High toxocariasis seroprevalence in a tri-border indigenous community (Brazil, Paraguay and Argentina): A One Health perspective

One Health · 2025-06-10 · 2 citations

Toxocariasis, a neglected parasitic zoonosis, has mostly affected vulnerable populations of subtropical and tropical regions worldwide. In addition to vulnerability, indigenous communities have long existed before bordering areas, particularly in South American countries, leading to cultural isolation, migratory and environmental concerns, lately associated to low human infrastructure and lack of healthcare policies. Accordingly, the study herein has serosurveyed anti- Toxocara spp. antibodies in indigenous persons, and surveyed Toxocara spp. in their dog and soil samples from a Guarani-Mabyá indigenous community located in a tri-border area of Brazil, Paraguay and Argentina. Overall, seropositivity was detected in 246/258 (95.3 %; 95 % CI: 92.1–97.3) indigenous persons, with no statistically associated risk factor to seropositivity, likely due to the highest human toxocariasis seroprevalence reported to date worldwide. Although detected in only 8/124 (6.5 %) dog feces samples, Toxocara spp. eggs were present in 13/42 (30.9 %) soil samples of common areas and 17/32 (53.1 %) of households, molecularly identified as T. canis by DNA amplification. The significant number of infective Toxocara spp. eggs found in the soil samples has reinforced the role of daily environmental exposure in sustaining transmission within this community, which may reflect the pattern of disease status in other nearby indigenous communities. Moreover, migratory behavior of Guarani ethnicity across the tri-border may have spread infection to other border indigenous communities of Brazil, Paraguay and Argentina.

The expanding role of microRNAs in the biology and control of veterinary parasitic nematodes

Frontiers in Veterinary Science · 2025-09-19 · 1 citations

Parasitic nematodes threaten animal health globally, contributing to substantial losses in livestock productivity and posing zoonotic risks through infections in companion animals. There is a growing concern over widespread resistance to anthelmintic drugs, necessitating new molecular approaches for parasite control. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and have emerged as key modulators of nematode development, growth, stage transitions, host-pathogen interactions, and parasite survival. Certain miRNAs are expressed in a stage- and sex-specific manner, and many are selectively secreted via extracellular vesicles, enabling direct interactions with the host. The detection of worm-derived miRNAs in blood of an infected host highlights their potential as early diagnostic biomarkers for nematode infections. Emerging evidence links miRNAs to anthelmintic resistance. This review provides an overview of miRNA biogenesis, gene regulation mechanisms, and current miRNA discovery and experimental validation approaches. Importantly, it highlights species-specific advances in miRNA research in parasitic nematode infections of veterinary importance, emphasizing their roles in parasite biology, immune modulation, and drug resistance.

Modulating autism spectrum disorder pathophysiology using a trace amine-focused approach: targeting the gut

Molecular Medicine · 2025-05-20 · 1 citations

Autism spectrum disorder (ASD) affects approximately 1% of the population directly, but also a much higher proportion (family and caregivers) indirectly. Although ASD is characterized by high prevalence of anxiety and poor gastrointestinal health, current treatment strategies are mainly focused on neurological symptomatic treatment, with little to no attention to gut health. Furthermore, many psychiatric drugs used for management of secondary neurological symptoms, are known to exacerbate gut health issues and neurological dysregulation across the gut-brain axis.Trace amines are neurotransmitter-like substances synthesized endogenously in the human brain - in trace amounts - but also in high abundance by the microbiome. Emerging evidence suggests dysregulation of the trace amine system in ASD. Since trace aminergic signalling is central to regulatory system homeostasis, we hypothesize targeting this system in the ASD context. Given the various sources of trace amines, we suggest that normalization of functional dysbiosis in terms of trace aminergic signalling - rather than microbial compositional dysbiosis - should be a focus in medicines development. In addition, a holistic consideration including also other factors at play in determining trace aminergic signalling outcome - such as receptor binding, enzymatic role players, etc. - is required to fully elucidate and therapeutically modify the pathophysiology of regulatory systems implicated in ASD.This review firstly provides a brief overview of trace amine dysregulation in ASD for context. Secondly, we formulate our hypothesis on how this may therapeutically address symptomology, with consideration of cellular and molecular mechanism interplay across the gut-brain axis. Finally, we provide a critical assessment of advances in therapeutics development and drug re-purposing, gaps in knowledge and priorities for medicines development going forward.

