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Intraventricular hemorrhage (IVH) in preterm infants is well known to be associated with the high morbidity and mortality of this group. Previous studies have suggested altered cerebral blood flow (CBF) as an important pathologic factor. We measured the CBF in nearterm rabbit fetuses using the hydrogen clearance technique. The local CBF of the rabbit fetuses was significantly low compared with that of the maternal rabbits. The response of CBF to changes in PaCO2 was observed in rabbit fetuses. The CO2 reactivity index of the fetal rabbit was lower than that of the maternal rabbit. This low CO2 reactivity might reflect the immaturity of the fetal brain and its low CBF. We were unable to monitor the fetal blood pressure, but the fetal CBF remained stable when the maternal blood pressure was altered. It is well known that IVH in preterm infants originates from the subependymal germinal matrix and that this has many fragile vessels. Our observation suggests that even a small increase of CBF during hypercapnia might have a large effect towards producing hemorrhage. 相似文献
3.
M Nakayama Y Takahashi H Itoh K Kamiya M Shiratsuchi G Otani 《The Journal of antibiotics》1989,42(11):1535-1540
Two antifungal antibiotics maniwamycins A and B were isolated from the culture broth of a strain of actinomycetes, which were classified as Streptomyces prasinopilosus. These antibiotics were isolated by resin absorption and extraction with EtOAc and purified by column chromatography. Both antibiotics were found to be new azoxy substances from their physico-chemical properties. They showed broad antifungal spectra. 相似文献
4.
Hiroto Egawa Shingi Uemoto Yasutugu Takada Kazue Ozawa Satoshi Teramukai Hironori Haga Mureo Kasahara Kouhei Ogawa Hiroshi Sato Masako Ono Kenji Takai Masanori Fukushima Kayo Inaba Koichi Tanaka 《Liver transplantation》2007,13(9):1262-1271
We have found that steroid bolus withdrawal prior to graft reperfusion increased the incidence of acute cellular rejection (ACR). This study aims to clarify how initial steroid bolus (ISB) injection at reperfusion influences the kinetics of CD8(+) alloreactive immune responses immediately after living donor liver transplantation (LDLT). A total of 49 hepatitis C virus (HCV)-infected recipients were classified into 3 groups according to hierarchical clustering by preoperative CD8(+)CD45 isoforms. The naive T cell proportion was considerably higher in Group I than in Groups II and III, whereas Group II recipients had the highest effector memory (EM) T cells and Group III the highest effector T cells. The frequency of ACR was significantly higher in recipients without ISB than in those with ISB. In particular, the ACR rates were the highest in Group II without ISB. Following ISB, the proportion of effector T cells was promptly upregulated within 6 hours after graft reperfusion, simultaneously with the upregulation of CD27(-)CD28(-) subsets, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha and perforin expression, which significantly correlated with increasing interleukin (IL)-12 receptor beta 1 cells. These were then downregulated to below preoperative levels by tacrolimus (Tac) administered at 24 hours. These changes did not occur in the absence of ISB. In Group II without ISB, the downregulation of IL-12Rbeta1(+) cells was the greatest, consistent with the highest rates of ACR and mortality (60%). In conclusion, ISB must be done in place, especially in Group II with preexisting high EM T cells, to enable the development of early allograft acceptance. 相似文献
5.
Purification and characterization of aplysianin E, an antitumor factor from sea hare eggs 总被引:1,自引:0,他引:1
An antitumor factor, aplysianin E, inducing tumor lysis was purified to apparent homogeneity from the supernatant of a homogenate of eggs of the sea hare Aplysia kurodai. Purified aplysianin E was a 250-kDa glycoprotein containing three different subunits. This factor was half-maximally active at 2-114 ng protein/ml and lysed all the tumor cells tested but did not lyse normal white or red blood cells. Aplysianin E was labile on treatments with heat, low pH, urea, guanidine, sodium lauryl sulfate, and periodate, but not with proteases or organic solvents, Aplysianin E completely inhibited the syntheses of DNA, RNA, and protein by tumor cells within 2 h and caused their complete cytolysis within 15 h. Tumor lysis by aplysianin E was inhibited by N-acetylneuraminic acid, suggesting that recognition of the sugar moiety is a key step in cytolysis induced by aplysianin E. Aplysianin E also prolonged the survival of mice bearing syngeneic MM46 ascites or solid tumors. These results suggest that aplysianin E, found in an invertebrate, the sea hare, is a new antitumor factor. 相似文献
6.
