bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE MECHANISM OF α‐ADRENERGIC INHIBITION OF CATECHOLAMINE RELEASE
Authors: COHEN JACKIE , ECKSTEIN LEAH , GUTMAN YEHUDA 
Published: May 2015

The effect of α‐adrenoceptor agonists on membrane adenosine triphosphatase (ATPase) activity was studied in membranes from the bovine adrenal medulla and the rat submaxillary gland.
α‐Adrenoceptor agonists (10−7 to 10−5 m) enhanced significantly Na,K‐ATPase activity but not Mg‐ATPase activity in adrenal medulla. This effect was not observed in membranes from phaeochromocytoma. Phenylephrine (10−5 m), naphazoline (10−5 m) and clonidine (10−5 m) caused a significant increase of the activity of Na,K‐ATPase (but not of Mg‐ATPase) in the submaxillary gland. The enhancement became more prominent after ligature of the submaxillary duct but disappeared completely after superior cervical ganglionectomy. Thus, the effect of the α‐adrenoceptor agonists was due to an action on adrenergic nerve terminals in the submaxillary gland.
Phenylephrine and naphazoline did not affect 45Ca uptake but enhanced the rate of 45Ca efflux from adrenal medullary slices in vitro.
Phenylephrine enhanced the rate of 45Ca efflux from slices of submaxillary gland (with previous ligation of the duct); this was blocked by phentolamine and sympathetic denervation. Therefore phenylephrine was acting on the adrenergic nerve terminals.
It is suggested that the inhibition by α‐adrenoceptor agonists of the exocytotic release of catecholamines from adrenergic nerve terminals and from chromaffin cells may be due to activation of the sodium pump, which results in enhancement of calcium efflux, causing a reduction of free intracellular Ca2+.
INHIBITION OF NEUROEFFECTOR TRANSMISSION BY MORPHINE IN THE VAS DEFERENS OF NAIVE AND MORPHINE‐TREATED MICE
Authors: ILLES P. , SCHULZ R. 
Published: May 2015

The amplitude of excitatory junction potentials (e.j.ps) recorded intracellularly from smooth muscle cells of the mouse vas deferens varied with the strength of stimulation. Normorphine (0.4, 2 and 10 μm) shifted the stimulus‐response curve to the right, without any change in slope. This shift of the curve was proportional to the concentration of the opiate in the bath. Naloxone (0.4 and 2 μm) antagonized this effect of normorphine.
The action of normorphine (2 and 10 μm) was studied in vasa deferentia prepared from control mice and mice that had been implanted with morphine pellets. Both groups of tissues were continuously exposed to a low concentration of normorphine (0.4 μm), to simulate the plasma concentration in the morphine‐treated mice. Addition of 10 μm normorphine produced a parallel displacement of the curve in vasa deferentia from control animals, and a non‐parallel displacement in tissues from morphine pellet‐implanted mice. In the preparations from morphine‐treated mice a pronounced degree of tolerance to normorphine was observed at a low stimulus strength.
Naloxone (0.4 and 2 μm) had a greater effect on vasa deferentia prepared from morphine‐treated animals than on tissues from control mice, when both organs were continuously exposed to 0.4 μm normorphine. The difference in the effect of the antagonist in the two groups of preparations was absent when the incubating solution contained 2 μm normorphine.
It is concluded that at a low intensity of stimulation the e.j.ps are more readily depressed by normorphine and also the degree of tolerance displayed is larger than at a high intensity of stimulation.
THE EFFECTS OF CALCIUM CONCENTRATION ON THE INHIBITION OF CHOLINERGIC NEUROTRANSMISSION IN THE MYENTERIC PLEXUS OF GUINEA‐PIG ILEUM BY ADENINE NUCLEOTIDES
Authors: DOWDLE E.B. , MASKE R. 
Published: May 2015

