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Showing papers on "Low protein published in 1985"


Journal ArticleDOI
TL;DR: A facile purification has been devised for recombinantly produced Salmonella typhimurium acetolactate synthase isozyme II by determining the complex set of factors that lead to loss of enzymic activity with this rather labile enzyme.
Abstract: A facile purification has been devised for recombinantly produced Salmonella typhimurium acetolactate synthase isozyme 11. Purification of the enzyme was made possible by determining the complex set of factors that lead to loss of enzymic activity with this rather labile enzyme. When complexed with thiamin pyrophosphate, FAD, and magnesium, acetolactate synthase is subject to oxygen-dependent in- activation, a property not shared by the enzyme-FAD complex. When divorced from all of its tightly bound cofactors, losses of the enzymic activity are encountered at low ionic strength, especially at low protein concentrations. If purified and stored as the enzyme-FAD complex, acetolactate synthase is quite stable. The enzyme is composed of two types of subunits, a result that was not anticipated from previous studies of ilvG (the gene that codes for the large subunit of acetolactate synthase). These subunits were determined to be in equal molar ratio in the purified enzyme from the distribution of radioactivity between the two subunits after carboxymethylation with iodo( 14C)acetate and their respective amino acid compositions. Besides the expected iluG gene product (59.3 kDa), purified acetolactate synthase contained a smaller subunit (9.7 kDa; designated here as the iluM gene product). On the basis of sequence homology of the small subunit with that coded for by the corresponding Escherichia coli gene sequence (Lawther, R. P., Calhoun, D. H., Adams, C. W., Hauser, C. A., Gray, J., & Hatfield, G. W. (1981) Proc. Natl. Acud. Sci. U.S.A. 78,922-9251, it is encoded by the region between iluG and ilvE, beginning at base-pair (bp) 1914 (relative to the point of transcription initiation). Amino-terminal sequence analysis of the large subunit of acetolactate synthase identifies the initial position of translation for ilvG as bp 271. The stop and start codons of ilvG and ilvM overlap. Overlapping stop and start codons have been observed for several other genes whose gene products are produced in equal amounts. Native acetolactate synthase has a molecular weight of about 140 000 and is thus composed of two large and two small subunits.

138 citations


Journal ArticleDOI
TL;DR: Dietary protein may have influenced parasite establishment since lambs on the low protein diet had a higher faecal egg output four weeks after infection and more severe clinical signs than infected lambs of the same breed on a high protein diet.

115 citations


Journal ArticleDOI
TL;DR: A plaque assay has been developed that is based on enzyme immunoassay principles and capable of screening several hundred samples in one day, and may be used to evaluate the optimal conditions required for in vitro immunizations.

93 citations


Journal ArticleDOI
TL;DR: An increase in intake was associated with increasing litter size, increasing parity and lower pregnancy weight gain, and a number of other factors to be associated with variation in intake including breed of sow, system of feeding and system of sow management.

92 citations


Journal ArticleDOI
TL;DR: In this paper, four trials were conducted with 8-day-old crossbred chicks to determine the limiting amino acids (AA) in a low-protein corn-soybean meal diet.

79 citations


Patent
09 Jan 1985
TL;DR: In this article, a method for stabilizing human gamma globulin (IgG) preparations with histidine-stabilized immunoglobulin (HGI) is described.
Abstract: Histidine-stabilized immunoglobulin preparations and a method for their manufacture are disclosed. The present invention is particularly well suited for stabilization of human gamma globulin (IgG) preparations having a relatively low protein content. Preferred stabilized human gamma globulin preparations comprise about 5 wt-% or less gamma globulin, histidine at a concentration of about 0.025M to about 0.2M, and optionally glycine at a concentration of about 0.05M to about 0.5M. The pH value of the preparations is at least 6.0 but not more than 7.0. A pH value of about 6.4 is most preferred. Conductivity of the preparations is about 2 to about 4 millisiemens at 5° C., preferably about 2.5 to about 3.5 millisiemens at 5° C., and most preferably about 2.7 millisiemens at 5° C.

