Blood Biomarkers from Research Use to Clinical Practice: What Must Be Done? A Report from the EU/US CTAD Task Force.

Timely and accurate diagnosis of Alzheimer's disease (AD) in clinical practice remains challenging. PET and CSF biomarkers are the most widely used biomarkers to aid diagnosis in clinical research but present limitations for clinical practice (i.e., cost, accessibility). Emerging blood-based markers have the potential to be accurate, cost-effective, and easily accessible for widespread clinical use, and could facilitate timely diagnosis. The EU/US CTAD Task Force met in May 2022 in a virtual meeting to discuss pathways to implementation of blood-based markers in clinical practice. Specifically, the CTAD Task Force assessed: the state-of-art for blood-based markers, the current use of blood-based markers in clinical trials, the potential use of blood-based markers in clinical practice, the current challenges with blood-based markers, and the next steps needed for broader adoption in clinical practice.

Evaluation of a Cooperia oncophora double-domain ASP-based vaccine against Cooperia spp. infections in cattle and sheep.

A double-domain activation-associated secreted protein (dd-Co-ASP) isolated from the bovine small intestinal parasite Cooperia oncophora was previously shown to be an effective vaccine candidate to protect calves against a homologous challenge infection. The aim of this study was to investigate whether the dd-Co-ASP protein, purified from a Belgian C. oncophora isolate, would offer protection against a C. oncophora isolate from the southern hemisphere as well as other Cooperia species such as C. punctata in cattle and C. curticei in sheep. Two vaccination studies were performed, i.e. one in cattle and one in sheep, in which the protective effects of dd-Co-ASP, supplemented with Quil A as an adjuvant, were compared with an adjuvant control. Whereas our results showed a 75 % reduction in Cooperia spp. cumulative faecal egg counts, the results obtained in sheep demonstrated that dd-Co-ASP was ineffective in raising a protective immune response against a C. curticei challenge infection. Even though sequence analysis of the dd-Co-ASP gene revealed restricted sequence heterogeneity in the double domain ASP within and between bovine Cooperia species, the results of the vaccine study suggest that there is sufficient conservation at the protein level to yield cross-protection, holding promise for the development of a general Cooperia vaccine for use in cattle.

Yttrium-90 radiosynovectomy in knees and ankles (25 joints in 22 hemophilic patients). Short-term results

ABSTRACT Introduction: The radiosynovectomy (RS) is one treatment option for recurrent hemarthrosis in patients with hemophilia (PWH). A prospective cohort study was designed to evaluate the effects of the RS on the synovial membrane volume in the ankles and knees of PWH and patient characteristics related to the RS outcome. Methods: In a one-year follow-up, 25 joints of 22 PWH who presented 3 bleeds or more in the same joint over the last 6 months (target joints) were subjected to the RS. Two groups were compared: those who retained target joints following the RS and those who did not (less than 3 bleeds/6 months after the RS). The groups were analyzed according to age, hemophilia type/severity, joint, body mass index (BMI), inhibitor and Hemophilia Joint Health Score 2.1 (HJHS). The magnetic resonance images (MRI) of six ankles and six knees were acquired prior to, and 6 months after, the RS. The synovial membrane volume and arthropathy MRI scale were accessed and volumes were compared and correlated with the Yttrium-90 dose injected. Results: Patients with a mean age of 12 years and a mean HJHS of 6.7 (p < 0.05) retained target joints after the RS. The inhibitor, joint, type/severity of disease and BMI showed no significant differences between groups. The synovial membrane volume had a significant reduction after the RS (p = 0.03), but no correlation with the Yttrium-90 dose. In proportion to the synovial membrane volume, doses injected to the ankles were larger than those injected to the knees. Conclusion: The synovial membrane volume is reduced after the RS, regardless of the effective 90Y dose.

Yttrium-90 radiosynovectomy in knees and ankles (25 joints in 22 hemophilic patients). Short-term results.

