Soil CO2 and N2O emissions and microbial abundances altered by temperature rise and nitrogen addition in active-layer soils of permafrost peatland

Changes in soil CO₂ and N₂O emissions due to climate change and nitrogen input will result in increased levels of atmospheric CO₂ and N₂O, thereby feeding back into Earth's climate. Understanding the responses of soil carbon and nitrogen emissions mediated by microbe from permafrost peatland to temperature rising is important for modeling the regional carbon and nitrogen balance. This study conducted a laboratory incubation experiment at 15 and 20°C to observe the impact of increasing temperature on soil CO₂ and N₂O emissions and soil microbial abundances in permafrost peatland. An NH₄NO₃ solution was added to soil at a concentration of 50 mg N kg^-1 to investigate the effect of nitrogen addition. The results indicated that elevated temperature, available nitrogen, and their combined effects significantly increased CO₂ and N₂O emissions in permafrost peatland. However, the temperature sensitivities of soil CO₂ and N₂O emissions were not affected by nitrogen addition. Warming significantly increased the abundances of methanogens, methanotrophs, and nirK-type denitrifiers, and the contents of soil dissolved organic carbon (DOC) and ammonia nitrogen, whereas nirS-type denitrifiers, β-1,4-glucosidase (βG), cellobiohydrolase (CBH), and acid phosphatase (AP) activities significantly decreased. Nitrogen addition significantly increased soil nirS-type denitrifiers abundances, β-1,4-N- acetylglucosaminidase (NAG) activities, and ammonia nitrogen and nitrate nitrogen contents, but significantly reduced bacterial, methanogen abundances, CBH, and AP activities. A rising temperature and nitrogen addition had synergistic effects on soil fungal and methanotroph abundances, NAG activities, and DOC and DON contents. Soil CO₂ emissions showed a significantly positive correlation with soil fungal abundances, NAG activities, and ammonia nitrogen and nitrate nitrogen contents. Soil N₂O emissions showed positive correlations with soil fungal, methanotroph, and nirK-type denitrifiers abundances, and DOC, ammonia nitrogen, and nitrate contents. These results demonstrate the importance of soil microbes, labile carbon, and nitrogen for regulating soil carbon and nitrogen emissions. The results of this study can assist simulating the effects of global climate change on carbon and nitrogen cycling in permafrost peatlands.

Sinusoidal and lymphatic vessel growth is controlled by reciprocal VEGF-C-CDH5 inhibition

Sinusoids are specialized, low pressure blood vessels in the liver, bone marrow, and spleen required for definitive hematopoiesis. Unlike other blood endothelial cells (ECs), sinusoidal ECs express high levels of VEGFR3. VEGFR3 and its ligand VEGF-C are known to support lymphatic growth, but their function in sinusoidal vessels is unknown. In this study, we define a reciprocal VEGF-C/VEGFR3-CDH5 (VE-cadherin) signaling axis that controls growth of both sinusoidal and lymphatic vessels. Loss of VEGF-C or VEGFR3 resulted in cutaneous edema, reduced fetal liver size, and bloodless bone marrow due to impaired lymphatic and sinusoidal vessel growth. Mice with membrane-retained VE-cadherin conferred identical lymphatic and sinusoidal defects, suggesting that VE-cadherin opposes VEGF-C/VEGFR3 signaling. In developing mice, loss of VE-cadherin rescued defects in sinusoidal and lymphatic growth caused by loss of VEGFR3 but not loss of VEGF-C, findings explained by potentiated VEGF-C/VEGFR2 signaling in VEGFR3-deficient lymphatic ECs. Mechanistically, VEGF-C/VEGFR3 signaling induces VE-cadherin endocytosis and loss of function via SRC-mediated phosphorylation, while VE-cadherin prevents VEGFR3 endocytosis required for optimal receptor signaling. These findings establish an essential role for VEGF-C/VEGFR3 signaling during sinusoidal vascular growth, identify VE-cadherin as a powerful negative regulator of VEGF-C signaling that acts through both VEGFR3 and VEGFR2 receptors, and suggest that negative regulation of VE-cadherin is required for effective VEGF-C/VEGFR3 signaling during growth of sinusoidal and lymphatic vessels. Manipulation of this reciprocal negative regulatory mechanism, e.g. by reducing VE-cadherin function, may be used to stimulate therapeutic sinusoidal or lymphatic vessel growth.

[Precise application of sleeve gastrectomy]

With the improvement of the national economy and living standards, the prevalence of obesity and related metabolic diseases is increasing yearly. The treatment effect of traditional diet control, physical exercise, and drug therapy are not ideal. Metabolic and bariatric surgery is not only aimed at weight loss, but also improves or resolves a variety of metabolic comorbidities, such as type 2 diabetes, hypertension, sleep apnea syndrome, and hyperlipidemia, enhancing the quality of life of patients. Surgical methods are also updated and iterated with the continuous development of metabolic surgery for weight loss. At present, more than 50% of the mainstream procedures are laparoscopic sleeve gastrectomy (LSG). The application of LSG should focus on precise surgical operations and indications to avoid or reduce adverse reactions and complications, so as to maximize the effect of bariatric surgery. At the same time, standardized postoperative management, multidisciplinary team (MDT) and in-hospital database construction, dietary nutrition and exercise guidance after discharge, and regular follow-up review are still important guarantees for the weight loss effect.

Long-term nitrogen addition alters peatland plant community structure and nutrient resorption efficiency

As an elemental carbon (C) and nitrogen (N) pool in the world, peatlands are very sensitive to environmental changes. Under global warming, the increase in available N affects the dynamic changes of plant community structure and nutrients in a permafrost peatland. This study was based on a long-term in situ N addition experiment that had been conducted for 9 years. It utilized the peatland in the permafrost area of Great Hing'an Mountain as the research object to analyze the effects of N addition on the growth characteristics, community structure, and nutrient dynamics of peatland plants. The N inputs were N1: 6 g N m^-2·year^-1, N2: 12 g N m^-2·year^-1 and N3: 24 g N m^-2·year^-1, respectively. Our results showed that the adding N can affect the plant community structure of peatland by affecting the plant growth characteristics. The diversity and richness of plant species in the peatland decreased as the concentration of added N increased. The long-term N addition can reduce the N limitation of plants to some extent. Still, it could further aggravate their phosphorus (P) limitation, resulting in the joint limitation of N and P or the complete limitation by P. The N resorption efficiency decreased with the increase of N addition level. The P resorption efficiency of different plants had varied responses to the changes in the N nutrient environment. Our study clarified the impact of long-term N addition on the plant community structure and nutrient dynamics of peatland in a permafrost area and provided an important theoretical basis to accurately evaluate the carbon and nitrogen balance of peatland in a permafrost area owing to future climate change.