73 citations


Journal ArticleDOI
TL;DR: With an increase in the amount of dietary protein, feed consumption decreased, thus the growth rate was better in the fish fed on the diet containing 30% protein than those feeding on the 40% protein diet, and its digestible energy level was sufficient for the fish.
Abstract: Feeding experiments were conducted twice, Experiments I and II, in order to determine an optimum dietary protein level for Tilapia nilotica by feeding them with casein diets containing corn oil as a lipid source.Daily feed consumption was found to be affected by dietary protein or cellulose levels. With an increase in the amount of dietary protein, feed consumption decreased, thus the growth rate was better in the fish fed on the diet containing 30% protein than those fed on the 40% protein diet.Effect of dietary cellulose levels on the feed consumption was great in the case of low protein diets. The best growth rate was obtained in the fish receiving the 30% protein diet, when its digestible energy (DE) level was sufficient for the fish. The amount of DE and nitrogen intake required for their maximum growth is estimated to be around 12-13 kcal and 160-170mg/l00g body weight/day, respectively.

71 citations


Journal ArticleDOI
TL;DR: It is concluded that a decrease in lung glutathione may be partially responsible for the increased oxygen sensitivity in the protein-deficient rats, but that other factors are necessary for explanation of the relative oxygen tolerance of the feed-restricted animals with reduced levels of glutATHione in the lung.
Abstract: Male rats weighing 200-250 g were fed a 25% casein diet in restricted amounts or ad libitum or one of two low protein diets (3 and 0% casein) ad libitum. Decreased tolerance to hyperoxic stress was observed only in the rats fed low protein diets. These animals had a median death time of 49-50 h compared to 58-69 h for feed-restricted or normal control groups. Death was due to accelerated development of lung edema. Changes in total lung levels of glutathione reductase, glucose-6-phosphate dehydrogenase or catalase did not correlate with oxygen sensitivity. Lung glutathione levels were related to the amount of sulfur-containing amino acids in the diet and were depressed in the feed-restricted as well as the protein-restricted groups. However, feed restriction alone did not enhance oxygen toxicity. We conclude that a decrease in lung glutathione may be partially responsible for the increased oxygen sensitivity in the protein-deficient rats, but that other factors are necessary for explanation of the relative oxygen tolerance of the feed-restricted animals with reduced levels of glutathione in the lung.

56 citations


Journal ArticleDOI
TL;DR: The results of the study on herpes simplex virus (HSV) ribonucleotide reductase are in favour of the existence of two subunits, H1 and H2, different from the mammalian sub units, M1 and M2.
Abstract: Summary In nearly all systems studied, ribonucleotide reductase consists of two non-identical subunits. We present here the results of our study on herpes simplex virus (HSV) ribonucleotide reductase in favour of the existence of two subunits, H1 and H2, different from the mammalian subunits, M1 and M2. First, although the viral subunits could not be separated by Blue Sepharose chromatography (unlike mammalian subunits), they seemed to dissociate at very low protein concentration as suggested by the non-linear relationship between activity and low protein concentration. Second, pyridoxal phosphate (Pyr.P)-NaBH4 treatment and 4-methyl-5-amino-1-formylisoquinoline thiosemicarbazone (MAIQ) treatment of partially purified extract of mammalian ribonucleotide reductase which inactivated M1 and M2 respectively also inhibited the HSV ribonucleotide reductase. This activity could be restored by mixing Pyr.P-NaBH4-treated extracts with MAIQ-treated extracts of viral ribonucleotide reductase, suggesting that each treated extract contains one active subunit. Moreover, the addition of exogenous M1 and M2 subunits to one or the other of these two treated extracts did not produce any detectable reductase activity. Our interpretation of these results is that the two subunits H1 and H2 which could dissociate upon treatment did not form enzymically active hybrids with the mammalian subunits. Also, the higher degree of resistance to heat inactivation and to hydroxyurea of the viral reductase as compared to the mammalian enzyme suggests that H1 differs from M1 and H2 from M2.

