The evolution of the traplining pollinator role in hummingbirds: specialization is not an evolutionary dead end.

Trapliners are pollinators that visit widely dispersed flowers along circuitous foraging routes. The evolution of traplining in hummingbirds is thought to entail morphological specialization through the reciprocal coevolution of longer bills with the long-tubed flowers of widely dispersed plant species. Specialization, such as that exhibited by traplining hummingbirds, is often viewed as both irreversible and an evolutionary dead end. We tested these predictions in a macroevolutionary framework. Specifically, we assessed the relationship between beak morphology and foraging and tested whether transitions to traplining are irreversible and lead to lower rates of diversification as predicted by the hypothesis that specialization is an evolutionary dead end. We find that there have been multiple independent transitions to traplining across the hummingbird phylogeny, but reversals have been rare or incomplete at best. Multiple independent lineages of trapliners have become morphologically specialized, convergently evolving relatively large bills for their body size. Traplining is not an evolutionary dead end however, since trapliners continue to give rise to new traplining species at a rate comparable to non-trapliners.

Circulating tumor DNA in neoadjuvant-treated breast cancer reflects response and survival.

BACKGROUND: Pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) is strongly associated with favorable outcome. We examined the utility of serial circulating tumor DNA (ctDNA) testing for predicting pCR and risk of metastatic recurrence. PATIENTS AND METHODS: Cell-free DNA (cfDNA) was isolated from 291 plasma samples of 84 high-risk early breast cancer patients treated in the neoadjuvant I-SPY 2 TRIAL with standard NAC alone or combined with MK-2206 (AKT inhibitor) treatment. Blood was collected at pretreatment (T0), 3 weeks after initiation of paclitaxel (T1), between paclitaxel and anthracycline regimens (T2), or prior to surgery (T3). A personalized ctDNA test was designed to detect up to 16 patient-specific mutations (from whole-exome sequencing of pretreatment tumor) in cfDNA by ultra-deep sequencing. The median follow-up time for survival analysis was 4.8 years. RESULTS: At T0, 61 of 84 (73%) patients were ctDNA positive, which decreased over time (T1: 35%; T2: 14%; and T3: 9%). Patients who remained ctDNA positive at T1 were significantly more likely to have residual disease after NAC (83% non-pCR) compared with those who cleared ctDNA (52% non-pCR; odds ratio 4.33, P = 0.012). After NAC, all patients who achieved pCR were ctDNA negative (n = 17, 100%). For those who did not achieve pCR (n = 43), ctDNA-positive patients (14%) had a significantly increased risk of metastatic recurrence [hazard ratio (HR) 10.4; 95% confidence interval (CI) 2.3-46.6]; interestingly, patients who did not achieve pCR but were ctDNA negative (86%) had excellent outcome, similar to those who achieved pCR (HR 1.4; 95% CI 0.15-13.5). CONCLUSIONS: Lack of ctDNA clearance was a significant predictor of poor response and metastatic recurrence, while clearance was associated with improved survival even in patients who did not achieve pCR. Personalized monitoring of ctDNA during NAC of high-risk early breast cancer may aid in real-time assessment of treatment response and help fine-tune pCR as a surrogate endpoint of survival.

A Comparison of Iron Oxide Particles and Silica Particles for Tracking Organ Recellularization.

Reseeding of decellularized organ scaffolds with a patient's own cells has promise for eliminating graft versus host disease. This study investigated whether ultrasound imaging or magnetic resonance imaging (MRI) can track the reseeding of murine liver scaffolds with silica-labeled or iron-labeled liver hepatocytes. Mesoporous silica particles were created using the Stöber method, loaded with Alexa Flour 647 fluorophore, and conjugated with protamine sulfate, glutamine, and glycine. Fluorescent iron oxide particles were obtained from a commercial source. Liver cells from donor mice were loaded with the silica particles or iron oxide particles. Donor livers were decellularized and reperfused with silica-labeled or iron-labeled cells. The reseeded livers were longitudinally analyzed with ultrasound imaging and MRI. Liver biopsies were imaged with confocal microscopy and scanning electron microscopy. Ultrasound imaging had a detection limit of 0.28 mg/mL, while MRI had a lower detection limit of 0.08 mg/mL based on particle weight. The silica-loaded cells proliferated at a slower rate compared to iron-loaded cells. Ultrasound imaging, MRI, and confocal microscopy underestimated cell numbers relative to scanning electron microscopy. Ultrasound imaging had the greatest underestimation due to coarse resolution compared to the other imaging modalities. Despite this underestimation, both ultrasound imaging and MRI successfully tracked the longitudinal recellularization of liver scaffolds.

