Little time, lasting impact: Bereaved caregiver perceptions of legacy in perinatal and infant loss

BACKGROUND

Legacy interventions are standard in most children's hospital, but little is known about how bereaved parents understand and describe the concept of legacy that these interventions are designed to document. The aim of this qualitative study was to understand the legacy experiences and perceptions of parents who have experienced perinatal or early infant (less than three months of age) loss.

METHODS

Grounded in constructionist epistemology and phenomenological qualitative traditions, ten bereaved parents completed an in-depth phenomenological interview regarding their perceptions of and experiences with the legacy of their deceased child. Interviews were transcribed verbatim and analyzed using an open, inductive coding process to illuminate the essence of participants' experiences.

RESULTS

Three themes were identified: 1) legacies are composed of memories and experiences that have a lasting effect on others; 2) healthcare experiences both generate and participate in infants' legacies; and 3) parents' legacy perceptions are shaped by cultural conceptions, spiritual beliefs, and grief experiences. Parents described experiences and interactions with community members and healthcare providers that honored or challenged their perceptions of their child's unique legacy.

CONCLUSIONS

In the context of perinatal or early infant loss, bereaved parents describe legacy as enduring, unique to each child and family, and heavily influenced by healthcare experiences and staff relationships. Parent-led, legacy-oriented interventions are needed in maternal/fetal, labor/delivery, and neonatal intensive care settings to support parent coping with loss.

The Impact of Inflammatory Bowel Disease in Canada 2018: IBD Research Landscape in Canada

Background

Health research in Canada is funded by government, health charities, foundations and industry. We investigated levels of IBD research funding and the scientific impact of this research in Canada between 2013 and 2017.

Methods

An analysis of global and Canadian funding in IBD research was conducted using the Canadian Institutes of Health Research (CIHR) Funded Research Database and UberResearch’s Dimensions platform. Examples of priority-driven and investigator-initiated IBD research in Canada are provided. Bibliometric analysis was used to assess the quality of IBD research output in Canada.

Results

Total funding for IBD research Canada between 2013 and 2017 was over $119 million Canadian dollars (CAD), with CIHR, the largest funder, contributing almost $66 million CAD, and Crohn’s and Colitis Canada, investing more than $32 million CAD. This ranks Canada fourth internationally. A comparative analysis indicates that publications by Canadian IBD researchers have a greater impact than other Canadian and international comparators. When productivity and impact in IBD research are combined, Canada is among the top three in the world.

Conclusions

Investment in IBD research in Canada has resulted in the development of a strong collaborative group of researchers producing impactful, world-class research. On all measures of academic productivity and influence, Canada ranks in the top two or three internationally. The challenges ahead are to continue to fund innovative IBD research and grow the next generation of IBD researchers while moving research findings into changes in health policy and practice in order to benefit affected patients and their families—and ultimately, to find the cause(s) and identify the cure(s).

Simulated diabetic ketoacidosis therapy in vitro elicits brain cell swelling via sodium-hydrogen exchange and anion transport

A common complication of type 1 diabetes mellitus is diabetic ketoacidosis (DKA), a state of severe insulin deficiency. A potentially harmful consequence of DKA therapy in children is cerebral edema (DKA-CE); however, the mechanisms of therapy-induced DKA-CE are unknown. Our aims were to identify the DKA treatment factors and membrane mechanisms that might contribute specifically to brain cell swelling. To this end, DKA was induced in juvenile mice with the administration of the pancreatic toxins streptozocin and alloxan. Brain slices were prepared and exposed to DKA-like conditions in vitro. Cell volume changes were imaged in response to simulated DKA therapy. Our experiments showed that cell swelling was elicited with isolated DKA treatment components, including alkalinization, insulin/alkalinization, and rapid reductions in osmolality. Methyl-isobutyl-amiloride, a nonselective inhibitor of sodium-hydrogen exchangers (NHEs), reduced cell swelling in brain slices elicited with simulated DKA therapy (in vitro) and decreased brain water content in juvenile DKA mice administered insulin and rehydration therapy (in vivo). Specific pharmacological inhibition of the NHE1 isoform with cariporide also inhibited cell swelling, but only in the presence of the anion transport (AT) inhibitor 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid. DKA did not alter brain NHE1 isoform expression, suggesting that the cell swelling attributed to the NHE1 was activity dependent. In conclusion, our data raise the possibility that brain cell swelling can be elicited by DKA treatment factors and that it is mediated by NHEs and/or coactivation of NHE1 and AT.

