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The terminal nucleotides of 70 S RNA extracted from murine leukemia virus (AKR, L-1 strain MLV) have been characterized by the introduction at the 5′-terminus of 32 P and by chemical conversion of the 3-terminal sugar residue to a tri[ 3 H]alcohol. Identification of the 32 P- and 3 H-labeled products after alkaline digestion of the RNA established uridine and adenosine as the 3′- and 5′-terminal nucleosides, respectively.

The reduction of 3 H-androstanolone into 3β-androstanediol was used to study the 3β-hydroxysteroid oxidoreductase activity of rat ventral prostate. This activity is present only in the cytosol and has a pH optimum of 8.5 with NADH as cofactor. The 3β-hydroxysteroid oxidoreductase activity , as compared to 3α-hydroxysteroid oxidoreductase activity, is much lower in the present study than was observed previously during prostate perfusion in vivo or prostate organ culture superfusion.

The Citrobacter ribonuclease, an enzyme that cleaves preferentially phosphodiester bonds of ribonucleic acid at uridylic acid residues, has been shown to bind the polyamines, putrescine, spermidine, and spermine. The binding of spermidine insures the maintenance of enzyme activity in the presence of the polynucleotide, polyguanylic acid, at a concentration which is ordinarily completely inhibitory. Enzyme activity, if inhibited by polyguanylic acid, could, however, be restored by spermidine, which appears to effect a removal of the polynucleotide from the enzyme surface. The substitution of the polyamine for the polynucleotide was used to obtain two spermidine-bound peptides from tryptic digests of a polyguanylic acid-enzyme complex. Amino acid analysis of the isolated peptides showed that one consisted of a chain having a minimum length of 17 residues but composed of 10 different amino acids. The other had a minimum length of 8 residues and contained only 6 different amino acids. In both cases, the ratio of peptide to polyamine was approximately 1 to 1.

A Green-function decoupling method for spin 1/2, similar to that used by Tyablikov and Bogoliubov for infinite samples, is developed in the thin-film case. To describe the 'surface condition' the exchange integrals are allowed to vary near the surface, and in the Heisenberg hamiltonian a new term, the surface anisotropy coupling ( Sigma f,gIf,gSz fSz g) is included. The spin-wave spectrum and the localized magnetization are studied over a wide range of temperature (from 0K to T(s) c, the sample Curie temperature). The pinning effect and the appearance of surface spin waves are connected to the 'surface condition' by means of a complex phase shift characteristic of the waves. The non-uniformity of the magnetization distribution at finite temperature is demonstrated to occur and to depend on the surface condition at 0K.

Elimination of CH3OH from the molecular ions of the methyl esters of cyclobut-3-ene-1, 2-dicarboxylic acids under electron-impact occurs to a much greater extent in stereoisomers having a trans configuration than in the cis analogues. Deuterium labelling shows that this process takes place via different mechanisms in the stereoisomeric esters. The abundance ratio [M CH3OH]˙+/[M CH3O]+ is suggested as the most sensitive criterion for the deduction of configuration in this system. Determination of the geometry of the cyclobutene esters by n.m.r. spectroscopy as well as by pyrolysis to corresponding isomeric muconates is also discussed.

A heat-stable ribonuclease isolated from the organism Enterobacter sp. has been purified to homogeneity as evidenced by polyacrylamide gel electrophoresis, sucrose density centrifugation and Sephadex gel filtration. Comparison of the properties of the homogeneous enzyme with those of the ribonuclease partially purified from Enterobacter by another method indicates that the two enzymes are the same. Analysis of the hydrolytic products found after enzymatic degradation of synthetic ribonucleotide polymers and of yeast RNA suggests that those fragments terminating in 3′-adenylic acid as well as those terminating in 3′-cytidylic acid result from the activity of the same enzyme.

start to get choosy../' Private four-year colleges and universities across the nation currently face an urgent problem that grows larger and more complex with each passing semester: what can be done to fill the increasing number of student vacancies at many underendowed private institutions of higher learning? The search for warm bodies is on "with the ardor of a Don Juan and the cautious precision of a watchmaker," as one newspaper recently put it. In an effort to pull high school graduates into a college career or woo them away from inexpensive and convenient public institutions, desperate private institutions are turning increasingly to the hard-sell approach to recruitment. Some have called in management consulting firms and professional recruiters to bolster or replace conventional admissions departments. A look at the Sunday issue of The New York Times shows multiple advertising, worth hundreds of dollars at a throw, where colleges now advertise their wares. A new kind of consultant who supposedly guarantees client colleges an increase in warm bodies has sprung up in the last year or two. Some have even persuaded such clients to offer discounted tuitions or, in one case, a "free" trip to the Holy Land as a bonus for enrollment.

