bluuebunny/crossref_metadata_2025 huggingface dataset:
Location of the Second Gene Required for Expression of the Leukemia-Associated Mouse Antigen G
IX
Authors: Stockert Elisabeth , Sato Hidetoshi , Itakura Katsuaki , Boyse Edward A. , Old Lloyd J. , Hutton John J.
Published: October 2006

Some mouse strains express G
IX
antigen on their thymocytes; others do not. Expression depends on two genes,
Gv-1
and
Gv-2
, in linkage groups IX and I, respectively. Cells producing leukemia virus, however, express G
IX
antigen regardless of their inherited
Gv-1
and
Gv-2
genotype.
Invertebrate Facultative Anaerobiosis
Authors: Hochachka P. W. , Mustafa T.
Published: October 2006

The unique pattern of anaerobic carbohydrate metabolism in invertebrate facultative anaerobes
serves to couple other substrate-level phosphorylations to the glycolytic reactions, thus increasing the potential yield of high-energy phosphate compounds.
Currently, two important coupling sites can be identified:
Moving Visual Scenes Influence the Apparent Direction of Gravity
Authors: Dichgans Johannes , Held Richard , Young Laurence R. , Brandt Thomas
Published: October 2006

When an observer views a wide-angled display rotating around his line of sight, he both feels his body tilted and sees a vertical straight edge tilted opposite to the moving stimulus. Displacement of the perceived vertical increases with stimulus speed to reach a maximum (averaging 15 degrees) at 30 degrees per second.
Synthetic Rat Scotophobin Induces Dark Avoidance in Mice
Authors: Malin David H. , Guttman Helene N.
Published: October 2006

Two independent research groups replicate alteration of dark preference to dark avoidance by mice injected with synthetic scotophobin, a pentadecapeptide.
Fossilization of Bermuda Patch Reefs
Authors: Scoffin T. P.
Published: October 2006

Living corals on Bermuda patch reefs build a primary framework which, in places, is so destroyed by boring organisms that the reef surface subsides. Organisms that encrust the reef cavities are preferentially preserved as the framework is bored. Burial by loose sediment stops framework growth, encrustation, and boring. Finally, cementation completes fossilization.
Translation of Bacteriophage Qβ Messenger RNA in a Murine Krebs 2 Ascites Tumor Cell-Free System
Authors: Aviv H. , Boime I. , Loyd B. , Leder P.
Published: October 2006

Qβ is a small bacterial virus whose three genes are encoded in a single-stranded molecule of RNA. This RNA serves directly as the Qβ message. Here we describe conditions under which RNA corresponding to the coat cistron of this bacterial virus is translated in a system derived from mammalian cells. Translation of the bacterial virus messenger RNA is less effective than that of mammalian globin messenger RNA, but is somewhat enhanced by mild alkali treatment of the messenger. The synthesized product when subjected to electrophoresis migrates with authentic Qβ coat protein and yields tryptic peptides that correspond to those derived from the Qβ coat protein.
Implantation of Exogenous Enzymatic Activity in Isolated Alveolar Macrophages
Authors: Theodore James , Acevedo Julio C. , Robin Eugene D.
Published: October 2006

Alveolar macrophages acquired the capacity to oxidize uric acid after exposure to uricase. Presumably this resulted from intracellular incorporation of the enzyme by endocytosis. This approach may provide a general method for (i) testing regulatory biochemical mechanisms, (ii) therapeutic replacement of deficient regulatory macromolecules, and (iii) studying environmental factors that produce genetic alterations.
Radiation Effects in Free-Ranging Pocket Mice,
Perognathus parvus
, during the Breeding Season
Authors: O'Farrell Thomas P. , Hedlund John D. , Olson Richard J. , Gilbert Richard O.
Published: October 2006

Captive and free-ranging Great Basin pocket mice,
Perognathus parvus
, were exposed to ionizing radiation during the breeding season, April-June, in 1971. The values for the median lethal dose (LD
50
) at 30 days plus or minus the standard deviation were 880 ± 14 rads and 780 ± 27 rads, respectively, and the slopes of the survivorship curves were significantly different. These differences suggested that there was a synergism between radiation-induced and environmental sources of mortality, since the field data were corrected for natural mortality (5 percent) in the controls.
Pituitary Gonadotrophs: Nuclear Concentration of Radioactivity after Injection of [
3
H]Testosterone
Authors: Sar Madhabananda , Stumpf Walter E.
Published: October 2006

Gonadotrophs and castration cells in the male rat pituitary showed nuclear concentration of radioactivity 1 hour after [1,2,6,7-
3
H]testosterone injection. Thyrotrophs and acidophils did not retain radioactivity; also the cells of the intermediate and posterior lobes did not accumulate radioactivity. The autoradiographic results suggest a direct and selective action of androgen on gonadotrophs, which contrasts with the action of estradiol which was shown earlier to bind not only to basophils but to acidophils and chromophobes as well.
Cytidylic Acid "a" Trihydrate: Structure and Conformation
Authors: Kartha Gopinath , Ambady Gopal , Viswamitra M. A.
Published: October 2006

Cytidylic acid "a" (cytidine 2′-monophosphate) crystallizes in the triclinic space group
P
1 with two molecules of cytidine monophosphate (C
9
H
14
O
8
N
3
P) and six molecules of water in the unit cell. X-ray analysis of this crystal shows that in both molecules, the base is in the
anti
conformation, the ribose ring is C(2′)-
endo
puckered, and the hydroxyl O(5′) is
gauche-gauche
. The two molecules are linked by a short hydrogen bond through the phosphate oxygens.
Polar Desert Adaptations of a High Arctic Plant Species
Authors: Teeri J. A.
Published: October 2006

