scholarly journals In vivo Measurement of the Volume of Distribution of Water in Cerebral Grey Matter: Effects on the Calculation of Regional Cerebral Blood Flow

1992 ◽  
Vol 12 (2) ◽  
pp. 291-295 ◽  
Author(s):  
A. A. Lammertsma ◽  
A. J. Martin ◽  
K. J. Friston ◽  
T. Jones
Keyword(s):  
Volume Of Distribution ◽  
Regional Cerebral Blood ◽  
Generating Functional ◽  
In Vivo Measurement ◽  
A Value ◽  
Cerebral Grey Matter ◽  
Washout Phase ◽  
A Minor

The present study was undertaken to determine the apparent value for the volume of distribution of water to be used in the dynamic/integral technique for generating functional CBF images. A value of 0.86 resulted in only a minor loss of accuracy compared to the more accurate (but time-consuming) dynamic only analysis, which incorporated the regionally fitted estimates of the volume of distribution of water. In contrast to the traditionally used in vitro value of 0.95, the value of 0.86 allows for the inclusion of a significant part of the washout phase in the integral analysis, thereby producing statistically improved CBF images.

scholarly journals Characterization of the SARS-CoV-2 coronavirus X4-like accessory protein

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Olanrewaju Ayodeji Durojaye ◽  
Nkwachukwu Oziamara Okoro ◽  
Arome Solomon Odiba
Keyword(s):  
Rapid Development ◽  
Protein A ◽  
The Novel ◽  
Quality Model ◽  
A Value ◽  
Model Protein ◽  
Novel Coronavirus ◽  
Global Threat

Abstract Background The novel coronavirus SARS-CoV-2 is currently a global threat to health and economies. Therapeutics and vaccines are in rapid development; however, none of these therapeutics are considered as absolute cure, and the potential to mutate makes it necessary to find therapeutics that target a highly conserved regions of the viral structure. Results In this study, we characterized an essential but poorly understood coronavirus accessory X4 protein, a core and stable component of the SARS-CoV family. Sequence analysis shows a conserved ~ 90% identity between the SARS-CoV-2 and previously characterized X4 protein in the database. QMEAN Z score of the model protein shows a value of around 0.5, within the acceptable range 0–1. A MolProbity score of 2.96 was obtained for the model protein and indicates a good quality model. The model has Ramachandran values of φ = − 57o and ψ = − 47o for α-helices and values of φ = − 130o and ψ = + 140o for twisted sheets. Conclusions The protein data obtained from this study provides robust information for further in vitro and in vivo experiment, targeted at devising therapeutics against the virus. Phylogenetic analysis further supports previous evidence that the SARS-CoV-2 is positioned with the SL-CoVZC45, BtRs-BetaCoV/YN2018B and the RS4231 Bat SARS-like corona viruses.

Effects of hypercapnia on ECoG and oxidative metabolism in neonatal dog brain

1995 ◽  
Vol 78 (6) ◽  
pp. 2272-2278 ◽  
Author(s):  
H. Yoshioka ◽  
H. Miyake ◽  
D. S. Smith ◽  
B. Chance ◽  
T. Sawada ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Resonance Spectroscopy ◽  
Respiratory Enzymes ◽  
Arterial Pco2 ◽  
A Value ◽  
Electrocorticogram Ecog ◽  
The Brain ◽  
Mitochondrial Respiratory

The effects of hypercapnia on cerebral electrical activity and mitochondrial oxidative phosphorylation were studied in the anesthetized neonatal dog by using the electrocorticogram (ECoG) and 31P-magnetic resonance spectroscopy. Three levels of hypercapnia with arterial PCO2 values of approximately 70, 100, and 140 Torr reduced the intracellular pH of the brain from 7.11 to 6.99, 6.87, and 6.76, respectively. These levels of hypercapnia also reduced ADP concentration ([ADP]) from 21.5 to 18.1, 14.8, and 12.9 microM as well as the average ECoG power output by 20, 30, and 40%. A Michaelis-Menten relationship for the mitochondrial respiratory enzymes was fitted with [ADP] and the change in the average ECoG. The result suggests that mitochondrial respiration is regulated by [ADP] and that the in vivo Michaelis-Menten constant for ADP was 21 microM, a value close to the in vitro value. The mitochondrial maximal reaction velocity was reduced by only 10% during hypercapnia and showed no relationship with the degree of acidosis, suggesting that mitochondrial respiratory enzymes are not responsible for the inhibition of the brain electrical activity.

scholarly journals In vivo measurement of intrauterine pressure by telemetry: a new approach for studying parturition in mouse models

2010 ◽  
Vol 42 (2) ◽  
pp. 310-316 ◽  
Author(s):  
Stephanie L. Pierce ◽  
William Kutschke ◽  
Rafael Cabeza ◽  
Sarah K. England
Keyword(s):  
Mouse Models ◽  
Accurate Method ◽  
Isometric Tension ◽  
Mouse Uterus ◽  
New Approach ◽  
In Vivo Measurement ◽  
Intrauterine Pressure

