bluuebunny/crossref_metadata_2025 huggingface dataset:
FeoB2 Functions in Magnetosome Formation and Oxidative Stress Protection in Magnetospirillum gryphiswaldense Strain MSR-1
Authors: Rong Chengbo , Zhang Chan , Zhang Yiting , Qi Lei , Yang Jing , Guan Guohua , Li Ying , Li Jilun
Published: May 2012

Magnetotactic bacteria (MTB) synthesize unique organelles, the magnetosomes, which are intracellular nanometer-sized, membrane-enveloped magnetite. The biomineralization of magnetosomes involves the uptake of large amounts of iron. However, the iron metabolism of MTB is not well understood. The genome of the magnetotactic bacterium
Magnetospirillum gryphiswaldense
strain MSR-1 contains two ferrous iron transport genes,
feoB1
and
feoB2
. The FeoB1 protein was reported to be responsible mainly for the transport of ferrous iron and to play an accessory role in magnetosome formation. To determine the role of
feoB2
, we constructed an
feoB2
deletion mutant (MSR-1 Δ
feoB2
) and an
feoB1 feoB2
double deletion mutant (MSR-1 N
feoB
). The single
feoB2
mutation did not affect magnetite crystal biomineralization. MSR-1 N
feoB
had a significantly lower average magnetosome number per cell (∼65%) than MSR-1 Δ
feoB1
, indicating that FeoB2 plays a role in magnetosome formation when the
feoB1
gene is deleted. Our findings showed that FeoB1 has a greater ferrous iron transport ability than FeoB2 and revealed the differential roles of FeoB1 and FeoB2 in MSR-1 iron metabolism. Interestingly, compared to the wild type, the
feoB
mutants showed increased sensitivity to oxidative stress and lower activities of the enzymes superoxide dismutase and catalase, indicating that the FeoB proteins help protect bacterial cells from oxidative stress.
Expanded Roles for Multicargo and Class 1B Effector Chaperones in Type III Secretion
Authors: Thomas Nikhil A. , Ma Irene , Prasad Madhulika E. , Rafuse Cheryl
Published: May 2012

Bacterial type III secretion systems (T3SS) are complex protein assemblies that mediate the secretion of protein substrates outside the cell. Type III secretion chaperones (T3SC) are always found associated with T3SS, and they serve in multiple roles to ensure that protein substrates are efficiently targeted for secretion. Bacterial pathogens with T3SS express T3SC proteins that bind effectors, a process important for effector protein delivery into eukaryotic cells during infection. In this minireview, we focus on multicargo and class 1B T3SC that associate with effectors within significant pathogens of animals and plants. As a primary role, multicargo and class 1B T3SC form homodimers and specifically bind different effectors within the cytoplasm, maintaining the effectors in a secretion-competent state. This role makes T3SC initial and central contributors to effector-mediated pathogenesis. Recent findings have greatly expanded our understanding of cellular events linked to multicargo T3SC function. New binding interactions with T3SS components have been reported in different systems, thereby implicating multicargo T3SC in critical roles beyond effector binding. Three notable interactions with the YscN, YscV, and YscQ family members are well represented in the literature. Similar T3SC interactions are reported in the putative related flagellar T3SS, suggesting that secretion mechanisms may be more similar than previously thought. The evidence implicates multicargo and class 1B T3SC in effector binding and stabilization, in addition to T3SS recruitment and docking events.
OmpA Is the Principal Nonspecific Slow Porin of Acinetobacter baumannii
Authors: Sugawara Etsuko , Nikaido Hiroshi
Published: May 2012

Acinetobacterspecies show high levels of intrinsic resistance to many antibiotics. The major protein species in the outer membrane ofAcinetobacter baumanniidoes not belong to the high-permeability trimeric porin family, which includesEscherichia coliOmpF/OmpC, and instead is a close homolog ofE. coliOmpA andPseudomonas aeruginosaOprF. We characterized the pore-forming function of this OmpA homolog, OmpAAb, by a reconstitution assay. OmpAAbproduced very low pore-forming activity, about 70-fold lower than that of OmpF and an activity similar to that ofE. coliOmpA andP. aeruginosaOprF. The pore size of the OmpAAbchannel was similar to that of OprF, i.e., about 2 nm in diameter. The low permeability of OmpAAbis not due to the inactivation of this protein during purification, because the permeability of the wholeA. baumanniiouter membrane was also very low. Furthermore, the outer membrane permeability to cephalothin and cephaloridine, measured in intact cells, was about 100-fold lower than that ofE. coliK-12. The permeability of cephalothin and cephaloridine inA. baumanniiwas decreased 2- to 3-fold when theompAAbgene was deleted. These results show that OmpAAbis the major nonspecific channel inA. baumannii. The low permeability of this porin, together with the presence of constitutive β-lactamases and multidrug efflux pumps, such as AdeABC and AdeIJK, appears to be essential for the high levels of intrinsic resistance to a number of antibiotics.
Genome Sequencing of a Genetically Tractable Pyrococcus furiosus Strain Reveals a Highly Dynamic Genome
Authors: Bridger Stephanie L. , Lancaster W. Andrew , Poole Farris L. , Schut Gerrit J. , Adams Michael W. W.
Published: May 2012

