Myeloid cell-derived proteases produce a proinflammatory form of IL-37 that signals via IL-36 receptor engagement

Interleukin-1 (IL-1) family cytokines are key barrier cytokines that are typically expressed as inactive, or partially active, precursors that require proteolysis within their amino termini for activation. IL-37 is an enigmatic member of the IL-1 family that has been proposed to be activated by caspase-1 and to exert anti-inflammatory activity through engagement of the IL-18R and SIGIRR. However, here we show that the longest IL-37 isoform, IL-37b, exhibits robust proinflammatory activity upon amino-terminal proteolysis by neutrophil elastase or cathepsin S. In sharp contrast, caspase-1 failed to process or activate IL-37 at concentrations that robustly activated its canonical substrate, IL-1β. IL-37 and IL-36 exhibit high structural homology, and, consistent with this, a K53-truncated form of IL-37, mimicking the cathepsin S-processed form of this cytokine, was found to exert its proinflammatory effects via IL-36 receptor engagement and produced an inflammatory signature practically identical to IL-36. Administration of K53-truncated IL-37b intraperitoneally into wild-type mice also elicited an inflammatory response that was attenuated in IL-36R^-/- animals. These data demonstrate that, in common with other IL-1 family members, mature IL-37 can also elicit proinflammatory effects upon processing by specific proteases.

POS0443 INSIDE THE JOINT OF INFLAMMATORY ARTHRITIS PATIENTS: HANDLING AND PROCESSING OF SYNOVIAL TISSUE BIOPSIES FOR HIGH THROUGHPUT ANALYSIS

Background

Inflammatory arthritis (IA) is a chronic systemic autoimmune disease of unknown aetiology, which affects the joints. While studies of immune cell populations in peripheral blood have been informative regarding potential immune cell dysfunction and possible patient stratification, there are considerable limitations in identifying the early events that lead to synovial inflammation. The joint, as the site of inflammation and the local microenvironment, exhibit unique characteristics that contribute to disease pathogenesis. The limited availability of synovial tissue (ST) biopsies is a key incentive for the utilisation of high-throughput techniques in order to maximise information gain.

Objectives

This work aims to provide an overview of key methods and novel techniques that are used in the handling, processing and analysis of ST biopsies and the potential synergy between these techniques.

Methods

We describe the utilisation of high dimensionality flow cytometric analysis, single cell RNA sequencing, ex vivo functional assays, including T cell activation, endocytosis and two-photon fluorescent lifetime imaging microscopy (FLIM).

Results

When comparing different methods for ST cell suspension generation we observed that the combination of mechanical and enzymatic digestion resulted in the release of considerably higher numbers of total viable cells when compared to mechanical digestion alone, although consideration should be taken in the cleaving of extracellular markers, like CD27. We next compared two different cryopreservation methods to that of freshly digested ST and observed similar viability and frequency of immune cells. Functional characterisation of ST cells can be challenging due to the high number of cells required for analysis, herein, we utilised the above protocols to establish ST viable cell suspensions and optimised different experimental approaches for phenotypical/functional characterisation. To investigate the functional consequence of OxPhos inhibition on ST T-cell polyfunctionality, ex-vivo ST cell suspensions from IA patients were stimulated with PMA/Ionomycin in the presence/absence of FCPP followed by metabolic profile characterisation via FLIM and high dimensionality flow-cytometric analysis for T cell-derived cytokines. Treatment with FCPP resulted in a decreased in T-cell polyfunctionality specifically in co-expression of TNF-α,-IL-2,-IFN-γ,IL-17A, -GM-CSF, an effect associated with a shift in their metabolic profile. In addition, freshly digested ST cell suspensions were subjected to an optimized assay to evaluate endocytosis in multiple populations simultaneously without the need for cell sorting. Briefly, digested cells were incubated in parallel at 4°C (passive endocytosis) and 37°C (active endocytosis) with DQ OVA(Ovalbumin). ST cells were then stained for multiple populations, demonstrating differential endocytosis capacity across pathotypes and disease controls.

Finally, utilisation of novel bioinformatics analysis of RNAseq a data showed differential gene expression and pathway enrichment involved in IA pathogenesis and allowed for the comparison of cell specific enrichment scores and transcription factor usage based on pathotype and gender.

