Characterisation of the pruritus responses and pruritic behaviours in an interleukin 31-induced canine model of pruritus

BACKGROUND

Intravenous administration of interleukin (IL)-31 in healthy dogs has been used as a model to assess antipruritic drugs. However, there is no known in-depth characterisation of pruritic behaviours, and the repeatability of the IL-31-induced pruritus in the individual dogs is currently unknown.

OBJECTIVES

To evaluate the immediate/delayed pruritus responses and the pruritic behaviours observed in the IL-31-induced pruritic model in healthy dogs after repeated IL-31 injections.

ANIMALS

Fifteen healthy laboratory beagles.

METHODS

All dogs were video-recorded for 270 min after two intravenous recombinant IL-31 injections (1.75 μg/kg) and vehicle (phosphate-buffered saline, control) injections, respectively; interventions were randomised and performed with a 2 week wash-out period. Two blinded investigators reviewed the pruritic behaviours of all video recordings.

RESULTS

Both canine IL-31 (IL-31_01, IL-31_02) injections significantly increased pruritic seconds and categorical minutes ('YES'/'NO' behaviour per discrete 1 min interval) in healthy dogs compared with both vehicle groups (Vehicle_01, Vehicle_02). The second intravenous canine IL-31 (IL-31_02) administered 14 days after the first IL-31 injection induced a significant increase in pruritic seconds (p = 0.021) and not pruritic categorical minutes (p = 0.231). An increase in pruritic seconds was observed in both IL-31 groups in the first 30 min post-administration, while there was no significant difference between IL-31 and vehicle groups.

CONCLUSIONS AND CLINICAL RELEVANCE

In conclusion, intravenous IL-31 reproducibly induces itch responses in dogs. Future evaluations of the canine IL-31 pruritic model should assess total pruritic behaviours in seconds rather than using a biased 'YES/NO' behaviour per 1 min scoring system.

Microarray Gene Expression Analysis of Lesional Skin in Canine Pemphigus Foliaceus

Canine pemphigus foliaceus (PF) is considered the most common autoimmune skin disease in dogs; the mechanism of PF disease development is currently poorly understood. Therefore, this study aimed to characterize the molecular mechanisms and altered biological pathways in the skin lesions of canine PF patients. Using an RNA microarray on formalin-fixed, paraffin-embedded samples, we analyzed the transcriptome of canine PF lesional skin (n = 7) compared to healthy skin (n = 5). Of the 800 genes analyzed, 420 differentially expressed genes (DEGs) (p < 0.05) were found. Of those, 338 genes were significantly upregulated, including pro-inflammatory and Th17-related genes. Cell type profiling found enhancement of several cell types, such as neutrophils, T-cells, and macrophages, in PF skin compared to healthy skin. Enrichment analyses of the upregulated DEGs resulted in 78 statistically significant process networks (FDR < 0.05), including the Janus kinase signal transducer and activator of transcription (JAK-STAT) and mitogen-activated protein kinase (MAPK) signaling. In conclusion, canine PF lesional immune signature resembles previously published changes in human pemphigus skin lesions. Further studies with canine PF lesional skin using next-generation sequencing (e.g., RNA sequencing, spatial transcriptomics, etc.) and the development of canine keratinocyte/skin explant PF models are needed to elucidate the pathogenesis of this debilitating disease.

Characterization of the serum and skin inflammatory profile in canine pemphigus foliaceus using multiplex assay and quantitative real-time polymerase chain reaction (qRT-PCR)

Canine pemphigus foliaceus (PF) is a common autoimmune skin disease characterized by autoantibodies binding to epithelial adhesion molecules resulting inflammatory response. The immune network of cytokine and chemokine abnormalities that characterize the immune response in canine PF are poorly explored. This study evaluated serum and lesional skin cytokine and chemokine profiles of dogs diagnosed with PF compared to healthy control dogs. Serum samples obtained from 11 PF dogs and 16 healthy control dogs were analyzed using commercially available canine multiplex assay for 13 biomarkers (Canine Milliplex assay). Eight lesional skin samples from seven PF dogs and five healthy site-matched samples from five healthy dogs were evaluated for 20 immune markers using quantitative real-time PCR. Immunomodulating medications were suspended for at least four weeks in all dogs before obtaining serum and skin samples. PF patients showed significantly higher serum concentrations of tumor necrosis factor-α, interleukin (IL)- 6, IL-8, IL-18, CCL2, KC-like, and granulocyte-macrophages colony-stimulating factor when compared to healthy controls (Mann-Whitney U test; p < 0.05 for all). Lesional PF skin exhibited significant expression and upregulation of pro-inflammatory/T helper (Th1) 1 markers IL-1β, MX1, GZMB, OAS1, and IFN-γ as well as Th2 cytokines IL-13, IL-33, TSLP, IL-31 and Th17/22 markers IL-17A and IL-22 (Mann-Whitney U test; p < 0.05 for all). Taken together, the findings from this study describe the role of numerous cytokines and chemokines associated with immune response in the skin and serum of canine PF patients. Further larger-sample proteomics and RNA-sequencing transcriptomics studies are needed to understand the immune pathogenesis of canine PF skin lesions.

