Genetic susceptibility to dental caries on pit and fissure and smooth surfaces

Carious lesions are distributed nonuniformly across tooth surfaces of the complete dentition, suggesting that the effects of risk factors may be surface-specific. Whether genes differentially affect caries risk across tooth surfaces is unknown. We investigated the role of genetics on two classes of tooth surfaces, pit and fissure surfaces (PFS) and smooth surfaces (SMS), in more than 2,600 subjects from 740 families. Participants were examined for surface-level evidence of dental caries, and caries scores for permanent and/or primary teeth were generated separately for PFS and SMS. Heritability estimates (h(2), i.e. the proportion of trait variation due to genes) of PFS and SMS caries scores were obtained using likelihood methods. The genetic correlations between PFS and SMS caries scores were calculated to assess the degree to which traits covary due to common genetic effects. Overall, the heritability of caries scores was similar for PFS (h(2) = 19-53%; p < 0.001) and SMS (h(2) = 17-42%; p < 0.001). Heritability of caries scores for both PFS and SMS in the primary dentition was greater than in the permanent dentition and total dentition. With one exception, the genetic correlation between PFS and SMS caries scores was not significantly different from 100%, indicating that (mostly) common genes are involved in the risk of caries for both surface types. Genetic correlation for the primary dentition dfs (decay + filled surfaces) was significantly less than 100% (p < 0.001), indicating that genetic factors may exert differential effects on caries risk in PFS versus SMS in the primary dentition.     

Increasing the sensitivity of the Story Retell Procedure for the discrimination of normal elderly subjects from persons with aphasia

Background: Clinicians have long recognised the need for assessing language production at multiple levels of complexity and at impairment, participation, and activity levels. Methods for the elicitation of connected spoken language have taken many forms, typically selected with a balance between validly sampling linguistic performance, and reliability and economy of the sampling and scoring procedures. A Story Retell Procedure (SRP) has been proposed as a preferred method for achieving valid, reliable, and economic assessment of connected language (Doyle et al., 2000), and an information unit (IU) metric has been developed for validly and economically capturing important linguistic aspects of the retelling (McNeil, Doyle, Fossett, Park, & Goda, 2001). Aims: In keeping with the goal of making assessment procedures as efficient and economic as possible, a study was undertaken to investigate the refinement of the IU metric for increasing the sensitivity of the SRP as an instrument for the detection of connected paragraph-level language production deficits in persons with aphasia. This metric involved the calculation of the percentage of IUs (%IU) produced relative to the time taken to produce them (%IU/Min). Methods & Procedures: A total of 15 persons with aphasia, and 31 normal control individuals without a communication disorder served as participants for this study. Subjects heard, and immediately retold each of 12 stories originally taken from the Discourse Comprehension Test (Brookshire & Nicholas, 1997). The retellings were scored using the procedures outlined by McNeil et al. (2001) with the addition of the %IU calculated over the time of the retelling. Comparisons between subject groups and groups stratified by age, among SRP forms, between scoring methods (%IU vs %IU/Min.), and group misclassification by scoring method were made. Outcome & Results: Application of the %IU/Min with the SRP yielded equivalence among alternate forms as evidenced by non-significant differences and high correlation coefficients among the SRP forms for persons with aphasia. The %IU/Min also decreased the percentage of misclassified aphasic and normal individuals compared to the %IU measure. Older normal subjects were misclassified as aphasic with greater frequency compared to the younger normal subjects. Conclusions: The %IU/Min is a more sensitive metric than the %IU in differentiating individuals with aphasia from older normal controls.     

Examining the facilitative effects of rhyme in a patient with output lexicon damage

A theory-driven treatment was designed to facilitate access to the impaired output lexicons of a 47-year-old woman with aphasia resulting from a left parietal haemorrhage. In the context of a multiple-baseline design, lists of rhymed word pairs from four semantic categories were trained using a systematic cueing hierarchy. Performance measures were based on the subject's generation of targeted words, verbally and in writing, when presented with a rhyme of the target. Results demonstrated positive acquisition, generalization and maintenance effects for treated and untreated items across semantic categories. Delayed generalization patterns may be explained by retrieval inhibition (Blaxton and Bookheimer 1993) or lateral inhibition (McClelland and Rumelhart 1981).     

