bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimetabolic Extract from the Brain of the Hibernating Ground Squirrel
Citellus tridecemlineatus
Authors: Swan Henry , Schätte Christopher
Published: October 2006

Extracts of subcortical brains from hibernating ground squirrels, when injected intravenously into rats, caused a mean decrease in oxygen consumption of 35 percent and a decline in body temperature of 5°C. The effects lasted from 75 minutes to 30 hours. Brain extracts of nonhibernating squirrels caused no significant changes in these parameters.
Interaction Between Transcription Regulatory Regions of Prolactin Chromatin
Authors: Cullen Katherine E. , Kladde Michael P. , Seyfred Mark A.
Published: October 2006

The regulation of transcription requires complex interactions between proteins bound to DNA sequences that are often separated by hundreds of base pairs. As demonstrated by a nuclear ligation assay, the distal enhancer and the proximal promoter regions of the rat
prolactin
gene were found to be juxtaposed. By acting through its receptor bound to the distal enhancer, estrogen stimulated the interaction between the distal and proximal regulatory regions two- to threefold compared to control values. Thus, the chromatin structure of the
prolactin
gene may facilitate the occurrence of protein-protein interactions between transcription factors bound to widely separated regulatory elements.
NMR Structure of a Specific DNA Complex of Zn-Containing DNA Binding Domain of GATA-1
Authors: Omichinski James G. , Clore G. Marius , Schaad Olivier , Felsenfeld Gary , Trainor Cecelia , Appella Ettore , Stahl Stephen J. , Gronenborn Angela M.
Published: October 2006

The three-dimensional solution structure of a complex between the DNA binding domain of the chicken erythroid transcription factor GATA-1 and its cognate DNA site has been determined with multidimensional heteronuclear magnetic resonance spectroscopy. The DNA binding domain consists of a core which contains a zinc coordinated by four cysteines and a carboxyl-terminal tail. The core is composed of two irregular antiparallel β sheets and an α helix, followed by a long loop that leads into the carboxyl-terminal tail. The amino-terminal part of the core, including the helix, is similar in structure, although not in sequence, to the amino-terminal zinc module of the glucocorticoid receptor DNA binding domain. In the other regions, the structures of these two DNA binding domains are entirely different. The DNA target site in contact with the protein spans eight base pairs. The helix and the loop connecting the two antiparallel β sheets interact with the major groove of the DNA. The carboxyl-terminal tail, which is an essential determinant of specific binding, wraps around into the minor groove. The complex resembles a hand holding a rope with the palm and fingers representing the protein core and the thumb, the carboxyl-terminal tail. The specific interactions between GATA-1 and DNA in the major groove are mainly hydrophobic in nature, which accounts for the preponderance of thymines in the target site. A large number of interactions are observed with the phosphate backbone.
An NAD Derivative Produced During Transfer RNA Splicing: ADP-Ribose 1′′-2′′Cyclic Phosphate
Authors: Culver Gloria M. , McCraith Stephen M. , Zillmann Martin , Kierzek Ryszard , Michaud Neil , LaReau Richard D. , Turner Douglas H. , Phizicky Eric M.
Published: October 2006

Transfer RNA (tRNA) splicing is essential in
Saccharomyces cerevisiae
as well as in humans, and many of its features are the same in both. In yeast, the final step of this process is removal of the 2′ phosphate generated at the splice junction during ligation. A nicotinamide adenine dinucleotide (NAD)-dependent phosphotransferase catalyzes removal of the 2′ phosphate and produces a small molecule. It is shown here that this small molecule is an NAD derivative: adenosine diphosphate (ADP)-ribose 1"-2" cyclic phosphate. Evidence is also presented that this molecule is produced in
Xenopus laevis
oocytes as a result of dephosphorylation of ligated tRNA.
Cellular Mechanisms of a Synchronized Oscillation in the Thalamus
Authors: Krosigk von Marcus , Bal Thierry , McCormick David A.
Published: October 2006

Spindle waves are a prototypical example of synchronized oscillations, a common feature of neuronal activity in thalamic and cortical systems in sleeping and waking animals. Spontaneous spindle waves recorded from slices of the ferret lateral geniculate nucleus were generated by rebound burst firing in relay cells. This rebound burst firing resulted from inhibitory postsynaptic potentials arriving from the perigeniculate nucleus, the cells of which were activated by burst firing in relay neurons. Reduction of γ-aminobutyric acid
A
(GABA
A
) receptor-mediated inhibition markedly enhanced GABA
B
inhibitory postsynaptic potentials in relay cells and subsequently generated a slowed and rhythmic population activity resembling that which occurs during an absence seizure. Pharmacological block of GABA
B
receptors abolished this seizure-like activity but not normal spindle waves, suggesting that GABA
B
antagonists may be useful in the treatment of absence seizures.
A Common Nuclear Signal Transduction Pathway Activated by Growth Factor and Cytokine Receptors
Authors: Sadowski Henry B. , Shuai Ke , Darnell James E. , Gilman Michael Z.
Published: October 2006

