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Biomedical subjects

D Q Wang

Publications and source records attributed to D Q Wang.

53 records · Page 3Linked to original sources
PubMed1991

Anticancer gelatin microspheres with multiple functions.

Biodegradable, hydrophilic gelatin microspheres (GM) with an average diameter of 70 microns were prepared by cross-linking gelatin with glutaraldehyde for hepatic intra-arterial infusion. An anticancer agent, mitomycin C (MMC), together with a radioisotope, 131I, were bound to the GM for chemotherapy and local internal radiotherapy. The 131I-labelled MMC-GM (131I-MMC-GM) could accumulate in the specific site and embolize the hepatic arteries after the hepatic intra-arterial infusion, while it caused various effects to the liver cells. The 131I-MMC-GM remained within the hepatic arteries for at least one month. In vitro release of drugs from the GM was also quantified using a dynamic dialysis method.

Animals↗
PubMed1990

Antitumor efficacy of vaccinia virus-modified tumor cell vaccine.

The antitumor efficacies of vaccinia virus-modified tumor cell vaccines were examined in murine syngeneic MH134 and X5563 tumor cells. UV-inactivated vaccinia virus was inoculated i.p. into C3H/HeN mice that had received whole body X-irradiation at 150 rads. After 3 weeks, the vaccines were administered i.p. 3 times at weekly intervals. One week after the last injection, mice were challenged i.p. with various doses of syngeneic MH134 or X5563 viable tumor cells. Four methods were used for preparing tumor cell vaccines: X-ray irradiation; fixation with paraformaldehyde for 1 h or 3 months; and purification of the membrane fraction. All four vaccines were effective, but the former two vaccines were the most effective. A mixture of the membrane fraction of untreated tumor cells and UV-inactivated vaccinia virus also had an antitumor effect. These results indicate that vaccine with the complete cell structure is the most effective. The membrane fraction of UV-inactivated vaccinia virus-absorbed tumor cells was also effective. UV-inactivated vaccinia virus can react with not only intact tumor cells but also the purified membrane fraction of tumor cells and augment antitumor activity.

Animals↗
PubMed1990

Heterogeneity of Hanganutziu-Deicher antigen glycoproteins in different species animal sera.

A heterophilic Hanganutziu-Deicher (HD) antigen is present in many animal sera except human and chicken sera. To visualize the antigenic molecules, nine species animal and human sera were analyzed by SDS-PAGE, followed by Western blotting and immunostaining with avain anti-N-glycolylneuraminyl-lactosyl ceramide antibody which recognizes the terminal N-glycolylneuraminic acid moiety of glycoconjugates as an epitope of the HD antigen. Several HD antigen-active glycoprotein bands were detected in the sera of fetal calf, calf, horse, goat, monkey, rabbit, guinea pig, rat and mouse, except for human serum. The HD antigenic proteins showed heterogeneities in their molecular weights and were not identical with any major band visualized with silver-staining, indicating that they are minor components of serum proteins in each animal. Neuraminidase treatment destroyed the antigenicity of all proteins, confirming that N-glycolylneuraminic acid (NeuGc) at the non-reducing terminal of carbohydrate chains is the antigenic epitope in serum glycoprotein molecules as already confirmed in glycosphingolipid (GSL) antigens. The finding of HD-antigenic glycoproteins in animal sera suggests that they also stimulate HD antibody production in patients who received animal antiserum for therapeutic aim.

Animals↗
PubMed1989

Detection of glycoproteins as tumor-associated Hanganutziu-Deicher antigen in human gastric cancer cell line, NUGC4.

