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Bilateral intercollicular lesions in the chick abolish or depress not only calling, but also those phases of behaviour when calling would have been occurring. These include: long bouts of excited feeding immediately after food is made available; examining and pecking moving targets and novel objects; persistent scanning, and inhibition of other behaviour in a novel environment. Deaf birds behave precisely like controls, so that possible auditory deficits are not involved. During calling phases significant visual stimuli are treated as if they were starting or conspicuous. Conversely, continuous examination of a stimulus causes calling to diminish or disappear even though response continues; a brief period when the stimulus is not seen causes calling to begin again when it is once more perceived. In addition to the increased effectiveness of relevant visual stimuli, motor facilitation is usual in calling phases, as is inhibition of irrelevant responses. Emotional behaviour in man and other mammals is compared to calling phases in the chick.

The vasomotor response of the tail of the albino rat to total-body heating and cooling was studied by skin-temperature recording and plethysmography with the tail at 25 degrees C air temperature. Tail vasodilation started at core temperatures lightly above 37 degrees C and increased to a core temperature up to about 39 degrees C. During cooling of warm rats, tail vasoconstriction started at significantly higher levels of core temperature than the values at which vasodilation appeared when the rat was warmed.

Glucagon in a dose of 50 mug/kg body weight was studied for its cardiovascular effects in hypovolemic dogs in which coronary blood flow was reduced to an average 40% of its control value and cardiac depression was evident. Myocardial contractility, as judged mainly by dP/dt and acceleration of aortic blood flow, was brought to a normal level for a short time. Systemic and coronary vascular resistances were markedly reduced. These effects were similar in normovolemic dogs. The inotropic, chronotropic, and peripheral vascular effects of glucagon can be evoked also in hypovolemic dogs in which coronary blood flow is less than normal and myocardial metabolism is impaired.

The effect of highly purified gastric inhibitory polypeptide (GIP) on immunoreactive insulin (IRI) secretion in the conscious fasted dog was investigated. Significant increases in IRI release were observed with intravenous administration of three different doses of GIP. These were accompanied by depression in fasting serum-glucose levels. Preliminary studies were undertaken to determine whether this insulinotropic action of GIP could be attributed to a particular segment of the GIP molecule. GIP fragments produced by cleavage with cyanogen bromide and trypsin showed no significant stimulation of IRI release. The possibility that GIP might itself enhance glucose uptake or potentiate insulin-induced glucose uptake was studied with the rat hemidiaphragm preparation. No such effect was observed. In the light of this and other recent work, it is concluded that GIP is a strong candidate for an active principle in the enteroinsular axis.

Our objective was to produce reductions in the luminal volume of Henle's loop and increases in linear flow velocity through the loop. We did this in a recollection micropuncture study by collecting fluid with and without suction from early distal tubules. With suction, transit time of fast green dye through the loop decreased by 34%, calculated loop volume decreased by 28%, and fractional water reabsorption fell from 73.6 to 70.3% (p smaller than 0.025) in water diuretic rats. Absolute water reabsorption did not decrease significantly. In urea-saline dieuretic rats transit time decreased 25%, calculated loop volume decreased 22%, fractional reabsorption fell from 59.0 to 51.7% (smaller than 0.001), and absolute reabsorption decreased by 2.3 nl/min (p smaller than 0.025). Single nephron glomerular filtration rate, distal tubular sodium concentration, and osmolality were unaffected. The less pronounced effect of collection with suction in water diuretic rats may be related to the lower medullary fluid osmolality, which was 338 plus or minus 9 (S.E.) mOsmol/kg as compared to 497 plus or minus 35 in urea saline diuretic rats. Collecting fluid with suction from late proximal tubules did not alter glomerular filtration rate or fractional water reabsorption. Stumpe et al. ((1970) J. Clin. Invest. 49, 1200-1212) noted an inverse correlation between fluid reabsorption from Henle's loop and flow velocity in rats with hypertension or congestive heart failure. One can reproduce this correlation by artificially altering the transmural pressure gradient in the loop.

Prostaglandin E1 (PGE1) hyperpolarized the smooth muscle cells of guinea-pig ureter in normal Krebs solution and was without effect on ureters depolarized in KCl Krebs, PGE1 inhibited both electrically induced contractions and K+-induced contractures of the ureters. Conditions that favored greater tension development by the ureters, namely, high [K+] or high [Ca-2+] reduced the inhibitory effects of PGE1 on the K+-induced contractures. Depolarization of guinea-pig ureter with KCl Krebs led to an increase in radio-calcium content of the tissue over a 30 min loading period. This increase in the tissue's radio-calcium content was further increased by PGE1 but not by theophylline, PGE1 was found to have no effect on either total calcium content or the calcium efflux from the tissue. It is suggested that PGE1 exerts its inhibitory action by increasing calcium sequestration at the inner surface of the cell membrane.

The variable effect of excessive vitamin A intake on alimentary cholesterolemia was investigated in cockerels of strains of White Leghorns and New Hampshires. With the New Hampshire cockerels, the feeding of 0.5% of dietary cholesterol resulted in greater cholesterolemia when the diet contained 1700 I.U. of vitamin A per kilogram than when it contained 22000 I.U. of vitamin A per kilogram. With the White Leghorn cockerels, on the other hand, cholesterolemia was enhanced with the higher level of dietary vitamin A. Absorption of a single oral dose of cholesterol was increased in birds of both breeds when vitamin A had been given previously by injection. In the White Leghorn cockerels the percentage of newly absorbed cholesterol in the hepatic pool was reduced by vitamin A administration, whereas in the New Hampshire cockerels the percentage was increased. It was concluded that excess vitamin A may have divergent effects on alimentary cholesterolemia in chickens of different genetic backgrounds as a result of opposite effects on the liver-blood ratio of a large load of cholesterol.

Benzocaine, which occurs in the uncharged form in the physiological range of pH, caused inhibition of 45-Ca efflux in branacle muscle fibers. By contrast, in the presence of a low external Ca-2+ concentration it produced stimulation of the efflux. Both the inhibitory and stimulatory actions of benzocaine appeared to be less potent than those of procaine. Hemicholinium-3 (HC-3), on the other hand, which exists only in the charged form, caused a large stimulation of the 45-Ca efflux following microinjection, and the potency of this action was found to be at least 10 times greater than that of procaine. External application of HC-3 produced inhibition occasionally. Effects of tetracaine were similar to those produced by procaine; however, its inhibitory action was greater in more alkaline solution, which is the opposite of that observed with procaine. Lidocaine produced a less consistent effect than procaine; the inhibitory action of the former was less potent but the stimulatory action of the two anesthetics were comparable, p-Aminobenzoic acid was without effect on 45-Ca efflux. These results indicate that both the charged and uncharged forms of local anesthetics are capable of causing stimulatory and inhibitory effects on 45-Ca efflux in barnacle muscle fibers, and that the inhibition produced is the result of action on the CA-Ca exchange system whereas the stimulation is the result of release of Ca from internal storage sites.

The metabolic, thermal, and cardiovascular responses of two male Caucasians to 1 2 h exposure to ambient temperature ranging between 28 degrees C and 5 degrees C were studied and related to the respective ambient temperatures. The metabolic heat production increased linearly with decreasing ambient temperature, where heat production (kcal times m- minus 2 times h- minus 1) = minus 2.79 Ta degrees C + 103.4, r = -0.97, P smaller than 0.001. During all exposures below 28 degrees C, the rate of decrease in mean skin temperature (Tsk) was found to be an exponential function dependent upon the ambient temperature (Ta) and the time of exposure. Reestablishment of Tsk steady state occurred at 90-120 min of exposure, and the time needed to attain steady state was linearly related to decreasing Ta. The net result was that a constant ratio of 1.5 of the external thermal gradient to the internal thermal gradient was obtained, and at all experimental temperatures, the whole body heat transfer coefficient remained constant. Cardiac output was inversely related to decreasing Ta, where cardiac output (Q) = minus 0.25 Ta degrees C + 14.0, r = minus 0.92, P smaller than 0.01. However, the primary reason for the increased Q, the stroke output, was also described as a third-order polynomial, although the increasing stroke volume throughout the Ta range (28-5 degrees C) was linearly related to decreasing ambients. The non-linear response of this parameter which occurred at 20 degrees C larger than or equal to Ta larger than or equal to 10 degrees C suggested that the organism's cardiac output response was an integration of the depressed heart rate response and the increasing stroke output at these temperatures.

Adult male rats were fed a liquid diet providing 35% of the calories as ethanol, while pair-fed controls received the corresponding diet with alcohol replaced by an equicaloric concentration of sucrose. After 1 month, lactate/pyruvate (L/P) and beta-hydroxybutyrate/acetoacetate (beta-HB/AcAc) ratios in the livers were determined under five different conditions: (1) both diets present up to the time of sacrifice, (2) ethanol diet replaced by control diet for 24 h before sacrifice, (3) ethanol diet replaced by control diet for 48 h before sacrifice, (4) as in the preceding, followed by intraperitoneal (i.p.) injection of ethanol, 1 g/kg, 1 h before sacrifice, (5) as in the preceding, but i.p. injection 3 h before sacrifice. The L/P ratio was significantly higher in the alcohol group than in controls under the first experimental condition, but the groups did not differ under the other four conditions. The beta-HB/AcAc ratio was also significantly higher in the alcohol group under the first condition. This difference disappeared in the second and third conditions. Under the fourth and fifth conditions the beta-HB/AcAc ratio was significantly higher in the controls. The results are compatible with an adaptive increase in mitochondrial reoxidation of NADH in the chronic alcohol groups, but the possibility of a change due to alcohol withdrawal can not be excluded.

Sprague-Dawley rats were kept at 28 degrees C from 21 to 517 days age and fed one of the two following diets: a semi-purified diet containing 502 p.p.m. of Mg (control) or the same diet containing only 120 p.p.m. (mg/kg) (low-Mg). The chronic suboptimal intake of Mg by rats fed the low-Mg diet did not result in overt signs of Mg deficiency even when Mg levels were greatly reduced in carcass, plasma, and tibia, but it significantly decreased bone strength. It is suggested that Mg deficiency in man could be a factor in the weakening of bone, commonly observed in old age, even when there are no visible signs of Mg deficiency. Studies of the human situation would be of interest.

