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Z Y Dai

Publications and source records attributed to Z Y Dai.

At least 19 recordsLinked to original sources
PubMed2000

[Determination of tetrandrine in human plasma by high-performance liquid chromatography].

The paper reports the determination of tetrandrine by high performance liquid chromatography (HPLC). A C18 column was used and the mobile phase was methanol-water(80:20) containing 0.03% triethylamine, detective wave was at 282 nm, the internal standard was diazepam, the sample was extracted with ether. The linear range was from 0.289 microgram.ml-1 to 4.618 micrograms.ml-1, the average recovery rate was 95.8%. The coefficients of variation of within-day and day-to-day were less than 5%. This method is simple, rapid and accurate. It can be used in biomedical sample analysis of tetrandrine.

Alkaloids↗
PubMed2000

[Fusion expression of cecropin X including the cleavage of FXa in Escherichia coli].

PCR method was used to introduce the code sequence of Factor Xa cleavage site to the 5' end of cecropin CMIV mutant gene X, then the gene was cloned into the expression vector pGEX-KG, and was highly expressed in E. coli BL21 by IPTG induction. The fusion protein was purified by affinity-chromatography and was cleaved by Factor Xa. Cecropin X with antibacterial activity was obtained after purified by ion-exchange chromatography.

Antimicrobial Cationic Peptides↗
PubMed2000

[Studies on quantitative chromatographic retention-structure relationships].

Using quantum and molecular mechanics methods, 48 structural descriptors of alkylbenzene compounds such as atomic partial charge, dipole moment, molecular area, molecular volume etc. were calculated. GFA regression methods were applied to build a quantitative chromatographic retention-structure relationships equation. The equation have good fitness and strong predictivity. Principle structural factors that effect chromatographic retention of alkylbenzenes were discussed.

Alkylation↗
PubMed1990

[Oligohydramnios].

Explore the source record for details and available documents.

Amniotic Fluid↗
PubMed1989

The length of a junction between the B and Z conformations in DNA is three base pairs or less.

Recently it has been suggested that double-helical complexes formed between the DNA sequences (CG)n(A)m and their conjugates, (T)m(CG)n, would be candidates for the formation of a B-Z junction in aqueous solution at high salt concentrations [Peticolas et al. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 2579-2583]. The junction was predicted to occur between a B-type helix in the d(A)m.d(T)m section and a Z-type helix in the self-complementary (CG)n.(CG)n sequence. In this paper we report Raman experiments on the deoxyoligonucleotides d(CGCGCGCGCGCGAAAAA) and d(CGCGCGAAAAA) and their complements. It is found the latter compound cannot be induced into the Z form in saturated salt solution but that the former sequence goes into a B-Z junction at 5.5 M salt. From a comparison of the relative intensity of the Raman conformational marker bands for B and Z DNA for both the A-T and C-G base pairs, it is shown that in 5.5 M NaCl solution none of the A-T base pairs are in the Z form, but nine of the C-G base pairs are in the Z form. The remaining three C-G base pairs are either in the junction or in the B form. Thus, the junction is formed from three or less C-G base pairs. If the solution is made 95 microM with NiCl2, then the entire duplex goes into the Z form and the Raman bands of the adenine are completely changed into those of the Z form.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Composition↗
PubMed1989

Points that merit consideration in the diagnosis of retinoblastoma.

According to the clinical appearances and the characteristics of the onset of 86 Rb cases, some points in the diagnosis merit consideration: 1) Since the average symptomatic age was 21.75 months and the mean diagnostic age was 24.32 months, children under 3 years with leukocoria should be carefully examined, while adult Rb should not be neglected. 2) The primary symptom of Rb is mostly leukocoria, but Rb eyes without any symptoms or leukocoria (26 out of 105 eyes in our groups) might also be encountered. 3) 4 out of the 86 cases were retinocytoma which is supposed to be a type of Rb degeneration or benign Rb. 4) Attention should be paid to abnormalities and second primary tumors in Rb patients. 5) The pedigree investigations, twin method and laboratory studies in Rb such as chromosome analysis, EsD, LDH measurement and RFLP technique are useful in the prenatal diagnosis, early diagnosis and the diagnosis of the carriers.

Eye Neoplasms↗
PubMed1989

Ocular survey of deaf-mute children.

Through routine ocular examination of 279 Deaf-mute students in Lie De School in Guangzhou in 1988 by visual chart, Yu Zi Ping Pseudoisochromatic plate, portable slit lamp and direct ophthalmoscope, 100 persons (35.8%) were found to have ocular defects in one or both eyes. The incidence of ocular defects was higher than that of the normal populations. Among the ocular abnormalities, fundus defects occupied 28.6%, error of refraction, 17.9%. 17.9% of the eyes had the vision lower than 1.0 and the error of refraction was the main cause. Cases of hereditary syndromes were found: Usher syndrome, 2 cases; Goldenhar syndromes, 2 cases (brother and sister); Waardenburg syndrome, 1 case; von Recklinghausen's syndrome, 1 case. In comparing with the other articles, the ocular defect, visual disturbance, error of refraction, way of examination as well as types and characteristics of some syndromes were briefly discussed. The importance of special examinations for diagnosis, early correction of refractive error, avoidance of consanguineal marriage among deaf-mutes were emphasized.

Adolescent↗
PubMed1989

Lymphocyte chromosome survey in 80 patients with retinoblastoma.

Cytogenetic analysis of eight cases of retinoblastoma patients was carried out to determine the occurrence of chromosome aberrations and to identify consistently associated clinical abnormalities. Among the 80 cases, 55 cases were unilateral, 25 cases were bilateral, seventy patients had a positive family history of Rb in 10 families. Normal chromosomes were found in 70 patients. Ten patients showed abnormal karyotypes: two cases of 13q deletion, one case of mosaicism of 13q deletion, one case of translocation between chromosomes 13 and 15 with the interstitial deletion of 13q, one case of 47, xxy, three cases of pericentric inversion of heteromorphic region of chromosome 9, two cases of pericentric inversion of chromosome Y. The patient who had the translocation between 13 and 5 with 13q deletion was found to have the characteristic midfacial appearance associated with 13q-deletion syndrome.

Adolescent↗