Acceptance and Commitment Therapy plus usual care for improving quality of life in people with motor neuron disease (COMMEND): a multicentre, parallel, randomised controlled trial in the UK

BACKGROUND

Motor neuron disease is a progressive, fatal neurodegenerative disease for which there is no cure. Acceptance and Commitment Therapy (ACT) is a psychological therapy incorporating acceptance, mindfulness, and behaviour change techniques. We aimed to evaluate the effectiveness of ACT plus usual care, compared with usual care alone, for improving quality of life in people with motor neuron disease.

METHODS

We conducted a parallel, multicentre, two-arm randomised controlled trial in 16 UK motor neuron disease care centres or clinics. Eligible participants were aged 18 years or older with a diagnosis of definite or laboratory-supported probable, clinically probable, or possible familial or sporadic amyotrophic lateral sclerosis; progressive muscular atrophy; or primary lateral sclerosis; which met the World Federation of Neurology's El Escorial diagnostic criteria. Participants were randomly assigned (1:1) to receive up to eight sessions of ACT adapted for people with motor neuron disease plus usual care or usual care alone by a web-based system, stratified by site. Participants were followed up at 6 months and 9 months post-randomisation. Outcome assessors and trial statisticians were masked to treatment allocation. The primary outcome was quality of life using the McGill Quality of Life Questionnaire-Revised (MQOL-R) at 6 months post-randomisation. Primary analyses were multi-level modelling and modified intention to treat among participants with available data. This trial was pre-registered with the ISRCTN Registry (ISRCTN12655391).

FINDINGS

Between Sept 18, 2019, and Aug 31, 2022, 435 people with motor neuron disease were approached for the study, of whom 206 (47%) were assessed for eligibility, and 191 were recruited. 97 (51%) participants were randomly assigned to ACT plus usual care and 94 (49%) were assigned to usual care alone. 80 (42%) of 191 participants were female and 111 (58%) were male, and the mean age was 63·1 years (SD 11·0). 155 (81%) participants had primary outcome data at 6 months post-randomisation. After controlling for baseline scores, age, sex, and therapist clustering, ACT plus usual care was superior to usual care alone for quality of life at 6 months (adjusted mean difference on the MQOL-R of 0·66 [95% CI 0·22-1·10]; d=0·46 [0·16-0·77]; p=0·0031). Moderate effect sizes were clinically meaningful. 75 adverse events were reported, 38 of which were serious, but no adverse events were deemed to be associated with the intervention.

INTERPRETATION

ACT plus usual care is clinically effective for maintaining or improving quality of life in people with motor neuron disease. As further evidence emerges confirming these findings, health-care providers should consider how access to ACT, adapted for the specific needs of people with motor neuron disease, could be provided within motor neuron disease clinical services.

FUNDING

National Institute for Health and Care Research Health Technology Assessment and Motor Neurone Disease Association.

Cost-effectiveness of acceptance and commitment therapy for people living with motor neuron disease, and their health-related quality of life

BACKGROUND

Given the degenerative nature of the condition, people living with motor neuron disease (MND) experience high levels of psychological distress. The purpose of this research was to investigate the cost-effectiveness of acceptance and commitment therapy (ACT), adapted for the specific needs of this population, for improving quality of life.

METHODS

A trial-based cost-utility analysis over a 9-month period was conducted comparing ACT plus usual care (n = 97) versus usual care alone (n = 94) from the perspective of the National Health Service. In the primary analysis, quality-adjusted life years (QALYs) were computed using health utilities generated from the EQ-5D-5L questionnaire. Sensitivity analyses and subgroup analyses were also carried out.

RESULTS

Difference in costs was statistically significant between the two arms, driven mainly by the intervention costs. Effects measured by EQ-5D-5L were not statistically significantly different between the two arms. The incremental cost-effectiveness was above the £20,000 to £30,000 per QALY gained threshold used in the UK. However, the difference in effects was statistically significant when measured by the McGill Quality of Life-Revised (MQOL-R) questionnaire. The intervention was cost-effective in a subgroup experiencing medium deterioration in motor neuron symptoms.

CONCLUSIONS

Despite the intervention being cost-ineffective in the primary analysis, the significant difference in the effects measured by MQOL-R, the low costs of the intervention, the results in the subgroup analysis, and the fact that ACT was shown to improve the quality of life for people living with MND, suggest that ACT could be incorporated into MND clinical services.

Formation of a conceptual framework during the development of a patient-reported outcome measure for early gastrointestinal recovery: phase I of the PRO-diGi study

AIM

Patients admitted to hospital for abdominal surgery often experience gastrointestinal dysfunction. Many studies have reported outcomes following gastrointestinal dysfunction, yet there is no unified definition of recovery or a validated patient-reported outcome measure (PROM). The first stage of PROM development requires formation of a conceptual framework to identify key themes to patients. The aim of this study was to utilize semistructured interviews to identify core themes and concepts relevant to patients to facilitate development of a conceptual framework.

METHOD

Adult patients admitted to hospital for major gastrointestinal, urological or gynaecological surgery, in an emergency or elective setting, were eligible to participate. Patients treated nonoperatively for small bowel obstruction were also eligible. Interviews were conducted by telephone, audio-recorded, transcribed, coded and analysed using NVivo software by two researchers and reviewed by lay members of the steering group. Interviews continued until data saturation was reached. Ethical approval was gained prior to interviews (21/WA/0231).

RESULTS

Twenty nine interviews were completed (17 men, median age 64 years) across three specialties (20 gastrointestinal, six gynaecological, three urological). Two overarching themes of 'general recovery' and 'gastrointestinal symptoms' were identified. General recovery included three themes: 'life impact', 'mental impact', including anxiety, and 'physical impact', including fatigue. Gastrointestinal symptoms included three themes: 'abdominal symptoms' such as pain, 'diet and appetite' and 'expulsory function', such as stool frequency. A total of 18 gastrointestinal symptoms were identified during patient recovery-many of which lasted several weeks following discharge.

CONCLUSION

This study reports a range of gastrointestinal and nongastrointestinal symptoms experienced by patients during early gastrointestinal recovery. Identified symptoms have been synthesized into a conceptual framework to enable development of a definitive PROM for early gastrointestinal recovery.

A randomised controlled trial of acceptance and commitment therapy plus usual care compared to usual care alone for improving psychological health in people with motor neuron disease (COMMEND): study protocol

BACKGROUND

Motor neuron disease (MND) is a rapidly progressive, fatal neurodegenerative disease that predominantly affects motor neurons from the motor cortex to the spinal cord and causes progressive wasting and weakening of bulbar, limb, abdominal and thoracic muscles. Prognosis is poor and median survival is 2-3 years following symptom onset. Psychological distress is relatively common in people living with MND. However, formal psychotherapy is not routinely part of standard care within MND Care Centres/clinics in the UK, and clear evidence-based guidance on improving the psychological health of people living with MND is lacking. Previous research suggests that Acceptance and Commitment Therapy (ACT) may be particularly suitable for people living with MND and may help improve their psychological health.

AIMS

To assess the clinical and cost-effectiveness of ACT modified for MND plus usual multidisciplinary care (UC) in comparison to UC alone for improving psychological health in people living with MND.

