A Divalent PAMAM-Based Matrix Metalloproteinase/Carbonic Anhydrase Inhibitor for the Treatment of Dry Eye Syndrome.

Synthetic sulfonamide derivatives are a class of potent matrix metalloproteinase inhibitors (MMPI) that have potential for the treatment of diseases related to uncontrolled expression of these enzymes. The lack of selectivity of the large majority of such inhibitors, leading to the inhibition of MMPs in tissues other than the targeted one, has dramatically reduced the therapeutic interest in MMPIs. The recent development of efficient drug delivery systems that allow the transportation of a selected drug to its site of action has opened the way to new perspectives in the use of MMPIs. Here, a PAMAM-based divalent dendron with two sulfonamidic residues was synthesized. This nanomolar inhibitor binds to the catalytic domain of two MMPs as well as to the transmembrane human carbonic anhydrases (hCAs) XII, which is present in the eye and considered an antiglaucoma target. In the animal model of an experimental dry eye, no occurrence of dotted staining in eyes treated with our inhibitor was observed, indicating no symptoms of corneal desiccation.

A spectroscopic study of the reaction of NAMI, a novel ruthenium(III)anti-neoplastic complex, with bovine serum albumin.

The reaction of Na[transRuCl4Me2SO(Im)] (NAMI; where Im is imidazole), a novel anti-neoplastic ruthenium(III) complex, with BSA, was studied in detail by various physico-chemical techniques. It is shown that NAMI, following chloride hydrolysis, binds bovine serum albumin tightly; spectrophotometric and atomic absorption data point out that up to five ruthenium ions are bound per albumin molecule when BSA is incubated for 24 h with an eightfold excess of NAMI. CD and electronic absorption results show that the various ruthenium centers bound to albumin exhibit well distinct spectroscopic features. The first ruthenium equivalent produces a characteristic positive CD band at 415 nm whereas the following NAMI equivalents produce less specific and less marked spectral effects. At high NAMI/BSA molar ratios a broad negative CD band develops at 590 nm. Evidence is provided that the bound ruthenium centers remain in the oxidation state +3. By analogy with the case of transferrins it is proposed that the BSA-bound ruthenium ions are ligated to surface histidines of the protein; results from chemical modification experiments with diethylpyrocarbonate seem to favor this view. Spectral patterns similar to those shown by NAMI are observed when BSA is reacted with two strictly related ruthenium(III) complexes Na[transRuCl4(Me2SO)2] and H(Im)[transRuCl4(Im)2] (ICR), implying a similar mechanism of interaction in all cases. It is suggested that the described NAMI-BSA adducts may form in vivo and may be relevant for the biological properties of this complex; alternatively NAMI/BSA adducts may be tested as specific carriers of the ruthenium complex to cancer cells. Implications of these findings for the mechanism of action of NAMI and of related ruthenium(III) complexes are discussed.

A simple method to eliminate mycoplasma from cell cultures.

The efficacy of several antibiotic treatments to eliminate mycoplasma from Vero cells contaminated chronically with Mycoplasma orale II were tested. Minocyclin, Kanamycin, Tylosine and Roxitromycin, at non cytotoxic concentrations, were assayed alone or in different combinations. Mycoplasma contamination was effectively eradicated without recurrence once the following regimen was applied: Incubation of contaminated cells with Tylosine (250 micrograms/ml) for 12 days followed by incubation with Minocycline (5 micrograms/ml) for 10 days. This treatment was not deleterious for cell growth, it was effective after only one application and it was successful to eradicate mycoplasma from other contaminated eukaryotic continuous cell lines.

Characteristics of an inulinase produced by Bacillus subtilis 430A, a strain isolated from the rhizosphere of Vernonia herbacea (Vell Rusby).

Bacillus subtilis 430A, isolated from the Vernonia herbacea (Vell Rusby) rhizosphere, produced an exocellular inulinase that fits the requirements for the production of syrups on an industrial scale. The partially purified enzyme, obtained by acetone precipitation, displayed a higher specificity for inulin (Km, 8 mM) than for sucrose (56 mM) and a total invertase/total inulase ratio of 0.62. In addition, it is stable at an optimal temperature of 45 to 50 degrees C for at least 7 h and is inhibited by the end product, fructose, at 14 mM.