Influence of dose and route of administration on the outcome of infection with the virulent Neospora caninum isolate Nc-Spain7 in pregnant sheep at mid-gestation

Experimental infections in pregnant sheep have been focused on studying the effect of the time of challenge on the outcome of N. caninum infection, whereas the impact of the dose and route of challenge has not been studied in depth. Therefore, clinical outcome, immune responses, parasite detection and burden, and lesion severity in placental tissues and foetal brains were investigated in 90-day-pregnant sheep inoculated intravenously with 105 (G1), 104 (G2), 103 (G3), or 102 (G4) tachyzoites or subcutaneously with 104 (G5) tachyzoites of the virulent Nc-Spain7 isolate and an uninfected group (G6). Comparing challenge doses, G1 was the only group that had 100% abortion. Likewise, IFN¿ levels in G1 increased earlier than those in other intravenously infected groups, and IgG levels on day 21 post-infection (pi) were higher in G1 than those in other intravenously infected groups. Concerning vertical transmission, G1 shows a higher parasite burden in the foetal brain than did G2 and G3. Comparing routes of administration, no differences in foetal survival rate or parasite load in the foetal brain were found. Although G2 had higher IFN¿ levels than G5 on day 10 pi, no differences were found in humoral immune responses. Because the outcome after intravenous infection with 105 tachyzoites was similar to that observed after intravenous infection with 106 tachyzoites used in a previous work (100% abortion and vertical transmission), we conclude that it may be reasonable to use 105 tachyzoites administered by the intravenous route in further experiments when assessing drugs or vaccine candidates

Safety and efficacy of the bumped kinase inhibitor BKI-1553 in pregnant sheep experimentally infected with Neospora caninum tachyzoites

Neospora caninum is one of the main causes of abortion in cattle, and recent studies have highlighted its relevance as an abortifacient in small ruminants. Vaccines or drugs for the control of neosporosis are lacking. Bumped kinase inhibitors (BKIs), which are ATP-competitive inhibitors of calcium dependent protein kinase 1 (CDPK1), were shown to be highly efficacious against several apicomplexan parasites in vitro and in laboratory animal models. We here present the pharmacokinetics, safety and efficacy of BKI-1553 in pregnant ewes and foetuses using a pregnant sheep model of N. caninum infection. BKI-1553 showed exposure in pregnant ewes with trough concentrations of approximately 4 µM, and of 1 µM in foetuses. Subcutaneous BKI-1553 administration increased rectal temperatures shortly after treatment, and resulted in dermal nodules triggering a slight monocytosis after repeated doses at short intervals. BKI-1553 treatment decreased fever in infected pregnant ewes already after two applications, resulted in a 37–50% reduction in foetal mortality, and modulated immune responses; IFN¿ levels were increased early after infection and IgG levels were reduced subsequently. N. caninum was abundantly found in placental tissues; however, parasite detection in foetal brain tissue decreased from 94% in the infected/untreated group to 69–71% in the treated groups. In summary, BKI-1553 confers partial protection against abortion in a ruminant experimental model of N. caninum infection during pregnancy. In addition, reduced parasite detection, parasite load and lesions in foetal brains were observed

Influence of dose and route of administration on the outcome of infection with the virulent Neospora caninum isolate Nc-Spain7 in pregnant sheep at mid-gestation

15 páginas, 2 tablas, 7 figuras.Experimental infections in pregnant sheep have been focused on studying the effect of the time of challenge on the outcome of N. caninum infection, whereas the impact of the dose and route of challenge has not been studied in depth. Therefore, clinical outcome, immune responses, parasite detection and burden, and lesion severity in placental tissues and foetal brains were investigated in 90-day-pregnant sheep inoculated intravenously with 10(5) (G1), 10(4) (G2), 10(3) (G3), or 10(2) (G4) tachyzoites or subcutaneously with 10(4) (G5) tachyzoites of the virulent Nc-Spain7 isolate and an uninfected group (G6). Comparing challenge doses, G1 was the only group that had 100% abortion. Likewise, IFN gamma levels in G1 increased earlier than those in other intravenously infected groups, and IgG levels on day 21 post-infection (pi) were higher in G1 than those in other intravenously infected groups. Concerning vertical transmission, G1 shows a higher parasite burden in the foetal brain than did G2 and G3. Comparing routes of administration, no differences in foetal survival rate or parasite load in the foetal brain were found. Although G2 had higher IFN gamma levels than G5 on day 10 pi, no differences were found in humoral immune responses. Because the outcome after intravenous infection with 10(5) tachyzoites was similar to that observed after intravenous infection with 10(6) tachyzoites used in a previous work (100% abortion and vertical transmission), we conclude that it may be reasonable to use 10(5) tachyzoites administered by the intravenous route in further experiments when assessing drugs or vaccine candidates.We gratefully acknowledge Neus Callizo Esteve from Clinical Veterinary Hospital (Complutense University of Madrid, Spain) and Jose Maria Gonzalez (University of Zaragoza, Spain) for their excellent technical assistance. The Animal Experimentation Service (SEA) at the University of Zaragoza is acknowledged for using their facilities to carry out the reproduction programme. Roberto Sanchez Sanchez is supported by a fellowship from the Spanish Ministry of Education, Culture and Sports (MECD) as a part of the Programme of Training of University Teaching Staff (FPU, Grant Number FPU13/03438). This work was supported by the Ministry of Economy and Competitiveness (AGL2016-75935-C2) and Community of Madrid, Spain (PLATESA, S2013/ABI2906).Peer reviewe

