Assessment of Hematopoietic Response to Total Body Irradiation in a Rat Experimental Model.

BACKGROUND: Exposure to high doses of total body irradiation (TBI) may lead to the development of acute radiation syndrome (ARS). This study was conducted to establish an experimental rat model of TBI to assess the impact of different doses of TBI on survival and the kinetics of changes within the hematopoietic system in ARS. MATERIALS AND METHODS: In this study, 132 Lewis rats irradiated with a 5Gy or 7Gy dose served as experimental models to induce ARS and to evaluate the hematopoietic response of the bone marrow (BM) compartment. Animals were divided into 22 experimental groups (n = 6/group): groups 1-11 irradiated with 5Gy dose and groups 12-22 irradiated with 7Gy dose. The effects of TBI on the hematopoietic response were assessed at 2, 4, 6, 8 hours and 5, 10, 20, 30, 40, 60 and 90 days following TBI. Signs of ARS were evaluated by analyzing blood samples through complete blood count in addition to the clinical assessment. RESULTS: Groups irradiated with 5Gy TBI showed 100% survival, whereas after 7Gy dose, 1.6% mortality rate was observed. Assessment of the complete blood count revealed that lymphocytes were the first to be affected, regardless of the dose used, whereas an "abortive rise" of granulocytes was noted for both TBI doses. None of the animals exhibited signs of severe anemia or thrombocytopenia. All animals irradiated with 5Gy dose regained initial values for all blood cell subpopulations by the end of observation period. Body weight loss was reported to be dose-dependent and was more pronounced in the 7Gy groups. However, at the study end point at 90 days, all animals regained or exceeded the initial weight values. CONCLUSIONS: We have successfully established a rat experimental model of TBI. This study revealed a comparable hematopoietic response to the sublethal or potentially lethal doses of ionizing radiation. The experimental rat model of TBI may be used to assess different therapeutic approaches including BM-based cell therapies for long-term reconstitution of the hematopoietic and BM compartments allowing for comprehensive analysis of both the hematological and clinical symptoms associated with ARS.

Soluble and cell wall-bound phenolic acids and ferulic acid dehydrodimers in rye flour and five bread model systems: insight into mechanisms of improved availability.

BACKGROUND: The bread-making process influences bread components, including phenolics that significantly contribute to its antioxidant properties. Five bread model systems made from different rye cultivars were investigated to compare their impact on concentration of ethanol-soluble (free and ester-bound) and insoluble phenolics. RESULTS: Breads produced by a straight dough method without acid addition (A) and three-stage sourdough method with 12 h native starter preparation (C) exhibited the highest, genotype-dependent concentrations of free phenolic acids. Dough acidification by direct acid addition (method B) or by gradual production during prolonged starter fermentation (24 and 48 h, for methods D and E) considerably decreased their level. However, breads B were enriched in soluble ester-bound fraction. Both direct methods, despite substantial differences in dough pH, caused a similar increase in the amount of insoluble ester-bound fraction. The contents of phenolic fractions in rye bread were positively related to activity level of feruloyl esterase and negatively to those of arabinoxylan-hydrolysing enzymes in wholemeal flour. CONCLUSION: The solubility of rye bread phenolics may be enhanced by application of a suitable bread-making procedure with respect to rye cultivar, as the mechanisms of this process are also governed by a response of an individual genotype with specific biochemical profile.

Transplantation of Donor-Recipient Chimeric Cells Restores Peripheral Blood Cell Populations and Increases Survival after Total Body Irradiation-Induced Injury in a Rat Experimental Model.

Current therapies for acute radiation syndrome (ARS) involve bone marrow transplantation (BMT), leading to graft-versus-host disease (GvHD). To address this challenge, we have developed a novel donor-recipient chimeric cell (DRCC) therapy to increase survival and prevent GvHD following total body irradiation (TBI)-induced hematopoietic injury without the need for immunosuppression. In this study, 20 Lewis rats were exposed to 7 Gy TBI to induce ARS, and we assessed the efficacy of various cellular therapies following systemic intraosseous administration. Twenty Lewis rats were randomly divided into four experimental groups (n = 5/group): saline control, allogeneic bone marrow transplantation (alloBMT), DRCC, and alloBMT + DRCC. DRCC were created by polyethylene glycol-mediated fusion of bone marrow cells from 24 ACI (RT1a) and 24 Lewis (RT11) rat donors. Fusion feasibility was confirmed by flow cytometry and confocal microscopy. The impact of different therapies on post-irradiation peripheral blood cell recovery was evaluated through complete blood count, while GvHD signs were monitored clinically and histopathologically. The chimeric state of DRCC was confirmed. Post-alloBMT mortality was 60%, whereas DRCC and alloBMT + DRCC therapies achieved 100% survival. DRCC therapy also led to the highest white blood cell counts and minimal GvHD changes in kidney and skin samples, in contrast to alloBMT treatment. In this study, transplantation of DRCC promoted the recovery of peripheral blood cell populations after TBI without the development of GVHD. This study introduces a novel and promising DRCC-based bridging therapy for treating ARS and extending survival without GvHD.

