Search PubMed⌕ Search

Biomedical subjects

W Berger

Publications and source records attributed to W Berger.

At least 163 records · Page 9Linked to original sources
PubMed1990

Slowing of high-speed memory scanning in Parkinson's disease is related to the severity of parkinsonian motor symptoms.

High-speed memory scanning (Sternberg paradigm) was tested in a collective of 20 parkinsonian patients (10 newly diagnosed, untreated patients, duration of the disease 0.5-3.8, mean 1.5 years; 10 levodopa-treated patients, duration of the disease 4.2 to 11, mean 7.6 years). The levodopa-treated patients stopped taking levodopa before the test. There was a tendency towards retarded memory scanning in the patients' collective compared with 20 healthy controls with similar ages and verbal IQs (p = 0.076, Mann-Whitney U test). The mental slowing correlated significantly with bradykinesia and the sum-score of the Columbia University Parkinson Rating Scale (p = 0.021 and 0.019; Spearman rank correlation). Kruskal-Wallis ANOVA revealed a significant mental slowing in the subgroup of patients with Parkinson's disease for greater than 4 years compared with the newly diagnosed patients and the controls (H = 8.54; p = 0.019 and 0.006, Mann-Whitney U test). The findings suggest a mental slowing in Parkinson's disease, which is associated with the progression of parkinsonian motor symptoms and not with depression.

Aged↗
PubMed1990

Knowledge of hemodialysis and CAPD patients about their prescribed medicines.

A questionnaire was designed to determine and compare the extent of knowledge of 40 continuous ambulatory peritoneal dialysis (CAPD) and 40 hemodialysis (HD) patients about their medicines. It was administered orally to outpatients attending a clinic by an investigator unknown to the patients. Data were collected pertaining to the following target drugs: calcium supplements, phosphate binders, vitamins B and C and folic acid. HD and CAPD groups were closely matched for age and sex. Sixty percent of CAPD and 49% of HD patients were taking four or more medications. The dose of folic acid was accurately recalled by 91% and 71% of CAPD and HD patients. Indications for calcium supplements and phosphate binders were known by only 8% and 30% of CAPD patients compared to 72% and 73% of HD patients. More HD patients knew the indications for all target drugs (p less than 0.01). More CAPD than HD patients knew the expected duration of therapy (p less than 0.01). There was a trend between decreased knowledge of whether the medication was working with increasing age of CAPD patients. Most drug information was supplied by physicians, but many CAPD patients (21%) obtained information from lay sources. When given the opportunity to ask questions about their medicines, only 56% CAPD and 46% HD patients did so. The knowledge of CAPD and HD patients studied was grossly deficient in terms of indications, effectiveness, duration and action to be taken if doses were missed.

Adult↗
PubMed1990

[Practical aspects of intensified insulin therapy using the basal bolus principle].

In type 1 (insulin-dependent) diabetic patients, a good metabolic control can often be achieved only by means of an intensified insulin-giving regimen. This requires multiple insulin injections, whereby 60 to 70% of the total daily insulin amount are administered as preprandial boli of short or intermediate acting insulin. The remaining 30 to 40% of the daily insulin dosage are usually given as bedtime injection. With this form of therapy, sufficient metabolic control can be achieved in the majority of patients; however, due to the kinetics of subcutaneously injected insulin, there are some limitations to this therapeutic regimen. Physiological overnight insulin requirements, i.e. relatively small insulin requirement during the first part and increased insulin requirement during the second part of the night, are difficult to meet with currently available insulin preparations. It is, therefore, nearly impossible to achieve euglycemic fasting blood glucose levels without taking the risk of nocturnal hypoglycemia. Moreover, intensified insulin therapy requires regular selfmonitoring of blood glucose, and the patients have to stick to a quantitative diet and to a relatively fixed time schedule for meal ingestion. Several practical aspects as to the time and site of injection, postponing or "skipping" meals, etc., are discussed.

