Induction of mitochondrial recycling reverts age-associated decline of the hematopoietic and immune systems

Aging compromises hematopoietic and immune system functions, making older adults especially susceptible to hematopoietic failure, infections and tumor development, and thus representing an important medical target for a broad range of diseases. During aging, hematopoietic stem cells (HSCs) lose their blood reconstitution capability and commit preferentially toward the myeloid lineage (myeloid bias)1,2. These processes are accompanied by an aberrant accumulation of mitochondria in HSCs3. The administration of the mitochondrial modulator urolithin A corrects mitochondrial function in HSCs and completely restores the blood reconstitution capability of 'old' HSCs. Moreover, urolithin A-supplemented food restores lymphoid compartments, boosts HSC function and improves the immune response against viral infection in old mice. Altogether our results demonstrate that boosting mitochondrial recycling reverts the aging phenotype in the hematopoietic and immune systems.

Lymphatic flow through (LyFT) ALT flap: an original solution to reconstruct soft tissue loss with lymphatic leakage or lower limb lymphedema

INTRODUCTION

The lympho-venous shunt using the distal vein of ALT flap pedicle allowed at the same time the coverage of the inguinal defects and to perform lymphovenous shunt into a run-in vein of the descending branch of the lateral circumflex femoral pedicle, draining the lymph through the flap pedicle. Surgical technique, complications and final outcomes (both clinical and lymphoscintigraphic) are reported.

METHODS

Five patients (45.8 y.o.[22-70]) with groin soft tissue loss with lymphatic leakage or lower limb lymphedema, benefited of the described technique. The ALT flap was used to cover the defect and, at the same time, we could perform a lymphovenous shunt between afferent lymphatics to the thigh and the descending branch of the lateral circumflex femoral pedicle, distal to the perforator nourishing the flap. Clinical and lymphoscintigraphic assessment of the limbs, cease of lymphorrhea or cellulitis/lymphangitis episodes, eventual downstaging of physiologic/physical therapy were recorded. LYMphatic Quality Of Life in leg (LYMQoLLeg) and patient satisfaction were evaluated.

RESULTS

Average flap size was 88.8cm² (range 84-126). The mean number of multi-lymphovenous anastomosis (MLVA) performed was 1.8 (range 1-3) per patient with 1-3 lymphatics shunted into each vein. Only one hemato-seroma requiring surgical revision. Mean improvement of perometer values was 48.2% (range 27.7-67.7) with an average follow-up of 13.6 months (range 12-17). Lymphoscintigraphy showed disappearing of the lymphatic leak and lymphedema with a high satisfaction of LYMQoL score.

DISCUSSION

The combination of pedicle flap with lympho-venous bypass as lymphatic derivation concept, improving the chronic morbidity scenarios of lymphatic complications.

MarrowQuant 2.0: A Digital Pathology Workflow Assisting Bone Marrow Evaluation in Experimental and Clinical Hematology

