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Biomedical subjects

L Demling

Publications and source records attributed to L Demling.

At least 19 recordsLinked to original sources
PubMed1992

[Chaos research, fractals, fuzzy logic. From stereotypes to reality--consequences for medicine].

Both language and conventional mathematics aim to describe reality. Although language is more flexible, it is usually also inaccurate, while mathematics permits accurate presentations and clear prognoses. However, it is burdened by the fact that it is not everywhere applicable. Such chaotic structures as clouds, or lang-term weather forecasting, for example, cannot be expressed in terms of mathematics. Chaos researchers are attempting, in a non-linear world, to understand mathematically dynamic, apparently unordered systems. In this connection, the fractal dimension also appears--which can be employed in the area of diagnosis to define tumor contours. Fuzzy logic comes closer to reality by replacing the inflexible yes/no by a more or less option and by introducing linguistic nuances into machine-controlled processes. Chaos research and fuzzy logic teach us that there is no such thing as certainty of action or prognosis. In the world as it is, whoever claims to possess it is either naive or guilty of self-deception.

Artificial Intelligence↗
PubMed1991

[The laser in gastroenterology].

The use of lasers in gastroenterology is an enrichment of the non-invasive therapeutic methods. Prerequisite is their critical use which, in order to be successful, needs a minimum frequency and thus experience. In form of a strictly constructed survey the paper deals with the potential possibilities of laser application and with the alternative approaches being today at our disposal.

Endoscopes, Gastrointestinal↗
PubMed1989

[Spastic colon (irritable colon)].

Spastic colon is a pathological entity whose clinical symptoms are for the most part abdominal pain, constipation and episodes of diarrhea without loss of weight. In all probability, it is merely a particularly striking presentation of a GI tract that is irritable throughout its entirety. The pathophysiological basis is a disordered propulsive bowel motoricity. Etiologically, psychological factors in the presence of an appropriate genetic or acquired disposition are conceivable. Possible mediators are considered to be noradrenalin, beta-endorphin and the corticotropin-releasing factor. The diagnosis can be established with a high degree of probability on the basis of the characteristic clinical picture. A definitive diagnosis, however, requires the very careful exclusion of other possible diagnoses. Therapy includes talks with the patient, physical and dietetic measures and the use of drugs to ameliorate diarrhea or, in the case of prokinetic agents, to re-establish normal propulsive bowel activity.

Acetylcholine↗
PubMed1988

Urinary factors of kidney stone formation in patients with Crohn's disease.

An increased frequency of kidney stone formation is reported in patients with inflammatory bowel disease. In order to investigate its pathogenesis, the concentrations of factors known to enhance calcium oxalate stone formation (oxalate, calcium, uric acid) as well as of inhibitory factors for nephrolithiasis (magnesium, citrate) were determined in the urine of 86 patients with Crohn's disease and compared with those of 53 metabolically healthy controls. Six patients with Crohn's disease already had experienced calcium oxalate nephrolithiasis. Patients with Crohn's disease had significantly higher urinary oxalate and lower magnesium and citrate concentrations. Among all patients magnesium and citrate were significantly lower in those with a positive history of kidney stones. Our results demonstrate that the increased propensity for renal stone formation in patients with Crohn's disease is a result not only of increased urinary oxalate, but also of decreased urinary magnesium and citrate concentrations.

Adult↗
PubMed1988

Laserlithotripsy of common bile duct stones.

Endoscopic retrograde laser lithotripsy of common bile duct stones is a new technique which can be carried out through the endoscope without anaesthesia using ordinary endoscopic equipment. In the method described here a flashlamp pulsed Neodymium YAG laser (wave length 1064 nm) was used. Light energy was transmitted along a highly flexible quartz fibre with a diameter of 0.2 mm. This new technique was used in nine patients with concrements in the common bile duct, which could not be removed with the established endoscopic techniques. In eight of the nine the concrements (maximum diameter 4.7 x 3.1 cm) could be fragmented and in six the fragments could be extracted from the common bile duct. The total energy required was 80-300 J; complications were not observed.

Aged↗