Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 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.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 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.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0428
    Keywords: Microencapsulation ; interleukin-1β ; pancreatic islets ; biocompatibility ; transplantation ; diabetes mellitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Alginate-polylysine microencapsulation has been proposed as a method of protecting transplanted pancreatic islets against immunological attack. Using this technique, prolonged graft survival has been reported in some diabetic animals. However, in the spontaneously diabetic insulindependent BB/E rat we found that intraperitoneal implantation of microencapsulated islets had only a short-lived effect on hyperglycaemia. Recovered microcapsules (both those implanted empty and containing islets) were surrounded by a foreign body type cellular overgrowth and, although many capsules remained intact, encapsulated islets were observed to be disintegrating. Loss of Beta cells was confirmed by immunohistology. Various polymer materials used in artificial membranes have been shown to activate macrophages involved in foreign body reactions and induce synthesis of interleukin-1β, a known Beta-cell toxin. Reduced secretion of insulin and progressive islet damage (indicated by a significant reduction in residual islet insulin and DNA content) were demonstrated when microencapsulated islets were incubated with interleukin-1βin vitro for 9 days. Similar effects were seen following exposure to a combination of gamma interferon and alpha tumour necrosis factor. Successful use of microencapsulation in islet transplantation depends upon the development of biocompatible membranes. The exclusion of smaller molecules, such as cytokines, which may be involved in foreign body mediated damage and microencapsulated islet graft rejection, could also be important.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1432-0428
    Keywords: Key words IDDM, biopterin, pre-diabetes, nitric oxide, macrophages, insulitis.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Tetrahydrobiopterin (BH4) is a pteridine product which is released by rodent macrophages on activation by cytokines. We have used serial pancreatic biopsy, and measurement of serum biopterin at 30, 60, 90 and 120 days in the BB/S rat to relate histological change to macrophage activation during the course of pre-diabetes. Using immunohistochemistry, and an arbitrary scoring system read blind and standardised against day 30, we found that pancreatic MHC class I, MHC class II and infiltrating macrophage staining were upregulated in the BB/S diabetes-prone rats (n=17) at day 60, markedly so at day 90, and less so at day 120. Staining for resident pancreatic macrophages remained unchanged throughout in diabetes prone, diabetes resistant and Wistar (n=28) control animals. Serum biopterin fell progressively and identically with age in BB diabetes resistant rats (n=11) and Wistar controls. No change in weight gain or biopterin levels was observed in the biopsied animals. Mean serum biopterin levels in diabetes prone rats (of which 13 of 17 became diabetic at median 85 days) were the same as in diabetes resistant and Wistar rats at days 30, 60 and 120, but showed a striking and highly significant elevation (p〈0.001) at day 90. Although macrophages infiltrate the islet early in pre-diabetes, the timing of their activation is unknown. The rise in biopterin we observed is a potentially important immunological event which occurred late in the progression of pre-diabetes. This acute terminal event has not been reported previously, and may modify current concepts concerning the tempo of cell destruction during pre-diabetes. [Diabetologia (1994) 37: 466–470]
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    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.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    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.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    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.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] We prepared KRP(85/95) monoclonal immunoglobulin Gs against the 95K (antibody K2.1) and 85K subunits (antibodies K2.2, K2.3, K2.4) from mice immunized with highly purified KRP(85/95) (Fig. \o). In support of the hypothesis that the 115K, 95K and 85K polypeptides of KRP(85/95) are ...
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-4838
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Technology
    Notes: Tolerance to alginate-polylysine-alginate microcapsules implanted into the peritoneal cavity was compared in the Wistar Furth rat and the BB/E (Wistar-derived) spontaneously diabetic rat. A marked foreign-body type reaction was observed in the BB/E rat in both diabetic and non-diabetic animals. In contrast, little or no reaction was observed in the Wistar Furth rat. Implantation under the kidney capsule, an immunologically privileged site, did not protect the microcapsules. Blocking the surface charge of the microcapsule by coating with tolylene diisocyanate also failed to modify the reaction. Coating with a water-insoluble lacquer (Eudragit RL) resulted in dense capsule overgrowth. Thus tolerance to alginate-polylysine-alginate microcapsules appears to be dependent upon the recipient animal strain and this may explain some of the discrepancies in function observed in different animal models when this system has been used to encapsulate pancreatic islets for a bioartificial pancreas. The tissue reaction does not seem to be affected by clinical diabetic status although abnormal immunological responses in animals with a tendency to spontaneous diabetes could be important. Attempts to reduce the reaction to the capsules in the BB/E rat strain by modifying the membrane were unsuccessful.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1572-8854
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The emphasis of computational chemistry has traditionally been slanted toward the study of isolated organic systems, and in particular toward methods of drug design. The requirements for the study of materials are different, we are often concerned with metal containing species and properties that arise from interactions between unit molecules in the solid state. We have developedcrystal, a molecular modeling environment that provides both the capability to perform calculations on metal complexes, and an array of visualization tools to aid in the design of solid-state systems.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...