Root Grafts Research Articles

Differences in xylem and phloem structure in living stumps of Norway spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.)

Summary Living stumps reported in many tree species were the first, circumstantial evidence of root grafting. Although stump overgrowth has been extensively studied in various tree species, anatomical observations have mainly focused on the xylem part. Here, we investigated the xylem and phloem structure in living stumps of two conifer species: Norway spruce (Picea abies (L.) Karst.) and silver fir (Abies alba Mill.). The mechanism of wound closure was similar in the two species, however, there were differences in the structure of wound tissues in wood and bark. Immediately after the injury, a callus consisting of parenchymal cells was formed, followed by wound-wood with wide increments. In addition, the wood structure and morphology of tracheids were changed. Tracheids lost their typical elongated and tapering structure; instead, numerous crooked and forked tracheids were present. Traumatic resin canals were present in both species but were more abundant in P. abies, which also had normal resin canals. While the structure of the xylem growth rings eventually normalized in both species, the width of the annual xylem increments was diminished. In both species, the typical structure of annual phloem increment was lost in the non-collapsed phloem and sclereids were very abundant in the collapsed phloem. In A. alba, the collapsed phloem was rich in swollen parenchyma cells containing blue-stained contents, while in P. abies, numerous large traumatic resin canals were conspicuous. The study showed that similar patterns of vascular tissue restoration exist in A. alba and P. abies in response to tree felling. However, there are certain species-specific peculiarities in the wood and phloem anatomical response, which might affect long-term stump functioning and survival.

Ethnic Rhinoplasty in the Brazilian Population: Current Concepts.

The large mixture of races in Brazil gives the nose its distinctive composition, which makes rhinoplasty difficult for these patients. Every patient should have their anatomy thoroughly examined on an individual basis, as there is no unique strategy that works for all situations. This is a narrative overview of the last 10 years' worth of literature that describes the ethnic traits of each nose, with a particular emphasis on the Brazilian nose, and talks about the major surgical approaches that can be applied in these situations. The low dorsum, broad nasal bones, thick skin, and bulbous tip are the primary features of the Brazilian nose. Many times, lateral osteotomies, root grafting, isotretinoin treatment for skin thickness, and neodomus formation are required. The Brazilian nose presents a surgical challenge that calls for the mastery of multiple procedures, not simply structured rhinoplasty. In certain cases, preservation rhinoplasty may even be used. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

How root-grafted trees form networks: Modeling network dynamics with pyNET

Natural root grafting is a widespread phenomenon in woody plants. While previous studies have focused on the effects of reduced growth and resource exchange at the individual level, we lack an understanding of the collective behavior of groups of grafted trees and the networks they form. Here, we present pyNET, a mechanistic agent-based model designed to explore the emergence of root graft networks. We performed simulation experiments with different scenarios involving water scarcity and different cost-benefit dynamics. Costs denote the resources required to form root grafts, while benefits denote the water redistributed among trees. Our model successfully replicates observed patterns linking structural variables to network characteristics. Specifically, we were able to reproduce observed characteristics such as grafting frequency and mean group size. In particular, we find that while the network structure is naturally strongly influenced by the size of the root system, the time and resources allocated to grafting are also critical factors. pyNET serves as a valuable tool for exploring the formation of root grafting networks under diverse environmental conditions and understanding their impact on resource competition. Our study supports theory development on the subject and hopefully stimulates further empirical studies.

Periostin Is a Candidate Regulator of the Host Microenvironment in Regeneration of Pulp and Dentin Complex and Periodontal Ligament in Transplantation with Stem Cell-Conditioned Medium.

