Tumor progression and metastasis

The heterogeneity of cells capable of metastasation has proved to be the greatest obstacle to successful treatment or to prevention of metastatic diseases. This variety appears to be attributable to processes of selection. Cytobiological investigations which are helpful in casting some light at selective mechanisms of metastasation may, perhaps, make substantive contributions to cancer therapy.     

Disordered vergence control in dyslexic children.

By means of a synoptophore vergence eye movements were recorded in dyslexic and normal children while they were attempting to track small targets moving in simulated depth. Of the dyslexic children 64% were unable to make proper vergence movements when macular sized fusion targets (2 1/2 degrees) were employed, but their vergence control was better for larger (7 degrees) targets. The normal readers and the remaining dyslexics showed normal vergence responses for both large and small moving fusion stimuli. The results suggest that many dyslexics suffer a disorder of visuomotor control and perception for stimuli falling on the macula; this may explain their characteristic visual problems when reading. Hence recording vergence eye movement responses to small moving fusion stimuli may be useful in the investigation and treatment of children with reading difficulties.     

Apatite Determination and Distribution in an Early Stage of Gallbladder Calcification

This study is concerned with the nature and distribution of mineral in the gallbladder of a patient with chronic cholecystitis. Light and electron microscopic imaging revealed the mineral to be in the epithelial cells of the mucosa and fibroblasts of the submucosa. In the epithelial cells at the early stages of deposition, mineral was located in the nuclei and throughout the cytoplasm in association with interdigitating cell processes and apical microvilli but was absent in mitochondria. Elemental and electron diffraction analyses indicated the mineral inclusions to be apatite in nature.     

Musculo-fibrous anomaly in Barrett's mucosa with dysplasia

We investigated the histological alterations occurring in the muscularis mucosae, the lamina propria mucosae, and the submucosa in areas adjacent to invasive adenocarcinoma in 32 resected esophagi with Barrett's mucosa. In 26 of the 32 specimens, we observed a thickening of the muscularis mucosae, with overgrowth of the muscle fibers into the lamina propria mucosae. In other areas, collagen-rich fibrotic tissue replaced the muscularis mucosae, the lamina propria mucosae, and even the submucosa. In 31 of the 32 specimens, we noted cystic dilatations of the esophageal glands. Normal esophageal glands and cystically dilated glands with dysplastic lining were often surrounded, compressed, and deformed by the fibrotic tissue. The compression of the glandular outlets by the collagen-rich tissue or by proliferating dysplastic cells appeared to be the two main factors in the histogenesis of these cysts. This may result in difficulty in differentiating, in biopsy specimens, between normal and dysplastic esophageal glands "trapped" in the collagen-rich fibrotic tissue and true invasive adenocarcinoma in the Barrett's mucosa.     

Understanding general practice: a conceptual framework developed from case studies in the UK NHS

BACKGROUND: General practice in the UK is undergoing a period of rapid and profound change. Traditionally, research into the effects of change on general practice has tended to regard GPs as individuals or as members of a professional group. To understand the impact of change, general practices should also be considered as organisations. AIM: To use the organisational studies literature to build a conceptual framework of general practice organisations, and to test and develop this empirically using case studies of change in practice. This study used the implementation of National Service Frameworks (NSFs) and the new General Medical Services (GMS) contract as incidents of change. DESIGN OF STUDY: In-depth, qualitative case studies. The design was iterative: each case study was followed by a review of the theoretical ideas. The final conceptual framework was the result of the dynamic interplay between theory and empirical evidence. SETTING: Five general practices in England, selected using purposeful sampling. METHOD: Semi-structured interviews with all clinical and managerial personnel in each practice, participant and nonparticipant observation, and examination of documents. RESULTS: A conceptual framework was developed that can be used to understand how and why practices respond to change. This framework enabled understanding of observed reactions to the introduction of NSFs and the new GMS contract. Important factors for generating responses to change included the story that the practice members told about their practice, beliefs about what counted as legitimate work, the role played by the manager, and previous experiences of change. CONCLUSION: Viewing general practices as small organisations has generated insights into factors that influence responses to change. Change tends to occur from the bottom up and is determined by beliefs about organisational reality. The conceptual framework suggests some questions that can be asked of practices to explain this internal reality.