Upgrading of shielding for rare decay search in CANDLES

In the CANDLES experiment aiming to search for the very rare neutrino-less double beta decays (0νββ) using 48Ca, we introduced a new shielding system for high energy γ-rays from neutron captures in massive materials near the detector, in addition to the background reduction for 232Th decays in the 0νββ target of CaF2 crystals. The method of background reduction and the performance of newly installed shielding system are described

Graft-versus-Leukemia Effect of Nonmyeloablative Stem Cell Transplantation

Nonmyeloablative stem cell transplantation (NST) is increasingly used with beneficial effects because it can be applied to older patients with hematological malignancies and those with various complications who are not suitable for conventional myeloablative stem cell transplantation (CST). Various conditioning regimens differ in their myeloablative and immunosuppressive intensity. Regardless of the type of conditioning regimen, graft-versus- host disease (GVHD) in NST occurs almost equally in CST, although a slightly delayed development of acute GVHD is observed in NST. Although graft-versus-hematological malignancy effects (i.e., graft-versus-leukemia effect, graft-versus-lymphoma effect, and graft-versus-myeloma effect) also occur in NST, completely eradicating residual malignant cells through allogeneic immune responses is insufficient in cases with rapidly growing disease or uncontrolled progressive disease. Donor lymphocyte infusion (DLI) is sometimes combined to support engraftment and to augment the graft-versus-hematological malignancy effect, such as the graft-versus-leukemia effect. DLI is especially effective for controlling relapse in the chronic phase of chronic myelogenous leukemia, but not so effective against other diseases. Indeed, NST is a beneficial procedure for expanding the opportunity of allogeneic hematopoietic stem cell transplantation to many patients with hematological malignancies. However, a more sophisticated improvement in separating graft-versus-hematological malignancy effects from GVHD is required in the future

ANEURYSMAL RUPTURE DUE TO CEREBRAL ANGIOGRAPHY SUBSEQUENT TO SUBARACHNOID HEMORRHAGE

A report is made of a case of rupture of intracranial aneurysm by angiography which was done four hours after the subarachnoid hemorrhage. This is a twenty-eighth reported case of the ruptured aneurysm by angiography. The criteria of this complication are presented. The cause and mechanism of this complication (especially vasospasm, change of intraarterial pressure and peeling out of the thrombus) is discussed. Clinical factors of this complication are shown by summarizing previous reports. Cerebral angiography within a few hours after subarachnoid hemorrhage is very dangerous although it is said that angiography should be done as early as possible

EPIDERMOID TUMOR IN THE LATERAL VENTRICLE Significance of Echo-Encephalography

The authors report on a case of epidermoid tumor in the lateral cerebral ventricle. Epidermoid tumors are relatively uncommon intracranial lesions and were first described by Esmarch. Till now about 300 cases have been reported. In Japan this tumor was first described by Yamamura, and since then many cases have been reported. But the one situated in the lateral ventricle has not been reported yet in this country. The significance of echo-encephalography is discussed because this procedure was very useful in determining the location and the nature of the tumor of this case.\

BRAIN SCANNING OF SUBDURAL HEMATOMA IN INFANTS AND CHILDREN

We performed 99mTc pertechnetate brain scanning 27 Limes on 15 infantile subdural hematoma cases. These scannings gave positive results in 74%, doubtfully positive in 18%, and negative in 8%. In selected cases, scans were obtained after appropriate delay periods as well as at conventional times. In some cases, scans which were initially interpreted as borderline or negative were read as definitely abnormal on delayed studies. The radioactivity in the serial blood and subdural samples was measured in a well-type scintillation counter. This study clarified a part of the biodynamic mechanism underlying the successful detection of infantile subdural hematomas by external scintillation scanning. Our result shows that both the subdural fluid and subdural neomembrane influence the production of a positive scan, but whether the isotope is localized predominantly in the membrane or in the subdural fluid depends upon the kind of radioisotope used, hematoma age, the nature of the subdural fluid and the time interval between the injection of radioisotope and scanning. The total volume of the subdural space is assessable more exactly by the isotope dilution method than by the simple 2 dimensional gamma ray image of the subdural hematoma. This tells more of the clinical value because of its importance in planning the therapy

DYNAMIC STUDY ON CEREBROSPINAL FLUID CIRCULATION AFTER SUBARACHNOID HEMORRHAGE

Alterations in the cerebrospinal fluid (CSF) circulation after subarachnoid hemorrhage (SAH) were examined in 19 patients. Sources of hemorrhage were aneurysm in 17 cases, arteriovenous aneurysm in one and unknown in one. Cistenography was performed using 1 mCi of 169Yb diethyltriaminepentaacetic acid which was given intrathecally by lumbar injection. Persistent ventricular filling was seen in 48% of the cases and transient ventricular filling in 33%. The radioactivity in serial blood samples was measured by a well-type scintillation counter. The relationship of cisternogram to classification of patient s condition by Hunt was found to be closely related to the degree of abnormality of CSF circulation. The patient s history of rebleeding was also found to influence the degree of abnormality in CSF circulation. In regard to the site of aneurysms, those in the circle of Willis appeared to cause norm al pressure hydrocephalus more frequently. Shunt operation was performed on 6 cases, 4 of whom showed improvement. Indications for shun t were determined according to clinical syndrome and diagnostic tests such as angiography, pneumoencephalography and cisternography. In addition to these, test for radioactivity in the peripheral blood was found useful for evaluation of the condition in CSF circulation

RADIOISOTOPE SCANNING FOR THE SPINAL CORD TUMOR

Radioisotope scanning with 99mTc-pertechnetate or 67Ga-citrate for the spinal cord tumors was reported. Six patients with spinal cord tumors including 2 ependymomas, 1 neurinoma, 1 metastatic medulloblastoma, 1 metastatic astrocytoma, and 1 metastatic pinealoma as well as 6 patients with non-neoplastic lesions were examined with this method. Two out of 6 cases with tumors showed positive scans and two equivocal scans. This new method is different from myeloscintigraphy and radioisotope angiography as already reported. It directly demonstrates tumor itself like brain scanning and is very useful as nontraumatic method for screening spinal cord lesions, especially in poor risk patient. The usefulness and limitation of this method are discussed