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Adequate post-intubation sedation and analgesia (PISA) practices are important in the pre-hospital setting where vibration and noise of the transport vehicle may contribute to anxiety and pain in the patient. These practices are poorly described in the pre-hospital setting. This study aims to describe the current pre-hospital PISA practices in a private South African (SA) emergency medical service. Patient report forms (PRF) of intubated patients between 1 Jan 2017 and 31 Dec 2017 from a private ambulance service were reviewed. The data were analysed descriptively. Correlations between receiving PISA and various predictive factors were calculated with Spearman's Rank correlations and differences between intubation method were calculated with independent t-tests and Mann-Whitney U tests. A binomial regression model was used to determine predictive factors of receiving PISA. The number of PRFs included for analysis was 437. Of these, 69% of patients received PISA. The estimated time from intubation to 1st PISA ranged from 9 to 12 min. There were statistically significantly more PISA interventions in patients who had received Rocuronium (p < 0.01). There was weak correlation between the number of interventions and the mean arterial pressure, (p < 0.05) and with the transport time to hospital (r s = -0.77, p < 0.01). Sixty nine percent of patients who are intubated pre-hospital receive PISA, which leaves up to 30% without PISA. The time to 1st PISA appears to be shorter in the SA setting. There is an increased number of interventions in the patients who received Rocuronium, which may indicate practitioners being mindful of wakeful paralysis. Patients intubated with RSI are more likely to receive PISA and practitioners take the blood pressure prior to and after intubation into account when administering PISA. Longer transport times attribute to patients receiving more PISA interventions. [ABSTRACT FROM AUTHOR]

Acute myocardial infarction (AMI) is a time sensitive emergency. In resource limited settings, prompt identification and management of patients experiencing AMI in the pre-hospital setting may minimise the negative consequences associated with overburdened emergency medical and hospital services. Expedited care thus, in part, relies on the dispatch of appropriate pre-hospital medical providers by emergency medical dispatchers. Identification of these patients in call centres is challenging due to a highly diverse South African society, with multiple languages, cultures, and levels of education. The aim of this study was therefore, to describe the terms used by members of the South African public when calling for an ambulance for patients suffering an AMI. In this qualitative study, we performed content analysis to identify keywords and phrases that callers used to describe patients who were experiencing an advanced life support (ALS) paramedic-diagnosed AMI. Using the unique case reference number of randomly selected AMI cases, original voice recordings between the caller and emergency medical dispatcher at the time of the emergency were extracted and transcribed verbatim. Descriptors of AMI were identified, coded and categorised using content analysis, and quantified. Of the 50 randomly selected calls analysed, 5 were not conducted in English. The descriptors used by callers were found to fall into three categories; Pain: Thorax , No pain: Thorax and Ill- health. The code that occurred most often was no pain, heart related (n = 16; 23.2%), followed by the code describing pain in the chest (n = 15; 21.7%). South African callers use a consistent set of descriptors when requesting an ambulance for a patient experiencing an AMI. The most common of these are non-pain descriptors related to the heart. These descriptors may ultimately be used in developing validated algorithms to assist dispatch decisions. In this way, we hope to expedite the correct level of care to these time- critical patients and prevent the unnecessary dispatch of limitedly available ALS paramedics to inappropriate cases. [ABSTRACT FROM AUTHOR]

There is a need for better information exchange between primary and secondary care healthcare professionals in cancer patients with limited life expectancy, most of whom prefer to be at home but are admitted frequently at the end of life (EoL). We conducted a file search to assess this among our patients and developed a discharge pathway to decrease readmission rate and dying in hospital. We performed an in-depth file search among 150 patients who died within 1 month after hospital admission (July 2013 to January 2014); 60 were admitted once, and 90 were admitted twice or more. Mean time spent in hospital at EoL was 12 days; 37% died in hospital, and 49% died at home. We included 31 admitted cancer patients at the EoL in whom home-discharge was planned for the intervention (February 2017 to December 2018). Median survival was 24 days, time spent in hospital decreased from 15.5 to 2.5 days, and number of readmissions fell from 2.8 to 0.57. One patient (3.1%) died in hospital, and 77% died at home. And 78% of general practitioners found the provided information useful. A proactive discharge pathway may reduce hospital readmission rates, time spent in hospital, and in-hospital death. Ever more patients with complex care needs at the EoL are being discharged early. Being informed about patients' wishes, preferences, and treatment options for symptom management at home is essential for doctors and nurses in primary care. A systematic discharge pathway can be useful for information transfer when admitted patients are discharged home. [ABSTRACT FROM AUTHOR]

