Multimodal evaluation of blood-brain barrier opening in mice in response to low-intensity ultrasound and a claudin-5 binder.

Background: The blood-brain barrier (BBB) is a major bottleneck in delivering therapeutics to the brain. Treatment strategies to transiently open this barrier include focused ultrasound combined with intravenously injected microbubbles (FUS+MB) and targeting of molecules that regulate BBB permeability. Methods: Here, we investigated BBB opening mediated by the claudin-5 binder cCPEm (a microorganismal toxin in a truncated form) and FUS+MB at a centre frequency of 1 MHz, assessing dextran uptake, broadband emission, and endogenous immunoglobulin G (IgG) extravasation. Results: FUS+MB-induced BBB opening was detectable at a pressure ≥0.35 MPa when assessed for leakage of 10 and 70 kDa dextran, and at ≥0.2 MPa for uptake of endogenous IgG. Treating mice with 20 mg/kg cCPEm failed to open the BBB, and pre-treatment with cCPEm followed by FUS+MB at 0.2 and 0.3 MPa did not overtly increase BBB opening compared to FUS+MB alone. Using passive cavitation detection (PCD), we found that broadband emission correlated with the peak negative pressure (PNP) and dextran leakage, indicating the possibility of using broadband emission for developing a feedback controller to monitor BBB opening. Conclusions: Together, our study highlights the challenges in developing combinatorial approaches to open the BBB and presents an additional IgG-based histological detection method for BBB opening.

Kismet/CHD7/CHD8 affects gut microbiota, mechanics, and the gut-brain axis in Drosophila melanogaster.

The gut microbiome affects brain and neuronal development and may contribute to the pathophysiology of neurodevelopmental disorders. However, it is unclear how risk genes associated with such disorders affect gut physiology in a manner that could impact microbial colonization and how the mechanical properties of the gut tissue might play a role in gut-brain bidirectional communication. To address this, we used Drosophila melanogaster with a null mutation in the gene kismet, an ortholog of chromodomain helicase DNA-binding protein (CHD) family members CHD7 and CHD8. In humans, these are risk genes for neurodevelopmental disorders with co-occurring gastrointestinal symptoms. We found that kismet mutant flies have a significant increase in gastrointestinal transit time, indicating the functional homology of kismet with CHD7/CHD8 in vertebrates. Rheological characterization of dissected gut tissue revealed significant changes in the mechanics of kismet mutant gut elasticity, strain stiffening behavior, and tensile strength. Using 16S rRNA metagenomic sequencing, we also found that kismet mutants have reduced diversity and abundance of gut microbiota at every taxonomic level. To investigate the connection between the gut microbiome and behavior, we depleted gut microbiota in kismet mutant and control flies and quantified the flies' courtship behavior. Depletion of gut microbiota rescued courtship defects of kismet mutant flies, indicating a connection between gut microbiota and behavior. In striking contrast, depletion of the gut microbiome in the control strain reduced courtship activity, demonstrating that antibiotic treatment can have differential impacts on behavior and may depend on the status of microbial dysbiosis in the gut prior to depletion. We propose that Kismet influences multiple gastrointestinal phenotypes that contribute to the gut-microbiome-brain axis to influence behavior. We also suggest that gut tissue mechanics should be considered as an element in the gut-brain communication loop, both influenced by and potentially influencing the gut microbiome and neurodevelopment.

Ocular Dirofilariasis: A Clinicopathologic Case Series and Literature Review.

Purpose: Ocular dirofilariasis is an uncommon zoonotic infection that is usually associated with a carnivore host. In this case series and literature review, we investigate the clinical presentation, management, and histopathology of ocular dirofilariasis. Methods: The database at the Florida Lions Ocular Pathology Laboratory was searched for surgical specimens at the Bascom Palmer Eye Institute under approval of the Institutional Review Board. Patients with a histopathologic diagnosis of dirofilariasis between the years 1962 and 2022 from the Florida Lions Ocular Pathology Laboratory database were included (n = 3). A systematic PubMed search was conducted by two independent authors to identify published cases of ophthalmic dirofilariasis worldwide. Keywords were used to identify articles, and exclusion criteria were applied. Results: Three patients, two males and one female, were identified from the Florida Lions Ocular Pathology Laboratory database with a diagnosis of ocular dirofilariasis. The mean age was 46.7 years (with a range 33-57 years). There were two eyelid lesions (Cases 1 and 3) and one involving the subconjunctival space (Case 2). All three organisms were excised and presumptively identified as Dirofilaria tenuis. All 3 patients were managed with curative surgical removal and recovered completely. Our review of the literature identified 540 published reports and 142 published reports with 186 cases that met the exclusion criteria. Conclusion: We present a case series and literature review of ocular dirofilariasis. Knowledge of the incidence, risk factors, prevention, and diagnosis of this unique parasitic infection will help in proper management and prevent further ocular complications.