NUGC4 cells derived from a human gastric cancer gave 6% Hanganutziu-Deicher (HD) antigen-positive cells by flow cytometric analysis using an affinity-purified chicken antibody to N-glycolyneuraminyl-lactosyl-ceramide (HD3 ganglioside). The cells showed no HD antigenic ganglioside by thin-layer chromatography enzyme-immunostaining; however, they were revealed to contain HD antigenic proteins with molecular masses of 150, 100, 90, 70, 65, 60, 47, and 40 kDa, by both immunoblotting after sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoprecipitation of [35S]-methionine-labeled proteins, followed by SDS-PAGE and autoradiography. Neuraminidase treatment destroyed the antigenicity of all proteins, indicating that these molecules are glycoproteins and have N-glycolyneuraminic acid at the non-reducing terminal of carbohydrate chains as an HD antigenic epitope.

Antigens, Heterophile↗
PubMed1989

[Studies on saponins from the leaves of Panax japonicus var. bipinnatifidus(Seem.)Wu et Feng].

Two new saponins, bipinnatifidusoside F1(XII) and F2(XIII), were isolated along with eleven known saponins from the dried leaves of Panax japonicus var.bipinnatifidus(Seem.)Wu et Feng collected in the Range of Qinling Mountains in China. By spectrometric analysis(FAB-MS,1H and 13CNMR,1H-1H COSY), their structures were elucidated as dammar-25(26)-ene-3 beta, 12 beta, 20(S),24 zeta-tetraol-(20-O-beta-D-glucopyranosyl)-3-O- beta-D-glucopyranosyl(1-2)-beta-D-glucopyranoside (bipinnatifidusodie F1) and dammar-22(23) ene-3 beta, 12 beta, 20(S),24 zeta-tetraol-(20-O-beta-D-glucopyranosyl)-3-O-beta- D-glucopyranosyl(1-2)-beta-D-glucopyranoside (bipinnatifidusoside F2), respectively. The known saponins were identified as ginsenoside F1,F2,F3,Rg2,Re,Rd,Rb1,Rb3, 24(S)-pseudoginsenoside F11, panasenoside and majoroside F1. Compared with bipinnatifidusoside F2, majoroside F3 was corrected as dammar-22(23)-ene-3 beta, 12 beta,20(S),24 zeta-tetraol-(20-O-beta-D- glucopyranosyl)-3-O-beta-D-glucopyranoside.

Chemical Phenomena↗
PubMed1989

[Further study on dammarane saponins of leaves of Panax japonicus var. major collected in Quinling Mountains China].

In continuation of our studies on the leaves of Panax japonicus var. major (Burk.) Wu et Feng, two new dammarane saponins are isolated. By means of FAB-MS and 13CNMR, their structures were elucidated as dammar-22(23)-ene-3 beta, 6 alpha, 12 beta, 20(S), 24 section-pentaol- (20-O-beta-D-glucopyranosyl)-6-O-alpha-L-rhamnopyranosyl (1-2)-beta-D- glucopyranoside (majorosids F5) and dammar-23(24)-ene-3 beta, 6 alpha, 12 beta, 20(S), 25-pentaol-(20-O-beta-D- glucopyranosyl)-6-O-alpha-L-rhamnopyranosyl(1-2)-beta-D-glucopyranoside (majoroside F6).

Chemical Phenomena↗
PubMed1987

Delta hepatitis virus infection in China.

To assess the prevalence, epidemiological features and prognostic implications of hepatitis D (Delta) in Sichuan Province, The People's Republic of China, 649 sera (515 from HBsAg positive patients and 134 from HBsAg negative subjects) were tested by radioimmunoassay (RIA) for antibody to the hepatitis D virus (anti-HD). Forty-seven sera (7.2%) showed some degree of reactivity. Serial dilutions of these sera indicated that prozoning was not responsible for the equivocal results. Thirty-four of the 47 sera were submitted under code to a second laboratory for independent analysis. According to those results anti-HD antibodies were detected in four of these sera. The overall prevalence of anti-HD in the HBsAg positive patients therefore was 0.8% (4/515). On the basis of clinical, biochemical and histological data 427 HBsAg positive sera were further divided into acute Type B hepatitis, chronic Type B hepatitis, healthy carrier state and hepatocellular carcinoma (HCC) subgroups. Two of 65 (3.1%) anti-HD positive sera belonged to the acute Type B hepatitis group; one of 104 (0.9%), the chronic Type B hepatitis group and one of 246 (0.4%), the healthy carrier group. No antibody was detected in sera from 12 HBsAg positive HCC patients. All HBsAg negative patients were negative for anti-HD antibody. The results of this study indicate that despite a high prevalence of hepatitis B virus infection, positive serology for delta virus is uncommon in Sichuan Province, The People's Republic of China.

