bluuebunny/crossref_metadata_2025_split huggingface dataset:
[Bis(tetrahydrofuran–O)–bis(1,3–dialkyl–2–diphenylphosphanyl–1,3–diazaallyl)calcium] – Synthesis and Crystal Structures of Calcium Bis[phospha(III)guanidinates] and Investigations of Catalytic Activity
Authors: Al–Shboul Tareq M. A. , Volland Gritt , Görls Helmar , Westerhausen Matthias 
Published: June 2009

AbstractThe reaction of [(thf)4Ca(PPh2)2] (1) with diisopropyl– and dicyclohexylcarbodiimides yields the phospha(III)guanidinates [(thf)2Ca{RNC(PPh2)NR}2] with R = isopropyl (2) and cyclohexyl (3). The metathesis reaction of K{RNC(PPh2)NR} with anhydrous CaI2 also allows the synthesis of these phospha(III)guanidinate complexes 2 and 3. For 2 a cis arrangement is observed whereas 3 crystallizes as trans isomer. The phospha(III)guanidinates act as bidentate chelate bases with an average Ca–N distance of 242.5 pm. The C–P bond length between the PPh2 fragment and the 1,3–diazaallyl unit is with values above 190 pm very large. The complexes 2 and 3 show a moderate catalytic activity in hydrophosphanylation reactions of dialkylcarbodiimides with diphenylphosphane.
A Pilot Study to Assess the Feasibility of a Multicenter Cluster Randomized Trial for the Management of Asymptomatic Persons with a Thrombophilia
Authors: Wells Philip S. , Louzada Martha L. , Taljaard Monica , Anderson David R. , Kahn Susan R. , Langlois Nicole J. , Rutberg Julie , Kovacs Michael J. , Rodger Marc A. 
Published: June 2009

AbstractThere is controversy whether asymptomatic first‐degree relatives (FDRs) of patients with venous thromboembolism (VTE) and thrombophilia should be screened, followed, and prescribed prophylaxis during risk periods. We recruited consecutive probands with idiopathic VTE and thrombophilia from our thrombosis clinics. Those FDRs with thrombophilia were randomized in family clusters to receive one‐time verbal counseling and no organized follow‐up or counseling, educational material, reminder aids and follow‐up. Only 203 of 1,129 FDRs were eligible and consented. Dropouts were common; 1 FDR (1.7%) developed VTE. VTE risk, ability to treat and prevent were underestimated by the participants. Patients with VTE and thrombophilia and their FDRs are often not interested in thrombophilia testing. Despite education to inform their knowledge, interest and follow‐up were less than ideal. The question of the best educational approach in these patients remains unanswered. The value of testing and following asymptomatic carriers of probands with VTE and thrombophilia remains unknown.
Improved bracing compliance in children with clubfeet using a dynamic orthosis
Authors: Garg Sumeet , Porter Kristina 
Published: June 2009

Purpose Non-compliance with foot abduction bracing in children with clubfeet treated with the Ponseti method is the leading risk factor for deformity recurrence. A dynamic foot abduction orthosis is believed to result in improved compliance, fewer skin complications, and fewer recurrences. A case–control trial was conducted to test this hypothesis. Methods A prospective cohort of children with idiopathic clubfoot using a dynamic brace was compared to a historical control group treated with a standard orthosis. Compliance, skin complications, recurrence, and the need for surgical soft tissue release were compared between groups at equivalent follow-up. Results The dynamic and standard brace groups are equivalent in age at the start of treatment (1.9 vs. 2.9 months), number of affected feet (97 vs. 92), and severity (average of four casts required for correction in each group). Fifty-seven children were followed in each group for an average of 2 years. All were corrected initially with the Ponseti method. Compliance is higher using the dynamic brace (47/57, 81%) compared to the standard brace (21/57, 47%) ( P < 0.001). The recurrence rate is lower using the dynamic brace (11/57, 19%) compared to the standard brace (22/57, 39%) ( P < 0.02). Skin complications are fewer in the dynamic brace (2/57, 3%) compared to the standard brace (11/57, 19%) ( P < 0.008). Most importantly, five children using the standard brace underwent posteromedial release within 2 years of treatment, compared to none in the dynamic brace group. Conclusion The dynamic foot abduction brace results in improved compliance, fewer recurrences, fewer skin complications, and reduced rates of surgery in idiopathic clubfoot than the traditional brace after non-operative correction with the Ponseti method.
Ecobiological survey of the brine shrimp Artemia salina from Sabkhet El Adhibet (south-east Tunisia)
Authors: Ben Naceur Hachem , Ben Rejeb Jenhani Amel , Romdhane Mohamed Salah 
Published: June 2009

