Recurrent, metastatic prostate cancer continues to be a leading cause of cancer-death in men. The androgen receptor (AR) is a modular, ligand-inducible transcription factor that regulates the expression of genes that can drive the progression of this disease, and as a consequence, this receptor is a key therapeutic target for controlling prostate cancer. The current drugs designed to directly inhibit the AR are called anti-androgens, and all act by competing with androgens for binding to the androgen/ligand binding site. Unfortunately, with the inevitable progression of the cancer to castration resistance, many of these drugs become ineffective. However, there are numerous other regulatory sites on this protein that have not been exploited therapeutically. The regulation of AR activity involves a cascade of complex interactions with numerous chaperones, co-factors and co-regulatory proteins, leading ultimately to direct binding of AR dimers to specific DNA androgen response elements within the promoter and enhancers of androgen-regulated genes. As part of the family of nuclear receptors, the AR is organized into modular structural and functional domains with specialized roles in facilitating their inter-molecular interactions. These regions of the AR present attractive, yet largely unexploited, drug target sites for reducing or eliminating androgen signaling in prostate cancers. The design of small molecule inhibitors targeting these specific AR domains is only now being realized and is the culmination of decades of work, including crystallographic and biochemistry approaches to map the shape and accessibility of the AR surfaces and cavities. Here, we review the structure of the AR protein and describe recent advancements in inhibiting its activity with small molecules specifically designed to target areas distinct from the receptor’s androgen binding site. It is anticipated that these new classes of anti-AR drugs will provide an additional arsenal to treat castration-resistant prostate cancer.
androgen receptor; prostate cancer; castration resistance; anti-androgens; protein structure; structure-based drug design
The androgen receptor (AR) is the best studied drug target for the treatment of prostate cancer. While there are a number of drugs that target the AR, they all work through the same mechanism of action and are prone to the development of drug resistance. There is a large unmet need for novel AR inhibitors which work through alternative mechanism(s). Recent studies have identified a novel site on the AR called Binding Function 3 (BF3) that is involved into AR transcriptional activity. In order to identify inhibitors that target the BF3 site, we have conducted a large-scale in-silico screen followed by experimental evaluation. A number of compounds were identified that effectively inhibited the AR transcriptional activity with no obvious cytotoxicity. The mechanism of action of these compounds was validated by biochemical assays and x-ray crystallography. These findings lay a foundation for the development of alternative or supplementary therapies capable of combating prostate cancer even in its anti-androgen resistant forms.
anti-androgens; androgen receptor; virtual screening; prostate cancer; drug resistance; protein-protein interactions; protein-protein interactions; co-regulation
Prediction and validation of microRNA (miRNA) targets are essential for understanding functions of miRNAs in gene regulation. Crosslinking immunoprecipitation (CLIP) allows direct identification of a huge number of Argonaute-bound target sequences that contain miRNA binding sites. By analysing data from CLIP studies, we identified a comprehensive list of sequence, thermodynamic and target structure features that are essential for target binding by miRNAs in the 3′ untranslated region (3′ UTR), coding sequence (CDS) region and 5′ untranslated region (5′ UTR) of target messenger RNA (mRNA). The total energy of miRNA:target hybridization, a measure of target structural accessibility, is the only essential feature common for both seed and seedless sites in all three target regions. Furthermore, evolutionary conservation is an important discriminating feature for both seed and seedless sites. These features enabled us to develop novel statistical models for the predictions of both seed sites and broad classes of seedless sites. Through both intra-dataset validation and inter-dataset validation, our approach showed major improvements over established algorithms for predicting seed sites and a class of seedless sites. Furthermore, we observed good performance from cross-species validation, suggesting that our prediction framework can be valuable for broad application to other mammalian species and beyond. Transcriptome-wide binding site predictions enabled by our approach will greatly complement the available CLIP data, which only cover small fractions of transcriptomes and known miRNAs due to non-detectable levels of expression. Software and database tools based on the prediction models have been developed and are available through Sfold web server at http://sfold.wadsworth.org.
