Plasma concentrations of buprenorphine administered via matrix-type transdermal patches applied at three different anatomical locations in healthy adult horses.

Background: Anatomical location-dependent differences in transdermal opioid penetration are well described in human patients. Although this has been investigated in horses with fentanyl, there is no literature available on location-dependent plasma buprenorphine concentrations when administered as a transdermal matrix-type patch. Objective: This study aims to compare the plasma concentrations achieved from the matrix-type transdermal buprenorphine patches placed at different anatomical sites (metacarpus, gaskin, and ventral tail base) in healthy adult horses. Study design: This is a randomized experimental study with a Latin square design. Methods: Six adult horses were given each of three treatments with a minimum 10-day washout period. For each treatment, two 20 µg h-1 matrix-type buprenorphine patches were applied to the ventral aspect of the tail base (TailTDP), metacarpus region (MetacarpusTDP), or gaskin region (GaskinTDP). Whole blood samples (for determination of buprenorphine concentration) and physiological variables were collected before (0 h) and at 0.5, 2, 4, 6, 8, 10, 12, 16, 24, 32, 48, 56, 72, 96 and 120 h after patches were applied. The patches were removed 96 h following placement and were analyzed for residual buprenorphine content. Buprenorphine concentrations were measured in plasma by LC-MS/MS. A mixed-effects model was used to analyze the physiological variables. Results: Between the three treatment groups, there was no change in physiological variables across timepoints as compared to baseline and when compared to each other in a single horse and between horses (p > 0.3). When comparing all three locations, the buprenorphine uptake was observed to be more consistent with respect to measurable plasma concentrations >0.1 ng ml-1 when applied to the ventral aspect of the tail base. In the TailTDP group, the mean plasma buprenorphine concentrations were >0.1 ng ml-1 from 2 to 32 h. The highest group mean was 0.25 ng ml-1 noted at 4 h. Conclusions: The metacarpal and gaskin regions presented more erratic and inconsistent buprenorphine uptake and plasma concentrations as compared to the ventral aspect of the tail base. Further research must be directed at investigating the optimal dose, achievable duration of analgesia, change in measurable plasma concentrations, and behavioral and systemic effects.

Dose escalation of tolinapant (ASTX660) in combination with standard radical chemoradiotherapy in cervical cancer : a study protocol for a phase 1b TiTE-CRM clinical trial (CRAIN) in UK secondary care centres.

BACKGROUND: Cervical cancer is the fourth most common cancer in women, with an estimated 342,000 deaths worldwide in 2020. Current standard of care in the UK for locally advanced cervical cancer is concurrent chemoradiotherapy with weekly cisplatin, yet 5-year overall survival rates are only 65% with a distant relapse rate of 50%. Inhibitors of Apoptosis Proteins (IAPs) are often overexpressed in cancer cells and associated with tumour progression and resistance to treatment. Tolinapant, developed by Astex Pharmaceuticals, is an IAP antagonist with an additional mechanism of action via down-regulation of NF-kB, an important regulator in cervical cancer. Preclinical studies performed using tolinapant in combination with cisplatin and radiotherapy showed inhibition of tumour growth and enhanced survival. There is therefore a strong rationale to combine tolinapant with chemoradiotherapy (CRT). METHODS: CRAIN is a phase Ib open-label, dose escalation study to characterise the safety, tolerability and initial evidence for clinical activity of tolinapant when administered in combination with cisplatin based CRT. Up to 42 patients with newly diagnosed cervix cancer will be recruited from six UK secondary care sites. The number of participants and the duration of the trial will depend on toxicities observed and dose escalation decisions, utilising a TiTE-CRM statistical design. Treatment will constist of standard of care CRT with 45 Gy external beam radiotherapy given in 25 daily fractions over 5 weeks with weekly cisplatin 40mg/m2. This is followed by brachytherapy for which common schedules will be 28 Gy in 4 fractions high-dose-rate or 34 Gy in 2 fractions pulsed-dose-rate. Tolinapant will be administered in fixed dose capsules taken orally daily for seven consecutive days as an outpatient on alternate weeks (weeks 1, 3, 5) during chemoradiation. Dose levels for tolinapant which will be assessed are: 60 mg; 90 mg (starting level); 120 mg; 150 mg; 180 mg. Escalation will be guided by emerging safety data and decisions by the Safety Review Committee. DISCUSSION: If this trial determines a recommended phase II dose and shows tolinapant to be safe and effective in combination with CRT, it would warrant future phase trials. Ultimately, we hope to provide a synergistic treatment option for these patients to improve outcome. TRIAL REGISTRATIONS: EudraCT Number: 2021-006555-34 (issued 30th November 2021); ISRCTN18574865 (registered 30th August 2022).

Exploring the interdependence of calcium and chloride activation of O2 evolution in photosystem II.

