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1.
Genetics ; 227(1)2024 05 07.
Article in English | MEDLINE | ID: mdl-38531678

ABSTRACT

Genetic screens for recessive alleles induce mutations, make the mutated chromosomes homozygous, and then assay those homozygotes for the phenotype of interest. When screening for genes required for female meiosis, the phenotype of interest has typically been nondisjunction from chromosome segregation errors. As this requires that mutant females be viable and fertile, any mutants that are lethal or sterile when homozygous cannot be recovered by this approach. To overcome these limitations, we have screened the VALIUM22 collection of RNAi constructs that target germline-expressing genes in a vector optimized for germline expression by driving RNAi with GAL4 under control of a germline-specific promoter (nanos or mat-alpha4). This allowed us to test genes that would be lethal if knocked down in all cells, and by examining unfertilized metaphase-arrested mature oocytes, we could identify defects in sterile females. After screening >1,450 lines of the collection for two different defects (chromosome congression and the hypoxic sequestration of Mps1-GFP to ooplasmic filaments), we obtained multiple hits for both phenotypes, identified novel meiotic phenotypes for genes that had been previously characterized in other processes, and identified the first phenotypes to be associated with several previously uncharacterized genes.


Subject(s)
Drosophila melanogaster , Meiosis , RNA Interference , Animals , Female , Meiosis/genetics , Drosophila melanogaster/genetics , Phenotype , Oocytes/metabolism , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Genetic Testing/methods , Male
2.
bioRxiv ; 2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38293152

ABSTRACT

Genetic screens for recessive alleles induce mutations, make the mutated chromosomes homozygous, and then assay those homozygotes for the phenotype of interest. When screening for genes required for female meiosis, the phenotype of interest has typically been nondisjunction from chromosome segregation errors. As this requires that mutant females be viable and fertile, any mutants that are lethal or sterile when homozygous cannot be recovered by this approach. To overcome these limitations, our lab has screened the VALIUM22 collection produced by the Harvard TRiP Project, which contains RNAi constructs targeting genes known to be expressed in the germline in a vector optimized for germline expression. By driving RNAi with GAL4 under control of a germline-specific promoter (nanos or mat-alpha4), we can test genes that would be lethal if knocked down in all cells, and by examining unfertilized metaphase-arrested mature oocytes, we can identify defects associated with genes whose knockdown results in sterility or causes other errors besides nondisjunction. We screened this collection to identify genes that disrupt either of two phenotypes when knocked down: the ability of meiotic chromosomes to congress to a single mass at the end of prometaphase, and the sequestration of Mps1-GFP to ooplasmic filaments in response to hypoxia. After screening >1450 lines of the collection, we obtained multiple hits for both phenotypes, identified novel meiotic phenotypes for genes that had been previously characterized in other processes, and identified the first phenotypes to be associated with several previously uncharacterized genes.

3.
Analyst ; 148(21): 5496-5506, 2023 Oct 23.
Article in English | MEDLINE | ID: mdl-37782094

ABSTRACT

A simple, rapid chemical coating and patterning method was developed and optimized for paper-based substrates for use in paper spray mass spectrometry (PS-MS). A variety of chlorosilanes were explored for coating paper substrates, and their effectiveness in forming hydrophobic surfaces was characterized via contact angle goniometry, scanning electron microscopy, and energy dispersive X-ray spectroscopy. Trichloromethylsilane was selected as the primary coating agent because of the short time required to produce a hydrophobic surface (contact angle > 130°), as well as the ease of patterning. Patterning was performed using 3D-printed masks and an oxygen/plasma cleaner. Optimal mask thickness and oxygen/plasma cleaning parameters were determined to produce channels varying from 0.5 to 2.5 mm in width. The effectiveness of the patterned substrates for PS-MS was determined via analysis of four antiretrovirals: emtricitabine, lamivudine, efavirenz, and dolutegravir. Calibration curves were made for each antiretroviral at varying channel widths, and the limits of detection and limits of quantification for each drug were determined. These results show that this patterning method results in an average 7.2-fold improvement in sensitivity and an average 190-fold improvement in limits of detection over uncoated paper substrates in a neat matrix. In a proof-of-concept experiment, calibration curves were generated for each antiretroviral in urine. A patterned paper substrate with a 2-mm channel resulted in an average 7.4-fold improvement in sensitivity and an average 18-fold improvement in limits of detection over uncoated paper substrates.