The model archaeon
Pyrococcus furiosus
grows optimally near 100°C on carbohydrates and peptides. Its genome sequence (NCBI) was determined 12 years ago. A genetically tractable strain, COM1, was very recently reported, and here we describe its genome sequence. Of 1,909,827 bp in size, it is 1,571 bp longer (0.1%) than the reference NCBI sequence. The COM1 genome contains numerous chromosomal rearrangements, deletions, and single base changes. COM1 also has 45 full or partial insertion sequences (ISs) compared to 35 in the reference NCBI strain, and these have resulted in the direct deletion or insertional inactivation of 13 genes. Another seven genes were affected by chromosomal deletions and are predicted to be nonfunctional. In addition, the amino acid sequences of another 102 of the 2,134 predicted gene products are different in COM1. These changes potentially impact various cellular functions, including carbohydrate, peptide, and nucleotide metabolism; DNA repair; CRISPR-associated defense; transcriptional regulation; membrane transport; and growth at 72°C. For example, the IS-mediated inactivation of riboflavin synthase in COM1 resulted in a riboflavin requirement for growth. Nevertheless, COM1 grew on cellobiose, malto-oligosaccharides, and peptides in complex and minimal media at 98 and 72°C to the same extent as did both its parent strain and a new culture collection strain (DSMZ 3638). This was in spite of COM1 lacking several metabolic enzymes, including nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase and beta-glucosidase. The
P. furiosus
genome is therefore of high plasticity, and the availability of the COM1 sequence will be critical for the future studies of this model hyperthermophile.
Bacterium-Generated Nitric Oxide Hijacks Host Tumor Necrosis Factor Alpha Signaling and Modulates the Host Cell Cycle
In Vitro
Authors: Mocca Brian , Wang Wei
Published: May 2012

In mammalian cells, nitric oxide (NO·) is an important signal molecule with concentration-dependent and often controversial functions of promoting cell survival and inducing cell death. An inducible nitric oxide synthase (iNOS) in various mammalian cells produces higher levels of NO· from
l
-arginine upon infections to eliminate pathogens. In this study, we reveal novel pathogenic roles of NO· generated by bacteria in bacterium-host cell cocultures using
Moraxella catarrhalis
, a respiratory tract disease-causing bacterium, as a biological producer of NO·. We recently demonstrated that
M. catarrhalis
cells that express the nitrite reductase (AniA protein) can produce NO· by reducing nitrite. Our study suggests that, in the presence of pathophysiological levels of nitrite, this opportunistic pathogen hijacks host cell signaling and modulates host gene expression through its ability to produce NO· from nitrite. Bacterium-generated NO· significantly increases the secretion of tumor necrosis factor alpha (TNF-α) and modulates the expression of apoptotic proteins, therefore triggering host cell programmed death partially through TNF-α signaling. Furthermore, our study reveals that bacterium-generated NO· stalls host cell division and directly results in the death of dividing cells by reducing the levels of an essential regulator of cell division. This study provides unique insight into why NO· may exert more severe cytotoxic effects on fast growing cells, providing an important molecular basis for NO·-mediated pathogenesis in infections and possible therapeutic applications of NO·-releasing molecules in tumorigenesis. This study strongly suggests that bacterium-generated NO· can play important pathogenic roles during infections.
Role of the Fused Corrinoid/Methyl Transfer Protein CmtA during CO-Dependent Growth of Methanosarcina acetivorans
Authors: Vepachedu Venkata R. , Ferry James G.
Published: May 2012

The genome of
Methanosarcina acetivorans
encodes three homologs, initially annotated as hypothetical fused corrinoid/methyl transfer proteins, which are highly elevated in CO-grown cells versus cells grown with alternate substrates. Based only on phenotypic analyses of deletion mutants, it was previously concluded that the homologs are strictly dimethylsulfide:coenzyme M (CoM) methyltransferases not involved in the metabolism of CO (E. Oelgeschlager and M. Rother, Mol. Microbiol. 72:1260 –1272, 2009). The homolog encoded by MA4383 (here designated CmtA) was reexamined via biochemical characterization of the protein overproduced in
Escherichia coli
. Purified CmtA reconstituted with methylcob(III)alamin contained a molar ratio of cobalt to protein of 1.0 ± 0.2. The UV-visible spectrum was typical of methylated corrinoid-containing proteins, with absorbance maxima at 370 and 420 nm and a band of broad absorbance between 450 and 600 nm with maxima at 525, 490, and 550 nm. CmtA reconstituted with aquocobalamin showed methyl-tetrahydromethanopterin:CoM (CH
3
-THMPT:HS-CoM) methyltransferase activity (0.31 μmol/min/mg) with apparent

K
m

values of 135 μM for CH
3
-THMPT and 277 μM for HS-CoM. The ratio of CH
3
-THMPT:HS-CoM methyltransferase activity in the soluble versus membrane cellular fractions was 15-fold greater in CO-grown versus methanol-grown cells. A mutant strain deleted for the CmtA gene showed lower growth rates and final yields when cultured with growth-limiting partial pressures of CO, demonstrating a role for CmtA during growth with this substrate. The results establish that CmtA is a soluble CH
3
-THSPT:HS-CoM methyltransferase postulated to supplement the membrane-bound CH
3
-THMPT:HS-CoM methyltransferase during CO-dependent growth of
M. acetivorans
. Thus, we propose that the name of the enzyme encoded by MA4384 be CmtA (for
c
ytoplasmic
m
ethyl
t
ransferase).
Enterococcus faecalis PrgJ, a VirB4-Like ATPase, Mediates pCF10 Conjugative Transfer through Substrate Binding
Authors: Li Feng , Alvarez-Martinez Cristina , Chen Yuqing , Choi Kyoung-Jae , Yeo Hye-Jeong , Christie Peter J.
Published: May 2012

