Evaluation of approaches to increase the effectiveness of various disinfectants against biofilm communities of different ages

Disinfectants are used as the main agents against microorganisms circulating on the surfaces of food enterprises. However, the adaptive ability of microorganisms to form biofilms complicates the process of surface cleaning and reduces the effectiveness of disinfectants. Modern disinfectants act against freely circulating microflora, but it is known that they are not always effective against biofilms. The purpose of this study was to investigate effective disinfectant compositions with bactericidal effect on binary bacterial biofilms of different ages. The article describes the effects of disinfectants based on chlorine, peracetic acid and quaternary ammonium compounds with enzymes in concentrations recommended by the manufacturer and increased several times on Salmonella 38, Brochothrix thermosphacta 2726 and Staphylococcus equorum 2736 planktonic cultures and binary biofilms. Binary biofilms of different ages (2 and 9 days old) were exposed to disinfectants with various active ingredients in combination with adjuvants, i. e. hydrogen peroxide 6% and various concentrations of isopropyl alcohol (30%). All products in concentrations recommended by the manufacturer did not have a disinfectant effect against the studied biofilm cultures. As a result of the work, it was found that the most effective disinfectants against multispecies biofilms were quaternary ammonium compounds in combination with enzymes and chlorine in combination with isopropyl alcohol (30%). The results obtained allow to expand knowledge about effective methods for controlling biofilms.Disinfectants are used as the main agents against microorganisms circulating on the surfaces of food enterprises. However, the adaptive ability of microorganisms to form biofilms complicates the process of surface cleaning and reduces the effectiveness of disinfectants. Modern disinfectants act against freely circulating microflora, but it is known that they are not always effective against biofilms. The purpose of this study was to investigate effective disinfectant compositions with bactericidal effect on binary bacterial biofilms of different ages. The article describes the effects of disinfectants based on chlorine, peracetic acid and quaternary ammonium compounds with enzymes in concentrations recommended by the manufacturer and increased several times on Salmonella 38, Brochothrix thermosphacta 2726 and Staphylococcus equorum 2736 planktonic cultures and binary biofilms. Binary biofilms of different ages (2 and 9 days old) were exposed to disinfectants with various active ingredients in combination with adjuvants, i. e. hydrogen peroxide 6% and various concentrations of isopropyl alcohol (30%). All products in concentrations recommended by the manufacturer did not have a disinfectant effect against the studied biofilm cultures. As a result of the work, it was found that the most effective disinfectants against multispecies biofilms were quaternary ammonium compounds in combination with enzymes and chlorine in combination with isopropyl alcohol (30%). The results obtained allow to expand knowledge about effective methods for controlling biofilms

Social Network-Based Digital Stroke Prevention: Opportunities, Results and Prospects

Aim. To study the possibilities and limitations of the social network as a digital medical tool, which is aimed at improving programs for primary and secondary stroke prevention in young people.Material and methods. The study was carried out in the format of online training for volunteers. At the first stage of the work, the online school “Stroke in Young People” was announced in 8 medical blogs. As part of the school, a special account was created for readers (n=1354). At the second stage, 49 respondents (4% of men, whose average age was 24.4±5.2 years) were selected from 1354 listeners, who were surveyed on “Awareness of risk factors and stroke symptoms among users of social networks” before and after the online school.Results. The online school audience is predominantly female (91%), and 43% of readers were in the 25-34 age group. The total number of people who listened to and read the online school material is 8712 people. 17% worked in the healthcare system, and 22% of respondents had a history of stroke. 38 (78%) people of the 2nd stage among the respondents independently searched for information about stroke earlier, and 30 (61%) received this information passively from medical workers in 2020. Before the online school start, the majority of respondents (over 60%) were aware of 2 out of 7 stroke risk factors (dyslipidemia and arterial hypertension) and 3 out of 6 stroke signs (drooping of the face half, weakness in the limbs and difficulty speaking). Less than 40% of the participants considered the stroke risk factors for diabetes mellitus, other cardiovascular diseases (CVD), obesity, and alcohol use; less than 20% were aware of stroke symptoms such as impaired vision and coordination and very severe headache. After completing online learning, the greatest increase in knowledge was found among the following risk factors – smoking and other CVDs (p<0.05); stroke symptoms - headache and drooping of the face half (p<0.05).Conclusion. The online school aroused interest among healthcare workers and people without medical education, including those with stroke. Most of the respondents believed that they knew how to prevent a stroke (over 80%) and would be able to provide first aid to a person with a stroke (over 90%). At the same time, the awareness of risk factors and stroke symptoms was low prior to the start of learning, even though the study included healthcare workers and stroke survivors. Online learning has led to increased awareness of some risk factors and stroke symptoms. Social media can be one of the tools for medical prevention of stroke in young people, but program planning should take into account the way the material is presented and its readability

