Changes in Multidisciplinary Tracheostomy Team Practice Over Time.

Aim Increasing numbers of tracheostomy patients are discharged from the Intensive Care Unit (ICU) to general hospital wards. There is evidence that a Multidisciplinary Tracheostomy Team (MTT) can have a positive impact on the care of tracheostomy patients discharged from the ICU. We compared tracheostomy management and patient outcome in two time periods, at the start of our MTT practice in 2009-2011 and again in 2017. Methods In a retrospective audit, we compared tracheostomy management and patient outcome in 117 patients who had a tracheostomy in 2009-2011 with 81 patients who had a tracheostomy in 2017. Results The duration of tracheostomy cannulation was significantly shorter (21 vs 31 days, p=0.0005) in 2017 compared to 2009-2011. A Mini-Trach was used after tracheostomy decannulation in 56 of the 81 (69%) tracheostomy patients in 2017. Conclusions The continued development of our MTT service over 8 years was associated with a significantly shorter duration of tracheostomy cannulation and the introduction of Mini-Trach use after tracheostomy decannulation. These results support the importance of maintaining an active MTT service to manage tracheostomy patients after discharge from the ICU.

The Development of a National Paediatric Psycho-Oncology Service.

Aims To investigate the psychological care provided to children and young adolescents with cancer and their families within the National Children's Cancer Service (NCCS), Ireland, in respect of the national and international standards of care. Methods A retrospective audit of 316 referrals made over 32 months by the NCCS to the psychology service in malignant haematology and oncology was performed. Results The audit revealed that out of 316 patients, a yearly average of 189 (50%) of urgently referred patients received psychological support within the NCCS between January 2013 and August 2016. Furthermore only 20 (22%) undergoing haematopoietic stem cell transplantation (HSCT), 14 (22%) referred to the paediatric palliative care team, and 84 (62%) of teenage patients received psychological input during this timeframe. Conclusion The audit revealed that the current psychology service provision is failing to meet the international standards of care. Due to the data provided by this audit, in conjunction with a clinical risk assessment of the service, funds for the post of principal psychologist have been secured. Further psychology posts (HSCT, late-effects and neuropsychology), and development of the psycho-oncology model of care are required to ensure equality of access and evidence-based psychological care for all children with cancer.

Osteoarthritis-associated basic calcium phosphate crystals alter immune cell metabolism and promote M1 macrophage polarization.

OBJECTIVE: A number of studies have demonstrated that molecules called 'alarmins' or danger-associated molecular patterns (DAMPs), contribute to inflammatory processes in the OA joint. Metabolic reprogramming of immune cells, including macrophages, is emerging as a prominent player in determining immune cell phenotype and function. The aim of this study was to investigate if basic calcium phosphate (BCP) crystals which are OA-associated DAMPs, impact on macrophage phenotype and metabolism. METHODS: Human monocyte derived macrophages were treated with BCP crystals and expression of M1 (CXCL9, CXCL10) and M2 (MRC1, CCL13)-associated markers was assessed by real-time PCR while surface maturation marker (CD40, CD80 & CD86) expression was assessed by flow cytometry. BCP induced metabolic changes were assessed by Seahorse analysis and glycolytic marker expression (hexokinase 2(HK2), Glut1 and HIF1α) was examined using real-time PCR and immunoblotting. RESULTS: Treatment with BCP crystals upregulated mRNA levels of CXCL9 and CXCL10 while concomitantly downregulating expression of CCL13 and MRC1. Furthermore, BCP-treated macrophages enhanced surface expression of the maturation makers, CD40, CD80 and CD86. BCP-treated cells also exhibited a shift towards glycolysis as evidenced by an increased ECAR/OCR ratio and enhanced expression of the glycolytic markers, HK2, Glut1 and HIF1α. Finally, BCP-induced macrophage activation and alarmin expression was reduced in the presence of the glycolytic inhibitor, 2-DG. CONCLUSIONS: This study not only provides further insight into how OA-associated DAMPs impact on immune cell function, but also highlights metabolic reprogramming as a potential therapeutic target for calcium crystal-related arthropathies.

Growth plate extracellular matrix-derived scaffolds for large bone defect healing.

