Touch-and-feel features in "first words" picture books hinder infants' word learning

Little is known about the role of book features in infant word learning from picture books. We conducted a preregistered study to assess the role of touch-and-feel features in infants' ability to learn new words from picture books. A total of 48 infants (Mage = 16.75 months, SD = 1.85) were assigned to a touch-and-feel picture-book condition or a standard picture-book condition (no touch-and-feel features) and were taught a novel label for an unfamiliar animal by the researcher during a book-reading session. Infants were then tested on their ability to recognize the label (i.e., choose the target from a choice of two pictures on hearing it named) and to generalize this knowledge to other types of pictures and real-world objects (scale model animals and stuffed animals). Infants in the no touch-and-feel condition performed above chance when choosing the target picture, whereas infants in the touch-and-feel condition did not. Infants in both conditions failed to generalize this knowledge to other pictures and objects. This study extends our knowledge about the role of tactile features in infant word learning from picture books. Although manipulative features like touch-and-feel patches might be engaging for infants, they may detract from learning. Depending on the purpose of the activity, parents and practitioners might find it useful to consider such book features when selecting books to read with their infants.

Testing mechanisms underlying children's reading development: The power of learning lexical representations

Prominent theories of reading development have separately emphasized the relevance of children's skill in learning (Share, 2008) and lexical representations (Perfetti & Hart, 2002). Integrating these ideas, we examined whether skill in learning lexical representations is a mechanism that might explain children's reading development. To do so we conducted a longitudinal study, following 139 children from Grades 3 to 5. In Grade 3, children completed measures of word reading and reading comprehension and again at Grade 5. In Grade 4, children read short stories containing novel words; they were later tested on their memory for the spellings and meanings of these new words, capturing orthographic and semantic learning, respectively. Using multiple-mediation path analysis, we tested whether children's skill in learning orthographic and semantic dimensions of new words was a mediator of individual differences in each of word reading and reading comprehension. In models controlling for nonverbal ability, working memory, vocabulary, and phonological awareness, we found two clear effects: individual differences in orthographic learning at Grade 4 mediated the gains that children made in word reading between Grades 3 and 5 and individual differences in semantic learning at Grade 4 mediated gains in reading comprehension over the same time period. These findings suggest that children's ability to learn lexical representations is a mechanism in reading development, with orthographic effects on word reading and semantic effects on reading comprehension. These findings show the power and the specificity of children's capacity to learn in determining their progress in learning to read. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Using a willingness to wait design to assess how readers value text

What affects moment-to-moment motivation to read? Existing reading motivation questionnaires are trait-based and not well suited to capturing the dynamic, situational influences of text or social context. Drawing on the decision science literature, we have created a paradigm to measure situational enjoyment during reading. Using this paradigm, we find reading enjoyment is associated with further decision-making about the text and with reading comprehension.

The contributions of decoding skill and lexical knowledge to the development of irregular word reading

Two recent computational models of reading development propose that irregular words are read using a combination of decoding and lexical knowledge but differ in assumptions about how these sources of information interact and about the relative importance of different aspects of lexical knowledge. We report developmental data that help to adjudicate these differences. Study 1 adopted a correlational approach to investigate the item-level relations between the ability to read a word aloud, general decoding ability, and knowledge of the word's phonological form (lexical phonology) or meaning (lexical semantics). We found that the latter three factors all influenced accuracy of oral reading. We observed trends indicating that the impact of differences in decoding skill and lexical knowledge were more prominent for irregular words. Study 2 comprised two experiments in which novel irregular words were taught; in Experiment 1 we compared phonological to no pretraining, whereas in Experiment 2 we compared phonological to phonological plus semantics pretraining. Exposure to the phonological form of the word had a substantial impact in the early stages of learning, whereas the impact of adding semantics was more modest and emerged later. Our findings provide strong evidence that irregular words are read using a combination of decoding and lexical knowledge, with a greater contribution from lexical phonology than lexical semantics. Computational models of learning to read are currently unable to fully account for our data, therefore we propose some modifications. We advocate an instructional approach whereby phonics and vocabulary teaching are combined to support irregular word reading. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Tracking vocabulary and reading growth in children from lower and higher socioeconomic backgrounds during the transition from primary to secondary education

