scholarly journals Influence of CYP2C8, CYP3A4, and CYP3A5 Host Genotypes on Early Recurrence of Plasmodium vivax

2020 ◽  
Vol 64 (7) ◽  
Author(s):  
Anne C. G. Almeida ◽  
Maria C. B. Puça ◽  
Erick F. G. Figueiredo ◽  
Laila R. Barbosa ◽  
Yanka E. A. R. Salazar ◽  
...  
Keyword(s):  
Plasmodium Vivax ◽  
Ex Vivo ◽  
Plasma Concentrations ◽  
Similar Efficacy ◽  
Early Recurrence ◽  
Control Group ◽  
Recurrence Rates ◽  
Mutant Genotype ◽  
Content Type

ABSTRACT Cytochrome P450 (CYP) enzymes are involved in the biotransformation of chloroquine (CQ), but the role of the different profiles of metabolism of this drug in relation to Plasmodium vivax recurrences has not been properly investigated. To investigate the influence of the CYP genotypes associated with CQ metabolism on the rates of P. vivax early recurrences, a case-control study was carried out. The cases included patients presenting with an early recurrence (CQ-recurrent individuals), defined as a recurrence during the first 28 days after initial infection and plasma concentrations of CQ plus desethylchloroquine (DCQ; the major CQ metabolite) higher than 100 ng/ml. A control group with no parasite recurrence over the follow-up (the CQ-responsive group) was also included. CQ and DCQ plasma levels were measured on day 28. CQ-metabolizing CYP (CYP2C8, CYP3A4, and CYP3A5) genotypes were determined by real-time PCR. An ex vivo study was conducted to verify the efficacy of CQ and DCQ against P. vivax isolates. The frequency of alleles associated with normal and slow metabolism was similar between the cases and the controls for the CYP2C8 (odds ratio [OR] = 1.45, 95% confidence interval [CI] = 0.51 to 4.14, P = 0.570), CYP3A4 (OR = 2.38, 95% CI = 0.92 to 6.19, P = 0.105), and CYP3A5 (OR = 4.17, 95% CI = 0.79 to 22.04, P = 1.038) genes. DCQ levels were higher than CQ levels, regardless of the genotype. Regarding the DCQ/CQ ratio, there was no difference between groups or between those patients who had a normal genotype and those patients who had a mutant genotype. DCQ and CQ showed similar efficacy ex vivo. CYP genotypes had no influence on early recurrence rates. The similar efficacy of CQ and DCQ ex vivo could explain the absence of therapeutic failure, despite the presence of alleles associated with slow metabolism.

scholarly journals Direct evidence for a key role of protein kinase C in the development of vasospasm after subarachnoid hemorrhage

1992 ◽  
Vol 76 (4) ◽  
pp. 635-639 ◽  
Author(s):  
Shigeru Nishizawa ◽  
Nobukazu Nezu ◽  
Kenichi Uemura
Keyword(s):  
Signal Transduction ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Direct Evidence ◽  
Control Group ◽  
Content Type ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Fine Print

✓ Vascular contraction is induced by the activation of intracellular contractile proteins mediated through signal transduction from the outside to the inside of cells. Protein kinase C plays a crucial role in this signal transduction. It is hypothesized that protein kinase C plays a causative part in the development of vasospasm after subarachnoid hemorrhage (SAH). To verify this directly, the authors measured protein kinase C activity in canine basilar arteries in an SAH model with (γ-32P)adenosine triphosphate and the data were compared to those in a control group. Protein kinase C is translocated to the membrane from the cytosol when it is activated, and the translocation is an index of the activation; thus, protein kinase C activity was measured both in the cytosol and in the membrane fractions. Protein kinase C activity in the membrane in the SAH model was remarkably enhanced compared to that in the control group. The percentage of membrane activity to the total was also significantly greater in the SAH vessels than in the control group, and the percentage of cytosol activity in the SAH group was decreased compared to that in the control arteries. The results indicate that protein kinase C in the vascular smooth muscle was translocated to the membrane from the cytosol and was activated when SAH occurred. It is concluded that this is direct evidence for a key role of protein kinase C in the development of vasospasm.

scholarly journals Increased Interleukin-11 Levels Are Correlated with Cardiac Events in Patients with Chronic Heart Failure