Bone marrow (BM) cellularity assessment is a crucial step in the evaluation of BM trephine biopsies for hematologic and nonhematologic disorders. Clinical assessment is based on a semiquantitative visual estimation of the hematopoietic and adipocytic components by hematopathologists, which does not provide quantitative information on other stromal compartments. In this study, we developed and validated MarrowQuant 2.0, an efficient, user-friendly digital hematopathology workflow integrated within QuPath software, which serves as BM quantifier for 5 mutually exclusive compartments (bone, hematopoietic, adipocytic, and interstitial/microvasculature areas and other) and derives the cellularity of human BM trephine biopsies. Instance segmentation of individual adipocytes is realized through the adaptation of the machine-learning-based algorithm StarDist. We calculated BM compartments and adipocyte size distributions of hematoxylin and eosin images obtained from 250 bone specimens, from control subjects and patients with acute myeloid leukemia or myelodysplastic syndrome, at diagnosis and follow-up, and measured the agreement of cellularity estimates by MarrowQuant 2.0 against visual scores from 4 hematopathologists. The algorithm was capable of robust BM compartment segmentation with an average mask accuracy of 86%, maximal for bone (99%), hematopoietic (92%), and adipocyte (98%) areas. MarrowQuant 2.0 cellularity score and hematopathologist estimations were highly correlated (R² = 0.92-0.98, intraclass correlation coefficient [ICC] = 0.98; interobserver ICC = 0.96). BM compartment segmentation quantitatively confirmed the reciprocity of the hematopoietic and adipocytic compartments. MarrowQuant 2.0 performance was additionally tested for cellularity assessment of specimens prospectively collected from clinical routine diagnosis. After special consideration for the choice of the cellularity equation in specimens with expanded stroma, performance was similar in this setting (R² = 0.86, n = 42). Thus, we conclude that these validation experiments establish MarrowQuant 2.0 as a reliable tool for BM cellularity assessment. We expect this workflow will serve as a clinical research tool to explore novel biomarkers related to BM stromal components and may contribute to further validation of future digitalized diagnostic hematopathology workstreams.

The Performances of Conventional Titanium and Silver-Coated Megaprostheses in Non-oncological and Post-oncological Patients: An Analysis of Infection Failures in 142 Patients

BACKGROUND

Megaprostheses are one of the preferred choices of reconstruction after tumor resection. Periprosthetic joint infections are one of the most serious complications of joint prostheses surgeries. In this study, our aim was to analyze the efficacy of silver-coated megaprostheses in reducing the risk of prosthesis-related infection.

METHODS

One hundred forty-two patients who had undergone implantation of a mega-endoprosthesis for non-neoplastic or post-neoplastic conditions were included in this retrospective study. The end-point of the survival analysis was the prosthesis failure due to infection.

RESULTS

Thirty-eight patients had undergone implantation of a silver-coated megaprosthesis and 104 patients a megaprosthesis without silver coating. The survival analysis showed an overall infection-free survival rate of 82.3% at five years and 61.9% at 10 years. Silver-coated prostheses had an HR of 0.72 (95% CI: 0.26-2.05; P=0.54).

CONCLUSION

Implantation of a silver-coated mega-prosthesis in non-oncological patients did not significantly reduce the risk of prosthesis-related infection.

Case Report: Tyrosine Kinase Inhibitors Induced Lymphadenopathy in Desmoid Tumor Patients

Tyrosine kinase inhibitors (TKIs) are nowadays a valuable treatment of desmoid tumors, a rare mesenchymal neoplasm. Although many side effects of imatinib and pazopanib, commonly or rarely occurring, have been described, reactional lymphadenopathy has not yet been reported. In this publication, we report two cases of patients with desmoid tumors, treated with pazopanib and imatinib, who developed reactional lymphadenopathy. As this side effect is presented as a newly formed mass, it can result in new diagnostic questions and added imaging tests and can even lead to discontinuation of the treatment. This report may help the clinicians facing similar problems adopt a "watch and wait" approach.

Life or limb: an international qualitative study on decision making in sarcoma surgery during the COVID-19 pandemic

OBJECTIVES

The COVID-19 pandemic is unprecedented as a global crisis over the last century. How do specialist surgeons make decisions about patient care in these unprecedent times?

DESIGN

Between April and May 2020, we conducted an international qualitative study. Sarcoma surgeons from diverse global settings participated in 60 min interviews exploring surgical decision making during COVID-19. Interview data were analysed using an inductive thematic analysis approach.

SETTING

Participants represented public and private hospitals in 14 countries, in different phases of the first wave of the pandemic: Australia, Argentina, Canada, India, Italy, Japan, Nigeria, Singapore, Spain, South Africa, Switzerland, Turkey, UK and USA.

PARTICIPANTS

From 22 invited sarcoma surgeons, 18 surgeons participated. Participants had an average of 19 years experience as a sarcoma surgeon.