50 citations


Journal ArticleDOI
TL;DR: It is suggested that low protein C concentrations in DIC mean a consumption of protein C probably due to its activation by thrombin and/or impaired liver synthetic function.
Abstract: Protein C was measured by means of enzyme-linked immunosorbent assay (ELISA) in plasmas from 58 normal subjects, 39 patients with disseminated intravascular coagulation (DIC) and 5 patients with thrombotic thrombocytopenic purpura (TTP). Protein C levels ranged from 69.7 to 163.6% (95% confidence limits) in normal subjects. In patients with DIC, protein C concentrations were significantly decreased, with a geometric mean value of 42.1%. Protein C concentration was positively correlated with plasma prothrombin, antithrombin III and serum pseudocholinesterase, and was negatively correlated with von Willebrand factor antigen (vWF:Ag) and vWF:Ag/factor VIII ratio. These findings suggest that low protein C concentrations in DIC mean a consumption of protein C probably due to its activation by thrombin and/or impaired liver synthetic function. In patients with TTP, protein C levels were normal with a geometric mean value of 116.7%, indicating that the pathophysiology of TTP is quite different from that of DIC.

48 citations


Journal ArticleDOI
TL;DR: The data indicate that pulmonary surfactant remains physiologically active after removal of most of its protein components and that enrichment with DPPC and PG reduces the in vitro minimal surface tension without adding to the in vivo efficacy.
Abstract: A natural surfactant with low protein content (1%) was prepared by a sequence of cold centrifugation, heating to 90 degrees C, sucrose-gradient centrifugation, and extraction with chloroform:methanol. Some of the material was enriched with dipalmitoylphosphatidylcholine (DPPC) and unsaturated phosphatidylglycerol (PG) to relative concentrations of 56% and 10%, respectively. The in vitro physical properties of these preparations were evaluated with pulsating bubble and Wilhelmy balance and their in vivo activity with experiments on artificially ventilated premature newborn rabbits, delivered on day 27 of gestation. The animals were kept in body plethysmographs at 37 degrees C and ventilated artificially with a standardized sequence of insufflation pressures: 25, 20, and 15 cm H2O. The lungs were fixed by vascular perfusion and the alveolar expansion evaluated morphometrically in histologic sections. Enrichment of surfactant with DPPC and PG resulted in lower minimal surface tension during surface compression but did not further improve lung compliance or the alveolar expansion pattern. Treatment with nonenriched surfactant at a phospholipid concentration of 100 mg/ml (individual dose = 200 mg/kg) caused a markedly increased lung compliance at all insufflation pressure levels (p vs. controls less than .01). Our data indicate that pulmonary surfactant remains physiologically active after removal of most of its protein components and that enrichment with DPPC and PG reduces the in vitro minimal surface tension without adding to the in vivo efficacy.

Journal ArticleDOI
TL;DR: The soluble form of dopamine beta-hydroxylase from bovine adrenal medulla has previously been shown to exist as a tetrameric species of Mr = 290,000 composed of two disulfide-linked dimers, and this enzyme can also undergo a reversible tetramerdimer dissociation which is dependent on pH.

Journal Article
TL;DR: The results support the view that theophylline and theobromine are metabolized by a common group of cytochromes P-450 under similar regulatory control.
Abstract: The total plasma and partial metabolic and renal clearances of theobromine and theophylline were determined in 13 healthy volunteers. Total plasma clearance for theobromine was 46% greater than that for theophylline, but the unbound clearances were almost identical. Theobromine renal clearance was 67% greater than that for theophylline but most of the difference was due to the lower protein binding of theobromine (free fraction = 0.86 compared to 0.58 for theophylline). Clearance by N-demethylation at the 3-position was 3.7-fold higher (unbound clearance 2.5-fold higher) for theobromine than for theophylline, showing that the position of the other methyl substituent (positions 1 or 7) is a major determinant of metabolic rate. There was a high degree of correlation between theophylline and theobromine plasma clearances (r = 0.86) and also between partial metabolic clearances both within drugs and across drugs (r = 0.65-0.99). The renal clearances of theophylline and theobromine were also correlated (r = 0.71). The results support the view that theophylline and theobromine are metabolized by a common group of cytochromes P-450 under similar regulatory control. Theobromine is a good model compound for assessing the activity of these enzymes in man as it has low pharmacological activity and low protein binding, its total and partial metabolic clearances correlate closely with those of theophylline, and close to 100% of the dose can be recovered as known metabolites.

