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Biomedical subjects

Z Ma

Publications and source records attributed to Z Ma.

At least 235 records · Page 13Linked to original sources
PubMed1995

[Research on rectal administration of bark of official Magnolia].

Fluorescence assay was applied to the determination of magnolol in rabbit blood, and the best way to administer the bark of official magnolia per rectal was established by orthogonal test. Then the two routes of administration were compared by AUC of magnolol and per rectal was found better than P.O. In addition, the modified isolated rectum-bag method was applied successfully to the research on rectal administration of bark of official magnolia.

Administration, Rectal↗
PubMed1995

[Experimental research of middle ear implant].

Click and tone burst were used to evoke the auditory brainstem responses of experimental animals. The stimulations of different sound intensities were used. Amplitudes, latencies and thresholds of normal ear were measured and the incus of right ear was removed and Nd-Fe-B middle ear implanted. The thresholds of normal ears were 14.74 +/- 4.12 dB nHL on average. The thresholds of removed incus were 57.00 +/- 8.64 dB nHL on average. The thresholds of the implanted middle ears were 16.25 +/- 8.56 dB nHL. It was found that the characterstics of frequency responses of the implanted middle ear cover the whole area of language frequency in the experiment. It accorded with the features of audibility of human ear.

Animals↗
PubMed1995

[SIMA leakage into stroma and lymph node metastasis in cervical adenocarcinoma].

The relationship of small intestine mucin antigen (SIMA) leakage into stroma and tumor lymph node metastasis was studied by SIMA immunohistochemical stain in the cervical adenocarcinoma of uterus. The results showed that the more SIMA leakage into stroma, the more possibility of lymph node metastasis. There was no difference between the SIMA staining intensity in the primary tumor or metastatic tumor. Mucin leakage into stroma may play an important role in cervical adenocarcinoma metastasis.

Adenocarcinoma↗
PubMed1995

[Limb-salvage surgery in 60 patients with osteosarcoma].

Limb-salvage surgery plays an important role in the treatment of osteosarcoma. From 1974 to 1993, 104 patients with osteosarcoma were treated in our department. Sixty of them were treated with limb-salvage procedures. In fourty-four patients of stage II B receiving adjuvant chemotherapy, the five-year survival rate was 46.69%. The overall local recurrence rate was 15%. The infection rate was 12.9%, and mechanical complication occurred in 14.8% of the patients. The functional result was generally good. Improved concepts of en bloc resection and better reconstructive techniques suggest that limb-salvage procedures are not only possible but can provide excellent functional result in patients with osteosarcoma. Further work must be directed to reducing local recurrence and improving reconstructive techniques.

Adolescent↗
PubMed1995

[The effects of antitumor agents of croton alkaloids and cisplatin on human red blood cell membranes].

The effects of antitumor drugs of croton alkaloids (CA) extracted from croton, and cisplatin on the structure of human erythrocyte membrane and bovine serum albumin (BSA) were studied with the techniques of circular dichroism, fluorescence spectroscopy and ultraviolet absorption. From measuring circular dichroism between 200-240nm, it was found that the alpha helix of membrane and BSA increased after CA addition. Cisplatin was also found effective in altering membrane alpha helical content. BSA showed a loss of fluorescence intensity and a blue-shift of emission peak after CA addition. The florescence quenching and peak shift may reflect the movement of tryptophan to a more nonpolar environment (the hydrophobic portions of proteins). This is consistent with the increase in helicity of BSA in the presence of CA. From measuring fluorescence polarization of membrane, it was found that membrane fluidity decreased in the presence of CA, but did not change in the presence of cisplatin. The results indicate that both CA and cisplatin lead to alterations in the secondary structure of membrane protein. The conformation change in membrane protein may account for the pharmocological effect of CA and cisplatin.

Alkaloids↗
PubMed1995

[Rectal administration of ash bark].

A TLC-densitometric method was applied to determine aesculin in rabbit blood. The best way for ash bark rectal administration was found by orthogonal design [L4(2(3))]. The two routes of administration (per rectal, P.O.) were compared by bioavailabilities and the result indicated that per rectal was better than P.O. Modified isolated rectum-bag method was applied successfully to finding the best way for rectal administration of ash bark.

Administration, Rectal↗
PubMed1994

Complex between bovine ribonuclease A and porcine ribonuclease inhibitor crystallizes in a similar unit cell as free ribonuclease inhibitor.

We obtained three different morphologies of co-crystals of bovine ribonuclease A and porcine ribonuclease inhibitor. X-ray quality crystals were grown in 1.3M ammonium sulfate, 100 mM sodium acetate (pH 5.0) and 20 mM dithiothreitol at 21 degrees C. These crystals have the symmetry of the tetragonal space group I4 with a = 133.3 A and c = 86.7 A and diffract to 2.5 A resolution; they have the same symmetry and only slightly different cell parameters than the crystals of free ribonuclease inhibitor. Polyacrylamide gel electrophoresis and the crystal density indicate that both ribonuclease inhibitor and ribonuclease A are present in the crystals. Although small, crystals are suitable for three-dimensional structural analysis.

