TY - JOUR. T1 - E-selectin and very late activation antigen-4 mediate adhesion of hematopoietic progenitor cells to bone marrow endothelium. AU - Rood, P. M L. AU - Dercksen, M. W.. AU - Cazemier, H.. AU - Kerst, J. M.. AU - Von dem Borne, A. E G K. AU - Gerritsen, W. R.. AU - Van der Schoot, C. E.. PY - 2000. Y1 - 2000. N2 - Adhesion of CD34 + hematopoietic progenitor cells (HPCs) to sinusoidal endothelium probably plays a key role in homing of transplanted CD34+ HPCs to the bone marrow (BM). We have investigated the role of various adhesion molecules in the interaction of purified CD34+ HPCs derived from BM or peripheral blood (PB) and a human BM-derived endothelial cell line. Adhesion of CD34+ HPCs to endothelial cells was measured with the use of a double-color flow microfluorimetric adhesion assay. In this assay, adhesion is measured under stirring conditions, simulating blood flow in sinusoidal marrow vessels. Adhesion of PB CD34+ cells to human BM endothelial cells (HBMECs) was observed ...
Distant metastasis, predominantly to bone, is the leading cause of morbidity and mortality in prostate cancer. However, the mechanisms underlying prostate cancer metastases remain unknown. Prostate cancer cells exhibited discrete adhesion to bone marrow endothelial cells (BMEC), resulting in osteotropic metastasis. Prior data showed an increased metastatic propensity of prostate stem cell antigen (PSCA)-positive prostate cancer cells. The current study sought to characterize the roles of PSCA in the adhesion of prostate cancer cells to BMECs. Cell adhesion was assessed using the adhesion assay and transendothelial migration. The expression and regulation of integrins were evaluated by qRT-PCR, Western blot, promoter-luciferase activity, and chromatin immunoprecipitation (ChIP). Functionally, the potential interacting partners of PSCA in prostate cancer cells were identified by coimmunoprecipitation and mass spectrometry (MS) analysis. The association of PSCA expression with bone metastasis was ...
Top 10 tissues for 1005_at (Homo sapiens, Affymetrix Probeset): bone marrow endothelium progenitor cell, blood vessel endothelium cell, bone marrow monocyte, corneal limbus, cornea, band cell, bone marrow polymorphonuclear cell (PMN), peripheral blood transitional stage B-cell (unspecified), blood neutrophil granulocyte, pulmonary (lung) myofibroblast
rolls during the following 0.53 seconds. The white arrow marks the initial site of interaction. Supplemental data of a video depicting the BM intravital microscopy model can be downloaded at http://www.jci.org/cgi/content/full/110/4/559/DC1. Bars in ...
Corneal endothelial cells are found on the inner aspect of the cornea where they secrete a specialized extracellular matrix. They form a very tightly packed monolayer with tight junctions between cells. Our cultured corneal endothelial cells from 2- and 3-day-old calves are cryopreserved passage 3 and have been successfully thawed and subcultured. Type II collagen - a major component of vitreous - can be detected in the culture supernatant. Bovine corneal endothelial cells can be used in studying diseases of the eye. We can provide primary cultures upon request. ...
Dedkova EN, Ji X, Lipsius SL, Blatter LA. Mitochondrial calcium uptake stimulates nitric oxide production in mitochondria of bovine vascular endothelial cells. Am J Physiol Cell Physiol. 2004 Feb; 286(2):C406-15 ...
Human Hepatic Sinusoidal Endothelial Cell Genomic DNA https://www.sciencepro.com.br/produtos/sc-5009 https://www.sciencepro.com.br/@@site-logo/logo-novo.png ...
We use cookies to ensure that we give you the best experience on our website. If you click Continue well assume that you are happy to receive all cookies and you wont see this message again. Click Find out more for information on how to change your cookie settings ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Get Human Endothelial Cells from Primacyt. High purity, low passage, HIV1+2, HAV, HBV, HCV tested. Immediate lot information download.
