Synthesis and design of Ag-Fe bimetallic nanoparticles as antimicrobial synergistic combination therapies against clinically relevant pathogens.

The inappropriate use of antibiotics and the inadequate control of infections have led to the emergence of drug-resistant strains. In recent years, metallo-pharmaceutics and metallic nanoparticles have been proposed as potential alternative antimicrobials due to their broad-spectrum antimicrobial properties. Moreover, recent findings have shown that combinations of transition metal compounds can exhibit synergistic antimicrobial properties. Therefore, the synthesis and design of bimetallic nanoparticles is a field worth exploring to harness the interactions between groups of metals and organic complex structures found in different microbial targets, towards the development of more efficient combinatorial antimicrobials composed of synergistic metals. In this study, we present a green synthesis of Ag-Fe bimetallic nanoparticles using an aqueous extract from the leaves of Gardenia jasminoides. The characterization of the nanoparticles demonstrated that the synthesis methodology produces homogenously distributed core-shell Ag-Fe structures with spherical shapes and average diameter sizes of 13 nm (± 6.3 nm). The Ag-Fe bimetallic nanoparticles showed magnetic and antimicrobial properties; the latter were evaluated against six different, clinically relevant multi-drug-resistant microbial strains. The Ag-Fe bimetallic nanoparticles exhibited an antimicrobial (bactericidal) synergistic effect between the two metals composing the bimetallic nanoparticles compared to the effects of the mono-metallic nanoparticles against yeast and both Gram-positive and Gram-negative multidrug-resistant bacteria. Our results provide insight towards the design of bimetallic nanoparticles, synthesized through green chemistry methodologies, to develop synergistic combinatorial antimicrobials with possible applications in both industrial processes and the treatment of infections caused by clinically relevant drug-resistant strains.

Antibacterial Activity of combinatorial treatments composed of transition-metal/antibiotics against Mycobacterium tuberculosis.

Notwithstanding evidence that tuberculosis (TB) is declining, one of the greatest concerns to public health is the emergence and spread of multi-drug resistant strains of Mycobacterium tuberculosis (MDR-TB). MDR-TB are defined as strains which are resistant to at least isoniazid (INH) and rifampicin, the two most potent TB drugs, and their increasing incidence is a serious concern. Recently, notable efforts have been spent on research to pursue novel treatments against MDR-TB, especially on synergistic drug combinations as they have the potential to improve TB treatment. Our research group has previously reported promising synergistic antimicrobial effects between transition-metal compounds and antibiotics in Gram-negative and Gram-positive bacteria. In this work, we evaluated antimycobacterial activity of transition-metals/antibiotics combinatorial treatments against first-line drug resistant strains of Mycobacterium tuberculosis. Our data showed that INH/AgNO3 combinatorial treatment had an additive effect (bactericidal activity) in an isoniazid-resistant clinical strain of Mycobacterium tuberculosis. Moreover, in vitro evaluation of cytotoxicity induced by both, the individual tratments of AgNO3 and INH and the combinatorial treatment of INH/AgNO3 in murine RAW 264.7 macrophages and human A549 lung cells; showed no toxic effects. Together, this data suggests that the INH/AgNO3 combinatorial treatment could be used in the development of new strategies to treat resistant strains of Mycobacterium tuberculosis.

Blue Corn Tortillas: Effects on Learning and Spatial Memory in Rats.

Consumption of pigmented corn has been associated with health benefits due to its flavonoid contents (mainly anthocyanins) and antioxidant ability. Therefore, the objective of this study was to determine the effect of blue corn tortilla (BM) consumption on memory and learning ability adult rats. Eighteen adult female rats were divided into three groups and fed for 38 consecutive days with commercial food (Control group) or the commercial food plus 6 g/day of either blue corn (BM) or white corn (WM) tortillas. Memory and learning capabilities were assessed using Barnes's labyrinth at the end of the feeding period. Short-and long-term memory was improved in the BM group, showing that consumption of blue maize tortillas improves learning and memory capabilities in adult rats.

