bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of the Transforming Potential of a Normal Cell Sequence: A Molecular Model for Oncogenesis
Authors: Blair D. G. , Oskarsson M. , Wood T. G. , McClements W. L. , Fischinger P. J. , Vande Woude G. G.
Published: October 2006

The molecularly cloned, long terminal repeat (LTR) of the Moloney sarcoma virus (M-MSV) provirus has been covalently linked to c-
mos
, the cellular homolog of the M-MSV-specific sequence, v-
mos
. These newly constructed clones lack any M-MSV-derived sequences other than the LTR, but in DNA transfection assays they transform cells as efficiently as cloned subgenomic M-MSV fragments containing both v-
mos
and LTR. Cells transformed by LTR:c-
mos
hybrid molecules contain additional copies of
mos
DNA, and several size classes of polyadenylated RNA's with sequence homology to
mos
. The activation of the transforming potential of c-
mos
by the proviral LTR suggests a model whereby LTR-like elements could activate other normal cell sequences with oncogenic potential.
Helical Mycoplasmas (Spiroplasmas) from
Ixodes
Ticks
Authors: Tully Joseph G. , Rose David L. , Yunker Conrad E. , Cory Jack , Whitcomb Robert F. , Williamson David L.
Published: October 2006

A new spiroplasma isolated from
Ixodes pacificus
collected in Oregon was serologically and morphologically distinct from known spiroplasmas. The new spiroplasma could also be isolated in tick cell cultures. Discovery of a new fastidious mycoplasma in ticks offers opportunities to explore the possible role of these agents in human and animal diseases.
Fetal Female Rats Are Masculinized by Male Littermates Located Caudally in the Uterus
Authors: Meisel Robert L. , Ward Ingeborg L.
Published: October 2006

Female rats are masculinized in utero by male littermates sharing the same uterine horn. Increased anogenital distances in neonatal females and mounting behavior in adult females are related to the presence of males on the caudal side of the females in the uterine horn. Contrary to current beliefs, interamniotic diffusion may not be responsible for the exchange of masculinizing agents among fetuses. Since uterine blood flow in the rat is from the direction of the cervix toward the ovary, masculinizing hormones secreted by fetal males may be carried via the uterine vasculature to female littermates located further downstream.
Structural Changes at the Heme Induced by Freezing Hemoglobin
Authors: Ondrias M. R. , Rousseau D. L. , Simon S. R.
Published: October 2006

A dramatic change occurs in the vibrational properties of the iron-histidine bond,
trans
to the oxygen binding site, on freezing deoxyhemoglobin. The large, quaternary structure-dependent differences in the shape and frequency of the iron-histidine mode observed in resonance Raman scattering measurements above freezing are significantly diminished by the freezing event and the scattering intensity increases substantially. On further reduction in temperature to 10 K this broad line becomes narrow and shifts to a higher frequency. These data implicate dynamical processes and protein interaction with water as contributors to the quaternary structure dependence of the iron-histidine bond and thus reflect on the role of that bond in the energetics of cooperative ligand binding.
Centrilobular Injury Following Hypoxia in Isolated, Perfused Rat Liver
Authors: Lemasters John J. , Ji Sungchul , Thurman Ronald G.
Published: October 2006

Hypoxia was produced in isolated, hemoglobin-free, perfused rat liver by reducing the flow rate of oxygen-carrying fluid entering the organ. The procedure caused anoxia in centrilobular regions. In these anoxic areas, structural derangements developed rapidly, characterized by bleb-like protrusions of hepatocyte plasma membrane through fenestrations in the sinusoidal endothelium. Periportal tissue remained normoxic and was completely spared. Cellular injury resulting from localized anoxia may play an important role in the pathogenesis of centrilobular liver disease.
The Development of Human Fetal Eye Movement Patterns
Authors: Birnholz Jason C.
Published: October 2006

The eye can be visualized ultrasonically in more than 90 percent of fetuses 16 through 42 weeks of gestational age. Slow eye movements are present by 16 weeks. Rapid eye movements begin at 23 weeks and become more frequent between 24 and 35 weeks. Eye inactivity becomes more common after 36 weeks and is associated with sustained diaphragmatic excursions implying a "quiet sleep" state. Pathologic eye movements were seen in four fetuses with dysmorphic brain structure.
Phenomenological Space-Time: Toward an Experiential Relativity
Authors: DeLong Alton J.
Published: October 2006

Subjects observing differently scaled environments undergo systematic shifts in the experience of time. The experience of temporal duration is compressed relative to the clock in the same proportion as scale-model environments being observed are compressed relative to the full-sized environment. This research suggests that spatial scale may be a principal mediator in the experience of time.
Magnetic Material in the Head of the Common Pacific Dolphin
Authors: Zoeger J. , Dunn J. R. , Fuller M.
Published: October 2006

Magnetic material carrying natural remanent magnetization is present in the head of the common Pacific dolphin (Delphinus delphis). A sample of this material, isolated from the dura mater, has a moment of 2 × 10
-5
gauss-cubic centimeter. The presence of such strongly magnetized material suggests that it may play a navigational role.
Cardiac Sarcolemma: Compositional Adaptation to Exercise
Authors: Tibbits Glen F. , Nagatomo Takafumi , Sasaki Miyuki , Barnard R. James
Published: October 2006

Marked changes were observed in the lipid composition of highly purified plasma membranes isolated from the hearts of rats subjected to daily treadmill running. Compared to sedentary controls, sarcolemmal content of total phospholipid and phosphatidylserine in the trained group was increased 23 and 50 percent, respectively. This observation suggests a mechanism by which cardiac contractility may be enhanced by exercise.
Trauma-Induced Protein in Rat Tissues: A Physiological Role for a "Heat Shock" Protein?
Authors: Currie R. W. , White F. P.
Published: October 2006

