The relative biological effectiveness of 10B-neutron capture therapy for early skin reaction in the hamster

The relative biological effectiveness (RBE) of 10B-neutron capture therapy (BNCT) on skin was analyzed using hamsters. The Kyoto University Research Reactor, which has a very low contamination of gamma rays and fast neutrons, was used as a thermal neutron source. Boron-10-para-boronophenylalanine hydrochloride ([10B]BPA.HCl) was administered to the hamsters. The evolution and time course of early skin reactions were assessed. These reactions were compared with those produced by electron beams. The maximum safe skin doses (no more than moist desquamation) of BNCT and electron beams were established to be 11 and 21 Gy, respectively. The RBE at this single dose with BNCT was found to be 1.94, assuming that the RBE of the gamma rays was 1.0 and each component of BNCT (mixed radiations) was simply additive.     

Polynucleotide Phosphorylase from Acromobacter sp. KR 170-4

Eighty-five strains of bacteria were screened for selection of microorganisms suitable for industrial production of polynucleotides. Among these bacteria, Achromobacter sp. KR 170-4 (ATCC 21942) was found to be rich in polynucleotide Phosphorylase (PNPase) in its “salt-shockate” as compared with the other strains tested. PNPase was purified about 50-fold from the “salt-shockate” of Achromobacter sp. KR 170-4, and properties of the enzyme were elucidated. Optimal pH for reaction was 10.1. Stable pH range at 37°C was between pH 6.5 and 10.5. Optimal temperatures were 46°C for polymerization of ADP or IDP, and 43°C for CDP or UDP. The enzyme was stable below 55°C at pH 9.2. The enzyme required Mn²⁺ rather than Mg²⁺ unlike the other PNPases reported. Optimal concentration of Mn²⁺ was 6 mM.     

Interspecific differences in crustacean homologous behavior: Neural mechanisms underlying the reversal of uropod steering movement

Summary Rolling of the body in the same direction induces an asymmetrical steering movement of uropods in the opposite directions in two closely related species of crayfish. InProcambarus clarkii the uropod on the upper side is spread out and closed on the lower side, whereas inCambaroides japonicus the uropod moves in the opposite direction. The stimulus detector, the statocysts, the effector, the uropod musculature, are neither structurally nor functionally significantly different in the two species. The results indicate that the opposite responses could be ascribed to differences in the interneuronal connections within the central nervous system of these two species.     

A KOREAN PERSPECTIVE ON DEVELOPING A GLOBAL POLICY FOR ADVANCE DIRECTIVES

Despite the wide and daunting array of cross‐cultural obstacles that the formulation of a global policy on advance directives will clearly pose, the need is equally evident. Specifically, the expansion of medical services driven by medical tourism, just to name one important example, makes this issue urgently relevant. While ensuring consistency across national borders, a global policy will have the additional and perhaps even more important effect of increasing the use of advance directives in clinical settings and enhancing their effectiveness within each country, regardless of where that country's state of the law currently stands. One cross‐cultural issue that may represent a major obstacle in formulating, let alone applying, a global policy is whether patient autonomy as the underlying principle for the use of advance directives is a universal norm or a construct of western traditions that must be reconciled with alternative value systems that may place lesser significance on individual choice. A global policy, at a minimum, must emphasize respect for patient autonomy, provision of medical information, limits to the obligations for physicians, and portability. And though the development of a global policy will be no easy task, active engagement in close collaboration with the World Health Organization can make it possible.     

A novel group of sperm activating peptides from the sea urchin Glyptocidaris crenularis

1. Six new sperm activating peptides were purified from the egg jelly of the sea urchin Glyptocidaris crenularis and their amino acid sequences were determined as follows: Ser-Ala-Lys-Leu-Cys-Pro-Gly-Gly-Asn-Cys-Val, Lys-Leu-Cys-Pro-Gly-Gly-Asn-Cys-Val, Leu-Cys-Pro-Gly-Gly-Asn-Cys-Val, Ser-Phe-Lys-Leu-Cys-Pro-Gly-Gly-Gln-Cys-Val, Lys-Leu-Cys-Pro-Gly-Gly-Gln-Cys-Val and Leu-Cys-Pro-Gly-Gly-Gln-Cys-Val. 2. The peptides were specific for G. crenularis spermatozoa and caused significant increases of sperm respiration rates and sperm cyclic nucleotide concentrations at concentrations as low as 10(-10) M. 3. The addition of the peptides to intact spermatozoa resulted in the change of the apparent mol. wt of a sperm protein from 195,000 to 200,000.     

Stabilization of the adenylate energy charge in erythrocytes of rats and humans at high altitude hypoxia.

1. Stabilization of adenylate energy charge and control of adenylate pool were analysed in the erythrocytes of the rat and the human exposed to highly hypoxic conditions. 2. Red cell energy charge was decreased in the rats exposed to a simulated altitude of 5000-8000 m, and then recovered to the normal value with the depletion of adenylate pool. 3. The energy charge and the adenylate pool size of the human erythrocytes did not show any change under highly hypoxic conditions. 4. Anaerobic incubation of rat erythrocytes caused a marked decrease in the energy charge, and its recovery was accompanied by the depletion of total adenylates. 5. The energy charge and total adenylates of human red cells did not change under the anaerobic incubation of erythrocytes. 6. These results suggest that the energy charge of rat erythrocytes can be controlled by depletion of the adenylate pool, but the adenylate degradation is not responsible for the stabilization of the energy charge in human erythrocytes.