Nutritive Value of Wheat Bran Diets Supplemented With Fresh Carrots and Wet Brewers' Grains in Yellow Mealworm

We evaluated the effect of supplementation of a wheat bran (WB) diet with fresh carrots (FC) or wet brewer's grains (WBG) on the growth performance and chemical composition of Tenebrio molitor larvae. Additionally, a digestibility trial was performed to determine the nutritional value of the raw materials used. The control diet was based on WB-only. Two other diets were formulated in which WB was supplemented with FC (FC diet) or with WBG (WBG diet). The experiment was conducted in trays (12 per treatment) and lasted 90 d. Larval weight, feed intake, and excreted feces were controlled in each tray the experiment. The digestibility trial was performed from 48 to 62 d post-hatch. Results showed digestibility coefficients of ashes, crude protein, and gross energy were significantly higher in FC diet compared with the other diets. Consequently, both digestible energy (DE) and digestible protein (DP) contents of FC were also significantly higher than those obtained for WB and WBG diets (on av. +1.12 megajoule [MJ] DE and +9.15 g DP per kg dry matter [DM]; P < 0.003). Mealworms fed FC diet showed significantly higher final weight and average daily gain than those fed the WBG diet (+12.4%), being higher in WBG than in WB diet (+3.5%). Dietary treatment did not affect DM, ashes, ether extract, and crude protein content of mealworms obtained. Some dietary effects on amino acid and fatty acid composition were observed. This study provides novel data and a unique experimental approach to assess the nutritional value of raw materials in mealworms.

Leptospira seroprevalence in owned dogs from Spain

Leptospira is a widespread zoonosis that has been linked to transmission between dogs and humans. The main purposes were to determine the seroprevalence of anti-Leptospira serum antibody and to identify the most common serovars in dogs in Spain. This is a cross-sectional study with 1,310 records of canine Leptospira testing data from Spain since 2015 to 2017. Inclusion criteria were individual cases with MAT test results for 8 serovars (Bratislava, Icterohaemorrhagiae, Australis, Pomona, Grippotyphosa, Autumnalis, Canicola and Saxkoebing) and to have the zip code data. Three hundred and thirty-eight samples (25.8%; 95%CI 23.6–28.4) were seropositive (≥1:100). According to geographic areas, North had the highest seroprevalence (38.0%; 95%CI 28.9–47.1) followed by South (29.4%; 95%CI 20.1–38.8), Center (28.6%; 95%CI 24.3–33.0), Mediterranean (22.3%; 95%CI 19.1–25.6) and Northwest (22.2%; 95%CI 7.9–36.4). Seropositivity (MAT ≥1:100) was most common to serovars Icterohaemorrhagiae (19.4%; 95%CI 17.2–21.5) and Bratislava (8.5%; 95%CI 7.0–10.0), followed by Grippotyphosa (7.2%; 95%CI 5.8–8.6), Australis (6.4%; 95%CI 5.0–7.7), Autumnalis (5.0%; 95%CI 3.8–6.2), Pomona (4.5%; 95%CI 3.3–5.6), Canicola (3.4%; 95%CI 2.4–4.4) and Saxkoebing (0.8%; 95%CI 0.3–1.3). An association was found between positivity (MAT ≥1:100) and males (P = 0.003) and dogs that were 6 years old or older were at higher risk of exposure (P = 0.001; OR 4.61; 95%CI 1.86–11.43). This study has shown that dogs in Spain are commonly exposed to Leptospira infection and points out the necessity to control the prevalence of this severe widespread zoonosis in dogs and humans.

Longitudinal monitoring of anti-saliva antibodies as markers of repellent efficacy against Phlebotomus perniciosus and Phlebotomus papatasi in dogs

A 2-year longitudinal study of enzyme-linked immunosorbent assay (ELISA) antibodies against Phlebotomus perniciosus and Phlebotomus papatasi (Diptera: Psychodidae) sandfly saliva was performed in 32 Beagle dogs treated preventively with an imidacloprid-permethrin topical insecticide in an endemic area in Spain. Dogs were grouped into three sandfly exposure groups according to the time of inclusion in the study. Assays analysed immunoglobulin G (IgG) against salivary gland homogenates (SGH) of both species and recombinant P. papatasi rSP32 and P. perniciosus rSP03B proteins in serum. The dogs were participating in a Leishmania infantum (Kinetoplastida: Trypanosomatidae) vaccine trial and were experimentally infected with the parasite in the second year. No dog acquired natural L. infantum infections during the first year, but most developed anti-saliva antibodies, and median log-transformed optical densities (LODs) were seasonal, mimicking those of local sandflies. This indicates that the repellent efficacy of the insecticide used is below 100%. Multi-level modelling of LODs revealed variability among dogs, autocorrelation and differences according to the salivary antigen and the dog's age. However, dog seroprevalence, estimated using pre-exposure LODs as cut-offs, was relatively low. This, and the fact that dogs did not become naturally infected with L. infantum, would support the efficacy and usefulness of this imidacloprid-permethrin topical insecticide in canine leishmaniasis control.

Bactericidal activity of human milk: stability during storage

Human milk provides infants with defensive factors against many illnesses. This study aims to analyse global bactericidal activity in fresh human milk and evaluate its stability in relation to milk manipulation and its possible alteration following refrigeration. Nineteen milk samples (mature milk) from 19 healthy women are analysed. Viability testing involving a strain of Escherichia coli NCTC 9111, serovar O111:K58(B4):H- was used to determine the bactericidal effect of human milk. Degree of bacteriolysis is calculated as the difference between E. coli counts in controls and in milk samples, expressed as a percentage of the control sample counts. An evaluation of the effect of refrigeration at 4-6 degrees C after 24, 48 and 72 hours, and at -20 degrees C for seven days on bactericidal capacity is made. Bactericidal activity was detected in all milk samples analysed (77.33 +/- 15.14%). This activity persisted after refrigeration for 48 hours and after freezing for 10 days, but showed a significant decrease after refrigeration for 72 hours. In conclusion, maternal milk has bactericidal capacity, providing defence and protection against infection for newborn infants. This property can be altered during the storage of milk. Consequently, if storage in excess of 48 hours is required, freezing is preferable to refrigeration.

