Long-term strict ant-plant mutualism identity characterises growth rate and leaf shearing resistance of an Amazonian myrmecophyte.

Over 125 million years of ant-plant interactions have culminated in one of the most intriguing evolutionary outcomes in life history. The myrmecophyte Duroia hirsuta (Rubiaceae) is known for its mutualistic association with the ant Myrmelachista schumanni and several other species, mainly Azteca, in the north-western Amazon. While both ants provide indirect defences to plants, only M. schumanni nests in plant domatia and has the unique behaviour of clearing the surroundings of its host tree from heterospecific plants, potentially increasing resource availability to its host. Using a 12-year survey, we asked how the continuous presence of either only M. schumanni or only Azteca spp. benefits the growth and defence traits of host trees. We found that the continuous presence of M. schumanni improved relative growth rates and leaf shearing resistance of Duroia better than trees with Azteca. However, leaf herbivory, dry matter content, trichome density, and secondary metabolite production were the same in all trees. Survival depended directly on ant association (> 94% of trees died when ants were absent). This study extends our understanding of the long-term effects of strict ant-plant mutualism on host plant traits in the field and reinforces the use of D. hirsuta-M. schumanni as a model system suitable for eco-co-evolutionary research on plant-animal interactions.

Effects of Mental Visualization on Plyometric Performance and Self-Confidence of Football Players.

Plyometric training in football is essential for enhancing athletic performance, as it allows for increasing strength and speed in gameplay. Meanwhile, mental visualization improves players' technical play and motor performance during both training and competitions, thereby contributing to an overall sports performance enhancement. Collectively, physical and technical training is thought to boost athletes' confidence in facing competitive demands. Our aim in the present study was to analyze the effectiveness of mental visualization during a plyometric training program for improving strength speed, and competitive self-confidence in young adult football (soccer) players. Our sample consisted of 40 male players aged between 19 and 25 years (M = 20.82; SD = 1.26). We used a quasi-experimental design with a control group and pretest/posttest measurements. The experimental group participated in an 8-week plyometric training program that incorporated visualization tasks, while the control group underwent the same program but without visualization exercises. We found significant improvements for the experimental group on vertical jump (p = .047) and speed (50-m sprints) (p < .034) tests, as well as in their perceived competitive self-confidence (p < .017). These findings suggest that combining plyometric exercises with visualization tasks may contribute to better motor learning, increased lower limb muscle speed and strength, and self-confidence to face competition.

Long-acting HIV Treatments: Study Design, Logistics, and Access.

New long-acting HIV treatment products have the potential to change the HIV epidemic in the United States and globally. Phase 3 clinical trials of HIV treatments tend to underrepresent populations bearing a disproportionate burden of the HIV epidemic-including women, racial minorities, trans and gender-diverse people, older adults, the unhoused, people who inject drugs, those in rural areas, individuals with mental illness, and other marginalized groups. These populations commonly face significant challenges in adhering to daily HIV treatment regimens. Conducting clinical trials of long-acting treatment targeting specific unmet medical needs of these populations can improve understanding of optimal care approaches, broaden the indication for use of long-acting products, and inform treatment guidelines, all of which can influence reimbursement and access policies. Innovative trial designs and programmatic implementation can improve inclusivity for long-acting therapy. This article summarizes discussions of a multistakeholder workshop on study designs for long-acting HIV treatments.

Physical Exercise and Executive Function in the Pediatric Overweight and Obesity Population: A Systematic Review Protocol.

BACKGROUND: Executive function is often altered in overweight/obese children and adolescents, which has a negative impact on their learning and daily life. Furthermore, research has shown the benefits of physical exercise in improving cognitive performance. This protocol aims to define in a detailed and structured manner the procedures that will be conducted for the development of a systematic review of the literature aimed at evaluating the effects of physical exercise on the executive functions of children and adolescents (≤18 years) with overweight/obesity in comparison with peers in control groups. METHODS: The Web of Science, PubMed, Scopus, and EBSCO databases will be searched for longitudinal studies that have at least one experimental and one control group using pre- and post-intervention measures of executive function, including working memory, inhibition, and cognitive flexibility in the pediatric population who are overweight or obese. The risk of bias and certainty of evidence will be assessed using Cochrane RoB2 and GRADE, respectively. Furthermore, Der Simonian-Laird's random effects model will be employed for meta-analyses. The effect sizes will be calculated with 95% confidence intervals, and p values < 0.05 indicate statistical significance for each dimension of executive function in the different groups before and after the intervention. DISCUSSION: The results of this review may be useful for education and health professionals to design treatment plans for overweight/obese children and adolescents, offering potential benefits related to the learning and cognitive abilities of this population. PROSPERO registration number: CRD42023391420.

