JAK2V617F drives gut microbiota differences in patients with myeloproliferative neoplasms

BACKGROUND

Essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (MF) are myeloproliferative neoplasms (MPN). Inflammation is involved in the initiation, progression, and symptomology of the diseases. The gut microbiota impacts the immune system, infection control, and steady-state hematopoiesis.

METHODS

We analyzed the gut microbiota of 227 MPN patients and healthy controls (HCs) using next-generation sequencing. We expanded our previous results in PV and ET patients with additional PV, pre-MF, and MF patients which allowed us to compare MPN patients collectively, MPN sub-diagnoses, and MPN mutations (separately and combined) vs. HCs (N = 42) and compare within MPN sub-diagnoses and MPN mutation.

RESULTS

MPN patients had a higher observed richness (median, 245 [range, 49-659]) compared with HCs (191.5 [range, 111-300; p = .003]) and a lower relative abundance of taxa within the Firmicutes phylum; for example, Faecalibacterium (6% vs. 14%, p < .001). The microbiota of CALR-positive patients (N = 30) resembled that of HCs more than that of patients with JAK2V617F (N = 177). In JAK2V617F-positive patients, only minor differences in the gut microbiota were observed between MPN sub-diagnoses, illustrating the importance of this mutation.

CONCLUSION

The gut microbiota in MPN patients differs from HCs and is driven by JAK2V617F, whereas the gut microbiota in CALR patients resembles HCs more.

COVID-19 severity in patients with chronic lymphocytic leukemia treated with venetoclax: a single-center observational cohort study

Patients with chronic lymphocytic leukemia (CLL) are at high risk of developing severe COVID-19. The present study was undertaken to elucidate COVID-19 related morbidity and mortality in CLL patients treated with venetoclax. We present a single-center study of 108 patients with small lymphocytic lymphoma or CLL treated with venetoclax. Primary outcome was 30-day COVID-19 mortality. Secondary outcomes included COVID-19 severity and hospitalization rate. Forty-eight (44%) patients had PCR-verified SARS-COV-2 between March 2020 and January 2023. Thirty-six patients (75%) presented with asymptomatic/mild COVID-19 and 12 (25%) with severe/critical disease. The hospitalization rate was 46% with a 30-day mortality rate of only 4% and severe comorbidities as the primary cause of death. COVID-19 severity and mortality were similar before and during the Omicron era. High CIRS-scores (P < 0.02) and thrombocytopenia (P < 0.01) were more frequent in patients with severe/critical disease. In real-world data, most venetoclax treated patients presented with mild COVID-19. Hospitalization and mortality rates were low compared to data of general CLL populations. Our data indicate that venetoclax was a safe treatment option for CLL patients during the pandemic.

Neutrophil-to-lymphocyte ratio and all-cause mortality with and without myeloproliferative neoplasms-a Danish longitudinal study

The neutrophil-to-lymphocyte ratio(NLR) is increased in chronic inflammation and myeloproliferative neoplasms (MPN). We hypothesize that NLR is associated with all-cause mortality and mortality by comorbidity burden in the general population and individuals with MPN. We included 835,430 individuals from The Danish General Suburban Population Study, general practitioners, and outpatient clinics. We investigated NLR on mortality stratified by prevalent and incident MPN, essential thrombocythemia (ET), polycythemia vera (PV), myelofibrosis (MF), comorbidity burden (CCI-score), and the Triple-A risk score using hazard ratio (HR) and 95% confidence interval (95%CI). NLR 1-1.9 was the reference level. During a median follow-up of 11.2 years, 197,802 deaths were recorded. All-cause mortality increased for a stepwise increasing NLR with a HR (95%CI) for NLR ≥ 6 of 2.06(2.03-2.09) for the whole population and 2.93(2.44-3.50) in prevalent MPN. ET, PV, and MF had a HR (95%CI) for NLR ≥ 2 of 2.14(1.71-2.69), 2.19(1.89-2.54), and 2.31(1.91-2.80). Results were similar for incident MPN. Mortality was higher for stepwise increasing NLR and CCI-score(pinteraction < 2×10-16), with a HR for NLR ≥ 6 of 2.23(2.17-2.29), 4.10(4.01-4.20), and 7.69(7.50-7.89), for CCI-score 0, 1-2, or ≥3. The Triple-A risk score demonstrated alignment with NLR. Increasing NLR and comorbidity burden were associated with lower survival in individuals without MPN but were even worse in prevalent and incident MPN, ET, PV, and MF.