The fasting adrenalectomized rat moved more fat out of the epididymal fat depot during a 12-hour fast than did the normal animal. Restoration of cortical hormone (hydrocortisone) at both high and low dose levels elicited a marked inhibition of fat movement out of this depot. The administration of hydrocortisone to intact animals also produced this inhibition. The procedure of sham adrenalectomy caused a significant diminution of fat mobilization from the epididymal depot for at least six days following the laparotomy. This response to trauma has now been observed in another laboratory following a burn stress. There are probably factors other than the release of cortical steroids which mediate this response but an increase in steroid titer appears to alter fat mobilization in this direction. The hypophysectomized animal behaves differently from the adrenalectomized animal in this regard. The amount of fat moved out of the epididymal depot by the hypophysectomized animal during a 12-hour fast was much small...

SummaryIt is suggested that a convenient way of presenting the results of fatigue tests in which two different stress amplitudes are applied alternately is to plot log N against log (n1/n) where N is the total cycles to failure and (n1/n) is the fraction of cycles run at the high stress.With these co-ordinates, a simple geometrical construction gives a safe design method for the two-stress level system using only the conventionalS-Ncurve and the value of (n1/n) expected to be encountered in service. IfN1andN2are the lives at the high and low stresses as read from theS-Ncurve, one point may be plotted at (log N1, 0) since this represents the programme when all cycles are at the high stress. On the assumption, shown to be justified, that less than one cycle of high stress per 10,000 total cycles would not significantly affect the life at the low stress, a second point is plotted at (log N2, 4). The straight line joining these two points is always found to predict safe values of N for any value of (n1/n).This conclusion is checked against a wide range of experimental results taken from six different sources in the literature covering rotating-bending and push-pull tests, ferrous and non-ferrous metals, any order of stressing and length of programme cycle from 50 up to 5 million. This last feature means that the length of the programme cycle in service need not be known. All that is required is the proportion in which the two stress amplitudes are mixed. The average value of the ratio (experimental life/predicted life) for the data examined is 1·8, the extreme values being 1 and 56. By plotting in three dimensions an equation is also developed for the three-stress level spectrum and a suggestion is made for an extension of the method to multiple stress levels.

In Heisenberg ferromagnetic thin films with {100} surfaces, the spin waves are analyzed in an exact treatment. The bulk and surface modes are separated and discussed. When the number N of parallel layers is finite, space quantization and phase shifts due to the surface perturbation are precised. Magnon specific heat, ferromagnetic resonance and the contribution to the fluctuation of the surface magnetization from the bulk and surface modes are studied in a microscopical way for very thin films. Anomalous variations of specific heat at very low temperature are found to exist. The ferromagnetic resonance is demonstrated to give a detailed study of the surface perturbation. Bulk and surface contributions occur in catalytic effects such as ortho-para conversion.

Structural alterations of the nucleoli of rat liver cells were noted when these nuclei were isolated with spermidine or spermine rather than magnesium. When 5–10 mM spermidine or spermine were used to isolate the nuclei, the nucleoli were a) larger, b) contained numerous and sometimes large lacunae, and c) were less aggregated and had prominent chromatin caps. These chromatin caps gave the nucleolus a ring-shaped appearance in the light microscope. These findings, coupled with physiological data that indicate that polyamines enhance nucleolar RNA polymerase activity (Russell et al., 1971), suggest that spermidine and spermine may be involved in the control of ribosomal RNA synthesis. To our knowledge, this is the first instance of the direct stimulation of ribosomal RNA synthesis during nuclear isolation.

This is a report of word usage in radiological (x-ray) patient records as found in a 5% sample of the annual case load at UAMC including 100,000 words. Records were taken exactly as dictated. The study is part of an effort to develop an IR system for patient data. The system “autocodes” (automatically stores) the physician's dictated findings and diagnoses in such a fashion that they can be retrieved again automatically. Some of our findings approximate results reported in the literature. For example, the rate of introduction of new different words levels off to about 2,500 words when 40,000 to 50,000 words of text have been analyzed. However, unclassified words continue to occur at a significant level of almost 2% at the 100,000 word level, with a 1% noise level. Attempts to establish the rank order of words beyond the first several hundred have failed because about 70% of the words appear to occur with such a low relative frequency (no more than one time in 10,000). Thus, establishing files by rank order appears impractical, even though filter lists (discard words) by rank groups (words with nearly the same relative frequency) are quite practical. Additional data are presented and design implications are discussed.

Earth satell ites, particularly those at the lower alt i tudes, are subject to external forces that , in general, undergo cont inuous changes because of the asphericity of Earth's shape. These variations induce secular and periodic changes in the parameters of the satellite's orbit which, under certain c ircumstances , may be undesirable. Therefore, the performance requirements necessary to counteract the effect of Earth's oblateness should be est imated in order to properly design t h e satell ite system. The following analysis presents requirements based on the present best e s t imate of Earth's potential . These requirements are given in terms of integral equations that , because of their nature, can only be evaluated by digital techniques . A simplified closed form solution is o b tained assuming constant mass (per revolution) and orbit circularity. Performance es t imates based on this type of solution can be used as rules of t h u m b for preliminary design purposes.

