In pigs, uterine exposure to the constituents of semen is known to increase litter size but the underlying physiological mechanisms remain undefined. Studies in rodents and humans implicate immune modulating moieties in seminal plasma as likely candidates, acting through enhancing the receptivity of the female tract. In this study, the acute and longer term effects of seminal plasma on cytokine expression and leukocyte abundance in the pig endometrium during early pregnancy have been characterised. The reproductive tracts of gonadotrophin-primed pre-pubertal gilts treated with intrauterine infusions of either pooled seminal plasma or phosphate-buffered saline (PBS) were retrieved at 34 h, or on day 5 and day 9 after treatment. Seminal plasma elicited an endometrial inflammatory infiltrate comprised of predominantly macrophages and major histocompatibility complex class II+-activated macrophages and dendritic cells. The abundance of these cells was greatest at the pre-ovulatory (34 h) time-point and their increase relative to PBS-treated tissues was maintained until day 9 after seminal plasma treatment. Seminal plasma induced the expression of the cytokines, granulocyte macrophage colony-stimulating factor, interleukin-6 and monocyte chemoattractant protein-1, and the eicosanoid-synthesising enzyme cyclo-oxygenase-2. Expression was maximal 34 h after treatment but altered expression patterns as a consequence of seminal plasma induction persisted through early pregnancy. These changes were accompanied by altered dynamics in pre-implantation embryo development with an increase in the number of embryos and in their viability after seminal plasma treatment. Together, these findings implicate factors in seminal plasma in programming the trajectory of uterine cytokine expression and leukocyte trafficking during early pregnancy and in regulating pre-implantation embryo development in the pig.
Despite safe and effective childhood immunizations, decreased acceptance of vaccines has become an emerging global problem. The WHO SAGE Working Group on Vaccine Hesitancy developed a common diagnostic tool, the Vaccine Hesitancy Scale (VHS), to identify and compare hesitancy in different global settings. We field tested the VHS in rural and urban Guatemala. We analyzed data from the enrollment visit of a study conducted at four public health clinics in Guatemala. Infants ages 6 weeks-6 months presenting for their first wellness visit were enrolled March-November 2016. Parents completed a demographic survey that included the 10 dichotomous and 10 Likert scale VHS questions. Chi-square or Fisher's exact for categorical and ANOVA test for continuous variables were used to assess significance levels in survey differences. We conducted a factor analysis to assess the Likert scale questions. Of 1088 families screened, 871 were eligible and 720 (82.7%) participated. No parent had ever refused a vaccination, and only eight parents (1.1%) had been reluctant or hesitated to get a vaccination for their children. However, only 40.8% (n = 294) of parents said that they think most parents like them have their children vaccinated with all the recommended vaccines. Factor analysis identified two underlying constructs that had eigenvalues of 1.0 or greater and a substantive lack of variability in response across the Likert scale. There were consistent differences between how study clinics responded to the ordinal scaling. Our results suggest problems with interpretation of the VHS, especially in the presence of vaccine shortages and using a Likert scale that does not resonate across diverse cultural settings. Our factor analysis suggests that the Likert scale items are more one-dimensional and do not represent the multiple constructs of vaccine hesitancy. We suggest more work is needed to refine this survey for improved reliability and validity. Clinical Trial Registry: NCT02567006.
1 October 2019 in American Journal of Preventive Medicine
Traditionally, research in the field of trace element biology and human and animal health has largely depended on epidemiological methods to demonstrate involvement in biological processes. These studies were typically followed by trace element supplementation trials or attempts at identification of the biochemical pathways involved. With the discovery of biological molecules that contain the trace elements such as matrix metalloproteinases (MMPs) containing Zinc (Zn); cytochrome P450 enzymes containing iron (Fe); and selenoproteins containing selenium (Se), much of the current research focuses on these molecules and hence only indirectly on trace elements themselves. This review focuses largely on two synchrotron-based X-ray techniques; X-ray absorption spectroscopy (XAS) and X-ray fluorescence (XRF) imaging that can be used to identify the in situ speciation and distribution of trace elements in tissues, using our recent studies of bovine ovaries where the distribution of Fe, Se, Zn and bromine (Br) were determined. It also discusses the value of other techniques, such as inductively coupled plasma mass spectrometry, used to garner information about the concentrations and elemental state of the trace elements. These applications to measure trace elemental distributions in bovine ovaries at high resolutions provides new insights into possible roles for trace elements in the ovary.
1 February 2018 in American Journal of Preventive Medicine