Mercury immunotoxicity in the brown watersnake (Nerodia taxispilota): An in vitro study.

Mercury (Hg) is a heavy metal that enters the environment through natural and anthropogenic means. Once in the environment, Hg can biomagnify in food webs and is known to cause immunotoxic effects to wildlife. Compared with other vertebrates, knowledge of the reptilian immune system is lacking, especially in snakes. Further, even less is known about the impact of environmental contaminants on snake immunity. This gap in knowledge is largely due to an absence of established immune-based assays or specific reagents for these species. In this study, brown watersnakes (Nerodia taxispilota; n = 23) were captured on the Savannah River (Augusta, Georgia, USA), weighed, measured, bled, and released. Peripheral blood leukocytes (24 h old) were enriched and evaluated with an established mammalian in vitro lymphocyte proliferation assay. Enriched leukocytes were then exposed to mercury chloride (HgCl2 ) at 3.75, 37.5, and 75 µM. Total mercury (THg) in whole blood was also quantified. Snake peripheral blood leukocyte enrichment yielded >90% lymphocytes with viabilities averaging >70%. Exposure to HgCl2 resulted in significant dose-dependent suppression of proliferative responses relative to spontaneous proliferation at 37.5 and 75 µM (both p ≤ 0.01) but not 3.75 µM (p = 0.99). Mean ± 1 SE concentration of THg in whole blood was 0.127 ± 0.027 mg/kg (wet weight). Based on the in vitro findings with HgCl2 , snakes in systems with heavy Hg pollution may be at risk of immunosuppression, but N. taxispilota at the site in this study appear to be at low risk.

Brief Communication: Predictive Value of Veterinary Student Application Data for Performance in Clinical Year 4.

Student application packages for admission to the University of Georgia College of Veterinary Medicine currently include the following information: undergraduate grade point average (GPA), GPA in science courses, GPA in non-science courses, GPA for the last 45 hours (GPALast45hrs), Graduate Record Examination Quantitative and Verbal Reasoning (GRE-QV) score, GRE Analytical Writing (GRE-AW) score, and grades for 10 required prerequisite courses. From these data, an academics score of up to 70 points is calculated. Faculty reviewers also score each applicant up to a maximum of 30 points (FileScore), giving a total possible score of 100 points. Previous analyses demonstrated that the file score and academic variables are significantly related to first-year GPA of veterinary students; however, it is unknown how these variables relate to performance in clinical rotations. The present study pooled the two most recent graduating classes to compare each academic score component to student clinical rotation grades received during year 4 (CGrYr4) in the teaching hospital. Only one component of the student application packages-the pre-admission GRE-QV score-significantly correlated with CGrYr4.

Peripheral blood hematology, plasma biochemistry, and the optimization of an in vitro immune-based assay in the brown watersnake (Nerodia taxispilota).

Reptiles represent a phylogenetic lineage that provides a unique link between ectothermic anamniotes and endothermic amniotes. Compared to mammalian and avian species, our understanding of the reptilian immune system is greatly lacking. This gap in knowledge is largely due to an absence of established immune-based assays or specific reagents for these species. In the present study, brown watersnakes (Nerodia taxispilota) were live-captured in the wild, sexed, weighed, measured, bled via the caudal vein, and released. At 24 hr post-collection, peripheral blood leukocytes were enriched and evaluated with an established mammalian in-vitro lymphocyte proliferation assay. Snake peripheral blood leukocyte enrichment yielded >90% lymphocytes with viabilities averaging 81.5%. Baseline physiologic data for N. taxispilota, including hematology and total solids, leukocyte differentials, cell recovery, and plasma biochemistry, were also collected. Cells cultured with Concanavalin A exhibited significantly increased proliferation at both 72 and 96 hr. These preliminary results show that enriched peripheral blood from wild-caught N. taxispilota provides a sufficient yield of leukocytes that can be cultured and functionally evaluated using a standard mammalian in-vitro immune-based assay.

Characterisation of the serum cytokine profile in feline atopic skin syndrome.

