bluuebunny/crossref_metadata_2025_split huggingface dataset:
RD114‐pseudotyped retroviral vectors kill cancer cells by syncytium formation and enhance the cytotoxic effect of the TK/GCV gene therapy strategy
Authors: Germain E. , Roullin V.‐G. , Qiao J. , de Campos Lima P. O. , Caruso M. 
Published: January 2005

AbstractBackgroundWild‐type RD114 virus is capable of generating syncytia during its replication, and it is believed that cell‐free viruses direct the fusion of neighboring cells. The RD114 envelope (Env) that mediates this fusion event is now widely used to pseudotype retroviral and lentiviral vectors in gene therapy. Indeed, vectors pseudotyped with RD114 Env are very efficient to transfer genes into human hematopoietic cells, and they are resistant to human complement inactivation. In this study, we have tested the potential of RD114‐pseudotyped vectors produced from the FLYRD18 packaging cell line to induce syncytia.MethodsRD114‐pseudotyped vectors produced from the FLYRD18 packaging cells were added on tumor cell lines, and the formation of syncytia was assessed by microscopy after cell fixation and methylene blue staining. The kinetics of syncytium formation was analyzed by time‐lapse microscopy. Finally, the cytotoxic effect of RD114‐pseudotyped vectors was measured by the MTT assay on tumor cells, and in combination with the TK/GCV strategy.ResultsWe have found that these vectors were able to mediate cell‐to‐cell fusion of human tumor cell lines. A few hours after addition of the vector, cells started to aggregate to form syncytia that eventually evolved toward cell death 48 h postinfection. RD114‐pseudotyped vectors were very efficient at killing human cancer cells, and they were also able to enhance dramatically the cytotoxic effect of the TK/GCV strategy.ConclusionsThese findings indicate that RD114‐pseudotyped vectors used alone, or in combination with a suicide gene therapy approach, have great potential for the treatment of cancer. Copyright © 2004 John Wiley & Sons, Ltd.
Evidence for differential function of neuronal and glial cell in protein metabolism and amino acid transport
Authors: Hamberger Anders , Babitch Joseph A. , Blomstrand Christian , Hansson Hans‐Arne , Sellströ Åke 
Published: January 2005

AbstractAmino acid incorporation in neuronal and glial cells has been investigated in several laboratories employing bulk‐separation techniques to obtain cell‐enriched fractions. The relative rates of incorporation into the proteins of both cell types vary substantially with the method of isotope administration. Through the use of single‐pulse perfusions with a duration of 30–40 sec the early time course of labeling has been studied. The difference between neuronal and glial cells with respect to indicating cell interactions will be discussed. The in vitro amino acid incorporation has been measured in neurons and glia after slice incubation. In material from animals developing experimental allergic encephalitis the rate of 3H‐leucine incorporation more than doubles in the unfractionated brain. Glial cells increased their rate of incorporation by approximately 400%under the same conditions. The involvement of specific proteins in the cells and organelles has been studied by gel electrophoresis. The high uptake capacity of glial cells for certain amino acids with possible transmitter functions has been further characterized. The release of these substances is measured in a superfusion system where beds of cells, preloaded with the labeled substance, are used. High potassium pulses stimulate release of, for example GABA in both neuronal and glial cells.
Alterations of central nervous system protein synthesis in response to spinal cord hemisection
Authors: Luttge William G. , Mannis Mark J. , Bernstein Jerald J. 
Published: January 2005

AbstractThis investigation explores the central nervous system protein‐synthetic responses to hemisection of the spinal cord. Adult male rats hemisected at mid T2 were given intravenous injections of 14C‐leucine at 0, 7, 30, or 70 days postoperative. Four hours later the T1, T2, T3, and C6 segments of the spinal cord and right and left samples of somatomotor and occipital cortex were removed, weighed, and frozen. These samples were later homogenized ad subjected to trichloroacetic acid (TCA) separations. Protein‐synthetic activity was expressed as the ratio of the specific activity of the TCA precipitable proteins to the specific activity of the TCA free amino acid pool.In the spinal cord samples protein‐synthetic activity was greater than in controls at 7 and 30 days postoperative in the T2 segment and at 30 days postoperative in the C6 and T3 segments. In the cortical samples protein‐synthetic activity was greater than in controls in the right and left somatomotor somatomotor cortex at 70 days postoperative. Thus, T2 hemisection leads to initial increases and subsequent decreases in protein‐synthetic activity in both spinal cord and somatomotor cortex. These results are discussed in terms of possible regenerative neural reactions occurring in the central nervous system following spinal cord injury.
Central adrenergic neurons in DOCA‐salt hypertension
Authors: Lamprecht Friendhelm , Jacobowitz David M. , Richardson J. Steven , Kopin Irwin J. 
Published: January 2005

