bluuebunny/crossref_metadata_2025 huggingface dataset:
A Mab to a Unique Cerebellar Neuron Generated by Immunosuppression and Rapid Immunization
Authors: Hockfield Susan
Published: October 2006

The cerebellar cortex is perhaps the best characterized structure in the mammalian central nervous system. Although the major cerebellar cell classes are well known, a new class of cerebellar cortical neuron has now been identified with a monoclonal antibody (Mab) generated by a procedure for rapid immunization and selective immunosuppression of antibody responses. This procedure generates a high frequency of immunoglobulin G-class antibodies of desired specificity, and has allowed the generation of two antibodies that recognize subsets of cerebellar cortical neurons. One of these antibodies defines a previously unrecognized class of cerebellar neuron. The distribution and antigenic characteristics of this neuron suggest that it has a distinct role in cerebellar circuitry.
Cloned Fragment of the Hepatitis Delta Virus RNA Genome: Sequence and Diagnostic Application
Authors: Denniston K. J. , Hoyer B. H. , Smedile A. , Wells F. V. , Nelson J. , Gerin J. L.
Published: October 2006

Hepatitis delta virus (HDV) is a replication-defective etiological agent of hepatitis that requires hepatitis B virus (HBV) as a helper. A complementary DNA (cDNA) fragment of the RNA genome of HDV was cloned into the plasmid vector pBR322, and the primary nucleotide sequence and predicted protein products of the cDNA fragment were determined. This cloned cDNA fragment has been used as a sensitive radioactive probe for the detection of HDV RNA in the serum of patients with either acute or chronic HDV infections.
Pertussis Toxin Gene: Nucleotide Sequence and Genetic Organization
Authors: Locht Camille , Keith Jerry M.
Published: October 2006

The current pertussis vaccines, although efficacious, in some instances produce undesirable side effects. Molecular engineering of pertussis toxin, the major protective antigen, could provide a safer, new generation of vaccines against whooping cough. As a first critical step in the development of such a vaccine, the complete nucleotide sequence of the pertussis toxin gene was determined and the amino acid sequences of the individual subunits were deduced. All five subunits are coded by closely linked cistrons. A promoter-like structure was found in the 5′-flanking region, suggesting that the toxin is expressed through a polycistronic messenger RNA. The order of the cistrons is S1, S2, S4, S5, and S3. All subunits contain signal peptides of variable length. The calculated molecular weights of the mature subunits are 26,024 for S1, 21,924 for S2, 21,873 for S3, 12,058 for S4, and 11,013 for S5. Subunits S2 and S3 share 70% amino acid homology and 75% nucleotide homology. Subunit S1 contains two regions of eight amino acids homologous to analogous regions in the A subunit of both cholera and
Escherichia coli
heat labile toxins.
An Extrinsic Membrane Polypeptide Associated with High-Molecular-Weight Protein Aggregates in Human Cataract
Authors: Spector Abraham , Garner Margaret H. , Garner William H. , Roy Debdutta , Farnsworth Patricia , Shyne Susan
Published: October 2006

A 43,000-dalton polypeptide has been isolated from the high-molecular-weight disulfide-rich fraction of the water-insoluble protein of human cataractous lenses. On the basis of immunochemical reactivity and fluorescent antibody binding, this polypeptide is localized in the membrane region of the lens cell. This observation suggests an interaction between the soluble lens proteins and membrane-associated polypeptides in the formation of large protein aggregates which may cause cataract.
Comparative Biochemistry and Drug Design for Infectious Disease
Authors: Cohen Seymour S.
Published: October 2006

In the past two decades, biochemistry and molecular biology have demonstrated the existence of potentially exploitable biochemical differences between etiologic agents of disease and their hosts. Known differences between organism and host with respect to metabolism and polymer structure point to the detailed characterization of key proteins as the focus for the development of potential inhibitors. In the last decade, the methodology of the isolation, characterization, and inactivation of proteins and enzymes has been advanced. The present scientific and technological base suggests that new efforts toward the development of selective chemotherapeutic agents for infections caused by bacteria, viruses, protozoa, and higher eukaryotes should exploit the known differences in proteins or other specific biopolymers serving crucial structural or metabolic roles in the economy of the parasite.
Widespread Distribution of Brain Dopamine Receptors Evidenced with [
125
I]Iodosulpride, a Highly Selective Ligand
Authors: Martres Marie-Pascale , Bouthenet Marie-Louise , Sales Nicole , Sokoloff Pierre , Schwartz Jean-Charles
Published: October 2006

The new benzamide derivative [
125
I]iodosulpride is a highly sensitive and selective ligand for D-2 dopamine receptors and displays a very low nonspecific binding to membrane or autoradiographic sections. On autoradiographic images, D-2 receptors are present not only in well-established dopaminergic areas but also, in a discrete manner, in a number of catecholaminergic regions in which the dopaminergic innervation is still unknown, imprecise, or controversial, as in the sensorimotor cerebral cortex or cerebellum. This widespread distribution suggests larger physiological and pathophysiological roles for cerebral dopamine receptors than was previously thought.
Heparin: An Old Drug with a New Paradigm
Authors: Jacques L. B.
Published: October 2006

