Barriers to Care for Pediatric Rural Medulloblastoma Patients Receiving Craniospinal Proton Radiotherapy without In-State Facilities

PURPOSE/OBJECTIVE(S)

Medulloblastoma represents ∼20% of all pediatric brain malignancies. The preferred treatment modality for craniospinal irradiation (CSI) has evolved to be proton beam therapy to reduce late toxicities including secondary malignancy. Access to proton therapy centers is more limited in states without one. Barriers to access for rural patients are underreported in the literature.

MATERIALS/METHODS

Patients <25 years old with a diagnosis of medulloblastoma were identified from a tumor registry at a rural academic center. A chart review was conducted to identify specific barriers to proton beam CSI. Descriptive analyses were performed to describe this cohort and their barriers.

RESULTS

We identified a total of 18 patients diagnosed between 2000 and 2022. The mean age was 10 years old (range 11 months - 20 years). 2 patients were excluded who had minimal documentation. 7 patients were diagnosed before 1/1/2014, a cutoff after which protons were considered more often in this patient population. Patient demographics were 39% female, 61% male, 22% Black, and 72% White, 6% Hispanic. 3 patients received protons. 2 patients had recurrence and 3 patients developed secondary malignancy. Out of 18 patients, proton therapy was discussed with 11 patients. The rates of documented barriers to radiotherapy for the cohort at large (n = 18) and for those where proton therapy was discussed in particular (n = 11) are as follows (cohort at large / had discussion): 4(22%) / 4(36%) difficulty obtaining insurance approval, 4(22%) / 4(36%) inpatient medical needs, 5(28%) / 5(46%) outpatient medical needs, 4(22%) / 4(36%) family scheduling conflicts, 3(17%) / 3(27%) travel costs/financial burdens, 4(22%) / 4(36%) not a clinical trial candidate, 3(17%) / 3(27%) radiotherapy delay, 9(50%) / 5(46%) other barriers to non-radiotherapy care. For the cohort at large or for those with proton therapy discussions, there were no significant associations between white and underrepresented minorities for the aforementioned barriers to care.

CONCLUSION

To our knowledge, this is the first study that identifies patient barriers to accessing proton beam CSI for medulloblastoma patients from a rural tertiary care center without in-state proton radiotherapy centers. This study yields insight into the particular barriers encountered by these patients and their families, allowing clinical teams to identify potential issues in an effort to overcome those barriers. Advocacy for access to care on behalf of this vulnerable patient population may be required by our field on a state and national level.

Rural Pediatric Radiation Oncology in the Era of COVID-19: A Single Institution Analysis

PURPOSE/OBJECTIVE(S)

Health inequities have recently gained prominence in public consciousness as a result of the COVID-19 pandemic. Rural access to care was particularly impacted regarding delays in cancer screening, diagnosis, and treatment. The fractionated nature of radiotherapy creates transportation burdens in this population. We reviewed our institutional experience with pediatric radiotherapy at a tertiary academic center serving a primarily rural population over a large geographic area.

MATERIALS/METHODS

The financial burden of radiotherapy in pediatric patients in our database was modeled using cost-analysis. The cost of transportation using distance to our facility and the IRS-assessed tax value per mile was calculated. Correlative analyses were conducted to evaluate the association of radiotherapy delivered pre- vs. post-COVID with patient race, age at diagnosis, and distance from our institution. Analyses were conducted with two-tailed Pearson correlations for transportation cost vs. age at diagnosis. Mann-Whitney U testing was used to analyze transportation cost vs. patient race. Fisher's Exact Test was used to analyze the trends between tumor primary sites pre- and post-COVID.

RESULTS

There was a statistically significant increase in brain tumors vs. all others from 9.1% to 66.7% post-COVID (p = 0.029). When comparing patients treated prior to the onset of the COVID-19 pandemic in 2020 to those treated during the peak years of the pandemic in 2020-2021, there was no difference in the average distance traveled for treatment. However, the mean cost of transportation for pediatric patients undergoing radiotherapy prior to COVID-19 was $266 USD (median = $331), vs. a mean of $535 (median = $378) for patients treated during 2020-2021. For patients treated in 2022, after the height of COVID-19, the mean cost of transportation was $501 (median = $432). No statistically significant differences were found between the cost of transportation and patient race or age at diagnosis before vs. after the onset of COVID-19.

CONCLUSION

Our results highlight the importance of understanding barriers to care and what type of resources are most impactful to rural pediatric patients at our center. The rise of transportation costs for radiotherapy following the COVID-19 pandemic may indicate an additional barrier to care, potentially associated with increasing inflation, for rural pediatric patients that is underreported in the literature. The rise in the relative prevalence of brain tumors at our institution during this period warrants further investigation.

