Neutrophil Conversion to a Tumor-Killing Phenotype Underpins Effective Microbial Therapy.

The inflammatory microenvironment of solid tumors creates a protumorigenic milieu that resembles chronic inflammation akin to a subverted wound healing response. Here, we investigated the effect of converting the tumor microenvironment from a chronically inflamed state to one of acute microbial inflammation by injecting microbial bioparticles directly into tumors. Intratumoral microbial bioparticle injection led to rapid and dramatic changes in the tumor immune composition, the most striking of which was a substantial increase in the presence of activated neutrophils. In situ photoconversion and intravital microscopy indicated that tumor neutrophils transiently switched from sessile producers of VEGF to highly motile neutrophils that clustered to make neutrophil-rich domains in the tumor. The neutrophil clusters remodeled tumor tissue and repressed tumor growth. Single-cell transcriptional analysis of microbe-stimulated neutrophils showed a profound shift in gene expression towards heightened activation and antimicrobial effector function. Microbe-activated neutrophils also upregulated chemokines known to regulate neutrophil and CD8+ T-cell recruitment. Microbial therapy also boosted CD8+ T-cell function and enhanced the therapeutic benefit of checkpoint inhibitor therapy in tumor-bearing mice and provided protection in a model of tumor recurrence. These data indicate that one of the major effector mechanisms of microbial therapy is the conversion of tumor neutrophils from a wound healing to an acutely activated cytotoxic phenotype, highlighting a rationale for broader deployment of microbial therapy in the treatment of solid cancers. SIGNIFICANCE: Intratumoral injection of microbial bioparticles stimulates neutrophil antitumor functions, suggesting pathways for optimizing efficacy of microbial therapies and paving the way for their broader utilization in the clinic.

The Prognostic Value of Posttreatment 68Ga-PSMA-11 PET/CT and 18F-FDG PET/CT in Metastatic Castration-Resistant Prostate Cancer Treated with 177Lu-PSMA-617 and NOX66 in a Phase I/II Trial (LuPIN).

177Lu-PSMA-617 therapy has shown high prostate-specific antigen (PSA) response rates in men with metastatic castration-resistant prostate cancer. However, early treatment resistance is common. This LuPIN substudy aimed to determine the prognostic value of posttreatment quantitative PET for PSA progression-free survival (PFS) and overall survival (OS) with 177Lu-PSMA-617 therapy. Methods: Fifty-six men with progressive metastatic castration-resistant prostate cancer were enrolled in the LuPIN trial and received up to 6 doses of 177Lu-PSMA-617 and a radiation sensitizer (NOX66). 68Ga-PSMA-11 and 18F-FDG PET/CT, diagnostic CT, and bone scanning were performed at study entry and exit. Quantitative analysis tracked change in total tumor volume (TTV) and SUV. Univariable and multivariable analyses were conducted to examine the association of change in TTV (continuous and >30%), SUVmax, PSA, and radiographic progression with PSA PFS and OS. Results: All men (37/56) who underwent both screening and posttreatment molecular imaging were analyzed; 70% (26/37) had a PSA response of more than 50%. Median PSA PFS was 8.6 mo, and median OS was 22 mo. Clinical progression had occurred at trial exit in 54% (20/37). In response to treatment, a reduced PSMA SUVmax was demonstrated in 95% (35/37) and a reduced PSMA TTV in 68% (25/37). An increase in PSMA TTV by at least 30% was associated with worse OS (median, 10.2 vs. 23.6 mo; P = 0.002). Change in PSMA SUVmax was not associated with PSA PFS or OS. 18F-FDG SUVmax was reduced in 51% (18/35) and 18F-FDG TTV in 67% (22/35). An increased 18F-FDG SUVmax was associated with worse OS (median, 20.7 vs. 25.7 mo; P < 0.01). An 18F-FDG TTV increase by more than 30% was associated with a short PSA PFS (median, 3.5 vs. 8.6 mo; P < 0.001) but not OS. Both PSA and radiographic progression were associated with shorter OS (median, 14.5 vs. 25.7 mo [P < 0.001] and 12.2 vs. 23.6 mo [P = 0.002]). On multivariable analysis, only increased PSMA TTV and PSA progression remained independently prognostic of OS (hazard ratio, 5.1 [95% CI, 1.5-17.1; P = 0.008] and 3.5 [95% CI, 1.1-10.9; P = 0.03], respectively). Conclusion: Change in quantitative PSMA TTV has strong potential as a prognostic biomarker with 177Lu-PSMA-617 therapy, independent of 18F-FDG PET parameters, PSA, or radiographic progression. Further research into the value of posttreatment PET as an imaging biomarker is warranted.