The microenvironment is required for tissues to maintain their properties in vivo. This microenvironment encompasses the types and three-dimensional arrangement of cells forming the tissues, and their interactions with neighboring cells and extracellular matrices, as represented by the stem cell niche. Tissue regeneration depends not on the original tissue source of the transplanted cells, but on the microenvironment in which they are transplanted. We have previously reported pulp regeneration in a heterotopic root graft model by transplantation of conditioned medium alone, which suggests that host-derived cells expressing receptors for migration factors in conditioned medium migrate into the root canal and cause pulp regeneration. Regenerative medicine is needed to restore the original function of complex tissues. To achieve this, it is necessary to reproduce the changes in the microenvironment of the host tissue that accompany the regenerative response. Therefore, it is important to reproduce the microenvironment in vivo for further development of tissue regeneration therapy. Periostin is also found in the epithelial-mesenchymal junction, with expression sites that differ depending on the mineralized matrix stage, and is involved in regulation of calcification. We investigate whether periostin contributes to microenvironmental changes in regenerated pulp tissue. Dental pulp stem cells were induced into dentin, and gene expression of DSPP, nestin, DMP1, Runx2, and periostin was analyzed by qPCR and protein expression by IHC. Similarly, gene expression was analyzed using qPCR and protein expression using IHC in regenerated dental pulp obtained by ectopic transplantation. Since these regenerated tissues were observable on the same slice, it was possible to understand changes in the microenvironment within the tissues. Periostin promoted proliferation of pulp stem cells, migration in type I collagen, and calcification in regenerated pulp, which strongly suggests that periostin is a promising candidate as a factor that contributes to the microenvironment of regenerated pulp.

Inhibition of soluble epoxide hydrolase enhances the dentin-pulp complex regeneration mediated by crosstalk between vascular endothelial cells and dental pulp stem cells

BackgroundRevascularization and restoration of normal pulp-dentin complex are important for tissue-engineered pulp regeneration. Recently, a unique periodontal tip-like endothelial cells subtype (POTCs) specialized to dentinogenesis was identified. We have confirmed that TPPU, a soluble epoxide hydrolase (sEH) inhibitor targeting epoxyeicosatrienoic acids (EETs) metabolism, promotes bone growth and regeneration by angiogenesis and osteogenesis coupling. We hypothesized that TPPU could also promote revascularization and induce POTCs to contribute to pulp-dentin complex regeneration. Here, we in vitro and in vivo characterized the potential effect of TPPU on the coupling of angiogenesis and odontogenesis and investigated the relevant mechanism, providing new ideas for pulp-dentin regeneration by targeting sEH.MethodsIn vitro effects of TPPU on the proliferation, migration, and angiogenesis of dental pulp stem cells (DPSCs), human umbilical vein endothelial cells (HUVECs) and cocultured DPSCs and HUVECs were detected using cell counting kit 8 (CCK8) assay, wound healing, transwell, tube formation and RT-qPCR. In vivo, Matrigel plug assay was performed to outline the roles of TPPU in revascularization and survival of grafts. Then we characterized the VEGFR2 + POTCs around odontoblast layer in the molar of pups from C57BL/6 female mice gavaged with TPPU. Finally, the root segments with DPSCs mixed with Matrigel were implanted subcutaneously in BALB/c nude mice treated with TPPU and the root grafts were isolated for histological staining.ResultsIn vitro, TPPU significantly promoted the migration and tube formation capability of cocultured DPSCs and HUVECs. ALP and ARS staining and RT-qPCR showed that TPPU promoted the osteogenic and odontogenic differentiation of cultured cells, treatment with an anti-TGF-β blocking antibody abrogated this effect. Knockdown of HIF-1α in HUVECs significantly reversed the effect of TPPU on the expression of angiogenesis, osteogenesis and odontogenesis-related genes in cocultured cells. Matrigel plug assay showed that TPPU increased VEGF/VEGFR2-expressed cells in transplanted grafts. TPPU contributed to angiogenic-odontogenic coupling featured by increased VEGFR2 + POTCs and odontoblast maturation during early dentinogenesis in molar of newborn pups from C57BL/6 female mice gavaged with TPPU. TPPU induced more dental pulp-like tissue with more vessels and collagen fibers in transplanted root segment.ConclusionsTPPU promotes revascularization of dental pulp regeneration by enhancing migration and angiogenesis of HUVECs, and improves odontogenic differentiation of DPSCs by TGF-β. TPPU boosts the angiogenic–odontogenic coupling by enhancing VEGFR2 + POTCs meditated odontoblast maturation partly via upregulating HIF-1α, which contributes to increasing pulp-dentin complex for tissue-engineered pulp regeneration.

