Autologous T cell therapy for MAGE-A4+ solid cancers in HLA-A*02+ patients: a phase 1 trial

Affinity-optimized T cell receptors can enhance the potency of adoptive T cell therapy. Afamitresgene autoleucel (afami-cel) is a human leukocyte antigen-restricted autologous T cell therapy targeting melanoma-associated antigen A4 (MAGE-A4), a cancer/testis antigen expressed at varying levels in multiple solid tumors. We conducted a multicenter, dose-escalation, phase 1 trial in patients with relapsed/refractory metastatic solid tumors expressing MAGE-A4, including synovial sarcoma (SS), ovarian cancer and head and neck cancer ( NCT03132922 ). The primary endpoint was safety, and the secondary efficacy endpoints included overall response rate (ORR) and duration of response. All patients (N = 38, nine tumor types) experienced Grade ≥3 hematologic toxicities; 55% of patients (90% Grade ≤2) experienced cytokine release syndrome. ORR (all partial response) was 24% (9/38), 7/16 (44%) for SS and 2/22 (9%) for all other cancers. Median duration of response was 25.6 weeks (95% confidence interval (CI): 12.286, not reached) and 28.1 weeks (95% CI: 12.286, not reached) overall and for SS, respectively. Exploratory analyses showed that afami-cel infiltrates tumors, has an interferon-γ-driven mechanism of action and triggers adaptive immune responses. In addition, afami-cel has an acceptable benefit-risk profile, with early and durable responses, especially in patients with metastatic SS. Although the small trial size limits conclusions that can be drawn, the results warrant further testing in larger studies.

373 Enhancement of TCR-engineered T-cells targeting MAGE-A4 antigen by co-expression of CD8α and inhibition of AKT signaling during ex vivo T-cell expansion

Background

Autologous Specific Peptide Enhanced Affinity Receptor (SPEAR) T-cells targeting MAGE-A4 can be effective treatment for solid tumors.1–3 To improve efficacy, we developed a next-generation SPEAR-T cell targeting MAGE-A4 co-expressing CD8α (ADP-A2M4CD8). ADP-A2M4CD8 is under investigation in the Phase 1 SURPASS trial (NCT04044859). Enhancements have also been made to the manufacturing process with an AKT inhibitor (AKTi) during ex vivo expansion to provide a greater proliferative potential and enhanced memory phenotype.4

Methods

SPEAR-T cells were manufactured using a Lentiviral vector with CD8α and MAGE-A4 targeted TCR genes. AKTi was added during ex vivo expansion. T-cell attributes were evaluated, including markers of differentiation (flow cytometry), capacity for in vitro tumor lysis (Incucyte) and changes to gene expression (scRNASeq) initially assessed with the first-gen product. Post-infusion, the presence of transduced T-cells in the peripheral circulation (PCR) and levels of inflammatory cytokines in serum (MesoScale Discovery Assay [MSD]) were evaluated.

Results

As of May 24, 2021, 18 patients with 9 different primary tumor types were evaluable. Twelve pts received product that had AKTi during manufacture. Five patients had objective responses (RECIST), and 10 had stable disease. Responses occurred at lower MAGE-A4 expression levels and lower transduced T-cell doses relative to the first-gen product targeting MAGE-A4.1 CD4 T-cells from manufactured ADP-A2M4CD8 demonstrated direct in vitro tumor cell killing similar to CD8+ T-cells (Incucyte). scRNASeq gene expression profiles of first-gen ADP-A2M4 product manufactured with AKTi revealed the AKTi-expanded T-cells had a greater proliferation or an enhanced memory phenotype; scRNASeq analyses are ongoing for the ADP-A2M4CD8 product.An increase in IL-12 levels (MSD) in serum post-infusion suggests that endogenous immune cells are being activated, further resulting in increased levels of IFN gamma (MSD) secretion relative to patients who received first-gen product. Manufacturing with AKTi resulted in T-cells with a less differentiated phenotype (flow cytometry), and post-infusion was associated with enhanced antigen-specific serum cytokine responses, increased proliferative state (i.e., elevated levels of IL-2), and higher persistence of T-cells in peripheral blood by PCR.