Objectives: It is disputed whether arthroscopic meniscectomy is an (cost-) effective treatment for degenerative meniscus tears in day-to-day clinical practice. The objective of this study was to assess the cost-effectiveness of arthroscopic meniscectomy in subjects with knee osteoarthritis, in routine clinical practice, while taking into account the increased risk for future knee replacement surgery. We compared cost-effectiveness of arthroscopic meniscectomy compared to no surgery.Design: We used a state transition (Markov) simulation model to evaluate the cost-effectiveness of arthroscopic meniscectomy compared to no surgery in subjects with knee osteoarthritis (age range 45-79 years). Data used in the preparation of the current study were obtained from the Osteoarthritis Initiative (AOI) database. We applied a 9 years' time horizon (which is equal to the current OAI study follow up period), and evaluated cost-effectiveness from a societal perspective. The main outcome measure was the incremental cost-effectiveness ratio (Euros per quality adjusted life-year (QALY) gained).Results: Arthroscopic meniscectomy was associated with 8.09 (SD ± 0.07) QALYs at a cost of € 21,345 (SD ± 841), whereas the no surgery was associated with 8.05 (SD ± 0.07) QALYs at a cost of € 16,284 (SD ± 855). For arthroscopic meniscectomy, the incremental cost per QALY gained was € 150,754.Conclusions: In day-to-day clinical practice, arthroscopic meniscectomy in subjects with knee osteoarthritis is associated with € 150,754 per QALY gained, which exceeds the generally accepted willingness to pay (WTP) (range € 20,000-€ 80,000). [ABSTRACT FROM AUTHOR]

Ecosystem resilience to climate change is contingent on post-disturbance plant regeneration. Sparse gymnosperm regeneration has been documented in subalpine forests following recent wildfires and compounded disturbances, both of which are increasing. In the US Intermountain West, this may cause a shift to non-forest in some areas, but other forests may demonstrate adaptive resilience through increased quaking aspen ( Populus tremuloides Michx . ) dominance. However, this potential depends on ill-defined constraints of aspen sexual regeneration under current climate. We created an ensemble of species distribution models for aspen seedling distribution following severe wildfire to define constraints on establishment. We recorded P. tremuloides seedling locations across a post-fire, post-blowdown landscape. We used 3 algorithms (Mahalanobis Typicalities, Multilayer Perceptron Artificial Neural Network, and MaxEnt) to create spatial distribution models for aspen seedlings and to define constraints. Each model performed with high accuracy and was incorporated into an ensemble model, which performed with the highest overall accuracy of all the models. Populus tremuloides seedling distribution is constrained primarily by proximity to unburned aspen forest and annual temperature ranges, and secondarily by light availability, summer precipitation, and fire severity. Based on model predictions and validation data, P. tremuloides seedling regeneration is viable throughout 54% of the post-fire landscape, 97% of which was previously conifer-dominated. Aspen are less susceptible to many climatically-sensitive disturbances (e.g. fire, beetle outbreak, wind disturbance), thus, aspen expansion represents an important adaptation to climate change. Continued aspen expansion into post-disturbance landscapes through sexual reproduction at the level suggested by these results would represent an important adaptation to climate change and would confer adaptive forest resilience by maintaining forest cover, but would also alter future disturbance regimes, biodiversity, and ecosystem services. [ABSTRACT FROM AUTHOR]

Molecular technologies are more frequently applied in Antarctic ecosystem research and the growing amount of sequence-based information available in databases adds a new dimension to understanding the response of Antarctic organisms and communities to environmental change. We apply molecular techniques, including fingerprinting, and amplicon and metagenome sequencing, to understand biodiversity and phylogeography to resolve adaptive processes in an Antarctic coastal ecosystem from microbial to macrobenthic organisms and communities. Interpretation of the molecular data is not only achieved by their combination with classical methods (pigment analyses or microscopy), but furthermore by combining molecular with environmental data (e.g., sediment characteristics, biogeochemistry or oceanography) in space and over time. The studies form part of a long-term ecosystem investigation in Potter Cove on King-George Island, Antarctica, in which we follow the effects of rapid retreat of the local glacier on the cove ecosystem. We formulate and encourage new approaches to integrate molecular tools into Antarctic ecosystem research, environmental conservation actions, and polar ocean observatories. [ABSTRACT FROM AUTHOR]

Objective: The primary objective was to assess whether patients with knee osteoarthritis and whom undergo arthroscopic meniscectomy have an increased risk for future knee replacement surgery.Design: Data used were obtained from the Osteoarthritis Initiative (OAI) study.Setting: Participants were enrolled, in four clinical centers, between February 2004 and May 2006 and were followed up on an annual basis up to and including 108-months from enrollment.Participants: 4674 participants (58.4% female), aged 45-79, of all ethnic groups, who had, and those who were at high risk for developing, symptomatic knee osteoarthritis were included, of which 3337 (71.4%) were included in the final follow up visit.Main Outcome Measures: Hazard ratio of knee replacement surgery for participants who underwent arthroscopic meniscectomy during follow up compared to propensity score matched participants who did not undergo arthroscopic meniscectomy during follow up.Results: 335 participants underwent arthroscopic meniscectomy during follow up, of which 63 (18.8%) underwent knee replacement surgery in the same knee. Of the 335 propensity score matched participants 38 (11.1%) underwent knee replacement surgery during follow up. Results from the Cox-proportional hazards model demonstrated that the hazard ratio of knee replacement surgery was 3.03 (95% CI (1.67-5.26)) for participants who underwent arthroscopic meniscectomy relative to the propensity score matched participants who did not undergo arthroscopic meniscectomy.Conclusions: In patients with knee osteoarthritis arthroscopic knee surgery with meniscectomy is associated with a three fold increase in the risk for future knee replacement surgery. [ABSTRACT FROM AUTHOR]

