Antitumor activity of a systemic STING-activating non-nucleotide cGAMP mimetic

Stimulator of interferon genes (STING) links innate immunity to biological processes ranging from antitumor immunity to microbiome homeostasis. Mechanistic understanding of the anticancer potential for STING receptor activation is currently limited by metabolic instability of the natural cyclic dinucleotide (CDN) ligands. From a pathway-targeted cell-based screen, we identified a non-nucleotide, small-molecule STING agonist, termed SR-717, that demonstrates broad interspecies and interallelic specificity. A 1.8-angstrom cocrystal structure revealed that SR-717 functions as a direct cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) mimetic that induces the same "closed" conformation of STING. SR-717 displayed antitumor activity; promoted the activation of CD8⁺ T, natural killer, and dendritic cells in relevant tissues; and facilitated antigen cross-priming. SR-717 also induced the expression of clinically relevant targets, including programmed cell death 1 ligand 1 (PD-L1), in a STING-dependent manner.

Oxysterols provide innate immunity to bacterial infection by mobilizing cell surface accessible cholesterol

Cholesterol 25-hydroxylase (CH25H) is an interferon-stimulated gene that converts cholesterol to the oxysterol 25-hydroxycholesterol (25HC). Circulating 25HC modulates essential immunological processes including antiviral immunity, inflammasome activation and antibody class switching; and dysregulation of CH25H may contribute to chronic inflammatory disease and cancer. Although 25HC is a potent regulator of cholesterol storage, uptake, efflux and biosynthesis, how these metabolic activities reprogram the immunological state of target cells remains poorly understood. Here, we used recently designed toxin-based biosensors that discriminate between distinct pools of plasma membrane cholesterol to elucidate how 25HC prevents Listeria monocytogenes from traversing the plasma membrane of infected host cells. The 25HC-mediated activation of acyl-CoA:cholesterol acyltransferase (ACAT) triggered rapid internalization of a biochemically defined fraction of cholesterol, termed 'accessible' cholesterol, from the plasma membrane while having little effect on cholesterol in complexes with sphingomyelin. We show that evolutionarily distinct bacterial species, L. monocytogenes and Shigella flexneri, exploit the accessible pool of cholesterol for infection and that acute mobilization of this pool by oxysterols confers immunity to these pathogens. The significance of this signal-mediated membrane remodelling pathway probably extends beyond host defence systems, as several other biologically active oxysterols also mobilize accessible cholesterol through an ACAT-dependent mechanism.

Entry of Graduates of US Pathology Residency Programs Into the Workforce: Cohort Data Between 2008 and 2016 Remain Positive and Stable

The pathologist workforce in the United States is a topic of interest to the health-care community as a whole and to institutions responsible for the training of new pathologists in particular. Although a pathologist shortage has been projected, there has been a pervasive belief by medical students and their advisors that there are “no jobs in pathology.” In 2013 and again in 2017, the Program Directors Section of the Association of Pathology Chairs conducted surveys asking pathology residency directors to report the employment status of each of their residents graduating in the previous 5 years. The 2013 Program Directors Section survey indicated that 92% of those graduating in 2010 had obtained employment within 3 years, and 94% of residents graduating in 2008 obtained employment within 5 years. The 2017 survey indicated that 96% of those graduating in 2014 had obtained employment in 3 years, and 97% of residents graduating in 2012 obtained positions within 5 years. These findings are consistent with residents doing 1 or 2 years of fellowship before obtaining employment. Stratification of the data by regions of the country or by the size of the residency programs does not show large differences. The data also indicate a high percentage of employment for graduates of pathology residency programs and a stable job market over the years covered by the surveys.

Molecular Analysis of Membrane Targeting by the C2 Domain of the E3 Ubiquitin Ligase Smurf1

