and 20 l bioreactors.

Animals↗
PubMed1992

[A preliminary epidemiological survey of acute hemorrhagic conjunctivitis in Guangzhou during July to September in 1988].

An epidemic of acute hemorrhagic conjunctivitis (AHC) occurred in Guangzhou from July to September in 1988. The main clinical symptoms were feeling of foreign, smart pain, discharging ege, facial edema and conjunctival congestion. In some cases there were headache and fever. The patients recovered rapidly. Epidemiologic feature were that the incubation period of AHC is short, rapid spread, wide prevalence and high attack rate. Approximately 490000 cases of AHC are estimated to occur in Guangzhou from July to September in 1988, with the attack rate is about 79.5%. Most patients were 20 to 59 age group (72.3%). The highest age of patient was 79 years old. The lowest age of patient was 6 months old. Both etiologic and serologic studies showed that this outbreak of AHC was caused by EV70, and then developed a mixed epidemic of Cox A24 and EV70.

Adolescent↗
PubMed1992

[Clinical significance on expression of the ras gene product P21 in human cervical carcinoma tissues].

Using MAB-P21 as a probe, the expression of gene product was studied by immunohistochemical ABC method, ABC staining of gel electrophoresis and ELISA quantitative analysis. The expression of P21 was detected in 107 cases of uterine cervix tissues, among which 70 were cervical carcinoma, 30 were chronic cervicitis and 7 normal cervix. Experimental results showed that obviously positive expression was noted in the specimens of cervical carcinoma and its positive rate was 72.8% (51/70). It was observed that the expression of P21 varied with grades of cell differentiation in cervical carcinoma. The level of P21 expression in high differentiated type was higher than that of the middle and low differentiated types. On the contrary, there was no detectable ras P21 in the normal cervix tissue and only 2 cases of cervicitis expressed positively (2/30). The results of ABC staining of electrophoresis showed that there was a P21 special staining band in cervical carcinoma tissues. And the contents of P21 protein were higher in cervical carcinoma than in normal cervix and cervicitis (t test, P less than 0.001). The expression of P21 was considerably enhanced in malignant tissue as compared with that in benign lesion.

Adenocarcinoma↗
PubMed1992

[Noradrenaline fluorescence histochemical study on the locus coeruleus of kindling rat induced by coriaria lactone].

Fourteen male Wistar rats were divided into two groups. The experimental rats were injected with subconvulsive dosage of coriaria lactone (1 mg/kg) intramuscularly per 3.5 days. The controls were injected with normal saline. After 26 injections, the loci coeruleus of kindling rats were studied with the noradrenaline (NA) fluorescence histochemical technique at the time between seizures. The NA fluorescence could be clearly visualized under fluorescent microscope. The intensity of fluorescence was reflected by autoexposure-meter of the fluorescent microscope. The brighter the fluorescence, the shorter the autoexposure time. The intensity of NA fluorescence in the locus coeruleus of experimental animals was weaker than that of the controls. Since NA plays an inhibitory role in cerebral cortex, the decrease of NA, either induced by repeated injections of coriaria lactone or due to the time of sample taken after seizure, needs further study.

Animals↗
PubMed1992

[Histochemical and image-analytic study of the rat locus coeruleus during status epilepticus].

Twenty-four adult male Wistar rats were used in this study. Status epilepticus was provoked in 10 rats by embedding coriaria lactone particle into the left cerebral motor cortex. In the controls were embedded particles without coriaria lactone. After 6 h of continuous seizure, the locus coeruleus was studied with the noradrenaline (NA) fluorescence histochemical technique and enzyme histochemical test for monoamine oxidase (MAO). The intensity of NA fluorescence was detected with fluorescent microscope autoexposuremeter and analysed with MIAS-200 Image Analyser. The study group showed a parallel increase of NA fluorescence as compared with that of the control group by both measurements. NA plays an inhibitory role in the cortex. Our data suggest that the increase of NA in locus coeruleus may be due to the reduction of NA release from axon terminal. Reduction in inhibition could be one of the mechanisms of seizure activity. The intensity of MAO was detected with MIAS-200 Image Analyser. The regulation of monoamine metabolism by MAO in the central nervous system and the increase of MAO activity in the continuous seizure group may be induced by the accumulation of NA in the locus coeruleus soma.

Animals↗
PubMed1991

Isolation and structural elucidation of a novel type of ganglioside, deaminated neuraminic acid (KDN)-containing glycosphingolipid, from rainbow trout sperm. The first example of the natural occurrence of KDN-ganglioside, (KDN)GM3.

Rainbow trout sperm contained almost exclusively monoanionic ganglioside fraction as a major acidic glycosphingolipid. Two monoacidic gangliosides were isolated and purified in this study and designated as sperm ganglioside 1 and 2 (sg-1 and sg-2). The two gangliosides, sg-1 and sg-2, contained the same neutral sugars, galactose and glucose in molar ratio of 1:1 and no GalNAc except for the presence of N-acetyl-neuraminic acid (NeuAc) in sg-1 and deaminated neuraminic acid (KDN; 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid) in sg-2. The complete structures of these gangliosides were determined by a combination of methylation analysis, fast atom bombardment mass spectrometry, 400-MHz one- and two-dimensional 1H nuclear magnetic resonance spectroscopy, fatty acid analysis, and endoglycoceramidase digestion NeuAc alpha 2----3Gal beta 1----4Glc beta 1----Cer sg-1 [(NeuAc)GM3] KDN alpha 2----3Gal beta 1----4Glc beta 1----Cer sg-2 [(KDN)GM3] where, for both sg-1 and sg-2, the ceramide moieties (Cer) were found to be made up of 4-sphingenine and mainly C16:0 fatty acid (palmitate; 95%) with a minor amount of C24:1 fatty acyl chain (nervonate, 5%). The structure of sg-2 is novel and represents the first example of a new class of gangliosides, i.e. KDN-gangliosides.

