Focusing in on structural genomics : the University of Queensland structural biology pipeline

The flood of new genomic sequence information together with technological innovations in protein structure determination have led to worldwide structural genomics (SG) initiatives. The goals of SG initiatives are to accelerate the process of protein structure determination, to fill in protein fold space and to provide information about the function of uncharacterized proteins. In the long-term, these outcomes are likely to impact on medical biotechnology and drug discovery, leading to a better understanding of disease as well as the development of new therapeutics. Here we describe the high throughput pipeline established at the University of Queensland in Australia. In this focused pipeline, the targets for structure determination are proteins that are expressed in mouse macrophage cells and that are inferred to have a role in innate immunity. The aim is to characterize the molecular structure and the biochemical and cellular function of these targets by using a parallel processing pipeline. The pipeline is designed to work with tens to hundreds of target gene products and comprises target selection, cloning, expression, purification, crystallization and structure determination. The structures from this pipeline will provide insights into the function of previously uncharacterized macrophage proteins and could lead to the validation of new drug targets for chronic obstructive pulmonary disease and arthritis.

Apparent in vivo Δ-6 desaturase activity, efficiency, and affinity are affected by total dietary C18 PUFA in the freshwater fish Murray cod

Dietary fatty acids are known to modulate fatty acid metabolism in fish. However, the innate capability of fish to bioconvert short chain fatty acids to health promoting long chain fatty acids (LCPUFA) is insufficient to compensate for a reduced dietary intake. While many studies have focused on the dietary regulation of the fatty acid bioconversion pathways, there is little known regarding the effects of the dietary levels of C18 polyunsaturated fatty acids (PUFA) on fatty acid metabolism. Here, we show a greater degree of apparent enzyme activity (Δ-6 desaturase) in fish fed a diet with higher amounts of dietary C18 PUFA. In particular, fish receiving high amounts of dietary C18 PUFA had a greater amount of Δ-6 desaturase activity acting on 18:3n-3 than 18:2n-6. However, with the gradual reduction of dietary C18 PUFA there was a shift in substrate preference of Δ-6 desaturase from 18:3n-3 to 18:2n-6. This information will provide valuable insight for the implementation of low fish oil diets, which permit the maintenance of n-3 LCPUFA levels in farmed Murray cod.

Bovine Muc1 is a highly polymorphic gene encoding an extensively glycosylated mucin that binds bacteria

The bovine Muc1 protein is synthesized by mammary epithelial cells and shed into milk as an integral component of the milk fat globule membrane; however, the structure and functions of this mucin, particularly in relation to lactation, are poorly defined. The objectives of this investigation were to investigate the Muc1 gene and protein structures in the context of lactation and to test the hypothesis that Muc1 has a role in innate immune defense. Polymerase chain reaction analysis of genomic DNA from 630 cattle revealed extensive polymorphism in the variable number of tandem repeats (VNTR) in the bovine Muc1 gene. Nine allelic
variants spanning 7 to 23 VNTR units, each encoding 20 AA, were identified. Three alleles, containing 11, 14, and 16 VNTR units, respectively, were predominant. In addition, a polymorphism in one of the VNTR units has the potential to introduce a unique site for N-linked glycosylation. Statistical analysis indicated weak associations between the VNTR alleles and milk protein and fat percentages in a progeny-tested population of Holstein-Friesian dairy cattle. No association with somatic cell count could be demonstrated. Bovine Muc1 was purified from milk fat globule membranes and characterized. The protein was highly glycosylated, primarily with O-linked sialylated T-antigen [Neu5Ac(α2–3)-Gal(β1–3)-GalNAcα1] and, to a lesser extent, with N-linked oligosaccharides, which together accounted for approximately 60% of the apparent mass of Muc1. Purified bovine Muc1 directly bound fluorescently labeled Escherichia coli BioParticles (Invitrogen, Mount Waverley, Australia) and inhibited their binding to bovine mammary epithelial cells grown in vitro.