Growth factors and cytokines act through cell surface receptors with different biochemical properties. Yet each type of receptor can elicit similar as well as distinct biological responses in target cells, suggesting that distinct classes of receptors activate common gene sets. Epidermal growth factor, interferon-γ, and interleukin-6 all activated, through direct tyrosine phosphorylation, latent cytoplasmic transcription factors that recognized similar DNA elements. However, different ligands activated different patterns of factors with distinct DNA-binding specificities in the same and different cells. Thus, unrelated receptors may activate a common nuclear signal transduction pathway that, through differential use of latent cytoplasmic proteins, permits these receptors to regulate both common and unique sets of genes.
Norepinephrine-Dopamine Interactions and Behavior
Authors: Antelman Seymour M. , Caggiula Anthony R.
Published: October 2006

The proposed hypothesis is directed toward explaining a number of disparate findings in terms of a stress-related interaction between the NE- and DA-containing systems in the brain. The deleterious behavioral effects of decreased DA activity, for example, may be counterbalanced by a similar decrease occurring in NE activity, such compensation being most likely to occur under conditions of stress. This hypothesis may have application to the understanding of neurological and mental disorders such as Parkinson's disease and schizophrenia.
Aequorin Luminescence: Relation of Light Emission to Calcium Concentration—A Calcium-Independent Component
Authors: Allen David G. , Blinks John R. , Prendergast Franklyn G.
Published: October 2006

Light emission from the calcium-sensitive bioluminescent protein aequorin was measured at calcium ion concentrations of 10
-9
to 10
-2
molar. At very low Ca
2+
concentrations, light emission is independent of calcium ion concentration. The maximum slope of the log-log plot of light as a function of calcium ion concentration is about 2.5. The complete relation is well described by a two-state model involving three calcium-binding sites.
Blood-Brain Barrier Penetration and in Vivo Activity of an NGF Conjugate
Authors: Friden Phillip M. , Walus Lee R. , Watson Patricia , Doctrow Susan R. , Kozarich John W. , Bäckman Cristina , Bergman Hanna , Hoffer Barry , Bloom Floyd , Granholm Ann-Charlotte
Published: October 2006

Nerve growth factor (NGF) is essential for the survival of both peripheral ganglion cells and central cholinergic neurons of the basal forebrain. The accelerated loss of central cholinergic neurons during Alzheimer's disease may be a determinant of dementia in these patients and may therefore suggest a therapeutic role for NGF. However, NGF does not significantly penetrate the blood-brain barrier, which makes its clinical utility dependent on invasive neurosurgical procedures. When conjugated to an antibody to the transferrin receptor, however, NGF crossed the blood-brain barrier after peripheral injection. This conjugated NGF increased the survival of both cholinergic and noncholinergic neurons of the medial septal nucleus that had been transplanted into the anterior chamber of the rat eye. This approach may prove useful for the treatment of Alzheimer's disease and other neurological disorders that are amenable to treatment by proteins that do not readily cross the blood-brain barrier.
The Prevention of Thymic Lymphomas in Transgenic Mice by Human O
6
-Alkylguanine-DNA Alkyltransferase
Authors: Dumenco Luba L. , Allay Esther , Norton Kathleen , Gerson Stanton L.
Published: October 2006

Nitrosoureas form
O
6
-alkylguanine-DNA adducts that are converted to G to A transitions, the mutation found in the activated
ras
oncogenes of nitrosourea-induced mouse lymphomas and rat mammary tumors. These adducts are removed by the DNA repair protein
O
6
-alkylguanine-DNA alkyltransferase. Transgenic mice that express the human homolog of this protein in the thymus were found to be protected from developing thymic lymphomas after exposure to
N
-methyl-
N
-nitrosourea. Thus, transgenic expression of a single human DNA repair gene is sufficient to block chemical carcinogenesis. The transduction of DNA repair genes in vivo may unravel mechanisms of carcinogenesis and provide therapeutic protection from known carcinogens.
The Skipping of Constitutive Exons in Vivo Induced by Nonsense Mutations
Authors: Dietz Harry C. , Valle David , Francomano Clair A. , Kendzior Raymond J. , Pyeritz Reed E. , Cutting Garry A.
Published: October 2006

Nonsense mutations create a premature signal for the termination of translation of messenger RNA. Such mutations have been observed to cause a severe reduction in the amount of mutant allele transcript or to generate a peptide truncated at the carboxyl end. Analysis of fibrillin transcript from a patient with Marfan syndrome revealed the skipping of a constitutive exon containing a nonsense mutation. Similar results were observed for two nonsense mutations in the gene encoding ornithine δ-aminotransferase from patients with gyrate atrophy. All genomic DNA sequences flanking these exons that are known to influence RNA splicing were unaltered, which suggests that nonsense mutations can alter splice site selection in vivo.
The Secretory Granule Matrix: A Fast-Acting Smart Polymer
Authors: Nanavati Chaya , Fernandez Julio M.
Published: October 2006

The secretory granule matrix is a miniature biopolymer that consists of a charged polymer network that traps peptides and transmitters when it condenses and releases them on exocytotic decondensation. Models of exocytotic fusion have treated this matrix as a short circuit and have neglected its electrical contributions. This matrix responded to negative voltages by swelling, which was accompanied by a large increase in conductance, and to positive voltages by condensing. Thus, the matrix resembled a diode. The swollen matrix exerted large pressures on the order of 12 bar. The responses took place within milliseconds of the application of the electric field. These findings suggest that matrix decondensation, and therefore product release, is controlled by potential gradients.
A Three-Dimensional View of Precursor Messenger RNA Metabolism Within the Mammalian Nucleus
Authors: Carter Kenneth C. , Bowman Douglas , Carrington Walter , Fogarty Kevin , McNeil John A. , Fay Fredric S. , Lawrence Jeanne Bentley
Published: October 2006

