Learning during sleep?

Studies on the sleep-learning phenomenon are criticized in terms of weaknesses in experimental design, statistics and methodology employed, and criteria of sleep. While it is highly speculative that the studies reviewed show that sleep-learning is possible, "The conditions under which the results were found tend more to support the contention that some learning takes place in a special kind of waking state wherein Ss apparently do not remember later on if they had been awake. This may be of great practical importance from the standpoint of economy in study time, but it cannot be construed as sleep-learning." 25 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prediction of Temperature Profiles in Tumors and Surrounding Normal Tissues During Magnetic Induction Heating

The development and preliminary verification of a simple two-compartment model describing the thermal response of adjacent normal and cancerous tissues subjected to magnetic induction heating is presented. Analytical expressions were found for estimating the spatial temperature distributions in the system composed of a spherical tumor mass imbedded in a cylindrical normal tissue as a function of the field intensity and the tissue's physical, geometrical, and physiological characteristics. The conditions leading to preferential heating of the tumor are described.     

Effect of 2 types of diet changes on dietary habits, body weight and cholesterol levels in high risk cardiovascular patients

Several non-pharmacological interventions such as weight reduction in obese subjects or diet alteration in subjects having hypercholesterolemia have been shown to be effective in therapeutic trials. Our aim was to test the value of two different ways of teaching patients about their diet. From March 1, 1993, to May 30, 1994, 300 consecutive patients seen in a one-day care hospital were randomised into two groups. The 2 inclusion criteria were: 1) body mass index > 27 kg/m2 in men and > to 25 kg/m2 in women and/or 2) presence of a hypercholesterolemia defined by a total cholesterol > 6.5 mmol/l. Patients in the first group (C) were educated in a 20 to 50 minutes consultation tailored to their needs. Patients in the second group (CC) were given in addition a one-hour course about diet. The goal of the diet was to loss at least 3 kg of body weight and/or to have a cholesterol value below 6.5 mmol/l without treatment. All Patients were followed-up by the same 3 dietician nurses. An out-patient visit was planned at 3 months, and a recall letter was sent to the patients who missed their appointments. Among the 300 patients, 169 (55%) were seen at the 3-month outpatient visit. This proportion did not differ between the 2 groups. Knowledge on diet was assessed by the same 33-item self-administered questionnaire. At baseline scores were comparable between groups (16 vs 17). Scores improved more in the CC than in the C group both at the end of the teaching question (27 vs 23 in the CC and C group respectively, p < 0.001), and at 3 months (25 vs 23 in the CC and C group respectively; p < 0.001). Total cholesterol decreased below 6.5 mmol/l in 28% of the patients with dyslipidemia and a weight loss > 3 kg was observed in 32% of the obese subjects, but improvement did not differ between the 2 groups. We conclude that a specific one-hour course on diet is able to improve knowledge of patients more than a consultation alone, but that better knowledge did not result in improved alteration of risk factors at 3 months.     

Why colour order systems?

In this introductory lecture to the AIC Forsius Symposium on Colour Order Systems, the author reviews color order systems from a historical point of view as samplings of the World of Colour, seeking with each example to find an answer to the question posed in the title.     

Defective acidification in human breast tumor cells and implications for chemotherapy

Multidrug resistance (MDR) is a significant problem in the treatment of cancer. Chemotherapeutic drugs distribute through the cyto- and nucleoplasm of drug-sensitive cells but are excluded from the nucleus in drug-resistant cells, concentrating in cytoplasmic organelles. Weak base chemotherapeutic drugs (e.g., anthracyclines and vinca alkaloids) should concentrate in acidic organelles. This report presents a quantification of the pH for identified compartments of the MCF-7 human breast tumor cell line and demonstrates that (a) the chemotherapeutic Adriamycin concentrates in acidified organelles of drug-resistant but not drug-sensitive cells; (b) the lysosomes and recycling endosomes are not acidified in drug-sensitive cells; (c) the cytosol of drug-sensitive cells is 0.4 pH units more acidic than the cytosol of resistant cells; and (d) disrupting the acidification of the organelles of resistant cells with monensin, bafilomycin A1, or concanamycin A is sufficient to change the Adriamycin distribution to that found in drug-sensitive cells, rendering the cell vulnerable once again to chemotherapy. These results suggest that acidification of organelles is causally related to drug resistance and is consistent with the hypothesis that sequestration of drugs in acidic organelles and subsequent extrusion from the cell through the secretory pathways contribute to chemotherapeutic resistance.     

Immunoblotting detection of autoantibodies to human epidermis filaggrin: a new diagnostic test for rheumatoid arthritis

OBJECTIVE: We previously reported that so-called antikeratin antibodies (AKA) and antiperinuclear factor (APF) recognize epitope(s) present on human epidermal filaggrin. In the present study, we developed a new diagnostic test for rheumatoid arthritis (RA) based on detection of antifilaggrin autoantibodies (AFA) by immunoblotting. METHODS: We tested 670 serum samples, including 190 RA. AFA titers were estimated by immunoblotting on filaggrin enriched human epidermis extracts, and AKA titers by indirect immunofluorescence (IIF) on rat esophagus epithelium. Diagnostic values of the tests were compared. RESULTS: Each test resulted in diagnosis of more than 40% of RA samples, with a specificity of 0.99. Although the tests were strongly correlated, their association allowed the diagnosis of more than 60% of RA samples, with the same specificity. CONCLUSION: Immunoblot detection of AFA, a simple and standardizable test, may be an alternative or complement to conventional IIF detection of AKA.     

Variation of structural and superconducting properties with initial stoichiometry variation in (Bi,Pb)-Sr-Ca-Cu-O bulk superconductor

The effect of the initial stoichiometry variation (variation in Bi, Pb, Sr, Ca and Cu) on various structural and superconducting properties of Pb-doped Bi-based superconductor has been studied. The sample having the initial stoichiometry of (Bi_1.8Pb_0.4)Sr₂Ca_2.2Cu₃O₁₀ was found to give best structural and superconducting properties. The most important factors affectingJ _c in the samples were the type of impurity phases present in the sample, their amount and distribution in the superconducting matrix. Cu-rich stoichiometry enhanced the formation of 110 K phase, but large amounts of undesirable impurities present in the samples decreasedJ _c. The formation of 110 K phase and texturing of (001) planes in a sample depended on the period of heat treatment and stoichiometry.