bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Adrenal Medullary Catecholamine Response to Hypoxia in Fetal Sheep
Authors: Cheung Cecilia Y.
Published: October 2006

Abstract: The present study was designed to investigate the direct response of fetal adrenomedullary cells to hypoxia, and the possible change in this responsiveness with maturation. Ovine fetal adrenomedullary cells, when exposed to 30 min of hypoxia induced by perfusing with Krebs–Henseleit solution equilibrated with 1% O2, released significantly greater amounts of total catecholamine into the perfusate, compared to basal conditions. After a 1‐h control period, a second 30‐min hypoxic episode stimulated a catecholamine response which was significantly smaller in magnitude than the first. Following the two hypoxic episodes, the cells were capable of responding to 50 mM KCl with a large increase in total catecholamine release. During the first hypoxic episode, the release of both norepinephrine and epinephrine was stimulated by equal magnitude. Fetal adrenomedullary cells obtained from fetuses at 100, 120, and 130 days gestation showed similar responsiveness to the same hypoxic stimulus, and these responses were not different from that observed in maternal adrenomedullary cells. On the contrary, responsiveness to KCl‐induced depolarization was greatest in cells obtained from fetuses at 130 days gestation when compared to that in the younger fetuses. This increased responsiveness to KCl was accompanied by a greater catecholamine store in the adrenal medulla of the fetuses at this gestational age. These results suggest that ovine fetal adrenomedullary cells can respond directly to hypoxia by releasing catecholamines. This direct responsiveness became desensitized after repeated exposure. Finally, a decrease in direct responsiveness to hypoxia associated with maturation could not be demonstrated.
Differential Ultrastructural Localization of Myelin Basic Protein, Myelin/Oligodendroglial Glycoprotein, and 2′,3′‐Cyclic Nucleotide 3′‐Phosphodiesterase in the CNS of Adult Rats
Authors: Brunner Christof , Lassmann Hans , Waehneldt Thomas V. , Matthieu Jean‐Marie , Linington Christopher
Published: October 2006

Abstract: In a light and electron microscopic immunocytochemical study we have examined the distribution of myelin basic protein (MBP), 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase (CNP), and myelin/oligodendroglial glycoprotein (MOG) within CNS myelin sheaths and oligodendrocytes of adult Sprague–Dawley rats. Ultrastructural immunocytochemistry allowed quantitative analysis of antigen density in different myelin and oligodendrocyte zones: MBP was detectable in high density over the whole myelin sheath, but not in regions of loops, somata, or the oligodendrocyte plasma membrane. CNP reactivity was highest at the myelin/axon interface, and found in lower concentration over the outer lamellae of myelin sheaths, at the cytoplasmic face of oligodendrocyte membranes, and throughout the compact myelin. MOG was preferentially detected at the extracellular surface of myelin sheaths and oligodendrocytes and in only low amounts in the lamellae of compacted myelin and the myelin/axon border zone. Our studies, thus, indicate further the presence of different molecular domains in compact myelin, which may be functionally relevant for the integrity and maintenance of the myelin sheath.
Antiproliferative Action of Benzodiazepines in Cultured Brain Cells Is Not Mediated Through the Peripheral‐Type Benzodiazepine Acceptor
Authors: Gorman Adrienne M. C. , O'Beirne Gerard B. , Regan Ciaran M. , Williams D. Clive
Published: October 2006

The benzodiazepines, Ro 5–4864, diazepam, clonazepam, and also PK‐11195, inhibited, at micromolar concentrations, the proliferation of rat C6 glioma and mouse neuro‐2A neuroblastoma cells in culture. The cells possessed high levels of “peripheral‐type” high‐affinity benzodiazepine binding sites as judged by binding assays and displacement potencies. However, the different potencies and specificities of compounds for the antiproliferative actions and binding affinities for the binding site suggest that the antiproliferative actions were not mediated through the peripheral‐type binding site. In support of this, these compounds have also been shown to inhibit proliferation of some nonneuronal cultured cell lines, e.g., mouse SP2/0‐Agl4 hybridoma and rat NCTC epithelial cells, which have no detectable high‐affinity peripheral‐type benzodiazepine binding sites.
Regulation of Cyclic AMP Formation in Cultures of Human Foetal Astrocytes by β2‐Adrenergic and Adenosine Receptors
Authors: Woods Mary D. , Ian Freshney R. , Ball Stephen G. , Vaughan Peter F. T.
Published: October 2006

Two cell cultures, NEP2 and NEM2, isolated from human foetal brain have been maintained through several passages and found to express some properties of astrocytes. Both cell cultures contain adenylate cyclase stimulated by catecholamines with a potency order of isoprenaline > adrenaline > salbutamol < noradrenaline, which is consistent with the presence of β2‐adrenergic receptors. This study reports that the β2‐adrenergic‐selective antagonist ICI 118,551 is ˜ 1,000 times more potent at inhibiting isoprenaline stimulation of cyclic AMP (cAMP) formation in both NEP2 and NEM2 than the β1adrenergic‐selective antagonist practolol. This observation confirms the presence of β2‐adrenergic receptors in these cell cultures. The formation of cAMP in NEP2 is also stimulated by 5′‐(N‐ethylcarboxamido)adenosine (NECA) more potently than by either adenosine or N6‐(L‐phenylisopropyl)adenosine (L‐PIA), which suggests that this foetal astrocyte expresses adenosine A2 receptors. Further more, L‐PIA and NECA inhibit isoprenaline stimulation of cAMP formation, a result suggesting the presence of adenosine A1 receptors on NEP2. The presence of A1 receptors is confirmed by the observation that the A1‐selective antagonist 8‐cyclopentyl‐1,3‐dipropylxanthine reverses the inhibition of isoprenaline stimulation of cAMP formation by L‐PIA and NECA. Additional evidence that NEP2 expresses adenosine receptors linked to the adenylate cyclase‐inhibitory GTP‐binding protein is provided by the finding that pretreatment of these cells with pertussis toxin reverses the adenosine inhibition of cAMP formation stimulated by either isoprenaline or forskolin.
Peptidasic Activities Associated with Acetylcholinesterase Are Due to Contaminating Enzymes
Authors: Checler Frédéric , Vincent Jean‐Pierre
Published: October 2006

