bluuebunny/crossref_metadata_2025 huggingface dataset:
Catecholaminergic signalling through thymic nerve fibres, thymocytes and stromal cells is dependent on both circulating and locally synthesized glucocorticoids
Authors: Pilipović I. , Radojević K. , Perišić M. , Kosec D. , Nacka‐Aleksić M. , Djikić J. , Leposavić G.
Published: May 2012

Glucocorticoids have been shown to modulate the expression of noradrenaline metabolizing enzymes and β2‐ and α1B‐adrenoceptors in a tissue‐ and cell‐ specific manner. In the thymus, apart from extensive sympathetic innervation, a regulatory network has been identified that encompasses catecholamine‐containing non‐lymphoid and lymphoid cells. We examined a putative role of adrenal‐ and thymus‐derived glucocorticoids in modulation of rat thymic noradrenaline levels and adrenoceptor expression. Seven days postadrenalectomy, the thymic levels of mRNAs encoding tyrosine hydroxylase, dopamine β‐hydroxylase, monoamine oxidase‐A and, consequently, noradrenaline were decreased. Catecholamine content was diminished in autofluorescent nerve fibres (judging by the intensity of fluorescence) and thymocytes (considering HPLC measurements of noradrenaline and the frequency of tyrosine hydroxylase‐positive cells), while it remained unaltered in non‐lymphoid autofluorescent cells. In addition, adrenalectomy diminished the thymocyte expression of β2‐ and α1B‐adrenoceptors at both mRNA and protein levels. Administration of ketoconazole (an inhibitor of glucocorticoid synthesis/action; 25 mg kg−1 day−1, s.c.) to glucocorticoid‐deprived rats increased the thymic levels of tyrosine hydroxylase, dopamine β‐hydroxylase and, consequently, noradrenaline. The increased intensity of the autofluorescent cell fluorescence in ketoconazole‐treated rats indicated an increase in their catecholamine content, and suggested differential glucocorticoid‐mediated regulation of catecholamines in thymic lymphoid and non‐lymphoid cells. In addition, ketoconazole increased the thymocyte expression of α1B‐adrenoceptors. Thus, this study indicates that in the thymus, as in some other tissues, glucocorticoids not only act in concert with cateholamines, but they may modulate catecholamine action by tuning thymic catecholamine metabolism and adrenoceptor expression in a cell‐specific manner. Additionally, the study indicates a role of thymus‐derived glucocorticoids in this modulation.
Inhibition of sarcoplasmic reticulum Ca2+‐ATPase decreases atrioventricular node‐paced heart rate in rabbits
Authors: Cheng Hongwei , Smith Godfrey L. , Orchard Clive H. , Hancox Jules C. , Burton Francis L.
Published: May 2012

Recent data indicate that Ca2+ cycling in isolated atrioventricular node (AVN) cells contributes to setting spontaneous rate. The aim of the present study was to extend this observation to the intact AVN in situ, by evaluating the effects of inhibiting sarcoplasmic reticulum Ca2+ uptake with cyclopiazonic acid (CPA) on intact AVN spontaneous activity and its response to isoprenaline. A model of the AVN‐paced heart was produced to investigate intact AVN automaticity, by surgical ablation of the sino‐atrial node (SAN) in the rabbit Langendorff‐perfused heart. Electrograms were recorded from a site close to the AVN (triangle of Koch), an atrial site above the AVN, the left atrium and right ventricle, enabling AVN pacing of the preparation to be confirmed. Before SAN ablation, the heart rate was 166.8 ± 5.4 beats min−1. Ablation of the SAN was clearly indicated by a sudden and significant decrease of heart rate to 108.6 ± 9.6 beats min−1 (P < 0.01, n = 10). Isoprenaline (100 nm) increased AVN rate to 187.8 ± 12.0 beats min−1 after 1 min of application (P < 0.01, n = 10). Cyclopiazonic acid (10 and 30 μm) decreased AVN rate to 81.6 ± 4.8 (n = 9) and 77.4 ± 6.0 beats min−1 (n = 7), respectively [P < 0.05, 10 or 30 μm CPA versus control (n = 10)] and also reduced the AVN rate increase in response to isoprenaline from 78.8 ± 10.0 to 46.8 ± 6.8 and 26.7 ± 5.3%, respectively (P < 0.01). These inhibitory effects of CPA on the intact AVN rate and its response to isoprenaline indicate that Ca2+ cycling is important to the intact AVN spontaneous activity and its acceleration during sympathetic stimulation.
Catabolite Repression Control of Pyocyanin Biosynthesis at an Intersection of Primary and Secondary Metabolism in Pseudomonas aeruginosa
Authors: Huang Jiaofang , Sonnleitner Elisabeth , Ren Bin , Xu Yuquan , Haas Dieter
Published: May 2012

In
Pseudomonas aeruginosa
, the catabolite repression control (Crc) protein repressed the formation of the blue pigment pyocyanin in response to a preferred carbon source (succinate) by interacting with
phzM
mRNA, which encodes a key enzyme in pyocyanin biosynthesis. Crc bound to an extended imperfect recognition sequence that was interrupted by the AUG translation initiation codon.
Screening for a Single-Chain Variable-Fragment Antibody That Can Effectively Neutralize the Cytotoxicity of the Vibrio parahaemolyticus Thermolabile Hemolysin
Authors: Wang Rongzhi , Fang Sui , Wu Dinglong , Lian Junwei , Fan Jue , Zhang Yanfeng , Wang Shihua , Lin Wenxiong
Published: May 2012

Vibrio parahaemolyticus
is a halophilic bacterium that is widely distributed in water resources. The bacterium causes lethal food-borne diseases and poses a serious threat to human and animal health all over the world. The major pathogenic factor of
V. parahaemolyticus
is thermolabile hemolysin (TLH), encoded by the
tlh
gene, but its toxicity mechanisms are unknown. A high-affinity antibody that can neutralize TLH activity effectively is not available. In this study, we successfully expressed and purified the TLH antigen and discovered a high-affinity antibody to TLH, named scFv-LA3, by phage display screening. Cytotoxicity analysis showed that scFv-LA3 has strong neutralization effects on TLH-induced cell toxicity.
Influence of Exposure Time on Gene Expression by Human Intestinal Epithelial Cells Exposed to Lactobacillus acidophilus
Authors: O'Flaherty Sarah , Klaenhammer Todd R.
Published: May 2012

