STEROID METABOLISM IN THE PERFUSED HUMAN PLACENTA

1978 ◽  
Vol 87 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Alfred S. Wolf ◽  
Klaus A. Musch ◽  
Werner Speidel ◽  
Jürgen R. Strecker ◽  
Christian Lauritzen
Keyword(s):  
Venous Blood ◽  
Placental Lactogen ◽  
Dehydroepiandrosterone Sulphate ◽  
Metabolic Capacity ◽  
Loading Test ◽  
Lower Range ◽  
Group I ◽  
High Concentrations ◽  
Steroid Precursor

ABSTRACT A new model for the perfusion of human term-placentas has been developed for studies on the placental biogenesis of C-18 and C-19 steroids. For viability criteria, the glucose- and oxygen-consumption, regional perfusion control by dye-infusions or scanning after injection of 99Tc-labelled macroparticles, and the histological qualification were chosen. The recycled perfusate was investigated for the steroids oestrone (Oe1), oestradiol-17β (Oe2), oestriol (Oe3), 4-androstene-3,17-dione (A), testosterone (T), and human placental lactogen (HPL) by radioimmunoassay in controls and perfusions with the foetal steroid precursor dehydroepiandrosterone sulphate (DHA-S). In control perfusions, steroid hormones were found in constant ratios (Oe1:Oe2:Oe3:T:A = 30:1.5:100:0.35:1). Following the administration of 10 mg DHA-S for testing the metabolic capacity of the organ, high concentrations of Oe1 (90–720 ng/ml = 250–3970 % as compared to 100% pre-injection values) were found, shortly preceded by a rapid increase of A (66–1000 ng/ml = 100–16 000 %). A typical surge of T (5.3–147 ng/ml = 265–4640 %) preceded the normally slower increment of Oe2 (22–220 ng/ml = 1570–4330 %). The concentrations of Oe3 and HPL remained nearly unchanged. From different steroid patterns after DHA-S-load, two distinct responses of term-placentas could be differentiated: Group I (n=12) showed high concentrations of Oe1 (3200 ± 940 %), a small increase of T (1020 ± 500%), as well as low and delayed values of Oe2 (1660 ± 450%). In Group II (n = 5), values were high for T (3160 ± 1020%) and Oe2 (3300 ± 1110%), whereas Oe1 was found in a lower range (508 ± 302%). In contrast to in vivo findings in maternal venous blood after DHS-S injection to the mother, oestrone was found in perfusions as the main oestrogen fraction from DHA-S. Thus, the analysis of such metabolic differences might be of help in the interpretation of complex results from the DHA-S-loading test.

scholarly journals Extracellular HMGB1: a therapeutic target in severe pulmonary inflammation including COVID-19?

2020 ◽  
Vol 26 (1) ◽  
Author(s):  
Ulf Andersson ◽  
William Ottestad ◽  
Kevin J. Tracey
Keyword(s):  
Therapeutic Target ◽  
Pulmonary Inflammation ◽  
Venous Blood ◽  
Extracellular Dna ◽  
Inflammasome Activation ◽  
Molecular Pattern ◽  
High Concentrations ◽  
Novel Coronavirus ◽  
Dying Cells

Abstract Background The 2019 novel coronavirus disease (COVID-19) causes for unresolved reasons acute respiratory distress syndrome in vulnerable individuals. There is a need to identify key pathogenic molecules in COVID-19-associated inflammation attainable to target with existing therapeutic compounds. The endogenous damage-associated molecular pattern (DAMP) molecule HMGB1 initiates inflammation via two separate pathways. Disulfide-HMGB1 triggers TLR4 receptors generating pro-inflammatory cytokine release. Extracellular HMGB1, released from dying cells or secreted by activated innate immunity cells, forms complexes with extracellular DNA, RNA and other DAMP or pathogen-associated molecular (DAMP) molecules released after lytic cell death. These complexes are endocytosed via RAGE, constitutively expressed at high levels in the lungs only, and transported to the endolysosomal system, which is disrupted by HMGB1 at high concentrations. Danger molecules thus get access to cytosolic proinflammatory receptors instigating inflammasome activation. It is conceivable that extracellular SARS-CoV-2 RNA may reach the cellular cytosol via HMGB1-assisted transfer combined with lysosome leakage. Extracellular HMGB1 generally exists in vivo bound to other molecules, including PAMPs and DAMPs. It is plausible that these complexes are specifically removed in the lungs revealed by a 40% reduction of HMGB1 plasma levels in arterial versus venous blood. Abundant pulmonary RAGE expression enables endocytosis of danger molecules to be destroyed in the lysosomes at physiological HMGB1 levels, but causing detrimental inflammasome activation at high levels. Stress induces apoptosis in pulmonary endothelial cells from females but necrosis in cells from males. Conclusion Based on these observations we propose extracellular HMGB1 to be considered as a therapeutic target for COVID-19.