RESULTS

17/18 participants described a decision they had made about patient care since the start of the pandemic that was unique to them, that is, without precedence. Common to 'unique' decisions about patient care was uncertainty about what was going on and what would happen in the future (theme 1: the context of uncertainty), the impact of the pandemic on resources or threat of the pandemic to overwhelm resources (theme 2: limited resources), perceived increased risk to self (theme 3: duty of care) and least-worst decision making, in which none of the options were perceived as ideal and participants settled on the least-worst option at that point in time (theme 4: least-worst decision making).

CONCLUSIONS

In the context of rapidly changing standards of justice and beneficence in patient care, traditional decision-making frameworks may no longer apply. Based on the experiences of surgeons in this study, we describe a framework of least-worst decision making. This framework gives rise to actionable strategies that can support decision making in sarcoma and other specialised fields of surgery, both during the current crisis and beyond.

A live single-cell reporter assay links intratumor heterogeneity to metastatic proclivity in Ewing sarcoma

Targeting of the most aggressive tumor cell subpopulations is key for effective management of most solid malignancies. However, the metastable nature of tumor heterogeneity, which allows cells to transition between strong and weak tumorigenic phenotypes, and the lack of reliable markers of tumor-promoting properties hamper identification of the most relevant cells. To overcome these obstacles, we designed a functional microRNA (miR)-based live-cell reporter assay to identify highly tumorigenic cells in xenotransplants of primary Ewing sarcoma (EwS) 3D cultures. Leveraging the inverse relationship between cell pluripotency and miR-145 expression, we successfully separated highly tumorigenic, metastasis-prone (miR-145low) cells from poorly tumorigenic, nonmetastatic (miR-145high) counterparts. Gene expression and functional studies of the two cell populations identified the EPHB2 receptor as a prognostic biomarker in patients with EwS and a major promoter of metastasis. Our study provides a simple and powerful means to identify and isolate tumor cells that display aggressive behavior.

Acute leg compartment syndrome after CT-guided core needle biopsy of a giant cell tumor of the proximal fibula

Imaging-guided percutaneous core needle biopsy (CNB) is the preferred diagnostic method for bone and soft tissue tumors. In less than 1% of cases, complications are clinically significant and include mainly haema-toma and bleeding. We present a case of acute compartment syndrome (ACS) following CNB of the proximal fibula. A 26-year-old female patient was referred to our sarcoma center with a suspicion of giant cell tumor (GCT) of the proximal fibula. The CT-guided CNB under local anesthesia had caused transient severe pain irradiating to the foot, rapidly subsiding after correction of the needle trajectory. The patient was discharged on the same day without residual symptoms. She presented at the emergency department 48 hours later with severe leg pain and swelling. Compartment pressure was elevated. Urgent fasciotomies were performed, revealing muscle edema, without significant haematoma. Postoperatively, paresthesia improved progressively and the patient regained a normal neurologic status within 4 months. Pathologic analysis confirmed the diagnosis of GCT, which was resected after neoadjuvant denosumab therapy. At the 2-year follow up visit, the patient still presented pain at exertion, but had no objective neurological sequela. ACS is not a well-known complication of CNB in the diagnosis of bone tumors. This rare complication might be diagnosed too late, or even missed, due to pre-existing pain, which can sometimes be severe in GCT, and to the usually short post-procedure surveillance in an outpatient procedure.