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Ye ◽  
Zhen Wang ◽  
Di Ye ◽  
Yuan Wang ◽  
Menglong Wang ◽  
...  
Keyword(s):  
Heart Failure ◽  
Plasma Concentrations ◽  
Heart Association ◽  
Functional Class ◽  
Control Group ◽  
Class Iii ◽  
Cardiac Events ◽  
Nyha Functional Class ◽  
Interleukin 11

Background. Interleukin-11 (IL-11) is an important inflammatory cytokine and has been demonstrated to participate in cardiovascular diseases. However, there have been no studies about the role of IL-11 in heart failure (HF). The present study is aimed at investigating whether IL-11 levels are associated with the cardiac prognosis in patients with HF. Methods. The plasma concentrations of IL-11 were measured in 240 patients with chronic HF (CHF) and 80 control subjects without signs of significant heart disease. In addition, we prospectively followed these CHF patients to endpoints of cardiac events. Results. Compared with the control group, the plasma IL-11 concentrations were significantly increased in the CHF patients and gradually increased in the New York Heart Association (NYHA) functional class II group, the NYHA functional class III group, and the NYHA functional class IV group. The receiver operating characteristic (ROC) curve revealed that the predictive role of IL-11 in HF is not as good as N-terminal B-type natriuretic peptide (BNP), although IL-11 has a certain value in predicting cardiac events. In addition, the CHF patients were divided into 3 groups according to the plasma IL-11 concentration category (low, T1; middle, T2; and high, T3). The multivariate Cox hazard analysis showed that the high plasma IL-11 concentrations were independently associated with the presence of cardiac events after adjustment for confounding factors. Furthermore, the CHF patients were divided into two groups based on the median plasma IL-11 concentrations. The Kaplan-Meier analysis revealed that the patients with high IL-11 concentrations had a higher risk of cardiac events compared with those with low IL-11 concentrations. Conclusions. Higher plasma IL-11 levels significantly increase the presence of cardiac events and suggest a poor outcome; although the diagnostic value of IL-11 in CHF is not as good as BNP, there is a certain value in predicting cardiac events in CHF.

scholarly journals Intermediaries and social entrepreneurship identity: implications for business model innovation

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Maribel Guerrero ◽  
Carlos A. Santamaría-Velasco ◽  
Raj Mahto
Keyword(s):  
Business Model ◽  
Social Entrepreneurship ◽  
Economic Value ◽  
Control Group ◽  
Innovation Ecosystem ◽  
Content Type ◽  
The Social ◽  
Depth Analysis ◽  
Social Innovations

PurposeThe authors propose a theoretical basis for understanding the role of ecosystem intermediaries in the configuration of social entrepreneurship identities in social purpose organisations (SPOs) and their business model innovations (BMIs).Design/methodology/approachAdopting a retrospective multiple-case study, the authors offer insights into the paths/elements that determine the building of 44 social entrepreneurship identities in the context of an emerging economy (Mexico).FindingsThe study sheds light on the role of intermediaries in the configuration of the entrepreneurial identities of Mexican SPOs and BMIs, as well as several externalities generated during the process of capturing the social and economic value, especially when social innovations are focussed on solving societal, economic and ecological social problems.Research limitations/implicationsThe first limitation is related to the analysis of intermediaries within the social entrepreneurship ecosystem, which needs more conceptual and empirical evidence. The second limitation is that the analysis focussed only on intervened SPOs, as the authors did not control for non-intervened SPOs. Thus, this allows for future in-depth analysis of intermediary efficiency in a focus group (intervened SPOs) and a control group (non-intervened SPOs).Practical implicationsThe study also provides insights for Mexican SPOs on how a social entrepreneurship identity helps to capture the value creation of social innovations within an innovation ecosystem. Indeed, it is strongly aligned with the United Nations' Social Development Goals.Originality/valueThe study enhances the discussion about how intermediaries could encourage social entrepreneurial identity, as well as how intermediary intervention could facilitate the design and implementation of BMIs in the innovation ecosystem.

