bluuebunny/crossref_metadata_2025 huggingface dataset:
Transformation of Bloom's Syndrome Fibroblasts by DNA Transfection
Authors: Doniger J. , Di Paolo J. A. , Popescu N. C.
Published: October 2006

Nonmalignant diploid human fibroblast cells (GM3498B) derived from a skin biopsy of a patient with Bloom's syndrome have been transformed by transfection with DNA from a tumorigenic mouse cell line (Ha-8) carrying a single copy of the Harvey murine sarcoma virus (Ha-MuSV) genome. The transformed cell lines have an extended life-span, form colonies in agarose, and proliferate in nude mice—characteristics of neoplastic transformation. Like the parental cells, they also exhibit a high spontaneous level of sister chromatid exchanges. Finally, the transformed cells contain most, if not all, of the Ha-MuSV genome as well as the human
ras
H
sequence. These experiments show that these diploid nonmalignant human cells can be used as recipients in transfection experiments for studying the genetic control of neoplastic transformation.
Activation of Pontine Cholinergic Sites Implicated in Unconsciousness Following Cerebral Concussion in the Cat
Authors: Hayes R. L. , Pechura C. M. , Katayama Y. , Povlishock J. T. , Giebel M. L. , Becker D. P.
Published: October 2006

Low levels of cerebral concussion in the cat produce reversible behavioral suppression presumably associated with unconsciousness. This injury is also associated with increased rates of glucose utilization in regions within the dorsomedial pontine tegmentum. Microinjection of carbachol into these regions produced behavioral suppression resembling that following concussion. These data, together with previously published observations on cholinergic responses to brain injury, suggest that concussive unconsciousness may be attributable in part to activation of cholinergic pontine sites.
Spatially Nonuniform Changes in Intracellular Calcium Ion Concentrations
Authors: Harary H. H. , Brown J. E.
Published: October 2006

The spatial variation of changes in intracellular calcium ions were studied with a one-dimensional scanning microphotometer. Changes in intracellular calcium were measured with a metallochromic dye, arsenazo III. Both the magnitude and the kinetics of changes in calcium were dramatically different in different regions of a cell. In Limulus ventral photoreceptors the maximum change was probably restricted to the rhabdomeric lobe.
Endocytosis: Relation to Capping and Cell Locomotion
Authors: Bretscher Mark S.
Published: October 2006

Most mammalian cells, such as fibroblasts, continuously internalize part of their surface membrane by endocytosis, and then later return it to the cell surface. This cyclical process is initiated by coated pits in the plasma membrane. These pits collect specific receptors plus lipid for internalization, but exclude other proteins. On a motile cell, the sites of endocytosis (randomly located on the cell) and those of membrane return (located at the front of the cell) are not coincident. This causes a bulk flow of lipid plus receptors in the plasma membrane, away from the front of the cell. Large objects on the cell surface are swept to the rear of the cell by this flow, a process called capping. Cells may use this polarized endocytic cycle to move.
Human Immunoglobulin Heavy Chain Genes Map to a Region of Translocations in Malignant B Lymphocytes
Authors: Kirsch Ilan R. , Morton Cynthia C. , Nakahara Kenneth , Leder Philip
Published: October 2006

A human immunoglobulin heavy chain (γ 4) gene is mapped by chromosome hybridization in situ. This gene is located at band 14q32, a site commonly involved in a chromosomal translocation characteristic of malignant B cells.
Fourier Transform Infrared Difference Spectra of Intermediates in Rhodopsin Bleaching
Authors: Rothschild Kenneth J. , Cantore William A. , Marrero Hector
Published: October 2006

The membrane protein rhodopsin is the primary light receptor in vision. Fourier transform infrared difference spectroscopy is sensitive to conformational changes in both the protein and the retinylidene chromophore of rhodopsin. By blocking rhodopsin bleaching at specific intermediates, it is possible to elucidate some of the primary molecular events of vision.
Modifying Oculomotor Activity in Awake Subjects Increases the Amplitude of Eye Movements During REM Sleep
Authors: Herman John H. , Roffwarg Howard P.
Published: October 2006

The eye movements of human subjects were experimentally modified while they were awake to determine the effect of waking experience on electroculographic activity during rapid eye movement (REM) sleep. After normal eye movements were monitored under controlled conditions, subjects spent 5 days wearing goggles that contained minification lenses and that curtailed vision to a 5° field. The amplitude and frequency of eye movements decreased when subjects were awake and increased during REM sleep; sleep stage durations and distributions were unaffected. Values returned to normal in the first 24 hours of recovery.
Mutual Coupling Between the Ocular Circadian Pacemakers of
Bulla gouldiana
Authors: Roberts Michael H. , Block Gene D.
Published: October 2006

The ocular circadian pacemakers of
Bulla gouldiana
were found to be mutually coupled, and their interaction could be observed in an isolated nervous system maintained in vitro. Experimentally induced phase separations between the two ocular pacemakers were reduced when the eyes were allowed to interact for 48 hours. The reduction in phase separation did not occur however when the cerebral commissure was severed, indicating that this neural tract is a critical pathway coupling these two circadian clocks.
Recognition of H-2 Types in Relation to the Blocking of Pregnancy in Mice
Authors: Yamazaki Kunio , Beauchamp Gary K. , Wysocki Charles J. , Bard Judith , Thomas Lewis , Boyse Edward A.
Published: October 2006

