Using live feed in fish larviculture is more expensive and challenging than formulated feeds, incentivizing the early weaning of larvae. In New Zealand, the aquaculture of larval giant kōkopu, ...Galaxias argenteus, is being commercialized because of its high value and to supplement the wild fishery. As an emerging aquaculture species, inefficiencies remain in the production process, inhibiting financial viability. This study reports on the ability of these larvae to consume formulated larval diets across four ages (18, 21, 25, and 28 days after hatching, DAH) at each of the three daily feeding events (Morning, Midday, and Afternoon) during commercial production. At 18 DAH, little to no formulated feed was consumed at either of the three feeding events throughout the day. At 21 DAH, mean gut fullness increased and the number of fish with empty stomachs reduced by the end of the Morning and Afternoon feeding events. Both variables improved further for larvae at 25 and 28 DAH. Formulated feed consumption did not differ between larvae aged 25 and 28 DAH indicating that 3 days of feeding live feed could be removed from the feed regime. This change would save 13% on the cost of live feed; however, further research is required to determine the potential impacts on growth and survival.
Major losses of early juvenile seed mussels or spat are a typical feature of the aquaculture production cycle for many mussel species. These losses are caused by a variety of factors including ...predation, mortality, and the innate migratory behaviour of spat. In this study, we examined the potential to reduce spat losses by using a floating upwelling system (FLUPSY) for raising the spat of New Zealand's Greenshell™ mussel (Perna canaliculus) to a larger size before transfer to a coastal mussel farm. The losses of spat experimentally cultured within a FLUPSY over 85 days were much lower compared to spat that were seeded directly into coastal waters (78% vs. 99.8%). At the end of the 85‐day nursery culture period, spat in the FLUPSY were 7% larger despite being cultured at higher densities. The losses for two size classes of spat that were raised in the FLUPSY remained relatively high (83% and 95% for spat seeded out at 6.6‐ and 15.5‐mm shell length (SL) respectively) after two months of being experimentally seeded onto a coastal mussel farm. However, these losses are lower than have been reported previously for this species during this stage of production. The results from this study suggest that the addition of a FLUPSY nursery stage to the Greenshell™ mussel production could greatly reduce spat losses and improve production efficiency.
The seeding of small juvenile green‐lipped mussels (Perna canaliculus) onto coastal farms is associated with high losses. These losses can be reduced by seeding larger juveniles; however, the nursery ...culture of juveniles is unviable because of the high cost of producing live microalgal feeds. In this study, we compared the ability for two diets, a formulated microparticulate feed, MySpat and liposomes fabricated with mussel extract to replace live microalgae at different proportions for feeding small (1.9 mm shell length ±0.02 SE) green‐lipped mussels. The experimental diets consisted of a mix of live Tisochrysis lutea, Diacronema lutheri and Chaetoceros muelleri that were replaced with increasing proportions of MySpat (25%, 50% and 75%), and liposomes (25% and 50%). There were no significant differences in mortality of mussels relative to the control (100% microalgae) among any of the diet treatments. However, mussel growth tended to decrease with increasing substitution of the microalgal component of the diets. The results from this study suggest that microparticulate and liposome formats provide a viable mode of food delivery to juvenile mussels, with improved formulation of these formats having the potential to lead to the substitution of live microalgal diets which make nursery culture unviable at present.
The nutritional condition of juvenile mussels appears to play a major role in their performance after they are seeded into coastal mussel farms. However, the extent to which the nutritional condition ...of juvenile mussels varies with size and starvation are poorly understood. Therefore, this study measured the biochemical composition of juvenile green-lipped mussels of five sizes (range of 0.5–7.5 mm shell length), from three different sources (i.e., harvested from wild, hatchery, coastal floating upweller nursery system) and when subjected to starvation for up to two weeks. The biochemical composition of spat sampled on their arrival from all sources was dominated by protein (ranging from 24 to 70% dry tissue mass), followed by lipid (0.3–9.3%) and carbohydrate (0.3–2.8%). Subsequent starvation treatments predominantly affected carbohydrate content. Initially, spat of 1.1–1.4 mm (harvested wild spat) had the lowest initial carbohydrate content 73% lower than spat of 0.5–1.0 mm (hatchery spat) and 53–65% lower than spat of 1.5–2.0, 2.1–3.4 and 3.5–7.5 mm (hatchery spat that were reared to larger sizes in a floating upweller system). Following one and two weeks of starvation, carbohydrate energy reserves of spat from all size classes showed a decrease of 15–42% from their initial level, except spat of 1.1–1.4 mm (wild) which did not decrease with starvation. Fatty acid dietary markers sampled from both spat of 0.5–1.0 mm (hatchery) and spat of 1.1–1.4 mm (wild) prior to starvation indicated that diatoms were important contributors to the diet of spat from both sources. Following two weeks of starvation, spat from both groups utilised SFA 14:0 and PUFAs, including essential fatty acids EPA, as energy sources, but they conserved AA and DHA. The findings of this study suggest that carbohydrate is the main energy reserve utilised by green-lipped mussel spat when food supplies are limited. Therefore, improving the carbohydrate reserves of spat through appropriate nursery feeding regimes has the potential to improve their resilience to poor feeding conditions following seeding onto coastal mussel farms.
