microRNAs in parasite-induced liver fibrosis: from mechanisms to diagnostics and therapeutics

Chronic parasite infections in the liver pose a global threat to human and animal health, often occurring with liver fibrosis that leads to cirrhosis, liver failure, and even cancer. Hepatic fibrogenesis is a complex yet reversible process of tissue repair and is associated with various factors, including immune cells, microenvironment, gut microbiome, and interactions of the different liver cells. As a profibrogenic or antifibrogenic driver, microRNAs (miRNAs) are closely involved in parasite-induced hepatic fibrosis. This article updates the current understanding of the roles of miRNAs in hepatic fibrogenesis by parasite infections and discusses the strategies using miRNAs as candidates for diagnostics and therapeutics.

Vivaxin genes encode highly immunogenic, non-variant antigens on the Trypanosoma vivax cell-surface

Trypanosoma vivax is a unicellular hemoparasite, and a principal cause of animal African trypanosomiasis (AAT), a vector-borne and potentially fatal livestock disease across sub-Saharan Africa. Previously, we identified diverse T. vivax-specific genes that were predicted to encode cell surface proteins. Here, we examine the immune responses of naturally and experimentally infected hosts to these unique parasite antigens, to identify immunogens that could become vaccine candidates. Immunoprofiling of host serum shows that one particular family (Fam34) elicits a consistent IgG antibody response. This gene family, which we now call Vivaxin, encodes at least 124 transmembrane glycoproteins that display quite distinct expression profiles and patterns of genetic variation. We focused on one gene (viv-β8) that encodes one particularly immunogenic vivaxin protein and which is highly expressed during infections but displays minimal polymorphism across the parasite population. Vaccination of mice with VIVβ8 adjuvanted with Quil-A elicits a strong, balanced immune response and delays parasite proliferation in some animals but, ultimately, it does not prevent disease. Although VIVβ8 is localized across the cell body and flagellar membrane, live immunostaining indicates that VIVβ8 is largely inaccessible to antibody in vivo. However, our phylogenetic analysis shows that vivaxin includes other antigens shown recently to induce immunity against T. vivax. Thus, the introduction of vivaxin represents an important advance in our understanding of the T. vivax cell surface. Besides being a source of proven and promising vaccine antigens, the gene family is clearly an important component of the parasite glycocalyx, with potential to influence host-parasite interactions.

Animal African trypanosomiasis (AAT) is an important livestock disease throughout sub-Saharan Africa and beyond. AAT is caused by Trypanosoma vivax, among other species, a unicellular parasite that is spread by biting tsetse flies and multiplies in the bloodstream and other tissues, leading to often fatal neurological conditions if untreated. Although concerted drug treatment and vector eradication programmes have succeeded in controlling Human African trypanosomiasis, AAT continues to adversely affect animal health and impede efficient food production and economic development in many less-developed countries. In this study, we attempted to identify parasite surface proteins that stimulated the strongest immune responses in naturally infected animals, as the basis for a vaccine. We describe the discovery of a new, species-specific protein family in T. vivax, which we call vivaxin. We show that one vivaxin protein (VIVβ8) is surface expressed and retards parasite proliferation when used to immunize mice, but does not prevent infection. Nevertheless, we also reveal that vivaxin includes another protein previously shown to induce protective immunity (IFX/VIVβ1). Besides its great potential for novel approaches to AAT control, the vivaxin family is revealed as a significant component of the T. vivax cell surface and may have important, species-specific roles in host interactions.

Cleaved CD95L perturbs in vitro macrophages responses to Toxoplasma gondii

Toxoplasma gondii infects approximately 1-2 billion people, and manipulation of the macrophage response is critical to host and parasite survival. A cleaved (cl)-CD95L form can promote cellular migration and we have previously shown that cl-CD95L aggravates inflammation and pathology in systemic lupus erythematosus (SLE). Findings have shown that CD95L is upregulated during human infection, therefore we examined the effect of cl-CD95L on the macrophage response to T. gondii. . We find that cl-CD95L promotes parasite replication in macrophages, associated with increased arginase-1 levels, mediated by signal transducer and activator of transcription (STAT)6. Inhibition of both arginase-1 and STAT6 reversed the effects of cl-CD95L. Phospho-kinase array showed that cl-CD95L alters Janus Kinases (JAK)/STAT, mammalian target of rapamycin (mTOR), and Src kinase signals. By triggering changes in JAK/STAT cl-CD95L may limit anti-parasite effectors.

A host-independent role for Fasciola hepatica transforming growth factor-like molecule in parasite development

The trematode parasite Fasciola hepatica causes chronic infection in hosts, enabled by an immunosuppressed environment. Both host and parasite factors are known to contribute to this suggesting that avoidance of immunopathology is beneficial to both parties. We have previously characterised a parasite transforming growth factor (TGF)-like molecule, FhTLM, that interacts with host macrophages to prevent antibody-dependent cell cytotoxicity (ADCC). FhTLM is one of many described helminth TGF homologues and multiple helminths are now known to utilise host immune responses as developmental cues. To test whether, or how, F. hepatica uses FhTLM to manipulate host immunity, we initially examined its effects on the CD4 T-cell phenotype. Despite inducing IL-10, there was no induction of FoxP3 within the CD4 T-cell compartment. In addition to inducing IL-10, a wide range of chemokines were elicited from both CD4 T-cells and macrophages. However, no growth or survival advantage was conferred on F. hepatica in our co-culture system when CD4 T-cells, macrophages, or eosinophils were tested. Finally, using RNA interference we were able to verify a host-independent role for FhTLM in parasite growth. Despite the similarities of FhTLM with other described helminth TGF homologues, here we demonstrate species-specific divergence.

Trichinella spiralis cystatin, TsCstN, modulates STAT4/IL-12 to specifically suppress IFN-γ production

We have previously identified a cystatin, TsCstN, derived from the L1 stage of Trichinella spiralis and have shown that this protein is internalised in macrophages. Here we sought to address if this macrophage-TsCstN interaction could alter downstream T-cell priming. Using LPS-primed macrophages to stimulate T-cells in a co-culture system with or without TsCstN we assessed the resultant T-cell outcomes. IFN-γ, both protein and mRNA, but not IL-17A was negatively regulated by inclusion of TsCstN during macrophage priming. We identified a cell-cell contact independent change in the levels of IL-12 that led to altered phosphorylated STAT4 levels and translocation. TsCstN also negatively regulated the autonomous response in the myotubule cell line, C2C12. This work identifies a potential pathyway for L1 larvae to evade protective Th1 based immune responses and establish muscle-stage T. spiralis infection.

