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Biomedical subjects

Ming Sun

Publications and source records attributed to Ming Sun.

68 records · Page 4Linked to original sources
PubMed2003

[Protective effects of phosphoramidon on the experimental myocardial injury in rats].

OBJECTIVE: To investigate the protective effects of phosphoramidon on the experimental myocardial injury in rats. METHODS: Thirty-six Wistar rats were randomly divided into 3 groups of 12: the control group (Control), the isoproterenol group (ISO) and the protection group (PA). All rats were anesthetized after 24 hours and the blood was sampled from the carotid artery. The activities of creatine phosphokinase (CPK) and lactic dehydrogenase (LDH) in the serum and the contents of ET in the plasma were detected; then the hearts were isolated and the total layers of apical myocardium were solidified, embedded, sectioned, stained with HE and graded pathologically. RESULTS: The serum activities of CPK and LDH, and the plasmatic content of ET in the ISO group were significantly higher than those in the control group and PA group (P < 0.05); the degree of myocardial pathological damage in the ISO group was significantly higher than that in the control group (P < 0.01), while the degree of damage in the PA group was lower than that in the ISO group (P < 0.05). CONCLUSION: Endothelin is involved in the pathologic process of experimental myocardial injury in rats. Phosphoramidon can protect the myocardial injury in rats and its mechanism may be to inhibit ECE and reduce the endothelins production.

Animals↗
PubMed2003

[Expression of gene aiiA carrying the promoter of gene cry3Aa in Bacillus thuringiensis].

N-acyl-homoserine lactones (AHLs), are widely conserved signal molecules present in quorum-sensing systems of many Gram-negative bacteria. AHLs molecules mediate the expression of virulence genes of a range of bacterial pathogens. Recently, it has been reported that AiiA protein, which widely exists in Bacillus species, can inactivate the AHLs by hydrolyzing the lactone bond of AHLs, thus attenuate the diseases caused by the expression of virulence genes of bacterial pathogens. Bacillus thuringiensis, a type of Gram-positive bacteria, has been used extensively as a microbial insecticide in the last few decades. However, most of important insecticidal B. thuringiensis strains have not been exploited for bacterial disease control because they usually do not produce antibiotics that are effective against bacteria and fungi. The discovery of AiiA protein in B. thuringiensis shows the application potential of B. thuringiensis on biocontrol against bacterial diseases. In this study, in order to construct the B. thuringiensis recombinant strain that has high expression of AiiA protein, the promoter of insecticidal crystal protein coding gene cry3Aa of B. thuringiensis was selected. The promoter of gene cry3Aa is a non-sporulation promoter, it promotes the transcription earlier and longer than the promoters of other cry genes. The promoter of AiiA protein coding gene aiiA was replaced with the promoter of gene cry3Aa by overlapping PCR, resulting fusion gene pro3A-aiiA. The gene pro3A-aiiA was inserted into shuttle vector pHT304 at site BamH I / Sph I , resulting recombinant plasmid pBMB686. The plasmid pBMB686 was introduced into B. thuringiensis acrystalliferous strain BMB171, the resulting strain BMB686 had a higher and more stable expression level of protein AiiA comparing with the parental strain BMB171. Furthermore, the strain BMB686 exhibited stronger ability of AHLs inactivation and much more effective restraint to the potato's soft rot disease caused by Erwinia carotovora than those of the parental strain BMB171. From these results, it was concluded that the B. thuringiensis strain harvesting the fusion gene pro3A-aiiA may be utilized in the future to control bacterial diseases which are mediated by the AHL quorum-sensing signals.

Acyl-Butyrolactones↗
PubMed2002

[Relationship of hypertensive microalbuminuria and endothelial and glomerular impairment].

OBJECTIVE: To investigate the relationship between hypertensive microalbuminuria and vascular endothelial and glomerular impairment. METHODS: The animals were divided into the normotensive group (WKY Rat), hypertensive treated group (SHR with losartan) and untreated group(SHR). The blood pressure, level of microalbuminuria, and renal function were measured. In addition, endothelium of the mesenteric artery and glomerular mesangial cells were observed with the transmission electronic microscope in three and eight-month-old rats respectively. RESULTS: Significantly increased microalbuminuria was shown in SHR, which was correlated with the blood pressure and vascular endothelial volume density. Early impairment of vascular endothelium and the glomerular basement membrane was demonstrated in three-month-old SHR. However, there was no significant difference in glomerular mesangial cells and renal function between SHR and WKY rats. In the eight-month-old untreated group, the volume density of glomerular mesangial cells increased significantly, which indicated a further impairment of hypertension. The level of microalbuminuria was not correlated with the blood pressure. Compared with the untreated group, the hypertensive treated group showed a decreased volume density of vascular endothelium and glomerular mesangial cells, which was accompanied with a reduction of microalbuminuria. CONCLUSION: The mechanism which causes microalbuminuria in hypertension may vary with the severity of the hypertensive condition. At the early stage, the haemodynamics mechanism seems to be the most plausible cause of microalbuminuria, whereas at the severe stage, glomerular damage and vascular remodeling are likely to play the key role. Losartan can inhibit those deteriorations besides blood pressure lowering.