Recent studies have shown that heparin is a biochemical representative of a distinct class of compounds known as linear anionic polyelectrolytes. Members of this class are mixtures of individual highly negatively charged chains that show a wide spectrum of specific reactions with biologically active proteins. Upon administration, heparin chains enter a cellular pool and effectively prevent thrombosis by increasing the electronegative potential of the vessel wall. Anticoagulant activity is an unusual feature of a few heparin chains and appears to play a minor role in many clinical uses and in physiological and pathological responses.
Mathematics Achievement of Chinese, Japanese, and American Children
Authors: Stevenson Harold W. , Lee Shin-Ying , Stigler James W.
Published: October 2006

American kindergarten children lag behind Japanese children in their understanding of mathematics; by fifth grade they are surpassed by both Japanese and Chinese children. Efforts to isolate bases for these differences involved testing children on other achievement and cognitive tasks, interviewing mothers and teachers, and observing children in their classrooms. Cognitive abilities of children in the three countries are similar, but large differences exist in the children's life in school, the attitudes and beliefs of their mothers, and the involvement of both parents and children in schoolwork.
Digestive Adaptations for Fueling the Cost of Endothermy
Authors: Karasov William H. , Diamond Jared M.
Published: October 2006

Little is known about the digestive adaptations that enable mammals to sustain metabolic rates an order of magnitude higher than those of reptiles. Comparison of several features of digestion in mammals and lizards of similar size eating the same diet revealed that mammals processed food ten times faster and with the same or greater extraction efficiency. Transport kinetics and rates of nutrient absorption normalized to the quantity of intestinal tissue were similar in these two classes of vertebrates. The main basis for faster absorption in mammals is their much greater intestinal surface area.
Habitat Selection in a Clonal Plant
Authors: Salzman Amy G.
Published: October 2006

Rhizomatous growth may permit the nonrandom placement of ramets into different environments, but whether clonal plants are able to use this means to exercise adaptive habitat choice is not known. Western ragweed (Ambrosia psilostachya) plants are shown to preferentially colonize nonsaline soil over saline soil patches, and clones with the strongest preference for nonsaline soil are those least able to grow when restricted to saline conditions. In clonal plant species, nonrandom associations of genotypes with specific environments may thus reflect habitat selection by plants as well as selective mortality imposed by different habitat patches.
Ethanol Withdrawal in Mice Precipitated and Exacerbated by Hyperbaric Exposure
Authors: Alkana Ronald L. , Finn Deborah A. , Galleisky Guntwin G. , Syapin Peter J. , Malcolm Richard D.
Published: October 2006

Mice were fed an ethanol-containing liquid diet for 9 days. On removal of the diet, exposure to 12 atmospheres absolute of a mixture of helium and oxygen precipitated earlier withdrawal, increased withdrawal scores for the first 6 hours, and increased the peak withdrawal intensity compared to dependent animals exposed to control conditions. The enhanced withdrawal did not appear to reflect alterations in ethanol elimination, oxygen or helium partial pressures, body temperature, or general excitability. These results extend to chronically treated animals the evidence that hyperbaric exposure antagonizes the membrane actions of ethanol.
Anilines: Selective Toxicity to Blue-Green Algae
Authors: Batterton John , Winters Kenneth , Van Baalen Chase
Published: October 2006

The blue-green alga
Agmenellum quadruplicatum
(strain PR6) was very sensitive to aniline and
p
-toluidine (potential environmental toxicants) in an algal lawn assay (the growth of the algal lawn was inhibited with as little as 1 microgram of
p
-toluidine per disk). Assays with seven other species of blue-green algae showed that they had varying sensitivities ranging from 1 to 100 micrograms of
p
-toluidine. Under comparable conditions, 0.5 milligram or more of
p
-toluidine was needed to inhibit a green alga, a diatom, or two species of bacteria.
p
-Toluidine had no immediate effect on the photosynthesis or respiration of
A. quadruplicatum
, although growth was arrested and viability declined.
Smoking Impairs Long-Term Dust Clearance from the Lung
Authors: Cohen David , Arai Satoaki F. , Brain Joseph D.
Published: October 2006

The time for the long-term clearance of dust from human lungs was measured. Three heavy cigarette smokers and nine nonsmokers inhaled a harmless trace amount of magnetic dust, Fe
3
O
4
. From periodic measurements with a sensitive magnetic detector of the amount of this dust remaining in the lungs, a clearance curve was determined for each subject. This magnetic tracer method allows clearance to be safely followed for a much longer time than with radioactive tracer methods. The dust clearance in the smokers is considerably slower than in the nonsmokers. After about a year, 50 percent of the dust originally deposited remained in the lungs of the smokers whereas only 10 percent remained in the lungs of the nonsmokers. The smokers therefore retained five times more dust than the nonsmokers. This impaired clearance of Fe
3
O
4
suggests impaired clearance in smokers of other dusts, such as toxic occupational and urban dusts. The higher retention of these dusts may contribute to the higher incidence of lung diseases in smokers.
Neurotoxic Fragrance Produces Ceroid and Myelin Disease
Authors: Spencer Peter S. , Sterman Arnold B. , Horoupian Dikran S. , Foulds Marion M.
Published: October 2006

Acetyl ethyl tetramethyl tetralin (AETT), a component of soaps, deodorants, and cosmetics, produces hyperirritability and limb weakness in rats repeatedly exposed to the compound. Brain, spinal cord, and peripheral nerves are discolored blue, show progressive neuronal ceroid degeneration, and develop spectacular myelin bubbling. These neurotoxic properties of AETT provide the basis for industry's decision to withdraw the compound from consumer products. In addition, AETT offers the experimentalist a new probe to explore the etiology and pathogeneses of human ceroid and myelin diseases.
Ketone Bodies Are Selectively Used by Individual Brain Regions
Authors: Hawkins Richard A. , Biebuyck Julien F.
Published: October 2006

