bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antidiarrhoeal activity of hot water extract of black tea (Camellia sinensis)
Authors: Besra S. E. , Gomes A. , Ganguly D. K. , Vedasiromoni J. R. 
Published: April 2003

AbstractThe effect of a hot water extract of black tea (Camellia sinensis (L.) O. Kuntze, Theaceae) on upper gastrointestinal transit and on diarrhoea was investigated employing conventional rodent models of diarrhoea. Black tea extract was found to possess antidiarrhoeal activity in all the models of diarrhoea used. Naloxone (0.5 mg/kg i.p.) signiﬁcantly inhibited the antidiarrhoeal activity of the extract as well as loperamide, thus indicating a role of the opioid system in the antidiarrhoeal activity of the extract. Copyright © 2003 John Wiley & Sons, Ltd.
A strategic framework for technical function management in manufacturing
Authors: Challis David , Samson Danny 
Published: April 2003

AbstractDriven by the enhanced technological sophistication of products and production processes, the requirement to improve manufacturing plant return on investment and the need to better manage scarce technical resources, more firms are focusing on the activities of their technical functions. As many firms achieve or approach “best practice” in their organisational arrangements and management of human resources, there is an increasing recognition of the opportunities to enhance competitiveness through improved management of technology and technical functions. There is also substantial evidence to suggest that the development of new technology is occurring much faster than is the development of new approaches with which to manage it. This paper develops a framework, “technical effort”, through which to view technical activity in the context of improved business and organisational performance. This framework differs from traditional practice by integrating three different perspectives: maximising the contribution of technical functions to business outcomes, developing a sustainable source of competitive advantage in the form of an order winning set of technical capabilities and creating the working environment through which these requirements may be energised. It serves as a useful tool for Operations Managers to improve the strategic value of their technical functions by focusing learning on the linkages between business competitiveness, technical function outcomes, technical capabilities and organisational best practices.
Phosphoglycerides and their acyl group composition in myelin and microsomes of rat spinal cord during development
Authors: Sun Grace Y. , deSousa Byron N. , Danopoulos Vicki , Horrocks Lloyd A. 
Published: April 2003

AbstractThe phosphoglycerides and their acyl group composition in myelin and microsomes isolated from rat spinal cords were examined at various stages of the postnatal developmental period. In the immature cord, diacyl‐GPC is the major phosphoglyceride in both microsomal and myelin fractions. The proportion of this phosphoglyceride decreased steadily with age during development and the decrease was marked by an increase in diacyl‐GPE in microsomes and ethanolamine plasmalogen in both fractions. Marked changes in acyl group composition were observed in the microsomes during development of spinal cord, whereas acyl groups of myelin showed less extensive changes. A considerable amount of monoenoic fatty acid is already present in the myelin of 7‐day‐old cord. Acyl groups of diacyl‐GPC in the microsomal fraction indicated a decrease in 16:0, 16:1,20:4(n−6) and an increase in 18:0, 18:1 and 20:1 with respect to development. On the other hand, microsomal diacyl‐GPE and alkenylacyl‐GPE indicated a decrease in 16:0, 18:0 and 20:4(n−6), but an increase in 18:1 and 20:1. An exception is the proportion of 22:6(n−3) which increased in diacyl‐GPE and decreased in alkenylacyl‐GPE during development. The lack of obvious acyl group changes in myelin phosphoglycerides after 7 days of age is in agreement with the results of deSousa & Horrocks (Devl Neurosci. 1, 114–120, 1979) that myelination in spinal cord took on an early course and reached the adult composition sooner than the cerebrum.
Activity of muscle cultures measured by 2‐deoxyglucose uptake
Authors: Shainberg Asher , Pearl Rivka 
Published: April 2003

AbstractGlucose consumption of skeletal muscle differentiated in vitro was studied under various experimental conditions by means of the [3H]deoxyglucose ([3H]DG) uptake technique. The results show that glucose uptake by skeletal muscle is a function of its activity; when the muscle is electrically stimulated to contract the uptake of [3H]DG is increased, and when spontaneous activity is inhibited, the uptake of [3H]DG is decreased. While electrical stimulation (ES) did not affect the uptake of 3‐O‐methyl‐glucose (3‐OMG), DG uptake was enhanced in spite of the presence of cycloheximide in electrically stimulated cultures, suggesting that muscle contraction probably activates the enzyme hexokinase. Thus our data show that the uptake of [3H]DG can be a tool for measuring muscle contraction.
Long‐chain acyl coenzyme A synthetase activity during the postnatal development of the mouse brain
Authors: Reddy T. Sanjeeva , Bazan Nicolas G. 
Published: April 2003