Does instillation of lidocaine gel following flexible cystoscopy decrease the severity of post procedure symptoms? A randomised controlled trial assessing the efficacy of lidocaine gel post flexible cystoscopy

Objective

To assess whether instillation of lidocaine gel both before and after flexible cystoscopy is more effective at reducing post procedural symptoms than instillation of lidocaine gel pre flexible cystoscopy alone. We hypothesise that inadequate urethral dwell time and dilution of lidocaine gel by the irrigation fluid during flexible cystoscopy limits its anaesthetic efficacy. Only one other study has attempted to reduce bothersome urinary symptoms through an intervention after flexible cystoscopy.

Methods

This was a randomised controlled trial in which patients were randomised 1:1 to receive lidocaine gel pre and post flexible cystoscopy (treatment) or lidocaine gel pre flexible cystoscopy only (control). Patient-reported outcome measures were used to assess symptoms and quality of life prior to cystoscopy, on day 2 and day 7 post cystoscopy.

Result

Fifty patients were divided equally between the treatment and control groups. There were no significant differences in baseline characteristics between the groups (p = 1.000). An overall symptoms variable was measured, though no significant difference was found in the distribution of responses between the groups at baseline, 2 or 7 days after the flexible cystoscopy (p = 0.423, 0.651,0.735). In the treatment group, 1 patient (4.0%) presented to a doctor for review following flexible cystoscopy, and 4 patients (16.0%) presented in the control group (p = 0.349).

Conclusion

Initial study results suggest that post-operative lidocaine does not significantly limit the exacerbation of urinary symptoms following flexible cystoscopy; however, our results are not powered to detect a small difference. We do not recommend a change in practice based on our results.

Stem cell-derived enteroid cultures as a tool for dissecting host-parasite interactions in the small intestinal epithelium

Toxoplasma gondii and Cryptosporidium spp. can cause devastating pathological effects in humans and livestock, and in particular to young or immunocompromised individuals. The current treatment plans for these enteric parasites are limited due to long drug courses, severe side effects or simply a lack of efficacy. The study of the early interactions between the parasites and the site of infection in the small intestinal epithelium has been thwarted by the lack of accessible, physiologically relevant and species-specific models. Increasingly, 3D stem cell-derived enteroid models are being refined and developed into sophisticated models of infectious disease. In this review, we shall illustrate the use of enteroids to spearhead research into enteric parasitic infections, bridging the gap between cell line cultures and in vivo experiments.

Bladder cancer in Ireland: a 21-year review

INTRODUCTION

Bladder carcinoma is one of the most commonly diagnosed cancers worldwide; however, various studies have reported on marked international variation in incidence and mortality rates. The aim of this study was to report national figures on incidence, survival and risk factors of bladder cancer. This retrospective review is the first to offer a comprehensive analysis of incidence rates, mortality and potential risk factors in the Irish population from 1994 to 2015.

METHODS

This was a retrospective study of incidence and survival trends in bladder cancer in the Irish population from 1994 to 2014 based on data from the National Cancer Registry of Ireland (NCRI). Patient demographics, pathology and survival data, as well as potential contributing factors, were studied.

RESULTS

A total of 9656 cases of bladder cancer were diagnosed from 1994 to 2015, with majority of cases occurring in males (71%). Survival decreased with increasing age, higher grade and higher stage. Bladder cancer is more common in those with a smoking history and with a higher deprivation score. Urothelial cell carcinoma was the most common pathology (95%), with the majority of patients being stage 1 or 2 (44.7%).

CONCLUSION

The overall incidence of bladder cancer in Ireland has fallen, in line with reducing smoking rates. Our data reflects international trends in incidence, survival and contributing risk factors.

Evasion of Host Immunity During Fasciola hepatica Infection

Fasciola hepatica, the common liver fluke, causes infection of livestock throughout temperate regions of the globe. This helminth parasite has an indirect lifecycle, relying on the presence of the mud snail to complete its transition from egg to definitive host (Beesley et al., Transbound Emerg Dis 65:199-216, 2017). Within the definitive host, the parasite excysts in the intestine forming a newly excysted juvenile (NEJ) and migrates via the peritoneal cavity to the liver. Disease resulting from infection can be acute or chronic depending on the host and the number of parasites present. Sheep may succumb to a fatal acute infection if the challenge of metacercariae is great enough. However, in cattle chronic disease is the most likely outcome with parasites surviving for long periods of time. Annual losses are estimated to be in the region of US$ 2000 million to the agricultural industry (Beesley et al., Transbound Emerg Dis 65:199-216, 2017). Management of the disease depends heavily on chemotherapy with triclabendazole being the drug of choice, consistent use for over 20 years has resulted in drug-resistant strains emerging worldwide (Beesley et al., Int J Parasitol 47:11-20, 2017). A more sustainable approach to control would be through vaccination and indeed a lead candidate has been identified, cathepsin L1. Despite these promising results the parasite continues to confound our own and host efforts to generate long-lasting and effective immunity. In this brief review we focus our attention on those mechanisms that the parasite utilises to circumvent the innate based defense mechanisms within the host.

An analysis of the immune compartment within bovine adipose tissue

Adipose tissue (AT) has wide functions as an active endocrine organ acting as a site of nutrient storage and thermogenesis. Recently it has been identified as having a key role in murine and human immunity and inflammation. Type 1 or type 2 immune responses and their respective cytokines have been linked to white or brown AT, respectively. Most dramatic is the involvement of type-2 innate lymphoid cells (ILC2s) in stimulating eosinophil recruitment via interleukin (IL)-13 which in turn stimulates alternative macrophage activation via IL-4/IL-13. Recruited leukocytes are capable of influencing the cellular composition and function of adipose tissue and present a route to combat human obesity, however these processes are poorly understood in ruminants. Here we have characterised the resident leukocytes populations within bovine mesenteric AT (MAT) and subcutaneous AT (SAT), compared with the corresponding mesenteric lymph node (MLN). Concurring with related studies, we find bovine AT has its own resident leukocyte populations where eosinophils and neutrophils dominate. Importantly the proportion of eosinophils or neutrophils corresponded to the adipocyte size found in both depots. Further exploration of this area may have important implications on the food production industry or could be applied to improve the course of pathogenesis during disease.

IL-17 and IL-22 elicited by a DNA vaccine encoding ROP13 associated with protection against Toxoplasma gondii in BALB/c mice

Toxoplasma gondii, an intracellular parasitic protozoan, is capable of infecting man and all warm-blooded animals. Cell-mediated immunity is vital in mounting protective responses against T. gondii infection. Recent studies have shown that T-helper (Th) 17 responses may play a key role in parasite control. In this current study, we constructed a DNA vaccine encoding T. gondii ROP13 in a pcDNA vector. Groups of BALB/c mice were immunized intramuscularly with pcROP13 or controls and challenged with the RH strain of T. gondii. The results showed that immunization with pcROP13 could elicit an antibody response against T. gondii. The expression of the canonical Th17 cytokines, interleukin (IL)-17 and IL-22, were significantly increased after immunization with pcROP13 compared with control groups ( p < 0.05). Furthermore, vaccination resulted in a significant decrease in parasite load ( p < 0.05). The induction of Th17 related cytokines, using a ROP13 DNA vaccine, against T. gondii should be considered as a potential vaccine approach for the control of toxoplasmosis.