Journal ArticleDOI
TL;DR: It is suggested that the growing horse, if exercised regularly, may be given a diet of lower protein concentration than currently recommended without significant reduction in growth rate.
Abstract: Summary Rates of growth were measured in two-year-old (Experiment 1) and nine-month-old (Experiment 2) horses fed high (12 or 14 per cent) or low (6 or 8 per cent) crude protein diets with one of two levels of exercise (0 or 12 km trotting per day at 12 km/h). In the non-exercised horses feed intakes and growth rates were greater on the high than on the low protein diets. Exercise increased feed intakes and growth rates of horses on the low but not the high protein diets, so that in the exercised groups there were no significant differences in feed intakes or growth rates between the horses on the two dietary protein levels. Exercise increased the apparent digestibility of dry matter, energy and crude protein. There were no differences in skeletal characteristics caused by either dietary protein level or exercise. These results suggest that the growing horse, if exercised regularly, may be given a diet of lower protein concentration than currently recommended without significant reduction in growth rate.

Journal ArticleDOI
TL;DR: In this paper, the kinetics of the quenching of the long-lived excited states of CrL_3^(3+) and RuL_ 3^(2+) complexes by the copper proteins plastocyanin, azurin, and stellacyanin have been studied in aqueous solution.
Abstract: The kinetics of the quenching of the long-lived excited states of CrL_3^(3+) and RuL_3^(2+) complexes (L is 1,10-phenanthroline and 2,2’-bipyridine or substituted derivatives) by the copper proteins plastocyanin, azurin, and stellacyanin have been studied in aqueous solution. The rate constants for quenching by the Cu(I) proteins approach a limiting value of ~10^(6) s^(-1) at high protein concentration. The kinetic behavior for plastocyanin is discussed in terms of a model in which the metal complex binds at a remote site 10-12 A from the copper center. The model allows for electron transfer both from this remote site and by attack of the metal complex adjacent to the copper center. The results show that at low protein concentration the adjacent pathway is about 10 times faster than the remote pathway. The rate constant for the intramolecular electron transfer from the remote site is consistent with the value expected on the basis of theoretical calculations.

Journal ArticleDOI
S. S. Silva1
TL;DR: The feed cost-saving factor, by adopting alternate feeding schedules as compared to presenting a high-protein diet continuously, is shown to be significant and performed best followed by those reared on schedule 1A/3B; where the numerical value refers to the number of days a particular diet was offered continuously.
Abstract: . Oreochromis niloticus (L.) young of two size groups, 170-213 mg (±7) and1-017-1-072 g (±0-04), were reared under seven different dietary schedules for 70days. The two control diets had 18% and 30% protein content; the other fiveschedules were randomly determined, where the feeding of the low-protein dietalternated with the high-protein diet, for differing periods. On the basis of theobserved rate of growth, food conversion ratio, protein efficiency ratio andpercentage protein retained in both size groups of young O. niloticus, those rearedon a dietary schedule of 2A/3B performed best followed by those reared on schedule1A/3B; where the numerical value refers to the number of days a particular diet wasoffered continuously. The feed cost-saving factor, by adopting alternate feedingschedules as compared to presenting a high-protein diet continuously, is shown to besignificant. Introduction Most experimental work aimed at reducing the feed cost — often the highestoperational cost component of all aquacultural practices — have hitherto centredaround the substitution of the animal protein component of the diets by materials ofplant origin to varying degrees (Cruz & Laudencia 1977; Jackson, Capper & Matty1982; Viola & Arieli 1982). Recently, De Silva & Perera (1983, 1984) observed tha'tin two cichlid species, maintained on different diets and under different environ-mental conditions, the digestibility of dry matter and protein varied from day to day.depicting an apparent rhythmicity. Based on these observations De Silva (1985)hypothesized that daily presentation of a diet of high protein content could bewasteful and that presentation of high and low protein content diets alternately mightprovide a means of reducing the feed cost.In this paper results of experiments carried out on two size groups ofOreochromis niloticus young to test the above hypothesis are presented.