Iron-mediated radical reactions upon reperfusion contribute to myocardial "stunning"

1990 ◽  
Vol 259 (6) ◽  
pp. H1901-H1911 ◽  
Author(s):  
R. Bolli ◽  
B. S. Patel ◽  
M. O. Jeroudi ◽  
X. Y. Li ◽  
J. F. Triana ◽  
...  
Keyword(s):  
Free Radical ◽  
Myocardial Stunning ◽  
Time Window ◽  
Contractile Function ◽  
Myocardial Dysfunction ◽  
Venous Blood ◽  
Radical Reactions ◽  
Free Radical Reactions ◽  
Group I

Recent evidence suggests that postischemic myocardial dysfunction ("stunning") is mediated by iron-catalyzed free radical reactions, but the exact time window during which the critical iron-mediated damage develops remains unknown. Furthermore, the evidence that iron promotes free radical reactions in vivo is indirect. Thus open-chest dogs undergoing a 15-min coronary occlusion and 4 h of reperfusion were given one of the following intracoronary infusions: desferrioxamine (DF) beginning 2 min before reperfusion (group I), DF beginning 1 min after reperfusion (group II), iron-loaded DF in dosage identical to group I (group III), or vehicle (controls, group IV). Recovery of contractile function was substantially greater in group I than in controls, whereas in groups II and III it was indistinguishable from controls. To determine whether the protection afforded by DF was due to inhibition of free radical reactions, myocardial production of free radicals was directly assessed by intracoronary infusion of the spin trap alpha-phenyl N-tert-butyl nitrone (PBN). In controls (group VI), radical adducts of PBN were released in the coronary venous blood after reperfusion. DF given as in group I (group V) markedly suppressed myocardial production of PBN adducts. These results strongly suggest that a substantial portion of the damage responsible for myocardial stunning is caused by iron-catalyzed free radical reactions that develop in the initial seconds of reperfusion and can be prevented by administration of iron chelators started just before reflow. Furthermore, the results demonstrate that attenuation of postischemic dysfunction by DF is associated with attenuation of free radical reactions in vivo, thereby providing direct evidence for a pathogenetic role of iron-catalyzed free radical reactions in myocardial stunning in the intact animal.

Hair cell changes after cationic stimulation of corti's organ

1989 ◽  
Vol 47 ◽  
pp. 798-799
Author(s):  
Cesar D. Fermin ◽  
Hans-Peter Zenner
Keyword(s):  
Organ Of Corti ◽  
Cross Sectional ◽  
Surface Areas ◽  
High K ◽  
Anatomical Arrangement ◽  
Cell Cytosol ◽  
High Concentrations ◽  
K Concentration ◽  
Cell Changes

