Cartilage T1ρ and T2 relaxation times: longitudinal reproducibility and variations using different coils, MR systems and sites.

OBJECTIVE: To evaluate the longitudinal reproducibility and variations of cartilage T1ρ and T2 measurements using different coils, MR systems and sites. METHODS: Single-Site study: Phantom data were collected monthly for up to 29 months on four GE 3T MR systems. Data from phantoms and human subjects were collected on two MR systems using the same model of coil; and were collected on one MR system using two models of coils. Multi-site study: Three participating sites used the same model of MR systems and coils, and identical imaging protocols. Phantom data were collected monthly. Human subjects were scanned and rescanned on the same day at each site. Two traveling human subjects were scanned at all three sites. RESULTS: Single-Site Study: The phantom longitudinal RMS-CVs ranged from 1.8% to 2.7% for T1ρ and 1.8-2.8% for T2. Significant differences were found in T1ρ and T2 values using different MR systems and coils. Multi-Site Study: The phantom longitudinal RMS-CVs ranged from 1.3% to 2.6% for T1ρ and 1.2-2.7% for T2. Across three sites (n = 16), the in vivo scan-rescan RMS-CV was 3.1% and 4.0% for T1ρ and T2, respectively. Phantom T1ρ and T2 values were significantly different between three sites but highly correlated (R > 0.99). No significant difference was found in T1ρ and T2 values of traveling controls, with cross-site RMS-CV as 4.9% and 4.4% for T1ρ and T2, respectively. CONCLUSION: With careful quality control and cross-calibration, quantitative MRI can be readily applied in multi-site studies and clinical trials for evaluating cartilage degeneration.

Evaluation of a field deployable, high-throughput RT-LAMP device as an early warning system for COVID-19 through SARS-CoV-2 measurements in wastewater.

Quantification of SARS-CoV-2 RNA copies in wastewater can be used to estimate COVID-19 prevalence in communities. While such results are important for mitigating disease spread, SARS-CoV-2 measurements require sophisticated equipment and trained personnel, for which a centralized laboratory is necessary. This significantly impacts the time to result, defeating its purpose as an early warning detection tool. The objective of this study was to evaluate a field portable device (called MINI) for detecting SARS-CoV-2 viral loads in wastewater using real-time reverse transcriptase loop-mediated isothermal amplification (real-time RT-LAMP). The device was tested using wastewater samples collected from buildings (with 430 to 1430 inhabitants) that had known COVID-19-positive cases. Results show comparable performance of RT-LAMP against reverse transcriptase polymerase chain reaction (RT-qPCR) when detecting SARS-CoV-2 copies in wastewater. Both RT-LAMP and RT-qPCR detected SARS-CoV-2 in wastewater from buildings with at least three positive individuals within a 6-day time frame prior to diagnosis. The large 96-well throughput provided by MINI provided scalability to multi-building detection. The portability of the MINI device enabled decentralized on-site detection, significantly reducing the time to result. The overall findings support the use of RT-LAMP within the MINI configuration as an early detection system for COVID-19 infection using wastewater collected at the building scale.

Manipulation of mtDNA heteroplasmy in all striated muscles of newborn mice by AAV9-mediated delivery of a mitochondria-targeted restriction endonuclease.

Mitochondrial diseases are frequently caused by heteroplasmic mitochondrial DNA (mtDNA) mutations. As these mutations express themselves only at high relative ratios, any approach able to manipulate mtDNA heteroplasmy can potentially be curative. In this study, we developed a system to manipulate mtDNA heteroplasmy in all skeletal muscles from neonate mice. We selected muscle because it is one of the most clinically affected tissues in mitochondrial disorders. A mitochondria-targeted restriction endonuclease (mito-ApaLI) expressed from AAV9 particles was delivered either by intraperitoneal or intravenous injection in neonate mice harboring two mtDNA haplotypes, only one of which was susceptible to ApaLI digestion. A single injection was able to elicit a predictable and marked change in mtDNA heteroplasmy in all striated muscles analyzed, including heart. No health problems or reduction in mtDNA levels were observed in treated mice, suggesting that this approach could have clinical applications for mitochondrial myopathies.

