METABOLISM OF RADIOMANGANESE AND RADIOZINC IN SHEEP — EFFECTS OF INTRARUMINAL DOSING WITH NITRILOTRIACETIC ACID

1979 ◽  
Vol 59 (2) ◽  
pp. 283-289 ◽  
Author(s):  
M. IVAN
Keyword(s):  
Urinary Excretion ◽  
Soft Tissues ◽  
Nitrilotriacetic Acid ◽  
Fecal Excretion ◽  
Rumen Bacteria ◽  
Tissue Samples ◽  
Rumen Protozoa

Two experiments were carried out with rams fed a concentrate diet containing 17 and 27 ppm (air dry basic) of manganese and zinc, respectively. In the first, fistulated rams were dosed intraruminally with 54Mn and samples of rumen contents were taken at different times after dosing. A peak uptake of radiomanganese by mixed rumen bacteria was obtained within 2 h after dosing. The uptake by rumen protozoa was almost unchanged during the first 7 h after dosing. In the second experiment, eight fistulated rams were divided into two groups. One group was dosed intraruminally with 180 mg of nitrilotriacetic acid (NTA) twice daily (before each feeding) for 1 mo and then both groups were dosed intraruminally with 54Mn and 65Zn and total 96-h fecal and urinary collection was commenced. Samples of rumen contents were taken at 2 h. Ninety-six hours after the administration of the radioisotopes the sheep were killed and tissue samples removed. Significantly lower uptakes of 54Mn and 65Zn by the rumen bacteria and protozoa were obtained in the NTA-treated sheep than in control sheep. The uptake of 54Mn by the rumen tissue was significantly higher in the NTA-treated sheep. There were no differences between treatments in the urinary excretion of radioisotopes, while fecal excretion of 54Mn and 65Zn tended to be lower in the NTA-treated sheep. It was apparent that the absorption of 54Mn and 65Zn was slightly increased by intraruminal dosing of sheep with NTA but the rate of uptake of radiomanganese by soft tissues tended to be lower in the NTA-treated sheep.

EFFECTS OF NITRILOTRIACETIC ACID ON APPARENT ABSORPTION AND DUODENAL FLOW OF MANGANESE, IRON, ZINC AND COPPER IN SHEEP

1979 ◽  
Vol 59 (2) ◽  
pp. 273-281 ◽  
Author(s):  
M. IVAN ◽  
M. HIDIROGLOU ◽  
M. IHNAT
Keyword(s):  
Fatty Acids ◽  
Small Intestine ◽  
Volatile Fatty Acids ◽  
Latin Square ◽  
Nitrilotriacetic Acid ◽  
Fecal Excretion ◽  
Rumen Bacteria ◽  
Apparent Absorption ◽  
Iron And Zinc ◽  
Pelleted Diet

A latin square design was used with four sheep, each equipped with a rumen fistula and re-entrant cannula in the proximal duodenum. The four treatments were intraruminal dosings with different amounts (0, 450, 900 and 1800 mg/day) of nitrilotriacetic acid (NTA). The sheep were fed a pelleted diet with excessive concentrations of manganese, iron, zinc and copper. Fecal excretion of iron and zinc increased, and apparent absorption decreased, with increasing dose of NTA. However, only the differences between means for zinc were statistically significant. Fecal excretion and apparent absorption of manganese and copper were not affected by NTA. Flow of soluble iron through the duodenum increased with increasing dose of NTA. There was no effect of NTA on concentrations of manganese, iron, zinc and copper in the rumen bacteria or on microbial activity in the rumen as measured by the concentration of volatile fatty acids in the rumen and by flow of nitrogen into the small intestine.

