Showing papers by "New York University published in 1970"
TL;DR: A population of lymphoid cells from several animal species, including man, was identified through a membrane receptor which binds sheep red blood cells treated with antibody and complement, and these cells could be distinguished by their different abilities to bind EAC, CRL and non-CRL from mouse lymphoid organs.
Abstract: A population of lymphoid cells from several animal species, including man, was identified through a membrane receptor which binds sheep red blood cells treated with antibody and complement. When cells from different lymphoid organs were incubated with EAC at 37°C, only part of the lymphocytes (named CRL) bound EAC and formed rosettes, and this interaction was shown to be C3-dependent. Mouse lymphoid cells could be specifically depleted of CRL by allowing them first to interact with EAC and then submitting the mixture to ultracentrifugation in a gradient of BSA. After ultracentrifugation, a population of cells containing 95% or more of non-CRL were recovered from the upper layers of the gradient. In addition to their different abilities to bind EAC, CRL and non-CRL from mouse lymphoid organs could be distinguished by the following properties: (a) CRL adhered preferentially to nylon wool at 37°C in the presence of mouse serum. (b) After differential flotation in a gradient of BSA, a significantly higher proportion of CRL were recovered from the upper layers of the gradient. (c) The population of CRL contained most of the lymphocytes bearing immunoglobulin determinants on their membranes. (d) The distribution of CRL was quite different among lymphocytes obtained from various lymphoid organs, and they were never found in the thymus. (e) The membrane receptor for EAC was not detected in plaque-forming cells of mice which had been previously immunized with burro red cells. CRL and non-CRL could not be distinguished by their life span, as they were found in similar proportions among long-lived and short-lived lymphocytes from mouse peripheral lymph nodes. The function of this receptor on the membrane of certain lymphoid cells may be related to (a) the trapping and localization of antigen in lymphoid organs or (b) the localization of lymphoid cells in inflammatory sites.
1,029 citations
TL;DR: The circular dichroism (CD) spectra of the four usual deoxymononucleosides, all sixteen deoxydinucleotides, and a number of trinucleotide diphosphates have been measured as mentioned in this paper.
Abstract: The circular dichroism (CD) spectra of the four usual deoxymononucleosides, all sixteen deoxydinucleotides, and a number of trinucleotides have been measured. The dimer spectra are quite different from the sum of the spectra of their constituent monomers. This indicates the presence of base-stacked conformations analogous to those found for ribonucleoside diphosphates. The CD spectra of several deoxytrinucleotide diphosphates and single-strand f 1 DNA can be calculated fairly well by using a semi-empirical nearest-neighbor approach. There is little or no effect of terminal phosphate or of salt concentration on the optical properties of most deoxy oligomers. The possibility of simultaneous analysis of mixtures of deoxypurine or deoxypyrimidine sequence isomers has been examined. This seems to be a viable approach for the analysis of purine runs but cannot promise much success for pyrimidine runs.
787 citations
630 citations
TL;DR: Habituation and dishabituation were not due to peripheral changes in either the sensory receptors or the gill musculature butt but were caused by changes in the amplitlude of the excitatory synaptic potentials produced at the gills motor neurons.
Abstract: We have examinived the nieural correlates of habittuatiotn atid dishabitiuation of tlhe gill-withdrwal reflex in Aplysia. We obtained intracelllular recordings from identified gill motor neurons in the abdominal ganglionz of a semi-intact preparation of Aplysia wlhile we simultaneously recorded behavior responises of the gill. Habituation and dishabituation were not due to peripheral changes in either the sensory receptors or the gill musculature butt were caused by changes in the amplitlude of the excitatory synaptic potentials produced at the gill motor neurons.
595 citations
TL;DR: A behavioral reflex mediated by identified motor neurons in the abdominal ganglion of Aplysia undergoes two simple forms of shortterm modification.
Abstract: A behavioral reflex mediated by identified motor neurons in the abdominal ganglion of Aplysia undergoes two simple forms of shortterm modification. When the gill-with-drawal reflex was repeatedly evoked by a tactile stimulus to the siphon or mantle shelf, the amplitude of the response showed marked decrement (habituation). After a period of rest the response showed spontaneous recovery. The amplitude of a habituated response was facilitated by the presentation of a strong tactile stimulus to another part of the animal (dishabituation). Many characteristics of habituation and dishabituation in Aplysia are similar to those in vertebrates.
415 citations
TL;DR: An investigation of the scattering of gravitational waves by a Schwarzschild horizon finds some results obtained from a theoretically all possible modes in which the presence of a black-hole manifests itself.
