Development of Plasmodium falciparum protease inhibitors in the past decade (2002-2012)

New drug targets for the development of antimalarial drugs have emerged after the unveiling of the Plasmodium falciparum genome in 2002. Potential antimalarial drug targets can be broadly classified into three categories according to their function in the parasite's life cycle: (i) biosynthesis, (ii) membrane transport and signaling, and (iii) hemoglobin catabolism. The latter plays a key role, as inhibition of hemoglobin degradation impairs maturation of bloodstage malaria parasites, ultimately leading to remission or even cure of the most severe stage of the infection. Intraerythrocytic Plasmodia parasites have limited capacity to biosynthesize amino acids which are vital for their growth. Therefore, the parasites obtain those essential amino acids via degradation of host cell hemoglobin, making this a crucial process for parasite survival. Several plasmodial proteases are involved in hemoglobin catabolism, among which plasmepsins and falcipains are well-known examples. Hence, development of P. falciparum protease inhibitors is a promising approach to antimalarial chemotherapy, as highlighted by the present review which is focused on the Medicinal Chemistry research effort recorded in the past decade in this particular field.

Lesões melanocíticas em suínos abatidos para consumo

O presente estudo teve como principais objetivos conhecer a taxa de ocorrência de lesões melanocíticas (melanose, melanocitomas e melanomas) em suínos abatidos para consumo e identificar possíveis padrões de distinção e de classificação macroscópica dessas lesões. Para tal, procedeu-se à recolha de lesões melanocíticas em matadouro, durante oito meses, e à sua avaliação macroscópica e microscópica. Os resultados deste estudo demonstraram que as melanoses foram as lesões melanocíticas mais frequentemente encontradas (74,04%) e que, relativamente às lesões tumorais, os melanomas (malignos) foram os mais frequentes (21,15%) comparativamente com os melanocitomas (benignos) (4,81%). Pela análise comparativa das características macroscópicas e microscópicas, verificou-se que, nem sempre, por uma avaliação macroscópica, é possível a distinção entre essas lesões (melanoses, melanocitomas e melanomas). No entanto, identificaram-se, neste estudo, algumas características sugestivas da malignidade, como: o tamanho superior a 2,5cm, a presença de ulceração, a libertação de pigmento negro e a presença de coloração negra do gânglio linfático regional. É, portanto, de extrema importância a observação criteriosa e sistemática dessas lesões, para a avaliação das suas características, uma vez que a decisão sanitária é diferente consoante se trate de uma melanose, de um tumor maligno ou de um tumor benigno.

Are there real advantages of induction therapy with basiliximab in renal transplantation?

BACKGROUND

Randomized clinical trials have supported the use of interleukin-2 receptor (IL-2R) antagonists as induction therapy in renal transplantation. This strategy has reduced the incidence of acute rejection episodes (ARE) but not improved graft survival. Our objective was to investigate the impact of induction therapy using the IL-2R antagonist basiliximab, as compared with no induction therapy, on relevant clinical outcomes-initial length of stay, incidence of ARE, long-term graft function, and graft survival.

METHODS

We retrospectively reviewed the medical records of patients transplanted in a tertiary care center between 1996 and 2011. We selected patients who received cyclosporine, mycophenolate mofetil, and prednisolone (n = 334) to classify as: no induction therapy (n = 131; group 1); induction therapy with basiliximab (n = 203; group 2). Estimated glomerular filtration rate (eGFR) was assessed with the 4-variable Modification of Diet in Renal Disease (MDRD) equation.

RESULTS

Mean follow-up was 72.7 ± 35.4 months. Patients who received basiliximab had a shorter mean hospital stay (19.2 versus 22.5 days; P = .02), lower incidence of ARE (10.8% versus 23.7%; P = .02) and better graft function post transplantation at 12 months (mean eGFR 59.4 ± 18.4 versus 54.8 ± 18.7 mL/min/1.73 m(2); P = .015) and 5 years (mean eGFR 64.1 ± 21.5 versus 55.4 ± 19.6 mL/min/1.73 m(2); P = .009). On multivariate analysis, induction therapy with basiliximab was independently associated with a lower incidence of ARE and better graft function at 1 and 5 years after transplantation. There was no difference in 5-year graft survival between the two groups (log-rank: P = .54).

