Showing papers on "Low protein published in 1990"
TL;DR: Two different morphometric analyses showed that in the LP neonate B-cell proliferation and islet size were reduced in the head of the pancreas and in the pancreatic tail, these parameters were also decreased but to a lesser extend.
Abstract: The administration of a low protein (LP, 8% protein/dry matter) but isocaloric diet to gestating rats did not affect their fertility, but slightly reduced the quantity of food intake as well as body weight gain. The LP diet also did not affect the placental weight, but the weight of the offspring was decreased. Accordingly the fetal endocrine pancreas was altered by the LP diet. Two different morphometric analyses showed that in the LP neonate B-cell proliferation and islet size were reduced in the head of the pancreas. In the pancreatic tail, these parameters were also decreased but to a lesser extend. Islet vascularization in the neonates was dramatically reduced in both parts of the pancreas when the mothers were fed with the LP diet.
658 citations
TL;DR: Three different strategies on the Fv-fragment of the well-characterized phosphocholine binding antibody McPC603 expressed and secreted in Escherichia coli are tested: chemical cross-linking of the variable domains, introduction of an intermolecular disulfide bond, and construction of a peptide linker to produce a "single-chain" Fv
Abstract: Fv-Fragments of antibodies may dissociate at low protein concentrations and are too unstable for many applications at physiological temperatures. To stabilize Fv-fragments against dissociation, we have tested and compared three different strategies on the Fv-fragment of the well-characterized phosphocholine binding antibody McPC603 expressed and secreted in Escherichia coli: chemical cross-linking of the variable domains, introduction of an intermolecular disulfide bond, and construction of a peptide linker to produce a "single-chain" Fv-fragment. All the linked fragments show hapten affinities nearly identical with that of the whole antibody independent of protein concentration and are significantly (up to 60-fold) stabilized against irreversible thermal denaturation. All genetically engineered linked Fv-fragments can be obtained in native conformation in E. coli. The reported strategies for generating Fv-fragments with improved physicochemical properties may extend their usefulness in biotechnology as well as in therapeutic and diagnostic applications.
554 citations
TL;DR: In this paper, the effects of substituting added water (AW) for fat on textural and sensory properties of bologna ranging from 30%fat-10%AW to 5% fat-35%AW were investigated.
Abstract: Effects of substituting added water (AW) for fat on textural and sensory properties of bologna ranging from 30%fat-10%AW to 5%fat-35%AW Sensory springiness, firmness, and cohesiveness increased with higher protein content (P < 005) Instron fracturability and hardness were affected more by AW than fat and were lower (P < 005) for the high AW, low protein bolognas Color was affected more by fat than AW; low-fat bolognas were darkest (P < 005) Uncooked batters within a fat level were less viscous (P < 005) and had lower shear values as AW increased Cooking and purge losses increased (P < 005) as fat was decreased and AW increased Substituting AW for fat was effective in preventing undesirable changes associated with low-fat, 10% AW products Regression analyses indicated that bologna with 10% fat would require 243% AW to approximate the sensory firmness of bologna with 30% fat and 10% AW
155 citations
TL;DR: Activity and cross-linking studies have confirmed the presence of inactive multimeric protein species and the dimer formation has been determined to be the initiating step in the aggregation of CAB during refolding.
