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W Berger

Publications and source records attributed to W Berger.

At least 145 records · Page 8Linked to original sources
PubMed1992

Mutations in the candidate gene for Norrie disease.

Recently, we and others have isolated a candidate gene for X linked Norrie disease (ND) which was found to be deleted or disrupted in several patients. As a prerequisite for the identification of point mutations in the ND gene we have established the exon-intron structure of this gene. In 17 unrelated patients and 15 controls, PCR products derived from the promoter region, exons 1 and 2 as well as the coding part of exon 3 were analysed with the single strand conformation polymorphism (SSCP) technique. In 12 patients altered PCR fragments were detected which were studied in detail by direct sequencing. Eleven different mutations were found, and all but one are likely to give rise to significant structural changes in the predicted protein. These findings, and the absence of functionally relevant base changes in healthy controls, emphasize the causal role of this candidate gene in Norrie disease and pave the way for reliable diagnosis and carrier detection.

Base Sequence↗
PubMed1992

Nailfold videomicroscopy and local cold test in type I diabetics.

Twenty-five type I diabetics (9 men, 16 women) with a mean disease duration of 19.9 years and 25 sex- and age-matched healthy control subjects were studied. Digital capillary blood flow measurements in combination with a local cooling test were assessed by nailfold videocapillaroscopy using the technique of flying spot and compared with nailfold capillary microscopy in four subgroups divided according to (A) disease duration, (B) retinopathy, (C) fasting blood glucose level, and (D) HbA1c values. Differences in morphologic capillary diameters and capillary density were found between the diabetics and the healthy control subjects. These were attributable to the patients with retinopathy. The hemodynamic findings at rest and after local cooling were unable to differentiate either between type I diabetics and healthy controls or within the different subgroups.

Adult↗
PubMed1992

Elevated proinsulin levels related to islet cell antibodies in first-degree relatives of IDDM patients.

OBJECTIVE: To assess whether proinsulin levels are elevated in first-degree relatives of insulin-dependent diabetes mellitus (IDDM) patients and whether there is a relationship between proinsulin levels and the occurrence of immunological markers. RESEARCH DESIGN AND METHODS: Fasting proinsulin concentrations were measured in 85 first-degree relatives (54 siblings, 20 parents, 11 children) of IDDM patients and in 90 age- and weight-matched control subjects with no family history of diabetes mellitus. RESULTS: Fasting proinsulin levels (median, 25th, and 75th percentiles) were 8 pM (range 3.2-14 pM) in first-degree relatives and 1.7 pM (range 1.7-4 pM) in control subjects (P less than 0.0001). Proinsulin was significantly elevated in siblings (7.2 pM, range 3.8-15 pM; P less than 0.0001), parents (9.8 pM, range 6.4-13 pM; P less than 0.0001), and children (6.6 pM, range 1.8-12 pM, P = 0.04) compared with control subjects but without differences between these groups. Islet cell antibody positive (ICA+) IDDM relatives had significantly higher proinsulin levels than ICA- (16 pM; range 7.2-25 vs. 6.9 pM, range 3.1-12 pM; P = 0.02). There was no difference between individuals with and without insulin autoantibodies. No difference in proinsulin levels was observed if the relatives were subdivided according to HLA-DR sharing with the diabetic proband. CONCLUSIONS: Fasting proinsulin concentrations were raised not only in siblings but also in parents and children of IDDM patients. Because proinsulin is more elevated in ICA+ than in ICA- subjects, increased proinsulin levels could reflect minor beta-cell damage due to previous immunological attack.

Adult↗
PubMed1992

Influence of subjects' height on the stabilization of posture.

In order to investigate the influence of subjects' height in stabilization of body sway, postural EMG reactions were analysed following perturbation of posture during stance on a force measuring platform. Perturbing momenta of different strengths were unexpectedly applied at the back (level of the center of gravity) after being matched to the body weight of each subject. EMG activity of the antagonistic leg muscles and head, hip and ankle joint movements were recorded. There was a close correlation between displacement amplitude at the ankle joint and height of the subject, with the largest displacements in small subjects. The consequence of this relationship was that 1) The compensatory reactions consisted of larger gastrocnemius responses and a stronger coactivation of the tibialis anterior; 2) Momenta of increasing strength resulted in a larger increment of both ankle joint displacement and gastrocnemius EMG responses in small compared to larger subjects. In analogy to tip-toeing movements, it is concluded that the coactivation pattern is typical for stance conditions with a restricted area of support in order to reduce body sway. On the basis of latency measurements it is suggested that the response pattern is induced by proprioceptive information from the impact site of the momentum.

