The Experts below are selected from a list of 1263 Experts worldwide ranked by ideXlab platform
Danielle Dhouailly - One of the best experts on this subject based on the ideXlab platform.
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retinoic acid and mouse skin morphogenesis i expression pattern of retinoic acid receptor genes during hair vibrissa follicle plantar and nasal gland development
Journal of Investigative Dermatology, 1994Co-Authors: Jean P Viallet, Danielle DhouaillyAbstract:Abstract The spatial and temporal expression of the nuclear retinoic acid receptors alpha, beta, and gamma (RAR-α, β, and γ) was compared by in situ hybridization during hair vibrissa follicle and nasal and plantar eccrine gland morphogenesis in mouse embryo. The RAR-α and RAR-γ transcripts are abundant in the dermal papilla cells of the hair vibrissa when these cells elicit epidermal hair placode (12.5-d embryos) and hair follicle (13.5-d embryos) formation. Both these transcripts are also abundant in the dermal cells of the plantar foot pad at the initiation stage (17.5-d embryos) of Glandular morphogenesis. In epidermal cells, the distribution of RAR-γ transcripts increases in parallel with hair vibrissa follicle and sweat gland differentiation, and thus may be part of the epidermal response to the dermal instructions. The RAR-β signal is barely above control level during both hair vibrissa and plantar gland morphogenesis. By contrast, during nasal gland formation (12.5- to 15.5-d embryos), the RAR-β signal reaches a high level in mesenchymal cells, whereas the RAR-α transcripts are present in both epithelial and mesenchymal cells. These results suggest a role for RAR-α and RAR-γ in the epidermal-dermal interactions that lead to hair follicle and plantar gland morphogenesis, whereas the nasal gland development implies RAR-α and RAR-β gene expression. This should be correlated with the expression of the RAR-β gene that was previously shown to be linked to the RA-induced Glandular Metaplasia of hair vibrissa follicles.
Richard Poulsom - One of the best experts on this subject based on the ideXlab platform.
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duodenal content reflux into the esophagus leads to expression of cdx2 and muc2 in areas of squamous epithelium in rats
Journal of Gastrointestinal Surgery, 2007Co-Authors: Manuel Pera, Miguel Pera, Maria J Brito, Luis Grande, Carmen De Bolos, Antonio Palacin, Antonio Cardesa, Richard PoulsomAbstract:The molecular events responsible for the transdifferentiation of epithelial cells of the esophagus to a columnar cell type are not well understood. Cdx2 has been detected in Barrett’s esophagus, so we sought evidence of Cdx2 expression during the process of transdifferentiation of the esophageal squamous epithelium into a Glandular phenotype. Thirty-two rats underwent an esophago-jejunostomy to produce esophagitis of 20, 25, 30, or 35 weeks of duration. The spectrum of esophageal lesions induced by chronic reflux was examined for expression of Cdx2 and Muc2 by immunohistochemistry. Five animals developed Glandular Metaplasia and adenosquamous carcinoma, two developed only Glandular Metaplasia, and two had adenosquamous carcinoma alone. Nuclear Cdx2 expression was detected in 57% (four of seven) and 43% (three of seven) of foci of Glandular Metaplasia and adenosquamous carcinomas, respectively. Cdx2 staining was detectable in some squamous and some mucus secreting cells. Perinuclear and perivacuolar staining of Muc2 was detected focally in 71% (five of seven) and 57% (four of seven) of areas with Glandular Metaplasia and adenosquamous carcinoma, respectively. We show that duodenal-content reflux into the esophagus switches on the expression of Cdx2 protein in esophageal keratinocytic cells, promoting a mucinous transdifferentiation process with secretion of intestinal mucin Muc2.
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duodenal content reflux esophagitis induces the development of Glandular Metaplasia and adenosquamous carcinoma in rats
Carcinogenesis, 2000Co-Authors: Miguel Pera, Maria J Brito, Manuel Pera, Richard Poulsom, Emilio Riera, Luis Grande, Andrew M Hanby, N A WrightAbstract:Recent studies have demonstrated that refluxed duodenal contents cause esophageal carcinoma in rats without exposure to carcinogens. The histopathological spectrum of these carcinomas includes squamous-cell carcinoma, adenocarcinoma and adenosquamous carcinoma. Pure adenocarcinomas are thought to arise in areas of columnar Metaplasia adjacent to the anastomosis, similar to Barrett's esophagus in humans. In contrast, the histogenesis of adenosquamous carcinomas is unclear. The purpose here was to investigate the pathogenesis of esophageal adenosquamous carcinomas in a time-course experiment of chronic duodenal-content reflux without carcinogen. Forty-two 8-week-old male Sprague-Dawley rats were divided into seven groups and exposed to duodenal-content esophageal reflux during 10, 15, 20, 25, 30, 35 and 40 weeks, respectively. All animals underwent an esophagojejunostomy with gastric preservation in order to produce chronic esophagitis. The rats received a standard diet without addition of carcinogens. An increasing incidence of Glandular Metaplasia and carcinoma was observed over the time course, starting at 20 weeks. After 40 weeks of reflux, multiple foci of Glandular Metaplasia and adenosquamous carcinoma were found in 83 and 50% of the animals, respectively. Most of the carcinomas occurred in the middle and proximal esophagus and had a dual pattern of differentiation, Glandular and squamous. These findings confirm that duodenal content reflux alone has a carcinogenic effect. We propose that chronic duodenal reflux induces the development of metaplastic cells with Glandular differentiation from the stem cells of squamous epithelium, and that Glandular metaplastic foci are the morphological element from which tumors with a dual pattern of differentiation arise.