Plants of
Saxifraga oppositifolia
(Saxifragaceae) possess metabolic adaptations that allow them to grow successfully in polar desert microenvironments. Net photosynthesis (net carbon uptake) continues to be positive during drought until the leaf water stress declines to the range of -21 to -29 bars, which is considerably below the nonstress range of 0 to -10 bars. The plants can survive leaf water stresses of at least -44 bars in the field and leaf water stresses of -55 bars in a growth chamber.
Haptic Illusion: Apparent Elongation of a Disk Rotated between the Fingers
Authors: Cormack Robert H.
Published: October 2006

A disk (coin) turned end over end between thumb and forefinger feels longer to the turning hand. The illusion grows rapidly for 30 seconds but does not become asymptotic within 60 seconds. The illusion increases with coin size and turning rate, and is independent of holding pressure. It appears to involve illusory mechanisms in both hands.
Aqueous Central Cavity in Aspartate Transcarbamylase from
Escherichia coli
Authors: Evans D. R. , Warren S. G. , Edwards B. F. P. , McMurray C. H. , Bethge P. H. , Wiley D. C. , Lipscomb W. N.
Published: October 2006

A three-dimensional x-ray diffraction study of aspartate transcarbamylase to 5.5-angstrom resolution, with the aid of four isomorphous heavy atom derivatives, indicates the presence of a central aqueous cavity approximating an oblate spheroid about 25 by 50 by 50 angstroms in dimension, within a molecule about 90 by 110 by 110 angstroms in largest dimensions.
Sea Urchin Sperm-Egg Interactions Studied with the Scanning Electron Microscope
Authors: Tegner Mia J. , Epel David
Published: October 2006

Scanning electron microscopy of the outer surface of sea urchin eggs sampled at intervals during the first 3 minutes after insemination reveals the detailed structural changes of the vitelline layer during its transformation into the fertilization membrane. A sperm attachment-detachment sequence is described for the large number of sperm which transitorily bind every egg during fertilization.
Competition between Color Morphs of the Polychromatic Midas Cichlid
Cichlasoma citrinellum
Authors: Barlow George W.
Published: October 2006

The Midas cichlid,
Cichlasoma citrinellum
, is a polychromatic fish that occurs in Nicaragua. All of these fish start life as normally colored, cryptic individuals. In some populations a few fish change into conspicuously colored morphs, most frequently gold. When kept in unmixed color groups, golds and normals grow at the same rate; but when they are mixed, growth of the golds becomes faster and that of the normals slower. Golds dominate normals in contests over food, which accounts for their advantage.
Evoked Potential Correlates of Expected Stimulus Intensity
Authors: Begleiter H. , Porjesz Bernice , Yerre Consolacion , Kissin B.
Published: October 2006

The electrophysiological responses to a flash of medium intensity have different wave shapes in trials in which the occurrence of bright stimuli or dim stimuli is expected. When a bright or dim stimulus is signaled, the potentials evoked by the medium stimulus resemble the responses evoked by a real bright or dim flash.
Maternal Behavior in the Rat: Facilitation through Gonadectomy
Authors: Leon Michael , Numan Michael , Moltz Howard
Published: October 2006

Virgin rats were ovariectomized and tested for induction of maternal behavior by being housed with neonatal young. A postoperative interval of 8 weeks yielded an average latency for the onset of maternal behavior significantly lower than that for intact controls or for virgin females ovariectomized 4 weeks before testing. Replacement of estrogen in the group ovariectomized for 8 weeks or injection of the estrogen antagonist ethamoxytriphetol (MER-25) in the group ovariectomized for 4 weeks changed the average latencies accordingly. Parallel results were obtained for males that were castrated 4 or 8 weeks before testing. It is concluded (i) that maternal behavior is under gonadal control and that this control is normally inhibitory; and (ii) that only after long-term removal of the gonads, resulting presumably in the complete clearance of estrogen and testosterone, is the maternal mediating system finally released from steroid suppression.
Yukon River: Evidence for Extensive Migration during the Holocene Transgression
Authors: Knebel Harley J. , Creager Joe S.
Published: October 2006

The shift of the Yukon River, during the Holocene sea-level transgression, from south of Nunivak Island during the Wisconsin maximum to its present location (a distance greater than 300 kilometers) is indicated by remanent channels, distinct subbottom structures, deltaic sediments, and anomalous rates of sediment accumulation on the continental shelf of the east-central Bering Sea. These features were produced as the ancestral river migrated northward across the easternmost part of this area before 11,000 years ago.
Isolated Adrenal Cortex Cells: Hypersensitivity to Adrenocorticotropic Hormone after Hypophysectomy
Authors: Sayers George , Beall Robert J.
Published: October 2006

Cells from the adrenals of hypophysectomized rats (up to 28 days after operation) require less adrenocorticotropic hormone to induce one-half maximal rate of production of 3′,5′-adenosine monophosphate than do cells from the adrenals of intact rats. A corresponding increase in sensitivity is reflected in the steroidogenic response to adrenocorticotropic hormone up to 2 days after hypophysectomy.
Rana pipiens
Complex: Hemoglobin Phenotypes of Sympatric and Allopatric Populations in Arizona
Authors: Platz James E. , Platz Anna L.
Published: October 2006

