High‐temperature‐induced reductions in cropping in everbearing strawberries (Fragaria × ananassa) are associated with reduced pollen performance

Heat‐induced short‐term reductions in cropping (often referred to as ‘thermodormancy’ by UK strawberry growers) occur frequently in extended‐season everbearing strawberry production in the UK. A 2‐year study evaluated the effects of high temperatures on the performance of pollen in two everbearing strawberry cultivars (cvs ‘Everest’ and ‘Diamante’). Pollen from both cultivars lost its ability to germinate following exposure to a period of high temperature (30/20°C day/night). However, after termination of the high‐temperature episode, germination capacity recovered to levels similar to control plants that were not exposed to high temperature. High temperature also resulted in slower rates of pollen tube growth. As a result, only a small proportion of high‐temperature‐affected flowers developed into fruits. These results suggest that heat‐induced reductions in cropping in everbearing strawberries are associated with reduced pollen performance.     

miR-888 is an expressed prostatic secretions-derived microRNA that promotes prostate cell growth and migration

microRNAs (miRNAs) are a growing class of small non-coding RNAs that exhibit widespread dysregulation in prostate cancer. We profiled miRNA expression in syngeneic human prostate cancer cell lines that differed in their metastatic potential in order to determine their role in aggressive prostate cancer. miR-888 was the most differentially expressed miRNA observed in human metastatic PC3-ML cells relative to non-invasive PC3-N cells, and its levels were higher in primary prostate tumors from cancer patients, particularly those with seminal vesicle invasion. We also examined a novel miRNA-based biomarker source called expressed prostatic secretions in urine (EPS urine) for miR-888 expression and found that its levels were preferentially elevated in prostate cancer patients with high-grade disease. These expression studies indicated a correlation for miR-888 in disease progression. We next tested how miR-888 regulated cancer-related pathways in vitro using human prostate cancer cell lines. Overexpression of miR-888 increased proliferation and migration, and conversely inhibition of miR-888 activity blocked these processes. miR-888 also increased colony formation in PC3-N and LNCaP cells, supporting an oncogenic role for this miRNA in the prostate. Our data indicates that miR-888 functions to promote prostate cancer progression and can suppress protein levels of the tumor suppressor genes RBL1 and SMAD4. This miRNA holds promise as a diagnostic tool using an innovative prostatic fluid source as well as a therapeutic target for aggressive prostate cancer.     

Evaluating “Hot Spots” of Soil Contamination (Redux)

Every day, thousands of soil samples are collected from properties suspected of being contaminated. The samples are sent to laboratories where the chemical constituents are quantified. Frequently, one or more samples are identified as constituting a “hot spot” of soil contamination. The consequences of such a determination—more sampling, more remediation, more reporting—are often quite expensive. Yet despite the often costly consequences of identifying a “hot spot,” there appears no supportable methodology for objectively deciding which spots are “hot” and which are “not.” This can lead to situations where sampling episodes are required to demonstrate that there is not a problem, even though just exactly what would comprise a “problem” is not particularly clear and sometimes is not stated. The authors provide a review and analysis of common and published information concerning “hot spots.” They then present a different point of view about “hot spots” from those in common practice, a point of view that will challenge many environmental professionals to reconsider how they evaluate sampling results.     

Quantitative determination of amino acid racemization in heat-alkali-treated melanotropins: Implications for peptide hormone structure-function studies

The treatment of frog skins (in vitro) and frogs (in vivo) with melanotropins that have been heated briefly in aqueous alkali resulted in prolonged skin darkening. It has been postulated that this increase in melanotropic activity is related to the partial racemization of amino acid residues of the melanotropins. Quantitative determination of the extent of racemization of eight amino acids (Val, Pro, Met, Phe, Glu, Asp, Nle, Ser) present in α-melanotropin (α-MSH), [4-norleucine]-α-MSH, β_porcine-melanotropin (β_p-MSH), and [7-norleucine]-β_p-MSH after brief heat-alkali treatment, was accomplished using a high-resolution gas chromatographic technique. Phenylalanine-7 in α-MSH and [4-norleucine]-α-MSH and phenylalanine-10 in β_p-MSH and [7-norleucine]-β_p-MSH were found to be partially racemized to a greater extent than expected. Other amino acid residues were also racemized to unexpected degrees. The subsequent synthesis of an α-MSH analog containing d-phenylalanine-7, [4-norleucine, 7-d-phenylalanine]-α-MSH, resulted in a highly potent melanotropin with ultralong biological activity, as determined by frog skin bioassay, stimulation of mouse melanoma cell tyrosinase activity, and activation of mouse melanoma adenylate cyclase.     

Approaches for quantifying energy intake and %calorie restriction during calorie restriction interventions in humans: the multicenter CALERIE study

Calorie restriction (CR) is a component of most weight loss interventions and a potential strategy to slow aging. Accurate determination of energy intake and %CR is critical when interpreting the results of CR interventions; this is most accurately achieved using the doubly labeled water method to quantify total energy expenditure (TEE). However, the costs and analytical requirements of this method preclude its repeated use in many clinical trials. Our aims were to determine 1) the optimal TEE assessment time points for quantifying average energy intake and %CR during long-term CR interventions and 2) the optimal approach for quantifying short-term changes in body energy stores to determine energy intake and %CR during 2-wk DLW periods. Adults randomized to a CR intervention in the multicenter CALERIE study underwent measurements of TEE by doubly labeled water and body composition at baseline and months 1, 3, and 6. Average %CR achieved during the intervention was 24.9 ± 8.7%, which was computed using an approach that included four TEE assessment time points (i.e., TEE(baseline, months 1, 3, and 6)) plus the 6-mo change in body composition. Approaches that included fewer TEE assessments yielded %CR values of 23.4 ± 9.0 (TEE(baseline,) months 3 and 6), 25.0 ± 8.7 (TEE(baseline,) months 1 and 6), and 20.9 ± 7.1% (TEE(baseline, month 6)); the latter approach differed significantly from approach 1 (P < 0.001). TEE declined 9.6 ± 9.9% within 2-4 wk of CR beginning and then stabilized. Regression of daily home weights provided the most reliable estimate of short-term change in energy stores. In summary, optimal quantification of energy intake and %CR during weight loss necessitates a TEE measurement within the first month of CR to capture the rapid reduction in TEE.