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Biomedical subjects

A Straube

Publications and source records attributed to A Straube.

At least 55 records · Page 3Linked to original sources
PubMed2001

"Atraumatic" Sprotte needle reduces the incidence of post-lumbar puncture headaches.

Post-lumbar puncture headache (PLPH) is best explained by spinal fluid leakage due to delayed closure of a dural defect. In a prospective, randomized, double-blind study, taking into consideration all known methodological problems, the authors compared the incidence of PLPH using the "atraumatic" Sprotte needle vs the "traumatic" Quincke needle. Of the 230 patients included in the final analysis, 24.4% of patients in the "traumatic" group developed PLPH, whereas only 12.2% of patients in the "atraumatic" group did (p < 0.05). Therefore, use of the "atraumatic" Sprotte needle for lumbar puncture is recommended.

Adult↗
PubMed2001

Cerebellar lesions impair rapid saccade amplitude adaptation.

This study investigated whether the cerebellum is essential for rapid saccade adaptation. Saccade adaptation was elicited by 30% backward target steps during the primary saccade. Patients with cerebellar lesions adapted less than normal subjects, but saccade adaptation was most impaired in the group of patients with cerebellar degeneration. As the variability of the saccade gain in patients with cerebellar degeneration did not significantly differ from that in the other patients, the increased variability in motor performance due to a cerebellar lesion cannot alone explain this impaired adaptation.

Adult↗
PubMed2001

A split motor domain in a cytoplasmic dynein.

The heavy chain of dynein forms a globular motor domain that tightly couples the ATP-cleavage region and the microtubule-binding site to transform chemical energy into motion along the cytoskeleton. Here we show that, in the fungus Ustilago maydis, two genes, dyn1 and dyn2, encode the dynein heavy chain. The putative ATPase region is provided by dyn1, while dyn2 includes the predicted microtubule-binding site. Both genes are located on different chromosomes, are transcribed into independent mRNAs and are translated into separate polypeptides. Both Dyn1 and Dyn2 co-immunoprecipitated and co-localized within growing cells, and Dyn1-Dyn2 fusion proteins partially rescued mutant phenotypes, suggesting that both polypeptides interact to form a complex. In cell extracts the Dyn1-Dyn2 complex dissociated, and microtubule affinity purification indicated that Dyn1 or associated polypeptides bind microtubules independently of Dyn2. Both Dyn1 and Dyn2 were essential for cell survival, and conditional mutants revealed a common role in nuclear migration, cell morphogenesis and microtubule organization, indicating that the Dyn1-Dyn2 complex serves multiple cellular functions.

Amino Acid Sequence↗
PubMed2001

Dilated cervical epidural veins and extra arachnoid fluid collection in orthostatic headaches.

Cervical MRI of eight patients with severe orthostatic headache showed a convex-shaped, prominent, dilated anterior, internal vertebral venous plexus with a flow-void signal in all patients and in seven also extra arachnoid fluid collection. Follow-up MRI showed resolution of the abnormalities in all patients. The authors hypothesize that these findings reflect disturbed compensatory vascular mechanisms by which autoregulation of the CSF pressure tries to compensate for the reduced CSF volume.

Adult↗
PubMed2001

TNF-alpha expression in painful and nonpainful neuropathies.

OBJECTIVE: To determine whether the cytokine tumor necrosis factor alpha (TNF-alpha) acts as a pain mediator in neuropathic pain in humans. BACKGROUND: In animal models, inflammatory cytokines such as TNF-alpha have been shown to facilitate neuropathic pain. METHODS: The expression of TNF-alpha was analyzed immunohistochemically in 20 human nerve biopsy specimens of patients with painful (n = 10) and nonpainful (n = 10) neuropathies. Additionally, serum soluble TNF-alpha receptor I (sTNF-RI) levels were determined in 24 patients with neuropathies, 16 of which were painful and 8 that were painless. RESULTS: Colocalization studies by confocal fluorescence microscopy for S-100 and TNF-alpha showed expression of TNF-alpha in human Schwann cells. Patients with painful neuropathies showed a stronger TNF-alpha immunoreactivity in myelinating Schwann cells relative to the epineurial background staining compared with patients with nonpainful neuropathy (0.949 +/- 0.047 vs 1.010 +/- 0.053, p < 0.05). Although there was no difference in sTNF-RI levels between painful (n = 16) and nonpainful (n = 8) neuropathies (sTNF-RI: 1412 +/- 545 pg/mL vs 1,318 +/- 175 pg/mL), patients with a mechanical allodynia (n = 9) had elevated serum sTNF-RI (1627 +/- 645 pg/mL vs 1233 +/- 192 pg/mL, p < 0.05) compared with patients without allodynia (n = 15). CONCLUSIONS: TNF-alpha expression of human Schwann cells may be up-regulated in painful neuropathies. The elevation of sTNF-RI in patients with centrally mediated mechanical allodynia suggests that systemic sTNF-RI levels may influence central pain processing mechanisms.