Conclusions

SPEAR T-cells targeting MAGE-A4 expressing cancers have been enhanced by co-expressing CD8α and adding AKTi during manufacture. These enhanced products improve CD4+ T-cell killing, release more inflammatory cytokines, proliferate more robustly with an early memory phenotype, and better engage the patient‘s endogenous immune system when compared to first-gen products or next-gen manufactured without AKTi.

Trial Registration

NCT04044859

References

Hong, et al. ASCO 2020.

D’Angelo, et al. ASCO 2021.

Hong, et al. SITC 2020.

Mardilovich, et al. SITC 2020.

Synchronous oral cavity malignancy in identical twins-unusual coincidence of similarities

The multifactorial nature of head and neck squamous cell carcinoma (HNSCC) has led to increased efforts in establishing various risk factors. Well-known environmental risk factors for HNSCC include tobacco use, heavy alcohol consumption, immunosuppression, and more recently human papillomavirus infection. Familial clustering has been observed in cancers occurring at other sites, but not so much with oral squamous cell carcinoma (OSCC) without exposure to shared environmental risk factors. An unusual case of identical twins who presented with OSCC involving an identical site and exhibiting similar histological features is reported here. The two patients underwent identical surgery with curative intent, culminating in good outcomes. It appears that no other cases of identical twins with a similar presentation in time, anatomical site, and histopathology have been reported in the literature.

Systemic and local immunity following adoptive transfer of NY-ESO-1 SPEAR T cells in synovial sarcoma

Background

Gene-modified autologous T cells expressing NY-ESO-1^c259, an affinity-enhanced T-cell receptor (TCR) reactive against the NY-ESO-1-specific HLA-A*02-restricted peptide SLLMWITQC (NY-ESO-1 SPEAR T-cells; GSK 794), have demonstrated clinical activity in patients with advanced synovial sarcoma (SS). The factors contributing to gene-modified T-cell expansion and the changes within the tumor microenvironment (TME) following T-cell infusion remain unclear. These studies address the immunological mechanisms of response and resistance in patients with SS treated with NY-ESO-1 SPEAR T-cells.

Methods

Four cohorts were included to evaluate antigen expression and preconditioning on efficacy. Clinical responses were assessed by RECIST v1.1. Engineered T-cell persistence was determined by qPCR. Serum cytokines were evaluated by immunoassay. Transcriptomic analyses and immunohistochemistry were performed on tumor biopsies from patients before and after T-cell infusion. Gene-modified T-cells were detected within the TME via an RNAish assay.

Results

Responses across cohorts were affected by preconditioning and intra-tumoral NY-ESO-1 expression. Of the 42 patients reported (data cut-off 4June2018), 1 patient had a complete response, 14 patients had partial responses, 24 patients had stable disease, and 3 patients had progressive disease. The magnitude of gene-modified T-cell expansion shortly after infusion was associated with response in patients with high intra-tumoral NY-ESO-1 expression. Patients receiving a fludarabine-containing conditioning regimen experienced increases in serum IL-7 and IL-15. Prior to infusion, the TME exhibited minimal leukocyte infiltration; CD163⁺ tumor-associated macrophages (TAMs) were the dominant population. Modest increases in intra-tumoral leukocytes (≤5%) were observed in a subset of subjects at approximately 8 weeks. Beyond 8 weeks post infusion, the TME was minimally infiltrated with a TAM-dominant leukocyte infiltrate. Tumor-associated antigens and antigen presentation did not significantly change within the tumor post-T-cell infusion. Finally, NY-ESO-1 SPEAR T cells trafficked to the TME and maintained cytotoxicity in a subset of patients.

Conclusions

Our studies elucidate some factors that underpin response and resistance to NY-ESO-1 SPEAR T-cell therapy. From these data, we conclude that a lymphodepletion regimen containing high doses of fludarabine and cyclophosphamide is necessary for SPEAR T-cell persistence and efficacy. Furthermore, these data demonstrate that non-T-cell inflamed tumors, which are resistant to PD-1/PD-L1 inhibitors, can be treated with adoptive T-cell based immunotherapy.

Trial registration

ClinicalTrials.gov, NCT01343043, Registered 27 April 2011.

