bluuebunny/crossref_metadata_2025 huggingface dataset:
Bone Cells: Biochemical and Biological Studies after Enzymatic Isolation
Authors: Peck William A. , Birge Stanley J. , Fedak Susan A.
Published: October 2006

Short-term incubation of rat calvaria in buffered crude collagenase permitted the isolation of morphologically intact cells that absorb vital dyes, contain alkaline phosphatase, and multiply in tissue culture. Freshly harvested cells were similar to whole bone segments in aerobic glucose metabolism.
Foveal Receptors of the Monkey Retina: Fine Structure
Authors: Dowling John E.
Published: October 2006

The outer segments of the foveal cones of the rhesus monkey are about 40 microns long and 0.9 microns wide. They consist of stacks of membrane-limited, transverse discs about 140 Å thick, surrounded by a plasma membrane. The inner segments are about 30 microns long and 2.5 to 3 microns wide at the base, and they taper gradually to a tip diameter of about 1.5 microns. They contain many long mitochondria which are oriented lengthwise and are concentrated in the distal portion of the segment. The terminal pedicles show many synaptic contacts, probably as many as 36 per pedicle.
Botulinum Toxin, Type A: Effects on Central Nervous System
Authors: Polley E. H. , Vick J. A. , Ciuchta H. P. , Fischetti D. A. , Macchitelli F. J. , Montanarelli N.
Published: October 2006

This study has demonstrated that type A botulinum toxin has a depressant effect on the cortical electrical activity of anesthetized and unanesthetized monkeys. Simultaneous recordings of vital signs indicated a relative lack of change in the electrocardiogram, respiration, blood pressure, and heart rate during this time. The change in the electroencephalogram appeared cyclic in nature and independent of dose or time. All animals exhibited signs of respiratory failure characterized by a gradual interference with neuromuscular transmission at the diaphragm, and subsequently died an anoxic death.
Hereditary Angioneurotic Edema: Two Genetic Variants
Authors: Rosen Fred S. , Charache Patricia , Pensky Jack , Donaldson Virginia
Published: October 2006

Serums of patients with hereditary angioneurotic edema lack inhibitory activity against the esterase derived from the first component of complement. In one group of patients this lack appears to result from failure to synthesize the esterase inhibitor of the first component of complement, whereas in another group of patients an abnormal, nonfunctional protein is synthesized.
Quasi-Stellar Sources: Variation in the Radio Emission of 3C 273
Authors: Dent W. A.
Published: October 2006

Evidence is presented for the first time for large fractional variations in the radio emission of the quasi-stellar sources 3C 273, 3C 279, and 3C 345, all of which have flat radio spectra at centimeter wavelengths.
Oxidation of Dimethyl Sulfoxide to Dimethyl Sulfone in the Rabbit
Authors: Williams Kenneth I. H. , Whittemore Katherine S. , Mellin Theodore N. , Layne Donald S.
Published: October 2006

A white, crystalline compound was obtained from a butanol extract of the urine of rabbits injected subcutaneously with dimethyl sulfoxide. The melting point and infrared spectrum of the compound were identical with those of authentic dimethyl sulfone.
Pasteurella pestis
: Role of Pesticin I and Iron in Experimental Plague
Authors: Brubaker R. R. , Beesley E. D. , Surgalla M. J.
Published: October 2006

Loss of the genetic determinant for pesticin I in
Pasteurella pestis
results in concomitant loss of the plague coagulase and fibrinolytic factor. The median lethal dose for mice of an isolate lacking only these activities is increased by factors of about 10
1
, 10
4
, and 10
7
cells when administered by the intravenous, intraperitoneal, and subcutaneous routes, respectively. Virulence of the aforesaid strain can be enhanced in mice treated with 40 μg of ferrous iron. This response resembles that of
Pasteurella pseudotuberculosis
, a closely related species that normally lacks pesticin I.
Stridulation in Leaf-Cutting Ants
Authors: Markl Hubert
Published: October 2006

The leaf-cutting ant
Atta caphaloes
L. stridulates whenever it is prevented from moving freely. Although audible to the human ear, the airborne sound produced has its main energy concentrated between 20 and 60 kilocycles per second. However, it is not the airborne, but the ground-conducted stridulation sound that acts as a distress alarm: a stridulating ant attracts other workers, and if the "calling" ant is covered by earth, intensive digging is released in the attracted nest mates.
Hemolysin of
Mycoplasma pneumoniae
: Tentative Identification as a Peroxide
Authors: Somerson Norman L. , Walls Barbara E. , Chanock Robert M.
Published: October 2006

Mycoplasma pneumoniae
produces a soluble hemolysin active against guinea pig erythrocytes. This hemolysin appears to be a peroxide, since catalase or peroxidase inhibits its activity. The action of catalase and peroxidase is specific, since heating the enzymes abolishes their effect on the hemolysin. In addition, 3-amino-1,2,4-triazole, a potent inhibitor of catalase, reverses the inhibitory effect of the enzyme. The hemolysin of
M. laidlawii
is also a peroxide. The hemolysins of
M. pneumoniae
and
M. laidlawii
seem unique for microbial organisms since the bacterial hemolysins which have been described have been protein or lipid in nature.
Gamma-Globulin Factors (Gm and Inv) in New Guinea: Anthropological Significance
Authors: Giles Eugene , Ogan Eugene , Steinberg Arthur G.
Published: October 2006