Contraction of outer and inner hair cells (OHC&IHC) in the Organ of Corti (OC) of the inner ear is necessary for sound transduction. Getting at HC in vivo preparations is difficult. Thus, isolated HCs have been used to study OHC properties. Even though viability has been shown in isolated (iOHC) preparations by good responses to current and cationic stimulation, the contribution of adjoining cells can not be explained with iOHC preparations. This study was undertaken to examine changes in the OHC after expossure of the OHC to high concentrations of potassium (K) and sodium (Na), by carefully immersing the OC in either artifical endolymph or perilymph. After K and Na exposure, OCs were fixed with 3% glutaraldehyde, post-fixed in osmium, separated into base, middle and apex and embedded in Araldite™. One μm thick sections were prepared for analysis with the light and E.M. Cross sectional areas were measured with Bioquant™ software.Potassium and sodium both cause isolated guinea pig OHC to contract. In vivo high K concentration may cause uncontrolled and sustained contractions that could contribute to Meniere's disease. The behavior of OHC in the vivo setting might be very different from that of iOHC. We show here changes of the cell cytosol and cisterns caused by K and Na to OHC in situs. The table below shows results from cross sectional area measurements of OHC from OC that were exposed to either K or Na. As one would expect, from the anatomical arrangement of the OC, OHC#l that are supported by rigid tissue would probably be displaced (move) less than those OHC located away from the pillar. Surprisingly, cells in the middle turn of the cochlea changed their surface areas more than those at either end of the cochlea. Moreover, changes in surface area do not seem to differ between K and Na treated OCs.

Effects of Rest and Exercise on Cardiac Blood Volume Determinations

1997 ◽  
Vol 36 (08) ◽  
pp. 259-264
Author(s):  
N. Topuzović
Keyword(s):  
Radionuclide Ventriculography ◽  
Left Ventricular ◽  
Peak Exercise ◽  
Volume Determination ◽  
Group I ◽  
Lv Volumes ◽  
Group Ii ◽  
Lv Volume

Summary Aim: The purpose of this study was to investigate the changes in blood activity during rest, exercise and recovery, and to assess its influence on left ventricular (LV) volume determination using the count-based method requiring blood sampling. Methods: Forty-four patients underwent rest-stress radionuclide ventriculography; Tc-99m-human serum albumin was used in 13 patients (Group I), red blood cells was labeled using Tc-99m in 17 patients (Group II) in vivo, and in 14 patients (Group III) by modified in vivo/in vitro method. LV volumes were determined by a count-based method using corrected count rate in blood samples obtained during rest, peak exercise and after recovery. Results: In group I at stress, the blood activity decreased by 12.6 ± 5.4%, p <0.05, as compared to the rest level, and increased by 25.1 ± 6.4%, p <0.001, and 12.8 ± 4.5%, p <0.05, above the resting level in group II and III, respectively. This had profound effects on LV volume determinations if only one rest blood aliquot was used: during exercise, the LV volumes significantly decreased by 22.1 ± 9.6%, p <0.05, in group I, whereas in groups II and III it was significantly overestimated by 32.1 ± 10.3%, p <0.001, and 10.7 ± 6.4%, p <0.05, respectively. The changes in blood activity between stress and recovery were not significantly different for any of the groups. Conclusion: The use of only a single blood sample as volume aliquot at rest in rest-stress studies leads to erroneous estimation of cardiac volumes due to significant changes in blood radioactivity during exercise and recovery.

A P-Selectin/CD62P Monoclonal Antibody (LYP-20), in Tandem with Flow Cytometry, Detects in vivo Activated Circulating Rat Platelets in Severe Vascular Trauma

1994 ◽  
Vol 72 (05) ◽  
pp. 745-749 ◽  
Author(s):  
Elza Chignier ◽  
Maud Parise ◽  
Lilian McGregor ◽  
Caroline Delabre ◽  
Sylvie Faucompret ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Flow Cytometry ◽  
Platelet Activation ◽  
Peripheral Blood ◽  
Vascular Trauma ◽  
Activated Platelets ◽  
Group I ◽  
Group Ii ◽  
Rat Platelets