Abstract: Bovine carbonic anhydrase B (CAB) is chosen as the model protein to study the phenomenon of protein aggregation, which often occurs during the refolding process. Refolding of CAB from 5 M GuHCl has been observed by quasi-elastic light scattering (QLS), which confirms the formation of a molten globular protein structure as reported previously [Semisotnov, G. V., Rodionova, N. A., Kutyshenko, V. P., Ebert, B., Blanck, J., & Ptitsyn, O. B. (1987) FEBS Lett. 224, 9-13]. QLS analysis reveals the formation of multimeric species prior to precipitation. Activity and cross-linking studies have confirmed the presence of inactive multimeric protein species. The dimer formation has been determined to be the initiating step in the aggregation of CAB during refolding. Activity studies have indicated that the first intermediate observed in the refolding pathway of CAB aggregates to form the inactive dimer. The rate of formation of the dimer has a stoichiometric dependence on the final protein concentration. The dimer formation rate is a function of the final guanidine hydrochloride (GuHCl) concentration to the inverse 6.7 power, which correlates well with the binding of GuHCl to the native protein in 0.60-0.80 M GuHCl. These rate dependencies require the refolding of CAB to be performed at high GuHCl concentrations (1 M GuHCl) and low protein concentrations (less than 1 mg/mL) to avoid the formation of aggregates. Alternatively, refolding can be performed by allowing the first intermediate to form the second intermediate prior to further dilution or dialysis. The aggregation of a hydrophobic first intermediate species is likely to be common to the refolding of other molten globular proteins.
150 citations
TL;DR: The effects of protein limitation on IGF-I and serum albumin gene expression in young growing rats maintained on isocaloric diets containing 20%, 12%, 8%, or 4% protein, and the possible regulation of the IGFBP-2 gene in the protein-limited animals was analyzed was analyzed.
Abstract: Circulating levels of insulin-like growth factor I (IGF-I) and serum albumin are decreased under conditions of chronic dietary protein limitation. To investigate the biochemical mechanism(s) involved in the regulation of IGF-I and serum albumin synthesis by dietary protein, we studied the effects of protein limitation on IGF-I and serum albumin gene expression in young growing rats maintained on isocaloric diets containing 20%, 12%, 8%, or 4% protein. Animals maintained on the 12%, 8%, or 4% protein diets exhibited slight, moderate, or severe growth deficiency, respectively, and a decreased abundance of hepatic IGF-I messenger RNA (mRNA). The decrease in IGF-I mRNA was most pronounced for the largest [7.7 kilobase (kb)] species, which was decreased by 87% in animals maintained on the 4% protein diet compared with animals on the 20% protein diet. The 0.9 kb species of IGF-I mRNA exhibited a smaller (46%) reduction in abundance in animals maintained on the 4% protein diet. The differential regulation of the 7.7 kb IGF-I mRNA species compared with the shorter IGF-I mRNA species suggests that a sequence or sequences within the long 3'-untranslated region of this mRNA species may play a role in regulating its abundance under conditions of protein limitation. Serum albumin mRNA was also decreased (by 62%) in the animals maintained on the 4% protein diet. The level of serum albumin gene transcription was not decreased in animals on the low protein diets, suggesting that nutrition regulates albumin mRNA at a posttranscriptional step. There was considerable animal-to-animal variability in the level of IGF-I gene transcription within each dietary group. The mean level of IGF-I gene transcription was decreased by 46% in the animals on the 4% protein diet compared with animals on the 20% protein diet, although this decrease was not statistically significant because of the animal-to-animal variability in IGF-I gene transcription within the dietary groups. Additional studies of brain RNA from animals on the four diets indicated that brain IGF-II mRNA was decreased by 57% in animals on the 4% protein diet. It has been demonstrated recently that expression of the gene for IGF binding protein-2 (IGFBP-2) is strongly induced in the liver of fasting animals. To investigate the possible regulation of the IGFBP-2 gene in the protein-limited animals, the abundance of liver and brain IGFBP-2 mRNA was analyzed in animals on the four diets.(ABSTRACT TRUNCATED AT 400 WORDS)
145 citations
TL;DR: Increased levels of supplemental protein increased intake and utilization of dormant tallgrass-prairie forage and increasing supplemental energy without adequate protein availability was associated with depressed intake and digestibility.
