Biomedical subjects

T Pieper

Publications and source records attributed to T Pieper.

8 recordsLinked to original sources

PubMed2002

Epilepsy surgery in children with focal cortical dysplasia (FCD): results of long-term seizure outcome.

The purpose of this study was to assess the effect of epilepsy surgery on seizure outcome in children and adolescents under 18 years with intractable epilepsy due to focal cortical dysplasia. We analysed clinical data, such as age at seizure onset, epilepsy course, localisation of focus from presurgical evaluation, MRI, tissue pathology and seizure outcome in 68 patients 6 months to 9 years after epilepsy surgery. Seizure outcome was classified according to the Engel classification. Mean age at seizure onset was 7 months, ranging from the first days of life to 7 years. All patients had medically intractable epilepsy. Localisation of the lesion was predominantly extratemporal: posterior (uni- or multilobar) 43 %, frontal without central region 26 %, multilobar involving central area 19 % and temporal in 12 %. MRI signs typically seen in cortical dysplasia (FCD) such as localised blurring of gray-white matter junction was found in 68 %, dysgyria in 62 %, thickening of the cortical ribbon in 46 % and T2 signal elongation of the subcortical white matter in 40 % of the patients' MRI. Age at surgery ranged from 5 months to 16 years; 14 patients were under 2 years when operated on. In 34 patients (6 patients under 3 years) subdural grid electrode evaluation was performed prior to surgery. Pathology revealed focal cortical dysplasia without balloon cells (type I) in 60 %, FCD of the balloon cell subtype (type II) in 40 % of the specimens. Postoperative complications were subdural hygroma in 5 and an increased motor deficit in 2 patients. Up to two years after epilepsy surgery 50 % of the children were seizure free (Engel class I), 10 % Engel class II, 33 % Engel class III and 7 % unchanged (Engel class IV). Long-term seizure outcome (> 3 years post surgery) in 32 patients showed similar results (class I 50 %, class II 19 %, class III 28 %, class IV 3 %). Complete resection of the dysplastic lesion was significantly correlated with favorable seizure outcome, whereas seizure outcome was not significantly different in patients with mild (type I) or balloon cell (type II) FCD. Children operated after 6 years of age had no better outcome than children operated in infancy or at preschool age. Epilepsy surgery resulted in good (class I and II) seizure control in 60 % of children with intractable epilepsy due to focal cortical dysplasia.

Adolescent↗

PubMed2001

Investigations into the interaction between tumor-inhibiting ruthenium(III) complexes and nucleotides by capillary electrophoresis.

Ruthenium(III) complexes of the general formula HL[RuCl4L2], with two trans-standing heterocyclic ligands L bound to ruthenium via nitrogen, show remarkable activity in different tumor models. To obtain a deeper insight into the mode of action of this class of anticancer compounds, we investigated the interaction of HIm trans-[RuC14(im)2] (im, imidazole) and HInd trans-[RuCl4(ind)2] (ind, indazole) with all four nucleoside monophosphates in buffered solution by means of capillary electrophoresis. A preference for GMP- and AMP-coordination was found. A decrease of the pH resulted in a significantly increased amount of bound nucleotide. This feature seems to be interesting with regard to the lower pH values in solid tumors.

Adenosine Monophosphate↗

PubMed2001

Hydrolysis of the tumor-inhibiting ruthenium(III) complexes HIm trans-[RuCl4(im)2] and HInd trans-[RuCl4(ind)2] investigated by means of HPCE and HPLC-MS.

High performance capillary electrophoresis (HPCE) as well as high performance liquid chromatography-mass spectrometry (HPLC-MS) have been applied to the separation, identification and quantification of the tumor-inhibiting ruthenium compounds HIm trans-[RuCl4(im)2] (im = imidazole) and HInd trans-[RuCl4(ind)2] (ind = indazole) and their hydrolysis products. The half-lives for the hydrolytic decomposition of the Ru(III) compounds were determined by monitoring the relative decrease of the original complex anion under different conditions by means of capillary electrophoresis. The decomposition follows pseudo-first-order kinetics. The rate constants in water at 25 degrees C are 1.102 +/- 0.091 x 10(-5) s-1 for HIm trans-[RuCl4(im)2] and 0.395 +/- 0.014 x 10(-5) s-1 for HInd trans-[RuCl4(ind)2]. About 8% of HIm trans-[RuCl4(im)2] but only about 2% of HInd trans-[RuCl4(ind)2] were hydrolyzed after 1 h at room temperature. Whereas the hydrolysis rate of the imidazole complex is independent of the pH value, the indazole complex hydrolyzes much faster at higher pH. The half-life of HInd trans-[RuCl4(ind)2] in phosphate buffer at pH 6.0 and 37 degrees C is 5.4 h, whereas it is less than 0.5 h at pH 7.4. In contrast to the imidazole complex, where no dependence on the buffer system was observed, hydrolysis of the indazole complex is even faster if a buffer containing hydrogen carbonate is used. The formation of [RuCl2(H2O)2(im)2]+ could be demonstrated by HPLC-MS measurements. In the case of the indazole complex, a release of the indazole ligands results in the formation of [RuCl4(H2O)2]-.