Effect of replacing dietary corn with beet pulp on energy partitioning, substrate oxidation and methane production in lactating dairy goats

The objective of this experiment was to study the effect of substitution of corn by beet pulp on energy partitioning, substrate oxidation, nitrogen and carbon balance and milk performance in dairy goats during late lactation. Twelve multiparous lactating Murciano-Granadina goats were fed two diets. Six goats were fed a mixed ration with 310 g/kg DM of ground corn (diet CORN) and in the other diet the corn was substituted with 302 g/kg DM of beet pulp (diet BP) in a cross-over design. No significant differences between diets were observed for milk production (1.36 kg/day, on average) and differences were found for milk fat (5.39 and 4.21% for BP and CORN, respectively). The metabolisable energy intake was higher (P < 0.05) in the CORN diet than BP (1320 vs 1044 kJ/kg0.75 BW, respectively). The difference in methane emissions between treatments was significant (P < 0.05) with values of 92 vs 61 kJ/kg0.75 BW for BP and CORN, respectively, indicating that greater levels of starch in diet reduce methane production. Replacing corn with BP reduced significantly the energy body fat deposition (300 vs 44 kJ/kg0.75 BW for CORN and BP diets, respectively). This reduction in energy retention for the BP diet did not compromise milk yield and milk energy output.

Use of dry citrus pulp or soybean hulls as a replacement for corn grain in energy and nitrogen partitioning, methane emissions, and milk performance in lactating Murciano-Granadina goats

The aim of this study was to assess the effect of substitution of dietary corn grain by dry citrus pulp or soybean hulls on energy and nitrogen partitioning, substrate oxidation, methane emission, and milk performance in dairy goats during midlactation. Twelve multiparous Murciano-Granadina goats of similar body weight (41.7 ± 2.8 kg) were split in 3 groups in an incomplete crossover design. One group of 4 goats was fed a mixed ration with 605 g/kg of dry matter of corn grain (CRG), another group replaced corn grain with dry citrus pulp (CTP), and the last with soybean hulls (SYH). The goats were allocated to individual metabolism cages. After 14 d of adaptation, feed intake, total fecal and urine output, and milk yield were recorded daily over a 5-d period. Then, gas exchange measurements were recorded by a mobile open-circuit indirect calorimetry system using a head box. Dry matter intake was similar for all 3 groups (1.53 kg/d, on average). Total replacement of the concentrate with fibrous by-products increased fiber apparent digestibility. The metabolizable energy intake was significantly greater for diet CRG than SYH (1,193 vs. 1,079 kJ/kg of BW⁰·⁷⁵, respectively), CTP showed an intermediate value. The heat production was higher for the fiber diet than starchy diet (908 vs. 843 kJ/kg of BW⁰·⁷⁵ for SYH and CRG, respectively). The efficiency of use of metabolizable energy for milk production obtained by regression was 0.59. Goats fed CTP and SYH diets produced similar CH₄ emissions (34.8 g/d, on average), significantly higher compared with goats fed the CRG diet (24.7 g/d). Goats of the 3 treatments were in negative energy balance, so the oxidation of fat was greater than for carbohydrates. No significant differences were observed for milk production (1.72 kg/d), and milk fat was significantly greater for a more fibrous diet compared with a starchy diet (6.57 vs. 4.95% in SYH and CRG, respectively).

Benznidazole treatment reduces the induction of indoleamine 2,3-dioxygenase (IDO) enzymatic activity in Chagas disease symptomatic patients

The enzyme indoleamine 2,3-dioxigenase (IDO) is critical for the regulation of immune responses in pro-tolerogenic antigen-presenting cell. To address the profile of immune responses associated with Chagas disease, we measured IDO activity of peripheral blood mononuclear cells from 168 chronic patients and 13 healthy donors. We found that IDO activity was increased in patients with Chagas disease when compared with controls. Moreover, the IDO activity of patients with Chagas disease in the symptomatic chronic phase, involving cardiac or digestive alterations, was higher than that detected in asymptomatic patients and correlated with the severity of the symptoms. Furthermore, benznidazole treatment induced a long-lasting decrease in IDO activity in symptomatic patients, reaching levels comparable with those of healthy donors. These results suggest that a pro-tolerogenic state is associated with the severity of Chagas disease and that benznidazole treatment is a valuable tool for breaking the parasite-driven immune tolerance in the symptomatic chronic phase of Chagas disease.

Effects of Pepper (Capsicum annuum) Cultivars on the Biology and Life Table Parameters of Myzus persicae (Sulz.) (Hemiptera: Aphididae)

Green peach aphids, Myzus persicae (Sulz.) (Hemiptera: Aphididae), obtained from pepper fields, were colonized on susceptible pepper plants in a growth chamber. The development, survivorship, and life table parameters of the green peach aphid were evaluated on nine peppers cultivars as follows: Almuden, Bilano, Bird, Cabezo, de la Sierra, Eppo, Jaen, Raza, and Yatasto at controlled conditions (20 ± 1°C; about 70% RH; 14h photophase). The development times of immatures ranged from 6.1 days on Yatasto to 11.4 days on Jaen, whereas immature survival was close to 100% on all cultivars. The intrinsic rate of increase (r m ) for green peach aphid on Bilano and Yatasto were the highest. Jackknife estimates of r m varied from 0.281 to 0.174 females/female/day on Yatasto and Jaen, respectively. The mean population generation times (T) on these hosts ranged from 13.7 to 22.7 days. The highest net reproductive rates (R 0 ) were on Bird and Bilano (63.8 and 62.89 females/female/generation, respectively) and the lowest on De la Sierra and Almuden (34.1 and 38.7, respectively). Because of the high coefficient of determination (R (2)) values in Gompertz and Weibul models, survival data from different cultivars had a good fit to both models. The results pointed Jaen, Almuden, and Raza cultivars as the least suitable host plants, indicating that they were the most resistant to M. persicae among the cultivars we tested.

Towards a paradigm shift in the treatment of chronic Chagas disease

Treatment for Chagas disease with currently available medications is recommended universally only for acute cases (all ages) and for children up to 14 years old. The World Health Organization, however, also recommends specific antiparasite treatment for all chronic-phase Trypanosoma cruzi-infected individuals, even though in current medical practice this remains controversial, and most physicians only prescribe palliative treatment for adult Chagas patients with dilated cardiomyopathy. The present opinion, prepared by members of the NHEPACHA network (Nuevas Herramientas para el Diagnóstico y la Evaluación del Paciente con Enfermedad de Chagas/New Tools for the Diagnosis and Evaluation of Chagas Disease Patients), reviews the paradigm shift based on clinical and immunological evidence and argues in favor of antiparasitic treatment for all chronic patients. We review the tools needed to monitor therapeutic efficacy and the potential criteria for evaluation of treatment efficacy beyond parasitological cure. Etiological treatment should now be mandatory for all adult chronic Chagas disease patients.