INTRODUCTION: The radiosynovectomy (RS) is one treatment option for recurrent hemarthrosis in patients with hemophilia (PWH). A prospective cohort study was designed to evaluate the effects of the RS on the synovial membrane volume in the ankles and knees of PWH and patient characteristics related to the RS outcome. METHODS: In a one-year follow-up, 25 joints of 22 PWH who presented 3 bleeds or more in the same joint over the last 6 months (target joints) were subjected to the RS. Two groups were compared: those who retained target joints following the RS and those who did not (less than 3 bleeds/6 months after the RS). The groups were analyzed according to age, hemophilia type/severity, joint, body mass index (BMI), inhibitor and Hemophilia Joint Health Score 2.1 (HJHS). The magnetic resonance images (MRI) of six ankles and six knees were acquired prior to, and 6 months after, the RS. The synovial membrane volume and arthropathy MRI scale were accessed and volumes were compared and correlated with the Yttrium-90 dose injected. RESULTS: Patients with a mean age of 12 years and a mean HJHS of 6.7 (p < 0.05) retained target joints after the RS. The inhibitor, joint, type/severity of disease and BMI showed no significant differences between groups. The synovial membrane volume had a significant reduction after the RS (p = 0.03), but no correlation with the Yttrium-90 dose. In proportion to the synovial membrane volume, doses injected to the ankles were larger than those injected to the knees. CONCLUSION: The synovial membrane volume is reduced after the RS, regardless of the effective 90Y dose.

Effect of early shearing during gestation on the productive and reproductive behavior of female sheep offspring in their first 18 months of age.

The research has shown the interesting contributions of shearing in mid-gestation on the performance of lambs from birth to weaning. Other studies have reported that shearing at early pregnancy influences the development of the placenta and lamb live weight at birth. However, there was a lack of information on the effect of early-prepartum shearing on the behavior of the offspring from weaning onward. This study evaluated the effect of shearing ewes at 50 days of gestation on the growth, reproductive behavior and response to a gastrointestinal parasite challenge in the female offspring from weaning to 18 months old. Fifty-seven Polwarth female lambs were used, 22 being singles and 35 twins born to ewes either shorn at 50 days of pregnancy (PS, n = 23) or shorn at 62 days postpartum (U, control, n = 34) resulting in four subgroups: single lambs born to PS ewes (n = 8), born to U ewes (n = 14), twin lambs born to PS ewes (n = 15) or born to U ewes (n = 20). All progeny were managed together under improved pasture with a minimum forage allowance of 6% live weight on dry basis. Body weight, body condition score and fecal eggs count were recorded every 14 days from weaning to 18 months of age. Concentrations of progesterone were measured weekly (from 4 to 10 months of age and from 14 to 18 months of age) to establish the onset of puberty. Ovulation rate at an induced and a natural heat (545 ± 1.0 and 562 ± 1.0 day old) was recorded. Prepartum shearing did not affect the age at puberty or the ovulation rate of female offspring, but those born as singles were more precocious ( P = 0.03) and heavier ( P = 0.02) at puberty than twin born lambs. Both the average value of parasite egg count ( P = 0.0 7) and the Famacha index ( P = 0.02) for the entire study period were lower in lambs born to prepartum shorn ewes than those born to postpartum shorn ewes. In conclusion, shearing at 50 days of gestation did not affect the growth or the reproductive behavior of female offspring. However, female lambs born from ewe shorn during gestation showed a better response to the parasitic challenge, and further research is required to confirm this.

First molecular characterization of Galba neotropica in Uruguay

Until recently, it was believed that only two lymnaeid species (i.e. Galba viatrix and Pseudosuccinea columella) occurred in Uruguay. However, based on a molecular approach, an additional species Galba cubensis, was recently discovered. The aim of this study was to molecularly characterize different lymnaeid populations from the northern region of Uruguay. The lymnaeids collections were carried out in two farms of the departments of Paysandú and Tacuarembó. The collected lymnaeids were divided in two fractions, one fraction was used for conchological analyses and detection of trematode larval stages, while the other fraction was used for molecular studies. Three PCRs targeting the 16S, ITS-2 and COI DNA regions were performed and the amplicons obtained were direct sequenced. The sequences were used for homology search and construction of phylogenetic trees by the maximum-likelihood method. The sequencing results revealed that both isolates corresponded to Galba neotropica. The phylogenetic analyses placed our isolates among the G. neotropica monophyletic group, closely related to other isolates of this species found in several South American countries. To our knowledge, this is the first record of G. neotropica in Uruguay and the confirmation as competent intermediate host of Fasciola hepatica. Further studies are needed to define the distribution and the role of each lymnaeid species in the transmission of F. hepatica in Uruguay.

