The Norwich Osteoarthritis of the Ankle MRI Score (NOAMS): a reliability study.

AIM: To define and test the inter- and intra-rater reliability of a grading system for staging osteoarthritis (OA) of the ankle with magnetic resonance imaging (MRI) (Norwich Osteoarthritis of the Ankle MRI Score, NOAMS). MATERIALS AND METHODS: The MRI features to be included in the score were defined by a multidisciplinary expert panel through a Delphi process. An anonymised randomised dataset of 50 MRI studies was created from patients with concurrent plain radiographs to include 10 ankles of each of the Kellgren-Lawrence grades 0 to 4. Two experienced musculoskeletal radiologists and two trainees scored each ankle MRI twice independently and blinded to the plain radiographs. RESULTS: The inter-rater kappa coefficient of agreement for cartilage disease was 0.88 (95% confidence interval [CI]: 0.85, 0.91) for experienced raters and 0.71 (95% CI: 0.67, 0.76) for trainees. Inter-rater agreement for subchondral bone marrow oedema and cysts varied from 0.73 to 0.82 for experienced raters and from 0.63 to 0.75 for trainees with lowest 95% CI of 0.48 and 0.63. When bone marrow lesions were combined into a total joint score the level of agreement increased to between 0.88 and 0.97 with lowest 95% CI of 0.86. Combining cartilage zone scores did not increase the reliability coefficients. CONCLUSION: An expert panel considered that cartilage degradation and subchondral bone marrow lesions were the most important features for staging the severity of ankle OA on MRI. Experienced observers can grade the severity of ankle OA on MRI with a clinically useful high degree of reproducibility.

Youth screen use in the ABCD® study.

Adolescent screen usage is ubiquitous and influences development and behavior. Longitudinal screen usage data coupled with psychometrically valid constructs of problematic behaviors can provide insights into these relationships. We describe methods by which the screen usage questionnaire was developed in the Adolescent Brain Cognitive Development (ABCD) Study, demonstrate longitudinal changes in screen usage via child report and describe data harmonization baseline-year 2. We further include psychometric analyses of adapted social media and video game addiction scales completed by youth. Nearly 12,000 children ages 9-10 years at baseline and their parents were included in the analyses. The social media addiction questionnaire (SMAQ) showed similar factor structure and item loadings across sex and race/ethnicities, but that item intercepts varied across both sex and race/ethnicity. The videogame addiction questionnaire (VGAQ) demonstrated the same configural, metric and scalar invariance across racial and ethnic groups, however differed across sex. Video gaming and online social activity increased over ages 9/10-11/12 (p's < 0.001). Compared with boys, girls engaged in greater social media use (p < .001) and demonstrated higher ratings on the SMAQ (p < .001). Compared with girls, boys played more video games (p < .001) and demonstrated higher ratings on the VGAQ (p < .001). Time spent playing video games increased more steeply for boys than girls from age 9/10-11/12 years (p < .001). Black youth demonstrated significantly higher SMAQ and VGAQ scores compared to all other racial/ethnic groups. These data show the importance of considering different screen modalities beyond total screen use and point towards clear demographic differences in use patterns. With these comprehensive data, ABCD is poised to address critical questions about screen usage changes across adolescence.

Efficacy and Nontarget Effects of Net Exclusion Enclosures on Apple Pest Management.

Management of direct apple pests, such as codling moth, continues to be problematic despite the widespread implementation of behavioral and chemical controls. Apple growers have increased their use of netting to protect fruit from environmental injury, with some structures enclosing the entire orchard. These enclosures represent a new pest management tactic through physical exclusion. We conducted a two-year trial to examine the effects of full exclusion netting on pests and natural enemies of apples. Insect densities and damage in trees under fully enclosed (net) cages were compared with conventionally (insecticide only) treated and untreated plots. Caged plots had 18.1- and 11.4-fold less codling moth damage than the check, and 4.9- and 4.2-fold less damage than the insecticide-only plots in 2016 and 2017, respectively. However, densities of woolly apple aphid and its parasitoid Aphelinus mali (Haldeman) (Hymenoptera: Aphelinidae) were significantly greater in the caged plots. Densities of earwigs, a typically flightless generalist predator, were not different among treatments, while adults of more mobile flying generalist predators, lacewings and syrphids, were significantly lower in cages compared with uncaged plots. These results demonstrate that although biological control may be partially disrupted, net enclosures have significant potential as a holistic apple management technique.

Investigation of the effects of fine structure on the nanomechanical properties of pectin.