Electrophoretic comparison of hemoglobin samples from numerous populations of
Rana pipiens
in Arizona reveals three distinct phenotypes that closely correlate with morphological differences. Hemoglobin samples from sympatric locations contain parental phenotypes with only the occasional occurrence of a hybrid. These data support the contention that the
Rana pipiens
complex consists of several species.
Serotonin: Radioimmunoassay
Authors: Peskar Bernard , Spector Sydney
Published: October 2006

The development of a radioimmunoassay for serotonin is described. Serotonin is made antigenic by coupling it to bovine serum albumin. Thrombocyte-free plasma instead of serum from the immunized animals is used for radioimmunoassay. Less than 1 ng serotonin can be measured by this procedure.
Helium Flux from the Earth's Mantle as Estimated from Hawaiian Fumarolic Degassing
Authors: Naughton John J. , Lee J. H. , Keeling Diana , Finlayson J. B. , Dority Guy
Published: October 2006

Averaged helium to carbon dioxide ratios measured from systematic collections of gases from Sulphur Bank fumarole, Kilauea, Hawaii, when coupled with estimates of carbon in the earth's crust, give a helium flux of 1 × 10
5
atoms per square centimeter per second. This is within the lower range of other estimates, and may represent the flux from deep-seated sources in the upper mantle.
Translocation Trisomic Mice: Production by Female but Not Male Translocation Carriers
Authors: Eicher Eva M.
Published: October 2006

In man, there is generally a greater chance for a translocation trisomic child to be born if the mother rather than the father is the translocation carrier. The same type of inheritance has occurred in the mouse. Female mice heterozygous for the reciprocal translocation
T
(14;15)6
Ca
have produced a high frequency of translocation trisomic offspring. Male mice heterozygous for the same translocation have produced no translocation trisomic offspring. Thus, the laboratory mouse may provide a model for studying the cause of this phenomenon.
Parallel Evolution in Lichen-Forming Fungi
Authors: Culberson William Louis , Culberson Chicita F.
Published: October 2006

The asexual lichen-forming fungus
Parmelia hypotropa
has two common chemical races that differ sharply in biogeography and niche characteristics and appear to have been derived by morphologic parallelism from chemically identical races of the closely related
Parmelia perforata
, which is sexual. Among the lichen fungi many chemically variable asexual morphs, which conventional taxonomies treat as species, are probably polyphyletic like
Parmelia hypotropa
.
Visual Temporal Order: A New Illusion
Authors: Sekuler Robert , Tynan Paul , Levinson Eugene
Published: October 2006

Brief visual stimuli presented in rapid sequence, one to the left and one to the right, appear to occur left first, then right, regardless of the actual order of presentation. This illusion persists under conditions of forced-choice testing and does not vary with presentation to the same or opposite retinal hemifields, A series of experiments suggests that this illusion may be the product of an internal mechanism that scans visual inputs in a left-to-right order.
Hyaluronate Inhibition of Chondrogenesis: Antagonism of Thyroxine, Growth Hormone, and Calcitonin
Authors: Toole Bryan P.
Published: October 2006

The formation of cartilage-like aggregates in high-density stationary cultures of trypsinized chick embryo precartilage cells is blocked by low concentrations of hyaluronate. Thyroxine (and triiodothyronine), growth hormone, calcitonin, and adenosine 3′,5′-monophosphate prevented this inhibition by hyaluronate, whereas other hormones tested did not.
Applications of Artificial Intelligence: Relationships between Mass Spectra and Pharmacological Activity of Drugs
Authors: Ting Kai-Li H. , Lee R. C. T. , Milne G. W. A. , Shapiro M , Guarino A. M.
Published: October 2006

The possibility that the mass spectrum and pharmacological activity of a compound may be directly related has been explored with the help of various computer-based pattern-recognition techniques. The relationship appears to hold at least for tranquilizers and sedatives, and compounds with one or the other of these two pharmacological activities can thus be classified from their mass spectra with a high degree of accuracy.
Iodine-129/Xenon-129 Age of Magnetite from the Orgueil Meteorite
Authors: Herzog Gregory F. , Anders Edward , Alexander E. C. , Davis P. K. , Lewis R. S.
Published: October 2006

Magnetite from the Orgueil C1 chondrite is only 2.0 ± 2.4 million years older by the iodine-xenon method than the next oldest meteorite, the Karoonda C4 chondrite. This age ties the primitive C1 chondrites to the extensive iodine-xenon chronology of normal chrondrites. If Karoonda and Orgueil magnetite formed from similar material, then the age difference is an upper limit to the formation time of these meteorites—and by customary extension, the solar system. Condensation, chondrule formation, accretion, and metamorphism of the Karoonda parent body all seem to have been completed within a few million years.
Electrophysiological Evidence that Abnormal Early Visual Experience Can Modify the Human Brain
Authors: Freeman Ralph D. , Thibos Larry N.
Published: October 2006

Visual resolution in humans is nearly equal for vertically and horizontally oriented detail, but for some subjects there is a substantial difference in resolving power for these orientations. Although subjects who exhibit this difference invariably have ocular astigmatism, optical explanations of the effect can be ruled out. Direct evidence has been found for an electrophysiological correlate to the psychophysical finding. Subjects who have reduced resolution for a pattern of a particular orientation also show a decreased evoked potential response elicited by a target of the same orientation. The results are consistent with the hypothesis that a deficiency of specific features in the early visual input can alter the organization of the visual pathways.
Retrograde State Dependent Learning
Authors: Chute Douglas L. , Wright Dennis C.
Published: October 2006