Isolated intact frog muscles were incubated in 32-P-labelled Ringer's solution for various periods of time (30 s-20 h). Labelled compounds were isolated from TCA, methanol-chloroform-water, and water extracts of muscle. Hexosephosphates, phosphocreatine, phosphoenolphyruvate, alpha-glycerol phosphate, adenosine triphosphate, and inorganic phosphate were identified after 30 s, and 4 h incubation. Much more labelling was found after 20 h. The incorporation of 32-P in 30 s into organic phosphate compounds, such as alpha-glycerol phosphate and ATP, showed that immediate esterification of Pi occured on, or just inside, the sarcolemma.

The possibility of a cholinergic involvement in the hyperthermic action produced by the injection of prostaglandin E1 (PGE1) into the anterior hypothalamic/preoptic region of the rat brain was examined. Intracerebral injection of either atropine or mecamylamine prior to the injection of PGE1 failed to attenuate the PGE1-induced hyperthermia. Both atropine and mecamylamine by themselves produced a rise in colonic temperature. It thus seems unlikely that PGE1 evokes hyperthermia in the rat by releasing endogenous acetylcholine at muscarinic or nicotinic synapses in the rostral hypothalamus. The possibility that PGE1 acts by inhibiting the release of acetylcholine within this region requires additional investigation.

Twenty-eight females with recurrent urinary tract infection were treated to eradicate their existing infections and then observed for recurrences while receiving one of the three following prophylactic regimens for 6 to 12 months: nitrofurantoin, 50 mg daily; one half tablet of trimethoprim-sulfamethoxazole (TMP-SMX) twice weekly; or one tablet of TMP-SMX once weekly. Preadolescent girls received half the adult doses. After completion of the course of prophylactic agent the patients were followed up at bimonthly intervals until infection recurred. After eradication of this new infection they were started on another prophylactic regimen. Six infections (1.0/patient-year) recurred in patients on nitrofurantoin, four infections (0.4/patients-year) reucrred in those receiving twice weekly TMP-SMX, and 12 infections (1.3/patient-year) in those receiving once weekly TMP-SMX. The mean interval between discontinuation of prophylaxis and recurrence of infection was 2.6 months. TMP-SMX in the doses used eliminated aerobic gram-negative rods from swabs from the anal canal in many patients. Gram-negative organisms resistant to trimethoprim did not cause infection either during or after therapy.

The fate of trimethoprim and sulfamethoxazole and the combination of both these agents was studied in a group of healthy pregnant women who were undergoing therapeutic abortion. Assays were performed on samples of blood, urine, amniotic fluid and fetal tissues, using a standardized protocol for the selection of patients, dose administration, sample collection and assay techniques. A comparative evaluation of kinetics to assess the maternal handling and the distribution of trimethoprim throughout the fetoplacental unit disclosed no significant difference in the concentration within fetal fluids and tissue compartments. On the other hand, the concentration of sulfamethoxazole was lower in fetal tissues than in fetal fluids when relative ratios to trimethoprim were compared. The implications of the difference in behaviour of pharmacokinetic and clinical points of view.

Trimethoprim-sulfamethoxazole (TMP-SMX) caused no significant changes in the blood glucose or insulin concentrations of diabetic subjects treated by dietary measures alone or by insulin and diet. In only one of eight subjects receiving oral hypoglycemic agents for the control of diabetes did a significant immediate increase in immunoreactive insulin follow administration of TMP-SMX. In the same patient hypoglycemic symptoms were present after the agent had been taken for 14 days.

The combination trimethoprim-sulfamethoxazole was given in high dosage (four tablets twice daily) for either 2 or 5 days to 20 patients with sinusitis diagnosed on clinical grounds. In 11 the infection was improved or cured. Swabs cultured from 18 patients of the series produced no growth in 8. The organisms most likely to be isolated are Hemophilus influenzae and Diplococcus pneumoniae.

Authenic tracheobronchial secretions/exudates (TBSE) were aspirated under direct vision via a sterile catheter passed through a fiberoptic bronchoscope from patients with chronic obstructive pulmonary disease complicated by chronic bronchitis. TBSE, saliva and blood were obtained during long-term administration of trimethoprim-sulfamethoxazole (TMP-SMX) and were assayed for drug content. Before and during treatment TBSE were cultured qualitatively and quantitatively for aerobic and anaerobic bacteria, fungi, mycoplasmas and viruses. Treatment with TMP-SMX was associated with a decrease in the recovery of Hemophilus influenzae, H. parainfluenzae, Klebsiella pneumoniae, Escherichia coli and Proteus mirabilis; however, little effect was observed on the typically nonpathogenic aerobic and anaerobic bacteria of the upper respiratory tract. TMP was found in saliva at concentrations greater than in serum. Both TMP and SMX entered TBSE in absolute and relative concentrations sufficient to take advantage of the potential for synergy against susceptible microorganisms. Patient tolerance of TMP-SMX was generally good and several patients reported a decrease in production of sputum during treatment.

Ethyl 2-amino-2-deoxy-1-thio-alpha- and -beta-D-arabinopyranoside (2 and 4) were obtained by direct ethanethiolation of 2-amino-2-deoxy-D-arabinose (1), and their structures were determined by mass and p.m.r. spectrometry. Ethyl 2-amino-2-deoxy-1-thio-alpha- and -beta-D-arabinofuranoside (11 and 13) were prepared by partial demercaptalation of 2-amino-2-deoxy-D-arabinose diethyl dithioacetal (6) with mercuric chloride (or, preferably, with bromine), with or without protection of the 5-hydroxyl group. Demercaptalation with mercuric chloride gave the beta-D anomers almost exclusively, and treatment with bromine gave a mixture of the alpha and beta anomer in the ratio of similar to 1:1. Alternatively, direct ethanethiolation of 1 in trifluoracetic acid yielded the alpha-D anomer. The structures of 11 and 13 were determined by mass spectrometry, by direct comparison of their N-acetyl derivatives with an authentic enantiomorph (15b), and by p.m.r. spectroscopy. The physicochemical properties of the four 1-thioglycosides (2,4,11, and 13) were compared with those of the O-GLYCOSIDES of D-arabinose.

Three-dimensional X-ray diffraction data were used to determine the crystal structure of alpha-D-glucuronate CaBr times 3H20, a model system for investigating the factors involved in the binding of calcium ions to D-glucuronate residues of oligo-and poly-saccharides. Crystals of the salt are monoclinic, space group P21, having a = 6.410 (1), b = 10.784 (2), c = 8.879 (1) A, betta = 92.07 (1)degrees, and Z = 2. Instensity data for 1082 reflections were measured with an automated diffractometer. A trial structure, obtained by the heavy-atom method, was refined by least squares to R = 0.025. The absolute configuration was confirmed by anomalous-dispersion effects. An outstanding feature of the crystal packing is the interaction of D-glucuronate anions with calcium ions. The calcium ion is coordinated to three symmetry-related D-glucuronate anions and to two water molecules. The D-glucuronate anion binds calcium cations through three chelation sites: one that involves a carboxyl-oxygen atom combined with O-5; one that includes the second carboxyl-oxygen atom acting in concert with O-4, and one composed of the O-1-O-2 pair of hydroxyl groups.

The state of adsorbed water in a dextran gel has been investigated by near-infrared gravimetric-adsoprtion techniques. Water-vapor adsorption (desorption) isotherms at three temperatures are reported. The calculated sorption heats are found to be markedly temperature-dependent as well as dependent on the coverage. The near-infrared spectrum (4650-9000 cm-minus 1) is reported, together with tentative assignments. The H2O combination (v+delta) band at 5184 cm-minus 1 has been examined as a function of relative humidity. The line-shapes of this band have been analyzed by a recently established, Fourier-inversion technique, and information on the microdynamics of the absorbed water molecules has been resolved on the picosecond time-scale. At low and intermediate degrees of hydration, reorientational jumps take place with periods from four to six times longer than those for free water. The onset of saturation is then accompanied by the sudden removal of the reorientational jumps. A comparison of microdynamical and thermodynamic data indicates the hydration mechanism to be highly cooperative at all relative humidities.

Graded hydrolysis of purified bael gum afforded three neutral and two acidic oligosaccharides, together with monosaccharides. These sugars were identified through periodate oxidation, methylation, reduction with lithium aluminum hydride, co-chromatography, and preparation of crystalline derivatives. The neutral oligosaccharides were characterized as 3-0-beta-D-galactopyranosyl-L-arabinose, 5-0-beta-D-galactopyranosyl-L-arabinose, and 3-0-beta-D-galactopyranosyl-D-galactose, and the acidic oligosaccharides as 3-0-(beta-D-galactopyranosyluronic acid)-D-galactose and 3-0-(beta-D-galactopyranosyluronic acid)-3-0-beta-D-galactopyranosyl-D-galactose.

The mercapto groups of cellulose xanthate can reversibly form disulphide bridges with L-cysteine. This property has been utilised for the immobilisation of a protein and an enzyme. These macromolecules, as polythiol derivatives, formed disulphide linkages with the matrix without serious disturbance of their active sites, became firmly bound to the xanthate, and were not eluted by normal washing conditions. Cellulose xanthate is a cheap, easily prepared matrix which permits a simple coupling reaction. The immobilisation process is selectively reversible.

Klebsiella Type 47 capsular polysaccharide has side chains attached to the main chain via D-glucuronic acid residues. The side chains have been removed to yield an essentially linear polysaccharide by the following sequence of reactions: (1) substitution of hydroxyl and carboxyl groups with methyl vinyl ether; (2) beta-elimination by treatment with base; (3) removal of modified uronic acid residues and protecting groups by mild acid hydrolysis. The possibility of modifying other uronic acid-containing polysaccharides by this method is discussed.

