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1.
Hautarzt ; 71(9): 677-685, 2020 Sep.
Article in German | MEDLINE | ID: mdl-32710130

ABSTRACT

BACKGROUND: In recent years, many medical specialties with a visual focus have been revolutionized by image analysis algorithms using artificial intelligence (AI). As dermatology belongs to this field, it has the potential to play a pioneering role in the use of AI. OBJECTIVE: The current use of AI for the diagnosis and follow-up of dermatoses is reviewed and the future potential of these technologies is discussed. MATERIALS AND METHODS: This article is based on a selective review of the literature using Embase and MEDLINE and the keywords "psoriasis", "eczema", "dermatoses" and "acne" combined with "artificial intelligence", "machine learning", "deep learning", "neural network", "computer-guided", "supervised machine learning" or "unsupervised machine learning" were searched. RESULTS: In comparison to examiner-dependent intra- and interindividually fluctuating scores for the assessment of inflammatory dermatoses (e.g. the Psoriasis Areas Severity Index [PASI] and body surface area [BSA]), AI-based algorithms can potentially offer reproducible, standardized evaluations of these scores. Whereas promising algorithms have already been developed for the diagnosis of psoriasis, there is currently only scarce work on the use of AI in the context of eczema. CONCLUSIONS: The latest developments in this field show the enormous potential of AI-based diagnostics and follow-up of dermatological clinical pictures by means of an autonomous computer-based image analysis. These noninvasive, optical examination methods provide valuable additional information, but dermatological interaction remains indispensable in daily clinical practice.


Subject(s)
Artificial Intelligence , Neural Networks, Computer , Skin Diseases/diagnosis , Skin Diseases/therapy , Deep Learning , Humans , Machine Learning
2.
Mol Cell Probes ; 29(5): 323-9, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26050939

ABSTRACT

We evaluated a multiple consanguineous Turkish family with two children, a boy and a girl, affected by severe encephalopathy, hypotonia, microcephaly and retinal dystrophy by a combination of linkage analysis and Whole Exome Sequencing (WES). We analyzed the sequence data by two different bioinformatics pipelines which did not differ in overall processing strategy but involved differences in software used, minor allele frequency (MAF) thresholds and reference data sets, the usage of in-house control exomes and filter settings to prioritize called variants. Assuming autosomal recessive mode of inheritance, only homozygous variants present in both children were considered. The resulting variant lists differed partially (nine variants identified by both pipelines, ten variants by only one pipeline). Major reasons for this discrepancy were different filters for MAF and different variant prioritizations. Combining the variant lists with the results of linkage analysis and further prioritization by expression data and prediction tools, an intronic homozygous splice variant (c.1090-2A>G; IVS9-2A>G; p.?) in PGAP1 (Post-GPI Attachment To Proteins 1) was identified and validated by cDNA analysis. PGAP1 ensures the first step of maturation of GPI (glycosylphosphatidylinositol)-anchor proteins. Recently, a homozygous loss-of-function mutation in PGAP1 has been reported in one family with two children affected by a similar phenotype. The present report not only illustrates the possible influence of specific filtering settings on the results of WES but also confirms PGAP1 as a cause of severe encephalopathy.


Subject(s)
Brain Diseases/genetics , Genetic Linkage , Membrane Proteins/genetics , Mutation , Phosphoric Monoester Hydrolases/genetics , Sequence Analysis, DNA/methods , Computational Biology/methods , Consanguinity , Exome , Female , Genetic Predisposition to Disease , Homozygote , Humans , Male , Pedigree , Turkey
3.
Am J Public Health ; 104 Suppl 4: S548-54, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25100420

ABSTRACT

OBJECTIVES: We conducted an exploratory study to determine what organizational characteristics predict the provision of culturally competent services for American Indian and Alaska Native (AI/AN) veterans in Department of Veterans Affairs (VA) health facilities. METHODS: In 2011 to 2012, we adapted the Organizational Readiness to Change Assessment (ORCA) for a survey of 27 VA facilities in the Western Region to assess organizational readiness and capacity to adopt and implement native-specific services and to profile the availability of AI/AN veteran programs and interest in and resources for such programs. RESULTS: Several ORCA subscales (Program Needs, Leader's Practices, and Communication) statistically significantly predicted whether VA staff perceived that their facilities were meeting the needs of AI/AN veterans. However, none predicted greater implementation of native-specific services. CONCLUSIONS: Our findings may aid in developing strategies for adopting and implementing promising native-specific programs and services for AI/AN veterans, and may be generalizable for other veteran groups.


