Presumptive motor neuron degeneration in an adult cat.

An 8-year-old neutered male Bengal cat was referred because of a 1-year history of progressive and relapsing generalized muscle weakness and muscle atrophy. Before referral, the cat was treated with immunosuppressive doses of oral prednisolone, intermittently for 6 mo, and had responded well when the immunosuppressive dose was maintained. Generalized paresis, diffuse muscle atrophy, and diminished spinal reflexes were present in all limbs, consistent with a generalized lower motor neuron disease. Histopathologic evaluation of muscle biopsies confirmed a pattern of muscle fiber atrophy consistent with chronic and severe denervation. No specific abnormalities were identified in the nerve biopsy or within intramuscular nerve branches. A presumptive antemortem diagnosis of an adult-onset motor neuron degeneration resembling amyotrophic lateral sclerosis (ALS) or spinal muscle atrophy was suspected. However, given the response to immunosuppressive doses of corticosteroids, an autoimmune process or other degenerative process could not be definitively excluded. Key clinical message: In this case, an adult cat had a chronic, progressive history of lower motor neuron weakness and absent spinal reflexes; biopsies revealed a neurogenic pattern of muscle fiber atrophy and histologically normal peripheral nerve and intramuscular nerve branches. Although reports of motor neuron disease are rare in the veterinary literature, this case report highlights the importance of muscle and nerve biopsies that lead to a presumptive diagnosis of motor neuron degeneration.

Dégénérescence présumée des neurones moteurs chez un chat adulteUn chat Bengal mâle castré de 8 ans a été référé en raison d'un an d'antécédents de faiblesse musculaire généralisée progressive et récidivante et d'atrophie musculaire. Avant le transfert, le chat a été traité avec des doses immunosuppressives de prednisolone orale, par intermittence pendant 6 mois, et a bien répondu lorsque la dose immunosuppressive a été maintenue. Une parésie généralisée, une atrophie musculaire diffuse et des réflexes spinaux diminués étaient présents dans tous les membres, compatibles avec une maladie généralisée des neurones moteurs inférieurs. L'évaluation histopathologique des biopsies musculaires a confirmé un schéma d'atrophie des fibres musculaires compatible avec une dénervation chronique et sévère. Aucune anomalie spécifique n'a été identifiée dans la biopsie nerveuse ou dans les branches nerveuses intramusculaires. Un diagnostic antemortem présomptif d'une dégénérescence des neurones moteurs d'apparition adulte ressemblant à la sclérose latérale amyotrophique (SLA) ou à une atrophie musculaire spinale a été suspecté. Cependant, compte tenu de la réponse aux doses immunosuppressives de corticostéroïdes, un processus auto-immun ou un autre processus dégénératif ne pouvait être définitivement exclu.Message clinique clé :Dans ce cas, un chat adulte avait des antécédents chroniques et progressifs de faiblesse des neurones moteurs inférieurs et d'absence de réflexes spinaux; les biopsies ont révélé un schéma neurogène d'atrophie des fibres musculaires et des branches nerveuses périphériques et intramusculaires histologiquement normales. Bien que les rapports de maladie des neurones moteurs soient rares dans la littérature vétérinaire, ce rapport de cas souligne l'importance des biopsies musculaires et nerveuses qui conduisent à un diagnostic présomptif de dégénérescence des neurones moteurs.(Traduit par Dr Serge Messier).

A Descriptive, Post Hoc Analysis of Efficacy and Safety of Risankizumab in Diverse Racial and Ethnic Patient Populations With Moderate-to-Severe Psoriasis.

INTRODUCTION: Historically, patients with skin of color are underdiagnosed with psoriasis and underrepresented in clinical trials. In this study, we assess the efficacy and safety of risankizumab in patients with moderate-to-severe plaque psoriasis by race and ethnicity in the open label extension LIMMitless (NCT03047395). METHODS: Patients received continuous treatment with 150 mg risankizumab through their initial trial and the open label extension. Patients self-identified their race and ethnicity. Efficacy was assessed using Psoriasis Area Severity Index (PASI) and Dermatology Life Quality Index (DLQI). Safety is reported by events/100 patient-years. RESULTS: A total of 897 patients (race: 662 White, 196 Asian, 25 Black or African American, 14 Other; ethnicity: 98 Hispanic or Latino, 799 non-Hispanic or Latino) were included in this analysis. Compared to baseline, patients had a mean percent reduction in PASI between 94.6% (Asian) and 99.3% (Black or African American) and reported mean percent improvements in DLQI ranging from 87.1% (Asian and Black or African American) to 93.7% (Hispanic or Latino) at week 100. CONCLUSION: While the data presented here comprise a small retrospective descriptive analysis and cannot detect statistical differences, efficacy of risankizumab for the treatment of moderate-to-severe plaque psoriasis appears similar across the racial and ethnic groups studied and no new safety signals were detected.