Adenosine and the adenine nucleotides AMP, ADP, ATP, cyclic AMP, NAD, NADP and NADH produced a dose‐related inhibition of the contractile response of guinea‐pig ileum longitudinal muscle‐myenteric plexus strips to low frequencies (< 1 Hz) of electrical field stimulation.
These compounds inhibited hexamethonium‐sensitive contractions induced by nicotine but did not alter the responses to exogenous acetylcholine, and the acetylcholine output from the myenteric plexus was inhibited by the adenyl compounds. These findings indicate that adenine derivatives act at a presynaptic site on postganglionic cholinergic neurones.
The degree of inhibition produced by adenine compounds was inversely related to the calcium concentration of the bath fluid over a range of calcium concentrations (1 to 5 mm) that had no effect on the responses of the muscle to exogenous acetylcholine.
The inhibition produced by adenine derivatives was antagonized by theophylline and augmented by dipyridamole. Both of these interactions were sensitive to, and synergistic with, alterations of the concentration of calcium in the bath fluid.
The results suggest that adenine compounds inhibit acetylcholine release from the myenteric plexus by diminishing the availability of intracellular calcium ions required for neurotransmitter release.
UPTAKE OF RADIOCALCIUM BY NERVE ENDINGS ISOLATED FROM RAT BRAIN: KINETIC STUDIES
Authors: GRIPENBERG J. , HEINONEN E. , JANSSON S.‐E. , Heinonen E. , Tolppanen E. M. 
Published: May 2015

The uptake of radiocalcium by nerve‐ending particles isolated from rat brain was studied in vitro by means of a rapid lanthanum quenching technique.
The observed uptake fits a theoretical three‐compartment model with two separate uptake phases, a fast, initial phase followed by a late, slow phase. This holds true during control conditions as well as during high‐potassium stimulation.
The uptake as a function of the external calcium concentration can be described in terms of Michaelis‐Menten kinetics during high‐potassium stimulation. Under control conditions the fit is clearly applicable but statistically not as good as during potassium stimulation.
The affinity for the uptake of calcium remains unchanged under control conditions while during high‐potassium stimulation the affinity drastically decreases during the late, slow phase of uptake.
During high‐potassium stimulation the maximal velocity of calcium uptake is twice that during control conditions. This holds true for both the fast and the slow phases of the uptake.
Mg2+ has an inhibitory effect on the uptake, the inhibition being more effective during high‐potassium stimulation. Tetrodotoxin has a slight inhibitory effect additional to that exerted by Mg2+ during the initial phase of uptake into high potassium stimulated synaptosomes.
DO MOTOR‐NERVE TERMINALS HAVE γ‐AMINOBUTYRIC ACID RECEPTORS?
Authors: SMART T.G. 
Published: May 2015

γ‐Aminobutyric acid (GABA, 0.1 to 1 mm) had no significant effect on the amplitude, rise time, half decay time or frequency of miniature endplate potentials (m.e.p.ps) at the frog or mouse neuromuscular junctions in vitro.
Addition of GABA (1 mm) to preparations previously treated with 11 mm K+‐Ringer did not cause any further increase in m.e.p.p. frequency. GABA also failed to increase the m.e.p.p. frequency in a low Cl−‐Ringer.
GABA (0.1 to 1 mm) did not reduce the high m.e.p.p. frequency induced by veratrine (20 to 40 mg/l).
GABA (0.5 to 1 mm) did not affect the amplitude of the extracellularly‐recorded nerve terminal spike, whereas 15 mm [K+] reduced the spike.
The quantal content (m) of the evoked endplate potential was not significantly altered by GABA; 9 mm [K+] significantly increased m.
When external d.c. potential differences were recorded in a three‐chambered bath, GABA (0.1 to 1 mm) produced a very small depolarization if applied to the phrenic nerve trunk, but not if applied to the pre‐terminal axon/motor nerve terminal region. Carbachol (0.3 to 1 mm) evoked a small depolarization when applied to the nerve terminal chamber.
These results fail to provide evidence for the existence of GABA receptors on motor nerve terminals.
EFFECT OF TILTING ON THE PRESSOR RESPONSES TO McN‐A‐343, A MUSCARINIC SYMPATHETIC GANGLION STIMULANT
Authors: FIELDEN R. , SUTTON T.J. , TAYLOR E.M. 
Published: May 2015