Transgenic and knockout mouse models have proven useful in the study of genes necessary for parturition—including genes that affect the timing and/or progression of labor contractions. However, taking full advantage of these models will require a detailed characterization of the contractile patterns in the mouse uterus. Currently the best methodology for this has been measurement of isometric tension in isolated muscle strips in vitro. However, this methodology does not provide a real-time measure of changes in uterine pressure over the course of pregnancy. Recent advances have opened the possibility of using radiotelemetric devices to more accurately and comprehensively study intrauterine pressure in vivo. We tested the effectiveness of this technology in the mouse, in both wild-type (WT) mice and a mouse model of defective parturition (SK3 channel-overexpressing mice), after surgical implant of telemetry transmitters into the uterine horn. Continuous recordings from day 18 of pregnancy through delivery revealed that WT mice typically deliver during the 12-h dark cycle after 19.5 days postcoitum. In these mice, intrauterine pressure gradually increases during this cycle, to threefold greater than that measured during the 12-h cycle before delivery. SK3-overexpressing mice, by contrast, exhibited lower intrauterine pressure over the same period. These results are consistent with the outcome of previous in vitro studies, and they indicate that telemetry is an accurate method for measuring uterine contraction, and hence parturition, in mice. The use of this technology will lead to important novel insights into changes in intrauterine pressure during the course of pregnancy.

scholarly journals Effect of hepatocyte-stimulating factor and glucocorticoids on plasma fibronectin levels

1986 ◽  
Vol 238 (2) ◽  
pp. 365-371 ◽  
Author(s):  
D L Amrani ◽  
D Mauzy-Melitz ◽  
M W Mosesson
Keyword(s):  
Acute Phase Protein ◽  
Plasma Fibronectin ◽  
Phagocytic Cells ◽  
Serum Samples ◽  
Exclusion Chromatography ◽  
A Minor ◽  
Two Peaks ◽  
Stimulating Factor

We evaluated the effects of hepatocyte-stimulating factor (HSF) and a glucocorticoid (dexamethasone) on changes in the levels, in vivo and in vitro, of plasma fibronectin (Fn), a glycoprotein that is synthesized and secreted by hepatocytes. In turpentine-treated chickens, plasma levels of Fn, which peaked at 48 h (whereas fibrinogen levels were maximum at 72 h) rose 200-250% over basal levels, whereas albumin levels decreased by 20-40%. Corticosterone levels in serum samples taken between 5 and 48 h after injection revealed a 124% increase in hormone levels at 24 h in turpentine-treated chickens. We also showed that circulating HSF levels were maximal 8 to 12 h after injection and that HSF activity, as assessed by molecular-exclusion chromatography, was eluted in the 30-45 kDa range. Addition of either serum-derived HSF or dexamethasone (2 nM) to chick hepatocyte cultures resulted in a 130-150% increase in secreted Fn as well as in fibrinogen. When HSF and dexamethasone were added together, a 360-489% increase in the secreted levels of both proteins was found. Chicken mononuclear phagocytic cells treated with lipopolysaccharide secreted an HSF activity that was eluted in two peaks, a minor peak at approximately 70 kDa and a major peak in the 25-40 kDa range. Addition of mononuclear-cell-derived HSF resulted in a greater increase in Fn levels than did the addition of serum HSF. These findings indicate that Fn, like fibrinogen, is an acute-phase protein, the production of which, at least in chickens, is stimulated by HSF and glucocorticoids in an additive manner.

Measurement of the Optical Properties of Muscle Tissue In Vivo

2000 ◽  
Author(s):  
P. L. Kopsombut ◽  
D. Willis ◽  
A. E. Schen ◽  
L. X. Xu ◽  
X. Xu
Keyword(s):  
Optical Properties ◽  
Transport Theory ◽  
Rapid Development ◽  
Ccd Camera ◽  
High Sensitivity ◽  
Biological Tissues ◽  
In Vivo Measurement ◽  
Living Tissues

Abstract Along with rapid development of diagnostic and therapeutic applications of lasers in medicine, optical properties of various biological tissues have been extensively studied [1]. Most of the studies were performed in vitro owing to the complexity involved in in vivo measurement. To date, it is well understood that living tissue is an absorbing and scattering heterogeneous medium because of its complex structures including blood network. The transport theory cannot be readily used due to the heterogeneity and the absence of the optical properties of living tissues [2]. In this research, we have developed a procedure for measuring the total attenuation coefficient (μ1) of the exteriorized rat 2-D spinotrapezius muscle in the wavelength ranged from 480–560 nm using the collimated light from a Nitrogen-pumped dye laser and a high-sensitivity CCD camera.

