Occurrence of co-infection by Leishmania (Leishmania) chagasi and Trypanosoma (Trypanozoon) evansi in a dog in the state of Mato Grosso do Sul, Brazil

A natural case of co-infection by Leishmania and Trypanosoma is reported in a dog (Canis familiaris) in south- western state of Mato Grosso do Sul, Brazil. Both amastigote and trypomastigote forms were observed after Giemsa staining of cytological preparations of the dog's bone marrow aspirate. No parasite was detected using medium culture inoculation of the sample. DNA obtained from the bone marrow aspirate sample and from the blood buffy coat was submitted to polymerase chain reaction (PCR) with a set of rDNA-based primers S4/S12. The nucleotide sequence of the PCR product was identical to that of Trypanosoma (Trypanozoon) evansi. The S4/S12 PCR was then used as template in a nested-PCR using a specific Leishmania set S17/S18 as primers, to explain the amastigote forms. The nucleotide sequence of the new PCR product was identical to that of Leishmania (Leishmania) chagasi. This case, as far as we know, is the first report of a dog co-infected with these parasites, suggesting that besides L. (L.) chagasi, the natural transmission of T. (T.) evansi occurs in the area under study.     

Effects of growth regulators and genotypes on pyrethrum <Emphasis Type="Italic">In vitro</Emphasis>

Summary The effects of growth regulators on culture response of different pyrethrum (Chrysanthemum cinerariaefolium Vis.) genotypes were investigated. In the genotype Sb/66/107, the presence of 2,4-dichorophenoxyacetic acid (2,4-D) at 2 mgl⁻¹ promoted growth of callus, whereas benzyladenine and 1-naphthaleneacetic acid had no effect. Callus growth was also affected by the 2,4-D, ranging from 0.5 mgl⁻¹ for genotype Marwanga to 3.0 mgl⁻¹ for Ks/75/336. Among the genotypes, shoots were regenerated from calluses of Sb/66/107, 4331, Marwanga, and MA/70/1013.     

Microtubule regulation of N-methyl-D-aspartate receptor channels in neurons

N-Methyl-D-aspartate (NMDA) receptors (NMDARs), which play a key role in synaptic plasticity, are dynamically regulated by many signaling molecules and scaffolding proteins. Although actin cytoskeleton has been implicated in regulating NMDAR stability in synaptic membrane, the role of microtubules in regulating NMDAR trafficking and function is largely unclear. Here we show that microtubule-depolymerizing agents inhibited NMDA receptor-mediated ionic and synaptic currents in cortical pyramidal neurons. This effect was Ca(2+)-independent, required GTP, and was more prominent in the presence of high NMDA concentrations. The NR2B subunit-containing NMDA receptor was the primary target of microtubules. The effect of microtubule depolymerizers on NMDAR currents was blocked by cellular knockdown of the kinesin motor protein KIF17, which transports NR2B-containing vesicles along microtubule in neuronal dendrites. Neuromodulators that can stabilize microtubules, such as brain-derived neurotrophic factor, significantly attenuated the microtubule depolymerizer-induced reduction of NMDAR currents. Moreover, immunocytochemical studies show that microtubule depolymerizers decreased the number of surface NR2B subunits on dendrites, which was prevented by the microtubule stabilizer. Taken together, these results suggest that interfering with microtubule assembly suppresses NMDAR function through a mechanism dependent on kinesin-based dendritic transport of NMDA receptors.     

Stress hormones: a link between maternal condition and sex-biased reproductive investment