The NAD-Booster Nicotinamide Riboside Potently Stimulates Hematopoiesis through Increased Mitochondrial Clearance

It has been recently shown that increased oxidative phosphorylation, as reflected by increased mitochondrial activity, together with impairment of the mitochondrial stress response, can severely compromise hematopoietic stem cell (HSC) regeneration. Here we show that the NAD⁺-boosting agent nicotinamide riboside (NR) reduces mitochondrial activity within HSCs through increased mitochondrial clearance, leading to increased asymmetric HSC divisions. NR dietary supplementation results in a significantly enlarged pool of progenitors, without concurrent HSC exhaustion, improves survival by 80%, and accelerates blood recovery after murine lethal irradiation and limiting-HSC transplantation. In immune-deficient mice, NR increased the production of human leucocytes from hCD34+ progenitors. Our work demonstrates for the first time a positive effect of NAD⁺-boosting strategies on the most primitive blood stem cells, establishing a link between HSC mitochondrial stress, mitophagy, and stem-cell fate decision, and unveiling the potential of NR to improve recovery of patients suffering from hematological failure including post chemo- and radiotherapy.

Does candidate for plate fixation selection improve the functional outcome after midshaft clavicle fracture? A systematic review of 1348 patients

INTRODUCTION

The hypothesis of this study was that patient selection for midshaft clavicle fracture (open reduction internal fixation with plate versus conservative) would give better functional outcome than random treatment allocation.

METHODS

We performed a systematic literature search for primary studies providing functional score and non-union rate after conservative or surgical management of midshaft clavicle fractures. Six randomized controlled trial and 19 non-randomized controlled trial studies encompassing a total of 1348 patients were included.

RESULTS

Patients treated with surgical management were found to have statistically superior Constant scores in non-randomized controlled trials than in randomized controlled trials (94.76 ± 6.4 versus 92.49 ± 6.2; p < 0.0001). For conservative treatment, randomized controlled trials were found to have significantly better functional outcome. The prevalence of non-union (6.1%) did not show significant statistical difference between non-randomized controlled trial and randomized controlled trial studies. The functional outcome after surgical management was significantly higher than after conservative management in both randomized controlled trial and non-randomized controlled trial groups. The non-union rate after surgery (1.1% for both non-randomized controlled trial and randomized controlled trial) was significantly lower than following conservative treatment (9.9% non-randomized controlled trial versus 15.1% randomized controlled trial).

DISCUSSION

This review shows that patient selection for surgery may influence functional outcome after midshaft clavicle fracture. Our results also confirm that plate fixation provides better functional outcome and lower non-union rate.

ALT flap with vascularized fascia lata for one-stage functional patellar tendon reconstruction

INTRODUCTION

Composite anterolateral thigh (ALT) flap with vascularized fascia lata can reconstitute patellar tendon integrity and knee soft tissue coverage in one stage. However, long-term evidence of outcomes is lacking. This work analyzes long-term functional results, compares subtotal and total reconstruction of patellar tendon, and assesses the respective function of the extensor apparatus.

PATIENTS AND METHODS

Outcomes of reconstruction using 10 ALT flaps in 9 patients (age range 21-87 years) were analyzed (mean follow-up 30 ± 6 months). Knee Society Scores, isometric knee extensor strength (M1-M5), and sensory recovery were evaluated, together with active range of motion and extensor lag of the reconstructed limb, compared to contralateral.

RESULTS

Ten flaps were used for tendon replacement in 9 patients. Eight (80%) free flaps and 2 (20%) propeller distally based flaps were used. Complications requiring the harvest of a second flap were seen in 2 patients. All patients could return to their daily activities without the use of walking supports. Mean active ROM was 94.4° with an extensor lag of 9.4°, without a significant difference between partial and total patellar tendon reconstruction. The mean knee and functional scores of the Knee Society were 81/100 and 77/100, respectively.

CONCLUSION

Composite ALT flap with fascia lata can satisfy the twofold needs of functional restoration and soft tissue coverage, thus ensuring stable results in total and subtotal knee extensor mechanism reconstruction. Distally based flaps should be carefully considered, as they lead to higher complication rates.

