bluuebunny/crossref_metadata_2025 huggingface dataset:
Superior time perception for lower musical pitch explains why bass-ranged instruments lay down musical rhythms
Authors: Hove Michael J. , Marie Céline , Bruce Ian C. , Trainor Laurel J.
Published: July 2014

Significance

To what extent are musical conventions determined by evolutionarily-shaped human physiology? Across cultures, polyphonic music most often conveys melody in higher-pitched sounds and rhythm in lower-pitched sounds. Here, we show that, when two streams of tones are presented simultaneously, the brain better detects timing deviations in the lower-pitched than in the higher-pitched stream and that tapping synchronization to the tones is more influenced by the lower-pitched stream. Furthermore, our modeling reveals that, with simultaneous sounds, superior encoding of timing for lower sounds and of pitch for higher sounds arises early in the auditory pathway in the cochlea of the inner ear. Thus, these musical conventions likely arise from very basic auditory physiology.
Cyclophilin A catalyzes proline isomerization by an electrostatic handle mechanism
Authors: Camilloni Carlo , Sahakyan Aleksandr B. , Holliday Michael J. , Isern Nancy G. , Zhang Fengli , Eisenmesser Elan Z. , Vendruscolo Michele
Published: July 2014

Significance

One of the most widespread molecular switches in biochemical pathways is based on the isomerization of the amino acid proline, a process that normally is facilitated by enzymes known as “proline isomerases.” We show that cyclophilin A, one of the most common proline isomerases, acts by a simple mechanism, which we describe as an “electrostatic handle.” In this mechanism, the enzyme creates an electrostatic environment in its catalytic site that rotates a peptide bond in the substrate by pulling the electric dipole associated with the carbonyl group preceding the peptide bond itself. Our results thus identify a specific mechanism by which electrostatics is exploited in enzyme catalysis.
Structures of benzylsuccinate synthase elucidate roles of accessory subunits in glycyl radical enzyme activation and activity
Authors: Funk Michael A. , Judd Evan T. , Marsh E. Neil G. , Elliott Sean J. , Drennan Catherine L.
Published: July 2014

Significance

Glycyl radical enzymes perform many chemical transformations that form the bedrock of microbial anaerobic metabolism. The structure of benzylsuccinate synthase reveals the architecture of an enzyme capable of removing aromatic hydrocarbons from polluted environments. These structures also illustrate a strategy for controlling the generation and utilization of radicals by glycyl radical enzymes through the use of accessory subunits.
Developmental propagation of V(D)J recombination-associated DNA breaks and translocations in mature B cells via dicentric chromosomes
Authors: Hu Jiazhi , Tepsuporn Suprawee , Meyers Robin M. , Gostissa Monica , Alt Frederick W.
Published: July 2014

Significance

Antibody production depends on a cut-and-paste genomic rearrangement termed “V(D)J recombination” that takes place during early B-lymphocyte development. Mistakes in V(D)J recombination can lead to chromosomal translocations that activate oncogenes. Such mistakes usually lead to immature B-cell cancers. However, in the absence of the ATM kinase, mice can develop mature B-cell tumors with translocations resulting from V(D)J recombination-associated breaks. Normally persistent chromosome breaks activate cellular checkpoints that eliminate cells harboring such dangerous lesions. The current studies reveal that, in the absence of ATM, V(D)J recombination-generated breaks are cycled into aberrant chromosomes, termed “dicentrics,” that avoid checkpoints and are propagated through development, generating new breaks and translocations in mature B cells.
ETO family protein Mtg16 regulates the balance of dendritic cell subsets by repressing Id2
Authors: Ghosh Hiyaa S. , Ceribelli Michele , Matos Ines , Lazarovici Allan , Bussemaker Harmen J. , Lasorella Anna , Hiebert Scott W. , Liu Kang , Staudt Louis M. , Reizis Boris
Published: July 2014

Dendritic cells (DCs) comprise two major subsets, the interferon (IFN)-producing plasmacytoid DCs (pDCs) and antigen-presenting classical DCs (cDCs). The development of pDCs is promoted by E protein transcription factor E2-2, whereas E protein antagonist Id2 is specifically absent from pDCs. Conversely, Id2 is prominently expressed in cDCs and promotes CD8+ cDC development. The mechanisms that control the balance between E and Id proteins during DC subset specification remain unknown. We found that the loss of Mtg16, a transcriptional cofactor of the ETO protein family, profoundly impaired pDC development and pDC-dependent IFN response. The residual Mtg16-deficient pDCs showed aberrant phenotype, including the expression of myeloid marker CD11b. Conversely, the development of cDC progenitors (pre-DCs) and of CD8+ cDCs was enhanced. Genome-wide expression and DNA-binding analysis identified Id2 as a direct target of Mtg16. Mtg16-deficient cDC progenitors and pDCs showed aberrant induction of Id2, and the deletion of Id2 facilitated the impaired development of Mtg16-deficient pDCs. Thus, Mtg16 promotes pDC differentiation and restricts cDC development in part by repressing Id2, revealing a cell-intrinsic mechanism that controls subset balance during DC development.
On the lack of density of Lipschitz mappings in Sobolev spaces with Heisenberg target
Authors: DeJarnette Noel , Hajłasz Piotr , Lukyanenko Anton , Tyson Jeremy
Published: July 2014

