Para‐aminosalicylic acid significantly reduced tenofovir exposure in human subjects; mismatched findings from in vitro to in vivo translational research

2021 ◽  
Author(s):  
Md Masud Parvez ◽  
Said Kalkisim ◽  
Phuong Thi Thu Nguyen ◽  
Jin Ah. Jung ◽  
Jeong‐Kon Park ◽  
...  
Keyword(s):  
Translational Research ◽  
Human Subjects ◽  
Aminosalicylic Acid

Clock gene-independent daily regulation of haemoglobin oxidation in red blood cells

2021 ◽  
Author(s):  
Andrew D. Beale ◽  
Priya Crosby ◽  
Utham K. Valekunja ◽  
Rachel S. Edgar ◽  
Johanna E. Chesham ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Human Subjects ◽  
Developmental Regulation ◽  
Physiological Role ◽  
Cell Types ◽  
The Body

AbstractCellular circadian rhythms confer daily temporal organisation upon behaviour and physiology that is fundamental to human health and disease. Rhythms are present in red blood cells (RBCs), the most abundant cell type in the body. Being naturally anucleate, RBC circadian rhythms share key elements of post-translational, but not transcriptional, regulation with other cell types. The physiological function and developmental regulation of RBC circadian rhythms is poorly understood, however, partly due to the small number of appropriate techniques available. Here, we extend the RBC circadian toolkit with a novel biochemical assay for haemoglobin oxidation status, termed “Bloody Blotting”. Our approach relies on a redox-sensitive covalent haem-haemoglobin linkage that forms during cell lysis. Formation of this linkage exhibits daily rhythms in vitro, which are unaffected by mutations that affect the timing of circadian rhythms in nucleated cells. In vivo, haemoglobin oxidation rhythms demonstrate daily variation in the oxygen-carrying and nitrite reductase capacity of the blood, and are seen in human subjects under controlled laboratory conditions as well as in freely-behaving humans. These results extend our molecular understanding of RBC circadian rhythms and suggest they serve an important physiological role in gas transport.

scholarly journals Circulating vaspin and visfatin are not affected by acute or chronic energy deficiency or leptin administration in humans

2011 ◽  
Vol 164 (6) ◽  
pp. 911-917 ◽  
Author(s):  
Eun Seok Kang ◽  
Faidon Magkos ◽  
Elizabeth Sienkiewicz ◽  
Christos S Mantzoros
Keyword(s):  
Human Subjects ◽  
Normal Weight ◽  
Hypothalamic Amenorrhea ◽  
Energy Deficiency ◽  
Chronic Energy Deficiency ◽  
Before And After ◽  
Term Energy ◽  
Energy Deprivation

ObjectiveAnimal and in vitro studies indicate that leptin alleviates starvation-induced reduction in circulating vaspin and stimulates the production of visfatin. We thus examined whether vaspin and visfatin are affected by short- and long-term energy deprivation and leptin administration in human subjects in vivo.Design and methodsWe measured circulating levels of vaspin and visfatin i) before and after 72 h of starvation (leading to severe hypoleptinemia) with or without leptin administration in replacement doses in 13 normal-weight subjects, ii) before and after 72 h of starvation with leptin administration in pharmacological doses in 13 lean and obese subjects, iii) during chronic energy deficiency in eight women with hypothalamic amenorrhea on leptin replacement for 3 months, and iv) during chronic energy deficiency in 18 women with hypothalamic amenorrhea on leptin replacement or placebo for 3 months.ResultsAcute starvation decreased serum leptin to 21% of baseline values, (P=0.002) but had no significant effect on vaspin and visfatin concentrations (P>0.05). Nor did normalization of leptin levels affect the concentrations of these two adipokines (P>0.9). Leptin replacement in women with hypothalamic amenorrhea did not significantly alter vaspin and visfatin concentrations, whether relative to baseline or placebo administration (P>0.25). Pharmacological doses of leptin did not affect circulating vaspin and visfatin concentrations (P>0.9).ConclusionsCirculating vaspin and visfatin are not affected by acute or chronic energy deficiency leading to hypoleptinemia and are not regulated by leptin in human subjects, indicating that these adipocyte-secreted hormonal regulators of metabolism are independently regulated in humans.