In anaesthetized cats and dogs treated with mecamylamine, the pressor response to McN‐A‐343 was increased when the animals were changed from a supine to a head‐up, tilted position. This potentiation was not seen in rats.
The potentiation of the McN‐A‐343 pressor response was not affected by propranolol, destruction of the brain, or removal of the intestines, spleen or adrenal glands. It was promptly abolished by applying pressure to the lower half of the tilted animal. No increase in the pressor response to McN‐A‐343 occurred when cats were tilted head down. The potentiated response in tilted cats was abolished by atropine.
The pressor effects of adrenaline, noradrenaline, tryamine and angiotensin in cats treated with mecamylamine were either reduced or unchanged when the animal was changed from the supine to the tilted position. In one cat not treated with mecamylamine in which orthostatic hypotension occurred, tilting potentiated the pressor responses to dimethyl phenylpiperazinium iodide.
In cats anaesthetized with chloralose, the reflex pressor response to bilateral carotid occlusion was reduced by tilting. After mecamylamine treatment the residual atropine‐sensitive response to carotid occlusion was potentiated when the animal was placed in the tilted position.
These results suggest that muscarinic stimulation of sympathetic ganglia by McN‐A‐343 raises blood pressure by predominantly reducing venous capacity, in contrast to noradrenaline and angiotension which increase blood pressure mainly by arterial vasoconstriction.
It is not clear whether this is a general property of sympathetic ganglionic stimulation or is restricted to stimulation of muscarinic sites.
A STUDY OF THE ROLE OF CYCLIC ADENOSINE 3′,5′‐MONOPHOSPHATE IN THE DEPRESSION BY OPIATES AND OPIOID PEPTIDES OF EXCITATORY JUNCTION POTENTIALS IN THE MOUSE VAS DEFERENS
Authors: NORTH R.A. , VITEK L.V. 
Published: May 2015

Excitatory junction potentials (e.j.ps) were recorded with intracellular microelectrodes from smooth muscle cells of the mouse isolated vas deferens. The amplitude of the e.j.p. was used as a measure of transmitter release evoked by applying single pulse stimuli to the intramural nerves.
Cyclic adenosine 3′,5′‐monophosphate (cyclic AMP) and dibutyryl cyclic AMP (db cyclic AMP, up to 1 mm) depressed the amplitude of e.j.ps, probably by interacting with extracellular sites on the nerve terminals, similar to those responsive to adenosine.
The phosphodiesterase inhibitors, 1‐methyl‐3‐isobutyl xanthine (IBMX) and 1‐ethyl‐4‐hydrazino‐1H‐pyrazolo(3,4‐b)pyridine‐5‐carboxylic acid, ethylester, hydrochloride (SQ20,006) increased e.j.p. amplitude; this increase was much greater when the phosphodiesterase inhibitor was applied together with db cyclic AMP.
Neither the cyclic nucleotides nor the phosphodiesterase inhibitors altered the resting membrane potential of smooth muscle cells.
The amplitude of the e.j.p. was depressed by normorphine, d‐Ala2‐Met5‐enkephalinamide (DAEA) and d‐Ala2‐d‐Leu5‐enkephalin (DADL) with respective EC50s of 560 nm, 49 nm and 510 pm.
There was no change in the EC50 for normorphine in the presence of cyclic AMP (1 mm) or in the presence of a combination of IBMX (50 μm) and db cyclic AMP (500 μm). Similarly, the depression of the e.j.p. by DAEA or DADL was not affected by the combination IBMX (500 μm) and db cyclic AMP (250 μm).
These findings provide evidence against the hypothesis that a reduction in cyclic AMP levels in nerve terminals is an essential step in the inhibition by opiates and opioid peptides of transmitter release.
Ant tending impairs performance of Aenasius bambawalei by manipulating the honeydew composition produced by Phenacoccus solenopsis
Authors: Zhou A. M. , Kuang B. Q. , Gao Y. R. , Wang M.‐Q. 
Published: May 2015

AbstractHoneydew produced by hemipterans is known as a possible kairomonal resource for parasitoids. The application of artificial honeydew effectively improves the performance of natural enemies. Aenasius bambawalei is a particularly dominant and aggressive endoparasitoid of the invasive mealybug Phenacoccus solenopsis. Our previous study showed that tending by the ghost ant Tapinoma melanocephalum significantly reduced the parasitism of A. bambawalei. We hypothesize that ghost ant tending influences host location of parasitoids by manipulating the composition of the honeydew produced by mealybugs. In this study, we tested whether the honeydew composition differs between treatments with and without ant attendance and whether changes in the honeydew influence the performance of A. bambawalei. Our results show that the sucrose concentration increased significantly in the ant‐attendance treatment but decreased when ant attendance was switched to an ant‐exclusion treatment; the inverse was true for the glucose concentration. Compared with the plastic honeydew treatment (mealybug with ant attendance), parasitoids spent much more time searching, had longer lifespans and showed higher parasitism on filter papers treated with natural honeydew (mealybug without any pre‐treatment) and those treated with convalescent honeydew (mealybug having experienced ant attendance and then switched to ant exclusion). These results support the hypothesis that ant tending influences the performance of parasitoids by manipulating honeydew composition.
Effect of Preoperative Occlusal Matrices on the Vickers Microhardness of Composite Disks Polymerized with QTH and LED Lamps
Authors: Castillo‐Oyagüe Raquel , Milward Paul J. , Martín‐Cerrato Alicia , Lynch Christopher D. 
Published: May 2015

