Influence of feed provisioning prior to digesta sampling on precaecal amino acid digestibility in broiler chickens

A regression approach was applied to determine the influence of feed provisioning prior to digesta sampling on precaecal (pc) amino acid (AA) digestibility in broiler chickens. Soybean meal was used as an example test ingredient. Five feed-provisioning protocols were investigated, four with restricted provision and one with ad libitum provision. When provision was restricted, feed was provided for 30 min after a withdrawal period of 12 h. Digesta were sampled 1, 2, 4 and 6 h after feeding commenced. A diet containing 300 g maize starch/kg was prepared. Half or all the maize starch was replaced with soybean meal in two other diets. Average pc digestibility of all determined AA in the soybean meal was 86% for the 4 and 6-h protocols and 66% and 60% for the 2 and 1-h protocols, respectively. Average pc AA digestibility of soybean meal was 76% for ad libitum feed provision. Feed provisioning also influenced the determined variance. Variance in digestibility ranked in magnitude 1 h > ad libitum > 2 h > 6 h > 4 h for all AA. Owing to the considerable influence of feed-provisioning protocols found in this study, comparisons of pc AA digestibility between studies applying different protocols prior to digesta sampling must be treated with caution. Digestibility experiments aimed at providing estimates for practical feed formulation should use feed-provisioning procedures similar to those used in practice.

Effect of particle size distribution of maize and soybean meal on the precaecal amino acid digestibility in broiler chickens

1. Herein, it was investigated whether different particle size distributions of feed ingredients achieved by grinding through a 2- or 3-mm grid would have an effect on precaecal (pc) amino acid (AA) digestibility. Maize and soybean meal were used as the test ingredients. 2. Maize and soybean meal was ground with grid sizes of 2 or 3 mm. Nine diets were prepared. The basal diet contained 500 g/kg of maize starch. The other experimental diets contained maize or soybean meal samples at concentrations of 250 and 500, and 150 and 300 g/kg, respectively, instead of maize starch. Each diet was tested using 6 replicate groups of 10 birds each. The regression approach was applied to calculate the pc AA digestibility of the test ingredients. 3. The reduction of the grid size from 3 to 2 mm reduced the average particle size of both maize and soybean meal, mainly by reducing the proportion of coarse particles. Reducing the grid size significantly (P < 0.050) increased the pc digestibility of all AA in the soybean meal. In maize, reducing the grid size decreased the pc digestibility of all AA numerically, but not significantly (P > 0.050). The mean numerical differences in pc AA digestibility between the grid sizes were 0.045 and 0.055 in maize and soybean meal, respectively. 4. Future studies investigating the pc AA digestibility should specify the particle size distribution and should investigate the test ingredients ground similarly for practical applications.

Prececal amino acid digestibility of soybean cake in fast- and slow-growing broiler chickens

The objective of the present study was to determine whether there are differences in prececal amino acid digestibility between commonly used slow- and fast-growing broiler strains when the regression approach is applied. ISA J-275 and Ross 308 were selected as common representatives of slow- and fast-growing broiler strains, respectively. The experimental diets with soybean cake at levels of 0, 100, and 200 g/kg were offered for ad libitum consumption between 22 and 29 d post-hatch. Titanium dioxide was used as an indigestible marker. Each treatment was tested with six pens comprising 10 birds each. Digesta samples were collected on a pen basis from the distal two-thirds of the intestine section between Meckel's diverticulum and 2 cm anterior to the ileocecal-colonic junction. The prececal amino acid digestibility of soybean cake was calculated by linear regression simultaneously for both strains. There was no significant interaction between broiler strain and inclusion level of soybean cake with respect to the prececal CP and amino acid digestibility of complete diets; there was a significant strain effect for 5 out of the 16 measured amino acids. The prececal CP and amino acid digestibility of soybean cake did not differ significantly between strains and was numerically almost identical. The results of the present study provide evidence of the transferability between broiler strains of prececal amino acid digestibility data, determined using the regression approach, thus improving the accuracy of diet formulation without drawbacks.

