Spillover of highly pathogenic avian influenza H5N1 virus to dairy cattle.

The highly pathogenic avian influenza (HPAI) H5N1 virus clade 2.3.4.4b has caused the death of millions of domestic birds and thousands of wild birds in the USA since January 2022 (refs. 1-4). Throughout this outbreak, spillovers to mammals have been frequently documented5-12. Here we report spillover of the HPAI H5N1 virus to dairy cattle across several states in the USA. The affected cows displayed clinical signs encompassing decreased feed intake, altered faecal consistency, respiratory distress and decreased milk production with abnormal milk. Infectious virus and viral RNA were consistently detected in milk from affected cows. Viral distribution in tissues via immunohistochemistry and in situ hybridization revealed a distinct tropism of the virus for the epithelial cells lining the alveoli of the mammary gland in cows. Whole viral genome sequences recovered from dairy cows, birds, domestic cats and a raccoon from affected farms indicated multidirectional interspecies transmissions. Epidemiological and genomic data revealed efficient cow-to-cow transmission after apparently healthy cows from an affected farm were transported to a premise in a different state. These results demonstrate the transmission of the HPAI H5N1 clade 2.3.4.4b virus at a non-traditional interface, underscoring the ability of the virus to cross species barriers.

Measurement Properties of Backward Walking and Its Sensitivity and Feasibility in Predicting Falls in People With Multiple Sclerosis.

BACKGROUND: People with multiple sclerosis (MS) experience mobility impairments that elevate fall risk, increasing the need to identify clinical measures that accurately predict falls. Backward walking (BW) better differentiates fallers from nonfallers in MS. However, no studies have reported the measurement properties of the backward walking Timed 25-Foot Walk (B-T25-FW) and BW metrics, like BW velocity. Additionally, it is unknown whether BW can predict future falls in MS or its link to activity levels. This study assessed the reliability and responsiveness of B-T25-FW and BW metrics, including BW velocity. It also examined whether BW could predict falls at 3 and 6 months and its association with activity levels. METHODS: During 2 separate visits, 23 people with MS completed the forward walking Timed 25-Foot Walk (F-T25-FW) and B-T25-FW, as well as forward walking and BW assessments in which spatiotemporal measures were recorded. Test-retest reliability was determined with intraclass correlation coefficients, and minimum detectable changes were calculated. Correlation analyses explored the relationship between BW velocity, B-T25-FW, prospective falls, and activity levels. RESULTS: B-T25-FW and BW velocity exhibited excellent test-retest reliability. Large effect sizes to interpret clinically meaningful change in the B-T25-FW and BW velocity were also found. Both metrics demonstrated modest negative correlations with falls at 3 and 6 months and correlated strongly with very active minutes at 3- and 6-months post study. CONCLUSIONS: The B-T25-FW and BW velocity are effective and reliable in clinical use for evaluating functional mobility in people with MS, are sensitive enough to detect subtle changes, and may be a meaningful marker for tracking disease progression and treatment efficacy.

Cerebellar volume measures may differentiate multiple sclerosis fallers from non-fallers.

Introduction: The cerebellum is a common lesion site in persons with multiple sclerosis (PwMS). Physiologic and anatomic studies have identified a topographic organization of the cerebellum including functionally distinct motor and cognitive areas. This study implemented a recent parcellation algorithm developed by Han et al., 2020 to a sample of PwMS and healthy controls to examine relationships among specific cerebellar regions, fall status, and common clinical measures of motor and cognitive functions. Methods: Thirty-one PwMS and 29 age and sex-matched controls underwent an MRI scan and motor and cognitive testing. The parcellation algorithm was applied to all images and divided the cerebellum into 28 regions. Mann-Whitney U tests were used to compare cerebellar volumes among PwMS and controls, and MS fallers and MS non-fallers. Relationships between cerebellar volumes and motor and cognitive function was evaluated using Spearman correlations. Results: PwMS performed significantly worse on functional measures compared to controls. We found significant differences in volumetric measures between PwMS and controls in the corpus medullare, lobules I-III, and lobule V. Volumetric differences seen between PwMS and controls were primarily driven by the MS fallers. Finally, functional performance on motor and cognitive tasks was associated with cerebellar volumes. Conclusions: Using the parcellation tool, our results showed that volumes of motor and cognitive lobules impact both motor and cognitive performance, and that functional performance and cerebellar volumes distinguishes MS fallers from non-fallers. Future studies should explore the potential of cerebellar imaging to predict falls in PwMS.

