Secure app-based secondary healthcare clinical decision support to deployed forces in the UK Defence Medical Services.

BACKGROUND: Modern instant messaging systems facilitate reach-back medical support for Defence Medical Services (DMS) by connecting deployed clinicians to remote specialists. The mobile app Pando (Forward Clinical, UK) has been used for this purpose by the DMS via the 'Ask Advice' function. We aimed to investigate the usage statistics for this technology in its first 1000 days to better understand its role in the DMS. METHODS: An observational study was undertaken using metadata extracted from the prospective database within the application server for clinical queries between June 2019 and February 2022. These data included details regarding number and name of specialties, timings, active users per day and the number of conversations. RESULTS: There were 29 specialties, with 298 specialist users and 553 requests for advice. The highest volume of requests were for trauma and orthopaedics (n=116; 21.0%), ear, nose and throat (n=67; 12.1%) and dermatology (n=50; 9.0%). There was a median of 164 (IQR 82-257) users logged in per day (range 2-697). The number of requests during each day correlated with the number of users on that day (r=0.221 (95% CI 0.159 to 0.281); p<0.001). There were more daily users on weekdays than weekends (215 (IQR 123-277) vs 88 (IQR 58-121), respectively; p<0.001). For the top 10 specialties, the median first response time was 9 (IQR 3-42) min and the median time to resolution was 105 (IQR 21-1086) min. CONCLUSION: In the first 1000 days of secure app-based reach-back by the DMS there have been over 500 conversations, responded to within minutes by multiple specialists. This represents a maturing reach-back capability that may enhance the force multiplying effect of defence healthcare while minimising the deployed 'medical footprint'. Further discussions should address how this technology can be used to provide appropriately responsive clinical advice within DMS consultant job-planned time.

Acquisition and retention of military surgical competencies: a survey of surgeons' experiences in the UK Defence Medical Services.

INTRODUCTION: The acquisition and retention of militarily relevant surgical knowledge and skills are vital to enable expert management of combat casualties on operations. Opportunities for skill sustainment have reduced due to the cessation of combat operations in Iraq and Afghanistan and lack of military-relevant trauma in UK civilian practice. METHODS: A voluntary, anonymous online survey study was sent to all UK Defence Medical Services (DMS) surgical consultants and higher surgical trainees in Trauma and Orthopaedics, Plastic and Reconstructive, and General and Vascular surgical specialties (three largest surgical specialties in the DMS in terms of numbers). The online questionnaire tool included 20 questions using multiple choice and free text to assess respondents' subjective feelings of preparedness for deployment as surgeons for trauma patients. RESULTS: There were 71 of 108 (66%) responses. Sixty-four (90%) respondents were regular armed forces, and 46 (65%) worked in a Major Trauma Centre (MTC). Thirty-three (47%) had never deployed on operations in a surgical role. Nineteen (27%) felt they had sufficient exposure to penetrating trauma. When asked 'How well do you feel your training and clinical practice prepares you for a surgical deployment?' on a scale of 1-10, trainees scored significantly lower than consultants (6 (IQR 4-7) vs 8 (IQR 7-9), respectively; p<0.001). There was no significant difference in scores between regular and reservists, or between those working at an MTC versus non-MTC. Respondents suggested high-volume trauma training and overseas trauma centre fellowships, simulation, cadaveric and live-tissue training would help their preparedness. CONCLUSIONS: There was a feeling among a sample of UK DMS consultants and trainees that better preparedness is required for them to deploy confidently as a surgeon for combat casualties. The responses suggest that UK DMS surgical training requires urgent attention if current surgeons are to be ready for their role on deployed operations.

Outcomes following limb salvage after combat hindfoot injury are inferior to delayed amputation at five years.

