Intravenous supplementation type and volume are associated with 1-year outcome and major complications in patients with chronic intestinal failure.

BACKGROUND AND AIM: No marker to categorise the severity of chronic intestinal failure (CIF) has been developed. A 1-year international survey was carried out to investigate whether the European Society for Clinical Nutrition and Metabolism clinical classification of CIF, based on the type and volume of the intravenous supplementation (IVS), could be an indicator of CIF severity. METHODS: At baseline, participating home parenteral nutrition (HPN) centres enrolled all adults with ongoing CIF due to non-malignant disease; demographic data, body mass index, CIF mechanism, underlying disease, HPN duration and IVS category were recorded for each patient. The type of IVS was classified as fluid and electrolyte alone (FE) or parenteral nutrition admixture (PN). The mean daily IVS volume, calculated on a weekly basis, was categorised as <1, 1-2, 2-3 and >3 L/day. The severity of CIF was determined by patient outcome (still on HPN, weaned from HPN, deceased) and the occurrence of major HPN/CIF-related complications: intestinal failure-associated liver disease (IFALD), catheter-related venous thrombosis and catheter-related bloodstream infection (CRBSI). RESULTS: Fifty-one HPN centres included 2194 patients. The analysis showed that both IVS type and volume were independently associated with the odds of weaning from HPN (significantly higher for PN <1 L/day than for FE and all PN >1 L/day), patients' death (lower for FE, p=0.079), presence of IFALD cholestasis/liver failure and occurrence of CRBSI (significantly higher for PN 2-3 and PN >3 L/day). CONCLUSIONS: The type and volume of IVS required by patients with CIF could be indicators to categorise the severity of CIF in both clinical practice and research protocols.

Home parenteral nutrition provision modalities for chronic intestinal failure in adult patients: An international survey.

BACKGROUND & AIMS: The safety and effectiveness of a home parenteral nutrition (HPN) program depends both on the expertise and the management approach of the HPN center. We aimed to evaluate both the approaches of different international HPN-centers in their provision of HPN and the types of intravenous supplementation (IVS)-admixtures prescribed to patients with chronic intestinal failure (CIF). METHODS: In March 2015, 65 centers from 22 countries enrolled 3239 patients (benign disease 90.1%, malignant disease 9.9%), recording the patient, CIF and HPN characteristics in a structured database. The HPN-provider was categorized as health care system local pharmacy (LP) or independent home care company (HCC). The IVS-admixture was categorized as fluids and electrolytes alone (FE) or parenteral nutrition, either commercially premixed (PA) or customized to the individual patient (CA), alone or plus extra FE (PAFE or CAFE). Doctors of HPN centers were responsible for the IVS prescriptions. RESULTS: HCC (66%) was the most common HPN provider, with no difference noted between benign-CIF and malignant-CIF. LP was the main modality in 11 countries; HCC prevailed in 4 European countries: Israel, USA, South America and Oceania (p < 0.001). IVS-admixture comprised: FE 10%, PA 17%, PAFE 17%, CA 38%, CAFE 18%. PA and PAFE prevailed in malignant-CIF while CA and CAFE use was greater in benign-CIF (p < 0.001). PA + PAFE prevailed in those countries where LP was the main HPN-provider and CA + CAFE prevailed where the main HPN-provider was HCC (p < 0.001). CONCLUSIONS: This is the first study to demonstrate that HPN provision and the IVS-admixture differ greatly among countries, among HPN centers and between benign-CIF and cancer-CIF. As both HPN provider and IVS-admixture types may play a role in the safety and effectiveness of HPN therapy, criteria to homogenize HPN programs are needed so that patients can have equal access to optimal CIF care.

Assessing Patient Preferences for Intestinal Failure Management Using the Time Trade-Off Methodology.

BACKGROUND: There are limited management options available for people with Type III intestinal failure (IF), with home parenteral nutrition (HPN) being the main treatment option. The aim of this research is to compare patient preferences in managing Type III IF using time trade-off (TTO) methodology and to determine which factors have the greatest impact on health-related quality of life (HRQoL). METHODS: An interviewer-administered telephone survey was conducted on a cross-sectional cohort of 19 HPN participants. The survey was designed to measure HRQoL using a TTO methodology. Four different treatment options were presented, and participants decided how many years of life they would trade to have access to the treatment and hence a different health state. The 4 scenarios included reduction in line infections, optimization of care, small bowel growth (teduglutide), and intestinal transplantation. Health state utility scores were calculated. RESULTS: The median health utility score for optimization of care and small bowel growth (teduglutide) were lowest (0.5; range 0-1) meaning a greater desire for this treatment. Intestinal transplant had the highest median utility score (1.0; range 0-1) indicating less willingness for this treatment option. CONCLUSIONS: This is the first known study to use TTO methodology assessing treatment options in people with IF requiring HPN. Results indicate people requiring HPN make careful decisions when considering treatment options. Facilities providing HPN services should focus on optimization of current care, which is highly valued by their patients.