It's not what you hear, it's the way you think about it: appraisals as determinants of affect and behaviour in voice hearers.

BACKGROUND: Previous studies have suggested that beliefs about voices mediate the relationship between actual voice experience and behavioural and affective response. METHOD: We investigated beliefs about voice power (omnipotence), voice intent (malevolence/benevolence) and emotional and behavioural response (resistance/engagement) using the Beliefs About Voices Questionnaire - Revised (BAVQ-R) in 46 voice hearers. Distress was assessed using a wide range of measures: voice-related distress, depression, anxiety, self-esteem and suicidal ideation. Voice topography was assessed using measures of voice severity, frequency and intensity. We predicted that beliefs about voices would show a stronger association with distress than voice topography. RESULTS: Omnipotence had the strongest associations with all measures of distress included in the study whereas malevolence was related to resistance, and benevolence to engagement. As predicted, voice severity, frequency and intensity were not related to distress once beliefs were accounted for. CONCLUSIONS: These results concur with previous findings that beliefs about voice power are key determinants of distress in voice hearers, and should be targeted specifically in psychological interventions.

Plant genotype and nitrogen loading influence seagrass productivity, biochemistry, and plant-herbivore interactions.

Genetic variation within and among key species can have significant ecological consequences at the population, community, and ecosystem levels. In order to understand ecological properties of systems based on habitat-forming clonal plants, it is crucial to clarify which traits vary among plant genotypes and how they influence ecological processes, and to assess their relative contribution to ecosystem functioning in comparison to other factors. Here we used a mesocosm experiment to examine the relative influence of genotypic identity and extreme levels of nitrogen loading on traits that affect ecological processes (at the population, community, and ecosystem levels) for Zostera marina, a widespread marine angiosperm that forms monospecific meadows throughout coastal areas in the Northern Hemisphere. We found effects of both genotype and nitrogen addition on many plant characteristics (e.g., aboveground and belowground biomass), and these were generally strong and similar in magnitude, whereas interactive effects were rare. Genotypes also strongly differed in susceptibility to herbivorous isopods, with isopod preference among genotypes generally matching their performance in terms of growth and survival. Chemical rather than structural differences among genotypes drove these differences in seagrass palatability. Nitrogen addition uniformly decreased plant palatability but did not greatly alter the relative preferences of herbivores among genotypes, indicating that genotype effects are strong. Our results highlight that differences in key traits among genotypes of habitat-forming species can have important consequences for the communities and ecosystems that depend on them and that such effects are not overwhelmed by known environmental stressors.

What are the most effective intervention techniques for changing physical activity self-efficacy and physical activity behaviour--and are they the same?

There is convincing evidence that targeting self-efficacy is an effective means of increasing physical activity. However, evidence concerning which are the most effective techniques for changing self-efficacy and thereby physical activity is lacking. The present review aims to estimate the association between specific intervention techniques used in physical activity interventions and change obtained in both self-efficacy and physical activity behaviour. A systematic search yielded 27 physical activity intervention studies for 'healthy' adults that reported self-efficacy and physical activity data. A small, yet significant (P < 0.01) effect of the interventions was found on change in self-efficacy and physical activity (d = 0.16 and 0.21, respectively). When a technique was associated with a change in effect sizes for self-efficacy, it also tended to be associated with a change (r(s) = 0.690, P < 0.001) in effect size for physical activity. Moderator analyses found that 'action planning', 'provide instruction' and 'reinforcing effort towards behaviour' were associated with significantly higher levels of both self-efficacy and physical activity. 'Relapse prevention' and 'setting graded tasks' were associated with significantly lower self-efficacy and physical activity levels. This meta-analysis provides evidence for which psychological techniques are most effective for changing self-efficacy and physical activity.

Organ-specific shifts in mtDNA heteroplasmy following systemic delivery of a mitochondria-targeted restriction endonuclease.

