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Biomedical subjects

S Stiller

Publications and source records attributed to S Stiller.

At least 19 recordsLinked to original sources
PubMed2000

A randomized trial of magnesium in the emergency department treatment of children with asthma.

STUDY OBJECTIVE: Magnesium sulfate has been shown to benefit asthmatic children and adults with poor responses to initial beta(2)-agonist therapy in the emergency department. We sought to determine whether the routine early administration of high-dose magnesium would benefit moderate to severely ill children with acute asthma. METHODS: This was a randomized, double-blind, placebo-controlled trial of 54 children 1 to 18 years of age who presented to the ED of a tertiary care children's hospital with a moderate to severe asthma exacerbation. After receiving a nebulized albuterol treatment (0.15 mg/kg) and methylprednisolone (1 mg/kg), patients were randomly assigned to receive either 75 mg/kg of magnesium sulfate (maximum 2.5 g) or placebo. Thereafter, all patients were treated with frequent nebulized albuterol following a structured protocol. The main outcome was degree of improvement as assessed by Pulmonary Index scores over 120 minutes. Secondary outcomes included hospitalization rates and time required to meet discharge criteria. RESULTS: The mean change in Pulmonary Index score from baseline to 120 minutes was 2.83 for the magnesium group compared with 2.66 for the placebo group (95% confidence interval -1. 24 to 1.60). Eleven (46%) of 24 magnesium-treated patients were hospitalized compared with 16 (53%) of 30 in the placebo group (95% confidence interval -19% to 34%). There were no statistically significant differences between the groups with respect to time required to meet discharge criteria. CONCLUSION: The routine administration of high-dose magnesium to moderate to severely ill children with asthma, as an adjunct to initial treatment with albuterol and corticosteroids, was not efficacious.

Adolescent↗
PubMed2000

Sodium modeling.

The most serious side effects induced by hemodialysis therapy are caused by changes in sodium concentration and subsequent water shift between the intracellular and extracellular fluid compartment. Because of inadequate precision of proportioning, a certain sodium concentration and considerable error in the measurement of sodium concentration in dialysis fluid and plasma water, an error of up to 10 g in the diffusive exchange of sodium chloride remains in most dialysis sessions. Common side effects occur within this sodium balance error. Sodium modeling is a simplified mathematical method to describe quantitatively the fluid exchange in the body caused by changes in extracellular sodium concentration. It is based on fundamental physiologic properties of sodium and its permeability through the corresponding membranes. It also explains the different working mechanisms of sodium- and urea-related changes in osmolarity. Sodium modeling is a helpful tool for the illustration of the effects of changes in sodium concentration and ultrafiltration rate on sodium balance during one dialysis session. Sodium profiling is a method employed to avoid unwanted side effects of hemodialysis therapy by deliberately changing the sodium concentration in dialysis fluid during the course of a dialysis session. Clinical reports on practicing sodium profiling are unsatisfactory, involving only short trial periods in most cases. Most of the studies reported positive sodium balance with temporary decreases in intradialytic hypotension and less blood volume reduction, but with increases in thirst and body weight. To date, no validated studies with suitable control of sodium balance have been published that clearly demonstrate the long-term benefits of this mode of therapy compared with the use of constant dialysate sodium concentrations.

Humans↗
PubMed1999

Importance of sodium dodecyl sulfate pore-graduated polyacrylamide gel electrophoresis in the differential diagnostic of Balkan nephropathy.

Balkan nephropathy (BN) is an endemic disease, which leads to end-stage renal failure and artificial renal replacement therapy. Pathologically it is characterized by progressive interstitial nephritis in a large population of villages situated in the proximity of a bend of the Danube up to a distance of 100 km from the river in several parts of Bulgaria, Romania, and the former Yugoslavia. The urinary proteins of 19 patients with BN from the region of Vratza, Bulgaria were examined using ultrathin layer sodium dodecyl sulfate (SDS) pore-graduated polyacrylamide gel electrophoresis (PAGE) and silver staining. The documentation of urinary proteins pattern was performed using laser densitometry and consecutive electronic processing for the purpose of characterizing and quantifying protein excretion. Our results show that the proteinuria of BN is predominantly tubular, consisting of low molecular weight species (10-65 kilodaltons). The amount of tubular protein changes with the progression of the disease. SDS-polyacrylamide gel electrophoresis (PAGE) is a diagnostic method for early diagnosis of tubular failure in BN. Using our method of SDS-PAGE, tubular failure can be detected even at a total protein concentration below 0.1 g/L and when the serum creatinine concentration is normal. Additionally, our method of SDS-PAGE supports the differentiation of BN from glomerular disease.