We study the question: When are Lipschitz mappings dense in the Sobolev space

W

1
,
p

(
M
,

H

n

)

W^{1,p}(M,\mathbb {H}^n)

? Here

M
M

denotes a compact Riemannian manifold with or without boundary, while

H

n

\mathbb {H}^n

denotes the

n
n

th Heisenberg group equipped with a sub-Riemannian metric. We show that Lipschitz maps are dense in

W

1
,
p

(
M
,

H

n

)

W^{1,p}(M,\mathbb {H}^n)

for all

1
≤
p
>
∞

1\le p>\infty

if

dim
⁡
M
≤
n

\dim M \le n

, but that Lipschitz maps are not dense in

W

1
,
p

(
M
,

H

n

)

W^{1,p}(M,\mathbb {H}^n)

if

dim
⁡
M
≥
n
+
1

\dim M \ge n+1

and

n
≤
p
>
n
+
1

n\le p>n+1

. The proofs rely on the construction of smooth horizontal embeddings of the sphere

S

n

\mathbb {S}^n

into

H

n

\mathbb {H}^n

. We provide two such constructions, one arising from complex hyperbolic geometry and the other arising from symplectic geometry. The nondensity assertion can be interpreted as nontriviality of the

n
n

th Lipschitz homotopy group of

H

n

\mathbb {H}^n

. We initiate a study of Lipschitz homotopy groups for sub-Riemannian spaces.
Recent applications of boxed molecular dynamics: a simple multiscale technique for atomistic simulations
Authors: Booth Jonathan , Vazquez Saulo , Martinez-Nunez Emilio , Marks Alison , Rodgers Jeff , Glowacki David R. , Shalashilin Dmitrii V.
Published: July 2014

In this paper, we briefly review the boxed molecular dynamics (BXD) method which allows analysis of thermodynamics and kinetics in complicated molecular systems. BXD is a multiscale technique, in which thermodynamics and long-time dynamics are recovered from a set of short-time simulations. In this paper, we review previous applications of BXD to peptide cyclization, solution phase organic reaction dynamics and desorption of ions from self-assembled monolayers (SAMs). We also report preliminary results of simulations of diamond etching mechanisms and protein unfolding in atomic force microscopy experiments. The latter demonstrate a correlation between the protein's structural motifs and its potential of mean force. Simulations of these processes by standard molecular dynamics (MD) is typically not possible, because the experimental time scales are very long. However, BXD yields well-converged and physically meaningful results. Compared with other methods of accelerated MD, our BXD approach is very simple; it is easy to implement, and it provides an integrated approach for simultaneously obtaining both thermodynamics and kinetics. It also provides a strategy for obtaining statistically meaningful dynamical results in regions of configuration space that standard MD approaches would visit only very rarely.
MALDI-TOF: A useful tool for laboratory identification of uncommon glucose non-fermenting Gram-negative bacteria associated with cystic fibrosis
Authors: Homem de Mello de Souza Helena Aguilar Peres , Dalla-Costa Libera Maria , Vicenzi Fernando José , Camargo de Souza Dilair , Riedi Carlos Antônio , Filho Nelson Augusto Rosario , Pilonetto Marcelo
Published: July 2014

The predisposition of patients with cystic fibrosis (CF) for recurrent pulmonary infections can result in poor prognosis of the disease. Although the clinical significance in CF of micro-organisms, such as Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa, is well established, the implication of uncommon glucose non-fermenting Gram-negative bacilli (UGNF-GNB) in respiratory samples from CF patients is still unclear. Because of limitations of traditional methods used in most clinical laboratories, the accurate identification of these microbes is a challenge. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) is an alternative tool for efficient identification of bacteria. This was a retrospective study to evaluate different identification methods in a collection of UGNF-GNB isolated from children with CF during a period of three years. The performance of MALDI-TOF was compared to that of 16S rDNA gene sequencing and to a conventional and automated phenotypic identification. The discriminatory power of MALDI-TOF (75.0 % agreement) was superior to automated techniques (67.1 % agreement) and to conventional phenotypical identification (50.0 % agreement). MALDI-TOF also demonstrated high accuracy in identifying Stenotrophomonas maltophilia, Achromobacter xylosoxidans and Chryseobacterium indologenes, but had limited utility in identifying Pandoraea spp. and some species of Acinetobacter and Chryseobacterium (other than C. indologenes). Although MALDI-TOF identified only 75 % of the isolates in comparison with 16S rDNA gene sequencing, the prompt identification and high discriminatory power exhibited by MALDI-TOF make it a useful tool for the characterization of micro-organisms that are difficult to identify using routine methods.
Collecting Data to Determine the Ca2+-Binding Properties of DM-Nitrophen and Proteins
Authors: Faas Guido C. , Mody Istvan
Published: July 2014