Journal ArticleDOI
TL;DR: Values for CIn and CPAH were markedly depressed in both groups but to a greater extent in high protein-fed rats, averaging less than 60% of values measured in low protein- fed animals.
Abstract: Whole kidney inulin (CIn) and PAH (CPAH) clearances were measured after unilateral release of bilateral ureteral obstruction (BUO) of 24-h duration in rats fed for 4 wk isocaloric diets containing either 40% casein (high protein diet) or 6% casein (low protein diet). Values for CIn and CPAH were markedly depressed in both groups but to a greater extent in high protein-fed rats, averaging less than 60% of values measured in low protein-fed animals. Captopril, an inhibitor of the angiotensin I converting enzyme, increased CIn and CPAH markedly but comparably in high or low protein fed rats. Micropuncture studies performed after unilateral release of BUO in another group of rats fed a high or a low protein diet revealed lower levels of glomerular plasma flow rate (QA) and single nephron glomerular filtration rate (SNGFR) in rats fed a high protein diet. Values for renal arteriolar resistances were nearly twofold in high as compared with low protein-fed animals. Infusion of OKY-1581, an inhibitor of thromboxa...

Journal ArticleDOI
TL;DR: The amino acid pattern for pollens from both indigenous and exotic plants indicated that, generally, the levels of amino acids in the pollens were above the bees' requirements.
Abstract: The protein and amino acid contents of bee-collected pollens from 10 indigenous and 16 exotic Australian plants were determined. Crude protein content showed a large variation with a range from 9.5% for Pinus radiata pollen, to 36.9% for Banksia ornata pollen. Pollens which were found to have high protein contents are those which are also highly favoured by apiarists whereas those with low protein content are considered to be nutritionally inferior pollens. The amino acid pattern for pollens from both indigenous and exotic plants indicated that, generally, the levels of amino acids in the pollens were above the bees' requirements. Tryptophan appeared to be the first limiting amino acid in Australian pollens for honeybees.

Journal ArticleDOI
TL;DR: The applicability of vibrational spectroscopy for determination of the partitioning preferences of membrane proteins into regions of particular chemical structure or physical order in a complex lipid environment is demonstrated.
Abstract: CaATPase from rabbit sarcoplasmic reticulum has been reconstituted into binary lipid mixtures of 1-palmitoyl-2-oleoylphosphatidylethanolamine (POPE)/1,2-dipalmitoylphosphatidylcholine-d62 (DPPC-d62) and 1-stearoyl-2-oleoylphosphatidylcholine (SOPC)/DPPC-d62. Fourier-transform infrared (FT-IR) spectroscopy has been used to monitor temperature-induced structural alterations in the individual lipid components in the presence and absence of protein. A simple two-state model is used to construct a phase diagram that is in good agreement with one constructed from differential scanning calorimetry data, for the POPE/DPPC-d62 (protein-free) system. Although these two lipids are miscible over at least most of the composition range, substantial deviations from ideal behavior are observed. An estimate of the nonideality of mixing in both the gel and liquid-crystalline phases is obtained from regular solution theory. The phase diagram for SOPC/DPPC-d62 shows gel-phase immiscibility. FT-IR studies of ternary (POPE/DPPC-d62/CaATPase) complexes indicate that both lipid components are disordered by protein at all temperatures studied. In addition, their melting events are broadened and shifted to lower temperatures compared with the appropriate binary lipid mixture. Semiquantitative estimates for the fraction of each lipid melted are obtained from the model. The effect of protein on SOPC/DPPC-d62 mixtures depends on that total lipid to protein ratio. At low protein levels, SOPC is preferentially selected by CaATPase, so that bulk lipid is enriched in DPPC-d62. At high levels of protein, both lipid components are selected. The applicability of vibrational spectroscopy for determination of the partitioning preferences of membrane proteins into regions of particular chemical structure or physical order in a complex lipid environment is demonstrated.

