Miracle-dz/UniFAR-FTUs huggingface dataset:
Dependence of μ-Conotoxin Block of Sodium Channels on Ionic Strength but Not on the Permeating [Na+]

μ-Conotoxins (μ-CTXs) are Na+ channel-blocking, 22-amino acid peptides produced by the sea snail Conus geographus. Although K+ channel pore-blocking toxins show specific interactions with permeant ions and strong dependence on the ionic strength (μ), no such dependence has been reported for μ-CTX and Na+ channels. Such properties would offer insight into the binding and blocking mechanism of μ-CTX as well as functional and structural properties of the Na+ channel pore. Here we studied the effects of μ and permeant ion concentration ([Na+]) on μ-CTX block of rat skeletal muscle (μ1, Nav1.4) Na+ channels. μ-CTX sensitivity of wild-type and E758Q channels increased significantly (by ∼20-fold) when μ was lowered by substituting external Na+ with equimolar sucrose (from 140 to 35 mm Na+); however, toxin block was unaltered (p > 0.05) when μ was maintained by replacement of [Na+] with N-methyl-d-glucamine (NMG+), suggesting that the enhanced sensitivity at low μ was not due to reduction in [Na+]. Single-channel recordings identified the association rate constant, kon, as the primary determinant of the changes in affinity (kon increased 40- and 333-fold for μ-CTX D2N/R13Q and D12N/R13Q, respectively, when symmetric 200 mm Na+ was reduced to 50 mm). In contrast, dissociation rates changed <2-fold for the same derivatives under the same conditions. Experiments with additional μ-CTX derivatives identified toxin residues Arg-1, Arg-13, and Lys-16 as important contributors to the sensitivity to external μ. Taken together, our findings indicate that μ-CTX block of Na+ channels depends critically on μ but not specifically on [Na+], contrasting with the known behavior of pore-blocking K+ channel toxins. These findings suggest that different degrees of ion interaction, underlying the fundamental conduction mechanisms of Na+ and K+ channels, are mirrored in ion interactions with pore-blocking toxins.
Meeting Review: Advances from the GPCR Retreat

In London, Ontario, the 8th Annual Joint meeting of the Great Lakes GPCR Retreat and the Club des Récepteurs à Sept Domaines Transmembranaires (now known simply as the GPCR Retreat) was held September 27–29, 2007. This meeting gathers together a core group of investigators from Michigan, Ontario, and Québec and has steadily increased its attendance in both the eastern (Europe) and western (USA, Canada) directions. The highlight this year was a sneak preview of the β2AR crystal structure provided by Brian Kobilka, but as can be seen below, many other cutting edge talks were heard as well.
Binucleate Rhizoctonia sp. AG G causing root rot in yacon (Smallanthus sonchifolius) in Brazil

A new rot caused by a binucleate Rhizoctonia sp. affecting the tuberous root cortex of the domesticated yacon (Smallanthus sonchifolius) has been observed in Brazil. Isolates of a binucleate Rhizoctonia sp. were collected from roots with rot symptoms and characterized by the number of nuclei per cell, hyphal anastomosis, RAPD molecular markers, ITS-5·8S rDNA sequence and pathogenicity tests. All isolates had a mean of 1·9–2·2 nuclei per cell and anastomosed with the binucleate Rhizoctonia sp. AG G-tester strain. RAPD analysis was carried out between 11 isolates recovered from yacon and 11 AG (A, Ba, Bb, Bo, C, D, F, G, O, P, Q) standard testers of binucleate Rhizoctonia sp. Genetic similarities of 94·8–100% were observed among isolates of the binucleate Rhizoctonia sp. from yacon and all isolates were genetically more closely related to the AG G tester than other strains according to upgma analysis using RAPD markers. Homologies of complete ITS nucleotide sequences were 100% between binucleate isolates of Rhizoctonia sp. from yacon and the AG G tester. According to pathogenicity tests, the isolates caused typical rot symptoms of yacon tubers 90 days after inoculation
Digestion in sheep of diets containing naked oats or barley

