Partial volume correction in longitudinal tau PET studies: is it really needed?

BACKGROUND: [18F]flortaucipir (FTP) tau PET quantification is known to be affected by non-specific binding in off-target regions. Although partial volume correction (PVC) techniques partially account for this effect, their inclusion may also introduce noise and variability into the quantification process. While the impact of these effects has been studied in cross-sectional designs, the benefits and drawbacks of PVC on longitudinal FTP studies is still under scrutiny. The aim of this work was to study the performance of the most common PVC techniques for longitudinal FTP imaging. METHODS: A cohort of 247 individuals from the Alzheimer's Disease Neuroimaging Initiative with concurrent baseline FTP-PET, amyloid-beta (Aß) PET and structural MRI, as well as with follow-up FTP-PET and MRI were included in the study. FTP-PET scans were corrected for partial volume effects using Meltzer's, a simple and popular analytical PVC, and both the region-based voxel-wise (RBV) and the iterative Yang (iY) corrections. FTP SUVR values and their longitudinal rates of change were calculated for regions of interest (ROI) corresponding to Braak Areas I-VI, for a temporal meta-ROI and for regions typically displaying off-target FTP binding (caudate, putamen, pallidum, thalamus, choroid plexus, hemispheric white matter, cerebellar white matter, and cerebrospinal fluid). The longitudinal correlation between binding in off-target and target ROIs was analysed for the different PVCs. Additionally, group differences in longitudinal FTP SUVR rates of change between Aß-negative (A-) and Aß-positive (A+), and between cognitively unimpaired (CU) and cognitively impaired (CI) individuals, were studied. Finally, we compared the ability of different partial-volume-corrected baseline FTP SUVRs to predict longitudinal brain atrophy and cognitive decline. RESULTS: Among off-target ROIs, hemispheric white matter showed the highest correlation with longitudinal FTP SUVR rates from cortical target ROIs (R2=0.28-0.82), with CSF coming in second (R2=0.28-0.42). Application of voxel-wise PVC techniques minimized this correlation, with RBV performing best (R2=0.00-0.07 for hemispheric white matter). PVC also increased group differences between CU and CI individuals in FTP SUVR rates of change across all target regions, with RBV again performing best (No PVC: Cohen's d = 0.26-0.66; RBV: Cohen's d = 0.43-0.74). These improvements were not observed for differentiating A- from A+ groups. Additionally, voxel-wise PVC techniques strengthened the correlation between baseline FTP SUVR and longitudinal grey matter atrophy and cognitive decline. CONCLUSION: Quantification of longitudinal FTP SUVR rates of change is affected by signal from off-target regions, especially the hemispheric white matter and the CSF. Voxel-wise PVC techniques significantly reduce this effect. PVC provided a significant but modest benefit for tasks involving the measurement of group-level longitudinal differences. These findings are particularly relevant for the estimations of sample sizes and analysis methodologies of longitudinal group studies.

Reducing the demand for magnetic resonance imaging scans and prostate biopsies during the early detection of clinically significant prostate cancer: Applying the Barcelona risk-stratified pathway in Catalonia.

PURPOSE: To analyze the reduction in multiparametric magnetic resonance imaging (mpMRI) demand and prostate biopsies after the hypothetical implementation of the Barcelona risk-stratified pathway (BCN-RSP) in a population of the clinically significant prostate cancer (csCaP) early detection program in Catalonia. MATERIALS AND METHODS: A retrospective comparation between the hypothetical application of the BCN-RSP and the current pathway, which relied on pre-biopsy mpMRI and targeted and/or systematic biopsies, was conducted. The BCN-RSP stratify men with suspected CaP based on a prostate specific antigen (PSA) level >10 ng/ml and a suspicious rectal examination (DRE), and the Barcelona-risk calculator 1 (BCN-RC1) to avoid mpMRI scans. Subsequently, candidates for prostate biopsy following mpMRI are selected based on the BCN-RC2. This comparison involved 3,557 men with serum PSA levels > 3.0 ng/ml and/or suspicious DRE. The population was recruited prospectively in 10 centers from January 2021 and December 2022. CsCaP was defined when grade group ≥ 2. RESULTS: CsCaP was detected in 1,249 men (35.1%) and insignificant CaP was overdeteced in 498 (14%). The BCN-RSP would have avoid 705 mpMRI scans (19.8%), and 697 prostate biopsies (19.6%), while 61 csCaP (4.9%) would have been undetected. The overdetection of insignificant CaP would have decrease in 130 cases (26.1%), and the performance of prostate biopsy for csCaP detection would have increase to 41.5%. CONCLUSION: The application of the BCN-RSP would reduce the demand for mpMRI scans and prostate biopsies by one fifth while less than 5% of csCaP would remain undetected. The overdetection of insignificant CaP would decrease by more than one quarter and the performance of prostate biopsy for csCaP detection would increase to higher than 40%.