We examined the relation between socioeconomic status (SES), vocabulary, and reading in middle childhood, during the transition from primary (elementary) to secondary (high) school. Children (N = 279, 163 girls) completed assessments of everyday and curriculum-related vocabulary, (non)word reading, and reading comprehension at five timepoints from age 10 to 13. Piecewise linear mixed-effects models showed significant growth in everyday vocabulary and word reading between every time point. Curriculum vocabulary and reading comprehension showed significant growth during the school year, but not during the summer holidays. There were significant effects of SES on all measures except word reading; yet, SES differences did not widen over time. Our findings motivate targeted reading and vocabulary support for secondary school students from lower SES backgrounds.

Reading fiction and reading minds in early adolescence: A longitudinal study

Reading fiction is argued to have benefits for our understanding of others' thoughts, feelings and desires, referred to as 'theory of mind'(ToM). We aimed to test this assumption by examining whether children's reading experience is longitudinally associated with later ToM. We examined reading experience and ToM in 236 children between the ages of 11-13 years. Participants were asked to report on their time spent reading both fiction and non-fiction at ages 11 and 13, ToM was measured at age 13. Verbal ability, reading comprehension, and reading motivation were included as control variables in all analyses. Results showed that children's self-reported fiction, but not their non-fiction reading was associated with ToM. Further, the association was concurrent but not longitudinal: fiction reading and ToM at age 13 were associated but fiction reading at age 11 did not predict ToM at age 13. Our findings motivate further research on what types of reading materials might be beneficial, and the level of exposure to fiction that is needed for measurable benefits for later ToM.

Educators' Perceptions of Barriers and Facilitators to the Implementation of Screeners for Developmental Language Disorder and Dyslexia

Developmental language disorder (DLD) and dyslexia are common but under-identified conditions that affect children's ability to read and comprehend text. Universal screening is a promising solution for improving under-identification of DLD and dyslexia, however, we lack evidence for how to effectively implement and sustain screening procedures in schools. In the current study, we solicited input from educators in the U.S. around perceived barriers and facilitators to the implementation of researcher-developed screeners for DLD and dyslexia. Using thematic analysis, we identified barriers and facilitators within five domains: (1) features of the screeners, (2) preparation for screening procedures, (3) administration of the screeners, (4) demands on users, and (5) screening results. We discuss these findings and ways we can continue improving our efforts to maximize the contextual fit and utility of screening practices in schools.

Building Sustainable Models of Research-Practice Partnerships Within Educational Systems

PURPOSE

To describe the 9-year journey of a group of language and literacy researchers in establishing and cultivating Research-Practice Partnerships (RPPs). Those interested in incorporating implementation science frameworks in their research may benefit from reading our exploration into this type of work and our lessons learned.

METHOD

We showcase how a group of researchers, who are committed to collaboration with school practitioners, navigated building and scaling RPPs within educational systems necessary for our long-term implementation work. We provide details and illustrative examples for three, distinct, mutually beneficial, and sustainable partnerships.

RESULTS

Three different practice organizations are represented: (1) a single metropolitan school, (2) a small metropolitan school district, and (3) a large metropolitan school district, highlighting specific priorities and needs depending on the type of practice organization. Each partnership has distinct research and practice goals related to improving language and literacy outcomes in children. We describe how the researchers assisted with meeting the partner practice organizations' goals and engaged in capacity building while producing rigorous scientific knowledge to inform clinical and educational practice. Additionally, we discuss how research priorities and strategies were pivoted in the past year due to the COVID-19 pandemic, illustrating our commitment to the partnerships and how to respond to challenges to guarantee long-term sustainability.

CONCLUSION

By discussing three distinctive partnerships, we demonstrate the various ways researchers can approach RPPs and grow them into mutually beneficial collaborations and support implementation goals.

