Showing papers on "Low protein published in 1997"
15 Jan 1997
TL;DR: Light microscopy has confirmed that the visually observable extent of reversible depletion flocculation in concentrated emulsions of this type is very sensitive to overall protein content.
Abstract: The influence of protein content on the stability of concentrated oil-in-water emulsions (35 or 45 vol% oil, droplet diameter ∼0.5 μm, pH 6.8) containing sodium caseinate as the sole emulsifying agent has been investigated. Time-dependent creaming profiles were determined at 30°C using an ultrasound velocity scanning technique with data analysis based on a Urick equation renormalization technique. The results indicate that creaming kinetics has a complex dependence on caseinate content. At low protein content (1 wt%), corresponding to less than half that required for saturation monolayer coverage, the emulsion is destabilized by bridging flocculation (accompanied by some coalescence). At higher protein content (2 wt%), where individual droplets are fully protected against protein bridging or coalescence by the thick adsorbed protein layer, the unflocculated emulsion has good stability over a period of several weeks. With further increase of protein content (≥3 wt%), the observed creaming stability is reduced again, with the rate of serum separation at the bottom of the sample now greatly increased. This is attributed here to depletion flocculation by unadsorbed caseinate, probably in the form of small particles called “casein submicelles.” Light microscopy has confirmed that the visually observable extent of reversible depletion flocculation in concentrated emulsions of this type is very sensitive to overall protein content. Once the caseinate concentration reaches a high value (6 wt%), the strength of the depletion interaction is such that it produces a very strong emulsion droplet network which can reorganize only slowly, and is hence much more stable to creaming and serum separation.
245 citations
TL;DR: There is a high prevalence of unrecognized mental impairment among hemodialysis patients that has adverse implications for protein nutritional status, staff time, and hospitalization, and clinicians routinely screen for mental impairment and target impaired patients for interventions to improve mental status and associated adverse outcomes.
237 citations
TL;DR: This work has investigated the potential of successfully refolding reduced and denatured hen egg white lysozyme at high concentrations (1 and 5 mg/mL) and found optimum conditions which kinetically favor proper folding over inactivation were found.
Abstract: Newly synthesized cloned gene proteins expressed in bacteria frequently accumulate in insoluble aggregates or inclusion bodies. Active protein can be recovered by solubilization of inclusion bodies followed by renaturation of the solubilized (unfolded) protein. The recovery of active protein is highly dependent on the renaturation conditions chosen. The renaturation process is generally conducted at low protein concentrations (0.01-0.2 mg/mL) to avoid aggregation. We have investigated the potential of successfully refolding reduced and denatured hen egg white lysozyme at high concentrations (1 and 5 mg/mL). By varying the composition of the renaturation media, optimum conditions which kinetically favor proper folding over inactivation were found. Solubilizing agents such as guanidinium chloride (GdmCl) and folding aids such as L-arginine present in low concentrations during refolding effectively enhanced renaturation yields by suppressing aggregation resulting in reactivation yields as high as 95%. Quantitatively the kinetic competition between lysozyme folding and aggregation can be described using first-order kinetics for the renaturation reaction and third-order kinetics for the overall aggregation pathway. The rate constants for both reactions have been found to be strongly dependent on denaturant and thiol concentration. This strategy supercedes the necessity to reactivate proteins at low concentrations using large renaturation volumes. The marked increase in volumetric productivity makes this a viable option for recovering biologically active protein efficiently and in high yield in vitro from proteins produced as inclusion bodies within microbial cells.
236 citations
TL;DR: Perfused livers of 48-h- starved adult offspring of rat dams fed 8% protein diets during pregnancy and lactation produced more glucose from 6 mM lactate than did control livers from rats whose dams were fed 20% protein.
Abstract: Maternal protein restriction is a model of fetal programming of adult glucose intolerance. Perfused livers of 48-h- starved adult offspring of rat dams fed 8% protein diets during pregnancy and lactation produced more glucose from 6 mM lactate than did control livers from rats whose dams were fed 20% protein. In control livers, a mean of 24% of the glucose formed from lactate in the periportal region of the lobule was taken up by the most distal perivenous cells; this distal perivenous uptake was greatly diminished in maternal low protein (MLP) livers, accounting for a major fraction of the increased glucose output of MLP livers. In control livers, the distal perivenous cells contained 40% of the total glucokinase of the liver; this perivenous concentration of glucokinase was greatly reduced in MLP livers. Intralobular distribution of phosphenolpyruvate carboxykinase was unaltered, though overall increased activity could have contributed to the elevated glucose output. Hepatic lobular volume in MLP livers was twice that in control livers, indicating that MLP livers had half the normal number of lobules. Fetal programming of adult glucose metabolism may operate partly through structural alterations and changes in glucokinase expression in the immediate perivenous region.
233 citations
TL;DR: It is speculated that primary, heritable thrombophilia or hypofibrinolysis causesThrombotic venous occlusion in the head of the femur, leading to venous hypertension and hypoxic death of bone (osteonecrosis).