Abstract: Three experiments were conducted to evaluate effects of supplemental protein vs energy level on dormant forage intake and utilization In Exp 1, 16 ruminally cannulated steers were blocked by weight (avg wt = 242 kg) and assigned randomly to a negative control or to one of three isocaloric supplement treatments fed at 4% BW: 1) control, no supplement (NS); 2) 12% CP, low protein (LP); 3) 28% CP, moderate protein (MP); 4) 41% CP, high protein (HP) In Exp 2 and 3, 16 ruminally cannulated steers were blocked by weight (avg wt = 332 kg, Exp 2; 401 kg, Exp 3) and assigned randomly to a 2 x 2 factorial arrangement of treatments The treatments contrasted low (LP) and high (HP) levels of supplemental protein (66 g CP/kg BW vs 132 g CP/kg BW) with low (LE) and high (HE) levels of supplemental ME (92 kcal/kg BW vs 184 kcal/kg BW) In Exp 1, forage DMI as well as ruminal DM and indigestible ADF fill at 4 h postfeeding were greater (P less than 10) with the MP and HP steers than with control and LP steers Total DM digestibility increased (P less than 10) for supplemented steers (355% for control vs 473 for supplemented steers); however, LP depressed (P less than 10) NDF digestibility In Exp 2, forage DMI, indigestible ADF flow and liquid flow were depressed (P less than 10) in LP-HE supplemented steers In Exp 3, HP steers had greater (P less than 10) forage DMI, indigestible ADF fill values (4 h postfeeding), liquid volume and tended (P = 11) to have greater ruminal DM fill (4 h postfeeding) In summary, increased levels of supplemental protein increased intake and utilization of dormant tallgrass-prairie forage (less than 3% CP) Increasing supplemental energy without adequate protein availability was associated with depressed intake and digestibility
142 citations
TL;DR: Patients with CRF can activate appropriate adaptive responses to LP inasmuch as reduced amino acid oxidation occurring with feeding and estimates of protein balance did not differ from control.
Abstract: In normal subjects, short to intermediate responses to dietary protein restriction include decreased amino acid oxidation and protein degradation plus increased utilization of amino acids for protein synthesis; these responses are activated to improve amino acid utilization and nitrogen balance. To assess whether chronic renal failure (CRF) impairs the adaptive responses to a low-protein diet, we measured nitrogen balance and the kinetics of infused L-(15N,1-13C)leucine during fasting and feeding. In six adult CRF and four control (C) subjects, 0.6 (LP) and 1.0 (HP) g protein kg-1 day-1 diets were compared. LP reduced feeding stimulated oxidation of leucine by 26% in CRF and 33% in C (P = NS). During fasting, oxidation was unaffected by diet or CRF. For both groups, feeding suppressed protein degradation to the same extent; leucine incorporation into protein did not change. Nitrogen balance during the two diets was the same with C and CRF, as was protein balance estimated from results of measured leucine kinetics. Thus, patients with CRF can activate appropriate adaptive responses to LP inasmuch as reduced amino acid oxidation occurring with feeding and estimates of protein balance did not differ from control.
128 citations
TL;DR: The role of emulsifiers in food emulsions is twofold: first, to reduce the interfacial tension of the oil/water interface and facilitate the formation of large surface area and second, to form an interfacial film to protect the droplets from coalescence as discussed by the authors.
Abstract: Publisher Summary This chapter discusses physicochemical principles and factors involved in emulsion stabilization with particular reference to the role of food emulsifiers. The improvement of emulsion stability by the modification of natural emulsifiers and some of the techniques for determining emulsion stability are discussed in the chapter. The role of emulsifiers in food emulsions is twofold: first, to reduce the interfacial tension of the oil/water interface and facilitate the formation of large surface area and second, to form an interfacial film to protect the droplets from coalescence. The small-molecule emulsifiers are particularly efficient in reducing oil/water interfacial tension, but the film formed from these is usually unstable. Proteins, though less efficient in reducing interfacial tension, can form strong cohesive films. Food emulsions usually contain a combination of small- and macro-molecular emulsifying agents to help both formation and stabilization. Most studies on model systems have been done at relatively low protein concentrations. The interfacial thickness, protein load, and so on may be different at higher protein concentrations.
103 citations
TL;DR: The effect of dietary nucleotides on intestinal weight and length, gut mucosal weight, intestinal protein and DNA contents, and lactase, maltase, and intestinal mucosal activities was assessed in a controlled way.