Subject(s)
HIV Infections , Oxygen , Humans , Mass Spectrometry , Hydrophobic and Hydrophilic Interactions , Microscopy, Electron, Scanning , Paper
4.
bioRxiv ; 2023 Aug 19.
Article in English | MEDLINE | ID: mdl-37645982

ABSTRACT

The size of subcellular structures must be tightly controlled to maintain normal cell function; this is especially important when cells are part of developing tissues or organs. Despite its importance, few studies have determined how the size of organelles or other structures is maintained during tissue growth, when cells are growing, dividing, and rearranging. The developing egg chamber is a powerful model in which to study the relative growth rates of subcellular structures. The egg chamber contains a cluster of sixteen germ cells, which are connected through intercellular bridges called ring canals. Ring canals are formed following incomplete cytokinesis after each of four germ cell divisions. As the egg chamber grows, the nurse cells and the ring canals that connect them increase in size. Here, we demonstrate that ring canal size scaling is related to their lineage; the largest, "first born" ring canals grow at a relatively slower rate than ring canals derived from subsequent mitotic divisions. This lineage-based scaling relationship is maintained even if directed transport is reduced, ring canal size is altered, or if the germ cells go through an additional mitotic division. Further, we propose that changes in ring canal scaling could provide a mechanism to alter egg size.

5.
PLoS One ; 18(6): e0287449, 2023.
Article in English | MEDLINE | ID: mdl-37352285

ABSTRACT

Objective measures of adherence for antiretrovirals used as pre-exposure prophylaxis (PrEP) are critical for improving preventative efficacy in both clinical trials and real-world application. Current objective adherence measures either reflect only recent behavior (eg days for plasma or urine) or cumulative behavior (eg months for dried blood spots). Here, we measured the accumulation of the antiretroviral drug maraviroc (MVC) in hair strands by infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI) to evaluate adherence behavior longitudinally at high temporal resolution. An MSI threshold for classifying daily adherence was established using clinical samples from healthy volunteers following directly observed dosing of 1 to 7 doses MVC/week. We then used the benchmarked MSI assay to classify adherence to MVC-based PrEP regimens in hair samples collected throughout the 48-week HPTN069/ACTGA5305 study. We found that only ~32% of investigated hair samples collected during the study's active dosing period showed consistent daily PrEP adherence throughout a retrospective period of 30 days, and also found that profiles of daily individual adherence from MSI hair analysis could identify when patients were and were not taking study drug. The assessment of adherence from MSI hair strand analysis was 62% lower than adherence classified using paired plasma samples, the latter of which may be influenced by white-coat adherence. These findings demonstrate the ability of MSI hair analysis to examine daily variability of adherence behavior over a longer-term measurement and offer the potential for longitudinal comparison with risk behavior to target patient-specific adherence interventions and improve outcomes.


Subject(s)
Anti-HIV Agents , HIV Infections , Pre-Exposure Prophylaxis , Humans , Maraviroc , HIV Infections/drug therapy , HIV Infections/prevention & control , Retrospective Studies , Anti-Retroviral Agents/analysis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Hair/chemistry , Medication Adherence , Pre-Exposure Prophylaxis/methods
6.
PLoS Genet ; 19(2): e1010598, 2023 02.
Article in English | MEDLINE | ID: mdl-36809339

