Biomedical subjects

A Schenkel

Publications and source records attributed to A Schenkel.

6 recordsLinked to original sources

PubMed1999

Botulinum toxin A in the management of spastic gait disorders in children and young adults with cerebral palsy: a randomized, double-blind study of "high-dose" versus "low-dose" treatment.

The present study was performed to assess dose-response relationships of local botulinum toxin A (BtxA) treatment in children and teenagers with spastic gait due to cerebral palsy (CP) in a randomized, double-blind study employing a "high-dose" (200 units Botox per leg) and a "low-dose" (100 units Botox per leg) treatment arm in 33 patients with CP. Response parameters included changes in muscle tone assessed by the Ashworth scale at knee joint, range-of-motion (ROM) measurements at knee and ankle joint, objective analysis of longitudinal gait parameters as well as subjective assessments of improvement. Patients in the "high-dose" arm received 40-80 units Botox/muscle versus 20-40 units Botox/muscle in the "low-dose" group. Patients in both treatment arms showed significant improvement of Ashworth score (p<0.001) and ROM (p<0.01), while gait analysis revealed significant increase in gait velocity (p<0.01) and stride-length (p<0.001) over baseline. Subjects in the "high-dose" group showed significantly greater improvement on objective response measurements compared to "low-dose" patients. Also, children aged 7 years or less had greater functional benefit compared to the subgroup of patients older than 7 years. Incidence and severity of side-effects were similar in both treatment groups. The present study demonstrated dose-dependent functional improvement of dynamic deformities and spastic gait pattern in children and young adults with CP treated with local injections of botulinum toxin. A dose of 200 units Botox per leg distributed to 4 or 5 muscle bellies per leg is superior compared to 100 units Botox per leg without significantly affecting the risk of side-effects.

Adolescent↗

PubMed1998

Wegener's granulomatosis: anti-proteinase 3 antibodies are potent inductors of human endothelial cell signaling and leakage response.

Anti-neutrophil cytoplasmic antibodies (ANCAs) targeting proteinase 3 (PR3) have a high specifity for Wegener's granulomatosis (WG), and their role in activating leukocytes is well appreciated. In this study, we investigated the influence of PR3-ANCA and murine monoclonal antibodies on human umbilical vascular endothelial cells (HUVECs). Priming of HUVECs with tumor necrosis factor alpha induced endothelial upregulation of PR3 message and surface expression of this antigen, as measured by Cyto-ELISA, with a maximum occurrence after 2 h. Primed cells responded to low concentrations of both antibodies (25 ng-2.5 microg/ml), but not to control immunoglobulins, with pronounced, dose-dependent phosphoinositide hydrolysis, as assessed by accumulation of inositol phosphates. The signaling response peaked after 20 min, in parallel with the appearance of marked prostacyclin and platelet-activating factor synthesis. The F(ab)2 fragment of ANCA was equally potent as ANCA itself. Disrupture of the endothelial F-actin content by botulinum C2 toxin to avoid antigen-antibody internalization did not affect the response. In addition to the metabolic events, anti-PR3 challenge, in the absence of plasma components, provoked delayed, dose-dependent increase in transendothelial protein leakage. We conclude that anti-PR3 antibodies are potent inductors of the preformed phosphoinositide hydrolysis-related signal tranduction pathway in human endothelial cells. Associated metabolic events and the loss of endothelial barrier properties suggest that anti-PR3-induced activation of endothelial cells may contribute to the pathogenetic sequelae of autoimmune vasculitis characterizing WG.

Antibodies, Antineutrophil Cytoplasmic↗

PubMed1998

Unilateral painful legs and moving toes syndrome with moving fingers--evidence for distinct oscillators.

This case report presents a patient with painful legs and moving toes on the right side followed by the development of involuntary movements in his right hand. The frequencies of the semirhythmic muscle activities in both extremities were different. This finding excludes one central pacemaker for both and supports the notion that separate oscillators in the segmental interneuron pool of different spinal areas may drive the individual movements in this case.

Electromyography↗

PubMed1997

Interventional neuropediatrics: treatment of dystonic and spastic muscular hyperactivity with botulinum toxin A.

