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Inequalities and injustices are thorny issues in liberal societies, manifesting in forms such as the gender–pay gap; sentencing discrepancies among Black, Hispanic, and White defendants; and unequal medical-resource distribution across ethnicities. One cause of these inequalities is implicit social bias —unconsciously formed associations between social groups and attributions such as "nurturing," "lazy," or "uneducated." One strategy to counteract implicit and explicit human biases is delegating crucial decisions, such as how to allocate benefits, resources, or opportunities, to algorithms. Algorithms, however, are not necessarily impartial and objective. Although they can detect and mitigate human biases, they can also perpetuate and even amplify existing inequalities and injustices. We explore how a philosophical thought experiment, Rawls's "veil of ignorance," and a psychological phenomenon, deliberate ignorance, can help shield individuals, institutions, and algorithms from biases. We discuss the benefits and drawbacks of methods for shielding human and artificial decision makers from potentially biasing information. We then broaden our discussion beyond the issues of bias and fairness and turn to a research agenda aimed at improving human judgment accuracy with the assistance of algorithms that conceal information that has the potential to undermine performance. Finally, we propose interdisciplinary research questions. [ABSTRACT FROM AUTHOR]

Introduction: Primary hydatid cyst of the spinal cord is exceedingly rare. Diagnosis at the early stages is difficult as they may be asymptomatic or have mild vague pain. Patients typically present when there are features of cord/root compression. Magnetic resonance imaging (MRI) stands as the primary investigative modality, but even then, preoperative diagnosis might not always be possible as it may resemble other pathological conditions. Methods: This was a case report of a single case with evidence-based discussion. Informed consent was obtained. Case Report: We present a 62-year-old female patient with progressive paraparesis and numbness of bilateral lower limbs. MRI was suggestive of a tubercular pleurospinal lesion at the D9-D10 level. However, intraoperatively, it was identified to be a rare case of primary pleurospinal (thoracic) hydatid cyst. The patient was managed with complete surgical removal of all the cysts and antihelminthic drug therapy with no evidence of recurrence at the 2-year follow-up. Conclusion: Radiological diagnosis might not be accurate and hydatidosis must be kept in mind to avoid intraoperative confusion. Timely diagnosis, appropriate surgical planning, and comprehensive follow-up are crucial for achieving optimal outcomes. [ABSTRACT FROM AUTHOR]

Objective: Our study examined the impact of sex, ADHD subtype, and comorbid illnesses (depression/anxiety) on the timing of diagnosis and treatment for ADHD. Method: To analyze ADHD patients, four health databases were used to assess subtype, comorbid mood, and antidepressant or anxiolytic drug exposure. Analyses were stratified by sex and age. Standardized mean differences measured intergroup differences. Results: Females with ADHD were identified at older ages and had higher rates of depression and anxiety diagnoses and treatments before and after their initial ADHD diagnosis. Predominantly inattentive ADHD patients were diagnosed later and more likely to receive mood disorder diagnosis and treatment than hyperactive impulsive ADHD patients. Conclusions: Results suggest a more complex ADHD presentation in females, potentially causing late diagnosis and delayed treatment. [ABSTRACT FROM AUTHOR]

Study Design: : Retrospective Chart Review. Objectives: Incidental durotomies (IDs) are common spine surgery complications. In this study, we present a review on the most commonly utilized management strategies, report our institutional experience with case examples, and describe a stepwise management algorithm. Methods: A retrospective review was performed of the electronic medical records of all patients who underwent a thoracolumbar or lumbar spine surgery between March 2017 and September 2019. Additionally, a literature review of the current management approaches to treat IDs and persistent postoperative CSF leaks following lumbar spine surgeries was performed. Results: We looked at 1133 patients that underwent posterior thoracolumbar spine surgery. There was intraoperative evidence of ID in 116 cases. Based on our cohort and the current literature, we developed a progressive treatment algorithm for IDs that begins with a primary repair, which can be bolstered by dural sealants or a muscle patch. If this fails, the primary repair can be followed by a paraspinal muscle flap, as well as a lumbar drain. If the patient cannot be weaned from temporary CSF diversion, the final step in controlling postoperative leak is longterm CSF diversion via a lumboperitoneal shunt. In our experience, these shunts can be weaned once the patient has no further clinical or radiographic signs of CSF leak. Conclusions: There is no standardized management approach of IDs and CSF leaks in the literature. This article intends to provide a progressive treatment algorithm and contribute to the development process of a treatment consensus. [ABSTRACT FROM AUTHOR]

Background: Prescription-type opioid use disorder (POUD) is often accompanied by comorbid anxiety, yet the impact of anxiety on retention in opioid agonist therapy (OAT) is unclear. Therefore, this study investigated whether baseline anxiety severity affects retention in OAT and whether this effect differs by OAT type (methadone maintenance therapy (MMT) vs. buprenorphine/naloxone (BNX)). Methods: This secondary analysis used data from a pan-Canadian randomized trial comparing flexible take-home dosing BNX and standard supervised MMT for 24 weeks. The study included 268 adults with POUD. Baseline anxiety was assessed using the Beck Anxiety Inventory (BAI), with BAI ≥ 16 indicating moderate-to-severe anxiety. The primary outcomes were retention in assigned and any OAT at week 24. In addition, the impact of anxiety severity on retention was examined, and assigned OAT was considered an effect modifier. Results: Of the participants, 176 (65%) reported moderate-to-severe baseline anxiety. In adjusted analyses, there was no significant difference in retention between those with BAI ≥ 16 and those with BAI < 16 assigned (29% vs. 28%; odds ratio (OR) = 2.03, 95% confidence interval (CI) = 0.94–4.40; P = 0.07) or any OAT (35% vs. 34%; OR = 1.57, 95% CI = 0.77–3.21; P = 0.21). In addition, there was no significant effect modification by OAT type for retention in assigned (P = 0.41) or any OAT (P = 0.71). In adjusted analyses, greater retention in treatment was associated with BNX (vs. MMT), male gender identity (vs. female, transgender, or other), enrolment in the Quebec study site (vs. other sites), and absence of a positive urine drug screen for stimulants at baseline. Conclusions: Baseline anxiety severity did not significantly impact retention in OAT for adults with POUD, and there was no significant effect modification by OAT type. However, the overall retention rates were low, highlighting the need to develop new strategies to minimize the risk of attrition from treatment. Clinical Trial Registration: This study was registered in ClinicalTrials.gov (NCT03033732). [ABSTRACT FROM AUTHOR]

