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Biomedical subjects

J Qu

Publications and source records attributed to J Qu.

At least 55 records · Page 3Linked to original sources
PubMed2000

[The effect of temperature on the behavior of aminobenzoic acid on silver surface].

SERS spectra of p-Aminobenzoic Acid (PABA) and o-Aminobenzoic Acid (OABA) absorbed on a silver surface, roughened by nitric acid, have been measured with a Renishaw Raman microprobe spectrometer(lambda = 632.8 nm) at different temperature, which ranged from 30 degrees C to -190 degrees C and from -190 degrees C to 30 degrees C. Some reversible changes in some band positions have been observed. The results indicated that if the adsorbates were enhanced by chemical mechanism and the molecules lie flat on surface, e.g. p-Aminobenzoic Acid molecule, temperature had no effect on their orientation. However, the vibrational frequencies enhanced by electromagnetic mechanism shifted as temperature changed, e.g. the vibration of NH2 in o-Aminobenzoic. The fact was that temperature had effect on the orientation of the molecules.

4-Aminobenzoic Acid↗
PubMed1999

[Study on inflammatory response and alteration of biochemical components in BALF from Pneumocystis carinii pneumonia].

OBJECTIVE: To study the cellular and biochemical changes in airways in pneumocystis carinii pneumonia (PCP). METHODS: The cellular and biochemical changes in bronchoalveolar lavage fluid (BALF) between PCP and bacterial pneumonia in rat models induced by cortisone acetate(GC) injections were compared. The activities of alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and type IV collagenase(matrix metalloproteinases, MMP-2, MMP-9) in BALF were measured. The rats were divided into four groups: (1) normal controls: 6 healthy SD rats; (2) negative control: 6 rats with GC injection over 8 weeks without lung infection; (3) bacterial pneumonia: 11 rats with GC injection over 8 weeks complicating bacterial pneumonia without other pathogens isolated; (4) PCP: 14 rats with GC injection during 8-12 weeks complicating PCP without other pathogens isolated. RESULTS: In PCP the total cell counts (6.9 +/- 2.6) x 10(6)/L and the percentage of PMNs (18.6 +/- 6.0)% in BALF were increased compared with negative control(P < 0.01), but were lower than those in bacterial pneumonia group(P < 0.01). ALB in BALF in PCP (623 +/- 484) g/L was increased compared with negative control (36 +/- 16) g/L(P < 0.05) and bacterial pneumonia(91 +/- 43) g/L(P < 0.05). The activities of ALP and LDH in PCP [(217 +/- 81) U/L, (208 +/- 82) U/L respectively] were higher than those in negative control [(75 +/- 37) U/L, (86 +/- 61) U/L, P < 0.05)] and bacterial pneumonia [(90 +/- 45) U/L, (130 +/- 75) U/L, P < 0.05]. The activities of Type IV collagenase, including MMP-2, MMP-9, were increased in PCP compared with negative control (P < 0.001) and bacterial pneumonia (P < 0.001, P < 0.01), and the activities of MMP-2 and MMP-9 had positive correlations with total cell counts in BALF (r = 0.652, P < 0.05; r = 0.803, P < 0.001). CONCLUSIONS: It suggests that there are differences in the cellular and biochemical aspects of lung inflammation and injury between PCP and bacterial pneumonia.

Animals↗
PubMed1999

[The level of expression of adhesion molecules CD44v6 and E-cadherin in colorectal cancer and analysis of correlates with metastasis].

OBJECTIVE: To determine the expression of adhesion molecules CD44v6 and E cadherin in colorectal cancer and its relation with metastasis. METHODS: The expression of CD44v6 and E-cadherin in 32 patients with colorectal carcinoma was investigated using immunohistochemical staining, which was performed on surgical specimens. RESULTS: No significant correlation with CD44v6 and histologic type, TNM and Dukes staging was noted, but it was significantly correlated with lymph node and hematogenous metastasis. E-cadherin was strongly expressed in normal epithelium examined. However, E-cadherin expression in colorectal carcinoma was reduced (positive rate 46.9%). Metastatic colorectal carcinoma showed significant reduction (positive rate 20%). CONCLUSION: CD44v6, E-cadherin immunoreactivity are significantly correlated with lymph node and hematogenous metastasis.

Cadherins↗
PubMed1999

[Preoperative arterial infusion chemotherapy of colorectal carcinoma pathological and clinical effects].