Changing bodies, changing discourses : women's experiences of early menopause

Early menopause has been constructed by discourses of biological determinism as an untimely, but natural, failure of the female body. Medical discourses in particular have interpreted early menopause as a congenital irregularity and a rare anomaly of menopause at midlife. In this thesis I challenge the notion that early menopause is an innate imperfection related only to women’s age. I propose that early menopause is dependent upon the cultural interpretations of individual women and is constituted through the mercurial and multiple discourses of women who have this embodied experience. Moreover, I reveal that early menopause is a contemporary condition and that its location in history is inextricably bound to discourses of risk, naturalism and the self. Further I make the assumption that having an early menopause both affects and is an effect of women’s fertility, sexuality and subjectivity. I have drawn upon a broad range of sources to provide a sociological analysis of early menopause. Literature on early menopause is dominated by positivist discourses, yet many alternate discourses negotiate these influential constructions. I suggest here that the perception of early menopause as a natural fault is merely a construction by medical discourses and does not incorporate the dynamic discourses of early-menopausal women. Moreover, the restriction of early menopause to a genetic female failure excludes the majority of women who have an early menopause through iatrogenisis. This omission occurs through the failure of positivist discourses to accommodate diversity in discourses. Recent sociological and feminist studies have vindicated menopausal women. They have reconstructed menopause through notions of embodiment and have removed the veil of negativity used by the medical sciences to contain menopausal women (Komesaroff, Rothfield and Daly 1997). The visibility of menopausal women, however, remains connected to age. Menopause has been created as a predictable consequence of aging and as such has come to be synonymous with middle age. Nowadays, even men are said to experience menopause at midlife (Carruthers 1996). But early menopause is constituted within the discourses of women who have this experience. Medico-scientific discourses, based upon theories of genetic inevitability, disregard this perspective. Consequently early menopause is subsumed by naturalistic discourses that relate menopause to midlife. Such restraint reflects the unease created by menopause that does not coincide with prescribed life stages. Women's experiences of their changing bodies are largely unheard. Thus, women who have an early menopause are faced with a chasm of ‘cultural non-recognition’ (Fraser 1997). Conjointly with this discursive repression early-menopausal women face social imbalances that are transacted as both cause and consequence of early menopause. In particular the contemporary creation of early menopause is bound to the social and historical location of women as a group. Women are exploited by the institution of medicine, ‘exposure to environmental toxicity’ (Fraser 1997: 11) and commercialization as causes of early menopause. Yet the corporeal effects of practices of risk avoidance (Beck 1993), social practices (Shilling 1993) and Western consumerism (Lupton 1994) fail to be recognized. I address these problematics through a poststructural and feminist critique that assumes moments of commonality among women, while at the same time recognizes shifting and multiple differences (Nicholson 1999). I suggest here that early menopause falls into cultural misrecognition in Fraser's (1997) terms and argue that it is united concurrently with the gender injustice of androcentrism (Fraser 1997: 21). Fraser (1997: 16) suggests that it is only by relating these dual problematics that we are able to make sense of current dilemmas. Thus I have critiqued early menopause through a connection between individual embodied experiences of early menopause and early menopause as a modern phenomenon that is specific to women. I have attempted to unravel these arguments that simultaneously call to ‘... abolish gender differentiation and to valorize gender specificity’ (Fraser 1997: 21) while at the same time acknowledging their interconnectedness. An approach of merely combining women’s discourses with overarching social issues would be inadequate as not only do these problematics intersect but they also can be opposed. As Fraser (1997: 25) notes with her theory, redressing one aspect of cultural or social analysis can further imbalance another. For instance making visible the diversity and uniqueness of individual experiences of early menopause could detract from acknowledging the contemporary construction of early menopause through social inequality. Crucial to this understanding is a destabilizing of the binary construction of differences between the sexes that makes way for a reconstruction of early menopause through ‘sexual slippage’ (Matus 1995). In this thesis I look for a subtlety between the particular and the collective that views early menopause as concurrently a singular and changeable experience as well as imbedded in social practice. I suggest that these concepts are entwined as interactive effects of early menopause. Thus I have analyzed the bivalent problematics of the embodiment and social location of early menopause as imbricated, dynamic and unending discourses. From this perspective I reviewed the literature that was available on early menopause. In Chapter One I look to descriptions of early menopause and note that it has disappeared into a conglomeration of disparate, mostly medical, discourses that are contradictory. Nevertheless