Cell division in apicomplexan parasites is organized by a homolog of the striated rootlet fiber of algal flagella

Apicomplexa are intracellular parasites that cause important human diseases including malaria and toxoplasmosis. During host cell infection new parasites are formed through a budding process that parcels out nuclei and organelles into multiple daughters. Budding is remarkably flexible in output and can produce two to thousands of progeny cells. How genomes and daughters are counted and coordinated is unknown. Apicomplexa evolved from single celled flagellated algae, but with the exception of the gametes, lack flagella. Here we demonstrate that a structure that in the algal ancestor served as the rootlet of the flagellar basal bodies is required for parasite cell division. Parasite striated fiber assemblins (SFA) polymerize into a dynamic fiber that emerges from the centrosomes immediately after their duplication. The fiber grows in a polarized fashion and daughter cells form at its distal tip. As the daughter cell is further elaborated it remains physically tethered at its apical end, the conoid and polar ring. Genetic experiments in Toxoplasma gondii demonstrate two essential components of the fiber, TgSFA2 and 3. In the absence of either of these proteins cytokinesis is blocked at its earliest point, the initiation of the daughter microtubule organizing center (MTOC). Mitosis remains unimpeded and mutant cells accumulate numerous nuclei but fail to form daughter cells. The SFA fiber provides a robust spatial and temporal organizer of parasite cell division, a process that appears hard-wired to the centrosome by multiple tethers. Our findings have broader evolutionary implications. We propose that Apicomplexa abandoned flagella for most stages yet retained the organizing principle of the flagellar MTOC. Instead of ensuring appropriate numbers of flagella, the system now positions the apical invasion complexes. This suggests that elements of the invasion apparatus may be derived from flagella or flagellum associated structures

A Conformally Invariant Holographic Two-Point Function on the Berger Sphere

We apply our previous work on Green's functions for the four-dimensional quaternionic Taub-NUT manifold to obtain a scalar two-point function on the homogeneously squashed three-sphere (otherwise known as the Berger sphere), which lies at its conformal infinity. Using basic notions from conformal geometry and the theory of boundary value problems, in particular the Dirichlet-to-Robin operator, we establish that our two-point correlation function is conformally invariant and corresponds to a boundary operator of conformal dimension one. It is plausible that the methods we use could have more general applications in an AdS/CFT context.Comment: 1+49 pages, no figures. v2: Several typos correcte

Chlorophenol removal from soil suspensions : effects of a specialised microbial inoculum and a degradable analogue

Two soils of different contamination history were tested in slurry for their self-remediability towards mono-, diand trisubstituted chlorophenols. The landfill soil showed poor ability in removing the compounds. Instead, the soil from the golf course, treated for many years with a 2,4,6-trichlorophenol derivative (Prochloraz), remediated different concentrations of the same 2,4,6TCP, 2,4-dichlorophenol and monochlorophenol isomers, singly and in mixtures, at varying degradation rates. Ralstonia eutropha TCP, a specialised microorganism capable of degrading 2,4,6TCP, proved highly efficient in removing the compound from both tested soils. The same microbial inoculum allowed total removal of the ternary mixture of monochlorophenol isomers from the golf course soil, but it did not accelerate the removal of the same compounds when singly supplied. The addition of phenol as a degradable analogue was more effective in co-metabolically removing not only the single monochlorophenols,but also their mixtures, the removal occurring faster and independently of the presence of the microbial inoculum. From the golf course soil, a microorganism, phenotypically and genetically identical to R. eutropha TCP, was isolated and classified as R. eutropha TCP II

A Holstein heifer infected with Neospora caninum NcUru3 congenitally transmits this strain to a viable offspring although infection does not protect her from aborting by a different N. caninum genotype in the subsequent gestation.