Heat-treating expressed breastmilk is recommended as an interim feeding strategy for HIV-exposed infants in resource-poor countries, but data on its feasibility are minimal. Flash-heating (FH) is a simple in-home technique for heating breastmilk that inactivates HIV while preserving its nutritional and anti-infective properties. Our primary objective was to determine, among HIV-infected mothers, the feasibility and protocol adherence of FH expressed breastmilk after 6 months of exclusive breastfeeding.
101 HIV-infected breastfeeding mothers
Dar es Salaam, Tanzania
Peer counselors provided in-home counseling and support on infant feeding from 2 to 9 months postpartum. Mothers were encouraged to exclusively breastfeed for 6 months followed by FH expressed breastmilk if her infant was HIV-negative. Clinic-based staff measured infant growth and morbidity monthly and mothers kept daily logs of infant morbidity. FH behavior was tracked until 9 months postpartum using daily logs, in-home observations, and clinic-and home-based surveys. Bacterial cultures of unheated and heated milk samples were performed.
Thirty-seven of 72 eligible mothers (51.4%) chose to Flash-heat. Median (range) frequency of milk expression was 3 (1–6) times daily and duration of method use on-study was 9.7 (0.1–15.6) weeks. Mean (SD) daily milk volume was 322 (201) mL (range 25–1120). No heated and 32 (30.5%) unheated samples contained bacterial pathogens.
FH is a simple technology that many HIV-positive women can successfully use after exclusive breastfeeding to continue to provide the benefits of breastmilk while avoiding maternal-to-child transmission associated with non-exclusive breastfeeding. Based on these feasibility data, a clinical trial of the effects of FH breastmilk on infant health outcomes is warranted.
HIV; infant feeding; breastmilk; pasteurization; feasibility; heat-treatment; Flash-heat; maternal-to-child transmission
Bin3 is a conserved RNA methyltransferase found in eukaryotes ranging from fission yeast to humans. It was originally discovered as a Bicoid-interacting protein in Drosophila, where it is required for anterior-posterior and dorso-ventral axis determination in the early embryo. The mammalian ortholog of Bin3 (BCDIN3), also known as methyl phosphate capping enzyme (MePCE), plays a key role in repressing transcription. In transcription, MePCE binds the non-coding 7SK RNA, which forms a scaffold for an RNA-protein complex that inhibits P-TEFb, an RNA polymerase II elongation factor. MePCE uses S-adenosyl methionine to transfer a methyl group onto the γ-phosphate of the 5′ guanosine of 7SK RNA generating an unusual cap structure that protects 7SK RNA from degradation. Bin3/MePCE also has a role in translation regulation. Initial studies in Drosophila indicate that Bin3 targets 7SK RNA and stabilizes a distinct RNA-protein complex that assembles on the 3′ UTR of caudal mRNAs to prevent translation initiation. Much remains to be learned about Bin3/MeCPE function, including how it recognizes 7SK RNA, what other RNA substrates it might target, and how widespread a role it plays in gene regulation and embryonic development.
Existing intensive care unit (ICU) mortality measurement systems address in-hospital mortality only. However, early post-discharge mortality contributes significantly to overall 30-day mortality. Factors associated with early post-discharge mortality are unknown.
We performed a retrospective study of 8,484 ICU patients. Our primary outcome was early post-discharge mortality: death after hospital discharge and ≤ 30 days from ICU admission. Cox regression models assessed the association between patient, hospital, and utilization factors and the primary outcome.
In multivariate analyses, the hazard for early post-discharge mortality increased with rising severity of illness and decreased with full code status (HR = 0.33, 95% CI 0.21 to 0.49). Compared to discharges home, early post-discharge mortality was highest for acute care transfers (HR 3.18, 95% CI 2.45 to 4.12). Finally, patients with very short ICU length of stay (< 1 day) had greater early post-discharge mortality (HR 1.86, 95% CI 1.32 to 2.61) than those with longest stays (≥ 7 days).
