An Sfi1-like centrin-interacting centriolar plaque protein affects nuclear microtubule homeostasis.

Malaria-causing parasites achieve rapid proliferation in human blood through multiple rounds of asynchronous nuclear division followed by daughter cell formation. Nuclear divisions critically depend on the centriolar plaque, which organizes intranuclear spindle microtubules. The centriolar plaque consists of an extranuclear compartment, which is connected via a nuclear pore-like structure to a chromatin-free intranuclear compartment. Composition and function of this non-canonical centrosome remain largely elusive. Centrins, which reside in the extranuclear part, are among the very few centrosomal proteins conserved in Plasmodium falciparum. Here we identify a novel centrin-interacting centriolar plaque protein. Conditional knock down of this Sfi1-like protein (PfSlp) caused a growth delay in blood stages, which correlated with a reduced number of daughter cells. Surprisingly, intranuclear tubulin abundance was significantly increased, which raises the hypothesis that the centriolar plaque might be implicated in regulating tubulin levels. Disruption of tubulin homeostasis caused excess microtubules and aberrant mitotic spindles. Time-lapse microscopy revealed that this prevented or delayed mitotic spindle extension but did not significantly interfere with DNA replication. Our study thereby identifies a novel extranuclear centriolar plaque factor and establishes a functional link to the intranuclear compartment of this divergent eukaryotic centrosome.

Repurposing of MitoTam: Novel Anti-Cancer Drug Candidate Exhibits Potent Activity against Major Protozoan and Fungal Pathogens.

Many of the currently available anti-parasitic and anti-fungal frontline drugs have severe limitations, including adverse side effects, complex administration, and increasing occurrence of resistance. The discovery and development of new therapeutic agents is a costly and lengthy process. Therefore, repurposing drugs with already established clinical application offers an attractive, fast-track approach for novel treatment options. In this study, we show that the anti-cancer drug candidate MitoTam, a mitochondria-targeted analog of tamoxifen, efficiently eliminates a wide range of evolutionarily distinct pathogens in vitro, including pathogenic fungi, Plasmodium falciparum, and several species of trypanosomatid parasites, causative agents of debilitating neglected tropical diseases. MitoTam treatment was also effective in vivo and significantly reduced parasitemia of two medically important parasites, Leishmania mexicana and Trypanosoma brucei, in their respective animal infection models. Functional analysis in the bloodstream form of T. brucei showed that MitoTam rapidly altered mitochondrial functions, particularly affecting cellular respiration, lowering ATP levels, and dissipating mitochondrial membrane potential. Our data suggest that the mode of action of MitoTam involves disruption of the inner mitochondrial membrane, leading to rapid organelle depolarization and cell death. Altogether, MitoTam is an excellent candidate drug against several important pathogens, for which there are no efficient therapies and for which drug development is not a priority.

Renal Autotransplantation for The Treatment of Renal Artery Aneurysm.

OBJECTIVE: Renal artery aneurysms are a rare condition; however, the rate of diagnosis has been increasing, because of the increasing use of complementary diagnostic methods. The best treatment strategy for RAAs remains controversial. Data on ex-vivo surgery associated with kidney autotransplantation are scarce. As a result, the goal of this study was to describe this technique and to report our results. METHODS: A retrospective monocentric study was undertaken using the clinical records and images of 35 patients diagnosed with renal artery aneurysm from 01/01/2010 to 31/12/2018. Indications for ex vivo surgery and autotransplantation were complex aneurysms with diameter >20 mm or rapid growth or symptomatic aneurysms or women wishing to become pregnant. Complex aneurysms were defined by anatomical criteria (bifurcation of the renal artery and its primary branches or hilar aneurysms) and/or physiological criteria (when time of warm ischemia in in-situ reconstruction is expected to last more than 45 minutes). The technique of ex-vivo surgery and autotransplantation consists of performing a nephrectomy, renal cooling, treatment of aneurysm in banking and implantation of the kidney in the homolateral iliac fossa. RESULTS: A total of 35 patients with 56 renal artery aneurysms (26 women, mean age 52.4 years-minimum and maximum 16 and 74 years) were included. Of these, 27 were treated by surgery and 8 were followed clinically. Among those treated surgically, 24 performed ex vivo surgery associated with autotransplantation. Regarding ex vivo surgery, nephrectomy was performed by laparoscopic surgery in 24 of the 27 surgeries, the mean surgical time was 5.3 hours, the median warm ischemia time was 4 minutes and the length of hospital stay was 12.2 days. Mortality was 0% and the kidney patency rate was 93% with a follow up of 47.2 months. Of the 17 patients with hypertension, 6 cured it, 4 improved and 7 maintained hypertension. CONCLUSION: Kidney autotransplantation appears to be efficient for most complex RAA with the possibility to minimize surgical aggression by performing laparoscopic nephrectomy.