Establishment of an Intradermal Canine IL-31-Induced Pruritus Model to Evaluate Therapeutic Candidates in Atopic Dermatitis

Pruritic models in healthy dogs utilizing intravenous administration of interleukin 31 (IL-31) bypass the "natural" itch sensation in AD, which is initiated by pruriceptive primary afferent neurons in the skin. This study aimed to evaluate the immediate/delayed pruritus responses and the pruritic behaviors observed in an intradermal IL-31-induced pruritic model of healthy dogs and the anti-pruritic effect of oclacitinib on said model. In Phase 1, all the dogs were randomized and video-recorded for 300 min after intradermal canine recombinant IL-31 injections (1.75 µg/kg) and vehicle (phosphate-buffered saline) injections. In Phase 2, all the dogs received oral oclacitinib (0.4-0.6 mg/kg, twice daily for 4 consecutive days and once daily on day 5), with the intradermal IL-31 injection performed on day 5. Two blinded investigators reviewed the pruritic behaviors in all the video recordings. Intradermal IL-31 administration to healthy dogs caused a significant increase in the total (p = 0.0052) and local (p = 0.0003) seconds of pruritic behavior compared to the vehicle control. Oral oclacitinib administration significantly reduced the total (p = 0.0011) and local (p = 0.0156) intradermal IL-31-induced pruritic seconds; there was no significant difference in pruritic seconds between the vehicle and oclacitinib within the IL-31 groups. Significant delayed pruritic responses at 150-300 min after IL-31 injections were observed, and intradermal IL-31 failed to induce acute itch (first 30 min). Intradermal injection of IL-31 induces delayed itch responses in dogs that are diminished by the effect of oclacitinib, an oral JAK inhibitor.

Seasonal Investigation of Anaplasma marginale Infection in Pakistani Cattle Reveals Hematological and Biochemical Changes, Multiple Associated Risk Factors and msp5 Gene Conservation

Bovine anaplasmosis is a tick-borne disease caused by an obligate intercellular Gram-negative bacterium named Anaplasma (A.) marginale. In this study, we report the seasonal prevalence, potentially associated risk factors and phylogeny of A. marginale in cattle of three different breeds from Multan District, Southern Punjab, Pakistan. A total of 1020 blood samples (crossbred, n = 340; Holstein Friesian, n = 340; and Sahiwal breed, n = 340) from apparently healthy cattle were collected on a seasonal basis from March 2020 to April 2021. Based on PCR amplification of the msp5 partial sequence, overall, the A. marginale prevalence rate was estimated at 11.1% (113/1020) of the analyzed cattle samples. According to seasons, the highest prevalence rate was observed in autumn (16.5%), followed by winter (10.6%) and summer (9.8%), and the lowest was recorded in the spring (7.5%). The crossbred and Sahiwal cattle were the most susceptible to A. marginale infection, followed by Holstein Friesian cattle (7.9%). Analysis of epidemiological factors revealed that cattle reared on farms where dairy animals have tick loads, dogs coinhabit with cattle and dogs have tick loads have a higher risk of being infected with A. marginale. In addition, it was observed that white blood cell, lymphocyte (%), monocyte (%), hematocrit, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentrations were significantly disturbed in A. marginale-positive cattle compared with non-infested cattle. Genetic analysis of nucleotide sequences and a phylogenetic study based on msp5 partial sequencing demonstrated that this gene appears to be highly conserved among our isolates and those infecting apparently healthy cattle from geographically diverse worldwide regions. The presented data are crucial for estimating the risk of bovine anaplasmosis in order to develop integrated control policies against bovine anaplasmosis and other tick-borne diseases infecting cattle in the country.

Morphological description of Pintomyia (Pifanomyia) veintemillasi n. sp., a new sand fly species from the sub-Andean region of Bolivia

Background

Most sand fly species are located in the Americas; some act as vectors of leishmaniasis and other human diseases. In Bolivia, about 25% of Neotropical species have been identified, and only a few have been implicated as vectors of cutaneous and visceral leishmaniasis. A new species of anthropophilic sand fly from the sub-Andean region of Alto Beni is described herein.