Hyperthermic shock induces the synthesis of a novel protein (P
71
) in many rat tissues in vivo. In incubated rat tissue slices P
71
is the major protein synthesized even though it is undetectable in the tissues of a normal, unstressed rat. P
71
is a "heat shock" protein, and it may be induced in vivo by stimuli other than hyperthermia. These results indicate that caution must be used in studies of protein synthesis in tissue explants, since the pattern of proteins synthesized by rat tissue slices is characteristic of stressed tissue.
Similar Amino Acid Sequences: Chance or Common Ancestry?
Authors: Doolittle Russell F.
Published: October 2006

The systematic comparison of every newly determined amino acid sequence with all other known sequences may allow a complete reconstruction of the evolutionary events leading to contemporary proteins. But sometimes the surviving similarities are so vague that even computer-based sequence comparison procedures are unable to validate relationships. In other cases similar sequences may appear in totally alien proteins as a result of mere chance or, occasionally, by the convergent evolution of sequences with special properties.
Sulfhydryl Compounds May Mediate Gastric Cytoprotection
Authors: Szabo Sandor , Trier Jerry S. , Frankel Paul W.
Published: October 2006

Ethanol induces hemorrhagic gastric erosions and causes a dose-dependent decrease in the concentration of nonprotein sulfhydryl compounds in rat gastric mucosa. Sulfhydryl-containing drugs protect rats from ethanol-induced gastric erosions, whereas sulfhydryl blocking agents counteract the mucosal cytoprotective effect of prostaglandin F
2β
. These observations suggest that endogenous nonprotein sulfhydryls may mediate prostaglandin-induced gastric cytoprotection and that sulfhydryl drugs may have potential for preventing or treating hemorrhagic gastric erosions.
Direct Electrical Connections Between Transient Amacrine Cells in the Catfish Retina
Authors: Naka Ken Ichi , Christensen Burgess N.
Published: October 2006

Transient amacrine cells were identified by their intracellularly recorded response to flashes of light. These cells typically respond with a transient depolarization, often followed by a steady-state response during the stimulus. When two electrodes were placed in different transient amacrine cells, current of either polarity passed through one electrode produced a steady-state voltage change that was recorded by the electrode in the nearby cell. Following identification of the physiological type, transient amacrine cells were injected with horseradish peroxidase and the tissue was processed for light and electron microscopy. Both conventional chemical synaptic junctions and gap junctions were found to connect amacrine cells.
Effect of Indomethacin on Intestinal Tumors Induced in Rats by the Acetate Derivative of Dimethylnitrosamine
Authors: Pollard Morris , Luckert Phyllis H.
Published: October 2006

Over the course of 20 weeks, Sprague-Dawley rats developed intestinal tumors in response to an intraperitoneal injection of the acetate derivative of dimethylnitrosamine. The same agent did not induce tumors in Lobund-Wistar rats. The number of tumors was significantly smaller in rats given drinking water containing indomethacin (beginning 14 days after the injections) than in control rats given drug-free water.
Radioactive Plume from the Three Mile Island Accident: Xenon-133 in Air at a Distance of 375 Kilometers
Authors: Wahlen Martin , Kunz Charles O. , Matuszek John M. , Mahoney William E. , Thompson Roger C.
Published: October 2006

The transit of an air mass containing radioactive gas released from the Three Mile Island reactor was recorded in Albany, New York, by measuring xenon-133. These measurements provide an evaluation of Three Mile Island effluents to distances greater than 100 kilometers. Two independent techniques identified xenon-133 in ambient air at concentrations as high as 3900 picocuries per cubic meter. The local γ-ray whole-body dose from the passing radioactivity amounted to 0.004 millirem, or 0.004 percent of the annual dose from natural sources.
Behavioral Responses to Artificial Food Colors
Authors: Weiss Bernard , Williams J. Hicks , Margen Sheldon , Abrams Barbara , Caan Bette , Citron L. Jay , Cox Christopher , McKibben Jane , Ogar Dale , Schultz Stephen
Published: October 2006

Twenty-two young children, maintained on a diet that excluded certain foods, were challenged intermittently with a blend of seven artificial colors in a double-blind trial. Parents' observations provided the criteria of response. One child that responded mildly to the challenge and one that responded dramatically were detected. The latter, a 34-month-old female, showed a significant increase in aversive behaviors. These results further confirm previous controlled studies.
A Nonadrenergic Vagal Inhibitory Pathway to Feline Airways
Authors: Diamond Louis , O'Donnell Margaret
Published: October 2006

In cats anesthetized with chloralose-pentobarbital and artificially ventilated, electrical stimulation of the caudal end of the cut cervical vagus nerve has a biphasic effect on the bronchoconstriction induced by an intravenous infusion of serotonin. The response consists of a brief augmentation of bronchoconstriction followed by relatively prolonged bronchodilation. After muscarinic receptor blockade with atropine, vagal stimulation causes only bronchodilation. Vagally mediated bronchodilation is not affected by beta adrenergic blockade with propranolol, alpha adrenergic blockade with phenoxybenzamine, or adrenergic neuronal blockade with guanethidine, but is abolished by autonomic ganglionic blockade with hexamethonium. These findings support the conclusion that a nonadrenergic inhibitory nervous system is present in the pulmonary airways of the cat and that the system is supplied by preganglionic fibers in the cervical vagus nerves.
Sexual Characteristics of Adult Female Mice Are Correlated with Their Blood Testosterone Levels During Prenatal Development
Authors: vom Saal Frederick S. , Bronson F. H.
Published: October 2006