Bioluminescence Method for In Vitro Screening of Plasmodium Transmission-Blocking Compounds.

The sporogonic stage of the life cycle of Plasmodium spp., the causative agents of malaria, occurs inside the parasite's mosquito vector, where a process of fertilization, meiosis, and mitotic divisions culminates in the generation of large numbers of mammalian-infective sporozoites. Efforts to cultivate Plasmodium mosquito stages in vitro have proved challenging and yielded only moderate success. Here, we describe a methodology that simplifies the in vitro screening of much-needed transmission-blocking (TB) compounds employing a bioluminescence-based method to monitor the in vitro development of sporogonic stages of the rodent malaria parasite Plasmodium berghei Our proof-of-principle assessment of the in vitro TB activity of several commonly used antimalarial compounds identified cycloheximide, thiostrepton, and atovaquone as the most active compounds against the parasite's sporogonic stages. The TB activity of these compounds was further confirmed by in vivo studies that validated our newly developed in vitro approach to TB compound screening.

Inhibition of Plasmodium Liver Infection by Ivermectin.

Avermectins are powerful endectocides with an established potential to reduce the incidence of vector-borne diseases. Here, we show that several avermectins inhibit the hepatic stage of Plasmodium infection in vitro Notably, ivermectin potently inhibits liver infection in vivo by impairing parasite development inside hepatocytes. This impairment has a clear impact on the ensuing blood stage parasitemia, reducing disease severity and enhancing host survival. Ivermectin has been proposed as a tool to control malaria transmission because of its effects on the mosquito vector. Our study extends the effect of ivermectin to the early stages of mammalian host infection and supports the inclusion of this multipurpose drug in malaria control strategies.

Novel squaramides with in vitro liver stage antiplasmodial activity.

A structure-activity relationship study was performed with ten 8-aminoquinoline-squaramides compounds active against liver stage malaria parasites, using human hepatoma cells (Huh7) infected by Plasmodium berghei parasites. In addition, their blood-schizontocidal activity was assessed against chloroquine-resistant W2 strain Plasmodium falciparum. Compound 3 was 7.3-fold more potent than the positive control primaquine against liver-stage parasites, illustrating the importance of the squarate moiety to activity.

Chloroquine-containing organoruthenium complexes are fast-acting multistage antimalarial agents.

We report the pharmacological activity of organoruthenium complexes containing chloroquine (CQ) as a chelating ligand. The complexes displayed intraerythrocytic activity against CQ-sensitive 3D7 and CQ-resistant W2 strains of Plasmodium falciparum, with potency and selectivity indexes similar to those of CQ. Complexes displayed activity against all intraerythrocytic stages, but moderate activity against Plasmodium berghei liver stages. However, unlike CQ, organoruthenium complexes impaired gametocyte viability and exhibited fast parasiticidal activity against trophozoites for P. falciparum. This functional property results from the ability of complexes to quickly induce oxidative stress. The parasitaemia of P. berghei-infected mice was reduced by treatment with the complex. Our findings demonstrated that using chloroquine for the synthesis of organoruthenium complexes retains potency and selectivity while leading to an increase in the spectrum of action and parasite killing rate relative to CQ.

Evaluation of artemether-lumefantrine efficacy in the treatment of uncomplicated malaria and its association with pfmdr1, pfatpase6 and K13-propeller polymorphisms in Luanda, Angola.