Energy partitioning and substrate oxidation by Murciano-Granadina goats during mid lactation fed soy hulls and corn gluten feed blend as a replacement for corn grain

The aim of this experiment was to study the effect of substituting corn grain by soy hulls and corn gluten feed blend on energy partitioning, substrate oxidation, and milk performance in dairy goats during mid lactation. Ten multiparous Murciano-Granadina goats in mid lactation were fed 2 isoenergetic and isoproteic diets [19.08MJ/kg of dry matter (DM) and 18.7% of CP, DM basis] in a crossover design. One group of 5 goats was fed a mixed ration with 373g of corn grain/kg of DM (CRN diet) and the other diet replaced corn grain with 373g/kg DM of fibrous by-products [soy hulls and gluten feed (SHGF) diet]: 227g of soy hulls/kg of DM and 146g of gluten feed blend/kg DM. Fat was added to the SHGF diet to make it isoenergetic. After 10d of adaptation, the feed intake, refusal, total fecal and urine output, and milk yield were recorded daily over a 5-d period. Then, gas exchange measurements were recorded by a mobile open-circuit respirometry system using a head box for 10d. Dry matter intake was similar for both diets (2.07kg/d, on average). Greater and significant values were found in the SHGF diet for ammonia N, energy in urine, and oxidation of protein. Values were significantly lower for heat production of fermentation, indicating a decrease in rumen fermentation with this diet, probably due to an excess of crude protein in the diet and lack of synchronization of the nonfiber carbohydrates with rumen-degraded protein. The metabolizable energy intake was no different between CRN and SHGF treatments, with an average value of 1,444kJ/kg of BW(0.75). Due to the positive energy balance during mid lactation in this trial, most of the heat production from oxidation of nutrients derived from carbohydrate oxidation (55%, on average), followed by oxidation of fat (29%, on average). No significant differences were observed for milk production, although milk fat was significantly greater for the SHGF diet than the CRN diet (7.0 vs. 5.4%, respectively). Despite the different starch levels and fibrous content used in these mixed diets, no significant differences for the efficiency of use of metabolizable energy for late lactation were observed (0.63, on average). An average nutritive value of 7.52MJ of net energy of lactation/kg of DM was obtained. This fibrous by-product was utilized by lactating goats without detrimental effect on energy metabolism and resulted in similar performance to grain bases diet. The economic advantages and sustainability of this choice should be evaluated.

Oral transmission of Chagas disease: typing of Trypanosoma cruzi from five outbreaks occurred in Venezuela shows multiclonal and common infections in patients, vectors and reservoirs

In Venezuela six episodes of oral transmission of Chagas disease (OChD) have been described, being the one reported in 2007 with a total of 103 people infected the largest worldwide. This work shows the use of three molecular markers (mini-exon gene and domains 24Sα and 18S of the ribosomal RNA) to characterize the infecting Trypanosoma cruzi strain of patients, reservoirs and vectors involved in five of the six OChD outbreaks. For this, 28 T. cruzi isolates were characterized by PCR, and the products of these reactions cloned and sequenced to reveal the existence of different TcI SL-IR genotypes. We also describe a new PCR assay able to discriminate between TcIb and TcId parasite populations. In summary, we have identified mostly parasites with the TcId haplotype and multiclonal populations with predominance of haplotype TcId (65.2%). Additionally, populations of haplotypes TcIb, TcIa and mixtures (TcId+TcIb, TcId+TcIa, TcIb+TcIa) are recurrent in samples obtained from children. The analysis of the SL-IR motif showed two clones depicting a different motif that could be an evidence for a possible hybrid haplotype between TcIa and TcIb (haplotype TcIa/Ib). Interestingly, in a single patient haplotype differences between T.cruzi isolates obtained pre and post-treatment were found. In conclusion, our findings show that in order to understand the pathogenic mechanisms involved in the orally acquired Chagas disease there is a need to join efforts to study T. cruzi haplotypes, their tissue tropisms and their susceptibility to chemoteraphy.

Genome-wide linkage scan of bipolar disorder in a Colombian population isolate replicates Loci on chromosomes 7p21-22, 1p31, 16p12 and 21q21-22 and identifies a novel locus on chromosome 12q

BACKGROUND/AIMS

Bipolar disorder (BP) is a severe psychiatric illness, characterised by alternating episodes of depression and mania, which ranks among the top ten causes of morbidity and life-long disability world-wide. We have previously performed a whole-genome linkage scan on 6 pedigrees segregating severe BP from the well-characterised population isolate of Antioquia, Colombia. We recently collected genotypes for the same set of 382 autosomal microsatellite markers in 9 additional Antioquian BP pedigrees. Here, we report the analysis of the combined pedigree set.

METHODS

Linkage analysis using both parametric and nonparametric approaches was conducted for 3 different diagnostic models: severe BP only (BPI); mood disorders (BPI, BPII and major depression); and psychosis (operationally defined by the occurrence of at least 1 episode of hallucinations and/or delusions).

RESULTS AND CONCLUSION

For BPI only, the most interesting result was obtained for chromosome 7p21.1-p22.2 under a recessive model of inheritance (heterogeneity LOD score = 2.80), a region that had previously been linked to BP in a study on Portuguese Island families. For both BPI and mood disorders, nonparametric analyses identified a locus on chromosome 12ct-q14 (nonparametric linkage = 2.55 and 2.35, respectively). This locus has not previously been reported as a candidate region for BP. Additional candidate regions were found on chromosomes 1p22-31 (mood disorders) and 21q21-22 (BPI), 2 loci that have repeatedly been implicated in BP susceptibility. Linkage analysis of psychosis as a phenotype identified candidate regions on chromosomes 2q24-31 and 16p12-q12. The finding on chromosome 16p is noteworthy because the same locus has been implicated by genome-wide association analyses of BP.

Orientation of Schizosaccharomyces POMBE Nonliving Cells under Alternating Uniform and Nonuniform Electric Fields

When nonliving cells of Schizosaccharomyces pombe were subjected to the action of alternating uniform and nonuniform electric fields, two types of orientation were produced. The first one, with its longest axis parallel to the field lines, is similar to that obtained with living cells. The second, perpendicular to the direction of the field, is produced for relatively high frequencies and low conductivities; this probably takes place when the conductivities of the external and internal media (cell cytoplasm) become equal. A mixed cell population is produced in a discrete interval of the parameters used. Our results provide direct evidence that cell alignment does not depend on the physiological state of the cells.