Computational Modeling of Silicate Glasses: A Quantitative Structure-Property Relationship Perspective

This article reviews the present state of Quantitative Structure-Property Relationships (QSPR) in glass design and gives an outlook into future developments. First an overview is given of the statistical methodology, with particular emphasis to the integration of QSPR with molecular dynamics simulations to derive informative structural descriptors. Then, the potentiality of this approach as a tool for interpretative and predictive purposes is highlighted by a number of recent inspiring applications

DO FATS OR CARBOHYDRATES SHORTEN OUR LIVES? WHAT DOES THE PURE STUDY REVEAL?

Healthy nutrition decreases the risk of cardiovascular disorders (CVD). Optimal content of fatty acids is an important point in clinical guidelines. However, during more than a half century of observation, the influence of fatty acids on CVD development is still debated. Recent decades, there has been a range of ecological studies conducted, on the relation of macronutrients (proteins, fats, carbohydrates) and CVD. In 2017, at the annual Congress of Cardiological society, results of PURE study (Prospective Urban and Rural Epidemiological Study) were reported. The article as focused on analysis of the PURE and explores reasons for the results as these were reported

Subkurgan Paleosoils of the Lower Volga Steppes as Indicators of Climate Dynamics over an Historical Epoch

The studies of paleosoils buried beneath burial mounds of the Early, Middle, and Late Sarmatian time (4th c. BC to 4th c. AD) were carried out in the dry and desert steppes of the Lower Volga river area (the Volga and Yergenino uplands, the Caspian lowland). It was established that within the chronological interval of 2400–1600 years ago temporal variability of morphological, chemical, microbiological, and magnetic properties of paleosoils was rhythmical, being conditioned by the centennial dynamics of climate humidity with oscillations of mean annual precipitation rate within ±30–50 mm. The periodic change of humid and arid climatic epochs considerably influenced soil salinization-desalinization, solonetz and humus formation processes, and biological activity of paleosoils of the solonetz alkali soil complexes. This stimulated essential changes in the structure of the soil covering with reversal evolutionary transformations of paleosoils on the levels of types, genera or species within several decades. The natural conditions within the existence of the Sarmatian culture society may be characterized as alternation of micropluvial and microarid periods with 100–200-year duration. In particular, both in dry (Volga-Don interfluve) and in desert (Trans-Volga) steppes, the 1st c. BC, AD 1st and 4th cc. were characterized by relatively humid conditions, while the 4th–3rd cc. BC and second half of the 2nd to first half of the 3rd cc. AD were most arid. Intermediate humidity situation close to modern time was characteristic of the period from the first half of the 2nd to the second half of 3rd century AD. The evolution of climatic conditions is generally consistent with the rhythms of natural processes in other steppe and desert regions of Eurasia

IMPACT OF THE RIGHT VENTRICLE DYSFUNCTION ON CHRONIC HEART FAILURE PRESENTATION IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY

Aim. To assess the function of the right ventricle (RV), its influence on clinical and instrumental presentation of chronic heart failure (CHF) in patients with hypertrophic cardiomyopathy (HCMP).Material and methods. Totally, 55 patients with HCMP included, males 17 (34%), mean age — 57,0±15,2 y. All patients were taking bisoprolol 5,7±1,2 mg. The study included assessment of clinical status of patients with Minnessota score of life quality in CHF, SQCA, brain natriuretic peptide (BNP) measurement in plasma, echoCG. With the aim to deeper investigate on cardiac function we asessed Tei index of the left ventricle (LV) and RV. As the result of all studies in HCMP there was increase of Tei of LV. Increase of RV Tei was found in 35 patients (63,6%). By Tei RV value, patients were selected to 2 groups: 1 group (n=35) — those with Tei RV higher than normal — ≥0,32 (0,58±0,2), 2 group (n=20) — with Tei RV <0,32 (0,23±0,09).Results. Patients from group 1 had higher clinical and laboratory markers of CHF: FC CHF by NYHA (p=0,008), summ by SQCA (p=0,03), BNP level in plasma 200 (p=0,01). In 1st group patients there was higher E/A (p=0,04), transmitral flow, lower regional systolic velocity on septal part of mitral annulus (MVFA) (p=0,04), free wall of tricuspid valve fibrous annulus (TVFA) (p=0,01), longer the time of isovolumetric relaxation on lateral (p=0,04) and posterior (p=0,03) regions of MVFA. There was negative correlation of Tei RV index and peak A (p=0,0007) and postitve — with E/A of transmitral flow (p=0,01). There was correlation of FC CHF by NYHA and s’ of free wall of TVFA (p=0,04); positive association of Tei RV and FC level of CHF by NYHA, BNP (p=0,01). There was negative association of BNP and systolic function of RV: s’ TVFA (p=0,01), s’ of basal part of RV free wall (p=0,002), s’ of median part of RV free wall (p=0,02).Conclusion. Presence of RV dysfunction by Tei index was found in 63,5% of patients with HCMP. RV dysfunction in HCMP is due to severely disordered diastolic dysfunction of LV, is followed by progression of CHF — increase of FC CHF, SQCA points summ, BNP level and decrease of segmental longitudinal function of myocardium by TDI

