Distribution of radioiron in larval lampreys, Petromyzon marinus L., following administration of 55ferrous citrate

1990 ◽  
Vol 68 (9) ◽  
pp. 1839-1856 ◽  
Author(s):  
S. J. Hall ◽  
J. H. Youson
Keyword(s):  
Epithelial Cells ◽  
Alimentary Canal ◽  
Petromyzon Marinus ◽  
High Serum ◽  
The Body ◽  
Initial Increase ◽  
Iron Storage ◽  
Ferrous Citrate ◽  
Glomerular Filtrate ◽  
Over Time

Light microscopic autoradiography and quantitative tissue analyses were used to examine the distribution of radioiron in larvae (ammocoetes) of the lamprey Petromyzon marinus L. over time following the injection of 55ferrous citrate (55Fe). It was found that a single intraperitoneal injection of 55Fe is an efficient method of introducing iron into ammocoetes, and radioiron retention within the body remained high throughout the 28-d experiment. Immediately after radioiron administration the isotope was transported in the serum fraction of the blood to sites of iron storage and elimination. The liver is the most important target organ for iron in ammocoetes, and radioiron acquired from the alimentary canal, skin, carcass, and blood contributed to the initial increase in this organ. Data indicated only temporary storage in the liver; between 3 and 16 d, radioiron was redistributed by the blood to the skin, kidney, alimentary canal, and carcass. Biliary transport of radioiron from the liver to the lumen of the anterior intestine may also explain the lowering of iron concentrations in the liver and the rise in levels in the alimentary canal during this interval. The redeposition of 55Fe in the liver at 16 d may signify longer-term storage of the metal in this organ. There is movement of radioiron in and out of the carcass tissues over time, and most of the radioactivity is localized in the adipose tissue. The epithelial cells of the proximal tubules of the kidney absorb and concentrate the radioiron presumably present in the glomerular filtrate. This concentration probably reflects both the absorption of iron bound to ferritin and a mechanism necessary for maintaining the high serum iron levels of ammocoetes. The release of mucus from iron-laden mucous cells of the skin and exfoliation of radioiron-laden epithelial cells in specific regions of the posterior intestine are possible routes for iron elimination. However, percent incorporation of the injected radioactivity was still high at the end of the experiment, indicating that iron excretion in ammocoetes is relatively low or that it is a slow process. These data support the notion that lampreys provide a useful animal model for the study of iron metabolism in vertebrates.

scholarly journals Editorial Review: The Control of Iron Balance by the Intestinal Mucosa

Blood ◽  
1963 ◽  
Vol 22 (4) ◽  
pp. 441-449 ◽  
Author(s):  
WILLIAM H. CROSBY
Keyword(s):  
Epithelial Cells ◽  
Binding Capacity ◽  
The Body ◽  
Dietary Iron ◽  
Iron Storage ◽  
Iron Stores ◽  
Excess Iron ◽  
Internal Surfaces ◽  
Editorial Review ◽  
Iron Binding Capacity

Abstract In this hypothetical model of intestinal function the ferritin apparatus of the absorptive epithelial cells provides the most important mechanism for day-to-day control of iron balance. Iron incorporated into epithelial ferritin cannot be released and therefore is lost when the cell is lost at the end of the life cycle. Information concerning the state of the body’s iron stores is conveyed to the intestine, perhaps by the concentration of plasma iron or iron-binding capacity. When the iron stores are replete the newly forming epithelial cells are constructed to contain a functional ferritin apparatus capable of synthesizing apoferritin and incorporating iron into ferritin, thus preventing its entering the body. However, this mechanism is not completely adequate to intercept all unneeded iron. When too much iron has bypassed the ferritin apparatus it may be intercepted by tissue macrophages in the villus and lost when these macrophages work their way into the lumen; or it may be loaded into newly forming villous epithelial cells thereby saturating a part of their ferritin capacity. Cells thus loaded would develop increased resistance to the incursion of dietary iron; they would also carry the ferritin iron away with them at the end of their life span. In iron deficiency the absorptive cells are constructed with a relative lack of ferritin apparatus so that dietary iron can pass freely into the cell and thence freely into the body. In iron storage disease other populations of cells are used for excretion of iron. In general these are the glandular epithelial cells and tissue macrophages. Both varieties of cells are able to accept and store relatively large amounts of nonfunctional iron. They are deciduous cells which are shed from the internal surfaces of the body, and when they go their iron goes with them. The capacity of the excretory mechanism is not great, perhaps about 5 mg. per day. When the rate of introduction of iron into the body exceeds this capacity, siderosis of parenchymal tissues develops due to accumulation of excess iron.

scholarly journals The prevalence of underweight in 9–10-year-old schoolchildren in Liverpool: 1998–2006