ABSTRACT

Transposable elements (TE) are selfish genetic elements that can cause harmful mutations. In Drosophila, it has been estimated that half of all spontaneous visible marker phenotypes are mutations caused by TE insertions. Several factors likely limit the accumulation of exponentially amplifying TEs within genomes. First, synergistic interactions between TEs that amplify their harm with increasing copy number are proposed to limit TE copy number. However, the nature of this synergy is poorly understood. Second, because of the harm posed by TEs, eukaryotes have evolved systems of small RNA-based genome defense to limit transposition. However, as in all immune systems, there is a cost of autoimmunity and small RNA-based systems that silence TEs can inadvertently silence genes flanking TE insertions. In a screen for essential meiotic genes in Drosophila melanogaster, a truncated Doc retrotransposon within a neighboring gene was found to trigger the germline silencing of ald, the Drosophila Mps1 homolog, a gene essential for proper chromosome segregation in meiosis. A subsequent screen for suppressors of this silencing identified a new insertion of a Hobo DNA transposon in the same neighboring gene. Here we describe how the original Doc insertion triggers flanking piRNA biogenesis and local gene silencing. We show that this local gene silencing occurs in cis and is dependent on deadlock, a component of the Rhino-Deadlock-Cutoff (RDC) complex, to trigger dual-strand piRNA biogenesis at TE insertions. We further show how the additional Hobo insertion leads to de-silencing by reducing flanking piRNA biogenesis triggered by the original Doc insertion. These results support a model of TE-mediated gene silencing by piRNA biogenesis in cis that depends on local determinants of transcription. This may explain complex patterns of off-target gene silencing triggered by TEs within populations and in the laboratory. It also provides a mechanism of sign epistasis among TE insertions, illuminates the complex nature of their interactions and supports a model in which off-target gene silencing shapes the evolution of the RDC complex.


Subject(s)
Drosophila melanogaster , Piwi-Interacting RNA , Animals , Drosophila melanogaster/genetics , DNA Transposable Elements , RNA, Small Interfering/genetics , Drosophila/genetics , Gene Silencing
7.
Antimicrob Agents Chemother ; 66(4): e0217621, 2022 04 19.
Article in English | MEDLINE | ID: mdl-35266824

ABSTRACT

Most measures of adherence to antiretroviral therapy require a blood sample, and none capture longitudinal daily adherence. A new noninvasive method for measuring daily adherence to antiretroviral regimens containing emtricitabine (FTC) was developed for intact hair strands using infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI). A directly observed therapy study of daily and intermittent (3, 1, and 0 doses/week) FTC dosing (n = 12) benchmarked adherence in hair, revealing distinct accumulation patterns and median FTC signal abundance (1,702, 495, 352, and 0, respectively) with each dosing frequency. A threshold value of FTCsignal abundance of 500 differentiated daily dosing from 3 or fewer doses/week (specificity, 100%; sensitivity, 100% over 30 days and 80% over 60 days). Using these criteria, daily FTC hair adherence was classified in young men (n = 8) who have sex with men (YMSM) engaged in or initiating preexposure prophylaxis (PrEP). Four types of adherence profiles were observed in sequential 30-day periods: consistently high, occasional missed doses, improvement following study initiation, and intermittent. Discrete days of nonadherence were identified across the 60-day window, with the average number of consecutive days classified as nonadherent increasing across the four profile types (1, 2, 19, and 58 days, respectively). Additionally, cumulative FTC response in hair (60-day average) significantly correlated with dried blood spot tenofovir diphosphate concentrations collected simultaneously (rs = 0.79, P = 0.03). Based on these data, IR-MALDESI FTC adherence classification in hair strands can better delineate short-term changes in adherence behaviors over a long retrospective window, offering great potential for noninvasive adherence monitoring and quick supportive interventions.


Subject(s)
Anti-HIV Agents , HIV Infections , Pre-Exposure Prophylaxis , Sexual and Gender Minorities , Anti-HIV Agents/therapeutic use , Emtricitabine/therapeutic use , HIV Infections/drug therapy , HIV Infections/prevention & control , Hair/chemistry , Homosexuality, Male , Humans , Male , Mass Spectrometry , Medication Adherence , Pre-Exposure Prophylaxis/methods , Retrospective Studies , Tenofovir/therapeutic use
8.
Nurs Forum ; 57(2): 234-243, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34748227

