Process evaluation of implementation of the early stages of a whole systems approach to obesity in a small Island.

BACKGROUND: The small Atlantic island of St Helena is a United Kingdom Overseas Territory (UKOT) with a high prevalence of childhood obesity (over a quarter of 4-5 and 10-11 year olds) and, anecdotally, adulthood obesity and its associated health detriments. St Helena have taken a whole systems approach to obesity (WSAO) to address the issue. A WSAO recognises the factors that impact obesity as a complex system and requires a 'health in all policies' approach. UK academic and public health technical support was provided to the local St Helena delivery team. This process evaluation sought to explore the early stages of the WSAO implementation and implications for the transferability of the approach to other small island developing states and UKOT. METHODS: Data was collected via eight semi-structured interviews, paper based and online surveys, and document analysis. Thematic analysis was used to analyse the data. RESULTS: The analysis identified three factors which aided the first phase of WSAO implementation: (1) senior leaders support for the approach; (2) the academic support provided to establish and develop the approach; and (3) effective adaptation of UK Government resources to suit the local context. Key challenges of early implementation included: maintaining and broadening stakeholder engagement; limited local workforce capacity and baseline knowledge related to obesity and systems thinking; and limited capacity for support from the UK-based academic team due to contract terms and COVID-19 restrictions. CONCLUSIONS: Early stages of implementation of a WSAO in a UKOT can be successful when using UK's resources as a guide and adapting them to a small island context. All participants recommended other small islands adopt this approach. Continued senior support, dedicated leadership, and comprehensive community engagement is needed to progress implementation and provide the foundation for long-term impact. Small island developing states considering adopting a WSAO should consider political will, senior level buy-in and support, funding, and local workforce knowledge and capacity to enable the best chances of successful and sustainable implementation.

Evaluation of wrist and hip sedentary behaviour and moderate-to-vigorous physical activity raw acceleration cutpoints in older adults.

Wrist-based accelerometers are now common in assessing physical activity (PA) and sedentary behaviour (SB) in population-based studies, but there is a scarcity of raw acceleration cutpoints in older adults. The study aimed to determine and evaluate wrist-based GENEActiv (GA) and hip-based ActiGraph GT3X+ (AG) raw acceleration cutpoints for SB and moderate-to-vigorous PA (MVPA) in older adults ≥60 years of age. A laboratory-based calibration analyses of 34 healthy older adults involved receiver operator characteristic (ROC) curves to determine raw acceleration cutpoints for SB and MVPA. ROC analysis revealed an area under the curve (AUC) of 0.88 for GA SB and MVPA, and 0.90 for AG SB and 0.94 for AG MVPA. Sensitivity optimised SB and specificity optimised MVPA GA cutpoints of 57 mg and 104 mg, and AG cutpoints of 15 mg and 69 mg were also generated, respectively. Cross-validation analysis revealed moderate agreement for GA and AG SB cutpoints, and fair to substantial agreement for GA and AG MVPA cutpoints, respectively. The resultant cutpoints can classify older adults as engaging in SB or not engaging in MVPA but the sensitivity optimised SB cutpoints should be interpreted with a degree of caution due to their modest cross-validation results.

A Description of a Noninvasive Surgical Training Pathway Using Translational Tools to Teach Intracoelomic Implantation of Acoustic Transmitters in Fish.

Researchers engaged in surgical implantation of acoustic transmitters into fish must receive adequate and appropriate training to ensure the welfare of their subjects and the quality of the data collected. Increasingly, researchers are being encouraged to partner with veterinarians to improve training and to consider the principles of animal welfare in training. Here, we describe a five-stage training pathway, including implementation of new training tools (the Translational Training Tools and field certification), that was developed collaboratively by researchers and veterinarians and addresses the "three Rs" of animal welfare in the context of surgical training. The three Rs include animal replacement, reduction of the number of animals used, and refinement of techniques to decrease or eliminate pain or distress. The Translational Training Tools, described in the context of the training pathway, use tools as replacement models during training to reduce the number of animals used and allow for refinement of surgical skills prior to working on live animals. The purpose of this paper is to document the Translational Training Tools and the training pathway, which will be useful in developing de novo protocols for review by Institutional Animal Care and Use Committees and similar bodies.

A non-equivalent group pilot trial of a school-based physical activity and fitness intervention for 10-11 year old english children: born to move.

