Structural characteristics of the corpus luteum during implantation in the rhesus monkey (Macaca mulatta)

Corpora lutea were obtained from ten pregnant rhesus monkeys during implantation, and the ultrastructure of granulosa and theca lutein cells was characterized. Specimens were individually staged with regard to the extent of implantation and the relationship to the rise in circulating progesterone and estrogen which is characteristic of early pregnancy. Structural changes characteristic of granulosa lutein cells occurring during implantation included: change in form of endoplasmic reticulum from predominantly agranular tubules to predominantly granular cisternae; reduction in size and number of lipid droplets; increase in area occupied by the Golgi and increase in length of the cisternae of the Golgi complex; development of numerous microvillus-lined intracellular spaces; increase in numbers of membrane-bound dense bodies including peroxisomelike bodies, multivesicular bodies within lobopodia, and other lysosomelike bodies; and alterations of mitochondrial cristae. These changes were suggestive of the production of a secretory protein, rapid utilization of existing steroid precursor reserves for the production of progesterone, and a reduction in capability for steroid precursor accumulation and processing by granulosa lutein cells. Structural changes characteristic of theca lutein cells occurring during implantation included an increase in size and number of lipid droplets, an increase in agranular endoplasmic reticulum, and an increase in area occupied by the Golgi complex. These changes were suggestive of an increased capability for steroid precursor accumulation and processing, perhaps for estrogen production, by the theca lutein cells.     

Testing for adaptive evolution of the female reproductive protein ZPC in mammals,birds and fishes reveals problems with the M7-M8 likelihood ratio test

Background  

Adaptive evolution appears to be a common feature of reproductive proteins across a very wide range of organisms. A promising way of addressing the evolutionary forces responsible for this general phenomenon is to test for adaptive evolution in the same gene but among groups of species, which differ in their reproductive biology. One can then test evolutionary hypotheses by asking whether the variation in adaptive evolution is consistent with the variation in reproductive biology. We have attempted to apply this approach to the study of a female reproductive protein, zona pellucida C (ZPC), which has been previously shown by the use of likelihood ratio tests (LRTs) to be under positive selection in mammals.     

Comparative aspects of trophoblast development and placentation

Based on the number of tissues separating maternal from fetal blood, placentas are classified as epitheliochorial, endotheliochorial or hemochorial. We review the occurrence of these placental types in the various orders of eutherian mammals within the framework of the four superorders identified by the techniques of molecular phylogenetics. The superorder Afrotheria diversified in ancient Africa and its living representatives include elephants, sea cows, hyraxes, aardvark, elephant shrews and tenrecs. Xenarthra, comprising armadillos, anteaters and sloths, diversified in South America. All placentas examined from members of these two oldest superorders are either endotheliochorial or hemochorial. The superorder Euarchontoglires includes two sister groups, Glires and Euarchonta. The former comprises rodents and lagomorphs, which typically have hemochorial placentas. The most primitive members of Euarchonta, the tree shrews, have endotheliochorial placentation. Flying lemurs and all higher primates have hemochorial placentas. However, the lemurs and lorises are exceptional among primates in having epitheliochorial placentation. Laurasiatheria, the last superorder to arise, includes several orders with epitheliochorial placentation. These comprise whales, camels, pigs, ruminants, horses and pangolins. In contrast, nearly all carnivores have endotheliochorial placentation, whilst bats have endotheliochorial or hemochorial placentas. Also included in Laurasiatheria are a number of insectivores that have many conserved morphological characters; none of these has epitheliochorial placentation. Consideration of placental type in relation to the findings of molecular phylogenetics suggests that the likely path of evolution in Afrotheria was from endotheliochorial to hemochorial placentation. This is also a likely scenario for Xenarthra and the bats. We argue that a definitive epitheliochorial placenta is a secondary specialization and that it evolved twice, once in the Laurasiatheria and once in the lemurs and lorises.     

Inducible nitric oxide synthase expression before and after eradication of Helicobacter pylori in different forms of gastritis

An increased expression of inducible nitric oxide synthase (iNOS) has been observed in the inflamed human gastric mucosa as well as in some tumors. This observation suggests a pathobiological role of elevated NO production. The purpose of this study was to compare the immunohistochemical iNOS expression in the different kinds of gastritis before and after the eradication of Helicobacter pylori. We performed iNOS and H. pylori immunohistochemical staining and counted iNOS positive cells. We detected elevated expression of iNOS around sites infected with H. pylori. iNOS expression in chemical gastritis was strongly elevated in mucosal glands. After treatment, we found a significant difference in iNOS expression in patients with classical H. pylori-induced antrum predominant gastritis and in patients with active autoimmune gastritis. In the special case of progressed gastritis with intestinal metaplasia we found persistence of intestinal metaplasia, and we could not find a significant difference in the number of positive iNOS cells before and after treatment. The persistence of IM as a possibly precancerous lesion is probably at least in the antrum a source of continuous iNOS induction even after H. pylori eradication.     

Dominant TNF-α+ Mycobacterium tuberculosis-specific CD4+ T cell responses discriminate between latent infection and active disease

Rapid diagnosis of active Mycobacterium tuberculosis (Mtb) infection remains a clinical and laboratory challenge. We have analyzed the cytokine profile (interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2)) of Mtb-specific T cells by polychromatic flow cytometry. We studied Mtb-specific CD4+ T cell responses in subjects with latent Mtb infection and active tuberculosis disease. The results showed substantial increase in the proportion of single-positive TNF-α Mtb-specific CD4+ T cells in subjects with active disease, and this parameter was the strongest predictor of diagnosis of active disease versus latent infection. We validated the use of this parameter in a cohort of 101 subjects with tuberculosis diagnosis unknown to the investigator. The sensitivity and specificity of the flow cytometry-based assay were 67% and 92%, respectively, the positive predictive value was 80% and the negative predictive value was 92.4%. Therefore, the proportion of single-positive TNF-α Mtb-specific CD4+ T cells is a new tool for the rapid diagnosis of active tuberculosis disease.     

Synthesis of dendritic polyglycerol anions and their efficiency toward L-selectin inhibition

A versatile route for the synthesis of highly functionalized, polyanionic macromolecules based on dendritic polyglycerol was applied by means of the Huisgen-Sharpless-Meldal 1,3-dipolar cycloaddition ("click-reaction") of polyglycerolazide precursors and alkyne-functionalized anions such as sulfonates, carboxylates, phosphonates, and bisphosphonates. In addition, the corresponding polyglycerol phosphate has been synthesized via direct hydroxyl interconversion of polyglycerol to the corresponding phosphate with a degree of functionalization >80% by analogy to the synthesis of previously reported polyglycerol sulfates (dPGS). On the basis of the finding that dPGS exhibits high affinity for L- and P-selectin, the potential of these novel polyanionic, multivalent macromolecules of varying anionic nature as L-selectin inhibitors has been evaluated in vitro by means of a competitive concentration dependent binding assay. Affinity of all polyanions toward L-selectin was demonstrated with distinct IC(50) values ranging from the low nanomolar to the high micromolar range. The efficiency of L-selectin inhibition increases in the order carboxylate < phosphate < phosphonate ≈ sulfonate < bisphosphonate < sulfate. Additional DLS and ζ-potential measurements of these polyanions were performed to correlate their binding affinity toward L-selectin with their anionic nature. However, a direct correlation of effective charge and particle size with the determined IC(50) values turned out to require further in-depth studies on the microstructure of the polyanions but clearly indicate an exceptional position of dPGS among the studied dendritic polyelectrolytes.