Overexpression of the EGF receptor and p53 mutations are mutually exclusive in the evolution of primary and secondary glioblastomas.

Glioblastoma multiforme, the most malignant human brain tumor, may develop de novo (primary glioblastoma) or through progression from low-grade or anaplastic astrocytoma (secondary glioblastoma). We present further evidence that primary and secondary glioblastomas constitute distinct disease entities which develop through the acquisition of different genetic alterations. We analyzed p53 mutations, p53 protein accumulation and epidermal growth factor receptor (EGFR) overexpression in 49 biopsies classified as primary or secondary glioblastoma according to clinical and histopathologic criteria. Patients with primary glioblastoma were selected on the basis of a clinical history of less than 3 months and histopathologic features of glioblastoma at the first biopsy (19 cases; mean age, 55 years). The diagnosis of secondary glioblastomas required at least two biopsies and clinical as well as histologic evidence of progression from low grade or anaplastic astrocytoma (30 cases; mean age, 39 years). DNA sequence analysis showed that p53 mutations were rare in primary glioblastomas (11%) while secondary glioblastomas had a high incidence of p53 mutations (67%), of which 90% were already present in the first biopsy. The incidence of p53 protein accumulation (nuclear immunoreactivity to PAb 1801) was also lower in primary (37%) than in secondary glioblastomas (97%). In contrast, immunoreactivity for the EGF receptor prevailed in primary glioblastomas (63%) but was rare in secondary glioblastomas (10%). Only one out of 49 glioblastomas showed EGFR overexpression and a p53 mutation. These data indicate that overexpression of the EGF receptor and mutations of the p53 tumor suppressor gene are mutually exclusive events defining two different genetic pathways in the evolution of glioblastoma as the common phenotypic endpoint.

High risk ratio on mortality and characteristics of malignancies in dialysis patients.

A questionnaire study was done in order to clarify the risk ratios on the mortality of malignancy and the characteristics of malignancies in dialysis patients. The risk ratios were 4.2 times in males and 7.5 times in females greater than those among the age adjusted general population respectively. The average interval from the first dialysis to the clinical onset of malignant disease was 12 months. About a half of the patients died within 3 months. Frequencies of death in colon cancer, especially rectum, uterus and liver were higher in dialysis patients. Dialysis patients died of malignancies belonged to the older group of the dialysis patient population, however they were younger comparing with those died of malignancies in the general population.

Dialyzing room disinfection with ultra-violet irradiation.

Infections represent a major problem in dialysis treatment, thus the dialyzing room should be kept abacterial as possible. We have installed 15-watt ultra-violet (U-V.) lamps for every 13.5 m2 on the ceiling for the purpose of the room disinfection and used them for 16 hours nightly after working hours. Bacteria were killed with over 10 hours irradiation even at the areas of low U-V. intensity where the irradiation may not be direct. This unexpected effectiveness might be from the influence of reflected rays and 03 produced. When half the lamps were turned on, the bacteriocidal effect was not sufficient in some areas. Any living organism with nucleic acids must be inactivated by this treatment, for the baceteriocidal effect is due to the nucleic acids injury. Furthermore, safety, readiness after the treatment, easy application and the negligible costs would make this method more advantageous to the other methods in room disinfection.