Inbred BALB/c females were mated and subsequently exposed in a divided cage to "stimulus" males or females whose H-2 type was similar or dissimilar to the stud male's. The incidence of pregnancy blocking was considerably higher when stud and stimulus males differed in H-2 type than when they did not. Similar results were obtained with urine samples of H-2 identical and nonidentical males. Females exposed after mating to other females whose H-2 type differed from the stud male, under the same experimental conditions, also showed an appreciable incidence of pregnancy block. It is therefore concluded that chemosensory recognition of H-2 types affects the reproductive hormonal status of the pregnant female.
N
-Nitroso Compounds: Evidence for Their Presence in Airborne Particles
Authors: Kneip T. J. , Daisey J. M. , Solomon J. J. , Hershman R. J.
Published: October 2006

Chemical, infrared, and thermal energy analyses have provided evidence for the presence of the
N
-nitroso functional group in extracts of airborne particles. The total molar
N
-nitroso concentrations in New York City air are equivalent to the total concentrations of polycyclic aromatic hydrocarbons. Since 90 percent of the
N
-nitroso compounds that have been tested are carcinogens, the newly discovered but untested materials may represent a significant environmental hazard.
Maternal Ethanol Exposure Induces Transient Impairment of Umbilical Circulation and Fetal Hypoxia in Monkeys
Authors: Mukherjee Anil B. , Hodgen Gary D.
Published: October 2006

When ethanol was administered intravenously to pregnant monkeys, a transient but marked collapse of umbilical vasculature was observed uniformly within about 15 minutes. The ethanol-induced impairment of umbilical circulation produced severe hypoxia and acidosis in the fetus; recovery occurred during the succeeding hour. This striking interruption of feto-placental circulation may explain one of the mechanisms of mental retardation, a frequent manifestation in children afflicted with fetal alcohol syndrome.
Astigmatism in Infants
Authors: Mohindra Indra , Held Richard , Gwiazda Jane , Brill Sarah
Published: October 2006

Compared with children of school age, infants show ten times the incidence and considerably greater amounts of clinically significant astigmatism. The amount begins to decrease in the second semester of life, and the incidence declines during the third year. These unanticipated results bear on both the etiology and the neural sequelae of astigmatism.
Cytostructural Localization of a Tumor-Associated Antigen
Authors: Howard Donald R. , Batsakis John G.
Published: October 2006

Tumor cell membrane glycoproteins may be involved in the induction of tumor immunity or in the escape of tumors from immunologic defense mechanisms. Forty-four benign and malignant breast lesions were examined for the presence of a carbohydrate precursor antigen (T antigen) of the human blood group system MN. T antigen was demonstrated by means of an immunohistochemical technique to detect tissue binding of peanut agglutinin, a plant lectin, with affinity for T antigen. Malignant breast lesions showed a pattern of T antigen expression different from that of benign breast tissues. A possible role for T antigen in the modulation of the immune response to breast carcinoma is suggested.
Age at Menarche: A Misunderstanding
Authors: Bullough Vern L.
Published: October 2006

Through a misinterpretation of historical data, the age of menarche in the 19th century is erroneously taken to have been 17 years. This error has resulted in unwarranted beliefs about change in female sexual maturation in the United States.
Mesenchymal Cells from the Human Embryonic Palate Are Highly Responsive to Epidermal Growth Factor
Authors: Yoneda Toshiyuki , Pratt Robert M.
Published: October 2006

An established line of mesenchymal cells from the human embryonic palate is highly sensitive to the stimulatory effect of epidermal growth factor on growth, labeled thymidine incorporation, and ornithine decarboxylase activity. The results suggest that epidermal growth factor may play a key role in development of various human embryonic and fetal tissues.
The Behavioral and Social Sciences
Authors: Simon Herbert A.
Published: October 2006

In the social sciences, as in other sciences, progress is often paced by advances in observational techniques and instruments. This article reviews some of the recent technical progress in the social sciences and then discusses three substantive frontier areas that are particularly exciting at present: evolutionary theory, especially in relation to sociobiology, the theory of human rational choice, and the newly christened discipline of cognitive science. All three claim to provide explanations for broad areas of human behavior.
Correcting the Phenotype of the Epidermis from Chick Embryos Homozygous for the Gene Scaleless (
sc
/
sc
)
Authors: McAleese Susan R. , Sawyer Roger H.
Published: October 2006

Scutate scales are completely missing in the scaleless (
sc
/
sc
) mutant chicken. Organ cultures consisting of epidermis from
sc
/
sc
embryos combined with normal (+/+) scale dermis of the same developmental age produce the scaleless phenotype, but the same scaleless epidermis in combination with normal dermis from more differentiated embryonic scales forms perfectly normal scales.
Neonatal Thymectomy Prevents Spontaneous Diabetes Mellitus in the BB/W Rat
Authors: Like Arthur A. , Kislauskis Edward , Williams R. Michael , Rossini Aldo A.
Published: October 2006

Complete neonatal thymectomy reduced the frequency of spontaneous diabetes mellitus in BioBreeding/Worcester rats from 27 to 3 percent. Incomplete thymectomy also significantly reduced the frequency of diabetes (to 9 percent). These findings strengthen the hypothesis that thymus-dependent, cell-mediated autoimmune destruction of pancreatic β cells is responsible for the pathogenesis of diabetes in this experimental animal.
Taste Responses in Sheep Medulla: Changes During Development
Authors: Mistretta Charlotte M. , Bradley Robert M.
Published: October 2006

