Wound healing of experimental equine skin wounds and concurrent microbiota in wound dressings following topical propylene glycol gel treatment.

Introduction: Topical wound treatments rely on carrier formulations with little to no biological impact. The potential for a common vehicle, a propylene glycol (PG) gel, to affect wound healing measures including microbiota is not known. Microbiome characterization, based on next generation sequencing methods is typically performed on tissue or directly obtained wound fluid samples. The utility for primary wound dressings to characterize equine wound microbiota in the context of topical treatments is currently unknown. This investigation reports the topical effect of an 80% PG based gel on wound healing and microbiota in wound dressings. Methods: Experiments were performed in six mature horses utilizing a surgical, distal limb wound model, histology of sequential wound biopsies, photographic wound measurements and microbiota profiling via 16s rRNA sequencing of wound dressing samples. Experimental wounds were surveyed for 42 days and either treated (Day 7, 14, 21 and 28; at 0.03 ml/cm2) or unexposed to the PG gel. Wound surface area, relative and absolute microbial abundances, diversity indices and histologic parameters were analyzed in the context of the experimental group (treatment; control) using qualitative or quantitative methods depending on data characteristics. Results: Compared to controls, treatment slowed the wound healing rate (17.17 ± 4.27 vs. 18.56 ± 6.3 mm2/day), delayed the temporal decline of polymorphonucleated cells in wound beds and operational taxonomic units (OTU) in wound dressings and lowered alpha-diversity indices for microbiota in primary wound dressing. Relative abundances of OTUs were in line with those previously reported for equine wounds. Clinical outcomes 42 days post wounding were considered similar irrespective of PG gel exposure. Discussion: Results highlight the potential for vehicle exposure to alter relevant wound outcome measures, imposing the need for stringent experimental control measures. Primary wound dressings may represent an alternate sample source for characterization of the wound microbiome alleviating the need for additional interventions. Further studies are warranted to contrast the microbiome in wound dressings against that present on wound surfaces to conclude on the validity of this approach.

Predictive value of serial evaluation of the Sequential Organ Failure Assessment (SOFA) score for intensive care unit mortality in critically ill patients with COVID-19: a retrospective cohort study.

BACKGROUND: The Sequential Organ Failure Assessment (SOFA) score has been developed to score the severity of organ dysfunction in critically ill sepsis patients and has been proven to have a high predictive value for intensive care unit (ICU) mortality in severely ill patients. Our goal was to evaluate the prognostic value of the SOFA score as well as trends in SOFA score for ICU mortality in COVID-19 patients. METHODS: All consecutive patients with confirmed COVID-19 pneumonia admitted to the ICU between March 13th, 2020, and October 17th, 2020 were included in this retrospective cohort study. The worst SOFA score was evaluated daily. Multiple logistic regression models were used to evaluate the predictive value of SOFA in ICU mortality. RESULTS: 103 patients were included in this study. 30 patients (29%) died during their ICU stay and 73 (71%) patients were discharged alive. The ICU admission SOFA score was 5.2 ± 3.3 in ICU non-survivors vs. 4.3 ± 2.9 in ICU survivors (P = 0.15). The maximum SOFA score in ICU non-survivors was 11.7 ± 4.7 vs. 7.4 ± 4.3 in ICU survivors. SOFA scores increased the first week in both survivors and non-survivors, but the increase was less pronounced in survivors. In the multiple logistic regression models, neither admission SOFA score nor combination with delta SOFA in the first 48 hours was statistically significantly related to ICU mortality. Only the maximum SOFA score remained significant (OR = 1.23, 95% CI: 1.11-1.37, P < 0.001) in the multiple logistic models with an AUC of 0.91. CONCLUSIONS: Evaluation of SOFA scores in the first 48 hours after ICU admission is not a good prognostic indicator in COVID-19 patients. Only the maximum SOFA score was predictive for ICU mortality.

Intratumoural Treatment of 18 Cytologically Diagnosed Canine High-Grade Mast Cell Tumours With Tigilanol Tiglate.