Albuminuria↗
PubMed2002

[Clinical characteristics of fatty livers of 61 patients with the insulin resistance syndrome].

OBJECTIVE: To analyse the clinical characteristics of fatty livers of patients with the insulin resistance syndrome. METHODS: With echographic histogram, the acoustic intensity (AV) in six different areas of each fatty liver was measured in 61 patients with the insulin resistance syndrome. The relationship between the average value of AV and some clinical or biochemical parameters were analysed. RESULTS: There were significant differences in AV between the area near the portal venous and the area near the gall bladder, and between males and females as well. AV was positively related to the body mass ratio (BMI), waist circle (W) and hip circle (H); AV was positively related to the waist-hip ratio (WHR) or insulin sensitive index (ISI) in trend; and AV was negatively related to high density lipoprotein cholesterin (HDL-C). CONCLUSION: In patients with the insulin resistance syndrome, fatty density of livers is higher near the portal venous than near the gall bladder. The fatty liver is more serious in females than in males. BMI, W, H and serum HDL-C levels are useful parameters in evaluating the severity of fatty livers.

Adult↗
PubMed2002

A comparative study of odorant binding protein genes: differential expression of the PBP1-GOBP2 gene cluster in Manduca sexta (Lepidoptera) and the organization of OBP genes in Drosophila melanogaster (Diptera).

Insects discriminate odors using sensory organs called olfactory sensilla, which display a wide range of phenotypes. Sensilla express ensembles of proteins, including odorant binding proteins (OBPs), olfactory receptors (ORs) and odor degrading enzymes (ODEs); odors are thought to be transported to ORs by OBPs and subsequently degraded by ODEs. These proteins belong to multigene families. The unique combinatorial expression of specific members of each of these gene families determines, in part, the phenotype of a sensillum and what odors it can detect. Furthermore, OBPs, ORs and ODEs are expressed in different cell types, suggesting the need for cell-cell communication to coordinate their expression. This report examines the OBP gene family. In Manduca sexta, the genes encoding PBP1Msex and GOBP2Msex are sequenced, shown to be adjacent to one another, and characterized together with OBP gene structures of other lepidoptera and Drosophila melanogaster. Expression of PBP1Msex, GOBP1Msex and GOBP2Msex is characterized in adult male and female antenna and in larval antenna and maxilla. The genomic organization of 25 D. melanogaster OBPs are characterized with respect to gene locus, gene cluster, amino acid sequence similarity, exon conservation and proximity to OR loci, and their sequences are compared with 14 M. sexta OBPs. Sensilla serve as portals of important behavioral information, and genes supporting sensilla function are presumably under significant evolutionary selective pressures. This study provides a basis for studying the evolution of the OBP gene family, the regulatory mechanisms governing the coordinated expression of OBPs, ORs and ODEs, and the processes that determine specific sensillum phenotypes.

Amino Acid Sequence↗
PubMed2002

[A novel resolution vector with Bacillus thuringiensis plasmid replicon ori44].

The resolution recognization sites of transposon Tn4430 of Bacillus thuringiensis was inserted into cloning vector pRSET B and pUC19, resulting recombinant plasmids pBMB1201 and pBMB1202. Both of the mini res fragments, BamHI/HindIII fragment in pBMB1201 and EcoRI/HindIII fragment in pBMB1202, were ligated to the 3.3 kb EcoRI/HindIII fragment of shuttle vector pHT3101, which contained the ori. Ec, ampr and emr antibiotic resistant genes, resulting recombinant plasmid pBMB1203. After deleted the BamHI and EcoRI sites which located ouside the two res sites, resolution vector pBMB1204 was resulted. There are multiple cloning sites between two copies of resolution sites which have the same direction. The plasmid replication origin ori44, which come from B. thuringiensis sub sp. kurstaki strain YBT-1520, was inserted into the multiple cloning sites of pBMB1204 and then resolution shuttle vector pBMB1205 was obtained. With spectinomycin resistant gene as target, it was found that the resolution rate is 100% and the stability of the resolved plasmid is 93%. Using this shuttle vector, antibiotic resistance markers and other non-B. thuringiensis DNA can be selectively eliminated after the selection of transformants by antibiotic resistance marker. This vector is very useful to solve the gene safety problem while has no effect on target gene expression.

