bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pattern of descending excitation of presumed propriospinal neurones at the onset of voluntary movement in humans
Authors: MAZEVET D. , PIERROT‐DESEILLIGNY E. 
Published: December 2008

Mazevet, D. & Pierrot‐Deseilligny, E. 1994. Pattern of descending excitation of presumed propriospinal neurones at the onset of voluntary movement in humans. Acta Physiol Scand150, 27–38. Received 2 April 1993, accepted 30 July 1993. ISSN 0001–6772. Neurophysiologie Clinique, Rééducation, Hôpital de la Salpêtrière, 47 boulevard de ľ Hôpital, 75651 Paris cedex 13, France.The pattern of activation of presumed ‘propriospinal’ neurones was investigated in human subjects during phasic voluntary contractions of one of the following muscles: biceps, triceps, flexor carpi radialis (FCR), flexor carpi ulnaris (FCU) and extensor carpi radialis (ECR). Changes in the amplitude of the H reflex (FCR, ECR), or the tendon jerk (biceps, triceps) were used to assess the excitability of the corresponding motorneurone pools after conditioning stimulation. Conditioning stimuli were applied to the musculo‐cutaneous, triceps and ulnar nerves. In most cases reflex facilitation was not observed at rest and was only disclosed at the onset of contraction. The characteristics of this facilitation (3–4 ms central delay, short duration, low threshold, depression when the afferent input was increased) are consistent with those previously attributed to ‘propriospinal’ excitation. It is argued that the contraction‐associated facilitation was descending in origin. The descending facilitation of the ‘propriospinal’ system had a characteristic pattern in that the pathways selected by higher centres were those receiving the afferent feedback from the contracting muscle. These results provide further insight into the organization of human ‘propriospinal’ pathways: (1) it is confirmed that afferents from each muscle activate a specific subset of neurones; and (2) it is suggested that the projections of each subset are divergent, implying that individual neurones project onto diverse motor nuclei, an organization that would favour the coordination of multi‐joint movements. Such an organization is discussed in relation to the possible role of the propriospinal system in the control of normal human upper limb movements.
Adrenergic, cholinergic and VIP‐ergic influence on gastric phasic motility in the rat
Authors: BOJÖ L. , CASSUTO J. , NELLGÅRD P. , JÖNSSON A. 
Published: December 2008

Bojö, L., Cassuto, J., Nellgård, P. & Jönsson, A. 1994. Adrenergic, cholinergic and VIP‐ergic influence on gastric phasic motility in the rat. Acta Physiol Scand 150, 67–73. Received 30 December 1992, accepted 23 July 1993. ISSN 0001–6772. Department of Clinical Physiology, Central Hospital Karlstad, Department of Physiology, University of Goteborg and Department of Anaesthesiology, Central Hospital, Molndal, Sweden.We investigated the effects of adrenergic, cholinergic and vasoactive intestinal polypeptide (VlP)‐ergic agonists and antagonists on the amplitude of gastric phasic contractions in the anaesthetized rat using a volumetric model. The amplitude of the phasic contractions was reduced significantly by atropine, hexamethonium or bilateral cervical vagotomy indicating that cholinergic neural activity involving both muscarinic and nicotinic receptors and intact vagal nerve function are integral parts of the control of basal gastric phasic motility. In contrast, neither selective α1‐, α2‐ or non‐selective β‐blockers had any significant influence on the amplitude of the gastric contractions suggesting that adrenergic neurones are not tonically active in the maintenance of basal phasic motility in the stomach. The amplitude of the gastric phasic contractions was, however, significantly reduced by the α1‐agonist L‐phenylephrine, the α2‐agonist clonidine and a close intraarterial injection of VIP (3 μkg‐1) but not be the selective β1‐agonist, prenalterol, or the β2‐agonist, salbutamol. These data suggest the presence of superimposed inhibitory control of phasic activity by VIP‐ergic stimulation and by adrenergic neurones via α‐receptor stimulation.
Recombinant human insulin‐like growth factor 1 (rh‐IGF‐1) stimulates erythropoiesis in adult, but not in newborn mice
Authors: BECHENSTEEN A. G. , HALVORSEN S. , SKOTTNER A. 
Published: December 2008