Counterproductive effects of anti-CD38 and checkpoint inhibitor for the treatment of NK/T cell lymphoma.

Introduction: Natural killer/T cell lymphoma (NKTL) is an aggressive malignancy associated with poor prognosis. This is largely due to limited treatment options, especially for relapsed patients. Immunotherapies like immune checkpoint inhibitors (ICI) and anti-CD38 therapies have shown promising but variable clinical efficacies. Combining these therapies has been suggested to enhance efficacy. Methods: We conducted a case study on a relapsed NKTL patient treated sequentially with anti-CD38 followed by ICI (anti-PD1) using cytometry analyses. Results and Discussion: Our analysis showed an expected depletion of peripheral CD38+ B cells following anti-CD38 treatment. Further analysis indicated that circulating anti-CD38 retained their function for up to 13 weeks post-administration. Anti-PD1 treatment triggered re-activation and upregulation of CD38 on the T cells. Consequently, these anti-PD1-activated T cells were depleted by residual circulating anti-CD38, rendering the ICI treatment ineffective. Finally, a meta-analysis confirmed this counterproductive effect, showing a reduced efficacy in patients undergoing combination therapy. In conclusion, our findings demonstrate that sequential anti-CD38 followed by anti-PD1 therapy leads to a counterproductive outcome in NKTL patients. This suggests that the treatment sequence is antithetic and warrants re-evaluation for optimizing cancer immunotherapy strategies.

Interleukin-15 is a hair follicle immune privilege guardian.

The autoimmunity-promoting cytokine, Interleukin-15 (IL-15), is often claimed to be a key pathogenic cytokine in alopecia areata (AA). Yet, rhIL-15 promotes human hair follicle (HF) growth ex vivo. We have asked whether the expression of IL-15 and its receptor (IL-15R) isoforms is altered in human AA and how IL-15 impacts on human HF immune privilege (HF-IP) in the presence/absence of interferon-γ (IFNγ), the well-documented key AA-pathogenic cytokine, as well as on hair regrowth after experimental AA induction in vivo. Quantitative immunohistomorphometry showed the number of perifollicular IL-15+ T cells in AA skin biopsies to be significantly increased compared to healthy control skin, while IL-15, IL-15Rα, and IL-15Rγ protein expression within the hair bulb were significantly down-regulated in AA HFs. In organ-cultured human scalp HFs, rhIL-15 significantly reduced hair bulb expression of MICA, the key "danger" signal in AA pathogenesis, and increased production of the HF-IP guardian, α-MSH. Crucially, ex vivo, rhIL-15 prevented IFNγ-induced HF-IP collapse, restored a collapsed HF-IP by IL-15Rα-dependent signaling (as documented by IL-15Rα-silencing), and protected AA-preventive immunoinhibitory iNKT10 cells from IFNγ-induced apoptosis. rhIL-15 even promoted hair regrowth after experimental AA induction in human scalp skin xenotransplants on SCID/beige mice in vivo. Our data introduce IL-15 as a novel, functionally important HF-IP guardian whose signaling is constitutively defective in scalp HFs of AA patients. Our data suggest that selective stimulation of intrafollicular IL-15Rα signaling could become a novel therapeutic approach in AA management, while blocking it pharmacologically may hinder both HF-IP restoration and hair re-growth and may thus make HFs more vulnerable to AA relapse.

Beyond the Surface: A Systematic Review of Perforating and Penetrating Globe Injuries From Blepharoplasty.