Subject(s)
Cultural Competency , Indians, North American , Inuit , United States Department of Veterans Affairs/organization & administration , Veterans , Communication , Health Services Accessibility/organization & administration , Health Services Needs and Demand , Humans , Leadership , Organizational Innovation , Program Evaluation , United States , Veterans Health
4.
J Community Health ; 39(5): 990-6, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24585103

ABSTRACT

American Indians and Alaska Natives serve at the highest rate of any US race or ethnic group, yet are the most underserved population of Veterans and do not take advantage of the Department of Veterans Affairs (VA) benefits and services. Barriers to seeking care include stigma, especially for mental health issues; distance to care; and lack of awareness of benefits and services they are entitled to receive. In response to this underutilization of the VA, an innovative program--the Tribal Veterans Representative (TVR) program--was developed within the VA to work with American Indians and Alaska Natives in rural and remote areas. The TVR goes through extensive training every year; is a volunteer, a Veteran and tribal community member who seeks out unenrolled Native Veterans, provides them with information on VA health care services and benefits, and assists them with enrollment paperwork. Being from the community they serve, these outreach workers are able to develop relationships and build rapport and trust with fellow Veterans. In place for over a decade in Montana, this program has enrolled a countless number of Veterans, benefiting not only the individual, but their family and the community as well. Also resulting from this program, are the implementation of Telemental Health Clinics treating Veterans with PTSD, a transportation program helping Veterans get to and from distant VA facilities, a Veteran Resource Center, and a Veteran Tribal Clinic. This program has successfully trained over 800 TVRs, expanded to other parts of the country and into remote areas of Alaska.


Subject(s)
Community Health Workers/education , Community-Institutional Relations , Indians, North American/statistics & numerical data , United States Department of Veterans Affairs/statistics & numerical data , United States Indian Health Service/statistics & numerical data , Humans , Montana/epidemiology , United States , United States Department of Veterans Affairs/organization & administration , United States Indian Health Service/organization & administration
5.
Front Psychol ; 4: 480, 2013.
Article in English | MEDLINE | ID: mdl-23935585

ABSTRACT

In early numerical development, children have to become familiar with the Arabic number system and its place-value structure. The present review summarizes and discusses evidence for language influences on the acquisition of the highly transparent structuring principles of digital-Arabic digits by means of its moderation through the transparency of the respective language's number word system. In particular, the so-called inversion property (i.e., 24 named as "four and twenty" instead of "twenty four") was found to influence number processing in children not only in verbal but also in non-verbal numerical tasks. Additionally, there is first evidence suggesting that inversion-related difficulties may influence numerical processing longitudinally. Generally, language-specific influences in children's numerical development are most pronounced for multi-digit numbers. Yet, there is currently only one study on three-digit number processing for German-speaking children. A direct comparison of additional new data from Italian-speaking children further corroborates the assumption that language impacts on cognitive (number) processing as inversion-related interference was found most pronounced for German-speaking children. In sum, we conclude that numerical development may not be language-specific but seems to be moderated by language.

6.
J Rural Health ; 29(3): 304-10, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23802932

ABSTRACT

PURPOSE: The Department of Veterans Affairs (VA) and the Indian Health Service (IHS) signed a Memo of Understanding in 2010 to strengthen their partnership in improving health care services for Native veterans, who are disproportionately rural. This paper describes the demographic and service use profile of rural Native veterans who access VA health care. METHODS: Data were abstracted from the 2008 Veteran Health Administration (VHA) medical dataset, and the characteristics of rural Native veterans were compared to rural non-Native veterans. FINDINGS: Rural Native veterans were more rural (41% vs 35%) and more highly rural (8% vs 2%) compared to non-Native veterans. Rural Native veterans were younger, more likely to be female, and earned about the same median income compared to rural non-Native veterans. Although rural Native veterans had fewer diagnoses on average, they were more likely to have served in combat areas and to have higher levels of service-connected disability compared to other rural veterans. CONCLUSIONS: Demographic and service-related characteristics of rural Native veterans who accessed VA care differ from those of rural non-Native veterans. Identifying specific health care and service use characteristics will assist in the development of appropriate policy and programs to serve rural Native veterans.