Determinación de producción de metano en caprinos alimentados con dietas con distintos cereales

Se utilizaron tres cabras primíparas de raza Murciano-Granadina de un año y medio de edad y en estado de mantenimiento, con un peso medio de 33,08 ± 2,1 kg, con el objeto de determinar la producción de metano al administrarles dos dietas que difirieron únicamente en el tipo de cereal (grano de cebada o maíz). Se realizaron dos pruebas de digestibilidad consecutivas mediante la administración de las dos dietas. Tras un periodo de adaptación de 7 días se analizó la digestibilidad aparente durante 5 días. La producción de metano (CH4) se determinó por calorimetría indirecta mediante una máscara de circuito abierto adaptada a pequeños rumiantes. El CH4 se midió el día 4 de la prueba de digestibilidad, antes de administrar la ración diaria y se realizaron tres medidas más cada 35 minutos mientras comían. No se observaron diferencias significativas en el consumo de materia seca (con 758 g MS/cabra y día de media), ni entre los coeficientes de digestibilidad de materia seca de las dos dietas (CDMS= 69,2% de media). Durante la comida se observaron diferencias (p

Effect of pasteurization on the bactericidal capacity of human milk

The use of human milk in milk banks requires thermal processing to eliminate microbiological hazards. An evaluation is made of the stability of overall human milk bactericidal capacity following 2 modalities of thermal pasteurization: 63 degrees C/30 minutes and 75 degrees C/15 seconds. Ten milk samples (mature milk) were analyzed. In each sample, the effect of both thermal treatments on bactericidal capacity against Escherichia coli was evaluated in relation to the capacity of fresh milk (control). All the samples analyzed possessed bactericidal capacity. Human milk pasteurization induced a significant loss of this capacity that was more pronounced after high-temperature treatment than after low-temperature processing. Untreated milk, low-pasteurized milk, and high-pasteurized milk yielded a reduction in E. coli growth of 70.10%, 52.27%, and 36.39%, respectively. In conclusion, human milk possesses antimicrobial activity that is lost in part as a result of thermal processing. Such bactericidal capacity is, moreover, better preserved by low-temperature, long-time pasteurization.

Immunological and structural characterization of an epitope from the Trypanosoma cruzi KMP-11 protein

The K1 peptide is an HLA-A*0201-restricted cytotoxic epitope derived from the Trypanosoma cruzi KMP-11 protein, this being the etiological agent of Chagas' disease. This work describes the K1 peptide's secondary structure and its recognition by sera from chagasic patients. Circular dichroism and NMR spectroscopy analysis revealed that the K1 peptide adopts an alpha-helical conformation. Fifty-six percent of individuals had anti-K1 and 86% anti-KMP-11 antibodies by ELISA in the chronic Chagas' group and 28 and 68% in the indeterminate Chagas' group, respectively. By contrast, no reactivity was observed in sera from healthy individuals and tuberculosis patients. Antibody response subclass specificity to the K1 peptide was IgG1 and IgG3. Taken together these results support the idea that the K1 peptide acts as a B-cell-inducer epitope during Chagas' disease.

Prevalence of Salmonella in a poultry slaughterhouse

The prevalence of Salmonella on surfaces, water, and broiler chicken (carcasses, parts, viscera, and spoils) taken from a poultry slaughterhouse located in the south of Brazil was studied. The automated mini-VIDAS system (a variation of the basic enzyme-linked immunosorbent assay) was used to screen for the presence of this microorganism in 615 samples, and the traditional culture method was used in 470 samples. We detected Salmonella in the following sampling points by the VIDAS Salmonella test: transport cages (16.7%), boxes (10%), scalding water (16.7%), chilled water (6.7%), carcass before evisceration (6.7%), carcass after chilling (3.3%), fresh breast (3.3%), fresh leg (10%), frozen wing (13.3%), frozen leg (13.3%), intestines (6.7%), skin of breast and leg (10%), and skin of neck (6.7%). Nevertheless, with the traditional culture method we only detected salmonellae in the following sampling points: scalding water (10%), fresh leg (6.7%), frozen wing (10%), skin of breast and leg (20%), and skin of neck (10%). Finally, 5.4% (33 of 615) of the samples analyzed by the VIDAS Salmonella system were positive, whereas the positive percentage with the traditional method was 2.6% (12 of 470). The results showed that transport cages, scalding water, frozen wing, frozen leg, and skin of breast and leg were the sampling points that demonstrated the greatest prevalence.

L1Tc non-LTR retrotransposons from Trypanosoma cruzi contain a functional viral-like self-cleaving 2A sequence in frame with the active proteins they encode

A comparative analysis of 40 Trypanosoma cruzi L1Tc elements showed that the 2A self-cleaving sequence described in viruses is present in them. Of these elements, 72% maintain the canonical 2A motif (DxExNPGP). A high percentage has a conserved point mutation within the motif that has not been previously described. In vitro and in vivo expression of reporter polyproteins showed that the L1Tc2A sequence is functional. Mutations within certain L1Tc2A sequences affect the efficiency of the cleavage. The data indicate that the L1Tc2A sequence may be influencing the L1Tc enzymatic machinery determining the composition and level of the translated products. The residues located immediately upstream of the 2A consensus sequence increase the cleaving efficiency and appear to stabilize the relative amount of translated products.

Evaluation of IFN-gamma production by CD8 T lymphocytes in response to the K1 peptide from KMP-11 protein in patients infected with Trypanosoma cruzi

The cellular response mediated by MHC class I restricted CD8+ T cells has been shown to be crucial in the control of Chagas disease. The K1 peptide derived from T. cruzi KMP-11 protein has a high binding affinity to the HLA-A*0201 molecule. Nevertheless, it is not known whether this peptide is processed and displayed as an MHC class I epitope during natural infection by T. cruzi. The aim of this study was to evaluate, by ELISPOT assay, the ability of K1 peptide to activate CD8+ T lymphocytes to produce IFN-gamma. Therefore, CD8+ T lymphocytes from 22 HLA-A*0201+ individuals, 12 chronic chagasic patients and 10 uninfected controls, were analysed. The results revealed that two of the chagasic patients had IFN-gamma-secreting CD8+ T cells that were able to respond to K1 peptide with a relative frequency of 110 and 230 per million CD8+ T cells. In contrast, none of HLA-A*0201+ uninfected controls responded to K1 peptide. Responses to HLA-A*0201 restricted peptide from the influenza matrix protein were found in six chagasic patients and four uninfected controls with an average frequency of 175 and 111 cells per million CD8+ T cells, respectively. Moreover, a flow cytometric assay for degranulation showed that chagasic responders had K1-specific cytotoxic CD8+ T cells. It is shown here for the first time that the K1 peptide is efficiently processed, presented and recognized by CD8+ T lymphocytes during the natural course of Chagas disease.

