Draft Genome Sequences of Mexican Babesia bovis Virulent and Attenuated Strains.

Babesia bovis, a tick-borne intraerythrocytic protozoan parasite that belongs to the phylum Apicomplexa, is one of the etiological agents of bovine babesiosis, a highly prevalent disease in tropical and subtropical countries that causes significant morbidity and deaths in cattle. This report presents the draft genome sequences of attenuated and virulent B. bovis strains of Mexican origin.

Retinocytoma/retinoma: comparative analysis of clinical features in 78 tumors and rate of transformation into retinoblastoma over 20 years.

PURPOSE: To explore clinical features and long-term outcomes in patients with retinocytoma/retinoma. METHODS: The medical records of patients with retinocytoma/retinoma over a 20-year period were reviewed retrospectively to compare patient age at presentation (<4 vs ≥4 years), tumor type, and tumor focality (unifocal vs multifocal). RESULTS: Of 2,021 patients with retinoblastoma, 62 (3%; median age, 5 years; 85% white; 58% male) had 78 tumors: 54 retinocytoma (69%) and 24 retinoma (31%). Median basal tumor diameter was 6.0 mm; mean thickness, 2.3 mm. Younger patients (<4 years) were more likely Hispanic (19% vs 2%; P = 0.04), with leukocoria (24% vs 0%; P = 0.003), and with calcification in ≤50% of the tumor (96% vs 70%; P = 0.007). Compared with retinoma, retinocytoma was more prevalent in older patients (median age, 9 vs 2 years; P < 0.001), with fewer symptoms (38% vs 69%; P = 0.04), larger median basal diameter (7.0 vs 3.0 mm; P < 0.001), greater thickness (2.5 vs 1.6 mm; P = 0.02), and less frequently with additional retinoblastoma in either eye (9% vs 71%; P < 0.0001). Compared with multifocal tumors, unifocal tumors occurred more frequently with lack of symptoms (62% vs 25%; P = 0.03), greater median basal diameter (6.0 vs 3.3; P = 0.003), and greater thickness (2.5 vs 1.5 mm; P = 0.006). Tumor transformation into retinoblastoma was found in 2.7% by 2 years, 9.2% by 5 years, 15.3% by 10-20 years. The only factor predictive of transformation was increasing thickness (P = 0.003; hazard ratio of 2.83 per 1 mm increase). CONCLUSIONS: In our study cohort, the rate of retinocytoma/retinoma transformation into retinoblastoma increased from 2 to 10-20 years of age. The only factor predictive of transformation was increasing tumor thickness.

A Comparative Genomic Study of Attenuated and Virulent Strains of Babesia bigemina.

Cattle babesiosis is a socio-economically important tick-borne disease caused by Apicomplexa protozoa of the genus Babesia that are obligate intraerythrocytic parasites. The pathogenicity of Babesia parasites for cattle is determined by the interaction with the host immune system and the presence of the parasite's virulence genes. A Babesia bigemina strain that has been maintained under a microaerophilic stationary phase in in vitro culture conditions for several years in the laboratory lost virulence for the bovine host and the capacity for being transmitted by the tick vector. In this study, we compared the virulome of the in vitro culture attenuated Babesia bigemina strain (S) and the virulent tick transmitted parental Mexican B. bigemina strain (M). Preliminary results obtained by using the Basic Local Alignment Search Tool (BLAST) showed that out of 27 virulence genes described and analyzed in the B. bigemina virulent tick transmitted strain, only five were fully identified in the attenuated laboratory strain. In all cases, the identity and coverture of the identified genes of the wildtype strain were higher than those of the laboratory strain. This finding is putatively associated with the continuous partial loss of virulence genes in the laboratory strain after several passages of the parasite population under optimal in vitro growth conditions. The loss of virulence factors might be reflected in the absence of symptoms of the disease in cattle inoculated with the attenuated strain despite the presence of infection in the bovine host cells.

An Overview of Current Knowledge on in vitro Babesia Cultivation for Production of Live Attenuated Vaccines for Bovine Babesiosis in Mexico.

