scholarly journals Direct immunofluorescence as a low-budget method for brain tissue inspection in standardization of neuroborreliosis animal model in NMRI mice

2021 ◽  
Vol 18 (1) ◽  
pp. 3-7
Author(s):  
Selena Đurić ◽  
Verica Simin ◽  
Pavle Banović

Objective. To test if the direct immunofluorescence can be used for the detection of Borrelia afzelii in brain tissue during the standardization of the animal model of neuroborreliosis in NMRI mice. Methods. The study was performed on 15 mice of NMRI strain. All mice were subcutaneously inoculated with 100 ml of BSK-H medium containing the local isolate of Borrelia afzelii. Animals were sacrificed after inoculation at III (n = 4), IV (n = 6) and V (n = 5) weeks, by cervical dislocation. In the sampled brains of mice, the presence of Borrelia was detected by direct immunofluorescence (DIF) and chain polymerization reaction (PCR). Results. The first brain tested positive for Borrelia three weeks after the inoculation. The bacteria were detected in 1 out of 4 brains (25%). After that, there was a growth in the percentage of positive results. The data showed that 3 out of 6 brains (50%) were found positive on Borrelia presence by the end of the fourth week. Whereas, in 3 out of 5 brains (60%) Borrelia was detected five weeks following the inoculation. Conclusion. According to the preliminary results, direct immunofluorescence appeared to be a practical, low budget method for following the kinetics of neuro-infection. NMRI mice could be considered as an adequate animal model for neuroborreliosis. Thus, more research is needed on the topics of infection kinetics for the period after fifth week post inoculation, as well as sensitivity and specificity of direct immunofluorescence.

2021 ◽  
Vol 165 ◽  
pp. 28
Author(s):  
Ana Ledo ◽  
Eliana Fernandes ◽  
João Laranjinha ◽  
Rui M. Barbosa

2021 ◽  
Author(s):  
Seth A. Hawks ◽  
Aaron J. Prussin ◽  
Sarah C. Kuchinsky ◽  
Jin Pan ◽  
Linsey C. Marr ◽  
...  

Respiratory viruses such as SARS-CoV-2 are transmitted in respiratory droplets and aerosols, which are released during talking, breathing, coughing, and sneezing. Non-contact transmission of SARS-CoV-2 has been demonstrated, suggesting transmission in aerosols. Here we demonstrate that golden Syrian hamsters emit infectious SARS-CoV-2 in aerosols, prior to and concurrent with the onset of mild clinical signs of disease. The emission rate is 25 infectious virions/hour on days 1 and 2 post-inoculation, with viral RNA levels 200-fold higher than infectious virus in aerosols. Female hamsters have delayed kinetics of viral shedding in aerosols compared to male hamsters. The majority of virus is contained within aerosols <8 microns in size. Thus, we provide direct evidence that, in hamsters, SARS-CoV-2 is an airborne virus.


2013 ◽  
Vol 8 (1) ◽  
pp. 4 ◽  
Author(s):  
Takuya Hayashi ◽  
Masamitsu Shimazawa ◽  
Hiroshi Watabe ◽  
Takayuki Ose ◽  
Yuta Inokuchi ◽  
...  
Keyword(s):  

Author(s):  
Liang Zhu ◽  
Axel J. Rosengart

Inducing hypothermia to brain tissue after brain ischemia or head injury has been demonstrated beneficial to the patients. Clinical studies have shown that even 1 or 2°C temperature reduction in brain tissue can be protective [Dietrich 1992]. On the contrary, fever-induced hyperthermia can worsen the neurological outcome in an animal model after cerebral ischemia. It is of clinical importance to understand the temperature distribution in brain during brain hypothermia.


1960 ◽  
Vol 33 (3) ◽  
pp. 696-698
Author(s):  
S. E. Bresler ◽  
M. I. Mosevitskiĭ