Heterogeneous saline water irrigation improves stomatal and nonstomatal restrictions to decrease yield reduction threshold in cherry tomato

Research on the response of tomato to homogeneous and heterogeneous salinity is essential for facility agriculture development in saline land. In this study, cherry tomatoes were irrigated with homogeneous or heterogeneous saline water in root zones by double root grafting. With irrigated fresh water (0/0) as a control, two homogeneous saline water irrigation treatments (S/S: 50/50, 100/100 mmol·L−1 NaCl) and two heterogeneous saline water irrigation treatments (0/S: 0/100, 0/200 mmol·L−1 NaCl) were used to analyze cherry tomato growth, photosynthesis, and osmoregulation under homogeneous and heterogeneous saline water irrigation. The results showed that the yields for the heterogeneous irrigation treatments with 0/100 and 0/200 mmol·L−1 NaCl were 1.2 and 3.1 times greater than those for the homogeneous treatments with 50/50 and 100/100 mmol·L−1 NaCl, respectively. The inhibitory effects of salinity on cherry tomato aboveground growth and stomatal restriction were alleviated by heterogeneous irrigation, which promoted photosynthesis and maintained a stable total root content compared with homogeneous salinity. In addition, the Na+ and Cl− contents in leaves under heterogeneous salinity were significantly reduced and high K+ and K+/Na+ levels as well as strong osmoregulation ability were maintained. In conclusion, the growth of and physiological damage to cherry tomato caused by salinity and the yield reduction threshold significantly improved under heterogeneous salinity. This could provide a theoretical basis for the adaptive cultivation of cherry tomato in saline land. We believe heterogeneous saline water irrigation, an irrigation technique for declining yield reduction thresholds in cherry tomato by improving stomatal and non-stomatal limitations, which could be consider to apply to tomato production in salt-affected land.

Effect of minimally invasive versus conventional aortic root replacement on transfusion and postoperative wound complications in patients: A meta-analysis.

We examined whether small incision aortic root replacement could reduce the amount of blood transfusion during operation and the risk of postoperative complications. An extensive e-review of the 4 main databases (PubMed, Cochrane, Web of Science and EMBASE) was carried out to determine all the published trials by July 2023. The search terms used were associated with partial versus full sternotomy and aortic root. This analysis only included the study articles that compared partial and full sternotomy. After excluding articles based on titles or abstracts, selected full-text articles had reference lists searched for any potential further articles. We analysed a total of 2167 subjects from 10 comparable trials. The minimally invasive aortic root graft in breastbone decreased the duration of hospitalization (MD, -2.58; 95% CI, -3.15, -2.01, p < 0.0001) and intraoperative red blood cell transfusion (MD, -1.27; 95% CI, -2.34, -0.19, p = 0.02). However, there were no significant differences in wound infection (OR, 0.88; 95% CI, 0.16, 4.93, p = 0.88), re-exploration for bleeding (OR, 0.96; 95% CI, 0.60, 1.53, p = 0.86), intraoperative blood loss (MD, -259.19; 95% CI, -615.11, 96.73, p = 0.15) and operative time (MD, -7.39; 95% CI, -19.10, 4.32, p = 0.22); the results showed that the microsternotomy did not differ significantly from that of the routine approach. Small sternotomy may be an effective and safe substitute for the treatment of the aorta root. Nevertheless, the wide variety of data indicates that larger, well-designed studies are required to back up the current limited literature evidence showing a benefit in terms of complications like postoperative wound infections or the volume of intraoperative red blood cell transfusion.

Outcomes of aortic root replacement with tricuspid aortic valve reimplantation in patients with residual aortic regurgitation

ObjectiveTo characterize residual aortic regurgitation (AR), identify its risk factors, and evaluate outcomes following aortic root replacement with aortic valve reimplantation. MethodsFrom 2002 to 2020, 756 patients with a tricuspid aortic valve underwent elective reimplantation for aortic root aneurysm. AR on transthoracic echocardiograms before hospital discharge was graded as mild or greater. Machine learning was used to identify risk factors for residual AR and subsequent aortic valve reoperation. ResultsSixty-five patients (8.6%) had mild (58 [7.7%]) or moderate (7 [0.93%]) residual postoperative AR. They had more severe preoperative AR (38% vs 12%; P < .0001), thickened cusps (7.7% vs 2.2%; P = .008), aortic valve repair (38% vs 23%; P = .004), and multiple returns to cardiopulmonary bypass for additional repair (11% vs 3.3%; P = .003) than those without AR. Predictors of residual AR were severe preoperative AR, smaller aortic root graft, and concomitant cusp repair. At 10 years, patients with versus without residual AR had more moderate or severe AR (48% vs 7.0%; P < .0001) and freedom from reoperation was worse (89% vs 98%; P < .0001). Residual AR was a risk factor for early reoperation. Concomitant coronary bypass, lower body mass index, and lower ejection fraction were risk factors for late reoperation. Ten-year survival was similar among patients with and without residual AR (97% vs 93%; P = .43). ConclusionsResidual AR after elective reimplantation of a tricuspid aortic valve for aortic root aneurysm is uncommon. Patients with severe preoperative AR and those who undergo valve repair have higher risk for residual AR, which can progress and increase risk of aortic valve reoperation.

