Ecology of the Squirrel Treefrog (Hyla squirella) in Southern Arkansas

We conducted an ecological study of the Squirrel Treefrog, Hyla squirella near El Dorado, Union Co., Arkansas from May-Oct. 2013. We extended the known distribution by ~2 km and documented the first breeding occurring on 28 May and the first transformation of juveniles on 27 Aug. Three endoparasites were documented: Opalina sp., Nyctotherus cordiformis, and Physaloptera sp. larvae. We also provide information on endoparasites of Florida H. squirella as well as a summary of helminths of this frog

Testicular Histology and Sperm Morphometrics of the Bird-voiced Treefrog, Hyla avivoca (Anura: Hylidae), from Arkansas

We examined the testicular histology and spermatozoal dimensions of the bird-voiced treefrog, Hyla avivoca (Anura: Hylidae), from samples collected in May, June, and July from localities in three counties (Calhoun, Conway, and Little River) in Arkansas. Calling frogs were necropsied in the lab, and testes were prepared for light and scanning electron microscopy. Spermatocysts within seminiferous tubules of all males contained large aggregates of spermatozoa. Primary spermatogonia, the largest of all germ cells, ranged from 13.3 – 17.8 μm in diameter (= 15.37 ± 1.22; n = 20). Measurements of sperm dimensions yielded the following length parameters (range, mean ± standard deviation, sample size): acrosome, 2.10 – 3.37 μm (= 2.58 ± 0.40; n = 11); nucleus, 10.22 – 13.71 μm (= 11.70 ± 0.86; n = 65); acrosome, nucleus, midpiece complex (ANM) in three frogs, 14.87 – 23.98 μm (= 19.62 ± 2.72; n = 17), 18.83 – 26.96 μm (= 22.92 ± 2.26; n = 17), 17.40 –26.96 μm (= 23.92 ± 3.27; n = 11); principal piece, 24.36 – 27.68 μm (= 25.98 ± 1.19; n = 14); total tail length (endpiece intact), 29.87 – 39.00 μm (= 33.37 ± 2.63; n = 23); and total sperm length, 51.02 – 62.98 μm (= 54.63 ± 3.54; n = 20). Our sperm morphometric findings complement previously published data on this species and fill in gaps that may aid in future intra- and interfamilial comparisons

Hematozoan Parasites (Apicomplexa, Kinetoplastida) of Seven Arkansas Reptiles (Testudines, Ophidia)

Little is known concerning the hematozoan parasites of Arkansas reptiles. Although there are previous reports in the state of these intraerythrocytic parasites infecting various reptiles, additional research is sorely needed. Here, we attempt to augment that void by providing additional hosts infected by these apicomplexans, including the first report of a trypomastigote of a Trypanosoma sp. from an Arkansas turtle

Signaling via interleukin-4, receptor alpha chain is required for successful vaccination against schistosomiasis in BALB/c mice

Radiation-attenuated (RA) schistosome larvae are potent stimulators of innate immune responses at the skin site of exposure (pinna) that are likely to be important factors in the development of Th1-mediated protective immunity. In addition to causing an influx of neutrophils, macrophages, and dendritic cells (DCs) into the dermis, RA larvae induced a cascade of chemokine and cytokine secretion following in vitro culture of pinna biopsy samples. While macrophage inflammatory protein 1 and interleukin-1 (IL-1) were produced transiently within the first few days, the Th1-promoting cytokines IL-12 and IL-18 were secreted at high levels until at least day 14. Assay of C3H/HeJ mice confirmed that IL-12 secretion was not due to lipopolysaccharide contaminants binding Toll-like receptor 4. Significantly, IL-12 p40 secretion was sustained in pinnae from vaccinated mice but not in those from nonprotected infected mice. In contrast, IL-10 was produced from both vaccinated and infected mice. This cytokine regulates IL-12-associated dermal inflammation, since in vaccinated IL-10/ mice, pinna thickness was greatly increased concurrent with elevated levels of IL-12 p40. A significant number of IL-12 p40 cells were detected as emigrants from in vitro-cultured pinnae, and most were within a population of rare large granular cells that were Ia, consistent with their being antigen-presenting cells. Labeling of IL-12 cells for CD11c, CD205, CD8, CD11b, and F4/80 indicated that the majority were myeloid DCs, although a proportion were CD11c F4/80, suggesting that macrophages were an additional source of IL-12 in the skin

Solution-focused intervention for sick listed employees with psychological problems or muscle skeletal pain: a randomised controlled trial [ISRCTN39140363]