SMAD ubiquitination regulatory factor 1 (Smurf1) is a Nedd4 family E3 ubiquitin ligase that regulates cell motility, polarity and TGFβ signaling. Smurf1 contains an N-terminal protein kinase C conserved 2 (C2) domain that targets cell membranes and is required for interactions with membrane-localized substrates such as RhoA. Here, we investigated the lipid-binding mechanism of Smurf1 C2, revealing a general affinity for anionic membranes in addition to a selective affinity for phosphoinositides (PIPs). We found that Smurf1 C2 localizes not only to the plasma membrane but also to negatively charged intracellular sites, acting as an anionic charge sensor and selective PIP-binding domain. Site-directed mutagenesis combined with docking/molecular dynamics simulations revealed that the Smurf1 C2 domain loop region primarily interacts with PIPs and cell membranes, as opposed to the β-surface cationic patch employed by other C2 domains. By depleting PIPs from the inner leaflet of the plasma membrane, we found that PIP binding is necessary for plasma membrane localization. Finally, we used a Smurf1 cellular ubiquitination assay to show that the amount of ubiquitin at the plasma membrane interface depends on the lipid-binding properties of Smurf1. This study shows the mechanism by which Smurf1 C2 targets membrane-based substrates and reveals a novel interaction for non-calcium-dependent C2 domains and membrane lipids.

Gender Parity in Gainful Employment and Other Gender Trends in the Job Market for Recent Pathology Graduates

Context.—

Gender-based barriers to equal salary, career advancement, and leadership still exist in medicine. Herein we provide the first report of data comparing the experiences of men and women seeking their first nonfellowship position in pathology.

Objective.—

To identify gender trends regarding pathologists taking their first job after training and the relationship to various demographic factors, job search satisfaction, and outcome.

Design.—

Aggregate data from the College of American Pathologists Graduate Medical Education Committee Job Market surveys (2015–2018) were analyzed across multiple domains including residency focus, number and subspecialty of fellowships completed, and extent to which expectations were met in regard to work duties, geographic preference, benefits, and salary. These data were examined in the context of assessing gender-based differences.

Results.—

Comparable results were identified in all measured outcomes according to gender. There were no differences between gender and medical school type, relocation, residency training focus, number of fellowships completed, overall satisfaction with position accepted, salary, or extent to which the position met expectations. Similarly, there were also no discrepancies between gender and the geographic region in which positions were accepted, practice setting, practice subspecialty, partnership track, length of job search, or difficulty finding a position.

Conclusions.—

Analysis from 4 years of job market survey data shows equivalent results between men and women looking for their first nonfellowship position in pathology. There were no significant differences with regard to difficulty finding a position, overall satisfaction with the position accepted, salary, benefits, or access to partnership track.

PSXI-4 Composting management to reduce greenhouse gas and ammonia emissions from feedlot manure

Management of livestock manure may recycle nutrients and decrease greenhouse gas (GHG) and ammonia (NH3) emissions. The objectives were to ascertain effects of environmental conditions and turning on methane (CH4), nitrous oxide (N2O), and NH3 emissions and if treatment with 8.5 g of dicyandiamide (DCD), a denitrification agent, altered GHG emissions. Manure and bedding were collected from feedlot pens and used to construct 3 piles (~1.9 m3 volume) each in winter (WI) and spring (SP). WI piles were turned once, and SP piles were turned twice. Methane, N2O, and NH3 emissions were collected. Methane and N2O flux measurements were collected from SP piles using a static chamber (3.7m L x 2.2m W x 0.9m H). Initial dry matter and nitrogen contents were 33.2 and 30.0% and 20.1 and 17.7 g/kg in WI and SP piles, respectively. Average ambient temperatures and wind speeds were 0.3oC and 10.7oC and 1.76 m/s and 1.97 m/s during WI and SP, respectively. Internal temperatures reached 51±3.9oC on d 4–11 and gradually decreased. Normalized CH4 averaged 2.19 mg٠s٠m-4 and N2O emissions averaged 0.84 mg٠s٠m-4, and were not different between the WI and SP piles. Turning did not affect CH4 emissions from WI piles, but were 55% greater (P < 0.05) when SP piles were turned a second time. Emissions of N2O increased 51% when WI and SP piles were turned (P < 0.05). Ammonia emissions were 83.5% greater from WI piles due to their higher initial concentrations of NH4+-N (2.21 vs. 1.11 g/kg; P < 0.05). Turning did not influence CH4 and N2O fluxes. Addition of DCD at pile formation appears to decrease N2O emissions and fluxes 3 and 10 d later. Turning management and season impacted overall CH4, N2O, and NH3 emissions. Fine-tuning manure handling and management during different seasons may effectively reduce GHG and NH3 emissions.