Animals↗
PubMed1994

Studies on the relationship between sway disease of bactrian camels and copper status in Gansu province.

The clinical signs of camel sway disease in the Hexi Corridor of Gansu province were defined. The contents of eight minerals in soils, in forage and in the blood and hair of bactrian camels from this region were determined. The related blood indices were also measured. The concentration of molybdenum in soils and forage was 4.8 +/- 0.02 and 4.8 +/- 0.25 micrograms/g (dry matter), respectively, the copper to molybdenum ratio in the forage being only 1.3. The concentration of copper in blood and hair from the camels was 0.28 +/- 0.17 micrograms/ml and 3.50 +/- 1.00 micrograms/g, respectively. There was a hypochromic microcytic anaemia and a low level of ceruloplasmin in the blood. It is therefore suggested that sway disease of bactrian camels in this region is caused by secondary copper deficiency, mainly due to the high molybdenum content in soils and forage. The copper deficiency in the camels was aggravated during reproduction. Oral administration of copper sulphate can prevent and cure the disease.

Animal Feed↗
PubMed1994

Permanence of populations in a polluted environment.

Studies of several population-toxicant models are discussed. Under the hypothesis that the exogenous input of toxicant into the environment is periodic in time, the conditions for permanence of populations are obtained.

Animals↗
PubMed1994

Membrane physical properties determine cardiac beta-adrenergic receptor function in cirrhotic rats.

To elucidate the basic membrane mechanisms underlying cirrhotic cardiomyopathy, cardiac sarcolemmal plasma membrane physical properties, chemical composition, beta-adrenoceptor density, binding affinity, and isoproterenol-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) production were studied. Cirrhosis was induced by chronic bile duct ligation, while controls underwent a sham operation. The cardiac plasma membrane of cirrhotic rats was found to be more rigid than controls, primarily due to an increased cholesterol-to-phospholipid ratio. In cirrhotic animals, beta-adrenergic dysfunction was evident with a 21% decrease in beta-adrenoceptor density but no alteration in binding affinity. Despite the modest decrease in receptor number, beta-adrenoceptor-stimulated cAMP production was decreased by 37% in cirrhotic rats. When the membrane physical properties of the cirrhotic rats were restored to normal, by incubation with the fluidizing agent 2-(2-methoxy-ethoxy)ethyl 8-(cis-2-n-octylcyclopropyl)octanoate (A2C), isoproterenol-stimulated cAMP production also increased to levels indistinguishable from control animals. Restoration of membrane physical properties had no effect on either beta-adrenoceptor density or binding affinity. These results suggest that the increased rigidity of cardiomyocyte plasma membranes seen with cirrhosis is associated with decreased beta-adrenoceptor function. Moreover, restoring normal physical properties may result in restoration of beta-adrenoceptor-mediated contractile function.

Animals↗
PubMed1994

Education selectivity in internal migration in mainland China.

"The purpose of this paper is to study the selectivity in...internal migration in Mainland China with respect to the level of education, based on a sample of young adults (aged 17-29) taken from the micro data of the 1987 one-percent National Population Survey (NPS87)....[We focus first] on the education selectivity in migrations among the city, town and rural strata of the urban/rural hierarchy [and then examine] the education selectivity in migration among metropolitan, coastal and interior regions." (SUMMARY IN CHI)

Asia↗
PubMed1994

[Bacteriostasis of rhizoma Coptidis combined with trimethoprim (TMPO)].

The agar-dilution method was adopted to study contrastively the bacteriostasis of Rhizoma Coptidis and TMP, and also of the two drugs in combination. The results indicate that the combination works in good cooperation against Escherichia coli, Bacillus pyocyaneus, Staphylococcus aureus, Shigella flexneri and S. dysenteriae.

Anti-Bacterial Agents↗
PubMed1994

Cloning and high level expression of gene encoding ES antigen from Trichinella spiralis muscle larvae.

The partial structure gene encoding ES antigen derived from Trichinella spiralis (TSP) muscle larvae was cloned, characterized, and expressed in E. coli. The target DNA (0.7 kb) was directly obtained from the TSP total RNA by using RNA PCR technique. Based on the analysis with the RE digestion, the fragment was cloned into the fusion expression vector pEX31C. It was shown that a kind of 37kDa fusion protein was expressed in E. coli containing the recombinant plasmid by SDS-PAGE electrophoresis. The expressed protein was over 22% of the total cell protein, and it was aggregated in the form of inclusion bodies in E. coli. The purified protein could be recognized in ELISA both by sera from swine-infected with TSP and by the monoclonal antibody against TSP. These findings suggest that the recombinant protein is a potentially valuable antigen both for immunodiagnosis and vaccine development of trichinellosis.

Animals↗