Delayed-Action Preparations↗
PubMed1990

[Clinical significance, diagnosis and treatment of diabetes in pregnancy (gestational diabetes)].

Early diagnosis of glucose intolerance by glucosuria testing is unreliable and should be replaced by blood sugar screening in the 24th to 28th week of gestation. If screening results are pathological (blood sugar in capillary whole blood over 140 mg% one hour after oral ingestion of 50 g glucose), a standardized glucose tolerance test should be performed. This screening test will reveal a glucose intolerance in approx. 3% of pregnant women. High-risk patients for gestational diabetes (previous pregnancies, complicated by gestational diabetes, family history of diabetes mellitus (first degree relatives), obesity (greater than 120% of ideal body weight), maternal age greater than 30 years, unexplained stillbirths) should have their glucose tolerance checked in early pregnancy, possibly before conception, but also in the 32nd to 36th week, if blood sugar screening is normal in weeks 24 to 28. If the glucose tolerance test is abnormal, blood sugar values must be controlled by diet on levels below 5 mmol (90 mg%) and postprandial below 7 mmol (126 mg%), measured in capillary whole blood. If these values are higher, an insulin treatment has to be discussed, since high blood glucose values result in an increased risk of infant morbidity and mortality. During insulin treatment, it might be possible that higher doses become necessary in order to avoid fetal hyperinsulinism with consecutive macrosomy. Although after childbirth often a normal glucose tolerance is noted, a manifestation of diabetes within the next 20 years will occur in one third of all gestational diabetics. Regular control of the glucose tolerance, e.g. in yearly intervals, as well as preventive measures (regulation of body weight) are indicated.

Combined Modality Therapy↗
PubMed1989

Compensation of translational and rotational perturbations in human posture: stabilization of the centre of gravity.

EMG responses in the leg muscles, head acceleration and joint movements induced by dorsiflexing rotation of the ankle have been analysed. Perturbations were induced while subjects were standing on a platform with the ankle joints co-linear with the axis of rotation or while standing above the axis (between 5 and 25 cm), which introduced an additional translational component to the displacement. The former condition was followed by a monosynaptic gastrocnemius reflex potential and a late tibialis anterior activation (latency about 100 ms); in the latter condition the monosynaptic reflex response became smaller and a longer latency gastrocnemius response (latency about 70 ms) appeared, the strength and duration of which increased in parallel with the translational component, while the amplitude of the tibialis anterior activity decreased. Neither vestibulospinal nor muscle proprioceptive mechanisms can solely account for this effect as the biomechanical parameters were little changed in the different conditions. It is suggested that the controlled variable in the investigated task is to hold the bodies' centre of gravity over the feet which makes the change in the pattern meaningful: pure dorsiflexion of the feet is followed by a backwards sway of the body, thus a tibialis anterior activation is functionally essential to hold the centre of gravity over the feet. A backwards translation of the feet withdraws the supporting surface, thus a gastrocnemius activation is needed to restore the centre of gravity over the feet. The inhibition of the monosynaptic reflex with increasing translation is suggested to arise from a reciprocal modulation of mono- and polysynaptic gastrocnemius reflex responses.

Acceleration↗
PubMed1989

Warning symptoms of hypoglycaemia during treatment with human and porcine insulin in diabetes mellitus.

32 subjects with long-term insulin-dependent diabetes mellitus (IDDM) were entered into a double-blind, randomised crossover trial with human and porcine insulin. They were treated during both periods with regular insulin and with protamine (NPH) insulin. 18 subjects started with human and 14 with porcine insulin; the two insulin periods each lasted twelve weeks; the insulin doses were much the same in the two periods (mean 23 [SD 9] U daily NPH; 14 [7] U daily regular insulin), as were blood glucose profiles and HbA1c values. There were 171 episodes of hypoglycaemia during human and 150 episodes during porcine insulin. Patients completed questionnaires after each hypoglycaemic episodes and at the end of the trial. Hunger and sweating without concomitant neuroglycopenic symptoms were significantly more frequent as initial warning symptoms during porcine than during human insulin (41% vs 20%), whereas neuroglycopenic symptoms were more frequent during human insulin. At the end of the trial 18 of 32 subjects reported diminished awareness of hypoglycaemia during human insulin compared with 6 of 32 during porcine insulin. Hypoglycaemia developed faster during human than during porcine insulin administration. The transfer of IDDM subjects from porcine to human insulin seems to alter warning symptoms of low blood glucose concentration, with consequent impairment of its early recognition.