Conventional techniques used to measure Ca2+ binding are too slow to determine accurately the fast binding kinetics of most molecules such as Ca2+-binding proteins (CBPs). We have developed an ultra-fast in vitro technique for measuring the Ca2+-binding properties of CBPs following flash photolysis of caged Ca2+. Although the details of the setup, the mathematics, and the analysis involved in this technique have been published elsewhere, many of the practical details regarding the actual measurements have, until now, only been described minimally. Here, we present a protocol to gather the data necessary to determine the kinetic properties of a caged-Ca2+ compound and a CBP.
Assaying Caspase Activity In Vitro
Authors: McStay Gavin P. , Green Douglas R.
Published: July 2014

Monitoring the activity of a caspase, either as an isolated protein or in a complex mixture (e.g., a cytosolic extract), can be achieved by measuring substrate cleavage. Chromogenic or fluorogenic substrates are available for many caspases. These substrates usually consist of the four-amino-acid motif that is optimal for each caspase and a moiety that, when cleaved, generates either a chromophore or a fluorophore that can be detected using spectrophotometric or fluorimetric means. In this protocol, we describe how to use these substrates to monitor caspase activity in samples containing active caspases (e.g., apoptotic cells). Caspase inhibitors, which contain a moiety that covalently attaches to the active site of the caspase, can be used in these assays. These assays will ascertain whether caspases are involved in a specific process (e.g., whether caspases are activated after an apoptotic stimulus) and are particularly informative if a purified caspase is used. However, the substrates and inhibitors are not specific for a particular caspase in an environment containing multiple caspases. So, if cytosolic or apoptotic cell extracts are used in these assays, additional experiments must be performed to identify exactly which caspases are involved.
Presynaptic Calcium Measurements Using Bulk Loading of Acetoxymethyl Indicators
Authors: Brenowitz Stephan D. , Regehr Wade G.
Published: July 2014

We describe a method for labeling presynaptic terminals in mammalian brain slices by focal application of calcium indicators conjugated with acetoxymethyl (AM) esters. A solution of membrane-permeant, AM-conjugated calcium indicator is focally applied to the transverse cerebellar brain slice and allowed to equilibrate throughout the parallel fiber tract. Fibers are then stimulated with an extracellular electrode and fluorescence transients are measured from a location several hundred micrometers from the loading site using a photodiode or photomultiplier tube. Considerations for selecting an appropriate indicator and determining the optimum loading conditions are discussed.
Crisis Management through Network Coordination: Experiences of Swedish Civil Defence Directors
Authors: Wimelius Malin E. , Engberg Jan
Published: July 2014

In this article we explore and analyse Swedish Civil Defence Directors' views on coordination and cooperation in crisis management. The directors work at County Administrative Boards (CABs) which by law are required to coordinate all relevant actors – national agencies, municipal, private and voluntary – by leading their cooperation in extraordinary events. How do CABs manage this, especially against a backdrop of increasing demands on clarity, command, control and explicit goals in crisis management? Through the lens of research on governance we analyse the directors' views and find that although they support horizontal, inter‐organizational network based coordination and cooperation, there is frustration regarding the decision‐making capacities of the CABs, the lack of conflict management mechanisms in networks and resource allocation.
Expression of interleukin‐12 by adipose‐derived mesenchymal stem cells for treatment of lung adenocarcinoma
Authors: Li Xin , Zhang Peng , Liu Xiaozhi , Lv Peng
Published: July 2014

Background

Studies have revealed mesenchymal cells tend to directionally migrate toward tumor cells and inhibit tumor growth. However, there have been rare reports about adipose‐derived mesenchymal stem cells (AMSCs), which achieved stable expression of interleukin (IL)‐12 to inhibit lung adenocarcinoma cell migration and invasion. We aimed to achieve stable expression of IL‐12 in AMSCs through transgenic technology and utilize the paracrine effect of IL‐12 to inhibit lung adenocarcinoma cell migration and invasion.