Objective: Recently it was shown that loading of articular cartilage explants activates TGFβ signaling. Here we investigated if in vivo chondrocytes express permanently high TGFβ signaling, and the consequence of the loss of compressive loading-mediated TGFβ signaling on chondrocyte function and phenotype.Method: Bovine articular cartilage explants were collected within 10 min post mortem and stained immediately and after 30, 60 and 360 min for phosphorylated-Smad2, indicating active TGFβ signaling. Explants were unloaded for 48 h and subsequently repeatedly loaded with a compressive load of 3 MPa. In addition, explants were cultured unloaded for 2 weeks and the effect of loading or exogenous TGFβ on proteoglycan level and chondrocyte phenotype (Col10a1 mRNA expression) was analyzed.Results: Unloading of articular cartilage results in rapid loss of TGFβ signaling while subsequent compressive loading swiftly restored this. Loading and exogenous TGFβ enhanced expression of TGFβ1 and ALK5. Unloading of explants for 2 weeks resulted in proteoglycan loss and increased Col10a1 expression. Both loading and exogenous TGFβ inhibited elevated Col10a1 expression but not proteoglycan loss.Conclusion: Our data might imply that in vivo regular physiological loading of articular cartilage leads to enduring TGFβ signaling and TGFβ-induced gene expression. We propose a hypothetical model in which loading activates a self-perpetuating system that prevents hypertrophic differentiation of chondrocytes and is crucial for cartilage homeostasis. [ABSTRACT FROM AUTHOR]

Meniscus tears are one of the most commonly occurring injuries of the knee joint. Current meniscus repair techniques are challenging and do not bring fully satisfactory results. Tissue adhesives are a promising alternative, since they are easy to apply and cause minimal tissue trauma. In this study, a series of amphiphilic copolymers based on polyethylene glycol, trimethylene carbonate and citric acid were synthesized and subsequently end-functionalized with hexamethylene diisocyanate to form reactive adhesive materials. The shear adhesive strength of the networks to bovine meniscus tissue measured in a lap-shear adhesion test ranged between 20 and 80 kPa, which was better than for fibrin glue (10 kPa). The elastic modulus of the networks depended on composition and was in the same range as that of human meniscus. Cell compatibility was assessed using Alamar Blue staining after incubation of the bovine meniscus cells with different concentrations of the glues for 7 days. Cell viability was not affected after adding up to 3 mg of the adhesive/mL of medium. The proposed materials are suitable candidates to be used as resorbable tissue adhesives for meniscus repair. They have excellent mechanical and adhesive properties that can be adjusted by varying the composition of the copolymers. Statement of Significance Meniscal tears often occur and current treatment strategies do not bring fully satisfactory results. Use of biodegradable tissue adhesives would be an interesting option, but currently available adhesives are not suited due to toxicity or poor mechanical properties. Here, we describe the development of novel biodegradable, hyper-branched, adhesive copolymers. These adhesives cure upon contact with water forming flexible networks. Their adhesion to bovine meniscus tissue was significantly better than that of clinically used fibrin glue. The tensile properties of the cured networks were in the same range of values of the human meniscus. When physiologically relevant amounts were added to cells in culture, not toxic effects were observed. Therefore, the proposed materials are interesting resorbable tissue adhesives for meniscus repair. [ABSTRACT FROM AUTHOR]

The study aims to unravel the variability of Dinophysis spp. and their alleged toxins in conjunction with environmental drivers in Ambon Bay. Phytoplankton samples, lipophilic toxins and physiochemical water properties were analysed during a 1.5-year period. Three Dinophysis species (D. miles , D. caudata , and D. acuminata) were found in plankton samples, of which D. miles was the most abundant and persistently occurring species. Pectenotoxin-2 (PTX2) and its secoacid (PTX2sa) were detected throughout, and PTX2sa levels strongly correlated with D. miles cell abundance. The toxin showed a positive correlation with temperature, which may suggest that D. miles cells contain rather constant PTX2sa during warmer months. Dissolved nitrate concentrations were found to play a major role in regulating cell abundances and toxin levels. This study adds adequate information regarding marine biotoxins and potentially toxic species for future Harmful Algal Bloom management in Ambon and Indonesia at large. • Dinophysis miles is the most abundant species and found persistently in Ambon Bay. • Pectenotoxin-2 and its secoacid are detected and have strong correlations with Dinophysis miles cells. • The pectenotoxin-2 secoacid is likely produced during the dry season with high temperature levels. • Nitrate is the main factor controlling both Dinophysis miles cells and the toxins. [ABSTRACT FROM AUTHOR]