Analysis of global temporal gene expression by human intestinal cells when exposed to
Lactobacillus acidophilus
revealed induction of immune-related pathways and NF-κB target genes after a 1-h exposure, compared to a 4- or 8-h exposure. Additionally, an
L. acidophilus
derivative expressing covalently bound flagellin resulted in increased induction of
il8
,
cxc1
, and
cxcl2
compared to the parent
L. acidophilus
.
Effects of Nitrogen Dioxide and Anoxia on Global Gene and Protein Expression in Long-Term Continuous Cultures of Nitrosomonas eutropha C91
Authors: Kartal Boran , Wessels Hans J. C. T. , van der Biezen Erwin , Francoijs Kees-Jan , Jetten Mike S. M. , Klotz Martin G. , Stein Lisa Y.
Published: May 2012

Nitrosomonas eutrophais an ammonia-oxidizing betaproteobacterium found in environments with high ammonium levels, such as wastewater treatment plants. The effects of NO2on gene and protein expression under oxic and anoxic conditions were determined by maintainingN. eutrophastrain C91 in a chemostat fed with ammonium under oxic, oxic-plus-NO2, and anoxic-plus-NO2culture conditions. Cells remained viable but ceased growing under anoxia; hence, the chemostat was switched from continuous to batch cultivation to retain biomass. After several weeks under each condition, biomass was harvested for total mRNA and protein isolation. Exposure ofN. eutrophaC91 to NO2under either oxic or anoxic conditions led to a decrease in proteins involved in N and C assimilation and storage and an increase in proteins involved in energy conservation, including ammonia monooxygenase (AmoCAB). Exposure to anoxia plus NO2resulted in increased representation of proteins and transcripts reflective of an energy-deprived state. Several proteins implicated in N-oxide metabolism were expressed and remained unchanged throughout the experiment, except for NorCB nitric oxide reductase, which was not detected in the proteome. Rather, NorY nitric oxide reductase was expressed under oxic-plus-NO2and anoxic-plus-NO2conditions. The results indicate that exposure to NO2results in an energy-deprived state ofN. eutrophaC91 and that anaerobic growth could not be supported with NO2as an oxidant.
Chitin-Like Molecules Associate with Cryptococcus neoformans Glucuronoxylomannan To Form a Glycan Complex with Previously Unknown Properties
Authors: Ramos Caroline L. , Fonseca Fernanda L. , Rodrigues Jessica , Guimarães Allan J. , Cinelli Leonardo P. , Miranda Kildare , Nimrichter Leonardo , Casadevall Arturo , Travassos Luiz R. , Rodrigues Marcio L.
Published: May 2012

In prior studies, we demonstrated that glucuronoxylomannan (GXM), the major capsular polysaccharide of the fungal pathogen
Cryptococcus neoformans
, interacts with chitin oligomers at the cell wall-capsule interface. The structural determinants regulating these carbohydrate-carbohydrate interactions, as well as the functions of these structures, have remained unknown. In this study, we demonstrate that glycan complexes composed of chitooligomers and GXM are formed during fungal growth and macrophage infection by
C. neoformans
. To investigate the required determinants for the assembly of chitin-GXM complexes, we developed a quantitative scanning electron microscopy-based method using different polysaccharide samples as inhibitors of the interaction of chitin with GXM. This assay revealed that chitin-GXM association involves noncovalent bonds and large GXM fibers and depends on the
N
-acetyl amino group of chitin. Carboxyl and
O
-acetyl groups of GXM are not required for polysaccharide-polysaccharide interactions. Glycan complex structures composed of cryptococcal GXM and chitin-derived oligomers were tested for their ability to induce pulmonary cytokines in mice. They were significantly more efficient than either GXM or chitin oligomers alone in inducing the production of lung interleukin 10 (IL-10), IL-17, and tumor necrosis factor alpha (TNF-α). These results indicate that association of chitin-derived structures with GXM through their
N
-acetyl amino groups generates glycan complexes with previously unknown properties.
Editosome Accessory Factors KREPB9 and KREPB10 in Trypanosoma brucei
Authors: Lerch Melissa , Carnes Jason , Acestor Nathalie , Guo Xuemin , Schnaufer Achim , Stuart Kenneth
Published: May 2012

Multiprotein complexes, called editosomes, catalyze the uridine insertion and deletion RNA editing that forms translatable mitochondrial mRNAs in kinetoplastid parasites. We have identified here two new U1-like zinc finger proteins that associate with editosomes and have shown that they are related to KREPB6, KREPB7, and KREPB8, and thus we have named them
K
inetoplastid
R
NA
E
diting
P
roteins, KREPB9 and KREPB10. They are conserved and syntenic in trypanosomatids although KREPB10 is absent in
Trypanosoma vivax
and both are absent in
Leishmania
. Tandem affinity purification (TAP)-tagged KREPB9 and KREPB10 incorporate into ∼20S editosomes and/or subcomplexes thereof and preferentially associate with deletion subcomplexes, as do KREPB6, KREPB7, and KREPB8. KREPB10 also associates with editosomes that are isolated via a chimeric endonuclease, KREN1 in KREPB8 RNA interference (RNAi) cells, or MEAT1. The purified complexes have precleaved editing activities and endonuclease cleavage activity that appears to leave a 5′ OH on the 3′ product. RNAi knockdowns did not affect growth but resulted in relative reductions of both edited and unedited mitochondrial mRNAs. The similarity of KREPB9 and KREPB10 to KREPB6, KREPB7, and KREPB8 suggests they may be accessory factors that affect editing endonuclease activity and as a consequence may affect mitochondrial mRNA stability. KREPB9 and KREPB10, along with KREPB6, KREPB7, and KREPB8, may enable the endonucleases to discriminate among and accurately cleave hundreds of different editing sites and may be involved in the control of differential editing during the life cycle of
T. brucei
.
Export Requirements of Pneumolysin in Streptococcus pneumoniae
Authors: Price Katherine E. , Greene Neil G. , Camilli Andrew
Published: May 2012

