Interleukin 6 (IL-6) is a cytokine involved in many aspects of the acute phase and immune responses. Cloning of rat IL-6 cDNA into the pET-21d expression plasmid under control of a bacteriophage T7 ...RNA polymerase promoter system allowed isopropylthio-galactopyranoside (IPTG)-inducible production of recombinant rat IL-6 in Escherichia coli. The cloning, expression and purification of rat IL-6 is described. In this expression system, rat IL-6 was produced in insoluble inclusion bodies. The protein was solubilized in 6 M guanidine hydrochloride and refolded in a glutathione redox system. Refolded rat IL-6 was purified to homogeneity using anion-exchange chromatography on SP-Trisacryl. The purified recombinant rat IL-6 had a molecular mass of 21 756.38+/-0.25 Da, which is within 0.01% of the predicted value, taking into account cleavage of the N-terminal methionine residue and the formation of two disulfide bridges. Recombinant rat IL-6 was 2-3-fold more bioactive than the human standard preparation in the B9 hybridoma bioassay. Purified rat IL-6 was used to raise polyclonal antibodies in sheep and these reagents were used to develop a novel rat IL-6 enzyme-linked immunosorbent assay (ELISA). The ELISA is sensitive to 10 pg/ml and has been shown to detect IL-6 in plasma from rats injected with lipopolysaccharide (LPS).
To explore the histological, electrophysiological, radiological, and behavioral effects of radiosurgery using a new model of proton beam radiosurgery (PBR) of the rodent hippocampus.
Forty-one rats ...underwent PBR of the right hippocampus with nominal doses of 5 to 130 cobalt Gray equivalents (CGE). Three control animals were untreated. Three months after PBR, 41 animals were evaluated with the Morris water maze, 23 with T2-weighted magnetic resonance imaging, and 22 with intrahippocampal microelectrode recordings. Animals that were studied physiologically were killed, and their brains were examined with Nissl staining and immunocytochemical staining for glutamic acid decarboxylase, heat shock protein 72 (HSP-72), parvalbumin, calmodulin, calretinin, calbindin, and somatostatin.
Ninety and 130 CGE resulted in decreased performance in the Morris water maze, increased signal on T2-weighted magnetic resonance imaging, diminished granule cell field potentials, and tissue necrosis, which was restricted to the irradiated side. These doses also resulted in ipsilateral up-regulation of calbindin and HSP-72. Parvalbumin was down-regulated at 130 CGE. The 30 and 60 CGE animals displayed a marked increase in HSP-72 staining on the irradiated side but no demonstrable cell loss. No asymmetries were noted in somatostatin, calretinin, and glutamic acid decarboxylase staining. Normal physiology was found in rats receiving up to 60 CGE.
This study expands our understanding of the effects of radiosurgery on the mammalian brain. Three months after PBR, the irradiated rat hippocampus demonstrates necrosis at 90 CGE, but not at 60 CGE, with associated abnormalities in magnetic resonance imaging, physiology, and memory testing. HSP-72 was up-regulated at nonnecrotic doses.
After major surgery, analgesia with opioids can cause obstructive apnea and intermittent hypoxemia, probably from loss of upper airway control. Since this resembles the obstructive sleep apnea ...syndrome, we tested the possibility that nasal continuous positive airway pressure (nCPAP) would reduce episodes of reduced oxygen saturation and sleep disruption. Because oxygen therapy is frequent after surgery, we also assessed the effect of oxygen on sleep disruption.
We recruited 48 patients about to have major abdominal surgery. We present data for 34 patients: 27 who received patient-controlled intravenous morphine and 7 who received epidural opioid. Treatment was randomized to either nCPAP or conventional therapy with an oxygen mask. Alternate periods of administration of air and 35% oxygen were used in both groups. If the oxygen saturation as measured by pulse oximetry was consistently <90% on air, the patient was withdrawn from the study. We measured sleep, arousals, oxygenation, episodes of desaturation, and disturbances of respiration. Values are given as median and quartiles.
The median proportion of time awake was 65% (45-79%) among control patients and 74% (55-87%) among those undergoing nCPAP. Oxygen administration did not affect the sleep pattern. The median frequency of arousals per hour of sleep was very similar in each group: during air breathing from nCPAP, 125 (76-187), and during air breathing by mask, 116 (84-187). Oxygen therapy had no effect. Oxygenation and hypoxemic events were not improved by nCPAP. Oxygen therapy improved oxygenation and reduced but did not eliminate episodes of desaturation.
Nasal CPAP does not improve sleep and oxygenation or reduce hypoxemic events in the first night after major abdominal surgery.
To study the hyperacute histological and immunohistochemical effects of stereotactic proton beam irradiation of the rat hippocampus.
Nine rats underwent proton beam radiosurgery of one hippocampus ...with nominal doses of cobalt-2, -12, and -60 Gray equivalents (n = 3 each). Control animals (n = 3) were not irradiated. Animals were killed 5 hours after irradiation and brain sections were stained for Nissl, silver degeneration, deoxyribonucleic acid (DNA) fragmentation (DNAF), and the activated form of two mitogen-activated protein kinases (MAPKs), phospho-Erk1/2 (P-Erk1/2) and p38. Stained cells in the hippocampus expressing DNAF and/or P-Erk1/2 were counted. Confocal microscopy with double immunofluorescent staining was used to examine cellular colocalization of DNAF and P-Erk1/2.