Methods

A large systematic entomological survey was carried out in a subtropical humid forest located in the Marimonos mountain range, at around 900 m altitude, in the municipality of Palos Blancos, Sud Yungas Province, Department of La Paz, Bolivia. Sand flies were captured over a period of 26 months between January 1982 and February 1984, at the ground and canopy level, using both CDC light traps and protected human bait. A total of 24,730 sand flies were collected on the ground, distributed in 16 species, and 3259 in the canopy, with eight species. One of these species was labeled as Pintomia (Pifanomyia) nevesi, although certain morphological features allowed us to doubt that it was that taxon. To define the identity of this sand fly, a re-evaluation (this work) was recently carried out through morphological analyses and measurements of the available specimens mounted on Euparal, previously labeled as Pi. (Pif.) nevesi.

Results

Based on the morphological traits and measurements, the re-evaluated specimens were definitively identified as a new sand fly species, Pintomyia (Pifanomyia) veintemillasi, closely related to Pi. (Pif.) nevesi and Pintomyia (Pifanomyia) maranonensis within the Evansi series. This new sand fly was the third most numerous anthropophilic species at the floor (6.2%) and the second most numerous anthropophilic at the canopy (35.1%).

Conclusions

A new anthropophilic sand fly species is described as Pi. (Pif.) veintemillasi n. sp. This sand fly species was caught at about 900 m altitude in the Marimonos mountain range, a highly endemic area for cutaneous and mucosal leishmaniasis due to Leishmania (Viannia) braziliensis. Therefore, this species could be involved in the leishmaniasis transmission in the sub-Andean foothills of Alto Beni, Department of La Paz, Bolivia.

Graphical Abstract

Risk factor analysis for the prevalence of gastrointestinal parasites found in large ruminants in Lower Dir Khyber Pakhtunkhwa Pakistan

The present study was designed to investigate the prevalence of gastrointestinal (GI) parasites in cattle and buffaloes of Lower Dir Khyber Pakhtunkhwa, Pakistan. The presence of the eggs, cysts, and oocysts of GI parasites in fecal samples were detected using direct smear methods and concentration techniques including floatation, centrifugation, and sedimentation. Identification of recovered fecal stages were determined by morphology using size and appearance of the recovered eggs, cysts, and oocysts. A total of 314 fecal samples were collected from the different Tehsils (Administrative Districts) and analyzed through microscopy. A higher prevalence was observed in the buffalo than the cow population. A total of 184 samples were positive for GI parasites of which 109/196 (55.61%) were from cattle, whereas 75/118 (63.55%) were from buffaloes. The minimum number of strongyle eggs detected in all the samples were 136.39 eggs/g (EPG). The mean EPG in cattle was 143.30 and 122.56 in buffaloes. The open-source water prevalence of GI parasites was higher than the other sources in cattle and the second highest after tap water in buffaloes. The seasonal prevalence of GI parasites ranged from 32.39% (23/71), in spring to 68.8% (86/125) in summer in cattle. In was For buffaloes the infection prevalence was 52.94% (27/51) and 71.64% (48/67) in spring and summer, respectively. Gastrointestinal parasites are a serious problem in cattle and buffaloes in the lower district of Dir Khyber Pakhtunkhwa Pakistan. In general, the burden of parasitic infection was low in most animals that received previous anti-parasitic treatment.

Epidemiology and molecular characterization of Theileria annulata in cattle from central Khyber Pakhtunkhwa, Pakistan

Theileria annulata is a tick-borne hemoprotozoan parasite responsible for tropical theileriosis in the bovine population, which causes substantial economic losses to the livestock sector. The present study has investigated, characterized, and shaped epidemiologic and phylogenetic profiles of T. annulata infection in the cattle population of central Khyber Pakhtunkhwa, Pakistan. A total of 600 blood samples were collected from cattle. Microscopy and PCR (18S rRNA taxonomic marker) assays were performed to detect T. annulata infection in cattle from the study area. The overall relative prevalence rates of T. annulata in the examined cattle population were 12.8% (microscopy) and 23.7% (PCR). District-wise analysis (microscopy/PCR) showed that cattle from district Mardan were found more infected (16.0%/28.0%), as compared to cattle from district Charsadda (13.5%/25.5%) and district Peshawar (9.0%/17.5%). Based on host demographic and ecological parameters analysis, theileriosis was found to be higher in young, female, crossbred, freely grazing, tick-infested, and irregular/no acaricides treated cattle. The univariate logistic analysis showed that host age, tick infestation, acaricides use, and feeding method were significant risk factors (P<0.05) whereas multivariate analysis indicated that host age, gender, tick infestation, acaricidal application, and feeding method were potential risk factors (P<0.05) for tropical theileriosis in the cattle population. Phylogenetic and sequence analysis showed that T. annulata 18S rRNA isolates shared homology and phylogeny with other isolates from Asia and Europe. This study has addressed the epidemiology and phylogeny of T. annulata circulating in bovid in the study area where gaps were still present. These findings will serve as a baseline and will facilitate future large-scale epidemiological investigations on tropical theileriosis in the cattle population at a national level.