AbstractThe effects of various doses of 6‐hydroxydopamine(6‐OHDA) injected into the hypothalamus on DOCA‐salt‐induced hypertension were studied. The development of hypertension was prevented in the group treated with the highest dose of 6‐OHDA, and the onset of hypertension was delayed in a dose‐dependent fashion in the groups treated with the lower doses of 6‐OHDA. Catecholamine histofluorescence observations showed that the cannula tips placed the drug lateral to the third ventricle. The most prominent change observed was a marked unilateral reduction in the fluorescence of the dopaminergic nerves of the caudate‐putamen and in the number of cell bodies in the substantia nigra. These results suggest possible sites of central aminergic control of blood pressure.
Neurochemical changes in the cat's spinal cord due to orthodromic tetanic stimuli. I: Phospholipids
Authors: Althasu H.‐ H. , Neuhoff V. , Haase J. , Ross H.‐G. 
Published: January 2005

AbstractPosttetanic potentiation of monosynaptic reflexes has been used as a paradigm for neuronal plasticity. The explanation for this phenomenon is an increased responsiveness of the synaptic junctions. This would basically required chemical changes of the nervous structures involved. The ventral horn area of the spinal cord was therefore analyzed neurochemically. The determination of the phospholipids revealed an alteration of their composition. Sphingomyelin, phosphatidylcholine and phosphatidylinositide/serine behaved differently, whereas phosphatidylethanolamine and the total phospholipid content remained unchanged.
Consummatory behavior as a function of ambient temperature in septal‐lesioned and control rats
Authors: Sanes J. , Donovick P. J. , Burright R. G. 
Published: January 2005

AbstractSeptal lesions or control operations were produced in male and female rats. Measurements of water and food consumption were carried out while the rats were housed under warm vivarium temperatures (24°C) and when maintained in a cold room (6°C). Examination of the data from the entire week spent in the cold revealed that rats with septal lesions deviated from precold water‐consumption levels less than comparable control rats. Further, whereas rats with septal lesions suppressed intake for the first 24 hr following either shift in environmental temperatures, control animals inhibited drinking only when returned to the warm environment. Both surgical groups elevated food consumption in the cold. The relative amount of food and water consumed during the day (vs night) increased for all groups when maintained in the cold. Differences in degree of reactivity to the manipulations were observed in male and female rats. These findings were interpreted as adding further support to our contention that septal lesions alter the behavior (rather than direct metabolic) adaptations an animal makes to its environment.
Single‐cell responses associated with rhythmic slow‐wave potentials in rat superior colliculi
Authors: Anderson Kenneth V. , O'Steen W. Keith 
Published: January 2005

AbstractThe present study was designed to investigate the features of rhythmic slow‐wave potentials in the superior colliculi of rats and to study the relationship between these potentials and the activity of single collicular neurons. In contrast to studies in other portions of the visual system, rhythmic slow‐wave potentials in the colliculi fell within a single limited range of frequencies from 9 to 26 cycle/sec. Single‐cell recordings revealed that numerous collicular neurons were also responding rhythmically, with discharge frequencies generally coinciding with those established for collicular slow‐wave potentials. In some animals slow‐wave and single‐cell potentials were recorded simultaneously through adjacent electrodes, and in all instances the frequency of discharge of single neurons coincided with the frequency of oscillation of the slow‐wave potentials. These data suggest the rhythmic postsynaptic potentials in individual collicular neurons may be the mechanism by which rhythmic slow‐wave potentials are generated.
Binding of γ‐aminobutyric acid and taurine to synaptosomal fractions of regions of the feline CNS
Authors: Gadea‐Ciria Manuel , García‐Gracia Manuel , Camacho Juan Gervas , Somoza Gene , Balfagón Gloria , DeFeudis Francis V. 
Published: January 2005