A number of O-acetylated N-acylneuraminic acids, isolated from submandibular glands of cow and horse and from horse erythrocytes, have been characterized by mass spectrometry. On the basis of the typical fragmentation patterns of the pertrimethylsilyl derivatives of the methyl esters of the compounds, they were identified as 4-O-acetyl-, 9-O-acetyl-, 4,9-di-O-acetyl-, and 7,9-di-O-acetyl N-acetylneuraminic acid, and 4-O-acetyl-and 9-O-acetyl-N-glycolylneuraminic acid.

Complexation of D-arabinose, D-fructose, D-glucitol, D-glucose, D-mannitol, L-sorbose, D-xylose, sucrose, and amylose with LiOH, NaOH, KOH, Ba(OH)2, Ca(OH)2, and Sr(OH)2 has been studied conductometrically. D-Glucitol and D-mannitol do not bind with any of the bases used. Molecular complexes (1:1) of the other carbohydrates are formed in solution. Reducing sugars bind more strongly than nonreducing ones. Stability constants for the complexes have been determined; the free-energy change is of the order of hydrogen bonding. The association process has been observed to depend significantly on the polarity of the medium.

We report here the effect of Dolichos lectin on chick embryo fibroblasts from embryos between 6th and 16th day of development. There is evidence that Dolichos lectin decreases cell number and proportion of cells incorporating tritium labelled thymidine in case of chick embryo fibroblasts of 6th, 8th and 10th day of development. Dolichos lectin stimulated the proliferation of 16-day old embryo cells. No effect was noticed on 12-day embryo cells at different concentrations of Dolichos lectin used. This lectin is specifically inhibited by N-acetyl-D-galactosamine and anti-Dolichos lectin serum. The difference in response by cells during different stages of embryonic development could perhaps be explained as some regulatory changes occurring on the cell surface.

This study extends previous work on the nuclear envelope and associated structures. It illustrates that the cylindrical structures of the honeycomb lattice are not attached to the nuclear envelope, although generally perpendicular and closely apposed to it, and that there is a complex arrangement of fibrillar material between the cylinders of the lattice. The relationship of nuclear helices to these structures is described and the possible mode of their transfer from nucleus to cytoplasm is discussed.

The hemoglobins of the chicken embryo at several stages of development have been isolated in pure form by column chromatography and their relative amounts and globin compositions determined. The analyses on separated primitive and definitive erythrocytes show that the first contain four hemoglobins different from the adult ones. The two major ones at four days, decrease gradually and are no longer detectable from 15 days on. The two minor ones increase up to 6-7 days, then decrease but are still present at hatching. The definitive embryonic erythrocytes contain two hemoglobins identical to the adult ones but their ratios change gradually during development and approach that of the adult hemoglobins at hatching.

Because of uncertainty as to the molecular weight of transferrin, a previous comparison [Von der Heul et al., Clin. Chim. Acta 38, 347 (1972)] between transferrin content of serum and total iron-binding capacity cannot be definitive. We found a conversion factor for expressing the maximum amount of iron bound by 1 mg of transferrin. We compared the resulting calculated value with values obtained by three other methods for measuring total iron-binding capacity. We agree with the previous observation that the latter, as measured radioisotopically, give higher results than would be judged from the transferrin content but the same as those for two chemical methods. The diffusion rate of transferrin in agar was the same irrespective of the degree of iron saturation. Serum transferrin concentrations were low in patients with anemia resulting from malignancy, chronic disorders, and cirrhosis of the liver, and high or normal in patients with iron deficiency anemia and in pregnant women or women who were taking birth-control pills. Measurement of transferrin concentration can be used to distinguish iron deficiency anemia from anemia resulting from chronic disorders, but offers no advantages over existing methods for estimating total iron-binding capacity.

Alkaline phosphatase isoenzymes in sera were resolved by electrophoresis on cellulose acetate membranes into seven different bands (L1, B, Pl, L2, l1, l2, and Pa, in decreasing order of electrophoretic mobility). The slowest moving band (Pa) was observed in the sera of 16 patients--15 with cancer of the pancreas and one with hemochromatosis. Sera of 50 other patients with malignant or benign diseases did not show the Pa band. The Pa band is more heat labile than is the liver isoenzyme (L1). Its behavior toward inhibitors (L-phenylalanine and L-homoarginine) is similar to that of L1. Sera containing the Pa band exhibit a diffuse band in the region where isoenzymes of intestinal origin migrate; however, its heat stability and sterospecific inhibition are different from those of intestinal isoenzymes in sera that show no Pa band.

We compare and discuss three electrophoretic methods for identifying hemoglobins S, A, C, F, and D or G. Electrophoresis on citrate agar gel was more sensitive than electrophoresis on cellulose acetate for detecting hemoglobins S and F, a fundamental consideration in designing cord-blood screening programs for detecting hemoglobin S carriers. Electrophoresis on starch gel is evidently an acceptable method for subtyping hemoglobins AA, CC, AS, SS, AC, and SC, and is more sensitive than cellulose acetate for identifying hemoglobin A1A2. Costs for the citrate agar gel, cellulose acetate, and starch gel procedures are presented.

The determination of frequency value (percentile limits) and the classification of the different variation factors allow us to define more and more homogeneous subpopulations as we use these factors for sorting. Using as our study population those persons coming to the Centre for Preventive Medicine, we were able to: (a) Describe and measure the significance and importance of physiological variations or of variations attributed to age--the latter largely related only to excessive weight, which it seems to us is often the case. (b) Establish a classification for variation factors; the recapitulatory table should be useful to clinical chemists in helping physicians interpret a laboratory test result that falls within the zone of incertitude. (c) Suggest a preliminary group of reference values for healthy subjects, to be used in interpreting a laboratory test in this way.

We describe a spectrophotometric kinetic assay for detecting creatine kinase MB isoenzyme activity in the 1 to 10 U/liter range. The MB isoenzyme was isolated [Clin. Chem. 20, 36 (1974)] and assayed (Rosalki method) with an Abbott ABA-100. Good reproducibility was demonstrated for MB isoenzyme activities near 1 U/liter (CV = 2.6%). Sera with normal or slightly increased total creatine kinase activity were evaluated. Sera of 14 patients with acute myocardial infarction contained, per liter, 84 to 236 U of total creatine kinase activity and 4.6 to 28.0 U of isoenzyme MB activity; corresponding ranges for sera from healthy lab technicians and patients with noncardiac disease were 36 to 277 and 0 to 2.6 U. MB isoenzyme activity for infarction patients rose and fell sharply within three days after the infarction. Atypical time-course patterns, MB isoenzyme activity remaining abnormally great for five days, were observed in serum from patients with prolonged atrial fibrillation and congestive heart failure or cardiomyopathy; the BB isoenzyme (1 to 5 U/liter) was also detected in sera of such patients but was absent in sera from infarcation patients. Quantification of column-isolated MB by the assay described is rapid, easy, specific, and extremely sensitive for measuring MB in the 1 to 10 U/liter range.

Lactate dehydrogenase isoenzymes were partially separated by use of a previously described column technique for creatine kinase [Clin. Chem. 20, 36 (1974)]. Extracts of lactate dehydrogenase-rich tissues were used to evaluate column resolution. Samples layered on mini-columns containing DEAE-Sephadex were eluted with Tris-buffered sodium chloride (100 and 200 mmol/liter). Lactate dehydrogenase activity in column effluents was measured by the Wacker method, and their isoenzyme content was assessed by electrophoresis on polyacrylamide gel. Dehydrogenase isoenzymes 3, 4, and 5 were separated from isoenzymes 1 and 2, and the separation was tissue-specific and reproducible. The electrophoretic technique for isoenzymes 3, 4, and 5 gave values about 20% lower than did the column technique. Sera from 15 healthy laboratory technicians contained total lactate dehydrogenase, isoenzymes 1 and 2, and isoenzymes 3, 4, and 5 in the ranges 94 to 152, 34 to 64, and 38 to 75 U/liter, respectively. Activities of sera from 15 patients with acute myocardial infarction (total lactate dehydrogenase) ranged from 212 to 800 U/liter and lactate dehydrogenase isoenzymes 1 and 2 ranged from 138 to 628 U/liter. Lactate dehydrogenase and creatine kinase isoenzymes were rapidly and easily measured after being simultaneously separated. The procedure is specific and sensitive for following the post-infarct time course of changes in isoenzyme activities.

We evaluated 16 claims made by Beckman Instruments, Inc. for its Enzyme Analyzer (System TR), under a rigid written protocol for the Product Evaluation Subcommittee of the Standards Committee of the College of American Pathologists. We found the following to be within the company's specifications: (a) accuracy and precision of the temperature control; (b) accuracy and precision of the sample and reagent pipets; (c) instrument precision, both within-run and between-day; (d) carry-over from a sample with activity greater than 1000 U/liter; (e) instrument-to-instrument variation; (f) analytical linearity; (g) analysis time; (h) correlation of the instrument-printed answer with the activity calculated manually from a strip-chart recorder; (i) precision of the instrument's built-in electronic "standard"; (j) effectiveness of the over-range indicators; and (k) correlation between results of these enzyme assay methods and those for kinetic methods used in our laboratory. The instrument performed well.

The fundamental equation describing radioimmunoassays under equilibrium conditions has been recast into a "working equation" in a form more directly applicable to the requirements of the analytical laboratory. Plotting total counts over counts bound vs. ligand concentration, which is conveniently linear over most of its course, is shown readily to yield quantitative data relative to binding site concentration and the equilibrium constant and to provide a means for deriving apparent labeled ligand concentration. Such data are helpful in establishing optimum assay conditions and can serve a continuing quality-control function. The working equation also characterizes the binder and tracer reagents used in the assay. The determination of working-equation parameters has been illustrated for the vitamin B-12 assay. Data are presented for seven different assay procedures, involving more than 600 calibration curves and 100 different lots of binding agent and tracer reagent, showing a consistently high correlation coefficient (r greater than 0.990), between ligand concentration and the response variable.