New Diagnostic and Monitoring Method for Osteoporosis

2017 ◽  
pp. 1851-1884
Author(s):  
Sofia Panteliou
Keyword(s):  
Bone Quality ◽  
Structural Integrity ◽  
Assessment Tool ◽  
Bone Diseases ◽  
Damping Factor ◽  
In Vivo Measurement ◽  
Modal Damping ◽  
Invasive Method

Osteoporosis is chronic disease affecting most postmenopausal females and 30% of males with biological, behavioral and financial consequences. A non invasive method to assess bone structural integrity is presented, based on in-vitro or in-vivo measurement of bone dynamic characteristics (Modal Damping Factor) by applying vibration excitation in the range of acoustic frequencies, in the form of an acoustic sweep signal. This method has been applied on metallic structures and composites, including bones, and is supported by analytical and arithmetic tool based on model's theory. Experimental MDF results are compared to results acquired with conventional methods for bone quality assessment and show impressive correlations between damping factor and indices of bone quality in an advantageous manner. Evaluation of these research findings strengthens the potential of the proposed method to consist a valuable assessment tool for diagnosis and monitoring of bone integrity, in metabolic bone diseases, especially osteoporosis.

scholarly journals Blockade of STAT3 Causes Severe In Vitro and In Vivo Maturation Defects in Intestinal Organoids Derived from Human Embryonic Stem Cells

2019 ◽  
Vol 8 (7) ◽  
pp. 976 ◽  
Author(s):  
Kwang Bo Jung ◽  
Ohman Kwon ◽  
Mi-Ok Lee ◽  
Hana Lee ◽  
Ye Seul Son ◽  
...  
Keyword(s):  
Stem Cells ◽  
Human Embryonic Stem Cell ◽  
In Vitro Maturation ◽  
Embryonic Stem ◽  
Generating Functional ◽  
Intestinal Maturation ◽  
Intestinal Organoids ◽  
Hesc Lines

Human intestinal organoids (hIOs), which resemble the human intestine structurally and physiologically, have emerged as a new modality for the study of the molecular and cellular biology of the intestine in vitro. We recently developed an in vitro maturation technique for generating functional hIOs from human pluripotent stem cells (hPSCs). Here, we investigated the function of STAT3 for inducing in vitro maturation of hIOs. This was accompanied by the tyrosine phosphorylation of STAT3, whereas treatment with pharmacological inhibitors of STAT3 suppressed the phosphorylation of STAT3 and the expression of intestinal maturation markers. We generated and characterized STAT3 knockout (KO) human embryonic stem cell (hESC) lines using CRISPR/Cas9-mediated gene editing. We found that STAT3 KO does not affect the differentiation of hESCs into hIOs but rather affects the in vitro maturation of hIOs. STAT3 KO hIOs displayed immature morphologies with decreased size and reduced budding in hIOs even after in vitro maturation. STAT3 KO hIOs showed markedly different profiles from hIOs matured in vitro and human small intestine. Additionally, STAT3 KO hIOs failed to maintain upon in vivo transplantation. This study reveals a core signaling pathway consisting of STAT3 controlling the in vitro maturation of hIOs derived from hPSCs.

scholarly journals Involvement of 27-Hydroxycholesterol in Mitotane Action on Adrenocortical Carcinoma

Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 885
Author(s):  
Antonina Germano ◽  
Daniela Rossin ◽  
Valerio Leoni ◽  
Noemi Iaia ◽  
Laura Saba ◽  
...  
Keyword(s):  
Adrenocortical Carcinoma ◽  
Cholesterol Metabolism ◽  
Cell Model ◽  
Gas Chromatography Mass Spectrometry ◽  
Strong Increase ◽  
Vitro Model ◽  
A Minor ◽  
Cholesterol Precursors

Adrenocortical carcinoma (ACC) is a rare cancer with poor prognosis. Mitotane, the standard treatment for ACC, impairs adrenocortical steroid biosynthesis and cholesterol metabolism. In the H295R cell line, a standard ACC in vitro model, mitotane was previously reported to enhance the production of some oxysterols. To verify the possible mechanistic involvement of oxysterols in the anti-ACC effect of mitotane, a gas chromatography mass spectrometry (GC-MS) profiling of oxysterols and the main cholesterol precursors was carried out in H295R cells. Among the oxysterols detected in mitotane-treated cells, 27OHC was markedly produced, as well as lanosterol and lathosterol cholesterol precursors. In this cell model, mitotane was confirmed to affect mitochondrial transmembrane potential and induce apoptosis. Such cytotoxic effects were perfectly matched by H295R cell treatment with a single identical micromolar amount of 27OHC. The mitotane-dependent strong increase in 27OHC was confirmed in vivo, in the plasma of ACC patients under treatment with the drug. Moreover, lanosterol, lathosterol, desmosterol and, to a minor extent, 24-hydroxycholesterol and 25-hydroxycholesterol plasma levels were significantly increased in those patients. The cytotoxic effect of mitotane on ACC cells may be partly related to the increased intracellular level of 27OHC induced by the drug itself.

Sign in / Sign up

Export Citation Format

Share Document