Bovine Neonatal Monocytes Display Phenotypic Differences Compared With Adults After Challenge With the Infectious Abortifacient Agent Neospora caninum

The neonatal period represents a window of susceptibility for ruminants given the abundance of infectious challenges in their environment. Maternal transfer of immunity does not occur in utero but post-parturition, however this does not compensate for potential deficits in the cellular compartment. Here we present a cellular and transcriptomic study to investigate if there is an age-related difference in the monocyte response in cattle during intra-cellular protozoan infection. We utilized Neospora caninum, an obligate intracellular protozoan parasite that causes abortion and negative economic impacts in cattle worldwide, to study these responses. We found neonatal animals had a significant greater percentage of CD14⁺ monocytes with higher CD80 cell surface expression. Adult monocytes harbored more parasites compared to neonatal monocytes; additionally greater secretion of IL-1β was observed in neonates. Microarray analysis revealed neonates have 535 genes significantly upregulated compared to adult with 23 upregulated genes. Biological pathways involved in immune response were evaluated and both age groups showed changes in the upregulation of tyrosine phosphorylation of STAT protein and JAK-STAT cascade pathways. However, the extent to which these pathways were upregulated in neonates was much greater. Our findings suggest that neonates are more resistant to cellular invasion with protozoan parasites and that the magnitude of the responses is related to significant changes in the JAK-STAT network.

Fasciola hepatica, TGF-β and host mimicry: the enemy within

Helminths parasites undergo developmental changes and migration within their definitive host, in addition to establishing chronic infection. Essential to this is the evasion of host immune responses; the canonical Th2 response is effective at removing parasites resident in the intestine. Conversely, helminths also promote the development of antigen-specific anergy and regulation. This often limits pathology but allows parasite survival, parasite effectors mediating this are the subject of intense study. They may be useful as future vaccine targets or xenogenic therapeutics. Fasciola hepatica possesses a family of TGF-like molecules of which one member, FhTLM, is capable of promoting intrinsic and extrinsic effects. Here we review the extrinsic effects of FhTLM on the host macrophage and its consequences for protective immunity. This review also discusses the specificities of FhTLM in light a very recent description of a nematode TGF-β mimic and the effects of endogenous TGF-β.

Origins and evolution of innate lymphoid cells: Wardens of barrier immunity

The identification, in the late 2000s, of innate lymphoid cells (ILCs) as a new class of non-B, non-T lymphocytes has led to global efforts to understand their functions, plasticity and evolutionary origins and to define their place within the leucocyte family. Although this work has uncovered striking similarities in the developmental cues, lineage-specific transcription factors and functional capacities of innate and adaptive lymphocytes, it has become clear that ILCs play a unique and defining role as stewards of barrier defence and that this sets them apart from their adaptive cousins. This review will explore how the dynamic environment of barrier surfaces has shaped ILC evolution and functionality. We highlight the critical importance of the microbiome and the unique role of ILCs as environmental sensors. We reflect on how these factors may have influenced the development of ILC2s and barrier immunity in the context of exposure to helminth parasites that have been driving forces of our evolution throughout human history. Finally, we argue that the plasticity of ILC function reflects their role as first responders to environmental change.

CD95-Mediated Calcium Signaling Promotes T Helper 17 Trafficking to Inflamed Organs in Lupus-Prone Mice

CD95 ligand (CD95L) is expressed by immune cells and triggers apoptotic death. Metalloprotease-cleaved CD95L (cl-CD95L) is released into the bloodstream but does not trigger apoptotic signaling. Hence, the pathophysiological role of cl-CD95L remains unclear. We observed that skin-derived endothelial cells from systemic lupus erythematosus (SLE) patients expressed CD95L and that after cleavage, cl-CD95L promoted T helper 17 (Th17) lymphocyte transmigration across the endothelial barrier at the expense of T regulatory cells. T cell migration relied on a direct interaction between the CD95 domain called calcium-inducing domain (CID) and the Src homology 3 domain of phospholipase Cγ1. Th17 cells stimulated with cl-CD95L produced sphingosine-1-phosphate (S1P), which promoted endothelial transmigration by activating the S1P receptor 3. We generated a cell-penetrating CID peptide that prevented Th17 cell transmigration and alleviated clinical symptoms in lupus mice. Therefore, neutralizing the CD95 non-apoptotic signaling pathway could be an attractive therapeutic approach for SLE treatment.

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CD95-mediated Ca²⁺ response promotes endothelial transmigration of Th17 cells

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CD95 interacts with PLCγ1 to induce Ca²⁺ response and Th17 cell migration

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Ca²⁺ response stems from a CD95 region different from death domain

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Inhibition of the CD95-mediated Ca²⁺ response alleviates disease in lupus-prone mice

The Chronic Stages of Bovine Fasciola hepatica Are Dominated by CD4 T-Cell Exhaustion

Fasciola hepatica infection of ruminants leads to non-resolving chronic infection, as patency develops, there is switching to a TGF-β and IL-10 led response. Here, we explore the responses of CD4 T-cells within the major draining lymph nodes. We found minimal expression of Foxp3 within CD4 cells but elevated levels within the γδ (WC1⁺) population. There is a strong T-cell-intrinsic exhaustion phenotype within the hepatic lymph node (HLN) characterized by a lack of antigen-specific proliferation and cytokine secretion. CD4 T-cells recovered from the HLN had high levels of PD-1 expression and low levels of IL-2 secretion. Exogenous IL-2 partially rescued this defect; when combined with neutralization of IL-10 and TGF-β, full restoration of proliferation, and cytokine production was achieved. Moreover, there is a clear uncoupling of the mechanisms that facilitate this regulation with parasite-specific proliferation and cytokine secretion being governed by independent means. These data would suggest that there is a CD4 T-cell-intrinsic regulation in place early in chronic infection, potentially leading to failure in resistance to reinfection.

A rapid IL-17 response to Cryptosporidium parvum in the bovine intestine

Cryptosporidium parvum causes diarrhoea, due to villi damage, in livestock and humans globally. Immunity develops after repeated infections but initial infections can be severe, highlighting the importance of early infection dynamics. We have modelled early C. parvum infection in bovine jejunum biopsies. IL-17A accumulated over time peaking at 9 h post-infection, with no effect of infection on IL-1β; antibiotics positively influenced IL-17A as higher levels were found in cultures with antibiotics. Infection of primary fibroblasts resulted in lower plaque formation when fibroblasts were primed with IL-17A. Our results indicate a role for IL-17A in reducing C. parvum-dependent host cell damage.