The in vivo effect of recombinant human insulin‐like growth factor (rh‐IGF‐1) upon erythropoiesis was studied in inbred BALB/C mice. Unweaned, rapidly growing 20 days old mice and adult female mice received subcutaneous rh‐IGF‐1 or control injections every 6 h for 48 h. The mice were killed either 12 or 48 h after the last injection, i.e. a study time of 60 and 96 h, respectively. Bone marrow erythroid colony forming units (CFU‐E), reticulocytes, haematocrit, serum immunoreactive erythropoietin (siEPO) and body and organ weight were measured. An additional group of young mice were given iron prior to the rh‐IGF‐1 injections to ensure sufficient available iron.No differences in overall body or organ weights were observed. In the young mice erythropoiesis as measured by bone marrow CFU‐E, reticulocytes and haematocrit did not differ between rh‐IGF‐1 group and controls. When iron alone was given, reticulocytes (P < 0.05) and haematocrit (P < 0.0001) increased significantly, but no further stimulation was seen when rh‐IGF‐1 injections were given in addition to iron. The adult female mice responded with significantly increased erythropoiesis as judged by increased reticulocyte counts following rh‐IGF‐1 injections (P < 0.001). No significant effect upon CFU‐E and haematocrit was detected. The reticulocyte response was more pronounced at 96 than at 60 h after the first rh‐IGF‐1 injection. SiEPO was significantly (P < 0.01) lower in the adult 96 h rh‐IGF‐1 group than in the appropriate control group.In conclusion parenteral iron significantly increased haematocrit in unweaned mice. Short time rh‐IGF‐1 treatment did not stimulate erythropoiesis in these rapidly growing mice, whether or not iron supplementation had been given. In the adult mice, short time rh‐IGF‐1 treatment stimulated in vivo erythropoiesis as shown by a reticulocyte response. Since the siEPO levels dropped in the adult treatment group the increase in reticulocytes suggests a directly stimulatory action of rh‐IGF‐1 upon erythropoiesis.
Skin sympathetic nerve activity and effector function during sleep in humans
Authors: NOLL G. , ELAM M. , KUNIMOTO M. , KARLSSON T. , WALLIN B. G. 
Published: December 2008

Multi‐unit sympathetic skin nerve activity (SSA) in the peroneal nerve was recorded together with electrical skin resistance, skin blood flow and (in some subjects) finger blood pressure during sleep in 22 sleep‐deprived healthy subjects. The average strength of sympathetic activity in different sleep stages was measured during 5‐min periods as the area‐under‐curve of the integrated neurogram. Stage 2 sleep was reached by 15 subjects, stages 3–4 by nine and rapid eye movement (REM) sleep by six subjects. Non‐REM sleep was always associated with an increased skin resistance, which was larger in glabrous than in hairy skin (293±48 vs. 175±4% of awake control level, n= 10, P < 0.05). Skin blood flow also increased during sleep, with a mean maximal increase of 397±79% of the awake control level (n= 11, P < 0.05). In spite of these changes of effector function no significant difference in mean SSA was found between the awake control period and periods of non‐REM sleep, but during REM sleep SSA increased with 34% (P < 0.05) compared with the immediately preceding stage 2 period. In stage 2 sleep, K‐complexes were associated with bursts of SSA followed by transient changes of skin resistance, blood flow and arterial blood pressure. When both skin resistance and blood flow were recorded within the innervation area of the impaled fascicle, single bursts or short periods of increased SSA could be succeeded by increased skin blood flow without concomitant skin resistance change. This indicates the existence of specific sympathetic vasodilator fibres in the skin.Therefore the unchanged strength of multiunit SSA during non‐REM sleep in the face of increases of skin resistance and blood flow may be a consequence of an increased sympathetic vasodilator nerve activity combined with decreases of vasoconstrictor and sudomotor traffic.
Carbachol‐induced phosphatidylcholine hydrolysis and choline efflux in rat submandibular gland involves phospholipase D activation and is modulated by protein kinase C and calcium
Authors: DUNÉR‐ENGSTRÖM M. , FREDHOLM B. B. 
Published: December 2008