OBJECTIVES: The surgical challenge with severe hindfoot injuries is one of technical feasibility, and whether the limb can be salvaged. There is an additional question of whether these injuries should be managed with limb salvage, or whether patients would achieve a greater quality of life with a transtibial amputation. This study aims to measure functional outcomes in military patients sustaining hindfoot fractures, and identify injury features associated with poor function. METHODS: Follow-up was attempted in all United Kingdom military casualties sustaining hindfoot fractures. All respondents underwent short-form (SF)-12 scoring; those retaining their limb also completed the American Academy of Orthopaedic Surgeons Foot and Ankle (AAOS F&A) outcomes questionnaire. A multivariate regression analysis identified injury features associated with poor functional recovery. RESULTS: In 12 years of conflict, 114 patients sustained 134 fractures. Follow-up consisted of 90 fractures (90/134, 67%), at a median of five years (interquartile range (IQR) 52 to 80 months).The median Short-Form 12 physical component score (PCS) of 62 individuals retaining their limb was 45 (IQR 36 to 53), significantly lower than the median of 51 (IQR 46 to 54) in patients who underwent delayed amputation after attempted reconstruction (p = 0.0351).Regression analysis identified three variables associated with a poor F&A score: negative Bohler's angle on initial radiograph; coexisting talus and calcaneus fracture; and tibial plafond fracture in addition to a hindfoot fracture. The presence of two out of three variables was associated with a significantly lower PCS compared with amputees (medians 29, IQR 27 to 43 vs 51, IQR 46 to 54; p < 0.0001). CONCLUSIONS: At five years, patients with reconstructed hindfoot fractures have inferior outcomes to those who have delayed amputation. It is possible to identify injuries which will go on to have particularly poor outcomes.Cite this article: P. M. Bennett, T. Stevenson, I. D. Sargeant, A. Mountain, J. G. Penn-Barwell. Outcomes following limb salvage after combat hindfoot injury are inferior to delayed amputation at five years. Bone Joint Res 2018;7:131-138. DOI: 10.1302/2046-3758.72.BJR-2017-0217.R2.

A retrospective study into the levels of evidence presented at the Combined Services Orthopaedic Society annual meeting.

OBJECTIVES: The role of Evidence Based Medicine in clinical care is to provide a framework for the integration of expertise, current evidence and the needs of the individual patient. Research presented at scientific meetings is an important source of such evidence, informing clinical decision making both on military operations and in home nation health care systems. The aim of this study is to review the levels of evidence presented at the Combined Services Orthopaedic Society (CSOS) and two other related scientific meetings. METHODS: Retrospective review of abstracts presented at the annual scientific meetings of the CSOS, Society of Military Orthopaedic Surgeons (SOMOS) and the British Trauma Society (BTS). Basic science studies, animal studies, cadaveric studies, surveys and guest lectures were excluded. Research abstracts were categorised according to the Centre for Evidence-Based Medicine's (CEBM) hierarchy of evidence. Statistical comparison was performed to investigate differences in evidence levels presented at each scientific meeting and between each year of the CSOS meeting. RESULTS: 596 abstracts met the inclusion criteria for this study (179 CSOS, 173 SOMOS, 244 BTS). Level IV evidence accounted for the majority of presented abstracts at each meeting (72.6% CSOS, 69.4% SOMOS, 68.9% BTS). Level I evidence was uncommon at each meeting (6.1% CSOS, 5.2% SOMOS, 2.9% BTS). There was no statistical difference in the evidence levels presented at the three scientific meetings. CONCLUSIONS: The proportion of comparative clinical studies (Levels I-III) presented at military or trauma societies' scientific meetings reflects the difficulty of performing research in emergency surgery. This is further exacerbated in the military environment where operational commitments and delivery of care take priority. However, the future value of comparative clinical research in battlefield healthcare could have an enduring legacy that shapes trauma care for many decades.

Improvised skeletal traction in the management of ballistic femoral fractures.

Penetrating limb injuries are common during conflict, and in many there will be an associated fracture. Treatment of ballistic femoral fractures would usually be with by intramedullary nail; however, within the resource-constrained environment during conflict this is rarely possible. This report illustrates what can be achieved at a Role 2 facility to provide skeletal traction with the equipment and skills available. We discuss the history of skeletal traction and its use in ballistic femoral fractures, and believe that skeletal traction is still a valuable technique that we shouldn't ignore. Military surgeons should be able to use skeletal traction to manage ballistic femoral fractures in the spartan environment of a deployed forward hospital.

Management of a complex hind foot war injury with negative pressure wound therapy: a case study.

We report the use of Negative Pressure Wound Therapy (NPWT) in a 39 year old patient with a complex open hind foot injury. The patient sustained an open calcaneal fracture with extensive soft tissue damage following the detonation of an explosively formed penetrating round in a confined space. A remarkable recovery was made following surgical debridement, internal fixation of the fracture and use of NPWT over the soft tissue injury. The patient returned to his normal level of function, without complications within a few months.