Donor-Recipient Chimeric Cell Transplantation as the Bridging Therapy for Mitigating Total Body Irradiation-Induced Injury.

In recent years, cell-based therapies have emerged as a promising approach for mitigating radiation-induced injury. Acute radiation syndrome (ARS) results from exposure to high doses of radiation over a short time period. This study aimed to compare the efficacy of donor-recipient chimeric cell (DRCC) therapy in mitigating ARS induced by a total body irradiation (TBI) dose of 10 gray (Gy). Thirty irradiated Lewis rats were employed as ARS models to assess the efficacy of systemic-intraosseous transplantation of different cellular therapies in five experimental groups (n = 6/group): saline control, isogenic bone marrow transplantation (isoBMT), allogeneic BMT (alloBMT), DRCC, and alloBMT+DRCC. DRCC were created by polyethylene glycol-mediated fusion of bone marrow cells from 24 ACI (RT1a) and 24 Lewis (RT11) rat donors. The creation of DRCC and chimeric state was confirmed by flow cytometry (FC) and confocal microscopy (CM). Recovery of blood parameters was evaluated through complete blood count analysis. Graft-versus-host disease (GvHD) signs were assessed clinically and histopathologically using kidney, skin, and small intestine biopsies. FC and CM confirmed the fusion feasibility and the chimeric state of DRCC. A 100% mortality rate was observed in the saline control group, whereas a 100% survival was recorded following DRCC transplantation, correlating with significant recovery of peripheral blood parameters. In addition, no clinical or histopathological signs of GvHD were observed after DRCC and alloBMT+DRCC transplantation. These findings confirm efficacy of DRCC in mitigating GvHD, promoting hematopoietic recovery, and increasing animal survival following TBI-induced ARS. Moreover, tolerogenic and immunomodulatory properties of DRCC therapy support its feasibility for clinical applications. Therefore, this study introduces DRCC as an innovative bridging therapy for alleviating the acute effects of TBI, with broad implications for stem cell research and regenerative medicine.

Genetic variation in the extract viscosity of rye (Secale cereale L.) bread made from endosperm and wholemeal flour: impact of high-molecular-weight arabinoxylan, starch and protein.

BACKGROUND: To verify the viscous potential of rye bread made from population and hybrid cultivars, the overall extract viscosities (EVs) of endosperm and wholemeal breads (EBs and WMBs respectively) were assessed using extractants of different pH. Also, arabinoxylan-dependent EV (AX-EV) was determined after combined action of starch- and protein-degrading enzymes. RESULTS: The synergistic effect of a combination of α-amylase, amyloglucosidase and protease on EV was almost two times higher than the effects observed after single addition of each of them. However, water-extractable arabinoxylans (WE AXs) were the major contributors to EV. Unexpectedly, a decrease in the mean WE AX contents observed in the following order, WMB (31.7 g kg(-1) ) and EB (29.3 g kg(-1) ) of hybrid rye and WMB (28.8 g kg(-1) ) and EB (23.8 g kg(-1) ) of population rye, was accompanied by an increase in their AX-EVs (12, 21, 21 and 29 mPa s respectively). CONCLUSION: In some cases the structure of WE AXs is a more important determinant of AX-EV than their content in rye bread. Nevertheless, both factors influence AX-EV, which may reflect the viscosity of the human small intestine after rye bread consumption, related to some beneficial metabolic effects. Therefore AX-EV can be a preliminary parameter for selection towards high-viscosity bread.

Evidence of intermolecular associations of ß-glucan and high-molar mass xylan in a hot water extract of raw oat groat.