The esterasic and peptidasic activities of two different sources of acetylcholinesterase purified from electric eel were examined. Hydrolyses of leucine‐enkephalin and neurotensin indicated that both sources exhibited exopepti‐dasic and tryptic‐like activities. However, the enzyme preparation which appeared 10‐fold enriched with regard to the esterasic activity was found to display a 50‐ and 185‐fold lower tryptic‐like and exopeptidasic function, respectively. This lack of parallelism in the enrichment of the various activities seemed to indicate that they were not co‐purified. Immunoprecipitation experiments performed with monoclonal antibodies directed towards the catalytic subunit of globular or asymmetric forms of electric eel acetylcholinesterase allowed the physical dissociation of esterasic and peptidasic functions and therefore confirmed that the ability of acetylcholinesterase to hydrolyze various neuropeptides was likely due to contaminating peptidases.
Circadian Regulation of Melatonin in the Retina of Xenopus laevis: Limitation by Serotonin Availability
Authors: Cahill Gregory M. , Besharse Joseph C.
Published: October 2006

Treatments expected to increase retinal serotonin levels were found to stimulate melatonin production by cultured eyecups from Xenopus laevis. The monoamine oxidase inhibitor pargyline (100 μM) caused a sixfold increase in melatonin release, and the serotonin precursor 5‐hydroxy‐L‐tryptophan (100 μM) caused a 70‐fold increase. Both acted synergistically with eserine, an inhibitor of melatonin deacetylation in the retina. The effect of 5‐hydroxytryptophan was dose dependent, with effects increasing from 1 to 100 μM. Increasing the tryptophan level in the culture medium had no effect on melatonin release. These results indicate that the rate‐limiting step in retinal melatonin synthesis is 5‐hydroxylation of tryptophan. Melatonin released from individual eyecups in superfusion culture in constant darkness with and without added 5‐hydroxy‐L‐tryptophan was monitored over a 5‐day period. Control eyecups released low levels of melatonin, with circadian rhythmicity persisting for 1–3 days. With 5‐hydroxy‐L‐tryptophan added, melatonin levels were elevated 10–20‐fold at all times, and rhythmicity was apparent for as long as five cycles. This provides a model system for studies of the circadian clock in the eye.
Clinical correlates of oral health‐related quality of life: evidence from a national sample of British older people
Authors: Tsakos Georgios , Steele James G. , Marcenes Wagner , Walls Angus W. G. , Sheiham Aubrey
Published: October 2006

This study investigated the relationships between an oral health‐related quality of life (OHRQoL) indicator and specific clinical dental measures, in a national representative sample of the British older population. A random subsample was drawn from the free‐living sample of the National Diet and Nutrition Survey (people aged ≥ 65 yr). This subsample consisted of 407 dentate and 346 edentate participants, who were clinically examined and interviewed. The OHRQoL was assessed through the Oral Impacts on Daily Performance (OIDP) indicator. After adjusting for age, gender, and education, dentate subjects with up to 8 occluding pairs of teeth were 2.66 [95% confidence interval (CI): 1.08, 6.51) times, and those with up to 2 anterior occluding pairs were 3.00 (95% CI: 1.55, 5.81) times, more likely to report oral impacts when compared with those having more occluding pairs of teeth. Edentate participants with inadequate denture adaptation were 1.92 (95% CI: 1.04, 3.53) times, and subjects with inadequate denture retention were 2.04 (95% CI: 1.13, 3.69) times, more likely to report oral impacts than the remaining edentate sample in each case. OHRQoL in older British people is significantly related to the number of occluding pairs of natural teeth among the dentate and denture quality among the edentate.
Multiple Sclerosis and High Incidence of a B Lymphocyte Antigen
Authors: Terasaki Paul I. , Park Min Sik , Opelz Gerhard , Ting Alan
Published: October 2006

Multiple sclerosis patients were tested for six new antigens present on human B lymphocytes. The group 4 specificity occurred in 83.9 percent of the 56 patients as compared to 32.5 percent in 72 healthy controls (
P
< .003). The antiserums defining the five other B lymphocyte specificities reacted at a lower frequency to B cells from multiple sclerosis patients, showing that increased reactivity to group 4 antiserums was specific. Linkage of a hypothesized multiple sclerosis susceptibility gene with certain haplotypes of HLA-A3, HLA-B7, HLA-DW2, and the new B group 4 can be inferred.
F Factor Promotes Turnover of Stable RNA in
Escherichia coli
Authors: Onishi Yoshinari
Published: October 2006

Male bacteria that contain an
srnA
-
mutant allele degrade their "stable" RNA massively after RNA synthesis is blocked at 42°C; a normal F
-
female strain shows no such RNA breakdown unless both the
srnA
-
allele and maleness (F factor) are introduced.
The Neural Crest and the Origin of the Insulin-Producing and Other Gastrointestinal Hormone-Producing Cells
Authors: Pictet Raymond L. , Rall Leslie B. , Phelps Patricia , Rutter William J.
Published: October 2006