PURPOSE: This study aims to address the infrequent but serious complication of globe injuries in blepharoplasty. METHODS: A case series of 3 patients with globe injuries postblepharoplasty is presented, along with a systematic literature review that revealed 13 previously reported cases. Quantitative and comparative analysis is described. RESULTS: Injuries ranged from deep thermal burns to full-thickness corneal or scleral lacerations, with one instance of traumatic cataract. The median time from surgery to symptom onset was 1 day, with a concerning median delay of 7 days to presentation to an ophthalmologist. Visual outcomes were generally poor, with nearly all patients experiencing permanent visual morbidity. The systematic review revealed 3 cases of endophthalmitis following perforating scleral injuries. Comparative analysis showed no significant differences in visual outcomes between penetrating and perforating injuries. CONCLUSIONS: The findings of this study emphasize the need for increased vigilance for globe injuries that require prompt ophthalmological evaluation following blepharoplasty, especially considering the observed delay in presentation and the extent of visual morbidity. The study advocates for improved practitioner training in recognizing and managing these complications and underscores the importance of patient education regarding the potential risks and the necessity of timely postoperative care.

Bisphenol F affects neurodevelopmental gene expression, mushroom body development, and behavior in Drosophila melanogaster.

Bisphenol F (BPF) is a potential neurotoxicant used as a replacement for bisphenol A (BPA) in polycarbonate plastics and epoxy resins. We investigated the neurodevelopmental impacts of BPF exposure using Drosophila melanogaster as a model. Our transcriptomic analysis indicated that developmental exposure to BPF caused the downregulation of neurodevelopmentally relevant genes, including those associated with synapse formation and neuronal projection. To investigate the functional outcome of BPF exposure, we evaluated neurodevelopmental impacts across two genetic strains of Drosophila- w1118 (control) and the Fragile X Syndrome (FXS) model-by examining both behavioral and neuronal phenotypes. We found that BPF exposure in w1118 Drosophila caused hypoactive larval locomotor activity, decreased time spent grooming by adults, reduced courtship activity, and increased the severity but not frequency of ß-lobe midline crossing defects by axons in the mushroom body. In contrast, although BPF reduced peristaltic contractions in FXS larvae, it had no impact on other larval locomotor phenotypes, grooming activity, or courtship activity. Strikingly, BPF exposure reduced both the severity and frequency of ß-lobe midline crossing defects in the mushroom body of FXS flies, a phenotype previously observed in FXS flies exposed to BPA. This data indicates that BPF can affect neurodevelopment and its impacts vary depending on genetic background. Further, BPF may elicit a gene-environment interaction with Drosophila fragile X messenger ribonucleoprotein 1 (dFmr1)-the ortholog of human FMR1, which causes fragile X syndrome and is the most common monogenetic cause of intellectual disability and autism spectrum disorder.

Harmonizing florbetapir and PiB PET measurements of cortical Aß plaque burden using multiple regions-of-interest and machine learning techniques: An alternative to the Centiloid approach.

INTRODUCTION: Machine learning (ML) can optimize amyloid (Aß) comparability among positron emission tomography (PET) radiotracers. Using multi-regional florbetapir (FBP) measures and ML, we report better Pittsburgh compound-B (PiB)/FBP harmonization of mean-cortical Aß (mcAß) than Centiloid. METHODS: PiB-FBP pairs from 92 subjects in www.oasis-brains.org and 46 in www.gaain.org/centiloid-project were used as the training/testing sets. FreeSurfer-extracted FBP multi-regional Aß and actual PiB mcAß in the training set were used to train ML models generating synthetic PiB mcAß. The correlation coefficient (R) between the synthetic/actual PiB mcAß in the testing set was assessed. RESULTS: In the testing set, the synthetic/actual PiB mcAß correlation R = 0.985 (R2  = 0.970) using artificial neural network was significantly higher (p ≤ 6.6e-4) than the FBP/PiB correlation R = 0.927 (R2  = 0.860), improving total variance percentage (R2 ) from 86% to 97%. Other ML models such as partial least square, ensemble, and relevance vector regressions also improved R (p = 9.677e-05 /0.045/0.0017). DISCUSSION: ML improved mcAß comparability. Additional studies are needed for the generalizability to other amyloid tracers, and to tau PET. Highlights Centiloid is a calibration of the amyloid scale, not harmonization. Centiloid unifies the amyloid scale without improving inter-tracer association (R2 ). Machine learning (ML) can harmonize the amyloid scale by improving R2 . ML harmonization maps multi-regional florbetapir SUVRs to PiB mean-cortical SUVR. Artificial neural network ML increases Centiloid R2 from 86% to 97%.