Associations between residual feed intake and apparent nutrient digestibility, in vitro methane-producing activity, and volatile fatty acid concentrations in growing beef cattle1

The objectives of this study were to examine the relationship between residual feed intake (RFI) and DM and nutrient digestibility, in vitro methane production, and volatile fatty acid (VFA) concentrations in growing beef cattle. Residual feed intake was measured in growing Santa Gertrudis steers (Study 1; n = 57; initial BW = 291.1 ± 33.8 kg) and Brangus heifers (Study 2; n = 468; initial BW = 271.4 ± 26.1 kg) fed a high-roughage-based diet (ME = 2.1 Mcal/kg DM) for 70 d in a Calan-gate feeding barn. Animals were ranked by RFI based on performance and feed intake measured from day 0 to 70 (Study 1) or day 56 (Study 2) of the trial, and 20 animals with the lowest and highest RFI were identified for subsequent collections of fecal and feed refusal samples for DM and nutrient digestibility analysis. In Study 2, rumen fluid and feces were collected for in vitro methane-producing activity (MPA) and VFA analysis in trials 2, 3, and 4. Residual feed intake classification did not affect BW or BW gain (P > 0.05), but low-RFI steers and heifers both consumed 19% less (P < 0.01) DMI compared with high-RFI animals. Steers with low RFI tended (P < 0.1) to have higher DM digestibility (DMD) compared with high-RFI steers (70.3 vs. 66.5 ± 1.6% DM). Heifers with low RFI had 4% higher DMD (76.3 vs. 73.3 ± 1.0% DM) and 4 to 5% higher (P < 0.01) CP, NDF, and ADF digestibility compared with heifers with high RFI. Low-RFI heifers emitted 14% less (P < 0.01) methane (% GE intake; GEI) calculated according to Blaxter and Clapperton (1965) as modified by Wilkerson et al. (1995), and tended (P = 0.09) to have a higher rumen acetate:propionate ratio than heifers with high RFI (GEI = 5.58 vs. 6.51 ± 0.08%; A:P ratio = 5.02 vs. 4.82 ± 0.14%). Stepwise regression analysis revealed that apparent nutrient digestibilities (DMD and NDF digestibility) for Study 1 and Study 2 accounted for an additional 8 and 6%, respectively, of the variation in intake unaccounted for by ADG and mid-test BW0.75. When DMD, NDF digestibility, and total ruminal VFA were added to the base model for Study 2, trials 2, 3, and 4, the R2 increased from 0.33 to 0.47, explaining an additional 15% of the variation in DMI unrelated to growth and body size. On the basis of the results of these studies, differences in observed phenotypic RFI in growing beef animals may be a result of inter-animal variation in apparent nutrient digestibility and ruminal VFA concentrations.

Cholesterol accessibility at the ciliary membrane controls hedgehog signaling

Previously we proposed that transmission of the hedgehog signal across the plasma membrane by Smoothened is triggered by its interaction with cholesterol (Luchetti et al., 2016). But how is cholesterol, an abundant lipid, regulated tightly enough to control a signaling system that can cause birth defects and cancer? Using toxin-based sensors that distinguish between distinct pools of cholesterol, we find that Smoothened activation and Hedgehog signaling are driven by a biochemically-defined, small fraction of membrane cholesterol, termed accessible cholesterol. Increasing cholesterol accessibility by depletion of sphingomyelin, which sequesters cholesterol in complexes, amplifies Hedgehog signaling. Hedgehog ligands increase cholesterol accessibility in the membrane of the primary cilium by inactivating the transporter-like protein Patched 1. Trapping this accessible cholesterol blocks Hedgehog signal transmission across the membrane. Our work shows that the organization of cholesterol in the ciliary membrane can be modified by extracellular ligands to control the activity of cilia-localized signaling proteins.