A SEER Database Cohort of 547 Patients with Non-Squamous Cell Carcinoma of the Penis: Clinical Characteristics and Outcomes

PURPOSE/OBJECTIVE(S)

Little research has investigated the prevalence and distribution of the diverse pathologies of non-squamous cell carcinoma (non-SCC) of the penis. Although rare in clinical practice, these cancers have become a focus of greater importance among patients, clinicians, and researchers, particularly in developing countries. The principal objective of this study was to analyze the major types of penile non-squamous cell carcinoma, elucidate common treatment pathways, and highlight outcomes including 5-year survival.

MATERIALS/METHODS

The Surveillance, Epidemiology and End Results (SEER) database was queried between 2000 to 2018 to identify a retrospective cohort of patients with penile non-SCC. Demographic information, cancer characteristics, diagnostic methods, treatments administered, and survival were investigated.

RESULTS

A total of 547 cases of penile non-SCC were included in the analysis. The most prevalent non-SCC cancers included epithelial neoplasms, not otherwise specified (15.4%), unspecified neoplasms (15.2%), basal cell neoplasms (13.9%), blood vessel tumors (13.0%), nevi and melanomas (11.7%), and ductal and lobular neoplasms (9.9%). Data for the nine most prevalent neoplasms are included in Table 1. Over half (56.7%) of patients elected to undergo surgical intervention. Patients rarely received systemic therapy (3.8%) or radiation (4.0%). Five-year survival was 35.5%. Median survival was 5.2 years (62.7 months). Patients who underwent surgery had greater annual survival for 0 to 10 years compared to those who did not have surgery. Significant differences in survival were found between patients who had regional, localized, and distant metastases (p<0.05). A significant difference in survival was found for patients married at diagnosis versus those who were unmarried at diagnosis (p<0.05). Lower survival rates were observed for patients older than 70 years.

CONCLUSION

Although less prevalent than squamous cell carcinoma, penile non-SCC encompasses a diverse set of neoplasms. Patients in this cohort had a high utilization of surgical management leading to superior outcomes compared to those not receiving surgery. Radiation is an uncommonly pursued treatment pathway. Patient demographics and socioeconomic variables such as marital status may be valuable when investigating cancer outcomes. This updated database analysis can help inform diagnosis, management, and clinical outcomes for this rare group of malignancies.

Use of multiplate electrode aggregometry for personalisonalisation of antiplatelet therapy in left ventricular assisst device patients

Funding Acknowledgements

Type of funding sources: None.

Background

The use of Left Ventricular Assist Devices (LVAD) has noticeably improved the survival for patients with advanced heart failure.  However, this treatment is associated with significant adverse effects. Personalisation of antiplatelet therapy is a key in control and reduction of bleeding/thromboembolic complications of this treatment. However, ISHLT and the manufacturer still recommend unified treatment of 150 mg of acetylsalicylic acid for all LVAD patients. In our centre, we base the treatment decision on clinical picture and patient’s responsiveness to antiplatelet therapy. 

The treatment of choice is acetylsalicylic acid in doses 37.5 mg (1 patient), 75 mg (25 patients) and 150 mg (33 patients). For patients unresponsive or intolerant to acetylsalicylic acid we use 75 mg of clopidogrel, currently 9 patients.  1 patient receives both, 75 mg clopidogrel and 75 mg acetylsalicylic acid. 

Purpose

To gain a better understanding of the platelets function and patients" responses to antiplatelet therapy. In aim to reduce the prevalence of bleeding/thromboembolic related adverse events in LVAD patients, and therefore improve patients outcome.

Methods

In 2020, we decided to introduce a structured/test-based approach to antiplatelet therapy in this patients group. With the use of Multiplate Electrode Aggregometry (MEA) we have attempted to diagnose platelet disorders and monitor effectiveness of antiplatelet therapy. Based on MEA platlets inhibition test we were able to tailor the therapy. 

The retrospective audit was conducted with inclusion criteria;

1. Thromboembolic events include pump thrombosis and any other ischemic complications. Bleeding events contains gastrointestinal (GI) and central nervous system (CNS) events.

2. Any thromboembolic and bleeding events after starting antiplatelet therapy, in the first year after LVAD implantation

Results

The tables below presents reduction in both thromboembolic and bleeding complications.

Conclusion

Presented data can be interpreted that, the test-based approach to antiplatelet therapy may be beneficial in limiting the adverse effects of LVAD therapy. However, it needs to be acknowledged that the observation was carried out on a small group of the patients, over a short period of time. Therefore, an extended period of observation is recommended to obtain further data.