Fasciola hepatica infection reduces Mycobacterium bovis burden and mycobacterial uptake and suppresses the pro-inflammatory response

Bovine tuberculosis (BTB), caused by Mycobacterium bovis, has an annual incidence in cattle of 0.5% in the Republic of Ireland and 4.7% in the UK, despite long‐standing eradication programmes being in place. Failure to achieve complete eradication is multifactorial, but the limitations of diagnostic tests are significant complicating factors. Previously, we have demonstrated that Fasciola hepatica infection, highly prevalent in these areas, induced reduced sensitivity of the standard diagnostic tests for BTB in animals co‐infected with F. hepatica and M. bovis. This was accompanied by a reduced M. bovis‐specific Th1 immune response. We hypothesized that these changes in co‐infected animals would be accompanied by enhanced growth of M. bovis. However, we show here that mycobacterial burden in cattle is reduced in animals co‐infected with F. hepatica. Furthermore, we demonstrate a lower mycobacterial recovery and uptake in blood monocyte‐derived macrophages (MDM) from F. hepatica‐infected cattle which is associated with suppression of pro‐inflammatory cytokines and a switch to alternative activation of macrophages. However, the cell surface expression of TLR2 and CD14 in MDM from F. hepatica‐infected cattle is increased. These findings reflecting the bystander effect of helminth‐induced downregulation of pro‐inflammatory responses provide insights to understand host‐pathogen interactions in co‐infection.

CD95 and the MRL-lpr Mouse Model

CD95 (Fas-ligand) is a key mediator of cell death in multiple setting, thus its loss within the MRL-lpr (Fas^lpr) homozygote mice results in spontaneous autoimmunity. This is characterized by the development of arthritis and immune complex glomerulonephrosis making this strain a useful model for studying systemic lupus erythematosus. Herein we describe a method to exploit the heterozygote offspring of this strain in a model to study the effects of a CD95L blocking peptide on lupus-like disease in vivo.

A Trematode Parasite Derived Growth Factor Binds and Exerts Influences on Host Immune Functions via Host Cytokine Receptor Complexes

The trematode Fasciola hepatica is responsible for chronic zoonotic infection globally. Despite causing a potent T-helper 2 response, it is believed that potent immunomodulation is responsible for rendering this host reactive non-protective host response thereby allowing the parasite to remain long-lived. We have previously identified a growth factor, FhTLM, belonging to the TGF superfamily can have developmental effects on the parasite. Herein we demonstrate that FhTLM can exert influence over host immune functions in a host receptor specific fashion. FhTLM can bind to receptor members of the Transforming Growth Factor (TGF) superfamily, with a greater affinity for TGF-β RII. Upon ligation FhTLM initiates the Smad2/3 pathway resulting in phenotypic changes in both fibroblasts and macrophages. The formation of fibroblast CFUs is reduced when cells are cultured with FhTLM, as a result of TGF-β RI kinase activity. In parallel the wound closure response of fibroblasts is also delayed in the presence of FhTLM. When stimulated with FhTLM blood monocyte derived macrophages adopt an alternative or regulatory phenotype. They express high levels interleukin (IL)-10 and arginase-1 while displaying low levels of IL-12 and nitric oxide. Moreover they also undergo significant upregulation of the inhibitory receptor PD-L1 and the mannose receptor. Use of RNAi demonstrates that this effect is dependent on TGF-β RII and mRNA knock-down leads to a loss of IL-10 and PD-L1. Finally, we demonstrate that FhTLM aids newly excysted juveniles (NEJs) in their evasion of antibody-dependent cell cytotoxicity (ADCC) by reducing the NO response of macrophages—again dependent on TGF-β RI kinase. FhTLM displays restricted expression to the F. hepatica gut resident NEJ stages. The altered fibroblast responses would suggest a role for dampened tissue repair responses in facilitating parasite migration. Furthermore, the adoption of a regulatory macrophage phenotype would allow for a reduced effector response targeting juvenile parasites which we demonstrate extends to an abrogation of the ADCC response. Thus suggesting that FhTLM is a stage specific evasion molecule that utilises host cytokine receptors. These findings are the first to clearly demonstrate the interaction of a helminth cytokine with a host receptor complex resulting in immune modifications that facilitate the non-protective chronic immune response which is characteristic of F. hepatica infection.

Parasitic worms, helminths, can cause long-lived chronic infection in many hosts that they infection. The liver fluke, Fasciola hepatica, is one such parasite causing global infection of both humans and animals. F. hepatica exerts an influence over the immune system such that it avoids effector mechanisms and prevents the development of effective immunity. Here we characterise a molecule—FhTLM—derived from juvenile parasites that is similar to the regulatory cytokine TGF-β. We show that FhTLM will bind to host TGF-β receptors with a reduced affinity when compared with mammalian TGF-β. Despite this FhTLM can induce Smad2/3 signalling in host leukocytes, which is key to initiating gene transcription. Phenotypically FhTLM causes fibroblasts to slow their growth and replication response resulting in slower wound healing. Importantly FhTLM induces a macrophage phenotype that resembles a regulatory macrophage phenotype identified in other species undergoing helminth infection. Finally we Our work highlights the potential of FhTLM to play important roles in controlling host immunity when initially infected with juvenile parasites, thereby preventing the development of effective immunity.

TGF-β superfamily members from the helminth Fasciola hepatica show intrinsic effects on viability and development

The helminth Fasciola hepatica causes fasciolosis throughout the world, a major disease of livestock and an emerging zoonotic disease in humans. Sustainable control mechanisms such as vaccination are urgently required. To discover potential vaccine targets we undertook a genome screen to identify members of the transforming growth factor (TGF) family of proteins. Herein we describe the discovery of three ligands belonging to this superfamily and the cloning and characterisation of an activin/TGF like molecule we term FhTLM. FhTLM has a limited expression pattern both temporally across the parasite stages but also spatially within the worm. Furthermore, a recombinant form of this protein is able to enhance the rate (or magnitude) of multiple developmental processes of the parasite indicating a conserved role for this protein superfamily in the developmental biology of a major trematode parasite. Our study demonstrates for the first time the existence of this protein superfamily within F. hepatica and assigns a function to one of the three identified ligands. Moreover further exploration of this superfamily may yield future targets for diagnostic or vaccination purposes due to its stage restricted expression and functional role.

The clinic-pathological characteristics of prostate cancer in an Irish subpopulation with a serum PSA less than 4.0ng/ml

Background:

Prostate specific antigen (PSA) has been used as a biomarker for prostate cancer for the last 20 years. Traditionally, a serum PSA <4 ng/ml has been used as a general cut-off between normal and abnormal readings. There is evidence to demonstrate that men with a normal serum PSA can develop prostate cancer. The aim of this study was to investigate the clinico-pathological features of prostate cancer in a non-screened Irish cohort with serum PSA <4 ng/ml.