Response characteristics of taste neurons in the sheep solitary tract and nuclei alter during development. Solitary tract cells in younger fetuses respond to stimulation of the tongue with fewer salts and acids than do cells in older fetuses, lambs, and adults. Further, responses to specific salts and acids develop in a particular sequence, not randomly. These changes may relate to maturation of taste receptor sites.
Phagocytosis: Flow Cytometric Quantitation with Fluorescent Microspheres
Authors: Steinkamp John A. , Wilson Julie S. , Saunders George C. , Stewart Carleton C.
Published: October 2006

The phagocytosis of uniform fluorescent latex particles by pulmonary macrophages in the rat was analyzed by flow cytometric methods. The percentage of phagocytic macrophages and the number of particles per cell were determined from cell-size and fluorescence histograms. A comparison of in vivo and in vitro phagocytosis data showed that the percentage of phagocytic lavaged macrophages reflected the availability of instilled particles. With sodium azide used to model phagocytosis inhibition, it was shown that the percentage of phagocytic cells and the number of particles per cell can be determined simultaneously.
Human Liver MAO-A and MAO-B Separated by Immunoaffinity Chromatography with MAO-B-Specific Monoclonal Antibody
Authors: Denney Richard M. , Fritz Richard R. , Patel Nutan T. , Abell Creed W.
Published: October 2006

A monoclonal antibody was used to prepare immunoaffinity columns that efficiently bind monoamine oxidase B activity but not monoamine oxidase A activity from detergent extracts of human liver mitochondria. The only discrete polypeptide component that eluted from affinity columns with potassium thiocyanate migrated in sodium dodecyl sulfate-polyacrylamide gels with an apparent molecular weight of 59,000, as expected for human monoamine oxidase B. These results support the hypothesis that there is an intrinsic structural difference between monoamine oxidase A and B and demonstrate that immunoaffinity chromatography can physically resolve the two enzyme species in liver extracts.
Modulation of Spasticity: Prolonged Suppression of a Spinal Reflex by Electrical Stimulation
Authors: Walker Judith B.
Published: October 2006

Electrical subcutaneous nerve stimulation of radial, median, and saphenous nerves has been shown to produce prolonged analgesia. In a double blind study, such stimulation also suppressed clonus for 3 hours after stimulation ceased in subjects with spasticity. Since the effect is contralateral, each subject was his own control. Because stimulation of the nerve in the wrist suppressed ankle clonus, the mechanism mediating the effect must be centrifugal inhibition. These results suggest that subcutaneous nerve stimulation may also be a tool in the management of spasticity.
Secretion of Newly Taken-Up Ascorbic Acid by Adrenomedullary Chromaffin Cells
Authors: Daniels Alejandro J. , Dean Grace , Viveros O. Humberto , Diliberto Emanuel J.
Published: October 2006

Primary cultures of bovine adrenomedullary cells accumulate carbon-14-labeled ascorbic acid through a saturable and energy-dependent process. The newly taken-up ascorbate is released concomitantly with catecholamines upon stimulation of chromaffin cell secretion. The release of ascorbate is Ca
2+
-dependent and mediated through activation of nicotinic receptors. These results indicate that exogenous ascorbate taken up into chromaffin cells is incorporated in situ into a secretable compartment, probably the catecholamine-containing chromaffin vesicles.
Enhancement of Sexual Behavior in Female Rats by Neonatal Transplantation of Brain Tissue from Males
Authors: Arendash Gary W. , Gorski Roger A.
Published: October 2006

Transplantation of preoptic tissue from male rat neonates into the preoptic area of female littermates increased masculine and feminine sexual behavior in the recipients during adulthood. This suggests that functional connections develop between the transplanted neural tissue and the host brain. A new intraparenchymal brain transplantation technique was used to achieve these results.
Biospecific Labeling with Undecagold: Visualization of the Biotin-Binding Site on Avidin
Authors: Safer Daniel , Hainfeld James , Wall Joseph S. , Reardon John E.
Published: October 2006

The biotin-binding site on avidin has been labeled with biotin conjugated to undecagold, an organometallic cluster compound containing 11 gold atoms in a core 10 angstroms in diameter. Examination of unstained specimens by scanning transmission electron microscopy reveals the labeled sites directly, without computational averaging or filtering of the images. This approach should be widely applicable for determining the locations of subunits and functional sites in biological macromolecules at a resolution in the range of 15 angstroms.
Neural Control of Swimming in a Vertebrate
Authors: Roberts Alan , Kahn J. A. , Soffe S. R. , Clarke J. D. W.
Published: October 2006

An excitatory drive to the spinal cord neurons supplying rhythmic locomotor output in swimming was demonstrated in paralyzed late
Xenopus
embryos. The motor system for a single muscle can independently generate rhythmic motor discharge with the normal swimming cycle period.
Loss of Division Potential in Vitro: Aging or Differentiation?
Authors: Bell E. , Marek L. F. , Levinstone D. S. , Merrill C. , Sher S. , Young I. T. , Eden M.
Published: October 2006

We have examined the hypothesis that diploid cells grown in vitro age, and propose that only proliferative potential and not life-span is telescoped. We suggest that explanted or transplanted diploid cells are driven to divide by the process of subculturing in vitro or in vivo and, in response to this pressure, also complete their differentiation and become refractory to further mitotic stimulation. We conclude that differentiation rather than "mortality" distinguishes diploid from transformed cells and that the former may not age in vitro, but are lost because culture methods are selective for cycling cells.
Collagen αB Chain: Increased Proportion in Human Atherosclerosis
Authors: Ooshima Akira
Published: October 2006

