EFFECT OF REDUCING AGENTS ON THE VIABILITY OF EQUINE ENCEPHALOMYELITIS VIRUS (EASTERN TYPE)

1946 ◽  
Vol 24e (4) ◽  
pp. 119-133
Author(s):  
N. A. Labzoffsky
Keyword(s):  
Sodium Chloride ◽  
Reducing Agents ◽  
Present Communication ◽  
Virus Suspension ◽  
Experimental Conditions ◽  
Cysteine Hydrochloride ◽  
Wide Range ◽  
Encephalomyelitis Virus ◽  
Ph Range

The present communication deals with the effect of reducing agents (cysteine hydrochloride, sodium thioglycollate, and sodium formaldehyde sulphoxylate) on the viability of equine encephalomyelitis virus (Eastern type). Cysteine hydrochloride was found to be a valuable reagent in in vitro studies of equine encephalomyelitis virus, because it greatly retards loss of infectivity of the virus under experimental conditions. It was observed that a virus suspension containing cysteine hydrochloride (1:1000) remained infective after exposure to 37 °C. for 14 days, although the guinea-pig titre was reduced from 1:108 to 1:102. The same reduction in the titre of virus suspended in buffered 0.85% sodium chloride solution occurred after exposure to 37 °C. for 120 hr. only, and in unbuffered 0.85% sodium chloride after 24 hr. exposure. Further, equine encephalomyelitis virus, in the presence of cysteine hydrochloride, retains its infectivity without demonstrable loss, over a pH range between 4.8 and 8.2 for 48 hr. at 37 °C. The titre of equine encephalomyelitis virus is maintained at 37 °C. for 48 hr. in a rather wide range of Eh, created with the aid of cysteine hydrochloride, at least in the range between − 0.151 and + 0.02 volts. On the other hand, addition of sodium formaldehyde sulphoxylate or sodium thioglycollate to a suspension of equine encephalomyelitis virus does not retard loss of infectivity of the virus. These reagents, therefore, are not suitable for the conservation of infectivity of the virus in vitro.

scholarly journals Amyloid Beta: Multiple Mechanisms of Toxicity and Only Some Protective Effects?

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Paul Carrillo-Mora ◽  
Rogelio Luna ◽  
Laura Colín-Barenque
Keyword(s):  
Amyloid Beta ◽  
Protective Effects ◽  
Protective Mechanisms ◽  
Experimental Conditions ◽  
Mechanisms Of Toxicity ◽  
Mitochondrial Alterations ◽  
Physiological Properties ◽  
Wide Range

Amyloid beta (Aβ) is a peptide of 39–43 amino acids found in large amounts and forming deposits in the brain tissue of patients with Alzheimer’s disease (AD). For this reason, it has been implicated in the pathophysiology of damage observed in this type of dementia. However, the role of Aβin the pathophysiology of AD is not yet precisely understood. Aβhas been experimentally shown to have a wide range of toxic mechanismsin vivoandin vitro, such as excitotoxicity, mitochondrial alterations, synaptic dysfunction, altered calcium homeostasis, oxidative stress, and so forth. In contrast, Aβhas also shown some interesting neuroprotective and physiological properties under certain experimental conditions, suggesting that both physiological and pathological roles of Aβmay depend on several factors. In this paper, we reviewed both toxic and protective mechanisms of Aβto further explore what their potential roles could be in the pathophysiology of AD. The complete understanding of such apparently opposed effects will also be an important guide for the therapeutic efforts coming in the future.

scholarly journals Mycobacterial Esx-3 Requires Multiple Components for Iron Acquisition

mBio ◽  
2014 ◽  
Vol 5 (3) ◽  
Author(s):  
M. Sloan Siegrist ◽  
Magnus Steigedal ◽  
Rushdy Ahmad ◽  
Alka Mehra ◽  
Marte S. Dragset ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Iron Acquisition ◽  
Multiple Reaction Monitoring ◽  
Protein Export ◽  
Secretion Systems ◽  
Experimental Conditions ◽  
Content Type ◽  
Type Vii Secretion ◽  
Wide Range