Methods:

A retrospective analysis was performed of all patients who underwent radical retropubic prostatectomy (RRP) in a tertiary referral unit over a 10-year period (2000–2010). Clinico-pathological characteristics were collated including those from trans-rectal ultrasound-guided (TRUS) prostate biopsies and radical prostatectomy specimens.

Results:

Between 2000 and 2010, 651 men underwent an RRP, with 43 (6.6%) having a serum PSA <4 ng/ml. The median PSA was 3.2 ng/ml (range 0.8–4.0). Nineteen (44.2%) had palpable disease on direct rectal examination (DRE). Following prostatectomy, 28 (65.12%) had Gleason 6 disease, 14 (32.56%) had Gleason 7 disease and one (2.32%) had Gleason 8 disease. Five (11.63%) patients were upgraded from TRUS biopsy to final histopathology. Six (13.95%) patients had pathological evidence of extracapsular extension on final pathology. Three (6.98%) patients experienced biochemical recurrence and received salvage radiation therapy after a median time of 24 months. The median follow-up was 106 months (range 36–158). Twenty (46.51%) patients had a first-degree family history of prostate cancer.

Conclusions:

A PSA cut-off of 4 ng/ml has commonly been used in the detection of prostate cancer. Our study emphasizes that this cut-off is inappropriate and that no specific level of PSA can be used. Management decisions need to be individualized based on index of suspicion with concomitant counselling and rectal examination.

IL-33 is more potent than IL-25 in provoking IL-13-producing nuocytes (type 2 innate lymphoid cells) and airway contraction

BACKGROUND

IL-25 and IL-33 belong to distinct cytokine families, but experimental mouse studies suggest their immunologic functions in type 2 immunity are almost entirely overlapping. However, only polymorphisms in the IL-33 pathway (IL1RL1 and IL33) have been significantly associated with asthma in large-cohort genome-wide association studies.

OBJECTIVE

We sought to identify distinct pathways for IL-25 and IL-33 in the lung that might provide insight into their roles in asthma pathogenesis and potential for therapeutic intervention.

METHODS

IL-25 receptor-deficient (Il17rb(-/-)), IL-33 receptor-deficient (ST2, Il1rl1(-/-)), and double-deficient (Il17rb(-/-)Il1rl1(-/-)) mice were analyzed in models of allergic asthma. Microarrays, an ex vivo lung slice airway contraction model, and Il13(+/eGFP) mice were then used to identify specific effects of IL-25 and IL-33 administration.

RESULTS

Comparison of IL-25 and IL-33 pathway-deficient mice demonstrates that IL-33 signaling plays a more important in vivo role in airways hyperreactivity than IL-25. Furthermore, methacholine-induced airway contraction ex vivo increases after treatment with IL-33 but not IL-25. This is dependent on expression of the IL-33 receptor and type 2 cytokines. Confocal studies with Il13(+/eGFP) mice show that IL-33 more potently induces expansion of IL-13-producing type 2 innate lymphoid cells, correlating with airway contraction. This predominance of IL-33 activity is enforced in vivo because IL-33 is more rapidly expressed and released in comparison with IL-25.

CONCLUSION

Our data demonstrate that IL-33 plays a critical role in the rapid induction of airway contraction by stimulating the prompt expansion of IL-13-producing type 2 innate lymphoid cells, whereas IL-25-induced responses are slower and less potent.

Survival after incidental prostate cancer diagnosis at transurethral resection of prostate: 10-year outcomes

BACKGROUND

The most appropriate management of incidental prostate cancers diagnosed at transurethral resection of prostate has been debated. It is important to determine the long-term outcomes to establish an appropriate management in patients with incidental prostate cancer.

AIMS

We aim to determine 10-year survival and to identify the factors of worse prognosis of incidental prostate cancers diagnosed at transurethral resection of prostate.

METHODS

A retrospective analysis of patients with pT1a-pT1b prostate cancers diagnosed between 1998 and 2003. Medical notes, PSA and pathology results were reviewed. Overall and cancer specific survival was calculated at mean 10-year follow-up.

RESULTS

Sixty patients with incidental prostate cancer were identified (pT1a = 18, pT1b = 42). Fifty-one percents of the patients were managed on a watchful waiting strategy with overall 84% survival and 9.7% cancer specific mortality. Twenty patients (all with pT1b) received hormone therapy. Overall survival in this cohort was 50% with 20% cancer specific mortality. Nine patients received curative therapy (Radical prostatectomy = 4, Radiotherapy = 5). In this group, overall survival was 88% with no cancer specific mortality.

CONCLUSIONS

Stage pT1a disease and preoperative low PSA were associated with favourable survival. However, for pT1b and/or high Gleason score (≥7), mortality was comparatively higher. Hence, patients with high Gleason score and/or pT1b disease should be considered for curative therapy. Additionally, active surveillance may have a role in selected men with incidental prostate cancer.

Reciprocal expression of IL-25 and IL-17A is important for allergic airways hyperreactivity

BACKGROUND

Interleukin (IL)-25 (IL-17E) is a potent inducer of the type-2 immune effector response. Previously we have demonstrated that a neutralizing anti-IL-25 antibody, given during the establishment of ovalbumin-specific lung allergy, abrogates airways hyperreactivity.

OBJECTIVE

Blocking IL-25 results in the suppression of IL-13, a cytokine known to exacerbate pulmonary inflammation, and an unexpected reciprocal increase in IL-17A. The role of IL-17A in asthma is complex with reports of both pro-inflammatory and anti-inflammatory functions. Our aim was to determine the influence of IL-17A in regulating IL-25-dependent lung allergy.

METHOD

Neutralizing antibodies to IL-25 and/or IL-17A were administered during an experimental model of allergic asthma. Bronchoalveolar cell infiltrates and lung cytokine production were determined to assess lung inflammation. Invasive plethysmography was undertaken to measure lung function.

RESULTS

Neutralization of IL-25 correlated with a decrease in IL-13 levels and an increase in IL-17A production, and an accompanying prevention of airway hyperresponsiveness (AHR). Notably, the blocking of IL-17A reversed the protective effects of treating with anti-IL-25 antibodies, resulting in the re-expression of several facets of the lung inflammatory response, including IL-13 and eotaxin production, eosinophilia and AHR. Using mice over-expressing IL-13 we demonstrate that treatment of these mice with anti-IL-25 fails to suppress IL-13 levels and in turn IL-17A levels remain suppressed.

CONCLUSIONS AND CLINICAL RELEVANCE

IL-13 is known to be an important inducer of lung inflammation, causing goblet cell hyperplasia and promoting airways hyperreactivity. Our data now demonstrate that IL-13 also plays an important role in the genesis of lung inflammation downstream of IL-25 by suppressing a protective IL-17A response. These findings also highlight the important reciprocal interplay of the IL-17 family members, IL-25 and IL-17A, in regulating allergic lung responses and suggest that the balance of IL-17A, together with IL-25, will be an important consideration in the treatment of allergic asthma.