Close study of 3-hydroxybutyrate uptake by brain suggests that its metabolism is limited by permeability. Furthermore, the permeability characteristics vary from region to region; areas known to have no blood-brain barrier show the highest rate of utilization. The results imply that rather than substitute fuels, ketone bodies should be considered supplements which partially supply specific areas but are incapable of supporting the entire energy requirement of all brain regions.
Geographic Constraints on Women's Careers in Academia
Authors: Marwell Gerald , Rosenfeld Rachel , Spilerman Seymour
Published: October 2006

Male and female academics have very different residence patterns. Women are more concentrated in our largest urban centers; also, wherever they reside, women are less likely than men to change communities when changing institutions. Much of this sex difference is attributable to the constraints under which married academic women must manage their careers, in particular the requirements of two-career households. The authors argue that the status difference between men and women in academia is attributable, in part, to the geographic limitations on the locations of married women, as these prevent making strategic job changes to advance career prospects.
Neural Axis Representing Target Range in the Auditory Cortex of the Mustache Bat
Authors: Suga Nobuo , O'Neill William E.
Published: October 2006

In echolocating bats, the primary cue for determining distance to a target is the interval between an emitted orientation sound and its echo. Whereas frequency is represented by place in the bat cochlea, no anatomical location represents target range. Target range is coded by the time interval between grouped discharges of primary auditory neurons in response to both the emitted sound and its echo. In the frequency-modulated-signal processing area of the auditory cortex of the mustache bat (
Pteronotus parnellii rubiginosus
), neurons respond poorly or not at all to synthesized orientation sounds or echoes alone but respond vigorously to echoes following the emitted sound with a specific delay from targets at a specific range. These range-tuned neurons are systematically arranged along the rostrocaudal axis of the frequency-modulated-signal processing area according to the delays to which they best respond, and thus represent target range in terms of cortical organization. The frequency-modulated-signal processing area therefore shows odotopic representation.
Classification of Opioids on the Basis of Change in Seizure Threshold in Rats
Authors: Cowan Alan , Geller Ellen B. , Adler Martin W.
Published: October 2006

Twenty opioids have been subdivided into four classes by using flurothyl-induced seizures in rats to measure dose-response relationships, stereospecificity, naloxone sensitivity, and tolerance-cross-tolerance. The data support current theories of multiple opiate receptor types. Since the receptors involved mediate effects that are antagonized, enhanced, or unaffected by naloxone, the model is uniquely suitable for detecting novel narcotic antagonists that can then be used to differentiate opiate receptors in other systems.
Movement Disorders of Aged Rats: Reversal by Dopamine Receptor Stimulation
Authors: Marshall John F. , Berrios Norberto
Published: October 2006

When placed in a tank of water, aged rats (24 to 27 months old) showed marked impairments in swimming. Compared with young adult rats (3 to 4 months old), the older animals moved their limbs less vigorously and were less successful in keeping their heads above water. The young, but not old, rats maintained a position nearly horizontal to the water surface and planed across it. These movement dysfunctions of aged rats resemble those seen in young adult animals that have sustained injury to brain dopamine-containing neurons. The swimming impairments of the aged rats were reversed by the dopamine receptor stimulant apomorphine and by the biosynthetic precursor of dopamine, L-dopa. Thus, age-related alterations in brain dopaminergic systems may be responsible for some of the movement disturbances associated with senescence.
Tracing Axons and Axon Collaterals of Spinal Neurons Using Intracellular Injection of Horseradish Peroxidase
Authors: Snow P. J. , Rose P. K. , Brown A. G.
Published: October 2006

Intracellular injection and subsequent histochemical localization of horseradish peroxidase have been used to stain the soma, dendrites, axons, and axon collaterals of spinocervical tract neurons and unidentified dorsal horn neurons in the cat. This technique may be used in combination with the intracellular injection of Procion yellow to demonstrate by light microscopy connections between physiologically typed vertebrate neurons.
Stress-Induced Modulation of the Immune Response
Authors: Monjan Andrew A. , Collector Michael I.
Published: October 2006

After mice were exposed to a daily auditory stressor for varying lengths of time, the responses of their splenic lymphoid cells in vitro were assessed. Both the blastogenic activity of concanavalin A or lipopolysaccharide and the ability of immune lymphocytes to lyse P815 target cells showed the same patterns of immunosuppression and enhancement.
Long-Term Amphetamine Treatment Decreases Brain Serotonin Metabolism: Implications for Theories of Schizophrenia
Authors: Trulson Michael E. , Jacobs Barry L.
Published: October 2006

Long-term amphetamine administration to cats (a mean of 8.75 milligrams per kilogram twice daily for 10 days) produced large decreases (40 to 67 percent in serotonin and its major metabolite, 5-hydroxyindoleacetic acid, in all brain regions examined. This treatment also produced several behaviors that are dependent on depressed central serotonergic neurotransmission, and which normally are elicited exclusively by hallucinogenic drugs. Short-term amphetamine administration (15 mg/kg) did not produce these behaviors and resulted in small decreases in brain serotonin and no change in 5-hydroxyindoleacetic acid. These data are discussed in the context of monoamine theories of schizophrenia.
Jaundice Phototherapy: Micro Flow-Cell Photometry Reveals Rapid Biliary Response of Gunn Rats to Light
Authors: McDonagh Antony F. , Ramonas Lori M.
Published: October 2006

