bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro alterations in cytoskeletal tensional homeostasis control gene expression in tendon cells
Authors: Lavagnino Michael , Arnoczky Steven P. 
Published: May 2005

AbstractAn in vitro collagen gel system was used to determine the effect of alterations in cytoskeletal tensional homeostasis on gene expression in tendon cells. Collagen gel matrices, seeded with rat tail tendon cells, underwent cytochalasin D and gel contraction treatments designed to alter the internal cytoskeletal homeostasis of the cells. Gels were examined for cytoskeletal organization using a rhodamine phalloidin stain for actin. The effect of altered cytoskeletal organization on mRNA expression of a catabolic (interstitial collagenase) and anabolic (α1(I) collagen) gene was examined using northern blot analysis. Tendon cells in adhered gels demonstrated a highly organized cytoskeleton and showed evidence of α1(I) collagen mRNA expression but no evidence of collagenase mRNA expression. Treatment of the attached gel with cytochalasin D disrupted the cytoskeletal organization and resulted in the upregulation of collagenase mRNA and the inhibition of α1(I) collagen mRNA expression. Release of the gels resulted in a cell mediated gel contraction, an immediate loss of cytoskeletal organization, and an mRNA expression pattern similar to that seen with cytochalasin D treatment. Isometric contraction of the gel on itself or around a 3‐point traction device resulted in an mRNA expression pattern similar to the adhered gel. Gene expression in the contracted gels could be reversed through chemical cytoskeletal disruption or removal of the traction device which permitted further gel contraction. The results of the study suggest that tendon cells can establish an internal cytoskeletal tension through interactions with their local extracellular environment. Alterations in this tension appear to control the expression of both catabolic and anabolic genes in a reciprocal manner. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
Effect of trunk flexion on cervical muscle EMG to rear impacts
Authors: Kumar Shrawan , Ferrari Robert , Narayan Yogesh 
Published: May 2005

AbstractObjective: To determine the effect of occupant positioning on the response of the cervical muscles to whiplash‐type posterolateral impacts.Methods: Twenty healthy volunteers underwent left posterolateral whiplash‐type impacts with the volunteers seated “out‐of position”. Electromyograms of the cervical muscles were recorded.Results: Whether having the trunk flexed to the left or right at the time of impact, the muscle responses were low in magnitude, showing a trend to increasing EMG responses with increasing acceleration (P > 0.05). The time to onset and time to peak electromyogram for most muscles showed a trend to progressively decrease with increasing levels of acceleration. With the subject flexed to the left, all muscles generated 31% or less of the maximal voluntary contraction electromyogram. With the subject flexed to the right, all muscles generated 27% or less of their maximal electromyogram. In both positions, the trapezii were the most active (P < 0.05). Thus, having the trunk flexed out of neutral posture at the time of impact produces a very low magnitude cervical muscle response compared to impacts with the trunk in neutral posture.Conclusions: In the absence of bodily impact, the flexed trunk posture appears to produce a biomechanical response that would probably decrease the likelihood of cervical muscle injury in low velocity posterolateral impacts. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved.
The influence of the microflora of the alimentary tract on protein digestion in the chick
Authors: Salter D. N. , Coates Marie E. 
Published: May 2005

1. The course of digestion of freeze-dried and heat-damaged egg albumen labelled with14C in all its constituent amino acids was compared in germ-free and conventional chicks. The albumen was given at a level of 10% in a test meal containing 28% protein. Samples of digesta were taken 5 h later and analysed for14C and nitrogenous constituents.2. After administration of unheated albumen, 11% of the14C remained in the germ-free gut, compared with 23% in the conventional gut. The poorer digestibility of the heat-damaged albumen was shown by recovery of 42 and 47% of the14C from the gut of germ-free and conventional birds respectively.3. With both diets there was a higher14C: nitrogen ratio in the contents of the lower gut of conventional birds. Most of the N remaining in the gut was composed of protein or the hydrolysis products of protein, the amounts of which tended to be higher in the germ-free environment; urea and uric acid formed only a small proportion of the total N. There was less urea and more uric acid in the lower gut and excreta of conventional chicks.4. It was concluded that microbial activity did little to increase the availability of protein to the chick. However, its effect on the nitrogenous material in the lower part of the alimentary tract might result in low recovery of N in the faeces and thus lead to erroneously high estimates of protein quality in tests with conventional chicks.
Detection of early protein-calorie malnutrition (pre-kwashiorkor) in population groups
Authors: Prasanna H. A. , Desai B. L. M. , Narayana Rao M. 
Published: May 2005

