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Biomedical subjects

H von Voss

Publications and source records attributed to H von Voss.

At least 19 recordsLinked to original sources
PubMed2005

[MR imaging in congenital disorders of the brain].

MR imaging is an excellent tool for use in diagnosing congenital malformations of the brain. Such malformations cannot be reliably recognized or classified without an insight in to the basic processes of the fetal development of the brain. Cortical malformations are classically divided into (1) malformations of neuronal proliferation, i.e. of stem cell proliferation in the periventricular germinal matrix zone, (2) disorders of neuronal migration, i.e. of the radial migration of the neurons from the periventricular germinal matrix zone to the cortical surface, and (3) disorders of cortical organisation. Other cerebral malformations are agenesis or dysgenesis of the corpus callosum, encephaloceles and various kinds of holoprosencephaly. Chiari malformations and disorders on the Dandy-Walker spectrum are relatively common, primarily infratentorial disorders. Rarer infratentorial disorders are Joubert syndrome, rhombencephalosynapsis and Lhermitte Duclos syndrome.

Adolescent↗
PubMed2000

Human motor development and hand laterality: a kinematic analysis of drawing movements.

This study examines the developmental profiles of basic 'open-loop' drawing movements on the non-dominant hand (ND) in comparison with the dominant hand (D). Fifty-three right-handed children aged 7-14 years and 15 adults aged 27-43 years were examined. Each subject drew lines and circles of different sizes at maximum velocity with a pressure-sensitive pen on a computer graphics tablet. Small lines were drawn at 90 degrees to the axis of the forearm (lines using wrist movements (LWM)) and along the axis of the forearm (lines using elbow movements (LEM)). Larger lines were drawn at 90 degrees to the axis of the forearm (LEM). At both extremities, the movement frequencies of the proximally generated drawing movements increased in a parallel fashion at different levels. In LWM, the right-left-differences (RLD) were high in 7- to 8-year-old children; until puberty, the ND hand reached almost the performance of the D hand. In contrast, the RLD of the LFM increased at the same time. As adulthood approaches, frequencies of all drawings increased further while the LWM on the ND side remained stable. In adults, there were similar RLD for all line drawings involving predominantly flexion and extension movements. When drawing circles, the RLD were highest, though stable in all age groups. Hand laterality of pen use changes over time; these changes are dependent on complexity (combined/sequential cf. flexion-extension muscle activation) and on topography (proximal cf. distal movements). Distinct developmental profiles of motoneuronal populations of the cortex may be responsible for the distinct hand laterality effects and the decreasing variability of motor patterns. The drawing abilities and developmental changes on the untrained ND hand indicate that effector-specific practice plays a minor role.

Adolescent↗
PubMed2000

Development of externally guided grip force modulation in man.

We examined the development of externally guided changes of grip force with respect to force rate and direction of force change. Sixty-nine children, 3-6 years of age, and 17 adults produced increasing or decreasing isometric forces on a small cylindrical sensor using a pinch grip with visual feedback. Force changes were instructed with a visual tracking task. Ramp-like paradigms with both force increase and force decrease and two different target force rates were used (0.5 N/s, 1.25 N/s). Precision of force tracking showed clear age effects and was influenced by the required force rates and directions of force change. In adults, tracking errors were much more dependent on target force rate and direction than in children. Up to four years of age, the children tended to overshoot the target force change in a 'jump and wait' manner in all conditions except for fast target force decreases. Older children tended to overshoot only in the condition with slow target force decrease. Adults showed close undershooting in all conditions when following the target. Adults used either a continuous 'following' strategy or a 'see and catch-up' strategy. The distinct effects on tracking errors suggest an age-related change of strategies from a feedforward strategy with intermittent use of sensorimotor feedback towards a fairly parallel and well-integrated feedback and feedforward processing. A critical age appears to be around five to six years. We suggest that these age effects may reflect distinct developmental velocities of neuronal subpopulations of the cortex and of the cerebello-cortical connections.

Adult↗
PubMed1999

Externally guided control of static grip forces by visual feedback-age and task effects in 3-6-year old children and in adults.