OBJECTIVE: To investigate the pathological and clinical effects of preoperative selective intra-arterial infusion chemotherapy on colorectal carcinoma. METHODS: 30 patients with colorectal carcinoma underwent selective regional arterial angiography by Seldinger's method followed by intra-arterial infusion chemotherapy. RESULTS: changes of karyopyknosis, karyorrhexis, coagulation and necrosis of cytoplasm in cancer cells around vascular vessels were found in all cases. Interstitial edema, invasion of inflammatory cells, fibroelastosis around cancer cells, proliferous intima, thrombus and inflammation of vessels were also found at the same sites. CONCLUSIONS: Histological changes are significant after preoperative selective intra-arterial infusion chemotherapy for colorectal carcinoma. This therapy can relieve symptoms.

Adult↗
PubMed1999

[Establishment and identification of the monoepitopic monoclonal antibody of Plasmodium falciparum].

AIM: To prepare a monoepitopic monclonal antibody of Plasmoduim falciparum. METHODS: According to the theory of protein structure, a peptide with 6-9 residues representting the antigenicity of the original histidine-rich protein II (HRP-II) of P. falciparum was synthesized and used to immunize BALB/c mice after purity identification by capillary electrophoresis. RESULTS: Four hybridoma cell lines targeting a suitable peptide from pf HRP-II were obtained by using spleen embedment method and hybridoma technology. CONCLUSION: It is the first report to prepare a monoepitopic monoclonal antibody against original protein by selecting a suitable peptide from the primary sequence of protein.

Animals↗
PubMed1999

[Experimental study on carotid artery resection with vascular replacement by an autogenous vein graft].

OBJECTIVE: In order to observe the survival rate and the histologic changes of the reestablished common carotid artery system. METHOD: A planned resection of the carotid artery was done and the common carotid artery system was reestablished by interposing an autogenous external jugular vein graft in 15 white rabbits. RESULT: 12 survived, the other 3 rabbits died from graft thrombosis, the survival rate was 80%. Histologic examination demonstrated the smooth internal tunic in the anastomotic part of the carotid-jugular and no graft thrombosis. Angiography demonstrated the free circulation of the blood and no aneurysm in the anastomotic vein. CONCLUSION: It is concluded that it is possible that in selected patients, a planned resection of the carotid artery with replacement by interposing an autogenous external jugular vein graft will be done.

Anastomosis, Surgical↗
PubMed1999

[Expression and characterization of two outer capsid proteins VP2 and VP5 of bluetongue virus in insect cells].

OBJECTIVE: To study the biological characteristics of the outer capsid proteins VP2 and VP5 of bluetongue virus (BTV) expressed in insect cells and their potential use in the assembly of BTV and genetic engineering vaccine. METHODS: The genes which encode the two outer capsid proteins VP2 and VP5 of bluetongue virus (BTV) 10 were separately cloned into pFastBac1 vector and the corresponding recombinant baculoviruses were obtained. RESULTS: BTV VP2 could be expressed in Sf-9 cells better than VP5. Further works indicated that VP2 could elicit neutralizing antibodies to BTV10(1:64), and also could partially neutralize BTV1(1:16), but could not neutralize BTV13. The co-immunizing of VP2 and VP5 could induce higher neutralizing antibodies to BTV10 and BTV1. VP2 also showed a hemagglutination activity. CONCLUSION: VP2 expressed in insect cells could induce neutralizing antibodies to BTV and had the biological activity of hemagglutination, VP5 could enhance the ability of neutralizing antibody induction of VP2, they can be used for the assembly of virus-like particles and for the development of genetic engineering vaccine.

Animals↗
PubMed1998

PAK4, a novel effector for Cdc42Hs, is implicated in the reorganization of the actin cytoskeleton and in the formation of filopodia.

The GTPases Rac and Cdc42Hs control diverse cellular functions. In addition to being mediators of intracellular signaling cascades, they have important roles in cell morphogenesis and mitogenesis. We have identified a novel PAK-related kinase, PAK4, as a new effector molecule for Cdc42Hs. PAK4 interacts only with the activated form of Cdc42Hs through its GTPase-binding domain (GBD). Co-expression of PAK4 and the constitutively active Cdc42HsV12 causes the redistribution of PAK4 to the brefeldin A-sensitive compartment of the Golgi membrane and the subsequent induction of filopodia and actin polymerization. Importantly, the reorganization of the actin cytoskeleton is dependent on PAK4 kinase activity and on its interaction with Cdc42Hs. Thus, unlike other members of the PAK family, PAK4 provides a novel link between Cdc42Hs and the actin cytoskeleton. The cellular locations of PAK4 and Cdc42Hs suggest a role for the Golgi in cell morphogenesis.

Actins↗
PubMed1998

Advance in the study of inhibin, activin and follistatin production in pregnant women.

