Clock gene homologs lin-42 and kin-20 regulate circadian rhythms in C. elegans.

Circadian rhythms are endogenous oscillations in nearly all organisms, from prokaryotes to humans, allowing them to adapt to cyclical environments for close to 24 h. Circadian rhythms are regulated by a central clock, based on a transcription-translation feedback loop. One important protein in the central loop in metazoan clocks is PERIOD, which is regulated in part by Casein kinase 1ε/δ (CK1ε/δ) phosphorylation. In the nematode Caenorhabditis elegans, period and casein kinase 1ε/δ are conserved as lin-42 and kin-20, respectively. Here, we studied the involvement of lin-42 and kin-20 in the circadian rhythms of the adult nematode using a bioluminescence-based circadian transcriptional reporter. We show that mutations of lin-42 and kin-20 generate a significantly longer endogenous period, suggesting a role for both genes in the nematode circadian clock, as in other organisms. These phenotypes can be partially rescued by overexpression of either gene under their native promoter. Both proteins are expressed in neurons and epidermal seam cells, as well as in other cells. Depletion of LIN-42 and KIN-20, specifically in neuronal cells after development, was sufficient to lengthen the period of oscillating sur-5 expression. Therefore, we conclude that LIN-42 and KIN-20 are critical regulators of the adult nematode circadian clock through neuronal cells.

A conserved chronobiological complex times C. elegans development.

The mammalian PAS-domain protein PERIOD (PER) and its C. elegans orthologue LIN-42 have been proposed to constitute an evolutionary link between two distinct, circadian and developmental, timing systems. However, while the function of PER in animal circadian rhythms is well understood molecularly and mechanistically, this is not true for the function of LIN-42 in timing rhythmic development. Here, using targeted deletions, we find that the LIN-42 PAS domains are dispensable for the protein's function in timing molts. Instead, we observe arrhythmic molts upon deletion of a distinct sequence element, conserved with PER. We show that this element mediates stable binding to KIN-20, the C. elegans CK1δ/ε orthologue. We demonstrate that CK1δ phosphorylates LIN-42 and define two conserved helical motifs, CK1δ-binding domain A (CK1BD-A) and CK1BD-B, that have distinct roles in controlling CK1δ-binding and kinase activity in vitro. KIN-20 and the LIN-42 CK1BD are required for proper molting timing in vivo. These interactions mirror the central role of a stable circadian PER-CK1 complex in setting a robust ~24-hour period. Hence, our results establish LIN-42/PER - KIN-20/CK1δ/ε as a functionally conserved signaling module of two distinct chronobiological systems.

Regulation of the circadian clock in C. elegans by clock gene homologs kin-20 and lin-42.

Circadian rhythms are endogenous oscillations present in nearly all organisms from prokaryotes to humans, allowing them to adapt to cyclical environments close to 24 hours. Circadian rhythms are regulated by a central clock, which is based on a transcription-translation feedback loop. One important protein in the central loop in metazoan clocks is PERIOD, which is regulated in part by Casein kinase 1 ε/δ (CK1 ε/δ ) phosphorylation. In the nematode Caenorhabditis elegans , period and casein kinase 1ε/δ are conserved as lin-42 and kin-20 , respectively. Here we studied the involvement of lin-42 and kin-20 in circadian rhythms of the adult nematode using a bioluminescence-based circadian transcriptional reporter. We show that mutations of lin-42 and kin-20 generate a significantly longer endogenous period, suggesting a role for both genes in the nematode circadian clock, as in other organisms. These phenotypes can be partially rescued by overexpression of either gene under their native promoter. Both proteins are expressed in neurons and seam cells, a population of epidermal stem cells in C. elegans that undergo multiple divisions during development. Depletion of LIN-42 and KIN-20 specifically in neuronal cells after development was sufficient to lengthen the period of oscillating sur-5 expression. Therefore, we conclude that LIN-42 and KIN-20 are critical regulators of the adult nematode circadian clock through neuronal cells.

Exploring the perspectives of patients about their care experience: identifying what patients perceive are important qualities in cancer care.