Results of an international phosphorus digestibility ring test with broiler chickens

The objective of this ring test was to investigate the prececal phosphorus (P) digestibility of soybean meal (SBM) in broiler chickens using the trial protocol proposed by the World's Poultry Science Association. It was hypothesized that prececal P digestibility of SBM determined in the collaborating stations is similar. Three diets with different inclusion levels of SBM were mixed in a feed mill specialized in experimental diets and transported to 17 collaborating stations. Broiler chicks were raised on commercial starter diets according to station-specific management routine. Then they were fed the experimental diets for a minimum of 5 d before content of the posterior half of the ileum was collected. A minimum of 6 experimental replicates per diet was used in each station. All diets and digesta samples were analyzed in the same laboratory. Diet, station, and their interaction significantly affected (P < 0.05) the prececal digestibility values of P and calcium of the diets. The prececal P digestibility of SBM was determined by linear regression and varied among stations from 19 to 51%, with significant differences among stations. In a subset of 4 stations, the prececal disappearance of myo-inositol 1,2,3,4,5,6-hexakis (dihydrogen phosphate)-P; InsP6-P) also was studied. The prececal InsP6-P disappearance correlated well with the prececal P digestibility. We hypothesized that factors influencing InsP6 hydrolysis were main contributors to the variation in prececal P digestibility among stations. These factors were probably related to the feeding and housing conditions (floor pens or cages) of the birds in the pre-experimental phase. Therefore, we suggest that the World's Poultry Science Association protocol for the determination of digestible P be should extended to the standardization of the pre-experimental period. We also suggest that comparisons of P digestibility measurements among studies are made only with great caution until the protocol is more refined.

Effect of nitrogen fertilisation on the amino acid digestibility of different triticale genotypes in caecectomised laying hens

BACKGROUND

The influence of nitrogen fertilisation and genotype on the amino acid (AA) digestibility of triticale grain was investigated in caecectomised laying hens. Three genotypes, Grenado, EAW6002 and Lasko, were cultivated with and without nitrogen fertilisation at the end of the heading stage. The six triticale variants as well as a basal diet were each used to feed seven laying hens in a 7 × 7 Latin square design.

RESULTS

Nitrogen fertilisation influenced the digestibility of Cys, Glu, Phe and Ser in some triticale genotypes and reduced Ala, Ile, Lys, Met and Val digestibility in all genotypes (P < 0.05). Nitrogen fertilisation increased the concentration of all AAs in the grain. Consequently, the concentration of digestible AAs in the grains was increased for most AAs upon nitrogen fertilisation. Overall, Lys had the lowest digestibility, whereas that of Glu and Pro was the highest. For the triticale genotypes, the level of AA digestibility was highest for EAW6002 followed by Lasko and Grenado, with significant differences (P < 0.05) between genotypes for some but not all AAs.

CONCLUSION

The results indicated that the accuracy of the digestible AA supply for hen feeding might benefit from considering fertilisation and genotype-specific digestibility data in feed formulation. © 2016 Society of Chemical Industry.

Variation in chemical composition and physical characteristics of cereal grains from different genotypes

Genotypes of cereal grains, including winter barley (n = 21), maize (n = 27), oats (n = 14), winter rye (n = 22), winter triticale (n = 21) and winter wheat (n = 29), were assayed for their chemical composition and physical characteristics as part of the collaborative research project referred to as GrainUp. Genotypes of one grain species were grown on the same site, except maize. In general, concentrations of proximate nutrients were not largely different from feed tables. The coefficient of variation (CV) for the ether extract concentration of maize was high because the data pool comprised speciality maize bred for its high oil content. A subset of 8 barley, 20 rye, 20 triticale and 20 wheat samples was analysed to differ significantly in several carbohydrate fractions. Gross energy concentration of cereal grains could be predicted from proximate nutrient concentration with good accuracy. The mean lysine concentration of protein was the highest in oats (4.2 g/16 g N) and the lowest in wheat (2.7 g/16 g N). Significant differences were also detected in the concentrations of macro elements as well as iron, manganese, zinc and copper. Concentrations of arsenic, cadmium and lead were below the limit of detection. The concentration of lower inositol phosphates was low, but some inositol pentaphosphates were detected in all grains. In barley, relatively high inositol tetraphosphate concentration also was found. Intrinsic phytase activity was the highest in rye, followed by triticale, wheat, barley and maize, and it was not detectable in oats. Substantial differences were seen in the thousand seed weight, test weight, falling number and extract viscoelasticity characteristics. The study is a comprehensive overview of the composition of different cereal grain genotypes when grown on the same location. The relevance of the variation in composition for digestibility in different animal species will be subject of other communications.

