bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vasopressin and Intrarenal Blood Flow Distribution
Authors: Aukland Knut 
Published: July 2014

AbstractIt has been suggested that the rise in urine osmolality produced by antidiuretic hormone is wholly or partly due to juxtamedullary vasoconstriction with reduction of medullary blood flow. This hypothesis was tested in 10 hydrated dogs in Nembutal anesthesia. Effective renal blood flow (ERBF) was estimated by p‐aminohippurate clearance, and medullary blood flow by hydrogen gas clearance from the outer medulla measured polarographically with needle‐shaped platinum electrodes. I.v. infusion of Pitressin, 3—120 mU/hr per kg body weight, or synthetic lysin‐vasopressin, 2.5—30 mU/hr per kg, on average increased urine osmolality from 100 to 500 mOsm/kg. Arterial blood pressure rose slightly with doses higher than 20—30 mU/hr per kg. ERBF and outer medullary hydrogen clearance was not changed by 1—2 hrs vasopressin infusion, and also remained unchanged during return to water diuresis after stopping vasopressin. The experiments thus showed no effect of vasopressin either on total renal perfusion or on medullary blood flow.
Mechanical and Electrical Responses to Single Shocks in Developing Gat Leg Muscles Following Tetanization
Authors: Nyström Bo 
Published: July 2014

AbstractThe effects of 9 sec tetanizations of varying frequencies on isometric twitch and electrical responses were studied in the gastrocnemius, soleus and extensor carpi radialis longus (ECRL) muscles of kittens of varying ages and adult cats. Nembutal® anaesthesia was used. In newborn kittens, no or only slight post‐tetanic twitch potentiation (PTP) was recorded in the gastrocnemius muscle, but a PTP of 80—90 % in the soleus. With time, twitch potentiation increased in the gastrocnemius and decreased in the soleus. In the latter muscle of adult cats, PTP was obtained only after high‐frequency tetanization (250—450 c/sec). This PTP proved to be due to repetitive activity, and of different magnitude in Nembutal‐ and chloralose‐anaesthetized animals. Changes in contraction and half relaxation time and in tension rise of the twitches occurred post‐tetanically. At all ages, post‐tetanic muscle action potentials, whether accompanying potentiated twitches or not, showed no consistent change in size, varying ±10 % from the pre‐tetanic values. In young kittens, post‐tetanic potentials were slightly delayed. In the gastrocnemius and ECRL of adult cats, there was a short‐lasting increase—as compared to the duration of twitch potentiation—in duration of the electrical response, but no change in latency. It is concluded that, in Nembutal‐anaesthetized animals, repetitive firing accounts for PTP in the adult cat soleus muscle. The PTP in the soleus of young kittens and in the gastrocnemius and ECRL of the adult animals is, on the other hand, due either to a change within the contractile mechanism of the muscle fibres, or to a recruitment of muscle fibres.
Effect of Potassium‐Magnesium‐Aspartate on the Capacity for Prolonged Exercise in Man
Authors: Ahlborg Björn , Ekelund Lars‐Göran , Nilsson Carl‐Gustaf 
Published: July 2014

AbstractThe effect of potassium‐magnesium‐aspartate on the capacity for continuous prolonged standardized physical exercise (exercise times about 90 min) has been investigated in 6 normal young men. After administration of potassium‐magnesium‐aspartate the capacity for prolonged exercise increased about 50 per cent. Possible mechanisms behind this effect are discussed.
Localization of Gastrin Activity in the Gastric Antrum1
Authors: Broomé A. , Fyrö B. , Olbe L. 
Published: July 2014

