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Biomedical subjects

M Heimann

Publications and source records attributed to M Heimann.

At least 19 recordsLinked to original sources
PubMed2006

[Diffusion tensor imaging (DTI) and its importance for exploration of normal or pathological brain development].

Diffusion tensor MR imaging (DTI) can provide in vivo unique information on integrity of white matter structures (anisotropy) and connectivity (fiber tracking) in the human brain. This is made possible by means of non-invasive MR-based technique. The purpose of this article is to review the method and the current applications of diffusion tensor MR imaging. Studies of the past decade featuring relevant neuropsychiatric disorders as well as disorders in child psychiatry are reviewed. Furthermore, this report offers a summary of DTI-studies in children and adolescents showing alterations in brain or CNS structures including neurological, traumatological and oncological investigations. In particular, it focuses on the importance of this method with respect to exploration of normal and pathological brain development.

Anisotropy↗
PubMed2004

Psychological follow-up study of 5-year-old ICSI children.

BACKGROUND: The developmental outcomes of children born after ICSI are still a matter of concern. The purpose of the present study was to investigate psychological outcomes for 5-year-old children born after ICSI and compare these with outcomes for children born after spontaneous conception (SC). METHODS: Three hundred singleton children born after ICSI in Belgium, Sweden and the USA were matched by maternal age, child age and gender. Outcome measures included the Wechsler Preschool and Primary scales of intelligence (WPPSI-R), Peabody Developmental Motor Scales, Parenting Stress Index and Child Behaviour Checklist. RESULTS: Regarding cognitive development, no significant differences were found on WPPSI-R verbal and performance scales between ICSI and SC children. However, some differences were noted on subtests of the Performance Scale. ICSI children more often obtained a score below 1 SD of the mean on the subtests: Object Assembly, Block Design and Mazes (all P<0.05). Significant differences by site (i.e. Belgium, Sweden and New York) were found on subtests related to parenting stress, child behaviour problems and motor development (all P<0.05). These findings can probably be explained by variables other than conception mode, such as cultural differences and selection bias. CONCLUSIONS: Although the finding that a higher proportion of ICSI children obtained scores below the cut-off on some of the visual-spatial subscales of the WPPSI-R warrants further investigation, ICSI does not appear to affect the psychological well-being or cognitive development at age 5.

Birth Weight↗
PubMed2003

Resolution of chylothorax after resection of rib chondroma in a dog.

A six-year-old, male dobermann was presented with a history of dyspnoea and bouts of coughing. Radiography and computed tomography of the thorax showed pleural effusion and a well-circumscribed, calcified mass of 10 cm in diameter, appearing to originate from the left first rib. Thoracocentesis revealed that the pleural fluid was chylous in nature. An incisional biopsy was performed, which gave a histological diagnosis of chondroma. Resolution of the chylothorax after en-bloc surgical removal of the tumour suggested that the rib tumour was the initiating cause of the chylothorax. Seventeen months later, rib neoplasia recurred without pleural effusion, and was removed successfully. To the authors' knowledge, rib chondroma, which is an unusual tumour in dogs, has not been previously documented as a cause of chylothorax.

Animals↗
PubMed2001

Recent patterns and mechanisms of carbon exchange by terrestrial ecosystems.

Knowledge of carbon exchange between the atmosphere, land and the oceans is important, given that the terrestrial and marine environments are currently absorbing about half of the carbon dioxide that is emitted by fossil-fuel combustion. This carbon uptake is therefore limiting the extent of atmospheric and climatic change, but its long-term nature remains uncertain. Here we provide an overview of the current state of knowledge of global and regional patterns of carbon exchange by terrestrial ecosystems. Atmospheric carbon dioxide and oxygen data confirm that the terrestrial biosphere was largely neutral with respect to net carbon exchange during the 1980s, but became a net carbon sink in the 1990s. This recent sink can be largely attributed to northern extratropical areas, and is roughly split between North America and Eurasia. Tropical land areas, however, were approximately in balance with respect to carbon exchange, implying a carbon sink that offset emissions due to tropical deforestation. The evolution of the terrestrial carbon sink is largely the result of changes in land use over time, such as regrowth on abandoned agricultural land and fire prevention, in addition to responses to environmental changes, such as longer growing seasons, and fertilization by carbon dioxide and nitrogen. Nevertheless, there remain considerable uncertainties as to the magnitude of the sink in different regions and the contribution of different processes.