Ultrasound-guided diagnostic breast biopsy methodology: retrospective comparison of the 8-gauge vacuum-assisted biopsy approach versus the spring-loaded 14-gauge core biopsy approach

<p>Abstract</p> <p>Background</p> <p>Ultrasound-guided diagnostic breast biopsy technology represents the current standard of care for the evaluation of indeterminate and suspicious lesions seen on diagnostic breast ultrasound. Yet, there remains much debate as to which particular method of ultrasound-guided diagnostic breast biopsy provides the most accurate and optimal diagnostic information. The aim of the current study was to compare and contrast the 8-gauge vacuum-assisted biopsy approach and the spring-loaded 14-gauge core biopsy approach.</p> <p>Methods</p> <p>A retrospective analysis was done of all ultrasound-guided diagnostic breast biopsy procedures performed by either the 8-gauge vacuum-assisted biopsy approach or the spring-loaded 14-gauge core biopsy approach by a single surgeon from July 2001 through June 2009.</p> <p>Results</p> <p>Among 1443 ultrasound-guided diagnostic breast biopsy procedures performed, 724 (50.2%) were by the 8-gauge vacuum-assisted biopsy technique and 719 (49.8%) were by the spring-loaded 14-gauge core biopsy technique. The total number of false negative cases (i.e., benign findings instead of invasive breast carcinoma) was significantly greater (P = 0.008) in the spring-loaded 14-gauge core biopsy group (8/681, 1.2%) as compared to in the 8-gauge vacuum-assisted biopsy group (0/652, 0%), with an overall false negative rate of 2.1% (8/386) for the spring-loaded 14-gauge core biopsy group as compared to 0% (0/148) for the 8-gauge vacuum-assisted biopsy group. Significantly more (P < 0.001) patients in the spring-loaded 14-gauge core biopsy group (81/719, 11.3%) than in the 8-gauge vacuum-assisted biopsy group (18/724, 2.5%) were recommended for further diagnostic surgical removal of additional tissue from the same anatomical site of the affected breast in an immediate fashion for indeterminate/inconclusive findings seen on the original ultrasound-guided diagnostic breast biopsy procedure. Significantly more (P < 0.001) patients in the spring-loaded 14-gauge core biopsy group (54/719, 7.5%) than in the 8-gauge vacuum-assisted biopsy group (9/724, 1.2%) personally requested further diagnostic surgical removal of additional tissue from the same anatomical site of the affected breast in an immediate fashion for a benign finding seen on the original ultrasound-guided diagnostic breast biopsy procedure.</p> <p>Conclusions</p> <p>In appropriately selected cases, the 8-gauge vacuum-assisted biopsy approach appears to be advantageous to the spring-loaded 14-gauge core biopsy approach for providing the most accurate and optimal diagnostic information.</p

Proper differentiation of photoreceptors and amacrine cells depends on a regulatory loop between NeuroD and Six6