The role of calcium and protein kinase C activation in carbachol‐induced choline efflux from submandibular glands was investigated. The participation of phospholipase D in this signal transduction pathway was demonstrated by the formation of [14C]phospha‐tidylethanol in [14C]lysophosphatidylcholine‐labelled submandibular gland cells treated with carbachol or noradrenaline in the presence of ethanol. Chelation of the intracellular calcium with BAPTA/AM reduced the carbachol stimulated outflow of [3H]choline.* The calcium ionophore A23187 in a high concentration (10 μm) increased the basal [3H]choline outflow, but decreased the carbachol‐induced outflow. Removal of the extracellular calcium enhanced the carbachol‐stimulated outflow, which returned to control when calcium was re‐added to the medium.Activation of protein kinase C by phorbol‐12,13‐dibutyrate (100 nM) or l‐oleyI‐2‐acetyl‐sn‐glycerol (20 μM) was without effectper se, but enhanced the carbachol‐mediated outflow of [3H]choline. Phorbol‐12,13‐dibutyrate in combination with 1//M A23187 induced a small efflux of [3H]choline. A 2h treatment with phorbol‐12,13‐dibutyrate (1 μM), causing down‐regulation of protein kinase C, significantly decreased the carbachol‐stimulated [3H]choline outflow.In conclusion, elevation of intracellular calcium levels and protein kinase C activation are of importance for the carbachol‐stimulated outflow of [3H]choline. Inflow of calcium, if anything, reduces the carbachol‐stimulated outflow of [3H]choline. Since phosphatidylcholine breakdown generates diacylglycerol and this could lead to activation of protein kinase C, activation of this signal transduction pathway may be important for the protein content of the saliva and for the known trophic effects of parasympathetic innervation.
Glomerular filtration and tubular absorption of the basic polypeptide aprotinin
Authors: TENSTAD O. , WILLIAMSON H. E. , CLAUSEN G. , ØIEN A. H. , AUKLAND K. 
Published: December 2008

The basic polypeptide aprotinin (Ap), mol. wt 6500, pi 10.5, is filtered in the glomeruli, virtually completely taken up by the proximal tubular cells and retained there for many hours. This process was studied in rats by determining the renal plasma clearance (CAp) as the amount of [126I]Ap accumulated in the kidney plus that excreted in the urine per unit of time divided by the integrated plasma concentration. In periods lasting 4–20 min after i.v. bolus injection or infusion to constant plasma concentration, CAp was 65% of glomerular filtration rate (GFR) estimated as kidney plus urinary clearance of [51Cr]EDTA (CCr.EDTA). Less than 0.8% of the filtered Ap appeared in the urine. CAp varied inversely with plasma protein concentration in mgml“1: CAp/CCrEDTA= 0.98‐0.0058 × PPr, corresponding to a glomerular Gibbs‐Donnan distribution for a net molecular charge of + 6, in agreement with the amino acid composition of Ap. CAp (kidney + urinary) was not altered by inhibiting tubular uptake of [125I]Ap by maleate or by exceeding the uptake capacity with large doses of unlabelled Ap. Neutralized Ap (malonylated) did not accumulate in the kidney, but showed a urinary clearance indistinguishable from that of [51Cr]EDTA. Both CAp and C(.rEDTA were reduced to 0.04 ml min‐1 when glomerular filtration pressure was lowered by ureteral stasis and increased PPr (80–90 mg ml”1). These findings indicate: (1) no steric or charge restriction to filtration of Ap in the glomerular membrane, (2) the Gibbs‐Donnan equilibrium should be considered when estimating glomerular sieving of charged polypeptides in intact animals (3) charge dependent tubular uptake, (4) little or no transtubular transport of intact Ap, (5) no appreciable tubular uptake of Ap from the peritubular side and (6) local renal accumulation of Ap in a period of up to 20 min may be used to estimate local glomerular filtration and/or local proximal tubular reabsorption rates.Model analysis based on the appearance of 125I in plasma, the time course of renal Ap content, and literature data on subcellular Ap distribution are consistent with two populations of endosomes, transporting Ap at widely different rates from the proximal tubular brush border to the lysosomes where breakdown occurs at a high rate.
Excitability of the soleus H reflex during graded walking in humans
Authors: SIMONSEN E. B. , DYHRE‐POULSEN P. , VOIGT M. 
Published: December 2008