Reassessing Stephanofilaria stilesi dermatitis in cattle, with characterization of molecular markers for confirming diagnosis.

BACKGROUND: Stephanofilaria stilesi is a vector-borne filarioid nematode of cattle in North America that is transmitted via the hematophagous horn fly (Haematobia irritans) intermediate host. Despite being relatively common, little attention has been given to a thorough description of S. stilesi lesions and the potential integration of pathological and molecular diagnostic findings to confirm infection. METHODS: To characterize the cutaneous lesions caused by S. stilesi in cattle (Bos taurus taurus and Bos taurus indicus), skin of the ventral abdominal midline was collected from 22 animals during postmortem examination. Skin samples were processed for histology, transmission electron microscopy (TEM), DNA extraction, PCR, and Sanger sequencing targeting molecular markers cytochrome oxidase c subunit 1 (cox1), 12S, 18S rDNA, and 28S rDNA. RESULTS: Macroscopically, lesions ranged from 5 × 4 cm to 36 × 10 cm, consisting of one large single lesion, or two to four ovoid areas at the ventral abdominal midline, surrounding the umbilicus. Each lesion presented as ulcerative dermatitis with dry, serocellular crusts, or alopecic and lichenified areas. Histologically, eosinophilic, neutrophilic, and ulcerative dermatitis with furunculosis, folliculitis, and epidermal hyperplasia was observed. Cross sections of adult nematodes were identified in ~ 60% of the cases (n = 13) within intact follicles, sebaceous ducts, crusts, and areas of furunculosis. Stephanofilaria first-stage larvae (L1) were observed in five cases within "vitelline membranes" in the superficial dermis and crusts. Ultrastructurally, the L1 cross sections were compounded of smooth multilayered cuticle and somatic cells. The "vitelline membrane" is a tri-layered membrane where L1 are suspended in a matrix. Stephanofilaria stilesi DNA was found in 5 out of the 13 cases in which adults or L1 were histologically observed (38%) and in 1 out of the 9 cases without adults or L1 present (11%). Phylogenetic analyses suggest a closer relationship of the genus Stephanofilaria with Thelazioidea, instead of the family Filariidae (Filarioidea), in which it has been historically allocated. CONCLUSIONS: Our study improved the characterization of lesions and described ultrastructural findings of S. stilesi and highlights that molecular tools should be utilized in combination with histology for improved diagnostic resolution.

Examining the Influence of Cognition on the Relationship Between Backward Walking and Falls in Persons With Multiple Sclerosis.

BACKGROUND: Multiple sclerosis (MS) causes motor, cognitive, and sensory impairments that result in injurious falls. Current fall risk measures in MS (ie, forward walking [FW] speed and balance) are limited in their sensitivity. Backward walking (BW) velocity is a sensitive marker of fall risk and correlates with information processing speed (IPS) and visuospatial memory (VSM) in persons with MS. Backward walking is a complex motor task that requires increased cognitive demands, which are negatively affected by MS; however, whether cognitive function modifies the sensitivity of BW as a fall risk assessment in MS remains unknown. This study examines the influence of cognition on the relationship between BW and falls in persons with MS. METHODS: Measures of BW, FW, IPS, VSM, and retrospective falls were collected. Hierarchical regression tested moderation and included an interaction term predicting number of falls. Covariates for all analyses included age and disease severity. RESULTS: Thirty-eight persons with MS participated. Although BW, IPS, and covariates significantly predicted the number of falls (R 2 = 0.301; P = .016), there was no evidence of moderation. Backward walking, VSM, and covariates also significantly predicted number of falls (R 2 = 0.332, P = .008), but there was no evidence of moderation. The FW models generated comparable results. CONCLUSIONS: The relationship between BW velocity and falls was not conditional on IPS or VSM in this sample. Larger-scale studies examining additional cognitive domains commonly affected by MS and prospective falls are needed to characterize neurobiological processes relevant to BW and its clinical application in the assessment of fall risk.