Attenuated Toxoplasma gondii ts-4 mutants engineered to express the Leishmania antigen KMP-11 elicit a specific immune response in BALB/c mice.

In order to test recombinant Toxoplasma as adjuvant and live vaccine carrier in the infectious disease model of murine experimental leishmaniasis, we engineered the attenuated, temperature-sensitive Toxoplasma gondii strain ts-4 to express the heterologous Leishmania antigen kinetoplastid membrane protein-11 (KMP-11). Transgenic ts-4 clones were obtained which express KMP-11 as cytoplasmatic protein or target it to the secretory pathway of the tachyzoites. Immunization of BALB/c mice with these stably transformed parasites elicited proliferative responses to both T. gondii antigen and recombinant KMP-11. When challenged with Leishmania major, we observed significant protection in animals that had been vaccinated with the KMP-11-expressing ts-4 mutants. The adjuvant attenuated only the onset of the Leishmania infection, but animals were ultimately not able to control the disease. Thus, our findings demonstrate that recombinant Toxoplasma has the potential to serve as an efficient vaccine carrier for cutaneous leishmaniasis. Furthermore, they establish a protective role for the antigen KMP-11 when given in such a vaccine formulation.

Diagnosis of cutaneous leishmaniasis in Colombia: the sampling site within lesions influences the sensitivity of parasitologic diagnosis.

Parasitologic confirmation of cutaneous leishmaniasis is obligatory before chemotherapy can be considered. Direct microscopic examination of scrapings taken from indurated borders of ulcers has been routinely used as primary method of diagnosis. In this report we compared the sensitivity of examination of dermal scrapings taken from the bottoms of ulcers (BDS) with that of dermal scrapings taken from indurated active margins of lesions (MDS) in a total of 115 patients. The sensitivities of the microscopic examination were 90.4 and 78.3% for BDS and MDS samples, respectively. When the PCR method was used with a group of 40 patients, we also observed a higher sensitivity when BDS samples were examined (80.8% in BDS samples versus 57.7% in MDS samples). The improvement of the diagnostic sensitivity in the BDS samples appears to be related to the higher parasite load and more easily detectable morphology of amastigotes in the centers of the ulcers. Other parasitologic diagnostic methods, such as culture and histopathologic examination of biopsies, are less sensitive (67.5 and 64.3%, respectively). Aspirate culture, however, was shown to be the most sensitive method for the diagnosis of patients with chronic ulcers. When microscopic examinations of both MDS and BDS samples are combined, the sensitivity of diagnosis may rise up to 94%. We therefore recommend this method as a primary routine procedure for diagnosis of cutaneous leishmaniasis.

The gene encoding the metacyclogenesis-associated transcript Mat-1 is conserved in the genus Leishmania and shows a tendency to form dimers upon protein expression.

The Leishmania infantum Mat-1 gene--recently described in L. major as a highly stage-specific, metacyclogenesis-associated transcript--has been cloned. The 420-bp Mat-1 coding region is conserved with respect to the L. major gene (82% sequence homology). Analysis of the predicted amino-acid sequence reveals structural motifs showing homology with the class of leucine-zipper transcription factors. Southern-blot hybridization analysis suggests that Mat-1 is a low-copy-number gene, probably consisting of two gene copies. The recombinant Mat-1 protein expressed in fusion with the Escherichia coli maltose-binding protein shows a tendency to form dimers in the presence of the leucine-rich C-terminal domain. Bacteria expressing the Mat-1 open reading frame are highly growth-attenuated and tend to delete or modify the insert, which suggests that expression of Mat-1 is toxic for the bacteria.

Molecular and antigenic characterization of the Leishmania (Viannia) panamensis kinetoplastid membrane protein-11.

