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Biomedical subjects

W Paulus

Publications and source records attributed to W Paulus.

At least 19 recordsLinked to original sources
PubMed2007

Chromosomal imbalances and NF2 mutational analysis in a series of 10 spinal nerve sheath myxomas.

AIMS: To report the demographic, clinical and molecular profile of a series of intraspinal nerve sheath myxomas. Nerve sheath myxomas are diagnostically challenging, mainly cutaneous spindle cell neoplasms exhibiting Schwann cell differentiation. They are frequently mistaken for neurothekeomas and their genetic features are essentially unknown. METHODS AND RESULTS: Ten spinal nerve sheath myxomas with a preferential location in the lumbar spine (70%) were investigated. Presenting symptoms consisted of sciatic pain (100%), muscle weakness and paraesthesia (60% each). Intraoperatively, all tumours were attached to a spinal nerve. Chromosomal imbalances by comparative genomic hybridization were found in 8/10 cases, consisting of -22q (80%) and -19 (30%). Polymerase chain reaction analysis of the NF2 gene (exons 1-16) revealed two tumours with mutations in exon 8 and 14, respectively. CONCLUSIONS: Although these 10 nerve sheath myxomas exhibited Schwann cell differentiation and frequently showed loss of chromosome 22q typically encountered in peripheral nerve tumours, only two cases demonstrated mutations of the NF2 gene. This may indicate involvement of other tumour suppressor genes on 22q in nerve sheath myxomas and shows that they are more closely related at the molecular level to sporadic schwannomas, underscoring the presumption that they are true nerve sheath tumours.

Adult↗
PubMed2006

Growth hormone response in low-dose apomorphine test correlates with nigrostriatal dopamine transporter binding in patients with Parkinson's disease.

Challenge with low-dose apomorphine causes a rise in growth hormone (GH) in patients with Parkinson's disease (PD). We studied 18 patients with early PD, who showed an increase of GH in the low-dose apomorphine test, by means of [(123)I] FP-CIT-SPECT. The mean specific dopamine transporter binding of the 18 patients was 1.50 +/- 0.56 in the striatum, 1.20 +/- 0.59 in the putamen, and 1.76 +/- 0.59 in the caudate nucleus. The increase of GH (1.05 +/- 1.01 ng/ml at baseline to 9.46 +/- 6.36 ng/ml 45 min after apomorphine injection; p < 0.001) was significant. There was a significant negative correlation of the increase of GH with the mean specific dopamine transporter binding in all three regions (r between -0.490 and -0.587; p between 0.04 and 0.01). Challenge with low-dose apomorphine may therefore be used as an indirect tool to measure the extent of nigrostriatal neurodegeneration in early PD.

Adult↗
PubMed2006

[Plasma exchange therapy for steroid-unresponsive multiple sclerosis relapses: clinical experience with 16 patients].

Patients with severe multiple sclerosis (MS) relapses which do not respond sufficiently to corticosteroids can undergo escalating immunotherapy with plasma exchange. We review the course of 14 apheresis cycles in 13 adult patients and three pediatric cases from our center between 2004 and 2005. Nine cases were due to optic neuritis, five had experienced clinically isolated syndromes, and two suffered from Devic's disease. Of the adult patients, 71% had good or very good outcome. The mean time point of improvement was after the third plasmapheresis session, and early initiation of plasma exchange therapy (within 1 month after begin of relapse) was associated with better outcome. In pediatric MS, two of three patients showed clear improvement. These data argue for a very good therapeutic effect of plasma exchange if performed early and with adequate indication.

Activities of Daily Living↗
PubMed2006

[Neurophysiological and neuroimaging studies for restless legs syndrome and periodic leg movement disorder].