This study has been devised to examine the visual feedback control of static grip force levels by pinch and by hand grip during pre-school age and in adults. 69 3-6-year old children and 17 adults were asked to establish and hold grip force levels defined by a visual target and feedback on the dominant and non-dominant hand by hand grip and by pinch grip. From 3 to 6 years of age, the time needed to establish requested grip force levels decreased by a third and the precision increased two-fold for hand grip but four-fold for pinch grip; in contrast to younger children, 5-6-year olds showed a marked superiority of 60% for the pinch grip compared to hand grip, decreasing to about 40% in adults. In the case of pinch grip, all individuals had worse results on higher force levels (children: 50%, adults: 32%). The young children generally tended to use too much force. Older children and adults were better by 75% under the condition of visual feedback vs. internal proprioceptive control (after withdrawing visual feedback). In contrast to previous findings in anticipatory grip force regulation, externally guided force regulation begins to develop during late nursery age. Specific developmental effects were found for grip style and for the ability to use visual feedback and to change from external to internal (proprioceptive) control, and to a lesser extent for force magnitude but not for hand laterality and gender. The findings are interpreted by different developmental velocities of motor areas which are responsible for force regulation mechanisms and for grip style.

Adult↗
PubMed1999

Breast feeding and obesity: cross sectional study.

OBJECTIVE: To assess the impact of breast feeding on the risk of obesity and risk of being overweight in children at the time of entry to school. DESIGN: Cross sectional survey SETTING: Bavaria, southern Germany. METHODS: Routine data were collected on the height and weight of 134 577 children participating in the obligatory health examination at the time of school entry in Bavaria. In a subsample of 13 345 children, early feeding, diet, and lifestyle factors were assessed using responses to a questionnaire completed by parents. SUBJECTS: 9357 children aged 5 and 6 who had German nationality. MAIN OUTCOME MEASURES: Being overweight was defined as having a body mass index above the 90th centile and obesity was defined as body mass index above the 97th centile of all enrolled German children. Exclusive breast feeding was defined as the child being fed no food other than breast milk. RESULTS: The prevalence of obesity in children who had never been breast fed was 4.5% as compared with 2.8% in breastfed children. A clear dose-response effect was identified for the duration of breast feeding on the prevalence of obesity: the prevalence was 3.8% for 2 months of exclusive breast feeding, 2.3% for 3-5 months, 1.7% for 6-12 months, and 0.8% for more than 12 months. Similar relations were found with the prevalence of being overweight. The protective effect of breast feeding was not attributable to differences in social class or lifestyle. After adjusting for potential confounding factors, breast feeding remained a significant protective factor against the development of obesity (odds ratio 0.75, 95% CI 0.57 to 0.98) and being overweight (0.79, 0.68 to 0.93). CONCLUSIONS: In industrialised countries promoting prolonged breast feeding may help decrease the prevalence of obesity in childhood. Since obese children have a high risk of becoming obese adults, such preventive measures may eventually result in a reduction in the prevalence of cardiovascular diseases and other diseases related to obesity.

Adult↗
PubMed1999

MR findings in a patient with Kernicterus.

We report on a 2.5-year-old boy with severe mental retardation, choreoathetosis, dystonia, muscle rigidity, opisthotonus and severe hearing impairment. He had history of severe hyperbilirubinaemia immediately after birth presumably due to ABO incompatibility. The history and the clinical picture suggested the diagnosis of Kernicterus. The MR imaging examination upon admission revealed bilateral signal intensity increase in the globus pallidum on T2-weighted sequences. Additionally, our patient showed signal intensity changes within the subthalamic nuclei, which is known to be another characteristic area of bilirubin deposition in Kernicterus.

Abnormalities, Multiple↗
PubMed1999

Effects of age on distally and proximally generated drawing movements: a kinematic analysis of school children and adults.

The effects of age on basic fine motor functions were assessed using a kinematic analysis of simple repetitive drawing movements in a sample of 53 right-handed children aged 7 to 14 years 11 months and 16 adults aged 27 to 54 years with no detectable abnormality with neurological examination. Lines, circles, and half-circles were drawn at a self-chosen and maximum velocity with a pressure-sensitive pen on a computer graphics tablet. Patterns generated by finger, wrist, and arm movements, and those generated by combined finger-wrist movements with and without a change in the drawing direction were analysed. The frequencies of all movement patterns increased until adulthood: 0.1 Hz per year for half-circles, 0.15 to 0.2 Hz per year for circles and lines generated by arm and wrist movements. The greatest increase (0.35 Hz per year) was observed for lines produced by finger movements. Differences in movement frequencies between finger versus wrist or arm movements when drawing lines decreased from about 3 Hz in 7- to 8-year-olds to 0.5 to 1 Hz in adolescents. In adults the difference between maximum finger, wrist, and arm movement frequencies decreased to almost zero. In contrast, the differences in movement patterns with and without change in direction remained stable until adulthood. Based on these results it is hypothesized that the differential effects of finger and more proximally generated movements on age reflect maturation of distinct neuronal sites of the corticostriatal-cerebellar circuit rather than acquisition of motor skills or myelinization of corticospinal pathways.