The excitability of the soleus Hoffmann (H) reflex was measured in five healthy male subjects during graded treadmill walking. Uphill and downhill walking at an 8% grade as well as level walking were used to vary the demands for lengthening and shortening contractions of the soleus muscle. These changes were assumed to cause differences in control of the afferent input in the spinal cord and the voluntary output to the soleus muscle.The H reflex was strongly modulated in all three walking conditions, high during the stance phase and low or absent during the swing phase. The shape of the modulations was, however, different. At uphill walking the reflex increased gradually during the whole stance phase and seemed to follow the soleus electromyogram (EMG) pattern closely. In the downhill condition the reflex excitability increased rapidly at heel strike like the soleus EMG and co‐contraction of the anterior tibial muscle was observed. At level walking a fast rise in reflex excitability was seen just after heel strike with low or absent soleus EMG.Mean soleus EMG was lower during downhill than during uphill or level walking, but the mean H reflex amplitude was similar in all three conditions. However, when the H reflex was related directly to the EMG activity by linear regression the reflex gain was lower during uphill walking than in the two other conditions. Furthermore, the ratio between H reflex and EMG amplitude was high during the first half of the stance phase at level walking indicating an elevated reflex excitability independent of the voluntary motor output. It is therefore concluded that the modulation of reflexes during walking cannot be interpreted in terms of the idea of automatic gain compensation. The reflexes must be controlled specifically and independently during the different phases of the motor output to meet the mechanical requirements of the movement task. Most explicitly this was seen during downhill walking, where an elevated reflex excitability together with co‐contraction at the ankle joint seem to provide increased joint stiffness and security, when the kinetic energy of the body has to be brought under control at heel strike.
Vasoactive intestinal peptide regulates angiotensin II catabolism in the rabbit
Authors: DAVIS R. E. , YE V. Z. C. , MACDONALD G. J. , DUGGAN K. A. 
Published: December 2008

Although vasoactive intestinal peptide (VIP) is natriuretic it stimulates renin and aldosterone secretion. Therefore, to effect a natriuresis, VIP may need to modulate the sodium conserving actions of the renin angiotensin system (RAS) by another means. One possibility is that it alters the rate of disappearance from the circulation of one or more components of the RAS. We sought to determine whether VIP regulates the rate of catabolism of angiotensin II (Ang II). Steady state metabolic clearance studies of Ang II were undertaken with and without simultaneous VIP infusion. These studies were performed in rabbits on low, normal and high sodium diets, as dietary sodium has been shown to affect the metabolism of both VIP and Ang 11. The effects of VIP on plasma Ang 11 concentration and secretion were also studied. VIP decreased Ang II catabolism in rabbits on low (P < 0.05) and normal sodium diets (P < 0.05). Plasma levels of Ang II increased significantly in response to VIP in rabbits on these diets (low, P < 0.04; normal, P < 0.05). In contrast, in rabbits on a high sodium diet VIP increased the rate of catabolism of Ang II (P < 0.001).Thus we conclude that the effect of VIP on sodium excretion may be modulated by its effects on Ang II metabolism. The decrease in Ang II catabolism seen in rabbit on low and normal sodium diets may prevent or ameliorate any natriuresis while the more rapid degradation of Ang II which occurs in dietary sodium excess may enhance the natriuretic effect of VIP.
Validation of the ‘internal reference technique’ for calibrating microdialysis catheters in situ
Authors: LÖNNROTH P. , STRINDBERG L. 
Published: December 2008