The importance of pathway programs in increasing diversity in dermatology: Efforts made by the American Academy of Dermatology.

Our country's population continues to diversify, highlighting the need for an equally diverse physician workforce to care for patients. Unfortunately, the percentage of underrepresented minority residents in dermatology has remained relatively unchanged over the past several years. To address this disparity, the American Academy of Dermatology created the Pathways Programs to focus on early exposure to dermatology, skill-building workshops, research, and mentorship. The overarching goal is to increase the number of underrepresented minority dermatologists, which will result in improved patient care and mitigation of healthcare disparities.

Ultrasound-estimated hepatorenal index: diagnostic performance and interobserver agreement for pediatric liver fat quantification.

BACKGROUND: Semiquantitative and quantitative sonographic techniques have the potential for screening and surveillance of children at risk of nonalcoholic fatty liver disease. OBJECTIVE: To determine diagnostic performance and interobserver agreement of hepatorenal index (HRI) for pediatric ultrasound-based liver fat quantification. MATERIALS AND METHODS: In an institutional review board (IRB)-approved retrospective study (April 2014 to April 2023), children (< 18 years) with clinically performed magnetic resonance imaging (MRI) scans for liver fat quantification were assessed. Inclusion criteria required availability of abdominal ultrasound within 3 months of quantitative MRI. Three blinded readers subjectively assessed for sonographic hepatic steatosis and calculated HRI. MRI proton density fat fraction (PDFF) was the reference standard. Interobserver agreement, correlation with PDFF, and optimal HRI (using ROC analysis) values were analyzed. The significance level was set at p < 0.05. RESULTS: A total of 41 patients (25 male) with median (interquartile range (IQR)) age of 13 (10-15) years were included. Median (IQR) MRI PDFF was 11.30% (2.70-17.95%). Hepatic steatosis distribution by MRI PDFF included grade 0 (34%), grade 1 (15%), grade 2 (22%), and grade 3 (29%) patients. Intraclass correlation coefficient for HRI among the three readers was 0.61 (95% CI 0.43-0.75) (p < 0.001). Moderate correlation was observed between manually estimated HRI and PDFF for each reader (r = 0.62, 0.67, and 0.67; p < 0.001). Optimal HRI cutoff was found to be 1.99 to diagnose hepatic steatosis (sensitivity 89%, specificity 93%). Median (IQR) HRI for each MRI grade of hepatic steatosis (0-4) was as follows: 1.2 (1.1-1.5), 2.6 (1.1-3.3), 3.6 (2.6-5.4), 5.6 (2.6-10.9), respectively (p < 0.001). CONCLUSION: Ultrasound-estimated HRI has moderate interobserver agreement and moderate correlation with MRI-derived PDFF. HRI of 1.99 maximizes accuracy for identifying pediatric liver fat.

Neuromodulators in Skin of Color: An International Review.

BACKGROUND: As the racial/ethnic diversity of the US population grows, it is imperative for dermatologists to recognize the nuances in the aesthetic treatment of diverse populations. OBJECTIVE: This comprehensive review explores the safety and efficacy of botulinum toxin A (BTX-A) in skin of color (SOC) populations and highlights variations in aging patterns, skin properties, and aesthetic concerns in SOC populations. MATERIALS AND METHODS: A review of PubMed/MEDLINE databases from 2004 to 2024 was performed using combinations of the terms botulinum toxin, SOC, Fitzpatrick, race/ethnicity, and Asian, Latin American, Caribbean, Middle Eastern, African, and Pacific countries. RESULTS: Twenty-three articles examining the use of BTX-A in SOC populations were identified. Twelve studies were from East Asia, 5 from the United States and/or Canada, 3 from South Asia/Southeast Asia, 2 from South America, and 1 from the Middle East. Available data suggest that BTX-A is efficacious and well tolerated in SOC populations. CONCLUSION: Increased SOC representation in clinical trials may guide the development of tailored treatment approaches to optimize aesthetic outcomes for patients with SOC. A comprehensive knowledge of the variations in aging patterns, skin properties, and aesthetic concerns across SOC populations is essential for providing culturally sensitive cosmetic dermatologic care for diverse populations.