Role of endothelin-1 in neointima formation after endothelial removal in rabbit carotid arteries

1994 ◽  
Vol 267 (6) ◽  
pp. H2259-H2267 ◽  
Author(s):  
H. Azuma ◽  
H. Hamasaki ◽  
Y. Niimi ◽  
T. Terada ◽  
O. Matsubara
Keyword(s):  
Time Course ◽  
Plasma Concentrations ◽  
Tissue Level ◽  
Nuclear Antigen ◽  
Control Group ◽  
Receptor Subtype ◽  
Neointima Formation ◽  
Subtype B ◽  
Selective Ligand

To investigate the role of local endothelin (ET)-1 in neointima formation, we performed a balloon denudation in the rabbit carotid artery. Four weeks after denudation, regeneration of endothelial cells was almost complete, and a marked intimal hyperplasia was observed. The tissue level of ET-1-like immunoreactivity was significantly increased even at 24 and 72 h after denudation and was 9.3 times higher than the control group in 4 wk. On the same time course, the proliferating cell nuclear antigen (PCNA)-positive cells clearly appeared. Receptor density values for 125I-ET-1 and 125I-IRL-1620 [ET-receptor subtype B (ETB)-selective ligand] bindings were significantly greater in the hyperplastic artery without changes in dissociation equilibrium constant values. The 125I-ET-1 binding sites not inhibited with BQ-123 [ET-receptor subtype A (ETA)-selective antagonist] were significantly increased in hyperplastic arteries. ETB receptors were more densely localized in the neointima. The chronic intravenous administration of BQ-123 at plasma concentrations sufficient to antagonize the ETA receptors had no effect on neointima formation and the appearance of PCNA-positive cells. We concluded from all results that ET-1 would be involved in neointima formation after endothelial removal and that the ETA receptors would not play a role in this process.

scholarly journals Thioridazine Is an Efflux Pump Inhibitor in Mycobacterium avium Complex but of Limited Clinical Relevance

2020 ◽  
Vol 64 (7) ◽  
Author(s):  
Mike Marvin Ruth ◽  
Lian J. Pennings ◽  
Valerie A. C. M. Koeken ◽  
Jodie A. Schildkraut ◽  
Aria Hashemi ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Avium Complex ◽  
Efflux Pump ◽  
Ex Vivo ◽  
Plasma Concentrations ◽  
Intracellular Growth ◽  
Macrophage Infection ◽  
Efflux Pump Inhibitor ◽  
Content Type ◽  
Time Kill

ABSTRACT Treatment of Mycobacterium avium complex pulmonary disease (MAC-PD) is challenging partly due to high efflux pump expression. Thioridazine might block these efflux pumps. We explore the efficacy of thioridazine against M. avium isolates using MICs, time-kill combination assays, ex vivo macrophage infection assays, and efflux assays. Thioridazine is bactericidal against M. avium, inhibits intracellular growth at 2× MIC, and blocks ethidium bromide efflux. However, its toxicity and low plasma concentrations make it unlikely to add efficacy to MAC-PD therapy.

scholarly journals Na+/H+Antiport Is Essential for Yersinia pestis Virulence

2013 ◽  
Vol 81 (9) ◽  
pp. 3163-3172 ◽  
Author(s):  
Yusuke Minato ◽  
Amit Ghosh ◽  
Wyatt J. Faulkner ◽  
Erin J. Lind ◽  
Sara Schesser Bartra ◽  
...  
Keyword(s):  
Yersinia Pestis ◽  
Drug Target ◽  
Deletion Mutant ◽  
Ex Vivo ◽  
Ion Homeostasis ◽  
Content Type ◽  
Double Deletion ◽  
Derivative Strain

ABSTRACTNa+/H+antiporters are ubiquitous membrane proteins that play a central role in the ion homeostasis of cells. In this study, we examined the possible role of Na+/H+antiport inYersinia pestisvirulence and found thatY. pestisstrains lacking the major Na+/H+antiporters, NhaA and NhaB, are completely attenuated in anin vivomodel of plague. TheY. pestisderivative strain lacking thenhaAandnhaBgenes showed markedly decreased survival in blood and blood serumex vivo. Complementation of eithernhaAornhaBintransrestored the survival of theY. pestis nhaA nhaBdouble deletion mutant in blood. ThenhaA nhaBdouble deletion mutant also showed inhibited growth in an artificial serum medium, Opti-MEM, and a rich LB-based medium with Na+levels and pH values similar to those for blood. Taken together, these data strongly suggest that intact Na+/H+antiport is indispensable for the survival ofY. pestisin the bloodstreams of infected animals and thus might be regarded as a promising noncanonical drug target for infections caused byY. pestisand possibly for those caused by other blood-borne bacterial pathogens.

scholarly journals Dectin-1-Dependent Interleukin-22 Contributes to Early Innate Lung Defense against Aspergillus fumigatus