Objective: Mechanical signals control key cellular processes in articular cartilage. Previously we have shown that mechanical compression is an important ALK5/Smad2/3P activator in cartilage explants. However, age-related changes in the cartilage are known to affect tissue mechanosensitivity and also ALK5/Smad2/3P signaling. We have investigated whether ageing of cartilage is associated with an altered response to mechanical compression.Design: Articular cartilage explants of two different age groups (young-6-36 months old, aged-6 - 13 years old) were subjected to dynamic mechanical compression with 3 MPa (physiological) or 12 MPa (excessive) load. Subsequently, essential cartilage extracellular matrix (ECM) components and tissue growth factors gene expression was measured in young and aged cartilage by QPCR. Furthermore, the ability of young and aged cartilage, to activate the Smad2/3P signaling in response to compression was analyzed and compared. This was done by immunohistochemical (IH) Smad2P detection and Smad3-responsive gene expression analysis.Results: Aged cartilage showed a highly reduced capacity for mechanically-mediated activation of Smad2/3P signaling when compared to young cartilage. Compression of aged cartilage, induced collagen type II (Col2a1) and fibronectin (Fn1) expression to a far lesser extent than in young cartilage. Additionally, in aged cartilage no mechanically mediated up-regulation of bone morphogenetic protein 2 (Bmp2) and connective tissue growth factor (Ctgf) was observed.Conclusions: We identified age-related changes in cellular responses to mechanical stimulation of articular cartilage. We propose that these changes might be associated with age-related alterations in cartilage functioning and can underlie mechanisms for development of age-related cartilage diseases like osteoarthritis (OA). [ABSTRACT FROM AUTHOR]

Objective: Transforming growth factor beta (TGF-β) in articular cartilage can signal via two routes, the ALK5/Smad2/3P and the ALK1/Smad1/5/8P route, the first being protective and the latter favoring chondrocyte terminal differentiation. Since biomechanical factors are known to play an essential role in osteoarthritis (OA) initiation and progression, we investigated if excessive mechanical compression can alter TGF-β signaling in cartilage shifting it from ALK5/Smad2/3P to ALK1/Smad1/5/8P pathway, favoring terminal differentiation of chondrocytes. Design: Articular cartilage explants were harvested from bovine metacarpophalangeal joints. After equilibration, explants were subjected to unconfined dynamic mechanical compression (1 Hz) with 3 MPa (physiological) or 12 MPa (excessive) stress. After different time intervals samples were frozen and mRNA levels of selected genes were examined using real-time polymerase chain reaction. Results: In articular cartilage compressed with 3 MPa and also 12 MPa stress the expression of Smad2/3P responsive genes bSerpine1, bSmad7 and bAlk5 was up-regulated, whereas the expression of Smad1/5/8P responsive gene bId1 was down-regulated. Furthermore, the expression of bTgfb1 was significantly up-regulated in both compression groups. When ALK5/Smad2/3P pathway was blocked with a selective ALK4/5/7 inhibitor, the effect of excessive mechanical compression on bSmad7 and bAlk5 expression was prevented. Conclusions: Here we show that excessive mechanical compression alone is not able to shift TGF-β signaling toward the ALK1/Smad1/5/8P pathway. In contrast, we show that mechanical compression not only with physiological but also with excessive stress can activate Smad2/3P signaling, which is known to be protective for articular cartilage and to block chondrocyte terminal differentiation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Carbon stocks may be maintained despite ecosystem shift. [•] Resilience of an ecosystem service not necessarily tied to the existing ecosystem. [•] Climate change has a large effect on carbon stocks. [•] Facilitated migration may be required to maintain certain ecosystem services. [ABSTRACT FROM AUTHOR]

Abstract: Disturbance interactions are of great interest in ecology due to their potential to cause non-linear, unexpected results. Increases in disturbance frequency and intensity as a result of climate change increase the need for better conceptual and mechanistic understanding of ecosystem response to compounded perturbations. Impacts on structural elements of ecosystems, such as tree species, are particularly important, as changes in these species’ populations, frequencies, and distributions may influence landscape functioning for extended periods of time. This study investigated the impact of three overlapping disturbances common to western US forests (wind, logging, and fire) on three dominant tree species: Lodgepole pine, Engelmann spruce, and quaking aspen. Ninety-nine study plots were examined across a gradient of interaction severities from a 1997 blowdown, subsequent salvage logging, and a 2002 fire in a Rocky Mountain subalpine forest. Regeneration of dominant species was analyzed in the context of disturbance history and species-specific disturbance response strategies. Results indicated that species are differentially affected by disturbance interactions. Lodgepole pine is highly sensitive to both previous disturbances and their severities, whereas spruce and aspen are insensitive to disturbance history, although both showed higher recruitment levels in three-disturbance environments. Disturbance types, combinations, and specific resilience mechanisms appear to be more important than number of disturbances. Disturbance interactions were not necessarily additive, and in some cases, three disturbances were less severe than two. As a result of long-distance dispersal, aspen seems likely to greatly increase in dominance across the landscape. Species-specific responses are generalized through their individual response strategies, with specialized responses being less resilient to multiple disturbances than generic seed dispersal strategies. Differential responses by structural tree species will likely drive an increase in future landscape heterogeneity and potential decreases in future landscape resilience to fire. [Copyright &y& Elsevier]

