From goal to outcome: Analyzing the progression of biomedical sciences PhD careers in a longitudinal study using an expanded taxonomy

Biomedical sciences PhDs pursue a wide range of careers inside and outside academia. However, there is little data regarding how career interests of PhD students relate to the decision to pursue postdoctoral training or to their eventual career outcomes. Here, we present the career goals and career outcomes of 1452 biomedical sciences PhDs who graduated from Vanderbilt University between 1997 and 2021. We categorized careers using an expanded three-tiered taxonomy and flags that delineate key career milestones. We also analyzed career goal changes between matriculation and doctoral defense, and the reasons why students became more- or less-interested in research-intensive faculty careers. We linked students' career goal at doctoral defense to whether they did a postdoc, the duration of time between doctoral defense and the first non-training position, the career area of the first non-training position, and the career area of the job at 10 years after graduation. Finally, we followed individual careers for 10 years after graduation to characterize movement between different career areas over time. We found that most students changed their career goal during graduate school, declining numbers of alumni pursued postdoctoral training, many alumni entered first non-training positions in a different career area than their goal at doctoral defense, and the career area of the first non-training position was a good indicator of the job that alumni held 10 years after graduation. Our findings emphasize that students need a wide range of career development opportunities and career mentoring during graduate school to prepare them for futures in research and research-related professions.

A cross-institutional analysis of the effects of broadening trainee professional development on research productivity

PhD-trained scientists are essential contributors to the workforce in diverse employment sectors that include academia, industry, government, and nonprofit organizations. Hence, best practices for training the future biomedical workforce are of national concern. Complementing coursework and laboratory research training, many institutions now offer professional training that enables career exploration and develops a broad set of skills critical to various career paths. The National Institutes of Health (NIH) funded academic institutions to design innovative programming to enable this professional development through a mechanism known as Broadening Experiences in Scientific Training (BEST). Programming at the NIH BEST awardee institutions included career panels, skill-building workshops, job search workshops, site visits, and internships. Because doctoral training is lengthy and requires focused attention on dissertation research, an initial concern was that students participating in additional complementary training activities might exhibit an increased time to degree or diminished research productivity. Metrics were analyzed from 10 NIH BEST awardee institutions to address this concern, using time to degree and publication records as measures of efficiency and productivity. Comparing doctoral students who participated to those who did not, results revealed that across these diverse academic institutions, there were no differences in time to degree or manuscript output. Our findings support the policy that doctoral students should participate in career and professional development opportunities that are intended to prepare them for a variety of diverse and important careers in the workforce.

Institutional Training Opportunities for PhD Students in Laboratory Medicine: An Unmet Career Development Need?

In the United States, the credentialing of PhD-scientists as medical directors of clinical laboratories is driven by formal postdoctoral training programs. Prior to acceptance in one these accredited fellowships, however, a trainee's exposure to the field can be far less standardized, with significant ramifications for their awareness and competitiveness. In the current article, we describe our recent experiences in developing local, institution-based immersion opportunities for PhD experiences in the subdisciplines of laboratory medicine (clinical microbiology, clinical chemistry, and molecular genetics/genomics). It is our hope that this article-and a corresponding online survey-can prompt reflection and discussion on the status of early career training opportunities in these key clinical areas.

Applying inter-rater reliability to improve consistency in classifying PhD career outcomes

Background: There has been a groundswell of national support for transparent tracking and dissemination of PhD career outcomes. In 2017, individuals from multiple institutions and professional organizations met to create the Unified Career Outcomes Taxonomy (UCOT 2017), a three-tiered taxonomy to help institutions uniformly classify career outcomes of PhD graduates. Early adopters of UCOT 2017, noted ambiguity in some categories of the career taxonomy, raising questions about its consistent application within and across institutions. Methods: To test and evaluate the consistency of UCOT 2017, we calculated inter-rater reliability across two rounds of iterative refinement of the career taxonomy, classifying over 800 PhD alumni records via nine coders. Results: We identified areas of discordance in the taxonomy, and progressively refined UCOT 2017 and an accompanying Guidance Document to improve inter-rater reliability across all three tiers of the career taxonomy. However, differing interpretations of the classifications, especially for faculty classifications in the third tier, resulted in continued discordance among the coders. We addressed this discordance with clarifying language in the Guidance Document, and proposed the addition of a flag system for identification of the title, rank, and prefix of faculty members. This labeling system provides the additional benefit of highlighting the granularity and the intersectionality of faculty job functions, while maintaining the ability to sort by - and report data on - faculty and postdoctoral trainee roles, as is required by some national and federal reporting guidelines. We provide specific crosswalk guidance for how a user may choose to incorporate our suggestions while maintaining the ability to report in accordance with UCOT 2017. Conclusions: Our findings underscore the importance of detailed guidance documents, coder training, and periodic collaborative review of career outcomes taxonomies as PhD careers evolve in the global workforce. Implications for coder-training and use of novice coders are also discussed.

