Subtotal colectomy and ileorectal anastomosis for slow transit constipation: clinical follow-up at median of 15 years.

BACKGROUND: Slow transit constipation is characterised by prolonged colonic transit and reliance on laxatives. The pathophysiology is poorly understood and in its most severe form, total colectomy with ileorectal anastomosis is the final treatment option. We present a follow-up study of the long-term function in patients who had surgery for laxative-resistant slow transit constipation. METHODS: A postal survey was sent to assess bowel frequency, abdominal pain, St Mark's continence score, satisfaction with procedure, likelihood to choose the procedure again, and long-term rates of small bowel obstruction and ileostomy. Longitudinal data from a subgroup studied 23 years previously are reported. RESULTS: Forty-two patients (male = 2) were available for follow-up out of an initial cohort of 102. Mean time since surgery was 15.9 years (range 1.7-29.7) years. Fifty percent had < 4 bowel motions per day, most commonly Bristol stool 6, mean St Mark's score 7.45. Twenty-one percent had severe incontinence. Satisfaction and likelihood to choose surgery were high (median 10/10). There was a high rate of small bowel obstruction, suggesting pan-intestinal dysmotility in some cases. Conversion to ileostomy occurred in 8 patients. In the longitudinal follow-up in 15 subjects, continence deteriorated (p < 0.01), stool consistency softened (p < 0.01), and stool frequency fell (p < 0.01). CONCLUSIONS: Satisfactory stool frequency was achieved in the long term, and although 21% had incontinence scores > 12, patient satisfaction was high. This is the longest reported follow-up of colectomy for slow transit constipation, with longitudinal outcomes reported. There was considerable attrition of patients, so larger, longitudinal studies are required to better ascertain the functional outcomes of these patients.

Effects of metal ions and hydrogen peroxide on the phenotype of yeast hom6Δ mutant.

UNLABELLED: HOM6 is a major gene in the aspartate pathway which leads to biosynthesis of threonine and methionine. The phenotypes of the gene deletion mutant (hom6∆) in a variety of cultural conditions have previously provided meaningful insights into the biological roles of HOM6 and its upstream intermediate metabolites. Here, we conducted a survey on a spectrum of metal ions for their effect on the aspartate pathway and broader sulphur metabolism. We show that manganese (Mn(2+) ) promoted the growth of hom6∆ under both anaerobic and aerobic conditions. Unexpectedly, 4 mmol l(-1) hydrogen peroxide (H2 O2 ), a dose normally causing temporary cell growth arrest, enhanced the growth of hom6∆ under the anaerobic condition only, while it had no effect on the wild type strain BY4743. We propose that Mn(2+) and H2 O2 promote the growth of hom6∆ by reducing the accumulation of the toxic intermediate metabolite-aspartate ß-semialdehyde, via directing the aspartate pathway to the central sugar metabolism-tricarboxylic acid cycle. SIGNIFICANCE AND IMPACT OF THE STUDY: This study focuses on the yeast strain which lacks homoserine dehydrogenase encoded by HOM6 gene in aspartate metabolism. The HOM6-deletion mutant (hom6Δ) was analysed in the context of varying environmental parameters such as metal ions and oxidants, under anaerobic and aerobic conditions. We demonstrated that both manganese and hydrogen peroxide can promote the growth of hom6Δ, with the latter exerting such effect only under anaerobic condition. The findings are relevant to the research areas of ageing and anti-fungal drug development. It highlights the importance of interactions between gene expression and environmental factors as well as culture conditions.

Achieving cardiac rehabilitation uptake targets: What is the value case for commissioners? A UK case-study.

Cardiac Rehabilitation (CR) has become an established intervention to support patient recovery after a cardiac event, with evidence supporting its effectiveness and cost-effectiveness in improving patient health and reducing future burden on healthcare systems. However, this evidence has focussed on the national value case for CR rather than at the point at which it is commissioned. This analysis uses the UK as a case-study to explore variation in current CR engagement and disassemble the value case from a commissioner perspective. Using data collected by the National Audit of CR (NACR), and an existing model of cost-effectiveness, we present details on the current level of CR uptake by commissioning region (Specialist Clinical Networks) in light of the current UK target of achieving 85% uptake. We then interrogate the value case for achieving the target at a commissioner level, highlighting the expected profile of health benefits and healthcare system costs over the long-term. Importantly we consider where this may differ from the national value case. Each commissioning region has a unique level of CR uptake and sociodemographic profile. Concurrently, the value case for commissioning CR relies on the upfront cost of the service being offset by long-term healthcare savings, and health improvements. The shift in the UK and internationally to more localised commissioning necessitates evidence of cost-effectiveness that better reflects the realities of those decision makers. This paper provides vital additional data to facilitate such commissioners to understand the value case in increasing CR uptake in line with national policy.