High-level, beta-catenin/TCF-dependent transgene expression in secondary colorectal cancer tissue.

There is an urgent need for improved therapies for inoperable metastatic colon cancer. Gene-directed enzyme prodrug therapy (GDEPT) using adenovirus vectors works well in preclinical models of this disease, but successful clinical application is hampered by an inability to construct vectors that express at high levels in infected tumor cells but not in infected normal cells. Constitutive activation of beta-catenin-dependent gene expression is almost certainly a key causative event in the genesis of colon and some other cancers. Here we have exploited this oncogenic defect to design a synthetic promoter, CTP1, that, in contrast to currently available tumor-selective promoters, is both highly active in cancer cells and highly cancer-cell-specific. CTP1 directs high-level beta-galactosidase expression in freshly isolated biopsies of secondary colon cancer, but is not detectably active in associated normal liver tissue. We also demonstrate that CTP1 can direct high-level, tumor-specific therapeutic gene expression in vivo. Intratumoral injection of an adenovirus vector encoding Escherichia coli nitroreductase driven by CTP1 efficiently sensitized SW480 xenografts to the prodrug CB1954, whereas systemic vector and prodrug administration produced no apparent signs of toxicity. CTP1 may form the basis for effective, targeted gene therapy of metastatic colon cancer and other tumors with deregulated beta-catenin/T cell factor.

Targeting properties of an anti-CD16/anti-CD30 bispecific antibody in an in vivo system.

Bispecific antibodies are currently being used in clinical trials in increasing numbers in the areas of breast cancer, prostate cancer, non-Hodgkin's lymphoma and Hodgkin's lymphoma. We have previously performed two clinical trials in patients with Hodgkin's disease with an anti-CD30/anti-CD16 bispecific antibody and demonstrated a 30% response rate in a cohort of patients otherwise resistant to standard therapeutic modalities. However, no surrogate marker could be defined in these trials indicative of optimal antibody dosing/scheduling or predictive for favorable response. In order to evaluate accurately the potential biodistribution properties of bispecific antibody in patients, we have performed a detailed analysis of the binding properties and animal model in vivo characteristics of these constructs. For this purpose, the parental antibodies (anti-CD30 and anti-CD16) and the bispecific antibody (anti-CD30/anti-CD16) were radiolabeled with either 125I or 111In. Antibody integrity and binding properties after labeling were confirmed by Scatchard plot and Lindmo analysis. 111In-labeled antibodies revealed superior targeting properties in a standard SCID mouse tumor model. Both the bivalent parental anti-CD30 monoclonal antibody and the monovalent anti-CD30/anti-CD16 bispecific antibody showed excellent uptake in CD30+ tumors which did not differ significantly between the two (maximum uptake 16.5%+/-4.2% vs. 18.4%+/-3.8% injected dose/gram tissue). The equivalent targeting properties of the bispecific antibody compared with the parental anti-CD30 antibody encourages the further clinical development of this bispecific antibody, and might help to explain the clinical responses seen with this antibody so far in patients suffering from Hodgkin's disease.

CL22 - a novel cationic peptide for efficient transfection of mammalian cells.

Condensing peptide-DNA complexes have great potential as nonviral agents for gene delivery. To date, however, such complexes have given transfection activities greatly inferior to adenovirus and somewhat inferior to cationic lipid-DNA complexes, even for cell lines and primary cells in vitro. We report here the identification of a novel condensing peptide, CL22, which forms DNA complexes that efficiently transfect many cell lines, as well as primary dendritic and endothelial cells. We report studies with sequence and structure variants that define some properties of the peptide that contribute to efficient transfection. We demonstrate that the superior transfection activity of CL22 compared with other DNA condensing peptides is conferred at a step after uptake of the complexes into cells. We show that CL22-DNA complexes have transfection activity that is at least equivalent to the best available nonviral agents.

Tumour-specific therapeutic adenovirus vectors: repression of transgene expression in healthy cells by endogenous p53.