Proof of concept of triple COMBI therapy to prohibit MPN progression to AML

Patients with accelerated or blast phase myeloproliferative neoplasms have a dismal prognosis. The report by de Castro et al. provides important information on the rationale and prospect for a novel therapeutic approach combining interferon-alpha2 with 5-azacytidine and a JAK1-2 inhibitor (ruxolitinib) to be explored in well-designed clinical trials. Commentary on: Castro et al. Ratio of stemness to interferon signalling as a biomarker and therapeutic target of myeloproliferative neoplasm progression to acute myeloid leukaemia. Br J Haematol 2024;204:206-220.

Whole blood transcriptional profiling reveals highly deregulated atherosclerosis genes in Philadelphia-chromosome negative myeloproliferative neoplasms

BACKGROUND

The Philadelphia-negative chronic myeloproliferative neoplasms (MPNs) are associated with a huge comorbidity burden, including an increased risk of cardiovascular diseases. Recently, chronic inflammation has been suggested to be the driving force for clonal evolution and disease progression in MPN but also potentially having an impact upon the development of accelerated (premature) atherosclerosis.

OBJECTIVES

Since chronic inflammation, atherosclerosis, and atherothrombosis are prevalent in MPNs and we have previously shown oxidative stress genes to be markedly upregulated in MPNs, we hypothesized that genes linked to development of atherosclerosis might be highly deregulated as well.

METHODS

Using whole blood gene expression profiling in patients with essential thrombocythemia (ET; n = 19), polycythemia vera (PV; n = 41), or primary myelofibrosis (PMF; n = 9), we herein for the first time report aberrant expression of several atherosclerosis genes.

RESULTS

Of 84 atherosclerosis genes, 45, 56, and 46 genes were deregulated in patients with ET, PV, or PMF, respectively. Furthermore, BCL2L1, MMP1, PDGFA, PTGS1, and THBS4 were progressively significantly upregulated and BCL2 progressively significantly downregulated from ET over PV to PMF (all FDR <0.05).

CONCLUSIONS

We have for the first time shown massive deregulation of atherosclerosis genes in MPNs, likely reflecting the inflammatory state in MPNs in association with in vivo activation of leukocytes, platelets, and endothelial cells being deeply involved in the atherosclerotic process.

JAK2V617F mutation is highly prevalent in patients with ischemic stroke: a case-control study

Ischemic stroke has a high recurrence rate despite treatment. This underlines the significance of investigating new possible cerebrovascular risk factors, such as the acquired gene mutation JAK2V617F found in 3.1% of the general population. We aimed to investigate the prevalence of the JAK2V617F mutation in a population with ischemic stroke compared with that in matched controls. We enrolled 538 consecutive Danish patients with ischemic stroke (mean age, 69.5 ± 10.9 years; 39.2% female) within 7 days of symptom onset. Using multiple-adjusted conditional logistic regression analysis, we compared the prevalence of JAK2V617F with that in age- and sex-matched controls free of ischemic cerebrovascular disease (ICVD) from the Danish General Suburban Population Study. DNA was analyzed for JAK2V617F mutation using sensitive droplet digital polymerase chain reaction in patients and controls. Of the 538 patients with ischemic stroke, 61 (11.3%) had JAK2V617F mutation. There were no differences in patient demographics or cerebrovascular comorbidities between the patients with and without mutations. Patients with ischemic stroke were more likely to have the JAK2V617F mutation than matched controls, in whom the JAK2V617F prevalence was 4.4% (odds ratio, 2.37; 95% confidence interval, 1.57-3.58; P < .001). A subanalysis stratified by smoking history revealed that the association was strongest in current smokers (odds ratio, 4.78; 95% confidence interval, 2.22-10.28; P < .001). Patients with ischemic stroke were 2.4 times more likely to have the JAK2V617F mutation than matched controls without ICVD when adjusting for other cerebrovascular risk factors. This finding supports JAK2V617F mutation as a novel cerebrovascular risk factor.

Pronounced gut microbiota signatures in patients with JAK2V617F-positive essential thrombocythemia