Adolescent↗
PubMed1986

The prevalence of antibody to delta virus in western Canada.

To assess the prevalence and pathological role of hepatitis D virus (HDV) infection in western Canada, we tested a total of 310 sera from the province of Alberta, Yukon and Northwest Territories for antibody to HD (anti-HDV) by commercial solid phase radioimmunoassay. Two hundred and forty-five sera were hepatitis B surface antigen (HBsAg) positive. These were classified on the basis of clinical and biochemical data as either acute hepatitis, chronic hepatitis or in the healthy carrier phase of infection Sixty-five HBsAg negative sera from patients with other forms of chronic liver diseases served as controls. Anti-HDV was detected in only four of the HBsAg positive sera (1.6%) and in none of the controls. The prevalence of anti-HDV was significantly higher in patients with chronic hepatitis, three of twenty-two (13.6%) than in patients with acute hepatitis (0%) (p less than 0.05) or healthy carriers (0%) (p less than 0.005). Two of the four anti-HDV positive sera were obtained from patients with a history of parenteral drug abuse. These results indicate that HDV infection is uncommon in western Canada but, when it does occur, is more likely to be associated with chronic inflammatory liver disease. Parenteral drug abuse appears to be the major risk factor for HDV infection in western Canada at this time.

Acute Disease↗
PubMedDate not supplied

Acetylcholine-induced systemic vasodilation resistant to NG-nitro-L-arginine in an anaesthetized rats.

1. The effects of NG-nitro-L-arginine (L-NNA; 20 mg/kg bodyweight (BW), i.v.) and metyrapone (300 mg/kg BW, s.c.) on acetylcholine (ACh)-induced depressor responses were investigated in anaesthetized rats. 2. Acetylcholine (0.05, 0.5, 5 micrograms/kg BW, i.v.) dose-dependently evoked a sharp fall in mean blood pressure (BP) followed by a slow recovery under control conditions. 3. Basal BP level was elevated when rats were treated with L-NNA, indicating endogenous nitric oxide (NO) participated in BP regulation. However, pretreatment with L-NNA did not attenuate but rather augmented the ACh-induced maximum vasodilation. In contrast, the time for recovery of mean BP to the pre-ACh administration level was shortened by L-NNA. These observations suggested that ACh-induced vasodilation consisted of two phases: a sharp and transient fall (phase 1) that was resistant to L-NNA followed by a longer depressor response (phase 2) that was suppressed by L-NNA. 4. To examine whether augmentation of phase 1 by L-NNA resulted from the elevation of basal BP, an appropriate dose of phenylephrine was infused to obtain similar BP elevation. Phenylephrine infusion augmented the phase 1 in a similar manner to L-NNA pretreatment but showed little effect on phase 2, supporting the selective inhibition of phase 2 by L-NNA. 5. The s.c. pretreatment with metyrapone for 3 days failed to attenuate phase 1. Thus, the involvement of endothelium-derived hyperpolarizing factor that could be formed by a metyrapone-sensitive oxidase in phase 1 was unlikely. 6. These results suggest that some factor(s), which is not inhibitable by L-NNA or metyrapone, may induce the phase 1 depressor response to ACh while NO is responsible for the phase 2 response. The mechanism inducing the phase 1 response remains to be identified.

Acetylcholine↗