Biomedical subjects

Q Zhang

Publications and source records attributed to Q Zhang.

At least 217 records · Page 12Linked to original sources

PubMed2001

Inhibitory learning tests of conditioned stimulus associability in rats with lesions of the amygdala central nucleus.

Normal rats showed faster inhibitory learning about a light conditioned stimulus (CS) if it had previously been an inconsistent predictor of a tone CS than if it had been a consistent predictor of the tone. In contrast, the inhibitory learning of rats with ibotenic acid lesions of the amygdala central nucleus (CN) was unaffected by the prior predictive value of the light. These results support claims that the CN is critical to surprise-induced enhancement of attentional processing of CSs.

Acoustic Stimulation↗

PubMed2001

The structure of networks in living systems.

It is known today there are many networks existing in living systems like signal transduction, transcriptional regulation, immanence response and like so on. These networks, like all the other networks, are based on relationships between elements. In this contribution, we propose a network model of living systems. It possesses information of connections among nodes, which stand for critical elements in a network. We formulate it as a simple model of probability theory and find interesting phenomena in it.

Computational Biology↗

PubMed2001

Atrioventricular block complicating inferior acute myocardial infarction treated with thrombolytic therapy.

OBJECTIVE: To investigate the influence and mechanism of incidence of atrioventricular block (AVB) treated with thrombolytic therapy in acute inferior myocardial infarction (AIMI). METHODS: A total of 46 patients with AIMI were divided into the thrombolytic group (n = 23) and the non-thrombolytic group (n = 23). Intravenous or intracoronary urokinase was given to the former group. We observed the advancing courses of AVB, and further assessed the relationship between occurrence of AVB and stenosis of infarct-related artery (IRA) with coronary angiography. RESULTS: Two cases died of III degree AVB in the non-thrombolytic group, but none was found in the thrombolytic group. The occurrence rate of AVB was similar in both groups; but that of III degree AVB was much lower in the thrombolytic group (4 cases) than that in the non-thrombolytic group (11 cases, P < 0.05), and the duration of AVB decreased from 201 +/- 113 hours to 102 +/- 60 hours after thrombolytic therapy (P < 0.01), which was mainly due to the decrease of AVB in the vanishing interval, but not in the developing interval. The coronary angiography demonstrated that there were an increasing reperfusion flow and a decreasing coronary stenosis of the infarct-related artery after thrombolytic therapy. CONCLUSION: Thrombolytic therapy can reduce the incidence of severe AVB, shorten its duration and decrease the mortality by increasing the coronary reperfusion flow in the patients with AIMI.

Adult↗

PubMed2001

Eudesmanolides, aromatic derivatives, and other constituents from Carpesium cernuum.

A new eudesmanolide 13-hydroxy-4 alpha H-eudesman-5,7(11)-dien-12,8 beta-olide (1) and a new aromatic derivative 3-methyl-8-acetoxy-9,10-diisobutanoyloxy-p-cymene (6), along with ten known compounds were isolated from the roots of Carpesium cernuum L. Their structures were elucidated by spectral methods (IR, EIMS, FAB-MS, 1D and 2D NMR). Compound 2, 3 and compound 10 exhibited moderate antibacterial activity against Bacillus subtilis, Escherichia coli and Staphylococcus aureus.

Anti-Bacterial Agents↗

PubMed2001

Patient satisfaction with rizatriptan versus other triptans: direct head-to-head comparisons.

This study summarises the impact of treatment with rizatriptan 10 mg versus other 5-HT 1B/1D receptor agonists (triptans) on patient satisfaction with medication. Rizatriptan is a potent, selective 5-HT1B/1D receptor agonist shown to be fast, effective and well tolerated in the acute treatment of migraine. We investigated patients' overall satisfaction with treatment in studies in which direct comparisons with other triptans were made. Data from five double-blind, placebo-controlled trials in which rizatriptan 10 mg was compared with another triptan were included in the analysis. Rizatriptan 10 mg was compared with sumatriptan 100 mg in one parallel study (n = 916), sumatriptan 50 mg in two crossover studies (n = 1599), naratriptan 2.5 mg in one parallel study (n = 502), and zolmitriptan 2.5 mg in one parallel study (n = 701). Satisfaction was reported by patients on a seven-point scale ranging from 'completely satisfied, couldn't be better' to 'completely dissatisfied, couldn't be worse' at 2 hours after dosing. The percent of patients in the top two 'satisfied' categories (completely or very satisfied) were analysed. More patients on rizatriptan 10 mg were completely or very satisfied compared with sumatriptan 100 mg (33% vs 26%, p < 0.05), sumatriptan 50 mg (40% vs 35%, p < 0.05), naratriptan 2.5 mg (33% vs 19%, p < 0.01), and zolmitriptan 2.5 mg (38% vs 30%, p < 0.05). In all five studies more patients treated with rizatriptan 10 mg or other triptans were completely or very satisfied with treatment than patients receiving placebo (p < 0.001, except naratriptan vs placebo p = 0.004). The results, combined with the superior efficacy profile (fast, effective, well tolerated) of rizatriptan 10 mg, should enhance the treatment of migraine headache and lead to improved therapeutic intervention in clinical practice.