Any decrease in the availability of iron for incorporation into the heme moieties of hemoglobin results in an increase in the erythrocyte protoporphyrin concentration. Our aim was to compare protoporphyrin concentrations, determined spectrophotometrically, with body iron stores, as assessed from the amount of iron demonstrable by Prussian blue staining of bone marrow aspirates. The mean protoporphyrin concentration (175 mu-g/dl) in the erythrocytes of a group of patients with markedly decreased stainable marrow iron or no iron was significantly greater (P less than .001) than the mean concentration (76 mu-g/dl) in a comparable group with adequate bone marrow iron stores, except in the presence of certain interfering conditions. These results suggest that the erythrocyte protoporphyrin test may be a useful addition to the methods now available for assessing disorders of heme synthesis, the most common of which is iron deficiency.

We describe a simple, reproducible, discontinuous system for polyacrylamide disc gel-electrophoresis, with which the alkaline phosphatase isoenzymes in human serum can be fractionated. No sample preparation is needed. The isoenzymes are classified according to their electrophoretic mobilities (R-F values) and quantitated by peak area measurements from spectrophotometric scans. The four alkaline phosphatase isoenzymes usually present in normal sera, in order of descending mobilities (and designated according to principal tissue of origin) are: "fast" liver, "slow" liver, bone, and intestine. Sera of diseased patients show a greater variety of isoenzyme distribution patterns, but the most frequently observed patterns are the same as normal patterns. We conclude that the finding of "fast" liver only is not pathognomonic, as previously reported by others, and that information on relative distributions per se is not diagnostically useful, although information on specific increases in activity is useful. With this system, hepatobiliary disorders can be differentiated from other forms of liver and bone diseases.

A reaction of urea, o-phthalaldehyde and N-(1-naphthyl)ethylenediamine is described for measurement of urea by manual, continuous-flow, and kinetic methods. The continuous-flow system requires 25 mu-l of sample; 40 samples can be analyzed per hour. The kinetic method requires no enzymes, has no lag phase, and has good sensitivity. A major advantage of the reaction is that it occurs at a temperature of 37 degrees C or lower. The results obtained by all three methods agree well with those for a continuous-flow procedure in which diacetyl is a reagent.

Sources of variation in assays of aspartate aminotransferase (EC 2.6.1.1) activity were examined in an interlaboratory survey and through an examination of materials used as calibration materials in these assays. Four highly stable lyophilized specimens containing human cytoplasmic enzyme, with activities of 0, 22, 46, and 96 U/liter at 30 degrees C and optimal substrate concentrations, were assayed by 319 laboratories. Mean values obtained on these specimens by laboratories using 2,4-dinitrophenylhydrazine kits varied among manufacturers and deviated from values expected from this procedure. The average coefficient of variation (CV) with these kits was greater than 20%. Automated continuous-flow procedures with use of diazonium salt showed the best precision (av CV, less than 10%). However, the automated continuous-flow malate dehydrogenase/NADH coupled method produced an average CV greater than 20%. Results from each of the automated methods were related to a reference malate dehydrogenase/NADH coupled continuous kinetic assay method by temperature relationships alone. Mean values from manual diazonium salt procedures were 1.7-fold greater than similar reference values (av CV was 18%). The higher results were attributed to the use of poorly-defined units and to an artifact caused by chromophore stabilizers in this procedure when aqueous samples are used. The average CV in continuous kinetic methods varied among kit manufacturers, ranging from 6 to 28% for the specimen of highest activity. Variations in results were much larger at 366 nm than at 340 nm than at 340ity. Variations in results were much larger at 366 nm than at 340 nm. Interassay relationships of these methods are presented. Concentrations of pyruvate in commercially available calibration materials differed between manufacturers, varied in stability, and deviated from the expected concentration. For some colorimetric assays the precision attained on reported absorbance values for the enzyme specimens was of the same order of magnitude as that for pyruvate standards. Other sources of error are revealed by the interlaboratory survey. The value of commercially available sources of enzyme activity as calibration or control materials was assessed by evaluating the following properties: activity at suboptimal concentrations of L-aspartate or 2-oxoglutarate, temperature effects, preincubation lability owing to aspartate and phosphate, pyridoxal phosphate saturation, contamination with glutamate dehydrogenase, and manufacturer's rated activity. These properties are compared to those of human cytoplasmic enzyme in a human serum matrix.

We describe an improvement in the Levy and Procknal method [J. Pharm. Sci. 57, 1330 (1968)] for determination of salicylic acid and its metabolites in urine. Salicylic acid and salicyluric acid are successively extracted from 1 or 2 ml of urine (acidified with HCl) by two 10-ml portions each of carbon tetrachloride and ethylene dichloride. The extracts of each solvent are shaken with 5 ml of ferric nitrate solution (a 10-fold dilution of 17 g of Fe(NO-3)-9H-2O in 1 liter of 70 mmol/liter HNO-3). The aqueous phases are centrifuged and their absorbances measured at 530 nm. For total salicylate, 3 ml of urine and 3 ml of HCl are heated in a partially evacuated serum vial at 100 degrees C for 16 h and then salicylic acid is assayed in the hydrolyzed sample. Recovery of a weighed oral dose of sodium salicylate in urine was 105.4%; it was 127.9% by the Levy and Procknal method for the same sample. The improved method is faster and more accurate.

We wanted to know if incubation time and temperature for many radioimmunoassay methods could be standardized, to decrease assay time and so improve efficiency. Percentage binding was determined for triiodothyronine, thyroxine, digoxin, digitoxin, testosterone, aldosterone, estradiol, and diphenylhydantoin when the reaction mixtures were incubated at 6-8, 22, or 37 degrees C for various periods of time. In all methods tested, binding of antigen to antibody was greatest when the reaction mixtures were incubated at 6-8 degrees C, less at 22 degrees C, and least at 36 degrees C. Maximum binding occurred within 30-60 min at each temperature for all methods tested. Hence, it is possible to standardize the incubation time and temperature for these eight radioimmunoassay methods to 60 min at 6-8 degrees C.

The procedure prescribed for the Schwarz/Mann 125-l-digoxin kit was modified with regard to pipetting and counting procedure. Incubation time with dextran-coated charcoal was also investigated. The modifications resulted in a significantly higher precision wihout introduction of a systematic error and the analysis time per eight-tube batch was decreased by 20 min.

A thermostatted reaction cuvet, operating under computerized or manual temperature control in the ultraviolet or visible region, is described and evaluated. The cell was designed for use with the automated chemistry system described earlier [Clin. Chem. 19, 1114 (1973)], but can readily be adapted for other applications. The entire 3-ml cuvet assembly warms from ambient temperature to 37 degrees C in less than 10 min, with plus or minus 0.15 degrees C stability; the long-term stability is plus or minus 0.05 degrees C; temperature recovery time after washing or reagent addition is less than 3 min. The optical pathlength is 10.00 mm and the carryover volume is 18 mu-l.

An alkaloid of tobacco, nicotine, affected the clot-formation property of the enzyme, thrombin, on the substrate, plasma or fibrinogen (thrombin time). Higher concentrations of nicotine retarded the clot-formation property of thrombin. By decreasing the nicotine concentration in the clotting mixture, the clotting time of thrombin was accelerated. Nicotine also modified the clot formation property of plasma or fibrinogen to thrombin, and this effect was dose dependent. From this experimental evidence, it is suggested that nicotine does alter the clot-forming properties of thrombin on fibrinogen.

Sampling tube and fingertip contamination were found to present potential problems in the collection of samples for micro blood lead analyses. Large differences between micro screening and macro confirming lead levels were frequently observed when the time between collection of the two samples was 1-2 weeks. The magnitude of these differences decreased as macro blood lead concentration increased and were apparently a result of episodic lead ingestion in the population.

Recombination frequencies were determined for 15 independently isolated auxotrophs of C. crescentus crossed pairwise in all possible combinations. The results indicate that the mutants may be grouped into at least two types: "fertile" strains, which recombine with all other mutants at frequencies ranging from less than 10-6 to 3 times 10-2, and "nonfertile" strains which recombine with fertile strains at high frequencies and with other nonfertile strains at low or negligible frequencies. Several lines of evidence indicate a polarized inheritance of markers. Two of these are (1) the preferential inheritance of unselected markers from the nonfertile parent in fertile times nonfertile crosses, and (2) the consistent ordering of markers based on the frequency at which the mutants recombine with each of the three fertile strains. Although the evidence is not conclusive at this point, the results are most consistent with conjugation at the mechanism of gene transfer in these bacteria.

Many mutants affecting meiosis increase the occurrence of aneuploid meiotic products. In Neurospora, mutants of this type cause ascospore abortion which is reflected by an increase in the proportion of ascospores failing to develop black pigment. The usefulness of the criterion white-ascospore-production as a signal for the presence of a mutant affecting meiosis is demonstrated by the recovery of several such mutants. One of these is mei-1 (meiotic-1), a recessive mutant on linkage group IV. Crosses homozygous for mei-1 produce 90% white ascospores (vs. 5% in wild-type crosses). Viable ascospores, invariably black, are always disomic for one or more linkage groups; the chromatids assorted into viable ascospores do not engage in crossing over in meiosis. The distribution of viable ascospores in individual asci suggests that all meioses are defective in the first meiotic division, and that most meioses are defective in both divisions.

A dominant gene Su(kau-2) partially suppresses the effect of an apparently unlinked recessive kau-2. Gene kau-2 blocks chemical induction of conjugation in Paramecium aurelia syngen 8 when solutions of acriflavine + either KCl or MgCl-2 are used. Wild-type cells are induced to conjugate in either solution. When cells homozygous for kau-2 also have gene Su(kau-2), they are still uninducible in the solution containing KCl, but become inducible in the MgCl-2 solution. Analysis of the concentrations of solutions which are effective in induction of conjugation of various genotypes shows that the action of Su(kau-2) is not a simple restoration of wild-type phenotype since certain novel features of the suppressor can be seen. Analysis of the duration of ciliary reversal of various genotypes suggests that one necessary step in chemical induction of conjugation is a certain magnitude of depolarization of the surface membrane of the cell.