1. The heights and weights and the serum total protein concentration and ratio nonessential to essential amino acids (NEA:EA ratio) were determined in twenty-six Indian children, aged from 1·5 to 5 years, suffering from early protein-calorie malnutrition (pre-kwashiorkor children).2. The heights and weights of the majority of the children approximated to 75–85% of the values for normal Indian children. The serum NEA:EA ratio of the children varied from 2·5 to 4·0. There was no correlation between this ratio and weight deficit. In healthy children of the same socio-economic group, the serum NEA:EA ratio varied from 1·5 to 2·1 with a mean of 1·7. The results show that the NEA:EA ratio may be useful as an index for the detection of pre-kwashiorkor conditions.3. There was a significant (P< 0·05) negative correlation (r = −0·45) between serum albumin and NEA:EA ratio of the children. All the children showed consistently a significant increase in serum γ-globulin.
Copper and molybdenum in subcellular fractions of rat liver
Authors: Mills C. F. , Mitchell R. L. 
Published: May 2005

1. Black-hooded weanling rats were given a copper-deficient diet or diets providing 3 ppm Cu with or without supplements containing combinations of molybdate, sulphate and sulphide salts to provide 35 ppm molybdenum and 2μg atoms sulphur/g. Changes in weight and blood haemoglobin concentration were studied during 48 d of treatment. The subcellular distribution of Cu and Mo in the liver was subsequently determined.2. Rats fed on the Cu-deficient diet had a lower growth rate than animals receiving 3 ppm Cu and suffered a decline in blood haemoglobin concentration; Mo supplementation of the diet providing 3 ppm Cu produced similar adverse effects on growth but not on Hb. Effects of Mo on growth were exacerbated by a sulphide supplement which also decreased the rate of the gain in Hb concentration. This concentration of dietary sulphide was without effect when Mo was omitted from the diet.3. The Cu-deficient diet decreased both the Cu concentration and proportion of total liver Cu in mitochondria + microsome and supernatant fractions of liver.4. Mo-supplemented diets greatly increased both the Cu and Mo contents of all liver fractions. This phenomenon is considered in relation to previous suggestions that an unavailable Cu–Mo complex can form in tissues as a response to Mo accumulation.
The effect of drying and ensiling grass on its digestion in sheep
Authors: Beever D. E. , Thomson D. J. , Pfeffer E. , Armstrong D. G. 
Published: May 2005

1. The effect of drying and ensiling ryegrass on the site of digestion of the energy andcarbohydrate fractions was studied in sheep fitted with rumen cannulas and re-entrant can-nulas in the proximal duodenum and terminal ileum.2. The sheep were given fresh (frozen) grass, dried grass, wilted and unwilted silage pre-pared from herbage harvested from the same sward. The grass diets were offered twice dailyto each animal and paper impregnated with chromium sesquioxide was administered twicedaily into the rumen. Twenty-four hour collections of duodenal and ileal digesta, adjusted togive 100 yo recovery of Cr2O3, were analysed to determine the extent of digestion in the fore-stomachs, the small intestine and the caecum and colon.3. Total digestibility of the gross energy was similar for the fresh grass, dried grass andwilted silage diets (67·4,68·1 and67·5 %)but higher for the unwilted silage (72·0 %, P < 0·01).There was an increased flow of energy into the small intestine when the sheep were given driedgrass and unwilted silage. The proportion of the apparently digested energy lost within thesmall intestine was greater when the dried grass was given (302 yo) than when the fresh grasswas given (23·6 yo).4. Drying or ensiling of wilted material affected digestion neither in the entire alimentarytract nor in the different sections of the tract, of some carbohydrate fractions. About 97 yo ofthe digested water-soluble carbohydrate, over 90 yo of the digested cellulose and over 70 yo ofthe digested hemicellulose were digested before reaching the small intestine. The increasedamount of energy entering the duodenum of the sheep given the dried grass was notaccounted for by changes in the fate of these carbohydrate fractions in the digestive tract. Withunwilted silage, digestibilities of the cellulose and hemicellulose fractions were higher, andlower proportions of the digested carbohydrates were lost before the small intestine.
Ammonia in the large intestine of herbivores
Authors: Hecker J. F. 
Published: May 2005