Therapeutic effect of botulinum toxin A was studied in a group of pediatric patients (n = 28) aged between 6 months and 18 years. The patients were diagnosed with cervical dystonia (n = 6), adductor spasm of the hip (n = 8), spastic drop foot (n = 7) and various other focal motor problems associated with spastic muscular hyperactivity (n = 7). The mean dose of botulinum toxin A (Dysport) used to inject into the affected muscle was 22 U/kg body weight. Reduced muscular hyperactivity with a significant increase in joint mobility was achieved for dystonic (p < 0.0001) as well as for spastic conditions in patients with adductor spasm (p < 0.0002). For these patients the improved joint mobility represented a significant benefit for both daily activities and nursing care. Local paresis and local hematoma were observed in 1/28 and 1/28 patients, respectively; 1/28 patients developed a secondary non-response. However, apart from these side effects, no other adverse reactions to botulinum toxin A treatment were recorded during the treatment and observation period (12-64 months). Our results suggest that botulinum toxin A represents an effective and safe therapeutic substance for the treatment of pediatric patients suffering of focal motor problems due to dystonic or spastic muscular hyperactivity.

Adolescent↗

PubMed1996

[Vitreoretinal operations with local anesthesia].

The objective of this prospective study was to evaluate the intra- and postoperative pain in vitreoretinal surgery under retrobulbar anesthesia (RBA) in 53 patients, considering objective stress parameters such as blood pressure, heart rate and plasma concentration of cortisol (PCC). The level of pain was graded on a standard 4-point nominal scale. Mean pain score after RBA was 1.04, decreased perioperative to 0.77, and increased again with a maximum at 8 h postoperative to 1.15. The quality of RBA significantly correlated with the patient's pain during and at the end of surgery (P < 0.001). At the end of surgery (P < 0.001). At the end of surgery pain also correlated with the duration of surgery (P < 0.01). In 14 patients PCC was measured preoperatively. PCC decreased significantly after oral premedication with Lorazepam (18.4 to 12.6 micrograms/dl, P < 0.001). In the further course of surgery no significant differences in PCC could be detected in 26 patients. Pain during the operation correlated significantly with intraoperative (P = 0.01) and postoperative (P = 0.03) PCC. The objective stress parameters blood pressure and heart rate did not differ significantly during surgery. Of our patients, 77.4% decided that they would choose RBA again in case of ocular surgery.

Adult↗

PubMed1995

Phenotyping of CYP2C19 with enantiospecific HPLC-quantification of R- and S-mephenytoin and comparison with the intron4/exon5 G-->A-splice site mutation.

S-Mephenytoin 4'-hydroxylase (CYP2C19) is a genetically polymorphic cytochrome P450. A modified method for CYP2C19 phenotyping was evaluated in 174 healthy German volunteers and the results were compared with genotyping for the intron4/exon5 G-->A splice site mutation (m1) of CYP2C19, associated with the poor metabolizer (PM) phenotype. A smaller than usual test-dose of 50 mg (R,S)-mephenytoin was used and urine samples were collected from 0 to 5 h and from 5 to 8 h after administration. Trait measurements included the mephenytoin S/R enantiomeric ratio and the hydroxylation index (i.e. the molar ratio of 4'-hydroxy-mephenytoin urinary recovery to the administered S-mephenytoin dose). S- and R-mephenytoin were quantified by isocratic HPLC with a Chiraspher column and 80% n-hexane and 20% dioxane as the mobile phase. All individuals from whom DNA was available (n = 140, including six phenotypically identified PMs) were analysed for the m1 mutation. The population frequency of this CYP2C19 mutation was 0.15. Four individuals were homozygous for m1 having S/R ratios of 0.9 or greater in both intervals of urine collection. Thus, individuals with an S/R ratio > or = 0.9 were classified as PMs and seven of all 174 phenotyped individuals were PMs (4%; 95% confidence limits: 1.6-8.1%). Heterozygous carriers of m1 (n = 34) had a median S/R ratio (5-8 h urine) of 0.06 compared to 0.01 in individuals without this mutation (n = 102; p = 0.0005, Mann-Whitney U-test). No such gene-dose relation was apparent with the hydroxylation index.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine↗