METHODS

The COMMEND trial is a multi-centre, assessor-blind, parallel, two-arm RCT with a 10-month internal pilot phase. 188 individuals aged ≥ 18 years with a diagnosis of definite, laboratory-supported probable, clinically probable, or possible familial or sporadic amyotrophic lateral sclerosis, and additionally the progressive muscular atrophy and primary lateral sclerosis variants, will be recruited from approximately 14 UK-based MND Care Centres/clinics and via self-referral. Participants will be randomly allocated to receive up to eight 1:1 sessions of ACT plus UC or UC alone by an online randomisation system. Participants will complete outcome measures at baseline and at 6- and 9-months post-randomisation. The primary outcome will be quality of life at six months. Secondary outcomes will include depression, anxiety, psychological flexibility, health-related quality of life, adverse events, ALS functioning, survival at nine months, satisfaction with therapy, resource use and quality-adjusted life years. Primary analyses will be by intention to treat and data will be analysed using multi-level modelling.

DISCUSSION

This trial will provide definitive evidence on the clinical and cost-effectiveness of ACT plus UC in comparison to UC alone for improving psychological health in people living with MND.

TRIAL REGISTRATION

ISRCTN Registry, ISRCTN12655391. Registered 17 July 2017, https://www.isrctn.com/ISRCTN12655391 .

PROTOCOL VERSION

3.1 (10/06/2020).

Life-threatening viral disease in a novel form of autosomal recessive IFNAR2 deficiency in the Arctic

Type I interferons (IFN-I) play a critical role in human antiviral immunity, as demonstrated by the exceptionally rare deleterious variants of IFNAR1 or IFNAR2. We investigated five children from Greenland, Canada, and Alaska presenting with viral diseases, including life-threatening COVID-19 or influenza, in addition to meningoencephalitis and/or hemophagocytic lymphohistiocytosis following live-attenuated viral vaccination. The affected individuals bore the same homozygous IFNAR2 c.157T>C, p.Ser53Pro missense variant. Although absent from reference databases, p.Ser53Pro occurred with a minor allele frequency of 0.034 in their Inuit ancestry. The serine to proline substitution prevented cell surface expression of IFNAR2 protein, small amounts of which persisted intracellularly in an aberrantly glycosylated state. Cells exclusively expressing the p.Ser53Pro variant lacked responses to recombinant IFN-I and displayed heightened vulnerability to multiple viruses in vitro-a phenotype rescued by wild-type IFNAR2 complementation. This novel form of autosomal recessive IFNAR2 deficiency reinforces the essential role of IFN-I in viral immunity. Further studies are warranted to assess the need for population screening.

An intervention to promote self-management, independence and self-efficacy in people with early-stage dementia: the Journeying through Dementia RCT

BACKGROUND

There are few effective interventions for dementia.

AIM

To determine the clinical effectiveness and cost-effectiveness of an intervention to promote self-management, independence and self-efficacy in people with early-stage dementia.

OBJECTIVES

To undertake a randomised controlled trial of the Journeying through Dementia intervention compared with usual care, conduct an internal pilot testing feasibility, assess intervention delivery fidelity and undertake a qualitative exploration of participants' experiences.

DESIGN

A pragmatic two-arm individually randomised trial analysed by intention to treat.

PARTICIPANTS

A total of 480 people diagnosed with mild dementia, with capacity to make informed decisions, living in the community and not participating in other studies, and 350 supporters whom they identified, from 13 locations in England, took part.

INTERVENTION

Those randomised to the Journeying through Dementia intervention (n = 241) were invited to take part in 12 weekly facilitated groups and four one-to-one sessions delivered in the community by secondary care staff, in addition to their usual care. The control group (n = 239) received usual care. Usual care included drug treatment, needs assessment and referral to appropriate services. Usual care at each site was recorded.

MAIN OUTCOME MEASURES

The primary outcome was Dementia-Related Quality of Life score at 8 months post randomisation, with higher scores representing higher quality of life. Secondary outcomes included resource use, psychological well-being, self-management, instrumental activities of daily living and health-related quality of life.

RANDOMISATION AND BLINDING

Participants were randomised in a 1 : 1 ratio. Staff conducting outcome assessments were blinded.

DATA SOURCES

Outcome measures were administered in participants' homes at baseline and at 8 and 12 months post randomisation. Interviews were conducted with participants, participating carers and interventionalists.

RESULTS

The mean Dementia-Related Quality of Life score at 8 months was 93.3 (standard deviation 13.0) in the intervention arm (n = 191) and 91.9 (standard deviation 14.6) in the control arm (n = 197), with a difference in means of 0.9 (95% confidence interval -1.2 to 3.0; p = 0.380) after adjustment for covariates. This effect size (0.9) was less than the 4 points defined as clinically meaningful. For other outcomes, a difference was found only for Diener's Flourishing Scale (adjusted mean difference 1.2, 95% confidence interval 0.1 to 2.3), in favour of the intervention (i.e. in a positive direction). The Journeying through Dementia intervention cost £608 more than usual care (95% confidence interval £105 to £1179) and had negligible difference in quality-adjusted life-years (-0.003, 95% confidence interval -0.044 to 0.038). Therefore, the Journeying through Dementia intervention had a mean incremental cost per quality-adjusted life-year of -£202,857 (95% confidence interval -£534,733 to £483,739); however, there is considerable uncertainty around this. Assessed fidelity was good. Interviewed participants described receiving some benefit and a minority benefited greatly. However, negative aspects were also raised by a minority. Seventeen per cent of participants in the intervention arm and 15% of participants in the control arm experienced at least one serious adverse event. None of the serious adverse events were classified as related to the intervention.

LIMITATIONS

Study limitations include recruitment of an active population, delivery challenges and limitations of existing outcome measures.

CONCLUSIONS

The Journeying through Dementia programme is not clinically effective, is unlikely to be cost-effective and cannot be recommended in its existing format.

FUTURE WORK

Research should focus on the creation of new outcome measures to assess well-being in dementia and on using elements of the intervention, such as enabling enactment in the community.

TRIAL REGISTRATION

This trial is registered as ISRCTN17993825.

FUNDING

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 26, No. 24. See the NIHR Journals Library website for further project information.

The Journeying through Dementia psychosocial intervention versus usual care study: a single-blind, parallel group, phase 3 trial

BACKGROUND

There is an urgent clinical need for evidence-based psychosocial interventions for people with mild dementia. We aimed to determine the clinical benefits and cost-effectiveness of Journeying through Dementia (JtD), an intervention designed to promote wellbeing and independence in people with mild dementia.

METHODS

We did a single-blind, parallel group, individually randomised, phase 3 trial at 13 National Health Service sites across England. People with mild dementia (Mini-Mental State Examination score of ≥18) who lived in the community were eligible for inclusion. Patients were centrally randomly assigned (1:1) to receive the JtD intervention plus standard care (JtD group) or standard care only (standard care group). Randomisation was stratified by study site. The JtD intervention included 12 group and four one-to-one sessions, delivered in the community at each site. The primary endpoint was Dementia Related Quality of Life (DEMQOL) 8 months after randomisation, assessed according to the intention-to-treat principle. Only outcome assessors were masked to group assignment. A cost-effectiveness analysis reported cost per quality-adjusted life-year (QALY) from a UK NHS and social care perspective. The study is registered with ISRCTN, ISRCTN17993825.

