34 research outputs found
The effects of upper and lower limb exercise on the microvascular reactivity in limited cutaneous systemic sclerosis patients
Background: Aerobic exercise in general and high intensity interval training (HIIT) specifically is known to improve vascular function in a range of clinical conditions. HIIT in particular has demonstrated improvements in clinical outcomes, in conditions that have a strong macroangiopathic component. Nevertheless, the effect of HIIT on microcirculation in systemic sclerosis (SSc) patients is yet to be investigated. Therefore, the purpose of the study was to compare the effects of two HIIT protocols (cycle and arm cranking) on the microcirculation of the digital area in SSc patients.
Methods: Thirty four limited cutaneous SSc patients (65.3 ± 11.6 years old) were randomly allocated in three groups (cycling, arm cranking and control group). The exercise groups underwent a twelve-week exercise program twice per week. All patients performed the baseline and post-exercise intervention measurements where physical fitness, functional ability, transcutaneous oxygen tension (ΔtcpO2), body composition and quality of life were assessed. Endothelial-dependent as well as-independent vasodilation were assessed in the middle and index fingers using LDF and incremental doses of acetylcholine (ACh) and sodium nitroprusside (SNP). Cutaneous flux data were expressed as cutaneous vascular conductance (CVC).
Results: Peak oxygen uptake increased in both exercise groups (p<0.01, d=1.36). ΔtcpO2 demonstrated an increase in the arm cranking group only, with a large effect, but not found statistically significant,(p=0.59, d=0.93). Endothelial-dependent vasodilation improvement was greater in the arm cranking (p<0.05, d=1.07) in comparison to other groups. Both exercise groups improved life satisfaction (p<0.001) as well as reduced discomfort and pain due to Raynaud's phenomenon (p<0.05). Arm cranking seems to be the preferred mode of exercise for study participants as compared to cycling (p<0.05). No changes were observed in the body composition or the functional ability in both exercise groups.
Conclusion: Our results suggest that arm cranking has the potential to improve the microvascular endothelial function in SSc patients. Also notably, our recommended training dose (e.g., a 12-week HIIT program, twice per week), appeared to be sufficient and tolerable for this population. Future research should focus on exploring the feasibility of a combined exercise such as aerobic and resistance training by assessing individual's experience and the quality of life in SSc patients.
Trial registration: ClinicalTrials.gov (NCT number): NCT03058887, February 23, 2017, https://clinicaltrials.gov/ct2/show/NCT03058887?term=NCT03058887&rank=1
Key words: High intensity interval training, vascular function, quality of lif
Modulation of epithelial sodium channel (ENaC) expression in mouse lung infected with Pseudomonas aeruginosa
BACKGROUND: The intratracheal instillation of Pseudomonas aeruginosa entrapped in agar beads in the mouse lung leads to chronic lung infection in susceptible mouse strains. As the infection generates a strong inflammatory response with some lung edema, we tested if it could modulate the expression of genes involved in lung liquid clearance, such as the α, β and γ subunits of the epithelial sodium channel (ENaC) and the catalytic subunit of Na(+)-K(+)-ATPase. METHODS: Pseudomonas aeruginosa entrapped in agar beads were instilled in the lung of resistant (BalB/c) and susceptible (DBA/2, C57BL/6 and A/J) mouse strains. The mRNA expression of ENaC and Na(+)-K(+)-ATPase subunits was tested in the lung by Northern blot following a 3 hours to 14 days infection. RESULTS: The infection of the different mouse strains evoked regulation of α and β ENaC mRNA. Following Pseudomonas instillation, the expression of αENaC mRNA decreased to a median of 43% on days 3 and 7 after infection and was still decreased to a median of 45% 14 days after infection (p < 0.05). The relative expression of βENaC mRNA was transiently increased to a median of 241%, 24 h post-infection before decreasing to a median of 43% and 54% of control on days 3 and 7 post-infection (p < 0.05). No significant modulation of γENaC mRNA was detected although the general pattern of expression of the subunit was similar to α and β subunits. No modulation of α(1)Na(+)-K(+)-ATPase mRNA, the catalytic subunit of the sodium pump, was recorded. The distinctive expression profiles of the three subunits were not different, between the susceptible and resistant mouse strains. CONCLUSIONS: These results show that Pseudomonas infection, by modulating ENaC subunit expression, could influence edema formation and clearance in infected lungs
Original Article
The pancreas taken from the frog (Rana nigromaculata) was fixed in 1% OsO_4 and sliced into ultrathin sections for electron microscopic studies. The following observations were made: 1. A great \u27number of minute granules found in the cytoplasm of a pancreatic cell were called the microsomes, which were divided into two types, the C-microsome and S-microsome. 2. Electron microsopic studies of the ergastoplasm showed that it is composed of the microsome granules and A-substance. The microsomes were seen embedded in the A-substance which was either filamentous or membranous. The membranous structure, which was called the Am-membrane, was seen to form a sac, with a cavity of varying sizes, or to form a lamella. 3. The Am-membrane has close similarity to α-cytomembrane of Sjostrand, except that the latter is rough-surfaced. It was deduced that the Am-membrane, which is smooth-surfaced, might turn into the rough-surfaced α-cytomembrane. 4. There was the Golgi apparatus in the supranuclear region of a pancreatic cell. It consisted of the Golgi membrane, Golgi vacuole and. Golgi vesicle. 5. The mitochondria of a pancreatic cell appeared like long filaments, and some of them were seen to ramify. 6. The membrane of mitochondria, i. e. the limiting membrane, consisted of the Ammembrane. The mitochondria contained a lot of A-substances, as well as the C-microsomes and S-microsomes. When the mitochondria came into being, there appeared inside them chains of granules, which appeared like strips of beads, as the outgrowths of the A-substance and the microsome granules attached to the Am-membrane. They are the so-called cristae mitochondriales. 