Mice produce litters containing many pups, and the female fetuses that develop between male fetuses have significantly higher concentrations of the male sex steroid testosterone in both their blood and amniotic fluid than do females that develop between other female fetuses. These two types of females differ during later life in many sexually related characteristics. Thus, individual variation in sexual characteristics of adult female mice may be traceable to differential exposure to testosterone during prenatal development because of intrauterine proximity to male fetuses.
A Disparity Gradient Limit for Binocular Fusion
Authors: Burt Peter , Julesz Bela
Published: October 2006

Ever since Panum, it has been commonly assumed that there is an absolute disparity limit for binocular fusion. It is now found that nearby objects modify this disparity limit. This result sheds new light on several enigmatic phenomena in stereopsis.
Telemetered Electromyography of Forelimb Muscle Chains in Gibbons (
Hylobates lar
)
Authors: Jungers William L. , Stern Jack T.
Published: October 2006

Electromyographic studies of brachiation in the gibbon controvert deductions, based on dissection, about the purported functions of muscle chains in the hylobatid forelimb. Neither force conduction distally along the components of the chains nor simultaneity of muscular contraction occurs in brachiation. Rather, the unique structure of the forelimb is probably the result of evolved changes in the short head of biceps brachii to enhance its role as a forearm flexor.
Of Human Bonding: Newborns Prefer Their Mothers' Voices
Authors: DeCasper Anthony J. , Fifer William P.
Published: October 2006

By sucking on a nonnutritive nipple in different ways, a newborn human could produce either its mother's voice or the voice of another female. Infants learned how to produce the mother's voice and produced it more often than the other voice. The neonate's preference for the maternal voice suggests that the period shortly after birth may be important for initiating infant bonding to the mother.
An About 50,000-Dalton Protein in Adrenal Medulla: a Common Precursor of [Met]- and [Leu]Enkephalin
Authors: Lewis Randolph V. , Stern Alvin S. , Kimura Sadao , Rossier Jean , Stein Stanley , Udenfriend Sidney
Published: October 2006

A protein that may be an enkephalin precursor has been identified in extracts of bovine adrenal medulla. This protein (about 50,000 daltons) appears to contain seven copies of [Met]enkephalin and one copy of [Leu]enkephalin. Digestion with trypsin and carboxypeptidase B yields [Met]enkephalin and [Leu]enkephalin in a ratio of almost 7 to 1. The enkephalins were identified by chromatography and by their binding to opiate receptors. Some characteristics of several other adrenal peptides that may serve as intermediates in the biosynthesis of the enkephalins are presented.
Behavioral and Physiological Evidence of Sexual Climax in the Female Stump-Tailed Macaque (
Macaca arctoides
)
Authors: Goldfoot D. A. , Westerborg-van Loon H. , Groeneveld W. , Slob A. K.
Published: October 2006

Intense tonic/clonic uterine contractions and sudden increases in heart rate coincided with the behavioral homolog of a male ejaculatory response (minus seminal emission) in a normal female stump-tailed macaque engaged in homosexual mounting episodes. The behavioral patterns were also observed in four of ten females during 5 to 40 percent of heterosexual copulations. These observations demonstrate the existence of an orgasmic response in a nonhuman primate.
Contextual Effects in Infant Speech Perception
Authors: Eimas Peter D. , Miller Joanne L.
Published: October 2006

Infants, aged 2 to 4 months, discriminated synthetic speech patterns that varied in duration of the formant transitions; this variation provides information sufficient to signal the phonetic distinction between a stop consonant and a semivowel in adult listeners. In addition, the discriminability of a given difference in transition duration was a function of both the particular stimulus values and the total duration of the syllable. This contextual effect occurred even though the information for syllable duration came after the transition information. The obtained pattern of discontinuous discriminability was in accord with perception that is relational and categorical.
Altering Genotype and Phenotype by DNA-Mediated Gene Transfer
Authors: Pellicer Angel , Robins Diane , Wold Barbara , Sweet Ray , Jackson James , Lowy Israel , Roberts James Michael , Sim Gek Kee , Silverstein Saul , Axel Richard
Published: October 2006

Transformation, or DNA-mediated gene transfer, permits the introduction of new genetic information into a cell and frequently results in a change in phenotype. The transforming DNA is ultimately integrated into a recipient cell chromosome. No unique chromosomal locations are apparent; different lines contain the transforming DNA on different chromosomes. Expression of transformed genes frequently results in the synthesis of new polypeptide products which restore appropriate mutant cells to the wild-type phenotype. Thus transformation provides an in vivo assay for the functional role of DNA sequence organization about specific genes. Transforming genes coding for selectable functions, such as adenine phosphoribosyltransferase or thymidine kinase, have now been isolated by utilizing transformation in concert with molecular cloning. Finally, transformation may provide a general approach to the analysis of complex heritable phenotypes by permitting the distinction between phenotypic changes without concomitant changes in DNA and functional genetic rearrangements.
Changes in Endolymphatic Potential and Crossed Olivocochlear Bundle Stimulation Alter Cochlear Mechanics
Authors: Mountain David C.
Published: October 2006

Mechanical nonlinearity in the cochlea produces acoustic distortion products that can be measured in the ear canal. These distortion products can be altered by changes in the endolymphatic potential as well as by stimulation of the crossed olivocochlear bundle, which provides efferent innervation to cochlear hair cells.
Swelling of Nerve Fibers Associated with Action Potentials
Authors: Iwasa Kunihiko , Tasaki Ichiji , Gibbons Robert C.
Published: October 2006