Abstract: The long-term survival of the cementless Spotorno (CLS) femoral component (Zimmer Inc, Warsaw, USA) was evaluated in a consecutive series of 85 patients (100 hips) less than 50 years of age. The mean follow-up was 12.3 years. Two patients (3 hips) were lost to follow-up, and 3 (4 hips) died. The survival rate of the CLS stem was 96.9% (confidence interval [CI], 93.6%-100%) after 13 years based on revision of the stem for any reason. The survival of the stem with revision for aseptic loosening as the end point was 97.9% (CI, 95.1%-100%) at 13 years. The mean Harris hip score at time of follow-up was 94. The long-term survival of the CLS stem is excellent in patients less than 50 years of age. [Copyright &y& Elsevier]

Understanding the spatio-temporal characteristics of water storage changes is crucial for Lake Chad, a basin facing a range of challenges in water management caused by anthropogenic impacts as well as climate variability. In addition to this, scarcity of in situ measurements combined with scale limitations of traditional methods used in its hydrological characterization further makes it hard to assess and manage this vital water resource. The primary objective of this study is to apply remotely sensed and modeled data over the lake area in order to investigate the inter-annual and seasonal terrestrial water storage changes within the lake area and its effect on the lake's surface water. The data used in this study includes; monthly gravity field data from the Gravity Recovery and Climate Experiment (GRACE) mission from which water storage trends within the basin were determined, Rainfall data from the Tropical Rainfall Measuring Mission (TRMM) shows an increase in seasonal pattern of rainfall in this area. This study, covers a period from 2003-2013. Results show that GRACE Terrestrial Water Storage within the basin has been somewhat stable with the highest averaged values at 0.69 cm/year occurring in 2012. Correlation analysis indicated a time lag of about a month exists between TWS and rainfall. To understand the possible causes and effects these changes has on the surface water of the lake, investigations using Landsat imagery are underway. These results could serve as an insight on the availability of water resources in the Lake Chad Basin and could also provide baseline data which could be used to monitor the lake for current and future management purposes. [ABSTRACT FROM AUTHOR]

We test the safety of fluoxetine post-ischemic stroke in Sub-Saharan Africa. Adults with acute ischemic stroke, seen <14 days since new-onset motor deficits, were enrolled from 11/2019– 10/2020 in a single-arm, open-label phase II trial of daily fluoxetine 20mg for 90 days at Muhimbili National Hospital, Dar es Salaam, Tanzania. The primary outcome was safety with secondary outcomes of medication adherence and tolerability. 34 patients were enrolled (11 female; mean age 52.2 years, 65% <60 years old; mean 3.3 days since symptom onset). Participants had hypertension (74%), diabetes (18%), and smoked cigarettes (18%). The median National Institutes of Health Stroke Scale score at enrollment was 10.5. The median Fugl Meyer Motor Scale score was 28.5 (upper extremity 8, lower extremity 17.5). 32/34 participants (91%) survived to 90 days. There were 8 serious and 2 non-serious adverse events. Deaths occurred due to gastrointestinal illness with low serum sodium (nadir 120 mmol/L) with seizure and gastrointestinal bleed from gastric cancer. The average sodium level at 90 days was 139 mmol/L (range 133–146) and alanine transaminase was 28 U/L (range 10–134). Fluoxetine adherence was 96%. The median mRS among survivors at 90 days was 2 and Fugl Meyer Motor Scale score was 66 (upper extremity 40, lower extremity 27). Median 90-day Patient Health Questionnaire-9 and Montgomery-Åsberg scores were 3.5 and 4 (minimal depression). Fluoxetine administration for 90 days post-stroke in Sub-Saharan Africa was generally safe and well-tolerated, but comorbid illness presentations were fatal in 2/34 cases, even after careful participant selection. [ABSTRACT FROM AUTHOR]

The article focuses on meniscectomy, surgical repair of the meniscus of the knee joint. Loss of mensicus tissue can lead to osteoarthritis. Research is examined on the use of synthetic substitutes created for mensicus tissue created by tissue engineering to treat resected meniscus and avoid meniscectomy.