Methods

Adipose‐derived AMSCs were transduced with lentivirus encoding IL‐12. IL‐12/AMSCs and lung adenocarcinoma A549 cells were co‐cultured using a cylinder column to assess cellular attraction, and expression of Ki67 was detected. Dual‐chamber transwell experiments were used to assess migration and invasiveness of A549 cells exposed to conditioned media from IL‐12/AMSCs.

Results

When A549 cells were co‐cultured with lentivirus vectors (LV)‐IL‐12‐green fluorescent protein (GFP)/AMSCs, the intercellular distance was great (346.44 ± 41.07 μm vs. 201.58 ± 27.96 μm vs. 191.45 ± 24.07 μm) (F = 25.414, P < 0.05); the Ki67‐positive rate was low (59.13 ± 17.21% vs. 92.31 ± 6.11% vs. 94.25 ± 5.27%) (F = 21.426, P < 0.05). When the lower Transwell chamber contained culture medium from LV‐IL‐12‐GFP/AMSCs, the percentage of the invasive A549 cells was low (31.55 ± 6.21% vs. 70.65 ± 10.46% vs. 68.65 ± 9.50%) (F = 27.494, P < 0.05). The percentages of colonized A549 cells that invaded the culture media of LV‐IL‐12‐GFP/AMSCs were low (4.46 ± 1.21 vs. 10.11 ± 2.07 vs. 9.48 ± 1.4) (F = 23.219, P < 0.05).

Conclusions

AMSCs could target lung carcinoma and mediate stable expression of IL‐12, to play a role in tumor treatment.
Homology assessment in parsimony and model‐based analyses: two sides of the same coin
Authors: Assis Leandro C. S.
Published: July 2014

The present paper is mainly concerned with homology assessment through phylogenetic analyses. It raises a fundamental question: What are the epistemological differences between modern parsimony and model‐based analyses in relation to homology assessment and phylogenetic inference? Although these methods usually achieve concordant topological results, they may generate discordant inferences of character evolution from the same datasets. This indicates that method selection has serious implications for evolutionary scenarios and classificatory arrangements. Notwithstanding that parsimony and model‐based approaches use the Hennigian concepts of monophyly and synapomorphy, they employ different epistemological ways of dealing with the monophyly/synapomorphy relationship. Independently of their differences, these analyses should take into account all relevant evidence in support of the phylogenetic inferences. A focus on morphological homologues means that they must be included in data matrices, evaluated as part of the phylogenetic analysis, and cannot be ignored in calculation of the tree(s) length (parsimony), maximum‐likelihood (maximum‐likelihood), and posterior probabilities (Bayes).
Exzidieren oder nicht: Auswirkung von MelaFind auf Biopsie‐Entscheidungen atypischer Läsionen bei deutschen Dermatologen
Authors: Hauschild Axel , Chen Suephy C. , Weichenthal Michael , Blum Andreas , King Hadley C. , Goldsmith Jeff , Scharfstein Daniel , Gutkowicz‐Krusin Dina
Published: July 2014

Zielsetzung

Die Biopsie‐Sensitivität unter Dermatologen in Deutschland gegenüber Melanomen zu bestimmen und zu ermitteln, welchen Einfluss MelaFind® auf ihre Entscheidung hat, Melanome zu biopsieren.

Studiendesign

Randomisierte, zweiarmige Online‐Leserstudie mit Präsentation von Fallinformationen, klinischen/dermatoskopischen Abbildungen pigmentierter Hautläsionen und MelaFind‐Ergebnissen (Studienarm 2).

Methoden

Jeder Teilnehmer wurde aufgefordert, 130 pigmentierte Hautläsionen zu überprüfen. Die Biopsie‐Entscheidungen von Dermatologen ohne MelaFind versus MelaFind und von Dermatologen ohne MelaFind versus Dermatologen mit MelaFind wurden miteinander verglichen.

Ergebnisse

Dermatologen ohne MelaFind zeigten eine durchschnittliche Sensitivität gegenüber Melanomen von 69,5 % und eine durchschnittliche Spezifität von 55,9 %. MelaFind hatte eine höhere Sensitivität als Dermatologen ohne dieses Hilfsmittel (96,9 % vs. 69,5 %, einseitiger Test, p < 0,00001) bei niedrigerer Spezifität (9,2 % vs. 55,9 %, einseitiger Test, p < 0,00001). Dermatologen mit MelaFind zeigten eine höhere Sensitivität als Dermatologen ohne MelaFind (78 % vs. 69,5 %, einseitiger Test, p < 0,00001) und eine geringere Spezifität (45,8 % vs. 55,9 %, einseitiger p < 0,00001). Die Zahl der Dermatologen, die über 90 % der malignen Melanome entdeckten, stieg von 3 von 101 ohne MelaFind auf 22 von 101 mit MelaFind (p = 0,00006) bei weitestgehend unveränderter Spezifität (23 % vs. 21 %, p = 0,99).