AbstractPalmitic, linoleic, arachidonic, and docosahexaenoic acids were used as substrates to study fatty acid activation in the mouse brain and liver during postnatal development. Long‐chain acyl coenzyme A synthetase showed peak activity during the period of rapid oligodendroglial proliferation and myelination. In brain, activation of linoleic and arachidonic acids was highest, followed by palmitic and docosahexaenoic acids. In liver, no appreciable change in enzyme activity was seen during the period of development studied. Palmitic and arachidonic acids showed the highest rate of activation, followed by docosahexaenoic acid. These ontogenic data suggest the presence of a single long‐chain acyl coenzyme A synthetase in brain.
A pharmacologic investigation of the ‘transport response’ in the white rat
Authors: Wilson Christopher , Cullen Ellen , Sendell Kelly 
Published: April 2003

AbstractIn a series of six experiments, the ability of specific neurotransmitter antagonists to alter the ‘transport response’ was investigated in 19‐day‐old rat pups. The serotonergic blocker, methysergide, and the cholinergic blocker, scopolamine, did not produce any consistent changes in the intensity of the response. Likewise, the opiate receptor blocker, naloxone, was without effect. Large, dose‐dependent decreases in transport response intensity were seen with administration of the beta‐noradrenergic receptor blocker, propranolol, and with administration of the dopaminergic blocker, haloperidol. The alphanoradrenergic receptor blocker, phentolamine, produced inconsistent changes in the response. These results indicate a central catecholaminergic involvement in the transport response.
A morphometric study of mouse trigeminal roots after unilateral destruction of vibrissae follicles at birth
Authors: Savy C. , Margules S. , Solari A. , Wehrle R. , Verley R. , Farkas‐Bargeton E. 
Published: April 2003

AbstractTrigeminal sensory roots were studied in neonatal mice. On the deafferented side, the surface area of the cross‐section through the sensory root is diminished by 31% and the number of myelinated fibers is reduced by 21%. but the proportion between myelinated and unmyelinated fibers remains unchanged. The distribution of axonal diameters, analysed in 7 dorso‐ventral scanning bands through the sensory roots, indicates a loss or eventually an atrophy of large myelinated axons in the medial two thirds of the sensory root. In both control and deafferented sides the diameter of the myelinated fiber (outside the myelin sheath) is proportional to the axon diameter (inside the myelin sheath). Our results confirm the loss of most of the neurons innervating vihrissae and the lack of regeneration or sprouting in the deafferented root in the newborn mouse.
Effect of activity on the selective stabilization of the motor innervation of fast muscle posterior latissimus dorsi from chick embryo
Authors: Bourgeois Jean‐Pierre , Toutant Madeleine , Gouzé Jean‐Luc , Chanceux Jean‐Pierre 
Published: April 2003

AbstractThe role of neuromuscular activity in the maturation of the motor innervation was investigated in the fast focally innervated posterior latissimus dorsi (PLD) muscle of the chick embryo. The axonal supply in the PLD motor nerve, and the focal multiple innervation of the endplates were described on days 15 and 16 of embryonic life in normal and experimental embryos. In the first series of experiments, chick embryos were paralyzed by repeated injections between days 4 and 10 in ovo of the curare‐like agent, flaxedil. Twice more axons in the PLD motor nerve and about twice more nerve terminal profiles at the endplates in the PLD muscles were found in paralyzed than in control embryos.In a second series of experiments, electrodes were implanted around the spinal cord of 7‐day‐old embryos and electric pulses delivered at 0.5 Hz frequency from day 10 to days 15–16 of incubation. At day 15.5, no change was observed in the axonal supply in the PLD motor nerve of stimulated embryos, while a two‐fold decrease was observed in the number of motor nerve terminal profiles per endplate in the corresponding PLD muscle.The statistical distribution of the number of motor nerve terminal profiles per endplate was described from complete semi‐serial sections in the PLD muscle from normal, paralyzed and stimulated chick embryos. In these three cases, the distribution of supernumerary nerve terminal profiles followed a Poisson law after one nerve ending had been subtracted from the number of nerve endings counted per endplate.
Experimental maternal hyperpipecolatemia decreases DNA in the mouse brain
Authors: Kim Jang Soo , Gutierrez Maria d.C. , Giacobini Ezio , Sundberg John P. 
Published: April 2003

