Abdominal wall mass resections: single-center closure practices and outcomes following oncologic resections of abdominal wall fascia

PURPOSE

Radical resections for abdominal wall tumors are rare, thus yielding limited data on reconstruction of defects. We describe surgical management and long-term outcomes following radical tumor resection.

METHODS

This was a single-center retrospective review of patients between January 2010 and December 2022. Variables included operative characteristics, wound complications, hernia development, tumor recurrence, and reoperation. A multivariable analysis compared wound morbidity for suture and mesh repairs while adjusting for defect width, fascial closure, and CDC wound class.

RESULTS

120 patients were identified. Mean follow-up was 3.9 ± 3.4 years. Seventy-five (62.5%) of the masses were primary; most commonly desmoid (n = 25) and endometrioma (n = 27). Forty-five masses were metastases. Mean tumor width was 6.2 ± 3.4 cm; mean defect width was 8.1 ± 4.1 cm. Sixty-one patients (50.8%) had mesh placed, with variation in technique. Postoperative CT scans were available for 88 (73.3%) patients. Forty SSOs (33.3%), 11 SSIs (9.2%), and 18 (15%) SSOPIs occurred within 30 days. On multivariable analysis, increased defect width was associated with SSOPI (OR 1.17, p = 0.041) and CDC wound class II-III was associated with SSI (OR 8.38 and 49.1, p < 0.05) and SSOPI (OR 5.77 and 17.4, p < 0.05); mesh was not associated with these outcomes. Seven patients (5.8%) underwent 30-day reoperations and 35 (20.8%) required additional operations after 30 days. Thirteen percent developed abdominal wall (n = 8) or intra-abdominal tumor recurrence (n = 8) requiring reoperation. Twenty-seven (22.5%) patients developed hernias with a mean fascial defect width of 9.8 ± 7.2 cm.

CONCLUSION

Abdominal wall mass resections are morbid, often contaminated cases with high postoperative complication rates. Risks and benefits of mesh implantation should be tailored on an individual basis.

Proceedings of the 2023 Second Annual ASTCT-NMDP ACCESS Initiative Workshop

Here the proceedings from the Second Annual American Society for Transplantation and Cellular Therapy (ASTCT) and National Marrow Donor Program (NMDP) ACCESS Initiative are reviewed to inform the hematopoietic cell transplantation (HCT) and cellular therapy (CT) ecosystem about progress and direction of the collaborative. Highlights from the meeting, including updates on the progress of projects from the Awareness, Poverty, and Racial Inequity Committees, are presented. The ACCESS Initiative continues to evolve and will remain dependent on the HCT/CT ecosystem's continued dedication to reduce barriers and improve outcome disparities for all patients in need of HCT/CT.

Frequency-Dependent Squeezed Vacuum Source for the Advanced Virgo Gravitational-Wave Detector

In this Letter, we present the design and performance of the frequency-dependent squeezed vacuum source that will be used for the broadband quantum noise reduction of the Advanced Virgo Plus gravitational-wave detector in the upcoming observation run. The frequency-dependent squeezed field is generated by a phase rotation of a frequency-independent squeezed state through a 285 m long, high-finesse, near-detuned optical resonator. With about 8.5 dB of generated squeezing, up to 5.6 dB of quantum noise suppression has been measured at high frequency while close to the filter cavity resonance frequency, the intracavity losses limit this value to about 2 dB. Frequency-dependent squeezing is produced with a rotation frequency stability of about 6 Hz rms, which is maintained over the long term. The achieved results fulfill the frequency dependent squeezed vacuum source requirements for Advanced Virgo Plus. With the current squeezing source, considering also the estimated squeezing degradation induced by the interferometer, we expect a reduction of the quantum shot noise and radiation pressure noise of up to 4.5 dB and 2 dB, respectively.