ABSTRACT The type VII secretion systems are conserved across mycobacterial species and in many Gram-positive bacteria. While the well-characterized Esx-1 pathway is required for the virulence of pathogenic mycobacteria and conjugation in the model organism Mycobacterium smegmatis, Esx-3 contributes to mycobactin-mediated iron acquisition in these bacteria. Here we show that several Esx-3 components are individually required for function under low-iron conditions but that at least one, the membrane-bound protease MycP3 of M. smegmatis, is partially expendable. All of the esx-3 mutants tested, including the ΔmycP 3ms mutant, failed to export the native Esx-3 substrates EsxH ms and EsxG ms to quantifiable levels, as determined by targeted mass spectrometry. Although we were able to restore low-iron growth to the esx-3 mutants by genetic complementation, we found a wide range of complementation levels for protein export. Indeed, minute quantities of extracellular EsxH ms and EsxG ms were sufficient for iron acquisition under our experimental conditions. The apparent separation of Esx-3 function in iron acquisition from robust EsxG ms and EsxH ms secretion in the ΔmycP 3ms mutant and in some of the complemented esx-3 mutants compels reexamination of the structure-function relationships for type VII secretion systems. IMPORTANCE Mycobacteria have several paralogous type VII secretion systems, Esx-1 through Esx-5. Whereas Esx-1 is required for pathogenic mycobacteria to grow within an infected host, Esx-3 is essential for growth in vitro. We and others have shown that Esx-3 is required for siderophore-mediated iron acquisition. In this work, we identify individual Esx-3 components that contribute to this process. As in the Esx-1 system, most mutations that abolish Esx-3 protein export also disrupt its function. Unexpectedly, however, ultrasensitive quantitation of Esx-3 secretion by multiple-reaction-monitoring mass spectrometry (MRM-MS) revealed that very low levels of export were sufficient for iron acquisition under similar conditions. Although protein export clearly contributes to type VII function, the relationship is not absolute.

scholarly journals Electrical impulse characterization along actin filaments in pathological conditions

2021 ◽  
Author(s):  
Christian Hunley ◽  
Md Mohsin ◽  
Marcelo Marucho
Keyword(s):  
Actin Filaments ◽  
High Performance ◽  
Original Research ◽  
Experimental Conditions ◽  
Theoretical Formulation ◽  
Pathological Conditions ◽  
Wide Range ◽  
Biological Environment ◽  
Electrical Impulses

We present an interactive Mathematica notebook that characterizes the electrical impulses along actin filaments in both muscle and non-muscle cells for a wide range of physiological and pathological conditions. The program is based on a multi-scale (atomic → monomer → filament) approach capable of accounting for the atomistic details of a protein molecular structure, its biological environment, and their impact on the travel distance, velocity, and attenuation of monovalent ionic wave packets propagating along microfilaments. The interactive component allows investigators to conduct original research by choosing the experimental conditions (intracellular Vs in vitro), nucleotide state (ATP Vs ADP), actin isoform (alpha, gamma, beta, and muscle or non-muscle cell), as well as, a conformation model that covers a variety of mutants and wild-type (the control) actin filament. The simplicity of the theoretical formulation and the high performance of the Mathematica software enable the analysis of multiple conditions without computational restrictions. These studies may provide an unprecedented molecular understanding of why and how age, inheritance, and disease conditions induce dysfunctions in the biophysical mechanisms underlying the propagation of electrical signals along actin filaments.

scholarly journals Separation of tungsten and rhenium on alumina

2004 ◽  
Vol 69 (8-9) ◽  
pp. 683-688 ◽  
Author(s):  
Jurij Vucina ◽  
Dagoljub Lukic ◽  
Milovan Stoiljkovic
Keyword(s):  
Nitric Acid ◽  
Sodium Chloride ◽  
Aqueous Phase ◽  
Aqueous Media ◽  
Distribution Coefficients ◽  
Experimental Conditions ◽  
Efficient Separation ◽  
Separation Factors ◽  
Ph Range