Miguel Pera - One of the best experts on this subject based on the ideXlab platform.
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duodenal content reflux into the esophagus leads to expression of cdx2 and muc2 in areas of squamous epithelium in rats
Journal of Gastrointestinal Surgery, 2007Co-Authors: Manuel Pera, Miguel Pera, Maria J Brito, Luis Grande, Carmen De Bolos, Antonio Palacin, Antonio Cardesa, Richard PoulsomAbstract:The molecular events responsible for the transdifferentiation of epithelial cells of the esophagus to a columnar cell type are not well understood. Cdx2 has been detected in Barrett’s esophagus, so we sought evidence of Cdx2 expression during the process of transdifferentiation of the esophageal squamous epithelium into a Glandular phenotype. Thirty-two rats underwent an esophago-jejunostomy to produce esophagitis of 20, 25, 30, or 35 weeks of duration. The spectrum of esophageal lesions induced by chronic reflux was examined for expression of Cdx2 and Muc2 by immunohistochemistry. Five animals developed Glandular Metaplasia and adenosquamous carcinoma, two developed only Glandular Metaplasia, and two had adenosquamous carcinoma alone. Nuclear Cdx2 expression was detected in 57% (four of seven) and 43% (three of seven) of foci of Glandular Metaplasia and adenosquamous carcinomas, respectively. Cdx2 staining was detectable in some squamous and some mucus secreting cells. Perinuclear and perivacuolar staining of Muc2 was detected focally in 71% (five of seven) and 57% (four of seven) of areas with Glandular Metaplasia and adenosquamous carcinoma, respectively. We show that duodenal-content reflux into the esophagus switches on the expression of Cdx2 protein in esophageal keratinocytic cells, promoting a mucinous transdifferentiation process with secretion of intestinal mucin Muc2.
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duodenal content reflux esophagitis induces the development of Glandular Metaplasia and adenosquamous carcinoma in rats
Carcinogenesis, 2000Co-Authors: Miguel Pera, Maria J Brito, Manuel Pera, Richard Poulsom, Emilio Riera, Luis Grande, Andrew M Hanby, N A WrightAbstract:Recent studies have demonstrated that refluxed duodenal contents cause esophageal carcinoma in rats without exposure to carcinogens. The histopathological spectrum of these carcinomas includes squamous-cell carcinoma, adenocarcinoma and adenosquamous carcinoma. Pure adenocarcinomas are thought to arise in areas of columnar Metaplasia adjacent to the anastomosis, similar to Barrett's esophagus in humans. In contrast, the histogenesis of adenosquamous carcinomas is unclear. The purpose here was to investigate the pathogenesis of esophageal adenosquamous carcinomas in a time-course experiment of chronic duodenal-content reflux without carcinogen. Forty-two 8-week-old male Sprague-Dawley rats were divided into seven groups and exposed to duodenal-content esophageal reflux during 10, 15, 20, 25, 30, 35 and 40 weeks, respectively. All animals underwent an esophagojejunostomy with gastric preservation in order to produce chronic esophagitis. The rats received a standard diet without addition of carcinogens. An increasing incidence of Glandular Metaplasia and carcinoma was observed over the time course, starting at 20 weeks. After 40 weeks of reflux, multiple foci of Glandular Metaplasia and adenosquamous carcinoma were found in 83 and 50% of the animals, respectively. Most of the carcinomas occurred in the middle and proximal esophagus and had a dual pattern of differentiation, Glandular and squamous. These findings confirm that duodenal content reflux alone has a carcinogenic effect. We propose that chronic duodenal reflux induces the development of metaplastic cells with Glandular differentiation from the stem cells of squamous epithelium, and that Glandular metaplastic foci are the morphological element from which tumors with a dual pattern of differentiation arise.
Manuel Pera - One of the best experts on this subject based on the ideXlab platform.
