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Biomedical subjects

J Winkelmann

Publications and source records attributed to J Winkelmann.

At least 19 recordsLinked to original sources
PubMed2006

Multiexponential decay autocorrelation function in dynamic light scattering in near-critical ternary liquid mixture.

The dynamic structure factor of a ternary liquid mixture is calculated from the theory of thermodynamic fluctuations with the help of linearized hydrodynamic equations. The theoretical model allows evaluating and classifying the transport properties near a critical solution point of a ternary mixture. In the vicinity of the critical solution point, experimental dynamic light scattering measurements reveal two hydrodynamic relaxation modes with well-separated characteristic relaxation times. From the autocorrelation functions, we can determine two effective diffusivities D(1) and D(2). As theoretically predicted by a model developed in this work, one of these two modes can be associated with thermal diffusion and the other with mass diffusion. In the special case of an incompressible liquid mixture limit, D(1) and D(2) are decoupled, becoming thermodiffusion coefficient D(T) and mutual mass diffusion coefficient D(ij). A possible physical meaning of D(1) and D(2) for a ternary mixture is discussed.

Journal Article↗
PubMed2006

RLS3: fine-mapping of an autosomal dominant locus in a family with intrafamilial heterogeneity.

A new locus for restless legs syndrome (RLS3) was identified on chromosome 9p24-22. The authors analyzed transmission disequilibrium tests (TDTs) and affecteds-only linkage analysis in one large family of Bavarian origin, taking into account age at onset. P values were 0.0054 for marker D9S1810 for TDT and 0.0009 for the affecteds-only linkage analysis, providing a confirmation of RLS3. This study narrows the region containing the autosomal dominant RLS3 locus to 11.1 cM (16.6 Mbp).

Chromosome Disorders↗
PubMed2005

"Anxietas tibiarum". Depression and anxiety disorders in patients with restless legs syndrome.

BACKGROUND: Symptoms of anxiety and depression in patients with restless legs syndrome (RLS) have been observed. However, it is unclear whether rates of threshold depression and anxiety disorders according to DSM-IV criteria in such patients are also elevated. METHODS: 238 RLS patients were assessed with a standardized diagnostic interview (Munich-Composite International Diagnostic Interview for DSM-IV) validated for subjects aged 18-65 years. Rates of anxiety and depressive disorders were compared between 130 RLS patients within this age range and 2265 community respondents from a nationally representative sample with somatic morbidity of other types. RESULTS: RLS patients revealed an increased risk of having 12-month anxiety and depressive disorders with particularly strong associations with panic disorder (OR=4.7; 95% CI=2.1-10.1), generalized anxiety disorder (OR=3.5; 95% CI= 1.7-7.1), and major depression (OR=2.6; 95% CI=1.5-4.4). In addition, lifetime rates of panic disorder and most depressive disorders as well as comorbid depression and anxiety disorders were considerably increased among RLS patients compared with controls. CONCLUSIONS: The results suggest that RLS patients are at increased risk of having specific anxiety and depressive disorders. Causal attributions of patients suggest that a considerable proportion of the excess morbidity for depression and panic disorder might be due to RLS symptomatology.

Adolescent↗
PubMed2002

Retention of dopamine 2 receptor mRNA and absence of the protein in craniospinal and extracranial metastasis of a malignant prolactinoma: a case report.

OBJECTIVES: The case presented here describes the clinical evolution of a malignant prolactinoma with occurrence of intra- and extra-cranial metastases. In this case, the presence of dopamine 2 receptor (D2R) was studied at the mRNA and protein level, in order to understand the pathological background of the resistance to treatment with different dopamine agonists. DESIGN: Together with an extensive description of the clinical history of this case, a combination of in vitro and in vivo techniques was performed to provide the basis of the dopamine resistance developed in the course of the disease. METHOD: A comparison of the D2R was performed in specimens obtained at presentation of the disease compared with autoptic specimens derived from local invasion and metastasis using in situ hybridization and immunohistochemical techniques. RESULTS: Intact D2R mRNA was found in the primitive tumor and metastatic tissues, whereas protein for the same receptor was present only in the tissues derived from neurosurgical operations and not in the metastases obtained post-mortem. CONCLUSION: This is the first report of the absence of D2R protein despite the retention of the transcript in an advanced stage of a malignant prolactinoma. The findings of this single case suggest the hypothesis that postranscriptional mechanisms may contribute to the development of dopamine resistance in prolactinomas.