Transiently Activated Human Regulatory T Cells Upregulate BCL-XL Expression and Acquire a Functional Advantage in vivo

Regulatory T cells (Tregs) can control excessive or undesirable immune responses toward autoantigens, alloantigens, and pathogens. In transplantation, host immune responses against the allograft are suppressed through the use of immunosuppressive drugs, however this often results in life-threatening side effects including nephrotoxicity and an increased incidence of cancer and opportunistic infections. Tregs can control graft-vs.-host disease and transplant rejection in experimental models, providing impetus for the use of Tregs as a cellular therapy in clinical transplantation. One of the major barriers to the widespread use of Treg cellular therapy is the requirement to expand cells ex vivo to large numbers in order to alter the overall balance between regulatory and effector cells. Methods that enhance suppressive capacity thereby reducing the need for expansion are therefore of interest. Here, we have compared the function of freshly-isolated and ex vivo-manipulated human Tregs in a pre-clinical humanized mouse model of skin transplantation. Sorted human CD127^loCD25⁺CD4⁺ Tregs were assessed in three different conditions: freshly-isolated, following transient in vitro activation with antiCD3/antiCD28 beads or after ex vivo-expansion for 2 weeks in the presence of antiCD3/antiCD28 beads and recombinant human IL2. While ex vivo-expansion of human Tregs increased their suppressive function moderately, transient in vitro-activation of freshly isolated Tregs resulted in a powerful enhancement of Treg activity sufficient to promote long-term graft survival of all transplants in vivo. In order to investigate the mechanisms responsible for these effects, we measured the expression of Treg-associated markers and susceptibility to apoptosis in activated Tregs. Transiently activated Tregs displayed enhanced survival and proliferation in vitro and in vivo. On a molecular level, Treg activation resulted in an increased expression of anti-apoptotic BCL2L1 (encoding BCL-XL) which may be at least partially responsible for the observed enhancement in function. Our results suggest that in vitro activation of human Tregs arms them with superior proliferative and survival abilities, enabling them to more effectively control alloresponses. Importantly, this transient activation results in a rapid functional enhancement of freshly-isolated Tregs, thereby providing an opportunity to eliminate the need for in vitro expansion in select circumstances. A protocol employing this technique would therefore benefit from a reduced requirement for large cell numbers for effective therapy.

Antitumor Activity Associated with Prolonged Persistence of Adoptively Transferred NY-ESO-1 c259T Cells in Synovial Sarcoma

We evaluated the safety and activity of autologous T cells expressing NY-ESO-1^c259, an affinity-enhanced T-cell receptor (TCR) recognizing an HLA-A2-restricted NY-ESO-1/LAGE1a-derived peptide, in patients with metastatic synovial sarcoma (NY-ESO-1^c259T cells). Confirmed antitumor responses occurred in 50% of patients (6/12) and were characterized by tumor shrinkage over several months. Circulating NY-ESO-1^c259T cells were present postinfusion in all patients and persisted for at least 6 months in all responders. Most of the infused NY-ESO-1^c259T cells exhibited an effector memory phenotype following ex vivo expansion, but the persisting pools comprised largely central memory and stem-cell memory subsets, which remained polyfunctional and showed no evidence of T-cell exhaustion despite persistent tumor burdens. Next-generation sequencing of endogenous TCRs in CD8⁺ NY-ESO-1^c259T cells revealed clonal diversity without contraction over time. These data suggest that regenerative pools of NY-ESO-1^c259T cells produced a continuing supply of effector cells to mediate sustained, clinically meaningful antitumor effects.Significance: Metastatic synovial sarcoma is incurable with standard therapy. We employed engineered T cells targeting NY-ESO-1, and the data suggest that robust, self-regenerating pools of CD8⁺ NY-ESO-1^c259T cells produce a continuing supply of effector cells over several months that mediate clinically meaningful antitumor effects despite prolonged exposure to antigen. Cancer Discov; 8(8); 944-57. ©2018 AACR.See related commentary by Keung and Tawbi, p. 914This article is highlighted in the In This Issue feature, p. 899.