Early post-discharge mortality is associated with patient preferences (full-code status) and decisions regarding timing and location of discharge. These findings have important implications for anyone attempting to measure or improve ICU performance and who rely upon in-hospital mortality measures to do so.
Intensive Care Unit; Hospital Mortality; Patient Discharge; Outcome Assessment (Health Care); Health Services Research
Increased daytime sleepiness is an important symptom of obstructive sleep apnea (OSA). OSA is frequently underdiagnosed, and the Epworth Sleepiness Scale (ESS) can be a useful tool in alerting physicians to a potential problem involving OSA.
To measure the prevalence and determinants of daytime sleepiness measured using the ESS in a rural community population.
A community survey was conducted to examine the risk factors associated with ESS in a rural population in 154 households comprising 283 adults. Questionnaire information was obtained regarding physical factors, social factors, general medical history, family medical history, ESS score, and self-reported height and weight. Multivariable binary logistic regression analysis based on the generalized estimating equations approach to account for clustering within households was used to predict the relationship between a binary ESS score outcome (normal or abnormal) and a set of explanatory variables.
The population included 140 men (49.5%) and 143 women (50.5%) with an age range of 18 to 97 years (mean [± SD] 52.0±14.9 years). The data showed that 79.2% of the study participants had an ESS score in the normal range (0 to 10) and 20.8% had an ESS score >10, which is considered to be abnormal or high sleepiness. Multivariable regression analysis revealed that obesity was significantly associated with an abnormal or high sleepiness score on the ESS (OR 3.40 [95% CI 1.31 to 8.80).
High levels of sleepiness in this population were common. Obesity was an important risk factor for high ESS score.
Epworth Sleepiness Scale; Obesity; Rural; Snoring
Colon cancer (CC) patients commonly suffer declines in muscle mass and aerobic function. We hypothesised that CC would be associated with reduced muscle mass and mitochondrial enzyme activity and that curative resection would exacerbate these changes.
We followed age-matched healthy controls and CC patients without distant metastasis on radiological imaging before and 6 weeks after hemi-colectomy surgery. Body composition was analysed using dual energy X-ray absorptiometry. Mitochondrial enzyme activity and protein concentrations were analysed in vastus lateralis muscle biopsies.
In pre-surgery, there were no differences in lean mass between CC patients and age-matched controls (46.1 + 32.5 vs. 46.1 + 37.3 kg). Post-resection lean mass was reduced in CC patients (43.8 + 30.3 kg, P < 0.01). When comparing markers of mitochondrial function, the following were observed: pyruvate dehydrogenase (PDH) activity was lower in CC patients pre-surgery (P < 0.001) but normalized post-resection and cytochrome c oxidase and pyruvate dehydrogenase E2 subunit protein expression were lower in CC patients pre-surgery and not restored to control values post-resection (P < 0.001). Nuclear factor kappa-B, an inflammatory marker, was higher in CC patients pre-surgery compared to controls (P < 0.01), returning to control levels post-resection.
Muscle mass was affected by surgery rather than cancer per se. PDH activity was however lower in cancer patients, suggesting that muscle mass and mitochondrial enzyme activity are not inextricably linked. This reduction in mitochondrial enzyme activity may well contribute to the significant risks of major surgery to which CC patients are exposed.
Cancer; Muscle; Mitochondria; Pyruvate dehydrogenase
The presence of the appendix in an inguinal hernia sac is rare, with an estimated incidence of 0.51–1% of all inguinal hernias. An inguinal appendix is most commonly referred to as Amyand's hernia.
PRESENTATION OF CASE
A 59-year-old HIV positive male presented to our center with a left painful inguinal mass. The preoperative diagnosis was a left inguinal hernia. Intraoperatively, the sac was found to contain a non inflamed appendix; the appendix was reduced back to the peritoneal cavity and the patient underwent a tension free prosthetic left inguinal hernia repair.
