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Biomedical subjects

G Haas

Publications and source records attributed to G Haas.

At least 73 records · Page 4Linked to original sources
PubMed1989

Development of feedback and feedforward control of upright stance.

Feedback and feedforward (anticipatory) adjustments of stance were investigated in 58 children with normal development aged between seven months and 14 years, and in 14 children with motor and mental retardation aged between 21 months and seven years. Feedback responses after tilting the body were elicited in all but the two youngest children, aged seven and nine months. The observed rapid decrease in feedback response latency with age suggests considerable acceleration of central transmission. Effective anticipatory postural adjustments (feedforward) were elicited only in the normal children over four years of age. The development of both feedback and feedforward continued until adolescence.

Adolescent↗
PubMed1989

Ensuring data quality in a multicenter clinical trial: remote site data entry, central coordination and feedback.

In an ongoing multicenter clinical trial, "Treatment Strategies in Schizophrenia," the five participating sites have the capacity to perform a variety of tasks or study functions independently. These tasks include (a) verification of diagnostic eligibility through the use of computerized decision algorithms; (b) assignment of patients to treatment based on prognostic indicators using a computerized randomization algorithm; (c) entry of data into a microcomputer using a clinical trial data management system that performs simple range and missing data item checks; and (d) regular transfer of all data to the central coordinating team. The clinical trial data management system employed allows for both independent site functioning and assurance of consistency across sites. The integration of a variety of software outside the main data management system provides the central coordinators with the tools to monitor critical data as it is collected, as well as the capacity to assess the flow, quality, and uniformity of the ongoing trial.

Clinical Trials as Topic↗
PubMed1989

Monitoring fluid shifts in humans: application of a new method.

Using the "mechanical oscillator technique," the mass density of antecubital venous blood and plasma samples was measured 5-20 times in order to study the influence of postural changes (gravity dependence) on human blood mass density with 0.01 g.L-1 precision, while performing tilt table tests in 17 men. Hemoglobin concentration was measured in 10, and hematocrit in all subjects. Postural fluid shifts were mirrored by accompanying changes in all variables. Blood density (BD) was monitored continuously in five additional experiments from one vein each using two independent densitometers. There were linear relations (p less than 0.01) between all possible combinations of BD, plasma density (PD), blood hemoglobin concentration (Hb), and hematocrit (Ht). Hb can be directly computed from BD (range +/- 10%); the accuracy of Ht determinations from BD increases (range +/- 0.02) if the individual erythrocyte density (ED) and the sample PD are used for calculation. ED was calculated and did not change with body position. ED values of different persons ranged between 1085 g.L-1 and 1095 g.L-1 and did not vary in 15 out of 17 individuals with time (5-75 d). We conclude that ED is closely regulated to an individual set point, that Ht can be computed from BD with higher accuracy if the individual ED and the actual PD values are known, and that BD allows for direct Hb calculation. On-line BD monitoring can be performed with high precision and reveals the individual time-course of spontaneous and postural capillary fluid shifts.

Adult↗
PubMed1987

Relationship between lesion extent in 'Wernicke's area' on computed tomographic scan and predicting recovery of comprehension in Wernicke's aphasia.

This study investigated the relationship between severity of auditory comprehension in Wernicke's aphasia and amount of temporal lobe damage within Wernicke's area (posterior two thirds of superior temporal gyrus region) as well as the total temporoparietal lesion size. There was a highly significant correlation between comprehension and the amount of temporal lobe lesion in Wernicke's area. There was no significant correlation between comprehension and the total temporoparietal lesion size. Patients with damage in only half or less than half of Wernicke's area had good comprehension at six months after the onset of stroke. Patients with damage in more than half of Wernicke's area had poor comprehension even one year after the onset of stroke. Additional anterior-inferior temporal lobe lesion extension into the middle temporal gyrus area was associated with particularly poor recovery.

Aged↗
PubMed1987

Magnetic resonance imaging of the brain of children with multiple sclerosis.