Rumen function and grazing behavior of early-lactation dairy cows supplemented with fodder beet

Fodder beet (FB) is a source of readily fermentable carbohydrate that can mitigate early spring herbage deficits and correct the negative energy balance experienced during early lactation in pastoral dairy systems of New Zealand. However, the low-fiber and high-soluble carbohydrate content of both FB bulb and spring herbage are factors that promote subacute ruminal acidosis, impairing rumen function and limiting the marginal milk production response to supplement. In a crossover experiment, 8 Holstein Friesian × Jersey early-lactation dairy cows were used to test the effect of supplementing 16 kg of dry matter (DM) of a grazed perennial ryegrass herbage with 6 kg of DM/d of FB bulb (FBH) versus herbage only (HO) on changes in rumen function and grazing behavior. Following 20 d of adaptation to diets, DM disappearance (%) of FB bulb (FBH cows only) and herbage were measured in sacco, separately. Cows were fasted overnight, and the ruminal contents were bailed the following morning (~0930 h) again to determine the pool size of volatile fatty acids, ammonia, and particle size of digesta, as well as to estimate the rate of ruminal outflow and degradation of neutral detergent fiber. The FBH diet did not alter DM intake, milk yield, or milk solid (fat + protein) production compared with HO. Supplementation of herbage with FB reduced ruminal pH compared with HO between ~0800 h and 1300 h each day. During each period, 1 cow experienced severe subacute ruminal acidosis (pH <5.6 for >180 min/d) during final adaptation to the target FB allocation. The FBH diet reduced the ruminal pool of acetate and ammonia, but increased the ruminal pool of butyrate and lactate compared with HO. When fed FB, rumination and grazing time increased and grazing intensity declined compared with cows fed HO. Despite increased rumination, the comminution of large particles declined 28% between the first and second rumen bailing when cows were fed FB, and in sacco DM disappearance of perennial ryegrass declined 18% compared with cows fed HO. These results indicate that grazing dairy cows supplemented with FB (40% of daily intake) increase rumination and mastication intensity to counteract reduced ruminal degradation of ryegrass herbage due to low ruminal fluid pH.

Predation by introduced cats Felis catus on Australian frogs: compilation of species records and estimation of numbers killed

Abstract ContextWe recently estimated the numbers of reptiles, birds and mammals killed by cats (Felis catus) in Australia, with these assessments providing further evidence that cats have significant impacts on Australian wildlife. No previous studies have estimated the numbers of frogs killed by cats in Australia and there is limited comparable information from elsewhere in the world. AimsWe sought to (1) estimate the numbers of frogs killed by cats in Australia and (2) compile a list of Australian frog species known to be killed by cats. MethodsFor feral cats, we estimated the number of frogs killed from information on their frequency of occurrence in 53 cat dietary studies (that examined stomach contents), the mean number of frogs in dietary samples that contained frogs, and the numbers of cats in Australia. We collated comparable information for take of frogs by pet cats, but the information base was far sparser. Key resultsFrogs were far more likely to be reported in studies that sampled cat stomachs than cat scats. The mean frequency of occurrence of frogs in cat stomachs was 1.5%. The estimated annual per capita consumption by feral cats in Australia’s natural environments is 44 frogs, and, hence, the annual total take is estimated at 92 million frogs. The estimated annual per capita consumption by pet cats is 0.26 frogs, for a total annual kill of one million frogs by pet cats. Thirty native frog species (13% of the Australian frog fauna) are known to be killed by cats: this tally does not include any of the 51 threatened frog species, but this may simply be because no cat dietary studies have occurred within the small ranges typical of threatened frog species. ConclusionsThe present study indicated that cats in Australia kill nearly 100 million frogs annually, but further research is required to understand the conservation significance of such predation rates. ImplicationsThe present study completed a set of reviews of the impacts of cats on Australian terrestrial vertebrates. Cat predation on Australian frogs is substantial, but is likely to be markedly less than that on Australian reptiles, birds and mammals.

Enhancement of saquinavir absorption and accumulation through the formation of solid drug nanoparticles

Background

Nanotechnology is now considered a promising drug delivery method for orally administered hydrophobic drugs to their sites of action. The effect of nanodispersion on cellular transport and accumulation of saquinavir (SQV) was investigated.

Methods

The transport of five solid drug nanoparticle (SDN) SQV formulations along Caco-2 cell monolayers (CCM) was compared to that of standard SQV. The SDNs were prepared using SQV mesylate (20%), Pluronic F127 (10%) plus five other excipients (HPMC, PVP, PVA, Lecithin S75 and Span 80) in different proportions. Cellular accumulation in CEM parental and CEMVBL (P-gp overexpressing) cells was conducted to ascertain the effect of nanodispersion on P-gp mediated efflux of SQV. All SDN formulations were dissolved in water, whereas SQV in DMSO to improve solubility. Quantification was via HPLC.

