A study of the diagnostic accuracy and reliability of the Scoliometer and Adam's forward bend test

STUDY DESIGN: Study of the diagnostic accuracy and interexaminer reliability of scoliosis diagnostic tests. OBJECTIVES: To estimate the sensitivity, specificity, and predictive value of the Scoliometer (National Scoliosis Foundation, Watertown, MA) and Adam's forward bend test in diagnosing scoliosis, and to determine the interexaminer reliability of the Scoliometer and Adam's forward bend test. SUMMARY OF BACKGROUND DATA: Exposure to diagnostic radiation in patients with adolescent idiopathic scoliosis may result in a small but significant increase in cancer rates. The full-spine radiographic examination remains the standard procedure for the assessment of scoliosis. There is a need for a valid and reliable noinvasive test to assess scoliosis. METHODS: Two examiners independently assessed 105 patients presenting to a scoliosis clinic for trunk asymmetry with Adam's forward bend test and axial trunk rotation with the Scoliometer. The Cobb method served as the gold standard. RESULTS: The interexaminer agreement for the Scoliometer is excellent in the thoracic spine and substantial in the lumbar spine. The interexaminer measurement error shows poor precision for thoracic and lumbar Scoliometer measurements. The interexaminer agreement for Adam's forward bend test is substantial in the thoracic spine and poor in the lumbar spine. Adam's forward bend test is more sensitive than the Scoliometer in detecting thoracic curves measuring 20 degrees or more by the Cobb method. Receiver operating characteristic curve analysis suggests that the use of the Scoliometer marginally improves the ability of diagnosing a scoliosis in the thoracic spine. CONCLUSIONS: The Scoliometer and Adam's forward bend tests have adequate interexaminer reliability for the assessment of thoracic curves. The Scoliometer has better interexaminer agreement in the lumbar spine. However, the Scoliometer has a high level of interexaminer measurement error that limits its use as an outcome instrument. Because Adam's forward bend test is more sensitive than the Scoliometer, the authors believe that it remains the best noninvasive clinical test to evaluate scoliosis.     

Anti-laminin reactivity and glomerular immune deposition by in vitro recombinant antibodies

Growing evidence suggests that recombinatorial events prior to antigen contact can generate pathogenic autoantibodies in the nonautoimmune individual, thus providing potential disease mediators if conditions arise that permit bypass of tolerance and activation of autoreactive lymphocytes. To examine the disease potential of selected germline antibody genes, Ig were created de novo by in vitro recombination of Ig H and L chains. H chain loss variant (i.e., L-chain only) cell lines were transfected with a DNA construct encoding the variable region and regulatory sequences (LamH) of a nephrotropic murine lupus anti-laminin Ig, and the resultant Ig were examined for in vitro antigen reactivity and in vivo glomerular immune deposition. The results indicate that two light chains, LamL (Vk8, Jk5) and 238L (Vk4, Jk5), expressing unrelated germline V1 genes, combine with LamH to generate Ig that bind basement membrane laminin in vitro, diverge in their capacity to bind ssDNA, and produce two distinct patterns of glomerular immune deposits in vivo: dense mesangial matrix (LamH/LamL) and dramatic linear glomerular basement membrane (LamH/238L) deposits. The Ig genes used by both LamH and 238L are present in nonautoimmune mice as well as in lupus-prone strains. We conclude that certain unmutated Ig genes can contribute to multiple distinct disease associated specificities, including binding to intrinsic kidney antigens, and that mutation is not essential to generate these Ig. Collectively, these observations suggest that pathogenic autoantibodies can be generated in the normal preimmune repertoire by random recombinatorial and somatic events in the absence of mutation.     