Journal ArticleDOI
TL;DR: The response of BCKAD in liver can contribute to the leucine-induced stimulation of valine oxidation in vivo but analysis of the results of this study leads to the conclusion that other mechanisms, probably in nonhepatic tissues, must also be involved.
Abstract: As part of an effort to explain the leucine-induced depressions of plasma isoleucine and valine concentrations, and the concomitant stimulation of valine oxidation in vivo, branched-chain a-keto acid dehydrogenase (BCKAD) activ ity was measured in livers from rats that were fed for only 6 h/d large quantities of individual amino acids in a low protein diet. Preincubation of homogenates with buffer containing Mg2' and Ca2*allowed estimation of fully active complex. Cytosolic and mitochondrial branched-chain-amino-acid aminotransferase (BCAAT)activities were also measured in livers of rats fed an excessof leucine. The percentage of BCKAD in the active form in livers of rats fed the low protein diet containing an excess of leu- cine, isoleucine, valine or phenylalanine for 2 d was double that of rats fed the low protein control diet (control, leucine, isoleucine, valine and phenylalanine groups having, respectively, 45 ±2, 85 ±7, 85 ± 3, 95 ±5, and 81 ±4% of hepatic BCKAD in the active form). Consumption of a low protein diet containing an excess of leucine had no significant effect on either cytosolic or mitochondrial BCAATactivi ties of liver. The response of BCKAD in liver can contribute to the leucine-induced stimulation of valine oxidation in vivo but analysis of the results of this study leads to the conclusion that other mechanisms, probably in nonhepatic tissues, must also be involved. J. Nutr. 115: 1550-1561, 1985. INDEXING KEYWORDS branched-chain amino acid antagonism • branched- chain a-keto acid dehydrogenase • branched-chain-amino-acid aminotransferase • amino acid toxicity

Journal ArticleDOI
TL;DR: The influence of temperature on growth, feed conversion, and protein and gross energy utilization was assessed in two experiments using the European catfish, Silurus glanis L, in trials lasting 6 and 7 weeks.
Abstract: Summary The influence of temperature on growth, feed conversion, and protein and gross energy utilization was assessed in two experiments using the European catfish, Silurus glanis L. Animals of 55 g and 24 g were used in trials lasting 6 and 7 weeks, respectively. The optimum temperature for growth was within the range of 25 to 28°C, with the best results obtained at 27°C. Using a feed of low protein content (30.3%), a feed conversion of 1.67 was achieved at a specific growth rate of 1.78% of body weight/day.

Journal ArticleDOI
TL;DR: Fertility did not differ; however, the LP birds exhibited significantly better hatch of fertile eggs and significantly decreased late deads when compared to HP birds, while the HE birds exhibitedificantly less early embryonic mortality but significantly more late embryonic mortality when compared with LE birds.

Patent
16 Oct 1985
TL;DR: Frozen pizza product with special baked pastry shell is produced from a dough comprising a specified mixture of high protein and low protein wheat flours, and containing between 10 and 17% by weight of solid fat pieces, preferably flakes, of specified dimensions, wherein the fat pieces have a melting point in the range 118°-128° F. by the Wiley method, and wherein the mixing takes place so that the solid fat piece remain as such as the dough goes into the oven for baking as mentioned in this paper.
Abstract: Frozen pizza product with special baked pastry shell is produced from a dough comprising a specified mixture of high protein and low protein wheat flours, and containing between 10 and 17% by weight of solid fat pieces, preferably flakes, of specified dimensions, wherein the fat pieces have a melting point in the range 118°-128° F. by the Wiley method, and wherein the mixing takes place so that the solid fat pieces remain as such as the dough goes into the oven for baking. After topping with pizza sauce and freezing, the resulting crust is tender in the inside and crisp on the bottom, after final rebaking by the consumer, even after freeze-thaw cycles which sometimes occur during shipping and storage.

Journal ArticleDOI
TL;DR: It is shown that the differentiation and the maturation of the myeloid blast cells modify the nuclear size, and the combination of these two parameters provides useful information for cytological classification.
Abstract: Simultaneous analysis of DNA and cellular proteins provides information on cell proliferation and metabolism. Cellular protein content coupled with nuclear geometric parameters can be used to evaluate cellular maturation and differentiation. In this study, leucoblasts from 50 cases of adult acute myeloid leukemia were analyzed by flow cytometry, and semiautomatic morphometry was performed on bone marrow smears. Ethanol-fixed bone marrow blast cells were stained for DNA with propidium iodide (PI) and for proteins with fluorescein isothiocyanate (FITC). On the resulting FITC versus PI histograms we defined the cells with low protein content which are associated with a nonproliferating subpopulation (LPC fraction). Low protein content fraction and S-phase are correlated (p less than 0.01). The LPC fraction values are more dispersed than S-phase values and thus should indicate more clearly eventual differences between cellular populations. This hypothesis has been tested with the prognostic significance of cell-cycle variables: The LPC fraction was significantly higher in the complete remission group than in the other (p less than 0.01), while S-phase did not show any difference. The peak value of the protein content histograms is significantly lower in the granulocytic leukemias (M1, M2, M3) than in the leukemias with a monoblastic component (M4, M5). Furthermore, we showed that the differentiation and the maturation of the myeloid blast cells modify the nuclear size. The combination of these two parameters provides useful information for cytological classification.