Systematic development and feasibility testing of a multibehavioural digital prehabilitation intervention for patients approaching major surgery (iPREPWELL): A study protocol.

Improving outcomes for people undergoing major surgery, specifically reducing perioperative morbidity and mortality remains a global health challenge. Prehabilitation involves the active preparation of patients prior to surgery, including support to tackle risk behaviours that mediate and undermine physical and mental health and wellbeing. The majority of prehabilitation interventions are delivered in person, however many patients express a preference for remotely-delivered interventions that provide them with tailored support and the flexibility. Digital prehabilitation interventions offer scalability and have the potential to benefit perioperative healthcare systems, however there is a lack of robustly developed and evaluated digital programmes for use in routine clinical care. We aim to systematically develop and test the feasibility of an evidence and theory-informed multibehavioural digital prehabilitation intervention 'iPREPWELL' designed to prepare patients for major surgery. The intervention will be developed with reference to the Behaviour Change Wheel, COM-B model, and the Theoretical Domains Framework. Codesign methodology will be used to develop a patient intervention and accompanying training intervention for healthcare professionals. Training will be designed to enable healthcare professionals to promote, support and facilitate delivery of the intervention as part of routine clinical care. Patients preparing for major surgery and healthcare professionals involved with their clinical care from two UK National Health Service centres will be recruited to stage 1 (systematic development) and stage 2 (feasibility testing of the intervention). Participants recruited at stage 1 will be asked to complete a COM-B questionnaire and to take part in a qualitative interview study and co-design workshops. Participants recruited at stage 2 (up to twenty healthcare professionals and forty participants) will be asked to take part in a single group intervention study where the primary outcomes will include feasibility, acceptability, and fidelity of intervention delivery, receipt, and enactment. Healthcare professionals will be trained to promote and support use of the intervention by patients, and the training intervention will be evaluated qualitatively and quantitatively. The multifaceted and systematically developed intervention will be the first of its kind and will provide a foundation for further refinement prior to formal efficacy testing.

Factors regulating the expression and function of calcium-independent cell adhesion molecules.

A combination of genetic and biochemical analysis is contributing to an understanding of the regulation and role of calcium-independent cell adhesion molecules. Recent progress ranges from the analysis of the control of promoter expression by homeobox genes to detailed analysis of the sites of homophilic and heterophilic interactions via mutagenesis strategies.

Cell adhesion molecules and neuronal regeneration.

Cell adhesion molecules (CAMs) are multifunctional proteins and are involved in a number of important regulatory processes in the brain, including cell growth, migration and regeneration. Recent studies using model in vitro systems have identified additional binding interactions in which CAMs, particularly those of the Ig superfamily, can participate. Signal transduction pathways are activated following CAM action in the process of neurite outgrowth. Key components in these pathways, such as kinases and phosphatases, are being identified. Receptor phosphatases themselves contain protein motifs characteristic of CAMs and may themselves be involved in adhesion-mediated cell recognition events.

Thymic lymphoproliferative disease after successful correction of CD40 ligand deficiency by gene transfer in mice.

Inherited deficiency of the CD40 ligand (X-linked hyper-IgM syndrome) is characterized by failure of immunoglobulin isotype switching and severe defects of cell-mediated immunity. To test the potential for gene transfer therapy to correct this disorder, we transduced murine bone marrow or thymic cells with a retroviral vector containing the cDNA for the murine CD40 ligand (CD40L) and injected them into CD40L-/- mice. Even low-level, constitutive expression of the transgene stimulated humoral and cellular immune functions in these mice. With extended follow-up, however, 12 of 19 treated mice developed T-lymphoproliferative disorders, ranging from polyclonal increases of lymphoblasts to overt monoclonal T-lymphoblastic lymphomas that involved multiple organs. Our findings show that constitutive (rather than tightly regulated), low-level expression of CD40L can produce abnormal proliferative responses in developing T lymphocytes, apparently through aberrant interaction between CD40L+ and TCRalphabeta+CD40+ thymocytes. Current methods of gene therapy may prove inappropriate for disorders involving highly regulated genes in essential positions in proliferative cascades.

Multiple interventions following an acute coronary syndrome event increase uptake into cardiac rehabilitation.