AbstractThe “binding” of 3H‐γ‐aminobutyric acid (3H‐GABA) and 14C‐taurine (7 × 10−5M) to synaptosomal fractions of the feline CNS was studied using differential centrifugation and double‐isotope methods. Of the regions examined, the “binding” of GABA (in nmole /mg protein) occurred to the greatest extent, in cerebral cortex, olfactory bulb, and colliculi and, to a lesser extent, in caudate nucleus, corona radiata, and fornix. Distribution ratios revealed that GABA binding was greater in the cerebral cortex than in caudate nucleus, brain stem, spinal cord, and white matter regions. The binding of taurine (in nmole/mg protein) was lowest in cerebral cortex and highest in brain stem and spinal gray regions. Distribution ratios for taurine indicated that its accumulation was similar in all CNS regions studied, except for slightly higher values for cerebellar cortex and fornix. These results indicated that preferential binding of both GABA and taurine exists among regions of the feline CNS.
A psychoneural model of visual contrast
Authors: Hirsch Henry R. , Gibson John M. 
Published: January 2005

AbstractA typical set of visual contrast data can be described by a function which relates brightness responses to the luminance stimulus provided by a target that is viewed against an illuminated surround. This brightness‐luminance function is represented by a psychoneural visual‐contrast model having two channels, one corresponding to the brightness of the target and the other to the brightness of the surround. The principal ascending and descending pathways in each channel are represented by a submodel which is equivalent to the intensity‐perception model described by MacKay. The interaction between the channels, which accounts for the perception of contrast, takes the form of nonlinear lateral inhibition. Brightness responses calculated with the use of the pshychoneural contrast model correspond very closely to the data upon which the brightness‐luminance function is based.
Effects of small organic molecules on the cholinergic receptors of the motor endplate
Authors: Saji Y. , del Castillo J. 
Published: January 2005

AbstractThis paper deals with the effects on the endplate receptors of the electro‐osmotic and bath application of compounds which, although lacking pharmacological affinity, mimic the actions caused at much lower concentrations by conventional cholinergic drugs. Small cyclic molecules containing carbonyl, ether, ester, amide, and carboxyl anhydride groups were tested. Lactones, carboxyl anhydrides, cyclic amides, and ketones depolarized the endplate membrane and, in addition, most of them potentiated the depolarizing action of acetylcholine. On the contrary, cyclic ethers behaved as neuromuscular blocking agents. Dioxane, which contains two ether oxygens, caused a marked prolongation of the time course of the potentials elicited by the iontophoretic application of acetylcholine pulses. In some instances the effects of adding the compounds to the bath were different from those observed following local electro‐osmotic application.
Prolonged unit responses in thalamic reticular, ventral, and posterior nuclei following lateral hypothalamic and midbrain reticular stimulation
Authors: Keene James J. 
Published: January 2005

AbstractIn unanesthetized postcollicular cerveau isolé rats, prolonged responses over 10 sec periods following intracranial stimulation (0.2 sec, 100 Hz, 0.5 msec, 600 μA cathodal pulses) were studied with extracellular recordings of 150 nucleus reticularis and 122 ventral and posterior thalamic units. After medial forebrain bundle (MFB) or midbrain reticular (RET) stimulation, most nucleus reticularis units showed significantly decreased firing, and the MFB and RET effects converged on 64%. None was excited. In ventral and posterior thalamus, however, long‐lasting unit responses were mixed. MFB and RET stimuli elicited significantly increased firing in 17% and 20% of the units, respectively, and decreased firing in 21% and 16%, respectively. Convergence of MFB‐ and RET‐elicited responses occurred in 25% of the cells, but none showed convergence of opposite responses which might reflect believed motivational differences between the stimuli. Similar stimuli delivered to ventral medial thalamus evoked pronounced excitation of nucleus reticularis discharge, contrasting the MFB and RET effects and confirming previous reports by others. The substantial responses elicited by MFB and RET stimuli in nucleus reticularis fulfill previously proposed criteria for definition of an arousal dimension in terms of single cell activity. The similarity of MFB and RET effects in the posterior nucleus of thalamus raises questions regarding its role in nociception.
3‐methoxy‐4‐hydroxy‐phenylglycol sulfate (MOPEG‐SO4) in ventricular and cisternal cerebrospinal fluid of dogs
Authors: Bareggi Silvio R. , Stabenau James R. , Shaskan Edward G. , Becker Robert E. , Roberts Melville 
Published: January 2005