In a study of human atherosclerotic plaques, the relative abundance of α chains in pepsin-solubilized collagens from 28 human aortas was estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The ratio of αB, a component of the α chain in type V collagen, to α1(I) was markedly increased in the atherosclerotic plaques compared to the nonsclerotic intact media and adventitia. It is suggested that proliferating smooth muscle cells in the sclerotic lesion were transformed to synthesize a larger amount of collagen αB chain during the process of human atherogenesis.
Development of Stereopsis and Cortical Binocularity in Human Infants: Electrophysiological Evidence
Authors: Petrig Benno , Julesz Bela , Kropfl Walter , Baumgartner Guenter , Anliker Max
Published: October 2006

Dynamic random-dot stereograms and correlograms were used to elicit visually evoked brain potentials from human infants, and these potentials were compared with potentials evoked by classical checkerboard pattern reversal. The results indicate that infants begin to produce stereoscopically evoked potentials at the age of 10 to 19 weeks, several weeks after showing classical checkerboard-evoked potentials, and suggest that the onset of cortical binocularity precedes stereopsis.
Familial Retinoblastoma and Chromosome 13 Deletion Transmitted via an Insertional Translocation
Authors: Strong Louise C. , Riccardi Vincent M. , Ferrell Robert E. , Sparkes Robert S.
Published: October 2006

Surviving persons from a kindred in which retinoblastoma occurred over four generations, transmitted by eight unaffected individuals, underwent chromosomal analysis. The results revealed that the development of retinoblastoma was associated with a constitutional chromosome deletion del(13)(q13.1q14.5) and that the unaffected transmitting state was associated with a balanced insertional translocation. These findings indicate that predisposition to retinoblastoma may be attributed to the loss of specific genetic material and that a chromosomal mechanism may explain apparent lack of gene penetrance in certain families. The development of unilateral, and not bilateral, retinoblastoma suggests either that the chromosome deletion is different from the mutation of heritable retinoblastoma in general, or that the chromosome deletion lessens the probability of subsequent somatic carcinogenic events.
Dietary Restriction Retards the Age-Associated Loss of Rat Striatal Dopaminergic Receptors
Authors: Levin Philip , Janda Jean K. , Joseph James A. , Ingram Donald K. , Roth George S.
Published: October 2006

In male Wistar rats subjected to dietary restriction by alternate days of feeding and fasting the normal age-associated loss of striatal dopamine receptors in the brain was substantially retarded. The mean survival time of the rats on the restricted diet was increased by approximately 40 percent compared to control rats given free access to food. Dopamine receptor concentrations in striata of 24-month-old rats that had been on a restricted diet since weaning were 50 percent higher than those of control animals of the same age, and essentially comparable to 3- to 6-month-old control rats.
Development of Visual Centers in the Primate Brain Depends on Binocular Competition Before Birth
Authors: Rakic Pasko
Published: October 2006

Removal of one eye before birth permanently changes the cellular organization and synaptic connectivity of visual centers in the primate brain. The most notable alterations are (i) the lateral geniculate nucleus develops only two cellular layers and one interlaminar fiber band instead of the normal six layers and five bands, (ii) aberrant synaptic connections are formed between the intact eye and the geniculate neurons that have lost their normal input, and (iii) ocular dominance columns fail to develop in the visual cortex.
Taurine: Possible Role in Osmotic Regulation of Mammalian Heart
Authors: Thurston Jean Holowach , Hauhart Richard E. , Naccarato Elise F.
Published: October 2006

It is well established that taurine plays an important role in the maintenance of intracellular osmolal concentration in marine invertebrates, teleosts, and amphibians. In fresh water, concentrations of taurine in body tissues decrease; in salt water, they increase. In this study with mice we found that during adaptation of these mammals to chronic hypernatremia, the taurine content of the heart increased; concentrations of other amino acids were unchanged or were decreased. Welty and his associates have shown that acute hyponatremia lowered the taurine concentration of rat heart. In concert, these data suggest that taurine also may serve as an osmotic agent in mammalian heart.
Research, Innovation, and University-Industry Linkages
Authors: Prager Denis J. , Omenn Gilbert S.
Published: October 2006

Carter Administration actions to enhance basic research and stimulate industrial innovation have focused attention on the importance of formal university-industry cooperative relationships in science and engineering. We have examined the status of, and potential for, university-industry research consortia and research partnerships and the current and prospective roles of the federal government in stimulating such relationships.
Tooth Induction in Chick Epithelium: Expression of Quiescent Genes for Enamel Synthesis
Authors: Kollar E. J. , Fisher C.
Published: October 2006

Intraocular grafts of chick epithelium combined with mouse molar mesenchyme produced a variety of dental structures including perfectly formed crowns with differentiated ameloblasts depositing enamel matrix. The results suggest that the loss of teeth in Aves did not result from a loss of genetic coding for enamel synthesis in the oral epithelium but from an alteration in the tissue interactions requisite for odontogenesis.
Dendrodendritic Inhibition: Demonstration with Intracellular Recording
Authors: Jahr C. E. , Nicoll R. A.
Published: October 2006

The isolated turtle olfactory bulb was used to characterize synaptic interactions between mitral and granule cell dendrites. First, blockade of antidromic invasion of mitral cell dendrites caused a large decrease in the size of the inhibitory postsynaptic potential (IPSP) recorded in mitral cells, indicating that the IPSP results in large part from activity in the dendrites of mitral cells. Second, direct depolarization of mitral cells was followed by an IPSP. In the presence of tetrodotoxin, depolarization of mitral cells evoked calcium spikes (as would be expected for presynaptic membranes) followed by IPSP's. These findings demonstrate that regenerative sodium spikes and axonal pathways are not required for this inhibitory pathway and that the inhibition is indeed a result of local dendritic interaction. Such a pathway provides an obligatory synaptic inhibition of mitral cells following their activation and emphasizes the tight coupling that exists with reciprocal dendrodendritic synapses.
Modeling Coordination Sites in Metallobiomolecules
Authors: Ibers James A. , Holm Richard H.
Published: October 2006