Molecular characterization of the kinetoplastid membrane protein-11 genes from the parasite Trypanosoma rangeli

Trypanosomatids are early divergent parasites which include several species of medical interest. Trypanosoma rangeli is not pathogenic for humans but shows a high immunological cross-reactivity with Trypanosoma cruzi, the causative agent of Chagas' disease that affects more than 17 million people throughout the world. Recent studies have suggested that T. cruzi KMP-11 antigen could be a good candidate for the induction of immunoprotective cytotoxic responses against T. cruzi natural infection. In the present paper the genes coding for the T. rangeli kinetoplastid membrane protein-11 have been characterized. The results show that the locus encoding this protein is formed by 4 gene units measuring 550 nucleotides in length, organized in tandem, and located in different chromosomes in KP1(+) and KP1(-) strains. The gene units are transcribed as a single mRNA of 530 nucleotides in length. Alignment of the T. rangeli KMP-11 deduced amino acid sequence with the homologous KMP-11 protein from T. cruzi revealed an identity of 97%. Interestingly, the T and B cell epitopes of the T. cruzi KMP-11 protein are conserved in the T. rangeli KMP-11 amino acid sequence.

Genomic repetitive DNA elements of Trypanosoma cruzi

Repetitive DNA sequences are interspersed throughout the genomes of mammals and other higher eukaryotes, and represent a substantial portion of the genome. Although it has been generally assumed that the redundant DNA is present only in the complex genomes of high order organisms, over the past few years a number of repetitive DNA sequences have been also detected in the protozoan parasite Trypanosoma cruzi. A compilation of the repetitive DNA sequences found in the T. cruzi genome is here presented by Jose Maria Requena, Manuel Carlos López and Carlos Alonso, who also speculate on their possible origin and functional implications regarding retrotransposition and gene regulation.

Genotoxic differences by sex in nasal epithelium and blood leukocytes in subjects residing in a highly polluted area

We describe differences by sex in genotoxic damage found in a population of medical students exposed to a highly oxidative atmosphere, compared with a control group, measured by the single-cell gel electrophoresis assay and histological changes in nasal epithelium smears. Cells were obtained from the nasal epithelium and blood leukocytes. Higher DNA damage in nasal cells and leukocytes was found in males compared to females and control subjects. The percentage of squamous metaplastic changes in the nasal epithelium was also higher in males compared with females and controls. The co-mutation of normal nasal epithelium by squamous cells might modify its protective function in the nose, increasing the risk of damage to the lower respiratory tract. Although, as medical students, males and females were exposed to the same environment and activity patterns, male genotoxicity damage was higher in control and exposed subjects. More research should be done in order to identify direct or indirect sexual hormone intervention.

Characterization of reverse transcriptase activity of the L1Tc retroelement from Trypanosoma cruzi

The recombinant protein RTL1Tc, encoded by the non-LTR (long terminal repeat) retrotransposon L1Tc from Trypanosoma cruzi, has been shown to have reverse transcriptase (RT) activity using poly(rA)/oligo(dT) and poly(rC)/oligo(dG) homopolymers as template/primers. The optimal RT activity was detected at a concentration of 5 mM Mg2+, pH 8 and between 28 and 37% degrees C. Site-directed mutagenesis in the RT catalytic site proved that substitution of aspartic acid 313 for isoleucine (RT D313IL1Tc) practically abolishes the RT activity of the RTL1Tc protein. RT-polymerase chain reaction assays revealed that the RTL1Tc protein has the ability to use both homologous and heterologous RNA templates. Also, it is shown that the RTL1Tc protein is capable of synthesizing complementary DNA molecules by consecutive switching of the oligo molecule, which the protein uses as a template. This template switching may be involved in the retroelement integration process.

Molecular and immunological characterization of L14 ribosomal protein from Leishmania braziliensis

The isolation and molecular characterization of the gene coding for L14 ribosomal protein from L. braziliensis is described. There are 2 copies of the gene per haploid genome, repeated in a head-to-tail tandem orientation and located in a single chromosome of approximately 950 kb. Northern blot analyses indicate the presence of a single transcript of 0.95 kb which is up-regulated when parasites reach the stationary growth phase. L. braziliensis L14 gene codes for a 175 amino acid long polypeptide showing 75-83% sequence identity with L14 proteins from trypanosomatids and approximately 25% with its counterparts from higher eukaryotic organisms. L14 ribosomal proteins from trypanosomatids and higher eukaryotes share along their molecules a similar distribution pattern of theoretically functional domains. L. braziliensis L14 recombinant protein is not recognized by sera from cutaneous leishmaniasis patients. Immunization of mice with one dose of L14 recombinant protein and a second dose of L14 protein covalently linked to the HSP70 from Trypanosoma cruzi induces a high antibody level against this L14 protein, which is mostly of the IgG2a subtype, as well as a strong increase in splenocyte proliferation index.

Breaking the Non-Responsiveness of C57BL/6 Mice to the Malarial Antigen EB200 - The Role of Carrier and Adjuvant Molecules

Poor immunogenicity and major histocompatibility complex (MHC) restriction of immune responses to certain recombinant proteins or synthetic peptides impose problems in developing effective vaccines. EB200 is one of the vaccine candidate antigens from Plasmodium falciparum, which induces MHC-restricted immune responses in mice of different haplotypes. A way of overcoming this problem is to conjugate the antigen to an immunogenic protein carrier and to use optimal adjuvant substances. We have investigated the carrier effect of glutathione-S-transferase (GST) in CBA and C57BL/6 mice which are high and low responder to EB200, respectively. Our results reveal that the MHC restriction in C57BL/6 mice was broken by the use of GST as a carrier. Studies on the B-cell repertoires in both strains of mice immunized with GST-EB200 by preparing hybridoma cell lines indicate that the B-cell repertoires were similar in both CBA and C57BL/6 mice. However, the antibody affinity and the magnitude of the response were still lower in the low-responder C57BL/6 mice compared with that in CBA even when cholera toxin (CT) was used as adjuvant. To improve the response, the efficacy of various adjuvant substances like alum and Hsp 70 from Trypanosoma cruzi and the combination of various adjuvants was analysed. CT and Hsp 70 together act synergistically and markedly improve the immunogenicity of EB200 by increasing antibody affinity and the magnitude of the responses in C57BL/6 mice, which may be explained by the complementary effect of adjuvants. These results are of importance in the design of efficient vaccines.

