The Influence of Storage Temperature and Packaging Technology on the Durability of Ready-to-Eat Preservative-Free Meat Bars with Dried Plasma

Food business operators must include the results of shelf life testing in their HACCP plan. Ready-to-eat preservative-free meat products enriched with blood plasma are an unfathomable area of research in food safety. We tested modified atmosphere (80% N2 and 20% CO2) and vacuum packaged RTE preservative-free baked and smoked pork bars with dried blood plasma for Aerobic Plate Count, yeast and mould, lactic acid bacteria, Staphylococcus aureus, Enterobacteriaceae, Escherichia coli, and Campylobacter spp., and the presence of Listeria monocytogenes and Salmonella spp. during storage (temperatures from 4 to 34 °C) up to 35 days after production. The obtained data on the count of individual groups of microorganisms were subjected to analysis of variance (ANOVA) and statistically tested (Student's t-test with the Bonferroni correction); for temperatures at which there were statistically significant differences and high numerical variability, the trend of changes in bacterial counts were visualised using mathematical modelling. The results show that the optimal storage conditions are refrigerated temperatures (up to 8 °C) for two weeks. At higher temperatures, food spoilage occurred due to the growth of aerobic bacteria, lactic acid bacteria, yeast, and mould. The MAP packaging method was more conducive to spoilage of the bars, especially in temperatures over 8 °C.

[Chaperone proteins involved in Rubisco biosynthesis]

Rubisco is an enzyme found in photosynthetic organisms, which catalyse the first step of biomass accumulation: the carbon dioxide incorporation to ribulose-1,5-bisphosphate. Because of Rubisco’s complicated, multimeric structure and a presence of many labile structural elements the enzyme cannot assemble to its native quaternary structure by itself. This is why the folding and assembly process of Rubisco requires the strictly organized operation of a number of auxiliary factors. Chaperone proteins take part in folding of holoenzyme subunits, subsequently they mediate in subunit oligomerisation, and in some cases chaperone proteins direct subunits to their cellular destination such as the carboxysomes or the pyrenoid. In addition to their canonical function of mediating Rubisco assembly, these chaperones are involved in additional processes such as quality control of the biosynthetic process, and regulation of organelle physiology and cellular compartments.

Biodegradable Fiducial Markers for Bimodal Near-Infrared Fluorescence- and X-ray-Based Imaging

This study aimed to evaluate, for the first time, implantable, biodegradable fiducial markers (FMs), which were designed for bimodal, near-infrared fluorescence-based (NIRF) and X-ray-based imaging. The developed FMs had poly(l-lactide-co-caprolactone)-based core-shell structures made of radiopaque (core) and fluorescent (shell) composites with a poly(l-lactide-co-caprolactone) matrix. The approved for human use contrast agents were utilized as fillers. Indocyanine green was applied to the shell material, whereas in the core materials, iohexol and barium sulfate were compared. Moreover, the possibility of tailoring the stability of the properties of the core materials by the addition of hydroxyapatite (HAp) was examined. The performed in situ (porcine tissue) and in vivo experiment (rat model) confirmed that the developed FMs possessed pronounced contrasting properties in NIRF and X-ray imaging. The presence of HAp improved the radiopacity of FMs at the initial state. It was also proved that, in iohexol-containing FMs, the presence of HAp slightly decreased the stability of contrasting properties, while in BaSO₄-containing ones, changes were less pronounced. A comprehensive material analysis explaining the differences in the stability of the contrasting properties was also presented. The tissue response around the FMs with composite cores was comparable to that of the FMs with a pristine polymeric core. The developed composite FMs did not cause serious adverse effects on the surrounding tissues even when irradiated in vivo. The developed FMs ensured good visibility for NIRF image-supported tumor surgery and the following X-ray image-guided radiotherapy. Moreover, this study replenishes a scanty report regarding similar biodegradable composite materials with a high potential for application.