Resetting of the arterial baroreflex increases orthostatic sympathetic activation and prevents postural hypotension in rabbits 总被引:1,自引:1,他引:0
Atsunori Kamiya Toru Kawada Kenta Yamamoto Daisaku Michikami Hideto Ariumi Kazunori Uemura Can Zheng Syuji Shimizu Takeshi Aiba Tadayoshi Miyamoto Masaru Sugimachi Kenji Sunagawa 《The Journal of physiology》2005,566(1):237-246
Since humans are under ceaseless orthostatic stress, the mechanism to maintain arterial pressure (AP) under orthostatic stress against gravitational fluid shift is of great importance. We hypothesized that (1) orthostatic stress resets the arterial baroreflex control of sympathetic nerve activity (SNA) to a higher SNA, and (2) resetting of the arterial baroreflex contributes to preventing postural hypotension. Renal SNA and AP were recorded in eight anaesthetized, vagotomized and aortic-denervated rabbits. Isolated intracarotid sinus pressure (CSP) was increased stepwise from 40 to 160 mmHg with increments of 20 mmHg (60 s for each CSP level) while the animal was placed supine and at 60 deg upright tilt. Upright tilt shifted the CSP–SNA relationship (the baroreflex neural arc) to a higher SNA, shifted the SNA–AP relationship (the baroreflex peripheral arc) to a lower AP, and consequently moved the operating point to marked high SNA while maintaining AP. A simulation study suggests that resetting in the neural arc would double the orthostatic activation of SNA and increase the operating AP in upright tilt by 10 mmHg, compared with the absence of resetting. In addition, upright tilt did not change the CSP–AP relationship (the baroreflex total arc). A simulation study suggests that although a downward shift of the peripheral arc could shift the total arc downward, resetting in the neural arc would compensate this fall and prevent the total arc from shifting downward to a lower AP. In conclusion, upright tilt increases SNA by resetting the baroreflex neural arc. This resetting may compensate for the reduced pressor responses to SNA in the peripheral cardiovascular system and contribute to preventing postural hypotension. 相似文献
7.
Kouhei Akazawa 《Journal of medical systems》1997,21(4):229-238
This paper describes a measure of explained variation (MEV) of survival times for a given regression model used in survival analysis. It quantifies the predictive power of a set of prognostic factors in the model, and therefore provides useful information for more precise prediction of patient prognosis, and for designing randomized clinical trials with the capability of determining treatment effects. The MEV defined in this article is asymptotically derived from the squared product-moment correlation; it can be interpreted as an adaptation of the multiple correlation coefficient for the normal linear model to the survival time regression model. Monte-Carlo simulations are performed to investigate the statistical behavior of the proposed MEV. The MEV is applied to estimate the predictive power of several sets of prognostic factors for gastric cancer in Japan using data from a large clinical trial. 相似文献
8.
9.
Clinical significance of selective middle hepatic venography 总被引:1,自引:0,他引:1
Selective middle hepatic venography was performed in 86 patients who had been scheduled to undergo liver resection because of hepatobiliary diseases. Special catheters were used of which tips were bended counterclockwise at an angle of 45 degrees. Successful middle hepatic venograms were obtained in 65 cases (76%). Abnormal findings were observed in 27 cases (42%), and it was difficult to diagnose them by ultrasonography or computed tomography. Selective middle hepatic venogram is very useful to understand surgical anatomy of the liver in each case preoperatively. In 5 cases of giant tumor, middle hepatic venography is necessary to identify the exact site of the tumor. Selective middle hepatic venography is considered to be one of the indispensable, examinations for liver resection. 相似文献
10.