Optimizing Detection of MEC-Mediated Methicillin Resistance in Coagulase Negative Staphylococcus Species

Introduction/Objective

Parenteral therapy for invasive staphylococcal infections often comprises lipo/glycopeptides for methicillin resistant (MR) organisms, with extended spectrum penicillins reserved for those confirmed as methicillin susceptible (MS). While phenotypic antimicrobial susceptibility testing (AST) using cefoxitin has high accuracy for differentiating MR/MS for S. aureus, the same, simple approach does not reliably distinguish resistance among all coagulase negative Staphylococcus species (CoNS). As such, clinicians may work under an assumption that MS CoNS cannot be reliably predicted by laboratories, leading to lipo/glycopeptide therapeutic use for invasive infections caused by both MR and MS isolates. To better inform laboratory practice, this study aimed to establish the accuracy of multiple phenotypic and genotypic tests for differentiation of MR/MS among commonly recovered CoNS species producing invasive infections.

Methods/Case Report

A convenience sample of 155 unique invasive CoNS isolates with historic Vitek 2 and/or disc diffusion (DD) AST results (~50% MR) were retrieved from frozen storage and tested by: (1) cefoxitin and oxacillin DD, (2) a lateral flow immunoassay for PBP2a without beta-lactam induction, and (3) a lab-developed PCR for mecA. A commercial real-time PCR for mecA/C was also employed for a subset of isolates.

Results (if a Case Study enter NA)

A total of 144 isolates belonging to 11 taxa were evaluated by all tests after accounting for missing, non-viable, and incorrectly cataloged isolates. Using PCR mecA/C detection as the reference standard, categorical agreement for MR/MS status was 95.5% (127/133) for original Vitek GP75 results, 98.6% (142/144) for DD interpreted using updated, species-specific CLSI guidelines, and 100% (144/144) for the lateral flow PBP2a assay. Six MR isolates from five different taxa that were repeatedly mecA-negative by lab-developed PCR confirmed as mecA/C-positive by a commercial assay.

Conclusion

Although all methods evaluated distinguish MR/MS CoNS with sufficient accuracy, definitive determination is best achieved using off-label/lab-developed PCR for mec or lateral flow immunoassay for PBP2a.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2  M_{⊙} and 1.0  M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14  yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200]  Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2  M_{⊙}<m_{PBH}<1.0  M_{⊙} is f_{PBH}≡Ω_{PBH}/Ω_{DM}≲6%. This improves existing constraints on primordial black hole abundance by a factor of ∼3. The other is a dissipative dark matter model, in which fermionic dark matter can collapse and form black holes. The upper limit on the fraction of dark matter black holes depends on the minimum mass of the black holes that can be formed: the most constraining result is obtained at M_{min}=1  M_{⊙}, where f_{DBH}≡Ω_{DBH}/Ω_{DM}≲0.003%. These are the first constraints placed on dissipative dark models by subsolar-mass analyses.

Neural dynamics of semantic categorization in semantic variant of primary progressive aphasia

Semantic representations are processed along a posterior-to-anterior gradient reflecting a shift from perceptual (e.g., it has eight legs) to conceptual (e.g., venomous spiders are rare) information. One critical region is the anterior temporal lobe (ATL): patients with semantic variant primary progressive aphasia (svPPA), a clinical syndrome associated with ATL neurodegeneration, manifest a deep loss of semantic knowledge. We test the hypothesis that svPPA patients perform semantic tasks by over-recruiting areas implicated in perceptual processing. We compared MEG recordings of svPPA patients and healthy controls during a categorization task. While behavioral performance did not differ, svPPA patients showed indications of greater activation over bilateral occipital cortices and superior temporal gyrus, and inconsistent engagement of frontal regions. These findings suggest a pervasive reorganization of brain networks in response to ATL neurodegeneration: the loss of this critical hub leads to a dysregulated (semantic) control system, and defective semantic representations are seemingly compensated via enhanced perceptual processing.