Dynamic factors account for one third of intrahepatic vascular resistance. Stellate cells serve as contractile cells for adjacent hepatic endothelial cells. The nitric oxide produced by the endothelia... more
Dynamic factors account for one third of intrahepatic vascular resistance. Stellate cells serve as contractile cells for adjacent hepatic endothelial cells. The nitric oxide produced by the endothelia... more
A broader appreciation of the numerous functions of the endothelium can be obtained by study of the levels of molecules of endothelial origin in circulating blood. These include direct products of endothelial cells that change when the endothelium is activated, such as measures of NO biology, inflammatory cytokines, adhesion molecules, regulators of thrombosis, as well as markers of endothelial damage and repair. Many of these circulating markers are difficult and expensive to measure, and currently are only used in the clinical research setting. In this context, these measures can provide important information regarding mechanisms and severity of endothelial dysfunction in populations, and complement physiological tests of endothelial vascular control.61 As a result of biological and assay availability and variability, these factors currently have only a very limited role in the assessment of individual patients.. Circulating levels of nitrites and nitrosylated proteins in part reflect ...
Many of the segmented polyurethanes currently used in cardiovascular prostheses undergo either modification of their surface structure or are lined with a confluent monolayer of endothelial cells to improve their hemocompatibility. During the establishment of an endothelial cell lining on these biop …

Ease of Ang-2 from endothelia is mediated by Tlr4 [13] and we JI 101 site detected mRNA levels of Tlr4 on HUVECs (Figure 6A). Prior studies have shown that
What is the term applied to white blood cells squeezing between endothelial cells lining the blood vessel to reach the site of an infection ...
TY - JOUR. T1 - Corneal endothelial cell analysis using two non-contact specular microscopes in healthy subjects. AU - Garza-Leon, Manuel. PY - 2016/8/1. Y1 - 2016/8/1. N2 - To compare specular microscopy values obtained using the Perseus (CSO, Italy) and the Nidek CEM-530 (NIDEK Co., Ltd. Japan) specular microscopes. This prospective study used specular microscopy to examine sixty eyes from thirty healthy subjects (29.83 ± 9.41 years; range 18-79 years). This was done with both the Nidek CEM-530 and the Perseus on three occasions and results were evaluated by one independent observer. Measurement differences between instruments and agreement between devices were determined. The endothelial cell sample was larger with the Perseus than with the CEM-530 (235.92 ± 38.26 vs. 184.38 ± 43.88, respectively) with a statistically significant difference (P = 0.001). Mean endothelial cell density (ECD) with the Perseus and CEM-530 was 2692.75 ± 306.66 and 2556.47 ± 257.38 cells/mm 2 (P = 0.001), ...
TY - JOUR. T1 - Thrombin-induced gap formation in confluent endothelial cell monolayers in vitro. AU - Laposata, Michael. AU - Dovnarsky, D. K.. AU - Shin, H.. PY - 1983. Y1 - 1983. N2 - When thrombin is incubated with confluent monolayers of human umbilical vein endothelial cells in vitro, there is a change in the shape of the endothelial cells that results in gaps in the monolayer disrupting the integrity of the endothelium and exposing the subendothelium. Using a grid assay to measure this phenomenon, we observed that up to 80% of the surface area once covered by cells was uncovered after a 15-min incubation with 10-2 U/ml (10-10 M) thrombin. The effect was apparent within 2 min and did not remove cells from the surface of the culture dish. The gaps in the monolayer completely disappeared within 2 hr after exposure to thrombin. The effect of thrombin was inhibited by preincubation of thrombin with hirudin or antithrombin III plush heparin or by preincubation of the monolayers with dibutyryl ...
Acetylated low-density lipoprotein (acetyl-LDL), biologically labelled in the cholesterol moiety of cholesteryl oleate, was injected into control and oestrogen-treated rats. The serum clearance, the distribution among the various lipoproteins, the hepatic localization and the biliary secretion of the [3H]cholesterol moiety were determined at various times after injection. In order to monitor the intrahepatic metabolism of the cholesterol esters of acetyl-LDL in vivo, the liver was subdivided into parenchymal, endothelial and Kupffer cells by a low-temperature cell-isolation procedure. In both control and oestrogen-treated rats, acetyl-LDL is rapidly cleared from the circulation, mainly by the liver endothelial cells. Subsequently, the cholesterol esters are hydrolysed, and within 1 h after injection, about 60% of the cell- associated cholesterol is released. The [3H]cholesterol is mainly recovered in the high-density lipoprotein (HDL) range of the serum of control rats, while low levels of ...
