Effects of ammonium and aluminium on the development and nutrition of Pinus nigra in hydroculture.

Application of ammonium and aluminium to young Pinus nigra var. maritima (Ait.) Melville trees resulted in a variety of negative effects.

Impact of artificial, ammonium-enriched rainwater on soils and young coniferous trees in a greenhouse. Part II--Effects on the trees.

To obtain an insight into the effects of a high ammonium deposition on trees young, coniferous trees were planted in pots in a greenhouse and treated with artificial ammonium-enriched rainwater. Application of 480 kg ammonium N ha(-1) year(-1) resulted in an increase of the shoot/root ratio. The biomass of fine roots strongly declined, as did the numbers of mycorrhizae.

"Initial-" and "change-orienting reactions": an analysis based on visual single-trial event-related potentials.

The present study was concerned with brain potentials elicited by, respectively, the first of a series of stimuli ("initial-orienting reaction", I-OR), and infrequent deviants ("change-orienting reaction", C-OR). Single-trial event-related potentials (ERPs) to visual stimuli were estimated from recordings at Oz, Pz, Cz and Fz. The design included both a habituation series as well as a series of occasional deviant trials against a background of standards.

Epidural morphine anesthesia for abdominal aortic surgery--pharmacokinetics.

Plasma and CSF pharmacokinetics of morphine given epidurally in combination with general anesthesia for abdominal aortic surgery were recorded. The initial plasma and CSF concentrations of morphine appeared at two minutes. The peak plasma concentrations of morphine were recorded at 8.

Impact of artificial ammonium-enriched rainwater on soils and young coniferous trees in a greenhouse. Part I-effects on the soils.

A pot experiment was used to investigate whether ammonium sulphate, when applied in amounts comparable to those deposited in the Dutch forests, is detrimental to trees. Young coniferous trees were planted in pots and treated with artificial ammonium-enriched rainwater in a greenhouse. The deposition of ammonium resulted in a strong acidification of the soil solution, leaching of base cations and an increased solubility of aluminium, manganese and zinc.

Effect of ICS 205-930 (a specific 5-HT3 receptor antagonist) on gastric emptying of a solid meal in normal subjects.

The effects on gastric emptying of a solid meal of the specific 5-HT3-receptor antagonist ICS 205-930, 10 mg and 20 mg intravenously were assessed with a scintigraphic technique in 12 normals. The 50% emptying time was less, the lag phase was shorter and the post lag emptying rate was faster after 20 mg ICS 205-930 (p less than 0.02).

The pharmacokinetics of intradural morphine in major abdominal surgery.

The pharmacokinetics of intradural morphine used for major abdominal surgery were evaluated. Lumbar spinal fluid and plasma concentrations were measured at intervals after morphine 0.05 mg/kg had been injected intradurally in 21 patients scheduled for elective abdominal aortic surgery.

Iron content and acid phosphatase activity in hepatic parenchymal lysosomes of patients with hemochromatosis before and after phlebotomy treatment.

Lysosomal structures in liver parenchymal cells of 3 patients with iron overload and of 3 subjects without iron-storage disorders were investigated. A combination of enzyme cytochemistry--with cerium as a captive ion to demonstrate lysosomal acid phosphatase activity--and electron probe X-ray microanalysis (EPMA) was used. We were able (1) to define and quantify lysosomal structures as lysosomes, siderosomes, or residual bodies, (2) to quantify the amount of iron and cerium simultaneously in these structures, and (3) to evaluate a possible relation between iron storage and enzyme activity.

The effect of changes in dietary sodium content on complaints and clinical parameters of volume depletion in patients with a permanent ileostomy.

In seven patients with an ileostomy the volume and electrolyte composition of ileal effluent and urine were studied at the end of 7-day periods on a free diet (mean total sodium excretion 180 mmol/day) and on diets with a fixed sodium content ranging from 120 to 350 mmol/day. At the same time, complaints were scored and the plasma aldosterone concentration, renal aldosterone excretion, and ileal transmucosal potential difference were determined. On a free diet, all of the patients had one or more complaints.

The analysis of multiple habituation profiles of single trial evoked potentials.

A new statistical technique for the analysis of multiple habituation profiles of single trial evoked potentials is presented. The method is based on a model that highlights the essential characteristics of the habituation process, viz. trial-dependent modulation of amplitude and phase of the underlying brain responses to a repeated stimulus, while recognizing the presence of unsystematic background variation inherent to single trial registrations.

Computer aided analysis of electrical and mechanical activity of stomach and duodenum.