BACKGROUND: Feline atopic skin syndrome (FASS) is a pruritic and inflammatory skin disease commonly encountered in cats. Three previous reports evaluated cytokine immune activation in cats diagnosed with feline allergic dermatitis. However, no significant upregulations were observed in allergic cats compared to healthy controls. HYPOTHESIS/OBJECTIVE: To evaluate differences in the serum cytokine profile of cats diagnosed with FASS compared to healthy cats, and correlate serum markers with the extent of FASS skin disease using clinical scoring systems. ANIMALS: Thirteen client-owned FASS cats and 12 healthy control cats. METHODS AND MATERIALS: Thirteen cytokine and chemokines from the serum of FASS cats and healthy controls were analysed using a commercially available feline-specific multiplex assay. RESULTS: Patients with FASS had a significant increase in serum concentrations of interferon-gamma (IFN-γ), interleukin (IL)-2, IL-13 and IL-18. In addition, cytokine/chemokines involved in inflammation and chemotaxis [IL-8, C-C Motif Chemokine Ligand (CCL)5, CCL2 and CXCL12], as well as growth factors, stem cell factor and Fms-related tyrosine kinase 3 ligand (Flt3L), also were significantly elevated. A significant positive correlation (r = 0.64) between the serum levels of Flt3L and Scoring Feline Allergic Dermatitis (SCORFAD) score was observed. CONCLUSIONS: These results demonstrate the activation of a broad array of immune secretory cytokines in the serum of cats with FASS, which are largely associated with a mixed Th1 and Th2 inflammatory response along with specific growth factors. Further larger-sample studies are needed to assess the modulation of serum biomarkers in FASS by pharmacological/therapeutic interventions.

Oral dexamethasone sodium phosphate solution significantly reduces pruritus and clinical lesions in feline hypersensitivity dermatitis: an open-label study.

BACKGROUND: There are no liquid oral glucocorticoids labelled for management of pruritus and clinical lesions of feline hypersensitivity dermatitis (feline HD). HYPOTHESIS: First, to demonstrate that dexamethasone sodium phosphate (DexSP, DexajectSP, Henry Schein; Dublin, OH, USA; 4 mg/mL), an intravenous glucocorticoid, can be absorbed by healthy cats when administered orally. Second, to demonstrate the efficacy of orally administered DexSP for reducing pruritus and clinical lesions in patients with feline HD. ANIMALS: Seven healthy and 12 client-owned cats with HD. METHODS AND MATERIALS: Healthy cats were administered a single dose of 0.2 mg/kg DexSP p.o. and serum concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Feline HD patients were assessed with SCORing Feline Allergic Dermatitis (SCORFAD) and pruritus Visual Analog Scale (pVAS) at Visit 1 (V1) and after 20-31 days of receiving 0.2 mg/kg/day DexSP p.o. (V2). Complete blood cell counts, serum chemistry profile, and urinalysis were performed in 50% of feline HD patients at both visits. RESULTS: Healthy cats had detectable serum concentrations of DexSP following oral administration; concentrations ranged from 0.7 to 92.3 ng/mL. Feline HD patients showed significant decreases in SCORFAD and pVAS scores from V1 to V2. CONCLUSIONS: DexSP was absorbed when administered orally to healthy cats and 0.2 mg/kg/day DexSP is an efficacious dose to rapidly improve the pruritus and clinical lesions associated with feline HD.

Snakes as Novel Biomarkers of Mercury Contamination: A Review.

Mercury (Hg) is an environmental contaminant that has been reported in many wildlife species worldwide. The organic form of Hg bioaccumulates in higher trophic levels, and thus, long-lived predators are at risk for higher Hg exposure. Although ecological risk assessments for contaminants such as Hg include pertinent receptor species, snakes are rarely considered, despite their high trophic status and potential to accumulate high levels of Hg. Our current knowledge of these reptiles suggests that snakes may be useful novel biomarkers to monitor contaminated environments. The few available studies show that snakes can bioaccumulate significant amounts of Hg. However, little is known about the role of snakes in Hg transport in the environment or the individual-level effects of Hg exposure in this group of reptiles. This is a major concern, as snakes often serve as important prey for a variety of taxa within ecosystems (including humans). In this review, we compiled and analyzed the results of over 30 studies to discuss the impact of Hg on snakes, specifically sources of exposure, bioaccumulation, health consequences, and specific scientific knowledge gaps regarding these moderate to high trophic predators.