Synthesis, characterization and differentiation of the structural isomers of valine and tert-leucine derived synthetic cannabinoids.

The identification of the synthetic cannabinoids receptor agonists (SCRAs) has always posed a great challenge to drug testing laboratories with slight structural modifications aimed at evading drug legislation. In addition, the most prevalent synthetic cannabinoids have valine and tert-leucine amino acid moieties where re-arrangement of the carbon chains can result in structural isomers that are very similar to the parent synthetic cannabinoids. This makes their analysis and identification challenging, and the problem is compounded with the difficulty in purchasing reference standards quickly and a lack of literature for comparison. Therefore, in this investigation, four series of synthetic cannabinoids (AB-PINACA, AB-CHMINACA, MMB-FUBINACA and 5-fluoro-MDMB-PINACA) and their alkyl chain structural isomers at the amino acid moieties were synthesized and characterized using various analytical techniques-gas chromatography-mass spectrometry (GC-MS), gas chromatography-infrared detection (GC-IRD) and nuclear magnetic resonance (NMR) spectroscopy to evaluate the ability of each analytical technique to differentiate the respective isomers for their identification. A total of 12 isomers were synthesized and analysed together with the four parent synthetic cannabinoids. NMR was able to differentiate between all the compounds, whereas GC-IRD was able to discern between most of the synthetic cannabinoids and their isomers. GC-MS had the least discriminating power and was not able to differentiate some of the compounds that has very similar mass spectra. The results from this work will be useful to other drug testing laboratories that are facing the identification of related synthetic cannabinoids.

The Platysma Contraction Pattern in Healthy Adults: A Vector Analysis Study.

BACKGROUND: The platysma muscle's role in lower face dynamics is complex. Multiple insertion points to soft-tissue structures at various levels in the lower face create a multifaceted contraction pattern. To avoid adverse effects in cosmetic procedures when targeting the platysma, its anatomy and physiology must be understood. Clinical observations hint at a bidirectional contraction pattern. METHODS: Eighteen healthy volunteers (13 women and five men) with a mean age of 44.2 ± 10.1 years were enrolled. Skin displacement vector analysis was used on maximal platysma contraction to characterize and calculate the movement of the neck and lower face skin. RESULTS: In all of the participants, a bidirectional movement of the skin was observed: the skin of the lower face and inferior to the jawline moved caudally, whereas the skin of the lower neck moved cephalad. Both movements converged at a line situated at 54% ± 10% and 55% ± 8% of the length between the clavicle and the inferior base of the ear lobe in men and women, respectively ( P = 0.70). CONCLUSIONS: The platysma is a bidirectional muscle with a line of convergence. Whereas the superior portion acts as lip depressor, the lower portion elevates the skin of the upper chest and lower neck. This transition can explain some of the clinically observed adverse effects of neuromodulation of the neck area. It can potentially direct neuromodulation injections to focus above the convergence line to better address lower face descent.

Response of 21 Hyaluronic Acid Fillers to Recombinant Human Hyaluronidase.

Background: One benefit of hyaluronic acid fillers is the ability to dissolve them using hyaluronidase. With the increasing number of fillers entering the market, it is crucial to understand each of these fillers' responsiveness to hyaluronidase. Methods: Twenty-one hyaluronic acid fillers of 0.2 mL aliquots each were placed on slides. Twenty units of recombinant human hyaluronidase were injected into the aliquots every 30 minutes for a total of 120 units recombinant human hyaluronidase injected over 3 hours. With each injection, videos and photographs were taken from bird's eye and lateral views to measure aliquot height. Stirring videos were graded by three oculoplastic surgeons, and these grades were used to categorize each filler's responsiveness. Results: Restylane Lyft, Restylane-L/Eyelight, and Resilient Hyaluronic Acid (RHA) 1/Redensity were the least resistant. The moderately resistant group comprised of Restylane Silk, Juvéderm Volbella, Revanesse Versa/Lips, and Belotero Balance on the less resistant side to Juvéderm Vollure, RHA 2, Restylane Contour, Juvéderm Ultra, Restylane Refyne, Belotero Intense, Restylane Kysse, RHA 3, Juvéderm Ultra Plus, and Restylane Defyne on the more resistant side. The most resistant were RHA 4, Juvéderm Voluma, Belotero Volume, and Juvéderm Volux. The most resistant fillers required 120 units of hyaluronidase per 0.2 mL filler to dissolve. Conclusions: With the increasing popularity of fillers comes the increasing need to dissolve them for both ischemic and nonischemic complications. The majority of hyaluronic acid fillers available on the market are very resistant to hyaluronidase, which must be considered when determining the amount of hyaluronidase to dissolve a particular filler.

