Tetrazolium salts are commonly used in cytochemical and biochemical studies as indicators of metabolic activity of cells. Formazans, formed by reduction of tetrazolium salts, behave as ...pseudo-solutions during initial incubation, which allows monitoring their optical density throughout incubation. The criteria and conditions for measuring oxidative activity of mitochondria and dehydrogenase activity in reduction of nitroblue tetrazolium (NBT) and methyl thiazolyl tetrazolium (MTT) in suspensions of isolated mitochondria, tissue homogenates, and leukocytes were investigated in this work. We found that the reduction of these two acceptors depended on the oxidized substrate–NBT was reduced more readily during succinate oxidation, while MTT–during oxidation of NAD-dependent substrates. Reduction of both acceptors was more sensitive to dehydrogenase inhibitors that to respiratory chain inhibitors. The reduction of NBT in isolated mitochondria, in leukocytes in the presence of digitonin, and in liver and kidney homogenates was completely blocked by succinate dehydrogenase inhibitors–malonate and TTFA. Based on these criteria, activation of succinate oxidation was revealed from the increase in malonate-sensitive fraction of the reduced NBT under physiological stress. The effect of progesterone and its synthetic analogs on oxidation of NAD-dependent substrates by mitochondria was investigated using MTT. Both acceptors are also reduced by superoxide anion; the impact of this reaction is negligible or completely absent under physiological conditions, but can become detectable on generation of superoxide induced by inhibitors of individual enzyme complexes or in the case of mitochondrial dysfunction. The results indicate that the recording of optical density of reduced NBT and MTT is a highly sensitive method for evaluation of metabolic activity of mitochondria applicable for different incubation conditions, it offers certain advantages in comparison with other methods (simultaneous incubation of a large set of probes in spectral cuvettes or plates); moreover, it allows determination of activity of separate redox-dependent enzymes when selective inhibitors are available.
The COVID-19 outbreak started in December 2019 in China has spread over all countries of the world within few month acquiring a pandemic nature, the incident population counting millions. The ...pathogenic mechanisms of the new coronaviral infection caused by never-before-seen virus SARS-CoV2 are yet to be studied. Various drugs are used for COVID-19 treatment and guidelines are continuously revised as new experience is acquired. In the current pandemic situation, it is important to provide specialists with latest information concerning efficacy and safety drugs for COVID-19 patients and promising research in this field.The purpose of the review is to critically analyze published data on outcomes of COVID-19 treatment with various drugs including potentially promising drugs.The search has been carried out through such databases as PubMed, Scopus, Cyberleninka, https://www.globalclinicaltrialsdata.com, https://clinicaltrials.gov, Cochrane Library; mostly, randomized clinical trials-2020 and papers dedicated to candidate drugs have been considered. The paper is structured based on the drug’s action mechanism and contains parts dedicated to antiviral, immunomodulatory, and antibacterial therapies. Looking for a new promising target in COVID-19 treatment, the authors focus their attention on matrix metalloproteinases (MMP), which abundance results in the destruction of extracellular matrix, epithelial and endothelial basal membranes and leads to secondary lung tissue injury. The paper provides a theoretic justification of MMP inhibitor use by an example of doxycycline and offers an efficacy study protocol for the new approach to COVID-19 therapy.Conclusion: as of now, there are no drugs which efficacy for COVID 19 has been proven. Drugs possessing multiple mechanisms of action are employed beside their specified indications, often in combinations; in this situation, additive side effects with adverse consequences for the patient can hardly be avoided. Administration of drugs with unproven efficacy may be justified only in clinical trials followed by subsequent analysis and publication of findings demonstrating that in case of success, recommendations for a majority of COVID-19 patients could be confidently issued.
We present the results of the determination of eight aromatic microbial metabolites, phenylcarboxylic acids (PhCAs), by gas chromatography–mass spectrometry after their liquid–liquid extraction from ...serum samples and derivatization. The analytical range for the analytes is 0.5–40 μM. The concentration of phenylcarboxylic acids in the serum of healthy donors (
n
= 40) and the time profile of the concentration of different PhCAs in serum samples of four patients from the intensive care unit (ICU) are studied. The results correlated with the severity of the clinical state of patients.