Journal ArticleDOI
TL;DR: It is speculated that premature infants fed banked drip breast milk or a preterm formula have an abnormally low protein concentration in their lean body mass.

Journal ArticleDOI
TL;DR: The diffusion coefficient D of bovine serum albumin through various solutions (pH 7.0, 0.5M NaCl, Mw ∼ 1 × 105, 3 × 105) of polythylene oxide was studied with quasielastic light scattering to show that with either polymer, D falls with increasing protein concentration.
Abstract: The diffusion coefficient D of bovine serum albumin through various solutions (pH 7.0, 0.5M NaCl) of polyethylene oxide (M, - 1 x lo5, 3 x lo5) was studied with quasielastic light scattering. In solutions of the 1 x lo5 polymer solution at polymer concentrations above 0.5 g/L, D is considerably greater than would have been expected from the viscosity of water:polymer mixtures, the deviations being larger at low protein concentration than at high protein concentration. With either polymer, D falls with increasing protein concentration.

Journal ArticleDOI
TL;DR: Channel catfish that received diets containing protein mixes were significantly higher than those of fish fed the basal diet except for fish fed soy-liquid fish, and feed conversions of fish feeding soy-mix and soy- mix plus catfish meal were significantly improved.
Abstract: Five isonitrogenous and isocaloric diets containing extrusion-cooked protein mixes were fed to fingerling channel catfish in aquaria for 9 weeks. Soy-mix, soy-liquid fish, soy-catfish scrap and soy-mix plus catfish meal replaced soybean meal and fish meal in the basal diet. Weight gains of channel catfish that received diets containing protein mixes were significantly higher than those of fish fed the basal diet except for fish fed soy-liquid fish. Feed conversions of fish fed soy-mix and soy-mix plus catfish meal were significantly improved compared to those of fish fed the basal diet. Protein and fat gains were generally higher in fish fed the extruded mixes as compared to those of fish fed the basal diet. Whole body proximate composition (dry weight basis) indicated that fish fed the extrusion-cooked protein mixes contained less moisture and protein, and more fat than fish fed the basal diet. Protein efficiency ratios (determined utilizing low protein diets) indicated that fish fed the extrusi...

Journal ArticleDOI
TL;DR: It is suggested that LP diet has a protective effect both on the development and extent of tubulointerstitial nephritis that is perhaps, in part, related to the selective abrogation of effector T cell immunity.
Abstract: The protective effect of dietary protein restriction on the development and expression of immune-mediated interstitial nephritis was evaluated in Brown Norway rats with anti-tubular basement membrane disease. In the first series of experiments, pair-fed rats received low protein (LP) (3% casein) or normal protein (NP) (27% casein), normocaloric diets. After 6 wk, each group was immunized with renal tubular antigen in adjuvant to produce anti-tubular basement membrane antibody (alpha TBM-Ab) and tubulointerstitial nephritis. The kidneys harvested from NP rats after four more weeks on the diet had histologically more severe interstitial disease than the LP rats (histologic severity; NP = 3.1 +/- 0.2 vs. LP = 1.1 +/- 0.3; P less than 0.001), and serum creatinine values were concordantly different (NP = 1.34 +/- 0.02 vs. LP = 0.82 +/- 0.03). Titers of alpha TBM-Ab were similar in both groups, while the T cell-mediated immune response, as measured by delayed-type hypersensitivity (DTH), was nonspecifically impaired in LP rats when compared with the NP group. Admixture cotransfers of LP plus NP cells failed to demonstrate active suppression as an explanation for the depressed DTH in LP rats. The therapeutic role of dietary protein restriction was also examined in rats with established alpha TBM disease. In these experiments, rats were first immunized and fed NP diets for 4 wk (histologic severity = 3.0 +/- 0.2; creatinine = 1.78 +/- 0.02), and then were divided into two groups and followed for six more weeks on either LP or NP diets. LP rats, under these conditions, developed less disease than those fed NP diet (histologic severity; NP = 3.2 +/- 0.3 vs. LP = 1.4 +/- 0.2; P less than 0.001), and serum creatinine values were concordantly different (NP = 1.92 +/- 0.05 vs. LP = 0.97 +/- 0.02). Again, the titers of alpha TBM-Ab in both LP and NP groups were similar. These data collectively suggest that LP diet has a protective effect both on the development and extent of tubulointerstitial nephritis that is perhaps, in part, related to the selective abrogation of effector T cell immunity.