High molar mass (HM) ß-glucan present in oat products can reduce the risk of diet-related diseases, mainly owing to significantly increased digesta viscosity in human small intestine. To verify a research hypothesis that arabinoxylan (AX) present in oat water extract is associated with HM-ß-glucan and thus may influence its functionality, multi-detection HPSEC coupled with enzymatic hydrolysis, sugar and 1H NMR analyses were performed. Isolated cell wall polysaccharide fraction comprised branched AX (arabinose-to-xylose ratio, Ara/Xyl ~ 0.8) and arabinogalactan-protein (AG-P). Nevertheless, it contained (10%) unbranched HM-xylan subfraction (weight-average molar mass, Mw ~ 3153 kg/mol), which was aggregated with ß-glucan (Mw ~ 1029-1589 kg/mol) through its HM cellulose-like region. Of the two low molar mass-AXs (LM-AXs) isolated, the first having C(O)-3-monosubstituted and C(O)-2,3-disubstituted ß-d-xylopyranosyl residues was covalently interlinked to HM-xylan. The second highly feruloylated, containing C(O)-3- and C(O)-2-monosubstituted units, was tightly bound to AG-P with terminal and 5-linked α-L-arabinofuranosyl residues, and non-covalently associated with LM-ß-glucan subfraction.

Evaluation of the frequency of childhood hospitalization due to thermal injuries in the Provincial Polyclinical Hospital in Torun, Poland, 2007-2011.

INTRODUCTION: Burns constitute the most common and severe injuries suffered in childhood. OBJECTIVE: The study was aimed at providing a retrospective analysis of the etiology, location, extent and depth of burns, as well as treatment methods and length of hospital stay. MATERIAL AND METHODS: A retrospective analysis of 508 cases of children treated due to a thermal injury between 1 January 2007 31 December 2011 was conducted at the Department of Paediatrics, Urology and Paediatric Surgery, Children's Hospital, L. Rydygier Provincial Hospital in Torun, Poland. RESULTS: The sample group included more boys (58.9%) than girls (41.1%). The most numerous group comprised children aged 1-2 years (44.5%). Burns were largely suffered at home (91.9%). Injuries were largely caused by thermal burns (99.2%). Half of the children sustained injury to one body area (51.4%), while every third sufferer (37.9%) was affected by burns to body parts prone to trigger shock. Burns up to 5% of the Total Body Surface Area (TBSA) were suffered by half (51.2%) of the children. Most of the patients underwent conservative treatment (89.4%). CONCLUSIONS: Burns were mostly suffered by children at 1-2 years of age, with boys prevailing over girls. Injuries were largely suffered at the child's family home, in the afternoon or evening, while the child was in the care of the parents. Scalds, caused by hot liquid, constituted the most frequent type of injury. The most numerous group of affected children comprised burns to limb areas, and thorax with limbs, with the TBSA of up to 5%. The great majority of the patients underwent conservative treatment, with a hospitalization period of up to 3 days.

Association and structural diversity of hemicelluloses in the cell walls of rye outer layers: comparison between two ryes with opposite breadmaking quality.

Looking for potential quality indicators, which could be used in early selection of breeding materials, the structural features of cell wall arabinoxylans (AX) from outer layers of the grain (pooled shorts and bran fractions) were studied in two ryes with diverse breadmaking quality. The successive alkaline extraction of water-unextractable material with saturated Ba(OH)2, followed by water and 1 and 4 M NaOH, resulted in four purified fractions, Ba, BaH, 1Na, and 4Na, respectively, that became water soluble after their isolation. The AX present in these fractions constituted approximately 43, 12, 14, and 4% of their total amount recovered. Moreover, two xylan-enriched fractions, 1Na.P and 4Na.P (arabinose-to-xylose ratios, Ara/Xyl, of 0.07 and 0.19, respectively), were self-precipitated from both NaOH-extractable fractions. Polysaccharides of these fractions, containing mainly xylose, represented approximately 16 and 1% of AX recovered. In the BaH and 1Na, AX coexisted with beta-glucans, which predominated in the former protein-free fraction. On the contrary, hemicelluloses in the 1Na fraction were associated with protein as well. Further fractionation of the water-soluble materials by ammonium sulfate revealed that the parent AX populations in the Ba, BaH, and 1Na were composed of 3-4 subfractions with different degrees of substitution (Ara/Xyl of approximately 0.4, 0.8, and 1.1), whereas 4Na was almost totally built of highly substituted AX (Ara/Xyl of 1.1). Despite a comparable proportion of un-, mono-, and disubstituted xylopyranosyl residues in the chain of Ba(OH)2-extractable AX isolated from both ryes, the 1H NMR and Fourier transform infrared demonstrated the marked differences in their spectral profiles, suggesting different substitution patterns of these dominating polysaccharides. The high molecular weight population present in the Ba fraction also differentiated well two ryes with opposite breadmaking quality.