Melatonin Exerts Prominent, Differential Epidermal and Dermal Anti-Aging Properties in Aged Human Eyelid Skin Ex Vivo.

Human skin aging is associated with functional deterioration on multiple levels of physiology, necessitating the development of effective skin senotherapeutics. The well-tolerated neurohormone melatonin unfolds anti-aging properties in vitro and in vivo, but it remains unclear whether these effects translate to aged human skin ex vivo. We tested this in organ-cultured, full-thickness human eyelid skin (5-6 donors; 49-77 years) by adding melatonin to the culture medium, followed by the assessment of core aging biomarkers via quantitative immunohistochemistry. Over 6 days, 200 µM melatonin significantly downregulated the intraepidermal activity of the aging-promoting mTORC1 pathway (as visualized by reduced S6 phosphorylation) and MMP-1 protein expression in the epidermis compared to vehicle-treated control skin. Conversely, the transmembrane collagen 17A1, a key stem cell niche matrix molecule that declines with aging, and mitochondrial markers (e.g., TFAM, MTCO-1, and VDAC/porin) were significantly upregulated. Interestingly, 100 µM melatonin also significantly increased the epidermal expression of VEGF-A protein, which is required and sufficient for inducing human skin rejuvenation. In aged human dermis, melatonin significantly increased fibrillin-1 protein expression and improved fibrillin structural organization, indicating an improved collagen and elastic fiber network. In contrast, other key aging biomarkers (SIRT-1, lamin-B1, p16INK4, collagen I) remained unchanged. This ex vivo study provides proof of principle that melatonin indeed exerts long-suspected but never conclusively demonstrated and surprisingly differential anti-aging effects in aged human epidermis and dermis.

Teprotumumab for the Treatment of Recalcitrant Thyroid Eye Disease.

PURPOSE: Teprotumumab, an insulin-like growth factor 1 receptor monoclonal antibody, is FDA-approved to treat thyroid eye disease (TED). The initial clinical trials excluded patients with previous orbital irradiation, surgery, glucocorticoid use (cumulative dose >1 gm), or prior biologic treatment. Information on the use of teprotumumab for patients who failed prior therapy is limited. Our purpose is to characterize the efficacy of teprotumumab for the treatment of recalcitrant TED. METHODS: This is a multicenter retrospective study of all patients treated with teprotumumab for moderate-to-severe TED after failing conventional therapy with corticosteroids, orbital radiation, surgical decompression, biologics, or other steroid-sparing medications. Treatment failure was defined as an incomplete response to or reactivation after previous treatment. Only patients who received at least 4 infusions of teprotumumab were included in the analysis. Primary outcome measures comprised proptosis response (≥2 mm reduction in the study eye without a similar increase in the other eye), clinical activity score (CAS) response (≥2-point reduction in CAS), and diplopia response (≥1 point improvement in Gorman diplopia score in patients with baseline diplopia) following treatment. Adverse events and risk factors for recalcitrant disease were also evaluated. RESULTS: Sixty-six patients were included in this study, 46 females and 20 males. Average age was 59.3 years (range 29-93). The mean duration of disease from TED diagnosis to first infusion was 57.8 months. The proptosis, CAS, and diplopia responses in this recalcitrant patient population were 85.9%, 93.8%, and 69.1%, respectively. Patients experienced a mean reduction in proptosis of 3.1 ± 2.4 mm and a mean improvement in CAS of 3.8 ± 1.6. Patients who underwent prior decompression surgery experienced a statistically significant decrease in diplopia response (46.7% vs. 77.5%, p = 0.014) and proptosis response (75.0% vs. 90.9%, p = 0.045) when compared with nondecompression patients. Additionally, there were no significant differences in proptosis, CAS, and diplopia responses between patients with acute (defined as disease duration <1 year) versus chronic (disease duration ≥1 year) TED. While most adverse events were mild to moderate, 4 patients reported serious adverse events related to persistent hearing loss. CONCLUSIONS: Patients with recalcitrant TED demonstrated a significant improvement after teprotumumab in each of the primary study outcomes. The degree of proptosis reduction, diplopia response, and CAS improvement in the recalcitrant group were similar to those of treatment-naïve patients from the pivotal clinical trials. Patients with a prior history of orbital decompression, however, demonstrated poor improvement in diplopia and less reduction in proptosis than surgery naïve patients. These results indicate that teprotumumab is a treatment option for the treatment of patients with TED recalcitrant to prior medical therapies.

