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Biomedical subjects

M Ding

Publications and source records attributed to M Ding.

At least 217 records · Page 12Linked to original sources
PubMed1992

Genetic polymorphism of complement component C6, C7 and C8(1) in Chinese Han population in northeast China.

Distributions of complement phenotypes, C6, C7, and C8(1) were studied using thin agarose gel isoelectric focusing (AGIEF) or ultra-thin polyacrylamide gel isoelectric focusing (PAGIEF) and subsequent immunoblotting techniques in 203 Chinese Han population in Liaoning Province of northeast China. The gene frequencies were as follows: C6*A 0.4704, C6*B 0.5049, C6*B2 0.0148, C6*B3 0.0049, and C6*M 0.0049; C7*1 0.8251, C7*2 0.1108, C7*3 0.0320, and C7*4 0.0320; C8(1)*A 0.5567 and C8(1)B 0.4433, respectively. All the observed numbers of the phenotypes were in agreement with the expected numbers under the Hardy-Weinberg equilibrium. The gene frequencies among Chinese subpopulations and other various populations were compared.

Asian People↗
PubMed1992

[A prospective trial of hemodilution therapy in acute cerebral infarction].

Ninety two 50-year-old-or-more patients with acute (less than 72 hours) cerebral infarction involved middle cerebral artery region and hematocrit of 40% or more were prospectively randomised to either hemodilution group (by rapid venesection, venous infusion of autologous plasma and 500 ml dextran 40) or standard therapy group. Effects of hemodilution on acute cerebral infarction were evaluated by clinically neurological deficit scores, hemorheological parameters and size of infarction. The results of our clinical trial are: 1. Clinical efficacy of hemodiluted patients is significantly superior to that of standard treatment patients. Effective rates are 63.04% and 41.30% respectively (P less than 0.05). 2. At 48th hour after hemodilution there are profound decreases in hematocrit, blood viscosity at high shear rate and blood viscosity at low shear rate. These changes last more than four weeks. Whereas in standard group, hemorheological parameters do not evidently change. 3. Sizes of cerebral infarction do not distinctly change in both groups between at entry and at the fourth weekend after treatment.

Acute Disease↗
PubMed1992

Polyethylene glycol-conjugated superoxide dismutase attenuates reperfusion injury when administered twenty-four hours before ischemia.

Covalent linkage of polyethylene glycol to superoxide dismutase prolongs the serum half-life of the enzyme and may facilitate intracellular access. We tested the myocardial protective effect of polyethylene glycol superoxide dismutase administered once, 24 hours before ischemia. Because hearts were studied ex vivo in a crystalloid perfused system, cardioprotection could be ascribed to intramyocardial or membrane-bound polyethylene glycol superoxide dismutase accumulation. Thirty isolated rabbit hearts from the four following groups were studied: (1) control: untreated rabbits (n = 7); (2) PEG-control: 24-hour intravenous preinfusion of methoxypolyethylene glycol 5000 (5 mg/kg) to examine the effect of polyethylene glycol alone, without conjugation to superoxide dismutase (n = 8); (3) PEG-SOD 10,000: 24-hour preinfusion of polyethylene glycol superoxide dismutase (10,000 U/kg) (n = 8); (4) PEG-SOD 30,000: 24-hour preinfusion of polyethylene glycol superoxide dismutase (30,000 U/kg) (n = 7). After measurement of baseline function with use of an intraventricular balloon, hearts were subjected to normothermic ischemia until a 4 mm Hg rise in intracavitary pressure was observed. Function was assessed at 15-minute intervals throughout reperfusion and expressed as percent return of developed pressure. After 60 minutes of reperfusion, recovery of function was greater for the PEG-SOD 30,000 group (85.6% +/- 2.6%) when compared with either the untreated or PEG-control group (68.9% +/- 2.3% and 71.4% +/- 2.0%, respectively). A similar difference was seen throughout reperfusion. Although an improved return of function was shown in the lower dose PEG-SOD 10,000 group, the margin of difference when compared with any of the control groups was determined to be insignificant at all times of reperfusion and at 60 minutes (75.9% +/- 3.2%). These data demonstrate that high, but not low, doses of polyethylene glycol superoxide dismutase significantly reduce reperfusion injury when administered 24 hours before initiation of global ischemia. Moreover, since the perfusate was superoxide dismutase free, this effect was most likely intramyocardial or membrane bound and therefore might be added to protection afforded by circulating superoxide dismutase.

Animals↗
PubMed1992

[A dynamic observation on the fate of samarium in mouse liver].

It is generally considered that the rare earth compounds are plasma membrane-impermeable, thus affecting the cells only on their surface. Recently, we found that after repeated injections to mice of large dose of samarium trichloride, a soluble compound of rare earth, samarium aggregates appeared in Kupffer cells and hepatocytes of liver. In this study, we aimed at observing the route by which samarium enters the liver cells and the process of the formation of samarium aggregates. Samarium trichloride was given to Swiss mice at one dose of 70 mg/kg intravenously. Thereafter, at different intervals from 15 min to 48 h after the injection, the samarium in liver was traced dynamically by electron microscopy and X ray microanalysis. From 15 min to 2 h both Kupffer cells and hepatocytes endocytosed samarium-containing particles and formed phagosomes, in which the ingested particles were progressively concentrated. Besides, the small phagosomes fused with each other. Phagocytosis was especially active in Kupffer cells. During the 4 h to 24 h many Kupffer cells were degenerated and broken. In hepatocytes the phagosomes gathered mostly around the bile canaliculi. Groups of highly electron-dense particles were found in the lumen of bile canaliculi, implying the excretion of samarium by bile. At the 48 h, the samarium-containing phagosomies were found still in both kinds of cells in the liver.