Abstract: Nucleic acid synthesis in tissues of rapid growth is preferentially done using dietary purines and pyrimidines via the salvage pathway. In the case of a low protein intake, dietary nucleotides may be semiessential for cell replication of gut, lymphocytes, and bone marrow, and especially in those intestinal diseases in which the mucosa is altered, dietary nucleotides may have a role in intestinal development. The effect of dietary nucleotides on intestinal weight and length, gut mucosal weight, intestinal protein and DNA contents, and lactase, maltase, and intestinal mucosal activities was assessed in a controlled way. Weanling (21-day-old) rats were separated into two groups of 36, each receiving blindly a basal diet containing glucose polymers (C) or a basal diet with lactose as the main carbohydrate (L) for 15 days. Those fed with L developed a syndrome of chronic diarrhea and malnutrition. Ten rats of each group were sacrificed at that time. The rest of the animals of each group were separated into two subgroups. The first was fed with the C diet and the second with the C diet supplemented with 50 mg/100 g of each of the following nucleotides: AMP, GMP, CMP, UMP, and IMP (CN). Thus the subgroups CC, CN, LC, and LN were formed. Rats were sacrificed after 4 weeks and gut separated into three segments corresponding to duodenum, jejunum, and ileum. Analysis of variance was used to compare the effect of diet or segments. DNA and lactase, maltase, and sucrase activities increased in the LN group with respect to LC especially in jejunum and ileum but there were not any differences between CC and CN.(ABSTRACT TRUNCATED AT 250 WORDS)
102 citations
TL;DR: Differences in egg quality within and between populations of Arbacia lixula were investigated in the laboratory and may have been due to differences in the abundance of different algal species in the two localities and consequently the diet of sea urchins.
97 citations
TL;DR: Although there were some differences between the three treatments in the proximate composition of gonads, liver, and gastrointestinal tract during the reproductive cycle, no consistent pattern was seen and Dietary treatment did not have any effect on the histomorphology of ovarian development.
TL;DR: In conclusion, beef cow BC and BW losses during the winter grazing period were minimized with increasing supplemental CP concentration and intake and utilization of dormant forage by steers were improved with moderate levels of CP in the supplement.
Abstract: Two experiments were conducted to evaluate the influence of supplemental protein concentration on the intake and utilization of dormant range forage by beef cattle. In Exp. 1,97 pregnant Hereford x Angus cows (avg wt = 454 kg) were assigned randomly to three isocaloric treatment supplements: 1) low protein (LP), 13% CP; 2) moderate protein (MP), 25% CP; and 3) high protein (HP), 39% CP. In Exp. 2, 15 ruminally and 12 esophageally cannulated steers (avg wt = 319 and 355 kg, respectively) were assigned randomly to LP, MP and HP treatments and were used in a 22-d winter grazing trial to evaluate forage intake and utilization characteristics. In Exp. 1, cow body condition (BC) and BW changes responded in linear (P less than .01) and quadratic (P less than .01) fashions to increasing protein concentration, with MP and HP displaying the least BC and BW loss from trial initiation (d 1) through d 84. From d 84 to calving (avg calving date = d 120), only the HP supplement continued to be effective in minimizing BC loss (P less than .01). Calf birth weight tended (P = .17) to increase in a linear fashion to increasing supplemental protein concentration, but calf ADG and cow reproductive efficiency were unaffected (P greater than .10). In Exp. 2, forage OM intake responded in a quadratic fashion (P less than .10), with the MP treatment having the highest NDF digestibility and ruminal OM fill. In conclusion, beef cow BC and BW losses during the winter grazing period were minimized with increasing supplemental CP concentration. Intake and utilization of dormant forage by steers were improved with moderate (26%) levels of CP in the supplement.
23 Mar 1990
TL;DR: In this paper, the effect of low-protein, amino acid-supplemented diets during growing and laying periods on performance of a commercial strain of White Leghorn chickens was investigated.