Impact of genomic risk factors on outcome after hematopoietic stem cell transplantation for patients with chronic myeloid leukemia

BACKGROUND

Non-HLA gene polymorphisms have been shown to influence outcome after allogeneic hematopoietic stem cell transplantation. Results were derived from heterogeneous, small populations and their value remains a matter of debate.

DESIGN AND METHODS

In this study, we assessed the effect of single nucleotide polymorphisms in genes for interleukin 1 receptor antagonist (IL1RN), interleukin 4 (IL4), interleukin 6 (IL6), interleukin 10 (IL10), interferon (IFNG), tumor necrosis factor (TNF) and the cell surface receptors tumor necrosis factor receptor II (TNFRSFIB), vitamin D receptor (VDR) and estrogen receptor alpha (ESR1) in a homogeneous cohort of 228 HLA identical sibling transplants for chronic myeloid leukemia. Three good predictors of overall survival, identified via statistical methods including Cox regression analysis, were investigated for their effects on transplant-related mortality and relapse. Predictive power was assessed after integration into the established European Group for Blood and Marrow Transplantation (EBMT) risk score.

RESULTS

Absence of patient TNFRSFIB 196R, absence of donor IL10 ATA/ACC and presence of donor IL1RN allele 2 genotypes were associated with increased transplantation-related mortality and decreased survival. Application of prediction error and concordance index statistics gave evidence that integration improved the EBMT risk score.

CONCLUSIONS

Non-HLA genotypes were associated with survival after allogeneic hematopoietic stem cell transplantation. When three genetic polymorphisms were added into the EBMT risk model they improved the goodness of fit. Non-HLA genotyping could, therefore, be used to improve donor selection algorithms and risk assessment prior to allogeneic hematopoietic stem cell transplantation.

Cytokine profiles of cord and adult blood leukocytes: differences in expression are due to differences in expression and activation of transcription factors

BACKGROUND

Stem cell transplantation as therapy for hematological disorders is often hampered by severe graft-versus-host-disease. This may be reduced by umbilical cord blood transplantation, an effect that has been attributed to qualitative differences between neonatal and adult T cells. We compared levels of secreted proteins and cytokine mRNA induced in cord blood leukocytes (CBL) and adult blood leukocytes (ABL) by various stimuli.

RESULTS

While interleukin-2 (IL-2) levels were similar in CBL and ABL, there was less induction of the Th1 cytokine interferon-gamma in CBL. Production of the Th2 cytokines IL-4, IL-5, and IL-13 and the hematopoietic cytokine IL-3 was much lower in CBL versus ABL after T-cell receptor-mediated stimulation, whereas production of GM-CSF was comparable in the 2 cell types. The lower levels of Th1 and Th2 cytokines were maintained in CBL during a 4-day time-course study, while after 12 hours IL-3 and GM-CSF reached in CBL levels similar to those in ABL. For all cytokines except IFN gamma, the IC50 values for inhibition by cyclosporin A were similar in ABL and CBL. In contrast, there was less expression and activation of transcription factors in CBL. Activation of NF-kappaB by TPA/ionomycin was detected in ABL but not CBL. Furthermore, there was less expression of the Th subset-specific transcription factors T-bet and c-maf in CBL versus ABL, whereas GATA-3 expression was similar. Expression of T-bet and c-maf correlated with expression of the Th1 and Th2 cytokines, respectively. Time course experiments revealed that T-bet expression was stimulated in both cell types, whereas c-maf and GATA-3 were induced only in ABL.

CONCLUSION

The diminished capability of CBL to synthesize cytokines is probably due to decreased activation of NF-kappaB, whereas differences in Th subsets are due to differences in regulation of Th lineage-specific transcriptions factors. We propose that the reduced incidence and severity of GvHD after allogeneic transplantation of umbilical CB cells is due to lesser activation of specific transcription factors and a subsequent reduction in production of certain cytokines.