INTRODUCTION: Delivering person-centered care begins with understanding perspectives of individuals who are recipients of care about their experiences and what constitutes a "positive" experience. METHODS: This project explored views of individuals with cancer regarding their care experiences and identified aspects of care patients thought were important through a qualitative analysis of data from the Ambulatory Oncology Patient Satisfaction Survey (AOPSS). Permission was obtained from seven Canadian provinces to access de-identified written comments to a final open-ended question on the survey: Is there anything else you would like to tell us about your cancer care experience? The descriptive qualitative analysis was guided by two questions: (1) what is the nature of the written comments and (2) what are key ideas expressed about care experiences? Key ideas were collated across provinces to identify significant themes within the national sample. RESULTS: The sample included comments from 6232 individuals. A total of 42.5% comments were positive, 29.7% were negative, and 19.8% were mixed. Four broad themes were identified from the comments: (1) characteristics of a "positive" experience, (2) personal care, (3) interaction with health care providers, and (4) service delivery. Respondents cited being treated as a person with respect and dignity, clear communication, access to relevant and timely information, and care that takes their needs into account as important aspects. Communication, consistency, and ongoing interactions with staff were highlighted as essential elements of a positive experience, yet areas where improvements in care are necessary. CONCLUSION: Patients reported a range of aspects that contribute to positive and negative care experiences which can be used to guide quality improvement initiatives in cancer centers. Results underscore the importance of having data collection systems in place to ensure agencies and providers have timely feedback about patients' experiences and concerns in order to provide responsive and individualized care.

Cancer drug expenditure in British Columbia and Saskatchewan: a trend analysis.

BACKGROUND: Expenditure on systemic therapy for cancer has been increasing quickly owing to population growth, increased use, both in the number of users and in prescription volume, and rising drug prices. Our objective was to describe trends in expenditure in British Columbia and Saskatchewan's cancer care systems and to elucidate these drivers of growth. METHODS: In this trend analysis, we obtained pharmacy dispensing records from the BC Cancer and Saskatchewan Cancer Agency pharmacies for all anticancer therapies dispensed in 2006-2013. We calculated total annual expenditure directly from the data and conducted a trend analysis of crude and standardized annual expenditure using generalized linear models. We estimated trends in the following components of total expenditure: cancer incidence, number of systemic therapy users per incident case, number of dispensed prescriptions per user and cost per prescription. Analysis was stratified by patient age group, cancer site and route of administration (oral or intravenous/other). RESULTS: Expenditure on systemic therapies, adjusted for population growth and aging, increased an average of 9.2% (95% confidence interval [CI] 7.2 to 11.2) per year in Saskatchewan and 6.4% (95% CI 5.3 to 7.6) per year in BC. Growth in expenditure on orally administered agents was more than 2 times higher than growth in expenditure on intravenous/other agents. Growth rates varied significantly by cancer site. In both provinces, rising cost per prescription was the largest contributor to overall growth. INTERPRETATION: Price is the primary driver of growth in systemic therapy expenditure in both BC and Saskatchewan. Understanding the mechanisms of expenditure growth may inform system planning and support policy-makers' efforts to manage rising costs.

Diabetic retinopathy screening with pharmacy-based teleophthalmology in a semiurban setting: a cost-effectiveness analysis.