Streptococcus pneumoniae
is a major causative agent of otitis media, pneumonia, bacteremia, and meningitis. Pneumolysin (Ply), a member of the cholesterol-dependent cytolysins (CDCs), is produced by virtually all clinical isolates of
S. pneumoniae
, and
ply
mutant strains are severely attenuated in mouse models of colonization and infection. In contrast to all other known members of the CDC family, Ply lacks a signal peptide for export outside the cell. Instead, Ply has been hypothesized to be released upon autolysis or, alternatively, via a nonautolytic mechanism that remains undefined. We show that an exogenously added signal sequence is not sufficient for Sec-dependent Ply secretion in
S. pneumoniae
but is sufficient in the surrogate host
Bacillus subtilis
. Previously, we showed that Ply is localized primarily to the cell wall compartment in the absence of detectable cell lysis. Here we show that Ply released by autolysis cannot reassociate with intact cells, suggesting that there is a Ply export mechanism that is coupled to cell wall localization of the protein. This putative export mechanism is capable of secreting a related CDC without its signal sequence. We show that
B. subtilis
can export Ply, suggesting that the export pathway is conserved. Finally, through truncation and domain swapping analyses, we show that export is dependent on domain 2 of Ply.
Substrate Specificity of the Citrate Transporter CitP of Lactococcus lactis
Authors: Pudlik Agata M. , Lolkema Juke S.
Published: May 2012

The citrate transporter CitP of lactic acid bacteria catalyzes electrogenic precursor-product exchange of citrate versus
l
-lactate during citrate-glucose cometabolism. In the absence of sugar,
l
-lactate is replaced by the metabolic intermediates/end products pyruvate, α-acetolactate, and acetate. In this study, the binding and translocation properties of CitP were analyzed systematically for a wide variety of mono- and dicarboxylates of the form X-CR
2
-COO
−
, where X represents OH (2-hydroxy acid), O (2-keto acid), or H (acid) and R groups differ in size, hydrophobicity, and composition. It follows that CitP is a very promiscuous carboxylate transporter. A carboxylate group is both essential and sufficient for recognition by the transporter. A C-2 atom is not essential, formate is a substrate, and C-2 may be part of a ring structure, as in benzoate. The R group may be as bulky as an indole ring structure. For all monocarboxylates of the form X-CHR-COO
−
, the hydroxy (X = OH) analogs were the preferred substrates. The preference for keto (X = O) or acid (X = H) analogs was dependent on the bulkiness of the R group, such that the acid was preferred for small R groups and the 2-ketoacid was preferred for more bulky R groups. The C
4
to C
6
dicarboxylates succinate, glutarate, and adipate were also substrates of CitP. The broad substrate specificity is discussed in the context of a model of the binding site of CitP. Many of the substrates of CitP are intermediates or products of amino acid metabolism, suggesting that CitP may have a broader physiological function than its role in citrate fermentation alone.
Error-Prone PCR Mutagenesis Reveals Functional Domains of a Bacterial Transcriptional Activator, TraJ
Authors: Lu Jun , Peng Yun , Arutyunov Denis , Frost Laura S. , Glover J. N. Mark
Published: May 2012

TraJ is the essential activator of P
Y
, the promoter of the F and F-like plasmid
tra
operon that encodes the majority of the proteins for bacterial conjugation. By combining error-prone PCR mutagenesis with a two-plasmid screen, we isolated 55 missense mutations in
traJ
, each affecting the ability of TraJ to activate P
Y
. These mutations define two distinct functional clusters (amino acids [aa] 21 to 117 and aa 150 to 219). Limited proteolytic analysis of TraJ suggested that the N- and C-terminal functional clusters are two structurally distinct domains. Most TraJ mutants exhibited decreased intracellular protein levels, and the HslVU protease-chaperone pair was found to be responsible for degrading those mutants without extracytoplasmic stress-induced overexpression.
In vivo
cross-linking analysis of TraJ mutants indicated that the N-terminal domain is responsible for dimerization. This was confirmed by the finding that the purified N-terminal region of TraJ forms dimers in solution. The levels of dimerization and
in vivo
activities of TraJ mutants are well correlated, suggesting that dimerization of TraJ is required for its biological function. We propose that the regulation of TraJ dimerization and/or its susceptibility to HslVU could be a key mechanism in various signaling processes for controlling bacterial conjugation in response to physiological or environmental stimuli.
Novel Miniature Transposable Elements in Thermophilic Synechococcus Strains and Their Impact on an Environmental Population
Authors: Nelson William C. , Bhaya Devaki , Heidelberg John F.
Published: May 2012

The genomes of the two closely related freshwater thermophilic cyanobacteria
Synechococcus
sp. strain JA-3-3Ab and
Synechococcus
sp. strain JA-2-3B′a(2-13) each host several families of insertion sequences (ISSoc families) at various copy numbers, resulting in an overall high abundance of insertion sequences in the genomes. In addition to full-length copies, a large number of internal deletion variants have been identified. ISSoc2 has two variants (ISSoc2∂-1 and ISSoc2∂-2) that are observed to have multiple near-exact copies. Comparison of environmental metagenomic sequences to the
Synechococcus
genomes reveals novel placement of copies of ISSoc2, ISSoc2∂-1, and ISSoc2∂-2. Thus, ISSoc2∂-1 and ISSoc2∂-2 appear to be active nonautonomous mobile elements derived by internal deletion from ISSoc2. Insertion sites interrupting genes that are likely critical for cell viability were detected; however, most insertions either were intergenic or were within genes of unknown function. Most novel insertions detected in the metagenome were rare, suggesting a stringent selective environment. Evidence for mobility of internal deletion variants of other insertion sequences in these isolates suggests that this is a general mechanism for the formation of miniature insertion sequences.
Implication of Proteins Containing Tetratricopeptide Repeats in Conditional Virulence Phenotypes of Legionella pneumophila
Authors: Bandyopadhyay Purnima , Sumer Eren U. , Jayakumar Deepak , Liu Shuqing , Xiao Huifang , Steinman Howard M.
Published: May 2012

