Increased brain microvascular hemoglobin concentrations in children with cerebral malaria

Brain swelling is associated with death from cerebral malaria, but it is unclear whether brain swelling is caused by cerebral edema or vascular congestion-two pathological conditions with distinct effects on tissue hemoglobin concentrations. We used near-infrared spectroscopy (NIRS) to noninvasively study cerebral microvascular hemoglobin concentrations in 46 Malawian children with cerebral malaria. Cerebral malaria was defined by the presence of the malaria parasite Plasmodium falciparum on a blood smear, a Blantyre coma score of 2 or less, and retinopathy. Children with uncomplicated malaria (n = 33) and healthy children (n = 29) were enrolled as comparators. Cerebral microvascular hemoglobin concentrations were higher among children with cerebral malaria compared with those with uncomplicated malaria [median (25th, 75th): 145.2 (95.2, 190.0) μM versus 82.9 (65.7, 105.4) μM, P = 0.008]. Cerebral microvascular hemoglobin concentrations correlated with brain swelling score determined by MRI (r = 0.37, P = 0.03). Fluctuations in cerebral microvascular hemoglobin concentrations over a 30-min time period were characterized using detrended fluctuation analysis (DFA). DFA determined self-similarity of the cerebral microvascular hemoglobin concentration signal to be lower among children with cerebral malaria compared with those with uncomplicated malaria [0.63 (0.54, 0.70) versus 0.91 (0.82, 0.94), P < 0.0001]. The lower self-similarity of the hemoglobin concentration signal in children with cerebral malaria suggested impaired regulation of cerebral blood flow. The elevated cerebral tissue hemoglobin concentration and its correlation with brain swelling suggested that excess blood volume, potentially due to vascular congestion, may contribute to brain swelling in cerebral malaria.

Effects of Climate on the Variation in Abundance of Three Tick Species in Illinois

The range of ticks in North America has been steadily increasing likely, in part, due to climate change. Along with it, there has been a rise in cases of tick-borne disease. Among those medically important tick species of particular concern are Ixodes scapularis Say (Acari: Ixodidae), Dermacentor variabilis Say (Acari: Ixodidae), and Amblyomma americanum Linneaus (Acari: Ixodidae). The aim of this study was to determine if climate factors explain existing differences in abundance of the three aforementioned tick species between two climatically different regions of Illinois (Central and Southern), and if climate variables impact each species differently. We used both zero-inflated regression approaches and Bayesian network analyses to assess relationships among environmental variables and tick abundance. Results suggested that the maximum average temperature and total precipitation are associated with differential impact on species abundance and that this difference varied by region. Results also reinforced a differential level of resistance to desiccation among these tick species. Our findings help to further define risk periods of tick exposure for the general public, and reinforce the importance of responding to each tick species differently.

Oral Lisinopril Raises Tissue Levels of ACE2, the SARS-CoV-2 Receptor, in Healthy Male and Female Mice

Angiotensin-converting enzyme 2 (ACE2) is the established cellular receptor for SARS-CoV-2. However, it is unclear whether ACE1 inhibitors (e.g., lisinopril) or angiotensin receptor blockers (e.g., losartan) alter tissue ACE2 expression. This study sought to determine whether lisinopril or losartan, as monotherapies or in combination, changes tissue levels of ACE2 in healthy male and female mice. Mice received lisinopril (10 mg/kg/day), losartan (10 mg/kg/day), or both for 21 days via drinking water. A control group received water without drug. The ACE2 protein index (ACE2 protein/total protein) was determined on the small intestine, lung, kidney, and brain. Oral lisinopril increased the ACE2 protein index across all tissues (p < 0.0001 vs. control). In contrast, the combination of lisinopril plus losartan did not increase ACE2 levels in any tissue (p = 0.89 vs. control) and even decreased tissue expression of the Ace2 gene (p < 0.001 vs. control). Tissue ACE2 remained elevated in the mice 21 days after cessation of lisinopril (p = 0.02). Plasma ACE2 did not correlate with the ACE2 protein index in any tissue. A sex difference was observed: kidney ACE2 levels were higher in male than in female mice (p < 0.0001). Oral lisinopril increases ACE2, the cellular receptor for SARS-CoV-2, in tissues that are relevant to the transmission and pathogenesis of COVID-19. Remarkably, the addition of losartan prevented lisinopril-induced increases in ACE2 across tissues. These results suggest that ACE inhibitors and angiotensin receptor blockers interact to determine tissue levels of ACE2.

A new measure to understand the role of science in US Congress: lessons learned from the Legislative Use of Research Survey (LURS)

BACKGROUND

There is growing interest in and recognition of the need to use scientific evidence to inform policymaking. However, many of the existing studies on the use of research evidence (URE) have been largely qualitative, and the majority of existing quantitative measures are underdeveloped or were tested in regional or context-dependent settings. We are unaware of any quantitative measures of URE with national policymakers in the US.

AIMS AND OBJECTIVES

Explore how to measure URE quantitatively by validating a measure of congressional staff's attitudes and behaviors regarding URE, the Legislative Use of Research Survey (LURS), and by discussing the lessons learned through administering the survey.

METHODS

A 68-item survey was administered to 80 congressional staff to measure their reported research use, value of research, interactions with researchers, general information sources, and research information sources. Confirmatory factor analyses were conducted on each of these five scales. We then trimmed the number of items, based on a combination of poor factor loadings and theoretical rationale, and ran the analyses on the trimmed subscales.

FINDINGS

We substantially improved our model fits for each scale over the original models and all items had acceptable factor loadings with our trimmed 35-item survey. We also describe the unique set of challenges and lessons learned from surveying congressional staff.

DISCUSSION AND CONCLUSIONS

This work contributes to the transdisciplinary field of URE by offering a tool for studying the mechanisms that can bridge research and policy and shedding light into best practices for measuring URE with national policymakers in the US.