medical discourses offer ‘conclusive’ definitions of early menopause that are based on naturalistic views of the body (Shilling 1994). The determinants used are inconsistent and do not include women's discourses of early menopause. Thus, dominant medical discourses obscure women’s embodied experiences of early menopause and ignore the contemporary causes of early menopause. In Chapter Two I examine the causes of early menopause as a way of explaining the disparity between medical discourses and my anecdotal observations of early menopause as a fairly common contemporary occurrence. The relatively recent escalation in gynaecological surgery, especially hysterectomy, appears to account almost single-handedly for early menopause as a current phenomenon. Moreover, the extraordinary number of women who have their uterus removed at hysterectomy can be interpreted as a modern implementation of ancient anxieties. Women's sexuality has been constructed throughout history as problematic and this unease has been translated through women's bodies as dangerous and in need of control (Greer 1992). Thus social concerns which have evolved historically have emerged through the representation of a woman's uterus as an unseen, dark and mysterious risk (Beck 1993). Medical discourses define this risk and are able to negate the so-called dangers of women's sexuality through the surgical removal of their organs. Widespread negotiation of medical discourses is apparent, as hysterectomy in the modern Western world is the most common of all surgical operations (Hufnagel 1989). It is overwhelmingly the most common cause of early menopause as well. I examine also the historical condemnation of infertile women and how this anxiety has been transposed to the modern world through the commercialization of reproduction. Transactions of this social unease can cause early menopause. For instance the medical technology of in-vitro fertilization (I.V.F.) has been offered as a panacea for the infertility of early menopause but, paradoxically, can cause early menopause as well. Conception through technology has been normalized as a viable option for women who are unable to conceive and understandings of I.V.F. have moved into everyday discourse. Medical discourses have constructed fertility as a saleable item and infertile women expect that they can purchase this merchandise. Human eggs have become lucrative commodities that now are available in the market place. Egg ‘donation’ for I.V.F. programs can hasten the attrition rate of eggs and can cause early menopause in some pre-menopausal women (Rowland 1992: 24). Even the recycling of a woman’s uterus supposedly has become a possibility through the transferring of this ‘used’ organ at hysterectomy to a recipient woman who can use the other woman’s uterus as a ‘gestational garage’ (Rogers 1998). In this way women have been disembodied as mechanical systems with inter-changeable body parts and the potentially detrimental consequences of these commercial transactions are ignored. In addition I show how early menopause can be caused by the connection between the self and the social structure. Women's subjectivity is constituted through the cultural discourses available to them and these discourses affect social behaviour (Lupton 1995). For instance smoking and dieting have been identified as causes of early menopause. These activities have been related to the creation of women’s bodies as hetero-sexually desirable and are endemic to young women (Evans-Young 1995). This suggests that cultural causes of early menopause are transactions of sexual politics. Yet there is a paucity of literature that acknowledges the relationship between women’s subjectivity and early menopause. Thus the second chapter exposes a link between sexual politics and causes of early menopause through women's relationships with risk, naturalism and the self. In Chapter Three I deconstruct early menopause through theoretical considerations. I rely on an overarching poststructuralism that embraces the concept of fragmented plural discourses and the subjectivity of menopausal women as a continuous process (Komesaroff 1997: 61). I have woven these variables through broad feminist critiques (Leonard 1997). Through this eclectic approach I hoped to find some loose alignment between the corporeal, ontological and embodied dimensions of early menopause. The recurring themes of sexuality, fertility and subjectivity emerge through deconstructing discourses of sexual difference as immutable and non-negotiable; exposing ‘premature ovarian failure’ as a discursive construction that censures early-menopausal women; and acknowledging the discourses of individual women as unique, diverse and dynamic. I looked to a method of exposing some of these individual discourses and in Chapter Four I describe a critical research process aimed at understanding early menopause as a lived experience. In the remaining chapters I align these ontological arguments with an analysis of the discourses of women who had experienced or were experiencing an early menopause. This section partly relieves the ‘cultural non-recognition’ of the discourses of early-menopausal women. I recorded the narratives of fifty early-menopausal women through in-depth interviews and used this empirical data to direct the study. This data provides the opportunity to understand early menopause as an assortment of embodied experiences. For instance women’s experiences of age at commencement of menopause spanned over three and half decades. They did not reflect the age specifications prescribed by medical discourses. Rather women interpreted their experiences within their own discourses and determined their menopause as early based upon the expectations of their cultural