Abstract
Background
In sub-Saharan Africa, recent graduates from medical school provide more direct surgical and procedural care to patients than their counterparts from the Global North. Nigeria has ...no nationally representative data on the procedures performed by trainees before graduation from medical school and their confidence in performing these procedures upon graduation has also not been evaluated.
Methods
We performed an internet-based, cross-sectional survey of recent medical school graduates from 15 accredited Federal, State, and private Nigerian medical schools spanning six geopolitical zones. Essential surgical procedures, bedside interventions and three Bellwether procedures were incorporated into the survey. Self-reported confidence immediately after graduation was calculated and compared using cumulative confidence scores with subgroup analysis of results by type and location of institution. Qualitative analysis of free text recommendations by participants was performed using the constant comparative method in grounded theory.
Results
Four hundred ninety-nine recent graduates from 6 geopolitical zones participated, representing 15 out of a total of 44 medical schools in Nigeria. Male to female ratio was 2:1, and most respondents (59%) graduated from Federal institutions. Students had greatest practical mean exposure to bedside procedures like intravenous access and passing urethral foley catheters and were most confident performing these. Less than 23% had performed over 10 of any of the assessed procedures.
They had least exposures to chest tube insertion (0.24/person), caesarean Sect. (0.12/person), and laparotomy (0.09/person). Recent graduates from Federal institutions had less procedural exposure in urethral catheterization (
p
< 0.001), reduction (
p
= 0.035), and debridement (
p
< 0.035).
Respondents that studied in the underserved North-East and North-West performed the highest median number of procedures prior to graduation. Cumulative confidence scores were low across all graduates (maximum 25/60), but highest in graduates from Northern Nigeria and private institutions. Graduates recommended prioritizing medical students over senior trainees, using simulation-based training and constructive individualized non-toxic feedback from faculty.
Conclusion
Nigerian medical students have poor exposure to procedures and low confidence in performing basic procedures after graduation. More attention should be placed on training for essential surgeries and procedures in medical schools.
ABSTRACT
We study the δ Scuti – red giant (RG) binary KIC 9773821, the first double-pulsator binary of its kind. It was observed by Kepler during its 4-yr mission. Our aims are to ascertain whether ...the system is bound, rather than a chance alignment, and to identify the evolutionary state of the RG via asteroseismology. An extension of these aims is to determine a dynamical mass and an age prior for a δ Sct star, which may permit mode identification via further asteroseismic modelling. We determine spectroscopic parameters and radial velocities (RVs) for the RG component using HERMES@Mercator spectroscopy. Light arrival-time delays from the δ Sct pulsations are used with the red-giant RVs to determine that the system is bound and to infer its orbital parameters, including the binary mass ratio. We use asteroseismology to model the individual frequencies of the red giant to give a mass of $2.10^{+0.20}_{-0.10}$ M⊙ and an age of $1.08^{+0.06}_{-0.24}$ Gyr. We find that it is a helium-burning secondary clump star, confirm that it follows the standard $\nu _{\rm max}$ scaling relation, and confirm its observed period spacings match their theoretical counterparts in the modelling code mesa. Our results also constrain the mass and age of the δ Sct star. We leverage these constraints to construct δ Sct models in a reduced parameter space and identify four of its five pulsation modes.
Typical yields of TFE obtained from pyrolysis of potassium pentafluoropropionate obtained from the acid-base neutralization method are >98%.
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•Equimolar mixtures of tetrafluoroethylene ...and carbon dioxide were prepared.•Higher yields of TFE than previous literature reports by this route are reported.•The method based on the pyrolysis of potassium pentafluoropropionate is preferred.•A higher purity of the tetrafluoroethylene/carbon dioxide mixture was obtained.•This method of preparation of tetrafluoroethylene is suitable for academic institutions.