A quantitative three-dimensional analysis of nuclear components involved in precursor messenger RNA metabolism was performed with a combination of fluorescence hybridization, immunofluorescence, and digital imaging microscopy. Polyadenylate [poly(A)] RNA-rich transcript domains were discrete, internal nuclear regions that formed a ventrally positioned horizontal array in monolayer cells. A dimmer, sometimes strand-like, poly(A) RNA signal was dispersed throughout the nucleoplasm. Spliceosome assembly factor SC-35 localized within the center of individual domains. These data support a nuclear model in which there is a specific topological arrangement of noncontiguous centers involved in precursor messenger RNA metabolism, from which RNA transport toward the nuclear envelope radiates.
Inhibition of Human Colon Cancer Growth by Antibody-Directed Human LAK Cells in SCID Mice
Authors: Takahashi Hiroshi , Nakada Tetsuya , Puisieux Isabelle
Published: October 2006

Advanced human colon cancer does not respond to lymphokine-activated killer (LAK) cells. In order to direct cytotoxic cells to the tumor, human LAK cells linked with antibodies to a tumor cell surface antigen were tested with established hepatic metastases in severe combined immunodeficient (SCID) mice. These cells had increased uptake into the tumor and suppression of tumor growth as compared with LAK cells alone, thereby improving the survival of tumor-bearing mice. Thus, tumor growth can be inhibited by targeted LAK cells, and SCID mice can be used to test the antitumor properties of human effector cells.
Optical Time-of-Flight and Absorbance Imaging of Biologic Media
Authors: Benaron David A. , Stevenson David K.
Published: October 2006

Imaging the interior of living bodies with light may assist in the diagnosis and treatment of a number of clinical problems, which include the early detection of tumors and hypoxic cerebral injury. An existing picosecond time-of-flight and absorbance (TOFA) optical system has been used to image a model biologic system and a rat. Model measurements confirmed TOFA principles in systems with a high degree of photon scattering; rat images, which were constructed from the variable time delays experienced by a fixed fraction of early-arriving transmitted photons, revealed identifiable internal structure. A combination of light-based quantitative measurement and TOFA localization may have applications in continuous, noninvasive monitoring for structural imaging and spatial chemometric analysis in humans.
DNA Repair Helicase: a Component of BTF2 (TFIIH) Basic Transcription Factor
Authors: Schaeffer Laurent , Roy Richard , Humbert Sandrine , Moncollin Vincent , Vermeulen Wim , Hoeijmakers Jan H. J. , Chambon Pierre , Egly Jean-Marc
Published: October 2006

The human BTF2 basic transcription factor (also called TFIIH), which is similar to the δ factor in rat and factor b in yeast, is required for class II gene transcription. A strand displacement assay was used to show that highly purified preparation of BTF2 had an adenosine triphosphate-dependent DNA helicase activity, in addition to the previously characterized carboxyl-terminal domain kinase activity. Amino acid sequence analysis of the tryptic digest generated from the 89-kilodalton subunit of BTF2 indicated that this polypeptide corresponded to the
ERCC-3
gene product, a presumed helicase implicated in the human DNA excision repair disorders xeroderma pigmentosum and Cockayne's syndrome. These findings suggest that transcription and nucleotide excision repair may share common factors and hence may be considered to be functionally related.
Laser Interferometer Measurement of Changes in Crayfish Axon Diameter Concurrent with Action Potential
Authors: Hill Bruce C. , Schubert Earl D. , Nokes Mark A. , Michelson Robin P.
Published: October 2006

Small rapid changes in the diameter of an axon take place when an action potential progresses along the axon. In the giant axon of the crayfish these occur within a period of about 1 millisecond and are typically about 18 angstroms in total amplitude.
Venereal Transmission of La Crosse (California encephalitis) Arbovirus in
Aedes triseriatus
Mosquitoes
Authors: Thompson Wayne H. , Beaty Barry J.
Published: October 2006

Venereal transmission of La Crosse virus by males of
Aedes triseriatus
was demonstrated. La Crosse virus was detected in the bursa of females after induced copulation, and disseminated infection was shown to occur occasionally. Since males of
Aedes triseriatus
have transovarial filial infection rates similar to those of females and can repeatedly mate, venereal transmission may be an important supplement to other natural endemic maintenance mechanisms.
IL-6-Induced Homodimerization of gp130 and Associated Activation of a Tyrosine Kinase
Authors: Murakami Masaaki , Hibi Masahiko , Nakagawa Naoko , Nakagawa Toshimasa , Yasukawa Kiyoshi , Yamanishi Koichi , Taga Tetsuya , Kishimoto Tadamitsu
Published: October 2006

The biological functions of interleukin-6 (IL-6) are mediated through a signal-transducing component of the IL-6 receptor, gp130, which is associated with the ligand-occupied IL-6 receptor (IL-6R) protein. Binding of IL-6 to IL-6R induced disulfide-linked homodimerization of gp130. Tyrosine kinase activity was associated with dimerized but not monomeric gp130 protein. Substitution of serine for proline residues 656 and 658 in the cytoplasmic motif abolished tyrosine kinase activation and cellular responses but not homodimerization of gp130. The IL-6-induced gp130 homodimer appears to be similar in function to the heterodimer formed between the leukemia inhibitory factor (LIF) receptor (LIFR) and gp130 in response to the LIF or ciliary neurotrophic factor (CNTF). Thus, a general first step in IL-6-related cytokine signaling may be the dimerization of signal-transducing molecules and activation of associated tyrosine kinases.
Pathogenic Amoebas from Brackish and Ocean Sediments, with a Description of
Acanthamoeba hatchetti
, n. sp.
Authors: Sawyer Thomas K. , Visvesvara Govinda S. , Harke Bruce A,
Published: October 2006