The effect of rumen protozoa on the urinary excretion of purine derivatives in goats

2003 ◽  
Vol 140 (1) ◽  
pp. 101-105 ◽  
Author(s):  
T. FUJIHARA ◽  
M. TODOROKI ◽  
K. NAKAMURA
Keyword(s):  
Urinary Excretion ◽  
N Balance ◽  
Purine Derivatives ◽  
Purine Derivative ◽  
Rumen Protozoa ◽  
The Mean

Urinary purine derivative (PD) excretion was estimated to examine the effect of rumen protozoa on total PD excretion in goats fed hay and a concentrate diet. The effect of increasing protozoa number in the rumen on nitrogen (N) balance and urinary PD excretion was determined after inoculation. Protozoa increased slowly until 4 days after inoculation, and on the 5th day after inoculation rapidly, finally (10 days) reaching 4·1×105/ml of rumen contents similar to that before defaunation. Urinary N excretion showed a small (non-significant) decrease. Urinary PD excretion did not change until the 7th day, and then the level decreased on the 8th day after faunation presumably due to the effect of increased protozoa in the rumen. The mean urinary total PD excretion significantly (P<0·05) decreased in the defaunated group compared with that in the faunated group. Comparable changes were not seen in plasma PD level of faunated and defaunated groups.

Modeling the Inflation Response of C57BL/6 Mouse Sclera

2011 ◽  
Author(s):  
Kristin M. Myers ◽  
Thao D. Nguyen
Keyword(s):  
Material Properties ◽  
Soft Tissues ◽  
Ganglion Cells ◽  
The United States ◽  
Small Rodent ◽  
Tissue Samples ◽  
Tissue Microstructure ◽  
Material Parameters ◽  
Meaningful Material

Small rodent models have become increasingly useful to investigate how the mechanical properties of soft tissues may influence disease development. These animal models allow access to aged, diseased, or genetically-altered tissue samples, and through comparisons with wild-type or normal tissue it can be explored how each of these variables influence tissue function. The challenges to deriving meaningful material parameters for these small tissue samples include designing physiologically-relevant mechanical testing protocols and interpreting the experimental load-displacement data in an appropriate constitutive framework to quantify material parameters. This study was motivated by determining the possible role of scleral material properties in the development of glaucomatous damage to the retinal ganglion cells (RGC). Glaucoma is one of the leading causes of blindness in the United States and in the world with an estimate of 60 million people affected by this year [1]. Through exploring mouse models, the overall goal of our work is to determine the role of scleral material properties and scleral tissue microstructure in the pathogenesis of glaucoma.

INTAKE, EXCRETION, AND RETENTION OF STABLE STRONTIUM

PEDIATRICS ◽  
1969 ◽  
Vol 43 (4) ◽  
pp. 687-705
Keyword(s):  
Urinary Excretion ◽  
Large Population ◽  
Body Burden ◽  
Compartment Model ◽  
Fecal Excretion ◽  
Average Weight ◽  
Strontium Content ◽  
Calcium Retention ◽  
Study Results ◽  
Discrimination Factors