Conclusion

The introduction of new powerful techniques in the study of ST inflammation, brings new challenges and significant opportunities. These approaches will accelerate our path towards understanding of the mechanisms involved in the pathogenesis of IA and lead to the identification of new avenues of therapeutic intervention.

Acknowledgements

We would like to thank all the patients who consented to be involved in this study.

Disclosure of Interests

None declared.

AB0903 Dual Immunomodulatory Therapies in Psoriatic Disease

Background

Since the advent of numerous biologic therapies and small molecular drugs targeting specific cytokines and signalling pathways; the management of patients with psoriatic arthritis (PsA) has significantly improved. However, at least 40% of PsA patients exhibit an incomplete or failure to respond to these treatments.

While the outcomes of patients with psoriasis (Pso) has dramatically improved with monoclonal antibody therapies targeting IL-23 and IL-17A; achieving a measurable low disease activity state such as minimal disease activity (MDA) for musculoskeletal manifestations of psoriatic disease is infrequent. Given the complex and heterogeneity of signalling pathways, cytokines and cell types resulting in synovio-entheseal disease in PsA; new treatment strategies must be evaluated to induce deep and sustainable clinical responses in all the phenotypic domains of psoriatic disease (cutaneous, synovium, entheseal and axial). (1)

In patients who do not achieve remission in all clinical domains on a biologic monotherapy or combination of a biologic therapy with an oral synthetic agent; dual targeted anti-cytokines strategies or combined biologic with a targeted oral small molecule are a possible treatment option.

Objectives

To describe a series of four patients with recalcitrant psoriatic disease and failure to respond to previous treatment regimens who were successfully treated with dual immunomodulatory therapies.

Methods

Patients on dual immunomodulatory therapies attending our department were prospectively followed and clinical response monitored.

Results:

Table 1.Age/genderDiagnosisprior therapiescombination therapydoseadverse eventsCase 149/ MalePsA + PsOMethotrexate, adalimumab, etanercept, infliximab, golimumab, certolizumab, ustekinumab, secukinumab, ixekizumabBaracitinib + infliximab4mg OD + 5mg/kg Q8WNoneCase 251/ MalePsA + PsOMethotrexate, etanercept, adalimumab, ustekinumab, infliximab, secukinumab, apremilast, ixekizumab, brodalumab, guselkumabAdalimumab + guselkumab40mg QoW +100mg Q8WNoneCase 351/ FemalePsA + PsOMethotrexate, sulphasalazine, etarnercept, certolizumab, leflunomide, infliximab, adalimumab, secukinumab, ustekinumab, tofacitinib, abatacept, baracitinibAdalimumab + tofacinitib40mg QoW + 5mg BDNoneCase 439/ MalePsA +PsOMethotrexate, etanercept, ustekinumab, adalimumab, secukinumab, ixekizumab, sulphasalazineIxekizumab + baracitinib80mg Q4W+ 4mg ODNoneFigure 1.

Mini-Arthroscopy of left knee for Case 3 prior to starting dual immunomodulator therapy.

(A) Macroscopic aspects of synovitis (B) Synovium vascularization

Conclusion

Multiple pathways and mediators are responsible for the initiation of and sustained joint inflammation and damage seen in PsA. A phase II trial of ABT-122, a biologic engineered to target both TNF and IL-17A showed statistically significant superior efficacy outcomes at multiple time points based on ACR50, ACR70 and psoriasis outcome measures (PASI75/PASI90) when compared to adalimumab, with similar safety profile.(2)

Safety concerns such as infectious risks are important considerations with such strategies; however, the targeted second-generation anti-cytokine biologics and targeted JAK-I have exhibited improved safety profiles.(3) In our small case series, patients have not, to date, experienced adverse events of combination therapy.

References

[1]Haberman RH, Castillo R, Scher JU. Induction of remission in biologic-naive, severe psoriasis and PsA with dual anti-cytokine combination. Rheumatology. 2021;60(7):e225-e6.