Ostreolysin A and anthrolysin O use different mechanisms to control movement of cholesterol from the plasma membrane to the endoplasmic reticulum

Recent studies using two cholesterol-binding bacterial toxin proteins, perfringolysin O (PFO) and domain 4 of anthrolysin O (ALOD4), have shown that cholesterol in the plasma membranes (PMs) of animal cells resides in three distinct pools. The first pool comprises mobile cholesterol, accessible to both PFO and ALOD4, that is rapidly transported to the endoplasmic reticulum (ER) to signal cholesterol excess and maintain cholesterol homeostasis. The second is a sphingomyelin (SM)-sequestered pool inaccessible to PFO and ALOD4 but that becomes accessible by treatment with SM-degrading sphingomyelinase (SMase). The third is an essential pool also inaccessible to PFO and ALOD4 that cannot be liberated by SMase treatment. The accessible cholesterol pool can be trapped on PMs of live cells by nonlytic ALOD4, blocking its transport to the ER. However, studies of the two other pools have been hampered by a lack of available tools. Here, we used ostreolysin A (OlyA), which specifically binds SM/cholesterol complexes in membranes, to study the SM-sequestered cholesterol pool. Binding of nonlytic OlyA to SM/cholesterol complexes in PMs of live cells depleted the accessible PM cholesterol pool detectable by ALOD4. Consequently, transport of accessible cholesterol from PM to ER ceased, thereby activating SREBP transcription factors and increasing cholesterol synthesis. Thus, OlyA and ALOD4 both control movement of PM cholesterol, but through different lipid-binding mechanisms. We also found that PM-bound OlyA was rapidly internalized into cells, whereas PM-bound ALOD4 remained on the cell surface. Our findings establish OlyA and ALOD4 as complementary tools to investigate cellular cholesterol transport.

Will I Need to Move to Get My First Job?: Geographic Relocation and Other Trends in the Pathology Job Market

Context.—

There is an ongoing perception that the pathology job market is poor, which may be discouraging medical students from pursuing the specialty. Academic pathologists believe that jobs are available but relocation may be necessary.

Objective.—

To identify trends regarding the geographic relocation of pathologists taking their first job after training.

Design.—

The College of American Pathologists (CAP) Graduate Medical Education Committee has sent an annual job search survey from 2012–2016 to CAP junior members and fellows in practice for 3 years or less and seeking their first job. Data were analyzed across demographics and geographic domains consisting of the following: stayed at same institution/city, relocated within the same region, or relocated to a different region. Standard statistical methods were used.

Results.—

Of 501 respondents, 421 reported completing combined anatomic pathology (AP)/clinical pathology (CP) training, while 80 reported AP- or CP-only training. Of the 421 AP/CP respondents, 109 (26%) stayed at the same institution or city, while of the 80 AP- or CP-only respondents, 36 (45%) stayed at the same institution or city. One hundred ninety-nine respondents completed surgical pathology fellowships with 124 (62%) general/oncologic surgical pathology and 75 (38%) subspecialty surgical pathology trainees. Job seekers who completed general surgical pathology/surgical oncologic pathology fellowship accounted for 34 of 52 (65%) of those remaining at the same institution or city, while those with subspecialty training accounted for 40 of 77 (52%) of those relocating to a different region. Relocation did not demonstrate any significant trends in regard to other demographics studied.

Conclusions.—

The pathology job market appears stable with no precedent for geographic hardship.

Using In Vitro and In-cell SHAPE to Investigate Small Molecule Induced Pre-mRNA Structural Changes

In the process of drug development of RNA-targeting small molecules, elucidating the structural changes upon their interactions with target RNA sequences is desired. We herein provide a detailed in vitro and in-cell selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) protocol to study the RNA structural change in the presence of an experimental drug for spinal muscular atrophy (SMA), survival of motor neuron (SMN)-C2, and in exon 7 of the pre-mRNA of the SMN2 gene. In in vitro SHAPE, an RNA sequence of 140 nucleotides containing SMN2 exon 7 is transcribed by T7 RNA polymerase, folded in the presence of SMN-C2, and subsequently modified by a mild 2'-OH acylation reagent, 2-methylnicotinic acid imidazolide (NAI). This 2'-OH-NAI adduct is further probed by a ³²P-labeled primer extension and resolved by polyacrylamide gel electrophoresis (PAGE). Conversely, 2'-OH acylation in in-cell SHAPE takes place in situ with SMN-C2 bound cellular RNA in living cells. The pre-mRNA sequence of exon 7 in the SMN2 gene, along with SHAPE-induced mutations in the primer extension, was then amplified by PCR and subject to next-generation sequencing. Comparing the two methodologies, in vitro SHAPE is a more cost-effective method and does not require computational power to visualize results. However, the in vitro SHAPE-derived RNA model sometimes deviates from the secondary structure in a cellular context, likely due to the loss of all interactions with RNA-binding proteins. In-cell SHAPE does not need a radioactive material workplace and yields a more accurate RNA secondary structure in the cellular context. Furthermore, in-cell SHAPE is usually applicable for a larger range of RNA sequences (~1,000 nucleotides) by utilizing next-generation sequencing, compared to in vitro SHAPE (~200 nucleotides) that usually relies on PAGE analysis. In case of exon 7 in SMN2 pre-mRNA, the in vitro and in-cell SHAPE derived RNA models are similar to each other.

