The use of ablative lasers in the treatment of facial melasma

Melasma represents a pigmentary disorder that is difficult to treat. This study aims to broadly review the use of ablative lasers (Er:YAG and CO2) in the treatment of melasma, presenting the level of evidence of studies published to date. A total of 75 patients were enrolled in four case series studies (n=39), one controlled clinical trial (n=6) and one randomized controlled clinical trial (n=30). Studies on the Er:YAG laser showed better results with the use of short square-shaped pulses, which determined low rates of post-inflammatory hyperpigmentation and long-lasting maintenance of results. Likewise, studies on the CO2 laser proved the benefits of short pulse duration along with low-density energy. Post-treatment maintenance with the use of antipigmenting creams was necessary and effective to sustain long-term results. Ablative lasers may represent another useful and effective tool against melasma. Postinflammatory hyperpigmentation and difficulty in sustaining long-term results still represent the main limitations to a broader use of ablative lasers. Based on actual evidence, the use of this technology should be restricted to patients with recalcitrant disease. Further studies will help establish optimal laser parameters and treatment regimens.     

Acquisition of the mcr-1 gene by a high-risk clone of KPC-2-producing Klebsiella pneumoniae ST437/CC258, Brazil

We identified one clinical isolate of K. pneumoniae harboring the mcr 1 (plasmid of IncX4 family) and bla_KPC-2 (plasmid of IncFIB family) genes in southern Brazil. These findings highlight that K. pneumoniae isolates carrying both mcr-1 and bla_KPC-2 may emergence as a serious threat to antimicrobial therapy.     

Incidence of Trypanosoma cruzi transmission through breastfeeding during acute experimental Chagas disease

ObjectiveTo verify the incidence of T. cruzi transmission through breastfeeding during acute experimental Chagas’ disease.MethodsFifteen female Swiss mice were mated and, after pregnancy confirmation, placed in individual cages. A few hours after birth, the females were inoculated with 0.1 mL of blood containing approximately 3 × 10⁵ trypomastigote forms of Y strain of T. cruzi and continued breastfeeding for 25 days.ResultsIn 142 offspring examined no infection through breastfeeding was observed.ConclusionsThe low number of trypomastigote forms ingested by the newborn mice combined with biological and biochemical characteristics of blood trypomastigotes may explain the lack of transmission in this experiment.