Synthetic metal complexes can closely approach the properties of metal ions in proteins and yield useful information concerning biological structure and function.
Nonpineal Melatonin in the Alligator (
Alligator mississippiensis
)
Authors: Roth Jan J. , Gern William A. , Roth E. Carol , Ralph Charles L. , Jacobson Elliott
Published: October 2006

All living and most fossil representatives of the reptilian subclass Archosauria lack pineal bodies. Arrhythmic, low-level, nonpineal melatonin is present, however, in the blood of
Alligator mississippiensis
. Although pineal bodies have been implicated in circadian phenomena, these results suggest that arrhythmic melatonin in alligators may not be involved in circadian events and indicate that the pineal is not the only source of the hormone melatonin. The evolutionary loss of the pineal in Archosauria occurred during the Mesozoic, an era noted for its seasonal stability. Arrhythmic melatonin titers in alligators and pineal loss in alligators and other archosaurs may be related to Mesozoic seasonal stability.
Bandwidth Requirements for Video Transmission of American Sign Language and Finger Spelling
Authors: Sperling George
Published: October 2006

Although current video communication schemes use a bandwidth on the order of 1 megahertz, the bandwidth required for video communication of American Sign Language by a simple raster scan is only approximately 20 kilohertz.
Inhibition of the EGF-Activated MAP Kinase Signaling Pathway by Adenosine 3′,5′-Monophosphate
Authors: Wu Jie , Dent Paul , Jelinek Tomas , Wolfman Alan , Weber Michael J. , Sturgill Thomas W.
Published: October 2006

Mitogen-activated protein (MAP) kinases p42
mapk
and p44
mapk
are activated in cells stimulated with epidermal growth factor (EGF) and other agents. A principal pathway for MAP kinase (MAPK) activation by EGF consists of sequential activations of the guanine nucleotide exchange factor Sos, the guanosine triphosphate binding protein Ras, and the protein kinases Raf-1, MAPK kinase (MKK), and MAPK. Because adenosine 3′,5′-monophosphate (cAMP) does not activate MAPK and has some opposing physiologic effects, the effect of increasing intracellular concentrations of cAMP with forskolin and 3-isobutyl-1-methylxanthine on the EGF-stimulated MAPK pathway was studied. Increased concentrations of cAMP blocked activation of Raf-1, MKK, and MAPK in Rat1hER fibroblasts, accompanied by a threefold increase in Raf-1 phosphorylation on serine 43 in the regulatory domain. Phosphorylation of Raf-1 in vitro and in vivo reduces the apparent affinity with which it binds to Ras and may contribute to the blockade by cAMP.
Long-Term Survival of Skin Allografts in Mice Treated with Fractionated Total Lymphoid Irradiation
Authors: Slavin S. , Strober S. , Fuks Z. , Kaplan H. S.
Published: October 2006

Treatment of recipient Balb/c mice with fractionated, high-dose total lymphoid irradiation, a procedure commonly used in the therapy of human malignant lymphomas, resulted in fivefold prolongation of the survival of C57BL/Ka skin allografts despite major histocompatibility differences between the strains (H-2
d
and H-2
b
, respectively). Infusion of 10
7
(C57BL/Ka × Balb/c)F
1
bone marrow cells after total lymphoid irradiation further prolonged C57BL/Ka skin graft survival to more than 120 days. Total lymphoid irradiation may eventually prove useful in clinical organ transplantation.
Deficient Ganglioside Biosynthesis: A Novel Human Sphingolipidosis
Authors: Fishman Peter H. , Max Stephen R. , Tallman John F. , Brady Roscoe O. , Maclaren Noel K. , Cornblath Marvin
Published: October 2006

An unusual lipid storage disease is characterized by the accumulation of hematoside (G
ms3
) in the patient's liver and brain. In contrast to the other sphingolipidoses, the accumulation of G
ms3
is not the result of a defective catabolic reaction, but is the first disorder caused by a deficiency in ganglioside biosynthesis to be described in man.
cDNA Cloning and Interferon γ Down-Regulation of Proteasomal Aubunits X and Y
Authors: Akiyama Kin-ya , Yokota Kim-ya , Kagawa Susumu , Shimbara Naoki , Tamura Tomohiro , Akioka Hiroshi , Nothwang Hans G. , Noda Chiseko , Tanaka Keiji , Ichihara Akira
Published: October 2006

Proteasomes are the proteolytic complex responsible for major histocompatibility complex (MHC) class I-restricted antigen presentation. Interferon γ treatment increases expression of MHC-encoded LMP2 and LMP7 subunits of the proteasome and decreases expression of two proteasome subunits, named X and Y, which alters the proteolytic specificity of proteasomes. Molecular cloning of complementary DNAs encoding X and Y showed that their proteins are proteasomal subunits with high amino acid similarity to LMP7 and LMP2, respectively. Thus, interferon γ may induce subunit replacements of X and Y by LMP7 and LMP2, respectively, producing proteasomes perhaps more appropriate for the immunological processing of endogenous antigens.
MHC Class I Expression in Mice Lacking the Proteasome Subunit LMP-7
Authors: Fehling H. J. , Swat W. , Laplace C. , Kühn R. , Rajewsky K. , Müller U. , von Boehmer H.
Published: October 2006

