Impostorism in American medical students during early clinical training: gender differences and intercorrelating factors.

Objectives: This study examined the incidence and severity of impostorism in third-year medical students as they transitioned from the preclinical to clinical phases of training.

Methods: A cross-sectional study was conducted in third-year medical students (N=215).  Respondents completed a voluntary, anonymous, 60-item survey that included the Clance Impostor Phenomenon Scale and the Perceived Stress Scale.

Impostorism in third-year medical students: an item analysis using the Clance impostor phenomenon scale.

Introduction: Impostorism, feelings of distrust in one's abilities and accomplishments despite evidence to the contrary, is frequent in medical students and negatively affects student wellness.

Methods: The aspects of impostorism that were most prevalent in medical students during the transition from the preclinical to clinical phases of their training were assessed using an anonymous, voluntary 60-item survey that included the Clance Impostor Phenomenon Scale (CIPS) and a 2-item burnout assessment administered in October-November 2018. Ratings of individual CIPS items were compared between items for the entire sample and in subpopulations of students.

Post-exam feedback with question rationales improves re-test performance of medical students on a multiple-choice exam.

This study compared the effects of two types of delayed feedback (correct response or correct response + rationale) provided to students by a computer-based testing system following an exam. The preclinical medical curriculum at the University of Kansas Medical Center uses a two-exam system for summative assessments in which students test, revisit material, and then re-test (same content, different questions), with the higher score used to determine the students' grades. Using a quasi-experimental design and data collected during the normal course of instruction, test and re-test scores from midterm multiple choice examinations were compared between academic year (AY) 2015-2016, which provided delayed feedback with the correct answer only, and AY 2016-2017, where delayed feedback consisted of the correct answer plus a rationale.

Regional differences in dopamine release in the R6/2 mouse caudate putamen.

Huntington's disease (HD) is a fatal neurodegenerative disorder that is characterized by degeneration of the striatum. Here, fast-scan cyclic voltammetry at carbon-fiber microelectrodes was used to uncover regional differences in dopamine (DA) release in the caudate putamen of R6/2 and wild-type control mice. We found a decreasing ventral-to-dorsal gradient in DA release, evoked by a single electrical stimulus pulse, in aged R6/2 mice.

N-3 (Omega-3) Fatty Acids: Effects on Brain Dopamine Systems and Potential Role in the Etiology and Treatment of Neuropsychiatric Disorders.

Background & Objective: A number of neuropsychiatric disorders, including Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder, and, to some extent, depression, involve dysregulation of the brain dopamine systems. The etiology of these diseases is multifactorial, involving genetic and environmental factors. Evidence suggests that inadequate levels of n-3 (omega- 3) polyunsaturated fatty acids (PUFA) in the brain may represent a risk factor for these disorders.

Lipids in psychiatric disorders and preventive medicine.

Psychiatric disorders like mood disorders, schizophrenia, or drug addiction affect a sizeable proportion of the human population and severely compromise quality of life. Therefore, measures to prevent the manifestation, and treatments to ameliorate the symptoms, of these disorders are in high demand. Brain lipids determine the localization and function of proteins in the cell membrane of neurons.

Pramipexole derivatives as potent and selective dopamine D(3) receptor agonists with improved human microsomal stability.

Herein we report the synthesis and evaluation of a series of new pramipexole derivatives as highly potent and selective agonists of the dopamine-3 (D3 ) receptor. A number of these new compounds bind to the D3 receptor with sub-nanomolar affinity and show excellent selectivity (>10,000) for the D3 receptor over the D1 and D2 receptors. For example, compound 23 (N-(cis-3-(2-(((S)-2-amino-4,5,6,7-tetrahydrobenzo[d]thiazol-6-yl)(propyl)amino)ethyl)-3-hydroxycyclobutyl)-3-(5-methyl-1,2,4-oxadiazol-3-yl)benzamide) binds to the D3 receptor with a Ki value of 0.

Differential effects of intrastriatal 6-hydroxydopamine on cell number and morphology in midbrain dopaminergic subregions of the rat.

