Medical management and surgery versus medical management alone for symptomatic cerebral cavernous malformation (CARE): a feasibility study and randomised, open, pragmatic, pilot phase trial

BACKGROUND

The highest priority uncertainty for people with symptomatic cerebral cavernous malformation is whether to have medical management and surgery or medical management alone. We conducted a pilot phase randomised controlled trial to assess the feasibility of addressing this uncertainty in a definitive trial.

METHODS

The CARE pilot trial was a prospective, randomised, open-label, assessor-blinded, parallel-group trial at neuroscience centres in the UK and Ireland. We aimed to recruit 60 people of any age, sex, and ethnicity who had mental capacity, were resident in the UK or Ireland, and had a symptomatic cerebral cavernous malformation. Computerised, web-based randomisation assigned participants (1:1) to medical management and surgery (neurosurgical resection or stereotactic radiosurgery) or medical management alone, stratified by the neurosurgeon's and participant's consensus about the intended type of surgery before randomisation. Assignment was open to investigators, participants, and carers, but not clinical outcome event adjudicators. Feasibility outcomes included site engagement, recruitment, choice of surgical management, retention, adherence, data quality, clinical outcome event rate, and protocol implementation. The primary clinical outcome was symptomatic intracranial haemorrhage or new persistent or progressive non-haemorrhagic focal neurological deficit due to cerebral cavernous malformation or surgery during at least 6 months of follow-up. We analysed data from all randomly assigned participants according to assigned management. This trial is registered with ISRCTN (ISRCTN41647111) and has been completed.

FINDINGS

Between Sept 27, 2021, and April 28, 2023, 28 (70%) of 40 sites took part, at which investigators screened 511 patients, of whom 322 (63%) were eligible, 202 were approached for recruitment, and 96 had collective uncertainty with their neurosurgeon about whether to have surgery for a symptomatic cerebral cavernous malformation. 72 (22%) of 322 eligible patients were randomly assigned (mean recruitment rate 0·2 [SD 0·25] participants per site per month) at a median of 287 (IQR 67-591) days since the most recent symptomatic presentation. Participants' median age was 50·6 (IQR 38·6-59·2) years, 68 (94%) of 72 participants were adults, 41 (57%) were female, 66 (92%) were White, 56 (78%) had a previous intracranial haemorrhage, and 28 (39%) had a previous epileptic seizure. The intended type of surgery before randomisation was neurosurgical resection for 19 (26%) of 72, stereotactic radiosurgery for 44 (61%), and no preference for nine (13%). Baseline clinical and imaging data were complete for all participants. 36 participants were randomly assigned to medical management and surgery (12 to neurosurgical resection and 24 to stereotactic radiosurgery) and 36 to medical management alone. Three (4%) of 72 participants withdrew, one was lost to follow-up, and one declined face-to-face follow-up, leaving 67 (93%) retained at 6-months' clinical follow-up. 61 (91%) of 67 participants with follow-up adhered to the assigned management strategy. The primary clinical outcome occurred in two (6%) of 33 participants randomly assigned to medical management and surgery (8·0%, 95% CI 2·0-32·1 per year) and in two (6%) of 34 participants randomly assigned to medical management alone (7·5%, 1·9-30·1 per year). Investigators reported no deaths, no serious adverse events, one protocol violation, and 61 protocol deviations.

INTERPRETATION

This pilot phase trial exceeded its recruitment target, but a definitive trial will require extensive international engagement.

FUNDING

National Institute for Health and Care Research.

Mapping the prevalence of cancer risk factors at the small area level in Australia

BACKGROUND

Cancer is a significant health issue globally and it is well known that cancer risk varies geographically. However in many countries there are no small area-level data on cancer risk factors with high resolution and complete reach, which hinders the development of targeted prevention strategies.

METHODS

Using Australia as a case study, the 2017-2018 National Health Survey was used to generate prevalence estimates for 2221 small areas across Australia for eight cancer risk factor measures covering smoking, alcohol, physical activity, diet and weight. Utilising a recently developed Bayesian two-stage small area estimation methodology, the model incorporated survey-only covariates, spatial smoothing and hierarchical modelling techniques, along with a vast array of small area-level auxiliary data, including census, remoteness, and socioeconomic data. The models borrowed strength from previously published cancer risk estimates provided by the Social Health Atlases of Australia. Estimates were internally and externally validated.

