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  • 1
    ISSN: 1432-0533
    Keywords: Focal cerebral ischemia ; Middle cerebral artery ; Rat ; Reperfusion ; 2,3,5-Triphenyl-tetrazolium chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The extent of histochemical change following middle cerebral artery occlusion was quantitatively determined in three groups of Sprague-Dawley rats with 2,3,5-triphenyltetrazolium chloride (a marker of mitochondrial oxidative enzyme function). In group I (n=7) occlusion was maintained for 3 h, with immediate sacrifice. In group II (n=7) occlusion was maintained for 5 h, with immediate sacrifice. In group III (n=7) occlusion was maintained for 3 h, followed by a 2-h period of reperfusion prior to sacrifice. The area of injury was significantly larger (P〈0.05) in the 5-h occlusion group [15±4% (mean±SD)] compared to the 3-h occlusion group (9±2%); indicating a time-dependent worsening of the histochemical detection of injury. However, the area of injury was significantly less in the reperfusion group (5±2%) compared to the group that was evaluated after 3 h of occlusion without reperfusion (9±2%); indicating that some component of the injury revealed by 2,3,5-triphenyltetrazolium chloride is potentially reversible. These data suggest that contrary to previous understanding, the histochemical abnormality revealed by 2,3,5-triphenyltetrazolium chloride is reversible in some circumstances and does not necessarily represent inevitable infarction.
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  • 2
    ISSN: 1432-0533
    Keywords: Blood-brain barrier ; Cerebral edema ; Cerebral ischemia ; Hypertension ; Reperfusion
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary After 180 min of temporary middle cerebral artery occlusion in rats, the affect of phenylephrine-induced hypertension on blood-brain barrier permeability was assessed. One of the following blood-pressure regimens was maintained during either a 30- or 120-min period of reperfusion: (a) 30/Norm, 30 min of normotensive reperfusion was allowed; (b) 30/HTN, mean arterial blood pressure was increased by 35 mm Hg during 30 min of reperfusion; (c) 120/Norm, 120 min of normotensive reperfusion was allowed; or (d) 120/HTN, mean arterial blood pressure was increased by 35 mm Hg during 120 min of reperfusion. Evans blue (30 mg/kg) was given, and brains were analyzed for Evans blue by spectrophotometry. Evans blue (μg/g brain tissue, mean ± SD) was greater (P〈0.05) in both hypertensive groups versus their time matched normotensive groups (30/HTN: 80±16 versus 18±6 in the 30/Norm group; 120/HTN: 17±6 versus 8±3 in the 120/Norm group). In addition, Evans blue was greater (P〈0.05) in both 30-min groups versus their pressure matched 120-min groups (30/Norm: 18±6 versus 8±3 in the 120/Norm group; 30/HTN: 80±16 versus 17±6 in the 120/HTN group). The data are consistent with previous studies which have demonstrated an opening of the blood-brain barrier at the onset of reperfusion. In addition, the data support a hypothesis that changes in blood-brain barrier permeability are more sensitive to hypertension in the early period of reperfusion.
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  • 3
    ISSN: 1432-0533
    Keywords: Focal cerebral ischemia ; Spontaneously hypertensive rat ; Hypertension ; Edema ; 2,3,5-Triphenyltetrazolium chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of induced hypertension instituted after a 2-h delay following middle cerebral artery occlusion (MCAO) on brain edoma formation and histochemical injury was studied. Under isoflurane anesthesia, the MCA of 14 spontaneously hypertensive rats was occluded. In the control group (n=7), the mean arterial pressure (MAP) was not manipulated. In the hypertensive group (n=7), the MAP was elevated by 25–30 mm Hg beginning 2 h after MCAO. Four hours after MCAO, the rats were killed and the brains harvested. The brains were sectioned along coronal planes spanning the distribution of ischemia produced by MCAO. Specific gravity (SG) was determined in the subcortex and in two sites in the cortex (core and periphery of the ischemic territory). The extent of neuronal injury was determined by 2,3,5-triphyenyltetrazolium staining. In the ischemic core, there was no difference in SG in the subcortex and cortex in the two groups. In the periphery of the ischemic territory, SG in the cortex was greater (less edema accumulation) in the hypertensive group (1.041±0.001 vs 1.039±0.001, P 〈 0.05). The area of histochemical injury (as a percent of the cross-sectional area of the hemisphere) was less in the hypertensive group (33±3% vs 21±2%, P 〈 0.05). The data indicate that phenylephrine-induced hypertension instituted 2 h after MCAO does not aggravate edema in the ischemic core, that it improves edema in the periphery of the ischemic territory, and that it reduces the area of histochemical neuronal dysfunction.