In order to provide a better characterization and understanding of the brine shrimp Artemia salina life-cycle, different ecological and biological parameters were taken out monthly during two periods from November 2005 to April 2006 and from November 2006 to April 2007 in Sabkhet El Adhibet (south-east Tunisia). Variation of water temperature, salinity, pH, dissolved oxygen, nutrients (orthophosphate, nitrites, nitrates and ammonium) and phytoplankton density were monitored. The Artemia population was also surveyed. Artemia were present in the site with salinity between 32.2 and 281.7 g l−1 and water temperature between 12.1 and 25.4°C. The pH ranged from 7.6 to 9 and dissolved oxygen concentration from 3.4 to 17.5 mg l−1. Minimum and maximum values of phytoplankton density were 0.19 and 14.59 106 cell l−1. In addition, the nutrient analysis registered showed that nitrate and ammonium represent the major nutrient. The Artemia population density fluctuated between 0.22 and 38.57 individuals per litre. The male:female ratio was dominated by the males. Artemia from Sabkhet El Adhibet showed variability in fecundity (total offspring and brood size) as well as in the ratio encystment/oviviparity. The individual fecundity fluctuates between 29.4 and 70.2 cysts and 17.8 and 69.8 nauplii. Finally, the influence of physical and chemical parameters as well as phytoplankton density over the Artemia population was noticed.
Differential effects of α-helical and β-hairpin antimicrobial peptides against Acanthamoeba castellanii
Authors: SACRAMENTO R. S. , MARTINS R. M. , MIRANDA A. , DOBROFF A. S. S. , DAFFRE S. , FORONDA A. S. , DE FREITAS D. , SCHENKMAN S. 
Published: June 2009

SUMMARYIn this work we evaluated the ability of different types of antimicrobial peptides to promote permeabilization and growth inhibition of Acanthamoeba castellanii trophozoites, which cause eye keratitis. We used cationic α-helical peptides P5 and P6, corresponding to the N-terminus of the pore-forming protein from Triatoma infestans, a blood-sucking insect, and a β-hairpin amphipathic molecule (gomesin), of the spider Acanthoscurria gomesiana haemocytes. A. castellanii permeabilization was obtained after 1 h incubation with micromolar concentrations of both types of peptides. While permeabilization induced by gomesin increased with longer incubations, P5 permeabilization did not increase with time and occurred at doses that are more toxic for SIRC cells. P5, however, at doses below the critical dose used to kill rabbit corneal cells was quite effective in promoting growth inhibition. Similarly, P5 was more effective when serine protease inhibitor was added simultaneously to the permeabilization assay. High performance chromatography followed by mass spectrometry analysis confirmed that, in contrast to gomesin, P5 is hydrolysed by A. castellanii culture supernatants. We conclude that the use of antimicrobial peptides to treat A. castellanii infections requires the search of more specific peptides that are resistant to proteolysis.
Early CD44hiCD4+and CD44hiCD8+T cell numbers and the absence of mannose-rich glycoconjugates determine the protective outcome of anti-leishmanial immunity
Authors: KEDZIERSKI L. , CURTIS J. M. , KEDZIERSKA K. 
Published: June 2009