ABSTRACT

AIM: To characterize nurses' engagement in Centers for Disease Control and Prevention promoted personal protective behaviors (PPBs) outside the work setting during the COVID-19 pandemic and factors that inform engagement in these behaviors. BACKGROUND: Nurses' health is of vital importance to the functioning of the healthcare system. Little is known as to what informs nurses' use of PPBs outside the work setting. DESIGN: Cross-sectional survey study. SETTINGS: A large healthcare system in the southeastern region of the United States. PARTICIPANTS: Nine hundred fifty eight registered nurses. METHODS: Participants surveyed during the week of September 14th. Survey contained questions regarding factors that may be linked to nurses' compliance with PPBs. RESULTS: The most frequently reported behavior practiced outside work was "cover mouth with cough or sneeze." Concern for COVID-19 infection and confidence in masks to control the spread of COVID-19 were positively related to both frequency and number of protective behaviors engaged in (p < .01), while fatigue was inversely related to engagement with PPBs (p = .01). There was some evidence that viewing self as role model may predict behavior. CONCLUSIONS: Personal factors drive engagement with protective behaviors outside the work setting. Implications for nursing management and education are explored.


Subject(s)
COVID-19 , Nurses , COVID-19/prevention & control , Cross-Sectional Studies , Humans , Pandemics/prevention & control , SARS-CoV-2 , Surveys and Questionnaires
9.
Analyst ; 145(13): 4540-4550, 2020 Jul 07.
Article in English | MEDLINE | ID: mdl-32420552

ABSTRACT

Analysis of drugs in hair by mass spectrometry imaging (MSI) has great potential as an objective, long-term measure of medication adherence. However, the fidelity of the chemical record in hair may be compromised by any cosmetic hair treatments. Here, we investigate infrared matrix-assisted laser desorption electrospray ionization (IR-MALDESI) MSI response to multiple antiretrovirals (ARVs) in cosmetically treated hair. Hair strands from patients on different ARV regimens were mechanically treated with dye, bleach, and relaxer. The treatments had little or no effect relative to untreated controls for cobicistat, abacavir, dolutegravir, maraviroc, efavirenz, and darunavir, but all three treatments removed emtricitabine (FTC) to undetectable levels from patient hair strands. We also evaluated hair strands by IR-MALDESI MSI from 8 patients on FTC-based regimens who reported a range of hair treatments at varying recency prior to hair collection. While FTC was undetectable in the treated portion of these hair strands, ARVs coadministered with FTC remained detectable in hair strands after treatment. We conclude that IR-MALDESI MSI can be used when measuring adherence to ARV therapy, provided that ARVs other than FTC are targeted in people using hair treatments.


Subject(s)
Antiviral Agents/analysis , Hair Analysis/methods , Hair/chemistry , Antiviral Agents/chemistry , Hair Bleaching Agents/chemistry , Hair Dyes/chemistry , Humans , Spectrometry, Mass, Electrospray Ionization/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods
10.
G3 (Bethesda) ; 10(5): 1765-1774, 2020 05 04.
Article in English | MEDLINE | ID: mdl-32217631

ABSTRACT

The physical connections established by recombination are normally sufficient to ensure proper chromosome segregation during female Meiosis I. However, nonexchange chromosomes (such as the Muller F element or "dot" chromosome in D. melanogaster) can still segregate accurately because they remain connected by heterochromatic tethers. A recent study examined female meiosis in the closely related species D. melanogaster and D. simulans, and found a nearly twofold difference in the mean distance the obligately nonexchange dot chromosomes were separated during Prometaphase. That study proposed two speculative hypotheses for this difference, the first being the amount of heterochromatin in each species, and the second being the species' differing tolerance for common inversions in natural populations. We tested these hypotheses by examining female meiosis in 12 additional Drosophila species. While neither hypothesis had significant support, we did see 10-fold variation in dot chromosome sizes, and fivefold variation in the frequency of chromosomes out on the spindle, which were both significantly correlated with chromosome separation distances. In addition to demonstrating that heterochromatin abundance changes chromosome behavior, this implies that the duration of Prometaphase chromosome movements must be proportional to the size of the F element in these species. Additionally, we examined D. willistoni, a species that lacks a free dot chromosome. We observed that chromosomes still moved out on the meiotic spindle, and the F element was always positioned closest to the spindle poles. This result is consistent with models where one role of the dot chromosomes is to help organize the meiotic spindle.