RESULTS

We illustrated that in 2017-2018 health behaviours across Australia exhibited more spatial disparities than previously realised by improving the reach and resolution of formerly published cancer risk factors. The derived estimates revealed higher prevalence of unhealthy behaviours in more remote areas, and areas of lower socioeconomic status; a trend that aligned well with previous work.

CONCLUSIONS

Our study addresses the gaps in small area level cancer risk factor estimates in Australia. The new estimates provide improved spatial resolution and reach and will enable more targeted cancer prevention strategies at the small area level. Furthermore, by including the results in the next release of the Australian Cancer Atlas, which currently provides small area level estimates of cancer incidence and relative survival, this work will help to provide a more comprehensive picture of cancer in Australia by supporting policy makers, researchers, and the general public in understanding the spatial distribution of cancer risk factors. The methodology applied in this work is generalisable to other small area estimation applications and has been shown to perform well when the survey data are sparse.

Lung Imaging in COPD Part 2: Emerging Concepts

The diagnosis, prognostication, and differentiation of phenotypes of COPD can be facilitated by CT scan imaging of the chest. CT scan imaging of the chest is a prerequisite for lung volume reduction surgery and lung transplantation. Quantitative analysis can be used to evaluate extent of disease progression. Evolving imaging techniques include micro-CT scan, ultra-high-resolution and photon-counting CT scan imaging, and MRI. Potential advantages of these newer techniques include improved resolution, prediction of reversibility, and obviation of radiation exposure. This article discusses important emerging techniques in imaging patients with COPD. The clinical usefulness of these emerging techniques as they stand today are tabulated for the benefit of the practicing pulmonologist.

Lung Imaging in COPD Part 1: Clinical Usefulness

COPD is a condition characterized by chronic airflow obstruction resulting from chronic bronchitis, emphysema, or both. The clinical picture is usually progressive with respiratory symptoms such as exertional dyspnea and chronic cough. For many years, spirometry was used to establish a diagnosis of COPD. Recent advancements in imaging techniques allow quantitative and qualitative analysis of the lung parenchyma as well as related airways and vascular and extrapulmonary manifestations of COPD. These imaging methods may allow prognostication of disease and shed light on the efficacy of pharmacologic and nonpharmacologic interventions. This is the first of a two-part series of articles on the usefulness of imaging methods in COPD, and it highlights useful information that clinicians can obtain from these imaging studies to make more accurate diagnosis and therapeutic decisions.

RUPP Th17s cause hypertension and mitochondrial dysfunction in the kidney and placenta during pregnancy

BACKGROUND

Preeclampsia (PE), new-onset hypertension (HTN), and organ dysfunction during the second half of pregnancy, is associated with an increase in inflammatory immune cells, including T helper 17 (Th17) cells. Studies have demonstrated that mitochondrial (mt) dysfunction is important in the pathogenesis of PE though causative factors have yet to be fully identified. Although Th17 cells, natural killer (NK) cells, and mt dysfunction contribute to HTN in the reduced uterine perfusion pressure (RUPP) rat model, the role of Th17 cells or IL-17 in mt dysfunction is unknown. Therefore, we hypothesize that RUPP stimulated Th17 cells cause HTN and mt dysfunction, which is alleviated with the blockade of IL-17.

METHODS

On gestational day 12 (GD12), RUPP Th17 cells were transferred into normal pregnant (NP) Sprague Dawley rats. A subset of NP + RUPPTh17 rats received IL-17RC (100 pg/day) on GD14-19. Blood pressure (MAP), NK cells, and mt function were measured on GD19 in all groups.

RESULTS

MAP increased in response to NP + RUPP Th17 compared to NP rats and was lowered with IL-17RC. Circulating and placental NK cells increased with NP + RUPP Th17 compared to NP and were lowered with IL-17RC. Renal mtROS increased in NP + RUPP Th17 compared to NP and was normalized with IL-17RC. Similar to PE women, placental mtROS decreased in NP + RUPP Th17 and was normalized with IL-17RC.