Proteasomes degrade endogenous proteins. Two subunits, LMP-2 and LMP-7, are encoded in a region of the major histocompatibility complex (MHC) that is critical for class I-restricted antigen presentation. Mice with a targeted deletion of the gene encoding LMP-7 have reduced levels of MHC class I cell-surface expression and present the endogenous antigen HY inefficiently; addition of peptides to splenocytes deficient in LMP-7 restores wild-type class I expression levels. This demonstrates the involvement of LMP-7 in the MHC class I presentation pathway and suggests that LMP-7 functions as an integral part of the peptide supply machinery.
Vasopressin: Induced Structural Change in Toad Bladder Luminal Membrane
Authors: Kachadorian William A. , Wade James B. , DiScala Vincent A.
Published: October 2006

Freeze-fracture electron microscopy demonstrates that vasopressin stimulation of isolated toad bladder alters the structure of the luminal membrane of granular cells. This alteration consists of an ordered aggression of intramembranous particles, and appears to be of functional significance, since the frequency of aggregation sites per area of membrane is closely correlated with vasopressin-induced osmotic water flow.
Sequestration From Immune CD4
+
T Cells of Mycobacteria Growing in Human Macrophages
Authors: Pancholi Preeti , Mirza Asra , Bhardwaj Nina , Steinman Ralph M.
Published: October 2006

CD4
+
helper T cells mediate resistance to tuberculosis, presumably by enhancing the antimicrobial activity of macrophages within which the
Mycobacterium tuberculosis
organism grows. A first step in resistance should be the presentation of mycobacterial antigens by macrophages to CD4
+
T cells. However, when the antigenic stimulus is limited to organisms growing in human monocytes, the organisms become sequestered from immune CD4
+
T cells. This block in presentation is selective for growing mycobacteria and not for other stimuli. Sequestration would allow replicating organisms to persist in infected individuals and may contribute to virulence.
Visual Discrimination Impaired by Cutting Temporal Lobe Connections
Authors: Horel James A. , Misantone Louis J.
Published: October 2006

An attempt was made to transect the white matter that connects the anterior temporal lobe with dorsal and medial brain areas. Eight monkeys were trained preoperatively on a visual discrimination and tested postoperatively for retention and relearning of the task. They were also tested for Kluver-Bucy symptoms. The two animals that had complete lesions were unable to relearn the visual discrimination. It is suggested that human medial temporal lesions may produce their effects on learning and retention by damage to temporal white matter rather than by destruction of hippocampus.
Regional Codon Randomization: Defining a TATA-Binding Protein Surface Required for RNA Polymerase III Transcription
Authors: Cormack Brendan P. , Struhl Kevin
Published: October 2006

The TATA-binding protein (TBP) is required for transcription by all three nuclear RNA polymerases. TBP was subjected to regional codon randomization, a codon-based mutagenesis method that generates complex yet compact protein libraries. Analysis of 186 temperature-sensitive TBP mutants yielded 65 specifically defective in transcription by RNA polymerase III (Pol III). These mutants map to a limited TBP surface that may interact with Tds4, a component of the Pol III transcription factor TFIIIB. Strains that contain the Pol III-defective derivatives have increased amounts of messenger RNA, which suggests that competition among TBP-interacting factors for limiting quantities of TBP determines the ratio of Pol II and Pol III transcription in vivo.
HTLV-I Tax Protein Stimulation of DNA Binding of bZIP Proteins by Enhancing Dimerization
Authors: Wagner Susanne , Green Michael R.
Published: October 2006

The Tax protein of human T cell leukemia virus type-1 (HTLV-I) transcriptionally activates the HTLV-I promoter. This activation requires binding sites for activating transcription factor (ATF) proteins, a family of cellular proteins that contain basic region-leucine zipper (bZIP) DNA binding domains. Data are presented showing that Tax increases the in vitro DNA binding activity of multiple ATF proteins. Tax also stimulated DNA binding by other bZIP proteins, but did not affect DNA binding proteins that lack a bZIP domain. The increase in DNA binding occurred because Tax promotes dimerization of the bZIP domain in the absence of DNA, and the elevated concentration of the bZIP homodimer then facilitates the DNA binding reaction. These results help explain how Tax activates viral transcription and transforms cells.
Histone Transition During Spermiogenesis Is Absent in Segregation Distorter Males of
Drosophila melanogaster
Authors: Kettaneh Nizam P. , Hartl Daniel L.
Published: October 2006

Males homozygous for the segregation distorter chromosome are often sterile or nearly sterile as a result of the dysfunction of virtually all their sperm. Spermatid bundles from such males do not exhibit the normal transition from lysine-rich to arginine-rich histones.
Interaction of Shc with the ζ Chain of the T Cell Receptor Upon T Cell Activation
Authors: Ravichandran Kodimangalam S. , Lee Kyungah Kay , Songyang Zhou , Cantley Lewis C. , Burn Paul , Burakoff Steven J.
Published: October 2006

The
shc
oncogene product is tyrosine-phosphorylated by Src family kinases and after its phosphorylation interacts with the adapter protein Grb2 (growth factor receptor-bound protein 2). In turn, Grb2 interacts with the guanine nucleotide exchange factor for Ras, mSOS. Because several Src family kinases participate in T cell activation and Shc functions upstream of Ras, the role of Shc in T cell signaling was examined. Shc was phosphorylated on tyrosine after activation through the T cell receptor (TCR), and subsequently interacted with Grb2 and mSOS. The Src homology region 2 (SH2) domain of Shc directly interacted with the tyrosine-phosphorylated ζ chain of the TCR. Thus, Shc may couple TCR activation to the Ras signaling pathway.
Reexamination of Tetradecenyl Acetates in Oak Leaf Roller Sex Pheromone and in Plants
Authors: Hindenlang D. M. , Wichmann J. K.
Published: October 2006