The use of tetrafluoroethylene (TFE) in academic institutions beyond a few millimoles has often been inhibited by the compound's inherent danger and general lack of commercial availability. On the other hand, TFE is prepared industrially on a rather large scale by a number of major fluorochemical companies via the pyrolysis of chlorodifluoromethane at high temperatures, yielding TFE and HCl. For a few years at The University of Alabama and Clemson University, we have been preparing TFE on a 100+-gram scale by the pyrolysis under dynamic vacuum of pentafluoropropionate salts, which can be obtained from the neutralization of pentafluoropropionic acid with a M(OH)n (where M=Li, Na, K, and Cs for n=1 and Mg, Ca, and Ba for n=2). Additionally, potassium pentafluoropropionate can be prepared from the reaction of potassium trimethylsilanolate and ethyl pentafluoropropionate. The pentafluoropropionate salts and their decomposition products have been characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), accelerating rate calorimetry (ARC), nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, Fourier transform-infrared (FTIR) spectrophotometry, scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDAX), X-ray diffraction (XRD), and single-crystal X-ray crystallography, where applicable. Typical yields of TFE obtained from pyrolysis of potassium pentafluoropropionate obtained from the acid-base neutralization method are >98%, while yields of TFE from the same salt prepared by the silanolate method from ethyl pentafluoropropionate are ca. 80%.
B-cell acute lymphoblastic leukemia (B-ALL) occurs most commonly in children, whereas chronic myeloid leukemia is more frequent in adults. The myeloid bias of hematopoiesis in elderly individuals has ...been considered causative, but the age of the bone marrow microenvironment (BMM) may be contributory. Using various murine models of B-ALL in young vs old mice, we recapitulated B-ALL preponderance in children vs adults. We showed differential effects of young vs old BM macrophages on B-ALL cell function. Molecular profiling using RNA- and ATAC-sequencing revealed pronounced differences in young vs old BMM-derived macrophages and enrichment for gene sets associated with inflammation. In concordance with the role of C-X-C motif chemokine (CXCL) 13 for disease-associated B-cell chemoattraction, we found CXCL13 to be highly expressed in young macrophages on a translational compared with a transcriptional level. Inhibition of CXCL13 in BM macrophages impaired leukemia cell migration and decreased the proliferation of cocultured B-ALL cells, whereas recombinant CXCL13 increased pAKT and B-ALL cell expansion. Pretreatment of B-ALL-initiating cells with CXCL13 accelerated B-ALL progression. Deficiency of Cxcr5, the receptor for CXCL13, on B-ALL-initiating cells prolonged murine survival, whereas high expression of CXCR5 in pediatric B-ALL may predict central nervous system relapse. CXCL13 staining was increased in bone sections from pediatric compared with adult patients with B-ALL. Taken together, our study shows that the age of the BMM and, in particular, BM macrophages influence the leukemia phenotype. The CXCR5-CXCL13 axis may act as prognostic marker and an attractive novel target for the treatment of B-ALL.
Unravelling the interaction of biological macromolecules with ligands and substrates at high spatial and temporal resolution remains a major challenge in structural biology. The development of serial ...crystallography methods at X-ray free-electron lasers and subsequently at synchrotron light sources allows new approaches to tackle this challenge. Here, a new polyimide tape drive designed for mix-and-diffuse serial crystallography experiments is reported. The structure of lysozyme bound by the competitive inhibitor chitotriose was determined using this device in combination with microfluidic mixers. The electron densities obtained from mixing times of 2 and 50 s show clear binding of chitotriose to the enzyme at a high level of detail. The success of this approach shows the potential for high-throughput drug screening and even structural enzymology on short timescales at bright synchrotron light sources.