The conditions for the efficient separation of tungsten(VI) and rhenium (VII) on alumina were established. The distribution coefficients K d for tungstate and perrhenate anions, as well as the separation factors ?(? = KdWO42-/Kd ReO4-) were determined using hydrochloric or nitric acid as the aqueous media. Asolution of sodium chloride in the pH range 2?6 was also examined. Under all the tested experimental conditions, alumina is a much better adsorbent for tungsten than for rhenium. The obtained results indicated that the best separation of these two elements is achieved when 0.01? 0.1 mol dm-3HCl or 1.0mol dm-3 HNO3 are used as the aqueous media. If NaCl is used as the aqueous phase, the best separation is achieved with 0.20 mol dm-3 NaCl pH 4?6. Under these experimental conditions, the breakthrough and saturation capacities of alumina for tungsten at pH4 are 17 and 26 mg W/g Al2O3 respectively. With increasing pH, these values decrease. Thus, at pH 6 they are only 4 and 13 mg W/g Al2O3, respectively.

Seed germination and emergence of two flax-leaf alyssum (Alyssum linifolium Steph. ex. Willd.) populations in response to environmental factors

2019 ◽  
Vol 70 (9) ◽  
pp. 807
Author(s):  
A. Mobli ◽  
S. Mijani ◽  
A. Ghanbari ◽  
M. Rastgoo
Keyword(s):  
Seedling Emergence ◽  
Germination Percentage ◽  
Climatic Conditions ◽  
Weed Species ◽  
Experimental Conditions ◽  
Temperature Regimes ◽  
Wide Range ◽  
Ph Range ◽  
East Azerbaijan ◽  
Two Populations

Flax-leaf alyssum (Alyssum linifolium Steph. ex. Willd.) is a winter growing annual weed species widely distributed in many semi-arid cropping regions of Iran, especially in the Khorasan Razavi and East Azerbaijan provinces. The germination of two populations (one each from Khorasan Razavi and East Azerbaijan) of this weed was evaluated under different experimental conditions. Seeds of A. linifolium germinated over a wide range of day/night temperature regimes, with the highest germination percentage observed with a regimen of 20°C/10°C. Light was not required for germination for either population, and >70% seeds germinated under all photoperiods tested. Germination was affected by pH levels; seeds germinated over the pH range 4–9 and germination was maximum at pH 7. For the Khorasan Razavi and East Azerbaijan populations, ≥50% of seeds germinated at a water potential of –0.69 and –0.78 MPa and salinity of 12.64 and 11.7 dS m–1 respectively. Maximum seedling emergence occurred when seeds were slightly covered with soil, but emergence decreased with increasing depth of soil cover, with no emergence at depths >3 cm. These results indicate that A. linifolium germinates in a wide range of climatic conditions and could invade into new regions. Burying the seeds through tillage may reduce their emergence.

scholarly journals A Machine Learning Tool to Predict the Antibacterial Capacity of Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1774
Author(s):  
Mahsa Mirzaei ◽  
Irini Furxhi ◽  
Finbarr Murphy ◽  
Martin Mullins
Keyword(s):  
Machine Learning ◽  
Performance Metrics ◽  
Exposure Dose ◽  
Health Concern ◽  
Resistant Bacteria ◽  
Attribute Importance ◽  
Experimental Conditions ◽  
Wide Range ◽  
Antibacterial Capacity

