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Biomedical subjects

C Gao

Publications and source records attributed to C Gao.

At least 163 records · Page 9Linked to original sources

[Molecular cytogenetic study of an extra small chromosome].

An extra small chromosome was observed in a three-generation family. Eight members of this family were involved, but their phenotypes were normal. Molecular cytogenetic study was carried out, using cytogenetic methods and chromosome in situ hybridization with 3H-labelled rDNA probe. The results showed that this chromosome was from the short arm of chromosome of D/G group. The origin and genetic effects of this chromosome and fertility of the carriers were also discussed were also discussed briefly.

Adult↗

[Interphase cytogenetic studies of human X chromosome].

The chromosome in situ hybridization with human X chromosome alpha satellite DNA probe (pBamX7) on human lymphocyte metaphases and interphase nuclei was performed for interphase cytogenetic studies. The individuals with numerical or structural abnormalities of X chromosome were studied. The results showed that the probe hybridized specifically to the centromeric region (p11----q11) of X chromosome. The number of silver grain clusters in interphase nuclei was correlated with that of X chromosome. Most of the clusters located near the nuclear membrane where inactive X chromatins (Barr-bodies) were usually found. The method of ascertaining the number of X chromosomes by in situ hybridization was much more reliable than that by counting the number of Barr-bodies. The modified R-banding technique was introduced and the significance of this work was also discussed.

Chromosome Aberrations↗

[An experimental study on the pathophysiology of septic ventilatory depression].

Ventilatory depression and apnea are well-known early pulmonary responses of sepsis in infants, yet their underlying mechanisms are not understood. To further elucidate the pathophysiology, we induced Escherichia coli septicemia in piglets and studied the sequential changes in intrapulmonary shunt (QS/QT), physiological dead space (VD/VT), minute ventilation (VE), and blood gases for up to 6 hours of lethal sepsis. Lung lymph was also collected and extravascular lung water (EVLW) was measured. Histology confirmed that interstitial edema developed 1 hour after E. coli infusion. These data suggest that high permeability pulmonary edema and hypoxemia following early intrapulmonary shunt increase may be the causes of septic ventilatory depression.

Animals↗

[The mortality of patients with malignant tumors in eleven cities of Jiangsu Province, 1984-1986].

The present paper analysed people in eleven cities making up one sixth of Jiangsu population. In 1984-1986 the mortality of malignant neoplasm was 163.28/10(5), (Chinese standard mortality were 116.57/10(5), the world standard mortality were 177.75/10(5)) which accounts for 25.04% of the total mortality during the same time. The trends of deaths from neoplasms show that oesophageal cancer in both sexes and leukemia in male are gradually decreasing, lung cancer in male and hepatoma in female are gradually increasing. The rank correlation analysis between chinese standard mortalities of some major malignant neoplasms indicates that the stomach cancer was positive correlated with oesophageal cancer in both sexes, the oesophageal cancer in male and the stomach cancer in female were negative correlated with lung cancer, and the breast cancer was negative correlated with oesophageal cancer in female. All this suggests that there may be likely etiologic association between these malignant neoplasms.

China↗

[Effects of electroacupuncture on epileptiform hippocampal unit activity by intracerebroventricular injection of coriaria lactone].

In our present study we build up a new experimental model in the rat for epilepsy by intracerebroventricular injection of Coriaria Lactone (CL) and examine the effects of electroacupuncture on epileptiform hippocampal unit activity. Three types of hippocampal units responding to CL were observed: a) positive units b) negative units and c) indifferent units. The activity of positive units may be the typical epileptiform hippocampal activity. The positive units can be inhibited by electroacupuncture (EA), while the negative units can be exhilarated by EA. No changes were observed in indifferent units. Inhibitory effects of positive units are different because of using different "acupoints". EA of Du-Mo and Taichong Kunlun in the other side of drug injection were significatively better than Taichong, Kunlun in the same side of drug injection. Effects of Du-Mo was significantly better than the effects of the points on the limb. Parameters of EA are significantly different in other side of limb points for inhibition of positive units: 5 V 1 Hz, 5 V 5 Hz greater than 1 V 5 Hz greater than 1 V 1 Hz. These data indicate that effects of EA are depend on amplitude of EA, and seem not to be concern with frequencies of EA. The amplitude and frequency of hippocampal EEG spikes can be inhibited by EA. The inhibitory role of EA on epileptiform discharges is also discussed in this paper.

Animals↗

Berberine-induced morphologic differentiation and down-regulation of c-Ki-ras2 protooncogene expression in human teratocarcinoma cells.

A pluripotent human teratocarcinoma cell clone, NT2/D1, which was derived from the Tera-2 cell line, was induced to differentiate into cells with neuronal cell morphology by treatment with berberine. As early as 1 day after a 24-h treatment of cells with berberine at a non-toxic dose of 0.1 mg/ml in culture medium, the cells started to show morphologic changes, developing into terminally differentiated neuronal cells with long, inter-connecting network-like cellular structures. This process is much faster as compared with that induced by treatment with retinoic acid (RA), which took at least several days to develop. Unlike RA, berberine could not induce murine teratocarcinoma cell line, F9, to differentiate into endodermal cells. It was also found that, although the NT2/D1 cell clone exhibited amplification and enhanced mRNA expression of c-Ki-ras2 gene as did the parent cell line, a marked down-regulation of c-Ki-ras2 mRNA expression was observed. However, there was no change in actin mRNA expression even after differentiation had occurred. Thus, morphologic differentiation of teratocarcinoma cells into neuronal cells is found to be associated with down-regulation of a protooncogene which plays some definite role in oncogenesis. The mechanism by which berberine induces differentiation in these cells needs further investigation.