Swelling of nerve fibers during the action potential was demonstrated by three different methods. Generation of a propagated nerve impulse in a crab nerve produced an outward movement of 50 to 100 angstroms of the nerve surface and a rise in swelling pressure on the order of 5 dynes per square centimeter. In squid giant axons, the amplitude of the observed outward movement of the surface was small.
Temporal Precision in Circadian Systems: A Reliable Neuronal Clock from Unreliable Components?
Authors: Enright J. T.
Published: October 2006

Mutual coupling among oscillators of an ensemble has been proposed to explain the precision of some circadian rhythms. Reciprocal triggering is one of the most familiar forms of mutual coupling in nervous systems, but it can at best produce only modest improvement in temporal precision. Nevertheless, models with an elementary elaboration of such coupling show that circadian precision could be derived from oscillators that are intrinsically "sloppy"; sufficient conditions are that output of the individual components be summed and that mutual triggering be mediated by a nonlinear phenomenon, such as a threshold.
Have Tar and Nicotine Yields of Cigarettes Changed?
Authors: Kozlowski Lynn T. , Rickert W. S. , Robinson J. C. , Grunberg Neil E.
Published: October 2006

In official assays of the tar and nicotine yields of 12 popular brands of cigarettes, smoking machines took fewer puffs, on the average, in 1974 than in 1969. The decline in puffs appears to have been a major cause of the reported reductions in tar and nicotine yields during this period.
Limulus
Brain Modulates the Structure and Function of the Lateral Eyes
Authors: Barlow Robert B. , Chamberlain Steven C. , Levinson John Z.
Published: October 2006

At night efferent optic nerve activity generated by a circadian clock in the
Limulus
brain changes the structure of the photoreceptor and surrounding pigment cells in the animal's lateral eyes. The structural changes allow each ommatidium to gather light from a wider area at night than during the day. Visual sensitivity is thereby increased, but spatial resolution is diminished. At daybreak efferent activity from the clock stops, the structural changes reverse, and the field of view of each ommatidium decreases. The cyclic changes are endogenous and continue in the dark. Thus, under the control of a circadian clock, the
Limulus
eye exchanges its daytime acuity for greater sensitivity at night.
Light Suppresses Melatonin Secretion in Humans
Authors: Lewy Alfred J. , Wehr Thomas A. , Goodwin Frederick K. , Newsome David A. , Markey S. P.
Published: October 2006

Bright artificial light suppressed nocturnal secretion of melatonin in six normal human subjects. Room light of less intensity, which is sufficient to suppress melatonin secretion in other mammals, failed to do so in humans. In contrast to the results of previous experiments in which ordinary room light was used, these findings establish that the human response to light is qualitatively similar to that of other mammals.
Relation of Mammalian Sperm Chromatin Heterogeneity to Fertility
Authors: Evenson D. P. , Darzynkiewicz Z. , Melamed M. R.
Published: October 2006

Flow cytometry of heated sperm nuclei revealed a significant decrease in resistance to in situ denaturation of spermatozoal DNA in samples from bulls, mice, and humans of low or questionable fertility when compared with others of high fertility. Since thermal denaturation of DNA in situ depends on chromatin structure, it is assumed that changes in sperm chromatin conformation may be related to the diminished fertility. Flow cytometry of heated sperm nuclei may provide a new and independent determinant of male fertility.
Mutagenicity of Fly Ash Particles in
Paramecium
Authors: Smith-Sonneborn J. , Palizzi R. A. , Herr C. , Fisher G. L.
Published: October 2006

Paramecium
, a protozoan that ingests nonnutritive particulate matter, was used to determine the mutagenicity of fly ash. Heat treatment inactivated mutagens that require metabolic conversion to their active form but did not destroy all mutagenicity. Extraction of particles with hydrochloric acid, but not dimethyl sulfoxide, removed detectable mutagenic activity.
The Framing of Decisions and the Psychology of Choice
Authors: Tversky Amos , Kahneman Daniel
Published: October 2006

The psychological principles that govern the perception of decision problems and the evaluation of probabilities and outcomes produce predictable shifts of preference when the same problem is framed in different ways. Reversals of preference are demonstrated in choices regarding monetary outcomes, both hypothetical and real, and in questions pertaining to the loss of human lives. The effects of frames on preferences are compared to the effects of perspectives on perceptual appearance. The dependence of preferences on the formulation of decision problems is a significant concern for the theory of rational choice.
Characterization of a Pathway for Ciliary Neurotrophic Factor Signaling to the Nucleus
Authors: Bonni Azad , Frank David A. , Schindler Chris , Greenberg Michael E.
Published: October 2006

Components of a signaling pathway that couples the ciliary neurotrophic factor (CNTF) receptor to induction of transcription were identified. CNTF stimulated the tyrosine phosphorylation of p91, a protein implicated in interferon signaling pathways, and of two proteins that are distinct but related to p91. Tyrosine-phosphorylated p91 translocated to the nucleus, where p91 and p91-related proteins bound to a DNA sequence found in promoters of genes responsive to CNTF. This DNA sequence, when inserted upstream of a reporter gene, conferred a transcriptional response to CNTF. A pathway that transduces interferon signals may therefore have a more general function in the propagation of responses to certain neurotrophic factors.
Diphytanyl and Dibiphytanyl Glycerol Ether Lipids of Methanogenic Archaebacteria
Authors: Tornabene Thomas G. , Langworthy Thomas A.
Published: October 2006