Evidence for correlated responses to selection was investigated in lines of rats selected for 13 generations for high (U line) and low (D line) 3-9-week gain in comparison with random-bred control lines (R and C lines). The increase in 3-9-week gain in the U lines was shown to be due largely to an increase in 9-week weight, although 3-week weight also increased in these lines. In the D lines, where a marked decrease in 3-9-week gain was observed, this was found to be due to a large decrease in 9-week weight and no detectable change in 3-week weight. The average 2-week litter weight, a measure of the lactational performance of the dam, was significanly greater in the U lines than in the D lines. Selection for 3-9-week gain in these lines of rats led to changes of litter size at birth in the same direction as that of selection. This resulted in a significantly higher litter size in the U lines than in the D lines. The number of rats alive 2 and 9 weeks of age and the percentage of mated females pupping were similar in the U and D lines but lower in these lines than the random bred C lines, providing evidence for a reduction of "fitness" in the selected lines. Carcass composition was studied for all lines at the 11th generation of selection. Carcass composition, in terms of water, fat, ash and protein, was similar in the R and C lines. The U lines had more water and lesss fat than the R or C line. The D lines had similar carcass composition to the R and C lines. It is suggested that these selected and random-bred lines of rats are potentially useful animals to investigate further the developmental and physiological mechanisms which control growth.

The effectiveness of selection for 3-9 week gain was examined in a population of rats with a history of past selection for high 3-9 week gain. Lines were selected for high (U line) and low (D line) 3-9 week gain with two replicates of each line. Two randomly selected lines were also kept, one originating from the same base population as the two selected lines (R line) and the other originating from a population that had been randomly mated for the previous 27 generations (C line). Two replicates of each of these lines were kept. After seven generations of selection, a randomly selected line (relaxed line) was formed from each of the two upward- and each of the two downward- selected lines. Results have been presented for 13 generations of selection. The environmental trend for 3-9-week gain, as indicated by the randomly selected R and C lines, was consistently negative in all four lines. Realized heritabilities calculated by deviating the response to selection from the trend in the R or C lines resulted in non-significantly higher values in the D lines than the U lines. Six generations of relaxation of selection indicated no effect of natural selection in the U lines or the D lines. The relative magnitude of the drift, error and common environmental variances were estimated by the methods given by HILL (1971). The estimates of these parameters then led to calculation of the degree of bias in the sampling variances of the realized heritability estimates. As was predicted by HILL (1971), estimates of the variance of realized heritabilities obtained by using standard regression techniques were less than those obtained using HILL'S formulae. The results are discussed in relation to other similar studies with rats and mice.

In a recent not in this journal (MARUYAMA 1973), one of us has considered, for a certain genetic model, the variance of the distribution of the number of loci having a given gene frequency. The formula given is incorrect. This brief note considers this problem and notes the correct solution in one particular case.

NEI and ROYCHOUNHARY have developed an inequality relationship between the expected values of (j-x - g)-2 and (ĝ - g)-2 where j-x is a biased and g is an unbiased estimate of population homozygosity g. Their inequality is somewhat weak and can be improved, as is demonstrated in this paper.

The number of precaudal vertebrae in the three African cercopithecine species are analyzed, with two definitions for thoracic and lumbar vertebrae compared. It is found that generic averages obscure some rather substantial differences at the species level for both Cercopithecus and Cercocebus. Further, when zygapophysis structure is used to define vertebral type, rather than presence or absence of rib facets, there is a substantial change in thoracic and lumbar averages that may be important from a functional (locomotion) standpoint.

This paper focuses on the development of a theoretical perspective within which it is possible to empirically define parental mediation in interactions between grandparents and grandchildren. Using socialization theory and studies conducted by the writer and a colleague, eight independent dimensions of parental mediation have been identified. This makes it possible to develop measurement indices for testing the postulate that parents act as mediators between the grandparent and grandchild generations in socializing both into their respective roles and thereby influencing the nature of their relationship.

A review of the current theoretical literature continues to refute the earlier held viewpoint that the American family is an isolated unit with little or no contact with the extended family. Nine theoretical models are presented supporting the existence of rather definitive patterns of intergenerational exchange. Additionally, explanation is given as to how these patterns of exchange operate between generations and why they change over time. Suggestions are presented why the middle family unit of the three generational system eventually emerges today as the center of power or most influential unit.

Attitudes toward young, middle-age, and old persons were studied in 1000 children (grades 6, 8, 10, 12). Three newspaper photographs were presented to the children, who estimated the persons' ages and wrote stories about each photograph in his preferred order. Scores from a semantic differential which provided three factors, Evaluation, Affect, and Activity-Potency, were used in a three-way analyses of variance to analyze further children's attitudes. The overriding impression from these findings is that these school children do not share the allegedly general, negative attitude toward old age. The age estimates showed judgmental accuracy and were remarkably uniform in both central tendency and variation. The overall order of choice was young person, first; old person, second; and middle-age person, last.

There is an ever-growing number of male retirees in the American society. The present study was conducted to try to determine the effect of the voluntary and involuntary retirement on emotional satisfaction, usefulness, self-image, emotional stability, and interpersonal relationships in aged males. Significant differences were found among the participants in each of the areas. Voluntary retirement tends to have a more positive influence on the retiree along each dimension.

Most research tends to focus on the husband's attitudes toward retirement while overlooking the wife's evaluation of this event. In this study interviews with wives whose husbands were retired or approaching retirement suggested that a variety of orientations toward their husbands' retirement was present. Some women expressed grave reservations; others looked forward to it; still others had no opinion. It is felt that an understanding of the wife's reaction to her husband's retirement can be useful in understanding the adjustments that both husband and wife may have to make in their relationship to each other.

This study examines five specific assumptions of crisis theory as this orientation relates to the prediction of life satisfaction following retirement. Pre-retirement and post-retirement interviews were conducted with a group of 114 men (mean age 68.2 years) residing in an urban area of central Missouri. The data reveal a significant decline in life satisfaction as predicted. Contrary to the theory, however, no significant changes in role behavior in three related areas-family, voluntary associations, and community--were found subsequent to retirement. In addition, the role changes accompanying retirement were not significantly associated with negative changes in satisfaction. Also, increases in role performance were not significantly related to positive changes in satisfaction. Finally, the correlation between work commitment and change in satisfaction proved negative and non significant. On the other hand, the correlation between work commitment and the desire for subsequent employment was negative and significant. In sum, four of the five assumptions of crisis theory do not receive support on the basis of the data.

This study is a longitudinal investigation of the relationship between age and subjective outlook. Over the years, a number of theoretical positions have been introduced to either account for or to minimize age differences in attitudes, values and beliefs. The author has organized these theories of aging into three basic sociological fremeworks or models: the "generations" model, the "age status" model and the "illusion of differences" model. Using a relatively simple methodological desihn, hypotheses derived from these models were tested through secondary analysis of survey data. Strong support was found for the "generations" hypothesis, weak support for the "age status" hypothesis, and no support at all for the "illusion of differences" hypothesis.

Sodium n-octylbenzene-p-sulfonate was successfully used in place of sodium dodecyl sulfate in SDS-polyacrylamide gel electrophoresis. This modification of the usual technique made it possible to scan the polyacrylamide gel for the distribution of the surfactant by measurement of UV absorption. It was found that a band electrophoresed in advance of the complexes formed between protein polypeptides and the surfactant. The band could be observed even in the absence of protein polypeptide, and was ascribed to micelles derived from surfactant added in excess to the sample solution. The complexes were found to be detectable by scanning at 261 nm, usually with better sensitivity than by scanning at 280 nm. Thus, this modification of SDS-polyacrylamide gel electrophoresis is useful both to investigate what is going on in the gel during electrophoresis and to improve the sensitivity of detection by UV scanning of protein complexes.

1. A unique subclass of ceramide oligosaccharides from whole tissue of the fresh-water bivalve Corbicula sandai has been isolated. Through the use of chemical, enzymatic, and physical techniques, two novel glycolipids were characterized as mannosyl-beta (1 leads to 4)-glucosyl ceramide and mannosyl-alpha (1 leads to 4)-mannosyl-beta (1 leads to 4)-glucosyl ceramide. 2. The components of fatty acids and long chain bases in the two glycolipids were analyzed by gas-liquid chromatography and were further identified by mass spectrometry. The data show that, with respect to the major components, both lipids have similar caramide moieties.

Some physicochemical properties of crystalline alpha-amylase [EC 3.2.1.1] isolated from normal human urine were investigated. A crystalline preparation of the enzyme was homogeneous on velocity sedimentation, gel filtration, and sodium dodecyl sulfate disc electrophoresis, and its molecular weight was estimated to be 4.5 X 10-4. However, electrophoretic analyses revealed that the crystalline alpha-amylase consisted of at least five isozymes. The implications of the experimental results are discussed.

The modification of tubulin cystine and cystine residues to S-sulfocysteines caused a distinct separation of the alpha and beta subunits in a continuous sodium dodecyl sulfate polyacrylamide gel system. The well-separated subunit bands permitted investigation of the phosphorylation of alpha and beta tubulin subunits. The incubation of tubulin fraction with [gamma-32P]ATP demonstrated that both subunits were phosphorylated in vitro. The incorporation of 32-PO4 into sea urchin eggs, however, failed to cause phosphorylation of tubulin in vivo.