BACKGROUND: Drug resistance in Plasmodium falciparum has posed an obstacle to effective treatment and challenges many malaria control programmes in endemic areas. In Angola, until 2003, chloroquine (CQ) was used as first-line therapy for uncomplicated malaria. It was replaced initially by amodiaquine and, in 2006, by artemisinin-based combination therapy (ACT) with artemether-lumefantrine (AL, Coartem(®)). Efficacy study of ACT, conducted in Angola between 2004 and 2005, showed a baseline efficacy of ≈99%. METHODS: 103 malaria patients were enrolled according to WHO proceedings. Patients were followed up with clinical and parasitological evaluations for 28 days, parasite density and identification was evaluated by microscopy, the pfmsp2 were genotyped by nested-PCR, to distinguish parasite recrudescence from new infections; the polymorphisms at codons 86 and 1246 of pfmdr1 gene, and 769 of pfatp6 gene were assessed by PCR-RFLP and sequencing for pfk13-propeller genotype. RESULTS: The cure rate was 91.3%. The obtained results showed that from 103 patients, 12.6% (n = 13) still had parasitaemia 1 day after the treatment was finished. On day 0, of the 94 evaluated samples, wild-type alleles were identified in 73.4% (n = 69) for pfmdr1 N86Y position and only one sample carried the mutant allele (Y) for pfmdr1 1246; 14% of these samples showed increased pfmdr1 copy number; 100% (n = 21) had wild-type allele of k13 gene in all the studied positions. DISCUSSION: These results showed changes in parasite profile susceptibility to AL in comparison to the baseline data from 2002 to 2004 and on the genotyping characteristics; the clinical outcome after treatment with AL did not link a particular genotype with treatment failure; observed changes do not provide sufficient evidence for a treatment policy change, but they suggest that a carefully monitoring is needed in this area.

The anti-allergic activity of Cymbopogon citratus is mediated via inhibition of nuclear factor kappa B (Nf-Κb) activation.

BACKGROUND: The prevalence of allergic diseases such as asthma has significantly increased worldwide, making it a public health concern. There is an urgent need for new anti-inflammatory agents with selective pharmacology and lower toxicity. Plant extracts have been used for centuries in traditional medicine to alleviate inflammatory diseases. In this work, we evaluated the anti-allergic activity of Cymbopogon citratus (Cy), a medicinal herb used by folk medicine to treat asthma. METHODS: We used a murine model of respiratory allergy to the mite Blomia tropicalis (Bt) and evaluated certain parameters known to be altered in this model. A/J mice were sensitized (100 µg/animal s.c.) and challenged (10 µg/animal i.n.) with Bt mite extract and treated with 60, 120 or 180 mg/kg of Cy standardized hexane extract. The parameters evaluated included: cellular infiltrate in bronchoalveolar lavage (BAL); eosinophil peroxidase activity (EPO); histopathological examination of the lung; serum levels of specific IgE, IgG1 and IgG2a; Th2 cytokine concentrations in BAL and expression of NF-κB. RESULTS: Our results showed that oral administration of a Cy hexane extract (especially 180 mg/Kg) reduced the numbers of leukocytes/eosinophils in BAL; the eosinophil peroxidase activity in BAL; the infiltration of leukocytes in lung tissue; the production of mucus in the respiratory tract; the level of IL-4 in BAL and the nuclear expression of NF-κB. CONCLUSIONS: The results presented demonstrate the potential of the Cy hexane extract to modulate allergic asthma; this extract may be an alternative future approach to treat this pathology.

Analysis of polymorphisms in Plasmodium falciparum genes related to drug resistance: a survey over four decades under different treatment policies in Brazil.

