The effects of the probiotic Subtilis on the peripheral blood system of Clarias gariepinus

The article discusses the prospects for using probiotics in aquaculture. The effect of probiotics on the physiological processes in the body of African catfish grown under artificial breeding is discussed. The effectiveness of using probiotics to increase productivity, improve the gastrointestinal tract of fish, increase non-specific resistance and stress resistance is analyzed. The results of our own research on the use of the probiotic Subtilis, which is currently used in many industries, including fish farming, are presented. The aim of the work was to study the effect of the probiotic subtilis on the erythron system and on the structure of the leukocyte formula of African catfish. Against the background of the probiotic subtilis, the total number of red blood cells in the bloodstream was increasing, and the proportion of immature forms was progressively decreasing. The seasonal dynamics and sexual characteristics of the catfish peripheral blood system were studied with the use of a probiotic. In general, the stimulating effect of the probiotic subtilis on erythropoiesis and the white blood system was found. Analysis of the leukogram of African catfish indicated the activation of the cellular component of the immune system when using a probiotic in feeding. Our results allow us to recommend the use of the probiotic subtilis for the cultivation of African catfish in industrial aquaculture. This work was supported by the Russian Foundation for Basic Research with the grant 18-016-00127

Vectors for the development of high-tech industrial aquaculture

The article discusses the prospects of optimizing the technology of growing African catfish in high-tech industrial aquaculture. The goal was to determine the range of biologically active substances that can increase the productivity, organoleptic qualities of fish grown in recirculating aquaculture systems and optimize their living conditions. For this purpose, a complex of biologically active substances was tested, including probiotics, prebiotics, amino acids, and natural sorbents. It was introduced into feed and added to the water of fish tanks. Studies have shown that the developed complex of biologically active substances accelerates growth and development, guarantees the growth of fish biomass, reduces the level of bacterial pollution of the fish habitat, and normalizes hydrochemical parameters in the tanks. Improving the technology of fish farming in recirculating aquaculture systems (RAS) involves changing the ideology of feeding and keeping fish. The results of our studies show that, under conditions of artificial breeding in RAS, it is necessary to use cultures of living microorganisms probiotics that improve intestinal microbiocenosis in fish feeding and introduce them into the fish habitat. Probiotics should be used with prebiotics containing vitamin-amino acid complexes that stimulate the development of symbiotic microbiota. The use of natural sorbents plays an important role. The proposed set of ingredients increases the organoleptic qualities of fish. The studies were supported by the Russian Foundation for Basic Research with grant 18-016-00127

Effect of feed composition on the nutritional value of meat of African catfish

The article outlines the results of the research into the influence of feed composition on the amino acid value of African catfish meat. It has been shown that quality characteristics of fish meat depend on protein and fat content. It has been proved that high-protein feed ensures increase in the content of all amino acids in African catfish meat. Nevertheless, protein and fat content in the muscles of the studied fish is more than 2 times higher than the same indicator in the fish on low-protein and low-fat diet. Meat of the African catfish is rich in two amino acids – leucine and lysine. Two amino acids, tryptophan and methionine, are limitative at a high protein diet. At a lower protein diet, isoleucine amino acid is also added. The amino acid composition of African catfish meat is highest at high-protein feeds. The amino acid index of African catfish muscles at high-protein feeds is 0.48, significantly exceeding the index of fish bred on feeds with a reduced protein content. The conducted studies have shown that the use of high-protein feeds in catfish breeding stimulates protein metabolism, enriching the amino acid composition of muscle tissue and increasing the nutritional value of fish as a food product. The research has been funded by the Russian Foundation for Fundamental Research, project No. 18-016-00127

Increase in nonspecific resistance of catfish (

The article discusses prospects for use of the theory of adaptogens in demand in medicine and in the fish breeding practice. The obtained results show that the adaptogens use at the early stages of catfish ontogenesis (Clarias Gariepinus, Burchell 1822) can cause the condition of nonspecific increased resistance and expand the adaptive flexibility range of this specie. Adaptogen trekrezan used in our experiments (Oxyethylammonium methylphenoxiacetate) is a synthetic analogue of the natural ginseng. Its application in the embryo culture process has shown positive results. It has reduced the level of the developmental anomaly, increased the first stage larvae hatching and their viability, significantly decreased the mortality rate and reduced the level of cannibalism common for catfish larvae. We have determined that the larvae breeding in the trekrezan medium has considerably increased their growth rate, and weight gain. The obtained results are new, and the adaptogens use at the early stages of ontogenesis in industrial catfish aquaculture is recommended. The Russian Foundation for Basic Research has supported our study with the grant No. 18-416-730005

Seasonal studies of caviar production and the growth rate of the African catfish (Clarias gariepinus, Burchell, 1822)