Sodium pentobarbital administered intravenously after acquisition in a one-trial passive avoidance task results in state dependent (drug dissociated) learning in male albino rats. Findings have methodological implications for drug-based research and theoretical implications for drug discrimination studies. Predictions based on a stimulus generalization hypothesis are not supported, whereas those based on an information storage hypothesis are supported.
Transfer of Experimental Autoimmune Renal Cortical Tubular and Interstitial Disease in Guinea Pigs by Serum
Authors: Steblay Raymond W. , Rudofsky Ulrich
Published: October 2006

Guinea pigs injected with rabbit tubular basement membranes and Freund's adjuvant develop progressive renal cortical tubulointerstitial disease and deposit autoantibodies in their cortical tubular basement membranes. The identical, even fatal, disease may be produced in normal guinea pigs by a single intraperitoneal injection of serums obtained from guinea pigs with this tubulointerstitial disease, provided such serums contain sufficient amounts of autoantibodies against tubular basement membranes.
Nematode Morphogenesis: Localization of Controlling Regions by Laser Microbeam Surgery
Authors: Samoiloff Martin R.
Published: October 2006

Laser microbeam studies reveal that postembryonic development of the free-living nematode
Panagrellus silusiae
is under the control of specific regions. Growth is regulated by the hindgut, and ecdysis by nerve cell bodies situated anterior to the nerve ring, and gonad development is under the control of the nerve ring. This latter event is presumably neuronally mediated, while the other events are under hormonal control.
Triple-Stranded Polynucleotide Helix Containing Only Purine Bases
Authors: Arnott Struther , Bond P. J.
Published: October 2006

The structure of the complex involving one polyadenylic acid and two polyinosinic acid chains has been determined by x-ray diffraction. The three coaxial, helical chains have conformations like conventional RNA double helices despite the absence of purine-pyrimidine pairing. Formation of hypoxanthine pairs in codon-anticodon interactions therefore requires only trivial changes in the conformation of a standard nucleotide. Evolution of the contemporary genetic code involving purine-pyrimidine complementarity from a primeval code with only adenine-hypoxanthine pairing would have been possible without major discontinuities in molecular geometry.
Cadmium: Mode of Occurrence in Illinois Coals
Authors: Gluskoter Harold J. , Lindahl Peter C.
Published: October 2006

The cadmium content of 23 Illinois coals ranges from less than 0.3 to 28 parts per million. The higher cadmium contents are found in coals that also have a relatively high zinc content. Cadmium occurs in these coals in solid solution, replacing zinc in the mineral sphalerite (ZnS). The ratios of zinc to cadmium in sphalerites are similar to the ratios of zinc to cadmium in the whole coals from which the sphalerites were separated.
Chemistry of Lunar Basalts with Very High Alumina Contents
Authors: Hubbard Norman J. , Rhodes J. Michael , Gast Paul W.
Published: October 2006

A chemically distinct group of lunar rocks with the trace element characteristics of basaltic lunar rocks is apparently ubiquitous on the lunar surface. Such rocks have been found at the Apollo 15, Apollo 16, and Luna 20 landing sites. They may be derived from the plains-forming material that has been designated Cayley Formation.
Rates of Late Cenozoic Uplift, Baldwin Hills, Los Angeles, California
Authors: Bandy Orville L. , Marincovich Louis
Published: October 2006

Radiocarbon ages for the marine late Pleistocene stratigraphic units of the Baldwin Hills are 36,200 ± 2,750 years and 28,450 ± 2,600 years, respectively, defining the termination of marine deposition in this area of the Los Angeles Basin at less than 28,000 years ago. Faunas of the older sample suggest that water depths were about 100 meters at the time of deposition. Shoaling of waters by deposition resulted in very shallow marine to nonmarine conditions about 28,000 years ago. The average rates of uplift for the past 36,000 years have been between 0.5 and 0.8 meter per 100 years.
Reactions of Singlet Oxygen with Pine Pollen
Authors: Dowty Betty , Laseter John L. , Griffin Gary W. , Politzer Ieva R. , Walkinshaw Charles H.
Published: October 2006

Exposure of pine pollen to singlet oxygen, generated in an aqueous environment, resulted in a decrease in the relative quantities of unsaturated fatty acids that could be recovered by solvent extraction of surface and near surface pollen lipids. The involvement of excited oxygen was confirmed by substitution of deuterium oxide for water, which led to a twofold greater decrease in the unsaturated acids. The potential environmental and biomedical implications of these observations are discussed in terms of this model system.
Collagen-Induced Platelet Aggregation: Involvement of an Active Glycopeptide Fragment (α1-CB5)
Authors: Katzman Richard L. , Kang Andrew H. , Beachey Edwin H.
Published: October 2006

It is widely held that the tertiary structure of collagen is essential for induction of platelet aggregation. However, we have found that the purified α1 chain prepared from denatured chick skin collagen aggregates platelets. This activity appears to be confined to a distinct region of the molecule representing less than 4 percent of the length of the α1 chain. Of all of the cyanogen bromide peptides of the α1 chain tested, only one (α1-CB5) was active. This glycopeptide, devoid of any ordered tertiary structure, contains only 36 amino acids and one residue of
O
-α-D-glucopyranosyl-(1 → 2)-
O
-β-D-galactopyranosyloxy-(1 → 5)-lysine (Glc-Gal-Hyl). Blocking experiments strongly suggest that the Glc-Gal-Hyl is one of the structural determinants involved in collagen-induced platelet aggregation.
Late Glacial and Postglacial Productivity Changes in a New England Pond
Authors: Whitehead Donald R. , Rochester Haydon , Rissing Steven W. , Douglass Claudia B. , Sheehan Mark C.
Published: October 2006