The restless legs syndrome (RLS) is a clinical diagnosis based on the four essential criteria defined by the International Restless Legs Syndrome Study Group (IRLSSG). An idiopathic form can be separated from a symptomatic form. Neurophysiological studies have investigated the pathophysiology of the idiopathic RLS or have been used to exclude a symptomatic cause, in particular polyneuropathy. So far cortical excitability changes, corticomotor, somatosensory and auditory pathways, spinal cord excitability, B-wave rhythm and cycling alternating pattern, as well as reflex mechanisms have been investigated by electroencephalography, evoked potentials, Bereitschaftspotentials, nerve conduction and thermal threshold measurements, electromyography, transcranial Doppler sonography, measurements of the spinal flexor reflex as well as neuroimaging techniques. The etiology of the RLS cannot be revealed by these methods, neurophysiological studies in RLS are, however, useful for a better understanding of the pathophysiology and for exclusion of a polyneuropathy or other symptomatic causes. In addition to neurophysiological investigations, small fiber neuropathy, which seems to be a more common finding in RLS patients than expected to date, may need biopsy for confirmation. This review will focus on investigations of the different systems involved with diverse neurophysiological methods.

Brain↗
PubMed2006

Knockdown of annexin 2 decreases migration of human glioma cells in vitro.

Diffuse invasion of brain tissue is a major reason for the poor prognosis of patients with glioblastoma. Annexin 2, a member of the large annexin family of Ca2+ and membrane-binding proteins, is expressed at high protein levels in human gliomas and has been proposed as a marker of glioma malignancy, while its functional role in these tumours is unknown so far. The ability of annexin 2 to interact with the actin cytoskeleton, as well as its potential to bind invasion-associated proteases, suggests that it could participate in invasion-associated processes in human gliomas. Therefore, we analysed here functional consequences of RNA interference-mediated silencing of annexin 2 in U87MG and U373MG human glioma cell lines. While no impact of annexin 2 downregulation on proliferation and adhesion was observed, our analyses revealed that migration of U87MG and U373MG cells was significantly inhibited following annexin 2 depletion. This effect was not related to a compensatory increase of the related annexins 1 or 6. Our findings identify annexin 2 as a potential candidate involved in glioma invasion and support the potential of RNA interference as powerful tool in the decryption of glioma invasion mechanisms.

Annexin A2↗
PubMed2006

Immunohistochemical profile and chromosomal imbalances in papillary tumours of the pineal region.

The histopathology of papillary tumours of the pineal region (PTPR) closely resembles that of ependymomas and choroid plexus tumours. Therefore, immunohistochemical staining profiles were investigated in a series of 15 PTPR. In addition to cytokeratin, synaptophysin and glial fibrillary acidic protein expression, PTPR were examined for the presence of dot- or ring-like epithelial membrane antigen (EMA) immunoreactivity typically encountered in ependymoma, staining for inwardly rectifying potassium channel Kir7.1 and stanniocalcin-1 (specifically expressed in choroid plexus tumours) as well as microtubule-associated protein-2 (MAP-2). Furthermore, comparative genomic hybridization was performed in five PTPR. Cytokeratin was expressed in all PTPR examined, whereas glial fibrillary acidic protein and synaptophysin staining were absent. Dot- or ring-like EMA immunoreactivity was only observed in 1 out of 15 PTPR. Membranous Kir7.1 and cytoplasmic stanniocalcin-1 staining were present in the minority of PTPR (3/15 and 4/15, respectively). In contrast, MAP-2 immunoreactivity was encountered in 13 out of 15 PTPR, but was significantly less frequently observed in a series of choroid plexus tumours (7/37). PTPR mainly presented with chromosomal losses affecting chromosomes 10 (4/5 cases) and 22q (3/5 cases) as well as gains on chromosomes 4 (4/5 cases), 8 (3/5 cases), 9 (3/5 cases) and 12 (3/5 cases). To conclude, the majority of PTPR can be distinguished from ependymomas and choroid plexus tumours by absent staining for epithelial membrane antigen, Kir7.1 and staniocalcin-1 as well as the presence of distinct MAP-2 immunoreactivity. Antibodies directed against these antigens are thus expected to be valuable markers in the diagnosis of papillary tumours located in the vicinity of the third ventricle.