Calcium and chloride are activators of oxygen evolution in photosystem II (PSII), the light-absorbing water oxidase of higher plants, algae, and cyanobacteria. Calcium is an essential part of the catalytic Mn4CaO5 cluster that carries out water oxidation and chloride has two nearby binding sites, one of which is associated with a major water channel. The co-activation of oxygen evolution by the two ions is examined in higher plant PSII lacking the extrinsic PsbP and PsbQ subunits using a bisubstrate enzyme kinetics approach. Analysis of three different preparations at pH 6.3 indicates that the Michaelis constant, KM, for each ion is less than the dissociation constant, KS, and that the affinity of PSII for Ca2+ is about ten-fold greater than for Cl-, in agreement with previous studies. Results are consistent with a sequential binding model in which either ion can bind first and each promotes the activation by the second ion. At pH 5.5, similar results are found, except with a higher affinity for Cl- and lower affinity for Ca2+. Observation of the slow-decaying Tyr Z radical, YZ•, at 77 K and the coupled S2YZ• radical at 10 K, which are both associated with Ca2+ depletion, shows that Cl- is necessary for their observation. Given the order of electron and proton transfer events, this indicates that chloride is required to reach the S3 state preceding Ca2+ loss and possibly for stabilization of YZ• after it forms. Interdependence through hydrogen bonding is considered in the context of the water environment that intervenes between Cl- at the Cl-1 site and the Ca2+/Tyr Z region.

The pharmacokinetics and pharmacodynamics of fentanyl administered via transdermal patch in horses.

Introduction: Understanding the pharmacokinetics and pharmacodynamics of fentanyl in horses is crucial for optimizing pain management strategies in veterinary medicine. Methods: Six adult horses were enrolled in a randomized crossover design. Treatments included: placebo, two 100 mcg/h patches (LDF), four 100 mcg/h patches (MDF), and six 100 mcg/h patches (HDF). Patches were in place for 72 h. Blood was obtained for fentanyl plasma concentration determination, thermal threshold, mechanical threshold, heart rate, respiratory rate, and rectal temperature were obtained prior patch placement and at multiple time points following patch placement for the following 96 h. Fentanyl plasma concentration was determined using LC-MS/MS. Data were analyzed using a generalized mixed effects model. Results: Mean (range) maximum plasma concentration (Cmax), time to Cmax, and area under the curve extrapolated to infinity were 1.39 (0.82-1.82), 2.64 (1.21-4.42), 4.11 (2.78-7.12) ng/ml, 12.7 (8.0-16.0), 12.7 (8.0-16.0), 12 (8.0-16.0) h, 42.37 (27.59-55.56), 77.24 (45.62-115.06), 120.34 (100.66-150.55) h ng/ml for LDF, MDF, and HDF, respectively. There was no significant effect of treatment or time on thermal threshold, mechanical threshold, respiratory rate, or temperature (p > 0.063). There was no significant effect of treatment on heart rate (p = 0.364). There was a significant effect of time (p = 0.003) on heart rate with overall heart rates being less than baseline at 64 h. Conclusions: Fentanyl administered via transdermal patch is well absorbed and well tolerated but does not result in an anti-nociceptive effect as measured by thermal and mechanical threshold at the doses studied.

Evaluation of physical variables, thermal nociceptive threshold testing and pharmacokinetics during placement of transdermal buprenorphine matrix-type patch in healthy adult horses.

Background: Matrix type transdermal buprenorphine patches have not been investigated in horses and may provide an effective means of providing continuous pain control for extended period and eliminating venous catheterization. Objective: Assessment of the physiological variables (heart rate, respiratory rate, body temperature) and thermal nociceptive threshold testing, and describing the pharmacokinetic profile of transdermal buprenorphine matrix-type patch (20 µg h-1 and 40 µg h-1 dosing) in healthy adult horses. Study design: Randomised experimental study with a Latin-square design. Methods: Six adult healthy horses received each of the three treatments with a minimum 10 day washout period. BUP0 horses did not receive a patch (control). BUP20 horses received one patch (20 µg h-1) applied on the ventral aspect of the tail base resulting in a dose of 0.03-0.04 µg kg-1 h-1. BUP40 horses received two patches placed alongside each other (40 µg h-1) on the tail base resulting in a dose of 0.07-0.09 µg kg-1 h-1. Whole blood samples (for determination of buprenorphine concentration), physiological variables and thermal threshold testing were performed before (0 h) and at 2, 4, 8, 12, 16, 24, 32, 40, 48, 56, 64, 72, and 96 h after patch application. The patches were removed 72 h following placement and were analyzed for residual buprenorphine content. Results: Between the three groups, there was no change in physiological variables across timepoints as compared to baseline (p > 0.1). With the higher dose, there was a significant increase in thermal thresholds from baseline values from 2 h until 48 h and these values were significantly higher than the group receiving the lower patch dose for multiple timepoints up to 40 h. 40 µg h-1 patch led to consistent measurable plasma concentrations starting at 2 h up to 96 h, with the mean plasma concentrations of > 0.1 ng/ml from 4 h to 40 h. Conclusions: 20 µg h-1 and 40 µg h-1 patch doses were well tolerated by all horses. At higher dose, plasma buprenorphine concentrations were more consistently measurable and blunted thermal thresholds for 48 h vs. 32 h with 20 µg h-1 dosing as compared to control.

