MUC1 polymorphism in relation to susceptibility to Helicobacter pylori gastritis.

The gene MUC1 encodes a transmembrane mucin glycoprotein that is expressed on the apical surface of most epithelia and is aberrantly expressed in cancer. MUC1 contains an extended domain of tandemly repeated (TR) amino-acid sequence, which acts as the backbone for a large amount of O-linked glycosylation, and which varies in length and sequence in different alleles. Previous studies on MUC1 tandem repeat variation in patients with gastritis (Vinall et al, 2002) and gastric cancer (Carvalho et al, 1997) showed an overrepresentation of short TR alleles in the patient groups when compared with normal controls. The major aim of this thesis is to pursue this observation further. MUC1 allele and three locus haplotype frequencies were compared in 3 populations of different ancestry, from UK, Nigeria and Portugal, which show dramatic differences in gastric disease incidence in patients with gastric disease, patients with other gastrointestinal disease as well as associated controls. There were differences between the Nigerians and unselected European control groups, but there was no significant difference between the groups collected in London and Porto. Analysis of the gastric disease groups showed an over-representation of a particular MUC1 haplotype. A search was made, by sequencing and using a bioinformatics approach, for additional polymorphic markers within and surrounding the MUC1 gene, that might act as convenient markers for future disease association studies. Patterns of Linkage Disequilibrium were established across a 600Kb genomic region containing MUC1 using information in the HapMap resource and this information was used to assist in the selection of the single nucleotide polymorphisms (SNPs) within a 70Kb region to test on disease groups. During the course of this thesis work, a second UK cohort of patients and controls was collected and characterised and a replication study attempted. DNA samples from a total of 154 Northern Europeans classified as H. pylori gastritis (n=33), former H. pylori gastritis (n=44), No H. pylori gastritis (n=18) and normal (n=59). Examination of the MUC1 polymorphisms failed to show over-representation, in the H. pylori gastritis group, of the same haplotype found in the first gastritis cohort. The extended 70Kb haplotypes showed the expected association in the first cohort but no significant differences in the second cohort. However, in the population overall, it was noteworthy that there is a very high frequency haplogroup containing long tandem repeat arrays and this was somewhat lower in frequency in both H. pylori gastritis groups

Bacteriocin production by spray-dried lactic acid bacteria

Cell survival and antagonistic activity against Listeria innocua, Listeria monocytogenes and Staphylococcus aureus were investigated after spray-drying three bacteriocin-producing strains of lactic acid bacteria: Carnobacterium divergens, Lactobacillus salivarius and Lactobacillus sakei

GNSS/LiDAR-Based Navigation of an Aerial Robot in Sparse Forests

Autonomous navigation of unmanned vehicles in forests is a challenging task. In such environments, due to the canopies of the trees, information from Global Navigation Satellite Systems (GNSS) can be degraded or even unavailable. Also, because of the large number of obstacles, a previous detailed map of the environment is not practical. In this paper, we solve the complete navigation problem of an aerial robot in a sparse forest, where there is enough space for the flight and the GNSS signals can be sporadically detected. For localization, we propose a state estimator that merges information from GNSS, Attitude and Heading Reference Systems (AHRS), and odometry based on Light Detection and Ranging (LiDAR) sensors. In our LiDAR-based odometry solution, the trunks of the trees are used in a feature-based scan matching algorithm to estimate the relative movement of the vehicle. Our method employs a robust adaptive fusion algorithm based on the unscented Kalman filter. For motion control, we adopt a strategy that integrates a vector field, used to impose the main direction of the movement for the robot, with an optimal probabilistic planner, which is responsible for obstacle avoidance. Experiments with a quadrotor equipped with a planar LiDAR in an actual forest environment is used to illustrate the effectiveness of our approach

Random amplified polymorphic DNA profiles as a tool for the characterization of Brazilian keratitis isolates of the genus Acanthamoeba

The genus Acanthamoeba comprises free-living amebae identified as opportunistic pathogens of humans and other animal species. Morphological, biochemical and molecular approaches have shown wide genetic diversity within the genus. In an attempt to determine the genetic relatedness among isolates of Acanthamoeba we analyzed randomly amplified polymorphic DNA (RAPD) profiles of 11 Brazilian isolates from cases of human keratitis and 8 American type culture collection (ATCC) reference strains. We found that ATCC strains belonging to the same species present polymorphic RAPD profiles whereas strains of different species show very similar profiles. Although most Brazilian isolates could not be assigned with certainty to any of the reference species, they could be clustered according to pattern similarities. The results show that RAPD analysis is a useful tool for the rapid characterization of new isolates and the assessment of genetic relatedness of Acanthamoeba spp. A comparison between RAPD analyses and morphological characteristics of cyst stages is also discussed.Universidade de São PauloUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Effect of various growth media upon survival during storage of freeze-dried Enterococcus faecalis and Enterococcus durans

