ABSTRACT
Embryo retention in the fallopian tube is thought to lead to ectopic pregnancy, which is a significant cause of morbidity. This pathological condition does not occur in laboratory rodents. Moreover, incidences of tubal pregnancy after assisted reproduction (ART) are continuously increasing. What are the factors that need to be considered responsible for this condition? Ectopic pregnancies occur because of conflicting signals to the blastocyst from the two epithelia (uterine and fallopian). The signals consist of cytokines, chemokines and adhesion molecules that mediate both blastocyst adhesion to the uterine (and fallopian) epithelium and leukocyte adhesion to the vascular endothelium and, presumably, the fallopian epithelium. Chronic inflammation in the fallopian tube caused by infections or misplacements of the blastocyst (in the case of ART) can alter expression (upregulate) of the signals emanating from the fallopian tube and thereby can compete with the uterine (normal) site of implantation. That is, in ectopic pregnancy, a blastocyst may receive stronger signals from the tubal epithelia, migrate to the fallopian tube, and be implanted at that site.
Subject(s)
Embryo Implantation/physiology , Endometrium/metabolism , Fallopian Tubes/metabolism , Paracrine Communication/physiology , Pregnancy, Ectopic/physiopathology , Animals , Cell Adhesion Molecules/metabolism , Chemotaxis, Leukocyte , Female , Humans , Models, Biological , Pregnancy , Pregnancy, Ectopic/metabolismABSTRACT
The diazo coupling reaction of diazotized p-aminoacetophenone (DPAAP) with histidine and its metabolites form the basis of the differential pulse adsorption stripping voltammetry (DPASV) method for determination of histidine and its metabolites. The adsorption and electrochemical reaction mechanism of the coupling products were studied in detail by structure analysis, cyclic voltammetry, chronocoulometry, control potential electrolysis, electrocapillary curves, UV spectroscopy and the effect of temperature and surfactants. The adsorption of azo-histidine was found to obey Frumkin adsorption isotherm. The calculation results of the maximum surface excess (Gamma(m)=3.08x10(-11) mol cm(2)), diffusion coefficient (D=2.27x10(-6) cm(2) s(-1)), adsorption coefficient (beta=1.06x10(7)) and interactive factor (gamma=0.9900) showed that the azo-histidine conjugation molecules adsorbed on the mercury electrode surface were attracted each other and the electrode process was adsorption controlled.