1. The object was toinvestigate the importance of urea a source of ammonia in the large intestine of herbivores. Urea was present in small intestinal contents of slaughtered horses in concentrations similar to those in blood but, in the small intestine of salughtered sheep, the urea was less than in blooc.2. There was little ammonia in small intestinal contents of slaughtered horses but consider-able ammonia was present in small intestinal contents of slaughtered sheep. The ammonia in small intestinal contents of the slaughtered sheep was probably formed from urea, as ileal con-tents taken from a sheep with an ileal cannula contained considerable urea and little ammonia.3. The ammonia concentration in caecal contents of sheep was related to the concentration of urea in blood except when ileal contents were prevented from entering the caecum.4. Ileal digesta of sheep contained more free amino nitrogen than did caecal digesta.5. Ammonia was absorbed more rapidly than water from the caecum of sheep. The rate of absorption was related to the concentration of ammonia in the caecum.
An attempt to estimate total body fat and protein in malnourished children
Authors: Halliday D. 
Published: May 2005

1. An attempt was made to measure body volume and body fat in malnourished children using the same closed-circuit apparatus for both determinations. If these measurements were sufficiently accurate, they would enable total body protein to be calculated.2. A helium dilution technique was used to estimate the volume of the child. Although highly reproducible measurements were obrained for the volume of inanimate objects by this techinque, the results with children were erratic.3. The fat stores of the child were determind by measuring the amount of cyclopropane (C2H4) which would dissolve in the body. This technique gave acceptable answers with marasmic children who have little subcutaneous fat, but with obese children equilibrium could not be obtained in an acceptably short period of time. It is not practicable to calculate the equilibrium concentration by extrapolation of the uptake curve in obese children.
Growth hormone in infant malnutrition: the arginine test in marasmus and kwashiorkor
Authors: Beas F. , Contreras I. , Maccioni A. , Arenas Sara 
Published: May 2005

1. Experiments in children and in animals seem to demonstrate that in marasmic malnutrition there is a reduction in the secretion of growth hormone. To study this problem the fasting, resting plasma concentrations of growth hormone were determined, before, and 45 and 60 min after, stimulation with an intravenous dose of arginine, in six infants with marasmus, in six infants with kwashiorkor and in five normal infants.2. The values of plasma growth hormone (4·5 ± 0·97 ng/ml) in marasmic infants were significantly (P < 0·001) lower than those of the controls (7·8 ± 2·6 ng/ml), and responded little to stimulation with arginine (5·1 and 5·8 ng/ml at 45 and 60 min respectively), in contrast to those in the control group, which rose to 16·4 and 14·6 ng/ml. In children with kwashiorkor the values were very variable, but generally high, and showed little response (25·6 ± 13·3 before and 25·0 ± 17·6 and 14·2 ± 5·3 ng/ml at 45 and 60 min after stimulation respectively).3. These results demonstrate that the responses of the hypophysis to deprivation of calories and protein (marasmus) and to protein deprivation (kwashiorkor) are different: in marasmus there is a progressive adaptation, with low secretion and poor reaction to stimulation, whereas in kwashiorkor the process is acute with high basal values of plasma growth hormone.
The distribution of copper, zinc and manganese in various regions of the brain and in other tissues of children with protein-calorie malnutrition
Authors: Lehmann B. H. , Hansen J. D. L. , Warren P. J. 
Published: May 2005

1. The distribution of copper, zinc and manganese in seven regions of the brain, liver, heart, muscle from the abdominal wall, and skin of children was determined by means of atomic absorption spectrophotometry.2. The results showed significantly lower levels of Cu, Zn and Mn in livers of children with kwashiorkor compared with control subjects. The concentrations of these three elements were higher in livers of children with marasmus than in livers of children suffering from kwashiorkor and not significantly different from those of control subjects.3. The Cu concentration in muscle obtained from the abdominal wall of subjects with kwashiorkor and the Mn concentration in heart muscle of all groups with protein-calorie malnutrition were significantly lower than the respective values for the control group.4. There was no significant difference between Cu, Zn or Mn concentration in brain tissues of control subjects and in those with protein-calorie malnutrition.
The measurement of exchangeable potassium in living pigs and its relation to body composition
Authors: Fuller M. F. , Houseman R. A. , Cadenhead A. 
Published: May 2005

