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Showing papers on "Low protein published in 1975"


Journal ArticleDOI
TL;DR: The human plasma apoproteins apoA-I and apoC-I enhanced the activity of partially purified lecithin: cholesterol acyltransferase five to tenfold with chemically defined phosphatidylcholine:cholesterol single bilayer vesicles as substrates with no enhancement of enzyme activity.
Abstract: The human plasma apoproteins apoA-I and apoC-I enhanced the activity of partially purified lecithin: cholesterol acyltransferase five to tenfold with chemically defined phosphatidylcholine:cholesterol single bilayer vesicles as substrates. By contrast, apoproteins apoA-II, apoC-II, and apoC-III did not give any enhancement of enzyme activity. The activation by apoA-I and apoC-I differed, depending upon the nature of the hydrocarbon chains of phosphatidylcholine acyl donor. ApoA-I was most effective with a phosphatidylcholine containing an unsaturated fatty acyl chain. ApoC-I activated LCAT to the same extent with both saturated and unsaturated phosphatidylcholine substrates. Two of the four peptides obtained by cyanogen bromide cleavage of apoA-I retained some ability to activate LCAT. The efficacy of each of these peptides was approximately 25% that of the whole protein. Cyanogen bromide fragments of apoC-I were inactive. The apoproteins from HDL, HDL2, and HDL3, at low protein concentrations, were equally effective as activators of LCATand less effective than apoA-I. Higher concentrations of apoHDL, apoHDL2, and apoHDL3 inhibited LCAT activity. ApoC and apoA-II were both found to inhibit the activation of LCAT by apoA-I. The inhibition of LCAT by higher concentrations of apoHDL was not correlated with the aopA-II and apoC content.

373 citations


Journal ArticleDOI
TL;DR: Addition of methionine to the oral paracetamol dose protects against death and liver injury, and it is suggested that this may be a useful technique for making par acetamol safe against the danger of overdose.

150 citations


Journal ArticleDOI
TL;DR: Lead absorption was increased by high fat, low mineral, low protein and high protein diets but was decreased by high mineral diet, while lowfat, low fibre, high fibre, low vitamin and high vitamin diets had no effects on lead absorption.
Abstract: The nutritional factors which affect lead absorption have been studied. Synthetic diets of known composition were compounded to contain 0·075% Pb as PbCl2 labelled with 203Pb. Rats were exposed to lead for periods of 48 hr. The dietary intake was then measured and the absorption of lead determined by means of a whole-body counter. Lead absorption was increased by high fat, low mineral, low protein and high protein diets but was decreased by high mineral diet. Low fat, low fibre, high fibre, low vitamin and high vitamin diets had no effects on lead absorption.

130 citations


Journal ArticleDOI
TL;DR: Low protein Rh immune globulin, and ultimately column-produced, very low protein, highly purified Rh immune Globulin for intravenous use may prove to be the safest, most economical, and effective material for Rh prevention and total eradication of Rh erythroblastosis fetalis.

113 citations


Journal ArticleDOI
TL;DR: The data indicate that the increased rate of ammoniagenesis which occurs following nephron reduction is markedly influenced by dietary protein content and a lack of enhanced GLDH activity may underlie the lack of increased ammonia production of low protein-fed rats following ne phrectomy.

100 citations


Journal ArticleDOI
TL;DR: Results from published experiments dealing with several aspects of nitrogen utilization by ruminants were used to test the concept of zero utilization of nonprotein nitrogen under conditions where more ammonia is in the rumen than can be converted to microbial protein.