During the late glacial and postglacial the productivity of Berry Pond in Berkshire County, Massachusetts, underwent a number of significant oscillations. This is suggested by data on sedimentary chlorophyll degradation products, diatoms, and Cladocera. The productivity changes were. apparently controlled by changes in weathering, terrestrial vegetation in the watershed, litter production, and runoff. There are associated changes in cladoceran community structure.
Operant-Controlled Evoked Responses: Discrimination of Conditioned and Normally Occurring Components
Authors: Rosenfeld J. Peter , Hetzler Bruce E.
Published: October 2006

Rats were rewarded for signaling large and small sensory evoked components with appropriate bar presses. Most rats operantly generated large components and correctly signaled only these. Two rats correctly signaled successful and unsuccessful attempts to generate large waves. One rat discriminated component amplitudes without operantly attempting to generate specific wave types.
Glutamate Uptake by the Isolated Toad Brain
Authors: Shank Richard P. , Whiten Joycelyn T. , Baxter Claude F.
Published: October 2006

The isolated toad brain accumulates L-glutamate against strong concentration gradients until a tissue-to-medium concentration ratio of about 3000 : 1 is attained. The accumulated glutamate does not equilibrate with most of the endogenous tissue glutamate but is converted rapidly to glutamine and released into the medium. This mechanism may be involved in the preservation of low extracellular levels of cerebral glutamate.
Isolation of a Neurotropic Type C Virus
Authors: Officer J. Earle , Tecson Nora , Estes John D. , Fontanilla Evelyn , Rongey Robert W. , Gardner Murray B.
Published: October 2006

A neurogenic paralysis of the lower limb can be induced and serially transmitted in mice by a nontransforming type C virus strain that originated in an embryo of a wild mouse. The virus exerted a neurotropic effect on the anterior horn neurons.
Kinetosomes in Insect Epidermal Cells and Their Orientation with Respect to Cell Symmetry and Intercellular Patterning
Authors: Whitten Joan M.
Published: October 2006

Paired flagellar basal bodies or kinetosomes are described for tarsal, pulvillar, wing, proboscis, ptilinum, and tracheal epithelial cells in the fly
Sarcophaga bullata
. Evidence suggests that in every diploid epidermal cell their orientation is specific with respect to (i) cell symmetry and cuticular patterning, and (ii) intercellular positioning and polarity. Microtrichia may be homologous with the flagella of other organisms.
Biosynthesis of a Vasotocin-Like Peptide in Cell Cultures from Pineal Glands of Human Fetuses
Authors: Pavel S. , Dorcescu M. , Petrescu-Holban Ruxandra , Ghinea Elena
Published: October 2006

Cultured cells from pineal glands of human fetuses release into their media a substance that has antidiuretic and hydroosmotic activities. The ratio of these activities as well as their susceptibility to tryptic digestion, specific oxidative inactivation by tyrosinase, and reductive inactivation by sodium thioglycollate, indicates the presence of a basic peptide, presumably identical with arginine vasotocin. The total amount of this peptide released into the culture media during 38 days of incubation is about ten times greater than the amount contained in nonincubated pineal glands from fetuses of the same age, strongly suggesting that fetal ependymal cells from the pineal gland can synthesize in vitro a peptide similar to arginine vasotocin.
Dopa and Dopamine in Glusulase: Possible Artifact in Studies on Catecholamine Metabolism
Authors: Anton A. H. , Serrano A. , Tjandramaga T. B. , Goldberg L. I.
Published: October 2006

Relatively high concentrations of dopa and dopamine were found in Glusulase, an enzyme preparation widely used in studies on catecholamine metabolism. This contamination may be a source of error in some studies, particularly in those measuring the endogenous concentrations of these catechols and their metabolic products.
Limulus
Rhodopsin: Rapid Return of Transient Intermediates to the Thermally Stable State
Authors: Fein Alan , Cone Richard A.
Published: October 2006

Spectral transitions of rhodopsin in single cells of the
Limulus
ventral eye were observed both with flash photometry and by measuring the early receptor potential. Even with repetitive stimulus flashes the rhodopsin did not bleach; after each flash the spectral intermediates decayed rapidly to the initial thermally stable state. The pigment returns to the stable state in a time comparable with the duration of the late receptor potential.
Alkylpyrazine Alarm Pheromones in Ponerine Ants
Authors: Wheeler James W. , Blum Murray S.
Published: October 2006

The mandibular gland secretions of the ponerine ants
Odontomachus hastatus
,
O. clarus
, and
O. brunneus
contain alkylpyrazines. These compounds, 2,5-dimethyl-3-isopentylpyrazine in
O. hastatus
and
O. clarus
, and 2,6-dimethyl-3-pentyl-, -butyl-, -propyl-, and -ethyl-pyrazines in
O. brunneus
, have previously not been found as animal natural products. These compounds function as powerful releasers of alarm behavior for
Odontomachus
workers and are probably also utilized as defensive compounds.
Murine Leukemia: A Virus-Induced Autoimmune Disease?
Authors: Proffitt Max R. , Hirsch Martin S. , Black Paul H.
Published: October 2006

Thymocytes from mice carrying Moloney murine leukemia virus since birth are cytotoxic for normal syngeneic fibroblasts; they are much less cytotoxic for the same cells infected with this virus. The cytotoxic thymocytes appear to increase in number with age of the carrier mice and are present both during preleukemic and leukemic periods. These results suggest that lymphomas in carrier mice result from a sequence of events initiated by intrathymic destruction of normal cells by virus-infected cells, and culminating in the unrestricted proliferation of autoaggressive clones in the thymic cortex.
"Big" Growth Hormone Components from Human Plasma: Decreased Reactivity Demonstrated by Radioreceptor Assay
Authors: Gorden P. , Lesniak M. A. , Hendricks C. M. , Roth J.
Published: October 2006

