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Biomedical subjects

M A Restrepo

Publications and source records attributed to M A Restrepo.

12 recordsLinked to original sources
PubMed2001

Article use in Spanish-speaking children with specific language impairment.

The current study analysed article use in Spanish-speaking children with specific language impairment who are learning English as a second language. The surface hypothesis account of specific language impairment was evaluated in relation to the use of articles in these children. Language samples were obtained from 15 Spanish-speaking children with language impairment and 15 with normal language, ages 5;0 to 7;1, matched by age, gender, and school. The percentage of article errors was tested between groups with a nonparametric analysis and an analysis of covariance with mean length of terminable unit as the covariate. Results revealed significant differences between groups on percent of article errors with and without MLTU as the covariate. Nonparametric statistics on percent of article error types indicated that most errors consisted of omissions and gender agreement substitutions. As predicted by the Surface Hypothesis, article errors were likely to occur in unstressed definite articles, suggesting that perceptual and prosodic processes have some impact on children's production of articles.

Child↗
PubMed1998

Identifiers of predominantly Spanish-speaking children with language impairment.

The purpose of this study was to identify a set of measures that would discriminate 31 predominantly Spanish-speaking children with normal language (NL children) from 31 children with language impairment (LI children). The LI children were identified as such by experienced, bilingual (Spanish/English), ASHA-certified, speech-language pathologists who were currently seeing the children in their caseloads. Children ranged in age from 5 to 7 years and were matched for age, gender, and school. Additionally, nonverbal cognitive measures assured that they did not differ significantly intellectually. Measures of vocabulary, novel bound-morpheme learning skills, and language form were randomly administered to all children. Further, parents responded to questions about their perceptions of their children's speech and language skills and family history of speech and language problems. A stepwise discriminant analysis indicated that 4 measures discriminated the groups of children with a sensitivity of 91.3% and a specificity of 100% (p < .0001): parental report of the child's speech and language skills, number of errors per T-unit, mean length per T-unit, and family history of speech and language problems. A second discriminant analysis indicated that the sensitivity and specificity could be maintained when only the first 2 measures were included. Confirmatory discriminant analyses of the 2- and 4-measure models indicated that the discriminant accuracy was stable on an independent sample.

Child↗
PubMed1995

Effect of implicit and explicit "rule" presentation on bound-morpheme generalization in specific language impairment.

This study addressed whether generalization of a trained bound morpheme to untrained vocabulary stems differs between children with specific language impairment (SLI) and children with normal language (NL) under two controlled instructional conditions. Twenty-five children with NL and 25 children with SLI matched for age served as subjects. Contrasts between affixed and unaffixed words highlighted the affixation "rule" in the "implicit-rule" condition. The "rule" was verbalized by the trainer in the "explicit-rule" condition. Bimodal generalization results occurred in both subject groups, indicating that generalization was not incremental. Chi-square analyses suggested that the SLI group generalized the bound morpheme less often than the NL group under the explicit-rule training condition. The findings add to those that indicate children with SLI have a unique language-learning style, and suggest that the explicit presentation of metalinguistic information during training may be detrimental to bound-morpheme generalization by preschool-age children with SLI.

Child↗
PubMed1993

Language matches: illuminating or confounding? Research note.

The practice of matching younger, language-matched controls, in addition to age-matched controls, is often used in studies of language-disordered children to examine the role of "language level" on performance. However, the interpretation of the relative performance of subjects in studies using such dual control groups is problematic. Conceptual concerns arise with the use of language matches because language is a multidimensional skill that is not reflected equivalently for the language-disordered children and their language-matched controls. Furthermore, matching by language level inevitably introduces an extraneous age effect that confounds interpretation. In addition, erroneous interpretations of null findings can occur when no differences are found between language-disordered and language-matched groups.

Age Factors↗
PubMed1992

Relations among verbal and nonverbal cognitive skills in normal language and specifically language-impaired children.

This study tested the hypothesis that specifically language-impaired (SLI) children have a qualitatively different cognitive system from that of normal language (NL) children. Twenty NL and 20 SLI children between the ages of 4:2 (years:months) and 5:11 were presented with experimental language-learning measures, experimental nonverbal measures, and verbal and nonverbal norm-referenced tests. A confirmatory analysis of the covariance matrix structures of the two subject groups indicated that relations among cognitive skills differed between NL and SLI children. In addition, a planned comparison indicated that the relation between nonverbal rule-induction and novel bound-morpheme learning differed significantly between groups. The findings indicate that a "qualitative-differences" model of specific language impairment better accounts for the co-occurrence of poor verbal and poor nonverbal cognitive skills in SLI children than a "low-normal" model.

