PubMed Health⌕ Search

Biomedical subjects

C Uhl

Publications and source records attributed to C Uhl.

13 recordsLinked to original sources
PubMed2006

Efficacy of short term continuous subcutaneous insulin lispro versus continuous intravenous regular insulin in poorly controlled, hospitalized, type 2 diabetic patients.

UNLABELLED: Intravenous insulin infusion (IVII) is rapidly effective in improving glycaemia in uncontrolled hospitalized diabetic patients. This significantly improves their morbidity and mortality. Intravenous insulin infusion may lead to IV infusion complications and is a heavy burden for caregivers. AIM: The aim of our work was to compare the efficacy of IV regular insulin versus lispro Continuous Subcutaneous Insulin Infusion (CSII), in improving glycaemia in patients hospitalized for uncontrolled type 2 diabetes, the efficacy being assessed on the average blood glucose level observed. METHODS: The study was designed as a prospective randomized study. Thirty-three type 2 diabetic patients, hospitalized for uncontrolled diabetes by their usual practitioner were included. After acceptation, patients were randomly assigned to lispro CSII (group 1, n=20) or IVII regular insulin (group 2, n=13) for 5 days. Ten capillary blood glucose/day were performed. Pre-meal blood glucose targets were 4.4-6.6 mmol/l. Mann Whitney, Wilcoxon and Fischer exact tests were used. RESULTS: BG levels decreased significantly (-3.4+/-0.55 mmol/l in group 1 and -3.60+/-0.55 mmol/l in group 2, P<0.01) during the first 12 hours. Mean daily blood glucose at day 5 was statistically improved in both groups compared to day 1 (P<0.05 Wilcoxon) and comparable between the 2 groups. No severe hypoglycaemia was reported. No catheter complications occurred in group 1, 7 occurred in group 2. CONCLUSION: CSII and IVII infusion were comparable in rapidly improving hyperglycaemia in uncontrolled type 2 diabetic patients. CSII, being more convenient, could be preferred in medical and surgical settings.

Blood Glucose↗
PubMed2001

Improvement of source localization by dynamical systems based modeling (DSBM).

Recently, we have proposed a new concept for analyzing EEG/MEG data (Uhl et al. 1998), which leads to a dynamical systems based modeling (DSBM) of neurophysiological data. We report the application of this approach to four different classes of simulated noisy data sets, to investigate the impact of DSBM-filtering on source localization. An improvement is demonstrated of up to above 50% of the distance between simulated and estimated dipole positions compared to principal component filtered and unfiltered data. On a noise level on which two underlying dipoles cannot be resolved from the unfiltered data, DSBM allows for an extraction of the two sources.

Algorithms↗
PubMed2001

High antigenicity of intraperitoneal insulin infusion via implantable devices: preliminary rat studies.

Intraperitoneal insulin infusion of Genapol stabilized insulin via implantable devices significantly improves diabetes control and hypoglycemia frequency in type 1 diabetes while it increases insulin antibody levels. Causes for this particular antigenicity remain unknown. The role of insulin modifications occurring in the reservoir on the antigenicity observed was assessed by comparing the antigenicities of the insulin coming from the vial or from the pump reservoir. Rats were injected intraperitoneally with insulin sampled either from a vial (group 1) or from a pump reservoir during a refill of a clinical trial (group 2). Two control groups, one without insulin, the second one receiving a mixture of silicone and insulin were also studied. Human insulin antibody levels were assessed by RIA 10 days after 4 weekly immunizations. AIA levels were higher in group 1 compared to group 2 (P = 0.003 for the first experiment, P = 0.04 in the second experiment). The increased antigenicity of the insulin sampled from the implanted pump might be due to the insulin modifications occurring during the storage in the device. Insulin aggregates could be involved in this antigenicity since they are known to be antigenic and their concentration was shown to be related to the amplitude of the antigenic response.

Animals↗
PubMed1999

Analysis of spatiotemporal signals: a method based on perturbation theory.

We present a method of analyzing spatiotemporal signals with respect to its underlying dynamics. The algorithm aims at the determination of spatial modes and a criterion for the number of interacting modes. Simultaneously, a way of filtering of nonorthogonal noise is shown. The method is discussed by examples of simulated stable fixpoints and the Lorenz attractor.

Journal Article↗
PubMed1998

A new concept for EEG/MEG signal analysis: detection of interacting spatial modes.

We propose a new concept for analyzing EEG/MEG data. The concept is based on a projection of the spatiotemporal signal into the relevant phase space and the interpretation of the brain dynamics in terms of dynamical systems theory. The projection is obtained by a simultaneous determination of spatial modes and coefficients of differential equations. The resulting spatiotemporal model can be characterized by stationary points and corresponding potential field maps. Brain information processing can be interpreted by attraction and repulsion of spatial field distributions given by these stationary points. This allows an objective and quantitative characterization of the brain dynamics. We outline this concept and the underlying algorithm. Results of the application of this method to an event related potential (ERP) study of auditory memory processes are discussed.