Analysis of the hereditary Gm and Inv γ-globulin factors of 1669 New Guineans from the Morobe and Eastern Highlands districts and Bougainville Island demonstrates that the frequencies of the three Gm alleles present (
Gm
a
,
Gm
ab
, and
Gm
ax
) are similar in general to those in Mongoloids and in particular to those in Southeast Asians and Micronesians. The New Guinea frequencies are distinct from those in other populations, including Australian aborigines. Highly significant differences in frequencies of Gm and Inv alleles occur between Melanesian- and non-Austronesian-speaking New Guineans.
Biosynthesis of Histones and Acidic Nuclear Proteins under Different Conditions of Growth
Authors: Hnilica Lubomir S. , Kappler Harvey A. , Hnilica Violette Schlatter
Published: October 2006

The incorporation of uniformly labeled L-lysine-C
14
into the normal and regenerating rat liver, into Novikoff hepatoma histones, and into acidic nuclear proteins was studied. In rat liver, different histone fractions incorporate labeled lysine to a different extent. Such differences become less obvious in regenerating liver, and they are even less so in Novikoff hepatoma. In the hepatoma cells the ratio of the biosynthesized acidic nuclear proteins to histones was altered.
Lactate Dehydrogenase Isozymes: Substrate Inhibition in Various Human Tissues
Authors: Vesell Elliot S.
Published: October 2006

The total lactate dehydrogenase (LDH) in whole homogenates of various human tissues reacts more similarly toward pyruvate and lactate at 25°C than expected from the marked differences in substrate inhibition at this temperature between isolated, purified LDH-1, and LDH-5. At 37°C, LDH-5 closely resembles LDH-1 in extent of inhibition by substrate. These results are incompatible with the theory that differences in degree of isozyme inhibition by substrate have resulted in predominance of LDH-5 in anaerobic tissues and predominance of LDH-1 in aerobic tissues.
Rabbit: Frequency of Suckling in the Pup
Authors: Zarrow M. X. , Denenberg Victor H. , Anderson Clark O.
Published: October 2006

Rabbit does were given free access to their young, access once a day, and access twice a day. In all three groups the young were nursed only once every 24 hours. Growth curves for the pups from day 2 of age to day 30 were identical for all three groups. The restriction of suckling to once a day appears to depend on the mother and not the pups.
Patents on Random Complementary DNA Fragments?
Authors: Kiley Thomas D.
Published: October 2006

The proposal by the National Institutes of Health (NIH) to patent products resulting merely from sequencing the human genome is a mistake: at worst, it is wrong in patent law; at best, it relies on deficiencies in law concerning what is "useful" as a requirement for patents. The proposal is symptomatic of a problem besieging biotechnology—attempts to control the raw material of scientific experimentation before research has determined the practical value of such material—that needs curing on many fronts. Corrective measures are proposed for adoption by the Executive branch, the Congress, and the courts.
Control of Pain Motivation by Cognitive Dissonance
Authors: Zimbardo Philip G. , Cohen Arthur R. , Weisenberg Matisyohu , Dworkin Leonard , Firestone Ira
Published: October 2006

Responses by humans to painful electric shocks are significantly modified at subjective, behavioral, and physiological levels by verbal manipulations of degree of choice and justification for further exposure to the aversive stimuli. Pain perception, learning, and galvanic skin resistance are altered under these conditions of "cognitive dissonance," as they are by reductions in voltage intensity.
Major Components in the Exocrine Secretion of a Male Butterfly (
Lycorea
)
Authors: Meinwald J. , Meinwald Y. C. , Wheeler J. W. , Eisner T. , Brower L. P.
Published: October 2006

Extracts of the extrusible secretion-disseminating organs ("hairpencils") of the male of the danaid butterfly,
Lycorea ceres ceres
, from Trinidad, contain a pyrrolizidine and two aliphatic esters. An odorous component, present in trace amounts, remains unidentified. Judging from the function of "hairpencils" in a related species, the secretion may play a mediating role in courtship.
Organization of DNA in Dipteran Polytene Chromosomes as Indicated by Polarized Fluorescence Microscopy
Authors: MacInnes James W. , Uretz Robert B.
Published: October 2006

Analysis of the polarization of fluorescence from
Drosophila virilis
polytene chromosomes stained with acridine orange suggests that the DNA in the interband regions of these chromosomes cannot be in a supercoiled configuration, but must lie parallel to the chromosome axis.
Synaptic Activity in Motoneurons during Natural Stimulation of Muscle Spindles
Authors: Burke R. E. , Nelson P. G.
Published: October 2006

Synaptic activity evoked in cat motoneurons during stretch stimulation of muscle spindles in the homonymous muscle has been studied by intracellular recording. A class of miniature excitatory postsynaptic potentials evoked by such physiologic stimulation results from activity in single group la spindle afferent fibers, and the criterion for identification is a predictable pattern of rhythmic occurrence of the synaptic potentials. Statistical examination of the amplitude distributions of this class of miniature synaptic potentials suggests that some group Ia fibers liberate a relatively large number of quantal excitatory postsynaptic potential units per fiber impulse.
Hemoglobins M: Identification of Iwate, Boston, and Saskatoon Variants
Authors: Hayashi Akira , Shimizu Akira , Yamamura Yuichi , Watari Hiroshi
Published: October 2006

Hemoglobin M variants, M Iwate, M Boston, M Saskatoon are easily and accurately identified by electron spin resonance with small amounts of patients' blood. In hemoglobin M Iwate and M Boston the electron spin resonance of both fresh blood (unprocessed) and isolated pure ferrihemoglobin M revealed similar signal shapes; whereas that of hemoglobin M Saskatoon was doublet in fresh blood and triplet in pure ferrihemoglobin M.
Glucose-6-Phosphatase in Tubular Endoplasmic Reticulum of Hepatocytes
Authors: Rosen Sidney I. , Kelly George W. , Peters Virginia B.
Published: October 2006

