An insight into differential protein abundance throughout Leishmania donovani promastigote growth and differentiation.

Leishmania donovani causes anthroponotic visceral leishmaniasis, responsible for about 50,000 annual deaths worldwide. Current therapies have considerable side effects. Drug resistance has been reported and no vaccine is available nowadays. The development of undifferentiated promastigotes in the sand fly vector's gut leads to the promastigote form that is highly infective to the mammalian host. Fully differentiated promastigotes play a crucial role in the initial stages of mammalian host infection before internalization in the host phagocytic cell. Therefore, the study of protein levels in the promastigote stage is relevant for disease control, and proteomics analysis is an ideal source of vaccine candidate discovery. This study aims to get insight into the protein levels during the differentiation process of promastigotes by 2DE-MALDI-TOF/TOF. This partial proteome analysis has led to the identification of 75 proteins increased in at least one of the L. donovani promastigote differentiation and growth phases. This study has revealed the differential abundance of said proteins during growth and differentiation. According to previous studies, some are directly involved in parasite survival or are immunostimulatory. The parasite survival-related proteins are ascorbate peroxidase; cystathionine ß synthase; an elongation factor 1ß paralog; elongation factor 2; endoribonuclease L-PSP; an iron superoxide dismutase paralog; GDP-mannose pyrophosphorylase; several heat shock proteins-HSP70, HSP83-17, mHSP70-rel, HSP110; methylthioadenosine phosphorylase; two thiol-dependent reductase 1 paralogs; transitional endoplasmic reticulum ATPase; and the AhpC thioredoxin paralog. The confirmed immunostimulatory proteins are the heat shock proteins, enolase, and protein kinase C receptor analog. The potential immunostimulatory molecules according to findings in patogenic bacteria are fructose-1,6-diphophate aldolase, dihydrolipoamide acetyltransferase, isocitrate dehydrogenase, pyruvate dehydrogenase E1α and E1ß subunits, and triosephosphate isomerase. These proteins may become disease control candidates through future intra-vector control methods or vaccines.

Effectiveness, Toxicity, and Survival Predictors of Regorafenib in Metastatic Colorectal Cancer: A Multicenter Study of Routinely Collected Data.

OBJECTIVES: To assess the effectiveness and toxicity of regorafenib in patients with metastatic colorectal cancer (mCRC) in routine clinical practice, as well as predictive factors of effectiveness. METHODS: This was a retrospective multicenter study in patients with mCRC who received regorafenib from November 2013 to May 2020. Effectiveness was evaluated by overall survival (OS) and progression-free survival (PFS) using the Kaplan-Meier method. Cox regression was performed to determine survival predictors. RESULTS: Ninety patients were enrolled (median age, 64.3 years). Fifty-two patients (57.8%) were male, and 57 (63.3%) had an ECOG performance status (PS) of 0 to 1. Median follow-up was 2.80 months. Median OS was 8.03 months (95% CI, 5.90-10.17), and median PFS was 2.90 months (95% CI, 2.59-3.21). Eighty-eight patients (97.8%) experienced drug-related adverse events. The most frequent were fatigue in 66 patients (73.3%), followed by palmar-plantar erythrodysesthesia in 40 (44.4%). Low liver tumor burden score (LTBS) and good ECOG PS were independent OS predictive factors. CONCLUSIONS: Patients taking regorafenib had OS and PFS rates similar to those reported in previous randomized trials; the agent had a poor toxicity profile. We identified low LTBS and good ECOG PS as possible predictive factors of better OS, useful in selecting patients with mCRC who might benefit from regorafenib.