74 citations


Journal ArticleDOI
TL;DR: The overall conclusion is that mammalian metabolism is well adapted to dietary intake and that this adaptation is achieved through dietary control of synthesis and release of key metabolic hormones.
Abstract: Young male rats (100-130 g) were fed diets of equal energy content containing o.5, 1,2,3,5, and 18% lactalbumin consumed either freely or in restricted amounts. The rats receiving low protein diets failed to grow and mature. Those consuming the 0.5 and1% protein diets given freely developed the characteristic features of kwashiorkor including edema, while those receiving the diets in restricted amounts developed the characteristic features of marasmus. The rats fed low protein diets had low plasma levels of essential amino acids; however, the lysine level was well maintained. The plasma levels of nonessential amino acids, especially glycine, alanine, and aspartic and glutamic acids were raised in marasmic rats but were reduced in rats fed low protein diets ad libitum. Young and severly malnourished rats appeared to have limited ability to synthesize urea. Therefore, they excreted more ammonia and other nitrogenous substances such as ethanolamine, and when given an amino acid load, intermediary metabolites of the ingested amino acids. Rats fed low protein diets showed diminution of total liver DNA, RNA, and protein. In addition to the reduction of protein synthesis resulting from decreased cellular RNA, ribosomes from the livers of protein-deficient rats had reduced ability to synthesize proteins. This defect was associated with the detatchment of the ribosomes from endoplasmic reticulum membrane and the elevation of the proportion of monosomes to polyribosomes. Malnutrition did not produce any change in the turnover rate of liver RNA. Protein deficiency caused significant depression of serum insulin, thyroxine, and corticosterone levels. Theoverall conclusion is that mammalian metabolism is well adapted to dietary intake and that this adaptation is achieved through dietary control of synthesis and release of key metabolic hormones.

71 citations


Journal ArticleDOI
TL;DR: Investigation of the possible use of BUN levels as an indicator of recent nutritional status of deer to determine the effect of known levels of energy and protein intake on BUN concentration found it to be of use as an index of recently nutritional status.
Abstract: Nineteen female white-tailed deer fawns (Odocoileus virginianus) were used in a 2 X 2 factorial experiment to determine the effect of 2 levels of energy and 2 levels of protein on food consumption, weight gains, and blood urea nitrogen over a 20-week period beginning when the animals were 3.5 months of age. The 2 levels of ration-digestible energy averaged 2,498 and 3,064 kcal/kg. The 2 levels of protein averaged 9.6 and 18.2 percent. Food consumption tended to be greater in animals on low energy diets but decreased in all treatment groups from November through February. Weight gains were significantly greater (P < 0.05) in animals on high protein diets, but no significant difference was found due to energy. Weight gains decreased significantly (P < 0.01) from the 8th through the 20th week of the experiment. Blood urea nitrogen (BUN) was significantly greater (P < 0.01) in fawns receiving high protein diets than in those receiving low protein. Conversely, fawns on high energy intakes had significantly lower (P < 0.01) BUN than those on low energy intakes. J. WILDL. MANAGE. 39(4):692-698 For several years wildlife biologists have sought indices which would correlate well with the recent nutritional status of deer (Odocoileus spp.) and thus would be useful for evaluating trends in habitat conditions. Bone marrow fat, antler development, rumen content analysis, abomasal parasite counts, and many different hematological characteristics have been examined by various authors. None has proven entirely satisfactory, and it is anticipated that as deer management becomes more intensive the need for good indices of deer and habitat conditions will increase. Recent work on BUN in both domestic and wild species has indicated that this easily-measured characteristic might be of use as an index of recent nutritional status. Torell et al. (1974) and Blowey et al. (1973) have shown that BUN levels can be used as indicators of protein intake in domestic sheep and cattle, respectively. Seal et al. (1972b) suggested that BUN levels also might be useful as an index of recent nutritional status of pregnant white-tailed deer and presented limited data to substantiate this. Further, work by Seal et al. (1972a) on white-tailed deer and Franzmann (1972) on bighorn sheep (Ovis canadensis) has shown that BUN levels are not readily affected by the excitement of restraint or immobilization with certain drugs. The present study was conducted to investigate further the possible use of BUN as an indicator of recent nutritional status of deer. More specifically, the study was to determine the effect of known levels of energy and protein intake on BUN concentration 692 J. Wildl. Manage. 39(4):1975 This content downloaded from 157.55.39.179 on Tue, 12 Apr 2016 10:12:35 UTC All use subject to http://about.jstor.org/terms BLOOD UREA NITROGEN OF DEER FAWNS ? Kirkpatrick et al. 693 Table 1. Ingredient composition of pelleted experimental

64 citations


Journal ArticleDOI
TL;DR: Sedimentation velocity analyses of mixtures of highly purified component proteins of Azotobacter chroococcum are consistent with the formation of a tight 1 : 1 complex in the absence of Na2 S2 O4.

