PARTITION OF THE ORGANOCHLORINE INSECTICIDE LINDANE INTO THE HUMAN SPERM SURFACE INDUCES MEMBRANE DEPOLARIZATION AND CALCIUM INFLUX

The effects of the insecticide lindane (the gamma-isomer of 1,2,3,4,5,6-hexachlorocyclohexane) on membrane potential, cytosolic free Ca2+ concentration ([Ca2+]i) and surface biophysical properties were studied in human spermatozoa. The insecticide induces rapid, transient and reproducible membrane depolarization and opening of voltage-dependent Ca2+ channels leading to an increase in [Ca2+]i. In contrast with the effect in somatic cells, lindane did not affect gamma-aminobutyric acid receptor-linked Cl- currents. Ca2+ and K+ currents were found to drive lindane-induced membrane depolarization and repolarization respectively, whereas Na+ and Cl- fluxes appear not to have a role in the phenomenon. The insecticide was still able to produce membrane depolarization both in the combined absence of extracellular Ca2+ and Na+ and in high-K+ buffer, suggesting that lindane alters the membrane dipole potential. In agreement with this, Laurodan and Prodan fluorescence spectroscopy revealed that lindane partition into the sperm plasma membrane lowers water molecular dynamics in the uppermost region of the membrane external leaflet, probably as the result of reordering of water dipoles. We propose that the first effect of lindane partitioning into the sperm plasma membrane is a change in the membrane dipole potential, which results in the activation of membrane-located Ca2+-influx pathways

Culture conditions influence satellite cell activation and survival of single myofibers

Single myofiber isolation protocols allow to obtain an in vitro system in which the physical association between the myofiber and its stem cells, the satellite cells, is adequately preserved. This technique is an indispensable tool by which the muscle regeneration process can be recapitulated and studied in each specific phase, from satellite cell activation to proliferation, from differentiation to fusion. This study aims to clarify the effect of different culture conditions on single myofibers, their associated satellite cells, and the physiological behavior of the satellite cells upon long term culture. By direct observations of the cultures, we compared different experimental conditions and their effect on both satellite cell behavior and myofiber viability

Ultra-weak photon emission from the seed coat in response to temperature and humidity - a potential mechanism for environmental signal transduction in the soil seed bank

Seeds beneath the soil sense the changing environment to time germination and seedling emergence with the optimum time of year for survival. Environmental signals first impact with the seed at the seed coat. To investigate whether the seed coat has a role in environmental sensing we investigated their ultra-weak photon emission (UPE) under the variable temperature, relative humidity and oxygen conditions they could experience in the soil seed bank. Using a custom built luminometer we measured UPE intensity and spectra (300-700 nm) from Phaseolus vulgaris seeds, seed coats and cotyledons. UPE was greatest from the internal surface of the seed coat. Seed coat UPE increased concomitantly with both increasing temperature and decreasing relative humidity. Emission was oxygen dependent and it was abolished by treatment with dinitrophenylhydrazine demonstrating the key role of seed coat carbonyls in the phenomenon. We hypothesize that beneath the soil surface the attenuation of light (virtual darkness: low background noise) enables seeds to exploit UPE for transducing key environmental variables in the soil (temperature, humidity and oxygen) to inform them of seasonal and local temperature patterns. Overall, seed coats were found to have potential as effective transducers of key fluctuating environmental variables in the soil

Content, mineral allocation and leaching behavior of heavy metals in urban PM2.5

This work provides a novel perspective in the field of urban airborne particle investigation that is not currently found in the literature. Four sampling campaigns were performed in the urban area of Rome (Central Italy) during the winter and summer seasons (February and July 2013 and 2014, respectively). The measured concentrations of the regulated 34 elements of As, Cd, Ni and Pb were consistent with those reported by the local Environmental Agency (ARPA Lazio), but non-regulated heavy metals, including Fe, Cu, Cr and Zn, were also found in PM2.5 and analyzed in detail. As an novelty, heavy metals were associated with the host-identified mineral phases, primarily oxides and alloys, and to a lesser extent, other minerals, such as sulfates, carbonates and silicates. Leaching tests of the collected samples were conducted in a buffered solution mimicking the bodily physiological environment. Despite the highest concentration of heavy metals found during the winter sampling period, all of the elements showed a leaching trend leading to major mobility during the summer period. To explain this result, an interesting comparative analysis between the leaching test behavior and innovative mineral allocation was conducted. Both the heavy metal content and mineral allocation in PM2.5 might contribute to the bioavailability of toxic elements in the pulmonary environment. Hence, for regulatory purposes, the non-linear dependency of heavy metal bioavailability on the total metal content should be taken into account

Metodo e kit diagnostico per la valutazione citologica dello stato dell'acrosoma degli spermatozoi

Metodo per la valutazione citologica dello stato acrosomiale negli spermatozoi umani, includente: 1) una prima fase in cui una sospensione di spermatozoi in tampone salino isotonico a pH fisiolo-gico, viene fatta reagire con una soluzione reagente di un tampone salino isotonico di pH fisiologi-co includente a sua volta un composto detergente non ionico presente in una concentrazione com-presa tra 30 e 70 μM; un composto polianionico che in opportune concentrazioni è in grado di ri-muovere almeno parzialmente le proteine nucleari dalla superficie del DNA attraverso la competi-zione per le interazioni elettrostatiche tra DNA e le proteine nucleari; e un composto riducente in grado di clivare e/o prevenire la formazione di legami di solfuro e presente in una concentrazione compresa tra 30 e 100 mM. 2) una seconda fase in cui alla soluzione proveniente dalla reazione della detta prima fase viene aggiunto un composto fissativo per citologia in grado di arrestare la reazione nella detta prima fa-se. 3) una terza fase in cui gli spermatozoi provenienti dalla seconda fase vengono osservati per la valutazione dello stato di integrità dell'acrosoma

S.O.S. Fertilità

Nuovi tipi di inquinamento stanno alterando i meccanismi della riproduzione e della fertilità maschile. Quali sono, dove sono, come agiscono, come proteggersi