CONCLUSION

Our results indicate that IL-17RC inhibition normalizes HTN, NK cell activation, and multi-organ mt dysfunction caused by Th17 cells stimulated in response to placental ischemia.

Abstract 26: IL-17 Causes Hypertension, Reduced Fetal Weight And Natural Killer Cell Activation In The Absence Of T Cells

Preeclampsia (PE) is characterized by new onset hypertension (HTN), intrauterine growth restriction (IUGR), multi-organ dysfunction, and is associated with increased inflammatory cytokines, such as interleukin 17 (IL-17). More recent studies demonstrate a role for mitochondrial (mt) dysfunction/mtROS in the pathogenesis of PE. Although we have shown T helper cells from a rat model of PE cause HTN and mt dysfunction the causative factors for mt dysfunction are still being identified. In addition, we have shown that IL-17 cause HTN, IUGR and activate natural killer (NK) cells, and cause mt dysfunction in pregnant Sprague Dawley rats. However, in our previous studies we couldn’t differentiate the effect of activated TH cells versus IL-17 to cause these characteristics of PE. The athymic nude rat model lacks mature T cells but does have other components of the immune system, and will thus allow us to examine the role of IL-17 in the absence of TH cells in the pathophysiology of PE. We hypothesize that in the absence of T cells IL-17 induces HTN, NK cell activation and IUGR which is associated with renal and placental mt dysfunction during pregnancy. To test our hypothesis, IL-17 (150 pg/day) was infused via osmotic minipumps inserted on gestation day (GD) 14. Blood pressure (MAP) and mt function were measured on GD19 and were compared to untreated pregnant (NP) athymic nude rats. In response to IL-17; MAP increased from 95±4mmHg in NP(n=6) to 115±2 in NP+IL-17(n=6) (p<0.001); pup weight decreased from 1.46±0.2 g in NP (n=6) to 0.98±0.07g in NP+IL-17 (n=6) (p<0.05); NK cell activation increased from 0±0 %lymphocytes in NP (n=3) to 0.4±0.1% lymphocytes in NP+IL-17 rats (n=6). Interestingly, placental mtROS reduced 54% fold compared to NP and renal mtROS reduced 51.2% compared to NP. ATP production increased from 15.53±1.6 pmol of O2/sec/mg in NP (n=3) to 105.5±91 pmol of O2/sec/mg in NP+IL-17 (n=3) in the placenta, and from 1196±460 pmol of O2/sec/mg in NP (n=4) to 2016±951 pmol of O2/sec/mg NP+IL17 (n=4) in the kidney. These results show that although IL-17 induces HTN, IUGR, and NK cell activation independent of T cells, T cells are necessary for reduced mitochondrial function observed in PE and in rat models of placental ischemia.

Seven Pillars of Small Airways Disease in Asthma and COPD: Supporting Opportunities for Novel Therapies

Identification of pathologic changes in early and mild obstructive lung disease has shown the importance of the small airways and their contribution to symptoms. Indeed, significant small airways dysfunction has been found prior to any overt airway obstruction being detectable by conventional spirometry techniques. However, most therapies for the treatment of obstructive lung disease target the physiological changes and associated symptoms that result from chronic lung disease, rather than directly targeting the specific underlying causes of airflow disruption or the drivers of disease progression. In addition, although spirometry is the current standard for diagnosis and monitoring of response to therapy, the most widely used measure, FEV1 , does not align with the pathologic changes in early or mild disease and may not align with symptoms or exacerbation frequency in the individual patient. Newer functional and imaging techniques allow more effective assessment of small airways dysfunction; however, significant gaps in our understanding remain. Improving our knowledge of the role of small airways dysfunction in early disease in the airways, along with the identification of novel end points to measure subclinical changes in this region (ie, those not captured as symptoms or identified through standard FEV1), may lead to the development of novel therapies that directly combat early airways disease processes with a view to slowing disease progression and reversing damage. This expert opinion paper discusses small airways disease in the context of asthma and COPD and highlights gaps in current knowledge that impede earlier identification of obstructive lung disease and the development and standardization of novel small airways-specific end points for use in clinical trials.