Effect of 5-Alpha Reductase Inhibitors on Magnetic Resonance Imaging and Prostate Cancer Detection.

Concerns exist regarding the effects of 5-alpha reductase inhibitors (5-ARIs) on multipa-rametric magnetic resonance imaging (mpMRI) and clinically significant prostate cancer (csPCa) detection. Our objective is to analyze the effect of 5-ARI on the prostate imaging-reporting and data system (PI-RADS) distribution and csPCa and insignificant PCa (iPCa) detection. Among 2212 men with serum prostate-specific antigen levels of >3.0 ng/mL and/or suspicious digital rectal examinations who underwent mpMRI and targeted and/or systematic biopsies, 120 individuals exposed to 5-ARI treatment for over a year were identified. CsPCa was defined when the grade group (GG) was >2. The overall csPCa and iPCa detection rates were 44.6% and 18.8%, respectively. Since logistic regression revealed independent predictors of PCa, a randomized matched group of 236 individuals was selected for analysis. The PI-RADS distribution was comparable with 5-ARI exposure (p 0.685). The CsPCa detection rates in 5-ARI-naïve men and 5-ARI-exposed men were 52.6% and 47.4%, respectively (p 0.596). IPCa was detected in 37.6 and 62.5%, respectively (p 0.089). The tumor GG distribution based on 5-ARI exposure was similar (p 0.149) to the rates of csPCa and iPCa across the PI-RADS categories. We conclude that exposure to 5-ARI in suspected PCa men did not change the PI-RADS distribution and the csPCa and iPCa detection rates.

Seroprevalence of IgM/IgG and Neutralizing Antibodies against SARS-CoV-2 in Unvaccinated Young Adults from Mexico Who Reported Not Having Had a Previous COVID-19 Infection.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus that causes coronavirus disease 2019 (COVID-19). It is estimated that more than half of new infections are transmitted by asymptomatic people; therefore, the isolation of symptomatic people is not enough to control the spread of the disease. Methods: A total of 171 unvaccinated young adults (18-35 years) from Sonora, Mexico, who underwent a structured survey to identify prior COVID-19 infections, were included in this study. A qualitative determination of anti-SARS-CoV-2 antibodies in serum was performed by lateral flow immunoassay (Certum IgG/IgM Rapid Test™ cassette kit) and neutralizing antibodies were also determined (GenScript cPass assay). Results: A total of 36 people reported a history of COVID-19 infection, and 135 reported no history of COVID-19. In contrast, 49.6% (67/135) of individuals who had not reported a previous SARS-CoV-2 infection were seropositive to the rapid anti-SARS-CoV-2 antibody test, and 48.1% (65/135) of them had neutralizing antibodies. Conclusions: These results suggest that in young adults, SARS-CoV-2 infections could be asymptomatic in a high percentage of individuals, which could contribute in part to the slow control of the current pandemic due to the large number of asymptomatic cases that are contagious and that could be a silent spread of the virus.

The Role of Digital Rectal Examination Prostate Volume Category in the Early Detection of Prostate Cancer: Its Correlation with the Magnetic Resonance Imaging Prostate Volume.