L-Gulono-gamma-lactone oxidase [EC 1.1.3.8] was purified 80-fold from rat liver microsomes. In confirmation of our previous finding with a cruder preparation, the purified enzyme was shown to contain an L-gulono-gamma-lactone-reducible pigment as a prosthetic group. This pigment was not liberated from the protein by acid ammonium sulfate, 10% trichloroacetic acid or 2 M area, but was effectively released by proteolytic digestion. The pigment thus released showed a reduced-minus-oxidized difference spectrum characteristic of a flavin compound. The pigment was liberated from a trichloroacetic acid-treated preparation of the enzyme by pronase digestion and purified by Florisil column chromatography and paper chromatography. The absorption spectrum as well as the fluorescence emission and excitation spectra of the purified pigment indicated that it was actually a flavin peptide. It was, however, different not only from FMN but also from flavin peptides isolated from other sources such as succinate dehydrogenase [EC 1.3.99.1] and monoamine oxidase [EC 1.4.3.4] as regards the pH dependence of fluorescence intensity and the Rf value on thin-layer chromatography. A preliminary analysis showed that the purified flavin compound contained several amino acid residues. Alkaline photolysis of the purified flavin peptide suggested that the isoalloxazine ring of the flavin is involved in its binding to the peptide. The hypsochromic shift of the absorption peak in the near-ultraviolet region suggested further that the linkage between the flavin and the peptide may be mediated by the 8-methyl group of the isoalloxazine nucleus. It can be concluded that the prosthetic group of gulonolactone oxidase is a flavin which is covalently bound to the enzyme protein.

During the fractionation of various enzymes concerned with DNA synthesis from the postmicrosomal supernatant fraction of various tissues, DNA polymerace [EC 2.7.7.7], thymidine kinase [EC 2.7.1.75], dTMP kinase [EC 2.7.4.9], deoxycytidine kinase [EC 2.7.1.74], and deoxycytidine monophosphokinase (dCMP kinase) [EC 2.7.4.14] were found in the pellet fraction of postmicrosomal supernatant. Further, the uridine kinase [EC 2.7.1.48] and aspartate transcarbamylase [EC 2.1.3.2] activities of postmicrosomal supernatant from various tissues were also present in this pellet fraction. The activities of DNA polymerase, thymidine kinase, uridine kinase, and aspartate transcarbamylase from normal and regenerating rat liver, and Yoshida sarcoma were higher in the pellet fraction than in the supernatant. On the other hand, the activities of dTMP kinase, dCMP kinase, and orotidine-5'-phosphate decarboxylase [EC 4.1.1.23] were lower in the pellet fraction than in the supernatant. The pellet fractions of regenerating rat liver and Yoshida sarcoma showed a remarkable incorporation of various precursors (thymidine, dTMP, deoxycytidine, and dCMP) into DNA in the presence of a suitable DNA template, ATP and all four deoxynucleoside 5'-triphosphates for DNA synthesis. Normal adult rat liver catalyzed a much smaller incorporation of all these precursors, except for dCMP.

An enzyme that releases acylamino acid from amino terminal acylated peptides and proteins has been isolated from rat liver in a highly purified form bya six-step procedure comprising extraction from liver homogenate, ammonium-sulfate fractionation, heat treatment, chromatography on columns of DEAE-cellulose and hydroxylapatite and gel filtration on a Sepharose 6B column. About 1,500-fold purification was achieved from the liver homogenate. The purified enzyme preparation showed a single band on polyacrylamide gel disc electrophoresis. The enzyme specifically released acylamino acids from several amino terminal acylated peptides and proteins with different rates of hydrolysis depending on the acyl groups, terminal amino acid sequences and tertiary structure of the acyl protein substrates. The present enzyme may be useful for the removal of the N-terminal acylamino acid from some N-terminal blocked peptides and proteins in amino acid sequence analysis. The molecular weight of the purified enzyme was estimated to be 360,000-420,000 by gel filtration and sucrose density gradient ultracentifugation. Disc electrophoresis of the acylamino acid-releasing enzyme on SDS-polyacrylamide gel suggested that the enzyme consisted of five or six identical subunits having a subunit weight of about 75,000. The N-terminal residue of the subunit, which consisted of a single polypeptide chain, was glycine. Other properties of the enzyme, including isoelectric point, the effects of metal ions and several chemical reagents on the enzyme activity, pH optimum, and amino acid composition were also examined.

Gas-liquid chromatography is utilized for the determination of thermodynamic solution parameters for various organic solutes at infinite dilution in the meso- and isotropic phases of cholesteryl palmitate. The thermodynamic data and trends in values of the activity coefficients for the solutes are discussed in relation to their structure and to the orientations of the liquid crystal.

The derivatization of benzenesulphonamide, N-ethylbenzenesulphonamide and N-phenylbenzenesulphonamide with trifluoroacetic and heptafluorobutyric anhydride and pentafluorobenzyl bromide has been studied. A rapid quantitative acylation is obtained in benzene in the presence of trimethylamine. Pentafluorobenzylation is performed by the extractive alkylation technique using tetrabutylammonium as counter ion and methylene chloride as solvent. Less than 20 min are required for a quantitative derivatization. The derivatized sulphonamides have a hydrophobic character, making them very suitable for gas chromatography. Trifluoroacetylation and heptafluorobenzylation decreases it. The derivatives have a high electron-capture detector response (minimum detectable quantity, 1-2 X 10-minus 16 moles/sec). A standard curve is given for the determination of N-phenylbenzenesulphonamide as trifluoroacetyl derivative in the range 1.8-90 ng/ml.

A single-step extraction method and thin-layer identification techniques capable of testing a wide variety of drugs of abuse are presented. These techniques are well suited for large and/or small drug programs involved in urine testing because they provide substantial economic benefits and improve clinical functioning. The drugs are absorbed on a 6 X 6 cm piece of paper loaded with cation-exchange resin and then eluted from the paper at pH 10.1 using ammonium chloride-ammonia buffer. The simultaneous thin-layer detection of sedatives, hypnotics, narcotic analgesics, central nervous system stimulants and miscellaneous drugs is accomplished by spotting the solution of extracted residue on a 20 X 20 cm Gelman pre-coated silica gel glass microfiber sheet (ITLC Type SA). A two-stage solvent system is used in order to obtain a chromatogram with optimum separation of a wide range of drugs. This system can separate methadone and/or cocaine from propoxyphene, methaqualone, methylphenidate, pentazocine, pipradrol, Doxepin, chlorpromazine, phenazocine, naloxone, naltrexone, imipramine and trimeprazine; amphetamine from phenylpropanolamine and dimethyltryptamine; codeine from dextromethorphan; methamphetamine from dimethyltryptamine, etc. Different detection reagents are then applied in succession to different marked areas of the developed chromatogram. This elegant method of extraction and spraying has enabled us to detect morphine base at a sensitivity level of 0.15 mug/ml, amphetamine sulfate at 1.0 mug/ml, methamphetamine hydrochloride at 0.5 mug/ml, phenmetrazine hydrochloride at 0.5 mug/ml, codeine phosphate at 0.5 mug/ml, methadone hydrochloride at 1.0 mug/ml, secobarbital at 0.36 mug/ml and phenobarbital at 0.5 mug/ml in urine. The minimum volume of urine needed to achieve these sensitivities is 20 ml. The cost of analysis per urine specimen using these techniques for concomitant screening of these drugs is less than US$ 1.

A group of 25 steroidal glucosiduronic acids was chromatographed on paper chloroform-formamide in the presence of several different liquid ion exchangers. Chromatograms were run also in three Bush-type systems. RF values were converted into RM values and the data were correlated by use of a series of regression equations of the type RM(Y) = a-RM(X) + b, in which X designates a standard system to which each other system (Y) is compared. The ratio of the slope a to the correlation coefficient r (i.e., a/r) is a measure of the resolving power of system Y relative to the standard system; intercept b, in association with slope a, is an indication of the polarity of system Y relative to X. The correlation coefficient r and the standard error of estimate sy-x are indications of whether solvent systems Y and X have very similar or relatively different resolving properties for a group of solutes. The regression equations are useful for correlating chromatographic data obtained from a group of compounds in several solvent systems. Properties of the chromatography systems are discussed and the relative importance of ion exchange and hydrogen bonding with the various solvent systems is pointed out. Delta RMg and delta RMr values are given for functional groups at several locations in the conjugates for ten of the chromatography systems.

Existing urine testing techniques in a drug abuse urine screening program with their capacity to analyze urine specimens per day are discussed. The start-up cost using each technique and cost per specimen are presented. A single step extraction technique using ion-exchange paper to absorb drugs prior to thin-layer chromatography (TLC) as reported by these laboratories will cost $0.58 per specimen, for testing the entire aray of drugs of abuse (at least 9-14 tests per specimen). Sensitivity reported using TLC technique for the morphine base is 0.15 mug/ml (minimum volume of urine needed 20 ml), 0.10 mug/ml if the volume of urine available is 30-35 ml, and 0.07 mug/ml if the volume of urine available is 43-50 ml.

The functionally excellent flash-heater methylation, ethylation and butylation techniques have been extended to include the higher alkyl homologs. Phenobarbital and diphenylhydantoin have been alkylated using the tetraalkylammonium hydroxides in which the alkyl group ranges from methyl to hexyl. The gas chromatographic properties of the resulting alkyl derivatives have been investigated.

Barbiturates are a source of interference in the estimation of paracetamol by both UV spectrophotometry and gas-liquid chromatography (GLC). Experiments have shown that the interference by barbiturates on GLC can be avoided by benzoylation (in aqueous solution) of the paracetamol. This O-benzoyl derivative can be N-silylated to give an additional identification parameter. The method, which requires ml of sample, will quantitatively and qualitatively estimate "free" paracetamol in plasma and in post mortem blood in the range of 2-40 mug of drug per millilitre of sample.

Procedures for the ligand-exchange chromatography of amino acids on copper-, cobalt-and zinc-Chelex 100 have been examined. Ligand exchange on the copper complex affords a simple and rapid method for the removal of amino acids (except for aspartic and glutamic acids) from dilute solutions. The influence of the pH on the binding of amino acids to the metal complex was also studied. The bound amino acids could be eluted with ammonium hydroxide which also causes a slight metal leakage. Chromatography on cobalt- and zinc-Chelex 100 showed that only the basic amino acids were quantitatively attached to these complexes at pH 8.3-9.5, whereas the others were predominantly EXCLUDED. This procedure can be used for the selective concentration and removal of basic amino acids in the presence of other amino acids.

