Phylogenomics and analysis of shared genes suggest a single transition to mutualism in Wolbachia of nematodes

Wolbachia, endosymbiotic bacteria of the order Rickettsiales, are widespread in arthropods but also present in nematodes. In arthropods, A and B supergroup Wolbachia are generally associated with distortion of host reproduction. In filarial nematodes, including some human parasites, multiple lines of experimental evidence indicate that C and D supergroup Wolbachia are essential for the survival of the host, and here the symbiotic relationship is considered mutualistic. The origin of this mutualistic endosymbiosis is of interest for both basic and applied reasons: How does a parasite become a mutualist? Could intervention in the mutualism aid in treatment of human disease? Correct rooting and high-quality resolution of Wolbachia relationships are required to resolve this question. However, because of the large genetic distance between Wolbachia and the nearest outgroups, and the limited number of genomes so far available for large-scale analyses, current phylogenies do not provide robust answers. We therefore sequenced the genome of the D supergroup Wolbachia endosymbiont of Litomosoides sigmodontis, revisited the selection of loci for phylogenomic analyses, and performed a phylogenomic analysis including available complete genomes (from isolates in supergroups A, B, C, and D). Using 90 orthologous genes with reliable phylogenetic signals, we obtained a robust phylogenetic reconstruction, including a highly supported root to the Wolbachia phylogeny between a (A + B) clade and a (C + D) clade. Although we currently lack data from several Wolbachia supergroups, notably F, our analysis supports a model wherein the putatively mutualist endosymbiotic relationship between Wolbachia and nematodes originated from a single transition event

The frequency of thyroid gland invasion in advanced laryngeal malignancy: an audit of total laryngectomy histological specimens

This dissertation is submitted as a final copy as the University’s Academic and Clinical supervisorBackground Thyroid gland involvement in advanced laryngeal malignancies is a rare entity, mostly resulting from direct contiguous spread from anterior and inferior tumours. Reported practice is to perform a hemithyroidectomy at the time of laryngectomy. However, this results in pointless excision of functional tissue and the added morbidity of hypothyroidism post operatively. Aim The aim of this study is twofold: firstly, to assess the frequency of thyroid gland involvement in laryngectomy specimens from Chris Hani Baragwanath Hospital, and secondly, to determine any association between the anatomical subsites of tumour and thyroid gland involvement. Methods This is a retrospective clinical audit of histological reports on laryngectomy specimens collected over a 10 year period from January 2005 and December 2014. The study was conducted at Chris Hani Baragwanath Hospital, affiliated to the University of the Witwatersrand, in South Africa. ENT operating registries and the laboratory database were used to access all records of total laryngectomies done over the 10 year period. Seventy-three laryngectomies were done, 9 were excluded as no thyroid tissue was included in the sample and 1 was excluded due to inadequate demographic detail. Thus a total of 63 histological reports were included in the study. Data extracted included age, race, sex, pathological stage of tumour, thyroid gland involvement and anatomical subsites involved by tumour (subglottis, anterior commissure and transglottic tumours). Data was analysed using standard statistical methods including a Fischer-exact test and an ANOVA association test. Statistica software was used. Results Four of the 63 cases had thyroid gland involvement (6.35%). The majority of the patients were black males in the age group 50 to 60 years of age. The tumours were all advanced laryngeal malignancies and only 2 of the 63 cases were found to have a diagnosis of adenosquamous carcinoma and chondrosarcoma. None of the anatomical subsites were found to be statistically significant in association with thyroid gland involvement, however, this result was thought to be skewed due to the small number of tumours involving the thyroid gland. Conclusion In accordance with South African and international studies on the same topic, thyroid gland involvement in laryngeal tumours is a rare occurrence. Due to the complications of performing a thyroidectomy and the hypothyroidism that accompanies it, a thyroidectomy should not always be performed. However, due to the recurrence rates and poor prognosis of patients with stomal recurrence (associated with thyroid gland involvement), thyroidectomy still needs to be considered. Based on known anatomical pathways of extralaryngeal spread of tumours via the anterior commissure, paraglottic spaces and those tumours involving the subglottis, selected patients require thyroidectomy at the time of laryngectomy to achieve adequate oncological margins.MT201

Caspase-8 and c-FLIPL associate in lipid rafts with NF-kappaB adaptors during T cell activation.