PURPOSE: To relate the prostate volume category (PVC) assessed with digital rectal examination (DRE)-small, median, and large-and the prostate volumes (PVs) assessed with magnetic resonance imaging (MRI) and transrectal ultrasound (TRUS). To compare the clinically significant prostate cancer (csPCa) discrimination ability of two predictive models based on DRE-PVC and MRI-PV. MATERIALS AND METHODS: A prospective trial of 2,090 men with prostate-specific antigen >3 ng/mL and/or PCa suspicious DRE were prospectively recruited in 10 centers from Catalonia (Spain), between 2021 and 2022, in whom DRE-PVC was assessed. Pre-biopsy MRI, and 12-core TRUS-random biopsy was always performed after 2- to 6-core TRUS-fusion targeted biopsy of prostate imaging-report and data system >3 lesions. In 370 men (17.7%) the DRE-PVC was unconclusive. Among the 1,720 men finally analyzed the csPCa (grade group >2) detection was 42.4%. RESULTS: The median (interquartile range) of TRUS and MRI-PVs of small prostates were 33 mL (19-37 mL) and 35 mL (23-30 mL), p=0.410; in median prostates they were 51 mL (38-58 mL) and 55 mL (48-63 mL) respectively, p<0.001; in large prostates 80 mL (60-100 mL) and 95 mL (75-118 mL) respectively, p<0.001. The predictive models sharing the MRI-PV and DRE-PVC showed areas under the curves of 0.832 (95% confidence interval [CI], 0.813-0.851) and 0.828 (95% CI, 0.809-0.848) respectively, p=0.632, as well as similar net benefit and clinical utility. CONCLUSIONS: PVC was unconclusive in 17% of DREs. MRI-PV overestimated the TRUS-PV in median and large prostates. The predictive models based on MRI-PV and DRE-PVC showed similar efficacy to predict csPCa. PVC assessed with DRE is helpful to predict the csPCa risk before MRI.

Diagnostic delay is associated with uveitis and inflammatory bowel disease in AS: a study of extra-musculoskeletal manifestations in SpA.

OBJECTIVES: To examine the prevalence of extra-musculoskeletal manifestations (EMM) and the association between diagnostic delay and their incidence in AS and PsA. METHODS: This was a retrospective, cohort study comprising two single centre cohorts in Europe and one multicentre cohort in Latin America (RESPONDIA). Crude prevalence of EMMs (uveitis, IBD and psoriasis) was calculated across geographic area and adjusted by direct standardization. Cox proportional hazard analysis was performed to assess the association between diagnostic delay and EMM incidence. RESULTS: Of 3553 patients, 2097 had AS and 1456 had PsA. The overall prevalence of uveitis was 22.9% (95% CI: 21.1, 24.8) in AS and 3.8% (95% CI: 2.9, 5.0) in PsA; 8.1% (95% CI: 7.0, 9.4) and 2.1% (1.3, 2.9), respectively, for IBD; and 11.0% (95% CI: 9.7, 12.4) and 94.6% (93.0, 95.9), respectively, for psoriasis. The EMM often presented before the arthritis (uveitis 45.1% and 33.3%, and IBD 37.4% and 70%, in AS and PsA, respectively). In the multivariable model, longer diagnostic delay (≥5 years) associated with more uveitis (hazard ratio [HR] 4.01; 95% CI: 3.23, 4.07) and IBD events (HR 1.85; 95% CI: 1.28, 2.67) in AS. Diagnostic delay was not significantly associated with uveitis (HR 1.57; 95% CI: 0.69, 3.59) or IBD events (HR 1.59; 95% CI: 0.39, 6.37) in PsA. CONCLUSION: EMMs are more prevalent in AS than PsA and often present before the onset of the articular disease. A longer diagnostic delay is associated with the 'de novo' appearance of uveitis and IBD in AS, highlighting the need to enhance diagnostic strategies to shorten the time from first symptom to diagnosis in SpA.

Apalutamide for prostate cancer: Multicentre and multidisciplinary real-world study of 227 patients.

OBJECTIVE: To evaluate the efficacy and safety of apalutamide prostate cancer compared to the pivotal trials patients and to identify the first subsequent therapy in a real-world setting. METHODS: The study is prospective and observational based on real-world evidence, performed by different medical disciplines and eight academics centres around Barcelona, Spain. It included all patients with metastatic hormone-sensitive prostate cancer (mHSPC) and high-risk non-metastatic castration-resistant prostate cancer (nmCRPC) treated with apalutamide from June 2018 to December 2022. RESULTS: Of 227 patients treated with apalutamide, 10% had ECOG-PS 2, and 41% were diagnosed with new-generation imaging. In the mHSPC group (209 patients), 75 years was the median age, 53% had synchronous metastases, and 22% were M1a. In the nmCRPC (18 patients), 82 years was the median age, and 81% ≤6 months had PSA doubling time. Patients achieved PSA90 in 92% of mHSPC and 50% of nmCRPC and PSA ≤0.2 in 71% of mHSPC and 39% of nmCRPC. Treatment-related adverse events occurred in 40.1% of mHSPC and 44.4% of nmCRPC. After discontinuation of apalutamide due to disease progression, 54.5% in mHSPC and 75% in nmCRPC started chemotherapy, while after discontinuation because of adverse events, 73.3% in mHSPC and 100% in nmCRPC continued with other hormonal-therapies. CONCLUSIONS: The efficacy and safety of apalutamide were similar to that described in the pivotal trials, despite including an older and more comorbid population. Usually, subsequent therapies after apalutamide differed depending on the reason for discontinuation: by disease progression started chemotherapy and by adverse events hormonal sequencing.