The kinetoplastid membrane protein 11 (KMP-11) has been recently described in Leishmania (Leishmania) donovani as a major component of the promastigote membrane. Two oligonucleotide primers were synthesized to PCR-amplify the entire encoding region of New World Leishmania species. The Leishmania (Viannia) panamensis amplification product was clone, sequenced and the putative amino acid sequence determined. A remarkably high degree of sequence homology was observed with the corresponding molecule of L. (L) donovani and L. (L) infantum (97% and 96%, respectively). Southern blot analysis showed that the KMP-11 locus is conformed by three copies of the gene. the L. (V) panamensis ORF was subsequently clone in a high expression vector and the recombinant protein was induced and purified from Escherichia coli cultures. Immunoblot analysis showed that 80%, 77% and 100% sera from cutaneous, mucocutaneous and visceral leishmaniasis patients, respectively, recognized the recombinant KMP-11 protein. In a similar assay, 86% of asymptomatic Leishmania-infected individuals showed IgG antibodies against the rKMP-11. We proposed that KMP-11 could be used as a serologic marker for infection and disease caused by Leishmania in America.

[Massive paracentesis and administration of dextran 70 vs albumin in cirrhotic patients with tense ascites]. / Paracentesis masiva con reposición de dextran 70 vs albúmina en pacientes cirróticos con ascitis a tensión.

Some studies have demonstrated that paracentesis for large-volume extraction of ascites produces renal failure and hyponatremia, and intravenous infusion of plasma expanders can overcome this complications. We performed a survey where we compared effectiveness of dextran 70 vs albumin on prevention of adverse effects and cost differences. Two random groups were formed, 8 cirrhotic patients with tense ascites in each group. Paracentesis with extraction of more than 5 liters was performed. The group A received human albumin and group B dextran 70, both received 6 g per liter of extracted liquid. 24 hours before and 48 hours after of ascites extraction, we performed hepatic function test, blood chemistry with renin and aldosterone. Clinical results and biochemistry test were similar in both groups without statistical significance (p > 0.05). Amount of plasma expander was almost the same, but the cost in group A was $266 USD and in group B $20.8 USD. Azotemia was present in 12.5% in group A and hyponatremia in 12.5% in both groups, without symptoms. The results show that dextran 70 produces the same effect like albumin in the treatment of ascites after large-volume paracentesis with lower cost.

[The transjugular intrahepatic portosystemic stent-shunt (TIPS) in the management of portal hypertension. A preliminary report]. / Fístula portosistémica con prótesis intrahepática por vía transyugular (TIPS) en el manejo de la hipertensión porta. Communicación preliminar.

Transjugular intrahepatic portosystemic shunt-stent (TIPS) was performed in 5 patients with cirrhosis and portal hypertension. Bleeding varices occurred in 4 patients and refractory ascites in one. We used 2 Wallstents and 3 Strecker stents. Shunt patency, recurrent variceal hemorrhage and ascites were evaluated. The shunts were created from a transjugular approach between the hepatic and portal vein, with diameters of 10 mm. Portal pressure was adequately decreased in all cases. The hospital stay, following TIPS was 3 days. Complete variceal decompression was identified endoscopically in 3 patients, and partial in one. Four shunts were patent by ultrasound and color Doppler at 1 to 6 months of follow up. One patient presented encephalopathy and one died at third day after TIPS. Initial results suggest that TIPS is an effective method of portal decompression for treatment of variceal hemorrhage and refractory ascites. The main complication was encephalopathy and only one patient died.

Reaccion metabolica inmediata a las microdosis de insulina intramuscular en adultos con coma diabetico. / Immediate metabolic reaction of intramuscular insulin microdosis in adults with diabetic coma

Se describe el tratamiento del coma diabetico com microdosis de insulina de accion rapida por via intramuscular, recomendandose una buena hidratacion.La dosis de insulina se calcula segun el peso del paciente en forma independiente del grado de hiperglucemia. Este metodo fue utilizado en viente pacientes adultos en coma diabetico, obteniendose el control de su trastorno metabolico en las primeras cuatro horas de iniciado el tratamiento. El metodo fue sencillo, clinicamente eficaz y elimino las posibilidades de hipoglucemia