scholarly journals Determination of activity of antioxidants in human subjects

1999 ◽  
Vol 58 (4) ◽  
pp. 1015-1024 ◽  
Author(s):  
Garry G. Duthie
Keyword(s):  
Oxidative Stress ◽  
Human Subjects ◽  
Control Schemes ◽  
Total Antioxidant ◽  
Plasma Measurements ◽  
Determination Of Activity ◽  
Nutritional Antioxidants

Evidence from biochemical and animal models suggests that nutritional antioxidants should inhibit the development of diseases such as CHD and certain cancers. This evidence is not clearly corroborated by intervention studies in human subjects, due, in part, to inadequacies in current analytical methodologies. Althoughin vitroassays can give useful information on the attributes required by a compound to act as an antioxidant, results may have little nutritional relevance due to limited bioavailability. The determination of antioxidants in blood is often used as a measure of antioxidant statusin vivo, but may not necessarily reflect concentrations in target tissues where oxidative stress is greatest. In addition, the accumulation of antioxidants in selective tissues may not be apparent from plasma measurements. Participation in quality-control schemes for antioxidant determination by HPLC allows inter-laboratory comparison of results. Moderation of indices of oxidative damage to lipids, proteins and DNA can provide information on the effectiveness of compounds as nutritional antioxidants. However, most current methods of assessing oxidative stress are subject to confounding factors of non-oxidative origin. Assays for total antioxidant capacity in plasma differ in their type of oxidation source, target and measurement used to detect the oxidized product. They give different results, should never be used in isolation, and results should be interpreted with caution. Until more is known about the activity and metabolic fate of antioxidants, caution should be exercised in the consumption of large amounts of commercially-available antioxidant preparations.

scholarly journals Assessing Uncertainty in A2 Respiratory Syncytial Virus Viral Dynamics

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Gilberto González-Parra ◽  
Hana M. Dobrovolny
Keyword(s):  
Respiratory Syncytial Virus ◽  
Human Subjects ◽  
Respiratory Illness ◽  
The United States ◽  
Viral Kinetics ◽  
Phase Duration ◽  
Syncytial Virus ◽  
Parameter Values

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and pneumonia in children younger than 1 year of age in the United States. Moreover, RSV is being recognized more often as a significant cause of respiratory illness in older adults. Although RSV has been studied both clinically and in vitro, a quantitative understanding of the infection dynamics is still lacking. In this paper, we study the effect of uncertainty in the main parameters of a viral kinetics model of RSV. We first characterize the RSV replication cycle and extract parameter values by fitting the mathematical model to in vivo data from eight human subjects. We then use Monte Carlo numerical simulations to determine how uncertainty in the parameter values will affect model predictions. We find that uncertainty in the infection rate, eclipse phase duration, and infectious lifespan most affect the predicted dynamics of RSV. This study provides the first estimate of in vivo RSV infection parameters, helping to quantify RSV dynamics. Our assessment of the effect of uncertainty will help guide future experimental design to obtain more precise parameter values.

scholarly journals Fermentation of non-starch polysaccharides in mixed diets and single fibre sources: comparative studies in human subjects andin vitro

1998 ◽  
Vol 80 (3) ◽  
pp. 253-261 ◽  
Author(s):  
Elisabeth Wisker ◽  
Martina Daniel ◽  
Gerhard Rave ◽  
Walter Feldheim
Keyword(s):  
Human Subjects ◽  
Single Fibre ◽  
Physiological Importance ◽  
Rye Bread ◽  
Batch System ◽  
The Difference ◽  
Mean Differences ◽  
Balance Trials