Adult↗
PubMed2001

Cerebral involvement in graft-versus-host disease after murine bone marrow transplantation.

Neurologic manifestation of graft-versus-host disease (GvHD) after allogeneic bone marrow transplantation (BMT) has until now been limited to rare neuromuscular syndromes. Investigating cerebral findings using a murine BMT model, the authors found parenchymal lymphocytic inflammation, microglia activation, and mild cerebral angiitis-like changes in allogeneic transplanted animals but not in syngeneic controls. These findings suggest that cerebral involvement during GvHD may be a new neurologic complication after BMT.

Animals↗
PubMed2001

Increased titers of antibodies against streptococcal M12 and M19 proteins in patients with Tourette's syndrome.

It has been suggested that a post-streptococcal autoimmune process may be involved in the pathogenesis of a subgroup of children with tics and obsessive-compulsive symptoms (PANDAS). Elevated antibody titers against streptococcal antigens have also been described in adult patients suffering from Tourette's syndrome (TS). In order to characterise further streptococcal antigens, we focussed on M proteins. M proteins are a major virulence factor of group A streptococci and known to evoke an immunologic cross-reaction with diverse epitopes of human tissue including brain tissue. Therefore, antibodies against M proteins may play a role in the pathophysiology of at least a subgroup of TS patients. Antibodies against M proteins were studied in 25 adult patients suffering from TS and 25 healthy controls after careful medical examination. The antibody titers against the peptides M1, M4, M6, M12 and M19 were estimated by ELISA. Our results show increased titers of antibodies against the streptococcal M12 and M19 proteins in TS patients as compared with controls, while antibody titers against M1, M4 and M6 did not differ between the TS and control groups. Elevated serum titers of antibodies against M12 and M19 proteins support the view that a streptococcus-induced autoimmune process may be involved in TS. The finding of a possible autoimmune origin of TS has implications for both pathophysiology and future therapeutic strategies.

Adolescent↗
PubMed2001

[The immune system and primary headache syndromes].

The association between pain and inflammation and certain clinical signs led physicians to suspect a connection between immunological mechanisms and headache syndromes even years ago. This review intends to give an overview of the literature which deals with immunological mechanisms in headache syndromes--with divergent results. Thus, a food allergy as a cause of migraine only seems to be relevant in a few isolated cases. Immunoglobulins or infections do not seem to play a role. Whether the complement system, auto-antibodies, immune cells or cytokines are involved in migraine pathophysiology, still remains to be determined. With regards to cluster headache, a participation of the immune system seems more probable. Although a systemic vasculitis or auto-antibodies probably do not contribute to cluster headache pathophysiology, reports of an immune activation, especially of T-cells, predominate the literature. Nevertheless, the evidence for an immunogenically triggered cluster attack is still lacking. In summary, only a mutual modulation of the immune and the pain system can be assumed with certainty.

Headache↗
PubMed2001

[Parry-Romberg syndrome and Rasmussen syndrome: only an incidental similarity?].

The Parry-Romberg syndrome is a rare and poorly understood disease characterized by slowly progressive, localized atrophy of the skin, subcutaneous tissue, muscles, and bones. The atrophy is typically localized in the face and begins in youth. In some patients, imaging can show the lesions and atrophy of the ipsilateral hemisphere of the brain. We report on a patient in whom the disease has lasted 36 years and discuss the possibility that the Parry-Romberg syndrome is related to known autoimmune disorders of the soft tissue (e.g., linear scleroderma) and Rasmussen's syndrome. There are some remarkable clinical similarities between these two syndromes, including age of onset, unilateral manifestation, and occurrence of focal seizures. It is most probable that both diseases have an autoimmunological background.

Brain↗
PubMed2001

Mislocalization of peripheral targets during fixation.