Plasma as well as pituitary immunoreactive human growth hormone (HGH) comprises at least two discrete components which have been designated as "big" HGH and "little" HGH. Using a newly developed radioreceptor assay, which depends on the ability of a substance to compete with labeled HGH for binding sites on cultured human lymphocytes, we find that the big HGH component from both normal and acromegalic subjects has much less activity in the radioreceptor assay than in the radioimmunoassay, whereas the little HGH component has similar activity in both assays.
Ontogeny and Peripheralization of Thymic Lymphocytes
Authors: Turpen James B. , Volpe E. Peter , Cohen Nicholas
Published: October 2006

Reciprocal transplantation of undifferentiated thymic primordia between diploid and
triploid chromosomally marked frog embryos has revealed that thymic lymphocytes are
ontogenically derived from elements of the thymic primordium rather than from blood-borne
stem cells that migrated into the developing organ. Virtually all the lymphocytes in the
spleen, kidneys, and bone marrow of adult frogs are descendants of these original thymic
stem lymphocytes.
Alteration of Disc Formation in Photoreceptors of Rat Retina
Authors: Landis Dennis J. , Dudley Peter A. , Anderson Robert E.
Published: October 2006

Autoradiographic experiments demonstrate that the renewal process of the rod photoreceptors in the rat retina is altered during essential fatty acid deficiency. After the administration of tritiated amino acids, animals raised on a fat-free ration show no evidence of disc formation, while those raised on a normal ration show disc formation and renewal. The latter process is apparently dependent upon the availability of linoleic or linolenic (or both) fatty acids.
Mapping Human Autosomes: Assignment of the MN Locus to a Specific Segment in the Long Arm of Chromosome No. 2
Authors: German James , Chaganti R. S. K.
Published: October 2006

The locus for MN blood groups,
MN,
is tentatively assigned to a specific region near the centromere of the long arm of chromosome No. 2 on the basis of a demonstrable deletion of band 2q14 from a No. 2 chromosome in a boy previously reported to be hemizygous
(M/-)
at that locus.
Gas-Rich Meteorites: Possible Evidence for Origin on a Regolith
Authors: Macdougall D. , Rajan R. S. , Price P. B.
Published: October 2006

The asymmetry of irradiation features of grains in the Kapoeta and Fayetteville meteorites suggests irradiation on a regolith before meteorite formation. Chondrules and broken grains require approximately 10
4
years of irradiation time between formation or fracturing and compaction into the meteorite. Shock erasure of tracks from irradiated Kapoeta feldspars requires a severe shock event during or after meteorite formation.
Transplantation of Allogeneic Bone Marrow in Canine Cyclic Neutropenia
Authors: Dale David C. , Graw Robert G.
Published: October 2006

Transplantation of normal bone marrow cells to a gray collie dog with cyclic neutropenia resulted in normal granulocytopoiesis. The finding suggests that cyclic neutropenia occurs because the hematopoietic stem cells are defective. Because of the similarity of human and canine cyclic neutropenia, it also suggests that the human disease may be curable by marrow transplantation.
Antireceptor Antiserum Causes Specific Inhibition of Reactivity to Rat Histocompatibility Antigens
Authors: McKearn Thomas J.
Published: October 2006

The antigen receptor of lymphocytes destined to form antibody appears to have the characteristics of the immunoglobulin produced. Antibody directed against the combining region of this immunoglobulin should interact with the combining region of the cell receptor for the antigen. Purified Lewis rat alloantibody prepared against Brown Norway (BN) rat histocompatibility antigens was used to immunize L × BN F
1
hybrids. The resultant antiserum has antireceptor activity because (i) it yields precipitin lines in gel diffusion when reacted against the immunizing alloantibody; (ii) it inhibits the hemagglutinin antibody response of Lewis rats to BN histocompatibility antigens; and (iii) it inhibits the local graft-versus-host response of Lewis lymphoid cells against BN antigens. This suggests that antireceptor antibody may inhibit cell-mediated responses as well as antibody responses to histocompatibility antigens and may play a role in the regulation of immune responses to such antigens.
Neural Pathways from Thalamus Associated with Regulation of Aggressive Behavior
Authors: Bandler Richard J. , Flynn John P.
Published: October 2006

Small electrolytic lesions were made through electrodes in the thalamus of cats at sites where electrical stimulation elicited attack on a rat. Staining by modified Nauta reduced silver methods revealed that significant degeneration passed caudally from the lesions and entered the midbrain dorsal central gray region. Electrical stimulation of this dorsal midbrain region elicited attack on a rat, and destruction of this region suppressed the attack elicited by thalamic stimulation.
Tracheobronchial Epithelial Multinucleation in Malignant Disease
Authors: Chalon J. , Katz J. S. , Ramanathan S. , Ambiavagar M. , Orkin L. R.
Published: October 2006

Multinucleated tracheobronchial ciliated epithelial cells seen in smears from 112 patients suffering from a wide variety of malignant tumors were found to be 2.08 times more numerous than in a control group comparable in sex, age (decades), and smoking habit but without prediagnosed malignancies. The recognition of this phenomenon may lead to the development of a new test for the diagnosis of occult cancer and may open new pathways for investigation of cancer-host relationships.
Bacteriophage Structure: Determination of Head-Tail Symmetry Mismatch for
Caulobacter crescentus
Phage φCbK
Authors: Lake James A. , Leonard Kevin R.
Published: October 2006

