Effects of HeNe laser irradiation on experimental paracoccidioidomycotic lesions

Paracoccidioidomycosis (PCM) is the most prevalent human mycosis in Latin America. The infection is thought to take place firstly in the lungs and then may disseminate to other organs and tissues. Treatment by currently available antifungals is lengthy, the drugs may have undesirable side effects, and some are costly. Occasional resistant strains of Paracoccidioides brasiliensis, the causative agent of PCM, have been reported. So, the search for more efficient treatments or adjuvant therapies has to be continued. In this work, we evaluated the effects of HeNe laser irradiation on cutaneous inflammatory lesions caused by the inoculation of 5 x 10(6)/0.1ml yeasts cells into the back footpad of Balb/c mice. HeNe irradiation (lambda=632.8nm, 3mW, incident energy of 3J/cm(2)) was applied at days 7, 8 and 9 post-infection and histological and immunohistochemical analysis were done. Unirradiated animals were used as controls. The results showed that laser-treated mice presented reduction of footpad edema, faster cutaneous wound healing, confluent granuloma, diffuse- and more loosely distributed immunolabeling for TNF-alpha, enhanced labeling of IFN-gamma and any P. brasiliensis form detected, whereas multiple viable fungi were seen in diffuse widespread granulomas obtained from non-treated mice foot-pad. Fungi that were harvested from laser-treated animals presented no capability of growth in vitro as compared to those obtained from non-treated mice. We conclude that HeNe laser irradiation was able to inhibit the progress of inflammatory local reaction produced by P. brasiliensis infection and influence local cytokines production. We suggest that this treatment modality can be a useful coadjuvant tool to be combined with antifungal agents in the treatment of PCM ulcerations. The mechanisms involved in laser therapy of PCM lesions need further investigation.     

Bis(2,4,6-triisopropylphenyl)tin(IV) compounds: Synthesis, single-crystal X-ray characterization and reactivity toward ionizing species and polar monomers

The synthesis of new organotin compounds of general formula Tip₂SnRR′ (Tip = 2,4,6-triisopropylbenzene; R = R′ = CH₃ (1); R = R′ = CHCH₂ (2); R = CH₂Ph, R′ = Br (3); R = R′ = CH₂CHCH₂ (4)) is described herein. The compounds have been characterized by ¹H, ¹³C, ¹¹⁹Sn NMR, mass spectroscopy and elemental analysis. Characterization by single-crystal X-ray diffraction analysis has been obtained for compounds 2, 3 and 4. The reactivity with ionizing agents has been studied by NMR spectroscopy. Compounds 2 and 4 underwent alkyl abstraction by [(CH₃CH₂)₃Si]⁺[B(C₆F₅)₄]⁻ affording stable cationic species (2a, 4a). For the cationic specie 4a a π-interaction of the benzyl group to the metal centre was recognized by solution NMR studies. A cationic species (3a) was generated from compound 3 using AgSbF₆ as ionizing agent. The cationic species (2a, 3a) exhibited moderate activity as initiator in the cationic polymerization of 1,4-butadiene and good activity in the ring opening polymerization (ROP) of propylene oxide and ε-caprolactone.     

Saddle points for vector valued functions: existence, necessary and sufficient theorems

Necessary and sufficient conditions for a point to be a weak saddle point of a vector valued function (i.e. to be a solution of the vector saddle point problem) are given. Also, an existence result for a vector saddle point to have a solution is given.     

Corrosion behaviour of zinc coated with composite silica layers incorporating poly(amidoamine)-modified graphene oxide

Journal of Solid State Electrochemistry - The aim of the paper is to carry out a detailed investigation of the effect of graphene oxide-poly(amidoamine) (GO-PAMAM) incorporated in silica matrices...