Radical changes in the composition, diversity and metabolic activity of gut microbiome in critically ill patients most probably affect adversely the outcome of treatment. Microbiota dysfunction may ...be a predictor and presumably the main cause of infectious complications and sepsis. Clinicists use objective scales for evaluation of patient condition severity including specific parameters of disorders of organs and systems; however, microbiota function is not considered specific and, hence, not evaluated. Technical capabilities of the recent decade have allowed characterizing the intestinal microbiota and that helped understanding the ongoing processes. The authors have analyzed data about the role of intestinal microbiota as a metabolic 'reactor' during critical states, possible complications related to misbalance of 'harmful' and 'beneficial' bacteria, and examined potential of a targeted therapy aimed directly at correction of intestinal microbiota. Search for papers was carried out using Scopus and Web of Science databases 2001 to 2018 years: (Gut Microbiota) AND (Critically ill OR Intensive care unit), key words taken for the search were: intestinal microbiota, metabolism, sepsis, antibiotics, critically ill patients, multiple organ failure. A number of questions in understanding of the interaction between gut microbiome and host remain open. It is necessary to take into account interference of microbial metabolism while assessing metabolome of patients with sepsis. Among low-molecular compounds found in blood of sepsis patients, special attention should be paid to molecules that can be classified as ‘common metabolites’ of humans and bacteria, for example, degradation products of aromatic compounds, which many-fold rise in blood of septic patients. It is necessary to take into consideration and experimentally model changes in the human internal environment, which occur during radical transformation of microbiome in critically ill patients. Such approach brings in new prospects for objective monitoring of diseases by evaluating metabolic profile at a particular moment of time based on integral indices reflecting the status of microbiome/metabolome system, which will supply new targets for therapeutic intervention in future.
Mitochondrial dysfunction is the main factor in the development of multiple organ failure in sepsis. The role of microbial metabolites in the induction of mitochondrial dysfunction was studied in ...this work. The effect of phenolic acids of microbial origin on the functions of mitochondria in acidosis and deficiency of the substrate of oxidation accompanying the development of sepsis was investigated. These conditions considerably enhanced the effects of benzoic, phenylpropanoic, phenylpropionic, and phenylacetic acids on the induction of the mitochondrial pore, oxidation of NADH, and oxidative phosphorylation in isolated liver mitochondria. The deficiency of the substrate of oxidation was the most effective factor that enhanced the effect of phenolic acids. Preincubation of mitochondria with phenolic acids in the absence of the substrate of oxidation was accompanied by a significant inhibition of the dehydrogenases of the tricarboxylic acid cycle. The obtained data indicate a potential role of phenolic acids of microbial origin in the development of mitochondrial dysfunction in inflammation and sepsis.
Aim.
To evaluate the safety and efficacy of the adaptive phage therapy technique in patients with recurrent pneumonia in neurological critical care.
Material and methods.
The clinical study included ...83 chronically critically ill patients with severe brain damage. The bacteriophage cocktail selected against specific hospital strains was administered by inhalation to 43 patients. The control group included 40 patients who received conventional antimicrobial therapy. The changes in clinical, laboratory and instrumental parameters, levels of biomarkers, microbiological and PCR tests of bronchoalveolar lavage fluid were assessed, including those in the «phage therapy with antibiotics» (
n
=29) and «phage therapy without antibiotics» (
n
=14) subgroups.
Results.
The groups were comparable in terms of basic parameters (age, sex, diagnosis, organ dysfunction according to APACHE II, use of vasoactive drugs) and the level of airway colonization with antibioticresistant bacterial strains. Good tolerability and absence of clinically significant side effects were observed during inhaled administration of the bacteriophage cocktail. Computed tomography on day 21 showed a significant reduction in lung damage in patients who received bacteriophages. Patients treated with bacteriophages without antibiotics had significantly lower need for mechanical ventilation. The mortality rate on day 28 did not differ significantly and was 4.7% (2/43) in the bacteriophage-treated group vs 5% (2/40) in the control group.
Conclusion.
The first experience of using the adaptive phage therapy technique in chronically critically ill patients in neurological intensive care demonstrated the safety of inhalational administration of the bacteriophage cocktail. The efficacy of the technique was confirmed by the treatment results obtained in the phage therapy group, which were not inferior to those in the group with conventional antibiotic therapy, while several clinical and laboratory parameters tended to improve even in patients who received bacteriophages and did not receive antibiotics.