FINDINGS

Between Nov 30, 2016, and Aug 31, 2018, 1183 patients were screened for inclusion, of whom 480 (41%) participants were randomly assigned: 241 (50%) to the JtD group and 239 (50%) to the standard care group. Intervention adherence was very good: 165 (68%) of 241 participants in the JtD group attended at least ten of the 16 sessions. Mean DEMQOL scores at 8 months were 93·3 (SD 13·0) for the JtD group and 91·9 (SD 14·6) for the control group. Difference in means was 0·9 (95% CI -1·2 to 3·0; p=0·38) after adjustment for covariates, lower than that identified as clinically meaningful. Incremental cost per QALY ranged from £88 000 to -£205 000, suggesting that JtD was not cost-effective. Unrelated serious adverse events were reported by 40 (17%) patients in the JtD group and 35 (15%) patients in the standard care group.

INTERPRETATION

In common with other studies, the JtD intervention was not proven effective. However, this complex trial successfully recruited and retained people with dementia without necessarily involving carers. Additionally, people with dementia were actively involved as participants and study advisers throughout. More research into methods of measuring small, meaningful changes in this population is needed. Questions remain regarding how services can match the complex, diverse, and individual needs of people with mild dementia, and how interventions to meet such needs can be delivered at scale.

FUNDING

UK National Institute of Health Research Health Technology Assessment Programme.

Delayed induction of type I and III interferons mediates nasal epithelial cell permissiveness to SARS-CoV-2

The nasal epithelium is a plausible entry point for SARS-CoV-2, a site of pathogenesis and transmission, and may initiate the host response to SARS-CoV-2. Antiviral interferon (IFN) responses are critical to outcome of SARS-CoV-2. Yet little is known about the interaction between SARS-CoV-2 and innate immunity in this tissue. Here we apply single-cell RNA sequencing and proteomics to a primary cell model of human nasal epithelium differentiated at air-liquid interface. SARS-CoV-2 demonstrates widespread tropism for nasal epithelial cell types. The host response is dominated by type I and III IFNs and interferon-stimulated gene products. This response is notably delayed in onset relative to viral gene expression and compared to other respiratory viruses. Nevertheless, once established, the paracrine IFN response begins to impact on SARS-CoV-2 replication. When provided prior to infection, recombinant IFNβ or IFNλ1 induces an efficient antiviral state that potently restricts SARS-CoV-2 viral replication, preserving epithelial barrier integrity. These data imply that the IFN-I/III response to SARS-CoV-2 initiates in the nasal airway and suggest nasal delivery of recombinant IFNs to be a potential chemoprophylactic strategy.

DYRK1A regulates B cell acute lymphoblastic leukemia through phosphorylation of FOXO1 and STAT3

DYRK1A is a serine/threonine kinase encoded on human chromosome 21 (HSA21) that has been implicated in several pathologies of Down syndrome (DS), including cognitive deficits and Alzheimer's disease. Although children with DS are predisposed to developing leukemia, especially B cell acute lymphoblastic leukemia (B-ALL), the HSA21 genes that contribute to malignancies remain largely undefined. Here, we report that DYRK1A is overexpressed and required for B-ALL. Genetic and pharmacologic inhibition of DYRK1A decreased leukemic cell expansion and suppressed B-ALL development in vitro and in vivo. Furthermore, we found that FOXO1 and STAT3, transcription factors that are indispensable for B cell development, are critical substrates of DYRK1A. Loss of DYRK1A-mediated FOXO1 and STAT3 signaling disrupted DNA damage and ROS regulation, respectively, leading to preferential cell death in leukemic B cells. Thus, we reveal a DYRK1A/FOXO1/STAT3 axis that facilitates the development and maintenance of B-ALL.

Severe type I interferonopathy and unrestrained interferon signaling due to a homozygous germline mutation in STAT2

Excessive type I interferon (IFNα/β) activity is implicated in a spectrum of human disease, yet its direct role remains to be conclusively proven. We investigated two siblings with severe early-onset autoinflammatory disease and an elevated IFN signature. Whole-exome sequencing revealed a shared homozygous missense Arg148Trp variant in STAT2, a transcription factor that functions exclusively downstream of innate IFNs. Cells bearing STAT2^R148W in homozygosity (but not heterozygosity) were hypersensitive to IFNα/β, which manifest as prolonged Janus kinase-signal transducers and activators of transcription (STAT) signaling and transcriptional activation. We show that this gain of IFN activity results from the failure of mutant STAT2^R148W to interact with ubiquitin-specific protease 18, a key STAT2-dependent negative regulator of IFNα/β signaling. These observations reveal an essential in vivo function of STAT2 in the regulation of human IFNα/β signaling, providing concrete evidence of the serious pathological consequences of unrestrained IFNα/β activity and supporting efforts to target this pathway therapeutically in IFN-associated disease.

Abstract A81: Hyaluronan-dependent skewing of tumor-associated macrophage (TAM) phenotype in a murine pancreatic tumor model is associated with increased tumor hypoxia

Hyaluronan (HA) is a naturally occurring glycosaminoglycan that accumulates in the tumor microenvironment of several cancer types, including pancreatic ductal adenocarcinoma (PDA), where it is an independent negative predictor of survival. An ongoing phase 3 study is evaluating pegvorhyaluronidase alfa (PEGPH20; PVHA), a first-in-class biologic that enzymatically degrades HA in the tumor microenvironment, in combination with gemcitabine and nab-paclitaxel in metastatic PDA. Recently, we reported that HA-accumulation can promote tumor hypoxia; however, the effects this may have on tumor-infiltrating immune cells are unknown. Transduction of syngeneic murine PDA cells (Pan02) with hyaluronan synthase 3 (HAS3) generates tumors (Pan02-HAS3) containing high levels of HA, and a higher frequency of TAMs with an immunosuppressive phenotype (CD206-high MHCII-low), relative to tumors generated by empty vector-transduced cells (Pan02-EV). Given the association of this TAM phenotype with tumor hypoxia, we assessed the relationship between tumor hypoxia and the TAM phenotypes of Pan02-HAS3 and Pan02-EV tumors. To confirm whether the effects seen in Pan02-HAS3 tumors require HA synthesis, we also generated tumors expressing an enzymatically inactive HAS3 mutant (Pan02-HAS3 D215A). Tumor-bearing mice were injected with pimonidazole hydrochloride 2 hours prior to harvest and dissociation of tumor tissue; subsequent flow cytometric analysis of tumor-infiltrating immune cells included an antibody against pimonidazole hydrochloride adducts (HP-1) to detect cells residing in hypoxic zones. A greater mean percentage of TAMs isolated from Pan02-HAS3 peritibial tumors had high levels of HP-1 staining (HP-1+) compared with TAMs isolated from either Pan02-EV or Pan02-HAS3 D215A tumors (18.2%, 4.2% and 3.9%, respectively). Furthermore, HP-1+ cells were enriched among CD206-high MHCII-low TAMs compared with their MHCII-high counterparts in Pan02-HAS3 tumors (38.7% vs 11.9%). Likewise, more HP-1+ cells were seen among dendritic cells (DCs) isolated from Pan02-HAS3 tumors compared with either Pan02-EV or Pan02-HAS3 D215A tumors (6.9%, 1.3% and 0.8%, respectively). Similar findings were obtained in orthotopic tumors. In contrast, no consistent differences in the percentages of HP-1+ CD8 T cells or NK cells were observed across the three tumor types in this study. Finally, exposure of cultured macrophages to hypoxia recapitulated some of the changes in gene expression observed in TAMs sorted from Pan02-HAS3 tumors, including increased expression of Arg1 and Nos2. These data suggest that tumor HA accumulation may promote an immunosuppressive TAM phenotype by creating tumor hypoxic zones that are subsequently infiltrated by TAMs, but not T or NK cells.