The instrumentation of the in vitro culture system has allowed researchers to learn more about the metabolic and growth behavior of Babesia spp. The various applications for in vitro cultivation of Babesia include obtaining attenuated strains for vaccination or pre-munition, the selection of pure lines with different degrees of virulence, studies on biological cloning, ultrastructure, antigen production for diagnostics, drug sensitivity assessments, and different aspects of parasite biology. Although there are different types of vaccines that have been tested against bovine babesiosis, so far, the only procedure that has offered favorable results in terms of protection and safety has been the use of live attenuated vaccines. In countries, such as Australia, Argentina, Brazil, Uruguay and Israel, this type of vaccine has been produced and used. The alternative to live vaccines other than splenectomized calf-derived biological material, has been the in vitro cultivation of Babesia bovis and B. bigemina. The development of in vitro culture of Babesia spp. strains in a defined medium has been the basis for the initiation of a source of parasites and exoantigens for a variety of studies on the biochemistry and immunology of babesiosis. The use of live immunogens from attenuated strains derived from in vitro culture is highlighted, which has been proposed as an alternative to control bovine babesiosis. In several studies performed in Mexico, this type of immunogen applied to susceptible cattle has shown the induction of protection against the experimental heterologous strain challenge with both, Babesia-infected blood and animal exposure to confrontations on tick vector-infested farms. The combination of transfection technologies and the in vitro culture system as integrated methodologies would eventually give rise to the generation of genetically modified live vaccines. However, a greater challenge faced now by researchers is the large-scale cultivation of Babesia parasites for mass production and vaccine distribution.

Adenoma and Adenocarcinoma of the Retinal Pigment Epithelium: A Review of 51 Consecutive Patients.

PURPOSE: To describe the clinical and imaging characteristics, pathologic features, and management options of retinal pigment epithelium (RPE) adenoma/adenocarcinoma. DESIGN: Retrospective case series. PARTICIPANTS: Fifty-one patients with RPE adenoma/adenocarcinoma. METHODS: Treatment options for the patients included observation, partial lamellar sclerouvectomy (PLSU), enucleation, and others. MAIN OUTCOME MEASURES: Factors related to visual acuity (VA) outcomes (>2 Snellen lines loss, poor final VA [≤20/200], good final vision [≥20/40]), tumor growth, and need for enucleation. RESULTS: The mean patient age at diagnosis was 51 years, and the majority of patients were white (40/51, 78%) and female (34/51, 67%). Primary management included observation (29/51, 57%), PLSU (9/51, 18%), enucleation (4/51, 8%), or others (9/51, 18%). Outcomes revealed decreased VA (10/32, 31%), poor final VA (17/32, 53%), good final VA (11/32, 34%), tumor growth (12/25, 48%), and need for enucleation (7/51, 14%). By multivariable analysis, features predictive of decreased VA included increasing baseline tumor thickness (P = 0.01) and presence of vitreous hemorrhage (P = 0.05). Factors predictive of poor final VA included presence of exudative retinal detachment (P = 0.004), baseline VA 20/50 to 20/150 (P = 0.008), and baseline VA ≤20/200 (P = 0.01). Absence of feeding and/or draining vessel was predictive of good VA (P = 0.004). Tumor growth was associated with multiple treatments (P = 0.02). Increased tumor thickness (P = 0.03) and presence of exudative retinal detachment (P = 0.01) were predictive of enucleation. CONCLUSION: RPE adenoma/adenocarcinoma can simulate choroidal melanoma. Greater tumor thickness, vitreous hemorrhage, exudative retinal detachment, and poor baseline VA predict worse visual outcome and greater risk for enucleation.

Choroidal Melanoma Simulating Adenoma of the Retinal Pigment Epithelium Arising at the Site of Congenital Hypertrophy of the Retinal Pigment Epithelium.

Neoplasms of the retinal pigment epithelium (RPE) are rare tumors that can simulate choroidal melanoma, but clinical and imaging characteristics often differentiate these lesions. We report a 70-year-old male with an abruptly elevated pigmented lesion that arose at the site of congenital hypertrophy of the RPE and demonstrated associated exudation, as well as feeding and draining vessels, suggestive of RPE adenoma. Optical coherence tomography showed retinal elevation with serous retinal detachment adjacent to the mass, and ultrasonography revealed an abruptly elevated, moderately echodense mass of 6.4-mm thickness. Fluorescein -angiography showed early tumor hypofluorescence, late -tumor hyperfluorescence with staining and leakage, and -retinal vessels buried under the mass, suggestive of a retinal tumor. The patient was monitored with the presumed diagnosis of RPE adenoma, but 3 months later, the growth was documented and fine-needle aspiration biopsy revealed choroidal melanoma. Management with I-125 plaque radiotherapy was performed leading to tumor regression and a thickness of 4.6 mm.