Finding the man amongst many: A developmental perspective on mechanisms of morphological decomposition

Skilled reading is characterized by rapid recognition of morphologically complex words. Evidence suggests that adult readers segment complex words into their constituent morphemes during visual word recognition, and that this extends to items that have only a surface morphological structure (e.g., corner), a process termed 'morpho-orthographic segmentation'. It is not yet known how and when this mechanism is established over the course of reading development, although data from English-speaking children suggest that it may be a relatively late-acquired milestone. The purpose of this study was to examine for the first time the mechanisms driving morphological processing across late childhood and adolescence. A cross-sectional sample of 204 children and adolescents from South-East England, ranging in age from 9 to 18 years (M age = 13.74 years, SD = 2.68; 110 female), completed a visual masked prime lexical decision task using three sets of prime-target pairs: morphological (e.g., teacher - TEACH), pseudomorphological (sharing an apparent morphological relationship in the absence of a semantic relationship, e.g., corner - CORN), and form (sharing an orthographic relationship only, e.g., window - WIND). Linear mixed effects models revealed both morphological and pseudomorphological priming in the absence of form priming, with priming magnitude increasing in line with age, and stronger evidence of morpho-orthographic segmentation emerging in line with word reading efficiency. Our findings reveal advances in the reading system during adolescence which may reflect accumulated exposure to regularities in the writing system, facilitating rapid access to meaning from print.

To See or Not to See: How Does Seeing Spellings Support Vocabulary Learning?

Purpose

The aim of this study was to determine when, why, and how the presence of a word's written form during instruction aids vocabulary learning (a process known as orthographic facilitation ).

Method

A systematic review of the research on orthographic facilitation was carried out. PsycInfo, Web of Science, ProQuest, and OpenGrey databases were searched. The search returned 3,529 results, and 23 of these met inclusion criteria. Studies were included in the review if they were written in English, published in a peer-reviewed journal, and compared vocabulary learning outcomes when words were taught with and without their written forms.

Conclusions

There is strong evidence that the presence of a word's written form leads to improved learning of its spelling and spoken form. There is also some evidence that it may lead to better learning of a word's meaning. A small number of studies have also shown that the presence of a word's written form benefits vocabulary learning in children with developmental language disorder, autism, Down syndrome, and reading difficulties. However, further research into the effects of orthographic facilitation in special populations is needed. In particular, ecologically valid experiments in clinical and educational settings are required in order to better understand how exposure to a word's written form can aid naturalistic vocabulary learning.

Early Identification of Dyslexia: Understanding the Issues

Purpose

The purpose of this tutorial is to provide an overview of the benefits and challenges associated with the early identification of dyslexia.

Method

The literature on the early identification of dyslexia is reviewed. Theoretical arguments and research evidence are summarized. An overview of response to intervention as a method of early identification is provided, and the benefits and challenges associated with it are discussed. Finally, the role of speech-language pathologists in the early identification process is addressed.

Conclusions

Early identification of dyslexia is crucial to ensure that children are able to maximize their educational potential, and speech-language pathologists are well placed to play a role in this process. However, early identification alone is not sufficient—difficulties with reading may persist or become apparent later in schooling. Therefore, continuing progress monitoring and access to suitable intervention programs are essential.

The effects of acute wild blueberry supplementation on the cognition of 7-10-year-old schoolchildren

Purpose

Previous evidence suggests consumption of flavonoids, a sub-class of polyphenols, is associated with improved cognitive function across the lifespan. In particular, acute intervention of a flavonoid-rich wild blueberry (WBB) drink has been shown to boost executive function (EF), short-term memory and mood 2–6 h post-consumption in 7–10-year-old children. However, confirmation of the aspects of EF and memory susceptible to WBB ingestion is required, particularly during childhood, a critical period of neurological development. In addition, the child literature on berry flavonoid supplementation and cognition highlights the potential for such interventions to elicit positive benefits to real-world educational scenarios, such as reading, a complex ability which relies upon aspects of cognition already known to improve following WBB.

