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Biomedical subjects

A Wang

Publications and source records attributed to A Wang.

At least 181 records · Page 10Linked to original sources
PubMed1997

[The curative effects of anti-TNF monoclonal antibody in E. coli infected mice].

OBJECTIVE: To evaluate effects of monoclonal antibody (McAb) against TNFa on E. coli infected mice. METHODS: 30 mice (10 week old, Kunming) were divided equally into three groups. The first group, as a control, 200 microliters saline (NS)/mouse was injected intravenously; Second group (untreated group), only E. coli (10(7) organisms/200 microliters NS) were injected intra-abdominaly; Third group (treated group), E. coli (10(7) organisms) were injected intra-abdominal and McAb against TNF alpha 2 mg/kg dissolved in 200 microliters NS were injected intravenously. After 24 h, observed the survival rate, compared the serum TNF level in blood and investigated pathology of intestine, lung and liver. RESULTS: There was a higher survival rate in treated group, with the serum TNF level lowered significantly, and the untreated mice had severe pathologic changes in viscera. CONCLUSION: Using anti-TNF alpha McAb was effective in reducing mortality rate in mice after infected with E. coli, but could not prevent the pathologic changes.

Animals↗
PubMed1997

[Relationship of primary pulmonary carcinoma with P16 protein expression].

This study sought to address the relationship of primary pulmonary carcinoma (PPC) with P16 protein expression. The expression of P16 protein in 65 cases of PPC was examined with immunohistochemical staining. The rate of loss of P16 protein expression in PPC was 36.92% +/- 18.45%. The rate of loss of P16 protein expression in adenocarcinoma (AC) was 28.47 +/- 16.33%, that in squamous cell carcinoma (SCC) was 35.95% +/- 17.36%, and that in adenosquamous cell carcinoma (ASCC) 57.88% +/- 10.18%. There significant differences were in the rate of loss of P16 protein expression between those aged < 60 with SCC and those aged > 60 with SCC, between low differentiated PPC and intermediate differentiated PPC, between AC and ASCC, and between SCC and ASCC (P < 0.05). There were no significant differences in the rate of loss of P16 protein between males and females with PCC, between left and right PPC, and between PPC and metastatic pulmonary carcinoma of lymph node (P > 0.05). These suggest that P16 protein expression may be one of the important standards in estimating the prognosis of patients with PCC.

Adenocarcinoma↗
PubMed1997

[Preventive and therapeutic effects of radix Salviae miltiorrhizae on glycerol-induced acute renal failure in rats].

Three substances obtained from Radix Salviae Miltiorrhizae were administered to rats with acute renal failure (ARF) induced by intramuscular injection of glycerol. The rats treated with the substances had significantly lower serum urea and creatinine levels than the untreated animals. In the treated group, the survival percentage was higher than that in the untreated group. Examination of kidneys showed that the treated group had significantly lighter renal damage than the untreated group. These results suggest that the three substances exert preventive and therapeutic effects on the ARF in rats and the effects are probably the result of adenosine antagonism.

Acute Kidney Injury↗
PubMed1997

[Different chemotherapy protocols for intermediate and high grade malignant non-Hodgkin's lymphoma].

OBJECTIVE: To assess the optinums chemotherapeutic protocols for higher CR rate in the treatment of intermediate and high grade malignant non Hodgin's lyphoma(NHL). METHODS: Seventy-four patients with pathological intermediate and high grade malignant NHL were tried randomly with revised ProMACE-CytaBOM(treatment group) and CHOP(control group). RESULTS: The CR rate was 56.8% in the treatment group and 35.0% in the control group (P > 0.05). In patients with high grade maliganat NHL, the CR rate of ProMACE-CytaBOM was 60.0% as compared with 32.0% of the CHOP (P < 0.05). Patients in both group suffered from similar side effects with tolerable bone marrow supression and gastric irritation. CONCLUSION: ProMACE-CytaBOM is a safe regimen with relative high CR rate for high grade malignant NHL, but further research is indicated for remote results.

Adolescent↗
PubMed1997

The development of monoclonal antibody against rhTNF and its curative effects on E. coli infected mice.

Fifteen hybridoma cell lines producing monoclonal antibodies (McAb) against recombinant human tumor necrosis factor alpha (rhTNFa) have been established by fusing SP 2/0 cells with spleen cells from a BALB/c mouse immunized with rhTNFa. Following J. M. Davis's Works, semi-solid medium was used for initial cloning. Five of them were studied further. Their main chromosome numbers range were 96 to 105, all of them were IgG1 subclass. The affinities of these McAbs were estimated to be 1.25 x 10(8) mol/L, 1.12 x 10(8) mol/L, 2.34 x 10(8) mol/L, 8.55 x 10(7) mol/L, 1.04 x 10(8) mol/L, respectively. Two groups of mice challenging with E. Coli (10(7) organisms), one group treated with 2 mg/kg anti-TNF monoclonal antibody, the other did not. There was a higher survival rate in treated group, the serum TNF level was significantly lower too, and the untreated mice had severe pathologic changes in viscera.