In the present study, it is noteworthy that only focal or little immunoreactive vWF was found in the endocardium of noncardiac patients with none of the clinical high-risk predictors for thromboembolism, whereas vWF was apparent in the endothelium of intramyocardial vessels of the same cases. We confirmed that immunoreactivity for other endothelial cell markers, CD31, CD34 and eNOS, was maintained in the endocardial endothelium as well as in the vessel endothelium. Our observations suggest that in noncardiac patients, the endocardial endothelium of the atrial appendage is selectively deficient in vWF, which has been used as an endothelial cell marker in human vessels (19,20). However, this is not surprising because Yamamoto et al. (21)have recently reported that vWF is differentially expressed in endothelial cells among different tissues or organs in mice.. On the other hand, increased immunoreactivity for vWF in the endocardium was found particularly in the left, compared with the right, atrial ...
TEL :. +86 153 6067 3248 (Intl). US Toll free: 855 777 3210 EU Toll free: 800 3272 9252 Korea Toll free: 001 800 3272 9252 (Telecom ...
Semantic Scholar extracted view of [Studies on histochemistry of blood vessel endothelium and the basement membrane of the capillaries]. by Wiebke Hort et al.
Atherosclerosis is an inflammatory disease in which endothelial cell (EC) activation leads to leukocyte recruitment into artery walls, followed by formation of plaques containing lipid-laden macrophages and smooth muscle cells.1 Plaques can occlude vessels and cause ischemia, or rupture to cause stroke or myocardial infarction. Whereas systemic risk factors such as hypertension, smoking, and obesity play important roles in atherogenesis, plaques show a predilection for vessel branch points and regions of high curvature, where flow is low and shows a variety of complex patterns that are grouped together under the term disturbed flow.2 These areas show increased EC turnover, altered redox regulation, and upregulation of proinflammatory genes that contribute to atherosclerotic progression.3,4 By contrast, areas of high laminar shear show downregulation of proatherogenic genes and upregulation of atheroprotective genes and are resistant to atherosclerosis.5. In vitro, acute application of laminar ...
TY - JOUR. T1 - Vascular endothelium. AU - Daugherty, M. O.. AU - Rich, G. F.. AU - Johns, R. A.. PY - 1995/1/1. Y1 - 1995/1/1. N2 - Our understanding of the vital function of the vascular endothelium in circulatory physiology is rapidly expanding. Endothelium-derived vasoactive substances influence vascular tone, growth, inflammation, and haemostasis. Endothelial dysfunction is implicated in the pathophysiology of cardiovascular diseases such as atherosclerosis, ischaemia-reperfusion injury, hypertension, and congestive heart failure. New pharmacological therapies are evolving from our understanding of the role of the endothelium.. AB - Our understanding of the vital function of the vascular endothelium in circulatory physiology is rapidly expanding. Endothelium-derived vasoactive substances influence vascular tone, growth, inflammation, and haemostasis. Endothelial dysfunction is implicated in the pathophysiology of cardiovascular diseases such as atherosclerosis, ischaemia-reperfusion injury, ...
Mouse Renal Glomerular Endothelial Cells are isolated from normal mouse renal tissue. The cells are characterized by immunofluorescence with antibodies specific to vWF, CD31. T25 flasks is required for cell adhension to the culture vessels. Grow cells in ECM-coated culture vessels with 5% CO2. Each vial contains at least 1x10^6 cells per ml ...
Fenestra® VC is a refined version of Fenestra® LC in which the surface of the lipid emulsion particles is modified so as to alter the recognition of the particle by the receptors on hepatocytes that are responsible for its uptake into the liver. With Fenestra VC, the delayed uptake by liver cells produces an agent with superior blood pool imaging properties that last for several hours after injection. Moreover, the agent remains truly intravascular so long as the endothelial integrity of the vessel is maintained. Like its liver-selective counterpart, Fenestra VC is eventually metabolized and eliminated through the hepatobiliary system.. Because of their comparatively long and stable in vivo residence times (up to several hours), the Fenestra® products have shown considerable promise for use in microCT imaging procedures. The numerous benefits provided by the Fenestra technology will play an instrumental role in facilitating the implementation of microCT imaging as an increasingly important ...