Using Generic Pheromone Lures to Expedite Identification of Aggregation Pheromones for the Cerambycid Beetles Xylotrechus nauticus, Phymatodes lecontei, and Neoclytus modestus modestus

Males of several species of longhorned beetles in the subfamily Cerambycinae produce sex or aggregation pheromones consisting of 2,3-hexanediols and/or hydroxyhexanones. We tested the hypothesis that this diol/hydroxyketone pheromone motif is highly conserved within the subfamily, and the resulting prediction that multiple cerambycine species will be attracted to compounds of this type. We also tested the concept that live traps baited with generic blends of these compounds could be used as a source of live insects from which pheromones could be collected and identified. Traps placed in a mature oak woodland and baited with generic blends of racemic 2-hydroxyhexan-3-one and 3-hydroxyhexan-2-one captured adults of both sexes of three cerambycine species: Xylotrechus nauticus (Mannerheim), Phymatodes lecontei Linsley, and Phymatodes decussatus decussatus (LeConte). Odors collected from male X. nauticus contained a 9:1 ratio of two male-specific compounds, (R)- and (S)-3-hydroxyhexan-2-one. Field trials with synthetic compounds determined that traps baited with (R)-3-hydroxyhexan-2-one (94% ee), alone or in blends with other isomers, attracted similar numbers of X. nauticus of both sexes, whereas (S)-3-hydroxyhexan-2-one (94% ee) attracted significantly fewer beetles. Phymatodes lecontei and P. d. decussatus also were caught in traps baited with hydroxyhexanones, as well as a few specimens of two other cerambycine species, Neoclytus modestus modestus Fall (both sexes) and Brothylus gemmulatus LeConte (only females). Male N. m. modestus produced (R)-3-hydroxyhexan-2-one, which was not present in extracts from females. Neoclytus m. modestus of both sexes also responded to lures that included (R)-3-hydroxyhexan-2-one as one of the components. The only male-specific compound found in extracts from P. lecontei was (R)-2-methylbutan-1-ol, and adults of both sexes were attracted to racemic 2-methylbutan-1-ol in field bioassays. Surprisingly, P. lecontei of both sexes also were attracted to (R)- and (S)-3-hydroxyhexan-2-ones, although neither compound was detected in extracts from this species. Males of all five beetle species had gland pores on their prothoraces that were similar in structure to those that have been associated with volatile pheromone production in other cerambycine species. The attraction of multiple cerambycine species of two tribes to (R)-3-hydroxyhexan-2-one in this study, and in earlier studies with other cerambycine species, suggests that this compound is a widespread aggregation pheromone component in this large and diverse subfamily. Overall, the attraction of multiple species from different cerambycine tribes to this compound at a single field site supports the hypothesis that the hydroxyketone pheromone structural motif is highly conserved within this subfamily.     

A Fourier-transform infrared study of CO2 and CO2/H2 interactions with caesium-doped copper catalysts

FTIR spectra are reported of CO₂ and CO₂/H₂ on a silica-supported caesium-doped copper catalyst. Adsorption of CO₂ on a “caesium”/silica surface resulted in the formation of CO₂ ⁻ and complexed CO species. Exposure of CO₂ to a caesium-doped reduced copper catalyst produced not only these species but also two forms of adsorbed carboxylate giving bands at 1550, 1510, 1365 and 1345 cm⁻¹. Reaction of carboxylate species with hydrogen at 388 K gave formate species on copper and caesium oxide in addition to methoxy groups associated with caesium oxide. Methoxy species were not detected on undoped copper catalyst suggesting that caesium may be a promoter for the methanol synthesis reaction. Methanol decomposition on a caesium-doped copper catalyst produced a small number of formate species on copper and caesium oxide. Methoxy groups on caesium oxide decomposed to CO and H₂, and subsequent reaction between CO and adsorbed oxygen resulted in carboxylate formation. Methoxy species located at interfacial sites appeared to exhibit unusual adsorption properties.     