Engagement in Transformational Leadership by Teachers Influences the Levels of Self-Esteem, Motor Self-Efficacy, Enjoyment, and Intention to Be Active in Physical Education Students.

In the school context, the teacher-student interaction style plays a pivotal role in ensuring optimal adolescent functioning. Over recent years, the significance of transformational teacher leadership in fostering student engagement and positive development has been underscored. This study aimed to examine the correlations between transformational leadership and adolescent self-esteem, motor self-efficacy, enjoyment in physical education classes, and intention for future physical activity. This research used an associative and predictive strategy. A total of 429 adolescents from Málaga, aged between 14 and 16 years (M = 14.97; SD = 0.85), participated in this research, which employed an associative, comparative, and predictive approach. The Transformational Teaching Questionnaire (TTQ), Motor Self-Efficacy Scale (MSES), Intrinsic Satisfaction in Sport Instrument (SSI-EF), and Intention of Being Physically Active Scale (MIFA) were utilized for variable assessment. Correlation, Multiple Regression, and cluster analyses revealed statistically significant correlations between transformational leadership and self-esteem, motor self-efficacy, enjoyment, and future activity intention. Specifically, it was revealed that motivational inspiration predicts self-esteem, motor self-efficacy, enjoyment, and intention for physical activity, whereas intellectual stimulation predicts motor self-efficacy, enjoyment, and intention for physical activity. Notably, the transformational leadership factors of intellectual stimulation and motivational inspiration were observed to predict scores across other variables, particularly enjoyment in physical education classes, both overall and by gender. These findings suggest that transformational leadership in physical education classes can significantly enhance student experiences, thereby promoting adherence to physical activity and healthy lifestyles among adolescents.

Elevated homocysteine is associated with increased rates of epigenetic aging in a population with mild cognitive impairment.

Elevated plasma total homocysteine (tHcy) is associated with the development of Alzheimer's disease and other forms of dementia. In this study, we report the relationship between tHcy and epigenetic age in older adults with mild cognitive impairment from the VITACOG study. Epigenetic age and rate of aging (ROA) were assessed using various epigenetic clocks, including those developed by Horvath and Hannum, DNAmPhenoAge, and with a focus on Index, a new principal component-based epigenetic clock that, like DNAmPhenoAge, is trained to predict an individual's "PhenoAge." We identified significant associations between tHcy levels and ROA, suggesting that hyperhomocysteinemic individuals were aging at a faster rate. Moreover, Index revealed a normalization of accelerated epigenetic aging in these individuals following treatment with tHcy-lowering B-vitamins. Our results indicate that elevated tHcy is a risk factor for accelerated epigenetic aging, and this can be ameliorated with B-vitamins. These findings have broad relevance for the sizable proportion of the worldwide population with elevated tHcy.

Neuropsychological analysis of anxiety and executive control of motor patterns in athletes and non-athletes.

Introduction: Even simple tapping tasks require cognitive processes. Some variants of the Finger Tapping Test (FTT) may reveal cognitive aspects associated with frontal processing, including executive functions such as inhibition, or emotional aspects such as anxiety. A context of particular interest for the application of cognitive-motor-anxiety interactions is sports. Although athletes generally exhibit better anxiety levels, they may experience heightened anxiety before important competitions. The problem lies in determining whether the application of anxiety control techniques can be useful in pre-competition situations, given the lack of quick and easy methods to detect if an athlete is experiencing anxiety at a particular moment. Methods: This exploratory study evaluated anxiety using online versions of questionnaires (ISRA, the Competitive State Anxiety Inventory-2, and STAI) and applied a variant of the FTT to 204 participants, both athletes and non-athletes. The scores were compared and correlated. Results: Athletes exhibited lower general anxiety and greater cognitive resistance to interference (better cognitive inhibition). Non-athletes displayed a particular parameter in the FTT variant that differed from the one obtained by athletes and exhibited higher anxiety levels. In the athletes' group only, anxiety was correlated with a specific parameter of the FTT task. Discussion: Our conclusion is that this parameter holds potential relevance in elite sports performance to detect if an athlete is experiencing anxiety. It could be of particular interest in psychological interventions in sports. Further investigation is warranted to fully explore this potential.

KIBRA anchoring the action of PKMζ maintains the persistence of memory.