What’s your diagnosis? Globular to amorphous material in peripheral blood smears

Veterinary Clinical Pathology · 2025-06-03

Three 8-week-old research dogs (two male intact Victorian Bulldogs and one female intact Shih Tzu) had peripheral blood submitted to the Purdue University Veterinary Hospital Clinical Pathology Laboratory (PUVHCPL) for a health screening. These dogs were enrolled in a study aimed at understanding the impact of ground transportation on puppy welfare. All research dogs were considered healthy and had no significant abnormalities observed on physical exam. The dogs were not currently being injected with any fluids or medications. However, as a form of pain management during blood draws, lidocaine cream was applied locally at the blood draw site five minutes before blood collection on each dog. The blood draw site was performed with a 22-, 23-, or 25-gauge needle and included either the jugular vein or cephalic vein. The medical technologist at PUVHCPL observed an unknown material observed at the feathered edge of all blood smears from these dogs, which triggered a review by the clinical pathologist for further evaluation. The peripheral blood of one Victorian Bulldog was analyzed using the Advia 2120i Hematology System (Siemens, Washington, DC). Additionally, all three research dogs had peripheral blood smears stained with Modified Wright stain and processed using the Siemens Hema-Tek 3000 system. Since the other two research dogs were only submitted for slide review, their blood was not analyzed by the Advia system. The scatterplots from the Victorian Bulldog only showed abnormalities in the “Baso” channel (Figure 1), where a continuous, linear abnormality is seen going through the mononuclear area of the scatterplot and into where basophils are typically located. This abnormality is presumed to be due to the lidocaine gel since no other abnormalities that could cause this change were noted in the dog's peripheral blood. The smears were evaluated by a clinical pathology resident (EA) and deemed to be of good diagnostic quality without evidence of any age-related changes. Leukocyte numbers and erythrocyte density of two dogs were within normal limits. One dog had minimal macrocytic hypochromic anemia. A few reactive lymphocytes, as well as a moderate amount of poikilocytes, rare polychromatophils, clumped platelets, and rare large platelets, were observed on all of the blood smears. Despite clumping and mild size variability, a manual estimate of platelet numbers was within normal limits. In addition, low to moderate amounts of amorphous to globular, purple to magenta, extracellular material was observed at the feathered edge and occasionally in the monolayer of the peripheral blood smears. Differentials for this material included an artifact of sampling or staining precipitate, a proteinaceous or mucinous material, or material associated with the use of lidocaine cream (Uber Numb 5% Lidocaine Numbing Cream, UberScientific, LLC, Lexington, KT)1 as part of pain management during blood draws. To verify that this material was associated with the use of lidocaine cream, the researchers provided the cream for further investigation. Whole blood in 3.0-mL K2-EDTA tubes from one dog and horse were obtained from excess samples. These samples were mixed gently and slowly warmed to ambient temperature. Four to five drops of each blood sample (dog and horse) were placed into two separate test tubes, and a small amount of the lidocaine cream (less than 0.5 g) was gently mixed with the blood. Another test tube not containing lidocaine cream was used as a control for each species. Peripheral blood smears were made from each test tube, stained with Modified Wright stain using the Siemens Hema-Tek 3000, and evaluated by the same clinical pathology resident (EA). As seen in Figures 2A and 3A, no globular to amorphous material is seen at the feathered edge. However, in Figures 2B and 3B, where the lidocaine cream was added to the peripheral blood, abundant amounts of globular to amorphous, purple to magenta material can be seen at the feathered edge. This material was morphologically indistinguishable from the unknown material identified on the blood smears from the research animals (Figure 4). Therefore, we concluded that the material at the feathered edge of the blood smears from these research dogs was consistent with the lidocaine cream used for pain management. Lidocaine cream Uber Numb 5% Lidocaine Numbing Cream, UberScientific, is a topical anesthetic commonly used to temporarily relieve pain, itching, or swelling associated with anorectal disorders as well as relieve pain during blood draws in humans.1 For the research dogs in this case, the cream was used for pain relief during the blood draw and to prevent negative behavioral reactions during future blood draws. The amorphous component of the material seen on the peripheral blood smear is somewhat similar to what is found on cytology samples having ultrasound gel contamination.2 This may be due to ultrasound gel and the lidocaine cream having similar ingredients (disodium EDTA, distilled water, and propylene glycol). However, the lidocaine cream has a more globular appearance than the granular, bright purple material associated with ultrasound gel. This article highlights the importance of knowing the characteristics of artifacts that can be seen in peripheral blood smears of animals. Different artifacts, such as lidocaine cream and ultrasound gel, will have different appearances on blood smears stained with Modified Wright stain, and knowing these characteristics will allow pathologists and technicians to identify these artifacts and relay findings to the clinicians. In conclusion, the globular to amorphous, purple to magenta material seen on the peripheral blood smears of the research dogs was due to lidocaine cream contamination of the blood sample during collection. The addition of lidocaine cream to blood samples, ex vivo, supports this conclusion. To the authors' knowledge, documentation of this finding has not been previously reported. The authors have no conflicts of interest.