Schlussfolgerungen

Die durch MelaFind gewonnenen Informationen können, wenn sie in die Biopsie‐Entscheidung mit einbezogen werden, die Sensitivität verbessern bei nur geringer Beeinflussung der Spezifität.
Television viewing time and risk of incident diabetes mellitus: the English Longitudinal Study of Ageing
Authors: Smith L. , Hamer M.
Published: July 2014

Aim

To investigate the longitudinal association between television viewing time and risk of incident diabetes mellitus in an elderly sample of adults in England.

Methods

Analyses of data from the English Longitudinal Study of Ageing. At baseline (2008), participants reported their television viewing time and physical activity level. Diabetes mellitus was recorded from self‐reported physician diagnosis at 2‐year follow‐up. Associations between television viewing time and combined television viewing time and physical activity level with risk of incident diabetes mellitus at follow‐up were examined using adjusted logistic regression models.

Results

A total of 5964 participants (mean ± sd age 65 ± 9 years at baseline, 44% male) were included in the analyses. There was an association between baseline television viewing time and risk of incident diabetes mellitus at 2‐year follow‐up (≥ 6 h/day compared with <2 h/day; odds ratio 4.27, 95% CI 1.69, 10.77), although the association was attenuated to the null in final adjusted models that included BMI. Participants who were inactive/had high television viewing time at baseline were almost twice as likely to have diabetes mellitus at 2‐year follow‐up than those who were active/had low television viewing time (fully adjusted odds ratio 1.94, 95% CI 1.02, 3.68), although active participants reporting high television viewing were not at risk.

Conclusion

Interventions to reduce the incidence of diabetes in the elderly that focus on both increasing physical activity and reducing television viewing time might prove useful.
Live/Real Time Three‐Dimensional Transesophageal Echocardiographic Assessment of the Spinal Cord
Authors: Ahmed Mustafa I. , Crosland William A. , Gok Gulay , Yuzbas Burcu , Elguindy Mostafa , Esmat Ahmed Ahmed Hesham , Tuck Benjamin C. , Alli Oluseun O. , McMahon William S. , Nanda Navin C.
Published: July 2014

We present an adult patient in whom live/real time three‐dimensional transesophageal echocardiography (3DTEE) provided incremental value in the assessment of the spinal cord as compared to two‐dimensional transesophageal echocardiographic (2DTEE) findings published in the literature. It improved accurate identification and assessment of the anterior radiculomedullary spinal arteries which may have an important clinical application in monitoring for spinal cord ischemia during thoracic aortic surgery. Because the spinal cord and spinal canal could be examined using not only transverse but also coronal (frontal), sagittal, and oblique planes, 3DTEE further allowed for three‐dimensional measurements of the dimensions and volumetric analysis of the visualized spinal cord and spinal canal. These may have implications in the assessment of spinal cord edema due to trauma and other conditions which result in increase in the size and volume of the spinal cord.
Anticipated, Intense Risk Enhances Behavioral Conformity in a Mouse Model
Authors: Cherng Chianfang G. , Wang Ching‐Yi , Lai Yu‐Ting , Tzeng Wen‐Yu , Chen Li‐Hsien , Tsai Yi‐Ni , Yu Lung
Published: July 2014

A mouse conformity model was established by contrasting the differences in the time spent navigating a custom‐made maze when mice were alone versus when they were in a companion group. Experimental mice received one‐trial inhibitory avoidance training by experiencing a foot shock after they arrived at a designated goal box in the maze. In contrast, four mice of the respective companion group received food pellet trainings for rapidly approaching the same goal box. In the retest, mice receiving 0.3‐mA shock in the training trial and navigating alone displayed longer arrival latency to the goal box compared with the mice receiving same level of shock in the training trial and navigating along with the companion group. A conformity index was calculated for the arrival latency of the experimental mice receiving the retest alone and the latency of the experimental mice receiving the retest along with the companion group. In the retest, the conformity index progressively increased with the training foot shock level. No difference was noticed in the arrival latency to the goal box or the conformity index between group‐navigating experimental mice accompanied by familiar and unfamiliar groups. These results, taken together, indicate that behavioral conformity can be enhanced by an expected, intense risk. Moreover, familiarity with the companion group does not affect the behavioral conformity of an individual. We conclude that species members‐shared risk‐detecting and risk‐coping systems could be critical in motivating behavioral conformity for each member of this species.
True Identities: From Performativity to Festival
Authors: Barthold Lauren Swayne
Published: July 2014