Diagnostic Tools for the Identification of Babesia sp. in Persistently Infected Cattle.

Bovine babesiosis is a tick-borne disease of cattle caused by the protozoan parasites of the genus Babesia. Babesia bovis, Babesia bigemina and Babesia divergens are considered by International health authorities (OIE) as the principal species of Babesia that cause bovine babesiosis. Animals that recover from a babesial primo infection may remain as persistent carriers with no clinical signs of disease and can be the source of infection for ticks that are able to acquire Babesia parasites from infected cattle and to transmit Babesia parasites to susceptible cattle. Several procedures that have been developed for parasite detection and diagnosis of this infectious carrier state constitute the basis for this review: A brief description of the direct microscopic detection of Babesia-infected erytrocytes; PCR-based diagnostic assays, which are very sensitive particularly in detecting Babesia in carrier cattle; in-vitro culture methods, used to demonstrate presence of carrier infections of Babesia sp.; animal inoculation, particularly for B. divergens isolation are discussed. Alternatively, persistently infected animals can be tested for specific antibabesial antibodies by using indirect serological assays. Serological procedures are not necessarily consistent in identifying persistently infected animals and have the disadvantage of presenting with cross reactions between antibodies to Babesia sp.

Choroidal Ischemia Sparing the Watershed Zone following Intra-Arterial Chemotherapy for Retinoblastoma.

PURPOSE: Intra-arterial chemotherapy (IAC) has become a mainstay in the management of retinoblastoma, especially in advanced or refractory disease. However, IAC is not without complications, and chemotherapy toxic effects can lead to partial or complete choroidal ischemia, often causing vision loss. METHODS: This is a case report. RESULTS: A 4-month-old girl with bilateral retinoblastoma was treated with secondary IAC (melphalan 5 mg) for recurrent tumor following intravenous chemotherapy. One month later, complete tumor control was achieved. However, she demonstrated broad choroidal ischemia in the nasal and temporal quadrants but sparing of the watershed zone superior and inferior to the optic disc and in the papillomacular region. Fluorescein angiography revealed poor perfusion of the choriocapillaris with visibility of the large choroidal vessels in the nasal and temporal areas but preserved perfusion of the watershed zone. The watershed zone remained intact on the 10-month follow-up, and the final visual acuity was fix and follow without strabismus. CONCLUSION: The pathophysiology of choroidal ischemia is not well understood, but the fortuitous watershed zone preservation in this case could represent uneven distribution of the chemotherapeutic drug, resulting in partial chemo-dilution of the medication in the watershed region, which represents the final downstream overlapping choroidal perfusion from both medial and lateral posterior ciliary arteries.

Primary Intra-Arterial Chemotherapy for Retinoblastoma in the Intravitreal Chemotherapy Era: Five Years of Experience.

PURPOSE: To report our 5-year experience with intra-arterial chemotherapy (IAC) in the intravitreal chemotherapy (IvitC) era. METHODS: Retrospective review of retinoblastoma treated with primary unilateral IAC in the IvitC era (2012-2017). RESULTS: There were 34 eyes treated with IAC alone versus 20 eyes treated with IAC plus IvitC for vitreous seeds. IAC (IAC alone vs. IAC plus IvitC) consisted of melphalan (41 vs. 10%) or melphalan plus topotecan (59 vs. 90%, p = 0.03). IvitC consisted of melphalan (60%) or melphalan plus topotecan (40%). Tumor control and globe salvage were achieved in 100% of group B and C eyes without IvitC. Despite more extensive vitreous seeds in the IvitC group (p < 0.01), comparison of IAC alone versus IAC plus IvitC revealed no difference in tumor control for group D (88 vs. 69%, p = 0.36) or group E (67 vs. 100%, p = 0.25) and no difference in globe salvage for group D (88 vs. 69%, p = 0.36) or group E (58 vs. 57%, p = 0.39). CONCLUSIONS: IAC is effective as primary therapy for unilateral group B, C, D, and E retinoblastoma. IvitC is an important adjuvant therapy to achieve comparable globe salvage rates for group D and E eyes with persistent active vitreous seeds.