Prevalence of Body Dysmorphic Disorder in Orbital Plastic Surgery and Its Relationship with the Use of Social Media.

BACKGROUND: The prevalence of body dysmorphic disorder (BDD) in the general population ranges from 0.7 to 2.4%; however, higher rates are seen among aesthetic patients. Given the recent rise in popularity of cosmetic surgery, particularly in the post-COVID pandemic setting, the authors hypothesize the prevalence has increased. The purpose of the study is to examine the prevalence of BDD in patients presenting to an oculoplastic surgery clinic at an academic center and determine correlation with social media use. METHODS: This is a survey of patients presenting to the oculoplastic surgery clinic. Participants completed the Dysmorphic Concern Questionnaire (DCQ), in addition to survey questions about social media use. Main outcomes included a positive screen and social media use. RESULTS: A total of 175 patients that presented to the oculoplastic and reconstructive surgery clinic were surveyed. All patients, including cosmetic, functional, and non-surgical, were offered participation in the survey. 9.13% of all patients screened positive for BDD. Patients that screened positive were more commonly female (71.43%). The distribution of patients with BDD was even between Hispanics (52.38%) and non-Hispanics, and 85.71% of patients with BDD were Caucasian. Of patients that screened positive, 71.43% use social media. CONCLUSIONS: The prevalence of BDD may have increased in the past seven years and is seen most in females and Caucasians. There is a positive correlation with social media, which has increased in popularity since the COVID-19 pandemic. It is important to maintain a high clinical suspicion for BDD and consider screening if there is concern. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

An allosteric pan-TEAD inhibitor blocks oncogenic YAP/TAZ signaling and overcomes KRAS G12C inhibitor resistance.

The Hippo pathway is a key growth control pathway that is conserved across species. The downstream effectors of the Hippo pathway, YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif), are frequently activated in cancers to drive proliferation and survival. Based on the premise that sustained interactions between YAP/TAZ and TEADs (transcriptional enhanced associate domain) are central to their transcriptional activities, we discovered a potent small-molecule inhibitor (SMI), GNE-7883, that allosterically blocks the interactions between YAP/TAZ and all human TEAD paralogs through binding to the TEAD lipid pocket. GNE-7883 effectively reduces chromatin accessibility specifically at TEAD motifs, suppresses cell proliferation in a variety of cell line models and achieves strong antitumor efficacy in vivo. Furthermore, we uncovered that GNE-7883 effectively overcomes both intrinsic and acquired resistance to KRAS (Kirsten rat sarcoma viral oncogene homolog) G12C inhibitors in diverse preclinical models through the inhibition of YAP/TAZ activation. Taken together, this work demonstrates the activities of TEAD SMIs in YAP/TAZ-dependent cancers and highlights their potential broad applications in precision oncology and therapy resistance.

Plasma NfL is associated with the APOE ε4 allele, brain imaging measurements of neurodegeneration, and lower recall memory scores in cognitively unimpaired late-middle-aged and older adults.