Subject(s)
Drosophila melanogaster , Drosophila , Animals , Chromosome Segregation , Drosophila/genetics , Female , Meiosis/genetics , Spindle Apparatus
11.
Adv Health Sci Educ Theory Pract ; 25(3): 691-709, 2020 08.
Article in English | MEDLINE | ID: mdl-32052236

ABSTRACT

There has been increased attention to and emphasis on competency-based medical education and the transformation from highly supervised medical students towards independent, entrustable physicians. We explored how program directors (PDs) justify decisions about whether they would trust finishing Post Graduate Year 1 (PGY1) residents to care for the PD or a loved one. Using an end of year survey with validity evidence, we assessed PDs' responses (Yes, No, Not Sure) and written comments about this entrustment decision for USUHS medical students from graduating classes of 2013-2015 (PGY1). We performed a qualitative inductive content analysis to identify themes in how PDs justified their decisions as well as descriptive statistics and a contingency table analysis to examine associations between trust decisions and election to membership in Alpha Omega Alpha (AOA), or conversely, referral to the Student Promotions Committee (SPC) for remediation. Qualitative analyses revealed five themes related to this trust decision about medical residents: personal, interpersonal, knowledge, competence, and developmental. Neither AOA status, nor SPC referral status was significantly associated with the trust measure, overall, but positive trust decisions were significantly higher among those elected to AOA than in those who were not. Positive trust decisions were significantly associated with AOA status but negative trust decisions were not significantly associated with referral to the SPC. This study offers insights into what attributes may underpin trust decisions by PDs. Our findings suggest that PDs' frequent use of personal and interpersonal characteristics to justify trust decisions contrasts with the use of clinical and knowledge based assessments during undergraduate medical education (UME), and emphasize the importance of critical intrinsic abilities.


Subject(s)
Faculty, Medical , Family , Internship and Residency , Students, Medical , Trust , Humans , Multivariate Analysis , Social Learning , Surveys and Questionnaires
12.
BMC Med Educ ; 19(1): 260, 2019 Jul 12.
Article in English | MEDLINE | ID: mdl-31299948

ABSTRACT

BACKGROUND: In 2010, coincident with the 100th anniversary of Flexner's sentinel report, the Carnegie Foundation published an updated review of North American medical education and challenged medical schools to initiate further educational reforms. Specific recommendations pertained to a) ensuring standardized outcomes while allowing for individualized processes, b) integrating foundational knowledge with clinical experience, c) cultivating habits of inquiry and innovation and d) professional identity formation. As we approach the 10-year anniversary of this latest report, we sought to determine what type of curricular revisions have been emerging within the past decade and what types of challenges have been encountered along the way? METHODS: In 2018, an electronic survey was sent to all 166 Liaison Committee on Medical Education (LCME) accredited North American Medical Schools, using the points of contact (educational deans) that were listed in a publicly available, Association of American Medical Colleges database. Free text comments were grouped into themes using the constant-comparative technique. RESULTS: Sixty unique responses yielding a 36.14% response rate. The distribution of responses was proportionally representative of the distribution of public vs. private, old vs. new vs. established North American medical schools. Self-reported curricular changes aggregated into five main themes: Changes in curricular structure/organization, changes in curricular content, changes in curricular delivery, changes in assessment, and changes involving increased use of technology/informatics. Challenges were predominantly focused on overcoming faculty resistance, faculty development, securing adequate resourcing, change management, and competition for limited amounts of curricular time. CONCLUSIONS: Changes in curricular organization, content, delivery, assessment and the use of technology reflect reforms that are broad and deep. Empowering faculty to "let go" of familiar constructs/processes requires strong leadership, particularly when initiating particularly disruptive curricular changes, such as relocating the Step 1 examination or shifting to a competency-based curriculum. While North American medical schools are responding to the calls for action described in the second (2010) Carnegie Foundation report, the full vision has yet to be achieved.