SUMMARYVaccination remains the best hope for control of all forms of leishmaniasis, and the development of a safe and effective vaccine is a critical global public-health priority. Our previous work showed that immunization with non-persistent phosphomannomutase-deficient (ΔPMM)Leishmania majorparasites confers significant protection in susceptible BALB/c mice due to increased T-cell numbers and suppression of IL-10 and IL-13 early during infection. Here, we complemented the ΔPMML. majorparasites with human PMM2 to determine whether we could further improve the protection. Complemented ΔPMM parasites have restored glycoconjugate biosynthesis, while retaining avirulence of the parental knockout strain. Immunization with hPMM2 add-back parasites showed similar Th1/Th2 cytokine profiles to that observed in ΔPMM-vaccinated mice. However, the numbers of the activated CD4+CD44hiand CD8+CD44hiT cells recruited to the draining lymph nodes early afterLeishmaniainfection were reduced, leading to decreased protection following hPMM2-immunization. Thus, the magnitude of T-cell responses early in the infection and the absence of mannose-rich glycoconjugates determine the protective outcome of anti-leishmanial immunity.
Retinotopic representation of the bifoveate eye of the kestrel (Falco sparverius) on the optic tectum
Authors: Frost B. J. , Wise L. Z. , Morgan B. , Bird D. 
Published: June 2009

AbstractLike many diurnal raptors, the American kestrel or sparrow hawk, Falco sparverius, possesses two foveae in each eye. In this study, we used fundus photography and reversed ophthalmoscopy to plot the projection of these foveae onto the visual field, together with other retinal landmarks such as the pecten and ora terminali. From such data, it was determined that the central monocular fovea (CMF) and temporal binocular fovea (TBF) were separated by 36 deg and that the kestrel has 58 deg of binocular overlap when the eyes are appropriately converged. Single-cell and multi-unit recordings were used to systematically explore the tectal surface and map receptive fields (RF) onto a hemispheric screen. A retinotopic map of the tectal surface was produced from such data and revealed an expanded representation for each fovea on the tectum and a systematic increase in RF size from fovea to periphery. The functional significance of this organization is discussed.
Development of flash-evoked responses in the ectostriatum of the zebra finch: An evoked potential and current-source-density analysis
Authors: Engelage J. , Bischof H.-J. 
Published: June 2009

AbstractThe morphological development of the tectofugal pathway in the zebra finch has recently been described in a series of studies from our laboratory. No data are currently available on the development of visual responsiveness in this pathway. We therefore investigated the development of visually evoked potentials (VEPs) in the ectostriatum, the telencephalic target area of the tectofugal pathway. Contralateral VEPs could already be recorded in 20-day-old birds, whereas ipsilateral VEPs could first be recorded in 40-day-old birds. The latencies of contralateral VEPs decrease to adult values between 20 and 40 days of age, probably due to an increase in the myelination of afferent fibers. The amplitudes of the contralateral VEPs increase continuously from day 20 to day 60; however, between 60 and 80 days of age the responses diminish substantially (−60%). Thus, contralateral VEPs in 80-day-old birds are not significantly different from those in 20-day-old birds. Thereafter the responses recover and reach their final amplitude values at about 150 days of age. The relationship of these results to morphological studies and possible mechanisms which may cause the double-peaked development of visual-evoked potentials in the ectostriatum are discussed.
Development of geniculocortical axon arbors in a primate
Authors: Florence S. L. , Casagrande V. A. 
Published: June 2009

AbstractThe main objective of the present study was to describe the postnatal development of magnocellular and parvocellular LGN axons within the primate striate cortex. For this purpose, we bulk labeled axons in neonatal prosimians (galagos) in vivo or in vitro at regular intervals from birth (PO) to 12 weeks after birth by injecting horseradish peroxidase (HRP) into white matter anterior to the striate cortex. Filled axons within layer IV were reconstructed, quantitatively analyzed, and compared to a population of adult axons described previously (Florence & Casagrande, 1987).Our results show that although axons are morphologically immature at birth, they are restricted to the upper (IVα) and lower (IVβ) tiers of layer IV of the striate cortex as in adults. In adults, we referred to the presumed magnocellular LGN axons terminating in IVα as type I and the presumed parvocellular axons terminating in IVβ as type II. We used the same convention for developing axons.From birth to 3 weeks postnatal, type I and II axon classes are more variable in appearance than adult counterparts, and are not morphologically class distinct. As axons mature, parent axon shafts increase in caliber, arbors become smaller and more radial, and other immature features (e.g. spikes, protrusions, growth cones) are less evident. Both arbor classes mature slowly and some still exhibit immature features (e.g. growth cones) as late as 12 weeks postnatally. Although arbors do not show class-distinctive features until late in development, each class does show some unique maturational trends. Type I arbors are only slightly larger than adult counterparts at birth, whereas type II arbors are dramatically larger. Type I arbors increase in branch complexity with age, whereas type II arbors simply show a shift in complexity toward the center of the arbor with decreasing size over time. These growth trends suggest that magnocellular and parvocellular pathways to cortex could be differentially vulnerable to the manipulation of postnatal visual experience.
A quantitative measure of the electrical activity of human rod photoreceptors using electroretinography
Authors: Hood Donald C. , Birch David G. 
Published: June 2009