The midbrain dopaminergic perikarya are differentially affected in Parkinson׳s disease (PD). This study compared the effects of a partial unilateral intrastriatal 6-hydroxydopamine (6-OHDA) lesion model of PD on the number, morphology, and nucleolar volume of dopaminergic cells in the substantia nigra pars compacta (SNpc), ventral tegmental area (VTA), and retrorubral field (RRF). Adult, male rats (n=10) underwent unilateral intrastriatal infusion of 6-OHDA (12.

Tranylcypromine substituted cis-hydroxycyclobutylnaphthamides as potent and selective dopamine D₃ receptor antagonists.

We report a class of potent and selective dopamine D3 receptor antagonists based upon tranylcypromine. Although tranylcypromine has a low affinity for the rat D3 receptor (K(i) = 12.8 μM), our efforts have yielded (1R,2S)-11 (CJ-1882), which has K(i) values of 2.

Streptozotocin-induced diabetes partially attenuates the effects of a high-fat diet on liver and brain fatty acid composition in mice.

The current study addresses the effects of a high-fat diet on liver and brain fatty acid compositions and the interaction of that diet with diabetes in a type 1 mouse model. Adult, male, normal and streptozotocin-induced diabetic C57BL/6 mice were fed standard (14 % kcal from fat) or high-fat (54 % kcal from fat, hydrogenated vegetable shortening and corn oil) diets for 8 weeks. Liver and whole brain total phospholipid fatty acid compositions were then determined by TLC/GC.

Low brain DHA content worsens sensorimotor outcomes after TBI and decreases TBI-induced Timp1 expression in juvenile rats.

The effects of dietary modulation of brain DHA content on outcomes after TBI were examined in a juvenile rat model. Long-Evans rats with normal or diet-induced decreases in brain DHA were subjected to a controlled cortical impact or sham surgery on postnatal day 17. Rats with the greatest decreases in brain DHA had the poorest sensorimotor outcomes after TBI.

Altered nucleolar morphology in substantia nigra dopamine neurons following 6-hydroxydopamine lesion in rats.

The nucleolus, the site of ribosomal ribonucleic acid (rRNA) transcription and assembly, is an important player in the cellular response to stress. Altered nucleolar function and morphology, including decreased nucleolar volume, has been observed in Parkinson's disease; thus the nucleolus represents a potential indicator of neurodegeneration in the disease. This study determined the effects of a partial unilateral intrastriatal 6-hydroxydopamine (6-OHDA) lesion, which models the dopaminergic loss found in Parkinson's disease, on the nucleoli of dopaminergic cells in the substantia nigra pars compacta (SNpc).

N-3 (omega-3) polyunsaturated Fatty acids in the pathophysiology and treatment of depression: pre-clinical evidence.

A growing literature suggests the association of low tissue levels and/or dietary intake of n-polyunsaturated fatty acids (PUFA) with depressive illnesses. Animal studies show that low tissue and/or dietary n-3 PUFAs can lead to behaviors and neurobiological effects associated with depression and can potentiate the consequences of stress, whereas higher levels have the opposite effect. These data support the involvement of n-3 PUFAs levels in the disease processes underlying depression.

High-affinity and selective dopamine D₃ receptor full agonists.

We have designed, synthesized and evaluated a series of new compounds with the goal to identify potent and selective D(3) ligands. The two most potent and selective new D(3) ligands are compounds 38 and 52, which bind to the D(3) receptors with a K(i) value of 10,000 times over the D(1) receptors. Both 38 and 52 are full agonists with high potency at the D(3) receptor in a D(3) functional assay.

A novel use of combined tyrosine hydroxylase and silver nucleolar staining to determine the effects of a unilateral intrastriatal 6-hydroxydopamine lesion in the substantia nigra: a stereological study.

Neurotoxic lesions of the nigrostriatal pathway model the deficits found in Parkinson's disease. This study used stereology and a novel staining method to examine the effects of a partial unilateral striatal 6-hydroxydopamine (6-OHDA) lesion on substantia nigra pars compacta (SNpc) dopamine neuron number and morphology in rats. Adult male Long-Evans rats were subjected to unilateral lesion of the SNpc by intrastriatal microinjection of 6-OHDA (12.

