85 research outputs found
Dissecting the multifaceted mechanisms that drive leafhopper host-phytoplasma specificity.
No full textPlant pathogen-vector complexes cause some of the most important diseases of crops worldwide, and are among the most difficult to manage effectively. Novel strategies are now needed for their management based on mechanistic understanding of transmission processes. Since the publication by Academic Press of a four-volume series on Vector Biology by Maramorosch et al during the 1970-80’s’s there have been no follow-on reference books that offer a contemporary treatment of pathogen-vector interactions and vector biology. The chapters in the proposed book will be written by well-known vector biologists from the fields of entomology and plant virology and pathology, in the instances for which it was possible, the authors together represent both perspectives. Several chapters are authored by experts outside the arena of vector interactions, but bring valuable, cross-disciplinary perspectives to relevant aspects of many vector-transmission systems, in particular the chapter on saliva and chemical ecology of plant vector-host interactions. The inclusion of chapterlets on ‘emerging pathogen-complexes is suggested in order to raise awareness of these newly occurring diseases that remain poorly studied and whose inclusion in the book will highlight the need for attention by the community. In any case, each author brings expertise and breadth in pathogen-vector interactions in distinct focus areas. For certain systems the level of knowledge is in its infancy (emergent), while for others specific molecular and cellular components are well known to govern the transmission processes, while others are in intermediate stages of elucidation. A Glossary of Terms is planned and Elaine Backus (entomology, feeding behavior) has agreed to take the lead on this section and J.K. Brown will work with her to bring the virology perspective
Studies on the Effect of Oxygen Inhalation Part 2. Histogic Changes caused by the Repeated Oxygen Inhalation
No full textBy observing the organs from the animals killed after the various durations of oxygen inhalation, the author reveals the following histologic changes: The inhalation of O(2), 12 houts daily, results in the heavy depostion of hemosiderin in the liver and spleen with the capillary stagnation. The severe damages in the wall of artery and arterioles are the general changes. These damages found in the vascular system will be responsible for the other histologic changes, perivascular edema and cell infiltration, thickening of the alveolar wall with the cell proliferation, localized degenerative changes of heart muscle, alternative degeneration and regeneration in the liver parenchym and the slight atrophy of glomerulus in the kidney. Active erythropoietic picture can be seen in bone marrow but decreaded number in normoblasts. The view of the author is that these changes will be the toxic action of O(2) desolved in blood plasm, which may have an active oxidizing effect. The reduction oferythrocyte number seems to be caused by the inhibition of maturation oferythroblasts, and the increased demolition of red cells in the circulating blood
Studies on the Neutralization Test of Rickettsia tsutsugamushi I: Studies on Various Factors of Neutralization Test
No full textAs the factors influencing the neutralization test of rickettsiae, the following ones have been given; mouse organs employed, unequal distribution of rickettsiae in organs and determination method of the result. The author studied the influences of these factors and other various conditions on the neutralization test. Mitani strain of Rickttsia tsutsugamushi isolated from the patients of Umayado disease in Kagawa prefecture was used as the test agent. The results were as follows: 1) In the present experiment, though some errors should be taken into consideration so far as animal experiment is concerned, it was concluded that reliable result would be obtained by careful selection of the outer conditions and inner factors. 2) As the outer conditions, the experimental temperature and the solution for dilution of rickettsial emulsion are given. The temperature under 10°C is suitable for treatment of R. tsutsugamushi, and glutamine-sucrose-phosphate buffer is superior as the dilution solution. 3) As the inner factors, those of rickettsia itself and those of immune sera were considered. In orser to make the distribution of rickettsiae equal, many livers and spleens were pooled and treated at the low temperature mentioned above. The selection of immune sera is important, and the neutralization test with rabbit immune sera showed the best result. 4) After some observation period of neutralization test, a few of the survived mice showed the syndrom of the disease. This result suggested that prolongation of observation period was necessary to exact determination of the result of neutralization test
Experimental Studies on the Influences of Hypotension and Hypothermia upon the Electroencephalogram and Brain Edema Part Ⅰ. On the Influences of Hypotension upon Electroencephalogram and Brain Edema
No full textMany reports have recently concerned the problems that the hypotension with autonomic nerve blocking agents are effective to prevent shock or brain edema which are often seen in craniotomy. The author studied these effects of anesthesia from the view points of electroencephalogram and brain water content. With intraperitoneal injection of 10% Dial solution for premedication, and with C(6) or Trapon as the hypotensive agents, dogs were anesthetized by endotracheal intubation with ether. In the contrast group with only Dial and ether, the increase of delta index in E.E.G. as well as that of the free and total water were seen with the lapse of time after craniotomy. In the group of hypotension (70~80 mm Hg) only with C(6) or Trapon, the increase of delta index was not seen and the brain water content showed no change. In the group of hypotension with C(6) or Trapon combined with ether anesthesia, slight decrease of delta index was seen and the brain water content showed no change. From these results, it is proved that anesthesia with simple barbiturate or ether causes anoxia of the nerve cells, resulting in brain edema and that hypotension is effective to prevent it
Studies on the Neutralization Test of Rickettsia tsutsugamushi II: Studies on the Procedures of Neutralization Test of R. Tsutsugamushi