Chemical signatures of phenmetrazine hydrochloride were studied by gas chromatography. The inter-batch variations of the signatures were found to be large whereas the intra-batch variations were usually small. The method is used for the tracing of seized phenmetrazine hydrochloride samples to common sources, which in turn may permit further tracing back to chains of illicit distribution of this drug. The applicability of the method to other narcotics is also discussed.

A gas chromatographic separation of dihydroxy- from monohydroxycannabinoids by the use of homologous trialkylsilyl derivatives is discussed. Trimethylsilyl derivatives produced a group of peaks containing both sets of compounds, sometimes poorly resolved, whereas by increasing the alkyl chain length to n-butyl complete fractionation into two groups, was achieved. The mass spectra of these derivatives resembled those of the trimethylsilyl derivatives with the addition of a set of ions resulting from estimation of the Si-alkyl chains as olefins.

Five trimethylene-interrupted methyl octadecadiynoates, C18 delta-2a,-7a; delta-3a,-8a; delta-4a,-9a; delta-5a,-10a and delta-6a,-11a, and the corresponding cis,cis-octadecadienoates were synthesized, and their gas-liquid chromatographic properties were studied on Apiezon L, diethylene glycol succinate polyester and Silac 10C stationary phases. The equivalent chain lengths of these esters have been determined, and the separation of mixtures and the prediction of gas chromatographic behaviour of these isomers are discussed.

The dimethyl silicone elastomer SE-30 has been chosen as the preferred liquid phase for the gas-liquid chromatographic analysis of drugs, and retention index data have been compiled for 480 drugs and commonly occurring chemicals such as plasticisers. The inter-laboratory variation in measurement of retention indices has been measured for three drugs in eleven laboratories and the standard deviations were between 20 and 15 retention index units.

Six patients with hereditary anagioedema (HAE) undergoing 7 episodes of dental surgery received transfusions with fresh frozen plasma one day before surgery. Although the morbidity observed in these patients following similar procedures had been high, no significant complications of surgery were noted with this therapy. Thus, fresh frozen plasma infusion appears to provide a safe and effective method of prophylaxis in patients with HAE. Following infusion of fresh frozen plasma, serum levels of C4 esterase inhibitor (C1EI) rose transiently, and then fell to preinfusion levels within 1 to 12 days. In all but one patient the rise in C4 was greater than could be accounted for by the amount of C4 infused. In no patient did the level of C1EI or C4 rise to within the normal range. The data raise the question of the role of C1EI in the pathogenesis of angioedema in these patients.

The diverse clinical syndromes characterized by asthmatic symptoms, transient pulmonary infiltrates, and eosinophilia have tended to obscure the specific association of one such entity with filarial infections. Serum IgE levels were determined before and after therapy in a group of well-characterized patients with tropical eosinophilia (TE), studied earlier in Singapore. The mean serum IgE level in 14 cases before treatment with diethylcarbamazine was 2,355 ng. per milliliter, with a trend but statistically nonsignificant decrease in levels to 600-1,000 ng. occurring 8 to 12 weeks after therapy. Leukocyte and eosinophil counts showed a rapid reduction after treatment, and although mean complement-fixing (cf) titers to Dirofilarial antigen tended to decrease, they were not significantly reduced until 5 to 6 weeks. The historical development of evidence supporting the filarial etiology of TE was reviewed. Many basic questions engendered by the clinical syndrome of tropical eosinophilia make it an excellent model for study of the immunopathology of parasitic infections.

Defects in ventilatory function can persist for considerable periods of time following the amelicoration of the signs and symptoms of acute episodes of asthma. Serial spirographic and lung volume determinations in such patients demonstrate that the pattern of resolution of these abnormalities is such that their subtlest manifestations are depressed flow rates in the mid vital capacity range and/or elevations in residual volumes. These changes are believed to represent the effects of residual obstruction that is located in the airways in the periphery of the lung. Recent studies suggest that this residua is capable of influencing the lung's response to asthmogenic stimulis, and imply that it may be beneficial to place asthmatics on continuous therapy for as long as they have alterations in lung function.

A reliable method for obtaining osteoclast activating factor (OAF) in the culture medium of phytohemagglutinin-activated peripheral blood leukocytes is described. OAF was detected by its ability to stimulate resorption of fetal rat bone in organ culture. Most bone resorbing activity was released by activated leukocytes during the first 24 hours of culture, well before -3H-thymidine incorporation was increased. Cultures maintained for longer than 3 days showed a decrease in OAF activity. Stimulated leukocytes cultured in medium with as little as 0.01 per cent plasma showed increased -3H-thymidine incorporation and released as much OAF as leukocytes cultured with 20 per cent plasma. OAF release was stimulated by pokeweed mitogen and concanavalin A as well as by phytohemagglutinin.

The effects of feeding chenodeoxycholic acid (CDC) on biliary lipid composition, on the rate-limiting enzymes of hepatic cholesterol and bile acid synthesis, and on hepatic cholesterol and bile acids were determined in hamsters. The goals were to study the mechanism and duration of the cholesterol desaturation action of CDC. Administration of CDC for 30 days significantly increased the biliary bile acid and lecithin to cholesterol ratio and the percentage of CDC in bile (p less than 0.01). These effects persisted for 20 days after discontinuing CDC (p less than 0.01) and were no longer evident at 30 days. HMG CoA reductase and 7 alpha-hydroxylase activities were significantly reduced by CDC (p less than 0.01). After discontinuing CDC, these effects persisted for 10 days at which time HMG CoA reductase was still decreased by 50 per cent (p less than 0.01) and 7 alpha-hydroxylase by only 12 per cent (p less than 0.01) and were no longer evident by 20 days. Hepatic cholesterol did not change, while hepatic CDC was significantly elevated throughout the experiment. (1) CDC has a salutory effect on biliary lipid composition while causing an increase of exogenous CDC in bile and a decrease of endogenous cholesterol synthesis. (2) The persistence of decreased cholesterol synthesis and of improved biliary lipid composistion after discontinuing CDC provides a rationale for studying this in man and then testing intermittent CDC regimes for gallstone dissolution.

The relationships between the amount of calcium absorbed and the quantity ingested was evaluated in 180 adult humans. Absorption was measured from the concentration ratio of concurrently administered oral and intravenous calcium isotopes. Intake ranged from 0.163 to 7.48 Gm. Ca per day. In 14 subjects, intakes were artificially elevated for purposes of this study. All others were studied at their usual intake levels. Absorption (Ca Abs) was found to follow a curvillnear relationship with intake (Ca-D), and was characterized by the following equation: Ca Abs equals 0.1541 - Ca-D plus 0.3127[exp(-1.0539 - Ca-D)] - Ca-D. The exponential term of this equation provided the major component of total absorption at intakes below 0.8 Gm. per day, but fell to negligible values when intake reached 2 to 3 Gm. per day, above which absorption was characterized by a simple linear function of intake. We found that there was no detectable upper limit to absorption capacity, which, at the 7.48 Gm. intake level, averaged more than 1.0 Gm per day. The observed mathematical description is consistent with the generally recognized inverse relationship between absorption efficiency and intake. At the same time it indicates that a component of absorption is independent of control mechanisms and is related solely to intake. A more general form of the foregoing equation, suggesting provision for other physiological variables such as growth hormone and cortisol, is proposed and discussed.

To study the function of globin-chain genes, in vitro synthesis of globin was measured in reticulocytes concentrated from the peripheral blood of 7 subjects doubly heterozygous for an alpha-chain abnormality (Hb G-Philadelphia) and a beta-chain abnormality (Hb S or C). Each had a deficit of alpha-chain synthesis compatible with an alpha-thalassemia-like syndrome. The data are also compatible with the quantitative expression of variable reduplication of the alpha-chain locus in man.

This study was performed to identify the efferent pathways which mediate vasodilation during activation of the coronary chemoreflex and to compare the reflex responses in vessels in skeletal muscle and skin. Reflex vasodilator responses (decreases in perfusion pressure) were measured in innervated, perfused gracilis muscle and hindpaw of dogs during activation of the coronary chemoreflex with intracoronary injections of nicotine. Reflex vasodilator responses to intracoronary nicotine (1.25 and 2.50 mu-g per kilogram) averaged -14 plus or minus 5 (S.E.M.) and -34 plus or minus 6 mm. Hg, respectively, in muscle, but only -5 plus or minus 2 and -10 plus or minus 4 mm. Hg, respectively, in paw. Atropine, tripelennamine, and propranolol did not alter the vasodilation. Guanethidine blocked reflex vasodilation in muscle. The reflex vasodilator responses in paw were slight and were not significantly attenuated by guanethidine. The results indicate that sympathetic cholinergic pathways to skeletal muscle do not participate in the coronary chemoreflex. The reflex vasodilation in muscle results from withdrawal of adrenergic constrictor tone. The efferent pathway demonstrates that the coronary chemoreflex does not produce striking withdrawal of adrenergic tone in paw. The results indicate, therefore, that activation of the coronary chemoreflex results in greater withdrawal of adrenergic constrictor tone and greater vasodilation in muscle than in skin.

Total sulfur-containing amino acids have been found to be the first limiting amino acid in several foods in comparison with human amino acid requirements. Addition of methionine in appropriate amounts to these foods might be expected to improve protein value. Economically, DL-methionine would be preferable to L-methionine for this purpose. However, the comparative tuilization of L- DL-, and D-methionine is unclear. The objective of the current project was to compare the effectiveness of L-, DL-, and D-methionine supplementation of diets based on a food product known to be low in methionine value for human subjects. "Instant" oatmeal was fed to adult subjects to provide 4.0 g of nitrogen/day. In randomly arranged periods, these diets were supplemented with L-, DL-, or D-methionine at two levels (0.58 and 1.16 g of methionine/day). An unsupplemented diet was used in a control period. Diets were adequate in vitamins, minerals, and energy. Mean nitrogen balances of subjects while receiving the L-methionine supplements at the 0.58 and 1.16 g levels were minus0.10 and +0.06 g of nitrogen, respectively. At similar levels of DL-methionine supplementation, nitrogen balances were minus0.12 and minus0.15 g of nitrogen, respectively, and minus0.24 and minus0.18 g of nitrogen with D-methionine supplementation. The mean nitrogen balance when no supplement was used was minus0.22 g of nitrogen. Thus, D-methionine is seemingly poorly utilized by the human. Urinary methionine excretion data supported these results.