CJ-1639: A Potent and Highly Selective Dopamine D3 Receptor Full Agonist.

We have identified several ligands with high binding affinities to the dopamine D3 receptor and excellent selectivity over the D2 and D1 receptors. CJ-1639 (17) binds to the D3 receptor with a K(i) value of 0.50 nM and displays a selectivity of >5,000 times over D2 and D1 receptors in binding assays using dopamine receptors expressed in the native rat brain tissues.

Lipopolysaccharide induces H1 receptor expression and enhances histamine responsiveness in human coronary artery endothelial cells.

Summary Histamine is a well-recognized modulator of vascular inflammation. We have shown that histamine, acting via H1 receptors (H1R), synergizes lipopolysaccharide (LPS)-induced production of prostaglandin I(2) (PGI(2)), PGE(2) and interleukin-6 (IL-6) by endothelial cells. The synergy between histamine and LPS was partly attributed to histamine -induced expression of Toll-like receptor 4 (TLR4).

Behavioral sensitization to cocaine in rats: evidence for temporal differences in dopamine D3 and D2 receptor sensitivity.

Rationale: Cocaine-induced changes in D(2) receptors have been implicated in the expression of sensitized behavioral responses and addiction-like behaviors; however, the influence of D(3) receptors is less clear.

Objectives: To characterize the effects of repeated cocaine administration on the sensitivity of rats to D(2)- and D(3)-mediated behaviors, as well as the binding properties of ventral striatal D(2)-like and D(3) receptors.

Methods: Pramipexole was used to assess the sensitivity of rats to D(3)/D(2) agonist-induced yawning, hypothermia, and locomotor activity, 24 h, 72 h, 10, 21, and 42 days after repeated cocaine or saline administration.

Differences in methylphenidate dose response between periadolescent and adult rats in the familiar arena-novel alcove task.

Methylphenidate is a psychostimulant widely used in the treatment of attention deficit hyperactivity disorder. In this study, the effects of two nonstereotypy-inducing doses of methylphenidate (2.5 and 5.

N-3 (omega-3) Fatty acids in postpartum depression: implications for prevention and treatment.

A growing body of clinical and epidemiological evidence suggests that low dietary intake and/or tissue levels of n-3 (omega-3) polyunsaturated fatty acids (PUFAs) are associated with postpartum depression. Low tissue levels of n-3 PUFAs, particularly docosahexaenoic acid (DHA), are reported in patients with either postpartum or nonpuerperal depression. Moreover, the physiological demands of pregnancy and lactation put childbearing women at particular risk of experiencing a loss of DHA from tissues including the brain, especially in individuals with inadequate dietary n-3 PUFA intake or suboptimal metabolic capabilities.

Dopamine receptor alterations in female rats with diet-induced decreased brain docosahexaenoic acid (DHA): interactions with reproductive status.

Decreased tissue levels of n-3 (omega-3) fatty acids, particularly docosahexaenoic acid (DHA), are implicated in the etiologies of non-puerperal and postpartum depression. This study examined the effects of a diet-induced loss of brain DHA content and concurrent reproductive status on dopaminergic parameters in adult female Long-Evans rats. An alpha-linolenic acid-deficient diet and breeding protocols were used to produce virgin and parous female rats with cortical phospholipid DHA levels 20-22% lower than those fed a control diet containing adequate alpha-linolenic acid.

Developmental effects of dietary n-3 fatty acids on activity and response to novelty.

Insufficient availability of n-3 polyunsaturated fatty acids (PUFA) during pre- and neonatal development decreases accretion of docosahexaenoic acid (DHA, 22:6n-3) in the developing brain. Low tissue levels of DHA are associated with neurodevelopmental disorders including attention deficit hyperactivity disorder (ADHD). In this study, 1st- and 2nd-litter male Long-Evans rats were raised from conception on a Control diet containing alpha-linolenic acid (4.