Congenital Chest Lesions and Interventions.

Anomalies of the fetal chest require advanced imaging with ultrasound and MR imaging as well as expertise on the part of the interpreting pediatric radiologist. Congenital diaphragmatic hernia and congenital lung malformation are the most frequently seen, and in both conditions, the radiologist should provide both detailed anatomic description and measurement data for prognostication. This article provides a detailed approach to imaging the anatomy, in-depth explanation of available measurements and prognostic value, and keys to identifying candidates for fetal intervention. Less common congenital lung tumors and mediastinal and chest wall masses are also reviewed.

The αC-ß4 loop controls the allosteric cooperativity between nucleotide and substrate in the catalytic subunit of protein kinase A.

Allosteric cooperativity between ATP and substrates is a prominent characteristic of the cAMP-dependent catalytic subunit of protein kinase A (PKA-C). This long-range synergistic action is involved in substrate recognition and fidelity, and it may also regulate PKA's association with regulatory subunits and other binding partners. To date, a complete understanding of this intramolecular mechanism is still lacking. Here, we integrated NMR(Nuclear Magnetic Resonance)-restrained molecular dynamics simulations and a Markov State Model to characterize the free energy landscape and conformational transitions of PKA-C. We found that the apoenzyme populates a broad free energy basin featuring a conformational ensemble of the active state of PKA-C (ground state) and other basins with lower populations (excited states). The first excited state corresponds to a previously characterized inactive state of PKA-C with the αC helix swinging outward. The second excited state displays a disrupted hydrophobic packing around the regulatory (R) spine, with a flipped configuration of the F100 and F102 residues at the αC-ß4 loop. We validated the second excited state by analyzing the F100A mutant of PKA-C, assessing its structural response to ATP and substrate binding. While PKA-CF100A preserves its catalytic efficiency with Kemptide, this mutation rearranges the αC-ß4 loop conformation, interrupting the coupling of the two lobes and abolishing the allosteric binding cooperativity. The highly conserved αC-ß4 loop emerges as a pivotal element to control the synergistic binding of nucleotide and substrate, explaining how mutations or insertions near or within this motif affect the function and drug sensitivity in homologous kinases.

Micrometeorite collections: a review and their current status.

Micrometeorites are estimated to represent the main part of the present flux of extraterrestrial matter found on the Earth's surface and provide valuable samples to probe the interplanetary medium. Here, we describe large and representative collections of micrometeorites currently available to the scientific community. These include Antarctic collections from surface ice and snow, as well as glacial sediments from the eroded top of nunataks-summits outcropping from the icesheet-and moraines. Collections extracted from deep-sea sediments (DSS) produced a large number of micrometeorites, in particular, iron-rich cosmic spherules that are rarer in other collections. Collections from the old and stable surface of the Atacama Desert show that finding large numbers of micrometeorites is not restricted to polar regions or DSS. The advent of rooftop collections marks an important step into involving citizen science in the study of micrometeorites, as well as providing potential sampling locations over all latitudes to explore the modern flux. We explore their strengths of the collections to address specific scientific questions and their potential weaknesses. The future of micrometeorite research will involve the finding of large fossil micrometeorite collections and benefit from recent advances in sampling cosmic dust directly from the air. This article is part of the theme issue 'Dust in the Solar System and beyond'.

How an intrinsically disordered regulatory subunit assembles a PP1:eIF2 complex.

Fatalska et al.1 use an interdisciplinary strategy to elucidate how an intrinsically disordered regulatory subunit of protein phosphatase 1 binds trimeric eIF2 and positions the phosphatase-substrate complex for dephosphorylation. As validation, they show that a disease mutation abolishes the interaction.

RedOx regulation of LRRK2 kinase activity by active site cysteines.