BACKGROUND: PE lessons are the formal opportunity in schools for promotion of physical activity and fitness. This study aimed to evaluate the effectiveness of a pilot PE intervention on physical activity, fitness, and psychosocial outcomes. METHODS: Participants were 139 children aged 10-11 years from four schools. For six weeks children in two schools received a twice-weekly pilot 'Born to Move' (BTM) physical activity (PA) and fitness intervention alongside one regular PE lesson. Children in the two comparison (COM) schools received their regular twice weekly PE lessons. Outcomes were lesson time and whole-day light (LPA), moderate (MPA), vigorous (VPA), and MVPA, and sedentary time, muscular fitness, cardiorespiratory fitness (CRF), and lesson-specific perceived exertion, enjoyment, and perceived competence. Outcomes were assessed at baseline (T0), midway through the intervention (T1), and at the end (T2) using ANOVAs and ANCOVAs. Intervention fidelity was measured using child and teacher surveys at T2 and analysed using Chi-square tests. RESULTS: The BTM group engaged in moderate PA for significantly more lesson time (29.4 %) than the COM group (25.8 %; p = .009, d = .53). The amount of moderate-to-vigorous PA (MVPA) during the T1 BTM lesson contributed 14.0 % to total MVPA, which was significantly more than the COM group's T1 PE lesson (11.4 %; p < .001, d = .47). The BTM group were significantly more active during the whole-day (p < .05) and the school-day (p < .01). In both groups push-up test performance increased (p < .001) and CRF test performance decreased (p < .01). Perceived exertion, enjoyment, and perceived competence increased in both groups (p < .05), but the BTM group rated their enjoyment of the T1 BTM lesson higher than the COM group rated their PE lesson (p = .02, d = .56). The children's and teachers' responses to the intervention indicated that the delivery aims of enjoyment, engagement, inclusivity, and challenge were satisfied. CONCLUSIONS: The BTM pilot programme has potential to positively impact on physical activity, fitness, and psychosocial outcomes. Further, BTM was enjoyed by the children, and valued by the teachers. This study can inform the design of a modified larger-scale cluster RCT evaluation.

A randomized, controlled trial of Panax quinquefolius extract (CVT-E002) to reduce respiratory infection in patients with chronic lymphocytic leukemia.

BACKGROUND: Chronic lymphocytic leukemia (CLL) patients are at high risk for acute respiratory illness (ARI). OBJECTIVE: We evaluated the safety and efficacy of a proprietary extract of Panax quinquefolius, CVT-E002, in reducing ARI. METHODS: This was a double-blind, placebo-controlled, randomized trial of 293 subjects with early-stage, untreated CLL conducted January-March 2009. RESULTS: ARI was common, occurring on about 10% of days during the study period. There were no significant differences of the 2 a priori primary end points: ARI days (8.5 ± 17.2 for CVT-E002 vs 6.8 ± 13.3 for placebo) and severe ARI days (2.9 ± 9.5 for CVT-E002 vs 2.6 ± 9.8 for placebo). However, 51% of CVT-E002 vs 56% of placebo recipients experienced at least 1 ARI (difference, -5%; 95% confidence interval [CI], -16% to 7%); more intense ARI occurred in 32% of CVT-E002 vs 39% of placebo recipients (difference, -7%; 95% CI, -18% to 4%), and symptom-specific evaluation showed reduced moderate to severe sore throat (P = .004) and a lower rate of grade ≥3 toxicities (P = .02) in CVT-E002 recipients. Greater seroconversion (4-fold increases in antibody titer) vs 9 common viral pathogens was documented in CVT-E002 recipients (16% vs 7%, P = .04). LIMITATIONS: Serologic evaluation of antibody titers was not tied to a specific illness, but covered the entire study period. CONCLUSION: CVT-E002 was well tolerated. It did not reduce the number of ARI days or antibiotic use; however, there was a trend toward reduced rates of moderate to severe ARI and significantly less sore throat, suggesting that the increased rate of seroconversion most likely reflects CVT-E002-enhanced antibody responses.

Exploring reasons for attrition among vulnerable and under-served sub-groups across an online integrated healthy lifestyles service during COVID-19.