1. Twenty pigs were reared to a weight of 90 kg on various dietary regimens so that their lipid content varied from 16 to 38%;. They were injected intravenously with ~ 400 μCi of 42KCl. The animals were killed ~ 28 h after injection and their contents of water, lipid, sodium and potassium were determined.The specific activity of plasma reached equilibrium 10–12 h after injection, that of urine not until 20 h after.Losses of activity in urine, faeces and gut contents in the 24 h after injection amounted to 3·1, 0·3 and 1·5% of the injected dose, respectively.Total body K was more accurately estimated from urine specific activity than from plasma specific activity.Exchangeable K, estimated from urine specific activity Ke(u), was highly correlated with the weight of fat-free tissue (r = 0·93), the residual standard deviation of the regression being 1·8 kg fat-free tissue.Percentage extractable fat was equally well correlated with Ke(u) (r = −0·92).
The effect of age and level of dietary calcium intake on calcium metabolism in sheep
Authors: Braithwaite G. D. , Riazuddin Sh. 
Published: May 2005

1. A combination of balance and isotope techniques has been used to study the effects of age and dietary calcium content on Ca metabolism in forty-two wether sheep.2. The amount of Ca absorbed by young growing animals varied significantly with intake. The percentage of the dietary Ca absorbed, however, remained unchanged. In older animals the amount of Ca absorbed was not altered by changes in intake, but decreased slightly with age.3. Retention of Ca was directly related to the amount of Ca absorbed and was independent of age or breed. Furthermore, nearly all the Ca absorbed above the minimum mean amount required for maintenance was retained.4. Faecal endogenous loss of Ca also was related to the amount of Ca absorbed. Values for faecal endogenous Ca were much lower than those used in the calculation of dietary require-ments by the Agricultural Research Council (1965).5. Urinary Ca excretion was variable, and was not related to age or changes in dietary Ca intake.6. Increased absorption of Ca in young growing animals was accompanied by a decreased rate of bone resorption, but the rate of bone accretion remained unchanged. Changes in dietary Ca in older animals had no effect on either of these two processes. Results indicate that bone resorption is the main pathway governing Ca homoeostasis. Both the rates of Ca accretion into bone and resorption from bone decreased with age.7. Neither the rapidly exchangeable Ca pool (P) nor the slowly exchangeable bone pool (E) was altered by changes in dietary intake in young or mature animals. Both, however, decreased in size with age.8. The size of the slowly exchangeable pool (E) was directly related to the rate of Ca accretion into bone. 9. The results were used to calculate dietary Ca requirements of sheep gaining weight at different rates, and these values have been compared with values recommended by the Agricultural Research Council (1965).
Plasma and blood volume studies in malnourished Iraqi children
Authors: Shakir A. , Hindawi A. Y. , El-Bedri A. L. 
Published: May 2005

1. The plasma and blood volumes of twenty-eight Iraqi children were measured. Twenty-four of them were malnourished in varying degrees and four were normal children who acted as controls. None of the children was anaemic.2. There was an increase in the plasma and blood volumes per unit body-weight correlating with the degree of malnourishment (P< 0·001).3. There was little variation in the values for plasma and blood volumes when calculated per unit body length; the values were less constant when calculated per unit body surface.4. The effect of age on the plasma and blood volumes per unit body-weight was less than the effect of the degree of malnutrition.5. There was no correlation between the plasma volume of malnourished children and their corrected venous haematocrit, if children with severe anaemia were excluded.
The effects of different dietary contents of protein on amino acid and glucose production and on the contribution of amino acids to gluconeogenesis in sheep
Authors: Reilly P. E. B. , Ford E. J. H. 
Published: May 2005

