The Vulnerabilities of Orphaned Children Participating in Research: A Critical Review and Factors for Consideration for Participation in Biomedical and Behavioral Research

Orphans are a subpopulation with a unique set of additional vulnerabilities. Increasing focus on children’s rights, pediatric global health, and pediatric research makes it imperative to recognize and address unique vulnerabilities of orphaned children. This paper describes the unique vulnerabilities of the orphaned pediatric population and offers a structured set of factors that require consideration when including orphans in biomedical research. Pediatric orphans are particularly vulnerable due to decreased economic resources, psychosocial instability, increased risk of abuse, and delayed/decreased access to healthcare. These vulnerabilities are significant. By carefully considering each issue in a population in a culturally specific and study-specific manner, researchers can make valuable contributions to the overall health and well-being of this uniquely vulnerable population

Volumetric Flow Imaging Reveals the Importance of Vortex Ring Formation in Squid Swimming Tail-First and Arms-First

Squids use a pulsed jet and fin movements to swim both arms-first (forward) and tail-first (backward). Given the complexity of the squid multi-propulsor system, 3D velocimetry techniques are required for the comprehensive study of wake dynamics. Defocusing digital particle tracking velocimetry, a volumetric velocimetry technique, and high-speed videography were used to study arms-first and tail-first swimming of brief squid Lolliguncula brevis over a broad range of speeds [0-10 dorsal mantle lengths (DML) s-1) in a swim tunnel. Although there was considerable complexity in the wakes of these multi-propulsor swimmers, 3D vortex rings and their derivatives were prominent reoccurring features during both tail-first and arms-first swimming, with the greatest jet and fin flow complexity occurring at intermediate speeds (1.5-3.0 DML s-1). The jet generally produced the majority of thrust during rectilinear swimming, increasing in relative importance with speed, and the fins provided no thrust at speeds \u3e4.5 DML s-1. For both swimming orientations, the fins sometimes acted as stabilizers, producing negative thrust (drag), and consistently provided lift at low/intermediate speeds (\u3c2.0 DML s-1) to counteract negative buoyancy. Propulsive efficiency (η) increased with speed irrespective of swimming orientation, and eta for swimming sequences with clear isolated jet vortex rings was significantly greater (η=78.6 +/- 7.6%, mean +/- s.d.) than that for swimming sequences with clear elongated regions of concentrated jet vorticity (η=67.9 +/- 19.2%). This study reveals the complexity of 3D vortex wake flows produced by nekton with hydrodynamically distinct propulsors

Early cow's milk introduction is associated with failed personal-social milestones after 1 year of age

Both the American Academy of Pediatrics (AAP) and the Institute of Medicine (IOM) recommend delaying the introduction of cow's milk until after 1 year of age due to its low absorbable iron content. We used a novel computerized decision support system to gather data from multiple general pediatrics offices. We asked families whether their child received cow's milk before 1 year of age, had a low-iron diet, or used low-iron formula. Then, at subsequent visits, we performed a modified developmental assessment using the Denver II. We assessed the effect of early cow's milk or a low-iron diet on the later failure of achieving developmental milestones. We controlled for covariates using logistic regression. Early cow's milk introduction (odds ratio (OR) 1.30, p = 0.012), as well as a low-iron diet or low-iron formula (OR 1.42, p < 0.001), was associated with increased rates of milestone failure. Only personal-social milestones (OR 1.44, p = 0.002) showed a significantly higher rate of milestone failure. Both personal-social (OR 1.42, p < 0.001) and language (OR 1.22, p = 0.009) showed higher rates of failure in children with a low-iron diet. CONCLUSIONS: There is an association between the introduction of cow's milk before 1 year of age and the rate of delayed developmental milestones after 1 year of age. This adds strength to the recommendations from the AAP and IOM to delay cow's milk introduction until after 1 year of age

Clinical presentation of childhood leukaemia : a systematic review and meta-analysis

