Evidence by cellular mosaicism for monoclonal metastasis of spontaneous mouse mammary tumors

Female (SHN X C3H/He)F1 mice carrying spontaneous mammary tumors with cellular mosaicism with respect to isozymes of phosphoglycerate kinase (PGK) showed a high incidence of lung metastases. On resection of successively appearing mammary tumors, mice survived a maximum of 8 tumors. In these mice with multiple primary mammary tumors and multiple metastases, not only each individual metastasis but also all the metastases in the same lung had the same pattern of PGK isozymes and the same histologic type in the PGK-mosaic background of the host, indicating the monoclonal origin of these metastases. In several cases, this single pattern of metastatic colonies coincided with that of only one of several primary tumors, indicating that this tumor had metastasized. In these cases, these tumors were not necessarily the earliest of the primary tumors, and they were not located in any particular site.     

Craniopharyngioma presenting a symptom of pituitary apoplexy and hyponatremia: a case report

We report a case of a 70-year-old woman admitted to our hospital with sudden headache, drowsiness and hyponatremia. MRI on admission showed an intrasellar mass with suprasellar extension. Serum examination revealed decreased sodium and hypopituitarism, but they were normalized gradually by compensation using hydrocortisone, thyroid hormone and salt. Afterwards, masked diabetes insipidus appeared and required aqueous pitressin for the control of urine volume. A removal operation was performed uneventfully using the transsphenoidal approach and histological examination confirmed squamous-papillary type craniopharyngioma. Intratumoral hemorrhage of the craniopharyngioma is extremely rare. These cases tend to occur after over 15 years of maturation and the squamous-papillary type tend to bleed more than the adamantinomatous type. However, it is very difficult to make a differential diagnosis between craniopharyngioma with intratumoral hemorrhage and pituitary apoplexy, judging only by symptoms or interventional radiology. The definite mechanism of hyponatremia associated with a parasellar lesion is still obscure, but compression to the anterior hypothalamus or pituitary gland by an enlargement of the parasellar tumor is generally hypothesized.     

Radiation cancer risk at different dose rates: new dose-rate effectiveness factors derived from revised A-bomb radiation dosimetry data and non-tumor doses

The dose rate of atomic bomb (A-bomb) radiation to the survivors has still remained unclear, although the dose–response data of A-bomb cancers has been taken as a standard in estimating the cancer risk of radiation and the dose and dose-rate effectiveness factor (DDREF). Since the applicability of the currently used DDREF of 2 derived from A-bomb data is limited in a narrow dose-rate range, 0.25-75 Gy/min as estimated from analysis of DS86 dosimetry data in the present study, a non-tumor dose (D_nt) was applied in an attempt to gain a more universal dose-rate effectiveness factor (DREF), where D_nt is an empirical parameter defined as the highest dose at which no statistically significant tumor increase is observed above the control level and its magnitude depends on the dose rate. The new DREF values were expressed as a function of the dose rate at four exposure categories, i.e. partial body low LET, whole body low linear energy transfer (LET), partial body high LET and whole body high LET and provided a value of 14 for environmental level radiation at a dose rate of 10⁻⁹ Gy/min for whole body low LET.     

Cytological evidence for single-cell origin of tumors induced with 3-methylcholanthrene in female mice carrying Cattanach's translocation

Chromosome studies were carried out on 12 tumors induced by subcutaneous injection of 0.005-0.5 mg of 3-methylcholanthrene in female mice carrying Cattanach's X-autosome translocation. Using the asynchronously replicating (hence genetically inactive) X chromosome as a marker, we obtained evidence showing that most or all of these tumors were monoclonal in origin. A single case, in which cell fusion occurred early in tumorigenesis, demonstrated that simultaneous expression of two different X chromosomes is not always incompatible with monoclonality.     

Diagnostic accuracy of a volume-rendered computed tomography movie and other computed tomography-based imaging methods in assessment of renal vascular anatomy for laparoscopic donor nephrectomy

To evaluate the diagnostic accuracy of computed tomography (CT)-based imaging methods for assessing renal vascular anatomy, imaging studies, including standard axial CT, three-dimensional volume-rendered CT (3DVR-CT), and a 3DVR-CT movie, were performed on 30 patients who underwent laparoscopic donor nephrectomy (10 right side, 20 left side) for predicting the location of the renal arteries and renal, adrenal, gonadal, and lumbar veins. These findings were compared with videos obtained during the operation. Two of 37 renal arteries observed intraoperatively were missed by standard axial CT and 3DVR-CT, whereas all arteries were identified by the 3DVR-CT movie. Two of 36 renal veins were missed by standard axial CT and 3DVR-CT, whereas 1 was missed by the 3DVR-CT movie. In 20 left renal hilar anatomical structures, 20 adrenal, 20 gonadal, and 22 lumbar veins were observed during the operation. Preoperatively, the standard axial CT, 3DVR-CT, and 3DVR-CT movie detected 11, 19, and 20 adrenal veins; 13, 14, and 19 gonadal veins; and 6, 11, and 15 lumbar veins, respectively. Overall, of 135 renal vascular structures, the standard axial CT, 3DVR-CT, and 3DVR-CT movie accurately detected 99 (73.3%), 113 (83.7%), and 126 (93.3%) vessels, respectively, which indicated that the 3DVR-CT movie demonstrated a significantly higher detection rate than other CT-based imaging methods (P < 0.05). The 3DVR-CT movie accurately provides essential information about the renal vascular anatomy before laparoscopic donor nephrectomy.     

Evidence for involvement of mast cells in tumor suppression in mice

Mast cell-deficient W/Wv mice had an increased tumor incidence after subcutaneous treatment with 3-methylcholanthrene, compared with that in normal congenic mice treated in the same way. This increased tumor incidence was suppressed to the normal level when the carcinogen was given after the mast cell deficiency had been overcome by transplantation of bone marrow cells from normal congenic mice. The W/Wv mice, however, were not defective in natural killer and T-cell-mediated cytotoxic activities. These results support the hypothesis that mast cells are involved in tumor suppression.