Brain Neoplasms↗
PubMed2001

Long-term effects of pergolide in the treatment of restless legs syndrome.

An open follow-up of a controlled study in patients with restless legs syndrome (RLS) shows that the beneficial effect of pergolide on RLS symptoms persists throughout at least 1 year. Twenty-two patients of 28 (78.6%) continued to take pergolide. Polysomnographic measurements showed a persistent improvement of PLM index, PLMS arousal index, total sleep time, and sleep efficiency (p = 0.0001). Side effects, in particular nausea, were common but were well controlled by domperidone in most patients.

Adult↗
PubMed2001

Increased growth hormone response to apomorphine in Parkinson disease compared with multiple system atrophy.

BACKGROUND: Parkinson disease (PD) is often difficult to distinguish from parkinsonian syndromes of other causes in early stages of the disease. In search of a suitable endocrinologic challenge test, we investigated dopaminergic sensitivity in patients with de novo parkinsonian syndromes. OBJECTIVE: We measured the growth hormone (GH) response to a subthreshold dose of the dopamine 1-dopamine 2 receptor agonist apomorphine hydrochloride to differentiate parkinsonian syndromes from PD. PATIENTS AND METHODS: Seventeen patients with a clinical diagnosis of PD, 16 patients with a clinical diagnosis of multiple system atrophy, and 11 healthy controls. The GH response to a subthreshold dosage of apomorphine and to somatorelin (GH-releasing factor) was tested in a randomized order; on the third day the protocol was repeated with a clinically effective dose of apomorphine. RESULTS: The GH response to the low dose of apomorphine was significantly increased in patients with PD when compared with patients with multiple system atrophy or the control subjects (multivariate analyses of covariance; univariate F test, all P<.05). In contrast, there were no significant group differences with use of the higher dose of apomorphine or in the somatorelin-induced GH release. CONCLUSIONS: The GH response to a subthreshold dose of apomorphine appears to be a useful tool to identify patients with PD vs multiple system atrophy. The enhanced GH response to a subthreshold dopaminergic stimulus may reflect a hypersensitivity of the extrastriatal dopamine receptors in PD.

Adrenocorticotropic Hormone↗
PubMed2001

Long-term follow-up on restless legs syndrome patients treated with opioids.

The medical records of 493 patients with restless legs syndrome (RLS) from three major centers were studied to determine the number and outcome of patients who had been treated with opioids as a monotherapy. At one time or another 113 patients (51 men, 62 women; age range, 37-88 years) had been on opioid therapy either alone (36 patients) or with opioids added secondarily to other medications used to treat RLS (77 patients). Twenty-three of the 36 opioid monotherapy patients had failed dopaminergic and other therapeutic agents prior to the initiation of opioid monotherapy. Twenty of the 36 opioid monotherapy patients continue on monotherapy for an average of 5 years 11 months (range, 1-23 years), despite their knowledge of the availability of other therapies. Of the 16 patients who discontinued opioids as a sole therapy, the medication was discontinued in only one case because of problems related to addiction and tolerance. Polysomnography on seven patients performed after an average of 7 years 1 month of opioid monotherapy (range, 1-15 years) showed a tendency toward an improvement in all leg parameters and associated arousals (decrease in PLMS index, PLMS arousal index, and PLM while awake index) as well as all sleep parameters (increase in stages 3 and 4 and REM sleep, total sleep time, sleep efficiency, and decrease in sleep latency). Two of these seven patients developed sleep apnea and a third patient had worsening of preexisting apnea. Opioids seem to have long-term effectiveness in the treatment of RLS and PLMS, but patients on long-term opioid therapy should be clinically or polysomnographically monitored periodically for the development of sleep apnea.

Aged↗
PubMed2001

[Pathophysiology of restless-legs syndrome. Review of current research].

The primary pathomechanism of restless legs syndrome is unclear. Neurophysiological, pharmacological, and imaging studies have demonstrated a complex interaction between central and peripheral structures. The degree of integration of central and peripheral mechanisms is not known. Altered excitability at a spinal level modulated by supraspinal rhythms of the brainstem possibly plays an important role. There is no anatomical structural lesion and it is more likely that circadian disturbances of dopaminergic and/or opioidergic neurotransmission are involved.