Algorithms↗
PubMed1997

Human platelet Ca2+ mobilization, glycoprotein IIb/IIIa activation, and experimental coronary thrombosis in vivo in dogs are all inhibited by the inotropic agent amrinone.

BACKGROUND: Inotropic drugs are often used to treat acute, severe heart failure resulting from acute myocardial infarction and other unstable coronary artery syndromes. However, catecholamine inotropic agents may potentiate coronary thrombosis via a platelet alpha2-adrenergic mechanism, thus exacerbating the original problem. The present studies were designed to determine whether the nonadrenergic inotropic and vasodilator drug amrinone, which elevates platelet cAMP levels, would both inhibit human platelet Ca2+ mobilization and adhesion molecule expression ex vivo and protect against experimental coronary thrombosis in vivo in dogs. METHODS AND RESULTS: Human platelets in suspension were preincubated with amrinone 2.5 to 15 microg/mL; stimulated with the agonists thrombin 0.1 U/mL, ADP 10(-6) mol/L, or arginine vasopressin 10(7) mol/L; and studied for Ca2+ mobilization, glycoprotein IIb/IIIa activation, and P-selectin expression by fluorescent flow cytometry methods. Experimental coronary thrombosis in vivo was studied in an open-chest dog model with critical coronary artery stenosis and deep vessel wall injury. Results showed that at the cellular level, amrinone inhibited agonist-induced Ca2+ mobilization and had modest inhibitory effects on adhesion molecule expression. In vivo in dogs, intravenous amrinone 2 mg/kg plus infusion at 20 microg x kg(1) x min(-1) completely abolished coronary thrombosis. CONCLUSIONS: The fact that amrinone inhibited human platelet activation at the cellular level and protected against experimental coronary thrombosis in vivo in dogs suggests a potentially advantageous antithrombotic action for this inotropic and vasodilator drug.

Amrinone↗
PubMed1991

Halothane inhibits agonist-induced inositol phosphate and Ca2+ signaling in A7r5 cultured vascular smooth muscle cells.

Halothane, an anesthetic with marked depressant effects on the circulation, was studied for its ability to inhibit inositol phosphate and Ca2+ signaling evoked by the vasoactive hormone arginine vasopressin (AVP) and Ca2+ responses elicited by platelet-derived growth factor and by thapsigargin in cultured A7r5 vascular smooth muscle cells. Changes in apparent [Ca2+]i were measured using the indicator indo-1 and flow cytometry, whereas inositol phosphate levels were determined using myo-[3H]inositol and column chromatography. Preincubation with clinically relevant concentrations of halothane resulted in dose-dependent depression of [Ca2+]i responses evoked on stimulation with AVP. Halothane (2.0%) inhibited the increases in [Ca2+]i by 34-45%. In cells incubated in Ca(2+)-free medium plus 0.5 mM ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, the halothane effect was more marked, with 1.5% halothane inhibiting the responses by approximately 53-61%. However, when Ca2+ influx was stimulated by addition of 5 mM Ca2+ in the continued presence of the agonist, the [Ca2+]i response was inhibited by only 15%, suggesting that release of Ca2+ rather than Ca2+ influx is more sensitive to inhibition by the anesthetic. The effects of halothane on Ca2+ homeostasis are not explained solely by anesthetic-induced depletion of Ca2+ from intracellular stores, because the anesthetic inhibited increases in [Ca2+]i elicited by thapsigargin in cells suspended in Ca(2+)-free medium by only 31%. Halothane inhibited inositol phosphate formation elicited by AVP, suggesting an additional means by which the anesthetic may alter agonist-induced Ca2+ responses. The current results also demonstrate that halothane actions are not specific solely to responses evoked by AVP, which acts via a guanine nucleotide-binding protein-linked signaling pathway, but include responses stimulated by platelet-derived growth factor, an agonist that elevates [Ca2+]i via receptor-latent tyrosine kinase activity. The current results demonstrate that, in vascular smooth muscle cells, halothane alters Ca2+ homeostasis, an action that may underlie the in vivo vasodilator effects of the anesthetic.

Animals↗
PubMed1991

[Standardized determination of pressure tolerance of the optic nerve head].

The early diagnosis of glaucoma relies on the detection of manifest damage in present-day clinical practice. The reason for such damage in glaucoma may be seen in the breakdown of the autoregulation of the circulation in the optic nerve head. This autoregulation can be assessed by the pressure tolerance test devised by ourselves which may detect glaucoma before manifest damage can occur. We demonstrate a standardized method in which the test procedure is controlled by a computer. In particular, the time course of the examination which is of crucial importance is exactly defined. The method is no more difficult to apply than automatic perimetry. We describe six examinations in seven subjects each. The results are analyzed by the estimation of variance components. The intraocular pressure shows an intraclass correlation of 0.41 and the critical pressure an intraclass correlation of 0.27. The intraindividual variability of critical pressure is mainly due to the widely known variability of intraocular pressure. The autoregulation behavior shows a very good constancy, which makes the test clinically useful in the differential diagnosis of glaucoma.

Adult↗