This review summarizes the new information on the studies of inhibin, activin, and follistatin production in the placenta during human pregnancy. Inhibin and activin exert suppressive and stimulatory effects, respectively, on the release of FSH in the pituitary. Follistatin is bound to inhibin and activin and indirectly modulates the FSH release. The placenta produces these three proteins. The serum levels of inhibin, activin, and follistatin are elevated in pregnant women and decrease after delivery. The trophoblast cells from term placenta secrete inhibin and activin in the primary cultures. The production and mRNA expression of inhibin and activin are regulated by several stimulatory and suppressive hormones and growth factors in placental tissues. cAMP, Ca2+, and protein kinase-C may be involved in intracellular signal transduction in trophoblasts. Activin receptors are present on placental cells. Follistatin inhibits the binding of activin to ActRII receptor. Abnormal levels of inhibin and activin in maternal serum are observed in problem pregnancies and gestational diseases. Inhibin, activin, and follistatin may play roles in the regulation of reproductive endocrinology in pregnant women and the embryo/fetal development.

Activin Receptors↗
PubMed1998

Dose and cost considerations for relocation after nuclear accidents.

The results of a comprehensive study of the dose and cost considerations for relocation after nuclear accidents are presented in this paper. These results include the quantification of the dependence of area affected by relocation on dose intervention level and source term, the countermeasures implementation cost-benefit estimate, as well as the application of cost-benefit analysis to optimize the dose intervention level for relocation. In order to explicitly consider the distribution of individual dose among the exposed population to determine the optimal dose intervention level for relocation, the concept of individual dose evaluation function has been introduced in the present work.

Cost-Benefit Analysis↗
PubMed1998

Effects of carbon source on expression of F0 genes and on the stoichiometry of the c subunit in the F1F0 ATPase of Escherichia coli.

Expression of the genes for the membrane-bound F0 sector of the Escherichia coli F1F0 proton-translocating ATPase can respond to changes in metabolic conditions, and these changes are reflected in alterations in the subunit stoichiometry of the oligomeric F0 proton channel. Transcriptional and translational lacZ fusions to the promoter and to two F0 genes show that, during growth on the nonfermentable carbon source succinate, transcription of the operon and translation of uncB, encoding the a subunit of F0, are higher than during growth on glucose. In contrast, translation of the uncE gene, encoding the c subunit of F0, is higher during growth on glucose than during growth on succinate. Translation rates of both uncB and uncE change as culture density increases, but transcription rates do not. Quantitation of the c stoichiometry shows that more c subunits are assembled into the F1F0 ATPase in cells grown on glucose than in cells grown on succinate. E. coli therefore appears to have a mechanism for regulating the composition and, presumably, the function of the ATPase in response to metabolic circumstances.

Artificial Gene Fusion↗
PubMed1998

[The parapharyngeal space tumour of children: reports of 4 cases].

In 1986-1996, four childish patients with parapharyngeal space tumour were treated in our hospital. In the beginning, we ought to define the size and range by CT scanning. The second, we excized it from neck-flank. The patients had a satisfying effect after surgical operation. Meantimes, it's necessary to protect the important vessel and nerve in surgical operation.

Child↗
PubMed1998

[The effects of phorbol 12-myristate 13-acetate and microcystine-LR on calcium channel in resistance vascular smooth muscle cells in SHRsp].

OBJECTIVE: To investigate the effects of phorbol 12-myristate 13-acetate (PMA) and microcystine-LR (MCYST-LR) on the whole-cell barium currenta of voltage-dependent calcium channels (VDCs) of the resistance vascular smooth muscle cells (VSMC) from the A4-A5 branches of mesenteric artery in stroke-prone spontaneously hypertensive rats (SHRsp) and its normotensive control Wistar rats. METHODS: Using the whole-cell Ba2+ current recording of the patch clamp technique. RESULTS: It was found that PMA, a protein kinase C (PKC) agonist or MCYST-LR, a protein phosphatase IA and IIA inhibitor by which the enhancement of phosphorylation induced could apparently activate the VDCs of the visceral resistance VSMC. CONCLUSIONS: This activation would be significantly potentiated during hypertension, in which the increase of L-type calcium channel openings induced by PMA was obviously manifest, as the T-type calcium channel activity weakly potentiated. In normotensive Wistar rats, the increase of T-type calcium channel openings was greater than that of SHRsp. However, the effect of MCYST-LR appeared that only the increase of L-type calcium channel current in SHRsp was significant. It is suggested that the action of PKC and/or phosphorylation on the different components of calcium currents should be emphasized in the investigation of the mechanism in the increase in peripheral resistance during hypertension.