The
Enterococcus faecalis prg
and
pcf
genes of plasmid pCF10 encode a type IV secretion system (T4SS) required for conjugative transfer. PrgJ is a member of the VirB4 family of ATPases that are universally associated with T4SSs. Here, we report that purified PrgJ dimers displayed ATP binding and hydrolysis activities. A PrgJ nucleoside triphosphate (NTP) binding site mutation (K471E) slightly diminished ATP binding but abolished ATP hydrolysis
in vitro
and blocked pCF10 transfer
in vivo
. As shown with affinity pulldown assays, PrgJ and the K471E mutant protein interacted with the substrate receptor PcfC and with relaxase PcfG and accessory factor PcfF, which together form the relaxosome at the
oriT
sequence to initiate plasmid processing. The purified PrgJ and K471E proteins also bound single- and double-stranded DNA substrates without sequence specificity
in vitro
, and both PrgJ derivatives bound pCF10
in vivo
by a mechanism dependent on an intact
oriT
sequence and cosynthesis of PcfC, PcfF, and PcfG, as shown by a formaldehyde-cross-linking assay. Our findings support a model in which the PcfC receptor coordinates with the PrgJ ATPase to drive early steps of pCF10 processing/transfer: (i) PcfC first binds the pCF10 relaxosome through contacts with PcfF, PcfG, and DNA; (ii) PcfC delivers the plasmid substrate to PrgJ; and (iii) PrgJ catalyzes substrate transfer to the membrane translocase. Substrate engagement with a VirB4-like subunit has not been previously described; consequently, our studies point to a novel function for these signature T4SS ATPases in mediating early steps of type IV secretion.
cis
-Acting Elements That Control Expression of the Master Virulence Regulatory Gene
atxA
in Bacillus anthracis
Authors: Dale Jennifer L. , Raynor Malik J. , Dwivedi Prabhat , Koehler Theresa M.
Published: May 2012

Transcription of the
Bacillus anthracis
structural genes for the anthrax toxin proteins and biosynthetic operon for capsule is positively regulated by AtxA, a transcription regulator with unique properties. Consistent with the role of
atxA
in virulence factor expression, a
B. anthracis atxA
-null mutant is avirulent in a murine model for anthrax. In culture, multiple signals impact
atxA
transcript levels, and the timing and steady-state level of
atxA
expression are critical for optimal toxin and capsule synthesis. Despite the apparent complex control of
atxA
transcription, only one
trans
-acting protein, the transition state regulator AbrB, has been demonstrated to interact directly with the
atxA
promoter. Here we employ 5′ and 3′ deletion analysis and site-directed mutagenesis of the
atxA
control region to demonstrate that
atxA
transcription from the major start site P1 is dependent upon a consensus sequence for the housekeeping sigma factor SigA and an A+T-rich upstream element for RNA polymerase. We also show that an additional
trans
-acting protein(s) binds specifically to
atxA
promoter sequences located between −13 and +36 relative to P1 and negatively impacts transcription. Deletion of this region increases promoter activity up to 15-fold. Site-directed mutagenesis of a 9-bp palindromic sequence within the region prevents binding of the
trans
-acting protein(s), increasing promoter activity 7-fold and resulting in a corresponding increase in AtxA and anthrax toxin production. Notably, an
atxA
promoter mutant that produced elevated levels of AtxA and toxin proteins during culture was unaffected for virulence in a murine model for anthrax.
Characterization of the P
IB
-Type ATPases Present in Thermus thermophilus
Authors: Schurig-Briccio Lici A. , Gennis Robert B.
Published: May 2012

P
IB
-type ATPases transport heavy metals (Cu
2+
, Cu
+
, Ag
+
, Zn
2+
, Cd
2+
, Co
2+
) across biomembranes, playing a key role in homeostasis and in the mechanisms of biotolerance of these metals. Three genes coding for putative P
IB
-type ATPases are present in the genome of
Thermus thermophilus
(HB8 and HB27): the TTC1358, TTC1371, and TTC0354 genes; these genes are annotated, respectively, as two copper transporter (CopA and CopB) genes and a zinc-cadmium transporter (Zn
2+
/Cd
2+
-ATPase) gene. We cloned and expressed the three proteins with 8His tags using a
T. thermophilus
expression system. After purification, each of the proteins was shown to have phosphodiesterase activity at 65°C with ATP and
p
-nitrophenyl phosphate (
p
NPP) as substrates. CopA was found to have greater activity in the presence of Cu
+
, while CopB was found to have greater activity in the presence of Cu
2+
. The putative Zn
2+
/Cd
2+
-ATPase was truncated at the N terminus and was, surprisingly, activated
in vitro
by copper but not by zinc or cadmium. When expressed in
Escherichia coli
, however, the putative Zn
2+
/Cd
2+
-ATPase could be isolated as a full-length protein and the ATPase activity was increased by the addition of Zn
2+
and Cd
2+
as well as by Cu
+
. Mutant strains in which each of the three P-type ATPases was deleted singly were constructed. In each case, the deletion increased the sensitivity of the strain to growth in the presence of copper in the medium, indicating that each of the three can pump copper out of the cells and play a role in copper detoxification.
Pathway and Enzyme Redundancy in Putrescine Catabolism in Escherichia coli
Authors: Schneider Barbara L. , Reitzer Larry
Published: May 2012