Toxoplasma gondii peroxiredoxin promotes altered macrophage function, caspase-1-dependent IL-1β secretion enhances parasite replication

Alternatively activated macrophages (AAM) are a key feature Th2 immunity and have been associated with a variety of roles during helminth infection. The role this cell subset plays in protzoan infection remain relatively unexplored, herein we describe the effects of a redox enzyme (rTgPrx) derived from Toxoplasma gondii on murine macrophage phenotype in vitro. RTgPrx has been previously associated with the maintainence of parasite oxidative balance. Here our experiments show that rTgPrx promotes AAM as indicated by high arginase-1 (arg-1), YM1 and FIZZ expression via both signal transducer and activator of transcription (STAT)6-dependent and -independent mechanisms. Additionally rTgPrx treatment reduced caspase-1 activity and IL-1β secretion, while simultaneously increasing IL-10 release. Furthermore the in vitro replication of T. gondii (RH strain) was enhanced when macrophages were treated with rTgPrx. This is in contrast with the previously described effects of a Plasmodium berghei ANKA 2-cys-peroxiredoxin that promotes pro-inflammatory cytokine production. These results highlight the role of T. gondii derived redox enzymes as important immune modulators and potentially indicate a role for AAM in modulating immunopathology and promoting parasite replication during T. gondii infection.

A retrospective investigation into risk factors of sarcoptic mange in dogs

This retrospective study of sarcoptic mange in dogs aimed to identify risk factors for this disease and determine their influence on treatment outcome. Data regarding dog demographics, clinical presentation, diagnostic method, treatment, and outcome were analyzed. No statistical association was found between sex and incidence of sarcoptic mange. However, age of dogs was found to be a risk factor which could increase the chances of dogs contracting sarcoptic mange. The results indicate that the disease predominantly affects young dogs, of all breeds and both sexes, implicating age-related immunity. The most common clinical feature reported was pruritus, with the ear margins preferentially affected. Additionally, contact with other animals played an important role in occurrence of the disease indicating the highly transmissible nature of the disease.

Coordinating innate and adaptive immunity in Fasciola hepatica infection: implications for control

The helminth parasite Fasciola hepatica is responsible for major economic losses in agriculture throughout temperate regions of the globe. Control measures are heavily reliant on chemotherapy resulting in the emergence of drug resistant parasite populations. Novel control strategies based on vaccination ultimately require a deeper knowledge of host-parasite interactions. Herein we discuss recent advances in the understanding of the immune response to F. hepatica placing them in context with previous knowledge and developments from other model systems. Advances in RNAi and proteomics in the context of helminth research should make target identification and characterisation more rapid. In parallel, integration of these technologies with better immunological understanding will be crucial for future research into F. hepatica control measures.

IL-10 and TGF-beta1 are associated with variations in fluke burdens following experimental fasciolosis in sheep

Infection with Fasciola hepatica causes an economically important disease in ruminants. Variability in parasite load may indicate innate differences in the host immune system. This study aimed to investigate the immunological mechanisms that are associated with variability in parasite burden following experimental F. hepatica infection in cross-bred sheep. Of a total of 16 animals, four were randomly chosen as uninfected controls, and the remainder infected with 100 viable metacercariae. Uninfected animals were used as the control group for evaluation of cytokine gene expression levels. For comparative analysis, specific animals were selected on the basis of extremes of fluke burdens, and were categorised into light (n = 4) and heavy burdened (n = 3) cohorts. Serum antibody levels, haematological parameters, and expression of IL-4 and IFN-gamma genes in hepatic lymph nodes were equivalent in both groups. However, significant differences in mitogen-specific lymphocyte proliferation in vitro and in expression of TGF-beta1 and IL-10 genes in hepatic lymph nodes were observed at acute and chronic phases of infection, respectively. These results provide useful information in developing further understanding of natural resistance to fasciolosis in sheep.

Co-Infection of cattle with Fasciola hepatica and Mycobacterium bovis- immunological consequences

Fasciola hepatica, the liver fluke, is a common parasite of cattle in much of the world. Previously, we have shown that cattle infected with F. hepatica have altered responsiveness (delayed type hypersensitivity reaction and cytokine responses) to M. bovis BCG infection. We hypothesized that co-infection with F. hepatica would, likewise, alter the immune response of cattle to virulent M. bovis infection, with possible implications for disease diagnosis and disease progression. Our previous work with F. hepatica/M. bovis BCG-infected cattle demonstrated a reduction in interferon (IFN)-gamma responsiveness in co-infected animals. Similar findings are reported here with virulent M. bovis following aerosol infection. The epidemiological significance of these findings, also, require exploration, particularly in view of the considerable resources devoted to the diagnosis and eradication of bovine tuberculosis, and the high prevalence of F. hepatica infection in areas where eradication has proved difficult.

The roles of IL-10 and TGF-beta in controlling IL-4 and IFN-gamma production during experimental Fasciola hepatica infection

Hosts infected with Fasciola hepatica experience immunosuppression during the acute and chronic phases of the disease. This immunosuppression may allow parasite survival in the face of an ongoing immune response. In bovine hosts early IL-4 and continued IgG1 production is one of the few remaining features of the characteristic type 0/2 helper (Th0/2) response present in the chronic stage of disease. Here we demonstrate elevated levels of parasite-specific, in vitro peripheral blood mononuclear cell (PBMC)-derived transforming growth factor (TGF)-beta1 from the early phases of infection and increasing levels of IL-10 as the infection becomes chronic. In vitro neutralisation of these cytokines during culture of PBMCs from experimentally-infected cattle increased IL-4 and IFN-gamma production in response to parasite-specific and non-specific stimulation. At 4 weeks p.i. neutralisation of TGF-beta results in an increase in parasite driven IL-4, while also having a greater role, compared with IL-10, in influencing specific and non-specific IFN-gamma. At 12 weeks p.i. ex vivo parasite driven IL-4 was not restored by inhibiting either IL-10 or TGF-beta. However IL-10 influenced both parasite-specific and non-specific IFN-gamma production at this time. This highlights the roles of IL-10 and TGF-beta in fasciolosis, however the cellular sources of these have yet to be defined. This suggests that suppression of IFN-gamma production by parasite molecules occurs during infection and it is possible that the suppression of IFN-gamma production may mediate parasite survival in this disease.

Alternative activation of ruminant macrophages by Fasciola hepatica

The helminth parasite, Fasciola hepatica, has a worldwide distribution and infects a wide variety of mammalian hosts, including ruminants and man. In response to infection, these hosts mount a type 2 helper (Th2) response that is highly polarized and results in the downregulation of type 1 helper (Th1) mechanisms. In a murine macrophage model F. hepatica induces alternative activation of macrophages. These macrophages differ from classically activated cells in that they preferentially use arginase instead of inducible nitric oxide synthase (iNOS) for metabolism of nitrogen. In this study we sought to characterize macrophage phenotype following stimulation of the ovine cell line MOCL7 with recombinant F. hepatica enzymes and crude parasite extracts. An in vitro model using the MOCL7 cell line was established and arginase levels in cells were used to determine the activation status of cells. Stimulation of this cell-line in vitro with F. hepatica products induces alternative activation. We have also found a chitinase-like protein in supernatants which is capable of differentiating alternatively activated from classically activated macrophages.