177Lu-PSMA SPECT Quantitation at 6 Weeks (Dose 2) Predicts Short Progression-Free Survival for Patients Undergoing 177Lu-PSMA-I&T Therapy.

177Lu-PSMA is an effective treatment in metastatic castration-resistant prostate cancer (mCRPC). Our ability to assess response rates and adjust treatment may be improved using predictive tools. This study aimed to evaluate change in 177Lu-PSMA SPECT quantitative parameters to monitor treatment response. Methods: One hundred twenty-seven men with progressive mCRPC previously treated with androgen-signaling inhibition (99%) and chemotherapy (71%) received a median of 3 (interquartile range [IQR], 2-5) 8-GBq (IQR, 8-8.5 GBq) doses of 177Lu-PSMA-I&T. Imaging included 68Ga-PSMA-11 PET/CT (SUVmax > 15 at a single site and > 10 at all sites > 2 cm), diagnostic CT, and 177Lu SPECT/CT from vertex to mid thigh (24 h after treatment). 177Lu SPECT/CT quantitative analysis was undertaken at cycles 1 (baseline) and 2 (week 6) of treatment. Clinical and biochemical results were assessed to evaluate prostate-specific antigen (PSA) progression-free survival (PFS) and overall survival (OS). Results: A PSA reduction of more than 50% was seen in 58% (74/127). The median PSA PFS was 6.1 mo (95% CI, 5.5-6.7), and OS was 16.8 mo (95% CI, 13.5-20.1). At the time of analysis, 41% (52/127) were deceased. At baseline and week 6, 76% (96/127) had analyzable serial 177Lu SPECT/CT imaging. SPECT total tumor volume (TTV) was reduced between baseline and week 6 in 74% (71/96; median, -193; IQR, -486 to -41). Any increase in SPECT TTV between baseline and week 6 was associated with significantly shorter PSA PFS (hazard ratio, 2.5; 95% CI, 1.5-4.2; P = 0.0008) but not OS. Median PSA PFS in those with an increase in SPECT TTV was 3.7 mo (95% CI, 2.8-6.8), compared with 6.7 mo (95% CI, 5.8-10.6) in those with no increase in SPECT TTV. An increase in SPECT TTV greater than 20% was also associated with PSA PFS (hazard ratio, 1.9; 95% CI, 1.2-3.0; P = 0.008) but less significantly than any change in SPECT TTV. There was a significant difference in PSA PFS between patients with both increased PSA and SPECT TTV and patients with reduced SPECT TTV and PSA (median, 2.8 vs. 9.0 mo; P < 0.0001). Conclusion: Increasing PSMA SPECT TTV on quantitative 177Lu SPECT/CT predicts short progression-free survival and may play a future role as an imaging response biomarker, identifying when to cease or intensify 177Lu-PSMA therapy.

Evaluation of 177Lu-PSMA-617 SPECT/CT Quantitation as a Response Biomarker Within a Prospective 177Lu-PSMA-617 and NOX66 Combination Trial (LuPIN).

