bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential effect of sympathetic activation on tissue oxygenation in gastrocnemius and soleus muscles during exercise in humans
Authors: Horiuchi Masahiro , Fadel Paul J. , Ogoh Shigehiko 
Published: October 2013

New Findings
What is the central question of this study?
The normal ability of sympathetic nerves to cause vasoconstriction is blunted in exercising skeletal muscle, a phenomenon termed ‘functional sympatholysis’. Animal studies suggest that functional sympatholysis appears to occur preferentially in fast‐twitch type II glycolytic compared with slow‐twitch type I oxidative skeletal muscle. We asked whether these findings can be extended to humans.
What is the main finding and its importance?
We show that skeletal muscles composed largely of fast‐twitch type II fibres may also be more sensitive to functional sympatholysis in humans, particularly at lower exercise intensities. Additionally, independent of muscle fibre type composition, the magnitude of sympatholysis is strongly related to exercise‐induced increases in metabolic demand.
Animal studies suggest that functional sympatholysis appears to occur preferentially in glycolytic (largely type II) compared with oxidative (largely type I) skeletal muscle. Whether these findings can be extended to humans currently remains unclear. In 12 healthy male subjects, vasoconstrictor responses in gastrocnemius (i.e. primarily type II) and soleus muscles (i.e. primarily type I) were measured using near‐infrared spectroscopy to detect decreases in muscle oxygenation (HbO2) in response to sympathetic activation evoked by a cold pressor test (CPT). The HbO2 responses to a CPT at rest were compared with responses during steady‐state plantar flexion exercise (30 repetitions min−1) performed at 10, 20 and 40% maximal voluntary contraction (MVC) for 6 min. In resting conditions, HbO2 at the gastrocnemius (−14 ± 1%) and soleus muscles (−16 ± 1%) decreased significantly during CPT, with no differences between muscles. During planter flexion at 20% MVC, the change in HbO2 in response to the CPT was blunted in gastrocnemius but not soleus, whereas during 40% MVC both muscles exhibited a significant attenuation to sympathetic activation. The decreases in HbO2 in response to the CPT during exercise were significantly correlated with the metabolic demands of exercise (the decreases in HbO2 in response to steady‐state plantar flexion) in both gastrocnemius and soleus muscles. Collectively, these results suggest that skeletal muscles composed mainly of glycolytic type II fibres are more sensitive to functional sympatholysis, particularly at lower intensities of exercise. Moreover, the blunting of sympathetic vasoconstriction during exercise is strongly related to metabolic demand; an effect that appears independent of fibre type composition.
Influence of locomotor muscle afferent inhibition on the ventilatory response to exercise in heart failure
Authors: Olson Thomas P. , Joyner Michael J. , Eisenach John H. , Curry Timothy B. , Johnson Bruce D. 
Published: October 2013