The histochemical localization of glucose-6-phosphatase activity in neonatal mouse liver was studied under electron microscopy. The activity was demonstrated in the tubular endoplasmic reticulum, which pervades the glycogen areas of the cell during glycogenolysis. Activity was also demonstrated in the nuclear envelope and ergastoplasm.
Antigenic Differences in the Surfaces of Hyphae and Rhizoids in
Allomyces
Authors: Fultz Sara A. , Sussman Alfred S.
Published: October 2006

Immunofluorescent techniques have demonstrated a difference in surface components of hyphae and rhizoids of
Allomyces macrogynus
. An antigenic component detected on the rhizoidal surface may be present, but masked, in the hyphal-wall matrix material. The system also allows visualization of the hyphal wall during aging, when changes from a smooth to a fissured surface are noted, and differences in adsorptive properties occur.
Vitamin D
3
-Induced Calcium-Binding Protein in Chick Intestinal Mucosa
Authors: Wasserman R. H. , Taylor A. N.
Published: October 2006

The administration of vitamin D
3
to rachitic chicks induces in intestinal mucosal tissue the formation or elaboration of a calcium-binding factor which is found in the supernatant of the mucosal homogenate. The enhanced binding of Ca by the "vitamin D" supernatant (in contrast to "rachitic" supernatant) was indicated by a slower rate of diffusion of Ca
45
across a cellophane dialyzing membrane and by a lesser amount of Ca
45
being bound to an ion-exchange resin (Chelex-100) in the presence of vitamin D
3
supernatant. The binding activity was only associated with the protein fraction from a Sephadex G-25 column and was destroyed by trypsin digestion. This and other evidence suggest that the soluble factor is a protein. The vitamin D
3
-enhanced duodenal absorption of Ca
47
in rachitic chicks occurred almost simultaneously with the appearance of the vitamin D
3
-induced factor, and there was good correlation between the concentration of binding factor and the rate of absorption of Ca
47
.
Optomotor Responses by Echolocating Bats
Authors: Suthers Roderick A.
Published: October 2006

Optomotor responses to moving stripes have been elicited from nine species of Microchiroptera. The minimum separable visual angle of two phyllostomids, under the experimental conditions, probably lies between 3.0 and 0.7 degrees; that of
Myotis lucifugus
, between 6.0 and 3.0 degrees. Four species indicate an ability to resolve stripes subtending 0.7 degree, the narrowest tested.
Immunoglobulin Synthesis in vitro by Established Human Cell Lines
Authors: Fahey J. L. , Finegold I. , Rabson A. S. , Manaker R. A.
Published: October 2006

Several lines of human lymphoid cells derived from malignant lymphoma produce immunoglobulins in vitro. Immunoglobulins G(IgG, γG) are synthesized in two cell lines and immunoglobulin M (IgM, γM) in one.
Influenza Virus Purification with the Zonal Ultracentrifuge
Authors: Reimer Charles B. , Baker Robert S. , Newlin Thomas E. , Havens Milton L.
Published: October 2006

Sufficient amounts of influenza virus (density, 1.185; size, 722
S
) can be highly purified (22,000 chicken cell agglutinating units per milligram of protein) with a zonal ultracentrifuge, used first in a rate process followed by isopycnic banding, to permit its detailed biological and physical-chemical evaluation.
Staining Tissue for Light and Electron Microscopy by Bridging Metals with Multidentate Ligands
Authors: Hanker Jacob S. , Deb Chandicharan , Wasserkrug Hannah L. , Seligman Arnold M.
Published: October 2006

"Osmium black," a pigment very useful for cytological staining in both light and electron microscopy, may be deposited selectively at the tissue-binding sites of other metal ions by bridging OsO
4
to the tissue bound metal ion through a multidentate ligand.
Lysosomal Nature of Juxtaglomerular Granules
Authors: Fisher Edwin R.
Published: October 2006

Demonstration by a combined histochemical and electron-microscopic technique of the ultrastructure of and acid phosphatase within the juxtaglomerular granules in kidneys of normal man and rat and in those from members of both species with renal hypertension indicate the identity of juxtaglomerular granules as lysosomes.
The
Autographa californica
Baculovirus Genome: Evidence for Multiple Replication Origins
Authors: Pearson Margot , Bjornson Rebecca , Pearson George , Rohrmann George
Published: October 2006

The
Autographa californica
multinucleocapsid nuclear polyhedrosis virus (AcMNPV), which is used for the overexpression of eukaryotic genes and is being engineered for possible use as a viral insecticide, has a circular, supercoiled genome of approximately 128 kilobases. Despite its widespread use, little is known about the mechanism by which AcMNPV replicates. Evidence is presented in this report that AcMNPV origins of DNA replication are repeated sequences each containing several closely related imperfect palindromes that are present in six regions distributed around the genome. Although AcMNPV infection-dependent plasmid replication was initiated by a single complete palindrome, the amount of replication was substantially increased in plasmids containing six or eight palindromes.
MacroH2A, a Core Histone Containing a Large Nonhistone Region
Authors: Pehrson John R. , Fried Victor A.
Published: October 2006