The average daily strontium intake by 25 infants observed for consecutive periods of approximately 7 months each was 0.60 mg, at a strontium/calcium ratio of 1.24 mg per gram. The amount of strontium and the strontium/calcium ratio in the diet varied widely, which suggests that extensive sampling is needed to obtain representative values for a large population. Milk and formula supplied most of the dietary strontium, but other components of the diet–especially water–contained appreciable amounts of strontium. Average strontium concentrations and strontium/calcium ratios are given for individual infant foods. Strontium balances were obtained for 10 infants in 56 28-day periods. Average corrected intake, fecal excretion, urinary excretion, and retention were 0.66, 0.50, 0.068, and 0.086 mg per day, respectively. Strontium/calcium ratios were 1.46, 2.08, 3.16, and 0.50 mg per gram, respectively. The ratios show strontium to be less readily absorbed and retained than calcium and more effectively excreted in urine. Strontium intake and fecal excretion increased gradually with age, but urinary excretion and retention remained constant. Strontium fecal excretion varied linearly with strontium intake, and strontium urinary excretion was proportional to the square root of the product of calcium intake and urinary excretion. There was a small but significant correlation between strontium and calcium retention. The strontium/calcium ratio in retained material, however, showed no correlation with the strontium/calcium ratio in the diet, so that the ORbody/diet was not constant. In a supporting study, strontium/calcium ratios were measured in bones of Cincinnati infants. Average values for a total of 44 samples were 0.29 ± 0.018 mg per gram at average age 1 day, 0.30 ± 0.013 mg per gram at 34 days, and 0.38 ± 0.029 mg per gram at 190 days. A simple compartment strontium model was constructed by combining information from the calcium and strontium balances in this study, results of several published tracer calcium studies, and average strontium/calcium ratios measured in the bones of Cincinnati infants. The compartments consisted of an exchangeable pool and of non-exchangeable bone, as proposed in several models for adults. For the 10 infants whose strontium balances were obtained, the model coefficients yielded strontium half lives of approximately 2 and 300 days, an ORbody/diet of 0.34 and an ORbone/diet of 0.27 for an average age of 148 days and an average weight of 7.5 kg. Coefficients estimated for a model pertaining to all 30 infants differed only slightly in detail from those for the 10-infant subgroup. Coefficients estimated at 30-day age increments between ages 30 and 300 days indicated that the two characteristic strontium half lives increased gradually with age, and provided an extrapolated strontium body burden at age 1 year of 36 mg or 0.43 mg per gram calcium. The average strontium/calcium ratio in the diet of the infants under study was higher than values reported for surveys of infants' diets in other areas. The ratio in bones collected at Cincinnati was also higher than that reported for other locations. The ORbody/diet in this study was consistent with values obtained in Argentine, British, and other United States' surveys. The discrimination factors and observed ratios that were measured directly or inferred from the model were generally similar to values accepted for adults. Discrimination against strontium relative to calcium occurred during both absorption from the gastrointestinal tract and renal clearance. In summary, this study describes the strontium content of an average infant diet that was freely selected by 30 parents and their pediatricians, and strontium balances for 10 of these infants. Because of ad libitum dietary intake, strontium and calcium consumption varied from period to period, and the effect of strontium and calcium intakes and intake ratios on strontium retention could be evaluated. Variations in the retention of strontium among infants were related to variations in calcium retention. The ORbody/diet, although convenient for predicting average strontium/calcium ratios in retention from average intake ratios, was not useful in predicting variations in retention among the infants. Coefficients for a simple compartment model were derived to compare the infant to the adult and to compute radiostrontium turnover. Balance studies with constant diets at several calcium and strontium levels to test the constancy of the ORbody/diet were suggested, as well as double-tracer experiments with short-lived radiocalcium and radiostrontium at low doses to evaluate the models.

scholarly journals Measurement of strontium in serum, urine, bone, and soft tissues by Zeeman atomic absorption spectrometry

1997 ◽  
Vol 43 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Patrick C D’Haese ◽  
Glen F Van Landeghem ◽  
Ludwig V Lamberts ◽  
Vera A Bekaert ◽  
Iris Schrooten ◽  
...  
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Soft Tissues ◽  
Absorption Spectrometry ◽  
Serum Samples ◽  
Tissue Samples ◽  
Triton X