AbstractAn eletrical potential recorded from the cornea, the a-wave of the ERG, is evaluated as a measure of human photoreceptor activity by comparing its behavior to a model derived fromin vitrorecordings from rod photoreceptors. The leading edge of the ERG exhibits both the linear and nonlinear behavior perdicted by this model. The capability for recording the electrical activity of humans photoreceptors inin vivoopens new avenues for assessing normal and abnormal receptor activity in humans. Furthermore, the quantitative model of the receptor response can be used to isolate the inner retinal contribution, Granit's PII, to the gross ERG. Based on this analysis, the practice of using the trough-to-peak amplitude of the b-wave as a proxy for the amplitude of the inner nuclear layer activity is evaluated.
Colocalization of substance P and GABA in retinal ganglion cells: A computer-assisted visualization
Authors: Caruso Daniel M. , Owczarzak Michael T. , Pourcho Roberta G. 
Published: June 2009

AbstractGanglion cells in the albino rat retina were retrogradely labeled with the fluorescent dye, diamidino-yellow, from the superior colliculus. Preembedding and postembedding immunocytochemical techniques were employed in conjunction with computer-assisted image processing to visualize SP- and GABA-immunoreactivity. Examination of flatmount and sectioned retinas revealed that approximately 3% of the ganglion cells projecting to the contralateral superior colliculus exhibit SP-immunoreactivity. Moreover, these cells were found to comprise a subpopulation of the GABA-immunoreactive cells projecting to the rat tectum.
Contribution of quisqualate/ kainate and NMDA receptors to excitatory synaptic transmission in the rat's visual cortex
Authors: Nishigori A. , Tsumoto T. , Kimura F. 
Published: June 2009

AbstractActions of antagonists for excitatory amino-acid (EAA) receptors on extracellularly and intracellularly recorded responses of layer II/III cells to electrical stimulation of the underlying white matter were studied in a slice preparation of rat's visual cortex. Antagonists used were 2-amino-5-phosphonovalerate (APV) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), which are selective antagonists for EAA receptors of N-methyl-D-aspartate (NMDA) and quisqualate/kainate (non-NMDA) type, respectively. In extracellular recordings, it was found that responses of almost all of the cells were suppressed by CNQX. In contrast, sensitivity to APV was different between cells with short- and long-latency responses; 81% of the former responses were not suppressed by APV, while about a half of the latter were suppressed. Excitatory postsynaptic potentials (EPSPs) evoked by white-matter stimulation were recorded intracellularly from 42 neurons. Most of polysynaptically elicited EPSPs were sensitive to APV, whereas the majority of monosynaptic EPSPs were not. CNQX almost completely suppressed EPSPs irrespective of monosynaptically or polysynaptically evoked, but in some cases slow EPSPs with low amplitude were spared. These CNQX-resistant EPSPs were elicited polysynaptically and had an anomalous voltage dependence, a characteristic of NMDA receptors. It is suggested that non-NMDA receptors contribute dominantly to first-order synaptic transmission while NMDA receptors participate substantially in second-order transmission so as to serve as a booster of outputs from visual cortex.
Green-sensitive cone photoreceptors are selectively labeled by Procion yellow dye in goldfish retina
Authors: Petry Heywood M. , Bassi Carl J. 
Published: June 2009