60 citations


Journal ArticleDOI
TL;DR: It is found that the presence of even small amounts of dimer that are necessarily present at the low protein concentrations commonly employed may have a devastating effect upon the reliability of Adair constant determinations.
Abstract: For human hemoglobin, a pronounced dependence of oxygenation curves upon protein concentration can be demonstrated experimentally in the range between 10(-4) and 2 X 10(-6) M heme. The effects of such protein concentration dependence upon analysis of saturation curves have been explored using a model-independent linkage analysis which incorporates the dissociation of tetramers to dimers. We have carried out stimulations of oxygenation curves representing a variety of energy distributions designed to cover a wide range of values which are relevant to known hemoglobin systems and experimental conditions. The resulting simulated oxygenation curves were analyzed by least-squares minimization procedures in terms of the tetramer binding isotherm to yield the four apparent Adair constants. These derived constants were compared with the originally assumed values used in the simulation in order to assess the extent to which their values may be altered by the presence of dimer. For each energy distribution the analysis has been carried out over a wide range of protein concentration. We have found that the presence of even small amounts of dimer that are necessarily present at the low protein concentrations commonly employed may have a devastating effect upon the reliability of Adair constant determinations. In addition to these simulated cases, we have analyzed two sets of highly precise experimental data from the literature in order to assess the degree to which constants obtained may have been influenced by the presence of dimer.

54 citations


Journal ArticleDOI
TL;DR: Correlations between the percentage of essential amino acids and each of plasma transferrin, prealbumin and complement C3 and also between several of the plasma proteins further substantiate their value in the assessment of dietary intake in chronic renal failure.

Journal ArticleDOI
TL;DR: Enhanced placental transfer and fetal uptake also suggested the possibility of adaptation when the calorie supply is adequate, and the relationship between fetal and placental weight was similar in the control and restricted-calorie animals.
Abstract: The effect on the guinea pig conceptus of feeding the mother diets deficient in energy or in protein has been investigated. Fetal uptake of a labelled non-metabolisable amino acid, amino-isobutyric acid, injected into the maternal blood stream, was studied at the end of gestation. Both diets retarded fetal growth, influencing litter number and fetal and placental weights. The relationship between fetal and placental weight was similar in the control and restricted-calorie animals, and the transfer studies showed that placental function and fetal uptake per unit weight was similar in the two. Feeding a low-protein diet caused the ratio between fetal and placental weight to increase; enhanced placental transfer and fetal uptake also suggested the possibility of adaptation when the calorie supply is adequate.