Adolescent↗
PubMed1998

Road injuries in school age children: relation to environmental factors amenable to interventions.

OBJECTIVES: To assess the impact of potentially modifiable environmental factors on the risk for pedestrian and cyclist injuries among school age children. SETTING: Population of school age children in Düsseldorf (population 570,000) in the west of Germany. All pedestrian and cyclist injuries involving children between 6 and 14 years brought to the attention of the police between January 1993 and March 1995 were eligible. METHODS: A case-control design was used, with controls matched by age and sex. Criteria for inclusion of cases were: residence in Düsseldorf, and injury within 500 meters from home. A random sample of 174 cases was selected. For each an age-sex matched child, resident in Düsseldorf, was randomly selected from a list of all school age children. The environment within a radius of 500 meters around the homes of cases and controls was analysed by blinded on site investigators. These used a standardized questionnaire to assess the number of streets with speed limits of 30 kph, the number of pedestrian crossings with traffic lights per street with speed limits of 50 kph or above, and the number of playgrounds for children. RESULTS: Complete information was available for 170 cases and 168 controls. There were significantly more streets with a speed limit of 30 kph around the homes of controls (p = 0.0003; mean 9.5; 95% confidence interval (CI) 8.8 to 10.1) than cases (mean 7.8; 95% CI 7.3 to 8.3). For every five streets with a speed limit of 30 kph injury risk was reduced by nearly 50% (odds ratio 0.57; 95% CI 0.43 to 0.76). There were also significantly more pedestrian crossings with traffic lights on streets with a speed limit 50 kph or above around the homes of controls (p = 0.0004; mean 2.7; 95% CI 2.4 to 2.9) compared with cases (mean 2.1; 95% CI 1.9 to 2.3). Finally there were significantly more playgrounds around the houses of controls (p = 0.04; mean 1.9; 95% CI 1.7 to 2.2) compared with the houses of cases (mean 1.7; 95% CI 1.4 to 2.0). CONCLUSIONS: Significant associations with injury risk were identified for some prespecified modifiable environmental factors.

Accident Prevention↗
PubMed1998

[Challenges in pediatric primary prevention in childhood].

In the Federal Republic of Germany the regulations for primary care in community paediatrics are not uniform in the different German states. Some states have reduced their services for community paediatrics dramatically. Such reductions in primary care for children appeal to many German states, who almost all face major deficits in the state budget. Such reductions will be a threat to child health in Germany unless these services are offered from other non-state agencies. This is not the case. Three examples of deficits in paediatric primary care are given and the potential role of community paediatrics to compensate is discussed. The examples given relate to injury prevention, vaccination and child abuse. Parent counselling regarding age-specific injury risks for infants and toddlers is not systematically offered in Germany. The vaccination coverage for measles e.g. is only 80% and below allowing for some 5 to 10 annual deaths from measles encephalopathy in Germany. Although primary care physicians in Germany are competent to recognize child neglect and abuse therapy is often hampered by the absence of a network of coordinated therapeutic facilities. These examples constitute a challenge to community paediatrics in Germany.

Child↗
PubMed1988

Congenital anaplastic astrocytoma with favorable prognosis. Case report.

A large intracranial tumor that caused macrocrania leading to dystocia was demonstrated by prenatal ultrasound examination. After birth, computerized tomography (CT) confirmed the presence of a giant supratentorial tumor with a large cyst. When the infant was 20 days old, the tumor was radically extirpated. Neuropathological examination revealed an astrocytoma with focal signs of anaplasia showing a macrocyst as well as multiple microcysts resulting from hemorrhages into the tumor. Although no adjuvant radio- or chemotherapy was administered, the child had nearly normal psychomotor development without clinical or CT evidence of tumor recurrence, and is now 3 years old.

