Biomedical subjects

K Verschueren

Publications and source records attributed to K Verschueren.

26 records · Page 2Linked to original sources

PubMed1996

The internal working model of the self, attachment, and competence in five-year-olds.

The present studies examine some of the correlates of the self in the lives of young children. In Study 1, the connection is tested between young children's internal working model of self and their competence, social acceptance, behavioral adjustment, and behavioral manifestations of self-esteem. Ninety-five kindergartners aged between 51 and 76 months (Mage = 5 years, 3 months) participated in the study. An adapted version of the Puppet Interview was used to assess the representation of self. Affective quality (positiveness) of self and openness to admit imperfections were rated independently. Results show significant and positive relations of the positiveness of self with competence and social acceptance, with behavioral adjustment to school, and with behavioral manifestations of self-esteem, all rated by the teacher. In Study 2, Bowlby's assumption was tested that the working model of self is closely intertwined with the working model of attachment to mother. Subjects were 50 children aged between 55 months and 75 months (Mage = 5 years, 5 months). The working model of child-mother attachment was assessed through an Attachment Story Completion Task. The working model of self was measured via the Puppet Interview. Results show a positive and strong connection between the security of the child-mother attachment representation and the positiveness of self. The results of the two studies contribute to the validation of the adapted Puppet Interview. The Puppet Interview seems to be a promising instrument for assessing the representation of self in young children.

Child↗

PubMed1995

Expression of type I and type IB receptors for activin in midgestation mouse embryos suggests distinct functions in organogenesis.

Activins exert their effects by inducing heteromeric complexes of either of two different type I receptors, ActR-I or ActR-IB, and either of two type II receptors, ActR-II or ActR-IIB. We describe the cDNA cloning of the mouse homologue of human ActR-IB and analyze binding of radio-iodinated activin on type I/type II combinations of mouse receptors expressed from cDNA. We studied the distribution of ActR-I and ActR-IB mRNAs in postimplantation mouse embryos by in situ hybridization. In the 12.5-day postcoitum embryo, both mRNAs are found in the brain, spinal cord, some ganglia, vibrissae, lungs, body wall, stomach, gonads, ribs, limbs and shoulders. ActR-I mRNA, but not ActR-IB, is expressed in blood vessels, the heart, tongue, intervertebral discs and diaphragm. Conversely, only ActR-IB mRNA is detected in the olfactory region, eye, tooth primordium, esophagus, mesonephros, dorsal root ganglia and is strongly expressed in the spinal cord. Our results demonstrate similarities, but also differences and complementarities (mesenchymal versus epithelial expression) between the expression patterns of these type I receptors. Moreover, their expression patterns overlap with at least one of the type II activin receptors and/or one of activin subunits in some regions of the embryo, such as the brain, spinal cord, pituitary, whisker follicles, and the inner nuclear neuroblastic layer of the eye.

Activin Receptors↗

PubMed1995

Distinct spatial and temporal expression patterns of two type I receptors for bone morphogenetic proteins during mouse embryogenesis.

Bone morphogenetic proteins (BMPs) are multifunctional proteins structurally related to transforming growth factor-beta (TGF beta) and activin that can induce cartilage and bone growth in vivo. Members of the TGF beta superfamily exert their biological effects via heteromeric serine/threonine kinase complexes of type I and type II receptors. We previously obtained six different type I receptors, termed activin receptor-like kinase-1 (ALK-1) to -6. ALK-5 is a TGF beta type I receptor, ALK-2 and ALK-4 are activin type I receptors, and ALK-3 and ALK-6 are type I receptors for osteogenic protein-1 (OP-1)/bone morphogenetic protein-7 (BMP-7) and BMP-4. Here we report the complementary DNA cloning of the mouse homolog of ALK-3, which is highly conserved between mouse and man. ALK-3 messenger RNA (mRNA) is ubiquitously expressed in various adult mouse tissues, whereas ALK-6 mRNA is only found in brain and lung. The distribution of ALK-3 and ALK-6 mRNA in the postimplantation mouse embryo [6.5-15.5 days postcoitum (pc)] was studied by in situ hybridization. ALK-3 was nearly ubiquitously expressed throughout these stages of development, but was notably absent in the liver. In contrast, ALK-6 showed a more restricted expression pattern. ALK-6 mRNA was absent in early postimplantation embryos, was detected first in 9.5 days pc embryos, and persisted until 15.5 days pc. In midgestation embryos, ALK-6 transcripts were detected in mesenchymal precartilage condensations, premuscle masses, blood vessels, central nervous system, parts of the developing ear and eye, and epithelium. The expression in sites of developing cartilage and bone supports the idea that ALK-3 and -6 are receptors for BMPs in vivo. In addition, the expression of these genes in many soft tissues suggests broader functions for BMPs in embryogenesis.

Activin Receptors↗

PubMed1995

The meaning of grandparents as viewed by adolescent grandchildren: an empirical study in Belgium.

Why do adolescents value their grandparents? This was the leading question of an investigation among 563 adolescents and young adults in Flanders (Belgium). The Grandparent Meaning Scale which probes eleven a priori dimensions of meaning, was completed by 147 early adolescents (M = 12.5 years), 175 middle adolescents (M = 15.7 years), and 241 late adolescents (M = 18.9 years). Results show that adolescents generally find their grandparents important and feel close to them. Grandparents are valued primarily because they provide affection, reassurance of worth, and reliable alliance. Relational-affective and caregiving meanings were assigned more often to grandmothers whereas advising, teaching, and narrative roles were ascribed more frequently to grandfathers. Maternal grandparents were generally perceived as more important and closer than paternal grandparents. Early adolescents assigned more importance and meaning to their grandparents than middle and late adolescents. There were no differences between grandsons and granddaughters.