Background: Generalized convulsive status epilepticus (GCSE) is one of the most challenging life-threatening neurological emergencies. If GCSE becomes super-refractory, it is associated with significant mortality. Although aggressive management of prolonged status epilepticus was conducted, the mortality has not decreased since the late 1990s. Objectives: The present study aimed to explore the risk factors for progression to super-refractory in patients with generalized convulsive status epilepticus (GCSE). Moreover, we illustrated the risk factors for mortality in GCSE patients. Design: An observational retrospective cohort study. Methods: We conducted a retrospective study of patients with GCSE admitted to our neurocritical unit, in Guangzhou, China, from October 2010 to February 2021. The data of sociodemographic information, etiology, laboratory results, treatment, and prognosis were collected and analyzed. Results: A total of 106 patients were enrolled; 51 (48%) of them developed super-refractory status epilepticus (SRSE). Multivariate logistic regression analysis demonstrated that patients with autoimmune encephalitis (p = 0.015) and intracranial infection (p = 0.019) are likely to progress to SRSE. The in-hospital mortality was 11.8% and 9.1% for patients in the SRSE and non-SRSE groups, respectively (p = 0.652). Multivariate logistic regression analysis showed that neutrophil-to-lymphocyte ratios (NLR) at admission were independently associated with in-hospital mortality. Up to 31.4% of SRSE patients and 29.1% of non-SRSE patients died within 6 months after discharge (p = 0.798). Multivariate logistic regression analysis showed that plasma exchange (PE) was a protective factor for 6-month mortality. A high NLR at discharge was a risk factor for 6-month mortality. Conclusion: In the current study, about 48% of GCSE patients progressed to SRSE. Regarding etiology, autoimmune encephalitis or intracranial infection was prone to SRSE. No significant differences were observed in the in-hospital and 6-month mortality between SRSE and non-SRSE groups. Multivariate logistic regression analysis showed that NLR at admission and discharge was an independent predictor of in-hospital and 6-month mortality, respectively. Moreover, PE significantly reduced the 6-month mortality. [ABSTRACT FROM AUTHOR]

Machine learning (ML) models, especially deep neural networks, are increasingly being used for the analysis of medical images and as a supporting tool for clinical decision-making. In this study, we propose an artificial intelligence system to facilitate dental decision-making for the removal of mandibular third molars (M3M) based on 2-dimensional orthopantograms and the risk assessment of such a procedure. A total of 4,516 panoramic radiographic images collected at the Center of Dental Medicine at the University of Zurich, Switzerland, were used for training the ML model. After image preparation and preprocessing, a spatially dependent U-Net was employed to detect and retrieve the region of the M3M and inferior alveolar nerve (IAN). Image patches identified to contain a M3M were automatically processed by a deep neural network for the classification of M3M superimposition over the IAN (task 1) and M3M root development (task 2). A control evaluation set of 120 images, collected from a different data source than the training data and labeled by 5 dental practitioners, was leveraged to reliably evaluate model performance. By 10-fold cross-validation, we achieved accuracy values of 0.94 and 0.93 for the M3M–IAN superimposition task and the M3M root development task, respectively, and accuracies of 0.9 and 0.87 when evaluated on the control data set, using a ResNet-101 trained in a semisupervised fashion. Matthew's correlation coefficient values of 0.82 and 0.75 for task 1 and task 2, evaluated on the control data set, indicate robust generalization of our model. Depending on the different label combinations of task 1 and task 2, we propose a diagnostic table that suggests whether additional imaging via 3-dimensional cone beam tomography is advisable. Ultimately, computer-aided decision-making tools benefit clinical practice by enabling efficient and risk-reduced decision-making and by supporting less experienced practitioners before the surgical removal of the M3M. [ABSTRACT FROM AUTHOR]

Background: Post-hemorrhoidectomy bleeding is a serious complication after hemorrhoidectomy. In the setting of a new wave of anticoagulants, we aimed to investigate the relationship of post-operative anticoagulation timing and delayed bleeding. Methods: We performed a retrospective analysis of all patients undergoing hemorrhoidectomy at a single institution over a 10-year period. Fisher's exact and Wilcoxon Rank Sum tests were utilized to test for association between delayed bleeding and anticoagulation use. Results: Between January 2011 and October 2020, 1469 hemorrhoidectomies were performed. A total of 216 (14.7%) were taking platelet inhibitors and 56 (3.8%) other anticoagulants. Delayed bleeding occurred in 5.2% (n = 76) of which 47% (n = 36) required operative intervention. Mean time to bleeding was 8.7 days (SD ±5.9). Time to bleeding was longer in those taking antiplatelet inhibitors vs. non-platelet inhibitors vs. none (11 vs. 8 vs. 7 days, P =.05). Among anticoagulants (n = 56), novel oral anticoagulants were more common than warfarin (57% vs 43%) and had a nonsignificant increase in delayed bleeding (31% vs 16%, P =.21). Later restart (>3 days) of novel anticoagulants after surgery was associated with increased bleeding (10.5% vs 61.5%, P=.005). On multivariable analysis, only anticoagulation use (OR 4.5, 95% CI: 2.1–10.0), male sex (OR 1.8, 95% CI: 1.1–2.9), and operative oversewing (OR 3.5, 95% CI: 1.8–6.9) were associated with delayed bleeding. Conclusion: Post-hemorrhoidectomy bleeding is more likely to occur with patients on anticoagulation. Later restart times within the first week after surgery was not associated with a decrease in bleeding. [ABSTRACT FROM AUTHOR]

Study Design: Simulation study. Objective: Pelvic incidence (PI) should be considered during surgical planning. The ideal patient position with both hip centers perfectly aligned for a lateral radiograph is rarely obtained. It has been suggested that a radiograph with axial and coronal rotation up to 20° is acceptable to obtain a measured PI within 6 degrees of the actual PI. We seek to: (1) evaluate the effect of variations in PI and patient malpositioning on measured vs true PI, and (2) determine whether the presence of one hip center within the bony acetabular rim of the contralateral hip can serve as a simple clinical decision rule on the accuracy of measured PI. Methods: Published anthropometric three-dimensional pelvic landmark coordinates were used in this study. Radiographic projections were generated using linear algebra for combinations of axial and coronal rotation from −20° to +20°. True and measured PIs were compared. Results: Rotation to 20° cannot be uniformly accepted as decision rule. Pelvises with higher PIs are more sensitive to malpositioning with greater PI deviation with smaller amounts of rotation. Diagnostic performance of the hip center rule demonstrated a sensitivity of 25.58% and a specificity of 100.00%. Conclusions: Rather than assessing the quality of radiographs for PI measurement by magnitude of malpositioning, we recommend clinicians use the "hip center rule." As long as at least one hip center is contained within the bony acetabular rim of the contralateral hip, there is high confidence that measured PI will be within 6° of true PI. [ABSTRACT FROM AUTHOR]

