A histochemical study of the innervation of cerebral blood vessels in the snake

Dual innervation of snake cerebral blood vessels by adrenergic and cholinergic fibres was demonstrated with the use of histochemical methods. Although the nerve plexuses are somewhat less dense, the essential features of innervation of the blood vessels are similar to those of mammals with the exception that the adrenergic plexuses are more prominent than the cholinergic plexuses. The major arteries of the cerebral carotid system have a rich nerve supply. However, the innervation is less rich in the basilar and poor in the spinal (vertebral) arteries. Although the arteries supplying the right side of head are poorly developed, three pairs of arteries, cerebral carotids, ophthalmics and spinals, supply the snake brain. The carotids and ophthalmics are densely innervated and are accompanied by thick nerve bundles, suggesting that the nerves preferentially enter the skull along those arteries. Some parenchymal arterioles are also dually innervated. Connection between the brain parenchyma and intracerebral capillaries via both cholinergic and adrenergic fibres was observed. In addition cholinergic nerve fibers, connecting capillaries and the intramedullary nerve fibre bundles, were noticed. Capillary blood flow may be influenced by both adrenergic and cholinergic central neurons. The walls of capillaries also exhibit heavy acetylcholinesterase activity. This may indicate an important role for the capillary in the regulation of intracerebral blood flow.     

C16 hydroxylation of 3beta-hydroxy-delta5-steroids during the early neonatal period

Temporal changes of the serum levels of 16-hydroxypregnenolone (3beta,16alpha-dihydroxy-5-pregnen-20-one) 3-sulfate (16-OH-Preg S) and 16-hydroxydehydroepiandrosterone (3beta,16alpha-dihydroxy-5-androsten-17-one) 3-sulfate (16-OH-DHEA S) were investigated by analyzing the levels of their precursor steroids, pregnenolone (3beta-hydroxy-5-pregnen-20-one) 3-sulfate (Preg S) and dehydroepiandrosterone (3beta-hydroxy-5-androsten-17-one) 3-sulfate (DHEA S), respectively, in the early neonatal period. The serum levels of these steroids were measured by GC-MS in full-term (gestational age: 37-41 weeks), pre-term (gestational age: 28-36 weeks) and extremely immature (gestational age: 24-27 weeks) infants. The changes in 16-hydroxysteroid production were also investigated by analyzing the ratios of the serum levels of 16-OH-Preg S and Preg S (16-OH-Preg S/Preg S ratio), and 16-OH-DHEA S and DHEA S (16-OH-DHEA S/DHEA S ratio). It was confirmed that the 16-hydroxylation of DHEA S and Preg S increased after birth, and the 16-OH-Preg S/Preg S ratio in full-term infants was significantly higher than in pre-term and extremely immature infants at days 0, 1-6 and 7-13. On the other hand, there were no significant differences between the 16-OH-DHEA S/DHEA S ratios of the three groups at days 0, 1-6 or 7-13. The mechanism of differences in the 16-hydroxylation of Preg S and DHEA S is also discussed.     

Role of coronary artery spasm in progression of organic coronary stenosis and acute myocardial infarction in a swine model. Importance of mode of onset and duration of coronary artery spasm

BACKGROUND: Coronary spasm may play an important role in progression of organic coronary stenosis and myocardial infarction, but the mechanisms responsible for these complications are not known. This study aimed to examine whether the mode of onset and the duration of coronary spasm influenced progression of organic coronary stenosis and acute myocardial infarction in a swine model of coronary spasm. METHODS AND RESULTS: G?ttingen miniature pigs were subjected to cholesterol feeding, balloon-induced coronary arterial denudation, and x-ray irradiation. Five months later, coronary spasm was induced by intracoronary injection of serotonin. In 10 pigs, coronary spasm was provoked abruptly and maintained for 25 minutes by five repeated intracoronary injections of serotonin (10 micrograms/kg) every 5 minutes (group A, abrupt onset and short duration). In group B, coronary spasm was provoked gradually by intracoronary injections of serotonin at graded doses of 0.1, 0.3, and 0.6 microgram/kg every 5 minutes and was then maintained for 25 minutes in four pigs (group B1, gradual onset and short duration) and for 120 minutes in six pigs (group B2, gradual onset and long duration) by repeated intracoronary injections of serotonin (10 micrograms/kg) every 5 minutes. Intramural hemorrhage was noted histologically at the spastic site more frequently in group A with abrupt onset (nine of 10 pigs) than in group B with gradual onset (two of 10 pigs) (p < 0.01). Progression of organic coronary stenosis due to intramural hemorrhage was noted in seven pigs (six pigs in group A and one pig in group B), including three cases of total coronary occlusion. Evidence for the evolution of acute myocardial infarction (serial ECG findings, left ventriculograms, and histological findings) was noted in one pig (7%) of group A or B1 with short duration and in five of six pigs (83%) in group B2 with long duration (p < 0.01 versus group A and B1). CONCLUSIONS: These results indicate that: 1) intramural hemorrhage was frequently induced by coronary spasm of abrupt but not of gradual onset, 2) intramural hemorrhage resulted in acute progression of coronary stenosis and sometimes resulted in persistent total coronary occlusion leading to acute myocardial infarction, and 3) prolonged coronary spasm resulted in acute myocardial infarction without progression of organic coronary stenosis.     