In studies of gastroduodenal motility several imaging techniques and also recordings of signals of implanted transducers are used. Combination of methods and prolonged observation times produce so much information that an automatic analysis is advantageous, the more so because more complex parameters can be analysed. Using a desktop computer, it is possible to analyse long time-series of antral and duodenal signals, obtained with implanted electrodes and strain gauges.

Gastric emptying and postprandial symptoms after Billroth II resection.

Gastric emptying was studied in 18 symptomatic and 16 asymptomatic patients after Billroth II (BII) resection (without vagotomy) and the possible relationships between emptying and postprandial symptoms in these patients were assessed. The BII patients were compared with 20 nonoperated patients who had duodenal ulcer disease and 16 healthy subjects. Gastric emptying of two test meals (a semisolid porridge meal and a solid pancake meal) was measured with a radionuclide technique.

Electrical stimulation of bone growth with direct current.

Electrical stimulation of osteogenesis was studied in rabbit femora in: (A) a transcortical electric field with a cortex-depolarizing or hyperpolarizing orientation derived from an intramedullary electrode and a ring-shaped counter electrode encircling the femoral shaft; and (B) an electric field derived from an electrode located in the medullary canal and the counter electrode in the abdominal wall. Electrodes were made of platinum. A direct current of 20 microA was applied during six weeks.

Habituation of early and late visual ERP components and the orienting reaction: the effect of stimulus information.

Single trial event-related potentials at Fz, Cz, Pz and Oz were measured concurrently with pupil reactions and skin conductance reactions in a habituation paradigm. One group of subjects (n = 16) was given 36 simple visual stimuli and a second group (n = 16) 36 complex visual stimuli of equal duration, brightness and dimensions. No task-relevance was given to the stimuli.

Integrated image and X-ray microanalysis of hepatic lysosomes in a patient with idiopathic hemosiderosis before and after treatment by phlebotomy.

Morphometrical and X-ray elemental information was extracted from Scanning Transmission Electron Microscopy (STEM) images of hepatic lysosomes of a patient with idiopathic hemosiderosis before and after treatment by phlebotomy. The elements of interest were iron, stored in pathological quantities in hepatic lysosomal structures and cerium, used as a capture ion after a cytochemical reaction to detect acid phosphatase activity in the lysosomal structures. Morphologically the lysosomal structures are heteromorph and the elements iron and cerium are heterogeneously distributed.

Does the metabolite uracil arabinoside inhibit cytosine arabinoside (Ara-C) penetration into the cerebrospinal fluid during high-dose Ara-C therapy?

A patient with acute leukaemia was treated with i.v. 2-h infusions of Ara-C at a dose of 3.

The distribution of (5E)-(10S)-10,19-dihydroercalciol and its metabolites in serum of rats.

The distribution of radioactivity in serum of male rats (275 g) after oral administration of tritium labelled (5E)-(10S)-10,19-dihydroercalciol (dihydrotachysterol2) has been studied as a function of time and dose level. Nine distinct radioactive substances, chromatographing in the range between calciol and calcitriol, could be demonstrated. No attempt was made to establish chemical structures.

Distribution of dendritic reticulum cells in follicular lymphoma and reactive hyperplasia. Light microscopic identification and general morphology.

Reactive and neoplastic follicles in lymph nodes showing changes of (1) follicular hyperplasia and (2) follicular lymphoma were examined for the presence of dendritic reticulum cells (DRC). These cells could be identified under the light microscope after comparing electron microscopical sections with subsequent 1 micro sections of reactive germinal centres. Quantitative light microscopical evaluation showed that DRC, both mononuclear and binuclear forms, were less numerous in neoplastic follicular structures than in reactive follicles.

A rapid method for preparing undecalcified sections of bone for autoradiographic investigation with short-lived radionuclides.

To prepare sections of undecalcified bone suitable both for autoradiography with short-lived radionuclides such as 99m-technetium (t 1/2 = 6 hr) and for normal histology, rapid processing is necessary. By modifying the routine technique of embedding in plastic, sections can be obtained within 6 hours. The most important modification concerns the temperature used for the different steps in the process.

Kinetics of intravenously administered heparin in normal humans.

Heparin of five commercially available brands was used to study the disappearance of heparin anticoagulant activity in normal humans. The drug was administered intravenously by bolus injection and by continuous infusion. Heparin anticoagulant activity was determined by two assays: a diluted activated partial thromboplastin time (APTT) and an assay based on inactivation of bovine factor Xa, using a clotting system.