[2]Mease PJ, Genovese MC, Weinblatt ME, Peloso PM, Chen K, Othman AA, et al. Phase II Study of ABT-122, a Tumor Necrosis Factor– and Interleukin-17A–Targeted Dual Variable Domain Immunoglobulin, in Patients With Psoriatic Arthritis With an Inadequate Response to Methotrexate. Arthritis & Rheumatology. 2018;70(11):1778-89.

[3]Scher JU, Ogdie A, Merola JF, Ritchlin C. Moving the Goalpost Toward Remission: The Case for Combination Immunomodulatory Therapies in Psoriatic Arthritis. Arthritis & Rheumatology. 2021;73(9):1574-8.

Disclosure of Interests

None declared

POS0462 ALCOHOL AND INFLAMMATORY ARTHRITIS DISEASE ACTIVITY: PERSPECTIVES FROM A 979-PATIENT COHORT WITH SYSTEMATIC REVIEW AND META-ANALYSIS

Background:

The effect of alcohol on disease activity in inflammatory arthritis remains poorly understood. Studies of alcohol and the incidence or risk of inflammatory arthritis are conflicting [1,2]. Alcohol does downregulate pro-inflammatory cytokines and may therefore reduce immune-mediated disease activity.

Objectives:

This study investigates the relationship between alcohol consumption and disease activity in our inflammatory arthritis patient cohort and performs a systematic review with meta-analysis.

Methods:

Cohort Study Design and data analysis

Patients attending a rheumatology clinic between 2010-2020 were prospectively followed. Information on demographics, alcohol use, smoking habits, and disease outcome measures were collected. Statistical analysis included univariate and multivariate linear and binary logistic regressions, Mann Whitney-U tests, and one-way ANOVA with Tukey’s HSD.

Meta-analysis

EMBASE, Pubmed, the Cochrane library, and Web of Science were searched. Studies reporting on alcohol consumption and disease activity in a cohort of RA patients were included for further investigation. Forest plots were generated from 95% confidence intervals of extracted data using mean differences. Linear regression was used to determine correlations between alcohol and antibody status, gender, and smoking status.

Results:

Cohort Study

Of the 979 analysed patients, 62% had RA, 26.7% had PsA, and 11.2% had AS. Mean DAS28-CRP in RA and PsA at one year was 2.96 ± 1.39, and 64.2% of patients were in remission (DAS28-CRP ≤ 2.6 or BASDAI ≤ 4). Both male gender and risky drinking (>15 units of weekly alcohol) were both significantly associated with remission. Compared to women, men had an odds ratio of 1.78 [1.04, 2.52] (p=0.034) for any alcohol consumption and 6.9 [4.7, 9.1] (p=0.001) for drinking at least 15 weekly drinks. when adjusted for gender, there was no significant association between alcohol and disease activity. Yet, when adjusted for alcohol consumption, gender still influenced disease activity.

Meta-analysis

The search identified 4126 citations of which 14 were included. The pooled mean difference in DAS28 (95% CI) was 0.34 (0.24,0.44) (p<10-5) between non-drinkers and drinkers, 0.33 (0.05,0.62) (p=0.02) between non-drinkers and heavy drinkers, and 0 (-0.3,0.3) (p=0.98). between low- and high-risk drinkers. There was a significant difference in the mean difference of HAQ assessments between those who drink alcohol compared to those who do not (0.3 (0.18,0.41), p<10-5). There was no significant correlation between drinking and gender, smoking status, or antibody positivity.

Conclusion:

While it appears that alcohol is linked to remission in inflammatory arthritis, this association is lost when adjusted for gender. Men with inflammatory arthritis drink significantly more than women and men generally have less severe disease activity. However, the meta-analysis suggests alcohol consumption is associated with lower disease activity and self-reported health assessment in rheumatoid arthritis.

References:

[1]Bae S-C, Lee YH. Alcohol intake and risk of rheumatoid arthritis: a Mendelian randomization study. Z Rheumatol 2019;78:791–6. doi:10.1007/s00393-018-0537-z

[2]Scott IC, Tan R, Stahl D, et al. The protective effect of alcohol on developing rheumatoid arthritis: a systematic review and meta-analysis. Rheumatology (Oxford) 2013;52:856–67. doi:10.1093/rheumatology/kes376

Figure 1.