Tradicionalmente se indicaba que existían dos especies de limneidos en Uruguay: Galba viatrix y Pseudosuccinea columella. Sin embargo, en los últimos años se identificó por medio de técnicas moleculares una tercera especie, Galba cubensis. El objetivo de los autores fue muestrear e identificar por medios moleculares poblaciones de limneidos del norte del país. Las colectas fueron realizadas en establecimientos rurales de los departamentos de Tacuarembó y Paysandú. Los caracoles colectados fueron divididos en dos fracciones, una de ellas fue destinada para el estudio morfológico de las conchillas y búsqueda de larvas de trematodos. La otra fracción se usó para la caracterización molecular. Tres genes fueron amplificados (ITS2, COI y 16S) utilizando protocolos de PCRs previamente descriptos. Las secuencias obtenidas se utilizaron para estudios de homología y construcción de árboles filogenéticos por medio del método de máxima verosimilitud. Por medio de la secuenciación se pudo confirmar que los dos aislamientos corresponden a Galba neotropica. Los estudios filogenéticos colocan ambos aislamientos dentro del grupo monofilético de G. neotropica junto a otros encontrados en distintas regiones de Sudamérica. Hasta lo que sabemos, el presente, es el primer registro de G. neotropica en Uruguay, además de comprobarse su capacidad para actuar como hospedero intermediario de Fasciola hepatica en condiciones de campo. Se sugieren futuros estudios para determinar la distribución y el rol de cada especie de limneido en la transmisión de F. hepatica.

No Correlation of Morpho-Agronomic Traits of Phaseolus vulgaris (Fabaceae) Genotypes and Resistance to Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boheman) (Coleoptera: Chrysomelidae).

Resistance of common bean (Phaseolus vulgaris) varieties is an important tool to control Acanthoscelides obtectus (Say) and Zabrotes subfasciatus (Boheman) (Coleoptera: Chrysomelidae: Bruchinae) worldwide. However, bioassays to characterize the resistance of a genotype can be difficult to perform. Therefore, the current study sought to correlate the morpho-agronomic traits of P. vulgaris genotypes with their resistance to A. obtectus and Z. subfasciatus to facilitate genotype characterization. Bean samples of each genotype were infested with newly emerged insect couples, and the number of adults obtained in each genotype was quantified (value used as a resistance parameter). The resistance index was calculated by dividing the number of adults obtained in each genotype by the one obtained in the cultivar Bolinha, used as the standard for susceptibility. Fifty genotypes were evaluated for A. obtectus and 202 for Z. subfasciatus. All genotypes were characterized according to their resistance to each insect and 18 other morpho-agronomic traits, for a total of 19 descriptors. Principal component analyses did not show any correlation between insect resistance and the morpho-agronomic traits of the genotypes. Further, the thousand seeds weight (TSW), which is indicative of the genotype center of origin was tested considering genotypes from Mesoamerican with low TSW, while those from Andean with high TSW. Thus, the lack of correlation between genotype resistance and TSW indicates that resistance to A. obtectus and Z. subfasciatus in P. vulgaris is not related to the host center of origin.

Evaluation of indigenous bacterial strains for biocontrol of the frogeye leaf spot of soya bean caused by Cercospora sojina.