Most cases of inguinal appendices are right-sided and are diagnosed intraoperatively; left-sided cases as we encountered are rare and most likely the result of cecal mobility. Preoperative diagnosis of the entity is difficult and most cases are diagnosed intraoperatively. A CT scan is not necessary unless other pressing differentials need to be ruled out. Most authors agree that if the appendix is not inflamed, appendectomy, concurrently with herniorrhaphy, should not be performed to avoid perioperative septic complications.
Surgical management of inguinal appendices carries a risk of septic complications. This is especially pertinent to our case, considering the immunocompromised status of our patient. The decisions in the operating room were geared toward limiting septic potential.
Amyand hernia; Inguinal appendix
Although rural Canadians are reported to have higher rates of diabetes than others, little is known about the relative influence of known versus agriculture-related risk factors. The purpose of this research was to carry out a comprehensive study of prevalence, risk factors and co-morbidities of diabetes among adults in rural Saskatchewan and to determine possible differences between those living on and off farms.
In 2010, we conducted a baseline mail-out survey (Saskatchewan Rural Health Study) of 11,982 households located in the province′s four agricultural quadrants. In addition to self-reported physician-diagnosed diabetes, the questionnaire collected information from farm and small town cohorts on possible diabetes determinants including lifestyle, family history, early life factors and environmental/agricultural-related exposures. Clustering effect within households was adjusted using Generalized Estimating Equations approach.
Responses were obtained from 4624 (42%) households comprising 8208 males and females aged 18 years or older and 7847 self-described Caucasian participants (7708 with complete information). The overall age-standardized diabetes prevalence for the latter was 6.35% but people whose primary residence was on farms had significantly lower diabetes prevalence than those living in non-farm locations (5.11% versus 7.33% respectively; p<0.0001). Diabetes risk increased with age and affected almost 17% of those older than 65 (OR 2.57; CI′ 1.63, 4.04 compared to those aged 18–45). Other known independent risk factors included family history of diabetes (OR 2.50 [CI′s 1.94, 3.23] if father; OR 3.11 [CI′s 2.44, 3.98] if mother), obesity (OR 2.66; CI′s 1.86, 3.78), as well as lower socioeconomic status, minimal/no alcohol intake and smoking. The most original finding was that exposure to insecticides conferred an increased risk for diabetes among males (OR 1.83; CI′s 1.15, 2.91). Finally, the co-morbidities with the strongest independent association with diabetes were heart disease and hypertension.
While known diabetes risk factors are important determinants of diabetes in the agricultural zones of Saskatchewan, on-farm residence is protective and appears related to increased outdoor activities. In contrast, we have now shown for the first time that exposure to insecticides is an independent risk factor for diabetes among men in rural Canada.
Diabetes; Rural; Agriculture; Insecticides; Farm; Exposures
Eye colour is one of the most important characteristics in determining facial appearance. In this paper I shall discuss the anatomy and genetics of normal eye colour, together with a wide and diverse range of conditions that may produce an alteration in normal iris pigmentation or form.
eye colour; heterochromia; neoplasm; iris; melanoma; melanocyte
Smoking can increase the risk of macular degeneration and this is more than additive if a person also has a genetic risk. The purpose of this study was to examine whether knowledge of genetic risk for age-related macular degeneration (AMD) could influence motivation to quit smoking.
A questionnaire-based study of hypothetical case scenarios given to 49 smokers without AMD. Participants were randomly allocated to a generic risk, high genetic risk, or low genetic risk of developing AMD scenario.
Forty-seven percent knew of the link between smoking and eye disease. In all, 76%, 67%, and 46% for the high risk, generic, and low risk groups, respectively, would rethink quitting (Pfor trend=0.082). In all, 67%, 40%, and 38.5%, respectively, would be likely, very likely, or would definitely quit in the following month (Pfor trend=0.023). Few participants (<16% of any group) were very likely to or would definitely attend a quit smoking session with no difference across groups. In all, 75.5% of participants would consider taking a genetic test for AMD.