Summary. Endothelium was »discovered« as a separate organ in the last decades of the previous century. For a long time endothelial cells were considered as a very passive monolayer of cells just covering the inner part of vascular walls. The role of these cells was thought to be only a mechanical barrier between circulating blood and vascular structures. Nowadays, after a series of biochemical and experimental studies, one can name endothelium as an organ, covering approximately 700 sqaure meters, weighing about 1.5 kilos in an average male with weight of 70 kg. Not only its quantity, but also its function is amazing. The most prominent and first well studied function of endothelial cells is vasodilatation and vasoconstriction. Normal cells, which are intact and in function produce regularly one of the most important protecting agent in circulation: NO. Normal endothelial cells produce NO as a result of higher blood pressure or growing demand for oxygen. It is produced from aminoacid ...
David H. Adams is the author of this article in the Journal of Visualized Experiments: A Flow Adhesion Assay to Study Leucocyte Recruitment to Human Hepatic Sinusoidal Endothelium Under Conditions of Shear Stress
Vascular endothelium provides a selective barrier between the blood and tissues, participates in wound healing and angiogenesis, and regulates tissue recruitment of inflammatory cells. Nuclear factor (NF)- $$\kappa$$B transcription factors are pivotal regulators of survival and inflammation, and have been suggested as potential therapeutic targets in cancer and inflammatory diseases. Here we show that mice lacking IKK$$\beta$$, the primary kinase mediating NF-$$\kappa$$B activation, are smaller than littermates and born at less than the expected Mendelian frequency in association with hypotrophic and hypovascular placentae. IKK$$\beta$$ -deleted endothelium manifests increased vascular permeability and reduced migration. Surprisingly, we find that these defects result from loss of kinase-independent effects of IKK$$\beta$$ on activation of the serine-threonine kinase, Akt. Together, these data demonstrate essential roles for IKK$$\beta$$ in regulating endothelial permeability and migration, as ...
3D InSight™ Human Liver Toxicology Models Production lead time: 1 week Catalog # Description MT-02-302-04 3D InSight™ Human Liver Microtissues (multi-donor hepatocytes, co-culture with Kupffer cells and liver endothelial cells), 96x Order by Ships on: US Ships on: EU Aug 24 Sep 1 Sep 2 Sep 7 Sep 15 Sep 16 Sep 21 Sep
This competitive renewal continues to explore the general hypothesis (a) that surface expressed proteins control the interactions of endothelial cells with bloo...
The vascular endothelium comprises a dynamic interface with the blood and acts as an integrator and transducer of both biochemical (e.g. inflammatory cytokines)...
Morphogenesis of Endothelium von Gabor M. Rubanyi und Buchbewertungen gibt es auf ReadRate.com. Bücher können hier direkt online erworben werden.
WAVE2 is necessary for limiting gaps and promoting spread-cell morphology in endothelial-cell monolayers. Images are frames from movies, with control from Suppl
These data suggest that the propensity of prostate cancer cells to establish themselves in bone is due, at least in part, to their preferential adhesion to human bone marrow endothelial cells.
Endothelium differentiates in response to tissue-specific signals; brain endothelium expresses tight junctions and transporters which are absent from other endothelia. The promoter of the tight junction protein occludin exhibited strong activity in a brain endothelial cell line, hCMEC/D3 but was inactive in lung endothelial cells. Expression of occludin in brain endothelium corresponded with binding of Sp3 to a minimal promoter segment close to the transcription-start site. However, in lung endothelium Sp-transcription factors did not bind to this site although they are present in the cell nucleus. In contrast, repression of occludin in lung endothelium was associated with the binding of YY1 to a remote site in the promoter region, which was functionally inactive in brain endothelium. The work identified a group of transcription factors including Sp3 and YY1, which differentially interact with the occludin promoter to induce expression of occludin in brain endothelium and repression in other ...
Intracellular pH (pH i) in confluent monolayers of cultured bovine corneal endothelial cells was determined using the pH-dependent absorbance of intracellularly trapped 5(and...
Human liver sinusoidal endothelial cell line with tailored liver endothelial cell culture medium. Cryopreserved liver sinusoidal endothelial cells.
