Effect of Ramadan fasting on some indices of insulin resistance and components of the metabolic syndrome in healthy male adults

The purpose of the present study was to evaluate the effect of Ramadan fasting on insulin sensitivity in subjects with the metabolic syndrome. Males (n 55; age 34.1 (SD 8.9) years) with the metabolic syndrome were studied. Blood pressure, waist circumference, body weight, HDL-cholesterol (HDL-C), TAG, fasting plasma glucose (FPG), fasting blood insulin and insulin resistance indices (quantitative insulin sensitivity check index (QUICKI), homeostasis model assessment of insulin resistance (HOMA-IR) and reciprocal index of HOMA-IR (1/HOMA-IR)) were evaluated before and after 30 d of Ramadan fasting (two meals at 12 h intervals). The dietary intake was estimated by 24 h recall before and after fasting. The total daily energy intake was decreased by 234.6 (SD 88.2) kJ/d in the fasting period (P = 0.005). 1/HOMA-IR, QUICKI and HDL-C were significantly increased (P = 0.005, P = 0.001 and P = 0.004) and FPG significantly decreased (P < 0.005) after fasting. Simple linear regression analysis demonstrated that HOMA-IR, 1/HOMA-IR and QUICKI were related to waist circumference after intervention (r 0.458, P < 0.001; r -0.396, P < 0.05; r -0.342, P < 0.05). In conclusion, the present study showed that the combined change in the number and timing of meals and portioning of the entire intake into only two meals per d may increase insulin sensitivity in subjects with the metabolic syndrome even when the decrease in energy consumption is minimal. © The Authors 2008

Dormant Tumor Cell Vaccination: A Mathematical Model of Immunological Dormancy in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) is a molecular subtype of breast malignancy with a poor clinical prognosis. There is growing evidence that some chemotherapeutic agents induce an adaptive anti-tumor immune response. This reaction has been proposed to maintain the equilibrium phase of the immunoediting process and to control tumor growth by immunological cancer dormancy. We recently reported a model of immunological breast cancer dormancy based on the murine 4T1 TNBC model. Treatment of 4T1 cells in vitro with high-dose chemotherapy activated the type I interferon (type I IFN) signaling pathway, causing a switch from immunosuppressive to cytotoxic T lymphocyte-dependent immune response in vivo, resulting in sustained dormancy. Here, we developed a deterministic mathematical model based on the assumption that two cell subpopulations exist within the treated tumor: one population with high type I IFN signaling and immunogenicity and lower growth rate; the other population with low type I IFN signaling and immunogenicity and higher growth rate. The model reproduced cancer dormancy, elimination, and immune-escape in agreement with our previously reported experimental data. It predicted that the injection of dormant tumor cells with active type I IFN signaling results in complete growth control of the aggressive parental cancer cells injected at a later time point, but also of an already established aggressive tumor. Taken together, our results indicate that a dormant cell population can suppress the growth of an aggressive counterpart by eliciting a cytotoxic T lymphocyte-dependent immune response

Micro helical polymeric structures produced by variable voltage direct electrospinning

Direct near field electrospinning is used to produce very long helical polystyrene microfibers in water. The pitch length of helices can be controlled by changing the applied voltage, allowing to produce both micro springs and microchannels. Using a novel high frequency variable voltage electrospinning method we found the helix formation speed and compared the experimental buckling frequency to theoretical expressions for viscous and elastic buckling. Finally we showed that the newmethod can be used to produce new periodic micro and nano structures.Comment: accepted for publication in Soft Matte

Microspore embryogenesis: assignment of genes to embryo formation and green vs. albino plant production

Plant microspores can be reprogrammed from their normal pollen development to an embryogenic route in a process termed microspore embryogenesis or androgenesis. Stress treatment has a critical role in this process, inducing the dedifferentiation of microspores and conditioning the following androgenic response. In this study, we have used three barley doubled haploid lines with similar genetic background but different androgenic response. The Barley1 GeneChip was used for transcriptome comparison of these lines after mannitol stress treatment, allowing the identification of 213 differentially expressed genes. Most of these genes belong to the functional categories “cell rescue, defense, and virulence”; “metabolism”; “transcription”; and “transport”. These genes were grouped into clusters according to their expression profiles among lines. A principal component analysis allowed us to associate specific gene expression clusters to phenotypic variables. Genes associated with the ability of microspores to divide and form embryos were mainly involved in changes in the structure and function of membranes, efficient use of available energy sources, and cell fate. Genes related to stress response, transcription and translation regulation, and degradation of pollen-specific proteins were associated with green plant production, while expression of genes related to plastid development was associated with albino plant regeneration