Two cases of postoperative enterocolitis due to methicillin-resistant Staphylococcus aureus (MRSA) after gastrectomy were experienced. Case 1: A 59-year-old male underwent subtotal gastrectomy for advanced gastric cancer. Diffuse peritonitis progressed after the first operation, so reoperation for drainage was required. Two days after the second operation, a profuse watery diarrhea developed. Case 2: A 46-year-old male underwent total gastrectomy for early gastric cancer. On the fourth postoperative day, frequent vomiting and cholera-like diarrhea started, followed by profound shock several hours later. Both cases were treated successfully by the administration of vancomycin.
Stool cultures of both cases revealed MRSA and it had the same minimal inhibitory concentration, coagulase type and enterotoxin type, so that nosocomial infection was indicated.
Despite the apparent demand for a consultation system, only a few expert systems have been developed for laboratory medicine. Some studies on the diagnostic precision of such systems have been reported, but the efficiency of their knowledge bases has not yet been investigated. An expert system, named BLOOD, for data analysis in a hematology laboratory, which is written in C-Prolog and runs on VAX-station, has already been reported to have excellent diagnostic reliability and ability to cope with the fuzziness involved in clinical diagnostic procedures. A quantitative examination of the knowledge base of BLOOD using real laboratory data from 58 patients diagnosed as having iron deficiency anemia clearly revealed the verbosity of the knowledge base, and proved that it was effective for obtaining a group of essential diagnostic rules.
Cytogenetic studies were performed on six cell lines derived from three patients suffering from malignant melanomas. The modal chromosome numbers were in the hypotriploid to hypertetraploid ranges and both the numerical and structural aberrations of chromosomes were found. Aberrations were most frequently observed in chromosomes 1, 6 and 7. Deletion of 1q was consistently present in all cell lines, while loss of 6q was observed in two cell lines of case l. Translocations t (Y; 6) and t (6; ?) occurred in one cell line from case 3. An increased number of copies of chromosome 7 was a characteristic feature of the cell lines from case 2. Since positive correlation between the expression of EGF receptors and an increased dosage of chromosome 7 has been reported for malignant melanomas and the gene for EGFR has been mapped to band 7pl2-p13, this phenomenon might be of importance for the proliferation of malignant melanoma. The findings of the present study are generally in agreement with the data previously published in the literature, indicating the existence of specific non-random chromosome lesions during melanoma development.