Pest categorisation of the avocado sunblotch viroid.

The EFSA Panel on Plant Health conducted a pest categorisation of the avocado sunblotch viroid (ASBVd) for the EU. The identity of ASBVd, a member of the genus Avsunviroid (family Avsunviroidae) is clearly defined and detection and identification methods are available. The pathogen is not included in the EU Commission Implementing Regulation 2019/2072. ASBVd has been reported in Australia, Ghana, Guatemala, Israel, Mexico, Peru, South Africa, USA (California, Florida) and Venezuela. In the EU, it has been reported in Greece (Crete Island) and Spain. The pathogen could establish in the EU wherever avocado (Persea americana) is grown. The only known natural host of ASBVd is avocado to which it causes the severe 'avocado sunblotch' disease, characterised by white, yellow, red or necrotic depressed areas or scars on the fruit surface, bleached veins and petioles of the leaf, and rectangular cracking patterns in the bark of the old branches. Fruit yield and quality are severely diminished. ASBVd infects under experimental conditions a few more species in the family Lauraceae. The viroid is naturally transmitted at an extremely high rate by seeds (up to 100% in asymptomatically infected trees), but with a low efficiency by pollen (only to the produced seeds), and possibly through root grafts. Plants for planting, including seeds, and fresh avocado fruits were identified as the most relevant pathways for further entry of ASBVd into the EU. Avocado crops are cultivated in southern EU countries. Should the pest further enter and establish in the EU, impact on the production of avocado is expected. Phytosanitary measures are available to prevent entry and spread of the viroid in the EU. ASBVd fulfils the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

Longitudinal follow-up by MR angiography reveals progressive dilatation of the distal aorta after aortic root replacement in Marfan syndrome.

To define and compare growth rates of the distal aorta in Marfan patients with and without aortic root replacement using serial MR angiography (MRA). We retrospectively included 136 Marfan patients with a total of 645 MRAs who underwent a median of five MRAs (range: 2-13) at 1.5T and 3T in annual intervals. Of these, 41 patients (34.8 ± 12years) had undergone aortic root replacement. The remaining 95 patients (29.0 ± 17years) still had a native aorta and served as the control group. Thoracic aortic diameters were independently measured at eleven predefined levels. Estimated growth rates were calculated using a mixed effects model adjusted for sex, age, BMI, and medication. Marfan patients with aortic root replacement revealed the highest mean estimated growth rate in the proximal descending aorta (0.77mm/year, CI: 0.31-1.21). Mean growth rates at all levels of the distal thoracic aorta were significantly higher in patients with aortic root replacement (0.28-0.77mm/year) when compared to patients without aortic root replacement (0.03-0.07mm/year) (all p < 0.001). Antihypertensive medication, gender, and BMI had no significant impact on the distal aortic growth rates. Distal thoracic aortic diameters increase at a significantly higher rate in Marfan patients with aortic root replacement compared to Marfan patients without aortic root replacement. Further studies are warranted to investigate if the increased growth rate of the distal thoracic aorta after aortic root replacement is caused by altered hemodynamics due to the rigid aortic root graft or due to the general genetic disposition of post-operative Marfan patients. High growth rates of the distal aorta after aortic root replacement underline the need for careful life-long aortic imaging of Marfan patients after aortic root replacement. • Aortic growth rates in Marfan patients with aortic root replacement are highest in the mid-aortic arch, the proximal- and mid-descending aorta. • Growth rates of the distal thoracic aorta are significantly higher in Marfan patients with aortic root replacement compared to Marfan patients without aortic root replacement. • Antihypertensive medication, gender, and BMI have no significant impact on distal aortic growth rates in Marfan patients.