Effect of growth temperature on the positional distribution of eicosapentaenoic acid andrans hexadecenoic acid in the phospholipids of aVibrio species of bacterium

Phosphatidylethanolamine (PE) and phosphatidylglycerol (PG) were isolated from aVibrio species of bacterium, known to produce eicosapentaenoic acid (20∶5n−3) andtrans-hexadecenoic acid (16∶1n−7), and subjected to phospholipase A₂ degradation to determine the positional distribution of component fatty acids. At the two growth temperatures studied (20 and 5°C), both 20∶5n−3 andtrans 16∶1 n−7 were located mainly at positionsn−2 in PE. Increases in the proportions of 20∶5n−3 andtrans 16∶1n−7 in positionsn−2 with decreasing growth temperature were balanced mainly by decreases in the level ofiso-15∶0. In PG,trans 16∶1n−7 was located predominantly in positionsn-1, although the difference between the two positions was not as great as in PE. Eicosapentaenoic acid was preferentially located in positionsn-2 of PG, particularly at 5°C when it comprised 29.9% of the total fatty acids in this position. It is concluded thattrans 16∶1n−7/20∶5n−3 is not a major molecular species of phospholipid in this species ofVibrio and that changes in the levels of molecular species of PE containingiso-15∶0 may feature in thermal acclimation.     

Detection of incremental and decremental bars at different locations across Mach bands and related stimuli

Two-alternative forced-choice procedures were used to measure the detectability of bright and dark bars at various locations across luminance patterns that produced Mach bands. Detection performance was significantly affected by both dark and bright Mach bands: poor detection performance was observed at locations near, but not in, the Mach bands; relatively good detection performance at locations within the Mach bands was caused by reliable changes in the width, depth, or symmetry of the bands produced by the signal bars. The changes were apparent with signals of lower luminance than that needed for detection in the plateau regions far from the bands, but, because the cues were not sufficiently reliable to allow errorless performance, unusually shaped psychometric functions were obtained.     

The use of discriminant analysis for the interpretation of the reflectance spectra of irradiated porcine M. longissimus dorsi

Slices of porcine M. longissimus dorsi were packed in overwrap packs and subjected to irradiation (0 and 5 kGy) and then stored for 7 days at 4°C. Reflectance spectra were measured on the outside surface and a freshly cut surface at 7 days post irradiation. The reflectance spectra were transformed to reflex attenuance, k/s and first and second difference spectra and subjected to discriminant analysis. Using discriminant analysis it was possible to establish a calibration equation to discriminate between the spectra of irradiated and unirradiated pork for both the outside and the inside surface. When the calibration model was used to predict the classification of new samples a 100% correct grouping was obtained for the freshly cut surface, however, for the outside surface the classification ranged from 87 to 100% correct depending on the mathematical transformation of the reflectance spectra. This shows the potential of colour measurements as a possible rapid initial screening test for the identification of irradiated pork. Evaluation of the first difference spectra to identify peak positions showed significant differences in peak positions between irradiated and unirradiated pork. The position of the peaks in the irradiated sample is discussed as lending support to the hypothesis of the carboxyhaem form as the irradiated pigment.     

The role of a single N-linked glycosylation site for a functional epitope of herpes simplex virus type 1 envelope glycoprotein gC

High altitude (HA) living produces physiological changes for adaptation to chronic hypobaric-hypoxemic conditions. Although much is known about these physiologic adaptations, no clear separation has been made regarding what is "native" or "genetic" adaptation and what is "acquired." In this review, we describe the genetic vs. acquired adaptation and only include studies performed in a population native to HA and not in an acclimatized population or trekkers. The changes encountered in animals and humans living at HA in terms of hematology, muscular, respiratory, cerebral, cardiovascular, hormonal, fluid and electrolytes and reproduction, strongly suggest that genetics play a very important role in HA adaptation. Unfortunately, the characteristic physiology of HA natives has not been systematically defined to established specific measurable parameters of adaptation in comparison to the acquired ambient adaptation of the non-native population. Once the parameters are established, we can compare non-native populations exposed to HA that must emulate the HA physiology for a definite adaptation to be present. With measurable parameters, especially in the management of fluids and electrolytes, we can define how long it will take for a sea level native to adapt to an HA altitude. Until these studies are performed, speculation will continue and no rational medical intervention can be offered to HA newcomers who may experience HA difficulties.