Resistin concentrations in serum and stifle synovial fluid from normal and cruciate deficient dogs with osteoarthritis.

OBJECTIVE: To compare synovial fluid (SF) resistin concentrations in healthy dogs to dogs with osteoarthritis (OA) secondary to cranial cruciate ligament (CrCL) injury and to correlate resistin concentrations with body condition score (BCS) and evaluate resistin release from peripheral blood mononuclear cells (PBMC) and adipocytes. STUDY DESIGN: Controlled, prospective, clinical study ANIMALS: Thirty-nine client-owned dogs, 13 healthy and 26 with secondary OA, were enrolled. Blood was collected from six healthy purpose-bred dogs for PBMC culture. An additional six mixed-breed dogs were used for adipocyte collection and culture. METHODS: Resistin concentrations were measured with a canine-specific enzyme-linked immunoabsorbent assay. Resistin was compared between healthy SF and OA SF with Student's t test. Correlation of resistin concentrations to BCS was performed. Peripheral blood mononuclear cells and adipocytes were cultured under three conditions: negative control, lipopolysaccharide, and concanavalin A (Con A). A linear mixed model was used to determine differences in resistin concentrations among treatments. RESULTS: Resistin concentrations in OA SF were comparable to healthy SF. Neither serum nor SF resistin was correlated with BCS. Cultured PBMC stimulated with Con A released resistin, while adipocytes did not. CONCLUSION: Neither serum nor SF resistin were altered in dogs with OA secondary to CrCL insufficiency. In addition, resistin was not correlated with canine body fat and did not appear to function as adipocytokine in the dog. CLINICAL SIGNIFICANCE: Resistin may not be involved in the pathogenesis of OA. However, resistin may be important in inflammation because it is released from inflammatory cells.

Immunomodulatory in vitro effects of oclacitinib on canine T-cell proliferation and cytokine production.

BACKGROUND: Oclacitinib is a Janus kinase inhibitor used to control pruritus and skin lesions in canine allergic skin disease; its effect on canine T cells is not well-characterized. HYPOTHESIS/OBJECTIVES: To evaluate the impact of oclacitinib on cultured T cells using peripheral blood mononuclear cells from dogs. ANIMALS: Six bluetick coonhounds. METHODS AND MATERIALS: Lymphocyte-enriched cells were incubated with or without the T-cell mitogen concanavalin A (Con A), oclacitinib (0.5, 1 or 10 µM), ciclosporin (200 ng/mL), Con A + oclacitinib 1 µM and Con A + ciclosporin. We assessed both T-cell proliferation and the secretion of cytokines. RESULTS: Ciclosporin and oclacitinib both inhibited the spontaneous proliferation of T cells; this effect was significant only after incubation with oclacitinib at 10 µM. At this concentration, oclacitinib significantly reduced the spontaneous secretion of clonal activator cytokines [interleukin (IL)-2, IL-15], pro-inflammatory cytokines (interferon-gamma (IFN-γ), IL-18) and the regulatory cytokine IL-10; tumour necrosis factor alpha (TNF-α) and IL-6 cytokine production was mildly inhibited. After Con A stimulation, only T cells co-treated with ciclosporin achieved a significant proliferation inhibition and reduction of IL-2, IL-10, IL-15, IL-18, IFN-γ and TNF-α. Surprisingly, oclacitinib at 1 µM (337 ng/mL, corresponding to the oral dosage of 0.4-0.6 mg/kg) did not significantly affect Con A-stimulated T-cell proliferation nor cytokine production (IL-2, IL-10, IL-15, IL-18, IFN-γ and TNF-α). CONCLUSIONS: Although a limited number of dogs were investigated, these preliminary results suggest that oclacitinib appears to have immunosuppressive properties, but only at dosages above those used to treat allergic pruritus in dogs.