Legionella pneumophila
, the causative agent of Legionnaires' disease, is a ubiquitous freshwater bacterium whose virulence phenotypes require a type IV secretion system (T4SS).
L. pneumophila
strain JR32 contains two virulence-associated T4SSs, the Dot/Icm and Lvh T4SSs. Defective entry and phagosome acidification phenotypes of
dot
/
icm
mutants are conditional and reversed by incubating broth-grown stationary-phase cultures in water (WS treatment) prior to infection, as a mimic of the aquatic environment of
Legionella
. Reversal of
dot
/
icm
virulence defects requires the Lvh T4SS and is associated with a >10-fold induction of LpnE, a tetratricopeptide repeat (TPR)-containing protein. In the current study, we demonstrated that defective entry and phagosome acidification phenotypes of mutants with changes in LpnE and EnhC, another TPR-containing protein, were similarly reversed by WS treatment. In contrast to
dot
/
icm
mutants for which the Lvh T4SS was required, reversal for the Δ
lpnE
or the Δ
enhC
mutant required that the other TPR-containing protein be present. The single and double Δ
lpnE
and Δ
enhC
mutants showed a hypersensitivity to sodium ion, a phenotype associated with dysfunction of the Dot/Icm T4SS. The Δ
lpnE
single and the Δ
lpnE
Δ
enhC
double mutant showed 3- to 9-fold increases in translocation of Dot/Icm T4SS substrates, LegS2/SplY and LepB. Taken together, these data identify TPR-containing proteins in a second mechanism by which the WS mimic of a
Legionella
environmental niche can reverse virulence defects of broth-grown cultures and implicate LpnE and EnhC directly or indirectly in translocation of Dot/Icm T4SS protein substrates.
Defective Lipoprotein Sorting Induces
lolA
Expression through the Rcs Stress Response Phosphorelay System
Authors: Tao Kazuyuki , Narita Shin-ichiro , Tokuda Hajime
Published: May 2012

The
Escherichia coli
LolA protein is a lipoprotein-specific chaperone that carries lipoproteins from the inner to the outer membrane. A dominant negative LolA mutant, LolA(I93C/F140C), in which both
93
Ile and
140
Phe are replaced by Cys, binds tightly to the lipoprotein-dedicated ABC transporter LolCDE complex on the inner membrane and therefore inhibits the detachment of outer membrane-specific lipoproteins from the inner membrane. We found that the expression of this mutant strongly induced
lolA
gene transcription. The depletion of the LolA or LolB protein also triggered
lolA
gene transcription, indicating that the inhibition of outer membrane lipoprotein transport triggers
lolA
transcription. To elucidate the mechanism, we isolated mutants that are unable to induce
lolA
transcription using the
lacZ
gene fused to the
lolA
promoter as a reporter and found that the Rcs phosphorelay system directly regulates
lolA
transcription. An outer membrane lipoprotein, RcsF, was essential for this activation, while the coactivator RcsA was dispensable. Taking the observation that an RcsF mutant localized in the inner membrane constitutively activated the Rcs phosphorelay system into consideration, the results shown here strongly suggest that correct lipoprotein sorting to the outer membrane is monitored by RcsF, which plays a key role in the Rcs stress response system.
A pragmatic randomised controlled trial in primary care of the Camden Weight Loss (CAMWEL) programme
Authors: Nanchahal Kiran , Power Tom , Holdsworth Elizabeth , Hession Michelle , Sorhaindo Annik , Griffiths Ulla , Townsend Joy , Thorogood Nicki , Haslam David , Kessel Anthony , Ebrahim Shah , Kenward Mike , Haines Andrew
Published: May 2012

Objectives

To evaluate effectiveness of a structured one-to-one behaviour change programme on weight loss in obese and overweight individuals.

Design

Randomised controlled trial.

Setting

23 general practices in Camden, London.

Participants

381 adults with body mass index ≥25 kg/m2randomly assigned to intervention (n=191) or control (n=190) group.

Interventions

A structured one-to-one programme, delivered over 14 visits during 12 months by trained advisors in three primary care centres compared with usual care in general practice.

Outcome measures

Changes in weight, per cent body fat, waist circumference, blood pressure and heart rate between baseline and 12 months.

Results

217/381 (57.0%) participants were assessed at 12 months: missing values were imputed. The difference in mean weight change between the intervention and control groups was not statistically significant (0.70 kg (0.67 to 2.17, p=0.35)), although a higher proportion of the intervention group (32.7%) than the control group (20.4%) lost 5% or more of their baseline weight (OR: 1.80 (1.02 to 3.18, p=0.04)). The intervention group achieved a lower mean heart rate (mean difference 3.68 beats per minute (0.31 to 7.04, p=0.03)) than the control group. Participants in the intervention group reported higher satisfaction and more positive experiences of their care compared with the control group.

Conclusions

Although there is no significant difference in mean weight loss between the intervention and control groups, trained non-specialist advisors can deliver a structured programme and achieve clinically beneficial weight loss in some patients in primary care. The intervention group also reported a higher level of satisfaction with the support received. Primary care interventions are unlikely to be sufficient to tackle the obesity epidemic and effective population-wide measures are also necessary.