BACKGROUND: Anti-malarial resistance in Plasmodium falciparum remains an obstacle for malaria control. Resistance-associated genes were analysed in Brazilian samples over four decades to evaluate the impact of different treatment regimens on the parasite genetic profile. METHODS: Samples were collected on filter paper from patients infected in the Amazon region from 1984 to 2011. DNA was extracted with Chelex® 100 and monoinfection confirmed by PCR. SNPs in the pfcrt, pfmdr1, pfdhfr and pfdhps genes were assessed by PCR-RFLP. The pfmdr1 copy number was estimated using real time quantitative PCR with SYBR® Green. Parasite response was assessed ex vivo with seven concentrations of each anti-malarial. Patients were treated according to Brazilian guidelines: quinine plus tetracycline or mefloquine in period 1 and ACT in period 2. RESULTS: All 96 samples presented the pfcrt 76T mutant throughout the assessed periods. In addition, all isolates showed ex vivo chloroquine resistance. The pfmdr1 86Y was detected in 1.5% of samples in period 1, and in 25% in period 2. All samples presented the pfmdr1 1246Y. The analysis of pfmdr1 copy number showed amplification in 37.3% in period 1 and in 42% in period 2. Mutations in pfdhfr were shown as follows: 51I in all samples in period 1 and in 81.2% in period 2; 59R in 6.4% in period 2. The pfdhfr 108N and the pfdhps 437G were seen in all samples along time; the pfdhps 540E in 93.7% in period 1 and in 75% in period 2. CONCLUSIONS: The 76T mutation associated to chloroquine resistance is still present in the parasite population, although this anti-malarial was withdrawn from the chemotherapy of P. falciparum in Brazil in the mid-1980s. All isolates assayed ex vivo for chloroquine showed resistant phenotype and 76T. No association was observed between pfmdr1 mutations and resistance to quinine, mefloquine and artemisinin derivatives. Additionally, the pfdhfr 108N mutation was detected in all samples throughout the evaluated periods, demonstrating fixation of the mutant allele in the parasite population. Changes in Brazilian national guidelines for the malaria chemotherapy in the last 27 years yielded a discreet genetic impact in the parasite population.

Chelation of Mitochondrial Iron as an Antiparasitic Strategy.

Iron, as an essential micronutrient, plays a crucial role in host-pathogen interactions. In order to limit the growth of the pathogen, a common strategy of innate immunity includes withdrawing available iron to interfere with the cellular processes of the microorganism. Against that, unicellular parasites have developed powerful strategies to scavenge iron, despite the effort of the host. Iron-sequestering compounds, such as the approved and potent chelator deferoxamine (DFO), are considered a viable option for therapeutic intervention. Since iron is heavily utilized in the mitochondrion, targeting iron chelators in this organelle could constitute an effective therapeutic strategy. This work presents mitochondrially targeted DFO, mitoDFO, as a candidate against a range of unicellular parasites with promising in vitro efficiency. Intracellular Leishmania infection can be cleared by this compound, and experimentation with Trypanosoma brucei 427 elucidates its possible mode of action. The compound not only affects iron homeostasis but also alters the physiochemical properties of the inner mitochondrial membrane, resulting in a loss of function. Furthermore, investigating the virulence factors of pathogenic yeasts confirms that mitoDFO is a viable candidate for therapeutic intervention against a wide spectrum of microbe-associated diseases.

Plasmodium falciparum CRK4 links early mitotic events to the onset of S-phase during schizogony.

Plasmodium falciparum proliferates through schizogony in the clinically relevant blood stage of infection. During schizogony, consecutive rounds of DNA replication and nuclear division give rise to multinucleated stages before cellularization occurs. Although these nuclei reside in a shared cytoplasm, DNA replication and nuclear division occur asynchronously. Here, by mapping the proteomic context of the S-phase-promoting kinase PfCRK4, we show that it has a dual role for nuclear-cycle progression: PfCRK4 orchestrates not only DNA replication, but in parallel also the rearrangement of intranuclear microtubules from hemispindles into early mitotic spindles. Live-cell imaging of a reporter parasite showed that these microtubule rearrangements coincide with the onset of DNA replication. Together, our data render PfCRK4 a key factor for nuclear-cycle progression, linking entry into S-phase with the initiation of mitotic events. In part, such links may compensate for the absence of canonical cell cycle checkpoints in P. falciparum. IMPORTANCE The human malaria parasite Plasmodium falciparum proliferates in erythrocytes through schizogony, forming multinucleated stages before cellularization occurs. In marked contrast to the pattern of proliferation seen in most model organisms, P. falciparum nuclei multiply asynchronously despite residing in a shared cytoplasm. This divergent mode of replication is, thus, a good target for therapeutic interventions. To exploit this potential, we investigated a key regulator of the parasite's unusual cell cycle, the kinase PfCRK4 and found that this kinase regulated not only DNA replication but also in parallel the rearrangement of nuclear microtubules into early mitotic spindles. Since canonical cell cycle checkpoints have not been described in P. falciparum parasites, linking entry into S-phase and the initiation of mitotic events via a kinase, may be an alternative means to exert control, which is typically achieved by checkpoints.

Paraneoplastic Aquagenic Pruritus: A Case of Pancreatic Cancer.