Subject(s)
Clinical Competence , Curriculum , Education, Medical, Undergraduate/organization & administration , Schools, Medical/organization & administration , Female , Forecasting , Humans , Male , Organizational Innovation , Students, Medical/statistics & numerical data , Surveys and Questionnaires , United States
13.
Anal Chem ; 91(16): 10816-10822, 2019 08 20.
Article in English | MEDLINE | ID: mdl-31345022

ABSTRACT

Here, we assess infrared matrix assisted laser desorption electrospray ionization (IR-MALDESI) mass spectrometry imaging (MSI) analysis of hair as a clinical tool for monitoring patient adherence to the antiretroviral maraviroc (MVC). A custom MATLAB-based algorithm has been developed to streamline data analysis and generate longitudinal profiles of drug incorporation along the length of hair strands. Hair strands from volunteers enrolled in a directly observed therapy study were analyzed by IR-MALDESI MSI and processed using this tool to characterize the profiles of single doses and a daily dose regimen of MVC. Single dose responses were 1.7 [1.1, 2.5] mm (median [range]) wide along the length of the hair and were detected in 8 out of 12 volunteers. Daily dose profiles capturing 28 days of continuous dosing were approximately 5 times the intensity of single dose profiles and 10.5 [7.0, 13] mm wide, corresponding to 1 month of hair growth. MVC ion abundance was observed in all 12 volunteers for the daily dosing period. Daily dosing profiles were consistent with a model of MVC accumulation in hair based on linear superposition of a single dose response, indicating the potential for prediction of daily drug-taking behavior based on deconvolution of a complex longitudinal profile in hair.


Subject(s)
Anti-Retroviral Agents/analysis , Hair/chemistry , Medication Adherence , Healthy Volunteers , Humans , Infrared Rays , Spectrometry, Mass, Electrospray Ionization
14.
Xenobiotica ; 49(10): 1192-1201, 2019 Oct.
Article in English | MEDLINE | ID: mdl-30346892

ABSTRACT

1. Antiretroviral concentrations in cerebrospinal fluid (CSF) are used as surrogate for brain tissue, although sparse data support this. We quantified antiretrovirals in brain tissue across preclinical models, compared them to CSF, and calculated 90% inhibitory quotients (IQ90) for nonhuman primate (NHP) brain tissue. Spatial distribution of efavirenz was performed by mass-spectrometry imaging (MSI). 2. HIV or RT-SHIV-infected and uninfected animals from two humanized mouse models (hemopoietic-stem cell/RAG2-, n = 36; bone marrow-liver-thymus/BLT, n =13) and an NHP model (rhesus macaque, n =18) were dosed with six antiretrovirals. Brain tissue, CSF (NHPs), and plasma were collected at necropsy. Drug concentrations were measured by LC-MS/MS. Rapid equilibrium dialysis determined protein binding in NHP brain. 3. Brain tissue penetration of most antiretrovirals were >10-fold lower (p < 0.02) in humanized mice than NHPs. NHP CSF concentrations were >13-fold lower (p <0.02) than brain tissue with poor agreement except for efavirenz (r = 0.91, p = 0.001). Despite 97% brain tissue protein binding, efavirenz achieved IQ90>1 in all animals and 2-fold greater white versus gray matter concentration. 4. Brain tissue penetration varied across animal models for all antiretrovirals except raltegravir, and extrapolating brain tissue concentrations between models should be avoided. With the exception of efavirenz, CSF is not a surrogate for brain tissue concentrations.