AbstractGastrin activity was determined in sections, cut parallel to the surface, of the antral mucosa and submucosa of cats and dogs and in the aboral corpus mucosa of dogs and man. The maximal gastrin activity in the antrum was found in the basal 2/3 of the gland crypt region of the mucosa. The superficial 1/3 of the antral mucosa of the cat contained no gastrin activity, whereas in the dog traces of activity were found in this part of the mucosa. Extracts from the submucosa of the cat antrum contained no gastrin activity, but in the submucosa of 1 dog out of 3 low activity was found. The results suggest that the gastrin cells are localized predominantly in the region of the middle and basal parts of the gland crypts of the antral mucosa in the dog and cat. In the corpus mucosa immediately oral to the visualized antrum‐corpus boundary, no gastrin activity was found in 3 dogs and activity was present in only 4 of 14 doudenal ulcer patients. Thus the gastrin cells do not seem to be present in the corpus mucosa of dog or man, but the occasional finding of gastrin activity in the most aboral part of the acid secreting gastric mucosa of man speaks in favour of a dentate, or sometimes notchy, antrum‐corpus boundary.
Gastrin‐Like Activity in Different Parts of the Gastro‐Intestinal Tract of the Cat
Authors: Emås Sverre , Fyrö Bengt 
Published: July 2014

AbstractMucosal specimens from different parts of the gastro‐intestinal tract of cats were extracted for gastrin according to the method of Komarov. Extracts were also prepared from the mucosa of the antrum and proximal duodenum according to a modification of a method of Gregory and Tracy. The extracts were assayed for gastrin activity on nonanesthetized gastric fistula cats. Gastrin‐like activity was found in the mucosa of the antrum and the proximal duodenum using either method of extraction. Gastrin‐like activity was also found in most extracts from the cardiac region of the stomach. The gastrin‐like activity of the extracts from the cardiac region and the proximal duodenum was 5–10 per cent of the antral activity. No gastrin‐like activity was detected in the acid secreting part of the stomach, in the middle and distal parts of the duodenum, in the jejunum, colon or pancreas.
Elasticity and Tensile Strength of the Anterior Cruciate Ligament in Rabbits as Influenced by Training
Authors: Viidik A. 
Published: July 2014

AbstractThe effects of training in a running machine were studied on nineteen rabbits while seventeen of the same stock were used as controls. The rabbits were at the start of the training period about three months old and the mechanical tests were performed forty weeks later. Tensile strength and elasticity tests were performed on anterior cruciate ligaments from their knee joints utilizing the femur and the tibia as fixture points. It is concluded that the weakest point in the system of tibialigamentum cruciatum anterius—femur is one of the bony attachments and most often the tibial one. The energy required to break the system is increased by training and so are the maximun load and the deformation at that point. All these phenomena can be accounted for by strengthening of the bones. The elasticity tests, however, show a larger load‐relaxation phenomenon in the ligaments from the trained animals and it occurs with a higher speed, indicating altered viscous properties. It is concluded that these changes must be qualitative changes occurring in the ligamentous tissue.
Influence of Gonadotrophins on the Respiration of Isolated Cells from the Prepubertal Rat Ovary
Authors: Hamberger Lars A. 
Published: July 2014

AbstractA detailed description for separation by microdissection of various types of cells from prepubertal rat ovaries is reported. The rate of oxidation of succinate under influence of gonadotrophins was measured in the various cell samples applying the micro‐diver technique (Zeuthen 1953). The dry weight of the cell samples was determined by a direct x‐ray absorption technique (Rosengren 1959). The gonadotrophins were injected to the animals either 2 hrs before removal of the ovaries, or added directly to the incubation medium. In isolated granulosa cells the rate of oxygen uptake was significantly enhanced by LH administered in vitro or in vivo, while FSH had no stimulatory effects. The theca cells showed the opposite pattern i.e. a stimulatory effect on the rate of oxygen uptake by FSH both in vitro and in vivo, but no stimulatory effect by LH. The oxygen uptake of interstitial cells was clearly stimulated by FSH in vivo and probably also by in vitro administration of this hormone. LH showed no tendency to increase the rate of oxygen uptake by these cells. The results support the theory that FSH and LH selectively stimulate various types of ovarian cells.
HPV vaccine stimulates cytotoxic activity of killer dendritic cells and natural killer cells against HPV‐positive tumour cells
Authors: Van den Bergh Johan M. J. , Guerti Khadija , Willemen Yannick , Lion Eva , Cools Nathalie , Goossens Herman , Vorsters Alex , Van Tendeloo Viggo F. I. , Anguille Sébastien , Van Damme Pierre , Smits Evelien L. J. M. 
Published: July 2014