Clinical trial registration number

Trial registrationClincaltrials.govNCT00891943.
Current British veterinary attitudes to the use of perioperative antimicrobials in small animal surgery
Authors: Knights C. B. , Mateus A. , Baines S. J.
Published: May 2012

A questionnaire was sent to 2951 mixed and small animal veterinary practices to examine the use of perioperative antimicrobials in cats and dogs in the UK. The percentage of respondents who always used antimicrobials in two surgical procedures classified according to NRC criteria as ‘clean’ was 25.3 per cent for removal of a 1 cm cutaneous mass and 32.1 per cent for routine prescrotal castration. Factors considered important in decision‐making about when to use antimicrobial agents included immunosuppression, presence of a drain, degree of wound contamination, potential for spillage of visceral contents and implantation of prosthesis. The most common antimicrobial agents mentioned were potentiated amoxicillin (98.0 per cent), amoxicillin (60.5 per cent), clindamycin (21.8 per cent), enrofloxacin (21.7 per cent), cephalexin (18.6 per cent) and metronidazole (12.7 per cent). Forty‐three per cent of all responding veterinarians listed a long‐acting preparation for perioperative use. The routes used were subcutaneous (76.1 per cent), intravenous (25.8 per cent), intramuscular (19.8 per cent), oral (13.5 per cent) and topical (7.7 per cent). Antimicrobials were given before surgery (66.6 per cent), during surgery (30.2 per cent), immediately after surgery (12.0 per cent) and after surgery (6.3 per cent). This survey has identified the suboptimal use of perioperative antimicrobials in small animal surgery with improvements needed with respect to timing, duration, choice of antimicrobial and a more prudent selection of surgical cases requiring prophylaxis.
Case‐control study of orf in preweaned lambs and an assessment of the financial impact of the disease
Authors: Lovatt F. M. , Barker W. J. W. , Brown D. , Spooner R. K.
Published: May 2012

Orf, a viral disease which causes proliferative skin lesions around the mouths of lambs and on the teats of ewes, has long been assumed to have production‐limiting consequences. This case‐control study involved the collection of data from naturally occurring outbreaks of orf in young lambs on eight commercial farms in north‐east England. Measurements of weight were taken and orf lesions were scored on a numerical scale for 44 orf‐affected lambs, matched to unaffected controls within the same group. Data from corresponding ewes were available from five farms. Paired t tests showed that affected lambs weighed approximately 10 per cent less than their unaffected controls for a period of at least five weeks following the start of the outbreak. The effects were highly significant whether the orf lesions affected the mouth or were found elsewhere on the body. If a lamb had orf, then there was a 82 per cent chance that its mother also had orf on its udder or teats. The financial consequences of orf in young lambs were estimated using average UK figures and conservative assumptions based on the results of this study.
Muscle cellular properties in the ice hockey player: a model for investigating overtraining?
Authors: Green Howard J. , Batada Aziz , Cole Bill , Burnett Margaret E. , Kollias Helen , McKay Scott , Roy Brian , Schertzer Jonathan D. , Smith Ian C. , Tupling Susan
Published: May 2012

In this study, we hypothesized that athletes involved in 5–6 months of sprint-type training would display higher levels of proteins and processes involved in muscle energy supply and utilization. Tissue was sampled from the vastus lateralis of 13 elite ice hockey players (peak oxygen consumption = 51.8 ± 1.3 mL·kg–1·min–1; mean ± standard error) at the end of a season (POST) and compared with samples from 8 controls (peak oxygen consumption = 45.5 ± 1.4 mL·kg–1·min–1) (CON). Compared with CON, higher activities were observed in POST (p < 0.05) only for succinic dehydrogenase (3.32 ± 0.16 mol·(mg protein)–1·min–1 vs. 4.10 ± 0.11 mol·(mg protein)–1·min–1) and hexokinase (0.73 ± 0.05 mol·(mg protein)–1·min–1 vs. 0.90 ± 0.05mol·(mg protein)–1·min–1) but not for phosphorylase, phosphofructokinase, and creatine phosphokinase. No differences were found in Na+,K+-ATPase concentration (βmax: 262 ± 36 pmol·(g wet weight)–1 vs. 275 ± 27 pmol·(g wet weight)–1) and the maximal activity of the sarcoplasmic reticulum Ca2+-ATPase (98.1 ± 6.1 µmol·(g protein)–1·min–1 vs. 102 ± 3.3 µmol·(g protein)–1·min–1). Cross-sectional area was lower (p < 0.05) in POST but only for the type IIA fibres (6312 ± 684 μm2 vs. 5512 ± 335 μm2), while the number of capillary counts per fibre and the capillary to fibre area ratio were generally higher (p < 0.05). These findings suggest that elite trained ice hockey players display elevations only in support of glucose-based aerobic metabolism that occur in the absence of alterations in excitation–contraction processes.
Oxygen absorption by skin exposed to oxygen supersaturated water
Authors: Reading Stacey A. , Yeomans Maggie
Published: May 2012

The present study tests the hypothesis that skin on the plantar surface of the foot absorbs oxygen (O2) when immersed in water that has a high dissolved O2 content. Healthy male and female subjects (24.2 ± 1.4 years) soaked each foot in tap water (1.7 ± 0.1 mg O2·L–1; 30.7 ± 0.3 °C) or O2-infused water (50.2 ± 1.7 mg O2·L–1; 32.1 ± 0.5 °C) for up to 30 min in 50 different experiments. Transcutaneous oximetry and near infrared spectroscopy were used to evaluate changes in skin PO2, oxygenated haemoglobin, and cytochrome oxidase aa3 that resulted from treatment. Compared with the tap water condition, tissue oxygenation index was 3.5% ± 1.3% higher in feet treated for 30 min with O2-infused water. This effect persisted after treatment, as skin PO2 was higher in feet treated with O2-infused water at 2 min (237 ± 9 vs. 112 ± 5 mm HG) and 15 min (131 ± 1 vs. 87 ± 4 mm HG) post-treatment. When blood flow to the foot was occluded for 5 min, feet resting in O2-infused water maintained a 3-fold higher O2 consumption rate than feet treated with tap water (9.1 ± 1.4 vs. 3.0 ± 1.0 µL·100 g–1·min–1). We estimate that skin absorbs 4.5 mL of O2·m–2·min–1 from O2-infused water. Thus, skin absorbs appreciable amounts of O2 from O2-infused water. This finding may prove useful and assist development of treatments targeting skin diseases with ischemic origin.
Grape seed and skin extract mitigates garlic-induced oxidative stress in rat liver
Authors: Hamlaoui-Gasmi Sonia , Mokni Meherzia , Limam Nadia , N’guessan Prudence , Carrier Alice , Limam Ferid , Amri Mohamed , Aouani Ezzedine , Marzouki Lamjed
Published: May 2012