No full textThe author reinvestigated the procedures of neutralization test of Rickettsia tsutsugamushi in regard to the contact period of the agent with immune sera. At the same time, the "Absaettigungsversuch" (Wildfuehr) was also tried on R. tsutsugamushi. Mitani strain of R. tsutsugamushi isolated from the patients of Umayado disease in Kagawa prefecture was used as the test agent. The results were as follows: 1) In test tubes, R. tsutsugamushi combines with its antisera in a short time, and the virulence of R. tsutsugamushi falled along with prolongation of contact period. These facts suggest that estimation of the true titer of neutralization antibody become possible by the short-period-contact which causes no noticeable fall of rickettsial virulence. 2) In the neutralization test of R. tsutsugamushi, dilution of antisera to be mixed with rickettsiae in test tubes deteriorates its result, and addition of human or guinea-pig sera had no influence on its neutralizing effect. 3) No noticeable result was obtained in application of the "Absaettigungsversuch" to R. tsutsugamushi
Experimenlal Studies on the Influences of Hypotension and Hypothermia upon the Electroencephalogram and Brain Edema Part Ⅱ. On the Influences of Hypothermia upon Electroencephalogram and Brain Edema
No full textIt is known that the hypothermic anesthesia with autonomic nerve blocking agents causes not only less bleeding, but also prevents shock or brain edema which is often seen in craniotomy. The author studied these effects of potentiated narkosis or hypothermia from the view point of electroencephalogram and brain water content. With intraperitoneal injection of 10% Dial solution for premedication in all cases and with chlorpromazine as the blocking agent, dogs were anesthetized by intratracheal intubation with ether, and were cooled by ice bags until the rectal temperature became about 34°~32℃. And the following results were obtained. In the group of potentiated narkosis with Dial and chlorpromazine, the decrease of delta index was seen and the brain water contents showed no change compared with the contrast group. In the group of hypothermia with chlorpromazine, the decrease of delta index was seen and the brain water content showed no change. In the group of hypothermic anesthesia with chlorpromazine and ether, the result was the same as the former group. By this study it was explained that these effects are not only due to less dose of anesthetic agents in combination with autonomic nerve blocking agents, but also to the rare occurrence of the cerebral anoxia, and that the hypothermia is effective to prevent brain edema in craniotomy. It is also considered that the oxygen inhalation during and after the operation may preveit the so-called brain swelling
Concise [4+3] cycloaddition reaction of pyrroles leading to tropinone derivatives
No full textA concise [4+3] cycloaddition reaction of pyrroles with 2-(silyloxy)allyl cations has been developed. The oxyallyl cations stabilized with a methylthio group or geminal methyl groups were generated from the corresponding allylic alcohols under the influence of a Brönsted acid (Tf2NH), respectively. The use of N-nosyl-protected pyrroles as the four-carbon unit was found to give tropinone derivatives in high yield
Studies on Rickettsia tsutsugamushi Ⅰ: The Investigation of Immunity by means of the Seroreaction with the Flocculation Antigen and the Particle-Absorbed-Antigen
No full textThe peritoneal exudate containing a large amount of rickettsiae were obtained by intraperitoneal inoculation of Rickettsia tsutsugamushi into the guinea-pigs previously injected with chlorpromazine. The antigenic substance of thus obtained peritoneal exudate was absorbed on bentonite and pine-resin particles, and was used as the agglutination antigen. The flocculation antigen was prepared from the lung of the mice intranasally inoculated with rickettsiae. By means of the seroreaction with the use of these two sorts of antigens, the author studied the influence of the difference of the amount of rickettsiae as well as the sites of inoculation on the immunity. Intracutaneous, subcutaneous, intracerebral, intraperitoneal and intranasal routes were chosen as the sites of inoculation of living rickettsiae. The intracutaneous inoculation produced the flocculation antibodies in the largest amount, the intracerebral and subcutaneous ones the nest, and they were followed by the intraperitoneal and intranasal ones. In the case of inoculation by the routes other than nose, the antibody titer rised with the lapse of time after inoculation. When inoculated by the same route, within the range of a certain amount of rickettsiae, the difference of amount gave no influence on the production of antibodies. The agglutination reaction with the use of the particle-absorbed antigen was not feasible because of its non-special reaction
Evaluation of the pain and local tenderness in bone metastasis treated with magnetic resonance-guided focused ultrasound surgery (MRgFUS)
No full textStudies on the Effect of Oxygen Inhalation Part 1. Observation on the Blood in the Oxygen Inhalation
No full textThe changes in the general condtions and blood have been observed in the rats receiving oxygen iehalation for 12 hours a day. In the first stage when the animals are laced in an oxygen chamber, they become less active and sooner or later they fall into a sleeping state with a reduced respiation frequency without taking food. After about 20 days' training even in the oxygen atmosphere they show a little movement with some activity and a little increase in appetite. After about 30 days in the oxygen chamber they begin to act almost as if they were outside the chamber with a slight loss in body weight. Hemoglobin content of blood decreases day by day during the first 20 days, reaching a new equilibrium, 20-30 per cent of the original value, which is kept up for the following 40 days without any change. Red cell number continues to fall reaching the minimum value after about 20 to 30 days, 90 per cent of the original number, and increase gradually reaching the original level about 2 months after the initiation. The reticulocyte number increases day by day reaching the maximum of 52.3 per cent after 10 days and keeps this level till the end of the experiment, i. e for two months. Leukocyte number is kept in a normal range throughout the experimental days. From the above experimental data the author concludes that the decrease in hemoglobin content seems to be due to the toxic action of oxygen itself but far from the adaptation syndrome, as only 2 per cent or less decrease in hemoglobin can be expected from the theoretical calculation in the oxygenation rat of hemoglobin
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