A systematic review of cellular therapies for the treatment of limbal stem cell deficiency affecting one or both eyes

PURPOSE

This systematic review (SR) assessed the efficacy, safety and cost-effectiveness of cell-based therapy to manage limbal stem cell deficiency (LSCD), a sight-threatening orphan condition most frequently associated with severe chemical or thermal burns. LSCD has historically been treated by transplanting limbal tissue. In 1997, a new treatment, cultured limbal epithelial autografts, was described for unilateral LSCD. In cases of bilateral disease cultured autologous oral mucosa stem cells have been used. The relative efficacy of different cultured tissue procedures is unknown.

METHODS

A protocol was registered with PROSPERO (CRD42017081117). Searches were conducted in 14 databases and 6 conference websites. Two reviewers independently selected studies, conducted data extraction and assessed risk of bias. One reviewer extracted individual patient data (IPD); a second checked extracted data. Data were assessed to determine the feasibility of statistical analysis, with Bayesian synthesis used to estimate improvement achieved by different treatments.

RESULTS

Fifty-two studies were eligible for inclusion (1113 eyes); 41 studies (716 eyes) reported IPD. No evidence was identified on cost-effectiveness. This SR was unable to confirm that any of the types of ex vivo cultured stem cell transplants identified for LSCD treatment were statistically superior when assessed against the outcomes of interest.

CONCLUSIONS

We believe this SR is the first to include IPD analysis of LSCD data. There is no evidence for the superiority of any method of limbal stem cell transplant. Confirmation of the safety and efficacy of this treatment modality is challenging due to heterogeneity within and between the studies identified. Therefore, recommendations for future research are proposed.

Exponentially decaying modes and long-term prediction of sea ice concentration using Koopman mode decomposition

Sea ice cover in the Arctic and Antarctic is an important indicator of changes in the climate, with important environmental, economic and security consequences. The complexity of the spatio-temporal dynamics of sea ice makes it difficult to assess the temporal nature of the changes—e.g. linear or exponential—and their precise geographical loci. In this study, Koopman Mode Decomposition (KMD) is applied to satellite data of sea ice concentration for the Northern and Southern hemispheres to gain insight into the temporal and spatial dynamics of the sea ice behavior and to predict future sea ice behavior. We observe spatial modes corresponding to the mean and annual variation of Arctic and Antarctic sea ice concentration and observe decreases in the mean sea ice concentration from early to later periods, as well as corresponding shifts in the locations that undergo significant annual variation in sea ice concentration. We discover exponentially decaying spatial modes in both hemispheres and discuss their precise spatial extent, and also perform predictions of future sea ice concentration. The Koopman operator-based, data-driven decomposition technique gives insight into spatial and temporal dynamics of sea ice concentration not apparent in traditional approaches.

Koopman Mode Analysis of agent-based models of logistics processes

Modern logistics processes and systems can feature extremely complicated dynamics. Agent Based Modeling is emerging as a powerful modeling tool for design, analysis and control of such logistics systems. However, the complexity of the model itself can be overwhelming and mathematical meta-modeling tools are needed that aggregate information and enable fast and accurate decision making and control system design. Here we present Koopman Mode Analysis (KMA) as such a tool. KMA uncovers exponentially growing, decaying or oscillating collective patterns in dynamical data. We apply the methodology to two problems, both of which exhibit a bifurcation in dynamical behavior, but feature very different dynamics: Medical Treatment Facility (MTF) logistics and ship fueling (SF) logistics. The MTF problem features a transition between efficient operation at low casualty rates and inefficient operation beyond a critical casualty rate, while the SF problem features a transition between short mission life at low initial fuel levels and sustained mission beyond a critical initial fuel level. Both bifurcations are detected by analyzing the spectrum of the associated Koopman operator. Mathematical analysis is provided justifying the use of the Dynamic Mode Decomposition algorithm in punctuated linear decay dynamics that is featured in the SF problem.