The effect of encapsulated nitrate and monensin on ruminal fermentation using a semi-continuous culture system

Because enteric methane (CH4) production from ruminants represents a source of greenhouse gas emissions and an energy loss for the host animal alternatives to minimize emissions is a current research priority. Seven 37-d trials tested the effect of encapsulated nitrate (EN) and sodium monensin (MON) in diets commonly fed to dairy (DAIRY; 50:50 forage to concentrate; four trials) and beef cattle (BEEF; 15:85 forage to concentrate; three trials) on rumen fermentation and CH4 production using a semi-continuous fermentation system. A 3 × 2 factorial arrangement was used and additives (0, 1.25, and 2.5% of EN; 0 and 4 mg/L of MON) were tested alone and combined (EN + MON) totaling six treatments. Rumen fluid was pooled from five nonadapted lactating cows fed 50:50 forage to concentrate diet 3 h after morning feeding, and 1 L of processed inoculum was transferred to 2.2-L vessels. Treatment diets were added to nylon bags which remained in the anaerobic fermentation of mixed rumen microorganisms for 48 h. Nitrate decreased CH4 production in DAIRY (24.7 vs. 32.1 mM/d; P < 0.01) and BEEF trials (33.5 vs. 43.5 mM/d; P < 0.01). Methane production was decreased by MON in DAIRY (26.3 vs. 32.1; P < 0.01) and BEEF (26.6 vs. 43.5 mM/d; P < 0.01). The combination of EN + MON further decreased CH4 in DAIRY (21.3 vs. 32.1 mM/d; P = 0.03) and BEEF (19.3 vs. 43.5 mM/d; P = 0.01). Nitrate did not affect major VFA production in DAIRY and BEEF trials, but significantly decreased digestion of protein (96.8 vs. 97.6%; P < 0.01) and starch (79.0 vs. 80.4%; P < 0.01) in DAIRY and NDF (29.3 vs. 32.5%; P < 0.01) and starch (88.5 vs. 90.3%; P < 0.01) in BEEF. Monensin significantly affected VFA pattern with an increase in propionate (P < 0.01) and a decrease on acetate (P < 0.01) production with consequent decrease on acetate-to-propionate ratio in DAIRY (1.6 vs. 2.0; P < 0.01) and BEEF (1.6 vs. 1.9; P < 0.01). Monensin decreased NDF digestion in BEEF only (29.3 vs. 32.5 %; P < 0.01). Significant concentrations of nitrate and nitrite were detected only for EN and EN + MON (P < 0.01). Nitrate and MON effectively decreased CH4 production when fed separately and the combination of additives additively decreased CH4 production.

Receptor-interacting Ser/Thr kinase 1 (RIPK1) and myosin IIA-dependent ceramidosomes form membrane pores that mediate blebbing and necroptosis

Formation of membrane pores/channels regulates various cellular processes, such as necroptosis or stem cell niche signaling. However, the roles of membrane lipids in the formation of pores and their biological functions are largely unknown. Here, using the cellular stress model evoked by the sphingolipid analog drug FTY720, we show that formation of ceramide-enriched membrane pores, referred to here as ceramidosomes, is initiated by a receptor-interacting Ser/Thr kinase 1 (RIPK1)-ceramide complex transported to the plasma membrane by nonmuscle myosin IIA-dependent trafficking in human lung cancer cells. Molecular modeling/simulation coupled with site-directed mutagenesis revealed that Asp¹⁴⁷ or Asn¹⁶⁹ of RIPK1 are key for ceramide binding and that Arg²⁵⁸ or Leu²⁹³ residues are involved in the myosin IIA interaction, leading to ceramidosome formation and necroptosis. Moreover, generation of ceramidosomes independently of any external drug/stress stimuli was also detected in the plasma membrane of germ line stem cells in ovaries during the early stages of oogenesis in Drosophila melanogaster Inhibition of ceramidosome formation via myosin IIA silencing limited germ line stem cell signaling and abrogated oogenesis. In conclusion, our findings indicate that the RIPK1-ceramide complex forms large membrane pores we named ceramidosomes. They further suggest that, in addition to their roles in stress-mediated necroptosis, these ceramide-enriched pores also regulate membrane integrity and signaling and might also play a role in D. melanogaster ovary development.