AbstractPipecolic acid represents the major metabolite of lysine in the CNS. This study aimed to mimic the known pathological condition of hyperpipecolatemia in human neonates by maintaining high and steady concentrations in the mouse brain both pre‐ and postnatally. Although histological observations did not reveal any abnormal findings in the brain, liver and kidney, the offsprings of mothers which were injected during pregnancy with 250 mg/kg PA presented a significant decrease in both cortical and whole brain DNA content. Protein, RNA and CNPase activity were not altered. The changes in DNA content are of particular interest since they demonstrate that a high and steady level of pipecolic acid, which is comparable to the level seen in human hyperpipecolatemic brain, can induce a neurotoxic effect in the fetal mouse brain. Mice injected with the same dose from day 1 to day 29 after birth did not show any change in DNA content in the cortex. These results suggest that the critical period from pipecolic acid neurotoxic effect is prenatal, probably due to a selective vulnerability of developing neurons to high levels of pipecolic acid.The decrease in DNA concentration induced by maternal hyperpipecolatemia suggests a neurotoxic effect of pipecolic acid on cell proliferation during fetal development which could be related to the neuronal damage observed in the brain of hyperpipecolatemic neonates.
Development of taurine biosynthesizing system in cerebral cortical neurons in primary culture
Authors: Ohkuma S. , Tomono S. , Tanaka Y. , Kuriyama K. , Mukainaka T. 
Published: April 2003

AbstractDevelopmental patterns of taurine biosynthesizing system were investigated using primary cultured neurons prepared from the neopallium of 15‐day‐old fetal mice by a trypsin treatment in comparison with those in cerebral cortices obtained from age‐matched fetal and neonatal mice. The morphological observations by phase contrast and scanning electron micrographies indicated that the cells in primary culture used in the present study possessed typical features of neurons. In addition, the immunohistochemical studies using the antibody to glial fibrillary acidic protein (GFAP), a specific marker for astroglia, revealed that the contamination of astroglias was negligible. The contents of taurine and metabolic intermediates in taurine biosynthesis, cysteine sulfinic acid and cysteic acid, in primary cultured neurons showed decreases during their development, especially during the first week after the inoculation. Similar developmental patterns of these amino acids were observed in cerebral cortices in vivo during perinatal stage which corresponded to the first week of neuronal growth in vitro. On the other hand, the activities of cysteine sulfinic acid decarboxylase and cysteine dioxygenase, both of which are involved in the biosynthesis of taurine, were found to be increased progressively both in primary cultured neurons and in cerebral cortices in vivo during their growth. The immunohistochemical study using antitaurine antibody obtained from rabbit clearly demonstrated that immunoreactive materials were localized in cell bodies and the processes of neurons, and the intensity of the immunoreactivity in primary cultured neurons also showed a reduction with time of culture. These results indicate that primary cultured neurons used in this study possess a similar capacity to synthesize taurine from cysteine as developing brains in vivo. The present results also strongly suggest the well known decrease in cerebral taurine content in vivo during neonatal stages may be predominantly due to the decrease of taurine in neuronal cells.
Effects of light‐ and dark‐rearing on the postnatal development of GABA receptor sites in the chick optic lobe
Authors: Ríos Hugo , Flores Vladimir , de Plazas Sara Fiszer 
Published: April 2003