Improvement of BCG protective efficacy with a novel chimpanzee adenovirus and a modified vaccinia Ankara virus both expressing Ag85A

A replication-deficient chimpanzee adenovirus expressing Ag85A (ChAdOx1.85A) was assessed, both alone and in combination with modified vaccinia Ankara also expressing Ag85A (MVA85A), for its immunogenicity and protective efficacy against a Mycobacterium tuberculosis (M.tb) challenge in mice. Naïve and BCG-primed mice were vaccinated or boosted with ChAdOx1.85A and MVA85A in different combinations. Although intranasally administered ChAdOx1.85A induced strong immune responses in the lungs, it failed to consistently protect against aerosol M.tb challenge. In contrast, ChAdOx1.85A followed by MVA85A administered either mucosally or systemically, induced strong immune responses and was able to improve the protective efficacy of BCG. This vaccination regime has consistently shown superior protection over BCG alone and should be evaluated further.

Stromal infiltration of CD8 T cells is associated with improved clinical outcome in HPV-positive oropharyngeal squamous carcinoma

BACKGROUND

Patients with human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) have a better prognosis than those with HPV-negative tumours. There is interest in de-escalating their treatment but strategies are needed for risk stratification to identify subsets with a poor prognosis. This study investigated tumour-infiltrating lymphocytes (TILs) in relation to HPV tumour status and patient survival.

METHODS

Biopsies from 218 patients diagnosed with OPSCC between 2002 and 2011, who underwent chemo/radiotherapy were analysed for HPV by PCR, in-situ hybridisation and p16 immunohistochemistry (IHC). One hundred and thirty-nine samples with concordant HPV detection were analysed for CD3, CD4, CD8 and FoxP3 expression in tumour and stromal regions using multiplexIHC and multispectral image analysis. Labelling of smooth muscle actin (SMA) identified activated stroma.

RESULTS

Human papillomavirus-positive compared with HPV-negative OPSCC had higher infiltration in both tumour and stromal areas of CD4 and CD8 T cells but not FoxP3 T regulatory cells. Only CD3+CD8+ stromal and not tumour area infiltration was associated with increased survival (P=0.02). There was significantly higher SMA expression in HPV-positive compared with -negative tumours, which did not correlate with survival.

CONCLUSIONS

Studies of TILs for risk stratification in OPSCC should assess stromal infiltration.

Nasopharyngeal carcinoma: a retrospective review of demographics, treatment and patient outcome in a single centre

AIMS

Nasopharyngeal cancer (NPC) is relatively uncommon, especially in the Western world. We report our single institution experience of 20 years of data in 128 patients with NPC, including responses to different treatment modalities and outcomes by histological subtype.

MATERIALS AND METHODS

NPC patients presenting from 1992 to 2005 were located on the cancer registry database. Demographic data included age, gender, length of presenting symptoms and stage. World Health Organization classification (2005) was used for histological subtyping. The date of recurrence and survival outcomes were analysed using Kaplan-Meier curves.

RESULTS

Presentation data were analysed from 128 patients; the survival analysis included 123 patients. The median age at presentation was 57.7 years. Stage III and IV presentation rates were 34 and 38%, respectively. The most common presenting symptom was a palpable neck lump (55%) and the median duration of symptoms was 16 weeks. Forty-eight patients received radiotherapy alone and 75 received chemoradiotherapy. The median overall survival in chemoradiotherapy patients was 80.3 months versus 28.5 months with radiotherapy alone (P = 0.003). A significant difference was also seen with recurrence-free survival (RFS) (P = 0.017). Type 1 keratinising carcinoma had a significantly worse overall survival (P = 0.04) and a similar but non-statistically significant trend was seen for RFS (P = 0.051). The multivariate analysis for overall survival showed that histological subtype (hazard ratio 2.7, 95% confidence interval 1.3-5.5, P = 0.034), age (hazard ratio 2.3, 95% confidence interval 1.1-4.9, P = 0.018) and N stage (hazard ratio 3.7, 95% confidence interval 1.4-9.4, P = 0.024) were prognostic factors.