Correlation of serum and synovial leptin concentrations with body condition scores in healthy and osteoarthritic dogs.

OBJECTIVE: To evaluate the relationship between serum and synovial fluid (SF) leptin concentrations and body condition score (BCS) in healthy and osteoarthritic dogs. STUDY DESIGN: Controlled, prospective, clinical study. ANIMALS: Nineteen healthy dogs and 29 dogs with osteoarthritis (OA) secondary to cranial cruciate ligament injury. METHODS: Synovial fluid was obtained from the femorotibial joint under sedation (healthy dogs) or during surgery (OA dogs). Serum and SF leptin and interleukin (IL)-1ß concentrations were measured via enzyme-linked immunosorbent assay. Dogs were classified as optimal weight (BCS 4-5/9) or overweight (BCS >5/9). Radiographs were scored for OA severity by a radiologist. Owners completed the Liverpool Osteoarthritis in Dogs (LOAD) questionnaire. RESULTS: Mean (± SD) SF leptin (4.09 ± 4 ng/mL) was lower than serum leptin (6.88 ± 5.52 ng/mL, P < .0001). Synovial fluid leptin was higher in overweight (5.28 ± 4.21) than in optimal body weight dogs (1.54 ± 1.72 ng/mL, P < .0001). Serum (P < .001) and SF leptin (P = .004) concentrations were associated with BCS. Concentration of SF leptin did not differ between healthy (2.4 ± 2.04 ng/mL) and OA (4.9 ± 4.3 ng/mL, P = .25) dogs. Synovial fluid leptin and LOAD scores were weakly associated (P = .03). No association was detected between SF leptin and radiographic score or IL-1ß (P = .73). CONCLUSION: Serum and SF leptin correlated with BCS in this population. Synovial fluid leptin was weakly associated with LOAD scores but not with radiographic severity of OA or IL-1ß. CLINICAL SIGNIFICANCE: Serum and SF leptin concentrations do not predict radiographic severity of canine OA but contribute to joint pain and dysfunction.

Environmental Lead and Wild Birds: A Review.

Lead is a persistent inorganic environmental pollutant that affects humans and animals worldwide. Avian species are especially susceptible to lead exposure through consumption of lead ammunition, lead fishing tackle, and other contaminated food sources such as aquatic species ingesting lead contaminated sediments in mining areas. Even with government regulations on the use of lead ammunition in many countries, including the United States, terrestrial, aquatic, predatory, and scavenger avian species are still at risk of exposure to potentially lethal concentrations of lead. The toxicities seen in these avian species include increased oxidative stress and decreased anti-oxidant enzymes in hepatic and renal tissue. The avian immune system is also a target of lead and displays a number of altered functions suggestive of immune suppression; however, studies in wildlife and laboratory species remain too limited for definitive statements with regard to population risk. In contrast, lead clearly inhibits reproductive capabilities in adult birds, and alters growth and development of hatchlings. Environmental remediation for lead removal, which would lower toxic exposure in wildlife, presently is a monumental and prohibitively expensive effort. Wildlife exposure will therefore continue in contaminated areas, necessitating development of new remediation practices. These plans should aim toward limiting more widespread or heavier contamination of wildlife habitats. This chapter reviews presently available information of lead toxicity in wild bird species, and suggests continued monitoring and reduction strategies to reduce lead exposure for at-risk avian populations.

Seeding of the mucosal leukocytes in the HALT and trachea of White Leghorn chickens.

Characterising the immune cells of the head-associated lymphoid tissues (HALT) and trachea during maturation in young birds is critical to understanding the immunological responses to avian respiratory diseases and vaccines. Selected mucosal leukocytes of the conjunctiva-associated lymphoid tissue (CALT), Harderian gland (HG), nasal-associated lymphoid tissue (NALT) and trachea from 4-, 6-, 8-, and 10-week-old chickens were enumerated and phenotyped. HG, NALT, and trachea cellularity increased as the birds aged with cell viability varying by tissue. The results showed that the T cell subset numbers, but not B cell numbers, increased in the mucosal tissues of chickens during aging.