The results of magnetic resonance imaging (MRI) of the brains of three children with multiple sclerosis were compared with the results of computer tomography (CT). MRI made it possible to detect a particular configuration of white-matter hyperintensities with sharply angled patches and a multifocal pattern, even during remission. Thus the site and extent of cerebral plaques could be demonstrated more clearly and more exactly than with CT. At present MRI seems to be the most reliable method for confirming suspected cases of multiple sclerosis in childhood.

Brain↗
PubMed1987

Clinical nonrecognition of neuroleptic-induced movement disorders: a cautionary study.

Extrapyramidal side effects are a major limitation in the use of neuroleptics, and tardive dyskinesia is a special public health problem. Accurate clinical diagnosis of extrapyramidal syndromes is necessary for effective management. The authors compared clinicians' recognition of the major extrapyramidal syndromes in 48 psychotic inpatients with independent blind diagnoses by clinical researchers using standardized ratings. The major finding was a high rate of clinical underrecognition of all major extrapyramidal syndromes, especially tardive dyskinesia. The authors discuss the clinical predictors of nonrecognition of extrapyramidal side effects and recommend improved training in their detection.

Akathisia, Drug-Induced↗
PubMed1987

[Measuring cis-dichlorodiamino platinum(II) concentrations in human blood and mouth mucosa].

Using the method of atomic absorption spectroscopy, platinum (DDP) concentrations were determined in tissue samples and plasma from 10 patients who suffered from a squamous cell carcinoma and were receiving cis-platinum. The drug was administered by a rapid infusion (60 mg/m2). Tissue samples and plasma were collected 5 h after infusion. Platinum concentrations found in squamous cells of the oral cavity varied from 3 to 20 micrograms/g with a median concentration of 7.5 micrograms/g. The corresponding plasma concentrations were 1.5-2.5 micrograms/ml. The data suggest that within 5 h after infusion an enrichment of cis-platinum takes place in human tissue.

Cisplatin↗
PubMed1986

Development of postural control in children: short-, medium-, and long latency EMG responses of leg muscles after perturbation of stance.

Short (SL), medium (ML), and long (LL) latency EMG responses of leg muscles were recorded after perturbation of stance by means of a sudden toe-up tilt of a movable platform. 56 healthy children varying in age between 14 months and 15 years were investigated. All three responses were present when children were able to stand on the recording platform. The SL-response in the triceps surae muscle, which corresponds to the mono- and oligo-synaptic spinal stretch reflex, showed a decreasing latency up to the age of 5 years. This reflects the increasing peripheral nerve conduction velocity. The ML-response in the triceps surae muscle, which as the SL-response has no stabilizing effect in this experiment, showed somewhat delayed maturational changes. The LL-response in the relaxed anterior tibial muscle helps to restore upright posture even in the youngest children. Its maturational changes in terms of latency by far exceed the range that can be explained by the increase of peripheral and spinal conduction velocities. Its mechanisms of maturation, besides the biophysical optimalization of a polysynaptic network, may include learning in terms of selecting the shortest pathways by way of synaptic potentiation within structures involved in the supposedly transcortical pathway of the LL-response. Qualitative observations made during the trials showed that the pattern of postural adaptation changed with age, suggesting the development of additional intersegmental mechanisms.

Adolescent↗
PubMed1986

Improved outcome in very low birth weight infants from 1977 to 1983.

Changes of mortality and neurological morbidity in 351 very low birth-weight infants cared for in the neonatal intensive care unit of the Children's Hospital Tübingen during the years 1977 to 1983 are reported. The main finding was a survival rate increasing from 69.5% in 1977-79 to 76.6% in 1982-83 and a coinciding frequency of severe neurological sequelae decreasing from 9.2%-3.7%. The incidence of minor neurodevelopmental problems remained unchanged. However, mortality after discharge was found to be increased during the period observed. In conclusion, the intensification of neonatal intensive care in our hospital did not only reduce mortality but also the rate of severe neurological sequelae, thus not only survival rate but also the quality of survival could be improved.

