Post-COVID-19 tomographic abnormalities.

BACKGROUND: The prevalence of persistent respiratory symptoms tends to be low in patients with a longer recovery time after COVID-19. However, some patients may present persistent pulmonary abnormalities.OBJECTIVE: To evaluate the prevalence of tomographic abnormalities 90 days after symptom onset in patients with COVID-19 and compare two chest high-resolution computed tomography (HRCT) analysis techniques.METHODS: A multicentre study of patients hospitalised with COVID-19 having oxygen saturation <93% on room air at hospital admission were evaluated using pulmonary function and HRCT scans 90 days after symptom onset. The images were evaluated by two thoracic radiologists, and were assessed using software that automatically quantified the extent of pulmonary abnormalities.RESULTS: Of the 91 patients included, 81% had at least one pulmonary lobe with abnormalities 90 days after discharge (84% were identified using the automated algorithm). Ground-glass opacities (76%) and parenchymal bands (65%) were the predominant abnormalities. Both chest HRCT technical assessments presented high sensitivity (95.9%) and positive predictive value (92%), with a statistically significant correlation at baseline (R = 0.80) and after 90 days (R = 0.36).CONCLUSION: The prevalence of pulmonary abnormalities on chest HRCT 90 days after symptom onset due to COVID-19 was high; both technical assessments can be used to analyse the images.

A selective retinoid X receptor agonist bexarotene (LGD1069, targretin) inhibits angiogenesis and metastasis in solid tumours.

The present study determined the influence of a retinoid X receptor agonist bexarotene on angiogenesis and metastasis in solid tumours. In the experimental lung metastasis xenograft models, treatment with bexarotene inhibited the development of the lung tumour nodule formation compared to control. In vivo angiogenesis assay utilising gelfoam sponges, bexarotene reduced angiogenesis in sponges containing vascular endothelial growth factor, epidermal growth factor and basic fibroblast growth factor to various extent. To determine the basis of these observations, human breast and non-small-cell lung cancer cells were subjected to migration and invasion assays in the presence of bexarotene. Our data showed that bexarotene decrease migration and invasiveness of tumour cells in a dose-dependent manner. Furthermore, bexarotene inhibited angiogenesis by directly inhibiting human umbilical vein endothelial cell growth and indirectly inhibiting tumour cell-mediated migration of human umbilical vein endothelial cells through Matrigel matrix. Analysis of tumour-conditioned medium indicated that bexarotene decreased the secretion of angiogenic factors and matrix metalloproteinases and increased the tissue inhibitor of matrix metalloproteinases. The ability of bexarotene to inhibit angiogenesis and metastasis was dependent on activation of its heterodimerisation partner peroxisome proliferator-activated receptor gamma. Collectively, our results suggest a role of bexarotene in treatment of angiogenesis and metastasis in solid tumours.

Stent Scraping for Histology: An Alternative Method for Obtaining Tissue to Rule out Neoplasia.

Despite improvement in diagnostic modalities, confirmation of a histologic diagnosis of cancer of the biliary tree and pancreas remains elusive. Attempts to collect positive cytology specimens from vigorous brushings or washings obtained at endoscopy or percutaneously are often unsuccessful. In our unit, we have increased the yield by obtaining tissue scraped from prostheses that have been previously placed in either the bile duct or the pancreatic duct. The stents are first flushed with saline to collect cytology specimens, after which, they are bisected and scraped, and these contents are prepared in a manner similar to that used to prepare biopsy samples. Twelve of 16 scraped samples, 9 bile duct and 3 pancreas, were positive for adenocarcinoma. The cytology specimens were positive in only 4 of the 12. We recommend this method of sampling from material contained within prostheses as an adjunct when previous brushings, washings, or biopsies are negative.

Spectral optical-density measurements of small particles and breast tissues.

The optical density of breast tissues without blood is found to be relatively constant from 320 to 800 nm, indicating a relatively independent scattering cross section over this wavelength region.

A comparative study of DNA ploidy in 115 fresh-frozen breast carcinomas by image analysis versus flow cytometry.