AbstractCervarix™ is approved as a preventive vaccine against infection with the human papillomavirus (HPV) strains 16 and 18, which are causally related to the development of cervical cancer. We are the first to investigate in vitro the effects of this HPV vaccine on interleukin (IL)‐15 dendritic cells (DC) as proxy of a naturally occurring subset of blood DC, and natural killer (NK) cells, two innate immune cell types that play an important role in antitumour immunity. Our results show that exposure of IL‐15 DC to the HPV vaccine results in increased expression of phenotypic maturation markers, pro‐inflammatory cytokine production and cytotoxic activity against HPV‐positive tumour cells. These effects are mediated by the vaccine adjuvant, partly through Toll‐like receptor 4 activation. Next, we demonstrate that vaccine‐exposed IL‐15 DC in turn induce phenotypic activation of NK cells, resulting in a synergistic cytotoxic action against HPV‐infected tumour cells. Our study thus identifies a novel mode of action of the HPV vaccine in boosting innate immunity, including killing of HPV‐infected cells by DC and NK cells.
Global biogeography of the ectomycorrhizal /sebacina lineage (Fungi, Sebacinales) as revealed from comparative phylogenetic analyses
Authors: Tedersoo Leho , Bahram Mohammad , Ryberg Martin , Otsing Eveli , Kõljalg Urmas , Abarenkov Kessy 
Published: July 2014

AbstractCompared with plants and animals, large‐scale biogeographic patterns of microbes including fungi are poorly understood. By the use of a comparative phylogenetic approach and ancestral state reconstructions, we addressed the global biogeography, rate of evolution and evolutionary origin of the widely distributed ectomycorrhizal (EcM) /sebacina lineage that forms a large proportion of the Sebacinales order. We downloaded all publicly available internal transcribed spacer (ITS) sequences and metadata and supplemented sequence information from three genes to construct dated phylogenies and test biogeographic hypotheses. The /sebacina lineage evolved 45–57 Myr ago that groups it with relatively young EcM taxa in other studies. The most parsimonious origin for /sebacina is inferred to be North American temperate coniferous forests. Among biogeographic traits, region and biome exhibited stronger phylogenetic signal than host family. Consistent with the resource availability (environmental energy) hypothesis, the ITS region is evolving at a faster rate in tropical than nontropical regions. Most biogeographic regions exhibited substantial phylogenetic clustering suggesting a strong impact of dispersal limitation over a large geographic scale. In northern Holarctic regions, however, phylogenetic distances and phylogenetic grouping of isolates indicate multiple recent dispersal events.
Kaldor's 1970 Regional Growth Model Revisited
Authors: Thirlwall A. P. 
Published: July 2014

AbstractKaldor's 1970 paper ‘The Case for Regional Policies’ was republished in the 60th anniversary volume of the Scottish Journal of Political Economy. This article reflects on the model after more than 40 years, and argues that although it has been criticized for its deterministic nature, it has lost none of its relevance. It predates the ideas of so‐called ‘new’ growth theory, and the new economic geography of Krugman, and provides at least a partial explanation of why growth rates and levels of per capita income between regions and between countries can continue to persist and even widen in contrast to the predictions of orthodox equilibrium theory.
Target Enzyme Mutations Confer Differential Echinocandin Susceptibilities in Candida kefyr
Authors: Staab Janet F. , Neofytos Dionysios , Rhee Peter , Jiménez-Ortigosa Cristina , Zhang Sean X. , Perlin David S. , Marr Kieren A. 
Published: July 2014

ABSTRACT

Candida kefyr
is an increasingly reported pathogen in patients with hematologic malignancies. We studied a series of bloodstream isolates that exhibited reduced echinocandin susceptibilities (RES). Clinical and surveillance isolates were tested for susceptibilities to all three echinocandins, and those isolates displaying RES to one or more echinocandins were selected for molecular and biochemical studies. The isolates were analyzed for genetic similarities, and a subset was analyzed for mutations in the echinocandin target gene
FKS1
and glucan synthase echinocandin sensitivities using biochemical methods. The molecular typing did not indicate strong genetic relatedness among the isolates except for a series of strains recovered from a single patient. Two unrelated isolates with RES had previously uncharacterized
FKS1
mutations: R647G and deletion of amino acid 641 (F641Δ). Biochemical analysis of the semipurified R647G glucan synthase generated differential echinocandin sensitivity (resistance to micafungin only), while the deletion of F641 resulted in a glucan synthase highly insensitive to all three echinocandins. The consecutive isolates from a single patient with RES all harbored the common S645P mutation, which conferred resistance to all three echinocandins. The MIC values paralleled the glucan synthase inhibition kinetic data, although the S645P isolates displayed relatively higher susceptibility to caspofungin (2 μg/ml) than the other two echinocandins (>8 μg/ml). These findings highlight novel and common
FKS1
mutations in
C. kefyr
isolates. The observation of differential susceptibilities to echinocandins may provide important mechanistic insights for echinocandin antifungals.
Improving the Role and Contribution of Pharmacokinetic Analyses in Antimalarial Drug Clinical Trials
Authors: Kay Katherine , Hodel Eva Maria , Hastings Ian M. 
Published: July 2014