Quantitative expression analysis of HHV-6 cell receptor CD46 on cells of human cord blood, peripheral blood and G-CSF mobilised leukapheresis cells

Human herpesvirus-6 (HHV-6) can infect blood cells and thereby may inhibit hematopoietic stem and progenitor cell expansion and differentiation. In this context, it has been discussed if early progenitor cells can be infected by HHV-6. CD46 was identified as one possible cellular surface receptor for HHV-6. The study presented here had been done to get insight into the susceptibility of various leukocyte subpopulations to HHV-6 (including early hematopoietic progenitors) by determining the amount of CD46 molecules expressed on their surfaces. Human cord blood cells, peripheral blood cells and G-CSF mobilised progenitor cells were analysed by flow cytometry. CD46 molecule number per cell was determined and compared to calibration beads conjugated with known ratio of PE per bead. Highest CD46 expression was detected on B- lymphocytes, whereas T-lymphocytes only showed about half of the amount found on B cells. Hematopoietic progenitors also carried CD46 at intermediate levels. Unexpectedly, CD46 expression on progenitors from G-CSF mobilised leukapheresis products was approximately 20% of that found on comparable cells from untreated cord blood. In conclusion, hematopoietic progenitor cells express CD46 on their surface, thereby fulfilling a basic requirement for the susceptibility of HHV-6 infection.

Activity of thalidomide in patients with platinum-refractory germ-cell tumours

The aim of this study was assess the activity of thalidomide in patients with progressive relapsed or platinum-refractory germ-cell tumours (GCT). Between April 2002 and January 2003, 15 patients with inoperable progressive GCT were treated with escalated daily doses of 200-600 mg thalidomide. All patients had failed first-line and salvage chemotherapy with a median of 6 (range 4-12) cisplatin-based treatment cycles, 13/15 (87%) patients had received high-dose chemotherapy (HDCT) and 8/15 (53%) patients were considered platinum-refractory or absolute refractory; 8/15 (53%) patients had previously received other palliative chemotherapy regimens. No patient achieved a complete remission (CR) or partial remission (PR). However, 5/15 (33%) patients achieved serological PR and 1 additional patient had stable disease for 3 months. The median duration of remissions was 3 months (range 2-12 months) including 2 patients with a progression-free survival of 9 and 12 months. Responses occurred mainly in patients with a low tumour burden, slow disease progression and alpha-foetoprotein (AFP) elevations. Responses to thalidomide were independent from platinum-sensitivity. Toxicity was mild, with lethargy and constipation in the majority of patients. Skin rash grade II developed in 2 patients and peripheral neurotoxicity grade II/III developed in 4 patients. One responding patient died suddenly from an unknown cause. It is concluded that thalidomide shows single-agent activity in patients with heavily pre-treated GCT, AFP elevations and slowly progressive disease.

Evaluation of prognosis in relapsed germ cell tumors: Identification of patients who profit from high dose chemotherapy (HDCT)

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Background: To identify prognostic variables in patients (pts) with metastatic germ cell tumors (GCT) and relapse or progression after first-line chemotherapy (FLC). Methods: In our database of 257 GCT pts treated with HDCT, 176/257 (67.4%) pts with first relapse or progression were identified. All patients had received platinum-based FLC. As salvage treatment all pts had received 1–3 cycles of conventional-dose salvage chemotherapy (CDCT) followed by one cycle HDCT. First, pts were retrospectively classified according to a prognostic score developed for CDCT by Fossa et al. [Br J Cancer 1999,80:1392], based on variables present at the time of relapse. Thereafter, a multivariate analysis was performed to evaluate further risk factors. Results: After a median follow up of 9 years the event-free survival (EFS) and overall survival (OS) for all 176 patients was 34% and 38%, respectively. Patients with good (n= 100/176, 57%) and poor (n = 76/176, 43%) prognosis in accordance to Fossa et al. showed an EFS of 41% and 26% (p < 0.01) and an OS of 47% and 26% (p < 0.01). Thus, in contrast to the data of Fossa et al, long-term survival could be demonstrated even in the poor prognosis subset. In the multivariate analysis, the level of elevated tumor markers alfa-fetoprotein and human chorionic gonadotrophin (p < 0.01), the presence of extrapulmonal visceral metastases (p < 0.01) and refractoriness to cisplatin (p < 0.01) adversely influenced OS after HDCT significantly. Based on these latter factors three different groups with increasingly poor OS could be identified: none factor (n = 39/176, 22%) 4 year OS of 59%, one factor (n = 78/176, 44%) 6 year OS of 42% and more than one factor (n = 59/176, 34%) 4 year OS of 17%. Conclusion: In pts with first relapse or progression after platinum-based FLC high serum tumor markers, presence of extrapulmonal visceral metastases and cisplatin refractoriness proved to be independent prognostic significance for OS after salvage HDCT. However, even in the poor prognosis subset long-term survival could be demonstrated.