The effects of three different growth media (MRS, M17 and Lee’s) on survival during freeze-drying and subsequent storage of six strains of Enterococcus faecalis and two strains of E. durans were investigated. Methods and Results: Distinct Enterococcus spp. strains were grown on M17, MRS and Lee’s broth, freeze-dried and stored at 20 C in air under darkness. At regular intervals throughout storage, freeze-dried samples were rehydrated and then plated on M17 agar. Conclusions: A higher survival rate during storage of dried E. durans was obtained when growth occurred in MRS. The same effect was not observed, however, for the majority of E. faecalis strains, which clearly survived better in the dried state when this organism had been grown in M17 or Lee’s medium. Significance and Impact of Study: The survival of the dried Enterococcus spp. tested during storage was shown to be strain-specific and dependent on the growth medium

Bone Mineral Density in Healthy Female Adolescents According to Age, Bone Age and Pubertal Breast Stage

This study was designed to evaluate bone mineral density (BMD) in healthy female Brazilian adolescents in five groups looking at chronological age, bone age, and pubertal breast stage, and determining BMD behavior for each classification. Seventy-two healthy female adolescents aged between 10 to 20 incomplete years were divided into five groups and evaluated for calcium intake, weight, height, body mass index (BMI), pubertal breast stage, bone age, and BMD. Bone mass was measured by bone densitometry (DXA) in lumbar spine and proximal femur regions, and the total body. BMI was estimated by Quetelet index. Breast development was assessed by Tanner's criteria and skeletal maturity by bone age. BMD comparison according to chronologic and bone age, and breast development were analyzed by Anova, with Scheffe's test used to find significant differences between groups at P≤0.05. BMD (g·cm(-2)) increased in all studied regions as age advanced, indicating differences from the ages of 13 to 14 years. This group differed to the 10 and 11 to 12 years old groups for lumbar spine BMD (0.865±0.127 vs 0.672±0.082 and 0.689±0.083, respectively) and in girls at pubertal development stage B3, lumbar spine BMD differed from B5 (0.709±0.073 vs 0.936±0.130) and whole body BMD differed from B4 and B5 (0.867±0.056 vs 0.977±0.086 and 1.040±0.080, respectively). Bone mineralization increased in the B3 breast maturity group, and the critical years for bone mass acquisition were between 13 and 14 years of age for all sites evaluated by densitometry

The immunogenetic impact of European colonization in the Americas

PUBLISHED 05 August 2022The introduction of pathogens originating from Eurasia into the Americas during early European contact has been associated with high mortality rates among Indigenous peoples, likely contributing to their historical and precipitous population decline. However, the biological impacts of imported infectious diseases and resulting epidemics, especially in terms of pathogenic effects on the Indigenous immunity, remain poorly understood and highly contentious to this day. Here, we examine multidisciplinary evidence underpinning colonization-related immune genetic change, providing contextualization from anthropological studies, paleomicrobiological evidence of contrasting host-pathogen coevolutionary histories, and the timings of disease emergence. We further summarize current studies examining genetic signals reflecting post-contact Indigenous population bottlenecks, admixture with European and other populations, and the putative effects of natural selection, with a focus on ancient DNA studies and immunity-related findings. Considering current genetic evidence, together with a population genetics theoretical approach, we show that post-contact Indigenous immune adaptation, possibly influenced by selection exerted by introduced pathogens, is highly complex and likely to be affected by multifactorial causes. Disentangling putative adaptive signals from those of genetic drift thus remains a significant challenge, highlighting the need for the implementation of population genetic approaches that model the short time spans and complex demographic histories under consideration. This review adds to current understandings of post-contact immunity evolution in Indigenous peoples of America, with important implications for bettering our understanding of human adaptation in the face of emerging infectious diseases.Evelyn Jane Collen, Angad Singh Johar, João C. Teixeira and Bastien Llama

Nematodes Affecting Potato and Sustainable Practices for Their Management

Plant-parasitic nematodes are a significant factor limiting potato production and tuber quality in several regions where potato is produced. Overall, parasitic nematodes alone cause an estimated annual crop loss of $ 78 billion worldwide and an average crop yield loss of 10–15%. As a result, sustainable food production and food security are directly impacted by pests and diseases. Degrading land use with monocultures and unsustainable cropping practices have intensified problems associated with plant pathogens. Proper identification of nematode species and isolates is crucial to choose effective and sustainable management strategies for nematode infection. Several nematode species have been reported associated with potato. Among those, the potato cyst nematodes Globodera rostochiensis and G. pallida, the root-knot nematode Meloidogyne spp., the root lesion nematode Pratylenchus spp., the potato rot nematode Ditylenchus destructor and the false root-knot nematode Nacobbus aberrans are major species limiting potato yield and leading to poor tuber quality. Here, we report a literature review on the biology, symptoms, damage and control methods used for these nematode species