RESUMEN

INTRODUCTION: Standardized basic morphology and the algorithmic approach make the Paris System (TPS) for Reporting Urinary Cytology understandable and applicable. This study examined how well the TPS categories are understood by pathology residents and how well these criteria are enabling them reaching accurate diagnosis. MATERIALS/METHODS: A hundred consecutive cases representing all categories were selected. Authors reevaluated slides using TPS regardless of their original diagnosis. In the next step, the TPS was explained to four residents and trained them by five optimal urine cytology samples from each category. Then they were asked to diagnose the selected slides according to the TPS. The diagnoses were compared to authors. The agreement was assessed using kappa. Discordant diagnoses were classified as high and low impact based on potential on clinical practice. RESULTS: The sensitivity of authors was 62.8%, and residents' were 24-31.8%. The specificity of authors was 98.8%, and residents' were 82.3-92.8%. Reproducibility of TPS was 40-46%. Kappa values were below 0.40 except for one resident. The highest rate of concordance was for negative for high-grade urothelial carcinoma (NHGUC): authors assigned 38 NHGUC (35 biopsy-proven benign cases). Twenty to twenty-six of them were assigned as NHGUC by residents. While authors assigned 42 cases as suspicious for high-grade urothelial carcinoma (SHGUC) or high-grade urothelial carcinoma (HGUC) (35 biopsy-proven malignant cases), residents assigned 22-29 of them. Discordant diagnosis with high clinical implication was 56-63%. CONCLUSION: Diagnostic accuracy rates of junior pathology residents using the TPS were unsatisfactory. The best agreement was observed in NHGUC and HGUC categories. Combining HGUC and SHGUC doubled the sensitivity of residents.

RESUMEN

The rapid emergence of drug resistance against the mainstream antimalarial drugs has increased the need for development of novel drugs. Recent approaches have embarked on the repurposing of existing drugs to induce cell death via programmed cell death pathways. However, little is known about the ER stress response and programmed cell death pathways of the malaria parasite. In this study, we treated ex vivo Plasmodium berghei cultures with tunicamycin, 5-fluorouracil, and chloroquine as known stress inducer drugs to probe the transcriptional changes of autophagy and apoptosis-related genes (PbATG5, PbATG8, PbATG12, and PbMCA2). Treatments with 5-fluorouracil and chloroquine resulted in the upregulation of all analyzed markers, yet the levels of PbATG5 and PbATG12 were dramatically higher in chloroquine-treated ex vivo cultures. In contrast, tunicamycin treatment resulted in the downregulation of both PbATG8 and PbATG12, and upregulation of PbMCA2. Our results indicate that the malaria parasite responds to various ER stressors by inducing autophagy- and/or apoptosis-like pathways.

Asunto(s)

RESUMEN

Endoplasmic reticulum (ER) plays a pivotal role in the regulation of stress responses in multiple eukaryotic cells. However, little is known about the effector mechanisms that regulate stress responses in ER of the malaria parasite. Herein, we aimed to identify the importance of a transmembrane protein 33 (TMEM33)-domain-containing protein in life cycle of the rodent malaria parasite Plasmodium berghei. TMEM33 is an ER membrane-resident protein that is involved in regulating stress responses in various eukaryotic cells. A C-terminal tagged TMEM33 was localized in the ER throughout the blood and mosquito stages of development. Targeted deletion of TMEM33 confirmed its importance for asexual blood stages and ookinete development, in addition to its essential role for sporozoite infectivity in the mammalian host. Pilot scale analysis shows that the loss of TMEM33 results in the initiation of ER stress response and induction of autophagy. Our findings conclude an important role of TMEM33 in the development of all life cycle stages of the malaria parasite, which indicates its potential as an antimalarial target.

Asunto(s)

RESUMEN

We generated highly chloroquine (CQ)-resistant (ResCQ) Plasmodium yoelii parasites by stepwise exposure to increasing concentrations of CQ and CQ-sensitive parasites (SenCQ) by parallel mock treatments. No mutations in genes that are associated with drug resistance were detected in ResCQ clones. Autophagy-related genes were highly upregulated in SenCQ compared to ResCQ parasites during CQ treatment. This indicates that CQ resistance can be developed in the malaria parasite by the inhibition of autophagy as an alternative drug resistance mechanism.

Asunto(s)