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Biomedical subjects

B Mathisen

Publications and source records attributed to B Mathisen.

8 recordsLinked to original sources
PubMed1995

Migratory patterns of lac-z transfected human glioma cells in the rat brain.

Malignant brain tumors are characterized by extensive tumor-cell infiltration into the normal brain tissue. The present work describes the migratory behavior of human glioma cells transplanted into the adult rat brain with the aim of exploiting the extent of active cell migration and passive cell displacement within the central nervous system. To detect every transplanted tumor cell, a stably bacterial beta-galactosidase (lac-z) transfected human glioma cell line was used. To distinguish between an active cell migration process and passive cell displacement, rat brains were also implanted with inert fluorescent polystyrene microspheres and the distribution of tumor cells and microspheres was studied 1 hr and 3 days after implantation. One hour after implantation the tumor cells were strictly localized at the implantation site. However, 3 days after implantation, both tumor cells and microspheres showed an extensive distribution within the brain. Confirming earlier neuropathological and experimental studies, it is shown that the lac-z-transfected glioma cells had the capacity to move within the Virchow-Robin and subarachnoid spaces. However, since fluorescent microspheres were also found in these areas, this spread of tumor cells may be primarily mediated by the extensive cerebrospinal fluid flow that exists within the brain. Three days after implantation, the glioma cells also showed an active migration over the corpus callosum. In comparison, the fluorescent microspheres showed only limited spread along the callosal body. It is concluded that the bacterial lac-z gene can be stably transfected into human glioma cells and, since every tumor cell can be visualized within the brain, this model provides a tool for studying the mechanisms behind tumor-cell invasion of the brain.

Animals↗
PubMed1995

The objective rating of oral-motor functions during feeding.

The Schedule for Oral Motor Assessment (SOMA) was developed to record oral-motor skills objectively in infants between ages 8 and 24 months postnatal. Its aim is to identify areas of dysfunction that could contribute to feeding difficulties. The procedure takes approximately 20 min to administer, and is intended to be rated largely from a videorecording of a structured feeding session. A series of foodstuffs of varying textures, including liquids, is presented to the child in a standardized manner. Oral-motor skills are evaluated in terms of discrete oral-motor movements. The schedule distinguishes these from skills at more aggregated levels of functioning such as jaw, lip, and tongue control. A total of 127 children have been studied with the instrument, including normal healthy infants and samples with nonorganic failure to thrive, and cerebral palsy. Interrater and test-retest reliabilities were determined on a subset of 10 infants who each took part in three trials rated by 2 therapists. Excellent levels of interrater reliability (kappa > 0.75) were obtained for the presence/absence of 69% of discrete oral-motor behaviors. Test-retest reliability was similarly excellent for 85% of ratable behaviors. For the first time an assessment of oral-motor functioning has been shown to have adequate reliability for children aged 8-24 months. The validation of the SOMA on a large sample of normally developing infants and its application to clinical groups is presented in an accompanying paper [1].

Bottle Feeding↗
PubMed1995

Schedule for oral-motor assessment (SOMA): methods of validation.

The Schedule for Oral Motor Assessment (SOMA) was developed for the purpose of objectively rating the oral-motor skills of preverbal children, with a view to identifying areas of deficient abilities that could have clinical significance. The instrument can be administered without special equipment, by a trained observer. Oral-motor function is assessed across a range of food textures and fluids. Ratings of oral-motor skills are largely made post hoc by analysis of a videorecording of the test administration. The test-retest and interrater reliability of the instrument have been shown to be excellent. Criterion validity was investigated by means of a novel 'seeded cluster analysis' procedure in which 127 young children were assessed, most of whom were between 8 and 24 months of age. Ten percent of the sample had known abnormal oral-motor function in association with cerebral palsy (ages between 12 and 42 months). Not only was criterion validity satisfactorily established by the analysis but an abbreviated version of the SOMA--suitable for screening purposes--was developed. This has been shown to have a positive predictive validity greater than 90% and sensitivity greater than 85% for the detection of infants with clinically significant oral-motor dysfunction.

Cerebral Palsy↗
PubMed1992

Oral-motor dysfunction and feeding disorders of infants with Turner syndrome.

The oral-motor function of 10 infants with Turner syndrome and their age- and sex-matched controls were assessed during feeding. In addition to well-recognised dysmorphic features, including oral anomalies and high-arched palates, index infants had marked hypotonia of the cheeks and lips, dysfunctional tongue movements and poorly developed chewing skills. Their meal-times were significantly shorter than those of the controls and they weighed significantly less at six, 12 and 15 months. All mothers of infants with Turner syndrome complained of difficulties feeding their children and these problems often had been present since birth.

Child, Preschool↗
PubMed1990

Behavioral style in failure-to-thrive infants: a preliminary communication.

In a pilot inner-city survey, nine 1-year-old infants with nonorganic failure to thrive (NOFT) and pairwise matched controls from the same deprived inner-city area were studied at home. A multimethod approach to the study of infant behavioral style was adopted. A consistent pattern of NOFT infants' behaviors in mothers' descriptions, in observation of play behavior, and in interaction with the examiner during standard testing emerged. NOFT infants were found to be more fussy, demanding, and unsociable. They were also less task-oriented and persistent, and their mothers expressed more negative emotions during play interaction. Mental development was significantly delayed in NOFT infants. The findings emphasize the importance of behavioral contributions from both infant and mother to the relationship problems characteristic of NOFT.

Arousal↗
PubMed1989

Oral-motor dysfunction and failure to thrive among inner-city infants.

Non-organic failure to thrive among socio-economically deprived inner-city infants may be associated with abnormal oral-motor functioning and aspects of social adversity, such as disorganised meal-times. A Feeding Assessment Schedule was devised to rate oral-motor behaviour objectively and was used to test nine pairs of case and comparison children while they were being fed at home. Video-recordings were made for later analysis. The case infants had immature and abnormal oral-motor development that made them less able to be fed successfully. Temperamentally they were more 'difficult' than the comparison infants, and they were less adept at signalling their needs during meal-times. The case infants also were fed in inappropriate positions for their age, with more distractions and less suitable utensils.

Child↗