Meniscus lesions are among the most frequent injuries in orthopaedic practice and they will inevitably lead to degeneration of the knee articular cartilage. The fibro-cartilage-like tissue of the meniscus is notorious for its limited regenerative capacity. Tissue engineering could offer new treatment modalities for repair of meniscus tears and eventually will enable the replacement of a whole meniscus by a tissue-engineered construct.Many questions remain to be answered before the final goal, a tissue-engineered meniscus is available for clinical implementation. These questions are related to the selection of an optimal cell type, the source of the cells, the need to use growth factor(s) and the type of scaffold that can be used for stimulation of differentiation of cells into tissues with optimal phenotypes. Particularly in a loaded, highly complex environment of the knee, optimal mechanical properties of such a scaffold seem to be of utmost importance.With respect to cells, autologous meniscus cells seems the optimal cell source for tissue engineering of meniscus tissue, but their availability is limited. Therefore research should be stimulated to investigate the suitability of other cell sources for the creation of meniscus tissue. Bone marrow stroma cells could be useful since it is well known that they can differentiate into bone and cartilage cells. With respect to growth factors, TGF-β could be a suitable growth factor to stimulate cells into a fibroblastic phenotype but the problems of TGF-β introduced into a joint environment should then be solved. Polyurethane scaffolds with optimal mechanical properties and with optimal interconnective macro-porosity have been shown to facilitate ingrowth and differentiation of tissue into fibro-cartilage. However, even these materials cannot prevent cartilage degeneration in animal models. Surface modification and/or seeding of cells into the scaffolds before implantation may offer a solution for this problem in the future.This review focuses on a number of specific questions; what is the status of the development of procedures for lesion healing and how far are we from replacing the entire meniscus by a (tissue-engineered) prosthesis. Subquestions related to the type of scaffold used are: is the degree of tissue ingrowth and differentiation related to the initial mechanical properties and if so, what is the influence of those properties on the subsequent remodelling of the tissue into fibro-cartilage; what is the ideal pore geometry and what is the optimal degradation period to allow biological remodelling of the tissue in the scaffold. Finally, we will finish with our latest results of the effect of tear reconstruction and the insertion of prostheses on articular cartilage degradation. [Copyright &y& Elsevier]

Impacted morsellized bone grafts are clinically successful to restore bony defects after failed total hip arthroplasties. The incorporation process seems to be dependent on the location where the reconstruction is performed, which suggests that load could play a role. In this study, we hypothesised that, as in fracture healing, physiological loading has a stimulatory effect on the process of early bone graft incorporation. To test this hypothesis we created a standardised defect in the distal femur of twelve goats. Allograft bone chips were impacted into the defect and a subcutaneous pressure implant was screwed in. With this implant the graft can be loaded under controlled circumstances. Six goats were subjected to a daily loading regime of 3 MPa, the other six were non-loaded. After five weeks the bone mineral density was measured with peripheral quantitative computer tomography. Thereafter, routine histology and histomorphometry were carried out. Bone mineral density was not affected by load. Histology revealed microscopic evidence of bone graft incorporation, which proceeded in a similar way in both loaded and non-loaded specimens. New bone was formed free in the stroma or on graft remnants after osteoclastic resorption of the graft. Only the area of active incorporating bone graft was higher under load. In conclusion, the formation of a new bony structure was not affected by load after five weeks. However, load resulted in a larger area of active graft incorporation at this early stage. Possibly biological and immunological factors govern the early incorporation process independent of the local loading regime. [Copyright &y& Elsevier]

• Fills critical knowledge gap assessing multi-use forest management to meet ecological and economic objectives. • Small-scale, single-tree salvage logging has limited impact on yellow-cedar abundance and forest successional trajectories. • Salvage logging provided small to modest economic returns. • Application best suited for meeting ecological and economic objectives in forest-dependent communities. Cost-benefit analyses of salvage logging have generally focused on large-scale, landscape disturbances salvaged at high intensity, and there is limited research on the ecological and economic outcomes of low-intensity salvage implemented for the benefit of forest-dependent communities. Here, we assess the potential impacts of small-scale, single-tree salvage logging of a foundation tree species (yellow-cedar, Callitropsis nootkatensis) on ecological integrity against the viability of salvaged wood as a source of timber for cultural and economic purposes. We designed a salvage logging demonstration project in southeast Alaska, USA, and leveraged adjacent salvaged and unsalvaged, reference stands to: 1) investigate the degree to which salvage alters ecological integrity, defined by the abundance of yellow-cedar and post-disturbance stand trajectories, 2) track the volume and kinds of timber products generated by salvage logging activity, and 3) analyze the costs and revenues associated with the harvest and manufacturing of these products. Our results suggest that small-scale, single tree salvage logging has limited impact on yellow-cedar abundance and its potential to serve its foundation species role in forest successional trajectories while providing small to modest economic returns, though with large heterogeneity in net revenue among mill operators. Our findings indicate that salvage at this scale and intensity maintains ecological integrity but with limited economic viability. This management tool is thus best suited for land managers addressing multiple resource objectives in communities dependent on small, continuous streams of forest products. [ABSTRACT FROM AUTHOR]