Assessing the validity of multiple‐choice questions for RAPP story comprehension

Background: Passage dependency (PD) is a measure of how much information is required to answer test questions based only on information provided in the relevant text (Tuiman, 1974). Prior learning, information included in other test questions or responses, and the ability to eliminate less plausible or irrelevant foils are all factors that may affect PD. The PD of the multiple‐choice questions for the auditory story comprehension task in the RAPP software environment has yet to be established. Aims: The purpose of this experiment was to investigate the validity of newly developed multiple‐choice comprehension questions for the story comprehension tasks used in the RAPP software environment. Methods & Procedures: Participants were 40 young adults without speech or language impairment, 20 of whom heard each of 12 stimulus stories and answered 10 multiple‐choice questions with 5 response choices, and 20 who answered the multiple‐choice questions but were not exposed to the stimulus stories. Questions concerned information about stated and implied main ideas and details presented in the stories. Based on four pre‐determined story forms (three stories each), analyses examined the questions' validity in terms of their PD compared to chance performance and to a pre‐established Passage Dependency Index (PDI) criterion (.60). Significant differences in the PDI and in the percentage of correctly answered questions among predetermined forms were also evaluated. Analyses also examined the PD of questions based on the type of information queried both within and among forms. Outcomes & Results: Results provide support for the validity of the multiple‐choice questions without consideration of the nature of the information queried by them. The percentage of correctly answered questions exceeded chance for all story forms, PDIs met or exceeded the pre‐established criterion, there were no significant differences in the PDIs among the four forms and there were no significant differences in the percentage of correctly answered questions among the four forms. There were no significant differences in the PDIs among the four question types by story form or among question types within a form and all PDIs met or exceeded pre‐established criteria (except detail implied questions in one form). Conclusions: These results provide support for the PD of the multiple‐choice questions constructed for the four story forms that make up this version of a story‐length auditory comprehension task. Results suggest that the questions are not biased relative to the content of the stories and results add to the overall validity of the task.     

Measuring communicative functioning in community‐dwelling stroke survivors: Conceptual foundation and item development

Background: Studies employing item response theory methods to evaluate communicative functioning assessment items have found that a broad range of communication tasks and activities may fit a unidimensional measurement model, but that additional item content is needed to extend the range of ability effectively measured by the small subset of items that have been evaluated.

Aims: To describe the item identification, evaluation, and development process used to substantiate the content relevance and representativeness of a set of communicative functioning assessment items targeting community‐dwelling stroke survivors.

Methods & Procedures: Electronic and secondary references were searched to identify assessment tools with item content designed to measure communicative functioning in adults with neurogenic communication disorders. Candidate items were evaluated using face‐to‐face interviewer‐assisted survey groups conducted independently with communicatively impaired stroke survivors (n = 59) and their communicative partners (n = 61). Web‐based surveys were employed to evaluate candidate items from the perspective of practising speech‐language pathologists (n = 114).

Outcomes & Results: A total of 673 items were identified from 33 instruments. A total of 426 met the specified concept definition; 211 were determined to be non‐redundant; 166 were identified by key stakeholders as unambiguous, relevant, and moderately to very important to daily functioning.

Conclusions: The item pool developed samples a representative range of communication behaviours, activities, and life situations that are relevant to community‐dwelling stroke survivors. Further research using item response theory methods is required to substantiate the construct dimensionality and range of ability effectively measured by the item pool, and to evaluate dynamic assessment algorithms designed to minimise response burden.     

A dual-task tool for quantifying normal comprehension of aphasic connected speech production: A constructive replication

Background: Deficits of attention or its control secondary to brain damage have been proposed as all or part of the underlying mechanisms for the linguistic impairments that characterise aphasia (Clark & Robin, 1995; Granier, Robin, Shapiro, Peach, & Zimba, 2000; McNeil, 1982, 1988; McNeil, Odell, & Tseng, 1991; Murray, Holland, & Beeson, 1997a; Tseng, McNeil, & Milenkovic, 1993). McNeil, Doyle, Hula, Rubinsky, Fossett, and Matthews (2004) developed a set of tasks to quantify the difficulty that normal listeners have in understanding the language production of persons with varying amounts of aphasia. In their dual-task study, a significant decrement was found in the visual–manual tracking accuracy of normal older individuals while concurrently listening to the connected language of a person with moderate, as compared to mild, aphasia. No performance costs were observed on the listening tasks across three tracking difficulty levels. Possible reasons for the unidirectional performance cost were speculated and the present study was designed to investigate one of them.Aims: Using the same story comprehension task used in the previous study and the same visual–manual tracking task, but increased in difficulty, this study sought to investigate whether the increased demands of the tracking task were sufficient to elicit a concurrent cost on story comprehension performance.Methods & Procedures: A total of 24 normal participants performed the tracking and story comprehension tasks concurrently and in isolation. Story retell performance was evaluated within subjects across two tracking difficulty levels (easy and hard) and tracking performance was evaluated between subjects across three story difficulty levels (no story, mild difficulty, and moderate difficulty).Outcomes & Results: Tracking performance varied significantly across story task difficulty in the easy tracking condition, with participants demonstrating better tracking performance in the mild story condition than in either the moderate story or no story conditions. None of the comparisons made with the harder tracking condition reached significance. There was no effect of tracking difficulty on story comprehension as measured by subsequent story retell performance.Conclusions: The findings from this study replicate the findings from the McNeil et al. (2004) study that these dual-tasks show a reliable cost of story difficulty on concurrent tracking performance. Contrary to predictions, no effect of tracking difficulty on story retell performance was found, despite the increased tracking difficulty used compared to the previous study. While this finding does diminish the probability that insufficient tracking task difficulty was the source of the unidirectional costs in the previous study, it leaves a number of alternative explanations for the findings viable and unaddressed.     