Adolescent↗

PubMed2001

[Study on the epidemic characteristics and burden of injuries among inhabitants in Shenzhen].

OBJECTIVE: To understand of characteristics and burden of injuries in people living in Shenzhen. METHODS: A cluster sample on the condition was conducted through house hold questionnaire administration among 11,576 inhabitant during the period of December 1999 to 2000 in Shenzhen city, Guangdong province. RESULTS: The overall incidence of injuries was 7.07%. Accident, fallings, collision wounds were the first three injures. The standard mortality of injuries was 54.13/10(5). The burden of person family and society were hospital fee-for-service induce unemployment, and so on. Mind burden gave priority to be down in spirits, it occupied to 31.62%. CONCLUSIONS: The incidence of injury were higher in Shenzhen inhabitant, and its burden be weighter, and the incidence of inhabitant with temporary cards was higher than inhabitants with resident cards. Therefore it is very important that prevention and control of injury would be enhancing.

Adult↗

PubMed2001

Atrophy of relay neurons in magno- and parvocellular layers in the lateral geniculate nucleus in experimental glaucoma.

PURPOSE: To determine whether in glaucoma there is atrophy of relay neurons in magnocellular and/or parvocellular lateral geniculate nucleus (LGN) layers projecting to the visual cortex and to compare the degree of neuronal atrophy in magnocellular layers with that in parvocellular layers. METHODS: Seven cynomolgus monkeys with unilateral experimentally induced glaucoma and five control monkeys were studied. The left LGN neurons in magnocellular layer 1 and parvocellular layers 4 and 6, connected to the right glaucomatous eye were examined. Immunocytochemistry with antibody to parvalbumin was used to specifically label relay neurons connecting to the visual cortex. Neuronal cell body cross-sectional area was estimated using unbiased point-counting methodology. Experimental and control groups were compared using t-tests. Analysis of covariance (ANCOVA) tests were used to compare the percentage of decrease in mean neuronal area between layers 1, 4, and 6, as a function of percentage of optic nerve fiber loss or mean IOP. There was significant correlation between percentage of optic nerve fiber loss and mean IOP. RESULTS: The mean cross-sectional area of relay neurons in magnocellular layer 1 and parvocellular layers 4 and 6 were significantly decreased in glaucoma compared with controls by 28%, 37%, and 45%, respectively. Neuronal area decreased in a linear fashion, with increasing optic nerve fiber loss or increasing mean IOP for layers 1, 4, and 6. The percentage of neuronal shrinkage in each of parvocellular layers 4 and 6, as a function of optic nerve fiber loss (P = 0.05; P = 0.001, respectively) or mean IOP (P = 0.046; P = 0.0008, respectively), was greater than that seen in magnocellular layer 1. CONCLUSIONS: Relay neurons in the LGN, which project to the visual cortex, undergo significant shrinkage in glaucoma, and neurons in parvocellular layers undergo significantly more shrinkage than neurons in magnocellular layers.

Animals↗

PubMed2001

Uptake of cyclosporine A loaded colloidal drug carriers by mouse peritoneal macrophages in vitro.