How can short-lived molecules selectively maintain the potentiation of activated synapses to sustain long-term memory? Here, we find kidney and brain expressed adaptor protein (KIBRA), a postsynaptic scaffolding protein genetically linked to human memory performance, complexes with protein kinase Mzeta (PKMζ), anchoring the kinase's potentiating action to maintain late-phase long-term potentiation (late-LTP) at activated synapses. Two structurally distinct antagonists of KIBRA-PKMζ dimerization disrupt established late-LTP and long-term spatial memory, yet neither measurably affects basal synaptic transmission. Neither antagonist affects PKMζ-independent LTP or memory that are maintained by compensating PKCs in ζ-knockout mice; thus, both agents require PKMζ for their effect. KIBRA-PKMζ complexes maintain 1-month-old memory despite PKMζ turnover. Therefore, it is not PKMζ alone, nor KIBRA alone, but the continual interaction between the two that maintains late-LTP and long-term memory.

Newborn auditory brainstem response and sudden infant death syndrome.

Sudden infant death syndrome (SIDS)-the sudden and unexplained death of a seemingly healthy infant, <1 year old-may be associated with abnormalities in the brain regions that underlie breathing and arousal during sleep. While post-mortem studies suggest abnormalities in SIDS infants' brainstems, there are no studies of these infants' brainstem function before death. One way to assess the function of the brainstem is with auditory brainstem response (ABR), a routine hearing-screening method that noninvasively measures the brainstem's response to sound. We hypothesize that anomalies in newborns' ABR measures may predict SIDS. Indeed, previous studies identified abnormalities in ABR characteristics in small samples of near-miss SIDS infants hospitalized for infant apnea syndrome. However, there is a need to examine the ABRs of infants who died of SIDS. Therefore, in the current study, we propose integrating two secondary datasets to examine newborns' ABRs (N = 156,972), including those who later died of SIDS (n = ~42; .27 out of every 1000 infants), using existing archived records of neonatal ABR results from a sample of newborns born in Florida. We hypothesize that infants who die from SIDS are more likely than non-SIDS infants to have abnormal ABRs as newborns. Understanding the association between SIDS and ABR may facilitate more accurate identification of an infant's risk for SIDS at birth, enabling increased monitoring, which may facilitate interventions and improve survivorship.

Quick Estimation of Minimum Hearing Levels Using a Binaural Multifrequency Stimulus Paradigm: Proof of Concept.

OBJECTIVES: Objective estimation of minimum hearing levels using auditory brainstem responses (ABRs) elicited by single frequency tone-bursts presented monaurally is currently considered the gold standard. However, the data acquisition time to estimate thresholds (for both ears across four audiometric frequencies) using this method usually exceeds the sleep time (ranging between 35 and 49 minutes) in infants below 4 months, thus providing incomplete information of hearing status which in turn delays timely clinical intervention. Alternate approaches using faster rate, or tone-burst trains have not been readily accepted due to additional hardware and software requirements. We propose here a novel binaural multifrequency stimulation paradigm wherein several stimuli of different frequencies are presented binaurally in an interleaved manner. The rationale here is that the proposed paradigm will increase acquisition efficiency, significantly reduce test time, and improve accuracy by incorporating an automatic wave V detection algorithm. It is important to note that this paradigm can be easily implemented in most commercial ABR systems currently used by most clinicians. DESIGN: Using this binaural multifrequency paradigm, ear specific ABRs were recorded in 30 normal-hearing young adults to both tone-bursts, and narrow-band (NB) iChirps at 500, 1000, 2000, and 4000 Hz. Comparison of ABRs elicited by tone-bursts and narrow-band chirps allowed us to determine if NB iChirps elicited a more robust wave V component compared with the tone-bursts. ABR data were characterized by measures of minimum hearing levels; wave V amplitude; and response detectability for two electrode configurations (high forehead-C7; and high forehead-linked mastoids). RESULTS: Consistent with the research literature, wave V response amplitudes were relatively more robust for NB iChirp stimuli compared with tone-burst stimuli. The easier identification and better detectability of wave V for the NB iChirps at lower stimulus levels contributed to their better thresholds compared with tone-burst elicited responses. It is important to note that binaural multifrequency hearing levels close to minimum hearing levels were determined in approximately 22 minutes using this paradigm-appreciably quicker than the 45 to 60 minutes or longer time required for threshold determination using the conventional single frequency method. CONCLUSIONS: Our novel and simple paradigm using either NB iChirps or tone-bursts provides a reliable method to rapidly estimate the minimum hearing levels across audiometric frequencies for both ears. Incorporation of an automatic wave V detection algorithm increases objectivity and further reduce test time and facilitate early hearing identification and intervention.

