Biological response of HeLa cells to gold nanoparticles coated with organic molecules.

In this work, gold nanospheres functionalized with low weight organic molecules (4-aminothiphenol and cysteamine) were synthesized in a one-step method for their in vitro cytotoxic evaluation on HeLa cells. To enhance the biocompatibility of the cysteamine-capped GNPs, BSA was used due to its broad PH stability and high binding affinity to gold nanoparticles. Besides, the widely reported silica coated gold nanorods were tested here to contrast their toxic response against our nanoparticles coated with organic molecules. Our results shown, the viability measured at 1.9×10-5M did not show significant differences against negative controls for all the samples; however, the metabolic activity of HeLa cells dropped when they were exposed to silica gold nanorods in the range of concentrations from 2.9×10-7M to 3.0×10-4M, while in the cases of gold nanospheres, we found that only at concentrations below 1.9×10-5M metabolic activity was normal. Our preliminary results did not indicate any perceivable harmful toxicity to cell membrane, cytoskeleton or nucleus due to our nanospheres at 1.9×10-5M. Additional test should be conducted in order to ensure a safe use of them for biological applications, and to determine the extent of possible damage.

[Acute heart failure in patients over 70 years of age: Precipitating factors of decompensation]. / Insuficiencia cardiaca aguda en pacientes de 70 años o más: factores precipitantes de descompensación.

OBJECTIVES: Heart failure decompensation is the most common reason for hospitalization in persons over 65 years old. There is limited information on the prevalence of precipitating factors of heart failure decompensation in this population. In this study we prospectively examined the factors associated with decompensation of heart failure in patients over 70 years of age. MATERIAL AND METHODS: During the 36 months from January 2006 to December 2008, we included 386 patients over 70 years of age that were admitted through emergencies with these three criteria: Dyspnea (class III or IV of the New Yourk Heart Association), pulmonary edema and echocardiographic data of left ventricular systolic or diastolic dysfunction. RESULTS: The mean age of the patients was 82 years and 58.5% were female. Left ventricular systolic dysfunction was diagnosed in 41.2% of them. We identified one or more precipitating factors of heart failure decompensation in 89.6% of the patients. The most common were atrial tachyarrhythmia (22.3%), respiratory infection (21.2%), severe anemia (17.1%), acute renal failure (12.7%), severe hypoalbuminemia (11.4%) and acute coronary syndrome (9.1%). Fifty-two patients (13.5%) died. The variables independently associated with hospital mortality were acute renal failure, severe hypoalbuminemia, systolic blood pressure <110mmHg, white blood cell count >10.000 per mm³ and valvular heart disease. CONCLUSIONS: In most patients over 70 years of age hospitalized with acute heart failure it is possible to identify one or more precipitating factors of decompensation, some of which are independently associated with hospital mortality.

Are serum zinc and copper levels useful as acute rejection markers in heart transplantation?

We assessed the usefulness of zinc and copper serum level changes as acute rejection markers in orthotopic heart transplantation. Mean serum zinc levels occurring without rejection were 74 +/- 1.9 micrograms/dl, whereas with rejection they were 67 +/- 3.2 micrograms/dl (p = 0.056). Mean serum copper levels occurring without rejection were 109 +/- 3.9 micrograms/dl, whereas with rejection they were 116 +/- 6.4 micrograms/dl (p = 0.32). Results of our study show that changes in serum zinc and copper levels are not useful as rejection markers in heart transplantation. Levels of these trace elements can be affected by clinical situation and therapy in heart transplant patients regardless of rejection.