Limitations associated with demineralised bone matrix and other grafting materials have motivated the development of alternative strategies to enhance the repair of large bone defects. The growth plate (GP) of developing limbs contain a plethora of growth factors and matrix cues which contribute to long bone growth, suggesting that biomaterials derived from its extracellular matrix (ECM) may be uniquely suited to promoting bone regeneration. The goal of this study was to generate porous scaffolds from decellularised GP ECM and to evaluate their ability to enhance host mediated bone regeneration following their implantation into critically-sized rat cranial defects. The scaffolds were first assessed by culturing with primary human macrophages, which demonstrated that decellularisation resulted in reduced IL-1ß and IL-8 production. In vitro, GP derived scaffolds were found capable of supporting osteogenesis of mesenchymal stem cells via either an intramembranous or an endochondral pathway, demonstrating the intrinsic osteoinductivity of the biomaterial. Furthermore, upon implantation into cranial defects, GP derived scaffolds were observed to accelerate vessel in-growth, mineralisation and de novo bone formation. These results support the use of decellularised GP ECM as a scaffold for large bone defect regeneration.

Intra-articular basic calcium phosphate and monosodium urate crystals inhibit anti-osteoclastogenic cytokine signalling.

OBJECTIVE: Basic calcium phosphate (BCP) and monosodium urate (MSU) crystals are particulates with potent pro-inflammatory effects, associated with osteoarthritis (OA) and gout, respectively. Bone erosion, due to increased osteoclastogenesis, is a hallmark of both arthropathies and results in severe joint destruction. The aim of this study was to investigate the effect of these endogenous particulates on anti-osteoclastogenic cytokine signalling. METHODS: Human osteoclast precursors (OcP) were treated with BCP and MSU crystals prior to stimulation with Interleukin (IL-6) or Interferon (IFN-γ) and the effect on Signal Transducer and Activator of Transcription (STAT)-3 and STAT-1 activation in addition to Mitogen Activated Protein Kinase (MAPK) activation was examined by immunoblotting. Crystal-induced suppressor of cytokine signalling (SOCS) protein and SH-2 containing tyrosine phosphatase (SHP) expression was assessed by real-time polymerase chain reaction (PCR) in the presence and absence of MAPK inhibitors. RESULTS: Pre-treatment with BCP or MSU crystals for 1 h inhibited IL-6-induced STAT-3 activation in human OcP, while pre-treatment for 3 h inhibited IFN-γ-induced STAT-1 activation. Both crystals activated p38 and extracellular signal-regulated (ERK) MAPKs with BCP crystals also activating c-Jun N-terminal kinase (JNK). Inhibition of p38 counteracted the inhibitory effect of BCP and MSU crystals and restored STAT-3 phosphorylation. In contrast, STAT-1 phosphorylation was not restored by MAPK inhibition. Finally, both crystals potently induced the expression of SOCS-3 in a MAPK dependent manner, while BCP crystals also induced expression of SHP-1 and SHP-2. CONCLUSION: This study provides further insight into the pathogenic effects of endogenous particulates in joint arthropathies and demonstrates how they may contribute to bone erosion via the inhibition of anti-osteoclastogenic cytokine signalling. Potential targets to overcome these effects include p38 MAPK, SOCS-3 and SHP phosphatases.

Meta-analysis of the prognostic significance of perinodal spread in head and neck squamous cell carcinomas (HNSCC) patients.

To assess the risk factor of capsular rupture for individual prognosis and potential therapeutic decision making, the present meta-analysis elaborated the prognostic significance of perinodal spread in a large group of patients suffering from head and neck squamous cell carcinomas (HNSCC). A review of the published literature was conducted, and fixed and random effects models were applied for estimation of the summarised odds ratio and 95% confidence intervals, including a test for homogeneity of the odds ratios. Study methodology allowed the enrollment of only nine studies of 115 published papers. Excluded studies lacked regarding primary tumour location, number and location of lymph node metastases, values on five-year survival, or adequate follow-up data. A summarised odds ratio of 2.7 leads to the conclusion that perinodal spread negatively impacts the five-year survival. The lower confidence limit of more than 2 also supports the concept that perinodal spread significantly reduces (doubled risk) the five-year-survival. These results support the conclusion that perinodal spread is a significant adverse risk factor for survival in patients with HNSCC.