Journal ArticleDOI
TL;DR: Eight hand-reared white-tailed deer fawns were randomly paired and pairs were randomly assigned to 1 of 4 isocaloric diets containing 11, 15, 20, and 25 percent crude protein (dry matter basis) to study their protein requirement.
Abstract: Eight hand-reared white-tailed deer (Odocoileus virginianus) fawns were randomly paired and pairs were randomly assigned to 1 of 4 isocaloric diets containing 11, 15, 20, and 25 percent crude protein (dry matter basis) to study their protein requirement. Thirty-two complete digestibility, nitro- gen balance, and energy balance trials were carried out. Partition of dietary energy was not signifi- cantly affected by protein level in the diet, except that proportion of energy lost in urine, presumably ketones, increased significantly (P < 0.05) with increasing dietary crude protein. Apparent digestibility of protein increased significantly up to 20 percent ration crude protein, but most of this difference was attributable to decreasing proportion of metabolic nitrogen (0.37 g/100 g diet dry matter) in feces; proportion of ingested nitrogen lost in urine increased with increasing nitrogen intake. The fawn's re- quirement for maximum growth (body retention of dietary protein), estimated by regression analysis, was 19 g digestible crude protein per kilogram of metabolic body weight (W075) daily. J. WILDL. MANAGE. 39(3):582-589 White-tailed deer, an aesthetically and economically valuable resource, are increas- ingly threatened by the effects of urban- ization in many areas. Their survival in optimum quantity and quality will depend largely on intensive management based on biologically sound principles. Deer man- agers will need information on the nutri- tional requirements of different age classes of deer throughout the year, and on the value of natural foods in meeting these re- quirements. Fawns probably are the age class most vulnerable to undernutrition during the winter. Certainly the food consumed dur- ing the preceding fall contributes greatly to winter survival. Thompson et al. (1973: 307) reported that the metabolizable energy required for maintenance of fawns is higher (38 percent, our calculation) during pe- riods of weight gain than in winter. They also found that the component of growth described by deposition of body protein may continue despite body weight loss and negative energy balance during the winter. Although energy generally is the most crit- ical factor in deer nutrition, the work of Murphy and Coates (1966) suggested that low protein content of foods may account for low productivity and suboptimum phys- ical development as in most other species.

Journal ArticleDOI
TL;DR: If the reabsorbed urea was used completely for protein synthesis in the rumen, 4 g crude protein could be made daily in the lichen fed animals, which would be a very significant contribution to the nitrogen economy of animals which are usually in a negative nitrogen balance when lichens are the main food consumed.
Abstract: Renal reabsorption of urea was studied in 8 9-month old reindeer calves fed low protein (19–34 g crude protein, mostly lichens) and high protein (68–69 g crude protein, lichens + soybean meal) diets. Low protein diets fed for a 3-month period resulted in an average renal reabsorption of 93% of the filtered urea, while only 50 % was reabsorbed on the high protein ration. It was calculated that if the reabsorbed urea was used completely for protein synthesis in the rumen, 4 g crude protein could be made daily in the lichen fed animals. This amount would be a very significant contribution to the nitrogen economy of animals which are usually in a negative nitrogen balance when lichens are the main food consumed.

Journal ArticleDOI
TL;DR: The results demonstrate that dietary protein level has little or no effect on the utilization of energy by growing rats when the pattern of intake is controlled by gastric intubation.
Abstract: 1. The deposition of fat and protein and the utilization of energy by growing rats offered diets ad lib. or in controlled amounts by gastric intubation has been investigated. Diets contained 50, 75, 100 or 200 g protein/kg, mainly as casein. 2. Gain of body-weight and protein increased with increasing dietary protein concentration when animals received the same energy intake, although the reverse was true for fat deposition. However, the differences in live-weight gain were almost entirely due to changes in body water. The dry-matter content of the gain in animals given low-protein diets was 770 g/kg compared to 360 g/kg in those given the control diet. 3. Energy retention was unaffected by dietary protein level in groups given the same energy intake by gastric intubation. In Expt 1 daily heat production increased significantly (P smaller than 0-05) with increasing protein level (50, 75 and 200 g protein/kg diet) when energy intake was constant, but in Expt 2 there was no significant effect of protein level (50, 100 and 200 g protein/kg diet). Problems arose in the selection of a suitable basis for comparison of heat production between groups because of the differences in body-weight and body composition. 4. The energy requirement for zero energy balance was approximately 10 percent lower for the low-protein groups than for those given the diet containing 200 g protein/kg when food intake was just above the maintenance level. When the requirement was expressed per unit metabolic body size (W0-75 KG) dietary protein level had no significant effect. The mean values for Expts 1 and 2 were 452 and 456 kJ respectively. 5. The energy cost of weight gain increased as dietary protein level decreased in pairs of groups gaining at the same rate. The extra energy ingested by the animals given the lower protein level was converted to body tissue with an efficiency of at least 0-70. 6. Striking differences were observed in body composition and energy retention of the two pairs of groups used for the comparison of tube-feeding and ad lib. feeding. With the diet containing 50 g protein/kg, tube-fed rats gained significantly more weight (P smaller than 0-01) and more fat, dry matter and energy (P smaller than 0-001) than their ad lib, counterparts given an isoenergetic intake. 7. The results demonstrate that dietary protein level has little or no effecon the utilization of energy by growing rats when the pattern of intake is controlled by gastric intubation.