Four sheep fitted with cannulas in the rumen and proximal duodenum were used to compare the digestion of two diets in an experiment conducted according to a two-period reversal design with 28-day periods. Chopped hay (400 g day−1) was given with either 500 g barley and 120 g soya bean meal day−1or 500 g naked oats and 100 g soyabean meal day−1. Digestion in the stomach, duodenal flow and faecal excretion of chemical constituents were measured using chromium-mordanted straw as a marker. As a consequence of compositional differences between the cereals, daily intakes of neutral detergent fibre (NDF), acid detergent fibre (ADF) and total fatty acids were 331 and 295, 172 and 161, and 12·1 and 36·9 g for the barley and the naked oats diet respectively. Dietary substitution of naked oats for barley reduced (P < 0.05) the extents to which NDF and ADF were digested in the stomach. There was an associated decrease (P < 0.05) in the proportion of acetic acid in the rumen volatile fatty acids, and the proportion of propionic acid tended to be increased. Rumen ammonia N concentration was reduced (P < 0.05). Duodenal passage of total N and non-ammonia N was increased (P < 0.001), as was that of total fatty acids (P < 0.05),when naked oats were given but there were no significant differences between diets in N or total fatty acid digestibilities in the total tract. The results show that dietary substitution of naked oats for barley can alter ruminal digestion through effects that appear to derive from the associated increase in lipid intake.
Rates of Evolution and the Notion of "Living Fossils"

In one sense, any science is only as sound as the knowledge of its state variables. For paleontology, several of those variables are tied up in the topic of rates of evolution. So uncertain is the mean duration of species that when problems in paleontology are subjected to computer simulation, the values that are used extend over four orders of magnitude (103 to 107 yr; Raup 1981). It should come as no surprise that conclusions over this 104 range support vastly different world views about the extent of determinism versus stochasticity in major evolutionary events. On the one hand, this lack of precision means that virtually any answer is possible. On the other hand, it means that the traditional paleontologic assertion in favor of specific deterministic stories must be tempered by a high degree of uncertainty. The chief body of material to be considered, which was not known to those who formulated the currently prevailing paleontological views on rates of evolution [especially Simpson (1944, 1949, 1953, and largely reaffirmed even in 1983)] lies in information provided on the molecular biology of genomic change. The genome is simply a convenient term for the genetic constitution of an individual or species. Genomic compatibility lies at the basis of reproductive compatibility, and thus genomic change introduces the notion of geonomically regulated reproductive incompat­ ibility. I consider in this article two interrelated aspects of speciation theory. The first is an attempt to integrate the main results from molecular biology that
Mechanisms and regulation of reduction-based iron uptake in plants

Despite the usually high abundance of iron (Fe) in soils, the low solubility of Fe-bearing minerals restricts the available Fe pools in most aerobic soils to levels that are far below those required for microbial or plant growth. To acquire the necessary amounts of Fe from the environment, organisms have evolved mechanisms that enhance the solubility and dissolution rate of Fe(iii) oxyhydroxides prevailing in aerobic soils. Chemically, these mechanisms are based on weakening of the Fe–O bond by reduction, chelation and protonation. Physiologically, two distinct and in all known cases mutually exclusive strategies can be distinguished: the excretion of siderophores capable of solubilizing external ferric Fe and subsequent uptake of the ferric siderophore complex; and reduction of Fe(iii) prior to uptake of the more soluble Fe2+ ion. With the exception of graminaceous species, in which Fe uptake is based on the former mechanism, the latter strategy is found in all cormophytes and certain algae, yeast and bacteria. In higher plants, the increase in their capacity to convert extracellular ferric to ferrous Fe is part of a series of physiological and morphological events that act in concert to achieve appropriate internal levels of Fe. It is this amalgam of features that determines the Fe efficiency of a species or cultivar that in turn affects the yield of economically important plants and the natural distribution of species. Adaptive changes to limited Fe availability have been studied at the molecular, physiological and whole-plant level. This review summarises current knowledge of the components of reduction-based Fe uptake in plants and presents an integrated view of the present understanding of mechanisms that control the rate and extent of Fe absorption by roots.
Mutant of Escherichia coli tolerant to the lysis induced by cephalexin.