Comparing the epidemiology of hospital-acquired methicillin-resistant Staphylococcus aureus clone groups in Alberta, Canada.

Patients with methicillin-resistant Staphylococcus aureus (MRSA) clones, which were traditionally seen in the community setting (USA400/CMRSA7 and USA300/CMRSA10), are often identified as hospital-acquired (HA) infections using Infection Prevention and Control (IPC) surveillance definitions. This study examined the demographics and healthcare risk factors of patients with HA-MRSA to help understand if community MRSA clones are from a source internal or external to the hospital setting. Despite USA300/CMRSA10 being the predominant clone in Alberta, hospital clones (USA100/CMRSA2) still dominated in the acute care setting. In the Alberta hospitalized population, patients with USA400/CMRSA7 and USA300/CMRSA10 clones were significantly younger, had fewer comorbidities, and a greater proportion had none or ambulatory care-only healthcare exposure. These findings suggest that there are two distinct populations of HA-MRSA patients, and the patients with USA400/CMRSA7 and USA300/CMRSA10 clones identified in hospital more greatly resemble patients affected by those clones in the community. It is possible that epidemiological assessment overidentifies HA acquisition of MRSA in patients unscreened for MRSA on admission to acute care.

The role of drinking water in the transmission of antimicrobial-resistant E. coli.

To determine whether drinking water contaminated with antimicrobial-resistant E. coli is associated with the carriage of resistant E. coli, selected households sending water samples to Ontario and Alberta laboratories in 2005-2006 were asked to participate in a cross-sectional study. Household members aged ≥12 years were asked to complete a questionnaire and to submit a rectal swab. In 878 individuals, 41% carried a resistant strain of E. coli and 28% carried a multidrug-resistant strain. The risk of carriage of resistant E. coli was 1·26 times higher for users of water contaminated with resistant E. coli. Other risk factors included international travel [prevalence ratio (PR) 1·33], having a child in nappies (PR 1·33), being male (PR 1·33), and frequent handling of raw red meats (PR 1·10). Protecting private water sources (e.g. by improving systems to test and treat them) may help slow the emergence of antimicrobial resistance in E. coli.

Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in food samples associated with foodborne illness in Alberta, Canada from 2007 to 2010.

Consumption of foods containing Staphylococcus aureus can cause severe gastro-intestinal illness. Given the fact that over the past decade, Canada has seen increasing rates of methicillin-resistant S. aureus (MRSA) carriage and infection, the objective of this study was to investigate the impact of methicillin-susceptible S. aureus (MSSA) and MRSA on foodborne illness in Alberta, Canada. Between January 2007 and December 2010, there were 693 food samples associated with foodborne investigations submitted to the Alberta Provincial Laboratory for Public Health (ProvLab). These foods were screened for: Bacillus cereus, Clostridium perfringens, S. aureus, Aeromonas spp., Campylobacter spp., Escherichia coli O157:H7, Salmonella, Shigella spp., and Yersinia spp. S. aureus was identified in 10.5% (73/693) of samples, and of these, 59% (43/73) were co-contaminated with at least one other organism on the screening panel. The S. aureus positive samples included 29 meat, 20 prepared foods containing meat, 11 prepared foods not containing meat, 10 dairy, and three produce. Methicillin-resistance was not detected in any isolates tested. These findings indicate that the presence of S. aureus in food associated with foodborne investigations is a cause for concern, and although MRSA was not found, the potential for outbreaks exists, and ongoing surveillance should be sustained.

Allometric conservatism in the evolution of bird beaks.

Evolution can involve periods of rapid divergent adaptation and expansion in the range of diversity, but evolution can also be relatively conservative over certain timescales due to functional, genetic-developmental, and ecological constraints. One way in which evolution may be conservative is in terms of allometry, the scaling relationship between the traits of organisms and body size. Here, we investigate patterns of allometric conservatism in the evolution of bird beaks with beak size and body size data for a representative sample of over 5000 extant bird species within a phylogenetic framework. We identify clades in which the allometric relationship between beak size and body size has remained relatively conserved across species over millions to tens of millions of years. We find that allometric conservatism is nonetheless punctuated by occasional shifts in the slopes and intercepts of allometric relationships. A steady accumulation of such shifts through time has given rise to the tremendous diversity of beak size relative to body size across birds today. Our findings are consistent with the Simpsonian vision of macroevolution, with evolutionary conservatism being the rule but with occasional shifts to new adaptive zones.