AIMS: Cardiac rehabilitation (CR) improves morbidity and mortality. Uptake varies for patients following acute coronary syndrome (ACS). Entry into CR is often dependent on the management strategy received, lower following percutaneous coronary intervention (PCI), higher following coronary artery bypass grafting (CABG). This study sought to investigate differences in CR uptake following an ACS event for those patients receiving multiple treatments. METHODS: Data was from the National Audit of CR between 2016 and 2019. Patients with ACS were categorised as: no intervention; one treatment (such as any PCI, CABG, any valve surgery and any device therapy); two treatments; or three or more treatments. Baseline demographics and logistic regression were used to analyse the effect of multiple treatment intervention on uptake into CR. RESULTS: A total of 6833 ACS patients were included in the analysis (0 treatments 2014, 1 treatment 3104, ≥2 treatments 2799). Patients who received ≥2 therapeutic interventions were more likely to be male, partnered and >2 comorbidities. Logistic regression showed a positive relationship between uptake total intervention. Similar associations were seen: being younger, male, partnered and having any comorbidity. The hospital stay, history of angina, diabetes and stroke was negatively correlated with an uptake. CONCLUSION: This study showed for the first time that multiple interventions following ACS is a significant predictor of uptake into CR. The findings align with recent trends with medically managed myocardial infarction uptake. Our findings identify factors associated with poor uptake to CR which should be considered as part of strategy to increase participation.

T cells that encounter virus in the complete absence of a particular H-2 antigen are nonresponsive when stimulated again in the context of that H-2 antigen.

Immunologically naive BALB/c (H-2d) and C57BL/6J (B6) (H-2b) T-cell populations can, after filtration to remove alloreactive precursor lymphocytes, be induced to respond to vaccinia virus presented in the context of H-2Kk when stimulated in an appropriate recipient. Exposure to vaccinia virus 6 wk previously completely abrogated the capacity of BALB/c T cells to interact with H-2Kk-vaccinia virus. This is also true for negatively selected B6 thoracic duct lymphocytes taken at 14 or 18 d, but not at 6 wk after immunization: the discrepancy is thought to reflect the progressive emergence of new T cells in the latter group. No evidence could be found for the operation of suppression, and the results are considered to indicate that T cells that interact with virus in the absence of the relevant H-2 antigen are tolerized. Whereas stimulation to effector function is H-2 restricted, induction of immune paralysis may be unrestricted. The capacity of T-cell populations to respond to virus presented in the context of allogeneic H-2 determinants thus depends upon previous antigenic experience.

Suppression of cell-mediated immunity by street rabies virus.

Mice lethally infected with street rabies virus failed to develop cytotoxic T cells specific for rabies virus-infected target cells, whereas high levels of cell-mediated cytotoxicity (CMC) were generated after nonfatal infection with the attenuated high egg passage (HEP) or ERA rabies virus strains. Furthermore concurrent infection with street, but not with HEP, rabies virus suppresses development of a primary (but not a secondary) CMC response specific for influenza virus. No cross-reactivity is found between effector T-cell populations from mice immunized with HEP or with influenza virus. It thus appears that street rabies virus, which is not known to replicate in the cells of immune system, induces some general defect in the primary CMC lymphocyte response, though restimulation of memory T-cell populations is unimpaired and there is no defect in antibody formation. Development of fatal rabies may reflect the operation of this selective immunosuppressive mechanism.

The control of specificity of cytotoxic T lymphocytes by the major histocompatibility complex (AG-B) in rats and identification of a new alloantigen system showing no AG-B restriction.

The regulatory influence of the rat major histocompatibility complex (MHC) (Ag-B complex) on the specificity of cytotoxic T lymphocytes was investigated. It was shown that the effector cells were specific for the original Ag-B phenotype in rat systems in which the responder and stimulator cell populations were unquestionably MHC identical but expressed different minor alloantigens of viral antigens. However, combined in vivo immunization and restimulation in culture of lymphocytes from rat strains previously thought to be MHC compatible resulted in the generation of cytotoxic T lymphocytes which effectively lyse not only target cells from the specific stimulating strains but also, to varying degrees, target cells from third party strains regardless of their Ag-B haplotypes. Genetic analysis indicates that expression of these cytotoxic T-cell-defined ("CT") antigens, found on both T and B lymphocytes, detectable thus far only with cytotoxic lymphocytes, is controlled by a single locus which segregates in backcross populations with the rat MHC. Discrepancies between the nature of CT antigens of the rat Ag-B and I-region specificities of the mouse H-2 are discussed.

T-cell populations specifically depleted of alloreactive potential cannot be induced to lyse H-2-different virus-infected target cells.