Electron micrographs of negatively stained bacteriophage φCbK have been analyzed by Fourier methods. Computer-calculated Fourier transforms that contain phase as well as magnitude information have established fivefold rotational symmetry for the head and threefold rotational symmetry for the tail. These results indicate that a symmetry match is not necessarily required between separate structural components of a bacteriophage.
Amorphous Semiconductor Switching in Melanins
Authors: McGinness John , Corry Peter , Proctor Peter
Published: October 2006

Melanins produced synthetically and isolated from biological systems act as an amorphous semiconductor threshold switch. Switching occurs reversibly at potential gradients two to three orders of magnitude lower than reported for inorganic thin films, and comparable to gradients existing in some biological systems. Of a number of other biological materials tested, only cytochrome c acted similarly, but at the high potential gradients reported for thin film amorphous semiconductors.
Melting Relations of the Allende Meteorite
Authors: Seitz M. G. , Kushiro I.
Published: October 2006

The proportions of major oxides in the Allende carbonaceous chondrite after partial reduction are remarkably similar to those in possible mantle material of the earth. When heated, the Allende meteorite generates a sulfide melt (47 percent iron, 25 percent nickel, and 24 percent sulfur by weight), a ferrobasaltic melt, and olivine with or without pyroxene, over a wide pressure range (5 to 25 kilobars). The silicate melt contains more sodium and less titanium than lunar ferrobasalts. An aggregate of the Allende chondrite rich in calcium and aluminum produces silica-undersaturated, calcium-rich melt and spinel over a wide pressure and temperature range. From these studies, it is suggested that the earth's core contains significant amounts of both nickel and sulfur and that a 3 : 2 mixture of Allende bulk sample and calcium- and aluminum-rich aggregates is closer in major element abundances than either of these components to the average composition of the moon.
Calcification on an Unstable Substrate: Marginal Growth in the Mollusk
Pecten diegensis
Authors: Clark George R.
Published: October 2006

Observations of the growing margin of
Pecten diegensis
show that calcification can occur on an unstable substrate, although this initial shell material is quite disordered. Later growth on the inner surface of the disordered material soon becomes ordered, which suggests that the calcification process benefits from the stability of a mineralized substrate, but does not utilize the substrate as a physical or stereochemical template.
Inhibition of Neighboring Motoneurons in Conscious Control of Single Spinal Motoneurons
Authors: Smith H. McCord , Basmajian John V. , Vanderstoep Sandra F.
Published: October 2006

Multiple fine-wire electrodes were implanted in the biceps brachii of five subjects, and artificial electronic feedback was provided to subjects from only one electrode. By this technique, it was shown that neighboring units progressively stop firing as subjects concentrate on activating an isolated unit. The inhibition of neighboring spinal motoneurons in the same pool further indicates that selective inhibition is an automatic part of single motor-unit training.
Evidence that Enzyme Polymorphisms Are Selectively Neutral, but Blood Group Polymorphisms Are Not
Authors: Yamazaki Tsuneyuki , Maruyama Takeo
Published: October 2006

Data on enzyme polymorphism and blood group polymorphism were examined with special reference to molecular evolution, by using a statistic that depends on neither population structure nor other ecological factors. The data of the former are consistent with the hypothesis of neutral mutant and random genetic drift, whereas the latter are in accord with the hypothesis of balanced selection.
Site-Specific Cleavage of Human Chromosome 4 Mediated by Triple-Helix Formation
Authors: Strobel Scott A. , Doucette-Stamm Lynn A. , Riba Laura , Housman David E. , Dervan Peter B.
Published: October 2006

Direct physical isolation of specific DNA segments from the human genome is a necessary goal in human genetics. For testing whether triple-helix mediated enzymatic cleavage can liberate a specific segment of a human chromosome, the tip of human chromosome 4, which contains the entire candidate region for the Huntington's disease gene, was chosen as a target. A 16-base pyrimidine oligodeoxyribonucleotide was able to locate a 16-base pair purine target site within more than 10 gigabase pairs of genomic DNA and mediate the exact enzymatic cleavage at that site in more than 80 percent yield. The recognition motif is sufficiently generalizable that most cosmids should contain a sequence targetable by triple-helix formation. This method may facilitate the orchestrated dissection of human chromosomes from normal and affected individuals into megabase sized fragments and facilitate the isolation of candidate gene loci.
Lymphocyte Antigenicity Loss with Retention of Responsiveness
Authors: Opelz Gerhard , Terasaki Paul I.
Published: October 2006

During culturing at 22°C for more than 4 days, human peripheral blood lymphocytes lose their ability to stimulate allogeneic lymphocytes in mixed lymphocyte cultures. The cells retain their ability to respond to allogeneic lymphocytes or phytohemagglutinin for up to 10 days of culturing. The findings are relevant to reports on successful transplantation of cultured skin.
Global Trends in Total Atmospheric Ozone
Authors: London Julius , Kelley Jean
Published: October 2006

Analyses of the mean monthly global distributions of total ozone for the 13-year period from 1957 through 1970 reveal an upward trend of about 7.5 percent per decade in the Northern Hemisphere and about 2.5 percent per decade in the Southern Hemisphere. The increase seems to have started about March 1961 in the Northern Hemisphere and about September 1961 in the Southern Hemisphere. The cause of these trends is at present unknown.
Recent Developments in the Analysis of Toxic Elements
Authors: Lisk Donald J.
Published: October 2006