Development of consensus on models of care in adults with intestinal failure using a modified Delphi approach.

BACKGROUND AND AIM: The aims of this study were to establish consensus on service delivery models for management of Type III intestinal failure (IF) and home parenteral nutrition (HPN) within the Australian health-care system and to identify barriers and enablers in moving towards this ideal model. METHODS: A modified Delphi methodology was utilized to survey experts working in Type III IF HPN. The panel comprised physicians, dietitians, nurses, and pharmacists from 18 of the 20 adult Type III IF HPN centres across Australia. The study consisted of two rounds of email administered questionnaires developed around four key areas of health service delivery: access to services, clinical care, service guidance, and models of care. Open-ended responses were evaluated via an inductive thematic approach to identify areas of consensus. Experts reviewed the final report to consolidate consensus and validity. RESULTS: There was >80% consensus that an ideal team should consist of a physician, nurse, dietitian, pharmacist, and access to psychological support. Consensus supported the need for updated guidelines (75%) and a hub and spoke model of care (82%). However, further consultation is required in order to establish consensus around the use of HPN in the palliative oncology setting (69%). CONCLUSIONS: This consensus provides a framework within which health professionals, managers, policy-makers, and consumer groups can move towards optimal management for Type III IF HPN patients. Advocacy and a review of service delivery across Australia are now required to facilitate the ideal model of care identified.

Effects of in utero exposure of C57BL/6J mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin on epidermal permeability barrier development and function.

BACKGROUND: Development of the epidermal permeability barrier (EPB) is essential for neonatal life. Defects in this barrier are found in many skin diseases such as atopic dermatitis. OBJECTIVE: We investigated the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the development and function of the EPB. METHODS: Timed-pregnant C57BL/6J mice were gavaged with corn oil or TCDD (10 µg/kg body weight) on gestation day 12. Embryos were harvested on embryonic day (E) 15, E16, E17, and postnatal day (PND) 1. RESULTS: A skin permeability assay showed that TCDD accelerated the development of the EPB, beginning at E15. This was accompanied by a significant decrease in transepidermal water loss (TEWL), enhanced stratification, and formation of the stratum corneum (SC). The levels of several ceramides were significantly increased at E15 and E16. PND1 histology revealed TCDD-induced acanthosis and epidermal hyperkeratosis. This was accompanied by disrupted epidermal tight junction (TJ) function, with increased dye leakage at the terminal claudin-1-staining TJs of the stratum granulosum. Because the animals did not have enhanced rates of TEWL, a commonly observed phenotype in animals with TJ defects, we performed tape-stripping. Removal of most of the SC resulted in a significant increase in TEWL in TCDD-exposed PND1 pups compared with their control group. CONCLUSIONS: These findings demonstrate that in utero exposure to TCDD accelerates the formation of an abnormal EPB with leaky TJs, warranting further study of environmental exposures, epithelial TJ integrity, and atopic disease.

A mouse model for osseous heteroplasia.

GNAS/Gnas encodes G(s)α that is mainly biallelically expressed but shows imprinted expression in some tissues. In Albright Hereditary Osteodystrophy (AHO) heterozygous loss of function mutations of GNAS can result in ectopic ossification that tends to be superficial and attributable to haploinsufficiency of biallelically expressed G(s)α. Oed-Sml is a point missense mutation in exon 6 of the orthologous mouse locus Gnas. We report here both the late onset ossification and occurrence of benign cutaneous fibroepithelial polyps in Oed-Sml. These phenotypes are seen on both maternal and paternal inheritance of the mutant allele and are therefore due to an effect on biallelically expressed G(s)α. The ossification is confined to subcutaneous tissues and so resembles the ossification observed with AHO. Our mouse model is the first with both subcutaneous ossification and fibroepithelial polyps related to G(s)α deficiency. It is also the first mouse model described with a clinically relevant phenotype associated with a point mutation in G(s)α and may be useful in investigations of the mechanisms of heterotopic bone formation. Together with earlier results, our findings indicate that G(s)α signalling pathways play a vital role in repressing ectopic bone formation.

Wingless signaling directly regulates cyclin E expression in proliferating embryonic PNS precursor cells.