Remote telemedicine strategy based on multi-risks intervention by intelligent wearable health devices in elderly comorbidities patients with coronary heart disease

Background

Telemedicine based on wearable intelligent health devices becomes increasingly promissing for the elderly due to the accelerated aging population. Especially during COVID-19 pandemic, more elderly coronary heart disease patients with chronic comorbidities are in less secondary prevention management at home.

Objective

To explore the prevention effect on main cardiovascular risk factors and repeated hospitalization in elderly comorbidities patients by telemedicine intervention based on multi-parameter wearable monitoring devices.

Methods

Total of 337 patients with comorbidities of coronary heart disease, hypertension and diabetes, with age more than 65 years old were recruited in the study from October 2019 to January 2021. They were randomly divided into control group and telemedcine intervention group. The latter used remote multi-parameter wearable devices to measure blood pressure, glycemic and electrocardiograph at home every day. A real-time monitoring platform would alarm any abnormal data to the doctors. Both doctors and patients can read the measurement results on a real-time mobile phone APP and interact with each other remotely twice a week routinely. A medical team remotely indicated the medications, while offering guidance on lifestyle. In contrast, the control group adopted traditional outpatient medical strategy to manage diseases.

Results

A total of 306 patients were enrolled in the follow-up experiment finally: 153 in the intervention group and 153 in the control group. Patient characteristics at baseline were balanced between two groups. After 12 months, compared with the control group, the intervention group saw the following metrics significantly reduced: systolic blood pressure (SBP) (131.66±9.43 vs 137.20±12.02 mmHg, P=0.000), total cholesterol (TC) (3.65±0.79 vs 4.08±0.82 mmol/L, P=0.001), low density lipoprotein cholesterol (LDL-C) (2.06±0.53 vs 2.38±0.61 mmol/L, P=0.002), and fasting blood glucose (FBG) (6.26±0.75 vs 6.81±0.97 mmol/L, P=0.000), while the following metrics went up significantly: blood pressure control rate (77.3% vs 59.1%, P=0.039), blood lipid control rate(39.4% vs 21.2%, P=0.037), glycemic control rate (71.2% vs 51.5%, P=0.031), and medication adherence score (7.10±0.77 vs 6.80±0.73, P=0.020). Linear regression model analysis indicates that when interaction frequency ≥1.53, 2.47 and 1.15 times/week, the SBP, LDL-C and FBG levels would be controlled, respectively. Cox survival analysis finds that the hospitalization rate of intervention group is significantly lower than that of the control group (24.18% vs 35.29%, P=0.031).

Conclusion

The telemedicine interactive intervention based on multi-parameter wearable devices provides effectively improvement of cardiovascular risk controlling, medication adherence, while reducing the hospitalization rate of patients. A frequency of doctor-patient interactions more than 2 times/week is beneficial for disease management the elderly at home.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Key scientific research project of Health Commission

Closely related type II-C Cas9 orthologs recognize diverse PAMs

The RNA-guided CRISPR/Cas9 system is a powerful tool for genome editing, but its targeting scope is limited by the protospacer-adjacent motif (PAM). To expand the target scope, it is crucial to develop a CRISPR toolbox capable of recognizing multiple PAMs. Here, using a GFP-activation assay, we tested the activities of 29 type II-C orthologs closely related to Nme1Cas9, 25 of which are active in human cells. These orthologs recognize diverse PAMs with variable length and nucleotide preference, including purine-rich, pyrimidine-rich, and mixed purine and pyrimidine PAMs. We characterized in depth the activity and specificity of Nsp2Cas9. We also generated a chimeric Cas9 nuclease that recognizes a simple N₄C PAM, representing the most relaxed PAM preference for compact Cas9s to date. These Cas9 nucleases significantly enhance our ability to perform allele-specific genome editing.

NIR-II imaging with ICG for identifying perforators, assessing flap status and predicting division timing of pedicled flaps in a porcine model

The use of skin flaps to fill large defects is a key surgical technique in reconstructive surgery, effective real-time in vivo imaging for flap design and use is urgent. Currently, fluorescent imaging in the second NIR window (NIR-II; 1000-1700 nm) is characterized by non-radiation, less expensive and higher resolution in comparisons with the first NIR window (NIR-I; 700-900 nm) and other traditional imaging modalities. In this article, we identified the location and numbers of perforators and choke zone via NIR-II imaging. Then, eight abdominal perforator flaps were established and the perfusion zones were evaluatedat special time points. Finally, after eight pedicled flaps establishment, NIR-II imaging was used to guide the optimal timing for division of flap pedicle. The results showed that NIR-II fluorescence imaging with indocyanine green (ICG) can reliably visualize vascular supply, which makes it to be an accurate and in vivo imaging approach to flap clinical design and use.

Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6  ×  6  ×  6 m 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.