Mutations of the human leucine-rich repeat kinase 2 (LRRK2) have been associated with both, idiopathic and familial Parkinson's disease (PD). Most of these pathogenic mutations are located in the kinase domain (KD) or GTPase domain of LRRK2. In this study we describe a mechanism in which protein kinase activity can be modulated by reversible oxidation or reduction, involving a unique pair of adjacent cysteines, the "CC" motif. Among all human protein kinases, only LRRK2 contains this "CC" motif (C2024 and C2025) in the Activation Segment (AS) of the kinase domain. In an approach combining site-directed mutagenesis, biochemical analyses, cell-based assays, and Gaussian accelerated Molecular Dynamics (GaMD) simulations we could attribute a role for each of those cysteines. We employed reducing and oxidizing agents with potential clinical relevance to investigate effects on kinase activity and microtubule docking. We find that each cysteine gives a distinct contribution: the first cysteine, C2024, is essential for LRRK2 protein kinase activity, while the adjacent cysteine, C2025, contributes significantly to redox sensitivity. Implementing thiolates (R-S-) in GaMD simulations allowed us to analyse how each of the cysteines in the "CC" motif interacts with its surrounding residues depending on its oxidation state. From our studies we conclude that oxidizing agents can downregulate kinase activity of hyperactive LRRK2 PD mutations and may provide promising tools for therapeutic strategies.

Efficacy and Safety of LetibotulinumtoxinA in the Treatment of Moderate and Severe Glabellar Lines in Females 35 to 50 Years of Age: Post Hoc Analyses of the Phase 3 Clinical Study Data.

Background: Botulinum toxin type A (BoNT-A) injections continue to be widely used as a common treatment for both males and females. According to a recent survey conducted by the International Society of Plastic Aesthetic Surgeons, the majority of patients receiving these injections are females between the ages 35 and 50. Objectives: A post hoc analysis was conducted to examine whether there were variances in the effectiveness and safety of letibotulinumtoxinA for treating vertical glabellar lines between the broader female study population and a particularly defined group of female participants aged 35 to 50. Methods: For this post hoc analysis, data from females aged 35 to 50 were extracted and analyzed from the BLESS III study. In this Phase 3 clinical trial, 355 participants with moderate-to-severe glabella frown lines received either 20 U of letibotulinumtoxinA or a placebo. The study evaluated Glabella Line Severity (GLS) score, treatment onset, duration of effects, time to retreatment, and adverse events. A positive response was determined by achieving a GLS score of 0 or 1, as assessed by both patients and investigators, along with at least a 2-point improvement in GLS score relative to baseline at Week 4 after the injections. Results: Composite responder rates for patients aged 35 to 50 receiving active treatment were significantly higher than for the remaining female population receiving active treatment at Weeks 1, 2, and 4. Females aged 35 to 50 showed higher rates of GLS improvement of ≥1 at Weeks 1, 2, 4, 8, 12, 16, and 20 compared with the remaining female population receiving active treatment. At Week 4, a higher percentage of females aged 35 to 50 achieved a GLS score of 0 upon maximum frowning compared with the remaining females. Females aged 35 to 50 had a shorter median time to onset of GLS improvement compared with the remaining female population. Safety assessments showed a low incidence of treatment-related adverse events in females aged 35 to 50. Conclusions: LetibotulinumtoxinA showed significantly higher response rates in females aged 35 to 50 compared with other female patients at Weeks 1, 2, and 4. Response rates remained higher up to Week 16. The treatment demonstrated efficacy and safety in treating vertical glabellar lines in this patient group.

Molecular determinants and signaling effects of PKA RIα phase separation.

Spatiotemporal regulation of intracellular signaling molecules, such as the 3',5'-cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA), ensures proper cellular function. Liquid-liquid phase separation (LLPS) of the ubiquitous PKA regulatory subunit RIα promotes cAMP compartmentation and signaling specificity. However, the molecular determinants of RIα LLPS remain unclear. Here, we reveal that two separate dimerization interfaces, combined with the cAMP-induced unleashing of the PKA catalytic subunit (PKA-C) from the pseudosubstrate inhibitory sequence, drive RIα condensate formation in the cytosol of mammalian cells, which is antagonized by docking to A-kinase anchoring proteins. Strikingly, we find that the RIα pseudosubstrate region is critically involved in forming a non-canonical R:C complex, which recruits active PKA-C to RIα condensates to maintain low basal PKA activity in the cytosol. Our results suggest that RIα LLPS not only facilitates cAMP compartmentation but also spatially restrains active PKA-C, thus highlighting the functional versatility of biomolecular condensates in driving signaling specificity.