Adolescent↗
PubMed1992

Clinical application of two computerized diabetes management systems: comparison with the log-book method.

In two consecutive studies the clinical application and suitability of two computer-assisted data management systems (Camit and Cadmo) were evaluated in a prospective manner. In each study nineteen long-standing, stable insulin-dependent patients were randomly assigned to one of two groups. In study I assessment of metabolic control and insulin dose adjustments were based either on the Camit S1 data analysis or on the conventional log-book method, whereas in study II the Camit S2 and the Cadmo simulation programs were evaluated. HbA1c values decreased significantly in both studies (p < 0.05). A clear decline in hypoglycemic events as well as a significant reduction of the percentage of glucose values below 4.0 mmol/l (p < 0.005) and a marked increase (p < 0.05) in the percentage of glucose levels in the target range (4.0-10.0 mmol/l) were observed. We found both computerized assessment systems to be reliable and suitable for the assessment of blood glucose control and for insulin dose finding. The graphical and statistical presentation of the numerous glucose and insulin data allowed a better summary of blood glucose control and metabolic trends. More time could be spent for problem solving, which proved to be much less exhausting with the computer for the attending physician. Further studies should address the educational potential of computerized systems for the patient as well as for the physician.

Adult↗
PubMed1991

[The practical assessment of micro-albuminuria as a marker for beginning diabetic nephropathy in: which urine sampling method?].

Microalbuminuria, i.e. elevated urinary albumin excretion rate between 20 and 200 micrograms/min, is a strong predictor of subsequent overt diabetic nephropathy. Screening for microalbuminuria is essential, since it has been shown that development of overt nephropathy can be delayed or even prevented by therapeutic measures such as strict metabolic control, early aggressive antihypertensive treatment, or restriction of protein intake. Several urine collection methods for the measurement of microalbuminuria have been proposed. In a prospective study with 40 diabetic outpatients we have compared albumin excretion in urine collected over 24 h, during a timed overnight period, and in a spot urine sample collected at random while the patient attended the outpatient clinic. In addition, the reproducibility of the three urine collection methods was assessed. For this purpose, each patient underwent 3 consecutive collections at an interval of at least 4 weeks. Our data indicate that calculation of an albumin/creatinine quotient in a spot urine probe is a reliable screening test for microalbuminuria. If this quotient is increased (greater than 2), timed overnight collection should be performed.

Adolescent↗
PubMed1991

High-speed memory scanning in Parkinson's disease: adverse effects of levodopa.

High-speed memory scanning as assessed by the Sternberg paradigm was studied in 12 nondemented patients with fluctuating Parkinson's disease and 13 age-matched healthy controls. Patients were first assessed before taking their morning dose of levodopa ("off") and again after that dose had produced full clinical effect ("on") after that dose had produced full clinical effect ("on"). Although motor components of the measured choice reaction time were slower in patients when off than in control subjects, memory scanning speed was not different. After levodopa (on), patients' motor time normalized, but cognitive processing speed became significantly slower when compared with previous performance in the off condition and with controls. Contrary to previous concepts of bradyphrenia in patients with Parkinson's disease, these results indicate that dopaminergic stimulation can reduce cognitive processing speed.

Frontal Lobe↗
PubMed1991

Reflex activity and muscle tone during elbow movements in patients with spastic paresis.