The present study aimed to document dinocyst ecological preferences in Ambon Bay, Eastern Indonesia, and to investigate if the bay sediments serve as a seedbank for toxic bloom events. To this end, dinocyst and geochemical analyses of surface sediment samples were performed, along with physicochemical water column parameters. Twentythree dinocyst species were identified, and high dinocyst concentrations (up to ~12,000 cysts g−1 dry sediment) were found in the inner bay. Environmental factors such as surface water temperature and salinity generally played an important role in dinocyst distribution. The concentration of Polysphaeridium zoharyi cysts showed a strong positive correlation with phosphorus. A statistically significant correlation was also found with the concentration of other autotrophic dinocysts in the sediments, and an inverse correlation was observed with the sediment C/N ratio. Cysts may serve as seedbanks for Pyrodinium bahamense blooms in the area. • Dinocysts were comprised by 23 species, of which were dominated by Brigantedinium spp. and Polysphaeridium zoharyi • Ambon Bay, especially in the inner section receives massive organic matter and nutrient from the land • The bay harbors high concentration of the toxic P. zoharyi , which serves as a potential seedbank • Surface water temperature and salinity drive dinocyst distributions, and phosphorous is likely to induce P. zoharyi [ABSTRACT FROM AUTHOR]

• After forest disturbances, salvage logging (SL) is a common management strategy. • We reviewed whether SL modifies the risk or magnitude of subsequent disturbances. • SL increases or mitigates disturbances depending on local conditions, climate, and time. • Outcomes depend on how SL modifies or creates legacies connected to subsequent disturbance. • We propose a decision-making framework to manage subsequent disturbances. After natural forest disturbances such as wildfires, windstorms and insect outbreaks, salvage logging is commonly applied to reduce economic losses and mitigate subsequent disturbance risk. However, this practice is controversial due to its potential ecological impacts, and its capacity to mitigate or increase the risk of subsequent disturbances remains unclear. Salvage logging removes and alters the legacies remaining after natural disturbances, and it produces additional management legacies. Consequently, salvage logging has the potential to alter the functional connection between natural disturbances and also produce new functional connections to additional disturbances. We reviewed the efficacy of salvage logging in mitigating the risk of subsequent wildfire, insect outbreaks, hydrologic disturbances, mass movements, windthrow, browsing, and microclimatic stress. We asked: (1) Does salvage logging modify resistance to subsequent disturbances? (2) Through what mechanisms do such effects operate? Based on 96 publications, salvage logging can reduce total ecosystem fuels but increase small ground fuels and produce drier fuels in the short term, reduce bark beetle host trees and beetle-tree connectivity (though with little evidence for outbreak mitigation), magnify erosion and flood impacts of disturbance but with uncertain watershed-scale implications, increase susceptibility to windthrow at artificially created stand edges, remove the protective function of deadwood in preventing rockfall and avalanches, alter browsing pressure by modifying forage availability and hiding cover for herbivores and predators, and increase microclimatic stress due to greater radiation and temperature fluctuations. We propose a decision-making framework to evaluate the suitability of salvage logging to manage subsequent disturbances. It contemplates the likelihood and impacts of both salvage logging and the subsequent disturbances. In summary, salvage logging does not necessarily prevent subsequent disturbances, and sometimes it may increase disturbance likelihood and magnitude. Forecasting the suitability of salvage logging for management goals requires assessing the mechanisms through which salvage logging effects operate under local conditions, balanced with its impacts as a disturbance itself. Managing to foster the highest-priority functions and services –such as biodiversity conservation, pest mitigation or economic return– across different parts of disturbed forest landscapes based on decision-making procedures such as the one proposed may constitute the best response to uncertain subsequent disturbances. [ABSTRACT FROM AUTHOR]

The aim of the present work was to unravel which environmental drivers govern the dynamics of toxic dinoflagellate abundance as well as their associated paralytic shellfish toxins (PSTs), diarrhetic shellfish toxins (DSTs) and pectenotoxin-2 (PTX2) in Ambon Bay, Eastern Indonesia. Weather, biological and physicochemical parameters were investigated weekly over a 7-month period. Both PSTs and PTX2 were detected at low levels, yet they persisted throughout the research. Meanwhile, DSTs were absent. A strong correlation was found between total particulate PST and Gymnodinium catenatum cell abundance, implying that this species was the main producer of this toxin. PTX2 was positively correlated with Dinophysis miles cell abundance. Vertical mixing, tidal elevation and irradiance attenuation were the main environmental factors that regulated both toxins and cell abundances, while nutrients showed only weak correlations. The present study indicates that dinoflagellate toxins form a potential environmental, economic and health risk in this Eastern Indonesian bay. • Persistent occurrences of toxic dinoflagellate species and their associated toxin in Ambon Bay. • Paralytic shellfish toxin levels strongly correlated with Gymnodinium catenatum cell abundances. • The first record of Dinophysis miles correlating with Pectenotoxin-2 (PTX2) in natural samples. • Vertical mixing, tidal elevation and irradiance attenuation regulated both toxins and cell abundances. • Dinoflagellate toxins form a potential environmental, economic and health risk in this semi-enclosed bay. [ABSTRACT FROM AUTHOR]