One may conclude that it is impractical to confine oneself to any one analytical method since ever more sensitive instrumentation continues to be produced. However, in certain methods such as anodic stripping voltammetry and flameless atomic absorption it may be background contamination from reagent impurities and surroundings rather than instrument sensitivity which controls the limits of element detection. The problem of contamination from dust or glassware is greatly magnified when the sample size becomes ever smaller. Air entering laboratories near highways may contain trace quantities of lead, cadmium, barium, antimony, and other elements from engine exhaust. Even plastic materials contacting the sample may be suspect as a source of contamination since specific metals may be used as catalysts in the synthesis of the plastic and traces may be retained in it. Certain elements may even be deliberately added to plastics during manufacture for identification purposes. Nondestructive methods such as neutron activation and x-ray techniques thus offer great advantages not only in time but in the elimination of impurities introduced during sample ashing. Future improvements in attainable limits of detection may arise largely from progress in the ultrapurification of reagents and "clean-room" techniques. Finally, the competence of the analyst is also vitally important in the skillful operation of modern complex analytical instrumentation and in the experienced evaluation of data.
Population Genetics in Forensic DNA Typing
Authors: Lewontin R. C. , Hartl Daniel L.
Published: October 2006

Variable number of tandem repeat (VNTR) sequences are used to link defendants with crimes by matching DNA patterns. The probative value of a match is often calculated by multiplying together the estimated frequencies with which each particular VNTR pattern occurs in a reference database. However, this method is liable to potentially serious errors because ethnic subgroups within major racial categories exhibit genetic differences that are maintained by endogamy. The multiplication procedure currently in use can be made scientifically valid only by extensive sampling of VNTR frequency distributions in a variety of ethnic groups, similar to the ethnic studies of various blood groups done in the past. Alternative approaches for dealing with subpopulation heterogeneity are discussed.
Woodruffia metabolica
: An Exception to the Rule of Desmodexy
Authors: Golder Thomas K.
Published: October 2006

Woodruffia metabolica
(Protozoa, Ciliophora) has a compound fiber on the left side of its ciliary rows composed of parallel, overlapping ribbons of kinetosome-based microtubules. No similar structure is found connecting the kinetosomes on the right side of the ciliary rows. This arrangement is in opposition to the rule of desmodexy.
Malignant Melanoma: Specific Immunity Induced by Bacillus Calmette-Gurin in BALB/c Mice
Authors: Faraci Robert P. , Schour Lionel
Published: October 2006

Previous treatment of BALB/c mice with bacillus Calmette-Gurin (BCG) will significantly protect them against intramuscular challenge of S-91 melanoma but not against a mammary carcinoma or a methylcholanthrene-induced sarcoma. Lymphocyte-mediated cytotoxicity studies correlate with in vivo data in showing that BCG-immune lymphocytes are specifically cytotoxic to S-91 melanoma target cells but not to the carcinoma or sarcoma target cells.
Modulation of the Copulatory Sequence of the Male Rat by a Schedule of Reinforcement
Authors: Silberberg Alan , Adler Norman
Published: October 2006

Copulating male rats were permitted a maximum of seven intromissions in which to ejaculate. This experimental constraint of the male rat's sexual behavior produced an increase in the number of sessions in which the male ejaculated before the seventh intromission. This species-specific behavior pattern is therefore susceptible to environmental conditioning.
Anemia in Domestic Cats: Effect on Hemoglobin Components and Whole Blood Oxygenation
Authors: Mauk A. G. , Whelan H. T. , Putz G. R. , Taketa F.
Published: October 2006

Phenylhydrazine-induced anemia in the domestic cat results in an increase in minor, high oxygen affinity hemoglobin B components and an accompanying decrease in the major, low affinity B component. This change is accompanied by an unusually large increase in erythrocytic adenosine triphosphate and 2,3-diphosphoglycerate, a slight decrease in the oxygen affinity of whole blood, and a large decrease in the Hill constant.
Absence of REM Rebound after Barbiturate Withdrawal
Authors: Feinberg I. , Hibi S. , Cavness C. , March J.
Published: October 2006

Administration of three different barbiturates reduced rapid eye movement (REM) sleep. Drug withdrawal led to a return to baseline REM values without significant overshoot. Similar results are observed with administration of benzodiazepines in pharmacologically equivalent dosages; therefore, a distinction between these two drug classes on the basis of withdrawal effects on the sleep electroencephalogram appears unwarranted. Further investigation is required to determine why high REM levels are sometimes associated with the withdrawal of sedative-hypnotic agents.
Genetic Variation in Coumarin Hydroxylase Activity in the Mouse (
Mus musculus
)
Authors: Wood A. W. , Conney A. H.
Published: October 2006

Basal and phenobarbital-induced rates of hepatic metabolism of coumarin to 7-hydroxycoumarin are markedly higher in DBA/2J mice than they are in the AKR/J, C57BL/6J, and C3H/HeJ strains. Intermediate coumarin hydroxylase activity in F
1
hybrids of mating between DBA/2J and the other three strains indicates an additive mode of inheritance.
Barley Stripe Mosaic Virions Associated with Spindle Microtubules
Authors: Mayhew D. E. , Carroll T. W.
Published: October 2006

Virions of barley stripe mosaic virus were observed attached to microtubules of the spindle apparatus. This phenomenon was found in barley cells undergoing meiosis and mitosis. The microtubules may be involved in the assembly and cell-to-cell transfer of the virus.