AIMS: Assessment of biological control of Cercospora sojina, causal agent of frogeye leaf spot (FLS) of soya bean, using three indigenous bacterial strains, BNM297 (Pseudomonas fluorescens), BNM340 and BNM122 (Bacillus amyloliquefaciens). METHODS AND RESULTS: From cultures of each bacterial strain, cell suspensions and cell-free supernatants were obtained and assayed to determine their antifungal activity against C. sojina. Both mycelial growth and spore germination in vitro were more strongly inhibited by bacterial cell suspensions than by cell-free supernatants. The Bacillus strains BNM122 and BNM340 inhibited the fungal growth to a similar degree (I ≈ 52-53%), while cells from P. fluorescens BNM297 caused a lesser reduction (I ≈ 32-34%) in the fungus colony diameter. The foliar application of the two Bacillus strains on soya bean seedlings, under greenhouse conditions, significantly reduced the disease severity with respect to control soya bean seedlings and those sprayed with BNM297. This last bacterial strain was not effective in controlling FLS in vivo. CONCLUSIONS: Our data demonstrate that the application of antagonistic bacteria may be a promising and environmentally friendly alternative to control the FLS of soya bean. SIGNIFICANCE AND IMPACT OF THE STUDY: To our knowledge, this is the first report of biological control of C. sojina by using native Bacillus strains.

Effects of the ingestion of 2, 4 Dichlorophenoxyacetic acid on jejunal myenteric neurons in rats

2,4 dichlorophenoxyacetic acid (2,4-D) is a systemic herbicide. The effects of different levels of 2,4-D on some animal organ systems have been examined, but little is known about its role in the enteric nervous system. The purpose of this study was to verify the effects of 2,4-D administration on the density and morphometry of jejunal myenteric neurons in rats. Ten male rats were assigned to control (C) and experimental (E) groups. For 15 days, group E received, via gavage, 5 mg of 2,4-D.kg–1 body weight. On the 16th day, the animals were sacrificed by a lethal dose of thiopental, and the jejunum was removed by laparotomy and used to obtain whole mount preparations for Giemsa staining and NADPH-diaphorase (NADPHd+) histochemistry to identify neurons. The density and cell body area of the myenteric neurons was measured. In the total neuronal population, the neuronal density/mm2 of the jejunum in groups E and C was equivalent, and the cell body area of the rats in group E was lower (p < 0.05) than that of those in group C. For NADPHd+ neurons, the neuronal density did not differ between the groups, although the cell body area was larger (p < 0.05) in group E. It was concluded that even though 2,4-D does not alter the neuronal density in the rat jejunum, it induces cell body atrophy in the general population of neurons and hypertrophy of the NADPHd+ nitric oxide producing neurons without promoting cell death.

Comparative drug systemic exposure and clinical efficacy against resistant nematodes in lambs treated with different albendazole formulations.

A pharmaco-parasitological assessment of four different albendazole (ABZ) formulations was carried out in lambs infected with multiple resistant gastrointestinal (GI) nematodes. The comparative drug systemic exposure profiles (ABZ sulphoxide plasma concentrations) and anthelmintic efficacies (clinical endpoint measured through the faecal nematode eggs reduction counts) were determined for a reference formulation (RF) and three different test (T1, T2, T3) generic ABZ preparations. Fifty (50) Corriedale lambs naturally infected with multiple resistant GI nematodes were allocated into five experimental groups (n = 10). Animals in each group received treatment with either the RF, one of the test ABZ formulations (5 mg/kg by the intraruminal route) or were kept as untreated control. Blood samples were collected over 48 h post-treatment. ABZ parent drug was not recovered in the bloodstream. The ABZ sulphoxide (ABZSO) and sulphone (ABZSO(2) ) metabolites were measured in plasma by ultraviolet high-performance liquid chromatography over 36-48 h post-treatment. A faecal nematode egg count reduction test (FECRT) was performed at day 10th post-treatment to lambs from all treated and untreated groups, which indicated the predominance of nematodes with high level of resistance to ABZ. Both ABZSO C(max) and AUC(0-LOQ) values obtained for the RF (pioneer product) were significantly higher (P < 0.05) than those obtained for the T1 and T3 preparations. Based on the currently available bioequivalence criteria, the test (generic) ABZ formulations under evaluation could not be considered equivalent to the RF regarding the rate (C(max) ) and extent (AUC(0-LOD) ) of drug absorption (indirectly estimated through the ABZSO metabolite). A large variation in nematode egg counts did not permit to obtain statistically significant differences among formulations. However, a favourable trend in the efficacy against the most resistant nematodes was observed for the formulations with the highest ABZSO systemic exposure.