Essential thrombocythemia (ET) is part of the Philadelphia chromosome-negative myeloproliferative neoplasms. It is characterized by an increased risk of thromboembolic events and also to a certain degree hypermetabolic symptoms. The gut microbiota is an important initiator of hematopoiesis and regulation of the immune system, but in patients with ET, where inflammation is a hallmark of the disease, it is vastly unexplored. In this study, we compared the gut microbiota via amplicon-based 16S rRNA gene sequencing of the V3-V4 region in 54 patients with ET according to mutation status Janus-kinase 2 (JAK2V617F)-positive vs JAK2V617F-negative patients with ET, and in 42 healthy controls (HCs). Gut microbiota richness was higher in patients with ET (median-observed richness, 283.5; range, 75-535) compared with HCs (median-observed richness, 191.5; range, 111-300; P < 0.001). Patients with ET had a different overall bacterial composition (beta diversity) than HCs (analysis of similarities [ANOSIM]; R = 0.063, P = 0.004). Patients with ET had a significantly lower relative abundance of taxa within the Firmicutes phylum compared with HCs (51% vs 59%, P = 0.03), and within that phylum, patients with ET also had a lower relative abundance of the genus Faecalibacterium (8% vs 15%, P < 0.001), an important immunoregulative bacterium. The microbiota signatures were more pronounced in patients harboring the JAK2V617F mutation, and highly similar to patients with polycythemia vera as previously described. These findings suggest that patients with ET may have an altered immune regulation; however, whether this dysregulation is induced in part by, or is itself inducing, an altered gut microbiota remains to be investigated. IMPORTANCE Essential thrombocythemia (ET) is a cancer characterized by thrombocyte overproduction. Inflammation has been shown to be vital in both the initiation and progression of other myeloproliferative neoplasms, and it is well known that the gut microbiota is important in the regulation of our immune system. However, the gut microbiota of patients with ET remains uninvestigated. In this study, we characterized the gut microbiota of patients with ET compared with healthy controls and thereby provide new insights into the field. We show that the gut microbiota of patients with ET differs significantly from that of healthy controls and the patients with ET have a lower relative abundance of important immunoregulative bacteria. Furthermore, we demonstrate that patients with JAK2V617F-positive ET have pronounced gut microbiota signatures compared with JAK2V617F-negative patients. Thereby confirming the importance of the underlying mutation, the immune response as well as the composition of the microbiota.

Revisiting Circulating Extracellular Matrix Fragments as Disease Markers in Myelofibrosis and Related Neoplasms

Philadelphia chromosome-negative chronic myeloproliferative neoplasms (MPNs) arise due to acquired somatic driver mutations in stem cells and develop over 10-30 years from the earliest cancer stages (essential thrombocythemia, polycythemia vera) towards the advanced myelofibrosis stage with bone marrow failure. The JAK2V617F mutation is the most prevalent driver mutation. Chronic inflammation is considered to be a major pathogenetic player, both as a trigger of MPN development and as a driver of disease progression. Chronic inflammation in MPNs is characterized by persistent connective tissue remodeling, which leads to organ dysfunction and ultimately, organ failure, due to excessive accumulation of extracellular matrix (ECM). Considering that MPNs are acquired clonal stem cell diseases developing in an inflammatory microenvironment in which the hematopoietic cell populations are progressively replaced by stromal proliferation-"a wound that never heals"-we herein aim to provide a comprehensive review of previous promising research in the field of circulating ECM fragments in the diagnosis, treatment and monitoring of MPNs. We address the rationales and highlight new perspectives for the use of circulating ECM protein fragments as biologically plausible, noninvasive disease markers in the management of MPNs.

Case Report: First longitudinal study of a patient with CALR positive clonal hematopoiesis of indeterminate potential developing into pre-fibrotic myelofibrosis

Initial diagnosis of overt myeloproliferative neoplasms (MPNs) represents the juncture during clonal evolution when symptoms or complications prompt an afflicted individual to seek medical attention. In 30-40% of the MPN subgroups essential thrombocythemia (ET) and myelofibrosis (MF), somatic mutations in the calreticulin gene (CALR) are drivers of the disease resulting in constitutive activation of the thrombopoietin receptor (MPL). In the current study, we describe a healthy CALR mutated individual during a 12 year follow-up from initial identification of CALR clonal hematopoiesis of indeterminate potential (CHIP) to the diagnosis of pre-MF. The pre-diagnostic exponential development dynamics of the malignant clone demonstrated close correlation with the platelet counts, neutrophil-to-lymphocyte (NLR) ratio, and inversely correlated to hemoglobin and erythrocyte counts. Backward extrapolation of the growth rate indicated the potential for discovery of the malignant clone many years prior to presentation of overt disease, opening a window of opportunity for early treatment intervention. We did not find any additional mutations associated with MPNs and the current case report provides novel information regarding the development of a driver mutation and the association with blood cell counts prior to clinical manifestation of symptoms suggesting that pre-diagnostic dynamics may supplement future diagnostic criteria for early diagnosis and intervention in MPN patients.