Warming-Induced Labile Carbon Change Soil Organic Carbon Mineralization and Microbial Abundance in a Northern Peatland

Climate warming affects the carbon cycle of northern peatlands through temperature rises and a changing carbon availability. To clarify the effects of elevated temperature and labile carbon addition on SOC mineralization, as well as their microbial driving mechanisms, topsoil (0–10 cm) and subsoil (10–20 cm) were collected from a peatland in the Great Hing’an Mountains and incubated with or without ¹³C-glucose at 10 °C and 15 °C for 42 days. The results showed that 5 °C warming significantly stimulated SOC mineralization along with NH₄⁺-N and NO₃⁻-N content increases, as well as a decrease in invertase and urease activities. Glucose addition triggered a positive priming effect (PE) in the early stage of the incubation but changed to a negative PE in the late stage of the incubation. Glucose likely regulates carbon dynamics by altering fungi: bacteria, soil invertase, and β-glucodase activities, and MBC, DOC, NH₄⁺-N contents. Glucose addition increased fungal abundance in 0–10 cm at 10 °C and 15 °C, and 10–20 cm at 10 °C, respectively, but significantly decreased fungal abundance in 10–20 cm at 15 °C. Glucose addition decreased bacterial abundance in 0–10 cm at 10 °C but increased bacterial abundance in 10–20 cm soil at 10 °C, and in 0–10 and 10–20 cm soils at 15 °C, respectively. Glucose addition significantly decreased the fungi: bacteria ratio in 0–20 cm soils at 15 °C. In addition, Q₁₀ was significantly positively correlated with the changes in soil DOC, NH₄⁺-N contents, invertase, and β-glucosidase activities, while negatively correlated with fungi: bacteria and urease activities after 5 °C of warming, and glucose addition significantly increased the Q₁₀. Labile carbon may decrease carbon losses in northern peatlands that inhibit warming-induced carbon emission increase, thus partially buffering soil carbon content against change.

POS0074 IMMUNOLOGICAL DIFFERENCES BETWEEN PsA PATIENTS WHO ARE TUMOR NECROSIS FACTOR INHIBITOR-NAIVE AND WHO HAVE INADEQUATE RESPONSE TO TUMOR NECROSIS FACTOR INHIBITORS

Background

A better understanding of the immunological differences between psoriatic arthritis (PsA) patients (pts) who are tumor necrosis factor inhibitor (TNFi)-naïve & who have inadequate response to TNFi (TNFi-IR) may guide treatment choices. In DISCOVER-1, benefit of the IL-23p19 subunit inhibitor guselkumab (GUS) every-four-weeks (Q4W) & Q8W vs placebo (PBO) in improving PsA signs & symptoms was seen in adults with active PsA.1 The Ph3b COSMOS study of GUS Q8W vs PBO in TNFi-IR PsA pts corroborated these findings.2

Objectives

Assess baseline (BL) molecular differences between TNFi-naïve & -IR PsA pts & investigate GUS pharmacodynamic (PD) effect on cytokine expression over time in these cohorts.

Methods

Serum samples collected from consenting biomarker substudy pts in DISCOVER-11 (TNFi-naïve [n=101] & -IR [n=17]), DISCOVER-23 (TNFi-naïve [n=150]), & COSMOS2 (TNFi-IR [n=76]) were analyzed for selected serum cytokine levels. TNFi-IR pts in this post-hoc analysis had active PsA & discontinued 1-2 TNFi due to inadequate efficacy; these pts required a TNFi-specific washout period prior to starting GUS. PD effect of GUS Q8W on cytokine levels was assessed. Differential BL cytokine expression, associations between BL cytokine levels & clinical response (Psoriasis [PsO] Area & Severity Index 75% improvement from BL [PASI75] & American College of Rheumatology 20% improvement [ACR20]), & GUS effect on cytokine levels were analyzed with a General linear model & Spearman linear regression.

Results

BL pt demographics, disease characteristics, & conventional synthetic disease-modifying antirheumatic drug (csDMARD) use were comparable between TNFi-naïve (DISCOVER-1 & -2, N=251) & -IR (DISCOVER-1 & COSMOS, N=93) pts, with differences in mean PASI score (8.9 v 12.5), swollen joint count (SJC) (11.7 v 10.3), PsA duration (5.8 v 9.8 yrs), & PsO duration (16.7 v 20.4 yrs; Table 1). BL serum IL-22 & TNFα levels for pooled treatment groups were higher in TNFi-IR than -naïve pts (p<0.05). At W24, GUS reduced IL-22, IL-17A/F, IL-6, C-reactive protein (CRP), & serum amyloid A protein to similar levels in both cohorts (p<0.05; Figure 1). W24 PASI75 responders had higher BL IL-17F levels with GUS in both cohorts (p<0.05) & higher IL-22 levels in TNFi-IR pts only (p<0.05). A trend of upregulated BL IL-22 expression in W24 ACR20 responders was seen for TNFi-IR pts with GUS (p=0.07).

Table 1.

BL demographics, disease characteristics, & drug use in TNFi-naïve & -IR cohorts with available cytokine data in DISCOVER-1&2 & COSMOS.*

TNFi-naïve (N=251)TNFi-IR (N=93)Age [yrs]47.2 (11.3)48.5 (11.1)Female, n (%)132 (52.6)46 (49.5)Body mass index [kg/m2]29.6 (6.1)30.3 (6.4)Median (range) CRP [mg/dL]0.9 (0.0-12.9)1.0 (0.0-13.2)Log2 IL-22 / TNFα [pg/mL]2.0 (1.4) / 1.1 (0.6)2.5 (1.5) / 1.9 (1.2)Log2 IL-17A / F [pg/mL]-0.4 (1.5) / 1.7 (1.5)-0.1 (1.7) / 2.0 (1.6)SJC [0-66]11.7 (7.1)10.3 (8.3)TJC [0-68]20.3 (13.1)20.6 (14.2)PsA duration [yrs]5.8 (5.9)9.8 (8.2)PsO duration [yrs]16.7 (12.8)20.4 (12.0)PsO Body surface area (%)14.8 (18.6)19.1 (21.3)Investigator’s Global Assessment score [0-4]2.3 (0.9)2.3 (1.0)PASI score [0-72]8.9 (10.6)12.5 (12.0)Enthesitis [Y], n (%)160 (63.7)58 (62.4)csDMARD use [Y], n (%)164 (65.3)62 (66.7)Corticosteroid use (Y), n (%)45 (17.9)19 (20.4)Methotrexate use [Y], n (%)136 (54.2)54 (58.1)

Data are mean (SD) unless otherwise noted. *Pts with serum CRP level ≥0.3 mg/dL, SJC ≥3, & TJC ≥3 (to mimic D1 inclusion criteria1). TJC= tender joint count

Conclusion

Elevated BL IL-22 expression & association between BL IL-22 levels & W24 PASI75 response, & a W24 trend for an association between upregulated BL IL-22 & ACR20 response, in TNFi-IR pts seen in this exploratory analysis may suggest increased involvement of the IL-23 pathway in TNFi-IR pts. GUS showed comparable & significant PD effects for TNFi-naïve & -IR pts, consistent with observed clinical responses.