Astrocytoma↗
PubMed1986

[Abortion according to paragraph 218ff. of the German penal code and life support of premature infants from the viewpoint of the pediatrician].

The actual reality of abortion in the Federal Republic of Germany is shocking: in 1984, 100 000-340 00 abortions took place. In contrast to the goals established in the reform of criminal law in Para. 218ff. (StGB) from 1976, unborn life is not protected. Moreover, for "social indications" abortion is being carried out more and more frequently, which results in the killing of new life. Even if the basic laws seem to provide unborn life with a high measure of protection, court decisions regarding abortion according to Para. 218ff. (StGB) indicate that in practice, there is very little protection. The so-called "test-tube baby" enjoys more legal protection than the child begotten in the natural manner. To a certain extent, the paediatrician is confronted with demands to save life. Prematures with a very low birth weight should be kept alive. According to the 1984 records of the Federal Office for Statistics, in the Federal Republic of Germany an average of 147.9 abortions were performed per 1000 children born. For the most part the abortions were performed on account of social indications. Since life begins when the sperm and egg fuse, which is also recognized by basic law 14 days after conception, the paediatrician in particular must feel himself responsible for life yet unborn. However, the paediatrician must also stand up for the disabled child and its right to life, because Para. 218ff. did not intend to eliminate disabled children from society.

Abortion, Induced↗
PubMed1985

[Progressive-septic granulomatosis: improved prognosis with early diagnosis and targeted therapy. Report of 5 cases].

The clinical and laboratory findings in chronic granulomatous disease are illustrated by five case reports. Biochemical studies of the neutrophil bactericidal defect have revealed several molecular forms of the disease. Specific therapeutic action is nowadays possible, after early diagnosis of the condition by nitroblue-tetrazolium test and chemiluminescence. Infections are treated using antibiotics and antimycotics which penetrate well into granulocytes; additional surgical intervention or granulocyte transfusion may be necessary. Prolonged infection-free periods are achieved under prophylactic sulfamethoxazole/trimethoprim therapy, promising an improved prognostic outlook for patients with chronic granulomatous disease.

Adult↗
PubMed1981

The clinical relevance of factor VIII: C and factor VII R: Ag determination in newborns.

Higher levels of factor VIII: C and factor VIII R: Ag were found in healthy newborns (n = 60) as compared to adults. This could be explained as a stress reaction due to birth and the adaptation to extrauterine life. A further stress factor is disease. The highest values for factor VIII R: Ag were found in ill (n = 32) and in severely ill newborns (n = 21). The large ranges of factor VIII: C and of the ratio of factor VIII: C/VIII R: Ag in healthy newborns can be explained by an increased turnover of coagulation factors. Diseases in the newborn period lead to an increase of this process, resulting in even larger ranges of factor VIII: C and of the ratio of factor VIII: C/VIII R: Ag in ill and extremely ill newborns. Consumption of factor VIII: C with a low ratio of factor VIII: C/VIII R: Ag predominates in extremely ill newborns. The ratio of factor VIII: C/VIII R: Ag is more valuable than factor VIII: C for diagnosis of DIC in newborns. A diagnosis of hemophilia and von Willebrand's disease cannot be established with certainty in severely ill newborns. Stress and DIC may influence the characteristic changes of laboratory parameters.

Antigens↗
PubMed1981

[Temporal bone histopathology in a case of trisomy 22-syndrome (author's transl)].

This premature female infant died soon after birth. She had numerous gross anomalies and was found on cytogenic studies to have Trisomy 22. Polytomographic and histologic studies of the left ear revealed multiple anomalies including complete aural atresia, non-pneumatization of the middle ear with a vertical shelf of bone in the mid portion of the middle ear, absence of the stapes and oval window and bony closure of the round window niche. The cochlea is flat in shape and shows one and a half turns with incomplete formation of the modiolus. The intersaccular septum is rudimentary but the spiral ganglion is clearly seen in Rosenthal's canal through the one and a half turns. The organ of Corti is well developed and contains hair cells. The stria vascularis is present. The utricular and saccular maculae as well as all cristae are well developed and contain hair cells. The saccular wall is collapsed onto an atrophic appearing otolithic membrane. The utricle is dilated, the lateral semicircular canal appears short and the bony canal is wide. The flattened and shortened cochlea with deformities of the cochlear duct, and the large vestibule resembles Mondinis dysplasia.

Abnormalities, Multiple↗