Mouse lymphocyte populations of one parental H-2 type (A) were specificially depleted of alloreactive potential by filtration through irradiated A X B F1 recipients, and thoracic duct cells were then stimulated with virus in an A X B F1 environment. Experiments using T cells that had previously been exposed to influenza virus in the context of A established that cross-priming for recognition of viral components expressed on H-2-different (B) target cells does not occur. Furthermore, immunologically naive T cells stimulated with vaccinia virus, subsequent to negative selection for reactivity to B, could not be shown to interact with virus-infected cells of type B. Either there is no significant T-cell repertoire for recognition of virus associated with an H-2 determinant not encountered during ontogeny, or such T cells are also alloreactive and are removed during filtration.

H-2 compatibility is required for T-cell-mediated lysis of target cells infected with lymphocytic choriomeningitis virus.

Maximal cell-mediated lysis of targets infected with lymphocytic choriomeningitis virus occurs only within a H-2 compatible system. Syngeneic immune spleen cells are at least 100 times as effective as are allogeneic lymphocytes. Reciprocal restriction of cytotoxic T-cell activity has been shown to operative between H-2k, H-2d, and H-2b. Experiments with cogenic mice have localized the effect to the H-2 gene complex. Furthermore, the observation that lymphocytes from H-2a mice cause high specific 51Cr release from either H-2d virus-infected cells, indicates that identity at either the K or the D end of the H-2 gene complex is sufficient for this lytic interaction.

H-2 compatability requirement for T-cell-mediated lysis of target cells infected with lymphocytic choriomeningitis virus. Different cytotoxic T-cell specificities are associated with structures coded for in H-2K or H-2D;.

Use of syngeneic, allogeneic, F1, AND H-2 recombinatn mice has shown that animals injected with lymphocytic choriomeningitis (LCM) virus generate T cells which are cytotoxic for H-2K or H-2D compatible, but not H-2 different, virus-infected target cells. Three separate lines of evidence are presented which indicate that these immune T cells are sensitized to "altered-self," the self antigens involved being coded for in the H-2K or H-2d regions. Firstly, cytotoxic activity associated with mutuality at H-2D iy, lysis mediated by immune T cells from F1 or H-2 recombinant mice is specifically inhibited only by presence of unlabeled, virus-infected cells that are H-2 compatible with the targets. Thirdly, LCM-immune F1 and H-2 recombinant T cells inoculated into irradiated, virus-infected recipients proliferate only to kill target cells that are H-2 compatible with both the donor and the recipient. All of these experiments establish that there is a dissociation of T-cell activities between parental haplotypes in F1 mice, and between H-2K and H-2D in recombinants. It would thus seem that there are at least two specificities of tlcm-immune T cells in homozygotes, associated with either H-2K or H-2D, and four specificities in F1 hybrids. The significance of these findings, with respect both to gene duplication and to the marked polymorphism in the H-2 system, is discussed.

Induction of neonatal tolerance to H-2k in B6 mice does not allow the emergence of T cells specific for H-2k plus vaccinia virus.

Thymocytes and spleen cells from C57BL/6 mice (H-2b) neonatally tolerized to H-2k alloantigens do not generate an anti-vaccinia response restricted to H-2Kk when adoptively transferred to appropriate irradiated hosts. This is in sharp contrast to the case for negatively selected C57BL/6 spleen cells acutely depleted of alloreactivity. No evidence for suppression was found in cell mixture experiments. We have shown elsewhere that our neonatally tolerized animals have a centrally induced delection-type tolerance in the absence of obvious suppression.2 We now suggest that in the neonatally tolerized mouse, chronic, central delection of anti-H-2k clones during early T cell ontogeny eliminates the major source of cells able to give rise, via somatic mutation and expansion, to anti-H-2Kk + vaccinia specific cytotoxic T lymphocyte precursors (CTL-P) in the adult. A similar mechanism may operate in the (k + b) leads to b chimera; however, the presence of H-2kxb accessory and presenting cells may permit the eventual generation (via cross-stimulation) of an H-2k-restricted vaccinia-specific repertoire. This would account for our observation of such "aberrant recognition" CTL-P emerging in the spleens of older (k x b) leads to b chimeras.

Vaccinia-specific cytotoxic T-cell responses in the context of H-2 antigens not encountered in thymus may reflect aberrant recognition of a virus-H-2 complex.

