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Biomedical subjects

Y Xie

Publications and source records attributed to Y Xie.

At least 379 records · Page 21Linked to original sources
PubMed1994

[Clinical significance of immunohistochemistry and ultrastructural change of myocardium in viral myocarditis].

Endomyocardial biopsy (EMB) specimens from 56 patients with suspected viral myocarditis (VMT) were studied. With microscopical study of the EMB specimens stained with HE, 14 of the 56 cases were diagnosed as myocarditis (25%) and 24 as non-myocarditis (43%). But immunohistochemistry stain showed that the contents of myosin, actin and myoglobin reduced in 51 patients (91%). Ten of 56 specimens were observed under electron microscope (EM). EM examination revealed focal or diffuse lysis of myofibrils in 10 patients. The results showed that: (1) The myofibrils in VMT showed severe damage. (2) Immunohistochemistry and EM examination can be used as a supplement to the Dallas diagnosis standard in order to improve accuracy of EMB in diagnosing VMT.

Actins↗
PubMed1994

[Effect of bee pollen on maternal nutrition and fetal growth].

Plant pollen collected by the honeybee is called bee pollen, which is a natural nutrient. We studied the effects of the bee pollen of Brassia campestres L. on maternal nutrition and fetal growth. Pregnant Sprague-Dawley rats at O-d were divided randomly into three groups. The control group (C) was fed with a diet. The other two groups (A) and (B) were fed with the diet plus bee pollen 20 g/kg.d-1 and 10 g/kg.d-1, respectively. All the dams in each group took a diet and drank water and libitm. Pollen-fed dams in both groups (A) and (B) had greater body weight and higher levels of haemoglobin, total protein, serum iron and albumin (P < 0.01, P < 0.05). Fetuses of pollen-fed dams had greater body weight (P < 0.01) and lower death rate (P < 0.005). No gross external, visceral and skeletal malformations were observed in the fetuses. These results suggested that bee pollen could improve maternal nutrition without affecting normal fetal development. It is a practical and effective nutrient during pregnancy.

Animal Nutritional Physiological Phenomena↗
PubMed1994

[Study on red blood cell immune adherence function in coriaria lactone-induced epileptic seizure rats].

The immune adherence function of red blood cells in 17 rats was studied. It was found that the rosette rate of red blood cell C3b receptor (RBC-C3bRR) was 7.45 +/- 1.36% in the epilepsy group (8 rats), and 10.84 +/- 1.77% in the control group (9 rats); and that the rosette rate of red blood cell immune complex (RBC-ICR) was 7.42 +/- 2.62% in the epilepsy, and 10.80 +/- 1.72% in the control. As compared with the control group, the rosette rate of red blood cell C3b receptor was remarkably decreased in the epilepsy group (P < 0.05). There was no significant difference between the two groups in RBC-ICR. The results from this study demonstrated that the CL-induced seizures might result in decrease in red blood cell immune adherence function of the epilepsy rats.

Animals↗
PubMed1994

[Clinical features and prognosis of paroxysmal atrial fibrillation in the elderly].

Eighty one elderly patients with paroxysmal atrial fibrillation were studied with respect to clinical features, effect of antiarrhythmic drugs and prognosis. 35 (43.2%) patients were associated with coronary artery disease and/or hypertension, while 23 (28.4%) patients had no other cardiovascular diseases. The latter condition was significantly less in patients over 60 years old when they had the first paroxysmal attack. Atrial fibrillation became permanent in 18 (22.2%) patients. Left atrial enlargement and abnormal cardiac function were significant independent factors affecting the type of atrial fibrillation. During an observation period of 12-84 months, the incidence of cerebral embolism and cardiac death were 6.1% and 4.9% respectively in all cases. We did not find that the prognosis of patients was affected by the types of atrial fibrillation.

Aged↗
PubMed1994

[Correlationship between cellular DNA and AgNOR protein content in the developing course of colorectal adenocarcinoma].