Animals↗
PubMed1992

Formation study of toroidal condensation of DNA.

A detailed study of the formation of toroidal condensation produced from the 2700 base pair fragments of plasmid PUC13 DNA, induced by metal ions, is introduced. We have extracted several typical intermediate structures based on investigation by electron microscopy, and compared their size distributions. The observations suggest that the formation process of DNA condensation is the process of folding and arranging DNA chains and that of disorder-order transition. The result also indicates that the condensed particles are polymeric, but not randomly aggregative, further proving the toroidal structures are formed in certain regularities.

DNA, Bacterial↗
PubMed1992

Reactivity of gastroepiploic and internal mammary arteries. Relevance to coronary artery bypass grafting.

The gastroepiploic artery is an alternate conduit for coronary artery bypass grafting. To test the hypothesis that its vasoreactive properties are different from those of the internal mammary artery, we obtained gastroepiploic artery segments from human gastrectomy specimens. Trimmed internal mammary artery segments were obtained during coronary artery bypass. Ring segments were mounted on a strain gauge and stretched to optimum resting length (90% of the internal circumference at 100 mm Hg). Potassium chloride, serotonin, and norepinephrine were chosen to simulate physiologic vasospasm induced by depolarization, platelet aggregation, or adrenergic stimulation, respectively. Contractions to potassium and a concentration-response curve to serotonin or norepinephrine were obtained. Sodium nitroprusside was used to assess relaxation. Gastroepiploic artery segments had stronger contractions to the depolarizing agent (potassium chloride), adrenergic stimulation (norepinephrine), and product of platelet aggregation (serotonin). The gastroepiploic and internal mammary arteries showed equal sensitivity, measured by concentration causing half-maximal contraction to norepinephrine and serotonin. There was no difference in relaxation to sodium nitroprusside. These data suggest that prevention of platelet-, adrenergic-, or potassium-induced contraction may be more important when the gastroepiploic artery is used as an alternate conduit for coronary artery bypass, reinforcing consideration of nitrovasodilators and platelet inhibitors in the perioperative interval.

Arteries↗
PubMed1991

Triiodothyronine-enhanced left ventricular function after ischemic injury.

Hypothyroidism is associated with profound left ventricular dysfunction. Brain-dead organ donors and patients undergoing cardiopulmonary bypass are chemically hypothyroid with significantly reduced circulating free triiodothyronine (T3). To test the hypothesis that T3 enhances left ventricular function in a hormonally deficient environment, a total of 36 healthy New Zealand White rabbit hearts were studied using a modified Langendorff preparation with Krebs-Henseleit perfusate and intra-ventricular balloon. In 9 normal rabbit hearts a cumulative dose-response curve with logarithmically increasing doses of T3 was obtained. The vehicle solution for T3 dissolution served as control (n = 9). Left ventricular function was assessed from peak developed pressure at baseline and after T3 administration. Triiodothyronine had no effect in normal hearts on peak developed pressure or end-diastolic pressure. In 18 rabbits, the acute effect of T3 administration after ischemia was investigated. Preischemic left ventricular function was measured to serve as baseline, and hearts were subjected to 37 degrees C global ischemia. Triiodothyronine (n = 9) or vehicle (n = 9) was infused during reperfusion, and left ventricular peak developed pressure was measured at 30 and 60 minutes of reperfusion. Recovery of function (expressed as percent return of left ventricular peak developed pressure) was significantly improved within 15 minutes of reperfusion (65.0% +/- 2.1% versus 80.2% +/- 4.1%) and remained significantly improved throughout the reperfusion period (p less than 0.05 by analysis of variance). These data suggest that although T3 possesses no inotropic properties, it significantly improves postischemic left ventricular function. The rapidity of the functional improvement suggests that these effects may be due to plasma membrane-mediated mechanisms.

Animals↗
PubMed1991

Polymorphism of complement component I in Mongoloid populations: a new genetic variant IF A2.

The genetic polymorphism of the complement component I (IF) was investigated in 282 Chinese, 239 Koreans and 198 Japanese. The 3 common IF phenotypes (A, AB and B) and a new rare IF phenotype (BA2) were observed. The obtained allele frequencies are as follows: IF*A = 0.0993 and IF*B = 0.9007 in Chinese; IF*A = 0.0921 and IF*B = 0.9079 in Koreans; IF*A = 0.0985, IF*B = 0.8990 and IF*A2 = 0.0025 in Japanese. These 3 Mongoloid populations showed a much higher degree of IF polymorphism than Caucasian populations.