AbstractPurposeThis study aimed to assess the reliability of the preoperative occlusal matrix technique in terms of the surface Vickers microhardness (VMH) of the underlying composite restorative material.Materials and MethodsTwo hundred microhybrid composite cylinders were built up and light‐cured in a single‐layer step, forming two experimental groups (N = 100) according to their heights (1.5 mm/2 mm). Each group was divided into five subgroups (N = 20) depending on the matrix thickness (no matrix/0.5 mm/1 mm/2 mm/3 mm). Half the specimens per subgroup (N = 10) were randomly polymerized with a quartz‐tungsten‐halogen (QTH) light‐curing unit (LCU). The remaining half were cured using a light‐emitting diode lamp. The top and bottom samples' sides were tested for VMH at 1 hour and 24 hours post‐curing using a universal VMH machine. A multiple analysis of variance with repeated measurements for the “surface” factor and the Student–Newman–Keuls test were run (α = 0.05). Bottom/top microhardness ratios were compared with the empirically accepted limit (0.8). Surface topography was analyzed under a scanning electron microscope.ResultsThe thinnest matrices provided the significantly best VMH values. LCU, disc height, and time also contributed to VMH. At 24 hours, 2‐mm high discs polymerized with QTH resulted in inadequate microhardness ratios when 1‐mm thick to 3‐mm thick matrices were used.ConclusionThe thinnest matrices are the most recommendable ones.Clinical SignificanceThe esthetics and occlusal reproducibility achieved with customized occlusal matrices fabricated before cavity preparation have been widely demonstrated. However, their effect on the physical properties of the restorations deserves further investigation. Although more studies are necessary, the thinnest matrices seem to be the most suitable to preserve the composite surface VMH and the curing depth.
Full Mouth Implant Rehabilitation with Staged Approach: 6‐Year Clinical Follow‐Up
Authors: Papaspyridakos Panos 
Published: May 2015

AbstractObjectiveThe transition of patients from failing dentition to complete arch implant rehabilitation often requires that the patient is rendered edentulous and has to wear a removable complete denture for varying periods of time. In order to avoid removable provisionalization, the staged treatment approach allows for fixed interim prosthesis throughout the rehabilitation process, patient comfort, and prosthodontic control.Clinical considerationsThe purpose of this clinical report is to describe a combination of staged approach with guided flapless surgery for minimally invasive treatment. The patient had fixed interim prostheses during the entire rehabilitation process. The various implant prosthodontic stages are illustrated for the complete arch prosthetic rehabilitation and the 6‐year follow‐up outcome is reported. A patient with debilitated dentition was treated with this combined protocol and was followed for 6 years after definitive prosthesis insertion.ConclusionImplant and prosthesis success rates were 100% with minor biologic and no technical complications encountered up to 6‐year recall. Guided surgery has the advantage of prosthetically driven implant placement and minimal postoperative sequelae, whereas the staged approach allows for fixed provisionalization throughout the entire treatment period.Clinical SignificanceAs the computer‐guided surgery protocols continue to evolve and improve, further clinical studies are necessary to assess accuracy and make this exciting technology even safer for the average clinician. The clinical significance of this case report lies in the treatment sequence combined with cutting edge technology for maximum patient comfort and prosthodontic control. Guided flapless surgery with prosthodontically driven implant placement led to predictable rehabilitation with no major complications after 6 years. A staged approach with fixed interim prostheses was used throughout the entire rehabilitation period, optimizing patient satisfaction and comfort. Natural canine guidance was the occlusal scheme of choice.
Protracted garnet growth in high‐Peclogite: constraints from multiple geochronology andP–Tpseudosection
Authors: Cheng H. , Cao D. 
Published: May 2015