Garlic is a commonly used spice in folk medicine that can exert adverse health effects when given at a high dose. Grape seed and skin extract (GSSE) exhibits a variety of beneficial effects even at a high dose. In the present study we evaluated the toxicity of high-dose garlic treatment on liver and the protective effect of GSSE. Rats were intraperitoneally administered either with garlic extract (5 g·(kg body weight)–1) or GSSE (500 mg·(kg body weight)–1) or a combination of garlic and GSSE at the same doses daily for 1 month. Plasma and hepatic levels of cholesterol, triacylglycerol, and transaminases and liver antioxidant status were evaluated. Data showed that a high garlic dose induced liver toxicity and a pro-oxidative status characterized by increased malondialdehyde and decreased antioxidant enzyme activities as catalase, peroxidase, and superoxide dismutase. Garlic increased intracellular H2O2but decreased free iron and Ca2+. GSSE alone or in co-treatment with garlic had the reverse effect and counteracted almost all garlic-induced deleterious impacts to near control levels. In conclusion, a high garlic dose induced a pro-oxidative state characterized by the Fenton reaction between H2O2and free iron, inducing Ca2+depletion, while GSSE exerted antioxidant properties and Ca2+repletion.
Effects of swimming training on tissue glycogen content in experimental thyrotoxic rats
Authors: Ribeiro Luiz Fernando Paulino , Teixeira Inaian Pignatti , Aparecido da Silva Glaucio , Dalia Rodrigo Augusto , Júnior Marcelo Costa , Bertolini Natalia Oliveira , Rostom de Mello Maria Alice , Luciano Eliete
Published: May 2012

Thyrotoxicosis, a condition in which there is an excessive amount of circulating thyroid hormones, leads to reduced glycogen content in different tissues. In this study we analyzed the effects of aerobic swimming training on liver, heart, and skeletal muscle glycogen content in experimentally induced thyrotoxicosis. Wistar male rats were divided into euthyroid sedentary (ES, n = 12), euthyroid trained (ET, n = 11), thyrotoxic sedentary (TS, n = 12), and thyrotoxic trained (TT, n = 10) groups. Thyrotoxic groups received daily i.p. doses of T4 (sodium levothyroxine, 25 µg/100 g body mass) through the experimental period, and trained groups swam for 1 h at 80% of the aerobic–anaerobic transition intensity, 5 days/week for 4 weeks. Heart and liver glycogen stores were ∼30% lower in T4 treated compared with nontreated groups, but were not changed by training status. On the other hand, glycogen content in mixed fiber type gastrocnemius of TT was 1.5- to 2.3-fold greater than those in other groups, whereas no significant differences were found for the slow soleus muscle. Increased gastrocnemius but not soleus, liver, or heart glycogen indicates that in mild long-term thyrotoxicosis chronic swimming affects glycogen stores in a tissue-specific manner.
Effect of chronic excess iodine intake on thyroid function and oxidative stress in hypothyroid rats
Authors: Hussein Abd El-Aziz M. , Abbas Amr M. , El Wakil Gehan A. , Elsamanoudy Ayman Z. , El Aziz Azza Abd
Published: May 2012

Our objective was to investigate the effects of chronic excess iodine intake on thyroid functions and thyroid oxidative stress state in hypothyroid rats. Sixty rats were divided into euthyroid and hypothyroid (thiocyanate-induced) groups with or without administration of excess iodine (3000 or 6000 μg/L) for 8 weeks. Serum thyroxine (T4), triiodothyronine (T3), thyroid-stimulating hormone (TSH), thyroid antioxidants (catalase, superoxide dismutase enzymes, and total antioxidants), and lipid peroxide (malondialdehyde; MDA) were measured. Reverse transcription – PCR gene expression for thyroidal Na+/I– symporter (NIS), D1 deiodinase, and thyroid peroxidase (TPO) were performed. Thiocyanate significantly decreased thyroid hormones (T3, T4), increased lipid peroxides and antioxidants, and increased gene expression of NIS, D1 deiodinase, and TPO. Excess iodine intake in hypothyroid rats increased T3 and T4. Also, high iodine intake by hypothyroid rats significantly decreased NIS, D1 deiodinase, and TPO genes expression. Excess iodine significantly increased MDA and antioxidants in euthyroid and hypothyroid rats. In conclusion, thiocyanate-hypothyroidism increases gene expression of NIS, TPO, and TPO and induces oxidative stress. High iodine intake decreases NIS and D1 deiodinase gene expression in hypothyroid rats. Moreover, excess iodine increase thyroid hormones, lipid peroxides, and antioxidants in hypothyroid rats.
Salusin-β accelerates inflammatory responses in vascular endothelial cells via NF-κB signaling in LDL receptor-deficient mice in vivo and HUVECs in vitro
Authors: Koya Takayuki , Miyazaki Takuro , Watanabe Takuya , Shichiri Masayoshi , Atsumi Takashi , Kim-Kaneyama Joo-ri , Miyazaki Akira
Published: May 2012