Methods

Here we examined which aspects of EF and memory are susceptible to acute WBB, as well as investigating whether acute WBB could further benefit reading ability. Fifty-four healthy children, aged 7–10 years, consumed a 200 ml WBB drink (253 mg anthocyanins) or a matched placebo according to a randomised, single-blind, parallel-groups design. Verbal memory (Auditory Verbal Learning Task; AVLT), EF (Modified Attention Network Task; MANT), and reading efficiency (Test of Word Reading Efficiency-2; TOWRE-2) were assessed at baseline and 2 h post-consumption.

Results

For the MANT, significantly quicker RTs were observed for WBB participants when compared to placebo participants on 120 ms trials, without cost to accuracy. Furthermore, WBB participants showed enhanced verbal memory performance on the AVLT, recalling more words than placebo participants on short delay and memory acquisition measures post-consumption. Despite these significant improvements in cognitive performance, no significant effects were observed for reading measures.

Conclusion

Consumption of WBB was found to significantly improve memory and attentional aspects of EF. This indicates that a flavonoid-rich blueberry product, equivalent to 240 g or 1½ cups of fresh blueberries can provide acute cognitive benefits in children. These findings support accumulating evidence that flavonoid-rich products are beneficial for healthy brain function, particularly during critical developmental periods. However, the lack of findings relating to reading ability suggested acute WBB may not be sufficient to elicit benefits to reading. Chronic supplementation and other more sensitive reading measures should be considered for examining the effects of WBB on such a complex skill in the future.

Morphological effects in visual word recognition: Children, adolescents, and adults

The process by which morphologically complex words are recognized and stored is a matter of ongoing debate. A large body of evidence indicates that complex words are automatically decomposed during visual word recognition in adult readers. Research with developing readers is limited and findings are mixed. This study aimed to investigate morphological decomposition in visual word recognition using cross-sectional data. Participants (33 adults, 36 older adolescents [16 to 17 years], 37 younger adolescents [12 to 13 years], and 50 children [7 to 9 years]) completed a timed lexical-decision task comprising 120 items (60 nonwords and 60 real word fillers). Half the nonwords contained a real stem combined with a real suffix (pseudomorphemic nonwords, e.g., earist); the other half used the same stems combined with a nonmorphological ending (control nonwords, e.g., earilt). All age groups were less accurate in rejecting pseudomorphemic nonwords than control nonwords. Adults and older adolescents were also slower to reject pseudomorphemic nonwords compared with control nonwords, but this effect did not emerge for the younger age groups. These findings demonstrate that, like adults, children and adolescents are sensitive to morphological structure in online visual word processing, but that some important changes occur over the course of adolescence.

Meeting the educational and social needs of children with language impairment or autism spectrum disorder: the parents' perspectives

BACKGROUND

There is increasing interest in examining the perspectives of parents of children with special educational needs (SEN). Exploring the view of parents of a child with language impairment (LI) or autism spectrum disorder (ASD) is particularly important because of their high prevalence, at over 30% of children with SEN in England, and the increasing evidence of overlapping profiles of their needs.

AIMS

To examine the similarities and differences between the perspectives of parents of children with LI or ASD on three issues: (1) their child's educational progress, and their behavioural, emotional and social development; (2) the provision made to support their child's education and meet their SEN; and (3) their own involvement in decision-making about provision for their child.

METHODS & PROCEDURES

The parents of 129 children with LI (n = 76) or ASD (n = 53) were interviewed using a semi-structured protocol that gathered both quantitative data (parent ratings) and qualitative, in-depth explorations of their perspectives.

OUTCOMES & RESULTS

There were no significant differences between the perspectives of parents of children with LI and parents of children with ASD with respect to their child's educational progress; the provision made to meet their child's educational needs; or their involvement in decision-making during the statutory assessment procedure, including the determination of a statement of SEN, and the current provision made by their child's school. Both parent groups were generally positive about these but parents of children with ASD were more concerned about their child's peer relationships. Parents whose child attended a mainstream school with a specialist resource tended to be more positive about the provision made than parents whose child was included individually into a mainstream school.