Bacillus thuringiensis↗
PubMed2002

Apoptosis, myocardial fibrosis and angiotensin II in the left ventricle of hypertensive rats treated with fosinopril or losartan.

OBJECTIVE: To investigate the different effects of an angiotensin II type 1 (AT(1)) receptor antagonist, losartan, and an angiotensin converting enzyme (ACE) inhibitor, fosinopril, on cardiomyocyte apoptosis, myocardial fibrosis, and angiotensin II (Ang II) in the left ventricle of spontaneously hypertensive rats (SHRs). METHODS: SHRs of 16-week-old were randomly divided into 3 groups: SHR-L (treated with losartan, 30 mg.kg(-1) x d(-1)), SHR-F (treated with fosinopril, 10 mg x kg(-1) x d(-1)), and SHR-C (treated with placebo). Each group consisted of 10 rats. Five rats, randomly selected from each group, were killed at the 8th and 16th week after treatment. Cardiomyocyte apoptosis, collagen volume fraction (CVF), perivascular collagen area (PVCA) and Ang II concentrations of plasma and myocardium were examined. RESULTS: Compared with the controls at the 8th and 16th week, systolic blood pressures were similarly decreased in both treatment groups. Left ventricular weight and left ventricular mass indexes were significantly lower in both treatment groups. However, the latter parameter at the 16th week was reduced to a less extent in the fosinopril group than that in the losartan group. Compared with the controls, cardiomycyte apoptotic index was significantly reduced at the 8th week only in the fosinopril group, and at the 16th week in both treatment groups. The index of the fosinopril group was lower than that of the losartan group at the latter endpoint examined. Compared with the controls, the left ventricular collagen volume fraction and perivascular collagen area at the 8th and 16th weeks were significantly reduced in the SHRs treated with either fosinopril or losartan. However, the collagen volume fraction at the latter endpoint in the fosinopril group was lower than that in the losartan group. Compared with the controls at endpoints, plasma and myocardium Ang II levels were significantly increased in the losartan group. However, plasma Ang II concentrations were not altered, and myocardium Ang II concentrations at the 8th and 16th weeks were significantly reduced in the fosinopril group. CONCLUSIONS: Both losartan and fosinopril could effectively inhibit cardiomyocyte apoptosis and myocardial fibrosis and reverse heart hypertrophy. Fosinopril may be more effective in these cardioprotective effects, suggesting that the effects of both drugs are related to the inhibition of myocardium renin-angiotension-aldsterone system.

Angiotensin II↗
PubMed2002

[The cloning of plasmid replicon ori165 from Bacillus thuringiensis subsp. thenebrionis].

An EcoRI DNA fragment containing the plasmid replicon, named ori165, was cloned from the plasmids of B. thuringiensis subsp. tenebrionis strains YBT-1765. The replicon ori165 was the first replicon cloned from this subspecie. Its size is approximately 11 kb. The replicon was minimized to an 8 kb fragment by deletion analysis. Southern hybridization exhibited that ori165 was coming from the plasmid detected with the highest molecular weight. A shuttle vector pBMB6071 based on ori165 was constructed. The stabilities of pBMB6071 in different B. thuringiensis host had great discrepancy. In strain 4Q7, a crystal-negative derivative of B. thuringiensis subsp. isrealensis, the stability was 100%. ori165 was compatible with ori1030 and ori2062 in strain BMB171, a crystal-negative derivative of B. thuringiensis subsp. kurstaki.

Bacillus thuringiensis↗
PubMed2002

[The analysis of Bacillus thuringiensis vegetative insecticical protein gene cloning and expression].

Three kinds of Bacillus thuringiensis serotype-subsp. Leesis(H33) strain YBT-833, subsp. Aizawai(H7) strain YBT-1416 and subsp. Kurstaki(H3ab) strain YBT-1535, which were isolated by our lab, are chosen as original strain to clone vegetative insecticidal protein gene. Southern hybridization showed that vip genes are all localized at roughly 4-5 kb size-fractionated XbaI fragments of total DNA from YBT-833, YBT-1416 and YBT-1535. Three subgenomic libraries containing the vip gene fragment, were constructed with pUC19 as vector. Then, three vegetative insecticidal protein gene vip83, vip14 and vip15 are obtained from the libraries through the methods of colony-blot-in-situ screening and enzyme-cut detection. Comparision of DNA sequence made out that only vip83 gene exist five different base pairs with known vip genes. Because the sequences of vip14 and vip15 are the same, two of the three genes, vip83 and vip14, were subcloned to shuttle vehicle pHT315 to get recombinant plasmids pBMB8901 and pBMB8902 in turn. The plasmids were separately transformed into vip Bt. receptors BMB171 and 4Q7 to obtain four engineered strains BMB8901-171, BMB8902-171, BMB8901-4Q7 and BMB8902-4Q7. SDS-PAGE results indicated that all recombinant strains express 88 kD vegetative insecticidal protein. Bioassay also showed that the proteins of genes vip83 and vip14 both have certain toxicity to Lepidopteran insect larvae such as Heliochis armigera, Spodotera exigua and Plutella xylostella. While the toxicity of vip protein from four engineered strains to Plutella xylostellas are highest, whose LC50 value is 28.6, 31.6, 45.4 and 37.6 microL/mL respectively. This study will contributed to construct high efficacy and wide spectrum engineered strains on theory and reality.