Duration of skin desensitisation following palmar digital nerve blocks with lidocaine, bupivacaine, mepivacaine and prilocaine

Objective comparative evidence of the time to onset and duration of effect provided by local anaesthetic (LA) agents for perineural blocks in the horse is lacking. Clear knowledge of these properties is required to guide clinically appropriate agent selection and aid interpretation of response to diagnostic blocks for lameness examinations. An interventional study, with complete, randomised crossover design was used to compare time to onset and duration of skin desensitisation provided by four LA agents applied to palmar digital nerve blocks in 12 horses. Effect at each time point was determined using a pressure gauge to measure the mechanical nociceptive threshold (MNT) over the heel bulbs. Complete desensitisation was defined when MNT was greater than four times the pre-block baseline. Onset and duration of complete desensitisation were recorded and compared across agents using a mixed linear model. When significant (P ≤ 0.05), post-hoc paired comparisons between agents were performed against a Tukey's corrected P ≤ 0.05. Onset of complete skin desensitisation for each agent was <5 min. Duration for lidocaine (mean 25 min; 95% confidence interval [CI] 9-42) was shorter than bupivacaine (53 min; 95% CI 39-65), which was shorter than both prilocaine (102 min; 95% CI 81-123) and mepivacaine (107 min; 95% CI 92-121), which were not different. Although onset of complete skin desensitisation was not different for the LA agents tested, duration varied from 25 min to nearly 2 h. Prilocaine and mepivacaine provided the most prolonged duration of effect, both exceeding bupivacaine.

Experimental Babesia rossi infection induces hemolytic, metabolic, and viral response pathways in the canine host

Background

Babesia rossi is a leading cause of morbidity and mortality among the canine population of sub-Saharan Africa, but pathogenesis remains poorly understood. Previous studies of B. rossi infection were derived from clinical cases, in which neither the onset of infection nor the infectious inoculum was known. Here, we performed controlled B. rossi inoculations in canines and evaluated disease progression through clinical tests and whole blood transcriptomic profiling.

Results

Two subjects were administered a low inoculum (10⁴ parasites) while three received a high (10⁸ parasites). Subjects were monitored for 8 consecutive days; anti-parasite treatment with diminazene aceturate was administered on day 4. Blood was drawn prior to inoculation as well as every experimental day for assessment of clinical parameters and transcriptomic profiles. The model recapitulated natural disease manifestations including anemia, acidosis, inflammation and behavioral changes. Rate of disease onset and clinical severity were proportional to the inoculum. To analyze the temporal dynamics of the transcriptomic host response, we sequenced mRNA extracted from whole blood drawn on days 0, 1, 3, 4, 6, and 8. Differential gene expression, hierarchical clustering, and pathway enrichment analyses identified genes and pathways involved in response to hemolysis, metabolic changes, and several arms of the immune response including innate immunity, adaptive immunity, and response to viral infection.

Conclusions

This work comprehensively characterizes the clinical and transcriptomic progression of B. rossi infection in canines, thus establishing a large mammalian model of severe hemoprotozoal disease to facilitate the study of host-parasite biology and in which to test novel anti-disease therapeutics. The knowledge gained from the study of B. rossi in canines will not only improve our understanding of this emerging infectious disease threat in domestic dogs, but also provide insight into the pathobiology of human diseases caused by Babesia and Plasmodium species.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-021-07889-4.

Using informatics to engage patients

As a specialty, radiology has spent much of the last two decades implementing information systems that improve departmental efficiency and the ordering provider's access to information. While our patients have realized benefits such as improved access to care and reduced turnaround times, there has been little focus on using these information systems to improve patient engagement. In the last decade, society has shifted. Now, consumers in every industry expect to be able to use technology to help them accomplish different tasks from scheduling to communicating. Medicine, in general, has been slow to respond to the concept of the patient as a consumer. In this manuscript we describe some of the informatics efforts we have employed in our department to improve patient engagement. We present these initiatives, corresponding to each aspect of the radiology value stream, from the patient's point of view.

0343 Associations of Endogenous Hormones and Phthalate Exposure with Subjective and Objective Sleep Measures in Midlife Women

Introduction

Impaired sleep during the menopausal transition reduces quality of life and increases risk of multiple diseases. The changing hormonal milieu during midlife is associated with impaired sleep. Endocrine disrupting chemicals, such as phthalates, may also contribute to the increased prevalence of sleep disturbances in midlife women. Phthalates are known to impact the endogenous hormones associated with sleep. However, the link between phthalate exposure and sleep quality remains unexplored.

Methods

We recruited 26 midlife women (median age 50 years) through the Carle Regional Sleep Disorders Center in Urbana, Illinois. Subjective sleep was assessed through the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and self-reported frequency of sleep disturbances, insomnia, and restless sleep. Objective sleep was measured using actigraphy and manual sleep logs (7-day average). Serum levels of follicle-stimulating hormone, estradiol, progesterone, testosterone, free estradiol, and free testosterone were quantified using ELISAs from a single sample from each participant. Phthalate metabolites were quantified from urine using high performance liquid chromatography-mass spectrometry (HPLC-MS). Covariates, including depression, hot flashes, quality of life, demographics, and lifestyle factors, were measured via surveys.

Results

Preliminary unadjusted logistic regression was used to determine the association between hormone values and subjective sleep quality binomial variables, including daytime sleepiness, sleep efficiency, sleep onset latency, sleep duration, number of sleep disturbances, and frequency of sleep disturbances. Each of these subjective sleep measures is significantly associated with one or more hormones.

Conclusion

Our results are consistent with literature identifying associations between hormones and subjective sleep in midlife women. Additional analyses will determine associations between hormones and objective sleep, and phthalates with both subjective and objective sleep measures. Excitingly, our study will be among the first to investigate the association between endocrine disruption and sleep quality in this population.

Support

Carle Illinois Seed Grant Program

Irrigation fluid volume requirement for conventional arthrocentesis of the temporomandibular joint: a cadaver study

Temporomandibular joint (TMJ) arthrocentesis is considered an effective and minimally invasive procedure for certain conditions related to temporomandibular disorders. The ideal irrigation volume for arthrocentesis lavage has not yet been defined. Therefore, the aim of this study was to evaluate the efficacy of different saline solution volumes in removing methylene blue from the TMJ space of fresh human cadavers. Nineteen cadavers were selected and 1ml of 10μM methylene blue solution was injected into the upper joint space unilaterally. Conventional arthrocentesis was then conducted by infusion of 300ml of 0.9% saline solution, collecting a 1-ml sample from the drained quantity for every 25ml injected. Finally, the samples were assayed by measuring photo absorbance of the methylene blue solution. There was a statistically significant difference between the irrigation volumes regarding the removal of methylene blue solution from the joint space (P<0.001), specifically between the first 25 ml and 200 ml (P=0.014), 225 ml (P=0.001), 250 ml (P<0.001), and 275 ml (P=0.001). Based on this ex vivo study, a 25-ml perfusion volume appears to be sufficient for joint lavage in conventional arthrocentesis of the TMJ.