AIM: To investigate the uptake of cyclosporine A loaded colloidal drug carriers by mouse peritoneal macrophage (MPM) in vitro. METHODS: The [3H]cyclosporine A loaded colloidal particles: polylactic acid nanospheres, polylactic acid nanocapsules, and microemulsions were prepared. The [3H]cyclosporine A loaded colloidal particles were incubated with MPM for 30 min at 37 degrees C, then the cells were separated from the colloidal particles and the radioactivity was measured by a liquid scintillation counter. RESULTS: In comparison to the cyclosporine A solution, the binding to polylactic acid nanospheres produced a 20-fold increase in the uptake of cyclosporine A by MPM in 30 min incubation, whereas some obvious decrease in the uptake of cyclosporine A by MPM was observed in the binding of cyclosporine A with polylactic acid nanocapsules or microemulsions. The surfactant coating and plasma protein adsorption were found to have marked effects on the uptake of cyclosporine A loaded nanospheres by MPM. CONCLUSION: Our present study indicated that colloidal drug carriers might affect the targeting of cyclosporine A to mononuclear phagocyte system.

Animals↗

PubMed2001

[Morphology of abdominal aortic aneurysm and its clinical importance].

OBJECTIVE: To investigate the morphology of abdominal aortic aneurysms(AAA) and anatomical importance in endovascular surgery. METHODS: The images of AAA were measured by spiral CT angiography in 30 patients from January 1998 to December 2000. RESULTS: The mean diameter of AAA was 5.9 cm (range: 4.0-12.2). The diameter of AAA was positively correlated with neck angle (r = 0.47, P < 0.05) and negatively correlated with neck length(r = -0.41, P < 0.05). Twelve patients(40%) were anatomically feasible for endovascular repair (EVR); 18 patients were excluded for EVR due to angulated proximal necks (mean 88.8 degrees, range 70 degrees-110 degrees) (16 patients; 53.3%), short neck (1; 3.3%), and unilateral common iliac artery occlusion with thrombosis in neck (1; 3.3%). CONCLUSION: The angulated neck was a major single factor for excluding Chinese patients from EVR.

Adult↗

PubMed2001

[Apoptosis of pancreatic acinar and expression of TNF-alpha mRNA, IL-10 mRNA in rats with acute pancreatitis].

OBJECTIVE: To investigate the apoptosis of pancreatic acinar and the expression of TNF-alpha mRNA, IL-10 mRNA in pancreatic tissue of rats with acute pancreatitis. METHODS: The model of acute edematous pancreatitis(AEP) was established in 20 rats and that of acute necrotizing pancreatits(ANP) in another 20 by injection of sodium taurocholate into the pancreatic duct. Another 10 normal rats were used as controls. At 12 hours after the induction of pancreatitis, 10 rats in each group were sacrificed. Serum and pancreatic TNF-alpha and IL-10 levels were measured. The expression of TNF-alpha and IL-10 mRNA in pancreas was detected and the apoptotic rate of pancreatic acinar determined. RESULTS: The apoptotic rate of pancreatic acinar in normal, AEP and ANP groups was 2.98%, 17.29% and 8.39%, respectively. TNF-alpha and IL-10 levels increased after the induction of acute pancreatitis. The level of TNF-alpha was lower while that of IL-10 higher in AEP group than in ANP group. Transcription level of TNF-alpha mRNA in ANP group and that of IL-10 mRNA in AEP group were upregulated. CONCLUSIONS: The transcription levels of TNF-alpha and IL-10 mRNA in pancreatic tissue of rats with acute pancreatitis are positively correlated with their levels in serum and pancreas, suggesting that the pancreas is the organ to release cytokines. The apoptotic rate of pancreatic acinar is negatively correlated with the severity of disease and apoptosis may be a benign response to pancreatic injury.

Acute Disease↗

PubMed2001

[Arthropod community structures in transgenic Bt cotton fields].

Arthropod community structures were investigated in transgenic Bt cultivars, Bollgard(B) and Chinese cotton 30 (CC30), and common cultivars, control (C) and no control (NC) cotton field in North China in 1998. The results showed that compared with common cultivars, the species richness and the number of total individual of arthropod community in transgenic Bt cultivars field were reduced 2.4-16.3% and 71.0-78.3% respectively, in which dominant species in phytophagous subcommunity varied. The number of individual of predatory and parastic subcommunity were all increased. The similarity coefficient between CC30 and NC was 0.8243, B and NC 0.7320, B and C 0.3380, C and NC 0.3128, CC30 and C 0.2665. The order of diversity and evenness value of these were CC30 (2.3712 and 0.6428), NC (2.3654 and 0.6251), B (2.1364 and 0.5791), and C (1.0877 and 0.2949), their dominant value was 0.8726 (C), 0.3528(B), 0.1178(NC) and 0.1048 (CC30) respectively. It was concluded that different integrated pest management (IPM) strategy should be implemented in transgenic Bt cotton instead of common variety cotton field.