Abstract 6700: Ligand-directed delivery of chemically modified miR-34a to prostate cancer: enhanced targeting and extended pharmacokinetics

Cancer Research · 2025-04-21

Abstract Prostate cancer is a leading cause of cancer-related mortality in men. Current therapeutic options include surgical intervention, chemotherapy, immunotherapy, and localized or systemic radiation therapy. However, advanced metastatic prostate cancers are challenging to treat, underscoring the critical need for more effective strategies. Prostate-specific membrane antigen (PSMA), a transmembrane glycoprotein, is overexpressed up to 1000-fold in ∼90% of prostate cancers. The high expression level of PSMA, coupled with highly specific targeting ligands, makes it a promising target for diagnostic and therapeutic applications. While various modalities can be delivered via PSMA, delivery of microRNAs has many advantages including the ability to overcome resistance often observed with single-agent treatments due to the ability of miRNAs to downregulate multiple genes simultaneously. Among the miRNAs with anti-cancer properties, miR-34a is among the most promising. Our work and that of others has determined that restoring miR-34a leads to tumor regression. Unfortunately, in vivo delivery challenges remain a bottleneck in advancing miR-34a to the clinic. These challenges can be subclassified into three key issues: 1. achieving specific delivery, 2. avoiding nuclease-mediated degradation, and 3. overcoming poor circulation half-life of the miRNA conjugates. Our lab is dedicated to overcoming these challenges. To address these issues, we developed a miRNA-34a vehicle-free strategy that delivers miR-34a to prostate cancer that comprises three critical attributes. Firstly, a peptidomimetic ligand (PSMA-617) was selected based on its selective specificity for PSMA binding, reducing delivery to non-tumorigenic cells. Secondly, the miR-34a is fully modified (FM-miR34a), containing an alternating pattern of 2′-O-methyl and 2′-fluoro modified sugars and phosphorothioate linkages at the 3′ and 5′ ends of each strand to reduce immunogenicity and to provide exonucleases resistance in-vivo. Thirdly, 4-(p-iodophenyl)butyric acid, a small molecule that exhibits high affinity for serum albumin, was added to the conjugate, enhancing the pharmacokinetic properties. Through binding to serum albumin, systemic circulation of the PSMA-617-miRNA-34a conjugate is prolonged, providing additional time to achieve receptor saturation, leading to increased bioavailability and therapeutic efficacy. Overall, our data indicates that bringing all three of these components together into a holist vehicle can enhance the clinical utility of miR-34a for treating prostate cancer. Citation Format: Digambar Kumar Waiker, Ahmed M. Abdelaal, Shreyas G. Iyer, Ikjot Singh Sohal, Esteban A. Orellana, Kasireddy Sudarshan, Kenan E. Ozcan, Andrea P. dos Santos, Philip S. Low, Andrea L. Kasinski. Ligand-directed delivery of chemically modified miR-34a to prostate cancer: enhanced targeting and extended pharmacokinetics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6700.