Journal Article↗
PubMed2001

Interaction patterns between children and their teachers when using a specific multimedia and communication strategy: observations from children with autism and mixed intellectual disabilities.

This study reports on observed interaction patterns between 20 children with autism and mixed intellectual disabilities (mean chronological age = 11:4 years; language age = 4:7 years) and their nine teachers working with a specially developed multimedia program aiming to increase literacy skills. An increase in verbal expression was found over time for the total group. Children with autism also showed increased enjoyment and willingness to seek help from their teachers. Teachers for both diagnostic groups reduced their instructions on how to handle the computer during the program but the decrease was greater in the teachers for children with autism. When the total group of children was subdivided according to language age (high versus low), it appears that those with a low language age showed an increase in verbal expressiveness from start to end of training. Those with a high language age showed increased enjoyment. It is concluded that more detailed studies of the interaction patterns between teachers and children are needed, and these should be related to children's language level as well as to diagnostic group.

Adolescent↗
PubMed2000

Climate change. Managing forests after Kyoto.

The Kyoto protocol aims to reduce carbon emissions into the atmosphere. Part of the strategy is the active management of terrestrial carbon sinks, principally through afforestation and reforestation. In their Perspective, Schulze et al. argue that the preservation of old-growth forests may have a larger positive effect on the carbon cycle than promotion of regrowth.

Carbon↗
PubMed2000

High mortality rate associated with bovine respiratory syncytial virus (BRSV) infection in Belgian white blue calves previously vaccinated with an inactivated BRSV vaccine.

In a group of 60 Belgian White Blue calves less than 8 months old still housed in barns, a bovine respiratory syncytial virus (BRSV) outbreak was revealed on the basis of a direct diagnosis (immunofluorescence and virus isolation) performed on the lungs of dead animals, and the kinetics of BRSV neutralizing antibodies. Clinical signs, macroscopical and microscopical pulmonary lesions were also compatible with a BRSV infection. This outbreak is peculiar because the 35 oldest calves (204 +/- 29 days old) had been vaccinated 3-4 months before with an inactivated BRSV vaccine and 30% of these animals had died of respiratory distress. While they experienced a mild respiratory symptomatology, no death was recorded among the 25 youngest calves (69 +/- 29 days old) which had been left unvaccinated. Another peculiarity was found at the histological level where a massive infiltration of eosinophils was demonstrated in the pulmonary tissues of the dead animals. Together these data parallel the dramatic story described 30 years ago in children previously vaccinated with a formalin-inactivated human RSV (HRSV) vaccine upon a natural HRSV challenge. This illustrates that an immunopathological phenomenon also takes place after BRSV vaccination in cattle.

Animals↗
PubMed1998

N-terminal protease of pestiviruses: identification of putative catalytic residues by site-directed mutagenesis.

Pestiviruses are the only members of the Flaviviridae that encode a nonstructural protease at the N terminus of their polyproteins. This N-terminal protease (Npro) cleaves itself off of the nascent polyprotein autocatalytically and thereby generates the N terminus of the adjacent viral capsid protein C. In previous reports, sequence similarities between Npro and the catalytic residues of papain-like cysteine proteases were put forward. To test this hypothesis, substitutions of cysteine and histidine residues within Npro were carried out by site-directed mutagenesis. Translation of the mutagenized Npro-C proteins in cell-free lysates confirmed that only the predicted Cys69 was an essential amino acid for proteolysis, not His130. Further essential residues were identified with His49 and Glu22. While it remains speculative whether Glu22-His49-Cys69 actually build a catalytic triad, these results invalidate the assumption that Npro is a papain-like cysteine protease.

Amino Acid Sequence↗
PubMed1998

Imitation in eight young infants with Down's syndrome.

Imitation of tongue protrusion and mouth opening was studied in eight infants with Down's syndrome. Five of the children were observed at approximately 1 mo, seven around 3 mo, and seven at 4 mo. The only significant group result revealed imitation of tongue protrusion at 1 mo. In addition, a descriptive analysis of each child's response pattern during the presentation period showed that all five children observed at 1 mo imitated tongue protrusion and that four of them also seemed to imitate mouth opening. The result for the 3-mo observation was some-what inconsistent. All but one of the infants increased their response rates of both tongue protrusion and mouth opening when mouth opening was modeled. At 4 mo imitation seems to disappear. Overall, the findings are in agreement with what is known from typically developing children.