Purpose: The present study aimed to evaluate the implementation of a civic engagement curriculum (HEART Club) designed to catalyze positive environmental change in rural communities. Design: The HEART Club curriculum was integrated into a six-month community-based health behavior intervention to reduce cardiovascular disease risk. Setting: Participants were recruited from eight rural towns in Montana and New York. Subjects: 101 midlife and older women. Intervention: Participants worked to address an issue related to their local food or physical activity environment and establish progress monitoring benchmarks. Method: Evaluation components included after-class surveys, program leader interviews (n = 15), participant focus groups (n = 8), and post-intervention surveys. Results: Intervention sites reported high fidelity (78%) to the curriculum. Average attendance was 69% and program classes were rated as highly effective (4.1 out of 5). Despite positive participant feedback, low readiness for civic engagement and insufficient time were implementation challenges. The majority of HEART Club groups had accomplished two or more benchmarks post-intervention. Facilitators of progress included community support, effective leadership, and collective effort. Participants also indicated that trying to affect community change while simultaneously making personal health improvements likely stalled initial progress. Conclusion: These findings highlight the potential and challenges associated with civic engagement within the context of rural lifestyle interventions. Future implementation efforts should focus on reframing civic engagement as an approach to support and maintain behavior change. [ABSTRACT FROM AUTHOR]

In humans, allopregnanolone plays important roles in a number of different neurodegenerative disorders, and it has been proposed for use in some therapies. Horses are commonly used as animal models for human neurodegenerative diseases, mental and behavioral disorders, and neuropsychiatric disorders, and there is interest in using hair as a biological sample to study hormones in these conditions. We validated the use of a commercial ELISA kit (DetectX allopregnanolone kit; Arbor Assays), which was designed for serum, plasma, feces, urine, and tissue samples, to assess allopregnanolone in hair samples from 30 humans and 63 horses. The ELISA kit had good precision (intra- and inter-assay CVs: 6.4% and 11.0% for equine hair; 7.3% and 11.0% for human hair, respectively), sensitivity (50.4 pg/mL for both equine and human hair), and accuracy (parallelism and recovery tests) in determining allopregnanolone concentrations in hair from both species. The allopregnanolone concentrations in human hair were 7.3–79.1 pg/mg; the concentrations were 286 ± 141 pg/mg (x̄ ± SD) in mares on the day of parturition and 16.9 ± 5.5 pg/mg in nonpregnant mares. The DetectX ELISA kit offered a simple and accessible analysis of allopregnanolone in human and equine hair samples. [ABSTRACT FROM AUTHOR]

Less than one-quarter of oral health trials are registered in a public registry. However, no study has assessed the extent of study publication and selective outcome reporting bias in the field of oral health. We identified oral health trials registered between 2006 and 2016 in ClinicalTrials.gov. We assessed whether results of early discontinued trials, trials having an unknown status, and completed trials had been published and, among published trials, whether outcomes differed between the registered record and the corresponding publication. We included 1,399 trials, of which 81 (5.8%) were discontinued, 247 (17.7%) had an unknown status, and 1,071 (76.6%) were completed. The registration was prospective for 719 (51.9%) trials. Over half the registered trials were unpublished (n = 793, 56.7%). To explore the association between trials publication and characteristics of trials, we performed a multivariate logistic regression analysis. Trials conducted in the United States (P = 0.003) or Brazil (P < 0.001) were associated with increased odds of publication, whereas trials registered prospectively (P = 0.001) and industry-sponsored trials (P = 0.02) were associated with decreased odds. Among the 479 published trials with completed status, the primary outcomes of 215 (44.9%) articles differed from that registered. Major discrepancies consisted of the introduction of a new primary outcome in the published article (196 [91.2%]) and the transformation of a registered secondary outcome into a primary outcome (112 [52.1%]). In the remaining 264 (55.1%) trials, primary outcomes did not differ from that registered, but 141 (53.4%) had been registered retrospectively. Our study highlights the high rate of nonpublication and selective outcome reporting in the field of oral health. These results could alert sponsors, funders, authors of systematic reviews, and the oral health research community at large to combat the nondisclosure of trial results. [ABSTRACT FROM AUTHOR]

Background: Generalized convulsive status epilepticus (GCSE) is one of the most challenging life-threatening neurological emergencies. If GCSE becomes super-refractory, it is associated with significant mortality. Although aggressive management of prolonged status epilepticus was conducted, the mortality has not decreased since the late 1990s. Objectives: The present study aimed to explore the risk factors for progression to superrefractory in patients with generalized convulsive status epilepticus (GCSE). Moreover, we illustrated the risk factors for mortality in GCSE patients. Design: An observational retrospective cohort study. Methods: We conducted a retrospective study of patients with GCSE admitted to our neurocritical unit, in Guangzhou, China, from October 2010 to February 2021. The data of sociodemographic information, etiology, laboratory results, treatment, and prognosis were collected and analyzed. Results: A total of 106 patients were enrolled; 51 (48%) of them developed super-refractory status epilepticus (SRSE). Multivariate logistic regression analysis demonstrated that patients with autoimmune encephalitis (p = 0.015) and intracranial infection (p = 0.019) are likely to progress to SRSE. The in-hospital mortality was 11.8% and 9.1% for patients in the SRSE and non-SRSE groups, respectively (p = 0.652). Multivariate logistic regression analysis showed that neutrophil-to-lymphocyte ratios (NLR) at admission were independently associated with in-hospital mortality. Up to 31.4% of SRSE patients and 29.1% of non-SRSE patients died within 6 months after discharge (p = 0.798). Multivariate logistic regression analysis showed that plasma exchange (PE) was a protective factor for 6-month mortality. A high NLR at discharge was a risk factor for 6-month mortality. Conclusion: In the current study, about 48% of GCSE patients progressed to SRSE. Regarding etiology, autoimmune encephalitis or intracranial infection was prone to SRSE. No significant differences were observed in the in-hospital and 6-month mortality between SRSE and non- SRSE groups. Multivariate logistic regression analysis showed that NLR at admission and discharge was an independent predictor of in-hospital and 6-month mortality, respectively. Moreover, PE significantly reduced the 6-month mortality. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective cohort. Objective: Reoperation to lumbar spinal fusion creates significant burden on patient quality of life and healthcare costs. We assessed rates, etiologies, and risk factors for reoperation following elective 1 to 2 level lumbar fusion. Methods: Patients undergoing elective 1 to 2 level lumbar fusion were identified using the Health Care Utilization Project (HCUP) state inpatient databases from Florida and California. Patients were tracked for 5 years for any subsequent lumbar fusion. Cox proportional hazard analyses for reoperation were assessed using the following covariates: fusion approach type, age, race, Charlson comormidity index, gender, and length of stay. Distribution of etiologies for reoperation was then assessed. Results: 71, 456 patients receiving elective 1 to 2 level lumbar fusion were included. A 5-year reoperation rate of 13.53% and mortality rate of 2.22% was seen. Combined anterior-posterior approaches (HR = 0.904, p < 0.05) and TLIF (HR = 0.867, p < 0.001) were associated with reduced risk of reoperation compared to stand-alone anterior approaches and non-TLIF posterior approaches. Age, gender, and number of comorbidities were not associated with risk of reoperation. From 1 to 5 years, degenerative disease rose from 43.50% to 50.31% of reoperations; mechanical failure decreased from 37.65% to 29.77%. Conclusions: TLIF and combined anterior-posterior approaches for 1 to 2 level lumbar fusion are associated with the lowest rate of reoperation. Number of comorbidities and age are not predictive of reoperation. Primary etiologies leading to reoperation were degenerative disease and mechanical failure. Mortality rate is not increased from baseline following 1 to 2 level lumbar fusion. [ABSTRACT FROM AUTHOR]