Journal ArticleDOI
TL;DR: The phylogenetic relationship of carboxylase from Euglena and from three higher plants was investigated, and the size, subunit formation, and quaternary structure of RUDPcase from the various sources seemed to be similar.
Abstract: Ribulose 1,5-diphosphate carboxylase (RUDPcase) from autotrophically grown Euglena gracilis was purified to homogeneity as measured by analytical ultracentrifugation, polyacrylamide gel electrophoresis, and immunoprecipitation reactions. The enzyme represented about 9% of total protein and 24% of soluble protein in the autotrophic cell. Light-grown, heterotrophic cells seemed to contain considerably less RUDPcase. Native carboxylase from autotrophic Euglena showed an s(20, w) at low protein concentrations of 17 to 17.5, suggesting a molecular weight of >500,000 daltons. Upon denaturation, the enzyme dissociated into two subunits having different amino acid compositions and molecular weights of 59,000 and 12,000 daltons. Based upon the amino acid mass ratios, a quaternary organization of 7 to 8 large and 8 to 10 small subunits per native enzyme molecule was indicated.The phylogenetic relationship of carboxylase from Euglena and from three higher plants was investigated. In general, the size, subunit formation, and quaternary structure of RUDPcase from the various sources seemed to be similar. A partial immunochemical reaction between anti-RUDPcase serum from Euglena and the enzymes from lettuce, cucumber, and New Zealand spinach suggested that the algal and higher plant carboxylases were related but not identical. This was borne out by amino acid analyses which showed a close correspondence between the large, but not the small, subunits of Euglena and lettuce.

Journal ArticleDOI
TL;DR: Using low protein diets, administration of a supplement with small amounts of essential amino acids (EAA) resulted in accelerated growth associated with a higher calorie intake, a better utilization of ingested calories for growth and a greater fall of blood urea nitrogen concentration.

Journal ArticleDOI
TL;DR: A fraction of bovine achilles tendon extract isolated on the basis of its affinity for collagen yielded a mixture which comprised a glycoprotein and two constituents containing hexuronic acid, which appeared to be a normal proteoglycan, with a low protein content.

Journal Article
TL;DR: Elevated citrulline levels in uremic tissue appear to be caused by a decrease conversion of citruLLine to arginine in the kidney, as well as altered activities of monoamine oxidase and diamine oxidase in kidney and other tissues.
Abstract: The chronically uremic rat has been used as a model to study amino acid metabolism in uremia. Uremic rats fed low protein diets (6% casein) survived longer than uremic rats receiving either higher levels of dietary protein or a low protein diet supplemented with a mixture of nonessential amino acids. Alterations in plasma amino acid levels were observed in the uremic rats and were similar to those found in patients with renal failure. Plasma concentrations of citrulline, free tryptophan, glycine and the methylhistidines were increased and levels of serine, ornithine, lysine, total tryptophan, tyrosine, and the tyrosine-phenylalanine ratio were reduced. The metabolic basis of the altered tyrosine-phenylalanine ratio in plasma was studied. Tyrosine aminotransferase (TAT) and phenylalanine hydroxylase (PHL) activity were normal in the liver, but renal PHL activity of was decreased as compared to control rats. Tissue concentrations of citrulline were also found to be raised in liver and muscle of uremic rats. The activity of ornithine transcarbamoylase, was reduced in the liver and arginine synthetase activity was decreased in the kidneys of uremic rats. Thus elevated citrulline levels in uremic tissue appear to be caused by a decrease conversion of citrulline to arginine in the kidney. Preliminary studies of tryptophan metabolism in uremic rats have shown elevated brain levels of 5-hydroxyindoleacetic acid and increased hepatic tryptophan oxygenase activity. Increased plasma amine levels were associated with altered activities of monoamine oxidase and diamine oxidase in kidney and other tissues.

