Fibroblast growth factor receptors in cancer: genetic alterations,diagnostics, therapeutic targets and mechanisms of resistance

Fibroblast growth factor receptors (FGFRs) are aberrantly activated through single-nucleotide variants, gene fusions and copy number amplifications in 5–10% of all human cancers, although this frequency increases to 10–30% in urothelial carcinoma and intrahepatic cholangiocarcinoma. We begin this review by highlighting the diversity of FGFR genomic alterations identified in human cancers and the current challenges associated with the development of clinical-grade molecular diagnostic tests to accurately detect these alterations in the tissue and blood of patients. The past decade has seen significant advancements in the development of FGFR-targeted therapies, which include selective, non-selective and covalent small-molecule inhibitors, as well as monoclonal antibodies against the receptors. We describe the expanding landscape of anti-FGFR therapies that are being assessed in early phase and randomised controlled clinical trials, such as erdafitinib and pemigatinib, which are approved by the Food and Drug Administration for the treatment of FGFR3-mutated urothelial carcinoma and FGFR2-fusion cholangiocarcinoma, respectively. However, despite initial sensitivity to FGFR inhibition, acquired drug resistance leading to cancer progression develops in most patients. This phenomenon underscores the need to clearly delineate tumour-intrinsic and tumour-extrinsic mechanisms of resistance to facilitate the development of second-generation FGFR inhibitors and novel treatment strategies beyond progression on targeted therapy.Subject terms: Cancer, Cancer     

Treatment of Tobacco Use in Preconception Care

Maternal and Child Health Journal -     

The Volk steady mount holder for the +90D lens

Since its introduction in early 1985, the Volk +90D lens has become a very popular auxiliary lens for biomicroscopic fundus evaluation. The Volk +90D lens provides a wide field of view which is accessible by simple scanning of the biomicroscope. The necessity to hand hold the lens, however, has not always provided enough stability, particularly for the novice user. This article describes a newly introduced holder for the Volk +90D lens which mounts on the base of the biomicroscope headrest providing rapid and stable lens placement. Use of this holder improves the technique of retinal examination and photography by stabilizing the image and by freeing both hands to operate the slit lamp biomicroscope. The enhanced stability afforded by this holder also gives the examiner the practical capability of viewing the posterior pole without mydriasis.     

The precision of positron emission tomography: theory and measurement

The limits of quantitation with positron emission tomography (PET) are examined with respect to the noise propagation resulting from radioactive decay and other sources of random error. Theoretical methods for evaluating the statistical error have been devised but seldom applied to experimental data obtained on human subjects. This paper extends the analysis in several ways: (1) A Monte Carlo method is described for tracking the propagation of statistical error through the analysis of in vivo measurements; (2) Experimental data, obtained in phantoms, validating the Monte Carlo method and other methods are presented; (3) A difference in activation paradigm, performed on regional CBF (rCBF) data from five human subjects, was analyzed on 1.6-cm diameter regions of interest to determine the mean fractional statistical error in PET tissue concentration and in rCBF before and after stereotactic transformation; and (4) A linear statistical model and calculations of the various statistical errors were used to estimate the magnitude of the subject-specific fluctuations under various conditions. In this specific example, the root mean squared (RMS) noise in flow measurements was about three times higher than the RMS noise in the concentration measurements. In addition, the total random error was almost equally partitioned between statistical error and random fluctuations due to all other sources.     

Coagulation screening before epidural analgesia in pre-eclampsia

A questionnaire survey of current practice at a small cross-section of obstetric units, covering 22% of all United Kingdom deliveries, revealed a marked lack of standard practice regarding requests for coagulation screens on pre-eclamptic patients who require epidural procedures. A retrospective audit was therefore carried out on 434 coagulation screens requested for pre-eclamptic patients in whom epidural analgesia might have been considered. Borderline abnormalities of coagulation were found in only 10 patients (2%). Platelet counts of less than 150 x 10(9)/litre were present in 28% of cases. 'Significant' thrombocytopenia (less than 100 x 10(9)/litre) and all coagulation abnormalities were only encountered in severe pre-eclampsia (diastolic blood pressure of greater than 110 mmHg and proteinuria of + + or greater). Furthermore, coagulation abnormality was always associated with a reduced platelet count (mean, 97 x 10(9)/litre). This study would therefore support anaesthetic practice which restricted any requests for coagulation testing to severe pre-eclamptic patients only. For these patients first line testing could be limited to a platelet count.     

Phosphoinositide hydrolysis linked 5-HT2 receptors in fibroblasts from choroid plexus

A serotonin (5-HT)-mediated phosphoinositide hydrolysis response was characterized in fibroblasts cultured from rabbit choroid plexus. 5-HT elicited a maximum 8-fold increase in [³H]inositol-phosphate ([³H]IP) formation, while the partial agonists, (+)-lysergic acid diethylamide and (−)-1-(4-bromo-2,5-dimethyoxyphenyl)-2-aminopropane caused 2- and 5-fold increases, respectively. Mianserin, ketanserin, and spiperone were equipotent at blocking the 5-HT-mediated response. Thus, agonist and antagonist profiles indicate interactions with 5-HT₂ receptors.     

Effects of neurosurgical titanium mesh on radiation dose

The purpose of this study was to determine the dosimetric impact of a neurosurgical titanium mesh in patients treated with 6- and 18-MV photon beams. The effects of a 0.4-mm-thick titanium mesh on the dose profile at 3 regions within a solid water phantom were measured using extended dose range-2 (EDR2) film for 6- and 18-MV photon beams. All measurements were performed with the titanium mesh placed at a depth of 1.5 cm in the phantom. Films were exposed immediately above the mesh, immediately below the mesh, and at a depth of 5 cm from the surface of the phantom. The films were scanned using a scanning densitometer. In the region directly above the titanium mesh, there was an increase in dose of 7.1% for 6-MV photons and 4.9% for 18-MV photons. Directly below the titanium mesh, there was an average decrease in dose of 1.5% for 6-MV photons and an increase of 1.0% for 18-MV photons. At 5-cm depth, for 6- and 18-MV photons, there was a decrease in dose of 2.2% and 0.6%, respectively. We concluded that for cranial irradiation with high-energy photons, the dosimetric impact of a 0.4-mm titanium mesh is small and does not require modification in treatment parameters.