The lipids of nine different methanogenic bacterial strains are comprised of diphytanyl glycerol diethers, previously known only in extremely halophilic bacteria, as well as dibiphytanyl diglycerol tetraethers, known formerly only in the extremely thermoacidophilic bacteria
Thermoplasma
and
Sulfolobus
. Of the methanogens examined from four representative taxonomic groups,
Methanobacterium
and
Methanospirillum
contained both types of isopranyl ethers in nearly equal proportions, whereas the coccal forms,
Methanosarcina
and
Methanococcus
, possessed diphytanyl glycerol diethers, but with only a trace of or no dibiphytanyl diglycerol tetraethers. The occurrence of both types of isopranyl glycerol ethers in methanogenic bacteria supports the proposal that they have a close genealogical relationship to the extremely halophilic and thermoacidophilic bacteria.
Catechol-
O
-Methyltransferase: Thermolabile Enzyme in Erythrocytes of Subjects Homozygous for Allele for Low Activity
Authors: Scanlon Paul D. , Raymond Fredrick A. , Weinshilboum Richard M.
Published: October 2006

Low catechol-
O
-methyltransferase (COMT) activity (< 8 units per milliliter) in the human erythrocyte is inherited as an autosomal recessive trait (COMT
L
). The average half-life of COMT in erythrocyte lysates incubated at 48°C was significantly shorter in lysates from three subjects with low enzyme activity than in lysates from three subjects with high enzyme activity (12.5 ± 0.9 minutes compared with 21.2 ± 1.4 minutes, P < .01). When the ratios of COMT activities in lysates heated at 48°C for 15 minutes to enzyme activities in unheated samples were used as a measure of enzyme thermostability in blood samples from 316 randomly selected subjects, the ratios were significantly less for subjects with low enzyme activity than for subjects with higher enzyme activity. The presence of thermolabile COMT in blood of individuals homozygous for COMT
L
raises the possibility that the locus COMT may represent the structural gene for the human enzyme.
Harmonic-sensitive Neurons in the Auditory Cortex of the Mustache Bat
Authors: Suga Nobuo , O'Neill William E. , Manabe Toshiki
Published: October 2006

Human speech and animal sounds contain phonemes with prominent and meaningful harmonics. The biosonar signals of the mustache bat also contain up to four harmonics, and each consists of a long constant-frequency component followed by a short frequency-modulated component. Neurons have been found in a large cluster within auditory cortex of this bat whose responses are facilitated by combinations of two or more harmonically related tones. Moreover, the best frequencies for excitation of these neurons are closely associated with the constant-frequency components of the biosonar signals. The properties of these neurons make them well suited for identifying the signals produced by other echolocating mustache bats. They also show how meaningful components of sound are assembled by neural circuits in the central nervous system and suggest a method by which sounds with important harmonics (or formants) may be detected and recognized by the brain in other species, including humans.
The Cloning of PIG-A, a Component in the Early Step of GPI-Anchor Biosynthesis
Authors: Miyata Toshio , Takeda Junji , Iida Yoshiyasu , Yamada Norio , Inoue Norimitsu , Takahashi Minoru , Maeda Kenji , Kitani Teruo , Kinoshita Taroh
Published: October 2006

The glycosylphosphatidylinositol (GPI) anchor is a membrane attachment structure of many proteins and occurs in a wide variety of eukaryotes from yeasts to mammals. The structure of the core of the GPI anchor is conserved in protozoa and mammals and so is its biosynthetic pathway. A complementary DNA encoding a human protein termed PIG-A (phosphatidylinositol glycan-class A) was cloned. PIG-A was necessary for synthesis of
N
-acetylglucosaminyl-phosphatidylinositol, the very early intermediate in GPI-anchor biosynthesis.
Activation of a Phosphotyrosine Phosphatase by Tyrosine Phosphorylation
Authors: Vogel Wolfgang , Lammers Reiner , Huang Jiaoti , Ullrich Axel
Published: October 2006

Regulation of cell proliferation, differentiation, and metabolic homeostasis is associated with the phosphorylation and dephosphorylation of specific tyrosine residues of key regulatory proteins. The phosphotyrosine phosphatase 1D (PTP 1D) contains two amino terminally located Src homology 2 (SH2) domains and is similar to the
Drosophila corkscrew
gene product, which positively regulates the
torso
tyrosine kinase signal transduction pathway. PTP activity was found to be regulated by physical interaction with a protein tyrosine kinase. PTP 1D did not dephosphorylate receptor tyrosine kinases, despite the fact that it associated with the epidermal growth factor receptor and chimeric receptors containing the extracellular domain of the epidermal growth factor receptor and the cytoplasmic domain of either the HER2-
neu
,
kit
-SCF, or platelet-derived growth factor β (βPDGF) receptors. PTP 1D was phosphorylated on tyrosine in cells overexpressing the βPDGF receptor kinase and this tyrosine phosphorylation correlated with an enhancement of its catalytic activity. Thus, protein tyrosine kinases and phosphatases do not simply oppose each other's action; rather, they may work in concert to maintain a fine balance of effector activation needed for the regulation of cell growth and differentiation.
Natural Selection and the Origin of
jingwei
, a Chimeric Processed Functional Gene in
Drosophila
Authors: Long Manyuan , Langley Charles H.
Published: October 2006