Humans and mice lacking functional caspase-8 in T cells manifest a profound immunodeficiency syndrome due to defective T cell antigen receptor (TCR)-induced NF-kappaB signaling and proliferation. It is unknown how caspase-8 is activated following T cell stimulation, and what is the caspase-8 substrate(s) that is necessary to initiate T cell cycling. We observe that following TCR ligation, a small portion of total cellular caspase-8 and c-FLIP(L) rapidly migrate to lipid rafts where they associate in an active caspase complex. Activation of caspase-8 in lipid rafts is followed by rapid cleavage of c-FLIP(L) at a known caspase-8 cleavage site. The active caspase.c-FLIP complex forms in the absence of Fas (CD95/APO1) and associates with the NF-kappaB signaling molecules RIP1, TRAF2, and TRAF6, as well as upstream NF-kappaB regulators PKC theta, CARMA1, Bcl-10, and MALT1, which connect to the TCR. The lack of caspase-8 results in the absence of MALT1 and Bcl-10 in the active caspase complex. Consistent with this observation, inhibition of caspase activity attenuates NF-kappaB activation. The current findings define a link among TCR, caspases, and the NF-kappaB pathway that occurs in a sequestered lipid raft environment in T cells

Deletion of parasite immune modulatory sequences combined with immune activating signals enhances vaccine mediated protection against filarial nematodes

<p>Background: Filarial nematodes are tissue-dwelling parasites that can be killed by Th2-driven immune effectors, but that have evolved to withstand immune attack and establish chronic infections by suppressing host immunity. As a consequence, the efficacy of a vaccine against filariasis may depend on its capacity to counter parasite-driven immunomodulation.</p> <p>Methodology and Principal Findings: We immunised mice with DNA plasmids expressing functionally-inactivated forms of two immunomodulatory molecules expressed by the filarial parasite Litomosoides sigmodontis: the abundant larval transcript-1 (LsALT) and cysteine protease inhibitor-2 (LsCPI). The mutant proteins enhanced antibody and cytokine responses to live parasite challenge, and led to more leukocyte recruitment to the site of infection than their native forms. The immune response was further enhanced when the antigens were targeted to dendritic cells using a single chain Fv-αDEC205 antibody and co-administered with plasmids that enhance T helper 2 immunity (IL-4) and antigen-presenting cell recruitment (Flt3L, MIP-1α). Mice immunised simultaneously against the mutated forms of LsALT and LsCPI eliminated adult parasites faster and consistently reduced peripheral microfilaraemia. A multifactorial analysis of the immune response revealed that protection was strongly correlated with the production of parasite-specific IgG1 and with the numbers of leukocytes present at the site of infection.</p> <p>Conclusions: We have developed a successful strategy for DNA vaccination against a nematode infection that specifically targets parasite-driven immunosuppression while simultaneously enhancing Th2 immune responses and parasite antigen presentation by dendritic cells.</p&gt

Repeating the Errors of Our Parents? Family-of-Origin Spouse Violence and Observed Conflict Management in Engaged Couples

Based on a developmental social learning analysis, it was hypothesized that observing parental violence predisposes partners to difficulties in managing couple conflict. Seventy-one engaged couples were assessed on their observation of parental violence in their family of origin. All couples were videotaped discussing two areas of current relationship conflict, and their cognitions during the interactions were assessed using a video-mediated recall procedure. Couples in which the male partner reported observing parental violence (male-exposed couples) showed more negative affect and communication during conflict discussions than couples in which neither partner reported observing parental violence (unexposed couples). Couples in which only the female partner reported observing parental violence (female- exposed couples) did not differ from unexposed couples in their affect or behavior. Female-exposed couples reported more negative cognitions than unexposed couples, but male-exposed couples did not differ from unexposed couples in their reported cognitions