•Proximate composition of juvenile mussels 0.5–7.5 mm were dominated by protein.•Juvenile mussels primarily utilize carbohydrate reserve when starved for two weeks.•Juvenile mussels sourced from wild were in poor nutritional condition.•Fatty acids from diatoms are important in both wild and hatchery juvenile mussels.•Nursery culture of juvenile mussels should target improving carbohydrate reserves.
Peripheral blood natural killer (NK) cell therapy for acute myeloid leukemia has shown promise in clinical trials after allogeneic stem cell transplantation. Cord blood (CB) is another potentially ...rich source of NK cells for adoptive immune therapy after stem cell transplantation. Tightly regulated receptor signaling between NK cells and susceptible tumor cells is essential for NK cell-mediated cytotoxicity. However, despite expressing normal surface activating and inhibitory NK receptors, CB-derived NK cells have poor cytolytic activity. In this study, we investigate the cellular mechanism and demonstrate that unmanipulated CB-NK cells exhibit an impaired ability to form F-actin immunologic synapses with target leukemia cells compared with peripheral blood-derived NK cells. In addition, there was reduced recruitment of the activating receptor CD2, integrin leukocyte function-associated antigen-1, and the cytolytic molecule perforin to the CB-NK synapse site. Exvivo interleukin (IL)-2 expansion of CB-NK cells enhanced lytic synapse formation including CD2 and leukocyte function-associated antigen-1 polarization and activity. Furthermore, the acquired antileukemic function of IL-2-expanded CB-NK cells was validated using a nonobese diabetic severe combined immunodeficient IL-2 receptor common γ-chain null mouse model. We believe our results provide important mechanistic insights for the potential use of IL-2-expanded CB-derived NK cells for adoptive immune therapy in leukemia.
The characterization of many cytokines involved in the control of hematopoiesis has led to intense investigation into their potential use in ex vivo culture to expand progenitor numbers. We have ...established the optimum ex vivo culture conditions that allow substantial amplification of transient engrafting murine stem cells and which, simultaneously, augment the ability to sustain serial bone marrow transplantation (BMT). Short-term incubation of unfractionated BM cells in liquid culture with stem cell factor (SCF) and interleukin-11 (IL-11) produced a 50-fold amplification of clonogenic muhtipotential progenitors (CFU-A). Following such ex vivo expansion, substantially fewer cells were required to rescue lethally irradiated mice. When transplanted in cell doses above threshold for engraftment, BM cells expanded ex vivo resulted in significantly more rapid hematopoietic recovery. In a serial transplantation model, unmanipulated BM was only able to consistently sustain secondary BMT recipients, but BM expanded ex vivo has sustained quaternary BMT recipients that remain alive and well more than 140 days after 4° BMT. These results show augmentation of both short-term recovery posttransplant and the ability to serially transplant marrow by preincubation in culture with SCF and IL-11.
A practical, catalytic entry to α,α,α‐trisubstituted (α‐tertiary) primary amines by C−H functionalisation has long been recognised as a critical gap in the synthetic toolbox. We report a simple and ...scalable solution to this problem that does not require any in situ protection of the amino group and proceeds with 100 % atom‐economy. Our strategy, which uses an organic photocatalyst in combination with azide ion as a hydrogen atom transfer (HAT) catalyst, provides a direct synthesis of α‐tertiary amines, or their corresponding γ‐lactams. We anticipate that this methodology will inspire new retrosynthetic disconnections for substituted amine derivatives in organic synthesis, and particularly for challenging α‐tertiary primary amines.
Catalytic strategies for the α‐C−H functionalisation of primary amines are a major challenge in organic synthesis. A photocatalytic protocol for the α‐C−H alkylation of unprotected primary amines that is amenable to the direct synthesis of α‐tertiary primary amines is reported. This process is readily scalable in continuous flow to provide access to decagram quantities of valuable γ‐lactams and azaspirocycles, for application in drug discovery.