263 Airway, Voice and Swallow Outcomes Following Endotracheal Intubation and Mechanical Ventilation For COVID-19 Pneumonitis: Preliminary Results of a Prospective Cohort Study

Introduction

The COVID-19 pandemic has placed exceptional demands on Intensive Care Units (ICU) across the world – particularly requiring patients to be intubated and mechanically ventilated. Laryngeal injury following intubation is a common occurrence, therefore this study aims to analyse airway, voice, and swallow (AVS) outcomes of patients intubated for COVID-19 pneumonitis and compares it to intubated non-COVID-19 respiratory patients and other ICU admissions.

Method

We collected data from inpatient records, and follow-up clinics on intubated adult patients discharged from a tertiary care hospital ICU between 01/03/20 and 30/04/20. Patients were assessed with the AVS Scale, Voice Handicap Index-10 (VHI-10), and Eating Assessment Tool-10 (EAT-10).

Results

86 patients were admitted with COVID-19 pneumonitis, 17 patients were admitted with non-COVID-19 respiratory failure, and 26 patients were admitted with a non-respiratory diagnosis.

The COVID-19 cohort demonstrated higher rates of AVS difficulties (airway 59% vs 44% and 31%, voice 40% vs 19% and 19%, swallow 21% vs 6% and 12%). VHI-10 and EAT-10 scores showed no significant differences between groups.

Conclusions

Patients intubated for COVID-19 pneumonitis reported higher rates of AVS difficulties against non-COVID-19 reasons for intubation. Robust prospective screening protocols are essential to improving patient outcomes by highlighting and therefore managing laryngological sequelae that occur following intubation.

A RAC-GEF network critical for early intestinal tumourigenesis

RAC1 activity is critical for intestinal homeostasis, and is required for hyperproliferation driven by loss of the tumour suppressor gene Apc in the murine intestine. To avoid the impact of direct targeting upon homeostasis, we reasoned that indirect targeting of RAC1 via RAC-GEFs might be effective. Transcriptional profiling of Apc deficient intestinal tissue identified Vav3 and Tiam1 as key targets. Deletion of these indicated that while TIAM1 deficiency could suppress Apc-driven hyperproliferation, it had no impact upon tumourigenesis, while VAV3 deficiency had no effect. Intriguingly, deletion of either gene resulted in upregulation of Vav2, with subsequent targeting of all three (Vav2-/- Vav3-/- Tiam1-/-), profoundly suppressing hyperproliferation, tumourigenesis and RAC1 activity, without impacting normal homeostasis. Critically, the observed RAC-GEF dependency was negated by oncogenic KRAS mutation. Together, these data demonstrate that while targeting RAC-GEF molecules may have therapeutic impact at early stages, this benefit may be lost in late stage disease.

Optimizing the Handling of Invasive Fungal Sinusitis Surgical Specimens

Introduction/Objective

Invasive fungal sinusitis (IFS) is an aggressive disease characterized by invasion of fungal hyphae into tissue/neurovascular bundles. This project assessed the handling of IFS specimens and implemented protocols to improve turnaround time (TAT).

Methods

A retrospective review of cases accessioned with a clinical concern for IFS from 2014-2019 was performed. TAT for each step in the specimen processing was recorded. A flowchart was created using stakeholder interviews and a revised protocol was developed after assessing critical needs. Assessment of interventions was performed following implementation of the new protocol. The protocol will be evaluated by prospective direct case-by-case feedback and after a 6-month interval (projected August/2020). At 6-months, goals are a 24 hours median time between frozen section and sign-out and elimination of outliers (greater than 2 working days).

Results

We identified 53 specimens from 32 patients in the pre-intervention period (36 cases positive for IFS). Median time from frozen section to final sign-out was 28 (5-312) hours. Four areas for improvements were identified:

(1) triaging specimens to different protocols according to arrival time, (2) optimized triaging for available histology processors, (3) standardized GMS ordering, and (4) standardized case delivery/communication with sign-out staff. Interventions include: protocol for processing specimens based on time of day, new histology protocols to expedite GMS performance, an email group for rapid communication with staff pathologists and histology, and a worksheet/checklist to track each case. After implementation of the protocol, 8 cases from 7 patients were received. Median time from frozen section to final sign-out was reduced to 20 (2 – 50) hours.