In vivo calibration of microdialysis catheters with [3H]glucose as internal reference was done in rat (n= 17) and human (n= 12) subcutaneous tissue. The estimated interstititial glucose level was compared owth the glucose concentration in venous plasma which, in turn, has been shown to be identical to the interstitial glucose concentration. In subcutaneous tissue of anaesthetized male Sprageue‐Dawley rats, interstitial glucose was significantly overestimated (43%, P < 0.005, n= 8, and 19%, P < 0.005, n=9, in nornoglycaemic and hyperglycaemic animals, respectively). Furthermore, fractional outflux of [3H]glucose decreased continuously during prolonged perfusion of the microdialysis catheter. Incontrast, in human subcutaneous tissue microdialysed with two catheters, correct measurements of interstitial glucose could be achieved and the precision was comparableto that obtained with equilibration calibraton in vivo. The average relative error of the mean result of two catheters was 8.9% at a perfusate flow rate of 1 μL min‐1.It may be suggested that calibration in in vivo of microdialysis catheters with internal references may be used in human subcutaneous tissue. However, it is necessary to validate the calibration technique in each different tissue under reproducible experimental conditions since accumulation of the reference substance in the tissue may create artefactual results.
Larvicidal potentials of leaf and bark extracts of Eucalyptus camaldulensis (Schlect) and Eucalyptus citriodora (Hook) on Culex quinquefasciatus (Say) larvae
Authors: IDRIS H. S. , LAWAL S. B. , BALARABE B. M. 
Published: December 2008

AbstractThe larvicidal activity of leaf and bark extracts of Eucalyptus camaldulensis and Eucalyptus citriodora on juveniles of Culex quinquefasciatus was determined. Larvae were successfully bred in the laboratory to obtain a “pure” colony. One hundred and sixty‐two batches of 25 larvae each were treated with 3.90, 15.63, 62.50, 250 and 1000 mg/L of plant extract in three replicates, for 24 h to record mortality and for up to 96 h to record feeding and fecundity. There was an increase in percentage mortality with increase in concentration of the petroleum ether plant extracts. There was a statistically significant difference (P < 0.05) between extracts used in the bioassay and mortality of larvae, but there was no significant difference (P > 0.05) between the two plant species. Statistical analysis of average mortality figures using Probit analysis for the leaf extracts of E. citriodora and E. camaldulensis, respectively, had LC50 of 245.47 (26.89 ± 10.13 [SE]) and 316.23 (22.89 ± 8.95) for the crude extracts; 97.72 (44.95 ± 12.89) and 223.87 (29.17 ± 9.56) for the petroleum ether extracts; and 162.18 (30.7 ± 11.16) and 257.04 (26.47 ± 9.28) for the methanol extracts. The bark extracts of E. citriodora and E. camaldulensis, respectively, had LC50 of 251.19 (27.78 ± 8.39) and 398.11 (20.7 ± 7.17) for methanol; and 302.0 (21.56 ± 8.11) and 630.96 (13.56 ± 6.4) for hexane. Both plant species showed anti‐feeding properties against larvae of Culex quinquefasciatus.
Reproductive responses to photoperiod and temperature by artificially hibernated bumblebee (Bombus terrestris) queens
Authors: AMIN Md. Ruhul , SUH Sang Jae , KWON Yong Jung 
Published: December 2008