Ingestion of a Single 2.3 mm Lead Pellet by Laying Roller Pigeon Hens Reduces Egg Size and Adversely Affects F1 Generation Hatchlings.

Many aquatic and terrestrial avian species inadvertently ingest lead (Pb) in the form of spent or fragmented ammunition, mistaking it for food or grit. Previous studies in our laboratory have shown that ingestion of even a single 45-mg pellet can significantly increase blood-Pb levels and significantly inhibit the enzyme delta aminolevulinic-acid dehydratase (δ-ALAD) for a period of greater than 4 weeks. In the current study, proven breeder pairs of domestic Roller pigeons were housed in individual cages. The hens were orally gavaged with dH2O vehicle, a single #9 Pb pellet (2.0 mm/45 mg) or a single #7.5 Pb pellet (2.3 mm/95 mg), placed back with the cock bird and allowed to mate for two consecutive clutches. The eggs were monitored for fertilization, shell damage, egg weight, and length during the 16- to 18-day incubation period. Hatchlings remained with the hen and cock through the weaning period (28-35 days post hatch) and were monitored for weight, development, and mortality. Weanling blood was collected for blood-Pb levels, δ-ALAD activity, red blood cell counts, total protein, and packed cell volume. Following euthanasia, weanling liver, spleen, kidney, sciatic nerve, thymus, and brain were collected for histopathology. Egg weight and length were significantly decreased in the #7.5 Pb pellet treatment group for the first clutch, and hatchling weight 7 days post hatch also was significantly less in the #7.5 Pb pellet treatment group during the first clutch. Histopathologic analysis showed increased lesions in liver, kidney, spleen, and thymus of the Pb-treated weanlings, during both the first and second clutch compared with the non-Pb-treated weanlings. These data suggest that maternal consumption of a single 95-mg Pb pellet can adversely impact egg size and hatchling organ development.

Influence of collection time on hematologic and immune markers in the American alligator (Alligator mississippiensis).

Crocodilians are important keystone species and indicators of environmental health. Much remains unknown, however regarding utility of field-collected crocodilian blood samples for ecologic assessments. Field sampling sites are also often distant to analysis centers, necessitating development of new techniques and panels of assays that will yield environmentally relevant data. Stability and viability of hematological and immunological indices have been of particular interest for linking ecosystem health to biomarkers in resident species. In this study, we investigated the effect of time at analysis post-blood sampling at 4 and 24 hr on a panel of potential biomarkers in alligator blood. Our results suggest alligator blood samples can be reliably evaluated for both hematologic and immunologic profile 24 hr after sampling.

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.

Effects of Artemisia annua supplementation on the performance and gut health of laying hens challenged with mixed Eimeria species.