No significant financial relationships to disclose.

Infections with human herpesvirus 6 variant B delay platelet engraftment after allogeneic haematopoietic stem cell transplantation

The clinical significance of human herpesvirus (HHV-6) infections after allogeneic stem cell transplantation (SCT) remains controversial. We analysed cryoconserved plasma samples from 82 patients after allogeneic SCT by quantitative polymerase chain reaction for HHV-6 variants A and B. Platelet engraftment was delayed in patients with HHV-6B infections but not with HHV-6A infections detected before day +28. In multivariate analysis early HHV-6B infections and the type of conditioning were associated with platelet engraftment. In conclusion, the two variants of HHV-6 should be studied separately; early infections with HHV-6B may contribute to delayed platelet engraftment after allogeneic SCT.

Sustained complete molecular remissions after treatment with imatinib-mesylate in patients with failure after allogeneic stem cell transplantation for chronic myelogenous leukemia: results of a prospective phase II open-label multicenter study

PURPOSE

In the era of molecular therapy of chronic myelogenous leukemia (CML) applying BCR-ABL tyrosine kinase inhibitors, the usefulness of molecular end points, in particular, quantitative polymerase chain reaction (PCR) for BCR-ABL in monitoring responses has been broadly accepted. Therefore, we have designed a prospective phase II trial in CML, which, for the first time, evaluated the feasibility and safety of molecular end points as surrogate markers to guide through a stratified treatment algorithm within a multicenter trial.

PATIENTS AND METHODS

As a clinical model, we adopted minimal residual disease (MRD) found in relapse after allogeneic stem cell transplantation (SCT) in CML. Forty-four patients were enrolled and received the BCR-ABL tyrosine kinase inhibitor imatinib (IM) at a starting dose of 400 mg/d. The quality of molecular responses achieved then decided on discontinuation of IM or dose escalation up to 800 mg/d, and finally, on application of donor lymphocyte infusions. Results Seventy percent of patients achieved a complete molecular response (CMR), defined as nested PCR-negativity for BCR-ABL in three consecutive samples. Interestingly, in four out of 10 patients who discontinued IM, CMR was durable even after cessation of IM with a median follow-up of 494 days. This suggests the possibility of long-term tumor control in a subset of patients.

CONCLUSION

The treatment strategy showed that IM treatment was well-tolerated and highly efficacious in MRD after allogeneic SCT. Moreover, this study demonstrated that evaluation of a molecular end point within a multicenter trial can be a safe and effective tool for clinical decision making.

A randomised trial of high-dose chemotherapy in the salvage treatment of patients failing first-line platinum chemotherapy for advanced germ cell tumours

BACKGROUND

Incomplete remission or relapse from first-line chemotherapy has poor prognosis in male germ cell tumour patients. This phase III randomised trial compares conventional salvage to high-dose-intensification chemotherapy.

PATIENTS AND METHODS

Between February 1994 and September 2001, 280 patients from 43 institutions in 11 countries, were randomly assigned to receive either four cycles of cisplatin, ifosfamide and etoposide (or vinblastine) (arm A), or three such cycles followed by high-dose carboplatin, etoposide and cyclophosphamide (CarboPEC) with haematopoietic stem cell support (arm B).

RESULTS

Similar complete and partial response rates were observed in both treatment arms (56%; 95% CI 50% to 62%). There were 3% and 7% toxic deaths in arms A and B, respectively. No significant improvements with CarboPEC were observed in either 3-year event-free survival (35% versus 42%, P=0.16) or overall survival (53%; 95% CI 46% to 59%). Complete responders with CarboPEC had a significant improvement in disease-free survival (55% versus 75% at 3 years, P <0.04).