Changing epidemiology of methicillin-resistant Staphylococcus aureus in Alberta, Canada: population-based surveillance, 2005-2008.

SUMMARYIncreasing prevalence of methicillin-resistant Staphylococcus aureus (MRSA) has been reported in Canada. We report the results of a prospective surveillance of MRSA infections in Alberta over a consecutive 3-year period. A total of 8910 unique clinical MRSA isolates was analysed from July 2005 to June 2008. The incidence of MRSA infection increased over the study period and was highest in males, age group ⩾85 years, and the Calgary Area. CMRSA10 (USA300) and CMRSA2 (USA100/800) were the most common PFGE strain types, representing 53·0% and 27·9% of all isolates, respectively. Significant differences were noted between MRSA strains in the source of infection and antimicrobial susceptibility. The incidence of MRSA infection in Alberta has nearly doubled in the last 3 years; this is attributed to the emergence of CMRSA10 as the predominant strain.

Tissue-specific consequences of the anti-adenoviral immune response: implications for cardiac transplants.

The immune response to adenoviral vectors can induce inflammation and loss of transgene expression in transfected tissues. This would limit the use of adenovirus-mediated gene transfer in disease states in which long-term gene expression is required. While studying the effect of the anti-adenoviral immune response in transplantation, we found that transgene expression persisted in cardiac isografts transfected with an adenovirus encoding beta-galactosidase. Transfected grafts remained free of inflammation, despite the presence of an immune response to the vector. Thus, adenovirus-mediated gene transfer may have therapeutic value in cardiac transplantation and heart diseases. Furthermore, immunological limitations of adenoviral vectors for gene therapy are not universal for all tissue types.

Identification and characterization of new murine T cell receptor beta chain variable region (V beta) genes.

By screening previously isolated genomic clones spanning the mouse TCR V beta locus with V beta-specific oligonucleotides, we have isolated one new functional V beta gene and six V beta pseudogenes. Because this method of identifying new genes does not depend on expression levels, we conclude that most, if not all, V beta genes in the mouse have been identified. The newly identified pseudogenes increase the frequency of mouse TCR V beta pseudogenes to 28%, a frequency similar to that estimated for mouse Ig VH pseudogenes (24). Three of the newly discovered pseudogenes are clustered in a region around another pseudogene (V beta 17b). The extensive DNA diversity, as reflected in both the nucleotide sequence and the RFLP, indicates that this genomic region is a possible hotspot of recombination. The new functional gene, V beta 19a, is expressed at very low levels, which explains why it has not been isolated earlier. V beta 19 shows expression patterns that correlate with the previously described Va beta and Vb beta haplotypes.

Risk factors for repeat hernia repair in women of childbearing age.

PURPOSE: Herniorrhaphy is a source of substantial cost and morbidity. Although women are a substantial proportion of patients seeking repair, gender-specific data, including the influence of childbirth on hernia recurrence, are lacking. Our objective was to estimate the rate and identify risk factors for repeat herniorrhaphy in reproductive-aged women. METHODS: Retrospective cohort study of women who underwent herniorrhaphy during June 2000-December 2014 in the United States. Women aged 18-50 who underwent umbilical, incisional/ventral, or inguinal/femoral herniorrhaphy in the Truven Health Analytics MarketScan® Commercial Claims and Encounters database were included. Women without a hernia diagnosis or multiple/concurrent index herniorrhaphy types were excluded. Primary outcome of interest was second herniorrhaphy. RESULTS: Of 123,674 women, 13% had a second herniorrhaphy within 10 years; increasing age, comorbidities, childbirth, smoking, obesity, and inpatient procedure were independently associated with increased risk. Cesarean delivery before umbilical herniorrhaphy (HR 1.61, 95% CI 1.34, 1.92) and both vaginal (HR 2.57, 95% CI 1.98, 3.34) and cesarean delivery (HR 2.95, 95% CI 2.25, 3.87) after umbilical herniorrhaphy were associated with increased risk of second herniorrhaphy. Both vaginal (HR 1.66, 95% CI 1.13, 2.43) and cesarean delivery (HR 2.72, 95% CI 2.09, 3.53) after incisional/ventral herniorrhaphy and vaginal delivery after inguinal/femoral herniorrhaphy (HR 1.75, 95% CI 1.22, 2.51) were associated with increased risk of second herniorrhaphy. CONCLUSIONS: Among reproductive-aged women, childbirth, increasing age, comorbidities, smoking, and obesity increase risk of subsequent herniorrhaphy. Risk of second herniorrhaphy is higher with cesarean delivery compared to vaginal delivery, and higher for delivery occurring after initial hernia repair compared to before.