Background: Coccidiosis outbreaks in susceptible laying hens can significantly decrease egg production and cause substantial economic loss to the egg industry. The supplementation of poultry diets with chemotherapeutic agents is limited due to antimicrobial resistance and residue in poultry meat or processed products. Therefore, alternative strategies to control coccidiosis are needed, and Artemisia annua (AA) might have the potential to be a phytogenic feed additive, an alternative to anticoccidial agents. This study aimed to investigate the effect of the dietary supplementation of powdered AA on the performance and gut health of laying hens infected with coccidiosis by Eimeria spp. Methods: A total of 225 Hy-Line W-36 laying hens at 23 weeks of age were allocated into 5 treatment groups: 1) control (NC), 2) pair-fed (PF) control, 3) challenged control (CC), 4) CC with dietary inclusion of 0.5% AA (0.5AA), and v) CC with dietary inclusion of 1% AA (1AA). The hens in the CC, 0.5AA, and 1AA groups were orally inoculated with sporulated oocysts of Eimeria maxima (12,500), Eimeria tenella (12,500), and Eimeria acervulina (62,500) at week 25. The PF hens received the same amount of feed consumed by the CC hens from 0-14 days post-inoculation (dpi) of Eimeria spp. The performance of the laying hens, including body weight (BW), hen-day egg production (HDEP), feed intake (FI), and feed conversion ratio (FCR), was measured weekly. Additionally, markers of intestinal health, including gut permeability, lesion score, intestinal morphometry, and immune responses, were evaluated at 6, 14, and 21 dpi. Results: At 6 and 14 dpi, laying hens challenged with Eimeria spp. had a lower BW than PF and NC hens (p < 0.0001). Supplementation of 1% AA improved the HDEP by 8.1% compared to CC hens; however, it was still 15.4% lower than that of PF hens (p < 0.0001). The inclusion of 1% AA did not have any beneficial effect on FI; however, the FCR was improved by 0.61 (2.46) than that of CC hens (3.07; p < 0.0001). The inclusion of 1% AA reduced the severity of the intestinal lesions and increased the recovery of intestinal villi (p < 0.05). Additionally, gut permeability was significantly different between the challenged and non-challenged hens; however, among the challenged hens, the inclusion of AA reduced the gut permeability by 29% compared to CC hens (p < 0.0001). Furthermore, the inclusion of 0.5% AA reduced the inflammatory responses in the infected hens. Conclusion: Dietary inclusion of AA partially restored the performance and gut health of the laying hens and modulated their inflammatory immune response following Eimeria infection; however, further studies are needed to better understand the mode of action and effective dosages to improve the gut health without negative impacts on the performance.

Effect of dietary inclusion of 25-hydroxyvitamin D3 and vitamin E on performance, gut health, oxidative status, and immune response in laying hens infected with coccidiosis.

Vitamin D3 (25-hydroxyvitamin D3 (VD)) and vitamin E (VE) have proven to have immunomodulatory and antioxidant functions along with capacities to improve the reproductive function in chickens. Coccidiosis in laying hens at different stages of growth has been shown to negatively affect performance, immune response, and oxidative status, thus increasing the cost of production. A study was conducted to evaluate the influence of dietary VD or VE on performance, gut health, immune response, and oxidative status of laying hens at peak production. Laying hens (23 wk-of-age, n = 225) were randomly allocated into 5 treatment groups (n = 9 hens/replicate) with 5 replicate groups each: 1) unchallenged control (UC), 2) pair-fed control (PF), 3) challenged control (CC), 4) challenged control top-dressed with 5,000 IU of 25-hydroxyvitamin D3 (VD) per kg of diet, and 5) challenged control top-dressed with 100 IU of DL-α-tocopherol (VE). At 25 wk-of-age, hens grouped in CC, VD, and VE were challenged with mixed Eimeria spp. to induce coccidiosis. VD or VE supplemented hens did not impact bird body weight; however, egg production increased by 10.36% and 13.77%, respectively (P < 0.0001). Furthermore, the gut health of the hens was improved with either VD or VE supplementation, as indicated by lowered gut permeability and intestinal lesion scores (P < 0.05). VE significantly reduced the heterophil count (P = 0.0490) alongside numerically increasing the peripheral CD4+ and CD8+ T cells and monocyte counts (P > 0.05). Both VD or VE increased the TAC at 14 DPI compared to UC (P<0.05). Preliminary findings suggest that dietary VD or VE supplementation has the potential to improve gut health, modulate the immune response, and increase egg production in coccidiosis-infected laying hens.

Impact of apitherapy on canine, equine, and chicken lymphocytes, in vitro.