Acanthamoeba culbertsoni
was isolated from a sewage-spoil dump site near Ambrose Light, New York Bight. A second species,
Acanthamoeba hatchetti
, n. sp., was isolated from Brewerton Channel, Baltimore Harbor, Maryland. Both species killed laboratory mice after infection by the intranasal route.
Potential Operating Region for Ultrasoft X-Ray Microscopy of Biological Materials
Authors: Sayre D. , Kirz J. , Feder R. , Kim D. M. , Spiller E.
Published: October 2006

Calculations are presented which indicate an extensive suboptical region in the microscopy of biological materials in their natural state which is accessible to ultrasoft x-ray transmission microscopy. Throughout most of the region, radiation dosage levels to the specimen are lower than in electron microscopy.
Somatostatin: Analogs with Selected Biological Activities
Authors: Brown Marvin , Rivier Jean , Vale Wylie
Published: October 2006

[D-Cys
14
]-Somatostatin is the first analog of somatostatin found to be more potent in inhibiting glucagon and growth hormone secretion than it is in inhibiting insulin secretion. [D-Trp
8
]-Somatostatin is eight to ten times more potent than somatostatin in inhibiting insulin, glucagon, and growth hormone secretion. [D-Trp
8
,D-Cys
14
]-Somatostatin is more potent than [D-Cys
14
]-somatostatin, but retains its relative selectivity in being a more potent inhibitor of the secretion of glucagon and growth hormone than of insulin.
Animal Parthenogenesis
Authors: Cuellar O.
Published: October 2006

The available evidence on the ecological factors favoring the existence and origin of natural parthenogenesis is evaluated. Analysis of the geographical distributions of the well-known cases of animal parthenogenesis in nature reveals (i) that most of these species exist in natural disclimax communities and (ii) that within these communities they exist in isolation from closely related congeneric species. Parthenogenesis can only evolve in areas devoid of the generating bisexual species, because such species would prevent newly formed unisexuals from establishing clones due either to hybridization or competition. Furthermore, the two unique features allowing parthenogenetic species to invade and occupy open habitats faster than bisexuals are (i) a double intrinsic rate of increase and (ii) the ability of one individual to establish a new colony.
A Specific High-Affinity Binding Macromolecule for 1,25-Dihydroxyvitamin D
3
in Fetal Bone
Authors: Kream B. E. , Jose M. , Yamada S. , DeLuca H. F.
Published: October 2006

Cytosol fractions were prepared from fetal rat or embryonic chick calvaria and analyzed for binding of vitamin D
3
metabolites on sucrose density gradients. Both cytosol fractions contain a 3.5
S
macromolecule which specifically binds 1,25-dihydroxy-[
3
H]vitamin D
3
and in addition, a 5 to 6
S
macromolecule which binds 25-hydroxy-[
3
H]vitamin D
3
. In rat calvaria cytosol, 1,25-dihydroxy-[
3
H]vitamin D
3
also binds to the 5 to 6
S
macromolecule but appears to have greater affinity for the 3.5
S
component.
Auditory Evoked Potentials as Probes of Hemispheric Differences in Cognitive Processing
Authors: Shucard D. W. , Shucard J. L. , Thomas D. G.
Published: October 2006

The amplitude of auditory evoked potentials recorded from the cerebral hemispheres to pairs of task-irrelevant tones was related to differential hemispheric engagement in ongoing cognitive activity (for example, verbal versus musical). The hemisphere hypothesized to be most engaged in the ongoing cognitive task, as compared to the unengaged hemisphere, produced a greater potential difference between the temporal and reference electrode to the second of the tone pairs. These findings are related to "fast habituation" and "recovery cycle.".
Some Soil Factors Affecting Tree Growth
Authors: Salter Robt. M.
Published: October 2006

(1) It becomes increasingly evident that continued root growth with the establishment of new root-soil contacts is necessary for the normal entrance of both water and mineral nutrients into the root. This concept emphasizes the ecological importance of factors tending either to impede or favor the spread and permeation of roots in the soil.

(2) The characteristics of soils with respect to (1) available water capacity, (2) permeability to water and (3) permeability to air are largely determined by the volume and size distribution of the soil pore space. The latter is conveniently characterized by measuring the water held by a soil at varying moisture tensions.