Determination of total arsenic levels by hydride generation atomic absorption spectrometry in foods from south-east Spain: estimation of daily dietary intake

The total concentration of arsenic in different foods from south-east Spain was determined by hydride generation atomic absorption spectrometry. Mineralization was carried out with an HNO(3)-HClO(4) mixture in a thermostated sand bath. Arsenic determination was performed by the standard addition method. Analyses of NIST and CBR-CEC reference materials demonstrated the reliability and accuracy of the technique. The highest arsenic levels were found in seafood, cereals, meat and meat by-products. In meat and meat by-products, the total arsenic measured in meat was significantly higher than that in sausages (p<0.05). In cereals, arsenic concentrations in corn and white rice samples were significantly higher (p<0.01) than those measured in wheat by-products. Mean arsenic concentrations in cheese were statistically lower than those in other dairy products (p<0.01). New data have been provided on the total arsenic content of a variety of foods in Spain, which is important for making exposure estimates. The estimated daily intake of total arsenic in the Spanish diet was 221 microg As day(-1).

The endonuclease NL1Tc encoded by the LINE L1Tc from Trypanosoma cruzi protects parasites from daunorubicin DNA damage

In the present paper we show that the overexpression of the NL1Tc protein, encoded by the L1Tc non-LTR retrotransposon from Trypanosoma cruzi, led to a reduction of about 60% of DNA damage caused by daunorubicin treatment. This repair effect is not observed in transfected parasites overexpressing the NL1Tc mutated in the aspartic acid located in the active site of the enzyme. In addition, NL1Tc overexpression protects the parasite from the negative effect that daunorubicin has on parasite's growth rate. Thus, parasites overexpressing NL1Tc show, after treatment with 4 microM of daunorubicin, growth rate two to three times higher than the growth rate observed in treated control parasites transformed with the empty vector or overexpressing the mutated NL1Tc. Likewise, parasites overexpressing the NL1Tc protein and irradiated with a single dose of gamma-radiation (6 or 9 Gy) show higher growth rates than the parasites overexpressing the mutated NL1Tc or the control transfected parasites.

Oral tolerance to dextrin mediated by specific suppressor T-cells induced in the intestinal intraepithelium and their systemic migration

Antigens presented to the immune system through the oral route induce antigen specific secretory IgA and systemic unresponsiveness, termed oral tolerance (OT). We studied the induction of OT towards a diet antigen: dextrin (DEX) in rats that underwent protein deprivation and were further re-fed. Peyer's patches (PP), mesenteric lymph nodes (MLN) and spleen (Sp) cells from protein re-fed (R) rats mediated hyporesponsiveness after transfer into naïve recipient rats. Low numbers of MLN T cells transferred hyporesponsiveness while higher numbers transferred an enhancement of the delayed type hypersensitivity (DTH) reaction. MLN T cells were further separated based on their ability to bind Vicia villosa (VV). MLN VV- T cells, mainly CD8+, mediated hyporesponsiveness and MLN VV+ T cells (CD45RC+ CD4- CD8- cells) abrogated the hyporesponsiveness. Moreover, Sp DEX adherent T cells were mainly CD8+. Intestinal intraepithelial lymphocytes (iIELs) mainly CD8alpha+ gamma(delta)-TCR+ cells also inhibited the DTH response to DEX after transfer. The positive DTH response to another carbohydrate (levan) indicates the specificity of the suppression to dextrin. Therefore, our data indicate that after oral administration of DEX, two different populations of T cells were generated: one found only in the MLN that mediated DTH responses and the other one capable of migrating from the intestinal intraepithelium through PP and MLN to the Sp, mediating systemic tolerance.

Mutations in GCR1 affect SUC2 gene expression in Saccharomyces cerevisiae

Transcription of SUC2, the gene that encodes the cytoplasmic and secreted forms of the enzyme invertase, is controlled by glucose repression and derepression mechanisms in Saccharomyces cerevisiae. Several regulatory factors such as the Mig1p-Tup1p-Ssn6p repressor complex and the Snf1p kinase complex have been identified previously as regulators of SUC2 expression. We show that, in addition to these factors, expression of SUC2 is affected by mutations in the gene GCR1 that encodes the glycolysis regulatory protein Gcr1p. Expression of Suc2-LacZ was not repressed by glucose in gcr1 mutant yeast cells exposed to glucose. Furthermore, secreted invertase activity was constitutively expressed under glucose-repressed and derepressed conditions in gcr1 mutants. DNA gel mobility shift assays and in-vitro DNase I protection experiments mapped a DNA binding site for Gcr1p in the transcriptional control region of the SUC2 gene, next to a previously mapped Mig1p binding site. However, the mechanism by which gcr1 mutations relieve glucose repression remains obscure.

Differential CD86 and CD40 co-stimulatory molecules and cytokine expression pattern induced by Trypanosoma cruzi in APCs from resistant or susceptible mice

Differential aspects of the host immune response generated by Trypanosoma cruzi infection were examined in two different mouse strains, BALB/c (haplotype H2-Kd) which does not overcome the acute phase of the infection and C57BL/6 (haplotype H2-Kb) which survives to the acute phase. After infection an increase in CD3+ T cells was observed in both mouse strains in the peritoneal cavity. However, while the CD3+ T cells from the BALB/c mice showed an increase in the IL-4 cytokine expression level, the same type of cells from the C57BL/6 mice showed an increase in IFN-gamma expression. In addition, only the macrophages from the C57BL/6 mice were activated secreting IL-12 and TNF-alpha and producing, moreover, high levels of nitrites. It was observed that also after parasite infection the expression of macrophage and dendritic cells CD40 and CD86 co-stimulation molecules from the spleen were diminished in BALB/c but not in C57BL/6 mice. In correlation with this observation the macrophages from the spleen of infected BALB/c mice secreted lower concentrations of nitrites than the C57BL/6 mouse cells. Also, the spleen dendritic cells from infected BALB/c mice had a small potential to present alloantigens in contrast to that observed in the infected C57BL/6 mouse cells.

Ascorbic acid in diet supplements: loss in the manufacturing process and storage

The ascorbic acid content was determined in 25 different diet supplements commercially available to the consumer in two pharmaceutical forms (pills and ampoules). These products are widely consumed by several population groups (elderly people, sportsmen, adolescents, children, etc.). High-performance liquid chromatography was used as the analytical technique. The proposed method has been validated with good linearity, reproducibility, recovery and accuracy, and can be used in routine analyses and in quality control. The ascorbic acid content in pills ranged from 15.62 to 50.16 mg/g, and in that ampoules from 2.12 to 8.83 mg/ml. Depending on the dosage rates, these levels would represent approximately 20-50% of the daily dietary intake recommended by the National Research Council. Possible losses in the manufacturing process and stability during storage for 30 days at 40 +/- 2 degrees C without light, were tested. In relation to the ascorbic acid concentrations stated on the labels, a loss of 12.0-21.9% in pills and of 11.7-18.0% in ampoules was detected. In relation to the stability conditions, the losses are of 1.8-24.8% in pills and of 10.4-19.3% in ampoules. The pasteurisation and sterilisation processes produced a mean loss of ascorbic acid in ampoules of 2.1 and 1.4%, respectively. A statistically significant direct correlation was observed between ascorbic acid loss and content in proteins, humidity, ash, and fructose. The influence of the pharmaceutical form was also tested. Data revealed that the control of losses during the manufacturing and commercialisation process of these products is necessary to ensure the intake of vitamin C from these products by the consumer.