Animals↗
PubMed1997

[HBsAg autologous red cell agglutination assay].

Three lot of HBsAg autologous red cell agglutination kits (ARCA kit) have been qualified in lab, clinical trial and the stability confirmation have been performed. The sensitivity of the kits is 1ng/ml HBsAg. A, B, O, AB type of peripheral blood or antiagglutinated specimens can be used for assay. No Holk effect has been found. The repeated rate of 10 samples assayed for five times reached 100%. The specimens collected from HAV, HCV, Schistosoma Japonicum infected patients or RF positive patients do not interfere the test. The specificity of the kits is very high. 1712 clinical specimens were inspected comparing with the EIA kits in market. The relativity between the two methods is 0.985. 18 of the 26 specimens which two methods did not accord with each other have been confirmed. The false positive and missing detected for ARCA kits is 1, 3 and for EIA kits are 6, 8 respectively. ARCA kits are stable in 4 degrees C and 22 degrees C for more than one year. The kits can stand in 35 degrees C, 45 degrees C for 45 and 10 days without losing activity respectively.

Hemagglutination Tests↗
PubMed1997

Patient variability and the design of clinical pathways after primary total hip replacement surgery.

Objective data are necessary for the design of clinical pathways of total hip replacement (THR) surgery. The functional recovery and timing for hospital discharge was studied in a consecutive series of 65 patients undergoing primary THR. The Modified Barthel Index (MBI) was serially measured after surgery to assess the recovery of functional independence. A MBI score of 90 out of a maximum of 100 is required before patients are fit for hospital discharge. The length of hospital stay varied from 5 days to 39 days. Fifty-eight percent of patients were fit for discharge by day 8, and 42% required 10 days or longer (mean = 14.2 days) in hospital. Patients in these two groups differed significantly with respect to age, the number of associated comorbidities, preoperative and early MBI scores, and muscle strength parameters. These data suggest that there is wide variability in patients presenting for primary THR. One single clinical pathway may not accommodate this patient variability, whereas two clinical pathways (one with a day 8 and another with an extended [day 10 +] time frame) may be more appropriate.

Activities of Daily Living↗
PubMed1997

[Lyme neuroborreliosis with acute meningitis as the presenting manifestation: report of a case].

To enhance the understanding of Lyme disease, a case of Lyme neuroborreliosis with acute meningitis as the presenting manifestation was reported. The diagnosis was confirmed by elevated serum antibody response to B. burgdorferi using both ELISA and Western blotting, excluding other causes of neurological abnormalities and the typical response of our patient to antibiotics. This case indicates the existence of Lyme disease in Beijing area. If the etiology of a meningitis with lymphocytic pleocytosis is not known, it is important that Lyme neuroborreliosis should be considered as one of the differential diagnoses and detection of antibody to B. burgdorferi in serum and cerebrospinal fluid performed in time. A brief review of the literature including epidemiology, clinical menifestations, diagnosis and treatment of Lyme disease was made.

Adult↗
PubMed1996

Heparin inhibits mitogen-activated protein kinase-dependent and -independent c-fos induction in mesangial cells.

Heparin suppresses mitogenic responses in renal mesangial cells, and when quiescent mesangial cells are stimulated with serum, heparin blocks the induction of c-fos seen at 15 min. Because heparin is taken up by cells over a much longer time course, we addressed mechanisms whereby extracellular heparin might suppress c-fos induction at such early times. Quiescent cells were treated with serum, 12-O-tetradecanoylphorbol-13-acetate, or low concentrations of Ca2+ ionophores that produced increases in intracellular Ca2+ concentration ([Ca2+]i) in the physiological range. Each treatment caused an increase in c-fos mRNA, but they did so by different mechanisms. Serum activated mitogen-activated protein kinase (MAPK) and increased [Ca2+]i without affecting protein kinase C. Activation of protein kinase C with phorbol ester activated MAPK without much effect on [Ca2+]i. Ionophores increased [Ca2+]i without affecting basal levels of protein kinase C or MAPK. Heparin (1 microg/ml) suppressed the induction of c-fos initiated by all three treatments. It did not affect the activity of protein kinase C, but inhibited activation of MAPK by either serum or phorbol ester, suggesting a common site of action at or below the probable convergence of the induced signals at Ras/Raf-1 activation. Heparin also inhibited the serum-stimulated entry of extracellular Ca2+ to the same extent as verapamil, consistent with the ability of verapamil to block L-type Ca2+ channels and the known presence of these channels in mesangial cells. However, this effect does not appear to be related to heparin's ability to inhibit induction of c-fos. First, verapamil had no effect on induction of c-fos by serum. Second, heparin had no effect on changes in [Ca2+]i achieved by ionophores. We conclude that heparin suppresses induction of c-fos in mesangial cells by blocking at least two different points in signal transduction cascades, one upstream of MAPK and the other independent of MAPK, but dependent on intracellular Ca2+.