Results

From transport results, an SDN sample composed of SQV mesylate/Pluronic F127 plus HPMC (70%) and had a 24% increase in apparent absorption compared to standard SQV, largely driven by a 38% reduction in basolateral to apical permeation. Additionally, the formulation and two others (SQV mesylate/Pluronic F127 alone; and + HPMC (65%)/Lecithin [5%]) accumulated more significantly in CEM cells, suggesting enhanced delivery to these cells. Moreover, accumulation and transport of the three SDNs compared well to that of SQV despite being dissolved in water, suggestive of improved dissolution. The inclusion of PVA resulted in increased efflux.

Conclusion

The use of HPMC and Pluronic F127 produced SQV SDNs with improved permeation in Caco-2 cells and improved accumulation in CEM cells, but negative effects with PVA.

ON THE USE OF A CENTRAL THORIUM FUEL ELEMENT IN PRESSURE-TUBE HEAVY-WATER REACTOR FUEL BUNDLES

An incremental approach to introducing thorium to the conventional pressure-tube heavy-water reactor natural uranium fuel cycle is investigated. The approach involves the replacement of the centre fuel element of the bundle with an element of thorium dioxide. Increasing the operating margin of a key safety parameter, the coolant void reactivity, is a prime motivating factor. The analyses showed that the simple use of a single pin of thorium is unlikely to be economically advantageous due to a large burnup penalty and increased fuel costs. However, a slight reduction in the void reactivity is observed, and this approach does allow the exploitation of the energy potential available in thorium as an alternative nuclear fuel resource through the development of a U-233 resource. This bundle concept may also be advantageous from a fuel disposal point of view, as the fuel requires less time in storage before emplacement in a deep geological repository.

How many reptiles are killed by cats in Australia?

Context Feral cats (Felis catus) are a threat to biodiversity globally, but their impacts upon continental reptile faunas have been poorly resolved. Aims To estimate the number of reptiles killed annually in Australia by cats and to list Australian reptile species known to be killed by cats. Methods We used (1) data from >80 Australian studies of cat diet (collectively >10 000 samples), and (2) estimates of the feral cat population size, to model and map the number of reptiles killed by feral cats. Key results Feral cats in Australia’s natural environments kill 466 million reptiles yr–1 (95% CI; 271–1006 million). The tally varies substantially among years, depending on changes in the cat population driven by rainfall in inland Australia. The number of reptiles killed by cats is highest in arid regions. On average, feral cats kill 61 reptiles km–2 year–1, and an individual feral cat kills 225 reptiles year–1. The take of reptiles per cat is higher than reported for other continents. Reptiles occur at a higher incidence in cat diet than in the diet of Australia’s other main introduced predator, the European red fox (Vulpes vulpes). Based on a smaller sample size, we estimate 130 million reptiles year–1 are killed by feral cats in highly modified landscapes, and 53 million reptiles year–1 by pet cats, summing to 649 million reptiles year–1 killed by all cats. Predation by cats is reported for 258 Australian reptile species (about one-quarter of described species), including 11 threatened species. Conclusions Cat predation exerts a considerable ongoing toll on Australian reptiles. However, it remains challenging to interpret the impact of this predation in terms of population viability or conservation concern for Australian reptiles, because population size is unknown for most Australian reptile species, mortality rates due to cats will vary across reptile species and because there is likely to be marked variation among reptile species in their capability to sustain any particular predation rate. Implications This study provides a well grounded estimate of the numbers of reptiles killed by cats, but intensive studies of individual reptile species are required to contextualise the conservation consequences of such predation.

Integration of the social environment in a mobility ontology for people with motor disabilities

BACKGROUND

Our contemporary understanding of disability is rooted in the idea that disability is the product of human-environment interaction processes. People may be functionally limited, but this becomes a disability only when they engage with their immediate social and physical environments. Any attempt to address issues of mobility in relation to people with disabilities should be grounded in an ontology that encompasses this understanding.

PURPOSE

The objective of this study is to provide a methodology to integrate the social and physical environments in the development of a mobility ontology for people with motor disabilities (PWMD).

METHODS

We propose to create subclasses of concepts based on a Nature-Development distinction rather than creating separate social and physical subclasses. This allows the relationships between social and physical elements to be modelled in a more compact and efficient way by specifying them locally within each entity, and better accommodates the complexities of the human-environment interaction as well. Based on this approach, an ontology for mobility of PWMD considering four main elements - the social and physical environmental factors, human factors, life habits related to mobility and possible goals of mobility - is presented.