Child, Preschool↗
PubMed1990

Nuclear transport of plant potyviral proteins.

We have used immunoblotting, immunocytochemical, and gene fusion methods to examine the differential subcellular partitioning of tobacco etch potyvirus proteins that are potentially associated with RNA replication. From the earliest timepoints at which viral proteins could be detected, proteins Nla (49-kilodalton proteinase) and Nlb (58-kilodalton polymerase) were localized primarily in the nucleus, whereas the 71-kilodalton cylindrical inclusion protein was identified in the cytoplasm. The Nla and Nlb coding regions were fused to the beta-glucuronidase (GUS) sequence in a plant expression vector, resulting in synthesis of chimeric proteins in transfected protoplasts and in transgenic plants. In situ localization of GUS activity revealed nuclear localization of the GUS-Nla and GUS-Nlb fusion proteins and cytoplasmic localization of nonfused GUS. These results indicate that both Nla and Nlb contain nuclear targeting signals, and that they may serve as useful models for studies of plant cell nuclear transport. A discussion of the general utility of the nuclear transport system described here, as well as the role of nuclear translocation of potyviral proteins, is presented.

Cell Nucleus↗
PubMed1987

Isolation and characterization of abl gene sequences in Calliphora erythrocephala.

Screening of genomic DNA libraries with hybridization probes derived from a Drosophila melanogaster c-abl proto-oncogene homologue resulted in the isolation of a set of related sequences from the dipteran Calliphora erythrocephala. Although the region encompassing the c-abl protein kinase domain encodes a polypeptide extremely similar to the Drosophila gene, considerable inter- and intraspecific divergence is found adjacent to this region. Restriction-site heterogeneity and cross-hybridization studies between individual cloned isolates suggest that abl homologues represent a small gene family in the Calliphora genome. As is the case in Drosophila, abl-related transcripts appear to be low in abundance, are synthesized during oogenesis and stored as a maternal mRNA.

Animals↗
PubMedDate not supplied

DNA sequence analysis and structural relationships among the cytoskeletal actin genes of the sea urchin Strongylocentrotus purpuratus.

The general organization and primary amino acid sequences of the S. purpuratus cytoskeletal actin genes CyIIb and CyIIIb have been determined from restriction enzyme analysis, DNA sequencing, and RNA mapping studies. As is the case with the other sea urchin cytoskeletal actin genes previously studied, the CyIIb and CyIIIb genes contain two introns that interrupt the coding DNA following codon 121 and within codon 204. An intron ending 26-27 nucleotides (nt) upstream of the initiation codon has also been localized in the 5'-flanking region of both genes. The CyIIb gene, which is part of a cluster of three genes linked in the order CyI-CyIIa-CyIIb, encodes a protein that differs from CyI by a single residue and from CyIIa by three residues. The substitutions observed within this linkage group are relatively conservative changes, and pairwise comparisons between genes indicate less than 5% mismatch in nucleotide sequence within the coding region. Nucleotide sequence comparisons of 5'-flanking region and intron DNA, however, indicate greater similarity between the CyI and CyIIb genes than the CyIIa gene that separates them, suggestive of a potential gene conversion event between the flanking genes in the CyI-CyIIa-CyIIb linkage. The CyIIIb gene, part of a separate cluster of two functional genes ordered CyIIIa-CyIIIb, shares little similarity outside of coding DNA with genes of the other linkage group. Although CyIIIb exhibits strong nucleotide sequence similarity outside of coding DNA with the neighboring CyIIIa gene, it differs from that gene at six codons. The CyIIIb gene encodes a protein considerably different from all cytoskeletal actins previously reported, with changes clustered in the latter 40% of the coding sequence. An 81-nt tandem duplication of the C-terminal coding region is located adjacent to the termination codon of the CyIIIb gene, a potential relic of a slipped mispairing and replication event.

Actins↗
PubMedDate not supplied

[A system of multidimensional behavior assessment. A scale for parents of children from 6 to 11 years of age. Colombian version].