Experimental Fasciola hepatica infection alters responses to tests used for diagnosis of bovine tuberculosis

Fasciola hepatica is a prevalent helminth parasite of livestock. Infection results in polarization of the host's immune response and generation of type 2 helper (Th2) immune responses, which are known to be inhibitory to Th1 responses. Bovine tuberculosis (BTB) is a bacterial disease of economic and zoonotic importance. Control polices for this disease rely on extensive annual testing and a test-and-slaughter policy. The correct diagnosis of BTB relies on cell-mediated immune responses. We established a model of coinfection of F. hepatica and Mycobacterium bovis BCG to examine the impact of helminth infection on correct diagnosis. We found the predictive capacity of tests to be compromised in coinfected animals and that F. hepatica infection altered macrophage function. Interleukin-4 and gamma interferon expression in whole-blood lymphocytes restimulated in vitro with M. bovis antigen was also altered in coinfected animals. These results raise the question of whether F. hepatica infection can affect the predictive capacity of tests for the diagnosis of BTB and possibly also influence susceptibility to BTB and other bacterial diseases. Further studies on the interplay between helminth infection and BTB are warranted.

Cross-validated factor structures and factor-based subscales for PASS and PASSING

Program Analysis of Service Systems (PASS 3) and Program Analysis of Service Systems' Implementation of Normalization Goals (PASSING) are used internationally to assess service quality in mental retardation and other fields. In two studies, we derived and cross-validated the factor structures of these program evaluation instruments. In Study 1, based on 626 PASS 3 evaluations, four factors provided a good fit to the cross-validation data. In Study 2, based on 633 PASSING evaluations, three factors furnished a good fit to the cross-validation data. Similarities between the two factor structures, parallels with the structural and functional service dimensions emphasized in ecological approaches to evaluation, and practical uses in program evaluation of subscales based on the factors were discussed.

Endoscopic laser ablation of the prostate (ELAP): changes in magnetic resonance imaging and clinical outcome at 1 year

OBJECTIVE

To assess the ability of magnetic resonance imaging (MRI) to detect tissue changes immediately after laser ablation of the prostate and to correlate these changes with clinical outcome by detecting changes that may improve the outcome by allowing the laser dosimetry to be adjusted during therapy by monitoring effects on gland morphology.

PATIENTS AND METHODS

Eight men with proven bladder outlet obstruction had a standard four-quadrant laser ablation of the prostate with a side-firing non-contact fibre. MRI scans were performed before, during and immediately after treatment and again after one week, 3 months and one year.

RESULTS

The clinical outcome was a decrease in the American Urological Association (AUA)-7 symptom score from a pre-operative mean of 21.3-12.0 1 year after treatment and a corresponding increase in peak urinary flow rates from a mean of 8.9 mL/s to 12.3 mL/s. Immediately after treatment, MRI showed marked swelling of the gland (mean increase in volume 34%, range 12-75) with the loss of internal architecture. A low-signal thin periurethral band was present in six of the eight patients after 1 week and was replaced by a wider periurethral ring at 3 months in four of the six patients. No patient had evidence of prostatic cavitation after treatment or a significant reduction in prostate volume at 1 year.

CONCLUSION

MRI can detect tissue changes after laser ablation of the prostate. The marked swelling seen on MRI immediately after laser prostatectomy may explain the delayed improvement in symptoms. The periurethral ring may indicate the depth to which laser energy has an effect on the tissue and could delineate an area of necrosis. The lack of cavitation at one year questions the durability of the effect of laser treatment delivered in this way.

Long-term follow-up of patients with erectile dysfunction commenced on self injection with intracavernosal papaverine with or without phentolamine

OBJECTIVES

To determine the usage, complications and satisfaction with intracavernosal agents in patients with erectile dysfunction commenced on self-injection treatment at home.

PATIENTS AND METHODS

A total of 344 patients who had commenced intracavernosal treatment before December 1992 and had requested a repeat prescription were sent a questionnaire to determine the usage, complications, satisfaction and reasons for discontinuing treatment.

RESULTS

Replies were received from 216 patients; of those who replied, only 126 were still using the treatment. The mean duration of treatment was 3.9 years in those continuing treatment. Whilst satisfaction ratings were high in those continuing therapy, most patients had experienced some side-effects.

CONCLUSION

The long-term follow-up revealed a high attrition rate and a significant number of complications. Patients receiving auto-injection therapy should be offered regular long-term follow-up.

Endoscopic laser ablation of the prostate: MR appearances during and after treatment and their relation to clinical outcome

OBJECTIVE

Endoscopic laser ablation is a new treatment for benign prostatic hypertrophy. The objectives of this study were to determine the appearances of the prostate on MR images obtained during, 1 week after, and 3 months after this procedure and to determine if a correlation exists between the MR findings and the clinical outcome. Such appearances could then be used to guide the application of laser energy during the procedure in order to optimize the clinical result.

SUBJECTS AND METHODS

Eight consecutive men 58-74 years old with symptoms of bladder outflow obstruction caused by benign prostatic hypertrophy underwent endoscopic laser ablation of the prostate under spinal or epidural anaesthesia. Imaging was done on a 0.5-T Picker Asset system with an endorectal receiver coil and conventional T1-weighted spin-echo, T2-weighted spin-echo, and gradient-recalled-echo sequences. T1-weighted magnetization transfer images were obtained in three patients. Images were obtained preoperatively, after ablation of the left-sided quadrants, immediately after completion of the procedure, and 1 week and 3 months later. Preoperative and 3-month postoperative symptom scores, peak urine flow rates, and bladder residual volumes were studied. Images were visually assessed for signal-intensity changes and the presence of cavitation by three radiologists in conference. The results were quantitatively analyzed by measuring prostatic volumes on the gradient-recalled-echo images and by measuring the width and area of regions of signal-intensity change on the T2-weighted images.

RESULTS

MR images made immediately after treatment showed an increase in the volume of the prostate (mean, 34%) and a poorly defined, low-signal-intensity region around the urethra on the T2-weighted images in six patients. This probably represented coagulative necrosis. The prostate was smaller on MR images made 1 week after treatment, and after 3 months the prostate returned to its preoperative size. After 1 week, the low-signal-intensity periurethral region on the T2-weighted images was less obvious, and at 3 months it was replaced in four patients by a well-demarcated low-signal-intensity ring on the T2-weighted and gradient-recalled-echo images. No evidence of cavity formation in the prostate was seen on MR images in any patient. Symptom scores and peak urinary flow rates improved after 3 months, with a significant difference between the mean increase in symptom scores in the patients with and without the periurethral changes seen immediately after treatment. However, we found no significant difference between the mean increase in peak urinary flow rates in the patients with and without periurethral changes seen either immediately or at 3 months after treatment. No statistically significant correlation was found between the amount of prostatic swelling and the improvement in symptom scores or peak urine flow rates.