Aged↗
PubMed1997

Rectal administration of N-acetylcysteine in swine: a pilot study.

The purpose of this pilot study was to determine if N-acetylcysteine (NAC) administered via the rectal route in swine is absorbed into the systemic circulation. Fasting swine were anesthetized, intubated, monitored and i.v. access was obtained by femoral cutdown. NAC was administered into the rectal vault (2.0 g/kg) via a balloon-tipped Foley catheter inserted into the animals' rectum. NAC administered via the rectal route resulted in systemic absorption as determined by spectrophotometric methods in 5 of the 7 study animals. This study provides important information regarding the development of a potential alternative route for the administration of NAC.

Absorption↗
PubMed1990

Kinetic modelling and continuous on-line blood volume measurement during dialysis therapy.

Changes of relative blood volume during haemodialysis therapy have been investigated using kinetic modelling and on-line blood volume registration by continuous haemoglobinometry. An exponential relation has been found between blood volume reduction per litre of ultrafiltrate and the amount of fluid overload. Between the amount of refilling and ultrafiltration rate there was also an exponential dependence. There was a linear relation between the change in plasma sodium concentration and blood volume. An acceptable correspondence was found between calculated and measured data.

Blood Volume↗
PubMed1990

Short time dialysis with continuous blood volume control.

Continuous measurement of haemoglobin concentration is used to control changes of blood volume during haemodialysis. Ultrafiltration is either kept constant throughout the session or after starting with a rate (1.5 to 2 l/h), is manually controlled in order to limit blood volume reduction to a pre-set percentage. Ultrafiltration is step-wise decreased (a) or switched on and off (b) accordingly. Blood volume decrease with constant ultrafiltration is compared with method (a) and (b) in 4 stable haemodialysis patients. Constant ultrafiltration rate and the same total amount of ultrafiltrate causes a nearly 3% (mean) greater volume reduction as compared with method (a) and (b). No difference was observed in blood pressure and heart rate. We conclude that ultrafiltration in stable haemodialysis patients can be completed in short time without consequences for cardiovascular stability.

Blood Pressure↗
PubMed1985

Ionometry versus flame photometry in dialysis therapy.

In order to decide whether the ionometer can be accepted as an alternative to the flame photometer in the measurement of sodium and potassium, extensive measurements with ionometry in parallel with flame photometry were performed in serum and dialysis fluid during dialysis. The influence of parameters which influence both ionometry and flame photometry in a different way (protein concentration, pH, acetate, and bicarbonate concentration) was investigated. The correlation between the two methods for potassium in serum and dialysis fluid was excellent (r greater than 0.95), but unsatisfactory for sodium in serum (r = 0.77) and in dialysis fluid (r less than 0.85). This low correlation is attributed in a greater extent to the random errors caused by flame photometry than by ionometry. Ionometry can be accepted as an alternative to flame photometry in dialysis therapy.

Evaluation Studies as Topic↗
PubMed1983

Electrodialysis and reverse osmosis as a regeneration system for hemofiltrate.

The separation of urea from the hemofiltrate (or from spent dialysis fluid) must be considered the critical step in all regeneration systems. A promising solution for this problem is the combination of electrodialysis and reverse osmosis. A mathematical stimulation of the process and in vitro experiments have been carried out in order to determine operating conditions and design specifications. The experiments confirmed the predicted performance of the regeneration system with respect to the separation of urea and the recovery of electrolytes. As expected, some ionic toxins, such as uric acid, and some middle molecules are recovered also. These substances, however, can be easily removed by a small adsorption cartridge.

Adsorption↗
PubMed1978

Theoretical aspects of various ultrafiltration methods in artificial kidney therapy.

A mathematical model including urea, creatinine and other osmotically important solutes (such as sodium, potassium and chloride) is applied to calculate volume shifts, caused by ultrafiltration, between the fluid compartments of the body. The volume shifts between the intracellular (ICV) and the extracellular (ECV) compartments are mainly caused by alteration of extracellular sodium concentration. Various methods of achieving ultrafiltration, including conventional dialysis, initial ultrafiltration using Cuprophan (without dialysis) or hemofiltration, produce different responses. In choosing a method, one must consider that both a rapid decrease of ECV and a fast shift of water from ICV to ECV should be avoided. In pure hemofiltration, ultrafiltrate is isotonic and water is removed from ECV only. Hemofiltration with dilution produces a very slow shift of water between ICV and ECV dependent on sodium concentration of plasma and diluting fluid. In initial ultrafiltration through Cuprophan, water is shifted from ICV to ECV. With ultrafiltration throughout the entire dialysis, there are pronounced shifts between ICV and ECV dependent on the difference of the sodium concentration between plasma and dialysate.

Biological Transport, Active↗