OBJECTIVE: Leukaemia is the most common cancer of childhood, accounting for a third of cases. In order to assist clinicians in its early detection, we systematically reviewed all existing data on its clinical presentation and estimated the frequency of signs and symptoms presenting at or prior to diagnosis. DESIGN: We searched MEDLINE and EMBASE for all studies describing presenting features of leukaemia in children (0-18 years) without date or language restriction, and, when appropriate, meta-analysed data from the included studies. RESULTS: We screened 12 303 abstracts for eligibility and included 33 studies (n=3084) in the analysis. All were cohort studies without control groups. 95 presenting signs and symptoms were identified and ranked according to frequency. Five features were present in >50% of children: hepatomegaly (64%), splenomegaly (61%), pallor (54%), fever (53%) and bruising (52%). An additional eight features were present in a third to a half of children: recurrent infections (49%), fatigue (46%), limb pain (43%), hepatosplenomegaly (42%), bruising/petechiae (42%), lymphadenopathy (41%), bleeding tendency (38%) and rash (35%). 6% of children were asymptomatic on diagnosis. CONCLUSIONS: Over 50% of children with leukaemia have palpable livers, palpable spleens, pallor, fever or bruising on diagnosis. Abdominal symptoms such as anorexia, weight loss, abdominal pain and abdominal distension are common. Musculoskeletal symptoms such as limp and joint pain also feature prominently. Children with unexplained illness require a thorough history and focused clinical examination, which should include abdominal palpation, palpation for lymphadenopathy and careful scrutiny of the skin. Occurrence of multiple symptoms and signs should alert clinicians to possible leukaemia

Endovascular or open repair strategy for ruptured abdominal aortic aneurysm: 30 day outcomes from IMPROVE randomised trial.

OBJECTIVE: To assess whether a strategy of endovascular repair (if aortic morphology is suitable, open repair if not) versus open repair reduces early mortality for patients with suspected ruptured abdominal aortic aneurysm. DESIGN: Randomised controlled trial. SETTING: 30 vascular centres (29 UK, 1 Canadian), 2009-13. PARTICIPANTS: 613 eligible patients (480 men) with a clinical diagnosis of ruptured aneurysm. INTERVENTIONS: 316 patients were randomised to the endovascular strategy (275 confirmed ruptures, 174 anatomically suitable for endovascular repair) and 297 to open repair (261 confirmed ruptures). MAIN OUTCOME MEASURES: 30 day mortality, with 24 hour and in-hospital mortality, costs, and time and place of discharge as secondary outcomes. RESULTS: 30 day mortality was 35.4% (112/316) in the endovascular strategy group and 37.4% (111/297) in the open repair group: odds ratio 0.92 (95% confidence interval 0.66 to 1.28; P=0.62); odds ratio after adjustment for age, sex, and Hardman index 0.94 (0.67 to 1.33). Women may benefit more than men (interaction test P=0.02) from the endovascular strategy: odds ratio 0.44 (0.22 to 0.91) versus 1.18 (0.80 to 1.75). 30 day mortality for patients with confirmed rupture was 36.4% (100/275) in the endovascular strategy group and 40.6% (106/261) in the open repair group (P=0.31). More patients in the endovascular strategy than in the open repair group were discharged directly to home (189/201 (94%) v 141/183 (77%); P<0.001). Average 30 day costs were similar between the randomised groups, with an incremental cost saving for the endovascular strategy versus open repair of £1186 (€1420; $1939) (95% confidence interval -£625 to £2997). CONCLUSIONS: A strategy of endovascular repair was not associated with significant reduction in either 30 day mortality or cost. Longer term cost effectiveness evaluations are needed to assess the full effects of the endovascular strategy in both men and women. TRIAL REGISTRATION: Current Controlled Trials ISRCTN48334791

Uptake and transport of novel amphiphilic polyelectrolyte-insulin nanocomplexes by caco-2 cells - towards oral insulin