Investigation of the medium-term effects of Olibratrade mark fat emulsion on food intake in non-obese subjects.

OBJECTIVE: To investigate the effect of Olibra fat emulsion on medium-term food intake and appetite in non-obese subjects. DESIGN: Double-blind, placebo-controlled, within-subject crossover. SETTING: University of Ulster, Coleraine. SUBJECTS: A total of 28 subjects (14 male, 14 female). INTERVENTIONS: Subjects were randomly assigned to receive either a 200 g portion of test (5 g of Olibra fat) or control (5 g milk fat) yoghurt for breakfast for 2 x 3 week 'study' phases, separated by a 3-week 'wash-out' phase. On days 1, 8 and 22 of the study phases, food intake 4 h post-consumption of the yoghurt was assessed by pre- and post-covert weighing at an ad libitum buffet-style test lunch. Throughout each of these study days, appetite was assessed using visual analogue scales (VAS) at regular intervals. For the remainder of the study days, and the following 24 h ('post-study days'), subjects reported their food intake using weighed dietary records. RESULTS: Consumption of the Olibra emulsion had no significant effect on mean energy, macronutrient or amounts of food consumed at the lunch 4 h post-consumption. Self-reported food intakes indicated that there was no significant effect of the emulsion on energy intakes for the remainder of each study day and post-study days. There was considerable individual variation in food intakes following consumption of the Olibra emulsion, with 46, 59 and 57% of subjects reducing their energy intakes at lunch on days 1, 8 and 22. There was no consistent effect of the emulsion on appetite ratings. CONCLUSIONS: In contrast to earlier studies, there was no evidence of a short- or medium-term effect of the Olibra emulsion on food intake or appetite. This could be owing to numerous confounding factors influencing eating behaviour and/or the different study design used in the present study.

Exploiting the lacZ reporter gene for quantitative analysis of disseminated tumor growth within the brain: use of the lacZ gene product as a tumor antigen, for evaluation of antigenic modulation, and to facilitate image analysis of tumor growth in situ.

We extend use of the lacZ reporter gene for tumor biology. Intracerebral growth of 9L/lacZ, a gliosarcoma cell line that stably expresses lacZ, was evaluated in syngeneic rats. The reporter gene product, Escherichia coli-derived beta-galactosidase (beta-gal), was detected histochemically on tissue sections. This permits visualization of disseminated tumor and, as shown here, facilitates image analysis. We show that the beta-gal marker protein itself can serve as a tumor antigen in appropriate contexts. Quantitative image analysis of tumor areas is used to show that immunization with beta-gal protects against tumor growth. Abnormal beta-gal- areas are easily detected, facilitating study of antigenic modulation. The tumor studied did not escape through this mechanism. All abnormal beta-gal- areas examined were shown to reflect accumulation of inflammatory or reactive cells, not tumor. Taken together, these findings show several ways in which the lacZ reporter gene can be exploited to facilitate quantitative analysis of disseminated tumor growth within the brain. They draw attention to the growing appreciation that tumor antigens need not be cell surface molecules.

Influence of matrix metalloproteinase 9 (MMP-9) on the metastatic behavior of oropharyngeal cancer.

BACKGROUND: The role of the single matrix metalloproteinases (MMPs) in the metastatic process of squamous cell carcinomas (SCC) is still obscure. MATERIALS AND METHODS: The MMP-9 expression was described immunohistochemically in 105 patients (40-79 years of age, mean: 57.84 years; 84 male, 21 female) suffering from orophatyngeal cancer (22x TI, 31x T2, 24x T3, 28x T4) with different neck stages (41x N0, 6x N1, 54x N2, 4x N3 neck). RESULTS: A significant correlation between MMP-9 expression and T stage (p < 0.05), N stage (r = 0.55, p < 0.01) and UICC stage (r = 0.55, p < 0.01) was revealed. Most remarkable was the high MMP-9 expression with simultaneously high UICC stages. CONCLUSION: The results give further indication that MMP-9 plays a role in the metastatic behavior of oropharyngeal SCC. It will be a project for the near future to create a standardized evaluation score of immuno-histological stainings to allow valid comparison of the results and published data.