Animals↗
PubMed2002

The tracheal detecting-bulb: a new device to distinguish tracheal from esophageal intubation.

BACKGROUND: The tracheal detecting-bulb (TDB) is a diagnostic tool for confirmation of tracheal intubation. Capnography is also accepted as a standard way for such confirmation. The purpose of this investigation was to determine whether the results by TDB agreed with those by capnography. METHODS: Four hundred patients were allocated to three separate studies. In 200 consecutive patients of study 1, tracheal intubation was first confirmed with the TDB followed by capnography. In study 2, 100 patients had the esophagus intentionally intubated, and confirmation was performed likewise as in study 1. The tube was then removed, the trachea was intubated, and confirmation tests followed. Study 3 involved 100 patients and was carried out in a double-blind, randomized manner. The tube was intentionally inserted into either the esophagus (n = 42) or trachea (n = 58), and confirmation tests immediately followed. RESULTS: In study 1, the rhythmic expansion-contraction of TDB was evident in 173 patients, and always agreed with capnographic reading; In 27 instances, the latex bulb of TDB remained collapsed or was scantily filled without the turning-up of capnographic reading as counterchecked, indicating esophageal intubation. In study 2, regardless of esophageal or tracheal intubation, agreement between TDB and capnogram was 100%. In study 3, the agreement between the two detecting instruments was 100% too. In the 400 patients studied, the results from the TDB were in complete accord with those of capnogram. The sensitivity, specificity, and predictive value of the TDB in all of these studies were 100%. CONCLUSIONS: The TDB is a valuable diagnostic technique for confirming tracheal intubation as it could correctly detect esophageal or tracheal intubation of the tracheal tube in all our 400 patients. The results of using TDB agree with the results of using capnography.

Adolescent↗
PubMed2000

Early Expression of Protooncogenes Induced by the Binding to Cells of Two Viruses.

The specific binding of virus to receptor is essentially the interaction of ligand and receptor. This binding is able to induce cellular primary gene response that has various regulatory function in cells. Different immediate-early gene responses could be induced with different binding virus. The different gene responses were observed as poliovirus and HSV-I bind to human diploid cells. These differences showed that early expression of protooncogenes were enhanced and/or suppressed in the primary gene responses.

Journal Article↗
PubMedDate not supplied

Increased resting energy expenditure in patients with end-stage renal disease.

BACKGROUND: Protein-calorie malnutrition is a significant problem for patients with end-stage renal disease. Increased resting energy expenditure may be an important contributing factor. We postulate that resting energy expen diture in the different stages of renal disease and treatments may be different. METHODS: Resting energy expenditure was measured using a whole-room indirect calorimeter (metabolic chamber) along with nutritional parameters and body composition after 12-hour fasting in 15 patients with advanced chronic renal failure patients, 15 patients on chronic hemodialysis, and 10 patients on peritoneal dialysis. Patients on hemodialysis were assessed on a non-dialysis day. A 2-day dietary recall was used to assess energy intake. RESULTS: Resting energy expenditure, adjusted for fat-free mass, was similar in patients on hemodialysis and peritoneal dialysis but significantly higher than in patients with chronic renal failure (p < .05). Resting energy expenditure in all patients were generally higher (10% to 20%) than predicted values using standard equations derived in normal and obese populations, whereas daily energy intake was less (26% to 34%) than energy expenditure for all groups, adjusted for light daily activity. CONCLUSIONS: End-stage renal disease patients displayed increases in resting energy expenditure over the predicted values derived using normal populations. Resting energy expenditure was significantly higher in patients receiving dialysis, regardless of the modality, than patients with chronic renal failure. Daily energy intake was substantially less than required in all patient groups studied, suggesting that patients with renal failure could develop protein-calorie malnutrition because of increased resting energy expenditure, which is exacerbated by dialysis.

Blood Proteins↗