Trypanosoma cruzi heat-shock protein-70 kDa,alone or fused to the parasite KMP11 antigen, induces functional maturation of murine dendritic cells

We analyse the effect of Trypanosoma cruzi heat-shock protein-70 (HSP70) on the maturation of murine dendritic cells (DC)generated from bone marrow precursor cells. The results obtained show that HSP70, both alone and fused to the KMP11 antigen, as well as a HSP70 fragment, is capable of maturing murine DC. Mature DC have enhanced expression of IL12, TNF-alpha cytokines, costimulation molecules and activation markers, showing a clear increase in the allostimulatory capacity. These findings suggest that T. cruzi HSP70 may be a very useful vehicle for developing DC-based immunoprophylaxis and therapy against infections.

Liver abscess caused by Ascaris lumbricoides: case report

A case is reported of a woman who lived in a rural area with a chronic illness that consisted of weight loss and abdominal pain in the epigastrium and upper right quadrant. The initial diagnosis was a mass in the liver, which was later, demonstrated, both by direct and histological examination, to be an abscess caused by Ascaris lumbricoides. Eggs of Ascaris lumbricoides and abundant Charcot-Leyden Crystals were found.

In vitro response of v-Ha-ras transgenic mouse lymphocytes after in vivo treatment with alcohol

Oncomouse is a transgenic mouse carrying an activated v-Ha-ras oncogene under the control of the mouse mammary tumor virus promoter. The objective of this paper was to learn if the in vitro secretion of IL-2 and IFN-gamma and the release of sIL-2R by Oncomice splenocytes and thymocytes depended on the presence of the oncogene product, on the in vivo pretreatment with alcohol, or on the in vitro treatment with cocaine or morphine. Oncomice thymocytes released less sIL-2R than FVB thymocytes. Alcohol did not increase sIL-2R release in Oncomice as it did in FVB mice thymocytes. Oncomice thymocytes secreted more IFN-gamma than FVB thymocytes, their secretion was downregulated by in vivo treatment with alcohol, while it was upregulated in FVB thymocytes. IFN-gamma secretion was lower in Oncomice splenocytes from animals receiving alcohol. Oncomice thymocytes and splenocytes responded in a nearly opposite fashion to their FVB counterparts. Therefore, the in vivo treatment with alcohol modified the in vitro response to cocaine or morphine in an oncogene-dependent and -independent manner. Hence, our results further emphasize the role of v-Ha-ras oncogene in defining the host immune response, and of alcohol in modulating such response.

In vitro response of v-Ha-ras transgenic mouse lymphocytes after in vivo treatment with cocaine

Oncomouse is a transgenic mouse carrying an activated v-Ha-ras oncogene under the control of the mouse mammary tumor virus promoter. The objective of this paper was to learn if the in vitro secretion of IL-2 and IFN-gamma and the release of sIL-2R by Oncomice spleen and thymus cells depended on the presence of the oncogene product, on the in vivo pretreatment with cocaine, or on the in vitro treatment with cocaine or morphine. Oncomice thymocytes from different experimental groups released less sIL-2R than FVB thymocytes. Oncomice thymocytes secreted more IFN-gamma than FVB thymocytes. Oncomice thymocytes cultured in the presence of Con A and cocaine showed a diminished release of sIL-2R and a lower secretion of IFN-gamma, a phenomenon not observed in FVB thymocytes. IFN-gamma secretion was lower in Oncomice splenocytes. In general, Oncomice thymocytes and splenocytes responded in a nearly opposite fashion to their FVB counterparts. In this study, the in vitro response to mitogens, cocaine or morphine depended on genetic background and not on the in vivo pretreatment with cocaine. Our results emphasize the role of the v-Ha-ras oncogene in defining the host immune response.

Chromium in basic foods of the Spanish diet: seafood, cereals, vegetables, olive oils and dairy products

In the present study, graphite furnace atomic absorption spectrometry (GFAAS) was used to determine the content of total chromium in some basic foods of the Spanish diet. The seafood samples, vegetables and olive oils were mineralized previously with HNO3 and V2O5. A procedure of slurries with Triton X-100 was applied to dairy products. The temperature-time program was optimized for every type of sample. An assessment of the analytical characteristics of the method verifies their reliability. The content of Cr ranged between 0.004 and 0.079 microg/g in seafood (fresh wt.), from 0.007 to 0.456 microg/g in cereals and vegetables (fresh wt.), between not detectable and 0.625 microg/g in dairy products and between not detectable and 0.040 microg/g in olive oils. The high consumption of these products conditions the fact that they should be significant sources of Cr in the diet.

DNA immunization with Trypanosoma cruzi HSP70 fused to the KMP11 protein elicits a cytotoxic and humoral immune response against the antigen and leads to protection

Murine immunization with Trypanosoma cruzi KMP11-HSP70 fused genes but not the KMP11 gene alone elicited both an immunoglobulin G2a long-lasting humoral immune response against KMP11 protein and activation of CD8+ cytotoxic T lymphocytes specific for two KMP11 peptides containing A2 motifs. Moreover, protection against the parasite challenge was observed after immunization with the chimeric gene.

Daily dietary intake of chromium in southern Spain measured with duplicate diet sampling

We measured daily dietary Cr intake in southern Spain by sampling duplicate diets for seven consecutive days in different population groups. Cr was determined by electrothermal atomization-atomic absorption spectrometry. The samples were mineralized in a digestion block with HNO(3), HClO(4) and V(2)O(5). A total of 161 duplicate diets from twenty-three subjects were analysed, and mean levels of Cr intake ranged from 9.39 to 205.16 microg/d. Mean Cr intake (100 microg/d) was similar to levels found for most other countries, and was within the range recommended by the National Research Council for a safe and adequate daily intake (50-200 microg/d). Chromium intake correlated significantly with energy, protein and carbohydrate intake, and with the daily intake of Zn, Fe, Mg, K, Na, Ca and nicotinic acid in the diets analysed.

