Short Interspersed Element (SINE) Depletion and Long Interspersed Element (LINE) Abundance Are Not Features Universally Required for Imprinting

Genomic imprinting is a form of gene dosage regulation in which a gene is expressed from only one of the alleles, in a manner dependent on the parent of origin. The mechanisms governing imprinted gene expression have been investigated in detail and have greatly contributed to our understanding of genome regulation in general. Both DNA sequence features, such as CpG islands, and epigenetic features, such as DNA methylation and non-coding RNAs, play important roles in achieving imprinted expression. However, the relative importance of these factors varies depending on the locus in question. Defining the minimal features that are absolutely required for imprinting would help us to understand how imprinting has evolved mechanistically. Imprinted retrogenes are a subset of imprinted loci that are relatively simple in their genomic organisation, being distinct from large imprinting clusters, and have the potential to be used as tools to address this question. Here, we compare the repeat element content of imprinted retrogene loci with non-imprinted controls that have a similar locus organisation. We observe no significant differences that are conserved between mouse and human, suggesting that the paucity of SINEs and relative abundance of LINEs at imprinted loci reported by others is not a sequence feature universally required for imprinting

Lawsonia intracellularis exploits β-catenin/Wnt and Notch signalling pathways during infection of intestinal crypt to alter cell homeostasis and promote cell proliferation

Lawsonia intracellularis is an obligate intracellular bacterial pathogen that causes proliferative enteropathy (PE) in pigs. L. intracellularis infection causes extensive intestinal crypt cell proliferation and inhibits secretory and absorptive cell differentiation. However, the affected host upstream cellular pathways leading to PE are still unknown. β-catenin/Wnt signalling is essential in maintaining intestinal stem cell (ISC) proliferation and self-renewal capacity, while Notch signalling governs differentiation of secretory and absorptive lineage specification. Therefore, in this report we used immunofluorescence (IF) and quantitative reverse transcriptase PCR (RTqPCR) to examine β-catenin/Wnt and Notch-1 signalling levels in uninfected and L. intracellularis infected pig ileums at 3, 7, 14, 21 and 28 days post challenge (dpc). We found that while the significant increase in Ki67+ nuclei in crypts at the peak of L. intracellularis infection suggested enhanced cell proliferation, the expression of c-MYC and ASCL2, promoters of cell growth and ISC proliferation respectively, was down-regulated. Peak infection also coincided with enhanced cytosolic and membrane-associated β-catenin staining and induction of AXIN2 and SOX9 transcripts, both encoding negative regulators of β-catenin/Wnt signalling and suggesting a potential alteration to β-catenin/Wnt signalling levels, with differential regulation of the expression of its target genes. We found that induction of HES1 and OLFM4 and the down-regulation of ATOH1 transcript levels was consistent with the increased Notch-1 signalling in crypts at the peak of infection. Interestingly, the significant down-regulation of ATOH1 transcript levels coincided with the depletion of MUC2 expression at 14 dpc, consistent with the role of ATOH1 in promoting goblet cell maturation. The lack of significant change to LGR5 transcript levels at the peak of infection suggested that the crypt hyperplasia was not due to the expansion of ISC population. Overall, simultaneous induction of Notch-1 signalling and the attenuation of β-catenin/Wnt pathway appear to be associated with the inhibition of goblet cell maturation and enhanced crypt cell proliferation at the peak of L. intracellularis infection. Moreover, the apparent differential regulation of apoptosis between crypt and lumen cells together with the strong induction of Notch-1 signalling and the enhanced SOX9 expression along crypts 14 dpc suggest an expansion of actively dividing transit amplifying and/or absorptive progenitor cells and provide a potential basis for understanding the development and maintenance of PE

Opportunities and Challenges in Providing Health Care for International Retirement Migrants: A Qualitative Case Study of Canadians Travelling To Yuma, Arizona

Background Increasing numbers of older individuals opt to spend extended time abroad each year for lifestyle, health, and financial reasons. This practice is known as international retirement migration, and it is particularly popular among retirees in Global North countries such as Canada. Despite the popularity of international retirement migration, very little is known about how and why health care is accessed while abroad, nor the opportunities and challenges posed for destination hospitals. In this article we focus on addressing the latter knowledge gap. Methods This qualitative case study is focused on the only hospital in Yuma, Arizona – a popular destination for Canadian retirement migrants in the United States. We conducted focus groups with workers at this hospital to explore their experiences of treating this transnational patient group. Twenty-seven people participated in three, 90-min focus groups: twelve nurses, six physicians, and nine administrators. Thematic analysis of the focus group transcripts was conducted using a triangulated approach. Results Participants identified three care environments: practice, transnational, and community. Each environment presents specific opportunities and challenges pertaining to treating Canadian retirement migrants. Important opportunities include the creation of a strong and diverse seasonal workforce in the hospital, new transnational paths of communication and information sharing for physicians and health administrators, and informal care networks that support formal health care services within and beyond the hospital. These opportunities are balanced out by billing, practical, administrative, and lifestyle-related challenges which add complexity to treating this group of transnational patients. Conclusion Canadians represent a significant group of patients treated in Yuma, Arizona. This is contrary to long-standing, existing research that depicts older Canadians as being reluctant to access care while in the United States. Significant overlaps exist between the opportunities and challenges in the practice, transnational and community environments. More research is needed to better understand if these findings are similar to other destinations popular with Canadian international retirement migrants or if they are unique to Yuma, Arizona