Neurofibroma of the ulnar nerve in the carpal canal in a dog: treatment by marginal neurectomy

Peripheral nerve sheath tumours arising in the plexus or peripheral nerves can be treated by limb amputation. There are few reports of these tumours affecting peripheral nerves in the distal regions of the limbs. Here we describe a case of neurofibroma affecting the palmar branch of the ulnar nerve in an Irish setter. Surgical treatment in the region of the carpus by ulnar neurectomy resulted in resolution of chronic thoracic limb lameness. At 11 months following the surgery, clinical examination and MRI did not detect any evidence of recurrence. Neurectomy may be a feasible option for management of selected cases of distally located peripheral nerve sheath tumours.

Mechanistic studies of a small-molecule modulator of SMN2 splicing

RG-7916 is a first-in-class drug candidate for the treatment of spinal muscular atrophy (SMA) that functions by modulating pre-mRNA splicing of the SMN2 gene, resulting in a 2.5-fold increase in survival of motor neuron (SMN) protein level, a key protein lacking in SMA patients. RG-7916 is currently in three interventional phase 2 clinical trials for various types of SMA. In this report, we show that SMN-C2 and -C3, close analogs of RG-7916, act as selective RNA-binding ligands that modulate pre-mRNA splicing. Chemical proteomic and genomic techniques reveal that SMN-C2 directly binds to the AGGAAG motif on exon 7 of the SMN2 pre-mRNA, and promotes a conformational change in two to three unpaired nucleotides at the junction of intron 6 and exon 7 in both in vitro and in-cell models. This change creates a new functional binding surface that increases binding of the splicing modulators, far upstream element binding protein 1 (FUBP1) and its homolog, KH-type splicing regulatory protein (KHSRP), to the SMN-C2/C3-SMN2 pre-mRNA complex and enhances SMN2 splicing. These findings underscore the potential of small-molecule drugs to selectively bind RNA and modulate pre-mRNA splicing as an approach to the treatment of human disease.

Consistency of feed efficiency ranking and mechanisms associated with inter-animal variation among growing calves

This study investigated the possible mechanisms for explaining interanimal variation in efficiency of feed utilization in intact male Holstein calves. Additionally, we examined whether the feed efficiency (FE) ranking of calves (n = 26) changed due to age and/or diet quality. Calves were evaluated during three periods (P1, P2, and P3) while fed a high-quality diet (calculated mobilizable energy [ME] of 11.8 MJ/kg DM) during P1 and P3, and a low-quality diet (calculated ME of 7.7 MJ/kg DM) during P2. The study periods were 84, 119, and 127 d, respectively. Initial ages of the calves in P1, P2, and P3 were 7, 11, and 15 mo, respectively, and initial body weight (BW) were 245, 367, and 458 kg, respectively. Individual dry matter intake (DMI), average daily gain (ADG), diet digestibility, and heat production (HP) were measured in all periods. The measured FE indexes were: residual feed intake (RFI), the gain-to-feed ratio (G:F), residual gain (RG), residual gain and intake (RIG), the ratio of HP-to-ME intake (HP/MEI), and residual heat production (RHP). For statistical analysis, animals' performance data in each period, were ranked by RFI, and categorized into high-, medium-, and low-RFI groups (H-RFI, M-RFI, and L-RFI). RFI was not correlated with in vivo digestibility, age, BW, BCS, or ADG in all three periods. The L-RFI group had lowest DMI, MEI, HP, retained energy (RE), and RE/ADG. Chemical analysis of the longissimus dorsi muscle shows that the L-RFI group had a higher percentage of protein and a lower percentage of fat compared to the H-RFI group. We suggested that the main mechanism separating L- from H-RFI calves is the protein-to-fat ratio in the deposited tissues. When efficiency was related to kg/day (DMI and ADG) and not to daily retained energy, the selected efficient L-RFI calves deposited more protein and less fat per daily gain than less efficient H-RFI calves. However, when the significant greater heat increment and maintenance energy requirement of protein compared to fat deposition in tissue were considered, we could not exclude the hypothesis that variation in efficiency is partly explained by efficient energy utilization. The ranking classification of calves to groups according to their RFI efficiency was independent of diet quality and age.