It has been proposed that the endocrine cells of the digestive tract derive from the neuroectoderm (neural crest). To test this hypothesis we removed the entire ectoderm, the precursor of the neural crest, of embryonic rats prior to the formation of the neural crest and cultured the mesoendoderm for 11 days. In every case where a pancreas developed, insulin was detected or B cells were observed. Thus, a neural crest origin for these cells is eliminated.
Nuclear Magnetic Resonance of Rotational Mobility of Mouse Hemoglobin Labeled with [2-
13
C]Histidine
Authors: London R. E. , Gregg C. T. , Matwiyoff N. A.
Published: October 2006

Carbon-13 nuclear magnetic resonance studies were made on mouse hemoglobin specifically labeled at the C-2 histidine position. Measurement of the spin lattice relaxation times of the label before and after hemolysis of the erythrocytes provides information on the intracellular fluid viscosities.
Flavonoids as Inhibitors of Lens Aldose Reductase
Authors: Varma S. D. , Mikuni I. , Kinoshita J. H.
Published: October 2006

Flavonoids are effective inhibitors of lens aldose reductase. Quercetin, quercitrin, and myricitrin are significantly more potent than the previously known aldose reductase inhibitors. The inhibitory activity is of the noncompetitive type. In addition, quercitrin effectively blocks polyol accumulation in intact rat lenses incubated in medium containing high concentration of sugars.
Iridium Profile for 10 Million Years Across the Cretaceous-Tertiary Boundary at Gubbio (Italy)
Authors: Alvarez Walter , Asaro Frank , Montanari Alessandro
Published: October 2006

The iridium anomaly at the Cretaceous-Tertiary (KT) boundary was discovered in the pelagic limestone sequence at Gubbio on the basis of 12 samples analyzed by neutron activation analysis (NAA) and was interpreted as indicating impact of a large extraterrestrial object at exactly the time of the KT mass extinction. Continuing controversy over the shape of the Ir profile at the Gubbio KT boundary and its interpretation called for a more detailed follow-up study. Analysis of a 57-meter-thick, 10-million-year-old part of the Gubbio sequence using improved NAA techniques revealed that there is only one Ir anomaly at the KT boundary, but this anomaly shows an intricate fine structure, the origin of which cannot yet be entirely explained. The KT Ir anomaly peaks in a 1-centimeter-thick clay layer, where the average Ir concentration is 3000 parts per trillion (ppt); this peak is flanked by tails with Ir concentrations of 20 to 80 ppt that rise above a background of 12 to 13 ppt. The fine structure of the tails is probably due in part to lateral reworking, diffusion, burrowing, and perhaps Milankovitch cyclicity.
Anomalous Myopias and the Intermediate Dark Focus of Accommodation
Authors: Leibowitz H. W. , Owens D. A.
Published: October 2006

The dark focus of accommodation for an individual observer correlates highly with the magnitude of night, empty field, and instrument myopia. These anomalous myopias are interpreted as resulting from the passive return of accommodation to an individually determined intermediate dark focus when the stimulus for accommodation is degraded or absent, or when the need for accommodation is eliminated.
Stability and Absorption Spectrum of Malononitrile
Authors: Mendelson J. , Mendelson J. H. , Fax B. J. , Grenell R. G.
Published: October 2006

1) Spectra in the ultraviolet and visible regions have been obtained on samples of malononitrile under different conditions. The samples were manufactured by several companies in America and Sweden.

2) The spectral analysis has demonstrated that the compound used by Hydén and Hartelius is not the same as that employed by American investigators. If, however, an aqueous solution of the American product is allowed to stand at room temperature for a long enough time, it develops the same spectral characteristics as the Swedish solution.

3) Future studies will concern themselves with attempts to identify, the active substance and to examine its effect on neuronal nucleoproteins.
Mass Recruitment by Army Ants
Authors: Chadab Ruth , Rettenmeyer Carl W.
Published: October 2006

A single army ant (Ecitoninae) can attract and direct scores of workers to prey by means of a chemical trail and momentary contact between the recruiter and workers on a raid column. Recruited workers, in turn, attract more ants, resulting in a continuous stream of recruits. While the recruitment mechanism is basically similar, the speed and the number of ants recruited are greater for army ants than for other ants.
Visual Adaptation: Effects of Externally Applied Retinal on the Light-Adapted, Isolated Skate Retina
Authors: Pepperberg David R. , Lurie Mark , Brown Paul K. , Dowling John E.
Published: October 2006

Incubation with externally applied 11-
cis
retinal induces a marked increase of visual sensitivity within partially bleached skate photoreceptors. This activity of 11-
cis
retinal is duplicated by 9-
cis
retinal, but not by all-trans retinal. The sensitization of photoreceptors promoted by 11-
cis
and 9-
cis
retinal is accompanied by the formation of rhodopsin and isorhodopsin, respectively.
Meaning, Memory Structure, and Mental Processes
Authors: Meyer David E. , Schvaneveldt Roger W.
Published: October 2006

Although people experience little difficulty in recognizing printed words and comprehending sentences, they cannot do it instantaneously. Experimental psychologists have recently measured the speed of these mental processes by applying a reaction-time method. The method provides new data concerning the organization and retrieval of familiar semantic information in human memory.

It has been found that close relations between the meanings of words help people to recognize and pronounce the words faster, especially when the words are hard to see because of visual distortions. Close relations between word meanings also facilitate the comprehension of some sentences, as indicated by how long a person takes to decide whether the sentences are true or false. The facilitation is not universal, however. When the relation between the meanings of two words must be analyzed carefully, their proximity may actually inhibit mental processing.