Animals↗

PubMed2001

[A simple and rapid procedure for detection of DNA damage caused by Aldicarb].

A simple and rapid procedure for detection of low levels DNA damage caused by Aldicarb was developed and compared with some other methods. In the original position the gel was set in high-pH buffer to run electrophoresis after the diluent of bacteria or fragmentized organ was added into hole of agarose gel directly and cells were treated with detergent and high alkaline condition. The impact of Aldicarb to biological individual or ecosystem was assessed according to the quantity of DNA and the extent of DNA migration.

Aldicarb↗

PubMed2001

[Effect of calcium and temperature on adhesion of K-ras transformed rat lung cells].

OBJECTIVE: To investigate the effect of calcium and temperature on cancerous cell adhesion. METHODS: K-ras transformed rat lung cells (KNRL cels) were used as experimental group, and normal rat lung cells (NRL cells) as normal control. The cells were cultured under the condition of implementation with Ca2+ and at 4 degrees C, 37 degrees C and 41 degrees C, and without Ca+2 at 37 degrees C. Cell adhesion and aggregation were examined. RESULTS: The average value of adhesive ability (Nt/N0) of KNRL cells was 0.81 +/- 0.15 at 37 degrees C, without CA2+ and 0.60 +/- 0.14, with Ca2+ (P = 0.041). The value was 0.53 +/- 0.12 at 41 degrees C, significantly lower than that at 37 degrees C (P = 0.046). CONCLUSION: Appropriate increase of Ca2+ and high temperature will strengthen the adhesive ability of tumor cells.

Animals↗

PubMed2001

[Penetrance of Leber hereditary optic neuropathy in Chinese individuals with mitochondrial DNA 11778 mutation].

OBJECTIVE: To analyze the penetrance of Leber hereditary optic neuropathy (LHON) in families with homoplasmic mitochondrial DNA (mtDNA) 11778 mutation. METHODS: Maternal relatives of 16 families were analyzed based on ocular phenotype and primary mtDNA mutation analysis. RESULTS: One hundred and thirty individuals from the 16 families harbored the 11778 mutation. Of the 130 individuals, 65 were male and 65 female. Forty-three individuals (34 male and 9 female) were affected with LHON. The penetrance of LHON in the 16 families ranged from 13.3% to 66.7%, with an average penetrance of 33.1%. Males, with an average penetrance of 52.3%, were more affected than females who had an average penetrance of 13.8%. About 79% of the affected individuals were male with a male to female ratio of 3.8: 1. The number of affected females found in the families analysis is greater than that in the probands analysis where only 3 of 41 probands with LHON and mtDNA11778 mutation were female(male to female ratio =12.7:1). CONCLUSION: The penetrance of LHON in Chinese individuals with homoplasmic mtDNA11778 mutation is about one third,which is within the range of that in Caucasion.

DNA Mutational Analysis↗

PubMed2001

[Analysis of loss of heterozygosity on 19p in primary gastric cancer].

OBJECTIVE: To investigate the loss of heterozygosity (LOH) frequency of microsatellite loci in primary gastric cancer samples and locate the deleted regions on 19p in which might exist human gastric cancer related genes. METHODS: The LOH of microsatellite loci on chromosome 19p was analyzed using PCR-SSLP-silver stain method in 43 primary gastric cancers and their paired normal tissues. RESULTS: In 43 primary gastric tumors, LOH was detected on the site for D19S424(29.63%), D19S216(11.53%), D19S406 (33.33%), D19S413(8.57%), D19S221(13.15%), D19S226(8.00%), D19S411(6.45%), D19S883(6.89%), and D19S886(10.71%), microsatellite instability (MSI) was found at the same time at locus D19S886 (17.85%). CONCLUSION: The most common LOH occurrence at D19S406 and D19S424 might imply the existence of the potential genes related to the tumorigenesis of gastric cancer in these loci.

Chromosome Mapping↗

PubMed2001

Mechanisms of multiple organ damages in acute necrotizing pancreatitis.