The Recent Pathology Residency Graduate Job Search Experience: A Synthesis of 5 Years of College of American Pathologists Job Market Surveys

CONTEXT

- Pathology residents and fellows tailor their training and job search strategies to an actively evolving specialty in the setting of scientific and technical advances and simultaneous changes in health care economics.

OBJECTIVE

- To assess the experience and outcome of the job search process of pathologists searching for their first non-fellowship position.

DESIGN

- The College of American Pathologists (CAP) Graduate Medical Education Committee has during the past 5 years sent an annual job search survey each June to CAP junior members and fellows in practice 3 years or less who have actively searched for a non-fellowship position.

RESULTS

- Job market indicators including job interviews, job offers, positions accepted, and job satisfaction have remained stable during the 5 years of the survey. Most survey respondents who had applied for at least 1 position had accepted a position at the time of the survey, and most applicants who had accepted a position were satisfied or very satisfied. However, most attested that finding a non-fellowship position was difficult. Despite a perceived push toward subspecialization in surgical pathology, the reported number of fellowships completed was stable. Respondent demographics were not associated with job search success with 1 significant exception: international medical school graduate respondents reported greater perceived difficulty in finding a position, and indeed, fewer reported having accepted a position.

CONCLUSIONS

- Pathology residents and fellows seeking their first position have faced a relatively stable job market during the last 5 years, with most accepting positions with which they were satisfied.

The haematoma and its role in bone healing

Fracture treatment is an old endeavour intended to promote bone healing and to also enable early loading and regain of function in the injured limb. However, in today's clinical routine the healing potential of the initial fracture haematoma is still not fully recognized. The Arbeitsgemeinschaft für Osteosynthesefragen (AO) formed in Switzerland in 1956 formulated four AO principles of fracture treatment which are still valid today. Fracture treatment strategies have continued to evolve further, as for example the relatively new concept of minimally invasive plate osteosynthesis (MIPO). This MIPO treatment strategy harbours the benefit of an undisturbed original fracture haematoma that supports the healing process. The extent of the supportive effect of this haematoma for the bone healing process has not been considered in clinical practice so far. The rising importance of osteoimmunological aspects in bone healing supports the essential role of the initial haematoma as a source for inflammatory cells that release the cytokine pattern that directs cell recruitment towards the injured tissue. In reviewing the potential benefits of the fracture haematoma, the early development of angiogenic and osteogenic potentials within the haematoma are striking. Removing the haematoma during surgery could negatively influence the fracture healing process. In an ovine open tibial fracture model the haematoma was removed 4 or 7 days after injury and the bone that formed during the first two weeks of healing was significantly reduced in comparison with an undisturbed control. These findings indicate that whenever possible the original haematoma formed upon injury should be conserved during clinical fracture treatment to benefit from the inherent healing potential.

Graphene-VP40 interactions and potential disruption of the Ebola virus matrix filaments

Ebola virus infections cause hemorrhagic fever that often results in very high fatality rates. In addition to exploring vaccines, development of drugs is also essential for treating the disease and preventing the spread of the infection. The Ebola virus matrix protein VP40 exists in various conformational and oligomeric forms and is a potential pharmacological target for disrupting the virus life-cycle. Here we explored graphene-VP40 interactions using molecular dynamics simulations and graphene pelleting assays. We found that graphene sheets associate strongly with VP40 at various interfaces. We also found that the graphene is able to disrupt the C-terminal domain (CTD-CTD) interface of VP40 hexamers. This VP40 hexamer-hexamer interface is crucial in forming the Ebola viral matrix and disruption of this interface may provide a method to use graphene or similar nanoparticle based solutions as a disinfectant that can significantly reduce the spread of the disease and prevent an Ebola epidemic.