AbstractUnderstanding convergent margin processes requires determination of the onset and the termination of subduction, the duration of subduction‐zone metamorphism, and the subduction zone polarity. Garnet growth and intracrystalline zonation can be used to constrain the timing, duration and kinetics of tectonometamorphic processes. An eclogite from the Huwan shear zone in the Hong'an orogen was investigated with combined pseudosection analysis and multiple geochronologies. The pseudosection analysis illustrates that garnet growth is continuous and along an early near‐isothermal trajectory followed by a near‐isobaric heating path from 1.9 GPa/500 °C to 2.4 GPa/575 °C and subsequent near‐isothermal decompression.40Ar/39Ar dating of an amphibole inclusion in garnet from the eclogite yielded an age of 310 ± 5 Ma, which is consistent with a U–Pb age of 305 ± 3 Ma for the metamorphic zircon within uncertainty. Garnet core and rim material produced Lu–Hf ages of 296.9 ± 3.8 and 256.9 ± 3.9 Ma respectively; the latter is consistent with its Sm–Nd age of 254.3 ± 4.6 Ma for the same aliquots. Similarly, limited zircon U–Pb ages ofc. 257 Ma were obtained in zircon rims with garnet inclusions. These ages were interpreted to bracket the period of garnet growth and the difference of up toc. 40 Ma is best explained by protracted garnet growth. We propose that the rocks represent detachment of part of the downgoing slab and remained free of significant compression/decompression or heating/cooling close to the subduction channel, most likely underplating the mantle wedge, for a long time. These rocks were incorporated into the following subduction channel due to the successive entry of the buoyant materials, and exhumed at some time later thanc. 254 Ma. The increasing observations of protracted garnet growth and long‐lived subduction in various orogens worldwide demand more sophisticated geodynamic models.
Light‐dependent gene activation in Aspergillus nidulans is strictly dependent on phytochrome and involves the interplay of phytochrome and white collar‐regulated histone H3 acetylation
Authors: Hedtke Maren , Rauscher Stefan , Röhrig Julian , Rodríguez‐Romero Julio , Yu Zhenzhong , Fischer Reinhard 
Published: May 2015

SummaryThe ability for light sensing is found from bacteria to humans but relies only on a small number of evolutionarily conserved photoreceptors. A large number of fungi react to light, mostly to blue light. Aspergillus nidulans also responds to red light using a phytochrome light sensor, FphA, for the control of hundreds of light‐regulated genes. Here, we show that photoinduction of one light‐induced gene, ccgA, occurs mainly through red light. Induction strictly depends on phytochrome and its histidine‐kinase activity. Full light activation also depends on the Velvet protein, VeA. This putative transcription factor binds to the ccgA promoter in an fphA‐dependent manner but independent of light. In addition, the blue light receptor LreA binds to the ccgA promoter in the dark but is released after blue or red light illumination and together with FphA modulates gene expression through histone H3 modification. LreA interacts with the acetyltransferase GcnE and with the histone deacetylase HdaA. ccgA induction is correlated to an increase of the acetylation level of lysine 9 in histone H3. Our results suggest regulation of red light‐induced genes at the transcriptional level involving transcription factor(s) and epigenetic control through modulation of the acetylation level of histone H3.
When blood transfusion medicine becomes complicated due to interference by monoclonal antibody therapy
Authors: Oostendorp Marlies , Lammerts van Bueren Jeroen J. , Doshi Parul , Khan Imran , Ahmadi Tahamtan , Parren Paul W.H.I. , van Solinge Wouter W. , De Vooght Karen M.K. 
Published: May 2015

BACKGROUNDMonoclonal antibodies (MoAbs) are increasingly integrated in the standard of care. The notion that therapeutic MoAbs can interfere with clinical laboratory tests is an emerging concern that requires immediate recognition and the development of appropriate solutions. Here, we describe that treatment of multiple myeloma patients with daratumumab, a novel anti‐CD38 MoAb, resulted in false‐positive indirect antiglobulin tests (IATs) for all patients for 2 to 6 months after infusion. This precluded the correct identification of irregular blood group antibodies for patients requiring blood transfusion.STUDY DESIGN AND METHODSThe IAT was performed using three‐ and 11‐donor‐cell panels. Interference of daratumumab and three other anti‐CD38 MoAbs was studied using fresh‐frozen plasma spiked with different MoAb concentrations. Additionally it was tested whether two potentially neutralizing agents, anti‐idiotype antibody and recombinant soluble CD38 (sCD38) extracellular domain, were able to inhibit the interference.RESULTSThe CD38 MoAbs caused agglutination in the IAT in a dose‐dependent manner. Addition of an excess of anti‐idiotype antibodies or sCD38 protein to the test abrogated CD38 MoAb interference and successfully restored irregular antibody screening and identification.DISCUSSIONCD38 MoAb therapy causes false‐positive results in the IAT. The reliability of the test could be restored by adding a neutralizing agent against the CD38 MoAb to the patient's plasma. This study emphasizes that during drug development, targeted therapeutics should be investigated for potential interference with laboratory tests. Clinical laboratories should be informed when patients receive MoAb treatments and matched laboratory tests to prevent interference should be employed.