A multidisciplinary management approach for patients with Klippel-Trenaunay syndrome and multifetal gestation with successful outcomes

Background

Klippel-Trenaunay syndrome (KTS) is a complex congenital disorder characterized by the classic triad of capillary malformation, venous and lymphatic malformations and limb overgrowth. The incidence of pregnancies affected by KTS is unknown. There is a paucity of literature regarding management and outcomes of affected pregnancies, particularly in multifetal gestations.

Case

We present two cases of pregnancies affected by KTS and multiple gestations. A multidisciplinary approach with hematology, radiology and anesthesia resulted in two successful pregnancies with no adverse neonatal outcomes.

Conclusion

Management of pregnancies affected by KTS and multiple gestations should be personalized with a multi-disciplinary approach to avoid morbidity and improve maternal and neonatal outcomes.

Intra-patient variability in adalimumab drug levels within and between cycles in Crohn's disease

BACKGROUND

Whether therapeutic drug monitoring for adalimumab needs to be performed at trough has not been defined.

AIM

To determine intra-patient adalimumab drug-level variation and to identify modulating patient and disease factors.

METHODS

In this prospective observational study, adult patients with Crohn's disease established on maintenance adalimumab had drug levels measured repeatedly according to pre-defined schedules (visit 1: day 4-6, visit 2: day 7-9, trough: day 13-14) across two consecutive fortnightly cycles. Disease activity was assessed using Harvey-Bradshaw Index, C-reactive protein and faecal calprotectin. For this analysis, trough levels ≥4.9 μg/mL were considered therapeutic.

RESULTS

Nineteen patients underwent 111 evaluations. Mean intra-patient drug levels from paired visits between cycles did not differ (visit1 cycle1: 4.81, cycle2: 5.21 μg/mL, P = 0.24, visit2 cycle1: 4.86, cycle2: 4.82, P = 0.91 and trough cycle1: 3.95, cycle2: 3.95, P = 0.99), irrespective of disease activity. Drug levels were stable over the first 9 days (visit 1-2), but declined to trough by a mean 1.06 and 0.89 μg/mL between visit 1 or 2, respectively (P < 0.001). Models using nontemporal factors (smoking, syringe delivery device) and levels at earlier visits accounted for 66-80% of the variance in trough levels. On receiver-operating curve analysis, thresholds identified in the first 9 days that predicted a therapeutic trough level were similar to the trough threshold itself, with high sensitivity but modest specificity.

CONCLUSION

While therapeutic drug monitoring should be performed at trough, a drug level ≥4.9 μg/mL obtained during the first 9 days predicts a therapeutic trough drug level with reasonable confidence.

The RUDY study platform - a novel approach to patient driven research in rare musculoskeletal diseases

BACKGROUND

Research into rare diseases is becoming more common, with recognition of the significant diagnostic and therapeutic care gaps. Registries are considered a key research methodology to address rare diseases. This report describes the structure of the Rare UK Diseases Study (RUDY) platform that aims to improve research processes and address many of the challenges of carrying out rare musculoskeletal disease research. RUDY is an internet-based platform with online registration, initial verbal consent, online capture of patient reported outcome measures and events within a dynamic consent framework. The database structure, security and governance framework are described.

RESULTS

There have been 380 participants recruited into RUDY with completed questionnaire rates in excess of 50 %. There has been one withdrawal and two participants have amended their consent options.

CONCLUSIONS

The strengths of RUDY include low burden for the clinical team, low research administration costs with high participant recruitment and ease of data collection and access. This platform has the potential to be used as the model for other rare diseases globally.

Making Sense of Bereavement in People with Profound Intellectual and Multiple Disabilities: Carer Perspectives

BACKGROUND

People with intellectual disabilities are thought to have a reduced capacity for understanding death. Drawing on cognitive theory, researchers have suggested that those with profound intellectual and multiple disabilities mainly perceive loss as a mismatch between past and present experiences. However, very little research has considered how carers conceptualize bereavement in relation to this group.

METHOD

Semi-structured interviews obtained responses from seven carers. Transcripts were examined using interpretative phenomenological analysis.

RESULTS

Two superordinate themes emerged: 'difficulty articulating the experience of loss' and 'making sense of bereavement through familiar patterns'.