A novel integrated biomarker index for the assessment of hematological responses in MPNs during treatment with hydroxyurea and interferon-alpha2

BACKGROUND

Conventional cytoreductive therapy for patients with chronic Philadelphia-negative myeloproliferative neoplasms (MPNs) includes hydroxyurea (HU), interferon-alpha2 (IFN), and anagrelide. HU is worldwide the most used cytoreductive agent, which lowers elevated blood cell counts within days in the large majority of patients. However, some patients may experience rebound cytosis when HU is reduced due to cytopenia, thereby potentially giving rise to fluctuating cell counts during therapy. Such rapid oscillations may be harmful and potentially elicit thrombosis. Treatment with IFN gradually lowers elevated cell counts within weeks and when the dosage is reduced, the cell counts do not rapidly increase but are sustained within the normal range in the large majority of patients. Conventional hematological response criteria are among others based upon single absolute cell count values and do not take into account the relative decreases toward normal for each cell count.

MATERIALS, METHODS & RESULTS

Using serial data from the Danish DALIAH trial, we herein describe a novel integrated biomarker index for the assessment of hematological and molecular (JAK2V617F) responses in patients with MPNs during treatment with IFN or HU.

DISCUSSION

This novel tool convincingly displays the superiority of IFN versus HU in normalizing elevated cell counts. Our results need to be validated in larger studies but already now call for studies of the safety and efficacy of combination therapy during the initial treatment of patients with MPNs.

Caught between competing emotions and tensions - a focus group study exploring experiences of family caregivers of out-of-hospital cardiac arrest survivors

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction

Being a family member caring for an out-of-hospital cardiac arrest (OHCA) survivor may impact family caregivers’ lives due to the sudden onset of the illness and possible secondary cognitive, emotional and physical challenges. However, experiences of caring for an OHCA survivor are sparsely described.

Purpose

This purpose of this study was to explore the subjective experiences of family caregivers of OHCA survivors as a means of understanding the potential burden they face.

Methods

Using an explorative qualitative approach, six focus group interviews were conducted with a sample of 25 family caregivers of OHCA survivors and analysed using a phenomenological hermeneutic approach inspired by the philosophy of Ricoeur. OHCA survivors and their family caregivers were attenting at a residential rehabilitation course, where the caregivers were interviewed as part of the course.

Results

Three themes emerged: i) Feeling unexpectedly alone and invisible; the family caregivers felt an emotional burden that could not be shared – leading to caregiving being a lonely and anxious experience. The family caregiver felt alone with the responsibility of the shared life, ii) Fear of loss; the fear of losing a loved one was a constant companion contributing to the burden of caregiving, and iii) Adjusting to a new everyday life; the family caregivers had difficulties adjusting to living their lives on the basis of the survivors’ needs. This often resulted in an existential crisis trying to adapt (Figure 1).

Conclusion

The findings of this study illuminate and emphasise the burden experienced by family caregivers and how they can be caught between competing emotions and tensions. The possible caregiver burden following OHCA should be acknowledged.

Systematic screening is needed to identify those at risk of high caregiver burden. Further, collaboration with family care givers should be an essential part of post-cardiac arrest care, and interventions to reduce the burden should be tested and implemented as part of the clinical care of OHCA survivors and their families.

The use of advanced platelet-rich fibrin after surgical removal of mandibular third molars: a systematic review and meta-analysis

The objective of this systematic review was to test the hypothesis of no difference in recovery following surgical removal of mandibular third molars with the application of advanced platelet-rich fibrin (A-PRF) in the extraction socket compared with alternative biomaterials or natural wound healing. A search of MEDLINE (PubMed), Embase, Cochrane Library, and Scopus was conducted. Human randomized controlled trials published in English up until December 31, 2020 were included. Outcome measures were pain, facial swelling, trismus, soft tissue healing, alveolar osteitis, and quality of life; these were evaluated by descriptive statistics and meta-analysis including 95% confidence intervals (CI). Four studies with a low or moderate risk of bias fulfilled the inclusion criteria. A-PRF resulted in significantly lower pain scores when compared with leucocyte platelet-rich fibrin or natural wound healing after 2 days (-16.8, 95% CI -18.9 to -14.7), 3 days (-12.1, 95% CI -13.4 to -10.7), and 7 days (-1.9, 95% CI -2.9 to -0.9). A-PRF seems to have a negligible effect on facial swelling and trismus and some beneficial effect on soft tissue healing. Alveolar osteitis and quality of life were not assessed. The included studies were characterized by considerable heterogeneity and confounding variables. Thus, the level of evidence appears to be inadequate for clinical recommendations according to the focused question.

[Elevated blood cell counts and vascular disease with the myeloproliferative neoplasms as model diseases]

Recent studies have shown the Philadelphia-negative myeloproliferative neoplasms (MPN) to be massively underdiagnosed and often preceded by a long pre-diagnostic phase of several years, in which many patients suffer serious vascular events. In this review, we focus on the urgent need for earlier diagnosis and treatment of MPN. Such efforts are foreseen to decrease morbidity and mortality for the individual patients and potentially reduce costs for health and social care systems.