2009 ◽  
Vol 12 (7) ◽  
pp. 953-956 ◽  
Author(s):  
Lynne M Boddy ◽  
Allan F Hackett ◽  
Gareth Stratton
Keyword(s):  
Mass Spectrum ◽  
Body Mass ◽  
The Body ◽  
Fitness Testing ◽  
Policy Makers ◽  
Substantial Problem ◽  
Prevalence Of Obesity ◽  
Grade 3 ◽  
The City ◽  
Over Time

AbstractObjectiveTo estimate the prevalence of underweight between 1998 and 2006 in Liverpool schoolchildren aged 9–10 years using recently published underweight cut-off points.Design and settingStature and body mass data collected at the LiverpoolSportsLinx project’s fitness testing sessions were used to calculate BMI.SubjectsData were available on 26 782 (n13 637 boys, 13 145 girls) participants.ResultsOverall underweight declined in boys from 10·3 % in 1998–1999 to 6·9 % in 2005–2006, and all sub-classifications of underweight declined, in particular grade 3 underweight, with the most recent prevalence being 0·1 %. In girls, the prevalence of underweight declined from 10·8 % in 1998–1999 to 7·5 % in 2005–2006. The prevalence of all grades of underweight was higher in girls than in boys. Underweight showed a fluctuating pattern across all grades over time for boys and girls, and overall prevalence in 2005–2006 represents over 200 children across the city.ConclusionsUnderweight may have reduced slightly from baseline, but remains a substantial problem in Liverpool, with the prevalence of overall underweight being relatively similar to the prevalence of obesity. The present study highlights the requirement for policy makers and funders to consider both ends of the body mass spectrum when fixing priorities in child health.

scholarly journals Detection of Acetaminophen and Its Glucuronide in Fingerprint by SALDI Mass Spectrometry Using Zeolite and Study of Time-Dependent Changes in Detected Ion Amount

Analytica ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 66-75
Author(s):  
Toshiki Horikoshi ◽  
Chihiro Kitaoka ◽  
Yosuke Fujii ◽  
Takashi Asano ◽  
Jiawei Xu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Glucuronic Acid ◽  
Laser Desorption ◽  
The Body ◽  
Time Dependent ◽  
Laser Desorption Ionization ◽  
Fingerprint Analysis ◽  
Desorption Ionization ◽  
Acid Conjugate ◽  
Over Time

The ingredients of an antipyretic (acetaminophen, AAP) and their metabolites excreted into fingerprint were detected by surface-assisted laser desorption ionization (SALDI) mass spectrometry using zeolite. In the fingerprint taken 4 h after AAP ingestion, not only AAP but also the glucuronic acid conjugate of AAP (GAAP), caffeine (Caf), ethenzamide (Eth), salicylamide (Sala; a metabolite of Eth), and urea were detected. Fingerprints were collected over time to determine how the amounts of AAP and its metabolite changed with time, and the time dependence of the peak intensities of protonated AAP and GAAP was measured. It was found that the increase of [GAAP+H]+ peak started later than that of [AAP+H]+ peak, reflecting the metabolism of AAP. Both AAP and GAAP reached maximum concentrations approximately 3 h after ingestion, and were excreted from the body with a half-life of approximately 3.3 h. In addition, fingerprint preservation was confirmed by optical microscopy, and fingerprint shape was retained even after laser irradiation of the fingerprint. Our method may be used in fingerprint analysis.

scholarly journals CHANGES IN FINE STRUCTURE DURING SILK PROTEIN PRODUCTION IN THE AMPULLATE GLAND OF THE SPIDER ARANEUS SERICATUS

1969 ◽  
Vol 42 (1) ◽  
pp. 284-295 ◽  
Author(s):  
Allen L. Bell ◽  
David B. Peakall
Keyword(s):  
Fine Structure ◽  
Epithelial Cells ◽  
Protein Production ◽  
Distal Portion ◽  
Silk Gland ◽  
The Body ◽  
Single Type ◽  
Secretory Cells ◽  
The Web ◽  
Tunica Intima

The ampullate silk gland of the spider, Araneus sericatus, produces the silk fiber for the scaffolding of the web. The fine structure of the various parts of the gland is described. The distal portion of the duct consist of a tube of epithelial cells which appear to secrete a substance which forms the tunica intima of the duct wall. At the proximal end of the duct there is a region of secretory cells. The epithelium of the sac portion contains five morphologically distinct types of granules. The bulk of the synthesis of silk occurs in the tail of the gland, and in this region only a single type of secretory droplet is seen in the epithelium. Protein synthesis can be stimulated by the injection of 1 mg/kg acetylcholine into the body fluids. 10 min after injection, much of the protein stored in the cytoplasm of the epithelial cells has been secreted into the lumen. 20 min after stimulation, the ergastoplasmic sacs form large whorls in the cytoplasm. Protein, similar in electron-opacity to protein found in the lumen, begins to form in that portion of the cytoplasm which is enclosed by the whorls. The limiting membrane of these droplets is formed by ergastoplasmic membranes which lose their ribosomes. No Golgi material has been found in these cells. Protein appears to be manufactured in the cytoplasm of the tail cells in a form which is ready for secretion.