Oxidative stress induces plasma membrane phosphatidylserine externalization in canine erythrocytes in vitro, mitigated by thiol antioxidants

American Journal of Veterinary Research · 2025-01-08 · 1 citations

OBJECTIVE: To determine if oxidative stress induces phosphatidylserine (PS) externalization in canine erythrocytes and if exposure to antioxidants prevents such changes. METHODS: This was an in vitro, experimental study using 5 healthy, adult, purpose-bred research Beagles. Fresh EDTA-anticoagulated blood samples were collected from each dog, and erythrocytes were harvested. For objective 1, erythrocytes were exposed to the pro-oxidant agents tert-butyl hydroperoxide (TBHP) at 2, 3, or 4 mM or 2,2'-azobis(2-amidinopropane) dihydrochloride at 30, 40, or 50 mM. For objective 2, erythrocytes were exposed to 3 mM TBHP and the antioxidant N-acetylcysteine-amide (NACA) at various concentrations (0, 1, or 3 mM). Erythrocytes incubated with benzoylbenzoyl-ATP were used as positive control, whereas erythrocytes incubated with sodium chloride medium with 0.1% bovine serum albumin, DMSO, and NACA were used as negative controls. Erythrocytes were stained with allophycocyanin-conjugated Annexin V, and PS externalization was assessed by flow cytometry. The degree of PS externalization of each sample was recorded as median fluorescence intensity and percentage of PS positivity. RESULTS: TBHP at 3 and 4 mM caused increased PS externalization in canine erythrocytes. 2,2'-Azobis(2-amidinopropane) dihydrochloride at all concentrations caused increased PS externalization. N-acetylcysteine-amide at all concentrations prevented significant PS externalization measured by median fluorescence intensity and percentage of PS positivity from erythrocytes exposed to TBHP. CONCLUSIONS: Oxidative stress causes PS externalization in canine erythrocytes, and NACA ameliorates this effect. CLINICAL RELEVANCE: Future studies are needed to determine if increased PS externalization in erythrocytes occurs in dogs with immune-mediated hemolytic anemia and its role in promoting thromboembolism.

What Is Your Diagnosis? Esophageal and Gastric Washes in a Pet Moellendorff's Rat Snake