AbstractCerebrospinal fluid was collected from the lateral ventricles and cisternal space from beagle dogs under light pentobarbital anesthesia. Homovanillic acid (HVA), 5‐hydroxyindoleacetic acid (5‐HIAA), and 3‐methoxy‐4‐hydroxyphenylglyco‐sulfate (MOPEG‐SO4) level in the liquor taken from these two regions were evaluated, and the ventricular‐cisternal ratio (V/C) was calculated for each monoamine metabolite. A marked similarity in the V/C ratio of 6:1 for 5‐HIAA and 5:1 for MOPEG‐SO4, as compared to a much higher V/C ratio of 18:1 for HVA, perhaps reflects the more diffuse distribution of norepinephrine and serotonin, precursor amines, as compared to dopamine in the CNS and also emphasizes the probable existence of an active transport mechanism for the removal of MOPEG‐SO4, as has been well documented for 5–HIAA and HVA.
Biosynthesis of DNA and RNA in neuronal and glial cells from various regions of developing rat brain
Authors: Giuffrida A. M. , Hamberger A. , Serra I. 
Published: January 2005

AbstractSlices of cerebral hemispheres, brain stem, and cerebellum from rats 5–30 days old were used for in vitro incorporation of [methyl‐3 H] thymidine and [6‐14 C] orotic acid into DNA and RNA, respectively. The rates of DNA and RNA synthesis decreased markedly during development, with the most marked decrease observed for DNA. The different brain regions showed specific patterns of decline of DNA and RNA synthesis. Following incubation of slices, the tissues were fractionated to obtain fractions enriched in neuronal cells and in glial cells. In cerebellum, the granule neurons were separated from the Purkinje neurons. The glial: neuronal ratio of DNA specific activity was different in the three regions examined: in cortex it decreased from 6 at 10 days to 3 at 20–30 days; in brain stem it was 3 throughout 10–30 days; in the cerebellum (glia:granule neuron ratio) it was also 3 at 30 days but only 0.3 at 10 days. Concerning the RNA incorporation, small differences were found between neuronal and glial cells.
Effects of hippocampal and amygdalar stimulation on uptake and binding of 3H‐hydrocortisone in the hypothalamus of the cat
Authors: Stith Rex D. , Person Robert J. , Dana Richard C. 
Published: January 2005

AbstractStimulation of the hippocampus or amygdala of adrenalectomized cats occurred for 10 sec followed by a 50 sec period of no stimulation, beginning 30 min prior to and ending 30 min after administration of 100 μCi of 3H‐hydrocortisone into a lateral ventricle. Sixty min after administration of labeled hormone, the hypothalamus was excised and homogenized. Cytosol and nuclear extract fractions were obtained and analyzed for radioactivity and protein content. Separation of bound from free hydrocortisone was achieved by charcoal adsorption assay.Results reveal that stimulation of the hippocampus resulted in a greater concentration of 3H‐hydrocortisone taken up into hypothalamic cells. Also, a greater percentage of total hormone found in the nuclear extract was assayed as bound 3H‐hydrocortisone, and the concentration of bound radioactivity in the nuclear extract was increased over control values. Amygdalar stimulation, in general, yielded results similar to those obtained from control cats. However, although a lesser percentage of total hormone in the hypothalamic cytosol was assayed as bound hormone, there was a greater concentration of nuclear bound hormone than in controls, but less than that determined in the hippocampal stimulation group.These results add to the evidence that hippocampus and amygdala have a modulating influence upon the hypothalamo‐hypophyseal axis. They also suggest that one manner in which these limbic structures may influence hypothalamic function is to modulate the uptake and binding of hydrocortisone in hypothalamic cells.
Biochemical studies of taste sensation: II. Labeling of cyclic amp of bovine taste papillae in response to Sweet and bitter stimuli
Authors: Cagan Robert H. 
Published: January 2005