Ranking disease control strategies with stochastic outcomes

This paper explains how the methodologies of first and second order stochastic dominance, and expected utility using specific risk preferences, can be applied to epidemiology when choosing among control strategies that have stochastic outcomes. We provide a step-by-step guide on how epidemiologists can rank a number of control strategies based on their distribution of estimated benefits. We also explain how the expected utility model and decision maker's risk preferences can be used to select between outcomes when none stochastically dominates. To illustrate these techniques, we show the ranking of various control strategies for a dairy herd endemically infected with Mycobacterium avium subs. paratuberculosis (MAP) and mastitis, and explain how decision maker's risk preferences affect the ranking.

Thalidomide-type teratogenicity: structure-activity relationships for congeners

Unravelling the molecular basis of thalidomide embryotoxicity, which is remarkably species-specific, is challenging in view of its low toxicity in the mature animal. Employing data derived solely from proven sensitive primate species or susceptible strains of rabbit, the structure-activity relationship of over 50 compounds which are, arguably, congeners of thalidomide has been reviewed. The molecular requirement for 'thalidomide-type' teratogenicity was highly structure dependent. Both the phthalimide and glutarimide groups were essential for embryopathic activity, although minor substitutions in either or both rings could be tolerated without a loss of toxicity. An α-linkage between the two cyclic structures was essential; a β-link resulted in a complete loss of embryopathic activity. Crucially, this α-configuration provided a centre of asymmetry enabling the existence of stereoisomers. The thalidomide molecule is not a static entity and under physiological conditions it undergoes a number of intra- and inter-molecular reactions. Besides irreversible hydrolysis, its keto-enol tautomerism, base-assisted proton transfer and glutarimide ring rotation lead to rapid interconversion of the thalidomide enantiomers. These enantiomers form equilibria between themselves and also between both homochiral and heterochiral dimers. It is proposed that the more energetically favourable and stable heterochiral dimer of thalidomide is an active agent that possesses the structural features of the paired nucleotides of the double-stranded DNA. Its capacity to enter into hydrogen bonding interactions affects DNA expression in a chaotic manner without causing permanent mutations. This disruption may well be concentrated at nucleotide sites known to be involved in specific promoter regions of the genome.

Alane adsorption and dissociation on the Si(0 0 1) surface

We used DFT to study the energetics of the decomposition of alane, AlH₃, on the Si(0 0 1) surface, as the acceptor complement to PH₃. Alane forms a dative bond with the raised atoms of silicon surface dimers, via the Si atom lone pair. We calculated the energies of various structures along the pathway of successive dehydrogenation events following adsorption: AlH₂, AlH and Al, finding a gradual, significant decrease in energy. For each stage, we analyse the structure and bonding, and present simulated STM images of the lowest energy structures. Finally, we find that the energy of Al atoms incorporated into the surface, ejecting a Si atom, is comparable to Al adatoms. These findings show that Al incorporation is likely to be as precisely controlled as P incorporation, if slightly less easy to achieve.

Use of an Individual-based Model to Control Transmission Pathways of Mycobacterium avium Subsp. paratuberculosis Infection in Cattle Herds

Johne’s disease (JD) is a chronic enteric disease in cattle caused by Mycobacterium avian subsp. paratuberculosis (MAP). Eradicating JD is a difficult task due to the long incubation period of MAP, inefficient diagnostic tests, and delayed clinical signs. Effective control strategies can help farmers to reduce prevalence, but those most acceptable to farmers combine specific information about lactation performance and testing results, which existing models do not provide. This paper presents an individual-based model of MAP infection dynamics and assesses the relative performance of the applied alternative control strategies. The base dairy herd model included the daily life events of a dairy cow and reflects several current dairy management processes. We then integrated MAP infection dynamics into the model. The model adopted four different test-based control strategies based on risk-based culling decisions and three hygiene scenarios. The model tracked the source of each infection and quantified the efficacy of each control strategy in reducing the risks of different transmission routes. The results suggest that risk-based culling can reduce prevalence compared with no control, but cannot eliminate the infection. Overall, this work provides not only a valuable tool to investigate MAP transmission dynamics but also offers adaptability to model similar infectious diseases.

The effect of Mycobacterium avium ssp. paratuberculosis infection on clinical mastitis occurrence in dairy cows

Endemic diseases can be counted among the most serious sources of losses for livestock production. In dairy farms in particular, one of the most common diseases is Johne's disease, caused by Mycobacterium avium ssp. paratuberculosis (MAP). Infection with MAP causes direct costs because it affects milk production, but it has also been suspected to increase the risk of clinical mastitis (CM) among infected animals. This might contribute to further costs for farmers. We asked whether MAP infection represents a risk factor for CM and, in particular, whether CM occurrences were more common in MAP-infected animals. Our results, obtained by survival analysis, suggest that MAP-infected cows had an increased probability of experiencing CM during lactation. These results highlight the need to account for the interplay of infectious diseases and other health conditions in economic and epidemiological modeling. In this case, accounting for MAP-infected cows having an increased CM occurrence might have nonnegligible effects on the estimated benefit of MAP control.

Economic consequences of paratuberculosis control in dairy cattle: A stochastic modeling study

The cost of paratuberculosis to dairy herds, through decreased milk production, early culling, and poor reproductive performance, has been well-studied. The benefit of control programs, however, has been debated. A recent stochastic compartmental model for paratuberculosis transmission in US dairy herds was modified to predict herd net present value (NPV) over 25 years in herds of 100 and 1000 dairy cattle with endemic paratuberculosis at initial prevalence of 10% and 20%. Control programs were designed by combining 5 tests (none, fecal culture, ELISA, PCR, or calf testing), 3 test-related culling strategies (all test-positive, high-positive, or repeated positive), 2 test frequencies (annual and biannual), 3 hygiene levels (standard, moderate, or improved), and 2 cessation decisions (testing ceased after 5 negative whole-herd tests or testing continued). Stochastic dominance was determined for each herd scenario; no control program was fully dominant for maximizing herd NPV in any scenario. Use of the ELISA test was generally preferred in all scenarios, but no paratuberculosis control was highly preferred for the small herd with 10% initial prevalence and was frequently preferred in other herd scenarios. Based on their effect on paratuberculosis alone, hygiene improvements were not found to be as cost-effective as test-and-cull strategies in most circumstances. Global sensitivity analysis found that economic parameters, such as the price of milk, had more influence on NPV than control program-related parameters. We conclude that paratuberculosis control can be cost effective, and multiple control programs can be applied for equivalent economic results.