Abstract: THE discovery of pulsars and the general conviction that they are neutron stars resulting from gravitational collapse have strengthened the belief in the possible presence of Schwarzschild black-holes—or Schwarzschild horizons—in nature, the latter being the ultimate stage in the progressive spherical collapse of a massive star. The stability of these objects, which has been discussed in a recent report1, ensures their continued existence after formation. Inasmuch as the infinite redshift associated with it and its behaviour as a one-way membrane make the Schwarzschild horizon at once elusive and intriguing, it is important to explore theoretically all possible modes in which the presence of such a black-hole manifests itself. In what follows, we present a partial summary of some results obtained from an investigation of the scattering of gravitational waves by a Schwarzschild horizon.
406 citations
TL;DR: Procedures for in vitro immunochemical study of release of histamine from leukocytes of peripheral blood are described and the convenience, reliability, and usefulness have been demonstrated.
321 citations
TL;DR: Three synthetic inhibitors of proteases inhibit the tumorigenesis initiated in mouse skin by 7,12-dimethylbenz(a)anthracene and promoted by croton oil or its active principle, phorbol ester.
Abstract: Three synthetic inhibitors of proteases (tosyl lysine chloromethyl ketone, tosyl phenylalanine chloromethyl ketone, and tosyl arginine methyl ester) inhibit the tumorigenesis initiated in mouse skin by 7,12-dimethylbenz(a)anthracene and promoted by croton oil or its active principle, phorbol ester. These protease inhibitors, when applied directly to mouse skin, inhibit some of the irritant effects of the tumor promoter and are not toxic.
266 citations
TL;DR: In this article, a double sampling scheme is presented to estimate the proportion of units which belong to one of two mutually exclusive categories, and the maximum likelihood estimate of p is derived along with its asymptotic variance.
Abstract: Two measuring devices are available to classify units into one of two mutually exclusive categories. The first device is an expensive procedure which classifies units correctly; the second device is a cheaper procedure which tends to misclassify units. To estimate p, the proportion of units which belong to one of the categories, a double sampling scheme is presented. At the first stage, a sample of N units is taken and the fallible classifications are obtained; at the second stage a subsample of n units is drawn from the main sample and the true classifications are obtained. The maximum likelihood estimate of p is derived along with its asymptotic variance. Optimum values of n and N which minimize the measurement costs for a fixed variance of estimation and which minimize the precision for fixed cost are derived. This double sampling scheme is compared to the binomial sampling scheme in which only true measurements are obtained.
242 citations
TL;DR: In this paper, the magnitude of the expected superfluid transition temperature and the form of the gap are obtained for regimes of neutron density expected in neutron-star cores, and the gap is anisotropic but nodeless.
Abstract: The magnitude of the expected superfluid transition temperature and the form of the gap are obtained for regimes of neutron density expected in neutron-star cores. For neutron densities exceeding 1.5\ifmmode\times\else\texttimes\fi{}${10}^{14}$ g ${\mathrm{cm}}^{\ensuremath{-}3}$ the gap is anisotropic but nodeless, leading to thermodynamic properties of a conventional BCS-type superfluid.
209 citations
TL;DR: To define a model for enzyme latency in vitro, the capture was studied of egg white lysozyme by liposomes (phospholipid spherules in the smectic mesophase) and it was considered likely that the liposome had captured lyso enzyme in the interspaces between lipid lamellae.
TL;DR: Administration of zoster immune globulin appeared to be an effective method to modify varicella in immunocompromised patients.
Abstract: The prophylactic efficacy of zoster immune globulin was evaluated in 21 immunocompromised children (under therapy for leukemia or other malignant processes) who had household exposures to varicella. In six of the children who had serum antibody to antigen on the membrane of cells infected with Varicella Zoster virus, evidence of varicella did not develop. The remaining 15 children who did not have detectable Varicella Zoster antibody became infected. Varicella was severe in one, mild in nine and subclinical in five children. All 15 children, had persistence of Varicella Zoster antibody for months to years after infection. Administration of zoster immune globulin appeared to be an effective method to modify varicella in immunocompromised patients. (N Engl J Med 290:243–245, 1974)
TL;DR: A model of increasing complexity has been derived for the macromolecular organization of cartilage ground substance and suggests that both PPL3 and PGS may exist as mixtures of monomers and dimers formed by the end to end association of monomer.
TL;DR: A descriptive model of the variables and interrelationships in the conflict process is presented and suggests both a testable framework for researchers and a meaningful perspective for management.