177Lu-PSMA-617 is an effective and novel treatment in metastatic castration-resistant prostate cancer (mCRPC). Our ability to assess response rates and therefore efficacy may be improved using predictive tools. This study investigated the predictive value of serial 177Lu-PSMA-617 SPECT/CT (177Lu SPECT) imaging in monitoring treatment response. Methods: Fifty-six men with progressive mCRPC previously treated with chemotherapy and novel androgen signaling inhibitor were enrolled into the LuPIN trial and received up to 6 doses of 177Lu-PSMA-617 and a radiation sensitizer (3-(4-hydroxyphenyl)-2H-1-benzopyran-7-ol [NOX66]). 68Ga-PSMA-11 and 18F-FDG PET/CT were performed at study entry and exit, and 177Lu SPECT from vertex to mid thighs was performed 24 h after each treatment. SPECT quantitative analysis was undertaken at cycles 1 (baseline) and 3 (week 12) of treatment. Results: Thirty-two of the 56 men had analyzable serial 177Lu SPECT imaging at both cycle 1 and cycle 3. In this subgroup, median prostate-specific antigen (PSA) progression-free survival (PFS) was 6.3 mo (95% CI, 5-10 mo) and median overall survival was 12.3 mo (95% CI, 12-24 mo). The PSA 50% response rate was 63% (20/32). 177Lu SPECT total tumor volume (SPECT TTV) was reduced in 68% (22/32; median, -0.20 m3 [95% CI, -1.4 to -0.001]) and increased in 31% (10/32; median, 0.36 [95% CI, 0.1-1.4]). Any increase in SPECT TTV was associated with shorter PSA PFS (hazard ratio, 4.1 [95% CI, 1.5-11.2]; P = 0.006). An increase of 30% or more in SPECT TTV was also associated with a shorter PSA PFS (hazard ratio, 3.3 [95% CI, 1.3-8.6]; P =0.02). Tumoral SUVmax was reduced in 91% (29/32) and SUVmean in 84% (27/32); neither was associated with PSA PFS or overall survival outcomes. PSA progression by week 12 was also associated with a shorter PSA PFS (hazard ratio, 26.5 [95% CI, 5.4-131]). In the patients with SPECT TTV progression at week 12, 50% (5/10) had no concurrent PSA progression (median PSA PFS, 4.5 mo [95% CI, 2.8-5.6 mo]), and 5 of 10 men had both PSA and SPECT TTV progression at week 12 (median PSA PFS, 2.8 mo [95% CI, 1.8-3.7 mo]). Conclusion: Increasing SPECT TTV on quantitative 177Lu SPECT predicts a short PFS and may play a future role as an imaging response biomarker.

177Lu-PSMA-617 and Idronoxil in Men with End-Stage Metastatic Castration-Resistant Prostate Cancer (LuPIN): Patient Outcomes and Predictors of Treatment Response in a Phase I/II Trial.

177Lu-PSMA-617 is an effective therapy for metastatic castration-resistant prostate cancer (mCRPC). However, treatment resistance occurs frequently, and combination therapies may improve outcomes. We report the final safety and efficacy results of a phase I/II study combining 177Lu-PSMA-617 with idronoxil (NOX66), a radiosensitizer, and examine potential clinical, blood-based, and imaging biomarkers. Methods: Fifty-six men with progressive mCRPC previously treated with taxane chemotherapy and novel androgen signaling inhibitor (ASI) were enrolled. Patients received up to 6 doses of 177Lu-PSMA-617 (7.5 GBq) on day 1 in combination with a NOX66 suppository on days 1-10 of each 6-wk cycle. Cohort 1 (n = 8) received 400 mg of NOX66, cohort 2 (n = 24) received 800 mg, and cohort 3 (n = 24) received 1,200 mg. 68Ga-PSMA and 18F-FDG PET/CT were performed at study entry, and semiquantitative imaging analysis was undertaken. Blood samples were collected for analysis of blood-based biomarkers, including androgen receptor splice variant 7 expression. The primary outcomes were safety and tolerability; secondary outcomes included efficacy, pain scores, and xerostomia. Regression analyses were performed to explore the prognostic value of baseline clinical, blood-based, and imaging parameters. Results: Fifty-six of the 100 men screened were enrolled (56%), with a screening failure rate of 26% (26/100) for PET imaging criteria. All men had received prior treatment with ASI and docetaxel, and 95% (53/56) had received cabazitaxel. Ninety-six percent (54/56) of patients received at least 2 cycles of combination NOX66 and 177Lu-PSMA-617, and 46% (26/56) completed 6 cycles. Common adverse events were anemia, fatigue, and xerostomia. Anal irritation attributable to NOX66 occurred in 38%. Forty-eight of 56 had a reduction in prostate-specific antigen (PSA) level (86%; 95% CI, 74%-94%); 34 of 56 (61%; 95% CI, 47%-74%) had a PSA reduction of at least 50%. Median PSA progression-free survival was 7.5 mo (95% CI, 5.9-9 mo), and median overall survival was 19.7 mo (95% CI, 9.5-30 mo). A higher PSMA SUVmean correlated with treatment response, whereas a higher PSMA tumor volume and prior treatment with ASI for less than 12 mo were associated with worse overall survival. Conclusion: NOX66 with 177Lu-PSMA-617 is a safe and feasible strategy in men being treated with third-line therapy and beyond for mCRPC. PSMA SUVmean, PSMA-avid tumor volume, and duration of treatment with ASI were independently associated with outcome.

