The antimicrobial sensitivity of Streptococcus mutans to nanoparticles of silver, zinc oxide, and gold.

Dental caries is a worldwide public health problem for which Streptococcus mutans has been identified as the possible infectious etiology. In recent years nanotechnology has permitted the development of new properties of materials. The objective of this study was to compare the bactericidal and bacteriostatic effects of nanoparticles of silver, zinc oxide, and gold on S. mutans. We used the liquid dilution method to find the minimum inhibitory concentrations (MICs) and with subcultures obtained the minimum bactericidal concentrations (MBCs). For silver the results showed an average MIC of 4.86 +/- 2.71 microg/mL and MBC of 6.25 microg/mL; for zinc the MIC was 500 +/- 306.18 muicrog/mL and MBC of 500 microg/mL; the gold nanoparticles demonstrated an effect only at an initial concentration of 197 mug/mL. We established a higher antimicrobial effect against S. mutans of silver nanoparticles at lower concentrations than gold or zinc, which would allow achieving important clinical effects with a reduced toxicity.

[Evaluation of changes in the treatment of spontaneous intracerebral haemorrhage in a regional hospital in Mexico]. / Evaluacion de cambios en el tratamiento de la hemorragia intracerebral espontanea en un hospital regional mexicano.

INTRODUCTION: The spontaneous intracerebral hemorrhage (ICH) shows a high lethal rate. In 1999 appeared the first therapeutic guidelines, after that new therapies have been assessed without substantial success. AIM: To describe treatment changes for ICH in a regional Mexican hospital and to assess their impact on clinical evolution. PATIENTS AND METHODS: We accomplished a retrospective study of patients admitted between 2000 and 2006. We included those elder than 15 years with tomographyc diagnostic of ICH. Patients with head injury four weeks before or undetermined initial National Institute of Health Stroke Scale (NIHSS) were excluded. Epidemiological, clinical characteristics and kind of therapy were studied. RESULTS: We analyzed 175 patients with mean age of 62 years. Etiology and localization more frequently were arterial hypertension and lobar, respectively. More than 20% were intubated and approximately one half of these admitted in intensive care unit. Angiotensin converter enzyme inhibitors were the medicaments more usually used for controlling blood pressure. An initial NIHSS > 15 or Glasgow < 9 were associated to poor outcome. Additional administration of calcium antagonist, statins and surgical decompression was associated to a better outcome. CONCLUSIONS: Use of intensive care units is a measure highly suggested as standard for ICH-therapy. In our center it was not regularly accomplished because of infrastructural deficiencies. This problem could be generated in other Mexican hospitals; attention to that phenomenon is urgently required. Evaluation of new therapeutic strategies is required.