Adolescent↗

PubMed1993

[Significance of grandparents for young-adult grandchildren].

Do young adult grandchildren find their grandparents important? What are the meanings that grandparents seem to have for these grandchildren? Those were the leading questions in the present study. Subjects were 239 university students (mean age: 19.5 years). They completed the Grandparents Meaning Scale, a recently developed 82-item instrument which probes for 11 a priori dimensions of meaning of grandparents for grandchildren: (I) Reliable alliance, (2) Affection and emotional support, (3) Reassurance of worth, (4) Practical and financial support, (5) Link with the past, (6) Acquaintance with aging, (7) Mentor and role-model, (8) Kinkeeper, (9) Mediator between children and parents, (10) Substitute caregiver, and (11) Distant figure. Subjects rated the importance and meaning of 222 grandmothers and 159 grandfathers. The results confirmed earlier findings. Young adult grandchildren generally found their grandparents important. Grandparents were valued because they provide their grandchildren with reassurance of worth and emotional support, and link their lives to the historical past. Grandmothers received higher scores than grandfathers on seven scales (1-4, 8-10). Grandfathers had higher scores on just two of the scales (5 and 11). Gender differences emerged with regard to the ratings of the grandmothers only. Girls had higher scores than boys on eight scales (1-3, 5, 7-10) and boys had a higher score on just one scale (11).

Adult↗

PubMed1985

General amino acid control and specific arginine repression in Saccharomyces cerevisiae: physical study of the bifunctional regulatory region of the ARG3 gene.

To characterize further the regulatory mechanism modulating the expression of the Saccharomyces cerevisiae ARG3 gene, i.e., the specific repression by arginine and the general amino acid control, we analyzed by deletion the region upstream of that gene, determined the nucleotide sequence of operator-constitutive-like mutations affecting the specific regulation, and examined the behavior of an ARG3-galK fusion engineered at the initiating codon of ARG3. Similarly to what was observed in previous studies on the HIS3 and HIS4 genes, our data show that the general regulation acts as a positive control and that a sequence containing the nucleotide TGACTC, between positions -364 and -282 upstream of the transcription start, functions as a regulatory target site. This sequence contains the most proximal of the two TGACTC boxes identified in front of ARG3. While the general control appears to modulate transcription efficiency, the specific repression by arginine displays a posttranscriptional component (F. Messenguy and E. Dubois, Mol. Gen. Genet. 189:148-156, 1983). Our deletion and gene fusion analyses confirm that the specific and general controls operate independently of each other and assign the site responsible for arginine-specific repression to between positions -170 and +22. In keeping with this assignment, the two operator-constitutive-like mutations were localized at positions -80 and -46, respectively, and thus in a region which is not transcribed. We discuss a hypothesis accounting for the involvement of untranscribed DNA in a posttranscriptional control.

Amino Acid Sequence↗

PubMedDate not supplied

Remarkable versatility of Smad proteins in the nucleus of transforming growth factor-beta activated cells.

Smad proteins were identified three years ago as intracellular mediators of signaling by Transforming Growth Factor-beta (TGF-beta) family members. Two subclasses of the Smad proteins, the receptor-regulated Smads and common mediator Smads, transduce signals from the cell surface to the nucleus, where they participate in the regulation of gene expression. Meanwhile, it has become evident that Smads should be envisaged as very versatile proteins, which integrate multiple signaling pathways and can directly affect target gene expression in many ways. Indeed, their direct binding to DNA and their interaction in the nucleus with non-Smad proteins, many of which are DNA-binding activators or repressors of transcription uncover a unique but complex mode of action. We summarize some of the most recent data with regard to this aspect in this rapidly advancing field.

Animals↗

PubMedDate not supplied

Representation of self and socioemotional competence in kindergartners: differential and combined effects of attachment to mother and to father.

In the present study, we examined the differential predictive power and the joint or compensatory effects of representations of child-mother and child-father attachment for children's representation of self and their socioemotional competence. The representations of attachment were assessed by an attachment story completion task, completed once for mother and once for father (in counterbalanced order). Eighty participants (40 boys and 40 girls), aged between 55 and 77 months (M = 5 years 3 months), took place in the study. The socioemotional competence (peer social competence, disruptive behavior, anxious/withdrawn behavior, and school adjustment) and behavioral manifestations of self-esteem were evaluated by the kindergarten teacher. The inner representation of self (positiveness of self, perceived competence, and social acceptance) was assessed in a subgroup of 50 children. Results showed that the relative predictive power of child-mother and child-father attachments differed according to the domain of child functioning that was assessed. More specifically, it was found that the child's positiveness of self was better predicted by the quality of the child-mother attachment representation than by the quality of the child-father attachment representation. In contrast, the child's anxious/withdrawn behavioral problems were better predicted by the quality of the child-father attachment representation than by the quality of the child-mother attachment representation. With regard to the joint effects of child-mother and child-father attachment, it was found that a secure attachment to one parent can compensate for or buffer against an insecure attachment to the other parent. However, the buffering effect was not complete.

Affect↗