2011 ◽  
Vol 80 (1) ◽  
pp. 410-417 ◽  
Author(s):  
Melissa A. Gessner ◽  
Jessica L. Werner ◽  
Lauren M. Lilly ◽  
Michael P. Nelson ◽  
Allison E. Metz ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Ex Vivo ◽  
Lung Cells ◽  
Lipocalin 2 ◽  
Beta Glucan ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Deficient Mice ◽  
Lung Defense

ABSTRACTWe have previously reported that mice deficient in the beta-glucan receptor Dectin-1 displayed increased susceptibility toAspergillus fumigatuslung infection in the presence of lower interleukin 23 (IL-23) and IL-17A production in the lungs and have reported a role for IL-17A in lung defense. As IL-23 is also thought to control the production of IL-22, we examined the role of Dectin-1 in IL-22 production, as well as the role of IL-22 in innate host defense againstA. fumigatus. Here, we show that Dectin-1-deficient mice demonstrated significantly reduced levels of IL-22 in the lungs early afterA. fumigatuschallenge. Culturing cells from enzymatic lung digestsex vivofurther demonstrated Dectin-1-dependent IL-22 production. IL-22 production was additionally found to be independent of IL-1β, IL-6, or IL-18 but required IL-23. The addition of recombinant IL-23 augmented IL-22 production in wild-type (WT) lung cells and rescued IL-22 production by lung cells from Dectin-1-deficient mice.In vivoneutralization of IL-22 in the lungs of WT mice resulted in impairedA. fumigatuslung clearance. Moreover, mice deficient in IL-22 also demonstrated a higher lung fungal burden afterA. fumigatuschallenge in the presence of impaired IL-1α, tumor necrosis factor alpha (TNF-α), CCL3/MIP-1α, and CCL4/MIP-1β production and lower neutrophil recruitment, yet intact IL-17A production. We further show that lung lavage fluid collected from bothA. fumigatus-challenged Dectin-1-deficient and IL-22-deficient mice had compromised anti-fungal activity againstA. fumigatus in vitro. Although lipocalin 2 production was observed to be Dectin-1 and IL-22 dependent, lipocalin 2-deficient mice did not demonstrate impairedA. fumigatusclearance. Moreover, lungS100a8,S100a9, andReg3gmRNA expression was not lower in either Dectin-1-deficient or IL-22-deficient mice. Collectively, our results indicate that early innate lung defense againstA. fumigatusis mediated by Dectin-1-dependent IL-22 production.

scholarly journals Population Pharmacokinetic/Pharmacodynamic Analysis of the Bactericidal Activities of Sutezolid (PNU-100480) and Its Major Metabolite against Intracellular Mycobacterium tuberculosis inEx VivoWhole-Blood Cultures of Patients with Pulmonary Tuberculosis

2014 ◽  
Vol 58 (6) ◽  
pp. 3306-3311 ◽  
Author(s):  
Tong Zhu ◽  
Sven O. Friedrich ◽  
Andreas Diacon ◽  
Robert S. Wallis
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Hollow Fiber ◽  
Ex Vivo ◽  
Parent Compound ◽  
Plasma Concentrations ◽  
Population Pharmacokinetic ◽  
Model Parameters ◽  
Data Set ◽  
Content Type

ABSTRACTSutezolid (PNU-100480 [U-480]) is an oxazolidinone antimicrobial being developed for the treatment of tuberculosis. An active sulfoxide metabolite (PNU-101603 [U-603]), which reaches concentrations in plasma several times those of the parent, has been reported to drive the killing of extracellularMycobacterium tuberculosisby sutezolid in hollow-fiber culture. However, the relative contributions of the parent and metabolite against intracellularM. tuberculosisin vivoare not fully understood. The relationships between the plasma concentrations of U-480 and U-603 and intracellular whole-blood bactericidal activity (WBA) inex vivocultures were examined using a direct competitive population pharmacokinetic (PK)/pharmacodynamic 4-parameter sigmoid model. The data set included 690 PK determinations and 345 WBA determinations from 50 tuberculosis patients enrolled in a phase 2a sutezolid trial. The model parameters were solved iteratively. The median U-603/U-480 concentration ratio was 7.1 (range, 1 to 28). The apparent 50% inhibitory concentration of U-603 for intracellularM. tuberculosiswas 17-fold greater than that of U-480 (90% confidence interval [CI], 9.9- to 53-fold). Model parameters were used to simulatein vivoactivity after oral dosing with sutezolid at 600 mg twice a day (BID) and 1,200 mg once a day (QD). Divided dosing resulted in greater cumulative activity (−0.269 log10per day; 90% CI, −0.237 to −0.293 log10per day) than single daily dosing (−0.186 log10per day; 90% CI, −0.160 to −0.208 log10per day). U-480 accounted for 84% and 78% of the activity for BID and QD dosing, respectively, despite the higher concentrations of U-603. Killing of intracellularM. tuberculosisby orally administered sutezolid is mainly due to the activity of the parent compound. Taken together with the findings of other studies in the hollow-fiber model, these findings suggest that sutezolid and its metabolite act on different mycobacterial subpopulations.