Putrescine as the sole carbon source requires a novel catabolic pathway with glutamylated intermediates. Nitrogen limitation does not induce genes of this glutamylated putrescine (GP) pathway but instead induces genes for a putrescine catabolic pathway that starts with a transaminase-dependent deamination. We determined pathway utilization with putrescine as the sole nitrogen source by examining mutants with defects in both pathways. Blocks in both the GP and transaminase pathways were required to prevent growth with putrescine as the sole nitrogen source. Genetic and biochemical analyses showed redundant enzymes for γ-aminobutyraldehyde dehydrogenase (PatD/YdcW and PuuC), γ-aminobutyrate transaminase (GabT and PuuE), and succinic semialdehyde dehydrogenase (GabD and PuuC). PuuC is a nonspecific aldehyde dehydrogenase that oxidizes all the aldehydes in putrescine catabolism. A
puuP
mutant failed to use putrescine as the nitrogen source, which implies one major transporter for putrescine as the sole nitrogen source. Analysis of regulation of the GP pathway shows induction by putrescine and not by a product of putrescine catabolism and shows that putrescine accumulates in
puuA
,
puuB
, and
puuC
mutants but not in any other mutant. We conclude that two independent sets of enzymes can completely degrade putrescine to succinate and that their relative importance depends on the environment.
FdhTU-Modulated Formate Dehydrogenase Expression and Electron Donor Availability Enhance Recovery ofCampylobacter jejunifollowing Host Cell Infection
Authors: Pryjma Mark , Apel Dmitry , Huynh Steven , Parker Craig T. , Gaynor Erin C.
Published: May 2012

Campylobacter jejuniis a food-borne bacterial pathogen that colonizes the intestinal tract and causes severe gastroenteritis. Interaction with host epithelial cells is thought to enhance severity of disease, and the ability ofC. jejunito modulate its metabolism in differentin vivoand environmental niches contributes to its success as a pathogen. AC. jejunioperon comprising two genes that we designatedfdhT(CJJ81176_1492) andfdhU(CJJ81176_1493) is conserved in many bacterial species. Deletion offdhTorfdhUinC. jejuniresulted in apparent defects in adherence and/or invasion of Caco-2 epithelial cells when assessed by CFU enumeration on standard Mueller-Hinton agar. However, fluorescence microscopy indicated that each mutant invaded cells at wild-type levels, instead suggesting roles for FdhTU in either intracellular survival or postinvasion recovery. The loss offdhUcaused reduced mRNA levels of formate dehydrogenase (FDH) genes and a severe defect in FDH activity. Cell infection phenotypes of a mutant deleted for the FdhA subunit of FDH and an ΔfdhUΔfdhAdouble mutant were similar to those of a ΔfdhUmutant, which likewise suggested that FdhU and FdhA function in the same pathway. Cell infection assays followed by CFU enumeration on plates supplemented with sodium sulfite abolished the ΔfdhUand ΔfdhAmutant defects and resulted in significantly enhanced recovery of all strains, including wild type, at the invasion and intracellular survival time points. Collectively, our data indicate that FdhTU and FDH are required for optimal recovery following cell infection and suggest thatC. jejunialters its metabolic potential in the intracellular environment.
Growth Phase-Dependent Modulation of Rgg Binding Specificity in Streptococcus pyogenes
Authors: Anbalagan Srivishnupriya , Dmitriev Alexander , McShan W. Michael , Dunman Paul M. , Chaussee Michael S.
Published: May 2012

Streptococcus pyogenes
Rgg is a transcriptional regulator that interacts with the cofactor LacD.1 to control growth phase-dependent expression of genes, including
speB
, which encodes a secreted cysteine protease. LacD.1 is thought to interact with Rgg when glycolytic intermediates are abundant in a manner that prevents Rgg-mediated activation of
speB
expression via binding to the promoter region. When the intermediates diminish, LacD.1 dissociates from Rgg and binds to the
speB
promoter to activate expression. The purpose of this study was to determine if Rgg bound to chromatin during the exponential phase of growth and, if so, to identify the binding sites. Rgg bound to 62 chromosomal sites, as determined by chromatin immunoprecipitation coupled with DNA microarrays. Thirty-eight were within noncoding DNA, including sites upstream of the genes encoding the M protein (M49), serum opacity factor (SOF), fibronectin-binding protein (SfbX49), and a prophage-encoded superantigen, SpeH. Each of these sites contained a promoter that was regulated by Rgg, as determined with transcriptional fusion assays. Purified Rgg also bound to the promoter regions of
emm49
,
sof
, and
sfbX49 in vitro
. Results obtained with a
lacD.1
mutant showed that both LacD.1 and Rgg were necessary for the repression of
emm49
,
sof
,
sfbX49
, and
speH
expression. Overall, the results indicated that the DNA binding specificity of Rgg is responsive to environmental changes in a LacD.1-dependent manner and that Rgg and LacD.1 directly control virulence gene expression in the exponential phase of growth.
Physical performance and training response during Ramadan observance, with particular reference to protein metabolism
Authors: Shephard Roy J
Published: May 2012