Alleles↗
PubMed1990

Distribution of human Zn-alpha-2-glycoprotein types in Chinese and Korean populations.

The genetic variation in Zn-alpha 2-glycoprotein (ZAG) was investigated by polyacrylamide gel isoelectric focusing and immunoblotting. The samples comprised 590 Chinese from 2 localities (Shenyang: n = 390; Kaohsiung: n = 200) and 873 Koreans from 2 localities (Seoul: n = 523; Cheju: n = 350). The allele frequencies were: ZAG*1 = 0.9962, ZAG*5 = 0.0038 in Shenyang; ZAG*1 = 1.0000 in Kaohsiung; ZAG*1 = 0.9971, ZAG*3 = 0.0029 in Seoul, and ZAG*1 = 0.9929, ZAG*3 = 0.0071 in Cheju.

China↗
PubMed1990

[EEG topographic study of Alzheimer's disease and multi-infarction dementia].

The results of topographic analyses of electroencephalographic data obtained from 28 patients with Alzheimer's disease, 29 with multi-infarction dementia and 31 with multiple infarction were compared with those of 30 healthy controls. Both demented groups demonstrated a significant increase in delta and theta power in all the regions. The AD group showed the most significant increase at the bilateral frontal regions. MID and MI groups demonstrated normal alpha power in all regions. But in AD, alpha power in most regions was decreased. The MID group had more asymmetric findings than the AD group.

Aged↗
PubMed1990

[The relationship of Sindbis virus assembly and the viral protein 6K with intermediate filaments].

The relationship of Sindbis virus (Sbv) assembly with intermediate filaments was studied by means of whole-mount and DGD embedment-free technique of EM together with the procedure of gentle extraction. In the early stage of Sbv infection, the "virus assembly center" was suspended in the intermediate filament network. In the late stage, the assembling and assembled virus nucleocapsids were associated with intermediate filaments. It is presumable that the virus nucleocapsids may move from the "virus assembly center" to cytoplasmic membrane along the intermediate filaments. Further study using immunolabelling technique indicated that the nonstructural protein 6K of Sbv was probably associated with intermediate filaments as well.

Cell Line↗
PubMed1990

[Analgesic anti-inflammatory effects of moschus bone-setting liquor in local traumatic ecchymosis].

Moschus Bone-setting liquor, ip, 1 ml/kg significantly decreases the rate and frequency of body twisting reaction induced by ip acetic acid, and markedly increases the pain threshold of thermal stimulation in mice. The liquor also reduces apparently the inflammation of mice ear induced by the oil of Fructus Crotonis, and rapidly relieves the traumatic ecchymosis in guinea pigs. Dose response relationship was obtained in the experiment. These results provide evidences for the clinical application of Moschus Bone-setting liquor in the treatment of many traumatic diseases.

Animals↗
PubMed1989

[Dermatoglyphics parameters and cluster analysis of seven minority nationalities].

This paper reports the normal values of dermatoglyphics parameters of seven minority nationalities in Yunnan Province which are Bai, Blang, Yi, Hui, Lisu, Nu and Jinuo. The test of difference signification and cluster analysis show different parameters in several nationalities and the greatest most remarkable difference between Jinou and other nationalities. Han is very different from several nationalities. In each nationality, the symmetry pattern of same name finger or area is highly unanimous, the symmetry between left and right does not show random combination.

China↗
PubMed1988

Intraocular lens material evaluation by iris abrasion in vitro: a scanning electron microscope study.

Prosthetic posterior chamber intraocular lenses can abrade the iris pigmented epithelium, resulting in pigment dispersion, callus formation, and iris adhesions. To evaluate iris abrasion from intraocular lens materials, we developed an in vitro test and studied three materials: polymethylmethacrylate (PMMA), silicone, and PMMA surface-modified by covalent binding of a hydrophilic polymer (surface-modified PMMA). Each lens was rubbed 1,000 times on the posterior iris of pigmented rabbits using a total force of 0.5 gram. Scanning electron micrographs of the abraded irides were scored using a subjective, nonparametric numerical scale. Polymethyl-methacrylate lenses removed iris epithelium completely, exposing underlying connective tissue. Silicone lenses damaged an area longer and narrower than the PMMA lens and also exposed connective tissue. Surface-modified PMMA lenses caused only slight surface damage, including flattening or breaking of protruding suspensory ligaments. The test conditions used cannot precisely mimic prolonged lens implantation in living subjects. Nevertheless, the results indicate that iris-lens interaction may be reduced in vivo by using a surface-modified PMMA lens. This hypothesis should be further verified by animal implantation studies.

Animals↗
PubMed1988

Fibronectin in corneal wound healing.

Fibronectin is an extracellular structural protein with the unique ability to bind to both cells and collagen. It plays a major role in the development of the cornea. The universal appearance of fibronectin within 8 hours of corneal wounding has promoted major interest in its wound healing properties. The early clinical evidence for fibronectin treatment of recurrent corneal erosion and certain forms of keratitis sicca is strong. The current major problem preventing commercial use is the antigenic nature of fibronectin derived from separate species. Human pooled fibronectin has been suggested as a commercial source of this ubiquitously occurring protein.

Animals↗