Biosafety at Home: How to Translate Biomedical Laboratory Safety Precautions for Everyday Use in the Context of COVID-19

Population adoption of social distancing measures during the COVID-19 pandemic is at times deficient, increasing the risk of SARS-CoV-2 transmission. Healthcare workers and those living in areas of intense transmission may benefit from implementing biosafety measures in their daily lives. A mixed-methods approach, combining components of single negotiation text and the Delphi method, was used to create a COVID-19 biosafety-at-home protocol. A consensus building coordinator liaised with 12 experts to develop the protocol over 11 iterations. Experts had more than 200 years of combined experience in epidemiology, virology, infectious disease prevention, and public health. A flyer, created from the final protocol, was professionally designed and initially distributed via social media and institutional websites/emails in Ecuador beginning on May 2, 2020. Since then, it has been distributed in other countries, reaching ∼7,000 people. Translating research laboratory biosafety measures for the home/street environment might be challenging. The biosafety-at-home flyer addresses this challenge in a user-friendly format.

[Venezuelan consensus guidelines on the use of magnetic resonance in diagnosis and follow up of patients with multiple sclerosis]

INTRODUCTION

The clinical use of magnetic resonance (MR) in patients with multiple sclerosis (MS) has advanced markedly over the past few years. Several groups around the world have developed consensus guidelines about the role of MR in MS at diagnosis and during follow up. However, in some regions is difficult to extrapolate the recommendations.

AIM

To provide recommendations for the implementation of MR in MS patients at diagnosis and follow up in Venezuela.

DEVELOPMENT

A group of experts from Venezuela that included neurologists and radiologists, by using the online surveys methodology as well as face to face meetings developed the intended consensus for the use of MR during the diagnosis and follow up of MS patients in Venezuela. Seventeen recommendations were established based on published evidence and the expert opinion. Recommendations focused on the role of conventional MR techniques and brain atrophy measurement in MS patients both at diagnosis and during follow-up.

CONCLUSIONS

The recommendations of this consensus guidelines attempts to optimize the health care and management of patients with MS in Venezuela.

Relationship between splenic sequestration and thrombocytopenia in Trypanosoma evansi infection in rats

Trypanosoma evansi infections in domestic animals are characterized by anemia and thrombocytopenia. The cause of the platelets decrease is unknown, but researchers suggest that thrombocytopenia may result from damage of the bone marrow, reduced survival of platelets, auto-immune thrombocytopenia, disseminated intravascular coagulation and splenic sequestration. Some of these causes have already been tested by our research group and found to be unrelated. Therefore, this study has the objective of testing the hypothesis that splenic sequestration might be responsible for thrombocytopenia in T. evansi-infected rats. A total of 28 rats assigned to four groups were used in the experiment. Group A rats were splenectomized and infected with T. evansi, group B rats were infected with T. evansi, group C rats were splenectomized, but not infected and group D rats were normal controls. Five days post-infection all rats were anesthetized and blood was collected in order to measure the number of circulating platelets, fibrinogen levels, prothrombin time (PT) and activated partial thromboplastin time (aPTT). The spleens of groups B and D were weighed at necropsy. The infected animals (groups A and B) showed a significant reduction in platelets and increased PT and aPTT when compared to negative control groups (groups C and D). Animals from group A showed increased levels of fibrinogen. The mean weight of spleen differed between group B (2.62g) and group D (0.55g). It was concluded that there is no relationship between thrombocytopenia and splenic sequestration in infection by T. evansi.