context. Many of the women experienced changes attributed to menopause at midlife. It was not these changes that were significant to early-menopausal women it was how each woman translated these changes that provided meanings of early menopause. In Chapter Five I introduce the women through a table that connects the varying experiences of each woman. This profile shows that, in the main, the women’s experiences of early menopause were unexpected. I suggest that this is due to the disparity between early-menopausal women’s experiences and the current age and social norms of menopause. By bracketing the women into cohorts patterns emerged displaying differences between women who had menopause in their teens, twenties, thirties and forties. Adolescent women had intense feelings of abnormality and despair. Women who were in their twenties were less devastated by menopause than the younger women but described their sexuality and self-identity as changing. And although some women in their thirties were shocked or dismayed to have an early menopause others were ambivalent or happy. These women also described their sexuality and self-identity through changing discourses. A number of the women who were in their forties said that they were ‘too young for the menopause’ but were far less despondent than the younger women. It seemed that the greater the distance between age norms and social norms the more negatively women responded. Age norms that determine the social norms of women's lives through a ‘biological clock’ are constructed to reflect social values. But age is a social construction that changes over time. Thus it would appear that women’s changing bodies and changing discourses of early menopause are in the process of recreating age and social norms around menopause. In Chapter Six I draw upon women’s narratives that describe a connection between early menopause and sexuality. Yet the respondents were not unified in their constructions of sexuality. For instance a number of the women rejected the containment of their sexuality as absolute and defined in terms of bi-lateral hetero-sexual opposition. The discourses of these women constructed their sexuality as continuously flexible. Some early-menopausal women described this sexual mobility as an equivocal relationship between their sexuality, reproductive capacity and female organs. Other women articulated their sexuality as vacillating, ambiguous and unrepresentative of the so-called ‘true woman’. Several felt that they were not meant to have female reproductive organs at all. Nearly one third of the women had had their uterus removed at hysterectomy and the reproductive organs of two women were rudimentary. Women’s narratives showed that the social value of fertility influences constructions of early menopause. In Chapter Seven I record the contrast between the poignant responses of women who wished to have a baby of their own and other women who resisted discourses that entwine reproductivity with being a woman. For instance some women negotiated fertility through economic discourses of consumerism with the expectation that they could purchase conception as a commodity. Other women welcomed their early menopause as freedom from contraceptive concerns and others had no interest in reproduction at all. Thus discord arose through discourses that problematize early-menopausal women as non-reproductive and discourses that value variability. In addition many of the women’s accounts constructed their subjectivity as mobile, challenging the notion that discourses of the self are immutable. Chapter Eight presents narratives which suggest that the subjectivity of many women was altered continuously by early menopause. Yet some of the women rejected the construction of their subjectivity as unfluctuating. These contradictions reflect the uncertainties of the contemporary world. Nevertheless most respondents found that the tethering of menopause to constructions of midlife was incongruous with their own experiences. Many women refused to accept the label of social redundancy attached to middle-aged women. They moved their subjectivity beyond the reproductive body to a shifting and tractable identity of the self. This thesis demonstrates that the medical construction of early menopause as a rare and natural female flaw varies from women's experiences which suggest that early menopause is common and discursively constructed. This disparity has occurred through the privilege placed upon the construction of bodies as immutable and sexually static. This privileging has obscured the multi-dimensional causes of early menopause and given preference to a mono-causal theory. By exposing the variety of causes of early menopause the medical construction of women through a universal and unalterable body of reproduction is challenged. Moreover, women's discourses of early menopause demonstrate that the medical reduction of early menopause to a spontaneous bio-chemical malfunction has ignored the volatility of women’s embodied experiences. Women experience early menopause variously and through mercurial discourses. I suggest here that women's discourses of their experiences of early menopause reflect recurring and restructuring philosophical quandaries of fertility, sexuality and subjectivity. While there can be no representative claims made from this thesis it contributes to an understanding of the embodied experiences of early menopause. It provides an understanding of the creation of early menopause through social practices and goes part way to redressing the problematics of what Fraser terms ‘cultural non-recognition’. But, more importantly, it acknowledges early menopause as a variety of experiences where women interpret their changing bodies through changing discourses.