High-risk human papilloma virus status & outcomes for penile squamous cell carcinoma: A single institution experience.

OBJECTIVES: There is a paucity of data on North American cohorts of patients with penile squamous cell carcinoma (pSCC). Herein, we aimed to assess the sensitivity of various modalities to identify human papillomavirus (HPV) status, determine the prevalence of high-risk HPV-positivity, and evaluate the prognostic impact of relevant clinicopathologic variables. METHODS: Patients with pSCC (n = 121) consecutively treated with partial/total penectomy (2000-2022) at a single institution were included. HPV status (based on immunohistochemistry [IHC], in situ hybridization [ISH], and panviral metagenomic sequencing [PMS]), histologic features, and outcomes were reviewed. Outcome events included death due to disease and progression. RESULTS: The majority of patients were white (105/121, 86.8%). Thirty-seven (30.6%) were high-risk HPV-positive, and morphologic evaluation had a sensitivity of 97.3% (95% confidence interval [CI], 86.2-99.5) for predicting high-risk HPV status compared to IHC/ISH/PMS. Disease progression was more common among high-risk HPV-negative compared to high-risk HPV-positive patients (HR 2.74, CI 1.12-8.23, P = 0.03). Moreover, among high-risk HPV-negative patients, those with moderate-poorly differentiated tumors had increased disease-specific mortality (32.6%, CI 17.1-48.1) compared to those with well-differentiated tumors (0%). Among high-risk HPV-positive patients, those with basaloid morphology had lower disease-specific mortality (0% vs 14.4%, CI 0.0-33.1). CONCLUSIONS: We demonstrate high-risk HPV-positivity in approximately one-third of patients with pSCC. Morphologic evaluation alone had a high sensitivity in correctly determining HPV status. Our results suggest that high-risk HPV status and morphologic features (differentiation in high-risk HPV-negative, and basaloid subtype in high-risk HPV-positive pSCC) may have prognostic value.

Nasal resistance and inflammation: mechanisms for obstructive sleep apnea from chronic rhinosinusitis.

STUDY OBJECTIVES: We have previously estimated that the prevalence of obstructive sleep apnea (OSA) among World Trade Center (WTC) rescue and recovery workers is 75% and identified that having symptoms of chronic rhinosinusitis (CRS) is an independent risk factor for OSA in this population. Nasal inflammation and/or elevated awake nasal resistance that carried over into sleep could explain this association. To understand the mechanism(s) for the elevated risk of OSA observed in WTC responders with chronic rhinosinusitis (CRS) symptoms we examined if elevated awake supine nasal resistance was associated with OSA, CRS and/or nasal inflammatory biomarkers. METHODS: 601 individuals (83% male, average age 53 years, BMI=29.9 ± 5.5 kg/m2) enrolled in the WTC Health Program and without significant pre-9/11 snoring, underwent two nights of home sleep apnea testing, measurements of anterior rhinomanometry in the supine position, and nasal lavage. RESULTS: Awake supine nasal resistance was not associated with OSA; 74.8% and 74.4% of the participants with low and high nasal resistance respectively, had OSA (P=NS). Patients with CRS had elevated nasal inflammatory markers (IL6, IL8, ECP and Neut) but did not have high nasal resistance. Nasal inflammatory markers were not correlated with nasal resistance. CONCLUSIONS: As awake nasal resistance did not explain the relationship of CRS to OSA in this large and well characterized dataset, our findings suggest that either "sleep" nasal resistance or other factors such as increased supraglottic inflammation, perhaps through impairing upper airway reflex mechanisms, or systemic inflammation are involved in the pathophysiology of OSA in the WTC population.

Lack of association of impaired upper airway sensation with the presence or absence of obstructive sleep apnoea or chronic rhinosinusitis in World Trade Center responders.