Down Syndrome↗
PubMed1997

Early dynamics of acute extradural and subdural hematomas.

In a retrospective study volumes of 42 extradural and 102 subdural traumatic hematomas were evaluated. Results were related with the time interval between injury and initial CT scan, outcome, coma grade and subject age. Mean volumes were found to increase with time after the injury. In the first hour volumes of 8 intracranial hematomas were hardly space consuming, while they became clearly space consuming in the second and in later hours after the injury. It was therefore concluded that it should not take longer than one hour until a CT scan be performed when an intracranial post-traumatic hematoma is suspected in the comatose patient.

Acute Disease↗
PubMed1995

Influence of tyrosine residues Y705 and Y807 on the transforming potency of the v-fms oncogene product of feline sarcoma virus.

Cell transformation is characterized by overt changes in growth control and cell morphology. To study the role of tyrosine residues Y705 and Y807 of v-Fms of the McDonough strain of feline sarcoma virus in cell transformation we replaced them individually with phenylalanine residues. Cells expressing the mutant genes showed mitogenic properties similar to wild-type v-Fms transformed cells. However, the morphology of cells expressing the Y807F mutant remained the same as nontransformed cells. Four phosphoproteins of 190, 120, 55 and 50 kDa were detected in cells expressing the wild-type but were absent in cells expressing the mutant Y807F-v-fms gene.

Base Sequence↗
PubMed1995

Increasing reading and communication skills in children with autism through an interactive multimedia computer program.

This paper reports on the effect of using an interactive and child-initiated microcomputer program (Alpha) when teaching three groups of children (N = 30) reading and communications skills: (a) 11 children with autism (M chronological age, CA = 9:4 years), (b) 9 children with mixed handicaps (M CA = 13:1), and (c) 10 normal preschool children (M CA = 6:4 years). Their mental age varied from 5:8 years to 6:9 years and all children received computer instruction supplementary to their regular reading and writing activities. Tests of reading and phonological development were carried out at the onset of the training (Start), at the end (Post 1), and at a follow-up evaluation (Post 2). In addition, video observations of the childrens' verbal and nonverbal communication were added at Start and Post 1. The children with autism increased both their word reading and their phonological awareness through the use of the Alpha program. Clearly significant gains were observed during the intervention, but none during the follow-up period. A similar but weaker pattern is observed for the children with mixed handicaps. In contrast, the normal preschool children increased their scores regardless of the program. Analyses of the children's classroom behavior indicate that the intervention succeeded in stimulating verbal expressions among the children with autism and mixed handicap. A significant increase in enjoyment was also noted for the children with autism. It is concluded that the intervention with a motivating multimedia program might stimulate reading and communication in children with various developmental disabilities, but that such interventions must be individually based and include both detailed planning and monitoring from teachers, and parents, as well as from clinicians in charge.

Adolescent↗
PubMed1993

Oral-facial-digital syndrome type I in a newborn male.

We report on a newborn male, born at term with clinical manifestations of oral-facial-digital (OFD) syndrome type I. This syndrome is generally assumed to be inherited in an X-linked dominant fashion with lethality in males. Therefore, liveborn males are exceptional. This liveborn male also had Dandy-Walker malformation and polycystic kidneys. From a general point of view, distinction between the 8 types of OFD syndromes described so far appears subtle and considerable overlap exists between them. In this regard, it should be noted that polycystic kidneys different from adult polycystic kidney disease both macroscopically and microscopically are a frequent manifestation of OFD I.

Dandy-Walker Syndrome↗
PubMed1989

Neonatal imitation of tongue protrusion and mouth opening: methodological aspects and evidence of early individual differences.

The present work examines imitation of mouth opening and tongue protrusion in 32 full-term infants at three different occasions: When the infants are two to three days, three weeks, and three months old. The analysis focuses (1) on individual differences in imitative behaviour and (2) on how to operationalize the infants' responses. The overall group analysis revealed that imitation of tongue protrusion was statistically significant for both two- to three-day-old and three-week-old infants but not when the children had become three months old. No statistically significant effect was observed for imitation of mouth opening. Two different imitation indexes were constructed in order to assess individual differences in early imitative behaviour. Results show that short-term stability in imitative tendencies exists between the first and second observation. The results further reveal that methodological factors must be seriously considered when studying neonatal imitation: the overall imitation found for tongue protrusion is demonstrated to be dependent on how the infants' responses are coded.

Female↗