Primitive neural stem cells in the adult mammalian brain give rise to GFAP-expressing neural stem cells

Adult forebrain definitive neural stem cells (NSCs) comprise a subpopulation of GFAP-expressing subependymal cells that arise from embryonic fibroblast growth factor (FGF)-dependent NSCs that are first isolated from the developing brain at E8.5. Embryonic FGF-dependent NSCs are derived from leukemia inhibitory factor (LIF)-responsive, Oct4-expressing primitive NSCs (pNSCs) that are first isolated at E5.5. We report the presence of a rare population of pNCSs in the periventricular region of the adult forebrain. Adult-derived pNSCs (AdpNSCs) are GFAP⁻, LIF-responsive stem cells that display pNSC properties, including Oct4 expression and the ability to integrate into the inner cell mass of blastocysts. AdpNSCs generate self-renewing, multipotent colonies that give rise to definitive GFAP⁺ NSCs in vitro and repopulate the subependyma after the ablation of GFAP⁺ NSCs in vivo. These data support the hypothesis that a rare population of pNSCs is present in the adult brain and is upstream of the GFAP⁺ NSCs.

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Rare, multipotent, self-renewing, Oct4⁺ AdpNSCs in the adult brain

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AdpNSCs lie upstream of definitive, GFAP-expressing adult NSCs

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AdpNSCs repopulate the SE after ablation of GFAP-expressing NSCs

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The AdpNSC pool is activated and expands after injury or LIF infusion in vivo

Diabetic ketoacidosis elicits systemic inflammation associated with cerebrovascular endothelial cell dysfunction

OBJECTIVE

To determine if the DKA-induced inflammation in juvenile mice provokes activation and dysfunction of CVECs.

METHODS

DKA in juvenile mice was induced with administration of STZ and ALX. Blood from DKA mice was assessed for cytokines and soluble cell adhesion proteins, and either DKA plasma or exogenous compounds were applied to immortalized bEND3.

RESULTS

DKA increased circulating levels of IL-6, IL-8(KC), MCP-1, IL-10, sE-selectin, sICAM-1, and sVCAM-1. Stimulation of bEND3 with DKA plasma caused cellular activation (increased ROS and activation of NF-κΒ), upregulation of a proadhesive phenotype (E-selectin, ICAM-1, and VCAM-1), and increased leukocyte-bEND3 interaction (leukocyte rolling/adhesion). TEER, a measure of bEND3 monolayer integrity, was decreased by DKA plasma. Activation and dysfunction of bEND3 with DKA plasma were suppressed by plasma heat treatment (56°C, 1 hour) and replicated with the application of DKA recombinant cytomix (IL-6, IL-8[KC], MCP-1, and IL-10), implicating circulating inflammatory protein(s) as mediators. Treatment of bEND3 with β-OH-butyrate, the main ketone elevated in DKA, failed to mimic the DKA plasma-induced activation and dysfunction of bEND3.

CONCLUSIONS

DKA elicits systemic inflammation associated with CVEC activation and dysfunction, possibly contributing to DKA-associated intracranial microvascular complications.

Combined insulin and bicarbonate therapy elicits cerebral edema in a juvenile mouse model of diabetic ketoacidosis

Cerebral edema in diabetic ketoacidosis (DKA-CE) occurs primarily in children and can develop during DKA therapy. The treatment factors contributing to DKA-CE remain elusive. Our objectives were to characterize an age-appropriate DKA mouse model and to determine which DKA therapies contribute to DKA-CE. Juvenile mice were briefly fed a high-fat diet and injected with two pancreatic beta-cell toxins: streptozocin and alloxan. Severe insulin and leptin deficiencies associated with hyperosmolar ketoacidosis rapidly developed, indicating DKA. DKA mice were treated with re-hydration +/- insulin and brain water content (BWC) measured as an indicator of DKA-CE. As expected, glucose and beta-OH-butyrate corrected in DKA mice that received rehydration and insulin. BWC significantly increased above control levels only in DKA mice that received combined insulin and bicarbonate therapy, indicating the development of DKA-CE. Microscopically, DKA-CE brains had perineuronal and perivascular edema, with microvacuolation in the white matter tracts. These results indicate that insulin-deficient juvenile mice develop biochemical changes that are similar to those of DKA in children. Increased BWC was observed only in DKA mice that received combined insulin and bicarbonate therapy, suggesting that rapid systemic alkalinization in the presence of insulin may contribute to DKA-CE.