A histone, macroH2A, nearly three times the size of conventional H2A histone, was found in rat liver nucleosomes. Its N-terminal third is 64 percent identical to a full-length mouse H2A. However, it also contains a large nonhistone region. This region has a segment that resembles a leucine zipper, a structure known to be involved in dimerization of some transcription factors. Nucleosomes containing macroH2A may have novel functions, possibly involving interactions with other nuclear proteins.
Dependence of Cortical Plasticity on Correlated Activity of Single Neurons and on Behavioral Context
Authors: Ahissar Ehud , Vaadia Eilon , Ahissar Merav , Bergman Hagai , Arieli Amos , Abeles Moshe
Published: October 2006

It has not been possible to analyze the cellular mechanisms underlying learning in behaving mammals because of the difficulties in recording intracellularly from awake animals. Therefore, in the present study of neuronal plasticity in behaving monkeys, the net effect of a single neuron on another neuron (the "functional connection") was evaluated by cross-correlating the times of firing of the two neurons. When two neurons were induced to fire together within a short time window, the functional connection between them was potentiated, and when simultaneous firing was prevented, the connection was depressed. These modifications were strongly dependent on the behavioral context of the stimuli that induced them. The results indicate that changes in the temporal contingency between neurons are often necessary, but not sufficient, for cortical plasticity in the adult monkey: behavioral relevance is required.
Pygmy Stars: First Pair
Authors: Zwicky F.
Published: October 2006

The binary LP 101-15/16 having the proper motion of 1.62 seconds of arc per year has been studied with the prime-focus spectrograph of the 200-inch (508 cm) telescope. Indications are that LP 101-15/16 is the first pair of pygmy stars ever discovered. One of its components, LP 101-16, is probably a blue pygmy star which is at least four magnitudes fainter than the ordinary white dwarfs. Also, two of the Balmer lines in absorption appear to be displaced toward the red by amounts which indicate the existence of an Einstein gravitational red shift corresponding to about 1000 km sec
-1
. On the other hand LP 101-15 is red and shows an entirely new type of spectrum, which suggests that it may be a first representative of a type of red pygmy star which is 2.5 magnitudes fainter than the M-type dwarf stars of the main sequence.
Mechanism of a Reaction in Vitro Associated with Delayed-Type Hypersensitivity
Authors: Bloom Barry R. , Bennett Boyce
Published: October 2006

The cell type responsible for inhibition by antigen of migration in vitro of peritoneal exudate cells obtained from tuberculin-hypersensitive guinea pigs was studied. Exudate populations were separated into component cell types, the lymphocyte and the macrophage. Peritoneal lymphocytes from sensitive donors were the immunologically active cells in this system, the macrophages, being merely indicator cells which migrate. Sensitized peritoneal lymphocyte populations, upon interaction with specific antigen in vitro, elaborated into the medium a soluble material capable of inhibiting migration of normal exudate cells.
Multicapillary Mixer of Solutions
Authors: Moskowitz Gerard W. , Bowman Robert L.
Published: October 2006

A mixer made from a bundle of glass tubules can mix two solutions within 30 microseconds, with a total-solution flow rate of 1.33 milliliters per second. One solution passes through the interstices of the bundle; the other moves through the lumens of the tubes.
Action of Anionic and Cationic Nerve-Blocking Agents: Experiment and Interpretation
Authors: Blaustein M. P. , Goldman D. E.
Published: October 2006

Barbiturates and anesthetics similar to procaine bind to phospholipids in vitro. The former increase the binding of calcium to the phospholipids; the latter decrease it. The data can be correlated with the effects of these drugs on peripheral nerve. The nonpolar portion of the narcotic agents may lie between the lipid chains of the membrane, with the charged region in close approximation to the polar heads of the phospholipids.
Control of Conception by Hormonal Steroids
Authors: Pincus Gregory
Published: October 2006

Experience with the use of progestinestrogen preparations as oral contraceptives indicates that they inhibit fertility by preventing ovulation and that their action is clearly a physiological process. Their efficiency as antifertility agents is extraordinary. An examination of their physiological effects over many years of use indicates that actions to be expected from the hormonal properties of the steroidal components occur but that none of these constitute pathological phenomena. Rather, we observe a state conditioned by the rather constant hormonal milieu resulting from the particular dosages and regimes of use. Thus far, despite use by millions of women, none of the alleged pathological adverse reactions (such as thromboembolism) to the drugs have been established as more than coincidental. Clearly beneficial effects are inherent not only in the avoidance of risks attendant upon pregnancy but also in improvements in menstrual function (regularity, reduction of hypermenorrhea and dysmenorrhea) and perhaps in a prophylactic effect upon certain abnormalities of the reproductive tract (cervical anaplasia, endometrial cystic and adenomatous hyperplasia). Psychogenic phenomena due to use of oral contraceptives are difficult to measure, but beneficial effects would seem to outweigh adverse ones.
Thyroid Hormone: Effects on Electron Transport
Authors: Bronk J. Ramsey
Published: October 2006

Thyroidectomy markedly reduces the oxidative capacity of rat liver mitochondria. After the injection of triidothyronine about half of the lost capacity is recovered within 3 hours. This rapid recovery is not associated with any change in the amounts of electron transport components, although the activities of cytochromes
b
and
c
are significantly increased by the hormone.
Tropopause Detected by Radar
Authors: Atlas David , Hardy Kenneth R. , Glover Kenneth M. , Katz Isadore , Konrad Thomas G.
Published: October 2006

The tropopause has been detected by ultrasensitive, narrow-beam, microwave (10.7-centimeter) and ultrahigh-frequency (71.5-cm) radars. Its reflectivity is consistent with that expected theoretically for a refractively turbulent medium. Indications are that the layer is also mechanically turbulent, and that electromagnetic scatter techniques may be used to detect high-altitude clear-air turbulence.
Differentiation in vitro: Effects of Sephadex Fractions of Chick Embryo Extract
Authors: Coon Hayden G. , Cahn Robert D.
Published: October 2006