By dehydratation of the hexahydroxyplombates CdPb(OH) 6 and CaPb(OH) 6 , two new lead double oxides with oxydation state 4+ are synthetised: CdPbO 3 and CaPbO 3 . These compounds crystallize with an ilmenite type trigonal symmetry.

An expression is developed for the deflection of a straight beam subjected to unsymmetrical bending which eliminates the necessity of first finding the principal axes and principal moments of inertia of the section. Since it is already possible to calculate the position of the neutral axis and also the stress distribution without referring to principal axes, the present work offers one method of completing such a solution for the class of problems where deflections besides stresses are required.

The enrichment culture technique has been used to isolate bacteria which contain enzymes for the hydrolysis of the terminal amino acid in various folate analogues. Each of the three purified enzymes is specific for the hydrolysis of only one of the following compounds : 4-amino-4-deoxypteroylalanine, 4-amino-4-deoxypteroyl-aspartate and 4-amino-4-deoxypteroylglutamate. The hydrolysis in each reaction is in accord with the equation: 4-amino-4-deoxypteroyl-N-(amino acid) + H2O → 4-amino-4-deoxypteroate + amino acid.

The use of a tapered form of specimen for creep testingi s described. Strains are measured on a series of short gauge lengths, enabling a family of isothermal creep curves at different stresses to be obtained from a single test. The measurement of strain is by the replica method, but other methods are not necessarily excluded. Testing of tapered specimens makes possible a considerable saving in the aggregate time and material necessary to establish a set of creep curves, with little sacrifice of accuracy. Data are presented for the aluminium alloy DTD 5070A, and results from tapered specimens compare favourably with creep curves obtained in conventional tests.

A partially purified extract from a soil pseudomonad catalyzes the reaction 4-amino-4-deoxypteroylaspartate + H2O → 4-amino-4-deoxypteroate + aspartate This activity is dependent on the presence of Co++ or Zn++ and can be resolved into two components by disc gel electrophoresis. The possible interrelationships between the two enzymes has not been clarified, but both enzymes exhibit absolute specificity for linkages of the form RCO—N—, in which nitrogen is contributed by l-aspartate. In these substrates RCOOH represents not only a pteroyl group but also a variety of acyl groups and all the amino acids tested. This absolute specificity for aspartate in the carboxyl-terminal position of peptides complements previous studies on carboxypeptidase G, in which an analogous specificity is exhibited for glutamate.

THE IMPORTANT ROLE OF THE LIVER in carbohydrate metabolism, first demonstrated by Claude Bernard, has been reviewed recently by one of us (1). It is generally recognized that the glycogen stores of this organ have an important bearing upon its functional integrity and upon its resistance to damaging agents, and wide use has been made of high carbohydrate therapy in liver disease (2). Recent work has clearly shown that the liver is a major factor in the maintenance of the normal blood sugar level. Diabetes mellitus may be regarded as a disturbance in this homeostatic regulation because of a relative lack of insulin or a relative excess of the opposing endocrine factors. The endocrine balance controls the level at which the liver regulates the blood sugar. Under these circumstances it is readily understandable that liver disease which interferes with the responsiveness of this organ to endocrine influences alters carbohydrate tolerance in the non-diabetic organism and decreases the effectiveness of administ...

A method is described whereby Heinz bodies in erythrocytes may be demonstrated in histologic sections of formalin-fixed tissue. It consists of applying Natt's stain to 4 μ sections cut on a cryostat. The Heinz bodies appear with a clarity comparable to that seen in blood films.

The optical study of turbostratic carbons was undertaken after having succeeded in making transparent carbon films of different thicknesses. The fundamental optical spectra ϵ 1 and σ have been plotted as a function of the energy hω of the incident photons in the infrared range. The X-ray study has shown that the sublimation of graphite in vacuum leads to a real ‘degraphitization’ if the vapour is collected on a cold surface; such films have optical properties quite different when compared with graphite. This type of carbon can be compared to a semiconductor with a gap of 0·2 eV but it contains some permanent free carriers. When these films are heated in vacuum up to 900°C, their structure changes into an oriented model of turbostratic carbon (1000°C). Their electronic properties can be compared with those of graphite: the optical conductivity σ comes close to that of graphite while ϵ 1 takes lower (and always negative) values than before the heat treatment. This fact shows that the free carriers are more numerous than in graphite, because of the presence of a great number of defects which act as electron traps. These results agree fairly well with the schema proposed by Mrozowski for graphitizable carbons.