Abstract: In 31 patients with osteonecrosis (primarily of the hip), 74% had 1 or more primary coagulation disorders. In 18 patients, 15 (83%) who had coagulation disorders, the osteonecrosis was initially identified as idiopathic and was not associated with known underlying drugs (glucocorticoids) or diseases (alcoholism, sickle cell disease, Gaucher's disease). In 13 patients, 8 (62 %) who had coagulation disorders, the osteonecrosis was initially identified as secondary, and was associated with glucocorticoids in 12 patients, and with alcoholism in 1. The coagulation disorders included thrombhophilia (increased tendency to intravascular thrombosis) and hypofibrinolysis (reduced ability to lyse thrombi). Of the 18 patients initially thought to have idiopathic osteonecrosis, thrombophilia alone was found in 12% (resistance to activated protein C in 6%, low protein C in 6%), hypofibrinolysis alone was found in 50% (high lipoprotein(a) in 44%, low stimulated tissue plasminogen activator activity was found in 6%), and mixed thrombophilia hypofibrinolysis was found in 22%. Resistance to activated protein C was more common in these 18 patients than in healthy controls (11% versus 0%), as was high lipoprotein(a) (67% versus 20%). Of the 13 patients with secondary osteonecrosis, thrombophilia alone was found in 8% (low protein C), hypofibrinolysis alone was found in 30% (high Lp(a) in 15%, low tissue plasminogen activator activity in 15%), and mixed thrombophilia hypofibrinolysis was found in 23%. Low tissue plasminogen activator activity was more common in the 13 patients with secondary osteonecrosis than in controls (27% versus 7%), as was low protein C (23% versus 0%). In aggregate, these findings lead us to the speculation that primary, heritable thrombophilia or hypofibrinolysis causes thrombotic venous occlusion in the head of the femur, leading to venous hypertension and hypoxic death of bone (osteonecrosis).
185 citations
TL;DR: The offspring of mothers fed on a low-protein diet during pregnancy or lactation were significantly more glucose tolerant than controls, suggesting that both time windows can have long-term effects on glucose tolerance.
Abstract: It is becoming well established that poor fetal and early postnatal growth can have long-term effects on adult health, including susceptibility to non-insulin-dependent diabetes mellitus, cardiovascular disease and hypertension. It is suggested that this results from poor nutrition during early life having permanent effects on the structure and metabolism of certain organs and tissues. In the present study we investigated the effect of a low-protein diet during pregnancy and lactation on adipocyte properties and glucose tolerance. Rat dams were fed on a diet containing either 200 (control) or 80 (low protein) g protein/kg during pregnancy and lactation. In addition cross-fostering techniques were employed to enable a separate evaluation of the prenatal and postnatal periods. All offspring were weaned onto a 200 g protein/kg diet at 21 d of age and then studied at 6 weeks of age. The mothers' protein supply during lactation appeared to be the most critical time window for long-term growth. In contrast, the offspring of mothers fed on a low-protein diet during pregnancy or lactation were significantly more glucose tolerant than controls, suggesting that both time windows can have long-term effects on glucose tolerance. In addition offspring of mothers fed on a low-protein diet during pregnancy or lactation had significantly smaller adipocytes than controls. However the largest reduction in adipocyte size was observed when there was a low-protein diet during both pregnancy and lactation. The amount of insulin receptor present in adipocyte membranes was increased in the three animal groups that had been exposed to the low-protein diets while levels of the insulin responsive glucose transporter (GLUT 4) were similar in adipocyte membranes from all groups.
171 citations
TL;DR: Results of this study show that dietary CP can be reduced to 13% in the growing and 12.8% inThe finishing diets of pigs as long as crystalline amino acids are added to match the apparent ileal digestible amino acid ratios in an assumed ideal protein.
Abstract: Seventy-two gilts were used to determine the effect of reducing excess amino acid intake on growing-finishing pig performance. Separate diets were formulated for the growing (20 to 55 kg BW) and finishing (55 to 100 kg BW) periods. For each period, three diets were formulated that varied in total crude protein level and contained similar levels of digestible ideal protein. Crystalline amino acids were added to the low protein diets to overcome potential deficiencies. The grower diets contained .66% apparent ileal digestible lysine and contained 16.6, 15.0, and 13.0% CP, respectively; for the finisher diets, these values were .55% digestible lysine and 14.2, 12.8, and 11.0% CP, respectively. Amino acid analyses and a separate digestibility trial were conducted to confirm digestible amino acid levels in the dietary ingredients. During the growing and the overall growing-finishing period, daily gain, feed intake, and gain:feed were not affected (P > .10) by dietary treatment. Daily gain tended to be lower (P = .06) and gain:feed was poorer (P .10) by dietary treatment. Results of this study show that dietary CP can be reduced to 13% in the growing and 12.8% in the finishing diets of pigs as long as crystalline amino acids are added to match the apparent ileal digestible amino acid ratios in an assumed ideal protein.
165 citations
TL;DR: It is suggested that by adding food early in laying, birds were induced to lay at a less favourable time and/or produced clutches that were too large to care for successfully under normal food condition and might not only energetically restrict laying birds, but also provide clues about future conditions during chick rearing.