Canine high-grade mast cell tumours (HGMCT) are associated with a poor prognosis, are inherently more invasive, and have higher rates of local recurrence. The primary aim of this retrospective study was to assess the efficacy of intratumoural tigilanol tiglate (TT) as a local treatment option. Eighteen dogs with mast cell tumours (MCT) cytologically diagnosed by veterinary pathologists as either high-grade or suspected high-grade MCT were treated with TT. The TT dose was based on tumour volume (0.5 mg TT/cm3 tumour volume) and delivered intratumourally using a Luer lock syringe and a fanning technique to maximise distribution throughout the tumour mass. Efficacy was assessed on the presence/absence of a complete response (CR) to therapy at days 28 and 84 using response evaluation criteria in solid tumours (RECIST). For dogs not achieving a CR after 28 days, the protocol was repeated with a second intratumoural TT injection. Ten out of 18 dogs (56%) in this study achieved and maintained a CR to at least 84 days after their first or second treatment. Six patients were alive and available for evaluation at 2 years, three of those were recurrence free, and a further three patients were recurrence free following a second treatment cycle. Tigilanol tiglate shows efficacy for local treatment of HGMCT, with higher efficacy noted with a second injection if a CR was not achieved following the first treatment. In the event of treatment site recurrence (TSR), the tumour may be controlled with additional treatment cycles. Tigilanol tiglate provides an alternative local treatment approach to dogs with HGMCT that would either pose an unacceptable anaesthetic risk or the tumour location provides a challenge when attempting surgical excision.

Wound formation, wound size, and progression of wound healing after intratumoral treatment of mast cell tumors in dogs with tigilanol tiglate.

BACKGROUND: Tigilanol tiglate (TT) is a novel small molecule for intratumoral treatment of nonmetastatic mast cell tumors (MCTs) in dogs. In a randomized controlled clinical study, 75% of dogs that received a single TT treatment achieved complete resolution of the MCT by 28 days, with no recurrence in 93% of dogs at 84 days. Critical to TT's efficacy was the area of the wound (tissue deficit) after slough of the necrotic tumor relative to pretreatment tumor volume. OBJECTIVES: To analyze data collected during the previous study to (a) describe wounds after slough of treated MCTs and (b) identify determinants of wound area and speed of wound healing. METHODS: Wound presence, condition, and area were determined from clinical records of 117 dogs over 84 days after a single intratumoral TT treatment. RESULTS: Tumor slough occurred 3 to 14 days after treatment, exposing granulation tissue in the wound bed. Wound area after tumor slough in general was related to pretreatment tumor volume, with maximal recorded wound area fully evident in 89% of dogs by day 7. In dogs achieving complete tumor resolution, all wounds were left to heal by secondary intention. Bandaging and other wound management interventions only were required in 5 dogs. Time to healing (ie, full re-epithelialization of treatment site) depended on wound area and location on the body, with most wounds being fully healed between 28 and 42 days after treatment. CONCLUSIONS: Wound area and healing after slough of TT-treated tumors follow a consistent clinical pattern for most dogs.

Tigilanol Tiglate-Mediated Margins: A Comparison With Surgical Margins in Successful Treatment of Canine Mast Cell Tumours.

Tigilanol tiglate (TT) is a novel small molecule registered as a veterinary pharmaceutical for intratumoural treatment of canine mast cell tumours (MCTs). The drug has a multifactorial mode of action resulting in rapid destruction of the treated tumour by haemorrhagic necrosis and subsequent slough of the necrotic tumour to reveal a tissue deficit that is left to heal by second intention with minimal to no veterinary intervention. Here we introduce the concept of TT-mediated margins, the calculated margin of tissue loss analogous to surgically applied margins to help clinicians conceptualise tissue deficits formed following tumour destruction by TT relative to surgical excision. We used data from 51 dogs that were recurrence-free 12 months after a single administered TT dose into a single target MCT <10 cm3 in volume in a randomised, controlled clinical trial in the USA. We calculated TT-mediated margins based on length of the longest axis of (i) the tumour prior to treatment and (ii) the maximum tissue deficit formed 7-14 days after TT treatment. We compared these TT-mediated margins for each tumour to two surgical approaches to MCT excision in general practise: modified proportional margins (with 2 cm upper limit) and 3 cm fixed margins. For most dogs, TT-mediated margins were less than half the length of the margins calculated for the two surgical approaches in removing the same tumour. There was a trend for TT-mediated margins to increase with increasing tumour volume. Nonetheless, even for the larger tumours in this study (>2 cm3 volume), 50% of TT-mediated margins were less than half the length of the two surgical margins. Eighteen cases were lower limb MCTs, sites often surgically challenging in veterinary practise. On these lower limbs, TT-mediated margins were less than half the length of the corresponding proportional margins in 56% of cases and larger than proportional margins in only two cases. This study suggests that, in many cases, smaller and more targeted margins could be expected when treating MCTs <10 cm3 volume with TT compared with surgical excision. TT-mediated margins are a novel approach to conceptualise tissue deficits after intratumoural TT treatment.