Cellular DNA and AgNOR protein content were evaluated by automatic image analysis in tissue sections stained by combined Feulgen-AgNOR method of 9 normal colonic mucosae, 45 colorectal adenomas and 27 colorectal correlation between AgNOR protein and DNA contents. In adenocarcinomas, the DNA and AgNOR protein contents were higher than those in adenomas, which were in turn higher than those in normal colonic mucosa. However, there was considerable overlapping in the DNA or AgNOR protein content between adenoma and adenocarcinoma groups and between adenoma and normal colonic mucosa groups. By assessing the correlationship between the DNA and AgNOR protein contents, the number of the overlapping cases was reduced significantly. Therefore it is much more reliable to distinguish colorectal adenomas from adenocarcinomas by using the correlationship between the cellular DNA and the AgNOR protein contents in the same specimens.

Adenocarcinoma↗
PubMed1994

[Kaschin-Beck's disease in children's wrists: radiographic findings].

Based on the analysis of hand radiographs in 208 children with Kaschin-Beck's disease, the author's chief conclusions are as follow: The more severe Kaschin-Beck's is, the more opportunity the carpals have to be involved. Generally speaking, the capitatum and hamatum are frequently involved if the disease involves the carpals.

Adolescent↗
PubMed1994

Esophageal Crohn's disease--a case report.

A case of esophageal Crohn's disease in a 52-year-old man is described. The patient was treated successfully by surgical excision of the esophagus. Because esophageal Crohn's disease is uncommon, we would like to discuss its clinical characteristics and to review the literature.

Crohn Disease↗
PubMed1993

Identification and characterization of a factor which is essential for assembly of transcarboxylase.

Transcarboxylase (TC) from Propionibacterium shermanii is a biotin-containing enzyme which catalyzes the reversible transfer of a carboxyl group from methylmalonyl-CoA to pyruvate. It is composed of a central, hexameric 12S subunit with six outer, dimeric 5S subunits held in a stable 26S complex by twelve 1.3S biotinyl subunits. Each of these subunits has been cloned from the P. shermanii genome and expressed in Escherichia coli. The purified, expressed recombinant proteins are all indistinguishable from their authentic counterparts except for the recombinant 5S subunit (termed 5S WT), which does not form TC complexes or catalyze the overall transcarboxylase reaction. Circular dichroism and isoelectric focusing suggested differences existed between the authentic and E. coli-expressed 5S proteins. HPLC gel filtration was used to separate the authentic 5S dimer from additional components in the preparation. 5S dimer thus purified was unable to form TC complexes or catalyze the overall reaction, behaving identically to the recombinant 5S WT subunit. Fractions from the HPLC gel-filtration purification of authentic 5S were then added to 5S WT or 5S dimer, and one fraction was identified which catalyzed the assembly of TC complexes with either 5S preparation. This assembly activity was shown to be dependent on the concentration of this HPLC fraction. Assembly-promoting factor (APF) is heat-stable and probably a protein, on the basis of its protease susceptibility. Studies with APF and the other TC subunits demonstrate its ability to promote complex formation with 12S and 1.3S subunits. Since the APF was purified from crystals of 26S TC, we believe it to be a novel, previously unidentified subunit of transcarboxylase.

Biotin↗
PubMed1993

Molecular cloning and adhesive properties of murine platelet/endothelial cell adhesion molecule 1.

We describe the isolation and characterization of a functional murine platelet/endothelial cell adhesion molecule (PECAM) 1 cDNA clone from a mouse lung library. At the nucleotide level, the coding sequence of murine PECAM-1 is 73% identical to human PECAM-1, and at the amino acid level, the sequence is 79% homologous to its human counterpart. Southern hybridization reveals that one copy of the gene exists in the mouse genome; Northern hybridization reveals a single mRNA species in mouse lung tissue. COS-7 and mouse L cells transfected with murine PECAM-1 expressed a 130-kDa glycoprotein on their surfaces that reacted with anti-murine PECAM-1 monoclonal antibody and comigrated on SDS/PAGE with human PECAM-1. Stable L-cell transfectants aggregate with each other in a PECAM-dependent, homophilic manner.