CONCLUSIONS

We demonstrate that employing the Nature-Development perspective facilitates the process of developing useful ontologies, especially for defining the relationships between the social and physical parts of the environment. This is a fundamental issue for modelling the interaction between humans and their social and physical environments for a broad range of applications, including the development of geospatial assistive technologies for navigation of PWMD. Implications for rehabilitation The proposed perspective may actually have much broader interests beyond the issue of disability - much of the interesting dynamics in city development arises from the interaction between human-developed components - the built environment and its associated entities - and natural or organic components. The proposed approach facilitates the process of developing useful ontologies, especially for defining the relationships between the social and physical parts of the environment. This is a fundamental issue for modeling the interaction between human -specially people with disabilities -and his social and physical environments in a broad range of domains and applications, such as Geographic Information Systems and the development of geospatial assistive technologies for navigation of people with disabilities, respectively.

Drug-transporter mediated interactions between anthelminthic and antiretroviral drugs across the Caco-2 cell monolayers

BACKGROUND

Drug interactions between antiretroviral drugs (ARVs) and anthelminthic drugs, ivermectin (IVM) and praziquantel (PZQ) were assessed by investigating their permeation through the Caco-2 cell monolayers in a transwell. The impact of anthelminthics on the transport of ARVs was determined by assessing the apical to basolateral (AP → BL) [passive] and basolateral to apical (BL → AP) [efflux] directions alone, and in presence of an anthelminthic. The reverse was conducted for the assessment of the influence of ARVs on anthelminthics.

METHODS

Samples from the AP and BL compartments were taken at 60, 120, 180 and 240 min and quantified either by HPLC or radiolabeled assay using a liquid scintillating counter for the respective drugs. Transepithelial resistance (TEER) was used to assess the integrity of the monolayers. The amount of compound transported per second (apparent permeability, Papp) was calculated for both AP to BL (PappAtoB), and BL to AP (PappBtoA) movements. Samples collected after 60 min were used to determine the efflux ratio (ER), quotient of secretory permeability and absorptive permeability (PappBL-AP/PappAP-BL). The reverse, (PappAP-BL/PappBL-AP) constituted the uptake ratio. The impact of SQV, EFV and NVP on the transport of both IVM and PZQ were investigated. The effect of LPV on the transport of IVM was also determined. The influence of IVM on the transport of SQV, NVP, LPV and EFV; as well as the effect PZQ on the transport of SQV of was also investigated, and a two-tailed p value of <0.05 was considered significant.

RESULTS

IVM significantly inhibited the efflux transport (BL → AP movement) of LPV (ER; 6.7 vs. 0.8, p = 0.0038) and SQV (ER; 3.1 vs. 1.2 p = 0.00328); and increased the efflux transport of EFV (ER; 0.7 vs. 0.9, p = 0.031) suggesting the possibility of drug transporter mediated interactions between the two drugs. NVP increased the efflux transport of IVM (ER; 0.8 vs. 1.8, p = 0.0094).

CONCLUSIONS

The study provides in vitro evidence of potential interactions between IVM, an anthelminthic drug with antiretroviral drugs; LPV, SQV, NVP and EFV. Further investigations should be conducted to investigate the possibility of in vivo interactions.

Intracellular accumulation of Praziquantel in T lymphoblastoid cell lines, CEM (parental) and CEMVBL(P-gp-overexpressing)

Background

Praziquantel (PZQ) is an antihelminthic drug whose P-glycoprotein (P-gp) substrate specificity has not been conclusively characterized. We investigated its specificity by comparing its in vitro intracellular accumulation in CEM (parental), and CEMvbl cells which over express P-gp, a drug efflux transporter. Saquinavir (SQV), a known substrate of efflux transporters was used as control.

Methods

A reversed phase liquid chromatography method was developed to simultaneously quantify PZQ and SQV in cell culture media involving involved a liquid - liquid extraction followed by ultra-high performance liquid chromatography using a Hypurity C₁₈ column and ultraviolet detection set at a wavelength of 215 nm. The mobile phase consisted of ammonium formate, acetonitrile and methanol (57:38:5 v/v). Separation was facilitated via isocratic elution at a flow rate of 1.5 ml/min, with clozapine (CLZ) as internal standard. This was validated over the concentration range of 1.6 to 25.6 μM for all analytes. Intracellular accumulation of SQV in CEMvbl was significantly lower compared to that in CEM cells (0.1 ± 0.031 versus 0.52 ± 0.046, p = 0.03 [p <0.05]).