The role of home visits by a nurse to improve palliation in patients treated with self-expandable metallic stents due to incurable esophageal cancer

Self-expandable metallic stent (SEMS) is a preferred option to relieve dysphagia and to palliate patients with incurable esophageal or gastro-esophageal junction (GEJ) cancer. Health Related Quality of Life (QoL) represents a clinically relevant outcome measure in research focused on palliation of patients with advanced GI cancer. In this context, home visits by a nurse carry the potential to offer important advantages. Eighty patients with incurable esophageal or GEJ cancer were randomized to either standard follow up or to an intervention containing regular home visits by a nurse. The primary outcome variable QoL was assessed by EORTC QLQ-C30 and OES-18 before insertion of SEMS, and at 2, 7 and 12 weeks thereafter. Secondary outcomes were; need for re-interventions, number of patients receiving palliative oncological therapy and overall survival. Sixty-six males and 13 females, with a median age of 71, were included. Self-reported overall QoL was significantly higher in the intervention group (P = 0.03). The organ specific module OES-18 revealed a significant reduction in dysphagia by the intervention (P = 0.03) as well as fewer eating disabilities (P = 0.04). No differences were observed in secondary outcomes except for overall survival, where the median survival was increased from 114 to 183 days by the active intervention (P = 0.02). Home visits by a nurse seem to play an important palliative role after placement of SEMS in patients with incurable esophageal or GEJ cancer by improving QoL and may carry the potential to increase overall survival.

Lactase persistence, milk intake, hip fracture and bone mineral density: a study of 97 811 Danish individuals and a meta-analysis

BACKGROUND

Whether a causal relationship exists between milk intake and reduced risk of fractures is unclear.

OBJECTIVES

We tested the hypothesis that genetically determined milk intake reduces the risk of fractures and increases bone mineral density (BMD).

METHODS

We investigated the association between milk intake, LCT-13910 C/T (rs4988235), which is associated with lactase persistence (TT/TC) in Northern Europeans, and hip fractures in three Danish prospective studies (N = 97 811, age ≥20 years). We added meta-analyses of LCT-13910 and fractures and BMD from five published Northern European population studies.

RESULTS

In the Danish studies, the adjusted hazard ratio (HR) for hip fracture per one glass per week higher milk intake was 1.00 (95% CI: 0.99-1.01). The per T-allele milk intake was 0.58 (0.49-0.68) glasses per week, but HR was 1.01 (0.94-1.09) for hip fracture. In meta-analyses of Danish studies with published Northern European population studies, the random effects odds ratio for any fracture was 0.86 (0.61-1.21; I² = 73%) for TT vs. CC and 0.90 (0.68-1.21; I² = 63%) for TC vs. CC. The standardized mean difference in femoral neck BMD was 0.10 (0.02-0.18; I² = 0%) g cm^-2 for TT vs. CC and 0.06 (-0.04 to 0.17; I² = 17%) g cm^-2 for TC vs. CC. There were no differences in lumbar spine or total hip BMD comparing TT or TC with CC.

CONCLUSION

Genetically lifelong lactase persistence with high milk intake was not associated with hip fracture in Danish population-based cohorts. A meta-analysis combining Danish studies with published Northern European population studies also showed that lactase persistence was not associated with fracture risk. Genetic lactase persistence was associated with a higher femoral neck BMD, but not lumbar spine or total hip BMD.

Effect of substituting soybean meal and canola cake with dried distillers grains with solubles at 2 dietary crude protein levels on feed intake, milk production, and milk quality in dairy cows

Dried distillers grain with solubles (DDGS) is an alternative source of feed protein for dairy cows. Previous studies found that DDGS, based on grains other than corn, can substitute for soybean meal and canola cake as a dietary protein source without reducing milk production or quality. As societal concerns exist, and in many areas strict regulation, regarding nitrogen excretion from dairy cows, the dairy industry has focused on reducing dietary protein level and nitrogen excretion. In the present study, we investigated the use of DDGS as a protein source, at a marginally low dietary crude protein (CP) levels, in a grass-clover and corn silage-based ration. The experiment involved 24 Holstein cows and 2 protein sources (DDGS or soybean-canola mixture) fed at 2 levels of CP (14 or 16%) in a 4 × 4 Latin square design. The aim of this study was to evaluate the effect of both protein source and protein level on feed intake, milk yield, and milk quality. The results indicated that feed intake, milk yield, and protein in milk increased when the protein level in the ration was 16% CP compared with 14%. We found no effect of substituting the soybean-canola mixture with DDGS. Moreover, no sensory problems were observed when comparing fresh milk with stored milk, and milk taste was unaffected by DDGS. Milk from cows fed DDGS had a slightly higher content of linoleic acid and conjugated linoleic acid (CLA 9-11), and lower content of C11 to C17 fatty acids than cows fed diets with the soybean-canola mixture. Cows fed the diets with 16% CP produced milk with higher oleic acids and lower palmitic acid content than cows fed 14% CP diets. To conclude, DDGS can substitute for a soybean-canola mixture without affecting feed intake, milk yield and quality, or sensory quality. Under the conditions of this experiment, feeding 16% CP compared with 14% CP in the ration can increase feed intake and milk production.