Amino Acid Sequence↗
PubMed1993

Isoglobotetraosylceramide is a marker for highly metastatic cells in rat mammary adenocarcinomas.

We have previously identified a neutral glycolipid antigen which appears to be a surface antigenic marker for the metastatic subpopulation in the R3230AC rat mammary adenocarcinoma (S.A. Carlsen, M. Barry, and K. Newton, Clin. Exp. Metastasis, 8: 141-151, 1990). In this article we describe the structural characterization of this glycolipid antigen. The sequence of the sugars in the saccharide portion of the molecule was determined by specific glycosidase cleavage and further confirmed by mass spectroscopic analysis. The nature of the linkages between the monosaccharide units was determined by methylation analysis. The final structure was confirmed by NMR analysis and found to be isoglobotetraosylceramide (GalNAc beta 1-3Gal alpha 1-3Gal beta 1-4Gle beta 1-O-ceramide). We also present evidence that the cells marked by this antigen have a higher metastatic potential than the cells lacking this glycolipid as measured by the formation of lung colonies after i.v. injection of the cells into the tail vein of the rat. Furthermore, isoglobotetraosylceramide seems to play a direct role in the metastatic process since the blocking of exposed antigen with monoclonal antibodies, or their Fab fragments, results in a highly significant decrease in lung colony formation.

Adenocarcinoma↗
PubMed1993

Purification and characterization of the recombinant 5 S subunit of transcarboxylase from Escherichia coli.

Transcarboxylase from Propionibacterium shermanii is a biotin-containing enzyme which catalyzes the reversible transfer of a carboxyl group from methylmalonyl-CoA to pyruvate. It is composed of a central, hexameric 12 S subunit, 6 outer dimeric 5 S subunits which are held in a complex by 12 1.3 S biotinyl subunits. The transcarboxylase reaction requires two partial reactions, one of which is specific to 5 S. The cloning and expression of each of these subunits in Escherichia coli have been reported. We have designed a method for the purification of the 5 S subunit from an E. coli expression system. Protein purified to homogeneity by this method was shown to be active in the 5 S partial reaction, but unable to catalyze the overall transcarboxylase reaction. This protein was characterized as to its ability to form stable dimers, associate with the 1.3 S subunit in stable complexes referred to as 6 S, and assemble whole TC. The latter activity was shown to be lacking. The purified protein has a native molecular weight of 120 kDa and a subunit molecular weight of 60 kDa, consistent with the 5 S dimer. Plasma emission analysis of the metal content of the recombinant protein demonstrated the presence of both Co and Zn, comparable to the authentic protein. Fluorescence analysis verified the ability of the purified protein to bind substrates and 1.3 S subunits appropriately. Sequencing of the amino terminus and determination of the amino acid composition of the recombinant protein relative to that of the authentic subunit further verified the identity of the purified protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1993

The indirect pathway of hepatic glycogen synthesis and reduction of food intake by metabolic inhibitors.

The increasingly recognized role of the indirect pathway (glycolysis followed by hepatic gluconeogenesis) for glucose utilization and glycogen synthesis by the liver led us to administer 3-mercaptopicolinate (3MP), an inhibitor of phosphoenolpyruvate-carboxykinase, in an attempt to assess the role of liver glycogen or hexose-phosphates in the food-intake reducing effects of (-)hydroxy-citrate. Administration of (-)hydroxy-citrate increased hepatic glycogen content in i.v. glucose refed rats. Using the glucuronide probe technique, the mechanism of increased glycogen deposition was shown to be prolongation of indirect pathway (recycled) input. Daily (-)hydroxy-citrate significantly reduced food intake (from 12.0 +/- 2.3 to 6.4 +/- 3.6 g/day, p < 0.05) and had no chronic effect on hepatic glycogen content in rats trained to a single daily meal (meal-fed). Administration of 3MP completely suppressed hepatic glycogen synthesis (< 0.5 mg/g) when given alone or with (-)hydroxy-citrate. Isotopic studies confirmed inhibition of the indirect pathway of UDP-glucose synthesis. 3MP accentuated rather than prevented the (-)hydroxy-citrate reduction in food intake in meal-fed rats (intake 2.7 +/- 2.4 g/day). When given alone, 3MP also reduced intake (6.1 +/- 3.6 g/day). Severe hypoglycemia was observed (glucose < 20 mg/dl) in several meal-fed rats given repeated daily doses of 3MP, yet food intake did not occur despite food availability. Neither 3MP nor (-)hydroxy-citrate had any effects when given after the daily meal. We conclude that the role of the indirect glycogen synthesis pathway must be considered in any theory of regulation of food intake by hepatic metabolites and that, if the effects of these metabolic inhibitors can be shown not to be toxic or non-specific, neither hepatic glycogen nor hexose-phosphates are involved in the food-intake suppressive effects of (-)hydroxycitrate.