Abstract: 1. We tested the hypothesis that protein availability rather than energy availability constrains egg formation in great tits (Parus major L.) by providing them with two food supplements of different protein content in the prelaying and laying period of 1991 and 1992. 2. Timing of breeding, clutch size and egg size did not differ between the two food supplements. Thus, the hypothesis that a low protein content of supplement restricts laying in great tits cannot be supported. 3. Food supplementation, independent of food type and year, led to an advancement of laying by 5.6 days. Average clutch size of supplemented birds, corrected for laying date and year, was 0.55 eggs above the population average. 4. Supplementary fed great tits did not breed more successfully than controls. This suggests that by adding food early in laying, birds were induced to lay at a less favourable time and/or produced clutches that were too large to care for successfully under normal food condition. Thus food early in the season might not only energetically restrict laying birds, but also provide clues about future conditions during chick rearing. 5. The comparison of results of published supplemental feeding experiments shows that the birds responded more strongly to additional feeding in poor environments. Almost two-thirds of the variation in changes of clutch size due to experimental treatment can be explained by year quality. Thus, only in poor environments do reproductive traits seem to be limited by energy availability early in the season, but other factors become more important in good environments [KEYWORDS: clutch size, egg formation, food quality, food supplementation, Parus major]
163 citations
TL;DR: Serum cholesterol and triglyceride were associated with increases in factors VII and IX, as well as antithrombin, protein C and protein S; and with increased fibrinogen and factor VIII in women, apart from factor VIII, which is related to blood pressure in men, but not in women.
Abstract: Coagulation factor activity (fibrinogen, VII, VIII and IX), coagulation inhibitor activity (antithrombin, protein C, protein S), and coagulation activation markers (prothrombin fragment F1, 2; thrombin–antithrombin complexes) were measured in 746 men and 816 women aged 25–74 years, randomly sampled from the north Glasgow population in the Third MONICA Survey. After age-adjustment, significant associations with cardiovascular risk factors were observed. Serum cholesterol and triglyceride were associated with increases in factors VII and IX, as well as antithrombin, protein C and protein S; and with increased fibrinogen and factor VIII in women. Apart from factor VIII (related to blood pressure in men, but not in women), similar associations were observed for blood pressure and body mass index. Smoking status and/or smoking markers were related to fibrinogen, factor IX, antithrombin and protein S. Alcohol intake was related to protein S, and inversely to fibrinogen and antithrombin in men. Low social class was associated with fibrinogen, factor VIII, factor IX, and with antithrombin, protein S, and low protein C in men. Serum vitamin C was associated inversely with coagulation factors and coagulation inhibitors. The only associations of activation markers were with low serum vitamin C, and with alcohol consumption and low social class in men. Prevalent cardiovascular disease was associated only with fibrinogen.
These associations of coagulation factors and inhibitors with cardiovascular risk factors are plausibly relevant to thrombotic risk in cardiovascular disease. In general, ‘worse’ values of risk factors are associated with increased plasma levels of both coagulation factors and inhibitors, without significant increase in coagulation activation markers. However, the association of lower serum vitamin C with increased coagulation activation markers is of potential therapeutic interest.
156 citations
TL;DR: There is little evidence of energy-sparing adaptations in basal metabolic rate or dietary-induced thermogenesis during lactation, although physical activity may be reduced during the early postpartum period.
Abstract: Additional energy needs for an exclusively breastfeeding woman are approximately 670 kcal/day. If one allows for gradual weight loss, the net increment needed is about 500 kcal/day. There is little evidence of energy-sparing adaptations in basal metabolic rate or dietary-induced thermogenesis during lactation, although physical activity may be reduced during the early postpartum period. In women with adequate fat reserves, moderately negative energy balance is not likely to affect lactation. The recommended increment in protein intake during lactation has been estimated to be about 15 g/day, based on a milk protein concentration of 11 g/liter. However, if one takes into account the protein cost of non-protein nitrogen in human milk, the recommended increment in protein is about 20 g/day. The latter value is consistent with data from nitrogen balance studies in lactating women. Low protein intakes are unlikely to affect milk volume but may alter certain fractions of milk nitrogen.
153 citations
TL;DR: Meropenem has excellent penetration in abdominal tissues, bile, blister fluid, inflammatory exudate, cerebrospinal fluid (in the presence of inflammation), gynecologic tissues, respiratory tract tissues, and urinary tract tissues; tissue levels are generally equal to or above the levels needed for the treatment of patients with susceptible pathogens.
Abstract: Meropenem, a new carbapenem antibiotic, is more active against gram-negative bacilli and less active against gram-positive cocci than is imipenem, and there are several important structural differences between meropenem and the older carbapenem. These differences may be responsible for the lower potential for the induction of epileptogenic activity observed with meropenem as well as for its increased stability to degradation by dehydropeptidase-I. The pharmacokinetics of meropenem are typical of those of a parenteral beta-lactam antibiotic with low protein binding and predominantly renal excretion. Dosage reduction is required in patients with reduced renal function; no dosage adjustment is required for patients with hepatic impairment. Meropenem has excellent penetration in abdominal tissues, bile, blister fluid, inflammatory exudate, cerebrospinal fluid (in the presence of inflammation), gynecologic tissues, respiratory tract tissues, and urinary tract tissues; tissue levels are generally equal to or above the levels needed for the treatment of patients with susceptible pathogens.