Status and perspective of the Nb3Al development

Nb₃Al has advantages of better tolerance to strain/stress and a higher critical magnetic field (30 T at 4.2 K) for stoichiometric composition over Nb₃Sn. The rapid-heating, quenching and transformation annealing (RHQT) process enables to form a stoichiometric Nb₃Al with fine grain structures via metastable bcc supersaturated-solid-solution. As a result a large critical current density of Nb₃Al is achieved over the whole range of magnetic fields without trading off the excellent strain tolerance. A long-length of RHQ processing has been established, and a rectangular but Cu stabilized Nb₃Al strand is about be commercially available for NMR uses. Ag or Cu internal stabilization and Cu ion-plating/electroplating techniques have been also developed to enable the stabilized round wire for accelerator and fusion magnets. Successfully energized test coils that were manufactured with a wind-and-react technique have demonstrated that a long piece of Cu stabilized RHQT Nb₃Al wire is really available for practical applications.     

Transfer hydrogenation and transfer hydrogenolysis: XII. Selective hydrogenation of fatty acid methyl esters by various hydrogen donors

The selective hydrogenation of methyl linoleate was studied using various organic compounds as hydrogen sources in the presence of homogeneous and metallic palladium catalysts. Complete selectivity to monoenes and relatively little formation of isolatedtrans double bonds were realized by the hydrogen transfer from L-ascorbic acid at 47% conversion of starting material to hydrogenation products. The hydrogenation bytrans-1,2-cyclohexanediol catalyzed by RuH₂(PPh₃)₄ also showed rather high selectivity tocis-monoenes. In the reaction catalyzed by RuH₂(PPh₃)₄, also showed rather high selectivity tocis-monoenes. In the reaction catalyzed by RuH₂(PPh₃)₄, the presence of these hydroxy compounds increased the isomerization of methyl elaidate tocis-monoenes.     

Fc-Binding Antibody-Recruiting Molecules Targeting Prostate-Specific Membrane Antigen: Defucosylation of Antibody for Efficacy Improvement**

Synthetic small molecules that redirect endogenous antibodies to target cells are promising drug candidates because they overcome the potential shortcomings of therapeutic antibodies, such as immunogenicity and the need for intravenous delivery. Previously, we reported a novel class of bispecific molecules targeting the antibody Fc region and folate receptor, named Fc-binding antibody-recruiting molecules (Fc-ARMs). Fc-ARMs can theoretically recruit most endogenous antibodies, inducing antibody-dependent cell-mediated cytotoxicity (ADCC) to eliminate cancer cells. Herein, we describe new Fc-ARMs that target prostate cancer (Fc-ARM-Ps). Fc-ARM-Ps recruited antibodies to cancer cells expressing prostate-specific membrane antigen but did so with lower efficiency compared with Fc-ARMs targeting the folate receptor. Upon recruitment by Fc-ARM-P, defucosylated antibodies efficiently activated natural killer cells and induced ADCC, whereas antibodies with intact N-glycans did not. The results suggest that the affinity between recruited antibodies and CD16a, a type of Fc receptor expressed on immune cells, could be a key factor controlling immune activation in the Fc-ARM strategy.     

Numerical study on the effects of linear protrusion on flow-induced carriage excitation force in hard disk drives

The positioning accuracy of magnetic heads needs to be improved to increase the recording capacity of hard disk drives. In our previous study, experimental results confirmed that the head-positioning error could be decreased by attaching linear protrusions on the leading edge of the carriage arms. However, the mechanism underlying the phenomenon has not been elucidated. In the present research, we evaluated the effect of leading-edge protrusions on the flow-induced carriage excitation force using computational fluid dynamics (CFD) analysis and the Hilbert–Huang transform (HHT). We prepared two carriage-arm models, with and without linear protrusions, on the leading edges of the arm, and performed the CFD analyses. Subsequently, we conducted a frequency analysis by applying HHT to the simulated disturbance torque time-series of each carriage-arm model and compared the results. Our results show that the leading-edge protrusions decrease the disturbance torque due to the flow fluctuation between the arm and disk and in the wake flow, although the low-frequency disturbance torque due to the pulsatile flow can be deteriorated.

     

TOF-SIMS analysis of perfluoropolyether lubricant smear transferred from disk surface following laser heating

Microsystem Technologies - The structural and molecular weight changes of perfluoropolyether lubricant picked up following laser heating in heat-assisted magnetic recording (HAMR) were analyzed...