Amino Acid Sequence↗
PubMed1996

Conformational trapping in a membrane environment: a regulatory mechanism for protein activity?

Functional regulation of proteins is central to living organisms. Here it is shown that a nonfunctional conformational state of a polypeptide can be kinetically trapped in a lipid bilayer environment. This state is a metastable structure that is stable for weeks just above the phase transition temperature of the lipid. When the samples are incubated for several days at 68 degrees C, 50% of the trapped conformation converts to the minimum-energy functional state. This result suggests the possibility that another mechanism for functional regulation of protein activity may be available for membrane proteins: that cells may insert proteins into membranes in inactive states pending the biological demand for protein function.

Magnetic Resonance Spectroscopy↗
PubMed1996

Substitution of basic amino acids in the basic region stabilizes DNA binding by E12 homodimers.

The E2A gene encodes two alternatively spliced products, E12 and E47. The two proteins differ in their basic helix-loop-helix motifs (bHLH), responsible for DNA binding and dimerization. Although both E12 and E47 can bind to DNA as heterodimers with tissue-specific bHLH proteins, E12 binds to DNA poorly as homodimers. An inhibitory domain in E12 has previously been found to prevent E12 homodimers from binding to DNA. By measuring the dissociation rates using filter binding and electrophoretic mobility shift assays, we have shown here that the inhibitory domain interferes with DNA binding by destabilizing the DNA-protein complexes. Furthermore, we have demonstrated that substitution of basic amino acids (not other amino acids) in the DNA-binding domain of E12 can increase the intrinsic DNA-binding activity of E12 and stabilize the binding complexes, thus alleviating the repression from the inhibitory domain. This ability of basic amino acids to stabilize DNA-binding complexes may be of biological significance in the case of myogenic bHLH proteins, which all possess two more basic amino acids in their DNA binding domain than E12. To function as heterodimers with E12, the myogenic bHLH proteins may need stronger DNA binding domains.

Alternative Splicing↗
PubMed1996

Asymmetric syntheses, opioid receptor affinities, and antinociceptive effects of 8-amino-5,9-methanobenzocyclooctenes, a new class of structural analogues of the morphine alkaloids.

Several 8-amino-5,9-methanobenzocyclooctenes have been prepared by asymmetric organic synthesis techniques. Opioid receptor affinity studies have revealed the virtual absence of enantioselectivity for receptor binding, particularly at the mu-receptor, for the (+)-3a-f and the (-)-3a-f series. It is noteworthy that inversion of configuration at the nitrogen-bearing carbon atom [5S,8S,9S)-8-amino-3-hydroxy-5, 9-methano-9-(methoxymethyl)-5-methylbenzocyclooctene, (+)-3a vs (5S,8S,9R)-8-amino-3-hydroxy-5, 9-methano-9-(methoxymethyl)-5-methylbenzocyclooctene, (dl)-22] resulted in a > 10-fold increase in kappa-receptor affinity. Antinociceptive studies demonstrated that (dl)-22 was a full kappa-agonist while (+)-3a and (-)-3a did not possess kappa-activity. Although both (dl)-22 and (+)-3a/(-)-3a had high affinity for the mu-receptor, these compounds did not act as high-affinity agonists or antagonists at this receptor.

Alkaloids↗
PubMed1996

Soluble tumor necrosis factor receptors inhibit phorbol myristate acetate and cytokine-induced HIV-1 expression chronically infected U1 cells.