Some feminists have criticized Judith Butler's theory of performativity for providing an insufficient account of agency. In this article I first defend her against such charges by appealing to two themes central to Hans‐Georg Gadamer's hermeneutics. I compare her emphasis on the sociohistorical nature of agency with Gadamer's insistence on the historical nature of knowledge, and I examine the significance Butler assigns to repetition and note its affinities with Gadamer's conception of play. In the final part of the article I argue that in spite of providing an adequate account of agency, Butler's theory of performativity provides no way to allow us to evaluate performances. I show how Gadamer's account of festival, which builds on his concept of play, is useful in helping us make sense of how we might delineate true from false performances, and thus identities.
Imposters, Tricksters, and Trustworthiness as an Epistemic Virtue
Authors: Frost‐Arnold Karen
Published: July 2014

This paper argues that trustworthiness is an epistemic virtue that promotes objectivity. I show that untrustworthy imposture can be an arrogant act of privilege that silences marginalized voices. But, as epistemologists of ignorance have shown, sometimes trickery and the betrayal of epistemic norms are important resistance strategies. This raises the question: when is betrayal of trust epistemically virtuous? After establishing that trust is central to objectivity, I argue for the following answer: a betrayal is epistemically vicious when it strengthens or promotes oppressive, exclusive networks of trust, and a betrayal is epistemically virtuous when it expands trust networks to involve the oppressed. These criteria correctly account for both the epistemic vice of a recent case of Internet imposture and the epistemic virtue of resistant tricksters.
How to Screw Things with Words
Authors: Finlayson Lorna
Published: July 2014

Since its influential rendering by Rae Langton in her 1993 paper, “Speech Acts and Unspeakable Acts,” the “silencing argument” against pornography has become the subject of a lively debate that continues to this day. My intention in this paper is not to join in the existing debate, but to give a critical overview of it. In its current form, I suggest, it is going nowhere (and has been en route for too long already). Yet the silencing argument, I believe, nevertheless contains an indispensable insight—and more radical potential than is usually acknowledged either by its defenders or its opponents. I argue that in order to preserve this insight and unleash its potential, we should begin by adopting the following motto: MacKinnon, not Austin!
Stereospecificity and Intracellular Binding of Metaraminol
Authors: Lundborg Per , Stitzel Robert
Published: July 2014

Lundborg, P. and R. E. Stitzel. Stereospecificity and intracellular binding of metaraminol. Acta physiol. scand. 1968. 72. 392–395.

Both d‐ and l‐metaraminol (MA) were able to displace 3H‐dl‐MA from subcellular fractions of the mouse heart when given 15 min after administration of the labelled amine. The l‐form was more effective, however. If the unlabelled isomers were given 24 hrs after 3H‐dl‐MA only the l‐isomer was an effective displacing agent, although it was less effective than when it was given 15 min after the tritiated racemic mixture. These results suggest that d‐MA is not firmly bound to the particulate fraction and is rapidly lost from sympathetically innervated tissues. It is further suggested that there is a transfer of MA from a more to a less available granular storage site with time.
The Distribution of Intravascularly Administered Lipid Soluble and Lipid Insoluble Substances in the Mucosa and the Submucosa of the Small Intestine of the Cat
Authors: Kampp Mogens , Lundgren Ove , Sjöstrand Johan
Published: July 2014

Kampp, M., O. Lundgren and J. Sjöstrand. The distribution of intravascularly administered lipid soluble and lipid insoluble substances in the mucosa and the submucosa of the small intestine of the cat. Acta physiol. scand. 1968. 72. 469–480.

The distribution of intra‐arterially injected antipyrine‐C14 (lipid soluble) and urea‐C14 (lipid insoluble) in the mucosa and the submucosa of the cat intestine was investigated by autoradiography at various levels of total intestinal blood flow. At a “resting” flow level a comparatively low concentration of both tracers was noted in the villi five sec after the isotope administration. The difference in concentration between crypts and villi was most pronounced for antipyrine‐C14. Further, it was demonstrated that the two tracers were eliminated slowly from the tips of the villi at “rest”. When the intestinal vascular bed was dilated by isopropylnoradrenaline, the concentration of the tracers immediately after the injection seemed more or less constant throughout the mucosa. The rate of wash‐out from the villi of the two tracers was, furthermore, constant. Experiments were also performed at “resting” blood flow, in which the distribution of intra‐arterially infused 4‐iodoantipyrine (lipid soluble) and rubidium (lipid insoluble) was determined in three or four transverse sections of the villi. Results consistent with those described above were obtained. The findings suggest the existence of countercurrent exchange, particularly of lipid soluble substances, between the ascending and descending limbs of the mucosal vascular loops mainly located in the villi.
Effects of Carotid Baroreceptor Reflexes on Venous Tone in Skeletal Muscle and Intestine of the Cat
Authors: Hadjiminas John , ÖBerg Bengt
Published: July 2014

Hadjiminas, J. and B. Öberg. Effects of carotid baroreceptor reflexes on venous tone in skeletal muscle and intestine of the cat. Acta physiol. scand. 1968. 72. 518–532.