Lipidomics reveals perturbations in the liver lipid profile of iron overloaded mice

Metallomics ◽  
2021 ◽  
Author(s):  
Haoxuan Ding ◽  
Qian Zhang ◽  
Xiaonan Yu ◽  
Lingjun Chen ◽  
Zhonghang Wang ◽  
...  
Keyword(s):  
Iron Overload ◽  
Iron Status ◽  
Liver Lipid ◽  
Density Lipoprotein ◽  
Global Scale ◽  
The Body ◽  
Control Group ◽  
Sod Activity ◽  
Liver Iron ◽  
Iron Storage

Abstract Iron overload is an important contributor to disease. The liver, the major site of iron storage in the body, is a key organ impacted by iron overload. While several studies have reported perturbations in liver lipids in iron overload, it is not clear, on a global scale, how individual liver lipid ions are altered. Here, we used lipidomics to study the changes in hepatic lipid ions in iron-overloaded mice. Iron overload was induced by daily intraperitoneal injections of 100mg/kg body weight iron dextran for one week. Iron overload was verified by serum markers of iron status, liver iron quantitation, and Perls’ stain. Compared with the control group, the serum of iron-overload mice exhibited low levels of urea nitrogen and high-density lipoprotein (HDL), and high concentrations of total bile acid, low-density lipoprotein (LDL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH), suggestive of liver injury. Moreover, iron overload disrupted liver morphology, induced reactive oxygen species (ROS) production, reduced superoxide dismutase (SOD) activity, caused lipid peroxidation, and led to DNA fragmentation. Iron overload altered the overall composition of lipid ions in the liver, with significant changes in over 100 unique lipid ions. Notably, iron overload selectively increased the overall abundance of glycerolipids and changed the composition of glycerophospholipids and sphingolipids. This study, one of the first to report iron-overload induced lipid alterations on a global lipidomics scale, provides early insight into lipid ions that may be involved in iron overload-induced pathology.

Epithelial cells and their importance in the body

1927 ◽  
Vol 23 (12) ◽  
pp. 1287-1287
Keyword(s):  
Epithelial Cells ◽  
The Body

With a number of new studies the author proves his earlier view that epithelial cells produce a hormone circulating in the blood and passing into milk during lactation. The switching off of this hormone when the epithelial cells are removed leads to a decrease of calcium in the blood and causes tetany.

scholarly journals On rolling friction

2019 ◽  
Vol 485 (3) ◽  
pp. 295-299
Author(s):  
A. P. Ivanov
Keyword(s):  
Friction Coefficient ◽  
Angular Velocity ◽  
Viscous Friction ◽  
Rolling Friction ◽  
The Body ◽  
Normal Velocity ◽  
Contact Conditions ◽  
Combined Motion ◽  
Pure Rolling ◽  
Over Time

The dependence of rolling friction on velocity for various contact conditions is discussed. The principal difference between rolling and other types of relative motion (sliding and spinning) is that the points of the body in contact with the support change over time. Due to deformations, there is a small contact area and, entering into contact, the body points have a normal velocity proportional to the diameter of this area. For describing the dependence of the friction coefficient on the angular velocity in the case of “pure” rolling, a linear dependence is proposed that admits a logical explanation and experimental verification. Under the combined motion, the rolling friction retains its properties, the sliding and spinning friction acquiring the properties of viscous friction.

scholarly journals DAAM mediates the assembly of long-lived, treadmilling stress fibers in collectively migrating epithelial cells in Drosophila

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Kristin M Sherrard ◽  
Maureen Cetera ◽  
Sally Horne-Badovinac
Keyword(s):  
Epithelial Cells ◽  
Cell Movement ◽  
Stress Fibers ◽  
Linear Trajectory ◽  
Epithelial Migration ◽  
Cells In Culture ◽  
Multiple Cell ◽  
Developmental Switch ◽  
Over Time

Stress fibers (SFs) are actomyosin bundles commonly found in individually migrating cells in culture. However, whether and how cells use SFs to migrate in vivo or collectively is largely unknown. Studying the collective migration of the follicular epithelial cells in Drosophila, we found that the SFs in these cells show a novel treadmilling behavior that allows them to persist as the cells migrate over multiple cell lengths. Treadmilling SFs grow at their fronts by adding new integrin-based adhesions and actomyosin segments over time. This causes the SFs to have many internal adhesions along their lengths, instead of adhesions only at the ends. The front-forming adhesions remain stationary relative to the substrate and typically disassemble as the cell rear approaches. By contrast, a different type of adhesion forms at the SF’s terminus that slides with the cell’s trailing edge as the actomyosin ahead of it shortens. We further show that SF treadmilling depends on cell movement and identify a developmental switch in the formins that mediate SF assembly, with Dishevelled-associated activator of morphogenesis acting during migratory stages and Diaphanous acting during postmigratory stages. We propose that treadmilling SFs keep each cell on a linear trajectory, thereby promoting the collective motility required for epithelial migration.