Abstract: Neospora caninum is a leading cause of bovine abortion worldwide. Although the genetic diversity of this apicomplexan parasite has long been recognized, there is little information on whether infection with different genotypes results in different clinical outcomes or whether infection by a given genotype impairs protective immunity against abortion induced by different genotypes. Here, we provide evidence supporting that natural subclinical infection with isolate NcUru3 of N. caninum in a pregnant heifer did not provide protection against abortion caused by a different N. caninum genotype in the subsequent gestation. A Holstein heifer delivered a healthy calf congenitally infected with N. caninum. Specific anti-N. caninum IgG was detected by indirect ELISA in sera obtained from the dam at calving and the calf before ingestion of colostrum, indicating in utero exposure to the parasite in the latter. A N. caninum strain named NcUru3 was isolated and characterized by multilocus microsatellite typing from the brain of this neonate euthanized at 9 days of age. Sixty days after calving, the cow got pregnant, although she aborted spontaneously at ~6 months of gestation. Pathologic examination of the aborted fetus and placenta revealed typical lesions of neosporosis, including encephalitis, myocarditis, hepatitis, myositis, and placentitis. Neospora caninum DNA was amplified from the fetal brain, heart, kidney, and placenta, and multilocus microsatellite typing revealed a genotype that differed from isolate NcUru3 at the level of microsatellite marker 6A (MS6A). Serum obtained from the dam at the time of abortion had IgG that cross-recognized isolate NcUru3, as demonstrated by immunoblotting, indicating that the humoral immune response did not prevent the other genotype from infecting the fetus and inducing fetoplacental lesions and abortion. This is the first description of one same dam transmitting two N. caninum genotypes to her offspring in subsequent gestations

Successful return to sport in patients with symptomatic borderline dysplasia following hip arthroscopy and T-shaped capsular plication

Purpose: This study aims to evaluate the return to sport and correlations of patients with symptomatic borderline hip dysplasia (BHD) after hip arthroscopy and T-shaped capsular plication at a minimum follow-up of 24 months. Methods: Twenty-five patients who underwent hip arthroscopy and T-shaped capsular plication for symptomatic BHD were included in the study. All the patients were evaluated clinically prior to surgery (T0) and at two consecutive follow-ups (T1:15 ± 1.2 months and T2: 53.9 ± 23.2 months) using the visual analogue scale (VAS) pain score, whereas sports activity was assessed by the Hip Outcome Score Sport Specific Subscale (HOS-SSS), the University of California, Los Angeles (UCLA) activity scale, the Tegner score and the physical component (PCS) of the Short Form-12 (SF-12). Furthermore, the presence of correlations and the possible differences between subgroups were evaluated and analysed. Results: A significant difference was found for HOS-SSS, VAS, Tegner, UCLA and PCS with the Friedman test for repeated measures through time points (p < 0.0001). Moreover, all the scores reported significant improvement compared to the previous time point (p < 0.0001) except the HOS-SSS between T1 and T2 (n.s.). Body Mass Index (BMI) was negatively correlated with HOS-SSS at T0 (rho = − 0.526 p = 0.006) and T1 (rho = − 0.425; p = 0.034), with Tegner at each follow-up (T0: rho = − 0470 p = 0.017; T1: rho = − 0.450; p = 0.024; T2: rho = − 0.448; p = 0.024), with UCLA at T1 (rho = − 0.396 p = 0.049), with pre-operative PCS (rho = − 0.413 p = 0.0401), and positively correlated with pre-operative VAS (rho = 0.436 p = 0.0291). Conclusions: Hip arthroscopy and T-shaped capsular plication in young patients with symptomatic BHD demonstrates a significant increase in return to sport and physical activity and low risk of complications. T-shaped capsular plication procedure may be considered in young and active patients for whom non-operative treatment failed and who have a significant limitation in sports activity; in these patterns of patients, the ideal treatment should reliably allow fast recovery in combination with very low invasiveness which will prevent osteoarthritis. The results of this study provide more accurate information regarding return to sport in patients with BHD after hip arthroscopy and T-shaped capsular plication. Level of evidence: Level IV. © 2020, European Society of Sports Traumatology, Knee Surgery, Arthroscopy (ESSKA)

Generación de nuevas herramientas para el control de Neospora caninum a partir de un enfoque epidemiológico y genómico. [Resumen]