Identification of loci associated with susceptibility to subspecies () tissue infection in cattle

Johne's disease is a contagious bacterial infection of cattle caused by ssp. (). A previous genome-wide association analysis (GWAA) in Holstein cattle identified QTL on BTA3 and BTA9 that were highly associated (P < 5 × 10) and on BTA1, BTA16, and BTA21 that were moderately associated (P < 5 × 10) with Map tissue infection. The objectives of this study were to validate previous GWAA results in Jersey cattle ( = 57), Holstein cattle from the Pacific Northwest (PNW, = 205) and a combined Holstein population from the PNW and the Northeast (PNW + NE, = 423), and also identify new loci associated with tissue infection. DNA was genotyped using the Illumina BovineSNP50 BeadChip, and the PNW + NE data was also imputed to whole genome sequence level using Run4 of the 1000 Bull Genomes project with Beagle v 4.1 and FImpute. Cases were ileocecal node positive and controls were negative for by quantitative PCR (qPCR). Individuals were removed for SNP call rate < 90%, and SNP were removed for genotype call rate < 90% or minor allele frequency < 1%. For the Jersey, PNW, and PNW + NE, GWAA were conducted using an allelic dosage model. For the PNW and the PNW + NE, an additional efficient mixed-model association eXpedited (EMMAX) analysis was performed using additive, dominance and recessive models. Seven QTL on BTA22 were identified in the Jersey population with the most significant ( = 4.45 × 10) located at 21.7 megabases (Mb). Six QTL were associated in the PNW and the PNW + NE analyses, including a QTL previously identified on BTA16 in the NE population. The most significant locus for the PNW was located on BTA21 at 61 Mb ( = 8.61 × 10) while the most significant locus for the PNW + NE was on BTA12 at 90 Mb ( = 2.33 × 10). No additional QTL were identified with the imputed GWAA. Putative positional candidate genes were identified within 50 kb 5' and 3' of each QTL. Two positional candidate genes were identified in Jersey cattle, 1 identified in the PNW and 8 in the PNW + NE populations. Many identified positional candidate genes are involved in signal transduction, have immunological functions, or have putative functional relevance in entry into host cells. This study supported 2 previously identified SNP within a QTL on BTA16 and identified 16 new QTL, including 2 found in the PNW and the PNW+NE, associated with tissue infection.

Perceptions of Unprofessional Attitudes and Behaviors: Implications for Faculty Role Modeling and Teaching Professionalism During Pathology Residency

CONTEXT

- Changes occurring in medicine have raised issues about medical professionalism. Professionalism is included in the Core Competencies and Milestones for all pathology residents. Previous studies have looked at resident professionalism attitudes and behaviors in primary care but none have looked specifically at pathology.

OBJECTIVE

- To examine behavior and attitudes toward professionalism within pathology and to determine how professionalism is taught in residency programs.

DESIGN

- Surveys were sent to all College of American Pathologists junior members and all pathology residency program directors, and responses were compared.

RESULTS

- Although no single behavior received the same professionalism rating among residents and program directors, both groups identified the same behaviors as being the most unprofessional: posting identifiable patient information or case images to social media, making a disparaging comment about a physician colleague or member of the support staff on social media or in a public hospital space, and missing work without reporting the time off. Faculty were observed displaying most of these behaviors as often or more often than residents by both groups. The most common means to teach professionalism in pathology residencies is providing feedback as situations arise and teaching by example. Age differences were found within each group and between groups for observed behaviors and attitudes.

CONCLUSIONS

- As teaching by example was identified as a common educational method, faculty must be aware of the role their behavior and attitudes have in shaping resident behavior and attitudes. These results suggest a need for additional resources to teach professionalism during pathology residency.

Decarboxylative borylation

The widespread use of alkyl boronic acids and esters is frequently hampered by the challenges associated with their preparation. We describe a simple and practical method to rapidly access densely functionalized alkyl boronate esters from abundant carboxylic substituents. This broad-scope nickel-catalyzed reaction uses the same activating principle as amide bond formation to replace a carboxylic acid moiety with a boronate ester. Application to peptides allowed expedient preparations of α-amino boronic acids, often with high stereoselectivity, thereby facilitating synthesis of the alkyl boronic acid drugs Velcade and Ninlaro as well as a boronic acid version of the iconic antibiotic vancomycin. The reaction also enabled the discovery and extensive biological characterization of potent human neutrophil elastase inhibitors, which offer reversible covalent binding properties.