E3 Ubiquitin Ligase SPL2 Is a Lanthanide-Binding Protein

The SPL2 protein is an E3 ubiquitin ligase of unknown function. It is one of only three types of E3 ligases found in the outer membrane of plant chloroplasts. In this study, we show that the cytosolic fragment of SPL2 binds lanthanide ions, as evidenced by fluorescence measurements and circular dichroism spectroscopy. We also report that SPL2 undergoes conformational changes upon binding of both Ca2+ and La3+, as evidenced by its partial unfolding. However, these structural rearrangements do not interfere with SPL2 enzymatic activity, as the protein retains its ability to auto-ubiquitinate in vitro. The possible applications of lanthanide-based probes to identify protein interactions in vivo are also discussed. Taken together, the results of this study reveal that the SPL2 protein contains a lanthanide-binding site, showing for the first time that at least some E3 ubiquitin ligases are also capable of binding lanthanide ions.

Pannexin-1 channel "fuels" by releasing ATP from bone marrow cells a state of sterile inflammation required for optimal mobilization and homing of hematopoietic stem cells

An efficient harvest of hematopoietic stem/progenitor cells (HSPCs) after pharmacological mobilization from the bone marrow (BM) into peripheral blood (PB) and subsequent proper homing and engraftment of these cells are crucial for clinical outcomes from hematopoietic transplants. Since extracellular adenosine triphosphate (eATP) plays an important role in both processes as an activator of sterile inflammation in the bone marrow microenvironment, we focused on the role of Pannexin-1 channel in the secretion of ATP to trigger both egress of HSPCs out of BM into PB as well as in reverse process that is their homing to BM niches after transplantation into myeloablated recipient. We employed a specific blocking peptide against Pannexin-1 channel and noticed decreased mobilization efficiency of HSPCs as well as other types of BM-residing stem cells including mesenchymal stroma cells (MSCs), endothelial progenitors (EPCs), and very small embryonic-like stem cells (VSELs). To explain better a role of Pannexin-1, we report that eATP activated Nlrp3 inflammasome in Gr-1+ and CD11b+ cells enriched for granulocytes and monocytes. This led to release of danger-associated molecular pattern molecules (DAMPs) and mitochondrial DNA (miDNA) that activate complement cascade (ComC) required for optimal egress of HSPCs from BM. On the other hand, Pannexin-1 channel blockage in transplant recipient mice leads to a defect in homing and engraftment of HSPCs. Based on this, Pannexin-1 channel as a source of eATP plays an important role in HSPCs trafficking.

A Novel Evidence That Mannan Binding Lectin (MBL) Pathway of Complement Cascade Activation is Involved in Homing and Engraftment of Hematopoietic Stem Progenitor Cells (HSPCs)

Delayed homing and engraftment of hematopoietic stem progenitor cells (HSPCs) or even failure to engraft at all is significant clinical problem after hematopoietic transplant. Therefore, in order to develop more efficient homing and engraftment facilitating strategies it is important to learn more about this process. Our team has postulated that myeloablative conditioning for transplantation induces in bone marrow (BM) microenvironment a state of sterile inflammation in which elements of innate immunity activated by radio- or chemotherapy conditioning for transplant play an important role. In frame with this claim we reported that a significant role in this process plays activation of complement cascade (ComC). Accordingly, mice that that lack a fifth component (C5) of ComC turned out to engraft poorly with normal syngeneic BM cells as compared to normal control animals. In extension of our previous studies we provide for first time evidence that mannan binding lectin (MBL) pathway is involved in activation of ComC in myeloablated transplant recipient BM and thus plays an important role in homing and engraftment of HSPCs. To support this MBL-KO mice show significant defect in hematopoietic reconstitution after hematopoietic transplantation. This correlates with a decrease in expression of stromal derived factor-1 (SDF-1) and impaired activation of Nlrp3 inflammasome in irradiated BM of these mice.