Results

Accumulation of PZQ in both cell lines cells were similar (0.05 ± 0.005 versus 0.04 ± 0.009, p = 0.4) suggesting that it is not a substrate of P-gp in CEM cells. In presence tariquidar, a known inhibitor of P-gp, the intracellular accumulation of SQV in CEMvbl cells increased (0.52 ± 0.068 versus 0.61 ± 0.102, p = 0.34 in CEM cells and 0.09 ± 0.015 versus 0.56 ± 0.089, p = 0.029 [p < 0.05] in CEMvbl cells). PZQ did not significantly affect the accumulation of SQV in either CEM (0.52 ± 0.068 versus 0.54 ± 0.061, p = 0.77), or in CEMvbl cells (0.09 ± 0.015 versus 0.1 ± 0.031, p = 0.89) cells compared to tariquidar, implying that PZQ is not an inhibitor of P-gp in CEMvbl cells.

Conclusions

PZQ is neither a substrate nor an inhibitor of the efflux drug transporter P-gp in T-lymphoblastoid cells, CEM and CEMvbl. We also report a simple, accurate and precise method for simultaneous quantification of PZQ and SQV.

The effect of feeding maize silage 1 h or 9 h before the herbage meal on dry matter intake, milk production, nitrogen partitioning and rumen function of lactating dairy cows

The study was conducted to evaluate the effect of the timing of feeding maize silage before a short herbage meal on dry matter (DM) intake, milk production, nitrogen (N) partitioning and rumen function of lactating dairy cows. Ten lactating, pregnant, Friesian × Jersey rumen-fistulated dairy cows aged 4–5 years were blocked in pairs by milksolids (MS; sum of protein and fat) production (1.73 ± 0.097 kg MS/cow.day; mean ± s.d.), bodyweight (519 ± 24.7 kg), days in milk (163 ± 12.5), and body condition score (3.9 ± 0.21). Cows within pairs were randomly allocated to one of two treatments: (1) five cows were offered one-third of their estimated total DM intake (5 kg/cow.day) as maize silage after the afternoon milking at 1500 hours, ~1 h before herbage was provided (1BH); (2) five cows were offered one-third of their estimated total DM intake as maize silage after morning milking at 0700 hours, ~9 h before herbage was provided (9BH). All cows were offered two-thirds of their total estimated DM intake (11 kg/cow.day) over a period of 4 h from 1600 hours to 2000 hours as freshly cut perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens) in an indoor system. Cows were adapted to diets for 9 days (Days 1–9), followed by 5 days of measurement (Days 10–14). Maize silage DM intake did not differ between treatments averaging 5.1 kg DM/cow.day. Herbage DM intake was greater (P = 0.02) for 9BH (11.2 kg DM/cow.day) than 1BH (10.4 kg DM/cow.day). Milk yield (P = 0.001) and MS production (P = 0.08) were greater for 9BH than 1BH (18.8 vs 15.4 kg/cow.day and 1.63 vs 1.48 kg MS/cow.day, respectively). There was no effect of time of supplementation on N partitioned to milk, faeces, or urine. The purine derivatives to creatinine ratio, as an indication of microbial protein production, was greater (P = 0.04) for 9BH than 1BH. Daily mean rumen pH and the concentration of total rumen volatile fatty acids, acetate, butyrate, and ammonia N were not affected by treatment. However, the peak concentration of ruminal ammonia N was 27% lower (P < 0.05) for 9BH than 1BH. The concentration of non-esterified fatty acid (P = 0.03) and beta-hydroxy butyric acid (P = 0.01) were greater for 1BH than 9BH (0.14 vs 0.09 and 0.81 vs 0.71 mmol/L, respectively). These results indicate that under herbage feed restriction, altering the time of supplementation relative to the herbage meal can increase herbage DM intake and subsequent milk production.

Allocentric Spatial Performance Higher in Early-Blind and Sighted Adults Than in Retinopathy-of-Prematurity Adults

The question as to whether people totally blind since infancy process allocentric or external spatial information like the sighted has caused considerable debate within the literature. Due to the extreme rarity of the population, researchers have often included individuals with retinopathy of prematurity (RoP--over oxygenation at birth) within the sample. However, RoP is inextricably confounded with prematurity per se. Prematurity, without visual disability, has been associated with spatial processing difficulties. In this experiment, blindfolded sighted participants and two groups of functionally totally blind participants heard text descriptions from a survey (allocentric) or route (egocentric) perspective. One blind group lost their sight due to RoP and a second group before 24 months of age. The accuracy of participants' mental representations derived from the text descriptions was assessed via questions and maps. The RoP participants had lower scores than the sighted and early blind, who performed similarly. In other words, it was not visual impairment alone that resulted in impaired allocentric spatial performance in this task but visual impairment together with RoP. This finding may help explain the contradictions within the existing literature on the role of vision in allocentric spatial processing.