CHOROIDAL NEVUS TRANSFORMATION INTO MELANOMA PER MILLIMETER INCREMENT IN THICKNESS USING MULTIMODAL IMAGING IN 2355 CASES: The 2019 Wendell L. Hughes Lecture.

PURPOSE: To analyze risk of nevus transformation into melanoma per millimeter increment. METHODS: Retrospective analysis of 3,806 choroidal nevi for transformation into melanoma per incremental millimeter thickness (flat [≤1.0 mm], thin [1.1-2.0 mm], thicker [2.1-3.0 mm], and thickest [>3.0 mm]) RESULTS:: The median nevus thickness was 1.4 mm, and nevi were categorized (flat, thin, thicker, and thickest) in 1,140 (30%), 2052 (54%), 555 (15%), and 59 (<1%), respectively. There were differences in tumor diameter (2.5, 4.8, 7.5, and 9.3 mm; P < 0.01), optical coherence tomography detection of overlying subretinal fluid (<1, 4, 15, and 11%; P < 0.01), overlying retinal edema (<1, 3, 14, and 25%; P < 0.01), overlying drusen (23, 49, 64, and 64%; P < 0.01), overlying retinal pigment epithelial detachment (1, 4, 4, and 9%; P < 0.01), and overlying lipofuscin hyperautofluoresence (<1, 3, 6, and 7%; P < 0.01). Choroidal nevus transformation into melanoma (n = 90/2,355 cases, 3.8%) was found by Kaplan-Meier 7-year estimates (2.2, 6.1, 31.7, and 34.5%; P < 0.0001) and by hazard ratio (HR) compared with nevus ≤1.0 mm (not available, 4.7 [P = 0.01], 35.7 [P < 0.0001], and 52.0 [P < 0.0001]). For all thicknesses, those with growth displayed increase in mean basal diameter of 2.4 mm and thickness of 1.1 mm, optical coherence tomography increase in subretinal fluid (65%), autofluorescence increase in lipofuscin (40%), and ultrasonography increase in hollowness (30%). Multivariable risk factors, recalled by the mnemonic "To Find Small Ocular Melanoma Doing IMaging" (TFSOM-DIM) representing Thickness >2 mm (ultrasonography), Fluid subretinal (optical coherence tomography), Symptom vision loss (Va), Orange pigment (autofluorescence), Melanoma hollow (ultrasonography), and DIaMeter >5 mm, revealed factors per incremental thickness category (compared with flat) including thin (Fluid overlying, HR 6.1; DIaMeter >5 mm, HR 3.3), thicker (Fluid subretinal ≤3 mm from nevus, HR 5.7; Melanoma acoustic hollowness, HR 2.7), and thickest (Orange pigment, HR 9.1). CONCLUSION: Each incremental increase in choroidal nevus thickness demonstrated risk of growth into melanoma with HR (compared with flat) 4.7 for thin, 35.7 for thicker, and 52.0 for thickest. The increase from ≤2.0 mm to >2.0 mm thickness conferred the greatest rise for transformation.

CHOROIDAL NEVUS IMAGING FEATURES IN 3,806 CASES AND RISK FACTORS FOR TRANSFORMATION INTO MELANOMA IN 2,355 CASES: The 2020 Taylor R. Smith and Victor T. Curtin Lecture.