References

[1]Deodhar A, et al. Lancet. 2020;395:1115-25.

[2]Coates LC, et al. Ann Rheum Dis. 2021;80:140-1.

[3]Mease P, et al. Lancet. 2020;395:1126-36.

Disclosure of Interests

Stefan Siebert Speakers bureau: AbbVie, Biogen, GSK, Janssen, Novartis, UCB, Grant/research support from: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, GSK, Janssen, Novartis, and UCB, Laura Coates Speakers bureau: AbbVie, Amgen, Biogen, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Medac, Novartis, Pfizer and UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Eli Lilly, Gilead, Galapagos, Janssen, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, Pfizer, and UCB, Georg Schett Speakers bureau: AbbVie, Amgen, Bristol Myers Squibb, Eli Lilly, Gilead, Janssen, Novartis, and UCB, Siba P Raychaudhuri Speakers bureau: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, Pfizer, SUN Pharma, and UCB, Consultant of: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, Pfizer, SUN Pharma, and UCB, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, Pfizer, SUN Pharma, and UCB, Warner Chen Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC (a wholly owned subsidiary of Johnson & Johnson), Sheng Gao Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC (a wholly owned subsidiary of Johnson & Johnson), Soumya D Chakravarty Shareholder of: Johnson & Johnson, Employee of: Janssen Scientific Affairs, LLC (a wholly owned subsidiary of Johnson & Johnson), May Shawi Shareholder of: Johnson & Johnson, Employee of: Janssen Pharmaceutical Companies of Johnson & Johnson, Frederic Lavie Shareholder of: Johnson & Johnson, Employee of: Janssen Pharmaceutical Companies of Johnson & Johnson, Elke Theander Shareholder of: Johnson & Johnson, Employee of: Janssen Scientific Affairs, LLC (a wholly owned subsidiary of Johnson & Johnson), Marlies Neuhold Shareholder of: Johnson & Johnson, Employee of: Janssen Scientific Affairs, LLC (a wholly owned subsidiary of Johnson & Johnson), Alexa Kollmeier Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC (a wholly owned subsidiary of Johnson & Johnson), Xie L Xu Shareholder of: Johnson & Johnson, Employee of: Janssen Research & Development, LLC (a wholly owned subsidiary of Johnson & Johnson), Proton Rahman Consultant of: AbbVie, Amgen, Bristol Myers Squibb, Celgene, Eli Lilly, Janssen, Merck, Novartis, Pfizer, and UCB, Grant/research support from: Janssen and Novartis, Philip J Mease Speakers bureau: AbbVie, Amgen, Eli Lilly, Janssen, Novartis, Pfizer, Sun Pharma, and UCB, Consultant of: AbbVie, Aclaris, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Eli Lilly, Galapagos, Gilead, GSK, Inmagene, Janssen, Novartis, Pfizer, Sun Pharma, and UCB, Grant/research support from: AbbVie, Amgen, Bristol Myers Squibb, Eli Lilly, Galapagos, Gilead, Janssen, Novartis, Pfizer, Sun Pharma, and UCB, Atul Deodhar Speakers bureau: AbbVie, Eli Lilly, Janssen, Novartis, Pfizer, and UCB, Consultant of: AbbVie, Amgen, Aurinia, Bristol Myers Squibb, Celgene, Eli Lilly, GSK, Janssen, MoonLake, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Eli Lilly, GSK, Novartis, Pfizer, and UCB

POS0006 IDENTIFICATION OF FIBROTIC AND FIBROLYTIC ENDOTYPES IN RHEUMATIC DISEASE COHORTS

Background

Ankylosing spondylitis (AS), psoriatic arthritis (PsA) and systemic lupus erythematosus (SLE) are distinct diseases with common molecular features, such as an imbalance in fibrolysis and fibrosis of connective and calcified tissues. Type III, IV and VI collagens are abundant in connective tissue, and type I, II and X of the skeletal tissue. Blood biomarkers are available to measure fibrolysis (C1M, C2M, C3M, C4M, C6M, C10C) and fibrosis (PRO-C1, PRO-C2, PRO-C3, PRO-C4, PRO-C6) of these collagens.

Objectives

To profile AS, PsA and SLE patients (pts) using blood biomarkers of collagen formation and degradation.

Methods

Baseline serum samples from consenting pts of the AS (NCT02437162/NCT02438787), PsA (NCT0315828), and SLE (NCT02349061) studies were included in the analyses. Healthy donor samples were acquired from Discovery LS. Biomarkers were measured by immunoassays. Biomarker levels were compared by Kruskal-Wallis test. Before hierarchical clustering (Ward.D2), biomarker levels were log-transformed and standardized by median centering and scaling by median absolute deviation (MAD).

Results

When compared with healthy individuals, VICM was elevated in all indications (although markedly less so in SLE pts). The fibrosis marker PRO-C3 was elevated in all indications vs. healthy, while PRO-C4 and PRO-C6 were elevated only in AS and PsA. The fibrolysis markers C3M, C4M and C6M were elevated in all indications. The cartilage fibrosis marker PRO-C2, but not C2M, was elevated in AS and PsA, but not in SLE, ps. The bone fibrosis marker PRO-C1 was at the level of healthy for all. The fibrolysis marker C1M was elevated in all, while elevated C10C was seen only in PsA and SLE, pts (Table 1). Four clusters (C) of blood markers were extracted (Figure 1). C1 was characterized by low biomarker levels (68% of healthy, 1% of PsA, 3% of SLE pts). C2 was described by high levels of C10C and median levels of VICM (20% of healthy, 12% of AS, 19% of PsA, 42% of SLE pts). C3 was described by median biomarker levels (8% of healthy, 67% of AS, 48% of PsA, 46% of SLE pts). C4 had high biomarker levels (4% of healthy, 21% of AS, 31% of PsA, 9% of SLE pts).