Both DNAF and P-Erk1/2 showed quantitative dose-dependent increases in staining in the targeted hippocampus compared with the contralateral side and controls. This finding was restricted to the subgranular proliferative zone of the hippocampus. Both markers also were up-regulated on the contralateral side when compared with controls in a dose-dependent fashion. Simultaneous staining for DNAF and P-Erk1/2 was found in fewer than half of all cells. p38 was unchanged compared with controls. Although Nissl staining appeared normal, silver stain confirmed dose-dependent cellular degeneration.
DNAF, a marker of cell death, was present in rat hippocampi within 5 hours of delivery of cobalt-2 Gray equivalents stereotactically focused irradiation, suggesting that even low-dose radiosurgery has hyperacute neurotoxic effects. Activated mitogen-activated protein kinase was incompletely colocalized with DNAF, suggesting that activation of this cascade is neither necessary nor sufficient to initiate acute cell death after irradiation.
Tumour necrosis factor-alpha is a pro-inflammatory cytokine involved in many aspects of acute phase and immune responses. Species specificity in the biological action and receptor binding of ...TNF-alpha make it desirable to use homologous reagents in experimental models, both in vivo and in vitro. As the rat is the model of choice in many investigations on fever, trauma and pathology, there is a need for specific rat reagents. In this paper, we describe the production of recombinant rat TNF-alpha in milligram quantities, using a methylotrophic yeast expression system, Pichia pastoris. Recombinant TNF-alpha was produced intracellularly in a soluble form, cells were lysed and the protein purified by ammonium sulphate precipitation, Sephadex G75 fractionation and finally, ion-exchange chromatography. The purified recombinant rat TNF-alpha had a molecular mass of 17401.38 +/- 0.38 Da, which is within 1 Da of the value predicted by the sequence data, taking into account N-acetylation of the initial methionine residue and a single disulphide bridge between amino acids 70 and 101. Recombinant rat TNF-alpha was shown to be 20 x fold more biologically active in the WEHI cytotoxicity assay, than the human standard preparation. Polyclonal antibodies were raised against purified recombinant rat TNF-alpha, these reagents were used to develop a novel enzyme-linked immunosorbant assay (ELISA). The ELISA was sensitive to 10 pg.ml- 1 rat TNF-alpha and was specific for TNF-alpha, showing no cross-reactivity with rat IL-1alpha, rat IL-1beta, rat IL-1Ra or rat IL-6. The ELISA was used to measure TNF-alpha in the plasma of rats injected with bacterial endotoxin and in cultures of rat white blood cells. The ELISA was shown to be a robust method suitable for use in assaying samples generated in both in vivo or in vitro experiments.
To determine pharmacokinetics of single and multiple doses of rimantadine hydrochloride in horses and to evaluate prophylactic efficacy of rimantadine in influenza virus-infected horses.
5 clinically ...normal horses and 8 horses seronegative to influenza A.
Horses were given rimantadine (7 mg/kg of body weight, i.v., once; 15 mg/kg, p.o., once; 30 mg/kg, p.o., once; and 30 mg/kg, p.o., q 12 h for 4 days) to determine disposition kinetics. Efficacy in induced infections was determined in horses seronegative to influenza virus A2. Rimantadine was administered (30 mg/kg, p.o., q 12 h for 7 days) beginning 12 hours before challenge-exposure to the virus.
Estimated mean peak plasma concentration of rimantadine after i.v. administration was 2.0 micrograms/ml, volume of distribution (mean +/- SD) at steady-state (Vdss) was 7.1 +/- 1.7 L/kg, plasma clearance after i.v. administration was 51 +/- 7 ml/min/kg, and beta-phase half-life was 2.0 +/- 0.4 hours. Oral administration of 15 mg of rimantadine/kg yielded peak plasma concentrations of < 50 ng/ml after 3 hours; a single oral administration of 30 mg/kg yielded mean peak plasma concentrations of 500 ng/ml with mean bioavailability (F) of 25%, beta-phase half-life of 2.2 +/- 0.3 hours, and clearance of 340 +/- 255 ml/min/kg. Multiple doses of rimantadine provided steady-state concentrations in plasma with peak and trough concentrations (mean +/- SEM) of 811 +/- 97 and 161 +/- 12 ng/ml, respectively. Rimantadine used prophylactically for induced influenza virus A2 infection was associated with significant decreases in rectal temperature and lung sounds.
Oral administration of rimantadine to horses can safely ameliorate clinical signs of influenza virus infection.
Sammendrag Med 2022-oppsetningen av Sancthansnatten ved Ibsen Museum & Teater i Oslo som utgangspunkt stiller denne artikkelen spørsmål ved to seiglivede myter knyttet til Henrik Ibsens forhold til ...den populære teaterkunsten som dominerte Europa på 1850-tallet: at Catilina var det første «seriøse» norske skuespillet på sju år da det kom ut i 1850, og at Ibsen tok avstand fra «useriøse» scenetekster skrevet av utenlandske dramatikere som Eugène Scribe. Målet er å kaste et kritisk blikk på den litteraturhistoriske fremstillingen av den norske teaterkulturen og argumentere for en åpnere tilnærming til scenetekstene Ibsen forholdt seg til mens han arbeidet i teatret. Dette fører til nye innsikter om hvordan vaudeville-sjangeren kan ha påvirket Ibsens forhold til romantisk idealisme.
PDF
