Effect of erythrocyte transfusion on the circulation of Guérin carcinoma-bearing rats

In Guérin carcinoma-bearing rats during tumour growth cardiac output and blood flow to several organs were increased whereas TPR, vascular resistance of some regions and haematocrit gradually decreased. In response to erythrocyte transfusion the anaemia of tumour-bearing rats was considerably improved or corrected, however, the parameters for systemic and regional circulation were only partially restored. We presume that the circulatory "hyperkinesis" of tumour-bearing rats is partly due to the anaemia but also an unknown factor must be considered. The blood perfusion of the Guérin carcinoma was not affected by the erythrocyte transfusion thus it is feasible that the tumour vasculature is maximally dilated even with a normal haematocrit of the host.     

Color and Shape Discrimination in the Stingless Bee Scaptotrigona mexicana Guérin (Hymenoptera, Apidae)

To increase our understanding in bee vision ecology, we investigated the color and shape discrimination performance of the stingless bee Scaptotrigona mexicana Guérin. Our main goal was to describe the choice behavior of experienced foragers over time, trying to understand to what extent color and shape stimuli (separately tested) aid them to choose the rewarding option, in the presence of distracting, unrewarding stimuli. Single foragers were trained to collect sucrose solution from a target plate. Afterwards, one distracting, unrewarding plate was placed besides the target plate and eight choices were recorded. Our results showed that both color and shape stimuli assisted efficiently the trained foragers in locating the target plate. However, foragers chose significantly more often the target plate in the color experiments than in the shape experiments. In conclusion, in our experimental setup, color was of better assistance to the foragers of S. mexicana than shape to choose their rewards. This is the first study in which it is demonstrated that the choice performance over time in a stingless bee depends upon the characteristics of the resource, such as shape and color.     

Early appearing gamma/delta-bearing T cells during infection with Calmétte Guérin bacillus.

To search for a potential role of TCR gamma/delta T cells in host-defense against mycobacterial infection, we analyzed the kinetics, repertoire, specificity, and cytokine production of gamma/delta T cells in the peritoneal exudate cells (PEC), lymph node (LN) cells and spleen cells during an i.p. infection with a sublethal dose (5 x 10(5) of viable Bacillus Calmétte-Guérin (BCG) in mice. In the PEC on day 7 after infection, approximately 26% of the CD3+ cells were CD4-CD8-, most of which expressed TCR gamma/delta on their surface. However, the PEC on day 28 contained an increased number of alpha/beta T cells that were CD4+8- or CD4-8+ and the proportion of gamma/delta T cells in the PEC reciprocally decreased to 18% of the CD3+ cells. The kinetics of gamma/delta and alpha/beta T cells in the LN during BCG infection showed in much the same pattern as that seen in the PEC. When purified CD4-CD8- cells in the LN on day 7 after BCG infection were cultured with sonicated BCG lysate, PPD derived from Mycobacterium tuberculosis or recombinant 65 kDa heat shock protein derived from Mycobacterium bovis, the gamma/delta T cells on this stage significantly proliferated and secreted IL-2 in response to sonicated BCG lysate and PPD but not to 65 kDa heat shock protein. V gene segment usage analysis with PCR method revealed that purified protein derivative-reactive gamma/delta T cells preferentially used V gamma 1/2/V delta 6, whereas gamma/delta T cells polyclonally expanded in response to the BCG lysate. These results suggest that gamma/delta T cells specific for mycobacterial antigens preceding alpha/beta T cells in appearance during infection may serve as a first line of defense against mycobacterial infection.     

Mating behavior of the coffee leaf-miner Leucoptera coffeella (Guérin-Mèneville) (Lepidoptera: Lyonetiidae)

Despite the importance of Leucoptera coffeella (Guérin-Mèneville) in coffee production worldwide, there is a lack of information on its reproductive biology. This knowledge will help in mass rearing, as well as support the development of behavioral control techniques for this insect. The purpose of the study was to determine the periodicity of mating and male capture and describe the mating behavior L. coffeella. In laboratory, we observed the periodicity of mating with virgin couples of different ages, zero to five days after emergence. Male activity was studied in a 0.7 ha coffee plantation, cv. Catuaí, where Delta traps were installed at 0.5 m above ground, using either virgin females or rubber septa lured with the synthetic sex pheromone. The sequence of mating behavior was studied by making visual observations and recorded of pairs placed on individual plastic tubes. Mating occurred between 4h and 6h of photophase, when the highest frequencies involved pairs with ages of one and three days after emergence, with peak of mating occurring in 5th hour of photophase. The young or old pairs showed significantly copulation frequency and the peak of matings advance in 1h. The highest male capture occurred at 12p.m. and 13 p.m. by traps with virgin females or traps with synthetic sex pheromone lures, respectively. L. coffeella is one insect with diurnal mating and the mating behavior was not different from what is know for other Lepidoptera species.     