In this pilot study, a trend was seen for the group given high genetic risk information to be more likely to quit than the generic or low genetic risk groups. Participants were willing to take a genetic test but further work is needed to address the cost benefits of routine genetic testing for risk of AMD. More generic risk information should be given to the public, and health warnings on cigarette packets that ‘smoking causes blindness' is a good way to achieve this.
macular degeneration; smoking; risk factors; smoking cessation; risk
Increased dietary long-chain n-3 polyunsaturated fatty acid (LCn-3PUFA) intake stimulates muscle protein anabolism in individuals who experience muscle loss due to aging or cancer cachexia. However, it is not known whether LCn-3PUFA elicit similar anabolic effects in healthy individuals. To answer this question we evaluated the effect of 8 weeks of LCn-3PUFA supplementation (4 g·d−1 of Lovaza®) in nine 25–45 y old healthy subjects on the rate of muscle protein synthesis (by using stable isotope labelled tracer techniques) and the activation (phosphorylation) of elements of the mTOR-p70s6k pathway during basal, postabsorptive conditions and during a hyperinsulinemic-hyperaminoacidemic clamp. We also measured the concentrations of protein, RNA, and DNA in muscle to obtain indices of the protein synthetic capacity, translational efficiency and cell size. Neither the basal muscle protein fractional synthesis rate nor basal signalling element phosphorylation changed in response to LCn-3PUFA supplementation but the anabolic response to insulin and amino acid infusion was greater after LCn-3PUFA (i.e., the muscle protein fractional synthesis rate during insulin and amino acid infusion increased from 0.062 ± 0.004 to 0.083 ± 0.007 %·h−1 and the phospho mTORSer2448 and p70s6kThr389 concentrations increased by ~50%; all P < 0.05). In addition, the muscle protein concentration and the protein-to-DNA ratio (i.e., muscle cell size) were both greater (P < 0.05) after LCn-3PUFA supplementation. We conclude that LCn-3PUFA have anabolic properties in healthy young and middle aged adults.
n-3 PUFA; fish oil; muscle protein synthesis
Afferent innervation patterns in the vestibular periphery are complex and vestibular afferents show a large variation in their regularity of firing. Calyx fibers terminate on type I vestibular hair cells and have firing characteristics distinct from bouton fibers that innervate type II hair cells. Whole cell patch clamp was used to investigate ionic currents that could influence firing patterns in calyx terminals. Underlying K(Ca) conductances have been described in vestibular ganglion cells, but their presence in afferent terminals has not been investigated previously. Apamin, a selective blocker of SK-type calcium-activated K+ channels, was tested on calyx afferent terminals isolated from gerbil semicircular canals during postnatal days 1 to 50. Lowering extracellular calcium or application of apamin (20–500 nM) reduced slowly activating outward currents in voltage clamp. Apamin also reduced the action potential after-hyperpolarization (AHP) in whole cell current clamp, but only after the first two postnatal weeks. K+ channel expression increased during the first postnatal month and SK channels were found to contribute to the AHP, which may in turn influence discharge regularity in calyx vestibular afferents.
Afferent; After-hyperpolarization; Crista; Hair cell; Inner ear; Development
Increased levels of endotoxin found in rural and agricultural areas are an environmental exposure believed to cause a paradoxical proinflammatory effect on respiratory health that can exacerbate asthma. Previous studies involving adults have demonstrated an association between high endotoxin levels and lower lung function. Apart from occupational settings, however, few studies have investigated the relationship between lung function and endotoxin exposure, such as environmental tobacco smoke, especially in children. This study examined the modifying effects of sex, pre-existing asthma and other environmental exposures, including tobacco smoke, in children living in rural communities in Saskatchewan.
Knowledge of the effects of domestic endotoxin on children’s lung function is limited. The association between domestic endotoxin and asthma or wheeze and lung function among school-age children (six to 18 years of age) was examined. The interaction between endotoxin and other personal and environmental characteristics and lung function was also assessed.