Co-infection of cattle with Fasciola hepatica or F. gigantica and Mycobacterium bovis: A systematic review

The liver flukes, Fasciola hepatica and F. gigantica, are common trematode parasites of livestock. F. hepatica is known to modulate the immune response, including altering the response to co-infecting pathogens. Bovine tuberculosis (bTB), caused by Mycobacterium bovis, is a chronic disease which is difficult to control and is of both animal welfare and public health concern. Previous research has suggested that infection with liver fluke may affect the accuracy of the bTB skin test, but direction of the effect differs between studies. In a systematic review of the literature, all experimental and observational studies concerning co-infection with these two pathogens were sought. Data were extracted on the association between fluke infection and four measures of bTB diagnosis or pathology, namely, the bTB skin test, interferon γ test, lesion detection and culture/bacterial recovery. Of a large body of literature dating from 1950 to 2019, only thirteen studies met the inclusion criteria. These included studies of experimentally infected calves, case control studies on adult cows, cross sectional abattoir studies and a herd level study. All the studies had a medium or high risk of bias. The balance of evidence from the 13 studies included in the review suggests that liver fluke exposure was associated with either no effect or a decreased response to all of the four aspects of bTB diagnosis assessed: skin test, IFN γ, lesion detection and mycobacteria cultured or recovered. Most studies showed a small and/or non-significant effect so the clinical and practical importance of the observed effect is likely to be modest, although it could be more significant in particular groups of animals, such as dairy cattle

The effectiveness of celebrities in conservation marketing

Celebrities are frequently used in conservation marketing as a tool to raise awareness, generate funding and effect behaviour change. The importance of evaluating effectiveness is widely recognised in both marketing and conservation but, to date, little research into the effectiveness of celebrity endorsement as a tool for conservation marketing has been published. Using a combination of interviews and an online choice survey instrument, we investigated the extent to which a sample of UK-based conservation organisations, and other charities, evaluate their own usage of celebrity endorsement, and then carried out an experimental evaluation of a hypothetical marketing campaign. This experiment compared participants' willingness-to-engage (WTE) with, and recall of, a conservation message presented in versions of an advert featuring one of three prominent UK celebrities (David Beckham, Chris Packham or HRH Prince William) or a non-celebrity control treatment (featuring Crawford Allan, a director of TRAFFIC USA). We find that the organisations we interviewed did not routinely evaluate their marketing campaigns featuring celebrities. Furthermore, our experiment provides evidence that celebrity endorsement can produce both positive and negative effects. Participants were more willing to engage when presented with an advert featuring one of the three celebrities than the non-celebrity control, and WTE varied according to the characteristics of the celebrity and the respondent. However, celebrities were less effective at generating campaign message recall than non-celebrities. These findings suggest that celebrity endorsement should be used carefully. Further work is required to fully understand the role celebrity endorsers can play in conservation but, drawing on best practice from the field of marketing, this study introduces an approach to evaluation which could be applied more widely to improve the effectiveness of conservation marketing

Mitochondrial damage-associated molecular patterns (DAMPs) in inflammatory bowel disease

Background The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD) are chronic relapsing inflammatory disorders which have a rising incidence and cause significant morbidity. There are currently several treatment options with many more in the drug pipeline, but there are a lack of accurate biomarkers for decisions on treatment choice, assessment of disease activity and prognostication. There is a growing interest and desire for personalised or ‘precision’ medicine in IBD where novel biomarkers may help individualise IBD care in terms of diagnosis, choice of therapy, monitoring of response and detection of relapse. One class of functionally active biomarkers which have yet to be thoroughly investigated in IBD is damage-associated molecular patterns (DAMPs) including mitochondrial DNA (mtDNA). It has been recently shown that gut mitochondrial dysfunction can result in loss of epithelial barrier function and the development of colitis. Mitochondrial DAMPs have recently been described as elevated in several inflammatory diseases. Hypothesis The primary hypothesis of this thesis is that circulating levels of mtDNA is elevated in IBD. Secondary hypotheses are: (a) levels of other mitochondrial DAMPs are elevated in IBD, (b) circulating mtDNA can be used as a novel biomarker in IBD and (c) mtDNA is released locally at sites of inflammation in IBD. Methods Plasma and serum were collected prospectively from recruited IBD patients and non-IBD controls. Faeces and colonic tissue were collected from a subset of these patients. mtDNA in serum, plasma and faeces was measured using qPCR (amplifying COXIII/ND2 genes). Mass spectrometry was used to detect mitochondrial formylated peptides in the plasma of a subset of patients. IBD tissue was assessed for (a) mitochondrial damage using transmission electron microscopy (TEM) and (b) TLR9 expression, the target for mtDNA. Results 97 patients with IBD (67 UC and 30 CD), and 40 non-IBD controls were recruited. Plasma mtDNA levels were increased in UC and CD (both p<0.0001) compared to non-IBD controls; with significant correlations with blood (CRP, albumin, white cell count), clinical and endoscopic markers of severity; and disease activity. In active UC, we detected significantly higher circulating mitochondrial formylated peptides and faecal mtDNA levels (vs. non-IBD controls [p<0.01 and <0.0001 respectively]) with demonstrable TEM evidence of intestinal mucosal mitochondrial damage. In active IBD, TLR9+ lamina propria inflammatory cells were significantly higher in UC/CD compared to controls (both p<0.05). Conclusions Taken together, the findings suggest mtDNA is released during active inflammation in inflammatory bowel disease and is a potential novel mechanistic biomarker

