Distinct mechanoreceptor pezo-1 isoforms modulate food intake in the nematode Caenorhabditis elegans.

Two PIEZO mechanosensitive cation channels, PIEZO1 and PIEZO2, have been identified in mammals, where they are involved in numerous sensory processes. While structurally similar, PIEZO channels are expressed in distinct tissues and exhibit unique properties. How different PIEZOs transduce force, how their transduction mechanism varies, and how their unique properties match the functional needs of the tissues they are expressed in remain all-important unanswered questions. The nematode Caenorhabditis elegans has a single PIEZO ortholog (pezo-1) predicted to have 12 isoforms. These isoforms share many transmembrane domains but differ in those that distinguish PIEZO1 and PIEZO2 in mammals. We used transcriptional and translational reporters to show that putative promoter sequences immediately upstream of the start codon of long pezo-1 isoforms predominantly drive green fluorescent protein (GFP) expression in mesodermally derived tissues (such as muscle and glands). In contrast, sequences upstream of shorter pezo-1 isoforms resulted in GFP expression primarily in neurons. Putative promoters upstream of different isoforms drove GFP expression in different cells of the same organs of the digestive system. The observed unique pattern of complementary expression suggests that different isoforms could possess distinct functions within these organs. We used mutant analysis to show that pharyngeal muscles and glands require long pezo-1 isoforms to respond appropriately to the presence of food. The number of pezo-1 isoforms in C. elegans, their putative differential pattern of expression, and roles in experimentally tractable processes make this an attractive system to investigate the molecular basis for functional differences between members of the PIEZO family of mechanoreceptors.

Preclinical Evaluation of Discorhabdins in Antiangiogenic and Antitumor Models.

Elements of the hypoxia inducible factor (HIF) transcriptional system, a key regulator of the cellular hypoxic response, are up-regulated in a range of cancer cells. HIF is fundamentally involved in tumor angiogenesis, invasion, and energy metabolism. Inhibition of the transcriptional activity of HIF may be of therapeutic benefit to cancer patients. We recently described the identification of two marine pyrroloiminoquinone alkaloids with potent activity in inhibiting the interaction between the oncogenic transcription factor HIF-1α and the coactivator protein p300. Herein, we present further characterization data for these two screening hits: discorhabdin H (1) and discorhabdin L (2), with a specific focus on their anti-angiogenic and anti-tumor effects. We demonstrated that only discorhabdin L (2) possesses excellent anti-angiogenic activity in inhibiting endothelial cell proliferation and tube formation, as well as decreasing microvessel outgrowth in the ex vivo rat aortic ring assay. We further showed that discorhabdin L (2) significantly inhibits in vivo prostate tumor growth in a LNCaP xenograft model. In conclusion, our findings suggest that discorhabdin L (2) represents a promising HIF-1α inhibitor worthy of further drug development.

How Much Is Enough in a Perfect World? Cultural Variation in Ideal Levels of Happiness, Pleasure, Freedom, Health, Self-Esteem, Longevity, and Intelligence.

The maximization principle-that people aspire to the highest possible level of something good if all practical constraints are removed-is a common yet untested assumption about human nature. We predict that in holistic cultures-where contradiction, change, and context are emphasized-ideal states of being for the self will be more moderate than in other cultures. In two studies ( Ns = 2,392 and 6,239), we asked this question: If participants could choose their ideal level of happiness, pleasure, freedom, health, self-esteem, longevity, and intelligence, what level would they choose? Consistent with predictions, results showed that maximization was less pronounced in holistic cultures; members of holistic cultures aspired to less happiness, pleasure, freedom, health, self-esteem, longevity, and IQ than did members of other cultures. In contrast, no differences emerged on ideals for society. The studies show that the maximization principle is not a universal aspect of human nature and that there are predictable cultural differences in people's notions of perfection.

From Theory to Action: Children's Community Pediatrics Behavioral Health System.

Integrated health care models attempt to cross the barrier between behavioral and medical worlds in order to improve access to quality care that meets the needs of the whole patient. Unfortunately, the integration of behavioral health and physical health providers in one space is not enough to actually promote integration. There are many models for promoting integration and collaboration within the primary care context. This article uses the experience of the Children's Community Pediatrics Behavioral Health Services system to highlight components of collaboration that should be considered in order to successfully integrate behavioral health within a medical home.

Dietary iron intake and serum ferritin concentration in 213 patients homozygous for the HFEC282Y hemochromatosis mutation.

BACKGROUND: HFEC282Y homozygotes have an increased risk for developing increased iron stores and related disorders. It is controversial whether dietary iron restrictions should be recommended to such individuals. OBJECTIVE: To determine whether dietary iron content influences iron stores in HFEC282Y homozygotes as assessed by serum ferritin concentration. DESIGN: Serum ferritin concentration was measured and a dietary iron questionnaire was completed as part of the evaluation of 213 HFEC282Y homozygotes who were identified through screening of >100,000 primary care patients at five HEmochromatosis and IRon Overload Screening (HEIRS) Study Field Centers in the United States and Canada. RESULTS: No significant relationships between serum ferritin concentration and dietary heme iron content, dietary nonheme iron content or reports of supplemental iron use were found. CONCLUSION: These results do not support recommending dietary heme or nonheme iron restrictions for HFEC282Y homozygotes diagnosed through screening in North America.

Screening for hereditary hemochromatosis: a systematic review for the U.S. Preventive Services Task Force.

BACKGROUND: The U.S. Preventive Services Task Force (USPSTF) has not previously considered screening for hereditary hemochromatosis for a recommendation as a clinical preventive service for primary care clinicians. PURPOSE: To conduct a focused systematic review of hereditary hemochromatosis screening relating to 2 USPSTF criteria, the burden of suffering and the potential effectiveness of a preventive intervention, to determine whether evidence is sufficient for a USPSTF recommendation. DATA SOURCES: MEDLINE, CINAHL, and Cochrane Library databases from 1966 through February 2005. The authors supplemented literature searches with source materials from experts in the field and the bibliographies of key reviews and included studies. STUDY SELECTION: Studies were retrieved to answer 3 key questions: 1) What is the risk for developing clinical hemochromatosis among those with a homozygous C282Y genotype? 2) Does earlier therapeutic phlebotomy of individuals with primary iron overload due to hereditary hemochromatosis reduce morbidity and mortality compared with treatment after diagnosis in routine clinical care? 3) Are there groups at increased risk for developing hereditary hemochromatosis that can be readily identified before genetic screening? The authors critically appraised studies using quality criteria specific to their design. DATA EXTRACTION: The authors abstracted all studies into evidence tables using condition definitions and diagnostic criteria. DATA SYNTHESIS: Data were insufficient to define a very precise estimate of penetrance. Available data suggest that up to 38% to 50% of C282Y homozygotes may develop iron overload, with up to 10% to 33% eventually developing hemochromatosis-associated morbidity. Prevalence of C282Y homozygosity is higher in family members of probands and other high-risk patient groups defined by signs, symptoms, and phenotypic screening. LIMITATIONS: This review considered genetic screening for HFE-related hereditary hemochromatosis in C282Y homozygotes only. Available research is limited, is based solely on observational designs, and is plagued by poor or inconsistent reporting. CONCLUSIONS: Research addressing genetic screening for hereditary hemochromatosis remains insufficient to confidently project the impact of, or estimate the benefit from, widespread or high-risk genetic screening for hereditary hemochromatosis.