Elevated polyamine concentrations in human urine and serum appear to be associated with the presence of many types of cancer. The automated amino acid analyzer lends itself to the rapid separation and measurement of these substances with little sample handling and excellent reproducibility. The ion-exchange resin used was Beckman’s PA-35 (strong sulfonic acid cation exchanger, copolymerization product of styrene-divinylbenzene). Amino acids are bound less strongly to the resin than are the polyamines, and can be removed by first eluting with a buffer of lower ionic strength. If sample injections are overlapped, one sample can be analyzed every hour. We have corroborated that increased concentrations of polyamines appear in the urine of patients with a variety of cancers. Additionally, we have shown increased amounts of polyamines in the serum of patients having a diagnosis of cancer.

Purified Klebsiella ribonuclease (ribonucleate nucleotido-2′-transferase (cyclizing), EC 2.7.7.17) is able to hydrolyze poly(A), poly(U) and poly(C) more readily than yeast RNA, but cannot attack poly(G), poly(I), poly(X), poly(hU), poly(A) · poly(U) and poly(I) · poly(C). Hydrolysis of yeast RNA, poly(U), and poly(A) by this nuclease is inhibited markedly by poly(G) and to a much lesser extent by poly(I). Another compound, poly(X), is more potent than poly(I) as an inhibitor of RNA hydrolysis but less potent in inhibiting poly(U) hydrolysis. Relatively high concentrations of poly(hU) will inhibit poly(U) hydrolysis but have no effect when yeast RNA is the substrate. A number of mononucleotides were tested and have no effect on RNA hydrolysis by Klebsiella nuclease. Several other nucleases were found to be inhibited to a greater or lesser extent by poly(G) and poly(I). The data suggest that the nuclease prefers molecules of unordered secondary structure as substrates, and that ordered molecules are not attacked and may actually be inhibitors.

Melilotate hydroxylase partially purified from extracts of Arthrobacter species catalyzes the stoichiometric conversion of melilotic acid to 2,3-dihydroxyphenylpropionic acid. The hydroxylation is shown to require both reduced nicotinamide adenine dinucleotide and atmospheric oxygen. A partial resolution of the enzyme is achieved with ammonium sulfate. The preparation so treated is almost deviod of enzyme activity, but activity can be completely restored with flavin adenine dinucleotide. The role of melilotate hydroxylase in the general metabolism of coumarin is discussed.

Hemophilia-like disease may be defined as a hemorrhagic diathesis characterized by a prolonged clotting time and the presence of a circulating anticoagulant. Clinical data, such as occurrence in females or onset late in life in males, are of great value in establishing the diagnosis. It is to be distinguished from hemophilia complicated by the development of an anticoagulant following blood transfusions. Differentiation of these disorders is of practical significance because hemophilia-like disease is not hereditary and the clotting anomaly may disappear spontaneously. 2. Two cases with circulating anticoagulants are reported. In the first patient with hemophilia-like disease the anticoagulant was dialyzable and present for a limited period of time only. In the second patient, a 4 year old boy, the distinction between hemophilia-like disease due to an anticoagulant and pre-existing hemophilia with a complicating anticoagulant could not be made. 3. Analysis of the mode of action of the anticoagulants in these 2 cases showed interference with the formation of thromboplastin, although some antithromboplastic activity could not be excluded. 4. A simple technic for testing for circulating anticoagulants is described. It is recommended that this test be performed routinely in all patients with a bleeding tendency and a prolonged clotting time. ACKNOWLEDGMENTS We are indebted to Dr. Raphael Isaacs for permission to study his private patient. We gratefully acknowledge the assistance of Miss Helen MacLean from the Department of Bacteriology in performing the precipitin tests.

A 13 C Fourier transform (FT) NMR study of trimethyl(phenylethynyl)silane gives new evidence for ( p → d ) π bonding or equivalent interaction between bonded carbon and silicon atoms. Pulsed FT operation allows detection of 29 Si 13 C spinspin coupling observed as 2.3 % 29 Si satellites in 13 C spectra. The one-bond 13 C 29 Si coupling constants for seven compounds were found to be roughly proportional to “ s ” character on carbon, ranging from 50.2 ( sp 3 ) to 83.6 Hz ( sp ).

A pseudomonad has been isolated from soil which can utilize glutamate derived from the hydrolysis of folate or methotrexate (4-amino-N10-methylpteroylglutamic acid) as a source of carbon and nitrogen. During growth of the organism on folate, large quantities of pteroic acid accumulate in the growth medium. The enzyme responsible for the deamidation has been partially purified. It has a pH optimum of 7.3 and a Km toward methotrexate of 2.4 x 10-4 m. The reactivity of the enzyme toward a number of folate analogues has been studied.