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  • 4
    ISSN: 1432-0851
    Keywords: TIL ; Melanoma ; Histopathology ; Imaging ; Lymphocytic infiltrate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Tumor-infiltrating lymphocytes (TIL) from a wide range of human and murine tumors can be expanded in vitro using interleukin-2 (IL-2). These TIL are cytolytic T lymphocytes with in vivo and in vitro antitumor activity in mice and in humans. TIL from human melanoma can recognize autologous tumor in an MHC-restricted fashion, localize in vivo after111In labeling, and mediate regression of large metastatic deposits. Although studied extensively in vitro, less is known in vivo about TIL activity associated with tumor regression. This study was undertaken, in association with a study of TIL localization, to investigate mechanisms of TIL action by evaluating histopathological changes that occur at the tumor site during TIL administration. A total of 106 pre- and post-treatment pathological specimens from 25 patients enrolled in phase II TIL treatment and111In-TIL imaging protocols were examined blindly by a single pathologist. Histological subtype, lymphocytic infiltration, melanin content, vascularity, and necrosis were documented for each tumor specimen. Average baseline and post-treatment parameters were compared. Any significant changes were evaluated for correlation with clinical response and111In-TIL localization to tumor. Melanin content and vascularity of the tumor did not change as a result of therapy or correlate with either response or TIL localization. However, both increased lymphocytic infiltration and tumor necrosis were present after TIL administration (P=0.044 and 0.032 respectively). Furthermore, increases in lymphocytic infiltration correlated with tumor imaging using111In-TIL, and with the percentage of111In-labeled injectate present per gram of tumor specimen (P=0.036 and 0.0041 respectively). This suggests that TIL either account for the increased lymphocytes directly, or localize to tumor and recruit endogenous lymphocytes. We were unable to demonstrate any pretreatment histopathological predictors of response or variables that significantly correlated with subsequent clinical response, although peak and average values of necrosis were higher in responding patients compared to non-responding patients.
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  • 5
    ISSN: 1432-0851
    Keywords: Key words: TIL – Melanoma – Histopathology – Imaging – Lymphocytic infiltrate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Tumor-infiltrating lymphocytes (TIL) from a wide range of human and murine tumors can be expanded in vitro using interleukin-2 (IL-2). These TIL are cytolytic T lymphocytes with in vivo and in vitro antitumor activity in mice and in humans. TIL from human melanoma can recognize autologous tumor in an MHC-restricted fashion, localize in vivo after 111In 2labeling, and mediate regression of large metastatic deposits. Although studied extensively in vitro, less is known in vivo about TIL activity associated with tumor regression. This study was undertaken, in association with a study of TIL localization, to investigate mechanisms of TIL action by evaluating histopathological changes that occur at the tumor site during TIL administration. A total of 106 pre- and post-treatment pathological specimens from 25 patients enrolled in phase II TIL treatment and 111In-TIL imaging protocols were examined blindly by a single pathologist. Histological subtype, lymphocytic infiltration, melanin content, vascularity, and necrosis were documented for each tumor specimen. Average baseline and post-treatment parameters were compared. Any significant changes were evaluated for correlation with clinical response and 111In-TIL localization to tumor. Melanin content and vascularity of the tumor did not change as a result of therapy or correlate with either response or TIL localization. However, both increased lymphocytic infiltration and tumor necrosis were present after TIL administration (P = 0.044 and 0.032 respectively). Furthermore, increases in lymphocytic infiltration correlated with tumor imaging using 111In-TIL, and with the percentage of 111In-labeled injectate present per gram of tumor specimen (P = 0.036 and 0.0041 respectively). This suggests that TIL either account for the increased lymphocytes directly, or localize to tumor and recruit endogenous lymphocytes. We were unable to demonstrate any pretreatment histopathological predictors of response or variables that significantly correlated with subsequent clinical response, although peak and average values of necrosis were higher in responding patients compared to non-responding patients.
