Abstract In Medicine, it is critical “to offer 100% of what is needed and avoid 100% of what is not needed.” Unfortunately, this primary issue is challenging, and generally, more than required is offered, and everything that is unnecessary is not avoided. This is a nonsystematic review with a teaching objective that reviews the general issue in primary care and suggests ways to avoid overuse and shortcomings concerning preventive, diagnostic, therapeutic, and rehabilitative interventions. Knowing not to do is science and art that is hardly taught and practiced less. The overuse that harm are an almost daily part of clinical practice in prevention, diagnosis, treatment, and rehabilitation. It is essential to promote “the art and science of not doing”.

Resumen En Medicina es clave “ofrecer el 100% de lo que se precisa y evitar el 100% de lo que no se precisa”. Lamentablemente, es difícil cumplir con esta cuestión clave y generalmente se ofrece más de lo que se precisa y no se evita todo lo que no se precisa. Este texto es una revisión no sistemática con objetivo docente en que se revisa el problema general en atención primaria y se proponen formas de evitar los excesos y defectos respecto a intervenciones preventivas, diagnósticas, terapéuticas y de rehabilitación. Saber no hacer es ciencia y arte que se enseña poco y se practica menos. Los excesos que dañan son parte casi diaria de la práctica clínica, en prevención, diagnóstico, tratamiento y rehabilitación. Es imprescindible fomentar “el arte y la ciencia de no hacer”.

Abstract In Medicine, it is critical “to offer 100% of what is needed and avoid 100% of what is not needed.” Unfortunately, this primary issue is challenging, and generally, more than required is offered, and everything that is unnecessary is not avoided. This is a nonsystematic review with a teaching objective that reviews the general issue in primary care and suggests ways to avoid overuse and shortcomings concerning preventive, diagnostic, therapeutic, and rehabilitative interventions. Knowing not to do is science and art that is hardly taught and practiced less. The overuse that harm are an almost daily part of clinical practice in prevention, diagnosis, treatment, and rehabilitation. It is essential to promote “the art and science of not doing”.

Resumen En Medicina es clave “ofrecer el 100% de lo que se precisa y evitar el 100% de lo que no se precisa”. Lamentablemente, es difícil cumplir con esta cuestión clave y generalmente se ofrece más de lo que se precisa y no se evita todo lo que no se precisa. Este texto es una revisión no sistemática con objetivo docente en que se revisa el problema general en atención primaria y se proponen formas de evitar los excesos y defectos respecto a intervenciones preventivas, diagnósticas, terapéuticas y de rehabilitación. Saber no hacer es ciencia y arte que se enseña poco y se practica menos. Los excesos que dañan son parte casi diaria de la práctica clínica, en prevención, diagnóstico, tratamiento y rehabilitación. Es imprescindible fomentar “el arte y la ciencia de no hacer”.

Propolis is a resinous mixture of different plant exudates collected by honeybees. Currently, propolis is widely used as a food supplement and in folk medicine. We have evaluated 20 Cuban propolis extracts of different chemical types, brown (BCP), red and yellow (YCP), with respect to their in vitro antibacterial, antifungal and antiprotozoal properties. The extracts inhibited the growth of Staphylococcus aureus and Trichophyton rubrum at low µg/mL concentrations, whereas they were not active against Escherichia coli and Candida albicans. The major activity of the extracts was found against the protozoa Leishmania, Trypanosoma and Plasmodium, although cytotoxicity against MRC-5 cells was also observed. The BCP-3, YCP-39 and YCP-60 extracts showed the highest activity against P. falciparum, with 50% of microbial growth (IC50) values of 0.2 µg/mL. A positive correlation between the biological activity and the chemical composition was observed for YCP extracts. The most promising antimicrobial activity corresponds to YCP subtype B, which contains acetyl triterpenes as the main constituents. The present in vitro study highlights the potential of propolis against protozoa, but further research is needed to increase selectivity towards the parasite. The observed chemical composition-activity relationship of propolis can contribute to the identification of the active principles and standardisation of this bee product.

A Neospora caninum 17 kDa protein fraction (p17) has been described as an immunodominant antigen (IDA) under reducing and non-reducing conditions. The aim of the present study was to investigate the diagnostic utility of p17 in cattle. In order to achieve this, p17 was purified by electroelution from whole N. caninum tachyzoite soluble extract and a p17-based Western blot (WB-p17) was developed. The p17 recognition was measured by densitometry and expressed as OD values to check the validity of the WB-p17. A total of 131 sera including sequential samples from naturally- and experimentally-infected calves and breeding cattle were analysed by WB-p17 and compared with IFAT using whole formalin-fixed tachyzoites as a reference test. The results obtained highlight the feasibility of using the N. caninum p17 in a diagnostic test in cattle. Firstly, the assay based on the p-17 antigen discriminated between known positive and negative sera from different cattle populations, breeding cattle and calves. Secondly, the p17 antigen detected fluctuations in the antibody levels and seroconversion in naturally- and experimentally-infected cattle. Significant differences in p-17 antigen recognition were observed between naturally infected aborting and non-aborting cattle, as well as significant antibody fluctuations over time in experimentally infected cattle, which varied between groups. Furthermore, the results obtained with WB-p17 are in accordance with the results obtained with the IFAT, as high agreement values were obtained when all bovine subpopulations were included (kappa = 0.86).