Anti-proliferative and cytotoxic activity of pentadactylin isolated from <Emphasis Type="Italic">Leptodactylus labyrinthicus</Emphasis> on melanoma cells

Nowadays, the emergence of resistance to the current available chemotherapeutic drugs by cancer cells makes the development of new agents imperative. The skin secretion of amphibians is a natural rich source of antimicrobial peptides (AMP), and researchers have shown that some of these wide spectrum molecules are also toxic to cancer cells. The aim of this study was to verify a putative anticancer activity of the AMP pentadactylin isolated for the first time from the skin secretion of the frog Leptodactylus labyrinthicus and also to study its cytotoxic mechanism to the murine melanoma cell line B16F10. The results have shown that pentadactylin reduces the cell viability of B16F10 cells in a dose-dependent manner. It was also cytotoxic to normal human fibroblast cells; nevertheless, pentadactylin was more potent in the first case. The studies of action mechanism revealed that pentadactylin causes cell morphology alterations (e.g., round shape and shrinkage morphology), membrane disruption, DNA fragmentation, cell cycle arrest at the S phase, and alteration of mitochondrial membrane potential, suggesting that B16F10 cells die by apoptosis. The exact mechanism that causes reduction of cell viability and cytotoxicity after treatment with pentadactylin is still unknown. In conclusion, as cancer cells become resilient to death, it is worthwhile the discovery of new drugs such as pentadactylin that induces apoptosis.     

Preliminary testing of Anostraca from Italy for use in freshwater fish culture

Annual production of age-1 and age-2 crayfish of three populations in the New River, West Virginia, was quantified and then compared to previously reported harvest of crayfish by a bait fishery. Sampling of crayfish within circular plots and age and growth analyses aided estimation of crayfish production. Orconectes sanbornii sanbornii has a two-year life cycle, and Cambarus sciotensis and Orconectes virilis had three-year life cycles. Production by age-1 and age-2 crayfish (all species) was about 7.0 g live weight m⁻² yr⁻¹; almost half of this production was by C. sciotensis. Greater crayfish density and therefore production occurred in riffles than in pools. Annual crayfish harvest by anglers and commercial catchers was equivalent to about 5% of annual crayfish production.     

Observations on the biology of the rare Branchipus visnyai Kertesz 1956 (Crustacea, Anostraca) from Monti Reatini (Latim, central Italy)

Branchipus visnyai is presently known from only one location, in Italy, on Monte Catabio (central Appennine, Latium, 1590 m a.s.l). It lives in a large astatic pond and in a small temporary pool close to the pond. Typically two generations appear in the pond (in spring after snowmelt and in autumn after dilution by rainfall), unless an exceptionally dry season occurs. Yet, due to shallowness and small size, filling and duration of the pool is erratic and depends on the annual amount of snow and rainfall. Consequently, B. visnyai does not always appear in the pool.Field studies suggest that either a rise in temperature or a drop in conductivity may trigger cyst hatching in the two biotopes. Also, the species exhibits a high tolerance to change in environmental factors like water temperature. Hatching occurs within a range of 10–22 °C, adults survive at temperatures from 1 to 27 °C. The optimum seems to correspond to 10–20 °C.     

Decrease of rotenone inhibition is a sensitive parameter of complex I damage in brain non-synaptic mitochondria of aged rats

We investigated NADH oxidation in non-synaptic and synaptic mitochondria from brain cortex of 4- and 24-month-old rats. The NADH oxidase activity was significantly lower in non-synaptic mitochondria from aged rats; we also found a significant decrease of sensitivity of NADH oxidation to the specific Complex I inhibitor, rotenone. Since the rotenone-binding site encompasses Complex I subunits encoded by mtDNA, these results are in accordance with the mitochondrial theory of aging, whereby somatic mtDNA mutations are at the basis of cellular senescence. Accordingly, a 5 kb deletion was detected only in the cortex of the aged animals.     

Genetic differences in cystic fibrosis patients with and without pancreatic insufficiency

Summary To determine the number and frequency of mutations that occur at the cystic fibrosis locus (CF), we have examined the allele and haplotype frequencies of eight polymorphic DNA markers linked to CF in 163 Italian patients who were sub-divided according to their clinical presentations. The distribution of haplotypes for the tightly linked polymorphisms KM.19 and XV-2c differ significantly between patients with and those without pancreatic insufficiency. The haplotype found most commonly in CF chromosomes occurs much more frequently in pancreatic insufficient than in pancreatic sufficient patients. Among the 19 pancreatic sufficient patients, 6 (31.6%) show at least one copy of the rare KM.19 = 1, XV-2c = 2 haplotype, as against 16 of 138 patients (11.6%) with pancreatic insufficiency. In addition, only 5 pancreatic sufficient patients (26.3%) are homozygous for the common 2,1 haplotype, as compared with 88 patients (63.8%) with pancreatic insufficiency. These findings support the hypothesis of allelic heterogeneity at a single locus in CF and suggest that different mutations underlie the presence or absence of pancreatic insufficiency in this disorders.     

Time-related shape control modifications during erythrocyte storage with additive solutions

To obtain more detailed information on the reversibility of shape alterations in blood bank stored erythrocytes, we have studied shape recovery after chemical crenation and rheological properties in 8 PAGGS-sorbitol preserved erythrocyte concentrates during a five week storage period under blood bank conditions. Our results show that red cell capability to regain a normal discoid shape after chemical crenation decreases during storage but is not lost over a five week period. Moreover there is a significant but weak correlation between red cell ATP content and both shape recovery capability and viscosity. Our results confirm suspicious that red cell shape perturbations following blood bank storage are widely reversible. Two different mechanisms may be involved in reducing shape recovery capability during storage, namely an ATP-dependent mechanism and an energy-independent one. The energy dependent mechanism may be preserved by the previous addition of solutions which maintain higher energy levels during storage.