Applying inter-rater reliability to improve consistency in classifying PhD career outcomes

Background: There has been a groundswell of national support for transparent tracking and dissemination of PhD career outcomes. In 2017, individuals from multiple institutions and professional organizations met to create the Unified Career Outcomes Taxonomy (UCOT 2017), a three-tiered taxonomy to help institutions uniformly classify career outcomes of PhD graduates. Early adopters of UCOT 2017, noted ambiguity in some categories of the career taxonomy, raising questions about its consistent application within and across institutions. Methods: To test and evaluate the consistency of UCOT 2017, we calculated inter-rater reliability across two rounds of iterative refinement of the career taxonomy, classifying over 800 PhD alumni records via nine coders. Results: We identified areas of discordance in the taxonomy, and progressively refined UCOT 2017 and an accompanying Guidance Document to improve inter-rater reliability across all three tiers of the career taxonomy. However, differing interpretations of the classifications, especially for faculty classifications in the third tier, resulted in continued discordance among the coders. We addressed this discordance with clarifying language in the Guidance Document, and proposed the addition of a flag system for identification of the title, rank, and prefix of faculty members. This labeling system provides the additional benefit of highlighting the granularity and the intersectionality of faculty job functions, while maintaining the ability to sort by - and report data on - faculty and postdoctoral trainee roles, as is required by some national and federal reporting guidelines. We provide specific crosswalk guidance for how a user may choose to incorporate our suggestions while maintaining the ability to report in accordance with UCOT 2017. Conclusions: Our findings underscore the importance of detailed guidance documents, coder training, and periodic collaborative review of career outcomes taxonomies as PhD careers evolve in the global workforce. Implications for coder-training and use of novice coders are also discussed.

The Limitations of the GRE in Predicting Success in Biomedical Graduate School

Historically, admissions committees for biomedical Ph.D. programs have heavily weighed GRE scores when considering applications for admission. The predictive validity of GRE scores on graduate student success is unclear, and there have been no recent investigations specifically on the relationship between general GRE scores and graduate student success in biomedical research. Data from Vanderbilt University Medical School's biomedical umbrella program were used to test to what extent GRE scores can predict outcomes in graduate school training when controlling for other admissions information. Overall, the GRE did not prove useful in predicating who will graduate with a Ph.D., pass the qualifying exam, have a shorter time to defense, deliver more conference presentations, publish more first author papers, or obtain an individual grant or fellowship. GRE scores were found to be moderate predictors of first semester grades, and weak to moderate predictors of graduate GPA and some elements of a faculty evaluation. These findings suggest admissions committees of biomedical doctoral programs should consider minimizing their reliance on GRE scores to predict the important measures of progress in the program and student productivity.

Providing Experiential Business and Management Training for Biomedical Research Trainees

Many biomedical PhD trainees lack exposure to business principles, which limits their competitiveness and effectiveness in academic and industry careers. To fill this training gap, we developed Business and Management Principles for Scientists, a semester-long program that combined didactic exposure to business fundamentals with practical team-based projects aimed at solving real business problems encountered by institutional shared--resource core facilities. The program also included a retreat featuring presentations by and networking with local life science entrepreneurs and final team presentations to expert judges. Quantitative and qualitative metrics were used to evaluate the program's impact on trainees. A pretest-posttest approach was used to assess trainees' baseline knowledge and mastery of module concepts, and each individual's pretest and posttest responses were compared. The mean score improved by more than 17 percentage points. Trainees also took an online survey to provide feedback about the module. Nearly all participants agreed or strongly agreed that the module was a valuable use of their time and will help guide their career decisions and that project work helped drive home module concepts. More than 75% of trainees reported discussing the module with their research advisors, and all of these participants reported supportive or neutral responses. Collectively, the trainee feedback about the module, improvement in test scores, and trainee perception of advisor support suggest that this short module is an effective method of providing scientists with efficient and meaningful exposure to business concepts.

