Citrulina plasmática como marcador de pérdida de masa enterocitaria en la enfermedad celíaca en la infancia

Introduction: Plasma citrulline is not incorporated in endogenous or exogenous proteins so it is a theoretical marker of villous atrophy. Our aim was to correlate plasma citrulline levels with severity of villous atrophy inceliac patients. Methods: Observational case-control study longitudinal in children 16 month-old to 14 year-old: 48 with untreated celiac disease, 9 celiac children under gluten free diet and 35 non-celiac healthy children. Plasma amino acids concentration is determined, expressed in μmol/L, and so are other clinical and analytical data. Results: No statistically significative difference found in the referring to BMI, age or renal function. Small increase in fecal fat in celiac children. Citrulline, arginine and glutamine are significantly lower in cases (17.7 μmol/l, 38.7 μmol/l, 479.6 μmol/l respectively) than in controls (28.9 μmol/l, 56.2 μmol/l, 563.7 μmol/l). Citrulline levels are significantly lower in the severe degrees of atrophy than in mild ones (13.8 μmol/l vs. 19.7 μmol/l, p < 0.05), not happening so with rest of amminoacids. Summary: Postabsortive mean of plasma citrulline is a good marker of reduction in enterocyte mass in celiac patients with villous atrophy; secondary reduction in plasma arginine too. Just a small histological alteration in intestinal biopsy is enough to differentiate citrulline in cases and controls and besides it can be seen that high levels of atrophy present with lower plasma citrulline.

Structural characterization and distribution of zebrafish germ plasm during interphase and mitosis

In zebrafish, germ cells are responsible for transmitting the genetic information from one generation to the next. During the first cleavages of zebrafish embryonic development, a specialized part of the cytoplasm known as germ plasm, is responsible of committing four blastomeres to become the progenitors of all germ cells in the forming embryo. Much is known about how the germ plasm is spatially distributed in early stages of primordial germ cell development, a process described to be dependant on microtubules and actin. However, little is known about how the material is inherited after it reorganizes into a perinuclear location, or how is the symmetrical distribution regulated in order to ensure proper inheritance of the material by both daughter cells. It is also not clear whether there is a controlled mechanism that regulates the number of granules inherited by the daughter cells, or whether it is a random process. We describe the distribution of germ plasm material from 4hpf to 24hpf in zebrafish primordial germ cells using Vasa protein as marker. Vasa positive material appears to be conglomerate into 3 to 4 big spherical structures at 4hpf. While development progresses, these big structures become smaller perinuclear granules that reach a total number of approximately 30 at 24hpf. We investigated how this transformation occurs and how the minus-end microtubule dependent motor protein Dynein plays a role in this process. Additionally, we describe specific colocalization of microtubules and perinuclear granules during interphase and more interestingly, during all different stages of cell division. We show that distribution of granules follow what seems to be a regulated distribution: during cells division, daughter cells inherit an equal number of granules. We propose that due to the permanent colocalization of microtubular structures with germinal granules during interphase and cell division, a coordinated mechanism between these structures may ensure proper distribution of the material among daughter cells. Furthermore, we show that exposure to the microtubule-depolymerizing drug nocodazole leads to disassembly of the germ cell nuclear lamin matrix, chromatin condensation, and fusion of granules to a big conglomerate, revealing dependence of granular distribution on microtubules and proper nuclear structure.