An EMA analysis of the effect of increasing word length on consonant production in apraxia of speech: a case study

The effect of increasing word length on the articulatory dynamics (i.e. duration, distance, maximum acceleration, maximum deceleration, and maximum velocity) of consonant production in acquired apraxia of speech was investigated using electromagnetic articulography (EMA). Tongue-tip and tongue-back movement of one apraxic patient was recorded using the AG-200 EMA system during word-initial consonant productions in one, two, and three syllable words. Significantly deviant articulatory parameters were recorded for each of the target consonants during one, two, and three syllables words. Word length effects were most evident during the release phase of target consonant productions. The results are discussed with respect to theories of speech motor control as they relate to AOS.     

Computed tomographic colonography: assessment of radiologist performance with and without computer-aided detection

BACKGROUND & AIMS: In isolation, computer-aided detection (CAD) for computed tomographic (CT) colonography is as effective as optical colonoscopy for detection of significant adenomas. However, the unavoidable interaction between CAD and the reader has not been addressed. METHODS: Ten readers trained in CT but without special expertise in colonography interpreted CT colonography images of 107 patients (60 with 142 polyps), first without CAD and then with CAD after temporal separation of 2 months. Per-patient and per-polyp detection were determined by comparing responses with known patient status. RESULTS: With CAD, 41 (68%; 95% confidence interval [CI], 55%-80%) of the 60 patients with polyps were identified more frequently by readers. Per-patient sensitivity increased significantly in 70% of readers, while specificity dropped significantly in only one. Polyp detection increased significantly with CAD; on average, 12 more polyps were detected by each reader (9.1%, 95% CI, 5.2%-12.8%). Small- (< or =5 mm) and medium-sized (6-9 mm) polyps were significantly more likely to be detected when prompted correctly by CAD. However, overall performance was relatively poor; even with CAD, on average readers detected only 10 polyps (51.0%) > or =10 mm and 24 (38.2%) > or =6 mm. Interpretation time was shortened significantly with CAD: by 1.9 minutes (95% CI, 1.4-2.4 minutes) for patients with polyps and by 2.9 minutes (95% CI, 2.5-3.3 minutes) for patients without. Overall, 9 readers (90%) benefited significantly from CAD, either by increased sensitivity and/or by reduced interpretation time. CONCLUSIONS: CAD for CT colonography significantly increases per-patient and per-polyp detection and significantly reduces interpretation times but cannot substitute for adequate training.     

Disrupted muscarinic M1 receptor signaling correlates with loss of protein kinase C activity and glutamatergic deficit in Alzheimer's disease

There are few studies on the clinical and neurochemical correlates of postsynaptic cholinergic dysfunction in Alzheimer's disease (AD). We have previously found that attenuation of guanine nucleotide-binding (G-) protein coupling to muscarinic M(1) receptors in the neocortex was associated with dementia severity. The present study aims to study whether this loss of M(1)/G-protein coupling is related to alterations in signaling kinases and NMDA receptors. Postmortem frontal cortices of 22 AD subjects and 12 elderly controls were obtained to measure M(1) receptors, M(1)/G-protein coupling, NMDA receptors as well as protein kinase C (PKC) and Src kinase activities. We found that the extent of M(1)/G-protein coupling loss was correlated with reductions in PKC activity and NMDA receptor density. In contrast, Src kinase activity was neither altered nor associated with M(1)/G-protein coupling. Given the well established roles of neuronal PKC signaling and NMDA receptor function in cognitive processes, our results lend further insight into the mechanisms by which postsynaptic cholinergic dysfunction may underlie the cognitive features of AD, and suggest alternative therapeutic targets to cholinergic replacement.     

Resting posterior versus frontal delta/theta EEG activity is associated with extraversion and the COMT VALMET polymorphism

Recent studies suggest that resting posterior versus frontal EEG delta/theta activity (delta/theta Pz–Fz) is both sensitive to pharmacological manipulations of neural dopamine and associated with the agency facet of extraversion (i.e., a motivational disposition comprising enthusiasm, energy, assertiveness, achievement striving and social dominance). These observations suggest that posterior versus frontal resting EEG delta/theta activity may represent a useful marker for investigating the molecular genetic basis of extraversion. The present study aimed to test the novel hypothesis of an association between delta/theta Pz–Fz and a functional polymorphism of the enzyme catechol-O-methyltransferase (COMT VAL¹⁵⁸MET) involved in dopamine catabolism. This was conducted in a large EEG data set from the Brain Resource International Database (BRID; resting EEG from N = 1093 healthy individuals, 382 of which also genotyped for COMT VAL¹⁵⁸MET). In summary, we (1) showed for the first time that the VAL allele is associated with increased delta/theta Pz–Fz; (2) replicated the association between extraversion and delta/theta Pz–Fz in a large, heterogeneous sample including both genders; and (3) documented that the VAL allele of the COMT VAL¹⁵⁸MET is associated with increased extraversion scores, as previously reported for an overlapping BRID sample. This coherent pattern of findings adds further support to the suggestion that the posterior–anterior distribution of resting EEG slow wave activity in the delta/theta range represents a useful tool for probing the dopaminergic basis of extraversion.     

