The evolution of taste and perinatal programming of taste preferences.

Taste is important for food intake. The fetus first experiences taste through amniotic fluid, and later via mother's milk. Early human experience with taste has a key importance for later acceptance of food. Dietary behavior is determined by the interaction of many different factors. The development of the olfactory and taste receptors begins at 7-8 weeks of gestation. An early sensitive period probably exists when flavor preference is established. Sweet taste is preferred in early childhood; this is the reason why children are at increased risk of over-consuming saccharides. Gustatory sensitivity declines with age. The threshold for the perception of each basic taste differs, and is established genetically. In this review, we summarize published data on taste preferences and its development and changes during life.

The influence of galvanic currents and voltage on the proliferation activity of lymphocytes and expression of cell surface molecules.

Release of metal ions from dental metal fillings supported by galvanism can cause local or general pathological problems in sensitive and genetically susceptible individuals. We aimed to investigate in vitro lymphocyte responses and expression of surface molecules influenced by galvanic currents and voltage. Human peripheral blood lymphocytes were influenced by galvanic currents and voltages and lymphocyte proliferation was measured. Control samples were not exposed to the influence of galvanism. We also studied the expression of surface molecules by the FACS analysis. A 15-h and shorter influence of almost all tested currents and voltages caused a significant decrease in lymphocyte proliferation and the 15-h influence of 20 microA currents significantly increased expression of surface molecules CD 19, 11a/18, 19/69 and 19/95. An influence of 10 and 3 microA currents led to a significant decrease in the expression of surface molecules CD 3, 11a/18, 3/69 and 3/95 and to a significant increase in CD 19 expression. An 80 mV voltage influence led to a significant decrease in the expression of surface molecules CD 3, 11a/18, 3/69, 3/95, 19/69 and 19/95, and 200 and 300 mV voltages significantly decreased the expression of surface molecules CD 3, 19, 11a/18, 3/95 and 19/95 and significantly increased CD 19/69 expression. A long-lasting influence of galvanism can, in sensitive and genetically susceptible individuals, influence lymphocyte proliferation and surface molecule expression. The threshold for pathological values of 5 microA for galvanic currents and 100 mV for galvanic voltage was confirmed.

[Effect of heavy metals on immune reactions in patients with infertility]. / Vliv tezkých kovu na imunitní reakci u pacientu s prokázanou neplodností.

BACKGROUND: Heavy metals can negatively influence reproduction because in sensitive persons they are able to alter the immune reactions including autoantibodies production. The altered immune reaction can then cause infertility. METHODS AND RESULTS: The in vitro lymphocyte reaction after stimulation with metals, the production of interferon (IFN-gamma) and antisperm antibodies in supernatants after lymphocyte stimulation in patients with infertility and with the antisperm antibodies present in their serum were investigated. The cause of antisperm antibodies presence was not determined. The diagnosis of metal intolerance was performed by the proliferation method modified for metals (Melisa). In supernatants of tissue cultures of lymphocytes without the antigen stimulation and after stimulation with mercury chloride, the in vitro production of gamma interferon and antisperm antibodies was studied by Elisa. More than 50% of patients did not tolerate mercury, iron, aluminium and silver. When the lymphocyte reaction was compared in patients with and without mercury intolerance we found that lymphocytes of patients with mercury intolerance produced less gamma interferon and more antisperm antibodies in supernatants after mercury stimulation of lymphocytes. CONCLUSIONS: In patients with metal intolerance diagnosed by the Melisa test, metal ions released from the dental materials can represent a factor, that does not cause infertility but is able to influence it negatively.

[Sperm antibodies and immunologic intolerance to metals in infertile couples]. / Protilátky proti spermiím a imunologická intolerance nekterých kovu u neplodných páru.

OBJECTIVE: Verification of the hypothesis of a relationship between the presence of antibodies against sperm cells and immunological reactivity to some metals in infertile couples by the MELISA test. SETTING: Department of Obstetrics and Gynecology, Medical Faculty, Charles University and Faculty Hospital, Plzen. METHOD: From 23 female patients and 21 men (a total of 44 subjects treated for infertility) with confirmed serum antibodies against sperm cells the authors isolated lymphocytyes from the peripheral blood stream, divided them into individual cultures and investigated them by the MELISA test using different metal compounds. RESULTS: The outcome of the MELISA test are values of the stimulation index (SI) by means of which the authors investigated the reactivity of the organism to the given metal. Special attention was devoted to compounds of organic and inorganic mercury. The SI values were subsequently compared with different data obtained from a detailed anamnestic questionnaire which was focused specially on contact with metals and on allergic reactions. In the investigated group of patients the authors detected a positive immune reactivity to inorganic mercury, Ag, Al, Fe. In some subjects they found a very high positive immune reactivity to inorganic mercury, Ni, Al, Cd and Ti. The control groups were formed by healthy fertile subjects without antibodies against sperm cells and with physiological SI values. CONCLUSION: The authors did not prove a direct relationship between the intensity of the laboratory reactivity to metals and the presence of antibodies against sperm cells which cause deterioration of fertility. An exogenous load of metals could in case of genetic predisposition be only one of the factors which participate in the formation of antibodies against sperm cells. The investigation proved that its is not essential, contrary to the view of many stomatologists, to eliminate metal compounds completely from dental practice.

Estimation of width of narrow molecular-weight distributions by size-exclusion chromatography with concentration and light scattering detection.

A new method for the estimation of the weight-to-number-average molecular-weight ratio, Mw/Mn of polymers with a narrow molecular-weight distribution, approximated by log-normal distribution, is proposed using size-exclusion chromatography (SEC) with concentration and light-scattering detectors. From experimental data, the Mw/Mn ratios are calculated by two procedures: one using the concentration and light-scattering elution curve for the polymer measured, and the other based on the concentration elution curve and calibration line for a wide range of molecular masses. An iteration method has been developed making the two Mw/Mn ratios converge. The method was applied to a series of narrow molecular-weight distribution polystyrene standards.