Nausea and vomiting in end-of-life care: managing this debilitating symptom in the community.

Nausea and vomiting (N&V) are common, debilitating and distressing symptoms for patients with advanced cancer, precipitating admission to hospital for intravenous antiemetic and re-hydration (Glare et al, 2011). The causes of N&V in end-of-life care (EOLC) are multifaceted, with appropriate therapy guided by thorough assessment (Walsh et al, 2017; Watson et al, 2019). Cyclizine and levomepromazine can, depending on aetiology, be cited as effective antiemetic agents for patients with advanced cancer (Ingleton and Larkin, 2015; Watson et al, 2019). Conversely, careful consideration of the use of dexamethasone for the management of N&V in EOLC should be taken, due to known side effects (Ferrel and Paice, 2019). This case study will use a systematic approach to critically appraise the management of N&V, experienced by a community patient receiving EOLC from the district nurses.

A developmentally regulated heparan sulfate epitope defines a subpopulation with increased blood potential during mesodermal differentiation.

Heparan sulfate (HS) is a mandatory coreceptor for many growth factors and morphogens involved in embryonic development; its bioactivity is dictated by complex sulfation motifs embedded within the polymer chain. Using a panel of HS-specific antibodies we have identified a unique HS epitope recognized by antibody HS4C3 that is selectively expressed during differentiation of embryonic stem (ES) cells along the mesodermal lineage to the hemangioblast stage. The appearance of this high-affinity HS4C3-binding (HS4C3(high)) epitope is transient; the epitope is specifically expressed within the emerging Brachyury(+) (Bry(+)) population and marks those cells that will become fetal liver kinase 1 (Flk1)(+). Fluorescence-activated cell sorting (FACS) separation and colony forming assays revealed that HS4C3(high)/Flk1(+) cells have a dramatically increased potential to form both blast and endothelial colonies, both of which depend upon the HS-binding growth factor vascular endothelial growth factor. Critically, expression of this HS epitope is tightly regulated, disappearing from the cell surface as the resultant hematopoietic lineages mature, in a similar manner to protein markers Bry and Flk1. In vivo studies showed a remarkable correlation with in vitro findings, with expression of HS4C3-binding epitopes restricted to newly formed mesodermal tissues during gastrulation. We believe this is the first time a defined HS epitope has been implicated in a specific developmental pathway and that this provides, in addition, a novel enrichment technique for the isolation of hemangioblasts from mixed differentiated ES cell cultures.

The heparanome--the enigma of encoding and decoding heparan sulfate sulfation.

Heparan sulfate (HS) is a cell surface carbohydrate polymer modified with sulfate moieties whose highly ordered composition is central to directing specific cell signaling events. The ability of the cell to generate these information rich glycans with such specificity has opened up a new field of "heparanomics" which seeks to understand the systems involved in generating these cell type and developmental stage specific HS sulfation patterns. Unlike other instances where biological information is encrypted as linear sequences in molecules such as DNA, HS sulfation patterns are generated through a non-template driven process. Thus, deciphering the sulfation code and the dynamic nature of its generation has posed a new challenge to system biologists. The recent discovery of two sulfatases, Sulf1 and Sulf2, with the unique ability to edit sulfation patterns at the cell surface, has opened up a new dimension as to how we understand the regulation of HS sulfation patterning and pattern-dependent cell signaling events. This review will focus on the functional relationship between HS sulfation patterning and biological processes. Special attention will be given to Sulf1 and Sulf2 and how these key editing enzymes might act in concert with the HS biosynthetic enzymes to generate and regulate specific HS sulfation patterns in vivo. We will further explore the use of knock out mice as biological models for understanding the dynamic systems involved in generating HS sulfation patterns and their biological relevance. A brief overview of new technologies and innovations summarizes advances in the systems biology field for understanding non-template molecular networks and their influence on the "heparanome".

Heparan sulfate 6-O-endosulfatases: discrete in vivo activities and functional co-operativity.