ABSTRACT
It is now World Health Organization (WHO) policy that drug concentrations on day 7 be measured as part of routine assessment in antimalarial drug efficacy trials. The rationale is that this single pharmacological measure serves as a simple and practical predictor of treatment outcome for antimalarial drugs with long half-lives. Herein we review theoretical data and field studies and conclude that the day 7 drug concentration (d7c) actually appears to be a poor predictor of therapeutic outcome. This poor predictive capability combined with the fact that many routine antimalarial trials will have few or no failures means that there appears to be little justification for this WHO recommendation. Pharmacological studies have a huge potential to improve antimalarial dosing, and we propose study designs that use more-focused, sophisticated, and cost-effective ways of generating these data than the mass collection of single d7c concentrations.
Coinfection with an Intestinal Helminth Impairs Host Innate Immunity against Salmonella enterica Serovar Typhimurium and Exacerbates Intestinal Inflammation in Mice
Authors: Su Libo , Su Chien-wen , Qi Yujuan , Yang Guilian , Zhang Mei , Cherayil Bobby J. , Zhang Xichen , Shi Hai Ning 
Published: July 2014

ABSTRACT

Salmonella enterica
serovar Typhimurium is a Gram-negative food-borne pathogen that is a major cause of acute gastroenteritis in humans. The ability of the host to control such bacterial pathogens may be influenced by host immune status and by concurrent infections. Helminth parasites are of particular interest in this context because of their ability to modulate host immune responses and because their geographic distribution coincides with those parts of the world where infectious gastroenteritis is most problematic. To test the hypothesis that helminth infection may negatively regulate host mucosal innate immunity against bacterial enteropathogens, a murine coinfection model was established by using the intestinal nematode
Heligmosomoides polygyrus
and
S
. Typhimurium. We found that mice coinfected with
S
. Typhimurium and
H. polygyrus
developed more severe intestinal inflammation than animals infected with
S
. Typhimurium alone. The enhanced susceptibility to
Salmonella
-induced intestinal injury in coinfected mice was found to be associated with diminished neutrophil recruitment to the site of bacterial infection that correlated with decreased expression of the chemoattractants CXCL2/macrophage inflammatory protein 2 (MIP-2) and CXCL1/keratinocyte-derived chemokine (KC), poor control of bacterial replication, and exacerbated intestinal inflammation. The mechanism of helminth-induced inhibition of MIP-2 and KC expression involved interleukin-10 (IL-10) and, to a lesser extent, IL-4 and IL-13. Ly6G antibody-mediated depletion of neutrophils reproduced the adverse effects of
H. polygyrus
on
Salmonella
infection. Our results suggest that impaired neutrophil recruitment is an important contributor to the enhanced severity of
Salmonella
enterocolitis associated with helminth coinfection.
Massive Diversification in Aging Colonies of Escherichia coli
Authors: Saint-Ruf Claude , Garfa-Traoré Meriem , Collin Valérie , Cordier Corinne , Franceschi Christine , Matic Ivan 
Published: July 2014

