Measurement of radon concentration in water using the portable radon survey meter.

A measurement method for measuring radon in water using the portable radon survey meter (RnSM) was developed. The container with propeller was used to stir the water samples and release radon from the water into the air in a sample box of the RnSM. In this method, the measurement of error would be <20 %, when the radon concentration in the mineral water was >20 Bq l(-1).

Thoron exhalation rates in areas of Japan.

Thoron exhalation rates were measured with a newly made portable instrument at 33 areas in 7 prefectures of Japan. Thoron exhalation rates ranged from 49 to 4890 mBq m(-2) s(-1). Radon exhalation rates were also measured in many of the areas at the same time and ranged from 2.1 to 11 mBq m(-2) s(-1). Thoron exhalation rates showed a rough correlation with radon exhalation rates. Both exhalation rates also showed a rough correlation with geological features.

Influence of soil environmental parameters on thoron exhalation rate.

Field measurements of thoron exhalation rates have been carried out using a ZnS(Ag) scintillation detector with an accumulation chamber. The influence of soil surface temperature and moisture saturation on the thoron exhalation rate was observed. When the variation of moisture saturation was small, the soil surface temperature appeared to induce a strong effect on the thoron exhalation rate. On the other hand, when the variation of moisture saturation was large, the influence of moisture saturation appeared to be larger than the soil surface temperature. The number of data ranged over 405, and the median was estimated to be 0.79 Bq m(-2) s(-1). Dependence of geology on the thoron exhalation rate from the soil surface was obviously found, and a nationwide distribution map of the thoron exhalation rate from the soil surface was drawn by using these data. It was generally high in the southwest region than in the northeast region.

The transport mechanisms of (222)Rn in soil at Tateishi as an anomaly spot in Japan.

The (222)Rn concentration profiles in soil have been measured at an anomaly spot in Tateishi, Japan. In winter, the concentrations were low and showed a negative gradient with depth, but in other seasons, the concentration had both positive and negative gradients with depth, and dramatically changed by time. On the assumption that there was ventilation in deep layers and with driving forces of wind and temperatures, these phenomena were successfully explained. This finding would contribute to a numerical model for (222)Rn transport in soil.

Metastatic hepatocellular carcinoma of the maxillary sinus: a rare autopsy case without lung metastasis and a review.

A rare case of metastatic hepatocellular carcinoma (HCC) of the maxillary sinus in a 67-year-old man is reported along with the findings at autopsy. A fine needle aspiration biopsy specimen revealed a characteristic tumour structure resembling primary HCC. At autopsy, metastatic lesions were recognized in the bilateral adrenals, spleen, sternum, vertebrae and lymph node at the lesser curvature of the stomach, but not in the lung, suggesting that the HCC had metastasized to the maxillary sinus via the plexus venous vertebralis and/or the azygos vein, or lymph duct. In our reviewed 29 cases of metastatic HCC in the oro-maxillofacial region, most patients were men in the 50- to 70-year age range. At least 11 cases did not have lung metastasis, and in 18, metastasis to the oro-maxillofacial region was the first sign of HCC. One should be aware of the possibility to encounter the oral lesion as first sign of metastatic HCC.

Instrument performance of a radon measuring system with the alpha-track detection technique.

An instrument performance test has been carried out for a radon measuring system made in Hungary. The system measures radon using the alpha-track detection technique. It consists of three parts: the passive detector, the etching unit and the evaluation unit. A CR-39 detector is used as the radiation detector. Alpha-track reading and data analysis are carried out after chemical etching. The following subjects were examined in the present study: (1) radon sensitivity, (2) performance of etching and evaluation processes and (3) thoron sensitivity. The radon sensitivity of 6.9 x 10(-4) mm(-2) (Bq m(-3) d)(-1) was acceptable for practical application. The thoron sensitivity was estimated to be as low as 3.3 x 10(-5) mm(-2) (Bq m(-3) d)(-1) from the experimental study.

Transitional cell papilloma in the fossa navicularis is positive for human papillomavirus.

Transitional cell papillomas rarely develop in the fossa navicularis of the anterior urethra. We observed such a case of transitional cell papilloma and detected human papillomavirus type 6 (HPV-6) DNA in this papilloma by polymerase chain reaction. To our knowledge this report is the first of HPV-infected transitional papilloma in the anterior urethra.

Infrared thermography of bullfrog skeletal muscle at rest and during an isometric tetanus.

Heat production in skeletal muscle has been studied with a thermopile consisting of several thermocouples in contact with muscle surface, and the experimental results have been interpreted on the assumption that heat is produced in a uniform manner. In the present study we have examined the temperature distribution of bullfrog sartorius muscle by the technique of infrared thermography, in which muscle temperatures at various regions can be measured and displayed as a thermogram on the monitor screen without thermal contact. It was found that in the muscle at rest and during an isometric tetanus, the temperature was not uniform, but differed from region to region. The amount of heat production during an isometric tetanus also differed from region to region, but the time course of heat production was nearly uniform in every region. By putting position markers on the muscle surface, it was possible to record muscle segment length changes together with temperature changes. It was found that during an isometric tetanus, the tibial region was stretched by the other regions, and the amount of heat produced was significantly greater in the other regions than in the tibial region. The application of infrared thermography in muscle energetics studies seems promising if the sensitivity of infrared detectors is improved.

Marked elevation of carcinoembryonic antigen and carbohydrate antigen 19-9 in the peripheral blood as an initial manifestation of meningeal carcinomatosis.

Marked elevation of tumor markers in the peripheral blood was initially a sole manifestation of meningeal carcinomatosis in a man with gastric carcinoma. In addition to extensive meningeal carcinomatosis, no metastatic lesions were found at autopsy other than microscopic infiltration into a tiny paraaortic lymph node. Elevation of these markers in the peripheral blood is best explained by meningeal carcinomatosis. When elevation of these markers is otherwise unexplainable, meningeal carcinomatosis should be considered as a diagnostic possibility even in the absence of neurological symptoms.

On some properties of 222Rn short-lived decay products in air.

Simultaneous measurements were made of such properties as the fraction of charged and uncharged atoms, the balance of radioactive equilibrium between 222Rn and its daughters, and the concentration of aerosol particles and their mean radii in tunnel air. It became clear that the behavior of 222Rn decay products in tunnel air could be expressed well by equations based on a simple model, taking the following into account: the attachment of free atoms to aerosol particles, the deposition of radioactive particles on the tunnel wall, emission of alpha recoils from aerosol particles and the surface of the tunnel wall, and radioactive decay. In addition, the effective attachment coefficient of an observed RaA-atom was found to agree well with that calculated. The results obtained should facilitate in the future estimation of the relation between 222Rn daughters and the lung dose to the population.