New Findings
What is the central question of this study?
Patients with heart failure often develop ventilatory abnormalities at rest and during exercise, but the mechanisms underlying these abnormalities remain unclear. This study investigated the influence of inhibiting afferent neural feedback from locomotor muscles on the ventilatory response during exercise in heart failure patients.
What is the main finding and its importance?
Our results suggest that inhibiting afferent feedback from locomotor muscle via intrathecal opioid administration significantly reduces the ventilatory response to exercise in heart failure patients.
Patients with heart failure (HF) develop ventilatory abnormalities at rest and during exercise, but the mechanism(s) underlying these abnormalities remain unclear. We examined whether the inhibition of afferent neural feedback from locomotor muscles during exercise reduces exercise ventilation in HF patients. In a randomized, placebo‐controlled design, nine HF patients (age, 60 ± 2 years; ejection fraction, 27 ± 2%; New York Heart Association class 2 ± 1) and nine control subjects (age, 63 ± 2 years) underwent constant‐work submaximal cycling (65% peak power) with intrathecal fentanyl (impairing the cephalad projection of opioid receptor‐sensitive afferents) or sham injection. The hypercapnic ventilatory response was measured to determine whether cephalad migration of fentanyl occurred. There were no differences in hypercapnic ventilatory response within or between groups in either condition. Despite a lack of change in ventilation, tidal volume or respiratory rate, HF patients had a mild increase in arterial carbon dioxide () and a decrease in oxygen (; P < 0.05 for both) at rest. The control subjects demonstrated no change in , , ventilation, tidal volume or respiratory rate at rest. In response to fentanyl during exercise, HF patients had a reduction in ventilation (63 ± 6 versus 44 ± 3 l min−1, P < 0.05) due to a lower respiratory rate (30 ± 1 versus 26 ± 2 breaths min−1, P < 0.05). The reduced ventilation resulted in lower (97.6 ± 2.5 versus 79.5 ± 3.0 mmHg, P < 0.05) and increased (37.3 ± 0.9 versus 43.5 ± 1.1 mmHg, P < 0.05), with significant improvement in ventilatory efficiency (reduction in the ventilatory equivalent for carbon dioxide; P < 0.05 for all). The control subjects had no change in ventilation or measures of arterial blood gases. These data suggest that inhibition of afferent feedback from locomotor muscle significantly reduces the ventilatory response to exercise in HF patients.
Mother's exercise during pregnancy programmes vasomotor function in adult offspring
Authors: Bahls Martin , Sheldon Ryan D. , Taheripour Pardis , Clifford Kerry A. , Foust Kallie B. , Breslin Emily D. , Marchant‐Forde Jeremy N. , Cabot Ryan A. , Harold Laughlin M. , Bidwell Christopher A. , Newcomer Sean C. 
Published: October 2013

New Findings
What is the central question of this study?Adverse maternal behaviour during pregnancy is well known to have lifelong health consequences for offspring. We asked whether a positive maternal health behaviour may have positive long‐term effects for offspring. Specifically, we investigated whether aerobic maternal exercise improves nitric oxide signalling in femoral arteries of adult swine.
What is the main finding and its importance?For the first time, a fetal programming outcome due to gestational exercise is reported in adult offspring. Second, contrary to previous speculation regarding the impact of in utero alterations on nitric oxide signalling, our data suggest differential myosin phosphorylation in vascular smooth muscle.
The intrauterine environment is influenced by maternal behaviour and programmes atherosclerotic disease susceptibility in offspring. The aim of this investigation was to test the hypothesis that mothers’ exercise during pregnancy improves endothelial function in 3‐, 5‐ and 9‐month‐old porcine offspring. The pregnant sows in the exercise group ran for an average of 39.35 ± 0.75 min at 4.81 ± 0.35 km h−1 each day for 5 days per week for all but the last week of gestation. This induced a significant reduction in resting heart rate (exercised group, 89.3 ± 3.5 beats min−1; sedentary group, 102.1 ± 3.1 beats min−1; P < 0.05) but no significant differences in gestational weight gain (65.8 ± 2.1 versus 63.3 ± 1.9%). No significant effect on bradykinin‐induced vasorelaxation with and without l‐NAME was observed. A significant main effect was identified on sodium nitroprusside‐induced vasorelaxation (P= 0.01), manifested by a reduced response in femoral arteries of all age groups from exercised‐trained swine. Nitric oxide signalling was not affected by maternal exercise. Protein expression of MYPT1 was reduced in femoral arteries from 3‐month‐old offspring of exercised animals. A significant interaction was observed for PPP1R14A (P < 0.05) transcript abundance and its protein product CPI‐17. In conclusion, pregnant swine are able to complete an exercise‐training protocol that matches the current recommendations for pregnant women. Gestational exercise is a potent stimulus for programming vascular smooth muscle relaxation in adult offspring. Specifically, exercise training for the finite duration of pregnancy decreases vascular smooth muscle responsiveness in adult offspring to an exogenous nitric oxide donor.
Selman A. Waksman, Winner of the 1952 Nobel Prize for Physiology or Medicine
Authors: Woodruff H. Boyd 
Published: October 2013