DOSE AND GAMMA-RAY SPECTRA FROM NEUTRON-INDUCED RADIOACTIVITY IN MEDICAL LINEAR ACCELERATORS FOLLOWING HIGH-ENERGY TOTAL BODY IRRADIATION

Production of radioisotopes in medical linear accelerators (linacs) is of concern when the beam energy exceeds the threshold for the photonuclear interaction. Staff and patients may receive a radiation dose as a result of the induced radioactivity in the linac. Gamma-ray spectroscopy was used to identify the isotopes produced following the delivery of 18 MV photon beams from a Varian 21EX and an Elekta Synergy. The prominent radioisotopes produced include ¹⁸⁷W, ⁶³Zn, ⁵⁶Mn, ²⁴Na and ²⁸Al in both linac models. The dose rate was measured at the beam exit window (12.6 µSv in the first 10 min) following 18 MV total body irradiation (TBI) beams. For a throughput of 24 TBI patients per year, staff members are estimated to receive an annual dose of up to 750 μSv at the patient location. This can be further reduced to 65 μSv by closing the jaws before re-entering the treatment bunker.

Prolactin and Impotence in Diabetes Mellitus

A study was undertaken to determine whether impotence in some diabetic patients might be due to a coincidental prolactinoma and therefore be potentially treatable. Of 83 consecutive men attending a diabetic clinic, three were found to have persistent mild to moderate hyperprolactinaemia. None of the three was impotent or taking any drug known to be associated with elevated serum prolactin, and anterior pituitary responses and pituitary fossa tomograms did not reveal any abnormality. The mean serum prolactin concentration of the 37 insulin-treated men was not significantly different from that of the 46 men on diet with or without anti-diabetic tablets, nor was there any significant difference between the mean serum prolactin concentrations of the 19 impotent men and of the 64 non-impotent men.

The views of parents who experience intergenerational poverty on parenting and play: a qualitative analysis

BACKGROUND

There is minimal literature on how parents experiencing intergenerational poverty view their role as parents and the value they place on children's play. The objective of this study was to examine how these parents view their parenting role and their beliefs about children's play.

METHODS

Thirteen mothers of preschool-aged children who experienced intergenerational poverty were recruited to the study. Semi-structured interviews were conducted and were analysed using interpretive phenomenological analysis.

RESULTS

Parents described their role as guiding their children to become 'good' people, to teach them skills and provide a routine within the home. There were two disconnections in the data including the view that whilst parenting was hard and lonely, it was also a private matter and participants preferred not to seek support. A second disconnection was in terms of their beliefs about play. Parents believed that whilst play was valuable to their child's development, it was not their role to play with children. However, if parents did play with their child, they noticed positive changes in their child's behaviour.

CONCLUSION

The views of parents who experienced intergenerational poverty were similar to other reported findings in parenting studies. However, the current sample differed on not seeking help for support as well as not seeing their role as playing with their children, even though occasions of joining their child in play were associated with a positive change in their relationship with their child. This has implications for communicating about parenting issues with parents who have experienced intergenerational poverty.

Anatomy of screw dislocations in nanoporous SAPO-18 as revealed by atomic force microscopy

The complex crystal-growth mechanism of the industrially important nanoporous catalyst SAPO-18 is investigated by atomic force microscopy.

Angiogenic responses are enhanced in mechanically and microscopically characterized, microbial transglutaminase crosslinked collagen matrices with increased stiffness

During angiogenesis, endothelial cells (ECs) use both soluble and insoluble cues to expand the existing vascular network to meet the changing trophic needs of the tissue. Fundamental to this expansion are physical interactions between ECs and extracellular matrix (ECM) that influence sprout migration, lumen formation and stabilization. These physical interactions suggest that ECM mechanical properties may influence sprouting ECs and, therefore, angiogenic responses. In a three-dimensional angiogenic model in which a monolayer of ECs is induced to invade an underlying collagen matrix, angiogenic responses were measured as a function of collagen matrix stiffness by inducing collagen crosslinking with microbial transglutaminase (mTG). By biaxial mechanical testing, stiffer collagen matrices were measured with both mTG treatment and incubation time. Using two-photon excited fluorescence (TPF) and second harmonic generation (SHG), it was shown that collagen TPF intensity increased with mTG treatment, and the TPF/SHG ratio correlated with biaxially tested mechanical stiffness. SHG and OCM were further used to show that other ECM physical properties such as porosity and pore size did not change with mTG treatment, thus verifying that matrix stiffness was tuned independently of matrix density. The results showed that stiffer matrices promote more angiogenic sprouts that invade deeper. No differences in lumen size were observed between control and mTG stiffened matrices, but greater remodeling was revealed in stiffer gels using SHG and OCM. The results of this study show that angiogenic responses are influenced by stiffness and suggest that ECM properties may be useful in regenerative medicine applications to engineer angiogenesis.

A relationship between mechanically-induced changes in serum cartilage oligomeric matrix protein (COMP) and changes in cartilage thickness after 5 years

OBJECTIVE

To evaluate the hypothesis that a mechanical stimulus (30-min walk) will produce a change in serum concentrations of cartilage oligomeric matrix protein (COMP) that is associated with cartilage thickness changes on magnetic resonance imaging (MRI).

METHODS

Serum COMP concentrations were measured by enzyme-linked immunosorbent assay in 17 patients (11 females, age: 59.0±9.2 years) with medial compartment knee osteoarthritis (OA) at study entry immediately before, immediately after, 3.5 h, and 5.5 h after a 30-min walking activity. Cartilage thickness changes in the medial femur and medial tibia were determined from MR images taken at study entry and at 5-year follow-up. Relationships between changes in cartilage thickness and COMP levels, with post-activity concentrations expressed as a percentage of pre-activity levels, were assessed by the calculation of Pearson correlation coefficients and by multiple linear regression analysis, with adjustments for age, sex, and body mass index (BMI).