TL;DR: The influence of different food regimes on the free amino acid (FAA) pool, the rate of protein turnover, the flux of amino acids, and their relation to growth of larval turbot from first feeding until metamorphosis was studied.
Abstract: The present paper studied the influence of different food regimes on the free amino acid (FAA) pool, the rate of protein turnover, the flux of amino acids, and their relation to growth of larval turbot (Scophthalmus maximus L.) from first feeding until metamorphosis. The amino acid profile of protein was stable during the larval period although some small, but significant, differences were found. Turbot larvae had proteins which were rich in leucine and aspartate, and poor in glutamate, suggesting a high leucine requirement. The profile of the FAA pool was highly variable and quite different from the amino acid profile in protein. The proportion of essential FAA decreased with development. High contents of free tyrosine and phenylalanine were found on Day 3, while free taurine was present at high levels throughout the experimental period. Larval growth rates were positively correlated with taurine levels, suggesting a dietary dependency for taurine and/or sulphur amino acids. Reduced growth rates in Artemia-fed larvae were associated with lower levels of free methionine, indicating that this diet is deficient in methionine for turbot larvae. Leucine might also be limiting turbot growth as the different diet organisms had lower levels of this amino acid in the free pool than was found in the larval protein. A previously presented model was used to describe the flux of amino acids in growing turbot larvae. The FAA pool was found to be small and variable. It was estimated that the daily dietary amino acid intake might be up to ten times the larval FAA pool. In addition, protein synthesis and protein degradation might daily remove and return, respectively, the equivalent of up to 20 and 10 times the size of the FAA pool. In an early phase (Day 11) high growth rates were associated with a relatively low protein turnover, while at a later stage (Day 17), a much higher turnover was observed.
TL;DR: In this article, two different reductases were found to be responsible for the synthesis of aldehydes and alcohols in pea leaves, and they were shown to be functionally coupled to the transacylase and decarbonylase.
TL;DR: A transcriptional fusion of the lacZ gene to the AOX1 promoter is used as a model system for investigating recombinant protein production in an alcohol oxidase (aox1, aox2) defective strain to study growth and recombinantprotein production with glycerol as the carbon source.
TL;DR: By investigating the adsorption kinetics of fibrinogen at differently terminated self-assembled monolayers (SAMs) of alkanethiols on thin gold films, it is demonstrated that acoustic plate-mode sensors are a promising analytical tool for studying the adsorbent of proteins.
Abstract: A detailed understanding of the interaction of proteins with artificial surfaces is essential for many applications in medicine and biochemistry. The affinity of surfaces toward proteins may, for instance, remove pharmacological proteins from media or control the adherence of pathogenic bacteria to protheses. Only a few analytical techniques now exist that can be used to study the binding process in real time, using unlabeled proteins. By investigating the adsorption kinetics of fibrinogen at differently terminated self-assembled monolayers (SAMs) of alkanethiols on thin gold films, it is demonstrated that acoustic plate-mode sensors are a promising analytical tool for studying the adsorption of proteins. In agreement with previous studies for fibrinogen, it is shown in situ that hexa(ethylene glycol)-terminated SAMs (HS(CH2)11(OCH2CH2)6OH) exhibit very low protein adsorption and that methyl-terminated SAMs (HS(CH2)11CH3) tend to adsorb large amounts of protein nonspecifically. The observed adsorption kin...
TL;DR: There was a strong negative correlation between protein retention per g of lysine consumed andLysine: CP ratio, suggesting that response to a limiting amino acid was improved by the presence of a super-abundance of other amino acids.
Abstract: 1. An experiment was performed with growing broiler chickens (14 to 21 d old) to examine 3 diet characteristics which have been implicated in regulatory elevation of metabolic rate: an imbalanced amino acid mixture, high dietary energy concentration and low protein concentration. 2. Differences in energy expenditure could be explained almost entirely (93%) by differences in quantities, and therefore costs, of protein and fat accretion. There was no indication of regulatory diet-induced thermogenesis. Heat production was not significantly correlated with CP:TME ratio and was negatively correlated (P < 0.01) with dietary TME concentration. 3. Heat production was closely correlated (P < 0.001) with rate of protein accretion, which in turn was more strongly associated with intake of the first-limiting amino acid (lysine) than with total protein intake. Heat production on an imbalanced, lysine-limited, amino acid mixture was no greater than on a balanced amino acid source with the same lysine concentration. 4. There was no indication of a stimulation of heat production by excess amino acids. Heat production, adjusted for body weight by covariance analysis, was similar on paired diets which had identical lysine concentrations but a 1.5- or 2-fold difference in crude protein concentration. 5. There was a strong negative correlation (P < 0.001) between protein retention per g of lysine consumed and lysine: CP ratio, suggesting that, in this case, response to a limiting amino acid was improved by the presence of a super-abundance of other amino acids.