This review examines information on the effects of Ramadan observance upon the metabolism, training and performance of athletes, with particular reference to proteins and amino acids. Increased gluconeogenesis and/or a reduced intake of protein could lead to a decrease of lean tissue, with adverse effects on muscular performance, and the lack of immediate protein ingestion could compromise responses to strength training. Actual responses vary quite widely, depending on culture and the individual's level and type of athletic involvement. In elite competitors, there is typically an increased fractional ingestion of protein with a small reduction in overall energy intake, and this may lead to small reductions of body and lean tissue mass. There are often small decreases of performance, particularly in activities requiring vigorous and/or repetitive muscular contraction. More information is needed on responses in situations where protein intake is likely to be inadequate (adolescent growth, those maintaining vegetarian diets or from poor countries and disciplines with very high overall energy needs) and when vigorous muscle training is in progress. However, in most of the situations studied to date, Ramadan observance has had only limited adverse consequences for either training or competitive performance.
Illness during the 2010 Super 14 Rugby Union tournament – a prospective study involving 22 676 player days
Authors: Schwellnus Martin , Derman Wayne , Page Tony , Lambert Michael , Readhead Clint , Roberts Craig , Kohler Ryan , Jordaan Esme , Collins Robert , Kara Stephen , Morris Ian , Strauss Org , Webb Sandra
Published: May 2012

Background

Illness accounts for a significant proportion of consultations with a team physician travelling with elite athletes.

Objective

To determine the incidence, type, cause and consequences of illness in Rugby Union players participating in a 16-week tournament.

Setting

8 teams participating in the 2010 Super 14 Rugby tournament

Participants

A cohort of 259 elite rugby players from eight teams was recruited.

Assessmen

All players were followed daily over the 16-week competition period (22 676 player days). Each day, team physicians completed an illness log with 100% compliance. Information included the daily squad size and illness details including system affected, final diagnosis, type and onset of symptoms, training/match days lost and suspected cause.

Main outcome measurement

Incidence of illness (illness per 1000 player days).

Results

The incidence of illness in the cohort was 20.7/1000 player days (95% CI 18.5 to 23.1) with the highest incidence of illness in the respiratory system (6.4: 95% CI 5.5 to 7.3), gastrointestinal system (5.6: 95% CI 4.9 to 6.6) and the skin and subcutaneous tissue (4.6; 95% CI 4.0 to 5.4). Infections accounted for 54.5% of all illness and 26.1% of illness resulted in time loss of ≥1 day. In over 50% of illnesses, symptoms were present for ≥1 day before being reported to the team physician.

Conclusion

Infective illness involving the respiratory tract and gastrointestinal tract together with dermatological illness was common in elite rugby players participating in this international tournament. A delay in reporting of symptoms >24 h could have important clinical implications in player medical care.
Epidemiology of musculoskeletal injury in the tennis player
Authors: Abrams Geoffrey D , Renstrom Per A , Safran Marc R
Published: May 2012

Tennis is a popular sport with tens of millions of players participating worldwide. This popularity was one factor leading to the reappearance of tennis as a medal sport at the 1988 Summer Olympics in Seoul, South Korea. The volume of play, combined with the physical demands of the sports, can lead to injuries of the musculoskeletal system. Overall, injury incidence and prevalence in tennis has been reported in a number of investigations. The sport creates specific demands on the musculoskeletal system, with acute injuries, such as ankle sprains, being more frequent in the lower extremity while chronic overuse injuries, such as lateral epicondylitis, are more common in the upper extremity in the recreational player and shoulder pain more common in the high-level player. This review discusses the epidemiology of injuries frequently experienced in tennis players and examines some of these injuries' correlation with the development of osteoarthritis. In addition, player-specific factors, such as age, sex, volume of play, skill level, racquet properties and grip positions as well as the effect of playing surface on the incidence and prevalence of injury is reported. Finally, recommendations on standardisation of future epidemiological studies on tennis injuries are made in order to be able to more easily compare results of future investigations.
The economic benefit of hip replacement: a 5-year follow-up of costs and outcomes in the Exeter Primary Outcomes Study
Authors: Fordham Richard , Skinner Jane , Wang Xia , Nolan John ,   the Exeter Primary Outcome Study Group
Published: May 2012

Objectives

To assess changes in quality of life and costs of patients undergoing primary total hip replacement using the Exeter prosthesis compared with a hypothetical ‘no surgery’ group.

Design

The incremental quality of life, quality-adjusted life years (QALYs) and cost of Exeter Primary Outcomes Study patients was compared with hypothetical ‘no surgery’ group over 5 years. Scores from annual SF-36 assessments were converted into utility scores using an established algorithm and the QALY gains calculated from pre-operative baseline scores. Costs included implant costs and length of stay.

Setting

Secondary care hospitals.

Participants

Patients receiving a primary Exeter implant enrolled in five of seven Exeter Primary Outcomes Study centres.

Results

On average, patients gained around 0.8 QALYs over 5 years. Younger and male patients or those with lower body mass index and poorer Oxford Hip Scores were significantly associated with increased QALYs. Treatment costs for a primary episode of care were just over £5000 (95% CI £4588 to £5812) per patient. Compared with ‘no surgery’, the cost per QALY was £7182 (95% CI £6470 to £7678), and this remained stable when key cost parameters were varied. The most likely cost per QALY was between £7058 and £7220. Older patients (age 75+) cost more, mainly due to longer average hospital stays and had a higher cost per QALY, although this remained below £10 000.