Abstract: Little is known about the causes, measurement, management, and consequences of conflict in distribution and its effect on distribution channel performance. This article presents a descriptive model...
TL;DR: Rabbits were immunization to two antigens and 18–55 days later exchange transfusion was performed using blood of rabbits immunized to one antigen only, suggesting that a change in the rate of antibody formation had occurred, although other changes in the quality of serum antibody were not excluded.
Abstract: Rabbits were immunized to two antigens and 18–55 days later exchange transfusion was performed using blood of rabbits immunized to one antigen only By this means, serum antibody levels to one antigen were reduced 50–84% while maintaining serum antibody levels to the second antigen After exchange, serum antibody levels of the removed antibody rose rapidly for 24–48 hr and then more slowly, reaching peak titers an average of 8 days later The peak titer was 48–222% higher than the preexchange titer The specificity of this rebound excluded as a cause nonspecific changes in Ig levels Passive administration of antibody to a third antigen 4–7 days before the exchange indicated that re-equilibration of preformed antibody was not a major factor in the rebound A change in the ratio of IgM to IgG antibodies as a cause of an increased neutralization titer in the postexchange sera was also excluded It was therefore suggested that a change in the rate of antibody formation had occurred, although other changes in the quality of serum antibody were not excluded
TL;DR: A partial survey of the literature of comparative management reveals that there are four major types of explanation of managerial similarities and differences: cultural, economic, psychological, and economic as discussed by the authors...
Abstract: A partial survey of the literature of comparative management reveals that there are four major types of explanation of managerial similarities and differences: cultural, economic, psychological, an
TL;DR: Although DF activity could entirely account for the role of F3 in the ribosome cycle this factor has an additional function in formation of the initiation complex that may be related to its RNA binding properties.
Abstract: Homogeneous preparations of initiation factor F3 have both RNA binding and ribosome dissociation activities. But although DF activity could entirely account for the role of F3 in the ribosome cycle this factor has an additional function in formation of the initiation complex that may be related to its RNA binding properties.
TL;DR: The circular dichroism spectra of all 16 ribodinudeoside phosphates containing the bases adenine, uracil, cytosine, and guanine have been measured at room temperature and neutral pH and suggest that the geometry of the base‐stacked conformation of ribo compounds must differ substantially from that of deoxy compounds.
Abstract: The circular dichroism spectra of all 16 ribodinudeoside phosphates containing the bases adenine, uracil, cytosine, and guanine have been measured at room temperature and neutral pH. These results are compared with the circular dichroism spectra of the corresponding deoxy compounds. From the optical properties it is clear that the geometry of the base-stacked conformation of ribo compounds must differ substantially from that of deoxy compounds. Because of this, it is not possible to draw firm conclusions about the relative extent of stacking in most ribo and deoxy compounds. The optical rotatory dispersion of about a dozen deoxy and ribodinucleoside phosphates has been studied as a function of temperature. These results confirmed the conclusions drawn earlier from measurements at a single temperature. Several dinucleoside phosphates containing a 2′ 5′ phosphodiester bond have also been examined. These compounds have a substantial degree of base stacking at room temperature. The geometry of the stacked conformation is different from that of either the normal ribo dimer or the deoxy dimer. The role of the 2′-hydroxyl group in stabilizing base stacked geometries has been examined by studies on C-2′-O-methyl-pC. This compound has optical properties almost identical to those of CpC. This suggests that the effect of the 2′ hydroxyl is felt indirectly through its perturbation of the geometry of the sugar ring rather than directly by hydrogen bonding. It is not possible at present to identify precise conformational differences among deoxy-, ribo-and 2′ 5′ ribodinucleoside phosphates.
TL;DR: Speed of exercise was found to be specific for muscular endurance and for force increases at and below the exercise speed.
Abstract: Resistive exercise is employed to increase functional performance. Weight lifting has been the traditional program of resistive exercise to increase muscular force (strength). Ten years ago Hellebrandt found that the amount of work done is not as important as the rate at which it is done. The purpose of this study was to determine the specific effects on muscular endurance and on muscular force of two different training speeds. The two training programs administered to two different groups were slow maximal exercise (low power) and rapid maximal exercise (high power). Speed of exercise was found to be specific for muscular endurance and for force increases at and below the exercise speed.
TL;DR: Estimation of the probable number of fertilized ova among women wearing IUD's suggests that the device reduces uterine implantation, tubal implantation and the incidence of ovarian pregnancy, which could be explained by the production in the endometrium of an agent interfering with either fertilization or implantation.