Veterinary Clinical Pathology · 2025-11-03

A 6-year-old female Moellendorff's rat snake (Orthriophis moellendorffi), weighing 0.8 kg, was presented to the Purdue University Veterinary Hospital for evaluation of open-mouth breathing, hypersalivation, and gurgling respiratory sounds. The owner reported that the snake had been quarantined in the serpentarium 1 week prior due to excessive oral mucus, though its appetite remained normal. The owner also disclosed maintaining approximately 50 snakes but provided no further husbandry details. On physical examination, the snake was alert and responsive but exhibited dyspnea. A laryngeal swab was collected for bacterial culture and sensitivity testing; after 5 days, aerobic culture yielded no growth. Ten days later, with no clinical improvement, the snake returned for reevaluation. Bloodwork was unremarkable, but radiographs revealed esophageal dilation with gas and increased soft tissue opacity caudal to the heart, suggestive of esophageal wall thickening or a mass. No radiographic evidence of respiratory disease was observed. Gastric and esophageal washes were obtained for cytologic analysis (Figure 1A,B). Both samples exhibited similar features. The samples were of low cellularity, consisting mainly of poorly preserved inflammatory cells and scant erythrocytes in the background. The leukocyte differential consisted of approximately 70% heterophils, 25% macrophages, and 5% lymphocytes. Rare basophils and plasma cells were identified on scanning, along with numerous unremarkable ciliated columnar cells and goblet cells. Notably, sparse thin-walled oval structures (25–35 μm wide × 45–50 μm long) were present. Frequently, a discernible, deeply basophilic granular material consistent with larval forms was seen inside these structures. The cytologic interpretation was mild heterophilic inflammation with larvated ova morphologically compatible with nematode eggs (likely Strongyloides /Rhabdias spp.). Smears of the esophageal and gastric washes underwent molecular testing at the University of Florida's Zoological Medicine and Wildlife Disease Laboratory. Genomic DNA was extracted and amplified via PCR using primers NC5 (5′-GTA GGT GAA CCT GCG GAA GGA TCA TT-3′) and NC2 (5′-TTA GTT TCT TTT CCT CCG CT-3′), which target conserved regions flanking the ITS1-5.8S-ITS2 ribosomal complex in nematodes [1]. The amplified PCR products were submitted for Sanger sequencing. Following quality trimming and assembly, a final consensus sequence of 581 bp was submitted to GenBank under accession number PQ303691. A comparison with the database revealed similarity to a previously described Strongyloides sp. (97.7%; GenBank entry: OQ107246.1) in a colony of captive colubrids [2]. Despite treatment with fenbendazole (for endoparasites) and metronidazole (for potential secondary bacterial infection), the snake's condition deteriorated, necessitating euthanasia. No postmortem examination or fecal analysis was conducted. Strongyloides are nematodes belonging to the family Strongyloididae [3]. At least 50 species have been described within this genus [4], infecting mammals, birds, reptiles, and amphibians [5]. Transmission occurs when larvae penetrate the host's skin or oral mucosa, enter systemic circulation, and migrate to the lungs [3]. They access the oral cavity through the trachea, where they can be ingested and subsequently enter the gastrointestinal tract [3]. However, both the Strongyloididae and Rhabdiasidae families have the potential to cause clinical signs associated with respiratory disease due to larval migration or adult parasites residing in the respiratory tissue, respectively [3]. Infected snakes often exhibit open-mouth breathing, mucous accumulation around the nares and glottis, and may develop severe pneumonia with secondary bacterial infection [3]. Because both families produce morphologically similar larvated eggs in feces [3], molecular analysis was critical for an accurate etiologic diagnosis in this case. The amplified sequence showed the highest similarity to a potential novel Strongyloides species recently identified in captive colubrids from central Florida, USA [2]. In that study, affected snakes frequently demonstrated esophageal thickening, with nematodes sometimes visible in the esophagus and stomach at various life stages [2]. The esophageal soft tissue opacity observed radiographically likely represented a helminth infection focus, though this couldn't be confirmed histologically. The snake's clinical signs may have reflected tracheal compression by the esophageal mass or dysphagia misinterpreted as respiratory distress. Although Strongyloides infections are common in snakes, this represents the first reported case in O. moellendorffi. While not contradictory, the diagnosis was unexpectedly achieved through cytologic examination of esophageal and gastric washes. The sequence's strong similarity to a potentially novel and highly pathogenic Strongyloides species [2] raises concerns about transmission risks in captive environments. This finding underscores the value of molecular methods for identifying emerging parasitic threats in reptile collections. The authors would like to acknowledge Dr. Robert J. Ossiboff for providing the sequences from the amplified material. The authors declare no conflicts of interest.