Objective: To determine whether glibenclamide, a non-selective adenosine 5′-triphosphate-sensitive K+ (KATP) channel blocker, attenuates pituitary adenylate cyclase-activating polypeptide-38 (PACAP38)-induced headache and vascular changes in healthy volunteers. Methods: In a double-blind, randomized, placebo controlled and crossover design, 22 healthy volunteers were assigned to receive an intravenous infusion of 10 picomole/kg/min pituitary adenylate cyclase-activating polypeptide-38 over 20 minutes followed by oral administration of 10 mg glibenclamide or placebo. The primary endpoint was the difference in incidence of headache (0–12 hours) between glibenclamide and placebo. The secondary endpoints were a difference in area under the curve for headache intensity scores, middle cerebral artery velocity (VmeanMCA), superficial temporal artery diameter, radial artery diameter, heart rate, mean arterial blood pressure and facial skin blood flow between the two study days. Results: Twenty participants completed the study. We found no difference in the incidence of pituitary adenylate cyclase-activating polypeptide-38-induced headache after glibenclamide (19/20, 95%) compared to placebo (18/20, 90%) (P = 0.698). The area under the curve for headache intensity, middle cerebral artery velocity, superficial temporal artery diameter, radial artery diameter, facial skin blood flow, heart rate and mean arterial blood pressure did not differ between pituitary adenylate cyclase-activating polypeptide-38-glibenclamide day compared to pituitary adenylate cyclase-activating polypeptide-38-placebo day (P > 0.05). Conclusions: Posttreatment with 5′-triphosphate-sensitive K+ channel inhibitor glibenclamide did not attenuate pituitary adenylate cyclase-activating polypeptide-38-induced headache and hemodynamic changes in healthy volunteers. We suggest that pituitary adenylate cyclase-activating polypeptide-38-triggered signaling pathway could be mediated by specific isoforms of sulfonylurea receptor subunits of 5′-triphosphate-sensitive K+ channels and other types of potassium channels. [ABSTRACT FROM AUTHOR]

Objective: To systematically review clinical studies investigating the involvement of adenosine and its receptors in migraine pathophysiology. Background: Adenosine is a purinergic signaling molecule, clinically used in cardiac imaging during stress tests. Headache is a frequent adverse event after intravenous adenosine administration. Migraine headache relief is reported after intake of adenosine receptor antagonist, caffeine. These findings suggest a possible involvement of adenosine signaling in migraine pathophysiology and its potential as a drug target. Methods: A search through PubMed and EMBASE was undertaken for clinical studies investigating the role of adenosine and its receptors in migraine, published until September 2021. Results: A total of 2510 studies were screened by title and abstract. Of these, seven clinical studies were included. The main findings were that adenosine infusion induced headache, and plasma adenosine levels were elevated during ictal compared to interictal periods in migraine patients. Conclusion: The present systematic review emphasizes a potentially important role of adenosine signaling in migraine pathogenesis. Further randomized and placebo-controlled clinical investigations applying adenosine receptors modulators in migraine patients are needed to further understand the adenosine involvement in migraine. [ABSTRACT FROM AUTHOR]

Increased phosphorylation of decidual insulin-like growth factor–binding protein-1 (IGFBP-1) can contribute to intrauterine growth restriction (IUGR) by decreasing the bioavailability of insulin-like growth factor-1 (IGF-1). However, the molecular mechanisms regulating IGFBP-1 phosphorylation at the maternal–fetal interface are poorly understood. Protein kinase A (PKA) is required for normal decidualization. Consensus sequences for PKA are present in IGFBP-1. We hypothesized that the expression/interaction of PKA with decidual IGFBP-1 is increased in IUGR. Parallel reaction monitoring-mass spectrometry (PRM-MS) identified multiple PKA peptides (n =>30) co-immunoprecipitating with IGFBP-1 in decidualized primary human endometrial stromal cells (HESC). PRM-MS also detected active PKApThr197 and greater site-specific IGFBP-1 phosphorylation(pSer119), (pSer98+pSer101) (pSer169+pSer174) in response to hypoxia. Hypoxia promoted colocalization [dual immunofluorescence (IF)] of PKA with IGFBP-1 in decidualized HESC. Colocalization (IF) and interaction (proximity ligation assay) of PKA and IGFBP-1 were increased in decidua collected from placenta of human IUGR pregnancies (n =8) compared with decidua from pregnancies with normal fetal growth. Similar changes were detected in decidual PKA/IGFBP-1 using placenta from baboons subjected to maternal nutrient reduction (MNR) vs controls (n =3 each). In baboons, these effects were evident in MNR at gestational day 120 prior to IUGR onset. Increased PKA-mediated phosphorylation of decidual IGFBP-1 may contribute to decreased IGF-1 bioavailability in the maternal–fetal interface in IUGR. [ABSTRACT FROM AUTHOR]