HS (heparan sulfate) is essential for normal embryonic development. This requirement is due to the obligatory role for HS in the signalling pathways of many growth factors and morphogens that bind to sulfated domains in the HS polymer chain. The sulfation patterning of HS is determined by a complex interplay of Golgi-located N- and O-sulfotransferases which sulfate the heparan precursor and cell surface endosulfatases that selectively remove 6-O-sulfates from mature HS chains. In the present study we generated single or double knock-out mice for the two murine endosulfatases mSulf1 and mSulf2. Detailed structural analysis of HS from mSulf1-/- fibroblasts showed a striking increase in 6-O-sulfation, which was not seen in mSulf2-/- HS. Intriguingly, the level of 6-O-sulfation in the double mSulf1-/-/2-/- HS was significantly higher than that observed in the mSulf1-/- counterpart. These data imply that mSulf1 and mSulf2 are functionally co-operative. Unlike their avian orthologues, mammalian Sulf activities are not restricted to the highly sulfated S-domains of HS. Mitogenesis assays with FGF2 (fibroblast growth factor 2) revealed that Sulf activity decreases the activating potential of newly-synthesized HS, suggesting an important role for these enzymes in cell growth regulation in embryonic and adult tissues.

Locomotion Inhibition of Cimex lectularius L. Following Topical, Sublethal Dose Application of the Chitin Synthesis Inhibitor Lufenuron.

To date, few studies have evaluated chitin synthesis inhibitors against bed bugs, although they would provide an alternative mode of action to circumvent insecticide resistance. Acute and sublethal effects of lufenuron were evaluated against two strains of the common bed bug. Combined acute and sublethal effects were used to calculate effective doses. The dose that was effective against 50% of Harlan strain bed bugs was 0.0081% (w/v), and was much higher against Bradenton strain bed bugs (1.11% w/v). Sublethal doses were chosen to determine the effect that leg abnormalities had on pulling force. Both Harlan and Bradenton strain bed bugs had significantly lower locomotion ability (p < 0.0001) following topical application of lufenuron. The observed sublethal effects that limit locomotion could prevent bed bugs from moving within a domicile and taking a blood meal, subsequently reducing a bed bug population over time.

Laboratory Evaluation of a Novel Lethal Ovitrap for Control of Aedes aegypti.

Aedes aegypti (L.) (Diptera: Culicidae) are known to flourish in a variety of natural and residential habitats and are competent vectors of at least 22 different arboviruses, including dengue, chikungunya, and Zika. Their global distribution, anthropophilic nature, and vector competency make them species of interest for control. A novel durable dual-action lethal ovitrap (DDALO) with combined larviciding and adulticiding effects, as well as a slow-release polymer (isobutyl methacrylate), was designed to target Ae. aegypti. The use of the DDALO resulted in high adult mosquito mortality (~95-100%) in no-choice laboratory cage studies targeting gravid females and successfully prevented all deposited eggs from hatching. Aging of the traps caused some loss in activity over time, but they still caused adult mortality (~50%) and continued to prevent successful hatching of eggs for 6 mo. Oviposition preference studies resulted in ~4.5 times as many larvae developing in untreated DDALOs compared with the other containers combined. Small-cage multigenerational studies resulted in significantly lower populations of adult mosquitoes in cages containing treated DDALOs after 4 wk. Successful laboratory studies show that the DDALO appears to be a promising tool that could be used for controlling wild vector populations of Ae. aegypti in combination with other mosquito control practices.

Oligodendrogliomas result from the expression of an activated mutant epidermal growth factor receptor in a RAS transgenic mouse astrocytoma model.

A significant proportion of human malignant gliomas exhibit amplification, overexpression, or mutations of the epidermal growth factor receptor (EGFR). To define the functional role(s) of the EGFR in the pathogenesis of gliomas, we established transgenic mice that express both wild-type (wt) and mutant (EGFRvIII) EGFR molecules using the human glial fibrillary acidic protein (GFAP) promoter. Both GFAP-EGFR(wt) and GFAP-EGFRvIII transgenic mice demonstrated increased numbers of astrocytes compared with control littermates, however, developed normally without formation of gliomas. To determine whether EGFR overexpression could modify the tumor phenotype in our previously reported GFAP-V(12)Ha-ras transgenic mouse astrocytoma model, mice expressing both activated RAS and EGFR were developed. GFAP-V(12)Ha-ras;GFAP-EGFRvIII, but not GFAP-V(12)Ha-ras;GFAP-EGFR(wt) double transgenic mice, had decreased survival with fifty percent of the mice dead at 2-4 weeks from gliomas, compared with 12-16 weeks for the GFAP-V(12)Ha-ras mice. Furthermore, GFAP-V(12)Ha-ras;GFAP-EGFRvIII mice developed oligodendrogliomas and mixed oligoastrocytoma tumors, instead of the fibrillary astrocytomas observed in GFAP-V(12)Ha-ras mice. In addition to yielding a spontaneous model of infiltrating oligodendroglioma, this study demonstrates that astrocyte-specific expression of EGFRvIII alone is insufficient for gliomagenesis but rather contributes to glioma progression in the context of existing predisposing genetic changes.