Abstract: Neospora caninum es el agente etiológico de la neosporosis bovina, una de las principales causas de aborto bovino en el mundo. Esta enfermedad produce pérdidas millonarias con un gran impacto económico en el sector ganadero, principalmente en el ganado lechero. Sin embargo, se sabe muy poco sobre la biología de este parásito. A través de un trabajo multicéntrico, nos propusimos profundizar en la situación local y global, siendo el objetivo de este trabajo la caracterización a nivel genético y fenotípico, de las cepas circulantes y su comparación con cepas de referencia, de forma de poder adaptar las herramientasdiagnósticas y profilácticas a las necesidades de la región. Por un lado aislamos cuatro cepas de tres regiones distintas de Uruguay, y mediante un análisis de microsatélites determinamos la existencia de una importante diversidad genética en esta especie. Los diversos perfiles de tipificación por microsatélites se correlacionaron con diferencias fenotípicas en transmisión vertical, virulencia y potencial abortivo en modelos murinos. Asimismo, la tipificación por microsatélites del ADN de N. caninum de fetos bovinos abortados espontáneamente de granjas lecheras se correlacionó con mayor frecuencia con uno de los aislados, lo que sugiere que diferentes cepas pueden tener diferentes potenciales abortivos. A partir de estos hallazgos decidimos realizar un análisis comparativo más profundode la diversidad genética de cepas, pero ahora a nivel global, y determinamos que N. caninum presenta una importante complejidad genética, exhibiendo al menos seis clusters o grupos de tipificación. Finalmente, la secuenciación completa del genoma usando la tecnología PacBio reveló un ensamblaje impreciso del genoma de referencia de N. caninum, lo que nos llevó a reensamblar y anotar este genoma.Financiación: FSSA_X_2014_1_106026 ANII-INIA

Causes of abortion in dairy cows in Uruguay. [Causas de aborto em bovinos de leite no Uruguai].

Abstract: A case series study was conducted to determine the frequency of causes of abortion in dairy cattle in Uruguay. The sample size of 102 cases was composed of 53 fetuses, 35 fetuses with placentas, and 14 placentas without an associated fetus. All cases underwent grossand microscopic pathologic examinations as well as microbiological and serological testing. The etiology was determined in 54 (53%) of cases, 51 of which were caused by infectious agents. Within the observed 102 cases, 30 (29%) were caused by Neospora caninum, six (6%) by Coxiella burnetii and two (2%) by Campylobacter fetus subsp. venerealis. Bovine Parainfluenza-3 virus and Salmonella enterica serovar Newport caused one abortion each. Opportunistic bacteria (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenes, and Providencia stuartii) were associated with 11 abortions. In two cases the fetal death was attributed to dystocia, and in one case the fetus had a congenital mesothelioma. Bovine viral diarrhea virus (BVDV) infection was identified in three fetuses; two of which were co-infected with and had typical lesions of N. caninum. No lesions were observed in the other fetus infected by BVDV. Leptospira interrogans was identified in one fetuswithout lesions. Despite the relatively low overall success rate in establishing an etiological diagnosis in cases of abortion in cattle, a systemic workup of bovine abortion is necessary to establish prevention and control strategies. This also facilitates monitoring and surveillance of reproductive diseases in dairy cattle, some of which represent a risk to public health.Resumo: Uma série de casos foi estudada para determinar a frequência de causas do aborto em bovinos leiteiros no Uruguai. A amostra, de 102 casos, foi composta por 53 fetos, 35 fetos com placentas e 14 placentas sem feto associado. Todos os casos foram submetidos a exames patológicos macroscópicos e microscópicos, além de testes microbiológicos e sorológicos.A etiologia foi determinada em 54 (53%) dos casos, 51 dos quais foram causados por agentes infecciosos. Nos 102 casos observados, 30 (29%) foram causados por Neospora caninum, seis (6%) por Coxiella burnetii e dois (2%) por Campylobacter fetus subsp. venerealis. O vírus da Parainfluenza-3 e Salmonella enterica serovar Newport causaram um aborto cada. Bactérias oportunistas (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenese Providencia stuartii) foram associadas a 11 abortos. Em dois casos, a morte fetal foi atribuída a distocia e, em um caso, o feto apresentava mesotelioma congênito. A infecção pelo vírus da diarreia viral bovina (BVDV) foi identificada em três fetos; dois dos quais foram co-infectados e apresentavam lesões típicas de N. caninum. Não foram observadas lesões no outro feto infectado pelo BVDV. Leptospira interrogans foiidentificada em um feto sem lesões. Apesar da relativamente baixa taxa de sucesso no diagnóstico etiológico nos casos de aborto em bovinos, é necessário o diagnóstico sistemático dos abortos para estabelecer estratégias de prevenção e controle. Isso também facilita o monitoramento e a vigilância de doenças reprodutivas em bovinos leiteiros, algumas das quais representam um risco para a saúde pública

Implantation technique and optimal subcutaneous defibrillator chest position: A PRAETORIAN score-based study

