MESENCHYME CELLS IN STARFISH DEVELOPMENT: EFFECT OF TUNICAMYCIN ON THEIR DIFFERENTIATION, MIGRATION AND FUNCTION

The effect of tunicamycin, an inhibitor of protein glycosylation, on starfish development was investigated. Specific developmental events such as 1) bulging of the archenteron tip, 2) migration of mesenchyme cells, 3) formation of coelomic pouches and 4) mouth formation, are inhibited in the presence of this drug. These events are discussed in connection with differentiation, migration and function of mesenchyme cells. The possibility is discussed that tunicamycin exerts its effect by interfering with de novo synthesis of a cell surface factor(s) supporting dynamic cell surface activities.     

Terrestrial carbon stocks across a gradient of urbanization: a study of the Seattle,WA region

Most of our global population and its CO₂ emissions can be attributed to urban areas. The process of urbanization changes terrestrial carbon stocks and fluxes, which, in turn, impact ecosystem functions and atmospheric CO₂ concentrations. Using the Seattle, WA, region as a case study, this paper explores the relationships between aboveground carbon stocks and land cover within an urbanizing area. The major objectives were to estimate aboveground live and dead terrestrial carbon stocks across multiple land cover classes and quantify the relationships between urban cover and vegetation across a gradient of urbanization. We established 154 sample plots in the Seattle region to assess carbon stocks as a function of distance from the urban core and land cover [urban (heavy, medium, and low), mixed forest, and conifer forest land covers]. The mean (and 95% CI) aboveground live biomass for the region was 89±22 Mg C ha^?1 with an additional 11.8±4 Mg C ha^?1 of coarse woody debris biomass. The average live biomass stored within forested and urban land covers was 140±40 and 18±14 Mg C ha^?1, respectively, with a 57% mean vegetated canopy cover regionally. Both the total carbon stocks and mean vegetated canopy cover were surprisingly high, even within the heavily urbanized areas, well exceeding observations within other urbanizing areas and the average US forested carbon stocks. As urban land covers and populations continue to rapidly increase across the globe, these results highlight the importance of considering vegetation in urbanizing areas within the terrestrial carbon cycle.     

TASTE PERCEPTION OF UMAMI-RICH DISHES IN ITALIAN CULINARY TRADITION

The aim of this research project was to investigate umami taste properties of recipes based on Italian culinary tradition and prepared with umami-rich ingredients, focusing on the impact of the preparation and ingredient combination. Gustative profiles were prepared for a traditional Italian dish, tender beef bouillon, usually consumed with pasta stuffed with beef. Four different samples were designed by changing the ingredients (with or without integrating Parmigiano cheese) and the preparation (cooking time) of the recipe. Panelists were rigorously trained for umami taste evaluation using monosodium L-glutamate (MSG) aqueous solutions and were then asked to evaluate umami sensation in tender beef bouillon with or without added Parmigiano Reggiano . A majority of the panelists were able to distinguish correctly umami sensations induced by MSG. The level of umami enhancement induced by Parmigiano Reggiano was clearly perceived by the panelists, and this enhancement positively affected also other basic tastes; whereas the cooking time had no clear effect on the gustative perception.

PRACTICAL APPLICATIONS

In western countries, people do not know much about umami. This taste is defined as the "savoriness" of the glutamate. Umami-taste substances are present in several foods, but whereas the taste of monosodium glutamate and 5' nucleotides can be without difficulty identified in water solutions, which are usually employed for panel training, the ability to identify this primary taste decreases enormously in more complex matrices like food. This study describes a procedure for screening and training sensory panels and could serve as a guide in teaching panelists to recognize and quantify the umami taste in a multistimuli matrix like a food recipe or product.
It also provides a practical application in a recipe in which the umami taste is modulated by the culinary preparation and ingredients.     

The Amphibian Kupffer Cells Build and Demolish Melanosomes: An Ultrastructural Point of View

This ultrastructural research was carried out to investigate the nature of the liver pigment cells of anuran and caudate amphibians, the pattern of melanosome ontogenesis, and the demolition processes of old melanosomes. We demonstrate that these liver pigment cells are able to internalize zymosan particles and latex beads; therefore, being professional phagocytes, they, as liver resident macrophages, can be classified as Kupffer cells (KCs). They show “melanosomogenesis centers” in which several maturation stages of premelanosomes are visible; the premelanosomes are formed by two principal components: a filamentous structure that will constitute the “inner” area of the melanosome and a vesicular component, budding from the Trans Golgi Network and that carries enzymes, which will constitute the “cortical area” of the melanosome. Thus the KCs, thanks to the presence of the “melanosomogenesis centers,” are also melanosome producing cells. They are also able to demolish melanosomes by heterophagocytosis and, probably, also by autophagocytosis. In conclusion, we propose a classification of vertebrate pigment cells.     