1. Free amino acid entry rates, rates of portal uptake of amino acids and rates of glucose synthesis from amino acids have been measured during the continuous intravenous infusion of [U-14C]-labelled mixed amino acids in six sheep receiving diets that supplied different amounts of protein.2. In four of these sheep and in one other, total rates of glucose production have been measured using continuous intravenous infusions of [U-14C]-labelled glucose.3. A signiiicant correlation was found between total amino acid entry rate ( Y mg/min.kg) and daily protein intake ( X g/kg):Y= 2·14+ 1·38X (r = 0·878, 0·02 > P > 0·01).4. A significant correlation was found between the rate of absorption of amino acids into the portal system ( Y mg/min.kg) and the daily protein intake ( X g/kg):Y= 0·58 + 0·58X (r = 0·884, 0·02 > P > 0·01).5. A highly significant correlation was found between total glucose production rates (Ymglmin. kg) and daily protein intake ( X g/kg): and daily protein intake ( X g/kg): Y = 2.14+ 1.38X (r = 0·878, 0·02 > P > 0·01).Y= 0·375f0·702X (r = 0·866, 0·005 > P > 0·001).6. The mean proportional contribution to total amino acid entry made by portal absorption was 33·5 f 1·8 yo (six animals).7. A significant correlation was found between the rate of glucose production from amino acids (Ymg/min.kg) and the rate of entry of amino acids ( X mg/min.kg):Y= 0-189X-0·414 ( r = 0·84, 0·01 > P > 0·005).8. The best approximation of the proportion of glucose derived from amino acids was 28·16 f 5·1 % (six animals).9. The specific radioactivities of amino acids in liver, kidney and muscle did not approach those found in plasma during infusions of [U-14C]-labelled mixed amino acids of up to 6·75 h.
The effects of vitamin E and training on physiological function and athletic performance in adolescent swimmers
Authors: Sharman I. M. , Down M. G. , Sen R. N. 
Published: May 2005

1. Two experimental groups, each of thirteen boarding schoolboys, were given either 400 mg α-tocopheryl acetate or placeboes daily in addition to their normal diet during training in swimming and various athletic activities over a period of 6 weeks. Evaluation of the experimental treatments was made from tests of anthropometric status, cardiorespiratory efficiency and motor fitness and performance, which were administered at the beginning and end of the experimental period.2. Whereas training significantly improved physiological function and performance in both groups (P < 0·05), vitamin E did not.
Metabolism of heat-damaged proteins in the rat
Authors: Ford J. E. , Shorrock C. 
Published: May 2005

1. Freeze-dried cod muscle and casein were subjected to various conditions of heat treat-ment. Diets containing the different products, or the unheated materials, were given to a group of four adult male rats during successive 48 h periods, and urine was collected during the second 24 h of each 48 h period. A further collection of urine was made from the rats after they had been given protein isolated from heated skim-milk powder. The content and amino acid composition of the ‘peptide’ and ‘free amino acids’ in the urines were determined.2. Heat damage to the cod-fillet protein increased the total urinary excretion of peptide-bound amino acids, from 18·6 to 48·8 µmol/rat.d. The composition of the peptide also changed, and in particular there was a marked increase in lysine, from 2·98 to 20·30 µmol %. Three amino acids - lysine, aspartic acid and glutamic acid - together comprised nearly 70 % of the total amino acid residues. There was a corresponding increase in urinary excretion of free amino acids, from 53·7 to I 14·4 µmol/rat.d. The combined losses of lysine in urinary peptide and free amino acids were 1·5 % of the total lysine ingested, as against 0·3 % for the unheated cod fillet.3. The effects of similar heat treatment of casein on the composition of the urinary peptide and free amino acids were less marked. There was no increase in total urinary peptide excretion and there was a smaller increase in the lysine content of the peptide.4. In urine of rats given protein isolated from heated skim-milk powder, the peptide hydro-lysate was rich in lysine and in furosine, which together comprised 41 mol % of the total amino acid composition. These compounds were presumably formed, together with a smaller quantity of pyridosine, from lysine-carbohydrate complex in the urine. It is probable that, as compared with free lysine, the lysine-carbohydrate complex was absorbed relatively in-efficiently from the rat intestine.5. The findings are discussed in relation to the wider question of the metabolism of the ‚unavailable peptide’ that is released in the course of digestion of heat-damaged protein.