RESULTS

Changes in COMP levels 3.5 h and 5.5 h post-activity were correlated with changes in cartilage thickness in the medial femur and tibia at the 5-year follow-up. The results were strengthened after analyses were adjusted for age, sex, and BMI. Neither baseline pre-activity COMP levels nor changes in COMP levels immediately post-activity were correlated with cartilage thickness changes.

CONCLUSIONS

The results of this study support the hypothesis that a change in COMP concentration induced by a mechanical stimulus is associated with cartilage thinning at 5 years. Mechanically-induced changes in mechano-sensitive biomarkers should be further explored in the context of stimulus-response models to improve the ability to assess OA progression.

Chemotherapy dose-intensity and survival for childhood medulloblastoma

AIM

To determine the relationship between prescribed dose-intensity of chemotherapy and survival in childhood medulloblastoma.

MATERIALS AND METHODS

A total of 55 trials from 1970-2009 were identified, 30 were eligible for analysis, with individual treatment regimes with 5-year (or more) outcome figures. Relationships of outcome to dose-intensity were analysed using weighted regression.

RESULTS

Overall, 2,434 patients were identified, 1,010 were classified as 'standard'- and 671 as 'high'-risk patients, with 5-year overall survivals (OS) of 67.2% (95% Confidence Interval=60.5%-73.6%) and 47.6% (95% Confidence Interval=39.5%-55.7%), respectively. A protective effect for chemotherapy versus craniospinal radiotherapy alone (5-year OS of 58.2% versus 51.6%) was found. Individually, vincristine, cisplatin, lomustine (CCNU) and cyclophosphamide appear to confer the most beneficial effect, particularly for high-risk patients. Positive relationships between OS and dose-intensity were found, except for lomustine, with cyclophosphamide offering the greatest protection.

CONCLUSION

Consideration of chemotherapy dose-intensity may further optimise treatment, particularly in the context of risk stratification.

Economic analysis of Mycobacterium avium subspecies paratuberculosis vaccines in dairy herds

Johne's disease, or paratuberculosis, is a chronic infectious enteric disease of ruminants, caused by infection with Mycobacterium avium ssp. paratuberculosis (MAP). Given the absence of a fail-safe method of prevention or a cure, Johne's disease can inflict significant economic loss on the US dairy industry, with an estimated annual cost of over $200 million. Currently available MAP control strategies include management measures to improve hygiene, culling MAP serologic- or fecal-positive adult cows, and vaccination. Although the 2 first control strategies have been reported to be effective in reducing the incidence of MAP infection, the changes in herd management needed to conduct these control strategies require significant effort on the part of the dairy producer. On the other hand, vaccination is relatively simple to apply and requires minor changes in herd management. Despite these advantages, only 5% of US dairy operations use vaccination to control MAP. This low level of adoption of this technology is due to limited information on its cost-effectiveness and efficacy and some important inherent drawbacks associated with current MAP vaccines. This study investigates the epidemiological effect and economic values of MAP vaccines in various stages of development. We create scenarios for the potential epidemiological effects of MAP vaccines, and then estimate economically justifiable monetary values at which vaccines become economically beneficial to dairy producers such that a net present value (NPV) of a farm's net cash flow can be higher than the NPV of a farm using no control or alternative nonvaccine controls. Any vaccination with either low or high efficacy considered in this study yielded a higher NPV compared with a no MAP control. Moreover, high-efficacy vaccines generated an even higher NPV compared with alternative controls, making vaccination economically attractive. Two high-efficacy vaccines were particularly effective in MAP control and NPV maximization. One was a high-efficacy vaccine that reduced susceptibility to MAP infection. The other was a high-efficacy vaccine that had multiple efficacies on the dynamics of MAP infection and disease progress. Only one high-efficacy vaccine, in which the vaccine is targeted at reducing MAP shedding and the number of clinical cases, was not economically beneficial to dairy producers compared with an alternative nonvaccine control, when herds were highly infected with MAP.

Robust calculation of effective atomic numbers: the Auto-Z(eff) software

PURPOSE

The most appropriate method of evaluating the effective atomic number necessitates consideration of energy-dependent behavior. Previously, this required quite laborious calculation, which is why many scientists revert to over-simplistic power-law methods. The purpose of this work is to develop user-friendly software for the robust, energy-dependent computation of effective atomic numbers relevant within the context of medical physics, superseding the commonly employed simplistic power law approaches.

METHOD

Visual Basic was used to develop a GUI allowing the straightforward calculation of effective atomic numbers. Photon interaction cross section matrices are constructed for energies spanning 10 keV to 10 GeV and elements Z = 1-100. Coefficients for composite media are constructed via linear additivity of the fractional constituents and contrasted against the precalculated matrices at each energy, thereby associating an effective atomic number through interpolation of adjacent cross section data. Uncertainties are of the order of 1-2%.

RESULTS

Auto-Z(eff) allows rapid (∼0.6 s) calculation of effective atomic numbers for a range of predefined or user-specified media, allowing estimation of radiological properties and comparison of different media (for instance assessment of water equivalence). The accuracy of Auto-Z(eff) has been validated against numerous published theoretical and experimental predictions, demonstrating good agreement. The results also show that commonly employed power-law approaches are inaccurate, even in their intended regime of applicability (i.e., photoelectric regime). Furthermore, comparing the effective atomic numbers of composite materials using power-law approaches even in a relative fashion is shown to be inappropriate.

CONCLUSION

Auto-Z(eff) facilitates easy computation of effective atomic numbers as a function of energy, as well as average and spectral-weighted means. The results are significantly more accurate than normal power-law predictions. The software is freely available to interested readers, who are encouraged to contact the authors.

17 novel polymorphic microsatellite markers for the giant water bug, Abedus herberti (Belostomatidae)

The giant water bug (Abedus herberti) is a large flightless insect that is a keystone predator in aridland aquatic habitats. Extended droughts, possibly due to climate change and groundwater pumping, are causing once-perennial aquatic habitats to dry, resulting in serious conservation concern for some populations. A. herberti also exhibits exclusive male parental care, which has made it a model organism for studying mating systems evolution. Here we describe 17 novel polymorphic microsatellite loci developed for A. herberti. Number of alleles per locus ranged from 2 to 15, and average observed and expected heterozygosities were 0.579 and 0.697, respectively. These loci can successfully resolve both population genetic structure among sites separated by 3-100 km (F_ST = 0.08-0.21, P < 0.0001), and divergent mating strategies within local populations, making them highly useful for conservation genetics studies of this vulnerable species.