Most pathogenic mtDNA mutations are heteroplasmic and there is a clear correlation between high levels of mutated mtDNA in a tissue and pathology. We have found that in vivo double-strand breaks (DSBs) in mtDNA lead to digestion of cleaved mtDNA and replication of residual mtDNA. Therefore, if DSB could be targeted to mutations in mtDNA, mutant genomes could be eliminated and the wild-type mtDNA would repopulate the cells. This can be achieved by using mitochondria-targeted restriction endonucleases as a means to degrade specific mtDNA haplotypes in heteroplasmic cells or tissues. In this work, we investigated the potential of systemic delivery of mitochondria-targeted restriction endonucleases to reduce the proportion of mutant mtDNA in specific tissues. Using the asymptomatic NZB/BALB mtDNA heteroplasmic mouse as a model, we found that a mitochondria-targeted ApaLI (that cleaves BALB mtDNA at a single site and does not cleave NZB mtDNA) increased the proportion of NZB mtDNA in target tissues. This was observed in heart, using a cardiotropic adeno-associated virus type-6 (AAV6) and in liver, using the hepatotropic adenovirus type-5 (Ad5). No mtDNA depletion or loss of cytochrome c oxidase activity was observed in any of these tissues. These results show the potential of systemic delivery of viral vectors to specific organs for the therapeutic application of mitochondria-targeted restriction enzymes in mtDNA disorders.

Automated analysis of postoperative behaviour: assessment of HomeCageScan as a novel method to rapidly identify pain and analgesic effects in mice.

This study evaluated whether the automated behaviour recognition software 'HomeCageScan' (HCS) could detect behaviour changes and any positive analgesic effects in two mouse strains undergoing vasectomy (C3H/HeNCrl and C57BL/6). Another objective was to test the effectiveness of HCS in differentiating between the effects of each treatment relative to conventional manual analysis. Each control (unoperated) group consisted of four mice of each strain. They were either untreated mice, mice given meloxicam alone (10 mg/kg) or mice given either saline or meloxicam (10 mg/kg) 30 min prior to isoflurane anaesthesia. The vasectomized mice received either saline or meloxicam at 5, 10 or 20 mg/kg, again, 30 min prior to isoflurane anaesthesia. Filming began one hour following surgery. Each mouse was filmed for 6 min for the manual analysis and then for a further 20 min for analysis with HCS. In a time-matched test, HCS and the manual analysis produced activity data that generated identical conclusions regarding treatment effects and strain differences. Both HCS and the manual analysis found the C57BL/6 controls were overall more active, but not following vasectomy, when both types of analysis detected markedly reduced activity. Low-dose meloxicam (5 mg/kg) had a positive effect on postoperative mobility in the C3H/HeNCrl mice; however, increasing the dose rate progressively reduced this. These effects were also detected with the manual analysis. Overall, HCS provided a sufficiently accurate and rapid method of analysing mouse behaviour encouraging more prolonged assessments in the future. This capability and the possibility of training the software to recognize a greater range of behaviours, including pain-specific indicators, should be of considerable value for assessing postoperative behaviour in both mice and rats. This would allow analgesic requirements to be investigated in a greater range of rodent models than is currently feasible with conventional analysis methods.

Microplastic accumulation and biomagnification in a coastal marine reserve situated in a sparsely populated area.

Toxic chemicals within and adsorbed to microplastics (0.05-5 mm) have the potential to biomagnify in food webs. However, microplastic concentrations in highly productive, coastal habitats are not well understood. Therefore, we quantified the presence of microplastics in a benthic community and surrounding environment of a remote marine reserve on the open coast of California, USA. Concentrations of microplastic particles in seawater were 36.59 plastics/L and in sediments were 0.227 ±â€¯0.135 plastics/g. Densities of microplastics on the surfaces of two morphologically distinct species of macroalgae were 2.34 ±â€¯2.19 plastics/g (Pelvetiopsis limitata) and 8.65 ±â€¯6.44 plastics/g (Endocladia muricata). Densities were highest in the herbivorous snail, Tegula funebralis, at 9.91 ±â€¯6.31 plastics/g, potentially due to bioaccumulation. This study highlights the need for further investigations of the prevalence and potential harm of microplastics in benthic communities at remote locations as well as human population centers.