7. The secretory granules originate in the microsomes. They came into being when the microsomes gradually thickened and grew in size as various substances became adhered to them. Some of the secretory granules were covered with a membrane and appeared like what they have called the intracisternal granule of Palade.It seemed that this was a phenomenon attendant upon the dissolution and liqutefaction of the secretory granule. 8. Comparative studies were made of the ergastoplasm of the pancreatic cells from the frogs in hibernation, the frogs artificially hungered, the frogs which were given food after a certain period of fasting, the frogs to which pilocarpine was given subcutaneously, and the very young, immature frogs. The studies revealed that the ergastoplasm of the pancreatic cells greatly varied in form with the difference in nutritive condition and with different developmental stages of the cell. The change in form and structure occured as a result of transformation of the microsomes and A-substance. The ergastoplasm, even after it has come into being, might easily be inactivated if nutrition is defective. The ergastoplasm is concerned in the secretory mechanism, which is different from the secretory phenomenon of the secretory granules. It would seem that structurally the mitochondria have no direct relation to this mechanism
Changes in perception of treatment efficacy are associated to the magnitude of the nocebo effect and to personality traits
The nocebo effect in motor performance consists in a reduction of force and increase of fatigue following the application of an inert treatment that the recipient believes to be effective. This effect is variable across individuals and it is usually stronger if conditioning -exposure to the active effect of the treatment- precedes a test session, in which the treatment is inert. In the current explorative study we used a conditioning procedure to investigate whether subjective perception of treatment effectiveness changes between the conditioning and the test session and whether this change is related to dispositional traits and to the nocebo-induced reduction of force. Results showed that 56.1% of participants perceived the treatment as more effective in the test than in the conditioning session, had a more pronounced reduction of force, felt more effort and sense of weakness and were characterized by lower levels of optimism and higher anxiety traits compared to the other 43.9% of participants, who conversely perceived the treatment as less effective in the test session than in the conditioning. These findings highlight for the first time a link between changes in perception of treatment effectiveness, personality traits and the magnitude of the nocebo response in motor performance
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HIV-1 Tat protein induces production of proinflammatory cytokines by human dendritic cells and monocytes/macrophages through engagement of TLR4-MD2-CD14 complex and activation of NF-κB pathway
Copyright © 2015 Ben Haij et al. We recently reported that the human immunodeficiency virus type-1 (HIV-1) Tat protein induced the expression of programmed death ligand-1 (PD-L1) on dendritic cells (DCs) through a TLR4 pathway. However, the underlying mechanisms by which HIV-1 Tat protein induces the abnormal hyper-activation of the immune system seen in HIV-1 infected patients remain to be fully elucidated. In the present study, we report that HIV-1 Tat protein induced the production of significant amounts of the pro-inflammatory IL-6 and IL-8 cytokines by DCs and monocytes from both healthy and HIV-1 infected patients. Such production was abrogated in the presence of anti-TLR4 blocking antibodies or soluble recombinant TLR4-MD2 as a decoy receptor, suggesting TLR4 was recruited by Tat protein. Tat-induced murine IL-6 and CXCL1/KC a functional homologue of human IL-8 was abolished in peritoneal macrophages derived from TLR4 KO but not from Wt mice, confirming the involvement of the TLR4 pathway. Furthermore, the recruitment of TLR4-MD2-CD14 complex by Tat protein was demonstrated by the activation of TLR4 downstream pathways including NF-κB and SOCS-1 and by down-modulation of cell surface TLR4 by endocytosis in dynamin and lipid-raft-dependent manners. Collectively, these findings demonstrate, for the first time, that HIV-1 Tat interacts with TLR4-MD2-CD14 complex and activates the NF-κB pathway, leading to overproduction of IL-6 and IL-8 pro-inflammatory cytokines by myeloid cells from both healthy and HIV-1 infected patients. This study reveals a novel mechanism by which HIV-1, via its early expressed Tat protein, hijacks the TLR4 pathway, hence establishing abnormal hyper-activation of the immune system
Prevention of deep vein thrombosis after hip replacement--comparison between two low-molecular heparins, tinzaparin and enoxaparin
Consecutive patients undergoing total hip replacement in 43 centres were randomly assigned to receive blindly either enoxaparin (40 mg) or tinzaparin (4,500 anti-Factor IU Xa), as once daily subcutaneous injections. The first injection was administered 12 h preoperatively. Efficacy was assessed by bilateral venography performed 12-14 days postoperatively. Efficacy and safety were blindly and centrally adjudicated. Among the 499 patients included, 440 had a venogram. The total incidence of DVTs was 44 (20.1%) of the 219 patients of the enoxaparin group and 48 (21.7%) of the 221 patients of the tinzaparin group. The upper limit of the 80% confidence interval of the difference between the two treatment groups was less than 5.0%. Therefore according to the protocol's specifications equivalence was shown. Proximal DVTs occurred in 10.5% of the enoxaparin group (23 patients) and in 9.5% (21 patients) of the tinzaparin group. No overt major bleeding was observed. One patient in the enoxaparin group developed severe thrombocytopenia and died. The LMWH tinzaparin appears clinically to be as effective and safe as enoxaparin in the prophylaxis of deep vein thrombosis after total hip replacement, at the doses used and under the conditions of this stud