SummaryP-selectin, also known as CD62P, GMP140 or PADGEM, is present in platelet a-granules and endothelial cell Weibel-Palade bodies and is very rapidly expressed on the surface of these cells on activation. In this study, an anti P-selectin monoclonal antibody (LYP20) was used, in tandem with flow cytometry, to identify activated platelets at the site of induced vascular trauma or in peripheral blood. Moreover, electron microscopy was performed to characterize sites of vascular trauma and quantify the number of adhering platelets. The same induced vascular trauma was observed to result into animals responding in 2 different ways (Group I, Group II) following the degree of platelet activation. Five rats, out of 14 with induced vascular trauma, had more than half of their circulating platelets expressing P-selectin when drawn at the site of the trauma (67.4% ± 3.44) or in peripheral blood (78.5% ± 2.5) (Group I). In the remaining 9 animals a much smaller proportion of circulating platelets expressed P-selectin when assayed from trauma sites (18% ± 3.34) or in peripheral blood (18.0% ± 4.30) (Group II). Enhanced P-selectin expression by circulating platelets in Group I, compared to Group II, appears to be linked to the degree of activated platelets adhering at sites of trauma (171 ± 15 × 103 platelets versus 48 ± 31 × 103 platelets per mm2). In the 5 control animals, that were not operated on, platelets expressing P-selectin when drawn at the site of a mock trauma (7.0% ± 1.84) or in the peripheral blood (11.2% ± 3.30) showed little activation. In addition, no platelet adhesion was seen on the vascular bed of these animals. Results from this study show that analysis of P-selectin (CD62P) expression, in circulating platelets, is a valuable and rapid marker of platelet activation following severe vascular trauma induced in rats. However, activated platelets were not detected to the same extent in the peripheral blood of all animals having undergone vascular trauma. It is conceivable that platelets, depending on the degree of activation, may be actively sequestered in organs and prevented from circulating. Alternatively, P-selectin may be rapidly endocytosed, or not expressed, by activated circulating platelets depending on the type of agonists implicated in vivo activation.

(Preprint)

2018 ◽  
Author(s):  
Dr Malathi Dayalan ◽  
Dr Sudeshna Sharma ◽  
Dr Shweta Poovani ◽  
Dr Saher Altaf
Keyword(s):  
Myofascial Pain ◽  
Mouth Opening ◽  
Masticatory Muscles ◽  
Matched Pair ◽  
Masticatory Muscle ◽  
Muscle Disorders ◽  
Occlusal Contact ◽  
Group I ◽  
Group Ii

BACKGROUND Masticatory system is a complex functional unit, primarily engaged in chewing, swallowing and breathing functions, and some parts are involved in taste recognition and determination of food consistency. Sophisticated functional performances of speech and emotional expressions are specifically human qualities. Irregularities in occlusion appears to be the precipitating factor in the pathogenesis of myofascial pain dysfunction syndrome. Tek- Scan III records the bite length, number, distribution, timing, duration and the relative force of each tooth contact. It also records the sequence of occlusal contacts in terms of time and the associated force with each occlusal contact. The aim of this study was to treat masticatory muscle disorders with occlusal equilibration, and compare the efficacy of treatment outcomes between selective grinding and stabilization splints using Tek-Scan III. OBJECTIVE Objective of this study was to compare the efficacy of occlusal equilibration achieved through selective griding and stabilization splints using Tek-Scan III. METHODS In this in vivo study, 40 patients with masticatory muscle disorders were selected based on the inclusion and exclusion criteria. The occlusal discrepancies were analyzed using Tek-Scan III. The selected 40 subjects were then randomly divided into 2 groups based on the treatment they recieved; Group I – Selective grinding group (20) and Group II – Stabilization splint group (20). Comparison of pre-treatment and post treatment results were evaluated in terms of pain, mouth opening, left and right side force percentage as recorded through Tek-Scan III and reduction of disclusion time. Statistical analysis was carried out with Kolmogorov Smirnov test, Wilcoxon matched pair test and Mann-Whitney U test. RESULTS Wilcoxon matched pairs test demonstrated that there was statistically significant results ( p = 0.0007) in both the groups for reduction of disclusion time, elimination of pain and improved mouth opening. Patients in Group I showed better results as compared to Group II in terms of disclusion time, pain and mouth opening. CONCLUSIONS Occlusal equilibration brought about by reducing the disclusion time using the Tek- Scan III reduced the symptoms of pain in masticatory muscles. Patients in group I (Selective grinding) however showed better results when compared to patients in group II (Stabilization splints).

scholarly journals Enterococcus faecalis exploits the human fibrinolytic system to drive excess collagenolysis: implications in gut healing and identification of druggable targets

