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Biomedical subjects

H Pall

Publications and source records attributed to H Pall.

At least 19 recordsLinked to original sources
PubMed2005

Targeting the subthalamic nucleus for deep brain stimulation: technical approach and fusion of pre- and postoperative MR images to define accuracy of lead placement.

OBJECTIVES: To define the role of magnetic resonance imaging (MRI) and intraoperative electrophysiological recording in targeting the subthalamic nucleus (STN) in Parkinson's disease and to determine accuracy of electrode placement. PATIENTS AND METHODS: We implanted 54 electrodes into the STN in 27 patients. Target planning was done by coordinate guidelines and visualising the STN on MRI and defined in relation to the mid-point of the AC-PC line. Intraoperative microelectrode recording was used. We adjusted electrode positions for placement in the centre of the STN electrical activity and verified this on postoperative MRI in 16 cases, which were fused to the preoperative images to measure actual error in electrode placement in the three axes. RESULTS: Based on coordinate calculation and MRI localisation, the mean of the target was 11.5 mm lateral, 2.5 mm posterior and 4.1 mm inferior to the mid-point of the AC-PC line. Fifty good electrophysiological recordings of the STN (average length 4.65 mm) were achieved and target point adjusted in 90% of lead placements. The mean of the final target after electrophysiological correction was 11.7 mm lateral, 2.1 mm posterior, and 3.8 mm inferior to the mid-point. The distance from the centre of the electrode artefact to the final target used after electrophysiological recording on the fused images was 0.48 mm, 0.69 mm, and 2.9 mm in the x, y, and z axes, respectively. No postoperative MRI related complication was observed. CONCLUSION: Both direct visualisation of the STN on MRI and intraoperative electrophysiological recording are important in defining the best target. Individual variations exist in the location of the STN target. Fewer tracks were required to define STN activity on the side operated first. Our current stereotactic method of electrode placement is relatively accurate.

Adult↗
PubMed2000

Abnormalities in urinary pterin levels in Rett syndrome.

The pterins, neopterin and biopterin, occur naturally in body fluids including urine. Increased neopterin levels are associated with activation of the cellular immune system and reduced biopterins are essential for biosynthesis of the monoamine neurotransmitters. The present study measured urinary neopterin and biopterin by high-performance liquid chromatography in 40 subjects with Rett syndrome, eight of their healthy sisters and 29 female control volunteers (age range 2-54 years). The results confirm earlier preliminary findings that urinary neopterin levels are raised in a proportion of young girls with Rett syndrome but not in the older women. In contrast urinary biopterin levels are not different from controls in the youngest children but remain low while control values increase with age. These findings may indicate immune activation during the regression phase of Rett syndrome but also raise the possibility that an inherited fault in tetrahydrobiopterin metabolism increases the risk of developing the disorder.

Adolescent↗
PubMed2000

Monitoring of 25-OH vitamin D levels in children with cystic fibrosis.

BACKGROUND: Patients with cystic fibrosis are at risk for malabsorption of fat-soluble vitamins, and those with low 25-OH vitamin D levels have a higher risk of low bone mineral density and long-term skeletal complications. It is currently recommended that vitamins A and E be monitored yearly; however, no recommendations exist for 25-OH vitamin D. Because all three vitamins are fat-soluble, the hypothesis in the current study was that low levels of vitamins A and E could identify patients at risk for low 25-OH vitamin D, so that 25-OH vitamin D measurements could be obtained in only selected circumstances. METHODS: Forty (21 girls) patients with CF, age 10.5 +/- 3.9 (SD) years, were assessed in a cross-sectional survey for ideal weight for height (percentage of predicted), spirometry (percentage of predicted FEV1, 33/40 patients), and serum levels of vitamins A, E, 25-OH vitamin D, and cholesterol (37/40 patients). RESULTS: Nine (22.5%) of 40 patients were malnourished (percentage of predicted ideal weight for height <85%), 7 (21.2%) of 33 had moderate to severe lung disease (FEV1 <60%), 4 (10%) of 40 had low levels of vitamin A, 3 (7.5%) of 40 had low vitamin E levels, 4 (10.8%) of 37 low vitamin E/cholesterol levels, and 4 (10%) of 40 had marginal or low levels of 25-OH vitamin D (<40 mmol/l). The patients with low 25-OH vitamin D were older, with no child < 12 years of age having a 25-OH vitamin D level less than 40 mmol/l. They also had lower vitamin E and vitamin E/cholesterol levels than those with normal 25-OH vitamin D levels. The groups did not differ in percentage of predicted ideal weight for height, lung function, or vitamin A levels. The best positive predictor for 25-OH vitamin D less than 40 mmol/l was low vitamin E (66.7%), with a negative predictive value of 94.6%. 25-OH vitamin D levels correlated with vitamin E/cholesterol levels (r = 0.41, P < 0.01) and weakly with vitamin E levels (r = 0.28, P < 0.08), but not with vitamin A levels. CONCLUSIONS: These results suggest that children aged less than 12 years and older children with normal vitamin E levels are especially unlikely to have low 25-OH vitamin D levels, and this measure can therefore be omitted. In contrast, those children with low vitamin E levels may warrant monitoring.