Nuevas formas de motivación en la enseñanza de la anatomía humana / New forms of motivation in the teaching of human anatomy

Introducción: Las nuevas generaciones de alumnos (generación Z o nativa digital) en la actualidad han provocado la necesidad de implantar nuevas metodologías docentes en las que el alumnado sea un sujeto activo y participativo en su propio proceso de aprendizaje. Entre estas metodologías, el uso del aprendizaje basado en juegos puede considerarse una alternativa que refuerce a la clásica ‘clase magistral’ y las clases prácticas en la docencia universitaria. Sujetos y métodos: Utilización del aprendizaje basado en juegos (juegos serios) en los alumnos matriculados de la asignatura de Anatomía Humana I (Aparato Locomotor), de primer curso del grado de Medicina en la Universidad de Zaragoza. Resultados: El uso de esta metodología ha sido valorado, mediante encuesta de evaluación de respuesta voluntaria, de manera muy positiva, haciendo hincapié en el efecto que tiene sobre la motivación, la participación y la integración de contenidos teóricos y prácticos. Conclusión: El aprendizaje basado en juegos debe considerarse como una potente alternativa que mejora la motivación, la participación y la integración de contenido en el aula de educación superior.(AU)

Introduction: The new generations of students, such as the current generation Z or digital natives, have provoked the need to implement new teaching methodologies where students are active and participative subjects in their own learning process. Among these methodologies, the use of game-based learning can be considered an alternative to reinforce the classic ‘master class’ in university teaching. Subjects and methods: Use of game-based learning (serious games), in students enrolled in the subject of Human Anatomy I (Locomotor System), first year of the Degree of Medicine at the Universidad de Zaragoza. Results: The use of this methodology has been evaluated, by means of a voluntary evaluation survey, in a very positive way, emphasizing the effect on motivation, participation and integration of theoretical and practical contents. Conclusion: Game-based learning should be considered as a powerful alternative that improves motivation, participation and content integration in the higher education classroom.(AU)

Maternal separation modifies spontaneous synaptic activity in the infralimbic cortex of stress-resilient male rats.

Glutamate and GABA signaling systems are necessary to maintain proper function of the central nervous system through excitation/inhibition (E/I) balance. Alteration of this balance in the medial prefrontal cortex (mPFC), as an effect of early-life stress, may lead to the development of anxiety and depressive disorders. Few studies exist in the infralimbic division of the mPFC to understand the effect of early-life stress at different ages, which is the purpose of the present work. Newborn Sprague Dawley male rats were subjected to maternal separation (MS) for two weeks. First, tests measuring anxiety- and depression-like behaviors were performed on adolescent and adult rats subjected to MS (MS-rats). Then, to establish a relationship with behavioral results, electrophysiological recordings were performed in neurons of the infralimbic cortex in acute brain slices of infant, adolescent, and adult rats. In the behavioral tests, there were no significant differences in MS-rats compared to control rats at any age. Moreover, MS had no effect on the passive membrane properties nor neuronal excitability in the infralimbic cortex, whereas spontaneous synaptic activity in infralimbic neurons was altered. The frequency of spontaneous glutamatergic synaptic events increased in infant MS-rats, whereas in adolescent MS-rats both the frequency and the amplitude of spontaneous GABAergic events increased without any effect on glutamatergic synaptic responses. In adult MS-rats, these two parameters decreased in spontaneous GABAergic synaptic events, whereas only the frequency of glutamatergic events decreased. These data suggest that rats subjected to MS did not exhibit behavioral changes and presented an age-dependent E/I imbalance in the infralimbic cortex, possibly due to differential changes in neurotransmitter release and/or receptor expression.

Safety of early oral ambulatory treatment of adult patients with bloodstream infections discharged from the emergency department.