growing cells to the lytic action of several (3lactam antibiotics. The first mutation, amiA, reduced the activity of N-acetylmuramyl-Lalanyl amidase3) in the cell extract to about 2•`5% of the normal value, but did not cause any detectable change in phenotypes of the cells. " On the contrary, the second mutation, ptl, did not seem to cause detectable change in the amidase,3) DD-endopeptidases5,6) and seve ral other hydrolytic enzyme activities of cell wall peptidoglycan, while causing the above mentioned phenotypical change of the cell. Minimum inhibitory concentration (MIC) of cephalexin for the mutant cells was about the same as its sensitive parent cells, JE 1011 (mutant: 8 ƒÊg per ml; parent: 16ƒÊg per ml; measured in Lennox-broth7) supplemented with 20ƒÊg per ml thymine). However, the growing mutant cells, under the conditions as shown in Fig. 1 (late log), did not lyse in the presence of 60 times MIC of cephalexin (480 ƒÊg per ml), whereas the parent cells rapidly lysed after addition of 10 times MIC of this antibiotic (160 ƒÊg per ml) (Fig. 1). The mutant cells FIG. 1. Effect of Cephalexin on the Growth of ptl+ and ptl Cells of E. coli Indicating Tolerance of ptl Cells to This Antibiotic. Cells (2 x 108 per ml) were grown in Lennox broth) supplemented with 20 jig per ml thymine (L•L-broth) at 37°C under shaking. When the absorbance of the cells reached 35 in ADS-photometer equipped with 660 nm filter (Fuji Kogyo Co., Tokyo) (corresponding to ca. 1.8•~108 cells per ml), cephalexin was added in concentrations as indicated. (A) Parent strain JE1011 (ptl+ amiA+); (B) mutant strain JST752 (ptl amiA). Symbols: i no addition; 0 160 jig per ml cephalexin added at the arrow; 0 480 ƒÊg per ml cepha lexin added at the arrow.
Osteoarthritis

revious conRestoration, , Crosstrees, al; 9, chair, ard of DirecAPM&R MSK s Committee Abstract: Osteoarthritis of the spine develops as a consequence of the natu process and is associated with significant morbidity and health care expenditures. diagnosis and treatment of the resultant pathologic conditions can be clinically cha Recent evidence has emerged to aid the investigating clinician in formulating an diagnosis and in implementing a successful treatment algorithm. This article d degenerative cascade that results in the osteoarthritic spine, reviews prevalence common painful spinal disorders, and discusses evidence-based treatment op management of zygapophysial and sacroiliac joint arthrosis. PM R 2012;4
STRUCTURE AND REPRODUCTION OF AMANSIA AND MELANAMANSIA GEN. NOV. (RHODOPHYTA, RHODOMELACEAE) ON THE SOUTHEASTERN AFRICAN COAST 1

Four species of Amansia Lamouroux were initially found in Natal. More Complete studies on these species revealed a new genus, Melanamansia, Which is described on the basis of presence of two dorsal pseudopericentral cells in two new species from Natal (M. seagriefii sp. nov. & M. fimbrifolia sp. nov.) in addition to other structural characters and features of pigmentation and reproduction. Pseudopericentral cells are not present in the type species of Amansia, A. multifida Lamouroux. The other two species of Amansia occurring in Natal, A. glomerata C. Agardh & A. loriformis sp. nov., have characters similar to the type species. Comparison of species from other regions of the world has shown that eight additional species, previously assigned to Amansia, belong to the new genus.
New sources of resistance to Meloidogyne incognita race 3 in wild cotton accessions and histological characterization of the defence mechanisms

Accessions of Gossypium spp. , some of them never previously tested, were evaluated for resistance to a local isolate of Meloidogyne incognita race 3 in greenhouse experiments. Nematode infection was characterized based on the galling and egg mass indexes and the reproduction factors (RF). Root-knot nematode reproduction among the newly tested accessions varied from highly susceptible (AS0188, AS0189) to moderately resistant (MT123 no. 3), and some accessions showed highly reduced nematode reproduction (CIR1343, CIR1348, Fai Mui). Histological observations of two resistant accessions (G. barbadense CIR1348 and G. hirsutum TX-25, respectively) showed that resistance occurs through a two-stage mechanism in the first accession and through a single-stage mechanism in the second. Parasitism is blocked early after second-stage juvenile (J2) penetration or during its initial tissue migration (CIR1348) and the development of later-stage juveniles into female adults is suppressed at a later stage (TX-25 and CIR1348). Fluorescence and bright light microscopy showed that root cells surrounding nematodes exhibit a hypersensitivity-like reaction, with the accumulation of presumably phenolic compounds and the presence of necrotic cells that limit the development of nematodes and the formation of giant cells. Underdeveloped giant cells with degenerated cytoplasmic content were found in small numbers in CIR1348 and in large numbers in TX-25, along with deformed nematodes. The full characterization of the defence mechanisms of novel sources of resistance to the root-knot nematode in cotton constitutes a first step towards their use in crop improvement. (Resume d'auteur)
Cell Adhesion via Murine α4 Human β1 Integrin Chimera on Transfected K562 Cells to Endothelial Cells