Abstract: An experiment was conducted to determine the effect of feeding low-protein, amino acid-supplemented diets during growing and laying periods on performance of a commercial strain of White Leghorn chickens. The birds of the positive control were fed diets in a sequence of 20, 16, and 14% protein during 0 to 6, 6 to 12, and 12 to 18 wk (growing period) and of 18, 16.5, and 15% protein during 18 to 34, 34 to 50, and 50 to 66 wk of age (laying period). The birds of the negative control were fed protein levels of 16, 13.5, and 11.5% in the growing period and 14, 13, and 12% in the laying period. Other groups were fed the negative control series supplemented with methionine, methionine plus lysine, or methionine plus lysine plus other deficient essential amino acids. An additional group was fed the negative control supplemented with methionine plus lysine during the growing period and a protein sequence of 15, 14, and 13% supplemented with methionine and lysine during the laying period. At 18 wk of age, birds fed the negative control supplemented with methionine plus lysine or methionine plus lysine plus other deficient essential amino acids had comparable body weight to those fed the positive control despite significantly lower protein and lysine intake. Overall egg production and egg weight of birds fed the sequence of 14, 13, and 12% protein supplemented with combination of methionine, lysine, and extra levels of tryptophan and isoleucine or of the birds fed the sequence of 15, 14, and 13% protein supplemented with methionine and lysine were not different from those fed the positive control. However, egg mass and body weight were inferior to those of birds fed the positive control.
TL;DR: Cells in serum‐free media showed a decrease in antibody productivity, and it completely disappeared in IMDM‐based low protein medium, but this loss of antibody productivity was not observed when the cells were immobilized in alginate beads, and in fact, immobilization enhanced the specific MAb productivity.
Abstract: Hybridoma cells (S3H5/gamma2bA2) were cultivated in spinner flasks with 1% serum media and serum-free media. Monoclonal antibody productivity was maintained in 1% serum media. However, cells in serum-free media showed a decrease in antibody productivity, and it completely disappeared in IMDM-based low protein medium. This loss of antibody productivity was not observed when the cells were immobilized in alginate beads. In fact, immobilization enhanced the specific MAb productivity.
TL;DR: It is concluded that Cd2+ uptake by the tubular epithelial cells is rapid and independent of specific cell surface interactions, whereas uptake by rat mesangial cells follows binding to a specific surface ligand saturating at about 1.5 x 10(7) copies/cell.
TL;DR: Reducing the minimum EAA requirements in proportion to the reduction in CP failed to correct the difference in performance between the high and low CP diets, and glutamic acid was added to provide the amino nitrogen equivalent of 23% protein.
TL;DR: It is concluded that a rapid depression of basal metabolic rate and extensive blubber catabolism enable grey seal pups to endure prolonged periods of fasting without any apparent signs of discomfort or stress.
Abstract: Grey seal pups (Halichoerus grypus) were collected at the time of weaning (mid-October) and fasted for 52 days at thermoneutrality in separate cages. Body weight decreased exponentially, while metabolic rate dropped 45% from an average of 2.95 +/- 0.15 (SEM) W kg-1 at day 2 of fasting to a stable level of 1.62 +/- 0.06 (SEM) W kg-1 from day 10 to day 47 of fasting. Respiratory quotient was low, indicating extensive catabolism of triglycerides, while plasma cortisol was fairly stable at 110 +/- 8 (SEM) nmol l-1 throughout the fasting period. Daily urinary output decreased from 236 +/- 20 (SEM) ml day-1 at day 2 to a stable value of 87 +/- 6 (SEM) ml day-1 between days 8 and 50 of fasting. The urine was analysed for urea, uric acid, creatinine, ammonia, total nitrogen and osmolality. Urea was always the principal excretory end-product, amounting to between 70 and 80% of the total excreted nitrogen. The urine was moderately concentrated (range 770-1300 mosmol kg-1). Total excreted urinary nitrogen decreased by 68% from 3.7 +/- 0.7 (SEM) g day-1 to 1.2 +/- 0.4 (SEM) g day-1 between days 2 and 50. The urinary nitrogen was used to calculate the daily amount of protein being oxidized and its energy content was compared with the measured basal metabolic rate of individual animals. Approximately 6% of the energy expended by grey seal pups during the post-weaning fast is derived from oxidation of protein. It is concluded that a rapid depression of basal metabolic rate and extensive blubber catabolism enable grey seal pups to endure prolonged periods of fasting without any apparent signs of discomfort or stress.