A systematic investigation of confirmed autoimmune loci in early-onset psoriasis reveals an association with IL2/IL21

BACKGROUND

Many autoimmune diseases share common susceptibility loci suggesting similar underlying cellular mechanisms involved in disease expression.

OBJECTIVES

The purpose of this investigation was to study 21 genetic variants in 14 genes that are confirmed autoimmune loci in a cohort of patients with early-onset psoriasis.

METHODS

Patients with early-onset psoriasis (n = 750) and controls (n = 3531) were genotyped using the Sequenom(®) MassArray™ iPLEX Gold platform.

RESULTS

We found strong evidence of association with two variants in the IL2/IL21 (rs6822844, genotypic P = 3·3 × 10(-4) ; rs2069778, genotypic P = 7·86 × 10(-4)) region.

CONCLUSIONS

The findings, although requiring replication, suggest that IL2/IL21 may play a key role in the pathogenesis of psoriasis as well as in other diverse autoimmune diseases.

Effects of intermittent hydrostatic pressure and BMP-2 on osteoarthritic human chondrocyte metabolism in vitro

PURPOSE

This study examined effects of intermittent hydrostatic pressure (IHP) and a chondrogenic growth factor, bone morphogenetic protein-2 (BMP-2), on anabolic, catabolic, and other metabolic markers in human osteoarthritic (OA) chondrocytes in vitro.

METHODS

Articular chondrocytes, isolated from femoral OA cartilage and maintained in high-density monolayer culture, were examined for effects of BMP-2 and IHP on gene expression of matrix-associated proteins (aggrecan, type II collagen, and SOX9) and catabolic matrix metalloproteinases (MMP-2 and MMP-3) and culture medium levels of the metabolic markers MMP-2, nitric oxide (NO), and glycosaminoglycan (GAG). The results were analyzed using a mixed linear regression model to investigate the effects of load and growth factor concentration.

RESULTS

IHP and BMP-2 modulated OA chondrocyte metabolism in accordance with growth factor concentration independently, without evidence of synergism or antagonism. Each type of stimulus acted independently on anabolic matrix gene expression. Type II collagen and SOX9 gene expression were stimulated by both IHP and BMP-2 whereas aggrecan was increased only by BMP-2. IHP exhibited a trend to decrease MMP-2 gene expression as a catabolic marker whereas BMP-2 did not. NO production was increased by addition of BMP-2 and IHP exhibited a trend for increased levels. GAG production was increased by BMP-2.

CONCLUSIONS

This study confirmed the hypothesis that human OA chondrocytes respond to a specific type of mechanical load, IHP, through enhanced articular cartilage macromolecule gene expression and that IHP, in combination with a chondrogenic growth factor BMP-2, additively enhanced matrix gene expression without interactive effects.

Differential recruitment of nuclear receptor coregulators in ligand-dependent transcriptional repression by estrogen receptor-α

Estrogen receptors (ERs) are normally expressed in breast tissues and mediate hormonal functions during development and in female reproductive physiology. In the majority of breast cancers, ERs are involved in regulating tumor cell proliferation and serve as prognostic markers and therapeutic targets in the management of hormone-dependent tumors. At the molecular level, ERs function as ligand-dependent transcription factors and activate target-gene expression following hormone stimulation. Recent transcriptomic and whole-genome-binding studies suggest, however, that ligand-activated ERs can also repress the expression of a significant subset of target genes. To characterize the molecular mechanisms of transcriptional repression by ERs, we examined recruitment of nuclear receptor coregulators, histone modifications and RNA polymerase II docking at ER-binding sites and cis-regulatory regions adjacent to repressed target genes. Moreover, we utilized gene expression data from patient samples to determine potential roles of repressed target genes in breast cancer biology. Results from these studies indicate that nuclear receptor corepressor recruitment is a key feature of ligand-dependent transcriptional repression by Ers, and some repressed target genes are associated with disease progression and response to endocrine therapy. These findings provide preliminary insights into a novel aspect of the molecular mechanisms of ER functions and their potential roles in hormonal carcinogenesis and breast cancer biology.

Effect of Johne's disease status on reproduction and culling in dairy cattle

Among the costs attributed to Mycobacterium avium ssp. paratuberculosis (MAP) infection in dairy cattle, the effects on reproduction and culling are the least documented. To estimate the cost of MAP infections and Johne's disease in a dairy herd, the rates of calving and culling were calculated for cows in each stage of MAP infection relative to uninfected cows. Data from 6 commercial dairy herds, consisting of 2,818 cows with 2,754 calvings and 1,483 cullings, were used for analysis. Every cow in each study herd was tested regularly for MAP, and herds were followed for between 4 and 7 yr. An ordinal categorical variable for Johne's disease status [test-negative, low-positive (low-shedding or ELISA-positive only), or high-shedding] was defined as a time-dependent variable for all cows with at least 1 positive test result or 2 negative test results. A Cox regression model, stratified on herd and controlling for the time-dependent infection variable, was used to analyze time to culling. Nonshedding animals were significantly less likely to be culled in comparison with animals in the low-shedding or ELISA-positive category, and high-shedding animals had nonsignificantly higher culling rates than low-shedding or ELISA-positive animals. Time to calving was analyzed using a proportional rates model, an analog to the Andersen-Gill regression model suitable for recurrent event data, stratifying on herd and weighted to adjust for the dependent censoring caused by the culling effects described above. High-shedding animals had lower calving rates in comparison with low-shedding or ELISA-positive animals, which tended to have higher calving rates than test-negative animals.

Nanopore formation by low-energy focused electron beam machining

The fabrication of nanopores in thin silicon nitride and aluminum oxide membranes by water vapor assisted, low-energy (0.2-20 kV) electron beam machining using a scanning electron microscope (SEM) is described. Using this technique, pores with diameters ranging in size from < 5 to 20 nm are easily formed. The nanopores are characterized by SEM, transmission electron microscopy (TEM) and atomic force microscopy (AFM). The mechanism of etching is briefly discussed.