CONCLUSIONS & IMPLICATIONS

Although previous research indicates that parents of children with ASD are overrepresented among those who express dissatisfaction with the provision made to meet their child's needs, this study indicates high levels of satisfaction and overlap between the perspectives of parents of children with LI or ASD regarding their child's educational progress and their own involvement in decision-making about the child's provision. The findings indicate the importance for policy and practice of focusing on identified needs rather than diagnostic category; and the importance of practitioners and administrators engaging meaningfully with parents in collaborative decision-making.

Evidence for semantic involvement in regular and exception word reading in emergent readers of English

We investigated the relationship between semantic knowledge and word reading. A sample of 27 6-year-old children read words both in isolation and in context. Lexical knowledge was assessed using general and item-specific tasks. General semantic knowledge was measured using standardized tasks in which children defined words and made judgments about the relationships between words. Item-specific knowledge of to-be-read words was assessed using auditory lexical decision (lexical phonology) and definitions (semantic) tasks. Regressions and mixed-effects models indicated a close relationship between semantic knowledge (but not lexical phonology) and both regular and exception word reading. Thus, during the early stages of learning to read, semantic knowledge may support word reading irrespective of regularity. Contextual support particularly benefitted reading of exception words. We found evidence that lexical-semantic knowledge and context make separable contributions to word reading.

The radiological diagnosis of frontotemporal dementia in everyday practice: an audit of reports, review of diagnostic criteria, and proposal for service improvement

AIM

To investigate how commonly valuable diagnostic information regarding the frontotemporal dementias (FTDs) may be missed on routine radiological reporting.

MATERIALS AND METHODS

The magnetic resonance imaging (MRI) examination results of a series of 39 consecutive patients in whom the diagnosis was initially thought to be a form of FTD were audited. Twenty-two patients satisfied formal diagnostic criteria for subtypes of FTD. The initial non-specialist radiological reports of the MRI examinations were compared with those of a radiologist who specifically examined the images for the possibility of atypical dementia.

RESULTS

Six of the 22 original reports provided a full and accurate description of the radiological findings, while two provided a fully accurate interpretation.

CONCLUSION

Valuable diagnostic information may be missed unless clinicians and radiologists jointly review and discuss brain imaging in cases of dementia. The use of standardised scales may enhance the reporting of MRI examinations for dementia.

How Word Meaning Influences Word Reading

Understanding how we read is a fundamental question for psychology, with critical implications for education. Studies of word reading tend to focus on the mappings between the written and spoken forms of words. In this article, we review evidence from developmental, neuroimaging, neuropsychological, and computational studies that show that knowledge of word meanings is inextricably involved in word reading. Consequently, models of reading must better specify the role of meaning in skilled reading and its acquisition. Further, our review paves the way for educationally realistic research to confirm whether explicit teaching of oral vocabulary improves word reading.

Emotional and behavioural problems in children with language impairments and children with autism spectrum disorders

BACKGROUND

Although it is well-established that children with language impairment (LI) and children with autism spectrum disorders (ASD) both show elevated levels of emotional and behavioural problems, the level and types of difficulties across the two groups have not previously been directly compared.

AIMS

To compare levels of emotional and behavioural problems in children with LI and children with ASD recruited from the same mainstream schools.

METHODS & PROCEDURES

We measured teacher-reported emotional and behavioural problems using the Strengths and Difficulties Questionnaire (SDQ) in a sample of 5-13-year-old children with LI (N = 62) and children with ASD (N = 42) attending mainstream school but with identified special educational needs.

OUTCOMES & RESULTS

Both groups showed similarly elevated levels of emotional, conduct and hyperactivity problems. The only differences between the LI and ASD groups were on subscales assessing peer problems (which were higher in the ASD group) and prosocial behaviours (which were higher in the LI group). Overall, there were few associations between emotional and behavioural problems and child characteristics, reflecting the pervasive nature of these difficulties in children with LI and children with ASD, although levels of problems were higher in children with ASD with lower language ability. However, in the ASD group only, a measure of family social economic status was associated with language ability and attenuated the association between language ability and emotional and behavioural problems.