Effect of substituting soybean meal and canola cake with grain-based dried distillers grains with solubles as a protein source on feed intake, milk production, and milk quality in dairy cows

The growth of the bioethanol industry is leading to an increase in the production of coproducts such as dried distillers grains with solubles (DDGS). Both corn-based DDGS and grain-based DDGS (gDDGS; defined as originating from grain sources such as barley, wheat, triticale, or a mix, excluding corn) appear to be relevant sources of feed and protein for dairy cows. To date, most of the studies investigating DDGS have been performed with corn-based DDGS. The objectives of this study were to determine the effects of the proportion of gDDGS in the diet on feed intake, milk production, and milk quality. The present experiment involved 48 Holstein cows in a replicated 3 × 3 Latin square design with 3 grass-based dietary treatments consisting of 4, 13.5, and 23% gDDGS on a dry matter (DM) basis (L, M, and H, respectively) as a replacement for a concentrate mix. The concentrate mix consisted of soybean meal, canola cake, and beet pulp. Dry matter intake and energy-corrected milk yield were not affected by the proportion of gDDGS in the diet. Daily milk yield decreased with the H diet compared with the L and M diets. The percentage of fat in milk was higher when cows were fed the H diet compared with the L and M diets, whereas milk fat yield was not affected by dietary treatment. The M diet had a higher percentage of protein in milk compared with the L and H diets. Milk protein yield was similar for the L and M diets; however, it decreased for the H diet. Milk taste was not affected by the proportion of gDDGS in the diet or when milk was stored for 7 d. Linoleic acid and conjugated linoleic acid cis-9,trans-11 in milk increased with increasing proportion of gDDGS. To conclude, gDDGS can replace soybean meal and canola cake as a protein source in the diet of dairy cows. Up to 13.5% of the diet may consist of gDDGS without negatively affecting milk production, milk quality, or milk taste. When gDDGS represents 23% of dietary DM, milk production is reduced by 1.6 kg/d, whereas energy-corrected milk production is numerically reduced by 1 kg.

Effect of dietary nitrate level on enteric methane production, hydrogen emission, rumen fermentation, and nutrient digestibility in dairy cows

Nitrate may lower methane production in ruminants by competing with methanogenesis for available hydrogen in the rumen. This study evaluated the effect of 4 levels of dietary nitrate addition on enteric methane production, hydrogen emission, feed intake, rumen fermentation, nutrient digestibility, microbial protein synthesis, and blood methemoglobin. In a 4×4 Latin square design 4 lactating Danish Holstein dairy cows fitted with rumen, duodenal, and ileal cannulas were assigned to 4 calcium ammonium nitrate addition levels: control, low, medium, and high [0, 5.3, 13.6, and 21.1g of nitrate/kg of dry matter (DM), respectively]. Diets were made isonitrogenous by replacing urea. Cows were fed ad libitum and, after a 6-d period of gradual introduction of nitrate, adapted to the corn-silage-based total mixed ration (forage:concentrate ratio 50:50 on DM basis) for 16d before sampling. Digesta content from duodenum, ileum, and feces, and rumen liquid were collected, after which methane production and hydrogen emissions were measured in respiration chambers. Methane production [L/kg of dry matter intake (DMI)] linearly decreased with increasing nitrate concentrations compared with the control, corresponding to a reduction of 6, 13, and 23% for the low, medium, and high diets, respectively. Methane production was lowered with apparent efficiencies (measured methane reduction relative to potential methane reduction) of 82.3, 71.9, and 79.4% for the low, medium, and high diets, respectively. Addition of nitrate increased hydrogen emissions (L/kg of DMI) quadratically by a factor of 2.5, 3.4, and 3.0 (as L/kg of DMI) for the low, medium, and high diets, respectively, compared with the control. Blood methemoglobin levels and nitrate concentrations in milk and urine increased with increasing nitrate intake, but did not constitute a threat for animal health and human food safety. Microbial crude protein synthesis and efficiency were unaffected. Total volatile fatty acid concentration and molar proportions of acetate, butyrate, and propionate were unaffected, whereas molar proportions of formate increased. Milk yield, milk composition, DMI and digestibility of DM, organic matter, crude protein, and neutral detergent fiber in rumen, small intestine, hindgut, and total tract were unaffected by addition of nitrate. In conclusion, nitrate lowered methane production linearly with minor effects on rumen fermentation and no effects on nutrient digestibility.