Deficiency of Selected Cathepsins Does Not Affect the Inhibitory Action of ECTV on Immune Properties of Dendritic Cells

Ectromelia virus (ECTV), an orthopoxvirus, undergoes productive replication in conventional dendritic cells (cDCs), resulting in the inhibition of their innate and adaptive immune functions. ECTV replication rate in cDCs is increased due to downregulation of the expression of cathepsins - cystein proteases that orchestrate several steps during DC maturation. Therefore, this study was aimed to determine if downregulation of cathepsins, such as B, L or S, disrupts cDC capacity to induce activating signals in T cells or whether infection of cDCs with ECTV further weakens their functions as antigen-presenting cells. Our results showed that cDCs treated with siRNA against cathepsin B, L and S synthesize similar amounts of pro-inflammatory cytokines and exhibit comparable ability to mature and stimulate alloreactive CD4⁺ T cells, as untreated wild type (WT) cells. Moreover, ECTV inhibitory effect on cDC innate and adaptive immune functions, observed especially after LPS treatment, was comparable in both cathepsin-silenced and WT cells. Taken together, the absence of cathepsins B, L and S has minimal, if any, impact on the inhibitory effect of ECTV on cDC immune functions. We assume that the virus-mediated inhibition of cathepsin expression in cDCs represents more a survival mechanism than an immune evasion strategy.

Obtaining Wisent early blastocyst in vitro is a basic for protection and creation of biodiversity for this threatened species

Wisent, or European bison (Bison bonasus), is listed as "vulnerable" on the IUCN Red List of Threatened Species and is therefore protected by international law. For the first time, a Wisent embryo has been obtained in vitro. This procedure creates a new opportunity to protect and increase Wisent reproductive potential and thereby opens new possibilities for the establishment of a controlled and broad reserve of the gene pool.

Modelling the Growth Rate of Listeria Monocytogenes in Cooked Ham Stored at Different Temperatures

Introduction

The purpose of the study was to determine and model the growth rates of L. monocytogenes in cooked cured ham stored at various temperatures.

Material and Methods

Samples of cured ham were artificially contaminated with a mixture of three L. monocytogenes strains and stored at 3, 6, 9, 12, or 15ºC for 16 days. The number of listeriae was determined after 0, 1, 2, 3, 5, 7, 9, 12, 14, and 16 days. A series of decimal dilutions were prepared from each sample and plated onto ALOA agar, after which the plates were incubated at 37ºC for 48 h under aerobic conditions. The bacterial counts were logarithmised and analysed statistically. Five repetitions of the experiment were performed.

Results

Both storage temperature and time were found to significantly influence the growth rate of listeriae (P > 0.01). The test bacteria growth curves were fitted to three primary models: the Gompertz, Baranyi, and logistic. The mean square error (MSE) and Akaike's information criterion (AIC) were calculated to evaluate the goodness of fit. It transpired that the logistic model fit the experimental data best. The natural logarithms of L. monocytogenes' mean growth rates from this model were fitted to two secondary models: the square root and polynomial.

Conclusion

Modelling in both secondary types can predict the growth rates of L. monocytogenes in cooked cured ham stored at each studied temperature, but mathematical validation showed the polynomial model to be more accurate.

Contamination of honey produced in the Republic of Kazakhstan with Clostridium botulinum

The paper presents the first results of a study on the contamination of honey produced in the Republic of Kazakhstan with C. botulinum spores known to pose a potential infection threat to infants. During microbiological analysis, culturing methods with TPGY, Willis-Hobbs agar, FAA agar connected with PCR, sequencing, and a mouse bioassay were used. The C. botulinum contamination rate of honey was relatively low as determined, at 0.91%. Nonetheless, the potential danger of the bacteria to childrens’ health should not be neglected

Mobile telecare system for intensive insulin treatment and patient education. First applications for newly diagnosed type 1 diabetic patients

The aim of the work was to develop and to evaluate the clinical efficiency of a mobile telecare system implementing teleconsultations based on the continuous transmission of patient-collected data directly to the physician and to the clinic. The developed TeleMed system consists of the patients' and the diabetologist's mobile units, the diabetologist's clinic and home workstations and the clinical server. The evaluation of the system was performed on a group of 13 newly diagnosed type 1 diabetic patients, during a single-arm study with 3-days run-in period, including a one-day intensive educational program, and 3-week study period, when the intensive insulin treatment was conducted without visits of patients to the clinic. The MBG dropped from 7.2 +/- 1.7 mmol/L before the study to 6.1 +/- 1.0 mmol/L in the third week of the study (P = 0.02) and the J-index from 30.2+/-19.2 to 19.7+/-7.7 (P = 0.04). Hemoglobin A1c decreased from 11.8 +/- 3.3% to 8.6 +/- 1.2% (P = 0.0002) in one month. The total daily insulin dose declined from 39.9 +/- 8.5 U to 20.0 +/- 9.6 U (P = 0.000006). The number of hypoglycemia episodes per patient per day decreased by 66% (P = 0.08) and the number of hyperglycemia episodes was reduced by 47% (P < 0.0001). The TeleMed facilitates not only efficient realization of the intensive insulin treatment but also successful remote patient training and education. No formal patient satisfaction study was done. However, some of the findings indicate that the application of the developed system increases patient self-confidence and quality of life.

