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Macroscopic Lesions (macroscopic + lesion)

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Medical Sciences	100%

Selected Abstracts

Experimental esophageal carcinogenesis: technical standardization and results

DISEASES OF THE ESOPHAGUS, Issue 4 2002
J. A. Sallet
SUMMARY., The aim of this research was to determine the occurrence of epidermoid carcinoma of the esophagus induced by diethylnitrosamine (DEN) in Wistar rats. DEN was administered (250,300 g) in drinking water (10 mg/kg body weight) to four groups of rats for 72 h/week, for a duration of 90, 120, 150, or 200 days (groups T90, T120, T150, and T200). Ten animals whose drinking water did not contain DEN constituted the control group. All rats were sacrificed and their esophaguses studied macro- and microscopically. The control group did not exhibit either carcinomas or preneoplasic lesions. The T120 and T200 groups presented, respectively, 47 and 58 in situ carcinomas; 1 and 20 submucosal carcinomas (P < 0.05); 4 and 17 microinvasive carcinomas (P < 0.05); 4 and 11 advanced carcinomas (P < 0.05); and 1 and 1 cases of benign hyperplasia. Pulmonary and liver carcinomas were also found in the T200 group. The majority of advanced macroscopic lesions in the T200 group were polypoid, exophytic, and not microscopically invasive in the esophageal wall. This research confirms the effectiveness of the DEN in bringing about carcinogenesis in the Wistar rat esophagus and also shows that the lesions are dosage dependent. [source]

Biopsy Strategies for Endoscopic Surveillance of Pre-malignant Gastric Lesions

HELICOBACTER, Issue 4 2010
Annemarie C. De Vries
Abstract Background:, Endoscopic surveillance of pre-malignant gastric lesions may add to gastric cancer prevention. However, the appropriate biopsy regimen for optimal detection of the most advanced lesions remains to be determined. Therefore, we evaluated the yield of endoscopic surveillance by standardized and targeted biopsy protocols. Materials and Methods:, In a prospective, multi-center study, patients with intestinal metaplasia (IM) or dysplasia (DYS) underwent a surveillance gastroscopy. Both targeted biopsies from macroscopic lesions and 12 non-targeted biopsies according to a standardized protocol (antrum, angulus, corpus, cardia) were obtained. Appropriate biopsy locations and the yield of targeted versus non-targeted biopsies were evaluated. Results:, In total, 112 patients with IM (n = 101), or low-grade (n = 5) and high-grade DYS (n = 6) were included. Diagnosis at surveillance endoscopy was atrophic gastritis (AG) in one, IM in 77, low-grade DYS in two, high-grade DYS in three, and gastric cancer in one patient. The angulus (40%), antrum (35%) and lesser curvature of the corpus (33%) showed the highest prevalence of pre-malignant conditions. Non-targeted biopsies from the lesser curvature had a significantly higher yield as compared to the greater curvature of the corpus in diagnosing AG and IM (p = .05 and p = .03). Patients with extensive intragastric IM, which was also present at the cardia were at high risk of a concurrent diagnosis of dysplasia or gastric cancer. High-grade DYS was detected in targeted biopsies only. Conclusions:, At surveillance endoscopies, both targeted and non-targeted biopsies are required for an appropriate diagnosis of (pre-)malignant gastric lesions. Non-targeted biopsies should be obtained in particular from the antrum, angulus and lesser curvature of the corpus. [source]

In vivo selective inhibition of mitogen-activated protein kinase kinase 1/2 in rabbit experimental osteoarthritis is associated with a reduction in the development of structural changes

ARTHRITIS & RHEUMATISM, Issue 6 2003
Jean-Pierre Pelletier
Objective The primary aim of this study was to investigate, using an experimental rabbit model of osteoarthritis (OA), the effect of a selective mitogen-activated protein kinase kinase 1/2 (MEK-1/2) inhibitor, PD 198306, on the development of structural changes. Additional aims were to assess the effects of the inhibitor on levels of phosphorylated extracellular signal,regulated kinase 1/2 (phospho,ERK-1/2) and matrix metalloproteinase 1 (MMP-1; collagenase 1) in OA chondrocytes. Methods After surgical sectioning of the anterior cruciate ligament of the right knee joint, rabbits with OA were separated into 3 experimental groups: oral treatment with placebo or with PD 198306 at a therapeutic concentration of 10 mg/kg/day or 30 mg/kg/day. Each treatment started immediately after surgery. The animals were killed 8 weeks after surgery. Macroscopic and histologic studies were performed on the cartilage and synovial membrane. The levels of phospho,ERK-1/2 and MMP-1 in OA cartilage chondrocytes were evaluated by immunohistochemistry. Normal, untreated rabbits were used as controls. Results OA rabbits treated with the highest dosage of MEK-1/2 inhibitor showed decreases in the surface area (size) of cartilage macroscopic lesions (P < 0.002) and in osteophyte width on the lateral condyles (P = 0.05). Histologically, the severity of synovial inflammation (villous hyperplasia) was also reduced (P < 0.02). In cartilage from placebo-treated OA rabbits, a significantly higher percentage of chondrocytes in the superficial layer stained positive for phospho,ERK-1/2 and MMP-1 compared with normal controls. Rabbits treated with the highest dosage of PD 198306 demonstrated a significant and dose-dependent reduction in the level of phospho,ERK-1/2 and a lower level of MMP-1. Conclusion This study demonstrates that, in vivo, PD 198306, a selective inhibitor of MEK-1/2, can partially decrease the development of some of the structural changes in experimental OA. This effect was associated with a reduction in the level of phospho,ERK-1/2 in OA chondrocytes, which probably explains the action of the drug. [source]

Major hepatectomy in patients with synchronous colorectal liver metastases: whether or not a contraindication to simultaneous colorectal and liver resection?

COLORECTAL DISEASE, Issue 3 2007
E. Jovine
Abstract Objective, Synchronous hepatic lesions account for 15,25% of newly diagnosed colorectal cancer and its optimal timing to surgery is not completely defined, but simultaneous colorectal and liver resection is recently gaining acceptance, at least in patients with a right colonic primary and liver metastases that need a minor hepatectomy to be fully resected. Method, From September 2002 to December 2004, 16 patients underwent simultaneous resection as treatment of synchronous colorectal liver resection; in 10 patients (62.5%) a major hepatectomy was performed. Results, The mean duration of intervention was 322.5 ± 59.5 min, operative mortality and morbidity rates was 0% and 25% respectively; the hospitalization was 14.4 (range 8,60) days on average. Mean follow-up was 14 months and actuarial survival was 76.5% at 1 year and 63.5% at 2 years. Conclusion, We concluded that simultaneous colonic and liver resection should be undertaken in selected patients with synchronous colorectal liver resection regardless of the extent of hepatectomy; major liver resection, in fact, seems capable of providing better oncological results, allowing resection of liver micrometastases that, in almost one-third of the patients, are located in the same liver lobe of macroscopic lesions, without increased morbidity rates. [source]