Cell proliferation and cell type specification are coordinately regulated during normal development. Cyclin E, a key G1/S cell cycle regulator, is regulated by multiple tissue-specific enhancers resulting in dynamic expression during Drosophila development. Here, we further characterized the enhancer that regulates cyclin E expression in the developing peripheral nervous system (PNS) and show that multiple sequence elements are required for the full cyclin E PNS enhancer activity. We further show that Wg signaling is important for the expression of cyclin E in the sensory organ precursor (SOP) cells through two conserved TCF binding sites. Blocking Wg signaling does not completely block SOP cell formation but does completely block SOP cell proliferation as well as the subsequent differentiation.

Metabolic regulation of sodium-calcium exchange by intracellular acyl CoAs.

The sodium-calcium exchanger (NCX) is a critical mediator of calcium homeostasis. In the heart, NCX1 predominantly operates in forward mode to extrude Ca(2+); however, reverse-mode NCX1 activity during ischemia/reperfusion (IR) contributes to Ca(2+) loading and electrical and contractile dysfunction. IR injury has also been associated with altered fat metabolism and accumulation of long-chain acyl CoA esters. Here, we show that acyl CoAs are novel, endogenous activators of reverse-mode NCX1 activity, exhibiting chain length and saturation dependence, with longer chain saturated acyl moieties being the most effective NCX1 activators. These results implicate dietary fat composition as a plausible determinant of IR injury. We further show that acyl CoAs may interact directly with the XIP (exchanger inhibitory peptide) sequence, a known region of anionic lipid modulation, to dynamically regulate NCX1 activity and Ca(2+) homeostasis. Additionally, our findings have broad implications for the coupling of Ca(2+) homeostasis to fat metabolism in a variety of tissues.

African Americans' knowledge of cancer genetic counseling: an examination of information delivery.

Two groups totaling 44 African Americans from two community churches were examined to determine the impact of two presentations on the uptake of genetic counseling educational material. Both presentations were developed with adult learning theory principles and offered information about cancer genetic risk assessment. The second presentation was enhanced to include a description, with pictures, of a culturally relevant fictitious family's course through risk assessment. Hypotheses were: a) knowledge would increase for each group and b) culturally relevant pictures and a family description would increase satisfaction with the presentation. A pre- and post-assessment was conducted with pre-assessment including demographic information and a knowledge questionnaire. Post-assessment included the knowledge questionnaire and a presentation satisfaction questionnaire. Independent t tests were used to analyze the gain scores between pre- and post-knowledge questionnaires and the satisfaction scores between groups. These results are discussed in terms of decreasing disparities in African Americans' participation in risk assessment through community outreach educational programs.

Functional interaction between mouse erbB3 and wild-type rat c-neu in transgenic mouse mammary tumor cells.

INTRODUCTION: Co-expression of several receptor tyrosine kinases (RTKs), including erbB2 and erbB3, is frequently identified in breast cancers. A member of the RTK family, the kinase-deficient erbB3 can activate downstream signaling via heterodimer formation with erbB2. We studied the expression of RTK receptors in mammary tumors from the wild-type (wt) rat c-neu transgenic model. We hypothesized that physical and functional interactions between the wt rat neu/ErbB2 transgene and mouse ErbB3-encoded proteins could occur, activating downstream signaling and promoting mammary oncogenesis. METHODS: Immunohistochemical and Western blot analyses were performed to study the expression of rat c-neu/ErbB2 and mouse erbB3 in mammary tumors and tumor-derived cell lines from the wt rat c-neu transgenic mice. Co-immunoprecipitation methods were employed to quantitate heterodimerization between the transgene-encoded protein erbB2 and the endogenous mouse erbB3. Tumor cell growth in response to growth factors, such as Heregulin (HRG), epidermal growth factor (EGF), or insulin-like growth factor-1 (IGF-1), was also studied. Post-HRG stimulation, activation of the RTK downstream signaling was determined by Western blot analyses using antibodies against phosphorylated Akt and mitogen-activated protein kinase (MAPK), respectively. Specific inhibitors were then used with cell proliferation assays to study the phosphoinositide-3 kinase (PI-3K)/Akt and MAPK kinase (MEK)/MAPK pathways as possible mechanisms of HRG-induced tumor cell proliferation. RESULTS: Mammary tumors and tumor-derived cell lines frequently exhibited elevated co-expression of erbB2 and erbB3. The transgene-encoded protein erbB2 formed a stable heterodimer complex with endogenous mouse erbB3. HRG stimulation promoted physical and functional erbB2/erbB3 interactions and tumor cell growth, whereas no response to EGF or IGF-1 was observed. HRG treatment activated both the Akt and MAPK pathways in a dose- and time-dependent manner. Both the PI-3K inhibitor LY 294002 and MEK inhibitor PD 98059 significantly decreased the stimulatory effect of HRG on tumor cell proliferation. CONCLUSION: The co-expression of wt rat neu/ErbB2 transgene and mouse ErbB3, with physical and functional interactions between these two species of RTK receptors, was demonstrated. These data strongly suggest a role for erbB3 in c-neu (ErbB2)-associated mammary tumorigenesis, as has been reported in human breast cancers.