2020 ◽  
Vol 318 (1) ◽  
pp. G1-G9 ◽  
Author(s):  
Richard A. Jacobson ◽  
Kiedo Wienholts ◽  
Ashley J. Williamson ◽  
Sara Gaines ◽  
Sanjiv Hyoju ◽  
...  
Keyword(s):  
Enterococcus Faecalis ◽  
Healing Process ◽  
Abdominal Sepsis ◽  
Infectious Complications ◽  
Fibrinolytic System ◽  
Clinical Safety ◽  
High Concentrations ◽  
Clinically Significant

Perforations, anastomotic leak, and subsequent intra-abdominal sepsis are among the most common and feared complications of invasive interventions in the colon and remaining intestinal tract. During physiological healing, tissue protease activity is finely orchestrated to maintain the strength and integrity of the submucosa collagen layer in the wound. We (Shogan, BD et al. Sci Trans Med 7: 286ra68, 2015.) have previously demonstrated in both mice and humans that the commensal microbe Enterococcus faecalis selectively colonizes wounded colonic tissues and disrupts the healing process by amplifying collagenolytic matrix-metalloprotease activity toward excessive degradation. Here, we demonstrate for the first time, to our knowledge, a novel collagenolytic virulence mechanism by which E. faecalis is able to bind and locally activate the human fibrinolytic protease plasminogen (PLG), a protein present in high concentrations in healing colonic tissue. E. faecalis-mediated PLG activation leads to supraphysiological collagen degradation; in this study, we demonstrate this concept both in vitro and in vivo. This pathoadaptive response can be mitigated with the PLG inhibitor tranexamic acid (TXA) in a fashion that prevents clinically significant complications in validated murine models of both E. faecalis- and Pseudomonas aeruginosa-mediated colonic perforation. TXA has a proven clinical safety record and is Food and Drug Administration approved for topical application in invasive procedures, albeit for the prevention of bleeding rather than infection. As such, the novel pharmacological effect described in this study may be translatable to clinical trials for the prevention of infectious complications in colonic healing. NEW & NOTEWORTHY This paper presents a novel mechanism for virulence in a commensal gut microbe that exploits the human fibrinolytic system and its principle protease, plasminogen. This mechanism is targetable by safe and effective nonantibiotic small molecules for the prevention of infectious complications in the healing gut.

scholarly journals Functional expression, quantification and cellular localization of the Hxt2 hexose transporter of Saccharomyces cerevisiae tagged with the green fluorescent protein

1999 ◽  
Vol 339 (2) ◽  
pp. 299-307 ◽  
Author(s):  
Arthur L. KRUCKEBERG ◽  
Ling YE ◽  
Jan A. BERDEN ◽  
Karel van DAM
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Green Fluorescent Protein ◽  
Glucose Transport ◽  
Cellular Localization ◽  
Fluorescent Protein ◽  
Hexose Transporter ◽  
High Concentrations ◽  
Green Fluorescent

The Hxt2 glucose transport protein of Saccharomyces cerevisiae was genetically fused at its C-terminus with the green fluorescent protein (GFP). The Hxt2-GFP fusion protein is a functional hexose transporter: it restored growth on glucose to a strain bearing null mutations in the hexose transporter genes GAL2 and HXT1 to HXT7. Furthermore, its glucose transport activity in this null strain was not markedly different from that of the wild-type Hxt2 protein. We calculated from the fluorescence level and transport kinetics that induced cells had 1.4×105 Hxt2-GFP molecules per cell, and that the catalytic-centre activity of the Hxt2-GFP molecule in vivo is 53 s-1 at 30 °C. Expression of Hxt2-GFP was induced by growth at low concentrations of glucose. Under inducing conditions the Hxt2-GFP fluorescence was localized to the plasma membrane. In a strain impaired in the fusion of secretory vesicles with the plasma membrane, the fluorescence accumulated in the cytoplasm. When induced cells were treated with high concentrations of glucose, the fluorescence was redistributed to the vacuole within 4 h. When endocytosis was genetically blocked, the fluorescence remained in the plasma membrane after treatment with high concentrations of glucose.

scholarly journals Collagen-Based Electrospun Materials for Tissue Engineering: A Systematic Review