PURPOSE: To use multimodal imaging for identification of risk factors for choroidal nevus transformation into melanoma. METHODS: Retrospective chart review of 3806 consecutive choroidal nevi with imaging and 2355 choroidal nevi with additional follow up to identify factors predictive of transformation of choroidal nevus into melanoma. RESULTS: The median patient age was 62.5 years and Caucasian race in 3167 (95%). The choroidal nevus demonstrated median basal diameter of 4.0 mm and thickness of 1.4 mm. Imaging included optical coherence tomography (OCT) showing subretinal fluid (SRF) in 312 (9%), ultrasonography (US) with acoustic hollowness in 309 (9%), and hyper-autofluorescence (AF) in 100 (3%). Of those 2355 choroidal nevi with follow up, Kaplan-Meier estimates of nevus transformation into melanoma at 1, 5, and 10 years were 1.2%, 5.8%, and 13.9%, respectively. Multivariate analysis, using multimodal imaging for detection of factors predictive of nevus transformation into melanoma, included thickness >2 mm on US (hazard ratio (HR) 3.80, p < 0.0001), SRF on OCT as cap over nevus (HR 3.00, p < 0.0001) or SRF ≤3 mm from nevus margin (HR 3.56, p = 0.0003), symptomatic vision loss ≤20/50 on Snellen visual acuity (VA) (HR 2.28, p = 0.005), orange pigment (lipofuscin) hyperautofluorescence on AF (HR 3.07, p = 0.0004), acoustic hollowness on US (HR 2.10, p = 0.0020), and tumor diameter >5 mm on photography (HR 1.84, p = 0.0275). These factors can be recalled by the mnemonic "To Find Small Ocular Melanoma Doing IMaging" (TFSOM-DIM) representing Thickness >2 mm (US), Fluid subretinal (OCT), Symptoms vision loss (VA), Orange pigment (AF), Melanoma hollow (US), and DIaMeter >5mm (photography). The mean 5-year estimates of nevus growth into melanoma were 1% (HR 0.8) for those with 0 risk factor, 11% (HR 3.09) with 1 factor, 22% (HR 10.6) with 2 factors, 34% (HR 15.1) with 3 factors, 51% (HR 15.2) with 4 factors, 55% (HR 26.4) with 5 risk factors, and not-estimable with all 6 risk factors. CONCLUSION: In this analysis, multimodal imaging was capable of detecting risk factors for nevus transformation into melanoma, including thickness >2 mm (US), fluid subretinal (OCT), symptoms vision loss (Snellen acuity), orange pigment (AF), melanoma hollowness (US), and diameter >5 mm (photography). Increasing number of risk factors imparts greater risk for nevus transformation into melanoma, including thickness >2 mm (US), fluid subretinal (OCT), symptoms vision loss (Snellen acuity), orange pigment (AF), melanoma hollowness (US), and diameter >5 mm (photography). Increasing number of risk factors imparts greater risk for transformation.

OPHTHALMIC VASCULAR EVENTS AFTER INTRA-ARTERIAL CHEMOTHERAPY FOR RETINOBLASTOMA: Real-World Comparison Between Primary and Secondary Treatments.

PURPOSE: To determine whether treatment order affects ophthalmic vascular event rates after intra-arterial chemotherapy (IAC) for retinoblastoma. METHODS: Patients who received IAC as primary or secondary treatment for retinoblastoma from January 2009 to January 2018 were included. All eyes were imaged with fundus photography and fluorescein angiography. Patient characteristics and vascular event rates were compared using t-test and Fisher's exact test. RESULTS: There were 196 patients treated with 682 infusions of IAC, divided into primary (no previous therapy, 98 eyes of 98 patients, 328 infusions) and secondary (after other therapy, 105 eyes of 98 patients, 354 infusions) treatment. Overall, ophthalmic vascular events were found after 5% of infusions (17% eyes). A comparison of ophthalmic vascular events (primary vs. secondary IAC), with mean three infusions per eye (median 3, range 1-7), revealed no difference in overall percentage of eyes affected (18% vs. 15%, P = 0.57). Adverse vascular events per eye included retinal vasculature attenuation (1% vs. 0%, P = 0.99), peripheral retinal pruning (1% vs. 0%, P = 0.99), branch retinal artery occlusion (0% vs. 1%, P = 0.99), central retinal artery occlusion (0% vs. 1%, P = 0.99), macular ischemia (0% vs. 2%, P = 0.51), vitreous hemorrhage (2% vs. 3%, P = 0.92), subretinal hemorrhage (1% vs. 0%, P = 0.99), retinal pigment epithelium atrophy (6% vs. 3% P = 0.43), choroidal atrophy (4% vs. 2%, P = 0.92), optic disk pallor (1% vs. 0%, P = 0.99), and ophthalmic artery occlusion (9% vs. 6%, P = 0.35). CONCLUSION: Ophthalmic vascular events after IAC for retinoblastoma affect only 5% of eyes per infusion (17% of treated eyes). Vascular event risk per eye is similar when using IAC as primary or secondary treatment.

Combination of multimodal imaging features predictive of choroidal nevus transformation into melanoma.