To characterize glucagon-like peptide (GLP)-1 signaling and its effect on renal endothelial dysfunction and glomerulopathy. We studied the expression and signaling of GLP-1 receptor (GLP-1R) on glomerular endothelial cells and the novel finding of protein kinase A-dependent phosphorylation of c-Raf at Ser259 and its inhibition of angiotensin II (Ang II) phospho-c-Raf(Ser338) and Erk1/2 phosphorylation. Mice overexpressing protein kinase C (PKC)β2 in endothelial cells (EC-PKCβ2Tg) were established. Ang II and GLP-1 actions in glomerular endothelial cells were analyzed with small interfering RNA of GLP-1R. PKCβ isoform activation induced by diabetes decreased GLP-1R expression and protective action on the renal endothelium by increasing its degradation via ubiquitination and enhancing phospho-c-Raf(Ser338) and Ang II activation of phospho-Erk1/2. EC-PKCβ2Tg mice exhibited decreased GLP-1R expression and increased phospho-c-Raf(Ser338), leading to enhanced effects of Ang II. Diabetic ...
Glomerular endothelial cells are uniquely adapted for selective permeability and filtration. Although the glomerular endothelium is continuous, it contains fenestrations, which cover up to 50% of the glomerular surface area (12). On conventional electron microscopy these fenestrations appear as ovoid transcellular holes, 60-70 nm in diameter (12). However, the fenestrations (and the glomerular endothelium itself) are covered by glycocalyx, a carbohydrate-rich, gel-like mesh with important roles in capillary permeability, regulation of the interactions between leukocytes and endothelial cells, and transduction of shear stress (12).. In some disease states, endothelial injury leads to altered microvascular permeability and albuminuria. Inflammatory stimuli increase permeability by widening endothelial cell-cell junctions, and in some instances, inducing transcellular holes (13). Endothelial disease is a feature of rapidly progressive forms of GN, including ANCA-associated GN, anti-GBM GN, and ...
Dysfunction of the corneal endothelium reduces the transparency of the cornea and can cause blindness. Because corneal endothelial cells have an extremely limited proliferative ability in vivo, treatment for corneal endothelial dysfunction involves the transplantation of donor corneal tissue. Corneal endothelium can also be restored via intraocular injection of endothelial cells in suspension after their expansion in vitro. Yet, because quality assessment during the expansion of the cells is a destructive process, a substantial number of the cultured cells are lost. Here, we show that the spring constant of the effective interaction potential between endothelial cells in a confluent monolayer serves as a biomarker of the quality of corneal endothelial cells in vitro and of the long-term prognosis of corneal restoration in patients treated with culture-expanded endothelial cells or with transplanted corneas. The biomarker can be measured from phase contrast imaging in vitro and from specular microscopy
The human corneal endothelium regulates the cornea transparency. Its cells, that cannot regenerate after birth, form a tesselated mosaic with almost perfect hexagonal cells during childhood, becoming progressively bigger and less ordered during aging. This study included 50 patients (in 10 decades groups) and 10 specular microscopy observations per patient. Five different criteria were measured on the manually segmented cells: area and perimeter of the cells as well as reduced Minkowski functionals. All these criteria were used to assess the probability of age group membership. We demonstrated that the age evaluation is near the reality, although a high variability was observed for patients between 30 and 70 years old ...
Endothelial cells were isolated from bovine thoracic aorta and cultured. Bovine aortic endothelial cells (BAEC) were incubated with radiolabeled arachidonic acid (3H-AA) or eicosapentaenoic acid (14C-EPA) (1 microM) for 3 hr. Both fatty acids were predominantly incorporated into phosphatidylcholine (57 +/- 2% and 62 +/- 2% respectively) and slightly into phosphatidylethanolamine (11 +/- 0.5% and 12 +/- 0.6% respectively). phosphatidylinositol (26 +/- 1.5% and 10 +/- 0.5% respectively) and neutral lipids (6 +/- 0.5% and 15 +/- 1% respectively). After BAEC incubation with 3H-AA for 24 hr with or without EPA (1 microM), the release of radioactive metabolites of AA induced by thrombin (5.5 U/ml) was strongly reduced by the preliminary treatment with EPA (72 +/- 5%). After BAEC incubation with AA, EPA or vehicle (control), endothelin-1 levels were measured by RIA in the culture medium and we observed that: 1) the basal production of endothelin-1 was not modified after either AA or EPA treatment, 2) the
The major findings described here establish that GATA4 is the molecular master regulator that orchestrates specification of discontinuous sinusoidal endothelium during liver development. This GATA4-dependent transcriptional program determines the functional competence of the hepatic sinusoidal endothelium. As suggested by the fact that the gene expression signatures of fetal LSECs and ectopically GATA4-expressing cultured continuous ECs only partially overlap, organ-specific vascular functions differ in a context-dependent manner: (a) liver endothelial-associated angiokines such as WNT2, HGF, RSPO3, ANG2, and BMP2 do not seem to play a major role in liver development, while they do in establishing metabolic zonation in adult liver (18, 19) or in regulating adult liver regeneration (10, 11); (b) GATA4-expressing LSECs are permissive for transmigration of HSCs during early fetal development, while they become non-permissive during later fetal development despite continued expression of ...