(3) In recognition of the foregoing, it may be concluded that a better understanding of root-soil relationships should result from more general application of interpretative studies of soil pore space conditions to root development, and from the development and application of micro-methods for studying the conditions, both physical and chemical, existing at the actual root soil interface.
Blind Man Living in Normal Society Has Circadian Rhythms of 24.9 Hours
Authors: Miles L. E. M. , Raynal D. M. , Wilson M. A.
Published: October 2006

A psychologically normal blind man, living and working in normal society, suffered from a severe cyclic sleep-wake disorder. Investigations showed that he had circadian rhythms of body temperature, alertness, performance, cortisol secretion, and urinary electrolyte excretion which were desynchronized from the 24-hour societal schedule. These rhythms all had periods which were longer than 24 hours and indistinguishable from the period of the lunar day.
Construction of Chimeric Phages and Plasmids Containing the Origin of Replication of Bacteriophage Lambda
Authors: Moore David D. , Denniston-Thompson Katherine , Furth Mark E. , Williams Bill G. , Blattner Frederick R.
Published: October 2006

Segments of the replication control region of bacteriophage lambda (λ) and λ mutants defective in replication were attached in vitro to the φ80 phage vector Charon 3 and to the plasmid vector
mini Col
El (pVH51). The chimeric phages and plasmids have been used to localize the origin of λ DNA replication and to facilitate a structural analysis of the λ replicator.
Drinking Water and Cancer Mortality in Louisiana
Authors: Page Talbot , Harris Robert H. , Epstein Samuel S.
Published: October 2006

Multivariant regression analysis indicates a statistically significant relation between cancer mortality rates in Louisiana and drinking water obtained from the Mississippi River. This is true for total cancer, cancer of the urinary organs, and cancer of the gastrointestinal tract.
Fever: Effect of Drug-Induced Antipyresis on Survival
Authors: Bernheim Harry A. , Kluger Matthew J.
Published: October 2006

To determine whether the prevention of fever affects the survival of an animal infected with pathogenic bacteria, lizards (
Dipsosaurus dorsalis
) were infected with live
Aeromonas hydrophila
and received varying doses of sodium salicylate, an antipyretic drug. Twelve lizards received identical injections of bacteria along with a nontoxic dose of sodium salicylate; five animals increased their mean body temperature at least 0.6°C and survived the week, whereas seven did not develop a fever and died within 3 days. These data indicate that in these lizards the prevention of fever by use of an antipyretic drug such as sodium salicylate increases the mortality rate from bacterial infection.
Multiplication of a Human Parasite (
Leishmania donovani
) in Phagolysosomes of Hamster Macrophages in Vitro
Authors: Chang Kwang-Poo , Dwyer Dennis M.
Published: October 2006

Leishmania donovani
, the etiological agent of human visceral leishmaniasis, was grown in hamster peritoneal macrophages in vitro. By electron microscopy, using a lysosomal marker, these parasitic protozoa were seen to multiply within host cell phagolysosomes. The survival mechanism of this intracellular parasite is based apparently upon resistance to macrophage lysosomal enzymic digestion.
Black Widow Spider Venom: Effect of Purified Toxin on Lipid Bilayer Membranes
Authors: Finkelstein Alan , Rubin Lee L. , Tzeng Mu-Chin
Published: October 2006

A purified toxin (the B
5
fraction) from black widow spider venom added to the solution on one side of a lipid bilayer membrane interacts irreversibly with the membrane to produce a continuous, linear rise of membrane conductance with time. Conductances greater than 10
-4
reciprocal ohm per square centimeter can eventually be attained without any loss of membrane stability. Membranes treated with toxin are ideally selective for alkali cations over anions and are substantially permeable to calcium ion. These effects of the toxin result from the formation of permanent channels in the membrane of uniform conductance, 3.6 × 10
-10
reciprocal ohm (in 0.1 molar potassium chloride), that remain open almost all the time. Both the divalent cation permeability and the smaller conductances at low
p
H of toxin-treated membranes suggest that there is negative charge (possibly from carboxyl groups) associated with the channels. We discuss the possible relation of the action of this toxin on lipid bilayer membranes to its ability to stimulate massive transmitter release at the neuromuscular junction and to produce profound morphological changes on tissue cultured neurons.
Structural Basis for ON-and OFF-Center Responses in Retinal Ganglion Cells
Authors: Famiglietti E. V. , Kolb Helga
Published: October 2006

The inner plexiform layer of the mammalian retina has a bisublaminar organization determined by restricted branching of the terminals of cone bipolar cells and dendrites of class I (large) and class II (small) ganglion cells. Comparison of dendritic field diameters and receptive field center sizes of large ganglion cells suggests that neural circuitry in sublamina a conveys "OFF"-center properties and connections in sublamina
b
"ON"-center properties to retinal ganglion cells.
Carotenoids of Telial Galls of
Gymnosporangium juniperi-virginianae
Lk.
Authors: Smits B. L. , Peterson W. J.
Published: October 2006

In an investigation of the pigments of the telial galls of the common rust fungus
Gymnosporangium juniperi-virginianae
Lk. β- and γ-carotenes were shown to be the only carotenoids present, with the γ-isomer predominating. The identification of γ-carotene was based on its more characteristic properties, behavior on an adsorbent, and its absorption spectra. Neither free nor esterified xanthophylls were present, and only traces of chlorophyll.