Adolescent↗
PubMed1998

Urinary levels of neopterin and biopterin in autism.

The pterins, neopterin and biopterin, occur naturally in body fluids including urine. It is well established that increased neopterin levels are associated with activation of the cellular immune system and that reduced biopterins are essential for neurotransmitter synthesis. It has been suggested that some autistic children may be suffering from an autoimmune disorder. To investigate this further we performed high performance liquid chromatography analyses of urinary pterins in a group of pre-school autistic children, their siblings and age-matched control children. Both urinary neopterin and biopterin were raised in the autistic children compared to controls and the siblings showed intermediate values. This supports the possible involvement of cell-mediated immunity in the aetiology of autism.

Age Factors↗
PubMed1994

[High altitude pulmonary edema at a medium height. A case report].

A 45-year-old, healthy, well-trained man climbed within 12 hours from 300 m above sea level to a shelter at 2500 m in the Tyrolean Alps. During the following 3 days he undertook ski tours to the surrounding mountains up to 3356 m. On the 4th day he suddenly suffered from headache, coughing and very severe dyspnoea even at rest, accompanied by loss of appetite and the feeling of suffocation. The following day he was rescued by a helicopter and taken to hospital. At the time of admission the patient was severely hypoxaemic (capillary PO2 = 25.7 mmHg), and the chest X-ray revealed signs of bilateral alveolar pulmonary edema localised predominantly in the right lung. High-altitude pulmonary edema (HAPE) was diagnosed because of the typical clinical course. Pulmonary gas exchange normalised within hours, and complete restitution was achieved within 2 days. The chest X-ray was normal on the 4th day after admission. HAPE is a non-cardiogenic pulmonary edema which develops in healthy individuals usually above 3000 m. Among the predisposing factors are rapid ascent, severe physical effort, diminished hypoxic ventilatory response and abnormal fluid balance. The treatment of choice is descent to a lower altitude, administration of oxygen and of nifedipine and expiratory positive airway pressure.

Altitude↗
PubMed1993

An investigation into the role of reactive oxygen species in the mechanism of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity using neuronal cell lines.

The study of oxygen radical generation and effects during 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) metabolism was undertaken in an in vitro test system. Three neurochemically discrete neuronal cell lines, B50 (cholinergic) and B65 rat cell lines and SKNSH human neuroblastoma (both catecholaminergic), were exposed to MPTP (0-200 microM). Parallel experiments were performed using reagent H2O2, an intermediate which may be generated during MPTP metabolism, to determine whether MPTP and H2O2 had any selectivity of toxicity and whether the mechanisms of cell death were similar. MPTP toxicity was shown to be reduced by monoamine oxidase B inhibitors, pargyline (P < 0.01) and selegiline (P < 0.05), indicating that toxicity was due to metabolism of MPTP rather than the parent compound. Cytotoxicity was also decreased in the presence of antioxidants, most notably in the presence of superoxide dismutase and catalase together (P < 0.01), suggesting that reactive oxygen species (ROS) play a role in MPTP-induced cell death. Attempts to determine the intracellular target for oxidative attack did not identify significant levels of lipid peroxidation products, but did demonstrate nucleoid expansion, possibly the result of double stranded DNA breaks induced by ROS.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1992

[Effectiveness and tolerance of amlodipine in treatment of patients with mild to moderate hypertension. Results of a long-term study with a new calcium antagonist].