Animals↗

[Change of myocardial glucose and free fatty acid metabolism and effect of electroacupuncture on them during experimental myocardial angina].

This study was designed to observe the effect of electroacupuncture applied at "Neiguan" point on myocardial Glucose (GLU) and Free fatty acid (FFA) metabolism of dogs with experimental myocardial angina, experimental myocardial angina model was set up in 20 healthy mongrel dogs with reducing the volume of blood flow of left anterior descending coronary (LAD) and intracoronary administration of bradykinin. The results showed that arterial-venous difference of glucose (GLUa-v) was increased significantly and arterial-venous difference of free fatty acid (FFAa-v) was decreased significantly after experimental myocardial angina. with prolongation of the period of myocardial ischemia and increase of the times of myocardial angina, in control group, GLUa-v was increased lightly and FFAa-v was markedly decreased (P less than 0.05), this showed that FFA uptake of ischemic myocardium was markedly decreased. Electroacupuncture at bilateral "Neiguan" point resulted significant decrease of GLUa-v and slight increase of FFAa-v. There were statistical significance between the two groups (P less than 0.05) in GLUa-v and FFA-v. Aterial blood free fatty acid had not significant change after experimental myocardial angina and electroacupuncture had not marked effect on it. The above results indicated that experimental myocardial angina result in metabolic disorders of myocardial glucose and free fatty acid. Electroacupuncture may reduce glucose uptake and increase free fatty acid uptake of ischemic myocardium. Thus improved metabolic disorder of ischemic myocardium.

Acupuncture Therapy↗

[Clinical pathological analysis of recurrent oral ulcer and Behçet's syndrome].

Histopathological features of 53 cases of recurrent oral ulcer (ROU) and 28 cases of Behçet's syndrome (BS) were studied. The findings of light microscopic examinations are as follows: (1) The inflammatory cell reactions in early lesions are characterized by predominant lymphocytes and monocytes which differ from those in later lesions. (2) The vascular lesions are more significant in BS than in ROU. (3) The number of mast cells in the oral lesions of BS is more than that in ROU and controls. (4) Bacteria are observed in 11 specimens stained with HE and multinucleated epithelial giant cells are found in one specimen. It is considered that the lymphomonocytes in epithelial layer may play a role in the destruction of the epithelial cells through autoimmunization.

Adolescent↗

[New cloning vectors constructed in Bacillus].

Two new plasmids pNQ216 (4.1kp) and pNQ402 (2.8 kb) were constructed by combining the replication origin of the plasmid pNK289, a cryptic plasmid resides in B. pumilus 289, and the cat-86 gene from plasmid pPL601. These two plasmids can be maintained steadily in both B. subtilis and B. pumilus. The penetrance of these plasmids on LB medium with Cm (20 micrograms/ml) is 30% higher than that of pPL600. Thus both of these plasmids can be used as new cloning vectors in Bacillus.

Bacillus↗

[Long-term results of the treatment of mandibular condyle fracture].

Long-term result of conservative and surgical treatment of varying types of mandibular condyle fracture in 34 cases was investigated. The study shows that 90% cases of condyle fracture, including that complicated with dislocation and displacement, could be successfully treated with simple immobilization by intermaxillary elastic bands. The long-term result of close reduction is closely related to the interval between the trauma and the start of treatment, the earlier the beginning of the treatment, the better the result. The unfavourable immediate result in form of imperfect occlusion and excursion, etc. could be corrected by forced mandibular movement. 10 cases complicated with badly dislocation or communicated fracture were treated with condylectomy, satisfactory results were achieved in 80% of them.

Adolescent↗

Novel enzymatic approach to the synthesis of flavonoid glycosides and their esters.

Flavonoids such as (+)catechin can be efficiently solubilised in supersaturated solutions prepared with donor glycosides, e.g., p-nitrophenyl glycosides, di- and higher oligosaccharides, and poly(ethylene glycol) dimethyl ether in sufficiently high concentration for their efficient enzymatic glycosylation. Under these conditions several glycosidases readily accept (+)catechin as substrate and the target glycosides were prepared in one step in up to 26% yields. The regioselectivity of the reaction depends on the enzyme and substrate combination used; three positions, 5, 7, and 4', in the flavonoid can be glycosylated. The resulting and similar flavonoid glycosides were further modified by regioselective acylation with vinyl esters of arylpropenoic acids using lipases as biocatalyst. The efficiency of acylation was found to diminish in the order of vinyl cinnamate > vinyl ferulate > vinyl coumarate. This work demonstrates the feasibility of assembling complex flavonoid glycoside esters in just two steps by sequential use of commercially available glycosidases and lipases.

Acrylic Resins↗