The leaves of the juniper, besides containing chlorophyll, showed the presence of α-, β- and γ-carotene.
Evidence of Morphological and Physiological Transformation of Mammalian Cells by Strong Magnetic Fields
Authors: Malinin George I. , Gregory William D. , Morelli Luigi , Sharma Vishwa K. , Houck John C.
Published: October 2006

Cultures of L-929 and WI-38 cells, frozen to 4.2°K and exposed for 4 to 8 hours to 5000-oersted magnetic fields, were markedly inhibited in their growth as compared to controls. In cultures grown on cover slips, approximately 7 days after exposure, morphologically distinct cells emerged and were propagated from generation to generation; 3 weeks later, in flask cultures, contact inhibition was abolished. It is concluded that under certain experimental conditions, strong magnetic fields induce morphological and physiological transformations of target cells.
Calcinogenic Factor in
Solanum malacoxylon
: Evidence That It Is 1,25-Dihydroxyvitamin D
3
-Glycoside
Authors: Wasserman R. H. , Henion John D. , Haussler Mark R. , McCain Toni A.
Published: October 2006

After glycosidic cleavage of the water-soluble vitamin D-like principle of the calcinogenic plant
Solanum malacoxylon
, the active lipophilic portion was purified by column chromatography and analyzed by combined gas chromatography and mass spectrometry. It was identified as 1,25-dihydroxyvitamin D
3
, the active form of vitamin D. Thus this active metabolite of vitamin D exists in the plant world, and its presence probably accounts for pathologic calcification in grazing animals ingesting
Solanum malacoxylon
.
Nitrous Oxide "Analgesia": Resemblance to Opiate Action
Authors: Berkowitz Barry A. , Ngai S. H. , Finck A. Donald
Published: October 2006

Nitrous oxide produced a dose-related "analgesia" in mice (median effective dose, 55 percent). The analgesia was evaluated by means of a phenylquinone writhing test. Narcotic antagonists or chronic morphinization reduced nitrous oxide analgesia. Either nitrous oxide releases an endogenous analgesic or narcotic antagonists have analgesic antagonist properties heretofore unappreciated.
OPTIMIZATION OF HIERARCHICAL STRUCTURES OF INFORMATION FLOW
Authors: STAUFFER D. , de OLIVEIRA P. M. C.
Published: October 2006

The efficiency of a large hierarchical organisation is simulated on Barabási–Albert networks, when each needed link leads to a loss of information. The optimum is found at a finite network size, corresponding to about five hierarchical layers, provided a cost for building the network is included in our optimization.
TARGET DETECTION WITHIN SEA CLUTTER: A COMPARATIVE STUDY BY FRACTAL SCALING ANALYSES
Authors: HU JING , GAO JIANBO , POSNER FRED L. , ZHENG YI , TUNG WEN-WEN
Published: October 2006

Sea clutter refers to the radar returns from a patch of ocean surface. Accurate modeling of sea clutter and robust detection of low observable targets within sea clutter are important problems in remote sensing and radar signal processing applications. Due to lack of fundamental understanding of the nature of sea clutter, however, no simple and effective methods for detecting targets within sea clutter have been proposed. To help solve this important problem, we apply three types of fractal scaling analyses, fluctuation analysis (FA), detrended fluctuation analysis (DFA), and the wavelet-based fractal scaling analysis to study sea clutter. Our analyses show that sea clutter data exhibit fractal behaviors in the time scale range of about 0.01 seconds to a few seconds. The physical significance of these time scales is discussed. We emphasize that time scales characterizing fractal scaling break are among the most important features for detecting patterns using fractal theory. By systematically studying 392 sea clutter time series measured under various sea and weather conditions, we find very effective methods for detecting targets within sea clutter. Based on the data available to us, the accuracy of these methods is close to 100%.
Glucocorticoids Specifically Enhance L-Type Calcium Current Amplitude and Affect Calcium Channel Subunit Expression in the Mouse Hippocampus
Authors: Chameau Pascal , Qin Yongjun , Spijker Sabine , Smit Guus , Joëls Marian
Published: October 2006

Previous studies have shown that corticosterone enhances whole cell calcium currents in CA1 pyramidal neurons, through a pathway involving binding of glucocorticoid receptor homodimers to the DNA. We examined whether glucocorticoids show selectivity for L- over N-type of calcium currents. Moreover, we addressed the putative gene targets that eventually lead to the enhanced calcium currents. Electrophysiological recordings were performed in nucleated patches that allow excellent voltage control. Calcium currents in these patches almost exclusively involve N- and L-type channels. We found that L- but not N-type calcium currents were largely enhanced after treatment with a high dose of corticosterone sufficient to activate glucocorticoid receptors. Voltage dependency and kinetic properties of the currents were unaffected by the hormone. Nonstationary noise analysis suggests that the increased current is not caused by a larger unitary conductance, but rather to a doubling of the number of functional channels. Quantitative real-time PCR revealed that transcripts of the Cav1 subunits encoding for the N- or L-type calcium channels are not upregulated in the mouse CA1 area; instead, a strong, direct, and consistent upregulation of the β4 subunit was observed. This indicates that the corticosteroid-induced increase in number of L-type calcium channels is not caused by a simple transcriptional regulation of the pore-forming subunit of the channels.
Molecular relapse in adult standard-risk ALL patients detected by prospective MRD monitoring during and after maintenance treatment: data from the GMALL 06/99 and 07/03 trials
Authors: Raff Thorsten , Gökbuget Nicola , Lüschen Silke , Reutzel Regina , Ritgen Matthias , Irmer Sebastian , Böttcher Sebastian , Horst Heinz-August , Kneba Michael , Hoelzer Dieter , Brüggemann Monika ,   for the GMALL Study Group
Published: October 2006