Abstract For the study of the mechanism of polymerization by means of complexes of aluminum organic compounds with titanium chlorides, data on the kinetics of polymerization is of great interest. Up to the present time, the rate of polymerization of propylene has been studied but the interpretation of the kinetic data is difficult because the polymer, which is practically insoluble in the reaction medium, entraps the catalyst resulting in a rate of reaction which is dependent on the diffusion of monomer through the polymer to the active sites. In this work the polymerization of isoprene, which yields polymers soluble in the monomer, in saturated hydrocarbons and in benzene, was studied. The rate of the polymerization reaction was measured by the thermal effect in a calorimeter consisting of a 3.5 1. Dewar flask, with a lid, immersed in a thermostated air bath maintained at approximately the temperature of the reaction. Low viscosity spindle oil, heated to the temperature of the reaction (about 32°), served as the calorimeter fluid. The ampoule holder extended outside of the calorimeter and was connected to a shaking apparatus. The ampoule was divided by a thin partition into two sections each holding 45–50 cc. Into one section previously purified monomers and solvent were distilled. The other section was filled with catalyst components from a Shlenk container. The change in temperature of the calorimeter was determined with a Beckman thermometer with an accuracy of 0.01 °. When the temperature of the calorimeter containing the ampoule remained constant to within 0.01–0.02° for 30–40 minutes, the shaking apparatus was connected and the partition was broken with a striker. Intensive shaking was continued during the entire experiment resulting in mixing of the reaction mixture and of the calorimeter fluid. The rate of reaction was determined by the rate of heat evolution ; in other words, by the temperature rise in the calorimeter. For a rise of 0.1–0.5° the reaction conditions remained practically isothermal. This rise permits the kinetics of the reaction to be observed with sufficient accuracy. Adiabaticity of the calorimeter and the effect of mechanical heat were controlled in separate experiments.


1980 ◽  
Vol 28 (9) ◽  
pp. 1029-1031 ◽  
Author(s):  
K Schauenstein ◽  
G Böck ◽  
G Wick

The fluorescence kinetics of fluorescein isothiocyanate (FITC)-antibody conjugates during short (0.01 sec) laser excitations were analyzed for possible information about the immunological specificity of binding to antigenic substrates in direct immunofluorescence assays with antigen-coated Sephadex beads. First results of these investigations suggest marked differences in the bleaching characteristics of specifically and nonspecifically bound FITC conjugates: FITC-anti-bovine serum albumin (BSA) and FITC-anti-rabbit immunoglobulin (Ig) were found to fade significantly more slowly when bound to the respective homologous antigen (anti-BSA to BSA, and anti-rabbit Ig to rabbit Ig) as compared to nonspecifically adherent anti-BSA to rabbit Ig, and anti-rabbit Ig to BSA. Possible implications of these data for discrimination of nonspecific staining in immunofluorescence are discussed.


2017 ◽  
Vol 262 ◽  
pp. 668-672 ◽  
Author(s):  
Emmanuel Ngoma ◽  
Kathija Shaik ◽  
Danilo Borja ◽  
Mariette Smart ◽  
Jay Hyun Park ◽  
...  

The aim of this study was to investigate the microbial colonization and arsenic leaching kinetics of South Korean mine tailings containing arsenopyrite at fixed temperatures (20°C, 30°C and 45°C) and at ramped up temperatures (25 to 45°C, with a 2°C daily increase). The experiments were conducted in a packed bed of inert granite pebbles coated with the tailings material and leached with a mesophilic culture dominated by Acidithiobacillus caldus (56%), a lesser percentage of Leptospirillum ferriphilum (29%) and Archaea (15%), using 1 g/L ferrous-enriched 0K medium. The ramped-up temperature experiment was conducted in triplicate and columns were sacrificed after different leach periods to study the evolution of microbial species dominating the colonization. The leaching performance was evaluated using the arsenic released into solution, the iron oxidation rates, the pH and the redox potential. The microbial speciation of the culture attached to the solids during the leach experiment was determined upon completion of each experiment. A steady arsenic solubilisation of between 94 and 97% was observed among the various column experiment after 88 days post inoculation. Microbial speciation performed following the leaching of the mineral indicated a shift of microbial communities in the columns when compared to the initial inoculum.


e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Ali Pourjavadi ◽  
Mohammad Sadeghi ◽  
Mohammad Mahmodi Hashemi ◽  
Hossein Hosseinzadeh

AbstractIn this article, we synthesize a novel gelatin-based superabsorbent hydrogel via graft copolymerization of mixtures of acrylic acid (AA) and acrylamide (AAm) onto gelatin backbones. The polymerization reaction was carried out in an aqueous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N'-methylene bisacrylamide (MBA) as a crosslinker. The hydrogel structures were confirmed by FTIR spectroscopy. The effect of grafting variables, i.e. concentration of MBA and APS, AA/AAm weight ratio, and reaction time and temperature, was systematically optimized to achieve a hydrogel with swelling capacity as high as possible. The swelling behavior of these absorbent polymers was also investigated in various salt solutions. Results indicated that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. Furthermore, the swelling of superabsorbing hydrogels was examined in solutions with pH values ranging between 1.0 and 13.0. It showed a reversible pH-responsive behavior at pHs 2.0 and 7.0. This on-off switching behavior makes the synthesized hydrogels an excellent candidate for controlled delivery of bioactive agents. Finally, the swelling kinetics of the synthesized hydrogels with various particle sizes was preliminarily investigated.


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