Association between obesity-related plasma hemodilution and the concentration of prostate specific antigen / 南方医科大学学报

<p><b>OBJECTIVE</b>To determine the effect of obesity on prostate specific antigen (PSA) in men with benign prostatic hyperplasia (BPH) and develop a PSA-related parameter that can eliminate the effect of obesity.</p><p><b>METHODS</b>We reviewed the clinical data of 706 patients with BPH. Two PSA-related parameters, namely PSA mass (total circulating PSA protein) and PSA mass ratio (total circulation PSA protein per prostate volume), were calculated for all the patients and the association of BMI with PSA, PSA mass, and PSA mass ratio was assessed.</p><p><b>RESULTS</b>A higher BMI was significantly associated with a greater plasma volume and prostate volume (P<0.05). Linear regression analysis revealed a greater adjusted R2 of BMI versus plasma volume than of BMI PSA (0.569 vs 0.027). PSA was positively associated with the prostate volume and negatively with BMI and plasma volume (P<0.05). PSA mass was positively associated with prostate volume (P<0.05) but was not associated with BMI or plasma volume (P>0.05). PSA mass ratio was not associated with prostate volume (P>0.05) but negatively associated with BMI and plasma volume. Plasma volume and prostate volume, PSA, and PSA mass ratio (P<0.05), but not PSA mass (P>0.05), differed significantly among normal-weight, overweight, and obese patients.</p><p><b>CONCLUSION</b>A higher BMI is associated with a greater plasma volume in BPH patients. In obese patients with BPH, a lower PSA concentration may result from hemodilution caused by a greater plasma volume, and PSA mass can eliminate the effect of obesity on PSA.</p>

Prokaryotic expression, purification and antigenicity identification of mouse VEGFR2 extracellular 1-4 IgG-like domains / 南方医科大学学报

<p><b>OBJECTIVE</b>To obtain 1-4 IgG-like domains of mouse vascular endothelial growth factor receptor 2 (VEGFR2) fusion protein (mVEGFR2D1-4/GST) and identify its antiginicity and biological activity.</p><p><b>METHODS</b>The gene of mVEGFR2D1-4 was amplified by RT-PCR from 14-days embryos of Balb/c mice. The PCR product was cloned into pET-42a prokaryotic expression vector to construct the recombinant plasmid pET-42a-mVEGFR2D1-4, which was transformed into E. coli BL21 (DE3) strain for mVEGFR2D1-4/GST expression. The fusion protein was identified by SDS-PAGE and Western blotting, and the antigenicity of the protein purified by affinity chromatography was characterized by ELISA. The VEGF blocking effect of the purified protein in human umbilical vein endothelial cells (HUVECs) were evaluated in in vitro cell cultures.</p><p><b>RESULTS</b>The mVEGFR2D1-4 gene was obtained, which had an identical sequence to that retrieved in GenBank. The prokaryotic expression vector for mVEGFR2D1-4 was successfully constructed as confirmed by enzyme digestion and DNA sequencing. Both Western blotting and ELISA demonstrated the antigenicity of the purified mVEGFR2D1-4 fusion protein, which obviously blocked the effect of VEGF in promoting HUVEC proliferation in vitro.</p><p><b>CONCLUSION</b>The mVEGFR2D1-4/GST fusion protein obtained shows a strong antigenicity and biological activity to facilitate further study of active anti-tumor immunotherapy targeting VEGFR2.</p>