OBJECTIVE: To determine the role of systemic inflammatory response syndrome (SIRS) and multiple organ dysfunction syndrome (MODS), and evaluate the progress from SIRS to MODS and the therapeutic strategies for acute necrotizing pancreatitis (ANP). METHODS: Rat ANP models were made by retrograde injection of 3.5% sodium taurocholate 2.5 ml/kg into the pancreatic duct. Serum interleukin-8 (IL-8), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-alpha (TNF alpha), amylase, endotoxin, and albumin were examined. The morphology and pathology of the pancreas, liver, lung, kidney and heart after ANP were observed. Finally, TNF alpha mRNA in the liver, lung, kidney and heart after ANP were observed by reverse transcriptase-polymerase chain reactions, and the efficiency of somatostatin and growth hormone were also observed in this experiment. RESULTS: ANP led to remarkable elevation of the inflammatory mediators which were positively correlated with the development of ANP and MODS. Somatostatin and growth hormone inhibited inflammatory mediators and TNF alpha mRNA overexpressions, reduced the risk of MODS, corrected hypoalbuminemia, reversed negative nitrogen balance, and controlled the reduction of cell groups with functions and reasonably intervened SIRS caused by ANP. CONCLUSION: TNF alpha mRNA plays an important role in ANP progression. The amelioration of ANP by combination treatment with somatostatin and growth hormone leads to the reduction of complications and marked increase in survival.

Animals↗

PubMed2001

Suppression subtractive hybridization for identifying differentially expressed genes in renal cell carcinoma.

OBJECTIVE: To construct a renal cell carcinoma (RCC) cDNA subtractive library using suppression subtractive hybridization. METHODS: Polyadenylated RNA [Poly (A)+ RNA] was isolated from tissues of RCC and normal kidney, and single-strand cDNAs and double-strand cDNAs were synthesized in turn. RCC cDNAs were divided into two groups and ligated to the specific adaptors I and 2, and then hybridized with normal kidney cDNA twice with two rounds of suppression PCR. Second round PCR products were cloned to T/A plasmid vectors to set up the subtractive library. One hundred clones were randomly picked to perform enzyme digest analysis, and some underwent sequence analysis and Northern blot to identify RCC specifically expressed genes. SMART RACE procedure was operated to clone full length novel RCC specifically expressed genes. RESULTS: A human RCC subtractive library with high subtractive efficiency was successfully set up. The amplified library contains 350 positive clones. Random analysis of 100 clones with enzyme restriction showed that 85 plasmids in the clones contained 50-400 bp inserts. Sequence analysis was performed for 10 clones. All the 10 sequences were unknown before and derived from 6 unique, novel genes among which the cDNA insert RCC18 had five copies. Northern blot analysis showed that RCC18 cDNA was highly expressed in RCC, but no signal could be detected in normal kidney. Using SMART RACE technique, we obtained the full length of the novel gene RCC18. CONCLUSIONS: The constructed cDNA subtractive library of human RCC is a highly efficient one and lays a solid foundation for large scale screening and cloning new and specific oncogenes or tumor suppressor genes of RCC. The novel specifically expressed genes provided an important clue for studying the mechanisms of occurrence and development of RCC.

Carcinoma, Renal Cell↗

PubMed2001

[Relationship between estrogen receptor genotypes and female bone mineral density].

OBJECTIVE: To observe the relationship between polymorphyism of estrogen receptor (ER) gene and bone mineral density (BMD) in women. METHODS: Seventy-eight postmenopausal women, 23 perimenopausal women, and 52 young women (aged 25-35 years) were enrolled into the study. BMD was measured by dual energy X-ray absorptiometry at lumbar spine, proximal femur, fore-arm and total body. We also examined the restriction fragment length polymorphism of the polymerase chain reaction product (PCR-RFLPs) of the ER gene with XbaI or PvuII enzyme in these women. RESULT: There was no significant relationship between RFLP by PvuII or XbaI and BMD in 78 postmenopausal women. In young healthy women, the mean BMD at Ward triangle of genotype pp (0.823 +/- 0.095) g/cm2 was higher than that of genotype PP greater trochanter(0.665 +/- 0.071) g/cm2(P = 0.037). The BMD at total body, lumbar, hip, trochanter, and Ward of genotype xxpp were significantly higher than those of other genotypes (P < 0.05). But such differences were not found in postmenopausal women. CONCLUSION: The genotype xxpp might indicate a higher BMD at total body, lumbar, hip, greater trochanter, and Ward in young women. There is no significant effect of ER genotype polymorphism defined by PvuII or XbaI on BMD in postmenopausal women.

Adult↗