A Scalable 3D High-Content Imaging Protocol for Measuring a Drug Induced DNA Damage Response Using Immunofluorescent Subnuclear γH2AX Spots in Patient Derived Ovarian Cancer Organoids.

The high morbidity rate of ovarian cancer has remained unchanged during the past four decades, partly due to a lack of understanding of disease mechanisms and difficulties in developing new targeted therapies. Defective DNA damage detection and repair is one of the hallmarks of cancer cells and is a defining characteristic of ovarian cancer. Most in vitro studies to date involve viability measurements at scale using relevant cancer cell lines; however, the translation to the clinic is often lacking. The use of patient derived organoids is closing that translational gap, yet the 3D nature of organoid cultures presents challenges for assay measurements beyond viability measurements. In particular, high-content imaging has the potential for screening at scale, providing a better understanding of the mechanism of action of drugs or genetic perturbagens. In this study we report a semiautomated and scalable immunofluorescence imaging assay utilizing the development of a 384-well plate based subnuclear staining and clearing protocol and optimization of 3D confocal image analysis for studying DNA damage dose response in human ovarian cancer organoids. The assay was validated in four organoid models and demonstrated a predictable response to etoposide drug treatment with the lowest efficacy observed in the clinically most resistant model. This imaging and analysis method can be applied to other 3D organoid and spheroid models for use in high content screening.

Associations between myelin water imaging and measures of fall risk and functional mobility in multiple sclerosis.

BACKGROUND AND PURPOSE: Myelin water fraction (MWF) deficits as measured by myelin water imaging (MWI) have been related to worse motor function in persons with multiple sclerosis (PwMS). However, it is unknown if measures from MWI metrics in motor areas relate to fall risk measures in PwMS. The objective of this study was to examine the relationship between MWI measures in motor areas to performance on clinical measures of fall risk and disability in PwMS. METHODS: Sixteen individuals with relapsing-remitting MS participated (1 male, 15 female; age 47.1 years [12.3]; Expanded Disability Status Scale 4.0 [range 0-6.5]) and completed measures of walking and fall risk (Timed 25 Foot Walk [T25FW] and Timed Up and Go). MWF and the geometric mean of the intra-/extracellular water T2 (geomT2IEW ) values reflecting myelin content and contribution of large-diameter axons/density, respectively, were assessed in three motor-related regions. RESULTS: The geomT2IEW of the corticospinal tract (r = -.599; p = .018) and superior cerebellar peduncles (r = -.613; p = .015) demonstrated significant inverse relationships with T25FW, suggesting that decreased geomT2IEW was related to slower walking. Though not significant, MWF in the corticospinal tract and superior cerebellar peduncles also demonstrated fair relationships with the T25FW, suggesting that worse performance on the T25FW was associated with lower MWF values. CONCLUSIONS: MWI of key motor regions was associated with walking performance in PwMS. Further MWI studies are needed to identify relationships between pathology and clinical function in PwMS to guide targeted rehabilitation therapies aimed at preventing falls.

Subcutaneous Implantation of Hepatocellular Carcinoma in a Dog.

A 13-year-old male neutered Cocker Spaniel mixed-breed dog developed a subcutaneous mass 2 years after undergoing surgery to remove a hepatocellular carcinoma. An approximately 4 × 3 cm subcutaneous mass was found on the ventral abdomen at the cranial end of the abdominal incision from the previous surgery. The subcutaneous mass was surgically removed and histopathological examination determined that it was an implantation of the previously excised hepatocellular carcinoma. The diagnosis was confirmed by immunohistochemical labelling with hepatocyte paraffin 1 antibody and pancytokeratin. Based on the location of the subcutaneous mass at the cranial end of the abdominal incision associated with the previous hepatocellular carcinoma resection, it is likely there was iatrogenic metastasis from the primary tumour excision. Subcutaneous iatrogenic metastasis of hepatocellular carcinoma is well recognized in humans but has apparently never been reported in dogs. Clinicians should be aware of this potential surgical complication.

Clostridium piliforme and canine distemper virus coinfection in 2 domestic dog littermates and a gray fox kit.