Identification of chromosome intervals from 129 and C57BL/6 mouse strains linked to the development of systemic lupus erythematosus

Systemic lupus erythematosus is an autoimmune disease in which complex interactions between genes and environmental factors determine the disease phenotype. We have shown that genes from the non-autoimmune strains 129 and C57BL/6 (B6), commonly used for generating gene-targeted animals, can induce a lupus-like disease. Here, we conducted a genome-wide scan analysis of a cohort of (129 x B6)F2 C1q-deficient mice to identify loci outside the C1qa locus contributing to the autoimmune phenotype described in these mice. The results were then confirmed in a larger dataset obtained by combining the data from the C1q-deficient mice with data from previously reported wild-type mice. Both analyses showed that a 129-derived interval on distal chromosome 1 is strongly linked to autoantibody production. The B6 genome contributed to anti-nuclear autoantibody production with an interval on chromosome 3. Two regions were linked to glomerulonephritis: a 129 interval on proximal chromosome 7 and a B6 interval on chromosome 13. These findings demonstrate that interacting loci between 129 and B6 mice can cause the expression of an autoimmune phenotype in gene-targeted animals in the absence of any disrupted gene. They also indicate that some susceptibility genes can be inherited from the genome of non-autoimmune parental strains.

Prevention of C5 activation ameliorates spontaneous and experimental glomerulonephritis in factor H-deficient mice

Membranoproliferative glomerulonephritis (MPGN) type II (dense deposit disease) is an inflammatory renal disease characterized by electron-dense deposits and complement C3 on the glomerular basement membrane. There is no effective therapy. We investigated the role of C5 activation in a model of MPGN that develops spontaneously in complement factor H-deficient mice (Cfh(-/-)). At 12 months there was a significant reduction in mortality, glomerular cellularity, neutrophil numbers, and serum creatinine levels in Cfh(-/-) mice deficient in C5. Excessive glomerular neutrophil numbers, frequently seen in patients with MPGN during disease flares, were also observed in Cfh(-/-) mice after the administration of an antiglomerular basement membrane antibody. This exaggerated injurious phenotype was absent in Cfh(-/-) mice deficient in C5 but not in Cfh(-/-) mice deficient in C6, indicating a key role for C5 activation in the induction of renal lesions. Importantly, the renal injury was completely reversed in Cfh(-/-) mice pretreated with an anti-murine C5 antibody. These results demonstrate an important role for C5 in both spontaneous MPGN and experimentally induced nephritis in factor H-deficient mice and provide preliminary evidence that C5 inhibition therapy might be useful in human MPGN type II.

Water source utilization by Pinus jeffreyi and Arctostaphylos patula on thin soils over bedrock

Stable isotopes were used to evaluate water sources for co-occurring Jeffrey pine (Pinus jeffreyi Grev & Balf.) and greenleaf manzanita (Arctostaphylos patula Greene) in the southern Sierra Nevada, California, where soils averaged only 75 cm thick but were underlain by up to 5 m of weathered granitic bedrock. Soils and underlying weathered bedrock were sampled three times during both the 1997 and 1998 growing seasons, in 25 cm increments, from 0 to 400 cm or until hard bedrock was reached, and plant stem tissue was sampled simultaneously. Extracted water from the soil/bedrock substrate and plant tissue was analyzed for delta(18)O and/or deltaD, and depth of water source was determined by inference in conjunction with moisture status of the substrate. Water source utilization over the growing seasons for both plants generally followed a pattern similar to that observed for water depletion. Predominant water use was initially from the surface soils. Progressively deeper water sources, including weathered bedrock to a depth of several meters, were exploited as the season progressed and the overlying substrate was depleted of moisture. Early in the growing season, stable isotope values were slightly lower for pine than for manzanita (e.g., average deltaD in June 1997 was -81 per thousand for pine and -77 per thousand for manzanita), and suggest that the functional rooting depth for pine may have been slightly greater than for manzanita. In September 1997, manzanita deltaD values averaged -57 per thousand while pine values averaged -85 per thousand, indicating that manzanita opportunistically utilized summer precipitation while pine used more dependable bedrock water. In 1998, soils remained moist through July due to a late snowfall. Unlike the previous year, pine and manzanita deltaD values were not significantly different in mid- and late-growing season, and both plants exploited bedrock-derived water as soil water was depleted. Water held within bedrock was essential for meeting plant transpirational requirements over the summer drought.