Hepatic pigment clearance in rats can be followed continuously with photometric detectors designed for high-pressure liquid chromatography. This method showed that light has a fast effect on bilirubin metabolism in homozygous Gunn rats, even at low doses and intensities. This is consistent with geometric isomerization of bilirubin IXα as a primary step in phototherapy.
On the X-ray Diffraction Effects from Solid Fatty Acids
Authors: Wyckoff Ralph W. G. , Hunt Franklin L. , Merwin Herbert E.
Published: October 2006

Powder reflections, as well as single face reflections of large spacing, have been obtained from palmitic and other fatty acids. Single specimens with all the optical properties of a crystal and giving the same large spacing X-ray reflections as solidified films on glass have been grown from solution of palmitic acid in acetone. This acid, at least, therefore appears to be truly crystalline under these conditions and not in a "smectic" or other sub-crystalline state. Since the X-ray data from this acid are strictly analogous to those from other typical "smectic" substances, it seems necessary further to conclude that no definite X-ray evidence yet exists for this "smectic" state.

The symmetry of palmitic acid is either monoclinic or triclinic and the long carbon chains are not normal to the face producing the large spacing reflections. Such spacings are therefore not direct measures of the lengths of these chains.

By growing single plates of the acid from solution more intense reflections from the long spacings have been obtained than from films made by solidifying the acid on glass or mica. Such single crystals may prove especially useful as gratings in long wave length X-ray spectrography.
Glutamine Synthetase: Assimilatory Role in Liver as Related to Urea Retention in Marine Chondrichthyes
Authors: Webb James T. , Brown G. W.
Published: October 2006

The levels of glutamine synthetase specific activity in hepatic and renal tissue are higher in fish that are ureosmoregulators than in those that are not. Enzyme activities in the liver and kidney of 18 species of fish correlated directly with the ureosmoregulatory adaptation of each species.
Pharmacologic Effects in Man of a Specific Serotonin-Reuptake Inhibitor
Authors: Lemberger Louis , Rowe Howard , Carmichael Ralph , Oldham Samuel , Horng Jong S. , Bymaster Frank P. , Wong David T.
Published: October 2006

Fluoxetine (Lilly 110140) caused a 63 percent inhibition of [
3
H]serotonin uptake into platelets obtained from normal volunteers to whom the drug was administered daily for 7 days. This dose had no effect on the usual pressor response produced by injections of norepinephrine or tyramine.
Neural Correlate of Behavioral Plasticity in Command Neurons of
Pleurobranchaea
Authors: Davis William J. , Gillette Rhanor
Published: October 2006

Food stimuli normally excite the command neurons of
Pleurobranchaea
that cause feeding. In contrast, the same food stimuli selectively inhibit these neurons in specimens that have been trained to suppress feeding and withdraw from food by means of an avoidance conditioning paradigm consisting of paired food and conditional shock. Food stimuli excite the feeding command neurons of yoked control specimens exposed to unpaired food and shock, but inhibit the feeding command neurons of untrained specimens that have been satiated with food. These results suggest that the command neurons serve as a neural locus at which an animal's behavior is modulated by past experiences. These results also establish a neural correlate of behavioral plasticity, in the form of synaptic inhibition of the command neurons.
Metkephamid, a Systemically Active Analog of Methionine Enkephalin with Potent Opioid δ-Receptor Activity
Authors: Frederickson Robert C. A. , Smithwick Edward L. , Shuman Robert , Bemis Kerry G.
Published: October 2006

Metkephamid is an analog of methionine enkephalin that retains high affinity for the δ receptor and is a systemically active analgesic. Since it is at least 100 times more potent than morphine as an analgesic when placed directly into the lateral ventricles, and is 30 to 100 times more potent on the δ receptor and yet is roughly equipotent on the μ receptor in vitro, it is concluded that it probably produces analgesia by action on δ receptors as well as, or rather than, on μ receptors. It has less tendency to produce respiratory depression, tolerance, and physical dependence than standard analgesics, and it is presently undergoing clinical trial.
Adenosine 3′,5′-Monophosphate Waves in
Dictyostelium discoideum
: a Demonstration by Isotope Dilution—Fluorography
Authors: Tomchik K. J. , Devreotes P. N.
Published: October 2006

The distribution of adenosine 3′,5′-monophosphate (cyclic AMP) in fields of aggregating amoebae of
Dictyostelium discoideum
was examined by a novel isotope dilution-fluorographic technique. Cellular cyclic AMP was visualized by its competition with exogenous
3
H-labeled cyclic AMP for high-affinity binding sites on protein kinase immobilized on a Millipore filter used to blot the monolayer. The cyclic AMP was distributed in spiral or concentric circular wave patterns which centered on the foci of the aggregations. These patterns were correlated with those of cell shape change that propagate through the monolayers: cells in regions of high concentrations of cyclic AMP were elongated (presumably moving up a cyclic AMP gradient), whereas those in regions of low cyclic AMP concentrations were randomly directed. The highest cyclic AMP concentrations were about 10
-6
M
. The widths of the regions of elevated cyclic AMP were about 0.3 to 1 millimeter which, assuming a wave velocity of 300 micrometers per minute, suggests that a cell signals for about 1 to 3 minutes. These observations support the hypothesis that the aggregation process in
Dictyostelium
is mediated by the periodic relay of cyclic AMP signals and suggest a simple scheme for the dynamics of the aggregation process.
Warburg Effect Revisited: Merger of Biochemistry and Molecular Biology
Authors: Racker Efraim , Spector Mark
Published: October 2006