Germany, West↗
PubMed1986

Obstetrical and neonatal risk factors in very low birth weight infants related to their neurological development.

An analysis of pre- and perinatal risks in very low birth weight (VLBW) infants showed that children later suffering from severe neurodevelopmental sequelae were exposed to a significantly higher number of risk factors compared to normally developed VLBW controls. This was not only due to a higher incidence of specific risks, but to the accumulation of risk factors, which consequently made an ischaemic or haemorrhagic brain lesion more likely to occur. This result suggests that brain lesions in VLBW infants are essentially multifactorial. The improved outcome of VLBW infants cared for in the NICU of the Children's Hospital of Tübingen during 1977-1983 was accompanied by a decreasing incidence of obstetrical and neonatal risks. This was mainly due to more frequent transport in utero, earlier obstetrical intervention, and immediate postnatal stabilization of the infant's condition. These changes in perinatal care strategy evidently favoured the postnatal course and thus also improved the neurodevelopmental outcome.

Female↗
PubMed1986

The organization of the rat motor cortex: a microstimulation mapping study.

In conclusion, the rat primary motor cortex appears to be organized into irregularly shaped patches of cortex devoted to particular movements. The location of major subdivisions such as the forelimb or hindlimb areas is somatotopic and is consistent from animal to animal, but the internal organization of the pattern of movements represented within major subdivisions varies significantly between animals. The motor cortex includes both agranular primary motor cortex (AgL) and, in addition, a significant amount of the bordering granular somatic sensory cortex (Gr(SI)), as well as the rostral portion of the taste sensory insular or claustrocortex (Cl). The rat frontal cortex also contains a second, rostral motor representation of the forelimb, trunk and hindlimb, which is somatotopically organized and may be the rat's supplementary motor area. Both of these motor representations give rise to direct corticospinal projections, some of which may make monosynaptic connections with cervical enlargement motoneurons. Medial to the primary motor cortex, in cytoarchitectonic field AgM, is what appears to be part of the rat's frontal eye fields, a region which also includes the vibrissae motor representation. The somatic motor cortical output organization pattern in the rat is remarkably similar to that seen in the primate, whose primary, supplementary and frontal eye field cortical motor regions have been extensively studied.

Animals↗
PubMed1986

Sentence level auditory comprehension treatment program for aphasic adults.

The purpose of this study was to investigate whether a newly developed sentence level auditory comprehension (SLAC) treatment program could be used to improve language comprehension test scores in adults with chronic aphasia. Results indicate that the SLAC treatment program can be used with chronic patients; performance on a standardized test (the Token Test) was improved after treatment; and improved performance could not be predicted from either anatomic CT scan lesion sites or pretreatment test scores. One advantage to the SLAC treatment program is that the patient can practice listening independently with a tape recorder device (Language Master) and earphones either in the hospital or at home.

Aphasia↗
PubMed1985

Development of a scale for measuring techniques in the psychotherapy of borderline patients.

Studies of psychodynamic psychotherapy require an instrument to measure the application of the prescribed therapeutic techniques during ongoing treatment. The authors describe the development of such an instrument, the Therapist Verbal Intervention Inventory (TVII), designed specifically for use in the study of the treatment of patients with borderline personality disorders. The TVII was designed, in addition, to test the hypothesis that psychodynamic techniques defined at a middle level of inference could be reliably rated by trained clinicians. The authors present data on the inter-rater reliabilities and inter-rater agreements obtainable with the TVII in the hands of highly experienced clinicians and in the hands of an independent group of junior clinicians trained in its use. The TVII appears to be a potentially useful tool for monitoring psychotherapy techniques in ongoing studies of the treatment of patients with severe personality disorders. Psychiatrists at the advanced resident level or immediate postresidency level have been trained to use the TVII to rate videotaped therapy sessions reliably.

Borderline Personality Disorder↗