The emergence and rapid spread of multidrug-resistant bacteria strains are a public health concern. This emergence is caused by the overuse and misuse of antibiotics leading to the evolution of antibiotic-resistant strains. Nanoparticles (NPs) are objects with all three external dimensions in the nanoscale that varies from 1 to 100 nm. Research on NPs with enhanced antimicrobial activity as alternatives to antibiotics has grown due to the increased incidence of nosocomial and community acquired infections caused by pathogens. Machine learning (ML) tools have been used in the field of nanoinformatics with promising results. As a consequence of evident achievements on a wide range of predictive tasks, ML techniques are attracting significant interest across a variety of stakeholders. In this article, we present an ML tool that successfully predicts the antibacterial capacity of NPs while the model’s validation demonstrates encouraging results (R2 = 0.78). The data were compiled after a literature review of 60 articles and consist of key physico-chemical (p-chem) properties and experimental conditions (exposure variables and bacterial clustering) from in vitro studies. Following data homogenization and pre-processing, we trained various regression algorithms and we validated them using diverse performance metrics. Finally, an important attribute evaluation, which ranks the attributes that are most important in predicting the outcome, was performed. The attribute importance revealed that NP core size, the exposure dose, and the species of bacterium are key variables in predicting the antibacterial effect of NPs. This tool assists various stakeholders and scientists in predicting the antibacterial effects of NPs based on their p-chem properties and diverse exposure settings. This concept also aids the safe-by-design paradigm by incorporating functionality tools.

scholarly journals Injection of mice with antibody to interferon enhances the growth of transplantable murine tumors.

1983 ◽  
Vol 158 (6) ◽  
pp. 2095-2107 ◽  
Author(s):  
I Gresser ◽  
F Belardelli ◽  
C Maury ◽  
M T Maunoury ◽  
M G Tovey
Keyword(s):  
Tumor Cell ◽  
Tumor Cells ◽  
Biologically Active ◽  
Experimental Conditions ◽  
Murine Tumors ◽  
Erythroleukemia Cells ◽  
Resistant Lines ◽  
Wide Range ◽  
Immunocompetent Mice

Injection of DBA/2, C57Bl/6, or BALB/c mice with antibody to mouse interferon alpha/beta enhanced the i.p. transplantability of six different murine tumors, as manifested by an increase in the percentage of tumor-bearing mice and a decrease in survival time. The effect was observed in mice injected with antibody to interferon raised in three sheep, a goat, and a rabbit, but not with sheep antibody to "impurities" present in the mouse interferon preparations or with normal sheep or goat globulins. The enhancement in transplantability was most marked when tumor cells had been previously passaged in vitro and were of low tumorigenicity. Analysis of some of the experimental conditions using interferon-sensitive and interferon-resistant lines of Friend erythroleukemia cells (FLC) showed that the enhancing effect was observed over a wide range of tumor cell inocula, was directly related to the amount of antibody to interferon injected and was most pronounced when antibody was administered at the time of tumor cell injection. Enhancement was also observed when FLC were injected subcutaneously (s.c.). Antibody did not act directly on the tumor cells in vitro. Although we were unable to demonstrate any biologically active interferon in mice before or after tumor cell inoculation, the results suggest that endogenous interferon is present and plays a role in inhibiting the transplantability of some murine tumors in immunocompetent mice.

FEEDING VALUE OF FORAGE AS FED TO STEERS AND ESTIMATED BY IN VITRO DIGESTION

1970 ◽  
Vol 50 (3) ◽  
pp. 547-555 ◽  
Author(s):  
J. E. TROELSEN ◽  
S. E. BEACOM
Keyword(s):  
Body Weight Gain ◽  
In Vitro Digestion ◽  
Experimental Conditions ◽  
Wide Range ◽  
Digestible Organic Matter ◽  
Feeding Value ◽  
Voluntary Intake ◽  
Highly Correlated