Conclusions

85% of cases had a cost of <£20 000 per QALY (with 70% having a cost per QALY under £10 000) compared with no surgery. Cases would be considered cost-effective under currently accepted thresholds (£25 000–£30 000) compared with ‘no surgery’. However, depending on age and severity, younger patients and more severe patients had below average cost per QALYs. These results help to confirm the long-term benefits and cost-effectiveness of total hip replacement in a wide variety of patients using well-established implant models such as the Exeter. However, further and ongoing economic appraisal of this and other models is required for comparative purposes.
Registration of surgical adverse outcomes: a reliability study in a university hospital
Authors: Ubbink Dirk T , Visser Annelies , Gouma Dirk J , Goslings J Carel
Published: May 2012

Objective

Accurate registration of adverse surgical outcomes is essential to detect areas for improvement of surgical care quality. One reason for inaccurate adverse outcome registration may be the method to collect these outcomes. The authors compared the completeness of the national complication registry database (LHCR) as used in our hospital with relevant information from other available resources.

Design

Retrospective reliability analysis.

Setting

University hospital.

Participants

From the 3252 patients admitted to the surgical wards in 2010, the authors randomly selected a cohort of 180 cases, oversampling those with adverse outcomes. The LHCR contains adverse outcomes as reported during morning hand-offs or in discharge letters. The authors checked if the number and severity of adverse outcomes recorded in the LHCR agreed with those reported in morning hand-offs, discharge letters and medical and nursing files.

Results

In 135 of 180 patients, all resources could be retrieved completely. Fourteen per cent of the patients with adverse outcomes were not recorded in the LHCR. Missing adverse outcomes were all reversible without the need for (re)operation, for example, postoperative pain, delirium or urinary tract complications. Only 38% of these adverse outcomes were reported in the morning hand-offs and discharge letters but were best reported in the medical and nursing files.

Conclusions

Registration of surgical adverse outcomes appears largely depending on the reliability of the underlying sources. For a more complete adverse outcome registration, the authors advocate a better hand-off and additional consultation of the patient's dossier. This extra effort allows for improvement actions to eventually avoid ‘mild’ adverse outcomes patients perceive as important and undesirable.
Impact of a pharmacist-prepared interim residential care medication administration chart on gaps in continuity of medication management after discharge from hospital to residential care: a prospective pre- and post-intervention study (MedGap Study)
Authors: Elliott Rohan A , Tran Tim , Taylor Simone E , Harvey Penelope A , Belfrage Mary K , Jennings Rhonda J , Marriott Jennifer L
Published: May 2012

Objectives

To test the impact of a hospital pharmacist-prepared interim residential care medication administration chart (IRCMAC) on medication administration errors and use of locum medical services after discharge from hospital to residential care.

Design

Prospective pre-intervention and post-intervention study.

Setting

One major acute care hospital and one subacute aged-care hospital; 128 residential care facilities (RCF) in Victoria, Australia.

Participants

428 patients (median age 84 years, IQR 79–88) discharged to a RCF from an inpatient ward over two 12-week periods.

Intervention

Seven-day IRCMAC auto-populated with patient and medication data from the hospitals' pharmacy dispensing software, completed and signed by a hospital pharmacist and sent with the patient to the RCF.

Primary and secondary outcome measures

Primary end points were the proportion of patients with one or more missed or significantly delayed (>50% of prescribed dose interval) medication doses, and the proportion of patients whose RCF medication chart was written by a locum doctor, in the 24 h after discharge. Secondary end points included RCF staff and general practitioners' opinions about the IRCMAC.

Results

The number of patients who experienced one or more missed or delayed doses fell from 37/202 (18.3%) to 6/226 (2.7%) (difference in percentages 15.6%, 95% CI 9.5% to 21.9%, p<0.001). The number of patients whose RCF medication chart was written by a locum doctor fell from 66/202 (32.7%) to 25/226 (11.1%) (difference in percentages 21.6%, 95% CI 13.5% to 29.7%, p<0.001). For 189/226 (83.6%) discharges, RCF staff reported that the IRCMAC improved continuity of care; 31/35 (88.6%) general practitioners said that the IRCMAC reduced the urgency for them to attend the RCF and 35/35 (100%) said that IRCMACs should be provided for all patients discharged to a RCF.

Conclusions

A hospital pharmacist-prepared IRCMAC significantly reduced medication errors and use of locum medical services after discharge from hospital to residential care.
Social differences in lung cancer management and survival in South East England: a cohort study
Authors: Berglund Anders , Lambe Mats , Lüchtenborg Margreet , Linklater Karen , Peake Michael D , Holmberg Lars , Møller Henrik
Published: May 2012

Objective

To examine possible social variations in lung cancer survival and assess if any such gradients can be attributed to social differences in comorbidity, stage at diagnosis or treatment.

Design

Population-based cohort identified in the Thames Cancer Registry.

Setting

South East England.

Participants

15 582 lung cancer patients diagnosed between 2006 and 2008.

Main outcome measures

Stage at diagnosis, surgery, radiotherapy, chemotherapy and survival.