Pathophysiology of the vascular wall and its relevance for cerebrovascular disorders in aged rodents

Chronic hypertension and cerebral amyloid angiopathy (CAA) are the main pathologies which can induce the rupture of cerebral vessels and intracerebral hemorrhages, as a result of degenerative changes in the vascular wall. A lot of progress has been made in this direction since the successful creation of the first mouse model for the study of Alzheimer's disease (AD), as the spectrum of AD pathology includes a plethora of changes found in pure cerebrovascular diseases. We describe here some of these mouse models having important vascular changes that parallel human AD pathology, and more importantly, we show how these models have helped us understand more about the mechanisms that lead to CAA formation. An important cellular event associated with reduced structural and functional recovery after stroke in aged animals is the early formation of a scar in the infarcted region that impairs subsequent neural recovery and repair. We review recent evidence showing that the rapid formation of the glial scar following stroke in aged rats is associated with premature cellular proliferation that originates primarily from the walls of capillaries in the corpus callosum adjacent to the infarcted region. After stroke several vascular mechanisms are turned-on immediately to protect the brain from further damage and help subsequent neuroregeneration and functional recovery. Although does occur after stroke, vasculogenesis is overshadowed in its protective/restorative role by the angiogenesis and arteriogenesis. Understanding the basic mechanisms underlying functional recovery after cerebral stroke in aging subjects is likely to yield new insights into the treatment of brain injury in the clinic.

Mesostructure design with gemini surfactants: supercage formation in a three-dimensional hexagonal array

At low temperatures, liquid crystal-like arrays made up of inorganic-cluster and organic molecular units readily undergo reversible lyotropic transformations. Gemini surfactants, with two quaternary ammonium head groups separated by a methylene chain of variable length and with each head group attached to a hydrophobic tail, can be used to control organic charge sitting relative to the bivariable hydrophobic tail configurations. This approach has led to the synthesis of a mesophase (SBA-2) that has three-dimensional hexagonal (P6(3)/mmc) symmetry, regular supercages that can be dimensionally tailored, and a large inner surface area. This mesostructure analog of a zeolite cage structure does not appear to have a lyotropic surfactant or lipid liquid crystal mesophase counterpart. Through the modification of gemini charge separation and each of the two organic tails, these syntheses can be used to optimize templating effects, including the synthesis of MCM-48 at room temperature.

Fluorescence microscopy as a tool for in situ life detection

The identification of extant and, in some cases, extinct bacterial life is most convincingly and efficiently performed with modern high-resolution microscopy. Epifluorescence microscopy of microbial autofluorescence or in conjunction with fluorescent dyes is among the most useful of these techniques. We explored fluorescent labeling and imaging of bacteria in rock and soil in the context of in situ life detection for planetary exploration. The goals were two-fold: to target non-Earth-centric biosignatures with the greatest possible sensitivity and to develop labeling procedures amenable to robotic implementation with technologies that are currently space qualified. A wide panel of commercially available dyes that target specific biosignature molecules was screened, and those with desirable properties (i.e., minimal binding to minerals, strong autofluorescence contrast, no need for wash steps) were identified. We also explored the potential of semiconductor quantum dots (QDs) as bacterial and space probes. A specific instrument for space implementation is suggested and discussed.

Photoconductive optically driven deformable membrane under high-frequency bias: fabrication, characterization, and modeling

The fabrication and characterization of an optically addressable deformable mirror for a spatial light modulator are described. Device operation utilizes an electrostatically driven pixelated aluminized polymeric membrane mirror supported above an optically controlled photoconductive GaAs substrate. A 5 mum thick grid of patterned photoresist supports the 2 mum thick aluminized Mylar membrane. A conductive ZnO layer is placed on the backside of the GaAs wafer. Similar devices were also fabricated with InP. A standard Michelson interferometer is used to measure mirror deformation data as a function of illumination, applied voltage, and frequency. The device operates as an impedance distribution between two cascaded impedances of deformable membrane substrate, substrate, and electrode. An analysis of device's operation under several bias conditions, which relates membrane deformation to operating parameters, is presented.

Meconial peritrophic matrix structure, formation, and meconial degeneration in mosquito pupae/pharate adults: histological and ultrastructural aspects

The noncellular peritrophic matrix (PM) that forms around the food bolus in the midgut of many arthropod species may influence the fate of ingested microbes. In mosquitoes, PMs have been identified in the pupal as well as larval and adult stages. In pupae, the PMs surround the meconium, the sloughed larval midgut epithelium. Meconial PM1 (MPM1) forms early in the pupal stadium, and a second meconial PM (MPM2) sometimes forms around the time of adult emergence. A recent study suggests that MPMs contribute to the sterilization of the adult midgut by sequestering microorganisms ingested during the larval stage, which, along with remaining meconial material, are egested after adult emergence. We have compared MPM1 formation and patterns of meconial degeneration in representative species in five mosquito genera and identified a temporal association between MPM1 formation, meconial degeneration, and apolysis. Ultrastructural study of MPM1 and MPM2 in Aedes aegypti (L.) revealed that MPM1 seems to be structurally different from either the larval or adult PMs, whereas MPM2 more closely resembles PM formed around a bloodmeal in adult females. Our results are consistent with the microbial sequestration role.