TL;DR: The association of increased leptin with low protein intake and loss of lean tissue is consistent with leptin contributing to malnutrition but a definitive role cannot be substantiated by this study.
Abstract: into dialysis fluids, and particularly reduced food Methods. Plasma leptin was measured by radio- intake due to anorexia, nausea, and vomiting. immunoassay in 93 individuals in groups of undialysed, The obesity gene protein, now known as leptin, with peritoneal dialysed, and haemodialysed patients and a molecular weight of 16 kDa, was first cloned in 1994 controls. Body composition was determined by DEXA. [5]. Recent studies have shown that leptin has an Results. Protein-energy malnutrition was evident in endocrine function for lowering food intake and regunon-dialysed and dialysed patients from low lean or lating body composition [6‐8 ] and is produced exclusfat tissues, plasma albumin and transferrin. A third of ively in fat cells from animals and humans. In humans, the dialysis patients were eating less than prescribed leptin correlates with percentage body fat but obese intakes. Leptin relative to total fat mass (ng/ml/kg) persons are insensitive to this endogenous leptin prowas significantly greater for patients than for controls, duction [9 ]. Leptin resistence in obesity is probably particularly the dialysed patients. Leptin was highly due to a reduced eYciency of brain leptin delivery correlated with total, arm, leg, and all other fat meas- [10,11]. urements, e.g. r for leptin vs% total fat was: undialysed A recent study in this unit investigated total and 0.88, PD 0.81, HD 0.93, and controls 0.83 (P<0.0001 regional body composition in undialysed and dialysed for all ). Dialysis patients with the highest leptin/fat patients with CRF and controls [12 ]. The patients had mass ratio had low protein intakes and significantly significant lean tissue depletion together with lower lower lean tissue mass. Leptin/fat ratio correlated percentage of body fat than controls. The aim of this inversely with dietary intake e.g. with protein intake study was to measure plasma leptin in these subjects in g/day and marginally in g/kg of ideal weight/day. to establish whether leptin concentrations, or their Leptin concentration was unrelated to plasma creatin- relationship with body composition and dietary intake, ine or residual renal function or to the protein ‘nutri- could account for any loss of appetite or the incidence tional indices’, albumin and transferrin. of malnutrition. Conclusions. Our data suggests that leptin is markedly increased in some patients with chronic renal failure. The association of increased leptin with low protein Subjects and methods intake and loss of lean tissue is consistent with leptin contributing to malnutrition but a definitive role Ninety-three individuals were investigated: 11 female and 12 cannot be substantiated by this study.
TL;DR: Fetal exposure to carbenoxolone at any period in gestation resulted in lower weight at birth and increased fetal exposure to maternal glucocorticoids impairs fetal growth and elevated blood pressure in later life.
Abstract: 1. In the rat low birthweight and raised systolic blood pressure are the consequence of fetal exposure to maternal low protein diets. Nutritional down-regulation of the placental isoform of 11β-hydroxysteroid dehydrogenase, which may increase exposure of the fetus to maternal glucocorticoids, has been suggested to underlie effects of low protein diets on fetal growth and blood pressure. 2. Pregnant rats were fed control (18% casein) or low protein (9% casein) diets throughout gestation. Animals fed the control diet were injected with carbenoxolone, an inhibitor of 11β-hydroxysteroid dehydrogenase. Injections were administered either throughout pregnancy (days 0–22), or targeted to specific periods in early (days 0–7), mid- (days 8–14) or late (days 15–22) gestation. 3. Exposure to a low protein diet reduced birthweight and at 4 weeks of age systolic blood pressure was significantly elevated in the rats exposed to low protein. These hypertensive animals had small kidneys in proportion to body weight. 4. Fetal exposure to carbenoxolone at any period in gestation resulted in lower weight at birth. In rats exposed to the inhibitor over days 8–14, 15–22 or 0–22 systolic blood pressure at 4 weeks was significantly higher than in control animals. The greatest elevation of pressure was associated with carbenoxolone treatment in late (days 15–22) gestation. Animals with carbenoxolone-induced hypertension did not exhibit evidence of retarded renal growth. 5. Increased fetal exposure to maternal glucocorticoids impairs fetal growth and programmes elevated blood pressure in later life.
TL;DR: The theory that early development profoundly affects the structure of the pancreas and may play a role in the later development of adult diseases, such as non‐insulin‐dependent diabetes mellitus, is supported.
Abstract: There is evidence that low birth weight and poor growth in early life cause a long-term predisposition to non-insulin-dependent diabetes. Morphological changes were assessed in fetal rat pancreas subjected to both pre- and post-natal maternal protein deprivation (LP). Further groups were subjected to purely prenatal maternal protein deprivation (preLP) and purely postnatal maternal protein deprivation (postLP), as well as a control group. The results show that the LP and postLP groups had fewer but larger islets than the control group, while the preLP group had more numerous, smaller islets. All three low protein groups had more irregularly shaped islets than the control group. There was a reduction in the amount of beta cells within each islet in all three protein-deprived groups. The LP and postLP groups showed a reduction in the percentage of islet tissue and beta cells per pancreas, but the percentage of islet tissue expressed per unit body weight was similar in all four groups. These results show that in maternal protein deprivation, homeostatic mechanisms ensure a constant amount of pancreatic endocrine tissue per unit of body weight. However, there remain major structural changes in the size, shape, and composition of the islets. These results support the theory that early development profoundly affects the structure of the pancreas and may play a role in the later development of adult diseases, such as non-insulin-dependent diabetes mellitus.