AbstractSelective labeling of intravitreal Procion yellow dye by presumed blue-sensitive cone photoreceptors has been demonstrated in primate retina. To determine whether Procion yellow is selective for this cone type in an unrelated vertebrate species, labeling by this dye was studied in goldfish retina, where cone pigment type can be directly inferred from photoreceptor morphology. At low vitreal concentrations of the dye (<0.4%), only cone outer segments were labeled. At vitreal concentrations of 0.4–0.5%, the inner segments of short-double cones and a subset of long single cones (presumed green-sensitive cones) were selectively stained. At still higher vitreal concentrations (0.6–0.7%), the inner segments of short-single cones and miniature short-single cones (presumed blue-sensitive cones) showed evidence of Procion label, but were not as heavily labeled. The inner segments of long-double cones and a subset of long-single cones (presumed red-sensitive cones) did not label at any of these concentrations. These results show that Procion yellow is not a selective marker for blue-sensitive cones in the goldfish retina. In addition, stained rod and cone nuclei were observed at each dye concentration, including those concentrations at which no inner segments were labeled.
An unusual voltage-gated anion channel found in the cone cells of the chicken retina
Authors: Wilson Martin , Gleason Evanna 
Published: June 2009

AbstractUsing the whole-cell patch clamp technique, we have examined the voltage-gated currents present in adult chicken cone cells. When calcium and calcium-gated currents are blocked, hyperpolarizing voltage steps elicit slowly increasing inward currents as has been shown for photoreceptors in other species. Unlike the case for other species, chicken cones appear to lack the inward-rectifying cationic current Ih that contributes to the shaping of the photovoltage. Instead of Ih, these cones possess an anionic inward-rectifying current that in kinetics, activation range and probably function is remarkably similar to Ih. This anion channel is unusual in that both nitrate and acetate are more permeant than chloride ions.
Neural organization of the retina of the turtleMauremys caspica:a light microscope and Golgi study
Authors: Kolb Helga , Perlman Ido , Normann Richard A. 
Published: June 2009

AbstractThe organization of the retina of the turtle speciesMauremys caspica, found in fresh water ponds of Israel, has been examined by light microscopical techniques including examination of fresh wholemount retina, one micron blue-stained vertical sections and Golgi-stained material. The anatomical findings onMauremysretina have been compared with those of thePseudemysretina (Kolb, 1982) which is more commonly used for electrophysiological and neurochemical studies in the USA. The photoreceptors ofMauremysare similar in type and oil droplet content toPseudemysphotoreceptors except for the double cone inMauremys.This cone type appears more abundant than inPseudemysand the principal member contains a yellow oil droplet instead of an orange oil droplet. Golgi staining reveals that all the cell types that have been seen inPseudemysare found inMauremyswith identical morphology. In addition, two amacrine cell types that were not before described forPseudemyshave been added to the classification. One of these is the tristratified dopaminergic amacrine cell described in immunocytochemical studies (Witkovsky et al., 1984; Nguyen-Legros et al., 1985; Kolb et al., 1987). We have used these anatomical studies onPseudemysandMauremysretina to form a catalogue of neural types for the turtle retina in general. We conclude with an attempt to combine findings from anatomy, electrophysiology, and neurochemistry to form an overview of the organization of this reptilian retina.
Prenatal disruption of binocular interactions creates novel lamination in the cat's lateral geniculate nucleus
Authors: Garraghty Preston E. , Shatz Carla J. , Sur Mriganka 
Published: June 2009

AbstractThe elimination of retinogeniculate afferents from one eye on embryonic day 44 (E44) has pronounced effects on the formation of the cellular laminae in the cat lateral geniculate nucleus (LGN). Only two laminae form: a dorsal, “magnocellular” layer, and a ventral, “parvocellular” layer. Soma size measurements and previously reported patterns of termination of retinogeniculate axons suggest that the dorsal lamina is a coalescence of the normal A-laminae and the dorsal, magnocellular division of layer C, while the ventral layer is a composite of the parvocellular sublamina of layer C and the remaining C-laminae. This is a novel pattern of lamination in the LGN that differs from that found in the normal nucleus, not only in that there are now only two cell layers rather than the normal five, but also in that the interlaminar zone occurs in an abnormal location. This result is markedly different from that observed in other species where interlaminar zones present after early monocular enucleation are a subset of the ones which would normally be present. We suggest that, in the absence of ongoing binocular interactions, interactions between functionally distinct retinal ganglion cell classes from the remaining eye may direct the formation of cell laminae in the LGN, even when such interactions are not normally operative.