Results

The likelihood of being diagnosed as having early-stage disease did not vary by socioeconomic quintiles (p=0.58). In early-stage non-small-cell lung cancer, the likelihood of undergoing surgery was lowest in the most deprived group. There were no socioeconomic differences in the likelihood of receiving radiotherapy in stage III disease, while in advanced disease and in small-cell lung cancer, receipt of chemotherapy differed over socioeconomic quintiles (p<0.01). In early-stage disease and following adjustment for confounders, the HR between the most deprived and the most affluent group was 1.24 (95% CI 0.98 to 1.56). Corresponding estimates in stage III and advanced disease or small-cell lung cancer were 1.16 (95% CI 1.01 to 1.34) and 1.12 (95% CI 1.05 to 1.20), respectively. In early-stage disease, the crude HR between the most deprived and the most affluent group was approximately 1.4 and constant through follow-up, while in patients with advanced disease or small-cell lung cancer, no difference was detectable after 3 months.

Conclusion

We observed socioeconomic variations in management and survival in patients diagnosed as having lung cancer in South East England between 2006 and 2008, differences which could not fully be explained by social differences in stage at diagnosis, co-morbidity and treatment. The survival observed in the most affluent group should set the target for what is achievable for all lung cancer patients, managed in the same healthcare system.
Detailed protocol for the lifestyle intervention in the BeWEL randomised controlled trial of weight loss in adults who have had a colorectal adenoma
Authors: Caswell Stephen , Craigie Angela M , Wardle Jane , Stead Martine , Anderson Annie
Published: May 2012

Introduction

The BeWEL study is aimed at assessing the impact of a personalised lifestyle programme on body weight in people at risk of developing colorectal adenomas. The study is a two-arm multicentre randomised controlled trial comparing the BeWEL lifestyle programme against usual care. Over 12 months, 316 people who have had a colorectal adenoma removed through the national screening programme will be randomised to provide 80% power to detect a weight loss (primary outcome) of 7% over 12 months.

Methods

The 12-month intervention will be delivered by lifestyle counsellors via three face-to-face visits followed by nine monthly telephone support calls. Consultant endorsement for the study will be stressed. An individualised caloric prescription based on estimates for weight maintenance −600 kcal will be calculated. Motivational interviewing techniques will be used to identify personal motivations for weight change and ways to improve perceived self-efficacy. The programme will utilise personalised diet and physical activity data from baseline measures to set behavioural goals. A range of behavioural strategies will be employed to support lifestyle change including goal setting, identifying specific implementation intentions, self-monitoring and feedback. Emphasis will be placed on self-monitoring body weight, and weighing scales will be provided. Programme acceptability will be explored postintervention with indepth interviews. Compliance and impact will be assessed by baseline and follow-up measures of diet by self-report, activity by accelerometry and anthropometry.

Ethics and dissemination

Ethical approval has been obtained from the Tayside Committee on Medical Research Ethics. Dissemination of results will focus on publications in peer-reviewed journals, presentations at national/international cancer meetings and NHS groups. In addition, the work will be communicated to the public through forums such at The Scottish Cancer Prevention Network (http://www.cancerpreventionscotland.co.uk/). The trial is registered with Current Controlled Trials (International Standard Randomised Controlled Trials No:ISRCTN53033856).
Implementation of a novel communication tool and its effect on patient comprehension of care and satisfaction
Authors: Simmons Stefanie Anne , Sharp Brian , Fowler Jennifer , Singal Bonita
Published: May 2012

Background

Emergency department (ED) communication has been demonstrated as requiring improvement and ED patients have repeatedly demonstrated poor comprehension of the care they receive. Through patient focus groups, the authors developed a novel tool designed to improve communication and patient comprehension.

Study design

This is a prospective, randomised controlled clinical trial to test the efficacy of a novel, patient-centred communication tool. Patients in a small community hospital ED were randomised to receive the instrument, which was utilised by the entire ED care team and served as a checklist or guide to the patients' ED stay. At the end of the ED stay, patients completed a survey of their comprehension of the care and a communication assessment tool-team survey (a validated instrument to assess satisfaction with communication). Three blinded chart reviewers scored patients' comprehension of their ED care as concordant, partially concordant or discordant with charted care. The authors tested whether there was a difference in satisfaction using a two-sample t test and a difference in comprehension using ordinal logistic regression analysis.

Results

146 patients were enrolled in the study with 72 randomised to receive the communication instrument. There was no significant difference between groups in comprehension (OR=0.65, 95% CI 0.34 to 1.23, p=0.18) or communication assessment tool-team scores (difference=0.2, 95% CI: −3.4 to 3.8, p=0.91).

Conclusions

Using their novel communication tool, the authors were not able to show a statistically significant improvement in either comprehension or satisfaction, though a tendency towards improved comprehension was seen.
Analysis of emergency physicians' Twitter accounts
Authors: Lulic Ileana , Kovic Ivor
Published: May 2012

Background

Twitter is one of the fastest growing social media networks for communication between users via short messages. Technology proficient physicians have demonstrated enthusiasm in adopting social media for their work.

Objective

To identify and create the largest directory of emergency physicians on Twitter, analyse their user accounts and reveal details behind their connections.

Methods

Several web search tools were used to identify emergency physicians on Twitter with biographies completely or partially written in English. NodeXL software was used to calculate emergency physicians' Twitter network metrics and create visualisation graphs.

Results

The authors found 672 Twitter accounts of self-identified emergency physicians. Protected accounts were excluded from the study, leaving 632 for further analysis. Most emergency physicians were located in USA (55.4%), had created their accounts in 2009 (43.4%), used their full personal name (77.5%) and provided a custom profile picture (92.2%). Based on at least one published tweet in the last 15 days, there were 345 (54.6%) active users on 31 December 2011. Active users mostly used mobile devices based on the Apple operating system to publish tweets (69.2%). Visualisation of emergency physicians' Twitter network revealed many users with no connections with their colleagues, and a small group of most influential users who were highly interconnected.