Free radical-induced endothelial membrane dysfunction at the site of the brain barrier: relationship between lipid peroxidation, Na, K-ATPase activity and Cr 51 release
Key Points. Endothelial Bmp6 conditional knockout mice exhibit hemochromatosis, whereas hepatocyte and macrophage Bmp6 conditional knockout mice do not.Our data
The NIDEK CEM-530 is our fastest, easy-to-use specular microscope on the market today. NIDEKs 3D auto-tracking/auto shot - coupled with an analysis time of under two seconds and combined with the solid NIDEK build quality and features - can add up to real value, less downtime, and better patient flow. ...
The short-circuit current (SCC), potential difference (PD), and transendothelial resistance (TER) of confluent monolayers of B4G12 cells were measured with the use of an Ussing chamber as described previously. 17 Before measurements, cell densities were manually counted by microscope (CKX41; Olympus, Tokyo, Japan). The cells cultured on Snapwell inserts (Corning) were held by a specific holder (P2302) with a measurement area of 1.12 cm2. The entire setup was then placed in the Ussing chamber EM-CSYS-2 (Physiologic Instruments, San Diego, CA). The cell surface side was in contact with one chamber, and the Snapwell membrane side or collagen sheet side was in contact with another chamber. The chambers were carefully filled with 4 mL Krebs-Ringer bicarbonate (120.7 mM NaCl, 24 mM NaHCO3, 4.6 mM KCl, 0.5 mM MgCl2, 0.7 mM Na2HPO4, 1.5 mM NaH2PO4, and 10 mM glucose bubbled with a mixture of 5% CO2, 7% O2, and 88% N2 to pH 7.4). The chambers were maintained at 37°C by an attached heater. The SCC was ...
Supplementary MaterialsS1 Fig: COL6 does not enhance lung epithelial cell proliferation. pone.0209095.s004.docx (17K) GUID:?95A94D62-D70D-4D93-9A88-360DB426C86A S2 Text: Methods: buy BMS-354825 Human being lung fibroblast culture. (DOCX) pone.0209095.s005.docx (17K) GUID:?EF3D80B0-1A99-4F45-B95B-40D29CA9082E S1 Appendix: Minimal underlying dataset. (ZIP) pone.0209095.s006.zip (14K) GUID:?D1BC5B89-D8C4-4638-9E81-975B89B3496B Data Availability StatementAll relevant data are within the paper and its Supporting Information documents. Abstract Basement membrane (BM) … [Read more…]. ...
Implanted donor (green) endothelial cells (ECs) form vascular tubes with lumens that must anastomose with host vessels to become part of the functional vasculature. The host vessel in this image is composed of endothelial cells (brown), basement membrane (blue), and pericytes (red) and contains flowing red blood cells. The donor ECs wrap around the host vessel to displace the pericytes and proteolytically attack the basement membrane of the host vessel endothelium via matrix metalloproteinases-9 and -14. Subsequently, the donor ECs may now gain access to the host endothelium and displaces some cells to integrate into the endothelial intima and divert blood into the donor vasculature. See Figure 6 in Cheng et al, page 4740. ...
Embryogenesis of the First Circulating Endothelial Cells. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
The endothelium is the inner lining of our blood vessels. Laid end-to-end, endothelial cells from a single human would wrap more than four times around the world. And its not just an inert layer; its highly metabolically active. Ive....... ...