BACKGROUND: Plasma neurofilament light (NfL) is an indicator of neurodegeneration and/or neuroaxonal injury in persons with Alzheimer's disease (AD) and a wide range of other neurological disorders. Here, we characterized and compared plasma NfL concentrations in cognitively unimpaired (CU) late-middle-aged and older adults with two, one, or no copies of the APOE ε4 allele, the major genetic risk factor for AD. We then assessed plasma NfL associations with brain imaging measurements of AD-related neurodegeneration (hippocampal atrophy and a hypometabolic convergence index [HCI]), brain imaging measurements of amyloid-ß plaque burden, tau tangle burden and white matter hyperintensity volume (WMHV), and delayed and total recall memory scores. METHODS: Plasma NfL concentrations were measured in 543 CU 69 ± 9 year-old participants in the Arizona APOE Cohort Study, including 66 APOE ε4 homozygotes (HM), 165 heterozygotes (HT), and 312 non-carriers (NC). Robust regression models were used to characterize plasma NfL associations with APOE ε4 allelic dose before and after adjustment for age, sex, and education. They were also used to characterize plasma NfL associations with MRI-based hippocampal volume and WMHV measurements, an FDG PET-based HCI, mean cortical PiB PET measurements of amyloid-ß plaque burden and meta-region-of-interest (meta-ROI) flortaucipir PET measurements of tau tangle burden, and Auditory Verbal Learning Test (AVLT) Delayed and Total Recall Memory scores. RESULTS: After the adjustments noted above, plasma NfL levels were significantly greater in APOE ε4 homozygotes and heterozygotes than non-carriers and significantly associated with smaller hippocampal volumes (r = - 0.43), greater tangle burden in the entorhinal cortex and inferior temporal lobes (r = 0.49, r = 0.52, respectively), and lower delayed (r = - 0.27), and total (r = - 0.27) recall memory scores (p < 0.001). NfL levels were not significantly associated with PET measurements of amyloid-ß plaque or total tangle burden. CONCLUSIONS: Plasma NfL concentrations are associated with the APOE ε4 allele, brain imaging biomarkers of neurodegeneration, and less good recall memory in CU late-middle-aged and older adults, supporting its value as an indicator of neurodegeneration in the preclinical study of AD.

The development of a parent report instrument of early communication and language skills of infants and toddlers in mainland China.

OBJECTIVE: This study was designed to produce a new parent-report measure, the Diagnostic Receptive Expressive Assessment of Mandarin-Infant Toddler Assessment of Communication and Language (DREAM-IT) in order to provide norms for the developmental skills of children aged 0-36 months in four areas: expressive language, receptive language, cognitive play and social skills. METHODOLOGY: The scale was designed to be both broader and deeper than existing instruments that neglect one or more of these significant domains involved in early language. Items were chosen by a group of specialists with clinical experience working with the age group and with attention to the developmental literature. Caregivers were tested individually by a trained person who asked the questions and provided examples. In addition to an extensive health questionnaire, caregivers answered questions in Mandarin about their child's behaviour using a scale of 'not yet', 'sometimes' or 'always' or listing out words and/or sounds understood or said by the child. The 476 participating caregivers were recruited at maternal and child healthcare clinics centred in Chengdu, China, 191 of whom were tested a second time seven months later. The children were sampled in three-month age-bands from 0 to 36 months. The sample was balanced for child gender by age band, and parental education was balanced. Caregivers of 0-24-month-old children and caregivers of 12-36 months were each asked a different set of questions, to determine the appropriate age range and cutoff points for each question, requiring the sample size to be doubled for children aged 12-24 months. RESULTS: The results were subject to item-response theory analysis to remove outlying items, and the resulting internal reliability was high for each domain (average Cronbach's alpha=0.87). The final instrument (between 67 and 113 questions in total) was refined to include the least redundant questions that had the highest intercorrelations, with attention paid to coverage of all domains across the age range. Two scales were developed: one for children 0-18 months, the second for children aged 18-36 months. The longitudinal design permitted the creation of growth curves and norms for each domain for six-month intervals from 0 to 36 months. A small sample of 32 parents of children with Down syndrome aged 18-36 months provided validation that the scales are highly sensitive to developmental delay. CONCLUSION: The instrument shows considerable promise for detecting early communication problems in children in China. WHAT THIS PAPER ADDS: What is already known on the subject In China, efforts were made in recent years to develop language assessments for infants and toddlers, but limitations existed with the domains included and number of items included per age group. Many clinical practitioners also continued to rely on language subtests of general developmental scales, which were limited in depth and breadth of language skills tested and were never intended for diagnosis of language delay. What this paper adds to existing knowledge This paper discusses the development of a valid caregiver report instrument for early communication and language skills of infants and toddlers in mainland China. The Diagnostic Receptive Expressive Assessment of Mandarin-Infant Toddler (DREAM-IT) includes foundational domains necessary for language and communication development in young children (receptive language, expressive language, cognitive play and social communication domains). The results show strong internal reliability (Cronbach's alpha) for each domain on a sample of 716 children sampled in three-month age bands from 0 to 36 months. The external validity proved strong when tested on a group of 32 young children with Down syndrome. What are the potential or actual clinical implications of this work? Besides helping to inform the diagnosis of language delays in infants and toddlers in China, the caregiver report instrument has special features to support clinical practitioners in a field that is just emerging in China. The unique support features include the automatic generation of a profile of relative strengths and weaknesses of the child on the report and the recommendation of child-specific caregiver coaching videos on a companion app.