AIM: To characterise combinations of multimodal imaging risk factors and predictive value for choroidal nevus transformation into melanoma. METHODS: This is a retrospective review of multimodal imaging features for 3806 choroidal nevi from 1 January 2007 through 1 January 2017. Kaplan-Meier estimates and Cox regression analyses were used to calculate 5-year percentages of growth to melanoma and HR. RESULTS: Using multimodal imaging, six risk factors predictive of choroidal nevus transformation into melanoma were identified, namely tumour thickness >2 mm, subretinal fluid, symptoms of visual acuity loss to 20/50 or worse, orange pigment, hollow acoustic density and tumour largest basal diameter >5 mm. Kaplan-Meier 5-year estimated tumour growth was found in 1% of nevi with no risk factors, 11% (range 9%-37%) with one factor, 22% (12%-68%) with two factors, 34% (21%-100%) with three factors, 51% (0%-100%) with four factors and 55% (0%-100%) with five factors. HR for growth was 0.1 with no factor, 2.1-7.8 with one factor, 1.8-12.1 with two factors, 4.0-24.4 with three factors, 4.6-170.0 with four factors and 12.0-595.0 with five factors. The highest HR with each combination of two, three, four or five risk factors always included symptoms of visual acuity loss and orange pigment. CONCLUSION: Six risk factors for choroidal nevus transformation into melanoma by multimodal imaging have been identified. Risk for transformation into melanoma is 1% when no factors are present, and approaches 100% with specific combinations of three or more risk factors. Understanding how combinations of factors influence risk of transformation into melanoma can guide counselling and treatment decisions.

Ophthalmic Vascular Events after Primary Unilateral Intra-arterial Chemotherapy for Retinoblastoma in Early and Recent Eras.

PURPOSE: To assess risk factors for ophthalmic vascular events after intra-arterial chemotherapy (IAC) for retinoblastoma. DESIGN: Retrospective cohort study. PARTICIPANTS: Patients who received unilateral IAC as primary treatment for retinoblastoma from January 1, 2009, to November 30, 2017, at a single center. METHODS: Records were reviewed for patient demographics, tumor features, IAC parameters, and treatment-related vascular events in the early IAC era (2009-2011) compared with the recent era (2012-2017) using the t test and Fisher exact test. Change in event rates over time was assessed using Poisson regression analysis, with Spearman's rho used to test correlation. MAIN OUTCOME MEASURES: Rate of IAC-induced ophthalmic vascular events. RESULTS: There were 243 chemotherapy infusions in 76 eyes of 76 patients, divided into early (22 eyes, 57 infusions) and recent (54 eyes, 186 infusions) eras. Intra-arterial chemotherapy consisted of melphalan (243 infusions), topotecan (124 infusions), and carboplatin (9 infusions). A comparison (early vs. recent era) revealed fewer mean number of infusions (2.6 vs. 3.4, P = 0.02) with similar mean patient age and presenting tumor features. Event rates decreased over time (P < 0.01), with fewer ophthalmic vascular events (early era vs. recent era) in the recent era (59% vs. 9% per eye, 23% vs. 3% per infusion, P < 0.01), including peripheral retinal nonperfusion (5% vs. 2% per eye, P = 0.50), vitreous hemorrhage (9% vs. 2%, P = 0.20), subretinal hemorrhage (0% vs. 2%, P = 0.99), branch retinal vein occlusion (5% vs. 0%, P = 0.29), choroidal ischemia (14% vs. 4%, P = 0.14), and ophthalmic artery spasm/occlusion (27% vs. 0%, P < 0.01). Events did not correlate to patient age (P = 0.75), tumor diameter (P = 0.32), tumor thickness (P = 0.59), or cumulative dosage of melphalan (P = 0.13) or topotecan (P = 0.59). There were no IAC-induced vascular events in 72 infusions of 21 consecutively treated eyes in 2016 to 2017. CONCLUSIONS: Ophthalmic vascular events after IAC have decreased from the early era (2009-2011) through the current era (2012-2017) at this center. Experience performing this highly specialized procedure could be an important factor predicting IAC-related vascular events.

Infection and seroconversion of susceptible animals introduced into a babesiosis endemic area.

