Uterine mesenchymal tumours: recent advances

Almost all uterine mesenchymal tumours have been historically classified as either smooth muscle or endometrial stromal neoplasms. Recent application of molecular techniques has identified numerous lesions with distinctive genetic abnormalities and clinicopathological characteristics. Newly discovered uterine sarcoma subtypes include high-grade endometrial stromal sarcomas with BCOR genetic abnormalities, fibrosarcoma-like uterine sarcomas with NTRK rearrangements and COL1A–PDGFRB fusions, as well as undifferentiated uterine sarcomas with SMARCA4 mutations. Novel PLAG1 and PGR fusions have been identified in subsets of myxoid and epithelioid leiomyosarcomas. Some uterine tumours resembling ovarian sex-cord tumour harbour GREB1 and ESR1 rearrangements. Histological and immunophenotypical features as well as underlying genetic abnormalities defining these lesions are discussed.     

Intercostal Nerve Block Using an Innovative Intraneedle Ultrasound Transducer: A Proof-of-Concept study

Intercostal nerve block is a widely used and effective approach to providing regional anesthesia in the thoracic region for pain relief. However, during ultrasound-guided intercostal nerve block, inaccurate identification of the anatomic structures or suboptimal positioning of the needle tip may result in complications and blockade failure. In this study, we designed an intraneedle ultrasound (INUS) system and validated its efficacy in identifying anatomic structures relevant to thoracic region anesthesia. The 20-MHz INUS transducer comprised a single lead magnesium niobate–lead titanate crystal, and gain was set to 20 dB. It fit into a regular 18G needle and emitted radiofrequency-mode ultrasound signals at 1 mm from the needle tip. One hundred intercostal punctures were performed in 10 piglets. Intercostal spaces were identified by surface ultrasound or palpation and located by inserting and advancing the INUS transducer needle until the appropriate anatomy was identified. Blockade success was defined by ideal saline and dye spreading and confirmed by dissection. The pleura had a distinctive ultrasound signal, and successful detection of the intercostal muscles, endothoracic fascia and double-layered parietal and visceral pleura was achieved in all 100 puncture attempts. INUS allows real-time identification of intercostal structures and facilitates successful intercostal nerve blocks.     

An Investigation of Oral Exposure Variability and Formulation Strategy: A Case Study of PI3Kδ Inhibitor and Physiologically Based Pharmacokinetic Modeling in Beagle Dogs

It is well acknowledged that drugs with poor aqueous solubility are often associated with poor oral absorption. Fortunately, drugs with a basic pKa can take advantage of solubilization in the stomach under the acidic environment to improve exposure. Consequently, high in vivo variability is often observed when stomach pH is altered. When issue encountered, enabling formulations are often used to solve the problem. However, each enabling formulation has its limitations and the situation can be further complicated by other absorption distribution metabolism elimination parameters. Therefore, formulation strategies need to consider various scenarios in order to be effective. Compound 1 is a potent phosphoinositide 3-kinase delta inhibitor with poor intrinsic solubility and 2 basic pKas. It was dosed as a suspension in dogs and found to have mediocre oral bioavailability with high variability. It was hypothesized that this variability was caused by their stomach pH variability. Pharmacokinetic modeling suggested that the issue could be improved with particle size reduction. Meanwhile, it was found that although the Madin-Darby canine kidney permeability was reasonable, Madin-Darby canine kidney transfected with human MDR1 gene (MDCK-MDR1) suggested that Compound 1 is an efflux transporter substrate. Findings were integrated into the design for in vivo studies in dogs. Data obtained from those studies allowed us to quickly narrow down the formulation approaches.     

Exploring a Kinetic Model Approach in Biopharmaceutics: Estimating the Fraction Absorbed of Orally Administered Drugs in Humans

Increasing costs of research and development in the pharmaceutical industry has necessitated a growing interest in the early prediction of human pharmacokinetics of drug candidates. Of growing interest is the need to understand oral absorption, the most common route of small molecule drug administration. The fraction of dose absorbed (%Fa) is considered a critical yet challenging parameter to predict. A kinetic model has been developed and tested to provide an early prediction of the fraction dose absorbed in humans. Unlike the traditional plug-flow model, this model assumes first-order kinetics to estimate the amount of drug present in the stomach and small intestine as a function of time and calculates the amount of drug released and absorbed during the transit. Other variables can be included in calculation as a function of time to better mimic the physiological condition with this approach. Absorption efficiency is assigned along with %Fa to give a quantitative estimate of the limiting factor for oral absorption. The model was tested with literature and in-house compounds. It was found that this model gives a good prediction of human %Fa with a correction coefficient (R²) of 0.8 and greater between predicted and reported %Fa for all compounds.     

Rapid identification of invasive fungal species using sensitive universal primers-based PCR and restriction endonuclease digestions coupled with high-resolution melting analysis

BackgoundConventional diagnosis of invasive fungal disease from blood cultures is often notoriously delayed and inadequately sensitive. We aimed to develop a universal primers-based polymerase chain reaction (PCR) assay and restriction fragment length polymorphisms (RFLP) for rapid identification of invasive fungal disease (IFD).MethodsWe evaluated 16 clinical fungal species using a combination of PCR assays with 3 different restriction endonucleases targeting various internal transcribed spacer (ITS) regions and high resolution melting analysis (HRMA). Serial samples from 75 patients suspected to have IFD were analyzed for clinical verification.ResultsWe have designed a universal PCR capable of amplifying a portion of the 18S rRNA gene of 16 clinically important fungal species. The restriction patterns of most PCR products generated by EcoRI or double digested by ClaI and AvaI were different, except Aspergillus niger and Aspergillus flavus had a similar pattern, and Aspergillus fumigatus and Aspergillus terreus had a similar pattern. All these species had a unique melting curve shape using the HRMA. Both HRMA and universal PCR had adequate sensitivity, and all sixteen reference fungal species can be clearly distinguished by the universal PCR-RFLP-HRMA assay. With a reference library of 176 clinically relevant fungal strains, and 75 clinical samples from patients with suspicious IFD were tested, our assay identified 100% and 61.1% of isolates from the reference library and clinical samples, respectively.ConclusionsUniversal PCR and RFLP coupled with HRMA could be a highly discriminative and useful molecular diagnostic that could enhance the current diagnostic, treatment, and surveillance methods of invasive fungal disease.