CONCLUSIONS & IMPLICATIONS

Children with LI and children with ASD in mainstream school show similarly elevated levels of emotional and behavioural problems, which require monitoring and may benefit from intervention. Further work is required to identify the child, family and situational factors that place children with LI and children with ASD at risk of emotional and behavioural problems, and whether these differ between the two groups. This work can then guide the application of evidence-based interventions to these children.

Educational attainment in poor comprehenders

To date, only one study has investigated educational attainment in poor (reading) comprehenders, providing evidence of poor performance on national UK school tests at age 11 years relative to peers (Cain and Oakhill, 2006). In the present study, we adopted a longitudinal approach, tracking attainment on such tests from 11 years to the end of compulsory schooling in the UK (age 16 years). We aimed to investigate the proposal that educational weaknesses (defined as poor performance on national assessments) might become more pronounced over time, as the curriculum places increasing demands on reading comprehension. Participants comprised 15 poor comprehenders and 15 controls; groups were matched for chronological age, nonverbal reasoning ability and decoding skill. Children were identified at age 9 years using standardized measures of nonverbal reasoning, decoding and reading comprehension. These measures, along with a measure of oral vocabulary knowledge, were repeated at age 11 years. Data on educational attainment were collected from all participants (n = 30) at age 11 and from a subgroup (n = 21) at 16 years. Compared to controls, educational attainment in poor comprehenders was lower at ages 11 and 16 years, an effect that was significant at 11 years. When poor comprehenders were compared to national performance levels, they showed significantly lower performance at both time points. Low educational attainment was not evident for all poor comprehenders. Nonetheless, our findings point to a link between reading comprehension difficulties in mid to late childhood and poor educational outcomes at ages 11 and 16 years. At these ages, pupils in the UK are making key transitions: they move from primary to secondary schools at 11, and out of compulsory schooling at 16.

Reading comprehension in autism spectrum disorders: the role of oral language and social functioning

Reading comprehension is an area of difficulty for many individuals with autism spectrum disorders (ASD). According to the Simple View of Reading, word recognition and oral language are both important determinants of reading comprehension ability. We provide a novel test of this model in 100 adolescents with ASD of varying intellectual ability. Further, we explore whether reading comprehension is additionally influenced by individual differences in social behaviour and social cognition in ASD. Adolescents with ASD aged 14-16 years completed assessments indexing word recognition, oral language, reading comprehension, social behaviour and social cognition. Regression analyses show that both word recognition and oral language explain unique variance in reading comprehension. Further, measures of social behaviour and social cognition predict reading comprehension after controlling for the variance explained by word recognition and oral language. This indicates that word recognition, oral language and social impairments may constrain reading comprehension in ASD.

Research review: reading comprehension in developmental disorders of language and communication

BACKGROUND

Deficits in reading airment (SLI), Down syndrome (DS) and autism spectrum disorders (ASD).

METHODS

In this review (based on a search of the ISI Web of Knowledge database to 2011), the Simple View of Reading is used as a framework for considering reading comprehension in these groups.

CONCLUSIONS

There is substantial evidence for reading comprehension impairments in SLI and growing evidence that weaknesses in this domain are common in DS and ASD. Further, in these groups reading comprehension is typically more impaired than word recognition. However, there is also evidence that some children and adolescents with DS, ASD and a history of SLI develop reading comprehension and word recognition skills at or above the age appropriate level. This review of the literature indicates that factors including word recognition, oral language, nonverbal ability and working memory may explain reading comprehension difficulties in SLI, DS and ASD. In addition, it highlights methodological issues, implications of poor reading comprehension and fruitful areas for future research.

Orthographic Facilitation in Oral Vocabulary Acquisition

An experiment investigated whether exposure to orthography facilitates oral vocabulary learning. A total of 58 typically developing children aged 8–9 years were taught 12 nonwords. Children were trained to associate novel phonological forms with pictures of novel objects. Pictures were used as referents to represent novel word meanings. For half of the nonwords children were additionally exposed to orthography, although they were not alerted to its presence, nor were they instructed to use it. After this training phase a nonword–picture matching posttest was used to assess learning of nonword meaning, and a spelling posttest was used to assess learning of nonword orthography. Children showed robust learning for novel spelling patterns after incidental exposure to orthography. Further, we observed stronger learning for nonword–referent pairings trained with orthography. The degree of orthographic facilitation observed in posttests was related to children's reading levels, with more advanced readers showing more benefit from the presence of orthography.

