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Biomedical subjects

J Krug

Publications and source records attributed to J Krug.

At least 37 records · Page 2Linked to original sources
PubMed2000

Umbilical artery catheter blood sampling decreases cerebral blood volume and oxygenation in very low birthweight infants.

UNLABELLED: The aim of this study was to assess whether blood sampling from umbilical artery catheters reduces cerebral blood volume and cerebral oxygenation in very low birthweight infants. A total of 20 infants, median birthweight 890 g (530-1,500 g), median gestation age 26 +4 wk (range: 22 +5 to 30 +6 wk) were studied from 10 min before until 10 min after routine blood sampling from umbilical artery catheters placed in the high position. Using near infrared spectroscopy, changes in concentrations of cerebral oxygenated and deoxygenated haemoglobin were measured, and changes in cerebral blood volume and cerebral oxygenation index were calculated. Heart rate, oxygen saturation, transcutaneous PO2 and PCO2 were registered continuously. Mean arterial blood pressure was measured before and after sampling. Oxygenated haemoglobin decreased significantly from baseline during blood sampling, whereas deoxygenated haemoglobin did not change significantly. This resulted in a decrease in cerebral blood volume and cerebral oxygenation index. Heart rate increased slightly, but significantly, from baseline. Oxygen saturation, blood pressure, transcutaneous PO2 and PCO2 did not change significantly. CONCLUSION: Blood sampling from umbilical artery catheters induces a significant decrease in cerebral blood volume and cerebral oxygenation.

Analysis of Variance↗
PubMed1999

Fast coarsening in unstable epitaxy with desorption.

Homoepitaxial growth is unstable towards the formation of pyramidal mounds when interlayer transport is reduced due to activation barriers to hopping at step edges. Simulations of a lattice model and a continuum equation show that a small amount of desorption dramatically speeds up the coarsening of the mound array, leading to coarsening exponents between 1/3 and 1/2. The underlying mechanism is the faster growth of larger mounds due to their lower evaporation rate.

Adsorption↗
PubMed1999

Analytic approach to the critical density in cellular automata for traffic flow.

The jamming transition in the stochastic traffic cellular automaton of Nagel and Schreckenberg [J. Phys. I 2, 2221 (1992)] is examined. We argue that most features of the transition found in the deterministic limit do not persist in the presence of noise, and suggest instead to define the transition to take place at that critical density rho(c) at which a large initial jam just fails to dissolve. We show that rho(c)=v(J)/(v(J)+v(F)), where v(F) is the velocity of noninteracting vehicles and v(J) is the speed of the dissolution wave moving into the jam. An approximate analytic calculation of v(J) in the framework of a simple renormalization scheme is presented, which explicitly displays the effect of the interaction between vehicles during the acceleration stage of the Nagel-Schreckenberg rules with maximum velocity v(max)>1. The analytic prediction is compared to numerical simulations. We find a remarkable correspondence between the analytic expression for v(J) and a phase diagram obtained numerically by Lübeck et al.

Journal Article↗
PubMed1997

[Interferon therapy and autoimmunity].

The treatment of viral hepatitis or malignomas with interferon (IFN) can increase the incidence of autoimmune disease. This paper reviews published case and study reports. The incidence of overt autoimmune diseases under IFN treatment is about 3%. Autoantibodies can be detected in 23% of the patients. Autoimmune thyroid diseases are the most frequent ones, but nearly all autoimmune diseases can occur. Beside benign and reversible courses chronic developments and lethal outcomes are possible. Actual concepts concerning the pathogenesis of IFN-associated autoimmunity include induction of MHC and other molecules as well as the modulation of lymphocyte functions. Clinical and paraclinical controls are necessary under treatment with IFN and during follow-up.

Anemia, Hemolytic, Autoimmune↗
PubMed1995

Induction of insulin antibodies and insulin allergy under alpha-interferon treatment of renal cell carcinoma in a patient with insulin-treated diabetes mellitus--a case report.

The induction of insulin antibodies and the development of an insulin allergy were observed in a male diabetic patient treated with insulin during alpha-IFN therapy of renal cell carcinoma. Diabetes and renal cell carcinoma were diagnosed at the same time. The patient was treated with biosynthetic human insulin and nephrectomy was performed. Four months later, antineoplastic chemotherapy was started (alpha-IFN, vinblastin). Six weeks after initiation of alpha-IFN injections, the patient reported signs of insulin allergy. Significant titers of insulin antibodies of both the IgG and IgE subclasses were found in the serum at that time and during follow-up, but not before the treatment with alpha-IFN. None of the other autoantibodies investigated were positive.

Adult↗
PubMed1993

Tolbutamide reduces the incidence of diabetes mellitus, but not insulitis, in the non-obese-diabetic mouse.

The functional state of beta cells may influence the rate of their destruction in Type 1 (insulin-dependent) diabetes mellitus. We examined the effect of diazoxide, which inhibits insulin secretion, or tolbutamide, which stimulates insulin secretion, upon the incidence of diabetes in the non-obese-diabetic (NOD) mouse. Female mice were treated from 3-30 weeks of age with diet containing diazoxide 250 mg.kg-1 or tolbutamide 125 mg.kg-1. The cumulative incidence of diabetes at 35 weeks was similar in the diazoxide (16 of 24) and control (18 of 24) groups, but reduced in the tolbutamide group (10 of 23, p < 0.04 vs control group). In a second experiment, treatment was started from 9 weeks of age, by which time insulitis is already present. The cumulative incidence of diabetes at 35 weeks was 16 of 24 in controls, 15 of 24 on diazoxide and 11 of 24 on tolbutamide (p = NS vs control). A third experiment compared the effect of treatment from 3 weeks with control diet or diet containing tolbutamide 125 mg.kg-1 or 500 mg.kg-1. Diabetes was reduced by tolbutamide treatment, with a cumulative incidence of 25 of 31 in controls, 18 of 30 on tolbutamide 125 mg.kg-1 (p < 0.04) and 14 of 32 on 500 mg.kg-1 (p < 0.002), although the difference between the two treatment groups failed to reach statistical significance. A fourth experiment showed that treatment from 3-12 weeks with diazoxide 1000 mg.kg-1 increased the extent of insulitis compared with controls and animals treated with tolbutamide 500 mg.kg-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