Phase I/II Trial of the Combination of 177Lutetium Prostate specific Membrane Antigen 617 and Idronoxil (NOX66) in Men with End-stage Metastatic Castration-resistant Prostate Cancer (LuPIN).

BACKGROUND: Trials of lutetium prostate specific membrane antigen (PSMA) in men with metastatic castration-resistant prostate cancer (mCRPC) have demonstrated good safety and efficacy, but combination strategies may improve outcomes. Idronoxil is a synthetic flavonoid derivative with radiosensitising properties. OBJECTIVE: To evaluate the safety and activity of 177Lu PSMA 617 (LuPSMA-617) in combination with idronoxil suppositories (NOX66) in patients with end-stage mCRPC. DESIGN, SETTING, AND PARTICIPANTS: Thirty-two men with progressive mCRPC previously treated with taxane-based chemotherapy (91% treated with both docetaxel and cabazitaxel) and abiraterone and/or enzalutamide were enrolled in this phase I dose escalation study with phase II dose expansion. INTERVENTION: Screening with 68Ga PSMA and 18F-fludeoxyglucose positron emission tomography (PET)/computed tomography (CT) was performed. Men received up to six cycles of LuPSMA-617 (7.5 GBq) on day 1, with escalating doses of NOX66 on days 1-10 of a 6-wk cycle. Cohort 1 (n = 8) received 400 mg and cohort 2 (n = 24) 800 mg of NOX66. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Adverse events (AEs), pain inventory scores, prostate-specific antigen (PSA) response, progression-free survival, and overall survival were evaluated. RESULTS AND LIMITATIONS: Fifty-six men were screened and 32 (57%) were enrolled with a screen failure rate of 21% for PET imaging criteria. Dosing was as follows: 97% (31/32) received two or more doses and 47% (15/32) completed six doses. Common AEs included xerostomia, fatigue, and anaemia. Anal irritation attributable to NOX66 occurred in 28%. PSA responses were as follows: 91% (29/32) had any PSA response (median -74%; 95% confidence interval [CI] 76-97) and 62.5% (20/32) had a PSA fall of >50% (95% CI 45-77). The median PSA progression-free survival was 6.1 mo (95% CI 2.8-9.2) and median overall survival was 17.1 mo (95% CI 6.5-27.1). CONCLUSIONS: NOX66 with LuPSMA-617 is a safe and feasible therapeutic strategy in men treated with third-line therapy and beyond for mCRPC. PATIENT SUMMARY: Addition of NOX66 to 177Lu prostate-specific membrane antigen 617 is safe, and further studies are needed to assess its potential to augment the anticancer effects of LuPSMA-617.

Imaging the neutrophil: Intravital microscopy provides a dynamic view of neutrophil functions in host immunity.

Neutrophils are the first cellular responders of the immune system. They employ their impressive arsenal of microbicidal molecules to provide rapid and efficient defense against pathogens. However, the role of neutrophils extends far beyond microbial destruction to include tissue repair and remodeling, provision of signals to the adaptive immune system and body homeostasis. Intravital imaging has allowed the visualization of neutrophils in their native environment in both health and disease and provided crucial insights into their mechanisms of action. In the last few years the power of intravital imaging has been considerably extended by the introduction of photoconvertible proteins and intracellular signaling reporter mice. This review will highlight recent advances in our understanding of neutrophil biology based on the use of intravital microscopy to visualize their modus operandi in vivo including migration in and out of inflamed tissues, host-pathogen interactions and cell fate.

The Ins and Outs of Chemokine-Mediated Immune Cell Trafficking in Skin Cancer.

Recent studies of the patterns of chemokine-mediated immune cell recruitment into solid tumors have enhanced our understanding of the role played by various immune cell subsets both in amplifying and inhibiting tumor cell growth and spread. Here we discuss how the chemokine/chemokine receptor networks bring together immune cells within the microenvironment of skin tumors, particularly melanomas, including their effect on disease progression, prognosis and therapeutic options.