Abstract To evaluate the property of binding activity of α4β1 integrin in cell–cell interaction, we newly established a cell line, α4mK562, by transfecting cDNA of murine integrin α4 subunit into human erythroleukemic K562 cells. α4mK562 transfectant expressed both murine α4 and human β1 subunit, which generated a functional heterodimer. α4mK562 cells more efficiently bound to murine endothelial cell lines and recombinant human TNFα (rhTNF)-treated human umbilical vein endothelial cells (HUVEC) than the parental K562 cells. These adhesion resulted from the interaction between α4β1 and VCAM-1. Interestingly, treatment with mAb against human β1 (4B4 clone), which has been known as inhibitory mAb, enhanced binding of α4mK562 cells to rhTNF-treated HUVEC but not to murine endothelial cells. This increase in binding induced by 4B4 mAb was completely inhibited by another mAb against human β1 (mAb13), but only partially by anti-α4 mAb (PS/2). The increase in binding induced by 4B4 mAb was also abolished by metabolic inhibitors, indicating that the increased binding is energy dependent. These observations suggest that the binding of 4B4 mAb to the chimeric α4β1 induces an unique outside-in signaling and enhances the specific binding of α4mK562 cells to rhTNF-treated HUVEC.
Survival of Heleomyza borealis (Diptera, Heleomyzidae) larvae down to − 60°C

Heleomyza borealis Boh. (Diptera, Heleomyzidae) overwinters as larvae in Arctic habitats, where they may experience winter temperatures below − 15°C. The larvae freeze at c. − 7°C but in acclimation experiments 80% survived when exposed to − 60°C. Of the larvae exposed to between − 4 and − 15°C, only 3% pupated. However, when cooled to − 20°C this increased to 44%, with 4% emerging as adults. Larvae maintained at 5°C contained low levels of glycerol, sorbitol and trehalose, which did not increase with acclimation to low temperatures. However, levels of fructose increased from 6.1 μg mg−1 fw in control animals to 17 μg mg−1 fw when exposed to − 2°C for 1 week. Larval body water (2.2 ± 0.1 g/g dw, mean ± SD, n = 100) and lipid content (0.22 ± 0.002 g/g fw, mean ± SE) showed no significant change during acclimation to low temperatures. Larvae maintained at a constant 5°C survived for over 18 months with little loss of body mass (from 7.5 ± 1.2 to 7.0 ± 1.2 mg fw, mean ± SD, n = 20), but none pupated. Heleomyza borealis larvae appear to feed and grow until they reach a body mass of about 7.5 mg and then become dormant. They remain in this state until they experience a low temperature stimulus (< − 15°C) followed by a warm period (≈ 5°C). This ensures that the larvae pupate and adults emerge in early summer, allowing the maximum growing period before the following winter. Heleomyza borealis are adapted to survive long winters in a dormant larval state. They have a low metabolic rate, can conserve body water even at subzero temperatures but do not synthesize large quantities of cryoprotectants.
Meat yield and subjective muscle scores in medium weight steers

Summary. The association between visually assessed muscle scores on live steers and their carcasses, eye muscle area, and the yield of saleable and lean meat was determined on 156 steers of mixed breeds (mean carcass weight 282 kg, mean P8 fat depth 13 mm). The contribution of subcutaneous and intermuscular fat to differences in saleable meat yield was also investigated. There was a negative correlation between P8 fat depth and both live (I. = -0.21) and carcass muscle score (r. = -0.31); therefore, the assessors were not scoring fatter steers as having better shape. The correlation between live and carcass muscle scores was 0.79. The correlation between carcass muscle score and eye muscle area was 0.58. When live muscle score, carcass muscle score, or eye muscle area was included in regression models already containing weight and fat depth, there was a significant (P<0.001) increase in the amount of variation in saleable and lean meat yield explained by the models. At the same liveweight and fat depth, a change in live muscle score from C (moderately muscled) to B (well muscled) was accompanied by an increase of 1.7% in saleable meat and 2.2% in lean meat, when these were expressed as a percentage of carcass weight. The equivalent change in carcass muscle score in carcasses of the same weight and fat depth was accompanied by an increase of 1.9% in saleable meat and 2.4% in lean meat. The increased weight of saleable meat was not due to an increase in the dissected fat content of the meat. Weight of subcutaneous fat decreased as muscle score increased (P<0.01). There was no significant association between the amount of intermuscular fat and either live or carcass muscle score (1. = -0.075 and -0.18, respectively).
Toxoplasmose em primatas neotropicais: estudo retrospectivo de sete casos