BACKGROUND: Qualitative and quantitative analysis of cellular DNA content may be clinically useful in the prognostic evaluation of certain types of malignant tumors, including breast carcinoma. Flow cytometric (FCM) analysis has been the most frequently used procedure for DNA analysis, but it requires a reasonably large tissue sample. Computer-based image analysis (IA) now allows imprint, cytospin, and needle aspiration smear preparations and other small tissue samples to be used. METHODS: To resolve concern about the diagnostic efficacy of small tissue samples in the use of IA, the authors performed a comparative study of FCM analysis and IA using 115 fresh-frozen breast carcinomas. Feulgen-stained imprint preparations for IA and single-cell suspensions from the same fresh-frozen tissue for FCM analysis were used, and the respective histograms were compared. RESULTS: The results were concordant in 90.4% (104 of 115) of the cases, but 11 specimens yielded discordant data. IA provided histograms with a somewhat lower resolution and a relatively high coefficient of variation for the G0/G1 peak, thus rendering occasional tumors, which were near-diploid aneuploid by FCM analysis (four cases), not amenable to diagnosis by aneuploid characterization. In three additional cases, FCM analysis showed aneuploid hyperdiploid (two cases) and multiploid (one case) histograms, but IA only demonstrated a diploid peak. Conversely, in four other cases, aneuploid peaks were recognized only by IA. CONCLUSIONS: Computerized IA has significant advantages over FCM analysis, including lower cost, the ability to analyze very small specimens, the capability of detecting rare high ploidy cells, the capacity to classify cellular populations according to specific morphologic type, and the fact that no destructive enzyme or chemical digestion is required for specimen preparation, thereby preserving the integrity of fragile cells.

Raman, fluorescence, and time-resolved light scattering as optical diagnostic techniques to separate diseased and normal biomedical media.

Studies of Raman scattering, fluorescence and time-resolved light scattering were conducted on cancer and normal biomedical media. Fourier transform Raman spectroscopic measurements were performed on human normal, benign and cancerous tissues from gynecological (GYN) tracts. A comparison of the intensity differences between various Raman modes as well as the number of Raman lines, enables one to distinguish normal GYN tissues from diseased tissues. Fluorescence spectroscopic measurements on human breast tissues show that the ratio of fluorescence intensity at 340 nm to that at 440 nm can be used to distinguish between cancerous and non-cancerous tissues. Separate studies on normal and cancerous breast cell lines show spectral differences. The measurements of back-scattered ultrafast laser pulses from human breast tissues show differences in the scattered pulse profiles for different tissues. These studies show that various optical techniques have the potential to be used in medical diagnostic applications.

Light sheds light on cancer--distinguishing malignant tumors from benign tissues and tumors.

Difference in fluorescence spectra from human malignant and benign tumors, benign and normal breast tissues were measured. Spectral histograms from 40 samples show the diagnostic possibilities of this optical technology. Fluorescence from model fluorophores (nucleotides, amino acids, and proteins) were used to speculate on the sources of marked features of the tissue fluorescence.

Prognostic factors in colon carcinoma: correlation of serum carcinoembryonic antigen level and tumor histopathology.

Preoperative serum CEA values showed prognostic usefulness and correlated with established histopathologic prognostic parameters. CEA levels provide an additional useful prognostic index of a complex immunopathologic process. The best prognostic appraisal of the individual patient can be achieved by a complete assessment of all participating factors.

Prognostic factors in colon carcinoma: correlation of serum carcinoembryonic antigen level and tumor histopathology.

The results of histopathologic study and the preoperative circulating carcinoembryonic antigen levels were correlated with each other and with the postoperative clinical course in 45 surgically treated patients with cancer of the colon. Histopathologic evaluation of the tumor included the depth of bowel wall involvement according to the Dukes classification, the histologic differentiation of cells on the basis of Broders' grades of malignancy, evidence of lymphocyte and plasma cell infiltration within and surrounding the primary tumor, and evidence of blood vessel, lymphatic, and perineural invasion. All these parameters, including the serum carcinoembryonic antigen level, had prognostic value. Low serum carcinoembryonic antigen levels in patients with colonic cancer suggested tumor localized within the bowel wall; the highest values were found in patients with tumors that had spread beyond the bowel wall. An inverse correlation was noted between the degree of tumor differentiation and carcinoembryonic antigen levels in the same patient. Carcinoembryonic antigen levels tended to be elevated when blood vessel, lymphatic, and perineural invasion was present. An inverse correlation was also noted between the preoperative carcinoembryonic antigen level and the degree of lymphocyte and plasma cell infiltration in the primary tumor. Round cell infiltration was interpreted as an indication of the host's immune response against the tumor. Thus, on the basis of clinical follow-up of the patients it is concluded that all morphologic parameters evaluated have prognostic value, that preoperative serum carcinoembryonic antigen levels have prognostic value, that all prognostic parameters correlate with each other appropriately, and that the combined parameters are more reliable than any single one alone.