CCR5 closes the temporal window for memory linking.

Real-world memories are formed in a particular context and are often not acquired or recalled in isolation1-5. Time is a key variable in the organization of memories, as events that are experienced close in time are more likely to be meaningfully associated, whereas those that are experienced with a longer interval are not1-4. How the brain segregates events that are temporally distinct is unclear. Here we show that a delayed (12-24 h) increase in the expression of C-C chemokine receptor type 5 (CCR5)-an immune receptor that is well known as a co-receptor for HIV infection6,7-after the formation of a contextual memory determines the duration of the temporal window for associating or linking that memory with subsequent memories. This delayed expression of CCR5 in mouse dorsal CA1 neurons results in a decrease in neuronal excitability, which in turn negatively regulates neuronal memory allocation, thus reducing the overlap between dorsal CA1 memory ensembles. Lowering this overlap affects the ability of one memory to trigger the recall of the other, and therefore closes the temporal window for memory linking. Our findings also show that an age-related increase in the neuronal expression of CCR5 and its ligand CCL5 leads to impairments in memory linking in aged mice, which could be reversed with a Ccr5 knockout and a drug approved by the US Food and Drug Administration (FDA) that inhibits this receptor, a result with clinical implications. Altogether, the findings reported here provide insights into the molecular and cellular mechanisms that shape the temporal window for memory linking.

A statistical method for image-mediated association studies discovers genes and pathways associated with four brain disorders.

Brain imaging and genomics are critical tools enabling characterization of the genetic basis of brain disorders. However, imaging large cohorts is expensive and may be unavailable for legacy datasets used for genome-wide association studies (GWASs). Using an integrated feature selection/aggregation model, we developed an image-mediated association study (IMAS), which utilizes borrowed imaging/genomics data to conduct association mapping in legacy GWAS cohorts. By leveraging the UK Biobank image-derived phenotypes (IDPs), the IMAS discovered genetic bases underlying four neuropsychiatric disorders and verified them by analyzing annotations, pathways, and expression quantitative trait loci (eQTLs). A cerebellar-mediated mechanism was identified to be common to the four disorders. Simulations show that, if the goal is identifying genetic risk, our IMAS is more powerful than a hypothetical protocol in which the imaging results were available in the GWAS dataset. This implies the feasibility of reanalyzing legacy GWAS datasets without conducting additional imaging, yielding cost savings for integrated analysis of genetics and imaging.

Trends in Sexually Transmitted Infections Associated with the Doxycycline Post-Exposure Prophylaxis Guidelines in San Francisco.

ABSTRACT: The San Francisco Department of Public Health was the first to issue guidance on the use of doxycycline for post-exposure prophylaxis against STIs in at-risk populations. We investigated the association between the issuance of these guidelines and rates of male rectal chlamydia, male rectal gonorrhea, and adult male syphilis.

New Pathways in Syphilis Vaccine Development.

ABSTRACT: The New Pathways in Syphilis Vaccine Development meeting was held prior to the start of the STI & HIV 2023 World Congress as a pre-meeting symposium to highlight recent advances in the development of an effective syphilis vaccine and discuss the challenges still faced by investigators. Internationally renowned public health officials, clinical investigators, and basic researchers from academia, government, and community-based organizations met on the 24 th of July 2023 in Chicago, Illinois. Four speakers discussed key research findings in syphilis vaccine development, which included antigen selection, identification of epitopes associated with protective immunity, and delivery platforms, with great emphasis on development of chimeric antigens. Significant progress was also shown on the elucidation of Treponema pallidum genomes from virtually all continents to assess the diversity in vaccine candidates of the syphilis spirochete.

Skin Biopsy Detection of Phosphorylated α-Synuclein in Patients With Synucleinopathies.