CONCLUSIONS

We present the first large-scale, single-centre retrospective review of NPC in a UK-based population. Demographic data were similar to that in other Western populations, with a significantly worse survival outcome in the keratinising group. Further prospective study of outcome in Western populations accounting for newer radiotherapy techniques such as intensity-modulated radiotherapy and dose escalation, particularly in the keratinising population who were more likely to present with an isolated local recurrence, is recommended.

Optimising immunogenicity with viral vectors: mixing MVA and HAdV-5 expressing the mycobacterial antigen Ag85A in a single injection

The Bacillus Calmette - Guerin (BCG) vaccine provides a critical but limited defense against Mycobacterium tuberculosis (M.tb). More than 60 years after the widespread introduction of BCG, there is an urgent need for a better vaccine. A large body of pre-clinical research continues to support ongoing clinical trials to assess whether viral vectors expressing M.tb antigens that are shared by BCG and M.tb, can be used alongside BCG to enhance protection. A major focus involves using multiple unique viral vectors to limit anti-vector immunity and thereby enhance responses to the insert antigen delivered. The successful introduction of viral vector vaccines to target M.tb and other pathogens will be reliant on reducing the costs when using multiple vectors and inhibiting the development of unwanted anti-vector responses that interfere with the response to insert antigen. This study examines methods to reduce the logistical costs of vaccination by mixing different viral vectors that share the same insert antigen in one vaccine; and whether combining different viral vectors reduces anti-vector immunity to improve immunogenicity to the insert antigen. Here we show that a homologous prime-boost regimen with a mixture of MVA (Modified Vaccinia virus Ankara) and Ad5 (human adenovirus type 5) vectors both expressing Ag85A in a single vaccine preparation is able to reduce anti-vector immunity, compared with a homologous prime-boost regimen with either vector alone. However, the level of immunogenicity induced by the homologous mixture remained comparable to that induced with single viral vectors and was less immunogenic than a heterologous Ad5 prime-MVA-boost regimen. These findings advance the understanding of how anti-vector immunity maybe reduced in viral vector vaccination regimens. Furthermore, an insight is provided to the impact on vaccine immunogenicity from altering vaccination methods to reduce the logistical demands of using separate vaccine preparations in the field.

Suppression of tumour-specific CD4⁺ T cells by regulatory T cells is associated with progression of human colorectal cancer

BACKGROUND

There is indirect evidence that T cell responses can control the metastatic spread of colorectal cancer (CRC). However, an enrichment of CD4(+)Foxp3(+) regulatory T cells (Tregs) has also been documented.

OBJECTIVE

To evaluate whether CRC promotes Treg activity and how this influences anti-tumour immune responses and disease progression.

METHODS

A longitudinal study of Treg activity on a cohort of patients was performed before and after tumour resection. Specific CD4(+) T cell responses were also measured to the tumour associated antigens carcinoembryonic antigen (CEA) and 5T4.

RESULTS

Tregs from 62 preoperative CRC patients expressed a highly significant increase in levels of Foxp3 compared to healthy age-matched controls (p=0.007), which returned to normal after surgery (p=0.0075). CD4(+) T cell responses to one or both of the tumour associated antigens, CEA and 5T4, were observed in approximately two-thirds of patients and one third of these responses were suppressed by Tregs. Strikingly, in all patients with tumour recurrence at 12 months, significant preoperative suppression was observed of tumour-specific (p=0.003) but not control CD4(+) T cell responses.

CONCLUSION

These findings demonstrate that the presence of CRC drives the activity of Tregs and accompanying suppression of CD4(+) T cell responses to tumour-associated antigens. Suppression is associated with recurrence of tumour at 12 months, implying that Tregs contribute to disease progression. These findings offer a rationale for the manipulation of Tregs for therapeutic intervention.

Mitochondrial DNA mutations in head and neck cancer are infrequent and lack prognostic utility

Background:

Mitochondrial DNA (mtDNA) mutations occur in head and neck squamous cell carcinoma (HNSCC) and are most frequently detected in the displacement-loop (D-loop) region. The D-loop is considered to be important because it controls mitochondrial gene expression and mtDNA replication. There is currently no evidence that mtDNA mutations can be used as prognostic or predictive biomarkers in HNSCC.