Mean differences in DAS28 between drinking groups. A between non-drinkers and drinkers. B between non-drinkers and high-risk drinkers. C between low-risk and high-risk drinkers.

Disclosure of Interests:

None declared

Mycobacterial para-Hydroxybenzoic Acid-Derivatives (pHBADs) and Related Structures Induce Macrophage Innate Memory

Macrophages are key immune cells for combatting Mycobacterium tuberculosis. However, M. tuberculosis possesses means to evade macrophage bactericidal responses by, for instance, secretion of the immunomodulatory para-hydroxybenzoic acid derivatives (pHBADs). While these molecules have been implicated in inhibiting macrophage responses in an acute context, little is known about their ability to reprogram macrophages via induction of long-term innate memory. Since innate memory has been highlighted as a promising strategy to augment bactericidal immune responses against M. tuberculosis, investigating corresponding immune evasion mechanisms is highly relevant. Our results reveal for the first time that pHBAD I and related molecules (unmethylated pHBAD I and the hexose l-rhamnose) reduce macrophage bactericidal mechanisms in both the short- and the long-term. Moreover, we demonstrate how methyl-p-anisate hinders bactericidal responses soon after exposure yet results in enhanced pro-inflammatory responses in the long-term. This work highlights new roles for these compounds in M. tuberculosis pathogenesis.

The interrelationship between sex skin swelling and the urinary excretion of LH, estrone, and pregnanediol by the cycling female chimpanzee

The interrelationship between sex skin swelling and the urinary excretion of luteinizing hormone and sex steroids was investigated during ovulatory menstrual cycles in adult female chimpanzees. Estrone was excreted in two peaks, one during the preovulatory and the other during the midluteal phase. Maximum swelling of the sex skin was attained several days before the preovulatory estrone peak. The LH surge preceded or accompanied beginning detumescence of the sex skin which, in turn, was closely correlated with a rising excretion of pregnanediol. Urinary measurements provide integrated estimates of the concentration of fluctuating hormones and, in addition, are safer and easier to make than blood measurements in this species.

Changes in body weight and adiposity predict periodontitis progression in men

Most studies linking obesity and periodontal disease have been cross-sectional in design. We examined whether gains in body weight, waist circumference, and arm fat area are associated with periodontitis progression in 893 non-diabetic men followed for up to four decades in the prospective VA Dental Longitudinal Study. Probing pocket depth (PPD) was measured by calibrated examiners. Repeated-measures generalized linear models estimated the mean cumulative numbers of teeth with PPD events (PPD > 3 mm) at each dental examination and the slopes associated with increasing numbers of affected teeth over time. Means were adjusted for baseline PPD, education, and cigarette pack-years, and time-dependent values of age, mean plaque score, cigarette packs/day, brushing, and flossing. Men who were overweight at baseline and gained weight most rapidly (> 0.19 kg/yr or ~15 lb during follow-up) had significantly more PPD events than men in the lowest tertile of weight gain (≤ -0.05 kg/yr). Overweight men whose waist circumference increased > 0.14-0.39 or > 0.39 cm/yr experienced more PPD events than men in the lowest tertile (≤ 0.14 cm/yr). Increase in arm fat area was associated with disease progression in normal-weight men. These results suggest that tracking adiposity changes with easily obtained anthropometric measures may help predict risk of periodontitis progression.

A potent nonporphyrin class of photodynamic therapeutic agent: cellular localisation, cytotoxic potential and influence of hypoxia

We have developed a totally new class of nonporphyrin photodynamic therapeutic agents with a specific focus on two lead candidates azadipyrromethene (ADPM)01 and ADPM06. Confocal laser scanning microscopy imaging showed that these compounds are exclusively localised to the cytosolic compartment, with specific accumulation in the endoplasmic reticulum and to a lesser extent in the mitochondria. Light-induced toxicity assays, carried out over a broad range of human tumour cell lines, displayed EC₅₀ values in the micro-molar range for ADPM01 and nano-molar range for ADPM06, with no discernable activity bias for a specific cell type. Strikingly, the more active agent, ADPM06, even retained significant activity under hypoxic conditions. Both photosensitisers showed low to nondeterminable dark toxicity. Flow cytometric analysis revealed that ADPM01 and ADPM06 were highly effective at inducing apoptosis as a mode of cell death. The photophysical and biological characteristics of these PDT agents suggest that they have potential for the development of new anticancer therapeutics.