ABSTRACT

The history of the discovery and development of streptomycin is reviewed here from the personal standpoint of a member of Dr. Selman Waksman's antibiotic screening research team. The team approach of eight individuals illustrates how the gradual enhancement of the screening methodology was developed. I illustrate three study periods with key aspects in the development of streptomycin which led to a Nobel Prize being granted to Professor Waksman. One item not previously emphasized is the employment of a submerged culture technique for large-scale production of streptomycin, thus enabling rapid animal testing and human clinical trials with
Mycobacterium tuberculosis
. Another is that purified streptomycin was shown by Dr. Waksman to be distinctly different from the substances called natural products, which are no longer patentable in the United States; therefore, streptomycin was found to be patentable. A third item not previously emphasized is his emphasis on the screening of actinomycetes, including the newly named
Streptomyces
genus. All of these factors contributed to the success of streptomycin in the treatment of tuberculosis. In combination, their successes led to Dr. Waksman's department becoming a new pharmacological research area, specializing in drug discovery. These unique accomplishments all burnish the prior rationales used by the Karolinska Institute in granting Dr. Waksman alone the 1952 Nobel Prize for Physiology or Medicine.
Primer Modification Improves Rapid and Sensitive
In Vitro
and Field-Deployable Assays for Detection of High Plains Virus Variants
Authors: Arif M. , Aguilar-Moreno G. S. , Wayadande A. , Fletcher J. , Ochoa-Corona F. M. 
Published: October 2013

ABSTRACT

A high consequence pathogen,
High plains virus
(HPV) causes considerable damage to wheat if the crop is infected during early stages of development. Methods for the early, accurate, and sensitive detection of HPV in plant tissues are needed for the management of disease outbreaks and reservoir hosts. In this study, the effectiveness of five methods—real-time SYBR green and TaqMan reverse transcription-quantitative PCR (RT-qPCR), endpoint RT-PCR, RT-helicase dependent amplification (RT-HDA) and the Razor Ex BioDetection System (Razor Ex)—for the broad-range detection of HPV variants was evaluated. Specific PCR primer sets and probes were designed to target the HPV nucleoprotein gene. Primer set HPV6F and HPV4R, which amplifies a product of 96 bp, was validated
in silico
against published sequences and
in vitro
against an inclusivity panel of infected plant samples and an exclusivity panel of near-neighbor viruses. The primers were modified by adding a customized 22 nucleotide long tail at the 5′ terminus, raising the primers' melting temperature (

T
m

; ca. 10°C) to make them compatible with RT-HDA (required optimal

T
m

= 68°C), in which the use of primers lacking such tails gave no amplification. All of the methods allowed the detection of as little as 1 fg of either plasmid DNA carrying the target gene sequence or of infected plant samples. The described
in vitro
and in-field assays are accurate, rapid, sensitive, and useful for pathogen detection and disease diagnosis, microbial quantification, and certification and breeding programs, as well as for biosecurity and microbial forensics applications.
Detection of Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli on Flies at Poultry Farms
Authors: Blaak Hetty , Hamidjaja Raditijo A. , van Hoek Angela H. A. M. , de Heer Lianne , de Roda Husman Ana Maria , Schets Franciska M. 
Published: October 2013

ABSTRACT

In the Netherlands, extended-spectrum beta-lactamase (ESBL)-producing
Escherichia coli
bacteria are highly prevalent in poultry, and chicken meat has been implicated as a source of ESBL-producing
E. coli
present in the human population. The current study describes the isolation of ESBL-producing
E. coli
from house flies and blow flies caught at two poultry farms, offering a potential alternative route of transmission of ESBL-producing
E. coli
from poultry to humans. Overall, 87 flies were analyzed in 19 pools. ESBL-producing
E. coli
bacteria were detected in two fly pools (10.5%): a pool of three blow flies from a broiler farm and a pool of eight house flies from a laying-hen farm. From each positive fly pool, six isolates were characterized and compared with isolates obtained from manure (
n
= 53) sampled at both farms and rinse water (
n
= 10) from the broiler farm. Among six fly isolates from the broiler farm, four different types were detected with respect to phylogenetic group, sequence type (ST), and ESBL genotype: A
0
/ST3519/SHV-12, A
1
/ST10/SHV-12, A
1
/ST58/SHV-12, and B1/ST448/CTX-M-1. These types, as well as six additional types, were also present in manure and/or rinse water at the same farm. At the laying-hen farm, all fly and manure isolates were identical, carrying
bla
TEM-52
in an A
1
/ST48 genetic background. The data imply that flies acquire ESBL-producing
E. coli
at poultry farms, warranting further evaluation of the contribution of flies to dissemination of ESBL-producing
E. coli
in the community.
Osmoadaptation Strategy of the Most Halophilic Fungus, Wallemia ichthyophaga, Growing Optimally at Salinities above 15% NaCl
Authors: Zajc Janja , Kogej Tina , Galinski Erwin A. , Ramos José , Gunde-Cimerman Nina 
Published: October 2013