Use of Excretory/Secretory Antigens in a Competition Test to Follow the Kinetics of Infection by Fasciola Hepatica in Cattle

Eight 16-18-month-old Charolais heifers were experimentally infected with Fasciola hepatica. An antigen competition assay was used to follow the kinetics of the infection and was compared to antibody tires and serum liver enzymes. The antigen competition assay was able to detect the presence of infection as soon as 6 days after the start of the experimental infection which is considerably sooner than other methods. Consequently, this assay would be useful in diagnosing fasciolosis early in the prepatent period. The animals were slaughtered at the end of the experiment, the livers recovered and post-mortem fluke burdens determined. However, only serum liver enzyme levels gave any indication of the intensity of infection in the different animals

Effect of Front-Panel Support during Inclined Treadmill Walking

Hoover, K., Peterson, M., Timmons, K., Mason, S., Venters, E., Crehan, L., McKenzie, J.A., and McCole, S.D. Department of Exercise Science & Physical Education, McDaniel College, Westminster, MD Purpose: The study’s purpose was to determine the effect of front-panel support during inclined treadmill walking. Methods: Healthy, physically active females (n=10) and males (n=10) each performed a VO2max test on a treadmill and two 30-min bouts of inclined treadmill walking, one with the arms holding onto the front panel of the treadmill (FPS) and one using a normal arm swing (NAS) at least 48 hours apart. Walking tests consisted of 10 min on a level grade followed by a 4% increase in grade every 5 min. A walking speed that elicited 50% of a participant’s VO2max was used throughout each test. VO2, cardiac output (CO), RER, BP, and RPE were measured throughout each test. Arteriovenous O2 difference (a-v O2 diff) was calculated from VO2 and CO data using standard calculations. Each test was preceded by 10 minutes of rest for measurement of baseline values. VO2, RER, and energy expenditure (kcal) were measured using a calibrated ParvoMedics TrueOne metabolic system every 15 s throughout the test. CO was determined every 10 s via impedance cardiography (Physioflow Enduro). Values were analyzed for significant differences (p\u3c 0.05) between trials using paired t-tests. Results: All data reported as mean ± SEM. Participants averaged 24 ± 1 yr, 76.5 ± 4.3 kg and 1.73 ± 0.02 m with a VO2max of 49.4 ± 2.1 mL/kg/min. Baseline values were not significantly different (p \u3e 0.05) between the walking tests. VO2 was significantly lower in FPS (21.9 ± 0.9, 25.5 ± 1.0, and 30.9 ± 1.3 mL/kg/min) compared to NAS (26.1 ± 0.8, 33.6 ± 1.0, and 41.9 ± 1.6 mL/kg/min) for 4%, 8%, and 12% grade, respectively. Q was significantly lower in FPS (13.1 ± 0.7, 14.6 ± 0.8, and 17.0 ± 1.2 L/min) compared to NAS (16.2 ± 1.1, 19.7 ± 1.3, and 23.7 ± 1.4 L/min) for 4%, 8%, and 12% grade, respectively. a-v O2 diff was not significantly different between trials at any intensity. RER was significantly lower in FPS only during the last two stages of the test (0.84 ± 0.01 and 0.82 ± 0.02) compared to NAS (0.86 ± 0.02 and 0.88 ± 0.02). Energy expenditure (kcal) was significantly lower in FPS (40 ± 2, 46 ± 3, and 55 ± 4) compared to NAS (48 ± 3, 60 ± 4, and 74 ± 5 for 4%, 8%, and 12% grade, respectively). Conclusion: The use of FPS significantly reduced the metabolic and cardiovascular cost of inclined treadmill walking. Research supported by the McDaniel College Student-Faculty Collaborative Summer Research Fun