Aims The traditional technique for subcutaneous implantable cardioverter-defibrillator (S-ICD) implantation involves three incisions and a subcutaneous pocket. Recently, a two-incision and intermuscular (IM) technique has been adopted. The PRAETORIAN score is a chest radiograph-based tool that predicts S-ICD conversion testing. We assessed whether the S-ICD implantation technique affects optimal position of the defibrillation system according to the PRAETORIAN score. Methods We analysed consecutive patients undergoing S-ICD implantation. The v2 test and regression analysis were used to and results determine the association between the PRAETORIAN score and implantation technique. Two hundred and thirteen patients were enrolled. The S-ICD generator was positioned in an IM pocket in 174 patients (81.7%) and the two-incision approach was adopted in 199 (93.4%). According to the PRAETORIAN score, the risk of conversion failure was classified as low in 198 patients (93.0%), intermediate in 13 (6.1%), and high in 2 (0.9%). Patients undergoing the two-incision and IM technique were more likely to have a low (<90) PRAETORIAN score than those undergoing the three-incision and subcutaneous technique (two-incision: 94.0% vs. three-incision: 78.6%; P = 0.004 and IM: 96.0% vs. subcutaneous: 79.5%; P = 0.001). Intermuscular plus two-incision technique was associated with a low-risk PRAETORIAN score (hazard ratio 3.76; 95% confidence interval 1.01\u201314.02; P = 0.04). Shock impedance was lower in PRAETORIAN low-risk patients than in intermediate-/high-risk categories (66 vs. 96 Ohm; P = 0.001). The PRAETORIAN score did not predict shock failure at 65 J. Conclusion In this cohort of S-ICD recipients, combining the two-incision technique and IM generator implantation yielded the lowest PRAETORIAN score values, indicating optimal defibrillation system position

Diagnostic investigation of 100 cases of abortion in sheep in Uruguay: 2015-2021.

Abstract: The aim of this work was to identify causes of abortion through laboratory investigations in sheep flocks in Uruguay. One hundred cases of abortion, comprising 58 fetuses, 36 fetuses with their placentas, and 6 placentas were investigated in 2015?2021. Cases were subjected to gross and microscopic pathologic examinations, and microbiological and serological testing for the identification of causes of abortion, including protozoal, bacterial, and viral pathogens. An etiologic diagnosis was determined in 46 (46%) cases, including 33 (33%) cases caused by infectious pathogens, as determined by the detection of a pathogen along with the identification of fetoplacental lesions attributable to the detected pathogen. Twenty-seven cases (27%) were caused by Toxoplasma gondii, 5 (5%) by Campylobacter fetus subspecies fetus, and 1 (1%) by an unidentified species of Campylobacter. Fourteen cases (14%) had inflammatory and/or necrotizing fetoplacental lesions compatible with an infectious etiology. Although the cause for these lesions was not clearly identified, T. gondii was detected in 4 of these cases, opportunistic bacteria (Bacillus licheniformis, Streptococcus sp.) were isolated in 2 cases, and bovine viral diarrhea virus 1 subtype i (BVDV-1i) was detected in another. Campylobacter jejuni was identified in 1 (1%) severely autolyzed, mummified fetus. BVDV-2b was identified incidentally in one fetus with an etiologic diagnosis of toxoplasmosis. Microscopic agglutination test revealed antibodies against ?1 Leptospira serovars in 15/63 (23.8%) fetuses; however, Leptospira was not identified by a combination of qPCR, culture, fluorescent antibody testing nor immunohistochemistry. Neospora caninum, Chlamydia abortus, Chlamydia pecorum, Coxiella burnetii and border disease virus were not detected in any of the analyzed cases. Death was attributed to dystocia in 13 (13%) fetuses delivered by 8 sheep, mostly from one highly prolific flock. Congenital malformations including inferior prognathism, a focal hepatic cyst, and enterohepatic agenesis were identified in one fetus each, the latter being the only one considered incompatible with postnatal life. Toxoplasmosis, campylobacteriosis and dystocia were the main identified causes of fetal losses. Despite the relatively low overall success rate in establishing an etiologic diagnosis, a systematic laboratory workup in cases of abortion is of value to identify their causes and enables zoonotic pathogens surveillance

Causas de aborto en ovinos de Uruguay: 100 casos, 2015-2021.

Este artículo se focaliza en la identificación d de causas de aborto en ovinos de diferentes departamentos del país, como aporte a la disminución de las pérdidas reproductivas, la mejora en el bienestar animal, y el diagnóstico de enfermedades zoonóticas