Issues of African catfish caviar production organization were studied in the present work. Prospects of all-season African catfish caviar production in recirculating aquaculture system were investigated. The purpose of the study was to evaluate season-dependent dynamics of caviar production, duration of pre-spawning period and dynamics of postembryonic ontogenesis of African catfish generations, reproduced within autumn-winter and spring-summer periods. The tasks of the study included: comparative analysis of male and female pre-spawning periods in different seasons; hormonal stimulation; eggs fertilization; eggs growth to larval stage; evaluation of dynamics of larvae and fry growth reproduced in spring and autumn period. The study results showed that caviar productivity of African catfish females, characterized by multiple spawning, decreased by two times in November as compared to spring period, and depended on the duration of pre-spawning period. Dynamics of gonads development was also season-dependent. In autumn period the duration of pre-spawning preparation, necessary for gonads maturation, was twice as long as spring one. Males and females did not respond to hormonal stimulation if pre-spawning conditions failed to comply. Growth rate of African catfish larvae and fry, reproduced in autumn period, was slower as compared to those that were reproduced in spring. Keywords: Aquaculture, Gonads, Eggs fertilization, Milt, Productivity, Season-dependent dynamic

Safety and preliminary efficacy of human adult liver progenitor cells (HepaStem TM) in patients with acute-on-chronic liver failure (ACLF) or acute decompensation (AD) at risk of developing ACLF

F. NEVENS (1), T. GUSTOT (2), P. LATERRE (3), L. LASSER (4), L. HARALAMPIEV (5), V. VARGAS (6), D. LYUBOMIROVA (7), A. ALBILLOS (8), V. BARTHEL (9), N. CLERGET-CHOSSAT (9), E. SOKAL (9) / [1] KU Leuven, , Belgium, Hepatology and Liver Transplantation , [2] Erasme Hospital, Brussels, Belgium, Gastroenterology/HepatoPancreatology/Digestive Oncology, [3] Saint-Luc University Hospital, Brussel, Belgium, Intensive Care, [4] CHU Brugmann, Brussels, Belgium, Gastroenterology, [5] Hospital Medica Ruse, Ruse, Bulgaria, Internal Diseases, [6] Hospital Vall d’Hebron, Barcelona, Spain, Hepatology, [7] University Multiprofile Hospital for Active Treatment "Dr. Georgi Stranski", Pleven, Bulgaria, Clinical Gastroenterology with Hepatology, [8] Hospital Universitario Ramón y Cajal Catedrático de Medicina, Universidad de Alcalá, Madrid, Spain, Gastroenterology and Hepatology, [9] Promethera Biosciences, Mont-Saint-Guibert, Belgium, Product Development Introduction Acute-on-chronic liver failure (ACLF) is characterized by acute decompensation (AD) of cirrhosis associated with failure of one or more organs. HepaStem™ is a suspension of Human Allogenic Liver Progenitor Cells derived and expanded from the parenchymal fraction of collagenase-digested adult human liver. The immunomodulatory properties of HepaStem™ are expected to restore immune balance and liver function in patients with ACLF or AD. Aim The primary objective is the safety of 1 or 2 infusions of various doses of cells up to Day (D)28 post treatment. Secondary objectives include preliminary efficacy up to month (M)3. Methods Twenty-four patients were enrolled. The first patient (ACLF) received no cells due to technical issue. The second patient (ACLF) received 2 infusions of 4.2 x 10⁶ cells/kg, the third patient (ACLF) received 1 infusion of 5.3 x 10⁶ cells/kg, 6 patients (2 ACLF and 4 AD) 1 infusion of 0.6-0.8 x 10⁶ cells/kg, 3 patients (2 ACLF and 1 AD) 2 infusions of 0.6 x 10⁶cells/kg, and 12 patients (9 ACLF and 3 AD) 1 or 2 infusion of 1.2 x 10⁶ cells/kg. Results The second patient had severe epistaxis and the third one bled at the puncture site of the transjugular biopsy. They recovered; one had liver transplantation and the other one was well at 1 year. After dose adjustment in the subsequent dose-cohorts, no serious events causally related to HepaStem™ were reported. No other bleedings occurred, or any drop of platelets, fibrinogen, or coagulation factors. Adverse events were in line with those expected regarding the underlying diseases and comorbidities. In patients without liver transplantation (N=18), bilirubin and MELD score decreased, and albumin slightly increased as compared to pre-infusion values. Also, elevated baseline levels of C-Reactive Protein and neutrophil counts returned to normal in most patients. Conclusions At high cell doses (250 x 10⁶ cells), 2 patients with initial severe coagulation disturbances experienced bleeding possibly related to HepaStem™. This could be linked to tissue factor expressed by HepaStem™, which activate the coagulation cascade and lead to consumption of coagulation factors, as shown in preclinical studies. No bleedings related to HepaStem occurred at 0.6 to 1.2 x 10⁶ cells/kg doses, or changes in coagulation parameters; these dosages were safe in this AD/ACLF patient population. Preliminary data showed improvement of liver function and systemic inflammation post infusion. The clinically significant MELD and bilirubin improvement is considered as an encouraging sign of efficacy