The study aimed to determine the incubation period of Babesia sp. infection in naive cattle and to monitor the serological response once exposed to natural Boophilus microplus (Rhipicephalus microplus)-infested paddocks. The study was carried out on a farm located in Veracruz, Mexico. Five groups of five steers were relocated every 3 months from a tick-free area to a tick-infested paddock. Animals were introduced in October, January, April, July, and October. Blood samples were taken daily until day 21 to determine packed cell volume (PCV), percentage of parasitized erythrocytes (PPE), and antibody titers to Babesia bigemina and B. bovis by the indirect fluorescent antibody procedure. Detection of Babesia in blood was also performed by species-specific PCR. The estimated incubation period was 6-14 days post introduction to paddocks (PIP), with fever (41 degrees C) for at least 3 days. PCV decreased by >25% and Babesia parasites were observed during the clinical phase of the disease. The highest individual PPEs (0.44% and 0.22% for B. bovis and B. bigemina, respectively) were observed from animals introduced in October. The four other groups showed a mean PPE ranging from 0.002-0.146% at day 14 PIP. All animals were detected as PCR positive between 8-14 days PIP. The highest antibody titers were 1:3328. The environmental conditions were favorable throughout the year for tick reproduction as the farm showed enzootic stability and hyperendemic conditions for bovine babesiosis. In this type of farm, strategic tick control could be accompanied by babesiosis vaccination, particularly for cattle relocated from tick-free areas.

msa-1 and msa-2c gene analysis and common epitopes assessment in Mexican Babesia bovis isolates.

Babesia bovis msa-1 and msa-2c genes belong to the variable merozoite surface antigen gene family. These genes code for antigenic proteins present on the merozoite surface (MSA) and are involved in the parasite invasion to the bovine erythrocyte. Previous studies carried out on MSA-1 have evidenced antigen allelic variation in B. bovis isolates from similar endemic regions, as well as in isolates from different geographic regions of the world (Argentina, Australia, Israel). Studies conducted on MSA-2c, however, have shown that this antigen is widely conserved on isolates from distinct geographic regions. In this study, it was hypothesized that MSA-1 and MSA-2c antigens would contain common epitopes despite the presence of nucleotide sequence differences found in 13 B. bovis isolates and strains collected in geographically distant regions of Mexico. Bioinformatics analysis of the primary structure from DNA fragments derived from PCR amplification, cloning, and sequencing of msa-1 and msa-2c genes from the 13 B. bovis populations revealed that the msa-1 gene product present in the various isolates tested is less conserved among isolates obtained within a similar geographic region in Mexico (51-99.7% sequence identity). Results obtained by immunoblot analysis of B. bovis protein extracts reacted with a monoclonal antibody to MSA-1 42-kDa antigen, conclusively showed cross-reactive common epitopes only in Mexican isolates having high sequence identity (>/=99%, eight isolates). Sequence analysis and multiple alignment of deduced MSA-2c demonstrated a high degree of sequence identity (90-100%) among the Mexican B. bovis isolates and strains. Immunoblot results using a polyclonal antibody to MSA-2c reacted against the protein extracts recognized conserved epitopes in at least nine of the B. bovis isolates. The results obtained in this study agree with those previously reported by other researchers and confirm that, based in sequence identity conservation in Mexican B. bovis isolates and strains so far collected and analyzed, MSA-2c represents an ideal antigen worth evaluating as a vaccine candidate.

Evaluation of cattle inoculated with Babesia bovis clones adhesive in vitro to bovine brain endothelial cells.

A comparative assessment of the virulence of Babesia bovis clones that adhere or not to bovine brain endothelial cells was done using two clones of B. bovis: (1) a clone phenotypically characterized as virulent (2F8) and (2) a clone of reduced virulence (RAD). Of these subpopulations, we selected those that had adhesive characteristics (a) or nonadhesive characteristics (na) in cultured endothelial cells. Twenty Holstein cattle, 12 months of age or older, were used in this study, and these cattle were randomly assigned to five groups of four animals each. The clones and their respective subpopulations were inoculated via intramuscular injection at a 0.5 x 10(7) infected erythrocyte dosage. Group A was inoculated with aRAD, group B with naRAD, group C with a2F8, group D with na2F8, and group E remained as a control. All inoculated animals showed a decrease in the packed cell volume (PCV), with group D showing the largest decrease (39.53%) and longest time (7 days) with rectal temperature above 39.5 degrees C. Babesia was observed in stained blood smears from only six cattle. While the four parasite subpopulations were pathogenic, significant differences were not noted among them, despite that the subpopulations considered to be virulent caused the greatest reduction in PCV per individual.

