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Biomedical subjects

Z Mao

Publications and source records attributed to Z Mao.

61 records · Page 4Linked to original sources
PubMed1996

The cytochrome P450 2D6 (CYP2D6) enzyme polymorphism: screening costs and influence on clinical outcomes in psychiatry.

OBJECTIVES: This study examined factors that affect cost, reliability, and the value of determining the cytochrome P450 2D6 (CYP2D6) polymorphism in clinical practice. STUDY DESIGN: The method of deoxyribonucleic acid isolation, sample preparation, oligonucleotide primers, and polymerase chain reaction procedures were scrutinized for their effect on CYP2D6 genotyping efforts. The determination of the CYP2D6 A, B, D, E, and T alleles was used to identify the deficiency in CYP2D6 expression in 161 individuals phenotyped for CYP2D6 activity with dextromethorphan. The CYP2D6 genotype was assessed in 74 outpatients who had received diagnoses of depression. Eighteen of these patients were screened because of an adverse response to a tricyclic or antidepressant known or suspected to be a CYP2D6 substrate. RESULTS: The CYP2D6 A, B, C, D, E, and T alleles could be detected in 13 hours at a cost of $84 per sample by judicious selection of conditions and procedures. The genotype provided an accurate predictor of CYP2D6 expression in all 134 subjects who expressed the enzyme and in all 27 unrelated individuals phenotyped as deficient in CYP2D6 activity. In the patient group that experienced adverse effects, 44% of all CYP2D6 gene copies contained the A, B, D, E, or T allele(s) associated with inactive CYP2D6 expression. This was more than twice the rate for the occurrence of mutant alleles in the other 56 psychiatric patients (21%) and in 80 random subjects from the general population (20%; p < 0.05). CONCLUSIONS: Screening psychiatric patients for CYP2D6 expression may distinguish metabolic-based therapeutic problems from drug sensitivity caused by other mechanisms.

Antidepressive Agents, Tricyclic↗
PubMed1996

[Distribution and quantification of oxidative low density lipoprotein in the development of atherosclerotic lesions of human aorta].

A total of 35 human aorta specimens obtained within 12 hours postmortem were collected. The distribution pattern and quantity of LDL and ox-LDL in atherosclerotic lesions of varying severity and the relationship with aorta cells were studied by immunohistochemical techniques and computorized image processing. The results showed that the staining pattern with anti-ox-LDL and antibodies to apoB was similar; in fatty steaks, the staining for ox-LDL was predominantly cell-associated in macrophages derived foam cells, in the late lesions, its pattern shifted to smooth muscle cells and extra-cellular matrix staining, there was also more apoB in fibrofatty plaques and atheromatous plaques than in fatty streaks, but no significant difference was found between the two stages of plaques. The quantity of Cu(2+)-ox-LDL significantly increased with the development of AS. There was more LDL than ox-LDL in fatty streaks, but in the late plaques, there was significantly more ox-LDL than LDL.

Aorta↗
PubMed1993

In vitro oocyte maturation in the zebra fish, Brachydanio rerio, and the fertilization and development of the mature egg.

The in vitro maturation process of zebra fish oocytes was investigated. When incubated with medium EM-199 containing 0.5 microgram/ml of 17 alpha-hydroxyprogesterone in an incubator with 80% O, 25 degrees C, the germinal vesicles of the oocytes in stage IV migrated from middle between the center and the periphery to the periphery in 40 min, and the oocytes went into stage V 30 min later, undergoing germinal vesicle breakdown (GVBD) with a GVBD% of 59%. Two hours were needed for such oocytes to complete their final maturation. The mature eggs cannot come off the follicle layer surrounding them naturally (ovulation). By removing the follicle and adding active sperm for insemination, we can cause the mature eggs to become fertilized. The chorion elevated and blastoderm formed on the animal pole. The cleavage and development of the fertilized eggs followed are the same as naturally matured fertilized eggs. Using blastula as the criterion for a successful fertilization of the in vitro maturated egg, the fertilization rate is 78%. This is the first report on the successful oocyte final maturation in vitro in zebra fish. The establishment of an oocyte in vitro maturation technique has given grounds for the further investigation on the transfer of foreign genes in the germinal vesicles of the oocytes.

17-alpha-Hydroxyprogesterone↗
PubMed1990

Young's modulus, bending strength, and tissue physical properties of human compact bone.

The Young's modulus, bending strength, apparent density, and ash content of 155 human compact bone bending specimens were determined. Both Young's modulus (E) and bending strength (S) were strongly correlated to tissue dry apparent density (rho a). Based upon the correlation coefficient (R) and the percent deviation of the data from the regression curve (% dev.), these correlations were best described by power law relationships: E infinity rho a 1.54 (R2 = 0.79, % dev. = 2.4) and S infinity rho a 2.18 (R2 = 0.80, % dev. = 6.4). Bending strength was related to Young's modulus raised to the 1.26 power, implying a nonlinear relationship for these variables. We found a weak correlation between ash content and the mechanical behavior of the compact bone specimens, particularly Young's modulus, but could not statistically justify formulation of a more complex multivariate power model incorporating both density and ash content. Regional variations in strength and stiffness along the femoral shaft and within the cortex were also noted and were attributed primarily to differences in apparent density. The relationships formulated for the mechanical behavior of human compact bone are discussed in terms of the results of previous investigations of the mechanical behavior of nonhuman compact bone and human cancellous bone.

Aged↗