These results, along with additional findings, support the hypothesis that human memory includes a semantic network that represents various categories of objects at distinct locations linked to specify their relations with each other. The memory structure probably influences a number of different mental processes that use it. One possible access route to the network is through a set of detectors designed to accumulate sensory information and signal the presence of particular words. There also appear to be processes for searching and comparing pieces of knowledge after a person finds the memory locations of designated categories. Further research using the reaction-time method may provide a more detailed inventory of what facts are retrieved directly from memory and what are computed from other stored information .
Gating Currents Associated with Sodium and Calcium Currents in an
Aplysia
Neuron
Authors: Adams David J. , Gage Peter W.
Published: October 2006

In a voltage-clamped aplysia neuron (R
15
), depolarization beyond -30 millivolts produces an inward sodium current. Depolarization beyond -10 millivolts produces an additional inward calcium current with slower kinetics than the sodium current. When these ionic currents have been suppressed and capacitive currents subtracted out, a small outward displacement current can be seen with depolarizations beyond -30 millivolts. An additional, slower displacement current is seen with depolarizations beyond -10 millivolts. The currents have an exponential decay with an increase in rate per 10°C increase in temperature of about 3 and are thought to be sodium and calcium gating currents.
Sexual Agglutination of Heterothallic Yeasts in Diverse Taxonomic Areas
Authors: Wickerham Lynferd J.
Published: October 2006

Species in four genera of yeasts produce mating types that clump when brought together in liquid or on solid media. All species of a phylogenetic line of
Saccharomyces
are sexually agglutinative. Unisexuals of the latter species are believed to have from one to four sets of chromosomes, whereas bisexuals are believed to have from two to eight sets.
Phthalate Dioxygenase Reductase: a Modular Structure for Electron Transfer from Pyridine Nucleotides to [2Fe-2S]
Authors: Correll Carl C. , Batie Christopher J. , Ballou David P. , Ludwig Martha L.
Published: October 2006

Phthalate dioxygenase reductase (PDR) is a prototypical iron-sulfur flavoprotein (36 kilodaltons) that utilizes flavin mononucleotide (FMN) to mediate electron transfer from the two-electron donor, reduced nicotinamide adenine nucleotide (NADH), to the one-electron acceptor, [2Fe-2S]. The crystal structure of oxidized PDR from
Pseudomonas cepacia
has been analyzed at 2.0 angstrom resolution resolution; reduced PDR and pyridine nucleotide complexes have been analyzed at 2.7 angstrom resolution. NADH, FMN, and the [2Fe-2S] cluster, bound to distinct domains, are brought together near a central cleft in the molecule, with only 4.9 angstroms separating the flavin 8-methyl and a cysteine sulfur ligated to iron. The domains that bind FMN and [2Fe-2S] are packed so that the flavin ring and the plane of the [2Fe-2S] core are approximately perpendicular. The [2Fe-2S] group is bound by four cysteines in a site resembling that in plant ferredoxins, but its redox potential (-174 millivolts at pH 7.0) is much higher than the potentials of plant ferredoxins. Structural and sequence similarities assign PDR to a distinct family of flavoprotein reductases, all related to ferredoxin NADP
+
-reductase.
Artificial Neuron
Authors: Harmon L. D.
Published: October 2006

An electronic model is described for simulating many of the gross operational functions which are believed to hold for living nerve cells. Synaptic growth is not included. Despite difficulties in drawing very rigorous analogies between the biological cell and its model, a sufficient number of rough similarities exist to make systemic experimentation interesting. Several approaches are mentioned.
Pipecolic Acid in Leaves of Strawberry Plant as Influenced by Treatments Affecting Growth
Authors: Yatsu Lawrence , Boynton Damon
Published: October 2006

Growth inhibition due to maleic hydrazide spray or to an unsatisfied chilling requirement caused young fully expanded leaves of the strawberry to accumulate pipecolic acid to a very striking degree. It is postulated that the accumulation resulted from blockage in normal metabolic conversion to other intermediary nitrogenous compounds.
Fusion of Complex Flicker
Authors: Levinson John
Published: October 2006

Brown and Forsyth have recently performed a flicker-fusion experiment showing clearly that there is more to flicker than meets the eye. This report presents an analysis of their results which indicates the likelihood that at fusion threshold all but one of the Fourier components of their presentation are imperceptible.
Daily Light Sensitivity Rhythm in a Rodent
Authors: De Coursey Patricia J.
Published: October 2006

Single 10-minute light periods can cause a phase shift in the rhythm of the daily locomotor activity of flying squirrels otherwise maintained in constant darkness. A daily rhythm of sensitivity to these standard light periods was found.
Acyl N → O Shift in Poly-DL-Serine
Authors: Fasman Gerald D.
Published: October 2006

It has been demonstrated that concentrated sulfuric acid causes the polypeptide, poly-DL-serine (MW≈5000), to rearrange to the polyester, to the extent of 70 percent of the original number of amide bonds. The remaining hydroxyls of the serine residues become sulfonated.
Polymerase II Promoter Activation: Closed Complex Formation and ATP-Driven Start Site Opening
Authors: Wang Weidong , Carey Michael , Gralla Jay D.
Published: October 2006