Behavioral Responses of Nymph and Adult Cimex lectularius (Hemiptera: Cimicidae) to Colored Harborages.

Behavioral bioassays were conducted to determine whether bed bug adults and nymphs prefer specific colored harborages. Two-choice and seven-choice behavioral color assays indicate that red (28.5%) and black (23.4%) harborages are optimal harborage choices for bed bugs. Yellow and green harborages appear to repel bed bugs. Harborage color preferences change according to gender, nutritional status, aggregation, and life stage. Female bed bugs prefer harborages with shorter wavelengths (lilac-14.5% and violet-11.5%) compared to males, whereas males prefer harborages with longer wavelengths (red-37.5% and black-32%) compared with females. The preference for orange and violet harborages is stronger when bed bugs are fed as opposed to when they are starved. Lone bed bugs (30%) prefer to be in black harborages while red harborages appear to be the optimum harborage color for bed bugs in more natural mixed aggregations (35.5%). Bed bug nymphs preferred different colored harborages at each stage of development, which is indicative of their developing eye structures and pigments. First instars showed no significant preference for any colored harborage soon after hatching. However, by the fifth instar, 27.5% of nymphs significantly preferred red and black harborages (which was a similar preference to adult bed bugs). The proportion of oviposited eggs was significantly greater under blue, red, and black harborages compared to other colored harborages tested. The use of visual cues such as specific colors offers great potential for improving bed bug monitoring tools by increasing trap captures.

Astrocyte-specific expression of CDK4 is not sufficient for tumor formation, but cooperates with p53 heterozygosity to provide a growth advantage for astrocytes in vivo.

The development of malignant gliomas (astrocytomas) involves the accumulation of multiple genetic changes, including mutations in the p53 and retinoblastoma (Rb) cell cycle regulatory pathways. One Rb pathway alteration seen in high-grade astrocytomas is amplification of cyclin dependent kinase-4 (CDK4). To define the function of CDK4 amplification/overexpression in astrocytoma pathogenesis, we generated three transgenic mouse lines that overexpress human CDK4 (hCDK4) in astrocytes using the human glial fibrillary acidic protein (GFAP) promoter. GFAP-hCDK4 mice do not develop brain tumors, but exhibit a small increase in astrocyte number. Cultured astrocytes from these mice do not demonstrate a cell-autonomous growth advantage in vitro and lack properties of transformed cells. To determine whether cdk4 overexpression provides a cooperative growth advantage in vitro, CDK4-overexpressing C6 glioma cell lines were generated and found to exhibit increased cell growth. In addition, GFAP-hCDK4; p53+/- as well as p53+/-; Rb+/- mice exhibited increased numbers of astrocytes compared to GFAP-hCDK4, p53+/-, or Rb+/- mice in vivo. No cooperative effect was observed with GFAP-hCDK4; Rb+/- mice. These results support the hypothesis that cdk4 overexpression alone is not sufficient for astrocytoma formation, but can provide a cooperative growth advantage in concert with genetic alterations in the p53 pathway.

Heterozygosity for the tuberous sclerosis complex (TSC) gene products results in increased astrocyte numbers and decreased p27-Kip1 expression in TSC2+/- cells.