Conclusion

Fibrosis and fibrolysis blood biomarkers were significantly elevated in AS, PsA and SLE pts. Subsets of pts from each indication were found in clusters with either low (C1/2), median (C3) or high (C4) levels of fibrosis/fibrolysis biomarkers. These findings may provide a first step towards precision medicine for guiding the use of anti-inflammatory vs. anti-fibrotic treatments in pts with rheumatological disorders.

Disclosure of Interests

Anne-Christine Bay-Jensen Shareholder of: Nordic Bioscience A/S, Employee of: Nordic Bioscience A/S, Signe Holm Nielsen Shareholder of: Nordic Bioscience A/S, Employee of: Nordic Bioscience A/S, Peder Frederiksen Employee of: Nordic Bioscience A/S, Morten Karsdal Shareholder of: Nordic Bioscience A/S, Employee of: Nordic Bioscience A/S, Warner Chen Employee of: Janssen Research & Development, Sheng Gao Employee of: Janssen Research & Development

POS0969 GENETIC AND MOLECULAR DISTINCTIONS BETWEEN AXIAL PSORIATIC ARTHRITIS AND ANKYLOSING SPONDYLITIS

Background

Psoriatic arthritis (PsA) and ankylosing spondylitis (AS) represent the prototypical spondyloarthritides. PsA patients may also suffer from axial disease (axPsA). Despite overlapping symptoms, axPsA and AS may be distinct disorders with differing clinical manifestations, genetic associations, and radiographic findings.1 These disorders also respond differently to immunomodulatory therapies such as anti-interleukin (IL)-23 inhibitors. While guselkumab, a human monoclonal antibody targeting the IL-23p19 subunit, improved symptoms of axPsA,2 risankizumab, a humanized monoclonal antibody targeting the IL-23p19 subunit, did not show improvement in the primary endpoint of proportion of AS patients achieving an Assessment of SpondyloArthritis International Society 40% (ASAS40) response at week (W) 12.3

Objectives

To understand molecular distinctions between axPsA and AS to differentiate these diseases and guide treatment choice.

Methods

Whole blood and serum samples were collected from consenting patients in the NCT03162796/NCT0315828 studies of guselkumab in PsA and the NCT02437162/NCT02438787 studies of ustekinumab in AS. axPsA patients were investigator-verified as having magnetic resonance imaging- or pelvic x-ray-confirmed sacroiliitis at screening (locally read). Human leukocyte antigen (HLA) genotypes were determined by RNA sequencing, limited to Caucasian patients to reduce genetic variability,4 and select serum cytokine levels were analyzed alongside samples from healthy individuals. Differential prevalence of HLA alleles in axPsA versus AS was determined using a Fisher’s Exact test. Statistical significance of differential baseline serum cytokine expression among axPsA versus non-axPsA versus AS patients, and of guselkumab effect on serum cytokine reduction versus placebo among axPsA and non-axPsA patients, were determined with a generalized linear model performed on log2-transformed data. Biomarker data from guselkumab every-4-weeks and every-8-weeks treatment arms were pooled.

Results

Among the 186/234 Caucasian axPsA/AS patients with available data, 34%/15% were female, 70%/14% used methotrexate at baseline, mean serum C-reactive protein (CRP) levels were 2.8/2.4 mg/dL and mean Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores were 6.4/7.5, respectively. Aside from race, baseline demographics and disease characteristics were representative of the overall population. The prevalence of class I HLA allele -B27, -C01, and -C02 carriers was significantly lower in axPsA than AS patients (30.7% versus 92.3%, p<0.001; 5.9% versus 31.6%, p<0.001; and 28.0% versus 62.0%, p<0.001, respectively), while the prevalence of HLA-C06 was significantly higher in axPsA than AS populations (36.0% versus 8.6%, p<0.001). Baseline serum levels of IL-17A and IL-17F were significantly higher in axPsA (N=71) than in AS (N=58) patients (p<0.01 and p<0.001, respectively). Comparable IL-17A/F expression was seen for axPsA and non-axPsA (N=229) patients (both p=not significant). Significant and comparable reductions from baseline in serum IL-17A/F in axPsA and non-axPsA patients were seen with guselkumab treatment (axPsA N=41, non-axPsA N=160) versus placebo (axPsA N=30, non-axPsA N=69) at W4/24 (all p<0.05).

Conclusion

Adults with axPsA and AS exhibit different genetic risk factors and serum IL-17 levels, supporting the concept of distinct disorders. Guselkumab demonstrated significant pharmacodynamic effects in axPsA patients that aligned with such effects in non-axPsA patients, consistent with observed clinical improvement.2

References

[1]Feld et al. Nat Rev Rheumatol. 2018;14(6):363-371.

[2]Mease et al. Lancet Rheumatol. 2021;3(10)E715-E723.

[3]Baeten et al. Ann Rheum Dis. 2018;77(9):1295-1302.

[4]Buchkovich et al. Genome Med. 2017;9(86).