Approximately 50% of human tumours lack functional p53 suppressor protein. A promoter that is repressed by p53 in healthy cells could thus provide tumour-specific gene expression for a huge subset of tumours. In this report we describe a double recombinant adenovirus vector, 'Ad.p53R', encoding a therapeutic gene that is indirectly repressed by endogenous wild-type p53. Ad.p53R contains two independent expression cassettes; (1) the E. coli nitroreductase gene (NTR) driven by the human hsp70 promoter containing LacI binding sites (hsp70lacO-NTR) and (2) a p53-inducible lac repressor gene (tkGC3-lacI). In p53 null cells (Hep3B), Ad.p53R directed the same level of NTR expression as Ad.p53NR which lacks the tkGC3-lacI cassette. Moreover, injection of SW480 xenografts (mutated p53) with Ad.p53R resulted in a clear inhibition of growth in response to the prodrug CB1954. In cells retaining wt p53 (HepG2 and primary human endothelial cells), Ad.p53R expressed significantly less NTR (approximately 70%) than Ad.p53NR. Ad.p53R administered by i.v. injection also produced significantly less NTR than Ad.p53NR in normal tissues in vivo. Finally, adenovirus infection per se of cultured HepG2 cells at low MOI induced p53 stabilisation suggesting that adenovirus-mediated gene delivery may contribute to p53-based selectivity.

Combined adenovirus-mediated nitroreductase gene delivery and CB1954 treatment: a well-tolerated therapy for established solid tumors.

Gene-directed enzyme prodrug therapy (GDEPT) is a refinement of cancer chemotherapy that generates a potent cell-killing drug specifically in tumor cells by enzymatic activation of an inert prodrug. We describe in vivo studies that evaluate the efficacy and safety of intratumoral (i.t.) injection of an adenovirus vector (CTL102) expressing Escherichia coli nitroreductase (NTR) combined with systemic prodrug (CB1954) treatment. A single i.t. injection of CTL102 (7.5 x 10(9) to -2 x 10(10) particles) followed by CB1954 treatment produced clear anti-tumor effects in subcutaneous (s.c.) xenograft models of four cancers that are likely candidates for GDEPT (i.e., primary liver, head and neck, colorectal and prostate). Virus dose-response studies (s.c. liver model) revealed a steep increase and subsequent rapid plateauing of both NTR gene delivery and anti-tumor efficacy. Evidence of minor virus spread (toxicity) was observed in a s.c. head and neck xenograft model. This was eliminated by passive immunization with neutralizing anti-Ad5 antibodies prior to virus injection without reducing the magnitude of the anti-tumor effect. Preexisting anti-Ad5 neutralizing antibodies may therefore be an advantage rather than an issue in the clinical use of this new therapy.

Efficient nonviral transfection of dendritic cells and their use for in vivo immunization.

Immunization with dendritic cells (DCs) transfected with genes encoding tumor-associated antigens (TAAs) is a highly promising approach to cancer immunotherapy. We have developed a system, using complexes of plasmid DNA expression constructs with the cationic peptide CL22, that transfects human monocyte-derived DCs much more efficiently than alternative nonviral agents. After CL22 transfection, DCs expressing antigens stimulated autologous T cells in vitro and elicited primary immune responses in syngeneic mice, in an antigen-specific manner. Injection of CL22-transfected DCs expressing a TAA, but not DCs pulsed with a TAA-derived peptide, protected mice from lethal challenge with tumor cells in an aggressive model of melanoma. The CL22 system is a fast and efficient alternative to viral vectors for engineering DCs for use in immunotherapy and research.

Expression of Escherichia coli B nitroreductase in established human tumor xenografts in mice results in potent antitumoral and bystander effects upon systemic administration of the prodrug CB1954.

Expression of the Escherichia coli enzyme nitroreductase (NTR) in mammalian cells enables them to activate the prodrug 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954), leading to interstrand DNA cross-linking and apoptosis in both proliferating and quiescent cells. In the work reported here, we used human hepatocellular carcinoma and squamous carcinoma cell lines constitutively expressing NTR to demonstrate that the ntr/CB1954 system results in potent, long-lasting antitumoral effects in mice. We also demonstrate that this enzyme/prodrug combination results in antitumoral effects in vivo when only a minority of tumor cells express the enzyme, using either cells constitutively expressing NTR or ntr gene delivery in situ.

Sensitisation of human carcinoma cells to the prodrug CB1954 by adenovirus vector-mediated expression of E. coli nitroreductase.