Timely generation of distinct neural cell types in appropriate numbers is fundamental for the generation of a functional retina. In vertebrates, the transcription factor Six6 is initially expressed in multipotent retina progenitors and then becomes restricted to differentiated retinal ganglion and amacrine cells. How Six6 expression in the retina is controlled and what are its precise functions are still unclear. To address this issue, we used bioinformatic searches and transgenic approaches in medaka fish (Oryzias latipes) to characterise highly conserved regulatory enhancers responsible for Six6 expression. One of the enhancers drove gene expression in the differentiating and adult retina. A search for transcription factor binding sites, together with luciferase, ChIP assays and gain-of-function studies, indicated that NeuroD, a bHLH transcription factor, directly binds an 'E-box' sequence present in this enhancer and specifically regulates Six6 expression in the retina. NeuroD-induced Six6 overexpression in medaka embryos promoted unorganized retinal progenitor proliferation and, most notably, impaired photoreceptor differentiation, with no apparent changes in other retinal cell types. Conversely, Six6 gain- and loss-of-function changed NeuroD expression levels and altered the expression of the photoreceptor differentiation marker Rhodopsin. In addition, knockdown of Six6 interfered with amacrine cell generation. Together, these results indicate that Six6 and NeuroD control the expression of each other and their functions coordinate amacrine cell generation and photoreceptor terminal differentiation

Identification of molecular biomarkers associated with disease progression in the testis of bulls infected with Besnoitia besnoiti

18 páginas, 3 figuras, 4 tablas.Breeding bulls infected with Besnoitia besnoiti may develop sterility during either acute or chronic infection. The aim of this study was to investigate the molecular pathogenesis of B. besnoiti infection with prognosis value in bull sterility. Accordingly, fve well-characterized groups of naturally and experimentally infected males were selected for the study based on clinical signs and lesions compatible with B. besnoiti infection, serological results and parasite detection. A broad panel of molecular markers representative of endothelial activation and fbrosis was investigated and comple‑ mented with a histopathological approach that included conventional histology and immunohistochemistry. The results indicated the predominance of an intense infammatory infltrate composed mainly of resident and recruited circulating macrophages and to a lesser extent of CD3+cells in infected bulls. In addition, a few biomarkers were associated with acute, chronic or subclinical bovine besnoitiosis. The testicular parenchyma showed a higher number of diferentially expressed genes in natural infections (acute and chronic infections) versus scrotal skin in experimental infections (subclinical infection). In subclinical infections, most genes were downregulated except for the CCL24 and CXCL2 genes, which were upregulated. In contrast, the acute phase was mainly characterized by the upregulation of IL-1α, IL-6 and TIMP1, whereas in the chronic phase, the upregulation of ICAM and the downregulation of MMP13, PLAT and IL-1α were the most relevant fndings. Macrophages could be responsible for the highest level of gene regulation in the testicular parenchyma of severely afected and sterile bulls, and all these genes could be prognostic markers of sterility.This study was fnanced by the Spanish Ministry of Economy and Competi‑ tiveness (AGL-2016-75202-R), the Spanish Ministry of Science and Innovation (PID2019-103960RB-I00) and by the Community of Madrid (PLATESA P2018/ BAA-4370). DG-B was funded by the Spanish Ministry of Science through a Juan de la Cierva postdoctoral fellowship (FJCI-2016-27875). CD-D was fnancially supported through a grant from the Spanish Ministry of Economy and Competitiveness (BES-2014-069839) and AJ-M through a grant from the Spanish Ministry of Education, Culture and Sports (FPU, Grant Number FPU13/05481). I. Ferre, L.M. Ortega Mora y G. Álvarez-García are part of the TOXOSOURCES consortium, supported by funding from the European Union’s Horizon 2020 Research and Innovation programme under grant agreement No 773830: One Health European Joint Programme. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Vascular wall injury and inflammation are key pathogenic mechanisms responsible for early testicular degeneration during acute besnoitiosis in bulls