Repeated copulation and sperm precedence: paternity assurance for a male brooding water bug

Male giant water bugs (Abedus herberti Hidalgo) brood eggs attached to their backs by their mates. Brooders risk being "cuckolded" because females store sperm from previous matings. Males always copulate with females prior to receiving their eggs and mate repeatedly during oviposition. Experiments with a genetic marker reveal almost complete sperm precedence for the last male to mate with a female. The male's behavior therefore assures his paternity of the eggs he broods.

Peru coastal currents during el nino: 1976 and 1982

Year-long measurements of subsurface current and temperature on Peru's continental shelf included the onset of El Niño in 1976 and 1982. The Peru Coastal Undercurrent more than doubled in speed and advected anomalously warm water poleward. El Niño began in different seasons in 1976 and 1982, but the current and temperature responses were very similar. Acceleration of poleward flow at 10 degrees S occurred several days after sea level rose at the Galápagos Islands in October 1982, suggesting the onset of El Niño propagated as a Kelvin wave.

Biliary excretion of foreign compounds. Benzene and its derivatives in the rat

1. The extent of the excretion in the bile of the rat of benzene and 21 of its simple derivatives was studied. 2. Some 16 compounds of molecular weight less than 200, and including neutral molecules (benzene and toluene), aromatic acids, aromatic amines and phenols, were injected in solution intraperitoneally into biliary-cannulated rats. Metabolites in the bile were identified and estimated. The extent of biliary excretion of these compounds was low, i.e. 0-10% of the dose in 24hr., and most appeared in the bile mainly as conjugates. 3. The biliary excretion of six conjugates of molecular weight less than 300, including three glycine conjugates, one sulphate conjugate, one glucuronic acid conjugate and two acetyl derivatives, was low (less than 3% of the dose). 4. It is concluded that simple benzene derivatives of molecular weight less than about 300 are poorly excreted in rat bile.

Biliary excretion of foreign compounds. Biphenyl, stilboestrol and phenolphthalein in the rat: molecular weight, polarity and metabolism as factors in biliary excretion

1. The extent of biliary excretion of biphenyl, tetralin, stilboestrol and phenolphthalein was studied in the rat. 2. Biphenyl and its 4-hydroxy and 4,4'-dihydroxy derivatives are extensively excreted in the bile as glucuronides in amounts increasing in order of molecular weight. 3. Stilboestrol and its glucuronide are excreted almost quantitatively in the bile mainly as the monoglucuronide, as are also phenolphthalein and its glucuronide. 4. Tetralin is excreted to the extent of about 13% of the dose, mainly as ac-tetralyl glucuronides. 5. The results and those of Abou-El-Makarem, Millburn, Smith & Williams (1967) are discussed and it is concluded that the extent of biliary excretion of foreign compounds in rats depends on their molecular weight and their possessing a strongly polar anionic group. There appears to be a minimum value of this molecular weight below which little biliary excretion (i.e. not more than 5-10% of the dose) occurs. There is some latitude in the choice of this molecular weight, which is about 325+/-50. The necessary molecular weight and polar group can be acquired by metabolism. Above this minimum value biliary excretion increases with molecular weight. It is suggested that the mechanism of the biliary excretion of foreign compounds may be similar to that of conjugated bile acids, which are highly polar and whose molecular weights exceed 400.

Reduction of sulfur compounds in the sediments of a eutrophic lake basin

Concentrations of various sulfur compounds (SO(4), H(2)S, S, acid-volatile sulfide, and total sulfur) were determined in the profundal sediments and overlying water column of a shallow eutrophic lake. Low concentrations of sulfate relative to those of acid-volatile sulfide and total sulfur and a decrease in total sulfur with sediment depth implied that the contribution of dissimilatory sulfur reduction to H(2)S production was relatively minor. Addition of 1.0 mM Na(2)SO(4) to upper sediments in laboratory experiments resulted in the production of H(2)S with no apparent lag. Kinetic experiments with S demonstrated an apparent K(m) of 0.068 mmol of SO(4) reduced per liter of sediment per day, whereas tracer experiments with S indicated an average turnover time of the sediment sulfate pool of 1.5 h. Total sulfate reduction in a sediment depth profile to 15 cm was 15.3 mmol of sulfate reduced per m per day, which corresponds to a mineralization of 30% of the particulate organic matter entering the sediment. Reduction of S occurred at a slower rate. These results demonstrated that high rates of sulfate reduction occur in these sediments despite low concentrations of oxidized inorganic compounds and that this reduction can be important in the anaerobic mineralization of organic carbon.

Anaerobic oxalate degradation: widespread natural occurrence in aquatic sediments

Significant concentrations of oxalate (dissolved plus particulate) were present in sediments taken from a diversity of aquatic environments, ranging from 0.1 to 0.7 mmol/liter of sediment. These included pelagic and littoral sediments from two freshwater lakes (Searsville Lake, Calif., and Lake Tahoe, Calif.), a hypersaline, meromictic, alkaline lake (Big Soda Lake, Nev.), and a South San Francisco Bay mud flat and salt marsh. The oxalate concentration of several plant species which are potential detrital inputs to these aquatic sediments ranged from 0.1 to 5.0% (wt/wt). In experiments with litter bags, the oxalate content of Myriophyllum sp. samples buried in freshwater littoral sediments decreased to 7% of the original value in 175 days. This suggests that plant detritus is a potential source of the oxalate within these sediments. [C]oxalic acid was anaerobically degraded to CO(2) in all sediment types tested, with higher rates evident in littoral sediments than in the pelagic sediments of the lakes studied. The turnover time of the added [C]oxalate was less than 1 day in Searsville Lake littoral sediments. The total sediment oxalate concentration did not vary significantly between littoral and pelagic sediments and therefore did not appear to be controlling the rate of oxalate degradation. However, depth profiles of [C]oxalate mineralization and dissolved oxalate concentration were closely correlated in freshwater littoral sediments; both were greatest in the surface sediments (0 to 5 cm) and decreased with depth. The dissolved oxalate concentration (9.1 mumol/liter of sediment) was only 3% of the total extractable oxalate (277 mumol/liter of sediment) at the sediment surface. These results suggest that anaerobic oxalate degradation is a widespread phenomenon in aquatic sediments and may be limited by the dissolved oxalate concentration within these sediments.