Importance: Finding a reliable diagnostic biomarker for the disorders collectively known as synucleinopathies (Parkinson disease [PD], dementia with Lewy bodies [DLB], multiple system atrophy [MSA], and pure autonomic failure [PAF]) is an urgent unmet need. Immunohistochemical detection of cutaneous phosphorylated α-synuclein may be a sensitive and specific clinical test for the diagnosis of synucleinopathies. Objective: To evaluate the positivity rate of cutaneous α-synuclein deposition in patients with PD, DLB, MSA, and PAF. Design, Setting, and Participants: This blinded, 30-site, cross-sectional study of academic and community-based neurology practices conducted from February 2021 through March 2023 included patients aged 40 to 99 years with a clinical diagnosis of PD, DLB, MSA, or PAF based on clinical consensus criteria and confirmed by an expert review panel and control participants aged 40 to 99 years with no history of examination findings or symptoms suggestive of a synucleinopathy or neurodegenerative disease. All participants completed detailed neurologic examinations and disease-specific questionnaires and underwent skin biopsy for detection of phosphorylated α-synuclein. An expert review panel blinded to pathologic data determined the final participant diagnosis. Exposure: Skin biopsy for detection of phosphorylated α-synuclein. Main Outcomes: Rates of detection of cutaneous α-synuclein in patients with PD, MSA, DLB, and PAF and controls without synucleinopathy. Results: Of 428 enrolled participants, 343 were included in the primary analysis (mean [SD] age, 69.5 [9.1] years; 175 [51.0%] male); 223 met the consensus criteria for a synucleinopathy and 120 met criteria as controls after expert panel review. The proportions of individuals with cutaneous phosphorylated α-synuclein detected by skin biopsy were 92.7% (89 of 96) with PD, 98.2% (54 of 55) with MSA, 96.0% (48 of 50) with DLB, and 100% (22 of 22) with PAF; 3.3% (4 of 120) of controls had cutaneous phosphorylated α-synuclein detected. Conclusions and Relevance: In this cross-sectional study, a high proportion of individuals meeting clinical consensus criteria for PD, DLB, MSA, and PAF had phosphorylated α-synuclein detected by skin biopsy. Further research is needed in unselected clinical populations to externally validate the findings and fully characterize the potential role of skin biopsy detection of phosphorylated α-synuclein in clinical care.

Racial and ethnic differences in plasma biomarker eligibility for a preclinical Alzheimer's disease trial.

INTRODUCTION: In trials of amyloid-lowering drugs for Alzheimer's disease (AD), differential eligibility may contribute to under-inclusion of racial and ethnic underrepresented groups. We examined plasma amyloid beta 42/40 and positron emission tomography (PET) amyloid eligibility for the ongoing AHEAD Study preclinical AD program (NCT04468659). METHODS: Univariate logistic regression models were used to examine group differences in plasma and PET amyloid screening eligibility. RESULTS: Of 4905 participants screened at time of analysis, 1724 were plasma eligible to continue in screening: 13.3% Hispanic Black, 24.7% Hispanic White, 20.8% non-Hispanic (NH) Asian, 24.7% NH Black, and 38.9% NH White. Plasma eligibility differed across groups in models controlling for covariates (odds ratio from 1.9 to 4.0 compared to the NH White reference group, P < 0.001). Among plasma eligible participants, PET eligibility did not differ by group. DISCUSSION: These results suggest that prevalence of brain amyloid pathology differed, but that eligibility based on plasma was equally effective across racial and ethnic group members. HIGHLIGHTS: Plasma amyloid eligibility is lower in underrepresented racial and ethnic groups. In plasma eligible adults, positron emission tomography eligibility rates are similar across race and ethnicity. Plasma biomarker tests may be similarly effective across racial and ethnic groups.

Functional Role of an Unusual Transmembrane Acidic Residue in the Calcium Pump Regulator Myoregulin.