The chemistry of the oak leaf roller sex pheromone is shown by means of microozonolysis and computerized gas chromatography-mass spectrometry to be dominated by an approximate 70 to 30 ratio of E- and Z-11-tetradecenyl acetates. Tetradecenyl acetates are undetectable in highly purified oak leaf, apple leaf, and corn extracts analyzed by gas chromatography-mass spectrometry. These results reflect negatively on previous reports and on the hypothesis that plant components might govern insect chemical communication systems.
A Detailed Genetic Map for the X Chromosome of the Malaria Vector,
Anopheles gambiae
Authors: Zheng Liangbiao , Collins Frank H. , Kumar Vasantha , Kafatos Fotis C.
Published: October 2006

Anopheles gambiae
, the primary vector of human malaria in Africa, is responsible for approximately a million deaths per year, mostly of children. Despite its significance in disease transmission, this mosquito has not been studied extensively by genetic or molecular techniques. To facilitate studies on this vector, a genetic map has been developed that covers the X chromosome at an average resolution of 2 centimorgans. This map has been integrated with the chromosome banding pattern and used to localize a recessive, sex-linked mutation (
white eye
) to within 1 centimorgan of flanking markers.
Neuroblast Specification and Formation Regulated by
wingless
in the
Drosophila
CNS
Authors: Chu-LaGraff Quynh , Doe Chris Q.
Published: October 2006

The
Drosophila
central nervous system (CNS) develops from a heterogeneous population of neural stem cells (neuroblasts), yet the genes regulating neuroblast determination remain unknown. The segmentation gene
wingless
is regionally expressed in the neuroectoderm from which neuroblasts develop. A conditional
wingless
mutation is used to inactivate CNS function without affecting segmentation. The stripe of wingless-expressing neuroectoderm generates apparently normal neuroblasts after wingless inactivation; however, adjacent anterior and posterior neuroectoderm requires wingless nonautonomously for subsequent neuroblast determination and formation. Loss of wingless results in the absence or duplication of identified neuroblasts, highlighting its role in generating neuroblast diversity in the CNS.
Induction by EGF and Interferon-γ of Tyrosine Phosphorylated DNA Binding Proteins in Mouse Liver Nuclei
Authors: Ruff-Jamison Susan , Chen Katherine , Cohen Stanley
Published: October 2006

Intraperitoneal injection of epidermal growth factor (EGF) into mice resulted in the appearance in liver nuclei of three tyrosine phosphorylated proteins (84, 91, and 92 kilodaltons) within minutes after administration of EGF. Administration of interferon-γ (IFN-γ) resulted in the appearance in liver nuclei of two tyrosine phosphorylated proteins (84 and 91 kilodaltons). The 84- and 91-kilodalton proteins detected after either EGF or IFN-γ administration were identified as the IFN-γ activation factors (GAF). Furthermore, gel shift analysis revealed that these GAF proteins, detected after either EGF or IFN-γ administration, specifically bound to the sis-inducible element of the c-
fos
promoter. Thus, GAF proteins participate in nuclear signaling in both IFN-γ and EGF pathways.
Separable Regulatory Elements Governing
myogenin
Transcription in Mouse Embryogenesis
Authors: Cheng Tse-Chang , Wallace Mia C. , Merlie John P. , Olson Eric N.
Published: October 2006

Expression of the myogenic helix-loop-helix (HLH) protein myogenin in muscle cell precursors within somites and limb buds is among the earliest events associated with myogenic lineage determination in vertebrates. Mutations in the
myogenin
promoter that abolish binding sites for myogenic HLH proteins or myocyte enhancer factor-2 (MEF-2) suppressed transcription of a linked
lacZ
transgene in subsets of myogenic precursors in mouse embryos. These results suggest that myogenic HLH proteins and MEF-2 participate in separable regulatory circuits leading to
myogenin
transcription and provide evidence for positional regulation of myogenic regulators in the embryo.
Human c-
myc
Transcription Factor PuF Identified as nm23-H2 Nucleoside Diphosphate Kinase, a Candidate Suppressor of Tumor Metastasis
Authors: Postel E. H. , Berberich S. J. , Flint S. J. , Ferrone C. A.
Published: October 2006

A human gene encoding the c-
myc
purine-binding transcription factor PuF was identified by screening of a cervical carcinoma cell complementary DNA library with a DNA fragment containing PuF binding sites. The 17-kilodalton bacterially produced PuF was shown to have biological activity and properties similar to that of human PuF. DNA sequence analysis of recombinant PuF revealed perfect identity with the human
nm23-H2
nucleoside diphosphate kinase gene, a potential negative regulator of cancer metastasis. These results provide a link between
nm23
and the c-
myc
oncogene and suggest that the nm23 protein can function in vitro in the transcriptional regulation of c-
myc
expression.
25-Hydroxycholecalciferol to 1,25-Dihydroxycholecalciferol: Conversion Impaired by Systemic Metabolic Acidosis
Authors: Lee Sook Won , Russell Jean , Avioli Louis V.
Published: October 2006