Dedifferentiation maintains melanocyte stem cells in a dynamic niche.

For unknow reasons, the melanocyte stem cell (McSC) system fails earlier than other adult stem cell populations1, which leads to hair greying in most humans and mice2,3. Current dogma states that McSCs are reserved in an undifferentiated state in the hair follicle niche, physically segregated from differentiated progeny that migrate away following cues of regenerative stimuli4-8. Here we show that most McSCs toggle between transit-amplifying and stem cell states for both self-renewal and generation of mature progeny, a mechanism fundamentally distinct from those of other self-renewing systems. Live imaging and single-cell RNA sequencing revealed that McSCs are mobile, translocating between hair follicle stem cell and transit-amplifying compartments where they reversibly enter distinct differentiation states governed by local microenvironmental cues (for example, WNT). Long-term lineage tracing demonstrated that the McSC system is maintained by reverted McSCs rather than by reserved stem cells inherently exempt from reversible changes. During ageing, there is accumulation of stranded McSCs that do not contribute to the regeneration of melanocyte progeny. These results identify a new model whereby dedifferentiation is integral to homeostatic stem cell maintenance and suggest that modulating McSC mobility may represent a new approach for the prevention of hair greying.

Mass Balance of the Indoleamine 2,3-Dioxygenase Inhibitor Navoximod (GDC-0919) in Rats and Dogs: Unexpected Cyanide Release from Imidazo[5,1-a]isoindole and Species Differences in Glucuronidation.

Navoximod (GDC-0919) is a small molecule inhibitor of indoleamine 2,3-dioxygenase 1 (IDO1) developed to reduce T cell immunosuppression associated with cancer. This study describes the absorption, metabolism, and excretion (AME) of navoximod in rats and dogs after a single oral dose of [14C]-navoximod. An unexpected thiocyanate metabolite M1 and a chiral inversion metabolite M51 were captured as the major circulating metabolites in rats, accounting for 30% and 18% of 0-24 hours exposure, respectively. These two metabolites combined had much lower systemic exposure in dogs and humans (<6% and <1%). The novel cyanide release is proposed to occur via 4,5-epoxidation on the fused imidazole ring, leading to ring opening and rearrangement along with the release of cyanide. The decyanated metabolites were identified and confirmed by synthetic standards, which supported the proposed mechanism. In dogs, glucuronidation to M19 was the major clearance mechanism, representing 59% of the dose in the bile of bile duct-cannulated (BDC) dogs and 19% of the dose in the urine of intact dogs. Additionally, M19 also represented 52% of drug related exposure in circulation in dogs. In comparison, in humans, navoximod was mainly cleared through glucuronidation to M28 and excreted in urine (60% of the dose). The differences in the metabolism and elimination observed in vivo were qualitatively recapitulated in vitro with liver microsomes, suspended hepatocytes, and cocultured primary hepatocytes. The striking species differences in regioselective glucuronidation is likely explained by the species differences in UGT1A9, which was mainly responsible for M28 formation in humans. SIGNIFICANCE STATEMENT: The results from this study demonstrated significant species differences in metabolism (especially glucuronidation) and elimination of navoximod among rats, dogs, and humans. The study also illustrated the mechanism of a novel cyanide release metabolism from the fused imidazo[5,1-a]isoindole ring. Such biotransformation should be kept in mind when working with imidazole-containing new chemical entities in drug discovery and development.