Auroral vortex street formed by the magnetosphere-ionosphere coupling instability

By performing three-dimensional nonlinear MHD simulations including Alfven eigenmode perturbations most unstable to the ionospheric feedback effects, we reproduced the auroral vortex street that often appears just before substorm onset. We found that an initially placed arc splits, intensifies, and rapidly deforms into a vortex street. We also found that there is a critical convection electric field for growth of the Alfven eigenmodes. The vortex street is shown to be a consequence of coupling between the magnetospheric Alfven waves carrying field-aligned currents and the ionospheric density waves driven by Pedersen/Hall currents.Comment: 7 pages, 6 figures, submitted to Ann. Geophy

Studies on the treatment of malignant tumors with fibroblast-inhibiting agent III. Effects of chloroquine on human cancers

A fibroblast-inhibiting agent, chloroquine, used in the treatment of animal tumors led to a reasonably good result, and this approach was extended to the treatment of human cancers. Of histologically proven 54 cases, the drug was effective in 38, ineffective in 15, and unknown in one. It proved to be effective in all the patients who were treated for over 2 months with exception of terminal patients. Of the various malignant tumors treated, excellent therapeutic effects were obtained in patients with carcinoma of the lung and bladder. In the cases where the drug was effective there were a decrease of the size of tumors, fall of serum lactic dehydrogenase, increase of necrosis, inhibition of the stroma, as well as improvement of the symptoms and general condition. As to the mechanisms of the drug action, it would be necessary to consider of its anti-inflammatory and humoral effects upon the host in addition to its inhibitory action on the stromal connective tissue of cancers. The present chloroquine treatment appears to have its indication in inoperable cases, and pre- and post-operative cases, and for the prevention of reccurrence of tumors. Studies are currently in progress in our laboratory to discover more potent fibroblastinhibiting agents and on the combined chemotherapy of chloroquine and other anti-turnor agents. We are indebted to the Department of Urology of our University for the generosity to allow us to use the clinical data on patients with cancer of the urinary bladder.</p

Blood vessels and their construction in the cavities of pulmonary tuberculosis

First of all, we investigated the origin, the construction and distribution of the bronchial arteries and veins in adult rabbits, and then observed various changes of the blood vessels in experimental cavities and caseous foci and also studied the effects of streptomycin and isoniazide on the blood vessels of the cavity wall. The summary findings of the present experiments are described in the following. 1) In ten out of the fifteen rabbits emloyed, the bronchial artery originates from the right supreme intercostal artery; in three cases, in addition to this origin, it originates also from the left supreme intercostal artery; and in another case from the intercostal thoracic artery; while in the remaining one from the arc of the aorta. 2) The bronchial veins are divided into the extra-pulmonary and the intra-pulmonary veins. The former arises from the submucous blood vessels located in the proximal part of the third bronchus, and running along with the bronchial artery, finally empties into the superior Vena cava; while the latter, originating from the submucous capillaries in the distal part of the third bronchus, and after anastomosing with one another in the capsule of the bronchus, is communicated with the pulmonary veins. 3) In the caseous foci, although blood vessels are obliterated, capillaries are newly formed around the main trunks of the pulmonary artery and vein as well as around their residual branches. 4) These caseous foci are supplied with arterial blood from the bronchial arteries, the blood vessels in the bronchial wall, and the newlyformed vessels of pulmonary arterial origin. 5) The capillaries in the cavity wall are classified into three types according to their origins; namely, Type I, those regenerating from fine branches of the pulmonary vessels; Type &#8545;, those regenerating from the main trunk of the pulmonary vessels; and Type &#8546;, those regenerating from the bronchial artery situated in the orifice of the drainage bronchus. 6) The tuberculous cavities only in the orifice of the drainage bronchus receive an abundant supply of arterial blood directly from the bronchial artery, but those in other regions receive a scanty blood supply indirectly from the anastomoses between the bronchial artery, its sister vessels and the pulmonary artery. 7) The regeneration of blood vessels in tuberculous foci has been confirmed to occur not only in the bronchial artery and its sister blood vessels but also in the pulmonary artery and vein as well. 8) The constructions of blood vessels in the cavities treated with streptomycin or isoniazide present no significant difference from those of the control. 9) The regeneration of blood vessels and hyperemia in the cavity wall of the cases treated with streptomycin present no significant difference from those observed in the control, but the cases treated with isoniazide show marked hyperemia, newly-formed vessels, and occasional bleedings.</p

Evaluation of renal function by dynamic MR imaging: effect of water load.