A case-control study was conducted in and around the rural community of Humboldt, Saskatchewan, between 2005 and 2007. Parents of cases reported either doctor-diagnosed asthma or wheeze in the previous year. Controls were randomly selected from those not reporting these conditions. Data were collected by questionnaire to ascertain symptoms and conditions, while spirometry was used to measure lung function including forced vital capacity and forced expiratory volume in 1 s. Dust collected from the child’s play area floor and the child’s mattress was used to quantify endotoxin, and saliva was collected to quantify cotinine levels and assess tobacco smoke exposure.
There were 102 cases and 207 controls included in the present study. Lower forced expiratory volume in 1 s was associated with higher mattress endotoxin load among female cases (beta=−0.25, SE=0.07 [P<0.01]). There was a trend toward lower forced vital capacity, which was associated with higher play area endotoxin load among cases with high tobacco smoke exposure (beta=−0.17, SE=0.09 [P<0.10]).
Findings indicated that high endotoxin levels present in common household areas of rural children with asthma or wheeze may also affect their lung function. These associations may be potentiated by tobacco smoke exposure and female sex.
Asthma; Endotoxin; Lung function; Rural; Tobacco smoke; Wheeze
The amniotic membrane (AM) and amniotic fluid (AF) have a long history of use in surgical and prenatal diagnostic applications, respectively. In addition, the discovery of cell populations in AM and AF which are widely accessible, nontumorigenic and capable of differentiating into a variety of cell types has stimulated a flurry of research aimed at characterizing the cells and evaluating their potential utility in regenerative medicine. While a major focus of research has been the use of amniotic membrane and fluid in tissue engineering and cell replacement, AM- and AF-derived cells may also have capabilities in protecting and stimulating the repair of injured tissues via paracrine actions, and acting as vectors for biodelivery of exogenous factors to treat injury and diseases. Much progress has been made since the discovery of AM and AF cells with stem cell characteristics nearly a decade ago, but there remain a number of problematic issues stemming from the inherent heterogeneity of these cells as well as inconsistencies in isolation and culturing methods which must be addressed to advance the field towards the development of cell-based therapies. Here, we provide an overview of the recent progress and future perspectives in the use of AM- and AF-derived cells for therapeutic applications.
Objectives and design
We identified a novel TRIM59 gene, as an early signal transducer in two (SV40Tag and Ras) oncogene pathways in murine prostate cancer (CaP) models. We explore its clinical applications as a multitumour marker detecting early tumorigenesis by immunohistochemistry (IHC).
Setting and participants
88 CaP patients were from a tissue microarray (TMA) of radical prostatectomy specimen, 42 patients from a 35 multiple tumour TMA, 75 patients with renal cell carcinoma (RCC) and 92 patients from eight different tumour groups (breast, lung, parotid, gastrointestinal, female genital tract, bladder, kidney and prostate cancer).
TRIM59 upregulation specifically in tumour area was determined by IHC in 291 cases of 37 tumour types. To demonstrate that TRIM59 upregulation is ‘tumour-specific’, we characterised a significant correlation of TRIM59 IHC signals with tumorigenesis and progression, while in control and normal area, TRIM59 IHC signal was all negative or significantly low. TRIM59 protein upregulation in prostate and kidney cancers was detectable in both intensity and extent in early tumorigenesis of prostate intraepithelial neoplasia (p<0.05) and grade 1 of RCC (p<0.05), and stopped until high grades cancer. The results of the correlation in these two large cohorts of tumour types confirmed and repeated murine CaP model studies. Enhanced TRIM59 expression was identified in most of the 37 different tumours, while the highest intensities were in lung, breast, liver, skin, tongue and mouth (squamous cell cancer) and endometrial cancers. Multiple tumour upregulation was further confirmed by comparing relative scores of TRIM59 IHC signals in eight tumours with a larger patient population; and by a mouse whole-mount embryo (14.5 days post conception) test on the origin of TRIM59 upregulation in epithelial cells.
