The Human T-Cell Leukemia Virus Type I (HTLV-I) X Region Encoded Protein p13II Interacts with Cellular Proteins

AbstractInteractions between the Human T-cell leukemia virus type I (HTLV-I) gene product p13II and cellular proteins were investigated using the yeast two-hybrid system. Variant forms of p13II were derived from two HTLV-I molecular clones, K30p and K34p, that differ in both virus production and in vivo and in vitro infectivity. Two nucleotide differences between the p13 from K30p (p13K30) and K34p (p13K34) result in a Trp-Arg substitution at amino acid 17 and the truncation of the 25 carboxyl-terminal residues of p13K34. A cDNA library from an HTLV-I-infected rabbit T-cell line was screened with p13K30 and p13K34 as bait. Products of two cDNA clones, C44 and C254, interacted with p13K34 but not with p13K30. Interactions were further confirmed using the GST-fusion protein coprecipitation assay. Sequence analysis of C44 and C254 cDNA clones revealed similarities to members of the nucleoside monophosphate kinase superfamily and actin-binding protein 280, respectively. Further analysis of the function of these two proteins and the consequence of their interaction with p13 may help elucidate a role for p13 in virus production, infectivity, or the pathogenesis of HTLV-I

Visualizing the dynamics of HIV-specific cytotoxic T-cells in extracellular matrix

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biological Engineering, 2012.CD-ROM contains copy of thesis in .pdf format and files in .mov format.Cataloged from PDF version of thesis.Includes bibliographical references (p. 76-84).Cytotoxic lymphocytes (CTLs) traffic through tissues in search of antigen and mount protective immune responses against viral infections and cancer. While molecular mechanisms of CTL antiviral effector functions have been established in vitro, they have been defined in the absence of physiological dynamics and migration. Furthermore, longterm dynamics of single cells have been inaccessible in vivo, where brief imaging durations have been achieved (-30-60 min). Presently, several key aspects of CTL dynamics and function remain unknown: whether individual CTLs migrating within tissues kill multiple targets, if CTLs exhibit spatiotemporal coordination of effector functions, or if migrating CTLs effect these functions in different compartments. Thus, a mechanistic understanding of multidimensional CTL function might directly inform therapeutic strategies. In this thesis, we first developed an approach for long-term high-speed optical imaging of cellular dynamics for continuous periods of 24 hours. HIV-specific CTLs were visualized as they encountered CD4+ target cells within a three-dimensional extracellular matrix tissue model supporting migration of both CTLs and targets. Using this approach, we found that high-avidity CTLs engaged, arrested, and killed the first target encountered with near-perfect efficiency. These CTLs remained in contact with dead targets for hours, accumulating TCR signals and upregulating antiviral cytokine and chemokine secretion for >12 hours, but were refractory to killing additional targets. By contrast, lower-avidity CTLs exhibited poor efficiency and target migration directly impeded CTL killing. Thus, high-avidity CTLs coordinate multiple antiviral functions in four dimensions (3D space and time): effectively destroying the first detected infected cell during an initial "commitment phase", but rapidly transitioning to a prolonged "secretory phase." In vivo, coordination of lytic and non-lytic effector functions will direct the local inflammatory milieu and recruit additional effectors to the tissue. We conclude that the efficiency of antigen recognition by individual migrating CTLs is a critical, but previously undefined, parameter of CTL function. Furthermore, TCR avidity and initial CTL efficiency are prerequisites for sustained antiviral polyfunctionality; together these parameters define a highly effective, multidimensional CTL response, which may inform the design of increasingly effective vaccines.by Maria Hottelet Foley.Ph.D

HIV-2 infection in a migrant from Gambia: the history of the disease combined with phylogenetic analysis revealed the real source of infection

Human immunodeficiency virus type 2 (HIV-2) infection prevalence is increasing in some European countries. The increasing migratory flow from countries where HIV-2 is endemic has facilitated the spread of the virus into Europe and other regions. We describe a case of HIV-2 infection in a migrant individual in the Asylum Seeker Centre (ASC) in Italy. The patient's virus was sequenced, and found to be a typical HIV-2 genotype A virus. Bayesian evolutionary analysis revealed that the HIV-2 sequence from migrant dated back to 1986 in a subcluster including sequences from Guinea Bissau. This was coherent with the migrant history who lived in Guinea Bissau from his birth until 1998 when he was 13 years old. Monitoring for HIV-2 infection in migrants from western Africa is necessary using adequate molecular tools to improve the diagnosis and understand the real origin of infection

Progression and adherence to an individually prescribed and supervised resistance training intervention in older adults recovering in hospital from lower limb fragility fracture