Subject(s)
Indians, North American/statistics & numerical data , Rural Population/statistics & numerical data , United States Department of Veterans Affairs , United States Indian Health Service/statistics & numerical data , Veterans/statistics & numerical data , Adult , Aged , Databases, Factual , Female , Humans , Male , Middle Aged , United States
7.
J Hand Surg Eur Vol ; 38(5): 524-9, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23186862

ABSTRACT

The purpose of this study was to assess the association between arm-specific disability measured with the QuickDASH questionaire and radiological criteria in patients with extra-articular distal radial fractures. A consecutive series of 385 patients were initially treated non-operatively for an extra-articular distal radial fracture and 257 (69 %) patients were included in the study. In 203 of these patients (78%) the quality of radiographic reduction was judged to be adequate by radiological parameters, which included dorsal tilt, radial inclination, and radial shortening. In 54 patients (22%) the quality of radiographic alignment was judged to be inadequate. We observed no effect of radiographic parameters on the functional outcome. Female sex and longer duration of follow-up (>35 months) were the only independent prognostic factors significantly associated with a worse QuickDASH score.


Subject(s)
Radius Fractures/diagnostic imaging , Radius Fractures/therapy , Aged , Disability Evaluation , Female , Fracture Healing , Humans , Male , Middle Aged , Prognosis , Radiography , Recovery of Function , Retrospective Studies , Risk Factors , Surveys and Questionnaires
8.
J Hum Hypertens ; 27(1): 51-5, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22129610

ABSTRACT

Riley Day syndrome, commonly referred to as familial dysautonomia (FD), is a genetic disease with extremely labile blood pressure owing to baroreflex deafferenation. Chronic renal disease is very frequent in these patients and was attributed to recurrent arterial hypotension and renal hypoperfusion. Aggressive treatment of hypotension, however, has not reduced its prevalence. We evaluated the frequency of kidney malformations as well as the impact of hypertension, hypotension and blood pressure variability on the severity of renal impairment. We also investigated the effect of fludrocortisone treatment on the progression of renal disease. Patients with FD appeared to have an increased incidence of hydronephrosis/reflux and patterning defects. Patients <4 years old had hypertension and normal estimated glomerular filtration rates (eGFR). Patients with more severe hypertension and greater variability in their blood pressure had worse renal function (both, P<0.01). In contrast, there was no relationship between eGFR and the lowest blood pressure recorded during upright tilt. The progression of renal disease was faster in patients receiving fludrocortisone (P<0.02). Hypertension precedes kidney disease in these patients. Moreover, increased blood pressure variability as well as mineralocorticoid treatment accelerate the progression of renal disease. No association was found between hypotension and renal disease in patients with FD.


Subject(s)
Blood Pressure , Dysautonomia, Familial/complications , Kidney/abnormalities , Renal Insufficiency, Chronic/etiology , Adult , Disease Progression , Dysautonomia, Familial/physiopathology , Female , Fludrocortisone/adverse effects , Glomerular Filtration Rate , Humans , Male
9.
Psychiatr Serv ; 63(2): 179-81, 2012 Feb 01.
Article in English | MEDLINE | ID: mdl-22302338

ABSTRACT

OBJECTIVE: This study examined use by American Indian and Alaska Native veterans of services provided by specialty telemental health clinics focused on posttraumatic stress disorder. These clinics offer services via videoconferencing to address challenges faced by rural veterans in accessing care. METHODS: A retrospective chart and electronic medical record review was conducted for 85 male veterans who used services at two rural telemental health clinics from 2001 through 2006. Service use and other characteristics were documented before and after their initial telemental health intake. RESULTS: After intake, patients' use of any health services (both general medical and mental health services) significantly increased (p<.01), as did the proportion receiving psychotropic medication (p<.01). CONCLUSIONS: This first examination of service use by American Indian and Alaska Native veterans at specialty telemental health clinics will help inform research and clinical strategies for improving telemental health for this and other rural populations.