ABSTRACT

Wallemia ichthyophaga
is a fungus from the ancient basidiomycetous genus
Wallemia
(Wallemiales, Wallemiomycetes) that grows only at salinities between 10% (wt/vol) NaCl and saturated NaCl solution. This obligate halophily is unique among fungi. The main goal of this study was to determine the optimal salinity range for growth of the halophilic
W. ichthyophaga
and to unravel its osmoadaptation strategy. Our results showed that growth on solid growth media was extremely slow and resulted in small colonies. On the other hand, in the liquid batch cultures, the specific growth rates of
W. ichthyophaga
were higher, and the biomass production increased with increasing salinities. The optimum salinity range for growth of
W. ichthyophaga
was between 15 and 20% (wt/vol) NaCl. At 10% NaCl, the biomass production and the growth rate were by far the lowest among all tested salinities. Furthermore, the cell wall content in the dry biomass was extremely high at salinities above 10%. Our results also showed that glycerol was the major osmotically regulated solute, since its accumulation increased with salinity and was diminished by hypo-osmotic shock. Besides glycerol, smaller amounts of arabitol and trace amounts of mannitol were also detected. In addition,
W. ichthyophaga
maintained relatively small intracellular amounts of potassium and sodium at constant salinities, but during hyperosmotic shock, the amounts of both cations increased significantly. Given our results and the recent availability of the genome sequence,
W. ichthyophaga
should become well established as a novel model organism for studies of halophily in eukaryotes.
A Distinct Model of Synergism between a Processive Endocellulase (TfCel9A) and an Exocellulase (TfCel48A) from Thermobifida fusca
Authors: Kostylev Maxim , Wilson David 
Published: October 2013

ABSTRACT

Lignocellulosic biomass is digested in nature by the synergistic activities of enzymes with complementary properties, and understanding synergistic interactions will improve the efficiency of industrial biomass use for sustainable fuels and chemicals. Cel9A and Cel48A from a model bacterium,
Thermobifida fusca
(TfCel9A and TfCel48A, respectively), are two cellulases with different properties and have previously been shown to synergize well with each other. TfCel9A is a processive endocellulase with relatively high activity on crystalline cellulose. TfCel48A is a reducing end-directed exocellulase with very low activity on crystalline cellulose. Neither enzyme fits its respective role in the classical synergism model of enzymatic cellulose digestion. Using the results of time course, endpoint, and sequential addition activity assays, we propose a model of synergistic cooperation between the two cellulases. TfCel9A is most effective on fresh bacterial cellulose with a presumably uniform surface at the molecular level. Its processive activity likely erodes the surface and thus reduces its own activity. TfCel48A is able to hydrolyze the TfCel9A-modified substrate efficiently and replenish the uniform surface required by TfCel9A, creating a feedback mechanism. The model of synergistic interactions is comparable to an earlier proposed model for
Trichoderma reesei
Cel7A and Cel7B, but the roles of endo- and exocellulases are reversed, a finding which suggests that bacteria and fungi may have evolved different approaches to efficient biomass degradation.
CRISPRs: Molecular Signatures Used for Pathogen Subtyping
Authors: Shariat Nikki , Dudley Edward G. 
Published: October 2013