Growth inhibition of HeLa cell by internalization of Mycobacterium bovis Bacillus Calmette-Guérin (BCG) Tokyo

Background  

Intravesical BCG immunotherapy is effective for preventing recurrence and progression in none muscle-invasive bladder cancer but the dosing schedule and duration of treatment remain empirical. The mechanisms by which intravesical BCG treatment mediates antitumor activity are currently poorly understood.     

Cytokine gene polymorphisms can alter the effect of Bacillus Calmette-Guérin (BCG) immunotherapy

Various types of cancer are more frequent in men than women, and bladder cancer is one of the most common of these. Intravesical instillation of Bacillus Calmette-Guérin (BCG) after transurethral resection is the most effective treatment for superficial bladder cancers. The main aim of this study was to investigate for possible links between cytokine gene polymorphisms and different outcomes after BCG immunotherapy. Sixty patients who had been diagnosed with transitional cell cancer were investigated. All genotyping experiments were performed using polymerase chain reaction sequence-specific primers and a commercially available kit. The genes investigated were those that code for interleukin (IL)-1alpha, IL-1beta, IL-1R, IL-1RA, IL-4RA, IL-2, IL-4, IL-6, IL-10, IL-12, interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), and tumor necrosis factor-alpha (TNF-alpha). Analyses of the data identified TGF-beta codon 25 GG (92.85% vs. 64.44%, p=0.04, OR=7.17), IL-4 -1098 GG (16.6% vs. 0.0%, p=0.05, OR=18.33), IL-10 -1082 GG (28.5% vs. 6.8%, p=0.05, OR=5.47), and IL-10 -1082 GCC/GCC (28.57% vs. 4.5%, p=0.025, OR=8.4) polymorphisms as risk factors for progression of bladder cancer.     

The impact of maternal infection with Mycobacterium tuberculosis on the infant response to bacille Calmette–Guérin immunization

Bacille Calmette–Guérin (BCG) immunization provides variable protection against tuberculosis. Prenatal antigen exposure may have lifelong effects on responses to related antigens and pathogens. We therefore hypothesized that maternal latent Mycobacterium tuberculosis infection (LTBI) influences infant responses to BCG immunization at birth. We measured antibody (n = 53) and cellular (n = 31) responses to M. tuberculosis purified protein derivative (PPD) in infants of mothers with and without LTBI, in cord blood and at one and six weeks after BCG. The concentrations of PPD-specific antibodies declined between birth (median [interquartile range (IQR)]) 5600 ng ml⁻¹ [3300–11 050] in cord blood) and six weeks (0.00 ng ml⁻¹ [0–288]). Frequencies of PPD-specific IFN-γ-expressing CD4⁺T cells increased at one week and declined between one and six weeks (p = 0.031). Frequencies of IL-2- and TNF-α-expressing PPD-specific CD4⁺T cells increased between one and six weeks (p = 0.019, p = 0.009, respectively). At one week, the frequency of PPD-specific CD4⁺T cells expressing any of the three cytokines, combined, was lower among infants of mothers with LTBI, in crude analyses (p = 0.002) and after adjusting for confounders (mean difference, 95% CI −0.041% (−0.082, −0.001)). In conclusion, maternal LTBI was associated with lower infant anti-mycobacterial T-cell responses immediately following BCG immunization. These findings are being explored further in a larger study.     

Environmental and seasonal variation in the diet of Elachistocleis bicolor (Guérin-Méneville 1838) (Anura: Microhylidae) from northern Uruguay

We studied the diet of Elachistocleis bicolor captured in pine, eucalypt, and unmodified environments in Uruguay. Comparisons between seasons (active, inactive) and among three environments (pine, eucalypt, unmodified), were made using rarefaction analyses, importance indices, and non-parametric tests. Elachistocleis bicolor has a specialized diet composed mainly of Pheidole and Solenopsis ants and termites. The diet of E. bicolor includes a high number of prey per individual, suggesting active search as a foraging strategy. The consumption of myrmicine ants (i.e., Solenopsis) represents a source for potential toxic skin secretions that in E. bicolor may be used to avoid being attacked in the ant nests used for shelter during aestivation, as occurs in the microhylid Phrynomantis microps. Diets in forested environments were richer in both periods, which may reflect the colonization of opportunistic ant species in these environments. Ants were more important in the eucalyptus plantations, particularly in the inactive period, whereas termites were more important in the pine plantations mainly in the inactive period. These environmental and seasonal differences in diet are consistent with the temperature and humidity tolerances of ants and termites, which are the main prey of E. bicolor.