Recombinant human tumor necrosis factor (TNF) binding protein-1 (r-h TBP-1) and recombinant human soluble dimeric TNF receptor (rhu TNFR:Fc) were used to determine the relative contributions of TNF to phorbol myristate acetate (PMA) and cytokine-induced human immunodeficiency virus type 1 (HIV-1) replication in chronically infected cell lines. Treatment of HIV-1-infected promonocytic U1 cells with r-h-TBP-1 or rhu TNFR:Fc reduced PMA-induced HIV-1 p24 antigen production in a concentration-dependent manner, with a maximal inhibition of approximately 90%. Maximal inhibition of p24 antigen production in T-lymphocytic ACH-2 cells was 47% with r-hTBP-1 and 42% with rhu TNFR:Fc. r-hTBP-1 and rhu TNFR:Fc also decreased p24 antigen synthesized by U1 cells in response to other stimuli, including phytohemagglutinin (PHA)-induced supernatant, granulocyte-macrophage colony-stimulating factor, interleukin-6, and TNF. Addition of r-hTBP-1 to U1 cells during the last 4 h of a 24 h incubation with PMA still inhibited p24 antigen production by 15%. U1 cells stimulated with 10(-7) M PMA released approximately 1 ng/ml endogenous TBP-1 with an initial peak observed at 1 h and a second peak at 24 h after PMA stimulation. r-hTBP-1 also partially reversed inhibition of U1 cellular proliferation caused by PMA. Both r-hTBP-1 and rhu TNFR:Fc blocked PMA induction of nuclear factor (NK)- kappa B DNA-binding activity in U1 cells in association with decreases in HIV-1 replication. We conclude that soluble TNF receptors can inhibit stimuli-induced HIV-1 expression and NK- kappa B DNA-binding activity in chronically infected U1 cells.

Base Sequence↗
PubMed1996

A reversible posterior leukoencephalopathy syndrome.

BACKGROUND AND METHODS: In some patients who are hospitalized for acute illness, we have noted a reversible syndrome of headache, altered mental functioning, seizures, and loss of vision associated with findings indicating predominantly posterior leukoencephalopathy on imaging studies. To elucidate this syndrome, we searched the log books listing computed tomographic (CT) and magnetic resonance imaging (MRI) studies performed at the New England Medical Center in Boston and Hôpital Sainte Anne in Paris; we found 15 such patients who were evaluated from 1988 through 1994. RESULTS: Of the 15 patients, 7 were receiving immunosuppressive therapy after transplantation or as treatment for aplastic anemia, 1 was receiving interferon for melanoma, 3 had eclampsia, and 4 had acute hypertensive encephalopathy associated with renal disease (2 with lupus nephritis, 1 with acute glomerulonephritis, and 1 with acetaminophen-induced hepatorenal failure). Altogether, 12 patients had abrupt increases in blood pressure, and 8 had some impairment of renal function. The clinical findings included headaches, vomiting, confusion, seizures, cortical blindness and other visual abnormalities, and motor signs. CT and MRI studies showed extensive bilateral white-matter abnormalities suggestive of edema in the posterior regions of the cerebral hemispheres, but the changes often involved other cerebral areas, the brain stem, or the cerebellum. The patients were treated with antihypertensive medications, and immunosuppressive therapy was withdrawn or the dose was reduced. In all 15 patients, the neurologic deficits resolved within two weeks. CONCLUSIONS: Reversible, predominantly posterior leukoencephalopathy may develop in patients who have renal insufficiency or hypertension or who are immunosuppressed. The findings on neuroimaging are characteristic of subcortical edema without infarction.

Adolescent↗
PubMed1996

Inhibition of fibroblast proliferation by human iris pigment epithelial cells in vitro: preliminary results.

BACKGROUND: The interaction between different cells plays an important role in many physiological and pathological processes. Since the proliferation of fibroblasts is very much involved in the pathogenesis of eye diseases such as proliferative vitreoretinopathy, the failure of filtration in glaucoma surgery, etc., we attempted to ascertain whether iris pigment epithelial cells (IPE) have some modulating effect on fibroblast proliferation. METHODS: Human IPE were explanted and the third-passage culture was transferred into serum-free RPMI-1640 medium. After 48 h of further incubation, the medium was collected and submitted to centrifugation; the supernatant was used as the conditioned medium of IPE (IPE-CM). Cultured fibroblasts from Tenon's capsule were seeded in a 96-well plate and incubated with IPE-CM in different concentrations. The proliferation of fibroblasts was estimated by thymidine incorporation and cell counting. RESULTS: The incorporation of tritiated thymidine by fibroblasts was reduced to 56.68% of baseline with 1:16 diluted IPE-CM and to 13.63% and 8.20%, respectively, with 1:8 and 1:2 diluted IPE-CM. These findings were in good accordance with the results of cell counting, performed in parallel. SDS-PAGE of IPE-CM revealed two specific bands with molecular weight 65 kDa and 40 kDa. CONCLUSION: IPE-CM showed an obvious dose-dependent inhibitory effect on fibroblast proliferation and was presumed to contain some active factors contributing to this effect.

Cell Count↗