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  • 6
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 164 (1949), S. 669-669 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] WE have been interested in devising a simple method for determining the depth to which roots or underground stems of perennial weeds have been killed following the application of a poison to their tops, and have obtained useful results by means of a simple electrical method. The equipment ...
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  • 7
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The appearance of biotypes of the annual grass weed black-grass (Alopecurus myosuroides L. Huds), which are resistant to certain graminicides, is the most significant example of acquired resistance to herbicides seen so far in European agriculture. An investigation was perfomed into the basis of the specific cross-resistance to cyclohexanedione (CHD) and aryloxyphenoxypropionoic acid (AOPP) herbicides in the ‘Notts A1’ population of A. myosuroides, which survived treatment of fields with recommended rates of AOPP herbicides. In comparison with the wild-type ‘Rothamsted’ population, the resistant biotype showed over 100-fold resistance to these herbicides in a hydroponic growth system. Biosynthesis of fatty acids and activity of crude extracts of acetyl-CoA carboxylase (ACCase) were commensurately less sensitive to these herbicides in Notts A1 compared with the Rothamsted biotype. These data are consistent with the hypothesis that the highly resistant population has arisen through selection of a mutant ACCase which is much less sensitive to the AOPP and CHD graminicides. Rapidly growing cell suspension cultures established from the Notts A1 population also showed high resistance indices for CHD or AOPP herbicides compared with cultures from the Rothamsted biotype. Fatty acid biosynthesis and ACCase activity in the cell suspensions were similarly sensitive towards the graminicides to those in the foliar tissue counterparts of the resistant and sensitive populations. Moreover, purification of the main (chloroplast) isoform of acetyl-CoA carboxylase showed that this enzyme from the Notts A1 population was over 200-fold less sensitive towards the AOPP herbicide, quizalofop, than the equivalent isoform from the Rothamsted population. These data again fully supported the proposal that resistance in the Notts biotype is due to an insensitive acetyl-CoA carboxylase isoform. Overall, cell suspensions were also demonstrated to be excellent tools for further investigation of the molecular basis of the high level herbicide resistance which is prone to occur in A. myosuroides.
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  • 8
    ISSN: 1573-0832
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Pregnant sheep inoculated withAspergillus fumigatus conidia developed precipitating and latex agglutinating antibodies to mycelial antigens. The titres of these tended to be higher in those animals developing placental or fetal infection than in those which did not. The concentrations of total serum proteins and of albumin,α, β andγ globulins did not show any consistent changes which could be related to abortion or placental infection. Lymphocyte transformation tests on whole blood showed significant responses to phytohaemagglutinin but not toA. fumigatus antigens.
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  • 9
    Publication Date: 2018-07-06
    Description: Author(s): K. Poder, M. Tamburini, G. Sarri, A. Di Piazza, S. Kuschel, C. D. Baird, K. Behm, S. Bohlen, J. M. Cole, D. J. Corvan, M. Duff, E. Gerstmayr, C. H. Keitel, K. Krushelnick, S. P. D. Mangles, P. McKenna, C. D. Murphy, Z. Najmudin, C. P. Ridgers, G. M. Samarin, D. R. Symes, A. G. R. Thomas, J. Warwick, and M. Zepf Substantial energy loss in an electron beam passing through a high-intensity laser provides clear evidence of the radiation reaction, shedding light on how electrons interact with extreme electromagnetic fields. [Phys. Rev. X 8, 031004] Published Thu Jul 05, 2018
    Electronic ISSN: 2160-3308
    Topics: Physics
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