Ultrastructural features of the adult hermaphrodite gonad of Caenorhabditis elegans: relations between the germ line and soma

Genetic and embryological experiments have established the Caenorhabditis elegans adult hermaphrodite gonad as a paradigm for studying the control of germline development and the role of soma-germline interactions. We describe ultrastructural features relating to essential germline events and the soma-germline interactions upon which they depend, as revealed by electron and fluorescence microscopy. Gap junctions were observed between oocytes and proximal gonadal sheath cells that contract to ovulate the oocyte. These gap junctions must be evanescent since individual oocytes lose contact with sheath cells when they are ovulated. In addition, proximal sheath cells are coupled to each other by gap junctions. Within proximal sheath cells, actin/myosin bundles are anchored to the plasma membrane at plaque-like structures we have termed hemi-adherens junctions, which in turn are closely associated with the gonadal basal lamina. Gap junctions and hemi-adherens junctions are likely to function in the coordinated series of contractions required to ovulate the mature oocyte. Proximal sheath cells are fenestrated with multiple small pores forming conduits from the gonadal basal lamina to the surface of the oocyte, passing through the sheath cell. In most instances where pores occur, extracellular yolk particles penetrate the gonadal basal lamina to directly touch the underlying oocytes. Membrane-bounded yolk granules were generally not found in the sheath cytoplasm by either electron microscopy or fluorescence microscopy. Electron microscopic immunocytochemistry was used to confirm and characterize the appearance of yolk protein in cytoplasmic organelles within the oocyte and in free particles in the pseudocoelom. The primary route of yolk transport apparently proceeds from the intestine into the pseudocoelom, then through sheath pores to the surface of the oocyte, where endocytosis occurs. Scanning electron microscopy was used to directly visualize the distal tip cell which extends tentacle-like processes that directly contact distal germ cells. These distal tip cell processes are likely to play a critical role in promoting germline mitosis. Scanning electron microscopy also revealed thin filopodia extending from the distal sheath cells. Distal sheath filopodia were also visualized using a green fluorescent protein reporter gene fusion and confocal microscopy. Distal sheath filopodia may function to stretch the sheath over the distal arm.

The POU gene ceh-18 promotes gonadal sheath cell differentiation and function required for meiotic maturation and ovulation in Caenorhabditis elegans

In Caenorhabditis elegans, specialized contractile myoepithelial cells of the somatic gonad, the gonadal sheath cells, are closely apposed to oocytes and are required for normal meiotic maturation and ovulation. Previously we found that mutations in the ceh-18 gene, which encodes a POU-class homeoprotein expressed in sheath cells, result in oocyte defects. To determine the basis for these oocyte defects, we have used time-lapse video Nomarski microscopy to observe meiotic maturation, ovulation, and early embryogenesis in ceh-18 mutants. In ceh-18 mutants sheath cell contractions are weaker, less frequent, and uncoordinated throughout the sequence of ovulation events, and ovulation is defective. Defective ovulation can result in the formation of endomitotic oocytes in the gonad, the formation of haploid embryos, and reversals in embryonic polarity. ceh-18 mutant oocytes exhibit defects prior to nuclear envelope breakdown, suggesting that they are physiologically different from the wild type. We observed delays in meiotic maturation, as well as maturation out of the normal spatial and temporal sequence, suggesting that proximal sheath cells directly or indirectly promote and spatially restrict meiotic maturation. Analysis of sheath cell differentiation in ceh-18 mutants using antibodies to proteins of the contractile apparatus reveals that although contractile proteins are expressed, the sheath cells appear disorganized. Transmission electron microscopy reveals that ceh-18 mutant sheath cells are morphologically irregular and only loosely cover oocytes. Taken together, these observations indicate that ceh-18 is a crucial determinant of sheath cell differentiation, a function required for normal meiotic maturation and ovulation.

Effects of purified Clostridium difficile toxin A on rabbit distal colon

BACKGROUND & AIMS

Antibiotic-associated pseudomembranous colitis in humans is caused by proliferation of Clostridium difficile, which elaborates an enterotoxin toxin A that causes epithelial damage and altered motility in rabbit small intestine. The aim of this study was to assess the effects of toxin A on rabbit distal colonic motility and to relate this to histological damage and inflammatory mediator production.

METHODS

Two hundred micrograms per milliliter of toxin A was placed in a distal colonic loop in anesthetized rabbits, and myoelectric activity was recorded for the following 7 hours. The colon was histologically evaluated and assayed for eicosanoid production. The effects of toxin A on longitudinal and circular muscle were also assessed in vitro.

RESULTS

Beginning 1 hour after instillation, toxin A caused a significant increase in the number of spike bursts without altering slow wave frequency; this was associated with an increase in mucosal neutrophils and increased production of prostaglandin E2 and leukotrienes B4 and C4/D4/E4. Seven hours after administration of toxin A, mediator levels and myoelectric activity remained increased but significant mucosal damage was now also present. Toxin A did not affect longitudinal or circular muscle in vitro.

CONCLUSIONS

C. difficile toxin A caused a significant neutrophil infiltration and an increased myoelectric activity before producing mucosal damage. The myoelectric effect may be indirect, resulting from the production of motility-altering arachidonic acid metabolites.