In species where offspring fitness is sex-specifically influenced by maternal reproductive condition, sex allocation theory predicts that poor-quality mothers should invest in the evolutionarily less expensive sex. Despite an accumulation of evidence that mothers can sex-specifically modulate investment in offspring in relation to maternal quality, few mechanisms have been proposed as to how this is achieved. We explored a hormonal mechanism for sex-biased maternal investment by measuring and experimentally manipulating baseline levels of the stress hormone corticosterone in laying wild female European starlings (Sturnus vulgaris) and examining effects on sex ratio and sex-specific offspring phenotype adjustment. Here we show that baseline plasma corticosterone is negatively correlated with energetic body condition in laying starlings, and subsequent experimental elevation of maternal baseline plasma corticosterone increased yolk corticosterone without altering maternal condition or egg quality per se. Hormonal elevation resulted in the following: female-biased hatching sex ratios (caused by elevated male embryonic mortality), lighter male offspring at hatching (which subsequently grew more slowly during postnatal development), and lower cell-mediated immune (phytohemagglutinin) responses in males compared with control-born males; female offspring were unaffected by the manipulation in both years of the study. Elevated maternal corticosterone therefore resulted in a sex-biased adjustment of offspring quality favorable to female offspring via both a sex ratio bias and a modulation of male phenotype at hatching. In birds, deposition of yolk corticosterone may benefit mothers by acting as a bet-hedging strategy in stochastic environments where the correlation between environmental cues at laying (and therefore potentially maternal condition) and conditions during chick-rearing might be low and unpredictable. Together with recent studies in other vertebrate taxa, these results suggest that maternal stress hormones provide a mechanistic link between maternal quality and sex-biased maternal investment in offspring.     

Regional differences in awareness and attitudes regarding genetic testing for disease risk and ancestry

Little is known about the lay public’s awareness and attitudes concerning genetic testing and what factors influence their perspectives. The existing literature focuses mainly on ethnic and socioeconomic differences; however, here we focus on how awareness and attitudes regarding genetic testing differ by geographical regions in the US. We compared awareness and attitudes concerning genetic testing for disease risk and ancestry among 452 adults (41% Black and 67% female) in four major US cities, Norman, OK; Cincinnati, OH; Harlem, NY; and Washington, DC; prior to their participation in genetic ancestry testing. The OK participants reported more detail about their personal ancestries (p = 0.02) and valued ancestry testing over disease testing more than all other sites (p < 0.01). The NY participants were more likely than other sites to seek genetic testing for disease (p = 0.01) and to see benefit in finding out more about one’s ancestry (p = 0.02), while the DC participants reported reading and hearing more about genetic testing for African ancestry than all other sites (p < 0.01). These site differences were not better accounted for by sex, age, education, self-reported ethnicity, religion, or previous experience with genetic testing/counseling. Regional differences in awareness and attitudes transcend traditional demographic predictors, such as ethnicity, age and education. Local sociocultural factors, more than ethnicity and socioeconomic status, may influence the public’s awareness and belief systems, particularly with respect to genetics.     

Impact of HLA-B alleles, epitope binding affinity, functional avidity, and viral coinfection on the immunodominance of virus-specific CTL responses

Immunodominance is variably used to describe either the most frequently detectable response among tested individuals or the strongest response within a single individual, yet factors determining either inter- or intraindividual immunodominance are still poorly understood. More than 90 individuals were tested against 184 HIV- and 92 EBV-derived, previously defined CTL epitopes. The data show that HLA-B-restricted epitopes were significantly more frequently recognized than HLA-A- or HLA-C-restricted epitopes. HLA-B-restricted epitopes also induced responses of higher magnitude than did either HLA-A- or HLA-C-restricted epitopes, although this comparison only reached statistical significance for EBV epitopes. For both viruses, the magnitude and frequency of recognition were correlated with each other, but not with the epitope binding affinity to the restricting HLA allele. The presence or absence of HIV coinfection did not impact EBV epitope immunodominance patterns significantly. Peptide titration studies showed that the magnitude of responses was associated with high functional avidity, requiring low concentration of cognate peptide to respond in in vitro assays. The data support the important role of HLA-B alleles in antiviral immunity and afford a better understanding of the factors contributing to inter- and intraindividual immunodominance.     