Conclusion

The protocol for handling IFS specimens became live on 2/1/2020. It has reduced TAT of suspected IFS cases, from a median of 28 hours to 20 hours. The longest interval to sign-out went from312 hours to 50 hours.

Regional and hemispheric susceptibility of the temporal lobe to FTLD-TDP type C pathology

Post-mortem studies show that focal anterior temporal lobe (ATL) neurodegeneration is most often caused by frontotemporal lobar degeneration TDP-43 type C pathology. Clinically, these patients are described with different terms, such as semantic variant primary progressive aphasia (svPPA), semantic dementia (SD), or right temporal variant frontotemporal dementia (FTD) depending on whether the predominant symptoms affect language, semantic knowledge for object or people, or socio-emotional behaviors. ATL atrophy presents with various degrees of lateralization, with right-sided cases considered rarer even though estimation of their prevalence is hampered by the paucity of studies on well-characterized, pathology-proven cohorts. Moreover, it is not clear whether left and right variants show a similar distribution of atrophy within the ATL cross-sectionally and longitudinally. Here we study the largest cohort to-date of pathology-proven TDP-43-C cases diagnosed during life as svPPA, SD or right temporal variant FTD. We analyzed clinical, cognitive, and neuroimaging data from 30 cases, a subset of which was followed longitudinally. Guided by recent structural and functional parcellation studies, we constructed four bilateral ATL regions of interest (ROIs). The computation of an atrophy lateralization index allowed the comparison of atrophy patterns between the two hemispheres. This led to an automatic, imaging-based classification of the cases as left-predominant or right-predominant. We then compared the two groups in terms of regional atrophy patterns within the ATL ROIs (cross-sectionally) and atrophy progression (longitudinally). Results showed that 40% of pathology proven cases of TDP-43-C diagnosed with a temporal variant presented with right-lateralized atrophy. Moreover, the findings of our ATL ROI analysis indicated that, irrespective of atrophy lateralization, atrophy distribution within both ATLs follows a medial-to-lateral gradient. Finally, in both left and right cases, atrophy appeared to progress to the contralateral ATL, and from the anterior temporal pole to posterior temporal and orbitofrontal regions. Taken together, our findings indicate that incipient right predominant ATL atrophy is common in TDP-43-C pathology, and that distribution of damage within the ATLs appears to be the same in left- and right- sided variants. Thus, regardless of differences in clinical phenotype and atrophy lateralization, both temporal variants of FTD should be viewed as a spectrum presentation of the same disease.

Active lifestyles moderate clinical outcomes in autosomal dominant frontotemporal degeneration

INTRODUCTION

Leisure activities impact brain aging and may be prevention targets. We characterized how physical and cognitive activities relate to brain health for the first time in autosomal dominant frontotemporal lobar degeneration (FTLD).

METHODS

A total of 105 mutation carriers (C9orf72/MAPT/GRN) and 69 non-carriers reported current physical and cognitive activities at baseline, and completed longitudinal neurobehavioral assessments and brain magnetic resonance imaging (MRI) scans.

RESULTS

Greater physical and cognitive activities were each associated with an estimated >55% slower clinical decline per year among dominant gene carriers. There was also an interaction between leisure activities and frontotemporal atrophy on cognition in mutation carriers. High-activity carriers with frontotemporal atrophy (-1 standard deviation/year) demonstrated >two-fold better cognitive performances per year compared to their less active peers with comparable atrophy rates.

DISCUSSION

Active lifestyles were associated with less functional decline and moderated brain-to-behavior relationships longitudinally. More active carriers "outperformed" brain volume, commensurate with a cognitive reserve hypothesis. Lifestyle may confer clinical resilience, even in autosomal dominant FTLD.