TRIM59 may be used a novel multiple tumour marker for immunohistochemical detecting early tumorigenesis and could direct a novel strategy for molecular-targeted diagnosis and therapy of cancer.
Criteria for sonographic diagnosis of monosodium urate (MSU) crystal deposition have been developed, but the inter-reader reproducibility of this modality is not well-established. We therefore assessed agreement using a systematic approach.
50 male subjects ages 55-85 were recruited during primary care visits to an urban VA hospital, and were assessed by musculoskeletal ultrasound (MSK-US) of the knees and 1st metatarsophalangeal (MTP) joints to evaluate for the “double contour” sign and tophi as evidence of MSU crystal deposition. Images were read by two blinded rheumatologists trained in MSK-US, and degree of concordance was determined for individual patients, total joints, femoral articular cartilage (FAC) and 1st MTP joints. Patients were further categorized into three diagnostic groups: gout, asymptomatic hyperuricemia (AH) (no gout, serum uric acid (UA) ≥ 6.9 mg/dL) and controls (no gout, UA ≤ 6.8 mg/dL), and reader concordance within these three groups was assessed.
We observed almost perfect agreement between readers for: 1) individual patients (yes/no) (n=50, 100% agreement, kappa=1.000); 2) total joints (n=200, 99% agreement, kappa=0.942); 3) FAC (n=100, 99% agreement, kappa=0.942); and 4) 1st MTPs (n=100, 99% agreement, kappa=0.942). Furthermore, findings by side (right/left) and diagnostic group (gout, AH, control) showed substantial to almost perfect concordance for all measures. MSU deposition was seen most commonly in gout patients, and deposition was also seen in some patients with asymptomatic hyperuricemia, but in only one control.
MSK-US is reliable for detecting MSU deposition in FAC and 1st MTPs in gout and AH.
The M.I.C. Evaluator strip (Thermo Fisher Scientific, Basingstoke, United Kingdom) uses a methodology similar to that of Etest. In this first assessment of the M.I.C. Evaluator device, 409 strains of aerobic Gram-positive bacteria (staphylococci, streptococci, and enterococci) and 325 strains of Enterobacteriaceae, Pseudomonas species, and Acinetobacter species were tested by M.I.C. Evaluator strip, Etest, and broth microdilution as a reference standard. The Gram-positive bacteria included staphylococci (methicillin-resistant Staphylococcus aureus, methicillin-susceptible S. aureus, and coagulase-negative staphylococci), Streptococcus pneumoniae, beta-hemolytic streptococci and viridians group strains, vancomycin-resistant enterococci, and other enterococci. The Gram-negative bacteria included 250 strains of 60 Enterobacteriaceae species plus 50 Pseudomonas and 25 Acinetobacter species. A total of 14 antimicrobial agents (depending on the species) were included. The same methodology and reading format were used for M.I.C. Evaluator strips and Etest. Broth microdilution methodology was performed according to CLSI document M07-A8. For the clinical strains, >95% of results were plus or minus one doubling dilution for all species. There were fewer than 5% minor errors, fewer than 3% major errors, and fewer than 1% very major errors. M.I.C. Evaluator strips and Etest often reported higher MICs than the reference broth microdilution method. The M.I.C. Evaluator strips provided results comparable to those of the predicate Etest device and are of value for the accurate testing of MICs for these important pathogens.