Adult↗
PubMed1989

[Nocturnal hypoglycemia with reference to hormonal counterregulation in type I diabetics receiving insulin therapy].

Frequency, symptomatology and risk factors for nocturnal hypoglycemia were investigated in 77 type 1 diabetics. The patients were hospitalized overnight after a normal working day and were kept on their usual insulin regimen. Nocturnal blood sugar levels less than 2.8 mmol/l were found in 25% of 77 patients. In most cases the hypoglycemic event was not noticed by the patients. Additionally, nocturnal hormonal counterregulations were investigated in 22 patients. Plasma adrenalin, noradrenalin, somatotropin, cortisol and glucagon were measured every 2 hours. Although most of the patients were asymptomatic, a significant increase in plasma adrenalin was observed during hypoglycemia episodes. On the other hand, the increase in noradrenalin and somatotropin concentration was not significant. Blood sugar levels of 5 mmol/l and lower at 22 p.m. and at 7 a.m. (as well as diabetes duration) were identified as risk factors for nocturnal hypoglycemia. Nocturnal hypoglycemia occurs irrespective of the amount of insulin injected in the evening or at bedtime. Similarly, neither the time of late insulin injection nor the degree of metabolic control as assessed by HbA1c differed in patients undergoing hypoglycemic episodes and patients without hypoglycemia.

Adult↗
PubMed1989

RFLP-discordance within the human phenylalanine hydroxylase locus.

A search for crossover events was performed in seven families with two phenylketonuria-affected children applying seven enzymes for the detection of eight restriction fragment length polymorphisms (RFLPs) by hybridisation with a human phenylalanine hydroxylase (PAH) cDNA probe. A discordance was detected within the PvuIIb-RFLP pattern of two affected sibs. This observation is most likely the result of a cross-over event in the PAH locus. Alternative explanations are discussed. Non-paternity could be excluded by DNA fingerprinting using the oligonucleotide probe (GTG)5.

Crossing Over, Genetic↗
PubMed1989

Significance of proprioceptive mechanisms in the regulation of stance.

Compensatory electromyographic (EMG) responses and several biomechanical parameters were studied following impulsive disturbance of the limbs during stance of human volunteers on a treadmill. Treadmill acceleration impulses were backwards or forwards directed, or their initial direction was reversed after 30 ms. Backwards directed impulses were followed by gastrocnemius, forwards directed ones by tibialis anterior EMG responses (latency 65 to 75 ms) whose durations depended on impulse duration. When the direction of the impulse was reversed, the respective antagonistic leg muscles were activated again with a delay of 68 to 75 ms after onset of stretch of these muscles. The behaviour of the EMG responses could best be correlated to the displacement at the ankle joint and may be described in terms of a stretch reflex response. The results indicate that these stretch reflex responses help control of the body's centre of gravity thereby preventing falling. Head movements induced by the impulses showed little correlation with the appearance of the EMG responses, suggesting that the vestibular system is unlikely to be directly involved in the generation of these responses. Vestibular signals may, however, significantly contribute to slow body sway stabilization.

Adult↗
PubMed1989

Perturbations of human posture: influence of impulse modality on EMG responses and cerebral evoked potentials.