Unrestricted generation of pure two-qubit states and entanglement diagnosis by single-qubit tomography

We present an experimental proof-of-principle for the generation and detection of pure two-qubit states that have been encoded in degrees of freedom that are common to both classical-light beams and single photons. Our protocol requires performing polarization tomography on a single qubit from a qubit pair. The degree of entanglement in the qubit pair is measured by concurrence, which can be directly extracted from intensity measurements-or photon counting-entering single-qubit polarization tomography.

Orbital Metastasis of Renal Cell Carcinoma Masquerading as Amaurosis Fugax

Renal cell carcinoma (RCC) is the most common malignancy involving the kidney. Only rarely does it metastasize to the eye and orbit, sometimes mimicking other lesions. A 70-year-old woman was referred from neurology because of a right orbital lesion, six months after the start of a neurological investigation because of amaurosis fugax. Six months earlier she had complained of transient visual disturbances in her right eye. After excluding cardiovascular abnormalities and coagulopathies as the source of her complaints, she was diagnosed as having a right senile ptosis. A computed tomography scan, done to complete the workout, detected a right orbital mass. The patient was referred to the oculoplastic unit. A biopsy and then a lateral orbitotomy were performed. Histopathological examination proved it to be a metastatic renal cell carcinoma, seven years after the primary tumor had been diagnosed and treated by nephrectomy.

The characteristics of metastatic renal cell carcinoma are discussed, in view of the rarity of metastasis to the eye and, in particular, to the orbit, and its tendency to masquerade as other lesions or symptoms. In this case it presented as amaurosis fugax before other signs appeared.

A change in Ocular Involvement in a Patient Suffering from Ankylosing Spondylitis and Behçet's Disease

We report a case of a young man suffering from both ankylosing spondylitis and Behçet's disease in whom the character of the ocular involvement changed according to the predominant disease at a given time. When the clinical picture was one of ankylosing spondylitis, only anterior uveitis was observed, while the clinical picture of Behçet's disease occurred with panuveitis and retinal vasculitis. To the best of our knowledge, this is the first report in the English literature of two different patterns of ocular involvement in the same patient with two seronegative arthritides.

Synthetic Patch for Scleral Tissue Loss

We report a case in which traumatic scleral tissue loss was surgically treated by a synthetic patch used in neurosurgical procedures. In the present case the patch served as a permanent solution to scleral loss. The patch is available commercially and easily stored. In the light of our experience, we suggest that this patch material be considered for both urgent and semi-elective scleral patching procedures.

Coexistence of Optic Nerve Head Drusen and Pseudotumor Cerebri: A Clinical Dilemma

The coexistence of optic nerve head drusen and pseudotumor cerebri is a potential clinical problem since diagnosing only one of two clinical abormalities in a patient may delay or prevent the appropriate treatment. To the best of our knowledge, only four cases of such coexistence have been described. We report three cases diagnosed as having both optic nerve head drusen and pseudotumor cerebri and propose possible explanations. The report draws attention to the need for awareness of this potential coexistence in order to assure proper treatment.

Hyperbaric Oxygenation Combined with Nifedipine Treatment for Recent-Onset Retinal Artery Occlusion

We describe the results of early hyperbaric oxygenation combined with nifedipine treatment for central retinal artery occlusion, and explain the results pathophysiologically. We report four cases in which hyperbaric oxygenation therapy was applied in combination with nifedipine, eyeball massage, and glycerol for the treatment of central retinal artery occlusion. In two of the cases in which therapy was started less than 100 minutes after the acute onset of visual loss and one case in which therapy was started during the course of central arterial occlusion, considerable improvement in visual acuity was observed, while in the fourth case in which therapy was started six hours after the acute onset of visual loss, no improvement appeared. We conclude from these results that hyperbaric oxygenation therapy has a beneficial effect on the final visual outcome of central retinal artery occlusion, provided it is applied early enough. Further investigation is needed to fully define the nature and terms of this beneficial effect.