Neurotensin activates GABAergic interneurons in the prefrontal cortex

Converging data suggest a dysfunction of prefrontal cortical GABAergic interneurons in schizophrenia. Morphological and physiological studies indicate that cortical GABA cells are modulated by a variety of afferents. The peptide transmitter neurotensin may be one such modulator of interneurons. In the rat prefrontal cortex (PFC), neurotensin is exclusively localized to dopamine axons and has been suggested to be decreased in schizophrenia. However, the effects of neurotensin on cortical interneurons are poorly understood. We used in vivo microdialysis in freely moving rats to assess whether neurotensin regulates PFC GABAergic interneurons. Intra-PFC administration of neurotensin concentration-dependently increased extracellular GABA levels; this effect was impulse dependent, being blocked by treatment with tetrodotoxin. The ability of neurotensin to increase GABA levels in the PFC was also blocked by pretreatment with 2-[1-(7-chloro-4-quinolinyl)-5-(2,6-dimethoxyphenyl)pyrazole-3-yl)carbonylamino]tricyclo(3.3.1.1 [EC] .3.7)decan-2-carboxylic acid (SR48692), a high-affinity neurotensin receptor 1 (NTR1) antagonist. This finding is consistent with our observation that NTR1 was localized to GABAergic interneurons in the PFC, particularly parvalbumin-containing interneurons. Because neurotensin is exclusively localized to dopamine axons in the PFC, we also determined whether neurotensin plays a role in the ability of dopamine agonists to increase extracellular GABA levels. We found that D2 agonist-elicited increases in PFC GABA levels were blocked by pretreatment with SR48692, consistent with data indicating that D2 autoreceptor agonists increase neurotensin release from dopamine-neurotensin axons in the PFC. These findings suggest that neurotensin plays an important role in regulating prefrontal cortical interneurons and that it may be useful to consider neurotensin agonists as an adjunct in the treatment of schizophrenia.

The neurotensin agonist PD149163 increases Fos expression in the prefrontal cortex of the rat

Dopaminergic axons innervating the prefrontal cortex (PFC) target both pyramidal cells and GABAergic interneurons. Many of these dopamine (DA) axons in the rat coexpress the peptide neurotransmitter neurotensin. Previous electrophysiological data have suggested that neurotensin activates GABAergic interneurons in the PFC. Activation of D2-like DA receptors increases extracellular GABA levels in the PFC, as opposed to the striatum, where D2 receptor activation inhibits GABAergic neurons. Because activation of presynaptic D2 release-modulating autoreceptors in the PFC suppresses DA release but increases release of the cotransmitter neurotensin, D2 agonists may enhance the activity of GABAergic interneurons via release of neurotensin. In order to determine if neurotensin can activate GABAergic interneurons, we treated rats with the peptide neurotensin agonist, PD149163, and examined Fos expression in PFC neurons. Systemic administration of PD149163 increased overall Fos expression in the PFC, but not in the dorsal striatum. PD149163 induced Fos in PFC interneurons, as defined by the presence of calcium-binding proteins, and in pyramidal cells. Pretreatment with the high-affinity neurotensin antagonist, SR48692, blocked neurotensin agonist-induced Fos expression. These data suggest that neurotensin activates interneurons in the PFC of the rat.

Drug use during pregnancy and lactation

This article reviews the basic principles of pharmacology and teratogenicity of drugs for the pregnant and lactating woman and summarizes the Food and Drug Administration, American College of Obstetrics and Gynecology, and American Academy of Pediatrics classifications. These categories were devised for caregivers of both women and their babies. The authors propose a two/three letter category system to assist those who, like family physicians, must care for women while pregnant and while lactating. Common problems from everyday practice are reviewed, with an emphasis on the important drugs to use and avoid in a wide variety of everyday clinical settings to help the busy primary care physician in making decisions about medications in pregnancy and lactation.

Alternative medicine in maternity care

Primary care physicians are confronted daily with questions from their patients about alternative medicine. When maternity care patients seek information about such therapies, careful attention must be paid to issues of safety and efficacy for both the mother and her unborn child. This article clarifies the role of alternative medicine in maternity care by looking at the definitions and history of common alternative therapies, documenting the evidence for alternative therapies in prenatal, intrapartum, and postpartum care, and suggesting ways to incorporate alternative medicine into primary care practice.

Role of P-450 arachidonic acid epoxygenase in the response of cerebral blood flow to glutamate in rats

BACKGROUND AND PURPOSE

Glutamate, a major excitatory neurotransmitter in the brain, has been implicated in the hyperemic response to increases in the activity of neurons, but the mechanism of glutamate-induced dilation of cerebral blood vessels is unknown. Glutamate has been shown to enhance the release of arachidonic acid (AA) in brain tissue and cultured astrocytes. We have previously shown that astrocytes metabolize AA to vasodilator products, epoxyeicostrienoic acids (EETs), and express a P-450 AA epoxygenase, P-450 2C11. We tested the hypothesis that glutamate-induced dilation of cerebral arterioles is mediated in part by changes in the formation and release of EETs by perivascular astrocytes.