Adult↗
PubMed2001

Opioid and dopamine antagonist drug challenges in untreated restless legs syndrome patients.

Background: The restless legs syndrome (RLS) is a common sensomotor disorder associated with severe sleep disturbances. Symptoms clearly improve following treatment with dopaminergic or opioidergic agonists.Objective: To further elucidate the involvement of opioidergic and dopaminergic mechanisms in the pathophysiology of RLS, the effects of specific antagonists on motor (periodic leg movements) and subjective (sensory) RLS-symptoms during daytime were assessed.Methods: A modified suggested immobilization test was performed in eight drug-naive RLS-patients. An infusion of either naloxone, metoclopramide or placebo was administered. In addition, the hormonal levels of adrenocorticotropic hormone, cortisol, prolactin and growth hormone were determined, to elucidate a possible involvement of the hypothalamic-pituitary-adrenocortical (HPA) system in RLS.Results: RLS sensory or motor symptoms could not be provoked. Hormonal responses showed no abnormal profiles.Conclusions: Rather than a general alteration of the opioidergic/dopaminergic tone and an involvement of the HPA system, it is more likely that specific neuronal dopaminergic or opioidergic pathways are altered in the pathophysiology of RLS.

Journal Article↗
PubMed2001

Mutations in the gene encoding epsilon-sarcoglycan cause myoclonus-dystonia syndrome.

The dystonias are a common clinically and genetically heterogeneous group of movement disorders. More than ten loci for inherited forms of dystonia have been mapped, but only three mutated genes have been identified so far. These are DYT1, encoding torsin A and mutant in the early-onset generalized form, GCH1 (formerly known as DYT5), encoding GTP-cyclohydrolase I and mutant in dominant dopa-responsive dystonia, and TH, encoding tyrosine hydroxylase and mutant in the recessive form of the disease. Myoclonus-dystonia syndrome (MDS; DYT11) is an autosomal dominant disorder characterized by bilateral, alcohol-sensitive myoclonic jerks involving mainly the arms and axial muscles. Dystonia, usually torticollis and/or writer's cramp, occurs in most but not all affected patients and may occasionally be the only symptom of the disease. In addition, patients often show prominent psychiatric abnormalities, including panic attacks and obsessive-compulsive behavior. In most MDS families, the disease is linked to a locus on chromosome 7q21 (refs. 11-13). Using a positional cloning approach, we have identified five different heterozygous loss-of-function mutations in the gene for epsilon-sarcoglycan (SGCE), which we mapped to a refined critical region of about 3.2 Mb. SGCE is expressed in all brain regions examined. Pedigree analysis shows a marked difference in penetrance depending on the parental origin of the disease allele. This is indicative of a maternal imprinting mechanism, which has been demonstrated in the mouse epsilon-sarcoglycan gene.

Adolescent↗
PubMed2000

Clinical characteristics and frequency of the hereditary restless legs syndrome in a population of 300 patients.

There is a genetic contribution to the idiopathic restless legs syndrome (iRLS). An autosomal dominant mode of inheritance is suspected, but as yet no gene has been identified. To assess the frequency and characteristics of the hereditary restless legs syndrome (RLS) in comparison to those of non-hereditary RLS, we analysed the clinical data of 300 RLS patients. All 300 patients diagnosed as RLS according to the criteria of the International RLS Study Group were examined using a standard questionnaire covering demographic data, family history, clinical symptoms, subjective sleep disturbances and course of the disease. In all patients a complete neurological examination was performed, and in selected cases electrophysiological examinations and polysomnographic studies. Family history was rated as definitely positive when at least one first-degree relative was examined and classified as RLS according to the criteria by one of the authors. If it proved impossible to contact family members to verify reports of a family history, the patients were classified as only having a "possible positive family history." 232 of the 300 patients had iRLS and 68 secondary RLS due to uremia (uRLS). 42.3% of the patients with iRLS and 11.7% of those with uRLS were classified as having "definite positive" hereditary RLS, with a further 12.6% of iRLS patients and 5.8% of uRLS patients as having "possible positive" hereditary RLS. Patients with definite hereditary RLS were significantly younger at the age of onset than those with a negative family history (35.45 vs. 47.17 years, p < 0.05). The clinical characteristics of the disease were similar in both groups, except that women with hereditary RLS experienced a worsening of symptoms during pregnancy (19.1% vs. 2.6%, p < 0.05). Our study shows that patients with hereditary RLS may experience an earlier onset of the disease. Hereditary and non-hereditary RLS present with similiar clinical signs and symptoms.

