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Biomedical subjects

Z Q He

Publications and source records attributed to Z Q He.

At least 19 recordsLinked to original sources
PubMed2000

Effects of oxodiperoxovanadate (V) complexes on the activity of green crab (Scylla serrata) alkaline phosphatase.

Green crab (Scylla serrata) alkaline phosphatase (EC 3.1.3.1) is a metalloenzyme that catalyzes the nonspecific hydrolysis of phosphate monoesters. The effects of some pollutants in seawater on the activity of the enzyme will result in the loss of the biological function of the enzyme, which will affect the exuviating crab shell and threaten the survival of the animal. In the present paper, the effects of four oxodiperoxovanadate (V) complexes on the activity of green crab alkaline phosphatase have been studied. The results show that these vanadate derivatives can lead to reversible inactivation. The equilibrium constants for binding of inhibitors with the enzyme and/or the enzyme-substrate complexes have been determined. The results show that sodium (2,2;-bipyridine)oxodiperoxovanadate, pV(bipy), and potassium oxodiperoxo-(1,10-phenanthroline)vanadate, pV(phen), are competitive inhibitors, while potassium picolinato-oxodiperoxo-vanadate, pV(pic), and oxalato-oxodiperoxovanadate, pV(ox), are mixed-type inhibitors. These results suggest that pV(bipy) is a considerably more potent competitive inhibitor than pV(phen) and that the competitive inhibition effect of pV(pic) is stronger than that of pV(ox), but the non-competitive inhibition effect of pV(ox) is stronger than that of pV(pic).

2,2'-Dipyridyl↗
PubMed1999

Mitochondrial DNA variation in cattle of south China: origin and introgression.

Ten restriction endonucleases were used to investigate the mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) of 11 native cattle breeds and one cultivated cattle breed in South China. Twenty-three restriction morphs were detected, which can be sorted into five haplotypes. A phylogenetic tree of the haplotypes was constructed by using the 'upgMa' method. Our study showed that haplotype I and II are identical to the zebu (Bos indicus) and taurine (Bos taurus) haplotypes, respectively. Zebu and taurine were the two major origins of cattle populations in South China, and the zebu probably had more influence on the native cattle population than taurine did. Haplotype III is identical to haplotype I of yak (Bos grunniens), which was only detected in the Diqing cattle breed. Haplotype IV was detected for the first time. This haplotype, found only in Dehong cattle, might be from an independent domestication event, probably from another Bos indicus population. Divergence of haplotypes I and IV occurred about 268,000-535,000 years ago, much earlier than the 10,000-year history of cattle husbandry. Our results also suggest a secondary introgession of mtDNA from yak to Diqing cattle.

Animal Husbandry↗
PubMed1994

Effects of muscle electrical activity on the transmission of developing neuromuscular junction.

Miniature endplate potentials (MEPPS) caused by the spontaneous release of ACh from the growth cone of cholinergic neurons, are recorded by the whole-cell patch-clamp technique on a large number of 1-day cultured myoballs which have contact neurites of co-cultured neurons. Both muscle cell and neuron are dissociated from the 1-day-old (about stage 20) Xenopus embryo. Frequency and/or amplitude of MEPPs can obviously increase after the repetitive high-level depolarization caused by the stimuli on muscle cells. No detectable changes of single ACh receptor channel property are observed by using the single-channel recording technique. These results suggest that the mechanism of the increase of MEPPs after electrical activity of postsynaptic muscle cells probably involve some alteration of presynaptic membrane.

Acetylcholine↗
PubMed1993

On two transposable elements from Bacillus stearothermophilus.

Two transposable elements, IS5376 and IS5377, were identified in the thermophile Bacillus stearothermophilus CU21 based upon the following criteria: (1) both were found to appear on different plasmids introduced into the same host CU21; (2) signals of homology were found between the genomic DNA of CU21 and each of them; (3) different numbers of Southern hybridization bands were found for the genomic DNA of different strains of B. stearothermophilus; and (4) characteristic inverted repeats at both ends and direct repeats of the target DNA adjacent to them were found for both IS5376 and IS5377. Two open reading frames (ORFs) were detected for IS5376 and one for IS5377. The putative coding products of the ORFs are homologous to those of known ISs from mesophiles and are considered to be transposases. The results of analyses of nucleotide sequence and the deduced amino acid sequence suggest that IS5376 is a member of the IS21 family and that IS5377 is a member of the IS4 family.

Amino Acid Sequence↗
PubMed1992

Molecular cloning and mapping of phenol degradation genes from Bacillus stearothermophilus FDTP-3 and their expression in Escherichia coli.

Two genes of the meta pathway of phenol degradation were cloned from a phenol-utilizing strain of Bacillus stearothermophilus and were mapped by subcloning and by use of a Tn5 insertion mutation. They code for phenol hydroxylase and catechol 2,3-dioxygenase, respectively. The gene encoding catechol 2,3-dioxygenase, which is more thermostable than catechol 2,3-dioxygenase encoded by the other gene, shares rather limited homology with that from Pseudomonas putida.

Catechol 2,3-Dioxygenase↗
PubMed1990

[Isolation and identification of chemical constituents of Astragalus root].

Ten constituents have been isolated from the alcoholic extract of Astragalus membranaceus var. monghlicum root. All of them were identified. Among them astraisoflavanin (3S-(-)-mucronulatol-7-O-D-glucopyranoside) is a new compound. Dimethyl 4,4'-dimethoxy-5,6,5',6'-dimethylenedioxybiphyenyl 1-2, 2'-dicarboxylate is a known synthetic compound, but it was first isolated from natural resource Astragalus root and identified by the authors.

Astragalus propinquus↗
PubMed1989

[Immunologic changes in serum CuZn-containing superoxide dismutase in patients with lung cancer].

Serum immunologic changed CuZn-containing superoxide dismutase (CuZn-SOD) level was determined in 45 patients with lung cancer and the results were compared with those in 22 normal persons and 19 cases with benign pulmonary diseases. The results were as follows: x +/- Sx of CuZn-SOD in the lung cancer group was 16.11 +/- 0.78 ng/ml, that in the benign pulmonary disease group was 9.51 +/- 0.61 ng/ml and that in the normal adults group was 7.22 +/- 0.79 ng/ml. The mean of the activity of serum immunologic changed CuZn-SOD in patients with lung cancer was significantly high than that in the other two groups. (P less than 0.001). If a serum immunologic changed CuZn-SOD level of 11.98 ng/ml and over is considered as Positive, the positive rate will be 80%, 11%, and 4.5% in the three groups respectively. In the light of the above findings, we suggest that determination of the activity of serum immunologic changed CuZn-SOD is helpful in the diagnosis of lung cancer.

Adenocarcinoma↗
PubMed1989

Treatment of 570 cases of oral squamous cell carcinoma.

This paper presents results of treatment in 570 cases with oral cancers. The overall 5-year survival rate was 64.5% and 92.8%, 84.9%, 50.2% and 16.4%, respectively for Stages I, II, III and IV. Five kinds of therapy have been used and discussed. The mortality rate of operation was 0.35%. The 5-year survival rate of 127 and 443 cases with and without cervical node metastases was 28.3% and 74.7% respectively. The 5-year survival rates of 81, 30 and 16 cases with involvement of 1, 2 and more than 3 nodes were 33.6%, 27.9% and 6.3% respectively. The 5-year survival rates were 35.5%, 14.4% and 0% when upper, middle and lower cervical nodes were respectively involved. Forty-six cases recurred and were operated on again, their 5-year survival rate was 23%.

Adult↗