Insulin-like growth factor 1 (IGF-1) and its receptor mRNA levels in breast cancer and adjacent non-neoplastic tissue.

UNLABELLED: Previous studies investigating the insulin-like growth factor 1 receptor (IGF-1R) expression in breast cancer tissue and adjacent non-neoplastic breast tissue (ANCT) have produced conflicting results. The IGF-1 and IGF-1R expression in pairs of breast cancer tissue and ANCT were investigated using RT-PCR and immunohistochemistry. The results of both methods were compared. MATERIALS AND METHODS: IGF-1 and IGF-1R mRNA from 31 specimen pairs were estimated using RT-PCR. Immunohistochemistry for IGF-1R was carried out on 20 specimen pairs and the strength of staining was scored. RESULTS: The mean relative IGF-1 mRNA level was lower in the cancerous tissue (mean 0.450 +/- 0.206) than in the ANCT (mean 0.632 +/- 0.384) (paired t-test, p = 0.001). There was no measurable difference in relative IGF-1R mRNA levels in the cancerous tissue (mean 0.146 +/- 0.08) and the ANCT (mean 0.14608 +/- 0.108) (paired t-test, p = 0.807). Using immunohistochemistry, there was no statistical difference (paired t-test, p = 0.910) in IGF-1R staining scores between cancer (mean 1.93) and ANCT (mean 1.90). The comparison between the two methodologies showed no correlation (Pearson's Correlation Coefficient = -0.393). DISCUSSION: It can be concluded that IGF-1 expression is lower in cancerous tissue, thus supporting a paracrine relationship between cancerous tissue and ANCT, which may be useful in the prevention, diagnosis and treatment of breast cancer. There was no difference in the expression of the IGF-1 receptor in both types of tissue, as proven by RT-PCR and immunohistochemistty. Conflicting results in previous studies may be due to the different methods used to measure IGF-1R expression.

Effects of sulindac and indomethacin on renal prostaglandin synthesis.

We compared the effects of sulindac and indomethacin, the effects of two nonsteroidal anti-inflammatory drugs, on renal prostaglandin synthesis and renal function. Sulindac, 200 mg twice daily, indomethacin, 25 mg four times a day, or placebo were taken by 15 normal female subjects (five in each of three treatment groups). Indomethacin decreased renal excretion of prostaglandins PGE2, PGF2 alpha, and 6-keto-PGF1 alpha, but sulindac and placebo had no effect on renal prostaglandin excretion. Concomitant with the reduction of renal prostaglandin synthesis in the indomethacin group, sodium and chloride excretion decreased; sulindac and placebo had no discernible effects on urine electrolytes. Extrarenal cyclooxygenase activity, as assessed by platelet thromboxane beta 2 release, was inhibited by both sulindac and indomethacin. Plasma renin activity and plasma aldosterone levels fell in all groups as a result of positive sodium balance, but the decrements of aldosterone were greater after indomethacin and sulindac. None of the treatments altered glomerular filtration rate or renal plasma flow in these normal women. We conclude that in normal women renal prostaglandin synthesis and prostaglandin-dependent tubular functions such as Na and Cl reabsorption are relatively unaffected by doses of sulindac (200 mg twice daily) that inhibit nonrenal cyclooxygenase. This may reflect the capacity of oxidative enzymes in the kidney to convert the active sulfide metabolite of sulindac to the inactive prodrug sulindac sulfoxide.

The effect of cataract severity and morphology on the reliability of the Lens Opacities Classification System II (LOCS II).