OBJECTIVE: Examine sensory function of the upper airway in four groups of subjects recruited from the World Trade Centre General Responder Cohort (WTCGRC), with/without obstructive sleep apnoea (OSA), and with/without chronic rhinosinusitis (CRS). METHODS: Upper airway sensory function was determined using 2-point discrimination (2-PD) and vibration threshold (VT) in 163 WTCGRC subjects with both OSA and CRS (cases), OSA or CRS alone and without OSA or CRS (controls). Presence of OSA was determined from clinical sleep studies or home sleep testing. Presence of CRS was determined by nasal symptom questionnaire. The relationship between the presence of OSA and CRS and upper airway sensory impairment was assessed using linear regression analysis with each of 2PD and VT sensory threshold values as the dependent variable; OSA, CRS and their interaction were the independent variables. Age, gender and body mass index were covariates in the statistical model. The primary analysis was comparison of OSA+CRS versus controls (no OSA and no CRS) evaluated by linear contrasts. RESULTS: There were no differences in 2-PD or VT in those with OSA+CRS, OSA and CRS alone or controls. However, both 2-PD and VT were significantly higher in the WTCGRC controls compared with values seen in historical controls using the same methodology (median 2-PD 13.0; CI (11.0 to 13.5) vs 10.5; CI (8 to 11); VT: mean±SEM (9.3±0.6 vs 2.2±0.1)). CONCLUSION: While no differences were found in upper airway sensation between cases of OSA and CRS versus controls in the WTGRC population, there was evidence of impaired upper airway sensation in the WTGRC overall.

Cobalt-Mediated Photochemical C-H Arylation of Pyrroles.

Precious metal complexes remain ubiquitous in photoredox catalysis (PRC) despite concerted efforts to find more earth-abundant catalysts and replacements based on 3d metals in particular. Most otherwise plausible 3d metal complexes are assumed to be unsuitable due to short-lived excited states, which has led researchers to prioritize the pursuit of longer excited-state lifetimes through careful molecular design. However, we report herein that the C-H arylation of pyrroles and related substrates (which are benchmark reactions for assessing the efficacy of photoredox catalysts) can be achieved using a simple and readily accessible octahedral bis(diiminopyridine) cobalt complex, [1-Co](PF6)2. Notably, [1-Co]2+ efficiently functionalizes both chloro- and bromoarene substrates despite the short excited-state lifetime of the key photoexcited intermediate *[1-Co]2+ (8 ps). We present herein the scope of this C-H arylation protocol and provide mechanistic insights derived from detailed spectroscopic and computational studies. These indicate that, despite its transient existence, reduction of *[1-Co]2+ is facilitated via pre-assembly with the NEt3 reductant, highlighting an alternative strategy for the future development of 3d metal-catalyzed PRC.

Associations between Fluid Intelligence and Physical Fitness in School Children.

Previous research has highlighted that active lifestyles that contribute to improved physical fitness are positively related to cognitive functioning in children and adolescents. Specifically, the increase in physical condition at school age is considered relevant because it is related to better cognitive ability and greater academic performance. Thus, the aim of this study was to analyze the relationships between explosive strength, speed-agility, and fluid reasoning in schoolchildren. To achieve this objective, an associative, comparative, and predictive design was used in this research. A total of 129 children participated in this study (age: M = 9.48; SD = 0.99). To assess fluid reasoning, the Raven test's Standard Progressive Matrices Subtest and the Wechsler Intelligence Scale for Children (WISC-V) were used. To assess physical fitness, the speed-agility test and the horizontal jump test (ALPHA-fitness battery tests), as well as the ball throw test (2 kg), were used. The results showed that the speed-agility test significantly predicted WISC-V Fluid Reasoning Index scores, and the medicine ball toss test significantly predicted Raven test scores. The results obtained highlight the associations between physical condition at these ages and fluid intelligence. This suggests that promoting active lifestyles that improve physical fitness could have a positive impact on children's cognitive health.

Comparison of a modified staging system with 8th edition AJCC criteria in a North American cohort of pT2/pT3 HPV-negative penile squamous cell carcinoma.

The staging for pT2/pT3 penile squamous cell carcinoma (pSCC) has undergone major changes. Some authors proposed criteria wherein the distinction between pT2/pT3 was made using the same histopathological variables that are currently utilized to differentiate pT1a/pT1b. In this single-institution, North American study, we focused on (HPV-negative) pT2/3 pSCCs (i.e., tumors invading corpus spongiosum/corpus cavernosum), and compared the prognostic ability of the following systems: (i) AJCC (8th edition) criteria; (ii) modified staging criteria proposed by Sali et al. (Am J Surg Pathol. 2020; 44:1112-7). In the proposed system, pT2 tumors were defined as those devoid of lymphovascular invasion (LVI) or perineural invasion (PNI), and were not poorly differentiated; whereas pT3 showed one or more of the following: LVI, PNI, and/or grade 3. 48 pT2/pT3 cases were included (AJCC, pT2: 27 and pT3: 21; Proposed, pT2: 22 and pT3: 26). The disease-free survival (DFS) and progression-free survival (PFS) did not differ between pT2 and pT3, following the current AJCC definitions (p = 0.19 and p = 0.10, respectively). When the pT2/3 stages were reconstructed using the modified criteria, however, a statistically significant difference was present in both DFS and PFS between pT2 and pT3 (p = 0.004 and p = 0.003, respectively). The proposed staging system has the potential to improve the prognostication of pT2/pT3 tumors in pSCC. Each of these histopathologic variables has been shown to have a significant association with outcomes in pSCC, which is an advantage. Further studies are needed to demonstrate the utility of this modified staging system in patient populations from other geographic regions.