Antineoplastic Agents↗

PubMed2001

A detailed analysis of frontal lobe seizure semiology in children younger than 7 years.

PURPOSE: We sought to analyze semiology of seizure onset and evolution in young children with frontal lobe epilepsy (FLE), compare this with adult reports, and assess age-related differences. METHODS: We analyzed 111 videotaped seizures from 14 patients with FLE based on focal cortical dysplasia aged 3-81 months (mean, 30 months). Ictal events were categorized into behavioral, consciousness, autonomic, and sensory features, as well as motor patterns, which included tonic, clonic, epileptic spasm, and myoclonic seizure components. We developed a time-scaled datasheet to record each epileptic event as onset, very early, early, or late manifestation. RESULTS: Patients had a high seizure frequency with up to 40 attacks/day; half of them showed a cluster tendency. Forty-seven percent of the seizures started in sleep. Mean duration of seizures was short (29 s). Most common seizure components were motor manifestations, mostly tonic-clonic seizures, and epileptic spasms. Behavioral change was frequent, and hypermotor seizures were not seen. In five patients, the motor features were contralateral to the epileptic focus, including two children with asymmetric epileptic spasms. Secondarily generalized tonic-clonic seizures (SGTCSs) were not recorded, but had been reported in the history of two patients. Complex motor automatisms were not seen, whereas oral automatism appeared in three children. CONCLUSIONS: Motor features are common in young children with FLE, as reported in adults. The characteristics, however, differ. Epileptic spasms and subtle behavioral change were frequent. Hypermotor seizures and complex motor automatisms were not seen, and SGTCSs were unusual. Our results suggest that FLE in young children shows age-related features differing from those of adults.

Adult↗

PubMed2001

Functional MRI in a 6-year-old boy with unilateral cortical malformation: concordant representation of both hands in the unaffected hemisphere.

Functional magnetic resonance imaging (fMRI) was performed in a 6-year-old boy with a complex malformation of the right hemisphere who suffered from pharmaco-refractory epilepsy. Clinical examination revealed left-sided hemiparesis and marked mirror movements of the opposite hand both during paretic and non-paretic hand movements. Functional MRI of repetitive unimanual grasping demonstrated that the two hands share a common cortical representation located in the central motor region of the unaffected left hemisphere. The affected right hemisphere did not show any activation during either task. This case study demonstrates the feasibility and usefulness of motor fMRI in young children before they undergo epilepsy surgery.

Brain Mapping↗

PubMed2000

Association of endotoxemia and production of antibodies against endotoxins after multiple injuries.

BACKGROUND: Endotoxemia after injury has been a controversial issue. Endotoxins stimulate the innate and adaptive immune system. OBJECTIVE: To investigate endotoxemia and its effects on the production of antiendotoxin antibodies of cultured mononuclear cells of patients with multiple injuries. METHODS: Blood samples of 20 patients with multiple injuries were collected up to 12 days after trauma. The endotoxin concentration was measured in the plasma, and mononuclear cells were isolated and cultured. Specific antibodies against two lipopolysaccharides, one lipid A preparation, and alpha-hemolysin of Staphylococcus aureus were measured in the cell culture supernatant by an enzyme-linked immunosorbent assay. RESULTS: Endotoxemia peaked at admission of the patients, decreasing thereafter to almost normal values within 5 days. Isolated mononuclear cells synthesized antibodies against all tested antigens with a peak at or between day 5 and day 7. The increase was significant for immunoglobulin (Ig)A and IgM specific to all endotoxins tested and for IgA specific to alpha-hemolysin. However, there were no significant changes of the concentrations of total IgM, IgA, and IgG. All specific IgG remained unaffected. CONCLUSION: Patients with multiple injuries initially have temporary endotoxemia. Endotoxin may be suggested as a stimulator of the synthesis of antiendotoxin antibodies, in particular of the IgA and IgM class in patients with multiple injuries.

Adult↗

PubMed1999

Benign epileptic discharges in patients with lesional partial epilepsies.

Case reports of four patients with therapy-resistant lesional partial epilepsies and additional foci of benign epileptic discharges of childhood, in addition to the usual electroencephalogram (EEG) changes, are presented. A family history of epileptic or febrile seizures in childhood was reported in all four patients. A distant relative of one patient, not manifesting seizures, demonstrated rolandic spikes on EEG. An abnormal pregnancy (polyhydramnion, premature pains, induced labor because of an abnormal CTG , placenta insufficiency) was reported in one patient, risk factors during birth (birth 14 days after term, placenta insufficiency) were reported in one, and bacterial meningitis at 4 weeks of age was reported in one. All patients manifested a retarded, partly severe, unfavorable infantile psychomotor development. An early seizure onset was observed in all patients (in three patients during the first year of life and in one patient during the second year). A hemifacial seizure symptomatology was seen, in addition to other symptoms, in two patients, possibly indicating the seizure pattern indicative of benign partial seizures; seizures occurred exclusively in sleep in one patient. The benign focus was never located in the lesional area. It was recorded over the same hemisphere in two patients and over the other hemisphere in the other two.

Cerebral Cortex↗

PubMed1994

[Not Available].

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Affective Disorders, Psychotic↗