AbstractPost‐hibernated bumblebee (Bombus terrestris) queens were kept for 1 week under photoperiodic conditions of 8 h light : 16 h dark, and at four different temperatures (24, 28, 32 and 36°C). The reproductive performance of the queens was then observed. It was found that exposure temperature and hibernation duration did not affect the oviposition rate. The pre‐oviposition period was found to be shortest (3.8 ± 0.7 days) for queens that had hibernated for 4.0 months and had been activated at 28°C. Timing of the initiation of the switch‐point was not affected by exposure temperature and hibernation duration. Significantly higher numbers of workers (268.0 ± 31.4) and sexual queens (119.3 ± 16.8) were produced by the queens that had hibernated for 3.0 months and had been activated at 28 and 36°C, respectively. The queens that had hibernated for 4.0 months and had been activated at 36°C produced the highest number of males (296.2 ± 32.3).
Correlation between population dynamics of mosquito larvae and their habitat qualities
Authors: RANJEETA Lalit Mohan , SHARMA Preeti , SRIVASTAVA C. N. 
Published: December 2008

AbstractSurveillance of anopheline and culicine larvae was conducted fortnightly to determine population composition and density at seven sites in the area of the Mathura Refinery, Mathura, India during 2005–2006. The correlation between population of the vectors and their habitat quality was established. Temperature (0.978 and 0.85°C), pH (0.99 and 0.95), conductivity (0.98 and 0.98 mho) and calcium ion hardness (0.978 and 0.85 p.p.m.) were positively correlated with the populations of both larval species. In contrast, the correlation coefficients between the parameters total hardness, magnesium ion hardness, biochemical oxygen demand and chemical oxygen demand varied with the larval species. The anopheline larval population was dominant over the culicine population in the surveillance area. The distribution of anopheline mosquito larvae during the study period was found to be constant, and the average density of anopheline and culicine larvae was 84.70 and 15.30%, respectively, across all seven sites. Thus, the study demonstrated spatial and temporal population differences of mosquito larvae with respect to environmental factors, including water quality.
Evaluation of damage caused by stalk borers, Sesamia spp. (Lepidoptera: Noctuidae), on sugarcane quality in Iran
Authors: ASKARIANZADEH Alireza , MOHARRAMIPOUR Saeed , KAMALI Karim , FATHIPOUR Yaghub 
Published: December 2008

AbstractThe noctuid stalk borers, Sesamia spp. (S. cretica Led. and S. nonagrioides Lef.), damage a considerable percentage of sugarcane internodes annually in the province of Khuzestan, Iran. A study was conducted to quantify the relationship between stalk borer damage and sugar quality to estimate the monetary loss incurred at these levels of damage at harvest time. Three commercial varieties of sugarcane (SP70‐1143, CP69‐1062 and CP48‐103) were studied to determine the effects of damage on sugar quality. Stalks were separated into seven groups: control (without damage); one to five bored internodes per stalk; and more than five bored internodes per stalk. The percentage of bored internodes and several parameters, such as pol and brix, were measured. Sugar in the control group was 123.78, 123.72 and 104.84 kg/ton for SP70‐1143, CP69‐1062 and CP48‐103, respectively. Sugar per ton, juice purity, pol and brix were all significantly inversely correlated to the percentage of bored internodes. Estimated sugar losses for every 1% bored internode were 0.17, 0.39 and 0.23% (equal to 210, 482 and 241 kg sugar) in SP70‐1143, CP69‐1062 and CP48–103, respectively. These varieties could tolerate damage of up to 18.1, 11.7 and 18.9% bored internodes, respectively, compared to the control. Regression slopes for CP69‐1062 were slightly higher than those of the other two varieties. Therefore, based on quality damage, CP69‐1062 is susceptible to stalk borer damage.