Citation Format: Trevor Kimbler, Jessica Cowell, Jisook Lee, Benjamin J. Thompson. Hyaluronan-dependent skewing of tumor-associated macrophage (TAM) phenotype in a murine pancreatic tumor model is associated with increased tumor hypoxia [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr A81.

The cytoskeletal motor proteins Dynein and MyoV direct apical transport of Crumbs

Crumbs (Crb in Drosophila; CRB1-3 in mammals) is a transmembrane determinant of epithelial cell polarity and a regulator of Hippo signalling. Crb is normally localized to apical cell-cell contacts, just above adherens junctions, but how apical trafficking of Crb is regulated in epithelial cells remains unclear. We use the Drosophila follicular epithelium to demonstrate that polarized trafficking of Crb is mediated by transport along microtubules by the motor protein Dynein and along actin filaments by the motor protein Myosin-V (MyoV). Blocking transport of Crb-containing vesicles by Dynein or MyoV leads to accumulation of Crb within Rab11 endosomes, rather than apical delivery. The final steps of Crb delivery and stabilisation at the plasma membrane requires the exocyst complex and three apical FERM domain proteins - Merlin, Moesin and Expanded - whose simultaneous loss disrupts apical localization of Crb. Accordingly, a knock-in deletion of the Crb FERM-binding motif (FBM) also impairs apical localization. Finally, overexpression of Crb challenges this system, creating a sensitized background to identify components involved in cytoskeletal polarization, apical membrane trafficking and stabilisation of Crb at the apical domain.

Integrated Metabolomic and Transcriptomic Analysis to Characterize Cutin Biosynthesis between Low- and High-Cutin Genotypes of Capsicum chinense Jacq

Habanero peppers constantly face biotic and abiotic stresses such as pathogen/pest infections, extreme temperature, drought and UV radiation. In addition, the fruit cutin lipid composition plays an important role in post-harvest water loss rates, which in turn causes shriveling and reduced fruit quality and storage. In this study, we integrated metabolome and transcriptome profiling pertaining to cutin in two habanero genotypes: PI 224448 and PI 257145. The fruits were selected by the waxy or glossy phenotype on their surfaces. Metabolomics analysis showed a significant variation in cutin composition, with about 6-fold higher cutin in PI 257145 than PI 224448. It also revealed that 10,16-dihydroxy hexadecanoic acid is the most abundant monomer in PI 257145. Transcriptomic analysis of high-cutin PI 257145 and low-cutin PI 224448 resulted in the identification of 2703 statistically significant differentially expressed genes, including 1693 genes upregulated and 1010 downregulated in high-cutin PI 257145. Genes and transcription factors such as GDSL lipase, glycerol-3 phosphate acyltransferase 6, long-chain acyltransferase 2, cytochrome P450 86A/77A, SHN1, ANL2 and HDG1 highly contributed to the high cutin content in PI 257145. We predicted a putative cutin biosynthetic pathway for habanero peppers based on deep transcriptome analysis. This is the first study of the transcriptome and metabolome pertaining to cutin in habanero peppers. These analyses improve our knowledge of the molecular mechanisms regulating the accumulation of cutin in habanero pepper fruits. These resources can be built on for developing cultivars with high cutin content that show resistance to biotic and abiotic stresses with superior postharvest appearance.

The growth of a xenograft breast cancer tumor model with engineered hyaluronan-accumulating stroma is dependent on hyaluronan and independent of CD44

Hyaluronan accumulation in the tumor microenvironment is associated with poor prognosis in several solid human cancers. To understand the role of stromal hyaluronan in tumor progression, we engineered 3T3HAS3, a hyaluronan-producing fibroblast cell line, by lentiviral transduction of Balb/c 3T3 cells with the human hyaluronan synthase 3(HAS3) gene. 3T3HAS3 cells significantly enhanced tumor growth when co-grafted with MDA-MB-468 cells in nude mice. Immunohistochemical analysis of the xenograft tumors showed that MDA-MB-468 cells were surrounded by hyaluronan-accumulating stroma, closely resembling the morphology observed in human breast cancer specimens. Tumor growth of MDA-MB-468 + 3T3HAS3 co-grafts was greatly reduced upon hyaluronan degradation by lentiviral transduction of a human hyaluronidase gene in 3T3HAS3 cells, or by systemic administration of pegvorhyaluronidase alfa (PEGPH20). In contrast, the growth of the co-graft tumors was not inhibited when CD44 expression was reduced or ablated by small hairpin RNA-mediated CD44 knockdown in MDA-MB-468 cells, CD44 CRISPR knockout in 3T3HAS3 cells, or by grafting these cells in CD44 knockout nude mice. Collectively, these data demonstrate that tumor growth of an engineered xenograft breast cancer model with hyaluronan-accumulating stroma can be dependent on hyaluronan and independent of CD44.

A focus group study exploring student nurse's experiences of an educational intervention focused on working with people with a diagnosis of personality disorder

WHAT IS KNOWN ON THE SUBJECT?: Research has consistently shown that poor attitudes exist in mental health care towards people with a diagnosis of personality disorder and that nurses can find working with this group of patients professionally and personally challenging. Power imbalances of practitioner over students exist on training placements. This can result in students being exposed to negative attitudes towards service users with a diagnosis of personality disorder and not feeling able to challenge these attitudes. The Knowledge and Understanding Framework (KUF) is a specialist programme of personality disorder training that has demonstrated effectiveness with qualified mental health professionals. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: Although the subject of personality disorder is considered within preregistration education, an opportunity for a more robust approach to supporting student's nurses with this complex subject area is required (Ross & Goldner 2018). Attempts to integrate and evaluate specific educational interventions of this nature into preregistration nurse education have not been explored elsewhere. This study utilized focus groups to examine the experience of the KUF training and the perceived impact on attitudes and approaches to personality disorder of a group of nursing students who had completed the KUF programme. The students exhibited positive attitudes towards people with a diagnosis of personality disorder and confidence to influence negative attitudes in practice. The KUF shifted the students' focus from identifying patient behaviours as problematic towards an understanding of these difficulties arising from their own emotional responses. This was a small study so the results should be treated with caution. There was no follow-up once the students had qualified, so it is not clear whether such effects would endure long term. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Training students using the KUF may foster positive attitudes to people with a diagnosis of personality disorder and provide them with the skills to positively influence other colleagues practice.