In Vitro Demonstration of the Heavy-Atom Effect for Photodynamic Therapy

Photodynamic therapy (PDT) is an emerging treatment modality for a range of disease classes, both cancerous and noncancerous. This has brought about an active pursuit of new PDT agents that can be optimized for the unique set of photophysical characteristics that are required for a successful clinical agent. We now describe a totally new class of PDT agent, the BF2-chelated 3,5-diaryl-1H-pyrrol-2-yl-3,5-diarylpyrrol-2-ylideneamines (tetraarylazadipyrromethenes). Optimized synthetic procedures have been developed to facilitate the generation of an array of specifically substituted derivatives to demonstrate how control of key therapeutic parameters such as wavelength of maximum absorbance and singlet-oxygen generation can be achieved. Photosensitizer absorption maxima can be varied within the body's therapeutic window between 650 and 700 nm, with high extinction coefficients ranging from 75,000 to 85,000 M(-1) cm(-1). Photosensitizer singlet-oxygen generation level was modulated by the exploitation of the heavy-atom effect. An array of photosensitizers with and without bromine atom substituents gave rise to a series of compounds with varying singlet-oxygen generation profiles. X-ray structural evidence indicates that the substitution of the bromine atoms has not caused a planarity distortion of the photosensitizer. Comparative singlet-oxygen production levels of each photosensitizer versus two standards demonstrated a modulating effect on singlet-oxygen generation depending upon substituent patterns about the photosensitizer. Confocal laser scanning microscopy imaging of 18a in HeLa cervical carcinoma cells proved that the photosensitizer was exclusively localized to the cellular cytoplasm. In vitro light-induced toxicity assays in HeLa cervical carcinoma and MRC5-SV40 transformed fibroblast cancer cell lines confirmed that the heavy-atom effect is viable in a live cellular system and that it can be exploited to modulate assay efficacy. Direct comparison of the efficacy of the photosensitizers 18b and 19b, which only differ in molecular structure by the presence of two bromine atoms, illustrated an increase in efficacy of more than a 1000-fold in both cell lines. All photosensitizers have very low to nondeterminable dark toxicity in our assay system.

The contribution of transfusion to HCV infection in England

The English HCV lookback programme has identified some individuals with transfusion-transmitted HCV infection. The path from the collection of donations from HCV-infected donors to the identification of infected recipients was constructed. The probability of different outcomes at each branch was derived from data collected during this programme. This path of probabilities was then used to produce a complete estimate of the number of recipients infected by blood transfusions (dead and alive at the end of 1995) by re-entry of blood components that fell out of the lookback at various steps prior to recipient testing, and entry of components from HCV-infected donations that were never identified for lookback. Less than 14,000 recipients were estimated to have been infected with HCV during the decade prior to the start of donation testing. Over 60% of these were expected to have died by the end of 1995. Transfusion has infected a large group of individuals. However, this group constitutes a very small, and declining, proportion of all HCV infections in the population.

Role of peroxide and superoxide anion during tumour cell apoptosis

Apoptosis or programmed cell death was induced in the human promyelocytic leukemia cell line HL-60 by UV irradiation or treatment with cytotoxic drugs (etoposide, camptothecin, melphalan or chlorambucil). These treatments caused a rapid increase in intracellular peroxide levels. Preincubation of HL-60 cells with the hydrogen peroxide-scavenging enzyme catalase (500 U/ml) inhibited apoptosis due to UV irradiation or low concentrations of camptothecin, etoposide or melphalan, but did not protect against higher concentrations. In contrast, superoxide anion levels in the cells remained unchanged upon treatment with cytotoxic drugs, while UV irradiation led to a transient doubling in superoxide levels. Exogenous superoxide dismutase (400 U/ml) provided modest protection against UV irradiation and had no effect on cytotoxic drug-induced apoptosis. The results suggest that both hydrogen peroxide and superoxide anion may be involved in the induction of apoptosis by UV irradiation. On the other hand, while exposure to cytotoxic drugs induces a large increase in intracellular peroxide levels, catalase is able to protect the cells from apoptosis only when low concentrations of these compounds are used, thus indicating the involvement of other factors in this process, particularly at higher drug concentrations.