Human induced pluripotent stem cells (hiPSCs) are a powerful model of neural differentiation and maturation. We present a hiPSC transcriptomics resource on corticogenesis from 5 iPSC donor and 13 ...subclonal lines across 9 time points over 5 broad conditions: self-renewal, early neuronal differentiation, neural precursor cells (NPCs), assembled rosettes, and differentiated neuronal cells. We identify widespread changes in the expression of both individual features and global patterns of transcription. We next demonstrate that co-culturing human NPCs with rodent astrocytes results in mutually synergistic maturation, and that cell type-specific expression data can be extracted using only sequencing read alignments without cell sorting. We lastly adapt a previously generated RNA deconvolution approach to single-cell expression data to estimate the relative neuronal maturity of iPSC-derived neuronal cultures and human brain tissue. Using many public datasets, we demonstrate neuronal cultures are maturationally heterogeneous but contain subsets of neurons more mature than previously observed.
Background
Optimal chemotherapy for treating mixed‐phenotype acute leukemia (MPAL) and the role of hematopoietic stem cell transplantation (HSCT) remain uncertain. Major limitations in interpreting ...available data are MPAL's rarity and the use of definitions other than the currently widely accepted criteria: the World Health Organization 2016 (WHO2016) classification.
Methods
To assess the relative efficacy of chemotherapy types for treating pediatric MPAL, the Children's Oncology Group (COG) Acute Leukemia of Ambiguous Lineage Task Force assembled a retrospective cohort of centrally reviewed WHO2016 MPAL cases selected from banking studies for acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Patients were not treated in COG trials; treatment and outcome data were captured separately. The findings were then integrated with the available, mixed literature to develop a prospective trial in pediatric MPAL.
Results
The central review confirmed that 54 of 70 cases fulfilled WHO2016 criteria for MPAL. ALL induction regimens achieved remission in 72% of the cases (28 of 39), whereas AML regimens achieved remission in 69% (9 of 13). The 5‐year event‐free survival (EFS) and overall survival (OS) rates for the entire cohort were 72% ± 8% and 77% ± 7%, respectively. EFS and OS were 75% ± 13% and 84% ± 11%, respectively, for those receiving ALL chemotherapy alone without HSCT (n = 21).
Conclusions
The results of the COG MPAL cohort and a literature review suggest that ALL chemotherapy without HSCT may be the preferred initial therapy. A prospective trial within the COG is proposed to investigate this approach; AML chemotherapy and/or HSCT will be reserved for those with treatment failure as assessed by minimal residual disease. Embedded biology studies will provide further insight into MPAL genomics.
Acute lymphoblastic leukemia–directed chemotherapy without hematopoietic stem cell transplantation may be sufficient therapy for most children with World Health Organization 2016 classification–defined mixed‐phenotype acute leukemia. A proposed prospective trial will investigate this approach and explore mixed‐phenotype acute leukemia genomics and correlative biology.
Philadelphia chromosome-like (Ph-like) acute lymphoblastic leukemia (ALL) is a high-risk subtype characterized by genomic alterations that activate cytokine receptor and kinase signaling. We examined ...the frequency and spectrum of targetable genetic lesions in a retrospective cohort of 1389 consecutively diagnosed patients with childhood B-lineage ALL with high-risk clinical features and/or elevated minimal residual disease at the end of remission induction therapy. The Ph-like gene expression profile was identified in 341 of 1389 patients, 57 of whom were excluded from additional analyses because of the presence of BCR-ABL1 (n = 46) or ETV6-RUNX1 (n = 11). Among the remaining 284 patients (20.4%), overexpression and rearrangement of CRLF2 (IGH-CRLF2 or P2RY8-CRLF2) were identified in 124 (43.7%), with concomitant genomic alterations activating the JAK-STAT pathway (JAK1, JAK2, IL7R) identified in 63 patients (50.8% of those with CRLF2 rearrangement). Among the remaining patients, using reverse transcriptase polymerase chain reaction or transcriptome sequencing, we identified targetable ABL-class fusions (ABL1, ABL2, CSF1R, and PDGFRB) in 14.1%, EPOR rearrangements or JAK2 fusions in 8.8%, alterations activating other JAK-STAT signaling genes (IL7R, SH2B3, JAK1) in 6.3% or other kinases (FLT3, NTRK3, LYN) in 4.6%, and mutations involving the Ras pathway (KRAS, NRAS, NF1, PTPN11) in 6% of those with Ph-like ALL. We identified 8 new rearrangement partners for 4 kinase genes previously reported to be rearranged in Ph-like ALL. The current findings provide support for the precision-medicine testing and treatment approach for Ph-like ALL implemented in Children's Oncology Group ALL trials.
•Ph-like ALL is characterized by a diverse array of genetic alterations activating cytokine receptor and tyrosine kinase signaling.•Pediatric patients with Ph-like ALL can be identified in real time for effective treatment stratification.
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