Journal ArticleDOI
TL;DR: Although RNA polymerase and histones are fixed to chromatin after formaldehyde treatment with high efficiency, only a minor fraction of non-histone protein is fixed under similar conditions, and even after washing in high salt to minimize adventitious association, most remaining non-history protein fails to be fixed.
Abstract: The reality of the nonrandom distribution of histones along the chromatin strand was investigated in several ways. It does not appear to derive from histone exchange during shearing and is evident in chromatin fixed with formaldehyde prior to shearing. Endogenous or Escherichia coli polymerase are preferentially associated with regions of chromatin with a low protein/DNAratio. Although RNA polymerase and histones are fixed to chromatin after formaldehyde treatment with high efficiency, only a minor fraction of non-histone protein is fixed under similar conditions. Even after washing in high salt to minimize adventitious association, most remaining non-histone protein fails to be fixed. The utility of this approach for defining chromosomal proteins is discussed.

Journal ArticleDOI
TL;DR: A method utilizing a modified biuret formulation and colorimeter range expander permits protein determination in the 0.01–3.0 mg/ml range at a sampling rate of 60/hr without significant sample interaction, useful in investigations involving large numbers of samples with microgram protein content.

Journal ArticleDOI
TL;DR: The fibrinogenolytic activity of the salivary gland extract from the Brazilian blood-sucking leech Haementeria lutzi Pinto 1920 is characterized and the substance, named here hementerin, is stable and active at very low protein concentration.
Abstract: The fibrinogenolytic activity of the salivary gland extract from the Brazilian blood-sucking leech Haementeria lutzi Pinto 1920 is characterized. The substance, named here hementerin, is stable and active at very low protein concentration, does not exhibit direct proteolytic activity on casein, fibrinogen, or fibrin, and is able to activate the human plasma fibrinolytic system in the presence of a serum cofactor and/or calcium. This indirect activation mechanism distinguishes hementerin from hirudin and shows a similarity with streptokinase. The effect on blood coagulation tests is reported.

Journal ArticleDOI
TL;DR: Exogenous insulin increased the uptake of l‐[G‐3H]tryptophan into the brain and its incorporation into protein and plasma insulin concentrations were reduced in the low protein and ‘restricted high protein’ animals and the plasma corticosterone concentration was raised in theLow protein animals.
Abstract: —Male Wistar rats aged 24 days were divided into three groups. Two groups were given a high protein (250 g/kg casein) and a low protein (30 g/kg casein) diet respectively. The third group was given an amount of the high protein diet containing the same amount of energy as that consumed by the low protein diet rats. The plasma of the animals on low protein contained 20% of the concentration of tryptophan of animals on the other two diets. In these animals the concentration of tryptophan was reduced in the forebrain, cerebellum and brain stem, and the concentrations of 5-HT and 5-hydroxyindoleacetic acid were reduced in the forebrain and brain stem. The low protein diet decreased the total uptake of l-[G-3H]tryptophan into the brain and its incorporation into brain protein. Plasma insulin concentrations were reduced in the low protein and ‘restricted high protein’ animals and the plasma corticosterone concentration was raised in the low protein animals. Exogenous insulin did not raise the plasma tryptophan concentration in the low protein animals but it increased the uptake of l-[G-3H]tryptophan into the brain and its incorporation into protein. Rehabilitation for 7 days restored the plasma and brain tryptophan concentrations and those of brain 5-HT and 5-hydroxyindoleacetic acid to control values.