Journal Article
TL;DR: A low level of dissolved oxygen in the culture was found to increase the amount of antibody produced as compared with cells propagated at 60% air saturation (the optimal level for cell propagation) since the cells were kept alive for longer periods at the lower dissolved oxygen concentration.
Abstract: Factors that affected the production of monoclonal antibodies by a mouse-mouse hybridoma cell line, propagated in vitro in stirred vessels, were investigated The purpose of the research was to estimate the efficiency of this system for large scale production of monoclonal antibodies The antibody produced by these hybridoma cells was an IgG2a, specific for a surface antigen on Rhizobium japonicum NR-7 cells Antibody content in the culture supernatant was determined by a radial-immunodiffusion assay using rabbit anti-mouse IgG antibodies in the immobile phase and mouse IgG (the monoclonal antibody) as the antigen in the mobile phase This method was found to be more reproducible and reliable compared with an ELISA method Cells were adapted to grow in an inexpensive, low protein content medium based on Dulbecco's Modified Eagle Medium (DMEM) supplemented with 025% Primatone RL, 001% Pluronic polyol F-68 and fetal bovine serum as low as 1% Doubling time for the cells averaged 24 hrs, and final yields reached 2 X 10(6) cells per ml The hybridoma cells were grown in the newly developed medium in 3 liter fermentors Monoclonal antibody was produced during the early growth phase (3 days), however, most of the antibody was produced during a later growth phase (3-10 days) when 30 to 90% of the cells were dead Final antibody yields were estimated to be 100-200 micrograms/ml A low level of dissolved oxygen (25% air saturation) in the culture was found to increase the amount of antibody produced as compared with cells propagated at 60% air saturation (the optimal level for cell propagation) since the cells were kept alive for longer periods at the lower dissolved oxygen concentration Using a fed-batch propagation method we were able to keep cells alive for long periods (up to 1 month) at a concentration of about 1 X 10(6) cells per ml, and thus to increase further monoclonal antibody production Yields of 300-400 micrograms/ml were obtained

Journal ArticleDOI
TL;DR: The results suggest that the low protein levels are due to the slower maturation of M(3)w, and not to less efficient translation machinery.
Abstract: Minutes have been considered for some time to be mutant at the sites of synthesis of some components of the protein synthetic apparatus. To study the hypothetical relationship between Minutes and suboptimal translation, a group of abundant proteins, the yolk polypeptides, was assayed in outcrossed females bearing M(3)w, M(3)h y , or M(1)n mutations. Recently emerged Minute females contained a lower amount of yolk polypeptides, in both ovarian and nonovarian tissues, than their non-Minute sisters. This low level correlated with the lower abundance of cytoplasmic RNA in Minutes compared to control females. By 1 week of age, both M(3)w and their non-Minute sibs contained the same amount of yolk polypeptides and the corresponding mRNA. The double heterozygote, ap 4/+;M(3)w/+, did not differ in yolk polypeptide content from control flies. M(3)w females demonstrated reduced fecundity during the period of low yolk polypeptide content but gradually increased egg deposition as yolk polypeptide levels rose. These results suggest that the low protein levels are due to the slower maturation of M(3)w, and not to less efficient translation machinery.