Subject(s)
Indians, North American/psychology , Mental Health Services/statistics & numerical data , Stress Disorders, Post-Traumatic/therapy , Telemedicine/statistics & numerical data , Veterans/statistics & numerical data , Adult , Aged , Aged, 80 and over , Humans , Indians, North American/statistics & numerical data , Male , Middle Aged , Patient Acceptance of Health Care/ethnology , Patient Acceptance of Health Care/statistics & numerical data , Retrospective Studies , Rural Health , Stress Disorders, Post-Traumatic/epidemiology , Stress Disorders, Post-Traumatic/ethnology , Telemedicine/organization & administration , United States/epidemiology , Videoconferencing
10.
Telemed J E Health ; 18(2): 87-94, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22283396

ABSTRACT

Rural American Indian veterans have unique healthcare needs and face numerous barriers to accessing healthcare services. Over the past decade, the Department of Veterans Affairs in conjunction with the University of Colorado Denver has turned to the promising field of telemental health to develop a series of videoconferencing-based clinics to reach this vulnerable population and improve mental healthcare services. The ongoing development, implementation, and expansion of these clinics have been assessed as part of a program improvement. The outcomes of these assessments have been documented in a series of published articles, controlled studies, program and case reports, and model descriptions. This article summarizes a decade of experience with the American Indian Telemental Health Clinics, the clinic model, and the literature arising from these clinics and presents lessons learned while establishing, maintaining, and evaluating these clinics. The ability to tailor the clinics to individual sites and cultures and to provide various services has been critical to the operation of the clinics. Culturally specific care through culturally knowledgeable providers, onsite tribal outreach workers, and collaboration with community services has proven essential in operating the clinics, as well as building rapport, trust, and engagement with the target patient population. It is hoped that the lessons learned and practices presented here can not only assist others working to improve the care for rural Native veterans but also serve as a model in the use of telemental health services for improving care and access to rural veteran and non-veteran populations.


Subject(s)
Indians, North American/psychology , Psychiatry/organization & administration , Telemedicine/organization & administration , Veterans/psychology , Health Services Needs and Demand , Humans , Mental Health Services/organization & administration , Program Evaluation , United States
11.
J Anim Physiol Anim Nutr (Berl) ; 96(2): 228-36, 2012 Apr.
Article in English | MEDLINE | ID: mdl-21453349

ABSTRACT

Grass may have a differential impact on the metabolism of the dairy cow, depending on the grazing system applied. In this study, the hypothesis was tested that metabolism of grazed vs. zero-grazed dairy cows is differently regulated throughout the vegetation period. The study included three experimental periods (p1, p2 and p3) of 14 days each, and two treatments [grazing from pasture, PASTURE, n = 9; or zero-grazing in a free-stall barn (BARN, n = 9)]. Blood and liver samples were collected at the end of each period when the cows were on average 64, 120 and 197 DIM. Concentrations of metabolites and hormones, and activities of various enzymes were determined in plasma. Liver samples were measured for mRNA abundance of genes encoding enzymes and nuclear receptors involved in metabolic pathways. PASTURE cows had higher plasma concentrations of T(3), BHB, and total protein than BARN cows across periods (p < 0.05). BARN cows had higher concentrations of NEFA (in p1) and urea (in p1 and p2) in relation PASTURE cows (p < 0.05), and had higher mRNA abundance of liver-X-receptor-α and glycerol-3-phosphate-acyltransferase across periods (p < 0.05). The results confirm the hypothesis that metabolism is different between BARN and PASTURE cows throughout the vegetation period, and show that the observed differences are mainly reflected in parameters of lipid metabolism.