TL;DR: In the current in vitro study, a poloxamer 407 (22% wt/wt) matrix could be prepared containing tens of milligrams/mililiter of the model proteins alpha-chymotrypsin and lactate dehydrogenase, and protein stability during incubation at 37 degrees C was greatly improved over that seen at lower protein concentrations.
TL;DR: It is revealed that chronic low dietary energy intake by long-term castrates, with high or low protein intake, reduces LH pulse frequency but increases the circulating levels of LH by virtue of an increase in pulse amplitude, and concomitantly increases hypothalamic NPY gene expression.
Abstract: Castrate male sheep (wethers, average liveweight 38 +/- 0.6 kg) were given one of the following diets for 10 weeks followed by euthanasia (n = 8/group): high-energy high-protein providing 1-5 times the energy required to maintain liveweight (maintenance) (group 1.5 M), low-energy low-protein at 0.5 maintenance (0.5 M), or low-energy high-protein at 0.5 maintenance (0.5 M + P). 1.5 M wethers gained 22% liveweight whereas 0.5 M and 0.5 M + P wethers lost 18 and 13% liveweight respectively. Relative to the 1.5 M group, the 0.5 M and 0.5 M + P groups had similar plasma concentrations of glucose and cortisol throughout, but elevated non-esterified fatty acids (P < 0.001) and reduced IGF-I and insulin (P < 0.05, 0.01 or 0.001) from 1 week onwards. Each week blood samples were taken every 12 min for 4 h and plasma assayed for LH. Mean concentration over 4 h, LH pulse frequency and LH pulse amplitude showed no progressive change in 1.5 M sheep. However, in both 0.5 M and 0.5 M + P groups mean LH increased (P < 0.001 and P < 0.01 respectively), pulse frequency decreased (P < 0.01 and P < 0.01) and pulse amplitude increased (P < 0.001 and P < 0.01) over the 10-week period. Anterior pituitary. LH content was greater in 0.5 M (P < 0.01) and 0.5 M + P (P < 0.05) than in 1.5 M sheep. Coronal sections (20 microns) of hypothalamic brain tissue were subjected to in situ hybridisation to determine gene expression for neuropeptide Y (NPY). NPY mRNA was concentrated in the arcuate nucleus and median eminence, with total amounts greater in both 0.5 M (310%, P < 0.001) and 0.5 M + P (333%, P < 0.01) groups than in 1.5 M sheep (100%). These data reveal that chronic low dietary energy intake by long-term castrates, with high or low protein intake, reduces LH pulse frequency but increases the circulating levels of LH by virtue of an increase in pulse amplitude, and concomitantly increases hypothalamic NPY gene expression.
TL;DR: In this article, the authors found specific correlations between dietary protein, amino acids, and increasing environmental temperatures for broilers, and fed a series of 3250 kcal ME grower diets with increasing protein levels, or low protein diets with 90, 100, or 110% NRC recommended levels of methionine, lysine, tryptophan, Arginine, and threonine.
Abstract: This study sought to determine specific correlations between dietary protein, amino acids, and increasing environmental temperatures for broilers. Male broilers were house in six different constant environmental temperatures ranging from 21.1 to 35°C and fed a series of 3250 kcal ME grower diets with increasing protein levels, or low protein diets with 90, 100, or 110% NRC recommended levels of methionine, lysine, tryptophan, Arginine, and threonine. The broilers house in temperatures below 25.3°C showed increased weight gains with increased CP diets, whereas birds house in temperatures greater than 26.7°C showed depressed gain with CP diets greater than 20%. Broilers fed the 16 and 18% diets did not show increased gains with the five added essential amino acids under any temperature conditions, indicating that other amino acids were limiting.
TL;DR: It is indicated that dietary protein concentrations as low as 24% are adequate for maximum weight gain of pond-raised channel catfish fed daily to satiation and dressout percentage tended to decrease linearly as dietary protein decreased.