It has now been universally accepted that zinc deficiency interferes in some way with wound healing, but the claims that the addition of zinc supplements to the normally nourished rat accelerates wound healing to super-normal levels has, on investigations, produced contradictory results. In this study the rate of healing of granulating wounds on the backs of two species of animals, the rat and the guinea pig, has been studied when supplements of zinc salts were given in association with a normal diet. The zinc supplements were administered either orally, parenterally, or topically. There was no difference in the rate of healing in either species of animal given zinc supplements by any of the routes used.

Experiments were conducted to determine the absorption of various dietary fatty acids and glycerides singly and in mixtures. Chickens with or without cannulated bile ducts or ligated pancreatic ducts were used to evaluate the absorption of fatty acids or mixtures of fatty acids and the absorption patterns of several classes of lipids and their effect on the absorption of palmitic acid under in vivo conditions. In spite of wide melting point differences, isomers of various monoglycerides or 18-carbon unsaturated fatty acids exhibited identical absorption and solubility patterns. A homologous series of saturated monoglycerides showed a maximum absorption value for the monoglycerides with fatty acids of 12 and 14 carbons. Absorption decreased with increasing chain lengths of the fatty acid in the monoglyceride. Conversely, the absorption of palmitic acid when fed with the various monoglycerides progressively increased to a maximum in the mixture containing monomyristin and then decreased when fed with monopalmitin or monostearin.

Ribosomal profiles were prepared from liver postmitochondrial supernatant preparations of 2- to 21-day old and 60-day-old rats. Rats fed or starved for 3 or 15 to 16 hours were compared. Relative ribosomal distribution, calculated from planimetric analysis of the hepatic ribosomal profiles, was found to be approximately constant at all ages when fed animals were compared. In contrast, starvation for 15 hours resulted in profound changes in ribosomal distribution, i.e., a relative accumulation of oligosomes as compared with polysomes. This change in ribosomal distribution was most extensive in animals younger than 2 weeks of age, 60-day-old rats showing no effect. Refeeding of 6-day-old starved rats with diets containing 10% protein resulted in a prompt decrease in the planimetric yield of monsomes and disomes. Similarly, dietary protein was shown to be required to prevent accumulation of these two species. It is suggested that it is the response of the ribosomal cycle to starvation that changes with age rather than the maximum capacity for protein synthesis.

Because dried whey contains approximately 70% lactose, it could be harmful if incorporated into the diet of animals with low tolerance for lactose. Three experiments were conducted to determine the effects of various levels of dried whey in the diet of growing pigs. In the first two experiments diets containing up to 40% dried whey were fed from weaning to approximately 5 months of age. With respect to rate of gain or feed efficiency, there were no significant differences among dietary treatment groups. In a third experiment pigs that had consumed a diet containing no lactose from 6 to 12 weeks of age performed normally when fed a diet containing 40% dried whey from 12 to 21 weeks of age. The results of the three experiments suggest that the growing pig can tolerate up to 30% lactose in the diet without any symptoms of lactose intolerance, and that continuous exposure to lactose in the diet is not necessary to maintain tolerance to this level of lactose.

Tryptophan-deficient and nondeficient synthetic amino acid test diets were prepared using D, L-amino acids. The diets were fed to three groups of rainbow trout (Salmo gairdneri) for 8 weeks. Experimental control fish fed well and grew from 1.3 to 2.5 g. Deficient fish fed poorly and did not gain weight. Scoliosis was observed in the deficient fish after 1 week of feeding. Daily transitory scoliosis was noted in some fish. Histological studies of trypthophan-deficient scoliotic fish revealed hyperemia, disorganization of myomere septa, and protrusions of the fibrous matrix sheath, which invests the notochord. Abnormal deposition of calcium was noted in the kidney and the bony plates surrounding the notochord and sheath. Fish with mechanically induced scoliosis had disorganization of myomere septa, but did not have protrusions of fibrous matrix sheath, nor did they have abnormal calcium deposition in bone or kidney. Scoliotic fish returned to normal within 1 week upon replacement of tryptophan in the ration.

Intestinal absorption of radioactive free and protein-bound dietary methionine (Met) and changes in plasma amino acids were observed after feeding Met-supplemented test meals. Plasma and gastrointestinal contents were collected from 15 minutes to 16 hours after feeding. Plasma amino acids were determined after ad libitum ingestion of diets containing free Met. Protein-bound Met in fresh egg white and free Met left the stomach at the same rate, but protein-bound Met in dried egg white and free Met were emptied from the stomach at different rates. Free Met was absorbed from the intestine more rapidly than protein-bound Met. Concentrations and molar ratios of various free amino acids in plasma changed briefly in response to Met-supplemented single test meals. Long-term changes were observed when Met-supplemented diets were fed ad libitum. Prolonged ingestion of supplemented diets may cause sustained alterations in the plasma amino acid pattern.

We investigated the effects of a high meat mixed Western diet and a nonmeat diet, representing the dietary pattern of high and low risk areas for colon cancer, respectively, on fecal microflora dn on bile acid and neutral sterol patterns in man. The total anaerobic microflora as well as the count of Bacteroides, Bifidobacterium, Peptococcus, and anaerobic Lactobacillus were significantly higher during the period of consumption of a high meat mixed Western diet comparted with the nonmeat-diet consumption period. The difference in total fecal bile acid excretion was not significant between the two dietary periods. Fecal excretion of microbially modified bile acids and neutral sterols was decreased when subjects eating a high meat diet transferred to a nonmeat diet. These results support the fact that diet plays a modifying role on the composition of intestinal microflora, bile acids, and neutral sterols.

Effects of feeding rats a high tyrosine-low protein diet on protein synthesis in liver, muscle, and brain were investigated both in vitro and in vivo. Tissue tyrosine concentrations of rats consuming the high tyrosine diet for 7 days were substantially elevated; this was accompanied by severe growth retardation. In the livers of rats fed the high tyrosine diet for 6 days, polysomal profiles showed a shift toward heavier ribosomal aggregates, while in muscle and brain, extensive disaggregation of polysomes occurred. In an in vitro amino acid incorporating system, the activities of both the microsomal and pH 5 enzyme fractions isolated from the livers of the high tyrosine animals that had been fed the diet for 6 weeks were elevated. On the other hand, the capacity of muscle or brain ribosomal preparations to incorporate [14-C] leucine was much reduced. Similar results were obtained in a study of [14-C] leucine incorporation in vivo in which rats were force-fed two meals and killed at various times after the last feeding. In rats fed the high tyrosine diet, incorporation of leucine into liver increased progressively; this was accompanied by a gradual decrease in leucine incorporation into muscle. In contrast, leucine incorporation into brain was immediately suppressed. In view of the apparently paradoxical effect of a high tyrosine load on protein synthesis in the liver, rates of the anabolic and catabolic phases of protein turnover in animals fed a high tyrosine diet were determined from radioactivity measurements made after pulse labeling them with [14-C] bicarbonate. Results indicated that the rates of both synthesis and degradation of liver proteins were elevated over control values. Differences in the effects of a toxic load of tyrosine on protein synthesis in the tissues examined could be the consequence of altered metabolic or hormonal balance as a result of nutritional stress.

The rates of intestinal transport of dietary monosaccharides and disaccharides were determined in Wistar rats and the carbohydrate-sensitive BHE rats fed either a stock diet or a 65% sucrose diet. Sucrose-fed rats of both strains generally showed large and significant increases in the rates of glucose, alpha-methylglucose, fructose, and sucrose transport. The transport of galactose, maltose, and lactose did not show consistent increases due to sucrose feeding. Although the magnitude of the increases in sugar transport due to sucrose feeding was only slightly greater in BHE rats than in Wistar rats, BHE rats tended to exhibit a greater rate of sugar trnasport when fed both strains and in the BHE rats fed the stock diet. Lipogenic enzyme activity was greatly increased as a result of sucrose feeding; however, BHE rats did not show greater levels of enzyme activity than did Wistar rats. Liver lipids were increased in both the Wistar and the BHE sucrose-fed rats and in BHE rats fed either diet.

Present protein allowances are based on amounts of nitrogen (N) that maintain balance in adults in laboratory tests. In most tests of minimum N need, energy intakes were higher than present allowances and generally the participants maintained body weight or gained. To evaluate the relative importance of energy and protein intakes in the near-adequate range on the N equilibrium, healthy men were given two levels of protein with energy constant and three levels of energy with protein constant. In the first two 12-day periods, diets provided 5 and 7% of energy (E) from egg white protein with enough E to maintain weight essentially constant (39.6 plus or minus 4.4 kcal/kg). N balance data with these diets were used to select an individual protein intake level nearest to need (5, 6, or 7%), and that level was fed for the next three periods with the same E intake as before (100 E) and 85 or 115% of it. Crude N balance (dietary-fecal-urinary N) was minus0.26 g/day with 5% diet and 0.33 g/day with 7%. Balance was improved by 280 mg/g N fed between these levels. Predicted minimum N need to maintain crude N balance at 100 E is 89 plus or minus 18 mg/kg body weight or 3.76 plus or minus 0.61 mg/basal kcal. N balance fell to minus0.61 g/day with 85 E and increased to 0.59 g/day with 115 E. N balance changed by 174 mg/100 kcal between 85 and 100 E and 112 mg/100 kcal between 100 and 115 E. Energy intake appears to have a much greater effect on N balance than does protein intake in the marginally adequate ranges of intake.