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Biomedical subjects

F Flesch

Publications and source records attributed to F Flesch.

At least 19 recordsLinked to original sources
PubMed2005

Nuclear fragmentation cross-sections of 400 A MeV 36Ar and 40Ar in collisions with light and heavy target nuclei.

We have measured fragmentation cross-sections of Ar projectile nuclei at beam energy of 400 A MeV using experimental set-ups with plastic nuclear track detectors and different targets. In this paper total charge changing cross-sections and elemental fragmentation cross-sections for the production of fragments with charges ZF > or = 7 in interactions with H, C, Al, Cu, Ag and Pb target nuclei are presented. The dependence of the cross-sections on the fragment charge number and target charge number are discussed. The experimental results are compared to predictions of semi empirical cross-section models.

Algorithms↗
PubMed2001

Energy spectra of HZE-particles inside the International Space Station.

To measure the energy spectra of low energy ions inside the International Space Station (ISS) we will expose three stacks of CR-39 plastic nuclear track detectors aligned to the three coordinate axes of the space station. The energies of cosmic ray nuclei at the stack surfaces can be determined by reconstructing the trajectories of ions stopping inside the detector material and by measuring their ranges. To measure only HZE (high charge Z and energy E) ions with charges of Z6 stopping in our experiment a special batch of CR-39 detectors with low sensitivity will be used. This detector material has been already tested by an exposure to carbon ions at the GSI accelerator in Darmstadt, Germany.

Carbon↗
PubMed2001

Repeated measurements of aldicarb in blood and urine in a case of nonfatal poisoning.

A nonfatal case of poisoning involving aldicarb, an extremely toxic carbamate pesticide, is presented. A 39-year-old female ingested an unknown amount of aldicarb, together with alprazolam and sertraline. On admission to ICU (T0), she displayed marked cholinergic symptoms and a deep coma. The patient was given pralidoxime and atropine. Her condition gradually improved on days 2 and 3 and she was discharged at T0+80 h. Aldicarb was assayed by high-performance liquid chromatography on 21 blood and 8 urine samples successively taken during hospitalization. At the same time, serum pseudocholinesterase activity was followed on 21 successive samples. Blood aldicarb level was 3.11 microg/mL at T0 and peaked at T0+3.5 h (3.22 microg/mL), then followed a two-slope decay with a terminal half-life of ca. 20 h. Aldicarb was detected in all urine samples (peak level: 6.95 microg/mL at T0+31.5 h) and was still present at the time of discharge. Serum pseudo-cholinesterase activity remained low (< or = 10% of normal) until the 30th hour then rapidly increased and returned to normal after the 60th hour. The patient's clinical picture closely followed blood aldicarb levels and serum pseudo-cholinesterase activities. To our knowledge, this is the first report of an aldicarb poisoning documented by repeated measurements of the drug in the intoxicated person.

Adult↗
PubMed1999

Energy spectrum of iron nuclei measured inside the MIR space craft using CR-39 track detectors.

We have exposed stacks of CR-39 plastic nuclear track detectors inside the MIR space craft during the EUROMIR95 space mission for almost 6 months. Over this long period a large number of tracks of high LET events was accumulated in the detector foils. The etching and measuring conditions for this experiment were optimized to detect tracks of stopping iron nuclei. We found 185 stopping iron nuclei inside the stack and identified their trajectories through the material of the experiment. Based on the energy-range relation the energy at the surface of the stack was determined. These particles allow the determination of the low energy part of the spectrum of iron nuclei behind shielding material inside the MIR station.

Cosmic Radiation↗
PubMed1998

[Acute poisoning during substitution therapy based on high-dosage buprenorphine. 29 clinical cases--20 fatal cases].

OBJECTIVES: Buprenorphine has been an important advance in care for drug abusers, but the toxic risk may be fatal. We report here two original series of buprenorphine poisoning in opiate abusers on substitution therapy. PATIENTS: The first series included 20 males and 9 females, aged 20-35 years (mean = 27.5) with non-fatal poisoning. The second series included 20 subjects (19 males, 1 female) aged 14-48 years (mean = 26.6) with a fatal outcome. All subjects were opiate addicts taking high-dosage sublingual buprenorphine formulation as substitution therapy. RESULTS: Blood concentrations of buprenorphine were found in all cases to remain at a low level (1.0-2.3 ng/ml, m = 1.4 ng/ml, and 1.1-29.0 ng/ml, m = 8.4 ng/ml in non-fatal and fatal cases respectively). Almost all cases involved concomitant intake of psychotropic medications, especially benzodiazepines (18 non-fatal and 17 fatal cases). DISCUSSION: These observations confirm previously reported data on the danger of buprenorphine-benzodiazepine combinations. Intravenous injection of crushed tablets also appears to be a risk factor (8 deaths and 10 non-fatal poisonings). This series highlights the need for improvement in the recently developed French program for substitution therapy with high-dosage buprenorphine in heroin addicts.