CONCLUSIONS

The single cycle of high-dose salvage chemotherapy after three cycles of standard dose chemotherapy had no effect on treatment outcomes. These results suggest that data from uncontrolled studies should not be used to justify routine use of a toxic and expensive treatment without confirmation in a randomised trial.

After major ABO-mismatched allogeneic hematopoietic progenitor cell transplantation, erythroid engraftment occurs later in patients with donor blood group A than donor blood group B

BACKGROUND

Isohemagglutinins directed against the donor blood group frequently delay erythroid engraftment after major ABO-mismatched allogeneic hematopoietic progenitor cell transplantation (HPCT). Graft-versus-host reactions are capable of accelerating the clearance of isohemagglutinins. Whether immunogenicity of the A- and B-antigen is important in this process is unknown.

PATIENTS AND METHODS

Data of 807 patients from three centers were screened for patients with major or bidirectionally ABO-mismatched donors. Clinical data and red blood cell (RBC) transfusion support were analyzed retrospectively.

RESULTS

A total of 158 patients with major or bidirectionally mismatched donors were identified. After major mismatched HPCT, patients with anti-A directed against the donor blood group required RBC transfusion support for a median of 109 days (range, 0-324 days) compared to 21 days (range, 2-98 days) for patients with anti-B directed against donor blood group (log-rank test, p = 0.0001). Other risk factors associated with prolonged RBC transfusion support in univariate analysis were age (p = 0.024), cytomegalovirus infection (p = 0.016), hemolytic anemia (p = 0.027), and chronic bleeding disorders (p = 0.038). The independent influence of donor blood group and recipient age were confirmed in a multivariate analysis.

CONCLUSION

These results indicate that the immunogenicity of the ABO antigen plays an important role for the kinetics of erythroid engraftment after ABO-mismatched HPCT.

Second-line high-dose chemotherapy in patients with mediastinal and retroperitoneal primary non-seminomatous germ cell tumors: the EBMT experience

BACKGROUND

Results of second-line chemotherapy in patients with extragonadal non-seminomatous germ cell tumor (NSGCT) appear inferior to results in testicular NSGCT. Patients with retroperitoneal NSGCT achieve a comparable long-term survival rate of 30%, but the salvage rates of patients with mediastinal primary are less than 10%. We conducted a retrospective analysis on patients with mediastinal and retroperitoneal NSGCT treated with second-line high-dose chemotherapy (HDCT) registered with the European Group for Blood and Marrow Transplantation (EBMT).

PATIENTS AND METHODS

Between 1987 and 1999, 59 registered patients with retroperitoneal (n=37) and mediastinal (n=22) primary NSGCT, median age 28 years (range 18-60), were treated with second-line HDCT. All had received cisplatin-containing chemotherapy as first-line treatment.

RESULTS

Toxic death occurred in three cases (5%). With a median follow-up of 58 months (range 14-114), 18/59 patients (30%) continue to be disease-free. Of three patients who had a disease recurrence after HDCT, one patient achieved a disease-free status with further chemotherapy and surgery. In total, 19 patients (32%) are currently disease-free. Sixteen of 37 patients (43%) with retroperitoneal NSGCT, and three of 22 patients (14%) with mediastinal NSGCT are currently alive and disease-free.

CONCLUSIONS

Second-line HDCT might represent a possible option for patients with retroperitoneal primary NSGCT. New salvage strategies are needed for patients with mediastinal NSGCT.

Reference gene selection for quantitative real-time PCR analysis in virus infected cells: SARS corona virus, Yellow fever virus, Human Herpesvirus-6, Camelpox virus and Cytomegalovirus infections

Ten potential reference genes were compared for their use in experiments investigating cellular mRNA expression of virus infected cells. Human cell lines were infected with Cytomegalovirus, Human Herpesvirus-6, Camelpox virus, SARS coronavirus or Yellow fever virus. The expression levels of these genes and the viral replication were determined by real-time PCR. Genes were ranked by the BestKeeper tool, the GeNorm tool and by criteria we reported previously. Ranking lists of the genes tested were tool dependent. However, over all, β-actin is an unsuitable as reference gene, whereas TATA-Box binding protein and peptidyl-prolyl-isomerase A are stable reference genes for expression studies in virus infected cells.