Biliary excretion in foreign compounds. Sulphonamide drugs in the rat

1. The extent of biliary excretion in the rat of 15 sulphonamide compounds was studied. 2. Most of the sulphonamides studied, with molecular weights from 172 (sulphanilamide) to 352 (N(4)-acetylsulphadimethoxine) are poorly excreted in the bile (0-4% of the dose), except sulphapyridine, sulphamethoxypyridazine and sulphadimethoxine. The last three are partly metabolized to glucuronides, whose molecular weights and polarities are such as to allow them to be excreted in the bile in appreciable amounts. 3. Succinylsulphathiazole and phthalylsulphathiazole are polar and have molecular weights (355 and 403) of an appropriate order, and are excreted unchanged in the bile in appreciable amounts. 4. Sulphadimethoxine N(1)-glucuronide (mol.wt. 487) is extensively excreted in the bile unchanged. 5. The results are examined in the light of the hypotheses put forward in the preceding paper (Millburn, Smith & Williams, 1967).

Biliary excretion in foreign compounds. Species difference in biliary excretion

1. The biliary excretion of injected [(14)C]aniline, [(14)C]benzoic acid, 4-amino-hippuric acid and 4-acetamidohippuric acid in six or eight species of animal (rat, dog, hen, cat, rabbit, guinea pig, rhesus monkey and sheep) was studied. 2. These compounds, with molecular weights in the range 93-236, are poorly excreted in the bile in all the species examined and, in effect, there is little significant species difference in the extent of their biliary excretion. 3. Compounds of higher molecular weight (355-495) were also studied, namely succinylsulphathiazole, [(14)C]stilboestrol glucuronide, sulphadimethoxine N(1)-glucuronide and phenolphthalein glucuronide. 4. With these compounds a clear species difference in the extent of biliary excretion was found, the rat, dog and hen being good excretors, the rabbit, guinea pig and monkey poor excretors, and the cat and sheep taking an intermediary position. 5. There was a general trend for biliary excretion to be higher in all species when the compounds were of higher molecular weight. 6. These results are discussed in their relation to species differences in drug metabolism.

Autotrophic, hydrogen-oxidizing, denitrifying bacteria in groundwater, potential agents for bioremediation of nitrate contamination

Addition of hydrogen or formate significantly enhanced the rate of consumption of nitrate in slurried core samples obtained from an active zone of denitrification in a nitrate-contaminated sand and gravel aquifer (Cape Cod, Mass.). Hydrogen uptake by the core material was immediate and rapid, with an apparent K(m) of 0.45 to 0.60 muM and a V(max) of 18.7 nmol cm h at 30 degrees C. Nine strains of hydrogen-oxidizing denitrifying bacteria were subsequently isolated from the aquifer. Eight of the strains grew autotrophically on hydrogen with either oxygen or nitrate as the electron acceptor. One strain grew mixotrophically. All of the isolates were capable of heterotrophic growth, but none were similar to Paracoccus denitrificans, a well-characterized hydrogen-oxidizing denitrifier. The kinetics for hydrogen uptake during denitrification were determined for each isolate with substrate depletion progress curves; the K(m)s ranged from 0.30 to 3.32 muM, with V(max)s of 1.85 to 13.29 fmol cell h. Because these organisms appear to be common constituents of the in situ population of the aquifer, produce innocuous end products, and could be manipulated to sequentially consume oxygen and then nitrate when both were present, these results suggest that these organisms may have significant potential for in situ bioremediation of nitrate contamination in groundwater.

Electron donors utilized by sulfate-reducing bacteria in eutrophic lake sediments

Mineralization rates of C-labeled substrates were determined in the presence and absence of Na(2)MoO(4), an inhibitor of sulfate reduction, in the profundal sediments of a shallow eutrophic lake. Sulfate reduction was inhibited by Na(2)MoO(4) at all concentrations tested (0.2 to 200 mM), whereas methane production was inhibited at Na(2)MoO(4) concentrations greater than 20 mM. Initial mineralization rates of glucose were unaffected by Na(2)MoO(4); however, Na(2)MoO(4) decreased the mineralization rates of lactate (58%), propionate (52%), an amino acid mixture (85%), and acetate (14%). These decreases in the rates of mineralization were attributed to inhibition of sulfate reduction. Hydrogen stimulated the reduction of SO(4) 2.5- to 2.8-fold, demonstrating potential hydrogen oxidation by sulfate-reducing bacteria. These results indicate that sulfate reducers utilize an array of substrates as electron donors and are of potential significance to the in situ mineralization of lactate, propionate, and free amino acids in these sediments.

Biliary excretion of [C]succinylsulphathiazole in the rat and rabbit

1. After intravenous injection about 30% of the dose (20mg./kg.) of succinylsulphathiazole is excreted unchanged in the bile in 3hr. by the rat, whereas only about 1% is excreted by the rabbit. When the renal pedicles are ligated the biliary excretion of succinylsulphathiazole in the rat increases to about 80% of the dose, but in the rabbit under these conditions the biliary excretion is only 2% of the dose. 2. In the rat, the sulphonamide readily enters the liver and biliary excretion occurs against a concentration gradient from liver to bile; further, the excretory process can be saturated, and can be depressed by the simultaneous administration of phenolphthalein glucuronide or bile salts. 3. In the rabbit, these conditions have not been found; succinylsulphathiazole does not readily enter the liver from the plasma, there is no transfer of the drug from the liver cells to the bile against a concentration gradient, and no saturation or depression of the biliary excretion of succinylsulphathiazole is found. 4. It is suggested that two factors responsible, at least partly, for the low biliary excretion of succinylsulphathiazole in the rabbit are the poor entry of the sulphonamide into the liver in this species and a deficiency of the concentrative mechanism for its excretion in the bile.

Electron beam stimulated oxidation of carbon

The patterning of carbon nanostructures by electron beam stimulated oxidation is described. Sputter deposited carbon thin films and carbon nanotubes are locally oxidized in a scanning electron microscope using injected water vapor. The resulting structures are examined with scanning electron microscopy and transmission electron microscopy. The electrical resistance obtained postprocessing is comparable to the as-deposited values. Linewidths are demonstrated down to 20 nm along with sub-2 nm nanowire fabrication in sputtered carbon films. A carbon nanowire is fabricated using this process and electrically characterized.