The tetra(ethylene glycol) derivative of benzothiazole aniline, BTA-EG4, is a novel amyloid-binding small molecule that can penetrate the blood-brain barrier and protect cells from Aβ-induced ...toxicity. However, the effects of Aβ-targeting molecules on other cellular processes, including those that modulate synaptic plasticity, remain unknown. We report here that BTA-EG4 decreases Aβ levels, alters cell surface expression of amyloid precursor protein (APP), and improves memory in wild-type mice. Interestingly, the BTA-EG4-mediated behavioral improvement is not correlated with LTP, but with increased spinogenesis. The higher dendritic spine density reflects an increase in the number of functional synapses as determined by increased miniature EPSC (mEPSC) frequency without changes in presynaptic parameters or postsynaptic mEPSC amplitude. Additionally, BTA-EG4 requires APP to regulate dendritic spine density through a Ras signaling-dependent mechanism. Thus, BTA-EG4 may provide broad therapeutic benefits for improving neuronal and cognitive function, and may have implications in neurodegenerative disease therapy.
ABSTRACT
Measuring phase modulation in pulsating stars has proven to be a highly successful way of finding binary systems. The class of pulsating main-sequence A and F variables, known as δ Scuti ...stars consists of particularly good targets for this, and the Kepler sample of these has been almost fully exploited. However, some Keplerδ Scuti stars have incorrect temperatures in stellar properties catalogues, and were missed in previous analyses. We used an automated pulsation classification algorithm to find 93 new δ Scuti pulsators among tens of thousands of F-type stars, which we then searched for phase modulation attributable to binarity. We discovered 10 new binary systems and calculated their orbital parameters, which we compared with those of binaries previously discovered in the same way. The results suggest that some of the new companions may be white dwarfs.
Current prognostic factors are poor at identifying patients at risk of disease recurrence after surgery for stage II colon cancer. Here we describe a DNA microarray-based prognostic assay using ...clinically relevant formalin-fixed paraffin-embedded (FFPE) samples.
A gene signature was developed from a balanced set of 73 patients with recurrent disease (high risk) and 142 patients with no recurrence (low risk) within 5 years of surgery.
The 634-probe set signature identified high-risk patients with a hazard ratio (HR) of 2.62 (P < .001) during cross validation of the training set. In an independent validation set of 144 samples, the signature identified high-risk patients with an HR of 2.53 (P < .001) for recurrence and an HR of 2.21 (P = .0084) for cancer-related death. Additionally, the signature was shown to perform independently from known prognostic factors (P < .001).
This gene signature represents a novel prognostic biomarker for patients with stage II colon cancer that can be applied to FFPE tumor samples.
Methods Retrospective chart review of young children at risk for peanut allergy evaluated at Children's Hospital of Pittsburgh of UPMC with a peanut food challenge between March 1, 2015 and July 31, ...2016.
Treatment options for peanut allergy are limited. In previous clinical trials, epicutaneous immunotherapy with a patch containing 250-μg peanut protein (Viaskin Peanut 250 μg VP250) was well ...tolerated and statistically superior to placebo in desensitizing peanut-allergic children.
To examine the safety of VP250 in children, using a study design approximating potential real-world use.
REAL LIfe Use and Safety of EPIT (REALISE) is a phase 3 multicenter study consisting of a 6-month, randomized, double-blind, placebo-controlled period followed by open-label active treatment. Children aged 4 to 11 years with physician diagnosis of peanut allergy received daily treatment with placebo (6 months) or VP250 (up to 36 months). Data from the 6-month, randomized, controlled phase of REALISE are reported.
Three hundred ninety-three children were randomized 3:1 to receive VP250 (n = 294) or placebo (n = 99) for 6 months; 284 (72.3%) children had a history of peanut anaphylaxis. According to parent diary, all participants receiving VP250 and 83.8% receiving placebo reported at least 1 episode of local skin reaction, with frequency decreasing over time. Only 4 participants (1.4%) receiving VP250 discontinued because of adverse events (AEs). Epinephrine was administered for allergic reactions attributed to VP250 in 7 children (2.4%), of whom 5 remained in the study; none involved severe anaphylaxis. Overall, AE rates were similar among participants with and without a history of peanut anaphylaxis.
In a study designed to mirror real-world use, VP250 was observed to be well tolerated in peanut-allergic children, consistent with previous phase 2b and 3 studies.
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