Adenocarcinoma, Papillary↗
PubMed2006

A case of cerebral Whipple's disease initially presenting with isolated focal myoclonus.

Neurological manifestations in Whipple's disease are highly variable and tend to occur at later stages of the disease. However, isolated, focal neurological symptoms are reported to be rare. Here we describe the successful treatment of a case of cerebral Whipple's disease initially presenting solely with isolated myoclonic jerks of the left hand and forearm evolving to a segmental myoclonus at a later stage. Additionally, we present - to our knowledge - a novel treatment by administration of immunomodulatory therapy (IVIg) in addition to established antibiotics.

Adult↗
PubMed2006

Higher variability of phosphene thresholds in migraineurs than in controls: a consecutive transcranial magnetic stimulation study.

The aim of this study was to characterize the temporal course of phosphene thresholds (PT) using transcranial magnetic stimulation (TMS) in control subjects and in subjects with migraine and to observe whether changes in PT over time can predict a subsequent migraine attack. PTs were measured in 16 migraineurs [nine with aura (MA) and seven without aura (MoA)] and nine controls five times over an approximately 10-week period. Mean PTs were not significantly different between migraineurs and controls; however, there was a trend in MA showing lower thresholds. The minimum threshold values were also smaller in MA subjects than in MoA or control subjects. Generally, PTs had higher variance in migraineurs than in controls, revealing a significant increase in standard deviation of PTs in MA subjects. There was no significant difference of thresholds from the first to the last stimulation in controls and in MoA subjects, but the 3rd, 4th and 5th measurements of MA subjects were significantly lower than their first measurements. Four migraineurs experienced headache within 1 day after one of the measurements. They had either very low or very high PTs compared with the PT values which were not followed by a migraine attack. Our results imply that migraineurs show a higher variability among PT measurements over time than controls, revealing unstable excitability levels in these patients. Additionally, both particularly high and low PTs might predict a subsequent headache in some individuals.

Adolescent↗
PubMed2005

[Medications in pregnancy].

Exaggerated caution or even deferment in the treatment of chronically ill mothers-to-be, for example, in the case of epilepsy, hypertension or bronchial asthma, may result in a dramatic worsening of the underlying disease and thus may threaten the further development of the fetus. On the other hand, an inadequate knowledge of the true risks of pharmacological treatment already applied in the early stages of pregnancy, leads to numerous abortions that are inappropriately indicated. As a basic rule, when planning pharmacological treatment in a pregnant woman, well tried and tested substances should be given preference over new drugs. If a pregnant woman has been exposed to an insufficiently tested substance as a result of ignorance of her pregnancy, recognized centers with appropriate data banks (www.reprotox.de) should be consulted.

Abnormalities, Drug-Induced↗
PubMed2005

Cellular and reticular variants of haemangioblastoma revisited: a clinicopathologic study of 88 cases.

The presence of histological variants of haemangioblastoma is well established, but data on the prognostic implications of histological subtyping are missing. We thus characterized clinical factors associated with histological subtypes, that is, of the cellular and reticular variant of haemangioblastoma, in a series of 88 consecutive primary haemangioblastomas of the central nervous system. Ten haemangioblastomas were classified as 'cellular' according to Cushing and Bailey. As compared to the more common 'reticular' variant (n = 78), the proportion of tumours containing glial fibrillary acidic protein-positive tumour cells (80% vs. 7%), as well as median Ki67 (MIB1) proliferation indices [4% (quartiles: 1-8%) vs. < 1% (<1-2%)], was significantly higher in cellular haemangioblastomas (P < 0.01). Recurrences were more frequent in the cellular variant [2/8 (25%) vs. 4/51 (8%)]. Kaplan-Meier analysis confirmed a significantly higher probability of recurrence in the cellular variant (Log-Rank test P < 0.01). Cox regression analysis not only confirmed the well established association of von Hippel-Lindau disease with tumour recurrence (P < 0.01), but also revealed an independent effect of histological subtype on the probability of recurrence (P < 0.05), whereas no significant influence of age, sex or tumour location was observed. To conclude, the results from this retrospective study suggest that histological subtyping of haemangioblastomas has prognostic implications and might contribute to identify patients at risk for recurrence.

