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Different Pathogenesis (different + pathogenesis)

Distribution by Scientific Domains
Medical Sciences75%

Selected Abstracts

Flat adenoma in colon: Two decades of debate

JOURNAL OF DIGESTIVE DISEASES, Issue 4 2010
Patrick CP LAU
The existence of flat adenomas in the colon is well recognized. Whether they represent a distinct disease with a pathogenetic pathway different from that of the classical adenoma-carcinoma sequence in colorectal tumorigenesis and have higher malignant potential remains a matter of debate. To review the epidemiology, clinical features, detection and management of flat and depressed (non-polypoid) colonic neoplasm, we performed a thorough literature review on studies focusing on the prevalence, histological features, genetics, detection and treatment of flat and depressed (non-polypoid) colonic neoplasm. A high percentage of severe dysplasia in flat colonic adenomas has not been consistently demonstrated. Their malignant potential appears to be size-dependent. Flat adenomas are found to have a lower incidence of major genetic abnormalities involved in the classical adenoma-carcinoma sequence and that has raised suspicions that they may have a different pathogenesis. The depressed type of colorectal carcinoma is uncommon but shows more aggressive behavior. More advanced colonoscopic techniques, such as chromoendoscopy, may enhance the detection of small and inconspicuous colonic neoplastic lesions that lack a protruding configuration. It is essential for endoscopists to appreciate the existence and clinical significance of flat and depressed colonic lesions as an important variant of colonic neoplasms so that the goal of reducing colorectal carcinoma incidence by polypectomy can be better achieved. [source]

Clinicopathological features of gastric mucosa-associated lymphoid tissue lymphoma: A comparison with diffuse large B-cell lymphoma without a mucosa-associated lymphoid tissue lymphoma component

JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 7 2001
Toru Hiyama
Abstract Background and Aims: The aim of this study was to clinicopathologically distinguish the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma without a MALT lymphoma component (DLL). Methods: We investigated clinicopathological features of these gastric lymphomas including age, sex ratio, tumor location and depth, macroscopic appearance, and infection with Helicobacter pylori of these gastric lymphomas and hepatitis viruses in 24 patients with gastric low-grade MALT lymphoma, 10 patients with high-grade MALT lymphoma, and 19 patients with DLL. The frequency of H. pylori infection in lymphoma patients was compared with that in age- and sex-matched control subjects. Results: There was a predominance of females with MALT lymphoma (male to female ratio, 8/16 for low-grade MALT lymphomas and 1/9 for high-grade MALT lymphomas), and there was a predominance of males with DLL (male to female ratio, 13/6); the ratios differed significantly (P < 0.05). Ninety-two percent of low-grade MALT lymphomas and 80% of high-grade MALT lymphomas were confined to the mucosal and submucosal layers, but lymphoma cells invaded the muscular layer or more deeply in 74% of DLL. Helicobacter pylori infection occurred significantly more often in patients with low-grade MALT lymphoma than in age- and sex-matched controls (96 vs 67%, P < 0.01). Conversely, the frequency of H. pylori infection in DLL patients did not differ from that in controls. Conclusions: These data suggest that H. pylori infection may be associated with the development of gastric MALT lymphoma, but not DLL, and that MALT lymphoma and DLL may have a different pathogenesis. [source]

Pseudoacne of the Nasal Crease: A New Entity?

PEDIATRIC DERMATOLOGY, Issue 4 2004
Kimberly A. Risma M.D., Ph.D.
Milia were also noted in the nasal crease, but there was no evidence of acne vulgaris. The duration of symptoms was 4 months to 2 years, and lesions ranged from inflamed red papules, which were treated with topical antiinflammatory medications, to scarred white papules requiring excision. Histologic evaluation of two lesions revealed keratin granulomas that were likely derived from ruptured, inflamed milia. Due to its similarity in appearance to acne vulgaris, but different pathogenesis and clinical course, we suggest naming this newly described entity "pseudoacne of the nasal crease." [source]

Aberrant expression of glycosylation in juvenile gastrointestinal stromal tumors

PROTEOMICS - CLINICAL APPLICATIONS, Issue 9 2008
Tsuyoshi Takahashi
Abstract Most adult gastrointestinal stromal tumors (GIST) are thought to be caused by activating mutations in the KIT or PDGFRA gene. However, many juvenile GIST lack either mutation and are considered to develop with a different pathogenesis. To investigate the molecular characteristics of juvenile GIST, we analyzed the proteome difference in phosphorylated protein between adult and juvenile GIST. Eleven GIST samples (seven adult cases and four juvenile cases lacking either mutation) were analyzed by using immunostaining and LC-MS/MS. Comparative analysis of tyrosine-phosphorylated protein levels showed that juvenile GIST possessed phosphorylated KIT in spite of lacking mutation in the KIT gene. Moreover, downstream signals of KIT were also activated as in adult GIST. Although, SDS-PAGE gels showed that there was a difference of each KIT bands between adult and juvenile GIST, they became the same after removal of N-glycans or sialic acids. Moreover, one of the most typical enzymes, ST6Gal1, which transfers Neu5Ac residues in ,2-6 linkage to Gal ,1-4GlcNAc units on N-glycans, is significantly less expressed in juvenile GIST. This suggests that the difference in KIT is generated by post-translational modification and may play a role in the progression of juvenile GIST. [source]