Administration, Sublingual↗
PubMed1996

Plasma and urine concentrations of atropine after the ingestion of cooked deadly nightshade berries.

BACKGROUND: Adult intoxications due to ingestion of deadly nightshade berries is uncommon. CASE REPORTS: Collective intoxication of eight persons occurred after accidental ingestion of ripened Atropa belladonna berries. Three of the four adults displayed delirious states with visual hallucinations; one patient fell into a coma and required mechanical ventilation. Four children and one adult exhibited mild peripheral anticholinergic symptoms. Kinetic data were obtained on the three hospitalized adults. DISCUSSION: The optimal intensive care for such patients is discussed.

Adult↗
PubMed1993

Kinetics of amatoxins in human poisoning: therapeutic implications.

The kinetics of alpha and beta amanitin were studied in 45 patients intoxicated with Amanita Phalloides. The amatoxins were analyzed by high performance liquid chromatography in plasma (43 cases), urine (35 cases), gastroduodenal fluid (12 cases), feces (12 cases) and tissues (4 cases). All patients had gastrointestinal symptoms and 43 developed an acute hepatitis. Two patients underwent successful liver transplantation. Eight patients, of whom three were children, died. The detection of amatoxins in the biological fluids was time dependent. The first sample was obtained at an average of 37.9 h post ingestion in the patients with positive results and at 70.6 h in the samples without detectable amatoxins. Plasma amatoxins were detected in 11 cases at 8 to 190 ng/mL for alpha and between 23.5 to 162 ng/mL for beta. In 23 cases amatoxins were detected in urine with a mean excretion per hour of 32.18 micrograms for alpha and 80.15 micrograms for beta. In 10 patients the total amounts eliminated in the feces (time variable) ranged between 8.4 and 152 micrograms for alpha amanitin and between 4.2 and 6270 micrograms for beta amanitin. In three of four cases amatoxins were still present in the liver and the kidney after day 5. Amatoxins were usually detectable in plasma before 36 h but were present in the urine until day 4. The rapid clearance indicates that enhanced elimination of amatoxins requires early treatment. Clearance of circulating amatoxins by day 4 spares the transplanted liver.

Adolescent↗
PubMed1993

When should dialysis be performed in lithium poisoning? A kinetic study in 14 cases of lithium poisoning.

Lithium kinetics were studied in 14 patients with lithium poisoning. Three patients were treated by hemodialysis. Serum lithium peak concentrations ranged between 1.4 and 9.6 mmol/L. The apparent mean serum half-life was 23.16 +/- 9 h, the mean total clearance was 26.5 +/- 13.3 mL/min and the mean renal clearance was 17.2 +/- 5.4 mL/min. The kinetic parameters were dependent on the duration of the study and on the type of the poisoning: acute, acute upon chronic or chronic. During the first 12 h after admission ten patients were in a distribution phase, three were in an elimination phase and one was in an absorption phase. The serum half-life during hemodialysis ranged from 3.6 to 5.7 h and hemodialysis clearance was 63.2 to 114.4 mL/min. The mean volume of distribution calculated in six cases was 0.63 +/- 0.09 L/kg. The evolution of the lithium pools showed a different kinetic pattern between the extra- and the intracellular pool which decreased more slowly. During hemodialysis the decrease of the extracellular pool was about twice that of the cellular pool. Among the factors which may modify lithium toxicity and kinetics, are the type of the poisoning, the presence of an underlying disease and renal impairment. No general and rigid indication for hemodialysis can be set, but the need for hemodialysis should be based on clinical and kinetic data determined during the 12 h following admission.

Adolescent↗
PubMed1985

Determination of alpha-amanitin and beta-amanitin in human biological fluids by high-performance liquid chromatography.

A high-performance liquid chromatographic assay of alpha-amanitin and beta-amanitin in human serum, urine, or stomach washings is described. Sample preparation involves a chemical step with deproteinization and organic solvent treatment, and a selective cleanup and concentration step on reversed-phase prepacked cartridges. Separations are performed on a reversed-phase analytical column under isocratic conditions with uv detection at 280 nm. The method allows the quantitation of alpha- and beta-amanitin separately with a detection limit of 10 ng/ml for both toxins.

Amanitins↗
PubMed1984

[Accidental ingestion of a battery].

A case of accidental battery ingestion by a three-year old boy is reported. The possible complications are local (i.e. necrosis of tissues by leakage of the alkaline electrolyte, by electrical injury or by impaction of the battery) and general (mercury poisoning). Large diameter batteries impacted in the oesophagus need prompt removal. When the battery is located in the stomach, two attitudes are discussed: some authors allow it to progress through the gastrointestinal tract spontaneously under radiological control, others recommend rapid removal by endoscopy or surgery in order to avoid the complications above described.

Accidents, Home↗