correction to unpacking configurational dynamics sequence analysis and qualitative comparative analysis as a mixed method design

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Bortezomib represses HIF-1 alpha protein expression and nuclear accumulation by inhibiting both PI3K/Akt/TOR and MAPK pathways in prostate cancer cells

Bortezomib represents the first proteasome inhibitor (PI) with demonstrated antitumor activity in the clinical setting, particularly for treatment of hematological malignancies. At the preclinical level, its action is shown to be mediated by induction of growth arrest and apoptosis in many tumor types, including androgen-dependent (AD) and androgen-independent (AI) prostate cancer (PCa) cells. Hypoxiainducible factor-1 alpha (HIF-1 alpha), which is directly involved in tumor growth, is one of the most studied and promising molecular targets for anti-cancer therapy and is often overexpressed in PCa. Bortezomib has been reported to impair tumor growth by also inhibiting HIF-1 alpha. In this study, we investigated the effect of bortezomib on the expression, activity and localization of HIF-1 alpha in LNCaP (AD) and PC3 (AI) PCa cells. First, we show that hypoxic upregulation of HIF-1 alpha protein levels and activity involves both the PI3K/Akt/mTOR and p44/42 MAPK pathways. Second, bortezomib inhibits expression of HIF-1 alpha protein under both normoxic and hypoxic conditions, represses HIF-1 transcriptional activity and attenuates the release of vascular endothelial growth factor. These effects correlate with the ability of bortezomib to cause dephosphorylation of phospho-Akt, phospho-p70S6K, and phospho-S6RP, thus inactivating a pathway known to be required for HIF-1 alpha protein expression at the translational level. Furthermore, bortezomib also abrogates p44/42 MAPK phosphorylation, which results to reduced nuclear translocation of HIF-1 alpha. Taken together, these results suggest that bortezomib inhibits HIF-1 alpha protein synthesis and its nuclear targeting through suppression of PI3K/Akt/mTOR and MAPK pathways, respectively, in both AD and AI PCa cells

High-tidal-volume mechanical ventilation and lung inflammation in intensive care patients with normal lungs

Background This study was conducted to investigate whether high-tidal-volume mechanical ventilation is associated with increased lung inflammation compared with low-tidal-volume mechanical ventilation in critically ill patients with no evidence of lung injury. Methods In this prospective, single-blind, randomized (1:1), parallel-group study, 18 critically ill patients with normal lungs were randomly assigned to receive mechanical ventilation with a tidal volume of either 6 mL/kg (low tidal volume) or 12 mL/kg (high tidal volume) during the first 4 days in the intensive care unit. Results At baseline and at 24, 48, and 96 hours, exhaled breath condensate was collected to measure interleukin 1β, interleukin 10, tumor necrosis factor α, and total nitric oxide metabolites. Interleukin 1β levels in exhaled breath condensate were significantly increased at 24 hours compared with baseline in the high-tidal-volume group but not in the low-tidal-volume group. The interleukin 1β increase in the high-tidal-volume group was transient. Exhaled breath condensate levels of interleukin 1β, interleukin 10, tumor necrosis factor α, and total nitric oxide metabolites did not differ significantly between the high-tidal-volume and low-tidal-volume groups at any time point. Conclusion Short-term mechanical ventilation with a tidal volume of 12 mL/kg may trigger inflammatory responses in the lungs of intensive care unit patients without preexisting lung injury. (American Journal of Critical Care. ©2020 American Association of Critical-Care Nurses

Bortezomib represses HIF-1 alpha protein expression and nuclear accumulation by inhibiting both PI3K/Akt/TOR and MAPK pathways in prostate cancer cells (vol 90, pg 45, 2012)

Bortezomib represents the first proteasome inhibitor (PI) with demonstrated antitumor activity in the clinical setting, particularly for treatment of hematological malignancies. At the preclinical level, its action is shown to be mediated by induction of growth arrest and apoptosis in many tumor types, including androgen-dependent (AD) and androgen-independent (AI) prostate cancer (PCa) cells. Hypoxiainducible factor-1 alpha (HIF-1 alpha), which is directly involved in tumor growth, is one of the most studied and promising molecular targets for anti-cancer therapy and is often overexpressed in PCa. Bortezomib has been reported to impair tumor growth by also inhibiting HIF-1 alpha. In this study, we investigated the effect of bortezomib on the expression, activity and localization of HIF-1 alpha in LNCaP (AD) and PC3 (AI) PCa cells. First, we show that hypoxic upregulation of HIF-1 alpha protein levels and activity involves both the PI3K/Akt/mTOR and p44/42 MAPK pathways. Second, bortezomib inhibits expression of HIF-1 alpha protein under both normoxic and hypoxic conditions, represses HIF-1 transcriptional activity and attenuates the release of vascular endothelial growth factor. These effects correlate with the ability of bortezomib to cause dephosphorylation of phospho-Akt, phospho-p70S6K, and phospho-S6RP, thus inactivating a pathway known to be required for HIF-1 alpha protein expression at the translational level. Furthermore, bortezomib also abrogates p44/42 MAPK phosphorylation, which results to reduced nuclear translocation of HIF-1 alpha. Taken together, these results suggest that bortezomib inhibits HIF-1 alpha protein synthesis and its nuclear targeting through suppression of PI3K/Akt/mTOR and MAPK pathways, respectively, in both AD and AI PCa cells