Identification and pharmacological characterization of sarcolemmal ATP-sensitive potassium channels in the murine atrial HL-1 cell line.

Activation of ATP-sensitive potassium (KATP) channels is known to have cardioprotective effects during periods of ischemia and reperfusion, making these channels important targets for clinical drug discovery. Using electrophysiological techniques we identify KATP channels in a mouse atrial cell line (HL-1). HL-1 KATP channels exhibited a concentration-dependent inhibition by ATP (IC50 = 23.3 +/- 3.2 microM), a unitary single-channel conductance of 55 pS, and sensitivity to the isoform-specific KATP channel opener P1075 and inhibitor HMR1098. Adenoviral infection of a dominant-negative Kir6.2 subunit significantly reduced the P1075-sensitive sarcKATP current. Taken together, the data indicate that HL-1 KATP channels are composed of sulfonylurea receptor isoform SUR2A coupled to the pore-forming Kir6.2 subunit--the molecular makeup of sarcKATP channels found in native cardiac myocytes. Pharmacological activation of HL-1 cell KATP channels also resulted in action potential shortening. Using the membrane potential-sensitive dye DiBac4(3), we demonstrated that the sarcKATP channel opener P1075 (20 microM) produced a concentration-dependent hyperpolarization of a monolayer of HL-1 cells that could be reversed by channel inhibition with HMR1098 (20 microM). We conclude that the HL-1 cells are an excellent cell line for studying cardiac sarcKATP channels, and these cells may also provide an important tool for the testing of novel pharmacological modulators of KATP channels in fluorescence-based assays.

Mammary tumor heterogeneity in wt-ErbB-2 transgenic mice.

Phenotypic and biological heterogeneity was studied in a single transgenic mouse model to determine the level of biological variance. We analyzed 1,258 tumors from 417 MMTV-wt-ErbB-2 transgenic mice, subdivided by casein or soy-based dietary randomization and hormonal treatment. Variance in tumor histologic features, growth pattern, invasion, metastases, and multi-focality were detected in untreated and treated mice. Ninety-three percent (1,174/1,258) of tumors had the solid growth pattern widely reported in this model. However, among the solid tumors, a spectrum of growth patterns, from well-circumscribed tumors with a pseudocapsule to locally invasive or highly aggressive, metastatic subtype, was observed. Of the non-solid tumors, glandular features were prominent in 84 (7%). Adenocarcinomas included papillary, acinar/glandular, and adenosquamous subtypes. Adenosquamous tumors were exclusively observed in the group of mice treated on a short-term basis with estrogen. In contrast to the reported literature for this transgenic mouse model, mammary tumors were multifocal in the majority of cases (303 of 417 mice, or 73%). Results of this extensive study of a single transgenic model of mammary tumorigenesis indicate phenotypic and biological heterogeneity not previously associated with this transgenic mouse. These data support a complex, multistep process of carcinogenesis and clonal evolution, with biological and phenotypic variance similar to that observed in human mammary cancer development.

Control of DNA replication and chromosome ploidy by geminin and cyclin A.

Alteration of the control of DNA replication and mitosis is considered to be a major cause of genome instability. To investigate the mechanism that controls DNA replication and genome stability, we used the RNA silencing-interference technique (RNAi) to eliminate the Drosophila geminin homologue from Schneider D2 (SD2) cells. Silencing of geminin by RNAi in SD2 cells leads to the cessation of mitosis and asynchronous overreplication of the genome, with cells containing single giant nuclei and partial ploidy between 4N and 8N DNA content. The effect of geminin deficiency is completely suppressed by cosilencing of Double parked (Dup), the Drosophila homologue of Cdt1, a replication factor to which geminin binds. The geminin deficiency-induced phenotype is also partially suppressed by coablation of Chk1/Grapes, indicating the involvement of Chk1/Grapes in the checkpoint control in response to overreplication. We found that the silencing of cyclin A, but not of cyclin B, also promotes the formation of a giant nucleus and overreplication. However, in contrast to the effect of geminin knockout, cyclin A deficiency leads to the complete duplication of the genome from 4N to 8N. We observed that the silencing of geminin causes rapid downregulation of Cdt1/Dup, which may contribute to the observed partial overreplication in geminin-deficient cells. Analysis of cyclin A and geminin double knockout suggests that the effect of cyclin A deficiency is dominant over that of geminin deficiency for cell cycle arrest and overreplication. Together, our studies indicate that both cyclin A and geminin are required for the suppression of overreplication and for genome stability in Drosophila cells.