Studies on bacterial RNA polymerases have divided the initiation pathway into three steps, namely (i) promoter binding to form the closed complex; (ii) DNA melting to form an open complex, and (iii) messenger RNA initiation. Potassium permanganate was used to detect DNA melting by mammalian RNA polymerase II in vitro. Closed complexes formed in a rate-limiting step that was stimulated by the activator GAL4-VP16. Adenosine triphosphate was then hydrolyzed to rapidly melt the DNA within the closed complex to form an open complex. Addition of nucleoside triphosphates resulted in the melted bubble moving away from the start site, completing initiation.
Peptides Presented to the Immune System by the Murine Class II Major Histocompatibility Complex Molecule I-A
d
Authors: Hunt Donald F. , Michel Hanspeter , Dickinson Tracey A. , Shabanowitz Jeffrey , Cox Andrea L. , Sakaguchi Kazuyasu , Appella Ettore , Grey Howard M. , Sette Alessandro
Published: October 2006

Between 650 and 2000 different peptides are associated with the major histocompatibility complex class II molecule I-A
d
. Sequences for nine of these were obtained by a combination of automated Edman degradation and tandem mass spectrometry. All of the peptides are derived from secretory or integral membrane proteins that are synthesized by the antigen-presenting cell itself. Peptides were 16 to 18 residues long, had ragged NH
2
- and COOH-termini, and contained a six-residue binding motif that was variably placed within the peptide chain. Binding data on truncated peptides suggest that the peptide binding groove on class II molecules can be open at both ends.
Arizona's Oldest Cornfield
Authors: Martin Paul S. , Schoenwetter James
Published: October 2006

Flood-plain alluvium at the Cienega site, San Carlos Indian Reservation, central Arizona, contains two preceramic and one ceramic cultural horizon. Pollen of
Zea mays
appears in each, substantiating previous early records of agriculture in the American Southwest. Prehistoric cultivation extended through at least 2000 years, ending in the late 15th century.
Preparation of Monolayer Cell Cultures from Tissues of Some Lower Vertebrates
Authors: Wolf Ken , Quimby M. C. , Pyle E. A. , Dexter R. P.
Published: October 2006

Cold trypsin dispersion at
p
H 7.2 was used to obtain cultivable cells and cell groups from tissues of six species of fresh-water bony fishes, a frog, and a turtle. The cells readily attached to glass and were capable of at least limited, and in some cases extended, division in media consisting of commercially available components.
Faunal Remains on an Antarctic Ice Shelf
Authors: Swithinbank Charles W. M. , Darby David G. , Wohlschlag Donald E.
Published: October 2006

Fishes and benthic invertebrates discovered frozen
in situ
and exposed at the ablation surface of the McMurdo ice shelf provide evidence both for the occurrence of a fauna, including large fishes, under the permanent ice shelf and for Debenham's hypothesis of the nourishment of an ice shelf by the freezing of sea water on its bottom.
Giant Desiccation Fissures on the Black Rock and Smoke Creek Deserts, Nevada
Authors: Willden Ronald , Mabey Don R.
Published: October 2006

Open fissures, from 100 to several hundred feet apart, that have produced polygonal patterns on the Black Rock Desert, Nevada, are believed to be giant desiccation cracks resulting from a secular trend toward aridity in the last few decades. Similar features on the Smoke Creek Desert probably have the same origin.
Alternation as Function of Preliminary Training and Type of Deprivation
Authors: Hellyer Sidney , Straughan James H.
Published: October 2006

Laboratory rats trained upon a table top with randomly positioned reinforcement containers showed significantly a greater tendency to alternate in a Y-maze than animals trained on a straight runway. The type of deprivation, either food or water, did not have an effect. The differences in alternation disappeared with repeated trials on the Y-maze.
Chemotaxis of Zoospores for Root Exudates
Authors: Zentmyer George A.
Published: October 2006

A chemotactic response of the zoospores of a soil-inhabiting plant pathogenic fungus,
Phytophthora cinnamomi,
for roots of avocado seedlings was observed. The chemotaxis of the zoospores and chemotropy of their germ tubes were directly related to infection and disease production. Indications were obtained of specificity of the pathogen-attracting root exudate, and interesting implications are evident with regard to mechanisms of invasion and pathogenicity, and to disease resistance.
Discharge Patterns of Neurons in Cochlear Nucleus
Authors: Grossman R. G. , Viernstein L. J.
Published: October 2006

Patterns of discharge in slowly adapting, spontaneously discharging neurons of the cochlear nucleus were studied. A technique for analyzing the distribution of intervals between discharges of neurons is described. The response to a steady tone generally was an irregularly spaced train of impulses. In the majority of cells examined, the intervals between discharges were distributed exponentially. The mean interval and standard deviation of the distributions decreased as the level of afferent excitation was increased, but the modal value of the distribution was unchanged.
Infectious Nucleic Acids, a New Dimension in Virology
Authors: Herriott Roger M.
Published: October 2006

Viral nucleic acids have been found to be infectious for tissues and animals, yet are nonantigenic and resistant to antibodies against whole virus. Other unique properties, such as their host range and their susceptibility to nuclease action, render them a wholly new dimension to be reckoned with in virology.

These properties may explain a number of conditions which at present are considered anomalous. The release from infected tissues of even a small proportion of total virus as free nucleic acid could, in an otherwise immune individual, lead to a low level of infection which would, perhaps, explain permanent immunity. If the proportion of nucleic acid is higher, or if the nucleic acid is resistant to nucleases because of an inert envelope, such conditions as "carrier" states—that is, viremias with or without antibodies—are possible.