HIV replication in chronically infected macrophages is not inhibited by the Tat inhibitors Ro-5-3335 and Ro-24-7429.

Human immunodeficiency virus infects different cell types including CD4+ lymphocytes and monocyte-derived macrophages (MDMs). We have examined the activity of the HIV-1 Tat inhibitors Ro-5-3335 and Ro-24-7429 in cultured human peripheral MDMs. Monocytes were isolated from HIV-seronegative donors by gradient centrifugation and plastic adherence. MDMs and unfractionated peripheral blood mononuclear cells (PBMCs) were infected with HIV Ba-L and then treated with drug either immediately (acute infection) or after 4 days (PBMCs) or 14 days (MDMs) (chronic infection). Inhibition of HIV replication by each drug was assessed by quantitation of HIV p24 antigen in culture supernatant using an enzyme immunoassay. In acutely infected MDMs, Ro-5-3335 (10 microM) and Ro-24-7429 (10 microM) resulted in 77% and 99% mean inhibition, respectively, of HIV replication with a clear dose response at lower concentrations; chronically infected MDMs were much less susceptible to these drugs, with both compounds inhibiting p24 antigen production by less than 50% at 10 microM. The drugs had no deleterious effect on cell viability at any concentration tested. In acutely infected PBMCs Ro-5-3335 and Ro-24-7429 resulted in 68% and 68.5% mean inhibition at 10 microM; when the compounds were added 4 days after infection inhibition was less than 50% compared with controls. Thus, the Tat inhibitors were effective in inhibiting acute HIV infection in MDMs but not in chronically infected cells, findings that differ from those of published studies using continuous lymphoblastoid cell lines.

RT-PCR expression profiling of matrix metalloproteinases and their specific inhibitors in cell lines and fresh biopsies of squamous cell carcinomas of the head and neck.

The expressions of MMP2, -7, -9, -13 and TIMP1, -2, -3 were examined in biopsies and cell lines of head and neck squamous cell carcinomas (HNSCC) to determine the association between the expression profile and TNM-staging of the primary. The expressions of MMP2, -7, -9, -13 and TIMP1, -2, -3 were analyzed in 30 HNSCC biopsies, 7 HNSCC cell lines and 1 keratinocyte cell line using RT-PCR. Negative correlation was determined between N-status and MMP13-RNA expression [Kendall-tau-b -0.404 (p = 0.016), Spearman-rho -0.448 (p = 0.014)], histological grading [Kendall-tau-b -0.291 (p = 0.049), Spearman-rho -0,333 (p = 0.048)], and MMP7 and TIMP2 expression [Kendall-tau-b -0.318 (p = 0.045); Spearman-rho -0.353 (p = 0.045)]. Positive correlation was determined between M-status and MMP9-RNA expression [Kendall-tau-b 0.341 (p = 0.025), Spearman-rho 0.377 (p = 0.024)] and MMP13 and TIMP2 expression [Kendall-tau-b 0.727 (p = 0.037), Spearman-rho 0.850 (p = 0.016)]. The results point to a role of the tested MMPs and TIMPs in the metastatic spread of HNSCC.

Bipolar radiofrequency induced thermotherapeutic volumetric reduction of VX2 metastases in an animal model.

BACKGROUND: Radiofrequency-induced thermotherapy has shown promising results in the palliative treatment of various tumor entities. The purpose of this study was to investigate the effectiveness of bipolar radiofrequency volumetric tissue reduction (VTR) on lymph node (LN) metastases in the VX2 SCC model. MATERIALS AND METHODS: Six male New Zealand white rabbits, with palpable metastatic disease within the parotid lymph nodes, were treated using the Celon-ProSurge probe, needle length 10 mm, diameter of 2.3 mm. The animals were sacrificed on the 4th, 8th, 11th, 14th, 18th and 22nd postoperative days respectively. RESULTS AND CONCLUSION: Bipolar radiofrequency VTR could prevent progression of local metastatic disease in one-third of the animals compared to the control group of untreated VX2 carcinoma rabbits. These results encourage further studies, directed at whether this treatment modality could play a role in the palliative therapy of metastatic LN. Future studies should concentrate on the refinement of the treatment parameters and optimization of the treatment duration.