OBJECTIVES: Reported health behaviour change intervention attrition rates vary considerably, from 10% to more than 80%, depending on the type and setting of the treatment programme. A better understanding of the determinants of programme adherence is required. Between March and August 2020, a convenience sample of 44 individual telephone interviews, as well as 42 online Qualtrics surveys took place. The objective was to explore perceived barriers, facilitators, and opportunities for participation, sustained participation as well as initial non-participation to better understand reasons for attrition in online delivery during the COVID-19 lockdown among vulnerable and under-served groups within an Integrated Healthy Lifestyle Service (IHLS). METHODS: A convenience sample of 44 individual telephone interviews, as well as 42 online Qualtrics surveys resulted in a total of 86 (33 male) individuals comprising intervention clients. Clients included children and young people (n = 16), manual workers (n = 7), Black, Asian or Minority Ethnic (n = 19), physical disability (n = 8), learning disability (n = 6), and those from areas of high deprivation (n = 19), as well as Integrated Healthy Lifestyle Service practitioners (n = 11). RESULTS: The study revealed that more resources and support are needed for Black, Asian or Minority Ethnic; manual worker; learning disability; and high-deprivation sub-groups in order to reduce attrition rates. Specifically, a lack of technological equipment and competence of using such equipment was identified as key barriers to initial and sustained attendance among these vulnerable and under-served sub-groups during the COVID-19 lockdown. CONCLUSION: The pattern of differences in attrition during the COVID-19 lockdown suggests that further research is required to explore how best to ensure online health behaviour change offers are scalable and accessible to all.

Exploring the awareness, attitudes, and actions (AAA) of UK adults at high risk of severe illness from COVID-19.

BACKGROUND: People at high risk of severe illness from COVID-19 have experienced greater restrictions during the pandemic, yet there is a paucity of research exploring their lived experience. OBJECTIVES: This study explored the impact of COVID-19 on people identified as at high risk of severe illness by UK Government, and in particular, the impact of the first lockdown on access to healthcare, medications and use of technological platforms. METHODS: 1038 UK adults who identified as at high risk of severe illness from COVID-19 in line with UK Government guidance or self-identified with acute or other chronic health conditions, completed the Awareness, Attitudes and Actions survey which explored the impact of COVID-19 on access to healthcare, management of long-term health condition, mental health, and health behaviours. RESULTS: Most participants reported feelings of vulnerability, anxiety and isolation, noticed that other people changed their behaviour towards them including a feeling of being stigmatised by people not categorised as high risk. Participants described the largely negative impact that the COVID-19 lockdown had on to health-related behaviours and access to healthcare, which had resulted in large declines in mental health and wellbeing. Participants also indicated disappointment at the UK Governments response and handling of the COVID-19 lockdown. IMPLICATIONS: This study provides novel evidence of the lived experience of the first COVID-19 lockdown for people identified as at high risk of severe illness. In the context of behavioural health interventions, the ubiquity of digital technologies and their adoption into day-to-day life translates into greater potential reach than traditional interventions, and consequently, greater potential for positive public health impact. Findings should be considered by policymakers and healthcare professionals to support people now and as we transition through the recovery phase with a particular emphasis on supporting mental health and changes to the management of long-term health conditions.

Personalised Accelerometer Cut-point Prediction for Older Adults' Movement Behaviours using a Machine Learning approach.

