Tb3+-doped LaF3 nanocrystals for correlative cathodoluminescence electron microscopy imaging with nanometric resolution in focused ion beam-sectioned biological samples

Here, we report the use of rare earth element-doped nanocrystals as probes for correlative cathodoluminescence electron microscopy (CCLEM) bioimaging. This first experimental demonstration shows potential for the simultaneous acquisition of luminescence and electron microscopy images with nanometric resolution in focused ion beam cut biological samples.

Ultra-thin resin embedding method for scanning electron microscopy of individual cells on high and low aspect ratio 3D nanostructures

The preparation of biological cells for either scanning or transmission electron microscopy requires a complex process of fixation, dehydration and drying. Critical point drying is commonly used for samples investigated with a scanning electron beam, whereas resin-infiltration is typically used for transmission electron microscopy. Critical point drying may cause cracks at the cellular surface and a sponge-like morphology of nondistinguishable intracellular compartments. Resin-infiltrated biological samples result in a solid block of resin, which can be further processed by mechanical sectioning, however that does not allow a top view examination of small cell-cell and cell-surface contacts. Here, we propose a method for removing resin excess on biological samples before effective polymerization. In this way the cells result to be embedded in an ultra-thin layer of epoxy resin. This novel method highlights in contrast to standard methods the imaging of individual cells not only on nanostructured planar surfaces but also on topologically challenging substrates with high aspect ratio three-dimensional features by scanning electron microscopy.

Theranostic body fluid cleansing: rationally designed magnetic particles enable capturing and detection of bacterial pathogens

We show theoretical and experimental considerations on bacteria capturing and enrichment via magnetic separation enabling integrated diagnosis and treatment of blood stream infections.

[Cost-benefit of upper digestive endoscopy. Frequency of early gastric cancer and negative endoscopy in relation to indications]

The increasing demand for upper gastrointestinal endoscopies (184% from 1974 to 1985) led to a review of cases in an attempt to improve the cost-benefit ratio of this diagnostic procedure (E.G.C.). Two parameters were evaluated: the frequency of early gastric cancers and, on the other hand, the incidence of negative endoscopic findings with respect to indications. The increase in the number of endoscopies performed was not matched by an increased frequency of E.G.C. diagnosed: 8.9% in 1974-1979 and 7.5% in 1980-1985 with an E.G.C./endoscopy ratio of 1:218 and 1:415 respectively; in the second period the diagnostic accuracy of endoscopy was enhanced from 42.8% to 100%. The overall frequency of negative endoscopic findings on 500 patients undergoing endoscopy in 1985, was 40.4%. The greatest number of negative findings was observed in patients with non-ulcerous dyspepsia under 50 years of age and in those with ulcerous dyspepsia with prior duodenal ulcer; on the other hand, a significant prevalence of cancerous and precancerous lesions was observed in patients over 50 with non-ulcerous dyspepsia. The results of this study suggest that patients over 50 years with non-ulcerous dyspepsia should receive early endoscopic investigation, in those under 50 an initial therapeutic approach appears reasonable. In the patients with prior duodenal ulcer endoscopy is of limited value for the assessment of response to therapy.

[Thyroid nodular pathology: retrospective study of 917 surgical interventions]

A retrospective investigation of the surgical cases of seven hospitals in the Veneto region was made in order to assess the malignancy rate in thyroid nodular pathology, and the predictive value of scintiscanning with positive indicator.

[Early gastric cancer: a retrospective study of our cases (1974-1979)]

A retrospective analysis of 3052 gastroscopies made by our Digestive Endoscopy Department from 1974 to 1979 was carried out. 14 Early Gastric Cancers out of a total of 157 gastric carcinomas were diagnosed (8.9%), with an EGC: Gastroscopies ratio = 1:218. From the macroscopic point of view 8 were found to belong to type III, 5 to type II, and 1 to type I. The main location was the lesser curvature (angulus-antrum). With regard to the degree of infiltration, 2 were found to belong to stage 0a, 8 to stage 0b, and 5 to stage I. The endoscopic observation gave reason to suspect the presence of a malignant lesion in 6 of the 14 cases. The bioptic examination proved positive in 10 cases, while in 4 the diagnosis was made on the operatory piece. The importance of multiple bioptic samples is again confirmed. Cytology performed by brushing showed malignant tumoral cells in 4 cases, and again in 4 cases the radiological examination led to suspicion of degenerated gastric ulcer. 13 patients were subjected to surgery during which no metastases to the locoregional lymphonodes were found; the patients are all alive. We started gastric carcinoma screening by selecting the patients on the basis of a worksheet covering epidemiological, clinical, biohumoural and instrumental parameters, since the prognosis for the disease is directly proportional to the earliness of its diagnosis.