Conclusions

Only a small proportion of registered emergency physicians use Twitter. Among them exists a smaller inner network of emergency physicians with strong social bonds that is using Twitter's full potentials for professional development.
PTEN deletion is rare but often homogeneous in gastric cancer
Authors: Mina Sormeh , Bohn Benjamin A , Simon Ronald , Krohn Antje , Reeh Matthias , Arnold Dirk , Bokemeyer Carsten , Sauter Guido , Izbicki Jakob R , Marx Andreas , Stahl Phillip R
Published: May 2012

Background and aim

Gastric carcinoma is the second most frequent cause of cancer-related death worldwide. As PTEN is a potential modifier of tumour response to trastuzumab, a recently approved therapy in metastatic HER2 positive gastric cancer, the existence of PTEN deletions in primary gastric cancer was investigated.

Methods

230 primary gastric cancers were analysed in a tissue microarray format by dual labelling fluorescence in situ hybridisation for PTEN deletion. HER2 analysis was also performed. To study PTEN deletion heterogeneity, all available large tissue sections from primary cancer and corresponding metastases were analysed in seven patients.

Results

Eight of 180 interpretable primary gastric cancer spots showed PTEN deletions (4.4%), including seven hemizygous and one homozygous deletion. PTEN deletion was correlated with nodal (8 of 122 cases (6.6%); p=0.041) and distant metastases (4 of 19 (21.1%); p<0.001). Large section validation showed a homogeneous distribution of PTEN deletion. HER2 positivity was seen in one PTEN deleted case.

Conclusion

Genomic PTEN deletion is a rare event in gastric adenocarcinoma but correlates with metastatic disease. The homogeneous distribution pattern indicates that this alteration occurs early in tumour development.
Twisted gastrulation expression in cholangiocellular and hepatocellular carcinoma
Authors: Johnston Jolene , Al-Bahrani Redha , Abuetabh Yasser , Chiu Brian , Forsman Cynthia L , Nagamori Seishi , Leng Roger , Petryk Anna , Sergi Consolato
Published: May 2012

Aims

To assess the expression of Twisted gastrulation (TWSG1) protein, which regulates the activity of bone morphogenetic proteins (BMPs) in the extracellular space in malignant epithelial tumours of the liver.

Methods

Thirteen hepatocellular carcinoma (HCC) samples and 12 intrahepatic cholangiocellular carcinoma (CCA) samples were compiled into diagnosis-specific tissue microarrays. Sections were immunostained with a monoclonal antibody against TWSG1 and a polyclonal antibody against BMP4. Human cell lines were also used, including one HCC cell line (HepG2), three CCA cell lines (OZ, Huh-28, HuCCT-1) and a Papova-immortalised normal hepatocyte cell line (THLE-3) for western blot analysis (WBA).

Results

Immunostaining and WBA showed a stronger TWSG1 expression in CCA than in HCC. The difference in expression was significant (p<0.05), and the immunohistochemical signal was particularly evident in the malignant epithelial areas close to desmoplastic stroma in CCA and in the areas of glandular differentiation in HCC. No expression was seen in normal hepatocytes. Interestingly, BMP4 was fully expressed in CCA and only partly in HCC. WBA showed a band for BMP4 in both CCA and HCC cell lines.

Conclusions

TWSG1 is expressed in both malignant epithelial carcinomas, although the level of expression is higher in CCA than in HCC and seems to correlate at least partially with BMP4 expression.
Use of matrix assisted laser desorption ionisation–time of flight mass spectrometry in a paediatric clinical laboratory for identification of bacteria commonly isolated from cystic fibrosis patients
Authors: Desai Ankita Patel , Stanley Theresa , Atuan Maria , McKey Jonelle , Lipuma John J , Rogers Beverly , Jerris Robert
Published: May 2012

Background

Matrix-assisted laser desorption ionisation–time of flight mass spectrometry (MALDI-TOF MS) has been described as a rapid, accurate method for bacterial identification.

Aims

To investigate the ability of the technique, using the unamended database supplied with the system, to identify bacteria commonly isolated in cystic fibrosis (CF) patients.

Methods

Organisms commonly isolated from CF patients identified by MALDI-TOF MS were compared to conventional phenotypic and genotypic analyses. For MALDI-TOF MS, the direct colony technique was used routinely with one extraction procedure performed on a mucoidPseudomonas aeruginosa. For 24 unique CF specimens, workload comparison and time to identification were assessed.

Results

Of 464 tested isolates, conventional (phenotypic and genotypic) identification compared to MALDI-TOF MS showed complete genus, species agreement in 92%, with genus agreement in 98%. This included 29 isolates within theBurkholderia cepaciacomplex. All 29 were correctly identified to the genus level and 24 of these were speciated. Time to identification with 47 bacterial isolates from 24 CF patients showed identification of 85% of isolates by MALDI-TOF MS at 48 h of incubation, compared to only 34% with conventional methods.

Conclusions

Using the unamended database supplied with the system, MALDI-TOF MS provides rapid and reliable identification of bacteria isolated from CF specimens. Time to identification studies showed that the use of same day, same method for organism identification will decrease time to result and optimise microbiology workflow.