Academic self-concept, gender and single-sex schooling

This paper assesses gender differences in academic self-concept for a cohort of children born in 1958 (the National Child Development Study). We address the question of whether attending single-sex or co-educational schools affected students’ perceptions of their own academic abilities (academic self-concept). Academic selfconcept was found to be highly gendered, even controlling for prior test scores. Boys had higher self-concepts in maths and science, and girls in English. Single-sex schooling reduced the gender gap in self-concept, while selective schooling was linked to lower academic self-concept overall

Work-family life courses and BMI trajectories in three British birth cohorts.

BACKGROUND/OBJECTIVES: Combining work and family responsibilities has previously been associated with improved health in mid-life, yet little is known about how these associations change over time (both biographical and historical) and whether this extends to body mass index (BMI) trajectories for British men and women. The purpose of this study was to investigate relationships between work-family life courses and BMI trajectories across adulthood (16-42 years) for men and women in three British birth cohorts. SUBJECTS/METHODS: Multiply imputed data from three nationally representative British birth cohorts were used-the MRC National Survey of Health and Development (NSHD; 1946 birth cohort, n=3012), the National Child Development Study (NCDS; 1958 birth cohort, n=9614) and the British Cohort Study (BCS; 1970 birth cohort, n=8140). A typology of work-family life course types was developed using multi-channel sequence analysis, linking annual information on work, partnerships and parenthood from 16 to 42 years. Work-family life courses were related to BMI trajectories using multi-level growth models. Analyses adjusted for indicators of prior health, birthweight, child BMI, educational attainment and socioeconomic position across the life course, and were stratified by gender and cohort. RESULTS: Work-family life courses characterised by earlier transitions to parenthood and weaker long-term links to employment were associated with greater increases in BMI across adulthood. Some of these differences, particularly for work-family groups, which are becoming increasingly non-normative, became more pronounced across cohorts (for example, increases in BMI between 16 and 42 years in long-term homemaking women: NSHD: 4.35 kg m-2, 95% confidence interval (CI): 3.44, 5.26; NCDS: 5.53 kg m-2, 95% CI: 5.18, 5.88; BCS: 6.69 kg m-2, 95% CI: 6.36, 7.02). CONCLUSIONS: Becoming a parent earlier and weaker long-term ties to employment are associated with greater increases in BMI across adulthood in British men and women.Rebecca Lacey, Anne McMunn, Amanda Sacker and Meena Kumari received funding from the European Research Council (grant number: ERC-2011-StG_20101124, PI: Anne McMunn). Steven Bell also received funding from the European Research Council (grant number: ERCStG-2012-309337_Alcohol-Lifecourse, PI: Annie Britton) and UK Medical Research Council/Alcohol Research UK (MR/M006638/1). Amanda Sacker, Anne McMunn and Meena Kumari additionally received support from the Economic and Social Research Council’s International Centre for Life Course Studies in Society and Health (grant number: ES/J019119/1). DK is supported by the UK Medical Research Council (MC_UU_12019/1). The MRC National Survey of Health and Development is funded by the UK Medical Research Council. Peggy McDonough and Diana Worts were supported by the Canadian Institutes of Health Research grant MOP 119526 and the Social Sciences and Humanities Research Council grant 43512-1267

Estimating Lime Requirement for Oregon Soils with Non-Hazardous Soil Test Methods