Instructional strategies integrating cognitive style construct : a meta-knowledge processing model

The overarching goal of this dissertation was to evaluate the contextual components of instructional strategies for the acquisition of complex programming concepts. A meta-knowledge processing model is proposed, on the basis of the research findings, thereby facilitating the selection of media treatment for electronic courseware. When implemented, this model extends the work of Smith (1998), as a front-end methodology, for his glass-box interpreter called Bradman, for teaching novice programmers. Technology now provides the means to produce individualized instructional packages with relative ease. Multimedia and Web courseware development accentuate a highly graphical (or visual) approach to instructional formats. Typically, little consideration is given to the effectiveness of screen-based visual stimuli, and curiously, students are expected to be visually literate, despite the complexity of human-computer interaction. Visual literacy is much harder for some people to acquire than for others! (see Chapter Four: Conditions-of-the-Learner) An innovative research programme was devised to investigate the interactive effect of instructional strategies, enhanced with text-plus-textual metaphors or text-plus-graphical metaphors, and cognitive style, on the acquisition of a special category of abstract (process) programming concept. This type of concept was chosen to focus on the role of analogic knowledge involved in computer programming. The results are discussed within the context of the internal/external exchange process, drawing on Ritchey's (1980) concepts of within-item and between-item encoding elaborations. The methodology developed for the doctoral project integrates earlier research knowledge in a novel, interdisciplinary, conceptual framework, including: from instructional science in the USA, for the concept learning models; British cognitive psychology and human memory research, for defining the cognitive style construct; and Australian educational research, to provide the measurement tools for instructional outcomes. The experimental design consisted of a screening test to determine cognitive style, a pretest to determine prior domain knowledge in abstract programming knowledge elements, the instruction period, and a post-test to measure improved performance. This research design provides a three-level discovery process to articulate: 1) the fusion of strategic knowledge required by the novice learner for dealing with contexts within instructional strategies 2) acquisition of knowledge using measurable instructional outcome and learner characteristics 3) knowledge of the innate environmental factors which influence the instructional outcomes This research has successfully identified the interactive effect of instructional strategy, within an individual's cognitive style construct, in their acquisition of complex programming concepts. However, the significance of the three-level discovery process lies in the scope of the methodology to inform the design of a meta-knowledge processing model for instructional science. Firstly, the British cognitive style testing procedure, is a low cost, user friendly, computer application that effectively measures an individual's position on the two cognitive style continua (Riding & Cheema,1991). Secondly, the QUEST Interactive Test Analysis System (Izard,1995), allows for a probabilistic determination of an individual's knowledge level, relative to other participants, and relative to test-item difficulties. Test-items can be related to skill levels, and consequently, can be used by instructional scientists to measure knowledge acquisition. Finally, an Effect Size Analysis (Cohen,1977) allows for a direct comparison between treatment groups, giving a statistical measurement of how large an effect the independent variables have on the dependent outcomes. Combined with QUEST's hierarchical positioning of participants, this tool can assist in identifying preferred learning conditions for the evaluation of treatment groups. By combining these three assessment analysis tools into instructional research, a computerized learning shell, customised for individuals' cognitive constructs can be created (McKay & Garner,1999). While this approach has widespread application, individual researchers/trainers would nonetheless, need to validate with an extensive pilot study programme (McKay,1999a; McKay,1999b), the interactive effects within their specific learning domain. Furthermore, the instructional material does not need to be limited to a textual/graphical comparison, but could be applied to any two or more instructional treatments of any kind. For instance: a structured versus exploratory strategy. The possibilities and combinations are believed to be endless, provided the focus is maintained on linking of the front-end identification of cognitive style with an improved performance outcome. My in-depth analysis provides a better understanding of the interactive effects of the cognitive style construct and instructional format on the acquisition of abstract concepts, involving spatial relations and logical reasoning. In providing the basis for a meta-knowledge processing model, this research is expected to be of interest to educators, cognitive psychologists, communications engineers and computer scientists specialising in computer-human interactions.