Tafel Slope Plot as a Tool to Analyze Electrocatalytic Reactions.

Kinetic and nonkinetic contributions to the Tafel slope value can be separated using a Tafel slope plot, where a constant Tafel slope region indicates kinetic meaningfulness. Here, we compare the Tafel slope values obtained from linear sweep voltammetry to the values obtained from chronoamperometry and impedance spectroscopy, and we apply the Tafel slope plot to various electrocatalytic reactions. We show that similar Tafel slope values are observed from the different techniques under high-mass-transport conditions for the oxygen evolution reaction on NiFeOOH in 0.2 M KOH. However, for the alkaline hydrogen evolution reaction and the CO2 reduction reaction, no horizontal Tafel slope regions were observed. In contrast, we obtained the expected Tafel slope of 30 mV/dec for the HER on Pt in 1 M HClO4. We argue that widespread application of the Tafel slope plot, or similar numerical differentiation techniques, would result in an improved comparison of kinetic data for many electrocatalytic reactions when the traditional Tafel plot analysis is ambiguous.

Nickel as Electrocatalyst for CO(2) Reduction: Effect of Temperature, Potential, Partial Pressure, and Electrolyte Composition.

Electrochemical CO2 reduction on Ni has recently been shown to have the unique ability to produce longer hydrocarbon chains in small but measurable amounts. However, the effects of the many parameters of this reaction remain to be studied in more detail. Here, we have investigated the effect of temperature, bulk CO2 concentration, potential, the reactant, cations, and anions on the formation of hydrocarbons via a chain growth mechanism on Ni. We show that temperature increases the activity but also the formation of coke, which deactivates the catalyst. The selectivity and thus the chain growth probability is mainly affected by the potential and the electrolyte composition. Remarkably, CO reduction shows lower activity but a higher chain growth probability than CO2 reduction. We conclude that hydrogenation is likely to be the rate-determining step and hypothesize that this could happen either by *CO hydrogenation or by termination of the hydrocarbon chain. These insights open the way to further development and optimization of Ni for electrochemical CO2 reduction.

Single nucleotide polymorphism (SNP) chromosomal microarray as a diagnostic tool for mucinous tubular and spindle cell carcinoma: A validation study.

Mucinous tubular and spindle cell carcinoma (MTSCC) shows significant overlap with papillary renal cell carcinoma (PRCC), and harbor recurrent copy-number alterations (CNA). We evaluated 16 RCC with features suggestive of MTSCC using chromosomal microarrays. The cohort was comprised of 8 females and males, each, with an age range of 33-79 years (median, 59), and a tumor size range of 3.4-15.5 cm (median, 5.0). Half the tumors were high-grade (8/16, 50%) with features such as necrosis, marked cytologic atypia, and sarcomatoid differentiation, and 5/16 (31%) were high stage (≥pT3a). Three (of 16, 19%) cases had a predominant (>95%) spindle cell component, whereas 5/16 (31%) were composed of a predominant (>95%) epithelial component. Most cases (12/16, 75%) exhibited a myxoid background and/or extravasated mucin, at least focally. Twelve (of 16, 75%) cases demonstrated CNA diagnostic of MTSCC (losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22). In addition, 2 high-grade tumors showed loss of CDKN2A/B, and gain of 1q, respectively, both of which are associated with aggressive behavior. Three (of 16, 19%) cases, demonstrated nonspecific CNA, and did not meet diagnostic criteria for established RCC subtypes. One (of 16, 6%) low-grade epithelial predominant tumor (biopsy) demonstrated characteristic gains of 7, 17, and loss of Y, diagnostic of PRCC. MTSCC can be a morphologically heterogenous tumor. Our study validates the detection of characteristic chromosomal CNA for diagnostic use that may be useful in challenging cases with unusual spindle cell or epithelial predominant features, as well as in high-grade tumors.