TL;DR: In this article, the protein content of human urine is only 1% that of male rat urine, while the analogous fraction of rat urine containing αG, contained 26% of total urinary protein, and at pH 5.0, the most cationic fraction of human urinary protein constituted only about 4% of the total protein.
TL;DR: The effects of dietary protein and converting enzyme inhibition (CEI) on chronic puromycin aminonucleoside nephropathy (PAN) were studied and proteinuria decreased to group 2 levels, while in group 3B the decrease was slower but still prominent.
TL;DR: It is suggested that feeding a LoNa diet may be beneficial in terms of early growth restriction for chickens and turkeys, however, the recovery of BW appears to be more complete when a controlled, early feed restriction is employed.
TL;DR: Grain protein concentration and grain yield data were collected from eleven Interstate Wheat Variety Trials (IWVT) and other sources and the level of variation in grain protein concentration beyond that attributable to covariation in environment and yield was estimated using a generalized linear model.
Abstract: Grain protein concentration and grain yield data were collected from eleven Interstate Wheat Variety Trials (IWVT) and other sources. The level of variation in grain protein concentration beyond that attributable to covariation in environment and yield was estimated using a generalized linear model. A range of almost 4% in corrected protein concentration was found among 204 lines tested in IWVT. The Western Australian cultivar Tincurrin was approximately 1% lower in grain protein concentration than any other line. Shortim, Sun 43A, QT2200-20, QT26 12- 1 and Sun 92A were all 1.4- 1.7% higher in grain protein concentration than the pooled mean of four check cultivars (Cook, Eagle, Halberd and Oxley). Accessions did not vary significantly in the rate of protein concentration with change in yield. Results from a range of other independent trials confirmed those from IWVT. Wheats genetically capable of producing a higher concentration of protein in their grain at a given yield level came principally from the Sydney University and Queensland breeding programmes, those producing a lower concentration principally from Victoria and Western Australia. Grain hardness was independent of grain protein concentration and many low protein hard wheats entering the IWVT fell well outside current international market requirements.
TL;DR: A disk test is being developed to assess whether fungal isolates are sensitive to therapeutically achievable levels of drug, because the excellent efficacy of fluconazole in vivo despite its low activity in vitro has caused confusion.
Abstract: Fluconazole is polar, soluble in water, and metabolically stable and exhibits low protein binding. In contrast, other systemic azoles are lipophilic, metabolically vulnerable compounds with high protein binding and negligible solubility in water. The physical and pharmacokinetic properties of these drugs plus their inherent antifungal potency determine their efficacy. Although fluconazole is less active than ketoconazole in vitro, its distribution throughout the body and the high levels of free drug reached in the blood contribute to and are of value in predicting its efficacy. Even for ketoconazole the levels of free drug in blood may be indicative of efficacy. For very lipophilic agents (itraconazole), blood levels of drug are very low, and organ levels may correlate better with efficacy, although tissue binding will be high and total drug levels in an organ may be misleading indicators of efficacy. The excellent efficacy of fluconazole in vivo despite its low activity in vitro has caused confusion. Consequently, a disk test is being developed to assess whether fungal isolates are sensitive to therapeutically achievable levels of drug.
Patent•
30 Nov 1990TL;DR: In this article, a porous polymeric medium having a low affinity for amide group-containing and adjuvant-containing materials is provided comprising a polyvinylidene difluoride substrate and a surface-modifying polymeric material, which is formed from a monofunctional monomer having at least one hydroxyl group.