Objective: Medicine is considered one if not the most stressful educational field. Thus, the aim of this study is to investigate the prevalence of stress and poor sleeping quality among medical students and the association between them. Method: This cross-sectional study was conducted at the University of Jordan on second- and third-year medical students. The questionnaire consisted of: 1) Demographics; 2) The assessment tools which were Pittsburgh Quality of Sleep Index (PSQI) and Kessler Psychological Distress Status (K10). Binary logistic regression, chi-square and linear regression were used to investigate the association between PSQI, K10, and their determinants. Results: The mean for PSQI score was 6.76 ± 3.32. PSQI scores interpretation revealed that 61.7% of the 282 participants of this study were poor sleepers. Logistic regression results showed that only the category of not napping at all from the napping hours variable was significantly associated with sleeping quality. Furthermore, the mean of K10 scores was 24.5 ± 8.5. K10 scores revealed that 66.3% of the participants were stressed. Logistic regression results showed that gender and regular exercise were significantly associated with psychological distress. Additionally, chi-square test, logistic regression and linear regression showed that PSQI was significantly associated with K10 (P <0.01). Conclusions: Stress and poor sleeping quality in medical students at the University of Jordan were highly prevalent and strongly associated. What determined PSQI was daytime napping, and for K10 were regular exercise and gender. Further investigations into stress and sleep quality in the Arabian region are needed. [ABSTRACT FROM AUTHOR]

Chinese policy has turned to the globalisation of communication and stories. Beyond the diplomatic 'voice', one of the ways that Chinese culture is reaching out to the rest of the world is through science fiction. Sci-fi can be construed as a specialist thinking-circuit for cultures to build and explore experimental models of collective action at global and planetary scale. What do its stories tell us about the globalisation of Chinese culture? When the need to 'save the world' has crossed over from sci-fi to science, from entertainment to activism, and from a thought experiment to imminent danger, humans as a whole face challenges of their own making: climate change, environmental pollution, pandemics, extinctions, exclusions and nuclear annihilation. Can sci-fi inspire collective action at species scale? What role will globalising China play? [ABSTRACT FROM AUTHOR]

Background: Ketamine is rapidly metabolized to norketamine and hydroxynorketamine (HNK) metabolites. In female mice, when compared to males, higher levels of (2R,6R;2S,6S)-HNK have been observed following ketamine treatment, and higher levels of (2R,6R)-HNK following the direct administration of (2R,6R)-HNK. Aim: The objective of this study was to evaluate the impact of sex in humans and mice, and gonadal hormones in mice on the metabolism of ketamine to form norketamine and HNKs and in the metabolism/elimination of (2R,6R)-HNK. Methods: In CD-1 mice, we utilized gonadectomy to evaluate the role of circulating gonadal hormones in mediating sex-dependent differences in ketamine and (2R,6R)-HNK metabolism. In humans (34 with treatment-resistant depression and 23 healthy controls) receiving an antidepressant dose of ketamine (0.5 mg/kg i.v. infusion over 40 min), we evaluated plasma levels of ketamine, norketamine, and HNKs. Results: In humans, plasma levels of ketamine and norketamine were higher in males than females, while (2R,6R;2S,6S)-HNK levels were not different. Following ketamine administration to mice (10 mg/kg i.p.), Cmax and total plasma concentrations of ketamine and norketamine were higher, and those of (2R,6R;2S,6S)-HNK were lower, in intact males compared to females. Direct (2R,6R)-HNK administration (10 mg/kg i.p.) resulted in higher levels of (2R,6R)-HNK in female mice. Ovariectomy did not alter ketamine metabolism in female mice, whereas orchidectomy recapitulated female pharmacokinetic differences in male mice, which was reversed with testosterone replacement. Conclusion: Sex is an important biological variable that influences the metabolism of ketamine and the HNKs, which may contribute to sex differences in therapeutic antidepressant efficacy or side effects. [ABSTRACT FROM AUTHOR]

Introduction: We aimed to determine the ratios of the lower and upper lip landmarks in the sagittal and vertical direction for maxillary osteotomies and mandibular lengthening surgeries, in a prospective way. Methods: This prospective cohort study is the second part of the OSRES (Orthognathic/orthofacial Surgery RESearch group); patients that underwent mandibular and/or Le Fort I surgery without genioplasty were included. Pearson correlation determined significant patient and surgical variables. The relationship between hard and soft tissue changes was determined by correlation analysis. Results: An average ratio of 103% was found for sB:B for mandibular advancement surgery without genioplasty and 83% for sB:Pg with genioplasty. Lower jaw surgery yielded a ratio of 68% for Li:Ili in the horizontal direction and 69% with a genioplasty. Displacement of the upper jaw gave a ratio of 83% for Ls:Iui anteriorly for all surgery groups combined. Horizontal displacement of the upper jaw yielded a strong correlation with a ratio of 88% for sA:A. Conclusions: The equations presented in this study for landmark sB, sA, labrale inferius, and labrale superius can aid preoperative planning of lip position. No accurate way was found to predict stomion inferius and stomion superius. Highlights: We prospectively arranged for computerized measurements of sB:B, Li:Ili, Ls: Iui, Stoi:Ili, Stos: Iui, and sA:A ratios on lateral cephalograms using FaceWizz. The influences of direction and the type of surgery were studied. Moderate to strong correlations were found for horizontal ratios of sB:B, Li:Lli, Ls:Iui, and sA:A. Weak correlations were found for vertical movement of Stos:Iui and Stoi:Ili. [ABSTRACT FROM AUTHOR]

Objective/Aim: We describe best practices for modeling egocentric networks and health outcomes using a five-step guide. Background: Social network analysis (SNA) is common in social science fields and has more recently been used to study health-related topics including obesity, violence, substance use, health organizational behavior, and healthcare utilization. SNA, alone or in conjunction with spatial analysis, can be used to uniquely evaluate the impact of the physical or built environment on health. The environment can shape the presence, quality, and function of social relationships with spatial and network processes interacting to affect health outcomes. While there are some common measures frequently used in modeling the impact of social networks on health outcomes, there is no standard approach to social network modeling in health research, which impacts rigor and reproducibility. Methods: We provide an overview of social network concepts and terminology focused on egocentric network data. Egocentric, or personal networks, take the perspective of an individual who identifies their own connections (alters) and also the relationships between alters. Results: We describe best practices for modeling egocentric networks and health outcomes according to the following five-step guide: (1) model selection, (2) social network exposure variable and selection considerations, (3) covariate selection related to sociodemographic and health characteristics, (4) covariate selection related to social network characteristics, and (5) analytic considerations. We also present an example of SNA. Conclusions: SNA provides a powerful repertoire of techniques to examine how relationships impact attitudes, experiences, and behaviors—and subsequently health. [ABSTRACT FROM AUTHOR]