METHODS

Primary astrocyte cultures were prepared from 3-day-old rat pups. The cells were labeled with [14C]AA, and the effect of glutamate on the formation of EETs from [14C]AA by cultured astrocytes was studied. The expression of P-450 2C11 protein in the microsomal fractions of cultured astrocytes was assessed by Western blot. In vivo cerebral blood flow measurements were made in adult rats by laser-Doppler flowmetry after administration of glutamate into the subdural space of the rat before and after treatment with miconazole.

RESULTS

Glutamate treatment (100 mumol/L for 30 minutes) induced a threefold increase in the formation of EETs from [14C]AA by cultured astrocytes, and the increase was inhibited by miconazole (20 mumol/L), an inhibitor of P-450 AA epoxygenase. Treatment with glutamate (100 mumol/L) for 12 hours increased the expression of P-450 2C11 protein in the microsomal fraction of cultured astrocytes. The response of laser-Doppler cerebral blood flow to administration of glutamate (500 mumol/L) into the subdural space of the rat was significantly attenuated after treatment with miconazole (20 mumol/L for 30 minutes).

CONCLUSIONS

These findings suggest a role for a P-450 AA epoxygenase in astrocytes in the coupling between the metabolic activity of neurons and regional blood flow in the brain.

Mechanisms by which lipoprotein lipase alters cellular metabolism of lipoprotein(a), low density lipoprotein, and nascent lipoproteins. Roles for low density lipoprotein receptors and heparan sulfate proteoglycans

We sought to investigate effects of lipoprotein lipase (LpL) on cellular catabolism of lipoproteins rich in apolipoprotein B-100. LpL increased cellular degradation of lipoprotein(a) (Lp(a)) and low density lipoprotein (LDL) by 277% +/- 3.8% and 32.5% +/- 4.1%, respectively, and cell association by 509% +/- 8.7% and 83.9% +/- 4.0%. The enhanced degradation was entirely lysosomal. Enhanced degradation of Lp(a) had at least two components, one LDL receptor-dependent and unaffected by heparitinase digestion of the cells, and the other LDL receptor-independent and heparitinase-sensitive. The effect of LpL on LDL degradation was entirely LDL receptor-independent, heparitinase-sensitive, and essentially absent from mutant Chinese hamster ovary cells that lack cell surface heparan sulfate proteoglycans. Enhanced cell association of Lp(a) and LDL was largely LDL receptor-independent and heparitinase-sensitive. The ability of LpL to reduce net secretion of apolipoprotein B-100 by HepG2 cells by enhancing cellular reuptake of nascent lipoproteins was also LDL receptor-independent and heparitinase-sensitive. None of these effects on Lp(a), LDL, or nascent lipoproteins required LpL enzymatic activity. We conclude that LpL promotes binding of apolipoprotein B-100-rich lipoproteins to cell surface heparan sulfate proteoglycans. LpL also enhanced the otherwise weak binding of Lp(a) to LDL receptors. The heparan sulfate proteoglycan pathway represents a novel catabolic mechanism that may allow substantial cellular and interstitial accumulation of cholesteryl ester-rich lipoproteins, independent of feedback inhibition by cellular sterol content.

Lipoprotein lipase modulates net secretory output of apolipoprotein B in vitro. A possible pathophysiologic explanation for familial combined hyperlipidemia

We showed previously that net secretory output of apolipoprotein B (apo B) from cultured human hepatoma cells (HepG2) is regulated by rapid reuptake of nascent lipoproteins before they have diffused away from the vicinity of the cells. We now sought to determine if the nascent lipoproteins could be remodeled to enhance or impede reuptake. We found that lipoprotein lipase (LpL), an enzyme that hydrolyzes lipoprotein triglyceride, reduced HepG2 output of apo B to one-quarter to one-half of control. The reduction was apparent during co-incubations as short as 2 h and as long as 24 h. Heparin, which blocks receptor-mediated binding of lipoproteins, abolished the effect of LpL on apo B output, without causing enzyme inhibition. To assess uptake directly, we prepared labeled nascent lipoproteins. LpL tripled the cellular uptake of labeled nascent lipoproteins, from 15.2% +/- 0.7% to 48.7% +/- 0.3% of the total applied to the cells. Cellular uptake of 125I-labeled anti-LDL receptor IgG was unaffected by LpL; thus, LpL enhanced reuptake by altering lipoproteins, not receptors. Because LpL is present in the space of Disse in the liver, we conclude that LpL may act on newly secreted lipoproteins to enhance reuptake in vivo. LpL deficiency would reduce local reuptake of apo B, which would appear as overproduction, thereby providing a mechanistic link between partial LpL deficiency and familial combined hyperlipidemia.