Myoregulin (MLN) is a member of the regulin family, a group of homologous membrane proteins that bind to and regulate the activity of the sarcoplasmic reticulum Ca2+-ATPase (SERCA). MLN, which is expressed in skeletal muscle, contains an acidic residue in its transmembrane domain. The location of this residue, Asp35, is unusual because the relative occurrence of aspartate is very rare (<0.2%) within the transmembrane helix regions. Therefore, we used atomistic simulations and ATPase activity assays of protein co-reconstitutions to probe the functional role of MLN residue Asp35. These structural and functional studies showed Asp35 has no effects on SERCA's affinity for Ca2+ or the structural integrity of MLN in the lipid bilayer. Instead, Asp35 controls SERCA inhibition by populating a bound-like orientation of MLN. We propose Asp35 provides a functional advantage over other members of the regulin family by populating preexisting MLN conformations required for MLN-specific regulation of SERCA. Overall, this study provides new clues about the evolution and functional divergence of the regulin family and offers novel insights into the functional role of acidic residues in transmembrane protein domains.

Understanding the Relationship Between Perseveration, Comorbid Behavioral Symptoms, Motor Decline, Functional Decline, and Self-report Accuracy in Huntington Disease Can Help Inform Clinical Practice.

BACKGROUND: Perseveration is one of the most debilitating symptoms of Huntington disease (HD). OBJECTIVE: To study perseveration and its relationship to comorbid behavioral symptoms, motor decline, functional decline, and subject self-report accuracy by analyzing cross-sectional data tracking individuals who have or are at risk for HD and healthy controls (HC). METHOD: We studied 96 individuals from HD families and 35 HC who were either family controls or gene negative. We used χ 2 tests to compare patient demographic and survey outcomes data and to analyze the presence of obsessions and compulsions (OC), depression, and apathy relative to the presence of perseveration. RESULTS: Individuals with HD and perseveration had a higher presence of OC, depression, and apathy compared with individuals with HD of the same stages without perseveration (19%, 47.6%, and 47.6% vs 15%, 40%, and 25%, respectively). In addition, individuals in HD Stages 1-3 with higher motor scores (showing a later stage of disease) displayed a significantly higher rate of perseveration than the HC ( P = 0.0476; P = 0.0499, respectively). The presence of an informant resulted in a significantly higher rate of perseveration reporting for individuals in HD Stages 1 and 2 (41.2% and 53.8% with informant vs 23.5% and 11.1% without informant, respectively). CONCLUSION: Perseveration was seen across all motor and functional stages for the individuals with HD, without significant differences between the different stages. Additionally, informants were beneficial to obtaining accurate patient reports of perseveration. These findings should prove useful for physician evaluation and treatment considerations.

Response to OKN-007 and NAC in a Patient with Unilateral Hearing Loss and Chronic Tinnitus from Vestibular Schwannoma.

BACKGROUND: Tinnitus is the perception of sound in the absence of external acoustic stimulation. Being one of the most common diseases of the ear, it has a global prevalence ranging from 4.1 to 37.2%. To date, it has been difficult to treat tinnitus as its pathophysiology is poorly understood and there are limited treatment options. OBJECTIVE: To investigate the effect of OKN-007 (also known as HPN-07), a nitrone-based investigational drug, in combination with oral N-acetylcycsteine (NAC), for the treatment of hearing loss and chronic tinnitus under an individual expanded access protocol. PATIENT CASE: We report the case of a patient who presented with left-sided ear fullness, mild tinnitus, and mild high frequency sensorineural hearing loss with 100% word recognition. A large enhancing mass seen on MRI revealed a vestibular schwannoma. He underwent subtotal resection of the tumor resulting in a moderate-to-profound sensorineural hearing loss and catastrophic tinnitus. The patient was treated with intravenous OKN-007 at 60 mg/kg dosed three times per week and oral NAC 2500 mg twice daily. RESULTS: Post-treatment audiometric testing revealed an average of 16.66 dB in hearing threshold improvement in three frequencies (125, 250 and 500 Hz) with residual hearing in the affected left ear. His tinnitus loudness matching improved from 90 dB to 19 dB post-treatment. His Tinnitus Handicap Inventory improved from 86/100 (Catastrophic) to 40/100 (Moderate). He also experienced improvements in sleep, concentration, hearing, and emotional well-being, and reported significantly decreased levels of tinnitusrelated distress. CONCLUSIONS: This case report highlights the feasibility and therapeutic potential of the combination of OKN-007 and NAC in treating hearing loss and tinnitus that warrants further investigation.