Disclosure of Interests

Arthur Kavanaugh Consultant of: AbbVie, Amgen, BMS, Genentech, Janssen, Eli Lilly, Merck, Novartis, Pfizer and UCB, Xenofon Baraliakos Consultant of: AbbVie, Chugai, Eli Lilly, Galapagos, Janssen, MSD, Novartis, Pfizer, Roche, and UCB, Grant/research support from: AbbVie, MSD, and Novartis, Sheng Gao Employee of: Janssen Research & Development, LLC, and may own stock or stock options in Johnson & Johnson, Warner Chen Employee of: Janssen Research & Development, LLC, and may own stock or stock options in Johnson & Johnson, Kristen Sweet Employee of: Janssen Research & Development, LLC, and may own stock or stock options in Johnson & Johnson, Soumya D Chakravarty Employee of: Janssen Scientific Affairs, LLC, and may own stock or stock options in Johnson & Johnson, Qingxuan Song Employee of: Janssen Research & Development, LLC, and may own stock or stock options in Johnson & Johnson, May Shawi Employee of: Janssen Pharmaceutical Companies of Johnson & Johnson, and may own stock or stock options in Johnson & Johnson, Frank Behrens Speakers bureau: AbbVie, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Chugai, Eli Lilly, Galapagos, Genzyme, Gilead, Janssen, MSD, Novartis, Pfizer, Roche, Sanofi, and UCB, Consultant of: AbbVie, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Chugai, Eli Lilly, Galapagos, Genzyme, Gilead, Janssen, MSD, Novartis, Pfizer, Roche, Sanofi, and UCB, Grant/research support from: Celgene, Chugai, Janssen, Pfizer, and Roche, Proton Rahman Consultant of: AbbVie, Amgen, Bristol Myers Squibb, Celgene, Eli Lilly, Janssen, Merck, Novartis, Pfizer, and UCB, Grant/research support from: Janssen, research grants from Janssen and Novartis

POS0308 EFFECT OF GUSELKUMAB ON SERUM BIOMARKERS IN PSORIATIC ARTHRITIS PATIENTS WITH INADEQUATE RESPONSE OR INTOLERANCE TO TUMOR NECROSIS FACTOR INHIBITORS: RESULTS FROM THE COSMOS STUDY

Background

Guselkumab (GUS), a selective IL-23 inhibitor, is efficacious in treating bio-naïve and TNFi-experienced active PsA patients (pts).1.2 In the COSMOS study of active PsA pts with lack of efficacy/intolerance, i.e., inadequate response (IR), to 1-2 TNFi, GUS demonstrated significantly greater response rates and mean improvements in PsA signs and symptoms vs. placebo (PBO) at Week (W) 24.3

Objectives

Evaluate baseline (BL) serum levels of pro-inflammatory biomarkers (CRP, serum amyloid A [SAA], TNFα, IFNɣ, IL-6, IL-10, IL-17F, IL-17A, IL-22) and their relationship to BL disease activity, GUS treatment (tx), and clinical response in COSMOS TNFi-IR pts.

Methods

TNFi-IR pts ≥18 yrs with active PsA (≥3 swollen & ≥3 tender joint counts [SJC/TJC]) were randomized 2:1 to GUS 100 mg every 8 W (Q8W) through W44 or PBO with early escape (W16) or crossover (W24) to GUS Q8W. Samples for serum biomarker analyses, collected at W0, 4, 16, 24, and 48 from consenting pts, were compared with healthy controls (HC; independent of COSMOS). Associations between early biomarker changes and BL disease activity, GUS tx, and clinical response at W24 were assessed.

Results

Among 285 COSMOS pts, 50/95 PBO and 100/190 GUS pts had available biomarker data. BL characteristics of the biomarker cohort were similar to the overall COSMOS population and well balanced across tx arms. At BL, levels of TNFα, IFNɣ, IL-6, IL-10, IL-17A, IL-17F, and IL-22 were significantly upregulated in TNFi-IR pts vs. HC (Table 1). IL-6, CRP, and SAA levels were associated with BL joint disease severity per Disease Activity Score (DAS) 28-CRP (but not with SJC [0-66]/TJC [0-68]). IL-17A and IL-17F levels were associated with BL PASI score. Through W24, significant decreases from BL in levels of CRP, SAA, IL-6, IL-17A, IL-17F, and IL-22 were seen in GUS-, but not PBO-tx pts. Reductions in IL-17A, IL-17F and IL-22 with GUS were significant by W4, decreased further by W16, and were sustained through W24 and W48. In GUS-tx pts, serum levels of IL-17F (from W16) and IL-22 (from W4) were not significantly different vs. HC. At W48, reductions in these same markers were seen in PBO-tx pts who crossed over to GUS at W16/24 (Figure 1; IL-17A, IL-17F, & IL-22 data shown). In these TNFi-IR pts, GUS-tx pts achieving ACR20 at W24 exhibited higher IL-22 and IFNɣ levels at BL than nonresponders (NR). All other biomarkers evaluated were not significantly associated with ACR20 response to GUS. In the subset of pts with IGA of psoriasis assessed, BL IL-6 and SAA levels were upregulated in W24 IGA 0/1 responders (R) vs. NR in the GUS arm. ACR20 and IGA 0/1 R at W24 exhibited an early greater reduction in IL-6 expression (at W4) than did respective NR in the GUS arm. No BL biomarkers were associated with ACR50 or PASI75 responses to GUS at W24.

Table 1.

Select Serum Biomarkers at BL in TNFi-IR pts vs. HC▫

Biomarker, pg/mLHC N=24TNFi-IR N=150Fold differencep-valueCRP22.1 (1.5)22.8 (2.2)1.60.2895SAA21.7 (1.2)22.8 (2.4)2.10.0794IL-60.07 (1.1)0.98 (1.7)1.90.0314*IL-10-2.3 (1.1)-1.7 (1.0)1.50.0272*IL-17A-2.1 (1.3)-0.3 (1.5)3.3<0.0001*IL-17F0.05 (1.1)1.3 (1.5)2.40.0007*IL-221.9 (1.1)3.1 (1.3)2.40.0002*TNFα0.5 (0.75)1.4 (1.1)1.80.0002*IFNɣ2.4 (0.84)2.9 (1.3)1.50.0259*

Data are mean (SD); *p<0.05 and |fold difference| >1.4; ▫adjusted for confounding factors age & sex.

Conclusion

GUS-tx TNFi-IR pts showed response-specific associations with BL biomarkers (IL-22, IFNɣ, IL-6, and SAA). GUS resulted in decreased levels of elevated CRP, SAA, IL-6, IL-17A, IL-17F, and IL-22, while no significant change was observed with PBO tx. Reductions in these biomarkers were evident as early as W4 and approximated levels seen in HC from W16 onward (W4 for IL-22), suggesting apparent normalization of effector cytokines associated with the IL-23/Th17 axis following GUS tx.