“The original publication is available at www.springerlink.com”. Copyright SpringerPurpose: The influence of polymer architecture on cellular uptake and transport across Caco-2 cells of novel amphiphilic polyelectrolyte-insulin nanocomplexes was investigated. Method: Polyallylamine (PAA) (15 kDa) was grafted with palmitoyl chains (Pa) and subsequently modified with quaternary ammonium moieties (QPa). These two amphiphilic polyelectrolytes (APs) were tagged with rhodamine and their uptake by Caco-2 cells or their polyelectrolyte complexes (PECs) with fluorescein isothiocyanate-insulin (FITC-insulin) uptake were investigated using fluorescence microscopy. The integrity of the monolayer was determined by measurement of transepithelial electrical resistance (TEER). Insulin transport through Caco-2 monolayers was determined during TEER experiments. Result: Pa and insulin were co-localised in the cell membranes while QPa complexes were found within the cytoplasm. QPa complex uptake was not affected by calcium, cytochalasin D or nocodazole. Uptake was reduced by co-incubation with sodium azide, an active transport inhibitor. Both polymers opened tight junctions reversibly where the TEER values fell by up to 35 % within 30 minutes incubation with Caco-2 cells. Insulin transport through monolayers increased when QPa was used (0.27 ngmL-1 of insulin in basal compartment) compared to Pa (0.14 ngmL-1 of insulin in basal compartment) after 2 hours. Conclusion: These APs have been shown to be taken up by Caco-2 cells and reversibly open tight cell junctions. Further work is required to optimise these formulations with a view to maximising their potential to facilitate oral delivery of insulin.Peer reviewe

Effect of clinical isolate or cleavage site mutations in the SARS-CoV-2 spike protein on protein stability, cleavage, and cell–cell fusion

The trimeric severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein (S) is the sole viral protein responsible for both viral binding to a host cell and the membrane fusion event needed for cell entry. In addition to facilitating fusion needed for viral entry, S can also drive cell-cell fusion, a pathogenic effect observed in the lungs of SARS-CoV-2-infected patients. While several studies have investigated S requirements involved in viral particle entry, examination of S stability and factors involved in S cell-cell fusion remain limited. A furin cleavage site at the border between the S1 and S2 subunits (S1/S2) has been identified, along with putative cathepsin L and transmembrane serine protease 2 cleavage sites within S2. We demonstrate that S must be processed at the S1/S2 border in order to mediate cell-cell fusion and that mutations at potential cleavage sites within the S2 subunit alter S processing at the S1/S2 border, thus preventing cell-cell fusion. We also identify residues within the internal fusion peptide and the cytoplasmic tail that modulate S-mediated cell-cell fusion. In addition, we examined S stability and protein cleavage kinetics in a variety of mammalian cell lines, including a bat cell line related to the likely reservoir species for SARS-CoV-2, and provide evidence that proteolytic processing alters the stability of the S trimer. This work therefore offers insight into S stability, proteolytic processing, and factors that mediate S cell-cell fusion, all of which help give a more comprehensive understanding of this high-profile therapeutic target

Ross Gyre variability modulates oceanic heat supply toward the West Antarctic continental shelf

C.J.P., G.A.M., M.R.M., L.D.T., and S.T.G. were supported by NSF PLR-1425989 and OPP-1936222 (Southern Ocean Carbon and Climate Observations and Modeling project). C.J.P. received additional support from a NOAA Climate & Global Change Postdoctoral Fellowship. G.A.M. received additional support from UKRI Grant Ref. MR/W013835/1. G.E.M. was supported by NSF OPP-2220969. R.Q.P. was supported by the High Meadows Environmental Institute Internship Program. R.M. was supported by the General Sir John Monash Foundation. A.F.T. was supported by NSF OPP-1644172 and NASA grant 80NSSC21K0916. M.R.M. also acknowledges funding from NSF awards OCE-1924388 and OPP-2319829 and NASA awards 80NSSC22K0387 and 80NSSC20K1076.West Antarctic Ice Sheet mass loss is a major source of uncertainty in sea level projections. The primary driver of this melting is oceanic heat from Circumpolar Deep Water originating offshore in the Antarctic Circumpolar Current. Yet, in assessing melt variability, open ocean processes have received considerably less attention than those governing cross-shelf exchange. Here, we use Lagrangian particle release experiments in an ocean model to investigate the pathways by which Circumpolar Deep Water moves toward the continental shelf across the Pacific sector of the Southern Ocean. We show that Ross Gyre expansion, linked to wind and sea ice variability, increases poleward heat transport along the gyre’s eastern limb and the relative fraction of transport toward the Amundsen Sea. Ross Gyre variability, therefore, influences oceanic heat supply toward the West Antarctic continental slope. Understanding remote controls on basal melt is necessary to predict the ice sheet response to anthropogenic forcing.Publisher PDFPeer reviewe