Zinc levels in foods from southeastern Spain: relationship to daily dietary intake

The zinc content of 300 food and 79 beverage samples was determined using flame atomic absorption spectrometry. Sample recoveries, repeatability, and analyses of NIST and CBR-CEC reference materials demonstrated the reliability and accuracy of this technique. Mean zinc concentrations varied from 0.02 microg/ml in fresh water to 71.0 microg/g (fresh weight) in pork liver. The daily dietary intake of zinc for inhabitants of southeastern Spain was estimated to be 10.1 mg (5.5, 4.0, 0.5, and 0.1 mg Zn/day per person from foods of animal and vegetable origin, drinks, and other foods, respectively). Zinc levels found in high protein foods (meat, fish, milk products, eggs, dry fruits, cereals and legumes) were significantly higher than those found in food with a low protein content (vegetables, fruits and drinks) (p < 0.001). A significant linear correlation between zinc levels and the corresponding protein content of cereals, legumes and dry fruits was found (r = 0.754, p < 0.005). Zinc concentrations in milk samples were significantly modified by the thermal treatment (p < 0.001), and the skimming (p < 0.05) and calcium enrichment processes (p < 0.001). Shellfish zinc levels were also significantly higher than those measured in fish (p < 0.05). Mean zinc concentrations found in cheese were statistically higher than those determined in the remaining milk products (p < 0.001). Zinc levels measured in distilled beverages were also statistically lower than those found in fermented ones (p < 0.001).

The immunization of A2/K(b) transgenic mice with the KMP11-HSP70 fusion protein induces CTL response against human cells expressing the T. cruzi KMP11 antigen: identification of A2-restricted epitopes

Cytotoxic T lymphocyte response against Jurkat-A2/K(b) cells expressing the T. cruzi KMP11 protein has been evaluated after immunization of C57BL/6-A2/K(b) transgenic mice with the KMP11 and KMP11-HSP70 recombinant proteins. The results show that mice immunized with KMP11 covalently fused to the T. cruzi HSP70 protein, but not mice immunized with KMP11 alone, elicit a CTL response against the Jurkat-A2/K(b) cells expressing the KMP11 protein. The data also show that spleen cells from mice immunized with the fusion protein and stimulated with the K1 peptide induce lysis of both the Jurkat-A2/K(b) cells transfected with the KMP11 coding gene and the Jurkat-A2-K(b) cells pulsed with the K1 peptide. Splenocytes stimulated with the K3 peptide induce lysis of the Jurkat-A2/K(b) cells loaded with the K3 peptide but they do not recognize the target cells expressing the KMP11 protein. Similar results were obtained using lymph node from mice immunized with the peptides. Thus, we believe there are two cytotoxic T cell epitopes restricted to the A2 molecule (K1(KMP11) (4-12) and K3(KMP11) (41-50)) in the KMP11 protein, and suggest that the K1 peptide could be considered an immunodominant antigen whilst the K3 peptide may be regarded as a cryptic epitope. The fact that the CTL lines induced in B6-A2/K(b) mice recognize human cells expressing KMP11 protein, indicates that the KMP11 antigen fused to HSP70 could be a good candidate for the induction of immunoprotective cytotoxic responses against T. cruzi natural infection.

Estimation of chromium bioavailability from the diet by an in vitro method

An in vitro method was used to study the dialysable fraction of chromium (Cr) from the diet which simulates human gastric and intestinal digestion. The percentage of dialysed Cr was used to assess the bioavailability. The duplicate diet approach was used to obtain ten different sets of samples each representative of the normal diet consumed in southern Spain. In each case triplicate analysis of Cr was carried out by electrothermal atomization-atomic absorption spectrometry in acid-mineralized samples. The Cr dietary intake ranged from 16 to 117 microg/day, and the dialysable Cr fraction ranged from 0.4% to 1.6%. The Cr absorption was higher for low levels of daily dietary intake of Cr (< 40 microg) than for levels of 40-80 microg; for high levels (> 80 microg) there was an increase in the dialysable fraction. The energy and nutrient intake of these diets was also evaluated.

DNA breakage due to metronidazole treatment

The mutagenicity of metronidazole [1-(hidroxyethyl)-2-methyl-5-nitroimidazole] (MTZ) has been shown in different prokaryotic systems. However, data on human cells are still contradictory. In this study DNA damage was determined by the single cell gel electrophoresis (SCGE) assay, in lymphocytes from 10 healthy subjects treated with therapeutic doses of this drug. Samples were obtained before treatment, as well as 1 and 15 days after ending treatment. Results showed a significant increase of DNA strand breaks 1 day after ending treatment, although, an inverse correlation between the amount of DNA damage and plasma concentrations of MTZ was obtained. Thus, the observed damage may be induced by some MTZ metabolite rather than by the parent drug. Interestingly, the amount of DNA damage returned to basal levels 15 days after ending treatment, except in two individuals. This persistent damage should be further investigated.

Myxobolus sp., another opportunistic parasite in immunosuppressed patients?

During a study of intestinal parasitic infections in human immunodeficiency virus-positive patients, a parasite belonging to the phylum Myxozoa, recently described from human samples, was identified in one sample. When this parasite was stained by the modified Ziehl-Neelsen staining method, the features of the spores were identified: they were pyriform in shape, had thick walls, and had one suture and two polar capsules, with each one having four or five coils. The suture and two polar capsules were observed with the chromotrope-modified stain. The number of stools passed was more than 30 per day, but oocysts of Isospora belli were also found. Upon reexamination of some formalin- or merthiolate-iodine-formaldehyde-preserved samples an identical parasite was found in another sample from a patient presenting with diarrhea. Strongyloides stercoralis larvae and eggs of Hymenolepis nana and Ascaris lumbricoides were also found in this sample. Given that both patients were also infected with other pathogens that cause diarrhea, the possible pathogenic role of this parasite could not be established. The probable route of infection also could not be established.

Mapping of the antigenic determinants of the T. cruzi kinetoplastid membrane protein-11. Identification of a linear epitope specifically recognized by human Chagasic sera

The high variability among strains and isolates of Trypanosoma cruzi and the existence of shared antigenic determinants with other pathogens, particularly with members of the Leishmania genus make difficult the specific diagnosis of Chagas' disease. The data reported in this paper show that the T. cruzi KMP11 protein is an immunodominant antigen highly recognized by the sera from chagasic and leishmaniasis patients. By the use of amino- and carboxyl-terminal truncated KMP11 recombinant proteins and synthetic peptides, evidence is provided that while the sera from chagasic patients recognize linear peptides the sera from patients with visceral leishmaniasis must be predominantly directed against conformational epitopes. We found that a particular linear determinant, located in the carboxyl-terminal region of the protein, is recognized with high specificity and sensitivity only by sera from Chagas' disease patients, suggesting it could be a good candidate for differential serodiagnosis of Chagas' disease.