Search PubMed⌕ Search

Biomedical subjects

J Evers

Publications and source records attributed to J Evers.

At least 19 recordsLinked to original sources
PubMed2006

Quantum interference enforced by time-energy complementarity.

The interplay of the concepts of complementarity and interference in the time-energy domain are studied. In particular, we theoretically investigate the fluorescence light from a J = 1/2 to J= 1/2 transition that is driven by a monochromatic laser field. We find that the spectrum of resonance fluorescence exhibits a signature of vacuum-mediated interference effects, whereas the total intensity is not affected by interference. We demonstrate that this result is a consequence of the principle of complementarity, applied to time and energy. Since the considered level scheme can be found, e.g., in (198)Hg(+) ions, our model system turns out to be an ideal candidate to provide evidence for as yet experimentally unconfirmed vacuum-induced atomic coherences.

Journal Article↗
PubMed2003

[Clinical course and therapy of Langerhans cell histiocytosis in children and adults].

The Langerhans cell histiocytosis is a rare disease with a clear preference of infancy and an incidence of 0.2 to 1.0/100,000 children occurring worldwide. In 60 to 70% of the cases the first manifestation is before the second year of age. The disease prefers the male sex in a male to female relation of 2:1. Occurrence in adult age is very rare. Up to 10% of the cases are congenital. Both the etiology and the pathogenesis of the disease are unknown. The clinical presentation is extremely variable and covers a wide spectrum from localized involvement with a favorable prognosis to disseminated, malignant and foudroyant course. We report on ten patients, six infants and children and four adolescents and adults. We point out the very variable morphologic manifestations, the different disease course and the therapeutic options.

Adult↗
PubMed1999

A retrospective follow-up study on intracytoplasmic sperm injection.

PURPOSE: Genetic aspects of male subfertility and the novelty of intracytoplasmic sperm injection (ICSI) as a new technique can influence the development of zygotes and children born after ICSI. Therefore, we evaluated the outcome of ICSI compared to in vitro fertilization (IVF). METHODS: Data from medical records of 233 total pregnancies and the follow-up of 132 children born after IVF and 120 after ICSI were retrospectively analyzed. RESULTS: No differences were found between ICSI and IVF for early embryonic development and obstetric outcome. In both groups the rate of women undergoing prenatal chromosomal diagnosis was low, 30.0%. The congenital malformation rate was 3.0% after IVF and 1.7% after ICSI, which was not significantly different. Follow-up on development of children born after IVF and ICSI also showed no significant differences. CONCLUSIONS: Our results indicate that at this moment ICSI is a safe procedure. However, a consistent prospective follow-up is still mandatory to exclude possible risks.

Adult↗
PubMed1997

Elevated serum concentrations of soluble selectin and immunoglobulin type adhesion molecules in patients with inflammatory bowel disease.

Adhesion molecules mediate the extravasation of leukocytes and their accumulation in inflamed tissues. In the present study, serum concentrations of the selectin (sP- and sE-selectin) and immunoglobulin supergene family (sICAM-1 and sVCAM-1) of adhesion molecules were measured in 93 patients with inflammatory bowel disease (Crohn's disease, n = 65; ulcerative colitis, n = 28) and 58 age-matched normal controls. sP-selectin serum concentrations (mean +/- SEM ng/ml) of patients with Crohn's disease (399 +/- 33 ng/ml) and ulcerative colitis (385 +/- 42 ng/ml) were increased (P = 0.0067 and P = 0.0193, respectively) compared to controls (251 +/- 33 ng/ml). In contrast, E-selectin serum levels of patients with Crohn's disease (58 +/- 5 ng/ml) and ulcerative colitis (64 +/- 12 ng/ml) were not significantly higher than those of controls (53 +/- 5 ng/ml). sICAM-1 serum concentrations of patients with Crohn's disease (420 +/- 19 ng/ml) and those with ulcerative colitis (375 +/- 40 ng/ml) were elevated (P = 0.0001 and P = 0.0473, respectively) compared to controls (297 +/- 8 ng/ml). Further, sVCAM-1 levels of patients with Crohn's disease (664 +/- 43 ng/ml) and ulcerative colitis (963 +/- 162 ng/ml) were increased (P = 0.0222 and P = 0.0121, respectively) compared to controls (510 +/- 31 ng/ml). With few exceptions, serum levels of soluble adhesion molecules were not significantly correlated to disease activity indices or disease localization. Elevated circulating selectin and immunoglobulin supergene type adhesion molecules may compete with membrane-bound forms for their cognate ligands and thereby limit the rolling and stable adhesion of leukocytes.

Adolescent↗
PubMed1997

Blood-brain barrier water permeability and brain osmolyte content during edema development.