Toxoplasmosis is considered to be a fatal parasitic disease in New World primates. The objective of this report was to describe, through a retrospective study, the toxoplasmosis cases in New World primates. From 1999 to 2009 eighty-six anatomopathological exams was performed in primates and toxoplasmosis was the most common disease (7/86). One case occurred in Black-Tufted-Marmoset (Callithrix penicillata) and six in Brown-Howler monkeys (Alouatta guariba). Two monkeys were found death and five died within few days. The most common clinical signs were apathy and anorexia (5/7), abdominal distension (4/7) and fever (3/7). The main gross lesions were splenomegaly (4/7), hemorrhage in digestory system, lymph nodes and urinary bladder (4/7), reddish lungs (3/7) and hepatomegaly (2/7). Histopathological findings were necrotizing hepatitis (7/7), splenitis (3/7), myocarditis (2/7), enteritis (2/7), lymphadenitis (1/7) and sialitis (1/7), and interstitial pneumonia (4/7). In the liver, lungs, spleen, heart, lymph nodes and salivary gland there were tachyzoites of Toxoplasma gondii that also detected by immunohistochemistry against T. gondii in liver, spleen and lungs (5/7). Toxoplasmosis can cause high mortality in New World primate colonies and can be a threat to preservation of those species in captivity. Therefore, preventive measures should be taken to avoid the contamination of those animals.
Abstract

Anal furunculosis and colitis in dogs, Jamieson, P. M. , Simpson, J. W. , Kirby, B. M. & Else, R. W. (2002) Association between anal furunculosis and colitis in the dog: preliminary observations. Journal ofSmallAnimal Practice 43, 109-114
Government Regulation and the Quality of Healthcare

This paper investigates the effect of a regulation mandating a minimum nurse-staffing level on the quality of healthcare in nursing homes. To comply with the regulation, firms increase employment of nurses in proportion to the gap between their initial staffing level and the legislated minimum threshold. If higher nurse staffing causes better quality, then the changes in quality outcomes should mirror these changes. Despite inducing increases in nurse aide hours of 10 percent on average and up to 30 percent for some firms, I find no impact of the regulation on patient outcomes or overall facility quality.
Demographic responses of Antechinus stuartii (Marsupialia) to supplementary food

This study investigates the effects of supplementary feeding on populations of Antechinus stuartii, an insectivorous, semi-arboreal species of dasyurid marsupial. Animals were live-trapped, marked and released in three study areas in forest near Canberra, from September 1980 to November 1981. Supplementary food was supplied above ground in trees in one study area from January to November 1981, and in the second study area from January to May 1981, while the third study area was left unmanipulated as a control. The supplemented populations increased in numbers, mean body weights and survival, and showed decreased movements between traps and smaller overlaps in home ranges. Discontinuation of food in the second study area in May 1981 produced reciprocal shifts in these parameters. Reproduction, home-range area, mean head-body length, use of the terrestrial and arboreal parts of the habitat were largely unaffected by provision of supplementary food. In contrast to rodents, where fed populations usually increase rapidly due to immigration or increased reproduction, the supplemented populations of A. stuartii responded relatively slowly via increased survival of young. Population responses were probably retarded at the beginning of the experiments in summer due to the abundance of natural invertebrate prey, but became more obvious in winter when natural food was scarce. The added food probably contributed directly to increased numbers, survival and body weights, but may also have enhanced these parameters indirectly by allowing foraging animals to space out and avoid intraspecific intolerant contacts. These responses in A. stuartii suggest strongly that populations are limited by the food supply.