TL;DR: In this paper, a compound gamma distribution has been derived by compounding a gamma distribution with another gamma distribution, which is reduced to the Beta distribution of the first kind and the second kind and to the F distribution by suitable transformations.
Abstract: In this paper a compound gamma distribution has been derived by compounding a gamma distribution with another gamma distribution. The resulting compound gamma distribution has been reduced to the Beta distributions of the first kind and the second kind and to theF distribution by suitable transformations. This includes theLomax distribution as a special case which enjoys a useful property. Moment estimators for two of its parameters are explicitly obtained, which tend to a bivariate normal distribution. The paper contains expressions for a bivariate probability density function, its conditional expectation, conditional variance and the product moment correlation coefficient. Finally, all the parameters of the compound gamma distribution are explicitly expressed in terms of the functions of the moments of the functions of random variables in two different ways.
TL;DR: A 67-year-old woman, a retired writer, was ad mitted to the hospital on March IS, 1968 and noted severe visual impairment in her left eye, pro gressing within a day to monocular blindness.
TL;DR: This study was designed to investigate whether speech therapy enhances language recovery in severe aphasia and whether or not the method of speech therapy used affects recovery if it occurs.
Abstract: This study was designed to investigate whether speech therapy enhances language recovery in severe aphasia and whether or not the method of speech therapy used affects recovery if it occurs. Thirty...
TL;DR: In this article, the frequency dependence of the operational amplifiers, which has been the principal limiting factor for high stable Q at higher frequencies for networks presented in the literature, has been taken into account.
Abstract: A new circuit realizing high stable Q 's is presented. The frequency dependence of the operational amplifiers, which has been the principal limiting factor for high Q at higher frequencies for networks presented in the literature, has been taken into account. The performance of the new network is shown to be superior to the realizations thus far presented in the literature for the following reasons. The Q realized by the new circuit is independent of the operational-amplifier bandwidth, which results in a stable response. The realization is also insensitive to manufacturing tolerances and, therefore, it can be readily tuned for the desired Q and center frequency without encountering any stability problems.
TL;DR: Immunization of inbred strains of mice with repeated minute doses of hapten-protein conjugates demonstrated wide differences in the magnitude of their antibody responses, which were related to the histocompatibility (H-2) type of the strains.
Abstract: Immunization of inbred strains of mice with repeated minute doses (0.1 to 1.0 microgram) of hapten-protein conjugates demonstrated wide differences in the magnitude of their antibody responses, which were related to the histocompatibility (H-2) type of the strains. Immunization with a single high dose (100 micrograms) of antigen failed to demonstrate these differences.
TL;DR: There may be a variable relationship between the tissue concentration and synthesis rates of the monoamines under both normal conditions and lithium treatment, and the observed differences in the action of lithium on monoamines in the regions studied may be related to the morphology of these discrete areas.
TL;DR: Data are presented which indicate that the activities of the glucagon and epinephrine responsive components of hepatic adenyl cyclase vary separately as a function of age, sex and steroid hormone levels in the rat.
Abstract: This study presents data which indicate that the activities of the glucagon and epinephrine responsive components of hepatic adenyl cyclase vary separately as a function of age, sex and steroid hormone levels in the rat. These observations lend support to the hypothesis that the 2 hormonally sensitive adenyl cyclase systems in liver are independent. (Endocrinology 86: 154, 1970)
TL;DR: Intrarenal pressure, estimated by measurement of wedged renal vein pressure, was elevated in patients with essential hypertension, indicating that the higher systemic pressure in essential hypertension is transmitted beyond the arterioles and accounts for elevation of intrarenal Pressure.
Abstract: 1. Intrarenal pressure, estimated by measurement of wedged renal vein pressure, was elevated in patients with essential hypertension. Despite increased afferent arteriolar resistance, glomerular pressure was elevated indicating that the higher systemic pressure in essential hypertension is transmitted beyond the arterioles and accounts for elevation of intrarenal pressure. 2. During hypertonic saline loading in hypertensives, renal arteriolar resistance falls, resulting in further increase in intrarenal pressure. Increments in intrarenal pressure paralleled increases in sodium excretion in patients with essential hypertension during the exaggerated natriuresis and in normotensive subjects after the prolonged infusion of hypertonic saline. 3. The marked increase in intrarenal pressure which appears to be responsible for exaggerated natriuresis in essential hypertension is attributable to an altered (exaggerated) response of the renal arterioles. The data suggest that elevated intrarenal pressure may play a role in the regulation of sodium balance in patients with essential hypertension.