Intraoperative lymphatic mapping in cases of midline squamous cell carcinoma.

OBJECTIVE: To analyze the value of intraoperative lymphatic mapping in cases of midline primary head and neck squamous cell carcinoma (HNSCC) in clinically staged N0 necks. MATERIAL AND METHODS: Eleven patients with HNSCC of the epiglottis (2 T1, 6 T2, 3 T3), all of whom were staged with a neck status of N0 using sonography and CT, underwent intraoperative peritumoral (99m)Tc-nanocoll injection (4 sites; 45 MBq), radiolabeled detection and analysis of up to 3 hot sentinel nodes (SNs) during elective neck dissection. RESULTS: Gamma probe use revealed bi- and unilateral intranodal tracer uptake in 6/11 and 5/11 patients, respectively. In 2/6 patients with bilateral intranodal tracer uptake an SN with an isolated metastasis was found at one neck site while the other four patients were tumor-free in the SNs. Of the five patients with unilateral intranodal tracer uptake, three had radiolabeled SNs containing isolated metastases whereas two had no cancer detected, giving a total occult cancer rate of 45% (5/11). No cancer was found in non-labeled nodes. CONCLUSIONS: Intraoperative lymphatic mapping correctly identified the stage of metastatic disease. Unilateral tracer uptake represented the pathway of occult metastatic spread in 3/5 patients and the disease-free neck status of both neck sites in 2/5 patients. No patient had occult bilateral cancer. Future investigations should be done to determine whether intraoperative lymphoscintigraphy can guide the indication for unilateral only or bilateral neck dissection in these patients.

A novel TLR2 agonist from Bordetella pertussis is a potent adjuvant that promotes protective immunity with an acellular pertussis vaccine.

Bordetella pertussis causes whooping cough, a severe and often lethal respiratory infection in infants. A recent resurgence of pertussis has been linked with waning or suboptimal immunity induced with acellular pertussis vaccines (Pa) that were introduced to most developed countries in the 1990s because of safety concerns around the use of whole-cell pertussis vaccines (Pw). Pa are composed of individual B. pertussis antigens absorbed to alum and promote strong antibody, T helper type 2 (Th2) and Th17 responses, but are less effective at inducing cellular immunity mediated by Th1 cells. In contrast, Pw, which include endogenous Toll-like receptor (TLR) agonists, induce Th1 as well as Th17 responses. Here we report the identification and characterization of novel TLR2-activating lipoproteins from B. pertussis. These proteins contain a characteristic N-terminal signal peptide that is unique to Gram-negative bacteria and we demonstrate that one of these lipoproteins, BP1569, activates murine dendritic cells and macrophages and human mononuclear cells via TLR2. Furthermore, we demonstrated that a corresponding synthetic lipopeptide LP1569 has potent immunostimulatory and adjuvant properties, capable of enhancing Th1, Th17, and IgG2a antibody responses induced in mice with an experimental Pa that conferred superior protection against B. pertussis infection than an equivalent vaccine formulated with alum.

Monocytes harbour replication-competent, non-latent HIV-1 in patients on highly active antiretroviral therapy.

OBJECTIVE: To determine whether HIV-1 can be recovered from blood monocytes as well as resting, memory CD4 T lymphocytes of patients on highly active antiretroviral therapy (HAART) with undetectable plasma viraemia and whether infection is active or latent. DESIGN: Five patients with plasma HIV-1-RNA levels of less than 500 copies/ml for at least 3 months and less than 50 copies/ml at the time of sampling were initially selected, followed by an additional five patients with viral loads of less than 50 copies/ml for 3 months or more. METHODS: Monocytes were isolated from blood by plastic adherence, then further purified by a second adherence step or CD3 depletion before co-culture with CD8-depleted donor peripheral blood mononuclear cells. Virus isolates were examined for mutations conferring resistance to reverse transcriptase or protease inhibitors and for genotype. The highly purified monocytes were also analysed for the presence of proviral and unintegrated viral DNA and multiply spliced (MS) viral mRNA by polymerase chain reaction. RESULTS: Virus was recovered from monocytes of five patients. Sequencing of the recovered viruses did not reveal multiple drug resistance, and was consistent with a non-syncytium-inducing/CCR5 phenotype. Proviral DNA was detectable in monocytes from all subjects, and unintegrated HIV-1 DNA and MS RNA was found in four out of five populations examined. CONCLUSION: Recovery of replication-competent virus from some HAART patients indicates that monocytes can also harbour HIV-1. Detection of circular, viral DNA and spliced RNA, albeit at very low levels, in these cells suggests that their infection is recent and transcriptionally active rather than latent.