Chicken embryo extract has been fractionated into high- and low-molecular-weight components on Sephadex G-25. Media supplemented with the low-molecular-weight fraction (L) support full differentiation in clones of cartilage and of pigmented retina cells from chicken embryos. Growth rates of such cultures in L-supplemented media are greater than in media without embryo extract, and plating efficiencies are higher than in media with or without whole embryo extract. The high-molecular-weight fraction (H) in low concentrations also stimulates growth and plating efficiency, but inhibits the expression of differentiation.
Plasma Kinins and Cortisol: A Possible Explanation of the Anti-Inflammatory Action of Cortisol
Authors: Cline Martin J. , Melmon Kenneth L.
Published: October 2006

Kinins are naturally occurring vasoactive polypeptides thought to be mediators of acute inflammatory responses. Kinins are released from a plasma protein substrate by glass-activated plasma enzymes (kallikreins) or by isolated intact granulocytes. Cortisol in concentrations of 2.5 × 10
-6
to 2.5 × 10
-5
M
prevented the release of active kinin from substrate by granulocytes or contact with glass. Deoxycorticosterone, progesterone, and etiocholanolone in comparable concentrations were significantly less effective in preventing kinin release. Plasma obtained from patients receiving prednisone released no kinin after activation by glass and less kinin than control plasma when exposed to granulocytes. Cortisol also partially inhibited the release of kinin by purified urinary kallikrein. Certain adrenocorticosteroids may exert their anti-inflammatory effect by inhibiting the release of plasma kinins. Steroids may act in part by preventing interaction between the activated kallikrein and its substrate.
Chemical Pruning of Plants
Authors: Cathey H. M. , Steffens G. L. , Stuart N. W. , Zimmerman R. H.
Published: October 2006

The lower alkyl esters of the C
8
to C
12
fatty acids and the C
8
to C
10
fatty alcohols selectively kill or inhibit the terminal meristem without damaging the axillary meristems, foliage, or stem tissue of a wide variety of plants. The axillary meristems develop at nearly the same time as those of plants whose terminal meristems have been removed manually. The concentration of the fatty acid esters and alcohols required to kill the terminal meristem range from 0.025 to 0.05
M
for herbaceous plants, 0.05 to 0.16
M
for semi-woody plants, and 0.16 to 0.27
M
for woody plants.
High-Temperature Synthesis of Aromatic Hydrocarbons from Methane
Authors: Oró J. , Han J.
Published: October 2006

Arenes of 1, 2, 3, 4 and more rings have been synthesized in a flow system by passing methane through silica gel at 1000°C. Yields of 4.8 to 7.2 percent have been obtained per single pass. As determined by combined gas chromatography-mass spectrometry, the major compound synthesized that are of less than 5 rings are benzene, naphthalene, acenaphthylene, phenanthrene, fluoranthene, and pyrene. Under certain conditions (presence of ammonia and water), small amounts of aliphatic hydrocarbons are also synthesized. Even-carbon-numbered hydrocarbons (aromatic as well as aliphatic) predominate, to the extent that about 97 percent of the total weight of the analyzed arenes have even numbers of carbon atoms.
Oxygen as a Primary Species in Radiolysis of Water
Authors: Daniels Malcolm , Wigg Eric
Published: October 2006

Recent results are summarized of γ-radiolysis of dilute nitrate solutions at neutral
p
H in the presence of oxygen and hydrogen as radical scavengers. Complete analysis of the system leads to values of the primary yields showing a net deficit of oxidized products of ∼0.4. Analysis of results already available for the oxygen yield shows that oxygen originated from the radiolysis of water with a g value of ∼0.1 (g values are derived values for yields of primary species for 100 electron volts). This finding gives material balance and provides evidence of oxygen being a product of water radiolysis.
A Yeast Chromosomal Origin of DNA Replication Defined by Multiple Functional Elements
Authors: Marahrens York , Stillman Bruce
Published: October 2006

Although it has been demonstrated that discrete origins of DNA replication exist in eukaryotic cellular chromosomes, the detailed organization of a eukaryotic cellular origin remains to be determined. Linker substitution mutations were constructed across the entire
Saccharomyces cerevisiae
chromosomal origin,
ARS1
. Functional studies of these mutants revealed one essential element (A), which includes a match to the ARS consensus sequence, and three additional elements (B1, B2, and B3), which collectively are also essential for origin function. These four elements arranged exactly as in
ARS1
, but surrounded by completely unrelated sequence, functioned as an efficient origin. Element B3 is the binding site for the transcription factor-origin binding protein ABF1. Other transcription factor binding sites substitute for the B3 element and a trans-acting transcriptional activation domain is required. The multipartite nature of a chromosomal replication origin and the role of transcriptional activators in its function present a striking similarity to the organization of eukaryotic promoters.
Malaria Infection (
Plasmodium lophurae
): Changes in Free Amino Acids
Authors: Sherman Irwin W. , Mudd J. Brian
Published: October 2006

The course of infection of the avian malaria
Plasmodium lophurae
in the duckling is characterized by striking increase in the intraerythrocytic free amino acid pool. The quality and quantity of this change result from the presence of the parasite and for the most part reflect the free amino acid pool of the growing plasmodium. No significant changes in the free amino acids in plasma were noted during infection.
From Enzymatic Adaptation to Allosteric Transitions
Authors: Monod Jacques
Published: October 2006

