Treatment of small intestinal bacterial overgrowth in systemic sclerosis: a systematic review.

Objectives: Almost all patients with SSc have gastrointestinal manifestations. Small intestinal bacterial overgrowth (SIBO) occurs in 30-60% of patients and leads to malnutrition and impaired quality of life. Recent systematic reviews have reported efficacy of treatments for SIBO, but these are not specific to patients with SSc. We conducted a systematic review of the evidence for all possible SIBO treatments in the SSc population. Methods: The following databases were searched: MEDLINE, EMBASE and the Cochrane Library, from database inception to 1 January 2017. All evidence for all possible SIBO treatments including antibiotics, prokinetics, probiotics and alternative treatments was included. Treatment outcomes included symptomatic relief or demonstrated SIBO eradication. Results: Of 5295 articles, five non-randomized studies were reviewed with a total of 78 SSc patients with SIBO. One trial assessed octreotide while the remaining four trials investigated the effectiveness of ciprofloxacin, rifaximin, norfloxacin and metronidazole, and the combination of amoxicillin, ciprofloxacin and metronidazole. Studies were generally of low quality and most were un-controlled. Conclusion: Data indicate that, for some SSc patients, antibiotics can eradicate SIBO. There is a paucity of data reporting the effectiveness of either prokinetics or probiotics in SSc.

Pregnancy Hyperglycemia in Prolactin Receptor Mutant, but Not Prolactin Mutant, Mice and Feeding-Responsive Regulation of Placental Lactogen Genes Implies Placental Control of Maternal Glucose Homeostasis.

Pregnancy is often viewed as a conflict between the fetus and mother over metabolic resources. Insulin resistance occurs in mothers during pregnancy but does not normally lead to diabetes because of an increase in the number of the mother's pancreatic beta cells. In mice, this increase is dependent on prolactin (Prl) receptor signaling but the source of the ligand has been unclear. Pituitary-derived Prl is produced during the first half of pregnancy in mice but the placenta produces Prl-like hormones from implantation to term. Twenty-two separate mouse genes encode the placenta Prl-related hormones, making it challenging to assess their roles in knockout models. However, because at least four of them are thought to signal through the Prl receptor, we analyzed Prlr mutant mice and compared their phenotypes with those of Prl mutants. We found that whereas Prlr mutants develop hyperglycemia during gestation, Prl mutants do not. Serum metabolome analysis showed that Prlr mutants showed other changes consistent with diabetes. Despite the metabolic changes, fetal growth was normal in Prlr mutants. Of the four placenta-specific, Prl-related hormones that have been shown to interact with the Prlr, their gene expression localizes to different endocrine cell types. The Prl3d1 gene is expressed by trophoblast giant cells both in the labyrinth layer, sitting on the arterial side where maternal blood is highest in oxygen and nutrients, and in the junctional zone as maternal blood leaves the placenta. Expression increases during the night, though the increase in the labyrinth is circadian whereas it occurs only after feeding in the junctional zone. These data suggest that the placenta has a sophisticated endocrine system that regulates maternal glucose metabolism during pregnancy.

The evolution, regulation, and function of placenta-specific genes.

A number of placenta-specific genes (e.g., Tpbp, Plac1, Syncytin, and retrotransposon-associated genes such as Peg10, Rtl1, Endothelin B receptor, Insl4, Leptin, Midline1, and Pleiotrophin), enhancer elements (e.g., glycoprotein hormone alpha-subunit) and gene isoforms (e.g., 3betaHSD, Cyp19), as well as placenta-specific members of gene families (e.g., Gcm1, Mash2, Rhox, Esx1, Cathepsin, PAG, TKDP, Psg, Siglec) have been identified. This review summarizes their evolution, regulation, and biochemical functions and discusses their significance for placental development and function. Strikingly, the number of unique, truly placenta-specific genes that have been discovered to date is very small. The vast majority of placenta-specific gene products have resulted from one of three mechanisms: evolution of placenta-specific promoters, evolution of large gene families with several placenta-specific members, or adoption of functions associated with endogenous retroviruses and retroelements. Interestingly, nearly all the examples of placenta-specific genes that have been discovered to date are not present in all placental mammals.