An acute systemic acidosis in vitamin D depleted rats that was induced by ammonium chlroide feeding resulted in defective biological hydroxylation of 25-hydroxycholecalciferol to 1,25-dihydroxycholecalciferol. Impaired enzymatic hydroxylation occurred despite the presence of either hypophosphatemia or hypocalcemia. The data suggest that acidosis interferes with the adaptive enzymatic control of 25-hydroxycholecalciferol metabolism in the vitamin D depleted state.
Treatment and Prevention of Rat Glioblastoma by Immunogenic C6 Cells Expressing Antisense Insulin-Like Growth Factor I RNA
Authors: Trojan Jerzy , Johnson Thomas R. , Rudin Susan D. , Ilan Judith , Tykocinski Mark L. , Ilan Joseph
Published: October 2006

Rat C6 glioma cells express insulin-like growth factor I (IGF-I) and form rapidly growing tumors in syngeneic animals. When transfected with an episome-based vector encoding antisense IGF-I complementary DNA, these cells lost tumorigenicity. Subcutaneous injection of IGF-I antisense-transfected C6 cells into rats prevented formation of both subcutaneous tumors and brain tumors induced by nontransfected C6 cells. The antisense-transfected cells also caused regression of established brain glioblastomas when injected at a point distal to the tumor. These antitumor effects result from a glioma-specific immune response involving CD8
+
lymphocytes. Antisense blocking of IGF-I expression may reverse a phenotype that allows C6 glioma cells to evade the immune system.
Shutdown of Class Switch Recombination by Deletion of a Switch Region Control Element
Authors: Jung Steffen , Rajewsky Klaus , Radbruch Aandreas
Published: October 2006

Upon activation, B lymphocytes can change the class of the antibody they express by immunoglobulin class switch recombination. Cytokines can direct this recombination to distinct classes by the specific activation of repetitive recombinogenic DNA sequences, the switch regions. Recombination to a particular switch region (s
γ
1) was abolished in mice that were altered to lack sequences that are 5′ to the s
γ
1 region. This result directly implicates the functional importance of 5′ switch region flanking sequences in the control of class switch recombination. Mutant mice exhibit a selective agammaglobulinemia and may be useful in the assessment of the biological importance of immunoglobulin G1.
Association Between Brain Temperature and Dentate Field Potentials in Exploring and Swimming Rats
Authors: Moser Edvard , Mathiesen lacob , Andersen Per
Published: October 2006

Attempts to correlate behavioral learning with cellular changes, such as increased synaptic efficacy, have often relied on increased extracellular potentials as an index of enhanced synaptic strength. A recent example is the enlarged excitatory field potentials in the dentate gyrus of rats that are learning spatial relations by exploration. The altered hippocampal field potentials do not reflect learning-specific cellular changes but result from a concomitant rise in brain temperature that is caused by the associated muscular effort. Enhanced dentate field excitatory potentials followed both passive and active heating and were linearly related to the brain temperature. These temperature-related effects may mask any learning-induced changes in field potential.
Polar Location of the Chemoreceptor Complex in the
Escherichia coli
Cell
Authors: Maddock Janine R. , Shapiro Lucille
Published: October 2006

The eukaryotic cell exhibits compartmentalization of functions to various membrane-bound organelles and to specific domains within each membrane. The spatial distribution of the membrane chemoreceptors and associated cytoplasmic chemotaxis proteins in
Escherichia coli
were examined as a prototypic functional aggregate in bacterial cells. Bacterial chemotaxis involves a phospho-relay system brought about by ligand association with a membrane receptor, culminating in a switch in the direction of flagellar rotation. The transduction of the chemotaxis signal is initiated by a chemoreceptor-CheW-CheA ternary complex at the inner membrane. These ternary complexes aggregate predominantly at the cell poles. Polar localization of the cytoplasmic CheA and CheW proteins is dependent on membrane-bound chemoreceptor. Chemoreceptors are not confined to the cell poles in strains lacking both CheA and CheW. The chemoreceptor-CheW binary complex is polarly localized in the absence of CheA, whereas the chemoreceptor-CheA binary complex is not confined to the cell poles in strains lacking CheW. The subcellular localization of the chemotaxis proteins may reflect a general mechanism by which the bacterial cell sequesters different regions of the cell for specialized functions.
Linkage on Chromosome 3 of Autoimmune Diabetes and Defective Fc Receptor for IgG in NOD mice
Authors: Prins Jan-Bas , Todd John A. , Rodrigues Nanda R. , Ghosh Soumitra , Hogarth P. Mark , Wicker Linda S. , Gaffney Erin , Podolin Patricia L. , Fischer Paul A. , Sirotina Anna , Peterson Laurence B.
Published: October 2006

A congenic, non-obese diabetic (NOD) mouse strain that contains a segment of chromosome 3 from the diabetes-resistant mouse strain B6.PL-

Thy-1
a

was less susceptible to diabetes than NOD mice. A fully penetrant immunological defect also mapped to this segment, which encodes the high-affinity Fc receptor for immunoglobulin G (IgG), FcγRI. The NOD
Fcgr1
allele, which results in a deletion of the cytoplasmic tail, caused a 73 percent reduction in the turnover of cell surface receptor-antibody complexes. The development of congenic strains and the characterization of Mendelian traits that are specific to the disease phenotype demonstrate the feasibility of dissecting the pathophysiology of complex, non-Mendelian diseases.
Identifying Strategies for Immune Intervention
Authors: Lanzavecchia Antonio
Published: October 2006

In recent years the molecular basis of antigen recognition by T cells has been unraveled and the various pathways that control T cell activation and functional specialization have been defined. Consequently, it is now possible to delineate various strategies for intervention with the immune system to design protective vaccines, to induce an effective response to tumor antigens, and to control graft rejection and autoimmune diseases.