Alirocumab efficacy and safety by body mass index: A pooled analysis from 10 Phase 3 ODYSSEY trials.

AIMS: Increased body mass index (BMI) contributes to cardiovascular risk and may influence efficacy of therapeutic antibodies. We investigated the effect of baseline BMI on efficacy and safety of alirocumab, a PCSK9 monoclonal antibody. METHODS: In a post-hoc analysis, data were pooled from 10 Phase 3 trials (n=4975) of alirocumab vs. placebo/ezetimibe controls. Alirocumab dose was 150mg every 2 weeks in two trials, and 75mg every 2 weeks with possible increase to 150mg at 12 weeks (based on Week 8 low-density lipoprotein cholesterol [LDL-C]) in eight trials. Efficacy/safety data were assessed in baseline BMI subgroups of≤25,>25 to 30,>30 to 35, and>35kg/m2. RESULTS: Baseline LDL-C levels were lower among patients in the higher BMI subgroups. Significant LDL-C reductions from baseline were observed at Weeks 12 and 24 for alirocumab vs. controls, of similar magnitude regardless of baseline BMI (interaction P-value=0.7119). LDL-C<1.81mmol/L (<70mg/dL) was achieved at Week 24 by 69.8-76.4% of alirocumab-treated patients and 9.7-18.4% of control-treated patients, with no pattern by BMI. A greater proportion of patients in higher vs. lower BMI subgroups required alirocumab dose increase (P=0.0343); proportions were 22.5%, 24.9%, 31.7%, and 27.2% of patients across BMI subgroups of≤25,>25 to 30,>30 to 35, and>35kg/m2, respectively. Adverse event frequencies were similar regardless of BMI; injection-site reaction frequency was higher with alirocumab (5.1-8.2% across BMI categories) vs. controls (3.6-4.8%). CONCLUSIONS: Alirocumab provided consistent LDL-C reductions, with similar safety findings across BMI subgroups.

Characterization of cefoxitin-resistant Escherichia coli isolates from recreational beaches and private drinking water in Canada between 2004 and 2006.

A total of 142 cefoxitin-resistant Escherichia coli isolates from water sources were collected across Canada. Multidrug resistance was observed in 65/142 (45.8%) isolates. The bla(CMY-2) gene was identified in 110/142 (77.5%) isolates. Sequencing of the chromosomal ampC promoter region showed mutations from the wild type, previously shown to hyperproduce AmpC. CMY-2-producing plasmids predominantly belonged to replicon groups I1-Igamma, A/C, and K/B. The majority of the E. coli isolates belonged to the nonvirulent phylogenetic groups A and B1.

Requirement for CD8 beta chain in positive selection of CD8-lineage T cells.

CD8 is either an alpha alpha homodimer or an alpha beta heterodimer, although most peripheral CD8-lineage T cells express only the CD8 alpha beta heterodimer. The physiological function of CD8 beta was elucidated with mice that were chimeric for the homozygous disruption of the CD8 beta gene. The CD8 beta-1- T cells developed normally to CD4+CD8+ stage, but did not efficiently differentiate further, which resulted in few peripheral CD8+ T cells. The number of peripheral CD8+ T cells was restored by transfer of an exogenous CD8 beta gene into CD8 beta-deficient T cells. Thus, CD8 beta is necessary for the maturation of CD8+ T cells.

Thymic selection of cytotoxic T cells independent of CD8 alpha-Lck association.

The CD8 alpha cytoplasmic domain associates with p56lck, a nonreceptor protein-tyrosine kinase. The biological relevance of CD8 alpha-Lck association in T cell development was tested with transgenic mice generated to express a CD8 alpha molecule with two amino acid substitutions in its cytoplasmic domain, which abolishes the association of CD8 alpha with Lck. The CD8 alpha mutant was analyzed in a CD8-/- background and in the context of the transgenic 2C T cell receptor. The development and function of CD8+ T cells in these mice were apparently normal. Thus, CD8 alpha-Lck association is not necessary for positive selection, negative selection, or CD8-dependent cytotoxic function.

Disappearance of the lymphoid system in Bcl-2 homozygous mutant chimeric mice.

The bcl-2 proto-oncogene can prevent the death of many cell types. Mice were generated that were chimeric for the homozygous inactivation of bcl-2. Lymphocytes without Bcl-2 differentiated into phenotypically mature cells. However, in vitro, the mature T cells that lacked Bcl-2 had shorter life-spans and increased sensitivity to glucocorticoids and gamma-irradiation. In contrast, stimulation of CD3 inhibited the death of these cells. T and B cells with no Bcl-2 disappeared from the bone marrow, thymus, and periphery by 4 weeks of age. Thus, Bcl-2 was dispensable for lymphocyte maturation, but was required for a stable immune system after birth.

