Integrated measurements of short-lived 222Rn progeny by rotating filters

The dependence of the risk from inhalation of radon progeny on their disequilibrium suggests that the measurements of the time-integrated concentrations of each of the short-lived radon progeny are necessary for complete risk estimations. This paper presents a method that, in principle, allows the determination of the integrated specific volume activities in air of each of the radionuclides 218Po, 214Pb, 214Bi, 212Pb, and 212Bi. The method employs thermoluminescence detectors positioned around uniformly rotating filters. Two prototypes that are suitable for practical applications are described and mathematical expressions for data processing are given. Experiments with these "rotating filter dosimeters" were conducted in atmospheres radiologically dominated by 222Rn progeny. The comparison between the results obtained by the proposed method and those given by simultaneously conducted series of instantaneous grab-sampling measurements support the conclusion that the method works for 222Rn progeny. The method can be experimentally extended for 220Rn progeny as well as for unattached fractions.     

Loss of heterozygosity on the long arm of human chromosome 7 in sporadic renal cell carcinomas

Cytogenetic and molecular analysis of DNA sequences with highly polymorphic microsatellite markers have implicated allele loss in several chromosomal regions including 3p, 6p, 6q, 8p, 9p, 9q, 11p and 14q in the pathogenesis of sporadic renal cell carcinomas (RCCs). Deletions involving the long arm of chromosome 7 have not been described in RCCs although they have been seen in several other tumor types. However, there have been no detailed analysis of loss of heterozygosity (LOH) of 7q sequences in sporadic RCCs. We therefore studied LOH for DNA sequences on 7q with 10 highly polymorphic markers in 92 matched normal/tumor samples representing sporadic RCCs including papillary, nonpapillary, and oncocytomas in order to determine whether allelic loss could be detected in a tumor type with no visible 7q rearrangements at the cytogenetic level. We found chromosome 7q allele loss in 59 of 92 cases (64%) involving one, two, or more microsatellite markers. The most common allele loss included loci D7S522 (24%) and D7S649 (30%) at 7q31.1-31.2, a region that contains one of the common fragile sites, FRA7G. By comparative multiplex PCR analysis, we detected a homozygous deletion of one marker in the 7q 31.1-31.2 region in one tumor, RC21. These results support the idea that a tumor suppressor gene in 7q31 is involved in the pathogenesis of sporadic renal cell carcinomas.     

Preoperative assessment and prediction of postoperative results in an artificial arterial network using computer simulation

A computer model has been developed that can be used to describe the human arterial system mathematically. It simulates the complex relationship of morphology and hydraulics in the vessel network. After entering patient data into a standard vessel model, the mean flow velocity, the flow direction, and the blood pressure at each specified point of the flow network can be calculated. The vessel picture can be altered and modified with the help of a graphic editor. Localized or diffuse stenoses, bypasses with simple or multiple anastomoses, end-to-end anastomoses, end-to-side anastomoses, etc., can be studied in terms of the hydraulic effects on the local situation or on the entire vessel system. Experimental results of ultrasonic mean flow data in vessel systems of leg and cerebral arteries of patients are compared with calculated values. The predicted and measured flow velocities show a mean difference of about 10% indicating that such a computer model may be successfully used in the optimal planning of bypass operations.     

The importance of steroid receptors for the prognosis and hormone treatment of breast cancer patients: a retrospective study in Southeastern Netherlands

OBJECTIVE: To assess the effect of oestrogen (ER) and progesterone (PgR) receptors on the prognosis of patients with operable breast cancer and the decision to treat these patients with adjuvant tamoxifen. DESIGN: Retrospective. SETTING: Eight community hospitals in the Southeast Netherlands. METHOD: Using the registry of the Comprehensive Cancer Centre South, 2862 breast cancer patients were identified with stage I, II or IIIA tumours, treated during the period 1984-1992. RESULTS: ER and PgR status were known for 2393 (84%) and 1761 (62%) patients respectively. From 1991, over 80% of the postmenopausal, lymph node positive patients had received tamoxifen, irrespective of the steroid receptor status. Of all lymph node negative patients fewer than 3% received adjuvant systemic treatment. Among the lymph node negative patients the steroid receptor status was not a significant predictor of survival. Among the lymph node positive patients whose tumours were both ER-negative and PgR-negative, a 2.8-fold increased risk of death was found during the first four years after primary treatment. The risk of death was not increased if only the ER or only the PgR status was negative. CONCLUSION: This study shows that ER and PgR receptors are significant prognostic factors for survival in breast cancer patients with involved axillary lymph nodes. The prognostic effect appeared to be restricted to the first four years after primary treatment. Selection of patients for endocrine treatment should be based on the steroid receptor status, considering the importance of the steroid receptors for predicting the response to endocrine treatment.     

Behavioral treatment of the speaking stomach syndrome

The speaking stomach syndrome consists of persisting gurgling sounds in the gastric region, synchronous with breathing. A characteristic finding in patients suffering from this syndrome is an abnormal pattern of respiration, with extreme activity of the abdominal muscles and active involvement of the diaphragm. To teach the patient a different way of breathing using combined thoracic/abdominal respiration, with no, or hardly any, active contraction of the abdominal muscles, is an essential feature of treatment. This is accomplished in three steps. The treatment was successful in the three cases. Problems encountered in therapy are discussed.