Meniscal lesions often occur in the avascular area of the meniscus with little chance of spontaneous repair. An access channel in the meniscal tissue can function as an entrance for ingrowing repair tissue from the vascular periphery of the meniscus to the lesion in the avascular zone which again induced healing of the lesion. Implantation of a porous polymer in a full-thickness access channel induced healing. However, a better integration between meniscal tissue and the implant might be achieved with the combination of the newly developed porous polymers and a modified surgical technique. This might improve meniscal lesion healing and the repair of the access channel with neo-meniscal tissue.Longitudinal lesions were created in the avascular part of 24 canine lateral menisci and a partial-thickness access channel was formed to connect the lesion with the meniscal periphery. In 12 menisci, the access channel was left empty (control group), while in the remaining 12 menisci the polymer implant was sutured into the access channel.Repair of the longitudinal lesions was achieved with and without polymer implantation in the partial-thickness access channel. Polymer implants induced fibrous ingrowth with cartilaginous areas, which resembled neo-meniscal tissue. Implantation did not prevent articular cartilage degeneration. [Copyright &y& Elsevier]

Since meniscal geometry affects the cartilage contact pressures, it is essential to carefully define the geometry of the synthetic meniscal implant that we developed. Recently, six independent modes of sizeand shape-related geometry variation were identified through 3D statistical shape modeling (SSM) of the medial meniscus. However, this model did not provide information on the functional importance of these geometry characteristics. Therefore, in this study finite element simulations were performed to determine the influence of anatomically-based meniscal implant size and shape variations on knee cartilage contact pressures. Finite element simulations of the knee joint were performed for a total medial meniscectomy, an allograft, the average implant geometry, six implant sizes and ten shape variations. The geometries of the allograft and all implant variations were based on the meniscus SSM. Cartilage contact pressures and implant tensile strains were evaluated in full extension under 1200 N of axial compression. The average implant induced cartilage peak pressures intermediate between the allograft and meniscectomy and also reduced the cartilage area subjected to pressures >5 MPa compared to the meniscectomy. The smaller implant sizes resulted in lower cartilage peak pressures and compressive strains than the allograft, yet high implant tensile strains were observed. Shape modes 2, 3 and 6 affected the cartilage contact stresses but to a lesser extent than the size variations. Shape modes 4 and 5 did not result in changes of the cartilage stress levels. The present study indicates that cartilage contact mechanics are more sensitive to implant size than to implant shape. Down-sizing the implant resulted in more favorable contact mechanics, but caused excessive material strains. Further evaluations are necessary to balance cartilage contact pressures and material strains to ensure cartilage protection and longevity of the implant. [ABSTRACT FROM AUTHOR]

The limited intrinsic repair capacity of articular cartilage has stimulated continuing efforts to develop tissue engineered analogues. Matrices composed of type II collagen and chondroitin sulfate (CS), the major constituents of hyaline cartilage, may create an appropriate environment for the generation of cartilage-like tissue. In this study, we prepared, characterized, and evaluated type II collagen matrices with and without CS. Type II collagen matrices were prepared using purified, pepsin-treated, type II collagen. Techniques applied to prepare type I collagen matrices were found unsuitable for type II collagen. Crosslinking of collagen and covalent attachment of CS was performed using 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide. Porous matrices were prepared by freezing and lyophilization, and their physico-chemical characteristics (degree of crosslinking, denaturing temperature, collagenase-resistance, amount of CS incorporated) established. Matrices were evaluated for their capacity to sustain chondrocyte proliferation and differentiation in vitro. After 7 d of culture, chondrocytes were mainly located at the periphery of the matrices. In contrast to type I collagen, type II collagen supported the distribution of cells throughout the matrix. After 14 d of culture, matrices were surfaced with a cartilagenous-like layer, and occasionally clusters of chondrocytes were present inside the matrix. Chondrocytes proliferated and differentiated as indicated by biochemical analyses, ultrastructural observations, and reverse transcriptase PCR for collagen types I, II and X. No major differences were observed with respect to the presence or absence of CS in the matrices. [Copyright &y& Elsevier]

In revision surgery of the acetabulum bone defects can be filled with impacted human morsellized bone grafts. Because of a worldwide limited availability of human bone, alternatives are being considered. In this study we compared the initial stability of acetabular cups after reconstructing a cavitary defect with various compositions of impacted tricalciumphosphate-hydroxyapatite (TCP/HA) particles and mixes of TCP/HA particles and human grafts in a realistic acetabulum model. Primary cemented cups and reconstructions with impacted human cancellous grafts were used as reference. A dynamic load displaced the acetabular cups superomedially. The primary cemented cups showed the highest stability. The cups with impacted human grafts produced the most displacement. All reconstructions with the TCP/HA particles showed a high stability of the cups. However, especially when using large TCP/HA particles this was probably due to a large amount of cement penetration. Mixing TCP/HA particles with human grafts seemed to decrease cement penetration, although still a high stability was obtained. In this perspective, we concluded that TCP/HA particles might be useful as a bone graft extender in the reconstruction of acetabular bone defects. [Copyright &y& Elsevier]