Effects of anti-oxidizing vitamins on in vitro cultured porcine neonatal pancreatic islet cells.

Oxidative stress may cause severe cellular damage to both allo- and xeno-transplanted islets, additional to islet graft-directed immunity, in diabetic patients. We thus aimed to examine the effects of antioxidants on in vitro culture-maintained, neonatal porcine cell clusters (NPCCs). NPCCs were treated with antioxidants (vitamins D3 and E) by a certain time of their maturation and differentiation process. Insulin recovery showed that both vitamins D3 and E, unlike untreated controls, resulted in preservation of the islet function for significantly long periods of time. Such effects were also confirmed during NPCCs in vitro static incubation with high glucose. Furthermore, morphologic examination of NPCCs demonstrated that at 16 days of cell culture beta-cell clusters were significantly larger and more intact when exposed to the vitamins as compared to controls. According to these preliminary results, because the employed vitamins, known to retain anti-oxidizing properties, seemed to clearly improve NPCCs morphology and function, they may represent a potentially useful tool for islet culture maintenance in the pre-transplant time period.

[Comparative study and time changes in the resistance to gentamycin, tobramycin, sisomicin and amikacin of Gram-negative nosocomial bacterial strains isolated from the urinary tract, in relation to the annual use of the aminoglycosides tested]. / Studio comparativo e variazioni nel tempo delle resistenze a gentamicina, tobramicina, sisomicina ed amikacina di ceppi batterici nosocomiali Gram-negativi isolati dalle vie urinarie, in relazione ai consumi ospedalieri annuali degli aminoglucosidi esaminati.

Changes in susceptibility to four aminoglycosides (gentamycin, amikacin, tobramycin, sisomicin) of bacterial strains, isolated from in-patients with urinary tract infections at the "Santa Maria della Scala" Hospital of Siena, in the period January-April in three consecutive years (1980, 1981, 1982) were studied. The change susceptibility patterns were related to the use of the four antimicrobial drugs in the same periods. Emergence of antibiotic-resistant strains was seen after a wider use, whereas an increasing number of susceptible strains was observed after reducing use of antimicrobial drugs.