Abstract To study the possible accumulation of Sr in chronic renal failure patients, methods were developed for the determination of the element in serum, urine, bone, and soft tissues by using Zeeman atomic absorption spectrometry. Serum samples were diluted 1:4 with a Triton X-100–HNO3 mixture, whereas urine samples were diluted 1:20 with HNO3. Bone samples were digested with concentrated HNO3 in stoppered polytetrafluoroethylene (Teflon®) tubes, whereas soft tissues were dissolved in a tetramethylammonium hydroxide solution in water. For serum and urine we used matrix-matched calibration curves, whereas bone and tissue samples were measured against aqueous calibrators. Atomization was performed from the wall of pyrolytically coated graphite tubes for all of the matrices under study. Both inter- and intraassay CVs were &lt;6% (n = 12, n = 10, respectively), and the recovery of added analyte was close to 100% for all of the biological matrices under study. Detection limits were 1.2 μg/L (serum), 0.3 μg/L (urine), 0.4 μg/g (bone), and 2.2 ng/g (soft tissues), whereas the sensitivity determined by the slope of the calibration curve, i.e., the amount of Sr producing a 0.0044 integrated absorbance change in signal, was 2.4 pg, 2.4 pg, 3.9 pg, and 2.6 pg for these matrices respectively. We conclude that the present methods are precise and accurate and easily applicable for both routine use and research investigations. They will allow us to study the metabolism of the element in chronic renal failure patients and shed some light on the association that was recently noted between increased bone Sr concentrations and the development of osteomalacia in these individuals.

Effect of Estrogen on the Peripheral Utilization of Thyroid Hormones

1956 ◽  
Vol 188 (1) ◽  
pp. 30-34 ◽  
Author(s):  
Joseph D. Feldman
Keyword(s):  
Thyroid Hormones ◽  
Urinary Excretion ◽  
Fecal Excretion ◽  
Disappearance Rate

The effect of estrogen on the peripheral utilization of exogenous and endogenous radiothyroxine and exogenous radiotriiodothyronine was studied in thyroidectomized castrate and in castrate rats. Estrogen did not affect the disappearance rate of these hormones from serum nor their space of distribution. Estrogen increased urinary excretion and decreased fecal excretion of radioactive products compared with controls following the administration of radiotriiodothyronine, but it did not influence the excretion of radioactive products after the injection of radiothyroxine or I131. Radiotriiodothyronine was utilized more rapidly than radiothyroxine.

Validation of lactose[15N,15N]ureide as a tool to study colonic nitrogen metabolism

2005 ◽  
Vol 288 (5) ◽  
pp. G994-G999 ◽  
Author(s):  
Karen P. Geboes ◽  
Vicky De Preter ◽  
Anja Luypaerts ◽  
Bert Bammens ◽  
Pieter Evenepoel ◽  
...  
Keyword(s):  
Urinary Excretion ◽  
Nitrogen Metabolism ◽  
Proximal Colon ◽  
Fecal Excretion ◽  
In Vitro Experiments ◽  
Dietary Intakes ◽  
Nitrogen Pool ◽  
Different Types

In vitro experiments have shown that fermentation of carbohydrates prevents accumulation of nitrogen in the colon. Variable results have been obtained on modulation of dietary intakes in vivo. Lactose[15N,15N]-labeled ureide has been proposed as a tool to study colonic nitrogen metabolism. However, on oral administration of the marker, different urinary excretion patterns of the 15N label have been found. In this study, 50 mg lactose[15N,15N]ureide was directly instilled in the colon through an orocecal tube to investigate the colonic handling of this molecule in a direct way. In basal conditions, 42% (range, 37–48%) of labeled nitrogen administered as lactose[15N,15N]ureide was retrieved in urine after 72 h. A substantial variability in total urinary excretion of the label was found, but the urinary excretion pattern of the label was similar in all volunteers. When inulin, a fermentable carbohydrate, was administered together with the labeled marker, a significant decrease in urinary excretion of 15N after 72 h was found, to 29% (range, 23–34%). The effect of a smaller dose of inulin (250 mg) on colonic handling of lactose[15N,15N]ureide (50 mg), was investigated in another group of volunteers, and this time, fecal excretion of the marker was also evaluated. The results seem to indicate that fermentation of inulin causes an increased fecal excretion of the marker, thereby reducing urinary excretion but not retention in the human nitrogen pool. This instillation study shows that lactose[15N,15N]ureide is a tool with good properties to investigate the effect of different types of carbohydrates on nitrogen metabolism in the proximal colon in vivo.