BALB/c (H-2Kd-Dd) spleen and lymph node populations were specifically depleted of alloreactive potential by filtration through H-2 different, irradiated recipients. These negatively selected T cells were then stimulated with vaccinia virus in mice expressing the foreign H-2 determinants encountered previously in the filter environment. Strong virus-immune cytotoxic T-cell responses were seen in the context of H-2Kk and H-2Ks, but not 2H-2Kb. The T cells generated were not cross-reactive for the H-2Kk and H-2Kd alleles, and responsiveness was independent of concurrent presence of effector populations operating at H-2D. These findings are consisent with the idea that recognition is mediated via a complex receptor, part of which is specific for virus and part for self H-2. The capacity to interact with allogeneic, virus-infected cells may then reflect aberrant recognition of a virus-H-2-antigen complex by this single, large binding site. For instance, the T cell which would normally recognize H-2Kd-virus x, or H-2Dd-minor histocompatibility antigen Z, may now show specificity for H-2Kk-vaccinia virus. Implications for both the selective role of the thymus and for mechanisms of tolerance are discussed.

Patterns of virus-immune T-cell responsiveness. Comparison of (H-2k X H-2b) leads to H-2b radiation chimeras and negatively selected H-2b lymphocytes.

Negatively selected H-2K(b)D(b) TDL can be induced to respond strongly to vaccinia virus presented in the context of both H-2K(k) and H-2D(b) when stimulated in irradiated H-2K(k)D(b) recipients. Addition of excess (H- 2K(k)D(b) x H-2K(b)D(b))F1 TDL, which are low responders to H-2D(b)-vaccinia virus, does not obviously suppress the reactivity pattern of the H-2K(b)D(b) T cells. However, lymphocytes from chimeras made by reconstituting H- 2K(b)D(b) mice with (H-2K(k)D(k) x H-2K(b)D(b))F(l) bone marrow cells make little, if any, cytotoxic T-cell response to vaccinia virus when sensitized in H-2K(k)D(b) recipients. We have thus documented one instance where the responder phenotype of T ceils from an F(l) {arrow} parent chimera is not equivalent to that associated with the H-2 type of the parental thymus. Lymphocytes from both the chimera and the H-2K(b)D(b) parent (after negative selection) are tolerant to the H-2K(k) and I-A(k) alloantigens encountered in the recipient, but the chimera T cells are also defective in their response to a neoantigen (vaccinia virus) presented in the context of H-2K(k) which the parental T cells invariably recognize. It is thus possible that at least part of the phenomenology associated with the F(l) {arrow} parent radiation chimeras reflects deletion of repertoire in the context of H-2 antigens present during thymocyte ontogeny on other than radiation-resistant thymic epithelium.

Clearance of influenza virus respiratory infection in mice lacking class I major histocompatibility complex-restricted CD8+ T cells.

Transgenic mice homozygous for a beta 2-microglobulin (beta 2-m) gene disruption and normal mice that had been treated with a CD8-specific mAb were infected intranasally with an H3N2 influenza A virus. Both groups of CD8T cell-deficient mice eliminated the virus from the infected respiratory tract. Potent CTL activity was detected in lung lavage populations taken from mice with intact CD8+ T cell function, with minimal levels of cytotoxicity being found for inflammatory cells obtained from the antibody-treated and beta 2-m mutant mice. We therefore conclude that cells infected with an influenza A virus can be cleared from the respiratory tract of mice lacking both functional class I major histocompatibility complex (MHC) glycoproteins and class I MHC-restricted, CD8+ effector T cells.

Generation of both cross-reactive and virus-specific T-cell populations after immunization with serologically distinct influenza A viruses.

Specificity of cytotoxic T-cell function was investigated for a range of different influenza viruses. T cells from mice immunized with A or B strain influenza viruses, or with vaccinia virus, showed reciprocal exclusion of cytotoxicity. Extensive cross-reactivity was, however, found for lymphocyte populations from mice infected with a variety of serologically distinct influenza A viruses, though serum antibodies did not cross-react when tested in a radioimmunoassay using comparable target cells as immunoadsorbents. This apparent lack of T-cell specificity was recognized for immune spleen cells generated after intraperitoneal inoculation of high titers of virus, and for mediastinal lymph node populations from mice with pneumonia due to infection with much less virus. The phenomenon could not be explained on the basis of exposure to the chicken host component, which is common to A and B strain viruses. However, not all of the virus-immune T-cell clones are cross-reactive. Competitive-inhibition experiments indicate that a considerable proportion of the lymphocyte response is restricted to the immunizing virus. Even so, the less specific component is significant. Also, exposure to one type A virus was found to prime for an enhanced cell-mediated immunity response after challenge with a second, serologically different A strain virus.