Journal ArticleDOI
TL;DR: Results indicate that the suckled, preruminant lamb exhibits sensitivity to dietary amino acid imbalance, in a manner analogous to that found in simple-stomached animals.
Abstract: Eleven Poll Dorset times Merino crossbred female lambs 4 weeks of age were trained to suck liquid diets from bottles. In three separate experiments liquid diets providing 14-2% (expt 1) 10-6% (expt 2) or 8-0% (expt 3) of gross energy as protein and amino acids were fed. Responses in voluntary intake, growth rate and changes in plasma amino acid concentrations were studied when complete or incomplete mixtures of amino acids were added to the liquid diet. These mixtures supplied either: (1) all amino acids in quantities to bring the total of protein plus amino acids to provide more than 20% of dietary gross energy, the amino acids being provided in proportions estimated to meet adequately the lamb's requirements ('complete'); or (2) as the same total amount of amino acids but with the amino acid supplement devoid of threonine ('low-threonine', expts 1 and 2) or isoleucine ('low isoleucine', expt 3). In experiment 1, there was no food intake or growth depression after feeding the amino acid mixture lacking threonine. In both experiments 2 and 3, voluntary food intake was depressed to about 50% of that observed in lambs fed the low protein diet, when the amino acid mixture devoid of threonine or of isoleucine, respectively, was fed. Addition of the missing amino acid to the low threonine and low isoleucine diets resulted in recovery of voluntary intake in experiments 2 and 3 respectively, but no significant improvement above that found after feeding the low protein (basal) diet. In experiments 1 and 2, after feeding the low threonine diet the threonine concentration in the blood plasma decreased markedly, while concentrations of total amino acids were elevated. Although there was no improvement in growth or food intake, the feeding of the diet containing the complete amino acid mixture resulted in an elevation of all essential amino acids including threonin. Similarly in experiment 3, plasma isoleucine concentration decreased in the lambs fed the isoleucine imbalanced diet. Results indicate that the suckled, preruminant lamb exhibits sensitivity to dietary amino acid imbalance, in a manner analogous to that found in simple-stomached animals. These results also clearly illustrate a depression in food intake associated with the deletion of a specific essential nutrient from the diet of the lamb.

Journal Article
TL;DR: A study of serum proteins in patients on regular hemodialysis has shown that many have low serum transferrin levels but near normal serum albumin and normal or raised pre-albumin levels.
Abstract: A study of serum proteins in patients on regular hemodialysis has shown that many have low serum transferrin levels but near normal serum albumin and normal or raised pre-albumin levels. Hemoglobin values were related to transferrin levels. Low transferrin levels also occurred in patients with advanced osteitis fibrosa. Deficient protein intake seems the likely explanation. Measurement of pre-albumin does not reflect low protein intake in chronic renal failure; reasons for this discussed.

Book ChapterDOI
TL;DR: The chapter discusses charcoal treatment of serum or plasma, adsorption of steroids to various materials, elimination of binding inhibitors, anomalous mobility of glycoproteins in dodecyl sulfatc-polyacrylamidc electrophoresis, isoelectric focusing of steroid-binding glycoproduins, and determination of sedimentation coefficients at low protein concentrations.
Abstract: Publisher Summary The principal procedures used in a laboratory for the purification and binding analysis of the steroid-binding serum proteins have been previously described in Methods in Enzymology . For this reason, this chapter is limited to a number of unpublished observations made over the years, all relevant to preparative and analytical studies in the field of steroid–protein interactions. The chapter discusses charcoal treatment of serum or plasma, adsorption of steroids to various materials, elimination of binding inhibitors, anomalous mobility of glycoproteins in dodecyl sulfatc-polyacrylamidc electrophoresis, isoelectric focusing of steroid-binding glycoproteins, and determination of sedimentation coefficients at low protein concentrations.