Data collected from 3646 eyes in the Italian-American Natural History Study of Age-Related Cataract were used to investigate whether the reliability of the Lens Opacities Classification System II (LOCS II) by the severity of the opacity that is being graded or is influenced by the presence and severity of coexisting opacities. Reliability was assessed by comparing the slit-lamp gradings of two clinical examiners (346 eyes) and the gradings performed at the slit lamp with gradings of photographs (3646 eyes). The severity of cortical and nuclear opacities did not affect the reproducibility of slit-lamp gradings, but clinical grading of posterior subcapsular opacities became more reliable as the severity of the posterior subcapsular opacities increased. More advanced coexisting opacities decreased the agreement in the slit-lamp diagnosis of nuclear, but not cortical or posterior subcapsular, opacities. Comparisons of clinical and photographic gradings showed very good to excellent agreement for nuclear and cortical opacities, regardless of the severity of the specific opacity or the severity of the coexisting opacities. Agreement in diagnosing posterior subcapsular opacities was decreased in eyes with milder posterior subcapsular opacities and in eyes with more severe coexisting nuclear and/or cortical opacities. The effect of the severity of the opacity being graded and the severity of coexisting opacities on the reliability of the LOCS II must be considered in studies that use the system to classify and grade cataracts.

Loiasis in an American naturalist.

In March 1981, a 32-year-old male naturalist involved with collecting mammals for study was found to have an unexpected eosinophilia. Serum parasitic screening done at the Centers for Disease Control showed filarial titer by indirect hemagglutination of 1:1,024 and of 1:40 by bentonite flocculation. His travel history disclosed 3 months spent in Cameroon in 1978. He also gave a history of intermittent arm swelling for at least a year. Peripheral blood, collected repeatedly at mid-day and midnight and tested for microfilariae by the Knott technique, was negative. He was begun empirically on diethylcarbamazine, and on day 11 of treatment he removed a worm, identified as a male Loa loa, from his leg. He completed treatment without difficulty and has done well.

Tension transduction device for functional evaluation of the rat peroneal nerve.

Current techniques for evaluating animal model nerve regeneration lack accurate, sensitive and reproducible methods to determine neuromuscular function. We have developed a tension transduction apparatus which measures the magnitude of ankle dorsiflexion produced by normal rats during bipolar stimulation of the surgically exposed peroneal nerve. Three groups of animals were used to evaluate the consistency and overall reliability of this apparatus. Within the first group of 4 animals, we determined variability in a single testing period of 8 successive stimulations. The mean normalized standard deviation of dorsiflexion tension produced was 2.9% of the mean. In the second group, comparison of right and left dorsiflexion tension in 8 animals showed a difference of less than 2% (right: 134.2 g; left: 131.6 g), demonstrating that one lower limb can be used as a control for the contralateral limb. In the third group, 12 animals were tested on two separate occasions, 2 months apart, tension production increased 10% (from 122 to 134 g) and corresponded with an average weight increase, per animal, of 100 g (30%) during the 2-month rest period. Despite the increase in weight and strength, the initial procedure had a negative effect upon the maximum tension produced compared to a previously unoperated leg (prior operation: 134 g; no prior operation: 144 g). The reproducibility of data obtainable with this new device allows for its incorporation in future studies, as well as the correlation of such functional data with other current methods of studying nerve regeneration.

Neuromuscular evaluation using rat gait analysis.

We have developed a rat gait analysis model to evaluate if ankle angle and other associated gait parameters could consistently define normal peroneal nerve and anterior tibialis muscle function. The second part of the study was designed to determine if such a model would be useful to measure recovery of function after a peroneal nerve crush injury (NCI). A clear plexiglas tunnel was designed for high-speed frame videotaping and subsequent computergraphic gait measurement and analysis. Normal gait patterns for ankle angle, back height, step and stride lengths and the stance and swing times were determined in 8 rats. Data analysis demonstrated no significant left/right differences for any of the variables (ANOVA) with the exception of step length. Subsequently, 12 rats with a peroneal NCI were evaluated. All gait parameters evaluated from the injured side were significantly different from the uninjured side after injury except stride length. Ankle angle was the most sensitive outcome variable. Weekly gait analysis provided objective measurements as the ankle angle gradually returned to normal within 3 weeks. The rat gait model is a sensitive and reproducible method for non-invasive evaluation of neuromuscular function during nerve recovery after a peroneal crush injury.