BACKGROUND: Diabetic eye complications are the leading cause of visual loss among working-aged people. Pharmacy-based teleophthalmology has emerged as a possible alternative to in-person examination that may facilitate compliance with evidence-based recommendations and reduce barriers to specialized eye care. The objective of this study was to estimate the cost-effectiveness of mobile teleophthalmology screening compared with in-person examination (primary care) for the diabetic population residing in semiurban areas of southwestern Ontario. METHODS: A decision tree was constructed to compare in-person examination (comparator program) versus pharmacy-based teleophthalmology (intervention program). The economic model was designed to identify patients with more than minimal diabetic retinopathy, manifested by at least 1 microaneurysm at examination (modified Airlie House classification grade of ≥ 20). Cost-effectiveness was assessed as cost per case detected (true-positive result) and cost per case correctly diagnosed (including true-positive and true-negative results). RESULTS: The cost per case detected was $510 with in-person examination and $478 with teleophthalmology, and the cost per case correctly diagnosed was $107 and $102 respectively. The incremental cost-effectiveness ratio was $314 per additional case detected and $73 per additional case correctly diagnosed. Use of pharmacologic dilation and health care specialists' fees were the most important cost drivers. INTERPRETATION: The study showed that a compound teleophthalmology program in a semiurban community would be more effective but more costly than in-person examination. The findings raise the question of whether the benefits of pharmacy-based teleophthalmology in semiurban areas, where in-person examination is still available, are equivalent to those observed in remote communities. Further study is needed to investigate the impact of this program on the prevention of severe vision loss and quality of life in a semiurban setting.

CagA EPIYA polymorphisms in Colombian Helicobacter pylori strains and their influence on disease-associated cellular responses.

AIM: To investigate the influence of the CagA diversity in Helicobacter pylori (H. pylori) strains from Colombia on the host cell biology. METHODS: Eighty-four H. pylori-cagA positive strains with different Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs patterns, isolated from patients with gastritis (n = 17), atrophic gastritis (n = 17), duodenal ulcer (n = 16), intestinal metaplasia (n = 16) and gastric cancer (n = 18), were included. To determine the integrity of the cag pathogenicity island (cagPAI) we evaluated the presence of cagA, cagT, cagE, and cag10 genes by polymerase chain reaction. AGS gastric epithelial cells were infected with each strain and assayed for translocation and tyrosine phosphorylation of CagA by western blot, secretion of interleukin-8 (IL-8) by enzyme-linked immuno sorbent assay after taking supernatants from cocultures and cell elongation induction. For cell elongation quantification, coculture photographs were taken and the proportion of "hummingbird" cells (> 15 µm) was determined. RESULTS: Overall 72% (60/84) of the strains were found to harbor a functional cagPAI. Levels of phosphorylated CagA were significantly higher for isolates from duodenal ulcer than the ones in strains from gastritis, atrophic gastritis, intestinal metaplasia and gastric cancer (49.1% ± 23.1% vs 21.1% ± 19.5%, P < 0.02; 49.1% ± 23.1% vs 26.2% ± 14.8%, P < 0.045; 49.1% ± 23.1% vs 21.5% ± 19.5%, P < 0.043 and 49.1% ± 23.1% vs 29.5% ± 27.1%, P < 0.047 respectively). We observed variable IL-8 expression levels ranging from 0 to 810 pg/mL and from 8.8 to 1442 pg/mL at 6 h and 30 h post-infection, respectively. cagPAI-defective strains did not induce detectable levels of IL-8 at 6 h post-infection. At 30 h post-infection all strains induced IL-8 expression in AGS cells, although cagPAI-defective strains induced significantly lower levels of IL-8 than strains with a functional cagPAI (57.1 ± 56.6 pg/mL vs 513.6 ± 338.6 pg/mL, P < 0.0001). We did not observe differences in the extent of cell elongation induction between strains with a functional or a defective cagPAI in 6 h cocultures. At 24 h post infection strains with functional cagPAI showed high diversity in the extent of hummingbird phenotype induction ranging from 7% to 34%. cagPAI defective strains induced significantly lower levels of elongation than strains with functional cagPAI with one or more than one EPIYA-C motif (15.1% ± 5.2% vs 18.9% ± 4.7%, P < 0.03; and 15.1% ± 5.2% vs 20.0% ± 5.1%, P < 0.003 respectively). No differences were observed in cellular elongation induction or IL-8 expression among H. pylori strains bearing one and more than one EPIYA-C motifs, neither at 6 h nor at 24 h of coculture. There were no associations between the levels of induction of cell elongation or IL-8 expression and number of EPIYA motifs or pathology. CONCLUSION: The present work describes a lack of association between H. pylori CagA protein EPIYA motifs variations from Colombian isolates and disease-associated cellular responses.