Methods:

We used denaturing high performance liquid chromatography to screen the entire mitochondrial genome of six oral squamous cell carcinoma-derived cell lines and then focused on detecting D-loop abnormalities in 34 HNSCC tissue samples.

Results:

Mitochondrial DNA mutations are not ubiquitous in HNSCC because only half of the cell lines had detectable mtDNA abnormalities following screening of the entire mitochondrial genome and only 18% (6 of 34) of tissue samples had D-loop mutations. There was no correlation between D-loop mutations and determinates of clinical outcome; specifically, tumour stage and the expression of hypoxia-inducible genes included in a highly prognostic hypoxia metagene.

Conclusions:

Taken together, these data suggest that mtDNA D-loop mutations are stochastic events that may not significantly influence the biology of HNSCC and supports the hypothesis that mtDNA mutations in cancer represent bystander genotoxic damage as a consequence of tumour development and progression.

Expansion of hepatitis C-specific CD4+CD25+ regulatory T cells after viral clearance: a mechanism to limit collateral damage?

BACKGROUND

Data from rodent models suggest that a subpopulation of CD4+ T cells, characterized by the constitutive expression of CD25, play a key role in regulating many immune responses. Human CD4+CD25+ T cells also appear to possess a regulatory function, but their role in infections is not fully defined.

OBJECTIVES

We sought to explore the possibility of a role for CD4+CD25+ T cells in controlling immunity to hepatitis C virus (HCV). We hypothesized that CD4+CD25+ T cells might account for the paucity of immune responses measurable in chronically viremic patients by suppressing the immune responses to HCV antigens.

METHODS

We compared the responses of PBMCs to 3 different recombinant HCV antigens before and after depletion of CD25+ cells in 15 chronically viremic patients, 14 nonviremic HCV antibody-positive subjects, and 14 healthy control subjects. We also tested the ability of CD4+CD25+ T cells purified from HLA-matched viremic or nonviremic blood to suppress the responses of HCV epitope-specific T-cell clones.

RESULTS

To our surprise, depletion of peripheral blood CD25+ cells led to a pronounced increase in proliferation of and IFN-gamma production by PBMCs only in nonviremic patients. Furthermore, the CD4+CD25+ T cells purified from HLA-matched nonviremic blood (in contrast to CD4+CD25+ T cells isolated from chronically viremic blood) inhibited the responses of HCV epitope-specific T-cell clones.

CONCLUSION

HCV-specific CD4+CD25+ regulatory T cells appear to accompany successful viral clearance.

The impact of regulatory T cells on carcinogen-induced sarcogenesis

Burnet proposed in the 1950's that the immune system is engaged in identifying and destroying abnormal cancerous cells. This process, termed immune surveillance, has been at the centre of intense debate for decades. Results using immunodeficient mice lend support to the immune surveillance hypothesis. We surmised that immune surveillance would be hampered by the inhibitory effect of naturally occurring FoxP3(+) regulatory T cells, a population of T cells shown to be present at an increased frequency in a variety of human tumours. The carcinogen, methylcholanthrene was injected subcutaneously into mice and the steady development of fibrosarcomas was observed over approximately 200 days. These fibrosarcomas were strikingly infiltrated with FoxP3(+) regulatory T cells implying that these cells impinge upon immune-mediated rejection of the tumour. This was confirmed by partial ablation of FoxP3(+) regulatory T-cell activity, which resulted in a marked reduction in tumour incidence. The reduction of tumour incidence was ablated in mice that lacked interferon gamma. These data offer strong support for the concept of immune surveillance and indicate that this process is limited by the inhibitory effect of FoxP3(+) regulatory T cells.