BACKGROUND AND OBJECTIVES: Body-worn accelerometers are the most popular method for objectively assessing physical activity in older adults. Many studies have developed generic accelerometer cut-points for defining activity intensity in metabolic equivalents for older adults. However, methodological diversity in current studies has led to a great deal of variation in the resulting cut-points, even when using data from the same accelerometer. In addition, the generic cut-point approach assumes that 'one size fits all' which is rarely the case in real life. This study proposes a machine learning method for personalising activity intensity cut-points for older adults. METHODS: Firstly, raw accelerometry data was collected from 33 older adults who performed set activities whilst wearing two accelerometer devices: GENEActive (wrist worn) and ActiGraph (hip worn). ROC analysis was applied to generate personalised cut-point for each data sample based on a device. Four cut-points have been considered: Sensitivity optimised Sedentary Behaviour; Specificity optimised Moderate to Vigorous Physical Activity; Youden optimised Sedentary Behaviour; and Youden optimised Moderate to Vigorous Physical Activity. Then, an additive regression algorithm trained on biodata features, that concern the individual characteristics of participants, was used to predict the cut-points. As the model output is a numeric cut-point value (and not discrete), evaluation was based on two error metrics, Mean Absolute Error and Root Mean Square Error. Standard Error of estimation was also calculated to measure the accuracy of prediction (goodness of fit) and this was used for performance comparison between our approach and the state-of-the-art. Hold-out and 10-Fold cross validation methods were used for performance validation and comparison. RESULTS: The results show that our personalised approach performed consistently better than the state-of-the-art with 10-Fold cross validation on all four cut-points considered for both devices. For the ActiGraph device, the Standard Error of estimation from our approach was lower by 0.33 (Youden optimised Sedentary Behaviour), 9.50 (Sensitivity optimised Sedentary Behaviour), 0.64 (Youden optimised Moderate to Vigorous Physical Activity) and 22.11 (Specificity optimised Moderate to Vigorous Physical Activity). Likewise, the Standard Error of estimation from our approach was lower for the GENEActiv device by 2.29 (Youden optimised Sedentary Behaviour), 41.65 (Sensitivity optimised Sedentary Behaviour), 4.31 (Youden optimised Moderate to Vigorous Physical Activity) and 347.15 (Specificity optimised Moderate to Vigorous Physical Activity). CONCLUSIONS: personalised cut-point can be predicted without prior knowledge of accelerometry data. The results are very promising especially when we consider that our method predicts cut-points without prior knowledge of accelerometry data, unlike the state-of-the-art. More data is required to expand the scope of the experiments presented in this paper.

Effects of Stocking Density on Stress Response and Susceptibility to Infectious Hematopoietic Necrosis Virus in Rainbow Trout.

The goals of this study were to examine the effect of stocking density on the stress response and disease susceptibility in juvenile rainbow trout (Oncorhynchus mykiss). Fish were sorted into one of 2 stocking densities (high density "HD", 20-40 kg/m³) or (low density, "LD", 4-8 kg/m³) and 3 stress indices (cortisol levels in serum and water, and neutrophil: lymphocyte (N:L) ratios from blood smears) were measured at multiple time points over 21 d. Serum cortisol was significantly increased at 1 h in LD samples and at 14 d in HD samples. Water cortisol concentrations were significantly higher in LD tanks as compared with HD tanks on day 14. N:L ratios were significantly higher in HD tanks on day 14 as compared with LD tanks and with baseline. The effect of stocking density on mortality after exposure to infectious hematopoietic necrosis virus (IHNV) was compared between fish held in HD or LD conditions, with or without prior acclimation to the different density conditions. No significant differences in survival were found between HD and LD treatments or between acclimated and nonacclimated treatments. Cumulative results indicate that 1) 1 to 4 gram rainbow trout did not generally demonstrate significant differences in stress indices at the density conditions tested over a 21-d period, 2) independent differences were found in 3 stress indices at day 14 after sorting into LD and HD holding conditions; and 3) LD and HD stocking densities did not have a significant effect on mortality due to IHNV.

Host immune response and acute disease in a zebrafish model of Francisella pathogenesis.

Members of the bacterial genus Francisella are highly virulent and infectious pathogens. New models to study Francisella pathogenesis in evolutionarily distinct species are needed to provide comparative insight, as the mechanisms of host resistance and pathogen virulence are not well understood. We took advantage of the recent discovery of a novel species of Francisella to establish a zebrafish/Francisella comparative model of pathogenesis and host immune response. Adult zebrafish were susceptible to acute Francisella-induced disease and suffered mortality in a dose-dependent manner. Using immunohistochemical analysis, we localized bacterial antigens primarily to lymphoid tissues and livers of zebrafish following infection by intraperitoneal injection, which corresponded to regions of local cellular necrosis. Francisella sp. bacteria replicated rapidly in these tissues beginning 12 h postinfection, and bacterial titers rose steadily, leveled off, and then decreased by 7 days postinfection. Zebrafish mounted a significant tissue-specific proinflammatory response to infection as measured by the upregulation of interleukin-1beta (IL-1beta), gamma interferon, and tumor necrosis factor alpha mRNA beginning by 6 h postinfection and persisting for up to 7 days postinfection. In addition, exposure of zebrafish to heat-killed bacteria demonstrated that the significant induction of IL-1beta was highly specific to live bacteria. Taken together, the pathology and immune response to acute Francisella infection in zebrafish share many features with those in mammals, highlighting the usefulness of this new model system for addressing both general and specific questions about Francisella host-pathogen interactions via an evolutionary approach.