Concurrent Clostridium piliforme and canine distemper virus (CDV) infection was diagnosed in 2 canine littermates and 1 gray fox kit from Texas, USA. In all 3 animals, intracytoplasmic, filamentous bacteria, consistent with C. piliforme, were present along the margins of foci of hepatic necrosis. Additional histologic findings included intracytoplasmic and intranuclear inclusion bodies in bile duct and bronchial epithelial cells of the fox kit, and mild intestinal necrosis in 1 puppy. PCR assays confirmed the presence of C. piliforme in all 3 animals, CDV in both puppies, and canine parvovirus in 1 puppy. Fluorescent antibody testing confirmed the presence of CDV in the fox kit. Concurrent canine distemper and Tyzzer disease in canine littermates and the gray fox has not been reported previously, to our knowledge.

Dirofilaria immitis in an Asian small-clawed otter (Aonyx cinereus) from southeastern Louisiana, United States.

A single, male Dirofilaria immitis was found in the right ventricle of a captive, 10-month-old female Asian small-clawed otter (Aonyx cinereus) from East Feliciana parish in Louisiana, USA. Molecular analysis was performed for unequivocal species level identification using the cytochrome c oxidase subunit 1 (cox1) region of the mitochondrial DNA and comparing to known D. immitis cox1 sequences available on GenBank to which the specimen had a 99.54-100% pair wise identity. As there is no safe adulticidal treatment for D. immitis in mustelids, chemoprophylaxis using macrocyclic lactones is recommended to prevent infection. Further studies are needed to better characterize D. immitis infection and its propensity to cause disease in the Asian small-clawed otter.

Using myelin water imaging to link underlying pathology to clinical function in multiple sclerosis: A scoping review.

BACKGROUND: Multiple sclerosis (MS) symptoms and pathology are heterogenous and complex. Identifying links between MS-related pathology (i.e., myelin damage) and associated clinical symptoms is critical for developing targeted therapeutics. Conventional MRI, commonly used for MS diagnosis and disease monitoring, lacks specificity with functional performance. Myelin water imaging (MWI) demonstrates increased specificity to myelin and is viewed as the gold standard for imaging myelin content in vivo. Yet, there is a paucity of MWI studies in MS and only a limited number also examine clinical function. Thus, it remains unknown whether MWI corresponds to functional performance in MS. This scoping review aimed to examine relations between MWI and functional domains relevant to MS to inform and guide future research. METHODS: Seven databases were searched from their inception to September 1, 2021. Studies of adults with MS that included both brain MWI and either a measure of physical function, a measure of cognitive function, or a measure of disease severity were included. Thirteen studies (11 observational, 2 intervention) met the inclusion criteria. RESULTS: The most commonly investigated MWI metric is the myelin water fraction (MWF). Persons with MS demonstrated markedly decreased MWF compared to healthy controls globally and across brain regions of interest (ROIs). Decreased MWF was associated with higher disability, worse motor and cognitive performance and decreased intervention response. Only five studies examined structure-function relationships in brain areas related to walking and cognitive function and only six studies extracted MWI metrics from explicit brain ROIs. CONCLUSIONS: MWI is a neuroimaging technique with increased specificity to myelin and offers greater insight to MS-driven pathology and its clinical manifestations, including motor and cognitive dysfunction and rehabilitation response. This scoping review identified critical gaps in MWI research in MS to offer future perspectives including ROI-based studies, inclusion of multi-domain functional assessment and examining MWI to provide evidence of neuroplasticity following training.

Cerebellar Contributions to Motor and Cognitive Control in Multiple Sclerosis✰✰✰.

OBJECTIVE: To evaluate relationships between specific cerebellar regions and common clinical measures of motor and cognitive function in persons with multiple sclerosis (PwMS). DESIGN: Cross-sectional. SETTING: Laboratory. PARTICIPANTS: Twenty-nine PwMS and 28 age- and sex-matched controls without multiple sclerosis (MS) (N=57). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Both diffusion and lobule magnetic resonance imaging analyses and common clinical measures of motor and cognitive function were used to examine structure-function relationships in the cerebellum. RESULTS: PwMS demonstrate significantly worse motor and cognitive function than controls, including weaker strength, slower walking, and poorer performance on the Symbol Digit Modalities Test, but demonstrate no differences in cerebellar volume. However, PwMS demonstrate significantly worse diffusivity (mean diffusivity: P=.0003; axial diffusivity: P=.0015; radial diffusivity: P=.0005; fractional anisotropy: P=.016) of the superior cerebellar peduncle, the primary output of the cerebellum. Increased volume of the motor lobules (I-V, VIII) was significantly related to better motor (P<.022) and cognitive (P=.046) performance, and increased volume of the cognitive lobules (VI-VII) was also related to better motor (P<.032) and cognitive (P=.008) performance, supporting the role of the cerebellum in both motor and cognitive functioning. CONCLUSIONS: These data highlight the contributions of the cerebellum to both motor and cognitive function in PwMS. Using novel neuroimaging techniques to examine structure-function relationships in PwMS improves our understanding of individualized differences in this heterogeneous group and may provide an avenue for targeted, individualized rehabilitation aimed at improving cerebellar dysfunction in MS.