Note added in proof:
The recent article by J. D. Ebert and F. H. Wilt came to my attention after the present article was written. Ebert and Wilt's excellent article indicates the impact of the newer knowledge of viral nucleic acids on the ideas developing in the field of embryology.
Stabilization of Behavior and Prolonged Exposure to Delayed Auditory Feedback
Authors: Goldiamond Israel , Atkinson Chester J. , Bilger Robert C.
Published: October 2006

The disruption of fluent verbal behavior found under delayed feedback is replaced by stable patterns when presentation is prolonged. Experimental analysis suggests that the later patterns involve the reinstatement of control by stimuli in whose presence the behavior was originally established.
Glass Electrodes Sensitive to Divalent Cations
Authors: Garrels R. M. , Sato M. , Thompson M. E. , Truesdell A. H.
Published: October 2006

Glass electrodes suitable for measurement of divalent cations have been made and tested. Empirical and theoretical electrode equations have been presented to describe electrode behavior in a variety of aqueous solutions. Most electrodes show response interpretable as showing nearly ideal solid-solution behavior of the cations in the glass surface. The electrodes should be useful in the measurement of divalent-cation activities in natural waters and biological fluids, and useful in general analytical chemistry.
Zone Melting
Authors: Pfann W. G.
Published: October 2006

So far, most work in the field of zone melting has been done on a small scale, use of heavier than 100-pound ingots of certain metals notwithstanding. However, there is no basic reason why tons rather than pounds cannot be treated. Continuous refiners have been designed and operated, and a suitable design theory exists.
On the Use of -tropin or -trophin in Connection with Anterior Pituitary Hormones
Authors: Stewart Josephine , Li Choh Hao
Published: October 2006

The divergent usage that has persisted in the literature in connection with the terminology of anterior pituitary hormones is discussed, and the reasons for proposing the acceptance of
-tropins
and
tropic hormones
for standard use are outlined.
Beta Brain Waves as an Index of Alertness
Authors: Dustman Robert E. , Boswell Reed S. , Porter Paul B.
Published: October 2006

Reaction times of human subjects are reliably shorter when the signal to respond is given during spontaneous low voltage, fast (beta) brain waves than they are when the signal is given during spontaneous alpha waves. The mean difference of 12 milliseconds is, however, trivial in comparison to the advantage to be expected from forewarning.
Conditioning of Induced Electroencephalographic Sleep Patterns in the Cat
Authors: Wyrwicka W. , Sterman M. B. , Clemente C. D.
Published: October 2006

Stimulation of the basal forebrain synchronizing area of the cat induces the behavioral and electroencephalographic manifestations of sleep. By pairing such stimulation with a neutral auditory stimulus we were able to evoke electroencephalographic synchronization and sleep preparatory behavior to the presentation of a tone, and to temporal factors associated with the conditioning procedure.
Manifestations of "Activated" Sleep in the Rat
Authors: Swisher John E.
Published: October 2006

A sleep phase similar to feline "activated" sleep was found to occur regularly in normally sleeping rats. However, at these times the electroencephalogram differed from the waking or "activated" pattern in being dominated by 6- to 8-per-second waves. Instead of assuming a very relaxed posture, as cats in "activated" sleep do, the rats tended to undergo shifts in muscle tone, occasionally of considerable magnitude.
Spontaneous Electrical Activity of
Dionaea muscipula
Authors: Balotin N. Malcolm , DiPalma Joseph R.
Published: October 2006

Instillation of four to six drops of 3-percent saline in the leaf trap of
Dionaea muscipula
Ellis causes the appearance of a series of spontaneous action potentials. Mechanical stimulation of the sensitive leaf hair elicits only a single response. Immersion in 3-percent, but not in 1-percent, saline effects a loss of weight in
Dionaea
but not in the leaves of gardenia or geranium.
Inactivation of the p34

cdc2

-Cyclin B Complex by the Human WEE1 Tyrosine Kinase
Authors: Parker Laura L. , Piwnica-Worms Helen
Published: October 2006

Entry into mitosis in
Schizosaccharomyces pombe
is negatively regulated by the
wee1
+
gene, which encodes a protein kinase with serine-, theonine-, and tyrosine-phosphorylating activities. The
wee1
+
kinase negatively regulates mitosis by phosphorylating p34

cdc2

on tyrosine 15, thereby inactivating the p34

cdc2

-cyclin B complex. The human homolog of the
wee1
+
gene (
WEE1Hu
) was overproduced in bacteria and assayed in an in vitro system. Unlike its fission yeast homolog, the product of the
WEE1Hu
gene encoded a tyrosine-specific protein kinase. The human WEE1 kinase phosphorylated the p34

cdc2

-cyclin B complex on tyrosine 15 but not on threonine 14 in vitro and inactivated the p34

cdc2

-cyclin B kinase. This inhibition was reversed by the human Cdc25C protein, which catalyzed the dephosphorylation of p34

cdc2

. These results indicate that the product of the
WEE1Hu
gene directly regulates the p34

cdc2

-cyclin B complex in human cells and that a kinase other than that encoded by
WEE1Hu
phosphorylates p34

cdc2

on threonine 14.
Distress Call of the Bottlenose Dolphin: Stimuli and Evoked Behavioral Responses
Authors: Lilly John C.
Published: October 2006

Analysis of the many different vocal productions of pairs of bottlenose dolphins (
Tursiops truncatus
Montagu) and the related behavior patterns shows that one pair of specific short (0.2 to 0.6 second) whistles was consistently stimulated by physical distress. This call stimulated nearby animals to push the head of the distressed animal to the surface to breathe. After the animal breathed, a vocal exchange preceded other forms of aid.
Selective Sensitivity to Direction of Movement in Ganglion Cells of the Rabbit Retina
Authors: Barlow Horace B. , Hill Richard M.
Published: October 2006