Novel aspects of health promoting compounds in meat

Meat is an integral part of the human diet. Besides essential amino acids and nutritive factors of high quality and availability, meat provides often overlooked components of importance for human health. These are amino acids and bioactive compounds that may be very important in i) preventing muscle wasting diseases, such as in sarcopenia, ii) reducing food and caloric intake to prevent metabolic syndrome, iii) blood pressure homeostasis via ACE-inhibitory components from connective tissue, and iv) maintaining functional gut environment through meat-derived nucleotides and nucleosides. In addition, meat could be an important source of phytanic acid, conjugated linoleic acids and antioxidants. Further, it becomes increasingly apparent that design of in vitro meat will be possible, and that this development may lead to improved health benefits from commercially viable and sustainable meat products.

Methane production and digestion of different physical forms of rapeseed as fat supplements in dairy cows

The purpose of this experiment was to study the effect of the physical form of rapeseed fat on methane (CH4) mitigation properties, feed digestion, and rumen fermentation. Four lactating ruminal-, duodenal-, and ileal-cannulated Danish Holstein dairy cows (143 d in milk, milk yield of 34.3 kg) were submitted to a 4×4 Latin square design with 4 rations: 1 control with rapeseed meal (low-fat, CON) and 3 fat-supplemented rations with either rapeseed cake (RSC), whole cracked rapeseed (WCR), or rapeseed oil (RSO). Dietary fat concentrations were 3.5 in CON, 5.5 in RSC, 6.2 in WCR, and 6.5% in RSO. The amount of fat-free rapeseed was kept constant for all rations. The forage consisted of corn silage and grass silage and the forage to concentrate ratio was 50:50 on a dry matter basis. Diurnal samples of duodenal and ileal digesta and feces were compiled. The methane production was measured for 4 d in open-circuit respiration chambers. Additional fat reduced the CH4 production per kilogram of dry matter intake and as a proportion of the gross energy intake by 11 and 14%, respectively. Neither the total tract nor the rumen digestibility of organic matter (OM) or neutral detergent fiber were significantly affected by the treatment. Relating the CH4 production to the total-tract digested OM showed a tendency to decrease CH4 per kilogram of digested OM for fat-supplemented rations versus CON. The acetate to propionate ratio was not affected for RSC and WCR but was increased for RSO compared with CON. The rumen ammonia concentration was not affected by the ration. The milk and energy-corrected milk yields were unaffected by the fat supplementation. In conclusion, rapeseed is an appropriate fat source to reduce the enteric CH4 production without affecting neutral detergent fiber digestion or milk production. The physical form of fat did not influence the CH4-reducing effect of rapeseed fat. However, differences in the volatile fatty acid pattern indicate that different mechanisms may be involved.

Milk fatty acid composition and production performance of Danish Holstein and Danish Jersey cows fed different amounts of linseed and rapeseed

Fat supplements are used in diets for dairy cows to increase energy intake and milk production and the fatty acid composition of the feed affects milk fatty acid composition. A total of 74 Danish Holstein and 41 Danish Jersey cows were divided into 4 groups and the cows within each group were fed a mixed ration supplemented with 0, 3.5, 6.8, or 10.2% of dry matter of a linseed:rapeseed (1:3) mixture during lactation wk 6 to 30. Milk yield, fat, and lactose contents were not affected by treatments for Danish Holsteins, whereas these parameters increased when increased amounts of oilseeds were fed to Danish Jerseys. For both breeds, milk protein content decreased when increased amounts of oilseeds were fed. The milk fatty acid composition showed higher concentrations of saturated fatty acids and lower concentrations of unsaturated fatty acids in milk fat from Danish Jerseys compared with Danish Holsteins. Increased amounts of oilseeds in feed increased milk fat concentration of all C18 fatty acids except C18:2 n-6, whereas the content of C6 to C14, C11 to C17, and in particular, C16, decreased. This effect was more pronounced for Danish Holsteins than for Danish Jerseys. The apparent recovery of C18:2 n-6 and C18:3 n-3 decreased when increased amounts of oilseeds were fed; however, this was most likely due to increased amounts of fatty acid from feed used for other energy demands than milk production. It was concluded that up to 6.8% of oilseed supplementation can be fed without production problems and, in many cases, with positive production responses, including an improved milk fatty acid profile.