Cerebellar Dysfunction in Multiple Sclerosis: Considerations for Research and Rehabilitation Therapy.

Introduction. Cerebellar pathology is common among persons with multiple sclerosis (PwMS). The cerebellum is well recognized for its role in motor control and motor learning and cerebellar pathology in multiple sclerosis is associated with enhanced motor impairment and disability progression. The Problem. To mitigate motor disability progression, PwMS are commonly prescribed exercise and task-specific rehabilitation training. Yet, whether cerebellar dysfunction differentially affects rehabilitation outcomes in this population remains unknown. Furthermore, we lack rehabilitation interventions targeting cerebellar dysfunction. The Solution. Here, we summarize the current understanding of the impact of cerebellar dysfunction on motor control, motor training, and rehabilitation in persons with multiple sclerosis. Recommendations. Additionally, we highlight critical knowledge gaps and propose that these guide future research studying cerebellar dysfunction in persons with multiple sclerosis.

COVID-19 Pandemic and Impact on Patients with Autism Spectrum Disorder.

The COVID-19 infectious disease pandemic has caused significant fear and uncertainty around the world and had significant adverse psychological impact. Children, adolescents and adults with autism spectrum disorder (ASD) are a particularly vulnerable population, impacted by stay-at-home orders, closures at nonessential services, and social distancing standards. This commentary describes various challenges faced by individuals with ASD in the United States including disruptions caused by educational and vocational changes, challenges to home and leisure routines, limited access to behavioral health services and changes in health services delivery due to the pandemic. We highlight the need for ongoing skills development for individuals and development within systems to better respond to needs of the ASD population in future emergencies.

Fatal cerebral cuterebrosis in a dog.

A 4-year-old intact female Yorkshire Terrier presented an acute onset of hypersalivation and depressed mentation. The owner reported that the dog displayed tremors, right-sided torticollis, right-sided head tilt, and lifting of the left forelimb. The dog appeared restless and confused, and the condition progressed to lethargy and death on the way to an emergency hospital. At necropsy, a single 10 mm long x 1 mm wide, pale gray, botfly larva with black spines was found along the cerebral meninges. Areas of hemorrhage were noted in the right cerebral hemisphere. Microscopically, these areas also had evidence of necrosis and inflammation. Morphology of the larva allowed confirmation of subfamily-level identification as Cuterebrinae, and presumed genus-level identification of Cuterebra. Species-level identification of the larva as C. abdominalis was achieved through DNA extraction, PCR and sequencing at the cytochrome oxidase subunits 1 and 2 (COI and COII), followed by phylogenetic analysis. Aberrant cuterebrosis is a poorly documented condition in dogs that may cause neurologic signs and lead to death.

Validating the walking while talking test to measure motor, cognitive, and dual-task performance in ambulatory individuals with multiple sclerosis.