Leg muscle EMG responses and cerebral evoked potentials (CP), elicited by perturbations of stance while on a treadmill with split belts, were analyzed in order to study the relationship between compensatory leg muscle responses and afferent input to supraspinal centers. Various conditions of perturbation were used to establish the extent to which compensatory EMG responses and CPs show congruent behavior. Four different treadmill acceleration rates were applied in three different conditions (unilateral perturbation, directed forward or backward; bilateral perturbation, directed forward or backward; and opposing bilateral perturbation). EMG responses and CPs showed parallel increases in amplitude with increasing displacement velocity. The EMG responses showed distinct differences, predominantly in the response amplitude, between the different perturbation conditions, whereas the CPs were affected only to a minor degree. Tibialis anterior EMG responses were more closely related to the CP following forward perturbation than the corresponding gastrocnemius responses were to the CP following backward perturbation. We conclude that the EMG responses are more closely related than the CPs to displacement parameters and suggest that this is due to the further spinal processing of the afferent input needed to generate an appropriate EMG response. The closer relationship between the tibialis anterior response and CP may reflect a predominant central representation and control of tibialis anterior activation in the regulation of posture. The functional implications of these findings are discussed.

Journal Article↗
PubMed1989

Interlimb coordination of leg-muscle activation during perturbation of stance in humans.

1. Electromyographic (EMG) responses were recorded in both legs, along with corresponding joint movements, after uni- and bilateral perturbations during stance on a treadmill with split belts. Displacements were directed forward, backward, or in opposing directions. They were induced by randomly timed ramp impulses at one of four different rates of treadmill acceleration. 2. Unilateral perturbations directed backward were followed by a bilateral gastrocnemius-EMG response, forward-directed perturbations by a bilateral tibialis anterior-EMG response. The amplitude of these responses was dependent on the rate of treadmill acceleration. Relative to the response of the displaced leg, the amplitude of the EMG response on the nondisplaced side was smaller when a gastrocnemius EMG response was induced, and about equal when the tibialis anterior muscle was activated. The onset latencies were shorter on the displaced side (displaced leg 75-96 ms, non-displaced leg 93-112 ms). 3. Bilateral perturbations in one direction were followed by larger EMG responses in both legs (in the gastrocnemius for backward-directed impulses, in the tibialis anterior for forward-directed impulses). For a given acceleration rate, their amplitude was about equal to the sum of the EMG amplitude of the displaced leg and that of the nondisplaced leg obtained during unilateral displacement. The inverse result was obtained when the legs were simultaneously displaced in opposite directions: EMG responses in both legs were significantly smaller than those obtained after unilateral displacement. 4. It is concluded that a unilateral displacement evokes reflex EMG responses in the synergistic muscles of both legs, which are graded according to the size of the proprioceptive input from the primarily displaced joint. During bilateral displacements, the activity induced by the respective contralateral leg is linearly summed or subtracted, depending on whether the legs are displaced in the same or in opposite directions. In view of the short latencies of these bilateral responses, it would seem that they are mediated by a spinal mechanism. 5. Distinct differences in the behavior of the antagonistic leg muscles were observed: 1) the coactivation of the contralateral leg muscle was significantly smaller when the gastrocnemius was stretched unilaterally, whereas it was about equal for the tibialis anterior; and 2) the gastrocnemius EMG responses were closely correlated with the displacement velocity, whereas the tibialis anterior response was more closely correlated with acceleration, i.e., the tibialis anterior response was more dynamic in nature.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

Iotrolan, a nonionic dimeric contrast medium in myelography.

As part of a clinical Phase III study of the nonionic, dimeric contrast medium iotrolan, differences in opacification, tolerance, and effects on the electroencephalogram after myelography were examined in a double-blind comparison with iohexol. Two groups of 25 patients each received either 10 ml iotrolan 240 mg I/ml or 10 ml iohexol 240 mg I/ml for lumbar myelography, and two groups of 50 patients each received either 10 ml iotrolan 300 mg I/ml or 10 ml iohexol 300 mg I/ml for lumbar, thoracic or cervical myelography. The overall assessment of the opacification in the subarachnoid space, which was moderate in only one case of each group and otherwise good, showed no differences between the preparations. The tolerance of both concentrations of iotrolan proved to be significantly better than those of iohexol: at a significance level in the chi-square test of p less than 0.001 in a simple size of 25 patients per preparation with 240 mg I/ml and at a significance level of p +/- 0.05 in a sample size of 50 patients per preparation with 300 mg I/ml.