The efficacy and safety of amlodipine in the long term treatment of outpatients with mild to moderate hypertension were examined in an open, non-comparative study. 87 patients were enrolled in the study, 62 (71%) of whom were observed for 27 months under controlled conditions. Daily doses of 5-10 mg amlodipine led to a statistically significant decrease in systolic and diastolic blood pressure (-30.5/-20.7 mmHg, p less than 0.01) while there was no substantial influence on heart rate or decrease in efficacy. Amlodipine was tolerated very well; only 17% of the patients reported side effects, most of which were either mild or moderate and were tolerated or disappeared with continued treatment. No clinically significant changes were noted in clinical laboratory or ECG examinations. Based on its special pharmacological and pharmacokinetic properties, amlodipine is a novel calcium antagonist from the dihydropyridine class which has proved to be effective in the treatment of hypertension. The antihypertensive effect, which is sustained for more than 24 hours, parallels the circadian variations in blood pressure and thus induces beneficial pharmacodynamic effects. Due to the low incidence of side effects and the once-daily dosage regimen, an improvement in patient compliance can be expected.

Adult↗
PubMed1989

Ocular toxicity of desferrioxamine--an example of copper promoted auto-oxidative damage?

Three patients with rheumatoid disease were given the 'iron chelating' drug desferrioxamine (DFX), which also has an appreciable affinity for copper. The drug was injected cautiously, in lower doses than in patients with thalassaemia, and intramuscularly to evaluate its anti-inflammatory effects. Two of the three patients developed ocular abnormalities. One patient, who also received methyldopa, developed severe but reversible visual failure associated with an abnormal electro-oculogram (EOG); another showed reversible depression of the EOG. Analysis of the cerebrospinal fluid (CSF) of this patient showed an increase in phenanthroline detectable (non-caeruloplasmin-bound) copper. Analysis of the CSF of the third patient, who did not develop any clinical or electrophysiological ocular abnormalities, was normal. Haematological assessments indicated that all three patients probably had reduced iron stores. With in-vitro systems DFX was shown to mobilise copper from albumin and to facilitate copper movement across a cell membrane model, a property that was enhanced by methyldopa. Our observations are consistent with the concept that in rheumatoid patients low iron stores may result in binding of copper by DFX and that this may be of central importance in causing the ocular toxicity of DFX.

Aged↗
PubMed1986

Iron and akathisia.

Explore the source record for details and available documents.

Akathisia, Drug-Induced↗
PubMed1982

Duration of the hypotensive effect of guanfacine.

Guanfacine given intravenously causes a brief rise in blood pressure. This is followed by a sustained decrease of blood pressure, accompanied in one case by a marked orthostatic effect. In addition to its lowering effect on blood pressure, guanfacine also reduces heart rate. The duration of action for up to 72 h is due to the long half-life of the drug. The main side effects observed are fatigue and sedation.

Adult↗
PubMed1980

[Haemodynamic effects after application of nitroglycerin sublingually or as ointment in patients with left ventricular heart failure (author's transl)].

The haemodynamic effects of a 2% nitroglycerin ointment and of sublingual nitroglycerin in patients with left ventricular heart failure were investigated. The well-known pulmonary blood pressure and pulmonary wedge-pressure lowering effect were observed with both forms of administration. Differences exist between onset and duration of the haemodynamic effects. With sublingual administration of nitroglycerin the peak effect was seen after 5 minutes, whilst the pulmonary blood pressure rose again 30 minutes later. After application of nitroglycerin ointment a peak effect was seen 30 minutes later and the effects were sustained for 3 to 6 hours.

Administration, Oral↗
PubMed1979

[Course and intensive treatment of acute falciparum malaria (author's transl)].

The case of a nineteen-year-old women with the cerebral form of malaria tropica is reported. She showed hyperpyrexia, abdominal manifestations, haemolysis and disseminated intravascular coagulation. Cerebral symptoms amounting to grade IV encephalopathy occurred. The patient responded rapidly to the administration of chloroquine, anticonvulsants, dextran, corticosteroids, antipyretics, blood and antithrombin III and her symptoms had almost completely vanished one week after the onset of therapy.

Acute Disease↗
PubMed1979

[Haemodynamic effects of depot zinc protamine glucagon in heart failure (author's transl)].

In contrast to intravenously-administered crystallene glucagon, which acts for 20 minutes only, the depot form, zinc protamine glucagon, shows a prolonged haemodynamic action. Fourteen patients with pre-existing heart failure received a single dose of 20 mg Zn protamine glucagon intramuscularly. The stroke volume and cardiac output were increased, whereas the mean and end-diastolic pulmonary pressure were decreased, indicating a positive inotropic action of the administered drug. Heart rate and mean arterial pressure remained almost unchanged. The haemodynamic changes started 60 minutes after intramuscular administration of the drug, reached a maximum effect at 3 hours and started to decrease after the fourth hour. Zn protamine glucagon can, therefore, be considered a beneficial drug in the treatment of digitalis-resistant heart failure on the basis of its long duration of action and easy route of administration.

Aged↗