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991.
992.

Aim

Pseudomyxoma peritonei (PMP) is an uncommon malignancy, generally originating from a ruptured epithelial tumour of the appendix. Despite successful cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), some patients recur. Currently there are no guidelines on the methods, frequency and intensity of follow-up.

Methods

Between 1994 and 2016, 1070 patients underwent surgery for a perforated epithelial tumour of the appendix, predominantly with PMP. Overall (OS) and Disease Free Survival (DFS) were documented by annual CT scanning and evaluated according to the Kaplan-Meier method. The influence of histological differentiation was investigated.

Results

Overall, 775/1070 (72%) had complete cytoreductive surgery (CCRS) and HIPEC. Histological classification was low grade PMP in 615 (79.4%), high grade PMP in 134 (17.3%) and adenocarcinoma in 26 (3.4%). DFS and OS were significantly worse for high grade disease, with the steepest decline for both in the first three years. DFS curves, for low as well as high grade PMP, levelled off at year 6 at approximately 60% and 20% respectively. Thereafter there were few recurrences in either group.

Conclusion

Annual CT of the abdomen and pelvis in the first six years appears to be adequate follow-up for low grade PMP. In high grade PMP, additional imaging of the chest and more frequent surveillance, during the first three years postoperatively, may detect recurrent disease earlier. From year 6 on, reduced frequency of follow-up is proposed, independent of the histology. This long-term follow-up in a large number of patients gives insight into tumour behavior after CCRS and HIPEC for PMP and guides intensity of surveillance.  相似文献   
993.
994.
LANGUAGE="EN">Summary. The image quality of a radiograph is determined by the local contrast, spatial resolution, latitude and the image noise. The goal of digital processing is to improve the visualisation of pathology by optimising these physical parameters. Processing parameters need to be chosen correctly in order to overcome the inverse relationship between contrast and latitude while producing images that retain a conventional appearance. Unsharp mask filtering (UMF) is a simple technique for improving image quality. This technique, however, suffers from serious drawbacks, such as the suppression of pathologic lesions or artifacts that may simulate pathology. Manufacturers have developed different approaches in order to overcome problems and artifacts derived from this technique.  相似文献   
995.
996.
This work investigates a set of ECG data compression schemes to compare their performances in compressing and preparing ECG signals for automatic cardiac arrhythmia classification. These schemes are based on transform methods such as fast Fourier transform (FFT), discrete cosine transform (DCT), wavelet transform (WT), and their combinations. Each specific transform is applied to a pre-selected data segment from the MIT-BIH database and then compression is performed in the new domain. These transformation methods are known as an important class of ECG compression techniques. The WT has been shown as the most efficient method for further improvement. A compression ratio of 7.98 to 1 has been achieved with a percent of root mean square difference (PRD) of 0.25%, indicating that the wavelet compression technique offers the best performance over the other evaluated methods.  相似文献   
997.
We studied 80 cases of primary thymic neuroendocrine carcinomas. Most patients had symptoms; approximately one third were asymptomatic. All cases were treated by surgical excision. The tumors were divided according to histopathologic features into low- (n = 29), intermediate- (n = 36), and high-grade (n = 15) types. The tumors displayed a variegated histologic appearance and unusual cytologic features. Some cases showed transition from low to high grade within the same tumor mass. Mitotic activity ranged from fewer than 3 to more than 10 mitotic figures per 10 high-power fields, and most tumors displayed marked cellular atypia and areas of necrosis. In 73 patients, the tumor was confined to the anterior mediastinum. Positive immunohistochemical reaction was observed using antibodies for CAM 5.2 low-molecular-weight cytokeratins, broad-spectrum keratin, chromogranin, synaptophysin, and Leu-7. The clinical follow-up obtained in 50 patients correlated well with tumor differentiation. Therefore, the behavior of these tumors seems to correlate with histologic grade, which seems directly proportional to degree of differentiation. We propose replacing the term thymic carcinoid with thymic neuroendocrine carcinoma, which better reflects the aggressive biologic behavior of these tumors in the mediastinal location.  相似文献   
998.
999.
The gene encoding folylpolyglutamyl synthetase (FPGS) was assigned to mouse chromosome 2 by complementation mapping. Chinese hamster ovary cells (AuxBl) deficient in FPGS, and consequently auxotrophic for glycine, adenosine, and thymidine (gat?), were employed as recipients in microcell-mediated chromosome transfer experiments. Mouse chromosomes derived from diploid embryo fibroblasts were introduced into hamster AuxBl cells, and gat+ microcell hybrids were selected in medium lacking adenosine and thymidine. Mouse chromosome 2 was the only donor chromosome whose presence correlated with expression of FPGS activity. Furthermore, every gat+ hybrid clone expressed murine AK-1, a marker previously assigned to chromosome 2. Eight of 20 clones analyzed retained deletion chromosomes derived from mouse chromosome 2. These clones were used to localize murine Fpgs and Ak-1 to a region of this chromosome, namely 2(cen→C1).  相似文献   
1000.
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