[Epidural anesthesia for cesarean section in a patient with von Hippel-Lindau disease]. / Anestesia epidural para cesárea en una paciente con enfermedad de von Hippel-Lindau.

Von Hippel-Lindau disease is a dominant autosomal genetic condition with variable penetrance and expressivity. It is characterized by hemangioblastomas in multiple organs but mainly in the retina and cerebellum. There is a predisposition to carcinoma. We report a cesarean section in a 28-year-old woman with von Hippel-Lindau disease. She had no neurologic symptoms at the time of the operation but a history of ocular and cerebellar involvement and several procedures to remove cerebellar hemangioblastomas. Epidural anesthesia was chosen given that there was no nervous system involvement at the time of surgery.

Anestesia epidural para cesárea en una paciente con enfermedad de Von Hippel-Lindau / Epidural anesthesia for cesarean section in a patient with von Hippel-Lindau disease

La enfermedad de von Hippel Lindau es un transtornogenético autosómico dominante con penetranciavariable, caracterizado por hemangioblastomas multiorgánicosprincipalmente en la retina y cerebelo y con predisposicióna desarrollar carcinoma. Se comunica el casode una gestante a término de 28 años de edad, portadorade la enfermedad de von Hippel Lindau, sin clínicaneurológica en el momento de la cesárea, con historia deafectación ocular y cerebelosa, a quien se le habían extirpadohemangioblastomas cerebelosos en varias ocasiones.Se eligió anestesia epidural por no presentar afectacióndel sistema nervioso, en el momento de la cirugía(AU)

Von Hippel-Lindau disease is a dominant autosomalgenetic condition with variable penetrance and expre -ssivity. It is characterized by hemangioblastomas inmultiple organs but mainly in the retina and cerebellum.There is a predisposition to carcinoma. We report acesarean section in a 28-year-old woman with von Hippel-Lindau disease. She had no neurologic symptoms at thetime of the operation but a history of ocular and cerebellarinvolvement and several procedures to remove cerebellarhemangioblastomas. Epidural anesthesia was chosen giventhat there was no nervous system involvement at the timeof surgery(AU)

Antifungal activity of selected indigenous pseudomonas and bacillus from the soybean rhizosphere.

The purpose of this study was to isolate and select indigenous soil Pseudomonas and Bacillus bacteria capable of developing multiple mechanisms of action related to the biocontrol of phytopathogenic fungi affecting soybean crops. The screening procedure consisted of antagonism tests against a panel of phytopathogenic fungi, taxonomic identification, detection by PCR of several genes related to antifungal activity, in vitro detection of the antifungal products, and root colonization assays. Two isolates, identified and designated as Pseudomonas fluorescens BNM296 and Bacillus amyloliquefaciens BNM340, were selected for further studies. These isolates protected plants against the damping-off caused by Pythium ultimum and were able to increase the seedling emergence rate after inoculation of soybean seeds with each bacterium. Also, the shoot nitrogen content was higher in plants when seeds were inoculated with BNM296. The polyphasic approach of this work allowed us to select two indigenous bacterial strains that promoted the early development of soybean plants.

Assessment of the role of chemotaxis and biofilm formation as requirements for colonization of roots and seeds of soybean plants by Bacillus amyloliquefaciens BNM339.

This article correlates colonization with parameters, such as chemotaxis, biofilm formation, and bacterial growth, that are believed to be connected. We show here, by using two varieties of soybean plants that seeds axenically produced exudates, induced a chemotactic response in Bacillus amyloliquefaciens, whereas root exudates did not, even when the exudates, also collected under axenic conditions, were concentrated up to 200-fold. Root exudates did not support bacterial cell division, whereas seed exudates contain compounds that support active cell division and high cell biomass at stationary phase. Seed exudates of the two soybean varieties also induced biofilm formation. B. amyloliquefaciens colonized both seeds and roots, and plant variety significantly affected bacterial root colonization, whereas it did not affect seed colonization. Colonization of roots in B. amyloliquefaciens occurred despite the lack of chemotaxis and growth stimulation by root exudates. The data presented in this article suggest that soybean seed colonization, but not root colonization, by B. amyloliquefaciens is influenced by chemotaxis, growth, and biofilm formation and that this may be caused by qualitative changes of the composition of root exudates.