Consistent male–male paternity differences across female genotypes

In a recent paper, we demonstrated that male-female genetic relatedness determines male probability of paternity in experimental sperm competition in the Peron's tree frog (Litoria peronii), with a more closely related male out-competing his rival. Here, we test the hypothesis that a male-male difference in siring success with one female significantly predicts the corresponding difference in siring success with another female. With male sperm concentration held constant, and the proportion of viable sperm controlled statistically, the male-male difference in siring success with one female strongly predicted the corresponding difference in siring success with another female, and alone explained more than 62 per cent of the variance in male-male siring differences. This study demonstrates that male siring success is primarily dictated by among-male differences in innate siring success with less influence of male-female relatedness.

Optimal redistribution when educational background matters

Higher education plays an important role in determining individuals lifetime
earnings. In turn, the decision to become educated depends to a large extent on innate ability and on family characteristics, including both family
wealth and educational background. In this paper, we abstract from family
income differences to concentrate on the effects of fiscal policies on the
decision to undertake higher education when the educational background
matters. In a dynamic framework, where successive generations are linked by educational background, we consider a government that uses both linear income taxation and a lump-sum subsidy to education. Conditions for
optimality of each policy are derived. The factors that determine the sign
and magnitude of the tax rate and the subsidy are identified and include
concerns for redistribution, efficiency and the educational externality on
future generations

Psychological study of consumer novelty seeking and mass media consumption

The thesis integrates theory from psychology and marketing, finding that those with an innate desire to seek out information on new products / brands are motivated to do so by aspects of regulatory focus, needs for uniqueness, and their susceptibility to interpersonal influence. In turn, these people consume more media and have higher information exposure.

Lactoferrin and cancer in different cancer models

Lactoferrin (Lf) is a multifunctional protein and an essential element of innate immunity. Cancer is a major killer in today's world accounting for around 13% of all deaths according to the World Health Organisation (W.H.O.). The five most common forms of cancer include lung, colorectal, stomach, liver and breast cancer. Lactoferrin is a natural forming iron-binding glycoprotein with antibacterial, antioxidant and anti-carcinogenic effects. It is produced in exocrine glands and is secreted in many external fluids as a first line of defence. Lactoferrin also has the capacity to induce apoptosis and inhibit proliferation in cancer cells as well as restore white and red blood cell levels after chemotherapy. This review focuses on the therapeutic effect bovine sourced lactoferrin has on various forms of cancer in various models. It also focuses on the benefits of 3D in vitro cell culture. 3D cell culture has vast advantages over 2D models including demonstration of realistic therapeutic results and heightened resistance that 2D models fail to display.

Female choice for males with greater fertilization success in the Swedish Moor Frog, Rana arvalis