Various soil tests are routinely used in the United States to predict soil lime requirement. New non-hazardous methods have recently been proposed for adoption in Oregon, however the accuracy of these methods for Oregon soils has not been established. The objectives of this investigation were: (a) to document and describe the development of lime requirement estimate (LRE) soil tests from 1900 to 2020, (b) to evaluate the accuracy of five non-hazardous LRE methods for Oregon soils, and (c) to evaluate how laboratory modifications to the Sikora LRE method affect the accuracy of lime rate recommendations. Four historical periods pertaining to the development of LRE methods were identified. From the 1900s to the 1930s, many wet-chemistry methods were proposed but were not adopted by commercial labs due to lack of method accuracy and to the amount of labor required. From the 1930s to the 1970s, the availability of the pH-sensitive glass electrode led to the development of fast and accurate buffer pH methods that are the foundation for methods that are still used today. From the 2000s to 2020, researchers proposed non-hazardous adaptations of buffer methods as well as the use of other soil test properties. Current research is focused on developing regional calibrations of non-hazardous methods. Twenty-four Oregon soils were incubated with lime (0 – 22.4 Mg ha-1) to determine their incubation lime requirement. Candidate LRE methods were correlated to incubation lime requirement to evaluate their accuracy. The Sikora (r2 = .90 – .92), Modified Mehlich (r2 = .87 – .89), and Sikora-2 (r2 = .81 – .93) buffer methods showed potential as non-hazardous alternatives to SMP (r2 = .90 – .92) based on accuracy and precision. Combining clay concentration, KCl-extractable Al, soil organic matter (SOM), extractable Mg, and pH1:2 also effectively predicted LRE with r2 = .96 – .97. The Moore-Sikora buffer method (r2 = .89 – .93) was similarly accurate but showed precision issues due to high replication variability. The Single Addition of Ca(OH)2 method (r2 = .69 – .77) was not considered to be an accurate predictor of lime requirement for Oregon soils. Five modifications to the Sikora buffer pH method were evaluated for five Oregon soils. Modifications related to mixing method, measurement in supernatant instead of slurry, and soil:water:buffer ratio were found to significantly increase the Sikora buffer pH value by 0.063, 0.065, and 0.058 units respectively in comparison to the control. Mean Sikora buffer pH decreased by 0.02 – 0.05 units when equilibration time was increased from 0 to 180 min. The results of these investigations demonstrate the feasibility of adopting at least one non-hazardous method for predicting lime requirement of Oregon soils. They also demonstrate the importance of accounting for method modifications and inter-laboratory variation for the Sikora LRE method. These results are anticipated to be used to help make accurate lime rate recommendations in Oregon

Integrated transcriptomic and proteomic analysis of the global response of Wolbachia to doxycycline-induced stress

The bacterium Wolbachia (order Rickettsiales), representing perhaps the most abundant vertically transmitted microbe worldwide, infects arthropods and filarial nematodes. In arthropods, Wolbachia can induce reproductive alterations and interfere with the transmission of several arthropod-borne pathogens. In addition, Wolbachia is an obligate mutualist of the filarial parasites that cause lymphatic filariasis and onchocerciasis in the tropics. Targeting Wolbachia with tetracycline antibiotics leads to sterilisation and ultimately death of adult filariae. However, several weeks of treatment are required, restricting the implementation of this control strategy. To date, the response of Wolbachia to stress has not been investigated, and almost nothing is known about global regulation of gene expression in this organism. We exposed an arthropod Wolbachia strain to doxycycline in vitro, and analysed differential expression by directional RNA-seq and label-free, quantitative proteomics. We found that Wolbachia responded not only by modulating expression of the translation machinery, but also by upregulating nucleotide synthesis and energy metabolism, while downregulating outer membrane proteins. Moreover, Wolbachia increased the expression of a key component of the twin-arginine translocase (tatA) and a phosphate ABC transporter ATPase (PstB); the latter is associated with decreased susceptibility to antimicrobials in free-living bacteria. Finally, the downregulation of 6S RNA during translational inhibition suggests that this small RNA is involved in growth rate control. Despite its highly reduced genome, Wolbachia shows a surprising ability to regulate gene expression during exposure to a potent stressor. Our findings have general relevance for the chemotherapy of obligate intracellular bacteria and the mechanistic basis of persistence in the Rickettsiales