The new M.I.C. Evaluator strip uses test methodology and the recording of results that are similar to those of Etest. For this first assessment, 102 clinical strains of anaerobic bacteria from 12 genera and 155 strains from 7 genera and 8 species of fastidious bacteria were tested by M.I.C. Evaluator, Etest, and agar dilution or broth microdilution as a reference standard. Ampicillin, amoxicillin, amoxicillin-clavulanate, cefotaxime, ciprofloxacin, erythromycin, imipenem, levofloxacin, metronidazole, penicillin, and tetracycline were tested depending on the species. Agar dilution for anaerobes was performed according to CLSI document M11-A7. For the fastidious bacteria, CLSI document M45-A2 was followed. For the anaerobes, essential and categorical agreement between M.I.C. Evaluator and Etest was >90%. Compared to agar dilution, essential agreement was low for both strip tests, and many very major errors were observed for metronidazole (13 to 14%) and penicillin (8 to 9%) with isolates from the Bacteroides fragilis group and Clostridium species. For fastidious species, essential agreements for M.I.C. Evaluator and Etest plus or minus one doubling dilution were >95%. Compared to broth microdilution, essential agreements were low (40 to 90%) plus or minus one dilution and were >90% plus or minus two dilutions, with high overall category agreement (CA). Major and minor errors were within established parameters for all strains tested. The M.I.C. Evaluator strips were equivalent to Etest for anaerobes and fastidious species. These observations require further investigation to determine which methods provide the most accurate MIC for clinical utility. The further evaluation of additional M.I.C. Evaluator agents will be performed as they become available.
The association between endotoxin exposure and asthma is complex and has been associated with rural living. We examined the relationship between domestic endotoxin and asthma or wheeze among rural school-aged children (6–18 years) and assessed the interaction between endotoxin and other characteristics with these outcomes.
Between 2005 and 2007 we conducted a case–control study of children 6–18 years in the rural region of Humboldt, Canada. Cases (n = 102) reported doctor-diagnosed asthma or wheeze in the past year. Controls (n = 208) were randomly selected from children without asthma or wheeze. Data were collected to ascertain symptoms, asthma history and indoor environmental exposures (questionnaire), endotoxin (dust collection from the play area floor and child’s mattress), and tobacco smoke exposure (saliva collection). Statistical testing was completed using multiple logistic regression to account for potential confounders and to assess interaction between risk factors. A stratified analysis was also completed to examine the effect of personal history of allergy.
Among children aged 6–12 years, mattress endotoxin concentration (EU/mg) and load (EU/m2) were inversely associated with being a case [odds ratio (OR) = 0.44, 95% confidence interval (CI) = 0.20-0.98; and OR = 0.38, 95% CI = 0.20-0.75, respectively]. These associations were not observed in older children or with play area endotoxin.
Our results suggest that endotoxin exposure might be protective for asthma or wheeze. The protective effect is found in younger school-aged, non-allergic children. These results may help explain the inconsistencies in previous studies and suggest that the protective effects of endotoxin in the prevention of atopy and asthma or wheeze are most effective earlier in life.
Asthma; Children; Endotoxin; Wheeze; Pediatrics; Allergy
Blunt traumatic vertebral injury (TVAI) is frequently associated with head and neck injury and is being detected with increasing frequency due to improved imaging of the trauma patient. In a few cases, it can lead to potentially fatal posterior circulation ischaemia There is debate in the literature regarding whether TVAI should be actively screened for and, if so, how. Management of TVAI may be conservative, medical (antiplatelet agents or anticoagulation), endovascular or open surgery. We review the literature concerning the mechanisms and presentation of TVAI following blunt injury and the current screening recommendations. Management strategies proposed are based on the radiological grade and clinical severity of TVAI, where high-grade symptomatic injuries and high-grade injuries in patients where anticoagulation is contraindicated are treated endovascularly and asymptomatic or low-grade injuries are managed with anticoagulation where it is not contraindicated. Follow-up is via CT angiography to assess for resolution of the injury.
Traumatic; Vertebral; Artery; Management
Whole-body magnetic resonance imaging allows acquisition of diagnostic images in the shortest scan time, leading to better patient compliance and artifact-free images. Methods of clinical examination of the anterior chest wall joints vary between physician groups and consideration of the rules of rib motion is suggested. The type of joint and its synovial lining may also aid imaging/clinical correlation. This well-written study by experts in the field with a standardized design and methodology allows good scientific analysis and suggests the advantages of whole-body magnetic resonance imaging in anterior chest wall imaging. Selection of clinical examination criteria and specific joints may have had an influence on the study results and the lack of association reported.