Among the ganglion cells in the rabbit's retina there is a class that responds to movement of a stimulus in one direction, and does not respond to movement in the opposite direction. The same directional selectivity holds over the whole receptive field of one such cell, but the selected direction differs in different cells. The discharge is almost uninfluenced by the intensity of the stimulus spot, and the response occurs for the same direction of movement when a black spot is substituted for a light spot.
Stratigraphy of Beds I through IV, Olduvai Gorge, Tanganyika
Authors: Hay Richard L.
Published: October 2006

Bed I at Olduvai Gorge is a conformable sequence of lava flows and varied sedimentary deposits that extend upward from a welded tuff overlying the Precambrian basement to the top of a widespread marker bed. Bed II is a sequence of lacustrine clays and laterally equivalent fluvial, eolian, and pyroclastic deposits. Bed III is made up of alluvial deposits and a laterally equivalent assemblage of fluvial, lacustrine, and eolian beds. Bed IV can be subdivided into a lower unit of fluvial clays, sandstones, and conglomerates, and an upper unit of eolian tuffs. The climate was relatively dry throughout much of the time that these beds were deposited, and semidesert or desert conditions may have prevailed at least twice. Tectonic movement seems to have taken place between the deposition of Beds III and IV.
Intracranial Self-Stimulation in Man
Authors: Bishop M. P. , Elder S. Thomas , Heath Robert G.
Published: October 2006

Intracranial self-stimulation techniques, modified for use with neuropsychiatric patients, provide data suggestive of positive and negative reinforcing properties of brief electrical stimulation to various subcortical structures of the human brain.
Coesite and Stishovite: Stepwise Reversal Transformations
Authors: Dachille Frank , Zeto Robert J. , Roy Rustum
Published: October 2006

Very marked differences in the metastable persistence of coesite and stishovite have been demonstrated; the former possibly persists indefinitely below 1000°C at 1 atmosphere "dry," and the latter completely decomposes in minutes above 500° to 600°C to an amorphous or short range order phase. Quartz was grown (metastably) at temperatures well above its stability field from both coesite and stishovite, possibly by way of a short range order phase. The absence of stishovite in meteor-impact craters cannot be taken as evidence that it was not formed. If it has "reversed" in normal natural environments the product would almost certainly be a short range order phase or derivative.
Suppression of the Development of Female Mating Behavior by Estrogen Administered in Infancy
Authors: Whalen Richard E. , Nadler Ronald D.
Published: October 2006

The administration of estradiol benzoate subcutaneously to 4-day-old female rats resulted in reduced mating in response to estrogen and progesterone in adulthood.
Melatonin, a Pineal Substance: Effect on the Rat Ovary
Authors: Wurtman Richard J. , Axelrod Julius , Chu Elizabeth W.
Published: October 2006

Daily injection of microgram amounts of melatonin in rats decreased the incidence of estrus and reduced ovarian weight. Circulating melatonin was selectively taken up and retained by the ovary and pineal gland; this effect was reduced by exposure of rats to constant light. A single injection of melatonin lowered the incidence of estrus among rats exposed to constant light.
Fear and Pain: Their Effect on Self-Injection of Amobarbital Sodium by Rats
Authors: Davis John D. , Miller Neal E.
Published: October 2006

Rats receiving occasional brief electric shocks pressed a bar, which caused them to be injected with amobarbital sodium, more frequently than the control rats to which they were yoked and which were injected when their partners pressed but whose own bar activated only a recorder. This differential effect was not shown by pairs run without shocks.
Release of Alzheimer Amyloid Precursor Derivatives Stimulated by Activation of Muscarinic Acetylcholine Receptors
Authors: Nitsch Roger M. , Slack Barbara E. , Wurtman Richard J. , Growdon John H.
Published: October 2006

Altered processing of the amyloid precursor protein (APP) is a central event in the formation of amyloid deposits in the brains of individuals with Alzheimer's disease. To investigate whether cellular APP processing is controlled by cell-surface neurotransmitter receptors, human embryonic kidney (293) cell lines were transfected with the genes for human brain muscarinic acetylcholine receptors. Stimulation of m1 and m3 receptor subtypes with carbachol increased the basal release of APP derivatives within minutes of treatment, indicating that preexisting APP is released in response to receptor activation. Receptor-activated APP release was blocked by staurosporine, suggesting that protein kinases mediate neurotransmitter receptor-controlled APP processing.
Hemoglobin-AGE: A Circulating Marker of Advanced Glycosylation
Authors: Makita Zenji , Vlassara Helen , Rayfield Elliot , Cartwright Kenneth , Friedman Eli , Rodby Roger , Cerami Anthony , Bucala Richard
Published: October 2006

Advanced glycosylation end products (AGEs) form spontaneously from glucose-derived Amadori products and accumulate on long-lived tissue proteins. AGEs have been implicated in the pathogenesis of several of the complications of aging and diabetes, including atherosclerosis and renal disease. With the use of recently developed AGE-specific antibodies, an AGE-modified form of human hemoglobin has been identified. Termed hemoglobin-AGE (Hb-AGE), this modified species accounts for 0.42 percent of circulating hemoglobin in normal individuals but increases to 0.75 percent in patients with diabetes-induced hyperglycemia. In a group of diabetic patients treated with the advanced glycosylation inhibitor aminoguanidine, Hb-AGE levels decreased significantly over a 1-month period. Hemoglobin-AGE measurements may provide an index of long-term tissue modification by AGEs and prove useful in assessing the contribution of advanced glycosylation to a variety of diabetic and age-related complications.
Cesium-137 in Alaskan Eskimos
Authors: Palmer Harvey E. , Hanson Wayne C. , Griffin Bobby I. , Roesch William C.
Published: October 2006