Over 50 years ago Warburg discovered that malignant cancers ferment glucose to lactic acid much more rapidly than most normal cells. In analyzing this phenomenon in a variety of tumors we found one common denominator: a high rate of adenosine triphosphate hydrolysis that delivers the adenosine diphosphate (ADP) and inorganic phosphate (P
i
) required for glycolysis. However, the source of adenosinetriphosphatase (ATPase) activity varies; in some cells it is the sodium- and potassium-dependent ATPase, in others the mitochondrial ATPase, and in some perhaps a viral ATPase. In Ehrlich ascites tumor cells the sodium and potassium pump of the plasma membrane operates inefficiently. For each sodium ion pumped out of the cell, several ATP molecules are hydrolyzed. Thus, ADP and P
i
, which are rate-limiting for glycolysis, are generated and permit the rapid formation of lactic acid. The Na
+
, K
+
pump consists of two subunits. The α subunit contains the active center of the ATPase enzyme and the β subunit is a glycoprotein with unknown function. The pump is rendered inefficient by phosphorylation of the β subunit catalyzed by a protein kinase, PK
M
, which is present in the plasma membrane of the tumor. This protein kinase is activated in turn by a cascade of the three other kinases PK
S
, PK
L
, and PK
F
. The PK
F
is immunologically related to the
src
gene product of Rous sarcoma virus. Each of the members of the protein kinase cascade phosphorylate other protein substrates, including components of the cytoskeleton. This may help to explain the remarkable pleiotropic manifestations of a transformation event controlled by a single gene.
Protons and Anaerobiosis
Authors: Hochachka Peter W. , Mommsen Thomas P.
Published: October 2006

During oxygen limitation in animals, glucose can be fermented via several metabolic pathways varying in energetic efficiency and leading to various end products (such as lactate, alanopine, octopine, succinate, or propionate). Because of opposite
p
H dependencies of proton production by fermentation and by hydrolysis of adenosine triphosphate formed in the fermentation, the total number of moles of protons generated is always two per mole of the fermentable substrate. However, two and three times more adenosine triphosphate can be turned over per mole of protons produced in succinate and propionate fermentations, respectively, than in lactate fermentation.
Separation of Signal Transduction and Adaptation Functions of the Aspartate Receptor in Bacterial Sensing
Authors: Russo Andrew F. , Koshland Daniel E.
Published: October 2006

In order to investigate the functions of stimulus recognition, signal transduction, and adaptation, the aspartate receptor gene for bacterial chemotaxis in
Salmonella typhimurium
has been sequenced and modified. A carboxyl-terminal truncated receptor was shown to bind aspartate and to transmit a signal to change motility behavior. However, the truncated receptor showed greatly reduced methyl-accepting capacity, and did not allow adaptation to the sensory stimulation. The separation of receptor functions by alteration of primary structure emphasizes that the receptor is directly involved in adaptation and is not solely a device for transmitting a signal across a membrane.
Light-Enhanced Free Radical Formation and Trypanocidal Action of Gentian Violet (Crystal Violet)
Authors: Docampo Roberto , Moreno Silvia N. J. , Muniz Ramiro P. A. , Cruz Fernando S. , Mason Ronald P.
Published: October 2006

Transmission of Chagas' disease by transfusion of blood containingTrypanosoma cruzihas often been reported, and gentian violet, a triarylmethane dye, is widely used by blood banks in attempts to eliminate such transmission. In a study of intact trypanosomes, gentian violet was found to undergo a one-electron reduction to produce a carbon-centered free radical as demonstrated by electron spin resonance spectroscopy. Either reduced nicotinamide adenine dinucleotide or the reduced dinucleotide phosphate could serve as a source of reducing equivalents for the production of this free radical by homogenates ofTrypanosoma cruzi. The formation of this free radical, and the trypanocidal action of gentian violet, were enhanced by light. The enhanced free radical formation may be the basic cause of the selective toxicity of gentian violet toTrypanosoma cruzi.
T-Cell Growth Factor Gene: Lack of Expression in Human T-Cell Leukemia-Lymphoma Virus-Infected Cells
Authors: Arya Suresh K. , Wong-Staal Flossie , Gallo Robert C.
Published: October 2006

Activated mature T cells require T-cell growth factor (TCGF) for continuous proliferation. However, many mature T cells infected with human T-cell leukemia-lymphoma virus grow independently of exogenously added TCGF. It is now reported that cells infected with this virus also lack detectable TCGF messenger RNA (less than one copy per cell) and thus do not produce their own growth factor. The results apparently rule out an autostimulation mechanism of growth control.
New Applications of Microbial Products
Authors: Demain Arnold L.
Published: October 2006

Microbial secondary metabolites are now being used for applications other than as antibacterial, antifungal, and antitumor agents. These applications include use against parasites (coccidia, helminths) and insects as well as for animal and plant growth stimulation, immunosuppression, uterocontraction, and other pharmacological activities. Further applications are possible in various areas of pharmacology and agriculture, a development catalyzed by the use of simple enzyme assays for screening prior to testing in intact animals or in the field.
Expert Systems Research
Authors: Duda Richard O. , Shortliffe Edward H.
Published: October 2006