Abstract: This study was conducted to evaluate the use of low protein diets for channel catfish Ictalurus punctatus raised in earthen ponds at high density. Fingerling channel catfish were stocked into 0.04-ha earthen ponds at a rate 24,700 fish/ha and fed experimental diets daily to satiation from April to October 1995. The five diets contained either 32, 28, 24, 20, or 16% crude protein with digestible energy to protein (DE:P) ratios ranging from 8.9 to 16.2 kcal/ g protein. Weight gain was not different among channel catfish fed diets containing 32, 28, or 24% crude protein. Fish fed diets containing 20% or 16% crude protein gained less weight than fish fed the diets containing 28% or 24% crude protein, but not statistically less than the fish fed the 32% crude protein diet. Feed consumption data followed similar trends as weight gain data. Feed conversion ratio increased linearly as dietary protein decreased, but was not significantly different (multiple range test) for fish fed diets containing either 32% or 28% crude protein. There were no differences in survival and hematocrit of fish fed the different diets. No differences (multiple range test) were observed in dressout percentages for fish fed the various diets, but dressout percentage tended to decrease linearly as dietary protein decreased. Visceral fat and fillet fat increased and fillet protein and moisture decreased linearly as dietary protein decreased. Results from this study indicated that dietary protein concentrations as low as 24% are adequate for maximum weight gain of pond-raised channel catfish fed daily to satiation. Fish fed dietary protein levels below 24% grew relatively well, particularly considering that dietary protein was reduced 40–50% below that typically used in commercial channel catfish feeds. However, dietary protein levels below 24% may increase fattiness to an unacceptable level presumably because of the high digestible energy to protein ratio.
TL;DR: This work studied the efficacy of fluconazole in the treatment of tinea capitis in children and confirmed its favorable results in various systemic mycoses, candidiasis, and dermatophyte infections.
Abstract: Fluconazole, a water soluble bis-triazole, is a highly selective inhibitor of fungal cytochrome P450 and sterol 14-alpha demethylation. It has good bioavailability, low protein binding, and a long half-life. After oral administration it rapidly distributes to the subcutaneous tissues and epidermis, where it accumulates. Favorable results have been obtained with fluconazole in the treatment of various systemic mycoses, candidiasis, and dermatophyte infections. We studied the efficacy of fluconazole in the treatment of tinea capitis in children.
TL;DR: Results indicate that the stoichiometric approach, originally developed for hybridoma cultures, is a fast and effective method for cell culture process design and improvement.
Abstract: The application of a stoichiometric medium design approach was studied in fed-batch cultivation of Chinese hamster ovary (CHO) cells. A serum-free medium containing a very low protein concentration (2 mg/L insulin) was developed. A supplemental medium was formulated according to the stoichiometric equation governing cell growth using cell composition obtained from hybridoma cells. Fed-batch culture was conducted in spinner flasks using the supplemental medium for feeding. Significant improvement in cell growth, by-product reduction, and Gamma-Interferon (IFN-gamma) production was achieved as compared to a typical batch culture. Results indicate that the stoichiometric approach, originally developed for hybridoma cultures, is a fast and effective method for cell culture process design and improvement. The glycosylation of IFN-gamma was monitored off-line during the culture process. The accumulative IFN-gamma glycosylation efficiency was slightly improved as compared to that of the batch culture, due to the nutritional control through the stoichiometric feeding. Periodic glucose starvation was observed during the fed-batch culture as a result of the manual feeding. Pulse-chase radiolabeling assay shows that glucose starvation leads to a deteriorated IFN-gamma glycosylation efficiency. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 577-582, 1997.
TL;DR: Reports of low protein C (PC) and S (PS) concentrations in steady‐state patients with homozygous sickle cell (SS) disease when compared to a racially matched normal haemoglobin (AA) control group are confirmed.
Abstract: The aim of this study was to confirm reports of low protein C (PC) and S (PS) concentrations in steady-state patients with homozygous sickle cell (SS) disease when compared to a racially matched normal haemoglobin (AA) control group and to examine the mechanisms of this reduction with respect to hepatic function, coagulation activation and haematological indices.
In 36 SS patients and 35 AA race-matched controls PC (functional and immunoreactive), PS (free and total) were measured. C4B binding protein (C4B) was assessed by immunoelectrophoresis and D-dimer by ELISA. Hepatic function was assessed by prothrombin (PT) time (49 SS, 64 AA), factor V (34 SS, 36 AA) and factor VII concentrations (28 SS, 29 AA). Proteins induced in vitamin K absence or antagonism (PIVKA) were sought in 12 SS's. The relationship between PC, PS and total bilirubin, haemoglobin (Hb) F and reticulocyte count was also assessed.
PC, PS and C4B were lower in SS disease. SS patients had longer PT times, and lower factor V and VII concentrations in comparison to AA controls. PC (functional and immunoreactive) and free PS correlated with PT. Within SS genotype PT correlated negatively with factor V and factor VII. Factor V and VII were positively correlated. PIVKAs were not detected. There was no correlation between PC, PS and D-dimer, haemolytic rate or Hb F concentration.
Prolongation of PT time, low factor V and VII suggest that hepatic dysfunction, rather than coagulation activation or haemolytic rate, accounts for the reduced concentrations of PC and PS in steady-state SS disease. The absence of PIVKAs suggests a hepatocellular problem.