The term “chronic critical illness” (CCI) refers to patients with
prolonged dependence on intensive care. In most patients, CCI is triggered
by severe brain injury. Ever more studies researching the ...microbiota in
pathologic conditions are published every year, but a lot is yet to be
elucidated about the composition of the gut microbiota in CCI. The aim of
this study was to investigate possible correlations between changes in the
taxonomic abundance of the gut microbiota, levels of proinflammatory and
neurological serum biomarkers and the severity of central nervous system
injury in patients with CCI. Our prospective observational pilot study
included 29 patients with CCI. Using real-time PCR allowed us to detected
changes in the taxonomic abundance of the gut microbiota. The correlation
analysis of serum biomarkers and the taxonomic composition of the gut
microbiota revealed statistically significant correlations between cortisol
levels and the abundance of F. prausnitzii (r = ‒0.62; p < 0.05) and B.
thetaiotaomicron (r = ‒0.57; p < 0.05) in vegetative state patients;
between the CRP/albumin ratio and the abundance of S. aureus (r = 0.72; p
< 0.05); between the abundance of B. fragilis group/F. prausnitzii and
S100 levels (r = 0.45; p <0.05) in conscious patients; between Glasgow
coma scale scores and the abundance of Enterococcus spp. (r = ‒0.77; p
<0.05) in both groups. Thus, the association between the changes in the
taxonomic composition of the gut microbiota and the severity of neurologic
deficit can be evaluated using PCR-based diagnostic techniques and blood
serum biomarkers. This approach will help to optimize antibacterial
treatment regimens and/or develop alternative strategies to minimize the
aggressive effect of antibiotics on the gut microbiota.
The article explains the necessity to use cross-methodological approach to realization of marketing analytical function that combines methodology of classical marketing research and DataScience ...methodology. The explanation is based on results of literature analysis, which studies trends of DataDriven marketing development and DataScience; HeadHunter research dealing with assessing the compliance of the competence profile of specialist in the field of analytical marketing with demands of labour market and on results of the authors’ research in the present sphere. Comparative appraisal of efficiency of using classical methods of marketing research and DataScience methodology was conducted at enterprises; benefits and drawbacks of each of them were identified; similar and distinguishing stages of these approaches were found and efficiency of their integration was proved. Progress of Russian companies in realization of marketing analytical function by using DataDriven culture was estimated. Two principle reasons hindering the process of marketing based on data introduction to Russian organizations were named, i.e. non-compliance of competence profile of marketers-analysts//with market demands and uncoordinated investment in technologies aiming at DataDriven approach introduction into the company.
Previous studies showed that large amounts of phenylcarboxylic acids (PhCAs) are accumulated in a septic patient’s blood due to increased endogenous and microbial phenylalanine and tyrosine ...biotransformation. Frequently, biochemical aromatic amino acid transformation into PhCAs is considered functionally insignificant for people without monogenetic hereditary diseases. The blood of healthy people contains the same PhCAs that are typical for septic patients as shown in this paper. The overall serum PhCAs level was 6 μM on average as measured by gas chromatography with flame ionization detection. This level is a stable biochemical parameter indicating the normal metabolism of aromatic amino acids. The concentrations of PhCAs in the metabolic profile of healthy people are distributed as follows: phenylacetic ≈
p
-hydroxyphenyllactic >
p
-hydroxyphenylacetic > phenyllactic ≈ phenylpropionic > benzoic. We conclude that maintaining of stable PhCAs level in the serum is provided as the result of integration of human endogenous metabolic pathways and microbiota.
A review on the quantitative determination of aromatic monocarboxylic acids (AMCAs), intermediates in the metabolism of the proteinogenic amino acids phenylalanine and tyrosine, in body fluids is ...presented. The importance of these compounds as potential diagnostic low-molecular-weight biomarkers of some human diseases is described. The main methodical features of current practical solutions in the field of highly sensitive screening of AMCAs in body fluids using chromatography-mass spectrometry and other methods actively used in clinical laboratory analysis are considered. Special attention is paid to the prospects of developing portable tools for therapeutic monitoring of the compounds of interest in biological fluids. The bibliography includes 108 references.
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