Artificial intelligence, long a topic of basic computer science research, is now being applied to problems of scientific, technical, and commercial interest. Some consultation programs, although limited in versatility, have achieved levels of performance rivaling those of human experts. A collateral benefit of this work is the systematization of previously unformalized knowledge in areas such as medical diagnosis and geology.
Attenuation of Amnesia in Rats by Systemically Administered Enkephalins
Authors: Rigter Henk
Published: October 2006

The pentapeptides methionine-enkephalin and leucine-enkephalin are both able to reduce experimentally induced amnesia in rats. In contrast to the possible analgesic activity of these peptides, the anti-amnesic effect is seen after systemic administration of dosages of 30 micrograms or lower. The nature of the anti-amnesic effect is different for the two peptides.
Isolated Chromaffin Cells from Adrenal Medulla Contain Primarily Monoamine Oxidase B
Authors: Youdim Moussa B. H. , Banerjee Dipak K. , Pollard Harvey B.
Published: October 2006

Cultured chromaffin cells from bovine adrenal medulla were found to contain primarily the B form of monoamine oxidase. This monoamine oxidase B enzyme was somewhat distinct from B enzymes from other sources, in that noradrenaline was a much poorer substrate than serotonin. Nonetheless, studies with selective inhibitors of the A form (clorgyline) and the B form [(-)-deprenyl] confirmed that chromaffin cell monoamine oxidase was the B form. The observation that chromaffin cell monoamine oxidase has poor affinity for catecholamines is consistent with physiological needs that require the cell to synthesize and store large amounts of catecholamines.
Synapsin I in Nerve Terminals: Selective Association with Small Synaptic Vesicles
Authors: Navone F. , Greengard P. , De Camilli P.
Published: October 2006

Immunocytochemistry revealed that synapsin I is preferentially (and possibly exclusively) associated with small (40- to 60-nanometer) synaptic vesicles and not with large (greater than 60-nanometer) dense-core vesicles in bovine hypothalamus. These observations may explain why synapsin I is found exclusively in neurons, since small synaptic vesicles are specific to neurons whereas large dense-core vesicles in neurons may be considered the equivalent of secretory organelles in endocrine cells.
Retarding Effect of Lowered Heart Rate on Coronary Atherosclerosis
Authors: Beere Polly A. , Glagov Seymour , Zarins Christopher K.
Published: October 2006

The role of heart rate in the development of coronary atherosclerosis was assessed in adult male cynomolgus monkeys (
Macaca fascicularis
). Heart rate was lowered in six animals by surgical ablation of the sinoatrial node. A sham procedure, which included all of the surgical steps except for sinoatrial node ablation, was carried out in eight animals. All of the monkeys were fed an atherogenic high cholesterol diet for 6 months, and heart rates were monitored repeatedly by telemetry during 24-hour test periods. Coronary atherosclerosis in animals with postoperative heart rates less than the preoperative mean for all of the animals that underwent surgery was less than half that of animals with heart rates above the mean or of diet-fed control animals not subjected to surgery. Groups did not differ in blood pressure, serum lipids, or body weight. These results suggest that heart rate in itself may contribute to the mechanisms by which behavioral patterns and physical training influence coronary artery disease.
Antipyretic Potency of Centrally Administered α-Melanocyte Stimulating Hormone
Authors: Murphy M. T. , Richards D. B. , Lipton J. M.
Published: October 2006

Centrally administered α-melanocyte stimulating hormone is much more potent in reducing fever than the widely used antipyretic acetaminophen. This finding supports the hypothesis that the endogenous neuropeptide has a role in the limitation of fever and suggests that it may be clinically useful as an antipyretic.
Quantitation of Hindered Rotations of Diphenylhexatriene in Lipid Bilayers by Differential Polarized Phase Fluorometry
Authors: Lakowicz J. R. , Prendergast F. G.
Published: October 2006

Diffusional motions of 1,6-diphenyl-1, 3, 5-hexatriene (DPH) were observed by differential polarized phase fluorometry. The measurements indicated that the depolarizing rotations of DPH in propylene glycol are isotropic. The results in vesicles of dimyristoyl-L-α-phosphatidylcholine indicated that diffusional rotations of DPH are dominated by hindered torsional motions. Combined use of both differential phase and steady-state anisotropy measurements showed that the average rotational angle of DPH, at times long compared to the fluorescence lifetime, is limited to about 23° at temperatures below the transition temperature of the lipid and that these rotations become less hindered above the transition temperature. The evidence that the depolarizing rotations of DPH in a lipid bilayer are different from those in an isotropic solvent calls into question the meaning of membrane microviscosity as determined by fluorescence anisotropy.
Loss of Hippocampal Theta Rhythm Results in Spatial Memory Deficit in the Rat
Authors: Winson Jonathan
Published: October 2006

Rats learned, using distal room cues, to run to a goal on an elevated, circular track starting from any position on the track. The goal was one of eight equidistant, recessed cups set around the track, the goal cup being distinguished from the others solely by its position in the room. After learning, electrolytic lesions were made in the medial septal nucleus eliminating hippocampal theta rhythm in some animals but not in others. Rats without theta rhythm were no longer able to perform the spatial task, whereas rats with undisturbed theta rhythm retrained normal performance. Although rats without theta rhythm could not find their way directly to the goal, they recognized its location when they came upon it by chance. This type of spatial deficit appears similar to that shown by hippocampally lesioned patient H.M. Subsequent tests demonstrated that rats deprived of theta rhythm before training could nevertheless learn the task.
T and Tn, General Carcinoma Autoantigens
Authors: Springer Georg F.
Published: October 2006