Gastric cryptosporidiosis in freshwater angelfish (Pterophyllum scalare).

A freshwater angelfish (Pterophyllum scalare) hatchery experienced variable levels of emaciation, poor growth rates, swollen coelomic cavities, anorexia, listlessness, and increased mortality within their fish. Multiple chemotherapeutic trials had been attempted without success. In affected fish, large numbers of protozoa were identified both histologically and ultrastructurally associated with the gastric mucosa. The youngest cohort of parasitized fish was the most severely affected and demonstrated the greatest morbidity and mortality. The protozoa were morphologically most consistent with Cryptosporidium. All of the protozoan life stages were identified ultrastructurally and protozoal genomic DNA was isolated from parasitized tissue viscera and sequenced. Histological, ultrastructural, genetic, and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium.

Using formative research with older adults to inform a community physical activity programme: Get Healthy, Get Active.

AIM: The purpose of this formative study was to explore current knowledge and attitudes towards physical activity, as well as perceived barriers, facilitators and opportunities for physical activity participation among older adults living in the community. The findings have subsequently informed the design, delivery and recruitment strategies of a local community physical activity intervention programme which forms part of Sport England's national Get Healthy, Get Active initiative. BACKGROUND: There is a growing public health concern regarding the amount of time spent in sedentary and physical activity behaviours within the older adult population. METHODS: Between March and June 2016, 34 participants took part in one of six focus groups as part of a descriptive formative study. A homogenous purposive sample of 28 community dwelling white, British older adults (six male), aged 65-90 years (M=78, SD=7 years) participated in one of five focus group sessions. An additional convenience pragmatic sub-sample of six participants (three male), aged 65-90 years (M=75, SD=4 years), recruited from an assisted living retirement home participated in a sixth focus group. Questions for focus groups were structured around the PRECEDE stage of the PRECEDE-PROCEDE model of health programme design, implementation and evaluation. Questions addressed knowledge, attitudes and beliefs towards physical activity, as well as views on barriers and opportunities for physical activity participation. All data were transcribed verbatim. Thematic analysis was then conducted with outcomes represented as pen profiles. FINDINGS: Consistent views regarding both the potential physical and psychosocial benefits of physical activity were noted regardless of living status. The themes of, opportunities and awareness for physical activity participation, cost, transport, location and season/weather varied between participants living in an assisted living retirement home and community dwelling older adults. Further comparative research on the physical activity requirements of older adults living in assisted living versus community settings are warranted.

Fluorescent light exposure incites acute and prolonged immune responses in zebrafish (Danio rerio) skin.

Artificial light produces an emission spectrum that is considerably different than the solar spectrum. Artificial light has been shown to affect various behavior and physiological processes in vertebrates. However, there exists a paucity of data regarding the molecular genetic effects of artificial light exposure. Previous studies showed that one of the commonly used fluorescent light source (FL; 4100K or "cool white") can affect signaling pathways related to maintenance of circadian rhythm, cell cycle progression, chromosome segregation, and DNA repair/recombination in the skin of male Xiphophorus maculatus. These observations raise questions concerning the kinetics of the FL induced gene expression response, and which biological functions become modulated at various times after light exposure. To address these questions, we exposed zebrafish to 4100K FL and utilized RNA-Seq to assess gene expression changes in skin at various times (1 to 12h) after FL exposure. We found 4100K FL incites a robust early (1-2h) transcriptional response, followed by a more protracted late response (i.e., 4-12h). The early transcriptional response involves genes associated with cell migration/infiltration and cell proliferation as part of an overall increase in immune function and inflammation. The protracted late transcriptional response occurs within gene sets predicted to maintain and perpetuate the inflammatory response, as well as suppression of lipid, xenobiotic, and melatonin metabolism.

A phase III, double-blind, placebo-controlled prospective randomized clinical trial of d-threo-methylphenidate HCl in brain tumor patients receiving radiation therapy.