The digestibility and intake of 23 hays and three silages were determined in two experiments with Hereford steers averaging 215 kg at the start of the test. Each forage was fed in a chopped (4 to 6 cm) form as the sole diet to two steers for 56 days. Voluntary intake and body weight gain during the fourth through the seventh week were used as measures of animal performance. Digestibility was determined by collecting all the feces during the eighth week, allowing for a three-day lag between intake and excretion. The forages included grass, legume and cereal hays, and cereal and legume cereal silages produced under a wide range of conditions. The concentration of in vitro digestible organic matter (DOM) in the forage was highly correlated with gain (r = 0.57 and 0.86) and intake of digestible energy (DE) (r = 0.62 and 0.89). The voluntary intake by the steers was comparable with that by sheep in earlier experiments at two other locations, when the intake was based on metabolic body size, and on similar in vitro DOM or in vivo DE concentrations in the forage. Differences in intake between experiments followed the same pattern as feed allowance in excess of intake, but the effect of in vitro DOM or in vivo DE content on intake was apparently the same in each experiment. This supported the theory that regressions of DE intake by sheep on in vitro DOM content of forage will serve as a measure of the feeding value, providing that appropriate experimental conditions are maintained.

scholarly journals Progranulin Adsorbs to Polypropylene Tubes and Disrupts Functional Assays: Implications for Research, Biomarker Studies, and Therapeutics

2020 ◽  
Vol 14 ◽  
Author(s):  
Sushmitha Gururaj ◽  
Paul J. Sampognaro ◽  
Andrea R. Argouarch ◽  
Aimee W. Kao
Keyword(s):  
Incubation Time ◽  
Basic Science ◽  
Scientific Community ◽  
Biological Processes ◽  
Experimental Conditions ◽  
Functional Assays ◽  
Wide Range ◽  
Science Laboratories ◽  
Proteins And Peptides

Progranulin (PGRN) is a tightly regulated, secreted glycoprotein involved in a wide range of biological processes that is of tremendous interest to the scientific community due to its involvement in neoplastic, neurodevelopmental, and neurodegenerative diseases. In particular, progranulin haploinsufficiency leads to frontotemporal dementia. While performing experiments with a HIS-tagged recombinant human (rh) PGRN protein, we observed a measurable depletion of protein from solution due to its adsorption onto polypropylene (PPE) microcentrifuge tubes. In this study, we have quantified the extent of rhPGRN adsorption to PPE tubes while varying experimental conditions, including incubation time and temperature. We found that ∼25–35% of rhPGRN becomes adsorbed to the surface of PPE tubes even after a short incubation period. We then directly showed the deleterious impact of PGRN adsorption in functional assays and have recommended alternative labware to minimize these effects. Although the risk of adsorption of some purified proteins and peptides to polymer plastics has been characterized previously, this is the first report of rhPGRN adsorption. Moreover, since PGRN is currently being studied and utilized in both basic science laboratories to perform in vitro studies and translational laboratories to survey PGRN as a quantitative dementia biomarker and potential replacement therapy, the reported observations here are broadly impactful and will likely significantly affect the design and interpretation of future experiments centered on progranulin biology.

Cobalt(II), nickel(II), and copper(II) complexes of di- and tetrapeptides containing tyrosine and glycine residues

1979 ◽  
Vol 57 (1) ◽  
pp. 104-112 ◽  
Author(s):  
Mohamed S. El- Ezaby ◽  
Jassim M. Al-Hassan ◽  
Namek F. Eweiss ◽  
Farida Al-Massaad
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Mixed Solvent ◽  
Equilibrium Constants ◽  
Carboxyl Groups ◽  
Experimental Conditions ◽  
Ph Titration ◽  
Solution Equilibria ◽  
Wide Range ◽  
Ph Range

The solution equilibria of di- and tetrapeptides containing tyrosine and glycine residues have been investigated in absence and presence of cobalt(II), nickel(II), and copper(II) ions. The equilibrium constants have been determined by pH titration at 30 °C and μ = 0.1 M(NaNO3) in 80% by weight DMSO – water mixed solvent. Protons are ionized from terminal (protonated amino and carboxyl) groups as well as from peptidic nitrogens. Complexes of 1:1 composition of metal ion – tetrapeptides were formed in quite a wide range of pH; also 1:1 complexes of the metal ions – dipeptides were formed in solution under the same conditions. Other higher complexes cannot be proved to form in the pH range studied. The complexes of these metal ions with glycine and O-Bzl-L-tyrosine were also studied under the same experimental conditions as control experiments and their equilibrium constants were calculated.

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