Host range and lytic capability of four bacteriophages against bovine and clinical human isolates of Shiga toxin-producing Escherichia coli O157:H7.

AIMS: To evaluate host range and lytic capability of four bacteriophages (rV5, wV7, wV8 and wV11) against Escherichia coli O157:H7 (STEC O157:H7) from cattle and humans. METHODS AND RESULTS: Four hundred and twenty-two STEC O157:H7 isolates (297 bovine; 125 human) were obtained in Alberta, Canada. The four phages were serially diluted and incubated for 5 h with overnight cultures of STEC O157:H7 to estimate their multiplicity of infection (MOI). All bovine STEC O157:H7 were subjected to pulsed-field gel electrophoresis (PFGE) and phage typing (PT). Phage wV7 lysed all human and bovine isolates irrespective of PFGE genotype or PT phenotype and exhibited the lowest MOI (0.004-0.006, P < 0.0001) of all phages. Phages rV5 and wV11 exhibited a lower MOI (0.002-0.04, P < 0.0001) than did phage wV8 (25-29) and they had a narrower host range than wV7 or wV8. Phages rV5, wV11 and wV8 lysed 342 (81.0%), 321 (76.1%) and 407 (96.4%), respectively, of the 422 isolates. Susceptibility of bovine STEC O157:H7 to rV5, w11 and wV8 was influenced by PFGE genotype and/or PT phenotype. CONCLUSIONS: Phages exhibited activity against the majority of bovine and human STEC O157:H7 isolates. PFGE genotype and/or PT phenotype of the host-target influenced their vulnerability to phage attack. Susceptibility of bovine STEC O157:H7 to phage may also differ among farms. Both lytic capability and host range should be considered in the selection of therapeutic phage for on-farm control of STEC O157:H7. SIGNIFICANCE AND IMPACT OF THE STUDY: The present work indicates that a four-phage cocktail should be equally effective at mitigating STEC O157:H7 isolates both of bovine and of human origin. Given that some STEC O157:H7 exhibited resistance to some but not all phages, a phage cocktail is the logical approach to efficacious on-farm therapy.

Laparoscopic renal surgery.

Renal surgery, radical nephrectomy in particular, was historically the first application of laparoscopic techniques in urology. Since then, laparoscopy has been constantly evolving to claim its position in the surgical armamentarium of the urologist for the treatment of both malignant and benign diseases of the kidney and upper urinary tract. Over the years of increasing surgical experience and exposure, along with the evolution in the techniques and instruments used, laparoscopy has emerged as an equally effective and even more attractive alternative to open surgery for certain indications. The currently available load of literature is able to prove beyond any doubt the oncologic efficacy and minimal morbidity of laparoscopy for the treatment of renal masses in the form of radical or partial laparoscopic nephrectomy and nephroureterectomy. On the other hand, one can claim that laparoscopy is not far from replacing open surgery for the management of benign conditions such as ureteropelvic junction obstruction and donor nephrectomy. This review on laparoscopic renal surgery will discuss the major applications, indications, techniques and outcomes of laparoscopy in the contemporary management of benign and malignant renal diseases while focusing on its benefits and drawbacks compared to open surgery.

LGBT inclusivity in health assessment textbooks.

Lesbian, gay, bisexual, and transgender (LGBT) people make up 4% of the adult population in the United States; however, it is unclear if there is sufficient material in nursing textbooks for students to learn how to provide care for sexual minority populations. A content analysis of two commonly used health assessment textbooks was completed to identify material that prepared nurses for LGBT patient interactions. Topics such as gender neutrality, same-sex partners, and other terms referring to LGBT persons were considered LGBT content. Campinha-Bacote's The Process of Cultural Competence in the Delivery of Healthcare was used as the theoretical framework to assess the textbooks' content on five constructs: awareness, knowledge, skill, encounters, and desire to learn. Eleven pages in one text and 14 in the other had at least one line that addressed LGBT health assessment. Investigators found content related to the constructs of awareness, knowledge, and skill in both textbooks. In all cases, the content was limited in depth; both textbooks lacked exemplars and application of LGBT-specific health content. Inclusion of this information in textbooks or other learning resources is needed to enhance nurses' cultural knowledge and skill to improve health care outcomes within this vulnerable population.