Patterns of nuclear proto-oncogene expression during induced differentiation and proliferation of human B chronic lymphocytic leukaemia cells

Phorbol ester-induced differentiation of human B-chronic lymphocytic leukaemic cells was found to be preceded by a rapid transient induction in expression of the c-jun proto-oncogene, which paralleled that of c-fos. Induced expression of c-myc but not of c-fos/c-jun proto-oncogenes was markedly higher in a proliferating variant leukaemic cell population compared with that seen in typical lymphocytic leukaemia cells. These data suggest that the c-fos/c-jun nuclear oncogenes play a role in induced differentiation, whilst c-myc is more important in the proliferative response of B lymphocytes.

[Short-term subcutaneous infusion of insulin using a portable insulin pump in the treatment of diabetes mellitus]

The authors evaluated the effectiveness of treatment by means of constant subcutaneous insulin infusions (CPWI) in patients with diabetes staying in hospital. The infusions were made by means of portable insulin pumps (Microjet Bolus 1, Microjet Bolus 2 and Promedos E 1). The therapy was applied in a group of 15 patients with diabetes admitted to hospital because of symptoms of uncontrolled diabetes, among them 3 patients with diabetes freshly diagnosed. After 2-3 days of infusions 12 patients had glycaemia level approached to the physiological level. Only in one case of diabetes with significant resistance to insulin, the physicians were not able to control the diabetes. After 4-9 days of CPWI, patients who had been given conventional insulin injection had their insulin day demand reduced by 11-33%. In 4 cases the insulin demand had been established by means of Biostator GCIIS, after the introduction of the pumps the demand decreased by 40 +/- 5%, when the open loop system was applied. The above results suggest that the use of constant subcutaneous insulin infusion by means of a dosimeter may be recommended as a method of determining day demand for insulin, significantly shortening hospitalization period in patients with uncontrolled diabetes.

[Treatment of diabetes mellitus type 1 by long-term infusion of insulin]

In the article the authors evaluate the portable insulin pump, a prototype designed at the Institute of Biocybernetics and Biomedical Engineering of the Polish Academy of Sciences, and also Promedos E1 pump produced by Siemens in the therapy of patients with diabetes type 1 brittle. Two patients underwent therapy by means of continuous intravenous insulin infusions (CDWI) for two months, two other patients--(CPWI) for about five years. The authors made an evaluation of the two methods by counting mean blood glucose, value M according to Schlichtkrull and determining the level of glycosylated haemoglobin. By continuous infusions of insulin, the authors achieved better diabetes control than with the previous conventional therapy.

[Effect of insulin sensitivity on the occurrence of early-morning hyperglycemia in patients treated with insulin]

The study was aimed at elucidation of the effect of insulin-sensitivity on the occurring of the dawn phenomenon. Diabetic patients were investigated in whom the fasting glycaemia was often higher than 17 mmol/l (300 mg%). In all patients the euglycaemic state was maintained by a continuous i.v. infusion of insulin using a micropump and a changing infusion of glucose using Biostator. A slight increase in the insulin-sensitivity was seen in the early morning in 3 patients in whom the glucose consumption during the constant insulin infusion was 4 mg/min/kg b.w. Among 7 patients with lower glucose consumption in 6 a markedly low insulin-sensitivity was seen at down. The investigations allow to assume that the dawn phenomenon occurs mainly in patients with uncompensated diabetes which induces changes in insulin-sensitivity.