ABSTRACT

Introduction Negative attitudes exist in practice towards those with a diagnosis of personality disorder. Preregistration training offers the opportunity to address this by developing understanding of the diagnosis, confidence in working with people with the diagnosis and empowering new nurses to challenge prevailing attitudes. Attempts to integrate and evaluate specific educational interventions of this nature into preregistration nurse education have not been explored elsewhere. Aim To explore preregistration, nurses' experience of a programme of training focused on personality disorder and their perception of its influence on attitudes, understanding of clients and their experience of practice. Method A qualitative study using thematic analysis of two focus groups of preregistration mental health nursing students. Results Evidence of positive attitudes and confidence to supportively challenge negative attitudes in practice were found. Students showed a shift away from a focus on changing the perceived "difficult" behaviour of a client towards an understanding of their own emotional responses to the behaviours. Discussion The Knowledge and Understanding Framework training shows potential for students to change attitudes and develop progressive practice working with people with personality disorder. Implications for practice The integration of the Knowledge and Understanding Framework should be considered as part of preregistration training. Further research into the sustained influence of the training post registration is required.

Abstract 2101: The growth of a xenograft breast cancer tumor model with engineered hyaluronan-accumulating stroma is dependent on hyaluronan and independent of CD44

The abnormal accumulation of hyaluronan in the solid tumor microenvironment is associated with poor prognosis in several human cancers. Hyaluronan often accumulates in the tumor stroma. To understand the role of hyaluronan-accumulating stroma in tumor progression, we engineered a hyaluronan-producing fibroblast cell line 3T3HAS3 by lentiviral transduction of the human hyaluronan synthase 3 gene into Balb/c 3T3 cells. The 3T3HAS3 cells produced significant amounts of hyaluronan in vitro, which bind to the cell surface of the human breast cancer cell line MDA-MB-468. When co-grafted with MDA-MB-468 cells in nude mice, 3T3HAS3 significantly enhanced tumor growth. Immunohistochemical analysis of tumor xenografts showed that MDA-MB-468 cells were surrounded by hyaluronan-accumulating stroma, closely resembling the morphology observed in human breast cancer specimens. Tumor growth of this co-graft model required hyaluronan production from 3T3HAS3 cells, as demonstrated by the delayed tumor growth upon hyaluronan removal by expression of the human PH20 gene in 3T3HAS3 cells, or by systemic administration of PEGylated recombinant human PH20 (PEGPH20). In contrast, neither the expression of CD44, a well-characterized hyaluronan receptor, in tumor and stromal fibroblasts, nor the binding of hyaluronan to CD44 in MDA-MB-468 tumor cells was essential for tumor growth. Small scale screening of signaling changes in xenograft tumors suggested that the AMPK/mTOR pathway may respond to hyaluronan removal by PEGPH20. Collectively, these data demonstrate that the growth of an engineered breast cancer xenograft model with hyaluronan-accumulating stroma is dependent on hyaluronan, and that hyaluronan-CD44 interaction may not be the main mechanism through which hyaluronan promotes tumor progression in certain tumors.

Citation Format: Chunmei Zhao, Benjamin J. Thompson, Kelly Chen, Mathieu Marella, Susan Zimmerman, Trevor Kimbler, Barbara Blouw, Sheryl Garrovillo, Lei Huang, Adrian Radi, Zhongdong Huang, H. Michael Shepard, Sanna Rosengren, Christopher D. Thanos, Daniel C. Maneval. The growth of a xenograft breast cancer tumor model with engineered hyaluronan-accumulating stroma is dependent on hyaluronan and independent of CD44 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2101.

Abstract 1743: Rationale for evaluating PEGylated recombinant human hyaluronidase PH20 (pegvorhyaluronidase alfa; PEGPH20) in patients with hyaluronan (HA)-accumulating colorectal cancer

Colorectal cancer is the third most common cancer, and the third most common cause of cancer-related death, among both men and women in the United States. To address this unmet clinical need, ongoing efforts have focused on classifying different subtypes of colorectal cancer, with the goal of identifying therapies with the highest likelihood of success for a given tumor subtype. One marker that has been associated with poor clinical outcome in multiple solid tumor types, including colorectal cancer, is the accumulation of the glycosaminoglycan hyaluronan (HA), which, in preclinical tumor models, increases interstitial fluid pressure, compresses tumor vasculature, and restricts the access of therapeutics. PEGylated recombinant human hyaluronidase PH20 (pegvorhyaluronidase alfa; PEGPH20), which enzymatically degrades HA, is currently being evaluated in combination with existing therapies in clinical trials for HA-accumulating pancreatic, gastric, non-small cell lung, and bile duct cancers. Here, we review the available data for PEGPH20 as published by the authors to evaluate the potential utility of PEGPH20 in treating colorectal cancer. We first studied PEGPH20 in two HA-accumulating murine colon tumor models: CT26 transduced with hyaluronan synthase-3 (HAS3) and MC38 (Charles River Laboratories). In CT26-HAS3 tumors, PEGPH20 monotherapy induced 43% tumor growth inhibition and was associated with tumor blood vessel decompression. In combination with anti-CTLA4 treatment, PEGPH20 further enhanced tumor growth inhibition (79%, p≤0.002 vs anti-CTLA4 alone and PEGPH20 alone). In MC38 tumors, combination of PEGPH20 with anti-PD-L1 treatment significantly increased infiltration of CD8+ T cells (2.8-fold, p<0.05) and NK cells (3-fold, p<0.0001) compared with anti-PD-L1 alone. We then investigated the prevalence of HA accumulation in human colorectal cancer. To do this, we histologically analyzed 138 patient tumor specimens for stromal content and presence of HA. In 38 samples (28%), ≥50% of the tumor stromal area stained positive for HA. Additionally, Phase 1 studies with single agent PEGPH20 included several subjects with colorectal cancer. Pharmacodynamic measurements before and after treatment demonstrated increased tumor perfusion as measured by median volume transfer constant (Ktrans), decreased tumor metabolic activity as measured by 18F-FDG-PET/CT in one patient, and decreased tumor HA following PEGPH20 administration. Collectively, these data warrant further investigation of the potential for PEGPH20 to benefit patients with HA-high colorectal cancer.

Citation Format: Renee Clift, Benjamin J. Thompson, Darin Taverna, Barbara Blouw, Jisook Lee, Curtis B. Thompson, Daniel C. Maneval. Rationale for evaluating PEGylated recombinant human hyaluronidase PH20 (pegvorhyaluronidase alfa; PEGPH20) in patients with hyaluronan (HA)-accumulating colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1743.

DYRK1A controls the transition from proliferation to quiescence during lymphoid development by destabilizing Cyclin D3

Pre-B and pre-T lymphocytes must orchestrate a transition from a highly proliferative state to a quiescent one during development. Cyclin D3 is essential for these cells' proliferation, but little is known about its posttranslational regulation at this stage. Here, we show that the dual specificity tyrosine-regulated kinase 1A (DYRK1A) restrains Cyclin D3 protein levels by phosphorylating T283 to induce its degradation. Loss of DYRK1A activity, via genetic inactivation or pharmacologic inhibition in mice, caused accumulation of Cyclin D3 protein, incomplete repression of E2F-mediated gene transcription, and failure to properly couple cell cycle exit with differentiation. Expression of a nonphosphorylatable Cyclin D3 T283A mutant recapitulated these defects, whereas inhibition of Cyclin D:CDK4/6 mitigated the effects of DYRK1A inhibition or loss. These data uncover a previously unknown role for DYRK1A in lymphopoiesis, and demonstrate how Cyclin D3 protein stability is negatively regulated during exit from the proliferative phases of B and T cell development.