References

[1]Deodhar A et al. Lancet 2020;395:1115-25.

[2]Mease PJ et al. Lancet 2020;395:1126-36.

[3]Coates LC et al. doi:10.1136/annrheumdis-2021-220991.

Disclosure of Interests

Georg Schett Speakers bureau: Amgen, AbbVie, Bristol Myers Squibb, Eli Lilly, Gilead, Janssen, Novartis and UCB, Warner Chen Shareholder of: Janssen, Employee of: Janssen, Sheng Gao Shareholder of: Janssen, Employee of: Janssen, Soumya D Chakravarty Shareholder of: Janssen, Employee of: Janssen, May Shawi Shareholder of: Janssen, Employee of: Janssen, Frederic Lavie Shareholder of: Janssen, Employee of: Janssen, Elke Theander Shareholder of: Janssen, Employee of: Janssen, Marlies Neuhold Shareholder of: Janssen, Employee of: Janssen, Laura Coates Speakers bureau: AbbVie, Amgen, Biogen, Celgene, Eli Lilly, Galapagos, Gilead, Janssen, Medac, Novartis, Pfizer and UCB, Consultant of: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Eli Lilly, Gilead, Galapagos, Janssen, Novartis, Pfizer, and UCB, Grant/research support from: AbbVie, Amgen, Celgene, Eli Lilly, Janssen, Novartis, Pfizer, and UCB, Stefan Siebert Speakers bureau: AbbVie, Biogen, GSK, Janssen, Novartis, UCB, Grant/research support from: AbbVie, Amgen, Boehringer Ingelheim, Bristol Myers Squibb, GSK, Janssen, Novartis, UCB

VE-cadherin enables trophoblast endovascular invasion and spiral artery remodeling during placental development

During formation of the mammalian placenta, trophoblasts invade the maternal decidua and remodel spiral arteries to bring maternal blood into the placenta. This process, known as endovascular invasion, is thought to involve the adoption of functional characteristics of vascular endothelial cells (ECs) by trophoblasts. The genetic and molecular basis of endovascular invasion remains poorly defined, however, and whether trophoblasts utilize specialized endothelial proteins in an analogous manner to create vascular channels remains untested. Vascular endothelial (VE-)cadherin is a homotypic adhesion protein that is expressed selectively by ECs in which it enables formation of tight vessels and regulation of EC junctions. VE-cadherin is also expressed in invasive trophoblasts and is a prime candidate for a molecular mechanism of endovascular invasion by those cells. Here, we show that VE-cadherin is required for trophoblast migration and endovascular invasion into the maternal decidua in the mouse. VE-cadherin deficiency results in loss of spiral artery remodeling that leads to decreased flow of maternal blood into the placenta, fetal growth restriction, and death. These studies identify a non-endothelial role for VE-cadherin in trophoblasts during placental development and suggest that endothelial proteins may play functionally unique roles in trophoblasts that do not simply mimic those in ECs.

NIR-II Fluorescence Imaging Using Indocyanine Green Provides Early Prediction of Skin Avulsion-Injury in a Porcine Model

Purpose

Currently, skin avulsion–injury reconstruction is mainly based on subjective evaluation of traditional clinical signs. It frequently results in unnecessary tissue loss and incomplete debridement-related infection. This pilot study aimed to develop a novel near-infrared (NIR) II fluorescence imaging method to assess avulsed skin–perfusion status and thus predict its outcome early.

Methods

Skin avulsion–injury models were established by avulsing 10×4 cm pedicled flaps on porcine hindlimbs. A clinically available improved NIR-Ι/II multispectral imaging system was applied for NIR imaging using indocyanine green (ICG) fluorescence. Continuous NIR-wavelength filters and dynamic imaging were used to investigate optimal imaging conditions and time window. NIR-Ι/II imaging was synchronously conducted for quality comparison of the two methods. Visual inspection and histological studies were used for assessing the final outcome of avulsed skin.

Results

NIR-II fluorescence imaging with a 1,100 nm filter obtained satisfactory performance and reached maximum fluorescence intensity at 1 minute after ICG injection. NIR-II imaging clearly visualized the microvascular network in vascularized avulsed skin and revealed “dark areas” in nonvascularized avulsed skin in a real-time fashion. NIR-II fluorescence imaging demonstrated higher resolution than NIR-I imaging, as indicated by ae higher signal-to-background ratio (2.11) and lower full width at half maximum (6.50614). The dark area of avulsed skin on imaging finally developed to necroses that were confirmed by histology.

Conclusion

NIR-II real-time fluorescence imaging clearly maps the microvascular network and shows the perfusion status of avulsed skin at higher resolution than traditional NIR-I imaging, and thus precisely predicts the outcome of avulsed skin early.

[SARS-CoV-2 with transcription regulatory sequence motif mutation poses a greater threat]

OBJECTIVE

To analyze the mutations in transcription regulatory sequences (TRSs) of coronaviruss (CoV) to provide the basis for exploring the patterns of SARS-CoV-2 transmission and outbreak.

METHODS

A combined evolutionary and molecular functional analysis of all sets of publicly available genomic data of viruses was performed.

RESULTS

A leader transcription regulatory sequence (TRS-L) usually comprises the first 60-70 nts of the 5' UTR in a CoV genome, and the body transcription regulatory sequences (TRS-Bs) are located immediately upstream of the genes other than ORF1a and 1b. In each CoV genome, the TRS-L and TRS-Bs share a specific consensus sequence, namely the TRS motif. Any changes of nucleotide residues in the TRS motifs are defined as TRS motif mutations. Mutations in the TRS-L or multiple TRS-Bs result in superattenuated variants. The spread of super-attenuated variants may cause an increase in asymptomatic or mild infections, prolonged incubation periods and a decreased detection rate of the viruses, thus posing new challenges to SARS-CoV-2 prevention and control. The super-attenuated variants also increase their possibility of long-term coexistence with humans. The Delta variant is significantly different from all the previous variants and may lead to a large-scale transmission. The Delta variant (B.1.617.2) with TRS motif mutation has already appeared and shown signs of spreading in Singapore, which, and even the Southeast Asia, may become the new epicenter of the next wave of SARS-CoV-2 outbreak.