Adaptation, Psychological↗
PubMed1999

A randomized controlled study of pergolide in patients with restless legs syndrome.

BACKGROUND: Open clinical trials indicate that low doses of pergolide, a long-acting D1 and D2 dopamine agonist, lead to a reduction in the symptoms of restless legs syndrome (RLS) with subjective improvement in sleep quality. OBJECTIVE: To assess the therapeutic efficacy of pergolide in improving sleep and subjective measures of well-being in patients with idiopathic RLS using polysomnography and clinical ratings. METHODS: In a randomized, double-blind, placebo-controlled crossover design we enrolled 30 patients with idiopathic RLS according to the criteria of the International RLS Study Group. All patients were free of psychoactive drugs for at least 2 weeks before the study. Patients were monitored using polysomnography, clinical ratings, and sleep diaries at baseline and at the end of a 4-week pergolide or placebo treatment period. The initial dosage of 0.05 mg pergolide was increased to the best subjective improvement paralleled by 20 mg domperidone tid. RESULTS: At a mean dosage of 0.51 mg pergolide as a single daily dose 2 hours before bedtime, there were fewer periodic leg movements per hour of time in bed (5.7 versus 54.9, p < 0.0001), and total sleep time was significantly longer (373 versus 261 minutes, p < 0.0001). Ratings of subjective sleep quality, quality of life, and severity of RLS were improved significantly without relevant adverse events. CONCLUSION: Pergolide given as a single low-to-medium bedtime dose in combination with domperidone provides a well-tolerated and effective treatment of sensorimotor symptoms and sleep disturbances in patients with primary RLS.

Adult↗
PubMed1999

A controlled study of additional sr-L-dopa in L-dopa-responsive restless legs syndrome with late-night symptoms.

OBJECTIVE: To investigate whether a combination treatment of regular-release levodopa (rr-L-dopa) and sustained-release levodopa (sr-L-dopa) compared with monotherapy of rr-L-dopa improves sleep quality and reduces periodic limb movements (PLM) in patients with restless legs syndrome (RLS) and problems with maintaining sleep. BACKGROUND: Reappearance of RLS symptoms during the second half of the night while being treated with rr-L-dopa is a common problem in the treatment of sleep disturbances caused by RLS. METHODS: A randomized, controlled, double-blind crossover trial was undertaken. Eligible patients fulfilled the diagnostic criteria of the International RLS Study Group, and met an actigraphically confirmed higher number of PLM per hour time in bed (PLM index) during the second half compared with the first half of the night under treatment with rr-L-dopa. During the crossover periods the patients received 100 to 200 mg rr-L-dopa plus either placebo or 100 to 200 mg sr-L-dopa at bedtime for 4 weeks each period. RESULTS: Thirty patients with RLS (11 men and 19 women) were assessed by actigraphy and subjective sleep quality, and showed a significant improvement in PLM index (p < 0.0001), in "time in bed without movements" (p < 0.0001), and in subjective sleep quality (p < 0.001). Eight of 30 patients reported an altered pattern of RLS symptoms, characterized by a time shift of RLS symptoms into the afternoon or evening, five of these during monotherapy with rr-L-dopa. CONCLUSIONS: A combination therapy of rr-L-dopa and sr-L-dopa is better than monotherapy with rr-L-dopa in reducing the frequency of PLM and problems maintaining sleep, even in patients who are severely affected.

Adult↗
PubMed1999

Magnetic resonance imaging findings in corticobasal degeneration.

Two women (patient 1, 77 years old, and patient 2, 63 years old) with strong clinical evidence for corticobasal degeneration (CBD) are presented. Patient 2 was in an early stage of the disease with only a mild disability of her left hand. In addition to the clinical characteristics, both patients presented the typical cortical reflex myoclonus. Magnetic resonance imaging studies for both patients revealed nearly identical hyperintense lesions somatotopic from the left-hand primary motor cortex (M1), extending to the midline and possibly supplementary motor area (SMA) in patient 2. To our knowledge, this has not been previously described in patients with CBD. These lesions may play a role in the etiology and the development of CBD with involvement of the M1 and may correspond to the underlying pathology of demyelination or gliosis.

Aged↗