Pectin is an important structural polysaccharide found in the cell walls of all land plants. While in detail its composition and its organization in muro are complex, it is predominantly a copolymer of galacturonic acid and its methylesterified counterpart. Previous single-molecule stretching studies carried out on a sparsely methylesterified pectin sample indicated the importance of force-induced conformational transitions of the pyranose ring during extension, and the possible biological role of such transitions was discussed. More heavily methylesterified samples are better biomimetic models of the polymeric components as found in the plant cell wall, in particular being less restricted by the shackles of the significant intermolecular interactions expected to constrain the behavior of bare galacturonic acid sequences. Density functional theory calculations revealed that upon extending galacturonic acid monomers, whether methylesterified or not, the initial ((4)C1) chair structure is transformed to a ((3)S5) skew boat and that subsequently upon further elongation, via an intermediate inverted skew boat ((5)S3), the inverted chair ((1)C4) is reached. Experimentally, the force-extension curve of highly methylesterified pectin was found to be solvent dependent in the same manner as the un-esterified sample, indicating that minimal changes in the strength of interring hydrogen bonding result from such a substitution, and finally, as only subtle changes in the force-extension behavior of pectin resulted from changes in the degree of methylesterification, previous speculations about the role of force-induced transformations in vivo are supported.

Model for stretching elastic biopolymers which exhibit conformational transformations.

We derive an expression that represents the physical behavior of a polysaccharide molecule as it is stretched from the entropic region, through one or more ring conformational transformations, into the Hookean regime. The model adapts existing models in order to accommodate one or more force-induced conformational transformations of the glycan rings and is based on the concept of equilibrium between the clicked (longer conformers) and unclicked states. This equilibrium is determined by the Gibbs energy difference between these two states which is perturbed in favor of the clicked states by the force applied to the molecule. The derived expression is used to generate force-extension curves for model polymers and can illustrate the effect of the Gibbs energy for each transformation on the shape of these curves. It is also used to fit the force-extension curves of polysaccharides to obtain the Gibbs energy differences between the conformers. Good agreement was found between this model and experimental data on carboxymethylamylose, dextran, alginate, and pectin.

Accumulation of cadmium and lead in the gills of Mytilus edulis: X-ray microanalysis and chemical analysis.

The accumulation of Cd and Pb in the gills of the lamellibranch mollusc Mytilus edulis has been studied by electron microscopy, X-ray microanalysis, atomic absorption spectroscopy and radionuclide monitoring. The patterns of accumulation of the two elements differ markedly as do the sites of deposition whithin the gills. Lead is found extracellularly as crystalline deposits in the basal lamina which forms the capillary walls of the gill lamellae. The Pb is found associated with Ca in equiatomic ratios and occurs either as a mixed or complex carbonate. Cadmium is always associated with S and frequently with P in membrane bound vesicles within the cells of the gill epithelium and in the amoebocytes. The S is probably attributable to the presence of cysteine residues in a metal binding protein which can be extracted from the gills. Analysis of the metal binding protein shows that it binds Ag, Cd, Cu, Fe, Hg, Sn and Zn. Its amino acid composition is similar to that reported for eels and limpets but has a lower cysteine content than mammalian metal binding protein.

X-ray micronalysis of copper and sulphur-containing granules in the fat body cells of homopteran insects.

Regions of the fat body of larvae of Chaetophyes compacta and Pectinariophyes sp. (Machaerotidae, Homoptera) which are closely associated with mycetomes have been analysed by electron probe X-ray microanalysis. It is shown that cells in these regions contain electron probe X-ray microanalysis. It is shown that cells in these regions contain electron dense granules which are rich in copper and sulphur. These two elements occur in the atomic ratio of 3:2 respectively. It is conjectured that copper may be bound to a sulphur containing metallothionein and that the granules represent either the end products of copper detoxification or serve as copper stores for synthesis of enzymes and macromolecules by the mycetomal symbionts.

Changes in surface features during desiccation of the anhydrobiotic plant parasitic nematode Ditylenchus dipsaci.