To investigate the effect of the visual stimulus configuration on localization when oculomotor performance is excluded, we evaluated the errors made when subjects compare the horizontal location of two sequentially presented peripheral targets while looking at a visual or memorized fixation spot. Eye position was monitored by means of an infrared eye tracker. Significant localization errors were observed. As long as the fixation spot stayed on or off during the entire presentation time of both peripheral targets, the localization error did not depend on the presence or absence of the fixation spot. A significant change in the localization error was observed only if the fixation spot was presented together with the first peripheral target but disappeared before the presentation of the second one. The localization error did not depend on: (1) the visual asymmetry (unilateral versus bilateral target presentation); (2) the distribution of visual attention (cued versus non-cued test location); or (3) the time interval between the two targets. These results suggest that the mislocalization observed during fixation is partially due to a mismatch between egocentric and exocentric localization mechanisms.

Analysis of Variance↗
PubMed2001

Cervical MR imaging in postural headache: MR signs and pathophysiological implications.

BACKGROUND AND PURPOSE: Postural headache most often occurs after lumbar puncture as post-lumbar puncture headache (PLPH) or, rarely, spontaneously as spontaneous intracranial hypotension headache (SIHH). In this prospective study, we used spinal MR imaging to determine the findings that would assist in the diagnosis of PLPH and SIHH and that would further our pathophysiological understanding of postural headache. METHODS: The study group consisted of 15 healthy volunteers and 20 patients with postural headache: nine with SIHH and 11 with PLPH. The craniocervical junction and the cervical spine were studied using T2-weighted fast spin-echo and T1-weighted spin-echo sequences in the axial and sagittal planes. Follow-up studies were performed in 13 patients. RESULTS: Dilatation of the anterior internal vertebral venous plexus was the most constant finding, present in 17 (85%) of 20 patients with postural headache. Spinal hygromas, whose location as subdural or epidural could not be exactly determined, were present in 14 patients (70%). A focal fluid collection was detected in the retrospinal region at the C1-C2 level in six patients with SIHH and in four patients with PLPH (50%). Tonsillar descent was detected in only one patient, and subtentorial hygroma in five patients. No abnormalities were found in the volunteers. CONCLUSION: The MR signs of dilatation of the venous plexus, presence of spinal hygromas, and presence of retrospinal fluid collections can help to establish the diagnosis of intracranial hypotension. They are probably the result of decreased CSF volume, with the retrospinal fluid collections being a transudate from the venous plexus rather than frank extravasation. Resolution of these signs parallels resolution of the headache.

Adult↗
PubMed2000

A placebo-controlled crossover trial of creatine in mitochondrial diseases.

To test the efficacy and safety of creatine (Cr) monohydrate in mitochondrial diseases, 16 patients with chronic progressive external ophthalmoplegia or mitochondrial myopathy were randomized in a crossover design to receive double-blind placebo or 20 g Cr/day for 4 weeks. Cr was well tolerated, but there were no significant effects with regard to exercise performance, eye movements, or activities of daily life. The power of this pilot study was limited and future multicenter trials are needed.

Adult↗
PubMed2000

Nicotine-induced nystagmus: three-dimensional analysis and dependence on head position.

Two- and three-dimensional analyses of nicotine-induced eye movements were performed in 53 subjects to evaluate whether they were primarily of vestibular or ocular motor origin. Nicotine-induced nystagmus was detected in 27 subjects (51%); in 25 of these (93%) it was modulated by otolith input. Three-dimensional analysis of nicotine-induced nystagmus revealed that it violates Listing's law. Taken together, these findings suggest that nicotine induces an imbalance in the vestibulo-ocular reflex.

Adult↗
PubMed2000

Indomethacin reduces CSF pressure in intracranial hypertension.

The CSF-pressure-lowering effects of indomethacin in seven patients with idiopathic intracranial hypertension and one patient with symptomatic intracranial hypertension due to a non-space-occupying meningioma are reported. CSF opening pressure between 350 and 500 mm H2O (mean 400 mm H2O) was promptly reduced by 80 to 200 mm H2O (mean reduction, 139 mm H2O) for at least 10 minutes in all patients after IV administration of 50 mg indomethacin. Four patients had mild and transient side effects (dizziness). Indomethacin might be an alternative drug for treatment of intracranial hypertension.

Adult↗