Randomized controlled clinical study evaluating the efficacy and safety of intratumoral treatment of canine mast cell tumors with tigilanol tiglate (EBC-46).

OBJECTIVE: To evaluate the efficacy and safety of tigilanol tiglate (TT) for local intratumoral treatment of mast cell tumors (MCTs) in dogs. METHODS: A randomized controlled clinical study in 2 phases involving 123 dogs with cytologically diagnosed MCT. Phase 1 compared 81 TT-treated dogs with 42 control dogs; phase 2 allowed TT treatment of control dogs and retreatment of dogs that failed to achieve tumor resolution after TT treatment in phase 1. Tigilanol tiglate (1 mg/mL) was injected intratumorally with dose based on tumor volume. Concomitant medications were used to minimize potential for MCT degranulation. Modified response evaluation criteria in solid tumors were used to evaluate treatment response at 28 and 84 days. Adverse events and quality of life were also assessed. RESULTS: A single TT treatment resulted in 75% complete response (CR) (95% confidence interval [CI] = 61-86) by 28 days, with no recurrence in 93% (95% CI = 82-97) of dogs by 84 days. Eight TT-treated dogs that did not achieve CR in phase 1 achieved CR after retreatment, increasing the overall CR to 88% (95% CI = 77-93). Control dogs had 5% CR (95% CI = 1-17) at 28 days. Wound formation after tumor slough and wound size relative to tumor volume were strongly associated with efficacy. Adverse events typically were low grade, transient, and directly associated with TT's mode of action. CONCLUSIONS: Tigilanol tiglate is efficacious and well tolerated, providing a new option for the local treatment of MCTs in dogs.

Impact of duration of perioperative antibiotic prophylaxis on development of fracture-related infection in open fractures.

INTRODUCTION: Infection is a common complication of open fractures potentially leading to nonunion, functional loss, and even amputation. Perioperative antibiotic prophylaxis (PAP) is standard practice for infection prevention in the management of open fractures. However, optimal duration of PAP remains controversial. The objectives were to assess whether PAP duration is independently associated with infection in open fractures and if administration of PAP beyond the commonly-recommended limit of 72 h has any effect on the infection rate. MATERIALS AND METHODS: Over a 14-year period from 2003 to 2017, 530 skeletally-mature patients with operatively-treated, non-pathologic, long-bone open fractures were treated at one institution. Twenty-eight patients were excluded because of death or loss to follow-up and the remaining 502 patients (with 559 open fractures) who completed a 24-month follow-up were included in this retrospective study. The outcome was fracture-related infection (FRI), defined by the criteria of a recent consensus definition. A logistic generalized estimating equations regression model was conducted, including PAP duration and variables selected by a least absolute shrinkage and selection operator (LASSO) method, to assess the association between PAP duration and FRI. Propensity score analysis using a 72-h cut-off was performed to further cope with confounding. RESULTS: PAP duration, adjusted for the LASSO selected predictors, was independently associated with FRI (OR: 1.11 [95%CI, 1.04-1.19] for every one-day increase in PAP duration, p = 0.003). PAP duration longer than 72 h did not significantly increase the odds for FRI compared to shorter durations (p = 0.06, analysis adjusted for propensity score). CONCLUSIONS: This study found no evidence that administration of prophylactic antibiotics beyond 72 h in patients with long-bone open fractures is warranted. Analyses adjusted for known confounders even revealed a higher risk for FRI for longer PAP. However, this effect cannot necessarily be considered as causal and further research is needed.

Use of the Intratumoural Anticancer Drug Tigilanol Tiglate in Two Horses.

