Tacit knowledge--an epistemological framework and implications for research in doctors information needs.

We propose an epistemological framework of medical knowledge which might guide research and attempts in fulfilling doctors information needs. Tacit knowledge is influencing information needs and medical work but it is epistemological unresolved whether it is possible to articulate all this tacit knowledge and thus making it accessible to decision support system programming. Tacit knowledge might explain the difficulties in building successful decision support systems and should be taken into account in research.

Gastric intrinsic factor production and vitamin B12 absorption after oesophageal resection using stomach as substitute.

OBJECTIVE: To investigate whether the use of the stomach as a substitute after oesophageal resections causes disturbances in vitamin B12 absorption due to deficient intrinsic factor (IF) production. MATERIAL AND METHODS: Eleven patients operated upon with oesophageal resection a.m. Ivor Lewis, for malignant (10) or benign (1) conditions of the oesophagus were examined with a postoperative dual isotope technique 11-41 months (mean 25 months) after operation. RESULTS: In two patients the test showed abnormally low absorption of vitamin B12. One of these probably due to incomplete urine collection during the test period. However, no patient showed deficient intrinsic factor production with absorption ratios between vitamin B12 +/- IF of 0.87-1.14 (reference interval: 0.70-1.20). CONCLUSION: Deficiency of intrinsic factor is neither an obligatory nor a common occurrence after oesophageal resection with gastric substitute. However, vitamin B12 absorption may be low due to other factors, and should be looked for in all patients surviving more than a couple of months postoperatively.

Steatorrhea cannot be excluded where there is a fecal weight below 0.200 kg per day and a high fecal consistency.

We surveyed one year's results of fecal fat (feces alifatic carboxylates) analyses, which are used in the diagnosis of malabsorption (steatorrhea), by calculating the relationship between fecal fat, fecal weight (fecal mass excretion rate) and fecal consistency (in terms of the volume of water added to a fecal mass so that it can be aspirated into a pipette). N=203 analyses from 191 patients. Reference range for fecal fat: 0-24 mmol/24 h. Linear regression and correlation analyses showed an inverse correlation between fecal weight and fecal consistency and a positive correlation between fecal weight and fecal fat. Our results confirmed earlier findings in the literature that approximately 17% of steatorrheic specimens would be missed if a fecal weight below 0.200 kg/24 h was used to exclude further fecal fat analysis. Fewer steatorrheic specimens would be missed if a lower fecal weight were used: 7% at 0.180 kg/24 h, 3% at 0.140 kg/24 h and 0% at 0.120 kg/24 h. There was no correlation between fecal fat and consistency. The mean volume of added water was not different in normal and steatorrheic feces. The fat content could be predicted as normal only in the seven specimens (3.5% (1-7%)) that had more than 3.8 L/kg water added. Thus, an abnormal fecal fat content cannot reliably be excluded, in a routine setting, on the basis of a fecal weight below 0.200 kg/24 h and a high fecal consistency.

[Immunological techniques in unexplained thrombocytopenia. A case of specific diagnosis of post-transfusion purpura]. / Immunologiske teknikker ved uafklaret trombocytopeni. Tilfoelde af posttransfusionspurpura specifikt diagnosticeret.

A case of post-transfusion purpura is presented. The diagnosis is based on two new techniques with immunological aspects: 1) Monoclonal Antibody Immobilization of Platelet Antigen assay (MAIPA-assay) and 2) Polymerase Chain Reaction assay (PCR-assay). MESH: Thrombocytopenia. Post-transfusion purpura. Monoclonal Antibody Immobilization of Platelet Antigen assay (MAIPA-assay). Polymerase Chain Reaction assay (PCR-assay).