Reliability and concurrent validity of the information unit scoring metric for the story retelling procedure

This study reports the reliability and concurrent validity of the information units (IU) metric as an efficient method for quantifying the amount of information comprehended and reproduced on the Story Retelling Procedure (SRP) (Doyle et al., 2000). Subjects were 31 normal adults and 15 adults with aphasia. Significant and moderately high correlation coefficients were obtained for subjects with aphasia between %IUs and most linguistic measures including the correct information unit (Nicholas & Brookshire 1993, 1995) while low and non-significant correlations were found for many measures of language productivity, efficiency, and disruption. The %IUs among the four SRP forms within group was non-significant (p > .05) and correlations were significant and high. Normal speakers produced significantly greater %IUs than aphasic speakers. Standard error of measurement was low across forms for both groups (3-4%) and the range of individual subjects' performance overlapped between 20 and 27%for the group with aphasia and between 36 and 55% for the normal group. These results support the conclusion that %IU is a reliable and valid measure and differentiates aphasic from normal individuals better than normal individuals from persons with aphasia.     

Effects of training multiple form classes on acquisition,generalization and maintenance of word retrieval in a single subject

Abstract

A study by McNeil et al. reported no generalization effects in two individuals with aphasia following application of a word finding treatment in which subjects were trained sequentially on lexical items arranged by form class. The present investigation examined, in one of the two subjects from the original study, whether training on lexical items from a variety of form classes concurrently would result in greater response generalization than was observed previously in this subject. Results replicated earlier findings with positive acquisition and maintenance effects and little evidence of generalization to untrained items within or across form classes.     

白花蛇舌草-半枝莲药对组分对结肠腺癌Lovo细胞生物学行为的影响

摘要:目的　探讨白花蛇舌草-半枝莲药对组分对结肠腺癌Lovo细胞增殖、侵袭、迁移和凋亡的影响及作用机制。方法　将白花蛇舌草、半枝莲按质量1∶1进行3次煎煮,获得水提物,后取适量浸膏用石油醚回流脱脂,再以乙酸乙酯进行多次萃取,获得白花蛇舌草-半枝莲药对组分,并计算得率。实验分为对照组（正常培养Lovo细胞）、白花蛇舌草-半枝莲药对组分低剂量组（10 mg/L）、中剂量组（30 mg/L）及高剂量组（50 mg/L）。通过噻唑蓝比色法（MTT）检测各组细胞培养24、48、72 h后的增殖抑制率。各组细胞培养48 h后,流式细胞仪检测细胞周期分布;Transwell实验检测细胞侵袭能力;划痕实验检测细胞迁移能力;TUNEL法检测细胞凋亡情况;Western blot法检测Grb2相关结合蛋白1（Gab1）、血管内皮生长因子受体2（VEGFR-2）、磷脂酰肌醇3-激酶（PI3K）、苏氨酸激酶（Akt）、基质金属蛋白酶-9（MMP-9）、B淋巴细胞瘤-2基因（Bcl-2）、Bcl-2相关X蛋白（Bax）蛋白表达情况。结果　化学萃取后的白花蛇舌草-半枝莲药对中主要含有对羟基苯乙酮、野黄芩苷、木犀草素和芹菜素4种化合物,组分得率为0.61%。与对照组相比,低、中、高剂量组细胞增殖抑制率升高,G1期肿瘤细胞比例增加,细胞凋亡指数增高,侵袭细胞数和划痕闭合率明显减小（均P＜0.05）,细胞中Gab1、VEGFR-2、PI3K、Akt、MMP-9、Bcl-2蛋白表达降低,Bax表达升高（均P＜0.05）,且存在剂量依赖性。结论　白花蛇舌草-半枝莲药对组分可抑制结肠腺癌Lovo细胞的增殖,降低其迁移和侵袭能力,诱导细胞凋亡,其机制可能与抑制Gab1/VEGFR-2/PI3K/Akt信号通路活化有关。     

The floating cardiac fat pad—sign of occult pneumothorax

Pneumothoraces are a possible sequela of chest trauma with potential morbidity and mortality if not recognized and treated promptly. A portable supine chest radiograph is frequently the first radiologic study performed in the setting of trauma. While large pneumothoraces can be readily recognized on these radiographs, smaller pneumothoraces are missed in up to 15 % of trauma patients. There are many radiographic signs of occult pneumothoraces, and we are presenting a new radiographic sign of occult pneumothorax. The floating cardiac fat pad sign occurs when pleural air collects anteriorly and superiorly in the most non-dependent portion of the chest lifting the pericardial fat pad off the diaphragm. Lung markings are still seen surrounding the pericardial fat pad due to the inflated lower lobe of the lung resting dependently. Rapid and accurate identification of pneumothoraces is critical but often difficult on chest radiographs. Although there are many existing radiographic signs for identification of pneumothorax, prospective identification of small pneumothoraces is still relatively poor. Here, we describe an additional sign which aides in the detection of pneumothoraces, the floating cardiac fat pad. When present, this should prompt further evaluation with chest CT or upright chest radiograph.