Sex comparisons of strength and coactivation following ten weeks of deadlift training

OBJECTIVES

To examine the effects of a ten week deadlift training program on peak torque and agonist-antagonist coactivation.

METHODS

Fifty-four untrained subjects (mean age=23 years) participated in this investigation, and were randomly assigned to a training (males, n=17; females, n=17) or control (males, n=9; females, n=11) group. The subjects in the training group performed deadlifts twice per week. Isometric peak torque for the leg extensors and flexors and surface electromyographic (EMG) amplitude for the superficial quadriceps and biceps femoris muscles were assessed.

RESULTS

Deadlift training increased leg extension peak torque for the males (P=.008, Cohen's d=0.43) and females (P=.003, d=0.48). Leg flexion peak torque improved for the females (P=.001, d=0.45). Increased EMG amplitude for the superficial quadriceps femoris muscles when they served as agonists was demonstrated for the females (P=.010, d=0.40), but not the males (P=.059, d=0.20). For both sexes, the effect sizes for the decline in biceps femoris coactivation were large.

CONCLUSION

Deadlift training elicited improvements in strength and agonist-antagonist coactivation in untrained subjects, and particularly, novice females.

The effects of a high-intensity free-weight back-squat exercise protocol on postural stability in resistance-trained males

The purpose of this study was to investigate the effects of a high-intensity free-weight back-squat exercise on postural stability characteristics in resistance-trained males. Eighteen college-aged (mean ± SD: age = 22.9 ± 2.9 years; height = 175.8 ± 6.4 cm; mass = 86.3 ± 9.3 kg), resistance-trained males performed postural stability testing before and after completing five sets of eight repetitions of back-squat exercises at 80% of one-repetition maximum. A commercial balance testing device was used to assess sway index at pre- and at 0, 5, 10, 15 and 20 min post-exercise. Each balance assessment consisted of four, 20-s static stance conditions: eyes-open firm surface, eyes-closed firm surface, eyes-open soft surface and eyes-closed soft surface. Sway index was greater (P = 0.001-0.020) at Post 0 than at all other time points. No differences (P > 0.05) were observed between any other time phases. Sway index was greater (P < 0.001) for eyes-closed soft surface than all other conditions. These findings revealed sway index for all conditions significantly increased following completion of the back-squat; however, sway index recovered within 5 min of exercise. Higher sway index values as a result of neuromuscular fatigue induced by a back-squat exercise may have performance and injury risk consequences to subsequent activities that rely on postural stability. However, these findings suggest balance impairments may recover in ~5 min following high-intensity lower body resistance exercise.

Influence of acute eccentric exercise on the H:Q ratio

The purpose of the present study was to examine the effects of an acute bout of eccentric exercise on maximal isokinetic concentric peak torque (PT) of the leg flexors and extensors and the hamstrings-to-quadriceps (H:Q) strength ratio. Sixteen male (mean±SD: age=20.9±2 years; stature=177.0±4.4 cm; mass=76.8±10.0 kg) volunteers performed maximal, concentric isokinetic leg extension and flexion muscle actions at 60°·sec - 1 before and after (24-72 h) a bout of eccentric exercise. The eccentric exercise protocol consisted of 4 sets of 10 repetitions for the leg press, leg extension, and leg curl exercises at 120% of the concentric one repetition maximum (1-RM). The results indicated that the acute eccentric exercise protocol resulted in a significant (P<0.05) decrease in isokinetic leg flexion (13-19%) and leg extension (11-16%) PT 24-72 h post-exercise. However, the H:Q ratios were unaltered by the eccentric exercise protocol. These findings suggest that an acute bout of eccentric exercise utilizing both multi - and single - joint dynamic constant external resistance (DCER) exercises results in similar decreases in maximal isokinetic strength of the leg flexors and extensors, but does not alter the H:Q ratio.

Dissecting the complete lipoprotein biogenesis pathway in Streptomyces scabies

Following translocation, bacterial lipoproteins are lipidated by lipoprotein diacylglycerol transferase (Lgt) and cleaved of their signal peptides by lipoprotein signal peptidase (Lsp). In Gram-negative bacteria and mycobacteria, lipoproteins are further lipidated by lipoprotein N-acyl transferase (Lnt), to give triacylated lipoproteins. Streptomyces are unusual amongst Gram-positive bacteria because they export large numbers of lipoproteins via the twin arginine protein transport (Tat) pathway. Furthermore, some Streptomyces species encode two Lgt homologues and all Streptomyces species encode two homologues of Lnt. Here we characterize lipoprotein biogenesis in the plant pathogen Streptomyces scabies and report that lgt and lsp mutants are defective in growth and development while only moderately affected in virulence. Lipoproteins are lost from the membrane in an S. scabies lgt mutant but restored by expression of Streptomyces coelicolor lgt1 or lgt2 confirming that both encode functional Lgt enzymes. Furthermore, lipoproteins are N-acylated in Streptomyces with efficient N-acylation dependent on Lnt1 and Lnt2. However, deletion of lnt1 and lnt2 has no effect on growth, development or virulence. We thus present a detailed study of lipoprotein biogenesis in Streptomyces, the first study of Lnt function in a monoderm bacterium and the first study of bacterial lipoproteins as virulence factors in a plant pathogen.

Investigating lipoprotein biogenesis and function in the model Gram-positive bacterium Streptomyces coelicolor

Lipoproteins are a distinct class of bacterial membrane proteins that are translocated across the cytoplasmic membrane primarily by the Sec general secretory pathway and then lipidated on a conserved cysteine by the enzyme lipoprotein diacylglycerol transferase (Lgt). The signal peptide is cleaved by lipoprotein signal peptidase (Lsp) to leave the lipid-modified cysteine at the N-terminus of the mature lipoprotein. In all Gram-positive bacteria tested to date this pathway is non-essential and the lipid attaches the protein to the outer leaflet of the cytoplasmic membrane. Here we identify lipoproteins in the model Gram-positive bacterium Streptomyces coelicolor using bioinformatics coupled with proteomic and downstream analysis. We report that Streptomyces species translocate large numbers of lipoproteins out via the Tat (twin arginine translocase) pathway and we present evidence that lipoprotein biogenesis might be an essential pathway in S. coelicolor. This is the first analysis of lipoproteins and lipoprotein biogenesis in Streptomyces and provides the first evidence that lipoprotein biogenesis could be essential in a Gram-positive bacterium. This report also provides the first experimental evidence that Tat plays a major role in the translocation of lipoproteins in a specific bacterium.