Although levels of minimal residual disease (MRD) decrease below the detection limit in most adult patients with standard-risk acute lymphoblastic leukemia (ALL) after consolidation treatment, about 30% of these patients will ultimately relapse. To evaluate the power of MRD monitoring as an indicator of impending relapse, we prospectively analyzed postconsolidation samples of 105 patients enrolled in the German Multicenter ALL (GMALL) trial by real-time quantitative polymerase chain reaction (PCR) of clonal immune gene rearrangements. All patients were in hematologic remission, had completed first-year polychemotherapy, and tested MRD negative prior to study entry. Twenty-eight of 105 patients (27%) converted to MRD positivity thereafter, and 17 of 28 (61%) relapsed so far. Median time from molecular (MRD-positive) to clinical relapse was 9.5 months. In 15 of these patients, MRD within the quantitative range of PCR was measured in hematologic remission, and 13 of these patients (89%) relapsed after a median interval of 4.1 months. Of the 77 continuously MRD-negative patients, only 5 (6%) have relapsed. We conclude that conversion to MRD positivity during the early postconsolidation phase in adult standard-risk ALL patients is highly predictive of subsequent hematologic relapse. As a result of the study, as of spring 2006, salvage treatment in the ongoing GMALL trial is intended to be started at the time of recurrence of quantifiable MRD.
Arabidopsis microRNA167controls patterns ofARF6andARF8expression, and regulates both female and male reproduction
Authors: Wu Miin-Feng , Tian Qing , Reed Jason W.
Published: October 2006

In flowering plants, diploid sporophytic tissues in ovules and anthers support meiosis and subsequent haploid gametophyte development. These analogous reproductive functions suggest that common mechanisms may regulate ovule and anther development. Two Arabidopsis Auxin Response Factors,ARF6 and ARF8, regulate gynoecium and stamen development in immature flowers. Wild-type pollen grew poorly in arf6 arf8 gynoecia, correlating with ARF6 and ARF8 expression in style and transmitting tract. ARF6 and ARF8 transcripts are cleavage targets of the microRNA miR167, and overexpressing miR167 mimicked arf6 arf8 phenotypes. Mutations in the miR167 target sites of ARF6 or ARF8 caused ectopic expression of these genes in domains of both ovules and anthers where miR167 was normally present. As a result, ovule integuments had arrested growth, and anthers grew abnormally and failed to release pollen. Thus, miR167 is essential for correct patterning of gene expression, and for fertility of both ovules and anthers. The essential patterning function of miR167 contrasts with cases from animals in which miRNAs reinforce or maintain transcriptionally established gene expression patterns.
Developmental patterning of the cardiac atrioventricular canal by Notch and Hairy-related transcription factors
Authors: Rutenberg Joshua B. , Fischer Andreas , Jia Haibo , Gessler Manfred , Zhong Tao P. , Mercola Mark
Published: October 2006

Mutations in Notch2, Jagged1 or homologs of the Hairy-related transcriptional repressor Hey2 cause congenital malformations involving the non-chamber atrioventricular canal (AVC) and inner curvature (IC) regions of the heart, but the underlying mechanisms have not been investigated. By manipulating signaling directly within the developing chick heart, we demonstrated that Notch2, Hey1 and Hey2 initiate a signaling cascade that delimits the non-chamber AVC and IC regions. Specifically, misactivation of Notch2 signaling, or misexpression of either Hey1 or Hey2, repressed Bmp2. Because Jagged (also known as Serrate in non-mammalian species)ligands were found to be present in prospective chamber myocardium, these data support the model that Notch2 and Hey proteins cause the progressive restriction of Bmp2 expression to within the developing AVC and IC, where it is essential for differentiation. Misactivation or inhibition of Notch2 specifically induced or inhibited Hey1, respectively, but these manipulations did not affect Hey2, implicating Hey1 as the direct mediator of Notch2. Bmp2 within the developing AVC and IC has been shown to induce Tbx2, and we found that Tbx2 misexpression inhibited the expression of both Hey1 and Hey2. Tbx2, therefore, is envisaged to constitute a feedback loop that sharpens the border with the developing AVC and IC by delimiting Hey gene expression to within prospective chamber regions. Analysis of the loss-of-function phenotype in mouse embryos homozygous for targeted disruption of Hey2 revealed an expanded AVC domain of Bmp2. Similarly, zebrafish gridlock (Hey2 homolog) mutant embryos showed ectopic expression of Bmp4, which normally marks AVC myocardium in this species. Thus, Hey pathway regulation of cardiac Bmp appears to be an evolutionarily conserved mechanism to delimit AVC and IC fate, and provides a potential mechanistic explanation for cardiac malformations caused by mutations in Serrate/Jagged1 and Notch signaling components.
The otolaryngologic presentation of myasthenia gravis
Authors: Carpenter Robert J. , Mcdonald Thomas J. , Howard Frank M.
Published: October 2006

Myasthenia gravis is a neuromuscular disease of insidious onset, characterized by weakness and fatigability of voluntary muscles. Most patients present with symptoms relating to the head and neck and thus may be seen first by the otolaryngologist. Predominant symptoms may be ocular (ptosis or diplopia) or related to fatigue of the oropharyngeal or laryngeal musculature (dysarthria, dysphonia, or dysphagia). Alleviation of muscular weakness and fatigability after administration of anticholinesterase drugs is pathognomonic of myasthenia gravis.
Complications of frontal and ethmoid sinusitis
Authors: Morgan Philip R. , Morrison Winsor V.
Published: October 2006