OBJECTIVE: To determine mechanisms that limit changes in brain water content during acute edema development. METHODS: A controlled, laboratory investigation of the physiologic and biochemical correlates of osmotic edema was performed in rats. Hypoosmotic hyponatremia was induced by intraperitoneal injection of distilled water. Serum osmolality and electrolytes and regional blood-brain barrier water permeability. Surface area (P.S) product, osmolyte contents, and capillary size were determined during 120 minutes of hypoosmotic brain edema development. Cerebral water content predicted from these data using a mathematical model of brain water movements was compared with measured changes in brain water content. RESULTS: Fifteen minutes after distilled water injection, mean +/- SEM blood serum osmolality and sodium concentration decreased from 291 +/- 3 mOsm and 131 +/- 13 mmol/L to 267 +/- 3 mOsm and 102 +/- 9 mmol/L, respectively. Specific gravity of cerebral gray matter, cerebral white matter, and basal ganglia decreased throughout the hypoosmotic exposure period and, for gray and white matter, correlated with blood serum osmolality and sodium plus potassium content. Glutamate, but not glutamine, glycine, or taurine, decreased 120 minutes after water injection. The regional water P.S product decreased by 40% to 60% within 60 minutes of the water injection, while capillary diameters in gray and white matter were unchanged. Brain water movements calculated from the mathematical model correctly predicted actual brain water content only if the hydraulic conductivity of the blood-brain barrier was allowed to vary in proportion to the measured P.S product and the measured loss of brain osmolytes was incorporated into the formulation. CONCLUSIONS: During the first hours of hypoosmotic hyponatremia, changes in brain volume are limited by increased resistance to osmotic flux of water into the brain and reduction in the brain content of inorganic and, to a smaller degree, organic osmolytes.

Analysis of Variance↗
PubMed1996

Reduced serum levels of a soluble form of the human adhesion receptor CD58 (LFA-3) in patients with inflammatory bowel disease.

The activation of monocytes, neutrophils, and B cells by T-lymphocytes appears to play a pivotal role in the pathophysiology of inflammatory bowel disease. The pan T cell marker CD2 and its ligand CD58 mediate these immune function. We asked whether serum levels of a soluble form of CD58 is altered in patients with inflammatory bowel disease. Soluble CD58 was measured in sera from 41 patients with Crohn's disease, 19 patients with ulcerative colitis, and 24 normal controls. Soluble CD58 levels were significantly decreased in sera from patients with ulcerative colitis and even more with Crohn's disease when compared to controls (p = 0.025 and p < 0.0001, respectively). Reduction of soluble CD58 serum levels correlated significantly with various humoral (e.g. erythrocyte sedimentation rate: r = -0.48, p = 0.0002) and clinical parameters of disease activity (e.g. CDAI: r = -0.44, p = 0.005). In conclusion, serum levels of soluble CD58 are reduced in patients with inflammatory bowel disease. Since soluble CD58 can block the CD2/CD58 interaction further studies have to show whether the reduction of soluble CD58 in patients with inflammatory bowel disease contributes to T cell adhesiveness in the mucosa.

Adolescent↗
PubMed1995

Influence of renal function on the steady-state pharmacokinetics of the antiarrhythmic propafenone and its phase I and phase II metabolites.

The aim of this study was to investigate the disposition of propafenone and its Phase I and II metabolites in relation to kidney function under steady-state conditions. The mechanism of the renal handling of propafenone glucuronides (filtration, secretion) was also examined. Racemic (R/S) propafenone was administered to 7 young volunteers, to 5 older patients with a normal glomerular filtration rate and to 4 patients with chronic renal failure. No difference was found in the plasma concentrations of propafenone and 5-hydroxypropafenone between the three groups. The propafenone glucuronide (PPFG) concentration was elevated in the older compared to the younger subjects (S-PPFG: 544 vs. 222 nmol.ml-1.mol-1; R-PPFG: 576 vs. 304 nmol.ml-1.mol-1). Although Glomerular filtration rate did not differ, the renal clearance of propafenone glucuronides was reduced in the former group, which could be attributed to their impaired renal secretion. A dramatic increase in propafenone glucuronide concentration was observed in the patients with renal failure (S-PPFG: 2783 nmol.ml-1.mol-1; R-PPFG: 7340 nmol.ml-1.mol-1). In summary, the disposition of propafenone and of its active metabolite 5-hydroxypropafenone was not affected by kidney dysfunction, indicating that no dose adjustment is necessary in patients with renal failure. The accumulation of drug glucuronides in older patients with apparently normal kidney function should be taken into account as a possible factor modifying drug therapy.

Aged↗
PubMed1995

Fatal lorcainide poisoning.

A case of lorcainide poisoning with fatal outcome is reported. A young girl of 15 ingested, without high lethality of intent, 2500 mg lorcainide, an antiarrhythmic agent. Bradycardia, shock, coma, and cerebral convulsions rapidly occurred. Despite immediate resuscitative measures with high doses of catecholamines and hypertonic sodium bicarbonate the patient died three hours later. The course of lorcainide poisoning was similar to that of other class Ic antiarrhythmic agents.

Adolescent↗
PubMed1994

Unpredictability of flecainide plasma concentrations in patients with renal failure: relationship to side effects and sudden death?

We report a retrospective evaluation of plasma concentrations of flecainide obtained from five dialysis patients during chronic oral treatment. A more than sevenfold variation in the dose/concentration relationship was observed. Plasma concentrations of flecainide above 1,200 ng/ml appeared to be associated with serious side effects and in one case with sudden death. Therefore, flecainide should be used with extreme caution in patients with impaired renal function. Frequent therapeutic drug monitoring should be mandatory.

Aged↗
PubMed1993

Elimination of cefmenoxime during continuous haemofiltration.

The elimination of cefmenoxime after single and repeated i.v. dosing was studied in 12 patients with severe renal failure and sepsis during continuous haemofiltration. More than 30% of the drug was found in the filtrate. The sieving coefficient (S) was 0.54. Vss% was unchanged 0.31 l.kg-1 in comparison with patients with normal renal function, whereas the mean t1/2ss was prolonged to about 16 h, and total clearance was reduced 20.8 ml.min-1.1.73 m-2. Once daily administration of 1 g cefmenoxime is suggested as the appropriate dose under such circumstances.

Adult↗