Prospects for measuring the 229Th isomer energy using a metallic magnetic microcalorimeter.

The Thorium-229 isotope features a nuclear isomer state with an extremely low energy. The currently most accepted energy value, 7.8±0.5 eV, was obtained from an indirect measurement using a NASA x-ray microcalorimeter with an instrumental resolution 26 eV. We study, how state-of-the-art magnetic metallic microcalorimeters with an energy resolution down to a few eV can be used to measure the isomer energy. In particular, resolving the 29.18 keV doublet in the γ-spectrum following the α-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy. We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution.

Prognostic relevance of occult tumor cells in lymph nodes of colorectal carcinomas: an immunohistochemical study.

PURPOSE: Whereas lymph node metastases in colorectal carcinoma are an important prognostic factor, the prognostic relevance of occult tumor cells in lymph nodes is not elucidated at present. Therefore, our study intended to assess the rate of patients with occult tumor cells in histopathologically negative lymph nodes. Furthermore, we tried to evaluate an eventual influence of these occult tumor cells on patients' prognoses. METHODS: For examination, we used paraffin blocks of lymph nodes, tumor-negative by conventional histopathology, from 49 patients with colorectal carcinoma (Stage I-III) after a curative (R0) tumor resection in 1987. After preparation of tissue blocks using the serial sectioning technique, the specimens were stained with the alkaline phosphatase, antialkaline phosphatase method and two monoclonal antibodies (AE1/AE3 and Ber-EP4). RESULTS: In 13 of 49 patients (26.5 percent), we disclosed tumor cells, mostly located in subcapsular sinuses as single cells or in groups. There was a good correlation between the detection rate and N category, tumor stage, and grading. Moreover, 33 percent of patients in Stage I/II with occult tumor cells (N0+) developed a local relapse and/or distant metastases in contrast to 12 percent of patients without tumor cells (N0-). With a median follow-up of 84 months, we found no difference in disease-free survival between the tumor cell negative and positive groups in Stage I/II patients. CONCLUSION: The results show that occult tumor cells might increase the risk for development of a local tumor relapse and/or distant metastases but do not influence patients' prognoses at all.

[Bacteriuria--findings in diabetics]. / Bakteriurie--Befunde bei Diabetikern

The frequency of bacteriuria in 2.058 unselected diabetics obtained with the help of microscopic slides was 9.67%. Here women (n=1,325) with 13.5% have an essentially higher share of constant bacteriuria (number of germs more than 10(5)/ml) than men (n=733) with 2.4%. In very old men older than 75 years a clear increase to 14.6% could be proved. A relation between duration of diabetes and frequency of bacteriuria could not be ascertained. On the other hand there existed a dependence on the form of therapy of diabetes. A constant bacteriuria was present in dietetically led diabetics at 7.3%, in those persons treated with oral antidiabetics at 10.2%, in diabetics treated with insulin at 13.8%. The slide culture is clearly superior to the hitherto still used bacteriological and biochemical methods and is recommended particularly for screening tests.