Milk quality as affected by feeding regimens in a country with climatic variation

To investigate the influence of climatic conditions and season on milk composition, bulk tank milk was sampled on 5 occasions during a period of 15 mo from 20 Swedish dairy farms. These farms included 5 organic and 5 conventional farms in central Sweden and 7 traditional conventional farms and 3 conventional farms growing maize for silage in southern Sweden. Feed data and milk yield were recorded and milk was analyzed for content of fatty acids, carotenoids, and tocopherol. Differences between milk from the 2 regions and between summer and winter seasons were shown. Milk from central Sweden differed from milk from southern Sweden in that it had a higher content of carotenoids, tocopherol, short-chain fatty acids (C4-C14), C18:0, and C18:3 n-3 and a lower content of C16. Summer milk samples had a lower fat content and contained higher amounts of C18:1 cis-9 and conjugated linoleic acid cis-9,trans-11, and lower amounts of C4 to C16 compared with winter milk. Differences between farm types from central Sweden were lower content of conjugated linoleic acid cis-9,trans-11 and higher content of C18:3 n-3 in organic milk compared with conventional milk. In southern Sweden the use of maize silage caused lower milk content of carotenoids and C18:3 n-3 when compared with traditional feeding. Differences in milk composition could be related to climatic differences because legumes are more dominating in the leys of central Sweden and maize growing is limited to southern Sweden.

Modified cytokeratins expressed on the surface of carcinoma cells undergo endocytosis upon binding of human monoclonal antibody and its recombinant Fab fragment

Previously, we have reported on successful imaging of colon, rectal, and pancreatic carcinomas in patients by using a radiolabeled all-human monoclonal antibody, COU-1, directed against modified cytokeratin. To further develop this antibody for use as an immunoconjugate, COU-1 was cloned by phage display selection and the human Fab fragment was expressed in bacteria. Analysis by confocal laser scanning microscopy demonstrated that COU-1 bound in a uniform punctate pattern to the surface of viable carcinoma cells stained at 4 degrees C, and binding increased significantly when cells were cultured on fibronectin, laminin, or collagen IV. In the case of fibronectin, COU-1 staining was particularly enhanced at intercellular junctions. When carcinoma cells were cultured with COU-1 at 37 degrees C for 6 hr, the antibody was found in large perinuclear vesicles and the punctate surface staining was significantly reduced. Similar results were obtained using intact IgM COU-1 and the recombinant Fab fragment. Immunohistological studies indicated that COU-1, in contrast to murine monoclonal antibodies against normal cytokeratin 8 and 18, could differentiate between malignant and normal colon epithelia, and between colon cancer metastasis in the liver and surrounding normal hepatocytes. Within biopsies of malignant tissue, COU-1 exhibited membrane-associated staining of proliferating cells, while resting cells had a filamentous pattern. Thus, modified cytokeratin at the surface of carcinoma cells may represent a new target for immunoconjugates and may explain the promising results of the phase I/II clinical study.

The day-to-day variation in insulin sensitivity in non-insulin-dependent diabetes mellitus patients assessed by the hyperinsulinemic-euglycemic clamp method

The objective was to study the day-to-day variation in insulin sensitivity in non-insulin-dependent diabetes mellitus (NIDDM) and to analyze within- and between-person variances in the glucose infusion rate during steady state (M value). Ten NIDDM patients attending the outpatient clinic at Aarhus Amtssygehus were studied three times under standardized conditions. Each time, a 120-minute hyperinsulinemic-euglycemic clamp was performed. Similar M values were found on the 3 study days, with difference between M values on the 3 days of (mean +/- SD) 0.3 +/- 1.8 mg glucose/kg lean body mass (LBM)/min. The total coefficient of variation (CV) for M values was 57% after the first clamp, 55% after the second, and 53% after the third. Ninety percent of the total day-to-day variation in M values could be ascribed to between-person variation and 10% to within-person variation. Within-person components of variance included all sources of variation other than between-person variation. The within-person CV for M values was 11.9% +/- 7.2% after two clamp studies and 12.1% +/- 7.3% after three (P < .55). In conclusion, under standardized conditions, a valid estimate of insulin sensitivity assessed by the hyperinsulinemic-euglycemic clamp in NIDDM patients is obtained after a single measurement. Because of large between-person variation, paired data should be used when comparing insulin sensitivity in NIDDM patients.