A case of fatal familial insomnia: diagnostic and therapeutic approaches.

Fatal Familial Insomnia (FFI) is an uncommon but fatal genetic condition that is characterized by severe progressive insomnia, dysautonomia, neuropsychiatric changes, and gait instability. Diagnostic workup includes genetic testing, EEG, MRI imaging of the brain, polysomnography, and CSF analysis. MRI brain imaging may be notable for areas of restricted diffusion in the thalamus. Therapeutic approaches are centered on symptom management, predominantly for insomnia. It is important for clinicians to consider FFI in patients presenting with progressive insomnia, cognitive deficits, and gait instability, and to direct patients and families toward genetic counseling and palliative care services.

ASSESSMENT OF RETINAL MICROVASCULAR ALTERATIONS IN INDIVIDUALS WITH AMNESTIC AND NONAMNESTIC MILD COGNITIVE IMPAIRMENT USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To assess retinal microvascular alterations in individuals with amnestic mild cognitive impairment (MCI) and nonamnestic MCI. METHODS: One hundred twelve eyes of 59 amnestic MCI participants, 32 eyes of 17 nonamnestic MCI participants, and 111 eyes of 56 controls with normal cognition were included. Optical coherence tomography angiography vessel density and perfusion density in the Early Treatment Diabetic Retinopathy Study 3-mm circle and ring were assessed. Retinal thickness parameters including retinal nerve fiber layer thickness, ganglion cell-inner plexiform layer thickness, central subfield thickness, and subfoveal choroidal thickness were also analyzed. Multivariable generalized estimating equations were used for statistical analysis. RESULTS: Perfusion density in the 3-mm inner ring was significantly lower in amnestic MCI patients when compared with nonamnestic MCI participants (0.29 ± 0.03 vs. 0.34 ± 0.09, P = 0.025) and controls with normal cognition (0.29 ± 0.03 vs. 0.39 ± 0.02, P < 0.001), after adjustment for age and sex as covariates. Vessel density, retinal nerve fiber layer thickness, ganglion cell-inner plexiform layer thickness, central subfield thickness, and subfoveal choroidal thickness did not differ among or between diagnostic groups. CONCLUSION: Perfusion density was significantly reduced in individuals with amnestic MCI, compared with those with nonamnestic MCI and controls with normal cognition.

A Comprehensive Analysis of Liver Transplantation Outcomes Among Ethnic Minorities in the United States.

GOALS: The aim of this study was to perform a comprehensive assessment of liver transplant (LT) outcomes among US adults with a specific focus on understanding race/ethnicity-specific disparities. BACKGROUND: Despite improvements in the liver allocation and LT-related care, disparities in LT outcomes persist. STUDY: Using data from the 2005 to 2016 United Networks for Organ Sharing LT registry, we evaluated waitlist survival, probability of receiving LT, and post-LT survival among US adults stratified by race/ethnicity and liver disease etiology. Kaplan-Meier methods evaluated unadjusted waitlist and post-LT outcomes, and multivariate regression models evaluated adjusted waitlist and post-LT outcomes. RESULTS: Among 88,542 listed for LT patients (41.3% hepatitis C virus, 25.3% alcoholic liver disease, 22.3% nonalcoholic steatohepatitis, 11.1% hepatitis C virus/alcoholic liver disease), significant race/ethnicity-specific disparities were observed. Compared with non-Hispanic whites, Hispanics had a significantly lower risk of waitlist death [hazard ratio (HR)=0.84, 95% confidence interval (CI): 0.79-0.90, P<0.001]. Compared with non-Hispanic whites, significantly lower likelihood of receiving LT was observed in African Americans (HR=0.94, 95% CI: 0.91-0.98, P<0.001), Hispanics (HR=0.70, 95% CI: 0.68-0.73, P<0.001) and Asians (HR=0.74, 95% CI: 0.69-0.80, P<0.001). Compared with non-Hispanic whites, African Americans had a significantly higher risk of 5-year post-LT death (HR=1.31, 95% CI: 1.23-1.39, P<0.001). CONCLUSION: Among US adults awaiting LT, significant race/ethnicity-specific disparities in LT outcomes were observed. Despite evaluating an era after implementation of the Model for End-Stage Liver Disease, ethnic minorities continue to demonstrate a lower probability of receiving LT, and significantly higher risk of death post-LT in African Americans.