Background: Bovine besnoitiosis, caused by the apicomplexan parasite Besnoitia besnoiti, is a chronic and debilitating cattle disease that notably impairs fertility. Acutely infected bulls may develop respiratory signs and orchitis, and sterility has been reported in chronic infections. However, the pathogenesis of acute disease and its impact on reproductive function remain unknown. Methods: Herein, we studied the microscopic lesions as well as parasite presence and load in the testis (pampiniform plexus, testicular parenchyma and scrotal skin) of seven bulls with an acute B. besnoiti infection. Acute infection was confirmed by serological techniques (IgM seropositive results and IgG seronegative results) and subsequent parasite detection by PCR and histological techniques. Results: The most parasitized tissue was the scrotal skin. Moreover, the presence of tachyzoites, as shown by immunohistochemistry, was associated with vasculitis, and three bulls had already developed juvenile tissue cysts. In all animals, severe endothelial injury was evidenced by marked congestion, thrombosis, necrotizing vasculitis and angiogenesis, among others, in the pampiniform plexus, testicular parenchyma and scrotal skin. Vascular lesions coexisted with lesions characteristic of a chronic infection in the majority of bulls: Hyperkeratosis, acanthosis and a marked diffuse fibroplasia in the dermis of the scrotum. An intense inflammatory infiltrate was also observed in the testicular parenchyma accompanied by different degrees of germline atrophy in the seminiferous tubules with the disappearance of various strata of germ cells in four bulls. Conclusions: This study confirmed that severe acute besnoitiosis leads to early sterility that might be permanent, which is supported by the severe lesions observed. Consequently, we hypothesized that testicular degeneration might be a consequence of (i) thermoregulation failure induced by vascular lesions in pampiniform plexus and scrotal skin lesions; (ii) severe vascular wall injury induced by the inflammatory response in the testis; and (iii) blood-testis barrier damage and alteration of spermatogenesis by immunoresponse.[Figure not available: See fulltext.

Dose-titration of virulent Neospora caninum isolate Nc-Spain7 in pregnant sheep at 90 days of gestation

Trabajo presentado al: 4th International Meeting on Apicomplexa in Farm Animals. (Madrid, Spain. 11-14 October 2017).Neospora caninum is considered one of the main causes of abortion in cattle and recent studies showed its relevance as abortifacient in small ruminants. Recently, the well-characterized NcSpain7 isolate has been tested in a pregnant sheep model of Neospora infection at mid gestation (90 days of gestation) using 106 tachyzoites intravenously and resulting in 100% abortion and highly parasite detection in target fetal tissues. This isolate has also been titrated in a pregnant mice model suggesting that a dose of 105 tachyzoites would be suitable for testing drugs or vaccine candidates. Thus, a refinement and standardization of the pregnant sheep model of neosporosis is also recommendable. Whit this purpose, pregnant sheep were inoculated intravenously at 90 days of gestation with 105 (n=6) (G1), 104 (n=5) (G2), 103 (n=5) (G4), 102 (n=4) (G5) tachyzoites; and subcutaneously with 104 tachyzoites (n=4) (G3) of the Nc-Spain7 or with PBS (n=3) (G6). Clinical outcome and lesions, parasite detection, parasite burden in target tissues and humoral and cellular immune responses were evaluated. Fetal mortality was detected between 32-44 days post infection in G1 (6 out of 6 pregnant ewes), G2 (4 out of 5 pregnant ewes), G3 (3 out of 4 pregnant ewes), G4 (3 out of 5 pregnant ewes), and G5 (2 out of 4 pregnant ewes). Pregnant sheep in G6 gave birth to healthy lambs. Significant differences were found in the fetal survival rate between G1 and G6 (P < 0.05). Serological analysis showed IFAT titers higher than 1:32 and 1:200 in thoracic liquid of all aborted fetuses and precolostral sera of all lambs, respectively. N. caninum DNA was widely detected in placentomes/cotyledons investigated from all animals in the different infected groups. In fetal brain, parasite DNA was detected in 81.8%, 91.7%, 87.5%, 66.7% and 90.5% of samples examined in G1, G2, G3, G4 and G5 respectively. Significant lower parasite detection was found in G4 compared to G2 (P < 0.05). Parasite load in fetal brain was lower in G2 (P < 0.05) and G4 (P < 0.001) compared to G1 and G5. In addition, G4 showed lower brain parasite burden compared to G2 (P < 0.05). In conclusion, clear differences were observed concerning abortion between pregnant sheep inoculated with different parasite doses while less pronounced differences related to vertical transmission to the fetus were found between doses or routes of administration.Funded by Ministry of Economy and Competitiveness (AGL2016-75935-C2). Roberto Sánchez-Sánchez was financially supported by a Spanish Ministry of Education, Culture and Sports grant (FPU13/03438). Also, Animal Experimentation Service at University of Zaragoza is acknowledged for carry out reproduction programme.Peer reviewe

Pharmacokinetics, safety and efficacy of Bumped Kinase Inhibitor (BKI) 1553 in a pregnant sheep model of neosporosis

1 página.-- Trabajo presentado al: 4th International Meeting on Apicomplexa in Farm Animals. (Madrid, Spain. 11-14 October ,2017).Funded by NIH (4180015), USDA (4180014) and Community of Madrid (S2013/ABI2906) research projects.Peer Reviewe