Adolescent↗
PubMed2005

Altered motion perception in migraineurs: evidence for interictal cortical hyperexcitability.

Much research on visual functions in migraine has pinpointed the existence of abnormal visual processing between attacks. However, it is not clear if this is due to cortical hyper- or hypoexcitability. We aimed to clarify this issue by comparing motion perception thresholds of subjects with migraine with (MA) or without aura (MoA) and control subjects. Two types of dot kinetograms were used: in the first experiment coherently moving dots were presented in an incoherent environment, while in the second only coherent motion was seen. Subjects with migraine displayed significantly impaired motion perception compared with controls when they had to detect the direction of the coherently moving dots in an incoherent environment, while they were slightly better in a direction discrimination task, where only coherent motion was presented. This pattern of results is comparable to those achieved by an external excitability enhancement of V5 induced in healthy human subjects in a former study of our group. According to this, a cortical excitability enhancement can result in an impaired focusing on a given signal against a noisy background, but improves perception of non-ambiguous stimuli. Thus we conclude that migraineurs display enhanced visual cortical excitability between attacks in V5.

Adult↗
PubMed2004

Serum S100beta increases in marathon runners reflect extracranial release rather than glial damage.

The contribution of extracranial tissue damage to serum S100beta increases was examined in 18 marathon runners without clinical or laboratory signs of brain damage. Postrace serum S100beta and creatine kinase (CK) concentrations increased (p < 0.001), and areas under the curve were highly correlated (p = 0.001). To conclude, serum S100beta increases after running originate from extracranial sources. CK determination may improve specificity of S100beta as a marker of brain tissue damage in acute trauma.

Adult↗
PubMed2004

[Drug therapy in pregnancy--a practical guide].

Pharmacotherapy in pregnancy is often problematic, since both the mother-to-be and her doctor are often concerned about possible risks for the unborn child. On the other hand, we now have sufficient knowledge of a whole range of medications, to enable the recommendation of safe drug treatment in almost any clinical situation. The family doctor, too, is often consulted by pregnant women requiring treatment for internistic problems. These include such pregnancy-unrelated problems as essential hypertension or bronchial asthma, as well as pregnancy-related disorders such as urinary tract infection or gastrointestinal problems.

Acetaminophen↗
PubMed2004

Effects of transcranial direct current stimulation over the human motor cortex on corticospinal and transcallosal excitability.

Weak transcranial direct current stimulation (tDCS) can induce long lasting changes in cortical excitability. In the present study we asked whether tDCS applied to the left primary motor cortex (M1) also produces aftereffects distant from the site of the stimulating electrodes. We therefore tested corticospinal excitability in the left and the right M1 and transcallosal excitability between the two cortices using transcranial magnetic stimulation (TMS) before and after applying tDCS. Eight healthy subjects received 10 min of anodal or cathodal tDCS (1 mA) to the left M1. We examined the amplitude of contralateral motor evoked potentials (MEPs) and the onset latency and duration of transcallosal inhibition with single pulse TMS. MEPs evoked from the tDCS stimulated (left) M1 were increased by 32% after anodal and decreased by 27% after cathodal tDCS, while transcallosal inhibition evoked from the left M1 remained unchanged. The effect on MEPs evoked from the left M1 lasted longer for cathodal than for anodal tDCS. MEPs evoked from the right M1 were unchanged whilst the duration of transcallosal inhibition evoked from the right M1 was shortened after cathodal tDCS and prolonged after anodal tDCS. The duration of transcallosal inhibition returned to control values before the effect on the MEPs from the left M1 had recovered. These findings are compatible with the idea that tDCS-induced aftereffects in the cortical motor system are limited to the stimulated hemisphere, and that tDCS not only affects corticospinal circuits involved in producing MEPs but also inhibitory interneurons mediating transcallosal inhibition from the contralateral hemisphere.

Adult↗