Progressive supranuclear palsy and primary lateral sclerosis secondary to globular glial tauopathy: a case report and a practical theoretical framework for the clinical prediction of this rare pathological entity.

Globular glial tauopathy (GGT) is a rare 4-repeat tauopathy characterized by the accumulation of tau globular inclusions in astrocytes and oligodendrocytes. Several clinical phenotypes have been associated with GGT, making the prediction of this rare pathological entity difficult. We report the case of a patient with eye-movement abnormalities and gait instability, reminiscent of progressive supranuclear palsy-Richardson's syndrome (PSP-RS), who later developed upper motor neuron symptoms suggestive of primary lateral sclerosis (PLS). Neuropathological assessment revealed GGT type III pathology. A theoretical framework is proposed to help clinicians predict GGT in subjects with coexistent features of PSP-RS and PLS.

A genome-wide survey of CD4(+) lymphocyte regulatory genetic variants identifies novel asthma genes.

BACKGROUND: Genome-wide association studies have yet to identify the majority of genetic variants involved in asthma. We hypothesized that expression quantitative trait locus (eQTL) mapping can identify novel asthma genes by enabling prioritization of putative functional variants for association testing. OBJECTIVE: We evaluated 6706 cis-acting expression-associated variants (eSNPs) identified through a genome-wide eQTL survey of CD4(+) lymphocytes for association with asthma. METHODS: eSNPs were tested for association with asthma in 359 asthmatic patients and 846 control subjects from the Childhood Asthma Management Program, with verification by using family-based testing. Significant associations were tested for replication in 579 parent-child trios with asthma from Costa Rica. Further functional validation was performed by using formaldehyde-assisted isolation of regulatory elements (FAIRE) quantitative PCR and chromatin immunoprecipitation PCR in lung-derived epithelial cell lines (Beas-2B and A549) and Jurkat cells, a leukemia cell line derived from T lymphocytes. RESULTS: Cis-acting eSNPs demonstrated associations with asthma in both cohorts. We confirmed the previously reported association of ORMDL3/GSDMB variants with asthma (combined P = 2.9 × 10(-8)). Reproducible associations were also observed for eSNPs in 3 additional genes: fatty acid desaturase 2 (FADS2; P = .002), N-acetyl-α-D-galactosaminidase (NAGA; P = .0002), and Factor XIII, A1 (F13A1; P = .0001). Subsequently, we demonstrated that FADS2 mRNA is increased in CD4(+) lymphocytes in asthmatic patients and that the associated eSNPs reside within DNA segments with histone modifications that denote open chromatin status and confer enhancer activity. CONCLUSIONS: Our results demonstrate the utility of eQTL mapping in the identification of novel asthma genes and provide evidence for the importance of FADS2, NAGA, and F13A1 in the pathogenesis of asthma.

Tracheostomy Decision Making and Counseling: Comparing Providers' and Caregivers' Perspectives and Perceptions.