Primary and metastatic carcinomas are epithelial in origin and comprise by far the largest group of malignant tumors in humans. In most of these tumors, T and Tn antigens, whose epitopes have been synthesized, are uncovered and immunoreactive. In all other tissues T and Tn antigens are masked and not accessible to the immune system; they are generally precursors in normal complex carbohydrate chains. Thus, carcinomas have antigens recognized as foreign by the patients' immune system. The expression of T and Tn antigens has pathogenic and clinical consequences, and the antigens themselves are powerful histological markers in carcinoma diagnosis and frequently in prognosis. Most patients distinguish their carcinoma from all other cells, as shown by strong autoimmune responses to T antigen. These responses are readily measured by assays, and they allow detection of carcinomas with greater sensitivity and specificity frequently earlier than previously possible. Moreover, the extent of T and Tn expression often correlates with carcinoma differentiation; on a molecular level, clustered T- and Tn-active structures on carcinoma cell surfaces may be involved in invasion.
Vestibulospinal Reflexes as a Function of Microgravity
Authors: Reschke Millard F. , Anderson David J. , Homick Jerry L.
Published: October 2006

The idea that sustained microgravity will result in altered otolith input requiring a modification of postural control was explored by using the pathway that links the otolith organs and spinal motoneurons. Two related methods were used. First, the Hoffmann reflex was used to measure at specific times the excitability of the soleus-spinal motoneuron pool during a brief unexpected linear acceleration. Second, extensive dynamic postural testing with a moving platform was done before and after flight. The Hoffmann reflex amplitude, reflecting otolith-modulated motoneuron sensitivity, was low in flight after adaptation, and its postflight potentiation may have been dependent on rate of adaptation. The strength of inflight motion sickness symptoms was related to postflight Hoffmann reflex amplitude. Dynamic posture tests showed significant deviations from the results obtained before flight. The strategy used for balance on the moving platform was modified, and the behavior of the subjects suggested a decrease in awareness of the direction and magnitude of the motion.
Left Ventricular Receptors Inhibit Brain Serotonin Neurons During Coronary Artery Occlusion
Authors: Sole Michael J. , Van Loon Glen R. , Shum Andrew , Lixfield Wolfgang , MacGregor David C.
Published: October 2006

Acute coronary artery ligation in pargyline-treated rats decreased serotonin and increased 5-hydroxyindoleacetic acid in the medulla and posterior hypothalamus. Lidocaine applied topically to the left ventricle completely prevented these alterations. No changes in serotonin were observed in the other brain regions examined. These data suggest a reflex inhibition of bulbar and hypothalamic serotonergic nerves by left ventricular receptors following acute coronary artery occlusion in the rat.
Cultivation in Vitro of the Quartan Malaria Parasite
Plasmodium inui
Authors: Nguyen-Dinh Phuc , Campbell Carlos C. , Collins William E.
Published: October 2006

The simian quartan malaria parasite
Plasmodium inui
(OS strain) was cultured in a continuous flow system with rhesus monkey erythrocytes and RPMI 1640 medium supplemented with Hepes buffer and rhesus serum. Over a 10-week period, the growth of the parasite permitted a 61,000-fold cumulative dilution of the original inoculum. After 5 weeks in culture, the parasites were still infective to the monkey
Saimiri sciureus
and to
Anopheles freeborni
mosquitoes.
Isolation of Chlorine-Containing Antibiotic From the Freshwater Cyanobacterium
Scytonema hofmanni
Authors: Mason C. P. , Edwards K. R. , Carlson R. E. , Pignatello J. , Gleason F. K. , Wood J. M.
Published: October 2006

Scytonema hofmanni
, a filamentous freshwater cyanobacterium (blue-green alga), produces secondary metabolites which inhibit the growth of other cyanobacteria and green algae. A rapid, qualitative assay for this inhibition has been developed with Synechococcus as the test organism. This assay procedure has led to the isolation and characterization of an antibiotic (named cyanobacterin) from
Scytonema
. The antibiotic has a molecular weight of 430 and an empirical formula of C
23
H
23
O
6
Cl and contains a γ-lactone and a chlorinated aromatic nucleus. It inhibits the growth of various algae but has limited effect on nonphotosynthetic bacteria or protozoans and thus may have potential use as a specific algicide.
Role of Calcium in Trypanocidal Drug Action
Authors: Clarkson AB , Amole BO
Published: October 2006

The synergistic effect of serum on the drug combination of salicylhydroxamic acid plus glycerol, which is active against
Trypanosoma brucei
, is due to diffusible calcium ions. The synergistic activity can be removed by dialysis of the serum or by addition of calcium chelating agents. A buffer containing calcium can mimic the synergistic activity of serum. This finding may have important implications in the clinical management of African trypanosomiasis in humans. Calcium also has a synergistic effect on melarsoprol, the only drug available for treating sleeping sickness patients with central nervous system involvement, and the concentration of calcium has been reported to be depressed in the serum of experimentally infected animals.
Polyamine Depletion Influences Drug-Induced Chromosomal Damage
Authors: Tofilon Philip J. , Oredsson Stina M. , Deen Dennis F. , Marton Laurence J.
Published: October 2006

Polyamines have been implicated in the intracellular stabilization of DNA. Depletion of intracellular polyamines influences the cytotoxicity of 1,3-bis(2-chloroethyl)-1-nitrosourea and cis-diamminedichloroplatinum II. By means of the sister chromatid exchange assay, it was found that intracellular polyamine depletion can also alter the induction of chromosomal damage by these cytotoxic agents.
Conditioned Cues Elicit Feeding in Sated Rats: A Role for Learning in Meal Initiation
Authors: Weingarten Harvey P.
Published: October 2006