Regulatory T cells inhibit Fas ligand-induced innate and adaptive tumour immunity

CD4+CD25+ regulatory T cells (Treg) are known to influence T cell responses to tumours. Here we have explored the role of Treg in inhibiting not only adaptive, but also innate immune responses to tumours. To this end we used a Fas ligand (FasL)-expressing melanoma cell line in a mouse model. In this system, innate immunity is sufficient to reject the tumour. All mice depleted of Treg and challenged with FasL-expressing melanoma remained tumour-free. Investigation of the underlying cellular effector mechanisms revealed that depletion of Treg enhanced an NK cell response capable of tumour lysis. Furthermore, this initial innate immune response primed mice to make an effective adaptive immune response leading to complete rejection of challenge with the parental melanoma. Both antigen-specific antibody and CD4+ T cells were implicated in protection via adaptive immunity. We conclude that removal of Treg and vaccination with whole tumour cells expressing FasL activates multiple arms of the immune system, leading to efficient tumour rejection. These findings highlight a novel role for FasL in inducing innate immune responses that are normally inhibited by Treg and uncover an adjuvant effect of FasL that can be used to stimulate tumour immunity after depletion of Treg.

Perception of fear, distress and pain by parents of children undergoing a micturating cystourethrogram: a prospective study

OBJECTIVES

To investigate whether parents' expectations of their child's fear, distress or pain during a micturating cystourethrogram (MCU) are realized.

METHODOLOGY

Prospective study in which parents were asked to fill out two questionnaires using a visual analogue scale, one before (pre) and the other after the MCU procedure (post), was conducted at a tertiary level paediatric hospital in Sydney, Australia. The questionnaires were designed to compare the parents' anticipated and experienced anxiety about their child's procedure and their perception of fear, distress and pain in their child during and after the procedure. The parents' satisfaction with information provided to them on the procedure was also recorded. Twenty-five parents participated in the study.

RESULTS

There were significant differences between anticipated and experienced parental anxiety. Parents' reporting of fear, distress and pain in their child during the MCU and after the procedure was lower than they had anticipated. There was a significant correlation between the parents' anxiety and their perception of severity of their child's fear (r = 0.52, P = 0.009), distress (r = 0.48, P = 0.017) and pain (r = 0.50, P = 0.01) during the procedure, but less so with the child's distress after the procedure (r = 0.39, P = 0.059). The parents were satisfied with the information given to them regarding the MCU procedure.

CONCLUSIONS

Parents' perception of their child's fear, distress and pain during the MCU, as well as distress following the MCU, was not as severe as they had anticipated. Parental anxiety is an important factor in the perception of fear, distress and pain in children during and after the procedure.

Attachment of bacteria to beef from steam-pasteurized carcasses

The extent to which a bacterial cocktail containing equal numbers of Pseudomonas fragi NCTC 10689, Listeria monocytogenes BL5/2, Salmonella Typhimurium LT2, and Escherichia coli JM 109 attached to loin surface cuts (7 by 5 cm) derived from steam-pasteurized beef carcasses has been evaluated. The extent of attachment was categorized as loosely attached (removed by rinsing), firmly attached (released by stomaching), and irreversibly bound. No significant difference (P > 0.10) in the attachment of bacteria to steam-pasteurized carcasses was found compared with control loin samples that had received no treatment. No significant difference (P > 0.05) was also found in the attachment strength between the different bacterial species tested. Most bacteria inoculated onto the loin cuts were reversibly bound, since they had been removed by rinsing and stomaching. The irreversible attachment of bacteria to loin cuts was found to vary significantly (P < 0.01) among the different carcass sets used but was independent of whether the carcass had undergone steam pasteurization treatment. Use of a bioluminescent strain of E. coli showed that cells bound preferentially to cut edges and convoluted areas on the loin surface and could not be removed by rinsing. The possible mechanisms of bacterial attachment and the suitability of steam pasteurization to remove contamination incurred during slaughter are discussed.

Evaluation of a nursing aides scheme for elderly people

The need to provide appropriate domiciliary schemes to enable elderly people to remain in the community is of growing importance and while schemes have been initiated by health authorities, the majority of schemes have so far originated in social services departments. An evaluation of a nursing aides scheme is presented. The study examines the success of the scheme in maintaining elderly people in the community and the views and opinions of patients who have been in the scheme. On the basis of the available evidence it is likely that the intervention of the scheme enabled some elderly people to remain in the community and the majority (70%) of respondents believed that the nursing aides scheme had enabled them to stay at home.