Subject(s)
Animal Feed/analysis , Animal Husbandry/methods , Cattle/blood , Cattle/physiology , Liver/metabolism , Seasons , Animal Nutritional Physiological Phenomena , Animals , Carbohydrate Metabolism/physiology , Dairying , Diet/veterinary , Energy Metabolism/physiology
12.
Res Dev Disabil ; 32(6): 2683-9, 2011.
Article in English | MEDLINE | ID: mdl-21763104

ABSTRACT

Comparing numerical performance between different languages does not only mean comparing different number-word systems, but also implies a comparison of differences regarding culture or educational systems. The Czech language provides the remarkable opportunity to disentangle this confound as there exist two different number-word systems within the same language: for instance, "25" can be either coded in non-inverted order "dvadsetpät" [twenty-five] or in inverted order "pätadvadset" [five-and-twenty]. To investigate the influence of the number-word system on basic numerical processing within one culture, 7-year-old Czech-speaking children had to perform a transcoding task (i.e., writing Arabic numbers to dictation) in both number-word systems. The observed error pattern clearly indicated that the structure of the number-word system determined transcoding performance reliably: In the inverted number-word system about half of all errors were inversion-related. In contrast, hardly any inversion-related errors occurred in the non-inverted number-word system. We conclude that the development of numerical cognition does not only depend on cultural or educational differences, but is indeed related to the structure and transparency of a given number-word system.


Subject(s)
Cognition , Cultural Characteristics , Language , Mathematics/education , Psycholinguistics , Child , Czech Republic , Female , Humans , Male , Memory, Short-Term , Semantics , Students/psychology
13.
Res Dev Disabil ; 32(5): 1837-51, 2011.
Article in English | MEDLINE | ID: mdl-21498043

ABSTRACT

It is assumed that basic numerical competencies are important building blocks for more complex arithmetic skills. The current study aimed at evaluating this interrelation in a longitudinal approach. It was investigated whether first graders' performance in basic numerical tasks in general as well as specific processes involved (e.g., place-value understanding) reliably predicted performance in an addition task in third grade. The results indicated that early place-value understanding was a reliable predictor for specific aspects of arithmetic performance. Implications of the role of basic numerical competencies for the acquisition of complex arithmetic are discussed.


Subject(s)
Child Development , Mathematics/education , Mathematics/methods , Mental Processes , Students , Child , Educational Measurement , Female , Follow-Up Studies , Humans , Intelligence , Longitudinal Studies , Male , Memory, Short-Term , Regression Analysis
14.
J Dairy Sci ; 94(4): 1989-2000, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21426990

ABSTRACT

The objectives of the study were to assess the 13C bicarbonate dilution technique using an automatic blood sampling system and to use this technique to estimate energy expenditure (EE) based on the CO2 production of 14 lactating Holstein cows on pasture or in a freestall barn. The effects of physical activity and eating behavior on EE were also assessed. Cows were exposed to each feeding system in a crossover design with two 14-d experimental periods, each consisting of an adaptation period and a 7-d data collection period. Cows either grazed on pasture or had ad libitum access, in the freestall barn, to grass cut daily from the same paddock. All cows were supplemented with a cereal-based concentrate. The EE of each cow was determined from 0700 to 1300 h on 1 d of each collection period. Blood samples for the 13C bicarbonate dilution technique were taken either manually in the barn or using an automatic blood sampling system on pasture. Eating pattern and physical activity were recorded from 0700 to 1300 h using a behavior recorder and an activity meter, respectively. Milk yield was recorded daily. Individual feed intake was estimated using the alkane double-indicator technique. Two preceding experiments confirmed that the sampling technique (manual or automatic) and the following storage of the blood samples (frozen directly after withdrawal or first cooled on ice and then frozen 6 h later) had no effect on 13CO2 enrichment in the extracted blood CO2 or on the subsequent calculation of CO2 production. During the 6-h measurement period, the EE of cows on pasture was higher than that of cows in the freestall barn. Daily feed intake and milk production were not affected by the feeding treatment. Grazing cows spent more time walking and less time standing and lying than did cows fed indoors. Time spent eating was greater and time spent ruminating was lower for cows on pasture compared with grass-fed cows in the barn. In conclusion, the 13C bicarbonate dilution technique, combined with an automatic blood sampling system, is a suitable method to determine the EE of lactating dairy cows on pasture. Positive correlations between EE and walking and eating time indicate that the higher energy requirements of dairy cows on pasture may be at least partly caused by a higher level of physical activity. However, before specific recommendations about additional energy supply can be given, it must be determined whether EE measured over 6 h can be extrapolated to 24 h. Furthermore, the apparent inconsistency between EE, feed intake, and milk production needs to be resolved.