CONCLUSION

TRS motif mutation will occur in all variants of SARS-CoV-2 and may result in super-attenuated variants. Only super-attenuated variants with TRS motif mutations will eventually lose the abilities of cross-species transmission and causing outbreaks.

Label-free surface enhanced Raman spectroscopy analysis of blood serum via coffee ring effect for accurate diagnosis of cancers

Surface-enhanced Raman spectroscopy (SERS) is considered as an ultrasensitive, non-invasive as well as rapid detection technology for cancer diagnosis. In this study, we developed a novel blood serum analysis strategy using coffee ring effect-assisted label-free SERS for different types of cancer screening. Additionally, the pretreated Ag nanoparticles (Ag NPs) were mixed with the serum from liver cancer patients (n = 40), prostate cancer patients (n = 32) and healthy volunteers (n = 30) for SERS measurement. The droplets of Ag NPs-serum mixture formed the coffee ring on the peripheral after air-drying, and thus extremely enhancing Raman signal and ensuring the stability and reliability of SERS detection. Partial least square (PLS) and support vector machine (SVM) algorithms were utilized to establish the diagnosis model for SERS spectra data classifying, yielding the high diagnostic accuracy of 98.04% for normal group and two types of cancers simultaneously distinguishing. More importantly, for the unknown testing set, an ideal diagnostic accuracy of 100% could be achieved by PLS-SVM algorithm for differentiating cancers from the normal group. The results from this exploratory work demonstrate that serum SERS detection combined with PLS-SVM diagnostic algorithm and coffee ring effect has great potential for the noninvasive and label-free detection of cancer.

Fully automated quantification of LV regional wall motion from echocardiograms to detect myocardial infarction

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Ultromics Ltd

Background

Myocardial wall motion analysis from echocardiography allows precise assessment of cardiac contractile function. Strain, which assesses myocardial deformation, has been shown to enable earlier detection of myocardial disease [1]. Current analysis software packages [2] use semi-automated methods to compute strain, which frequently require manual endocardial delineation and iterative contour adjustment based on tracking results, respectively, causing significant variability.

Purpose

We present a fully automated pipeline for tracking left ventricular (LV) wall motion to quantify global and segmental longitudinal strain from 2D echocardiograms, and go on to validate the pipeline with an openly available myocardial infarction (MI) dataset.

Methods

We applied our existing deep learning-based automated contouring method [3] to delineate the endocardial border in the A4C, A2C and A3C views and combined this with spline-based elastic image registration to track LV motion through time. We sampled points from a region of interest initiated from the endocardial border at the end-diastolic (ED) frame, and tracked subsequent motion by recomputing updated positions of all sample points based on each frame‘s displacement field, enabling us to both track the myocardium throughout the cardiac cycle and calculate longitudinal strain relative to the ED frame. The automated endocardial contour was used to regularise the process. The pipeline was independently tested on the HMC-QU dataset [4] which was downloaded from Kaggle and consists of a single cardiac cycle from the A4C view from 160 patients who were diagnosed with an acute MI and underwent echocardiography either prior to percutaneous coronary intervention or within 24 hours of undergoing the procedure; the dataset includes the labels of ED and end-systolic (ES) frames, as well as the presence of an MI in 6 segments excluding the apical cap (Fig 1a), as determined by the consensus of cardiologists from HMC Hospital in Qatar. The Wilcoxon signed-rank test was used to compare peak strain between the MI and non-MI segments; ROC curves were computed to compare the performance of the automatically derived peak longitudinal strain against the MI labels.

Results

Fig 1b shows ROC curves of peak segmental longitudinal strain for detecting MI, with the best performance in the mid-anterolateral segment (AUC 0.84), and a lower performance for basal segments than mid and apical segments, consistent with known variation in clinical practice [5]. Fig 2 shows that peak longitudinal strain computed from our pipeline was statistically significantly more positive in segments with an MI.

Conclusions

We present a fully automated pipeline for calculating segmental strain across a cardiac cycle to identify infarcted segments without any observer variability. Clinical application of this method has the potential to identify and monitor regional myocardial function and benefit patient management. Abstract Figure. Fig1. ROC of peak longitudinal strains  Abstract Figure. Fig2.Boxplot of peak longitudinal strain

Dynamically monitoring lymphatic and vascular systems in physiological and pathological conditions of a swine model via a portable NIR-II imaging system with ICG

Objective: NIR-II imaging with indocyanine green (ICG) has been clinically used in liver tumor resection. However, few data are available concerning the application of ICG-NIR-II in lymphatic and vascular systems in clinic. To expand the application and promote the clinical translation of this approach, we aimed to investigate the feasibility of ICG-NIR-II imaging for monitoring both lymphatic and vascular systems in physiological and pathological conditions using a swine model and compared it to ICG-NIR-I imaging. Methods: we constructed a portable NIR-II imaging system suitable for large animals. Different simulated clinical scenarios in lymphatic and vascular systems of pigs, including lymphatic drainage, lymphorrhea, lymphatic obstruction, lymphatic reconstruction in flaps, venous thrombus formation and vascular anastomosis were modeled to evaluate the reliability of our NIR-II imaging system and the imaging quality of ICG in the NIR-I/II window. Results: Under different simulated clinical scenarios, our portable NIR-II imaging system showed good reliability for pigs. With the help of the portable imaging system, dynamical visualization of lymph vessels, lymph nodes and blood vessels of pigs in different clinical scenarios could be achieved in NIR-II imaging by using the tail fluorescence of ICG. Moreover, ICG-NIR-II imaging has lower background fluorescence and higher resolution than ICG-NIR-I imaging. Conclusions: We demonstrated the first application of a portable NIR-II imaging system for dynamically monitoring both lymphatic and vascular systems in physiological and pathological conditions using a swine model. Our study indicates that ICG-NIR-II imaging be a promising approach for the diagnosis of malfunctions in lymphatic and vascular systems and the surgical navigation of microsurgery and reconstructive surgery.