Bioavailability of three novel oral, sustained-release pellets, relative to an immediate-release tablet containing 500 mg flucytosine: A randomized, open-label, crossover study in healthy volunteers.

The opportunistic fungal infection cryptococcal meningoencephalitis is a major cause of death among people living with HIV in sub-Saharan Africa. We report pharmacokinetic (PK) and safety data from a randomized, four-period crossover phase I trial of three sustained-release (SR) oral pellet formulations of 5-flucytosine conducted in South Africa. These formulations were developed to require less frequent administration, to provide a convenient alternative to the current immediate release (IR) formulation, A. Formulations B, C, and D were designed to release 5-flucytosine as a percentage of the nominal dose in vitro. We assessed their safety and PK profiles in a single dose (1 × 3000 mg at 0 h), relative to commercial IR tablets (Ancotil 500 mg tablets; 3 × 500 mg at 0 h and 3 × 500 mg at 6 h) in healthy, fasted participants. Forty-two healthy participants were included. All treatments were well-tolerated. The primary PK parameters, maximum observed plasma concentration (Cmax ) and area under the concentration-time profiles, were significantly lower for the SR formulations than for the IR tablets, and the geometric mean ratios fell outside the conventional bioequivalence limits. The median maximum time to Cmax was delayed for the SR pellets. Physiologically-based PK modeling indicated a twice-daily 6400 mg dose of SR formulation D in fasted condition would be optimal for further clinical development. This regimen is predicted to result in a rapid steady-state plasma exposure with effective and safe trough plasma concentration and Cmax values, within the therapeutic boundaries relative to plasma exposure after four times per day administration of IR tablets (PACTR202201760181404).

Tracing back primed resistance in cancer via sister cells.

Exploring non-genetic evolution of cell states during cancer treatments has become attainable by recent advances in lineage-tracing methods. However, transcriptional changes that drive cells into resistant fates may be subtle, necessitating high resolution analysis. Here, we present ReSisTrace that uses shared transcriptomic features of sister cells to predict the states priming treatment resistance. Applying ReSisTrace in ovarian cancer cells perturbed with olaparib, carboplatin or natural killer (NK) cells reveals pre-resistant phenotypes defined by proteostatic and mRNA surveillance features, reflecting traits enriched in the upcoming subclonal selection. Furthermore, we show that DNA repair deficiency renders cells susceptible to both DNA damaging agents and NK killing in a context-dependent manner. Finally, we leverage the obtained pre-resistance profiles to predict and validate small molecules driving cells to sensitive states prior to treatment. In summary, ReSisTrace resolves pre-existing transcriptional features of treatment vulnerability, facilitating both molecular patient stratification and discovery of synergistic pre-sensitizing therapies.

Like I said, I would not have likely gotten up otherwise: patient experiences of using an Activity Board after abdominal cancer surgery.

PURPOSE: Most patients treated in a hospital setting are fully or partially immobilised. The Activity Board (Träningstavlan® Phystec) is a useful tool to enhance mobilisation after major abdominal cancer surgery. Knowledge of patient experiences of the mobilisation tool is crucial in implementing the Activity Board in health care. This study aimed to describe patient experiences of using the Activity Board after surgery for abdominal cancer. MATERIALS AND METHODS: Semi-structured face-to-face interviews were conducted in 15 patients who underwent abdominal surgery due to colorectal, ovarian or urinary bladder cancer. All 15 patients (mean age 67.7 years, range 40-86) used the Activity Board postoperatively. The interviews were transcribed verbatim and analysed according to inductive content analysis. RESULTS: The overarching theme that emerged from the interviews was that "enabling participation facilitates empowerment over rehabilitation". Three categories supported the theme: prerequisites for using the Activity Board, the value of using supportive behavioural techniques, and the possibility to influence the patients' care. CONCLUSIONS: These findings suggest that the Activity Board could be a viable tool that activates the person-centred postoperative rehabilitation process by cooperating with the medical team at the hospital ward.Implications for rehabilitationPatients who are in hospital due to cancer surgery are often immobilised, which increases the risk of complications.The Activity Board can stimulate the patients to participate in the rehabilitation process in a more active way.The Activity Board can be used to improve and clarify the person-centred approach in hospital settings.

Bipartite network models to design combination therapies in acute myeloid leukaemia.

Combination therapy is preferred over single-targeted monotherapies for cancer treatment due to its efficiency and safety. However, identifying effective drug combinations costs time and resources. We propose a method for identifying potential drug combinations by bipartite network modelling of patient-related drug response data, specifically the Beat AML dataset. The median of cell viability is used as a drug potency measurement to reconstruct a weighted bipartite network, model drug-biological sample interactions, and find the clusters of nodes inside two projected networks. Then, the clustering results are leveraged to discover effective multi-targeted drug combinations, which are also supported by more evidence using GDSC and ALMANAC databases. The potency and synergy levels of selective drug combinations are corroborated against monotherapy in three cell lines for acute myeloid leukaemia in vitro. In this study, we introduce a nominal data mining approach to improving acute myeloid leukaemia treatment through combinatorial therapy.