The origin of new genes includes both the initial molecular events and subsequent population dynamics. A processed
Drosophila
alcohol dehydrogenase (
Adh
) gene, previously thought to be a pseudogene, provided an opportunity to examine the two phases of the origin of a new gene. The sequence of the processed
Adh
messenger RNA became part of a new functional gene by capturing several upstream exons and introns of an unrelated gene. This novel chimeric gene,
jingwei
, differs from its parent
Adh
gene in both its pattern of expression and rate of molecular evolution. Natural selection participated in the origin and subsequent evolution of this gene.
A Single Phosphotyrosine Residue of Stat91 Required for Gene Activation by Interferon-γ
Authors: Shuai Ke , Stark George R. , Kerr lan M. , Darnell James E.
Published: October 2006

Interferon-γ (IFN-γ) stimulates transcription of specific genes by inducing tyrosine phosphorylation of a 91-kilodalton cytoplasmic protein (termed STAT for signal transducer and activator of transcription). Stat91 was phosphorylated on a single site (Tyr
701
), and phosphorylation of this site was required for nuclear translocation, DNA binding, and gene activation. Stat84, a differentially spliced product of the same gene that lacks the 38 carboxyl-terminal amino acids of Stat91, did not activate transcription, although it was phosphorylated and translocated to the nucleus and bound DNA. Thus, Stat91 mediates activation of transcription in response to IFN-γ.
Substances Moved by Axonal Transport and Released by Nerve Stimulation Have an Innervation-Like Effect on Muscle
Authors: Younkin S. G. , Brett R. S. , Davey B. , Younkin L. H.
Published: October 2006

Substances which have an innervation-like effect on the cholinesterase activity of organ-cultured rat extensor digitorum longus muscles are moved in nerve by axonal transport, are released from nerve by stimulation, and are present in innervated muscle but apparently absent from denervated muscle. Substances which increase the acetylcholine sensitivity of cultured muscles behave similarly.
T Cell Activation Antigen, CD26, as a Cofactor for Entry of HIV in CD4
+
Cells
Authors: Callebaut Christian , Krust Bernard , Jacotot Etienne , Hovanessian Ara G.
Published: October 2006

The CD4 molecule is essential for binding HIV particles, but is not sufficient for efficient viral entry and infection. The cofactor was shown to be dipeptidyl peptidase IV (DPP IV), also known as CD26. This serine protease cleaves its substrates at specific motifs; such motifs are also highly conserved in the V3 loops of HIV-1, HIV-2, and related simian isolates. Entry of HIV-1 or HIV-2 into T lymphoblastoid and monocytoid cell lines was inhibited by a specific monoclonal antibody against DPP IV or specific peptide inhibitors of this protease. Coexpression of human CD4 and CD26 in murine NIH 3T3 cells rendered them permissive to infection by HIV-1 and HIV-2. These observations could provide the basis for developing simple and specific inhibitors of HIV and open a possibility for vaccine development.
Selectivity in Signal Transduction Determined by γ Subunits of Heterotrimeric G Proteins
Authors: Kleuss Christiane , Scherübl Hans , Hescheler Jürgen , Schultz Günter , Wittig Burghardt
Published: October 2006

Various heterotrimeric guanine nucleotide-binding proteins have been identified on the basis of the individual subtypes of their α subunits. The βγ complexes, composed of β and γ subunits, remain tightly associated under physiological conditions and have been assumed to constitute a common pool shared among various guanosine triphosphate (GTP)-binding (G) protein heterotrimers. Particular α and β subunit subtypes participate in the signal transduction processes between somatostatin or muscarinic receptors and the voltage-sensitive L-type calcium channel in rat pituitary GH
3
cells. Among γ subunits the γ
3
subtype was found to be required for coupling of the somatostatin receptor to voltage-sensitive calcium channels, whereas the γ
4
subtype was found to be required for coupling of the muscarinic receptor to those channels.
Altered Prevalence of Gating Modes in Neurotransmitter Inhibition of N-Type Calcium Channels
Authors: Delcour Anne H. , Tsien Richard W.
Published: October 2006

G protein-mediated inhibition of voltage-activated calcium channels by neurotransmitters has important consequences for the control of synaptic strength. Single-channel recordings of N-type calcium channels in frog sympathetic neurons reveal at least three distinct patterns of gating, designated low-
P
o
, medium-
P
o
, and high-
P
o
modes according to their probability of being open (
P
o
) at -10 millivolts. The high-
P
o
mode is responsible for the bulk of divalent cation entry in the absence of neurotransmitter. Norepinephrine greatly decreased the prevalence of high-
P
o
gating and increased the proportion of time a channel exhibited low-
P
o
behavior or no activity at all, which thereby reduced the overall current. Directly observed patterns of transition between the various modes suggest that activated G protein alters the balance between modal behaviors that freely interconvert even in the absence of modulatory signaling.
Regulation of CREB Phosphorylation in the Suprachiasmatic Nucleus by Light and a Circadian Clock
Authors: Ginty David D. , Kornhauser Jon M. , Thompson Margaret A. , Bading Hilmar , Mayo Kelly E. , Takahashi Joseph S. , Greenberg Michael E.
Published: October 2006

Mammalian circadian rhythms are regulated by a pacemaker within the suprachiasmatic nuclei (SCN) of the hypothalamus. The molecular mechanisms controlling the synchronization of the circadian pacemaker are unknown; however, immediate early gene (IEG) expression in the SCN is tightly correlated with entrainment of SCN-regulated rhythms. Antibodies were isolated that recognize the activated, phosphorylated form of the transcription factor cyclic adenosine monophosphate response element binding protein (CREB). Within minutes after exposure of hamsters to light, CREB in the SCN became phosphorylated on the transcriptional regulatory site, Ser
133
. CREB phosphorylation was dependent on circadian time: CREB became phosphorylated only at times during the circadian cycle when light induced IEG expression and caused phase shifts of circadian rhythms. These results implicate CREB in neuronal signaling in the hypothalamus and suggest that circadian clock gating of light-regulated molecular responses in the SCN occurs upstream of phosphorylation of CREB.
Fossils and the Mosaic Nature of Human Evolution
Authors: McHenry Henry M,
Published: October 2006