Studies of experimental cervical spinal cord transection

1979 ◽  
Vol 50 (5) ◽  
pp. 629-632 ◽  
Author(s):  
Phillip A. Tibbs ◽  
Byron Young ◽  
Michael G. Ziegler ◽  
R. G. McAllister
Keyword(s):  
Spinal Cord ◽  
Cervical Spinal Cord ◽  
Plasma Concentrations ◽  
Spinal Cord Transection ◽  
Cervical Cord ◽  
Control Group ◽  
Content Type ◽  
Hemorrhagic Necrosis ◽  
Anesthetized Dogs ◽  
Experimental Group

✓ Plasma concentrations of norepinephrine (NE) were measured by a radioenzymatic assay technique before and serially after laminectomy at the C-6 level in 14 anesthetized dogs. In half the animals, no further procedures were carried out (control group); in the other dogs, cervical cord transection was performed in addition to laminectomy (experimental group). Mean plasma NE levels were similar in both groups after laminectomy and before cord interruption. In the control group, NE levels increased gradually for 2 hours after the procedure. In the group with cord transection, however, NE rose immediately after transection to 267% of the baseline value, then fell to 25% of the plasma NE level in the control group at 30 minutes, 29% at 60 minutes, and 15% at 120 minutes. Cervical spinal cord transection, therefore, results in an abrupt but short-lived increase in plasma NE concentrations. These changes in plasma NE levels may explain, at least in part, the hemodynamic alterations and the acute central hemorrhagic necrosis that occur after high spinal cord trauma.

scholarly journals Population Pharmacokinetic and Pharmacodynamic Modeling of Amodiaquine and Desethylamodiaquine in Women with Plasmodium vivax Malaria during and after Pregnancy

2012 ◽  
Vol 56 (11) ◽  
pp. 5764-5773 ◽  
Author(s):  
Joel Tarning ◽  
Palang Chotsiri ◽  
Vincent Jullien ◽  
Marcus J. Rijken ◽  
Martin Bergstrand ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Plasmodium Vivax ◽  
Plasma Concentrations ◽  
Inhibitory Effect ◽  
Biologically Active ◽  
Pharmacodynamic Modeling ◽  
Population Pharmacokinetic ◽  
Content Type ◽  
Plasmodium Vivax Malaria

ABSTRACTAmodiaquine is effective for the treatment ofPlasmodium vivaxmalaria, but there is little information on the pharmacokinetic and pharmacodynamic properties of amodiaquine in pregnant women with malaria. This study evaluated the population pharmacokinetic and pharmacodynamic properties of amodiaquine and its biologically active metabolite, desethylamodiaquine, in pregnant women withP. vivaxinfection and again after delivery. Twenty-seven pregnant women infected withP. vivaxmalaria on the Thai-Myanmar border were treated with amodiaquine monotherapy (10 mg/kg/day) once daily for 3 days. Nineteen women, with and withoutP. vivaxinfections, returned to receive the same amodiaquine dose postpartum. Nonlinear mixed-effects modeling was used to evaluate the population pharmacokinetic and pharmacodynamic properties of amodiaquine and desethylamodiaquine. Amodiaquine plasma concentrations were described accurately by lagged first-order absorption with a two-compartment disposition model followed by a three-compartment disposition of desethylamodiaquine under the assumption of completein vivoconversion. Body weight was implemented as an allometric function on all clearance and volume parameters. Amodiaquine clearance decreased linearly with age, and absorption lag time was reduced in pregnant patients. Recurrent malaria infections in pregnant women were modeled with a time-to-event model consisting of a constant-hazard function with an inhibitory effect of desethylamodiaquine. Amodiaquine treatment reduced the risk of recurrent infections from 22.2% to 7.4% at day 35. In conclusion, pregnancy did not have a clinically relevant impact on the pharmacokinetic properties of amodiaquine or desethylamodiaquine. No dose adjustments are required in pregnancy.

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