BACKGROUND: Long-term sick leave has been of concern to politicians and decision-makers in Norway for several years. In the current study we assess the efficacy of a solution-focused follow-up for sick-listed employees. METHODS: Employees on long-term sick leave due to psychological problems or muscle skeletal pain (n = 703) were invited to participate in the project. Following self-recruitment, 103 were randomly allocated to receive solution-focused follow-up (n = 53) or "treatment as usual" (n = 50). The intervention was integrated within the regular follow up of six social security offices and organised as eight weekly solution focused work sessions. Effectiveness was measured by rate of return to work and health related quality of life (SF-36). RESULTS: Intention to treat analysis showed no significant differences between the two groups for any of the outcome measures. Secondary analysis, comparing those who attended at least 50% of the sessions with the control group revealed a significant difference in favour of the active intervention group in the SF-36 subscale of mental health (Effect Size 0.56, p = 0.05). When comparing the subgroup of participants with psychological problems there was a significant difference in mental health in favour of the intervention group (Effect Size 0.71, p = 0.041). CONCLUSION: A voluntary solution-focused intervention offered by social-security offices is no more effective than regular follow up for employees on long-term sick leave due to psychological problems or muscle skeletal pain

A series of Fas receptor agonist antibodies that demonstrate an inverse correlation between affinity and potency

Receptor agonism remains poorly understood at the molecular and mechanistic level. In this study, we identified a fully human anti-Fas antibody that could efficiently trigger apoptosis and therefore function as a potent agonist. Protein engineering and crystallography were used to mechanistically understand the agonistic activity of the antibody. The crystal structure of the complex was determined at 1.9 Å resolution and provided insights into epitope recognition and comparisons with the natural ligand FasL (Fas ligand). When we affinity-matured the agonist antibody, we observed that, surprisingly, the higher-affinity antibodies demonstrated a significant reduction, rather than an increase, in agonist activity at the Fas receptor. We propose and experimentally demonstrate a model to explain this non-intuitive impact of affinity on agonist antibody signalling and explore the implications for the discovery of therapeutic agonists in general

Associations of IL-4, IL-4R, and IL-13 Gene Polymorphisms in Coal Workers' Pneumoconiosis in China: A Case-Control Study

Background: The IL-4, IL-4 receptor (IL4R), and IL-13 genes are crucial immune factors and may influence the course of various diseases. In the present study, we investigated the association between the potential functional polymorphisms in IL-4, IL-4R, and IL-13 and coal workers ’ pneumoconiosis (CWP) risk in a Chinese population. Methods: Six polymorphisms (C-590T in IL-4, Ile50Val, Ser478Pro, and Gln551Arg in IL-4R, C-1055T and Arg130Gln in IL-13) were genotyped and analyzed in a case-control study of 556 CWP and 541 control subjects. Results: Our results revealed that the IL-4 CT/CC genotypes were associated with a significantly decreased risk of CWP (odd

Fas Signalling Promotes Intercellular Communication in T Cells

Cell-to-cell communication is a fundamental process for development and maintenance of multicellular organisms. Diverse mechanisms for the exchange of molecular information between cells have been documented, such as the exchange of membrane fragments (trogocytosis), formation of tunneling nanotubes (TNTs) and release of microvesicles (MVs). In this study we assign to Fas signalling a pivotal role for intercellular communication in CD4+ T cells. Binding of membrane-bound FasL to Fas expressing target cells triggers a well-characterized pro-apoptotic signalling cascade. However, our results, pairing up flow cytometric studies with confocal microscopy data, highlight a new social dimension for Fas/FasL interactions between CD4+ T cells. Indeed, FasL enhances the formation of cell conjugates (8 fold of increase) in an early time-frame of stimulation (30 min), and this phenomenon appears to be a crucial step to prime intercellular communication. Our findings show that this communication mainly proceeds along a cytosolic material exchange (ratio of exchange >10, calculated as ratio of stimulated cells signal divided by that recorded in control cells) via TNTs and MVs release. In particular, inhibition of TNTs genesis by pharmacological agents (Latruculin A and Nocodazole) markedly reduced this exchange (inhibition percentage: >40% and >50% respectively), suggesting a key role for TNTs in CD4+ T cells communication. Although MVs are present in supernatants from PHA-activated T cells, Fas treatment also leads to a significant increase in the amount of released MVs. In fact, the co-culture performed between MVs and untreated cells highlights a higher presence of MVs in the medium (1.4 fold of increase) and a significant MVs uptake (6 fold of increase) by untreated T lymphocytes. We conclude that Fas signalling induces intercellular communication in CD4+ T cells by different mechanisms that seem to start concomitantly with the main pathway (programmed cell death) promoted by FasL