PURPOSE: The quality of life (QOL) and neurocognitive function of patients with brain tumors are negatively affected by the symptoms of their disease and brain radiation therapy (RT). We assessed the effect of prophylactic d-threo-methylphenidate HCl (d-MPH), a central nervous system (CNS) stimulant on QOL and cognitive function in patients undergoing RT. METHODS AND MATERIALS: Sixty-eight patients with primary or metastatic brain tumors were randomly assigned to receive d-MPH or placebo. The starting dose of d-MPH was 5 mg twice daily (b.i.d.) and was escalated by 5 mg b.i.d. to a maximum of 15 mg b.i.d. The placebo was administered as one pill b.i.d. escalating three pills b.i.d. The primary outcome was fatigue. Patients were assessed at baseline, the end of radiation therapy, and 4, 8, and 12 weeks after brain RT using the Functional Assessment of Cancer Therapy with brain and fatigue (FACIT-F) subscales, as well as the Center for Epidemiologic Studies Scale and Mini-Mental Status Exam. RESULTS: The Mean Fatigue Subscale Score at baseline was 34.7 for the d-MPH arm and 33.3 for the placebo arm (p = 0.61). At 8 weeks after the completion of brain RT, there was no difference in fatigue between patient groups. The adjusted least squares estimate of the Mean Fatigue Subscale Score was 33.7 for the d-MPH and 35.6 for the placebo arm (p = 0.64). Secondary outcomes were not different between the two treatment arms. CONCLUSIONS: Prophylactic use of d-MPH in brain tumor patients undergoing RT did not result in an improvement in QOL.

Associations between retirement reasons, chronic pain, athletic identity, and depressive symptoms among former professional footballers.

BACKGROUND: Retirement from professional sport has been recognised as a major psychological stressor, and there is a need to identify factors that increase the risk of mental health problems after career termination. The current study examined associations between career-ending injury, chronic pain, athletic identity, and depressive symptomology in retired professional footballers. METHODS: A cross-sectional study was performed with 307 retired male footballers who had played within a professional United Kingdom league. Participants completed measures of depressive symptoms (Short Depression-Happiness Scale), chronic pain (Pain Intensity Numerical Rating Scale), and athletic identity (Athletic Identity Measurement Scale), and reported their reasons for retirement. RESULTS: A total of 48 participants (16%) met the cut-off score for possible cases of clinically relevant depression. These participants were more recently retired, and had higher athletic identity than those without depressive symptoms. Former players with depressive symptoms were more likely to cite injury as a retirement reason, and report higher levels of ongoing injury-related pain. Multivariate logistic regression revealed that the presence of depressive symptoms was independently associated with retirement through injury (OR = 3.44; 95% CI = 1.39, 8.51), higher pain levels (OR = 1.38; 95% CI = 1.02, 1.86), and increased athletic identity (OR = 1.28; 95% CI = 1.14, 1.44). CONCLUSIONS: Career-ending injury is strongly associated with higher odds of depressive symptomology during retirement, while experiencing chronic pain, and maintaining a high sense of athletic identity, are additional potential contributors.

A Dynamic Anesthesia System for Long-Term Imaging in Adult Zebrafish.

Long-term in vivo imaging in adult zebrafish (i.e., 1-24 h) has been limited by the fact that regimens for long-term anesthesia in embryos and larvae are ineffective in adults. Here, we examined the potential for dynamic administration of benzocaine to enable long-term anesthesia in adult zebrafish. We developed a computer-controlled perfusion system comprised of programmable peristaltic pumps that enabled automatic exchange between anesthetic and system water. Continuous administration of benzocaine in adult zebrafish resulted in a mean time to respiratory arrest of 5.0 h and 8-h survival of 14.3%. We measured characteristic sedation and recovery times in response to benzocaine, and used them to devise an intermittent dosing regimen consisting of 14.5 min of benzocaine followed by 5.5 min of system water. Intermittent benzocaine administration in adult zebrafish resulted in a mean time to respiratory arrest of 7.6 h and 8-h survival of 71.4%. Finally, we performed a single 24-h trial and found that intermittent dosing maintained anesthesia in an adult zebrafish over the entire 24-h period. In summary, our studies demonstrate the potential for dynamic administration of benzocaine to enable prolonged anesthesia in adult zebrafish, expanding the potential for imaging in adult physiologies that unfold over 1-24 h.

Effect of water hardness on oocyte quality and embryo development in the African clawed frog (Xenopus laevis).