Apitherapy is a form of alternative medicine that utilizes products from the western honeybee (Apis mellifera), including honey, propolis, and honeybee venom, to improve the health status of human patients by altering host immunity. An added benefit of these products is that they are nutraceuticals and relatively inexpensive to aquire. Currently, little is known about the use of honeybee products in veterinary species, as well as their impact on host immunity. In the present in vitro study, honey, propolis, and honeybee venom were co-cultured with enriched canine, equine, and chicken peripheral blood lymphocytes (PBLs) with cell proliferation, cell viability/apoptosis, and cellular morphology evaluated. Concanavalin A (Con A) and dexamethasone were used as stimulatory and suppressive controls, respectively. Honeybee products' effects on the three veterinary species varied by product and the species. Honey stimulated the PBLs proliferation in all three species but also displayed some increased cytotoxicity. Propolis stimulated proliferation in canine and equine PBLs, however, it suppressed proliferation in the chicken PBLs. Honeybee venom was the strongest PBL stimulant for all three species and in the equine, surpassed the stimulant response of Con A and yet, enhanced PBL cell viability post culture. In summary, the results of this preliminary in vitro study show that these three honeybee products do impact lymphocyte proliferation and viability in dogs, horses, and chickens, and that more research both in vitro and in vivo will be necessary to draw conclusions regarding their future use as immune stimulants or inhibitors.

Parabens: potential impact of low-affinity estrogen receptor binding chemicals on human health.

Parabens, alkyl esters of p-hydroxybenzoic acid, are widely used in cosmetics, pharmaceuticals, personal care products and as food additives to inhibit microbial growth and extend product shelf life. Consumers of these compounds are frequently exposed via the skin, lips, eyes, oral mucosa, nails, and hair. Parabens are estrogenic molecules but exert weaker activity than natural estrogens, which would imply a low risk. Consistent with this idea, a number of recent commission reports from different countries suggested that parabens pose a negligible endocrine-disrupting risk at the recommended doses. However, individuals are not routinely exposed to a single paraben, and most of the available paraben toxicity data, reviewed in these reports, are from single-exposure studies. Further, assessing the additive and cumulative risk of multiple paraben exposure from daily use of multiple cosmetic and/or personal care products is presently not possible based on current studies. In this review, current and recent studies of paraben exposure and public health policies as well as critical gaps in the knowledge are discussed and new research directions regarding multiple exposures and novel target cohorts are recommended.

Influence of different cell storage/culture conditions on spontaneous proliferation and level of tyrosine kinase receptor inhibition in two feline injection-site sarcoma cell lines.

Optimizing cell culture conditions is important when studying cell proliferation and viability, particularly in response to cytotoxic compounds. Altered cell storage conditions can adversely impact proliferation and viability in mortal cell lines. However, little is known regarding the effects on immortal feline cell lines. In the present study, two feline injection-site sarcoma (ISS) cell lines were evaluated under standard culture conditions and three alternative storage/culture conditions for spontaneous proliferation rate and sensitivity to masitinib, a highly selective tyrosine kinase inhibitor with activity against primary and metastatic ISS cell lines. Cell viability was assessed by 7-aminoactinomycin D and cytology. Spontaneous proliferation did not significantly differ across the FBS concentrations (10% vs. 1%) for one cell line, however, with the other cell line spontaneous proliferation was significantly decreased in the 1% FBS 1-step technique, and the cold step technique at both 1% and 10% FBS. When normalized to untreated control cells, the IC50 values for masitinib were comparable across all culture techniques. Furthermore, apoptosis appeared to be the primary mechanism of this proliferation inhibition. Our preliminary findings suggest that select feline sarcoma cell lines cultured in 10% FBS yield comparable cytotoxicity data even when subjected to varying storage/culture conditions.

Endocrine-disrupting chemical exposure and the American alligator: a review of the potential role of environmental estrogens on the immune system of a top trophic carnivore.

Endocrine-disrupting chemicals (EDCs) alter cellular and organ system homeostasis by interfering with the body's normal physiologic processes. Numerous studies have identified environmental estrogens as modulators of EDC-related processes in crocodilians, notably in sex determination. Other broader studies have shown that environmental estrogens dysregulate normal immune function in mammals, birds, turtles, lizards, fish, and invertebrates; however, the effects of such estrogenic exposures on alligator immune function have not been elucidated. Alligators occupy a top trophic status, which may give them untapped utility as indicators of environmental quality. Environmental estrogens are also prevalent in the waters they occupy. Understanding the effects of these EDCs on alligator immunity is critical for managing and assessing changes in their health and is thus the focus of this review.