Energy Regulation in Inflammatory Sarcopenia by the Purinergic System.

The purinergic system has a dual role: the maintenance of energy balance and signaling within cells. Adenosine and adenosine triphosphate (ATP) are essential for maintaining these functions. Sarcopenia is characterized by alterations in the control of energy and signaling in favor of catabolic pathways. This review details the association between the purinergic system and muscle and adipose tissue homeostasis, discussing recent findings in the involvement of purinergic receptors in muscle wasting and advances in the use of the purinergic system as a novel therapeutic target in the management of sarcopenia.

Dipyridamole activates adenosine A2B receptor and AMPK/cAMP signaling and promotes myogenic differentiation of myoblastic C2C12 cells.

Introduction: Sarcopenia is defined as a loss of muscle mass and strength. ATP homeostasis is crucial during myogenesis. We determined how the purinergic system modulates myogenesis using dipyridamole (blocks adenosine taken up by the cells) and tenofovir (inhibits ATP release) in a myoblast cell line. Methods: C2C12 cells were differentiated in the presence/absence of tenofovir/dipyridamole, with/without the A2B selective inhibitor PSB-603. Extra-/intracellular nucleotides were examined via HPLC. The expression of muscle differentiation proteins (Pax7, Mif5, MyoD, MyoG, and MHC), PKA/CREB, adenosine receptors (A1, A2A, A2B, and A3), ATP-channel pannexin-1 and the P2X7 receptor was analyzed via WB and RT-PCR. cAMP and AMPK activation was measured. Results: Tenofovir increased intracellular ATP and reduced extracellular adenosine, decreasing Pax7 expression and increasing MHC expression prematurely. Dipyridamole increased intracellular AMP and extracellular adenosine, counteracting the premature myogenesis promoted by tenofovir. All adenosine receptors were expressed during differentiation with dipyridamole, increasing A2B expression. Tenofovir maintained inactive AMPK and decreased cAMP levels, as well as PKAα and pCREB expression, which were recovered with dipyridamole. Discussion: Adenosine and ATP act as mediators in muscle myogenesis. The blockade of ATP release by tenofovir promotes premature myogenesis, with dipyridamole counteracting the premature differentiation promoted by tenofovir via the adenosine A2B receptor and cAMP/AMPK pathways. Therefore, dipyridamole might be of interest as a therapeutic approach in sarcopenia.

[New anaerobic bacterial species in human infections]. / Nuevas bacterias anaerobias implicadas en enfermedades infecciosas humanas.

This review offers succinct, precise, and complete information based on the available data concerning new anaerobic bacterial species involved in infectious diseases in humans. All hitherto undescribed species, those not previously implicated in clinical conditions, those with confirmed implication in human disease that have not been characterized, and those that have undergone taxonomic changes are considered to be "new".

P- and E-selectin blockade can control bacterial translocation and modulate systemic inflammatory response.

Bacterial translocation is an important phenomenon in clinical medicine and leads to an increase in patient morbidity and mortality by multiple organ failure. The selectin family plays an important role in the pathogenesis of inflammation, causing an increase in leukocyte-endothelium interactions and inducing a greater leukocyte's migration. This study considered the effect of a sulfo derivative of Sialyl-Lewis(X), GM 1998-016, that will block the P- and E-selectins interaction with a ligand, the Sialyl-Lewis(X), valuing the modulation of the systemic inflammatory response and the induced translocation. Seventy-five Wistar male rats were injected intraperitoneally with Zymosan A and treated with different doses of GM 1998-016 according to study groups. Measurements of values of qualitative and quantitative microbiology, neutrophil infiltration (myeloperoxidase), oxygen free radicals (superoxide anion, superoxide dismutase, catalase, and gluthatione peroxidase), and cytokines (tumor necrosis factor-alpha and interleukin-1beta) were taken at different times after Zymosan administration. A significant decrease of bacterial translocation, both local (MLN) and systemic (p < .05), was observed, with a decrease in the neutrophil infiltration (p < .001), the oxygen free radicals production (p < .01) and the studied cytokines (p < .01). In conclusion, GM 1998-016 showed a protective effect in an in vivo experimental model of bacterial translocation, downregulating the inflammatory response and the leukocyte-endothelium interactions.

[Movies as a teaching resource for infectious diseases and clinical microbiology]. / El cine en la docencia de las enfermedades infecciosas y la microbiología clínica.

Since its inception, the cinema has constantly provided a reflection of infectious diseases because of their omnipresence in life and their importance to individuals and society. Few infectious diseases escape its eye, to the extent that the cinema constitutes an authentic treatise on these phenomena. The cinema is a very valuable educational resource, able to supplement classical teaching methods and to encourage critical thinking among students. The enormous flow of information, images, sounds, consequences, situations, and points of view that it provides should not be wasted and can be of great use, both in the spread of ideas and in training in infectious diseases and clinical microbiology.

Systemic inflammatory response induced by dacron graft and modulation by antimicrobial agents: experimental study.

BACKGROUND: The purpose of this work was to evaluate the effect that different antimicrobial agents and different forms of administering them would have over a systemic inflammatory response (SIR) induced by an intraperitoneally implanted collagen-coated Dacron graft. MATERIALS AND METHODS: Thirty-six male Wistar rats were randomly allocated into six groups of 6 animals each: (I) control, (II) "sham," (III) graft but no antibiotic, (IV) graft plus systemic cefazolin, (V) graft plus locally applied gentamicin, and (VI) graft soaked in rifampicin. After 72 h, mesenteric lymph nodes, liver, kidney, and the implanted graft were sent to the microbiology laboratory and cultured for aerobic and anaerobic organisms in order to evaluate bacterial translocation. Serum cytokines (IL-1beta and TNF-alpha), myeloperoxidase activity in liver and kidney, and superoxide anion and superoxide dismutase activities in liver were also determined to evaluate the level of SIR. RESULTS: Microbiologic and biochemical data indicated that intraperitoneal implantation of a collagen-coated Dacron graft induced a significant (P < 0.05) bacterial translocation and a high inflammatory response, both of which decreased significantly with antibiotic treatment regardless of the means of administration (P < 0.05). CONCLUSIONS: The present experimental model shows that the antibiotics used, in different means of administration, reduce bacterial translocation and behave as modulators of the SIR induced by an intraperitoneal collagen-coated Dacron graft.