Pavlovian conditioning was used to teach rats an association between an arbitrary external cue and food. Presentation of the conditioned cue elicited feeding by sated animals. The meal constituted approximately 20 percent of daily intake, and it was compensated for by a reduction of subsequent intake.
Children Absorb Tris-BP Flame Retardant from Sleepwear: Urine Contains the Mutagenic Metabolite, 2,3-Dibromopropanol
Authors: Blum Arlene , Gold Marian Deborah , Ames Bruce N. , Kenyon Christine , Jones Frank R. , Hett Eva A. , Dougherty Ralph C. , Horning Evan C. , Dzidic Ismet , Carroll David I. , Stillwell Richard N. , Thenot Jean-Paul
Published: October 2006

The flame retardant, tris(2,3-dibromopropyl)phosphate (tris-BP), which is a mutagen and causes cancer and sterility in animals is absorbed from fabric by people. 2,3-Dibromopropanol, a metabolite of tris-BP and a mutagen itself, has been found in the urine samples of ten children who were wearing or who had worn tris-BP-treated sleepwear. Eight of these children were wearing well-washed sleepwear and the possibility of absorption of tris-BP from well-washed sleepwear is discussed. 2,3-Dibromopropanol was not found in the urines of one child and one adult who had never worn tris-BP-treated garments.
Running and Breathing in Mammals
Authors: Bramble Dennis M. , Carrier David R.
Published: October 2006

Mechanical constraints appear to require that locomotion and breathing be synchronized in running mammals. Phase locking of limb and respiratory frequency has now been recorded during treadmill running in jackrabbits and during locomotion on solid ground in dogs, horses, and humans. Quadrupedal species normally synchronize the locomotor and respiratory cycles at a constant ratio of 1:1 (strides per breath) in both the trot and gallop. Human runners differ from quadrupeds in that while running they employ several phase-locked patterns (4:1, 3:1, 2:1, 1:1, 5:2, and 3:2), although a 2:1 coupling ratio appears to be favored. Even though the evolution of bipedal gait has reduced the mechanical constraints on respiration in man, thereby permitting greater flexibility in breathing pattern, it has seemingly not eliminated the need for the synchronization of respiration and body motion during sustained running. Flying birds have independently achieved phase-locked locomotor and respiratory cycles. This hints that strict locomotor-respiratory coupling may be a vital factor in the sustained aerobic exercise of endothermic vertebrates, especially those in which the stresses of locomotion tend to deform the thoracic complex.
Dicarboxylic Aciduria: Deficient [1-
14
C]Octanoate Oxidation and Medium-Chain Acyl-CoA Dehydrogenase in Fibroblasts
Authors: Rhead William J. , Amendt Brad A. , Fritchman Kathie S. , Felts Sara J.
Published: October 2006

Dicarboxylic aciduria, an inborn error of metabolism in man, is thought to be caused by defective β-oxidation of six-carbon to ten-carbon fatty acids. Oxidation of [1-
14
C]octanoate was impaired in intact fibroblasts from three unrelated patients with dicarboxylic aciduria (19 percent of control), as was the activity of medium-chain (octanoyl-)acyl-CoA dehydrogenase in the supernatants of sonicated fibroblast mitochondria (5 percent of control). These data confirm that dicarboxylic aciduria is caused by an enzyme defect in the beta-oxidation cycle.
Angiotensin Synthesis in the Brain and Increased Turnover in Hypertensive Rats
Authors: Ganten D. , Hermann K. , Bayer C. , Unger Th. , Lang R. E.
Published: October 2006

The missing link in the evidence for an active endogenous renin angiotensin system in the brain has been the demonstration of local angiotensin synthesis in the central nervous system in vivo. In this report the extraction and characterization of angiotensin I and angiotensin II from the brain of rats is described. The accumulation of angiotensin I was enhanced in hypertensive rats when the conversion to angiotensin II was blocked in vivo by the converting enzyme inhibitor captopril.
Manufactured Hexaparental Mice Show That Adults Are Derived from Three Embryonic Cells
Authors: Markert Clement L. , Petters Robert M.
Published: October 2006

Two female chimeric mice have been produced by aggregates of three genetically marked eight-cell embryos. All three embryonic genotypes are clearly expressed in the pigment pattern of the adults. These hexaparental mice together with their littermates demonstrate that, in the 64-celled blastocyst, at least three cells, and probably only three, are the source of all adult tissues.
The Effect of X-Rays on Bacteria
Authors: Clark George L. , Boruff C. S.
Published: October 2006

(1) X-rays act like sterilizing agents upon cultures of
B. coli
and
Erythrobacillus prodigiosus,
in that the curves are characteristic sterilization or death-rate curves showing that the total counts decrease logarithmically with time.

(2) In this experiment
B. coli
did not show variation or mutation when it was treated with X-rays.

(3) With increasing irradiation
Erythrobacillus prodigiosus
showed a tendency toward lack of ability to produce its characteristic red pigment. By allowing the organism to grow on the plate for a period of five days the greater portion of the colonies produced their pigment. If a transfer of a white colony is made to an agar slant the characteristic pigment is produced in twelve hours. In only one case was it necessary to make a second transfer in order to bring about the development of the pigment. The above is another example of the variation tendency of
Erythrobacillus prodigiosus.