A Biomechanical Comparison of Different Knots Tied on Fibrewire Suture.

BACKGROUND: Synthetic sutures such as Fiberwire used in flexor tendon repairs have high tensile strength. Proper application allows early mobilisation, decreasing morbidity from repair rupture and adhesions while preserving range of motion. Suture stiffness can cause poorer knot holding, contributing to gapping, peritendinous adhesions or rupture. Previous studies recommended more throws in knots tied on Fiberwire to prevent knot slippage. These larger knots are voluminous and prominent. In tendon repairs they can cause "catching", increase friction and work of flexion. Other studies advocated certain complicated knots as being more secure. We evaluated several knots and their biomechanical properties with the aim of finding a compact knot with less potential for slippage to maximise strength potential of flexor tendon repairs using Fiberwire. METHODS: A series of different knots tied on Fiberwire 4-0 sutures were pulled to failure on a mechanical tester. Mean tensile strengths, knot volumes and tensile strength to knot volume ratios were compared. RESULTS: Tensile strengths and knot volume increased with more throws and loops. Four variations of the square knot (the 4=4=1, 2=2=2=2, 1=1=1=1=1, 2=1=1=1=1 knots) had tensile strengths greater than 35N. The specialised anti-slip knot had highest tensile strength and suture volume but lower strength-to-volume ratio. CONCLUSIONS: The anti-slip knot had highest tensile strength but it also had the highest volume. The greater strength of repair may not translate into improved clinical outcome. The 1=1=1=1=1 knot has superior knot strength-to-volume ratio with good knot strength adequate for early active mobilisation in flexor tendon repairs.

A biomechanical comparison of 3 loop suture materials in a 6-strand flexor tendon repair technique.

PURPOSE: The braided polyblend (FiberWire) suture is recognized for its superiority in tensile strength in flexor tendon repair. The purpose of this study was to compare the biomechanical performance of 3 loop-suture materials used in a locking 6-strand flexor tendon repair configuration: braided polyblend (FiberLoop 4-0), cable nylon (Supramid Extra II 4-0), and braided polyester (Tendo-Loop 4-0). We hypothesized that, using this technique, the braided polyblend suture would give superior tensile strength compared with the other 2 suture materials. METHODS: We divided 30 fresh porcine flexor tendons transversely and repaired each with 1 of the 3 suture materials using a modified Lim-Tsai 6-strand suture technique. We loaded the repaired tendons to failure using a materials testing machine and collected data on the mechanism of failure, ultimate tensile strength, gap strength, and stiffness. RESULTS: Failure mechanisms for the repaired specimens were as follows: the braided polyblend had 50% suture breakage and 50% suture pullout; the cable nylon had 100% suture breakage; and the braided polyester had 80% suture breakage and 20% suture pullout. Specimens repaired with the braided polyblend suture had the highest mean ultimate tensile strength (97 N; standard deviation, 22) and the highest mean gap force (35 N; standard deviation, 7). CONCLUSIONS: This study supports the findings of previous studies showing superior strength of the braided polyblend suture. CLINICAL RELEVANCE: We were able to achieve up to 124 N in ultimate tensile strength and 48 N of gap force with this suture in porcine tendons. This gives greater confidence in starting immediate controlled passive or active rehabilitation after repair of flexor tendon injuries.

The hook plate technique for fixation of phalangeal avulsion fractures.

BACKGROUND: Avulsion fractures of the phalanges involve small osseous fragments that are usually attached to structures that are necessary for stability or movement of the joint. Satisfactory healing of the fracture to preserve joint function may require open reduction and internal fixation, which can be difficult because of the small size of the fragments. METHODS: We used a hook plate fashioned from a 1.3-mm Synthes titanium plate in thirteen patients with a phalangeal avulsion fracture. Four patients had an avulsion fracture of the volar plate with dorsal proximal interphalangeal joint dislocation, four had a dorsal avulsion fracture of the extensor central slip from the middle phalanx, three had a flexor digitorum profundus avulsion fracture from the distal phalanx, and two had an avulsion fracture of the phalangeal insertion of the collateral ligament. RESULTS: Union without complications was achieved in all cases. After an average duration of follow-up of seventeen months, all patients had a good to excellent result and the average total interphalangeal motion was 149°. CONCLUSIONS: This indirect fixation technique produces stable fixation allowing early active finger motion.