Tomato genotype and Azospirillum inoculation modulate the changes in bacterial communities associated with roots and leaves.

AIMS: To evaluate the effect of plant variety and Azospirillum brasilense inoculation on the microbial communities colonizing roots and leaves of tomato (Lycopersicon esculentum Mill.) plants. METHODS AND RESULTS: Seeds of cherry and fresh-market tomato were inoculated with A. brasilense BNM65. Sixty days after planting, plants were harvested and the microbial communities of the rhizoplane and phyllosphere were analysed by community-level physiological profiles (CLPP) using BIOLOG EcoPlates and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA genes. Differences on the rhizoplane and phyllosphere bacterial communities between the two tomato types were detected by principal component analysis of the CLPP; DGGE fingerprints also showed differences at the phyllosphere level. Fresh-market tomato had a more complex phyllosphere bacterial community than cherry tomato, as determined by DGGE profiles. Physiological and genetic changes on phyllosphere and rhizoplane bacterial communities by Azospirillum seed inoculation were evident only on cherry tomato. CONCLUSIONS: Tomato genotype affects the response of native bacterial communities associated with the roots and leaves to A. brasilense seed inoculation. SIGNIFICANCE AND IMPACT OF THE STUDY: The successful implementation of Azospirillum inoculation requires not only the consideration of the interactions between A. brasilense strains and plant genotypes, but also the plant-associated microflora.

Genetic and functional characterization of a Bacillus sp. strain excreting surfactin and antifungal metabolites partially identified as iturin-like compounds.

AIMS: A bacterial strain producing antifungal compounds active against the plant pathogenic fungi Fusarium, Rhizoctonia and Sclerotinia has been characterized and shown to control Rhizoctonia root rot of soya bean. METHODS AND RESULTS: The metabolites excreted by Bacillus BNM 122 remained active after autoclaving, were resistant over a wide pH range and to hydrolytic enzymes. By (1)H-NMR and thin-layer chromatography analyses surfactin and iturin-like compounds were partially identified. Moreover, soya bean seeds bacterization with BNM 122 in a compost-based formulation was as effective controlling Rhizoctonia solani as pentachloronitrobenzene. According to its 16S rDNA sequence BNM 122 was closely related to Bacillus amyloliquefaciens and Bacillus subtilis. PCR analysis of the 16S-23S rRNA intergenic spacer region and repetitive sequence-based PCR (rep-PCR) genomic fingerprinting revealed a close genetic relationship to B. amyloliquefaciens. However, by physiological characterization using API tests, this strain resembled more B. subtilis. CONCLUSIONS: This is the first report describing the co-production of surfactin and iturin-like compounds by a putative strain of B. amyloliquefaciens. The synergistic effect of both lipopetides is a remarkable trait for a candidate biocontrol agent. SIGNIFICANCE AND IMPACT OF THE STUDY: This kind of research has relevance in order to minimize the use of synthetic fungicides and surfactants, contributing to the preservation of the environment.

An investigation of sterile immunity against toxoplasmosis in rats.

The non-persistent BK strain was examined for its ability to induce sterile immunity in Wistar rats. Groups of 2-9 Wistar rats were inoculated subcutaneously with 5 x 10(4) BK strain tachyzoites per rat. Two months later, 46 rats were dosed by gavage with 2 x 10(1) cysts of the C, ME-49, Prugniaud, C-56, Elg, M-7741 or M3 strains. Another 26 rats were inoculated with 10(3) oocysts of the ME49, M7741, Bear or Hopa-Hopa strains of Toxoplasma gondii. After 2 months, the rats were euthanized and their brains screened microscopically for toxoplasma tissue cysts and bioassayed in mice if negative. As judged by bioassay, the BK strain of Toxoplasma induced statistically significant protection against reinfection only when rats were challenged with cysts of the C and Prugniaud strains or with oocysts of the ME49 strain. Nonetheless, cysts were detected microscopically only in 23% of brains of immunized rats challenged with oocysts of the Bear and Hopa-Hopa strains of Toxoplasma and none of those challenged with tissue cysts of any strain. Tissue cysts were detected in 43 and 48% of non-immunized control rats infected with tissue cysts and oocysts, respectively. The overall infection in control rats (microscopy and bioassay) was 70 and 72% for rats inoculated with cysts and oocysts, respectively. These results are consistent with the divergent results obtained by other investigators with regard to protection after challenge with different complete strains (cyst and oocysts forming) of the parasite, of rats immunized with incomplete strains.