This study evaluates the safety of early oral ambulatory treatment of adult patients diagnosed with bacteremia after their discharge from the emergency department. A cohort of 206 febrile ambulatory patients was assessed. Bacteremic low-risk patients were recommended an oral treatment and were compared with matched febrile non-bacteremic outpatients. Rates of 14-day mortality and unplanned re-consultations were similar and below 5% in both cohorts, highlighting the safety of oral therapy of low-risk bacteremia, even from its onset.

Identification of the Remains of an Adult Using DNA from Their Deciduous Teeth as a Reference Sample.

In many forensic cases, the identification of human remains is performed by comparing their genetic profile with profiles from reference samples of relatives, usually the parents. Here, we report, for the first time, the identification of the remains of an adult using DNA from the person's deciduous teeth as a reference sample. Fragments of a skeletonized and burned body were found, and a short tandem repeat (STR) profile was obtained. A woman looking for her missing son went to the authorities. When the DNA profile of the woman was compared to a database, a positive match suggested a first-degree kinship with the person to whom the remains belonged. The woman had kept three deciduous molars from her son for more than thirty years. DNA typing of dental pulp was performed. The genetic profiles obtained from the molars and those from the remains coincided in all alleles. The random match probability was 1 in 2.70 × 1021. Thus, the remains were fully identified. In the routine identification of human remains, ambiguous STR results may occur due to the presence of null alleles or other mutational events. In addition, erroneous results can be produced by false matches with close family members or even with people who are completely unrelated to the victim, such that, in some cases, a probability of paternity greater than 99.99% does not necessarily indicate biological paternity. Whenever possible, it is preferable to use reference samples from the putative victim as a source of DNA for identification.

Cataphryxus zapoteca sp. nov. (Isopoda, Bopyridae) and new hosts and records of bopyrid isopods from the Mexican Eastern Pacific.

Based on the examination of diverse crustacean taxa collected along the Mexican Pacific and deposited in the Colección Nacional de Crustáceos of the Instituto de Biología, UNAM, six species of bopyrid isopods were detected. New hosts and localities are reported for Munidion pleuroncodis Markham, 1975, Probopyrus pacificensis Román-Contreras, 1993, Probopyrus markhami Román-Contreras, 1996, Progebiophilus bruscai Salazar-Vallejo & Leija-Tristán, 1990 and Schizobopyrina striata (Nierstrasz & Brender à Brandis, 1929). Cataphryxus zapoteca sp. nov., is described as abdominal parasite of the shrimp Lysmata galapagensis Schmitt; this bopyrid is the second species described in the genus Cataphryxus Shiino, 1936 and the first registered on the American continent. Taxonomic characters, distribution and some reproductive data for five of the six species examined are provided in order to update the knowledge of this parasite group in this Eastern Pacific region.

Occurrence of SARS-CoV-2 viremia is associated with genetic variants of genes related to COVID-19 pathogenesis.

Introduction: SARS-CoV-2 viral load has been related to COVID-19 severity. The main aim of this study was to evaluate the relationship between SARS-CoV-2 viremia and SNPs in genes previously studied by our group as predictors of COVID-19 severity. Materials and methods: Retrospective observational study including 340 patients hospitalized for COVID-19 in the University Hospital La Princesa between March 2020 and December 2021, with at least one viremia determination. Positive viremia was considered when viral load was above the quantifiable threshold (20 copies/ml). A total of 38 SNPs were genotyped. To study their association with viremia a multivariate logistic regression was performed. Results: The mean age of the studied population was 64.5 years (SD 16.6), 60.9% patients were male and 79.4% white non-Hispanic. Only 126 patients (37.1%) had at least one positive viremia. After adjustment by confounders, the presence of the minor alleles of rs2071746 (HMOX1; T/T genotype OR 9.9 p < 0.0001), rs78958998 (probably associated with SERPING1 expression; A/T genotype OR 2.3, p = 0.04 and T/T genotype OR 12.9, p < 0.0001), and rs713400 (eQTL for TMPRSS2; C/T + T/T genotype OR 1.86, p = 0.10) were associated with higher risk of viremia, whereas the minor alleles of rs11052877 (CD69; A/G genotype OR 0.5, p = 0.04 and G/G genotype OR 0.3, p = 0.01), rs2660 (OAS1; A/G genotype OR 0.6, p = 0.08), rs896 (VIPR1; T/T genotype OR 0.4, p = 0.02) and rs33980500 (TRAF3IP2; C/T + T/T genotype OR 0.3, p = 0.01) were associated with lower risk of viremia. Conclusion: Genetic variants in HMOX1 (rs2071746), SERPING1 (rs78958998), TMPRSS2 (rs713400), CD69 (rs11052877), TRAF3IP2 (rs33980500), OAS1 (rs2660) and VIPR1 (rs896) could explain heterogeneity in SARS-CoV-2 viremia in our population.