Sulphur-containing excitatory amino acid-stimulated inositol phosphate formation in primary cultures of cerebellar granule cells is mediated predominantly by N-methyl-D-aspartate receptors

The stimulatory effect of excitatory sulphur-containing amino acids on inositol phosphate formation was investigated in primary cultures of cerebellar granule cells. L-Cysteine sulphinate (CSA), L-cysteate (CA), L-homocysteine sulphinate (HCSA), L-homocysteate (HCA) and S-sulpho-L-cysteine (SSC) dose-dependently stimulated the formation of [3H]inositol phosphates exhibiting EC50 values in the range 60-200 microM and maximal effects of six- to 17-fold that of basal [3H]inositol phosphate levels. Endogenous L-glutamate spontaneously released into the extracellular medium or following exposure of cells to HCSA, HCA or SSC did not contribute significantly to formation of [3H]inositol phosphates, whereas 10% of the total [3H]inositol phosphates accumulated following exposure to CSA and CA was due to released L-glutamate. The selective N-methyl-D-aspartate receptor antagonist, D,L-2-amino-5-phosphonopentanoic acid (APV, 500 microM) attenuated by 20% (HCSA) to between 80 and 100% (CSA, CA, SSC, HCA) the formation of [3H]inositol phosphates induced by 1 mM sulphur-containing amino acids. When, however, HCSA was used at 100 microM (a concentration near to its EC50 for phosphoinositide hydrolysis), APV inhibited induced responses by 70%. Sulphur-containing amino acid-stimulated [3H]inositol phosphate formation was unaffected by the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 microM). Inhibition of sulphur-containing amino acid-stimulated [3H]inositol phosphate formation by co-administration of APV and CNQX was similar to that obtained in the presence of APV alone. CSA-, CA-, SSC- and HCA-stimulated [3H]inositol phosphate formation was markedly reduced by removal of Ca2+ from the extracellular medium whereas that stimulated by HCSA was less affected. A similar inhibitory profile was observed when the levels of sulphur-containing amino acid-induced increases in intracellular free calcium ([Ca2+]i) were measured in the presence of 500 microM APV; 1 mM HCSA-induced responses being inhibited by only 30% whereas responses to the remaining sulphur-containing amino acid (also at 1 mM) were inhibited by > 45%. When the sulphur-containing amino acids were used at concentrations approximating their EC50 values for phosphoinositide hydrolysis, APV inhibited the induced increases in [Ca2+]i by 70-100%. HCA and SSC co-administered with the less efficacious but selective metabotropic glutamate receptor agonist, (+-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD) at maximally effective concentrations (1 mM) of each agonist stimulated [3H]inositol phosphate formation in an additive manner.(ABSTRACT TRUNCATED AT 400 WORDS)

L-trans-pyrrolidine-2,4-dicarboxylate and cis-1-aminocyclobutane-1,3-dicarboxylate behave as transportable, competitive inhibitors of the high-affinity glutamate transporters

The ability of two conformationally restricted analogues of L-glutamate to function as non-transportable inhibitors of plasma membrane L-glutamate transport was investigated in primary cultures of cerebellar granule cells and cortical astrocytes. L-trans-Pyrrolidine-2,4-dicarboxylic acid (L-trans-PDC) and cis-1-aminocyclobutane-1,3-dicarboxylic acid (cis-ACBD) behaved as linear competitive inhibitors of the uptake of D-[3H]aspartate (used as a non-metabolizable analogue of L-glutamate) exhibiting Ki values between 40 and 145 microM; L-trans-PDC being the more potent inhibitor in each preparation. However, both L-trans-PDC and cis-ACBD, over a concentration range of 1 microM-5 mM, dose-dependently stimulated the release of exogenously supplied D-[3H]aspartate from granule cells maintained in a continuous superfusion system. The stimulated release was independent of extracellular calcium ions; essentially superimposable dose-response profiles being obtained in the absence and presence of 1.3 mM CaCl2 and yielding EC50 values of 16-25 microM and 180-220 microM for L-trans-PDC and cis-ACBD, respectively. Stimulated release of D-[3H]aspartate was unaffected by either 300 microM D-(-)-2-amino-5-phosphonopentanoic acid [D-APV; a selective antagonist of the N-methyl-D-aspartate (NMDA) receptor] or by 25 microM 6-cyano-7-nitroquinoxaline-2,3-dione [CNQX; a selective antagonist of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptor]. The release of D-[3H]-aspartate following stimulation by either L-trans-PDC or cis-ACBD was however markedly attenuated following substitution in the superfusion medium of sodium ions by choline ions. Taken together, these results support an action of L-trans-PDC and cis-ACBD consistent with that of being competitive substrates rather than non-transportable blockers of the plasma membrane L-glutamate uptake system.