Factores predictivos de malignidad en microcalcificaciones de mama sin lesiones asociadas / Predictive factors for malignancy in breast microcalcifications without associated lesions

Introducción. El cribado mamográfico de cáncer de mama permite la detección y el tratamiento temprano de los carcinomas no palpables. Las microcalcificaciones son un hallazgo mamográfico muy importante para la detección de muchos de estos procesos, pero también están presentes en enfermedad benigna de la mama. En este estudio se analizan los factores clínicos y radiológicos que tienen valor predictivo de malignidad. Material y métodos. Se han recogido retrospectivamente 133 casos de biopsias abiertas realizadas a pacientes con hallazgo mamográfico de microcalcificaciones sin lesión asociada. Las características clínicas y radiológicas se correlacionaron con los hallazgos histológicos. Resultados. El 28,6% de las lesiones analizadas fueron malignas, y entre ellas el 65,8% fueron carcinomas ductales in situ. Un 23,1% de los carcinomas infiltrantes presentaron adenopatías positivas. Ningún factor clínico tuvo valor predictivo de malignidad. En el estudio univariante, los factores radiológicos que presentaron significación estadística fueron: el tipo morfológico, según la clasificación de Le Gal, la irregularidad en el tamaño, la irregularidad en la densidad, el número de microcalcificaciones por grupo, el diámetro de la lesión y la presencia de más de un foco de microcalcificaciones. En el estudio multivariante, los factores con valor predictivo independiente fueron: la irregularidad en la densidad, la concentración ≥ 10 microcalcificaciones por grupo, la presencia de más de un foco de microcalcificaciones y el diámetro de la lesión ≥ 10mm. Conclusiones. Aunque ningún factor clínico fue relevante en la predicción de malignidad, las características radiológicas de las microcalcificaciones fueron determinantes en la indicación de una biopsia (AU)

Introduction. Screening mammography allows the early detection and treatment of nonpalpable carcinomas. Microcalcifications are highly important for the detection of many of these malignancies but are also present in benign breast disease. In the present study we analyzed the radiologic and clinical factors associated with malignancy. Material and methods. We retrospectively reviewed 133 patients who underwent open biopsy after a mammographic finding of microcalcifications without an associated lesion. Clinical and radiologic characteristics were correlated with histologic findings. Results. A total of 28.6% of the lesions analyzed were malignant. Of these, 65.8% were ductal carcinoma in situ. Among invasive carcinomas, 23.1% presented lymph node metastasis. No clinical criterion was significant for malignancy. On univariate analysis six radiologic criteria were significant: morphologic type (Le Gal's classification), irregularity of size, irregularity of density, number of microcalcifications per cluster, diameter of the lesion, and the presence of more than one cluster. On multivariate analysis the factors with independent predictive value were: irregularity of density, ≥ 10 microcalcifications per cluster, the presence of more than one cluster, and diameter of the cluster ≥ 10 mm. Conclusions: Although none of the clinical factors analyzed was predictive for malignancy, the radiological characteristics of microcalcifications were determining factors in the indication for biopsy (AU)

[Predictive factors for malignancy in breast microcalcifications without associated lesions]. / Factores predictivos de malignidad en microcalcificaciones de mama sin lesiones asociadas.

INTRODUCTION: Screening mammography allows the early detection and treatment of nonpalpable carcinomas. Microcalcifications are highly important for the detection of many of these malignancies but are also present in benign breast disease. In the present study we analyzed the radiologic and clinical factors associated with malignancy. MATERIAL AND METHODS: We retrospectively reviewed 133 patients who underwent open biopsy after a mammographic finding of microcalcifications without an associated lesion. Clinical and radiologic characteristics were correlated with histologic findings. RESULTS: A total of 28.6% of the lesions analyzed were malignant. Of these, 65.8% were ductal carcinoma in situ. Among invasive carcinomas, 23.1% presented lymph node metastasis. No clinical criterion was significant for malignancy. On univariate analysis six radiologic criteria were significant: morphologic type (Le Gal's classification), irregularity of size, irregularity of density, number of microcalcifications per cluster, diameter of the lesion, and the presence of more than one cluster. On multivariate analysis the factors with independent predictive value were: irregularity of density, > or = 10 microcalcifications per cluster, the presence of more than one cluster, and diameter of the cluster > or = 10 mm. CONCLUSIONS: Although none of the clinical factors analyzed was predictive for malignancy, the radiological characteristics of microcalcifications were determining factors in the indication for biopsy.