OBJECTIVE: To assess the value of Pathfinder (CompuCyte, Cambridge, Massachusetts, U.S.A.) in improving adequacy and accuracy of screening and supporting quality control programs. STUDY DESIGN: The investigations were carried out on cervical cytologic smears only. Screening adequacy was assessed through the evaluation of percentage of slide coverage, percentage of overlapping and amount of elapsed time on smears screened with or without the Pathfinder by junior (426 cases) and senior (1,552 cases) screeners. Screening accuracy was investigated by comparing the performances of the same observer when reexamining, with the Pathfinder, a series of 1,051 cases already evaluated without the Pathfinder at least three months earlier. The review process was analyzed by both monitoring the elapsed time for relocation of manually or electronically marked cells (824 fields in 80 smears) and by comparing diagnostic discrepancies after the review of two series (74 + 74 cases) of randomly selected negative cases screened with or without Pathfinder. RESULTS: Pathfinder-assisted screening increased the number of cases with optimal slide coverage (> or = 90% of screenable area) and optimal overlapping (between 15% and 20%) by both junior (P < .00001 and P < .00001) and senior (P < .00001 and P < .0003) screeners. It also improved screening accuracy by decreasing the number of cases "unsatisfactory for evaluation" (P < .00001) (as a consequence of better coverage and overlapping) and the number of diagnostic discrepancies detected after review (P = .05). During the latter process, the time elapsed for relocation of electronically marked fields, as compared to manually marked ones, was greatly reduced (1 hour, 25 minutes saved for revision of 40 smears). CONCLUSION: In these preliminary studies, the Pathfinder was a useful tool for both education and diagnosis (screening and review) in a cytology laboratory.

Automation↗

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Coexpression of intermediate filaments in normal and neoplastic human tissues: a reappraisal.

The current view that coexpression of intermediate filaments (IFs) must be considered a bizarre and unpredictable phenomenon, which seriously jeopardizes the use of their localization in diagnostic applications, is critically reviewed in light of the evidence so far acquired by investigations in vivo and in vitro. A less dogmatic approach, which considers IF expression the result of a series of interactions between cells and their microenvironment instead of a function of their histogenesis, not only justifies the complex variety of coexpressions observed in normal and neoplastic tissues but also confirms the usefulness of IF expression in diagnostic applications and offers new opportunities for investigations, with special regard to immunoelectron microscopy.

Cytoskeleton↗

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Educational innovations in the medical faculty.

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Curriculum↗

PubMedDate not supplied

Ultrastructural localization of advanced glycation end products and beta2-microglobulin in dialysis amyloidosis.

BACKGROUND: beta2-microglobulin (beta2m) is considered to be the amyloidogenic precursor in dialysis-related amyloidosis (DRA, Abeta2M amyloidosis). beta2m modified with advanced glycation end products (AGE) may be an important factor in the pathogenesis of DRA. The presence of AGE in beta2m-positive amyloid deposits and surrounding macrophages has been demonstrated by immunohistochemical techniques in light microscopy. METHODS: In order to better define the localization of beta2m and AGE in amyloid deposits and in cells, carpal tunnel connective tissues obtained from surgical specimens in six patients with DRA were studied by immunohistochemistry and electron microscopy, using the avidine-biotine complex and immunogold staining procedures, respectively. A polyclonal rabbit anti-human beta2m and two monoclonal mouse anti-AGE antibodies [AG-1 anti-imidazolone and AG-10 anti-N(epsilon)-carboxymethyl-lysine] enabled us to label their respective antigens at the optical and ultrastructural level. RESULTS: with both techniques, extracellular amyloid deposits strongly reacted with anti-beta2m and anti-AGE antibodies, although the immunoreactivity of beta2m was more intense. Macrophage-like synovial cells (CD-68 positive) surrounding amyloid deposits were also immunoreactive for beta2m and AGE, which were detected in lysosomes and in intracellular fibrillar material. Anti-AGE reactivity was also evident in collagenous structures in the absence of beta2m or amyloid deposits, supporting the proposal that AGE modification of collagen might have pathogenic relevance in the development of DRA. CONCLUSIONS: The co-localization of AGE and beta2m, both intra- and extra-cellularly, in amyloid fibrils was confirmed by immunoelectron microscopy; however, the positivity of collagen to anti-AGE antibodies and a different pattern of intracellular localization suggest that molecules other than beta2m may also be modified by AGE and may be involved in the pathogenesis of DRA.

Amyloidosis↗

PubMedDate not supplied

Prophylaxis of fatal pulmonary embolism in general surgery using low-molecular weight heparin Cy 216: a multicentre, double-blind, randomized, controlled, clinical trial versus placebo (STEP). STEP-Study Group.

The effectiveness of low-molecular weight heparin CY 216 in the prophylaxis of fatal pulmonary embolism in patients undergoing general surgery was assessed in a multicentre, double-blind, randomized, clinical trial against placebo. A total of 4,498 patients aged over 40 undergoing general surgery were enrolled in the 18 centres which took part in the trial. Patients received a single daily subcutaneous injection of 7,500 anti-Xa units I.C. of CY 216 or placebo two hours before surgery, 12 hours after the initial injection and then daily for at least seven days. A post-mortem examination had to be carried out in every patient who died. The two groups of patients were well-matched for age, sex, type of disease, site and duration of operation as well as for incidence of risk factors which could predispose to the development of thromboembolism. Twenty-six deaths were recorded and validated: eight (0.36%) in the CY 216 group and 18 (0.80%) in the placebo group (p less than 0.05). At the post-mortem examination, carried out in 23 patients (88.5%), two deaths were found to be directly due to pulmonary embolism (0.09%) in the CY 216 group and four (0.18%) in the placebo group. Pulmonary embolism contributed to death in four other placebo-treated patients. Pulmonary or extrapulmonary thromboembolism was a significantly less frequent direct cause of death (p less than 0.05) in the CY 216 group (two pulmonary embolisms) than in the placebo group (four pulmonary embolisms, one acute myocardial infarction, one disseminated intravascular coagulation, two ischemic cerebral strokes).(ABSTRACT TRUNCATED AT 250 WORDS)

Double-Blind Method↗

PubMedDate not supplied

[Ultrastructural aspects of edema in experimental allergic encephalitis].

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Animals↗

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Depolarized expression of episialin (EMA, MUC1) in lung adenocarcinoma is associated with tumor progression.

Carcinoma cell detachment is an important step in tumor progression and metastasis. Episialin (EMA), if expressed throughout the entire cell surface, may inhibit cell-cell and cell-matrix adhesion. We investigated whether the cellular distribution of episialin in non-small cell lung cancer (NSCLC) is associated with tumor progression. We evaluated the expression of episialin by immunohistochemical staining, in surgical specimens from 122 adenocarcinomas and 99 squamous cell carcinomas. Episialin was present in most NSCLC, with a higher percentage of immunoreactive neoplastic cells in adenocarcinoma than in squamous cell carcinoma (p = 0.0001). In adenocarcinoma the depolarized pattern was significantly associated with nodal metastasis (p = 0.005) and with advanced stage (p = 0.007). In conclusion, nodal metastasis and advanced pathological stage in adenocarcinoma are associated with a depolarized cellular distribution of episialin, suggesting a possible involvement of the molecule in cancer metastasis.

Adenocarcinoma↗