scholarly journals Simulation of the effects of diet on the contribution of rumen protozoa to degradation of fibre in the rumen

1995 ◽  
Vol 74 (5) ◽  
pp. 617-634 ◽  
Author(s):  
Jan Dijkstra ◽  
Seerp Tamminga
Keyword(s):  
Mathematical Model ◽  
Feed Intake ◽  
Rumen Bacteria ◽  
Neutral Detergent Fibre ◽  
Rumen Protozoa ◽  
Intake Level ◽  
Metabolic Activities ◽  
Sugar Levels

A previously described mathematical model, that simulates the metabolic activities of rumen bacteria and protozoa, was used to examine the contribution of protozoa to neutral-detergent fibre (NDF) degradation in the rumen of cattle. Comparisons between predicted and experimentally observed NDF degradation showed general agreement. Further simulations were performed with diets containing variable proportions of concentrate (between 0 and 1 kg/kg diet DM) and at intake levels ranging between 5·3 and 21·0 kg DM/d. The simulated protozoal contribution to NDF degradation was 17–21% at the lowest intake level. Except for the all-concentrate diets, raising the feed intake level reduced this contribution to 5–3% at the highest intake level. The changes in contribution of protozoa to NDF degradation were related to variations in the fibrolytic bacteria: protozoa value and the NDF-degrading activities of protozoa predicted by the model. In simulations where dietary NDF levels were reduced and starch and sugar levels were increased independently, protozoal contribution to NDF degradation generally increased. These differences were reflected also in the generally increased protozoal contribution to NDF degradation predicted in response to a decreased roughage:concentrate value. The contribution of protozoa also generally declined in response to added N. These changes in predicted protozoal contribution to NDF degradation resulting from dietary variations provided possible explanations for the differences in rumen NDF degradation observed when animals are defaunated.

scholarly journals Visualisation of contrast-filled stab wounds in various tissue types with computed tomography

2012 ◽  
Vol 18 (2) ◽  
pp. 164-168 ◽  
Author(s):  
Peter Mygind Leth ◽  
Uffe Stolborg
Keyword(s):  
Computed Tomography ◽  
Contrast Medium ◽  
Soft Tissues ◽  
Ct Scanning ◽  
Tissue Samples ◽  
Stab Wounds ◽  
India Ink ◽  
Sharp Force ◽  
Knife Blade ◽  
Sharp Force Trauma

ABSTRACT Background: Stab wounds are common in homicide cases. Post-mortem multislice computed tomography (PMCT) has proved to be a useful tool in forensic examinations of victims of sharp force trauma, but due the limited resolution of soft tissues, the radiological depiction of a stab channel is difficult. In this study, we have tried to obtain information about the shape of a knife blade by CT scanning contrast-filled experimentally inflicted stab wounds in various types of pig tissue. Methodology: The tissue samples were mounted on floral foam (oasis) with wooden sticks. Two contrast media were used: one was unmodified and easy flowing, and one was made more viscous with polyethylene glycol. Stab channels in ballistic soap were used for comparison. India ink-filled stab channels were investigated histologically to determine the pattern of leakage. Principal findings: We found that the shape of the stab wounds on the CT images from lung and muscle tissue did not correspond well to the shape of the inflicting knife. There was a better correspondence in the images obtained from liver, spleen and kidney. The viscous contrast medium was less likely than the thin (easy flowing) contrast medium to spill into to structures outside the stab channel, but some spillage was observed for both types of contrast medium. Air bubbles were only observed in the viscous contrast medium. Conclusion: Radiological evaluation of a contrast-filled stab wound in isolated tissue blocks did not permit the positive identification of the inflicting weapon, but it was, in tissue blocks from liver, spleen and kidney, possible to obtain a rough idea of the shape of the inflicting knife and to differentiate a knife from a screwdriver.

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