<Emphasis Type=Italic>Pseudopecoelus sosoae</Emphasis> sp. nov. and <Emphasis Type=Italic>P. sewelli</Emphasis> (Digenea,Opecoelidae) from the deep-sea fish <Emphasis Type=Italic>Neoscombrops pacificus</Emphasis> (Perciformes,Acropomatidae) off New Caledonia

Pseudopecoelus sosoae sp. nov. and P. sewelli Bray, 1990 are described from the rare fish Neoscombrops pacificus from the deep-sea (about 200–400 m) off Nouméa, New Caledonia, the southernmost report of this fish species. A visual key based on 12 characters is presented, which shows that P. sosoae is distinguished from the most similar species (P. vulgaris, P. elongatus, P. priacanthi, P. akamachi and P. sphyraenae) by its very large eggs, elongate body and unlobed gonads. P. sewelli has a similar shape, but much smaller eggs and lobed gonads.     

<Emphasis Type=Italic>Varialvus</Emphasis> gen. nov. (Digenea,Cryptogonimidae), from species of Lutjanidae (Perciformes) off the Great Barrier Reef,New Caledonia and the Maldives

A survey of the cryptogonimid trematode fauna infecting Indo-West Pacific Lutjanidae (Perciformes) revealed the presence of four new species whose morphological and genetic differences relative to all other known cryptogonimids warrants the proposal of a new genus, Varialvus gen. nov. Species of this new genus were recovered from sites off Heron and Lizard Islands on the Great Barrier Reef, Australia, New Caledonia and Rasdhoo Atoll, Maldives. Varialvus gen. nov. is distinguished from all other cryptogonimid genera by the combination of a fusiform to oval body, the relatively small number of large oral spines, a median ovary which is relatively condensed and highly lobed, opposite to slightly oblique testes, uterine loops that are restricted to the hindbody and extend well posterior to the testes, and vitelline follicles that are mainly in the forebody but may extend from the anterior margin of the ovary to anterior to the intestinal bifurcation. Bayesian inference analysis of partial large subunit (LSU) rDNA sequence data for these species revealed that they formed a monophyletic clade, despite V. charadrus sp. nov. having a distinctly muscular gonotyl, which based on morphological characters alone may have warranted placement in a separate genus in the absence of DNA sequence data. At least one species of Varialvus gen. nov. is apparently widespread in the Indo-West Pacific. Three species, V. lacertus sp. nov., V. jenae sp. nov. and V. angustus sp. nov. have each been found at only one locality, but V. charadrus sp. nov. was recovered from lutjanids off the Great Barrier Reef, New Caledonia and the Maldives, demonstrating a biogeographic range of at least 10,000 kilometres. Siphoderina lutjani (Saoud, Ramadan et Al Kawari, 1988) Miller et Cribb, 2008 is transferred here as V. lutjani (Saoud, Ramadan et Al Kawari, 1988) n. comb. based on morphological and host group agreement with species of Varialvus gen. nov.     

Differences in overnight polysomnography scores using the adult and pediatric criteria for respiratory events in adolescents

Study Objectives:

There was no consensus in the 2007 American Academy of Sleep Medicine scoring manual on whether pediatric or adult respiratory criteria should be used in adolescents due to lack of data. Our objective was to compare pediatric and adult criteria in adolescents referred for obstructive sleep apnea (OSA). We hypothesized that pediatric criteria would capture more respiratory events than adult criteria.

Design:

Retrospective cross-sectional analysis.

Setting:

Clinical sleep laboratory.

Participants:

101 subjects aged 13-18 years clinically referred for OSA.

Interventions:

Overnight polysomnogram. Data were scored using both adult and pediatric AASM criteria. For adult criteria, data were scored using both AASM hypopnea rule A, defined by ≥ 4% desaturation, and B, defined by ≥ 3% desaturation or arousal.

Results:

Median (range) apnea hypopnea index (AHI) by pediatric criteria was 1.7 events/hour (0–42.9). AHI using rule A was 0.4 (0–35.6); rule B, 1.4 (0–38.4). A higher pediatric AHI was associated with greater differences between pediatric and adult AHI using either rule A or B. There was no significant discordance in OSA classification comparing pediatric and adult criteria rule B (P = 0.3), but there was a significant rate of discordance classification comparing pediatric and adult criteria rule A (P < 0.001).

Conclusions:

Either pediatric or adult criteria rule B can be used in adolescents as few subjects change diagnostic category between these 2 criteria. Use of adult rule A results in fewer children meeting criteria for OSA. Further research into the clinical relevance of the scoring metric in adolescents is warranted.

Citation:

Accardo JA; Shults J; Leonard MB; Traylor J; Marcus CL. Differences in overnight polysomnography scores using the adult and pediatric criteria for respiratory events in adolescents. SLEEP 2010;33(10):1333-1339.