This study evaluated adherence and progression with a 12-week resistance training program amongst a sample of older adults recovering in hospital from lower limb fragility fracture. Forty-nine participants (mean age 84 years) commenced the resistance training program seven days after the injury. The exercise prescription involved training of the hip and knee extensors, hip abductors, and ankle plantar- and dorsi flexors using resistive bands. Exercise sessions were completed tri-weekly for six weeks under supervision by a physiotherapist and tri-weekly for an additional six weeks independently. Adherence was assessed as the proportion of exercise sessions completed of those prescribed and any progression in resistance was documented. Level of adherence was not found to be influenced by age, gender, cognition or strength but was greater amongst those admitted from the community setting and for the first six weeks when supervision was present. Participants were able to obtain similar levels of resistance for the injured side compared to the noninjured side for all exercises excluding hip abduction and those admitted from the community setting achieved higher levels of resistance compared to those admitted from the residential care setting. These findings suggest that an early resistance training program is feasible and well tolerated amongst older adults recovering from lower limb fragility fracture. Further work is necessary to determine how this level of resistance training translates into functional improvements and how to improve adherence levels in clinical rehabilitation settings

Time allocation to balance group living trade-offs in Ethiopian wolves

Living in groups requires individuals to make trade-offs to maintain group cohesion and enhance individual and inclusive fitness. One way animals can do this is by adjusting the way they allocate time to different behaviours. Ethiopian wolves (Canis simensis) are highly social, cooperative breeders (only the dominant pair breeds and all members help to raise the litter), but solitary foragers. To investigate how Ethiopian wolves allocate their time to balance the costs and benefits of group living, we analysed the time budgets of 47 wolves across six behaviours. We hypothesized that group size and territory density would affect wolves’ time allocation between solitary (foraging) and communal activities (patrolling and socialising) differently in relation to their age, dominance status or sex, and whether the pack was breeding or not. Our results showed that the time spent foraging alone increased at higher territorial densities, as expected from interference competition, particularly among subadults, subordinates and individuals in breeding packs. On the other hand, as pack size increased, adult wolves spent a lower proportion of time patrolling, while the time spent socialising did not change. Living in groups reduces the costs of communal activities, but crowded territories come at the cost of interference competition for solitary foragers, particularly the animals further down the hierarchy ranks, subadults, and individuals investing in breeding. Such trade-offs could impose an upper limit to group size and population growth within a limited space. Furthermore, anthropogenic disturbance could alter the balance of social and solitary activities of Ethiopian wolves

Patient experience of different regional models of urgent and emergency care: a cross-sectional survey study

Objectives: To compare user experiences of 8 regional urgent and emergency care systems in the Republic of Ireland, and explore potential avenues for improvement. Design: A cross-sectional survey. Setting: Several distinct models of urgent and emergency care operate in Ireland, as system reconfiguration has been implemented in some regions but not others. The Urgent Care System Questionnaire was used to explore service users' experiences with urgent and emergency care. Linear regression and logistic regression were used to detect regional variation in each of the 3 domains and overall ratings of care. Participants: A nationally representative sample (N=8002) of the general population was contacted by telephone, yielding 1205 participants who self-identified as having used urgent and emergency care services in the previous 3?months. Main outcome measures Patient experience was assessed across 3 domains: entry into the system, progress through the system and patient convenience of the system. Participants were also asked to provide an overall rating of the care they received. Results: Service users in Dublin North East gave lower ratings on the entry into the system scale than those in Dublin South (adjusted mean difference=?0.18; 95% CI ?0.35 to ?0.10; p=0.038). For overall ratings of care, service users in the Mid-West were less likely than those in Dublin North East to give an excellent rating (adjusted OR 0.57; 95% CI 0.35 to 0.92; p=0.022). Survey items relating to communication, and consideration of patients' needs were comparatively poorly rated. The use of public emergency departments and out-of-hours general practice care was associated with poorer patient experiences. Conclusions: No consistent relationship was found between the type of urgent and emergency care model in different regions and patient experience. Scale-level data may not offer a useful metric for exploring the impact of system-level service change

Expressional alterations in functional ultra-conserved non-coding rnas in response to all-trans retinoic acid - induced differentiation in neuroblastoma cells.

BACKGROUND: Ultra-conserved regions (UCRs) are segments of the genome (≥ 200 bp) that exhibit 100% DNA sequence conservation between human, mouse and rat. Transcribed UCRs (T-UCRs) have been shown to be differentially expressed in cancers versus normal tissue, indicating a possible role in carcinogenesis. All-trans-retinoic acid (ATRA) causes some neuroblastoma (NB) cell lines to undergo differentiation and leads to a significant decrease in the oncogenic transcription factor MYCN. Here, we examine the impact of ATRA treatment on T-UCR expression and investigate the biological significance of these changes. METHODS: We designed a custom tiling microarray to profile the expression of 481 T-UCRs in sense and anti-sense orientation (962 potential transcripts) in untreated and ATRA-treated neuroblastoma cell lines (SH-SY5Y, SK-N-BE, LAN-5). Following identification of significantly differentially expressed T-UCRs, we carried out siRNA knockdown and gene expression microarray analysis to investigate putative functional roles for selected T-UCRs. RESULTS: Following ATRA-induced differentiation, 32 T-UCRs were differentially expressed (16 up-regulated, 16 down-regulated) across all three cell lines. Further insight into the possible role of T-UC.300A, an independent transcript whose expression is down-regulated following ATRA was achieved by siRNA knockdown, resulting in the decreased viability and invasiveness of ATRA-responsive cell lines. Gene expression microarray analysis following knockdown of T-UC.300A revealed a number of genes whose expression was altered by changing T-UC.300A levels and that might play a role in the increased proliferation and invasion of NB cells prior to ATRA-treatment. CONCLUSIONS: Our results indicate that significant numbers of T-UCRs have altered expression levels in response to ATRA. While the precise roles that T-UCRs might play in cancer or in normal development are largely unknown and an important area for future study, our findings strongly indicate that the function of non-coding RNA T-UC.300A is connected with proliferation, invasion and the inhibition of differentiation of neuroblastoma cell lines prior to ATRA treatment