The bioactive peptide salusin-β is highly expressed in human atheromas; additionally, infusion of antiserum against salusin-β suppresses the development of atherosclerosis in atherogenic mice. This study examined the roles of salusin-β in vascular inflammation during atherogenesis. Infusion of antiserum against salusin-β attenuated the induction of VCAM-1, monocyte chemoattractant protein (MCP)-1, and IL-1β and as well as nuclear translocation of NF-κB in aortic endothelial cells (ECs) of LDL receptor-deficient mice, which led to the prevention of monocyte adhesion to aortic ECs. In vitro experiments indicated that salusin-β directly enhances the expression levels of proinflammatory molecules, including VCAM-1, MCP-1, IL-1β, and NADPH oxidase 2, as well as THP-1 monocyte adhesion to cultured human umbilical vein ECs (HUVECs). Both salusin-β-induced VCAM-1 induction and monocyte/HUVEC adhesion were suppressed by pharmacological inhibitors of NF-κB, e.g., Bay 11-7682 and curcumin. Furthermore, the VCAM-1 induction was significantly prevented by the phosphatidylinositol 3-kinase (PI3K) inhibitor LY-294002, whereas it was accelerated by the ERK inhibitor, U-0126. Treatment of HUVECs with salusin-β, but not with salusin-α, accelerated oxidative stress and nuclear translocation of NF-κB as well as phosphorylation and degradation of IκB-α, an endogenous inhibitor of NF-κB. Thus, salusin-β enhanced monocyte adhesion to vascular ECs through NF-κB-mediated inflammatory responses in ECs, which can be modified by PI3K or ERK signals. These findings are suggestive of a novel role of salusin-β in atherogenesis.
Adiponectin abates diabetes-induced endothelial dysfunction by suppressing oxidative stress, adhesion molecules, and inflammation in type 2 diabetic mice
Authors: Lee Sewon , Zhang Hanrui , Chen Jianping , Dellsperger Kevin C. , Hill Michael A. , Zhang Cuihua
Published: May 2012

Adiponectin (APN) can confer protection against metabolism-related illnesses in organs such as fat, the liver, and skeletal muscle. However, it is unclear whether APN improves endothelial-dependent nitric oxide-mediated vasodilation in type 2 diabetes and, if so, by what mechanism. We tested whether exogenous APN delivery improves endothelial function in type 2 diabetic mice and explored the mechanisms underlying the observed improvement. To test the hypothesis, we injected adenovirus APN (Ad-APN) or adenovirus β-galactosidase (Ad-βgal; control virus) via the tail vein in control (m Leprdb) and diabetic (Leprdb; db/ db) mice and studied vascular function of the aorta ex vivo. Ad-APN improved endothelial-dependent vasodilation in db/ db mice compared with Ad-βgal, whereas Ad-APN had no further improvement on endothelial function in control mice. This improvement was completely inhibited by a nitric oxide synthase inhibitor ( NG-nitro-l-arginine methyl ester). Serum triglyceride and total cholesterol levels were increased in db/ db mice, and Ad-APN significantly reduced triglyceride levels but not total cholesterol levels. Immunoblot results showed that interferon-γ, gp91phox, and nitrotyrosine were markedly increased in the aorta of db/ db mice. Ad-APN treatment decreased the expression of these proteins. In addition, mRNA expression of TNF-α, IL-6, and ICAM-1 was elevated in db/ db mice, and Ad-APN treatment decreased these expressions in the aorta. Our findings suggest that APN may contribute to an increase in nitric oxide bioavailability by decreasing superoxide production as well as by inhibiting inflammation and adhesion molecules in the aorta in type 2 diabetic mice.
Subharmonic microbubble emissions for noninvasively tracking right ventricular pressures
Authors: Dave Jaydev K. , Halldorsdottir Valgerdur G. , Eisenbrey John R. , Raichlen Joel S. , Liu Ji-Bin , McDonald Maureen E. , Dickie Kris , Wang Shumin , Leung Corina , Forsberg Flemming
Published: May 2012

Right heart catheterization is often required to monitor intra-cardiac pressures in a number of disease states. Ultrasound contrast agents can produce pressure modulated subharmonic emissions that may be used to estimate right ventricular (RV) pressures. A technique based on subharmonic acoustic emissions from ultrasound contrast agents to track RV pressures noninvasively has been developed and its clinical potential evaluated. The subharmonic signals were obtained from the aorta, RV, and right atrium (RA) of five anesthetized closed-chest mongrel dogs using a SonixRP ultrasound scanner and PA4-2 phased array. Simultaneous pressure measurements were obtained using a 5-French solid state micromanometer tipped catheter. Initially, aortic subharmonic signals and systemic blood pressures were used to obtain a calibration factor in units of millimeters of mercury per decibel. This factor was combined with RA pressures (that can be obtained noninvasively) and the acoustic data from the RV to obtain RV pressure values. The individual calibration factors ranged from −2.0 to −4.0 mmHg/dB. The subharmonic signals tracked transient changes in the RV pressures within an error of 0.6 mmHg. Relative to the catheter pressures, the mean errors in estimating RV peak systolic and minimum diastolic pressures, and RV relaxation [isovolumic negative derivative of change in pressure over time (−dP/d t)] by use of the subharmonic signals, were −2.3 mmHg, −0.8 mmHg, and 2.9 mmHg/s, respectively. Overall, acoustic estimates of RV peak systolic and minimum diastolic pressures and RV relaxation were within 3.4 mmHg, 1.8 mmHg, and 5.9 mmHg/s, respectively, of the measured pressures. This pilot study demonstrates that subharmonic emissions from ultrasound contrast agents have the potential to noninvasively track in vivo RV pressures with errors below 3.5 mmHg.
The α2 isoform of the Na,K-pump is important for intercellular communication, agonist-induced contraction, and EDHF-like response in rat mesenteric arteries
Authors: Matchkov Vladimir V. , Moeller-Nielsen Nina , Dam Vibeke Secher , Nourian Zahra , Briggs Boedtkjer Donna M. , Aalkjaer Christian
Published: May 2012