ABSTRACT

Rapid and accurate strain identification is paramount in the battle against microbial outbreaks, and several subtyping approaches have been developed. One such method uses
c
lustered
r
egular
i
nterspaced
s
hort
p
alindromic
r
epeats (CRISPRs), DNA repeat elements that are present in approximately half of all bacteria. Though their signature function is as an adaptive immune system against invading DNA such as bacteriophages and plasmids, CRISPRs also provide an excellent framework for pathogen tracking and evolutionary studies. Analysis of the spacer DNA sequences that reside between the repeats has been tremendously useful for bacterial subtyping during molecular epidemiological investigations. Subtyping, or strain identification, using CRISPRs has been employed in diverse Gram-positive and Gram-negative bacteria, including
Mycobacterium tuberculosis
,
Salmonella enterica
, and the plant pathogen
Erwinia amylovora
. This review discusses the several ways in which CRISPR sequences are exploited for subtyping. This includes the well-established spoligotyping methodologies that have been used for 2 decades to type
Mycobacterium
species, as well as in-depth consideration of newer, higher-throughput CRISPR-based protocols.
Critical Assessment of Glyco- and Phospholipid Separation by Using Silica Chromatography
Authors: Heinzelmann Sandra M. , Bale Nicole J. , Hopmans Ellen C. , Sinninghe Damsté Jaap S. , Schouten Stefan , van der Meer Marcel T. J. 
Published: October 2013

ABSTRACT

Phospholipid-derived fatty acids (PLFAs) are commonly used to characterize microbial communities
in situ
and the phylogenetic positions of newly isolated microorganisms. PLFAs are obtained through separation of phospholipids from glycolipids and neutral lipids using silica column chromatography. We evaluated the performance of this separation method for the first time using direct detection of intact polar lipids (IPLs) with high-performance liquid chromatography–mass spectrometry (HPLC-MS). We show that under either standard or modified conditions, the phospholipid fraction contains not only phospholipids but also other lipid classes such as glycolipids, betaine lipids, and sulfoquinovosyldiacylglycerols. Thus, commonly reported PLFA compositions likely are not derived purely from phospholipids and perhaps may not be representative of fatty acids present in living microbes.
Temporal Variability of the Bioaerosol Background at a Subway Station: Concentration Level, Size Distribution, and Diversity of Airborne Bacteria
Authors: Dybwad Marius , Skogan Gunnar , Blatny Janet Martha 
Published: October 2013

ABSTRACT

Naturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 10
3
CFU m
−3
and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents.
Predominant Acidilobus-Like Populations from Geothermal Environments in Yellowstone National Park Exhibit Similar Metabolic Potential in Different Hypoxic Microbial Communities
Authors: Jay Z. J. , Rusch D. B. , Tringe S. G. , Bailey C. , Jennings R. M. , Inskeep W. P. 
Published: October 2013

ABSTRACT

High-temperature (>70°C) ecosystems in Yellowstone National Park (YNP) provide an unparalleled opportunity to study chemotrophic archaea and their role in microbial community structure and function under highly constrained geochemical conditions.
Acidilobus
spp. (order
Desulfurococcales
) comprise one of the dominant phylotypes in hypoxic geothermal sulfur sediment and Fe(III)-oxide environments along with members of the
Thermoproteales
and
Sulfolobales
. Consequently, the primary goals of the current study were to analyze and compare replicate
de novo
sequence assemblies of
Acidilobus
-like populations from four different mildly acidic (pH 3.3 to 6.1) high-temperature (72°C to 82°C) environments and to identify metabolic pathways and/or protein-encoding genes that provide a detailed foundation of the potential functional role of these populations
in situ. De novo
assemblies of the highly similar
Acidilobus
-like populations (>99% 16S rRNA gene identity) represent near-complete consensus genomes based on an inventory of single-copy genes, deduced metabolic potential, and assembly statistics generated across sites. Functional analysis of coding sequences and confirmation of gene transcription by
Acidilobus
-like populations provide evidence that they are primarily chemoorganoheterotrophs, generating acetyl coenzyme A (acetyl-CoA) via the degradation of carbohydrates, lipids, and proteins, and auxotrophic with respect to several external vitamins, cofactors, and metabolites. No obvious pathways or protein-encoding genes responsible for the dissimilatory reduction of sulfur were identified. The presence of a formate dehydrogenase (Fdh) and other protein-encoding genes involved in mixed-acid fermentation supports the hypothesis that
Acidilobus
spp. function as degraders of complex organic constituents in high-temperature, mildly acidic, hypoxic geothermal systems.