During the summer of 1962, levels of radioactivity in over 700 people at four villages above the Arctic Circle in Alaska were measured with a transportable whole-body counter. The averages for body burden of cesium-137 were much higher than the average for people in the rest of the United States. The people of the interior village of Anaktuvuk Pass had the highest average burden of cesium-137, which was 421 nanocuries; the maximum burden was 790 nanocuries.
Translational Control of Protein Synthesis in a Cell-Free System Directed by a Polycistronic Viral RNA
Authors: Ohtaka Y. , Spiegelman S.
Published: October 2006

Observations with RNA isolated from the RNA virus indicate that regulation of protein synthesis occurs during translation. At least three electrophoretically separable proteins, one of which lacks histidine, appear as a result of adding purified viral RNA to a cell-free extract of
Escherichia coli
. This establishes that the RNA contains at least three cistrons. Comparison of the kinetics of appearance of the proteins that do and do not contain histidine reveals a control mechanism which determines the temporal order and the frequency of translation of each cistron. Such translational controls at the stage of message use provide additional devices for regulating protein synthesis which can supplement those functioning at the transcription step where genetic messages are produced.
Hydroxyurea: Mechanism of Action
Authors: Fishbein William N. , Carbone Paul P.
Published: October 2006

Acetohydroxamic acid has been identified, by paper chromatography, in the blood of three patients with chronic myelogenous leukemia on hydroxyurea therapy. This suggests that the drug is hydrolyzed yielding hyroxylamine, which then cleaves thioesters, in particular acetyl-coenzyme A.
Melatonin Synthesis in the Pineal Gland: Control by Light
Authors: Wurtman Richard J. , Axelrod Julius , Phillips Lawrence S.
Published: October 2006

In rats placed in continuous darkness for 6 days, there is a striking increase in the activity of melatonin-synthesizing-enzyme (hydroxyindole-O-methyl transferase) in the pineal gland, but no change in the activity of monoamine oxidase. Since melatonin appears to have a hormonal role in mammals, and its synthesis is confined to the pineal gland, the inhibition of hydroxyindole-O-methyl transferase by light may constitute a mechanism of neuroendocrine regulation.
Drug-Induced Changes in the Liver Endoplasmic Reticulum: Association with Drug-Metabolizing Enzymes
Authors: Remmer H. , Merker H. J.
Published: October 2006

The cellular changes which lead to the increase of drug-metabolizing enzymes following drug administration are explained by correlating new biochemical data with previously reported electron microscopic and pharmacologic observations. Repeated administration of phenobarbital and several other drugs results in a quantitative increase of the smooth endoplasmic reticulum of the liver cell. The marked increase in drug-metabolizing enzymes is found to occur in this enlarged smooth membrane fraction of the endoplasmic reticulum.
Umbrella Pine,
Sciadopitys verticillata
: Past and Present Distribution in Japan
Authors: Tsukada Matsuo
Published: October 2006

The umbrella pine,
Sciadopitys verticillata
S. and Z., a native Japanese conifer species and the only present member of the genus
Sciadopitys
, has become rapidly restricted in its geographic distribution since the beginning of intensified human activities. In Japan the genus was more widely distributed throughout the Pliocene and in the postglacial hypsithermal and slightly later times (R IIIa). In other parts of the world the genus has not appeared in the fossil record since the early Pleistocene. Conservation of this species is needed.
Taste of Sodium Chloride Solutions after Adaptation to Sodium Chloride: Implications for the "Water Taste"
Authors: Bartoshuk Linda M. , McBurney Donald H. , Pfaffmann Carl
Published: October 2006

After adaptation of the human tongue to sodium chloride solutions, subjects reported the taste quality of sodium chloride solutions both above and below the adapting concentration. The adapting solutions became tasteless; solutions weaker than the adapting concentration tasted sour or bitter, and stronger solutions were reported as sweet or salty. The taste of both water and sodium chloride solutions is specific depending on prior adaptation.
Compact Bone in Chinese and Japanese
Authors: Garn Stanley M. , Pao Eleanor M. , Rihl Michal E.
Published: October 2006

Measurements in vivo of compact bone in individuals of Chinese and Japanese ancestry, whether American-born or born abroad, show them to have less compact bone per unit length than Americans of European ancestry.
Excretion of Hypertonic Urine by a Teleost
Authors: Stanley Jon G. , Fleming Warren R.
Published: October 2006

During the course of adaptation to sea water,
Fundulus kansae
excretes urine that is hypertonic to the blood, but hypotonic to sea water. During this period the osmotic pressure of the serum is greater than that found in animals adapted to fresh water or sea water. The urine collected from fish adapted to sea water is usually isotonic to the blood.
Myocardial Infarction: A Response to Social Interaction among Chickens
Authors: Ratcliffe H. L. , Snyder R. L.
Published: October 2006

A study of male and female chickens caged alone, in male-female pairs, in groups of four males and in heterosexual groups of 6, 12, and 24, with a proportion of two males to one female, suggests that coronary arterial disease with myocardial infarction may be a response to social interaction, especially interaction that relates to sexual behavior. Myocardial infarcts were limited to males of heterosexual pairs and groups and to females of groups that contained 24 chickens. The lesion was found in males that died at 16 to 44 weeks of age, and in females at 32 to 43 weeks.
Water Turnover in Cattle
Authors: Black A. L. , Baker N. F. , Bartley J. C. , Chapman T. E. , Phillips R. W.
Published: October 2006

The half-life of the body water pool in cattle is unusually short, relative to their body size. The short half-life is not due to milk formation, since the same result is observed in nonlactating cattle as in cattle producing 23 kg (50 lb) of milk per day.