Cell wall fractions isolated from outer layers of rye grain by sequential treatment with alpha-amylase and proteinase: structural investigation of polymers in two ryes with contrasting breadmaking quality.

Recent studies have indicated that some structural features of arabinoxylans, the major cell wall polysaccharides, might be potential quality markers in the selection of rye breeding materials. To specify the most appropriate characteristics, the differences in the structure of cell wall components were studied in two ryes with high and low breadmaking qualities. Two cell wall fractions were isolated from the outer layers of the grain (pooled shorts and bran fractions) by a consecutive water extraction with alpha-amylase (WE-A) and proteinase K (WE-P). Polysaccharides predominated in the WE-A fraction (approximately 64%, mainly arabinoxylans). By contrast, the WE-P fraction contained mostly protein (approximately 63%), and its level of polysaccharides was relatively low (approximately 18%). The 1H NMR and sugar analysis of the ammonium sulfate precipitated subfractions revealed that the WE-A was built of four arabinoxylan populations with marked structural differences (arabinose-to-xylose ratios, Ara/Xyl, of approximately 0.3, 0.5, 0.8, and 1.2). Instead, the arabinoxylans present in the WE-P were generally enriched in disubstituted xylopyranosyl residues. The ratio of phenolic components to arabinose residues in the WE-P fraction (indicated by 1H NMR) and the proportion of polymers with the highest molecular weights in the WE-A fraction (revealed by HPSEC) distinguished well two ryes with diverse breadmaking qualities. Much less obvious differences between both ryes were observed in the ratio of amide I to amide II band intensities of FTIR spectra for the WE-P and in the level of phenolic acids and ferulic acid dehydrodimers for both cell wall preparations.

Structural features of arabinoxylans extracted with water at different temperatures from two rye flours of diverse breadmaking quality.

The water extractable (WE) arabinoxylans from two rye flours differing in baking quality were studied following sequential extraction with water at 4, 40, and 100 degrees C. Ammonium sulfate fractionation of the resulting WE fractions and subsequent analysis revealed substantial differences in the structure of the isolated materials. Furthermore, it allowed us to identify the factors contributing to arabinoxylan water extractability. Our results provide compelling evidence for the existence of separate polymers in rye WE arabinoxylans with different substitution degrees, ranging from quantitatively dominating, lowly substituted populations (arabinose to xylose ratio, Ara/Xyl approximately 0.5) to comparatively less abundant, highly substituted analogues (Ara/Xyl approximately 1.3). Generally, arabinoxylan water extractability was governed by the relative proportion of lowly and highly branched structures. A gradually increasing proportion of highly substituted populations was observed from cold to hot WE fractions. This was associated with the lower proportion of monosubstituted xylopyranosyl residues in the backbone, the higher proportion of disubstituted xylopyranosyl residues, and the higher level of substitution with feruloyl residues. Notable differences in the ratio of phenolic compounds to arabinose residues were observed between corresponding polymers isolated from rye flours of high and low baking quality, whereas the differences in their molecular weights were much less pronounced.

Heterogeneity in the fine structure of alkali-extractable arabinoxylans isolated from two rye flours with high and low breadmaking quality and their coexistence with other cell wall components.

The alkali extractable (AE) arabinoxylans from two rye flours differing in baking quality were studied following sequential extraction of water-unextractable and starch-free rye flour residue with saturated barium hydroxide solution, water and 1 M sodium hydroxide solution (Ba, BaH, and Na, respectively), and further fractionation of isolated fractions by ammonium sulfate precipitation. (1)H NMR and sugar analyses of AE subfractions provided evidence for the presence of lowly branched arabinoxylans (average arabinose-to-xylose ratio, Ara/Xyl approximately 0.5), containing mainly un- and monosubstituted xylopyranosyl residues (Xylp) in the chain. The proportion of this subfraction decreased from 50% in the Ba fraction to 35 and 17% in the Na and BaH fractions, respectively. Other subfractions, rich in both mono- and disubstituted Xylp, represented arabinoxylan populations with intermediate (Ara/Xyl approximately 0.8) and high substitution degree (Ara/Xyl approximately 1.1). The Ba and Na fractions contained phenolic compounds, whereas they were absent in the BaH fraction. The higher ratio of such phenolic compounds to arabinose (PhC/Ara) found in AE arabinoxylans from rye flour of inferior baking quality was one of the most pronounced differences between arabinoxylan populations from rye flours with high and low baking quality. The arabinoxylans from rye flour of high baking quality present in Ba and Na fractions had slightly higher apparent molecular weights (MWs) when compared to those from rye flour with low baking quality. The arabinoxylans present in the BaH fractions, characterized by the highest MWs, had similar MWs.