3-Hydroxybutyric Acid↗
PubMed1993

Differential transcription and translation of immediate early genes in the gerbil hippocampus after transient global ischemia.

Excitotoxic activation of glutamate receptors is thought to be a key event for the molecular pathogenesis of postischemic delayed neuronal death of CA-1 neurons in the gerbil hippocampus. Glutamate receptor stimulation also causes induction of transcription factors that belong to the class of immediate early genes. We examined the expression of six different immediate early genes in the gerbil hippocampus after transient global ischemia. Comparative analysis of c-fos and Krox-24 expression was carried out in the same animals at the transcriptional and translational level by in situ hybridization and immunocytochemistry. Postischemic synthesis of four additional immediate early gene (IEG)-encoded proteins (FOS-B, c-JUN, JUN-B, and JUN-D) was investigated by immunocytochemistry at recirculation intervals between 1 and 48 h. After 5 min of ischemia, transcription of c-fos and Krox-24 mRNA was induced in all hippocampal subpopulations with peak expression at 1 h after recirculation. In vulnerable CA-1 neurons, increased transcription of c-fos and Krox-24 was not followed by translation into protein. Induction of immediate early gene-encoded proteins was restricted to neuronal populations less vulnerable to brief ischemia and identified neurons that are targets of glutamate receptor-mediated neurotoxicity but that are destined to survive. Our data indicate an asynchronous synthesis and persistence of individual IEG-encoded proteins in these neurons. The staggered induction implies that combinatorial changes of transcription factors allow a differential postischemic regulation of target gene expression both spatially and over time.

Animals↗
PubMed1993

Light-regulated and cell-specific expression of tomato rbcS-gusA and rice rbcS-gusA fusion genes in transgenic rice.

A previously isolated rice (Oryza sativa) rbcS gene was further characterized. This analysis revealed specific sequences in the 5' regulatory region of the rice rbcS gene that are conserved in rbcS genes of other monocotyledonous species. In transgenic rice plants, we examined the expression of the beta-glucuronidase (gusA) reporter gene directed by the 2.8-kb promoter region of the rice rbcS gene. To examine differences in the regulation of monocotyledonous and dicotyledonous rbcS promoters, the activity of a tomato rbcS promoter was also investigated in transgenic rice plants. Our results indicated that both rice and tomato rbcS promoters confer mesophyll-specific expression of the gusA reporter gene in transgenic rice plants and that this expression is induced by light. However, the expression level of the rice rbcS-gusA gene was higher than that of the tomato rbcS-gusA gene, suggesting the presence of quantitative differences in the activity of these particular monocotyledonous and dicotyledonous rbcS promoters in transgenic rice. Histochemical analysis of rbcS-gusA gene expression showed that the observed light induction was only found in mesophyll cells. Furthermore, it was demonstrated that the light regulation of rice rbcS-gusA gene expression was primarily at the level of mRNA accumulation. We show that the rice rbcS gene promoter should be useful for expression of agronomically important genes for genetic engineering of monocotyledonous species.

Amino Acid Sequence↗