INTRODUCTION: Behavioral Assessment System for Children (BASC) has demonstrated to be useful in the diagnosis of Attention Deficit Disorder (ADD). PATIENTS AND METHODS: A randomized sample of 120 children, 6 to 11-year-old, participants from the school of the city of Medellín, Colombia, was selected. The sample was stratified by sex and two socioeconomic status (SES). Parents were asked to answer the BASC Parent Rating Scale (PRS) 6-11, authorized Spanish version. RESULTS: Cronbach's alpha coefficient was 0.85 for the clinical scale (9 items). It was 0.75 for the Adaptive Scale (3 items). A scale designed with 4 items to assess ADD (hyperactivity, attention problems, aggression, and conduct problems) showed an alpha coefficient of 0.82. Male children scored significantly higher than female (ANOVA, p < 0.05) in hyperactivity, conduct problems, and atypicality. Children from low SES scored significantly higher than children of high SES on the most of clinical measures (p < 0.05) and lower on the three adaptive measures. Cluster analysis selecting six clusters found a prevalence of 61.6% for normal male children. In the total sample there were a 4% at risk of DDA type II (inattentive) and 14% at risk of DDA type I (combined). CONCLUSIONS: BASC PRS (6-11) showed reliability and validity to assessing the behavior in Spanish speaking Colombian children.

Attention Deficit Disorder with Hyperactivity↗
PubMedDate not supplied

[Different verbal behavior in children with attention deficit between 7 and 12 years of age].

INTRODUCTION: According to factor brain organization of cognition model, it has been proposed that there are specific a shared underlie factors in the structure of each cognitive functions. OBJECTIVE: To determine if children with attention deficit disorder (ADD) have different verbal abilities than controls, and if verbal behaviors are related to inattention and hyperactive symptoms. PATIENTS AND METHODS: 32 children with attention deficit without hyperactivity (ADD/-H), 28 children with attention deficit hyperactivity (ADD/+H), according to DSM-IV criteria and higher than 60-T-Score on an ADHD checklist, and 32 control children were selected. Age, sex, school achievement, and socioeconomic status were controlled. All children had a WISC-R performance intelligence quotient (PIQ) > 80 and were 7-to-12-year old. Verbal test to assess comprehension, inferences, narrative, fluency, analogies and rapid naming were applied. RESULTS: Children from both ADD groups obtained significant lower WISC-R verbal intelligence quotient (VIQ), PIQ, full scale IQ (FSIQ), and phonologic fluency score than controls (ANOVA-Bonferroni's correction p < 0.005). ADD/+H children performed significant lower than controls in narrative and analogies (p < 0.005). An analysis of covariance (ANCOVA), using FSIQ as covariable, showed that phonologic verbal fluency continued presenting significant differences between control and ADD children. Inattention-hyperactivity checklist scores had significant inverse and mild correlations with inferences, items recalled in a narrative, phonologic verbal fluency, and analogies (r > -0.20, p < 0.05). There were significant and small correlations between inattention score and rapid naming errors, and between Inattention and rapid naming time (r > 0.20, p < 0.05). CONCLUSION: Our data found different verbal production, fluency and speed in ADD/+H and ADD/-H children. There were shared underlie relations between verbal abilities and behavioral symptoms.

Attention Deficit Disorder with Hyperactivity↗
PubMedDate not supplied

[The use of brief questionnaire in the diagnosis of attention deficit. Study group of the Manizales University Foundation].

INTRODUCTION: American Psychiatric Association has defined the DSM-IV ADD diagnostic criteria and symptoms, however, there is not a quantitative instrument to evaluate them in Spanish speaker population. OBJECTIVE: To evaluate the utility of a ADD checklist in a Colombian schooling population. PATIENTS AND METHODS: A randomized and stratified by sex, age and socioeconomic level, 4 to 17-year old, sample of 540 schooling subjects was selected from Manizales City, Colombia. An ADD checklist was applied to the parents of these subjects. RESULTS: The reliability of the different dimensions of the questionnaire (18 total items, 9 items for inattention, 9 for hyperactivity-impulsivity, and 6 for hyperactivity) were strong in both sex and in all age groups (Cronbach's alpha coefficient 0.71-0.92). Only the impulsivity dimension formed by three variables showed fairly weak reliability (0.42-0.79 Cronbach's alpha). Some factorial analysis found two dimensions. In the male sample first dimension (inattention) explain around the 45% of the variance, and the second dimension (hyperactivity-impulsivity) explain around the 12 to 15% of the variance in the different age groups. In the female sample the first dimension was hyperactivity-impulsivity and the second dimension was inattention. A categorical (yes or not) scored questionnaire found a ADD estimated prevalence of 16.1, distributed in type I (combined) 3.3%, in type II (inattentive) 4.3%, and type III (hyperactive-impulsive) 8.5%. Male prevalence was 19.8% and female 12.4%. CONCLUSIONS: ADD checklist Spanish version showed a strong reliability. A bidimensional stable structured was found. A clinical related ADD prevalence was presented, it was much higher than the prevalence of the developed countries.

Adolescent↗