BACKGROUND: As medicine and the delivery of healthcare enters the age of Artificial Intelligence (AI), the need for competent human–machine interaction to aid clinical decisions will rise. Medical students need to be sufficiently proficient in AI, its advantages to improve healthcare's expenses, quality, and access. Similarly, students must be educated about the shortfalls of AI such as bias, transparency, and liability. Overlooking a technology that will be transformative for the foreseeable future would place medical students at a disadvantage. However, there has been little interest in researching a proper method to implement AI in the medical education curriculum. This study aims to review the current literature that covers the attitudes of medical students towards AI, implementation of AI in the medical curriculum, and describe the need for more research in this area. METHODS: An integrative review was performed to combine data from various research designs and literature. Pubmed, Medline (Ovid), GoogleScholar, and Web of Science articles between 2010 and 2020 were all searched with particular inclusion and exclusion criteria. Full text of the selected articles was analyzed using the Extension of Technology Acceptance Model and the Diffusions of Innovations theory. Data were successively pooled together, recorded, and analyzed quantitatively using a modified Hawkings evaluation form. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses was utilized to help improve reporting. RESULTS: A total of 39 articles meeting inclusion criteria were identified. Primary assessments of medical students attitudes were identified (n = 5). Plans to implement AI in the curriculum for the purpose of teaching students about AI (n = 6) and articles reporting actual implemented changes (n = 2) were assessed. Finally, 26 articles described the need for more research on this topic or calling for the need of change in medical curriculum to anticipate AI in healthcare. CONCLUSIONS: There are few plans or implementations reported on how to incorporate AI in the medical curriculum. Medical schools must work together to create a longitudinal study and initiative on how to successfully equip medical students with knowledge in AI. [ABSTRACT FROM AUTHOR]

Oral melanoma (OM) is a highly aggressive tumor of the oral cavity in humans and dogs. Here we review the phenotypic similarities between the disease in these 2 species as the basis for the view that canine OM is a good model for the corresponding human disease. Utility of the "canine model" has likely been hindered by a paucity of information about the extent of the molecular genetic similarities between human and canine OMs. Current knowledge of the somatic alterations that underpin human tumorigenesis and metastatic progression is relatively limited, primarily due to the rarity of the disease in humans and consequent lack of opportunity for large-scale molecular analysis. The molecular genetic comparisons between human and canine OMs that have been completed indicate some overlap between the somatic mutation profiles of canine OMs and a subset of human OMs. However, further comparative studies featuring, in particular, larger numbers of human OMs are required to provide substantive evidence that canine OMs share mechanisms of tumorigenesis with at least a subset of human OMs. Future molecular genetic investigations of both human and canine OMs should investigate how primary tumors develop a metastatic gene expression signature and the genetic and epigenetic alterations specific to metastatic sites. Such studies may identify genetic alterations and pathways specific to the metastatic disease which could be targetable by new drugs. [ABSTRACT FROM AUTHOR]

Alterations in the concentration of nitric oxide (NO) and L-arginine metabolites have been associated with the pathophysiology of different vascular diseases. Here, we describe striking changes in L-arginine metabolism after hemorrhagic stroke. Blood and cerebrospinal fluid (CSF) samples of patients with intracerebral hemorrhage (ICH) and/or intraventricular hemorrhage were collected over a ten-day period. Liquid chromatography-tandem mass spectrometry was used to quantify key substrates and products of L-arginine metabolizing enzymes as well as asymmetric (ADMA) and symmetric dimethylarginine (SDMA). Changes in the plasma were limited to early reductions in L-ornithine, L-lysine, and L-citrulline concentrations. Intrathecally, we observed signs of early NO synthase (NOS) upregulation followed by a decrease back to baseline accompanied by a rise in the level of its endogenous NOS-inhibitor ADMA. SDMA demonstrated increased levels throughout the observation period. For arginase, a pattern of persistently elevated activity was measured and arginine:glycine amidinotransferase (AGAT) appeared to be reduced in its activity at later time points. An early reduction in CSF L-arginine concentration was an independent risk factor for poor outcome. Together, these findings further elucidate pathophysiological mechanisms after ICH potentially involved in secondary brain injury and may reveal novel therapeutic targets. [ABSTRACT FROM AUTHOR]

This is a summary document that provides an Australian perspective on the Fourth Consensus Guidelines for the management of postoperative nausea and vomiting. The Australian Society of Anaesthetists has endorsed the Fourth Consensus Guidelines for the management of postoperative nausea and vomiting and has written this document with permission from the authors and the American Society for Enhanced Recovery to provide an Australia-specific summary. [ABSTRACT FROM AUTHOR]

Despite a growing interest in multi-omic research, individual investigators may struggle to collect large-scale omic data, particularly from human subjects. Publicly available datasets can help to address this problem, including those sponsored by the NIH Common Fund, such as the Genotype-Tissue Expression (GTEx) database. This database contains genotype and expression data obtained from 54 non-diseased tissues in human subjects. But these data are often underutilized, because users may find the browsing tools to be counterintuitive or have difficulty navigating the procedures to request controlled data access. Furthermore, there is limited knowledge of these resources among nurse scientists interested in incorporating such information into their programs of research. This article outlines the procedures for using the GTEx database. Next, we provide one exemplar of using this resource to enhance existing research by investigating expression of dopamine receptor type 2 (DRD2) across brain tissues in human subjects. [ABSTRACT FROM AUTHOR]

Background: When designing and developing patient decision aids, guidelines recommend involving patients and stakeholders. There are myriad ways to do this. We aimed to describe how such involvement occurs by synthesizing reports of patient decision aid design and development within a user-centered design framework and to provide context by synthesizing reports of user-centered design applied to other personal health tools. Methods: We included articles describing at least one development step of 1) a patient decision aid, 2) user- or human-centered design of another personal health tool, or 3) evaluation of these. We organized data within a user-centered design framework comprising 3 elements in iterative cycles: understanding users, developing/refining prototype, and observing users. Results: We included 607 articles describing 325 patient decision aid projects and 65 other personal health tool projects. Fifty percent of patient decision aid projects reported involving users in at least 1 step for understanding users, 35% in at least 1 step for developing/refining the prototype, and 84% in at least 1 step for observing users' interaction with the prototype. In comparison, other personal health tool projects reported 91%, 49%, and 92%, respectively. A total of 74% of patient decision aid projects and 92% of other personal health tool projects reported iterative processes, both with a median of 3 iterative cycles. Preliminary evaluations such as usability or feasibility testing were reported in 66% of patient decision aid projects and 89% of other personal health tool projects. Conclusions: By synthesizing design and development practices, we offer evidence-based portraits of user involvement. Those wishing to further align patient decision aid design and development with user-centered design methods could involve users earlier, design and develop iteratively, and report processes in greater detail. [ABSTRACT FROM AUTHOR]