Animals↗
PubMed1991

Extracellular matrix and androgen receptor expression associated with spontaneous transformation of rat prostate fibroblasts.

Spontaneous transformation in continuous culture of the androgen-sensitive rat prostate fibroblast cell line, NbF-1, resulted in an aggressively tumorigenic nonmetastatic phenotype that coincided with few gross chromosome abnormalities. This study identified transformation-associated alterations in extracellular matrix and androgen receptor expression in the NbF-1 cell line. Substantial levels of procollagens I, III, and IV and fibronectin mRNAs were detected in nontumorigenic NbF-1 cells. Laminin B1 and B2 mRNAs were also detectable, but at lower levels. Expression of all six extracellular matrix mRNAs was nonuniformly lower in tumorigenic NbF-1 cells. This decrease in expression was greatest for alpha 2 procollagen IV mRNA, which was reduced 17-fold. Proteoglycans and glycosaminoglycans synthesized by the NbF-1 cultures were also characterized. The NbF-1 cell line expressed chondroitin sulfate proteoglycans predominantly, and expression was reduced 5- to 10-fold in tumorigenic cultures. In contrast to the extensive alterations in the extracellular matrix, measurement of high-affinity androgen binding and androgen receptor mRNA levels showed substantial expression of androgen receptors in both NbF-1 cultures. Cultures of early and late passage NbF-1 cells demonstrated a mitogenic response to dihydrotestosterone. These data indicate (a) that alterations in expression of extracellular matrix components may represent early markers for tumorigenic transformation in prostatic mesenchymal cells and (b) that these changes can occur without disrupting androgen receptor expression and androgen sensitivity.

Animals↗
PubMed1991

[The investigation of anti-hepatitis A virus antibody rate in Guangzhou population].

The positive rate of Anti-HAV in 1663 general Guangzhou population were investigated by ELISA in 1988. The total positive rate of anti-HAV antibody ways 65.1%. There are great differences between the overall positive rate of anti-HAV antibody and those in different districts and counties. Among them, the highest rate was 90.2%, the lowest was 46.7%. The overall positive rate of anti-HAV antibody of rural population (79.3%) was significant higher than that of urban population (53.9%). The rates in scattered children (46.5%) were higher than in the organized children (20.8%). Among the less than 4 years old children, boys (39.0%) were higher than the girls (13.3%). Among 0-10 years old children, it presented a tendency of anti-HAV antibody rate from 15.4% to 44.4%, it increased rapidly to 29.73% in children aged 0-4. Among 10-49 years old group, the rate was going up with age. The value of the peak of positive rate of Anti-HAV antibody situated on 45-49 years of age, and after fifty the rate slowly decreased.

Adolescent↗
PubMed1991

[The contents of gamma-aminobutyric acid and glutamic acid in brain affected by coriaria lactone].

Capillary chromatography was applied to studying the contents of gamma-aminobutyric acid (GABA) and glutamic acid (Glu) in brain affected by coriaria lactone. The results showed that there was a significant increase in the content of Glu whereas no significant change in the content of GABA was noted. The precisions for GABA and Glu were 3.3% and 4.98% and the recoveries of them were 80.5% and 85.2%, respectively. Capillary chromatography is a good method for determining the contents of GABA and Glu in brain, which has the characteristics of rapid and high sensitivity.

Animals↗
PubMed1991

[Preventive effect of bombesin on alloxan-induced diabetes in rat].

The effect of bombesin against injury on rat islet B cells was studied in three kinds of experiments: (1). In vivo experiment, it was found that preinjection of bombesin (50 micrograms/kg, sublingual v.) could effectively prevent an increase of plasma glucose and decrease of plasma insulin in diabetic rat induced by alloxan (200 mg/kg, s.c.) (2). In vitro experiment, isolated pancreas perfusion showed that alloxan-induced (14 mmol/L) perfusion fluid inhibition of insulin secretion could be reversed by pretreatment of bombesin (10(-3) mmol/L). (3). Investigation on isolated and incubated islets demonstrated that alloxan induced decrease of insulin and somatostatin secretion and increase of glucagon secretion could be prevented by bombesin. The above-mentioned results suggest that bombesin may play an important role in the regulation of plasma glucose in diabetic rat and have a potent preventive effect against the development of diabetes.

Alloxan↗
PubMed1991

[External counterpulsation in treating angina pectoris evaluated by Tl-201 myocardial perfusion imaging].

Twenty patients with angina pectoris were treated with external counterpulsation (ECP) for 36 hours, and the effects of the therapy were evaluated by comparing the images of thallium-201 myocardial perfusion before and after ECP. Improvement of myocardial perfusion after ECP, evidenced by decrease in area of defects in scintigram, was demonstrated in 15 (75%) cases. The mechanism of the effect of ECP on ischemic myocardium was discussed.

Adult↗
PubMed1991

[Pre- and postoperative splanchnic hemodynamics measured by indocyanine green clearance in patients with portal hypertension].

In this study, plasma indocyanine green clearance (PIGC) and hepatic blood flow (HBF) were measured in patients with portal hypertension before and after pericardial devascularization or side-to-side mesocaval shunt (MS), and the relationship between PIGC and plasma albumin level was investigated. It was found that there was no change in PIGC after the patients underwent pericardial devascularization (portoazygous disconnection). There were a significant decrease of PIGC (averaging 16.28 +/- 8.3%,) and a decrease of HBF (averaging 17.71%, p less than 0.001) after the patients underwent MS. It was also found that there was a positive relationship between PIGC and plasma albumin level in patients with portal hypertension.

Adult↗