A small percentage of patients with acute frontal or ethmoid sinusitis develop orbital, cranial or CNS complications. At selected University of Tennessee affiliated hospitals, from 1974 to 1978, there were 14 such cases which required major surgical intervention in addition to intensive medical therapy. The most common complication in this series was subperiosteal orbital abscess. The most common bacterial isolates were streptococcus and staphylococcus. A discussion of complications associated with frontal and ethmoid sinusitis is included as well as recommendations for medical and surgical management.
Reconstructing the absent lenticular process
Authors: Schuring Arnold G. , Lippy William H. , Rizer Franklin M.
Published: October 2006

When a surgeon encounters an absent lenticular process of the incus, he must either reposition the incus or attempt to bridge the small gap between the remaining incus long process and the stapes capitulum. Our solution to this problem is to place a Lippy modified Robinson stapes prosthesis on the stapes footplate and attach it to the remaining long process, thus bypassing the stapes superstructure. This modified Robinson prosthesis has a portion of the well removed allowing the eroded long process to enter from the side. The hearing results of 63 cases at 6 months (two‐thirds of which had a concurrent tympanoplasty) are 67% within 10 dB and 91% within 20 dB of the preoperative bone hearing level. The use of an existing and proven prosthesis provides both stability and, to date, the most successful hearing results for reconstructing the absent lenticular process.
Approaches to Teaching Design Subjects: a quantitative analysis
Authors: Trigwell Keith
Published: October 2006

This paper reports the results of a pilot study of variation in design teachers' approaches to teaching. It contains a comparison between the literature reports of qualitative descriptions of design teaching and variation obtained using a quantitative method (the Approaches to Teaching
Inventory). The quantitative approach revealed that, as in other teaching contexts, there is significant variation in descriptions of how design teaching is approached but that overall, the approaches adopted by design teachers are described as being more student-focused than in most other
areas of higher-education teaching. The results also suggest that when design teachers describe their approaches as more student-focused they are more likely to say that they learn more during the teaching of their subjects and are more likely to give students the opportunity to explore their
own creative ideas. The Approaches to Teaching Inventory was found to be a useful indicator of qualitative variation in teaching approaches in creative fields such as design.
Women under Salazar's Dictatorship
Authors: Cova Anne , Pinto Antnio Costa
Published: October 2006

This article addresses Salazarism's attitudes towards women and women's organizations, providing some elements that may be used in comparisons with the other dictatorships (e.g. Italian Fascism) that inspired, to some extent, some of the Portuguese New State's institutions.
Family Relations in Lisbon's Business Elite
Authors: de Lima Antnia Pedroso
Published: October 2006

High status groups in Portuguese society constitute a social context in which familial relations are of great importance, both at the level of family members' daily agency and on the far broader scale of their social and professional relations. The author analyses in this article the
way familial relations become important processes by which an elite social position may be maintained. The argument is based on fieldwork carried out by the author on seven leading business families in Lisbon who own large firms in operation for at least three generations. This research has
showed that the processes by which these families manage to remain majority shareholders and in the top management position in the large companies they have owned for several generations is due, to a great extent, to the fact that these economic investments are considered the symbolic materialisation
of a familial project. It is by means of carefully managing familial relations that those involved in these projects are able to ensure and reproduce their belonging to Portugal's financial and social upper set. This argument is illustrated throughout my research into the processes by which
the leading families in Portugal's economic setting before the democratic revolution in 1974 have recovered their top financial and social positions in Portugal today.
Efficient Synthesis of Medium‐Sized Rings Incorporating Indole or Pyrrole Units by Samarium Diiodide Induced Cyclizations
Authors: Blot Virginie , Reißig Hans‐Ulrich
Published: October 2006

Samarium diiodide promoted the intramolecular reductive couplings of N‐alkylated indole and pyrrole derivatives 9–12 and 14 to afford products 15–19 that incorporate seven‐ and eight‐membered rings. They were obtained in good yields and generally with excellent diastereoselectivities. Up to four contiguous stereogenic centres are controlled in this transformation, which is explained by a highly ordered transition structure with the samarium alcoholate moiety preferring an equatorial position. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Electrical spin injection into InGa(N)As quantum structures and single InGaAs quantum dots
Authors: Hetterich M. , Löffler W. , Fallert J. , Höpcke N. , Burger H. , Passow T. , Li S. , Daniel B. , Ramadout B. , Lupaca‐Schomber J. , Hetterich J. , Litvinov D. , Gerthsen D. , Klingshirn C. , Kalt H.
Published: October 2006

We investigate electrical spin injection from a semi‐magnetic n‐type ZnMnSe spin aligner into III–V p–i–n diodes with InGaAs quantum dots (QDs) in the active layer. Quantitative transmission electron microscopy techniques are applied to characterize the different dot types used. Analysis of the circular polarization degree (CPD) of the device emission indicates the spin polarization of the injected electrons. Values of more than 70% are obtained for the wetting layer and high‐energy QD states. However, the CPD shows a strong spectral dependence due to spin relaxation at the stage, before the electrons are finally captured in the dots. This is, e.g., evidenced by an initial increase of the polarization degree with rising temperature, attributed to motional narrowing effects. As a prerequisite for more detailed studies, we also demonstrate electrical spin injection into single InGaAs QDs, which should provide the basis for future single spin manipulation experiments. Finally, we suggest GaInNAs as optically active material for the realization of spin‐polarized light‐emitting diodes with long‐wavelength emission. First results indicate CPD values of up to 80% for λ = 1130 nm, suggesting this approach to be very promising. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)