Abstract 1439: Gene expression profiling of canine diffuse large B-cell lymphoma: Insights from RNA sequencing

Cancer Research · 2025-04-21

Abstract Introduction: Diffuse large B-cell lymphoma (DLBCL) is a common and aggressive form of lymphoma in dogs, closely resembling human DLBCL in its clinical behavior and molecular features. While CHOP chemotherapy is the standard treatment, many dogs experience poor responses or early relapse, underscoring the need for a more comprehensive understanding of the disease’s molecular underpinnings. This study aimed to investigate the gene expression profiles in canine DLBCL to identify potential biomarkers and therapeutic targets. Materials and Methods: Fresh frozen lymph node samples were collected from six dogs diagnosed with DLBCL and four healthy controls. Total RNA was extracted, and RNA sequencing (RNA-seq) was performed to profile global gene expression. Differentially expressed genes were identified using DESeq2, and principal component analysis (PCA) was used to distinguish expression patterns between groups. Key findings were validated using quantitative PCR (qPCR) to confirm the dysregulation of selected genes. Results: RNA-seq analysis revealed 3, 156 differentially expressed genes, including 1, 418 upregulated and 1, 738 downregulated in DLBCL samples. PCA showed distinct clustering between DLBCL and healthy groups, confirming significant gene expression divergence. qPCR analysis validated these results, highlighting the upregulation of genes such as NIT2 (fold change: 3.145; FDR: 0.0074), MYC (fold change: 3.086; FDR: 0.0494), and CDK4 (fold change: 2.151; FDR: 0.0331), suggesting their involvement in tumorigenesis and disease progression. Conversely, genes such as AICDA (fold change: -4.338; FDR: 0.0284), BCL6 (fold change: -2.352; FDR: 0.0469) and CDH1 (fold change: -1.699; FDR: 0.0469) were significantly downregulated, indicating potential suppression of tumor-suppressive pathways. Conclusion: This study provides valuable insights into the molecular mechanisms underlying canine DLBCL. The identification of differentially expressed genes and pathways highlights novel biomarkers and potential therapeutic targets. Moreover, the findings demonstrate the translational relevance of canine DLBCL as a comparative model for human lymphoma, advancing our understanding of both veterinary and human oncology. This abstract was edited and formatted with the assistance of generative artificial intelligence (Chatgpt) to enhance clarity and presentation. Citation Format: Nelly Elshafie, Ekramy SayedAhmed, Michael O. Childress, Andrea Pires dos Santos. Gene expression profiling of canine diffuse large B-cell lymphoma: Insights from RNA sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1439.

Hemotropic mycoplasmas (hemoplasmas) in indigenous populations and their dogs living in reservation areas, Brazil

Scientific Reports · 2025-03-07 · 9 citations

Although hemoplasma infection has been widely described in animals, a few studies have been conducted involving human populations, mostly as case reports. This was a cross-sectional epidemiological study that accessed hemoplasma infection in individuals and dogs from ten Indigenous communities of southern and southeastern Brazil. A total of 23/644 (3.6%) individuals of ten Indigenous communities tested positive to hemoplasmas by quantitative polymerase chain reaction (qPCR) (cycle threshold; Ct ≤ 34.4), with 3/644 (0.5%) Mycoplasma haemocanis detection. In addition, 91/416 (21.9%) dogs were positive to hemoplasmas by qPCR, with 54/91 (59.3%) for M. haemocanis, 27/91 (29.7%) for Candidatus Mycoplasma haematoparvum, and 10/91 (11.0%) for both. Molecular diagnosis of M. haemocanis in Indigenous people herein may be consequence of daily close contact with dogs and different potential vectors. Although apparently healthy individuals, hemoplasma infection should be considered as differential diagnosis in likely overexposed populations, such as Indigenous individuals.

EDTA as a potential obstacle to the detection of trypanosomes in anuran blood samples using Woo's technique

Veterinary Parasitology Regional Studies and Reports · 2025-11-01