These new fossils, dates, analyses, and interpretations lead to confirmation and refinement of the mosaic scheme of human evolution as proposed by early evolutionists such as Lamarck, Haeckel, and Darwin. Evolutionary changes in the body adapting our ancestors to bipedalism occurred before 3 million years ago, judging by the completeness of the adaptation in the late Pliocene-early Pleistocene hominids. The skeletons of these early hominids were not identical to those of modern humans, but locomotor behavior was probably human. At about 3 million years ago their brains were relatively small, although internal reorganization may have been taking place. By 2 million years ago a wider range of variation in brain size appears in the fossil record, with an average size somewhat larger than that in earlier hominids. Concomitant with this beginning of brain size increase was the reshaping of the pelvic region, perhaps related to an increase in birth canal size to accommodate larger-brained fetuses. Evidence for tool manufacturing, meat eating, shelter building, and probably food sharing also occurs at about this time, which signals the coming of a new adaptive strategy.
Dyskinesias Elicited by Methamphetamine: Susceptibility of Former Methadone-Consuming Monkeys
Authors: Eibergen Robert D. , Carlson Kristin R.
Published: October 2006

Rhesus monkeys with a history of drinking methadone but currently drug-free and control monkeys with no drug history were injected with methamphetamine hydrochloride (2 to 5 milligrams per kilogram of body weight). In six of seven monkeys which had consumed methadone the lowest dose immediately elicited pronounced oral dyskinesias virtually identical to those of human tardive dyskinesia. The control monkeys did not exhibit oral dyskinesias even after prolonged treatment with the highest dose. The clinical implications may be related to the functioning of brain dopaminergic systems.
Inhibition by Anions of Human Red Cell Carbonic Anhydrase B: Physiological and Biochemical Implications
Authors: Maren Thomas H. , Rayburn Catherine S. , Liddell Norman E.
Published: October 2006

The hydration rate of CO
2
catalyzed by human red cell carbonic anhydrase B is 92 percent reduced by the normal concentrations of chloride and bicarbonate in red cells. This reflects a general sensitivity of this reaction to halides and other anions, up to 87 times greater than the effect on red cell carbonic anhydrase C. The catalytic hydration of CO
2
is generally more (up to 24 times) sensitive to inhibition by anions and sulfonamides than the dehydration of HCO
3
-, probably reflecting different mechanisms. The sensitivity of enzyme B to anion inhibition also depends upon the substrate, being much greater for CO
2
than for certain esters. On the basis of the very low catalytic activity of B for CO
2
in the presence of physiological concentration of chloride, and the fact that carbonic anhydrase C is effective for CO
2
hydration (in the presence of chloride) at a rate 340 times greater than that of CO
2
output from tissues, it appears that the biological role of enzyme B is not that of a carbonic anhydrase.
Ordered Restriction Maps of
Saccharomyces cerevisiae
Chromosomes Constructed by Optical Mapping
Authors: Schwartz David C. , Li Xiaojun , Hernandez Luis I. , Ramnarain Satyadarshan P. , Huff Edward J. , Wang Yu-Ker
Published: October 2006

A light microscope-based technique for rapidly constructing ordered physical maps of chromosomes has been developed. Restriction enzyme digestion of elongated individual DNA molecules (about 0.2 to 1.0 megabases in size) was imaged by fluorescence microscopy after fixation in agarose gel. The size of the resulting individual restriction fragments was determined by relative fluorescence intensity and apparent molecular contour length. Ordered restriction maps were then created from genomic DNA without reliance on cloned or amplified sequences for hybridization or analytical gel electrophoresis. Initial application of optical mapping is described for
Saccharomyces cerevisiae
chromosomes.
Abnormal Behavior Associated with a Point Mutation in the Structural Gene for Monoamine Oxidase A
Authors: Brunner H. G. , Nelen M. , Breakefield X. O. , Ropers H. H. , van Oost B. A.
Published: October 2006

Genetic and metabolic studies have been done on a large kindred in which several males are affected by a syndrome of borderline mental retardation and abnormal behavior. The types of behavior that occurred include impulsive aggression, arson, attempted rape, and exhibitionism. Analysis of 24-hour urine samples indicated markedly disturbed monoamine metabolism. This syndrome was associated with a complete and selective deficiency of enzymatic activity of monoamine oxidase A (MAOA). In each of five affected males, a point mutation was identified in the eighth exon of the MAOA structural gene, which changes a glutamine to a termination codon. Thus, isolated complete MAOA deficiency in this family is associated with a recognizable behavioral phenotype that includes disturbed regulation of impulsive aggression.
Microdomains with High Ca
2+
Close to IP
3
-Sensitive Channels that Are Sensed by Neighboring Mitochondria
Authors: Rizzuto Rosario , Brini Marisa , Murgia Marta , Pozzan Tullio
Published: October 2006