ABSTRACT

The evolutionary success of bacteria depends greatly on their capacity to continually generate phenotypic diversity. Structured environments are particularly favorable for diversification because of attenuated clonal interference, which renders selective sweeps nearly impossible and enhances opportunities for adaptive radiation. We examined at the microscale level the emergence and the spatial and temporal dynamics of phenotypic diversity and their underlying causes in
Escherichia coli
colonies. An important dynamic heterogeneity in the growth, metabolic activity, morphology, gene expression patterns, stress response induction, and death patterns among cells within colonies was observed. Genetic analysis indicated that the phenotypic variation resulted mostly from mutations and that indole production, oxidative stress, and the RpoS-regulated general stress response played an important role in the generation of diversity. We observed the emergence and persistence of phenotypic variants within single colonies that exhibited variable fitness compared to the parental strain. Some variants showed improved capacity to produce biofilms, whereas others were able to use different nutrients or to tolerate antibiotics or oxidative stress. Taken together, our data show that bacterial colonies provide an ecological opportunity for the generation and maintenance of vast phenotypic diversity, which may increase the probability of population survival in unpredictable environments.
Agrobacterium tumefaciens ExoR Controls Acid Response Genes and Impacts Exopolysaccharide Synthesis, Horizontal Gene Transfer, and Virulence Gene Expression
Authors: Heckel Brynn C. , Tomlinson Amelia D. , Morton Elise R. , Choi Jeong-Hyeon , Fuqua Clay 
Published: July 2014

ABSTRACT

Agrobacterium tumefaciens
is a facultative plant pathogen and the causative agent of crown gall disease. The initial stage of infection involves attachment to plant tissues, and subsequently, biofilms may form at these sites. This study focuses on the periplasmic ExoR regulator, which was identified based on the severe biofilm deficiency of
A. tumefaciens
exoR
mutants. Genome-wide expression analysis was performed to elucidate the complete ExoR regulon. Overproduction of the exopolysaccharide succinoglycan is a dramatic phenotype of
exoR
mutants. Comparative expression analyses revealed that the core ExoR regulon is unaffected by succinoglycan synthesis. Several findings are consistent with previous observations: genes involved in succinoglycan biosynthesis, motility, and type VI secretion are differentially expressed in the Δ
exoR
mutant. In addition, these studies revealed new functional categories regulated by ExoR, including genes related to virulence, conjugation of the pAtC58 megaplasmid, ABC transporters, and cell envelope architecture. To address how ExoR exerts a broad impact on gene expression from its periplasmic location, a genetic screen was performed to isolate suppressor mutants that mitigate the
exoR
motility phenotype and identify downstream components of the ExoR regulatory pathway. This suppression analysis identified the acid-sensing two-component system ChvG-ChvI, and the suppressor mutant phenotypes suggest that all or most of the characteristic
exoR
properties are mediated through ChvG-ChvI. Subsequent analysis indicates that
exoR
mutants are simulating a response to acidic conditions, even in neutral media. This work expands the model for ExoR regulation in
A. tumefaciens
and underscores the global role that this regulator plays on gene expression.
The Two-Component Regulators GacS and GacA Positively Regulate a Nonfluorescent Siderophore through the Gac/Rsm Signaling Cascade in High-Siderophore-Yielding Pseudomonas sp. Strain HYS
Authors: Yu Xinyan , Chen Min , Jiang Zhen , Hu Yi , Xie Zhixiong 
Published: July 2014

ABSTRACT

Siderophores, which are produced to overcome iron deficiency, are believed to be closely related to the adaptability of bacteria. The high-siderophore-yielding
Pseudomonas
sp. strain HYS simultaneously secretes the fluorescent siderophore pyoverdine and another nonfluorescent siderophore that is a major contributor to the high siderophore yield. Transposon mutagenesis revealed siderophore-related genes, including the two-component regulators GacS/GacA and a special cluster containing four open reading frames (the
nfs
cluster). Deletion mutations of these genes abolished nonfluorescent-siderophore production, and expression of the
nfs
cluster depended on
gacA
, indicating that
gacS-gacA
may control the nonfluorescent siderophore through regulation of the
nfs
cluster. Furthermore, regulation of the nonfluorescent siderophore by GacS/GacA involved the Gac/Rsm pathway. In contrast, inactivation of GacS/GacA led to upregulation of the fluorescent pyoverdine. The two siderophores were secreted under different iron conditions, probably because of differential effects of GacS/GacA. The global GacS/GacA regulatory system may control iron uptake by modulating siderophore production and may enable bacteria to adapt to changing iron environments.