Effect of Azospirillum-mediated plant growth promotion on the development of bacterial diseases on fresh-market and cherry tomato.

AIMS: Plant growth-promoting (PGP) activity of two Azospirillum strains and their effects on foliar and vascular bacterial diseases were evaluated on fresh market and cherry tomato. METHODS AND RESULTS: Tomato seeds were inoculated with A. brasilense Sp7 or Azospirillum sp. BNM-65. Four-week-old plants were challenge-inoculated with Clavibacter michiganensis subsp. michiganensis (bacterial canker) or with Xanthomonas campestris pv. vesicatoria (bacterial spot). Azospirillum-induced PGP was greater on cherry than on fresh-market tomato. Cherry tomato was more resistant to bacterial canker but more susceptible to bacterial spot than the fresh-market tomato. Canker severity was not affected by Azospirillum seed treatments. However, leaf- and plant-death were delayed on Azospirillum-treated plants compared with nontreated controls. Azospirillum increased the bacterial spot severity on cherry but not on fresh-market tomato. CONCLUSIONS: PGP was observed on both tomato genotypes, although growth effects were larger on cherry tomato. Also, Azospirillum treatments may alter tomato susceptibility to bacterial diseases. SIGNIFICANCE AND IMPACT OF THE STUDY: The interaction between PGP rhizobacteria like Azospirillum spp., not known to induce systemic resistance, with plant pathogens distantly located is frequently overlooked. This work demonstrates the importance of this kind of evaluation.

Cyst burden in the brains of Wistar rats fed Toxoplasma oocysts.

Six strains of Toxoplasma oocysts were used to infect groups of 4-24 Wistar rats, with each rat being fed 10(1)-10(4) oocysts from a single strain. After 2 months, the rats were killed, their brains screened for Toxoplasma cysts and then bioassayed in mice if negative. Toxoplasma was either observed in the form of brain cysts or was recovered using the bioassay, from 113 out of 138 (82%) rat brains. As few as ten oocysts were capable of initiating a brain infection that lasted for at least 2 months in eight of the nine rats inoculated. However, judging from bioassay 10(2)-10(4) oocysts did not give rise to progressively higher rates of infection. Brain cysts were seen in only 68 of 138 rats (49%). The number of Toxoplasma cysts formed in the brains of rats was generally in the order of tens to hundreds. The frequency of infection in the brains with Toxoplasma and the number of brain cysts formed appeared to be influenced by the individual resistance of the rats as well as by the doses of oocysts and the Toxoplasma strains used. The information gathered is considered to be a basis for a rat model of immunity against acquired toxoplasmosis.

Enzyme-mediated solvent extraction of carotenoids from marigold flower (Tagetes erecta).

Marigold flowers are the most important source of carotenoids for application in the food industry. However, the extraction gives almost 50% losses of the carotenoids depending on conditions for silaging, drying, and solvent extraction. In the past decades, macerating enzymes have been successfully applied to improve the extraction yield of valued compounds from natural products. In this work, an alternative extraction process for carotenoids is proposed, consisting of a simultaneous enzymatic treatment and solvent extraction. The proposed process employs milled fresh flowers directly as raw material, eliminating the inefficient silage and drying operations as well as the generation of hard to deal with aqueous effluents present in traditional processes. The process developed was tested at the 80 L scale, where under optimal conditions a carotenoid recovery yield of 97% was obtained.