Cosmetic injectables in skin of color: A review of uses, safety, and effectiveness of neuromodulators and dermal fillers.

BACKGROUND: Skin of color (SOC) individuals represent a growing market for cosmetic injectables and can have different aesthetic goals and responses to treatment. OBJECTIVE: A review of the uses, safety, and effectiveness of injectable neuromodulators and dermal fillers in SOC individuals. METHODS AND MATERIALS: A search of the PubMed/MEDLINE database was conducted from August 1960 to December 2020. Studies that were included either had a focus on SOC (>20% SOC study participants) or dedicated article content commenting on the safety and/or efficacy of injectables in SOC participants. RESULTS: Of the 503 publications identified, a total of 88 articles were selected for this review. Differences in aging and cultural factors can influence aesthetic goals amongst SOC populations. Available data suggests that botulinum toxin (BTX) and dermal fillers are safe and effective in SOC populations, with the largest amount of data existing for Asian populations. There remains a paucity of research on Black and Latinx populations. CONCLUSION: BTX and dermal fillers are generally effective and well tolerated in SOC populations, particularly Asian populations for which the greatest amount of data exists. More high quality, randomized controlled trials in Black and Latinx populations are warranted.

LetibotulinumtoxinA Attenuates the Psychological Burden of Glabellar Lines and Is Associated With High Subject Satisfaction in Phase 3 Clinical Trials.

BACKGROUND: Hyperfunctional glabellar frown lines can transmit facial miscues that adversely affect emotional communication, increase perceptions of age, and diminish self-esteem. OBJECTIVE: To evaluate the efficacy of letibotulinumtoxinA in mitigating the negative psychological impact associated with moderate to severe glabellar lines and to assess subject satisfaction with treatment outcome in the BLESS phase 3 clinical trials. MATERIALS AND METHODS: Baseline and posttreatment assessments were made using validated subject-administered instruments: Modified Skindex-16 Glabellar Line Quality of Life (GL-QoL) Scale, Facial Assessment and Cosmetic Evaluation Questionnaire (FACE-Q) Appraisal of Lines Between Eyebrows Scale, FACE-Q Age Appraisal Visual Analog Scale, and FACE-Q Satisfaction with Outcome Scale. An integrated analysis using pooled BLESS data was conducted on these secondary end points. RESULTS: Among enrolled and treated subjects ( N = 1,272), 85.5% had moderate to severe psychological impact at baseline. LetibotulinumtoxinA subjects experienced significant improvements compared with placebo on all measures. Mean improvement to Week 4 for the Modified Skindex-16 GL-QoL Scale overall score was -33.84 for letibotulinumtoxinA subjects compared with -1.37 for placebo subjects ( p < .001). Attenuation of psychological burden was highly correlated with improvement in glabellar line severity ( p < .0001). CONCLUSION: LetibotulinumtoxinA significantly improved the psychosocial burden associated with glabellar lines across all trials. Treated subjects experienced improved quality of life, younger perceived age, and satisfaction with treatment outcome.

Unusual imaging findings associated with abdominal pediatric germ cell tumors.

Germ cell tumors of childhood are tumors arising from germline cells in gonadal or extragonadal locations. Extragonadal germ cell tumors are characteristically located in the midline, arising intracranially or in the mediastinum, retroperitoneum, or pelvis. These tumors are generally easily diagnosed due to typical sites of origin, characteristic imaging findings, and laboratory markers. However, germ cell tumors can be associated with unusual clinical syndromes or imaging features that can perplex the radiologist. This review will illustrate atypical imaging/clinical manifestations and complications of abdominal germ cell tumors in childhood. These features include unusual primary tumors such as multifocal primaries; local complications such as ovarian torsion or ruptured dermoid; atypical presentations of metastatic disease associated with burned-out primary tumor, growing teratoma syndrome, and gliomatosis peritonei; endocrine manifestations such as precocious puberty and hyperthyroidism; and antibody mediated paraneoplastic syndrome such as anti-N-methyl-D-aspartate-receptor antibody-mediated encephalitis. This review aims to illustrate unusual imaging features associated with the primary tumor, metastatic disease, or distant complications of abdominal germ cell tumors of childhood.