Identifying priorities of psychosocial need in cancer patients

Inconsistent findings on the efficacy of psychosocial interventions in cancer may be due to their lack of specificity. The aim of this study was to identify priorities of psychosocial need among cancer patients currently receiving treatment in Western Sydney (NSW) as a prelude to targeted intervention. A sample of 188 patients (129 female, median age 52 years, median time since diagnosis 12 months), with various solid tumours, completed a self-report ranking questionnaire listing eight major areas of psychosocial need based on a literature search of relevant studies. The resulting ranking of priorities was: family (1), dealing with emotional stress (2), getting information (3), money (4), work (5), social life (6), sex life (7), and dealing with hospital staff (8). These priorities were independent of demographic characteristics, including time since diagnosis, suggesting that support in the areas of major need may be just as important during follow-up as it is at diagnosis. Males reported less distress than females, and patients with cancer of the head/neck or breast reported most distress. To be maximally effective, psychosocial intervention for cancer patients should focus on the principal areas of family interaction, effective stress management, and access to information.

Effects of aging and alcohol on the biochemical composition of histologically normal human brain

Human brains were removed at autopsy and examined grossly and histologically for any abnormality or evidence of disease. Sixty-two brains appearing normal by these criteria were examined further. First, a detailed record of alcohol consumption was obtained. Second, frozen punches of gray and white matter were used to determine the compositional change associated with age and drinking patterns. Increased age was associated with an increase in the water content, particularly in the white matter, a decline in RNA content in gray matter, a decline in total protein in white matter, and a decline in both myelin and the myelin-like subfraction. The loss of myelin membrane in white matter corresponded to a similar increase in water content, although there was an additional loss of some nonmyelin protein. There was no significant shift in the density between the myelin and the myelin-like membranes, and the protein composition of myelin was not significantly altered by age. A history of heavy alcohol consumption was associated with a relative increase in total protein in white matter even though heavy drinking accelerated the age-related loss of myelin. Presumably, alcohol produced a lag in the rate at which nonmyelin proteins are lost or accelerated the accumulation of abnormal protein. Alcohol consumption did not influence the myelin composition or the ratio of myelin and myelin-like membranes. The interval between patient death and autopsy was shown to have little or no effect on the samples used in this study. These data show that normal aging, uncomplicated by other disease processes, can have a significant effect on the composition of brain tissue, particularly the white matter, and that heavy alcohol consumption accelerates degenerative change, even in tissue appearing normal by histology.

Peroxidative aggregation of myelin membrane proteins

The exposure of CNS myelin to reactive oxygen species (ROS) generated by a Cu2+-H2O2 system results in the aggregation of membrane proteins. Integral and peripheral membrane proteins are equally vulnerable and the denaturation is not mediated by the SH groups. The aggregated proteins retain their original antigenicity as determined by immunoblot technique. The aggregation of proteins is not limited to myelin and can be elicited in the preparation of other cerebral membranes. The effect of ROS on membrane proteins can also be demonstrated in cerebral slices incubated in the presence of the ROS-generating system. Furthermore, the peroxidation inactivates membrane-bound enzymes as exemplified by myelin cyclic nucleotide phosphatase (CNP). Competitive inhibition studies with various scavengers and quenchers of ROS implicate singlet oxygen as a major mediator in the Cu2+-H2O2 oxidizing system responsible for the peroxidative aggregation of membrane proteins.