The experiences of participating in winter among youths with a physical disability compared with their typically developing peers

BACKGROUND

Having a physical disability and using a wheelchair can create difficulties in navigating the physical and built environment, especially during winter when snow and ice become problematic. Little is known about the experiences of winter among youth who use an assistive mobility device. This study aimed to understand how youth with a physical disability experience winter, compared with typically developing peers.

METHODS

A purposive sample of 25 youths (13 with a physical disability; 12 typically developing) completed a 2-week weather journal and photographs in two Canadian cities during winter. These data were used to guide semi-structured interviews with participants.

RESULTS

Youths with disabilities experienced many similar challenges in winter, such as health and safety concerns and accessibility issues, compared with typically developing youth - but to a greater extent. Youths with disabilities reported more challenges going outdoors during winter and negative psychosocial impacts, including loneliness and increased dependence, compared with peers without a disability. They also, however, described developing several adaptive strategies to cope with these challenges.

CONCLUSIONS

There is a strong need to remove physical and environmental barriers to facilitate the participation and inclusion of youth with disabilities in winter.

Efficient national surveillance for health-care-associated infections

Background

Detecting novel healthcare-associated infections (HCAI) as early as possible is an important public health priority. However, there is currently no evidence base to guide the design of efficient and reliable surveillance systems. Here we address this issue in the context of a novel pathogen spreading primarily between hospitals through the movement of patients.

Methods

Using a mathematical modelling approach we compare the current surveillance system for a HCAI that spreads primarily between hospitals due to patient movements as it is implemented in Scotland with a gold standard to determine if the current system is maximally efficient or whether it would be beneficial to alter the number and choice of hospitals in which to concentrate surveillance effort.

Results

We validated our model by demonstrating that it accurately predicts the risk of meticillin-resistant Staphylococcus aureus bacteraemia cases in Scotland.

Using the 29 (out of 182) sentinel hospitals that currently contribute most of the national surveillance effort results in an average detection time of 117 days. A reduction in detection time to 87 days is possible by optimal selection of 29 hospitals. Alternatively, the same detection time (117 days) can be achieved using just 22 optimally selected hospitals. Increasing the number of sentinel hospitals to 38 (teaching and general hospitals) reduces detection time by 43 days; however decreasing the number to seven sentinel hospitals (teaching hospitals) increases detection time substantially to 268 days.

Conclusions

Our results show that the current surveillance system as it is used in Scotland is not optimal in detecting novel pathogens when compared to a gold standard. However, efficiency gains are possible by better choice of sentinel hospitals, or by increasing the number of hospitals involved in surveillance. Similar studies could be used elsewhere to inform the design and implementation of efficient national, hospital-based surveillance systems that achieve rapid detection of novel HCAIs for minimal effort.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2172-9) contains supplementary material, which is available to authorized users.

Staphylococcus aureus and the oral cavity: an overlooked source of carriage and infection?

BACKGROUND

The role of intraoral Staphylococcus aureus in disease and cross-infection sources is controversial. We present a 10-year retrospective analysis of laboratory data reporting isolation of S aureus from oral and perioral clinical specimens.

METHODS

A review of laboratory records for specimens where S aureus was isolated were collated and analyzed from January 1998-December 2007 at the Oral Microbiology Laboratory, Glasgow Dental Hospital.

RESULTS

There were 11,312 specimens submitted to the laboratory over the study time period. S aureus was isolated from 1,986 specimens (18%). Of these, 1,782 (90%) were methicillin-sensitive S aureus (MSSA), and 204 (10%) were methicillin-resistant S aureus (MRSA). The most common specimen type from which MSSA was isolated was an oral rinse, whereas for MRSA this was a tongue swab. Most of the MRSA isolates were EMRSA-15 or EMRSA-16 lineage.

CONCLUSION

These findings suggest that S aureus continues to be a frequent isolate in the oral cavity and perioral region. The oral cavity should be considered a source of S aureus in terms of cross-infection and dissemination to other body sites. The role of S aureus in the pathogenesis of certain oral diseases should also be considered as part of a differential diagnosis.