Animals↗
PubMed1998

[Effects of GTP gamma S and GDP beta S on calcium channels of resistance vascular smooth muscle cells in SHRsp].

OBJECTIVE: To investigate the effects of GTP gamma S and GDP beta S on the whole-cell barium currents of voltage-dependent calcium channels (VDC) of the vascular smooth muscle cells (VSMC) from the A4-A5 branches in SHRSP mesenteric artery. METHODS: Using the whole-cell Ba2+ current recording of the patch clamp technique. RESULTS: (1) GTP gamma S, a G-protein agonist, increased whole-cell Ba2+ currents both of SHRSP and Wistar, but SHRSP with a higher ratio of amplitude change than Wistar. In addition, GTP gamma S shifted D infinity to right both in SHRSP and Wistar, but D infinity shifted more in SHRSP than that in Wistar. (2) GDP beta S, a G-protein antagonist, decreased whole-cell Ba2+ currents both of SHRSP and Wistar, but SHRSP with a higher inhibition ratio of amplitude change than Wistar. In addition, GDP beta S shifted F infinity to right and in SHRSP shifted more than control under HP = -80 mV. CONCLUSIONS: The G-protein mechanism may promote Ca2+ influx and contribute to the increase of peripheral resistance during hypertension.

Animals↗
PubMed1998

[Effect of SNP on KCa of resistance vascular smooth muscle cell membrane in SHRsp].

OBJECTIVE: To investigate the effect of sodium nitroprusside (SNP) on calcium activated potassium channels (KCa) of mesenteric arterial A4-A5 branches resistence vascular smooth muscle cell membrane in Stroke-prone Spontaneously Hypertensive Rats (SHRsp) and its normotensive control WKY rats. METHODS: Cell-attached patch clamp technique was used. RESULTS: It was found that SNP could activate the KCa of the resistance vascular smooth muscle in both SHRsp and WKY. Under the same dose of SNP (1 nmol/L), the conductance and channel current amplitude etc. of the activated KCa in SHRsp were smaller than that in WKY rats. Given the same dose of 8-Br-cGMP (10 mumol/L), the cGMP activation of SHRsp KCa was less potentiated than that of WKY, appeared very similar to SNP/NO activation. CONCLUSIONS: The results suggested the KCa of hypertensive resistance vascular smooth muscle membrane appearing weaker response to relaxing factor EDRF/NO.

Animals↗
PubMed1998

[Analysis of etiological agents and death-relating factors of pulmonary infections in immunocompromised patients].

OBJECTIVE: To explore the distribution of etiological agents and death-relating factors of pulmonary infections in immunocompromised hosts(ICH). METHOD: 80 patients of pulmonary infections in ICH confirmed by etiological and(or) pathological diagnosis were retrospectively analyzed. RESULT: The distribution of etiological agents of pulmonary infections (except for cytomegalovirus, CMV): common bacteria 56%, mycobacterium tuberculosis 29%, fungus 11%, pneumocystis carinii 4%. Mortality of pulmonary infections in ICH showed significant difference between age 67% (> or = 60 years): 48% (< 60 years), bacteremia 86% (yes): 45% (no), white blood cell count 67%, 87% (> 10 x 10(9)/L, < 4.0 x 10(9)/L): 23% (4.0-10) x 10(9)/L, extent of lesions in x-ray film 65% (diffuse): 23% (local) (P < 0.05, P < 0.01), however, there was no obvious difference in sex, underlying diseases, types of etiological agents, mixed infections. CONCLUSION: Bacteria was one of the most common etiological agents of pulmonary infections in ICH, the latent reactivation and relapse of pulmonary tuberculosis in ICH should be emphasized sufficiently. The preliminary analysis of death-relating factors showed: age, bacteremia, white blood cell count, extent of lesions in x-ray film were related to the prognosis of pulmonary infections in ICH.

Adult↗
PubMed1998

[Diagnosis of Falciparum malaria by immunochromatographic test].

AIM: To evaluate the applicability of rapid immunochromatographic test(ICT) for diagnosing falciparum malaria in outpatient clinics in endemic area. METHODS: With thick blood smear method as control, ICT was used for the detection of P. falciparum. RESULTS: The sensitivity and specificity of ICT in detecting P. falciparum was 94.7% and 90.3%, respectively. No cross-reaction with P. vivax was found (P > 0.05). CONCLUSION: ICT is much more rapid and simple than thick blood smear method for the diagnosis of falciparum malaria, and can be applied in the outpatient clinics in endemic area.

Adolescent↗