Husbandry and health of the African clawed frog, Xenopus laevis, greatly influences the quality of oocytes produced. One factor affecting oocyte quality is the water conditions in which females are maintained. Dechlorination and adequate salt concentration are known to affect oocytes, but water hardness has not been considered an important factor in Xenopus husbandry by the research community. We found that, when females were kept in soft water or water with marine salts alone, even when it was cooled to 17 to 18 degrees C, the quality of oocytes decreased; only 20 to 25% of resulting embryos developed to tailbud stages. Survival and normal development of embryos increased significantly within one month of addition to the laboratory housing water of salts that mimic conditions in African Rift Valley lakes. These salts greatly increased water hardness; development of embryos to tailbud stages remained high (50 to 70% on average) for more than a year after their addition to the water housing females. Water from South African ponds where X. laevis are collected, and from wells used by the major suppliers of X. laevis, also was moderately to very hard. Our results suggest that X. laevis is naturally adapted to hard water, and indicate that increasing general hardness during laboratory housing is more important for oocyte quality and embryo development than is increasing carbonate hardness (alkalinity) in the water used to house females.

Susceptibility of zebrafish (Danio rerio) to a model pathogen, spring viremia of carp virus.

To improve our understanding of the genetic basis of fish disease, we developed a pathogen model, using zebrafish (Danio rerio) and spring virema of carp virus (SVCV). Replicate groups of 10 fish were acclimated to 20 or 24 degrees C, then were exposed to SVCV concentrations of 10(3) to 10(5) plaque-forming units per milliliter (PFU/ml) of water and observed daily. In a second trial, fish were acclimated to 15 degrees C, and replicate groups of 10 fish were exposed to SVCV at a concentration of 10(5) PFU/ml; however, the temperature was raised 1 degrees C/wk. Moribund fish were collected for histologic examination, and dead fish were assayed for virus by use of cell culture and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Mortality exceeded 50% in fish exposed to 10(5) PFU of SVCV/ml at the lower temperatures. Clinical signs of disease became evident seven days after viral exposure and were observed most consistently in fish of the 10(5) PFU/ml groups. Affected zebrafish were anorectic and listless, with epidermal petechial hemorrhages followed by death. Use of plaque assays and RT-PCR analysis confirmed presence of SVCV at titers > or = 10(4) PFU/g of tissue. Histologic lesions included multifocal brachial necrosis and melanomacrophage proliferation in gills, liver, and kidneys. These results indicate that zebrafish are susceptible to infection by SVCV under conditions that mimic a natural route of exposure.

Gyrodactylid ectoparasites in a population of rainbow trout (Oncorhynchus mykiss).

A colony of rainbow trout (Oncorhynchus mykiss) in a decentralized aquatic animal facility was noted to have an increase in morbidity and mortality (from 4 or 5 fish each month to 3 or 4 fish daily) approximately 2 wk after experimental procedures began. The primary clinical signs were erratic swimming behavior and 'flashing' of fish against surfaces within housing enclosures. Moribund and normal rainbow trout were presented alive for diagnostic evaluation; samples of water from housing enclosures were provided for water quality assessment. The trout were determined to be infected with gyrodactylids, a common monogenean ectoparasite of the skin and gills in both marine and freshwater fish. This case report describes the diagnosis, pathology, and treatment of gyrodactylids and husbandry modifications associated with the resolution of this clinical aquatic-animal case.

Sanitization of an automatic reverse-osmosis watering system: removal of a clinically significant biofilm.

During environmental monitoring of our institution's rodent watering systems, one vivarium was found to have high bacterial loads in the reverse-osmosis (RO) automatic water system. These findings prompted evaluation of the entire RO water production and distribution system. Investigation revealed insufficient rack and RO system sanitization, leading to heavy biofilm accumulation within the system. Approximately 2 wk after discovery in the water system, one of the bacterial organisms isolated in the water supply, Sphingomonas paucimobilis, was isolated from a peritoneal abscess of a severely immunodeficient B6. Cg-Slc11a1(r) Rag1(tm1Mom)/Cwi mouse housed in the same vivarium, suggesting that rodents drinking from this system were being exposed randomly to fragments of biofilm. Plans were developed to sanitize the entire system. Hypercholorination was used first, followed by treatment with a combination of peracetic acid and hydrogen peroxide. Between system sanitizations, a low-level chlorine infusion was added to the system as a biocide. Heterotrophic plate counts and bacterial isolation were performed on water samples obtained before and after sanitization procedures. We here discuss the process of identifying and correcting this important water-quality issue.