Comparison of genotyping and phenotyping methods for determining susceptibility of HIV-1 to antiretroviral drugs.

OBJECTIVE(S): To compare antiretroviral resistance susceptibility testing of patient HIV-1 strains using genotype and phenotype methods. DESIGN: Eighteen plasma samples with viral load > 2000 HIV-1 RNA copies/ml were randomly selected for testing by both methods. Disease and treatment data were available for all patients. METHODS: Samples were analysed genotypically using a kit assay (HIV-1 Genotyping Systems, Applied Biosystems), performed by the Clinical Research Laboratory at Macfarlane Burnet Centre for Medical Research. Samples were analysed phenotypically using a rapid phenotypic assay (PhenoSenseTM HIV, ViroLogic), performed by the manufacturer. Results from both methods were interpreted using a defined protocol. Each susceptibility assay was performed and interpreted by individuals unaware of either the clinical data or the results of the other susceptibility assay. Concordance was defined categorically as either the presence of reduced susceptibility (> 2.5-fold change) in the phenotypic assay and resistance associated mutations in the genotypic assay, or the absence of these findings in both assays. RESULTS: Concordance between phenotypic and genotypic susceptibility testing was 81% for nucleoside reverse transcriptase inhibitors, 91% for non-nucleoside reverse transcriptase inhibitors and 90% for protease inhibitors. Complete concordance between phenotype and genotype for all 14 drugs evaluated was observed in three (17%) patient samples. CONCLUSIONS: Phenotypic and genotypic susceptibility appear to provide similar results. However, interpretation of genotypic results can be complicated, and both methods still require clinical validation.

Double-blind randomized clinical trial of self-administered podofilox solution versus vehicle in the treatment of genital warts.

PURPOSE: Genital warts are a highly prevalent and chronic sexually transmitted disease for which there is no completely satisfactory therapy. Conventional ablative therapy requires repeated treatment, often for months or years. This study was undertaken to evaluate the safety and efficacy of 0.5% podofilox in patient-administered treatment of penile warts. PATIENTS AND METHODS: Thirty-eight men with penile warts were randomly assigned to double-blind, self-administration of 0.5% podofilox solution or placebo, twice daily for 3 days per week for 4 weeks. Eleven podofilox and 15 placebo recipients with residual warts then received an additional 4 weeks of open-label treatment. RESULTS: By the end of treatment, podofilox recipients had their mean wart number and area reduced to 15.9% and 5.1% of baseline values, compared to 97.4% and 92.9% in the placebo group (p = 0.0001). Local adverse reactions were more common in the podofilox group, but were transient. Complete disappearance of warts was observed in 25 (53.3%) of 45 treatment courses, including open-label treatment. Recurrences of warts after therapy were frequent. Only 21% of patients remained free of warts 2 weeks after completing treatment, and subsequent recurrences were noted in all patients available for long-term follow-up, which is a common limitation of ablative therapy for genital warts. CONCLUSION: Podofilox 0.5% solution is effective in treating penile warts and is well tolerated in a self-administered regimen. Podofilox 0.5% offers potential advantages in safety and cost over podophyllin resin therapy of genital warts.

Sodium valproate stimulates the particulate form of glutamine synthetase in rat brain.

The anticonvulsant drug, sodium valproate, enhanced total activity of glutamine synthetase in cortical and cerebellar homogenates of the rat at concentrations of 25-50 mM, without significantly altering substrate affinity. This effect was due to a selective increase in the Vmax and substrate affinity of the enzyme in the particulate fraction. At the same concentration the drug caused little change in the Vmax of the cytosolic enzyme, although the substrate affinity was reduced. These effects cannot be attributed to isozymes of glutamine synthetase as only one form could be demonstrated by ion-exchange chromatography or electroblotting with antibodies to glutamine synthetase. This selective stimulation of particulate glutamine synthetase is suggested to be due to increases in membrane fluidity induced by the drug. The contribution of these effects to the mechanistic action of sodium valproate is discussed.