Reflex behavior and tension development in upper limb muscles were analyzed and comparisons made between the unaffected and spastic sides of patients with spastic hemiparesis. During sinusoidal (0.3-Hz) isometric or isotonic elbow tracking, with a control either of joint position or of torque, randomly timed displacements were induced (at one of three velocities) stretching either the activated flexor or the extensor muscles. On the spastic side, exaggerated short-latency reflexes were apparent, but in contrast, the amplitude of long-latency electromyography (EMG) responses was reduced. The latter responses were differentially modulated on the unaffected side, predominantly by the acceleration signal during control of position and more by the velocity signal during control of torque, while the mode of muscle contraction (isometric or isotonic) had little influence on this behavior. This difference in reflex modulation was lost on the spastic side. The functional consequence of this reduced EMG modulation could be difficulty in performing finely controlled arm movements. The ratio of torque to EMG activity during displacements was higher for both background and reflex-induced EMG on the spastic limb than on the unaffected side. This effect was more pronounced for the flexor than for the extensor muscles. Consequently, the development of spastic muscle hypertonia cannot be attributed to an increase in EMG activity. It is suggested that secondary to a supraspinal lesion, mechanical muscle properties change in such a way that the activated spastic muscle develops more tension when it is stretched.

Adolescent↗
PubMed1990

[Insulin treatment of Type II diabetes].

Secondary failure to oral hypoglycemic agents occurs in some 5% of type II diabetic patients per year, such that treatment with insulin becomes warranted. In most of the cases only hyperglycemia is apparent, while signs of severe metabolic derangement such as thirst, polyuria and weight loss are lacking. However, the hyperglycemic state adversely affects endogenous insulin secretion and favors the development of microvascular complications and neuropathy. In addition, dyslipidemia is often present, and the patient's well-being may be impaired. To differentiate between real secondary drug failure and transient metabolic impairment due to insufficient compliance with the diet prescriptions, plasma C-peptide should be measured. Insulin therapy should be initiated with a dose of 6-8 IU of an intermediate-action preparation and subsequently adjusted based on blood glucose measurements. Frequently it will be necessary to employ twice daily a mixture of (rapid- and intermediate-action) insulin in order to achieve adequate control of postprandial hyperglycemia. In some cases insulin therapy can be discontinued since the endogenous insulin secretion may improve during insulin treatment. We do not recommend to use as initial therapy of patients with secondary failure to oral hypoglycemic agents a combination of sulfonylureas and insulin since the 'insulin-saving' effect is small and not cost-effective.

C-Peptide↗
PubMed1990

[Human insulin and hypoglycemia].

It has been reported over the last few years that transferring diabetic patients from animal to human insulin can lead, in some of the patients, to a diminution of the classical hypoglycaemic symptoms, as hunger and sweating, and to the more frequent occurrence of neuroglycopenic symptoms, as the first manifestation of hypoglycaemia. These changes seem to involve a fraction of patients estimated between 8 and 36%, depending on the type of selection of the patients. A decrease in the adrenergic counterregulatory response to hypoglycaemia has also been shown in some studies with human insulin. Similar changes in the sequence of hypoglycaemic symptoms are also described in various clinical conditions--as intensive insulin therapy with tight glycaemic control, long diabetes duration and presence of autonomic neuropathy, thus acting as confounding factors. According to these facts, a few recommendations are proposed: briefly, human insulin should only be prescribed to new patients who are able to learn from the very beginning the sequence of hypoglycaemic symptoms with human insulin; patients already treated with porcine insulin should not be transferred to human insulin. On the whole, studies available to date have not shown an increased frequency of severe hypoglycaemia with human insulin; however, this important matter still has to be conclusively clarified through well-designed prospective studies.

Autonomic Nervous System↗
PubMed1990

Significance of dopamine receptor antagonists in human postural control.

The purpose of this study was to investigate the effect of different dopamine receptor antagonists on the function of proprioceptive reflex mechanisms involved in the regulation of stance and gait. Haloperidol as preferential D2 and the 'pure' dopamine D2 receptor antagonist sulpiride significantly reduced the level of the reflex response in the gastrocnemius muscle following backward perturbation. Flupentixol, however, which in addition blocks D1 receptors, had no effect on compensatory gastrocnemius EMG responses. Furthermore, neither the peripherally acting dopamine D2 receptor antagonist domperidon nor the sedative diazepam had any significant influence on this functionally essential reflex mechanism. None of the drugs tested had a significant effect on the tibialis anterior responses elicited following forward perturbation. It is concluded that the reduced stretch sensitivity of the gastrocnemius (but not that of the tibialis anterior) during perturbations of stance described for parkinsonian patients corresponds to these results and arises from an impaired function of central dopamine D2 receptors.