Pesticide-induced multigenerational effects on amphibian reproduction and metabolism.

Underlying drivers of species extinctions need to be better understood for effective conservation of biodiversity. Nearly half of all amphibian species are at risk of extinction, and pollution may be a significant threat as seasonal high-level agrochemical use overlaps with critical windows of larval development. The potential of environmental chemicals to reduce the fitness of future generations may have profound ecological and evolutionary implications. This study characterized effects of male developmental exposure to environmentally relevant concentrations of the anti-androgenic pesticide linuron over two generations of offspring in Xenopus tropicalis frogs. The adult male offspring of pesticide-exposed fathers (F1) showed reduced body size, decreased fertility, and signs of endocrine system disruption. Impacts were further propagated to the grand-offspring (F2), providing evidence of transgenerational effects in amphibians. The adult F2 males demonstrated increased weight and fat body palmitoleic-to-palmitic acid ratio, and decreased plasma glucose levels. The study provides important cross-species evidence of paternal epigenetic inheritance and pollutant-induced transgenerational toxicity, supporting a causal and complex role of environmental contamination in the ongoing species extinctions, particularly of amphibians.

Correction to: Drug Absorption Parameters Obtained Using the Isolated Perfused Rat Lung Model Are Predictive of Rat In Vivo Lung Absorption.

A Correction to sthis paper has been published: https://doi.org/10.1208/s12248-020-00545-x.

Pulmonary drug absorption and systemic exposure in human: Predictions using physiologically based biopharmaceutics modeling.

Systemic exposure of inhaled drugs is used to estimate the local lung exposure and assess systemic side effects for drugs with local pharmacological targets. Predicting systemic exposure is therefore central for successful development of drugs intended to be inhaled. Currently, these predictions are based mainly on data from in vitro experiments, but the accuracy of these predictions might be improved if they were based on data with higher physiological relevance. In this study, systemic exposure was simulated by applying biopharmaceutics input parameters from isolated perfused rat lung (IPL) data to a lung model developed in MoBi® as an extension to the full physiologically-based pharmacokinetic (PBPK) model in PK-Sim®. These simulations were performed for a set of APIs with a variety of physicochemical properties and formulation types. Simulations based on rat IPL data were also compared to simulations based on in vitro data. The predictive performances of the simulations were evaluated by comparing simulated plasma concentration-time profiles to clinical observations after pulmonary administration. Simulations using IPL-based input parameters predicted systemic exposure well, with predicted AUCs within two-fold of the observed value for nine out of ten drug compounds/formulations, and predicted Cmax values within two-fold for eight out of ten drug compounds/formulations. Simulations using input parameters based on IPL data performed generally better than simulations based on in vitro input parameters. These results suggest that the developed model in combination with IPL data can be used to predict human lung absorption for compounds with different physicochemical properties and types of inhalation formulations.

Drug Absorption Parameters Obtained Using the Isolated Perfused Rat Lung Model Are Predictive of Rat In Vivo Lung Absorption.

The ex vivo isolated perfused rat lung (IPL) model has been demonstrated to be a useful tool during drug development for studying pulmonary drug absorption. This study aims to investigate the potential use of IPL data to predict rat in vivo lung absorption. Absorption parameters determined from IPL data (ex vivo input parameters) in combination with intravenously determined pharmacokinetic data were used in a biopharmaceutics model to predict experimental rat in vivo plasma concentration-time profiles and lung amount after inhalation of five different inhalation compounds. The performance of simulations using ex vivo input parameters was compared with simulations using in vitro input parameters, to determine whether and to what extent predictability could be improved by using input parameters determined from the more complex ex vivo model. Simulations using ex vivo input parameters were within twofold average difference (AAFE < 2) from experimental in vivo data for all compounds except one. Furthermore, simulations using ex vivo input parameters performed significantly better than simulations using in vitro input parameters in predicting in vivo lung absorption. It could therefore be advantageous to base predictions of drug performance on IPL data rather than on in vitro data during drug development to increase mechanistic understanding of pulmonary drug absorption and to better understand how different substance properties and formulations might affect in vivo behavior of inhalation compounds.

Prolyl 4-hydroxylase subunit alpha 1 (P4HA1) is a biomarker of poor prognosis in primary melanomas, and its depletion inhibits melanoma cell invasion and disrupts tumor blood vessel walls.