Book ChapterDOI
01 Jan 1975

Journal ArticleDOI
TL;DR: Biological tests performed on both raw and boiled protein mixtures showed WPC to be superior to DSM in supplementing maize and rice proteins and the nutritive value of a potato-WPC mixture was studied and compared with those of potato-lactalbumin and potato-egg mixtures, both of which are known to contain protein of very high quality for man.
Abstract: Liquid whey has long been known to contain proteins of high nutritional value, but their use in human nutrition has been complicated by the high lactose and low protein contents of the whey. Modern technological processes of gel filtration and ultrafiltration have made possible the production of whey protein concentrates (WPC) low in lactose. In this investigation, the supplementary effect of WPC on maize and rice proteins was compared with the corresponding effect of dried skim milk (DSM). Protein quality was studied by chemical and biological methods on growing rats. Biological tests performed on both raw and boiled protein mixtures showed WPC to be superior to DSM in supplementing maize and rice proteins. The nutritive value of a potato-WPC mixture was also studied and compared with those of potato-lactalbumin and potato-egg mixtures, both of which are known to contain protein of very high quality for man. The comparison indicated that a potato-WPC mixture may also possess high protein quality.

Journal ArticleDOI
TL;DR: Insulin-carbohydrate relationships were investigated in four groups of young rats fed low protein diets differing in carbohydrate and fat contents and found that liver glycogen was high in the fed state and normal in the fasted state, whereas muscle glycogenwas normal in both nutritional states.
Abstract: Insulin-carbohydrate relationships were investigated in four groups of young rats fed low protein diets differing in carbohydrate and fat contents: (1) a diet in which the nonprotein energy was provided by fatty acids (FA); (2) a similar diet in which the fatty acids were substituted by neutral fat (NF); (3) FA diet supplemented with glycerol (FA-Glyc); and (4) a carbohydrate-rich diet (HC). Control rats were fed a stock diet. Rats fed the FA diet lost weight, were hypoglycemic and hypoinsulinemic in the fed state and normoglycemic and normoinsulinemic in the fasted state, and had an impaired glucose tolerance and hyperinsulinemia after a glucose load. Liver and muscle glycogen were low in fed rats. Fasting increased glycogen in liver and decreased glycogen in muscle. NF animals gained weight, were hypoglycemic in both fed and fasted states, and their plasma glucose level after an oral glucose load was almost normal. Plasma insulin/glucose ratio, both in fed and fasted states and after a glucose load indicated hyperinsulinism, which was accompanied by obesity. Muscle and liver glycogen were low in fed animals and did not change after a fast. Supplementation of the FA diet with glycerol (FA-Glyc) abolished weight loss and fasting hyperglycemia and normalized plasma glucose and insulin response to a glucose load. Rats fed the HC diet had an improved glucose tolerance and an increased sensitivity to insulin. Liver glycogen was high in the fed state and normal in the fasted state, whereas muscle glycogen was normal in both nutritional states.

Journal ArticleDOI
TL;DR: It is suggested that UDP-xylose is acting as a substrate analogue of UDP-glucose and causes protein-conformational changes on binding to the enzyme and lowers the affinity of the enzyme for NADG.
Abstract: 1. UDP-xylose and UDP-glucose both bind to UDP-glucose dehydrogenase in the absence of NAD+, causing an enhancement of protein fluorescence. 2. The binding of UDP-xylose is pH-dependent, tighter binding being observed at pH8.2 than at pH8.7. 3. At low protein concentrations sigmiodal profiles of fluorescence enhancement are obtained on titration of the enzyme with UDP-xylose. As the protein concentration is increased the titration profiles become progressively more hypebolic in shape. 4. The markedly different titration profiles obtained on titrating enzyme and the enzyme-NAD+ complex with UDP-xylose suggests a conformational difference between these two species 5. NAD+ lowere the apparent affinity of the enzyme for UDP-xylose. 6. There is no change in the apparent moleculare weight of UDP-glucose dehydrogenase on binging UDP-xylose. 7. Protein modification by either diethyl pyrocarbonate or 5, 5'-dithiobis-(2-nitrobenzoate) does not "desensitize" the enzyme with respect to the inhibition by UDP-xylose. 8. UDP-xylose lowers the affinity of the enzyme for NADG. 9. It is suggested that UDP-xylose is acting as a substrate analogue of UDP-glucose and causes protein-conformational changes on binding to the enzyme.