Evaluating effectiveness of girdle-herbicide containment of below-ground spread of oak wilt (Bretziella fagacearum)

Oaks (Quercus spp) are one of the most important sources of timber, mast for wildlife, and ecosystem services across the eastern US. Increasingly, this genus is at risk from diseases including oak wilt, which is one of the most serious threats to oaks, caused by the fungus, Bretziella fagacearum. The upper Midwest has over 5 million ha of oak forests, much of which is on rocky glaciated soils where traditional methods of containing below-ground spread of oak wilt (e.g., vibratory plow lines) are not feasible. We evaluated an alternative containment method of girdling and herbicide (GH) of oak wilt infected trees as well as neighboring oak trees likely connected via root grafts. Our results demonstrated that GH was effective at controlling below-ground spread of oak wilt (overall success rate: 55 %). Best control was achieved when infection centers were small (≤4 newly infected trees), where GH was 81 % effective at containing oak wilt. Containment was only 29 % in larger infection centers (≥5 newly infected trees). The best predictor of success was the number of newly infected trees (p = 0.02) even when considering other factors that could dictate the size of infection centers (e.g., diameter of trees, or number of neighboring trees treated). Our results illustrate the importance of early and rapid management of oak wilt infections and offer a starting place for continued improvement of the GH methodology.

Does natural root grafting make trees better competitors?

Natural root grafts (anastomoses) are morphological unions formed between roots of different trees. Common root systems allow translocation of water, nutrients and photosynthesis products between grafted trees, affecting their growth and their physiology. As carbohydrates are redistributed among grafted trees, the formation of a common root system could reduce the negative effect of intraspecific competition for light or soil resources within stands. The aim of this study was to investigate the role of root grafting on intraspecific competition and growth of balsam fir Abies balsamea. We studied inter‐tree relationships in three natural balsam fir stands of the boreal forest of Quebec (Canada) that contained an average 36% of grafted trees. At each stand, ring width and basal area of trees were measured using dendrochronology techniques. We used mixed linear models to test the effect of root grafting and intraspecific competition on annual basal area increment of trees. Trees before grafting had higher growth rates than trees once grafted. Thus, root grafting did not improve tree growth. Growth of grafted trees was more negatively affected by intraspecific competition than growth of non‐grafted trees. Thus, grafted trees cannot be considered as better competitors than non‐grafted trees. Under high intraspecific competition, growth of larger grafted trees was less affected than that of smaller trees suggesting that they were able to divert resources at their advantage within a union. Our study demonstrated that grafted trees acted on each other's growth and provides support for the idea that grafted trees respond to competition for resources more as a community rather than as individual trees.

Simultaneous presence of Mycoplasma salivarium and Tannerella forsythia in the implant sulcus after lateral augmentation with autogenous root grafts is associated with increased sulcus probing depth.

To characterize a potential pathogenic role of Mycoplasma salivarium and bacterial co-detection patterns on different implant augmentation types. 36 patients were non-randomly assigned to autogenous lateral alveolar ridge augmentation with either cortical autogenous bone blocks, or healthy autogenous tooth roots or non-preservable teeth. Mucosal inflammation was assessed by probing pocket depth (PD) at all sampling sites and by bleeding on probing (BOP) in a subset of sampling sites, and standardized biofilm samples were obtained from the submucosal peri-implant sulcus and sulcus of a contralateral tooth at two times (t1 after implant placement; t2 after six months). Seven bacterial species were quantified using Taqman PCR. Mucosal inflammation did not differ between augmentation groups, but peri-implant sulci showed increased abundance of M. salivarium after augmentation with autogenous tooth roots lasting for at least six months (t1 p = 0.05, t2 p = 0.011). In M. salivarium-positive samples, Tannerella forsythia was correlated with PD (R = 0.25, p = 0.035) This correlation was not observed in M. salivarium-negative samples. Compared to all other samples, PD was deeper in co-detection (i.e., simultaneous M. salivarium and T. forsythia) positive samples (p = 0.022). No association of single or co-detection of bacteria with BOP was observed. Presence of M. salivarium in peri-implant sulci varies with augmentation method and is associated with increased PD but not BOP. A potential causal role of M. salivarium in inflammation through a mechanism involving co-presence of T. forsythia requires further study.

Root grafts matter for inter-tree water exchange - a quantification of water translocation between root grafted mangrove trees using field data and model based indication.