Microdomains of high intracellular calcium ion concentration, [Ca
2+
]
i
, have been hypothesized to occur in living cells exposed to stimuli that generate inositol 1,4,5-trisphosphate (IP
3
). Mitochondrially targeted recombinant aequorin was used to show that IP
3
-induced Ca
2+
mobilization from intracellular stores caused increases of mitochondrial Ca
2+
concentration, [Ca
2+
]
m
, the speed and amplitude of which are not accounted for by the relatively small increases in mean [Ca
2+
]
i
. A similar response was obtained by the addition of IP
3
to permeabilized cells but not by perfusion of cells with Ca
2+
at concentrations similar to those measured in intact cells. It is concluded that in vivo, domains of high [Ca
2+
]
i
are transiently generated close to IP
3
-gated channels and sensed by nearby mitochondria; this may provide an efficient mechanism for optimizing mitochondrial activity upon cell stimulation.
Multifactorial Nature of Human Immunodeficiency Virus Disease: Implications for Therapy
Authors: Fauci Anthony S.
Published: October 2006

The immunopathogenic mechanisms underlying human immunodeficiency virus (HIV) disease are extremely complex; the disease process is multifactorial with multiple overlapping phases. Viral burden is substantial and viral replication occurs throughout the entire course of HIV infection. Inappropriate immune activation and elevated secretion of certain cytokines compound the pathogenic process. Profound immunosuppression ultimately occurs together with a disruption of the microenvironment of the immune system, which is probably unable to regenerate spontaneously. Thus, therapeutic strategies in HIV disease must not be unidimensional, but rather must be linked to the complex pathogenic components of the disease and must address where feasible each of the recognized pathogenic processes for the possibility of therapeutic intervention.
Rice Prolamine Protein Body Biogenesis: A BiP-Mediated Process
Authors: Li Xingxiang , Wu Yujia , Zhang Dian-Zhong , Gillikin Jeffrey W. , Boston Rebecca S. , Franceschi Vincent R. , Okita Thomas W.
Published: October 2006

Rice prolamines are sequestered within the endoplasmic reticulum (ER) lumen even though they lack a lumenal retention signal. Immunochemical and biochemical data show that BiP, a protein that binds lumenal polypeptides, is localized on the surface of the aggregated prolamine protein bodies (PBs). BiP also forms complexes with nascent chains of prolamines in polyribosomes and with free prolamines with distinct adenosine triphosphate sensitivities. Thus, BiP retains prolamines in the lumen by facilitating their folding and assembly into PBs.
Modulation of Calmodulin Plasticity in Molecular Recognition on the Basis of X-Ray Structures
Authors: Meador William E. , Means Anthony R. , Quiocho Florante A.
Published: October 2006

Calmodulin is the primary calcium-dependent signal transducer and regulator of a wide variety of essential cellular functions. The structure of calcium-calmodulin bound to the peptide corresponding to the calmodulin-binding domain of brain calmodulin-dependent protein kinase IIα was determined to 2 angstrom resolution. A comparison to two other calcium-calmodulin structures reveals how the central helix unwinds in order to position the two domains optimally in the recognition of different target enzymes and clarifies the role of calcium in maintaining recognition-competent domain structures.
Interleukin-2 Receptor γ Chain: a Functional Component of the Interleukin-4 Receptor
Authors: Russell Sarah M. , Keegan Achsah D. , Harada Nobuyuki , Nakamura Yoshiaki , Noguchi Masayuki , Leland Pamela , Friedmann Michael C. , Miyajima Atsushi , Puri Raj K. , Paul William E. , Leonard Warren J.
Published: October 2006

The interleukin-2 (IL-2) receptor γ chain (IL-2Rγ) is an essential component of high- and intermediate-affinity IL-2 receptors. IL-2Rγ was demonstrated to be a component of the IL-4 receptor on the basis of chemical cross-linking data, the ability of IL-2Rγ to augment IL-4 binding affinity, and the requirement for IL-2Rγ in IL-4-mediated phosphorylation of insulin receptor substrate-1. The observation that IL-2Rγ is a functional component of the IL-4 receptor, together with the finding that IL-2Rγ associates with the IL-7 receptor, begins to elucidate why deficiency of this common γ chain (gamma;
c
) has a profound effect on lymphoid function and development, as seen in X-linked severe combined immunodeficiency.
Inhibition of Transcriptional Regulator Yin-Yang-1 by Association with c-Myc
Authors: Shrivastava A. , Saleque S. , Kalpana G. V. , Artandi S. , Goff S. P. , Calame K.
Published: October 2006

Yin-Yang-1 (YY1) regulates the transcription of many genes, including the oncogenes c-
fos
and c-
myc
. Depending on the context, YY1 acts as a transcriptional repressor, a transcriptional activator, or a transcriptional initiator. The yeast two-hybrid system was used to screen a human complementary DNA (cDNA) library for proteins that associate with YY1, and a c-
myc
cDNA was isolated. Affinity chromatography confirmed that YY1 associates with c-Myc but not with Max. In cotransfections, c-Myc inhibits both the repressor and the activator functions of YY1, which suggests that one way c-Myc acts is by modulating the activity of YY1.
Crystal Structure of the Repetitive Segments of Spectrin
Authors: Yan Y. , Winograd E. , Viel A. , Cronin T. , Harrison S. C. , Branton D.
Published: October 2006

The elongated proteins of the spectrin family (dystrophin, α-actinin, and spectrin) contain tandemly repeated segments and form resilient cellular meshworks by cross-linking actin filaments. The structure of one of the repetitive segments of α-spectrin was determined at a 1.8 angstrom resolution. A segment consists of a three-helix bundle. A model of the interface between two tandem segments suggests that hydrophobic interactions between segments may constrain intersegment flexibility. The helix side chain interactions explain how mutations that are known to produce hemolytic anemias disrupt spectrin associations that sustain the integrity of the erythrocyte membrane.