The engagement of skeletal muscle and intestinal veins in baroreceptor reflexes was quantitatively evaluated by comparing the reflex responses of the resistance and capacitance vessels with those obtained with direct stimulation of the regional vasoconstrictor fibres. Such comparisons revealed that the reflex constriction of skeletal muscle veins, following a diminution of baroreceptor activity, was, in general, considerably smaller than the concomitant resistance vessel constriction. This discrepancy points to a definitely lower, reflex discharge rate in the venoconstrictor fibres. When, however, vasomotor centre excitation, following withdrawal of baroreceptor restraint, was intense, the ensuing venoconstriction in skeletal muscles became as pronounced as that of the resistance vessels. In the intestine, the reflex responses of the capacitance and resistance vessels were always equally pronounced, indicating an essentially uniform reflex discharge rate in all intestinal vasomotor fibres. However, in comparison with the muscle resistance vessels, the intestinal vascular bed seems to be only moderately involved in baroreceptor reflexes. — It is concluded that the capacitance vessels in the studied circuits participate in baroreceptor reflexes but less extensively than the muscle resistance vessels. The functional significance of the differentiated reflex vascular response pattern in skeletal muscles is discussed with special reference to the consequences for the net fluid exchange across the capillaries.
The Extraction Fraction of p‐Aminohippurate in the Superficial and Deep Venous Drainage Area of the Cat Kidney
Authors: Nissen O. I.
Published: July 2014

At plasma concentrations below 40 μg/ml the average extraction fraction of PAH was 0.95 in the superficial drainage area (consisting of approximately the outer half of the cortex), and 0.82 in the deep drainage area (the inner cortex + the medulla). Loading with Ringer's fluid, mannitol solution or plasma generally resulted in a decrease in the extraction fraction of both areas. The two extraction fractions fell to 0.86 and 0.64, respectively. The incompleteness of the extraction cannot be attributed to admixture of blood from the fibrous and fatty capsules of the kidney or to impurities in the PAH preparations. The erythrocytes showed a very low permeability to PAH; correction of renal venous plasma concentrations for diffusion of PAH from erythrocytes to plasma is unnecessary in the cat.—The Reubi principle of calculating the medullary plasma flow as the difference between the total renal plasma flow and the clearance of PAH is misleading in the cat, as it presumes complete extraction in cortical tissue.
Similarities between the Vascular Smooth Muscle Responses to Sudden Changes in External Potassium, Sodium and Chloride Ion Concentrations
Authors: Johansson Börje , Jonsson Olof
Published: July 2014

The effects of graded reductions in extracellular potassium, sodium and chloride concentrations on the spontaneous electrical and mechanical activity of the isolated rat portal vein have been studied. The immediate responses obtained on marked reduction in these ion concentrations and on readministration of normal solution were common to the three ion species and differed from the long‐term effect of the ionic environment. Thus abrupt large reductions in the concentration of any of the three ions resulted in a transient excitation whereas return to normal Krebs solution led to a temporary complete inhibition of muscle activity. These initial, transient responses could in many cases not be predicted on the basis of the “constant field equation” by merely inserting the actual ion concentration values. However, if the concentrations of chloride and potassium ions (or chloride and sodium ions) were changed in a reciprocal manner no such transient responses occurred. Some possible explanations for this difference between the immediate and long‐term effects of a changed ionic environment are discussed.
Metabolic Effects of Glucose Infusion in Man
Authors: Svedmyr Nils
Published: July 2014

In experiments on man the potential importance of the hyperglycemic effect of adrenaline for its calorigenic action was studied. Glucose was infused i.v. in a dose of 0.005 g/kg/min for 30 min (total dose 22 g). The concentration of glucose in blood increased a little more (78 ± 4.2 mg/100 ml) than after an infusion of adrenaline in a dose of 0.10 μg/kg/min for 30 min (54 ± 4.3 mg/100 ml). The oxygen consumption was not stimulated during or after the glucose infusion. The CO2‐elimination and the respiratory quotient (RQ) increased, however. The free fatty acid content in plasma decreased but the lactate concentration in the blood was not altered. It is probable that the hyperglycemic effect of adrenaline is of no importance for its calorigenic action.
Role of Myogenic Propagation in Vascular Smooth Muscle Response to Vasomotor Nerve Stimulation
Authors: Johansson Börje , Ljung Bengt
Published: July 2014