Trees interconnected through functional root grafts can exchange resources, but the effect of exchange on trees remains under debate. A mechanistic understanding of resources exchange via functional root grafts will help understand their ecological implications for tree water exchange for individual trees, groups of trees, and forest stands. To identify the main patterns qualitatively describing the movement of sap between grafted trees, we reviewed available literature on root grafting in woody plants that focus on tree allometry and resource translocation via root grafts. We then extended the BETTINA model, which simulates mangrove (Avicennia germinans) tree growth on the individual tree scale, in order to synthesize the available empirical information. Using allometric data from a field study in mangrove stands, we simulated potential water exchange and analyzed movement patterns between grafted trees. In the simulations, relative water exchange ranged between -9.17 and 20.3 %, and was driven by gradients of water potential, i.e. differences in tree size and water availability. Moreover, the exchange of water through root grafts alters the water balance of trees and their feedback with the soil: grafted trees that receive water from their neighbors reduce their water uptake. Our individual-tree modelling study is a first theoretical attempt to quantify root graft-mediated water exchange between trees. Our findings indicate that functional root grafts represent a vector of hydraulic redistribution, helping to maintain the water balance of grafted trees. This non-invasive approach can serve as a fundament for designing empirical studies to better understand the role of grafted root interaction networks on a broader scale.

Off-label Rescue Agents for Vasoplegic Syndrome after Cardiopulmonary Bypass

Abstract Introduction: Cardiovascular disease is the number one cause of death in the United States today1. Cardiopulmonary bypass (CPB) is a common technique used in the surgical management of cardiovascular disease. A relatively common complication of CPB is vasoplegia, which has an approximate incidence of anywhere from 5-25%1-8. Methylene blue is used to treat vasoplegic syndrome (VS) when higher dose vasopressors are ineffective. Vasoplegic syndrome (VS) is defined as a syndrome of low systemic vascular resistance (SVR) in the presence of normal or high cardiac output1-4. Generally, VS is characterized as a high cardiac output state (CI &lt; 2.2 L/min/m2) with difficulty maintaining a mean arterial pressure (MAP) greater than 60 mmHg despite increasing vasopressor requirements1-3,7. The focus of this case report is to examine methylene blue’s effectiveness in treating vasoplegia after weaning from CPB. This case report will also compare and contrast methylene blue and another rescue agent, hydroxocobalamin, and how they combat vasoplegia. Case presentation: The case involved a 65-year-old male presenting for an aortic root and aortic valve replacement and removal of an abscess in his heart. The patient was under general anesthesia, put on cardiopulmonary bypass and then underwent a deep hypothermic circulatory arrest for the placement of the aortic root graft and aortic valve. Weaning from bypass was difficult as a result of vasoplegia, for which methylene blue was given when vasopressor requirements were increasing. Discussion: Methylene blue is a guanylyl cyclase inhibitor that has been found to increase SVR and decrease vasopressor requirements in vasoplegic syndrome by inhibiting nitric oxide synthase (NOS), thus limiting the production of nitric oxide (NO) as well as inhibiting the enzyme guanylyl cyclase and preventing vasodilation5. The timing of administration of methylene blue is debatable, being that it is commonly given postoperatively, but the literature favors earlier administration in high-risk patients that will be placed on CPB2-5. Typical dosing for methylene blue is 2 mg/kg intravenously (IV) but increasing the dose to 3 mg/kg can be used to account for the larger volume of distribution (Vd) that is present in patients on CPB2. The only true contraindications for methylene blue are a hypersensitivity to the drug and a deficiency in the glucose-6-phosphate dehydrogenase, which is the enzyme that is responsible for turning methylene blue into its metabolites1-8. Treating VS with methylene blue after CPB has shown significantly quicker recovery and normal hemodynamics, shorter duration of vasopressor infusions, less incidence of renal complications, shorter length of stay (LOS) and less 30-day mortality6.

Two clinical tests assessing long thoracic nerve function to determine C5 and C6 root graft eligibility in patients with brachial plexus injury.

Identifying roots available for grafting is of paramount importance prior to reconstructing complex injuries involving the brachial plexus. This is traditionally achieved by combining input from both clinical examinations and imaging studies. In this paper, the authors describe and evaluate two new clinical tests to study long thoracic nerve function and, consequently, to predict the status of the C5 and C6 roots after global brachial plexus injuries. From March 2020 to December 2020, in 41 patients undergoing brachial plexus repair, preoperative clinical assessments were performed using modified C5 and C6 protraction tests, C5 and C6 Tinel's signs, and MRI findings to predict whether graft-eligible C5 and C6 roots would be identified intraoperatively. Findings from these three assessments were then combined in a logistic regression model to predict graft eligibility, with overall predictive accuracies calculated as areas under receiver operating characteristic curves. In the 41 patients, the pretest probability of C5 root availability for grafting was 85% but increased to 92% with a positive C5 protraction test and to 100% when that finding was combined with a positive C5 Tinel's sign and favorable MRI findings. The pretest probability of C6 root availability was 40%, which increased to 84% after a positive C6 protraction test and to 93% when the protraction test result concurred with Tinel's test and MRI findings. Combining observations of the protraction tests with Tinel's sign and MRI findings accurately predicts C5 and C6 root graft eligibility.