Melanoma is an unpredictable, highly metastatic malignancy, and treatment of advanced melanoma remains challenging. Novel molecular markers based on the alterations in gene expression and the molecular pathways activated or deactivated during melanoma progression are needed for predicting the course of the disease already in primary tumors and for providing new targets for therapy. Here, we sought to identify genes whose expression in primary melanomas correlate with patient disease-specific survival using global gene expression profiling. Many of the identified potential markers of poor prognosis were associated with the epithelial-mesenchymal transition, extracellular matrix formation, and angiogenesis. We studied further the significance of one of the genes, prolyl 4-hydroxylase subunit alpha 1 (P4HA1), in melanoma progression. P4HA1 depletion in melanoma cells reduced cell adhesion, invasion, and viability in vitro. In melanoma xenograft assays, we found that P4HA1 knockdown reduced melanoma tumor invasion as well as the deposition of collagens, particularly type IV collagen, in the interstitial extracellular matrix and in the basement membranes of tumor blood vessels, leading to vessel wall rupture and hemorrhages. Further, P4HA1 knockdown reduced the secretion of collagen triple helix repeat containing 1 (CTHRC1), an important mediator of melanoma cell migration and invasion, in vitro and its deposition around tumor blood vessels in vivo. Taken together, P4HA1 is an interesting potential prognostic marker and therapeutic target in primary melanomas, influencing many aspects of melanoma tumor progression.

Pulmonary Dissolution of Poorly Soluble Compounds Studied in an ex Vivo Rat Lung Model.

Many inhaled drugs are poorly water soluble, and the dissolution rate is often the rate-limiting step in the overall absorption process. To improve understanding of pulmonary drug dissolution, four poorly soluble inhalation compounds (AZD5423 (a developmental nonsteroidal glucocorticoid), budesonide, fluticasone furoate (FF), and fluticasone propionate (FP)) were administered as suspensions or dry powders to the well-established isolated perfused rat lung (IPL) model. Two particle size distributions (d50 = 1.2 µm and d50 = 2.8 µm) were investigated for AZD5423. The pulmonary absorption rates of the drugs from the suspensions and dry powders were compared with historical absorption data for solutions to improve understanding of the effects of dissolution on the overall pulmonary absorption process for poorly soluble inhaled drugs. A physiologically based biopharmaceutical in silico model was used to analyze the experimental IPL data and to estimate a dissolution parameter ( kex vivo). A similar in silico approach was applied to in vitro dissolution data from the literature to obtain an in vitro dissolution parameter ( kin vitro). When FF, FP, and the larger particles of AZD5423 were administered as suspensions, drug dissolution was the rate-limiting step in the overall absorption process. However, this was not the case for budesonide, which has the highest aqueous solubility (61 µM), and the smaller particles of AZD5423, probably because of the increased surface area available for dissolution (d50 = 1.2 µm). The estimated dissolution parameters were ranked in accordance with the solubility of the drugs, and there was good agreement between kex vivo and kin vitro. The dry powders of all the compounds were absorbed more slowly than the suspensions, indicating that wetting is an important parameter for the dissolution of dry powders. A wetting factor was introduced to the in silico model to explain the difference in absorption profiles between the suspensions and dry powders where AZD5423 had the poorest wettability followed by FP and FF. The IPL model in combination with an in silico model is a useful tool for investigating pulmonary dissolution and improving understanding of dissolution-related parameters for poorly soluble inhaled compounds.

Pulmonary absorption - estimation of effective pulmonary permeability and tissue retention of ten drugs using an ex vivo rat model and computational analysis.

Permeation of inhaled drugs across the pulmonary epithelium can regulate the rate and extent of local drug absorption and hence the pulmonary tissue concentration. Therefore, understanding pulmonary epithelial transport could be important for successful design of novel inhaled medicines. To enhance understanding of pulmonary epithelial transport, drug transport data were generated for a set of inhaled compounds (n = 10) in the single-pass, isolated perfused rat lung model. A compartmental in silico model was used to estimate pulmonary permeability and tissue retention. The theoretical model was also used to re-analyze previously obtained historical drug transport data from the isolated perfused lung (n = 10) with re-circulating buffer. This was performed to evaluate the re-circulating model for assessing tissue retention measurements and to increase the number of data points. The tissue retention was an important parameter to estimate to be able to describe the drug transport profiles accurately of most of the investigated compounds. A relationship between the pulmonary permeability and the intrinsic (carrier-mediated transport inhibited) permeability of Caco-2 cell monolayers (n = 1-6) was also established. This correlation (R2 = 0.76, p < .0001) suggests that intrinsic Caco-2 permeability measurements could offer early predictions of the passive transcellular permeability of lung epithelium to candidate drugs. Although, for some compounds a deviation from the correlation suggests that other transport mechanisms may coexist. The compartmental in silico model was successful in describing the pulmonary drug transport profiles of the investigated compounds and has potential for further development to investigate the effects of formulations with different features on the pulmonary overall absorption rate.