Stimulated release of a hyperpolarizing factor (ADHF) from mesenteric artery perivascular adipose tissue: involvement of myocyte BKCa channels and adiponectin

BACKGROUND AND PURPOSE

Perivascular adipose tissue (PVAT) releases adipocyte-derived hyperpolarizing factors (ADHFs) that may partly act by opening myocyte K(+) channels. The present study in rat and mouse mesenteric arteries aimed to identify the myocyte K(+) channel activated by PVAT and to determine whether adiponectin contributed to the hyperpolarizing effects of PVAT.

EXPERIMENTAL APPROACH

Myocyte membrane potential was recorded from de-endothelialized, non-contracted rat and mouse mesenteric arteries in the presence and absence of PVAT.

KEY RESULTS

The β3 -adrenoceptor agonist, CL-316,243 (10 μM), generated PVAT-dependent, iberiotoxin-sensitive myocyte hyperpolarizations resulting from BKCa channel opening and which were partially blocked by L-NMMA (100 μM). Adiponectin (5 μg·mL(-1) ) also produced iberiotoxin-sensitive hyperpolarizations in PVAT-denuded arterioles. Activation of myocyte AMP-activated protein kinase (AMPK) using 5 μM A-769662 also induced BKCa -mediated hyperpolarizations. Dorsomorphin abolished hyperpolarizations to CL-316,243, adiponectin and A-769662. In vessels from Adipo(-/-) mice, hyperpolarizations to CL-316,243 were absent whereas those to A-769662 and adiponectin were normal. In rat vessels, adipocyte-dependent hyperpolarizations were blocked by glibenclamide and clotrimazole but those to NS1619 (33 μM) were unaltered.

CONCLUSIONS AND IMPLICATIONS

Under basal, non-contracted conditions, β3 -adrenoceptor stimulation of PVAT releases an ADHF, which is probably adiponectin. This activates AMPK to open myocyte BKCa channels indirectly and additionally liberates NO, which also contributes to the observed PVAT-dependent myocyte hyperpolarizations. Clotrimazole and glibenclamide each reversed hyperpolarizations to adiponectin and A-769662, suggesting the involvement of myocyte TRPM4 channels in the ADHF-induced myocyte electrical changes mediated via the opening of BKCa channels.

Cluster of Legionnaires’ disease cases caused by Legionella longbeachae serogroup 1, Scotland, August to September 2013

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Genome-wide single nucleotide polymorphism-based assay for high-resolution epidemiological analysis of the methicillin-resistant Staphylococcus aureus hospital clone EMRSA-15

The EMRSA-15 clone is a major cause of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infections in the UK and elsewhere but existing typing methodologies have limited capacity to discriminate closely related strains, and are often poorly reproducible between laboratories. Here, we report the design, development and validation of a genome-wide single nucleotide polymorphism (SNP) typing method and compare it to established methods for typing of EMRSA-15. In order to identify discriminatory SNPs, the genomes of 17 EMRSA-15 strains, selected to represent the breadth of genotypic and phenotypic diversity of EMRSA-15 isolates in Scotland, were determined and phylogenetic reconstruction was carried out. In addition to 17 phylogenetically informative SNPs, five binary markers were included to form the basis of an EMRSA-15 genotyping assay. The SNP-based typing assay was as discriminatory as pulsed-field gel electrophoresis, and significantly more discriminatory than staphylococcal protein A (spa) typing for typing of a representative panel of diverse EMRSA-15 strains, isolates from two EMRSA-15 hospital outbreak investigations, and a panel of bacteraemia isolates obtained in healthcare facilities in the east of Scotland during a 12-month period. The assay is a rapid, and reproducible approach for epidemiological analysis of EMRSA-15 clinical isolates in Scotland. Unlike established methods the DNA sequence-based method is ideally suited for inter-laboratory comparison of identified genotypes, and its flexibility lends itself to supplementation with additional SNPs or markers for the identification of novel S. aureus strains in other regions of the world.

Enhancing the mental representations of space used by blind pedestrians, based on an image schemata model

The configuration of mental representation of space plays a major role in successful navigational activities. Therefore, navigational assistance for pedestrians who are blind should help them to better configure their mental representation of the environment. In this paper, we propose and exploit a computational model for the mental representation of urban areas as an aid to orientation and navigation for visually impaired pedestrians. Our model uses image schemata to capture the spatial semantics and configural elements of urban space necessary for this purpose. These image schemata are schematic structures that are continually requested by individuals in their perception, bodily movement and interaction with surrounding objects. Our proposed model also incorporates a hierarchical structure to provide different levels of detail tied to appropriate spatial perspectives at each scale. We presume that such computational model will help us to develop an appropriate structure of spatial data used to assist the target population. At the end of the paper, we illustrate the utility of our configural model by developing a typical scenario for the navigation of a blind pedestrian in an urban area.