The anhydrobiotic nematode Ditylenchus dipsaci is a fast-dehydration strategist, itself generating the slow rate of water loss necessary for survival. A permeability slump occurs during the initial phases of desiccation. This may be produced by changes in the nematode's cuticle. Two scanning electron microscopic techniques were used to follow changes in surface structures during desiccation. Freeze substitution and critical-point drying produced artifacts that obscured changes produced by the desiccation of the nematode. Low-temperature field emission scanning electron microscopy (FESEM) was successful in following changes that reflected those observed by light microscopy (LM). Significant changes in diameter, the lateral alae, and the cuticular annulations were demonstrated using this technique. Two types of annulations were observed: the major annulations, which extended to meet the margins of the lateral alae, and the minor annulations, which did not. With desiccation the prominence of the annulations increased, their spacing decreased, and the minor annulations extended closer to the margins of the lateral alae. These observations are consistent with the permeability slump resulting from a decrease in the width of the annulation groove and an increase in its depth. However, this requires confirmation using techniques that can follow annulation changes in individual nematodes.

Low temperature FESEM of the calcifying interface of a scleractinian coral.

The ultrastructural nature of the calcifying interface in the scleractinian coral Galaxea fascicularis has been investigated using high-resolution, low temperature field emission scanning electron microscopy (FESEM). This technique permitted structural analyses of soft tissue and skeleton in G. fascicularis in a frozen-hydrated state, without the need for chemical fixation or decalcification. Structural comparisons are made between frozen-hydrated polyps and polyps that have undergone conventional fixation and decalcification. Vesicles expelled by the calicoblastic ectodermal cells into sub-skeletal spaces and previously suggested to play a role in calcification were commonly observed in fixed samples but were distinctly absent in frozen-hydrated preparations. We propose that these vesicles are fixation artefacts. Two distinct types of vesicles (380 and 70 nm in diameter, respectively), were predominant throughout the calicoblastic ectodermal cells of frozen-hydrated preparations, but these were never seen to be entering, or to be contained within, sub-skeletal spaces, nor did they contain any crystalline material. In frozen-hydrated preparations, membranous sheets were seen to surround and isolate portions of aboral mesogloea and to form junctional complexes with calicoblastic cells. The calicoblastic ectoderm was closely associated with the underlying skeleton, with sub-skeletal spaces significantly smaller (P<0.0001) in frozen-hydrated polyps compared to fixed polyps. A network of organic filaments (26 nm in diameter) extended from the apical membranes of calicoblastic cells into these small sub-skeletal cavities. A thin sheath was also frequently observed adjacent to the apical membrane of calicoblastic cells.

The ultrastructure of the sensory plaque organs of the antennae the chinese lantern fly, Pyrops Candelaria L., (Homoptera, Fulgoridae).

The plaque organs of Pyrops consist of elaborately folded, finely perforated cuticular areas, each associated with numerous bipolar sensory cells organised in groups. The proximal, mitochondrial region of each dendrite narrows to reveal a ciliary ultrastructure. The ciliary fibrils pass into a highly vesiculated region and beyond this are succeeded by a dense array of neurotubules. Peripherally the dendrites proliferate numerous fine branches from which finer filaments extend into the cuticular pores. The plaques are considered to be complex olfactory organs evolved from groups of sensilla basiconica.

Pathogenesis of infectious bronchitis nephritis. 1. Morphometric analysis of kidney proximal tubular epithelium in chickens.

The ultrastructure of the proximal tubular epithelial cells in chicken kidneys was examined throughout the course of an experimental infection with infectious bronchitis virus. A quantitative assessment of the structural changes in the cells was related to these in normal cells. Significant alterations were detected in the membrane structures and in the mitochondria. There was a reduction in surface area of the microvillus membrane, the basolateral membrane and the apical tubular membrane. There were alterations in the shape of mitochondrial profiles and a decrease in the volume density of mitochondria. Vesicular structures, which are a possible site of viral release, were observed in the lateral surface of cells. These changes in the functional components of the cells indicate impaired transport of ions and water. The results demonstrate the value of stereological methods for the study of viral-host cell interactions in the pathogenesis of viral disease.

Thermal compensation of metabolism in the temperate coral, Plesiastrea versipora (Lamarck, 1816).

Plesiastrea versipora is a hermatypic coral with a distribution that extends to the southern limit for hermatypic corals. The normal annual temperature range for this coral in Port Phillip Bay (Victoria) (approximately 10-21 degrees C) is well below the physiological optimum for the majority of hermatypic corals (25-29 degrees C). The rate of photosynthesis and respiration in Plesiastrea generally increased with temperature before levelling out at the higher temperatures, with Q(10) data suggesting that both photosynthesis and respiration in Plesiastrea acclimate to changing temperatures. Respiration showed a similar trend to photosynthesis, with respect to temperature, but with a slightly lower rate of increase. Photosynthetic rate in Plesiastrea is comparable with that of reef corals despite lower temperatures and irradiance. When expressed as a function of chlorophyll a content photosynthesis approached perfect temperature compensation with prolonged exposure to various temperatures. Temperature-dependent changes with chlorophyll content may be responsible for temperature related changes in photosynthetic rate. This may be a mechanism for stabilising the symbiotic relationship over a wide temperature range. Autotrophic ability, estimated from photosynthesis/respiration (P/R) ratios, was greatest at higher temperatures and was only slightly less than that of reef corals. At low temperatures Plesiastrea may be dependent on heterotrophic feeding.