Paraneoplastic pruritus has been reported mostly in association with haematological malignancies, and rarely with solid tumours. Aquagenic pruritus is itching without any skin lesion that develops a few minutes after contact with water of any temperature and it is associated with polycythaemia vera or other lymphoproliferative diseases. Here we report a case of a previously healthy 78-year-old Portuguese woman, who had been treated unsuccessfully for aquagenic pruritus for the previous eight months, and presented to the emergency department complaining of pain and swelling in her left leg. Deep vein thrombosis was diagnosed and oral anticoagulation was initiated. Blood tests revealed a normal blood count and normal liver enzymes, except for alkaline phosphatase and lactate dehydrogenase levels, which were slightly elevated. Hypercobalaminaemia and folic acid deficiency were also noted. JAK2 V617F/12 exon mutation was not present. Thoracic, abdominal and pelvic computed tomography revealed a locally advanced pancreatic tumour. Ultrasound-guided fine-needle aspiration cytology of the lesion revealed a moderately differentiated adenocarcinoma of pancreatic ductal origin. Tumour marker assays showed elevation of both carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA 19-9). Aquagenic pruritus should be thoroughly investigated to exclude a neoplastic disease, especially if treatment is refractory or if another paraneoplastic syndrome is present. Although aquagenic pruritus is more commonly associated with haematological malignancies than solid tumours, a rare case of aquagenic pruritus is described here as a paraneoplastic syndrome of pancreatic cancer. To the best of our knowledge, this is the first case of pancreatic cancer that presented with aquagenic pruritus and dual paraneoplastic syndromes.

Total Pelvic Exenteration surgery - Considerations for healthcare professionals.

BACKGROUND: Associated with considerable risk of morbidity, Total Pelvic Exenteration (TPE) is a life-altering procedure involving a significant prolonged recovery. As a result, and with the view of achieving the best outcomes and lessen short and long-term morbidities, a well-thought-out and coordinated multidisciplinary team approach, is crucial to the provision of safe and high-quality care. METHOD: Using a nominal group technique and qualitative methodology, this article explores the current practices in the care of oncology patients who undergo TPE surgery, in a tertiary cancer centre, by highlighting considerations of a collaboratively multi-disciplinary team. RESULTS: This article provides guidance on the multi-disciplinary team approach, relating to TPE surgery, with discussion of clinical concerns, and with the goal of high patient satisfaction, provision of effective care and the lessening of short and long-term morbidities. CONCLUSION: Oncology patients that undergo TPE surgery benefit from the contribution of a diversified multidisciplinary team as skilled and competent care that meets patient's health and social care needs is provided in a holistic, comprehensive, and timely care manner. Improving patient's care, pathway and postoperative outcomes, with the use of clinical expertise and support from professionals in the multidisciplinary team, can maximise care.

Latin America consensus statement inflammatory bowel disease: importance of timely access to diagnosis and treatment.

Background: Inflammatory bowel diseases (IBDs) are chronic conditions that negatively interferes with the quality of life of the patients, on a physical, emotional, and social level. Its symptoms can vary including diarrhea, bleeding, abdominal pain, fever, and weight loss, depending on the type and location and severity of the disease. Despite evolving treatment, they do not always achieve control of the symptoms, so between 23% and 45% of people with idiopathic chronic ulcerative colitis, and up to 75% of those with Crohn's disease, eventually, will need surgery. Objective: The increase in its incidence in Latin America has promoted a renewed interest on the part of the medical and scientific community in standardizing and unifying criteria for the proper diagnosis and management of the disease, which is part of the current discussions of various events; however, this interest has not yet been reflected in policies and initiatives by governments to address the disease. We decided to develop a consensus meeting in order to elucidate the actual situation of IBD care in our region. Design: The methodology employed to build the consensus document derived from a review of literature, evidence, and policies on IBD, followed by a process of validation and feedback with a group of 10 experts in the field. Methods: Nine experts from different countries in Latin America were reunited in web meetings on 2 days and voted on topics derived from the consensus document. A full agreement with 100% approval was needed, so topics were discussed to reach the consensus otherwise were removed. Results: There is still a lack of information about IBD in Latin America, therefore IBD continues to be an 'invisible' disease and is little recognized by decision-makers. Conclusion: This document describes the current situation of IBDs in the Latin American region, highlighting the main barriers and challenges in timely access to diagnosis and treatment, in order to demonstrate the need to promote the development and implementation of policies, in order to improve the quality of care of patients with IBD.