Subject(s)
Anti-HIV Agents , Benzoxazines , Brain , HIV Infections , HIV-1 , Alkynes , Animals , Anti-HIV Agents/pharmacokinetics , Anti-HIV Agents/pharmacology , Benzoxazines/pharmacokinetics , Benzoxazines/pharmacology , Brain/metabolism , Brain/pathology , Brain/virology , Cyclopropanes , Drug Evaluation, Preclinical , Female , HIV Infections/cerebrospinal fluid , HIV Infections/drug therapy , HIV Infections/pathology , Humans , Macaca mulatta , Male , Mice
15.
Mil Med ; 183(suppl_3): 225-232, 2018 11 01.
Article in English | MEDLINE | ID: mdl-30462339

ABSTRACT

To improve health care, the USA needs to create a longitudinal medical education system that will develop physicians able to lead the transformation of health care toward a focus on the promotion of healthy behaviors aimed at preventing disease. The development of patient-centered care has been an important step in promoting healthy behaviors. However, to truly develop a meaningful relationship with a patient, a physician must first see them as a person, not as a list of diseases. Medical education should develop physicians able to provide person-centered care - moving beyond patient-centered care to focus more broadly on the entirety of the person, for whom being a patient is merely one aspect of their personhood. Restructuring medical education begins with the admission process itself, followed by longitudinal changes at the undergraduate, graduate, and continuing professional development levels that will reinforce the attributes critical for future physicians. The authors view this longitudinal approach through the theoretical framework of situated cognition, exploring personal, environmental, and social factors leading to success; outline several key stages of medical education from matriculation through continuing professional development; and identify potential areas that merit longitudinal efforts to develop future physicians able to promote positive health behaviors.


Subject(s)
Education, Medical/standards , Physicians/standards , Education, Medical/methods , Education, Medical, Continuing/methods , Education, Medical, Continuing/standards , Health Care Costs/standards , Health Care Costs/trends , Humans , Patient-Centered Care/standards , Patient-Centered Care/trends , Physicians/psychology , Quality of Health Care/standards , United States
16.
Anal Chem ; 90(21): 13000-13006, 2018 11 06.
Article in English | MEDLINE | ID: mdl-30335366

ABSTRACT

Improvements were made to a previously developed platform coupling microchip capillary electrophoresis (CE) with high pressure mass spectrometry (HPMS). The RF drive frequency was increased to over 30 MHz from less than 10 MHz, and the ion trap was scaled down to 100 µm critical dimensions. A stretched length ion trap was used to improve sensitivity, and a tube lens was used to improve ion transmission. Detection of the 20 common amino acids was demonstrated, resulting in an average improvement of signal-to-noise of 28 times and an average improvement in peak width of 2.6 times over those obtained in previous work. Consumption of amino acids by cells in growth media was monitored over time using the improved CE-HPMS platform, and several amino acids were shown to be consumed at different rates, demonstrating the potential for real-time bioreactor monitoring.


Subject(s)
Electrophoresis, Microchip/instrumentation , Escherichia coli K12/growth & development , Lab-On-A-Chip Devices , Amino Acids/analysis , Electrophoresis, Capillary/methods , Electrophoresis, Microchip/methods , Spectrometry, Mass, Electrospray Ionization/methods
18.
Clin Immunol ; 195: 119-126, 2018 10.
Article in English | MEDLINE | ID: mdl-29842946

ABSTRACT

The development of rheumatoid factor (RF) and/or anti-citrullinated protein antibodies (ACPAs) can be observed years prior to clinical diagnosis of rheumatoid arthritis (RA). Nevertheless, the interaction between these two autoantibodies and their combined effect on development of RA is unclear. We measured RF, cytokines, and ACPA subtypes in serial pre-clinical serum samples collected from 83 US veterans who all developed RA. Levels of cytokines and ACPAs were compared between the following groups: anti-cyclic citrullinated peptide (anti-CCP)-/RF- (double negative), anti-CCP+/RF-, anti-CCP-/RF+, or anti-CCP+/RF+ (double-positive). The double-positive subgroup had significantly higher levels of 20 inflammatory cytokines and 29 ACPA reactivities, and the shortest interval, 1.3 years, between the preclinical sample timepoint and diagnosis of RA. Thus, the combined presence of ACPAs and RF is associated with a more rapid progression to RA, suggesting that anti-CCP+/RF+ individuals have a more advanced preclinical disease state and that the onset of RA may be imminent.