CONCLUSION

In patients who have had laser prostatectomy, MR imaging shows significant immediate glandular swelling, which may account for the delayed improvement in symptoms reported with this technique. The presence of the periurethral changes immediately after treatment was correlated with a subsequent improvement in symptom scores. After 3 months, no cavity could be seen in the prostate. This may account for the poorer long-term clinical outcome reported with endoscopic laser ablation of the prostate compared with transurethral prostatectomy.

Quality of institutional and community human service programs in Canada and the United States

This methodological and substantive study was based on Wolfensberger and Thomas' (1983) Program Analysis of Service Systems' Implementation of Normalization Goals (PASSING), a program evaluation method used by teams of trained raters to assess the quality of human service programs. PASSING is based on Social Role Valorization, an internationally influential theoretical and philosophical approach to structuring human services, particularly services for persons with handicaps or other potentially devaluing conditions. The data for this study were derived from a sample of 213 programs evaluated with PASSING during 1983-88 in Canada (45%), the United States (51%), and the United Kingdom (4%). The programs served mainly mentally retarded persons (40%), subgroups of clients with "mixed" (different) impairments and conditions (38%), or psychiatrically impaired persons (6%). The results showed that PASSING has adequate internal consistency and interrater reliability and yields data suitable for statistical treatment with interval-level, parametric procedures. The average level of quality of services in the sample on the total PASSING scale and its five subscales (Program Relevance, Intensity, Integrativeness, Image Projection, and Felicity) was only modest, however. Community group residences (n = 77) were of significantly better quality than community vocational programs (n = 56), and both were superior to institutional residences (n = 20). Also, Canadian programs (n = 76) were of significantly better quality than U.S. programs (n = 77). An outstanding vocational program that was not part of the study sample was used to illustrate concrete ways in which the quality of many human service programs could be greatly improved, typically at little cost.

Single dose oral H2-antagonists do not affect plasma lidocaine levels in the parturient

We studied whether a single oral dose of either cimetidine or ranitidine affects the disposition of epidurally administered lidocaine in the parturient. Patients given epidural analgesia for elective caesarean section were randomly pretreated with either cimetidine 400 mg (n = 5), ranitidine 150 mg (n = 7) or no H2 receptor antagonist (n = 5). Following the administration of 400 mg of lidocaine 2% with adrenaline 1:200,000 no difference was found in peak plasma lidocaine levels or area under the plasma concentration/time curve (AUC) between the three groups. A single oral dose of cimetidine or ranitidine does not affect lidocaine disposition in the obstetric patient.

Effect of intravenous cimetidine on lignocaine disposition during extradural caesarean section

We studied whether an intravenous bolus of cimetidine altered the disposition of extradurally administered lignocaine in the parturient. Mothers who requested extradural analgesia for elective Caesarean section were randomly pretreated with either cimetidine 200 mg intravenously (n = 5) or no H2-receptor antagonist (n = 5). No difference was found between peak plasma lignocaine levels or area under the plasma concentration/time curve between the two groups after administration of 6 mg/kg lignocaine 2% with adrenaline 1:200,000. There was no evidence for an effect of a single intravenous dose of cimetidine on lignocaine disposition in the obstetric patient. In addition, the extradural administration of 6 mg/kg lignocaine produces plasma levels well below toxic levels.

A comparison between propofol and thiopentone as induction agents in obstetric anaesthesia

Two comparable series of 21 patients who had elective Caesarean section had general anaesthesia induced by thiopentone sodium 4.53 (SD 0.65) mg/kg or propofol 2.15 (SD 0.26) mg/kg. Maintenance was similar for both groups. Blood pressure was lower in the propofol group during the induction-delivery interval. Umbilical/maternal vein ratios for thiopentone and propofol were 8.5 and 7.2 respectively. Infant wellbeing as judged by Apgar score and cord blood analysis showed little difference between the two induction agents. Factors associated with uterine relaxation and bleeding were similar in the two groups.

Australian Stringhalt--epidemiological, clinical and neurological investigations

An investigation of 78 cases of typical Australian Stringhalt from 52 properties in Victoria was carried out from 1985 to 1987. Horses were either examined in the field (n = 52), referred to the Veterinary Clinical Centre (n = 13) or clinical details were obtained verbally (n = 13). In addition 10 cases of false or atypical stringhalt were examined. Detailed soil and pasture analysis was carried out on 14 properties where Australian Stringhalt had occurred. Information was also obtained on epidemiology of the condition from a survey of practitioners. Fifty of the 52 cases examined in the field occurred in horses that were dependent upon poor quality unimproved dry pasture. In all but a few cases, there was no pasture improvement or fertiliser application, leading to the development of weed-dominated pastures, particularly by flatweed, Hypochaeris radicata. The range of clinical signs exhibited by horses with Australian Stringhalt was described and a grading system proposed to classify horses according to severity of signs. Laryngeal abnormalities were present in 10 of 11 cases examined endoscopically and these horses exhibited increased electromyographic (EMG) activity in the long digital extensor muscle at rest and during hindlimb flexion. To a large extent, the EMG changes disappeared and digital extensor muscle atrophy improved in two horses that were monitored to recovery. Deep peroneal nerve conduction studies in four horses with Australian Stringhalt showed a substantial reduction in nerve conduction velocity and when stimulated at 50 Hz were unable to sustain activation of the long digital extensor muscle. EMG and evoked responses appeared to be sensitive indicators of the state of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of single-dose omeprazole on intragastric acidity and volume during obstetric anaesthesia

Various antacid or antisecretory agents are used to reduce the risk to patients of aspiration of gastric contents during general anaesthesia and a trial of the gastric proton pump inhibitor, omeprazole, is reported here. Twenty women admitted for elective Caesarean section under general anaesthesia received a single 80-mg oral omeprazole dose at 2000 hours on the evening before surgery. Intragastric pH and volume were measured immediately after induction of anaesthesia and on completion of surgery. Eighty-five percent of pH measurements at induction and extubation and 80% and 95% of volume measurements at induction and extubation respectively met the defined success criteria (pH greater than or equal to 2.5, volume less than 25 ml). Omeprazole treatment was well tolerated by the women and Apgar scores and subsequent progress of the babies were acceptable. These results indicate that gastric acidity and volume were acceptable in the majority of women after omeprazole treatment, but the interval from drug administration to induction of anaesthesia may have been too long in some cases and resulted in unacceptably low pHs.