Identification of 45 New Neutron-Rich Isotopes Produced by In-Flight Fission of a 238U Beam at 345 MeV/nucleon

A search for new isotopes using in-flight fission of a 345 MeV/nucleon 238U beam has been carried out at the RI Beam Factory at the RIKEN Nishina Center. Fission fragments were analyzed and identified by using the superconducting in-flight separator BigRIPS. We observed 45 new neutron-rich isotopes: 71Mn, 73,74Fe, 76Co, 79Ni, 81,82Cu, 84,85Zn, 87Ga, 90Ge, 95Se, 98Br, 101Kr, 103Rb, 106,107Sr, 108,109Y, 111,112Zr, 114,115Nb, 115,116,117Mo, 119,120Tc, 121,122,123,124Ru, 123,124,125,126Rh, 127,128Pd, 133Cd, 138Sn, 140Sb, 143Te, 145I, 148Xe, and 152Ba

DORSAL ROOT REGENERATION INTO TRANSPLANTS OF DORSAL OR VENTRAL HALF OF EMBRYONIC SPINAL CORD

Adult cut dorsal root axons regenerate into the transplants of embryonic spinal cord (ESC) and form functional synapses within the transplants. It is unknown whether the growth is specific to transplants of dorsal half of ESC, a normal target of most dorsal root axons, or whether it is due to properties shared by transplants of ventral half of ESC. We used calcitonin gene-related peptide (CGRP) immunohistochemistry to label to the subpopulations of regenerated adult dorsal root axons, quantitative analysis to compare the extent of dorsal root regeneration, and also compare neuronal composition within both transplants. Adult Sprague-Dawley rats received intraspinal grafts of dorsal or ventral half ESC (E14), and the L4 or L5 dorsal root was cut and juxtaposed to the transplants. Three months later sagittal sections were prepared for CGRP immunohistochemistry and Nissl-Myelin stain. Dorsal root axons regenerated into both kinds of transplants, but growth into dorsal half of ESC was more robust than that into ventral half of ESC. Histograms of the perikaryal area showed that the transplants of dorsal half ESC consisted of small neurons predominantly, whereas transplants of ventral half ESC consisted neurons of variable sizes with abundant myelination. These results indicate that both kinds of ESC may help to rebuild damaged spinal reflex circuits after spinal cord injury

REMARKABLE INCREASE OF CYTOCHROME C OXIDASE SUBUNIT I AFTER GLOBAL CEREBRAL ISCHEMIA

Cerebral ischemia is known to produce excessive reactive oxygen species (ROS) in mitochondria, and these radicals initiate radical chain reactions, causing cellular macromolecule damage and also promote mitochondrial apoptosis pathway, ultimately leading to cell death. However, little is known about the mitochondrial functional change after ischemia. We studied expression of cytochrome c oxidase (COX), a terminal, rate-limiting enzyme of the respiratory chain to generate ATP, after global cerebral ischemia in rats. Immunofluorescent staining and Western blot were performed to investigate the spatial and temporal changes in two important COX subunits, mitochondria- encoded COX subunit I (COX I) and nucleus-encoded COX subunit IV (COX IV). In normal condition, these subunits have to be precisely regulated in a 1 : 1 stoichiometry to assemble functional COX holoenzyme. In this study, a massive increase in COX I, which is disproportionate to COX IV was observed at 1 and 6 h after lethal ischemia, preceding delayed neuronal death. In contrast to lethal ischemia, mild sublethal ischemia did not elicit obvious alteration in COX I and IV. This aberrant increase in COX I may be an early sign of delayed neuronal death or may predict later electron transport chain dysfunction to generate ATP