The research by my collaborators and myself since 1945 has been carried out entirely at the Pasteur Institute. This work has received decisive assistance from numerous institutions, in particular the Centre National de la Recherche Scientifique, the Rockefeller Foundation of New York, the National Science Foundation and the National Institutes of Health of the United States, the Jane Coffin Childs Memorial Fund, the Commissariat á l'Energie Atomique, and the Délégation Générale á la Recherche Scientifique et Technique. A donation by Mesdames Edouard de Rothschild and Bethsabee de Rothschild permitted, in large part, the establishment in 1954 of the Department of Cellular Biochemistry at the Pasteur Institute.
Phosphorylation of Nuclear Protein Early in the Course of Gene Activation in Lymphocytes
Authors: Kleinsmith Lewis J. , Allfrey Vincent G. , Mirsky Alfred E.
Published: October 2006

Human lymphocytes treated with phytohemagglutinin undergo extensive gene activation, as evidenced by augmented synthesis of ribonucleic acids. This activation is preceded by an early stimulation in the rate of phosphorylation and dephosphorylation of nuclear proteins. This finding is consistent with a hypothesized role of phosphoproteins in the modification of chromatin structure and in modulation of the template activity of DNA in vivo.
Species Specific Effect of Acetylcholine on Bivalve Rectums
Authors: Greenberg M. J.
Published: October 2006

The pharmacology of acetylcholine and 5-hydroxytryptamine on the rectums of
Katelysia rhytiphora
and
K. scalarina
was found to be similar, in general, to that of other bivalves. However, while acetylcholine causes a fast twitch in the rectum of
K. rhytiphora
, the activity and tone of the
K. scalarina
rectum are depressed except at high concentrations of the drug. The two species can be distinguished by these responses, and, therefore, these rectums are useful experimental objects for studying the physiology of molluscan visceral muscle.
Centromere: Absence of DNA Replication during Chromatid Separation in Human Fibroblasts
Authors: Comings David E.
Published: October 2006

Cultures of human fibroblasts were labeled briefly with tritiated thymidine and fixed; autoradiographs were made and exposed for 3½ months. No labeling was noted over the centromere of metaphase or anaphase chromosomes. The technique was sensitive to replication at the centromere of a DNA helix only 2.5 microns long, considerably shorter than the estimated length of a replicon in humans. This suggests that chromatid separation during mitosis is not associated with delayed replication of a short segment of chromosomal DNA.
Open-Field Behavior in Mice: Evidence for a Major Gene Effect Mediated by the Visual System
Authors: DeFries J. C. , Hegmann J. P. , Weir Morton W.
Published: October 2006

In segregating F
2
, F
3
, and F
4
generations, albino mice had lower activity and higher defecation scores than pigmented animals when tested in a brightly lighted open field. These differences persisted when members of an F
5
generation were tested under white light, but largely disappeared under red light. Thus it was concluded that there is a major gene effect on the quantitative traits of open-field activity and defecation which is mediated by the visual system and that albino mice are more photophobic than pigmented mice under conditions of bright illumination.
Nuclei from Rat Liver: Isolation Method That Combines Purity with High Yield
Authors: Blobel Gunter , Potter Van R.
Published: October 2006

A procedure is described that gives almost quantitative separation of clean nuclei from a homogenate of rat liver. It is a modification of methods that use concentrated sucrose solutions rather than citric acid or detergents and, therefore, permits further quantitative fractionation of cytoplasmic components.
Visual Pathway Mediating Pineal Response to Environmental Light
Authors: Moore Robert Y. , Heller Alfred , Wurtman Richard J. , Axelrod Julius
Published: October 2006

Activity of the melatonin-forming enzyme, hydroxyindole-
O
-methyltransferase, in rat pineal is increased when the animal is exposed to continuous darkness, and it is decreased by exposure to continuous light. Response to environmental light is initiated in the retina and transmitted to the pineal by way of the central nervous system and the cervical sympathetics. The central visual pathway essential for mediation of this response is the inferior accessory optic tract. Visual pathways to thalamus and tectum do not participate in this response.
L-Asparaginase: Toxicity to Normal and Leukemic Human Lymphocytes
Authors: Schrek Robert , Dolowy William C. , Ammeraal Robert N.
Published: October 2006

Quantitative in vitro tests showed that purified preparations of L-asparaginase from
Escherichia coli
were more toxic to blood lymphocytes from 12 of 15 patients with chronic lymphocytic leukemia than to lymphocytes from 25 persons with normal hemograms. Incubation for 7 days with 10 units per milliliter killed, on the average, 77 percent of leukemic and 34 percent of normal lymphocytes. The reagent produced appreciable toxicity to leukemic lymphocytes after 2 days of incubation.
Visual Reaction Times on a Circle about the Fovea
Authors: Payne W. H.
Published: October 2006

Reaction times to a dim photopic stimulus were measured on a circle about the fovea, 15° from the line of direct vision. Large variations in reaction time were found on various half meridians and were interpreted as reflecting the distribution of retinal receptors.
Mongoose Throwing and Smashing Millipedes
Authors: Eisner Thomas , Davis Joseph A.
Published: October 2006

African millipedes of the genus
Sphaerotherium
coil into tight spheres when disturbed. Their tough skeletal armor offers protection against some predators, but not against the African banded mongoose
Mungos mungo
, which smashes them by hurling them against rock.
Metabolism of Rotenone in vitro by Tissue Homogenates from Mammals and Insects
Authors: Fukami Jun-ichi , Yamamoto† Izuru , Casida John E.
Published: October 2006