Multiple ion-dependent and substrate-dependent Na+/K+-ATPase conformational states. Transient and steady-state kinetic studies

The hydrolysis of beta-(2-furyl)acryloyl phosphate (FAP), catalyzed by the Na+/K+-ATPase, is faster than the catalyzed hydrolysis of ATP. This is due to catalyzed hydrolysis of the pseudosubstrate by K+-dependent states of the enzyme, thus bypassing the Na+-dependent enzyme states that are required and are rate limiting in ATP hydrolysis. Unlike ATP, FAP is a positive effector of the E2 state. A study of FAP hydrolysis permits a detailed analysis of later steps in the overall ion translocation-ATP hydrolysis pathway. During the steady state of FAP hydrolysis in the presence of K+, substantial phosphoryl-enzyme is formed, as is indicated by the covalent incorporation of 32P from [32P]FAP. A comparison of the phosphoryl-enzyme yield with the rate of overall hydrolysis reveals that at 25 degrees C the phosphoryl-enzyme formed is all kinetically competent. Both the yield of phosphoryl-enzyme and the rate of overall hydrolysis of FAP are [K+] dependent. The transition E1 in equilibrium E2 is also [K+] dependent, but the rate of transition is differently affected by [K+] than are the above-mentioned two processes. Two distinct roles for K+ are indicated, as an effector of the E1-E2 equilibrium and as a "catalyst" in the hydrolysis of the E2-P. In contrast to the results at 25 degrees C, a virtually stoichiometric yield of phosphoryl-enzyme occurs at 0 degree C in the presence of Na+ and the absence of K+. At lower concentrations of K+ and in the presence of Na+, the hydrolysis of FAP at 0 degree C proceeds substantially through the E1-E2 pathway characteristic of ATP hydrolysis. The selectivity of FAP for the E2-K+-dependent pathway is due to the thermal inactivation of E1 at 25 degrees C in the absence of ATP or ATP analogues, even at high concentrations of Na+. These results emphasize the existence of multiple functional "E1" and "E2" states in the overall ATPase-ion translocation pathway.

The scope for preventive medicine in general practice in the East End

Primary care is seen as an obvious setting for preventive programmes, but a number of studies present a negative view of inner city primary care, with criticism directed particularly at older single-handed GPs. This may not be justified. A survey of 56 of the 84 GPs in the inner London borough of Tower Hamlets, found a higher than average proportion of single-handed GPs over 60 and a high level of dissatisfaction with premises. Half said they carried out some kind of preventive programme, usually hypertension screening, and three quarters were interested in doing so. Only one practice had a patient support group, but 70 per cent thought they were a good idea. Given support and help, more GPs would consider preventive programmes and set up patient support groups.

Transient and steady-state kinetic studies of sodium-potassium adenosine triphosphatase using beta-(2-furyl)acryloyl phosphate as chromophoric substrate assay

A convenient and highly specific continuous spectrophotometric assay for sodium-potassium adenosine triphosphate activity utilizing the rapidly hydrolyzed and high-affinity chromophoric substrate beta-(2-furyl)acryloyl phosphate (FAP) is described. The Na/K-ATPase-catalyzed hydrolysis of FAP is faster than that for ATP under all ionic conditions. The rate is neither inhibited nor activated by Na+; it is dependent on [K+] and on [Mg2+]. The hydrolysis of FAP to furylacrylate is accompanied by a large shift in the UV absorbance maximum. The spectrum of FAP, but not furylacrylate, is sensitive to noncovalent ligation with Mg2+, a happenstance which permits the identification of Mg2+FAP, and consequently allows for a probe of the role of Mg2+ in the catalysis. Mg2+ binding to the active site is essential for catalysis. MgFAP is more tightly bound to the site than is FAP2-, but the complex is not obligatory for catalysis. The formation of a phosphoryl-enzyme intermediate is not evident in the reaction of FAP with the enzyme. Transient kinetic experiments, utilizing an excess of MgFAP, demonstrate a unique steady-state rate-limiting production of furylacrylate. These results indicate that the pathway demonstrated with ATP is not appropriate to the FAPase mechanism. The results suggest that acyl phosphates are good "phosphatase" substrates either because they are analogues of the phosphatase-specific phosphoryl-enzyme or because they react exclusively with the isomerized "E2" form of the enzyme.