Tuberous sclerosis complex (TSC) is an autosomal dominant tumor predisposition syndrome characterized by benign proliferations (hamartomas). In the brain, individuals with TSC develop autism, mental retardation and seizures associated with focal cortical dysplasias, subependymal nodules, and subependymal giant cell astrocytomas (SEGAs). We hypothesize that dysregulated astrocyte function due to mutations in the tumor suppressor genes, TSC1 and TSC2, may contribute to the pathogenesis of these brain abnormalities. In this report, we demonstrate that mice heterozygous for a targeted defect in either the Tsc1 or Tsc2 genes(Tsc1+/- and Tsc2+/- mice) exhibit a 1.5-fold increase in the number of astrocytes in vivo. Whereas increased astrocyte numbers in vivo were suggestive of a proliferative advantage, Tsc2+/- primary astrocyte cultures did not show a cell-autonomous growth advantage, anchorage-independent growth, increased saturation density, or increased fluid-phase endocytosis compared to wild type astrocytes. Tsc2 null mouse embryonic fibroblasts (MEFs) however, did exhibit increased saturation density compared to Tsc2 wild type controls. In both Tsc2+/- astrocytes and Tsc2 null mouse embryonic fibroblasts, p27-Kip1 expression was decreased compared to wild type cells, and was reversed by tuberin re-expression in Tsc2-/- MEFs. In contrast, no change in endocytosis was observed upon tuberin re-expression in Tsc2-/- MEFs. Collectively, these results suggest Tsc heterozygosity may provide a non-cell-autonomous growth advantage for astrocytes that may involve p27-Kip1 expression.

X-epilectin: a novel epidermal fucolectin regulated by BMP signalling.

This paper reports the cloning and characterisation of a new posterior epidermal marker, X-epilectin, in Xenopus laevis. This gene encodes for a fucolectin, which belongs to the lectin superfamily of carbohydrate binding proteins and specifically binds fucose residues. RT-PCR and in situ hybridisation show that the expression of this gene is switched on during gastrulation and up-regulated during neurula stages and found expressed ubiquitously throughout the epidermis. From tailbud stages, the expression is limited to the dorsal posterior region of the embryo, suggesting that X-epilectin expression is regulated along anteroposterior and dorsoventral gradients during development. In the adult, X-epilectin is mainly expressed in intestinal components, kidney, spinal cord and skin. The effects of growth factors on the regulation of X-epilectin were studied. Change of the fate of animal caps into cement gland or dorsal mesoderm induces a down-regulation of X-epilectin expression in explants treated respectively with ammonium chloride and activin A. We also show that X-epilectin expression is down-regulated by Noggin and tBR and that this effect is inhibited by BMP4 over-expression, suggesting X-epilectin expression is mediated by the BMP signalling pathway.

Evaluation of Cyantraniliprole and Other Commercial Fly Baits under Laboratory and Field Conditions.

Laboratory and field trials were performed to evaluate the attractiveness and efficacy of commercial baits (cyantraniliprole; methomyl + (Z)-9-tricosene; dinotefuran + (Z)-9-tricosene; imidacloprid granular + (Z)-9-tricosene; and imidacloprid liquid + (Z)-9-tricosene). In choice tests; flies were most attracted to cyantraniliprole bait > dinotefuran + (Z)-9 > methomyl + (Z)-9 bait > imidacloprid granular + (Z)-9 bait > imidacloprid liquid + (Z)-9 bait. Significant degradation in bait efficacy was observed after two weeks of aging excluding imidacloprid granular; which began to degrade in field conditions after one week. Cyantraniliprole; the new fly bait active ingredient in Zyrox(®); had the longest time to knockdown in the laboratory tests; but on susceptible flies; achieved 95%-100% knockdown within an hour of exposure. Zyrox(®) was resistant to weathering for a week; and was more attractive to flies in the field when compared to methomyl + (Z)-9 bait.

Circulation of parasites among fishes from lakes in the Caribou Mountains, Alberta, Canada.

Circulation of 24 macroparasite species among 12 species of fish was evaluated within samples of hosts collected from 9 lakes on an isolated plateau in northern Alberta, Canada. Twenty-seven parasite taxa (24 species plus the larval stages of Triaenophorus crassus, T. stizostedionis, and Raphidascaris acus) had the potential to be circulated among hosts. Sixteen parasite taxa were recovered from a single host species within a lake. Of the 11 remaining nonspecialist taxa, 4 were larval stages that matured in fish or birds and 7 were adults. Eight of the 11 cases of circulation among hosts involved lake whitefish, and this host was involved in the transmission of 5 species to piscivorous fishes. Despite evidence for the circulation of 7 taxa among the 4 species of sympatric Salmonidae, 60-99% of all worms were recovered from just 1 species of host. These results indicated that approximately 60% of the parasite taxa that infected fish in these lakes were absolute host specialists. The remaining 40% of parasite taxa had restricted host ranges, with most examples of parasite circulation limited to the 2 species of sympatric coregonid.

Population structure of three species of Anisakis nematodes recovered from Pacific sardines (Sardinops sagax) distributed throughout the California Current system.