TL;DR: In this article, a large white XLandrace pigs were assigned at 13 kg to one of six dietary crude protein (P) treatments (230 g/kg (P1), 201 g/ kg (P2), 178 g/kg (P3), 151 g/g/kG (P4), 125 g/mk (P5), 93 g/nk (p6), and one of four temperatures (T) (no. = 4) (18°C, 22°C), and were given food ad libitum until slaughter
Abstract: Ninety-six entire male Large White XLandrace pigs were assigned at 13 kg to one of six dietary crude protein (P) treatments (230 g/kg (P1), 201 g/kg (P2), 178 g/kg (P3), 151 g/kg (P4), 125 g/kg (P5), 93 g/kg (P6)) and one of four temperatures (T) (no. = 4) (18°C, 22°C, 26°C, 30°C), and were given food ad libitum until slaughter weight of 30 kg. At all temperatures gut fill was a constant proportion of food intake (Fl) (1·56) but this ratio varied with different protein concentrations. Food intake increased with decreasing temperature and with decreasing protein content to a maximum rate on P4 (1·347 kg) whereafter FI declined. There was a linear decrease in average daily gain (ADG) with decreasing protein content while temperature had a significant curvilinear effect on ADG and food conversion ratio (FCR) with maximum ADG (0·680 kg/day) at 26°C. Body protein content decreased as the dietary protein concentration declined below P3 and there was a corresponding increase in lipid content. Temperature had no effect on body protein content but had a significant effect on lipid content. Similar trends occurred in the rate of protein (PR) and lipid (LR) retention with maximum PR (117·1 g/day) attained on PI, P2 and P3. Protein and temperature had a significant effect on total heat loss (THL). Maximum THL occurred in the protein treatment that resulted in pigs consuming maximum FI. The efficiency of protein utilization increased with increasing temperature but the response was dependent on the protein supply. It is concluded that on low protein diets pigs increase their Fl to maintain potential protein growth until a point is reached where the animal can no longer compensate and FI will decline. The extent of the compensation will depend on the amount of heat the animal can lose which in turn is dependent on the environmental temperature.
TL;DR: Minor strain differences exist with respect to response to juvenile nutrition, although such effects are only evident in early lay, and all strains of bird remain small, 18-wk body weight is reduced, and these birds subsequently eat less feed and produce smaller eggs.
TL;DR: It is concluded that a high-protein diet can be safely administered to critically ill patients with acute renal failure receiving continuous renal replacement therapy and improves nitrogen balance when compared to moderate protein intake.
Abstract: Critically ill patients with acute renal failure are traditionally treated with low-protein diets to help control uremia. This dietary approach may be deleterious to the patient's nutritional status and unnecessary, especially if continuous renal placement therapies (CRRT) are used. However, the optimal amount of protein supplementation during CRRT is unknown. In patients receiving CRRT, a high protein intake may result in a positive nitrogen balance in the absence of uncontrolled uremia. Accordingly, we studied nitrogen metabolism in two consecutive cohorts of acute renal failure patients receiving equal amounts of calories but variable amounts of nitrogen. One group received protein according to the preferences of the attending clinician, the other a high and fixed amount of protein (2.5 g/kg/day). Patients treated according to attending clinician preferences received significantly less dietary protein (1.2 g/kg/day vs. 2.5 g/kg/day; p < 0.0001) and had a negative mean nitrogen balance of -5.5 g/day. Patients receiving a high and fixed amount of protein had a less negative mean nitrogen balance (-1.92 g/day). Such patients were more likely to experience a positive nitrogen balance during any 24-h period (53.6% vs. 36.7%; p < 0.05). They also required more aggressive hemofiltration to maintain control of uremia (mean ultradiafiltrate volume: 2145 mL/h vs. 1658 mL/h; p < 0.0001) and had a significantly higher but still acceptable mean plasma urea level (26.6 mmol/L vs. 18 mmol/L; p < 0.0001). Survival was not significantly different in the two groups (37.5% vs. 31.3%). We conclude that a high-protein diet can be safely administered to critically ill patients with acute renal failure receiving continuous renal replacement therapy. Such a high protein intake improves nitrogen balance when compared to moderate protein intake. A low protein intake is unnecessary in patients treated with CRRT.
TL;DR: In this article, the effectiveness of conventional rheological dechniques (destructive) and the oscillatory dynamic test (non-destructive), for the study of the physical properties of concentrated yogurt (labneh) was studied.
Abstract: The effectiveness of conventional rheological dechniques (destructive) and the oscillatory dynamic test (non-destructive) for the study of the physical properties of concentrated yogurt (labneh)was studied. Six different types of labneh (control (cloth bag method), ultrafiltrated (UF) after and -before fermentation, reverse osmosis (RO) -after and -before fermentation and direct reconstitution from whole milk powder) were examined. Dynamic rheological studies revealed that labneh is a viscoelastic system in which its elastic characteristic is more dominant than its viscous properties. The elastic and viscous attributes of the control labneh were significantly different from the rest of the test samples. In general, the samples with low protein content (RO-after and -before fermentation and direct reconstitution labneh) produced weaker gel structures than their UF counterparts. The penetrometer and viscometer (destructive techniques) failed to reveal expected differences between the samples, and the results did not correlate with the oscillatory dynamic tests. In the light of these results, it could be suggested that dynamic studies are much more reliable than the destructive rheological techniques for the study of the physical properties of labneh.