“Silent” Ocular Toxocariasis

We describe an unusual presentation of ocular Toxocara infection. On examination of a 52-year-old asymptomatic male with no previous relevant general or ocular history, a lesion suggestive of a scarred Toxocara worm was found in his right fundus. medical workup revealed normal blood count and blood chemistry. Serologic tests were negative for Toxoplasma and Echinococcus and in 1:4 dilution were positive for Toxocara. The patient appeared to have a subclinical Toxocara infection, resulting in the present picture.

Evaluation of a TB infection control implementation initiative in out-patient HIV clinics in Zambia and Botswana

SETTING

Out-patient human immunodeficiency virus (HIV) care and treatment clinics in Zambia and Botswana, countries with a high burden of HIV and TB infection.

OBJECTIVE

To develop a tuberculosis infection control (TB IC) training and implementation package and evaluate the implementation of TB IC activities in facilities implementing the package.

DESIGN

Prospective program evaluation of a TB IC training and implementation package using a standardized facility risk assessment tool, qualitative interviews with facility health care workers and measures of pre- and post-test performance.

RESULTS

A composite measure of facility performance in TB IC improved from 32% at baseline to 50% at 1 year among eight facilities in Zambia, and from 27% to 80% at 6 months among 10 facilities in Botswana. Although there was marked improvement in indicators of managerial, administrative and environmental controls, key ongoing challenges remained in ensuring access to personal protective equipment and implementing TB screening in health care workers.

CONCLUSION

TB IC activities at out-patient HIV clinics in Zambia and Botswana improved after training using the implementation package. Continued infrastructure support, as well as monitoring and evaluation, are needed to support the scale-up and sustainability of TB IC programs in facilities in low-resource countries.

Is "Learning" episodic memory? Distinct cognitive and neuroanatomic correlates of immediate recall during learning trials in neurologically normal aging and neurodegenerative cohorts

Although commonly interpreted as a marker of episodic memory during neuropsychological exams, relatively little is known regarding the neurobehavior of "total learning" immediate recall scores. Medial temporal lobes are clearly associated with delayed recall performances, yet immediate recall may necessitate networks beyond traditional episodic memory. We aimed to operationalize cognitive and neuroanatomic correlates of total immediate recall in several aging syndromes. Demographically-matched neurologically normal adults (n=91), individuals with Alzheimer's disease (n=566), logopenic variant primary progressive aphasia (PPA) (n=34), behavioral variant frontotemporal dementia (n=97), semantic variant PPA (n=71), or nonfluent/agrammatic variant PPA (n=39) completed a neurocognitive battery, including the CVLT-Short Form trials 1-4 Total Immediate Recall; a majority subset also completed a brain MRI. Regressions covaried for age and sex, and MMSE in cognitive and total intracranial volume in neuroanatomic models. Neurologically normal adults demonstrated a heterogeneous pattern of cognitive associations with total immediate recall (executive, speed, delayed recall), such that no singular cognitive or neuroanatomic correlate uniquely predicted performance. Within the clinical cohorts, there were syndrome-specific cognitive and neural associations with total immediate recall; e.g., semantic processing was the strongest cognitive correlate in svPPA (partial r=0.41), while frontal volumes was the only meaningful neural correlate in bvFTD (partial r=0.20). Medial temporal lobes were not independently associated with total immediate recall in any group (ps>0.05). Multiple neurobehavioral systems are associated with "total learning" immediate recall scores that importantly differ across distinct clinical syndromes. Conventional memory networks may not be sufficient or even importantly contribute to total immediate recall in many syndromes. Interpreting learning scores as equivalent to episodic memory may be erroneous.

Barriers and facilitators experienced in collaborative prospective research in orthopaedic oncology: A qualitative study

Objectives

As tumours of bone and soft tissue are rare, multicentre prospective collaboration is essential for meaningful research and evidence-based advances in patient care. The aim of this study was to identify barriers and facilitators encountered in large-scale collaborative research by orthopaedic oncological surgeons involved or interested in prospective multicentre collaboration.