Melanins in Physiological Conditions Protect Against Lipoperoxidation. A Study on Albino and Pigmented Xenopus

The susceptibility to lipoperoxidation in liver of albino and pigmented Xenopus laevis Daudin, has been studied. Albino Xenopus liver was richer in polyunsaturated fatty acids (PUFAs) than the pigmented one; moreover, it was also richer in mitochondrial superoxide dismutase (MnSOD) and in reduced glutathione (GSH). The thiobarbituric acid-reactive substances (TBARS) values were more abundant in the albino tissue compared to the pigmented tissue both during spontaneous and Fe⁺⁺ induced lipoperoxidation. Therefore, when isolated and purified melanin, in physiological quantities, was added to albino tissue, the TBARS values drastically decreased. Thus, melanin, in our experimental conditions, protects the albino tissue even more than SOD and GSH do. Melanin, in our opinion, acts as an antioxidant, because it is able to scavenge O₂^?.     

RAPID SYNCYTIUM FORMATION BETWEEN HUMAN T-CELL LEUKAEMIA VIRUS TYPE-I (HTLV-I)-INFECTED T-CELLS AND HUMAN NERVOUS SYSTEM CELLS: A POSSIBLE IMPLICATION FOR TROPICAL SPASTIC PARAPARESIS/HTLV-I ASSOCIATED MYELOPATHY

Tropical spastic paraparesis/HTLV-I associated myelopathy (TSP/HAM), is characterized by infiltration of human T cell leukaemia virus type-I (HTLV-I)-infected T-cells, anti-HTLV-I cytotoxic T cells and macrophages into the patients’ cerebrospinal fluid and by intrathecally formed anti-HTLV-I antibodies. This implies that the disease involves a breakdown of the blood—brain barrier. Since astrocytes play a central role in establishing this barrier, the authors investigated the hypothesis that the HTLV-I infected T cells disrupt this barrier by damaging the astrocytes. The present study revealed the HTLV-I-producing T cells conferred a severe cytopatic effect upon monolayers of astrocytoma cell line in co-cultures. Following co-cultivation, HTLV-I DNA and proteins appeared in the monolayer cells, but after reaching a peak their level gradually declined. This appearance of the viral components was proved to result from a fusion of the astrocytic cells with the virus-producing T cells, whereas their subsequent decline reflected the destruction of the resulting syncytia. This fusion could be specifically blocked by anti HTLV-I Env antibodies, indicating that it was mediated by the viral Env proteins expressed on the surface of the virus-producing cells. Similar fusion was observed between the HTLV-I-producing cells and certain other human nervous system cell lines. If such fusion of HTLV-I-infected T cells occurs also with astrocytes and other nervous system cells in TSP/HAM patients, it may account, at least partially, for the blood—brain barrier breakdown and some of the neural lesions in this syndrome.     

ISOLATION OF CYTOCHROME OXIDASE COMPLEX FROM SEA URCHIN MITOCHONDRIAL INNER MEMBRANES

Cytochrome oxidase complex has been isolated and purified from sea urchin mitochondrial inner membranes. The complex exhibited a discrete number of bands in PAGE and a 17 kDa band was recognized by an anti-human subunit IV antibody. No bands were recognized by an anti-yeast hsp60 antibody and an anti-sea urchin β ATPase subunit.     

The phenology of Onitis alexis (Coleoptera: Scarabaeidae) in the Araluen Valley: Survival in a marginal environment

The introduced African dung beetle, Onitis alexis Klug, has become established in the warmer regions of Australia. The south-eastern limit of its current distribution is Moruya, NSW, and the Araluen Valley 50 km inland. At Araluen newly emerged beetles are present in dung in late spring, summer and autumn. Egg-laying starts 1-2 weeks after emergence and continues throughout the summer and autumn, as indicated by the presence of parous females in the population and of broods under experimental pads. Eggs laid in December/January produce adults in late summer and autumn, those laid from February to April produce adults in the following spring and summer. In the laboratory, mortality of larvae is high in cold (0–16°C), wet conditions and their development is delayed in warm (25°C and 27°C), dry conditions. This delay was confirmed in the field during the summer drought of 1982-83 when predicted times of emergence (based on day-degree summation in the soil) always preceded the observed emergence time of the local population, as well as preceding the emergence of beetles developing from eggs laid at known times. Follicle resorption in adult females was related directly to increasing age and to rainfall. Dung collected from hayed-off pasture did not affect fecundity, but caused larval mortality. Adults survived the winters at Araluen in some years, and immatures survived best during dry winters, being facilitated in this by a cold-induced larval diapause. Onitis alexis larvae can survive wet or dry summers, and cold dry winters (down to about 0°C) but not wet winters. This seems to be the major factor limiting the southern distribution of the species.