Divergent roles of lysyl oxidase family members in ornithine decarboxylase- and RAS-transformed mouse fibroblasts and human melanoma cells.

We have previously shown that proto-oncoprotein c-Jun is activated in ornithine decarboxylase (ODC)- and RAS-transformed mouse fibroblasts, and that the transformed morphology of these cells can be reversed by expressing the transactivation domain deletion mutant of c-Jun (TAM67). Here, we found that lysyl oxidase (Lox), encoding an extracellular matrix-modifying enzyme, is downregulated in a c-Jun-dependent manner in ODC-transformed fibroblasts (Odc cells). In addition to Lox, the Lox family members Lox-like 1 and 3 (Loxl1 and Loxl3) were found to be downregulated in Odc as well as in RAS-transformed fibroblasts (E4), whereas Lox-like 4 (Loxl4) was upregulated in Odc and downregulated in E4 cells compared to normal N1 fibroblasts. Tetracycline-regulatable LOX re-expression in Odc cells led to inhibition of cell growth and invasion in three-dimensional Matrigel in an activity-independent manner. On the contrary, LOX and especially LOXL2, LOXL3, and LOXL4 were found to be upregulated in several human melanoma cell lines, and LOX inhibitor B-aminopropionitrile inhibited the invasive growth of these cells particularly when co-cultured with fibroblasts in Matrigel. Knocking down the expression of LOX and especially LOXL2 in melanoma cells almost completely abrogated the invasive growth capability. Further, LOXL2 was significantly upregulated in clinical human primary melanomas compared to benign nevi, and high expression of LOXL2 in primary melanomas was associated with formation of metastases and shorter survival of patients. Thus, our studies reveal that inactive pro-LOX (together with Lox propeptide) functions as a tumor suppressor in ODC- and RAS-transformed murine fibroblasts by inhibiting cell growth and invasion, and active LOX and LOXL2 as tumor promoters in human melanoma cells by promoting their invasive growth.

Excised segments of rat small intestine in Ussing chamber studies: A comparison of native and stripped tissue viability and permeability to drugs.

Excised rat intestinal tissue mounted in an Ussing chamber can be used for intestinal permeability assessments in drug development. The outer layer of the intestine, the serosa and part of the muscle layer, is traditionally removed since it is considered a barrier to the diffusion of nutrients and oxygen as well as to that of pharmaceutical substances. However, the procedure for removing the serosal-muscle layer, i.e. stripping, is a technically challenging process in the pre-experimental preparation of the tissue which may result in tissue damage and reduced viability of the segment. In this study, the viability of stripped and native (non-stripped) rat small intestine tissue segments mounted in Ussing chambers was monitored and the apparent permeability of the tissue to a set of test compounds across both tissue preparations was determined. Electrical measurements, in particular the potential difference (PD) across the intestinal membrane, were used to evaluate the viability. In this study, there were no differences in initial PD (health status of the tissue) or PD over time (viability throughout the experiment) between native and stripped rat jejunum segments. Overall, there were also no significant differences in permeability between stripped and native rat intestinal tissue for the compounds in this study. Based on these results, we propose that stripping can be excluded from the preparation procedures for rat jejunal tissue for permeability studies when using the Ussing chamber technique.

Gene expression analyses of primary melanomas reveal CTHRC1 as an important player in melanoma progression.

Melanoma is notorious for its high tendency to metastasize and its refractoriness to conventional treatments after metastasis, and the responses to most targeted therapies are short-lived. A better understanding of the molecular mechanisms behind melanoma development and progression is needed to develop more effective therapies and to identify new markers to predict disease behavior. Here, we compared the gene expression profiles of benign nevi, and non-metastatic and metastatic primary melanomas to identify any common changes in disease progression. We identified several genes associated with inflammation, angiogenesis, and extracellular matrix modification to be upregulated in metastatic melanomas. We selected one of these genes, collagen triple helix repeat containing 1 (CTHRC1), for detailed analysis, and found that CTHRC1 was expressed in both melanoma cells and the associated fibroblasts, as well as in the endothelium of tumor blood vessels. Knockdown of CTHRC1 expression by shRNAs in melanoma cells inhibited their migration in Transwell assays and their invasion in three-dimensional collagen and Matrigel matrices. We also elucidated the possible down-stream effectors of CTHRC1 by gene expression profiling of the CTHRC1-knockdown cells. Our analyses showed that CTHRC1 is regulated coordinately with fibronectin and integrin ß3 by the pro-invasive and -angiogenic transcription factor NFATC2. We also found CTHRC1 to be a target of TFGß and BRAF. These data highlight the importance of tumor stroma in melanoma progression. Furthermore, CTHRC1 was recognized as an important mediator of melanoma cell migration and invasion, providing together with its regulators-NFATC2, TGFß, and BRAF-attractive therapeutic targets against metastatic melanomas.