CARDIOVASCULAR HEMODYNAMICS AND SPECIFICS OF 24-HOUR BP PROFILE IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY AND INADEQUATE BP REACTION ON PHYSICAL EXERTION

Inadequate reaction of blood pressure (IRBP) in physical exertion in patients withhypertrophic cardiomyopathy (HCMP) is one of the risk factors of sudden cardiacdeath.Aim. To study structural and functional parameters of the heart, vessels and24-hour blood pressure parameters in patients with HCMP and IRBP in physicalexertion.Material and methods. 17 patients with HCMP (13 women, meanage54,0±11,4y.)underwent echocardiography (EchoCG), ambulatory blood pressure monitoring(ABPM) with assessment of vessels rigidity, exercise test on treadmill. By the resultsof treadmill test the patients were selected into 2 groups: I group (n=10, of those 7women, mean age 51,4±13,9y.) with IRBP, II group (n=7, of those 6 women, meanage 56,0±9,3y.)with normal BP reaction in physical exertion.Results. Presence of IRBP in physical exertion was associated: with more significantdiastolic dysfunction of the left ventricle (LV): the correlation is found with the peak delayed diastolic filling on mitral valve (peak A mv)(r=-0,76, p=0,002), relation of the velocities of early and delayed diastolic filling on the mitral valve (E/A mv) (r=0,53, p=0,03); decreased volume of LV: correlation with end-diastolic volume (EDV); end systolic volume (ESV) (r=-0,55, p=0,03); increased stiffness of arterial wall: correlation with the velocity of pulse wave (PWVao) (r=0,7, p=0,005), ambulatory index of vessel rigidity (MSI) (r=0,49, p=0,05), augmentation index (Axi) (r=-0,51, p=0,04).In discriminate analysis the EDV, E/A and AASI were the most significant predictors of IRBP. The functions were invented that make, by the highest value, an separation of a patients into one of 2 groups: I group (n=10, of those 7 women, mean age 51,4±13,9y.) with IRBP, II group (n=7, of those 6 women, mean age 56,0±9,3y.) with normal reaction of BP to physical exertion

ATRIAL FIBRILLATION AND FLUTTER IN HYPERTROPHIC CARDIOMYOPATHY

Aim. To find out the factors associated with atrial fibrillation/flutter (AF) in patients with hypertrophiccardiomyopathy.Material and methods. Totally 182 HCMP patients included, of those 103 — men (mean age 59,6±14,6y). Diagnosis of AFwas set using ECG or Holter monitoring of ECG using medical charts with the mentioned anamnesis of AF Results. Paroxysmal or permanent form of AF were found in 60 (33%) patients. AF patients were older (64,2±11,2 vs 57,3±15,6 y, p=0,005), with more significant symptomatics(CHFFCbyNYHA2,4±0,8vs2,1±0,8, p=0,02). In AF patients the size of left atrium (LA) was larger than in sinus patients (4,5±0,6 vs 4,1±0,7 cm, p=0,00003). Prevalence of outgoing tract of the left ventricle (OTLV) was nearly same in both groups (50% vs 52,2%, p=0,2), and maximum pressure gradient (PGmax) in OTLV was higher in AF patients (46,0±48,0 vs 21,8±26,6 mmHg, p=0,02). There is and increase of AF with the age (r=0,21, p=0,005), severity of symptoms (r=0,2, p=0,001), LAenlargement(r=0,44, p=0,04), severity of pulmonary hypertension (r=0,47, p=0,004), value of PGmax in OTLV (r=0,23, p=0,02). With the method of binary logistic regression 3 main variables were selected as the most of predictable value for AF: age, LA size, PGmax in OTLV. The model defined that makes to estimate the risk of AF with high diagnostic probability — x 22,0, df=3 (p=0,00006): AF = 0,05307 * age + 0,98065 * LA + 0,01516 * Рймакс in OTLV - 8,66. With the result >0 there is a high risk of AF, and if <0 — the risk of AF is minimum.Conclusion. The model invented for risk prediction in AF in HCMP patients using three predictors: patient age, left atrium diameter and maximum gradient of pressure in OTLV