Hydroxylation of rotenone in vitro in the enzyme system composed of microsomes and reduced nicotinamide-adenine dinucleotide phosphate, and in living mice and houseflies, yields products tentatively identified as rotenolone I; rotenolone II; 8′-hydroxyrotenone; 6′,7′-dihydro-6′,7′-dihydroxyrotenone; two rotenolones of each of the last-mentioned two compounds; and uncharacterized polar materials. The toxicity of certain of these rotenoids to mice is of the same order as that of rotenone.
Fine Structure of RNA Codewords Recognized by Bacterial, Amphibian, and Mammalian Transfer RNA
Authors: Marshall Richard E. , Caskey C. Thomas , Nirenberg Marshall
Published: October 2006

Nucleotide sequences of 50 RNA codons recognized by amphibian and mammalian liver transfer RNA preparations were determined and compared with those recognized by
Escherichia coli
transfer RNA. Almost identical translations were obtained with transfer RNA from guinea pig liver,
Xenopus laevis
liver (South African clawed toad), and
E. coli
. However, guinea pig and
Xenopus
transfer RNA differ markedly from
E. coli
transfer RNA in relative response to certain trinucleotides. Transfer RNA from mammalian liver, amphibian liver, and amphibian muscle respond similarly to trinucleotide codons. Thus the genetic code is essentially universal, but transfer RNA from one organism may differ from that of another in relative response to some codons.
Photoinduced DNA-Protein Cross-Links and Bacterial Killing: A Correlation at Low Temperatures
Authors: Smith Kendric C. , O'Leary Mary E.
Published: October 2006

The increased sensitivity of
Escherichia coli
to killing by ultraviolet irradiation when frozen and the variation in this sensitivity as a function of the temperature during irradiation have been correlated with changes in the amount of DNA that was cross-linked to protein by ultraviolet light. These variations in sensitivity to killing do not correlate with the production of thymine dimers.
Tetraethylammonium Ions: Effect of Presynaptic Injection on Synaptic Transmission
Authors: Kusano K. , Livengood D. R. , Werman R.
Published: October 2006

Tetraethylammonium ions were injected into the presynaptic axon of the squid giant synapse. Injection of these ions caused prolongation of the action potential with decreased outward current. The prolonged spike was associated with increased release and prolonged activity of the transmitter substance. Although the amplitude of the postsynaptic potential increased with presynaptic depolarization, strong depolarization blocked transmitter release. In the injected presynaptic axon, transmitter release was blocked by 10
—6
gram of tetrodotoxin per milliliter. Transmitter release appears to be under control of presynaptic potential levels.
Fast Light-Evoked Potential from Leaves
Authors: Ebrey Thomas G.
Published: October 2006

When a leaf is illuminated with an intense flash of light, an electrical response with a time course in milliseconds can be recorded. This response was obtained between two wick electrodes placed at different positions on top of the leaf, with the entire leaf uniformly illuminated by the flash. During the first millisecond or so, the electrode nearer the apex of the leaf always became negative with respect to an electrode at the base, which indicates that the voltage-generating source is fixed longitudinally in the leaf.
Voluntary Control of Microsaccades during Maintained Monocular Fixation
Authors: Steinman Robert M. , Cunitz Robert J. , Timberlake George T. , Herman Magdalena
Published: October 2006

A contact-lens technique was used to record eye movements made by two subjects instructed either to "fixate" stationary white-light targets or to "hold" their eyes in position in the presence of the same targets. A marked reduction in saccade rate, frequently reaching zero throughout 9.8-second trials, was observed under the "hold" instruction.
Learning-Set Formation by Mink, Ferrets, Skunks, and Cats
Authors: Doty Barbara A. , Jones C. Neal , Doty Larry A.
Published: October 2006

The ability of mink, ferrets, skunks, and cats to learn to discriminate between objects was compared. Performance of mink and ferrets was similar to that reported for primates. This observation suggests that there is considerable overlap among mammals in ability to form learning sets.
Apple Fruit-Set: Evidence for a Specific Role of Seeds
Authors: Dennis Frank G.
Published: October 2006

An extract of immature Wealthy apple seeds, containing substances with gibberellin activity, was applied to unpollinated blossoms of the same variety, resulting in the production of mature seedless fruits. The implications with respect to the normal process of fruit-set are discussed.
Mössbauer Analysis of Iron in Clay Minerals
Authors: Weaver Charles E. , Wampler J. M. , Pecuil T. E.
Published: October 2006

Mössbauer absorption spectrography can be used to establish the presence of Fe
2+
and Fe
3
in clay minerals. In the sheet structure silicates, octahedrally coordinated iron can be distinguished from tetrahedrally coordinated iron. Siderite and goethite, common contaminants of the clay minerals, can usually be detected. Goethite has a well-organized structure, though, owing to its fine grain size, it may appear to be amorphous to x-rays. The various families of clay minerals show minor differences in isomer shift and quadrupole splitting values, caused by variations in the character of the octahedral layer.
Magnetic Fields around the Torso: Production by Electrical Activity of the Human Heart
Authors: Cohen David
Published: October 2006

A search was made outside the torso for fluctuating magnetic fields produced by the heart. Detector and subject were housed in a highly shielded enclosure. Magnetic signals with amplitudes of 10
-8
to 10
-7
gauss were detected synchronously with the electrocardiogram, confirming previous reports. A magnetocardiographic chest map, consisting of the magnetic field plotted against time at various spatial positions, shows general QRS and T-wave structure, as in the electrocardiogram; this structure varies with spatial position.
Anaerobic Biodegradation of DDT to DDD in Soil
Authors: Guenzi W. D. , Beard W. E.
Published: October 2006

