Upper Two-thirds (upper + two-thirds)

Distribution by Scientific Domains


Selected Abstracts


Apoptosis, anoikis and their relevance to the pathobiology of colon cancer

PATHOLOGY INTERNATIONAL, Issue 4 2000
Minalini Shanmugathasan
The maintenance of a constant number of cells in an adult organism is a tightly regulated process. This is particularly important in organs where cells are in a constant rate of renewal during the entire lifespan. In these organs, cell number homeostasis is the direct consequence of a bal-ance between cell proliferation and apoptosis. The colonic epithelium is an example of such a site and the high prevalence of colon cancer makes the understanding of cell number homeostasis more important to define. Normal colonic epithelium is organized in crypts where cell proliferation, migration, differentiation and apoptosis are topographically organized in a linear fashion along the crypt axis. Normal colonic crypts are composed of stem cells at the base, a proliferation and a differentiation zone in the lower third of the crypt, a migration zone in the upper two-thirds, and the surface epithelium where senescent cells are eliminated by apoptosis. Globally, apoptosis can be defined as a normal process of cell suicide, critical for development and tissue homeostasis. Colonic epithelial cells migrate from the base of the crypt to the surface epithelium in 6,7 days. The normal architecture of the crypt is maintained by a balance between cell proliferation at the base and apoptosis at the top of the crypt and surface epithelium. [source]


Stem cell markers (cytokeratin 15, CD34 and nestin) in primary scarring and nonscarring alopecia

BRITISH JOURNAL OF DERMATOLOGY, Issue 3 2009
M.P. Hoang
Summary Background, Although the pathogenesis of most primary scarring alopecias is poorly understood, recent studies implicate the bulge region as a possible target. Objectives, To corroborate these results, we ascertained involvement of follicular bulge stem cells using a panel of antibodies that putatively targeted the same. Methods, Antibodies used included anticytokeratin (CK) 15, CD34 and nestin on vertical and horizontal tissue sections of 50 cases of scarring and 34 cases of nonscarring alopecia. Results, Comparing expression of these markers in scarring vs. nonscarring alopecia, CK15 was noted in the follicular bulge region in 23 of 43 (53%) vs. 27 of 27 (100%) cases and in the peripheral layer of the outer root sheath (ORS) (upper two-thirds of the follicle) in 50 of 50 (100%) vs. 34 of 34 (100%) cases; CD34 was noted in the peripheral layer of the ORS (below pilar muscle attachment) in 24 of 35 (69%) vs. 18 of 18 (100%) cases; and nestin was noted in the infundibular region in 18 of 46 (39%) vs. seven of 32 (22%) cases and in the inner aspect of the ORS (below pilar muscle attachment) in eight of 31 (26%) vs. 23 of 23 (100%) cases. Conclusions, Our findings of differential follicular localization of stem cells underscore follicular progenitor cell heterogeneity and suggest the target in scarring alopecia is not merely follicular bulge stem cells but involves stem cells in the inner and outer aspect of the ORS. Enhanced expression of nestin in the infundibular region in scarring alopecia indicates availability of an accessible, in vivo niche of potential utility as an autologous source of stem cells for therapeutic application. [source]


Epidemiological study of oesophageal and gastric cancer in south-east England,

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 9 2001
Mr H. M. Kocher
Background: This epidemiological study was carried out to establish the magnitude of the changing incidence of gastric and oesophageal cancer. Methods: Time-trend analyses of subsite-specific cancers of the oesophagus and stomach were performed using data from the Thames Cancer Registry database (1960,1996) for the South Thames Region. The changes in sex ratio and peak age of incidence are reported. Results: In the upper two-thirds of the oesophagus there was no significant change in the incidence rate, but the lower third of the oesophagus showed a marked rise for both sexes (average annual change +005 for men, +0009 for women). For the gastric cardia, the incidence in males increased (average annual change +0025), while in females it remained unchanged. Cancers of the oesophagogastric junction showed a clear increase for both sexes (average annual change +007 for men, +0009 for women). There were changes in the sex ratio and peak age of incidence for all subsite cancers for both sexes. Conclusion: Over a 37-year period the incidence of cancer of the oesophagogastric junction increased threefold, while the incidence of cancers of the other subsites of the stomach decreased. Further studies are needed to investigate the aetiology of these changes. 2001 British Journal of Surgery Society Ltd [source]


New classification of oesophageal and gastric carcinomas

BRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 3 2001
K. Dolan
Background: The current International Classification of Diseases (ICD)-O classification of carcinomas of the oesophagus and stomach causes epidemiological and clinical confusion, particularly the use of the term cardia and the overlapping subsites described in the stomach. This study compared the epidemiological and clinical features of each subtype and subsite of carcinoma of the oesophagus and stomach to assess requirements for a new classification of these carcinomas. Methods: Data were extracted with appropriate validity checks on all cases of oesophageal and gastric carcinoma identified throughout the period 1974,1993 by the Merseyside and Cheshire Cancer Registry, which covers a population of 25 million. Comparison of all identifiable epidemiological and clinical features of adenocarcinomas at four different subsites, namely the upper two-thirds of the oesophagus, the lower third of the oesophagus, cardia and subcardia of the stomach, was performed. Results: There were 5322 primary carcinomas of the oesophagus and 10 535 carcinomas of the stomach registered between 1974 and 1993. The incidence of adenocarcinoma of the lower oesophagus and cardia trebled in males and doubled in females, whereas adenocarcinoma of the subcardia region of the stomach declined in both sexes. The incidence of adenocarcinoma of the lower oesophagus and of the cardia was similar for median age at diagnosis, male: female ratio, percentage of patients who smoked, and survival; both were significantly different from values for carcinoma of the subcardia in these respects. Conclusion: These data suggest that there is considerable overlap between adenocarcinomas of the lower oesophagus and adenocarcinomas currently classified as of the cardia. The authors believe this is due to the group of carcinomas classified as cardia consisting mainly of carcinomas that traverse the gastro-oesophageal junction. These carcinomas were different in all studied parameters from carcinomas of the stomach and should be classified separately from gastric carcinomas. A new subsite classification of oesophageal and gastric carcinomas is proposed that includes the gastro-oesophageal junction as a subsite of the oesophagus and that simplifies the subsite classification of the stomach into proximal, distal and overlapping. 2001 British Journal of Surgery Society Ltd [source]