Control of hematopoietic stem cell quiescence by the E3 ubiquitin ligase Fbw7

Ubiquitination is a posttranslational mechanism that controls diverse cellular processes. We focus here on the ubiquitin ligase Fbw7, a recently identified hematopoietic tumor suppressor that can target for degradation several important oncogenes, including Notch1, c-Myc, and cyclin E. We have generated conditional Fbw7 knockout animals and inactivated the gene in hematopoietic stem cells (HSCs), progenitors, and their differentiated progeny. Deletion of Fbw7 specifically and rapidly affects hematopoiesis in a cell-autonomous manner. Fbw7(-/-) HSCs show defective maintenance of quiescence, leading to impaired self-renewal and a severe loss of competitive repopulating capacity. Furthermore, Fbw7(-/-) progenitors are unable to colonize the thymus, leading to a profound depletion of T cell progenitors. Deletion of Fbw7 in bone marrow (BM) stem cells and progenitors leads to the stabilization of c-Myc, a transcription factor previously implicated in HSC self-renewal. On the other hand, neither Notch1 nor cyclin E is visibly stabilized in the BM of Fbw7-deficient mice. Gene expression studies of Fbw7(-/-) HSCs and hematopoietic progenitors indicate that Fbw7 regulates, through the regulation of HSC cycle entry, the transcriptional "signature" that is associated with the quiescent, self-renewing HSC phenotype.

The SCFFBW7 ubiquitin ligase complex as a tumor suppressor in T cell leukemia

Recent studies have shown that activating mutations of NOTCH1 are responsible for the majority of T cell acute lymphoblastic leukemia (T-ALL) cases. Most of these mutations truncate its C-terminal domain, a region that is important for the NOTCH1 proteasome-mediated degradation. We report that the E3 ligase FBW7 targets NOTCH1 for ubiquitination and degradation. Our studies map in detail the amino acid degron sequence required for NOTCH1–FBW7 interaction. Furthermore, we identify inactivating FBW7 mutations in a large fraction of human T-ALL lines and primary leukemias. These mutations abrogate the binding of FBW7 not only to NOTCH1 but also to the two other characterized targets, c-Myc and cyclin E. The majority of the FBW7 mutations were present during relapse, and they were associated with NOTCH1 HD mutations. Interestingly, most of the T-ALL lines harboring FBW7 mutations were resistant to γ-secretase inhibitor treatment and this resistance appeared to be related to the stabilization of the c-Myc protein. Our data suggest that FBW7 is a novel tumor suppressor in T cell leukemia, and implicate the loss of FBW7 function as a potential mechanism of drug resistance in T-ALL.

Temperature alters lipopolysaccharide-induced cytokine secretion by RAW 264.7 cells

Local and systemic temperature change is associated with the immune response to infection, but the role of temperature remains poorly understood. To study the effect of temperature on macrophage activation by lipopolysaccharide (LPS), RAW 264.7 cells were incubated with LPS at different temperatures and secretion of three cytokines was measured. Incubation at 31 degrees C increased tumour necrosis factor (TNF) secretion when compared with 37 degrees C, while cells exposed at 39 degrees C secreted less TNF. Interleukin-6 (IL-6) secretion was less at 31 degrees C than at 37 degrees C and remained unchanged at 39 degrees C. Interleukin-10 secretion was depressed on either side of 37 degrees C. Only IL-6 secretion was sensitive to preincubation temperature effects. The kinetics of cytokine secretion and steady-state mRNA analysis indicated potentially different mechanisms of temperature regulation for TNF and IL-6.

Transcription factor FnrP from Paracoccus denitrificans contains an iron-sulfur cluster and is activated by anoxia: identification of essential cysteine residues

The Paracoccus denitrificans transcription factor FnrP has been characterized using artificial FNR-dependent promoter-lacZ fusion plasmids in Escherichia coli. FnrP can activate both class I and class II FNR-dependent promoters in response to anoxia but shows a marked preference for the class II promoter, where the FNR binding site is centered at -41.5 with respect to the transcription start site. FnrP was found to be inactive in an iscS mutant in vivo, demonstrating a requirement for cysteine desulfurase activity to assemble an iron-sulfur cluster in FnrP. Accordingly, an iron-sulfur cluster could be reconstituted into the purified protein in vitro using cysteine desulfurase, ferrous ions, and cysteine. Thus, FnrP is a true orthologue of FNR from E. coli and switches on target genes in response to anoxia. Inactivation of FnrP by oxygen very likely involves the oxidative disassembly of an iron-sulfur cluster. Possible ligands for the iron-sulfur cluster were identified by substituting each of the seven cysteine residues with serine and characterizing the altered proteins in vivo. Four substituted proteins showed activities less than 5% of the wild type, and so identify the four cysteines (Cys-14, Cys-17, Cys-25, and Cys-113) that are most likely to be involved in cluster ligation. The effects of N-oxides, NO-releasing compounds and a nitrosating agent on FNR and FnrP activity were investigated in vivo using the reporter system. Both proteins are very sensitive to the inclusion of sodium nitroprusside (a source of NO(+)) in defined growth media but are only moderately sensitive to those sources of NO that were tested.

Identification of genes induced by growth hormone in rat liver using cDNA arrays

Growth hormone (GH) is a pleiotropic cytokine that acts upon its target cells to regulate their growth, differentiation and metabolism. GH is thought to act by altering gene expression in target cells, but few GH-regulated genes are known. In this study, we used cDNA array analysis to identify genes rapidly induced in the liver of GH-deficient dwarf rats following a single systemic injection of GH. Eight genes were found to upregulate their mRNA expression within 1-3 hours of GH administration, results which were confirmed by northern analysis. The identity of these genes suggests GH may influence a diversity of cellular processes. A role for GH in regulating cytokine and growth factor signalling is suggested by upregulation of mRNAs encoding three signal transducers: a subunit of the receptor for IL-6-type cytokines (gp130), STAT3 (signal transducer and activator of transcription) and p38MAPK (mitogen activated protein kinase). Two genes involved in DNA repair and cell cycle control, APEN (apurinic endonuclease) and GADD45 (growth arrest and DNA damage 45) were upregulated. Other induced genes include those encoding a lactate transporter (MCT-1), an extracellular matrix remodelling enzyme, MTI-MMP (membrane type 1 matrix metalloproteinase) and an acute phase protein (fibrinogen beta). In summary, this work is the first to apply cDNA arrays to the study of peptide hormone action in vivo and has identified 8 novel GH target genes.

Further analysis of maize C(4) pyruvate,orthophosphate dikinase phosphorylation by its bifunctional regulatory protein using selective substitutions of the regulatory Thr-456 and catalytic His-458 residues

In C(4) plants such as maize, pyruvate,orthophosphate dikinase (PPDK) catalyzes the regeneration of the initial carboxylation substrate during C(4) photosynthesis. The primary catalytic residue, His-458 (maize C(4) PPDK), is involved in the ultimate transfer of the beta-phosphate from ATP to pyruvate. C(4) PPDK activity undergoes light-dark regulation in vivo by reversible phosphorylation of a nearby active-site residue (Thr-456) by a single bifunctional regulatory protein (RP). Using site-directed mutagenesis of maize recombinant C(4) dikinase, we made substitutions at the catalytic His residue (H458N) and at this regulatory target Thr (T456E, T456Y, T456F). Each of these affinity-purified mutant enzymes was assayed for changes in dikinase activity. As expected, substituting His-458 with Asn results in a catalytically incompetent enzyme. Substitutions of the Thr-456 residue with Tyr and Phe reduced activity by about 94 and 99%, respectively. Insertion of Glu at this position completely abolished activity, presumably by the introduction of negative charge proximal to the catalytic His. Furthermore, neither the T456Y nor inactive H458N mutant enzyme was phosphorylated in vitro by RP. The inability of the former to serve as a phosphorylation substrate indicates that RP is functionally a member of the Ser/Thr family of protein kinases rather than a "dual-specificity" Ser-Thr/Tyr kinase, since our previous work showed that RP effectively phosphorylated Ser inserted at position 456. The inability of RP to phosphorylate its native target Thr residue when Asn is substituted for His-458 documents that RP requires the His-P catalytic intermediate form of PPDK as its protein substrate. For these latter studies, synthetic phosphopeptide-directed antibodies specific for the Thr(456)-P form of maize C(4) PPDK were developed and characterized.

