CT and MRI findings of mucin-containing tumors and pseudotumors of the thorax: pictorial review

Bronchial mucus has tomodensitometric features and MR signal intensity similar to that of water. However, chronic entrapped mucus collections, due to water reabsorption and higher protein content, can have CT attenuation values higher than 20 and reaching even 130 HU. Higher protein concentration also causes a sensible reduction in T1 relaxation time. The demonstration of mucus within a mediastinal, bronchial or pulmonary lesion is an important diagnostic clue permitting remarkable shortening of the list of differential diagnoses. This article illustrates the CT and MR findings allowing correct characterization of the mucus-containing lesions of mediastinum, bronchi, and lung.     

Wollastonite Fibers in Vitro Generate Reactive Oxygen Species Able to Lyse Erythrocytes and Activate the Complement Alternate Pathway

Wollastonite fibers were tested in vitro for their ability toproduce reactive oxygen species (ROS) with two different systems:a cell-free reactive mixture containing deoxyribose and a polymorphonuclearleukocyte suspension. After adding the fibers, we measured thethiobarbituric acid-reactive substances pduced by deoxyribosedegradation and luminol-enhanced chemiluminescence, respectively.Compared with asbestos, wollastonite fibers produced higherROS levels both in the PMN suspensions and in the cell-freereactive mixtures. A large amount of these ROS were not hydroxylradicals. Indeed we obtained remarkable differences in ROS generationbetween unground and ground wollastonite fibers and negativeresults with fibers modified with ferric chloride and dithionite.In addition, ROS generation was partially inhibited (by 46–54%)in the reactions performed in the presence of 1,3-dimethyl-2-thiourea(DMTU), a strong hydroxyl radical scavenger. Wollastonite fiberswere also analyzed for their ability to lyse erythrocytes andactivate complement. Hemolytic potency was about twice thatof chrysotile and half that of crocidolite. The levels of complementactivation (via the alternate pathway) were about four-fifthsof those measured in zyrnosan-activated plasma (a typical stimulusused to activate the alternate pathway), equal to those obtainedwith crocidolite, and two-thirds of those found with chrysotile.The addition of DMTU markedly reduced both these activities.Since asbestos fiber toxicity is mainly due to hydroxyl radicalgeneration, our results indicate that wollastonite fibers areprobably less toxic than asbestos fibers.     

Choroid plexus tumors. An immunocytochemical study with particular reference to the coexpression of intermediate filament proteins.

Sixteen choroid plexus tumors (CPTs) have been investigated for the localization of different immunocytochemical markers of epithelial and nonepithelial nature, namely, simple epithelial-type cytokeratins, vimentin, glial fibrillary acidic protein (GFAP), a panepithelial antigen defined by the lu-5 monoclonal antibody (lu-5 antigen), S-100 protein, and epithelial membrane antigen (EMA). Intermediate filament proteins have been identified in paraffin sections of 14 of 16 cases (87.5%). In all these tumors, cytokeratins and vimentin were constantly coexpressed by the neoplastic cells, in a manner similar to that of the cells lining normal choroid plexus. In 7 of these 14 cases, in addition to cytokeratins and vimentin, the neoplastic cells were shown to coexpress GFAP, which is not synthesized by their normal cell counterpart. The appearance of GFAP immunoreactivity in CPTs might be related to an ependymal differentiation of the neoplastic cells, because normal ependyma and ependymomas constantly coexpress GFAP and vimentin. The simultaneous expression of three distinct intermediate filament proteins by the same neoplastic cells is an exceedingly rare phenomenon, which has never been reported by double labeling technique in neoplasms of the central nervous system. Despite the complex antigenic profile of the CPT, which includes immunoreactivity for lu-5 antigen, S-100 protein, and EMA in most of the cases, positivity for three different epithelial markers indicates that these tumors have an epithelial nature. Moreover, the immunocytochemical typing of CPT with the panel of antibodies used in the current investigation allows differentiation from other primary and metastatic central nervous system tumors.     

Clinical and etiopathogenetic evaluation of a rare cause of spontaneous pneumoperitoneum and volvulus of the ileum: pneumatosis cystoides intestinalis. Report of a case

A case of pneumatosis cystoides intestinalis with pneumoperitoneum and volvulus complications is reported. After careful examination of the literature, etiopathogenic, pathophysiological and clinical features of the disease are analyzed by the Authors, also in the light of recent findings. Major diagnostic and therapeutic implications are discussed regarding possible complications requiring a different therapeutic approach. PCI, a lesion which can be benign, primary or secondary in many conditions, may be characterized by the presence of spontaneous pneumoperitoneum which only requires a careful, but not aggressive therapy, unlike other complications such as volvulus or intestinal occlusion which, instead, require timely surgical action. The Authors describing the therapy adopted, highlight the positive role of the enteral nutrition (NE) and oxygen therapy in the clinical course of the disease.     

Death from coronary air embolism during percutaneous transluminal coronary angioplasty

A patient undergoing percutaneous transluminal angioplasty of a critical proximal stenosis of his anterior descending coronary artery died as a result of coronary air embolism from a defective dilatation catheter. The probable mechanism responsible for this lethal complication is discussed. Simple precautions are described that will prevent its future occurrence.     

Prion protein potentiates acetylcholine release at the neuromuscular junction.

Cellular prion protein (PrP(c)), the normal isoform of the pathogenic peptide (PrP(sc)) responsible of the transmissible spongiform encephalopaties (TSEs), is present in many neural tissues, including neuromuscular junctions (NMJ). To analyze if this protein could influence the synaptic transmission, we performed an electrophysiological approach to study the effect of cellular prion protein on a mammalian neuromuscular junction. The loose patch clamp (LPC) technique enables the study of the whole preparation including the pre- and the post-synaptic domains. In a mouse phrenic-diaphragm preparation, nanomolar concentrations of cellular prion protein were able to induce a very striking potentiation of the acetylcholine (ACh) release. The effect was mainly pre-synaptic with an increase of the amplitude of the miniature end-plate currents, probably calcium dependent. Moreover, an apparent facilitation of the synaptic transmission was noted. The results clearly indicate that cellular prion protein may play a key role in the function of the neuromuscular junction.     

Embryologic and acquired anomalies of the inferior vena cava with recurrent deep vein thrombosis

Anomalies of the inferior vena cava theoretically favor venous stasis and development of deep vein thrombosis. We report two cases of repeated deep vein thrombosis in patients with embryologic and acquired anomalies of the inferior vena cava, in which hypercoagulability syndrome was ruled out.