Published reports of uvular necrosis are uncommon and it is possibly an under-reported complication of oropharyngeal manipulation. Uvular necrosis is thought to develop due to ischaemia secondary to mechanical compression of the uvula from oropharyngeal devices. Patients typically present with symptoms of a sore throat within 48 hours postoperatively. It is unclear whether there are any preventable factors, or any specific management strategies that might reduce this complication. Treatment is most commonly conservative management, including observation and simple analgesia. We present 13 cases of uvular injury that were reported to a web-based anaesthesia incident reporting system (webAIRS), a voluntary de-identified anaesthesia incident reporting system in Australia and New Zealand. While the postoperative findings varied, sore throat was the most frequent symptom. Most of the cases resolved spontaneously; the remainder with supportive treatment only. The findings suggest that patients who sustain a uvular injury can be reassured, but they should be advised to seek review early if sore throat persists or any difficulty with breathing develops. [ABSTRACT FROM AUTHOR]

Introduction: Preclinical data implicate large conductance calcium-activated potassium (BKCa) channels in the pathogenesis of headache and migraine, but the exact role of these channels is still unknown. Here, we investigated whether opening of BKCa channels would cause headache and vascular effects in healthy volunteers.Methods: In a randomized, double-blind, placebo-controlled, cross-over study, 21 healthy volunteers aged 18-39 years were randomly allocated to receive an intravenous infusion of 0.05 mg/min BKCa channel opener MaxiPost and placebo on two different days. The primary endpoints were the difference in incidence of headache and the difference in area under the curve (AUC) for headache intensity scores (0-12 hours) and for middle cerebral artery blood flow velocity (VMCA) (0-2 hours) between MaxiPost and placebo. The secondary endpoints were the differences in area under the curve for superficial temporal artery and radial artery diameter (0-2 hours) between MaxiPost and placebo.Results: Twenty participants completed the study. Eighteen participants (90%) developed headache after MaxiPost compared with six (30%) after placebo (p = 0.0005); the difference of incidence is 60% (95% confidence interval 36-84%). The area under the curve for headache intensity (AUC0-12 hours, p = 0.0003), for mean VMCA (AUC0-2 hours, p = 0.0001), for superficial temporal artery diameter (AUC0-2 hours, p = 0.003), and for radial artery diameter (AUC0-2 hours, p = 0.03) were significantly larger after MaxiPost compared to placebo.Conclusion: MaxiPost caused headache and dilation in extra- and intracerebral arteries. Our findings suggest a possible role of BKCa channels in headache pathophysiology in humans. ClinicalTrials.gov, ID: NCT03887325. [ABSTRACT FROM AUTHOR]

Impaired clearance of amyloid-β from choroid plexus is one proposed mechanism behind amyloid deposition in Alzheimer's disease. The present study examined whether clearance from choroid plexus of a cerebrospinal fluid tracer, serving as a surrogate marker of a metabolic waste product, is altered in idiopathic normal pressure hydrocephalus (iNPH), one sub-type of dementia. In a prospective observational study of close to healthy individuals (reference cohort; REF) and individuals with iNPH, we performed standardized T1-weighted magnetic resonance imaging scans before and through 24 h after intrathecal administration of a cerebrospinal fluid tracer (the magnetic resonance imaging contrast agent gadobutrol). Changes in normalized T1 signal within the choroid plexus and cerebrospinal fluid of lateral ventricles were quantified using FreeSurfer. The normalized T1 signal increased to maximum within choroid plexus and cerebrospinal fluid of lateral ventricles 6–9 h after intrathecal gadobutrol in both the REF and iNPH cohorts (enrichment phase). Peak difference in normalized T1 signals between REF and iNPH individuals occurred after 24 h (clearance phase). The results gave evidence for gadobutrol resorption from cerebrospinal fluid by choroid plexus, but with delay in iNPH patients. Whether choroid plexus has a role in iNPH pathogenesis in terms of delayed clearance of amyloid-β remains to be shown. [ABSTRACT FROM AUTHOR]

Background: We need high-quality data to assess the determinants for COVID-19 severity in people with MS (PwMS). Several studies have recently emerged but there is great benefit in aligning data collection efforts at a global scale. Objectives: Our mission is to scale-up COVID-19 data collection efforts and provide the MS community with data-driven insights as soon as possible. Methods: Numerous stakeholders were brought together. Small dedicated interdisciplinary task forces were created to speed-up the formulation of the study design and work plan. First step was to agree upon a COVID-19 MS core data set. Second, we worked on providing a user-friendly and rapid pipeline to share COVID-19 data at a global scale. Results: The COVID-19 MS core data set was agreed within 48 hours. To date, 23 data collection partners are involved and the first data imports have been performed successfully. Data processing and analysis is an on-going process. Conclusions: We reached a consensus on a core data set and established data sharing processes with multiple partners to address an urgent need for information to guide clinical practice. First results show that partners are motivated to share data to attain the ultimate joint goal: better understand the effect of COVID-19 in PwMS. [ABSTRACT FROM AUTHOR]

Background: Cannabis smoking and cigarette smoking often co-occur, yet limited research has investigated the potentially different role impulsivity may play when these behaviours occur in isolation, compared with in combination.Aims: This study examined trait and behavioural impulsivity as a function of both cigarette and cannabis smoking.Methods: Trait impulsivity (BIS-11) was compared between 44 non-smokers, 76 cigarette only, 47 cannabis only and 58 cannabis plus cigarette smokers. The effects of cigarette and cannabis smoking on behavioural impulsivity (stop-signal and information sampling tasks) were then assessed in 87 of these participants during a laboratory session.Results: Trait impulsivity was significantly higher in cigarette smokers than non-smokers, irrespective of cannabis use, except for motor impulsivity, where cigarette smoking was only associated with elevated trait impulsivity in non-smokers of cannabis. Dimensions of trait impulsivity were significantly positively related to cigarette smoking frequency and nicotine dependence, but not to cannabis smoking frequency or dependence. Smoking cigarettes or cannabis was associated with significantly impaired reflection impulsivity relative to not smoking either substance. However, no additional increases in reflection impulsivity were observed in those who smoked both cigarettes and cannabis. No group differences in response inhibition were detected.Conclusions: Heightened trait impulsivity appears to be uniquely related to cigarette smoking, whilst the smoking of cigarettes or cannabis is associated with impairments in reflection impulsivity. Improved outcomes for treating cannabis dependence may result from encouraging concomitant cigarette smokers to cease using both drugs simultaneously in order to reduce heightened impulsivity and risk of relapse. [ABSTRACT FROM AUTHOR]