Multiple chemical sensitivity scoping review protocol: overview of research and MCS construct.

INTRODUCTION: Multiple chemical sensitivity (MCS) has been characterised by reported adverse responses to environmental exposures of common chemical agents (eg, perfumes, paint, cleaning products and other inhaled or ingested agents) in low doses considered non-toxic for the general population. There is currently no consensus on whether MCS can be established as a distinct disorder. METHODS AND ANALYSIS: The scoping review of the literature will be guided by five questions: How is MCS defined and which diagnostic criteria have been proposed? What methods are used to report prevalence and incidence estimates of MCS? What are the characteristics of the body of scientific evidence that addresses whether MCS is a distinct disorder or syndrome? What underlying mechanisms for MCS have been proposed in the scientific literature? Which treatment and management approaches for MCS have been evaluated in empirical research studies? We will conduct a comprehensive search in 14 research databases. Citation screening will be supported by machine learning algorithms. Two independent reviewers will assess eligibility of full-text publications against prespecified criteria. Data abstraction will support concise evidence tables. A formal consultation exercise will elicit input regarding the review results and presentation. The existing research evidence will be documented in a user-friendly visualisation in the format of an evidence map. ETHICS AND DISSEMINATION: Determined to be exempt from review (UP-22-00516). Results will be disseminated through a journal manuscript and data will be publicly accessible through an online data repository. REGISTRATION DETAILS: The protocol is registered in Open Science Framework (osf.io/4a3wu).

Scaling the tail beat frequency and swimming speed in underwater undulatory swimming.

Undulatory swimming is the predominant form of locomotion in aquatic vertebrates. A myriad of animals of different species and sizes oscillate their bodies to propel themselves in aquatic environments with swimming speed scaling as the product of the animal length by the oscillation frequency. Although frequency tuning is the primary means by which a swimmer selects its speed, there is no consensus on the mechanisms involved. In this article, we propose scaling laws for undulatory swimmers that relate oscillation frequency to length by taking into account both the biological characteristics of the muscles and the interaction of the moving swimmer with its environment. Results are supported by an extensive literature review including approximately 1200 individuals of different species, sizes and swimming environments. We highlight a crossover in size around 0.5-1 m. Below this value, the frequency can be tuned between 2-20 Hz due to biological constraints and the interplay between slow and fast muscles. Above this value, the fluid-swimmer interaction must be taken into account and the frequency is inversely proportional to the length of the animal. This approach predicts a maximum swimming speed around 5-10 m.s-1 for large swimmers, consistent with the threshold to prevent bubble cavitation.

Computer simulation of scavenging by hominins and giant hyenas in the late Early Pleistocene.

Consumption of animal-sourced food is an important factor in broadening the diet of early hominins, promoting brain and body growth, and increasing behavioural complexity. However, whether early hominins obtained animal food by scavenging or hunting large mammals remains debated. Sabre-toothed felids have been proposed to facilitate the expansion of early Homo out of Africa into Europe 1.4-0.8 Ma by creating a niche for scavengers in Eurasia as the carcasses abandoned by these felids still contained abundant edible resources. In contrast, it has been argued that the niche for a large scavenger was already occupied in Eurasia by the giant hyena, preventing hominins from utilising this resource. This study shows that sabre-toothed felids generated carcasses rich in edible resources and that hominins were capable of competing with giant hyenas for this resource. The simulation experiments showed that maintaining an optimum group size is essential for the success of the hominin scavenging strategy. Early hominins could outcompete giant hyenas only if they could successfully dispute carcasses with them. Thus, in the presence of a strong competitor, passive scavenging is essentially the same as confrontational scavenging.

A Diagnostic Accuracy Study of Targeted and Systematic Biopsies to Detect Clinically Significant Prostate Cancer, including a Model for the Partial Omission of Systematic Biopsies.