CONCLUSIONS

Carers conceptualize bereavement primarily in cognitive terms, but also take account of relational factors mediating loss. Implications for training and further research are outlined.

Violent and non-violent crime against adults with severe mental illness

BACKGROUND

Little is known about the relative extent of crime against people with severe mental illness (SMI).

AIMS

To assess the prevalence and impact of crime among people with SMI compared with the general population.

METHOD

A total of 361 psychiatric patients were interviewed using the national crime survey questionnaire, and findings compared with those from 3138 general population controls participating in the contemporaneous national crime survey.

RESULTS

Past-year crime was experienced by 40% of patients v. 14% of controls (adjusted odds ratio (OR) = 2.8, 95% CI 2.0-3.8); and violent assaults by 19% of patients v. 3% of controls (adjusted OR = 5.3, 95% CI 3.1-8.8). Women with SMI had four-, ten- and four-fold increases in the odds of experiencing domestic, community and sexual violence, respectively. Victims with SMI were more likely to report psychosocial morbidity following violence than victims from the general population.

CONCLUSIONS

People with SMI are at greatly increased risk of crime and associated morbidity. Violence prevention policies should be particularly focused on people with SMI.

Domestic and sexual violence against patients with severe mental illness

BACKGROUND

Domestic and sexual violence are significant public health problems but little is known about the extent to which men and women with severe mental illness (SMI) are at risk compared with the general population. We aimed to compare the prevalence and impact of violence against SMI patients and the general population.

METHOD

Three hundred and three randomly recruited psychiatric patients, in contact with community services for ⩾ 1 year, were interviewed using the British Crime Survey domestic/sexual violence questionnaire. Prevalence and correlates of violence in this sample were compared with those from 22 606 general population controls participating in the contemporaneous 2011/12 national crime survey.

RESULTS

Past-year domestic violence was reported by 27% v. 9% of SMI and control women, respectively [odds ratio (OR) adjusted for socio-demographics, aOR 2.7, 95% confidence interval (CI) 1.7-4.0], and by 13% v. 5% of SMI and control men, respectively (aOR 1.6, 95% CI 1.0-2.8). Past-year sexual violence was reported by 10% v. 2.0% of SMI and control women respectively (aOR 2.9, 95% CI 1.4-5.8). Family (non-partner) violence comprised a greater proportion of overall domestic violence among SMI than control victims (63% v. 35%, p < 0.01). Adulthood serious sexual assault led to attempted suicide more often among SMI than control female victims (53% v. 3.4%, p < 0.001).

CONCLUSIONS

Compared to the general population, patients with SMI are at substantially increased risk of domestic and sexual violence, with a relative excess of family violence and adverse health impact following victimization. Psychiatric services, and public health and criminal justice policies, need to address domestic and sexual violence in this at-risk group.

Fostering effective team cooperation and communication: Developing community standards within interdisciplinary cognitive rehabilitation settings

Cognitive rehabilitation is a promising and necessary component of interdisciplinary treatment for brain injured patients, but it remains an area that lacks universal definitions, empirically validated constructs, or standards of practice. This situation leads to difficulties for interdisciplinary teams in cognitive rehabilitation settings, since definitions, conceptions, and labels of cognitive constructs can differ across team members and disciplines. In order to implement effective cognitive rehabilitation in a given setting, it is necessary to establish a set of 'community standards' that will compensate for the lack of universal standards in the broader cognitive rehabilitation landscape. These community standards will improve team functioning by facilitating communication between disciplines and identifying the team's preferred treatment strategies. Such a project was undertaken by a task force at the University of Missouri-Columbia School of Medicine, Rusk Rehabilitation Center. The process of establishing such a task force and the need for establishing community standards are described and outlined.

Reduced denitration activity in peripheral lung of chronic obstructive pulmonary disease

BACKGROUND

Accumulation of nitrated protein is seen in peripheral lung and cells from patients with chronic obstructive pulmonary disease (COPD). Nitrated protein causes abnormal protein function, but the nitration was believed to be an irreversible process. However, there are accumulating evidences that this process is reversible by an active denitration pathway. The aim of this study is to detect denitration activity in protein extracts from peripheral lung tissue of COPD and to compare with those in healthy subjects.