Detection of endometrial cancer in cervico-vaginal fluid and blood plasma: leveraging proteomics and machine learning for biomarker discovery.

BACKGROUND: The anatomical continuity between the uterine cavity and the lower genital tract allows for the exploitation of uterine-derived biomaterial in cervico-vaginal fluid for endometrial cancer detection based on non-invasive sampling methodologies. Plasma is an attractive biofluid for cancer detection due to its simplicity and ease of collection. In this biomarker discovery study, we aimed to identify proteomic signatures that accurately discriminate endometrial cancer from controls in cervico-vaginal fluid and blood plasma. METHODS: Blood plasma and Delphi Screener-collected cervico-vaginal fluid samples were acquired from symptomatic post-menopausal women with (n = 53) and without (n = 65) endometrial cancer. Digitised proteomic maps were derived for each sample using sequential window acquisition of all theoretical mass spectra (SWATH-MS). Machine learning was employed to identify the most discriminatory proteins. The best diagnostic model was determined based on accuracy and model parsimony. FINDINGS: A protein signature derived from cervico-vaginal fluid more accurately discriminated cancer from control samples than one derived from plasma. A 5-biomarker panel of cervico-vaginal fluid derived proteins (HPT, LG3BP, FGA, LY6D and IGHM) predicted endometrial cancer with an AUC of 0.95 (0.91-0.98), sensitivity of 91% (83%-98%), and specificity of 86% (78%-95%). By contrast, a 3-marker panel of plasma proteins (APOD, PSMA7 and HPT) predicted endometrial cancer with an AUC of 0.87 (0.81-0.93), sensitivity of 75% (64%-86%), and specificity of 84% (75%-93%). The parsimonious model AUC values for detection of stage I endometrial cancer in cervico-vaginal fluid and blood plasma were 0.92 (0.87-0.97) and 0.88 (0.82-0.95) respectively. INTERPRETATION: Here, we leveraged the natural shed of endometrial tumours to potentially develop an innovative approach to endometrial cancer detection. We show proof of principle that endometrial cancers secrete unique protein signatures that can enable cancer detection via cervico-vaginal fluid assays. Confirmation in a larger independent cohort is warranted. FUNDING: Cancer Research UK, Blood Cancer UK, National Institute for Health Research.

Enhancing Nutrition Support for Esophageal Cancer Patients: Understanding Factors Influencing Feeding Tube Utilization.

Objective: We sought to identify factors that can predict esophageal cancer (EC) patients at high risk of requiring feeding tube insertion. Methods: A retrospective cohort review was conducted, including all patients diagnosed with EC at our cancer center from 2013 to 2018. Multivariate logistic regression was performed comparing the group that required a reactive feeding tube insertion to those who did not require any feeding tube insertion to identify risk factors. Results: A total of 350 patients were included in the study, and 132/350 (38%) patients received a feeding tube. 50 out of 132 (38%) patients had feeding tube inserted reactively. Severe dysphagia (OR 19.9, p < 0.001) at diagnosis and decision to undergo chemotherapy (OR 2.8, p = 0.008) appeared to be predictors for reactive feeding tube insertion. The reactive insertion group had a 7% higher rate of complications relating to feeding tube. Conclusion: Severe dysphagia at diagnosis and undergoing chemotherapy were identified as risk factors for requiring a feeding tube. Ultimately, the aim is to create a predictive tool that utilizes these risks factors to accurate identify high-risk patients who may benefit from prophylactic feeding tube insertion.

A role for Shugoshin in human cilia?

We have recently described a novel role for the conserved centromeric/kinetochore protein and cohesin protector, Shugoshin, in cilia of C. elegans. Worms are unusual in that the sole Shugoshin protein ( SGO-1 ) is dispensable for chromosome segregation but required for cilia function in fully differentiated sensory neurons. Depletion of sgo-1 leads to an array of sensory defects observed in other cilia mutants with a compromised diffusion barrier. Accordingly, SGO-1 loads to the base of cilia in sensory neurons and can be observed occupying the transition zone, the critical ciliary domain that regulates trafficking in and out of ciliary compartments. Here we start to address a potential conserved role in cilia for vertebrate Shugoshin by asking whether human Shugoshin can: (1) localize to cilia and (2) rescue defects due to Shugoshin depletion in C. elegans . Our preliminary results suggest that human Shugoshin is detectable in the cilia base but show limited functional conservation when expressed in C. elegans sensory neurons.