SECOND BRAZILIAN CONSENSUS ON THE MANAGEMENT OF ULCERATIVE COLITIS IN ADULTS: A CONSENSUS OF THE BRAZILIAN ORGANIZATION FOR CROHN'S DISEASE AND COLITIS (GEDIIB).

BACKGROUND: Inflammatory bowel diseases are immune-mediated disorders that include Crohn's disease (CD) and ulcerative colitis (UC). UC is a progressive disease that affects the colorectal mucosa causing debilitating symptoms leading to high morbidity and work disability. As a consequence of chronic colonic inflammation, UC is also associated with an increased risk of colorectal cancer. OBJECTIVE: This consensus aims to provide guidance on the most effective medical management of adult patients with UC. METHODS: A consensus statement was developed by stakeholders representing Brazilian gastroenterologists and colorectal surgeons (Brazilian Organization for Crohn's Disease and Colitis [GEDIIB]). A systematic review including the most recent evidence was conducted to support the recommendations and statements. All recommendations/statements were endorsed using a modified Delphi Panel by the stakeholders/experts in inflammatory bowel disease with at least 80% or greater consensus. RESULTS AND CONCLUSION: The medical recommendations (pharmacological and non-pharmacological) were mapped according to the stage of treatment and severity of the disease onto three domains: management and treatment (drug and surgical interventions), criteria for evaluating the effectiveness of medical treatment, and follow-up/patient monitoring after initial treatment. The consensus targeted general practitioners, gastroenterologists and surgeons who manage patients with UC, and supports decision-making processes by health insurance companies, regulatory agencies, health institutional leaders, and administrators.

SECOND BRAZILIAN CONSENSUS ON THE MANAGEMENT OF CROHN'S DISEASE IN ADULTS: A CONSENSUS OF THE BRAZILIAN ORGANIZATION FOR CROHN'S DISEASE AND COLITIS (GEDIIB).

BACKGROUND: Inflammatory bowel disease (IBD) is an immune-mediated disorder that includes Crohn's disease (CD) and ulcerative colitis. CD is characterized by a transmural intestinal involvement from the mouth to the anus with recurrent and remitting symptoms that can lead to progressive bowel damage and disability over time. OBJECTIVE: To guide the safest and effective medical treatments of adults with CD. METHODS: This consensus was developed by stakeholders representing Brazilian gastroenterologists and colorectal surgeons (Brazilian Organization for Crohn's disease and Colitis (GEDIIB)). A systematic review of the most recent evidence was conducted to support the recommendations/statements. All included recommendations and statements were endorsed in a modified Delphi panel by the stakeholders and experts in IBD with an agreement of at least 80% or greater consensus rate. RESULTS AND CONCLUSION: The medical recommendations (pharmacological and non-pharmacological interventions) were mapped according to the stage of treatment and severity of the disease in three domains: management and treatment (drug and surgical interventions), criteria for evaluating the effectiveness of medical treatment, and follow-up/patient monitoring after initial treatment. The consensus is targeted towards general practitioners, gastroenterologists, and surgeons interested in treating and managing adults with CD and supports the decision-making of health insurance companies, regulatory agencies, and health institutional leaders or administrators.

Asynchronous nuclear cycles in multinucleated Plasmodium falciparum facilitate rapid proliferation.

Malaria-causing parasites proliferate within erythrocytes through schizogony, forming multinucleated stages before cellularization. Nuclear multiplication does not follow a strict geometric 2n progression, and each proliferative cycle produces a variable number of progeny. Here, by tracking nuclei and DNA replication, we show that individual nuclei replicate their DNA at different times, despite residing in a shared cytoplasm. Extrapolating from experimental data using mathematical modeling, we provide strong indication that a limiting factor exists, which slows down the nuclear multiplication rate. Consistent with this prediction, our data show that temporally overlapping DNA replication events were significantly slower than partially overlapping or nonoverlapping events. Our findings suggest the existence of evolutionary pressure that selects for asynchronous DNA replication, balancing available resources with rapid pathogen proliferation.