Adult↗
PubMed1989

[Current technics in the improvement of insulin treatment].

Circumstantial evidence from clinical observations indicates an association between the degree of blood glucose control and the occurrence of diabetic microvascular complications. Therefore, intensified insulin treatment regimens directed at maintaining blood glucose concentrations in the normoglycemic range have been developed. In the past years, several techniques to facilitate intensified insulin delivery, including insulin pumps and pen injectors, have been invented. The widespread use of these devices necessitates, however, that the patients are properly educated, in order to avoid severe hypoglycemia and ketoacidosis. In the present review, the advantages and shortcomings of these new devices are discussed.

Blood Glucose↗
PubMed1988

[Intensified insulin therapy in Type 1 diabetes. Results of a 1-year treatment using the basic-bolus principle in hard-to-control diabetic patients].

Thirty-six adult type 1 diabetics, whose metabolic control was unsatisfactory on conventional insulin treatment or on continuous subcutaneous insulin infusion, were treated for an average of 13 months by the basis-bolus insulin regimen using pen-like insulin injectors. HbAlc-values improved from 8.1% before to 6.7% at the end of the observation period, with the same daily injected amount of insulin (39 +/- 2 IU/d before, 38.7 +/- 2 IU/d after switching to the new regimen). The number of hypoglycemic events did not increase with the new insulin regimen. Acceptability was good. Flexibility as to the timing of meals and easy handling of the device were considered the main advantages of the new system. Some patients were bothered by the need for intensified self-monitoring of blood glucose. The insulin regimen according to the basis-bolus principle using pen-like injectors led to an improvement of both metabolic control of the patients and their quality of life. It is, however, mandatory that they are properly instructed and willing to perform regular home monitoring of blood glucose.

Adult↗
PubMed1988

Involvement of different receptors in the regulation of human posture.

Compensatory electromyographic (EMG) responses and several biomechanical parameters were studied following impulsive disturbance of the lower limbs during stance on a treadmill. Treadmill acceleration impulses were backwards or forwards directed, or their direction was inverted after 30 ms. Backwards directed impulses were followed by gastrocnemius and forwards directed ones by tibialis anterior EMG responses (latency 65-75 ms) whose duration depended on impulse duration. When the direction of the impulse was inverted, the respective antagonistic leg muscles were activated, with a delay of 68 to 75 ms after onset of stretch of these muscles. The behaviour of the EMG responses could best be correlated to the displacement at the ankle joint and may be described in terms of a stretch reflex response. The function of this stretch reflex mechanism is suggested to be connected with the control of the body's centre of gravity in order to prevent falling. Head movements induced by the impulses showed little correlation with the appearance of the EMG responses, suggesting that the vestibular system is unlikely to be significantly involved in the generation of these responses.

Biomechanical Phenomena↗
PubMed1988

[Infantile form of nemaline (rod inclusion) myopathy].

This paper reports the first Austrian case of infantile nemaline myopathy in a girl aged 19 years, presenting with congenital skeletal dysplasia, reduced body weight and slowly progressive limb girdle muscular atrophy, myopathic face and difficulty in swallowing. Electromyography revealed a combination of myopathic and neurogenic lesions, while electron microscopy of a muscle biopsy established the diagnosis. The patient's mother and two elder brothers showed no clinical features of the disease, but neurophysiological abnormalities were present, indicating an asymptomatic form of illness. The aetiology and pathogenesis of nemaline myopathy are unknown, but neurogenic factors cannot be excluded.

Adult↗