The activity of rifabutin against Mycobacterium leprae in armadillos.

The activity of rifabutin (LM 427) against Mycobacterium leprae was evaluated in armadillos inoculated earlier with human-derived M. leprae. Rifabutin was administered daily at a dose of 6 mg/kg body weight/day. The effect of rifabutin on M. leprae harvested from armadillos was determined by measuring the intracellular levels of ATP (an indicator of metabolic activity) of M. leprae and also their ability to multiply in the mouse footpads and in vitro in DH medium. Within 2 weeks of initiating the treatment, ATP levels declined to 21% of the original (pre-treatment level) and these M. leprae failed to multiply in the footpads of mice as well as in the in vitro culture system. This suggests that rifabutin was able to kill all M. leprae within 2 weeks. After 8 weeks the treatment was terminated and results showed that M. leprae from the treated armadillos remained non-viable in the mouse footpad system as well as in the in vitro system, indicating bactericidal action of rifabutin. The results suggest that rifabutin can be a substitute for rifampin in the leprosy multi-drug therapy regimen.

Generalization of therapeutic changes in agoraphobia: the role of perceived self-efficacy.

Investigated the extent and mechanisms of therapeutic generalization across distinct areas of agoraphobic dysfunction. Twenty-seven severe agoraphobics were each given performance-based treatment for some phobic areas while leaving their other phobias untreated. Behavioral tests revealed that (a) the treated phobias improved significantly more than the untreated (transfer) phobias, (b) the transfer phobias improved significantly more than control phobias, and (c) the transfer benefits were highly variable within and between subjects. Analyses of possible cognitive mechanisms revealed that perceived self-efficacy accurately predicted treatment and transfer effects even when alternative factors such as previous behavior, anticipated anxiety, anticipated panic, perceived danger, and subjective anxiety were held constant. In contrast, these alternative factors lost most or all predictive value when self-efficacy was held constant. Agoraphobia thus appears to be neither a unitary entity nor a mere collection of independent phobias, but a complexly patterned problem governed largely by self-perceptions of coping efficacy.

Thoughts of agoraphobic people during scary tasks.

The authors examined the occurrence of theoretically derived patterns of thinking in 74 agoraphobic participants as they drove alone or tolerated an enclosed place. During the increasingly scary tasks in a behavioral test hierarchy, participants responded to a periodic beep by stating aloud what they were thinking at that moment, yielding more than 1,800 tape-recorded statements. Content analyses revealed that participants were mainly preoccupied with their current anxiety (expressed in 29% of the statements) and with their self-efficacy (15%). Despite participants' mounting feelings of anxiety, fewer than 1% of their statements expressed a thought of danger or an anticipation of future anxiety or panic. The rarity of danger thoughts poses an explanatory challenge for all cognitive theories of phobia and especially for the perceived danger theory of A. T. Beck (1976) and A. T. Beck, G. Emery, and R. L. Greenberg (1985).

Prior schedule exposure reduces the acquisition of schedule-induced polydipsia.

Two groups of rats were given different initial histories before exposing them to daily, 2-hr fixed-interval 1-min (FI 1-min) food-pellet sessions with water freely available. For the initial-history phase (approximately 17 weeks), a Schedule-History Group had no water available during FI 1-min sessions, while a Home-Cage-History Group was maintained at the same body weight (80% of free feeding) in home cages. When water then became available for both groups during FI 1-min sessions, the Schedule-History Group was retarded in their rate of acquisition and final level of schedule-induced polydipsia relative to the Home-Cage-History Group. Substitution of 5% ethanol solution for session water in the final phase produced a like intake level for both groups typical for these inducing conditions. It was concluded that the probability of drinking water in a session situation is reduced by a lengthy history of water unavailability, thereby attenuating the acquisition rate and final level of schedule-induced water overdrinking.