The specific role of different isoforms of the Na,K-pump in the vascular wall is still under debate. We have previously suggested that the α2 isoform of the Na,K-pump (α2), Na+, Ca2+-exchange (NCX), and connexin43 form a regulatory microdomain in smooth muscle cells (SMCs), which controls intercellular communication and contractile properties of the vascular wall. We have tested this hypothesis by downregulating α2 in cultured SMCs and in small arteries with siRNA in vivo. Intercellular communication was assessed by using membrane capacitance measurements. Arteries transfected in vivo were tested for isometric and isobaric force development in vitro; [Ca2+]i was measured simultaneously. Cultured rat SMCs were well-coupled electrically, but 10 μM ouabain uncoupled them. Downregulation of α2 reduced electrical coupling between SMCs and made them insensitive to ouabain. Downregulation of α2 in small arteries was accompanied with significant reduction in NCX expression. Acetylcholine-induced relaxation was not different between the groups, but the endothelium-dependent hyperpolarizing factor-like component of the response was significantly diminished in α2-downregulated arteries. Micromolar ouabain reduced in a concentration-dependent manner the amplitude of norepinephrine (NE)-induced vasomotion. Sixty percent of the α2-downregulated arteries did not have vasomotion, and vasomotion in the remaining 40% was ouabain insensitive. Although ouabain increased the sensitivity to NE in the control arteries, it had no effect on α2-downregulated arteries. In the presence of a low NE concentration the α2-downregulated arteries had higher [Ca2+]i and tone. However, the NE EC50 was reduced under isometric conditions, and maximal contraction was reduced under isometric and isobaric conditions. The latter was caused by a reduced Ca2+-sensitivity. The α2-downregulated arteries also had reduced contraction to vasopressin, whereas the contractile response to high K+ was not affected. Our results demonstrate the importance of α2 for intercellular coupling in the vascular wall and its involvement in the regulation of vascular tone.
Increasing pulse wave velocity in a realistic cardiovascular model does not increase pulse pressure with age
Authors: Mohiuddin Mohammad W. , Rihani Ryan J. , Laine Glen A. , Quick Christopher M.
Published: May 2012

The mechanism of the well-documented increase in aortic pulse pressure (PP) with age is disputed. Investigators assuming a classical windkessel model believe that increases in PP arise from decreases in total arterial compliance ( Ctot) and increases in total peripheral resistance ( Rtot) with age. Investigators assuming a more sophisticated pulse transmission model believe PP rises because increases in pulse wave velocity ( cph) make the reflected pressure wave arrive earlier, augmenting systolic pressure. It has recently been shown, however, that increases in cph do not have a commensurate effect on the timing of the reflected wave. We therefore used a validated, large-scale, human arterial system model that includes realistic pulse wave transmission to determine whether increases in cph cause increased PP with age. First, we made the realistic arterial system model age dependent by altering cardiac output (CO), Rtot, Ctot, and cph to mimic the reported changes in these parameters from age 30 to 70. Then, cph was theoretically maintained constant, while Ctot, Rtot, and CO were altered. The predicted increase in PP with age was similar to the observed increase in PP. In a complementary approach, Ctot, Rtot, and CO were theoretically maintained constant, and cph was increased. The predicted increase in PP was negligible. We found that increases in cph have a limited effect on the timing of the reflected wave but cause the system to degenerate into a windkessel. Changes in PP can therefore be attributed to a decrease in Ctot.
Acid contact in the rodent pulmonary alveolus causes proinflammatory signaling by membrane pore formation
Authors: Westphalen Kristin , Monma Eiji , Islam Mohammad N. , Bhattacharya Jahar
Published: May 2012

Although gastric acid aspiration causes rapid lung inflammation and acute lung injury, the initiating mechanisms are not known. To determine alveolar epithelial responses to acid, we viewed live alveoli of the isolated lung by fluorescence microscopy, then we microinjected the alveoli with HCl at pH of 1.5. The microinjection caused an immediate but transient formation of molecule-scale pores in the apical alveolar membrane, resulting in loss of cytosolic dye. However, the membrane rapidly resealed. There was no cell damage and no further dye loss despite continuous HCl injection. Concomitantly, reactive oxygen species (ROS) increased in the adjacent perialveolar microvascular endothelium in a Ca2+-dependent manner. By contrast, ROS did not increase in wild-type mice in which we gave intra-alveolar injections of polyethylene glycol (PEG)-catalase, in mice overexpressing alveolar catalase, or in mice lacking functional NADPH oxidase (Nox2). Together, our findings indicate the presence of an unusual proinflammatory mechanism in which alveolar contact with acid caused membrane pore formation. The effect, although transient, was nevertheless sufficient to induce Ca2+entry and Nox2-dependent H2O2release from the alveolar epithelium. These responses identify alveolar H2O2release as the signaling mechanism responsible for lung inflammation induced by acid and suggest that intra-alveolar PEG-catalase might be therapeutic in acid-induced lung injury.
IQGAP1 is necessary for pulmonary vascular barrier protection in murine acute lung injury and pneumonia
Authors: Bhattacharya M. , Su G. , Su X. , Oses-Prieto J. A. , Li J. T. , Huang X. , Hernandez H. , Atakilit A. , Burlingame A. L. , Matthay M. A. , Sheppard D.
Published: May 2012

We recently reported that integrin αvβ3 is necessary for vascular barrier protection in mouse models of acute lung injury and peritonitis. Here, we used mass spectrometric sequencing of integrin complexes to isolate the novel β3-integrin binding partner IQGAP1. Like integrin β3, IQGAP1 localized to the endothelial cell-cell junction after sphingosine-1-phosphate (S1P) treatment, and IQGAP1 knockdown prevented cortical actin formation and barrier enhancement in response to S1P. Furthermore, knockdown of IQGAP1 prevented localization of integrin αvβ3 to the cell-cell junction. Similar to β3-null animals, IQGAP1-null mice had increased pulmonary vascular leak compared with wild-type controls 3 days after intratracheal LPS. In an Escherichia coli pneumonia model, IQGAP1 knockout mice had increased lung weights, lung water, and lung extravascular plasma equivalents of 125I-labeled albumin compared with wild-type controls. Taken together, these experiments indicate that IQGAP1 is necessary for S1P-mediated vascular barrier protection during acute lung injury and is required for junctional localization of the barrier-protective integrin αvβ3.