Background: Studies of mate choice in anuran amphibians have shown female preference for a wide range of male traits despite females gaining no direct resources from males (i.e. non-resource based mating system). Nevertheless, theoretical and empirical studies have shown that females may still gain indirect genetic benefits from choosing males of higher genetic quality and thereby increase their reproductive success.
Methodology/Principal Findings: We investigated two components of sexual selection in the Moor frog (Rana arvalis), precopulatory female choice between two males of different size (‘large’ vs. ‘small’), and their fertilization success in sperm competition and in isolation. Females’ showed no significant preference for male size (13 small and six large male preferences) but associated preferentially with the male that subsequently was the most successful at fertilizing her eggs in isolation. Siring success of males in competitive fertilizations was unrelated to genetic similarity with the female and we detected no effect of sperm viability on fertilization success. There was, however, a strong positive association between a male’s innate fertilization ability with a female and his siring success in sperm competition. We also detected a strong negative effect of a male’s thumb length on his competitive siring success.
Conclusions/Significance: Our results show that females show no preference for male size but are still able to choose males which have greater fertilization success. Genetic similarity and differences in the proportion of viable sperm within a males ejaculate do not appear to affect siring success. These results could be explained through pre- and/or postcopulatory choice for genetic benefits and suggest that females are able to perceive the genetic quality of males, possibly basing their choice on multiple phenotypic male traits.

Tammar wallaby mammary cathelicidins are differentially expressed during lactation and exhibit antimicrobial and cell proliferative activity

Cathelicidins secreted in milk may be central to autocrine feedback in the mammary gland for optimal development in addition to conferring innate immunity to both the mammary gland and the neonate. This study exploits the unique reproductive strategy of the tammar wallaby (Macropus eugenii) model to analyse differential splicing of cathelicidin genes and to evaluate the bactericidal activity and effect of the protein on mammary epithelial cell proliferation. Two linear peptides, Con73 and Con218, derived from the heterogeneous carboxyl end of cathelicidin transcripts, MaeuCath1 and MaeuCath7 respectively, were evaluated for antimicrobial activity. Both Con73 and Con218 significantly inhibited the growth of Staphylococcus aureus, Pseudomonas aureginosa, Enterococcus faecalis and Salmonella enterica. In addition both MaeuCath1 and MaeuCath7 stimulated proliferation of primary tammar wallaby mammary epithelial cells (WallMEC). Lactation-phase specific alternate spliced transcripts were determined for MaeuCath1 showing utilisation of both antimicrobial and proliferative functions are required by the mammary gland and the suckled young. The study has shown for the first time that temporal regulation of milk cathelicidins may be crucial in antimicrobial protection of the mammary gland and suckled young and mammary cell proliferation.

Toll like receptors play a role in general immunity, eye infection and inflammation : TLRs for nanodelivery

Dendritic cells [DCs] are potent antigen presenting cells [APC], which plays a vital role in immune system by detecting and capturing pathogens in the body. DCs perform a pivotal role in induction of T cell response. Regulation of immune response can be achieved by specific antigen [Ag] delivery to DCs. A delivery system that can efficiently target and present Ags to DCs for the purpose of anti-tumour activity is currently a topic of significant research interest. DCs are receiving attention due to their key role in anti cancer host response and due to their adjuvanic property in tumour vaccines. Role of toll like receptors [TLR] in innate immune system and their part in eventual stimulation of adaptive immunity is exploited to develop vaccines. TLR agonists in conjugation with vaccines are shown to increase therapeutic efficacy in some cases. TLRs also play a vital role in protecting the cornea from invading pathogens. Due to adverse effects in the treatment of ocular inflammations, cancer and in viral infections, an alternate approach such as the use of TLRs will solve the inquisitive question regarding side effects. The intended delivery is attained by the use of nanoparticles which in turn leads to prolonged half-life in the body. Co-delivery of Ags, TLRs and immunomodulators using nanoparticles has been demonstrated to elicit potent cellular immune responses and are currently under development of clinically applicable immunisations and vaccines.