Background: The decision to place a tracheostomy in children is complex and involves factors beyond the medical procedure, including quality of life, values, and goals. Providers play an important role in counseling caregivers and guiding them through the decision-making process. There are no established guidelines for tracheostomy counseling, leading to variations in practice. Additionally, how caregivers receive information differs from how providers believe they deliver it. Although studies have explored caregivers' and providers' viewpoints, none have examined them concurrently. Background: The primary aim of this exploratory study is to investigate differences between providers' and caregivers' perceptions of tracheostomy counseling and their perspectives regarding the decision-making process. Design: Semi-structured interviews were conducted with both caregivers and providers for children being evaluated for a tracheostomy. Qualitative analysis was applied to the interview transcripts to identify emergent themes. Subsequently, a comparative analysis was performed to compare these themes between caregivers and healthcare providers. Results: A total of 33 interviews were conducted, involving 16 caregivers and 17 providers. Notably, caregivers provided personal descriptions of their children in 81% of cases, whereas only 35% of providers did so. Concerns and fears for the children were expressed by 69% of caregivers and 59% of providers. In contrast, 75% of caregivers discussed their hopes and dreams for their children, compared with only 29% of providers. When it came to priorities, 69% of caregivers emphasized growth and development, and 38% mentioned discharge home, as opposed to 29% and 47% among providers, respectively. Conclusion: In conclusion, our study highlights a disconnect between caregivers and healthcare providers regarding tracheostomy counseling. These differing perspectives underscore the need for improved communication and understanding between the two groups. Recognizing these differences can help providers tailor their counseling approaches to better align with the values and priorities of families when making decisions about tracheostomy.

Anomalous coronary artery masquerading as a root abscess: a case report.

Congenital coronary artery anomalies are rare and most often clinically benign. We present a case of a 67-year-old male with osteomyelitis and persistent bacteremia with an anomalous left coronary artery mimicking an aortic root abscess. A transesophageal echocardiogram revealed a hypoechoic potential space around the aortic root, highly suspicious for a root abscess. Urgent cardiac surgery was performed, revealing no infection but an anomalous coronary artery arising from the right coronary sinus. This case highlights the importance of considering atypical anatomy in the diagnosis of infectious cardiac processes. While this resemblance should not delay intervention for suspected abscesses, it emphasizes the need to be aware of congenital differences in imaging for patients with known anomalies or asymptomatic patients with unknown anatomy.

Abnormal coronary arteries are rare and are usually not dangerous. We present a case of a 67-year-old male with an infection in the bone and persistent findings of bacteria in the blood who had an abnormal coronary artery that mimicked an infected space. Ultrasound of the heart found thickening and a space around the aortic root, highly suspicious for an infection in the setting of bacteria in the blood. Urgent surgery was performed, revealing no signs of infection but abnormal coronary artery anatomy. This case highlights the importance of considering atypical anatomy in the diagnosis of infection around the heart. While this should not delay intervention, it emphasizes the need to be aware of differences in anatomy.

Civilian Ballistic Arthrotomies: Infection Rates and Operative Versus Nonoperative Management.

OBJECTIVES: The purpose of this study was to determine whether a significant difference existed in the rate of infection after ballistic traumatic arthrotomy managed operatively compared with those managed without surgery. DESIGN: Retrospective cohort study. SETTING: Academic Level I Trauma Center. PATIENT SELECTION CRITERIA: Patients with ballistic traumatic arthrotomies of the shoulder, elbow, wrist, hip, knee, or ankle who received operative or nonoperative management. OUTCOME MEASURES AND COMPARISONS: The rates of infection and septic arthritis in those who received operative or nonoperative management. RESULTS: One hundred ninety-five patients were studied. Eighty patients were treated nonoperatively (Non-Op group), 16 patients were treated with formal irrigation and debridement in the operating room (I&D group), and 99 patients were treated with formal I&D and open reduction and internal fixation (ORIF) (I&D + ORIF group). Patients in all 3 groups received local wound care and systemic antibiotics. No patients in the Non-Op or I&D group developed an infection. Six patients in the I&D + ORIF group developed extra-articular postoperative infections requiring additional interventions. CONCLUSIONS: The infection rate in the I&D + ORIF group was consistent with the infection rates reported in orthopaedic literature after fixation alone. In addition, none of the infections were cases of septic arthritis. This suggests that traumatic arthrotomy does not increase the risk for infection beyond what is expected after fixation alone. Importantly, the Non-Op group represented a series of 80 patients who were treated nonoperatively without developing an infection, indicating that I&D may not be necessary to prevent infection after ballistic arthrotomy. The results suggest that septic arthritis after civilian ballistic arthrotomy is a rare complication regardless of the choice of treatment. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.