DDT labeled with carbon-14 was added to soil, and the mixture was incubated anaerobically for 2 weeks and 4 weeks. DDT and seven possible decomposition products were separated by thin-layer chromatography, and the radioactivity of material from individual spots was determined by liquid scintillation. The DDT was dechlorinated by soil microorganisms to DDD, and only traces of other degradation products were detected. No degradation of DDT was detected in sterile soil.
Transport and Phosphorylation as Factors in the Antitumor Action of Cytosine Arabinoside
Authors: Kessel David , Hall Thomas C. , Wodinsky Isidore
Published: October 2006

Survival of mice bearing different transplantable leukemias and treated with cytosine arabinoside was compared with uptake and subsequent phosphorylation of the drug in vitro. Capacity for nucleotide formation was correlated with response and is apparently an important determinant of drug sensitivity. Drug uptake, although apparently mediated, was similar in all cell lines.
Cell Division: Direct Measurement of Maximum Tension Exerted by Furrow of Echinoderm Eggs
Authors: Rappaport R.
Published: October 2006

Tensions exerted by cleavage furrows in isometric contraction were measured by means of flexible glass needles whose characteristics of bending had already been determined. The tension of
Astriclypeus manni
furrows in second division is 3.04 × 10
-3
± 0.95 × 10
-3
dyne; that for
Pseudocentrotus depressus
eggs in first division is 2.00 × 10
-3
± 0.43 × 10
-3
dyne. The tension required for cleavage probably does not exceed 1.5 × 10
-3
dyne. According to existing morphological evidence, these values can be accounted for by a substance whose capacity for exerting tension does not exceed that of an actomyosin thread.
Spruce Budworm Mortality as a Function of Aerial Spray Droplet Size
Authors: Himel Chester M. , Moore Arthur D.
Published: October 2006

The size and number of aerial spray drops impinging on spruce budworm in its conifer forest habitat were determined by means of a new tracer method that uses fluorescent particles in a liquid spray. Examination of 1113 larvae affected by an experimental insecticide that had been applied to a 5000-acre (2024-ha) test area in Montana showed that 93 percent had not been contacted by any droplets larger than 50 μ in diameter. Small numbers of droplets 50 to 100 μ in diameter were found on 7 percent of the larvae, along with lethal numbers of smaller drops. No evidence was found that significant numbers of drops larger than 100 μ reached the target insects. Because about 95 percent of the spray applied to forests by current methods consist of droplets larger than 50 μ, the biologically effective portion of the drop spectrum is only a few percent. The data foreshadow a major potential reduction in insecticide requirements for the successful control of spruce budworm.
Submaxillary Gland of Mouse: Properties of a Purified Protein Affecting Muscle Tissue in vitro
Authors: Attardi Domenica G. , Schlesinger Milton J. , Schlesinger Sondra
Published: October 2006

A protein from the salivary gland of mice has been highly purified. It affects embryonic muscle tissue in vitro and has both esterase and peptidase activities. Addition of the pure protein to tissue culture in synthetic medium causes dissociation of muscle fibers in individual myoblasts with loss of myosin. This biological activity, as well as the esterase activity, is inhibited by low concentrations of phenylmethanesulfonyl fluoride; this suggests that the effect on the tissue is a consequence of the protein's enzymatic activities.
Pulmonary Ventilation Measured from Body Surface Movements
Authors: Mead Jere , Peterson Norman , Grimby Gunnar , Mead Judson
Published: October 2006

Changes in anteroposterior diameters of the rib cage and abdomen are sensed with magnetometers and summed to give outputs which are very nearly linearly related to changes in lung volume. The volume events of breathing can be measured without recourse to a mouthpiece or face mask, other than for calibration, and with minimal encumbrance to the subject.
Oxygen Tension Changes Evoked in the Brain by Visual Stimulation
Authors: Gijsbers Karel J. , Melzack Ronald
Published: October 2006

Localized changes in oxygen tension were recorded with platinum cathodes placed in the lateral geniculate nucleus in both anesthetized and awake cats. The amplitude of the responses increased with increasing stimulus intensity, but decreased with increasing flash rate. Both increases and decreases in cathode current were produced by steady illumination. The characteristics of the responses suggest that the responses reflect localized variations in blood flow, produced in turn by changes evoked in the tonic neural activity of the lateral geniculate nucleus.
Short-Term Memory, Parsing, and the Primate Frontal Cortex
Authors: Pribram K. H. , Tubbs W. E.
Published: October 2006

Removal of the frontal cortex of primates resulted earlier in a psychological deficit usually classified in terms of short-term memory. This classification is based on impairment in performance of delayed-response or alternation-type tasks. We report an experiment in which the classical 5-second-delay right-left-right-left (R-L-R-L) alternation task was modified by placing a 15-second interval between each R-L couplet: R-L . . . R-L . . . R-L . . . . This modification made it possible for monkeys with frontal lesions, which had failed the classical task, to perform with very few errors. The result suggests that proper division, parsing of the stream of stimuli to which the organism is subjected, is a more important variable in the mechanism of short-term memory than is the maintenance of a neural trace per se.
Enzymatic Identification of Fish Products
Authors: Wilson A. C. , Kitto G. B. , Kaplan N. O.
Published: October 2006

Comparative enzymological techniques were used to distinguish between the muscle lactate dehydrogenases of 26 fish species. Intergeneric differences in enzymatic properties were frequently encountered. The techniques revealed, in addition, that some commercial samples of frozen fish fillets, labeled "haddock," contained cod lactate dehydrogenase.