The aim of this study was to investigate the usefulness of magnetic resonance (MR) imaging in the evaluation of renal function, with particular attention to the effects of water load. Ten healthy volunteers underwent dynamic MR imaging after an injection of gadolinium diethylene-triaminepenta-acetic acid (Gd-DTPA) as a contrast agent to evaluate renal function by the following four methods: the positive method [longitudinal relaxation time (T1) shortening is the dominant effect], the negative method [transverse relaxation time (T2) shortening is the dominant effect] and two intermediate methods by switching the Gd-DTPA concentrations used in the positive and negative methods. A prolonged cortical peak time and a reduced medullary peak level were observed by the positive method under a dehydrated condition, suggesting that these variables were slightly influenced by Gd-DTPA concentrated in the medulla. By the negative method, low signals due to T2* (T2* is the effective transverse relaxation time, typically shorter than T2) shortening appeared in the medulla under normal conditions, but these signals were unclear when the subject was under an overhydrated condition. These results indicate that water metabolism, in addition to imaging parameters and Gd-DTPA dose levels, should be considered when renal function is evaluated by dynamic MR imaging. Analysis of both the pattern of MR images and the time-signal intensity curves may be useful in the evaluation of renal function. The results also indicate that the positive method is preferred when the patient is overhydrated as it allows the evaluation of the local renal kinetic function by recording changes in the regional contrast agent levels.</p

Influences of various hormones on the megakaryocyte in bone-marrow tissue culture

In our study on the influences of various hormones and various endocrines on the megakaryocyte function by means of bone-marrow tissue culture, we obtained the following. 1. In the repeated administration of ACTH, cortisone, testosterone, progesterone, or thyroxin to guinea pigs, these hormones accelerated the megakaryocyte function, whereas estradiol on the contrary diminished the function. 2. The removal of such endocrines as the pituitary, adrenal, thyroid or testicles will diminish the megakaryocyte function, while removal of the ovaries accelerates it. 3. For the megakaryocytes in the hypophysectomized rats, ACTH acts most effectively to restore their function, followed by cortisone and pulverized thyroid, while testosterone has hardly any effect on the function. 4. ACTH, cortisone, prednisolone, testosterone, progesterone, and pulverized thyroid act directly on megakaryocytes so as to accelerate their function, while estradiol diminishes the megakaryocyte function. 5. For the megakaryocytes in idiopathic thrombocytopenic purpura ACTH is most effective in restoring the function; for the megakaryocytes in hypoplastic anemia cortisone is most effective; and for the megakaryocytes in Banti's disease prednisolone is most effective in restoring the megakaryocyte function.</p

An analysis of Japanese stock return dynamics conditional on U.S. Monday holiday closures

This paper examines a unique data set consisting of Japanese equity returns for the Friday, Monday, and Tuesday surrounding U.S. Monday holiday closures. The objective is to neutralize the impact of spillover effects from New York to Tokyo. Prior studies find that Japanese returns are negative on Tuesday and anomalous; this phenomenon is known as the Japanese-Tuesday effect. One explanation for the Japanese-Tuesday effect is that there exists a cause and effect relationship with Monday returns in New York. Historically, Monday returns in New York are negative, a phenomenon known as the U.S.-Monday effect. The empirical results show that U.S. Monday closures have a significant impact on Japanese return dynamics for surrounding trading days. The empirical evidence does not support the hypothesis that the U.S.-Monday and Japanese-Tuesday effects are related. Potential explanations for the occurrence and then disappearance of the Japanese-Tuesday effect rely on microstructure properties unique to Tokyo. More recently, spillover effects from New York to Tokyo have increased in intensity, and this is attributed to the introduction of the Nikkei 225 index on the SIMEX.Financial markets ; International finance ; Japan ; Stock market

Hepatic infarction following abdominal interventional procedures.

To clarify the incidence, background, and progress of hepatic infarction following interventional procedures, cases of hepatic infarction following interventional procedures at our department during the last decade were identified by reviewing the clinical records of 1982 abdominal angiography and interventional procedures and records of abdominal CT. Nine episodes (0.5%) in 8 patients were identified as hepatic infarction following an interventional procedure. Five episodes were preceded by embolization of the hepatic or celiac artery at emergency angiography for postoperative bleeding with hemorrhagic shock. Three episodes followed the elected interventional procedure for hepatocellular carcinoma, and the remaining episode occurred after 12 months of chemoinfusion through an indwelling catheter in the hepatic artery and portal vein. Hepatic arterial occlusion in all episodes and portal venous flow abnormality in 5 episodes were observed on angiography. Four patients whose liver function was initially impaired died of hepatic infarction, although the extent of the disease on CT did not appear to be related to the mortality. Multiple risk factors, including arterial insufficiency, were observed in each patient. The incidence of hepatic infarction following interventional procedures in this series was low but sometimes fatal, and occurred most frequently in emergency embolization in hemorrhagic shock.</p