Abstract: A porous polymeric medium having a low affinity for amide group-containing and adjuvant-containing materials is provided comprising a porous polyvinylidene difuoride substrate and a surface-modifying polymeric material having a low affinity for amide group-containing materials formed in situ at and covalently bonded to the surface of the porous polyvinylidene difluoride substrate, the surface-modifying polymeric material being formed from a monofunctional monomer having at least one hydroxyl group. Another embodiment that provides a porous polymeric medium having a low affinity for amide group-containing materials employs a supplemental monomer in combination with the monofunctional monomer having at least one hydroxyl group to form the surface-modifying polymeric material. The supplmental monomer or comonomer used is one which, when formed as a homopolymer, has a high affinity for amide group-containing materials.
TL;DR: Competition among amino acids for uptake into brain appears to be involved in the feeding response of the rat to dietary disproportions of amino acids, but this response is not directly related to changes in brain concentrations of serotonin and 5-HIAA.
Abstract: Food intake, growth, plasma and brain amino acid, and brain serotonin and 5-hydroxyindole-3-acetic acid (5-HIAA) concentrations were measured in rats fed low protein diets containing disproportionate amounts of large neutral amino acids (LNAA) devoid of tryptophan or histidine (tryptophan or histidine imbalance). Five-day food intakes and weight gains of rats fed the imbalanced diets were depressed. The concentration of the limiting amino acid was low in brains of rats fed diets containing LNAA that compete with either tryptophan or histidine for entry into brain. Correlations were observed between the brain concentrations of most individual LNAA and either the ratios of the plasma concentration of that LNAA to the sum of the other LNAA, or the predicted rates of influx of that LNAA. Cumulative food intakes were correlated with brain concentrations of the limiting amino acid, tryptophan or histidine. Food intakes were not consistently correlated with concentrations of serotonin and 5-HIAA because these compounds were altered only in brains of rats in the tryptophan study. Competition among amino acids for uptake into brain appears to be involved in the feeding response of the rat to dietary disproportions of amino acids, but this response is not directly related to changes in brain concentrations of serotonin and 5-HIAA.
TL;DR: Isoquant analysis showed that dietary protein and ration size are substitute inputs within a certain range, implying that the same harvest weight can be obtained by feeding low protein diets at high rations or highprotein diets at low rations.
TL;DR: The present case demonstrates that protein C levels lower than 10% are compatible with a negative history for thrombosis, not only in the neonatal period but also during adulthood, and suggests that in some homozygotes other factors need to interact for full clinical penetrance of the defect.
Abstract: We report a family in which 2 homozygotes with similarly very low protein C levels have different clinical symptoms. One had recurrent venous thrombosis starting at the age of 28 years, the other is still asymptomatic at 38 years despite exposure to thrombotic risk factors. Our review of 13 additional cases reveals a highly variable phenotypic expression of homozygous protein C deficiency, which can be subdivided into two groups. In the first group are 8 kindreds in which homozygotes presented at birth with unmeasurable protein C levels and life-threatening thrombosis and 1 kindred in which homozygotes are characterized by very low levels of protein C but delayed onset (10 months of age) of thrombosis. In the second group are 4 kindreds characterized by very low, but measurable, protein C levels in homozygotes who survived beyond the neonatal period into adulthood with histories of moderately severe thrombosis. The present case demonstrates that protein C levels lower than 10% are compatible with a negative history for thrombosis, not only in the neonatal period but also during adulthood, and suggests that in some homozygotes other factors need to interact for full clinical penetrance of the defect.
TL;DR: Improving amino acid balance by adding essential amino acids to low-protein diets did not benefit performance beyond that of a typical corn-soybean meal diet.