INTRODUCTION: Multiple Sclerosis (MS) is associated with demyelination of the central nervous system that negatively impacts both motor and cognitive function, resulting in difficulty performing simultaneous motor and cognitive tasks, or dual-tasks. Declines in dual-tasking have been linked with falls in MS; thus, dual-task assessment with the Walking While Talking Test (WWTT) is commonly utilized in the clinical setting. However, the validity and minimal detectable change (MDC) of the WWTT has not been established for persons with MS. The primary objective of the study was to establish the WWTT as a valid measure of dual-task function by examining concurrent validity with other motor, cognitive and dual-task measures, and to establish the MDC for both the simple and complex conditions of the WWTT. METHODS: In a single visit, 38 adults (34 female, mean (SD) age 49.8(±9.1), Patient Determined Disease Steps (PDDS) mean 3, range 1-6) completed the WWTT simple (walk while reciting the alphabet) and complex (walk while reciting every other letter of the alphabet) conditions as well as a battery of cognitive and motor tests. Spearman correlations were used to examine concurrent validity. The sample was divided into low and high disability groups to determine the impact of disability severity on relationships among WWTT and cognitive and motor function. RESULTS: Excellent concurrent validity (r ≥ 0.79; p < 0.001) was observed for the WWTT simple and complex with both motor (Timed Up-and-Go, Timed 25-Foot Walk, forward and backward walking velocity, Six-Spot Step Test) and dual-task measures (Timed Up-and-Go Cognitive). The WWTT-simple demonstrated moderate concurrent validity with measures of processing speed (Symbol Digit Modalities Test, p = 0.041) and was related to all motor and dual-task measures across disability levels. The WWTT complex was only related to complex motor tasks in the low disability group. Within the low disability group, WWTT was associated with processing speed (p = 0.045) and working memory (California Verbal Learning Test, p = 0.012). The MDC values were established for WWTT simple (6.9 s) and complex (8 s) conditions. DISCUSSION: The WWTT is a quick, easy-to-administer clinical measure that captures both motor and cognitive aspects of performance for persons with MS. Clinicians should consider adding the WWTT to the evaluation of persons with MS to examine dual-task performance.

Retrospective Survey of Amphibian Pathology Cases at Texas A&M University System (2016-2020).

Dramatic declines in amphibians worldwide highlight the need for a better understanding of diseases affecting these species. To delineate the health issues of amphibians submitted to Texas A&M University System (2016-2020), the databases were queried on the basis of defined selection criteria. A total of 502 anurans (157 frogs [44 species] and 345 toads [10 species]) and 30 caudatans (23 salamanders [6 species] and 7 newts [4 species]) were reviewed. A most likely cause of death or major pathological finding (CD-MPF) leading to euthanasia was identified in 295 (55%) Anura cases and 15 (50%) Caudata cases. Of the 532 records reviewed, anurans included 492 captive, seven free-ranging and three undetermined specimens. All caudatans were captive. The most common CD-MPF in anurans was infectious/inflammatory (228/295; 77%), involving mycobacteriosis (73/228; 32%), chlamydiosis (44/228; 19%) and mycosis (32/228; 14%). Neoplasia was less common (28/295; 9%). Infectious/inflammatory lesions (14/15; 93%) were the main CD-MPFs in caudatans. Infectious diseases are a significant threat to captive amphibians in Texas and these results may aid personnel involved in amphibian conservation programmes, veterinarians and diagnosticians.

Fatal Chagas myocarditis in government working dogs in the southern United States: Cross-reactivity and differential diagnoses in five cases across six months.

We describe the diagnostics surrounding the deaths of five working dogs over six-months to provide an enhanced clinical and diagnostic understanding of canine Chagas disease. Cases were five dogs with antibodies to Trypanosoma cruzi. Medical records were reviewed for diagnostic history. Testing was performed from samples collected before or immediately after death, including measurement of cardiac troponin I, histology, PCR and serology for Leishmania spp. and T. cruzi. Four dogs had a 2 to 7-year history of T. cruzi antibodies, while one positive dog had an unknown duration of exposure. Age at death ranged from 2 to 11 years and four dogs were actively working. The cardiac troponin I was elevated in all four dogs for which it was measured, although postmortem reference ranges are not established. Histopathologic diagnoses included mild to severe, chronic, lymphoplasmacytic to histiocytic myocarditis with variable fibrosis. Notably, only one dog had T. cruzi amastigotes observed in the heart histologically. T. cruzi DNA was detected in three other hearts. Although all five dogs tested antibody-positive for T. cruzi using three independent tests, all were also indirect fluorescent antibody-positive for Leishmania spp., interpreted as cross-reaction. Chagas disease in dogs is a diagnostic challenge owing to cross-reactions and variable clinical, histologic and molecular presentations. The use and interpretation of multiple diagnostic strategies is useful in diagnosis. This study demonstrates techniques used to diagnose and characterize Chagas disease in an at-risk dog population.