Determination of the period for establishment of a liver network echogenic pattern in Schistosoma japonicum infection

Schistosomiasis is caused by infection with Schistosoma haematobium, S. mansoni, S. japonicum, or S. mekongi. S. japonicum infection results in liver cirrhosis at the final stage. A "network" (NW) echogenic pattern on hepatic ultrasonography appears to be specific to S. japonicum infection. The principal aim of the present study was to determine the exact year(s) or even month(s) required for the establishment of the liver NW echogenic pattern from the initial infection in young patients with schistosomiasis japonica since there are few data on this important point. We conducted yearly ultrasonographic, serologic, coprologic, and physical examinations of schistosomiasis patients in the Philippines from 1996 up to the present. During that period, the total number of patients examined was approximately 2,000, among whom we selected 2 patients for determination of the duration required for NW establishment, when they were 10 years old. Although the exact time of initial exposure to schistosomes cannot be determined, the duration for the establishment of NW was definitively confirmed in patient no. 1 to be between 19-24 months based on the results of serologic and coprologic examinations. For patient no. 2, the circumstantial evidence suggested that the establishment of a NW might require 5 to 6 years at maximum. To the best of our knowledge, this is the first evidence-based report on the determination of the period required for the establishment of a liver NW echogenic pattern in S. japonicum infection in the Philippines.     

Abundance of Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae) and urban transmission of visceral leishmaniasis in Campo Grande, state of Mato Grosso do Sul, Brazil

The outspread and urbanization of visceral leishmaniasis (VL) in Campo Grande, state of Mato Grosso do Sul, lead us to undertake the present study over diversity and abundance of sand flies in the urban area to compare with previous search carried out during 1999/2000, before the identification of the disease in the human population.The captures were carried out with automatic light traps, weekly, from February 2004 to February 2005 on three sites including a forested area (Zé Pereira), two peridomicilies (shelters of domestic animals and cultivation areas), and intradomicilie. In the present study 110 collections were obtained during 13 months for 1320 h of collections, resulting in 5004 specimens, 3649 males and 1355 females belonging to the 20 following species: Brumptomyia avellari, Brumptomyia sp., Bichromomyia flaviscutellata, Evandromyia lenti, E. termitophila, E. cortelezzii, E. borrouli, Lutzomyia sp., L. longipalpis, Micropygomyia quinquefer, N. antunesi, N. whitmani, Pintomyia christenseni, Pi. damascenoi, Psathyromyia aragaoi, Ps. campograndensis, Ps. hermanlenti, Ps. shannoni, Pychodopygus claustrei, and Sciopemyia sordellii. L. longipalpis was the most abundant species in the anthropic environment with 92.22% of the captures. This shows an increase of sixty times in the density of L. longipalpis compared to the last sand fly evaluation in 1999/2000. The high density of L. longipalpis in Campo Grande is the main factor of risk in transmission of the disease to human in the urban area. The capture of N. antunesi, typical specie from Amazonian region, in Mato Grosso do Sul is reported for the first time.     

Surface roughness of denture base and reline materials after disinfection by immersion in chlorhexidine or microwave irradiation

doi: 10.1111/j.1741‐2358.2011.00484.x
Surface roughness of denture base and reline materials after disinfection by immersion in chlorhexidine or microwave irradiation Background: This study evaluated the effect of disinfection by immersion and microwave irradiation on the roughness of one denture base resin (Lucitone‐L) and five relining materials, three hard (Tokuyama Rebase II‐TR, New Truliner‐NT, Ufigel Hard‐UH) and two resilient (Trusoft‐T, Sofreliner‐S). Methods: Fifty specimens were made and divided into groups: CL2 specimens were brushed with 4% chlorhexidine (1 min), immersed in the same solution (10 min) and immersed in water (3 min); MW2 specimens were immersed in water and microwave irradiated (650W; 6 min); CL2 and MW2 specimens were disinfected twice; CL7 and MW7 specimens were submitted to seven cycles using chlorhexidine or microwave irradiation, respectively; W specimens were not disinfected and remained in water (37°C; 7 days). Results: Results were statistically analysed (p = 0.05) and revealed that, at baseline, the highest mean value was observed for T (p < 0.001). Material NT showed increase in roughness after the first (p = 0.003), second (p = 0.001), seventh (p = 0.000) cycles of microwave disinfection and after 7 days of immersion in water (p = 0.033). Conclusions: Resilient liner S presented significant increase in roughness after the second cycle of disinfection with chlorhexidine (p = 0.003). Material T exhibited significantly decreased roughness in group W (p = 0.010), while microwaving produced severe alterations on its surface.