Fossilized skin reveals coevolution with feathers and metabolism in feathered dinosaurs and early birds

Feathers are remarkable evolutionary innovations that are associated with complex adaptations of the skin in modern birds. Fossilised feathers in non-avian dinosaurs and basal birds provide insights into feather evolution, but how associated integumentary adaptations evolved is unclear. Here we report the discovery of fossil skin, preserved with remarkable nanoscale fidelity, in three non-avian maniraptoran dinosaurs and a basal bird from the Cretaceous Jehol biota (China). The skin comprises patches of desquamating epidermal corneocytes that preserve a cytoskeletal array of helically coiled α-keratin tonofibrils. This structure confirms that basal birds and non-avian dinosaurs shed small epidermal flakes as in modern mammals and birds, but structural differences imply that these Cretaceous taxa had lower body heat production than modern birds. Feathered epidermis acquired many, but not all, anatomically modern attributes close to the base of the Maniraptora by the Middle Jurassic

Case report: meningitis as a presenting feature of anti-NMDA receptor encephalitis

BACKGROUND:Meningitis is a very rare atypical presenting feature of anti-NMDA receptor encephalitis. In our case report, we describe an unusual clinical presentation of anti-NMDA receptor encephalitis with a biphasic pattern of meningitis followed by encephalitis and discuss potential mechanisms underlying this presentation. We aim to widen the differential diagnosis to be considered in a patient presenting with clinical meningitis and pyrexia. CASE PRESENTATION:This is a case of a 33-year old Caucasian woman who initially presented with a lymphocytic meningitis attributed to a viral infection. She subsequently developed fluctuating consciousness, agitation, visual hallucinations, dyskinetic movements, a generalized tonic-clonic seizure, and autonomic instability. Investigations revealed a diagnosis of anti-NMDA receptor encephalitis secondary to a previously unidentified ovarian teratoma. She made an excellent recovery with immunotherapy and removal of the teratoma. CONCLUSION:Clinicians should consider autoimmune encephalitides in individuals with meningitis, particularly where extensive investigations fail to identify a causative pathogen and there is rapid development of an encephalitic phenotype

Carbon and Nitrogen Isotopic Signatures of Hair, Nail, and Breath from tropical African Human Populations

RATIONALE: Stable isotopic analyses are increasingly used to study the diets of past and present human populations. Yet, the carbon and nitrogen isotopic data of modern human diets collected so far are biased towards Europe and North America. Here, we address this gap by reporting on the dietary isotopic signatures of six tropical African communities: El Molo, Turkana (Kerio), Luhya (Webuye), Luhya (Port Victoria), and Luo (Port Victoria) from Kenya, and Baka from Cameroon; representing four subsistence strategies: fishing, pastoralism, agriculturalism, and hunter-gatherer. METHODS: We used EA-CF-IRMS to measure the carbon and nitrogen isotopic ratios of hair (n = 134) and nail (n = 80), and the carbon isotopic ratios of breath (n = 184) from these communities, as well as the carbon and nitrogen isotopic ratios of some food samples from the Kenyan communities. RESULTS: We expand on the known range of δ13 C values in human hair through the hunter-gatherer Baka, with a diet based on C3 plants, and through the agriculturalist Luhya (Webuye), with a diet based on C4 plants. In addition, we found that the consumption of fish from East African lakes is difficult to detect isotopically due to the combined effects of high nitrogen isotopic ratios of plants and the low nitrogen isotopic ratios of fish. Finally, we found that some of the communities studied are markedly changing their diets through increasing sedentism and urbanization. CONCLUSION: Our findings contribute substantially to the understanding of the environmental, demographic and economic dynamics that affect the dietary landscape of different tropical populations of Africa. These results highlight the importance of studying a broader sample of human populations and their diet, with a focus on their precise context - both from an isotopic and more general anthropological perspectives.This study was funded by a European Research Council Advanced Award to MML (In-Africa Project, ERC 295907), and carried out with permission from the National Commission for Science, Technology and Innovation, Kenya, No. NACOSTI/P/15/2669/4758