Many patients spend months waiting for elective procedures, and many have significant modifiable risk factors that could contribute to an increased risk of perioperative morbidity and mortality. The minimal direct contact that usually occurs with healthcare professionals during this period represents a missed opportunity to improve patient health and surgical outcomes. Patients with obesity comprise a large proportion of the surgical workload but are under-represented in prehabilitation studies. Our study piloted a mobile phone based, multidisciplinary, prehabilitation programme for patients with obesity awaiting elective surgery. A total of 22 participants were recruited via the Wollongong Hospital pre-admissions clinic in New South Wales, Australia, and 18 completed the study. All received the study intervention of four text messages per week for six months. Questionnaires addressing the self-reported outcome measures were performed at the start and completion of the study. Forty percent of participants lost weight and 40% of smokers decreased their cigarette intake over the study. Sixty percent reported an overall improved health score. Over 80% of patients found the programme effective for themselves, and all recommended that it be made available to other patients. The cost was A$1.20 per patient per month. Our study showed improvement in some of the risk factors for perioperative morbidity and mortality. With improved methods to increase enrolment, our overall impression is that text message-based mobile health prehabilitation may be a feasible, cost-effective and worthwhile intervention for patients with obesity. [ABSTRACT FROM AUTHOR]

Objective: Patients admitted to hospice are more vulnerable to age-related physiologic changes, polypharmacy, and inappropriate medication use and monitoring. The objective of this study was to characterize the utilization of nonprescription medications in a hospice population. Methods: This was a retrospective study designed to characterize nonprescription or over-the-counter medication use in hospice patients. Data for this study were provided by Seasons Hospice & Palliative Care, a national hospice organization with licenses to operate in 19 states and collected from January 1 to December 31, 2016. The most frequently utilized nonprescription medications, therapeutic classes, and the frequency of patients with at least 1 claim within a therapeutic class were summarized. Results: The final study population included 62 639 orders representing 15 164 patients. The average age was 79.31 years with a standard deviation of 13.31 years. The average length of stay was 26.80 days with a standard deviation of 44.14 days. The top 5 most common medications were as follows: acetaminophen (25.15%), bisacodyl (21.69%), senna (8.35%), omeprazole (4.51%), and docusate (4.46%). Approximately 13 714 (29.67%) of patients were exposed to analgesics, 13 469 (29.14%) to laxatives, and 3535 (7.65%) to antacids or antigas medications. Conclusion: This study highlights numerous opportunities for improvement in the use of nonprescription medications among hospice patients. Reducing the use of nonprescription medications that are ineffective or produce unwanted side effects can contribute to improving the quality of care that patients receive. [ABSTRACT FROM AUTHOR]

Stress urinary incontinence is the involuntary loss of urine on effort or physical exertion. It is a highly prevalent condition affecting both men and women. Treatment is performed in a step-wise approach involving conservative measures, such as weight loss and pelvic floor exercises, medical treatment with duloxetine and a variety of surgical treatment options. However, recent restrictions in the use of synthetic mesh and tape have limited the surgical treatment options, leading to the need for new and novel treatment for stress urinary incontinence. Stem cell therapy is a developing medical field and offers the potential to restore normal physiological function of the urethral sphincter. The effectiveness of stem cell therapy in stress urinary incontinence has been demonstrated in pre-clinical studies, leading to its evaluation in several clinical studies. This review assesses the current evidence for the safety and efficacy of stem cell treatment for patients with stress urinary incontinence who have failed conservative and/or medical management and have not undergone previous surgical treatment for stress urinary incontinence. Evidence Level: Not applicable [ABSTRACT FROM AUTHOR]

While the prevalence of supernumerary teeth (ST) is high in permanent dentition, the etiology of ST in humans remains unclear. However, multiple murine models of ST have elaborated on dated mechanisms traditionally ascribed to ST etiology: one involves the rescue of rudimental teeth, and the second considers the contribution of odontogenic epithelial stem cells. It remains unclear whether these mechanisms of ST formation in mice are applicable to humans. The third dentition is usually regressed apoptotic-that is, the teeth do not completely form in humans. Recently, it was suggested that ST result from the rescue of regression of the third dentition in humans. The present investigation evaluates the proportion of collected general ST cases that evinced a third dentition based on the clinical definition of ST derived from the third dentition. We also investigated the contribution of SOX2-positive odontogenic epithelial stem cells to ST formation in humans. We collected 215 general ST cases from 15,008 patients. We confirmed that the general characteristics of the collected ST cases were similar to the results from previous reports. Of the 215 cases, we narrowed our analysis to the 78 patients who had received a computed tomography scan. The frequency of ST considered to have been derived from the third dentition was 26 out of 78 cases. Evidence of a third dentition was especially apparent in the premolar region, was more common in men, and was more likely among patients with ≥3 ST. SOX2-positive odontogenic epithelial stem cells within the surrounding epithelial cells of developing ST were observed in non-third dentition cases and not in third dentition cases. In conclusion, the third dentition is the main cause of ST in humans. The odontogenic epithelial stem cells may contribute to ST formation in cases not caused by a third dentition. [ABSTRACT FROM AUTHOR]

In three experiments, a virtual preparation for humans of the Morris water task (VMWT) was used. Experiment 1 established that four landmarks were of similar salience. Then, in Experiments 2 and 3, participants were trained to locate a hidden platform in the presence or either two or four of the previous landmarks. In Experiment 2, one pair of groups was trained with four visual landmarks spaced at equal intervals around the edge of the pool, while a second pair was trained with two landmarks only, either relatively close to or far from the hidden platform. After training, a reciprocal overshadowing effect was found: on a test without the platform with two landmarks only (either close to or far from the platform position), the participants trained with four landmarks spent less time in the platform quadrant than those trained with only two. Finally, Experiment 3 showed that at least participants trained with two landmarks relatively close to the platform and then tested with four also performed worse on test than those trained and tested with two close landmarks only. This result suggests that generalisation decrement, rather than associative competition, could provide a sufficient explanation for the overshadowing observed in Experiment 2 in the proximal groups. The present set of experiments extend, although only partially, the generalisation decrement results documented in rats to human participants. [ABSTRACT FROM AUTHOR]