scholarly journals Impact of Baseline BMI upon the Success of Latina Participants Enrolled in a 6-Month Physical Activity Intervention

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Sheri J. Hartman ◽  
Shira I. Dunsiger ◽  
Dori W. Pekmezi ◽  
Brooke Barbera ◽  
Charles J. Neighbors ◽  
...  
Keyword(s):  
Physical Activity ◽  
Cognitive Processes ◽  
Physical Activity Intervention ◽  
The Body ◽  
Physical Activity Interventions ◽  
Family Social Support ◽  
Longitudinal Regression ◽  
Baseline Bmi ◽  
The Relationship ◽  
Over Time

High rates of obesity in Latinas highlight the need to determine if physical activity interventions are equally effective across the body mass index (BMI) range. Thus, this study assessed how BMI impacts success of Spanish-speaking Latinas in a culturally and linguistically adapted theory-based physical activity intervention (). Longitudinal regression models tested the relationship between baseline BMI and outcomes. Overall, a trend for a negative association was found between baseline BMI and self-reported physical activity and theoretical constructs targeted by the intervention over time. For example, someone with a 25 kg/m2BMI would report, on average, 27.5 more minutes/week of activity compared to someone with a 30 kg/m2BMI at followup. Furthermore, higher baseline BMI was significantly associated with lower self-efficacy, behavioral and cognitive processes of change, and family social support over time. These findings suggest that participants with higher BMI may need additional intervention to promote physical activity.

Digestion in Ascidians and the Influence of Temperature

1929 ◽  
Vol 6 (3) ◽  
pp. 275-292
Author(s):  
N. J. BERRILL
Keyword(s):  
Enzyme Activity ◽  
Body Temperature ◽  
Digestive Enzymes ◽  
Alimentary Canal ◽  
The Body ◽  
Maximum Efficiency ◽  
Bile Pigment ◽  
Optimum Temperature ◽  
Different Temperatures ◽  
Pass Through

1. The mechanism of feeding and digestion in the Pyurid Ascidians Tethyum pyriforme americanum and Boltenia ovifera is described. 2. The structure and histology of the "liver" is described and it is shown that it is primarily an organ of secretion. 3. It is found that the only digestive enzymes are those poured into the gut by the liver, and consist of a powerful amylase, a protease, a very weak lipase, and also an invertase, a maltase, and a lactase. 4. The brownish pigment of the liver gives reactions with acids somewhat like those of bile pigment. There is no trace of bile salts, however, nor of cholesterol. 5. The amylase has an activity range from pH 6.0 topic pH 8.5 with an optimum near pH 7.5. The protease is active from pH 6.0 to above pH 10.0. A similar protease is secreted by Molgula citrina and Ascidia prunum. 6. The relative strengths of the amylase and protease are compared, the amylase being very much the stronger. 7. While experiments of brief duration indicate an optimum temperature for enzyme activity above 40° C, the more prolonged the experiments the lower does the optimum become. Whatever the optimum may be after an experiment of 2 hours' duration, it falls about 20° C. during the next 45 hours, if the experiments be so prolonged. 8. At 15° C. and at 10° C. the food takes about 35 and 55 hours respectively to pass through the alimentary canal, and at 50 C. somewhere between 70 and 90 hours. These temperatures approximately cover the normal range in temperature of the environment, and therefore of the animal itself. 9. From experiments lasting 33 hours the optimum temperature for enzyme activity was found to be about 17° C.; that is, within one or two degrees of the body temperature. From experiments lasting 57 hours the optimum temperature was found to be about 13° C ; that is, within three degrees of the body temperature. 10. These temperature optima not only represent the relative amounts of substrate converted at different temperatures, but also represent the absolute amounts converted and convertible. 11. The enzymes, amylase and protease, are two-thirds to three-quarters destroyed during their period of activity within the alimentary canal of the animal, and in order to utilise the remainder the digestion mixture would have to be retained within the canal for twice as long a time. 12. Therefore it seems probable that the organism in making such a compromise between a high activity of the enzyme and its economical use is working to a maximum efficiency; and it is possible that a permanent increase in the stability of the digestive enzymes would be turned to advantage through a more prolonged retention of the food within the gut.

Sign in / Sign up

Export Citation Format

Share Document