The primary objective of this study was to analyse the current accuracy of targeted and systematic prostate biopsies in detecting csPCa. A secondary objective was to determine whether there are factors predicting the finding of csPCa in targeted biopsies and, if so, to explore the utility of a predictive model for csPCa detection only in targeted biopsies. We analysed 2122 men with suspected PCa, serum PSA > 3 ng/mL, and/or a suspicious digital rectal examination (DRE), who underwent targeted and systematic biopsies between 2021 and 2022. CsPCa (grade group 2 or higher) was detected in 1026 men (48.4%). Discrepancies in csPCa detection in targeted and systematic biopsies were observed in 49.6%, with 13.9% of csPCa cases being detected only in systematic biopsies and 35.7% only in targeted biopsies. A predictive model for csPCa detection only in targeted biopsies was developed from the independent predictors age (years), prostate volume (mL), PI-RADS score (3 to 5), mpMRI Tesla (1.5 vs. 3.0), TRUS-MRI fusion image technique (cognitive vs. software), and prostate biopsy route (transrectal vs. transperineal). The csPCa discrimination ability of targeted biopsies showed an AUC of 0.741 (95% CI 0.721-0.762). The avoidance rate of systematic prostate biopsies went from 0.5% without missing csPCa to 18.3% missing 4.6% of csPCa cases. We conclude that the csPCa diagnostic accuracy of targeted biopsies is higher than that of systematic biopsies. However, a significant rate of csPCa remains detected only in systematic biopsies. A predictive model for the partial omission of systematic biopsies was developed.

Increased Medial Temporal Tau Positron Emission Tomography Uptake in the Absence of Amyloid-ß Positivity.

Importance: An increased tau positron emission tomography (PET) signal in the medial temporal lobe (MTL) has been observed in older individuals in the absence of amyloid-ß (Aß) pathology. Little is known about the longitudinal course of this condition, and its association with Alzheimer disease (AD) remains unclear. Objective: To study the pathologic and clinical course of older individuals with PET-evidenced MTL tau deposition (TMTL+) in the absence of Aß pathology (A-), and the association of this condition with the AD continuum. Design, Setting, and Participants: A multicentric, observational, longitudinal cohort study was conducted using pooled data from the Alzheimer's Disease Neuroimaging Initiative (ADNI), Harvard Aging Brain Study (HABS), and the AVID-A05 study, collected between July 2, 2015, and August 23, 2021. Participants in the ADNI, HABS, and AVID-A05 studies (N = 1093) with varying degrees of cognitive performance were deemed eligible if they had available tau PET, Aß PET, and magnetic resonance imaging scans at baseline. Of these, 128 participants did not meet inclusion criteria based on Aß PET and tau PET biomarker profiles (A+ TMTL-). Exposures: Tau and Aß PET, magnetic resonance imaging, cerebrospinal fluid biomarkers, and cognitive assessments. Main Outcomes and Measures: Cross-sectional and longitudinal measures for tau and Aß PET, cortical atrophy, cognitive scores, and core AD cerebrospinal fluid biomarkers (Aß42/40 and tau phosphorylated at threonine 181 p-tau181 available in a subset). Results: Among the 965 individuals included in the study, 503 were women (52.1%) and the mean (SD) age was 73.9 (8.1) years. A total of 51% of A- individuals and 78% of A+ participants had increased tau PET signal in the entorhinal cortex (TMTL+) compared with healthy younger (aged <39 years) controls. Compared with A- TMTL-, A- TMTL+ participants showed statistically significant, albeit moderate, longitudinal (mean [SD], 1.83 [0.84] years) tau PET increases that were largely limited to the temporal lobe, whereas those with A+ TMTL+ showed faster and more cortically widespread tau PET increases. In contrast to participants with A+ TMTL+, those with A- TMTL+ did not show any noticeable Aß accumulation over follow-up (mean [SD], 2.36 [0.76] years). Complementary cerebrospinal fluid analysis confirmed longitudinal p-tau181 increases in A- TMTL+ in the absence of increased Aß accumulation. Participants with A- TMTL+ had accelerated MTL atrophy, whereas those with A+ TMTL+ showed accelerated atrophy in widespread temporoparietal brain regions. Increased MTL tau PET uptake in A- individuals was associated with cognitive decline, but at a significantly slower rate compared with A+ TMTL+. Conclusions and Relevance: In this study, individuals with A- TMTL+ exhibited progressive tau accumulation and neurodegeneration, but these processes were comparably slow, remained largely restricted to the MTL, were associated with only subtle changes in global cognitive performance, and were not accompanied by detectable accumulation of Aß biomarkers. These data suggest that individuals with A- TMTL+ are not on a pathologic trajectory toward AD.