Members of the Anisakidae are known to infect over 200 pelagic fish species and have been frequently used as biological tags to identify fish populations. Despite information on the global distribution of Anisakis species, there is little information on the genetic diversity and population structure of this genus, which could be useful in assessing the stock structure of their fish hosts. From 2005 through 2008, 148 larval anisakids were recovered from Pacific sardine (Sardinops sagax) in the California Current upwelling zone and were genetically sequenced. Sardines were captured off Vancouver Island, British Columbia in the north to San Diego, California in the south. Three species, Anisakis pegreffii, Anisakis simplex 'C', and Anisakis simplex s.s., were identified with the use of sequences from the internal transcribed spacers (ITS1 and ITS2) and the 5.8s subunit of the nuclear ribosomal DNA. The degree of nematode population structure was assessed with the use of the cytochrome c oxidase 2 (cox2) mitochondrial DNA gene. All 3 Anisakis species were distributed throughout the study region from 32°N to 50°N latitude. There was no association between sardine length and either nematode infection intensity or Anisakis species recovered. Larval Anisakis species and mitochondrial haplotype distributions from both parsimony networks and analyses of molecular variance revealed a panmictic distribution of these parasites, which infect sardines throughout the California Current ecosystem. Panmictic distribution of the larval Anisakis spp. populations may be a result of the presumed migratory pathways of the intermediate host (the Pacific sardine), moving into the northern portion of the California Current in summer and returning to the southern portion to overwinter and spawn in spring. However, the wider geographic range of paratenic (large piscine predators), and final hosts (cetaceans) can also explain the observed distribution pattern. As a result, the recovery of 3 Anisakis species and a panmictic distribution of their haplotypes could not be used to confirm or deny the presence of population subdivision of Pacific sardines in the California Current system.

Role of the Rap1 GTPase in astrocyte growth regulation.

Tuberous sclerosis complex (TSC) is an autosomal dominant syndrome in which affected individuals develop nervous system abnormalities that might reflect astrocyte dysfunction. The TSC2 gene product, tuberin, encodes a GTPase-activating protein (GAP) domain, which regulates the activity of Rap1 in vitro. To determine whether dysregulated Rap1, resulting from TSC2 inactivation, leads to increased astrocyte proliferation in vivo, we generated transgenic mice expressing activated Rap1(G12V) specifically in astrocytes. We observed no statistically significant difference in the number of astrocytes between wild-type and GFAP-Rap1(G12V) littermates in vivo; however, during log-phase growth, we observed a 25% increase in GFAP-Rap1(G12V) astrocyte doubling times compared to wild-type controls. This decreased proliferation was associated with delayed MAP kinase, but not AKT, activation. Lastly, to determine whether constitutive Rap1 activation could reverse the increased astrocyte proliferation observed in transgenic mice expressing oncogenic Ras(G12V), we generated transgenic mice expressing both Ras(G12V) and Rap1(G12V) in astrocytes. These double transgenic mice showed a striking reversion of the Ras(G12V) astrocyte growth phenotype. Collectively, these results argue that the tumor suppressor properties of tuberin are unlikely to be related to Rap1 inactivation and that Rap1 inhibits mitogenic Ras pathway signaling in astrocytes.

Astrocyte-specific TSC1 conditional knockout mice exhibit abnormal neuronal organization and seizures.

Persons affected with tuberous sclerosis complex (TSC) develop a wide range of neurological abnormalities including aberrant neuronal migration and seizures. In an effort to model TSC-associated central nervous system abnormalities in mice, we generated two independent lines of astrocyte-specific Tsc1 conditional knockout mice by using the Cre-LoxP system. Astrocyte-specific Tsc1-null mice exhibit electroencephalographically proven seizures after the first month of age and begin to die at 3 to 4 months. Tsc1-null mice show significant increases in astrocyte numbers throughout the brain by 3 weeks of age and abnormal neuronal organization in the hippocampus between 3 and 5 weeks. Moreover, cultured Tsc1-null astrocytes behave similar to wild-type astrocytes during log phase growth but demonstrate increased saturation density associated with reduced p27(Kip1) expression. Collectively, our results demonstrate that astrocyte-specific disruption of Tsc1 in mice provides a context-dependent growth advantage for astrocytes that results in abnormalities in neuronal organization and epilepsy.