X-ray microanalytical investigation of the response of chicken proximal tubule cells to infection with avian infectious bronchitis virus.

The technique for X-ray microanalysis of frozen-hydrated bulk specimens was used to determine the intracellular and luminal fluid electrolyte concentrations in the proximal tubules of kidneys from chickens infected with infectious bronchitis virus. Eight days post-infection with this virus there were significant changes in the electrolyte composition when compared with values from normal control chickens. The intracellular sodium decreased from 43 to 36 mmol/l, the chloride fell from 41 to 31 mmol/l and the potassium went from 125 to 115 mmol/l. Sodium counts in the luminal fluid rose from .73 to 1.03 cps. These disturbances in electrolyte composition are consistent with alterations in sodium reabsorption in the proximal tubule due to decreased transport of sodium into the cells across the microvillus membrane. It appears that the Na-K-ATPase pump is unaffected. The results demonstrate the value of X-ray microanalysis methods for the study of electrolyte transport in pathologically affected cells and provide further information for the definition of viral-host cell interactions in the pathogenesis of viral disease. As a check on methodology two normal rat kidneys were analysed in the same way. Intracellular sodium and potassium concentrations were 22 and 138 mmol/l respectively.

X-ray microanalysis of renal proximal tubules in cadmium-treated rats.

Cadmium chloride was administered to Sprague-Dawley rats in drinking water at 100 ppm for 39 weeks. The mean cadmium concentration in kidneys from 5 rats at the end of this period was 102 +/- 17 micrograms g-1 wet weight (mean +/- SE) compared with 0.22 +/- 0.15 microgram g-1 wet weight in a similar group of control rats. Right kidneys were rapidly frozen in propane and small pieces of cortex were prepared for X-ray microanalysis by freeze-substitution in ether/acrolein for 21 days. Analysis of freeze-substituted sections showed that Cd concentrations rose to 3.9 mmol kg-1 of resin embedded tissue (approximately wet weight) in cytoplasm and 6.5 mmol kg-1 in nuclei. At the same time S concentrations rose by 31 percent in nuclei and 23 percent in the cytoplasm. Cd was also present in lysosomes. Cytoplasmic and nuclear ionic (Na, K, Cl, Ca, Mg) concentrations did not change in spite of a considerable decrease in microvillus membrane surface area. The concentration of P also did not change suggesting that nucleoside phosphate levels remained stable. The distribution of Cd and S supports current concepts of cadmium toxicity. Although total kidney Cd was at the critical concentration and extensive damage to microvilli had occurred, there appeared to be no effect on ionic permeability and cell electrolyte balance and, by inference, NaCl reabsorption.

Morphometric analysis of renal proximal tubules in cadmium-treated rats.

The morphological changes in renal proximal tubules of Sprague Dawley rats given acute or chronic exposure to cadmium were analysed. Cadmium chloride was administered either by five subcutaneous injections of cadmium at 2 mg kg-1 body weight or in drinking water at 100 micrograms ml-1 for 39 weeks. The mean cadmium concentration in the kidneys of these rats was 45 and 102 micrograms g-1 wet weight respectively. The rats were anaesthetized and the kidneys were fixed by perfusion and processed for electron microscopy. Proximal tubule profiles were larger in the acute exposure rats. The brush border in both groups of treated rats was shorter and there were focal areas of loss of microvilli. The surface density of microvillus membrane per unit cell volume was reduced by 25% and 19% for chronic and acute dosed rats respectively. There were few significant changes in organelles detected by morphometric analysis of the entire kidney tissue, however there was a reduction in volume density of lysosomes following chronic exposure and individual necrotic cells and distorted nuclei were observed. The morphological changes observed in chronic and acute dosed rats were consistent with a primary site of toxic insult on the apical plasma membrane. There appeared to be no evidence for change in fluid and electrolyte homeostasis in the epithelium. The results suggest that the cadmium may produce a selective deficit of transport mechanisms for macromolecules.