AbstractTo investigate the ability of GABA receptor sites to undergo environmental‐dependent plastic changes, the postnatal developmental pattern of GABA receptors was studied under different levels of light stimulation, i.e. normal‐, light‐ and dark‐rearing. At hatching the specific binding of (3H)GABA was 1.74 ± 0.36 pmol/optic lobe. In normally reared chicks the number of GABA binding sites showed a transient increase with the highest value at the 6th day (7.0 ± 1.32 pmol/optic lobe). This value is higher than the one reached at the adult stage. Between the 3rd and 6th day, there was a 33.7% increase in specific [3H]GABA binding in light‐reared compared with normally reared animals (P < 0.05). In the dark‐reared chicks, the specific binding was 36.4% lower than that found in normally reared (P < 0.02). However, the changes in receptor density were transient since at the 17th day the number of GABA binding sites returned to adult levels. Scatchard analysis revealed that the differences observed in the high affinity GABA binding sites between the three groups were due to modifications in the total number of binding sites while the affinity remained unchanged. The maximal number of binding sites were: 2.71, 7.01 and 1.79 pmol/mg protein in normally, light‐ and dark‐reared chicks, respectively; while the apparent dissociation constants were unaffected: 3.2, 3.4 and 3.6 nM, respectively. These results show that, during postnatal development, different conditions of visual experience produce synaptic changes at the molecular level. These changes probably occur within a period of high plasticity, prior to the end of a critical period.
Morphometric analysis of the cerebellar Purkinje cell in the developing normal and hypothyroid chick
Authors: Bouvet J. , Usson Y. , Legrand J. 
Published: April 2003

AbstractA morphometric analysis of Purkinje cells in the developing cerebellar cortex of the chick was performed in normal animals and embryos made hypothyroid by one or two spaced injections of tetramethylthiourea. Profiles of 162 Purkinje cells, from Golgi‐Cox treated sections were analysed. Soma area, perimeter and circularity index, cumulative length of the dendrites and number of dendritic bifurcations were studied. The results showed significant differences between control and hypothyroid animals. There were no important differences between birds rendered transiently hypothyroid with a single injection and those made chronically hypothyroid with dual injections. This confirms that the Purkinje cell is very dependent on thyroid hormone especially during the early phases of its morphogenesis. The development of the Purkinje cell was the most affected process of cerebellar cortex maturation in the thyroid‐deficient chick. The dendritic arborization was particularly hypoplastic. Moreover, a dynamic balance appeared to exist between the development of the dendritic arborization and that of the perikaryon.
l‐Aspartate and l‐glutamate binding sites in developing normal and ‘nervous’ mutant mouse cerebellum
Authors: Angelatou F. , Mitsacos A. , Goulas V. , Kouvelas E. D. 
Published: April 2003

AbstractThis study concerns the ontogeny and the cellular localization of l‐aspartate and l‐glutamate binding sites in normal and ‘nervous’ mutant mouse cerebellar membranes. The binding kinetics revealed for l‐aspartate a single binding system (Kd = 750 nM) and for l‐glutamate also a single binding component of higher affinity (Kd = 344 nM). The pharmacological study, using various amino acid analogues, revealed a differential specificity for the binding sites of the two amino acids.The developmental study showed that the binding sites of both amino acids appear mainly during the second and third week of life, a period when parallel and climbing fiber synaptogenesis occurs, but they follow a slightly different developmental pattern. The study using ‘nervous’, mutant mouse cerebellum showed an age‐dependent decrease of l‐aspartate and l‐glutamate binding, which coincides in time with the Purkinje cell degeneration in this mutant, indicating a cellular localization of these binding sites on the Purkinje cell membranes. These results suggest that l‐aspartate and l‐glutamate binding sites may be respectively associated with the postsynaptic target of climbing and parallel fibers on the Purkinje cell dendrites. However, the decrease of specific binding in ‘nervous’ mutant mouse cerebellum was about 50% for l‐aspartate and 60% for l‐glutamate, implying that a significant number of l‐aspartate and l‐glutamate binding sites are located on cerebellar elements other than the Purkinje cell membranes.
Induction of cytoskeletal alterations in C6 glioma by glia maturation factor
Authors: Ryken Timothy C. , Turner J. Wesley , Hicklin Danny J. , Miller Joyce F. , Baggenstoss Bruce A. , Lim Ramon 
Published: April 2003