The enzyme nitroreductase from E. coli can reduce the weak, monofunctional alkylating agent 5-(aziridin-1-yl)-2, 4-dinitrobenzamide (CB1954) to a potent cytotoxic species that generates interstrand crosslinks in DNA. Nitroreductase therefore has potential as a "suicide enzyme" for cancer gene therapy, as cells that express nitroreductase become selectively sensitive to the prodrug CB1954. We have incorporated a nitroreductase expression cassette into a replication-defective adenovirus vector (Ad-CMV-ntr), which allowed efficient gene transfer to SK-OV-3 or IGROV-1 ovarian carcinoma cells. Nitroreductase levels increased in line with multiplicity of infection, and this was reflected in increasing sensitisation of the cells to CB1954, reaching an optimum (approx. 2, 000-fold sensitisation) with 25-50 p.f.u. per cell. Similar Ad-CMV-ntr-dependent sensitisation to CB1954 was seen in 3 of 6 low-passage primary ovarian tumour lines. Cells grown at low-serum concentration to inhibit proliferation remained equally susceptible to the Ad-CMV-ntr-dependent cytotoxicity of CB1954, indicating a distinct advantage over retroviral gene delivery and other popular enzyme-prodrug systems for human tumours with a low rate of cell proliferation. Additionally, cisplatin-resistant cells were sensitised towards CB1954 by Ad-CMV-ntr as efficiently as the parental cells, indicating that the system could be effective in patients with cisplatin-resistant tumours. In a murine xenograft model for disseminated peritoneal carcinomatosis with ascites, treatment of nude mice bearing intraperitoneal SUIT2 tumours with Ad-CMV-ntr and CB1954 almost doubled the median survival from 14 to 26 days (p < 0.0001).

Gene therapy: the first decade.

Gene therapy promises to revolutionize medicine by treating the causes of disease rather than the symptoms. We are nearing the end of the first decade of gene therapy, and this article summarizes the approaches taken, results achieved, lessons learned and important recent developments. The early results on the clinical efficacy of gene therapies were disappointing, largely because the available gene-transfer vectors proved to be inadequate. Recently, however, clinical benefit has been clearly demonstrated and great progress made in selecting and improving vectors. There is now every prospect that the second decade will see gene therapy live up to its enormous potential.

VL:VH domain rotations in engineered antibodies: crystal structures of the Fab fragments from two murine antitumor antibodies and their engineered human constructs.

The crystal structures of two pairs of Fab fragments have been determined. The pairs comprise both a murine and an engineered human form, each derived from the antitumor antibodies A5B7 and CTM01. Although antigen specificity is maintained within the pairs, antigen affinity varies. A comparison of the hypervariable loops for each pair of antibodies shows their structure has been well maintained in grafting, supporting the canonical loop model. Detailed structural analysis of the binding sites and domain arrangements for these antibodies suggests the differences in antigen affinity observed are likely to be due to inherent flexibility of the hypervariable loops and movements at the VL:VH domain interface. The four structures provide the first opportunity to study in detail the effects of protein engineering on specific antibodies.

Conversion of highly malignant colon cancer from an aggressive to a controlled disease by oral administration of a metalloproteinase inhibitor.

In this study, we describe the activity of CT1746, an orally-active synthetic MMP inhibitor that has a greater specificity for gelatinase A, gelatinase B and stromelysin than for interstitial collagenase and matrilysin, in a nude mouse model that better mimics the clinical development of human colon cancer. The model is constructed by surgical orthotopic implantation (SOI) of histologically-intact tissue of the metastatic human colon tumor cell line Co-3. Animals were gavaged with CT1746 twice a day at 100 mg/kg for 5 days after the SOI of Co-3 for 43 days. In this model CT1746 significantly prolonged the median survival time of the tumor-bearing animals from 51 to 78 days. Significant efficacy of CT1746 was observed on primary tumor growth (32% reduction in mean tumor area at day 36), total spread and metastasis (6/20 treated animals had no detectable spread and metastasis at autopsy compared to 100% incidence of secondaries in control groups). Efficacy of CT1746 could also be seen on reducing tumor spread and metastasis to individual organ sites such as the abdominal wall, cecum and lymph nodes compared to vehicle and untreated controls. We conclude that chronic administration of a peptidomimetic MMP inhibitor via the oral route is feasible and results in inhibition of solid tumor growth, spread and metastasis with increase in survival in this model of human cancer, thus converting aggressive cancer to a more controlled indolent disease.