Divergent calcium signaling in RBCs from Tropidurus torquatus (Squamata – Tropiduridae) strengthen classification in lizard evolution

Abstract Background We have previously reported that a Teiid lizard red blood cells (RBCs) such as Ameiva ameiva and Tupinambis merianae controls intracellular calcium levels by displaying multiple mechanisms. In these cells, calcium stores could be discharged not only by: thapsigargin, but also by the Na+/H+ ionophore monensin, K+/H+ ionophore nigericin and the H+ pump inhibitor bafilomycin as well as ionomycin. Moreover, these lizards possess a P2Y-type purinoceptors that mobilize Ca2+ from intracellular stores upon ATP addition. Results Here we report, that RBCs from the tropidurid lizard Tropidurus torquatus store Ca2+ in endoplasmic reticulum (ER) pool but unlike in the referred Teiidae, these cells do not store calcium in monensin-nigericin sensitive pools. Moreover, mitochondria from T. torquatus RBCs accumulate Ca2+. Addition of ATP to a calcium-free medium does not increase the [Ca2+]c levels, however in a calcium medium we observe an increase in cytosolic calcium. This is an indication that purinergic receptors in these cells are P2X-like. Conclusion T. torquatus RBCs present different mechanisms from Teiid lizard red blood cells (RBCs), for controlling its intracellular calcium levels. At T. torquatus the ion is only stored at endoplasmic reticulum and mitochondria. Moreover activation of purinergic receptor, P2X type, was able to induce an influx of calcium from extracelullar medium. These studies contribute to the understanding of the evolution of calcium homeostasis and signaling in nucleated RBCs.

Papillary atrophy of the tongue and nutritional status of hospitalized alcoholics

BACKGROUND: Atrophy of the papillae, mucosa, and dorsum of the tongue are considered classical signs of nutritional deficiencies. OBJECTIVE: To assess the nutritional status of hospitalized alcoholics with or without papillary atrophy of the tongue. METHODS: This study was performed with 21 hospitalized alcoholics divided into Atrophic Glossitis Group (n=13) and Normal Tongue Group (n=8). Healthy, non-alcoholic volunteers composed the Control Group (n=8). Anthropometry and bioelectric impedance were performed, and serum vitamins A, E, and B12 were determined. RESULTS: There were no statistical differences in relation to age (46.7±8.7 vs. 46.8±15.8 years) or gender (92.3% vs. 87.5% male), respectively. Control Group volunteers were also paired in relation to age (47.5±3.1 years) and male predominance (62.5%). In relation to hospitalized alcoholics without atrophic lesions of the tongue and Control Group, patients with papillary atrophy showed lower BMI (18.6 ± 2,5 vs 23.8 ± 3.5 vs 26.7 ± 3,6 kg/m² ) and body fat content 7.6 ± 3.5 vs 13.3 ± 6.5 vs 19.5 ± 4,9 kg). When compared with the Control Group, alcoholic patients with or without papillary atrophy of the tongue showed lower values of red blood cells (10.8 ± 2.2 vs 11.8 ± 2.2 vs 14.5 ± 1,6g/dL) and albumin (3.6 ± 0.9 vs 3.6 ± 0.8 vs 4.4 ± 0.2g/dL). The seric levels of vitamins A, E, and B12 were similar amongst the groups. CONCLUSION: Hospitalized alcoholics with papillary atrophy of the tongue had lower BMI and fat body stores than controls, without associated hypovitaminosis.

Intravital microscopy technique to study parasite dynamics in the labyrinth layer of the mouse placenta

Intravital imaging techniques are the best approach to investigate in situ cellular behavior under physiological conditions. Many techniques have emerged during these last few years for this purpose. We recently described an intravital imaging technique that allows for the observation of placenta physiological responses at the labyrinth layer of this tissue. This technique will be very useful to study many placental opportunistic infections and in this article we reinforce its usefulness by analyzing placental physiological entrapment of beads and parasites. In particular, our results show that small beads (1.0 μm) or Plasmodium chabaudi-GFP-infected-Red Blood Cells (Pc-GFP-iRBCs) cannot get trapped inside small or large blood vessels of popliteal lymph nodes (PLNs). Inside the placenta, clusters of beads could only be found inside the maternal blood vessels. However, Pc-GFP-iRBCs were found inside and outside the maternal blood vessels. We observed that trophoblasts can ingest infected-Red Blood Cells (iRBCs) in vitro and immunofluorescence of placenta revealed Pc-GFP-iRBCs inside and outside the maternal blood vessels. Taken together, we conclude that fast deposition of particles inside blood vessels seems to be an intrinsic characteristic of placenta blood flow, but iRBCs could be internalized by trophoblast cells. Thus these results represent one of the many possible uses of our intravital imaging technique to address important questions inside the parasitological field.