Radial nerve injury during double plating of a displaced intercondylar fracture.

Double-plate fixation is a popular treatment method for intercondylar humeral fractures. Ulnar nerve complications are emphasized, but radial nerve complications are rarely mentioned. We present a case of iatrogenic radial nerve palsy following open reduction and double plating of a supracondylar/intercondylar fracture of the humerus. Before surgery, only a sensory deficit in the radial nerve territory was present, but after surgery, there was a complete motor deficit of the wrist and finger extensors. On exploration, a segment of nerve was found crushed within the reduced lateral condyle fracture site, with a screw from the posteroradial plate going through the nerve. Although rare, radial nerve injury can occur with posteriorly displaced supracondylar/intercondylar humerus fractures. When preoperative signs of radial nerve injury are present, we recommend that the radial nerve be identified and protected during double-plate fixation.

Technique of olecranon bone grafting for surgical fixation of scaphoid fractures.

Currently described sources of bone graft, such as iliac crest and distal radius, for supplemental fixation of scaphoid fractures are suboptimal. In our experience, olecranon bone has the advantage of providing a convenient source of corticocancellous block graft that can be harvested within the same sterile operative field used for fixation of the scaphoid fracture, and it also causes less postoperative pain compared to that obtained from iliac crest. Here, we describe our surgical technique for harvest and use of olecranon bone graft for fixation of scaphoid fractures.

Spontaneous partial posterior interosseous nerve palsy not caused by an adjacent ganglion.

We report a case of spontaneous partial posterior interosseous nerve palsy where the ganglion adjacent to the nerve was not the main cause of the compression. Instead, a thick fascial band deep to the distal edge of the supinator was found responsible. This case illustrates the importance of completing the nerve exploration to fit with the clinical picture.

Epidemiology and management of surgical upper limb infections in patients with end-stage renal failure.

INTRODUCTION: Hand infections in patients with end-stage renal failure (ESRF) are more diffi cult to treat and have had the worse outcomes. This paper examines the epidemiology, bacteriology and outcomes of surgically managed upper limb infections in these vulnerable patients. MATERIALS AND METHODS: All patients from a single centre with surgically-managed upper limb infections between 2001 and 2007 were reviewed. We collected epidemiological data on demographics, type and site of infection, bacteriology, surgical treatment, complications and mortality. RESULTS: Forty-seven out of 803 (6%) patients with surgically managed upper limb infections in the study period had ESRF. The average age was 59 years. ESRF was secondary to diabetes in 88% of cases. Patients presented on average 7 days after onset of symptoms. Abscesses (34%), wet gangrene (26%) and osteomyelitis (11%) were the commonest infections. Methicillin-resistant Staphylococcus aureus (MRSA) was the commonest pathogen (29%), occurring either in isolation or with other organisms. Eighteen percent of single organisms cultured were gram-negative. Multiple organisms occurred in 29%. A median of 2 operations were required. Thirty-six percent of all cases required amputation. Twenty-fi ve percent of patients had a life-threatening event (myocardial infarction or septic shock) during treatment. CONCLUSIONS: ESRF patients present late with severe upper limb infections. Nosocomial infections are common. Initial empirical antibiotic treatment should cover MRSA and gram-negative bacteria. Immediate referral to a hand surgery unit is recommended. Multi-disciplinary management of the patient with input from physicians and anaesthetists or intensivists in the perioperative period is necessary to optimise the patient for surgery and to manage active medical comorbidities and complications after surgery.

Mycobacterium abscessus Hand Infections in Immunocompetent Fish Handlers: Case Report.

Mycobacterium abscessus hand infections are rare and usually occur in immunocompromised patients or after injection with contaminated injectables. This article describes 2 cases of M abscessus infection of the hand in otherwise healthy fish handlers. Mycobacterium abscessus can cause severe chronic tenosynovitis even in immunocompetent patients and should be suspected alongside the more common M marinum as a cause of nontuberculous mycobacterial hand infections in patients with aquatic and fish exposure.