Effect of ascorbic acid deficiency on serum ferritin concentration in patients with beta-thalassaemia major and iron overload

The incidence of ascorbic acid (AA) deficiency and its effect on serum ferritin concentration relative to body iron stores was studied in 61 unchelated patients with beta-thalassaemia major. Thirty-nine (64%) of patients had subnormal leucocyte ascorbate concentrations without clinical evidence of scurvy. The lowest leucocyte ascorbate concentrations tended to occur in the most transfused patients. No correlation was found between the units transfused and serum ferritin concentration in the AA-deficient patients but a close correlation (r = +0.82; p less than 0.005) existed for the AA-replete group. Similarly a close correlation (r = +0.77; p less than 0.005) was obtained between liver iron concentration and serum ferritin in AA-replete patients but only a weak correlation (r = +0.385; p less than 0.025) existed for the AA-deficient group. When AA-deficient patients were treated with ascorbic acid, serum iron and percentage saturation of iron binding capacity rose significantly; serum ferritin rose in 13 of 21 patients despite the simultaneous commencement of desferrioxamine therapy. In contrast all three measurements tended to fall in AA-replete patients with ascorbic acid and desferrioxamine therapy. Thus, AA deficiency is commonly present in beta-thalassaemia patients with iron overload and may give rise to inappropriate serum ferritin concentrations in relation to body iron stores.

Binding of serum ferritin to concanavalin A in patients with iron overload and with chronic liver disease

Total serum ferritin and the proportion of serum ferritin binding to concanavalin A (glycosylated ferritin) was measured in 18 healthy volunteers and in 84 patients, eight with primary haemochromatosis, 43 with beta-thalassaemia major and secondary iron overload and 33 with chronic liver diseases without iron overload. The total serum ferritin was either equally or even more closely related than either the non-binding or the concanavalin A binding ferritin, to the liver iron concentration in all patients with iron overload, and with the units of blood transfused in non-chelated thalassaemic patients. The total serum ferritin showed a significant correlation with serum aminotransferase for the group of 84 patients. In the thalassaemic patients the ferritin binding to concanavalin A also correlated with aminotransferase. However, in the other groups it was the ferritin not binding to concanavalin A which showed a significant correlation with aminotransferase activity. These results suggest that measuring the fraction of serum ferritin which binds to concanavalin A does not offer any advantage over estimation of the total serum ferritin concentration in the assessment of iron stores in patients wit iron overload and liver damage.

Mechanical haemolytic anaemia after valve repair operations for non-rheumatic mitral regurgitation

Two cases are described in which severe mechanical haemolytic anaemia developed shortly after operation for repair of non-rheumatic mitral regurgitation. One patient had a "floppy" valve and the other cleft mitral leaflets, and both had chordal rupture. In both there was residual regurgitation after repair though in one this was initially only trivial. Clinically manifest haemolysis ceased after replacement of the valve by a frame-mounted xenograft. There are two previously reported cases in which haemolytic anaemia followed an unsuccessful mitral valve repair operation. Subclinical haemolysis or mild haemolytic anaemia may occur with unoperated valve lesions, but hitherto frank haemolytic anaemia has been observed only when turbulent blood flow is associated with the presence of a prosthetic valve or patch of prosthetic fabric. In these four cases, however, polyester or Teflon sutures were the only foreign material, and it is suggested that when these are used for the repair of leaflets, particularly in non-rheumatic mitral valve disease, they may increase the damaging effect of turbulence on circulating red blood cells.

Improvement in iron status and liver function in patients with transfusional iron overload with long-term subcutaneous desferrioxamine

Subcutaneous desferrioxamine (2--4 g over 12 h) was administered 6 nights each week to 34 patients with transfusional iron overloads who continued to receive regular blood-transfusions. All 34 patients showed a fall in serum-ferritin after 5 to 12 months. In some patients serum-ferritin fell almost to normal. Liver function improved in all the patients, serum-aspartate-transaminase levels fell in all 17 patients tested, and liver-iron fell in 5 of 6 patients tested. These studies show that body-iron stores can be substantially reduced, to normal or near normal levels, by long-term subcutaneous desferrioxamine in patients with transfusional iron overload despite the need for continued blood-transfusion. They also show that removal of iron is accompanied by improved organ function.