The present study investigated whether the extent of fermentation of NSP in human subjects could be predicted by anin vitrobatch system. Fibre sources studied were five mixed diets containing different amounts and types of fibre and three single fibre sources (citrus fibre concentrate, coarse and fine wholemeal rye bread). Fermentation in human subjects was determined in balance experiments in women who were also donors of the faecal inocula.In vitrofermentations were performed with fibre residues prepared from duplicates of the fibre-containing foods consumed during the balance trials. Fermentation of total NSPin vivowas between 65.8 and 88.6% for the mixed diets and 54.4, 58.0 and 96.9 % for the coarse and fine wholemeal rye breads and the citrus fibre concentrate respectively. For the mixed diets and the citrus fibre concentrate, mean differences between the extent of NSP degradation after 24 hin vitroincubation and thatin vivowere between −0.7 and 5.0 %. Differences were significant for one diet (P< 0.05). For the wholemeal rye breads, the fermentationin vitroexceeded thatin vivosignificantly, but the magnitude of the difference in each case was small and without physiological importance. Particle size of breads had no influence on the extent of NSP degradation. These results indicate that thein vitrobatch system used could provide quantitative data on the fermentationin vivoof NSP in mixed diets and some single fibre sources. Anin vitroincubation time of 24 h was sufficient to mimic the NSP degradationin vivo.

scholarly journals CD8+ T cells regulate liver injury in obesity-related nonalcoholic fatty liver disease

2020 ◽  
Vol 318 (2) ◽  
pp. G211-G224
Author(s):  
Denitra A. Breuer ◽  
Maria Cristina Pacheco ◽  
M. Kay Washington ◽  
Stephanie A. Montgomery ◽  
Alyssa H. Hasty ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cell Activation ◽  
Stellate Cell ◽  
Human Subjects ◽  
Smooth Muscle Actin ◽  
Nonalcoholic Fatty Liver ◽  
Novel Approach

Nonalcoholic steatohepatitis (NASH) has increased in Western countries due to the prevalence of obesity. Current interests are aimed at identifying the type and function of immune cells that infiltrate the liver and key factors responsible for mediating their recruitment and activation in NASH. We investigated the function and phenotype of CD8+ T cells under obese and nonobese NASH conditions. We found an elevation in CD8 staining in livers from obese human subjects with NASH and cirrhosis that positively correlated with α-smooth muscle actin, a marker of hepatic stellate cell (HSC) activation. CD8+ T cells were elevated 3.5-fold in the livers of obese and hyperlipidemic NASH mice compared with obese hepatic steatosis mice. Isolated hepatic CD8+ T cells from these mice expressed a cytotoxic IL-10-expressing phenotype, and depletion of CD8+ T cells led to significant reductions in hepatic inflammation, HSC activation, and macrophage accumulation. Furthermore, hepatic CD8+ T cells from obese and hyperlipidemic NASH mice activated HSCs in vitro and in vivo. Interestingly, in the lean NASH mouse model, depletion and knockdown of CD8+ T cells did not impact liver inflammation or HSC activation. We demonstrated that under obese/hyperlipidemia conditions, CD8+ T cell are key regulators of the progression of NASH, while under nonobese conditions they play a minimal role in driving the disease. Thus, therapies targeting CD8+ T cells may be a novel approach for treatment of obesity-associated NASH. NEW & NOTEWORTHY Our study demonstrates that CD8+ T cells are the primary hepatic T cell population, are elevated in obese models of NASH, and directly activate hepatic stellate cells. In contrast, we find CD8+ T cells from lean NASH models do not regulate NASH-associated inflammation or stellate cell activation. Thus, for the first time to our knowledge, we demonstrate that hepatic CD8+ T cells are key players in obesity-associated NASH.

scholarly journals Living myocardial slices: a novel multicellular model for cardiac translational research

2019 ◽  
Vol 41 (25) ◽  
pp. 2405-2408 ◽  
Author(s):  
Filippo Perbellini ◽  
Thomas Thum
Keyword(s):  
Translational Research ◽  
Cardiac Tissue ◽  
Heart Function ◽  
Cell Types ◽  
Human Model ◽  
Mechanical Stimuli ◽  
Cardiovascular Research ◽  
Functional Changes