Subject(s)
Blood Specimen Collection/veterinary , Cattle/physiology , Dairying/methods , Energy Metabolism/physiology , Feeding Methods/veterinary , Poaceae/metabolism , Animal Nutritional Physiological Phenomena , Animals , Automation , Blood Specimen Collection/instrumentation , Blood Specimen Collection/methods , Carbon Dioxide/blood , Cattle/blood , Cattle/metabolism , Cross-Over Studies , Feeding Behavior/physiology , Female , Lactation/physiology , Motor Activity/physiology
15.
J Exp Child Psychol ; 108(2): 371-82, 2011 Feb.
Article in English | MEDLINE | ID: mdl-21035126

ABSTRACT

The unit-decade compatibility effect is interpreted to reflect processes of place value integration in two-digit number magnitude comparisons. The current study aimed at elucidating the influence of language properties on the compatibility effect of Arabic two-digit numbers in Austrian, Italian, and Czech first graders. The number word systems of the three countries differ with respect to their correspondence between name and place value systems; the German language is characterized by its inversion of the order of tens and units in number words as compared with digital notations, whereas Italian number words are generally not inverted and there are both forms for Czech number words. Interestingly, the German-speaking children showed the most pronounced compatibility effect with respect to both accuracy and speed. We interpret our results as evidence for a detrimental influence of an intransparent number word system place value processing. The data corroborate a weak Whorfian hypothesis in children, with even nonverbal Arabic number processing seeming to be influenced by linguistic properties in children.


Subject(s)
Cross-Cultural Comparison , Language , Mathematics , Semantics , Austria , Child , Concept Formation , Czech Republic , Female , Humans , Italy , Male , Problem Solving , Psycholinguistics , Reaction Time , Symbolism
16.
J Med Genet ; 47(5): 312-20, 2010 May.
Article in English | MEDLINE | ID: mdl-19897463

ABSTRACT

BACKGROUND: Williams-Beuren syndrome (WBS) is a developmental disorder with multisystemic manifestations mainly characterised by vascular stenoses, distinctive craniofacial features, mental retardation with a characteristic neurocognitive profile, and some endocrine and connective tissue abnormalities, caused by a recurrent deletion of 1.55 Mb including 26-28 genes at chromosomal region 7q11.23. The analysis of clinical-molecular correlations in a few reported atypical patients has been useful to propose several deleted genes as main contributors to specific aspects of the WBS phenotype. PATIENTS AND METHODS: Two additional families with partial phenotypes and atypical 7q11.23 deletions were studied. Deletions were precisely defined at the nucleotide level, and the expression levels of some affected and flanking genes were assessed in lymphoblastoid cell lines. RESULTS: Affected individuals presented variable cardiovascular and connective tissue manifestations, subtle craniofacial features, normal visuospatial construction abilities with low average IQ and no endocrine abnormalities. The deletion in family NW1 encompassed 817 kb with 11 genes (CLDN3-GTF2IRD1), and 610 kb with 14 genes (VPS37D-RFC2) in family NW2. All deleted genes in typical and atypical deletions revealed low expression levels in lymphoblastoid cell lines, except for GTF2IRD1. CLIP2 was also underexpressed in all patients despite being outside the deletion in NW2, while no other flanking non-deleted gene showed significantly different expression compared to controls. CONCLUSIONS: Along with previously reported cases, clinical-molecular correlations in these two families further confirm that the functional hemizygosity for the GTF2I and GTF2IRD1 genes is the main cause of the neurocognitive profile and some aspects of the gestalt phenotype of WBS.