MATERIALS AND METHODS

Peripheral lung tissue from 4 healthy, 4 smokers without COPD, 4 GOLD stage 1 and 4 GOLD stage 2 were used for denitration assay. Denitration activity was determined as reduction of nitro-tyrosine level of nitrated histone protein after incubation with protein extracts from peripheral lung, which was determined by western blotting. In addition, RNA is extracted from peripheral lung of 8 healthy, 7 smoking control, 8 stage 1 and 2 COPD and 10 stage 3 and 4 COPD and nitrate reductase mRNA expression was determined by real time RT-PCR.

RESULTS

Peripheral lung protein extracts from healthy subjects reduced nitro-tyrosine level of nitrated histone. Thus, we were able to show denitration activity in peripheral lungs. The denitration activity was slightly reduced in smoking controls, and significantly reduced in COPD patients. We also showed that the expression of the human homologue of nitrate reductase (chytochrome β2 reductase), a potential candidate of denitrase, was significanty reduced in COPD lung.

CONCLUSION

This study suggests that accumulation of nitrated protein in lung tissue of COPD may, at least in part, be induced by a reduction in denitration activity or nitrate reductase.

Extracellular matrix remodeling of lung alveolar walls in three dimensional space identified using second harmonic generation and multiphoton excitation fluorescence

The structural reorganization of extracellular matrix (ECM) is an important feature of peripheral lung tissue remodeling in chronic obstructive pulmonary disease (COPD). Ordered ECM macromolecules such as the fibril-forming collagens produce second harmonic generation (SHG) signal without the need for any exogenous label, while ECM macromolecules such as the elastin fibers generate MPEF signal due to their endogenous fluorescence characteristics. Both these signals can be captured simultaneously to provide spatially resolved 3D structural reorganization of ECM matrix. In this study, SHG and MPEF microscopy methods were used to examine structural remodeling of the ECM matrix in human lung alveolar walls undergoing severe emphysematous destruction. Flash frozen lung samples removed from two patients undergoing lung transplantation for severe COPD (n=4) were compared to similar samples from an unused donor lung (n=2) that served as a control. The imaging operations were performed directly on these tissue sections at least three different areas. The generated spatially resolved 3D images showed the distribution of collagen and elastin in the alveolar walls. In the case of the control, we found well ordered alveolar walls with a composite type structure made up of collagen bands and relatively fine elastic fibers. In contrast, lung tissues undergoing emphysematous destruction were highly disorganized with significantly increased alveolar wall thickness compared to the control. We conclude that these non-invasive imaging modalities provide spatially resolved 3D images with spectral specificities that are sensitive enough to identity the ECM structural changes associated with emphysematous destruction.

A protein deacetylase SIRT1 is a negative regulator of metalloproteinase-9

Inappropriate elevation of matrix metalloproteinase-9 (MMP9) is reported to be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). The object of this study was to identify the molecular mechanism underlying this increase of MMP9 expression, and here we show that oxidative stress-dependent reduction of a protein deacetylase, SIRT1, known as a putative antiaging enzyme, causes elevation of MMP9 expression. A sirtuin inhibitor, splitomycin, and SIRT1 knockdown by RNA interference led an increase in MMP9 expression in human monocytic U937 cells and in primary sputum macrophages, which was detected by RT-PCR, Western blot, activity assay, and zymography. In fact, the SIRT1 level was significantly decreased in peripheral lungs of patients with COPD, and this increase was inversely correlated with MMP9 expression and MMP9 promoter activation detected by a chromatin immunoprecipitation assay. H(2)O(2) reduced SIRT1 expression and activity in U937 cells; furthermore, cigarette smoke exposure also caused reduction of SIRT1 expression in lung tissue of A/J mice, with concomitant elevation of MMP9. Intranasal treatment of a selective and novel SIRT1 small molecule activator, SRT2172, blocked the increase of MMP9 expression in the lung as well as pulmonary neutrophilia and the reduction in exercise tolerance. Thus, SIRT1 is a negative regulator of MMP9 expression, and SIRT1 activation is implicated as a novel therapeutic approach to treating chronic inflammatory diseases, in which MMP9 is abundant.