Predatory vision : 3D imaging and the transformation of screen-space

Despite Wheatstone’s academic interests in the device, the stereoscope languished somewhat as an optical toy. Yet the advent of 3D screen-spaces for home and mass entertainment suggests today’s consumers and practitioners of screen culture hold the view that screen culture will be ‘improved’ through 3D imaging technologies. Like cinema and photography, stereoscopic 3D imaging has the potential to transform visual culture. But what is transformed, as optics and electronic imaging techniques deliver Alice in Wonderland in 3D? This paper links the advent of 3D cinema and TV to the notion that vision is itself a ‘technology of the visual’. As such, our innate binocular stereoacuity is ripe for exploitation by developers of 3D imaging technologies. I argue that contemporary 3D imaging marks an epistemological visual-perceptual shift: toward screenspaces becoming spaces for potential action. Such a shift entails seeing as doing rather than seeing as thinking. 3D imaging exploits binocular vision’s spatial acuity (stereopsis), but is effective only for objects within near distal space. The 3D effect tapers off dramatically for objects only some metres away, because the two retinal images lack significant lateral disparity (difference) to trigger stereopsis: the imagery flattens out and becomes ‘monoscopic’. Information available from conventional 2D media entails a peculiarly unspecified spatiality. Perceptually, the contents of a conventional cinematic screen are like those of a painting: they are situated neither near nor far, and constitute a shared and ambiguous visual space. Our own eyes are like those of a cat: frontally placed for predatory action. The visuality of 3D screen-spaces assumes a perceptuality of the near-by and close at hand, since this is the structure of the visible information to which stereopsis is adapted to respond. Noting the binocular acuity of predatory animals, as well as some etymological links, this paper examines the implications of perceptually ‘capturing’ the sensation of visually solid objects in one’s immediate space. Stereopsis is about decisive action within an immediate environment: but it also presupposes the single viewpoint of an active observer toward which the 3D imagery is targeted.

Transcriptional insights on the regenerative mechanics of axotomized neurons in vitro

Axotomized neurons have the innate ability to undergo regenerative sprouting but this is often impeded by the inhibitory central nervous system environment. To gain mechanistic insights into the key molecular determinates that specifically underlie neuronal regeneration at a transcriptomic level, we have undertaken a DNA microarray study on mature cortical neuronal clusters maintained in vitro at 8, 15, 24 and 48 hrs following complete axonal severance. A total of 305 genes, each with a minimum fold change of ±1.5 for at least one out of the four time points and which achieved statistical significance (one-way ANOVA, P < 0.05), were identified by DAVID and classified into 14 different functional clusters according to Gene Ontology. From our data, we conclude that post-injury regenerative sprouting is an intricate process that requires two distinct pathways. Firstly, it involves restructuring of the neurite cytoskeleton, determined by compound actin and microtubule dynamics, protein trafficking and concomitant modulation of both guidance cues and neurotrophic factors. Secondly, it elicits a cell survival response whereby genes are regulated to protect against oxidative stress, inflammation and cellular ion imbalance. Our data reveal that neurons have the capability to fight insults by elevating biological antioxidants, regulating secondary messengers, suppressing apoptotic genes, controlling ion-associated processes and by expressing cell cycle proteins that, in the context of neuronal injury, could potentially have functions outside their normal role in cell division. Overall, vigilant control of cell survival responses against pernicious secondary processes is vital to avoid cell death and ensure successful neurite regeneration.

Bacterial membrane vesicles deliver peptidoglycan to NOD1 in epithelial cells

Gram-negative bacterial peptidoglycan is specifically recognized by the host intracellular sensor NOD1, resulting in the generation of innate immune responses. Although epithelial cells are normally refractory to external stimulation with peptidoglycan, these cells have been shown to respond in a NOD1-dependent manner to Gram-negative pathogens that can either invade or secrete factors into host cells. In the present work, we report that Gram-negative bacteria can deliver peptidoglycan to cytosolic NOD1 in host cells via a novel mechanism involving outer membrane vesicles (OMVs). We purified OMVs from the Gram-negative mucosal pathogens: Helicobacter pylori, Pseudomonas aeruginosa and Neisseria gonorrhoea and demonstrated that these peptidoglycan containing OMVs upregulated NF-κB and NOD1-dependent responses in vitro. These OMVs entered epithelial cells through lipid rafts thereby inducing NOD1-dependent responses in vitro. Moreover, OMVs delivered intragastrically to mice-induced innate and adaptive immune responses via a NOD1-dependent but TLR-independent mechanism. Collectively, our findings identify OMVs as a generalized mechanism whereby Gram-negative bacteria deliver peptidoglycan to cytosolic NOD1. We propose that OMVs released by bacteria in vivo may promote inflammation and pathology in infected hosts.