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Introduction: Collection of tumor samples is not always feasible in non-small cell lung cancer (NSCLC) patients, and circulating free DNA (cfDNA) extracted from blood represents a viable alternative. Different sensitive platforms have been developed for genetic cfDNA testing, some of which are already in clinical use. However, several difficulties remain, particularly the lack of standardization of these methodologies. Areas covered: Here, the authors present a review of the literature to update the applicability of cfDNA for diagnosis and monitoring of NSCLC patients. Expert commentary: Detection of somatic alterations in cfDNA is already in use in clinical practice and provides valuable information for patient management. Monitoring baseline alterations and emergence of resistance mutations is one of the most important clinical applications and can be used to non-invasively track disease evolution. Today, different technologies are available for cfDNA analysis, including whole-genome or exome sequencing and targeted methods that focus on a selection of genes of interest in a specific disease. In the case of Next Generation Sequencing (NGS) approaches, in depth coverage of candidate mutation loci can be achieved by selecting a limited number of targeted genes.

In this study we describe the most relevant morphological features of the microglial reaction that takes place in the arcuate nucleus (AN) after neurotoxic injury induced by a single subcutaneous injection of monosodium glutamate (MSG) in neonatal rats. The time course of the reaction was evaluated by lectinhistochemistry. Microglial/macrophagic cells were labelled with the lectin obtained from Lycopersicon esculentum and with B4 isolectin from Griffonia simplicifolia. The microglial response was also studied by ultrastructural observations. 'The histochemical study revealed the presence of few reactive microglial cells at 6 h post-injection. These cells were intensely stained and had a globular morphology but contained no neuronal debris inside them when observed under the electron microscope. At 12 h post-injection, the number of microglial cells had increased and, at the same time, intense phagocytic activity was observed ultrastructurally. The microglial reaction peaked at 24 and 36 h post-injection, when the number of microglial/ macrophagic cells was maximum, although the ultrastructural observations showed that at 36 h the amount of debris ingested by macrophages was decreased with respect to animals sacrificed at 24 h. Finally, at 4 days after neurotoxic injection the number and morphology of microglial cells were similar to those observed in the control rats. The ultrastructural study also revealed the existence of microglial cell mitosis in the territory of the AN together with a strong increase in the number of supraependymal cells resembling macrophages in the third ventricle during the lesion. Our data demonstrate that activated microglial cells initially extend throughout the damaged territory, but from 24-36 h onwards they are especially patent in the ventrolateral portions of the AN.

We have performed an ultrastructural and quantitative study of granular filarnentous bodies (GFBs) present in the cytoplasm of some arcuate nucleus neurons of rats of both sexes castrated at one month of age and sacrificed one or three months later, as well as untreated and sham-operated animals of the same ages. GFBs appear as round or ovoid cytoplasmic inclusions of granular-filamentous texture and generally lack a limiting membrane; their sizes vary from 0.7 to 2.8 p (average 1.7 m). GFBs are present more frequently in the perikarya, but they also occur in dendrites. In rats of both sexes castrated at one month of age and sacrificed three months later a noticeable finding was the presence of some giant GFBs, whose major axis could reach up to 6 p. The nomenclature, the origin and the possible significance and function of GFBs are discussed.

The morphological features of the ependymal surface and supraependymal elements of the fourth ventricle of the rat were examined by scanning electron microscopy (SEM) and by the transmission electron rnicroscopy (TEM). The results confirm the following aspects: 1) The presence of supraependymal elements and microvilli in the ependymal territories, including the sites where the cilia completely cover the ependymal surface; 2) The existence of cilia with oval or sphencal thickenings together with supraependymal bulbs similar in size to those of the larger ciliary swellings; 3) Identification of the long supraependymal fibres with intermittent fusiform dilations observed under the SEM with the neme fibres seen under the TEM; 4) The existence of intraventricular axodendritic synapses.

An electron-microscopic study was carried out on the median eminence of cats during post-natal development. From the moment of birth (observations performed 12 hours later) Herring bodies were seen in the fibrillary layer of the median eminence. At 45 days after birth, myelinated nerve fibres could be observed, some of them containing neurosecretory granules. The number of myelinated fibres in the median eminence increased with age and at 90 days some Herring bodies appeared surrounded by myelin sheaths; these mainly contained neurosecretory granules and a few mitochondria.

Lingual papillae of wild boar and pig were studied by means of scanning electron microscopy (SEM). Vallate papillae appear with the typical circumvallate morphology. Their papillary bodies show conical or fungiform-like and spicule-like pseudopapillae in both animals. Taste pores were seen in the papillary grooves. Microplicae or pits are visible at high magnification. In pig and wild boar similar foliate papillae were observed. Pig has less but wider leaves than wild boar. Taste pores on papillary walls were viewed. At high magnification microplicae were seen. Morphologically, fungiform papillae correspond with their denomination. Taste pores open onto the upper surface and they are easily identifiable by SEM. The rostral and lateral regions contain the major number of fungiform papillae. The lateral papillae of wild boar and pig show a high number of pores per papilla. These regions must be considered important in taste sensitivity. Lateral papillae in both animals could provide a source of taste buds for study. In both animals the fungiform papillary epithelium showed a pitted appearance as a consequence of keratinization by food environmental stress. The filiform papillae can be both simple and compound (with body and hairs). Large conical papillae are located caudally and curved in the same direction. Filiform and conical papillae have a function in food mastication, handling and deglutition.

Many advanced cases of cancer show central nervous system, pleural, or peritoneal involvement. In this study, we prospectively analyzed if cerebrospinal fluid (CSF), pleural effusion (PE), and/or ascites (ASC) can be used to detect driver mutations and guide treatment decisions. We collected 42 CSF, PE, and ASC samples from advanced non‐small‐cell lung cancer and melanoma patients. Cell‐free DNA (cfDNA) was purified and driver mutations analyzed and quantified by PNA‐Q‐PCR or next‐generation sequencing. All 42 fluid samples were evaluable; clinically relevant mutations were detected in 41 (97.6%). Twenty‐three fluids had paired blood samples, 22 were mutation positive in fluid but only 14 in blood, and the abundance of the mutant alleles was significantly higher in fluids. Of the 34 fluids obtained at progression to different therapies, EGFR resistance mutations were detected in nine and ALK acquired mutations in two. The results of testing of CSF, PE, and ASC were used to guide treatment decisions, such as initiation of osimertinib treatment or selection of specific ALK tyrosine–kinase inhibitors. In conclusion, fluids close to metastatic sites are superior to blood for the detection of relevant mutations and can offer valuable clinical information, particularly in patients progressing to targeted therapies., Many advanced cases of cancer show central nervous system, pleural, or peritoneal involvement. Here, we present the results of prospective genetic testing of 42 cerebrospinal fluids, pleural effusions, and ascites, and we show that these fluids, which are closer to metastatic sites, are superior to plasma (P) for the detection of clinically relevant mutations.