Subject(s)
Anti-Citrullinated Protein Antibodies/blood , Arthritis, Rheumatoid/diagnosis , Inflammation Mediators/blood , Rheumatoid Factor/blood , Adult , Arthritis, Rheumatoid/immunology , Cohort Studies , Cytokines/blood , Disease Progression , Epitopes, B-Lymphocyte/immunology , Female , Humans , Male , Middle Aged , United States , Veterans
19.
Mil Med ; 183(11-12): e680-e684, 2018 11 01.
Article in English | MEDLINE | ID: mdl-29718290

ABSTRACT

Introduction: This is an empirical study to better understand commonly used medical school admission measures and disenrollment decisions during undergraduate medical education as well as graduate medical education (GME) probation or termination decisions. Materials and Methods: Based on the data of USUHS medical students matriculating between 1998 and 2011 (N = 2,460), we compared medical school graduates and those disenrolled from medical school on MCAT scores, undergraduate BCPM (Biology, Chemistry, Physics, Math) GPA, and undergraduate overall GPA. We also reported more specific reasons for disenrollment decisions. Next, we compared the students who were referred to the student promotion committee (SPC) with other students on these measures. Moving onto GME, we compared trainees who were put on probation or terminated from training with those who were not on MCAT and undergraduate GPA measures. In addition, we examined the association between being referred to the SPC and GME probation or termination. Results: There were 2,347 graduates and 113 disenrolled students from medical school (4.8%). For the disenrolled students, 43 (38.7%) students were disenrolled for exclusively (or primarily) non-academic reasons, and 68 (61.3%) were disenrolled for exclusively (or primarily) academic reasons. The t-tests showed statistically significant differences on the MCAT score of the first attempt (t(2,449) = 7.22, P < 0.01, Cohen's d = 0.70), average MCAT score (t(2,449) = 4.22, P < 0.01, Cohen's d = 0.41), and highest MCAT score (t(2,449) = 3.51, P < 0.01, Cohen's d = 0.34). Logistic regression model selection also revealed that the best predictor for disenrollment was the first MCAT score (exp(b) = 0.83, 95% CI = (0.78, 0.88)). No significant differences on these measures were found from the group comparisons on SPC and GME probation or termination. There was no significant association between SPC appearance and GME probation or termination. Conclusions: Academic difficulties, especially in the basic sciences, appear to be the most common factor for disenrollment from medical school. These students also had lower MCAT scores, particularly on the first attempt. The MCAT performance indicators and undergraduate GPA were consistently lower, but not statistically significant, for those who appeared before SPC or were put on probation or terminated from training during GME.


Subject(s)
Education, Medical, Graduate/methods , Education, Medical, Undergraduate/methods , Personnel Selection/methods , Students, Medical/statistics & numerical data , Adult , Cohort Studies , College Admission Test/statistics & numerical data , Education, Medical, Graduate/statistics & numerical data , Education, Medical, Undergraduate/statistics & numerical data , Educational Measurement/methods , Educational Measurement/statistics & numerical data , Female , Humans , Logistic Models , Longitudinal Studies , Male , Personnel Selection/statistics & numerical data , School Admission Criteria/statistics & numerical data , Schools, Medical/organization & administration , Schools, Medical/statistics & numerical data
20.
Chem Commun (Camb) ; 54(2): 204-207, 2017 Dec 21.
Article in English | MEDLINE | ID: mdl-29230440

ABSTRACT

Herein we describe a synthetically simple strategy for increasing the lifetime of unstructured peptides in cytosolic environment via dimerization at the N-terminus to block threading into the catalytic cleft of cytosolic proteases. We establish this approach with kinase substrates, allowing for phosphorylation in cells as a demonstration of protease resistance.


Subject(s)
Cytosol/enzymology , Peptide Hydrolases/metabolism , Peptides/pharmacology , Protease Inhibitors/pharmacology , Cell Line , Dimerization , HeLa Cells , Humans , Molecular Structure , Peptides/chemical synthesis , Peptides/chemistry , Protease Inhibitors/chemistry
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