Comparison of peripheral nerve blockade characteristics between non-diabetic patients and patients suffering from diabetic neuropathy: a prospective cohort study

Animal data have demonstrated increased block duration after local anaesthetic injections in diabetic rat models. Whether the same is true in humans is currently undefined. We, therefore, undertook this prospective cohort study to test the hypothesis that type-2 diabetic patients suffering from diabetic peripheral neuropathy would have increased block duration after ultrasound-guided popliteal sciatic nerve block when compared with patients without neuropathy. Thirty-three type-2 diabetic patients with neuropathy and 23 non-diabetic control patients, scheduled for fore-foot surgery, were included prospectively. All patients received an ultrasound-guided popliteal sciatic nerve block with a 30 ml 1:1 mixture of lidocaine 1% and bupivacaine 0.5%. The primary outcome was time to first opioid request after block procedure. Secondary outcomes included the time to onset of sensory blockade, and pain score at rest on postoperative day 1 (numeric rating scale 0-10). These outcomes were analysed using an accelerated failure time regression model. Patients in the diabetic peripheral neuropathy group had significantly prolonged median (IQR [range]) time to first opioid request (diabetic peripheral neuropathy group 1440 (IQR 1140-1440 [180-1440]) min vs. control group 710 (IQR 420-1200 [150-1440] min, p = 0.0004). Diabetic peripheral neuropathy patients had a time ratio of 1.57 (95%CI 1.10-2.23, p < 0.01), experienced a 59% shorter time to onset of sensory blockade (median time ratio 0.41 (95%CI 0.28-0.59), p < 0.0001) and had lower median (IQR [range]) pain scores at rest on postoperative day 1 (diabetic peripheral neuropathy group 0 (IQR 0-1 [0-5]) vs. control group 3 (IQR 0-5 [0-9]), p = 0.001). In conclusion, after an ultrasound-guided popliteal sciatic nerve block, patients with diabetic peripheral neuropathy demonstrated reduced time to onset of sensory blockade, with increased time to first opioid request when compared with patients without neuropathy.

Docetaxel and gemcitabine combination in 133 advanced soft-tissue sarcomas: a retrospective analysis

Advanced soft-tissue sarcomas are usually resistant to cytotoxic agents such as doxorubicin and ifosfamide. Antitumor activity has been observed for gemcitabine and docetaxel combination. We conducted a retrospective study on 133 patients (58 males/75 females) with unresectable or metastatic soft-tissue sarcoma. The median age at diagnosis was 51.7 (18-82), with 76 patients with leiomoyosarcoma and 57 patients with other histological subtypes. The initial localizations were limb (44), uterine (32), retroperitoneal (23) and organs or bone (34). Patients received 900 mg/m2 of gemcitabine (days 1 and 8) over 90 min plus 100 mg/m2 of docetaxel (day 8), intravenously every 21 days. Gemcitabine/docetaxel combination was well tolerated with an overall response of 18.4% and with no clear statistical difference between leiomyosarcomas and other histological subtypes (24.2% versus 10.4% (p=0.06)). No difference was found between uterine soft-tissue sarcomas versus others. The median overall survival was 12.1 months (1-28). Better overall survival was correlated with leiomyosarcoma (p=0.01) and with the quality of the response, even for patients with stable disease (p<10(-4)). No statistical difference was found for the initial localization. Response to treatment and overall survival were better for patients in World Health Organization (WHO) performance status classification (PS) 0 at baseline versus patients in WHO PS-1, 2 or 3 (p=0.023 and p<10(-4), respectively). Gemcitabine/docetaxel combination was tolerable and demonstrated better response and survival for leiomyosarcoma, especially for patients in WHO PS-0 at baseline. For the other histological subtypes, the response was not encouraging, but the survival for patients in response or stable suggests further investigation.

[Hallux valgus: practical summary]

Hallux valgus arises from static and dynamic unbalance of the forefoot. Possibilities of conservative treatment are limited. This paper recalls the essentials of physiopathology and exposes briefly to the non-operators the most current amongst 150 operative techniques described. While becoming more complex, the surgery of hallux valgus has proven to gain efficiency. Surgical indication, based on biomechanics, should be very careful, which gives a greater interest to this discipline.