Methods

All surgeons who were involved, or had expressed an interest, in the ongoing Prophylactic Antibiotic Regimens in Tumour Surgery (PARITY) trial were invited to participate in a focus group to discuss their experiences with collaborative research in this area. The discussion was digitally recorded, transcribed and anonymised. The transcript was analysed qualitatively, using an analytic approach which aims to organise the data in the language of the participants with little theoretical interpretation.

Results

The 13 surgeons who participated in the discussion represented orthopaedic oncology practices from seven countries (Argentina, Brazil, Italy, Spain, Denmark, United States and Canada). Four categories and associated themes emerged from the discussion: the need for collaboration in the field of orthopaedic oncology due to the rarity of the tumours and the need for high level evidence to guide treatment; motivational factors for participating in collaborative research including establishing proof of principle, learning opportunity, answering a relevant research question and being part of a collaborative research community; barriers to participation including funding, personal barriers, institutional barriers, trial barriers, and administrative barriers and facilitators for participation including institutional facilitators, leadership, authorship, trial set-up, and the support of centralised study coordination.

Conclusions

Orthopaedic surgeons involved in an ongoing international randomised controlled trial (RCT) were motivated by many factors to participate. There were a number of barriers to and facilitators for their participation. There was a collective sense of fatigue experienced in overcoming these barriers, which was mirrored by a strong collective sense of the importance of, and need for, collaborative research in this field. The experiences were described as essential educational first steps to advance collaborative studies in this area. Knowledge gained from this study will inform the development of future large-scale collaborative research projects in orthopaedic oncology.

Cite this article: J. S. Rendon, M. Swinton, N. Bernthal, M. Boffano, T. Damron, N. Evaniew, P. Ferguson, M. Galli Serra, W. Hettwer, P. McKay, B. Miller, L. Nystrom, W. Parizzia, P. Schneider, A. Spiguel, R. Vélez, K. Weiss, J. P. Zumárraga, M. Ghert. Barriers and facilitators experienced in collaborative prospective research in orthopaedic oncology: A qualitative study. Bone Joint Res 2017;6:–314. DOI: 10.1302/2046-3758.65.BJR-2016-0192.R1.

Quantifying the accretion of hyperphosphorylated tau in the locus coeruleus and dorsal raphe nucleus: the pathological building blocks of early Alzheimer's disease

AIMS

Hyperphosphorylated tau neuronal cytoplasmic inclusions (ht-NCI) are the best protein correlate of clinical decline in Alzheimer's disease (AD). Qualitative evidence identifies ht-NCI accumulating in the isodendritic core before the entorhinal cortex. Here, we used unbiased stereology to quantify ht-NCI burden in the locus coeruleus (LC) and dorsal raphe nucleus (DRN), aiming to characterize the impact of AD pathology in these nuclei with a focus on early stages.

METHODS

We utilized unbiased stereology in a sample of 48 well-characterized subjects enriched for controls and early AD stages. ht-NCI counts were estimated in 60-μm-thick sections immunostained for p-tau throughout LC and DRN. Data were integrated with unbiased estimates of LC and DRN neuronal population for a subset of cases.

RESULTS

In Braak stage 0, 7.9% and 2.6% of neurons in LC and DRN, respectively, harbour ht-NCIs. Although the number of ht-NCI+ neurons significantly increased by about 1.9× between Braak stages 0 to I in LC (P = 0.02), we failed to detect any significant difference between Braak stage I and II. Also, the number of ht-NCI+ neurons remained stable in DRN between all stages 0 and II. Finally, the differential susceptibility to tau inclusions among nuclear subdivisions was more notable in LC than in DRN.

CONCLUSIONS

LC and DRN neurons exhibited ht-NCI during AD precortical stages. The ht-NCI increases along AD progression on both nuclei, but quantitative changes in LC precede DRN changes.