Lessons from the front: implementing outcomes projects

These issues are representative of the challenges facing those wishing to implement outcomes evaluations in the dramatically different settings of today's behavioral healthcare. To maintain acceptable levels of credibility, difficult issues such as these need to be addressed openly and assertively. We remain optimistic about the value of measuring the effects of behavioral healthcare interventions. Such measurement facilitates the development of communication across service providers and creates accountability where once there was none. When standards of quality research are applied, outcomes management offers great potential benefit to consumers, providers, and behavioral healthcare organizations.

Maize recombinant C4-pyruvate,orthophosphate dikinase: Expression in Escherichia coli, partial purification, and characterization of the phosphorylatable protein

The gene for C4-pyruvate,orthophosphate dikinase (PPDK) from maize (Zea mays) was cloned into an Escherichia coli expression vector and recombinant PPDK produced in E. coli cells. Recombinant enzyme was found to be expressed in high amounts (5.3 U purified enzyme-activity liter(-1) of induced cells) as a predominantly soluble and active protein. Biochemical analysis of partially purified recombinant PPDK showed this enzyme to be equivalent to enzyme extracted from illuminated maize leaves with respect to (i) molecular mass, (ii) specific activity, (iii) substrate requirements, and (iv) phosphorylation/inactivation by its bifunctional regulatory protein.

Biosynthesis of fatty acids by lactating human breast epithelial cells: an evaluation of the contribution to the overall composition of human milk fat

The objective of this study was to characterize the fatty acid biosynthetic pathway of the lactating human breast. Mixed cell populations, obtained by centrifugation of human milk, were enriched in breast epithelial cells by a selective adsorption procedure. Confirmation of the identity of the breast epithelial cells was obtained immunohistochemically. These viable breast epithelial cells incorporated radioactively labeled acetate predominantly into fatty acids with less than 16C atoms. The presence of the two key enzymes characteristic of the medium-chain fatty acid biosynthetic pathway of nonruminants, fatty acid synthetase, and thioesterase II, was demonstrated both qualitatively, by immunohistochemistry, and quantitatively, by enzyme assay. The results indicate that the lipogenic system of the human breast is qualitatively very similar to that of rats, mice, and rabbits, which also secrete milk fats containing medium-chain fatty acids. Quantitatively, however, the mammary fatty acid biosynthetic pathway appears to be less active in humans than in these other species.

Thioesterase II, a new marker enzyme for human cells of breast epithelial origin

Metabolic, enzymologic, and immunohistochemical techniques have been used to show that a human cell line of breast epithelial origin synthesized medium chain fatty acids via the ubiquitous fatty acid synthetase and a mammary-specific chain-terminating enzyme, thioesterase II. Previous studies in our laboratory with rodents indicated that thioesterase II is expressed exclusively in mammary epithelial cells, an observation consistent with the physiologic role of the enzyme in milk fat synthesis. Results of the present study suggest that the enzyme exhibits a similar cell specificity in its expression in humans and that the specificity is maintained in normal and neoplastic tissues. Thus thioesterase II was detected immunohistochemically in normal human breast epithelia derived from both lactating and nonlactating breast tissue, in cultured cells derived from both primary breast epithelial tumors and from a metastatic tumor of breast origin, and in several human breast epithelial cell lines; the enzyme could not be detected in HeLa cells, in a colon carcinoma, or in a mammary myoepithelial cell line. These findings raise the possibility that thioesterase II may be of use as a diagnostic tool to identify human tumors of breast epithelial origin.

Localization of thioesterase II, the chain-length regulatory enzyme of milk fatty acid synthesis, in rat mammary gland epithelial cells

Two approaches were used to establish the intercellular distribution of fatty acid synthetase and thioesterase II in the lactating rat mammary gland. Thioesterase II is the chain-length regulatory enzyme in the biosynthesis of the medium-chain fatty acids characteristic of milk fat. Using immunohistochemical techniques, immunoreactive fatty acid synthetase was found in both mammary adipocytes and epithelial cells; in contrast, immunoreactive epithelial cells were isolated from lactating rat mammary glands after digestion with collagenase and thermolysin, and their lipogenic activity was studied using isotopically labelled acetate. Consistent with the immunohistochemical data, adipocytes synthesized exclusively long-chain fatty acids whereas epithelial cells synthesized predominantly chain fatty acids. The results indicate that the capacity for synthesis of medium-chain fatty acids is a unique property of the epithelial cell component of the mammary gland.

Lack of coordinated regulation of lipogenic enzymes in a human breast cell line, SKBr3

A human breast cell line has been identified which contains prodigious levels of fatty acid synthetase but has a very low capacity for lipogenesis from glucose, lactate or acetate. The fatty acid synthetase from this cell line appears to be structurally and functionally normal, and the low lipogenic capacity of the cells appears to be due to the low activities of other lipogenic enzymes, notably acetyl-CoA carboxylase. Thus, the SKBr3 cell line appears to lack the long-term coordinated control of acetyl-CoA carboxylase and fatty acid synthetase commonly observed in normal lipogenic tissues.

Far-field holography of ampule contaminants

Detection and measurement of contaminating particles in cylindrical ampules have been achieved using far-field holography. The degradation of the images caused by the cylindrical nature of the ampule was overcome by index matching and clear images of particles as small as 5 microm in diameter were obtained.

Purification and properties of fatty acid synthetase from a human breast cell line

A human mammary epithelial cell line (SKBr3) has been identified in which fatty acid synthetase constitutes up to 28%, by weight of the cytosolic proteins. The enzymes has been purified to near homogeneity from this cell line and some of its properties studied. In common with fatty acid synthetases from other animal tissues, the enzyme is a 480 000 dalton dimer of similar molecular weight subunits, it synthesizes predominantly palmitic acid and is inactive in the absence of free coenzyme A. The kinetic properties and amino acid composition of the enzyme are also similar to those of fatty acid synthetases from various tissues of other animals. Appreciable structural resemblance between human and rodent fatty acid synthetases is indicated by studies on the immunological cross-reactivities of these enzymes.

Lau effect: theory and experiment

It was recently shown that coherence theory provides a simple and elegant means of interpreting and extending the Lau effect. The details of this analysis are presented along with experimental results which show good qualitative agreement with the predicted intensity distributions. In addition an unexpected intensity modulation is observed which is readily explained in terms of the present analysis.