2021 ◽  
Vol 8 (3) ◽  
pp. 39
Author(s):  
Britani N. Blackstone ◽  
Summer C. Gallentine ◽  
Heather M. Powell
Keyword(s):  
Systematic Review ◽  
Tissue Engineering ◽  
Collagen Type I ◽  
The Body ◽  
Pool Data ◽  
Type I ◽  
High Concentrations ◽  
Increased Strength

Collagen is a key component of the extracellular matrix (ECM) in organs and tissues throughout the body and is used for many tissue engineering applications. Electrospinning of collagen can produce scaffolds in a wide variety of shapes, fiber diameters and porosities to match that of the native ECM. This systematic review aims to pool data from available manuscripts on electrospun collagen and tissue engineering to provide insight into the connection between source material, solvent, crosslinking method and functional outcomes. D-banding was most often observed in electrospun collagen formed using collagen type I isolated from calfskin, often isolated within the laboratory, with short solution solubilization times. All physical and chemical methods of crosslinking utilized imparted resistance to degradation and increased strength. Cytotoxicity was observed at high concentrations of crosslinking agents and when abbreviated rinsing protocols were utilized. Collagen and collagen-based scaffolds were capable of forming engineered tissues in vitro and in vivo with high similarity to the native structures.

scholarly journals Effects of bisphosphonate and calcium carbonate on normal aortic valve and cholecalciferol induced in vivo rabbit aortic stenosis model

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Okutucu ◽  
C Sabanoglu ◽  
A Saglam Ayhan ◽  
E Tulumen ◽  
H Aksoy ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Aortic Valve ◽  
Aortic Stenosis ◽  
Calcium Supplementation ◽  
Group Iv ◽  
Histopathologic Examination ◽  
Group V ◽  
Group I ◽  
Alendronate Treatment

Abstract Background Calcific aortic valve disease (CAVD) is the most common valvular heart disease. Bisphosphonates are stable analogs of pyrophosphates and commonly prescribed in the treatment of osteoporosis. The effects of bisphosphonate treatment on CAVD are not clearly known and there are inconsistent results. Similarly, the effect of calcium supplementation on CAVD remains controversial. Purpose The aim of this study was to assess the effects of bisphosphonate therapy on the normal aortic valve and vitamin D induced in vivo rabbit aortic stenosis (AS) model. Methods The impact of calcium supplementation on the rabbit AS model was also evaluated. A total of 30 New Zealand white rabbits were divided into five equal groups: no treatment (Group I); 25,000 IU/day vitamin D3 (cholecalciferol) (Group II, rabbit AS model); 25,000 IU/day cholecalciferol plus 2500 mg/day calcium carbonate (Group III); 20 μg/kg/week intravenous alendronate (Group IV) and 25,000 IU/day cholecalciferol plus 2500 mg/day calcium carbonate plus 20μg/kg/week alendronate (Group V). Echocardiography was performed at baseline and after 12 weeks of treatment. The left ventricular mass index (LVMI), aortic valve area (AVA), transvalvular velocities and gradients were recorded. Radiologic and histopathologic examination was performed at the end of the 12th week. Control animals displayed no abnormalities of the aortic valve. Results There was no echocardiographic change in Group IV. In Groups II, III and V, there was a significant decrease in AVA and increases in transvalvular velocities and gradients. However, these stenotic changes were significantly prominent in Group V (p=0.001 for all, via repeated measures ANOVA). Moreover, LVMI was only increased in Group V (p&lt;0.05). Calcification of aortic valvar complex was detected in 14 (46.7%) cases by radiologic imaging and 10 (33.3%) cases by histopathologic examination. Most frequent calcification was found in Group V (5 for each method, 83.3%). Agatston, volume and equivalent mass scores of calcific foci in Group V were significantly higher than other groups (p&lt;0.05 for all). There was no significant difference between groups regarding with presence of osteoclasts in calcific foci. Conclusion Calcium supplementation has no effect on the in vivo rabbit AS model. Alendronate treatment aggravates the stenosis and increases the calcification in the rabbit AS model. Alendronate treatment has no effect on the normal valve in which there was no osteogenesis and osteoclastogenesis. Based on these findings, in patients with CAVD, alendronate treatment should be given with regular echocardiographic follow-up or may not be preferred. Central figure Funding Acknowledgement Type of funding source: None

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