Mode of endosperm and wholemeal arabinoxylans solubilisation during rye breadmaking: genotypic diversity in the level, substitution degree and macromolecular characteristics.

Insight into solubilisation mechanisms of rye arabinoxylans during breadmaking is important for understanding the biochemical processes that affect bread attributes. Purified ethanol precipitated water-extractable arabinoxylans (WE-AX) and residual unextractable counterparts (WU-AX) were isolated from rye flours and resulting breads. While the endosperm flours had lower endoxylanase activities and higher arabinose-to-xylose ratios of WU-AX than those of corresponding wholemeals, there were not any significant differences between them in the mean amounts of WU-AX hydrolysed during breadmaking. Nevertheless, they were highly affected by rye cultivar used for breadmaking. On average, 42% and 36% of WU-AX were recovered in bread WE-AX fraction, causing its 11% and 8% increase, respectively for endosperm and wholemeal breads. Bread WE-AX, however, had lower molecular weights than those of starting flours, implying chains depolymerisation. Degree of AX solubilisation depends mainly on rye genotype used, determining combined effect of enzymatic and acid hydrolyses, associations and fine structure of AX.

Depolymerization degree of water-extractable arabinoxylans in rye bread: characteristics of inbred lines used for breeding of bread cultivars.

The water-extractable arabinoxylans (WE AXs) present in rye bread govern its viscous properties, which may be related to reduced risk of cardiovascular diseases and diabetes. Breads made from rye cultivars generally exhibit higher AX-dependent extract viscosities (Cyran, M. R.; Saulnier, L. Food Chemistry2012, 131, 667-676) when compared with those produced from inbred lines used for their breeding. To give further details about this trend, the WE AXs were isolated from breads of lines and structurally characterized by HPSEC and (1)H NMR spectroscopy. The extract viscosities of endosperm and whole-meal breads were usually comparable, in contrast to those made from rye cultivars with higher viscosity of endosperm bread. The WE AXs present in breads obtained from inbred lines were characterized by the higher degradation degrees than those in breads from cultivars, as indicated by their HPSEC-RI profiles. This was associated with considerably lower proportions of 2-Xylp in their backbones. Besides, a level of endoxylanase activity in flours from inbred lines was much higher than that in flours from cultivars. Breeding of hybrid rye cultivars for production of high-viscosity bread requires the proper components. They may be preliminarily selected from populations with high WE AX contents and relatively low levels of endoxylanase activity by using the overall viscosity test for starting flours. However, further measurement of AX-dependent extract viscosity in test breads made from such lines may verify their usefulness completely.

Structural characterization of feruloylated arabinoxylans and xylans released from water-unextractable cell walls of rye outer layers upon treatment with lichenase and cellulase.

Destarched and deproteinated water-unextractable material (WUM) of rye outer layers was sequentially treated with lichenase and cellulase to digest beta-glucans and a part of the cellulose. As a result, the polymeric cell-wall material (CWM) initially associated with these polysaccharides was released into solution (AXL and AXC for lichenase- and cellulase-extractable fractions, respectively). A portion of the material that self-aggregated during extractions was further solubilized with DMSO (XD and XD-P for the fraction left in the solution and that precipitated during dialysis, respectively). Arabinoxylans (AXs) recovered from these fractions were composed of populations with different degrees of substitution with alpha-l-arabinofuranosyl residues (Araf). Their counterparts present in the AXL and AXC fractions exhibited higher (0.60 and 0.75) arabinose-to-xylose ratios (Ara/Xyl) and represented 27% and 32% of the isolated AXs, respectively. The xylans of the XD and XD-P fractions had a very low Ara/Xyl ratio (0.16 and 0.09) and accounted for 23% and 18%, respectively. Based on the results of ammonium sulfate fractionation and sugar analysis, it has been shown that AXL consisted of AX subfractions having Ara/Xyl in a narrow range (0.50-0.66). By contrast, the cellulase-extractable AXs were characterized by the presence of the highly branched subfractions (Ara/Xyl of 1.00) as well. Quite unexpectedly, the higher amounts of ferulic acid (FA) were found in the cell-wall fractions enriched in xylans than in the AX-containing fractions. Furthermore, as demonstrated by (1)H NMR and Fourier transform infrared spectroscopy, xylans were substituted with alpha-d-glucuronopyranosyl residues (GlcpA).