Abstract Heart function relies on the interplay of several specialized cell types and a precisely regulated network of chemical and mechanical stimuli. Over the last few decades, this complexity has often been undervalued and progress in translational cardiovascular research has been significantly hindered by the lack of appropriate research models. The data collected are often oversimplified and these make the translation of results from the laboratory to clinical trials challenging and occasionally misleading. Living myocardial slices are ultrathin (100–400μm) sections of living cardiac tissue that maintain the native multicellularity, architecture, and structure of the heart and can provide information at a cellular/subcellular level. They overcome most of the limitations that affect other in vitro models and they can be prepared from human specimens, proving a clinically relevant multicellular human model for translational cardiovascular research. The publication of a reproducible protocol, and the rapid progress in methodological and technological discoveries which prevent significant structural and functional changes associated with chronic in vitro culture, has overcome the last barrier for the in vitro use of this human multicellular preparations. This technology can bridge the gap between in vitro and in vivo human studies and has the potential to revolutionize translational research approaches.

Morphological Distinction Unravels Mechanisms Of Platelet Biogenesis From Bone Marrow Megakaryocytes

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 2428-2428
Author(s):  
Satoshi Nishimura ◽  
Koji Eto ◽  
Ryozo Nagai
Keyword(s):  
Bone Marrow ◽  
Fluorescent Protein ◽  
Conflicts Of Interest ◽  
Human Subjects ◽  
Blood Platelets ◽  
Serum Levels ◽  
Cytokine Balance ◽  
Green Fluorescent

Abstract Blood platelets are generated in the bone marrow (BM) from their precursors, megakaryocytes (MK). Although we know that MKs produce platelets throughout life, precisely how platelets are produced in vivo remains uncertain, largely because of the rarity of MKs in the BM and the lack an adequate visualization technique. In the present study, we were able to visualize MK dynamics leading to platelet release in living animals at high resolution. To clearly understand the nature of thrombopoiesis in BM MKs, we optimized an in vivo imaging technique based on two-photon microscopy that enabled us to visualize living BM in CAG- enhanced green fluorescent protein (eGFP) mice. By visualizing living bone marrow in vivo, we observed that two modes (fragmentation and proplatelet formation) can be ongoing simultaneously in the same mouse. We observed that these two modes detectable by different morphological behavior can be ongoing simultaneously in the same BM of mouse, and are regulated by specific cytokines. Short proplatelets from megakaryocytes predominated at steady state, and more elongated proplatelets were accelerated by thrombopoietin (TPO) with responding to chronic platelet needs including recovery form BM transplantations. In contrast, acute platelet needs by blood loss, 5-FU administration or pritoneal acute inflammation increased cytoplasmic fragmentation following rapid ‘rupture’. Observed two modes are both dependent on tubulin reorganization on platelet biogenesis. In addition, platelet increase at acute phase is independent of proliferation by MK progenitors and this factor might exert apoptosis machinery on already reserved mature type of MKs. This humoral factor was identified by combination of in vitro screening systems and in vivo MK visualization analysis. Factor serum levels were reduced independently of the thrombopoietin level in human subjects with low platelet counts. It thus appears the cytokine balance dynamically regulates the mode of thrombopoiesis and the cellular programming of MKs. Thus, these novel factor may be a novel therapeutic target in thrombocytopenic situations, especially when associated with acute loss of platelets or when platelet transfusion is limited or unsuccessful. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Diclofenac and Its Acyl Glucuronide: Determination of In Vivo Exposure in Human Subjects and Characterization as Human Drug Transporter Substrates In Vitro

2015 ◽  
Vol 44 (3) ◽  
pp. 320-328 ◽  
Author(s):  
Y. Zhang ◽  
Y.-H. Han ◽  
S. P. Putluru ◽  
M. K. Matta ◽  
P. Kole ◽  
...  
Keyword(s):  
Human Subjects ◽  
Drug Transporter ◽  
Acyl Glucuronide
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