Amount and type of dietary fat regulate pancreatic lipase gene expression in rats

Both amount and type of dietary triglycerides regulate pancreatic lipase, but the mechanism is not fully understood. This study investigated the effects of type (safflower oil and lard) and amount [low (50 g/kg diet) or moderate (174 g/kg diet)] of fat on rat pancreatic lipase (rPL) activity and mRNA levels. Polyunsaturated safflower oil resulted in 80% greater lipase activity compared with the saturated lard at moderate levels, whereas safflower oil resulted in 50% lower lipase activity compared with lard at low levels. The rPL-3 mRNA levels were greater in rats fed the moderate safflower oil diet (163%) or the moderate lard diet (212%) than in those fed the respective low fat diets and were 45% greater in those fed safflower oil than in those fed lard. The rPL-1 mRNA levels were greater in rats fed moderate safflower oil (50%) or lard (135%) than in those fed the respective low fat diet, but these levels were not affected by type of fat, in contrast to rPL-3 mRNA levels. The amount of fat independent of its type regulates pancreatic lipase pre-translationally, because increasing dietary saturated or polyunsaturated fat resulted in parallel changes in rPL-3 and rPL-1 mRNA levels. However, type of fat may regulate pancreatic lipase at other levels such as translational or post-translational, because the 212% increase in rPL-3 mRNA in rats fed the moderate lard diet compared with the low lard diet did not result in greater pancreatic lipase activity.

In vitro evaluation of gallstone dissolution with methyl-tert-butyl ether and ultrasound energy

Given the large number of cholecystectomies performed annually, a nonsurgical approach to gallstone therapy is of great interest. A laboratory ultrasound system has been developed to study enhancement of methyl-tert-butyl ether (MTBE) dissolution of human gallstones in vitro. A mathematical model that quantitatively characterizes the dissolution process via a rate constant has been developed. Using this model, the kinetics of 15 gallstones from a single patient were evaluated for three dissolution methods: 1) unstirred MTBE, 2) aspirated MTBE, and 3) ultrasonically enhanced MTBE. The results showed excellent fits between the model and measured dissolution rates. 195 kHz continuous-wave (CW) ultrasonically enhanced dissolution rates exhibited a 6.2 fold gain over the manually aspirated MTBE and a 49.5 fold gain over static MTBE dissolution. Investigation of 50% duty cycle pulsed mode ultrasound revealed that total power appears to be the determinant of the observed dissolution rates. Gallstone calcification showed a strong correlation with dissolution rates measured by the model.

Accelerated gallstone dissolution in methyl tert-butyl ether by sonication. An in vitro study

OBJECTIVES

The authors tested the effect of 195 KHz therapeutic ultrasound energy on gallstone dissolution in concert with methyl tert-butyl ether (MTBE) in vitro.

METHODS

Sixteen sets of three gallstones matched for weight and appearance were selected from 16 surgically resected human gallbladders. One stone from each set was analyzed for its density pattern by computed tomography (CT) and biochemically for cholesterol content. Based on CT appearance, the stones were classified into eight noncalcified, four partially calcified, and four heavily calcified sets. The three stones were subjected to dissolution with MTBE: one with simultaneous sonication via an experimental ultrasound unit, one with manual stirring, and one acted as control without added treatment.

RESULTS

Sonication reduced the dissolution time of noncalcified stones by 96% (range, 94%-98%; standard deviation [SD], 2%) relative to controls, and it was three to four times more effective than manual stirring. It was similarly effective in helping to dissolve partially calcified stones, but not heavily calcified stones.

CONCLUSIONS

This study demonstrates the positive effect of sonication in accelerating gallstone dissolution with MTBE in vitro for stones without heavy calcification.