Innervated preparations of the spontaneously active vascular smooth muscle of the rat portal vein were used for the present study. The preparation was so arranged as to allow blockade of myogenic conduction between two adjacent portions. It was also possible to subject one of the portions selectively to adrenergic receptor blockade. It could be shown that myogenic propagation is necessary for coordination of the neurogenic contractile response, as is the case with the synchronization of the spontaneous myogenic activity. Moreover, after the direct response to noradrenaline and adrenergic nerve stimulation had been blocked in one portion of the muscle selectively, its activity was still enhanced during nerve stimulation by means of a myogenic spread of excitation from the other portion, where the innervation and adrenergic receptor function were intact. It is concluded that myogenic conduction contributes to the effectiveness of neurogenic activation by coordinating the contractions and by recruiting non‐innervated muscle cells to participate in the response. The results are discussed in relation to the sparse innervation described in vascular smooth muscle.
A Method to Determine Osmotically Effective Albumin and Gammaglobulin Concentrations in Tissue Fluids, Its Application to the Uvea and a Note on the Effects of Capillary “Leaks” on Tissue Fluid Dynamics
Authors: Bill Anders
Published: July 2014

Choroids and ciliary processes from rabbits were incubated with labelled myoglobin, albumin and gammaglobulin and the equilibrium spaces were determined. Using experimental data for the in vivo steady state myoglobin space in each tissue an approximate value for the in vivo equilibrium space could be calculated. The in vivo albumin and gammaglobulin equilibrium spaces were calculated using the data for in vivo equilibrium myoglobin spaces and the differences in spaces determined in vitro. Values for the effective albumin and gammaglobulin concentrations in the tissues were calculated by dividing the in vivo steady state spaces by the calculated in vivo equilibrium spaces. In the choroid the effective albumin and gammaglobulin concentrations were 68 and 48 per cent of those in plasma respectively. In the ciliary processes the corresponding figures were 74 and 67 per cent.

Model experiments showed that in membranes with 500 Å pores the apparent colloid osmotic pressure of rabbit plasma, 3 % albumin and 3 % gammaglobulin is less than 1 cm H2O.

The results indicate that in the choroid and the ciliary processes there is a net outflow of water in the semipermeable parts of the blood vessels having a transmural hydrostatic pressure difference of more than 7 mmHg. In pores permitting protein passage still less is required to give net outward filtration.
Maintenance of Noradrenaline Synthesis in Rats after Reserpine Treatment
Authors: Wennmalm ÅKe
Published: July 2014

Studies of the excretion in the urine of noradrenaline (NA) and 3‐methoxy‐4‐hydroxymandelic acid (VMA) during 5 days treatment with 0.05—0.1 rpg/kg of reserpine in rats with demedullated adrenal glands arc reported. The excretion of NA was moderately reduced but VMA excretion was not significantly influenced by this treatment, although the heart was almost completely depleted of NA within 48 hours. These results indicate that synthesis of NA may continue in spite of reserpine treatment causing tissue depletion of the amine, suggesting the normal storage is not a prerequisite for resynthesis.
The Reflection of the Age, Tissue and Solubility on the Amberlite CG‐50 Fractions of Denatured Collagens
Authors: Pikkarainen E. Kulonen and J.
Published: July 2014

Collagen was extracted and purified from the skins of young and full‐grown guinea pigs and from the skins and tendons of calf and cow, first with neutral salt solutions and acidic buffers in the cold and then the residue was gelatinized by stepwise heating. In the young animals the collagenous material which could be solubilized at +65° C already was increased markedly. The various denatured collagens were fractionated with Amberlite CG‐50 columns, eluted with buffers of increasing ionic strength and pH and finally with sodium hydroxide. The first fraction, emerging at pH 5.50, was large in the samples from soluble collagen (in comparison to insoluble), in the extracts from insoluble collagens of young animals (in comparison to adults) and in the collagenous fractions of tendon (in comparison to the skin). The gradientbuffer‐eluted fraction which had been derived from insoluble collagen at progressively raised temperatures contained in abundance imino acids and hydroxy amino acids (in comparison to soluble collagens).
Effect of Feeding on Antral and Duodenal Gastrin Activity
Authors: Fyrö Bengt
Published: July 2014

Antral and duodenal gastrin activity was determined in cats at different times after a meal of fish. Cats starved for 24 hrs were used as controls. At 1.5 and 3 hrs after feeding the antral gastrin activity was reduced to about 40 per cent of controls. At 6 hrs there was a trend towards restoration and after 12 hrs the antral gastrin activity was back to control level. Starving for either 2 or 4 days did not influence the antral gastrin activity. The duodenal gastrin activity was about 60 per cent of controls 3 hrs after feeding. Vagotomy did not seem to influence the reduction of the gastrin activity 3 hrs after feeding.
Vasopressin and Intrarenal Blood Flow Distribution
Authors: Aukland Knut
Published: July 2014

It 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

The 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

The 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

Gastrin 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

Mucosal 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

The 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.