Oxidative stress and inflammatory markers in the exhaled breath condensate of children with OSA

Obstructive sleep apnea (OSA) in children has been associated with systemic inflammation and oxidative stress. Limited evidence indicates that pediatric OSA is associated with oxidative stress and inflammation in the airway. The objective of this study is to assess the hypothesis that levels of oxidative stress and inflammatory markers in the exhaled breath condensate (EBC) of children with OSA are higher than those of control subjects. Participants were children with OSA and control subjects who underwent overnight polysomnography. Morning levels of hydrogen peroxide (H2O2) and sum of nitrite and nitrate (NO (x) ) in EBC of participants were measured. Twelve subjects with moderate-to-severe OSA (mean age +/- standard deviation: 6.3 +/- 1.7 years; apnea-hypopnea index-AHI, 13.6 +/- 10.1 episodes/h), 22 subjects with mild OSA (6.7 +/- 2.1 years; AHI, 2.8 +/- 1 episodes/h) and 16 control participants (7.7 +/- 2.4 years; AHI, 0.6 +/- 0.3 episodes/h) were recruited. Children with moderate-to severe OSA had higher log-transformed H2O2 concentrations in EBC compared to subjects with mild OSA, or to control participants: 0.4 +/- 1.1 versus -0.9 +/- 1.3 (p = 0.015), or versus -1.2 +/- 1.2 (p = 0.003), respectively. AHI and % sleep time with oxygen saturation of hemoglobin < 95% were significant predictors of log-transformed H2O2 after adjustment by age and body mass index z score (p < 0.05). No significant differences were demonstrated between the three study groups in terms of EBC NO (x) levels. Children with moderate-to-severe OSA have increased H2O2 levels in morning EBC, an indirect index of altered redox status in the respiratory tract

Insulin sensitivity increase after calcium supplementation and change in intraplatelet calcium and sodium-hydrogen exchange in hypertensive patients with Type 2 diabetes

To investigate the effect of oral calcium (Ca2+) supplementation on insulin sensitivity measured by the euglycaemic hyperinsulinaemic clamp, intraplatelet cationic concentration of Ca2+ ([Ca2+](i)) and the transmembrane sodium-hydrogen exchanger (NHE) activity in erythrocytes in subjects with Type 2 diabetes and hypertension. In this parallel randomized controlled single-blinded trial, 31 patients were allocated to receive either 1500 mg of Ca2+ orally, daily (n = 15) or no treatment (n = 16) for 8 weeks. At baseline and at the end of the 8-week period insulin sensitivity, [Ca2+](i) and the first isoform of NHE (NHE-1) activity were measured. At the end of the study, subjects who received Ca2+ supplementation showed higher insulin sensitivity (Delta M-value 0.32 +/- 0.5 mmol/min P < 0.05) and lower [Ca2+](i) (125.0 +/- 24.7 to 80.4 +/- 10.6 nmol/l, P < 0.05, mean +/- sem) and NHE-1 activity (79.5 +/- 10.0 to 52.1 +/- 6.4 mmol Na/l red cell/h, P < 0.05). None of the above parameters were changed in the control group. Simple regression analysis demonstrated the change in [Ca2+](i) significantly determined insulin sensitivity change (beta = -0.36, P < 0.05). Oral Ca2+ supplementation improves insulin sensitivity in patients with Type 2 diabetes and hypertension. These changes are likely to be mediated by changes in intracellular ionic Ca2+. NHE-1 activity was also reduced after Ca2+ supplementation but its role in insulin sensitivity requires further investigation

Low Oxygen Tension Enhances Hepatitis C Virus Replication

Low oxygen tension exerts a significant effect on the replication of several DNA and RNA viruses in cultured cells. In vitro propagation of hepatitis C virus (HCV) has thus far been studied under atmospheric oxygen levels despite the fact that the liver tissue microenvironment is hypoxic. In this study, we investigated the efficiency of HCV production in actively dividing or differentiating human hepatoma cells cultured under low or atmospheric oxygen tensions. By using both HCV replicons and infection-based assays, low oxygen was found to enhance HCV RNA replication whereas virus entry and RNA translation were not affected. Hypoxia signaling pathway-focused DNA microarray and real-time quantitative reverse transcription-PCR (qRT-PCR) analyses revealed an upregulation of genes related to hypoxic stress, glycolytic metabolism, cell growth, and proliferation when cells were kept under low (3% [vol/vol]) oxygen tension, likely reflecting cell adaptation to anaerobic conditions. Interestingly, hypoxia-mediated enhancement of HCV replication correlated directly with the increase in anaerobic glycolysis and creatine kinase B (CKB) activity that leads to elevated ATP production. Surprisingly, activation of hypoxia-inducible factor alpha (HIF-alpha) was not involved in the elevation of HCV replication. Instead, a number of oncogenes known to be associated with glycolysis were upregulated and evidence that these oncogenes contribute to hypoxia-mediated enhancement of HCV replication was obtained. Finally, in liver biopsy specimens of HCV-infected patients, the levels of hypoxia and anaerobic metabolism markers correlated with HCV RNA levels. These results provide new insights into the impact of oxygen tension on the intricate HCV-host cell interaction