Tigilanol tiglate is a novel small molecule approved as a veterinary pharmaceutical in Europe for intratumoural treatment of non-metastatic, non-resectable canine mast cell tumors. The drug has a "tumor agnostic" mode of action associated with induction of an acute inflammatory response at the treatment site, immune cell recruitment, and disruption of tumor vasculature. Consequently, tigilanol tiglate has potential in treating a range of tumor types in humans and companion animals. However, it is likely that species-specific dosing and concomitant medication protocols will be required, especially to manage the drug-induced acute inflammatory response at the treatment site. As an initial step in evaluating tigilanol tiglate for treating cutaneous tumors in horses, we developed an equine-specific protocol involving (a) a 30% reduction in intratumoural tigilanol tiglate dose rate compared to that used in dogs, and (b) a regime of concomitant medications to manage the drug-induced acute inflammatory response at the treatment site. Here we report a preliminary study in two horses using the protocol to treat (i) an aggressive fibroblastic sarcoid that had recurred following surgical excision and (ii) a fast-growing peri-ocular squamous cell carcinoma. Clinical response to tigilanol tiglate treatment in these cases was similar to that observed in canine and human patients. Localized inflammation and bruising developed rapidly at the treatment site with haemorrhagic necrosis of the tumor evident within 24 h. Slough of necrotic tumor mass occurred within 6-16 days followed by infill of the tissue defect and full re-epithelialisation of the treatment site with good functional outcome. Drug-induced inflammation and oedema at the treatment site were well controlled by the concomitant medications and largely resolved within 3 days, while the wound that formed following tumor slough healed uneventfully. Both patients displayed minor lethargy during the first 36 h after treatment and localized treatment-site discomfort was apparent over the first 3-5 days. There was no evidence of recurrence of the sarcoid at 93 days, or the squamous cell carcinoma at 189 days. The results from this study support continued development and evaluation of tigilanol tiglate as a potential future treatment option for cutaneous equine tumors.

Genomic characterization of a novel poxvirus from a flying fox: evidence for a new genus?

The carcass of an Australian little red flying fox (Pteropus scapulatus) which died following entrapment on a fence was submitted to the laboratory for Australian bat lyssavirus exclusion testing, which was negative. During post-mortem, multiple nodules were noted on the wing membranes, and therefore degenerate PCR primers targeting the poxvirus DNA polymerase gene were used to screen for poxviruses. The poxvirus PCR screen was positive and sequencing of the PCR product demonstrated very low, but significant, similarity with the DNA polymerase gene from members of the Poxviridae family. Next-generation sequencing of DNA extracted from the lesions returned a contig of 132 353 nucleotides (nt), which was further extended to produce a near full-length viral genome of 133 492 nt. Analysis of the genome revealed it to be AT-rich with inverted terminal repeats of at least 1314 nt and to contain 143 predicted genes. The genome contains a surprisingly large number (29) of genes not found in other poxviruses, one of which appears to be a homologue of the mammalian TNF-related apoptosis-inducing ligand (TRAIL) gene. Phylogenetic analysis indicates that the poxvirus described here is not closely related to any other poxvirus isolated from bats or other species, and that it likely should be placed in a new genus.

Evaluation of Inutec SP1 as a new carrier in the formulation of solid dispersions for poorly soluble drugs.

Solid dispersions made up of itraconazole and Inutec SP1, a new polymeric surfactant, were prepared by spray drying and hot-stage extrusion. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) were used to evaluate the miscibility of the components of the dispersions, and dissolution experiments were performed in simulated gastric fluid without pepsin (SGFsp) to evaluate the pharmaceutical performance of itraconazole from the solid dispersions. DSC analysis showed that the solid dispersions are phase separated systems made up of glassy and crystalline itraconazole and amorphous Inutec SP1. The amount of crystalline drug substance was higher in the dispersions prepared by hot-stage extrusion and was clearly a function of the drug concentration. Since no crystallinity could be detected by XRD points to the fact that the crystallites formed are very small in size. Despite the presence of glassy and crystalline clusters, the dissolution properties of the solid dispersions were significantly improved in comparison to pure itraconazole (glassy or crystalline) or physical mixtures with Inutec SP1. This study proves the potential of the new polymeric surfactant as a carrier in the formulation of solid dispersions for poorly soluble drugs.