CONCLUSIONS

Induction therapy with basiliximab was associated with a reduced incidence of ARE and better long-term graft function but no difference in 5-year graft survival.

Guidelines for maintenance of adult patients with brain death and potential for multiple organ donations: the Task Force of the Brazilian Association of Intensive Medicine the Brazilian Association of Organs Transplantation, and the Transplantation Center of Santa Catarina

INTRODUCTION

The organ shortage for transplantation, the principal factor that increases waiting lists, has become a serious public health problem. In this scenario, the intensivist occupies a prominent position as one of the professionals that first has a chance to identify brain death and to be responsible for the maintenance of the potential deceased donor.

OBJECTIVE

This report attempts to establish guidelines for care and maintenance of adult deceased donor organs guiding and standardizing care provided to patients with brain death.

METHOD

These guidelines were composed by intensivists, transplant coordinators, professionals from various transplant teams, and used transplant center. The formulated questions were forwarded to all members and recommendations were constructed after an extensive literature review selecting articles with the highest degree of evidence.

RESULTS

Guidelines were developed in the form of questions reflecting frequent experiences in clinical intensive care practices. The main questions were: Is there an optimal interval for keeping organs of deceased donors viable? What actions are considered essential for maintaining deceased donors in this period? What are the limits of body temperature? How should the patient be warmed? Which laboratory tests should be performed? What is the collection interval? What are the limits in the laboratory and the capture scenario? What are the limits of blood pressure? When and how should one use catecholamines?

CONCLUSIONS

This pioneer project involved a multidisciplinary team working in organ transplantation seeking to provide treatment guidance to increase the number of viable organs from deceased adult donors.

Experimental models in vaccine research: malaria and leishmaniasis

Animal models have a long history of being useful tools, not only to test and select vaccines, but also to help understand the elaborate details of the immune response that follows infection. Different models have been extensively used to investigate putative immunological correlates of protection against parasitic diseases that are important to reach a successful vaccine. The greatest challenge has been the improvement and adaptation of these models to reflect the reality of human disease and the screening of vaccine candidates capable of overcoming the challenge of natural transmission. This review will discuss the advantages and challenges of using experimental animal models for vaccine development and how the knowledge achieved can be extrapolated to human disease by looking into two important parasitic diseases: malaria and leishmaniasis.

One year of Lamivudine therapy for portuguese patients with chronic hepatitis B

OBJECTIVE

To assess the efficacy of lamivudine treatment on hepatitis B e antigen (HBeAg) and/or hepatitis B surface antigen (HBsAg) seroconversion, on other virological and serological markers of response including hepatitis B virus (HBV) DNA and serum aminotransferases, and the safety of lamivudine treatment in hepatitis B patients.

PATIENTS

This phase III open-label study evaluated the virological and biochemical response to lamivudine in 70 Portuguese patients with HBeAg positive chronic hepatitis B. Patients were treated with lamivudine 100mg once daily for 12 months.

METHODS

Antiviral activity was assessed by measuring alanine aminotransferase (ALT)/aspartate aminotransferase (AST) levels at all protocol visits, and hepatitis B serology and HBV DNA were performed at baseline and at month 12 visits. Evaluation of safety and tolerance was based on clinical adverse events and laboratory analyses.

RESULTS

The primary endpoint was virological response at month 12, defined as loss of detectable HBeAg from serum with a reduction of HBV DNA to undetectable levels, and this was observed in 19/69 (27.5%) of patients. Almost half of the patients were HBV DNA negative by this time. Mean ALT values decreased steadily during treatment and by 12 months 61% of patients had values within the normal range. HBeAg seroconversion (HBeAg negative, HBeAb positive) was achieved in 27.9% of patients by 12 months, although all patients remained HBsAg positive.

CONCLUSION

Lamivudine was well tolerated and the incidence of adverse events was similar to those reported in previous studies. Lamivudine treatment resulted in virological and biochemical improvements in HBeAg positive chronic hepatitis B patients, with HBeAg seroconversion in one-third of patients.