AbstractC6 rat glioma cells respond to glia maturation factor (GMF) with characteristic morphological alterations. Observed under phase‐contrast microscopy, the cells changed from a rounded morphology in random formation to a spindle‐shaped appearance in parallel arrays. Observed under scanning electron microscopy, GMF led to a decrease in the number of microvilli and cell surface knobs. Transmission electron microscopy demonstrated the appearance of numerous microtubules aligned with the long axis of the cells after GMF stimulation. The change in cell shape and histotypic pattern was inhibited by vinblastin, further implicating the involvement of microtubules. Immunofluorescence using anti‐α‐tubulin revealed a well‐defined cytoskeletal system in GMF‐stimulated cells but not in the control cells. Finally, an increase in tubulin was confirmed with enzyme‐linked immunosorbent assay (ELISA) on extracts from these cultures. The findings indicate that morphological alterations induced by GMF are associated with changes in the quantity and arrangement of microtubules.
Influences of pertussis toxin, guanine nucleotides and forskolin on adenylate cyclase in striatal membranes of infant, adult and senescent rats
Authors: Nomura Yasuyuki , Arima Takashi , Swgawa Tomio 
Published: April 2003

AbstractTo identify age‐related changes in the dopamine (DA) receptors‐GTP‐binding protein‐adenylate cyclase system, the following experiments were performed at 7 days (infant), 70 days (adult) and 2 years (senescent) in striatal membranes of rats: (1) effects of GTP in the presence and absence of pertussis toxin (islet‐activating protein, IAP) on adenylate cyclase in the presence of forskolin alone, (2) the same in the presence of forskolin plus DA and (3) the corresponding effect of guanyl‐5′‐yl‐β, α‐imido‐diphosphate (GppNHp). GTP caused biphasic effects: the activation at 1 μM and the inhibition at 100 μM on forskolin‐stimulated cyclase activity at 70 days. The inhibition was suppressed with IAP pretreatment. In infant membranes, 100 μM GTP inhibited the activity in the absence and presence of 100 μM DA and IAP induced a reversal from the inhibition to the stimulation only in the presence of DA. In senescent animals, neither GTP nor IAP affected the activity. GppNHp at 1, 10 and 100 μM only activated and did not inhibit forskolin‐stimulated cyclase at each stage. GppNHp‐caused stimulation was no more affected by IAP. IAP ADP‐ribosylated 41,000 dalton proteins at each stage and the specific activity of ADP‐ribosylation was not changed during development and aging. It is suggested that inhibitory GTP‐binding protein (Gi) with molecular size of 41,0000 dalton is involved in DA receptor‐adenylate cyclase system whose function is low at infant stage and markedly decreased at senescent stage in rat striatal membranes.
Do catecholamines contribute to the effects of neonatal hypoxia on development of brain and heart? Influence of concurrent α‐adrenergic blockade on ornithine decarboxylase activity
Authors: Slotkin Theodore A. , Orband‐Miller Lisa , Queen Kennedy L. 
Published: April 2003

AbstractHypoxia in the neonate releases catecholamines from the adrenal medulla, a response which is necessary to survive. This study examines whether a similar dependence exists for the ability of brain and heart tissue to recover from hypoxia‐induced damage, as assessed by measurements of ornithine decarboxylase (ODC) activity. Hypoxia at either 1 day or 8 days of age produced a subsequent elevation of brain ODC which persisted for 1 week, a pattern known to be associated with recovery from tissue damage and delayed cellular maturation. Pretreatment of the rats with phenoxybenzamine, an α‐receptor blocking agent, resulted in attenuation of the long‐term ODC response, but did not interfere with effects on the enzyme during the hypoxia itself. In the heart, hypoxia at 8 days of age displayed similar effects, with long‐term ODC elevations which were attenuated by phenoxybenzamine. Hypoxia at 1 day of age also produced long‐term heart ODC stimulation, but in this case the effect was exacerbated by phenoxybenzamine, an effect consistent with the greater dependence of cardiac tissue on α‐receptor‐mediated responses to hypoxia at that age. These results suggest that α‐receptor stimulation by catecholamines released during neonatal hypoxia play a role in the metabolic adjustment of brain and heart tissue to damage and may aid in subsequent recovery.
Immunohistochemical localization of l‐Ornithine decarboxylase in developing rat brain
Authors: Dorn A. , Müller M. , Bernstein H.‐G. , Pajunen A. , Järvinen M. 
Published: April 2003

Abstractl‐Ornithine decarboxylase, the rate limiting enzyme of polyamine biosynthesis and a marker enzyme of tissue proliferation and maturation, was localized immunocytochemically in the developing rat central nervous system. It can be noted that the distribution of the enzyme protein underlies temporal alterations. Conclusions are drawn from the location of the enzyme and possible functional roles played by ornithine decarboxylase in discrete brain areas.