Subject(s)
Chromosome Deletion , Chromosomes, Human, Pair 7/genetics , Muscle Proteins/genetics , Nuclear Proteins/genetics , Trans-Activators/genetics , Transcription Factors, TFII/genetics , Williams Syndrome/genetics , Adult , Cell Line , Craniofacial Abnormalities/genetics , Craniofacial Abnormalities/pathology , Female , Gene Deletion , Gene Expression , Genetic Association Studies , Humans , Infant , Male , Pedigree , Phenotype , Williams Syndrome/pathology , Williams Syndrome/psychology , Young Adult
17.
Neuroimage ; 25(3): 838-49, 2005 Apr 15.
Article in English | MEDLINE | ID: mdl-15808984

ABSTRACT

The present fMRI study investigates, first, whether learning new arithmetic operations is reflected by changing cerebral activation patterns, and second, whether different learning methods lead to differential modifications of brain activation. In a controlled design, subjects were trained over a week on two new complex arithmetic operations, one operation trained by the application of back-up strategies, i.e., a sequence of arithmetic operations, the other by drill, i.e., by learning the association between the operands and the result. In the following fMRI session, new untrained items, items trained by strategy and items trained by drill, were assessed using an event-related design. Untrained items as compared to trained showed large bilateral parietal activations, with the focus of activation along the right intraparietal sulcus. Further foci of activation were found in both inferior frontal gyri. The reverse contrast, trained vs. untrained, showed a more focused activation pattern with activation in both angular gyri. As suggested by the specific activation patterns, newly acquired expertise was implemented in previously existing networks of arithmetic processing and memory. Comparisons between drill and strategy conditions suggest that successful retrieval was associated with different brain activation patterns reflecting the underlying learning methods. While the drill condition more strongly activated medial parietal regions extending to the left angular gyrus, the strategy condition was associated to the activation of the precuneus which may be accounted for by visual imagery in memory retrieval.


Subject(s)
Dominance, Cerebral/physiology , Frontal Lobe/physiology , Image Processing, Computer-Assisted , Imaging, Three-Dimensional , Learning/physiology , Magnetic Resonance Imaging , Mathematics , Parietal Lobe/physiology , Practice, Psychological , Problem Solving/physiology , Adult , Algorithms , Brain Mapping , Female , Humans , Male , Reaction Time/physiology , Retention, Psychology/physiology , Transfer, Psychology
20.
Eur J Surg ; 165(7): 659-64, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10452260

ABSTRACT

OBJECTIVE: To assess the efficacy of monoclonal antibody (MoAb) B72.3 for in vivo-immunoscintigraphy of pancreatic carcinoma in nude mice. DESIGN: Experimental controlled animal study. SETTING: University hospital, The Netherlands. SUBJECTS: 11 nude mice with subcutaneously xenografted human pancreatic carcinoma. INTERVENTIONS: Specific MoAb B72.3 and non-specific MoAb MOPC21 were iodinated with 131I and injected intraperitoneally in nude mice. Scintigrams were taken on days 1-10 and tumour:non-tumour ratios of the regions of interest (tumour, thorax, abdomen, background) were calculated. The mice were then killed for in vitro tissue counts. MAIN OUTCOME MEASURES: Tumour:non-tumour ratios in vivo and in vitro. RESULTS: Results of immunoscintigraphy on days 1, 2, and 6 were compared. In the B72.3-group all ratios were only moderately raised, the tumour:background ratio being the highest (2.35 (SD 0.67)) on day 6. There were no obvious differences between the ratios of the B72.3-group and the MOPC21-group. The results of tissue counts done at the end of the study, showed that tumour:non-tumour ratios were twice as high in the B72.3-group, suggesting some specificity of this MoAb. CONCLUSION: The results of our study suggest that MoAb B72.3 is not powerful enough for in vivo detection of pancreatic cancer as assessed in this xenograft model in nude mice.


Subject(s)
Adenocarcinoma/diagnostic imaging , Antibodies, Monoclonal , Antibodies, Neoplasm , Iodine Radioisotopes , Pancreatic Neoplasms/diagnostic imaging , Radioimmunodetection/methods , Animals , Antibody Specificity , Drug Evaluation, Preclinical , Gamma Cameras , Humans , Mice , Mice, Nude , Neoplasm Transplantation , Radioimmunodetection/statistics & numerical data , Statistics, Nonparametric , Time Factors , Transplantation, Heterologous
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