Abstract: Five experiments, using 216 barrows and gilts (initial weight 19.9 to 23.7 kg), were conducted to evaluate the effects of improving amino acid balance by supplementing low-protein corn-soybean meal diets with essential amino acids. Three experiments were growth studies lasting approximately 3 wk, and the other two were 4-d metabolism trials. The control diets in each of the experiments were formulated to contain .80% lysine and contained approximately 17% CP. The other diets were formulated from a basal diet containing a 10.9% CP, fortified corn-soybean meal mixture, which included crystalline L-lysine.HCI, L-tryptophan, L-threonine, L-isoleucine, DL-methionine and L-valine to correct amino acid deficiencies. Nonessential N (glutamic acid or urea) also was added to some of the diets to increase the CP equivalent to 12 or 13%. Supplemental K (as a salt of bicarbonate or glutamate) was included in selected diets to increase the K concentration to the same level as that of the control diet. Growth rate of pigs fed the basal diet was similar (P greater than .05) to that of the control diets in only one growth study. Added glutamic acid and urea did not improve either growth rate or N retention. Added K improved K digestibility but did not increase K retention, N retention or growth rate. Improving amino acid balance by adding essential amino acids to low-protein diets did not benefit performance beyond that of a typical corn-soybean meal diet. Under our conditions, K, N, and nonessential N were not limiting.
TL;DR: Moderate to low activities of Quinone reductase and glutathione transferase are the systems of importance in detoxification of juglone, and moderate to low Activities of these enzymes may explain why gypsy moths perform poorly on members of the Juglandaceae.
Abstract: The individual and interactive effects of dietary protein and juglone on larval performance and midgut detoxification enxymes were investigated for the gypsy moth,Lymantria dispar. The experimental design was a 2 × 3 factorial, with two levels of protein and three levels of juglone. We monitored survival/development rates from egg hatch to pupation and conducted fourth-instar feeding trials for determination of nutritional indices. Enzyme solutions were prepared from midguts of fifth instars and assayed for polysubstrate monooxygenase, esterase, quinone reductase, and glutathione transferase activities. Results showed that low protein levels prolonged development times, increased consumption rates, and reduced pupal weights. Juglone markedly reduced survival, growth, and consumption rates, increased development times, and reduced pupal weights. The interaction between protein and juglone influenced larval digestion efficiencies and female pupal weights. Polysubstrate monooxygenase activities were unaffected by diet, whereas esterase activities increased in response to both low dietary protein and presence of juglone. Low protein levels increased soluble quinone reductase activities but decreased glutathione transferase activities. Glutathione transferase activities were lowest in larvae fed low-protein, high-juglone diets and may have contributed to the especially poor performance of larvae on those diets. Quinone reductase and glutathione transferase are the systems of importance in detoxification of juglone, and moderate to low activities of these enzymes may explain why gypsy moths perform poorly on members of the Juglandaceae.
TL;DR: Active stage of cryptococcal meningitis does not contraindicate the necessity of shunting, and premedication with antifungal drugs is unnecessary, and no shunt-related morbidity and mortality was seen in this study.
TL;DR: Two mutated MalT proteins were purified and examined for in vitro activation of the MalT-dependent malPp promoter and exhibited a fivefold-higher affinity for maltotriose than the wild-type protein did.
Abstract: The expression of the maltose regulon of Escherichia coli is controlled by a transcriptional activator, the product of the malT gene, and is induced by the presence of maltose or maltodextrins in the growth medium. We isolated eight mutants with mutations in malT which lead to constitutive expression of the regulon. The nucleotide sequences of the mutated genes revealed that the eight mutations are clustered in two small regions in the first one-third of the malT gene. Two mutated MalT proteins (corresponding to a mutation in each cluster) were purified and examined for in vitro activation of the MalT-dependent malPp promoter. Whereas wild-type MalT activity was absolutely dependent upon the presence of maltotriose, even at high protein concentrations, both mutated proteins were partially active in the absence of this sugar. Indeed, while the activity of the mutated proteins was still increased by maltotriose at low protein concentrations, the proteins were fully active in the absence of maltotriose at high protein concentrations. Both proteins exhibited a fivefold-higher affinity for maltotriose than the wild-type protein did. Images