Enzymatic removal of alpha-galactosyl epitopes from porcine endothelial cells diminishes the cytotoxic effect of natural antibodies.

Xenotransplantation of tissues between discordant species such as pig into human is not yet feasible due to the problem of hyperacute rejection. This rapid response to xenogeneic tissue is mediated by natural antibodies that react with antigens on the xenograft. A number of xenoantigens consist of carbohydrate residues, and a terminal galactose in alpha linkage has been shown to be involved in hyperacute rejection of pig-to-human xenografts. We show that alpha-linked galactose on porcine endothelial cells is a major epitope recognized by IgG and IgM antibodies present in monkey and human sera. Endothelial cells that had been treated with alpha-galactosidase did not react with fluorescein-labeled Griffonia simplicifolia I B4 (GS-IB4), a lectin that detects the alpha-galactosyl epitope on intact cells. The reactivity of both human and cynomolgus monkey serum with endothelial cells was decreased by 59% to 90% after treatment with coffee bean alpha-galactosidase. Using a colorimetric assay for cell viability, we show that natural antibodies present in the sera of cynomolgus monkey and humans are cytotoxic to porcine endothelial cells in the presence of exogenously added complement. When the terminal alpha-galactosy residues were removed by enzymatic digestion, the cytotoxic effect of natural antibodies on porcine endothelial cells was diminished by > 80%. Evaluation of the time course of reappearance of the alpha-galactosyl epitope at the cell surface revealed that 48 hr after alpha-galactosidase treatment, binding of GS-IB4 was diminished by 60%. These results suggest that glycosidase treatment of cells to be transplanted could prevent hyperacute rejection mediated by natural antibodies.

Does plasma HIV RNA predict outcome in a cohort of treated HIV-infected individuals followed over 3 years?

BACKGROUND: Despite reductions in AIDS illness and mortality, it is increasingly apparent that a significant proportion of individuals treated with combination antiretroviral (cARV) therapy have continuing or recrudescent HIV RNA in plasma. The predictive value of plasma HIV RNA in treated individual remains uncertain and rates of and risk factors for adverse outcomes such as hospitalisation, opportunistic infections and deaths are needed. OBJECTIVES: The objectives of this study were to establish a retrospective cohort of individuals treated with cARVs, to assess factors associated with detectable HIV RNA and to determine rates of and risk factors for hospitalisation, opportunistic infection and mortality over 3 years of follow-up. STUDY DESIGN: All individuals treated at The Alfred Hospital, Melbourne, Victoria between January and June 1997 who had had plasma HIV RNA measured were included in the retrospective cohort. Clinical, virological and hospitalisation data were recorded and validated by cross-reference with electronically stored laboratory, hospital activity and state notification databases. Outcome was assessed at October 2000. RESULTS: Amongst the 555 individuals tested, 438 (60.7%) had detectable (>500 copies/ml) HIV RNA (bDNA assay, version 2) at baseline. The overall mortality rate was 5.5 per 100 person years; the AIDS rate 1.99 per 100 person years and hospitalisation rate 16.4 per 100 person years. Risk factors for death in this population identified by univariate analysis were HIV RNA concentration at baseline and at follow-up October 2000, nadir and most recent CD4 lymphocyte number, not receiving cARV as initial treatment, total number of ARV agents and number of changes in ARV per year, developing AIDS and being hospitalised during follow-up. In a multivariate model, the most recent CD4 lymphocyte number, the number of different ARVs per year and having more than one hospitalisation remained predictive of death. CONCLUSIONS: HIV RNA remained detectable in the majority (60.7%) of this treatment-experienced population over 3 years, yet mortality rate remained relatively low at 5.5 per 100 person years. Factors associated with death were immunological (CD4 lymphocyte number) and treatment related (numbers of changes of ARV and hospitalisation) rather than virological (HIV RNA) in this cohort. We believe hospitalisation rates may be a useful marker of HIV disease in cARV treated populations and may identify groups at risk of poorer outcome and in need of intervention.