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duodenal content reflux into the esophagus leads to expression of cdx2 and muc2 in areas of squamous epithelium in rats
Journal of Gastrointestinal Surgery, 2007Co-Authors: Manuel Pera, Miguel Pera, Maria J Brito, Luis Grande, Carmen De Bolos, Antonio Palacin, Antonio Cardesa, Richard PoulsomAbstract:The molecular events responsible for the transdifferentiation of epithelial cells of the esophagus to a columnar cell type are not well understood. Cdx2 has been detected in Barrett’s esophagus, so we sought evidence of Cdx2 expression during the process of transdifferentiation of the esophageal squamous epithelium into a Glandular phenotype. Thirty-two rats underwent an esophago-jejunostomy to produce esophagitis of 20, 25, 30, or 35 weeks of duration. The spectrum of esophageal lesions induced by chronic reflux was examined for expression of Cdx2 and Muc2 by immunohistochemistry. Five animals developed Glandular Metaplasia and adenosquamous carcinoma, two developed only Glandular Metaplasia, and two had adenosquamous carcinoma alone. Nuclear Cdx2 expression was detected in 57% (four of seven) and 43% (three of seven) of foci of Glandular Metaplasia and adenosquamous carcinomas, respectively. Cdx2 staining was detectable in some squamous and some mucus secreting cells. Perinuclear and perivacuolar staining of Muc2 was detected focally in 71% (five of seven) and 57% (four of seven) of areas with Glandular Metaplasia and adenosquamous carcinoma, respectively. We show that duodenal-content reflux into the esophagus switches on the expression of Cdx2 protein in esophageal keratinocytic cells, promoting a mucinous transdifferentiation process with secretion of intestinal mucin Muc2.
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duodenal content reflux esophagitis induces the development of Glandular Metaplasia and adenosquamous carcinoma in rats
Carcinogenesis, 2000Co-Authors: Miguel Pera, Maria J Brito, Manuel Pera, Richard Poulsom, Emilio Riera, Luis Grande, Andrew M Hanby, N A WrightAbstract:Recent studies have demonstrated that refluxed duodenal contents cause esophageal carcinoma in rats without exposure to carcinogens. The histopathological spectrum of these carcinomas includes squamous-cell carcinoma, adenocarcinoma and adenosquamous carcinoma. Pure adenocarcinomas are thought to arise in areas of columnar Metaplasia adjacent to the anastomosis, similar to Barrett's esophagus in humans. In contrast, the histogenesis of adenosquamous carcinomas is unclear. The purpose here was to investigate the pathogenesis of esophageal adenosquamous carcinomas in a time-course experiment of chronic duodenal-content reflux without carcinogen. Forty-two 8-week-old male Sprague-Dawley rats were divided into seven groups and exposed to duodenal-content esophageal reflux during 10, 15, 20, 25, 30, 35 and 40 weeks, respectively. All animals underwent an esophagojejunostomy with gastric preservation in order to produce chronic esophagitis. The rats received a standard diet without addition of carcinogens. An increasing incidence of Glandular Metaplasia and carcinoma was observed over the time course, starting at 20 weeks. After 40 weeks of reflux, multiple foci of Glandular Metaplasia and adenosquamous carcinoma were found in 83 and 50% of the animals, respectively. Most of the carcinomas occurred in the middle and proximal esophagus and had a dual pattern of differentiation, Glandular and squamous. These findings confirm that duodenal content reflux alone has a carcinogenic effect. We propose that chronic duodenal reflux induces the development of metaplastic cells with Glandular differentiation from the stem cells of squamous epithelium, and that Glandular metaplastic foci are the morphological element from which tumors with a dual pattern of differentiation arise.
Jean P Viallet - One of the best experts on this subject based on the ideXlab platform.
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retinoic acid and mouse skin morphogenesis i expression pattern of retinoic acid receptor genes during hair vibrissa follicle plantar and nasal gland development
Journal of Investigative Dermatology, 1994Co-Authors: Jean P Viallet, Danielle DhouaillyAbstract:Abstract The spatial and temporal expression of the nuclear retinoic acid receptors alpha, beta, and gamma (RAR-α, β, and γ) was compared by in situ hybridization during hair vibrissa follicle and nasal and plantar eccrine gland morphogenesis in mouse embryo. The RAR-α and RAR-γ transcripts are abundant in the dermal papilla cells of the hair vibrissa when these cells elicit epidermal hair placode (12.5-d embryos) and hair follicle (13.5-d embryos) formation. Both these transcripts are also abundant in the dermal cells of the plantar foot pad at the initiation stage (17.5-d embryos) of Glandular morphogenesis. In epidermal cells, the distribution of RAR-γ transcripts increases in parallel with hair vibrissa follicle and sweat gland differentiation, and thus may be part of the epidermal response to the dermal instructions. The RAR-β signal is barely above control level during both hair vibrissa and plantar gland morphogenesis. By contrast, during nasal gland formation (12.5- to 15.5-d embryos), the RAR-β signal reaches a high level in mesenchymal cells, whereas the RAR-α transcripts are present in both epithelial and mesenchymal cells. These results suggest a role for RAR-α and RAR-γ in the epidermal-dermal interactions that lead to hair follicle and plantar gland morphogenesis, whereas the nasal gland development implies RAR-α and RAR-β gene expression. This should be correlated with the expression of the RAR-β gene that was previously shown to be linked to the RA-induced Glandular Metaplasia of hair vibrissa follicles.