AbstractLabeling of cyclic AMP of taste papillae and its responsiveness to taste stimuli has been measured using whole papillae from bovine tongue prelabeled with [8‐14 C] adenine. Labeling was measured in circumvallate and fungiform papillae, both of which contain taste buds, and in filiform papillae and small blocks of tongue epithelium, which are devoid of taste buds. No differences were observed in the levels of activity.The labeling of cyclic AMP of circumvallate papillae showed only small increases (12–22%) in the presence of the taste stimulus sucrose (sweet), and the stimulatory effects were not statistically significant. The increase due to sucrose was not potentiated by theophylline. No stimulation by sucrose was observed with epithelium controls. Lactose, which is a poor taste stimulus, did not stimulate labeling of cyclic AMP in taste papillae. Theophylline, caffeine, and quinine (bitter) stimulated labeling of cyclic AMP by up to 2‐fold, as did L‐Epinephrine.Evidence for a specific role of cyclic AMP as a second messenger in taste sensation was not obtained. It is suggested that cyclic AMP might provide a mechanistic basis for studying some of the effects of sweet and bitter compounds in mixtures.
Effects of anesthesia level and stimulus characteristics on the amplitude and latency of the somatosensory evoked response in monkeys
Authors: Pimmel R. L. , Hung N. C. , Bresnahan J. C. , Hyman P. R. , Yashon D. 
Published: January 2005

AbstractThe effect on the somatosensory evoked response (SER) of the level of anesthesia, and the effect of the site, intensity, duration, and frequency of the stimulus on the amplitude and latency of various components of the SER were studied in 8 Rhesus monkeys. Peroneal nerve stimulation produced similar patterns over both sides of the head, with a slightly larger amplitude over the contralateral cortex. With ulnar nerve stimulation, significantly different patterns were observed over the contralateral and ipsilateral cortex; however, the former still had a slightly larger amplitude. The latency of the various components in the SERs was not influenced by the level of anesthesia or by the intensity, duration, or frequency of the stimulus. As the level of anesthesia decreased, there was a general increase in amplitude of the SERs with peroneal nerve stimulation and no consistent change with ulnar nerve stimulation. The amplitudes of the SER increased with an increase in stimulus intensity or duration, and with a decrease in stimulus frequency.
Response of a brain protein fraction 24 hours after training in rats
Authors: Hydéan Holger , Lange Paul W. 
Published: January 2005

AbstractThe aim of the study was to follow the amount and incorporation of 14C‐valine into separate, soluble protein fractions of the hippocampus, thalamus, and visual cortex of rats from 0 to 72 hr after training. The behavioral test consisted of reversal of handedness with training twice daily for 25 min for 2 days, followed by a 5‐day intermission without training, and a final session of 25 min. The animals were injected intraperitoneally with 14C‐valine 30 min before sacrifice and taken 0, 24, 48, and 72 hr after last training.After 24 hr, and only at that time, double incorporation values and increased amounts were observed in a protein fraction, No. 6 from the front, in all three brain areas of the trained rats compared to active controls. At 48 hr this protein fraction was at control level.
Endotoxin alters spontaneous transmitter release at the frog neuromuscular junction
Authors: Person Robert J. 
Published: January 2005

AbstractThe direct neurotoxic effects of E. coli endotoxin (ETX) on spontaneous transmitter release were tested at the frog sartorius muscle neuromuscular junction. Spontaneous transmitter release was monitored by intracellularly recording miniature end‐plate potentials (MEPPs). Junctions were continuously exposed to standard concentrations of 10μg/ml of 3 ETX sample, 2 of which produced a significant elevation of MEPP frequency followed by a decline of frequency to very low rates. The third ETX sample, known to have a decreased canine lethality, was with out effect on MEPP frequency. No significant changes in MEPP amplitude were evident. The rate of change in MEPP frequency, but not the peak frequency, was reduced by lowering ETX concentrations. Alterations in MEPP frequency induced by ETX were prevented by removing Ca++ and antagonized by high [k+] out. The results suggest that ETX alters ion conductance channels, particularly those for Ca++, in the presynaptic terminal membrane.
Binding of apomorphine to neural membranes
Authors: Hoss Wayne , Reese James H. , Smiley Constance 
Published: January 2005

AbstractThe intrinsic fluorescence of apomorphine has been used to measure its binding to neural membranes. A large number of relatively weak binding sites are concentrated in myelin and synaptic membrane fractions. Butyrophenones have the highest affinities for these sites – KD = 43 μM for haloperidol – while dopamine and dopamine releasers and reuptake blockers, as well as a variety of other alkaloids, have much lower affinities. The sites are hydrophobic and undergo a phase transition to a highly fluid state near 26°C. Calcium is a non‐competitive inhibitor of apomorphine binding. Some of the actions of neuroleptic drugs may result from binding to these hydrophobic membrane sites in vivo, blocking conduction in small catecholamine axons.