Adult↗
PubMed1990

Interlimb coordination of stance in children: divergent modulation of spinal reflex responses and cerebral evoked potentials in terms of age.

EMG responses in the gastrocnemius (GM) and tibialis anterior muscles (TA) of both legs together with cerebral evoked potentials (CP), were recorded following perturbations of stance on a treadmill with split belts, in two age groups of children. Unilateral displacements were followed by ipsilateral short latency and bilateral long latency EMG responses. The CP was similar in both tasks. When displacements were simultaneously induced in opposite directions, a significant reduction in the long latency components of EMG responses occurred, while the amplitude of the CP was maximal in this condition. In the older children the CP and long latency EMG responses were larger and the short latency reflex potentials smaller in all conditions compared to the younger children. It is concluded that (1) CP and EMG responses reflect a divergent modulation of a given somatosensory input; (2) developmental changes are reflected in alterations in the amplitude of CP and EMG responses; (3) there is no evidence of transcortically mediated muscle responses.

Aging↗
PubMed1990

[Comparison of guar gum, wheat bran and placebo on carbohydrate and lipid metabolism in type II diabetics].

10 non-insulin-dependent (NIDDM) diabetic patients of the University Hospital Basle completed a placebo-controlled open crossover study of three 3-month periods in which the response to 30 g wheat bran and 15 g guar gum daily, respectively, was compared with placebo response. No significant difference occurred in blood glucose or HbA1c. Only postprandial plasma insulin levels were significantly lower in the afternoon at the end of both treatments (p less than 0.05). Serum total cholesterol levels decreased under guar gum by 10% (p less than 0.01), as did LDL cholesterol and the ratio of total to HDL cholesterol (p less than 0.05). Triglycerides were significantly lower (p less than 0.05) after 8 weeks. We conclude that neither guar gum nor wheat bran improves the metabolic control of NIDDM, but guar gum may be useful in patients with high serum total cholesterol levels.

Adult↗
PubMed1990

[Evaluation of Pen meters for blood glucose analysis in ambulatory diabetics].

A recently developed pen-sized glucose meter using direct electrochemistry to give an automatic digital readout of the blood glucose concentration was evaluated in 10 diabetic outpatients using it at home for 8 weeks. The pen-meter readings were compared with whole blood glucose results obtained in the laboratory on an ACP-glucose analyzer. Regression statistics with slope and intercept, respectively, were 0.96% and 0.39 mmol/l (correlation coefficient r = 0.95). During the first two weeks, 53% of the patient-performed pen-meter readings differed by more than 10% from the laboratory values, during week 7 and 8 only 34%. Patients' replies to a questionnaire revealed that all welcomed the pen-meter as a fast, easy to use and highly portable device for self monitoring of blood glucose.

Blood Glucose Self-Monitoring↗
PubMed1990

Cloning of the breakpoints of a deletion associated with choroidermia.

In order to characterize a previously described submicroscopic deletion encompassing (part of) the choroideremia (tapetochoroidal dystrophy: TCD) gene, we have cloned a 10.5-kb EcoRI fragment from the patient's DNA; this fragment carries the junction between both deletion endpoints ("junction fragment"). The distal portion of this fragment defines a new marker within, or just distal to, the TCD gene. This marker has been employed to confirm the diagnosis in several affected family members, and to rule out carriership in a female at risk with conspicuous clinical signs.

Blotting, Southern↗
PubMed1990

Patterns of contact phase proteins indicating neuropathy in diabetic patients.

In 42 outpatients of the diabetology division, coagulation and fibrinolysis variables were determined in order to detect typical patterns of results with which it was possible to discriminate between three groups with different diabetic complications (17: no complication, 7: angiopathy alone, 18: neuropathy with or without other complications). There was a statistically significant discriminatory function involving C1-inhibitor concentration, high molecular weight kininogen coagulant activity and fibrinogen as the most decisive variables. The neuropathy group was appropriately separated from the others with an 81% correct reclassification. Heparin cofactor II, histidine-rich glycoprotein, alpha 2-macroglobulin, pre-kallikrein and factor XII had no discriminative power.

Adult↗