Safe Technique of Coronary Button Preparation in Redo Bentall Operation.

We introduce a technique of coronary button reconstruction in performing a redo Bentall procedure. A coronary button is prepared leaving a 3 to 4 mm rim of old Dacron graft surrounding the previous button. The Dacron rim may be sewn to the new aortic root graft directly or via an interposed 8- or 10-mm graft, using a modified Cabrol technique. If the button is comprised of good tissue and can be well-mobilized, it is removed from the Dacron rim and anastomosed directly to the new Dacron graft.

Sinks for plant surplus carbon explain several ecological phenomena

Plants engage in many processes and relationships that appear to be wasteful of the high-energy compounds that they produce through carbon fixation and photosynthesis. For example, living trees keep leafless tree stumps alive (i.e. respiring) and support shaded understory trees by sharing carbohydrates through root grafts or mycorrhizal fungal networks. Plants exude a diverse array of organic compounds from their roots and leaves, which support abundant rhizosphere and phyllosphere microbiomes. Some plants release substantial amounts of sugar via extra-floral nectaries, which enrich throughfall and alter lichen communities beneath the canopy. Large amounts of photosynthetically fixed carbon are transferred to root associates such as mycorrhizal fungi and N-fixing micro-organisms. Plants also respire fixed C through an alternative pathway that does not generate ATP. Rates of each of these processes appear to be highest when plants are growing under mild-to-moderate deficiencies of nutrients or water. During this stage of deficiency, aboveground plant growth is curtailed more than photosynthesis, causing leaves to produce surplus carbohydrates. Each of the above phenomena provide a sink for these surplus carbohydrates, thereby preventing feedback inhibition of photosynthesis, and perpetuating the influx of C. Because these processes incur little cost to the source plant, they need not provide a benefit beyond the removal of surplus carbohydrates.

Outcome and success rate of dental autotransplantation: A long‐term evaluation of 144 teeth

Aim To evaluate a sample consisting of 144 autotransplanted teeth performed in 128 patients, which were subjected to periodic follow-up from 6 months to 23 years. Materials and methods The sample consists of 33 molars, 91 premolars, 4 canines and 16 incisors. Clinical and radiographic examinations were performed every 6 months since the day of transplantation. In the last follow-up visit, successful autotransplantation should present the following: absence of active inflammatory root resorption and ankylosis; crown/root ratio <1 (root size higher than crown size); radiographic evidence of additional root growth (in case of partly formed root grafts); absence of tooth mobility, periodontal disease and persistent periapical lesions after endodontic treatment. The success rate was acquired by percentage of transplanted teeth that met the criteria in relation to the total number of transplanted teeth in the sample. Statistical tests were performed as indicators of success. Results The evaluation showed a 93% success rate for the completion of autotransplanted teeth. Eight teeth showed inflammatory root resorption and five teeth, ankylosis. The success rate of molars was 91% and canines was 100%. All variables presented statistical p value of <0.05, except for tooth colouration, root development, donor site and recipient site. Conclusion These findings support that tooth autotransplantation is a reliable treatment and preferred solution for early tooth loss in children and young patients. Furthermore, it demands the professionals the correct evaluation as well as to create the necessary conditions regarding the site receptor, tooth to be transplanted, quality of the surgical procedure, aesthetic complement and periodic control of each case.

Aortic pseudoaneurysm with fistulization to the right atrium: A case report

The surgical technique to repair aortic root aneurysm has undergone significant advancement since the Bentall procedure was first performed in 1968.1 The original Bentall used a composite aortic root graft with a mechanical aortic valve, wrapping native aortic tissue around the proximal graft. While the modified Bentall with coronary buttons has demonstrated fewer complications, the risk of pseudoaneurysm (PsA), although rarer, persists. PsA may complicate up to 6% to 10% of all aortic root repairs, at times several years following surgery.