Construction and Analysis of Three-dimensional Graphic Model of Single-chain Fv Derived from an Anti-human Placental Acidic Isoferritin Monoclonal Antibody by Computer

Summary: A three-dimensional (3D) graphic model of a single-chain Fv (scFv) which was derived from an anti-human placental acidic isoferritin (PAF) monoclonal antibody (MAb) was construct- ed by a homologous protein-predicting computer algorithm on Silicon graphic computer station. The structure, surface static electricity and hydrophobicity of scFv were investigated. Computer graphic modelling indicated that all regions of scFv including the linker, variable regions of the heavy (VH) and light (VL) chains were suitable. The VH region and the VL region were involved in composing the 'hydrophobic pocket'. The linker was drifted away VH and VL regions. The complementarity determining regions (CDRs) of VH and VL regions surrounded the 'hydrophobic pocket'. This study provides a theory basis for improving antibody affinity, investigating antibody structure and analyzing the functions of VH and VL regions in antibody activity.

Placental Isoferritin Action in Pathogenesis of Pre-eclampsia and/or Intrauterine Growth Retardation and Its Earlier Predictive Value

In order to investigate the role of placental isoferritin (PLF) in pathogenesis of pre-eclampsia and/or intrauterine growth retardation (IUGR) and its earlier predictive value, a prospective double-blinded study was performed. In 120 initial normal pregnant women at earlier third trimester (from 24 to 34 weeks), plasma placental isoferritin and nitric oxide (NO) metabolites (nitrite/nitrate) (NO 2 -/NO 3 -) were examined by using ELISA and Criess assay respectively. The outcome of pregnancies and birth weight of their infants were followed up. The receiver operating characteristic curves (ROC) and predictive values of PLF predicting the outcome of pregnancy with IUGR, pre-eclampsia were analyzed. Results showed that in 120 initial normal pregnant women, IUGR occurred in 15 pregnant women (IUGR group) and pre-eclampsia in 19 (pre-eclampsia group), and the remaining 86 had normal pregnancy (normal group). The levels of plasma placental isoferritin were significantly decreased in IUGR group (260.01±58.95) μg/ml and pre-eclampsia group (285.31±53.73) μg/ml as compared with those in normal group (775.62±89.32) μg/ml at earlier third trimester (both P<0.01). The levels of plasma NO were significantly increased in IUGR group (61.57±46.22) μmol/L and pre-eclampsia group (58.37±30.52) μmol/L as compared with those in the normal group (35.29±24.46) μmol/L (both P<0.01). There was no significant difference in plasma placental isoferritin and NO levels between IUGR group and pre-eclampsic group (both P>0 05). The plasma placental isoferritin was negatively correlated with NO levels (r=0.329,P<0 01). The areas under ROC of PLF predicting IUGR and pre-eclampsia were 0.977 and 0.905 respectively. At the cut point of 400 μg/ml PLF level, the sensitivity, specificity, positive predictive value, negative predictive value and Kappa index of PLF levels predicting the outcome of pregnancy with pre-eclampsia were 100 %, 85.15 %, 55.88 %, 100 % and 0.645 respectively. At the cut point of 390 μg/ml PLF level, the sensitivity, specificity, positive predictive value, negative predictive value and Kappa index of PLF levels predicting the outcome of pregnancy with IUGR were 100 %, 81.9 %, 44.12 %, 100 % and 0.663 respectively. It was concluded that the decrease of plasma placental isoferritin levels at earlier third trimester was associated with IUGR and/or pre-eclampsia, and the endothelial cell damage may be one of its mechanisms. The plasma PLF level can be used as an earlier predictor for screening of IUGR and/or pre-eclampsia.

Effects of Placental Isoferritin on the Mouse Embryo Development in vitro

To investigate the effect of placental isoferritin （PLF） on mouse embryo development in vitro, mice 2-cell embryos were co-cultured with human first trimester decidual cells at different concentrations of PLF in vitro. The following changes of the above system were observed under an invert microscope and the number of embryos were recorded and the embryos were classified. The results showed there was no significant difference in the percentage of embryos development to 4-cell 8-cell and morula （P〉0.05）. PLF at the doses of 10 and 100 U/mL significantly enhanced more embryos development to the blastocyst and hatching blastocyst （P〈0.05）. PLF at the dose of 1000 U/mL depressed more embryos development from 2-cell to hatching blastocyst, meanwhile such phenomena as cell degeneration and irregular cleavage were observed in part of embryos, but there was no significant difference in statistics （P〉0.05）. It was concluded that PLF at the concentration of 10-- 100 U/mL had no significant effects on the early development of mice embryos, however, PLF could promote the growth, differentiation, and hatching of preimplantion blastocysts.