Biomedical subjects
Publications and source records attributed to A Graham.
A case of pseudolymphoma of the breast presenting as an isolated tumor mass in the breast of a 56-year-old female is described. Recognition of this rare lesion is important in order to differentiate it from other malignant neoplasms.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Some problems common to many disciplines are briefly examined. One of the problems, that of an information overload, was recognized in medical education already twenty years ago; since then the situation has become much more acute. We have attempted to give a numerical value to the information content of a number of courses and these highlight the overload in the medical course.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
It is now held that in conditions where there is conflicting sensory information vision dominates touch. The present study was designed to place boundary conditions on the generality of the hypothesis by comparing the performance of tactually experienced subjects - potters - with university students on a form-perception task in which a square was optically distorted so as to appear rectangular. Subjects examined the square haptically and visually, and matched it by touch or vision. Although potters were more accurate than students when not permitted vision, tactual judgements of both were dominated by vision when they were presented with conflicting information. In a supplementary study longer, more active exploration and emphasis on the necessity of matching by touch had no differential effect. In a third study it was found that a range effect produced by the comparison stimuli could explain the lesser accuracy of the students when they were making haptic judgements. The generality of the hypothesis that vision dominates touch is strengthened by our failure to refute it.
A previous report described a cell isolate presumed to have arisen by accidental cocultivation (contamination) of the Chang 'liver' cell line and rheumatoid synovial cells. This cell isolate had the same glucose-6-phosphate dehydrogenase isoenzyme as the Chang cell and also some shared antigens. It clearly differed in its karyotype, its ability to grow in semisolid agar, and in the possession of bleb-like projections of the cytoplasmic membrane filled with collections of beaded or granular material. In addition, it had a novel antigen(s) not present in the Chang cell. As these properties might have been acquired from the synovial cells and because the bleb structures resembled those seen in some cell lines transformed by leucovirus the cell isolate has been further studied. Cytochemical methods at the light and electron microscope level showed that the granular material was polysaccharide in nature, probably glycogen. No evidence was found of the presence of a virus or a viral genome using a variety of techniques including attempted induction followed by 3H-uridine labelling of the cultures, and assay of the supernatant fluid from the culture for viral RNA-dependent DNA polymerase. In addition, cell extracts were not found to contain viral RNA-dependent DNA polymerase or RNA-dependent RNA polymerase. No rubella virus or leucovirus interspecies antigens were detected on the cell membranes.
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The amplification refractory mutation system (ARMS) has been applied to prenatal diagnosis and carrier detection of cystic fibrosis. The nucleotide sequence of both alleles of the PstI restriction fragment length polymorphism at the KM19 locus, which displays linkage disequilibrium with cystic fibrosis, has been determined. ARMS enables direct analysis of alleles of this polymorphism in DNA isolated from chorionic villus biopsy or white blood cells.
Pharyngeal arches are a prominent and critical feature of the developing vertebrate head. They constitute a series of bulges within which musculature and skeletal elements form; importantly, these tissues derive from different embryonic cell types [1]. Numerous studies have emphasised the role of the cranial neural crest, from which the skeletal components derive, in patterning the pharyngeal arches [2-4]. It has never been clear, however, whether all arch patterning is completely dependent on this cell type. Here, we show that pharyngeal arch formation is not coupled to the process of crest migration and, furthermore, that pharyngeal arches form, are regionalized and have a sense of identity even in the absence of the neural crest. Thus, vertebrate head morphogenesis can now be seen to be a more complex process than was previously believed and must result from an integration of both neural-crest-dependent and -independent patterning mechanisms. Our results also reflect the fact that the evolutionary origin of pharyngeal segmentation predates that of the neural crest, which is an exclusively vertebrate characteristic.
A case report involving an anesthesia adverse event that was received in the FDA database was used to demonstrate postmarket reporting of medical devices by the manufacturers and the FDA. Even common, everyday adverse events are evaluated and used to improve the safety and efficacy of medical products. Instructions for accessing the FDA MedWatch forms and coding manual are provided, and readers are referred to additional resources on the FDA website.
A muscularised pharynx, with skeletal support, serving the dual functions of feeding and respiration, is a fundamental vertebrate characteristic. Embryologically, the pharyngeal apparatus has its origin in a series of bulges that form on the lateral surface of the embryonic head, the pharyngeal arches, whose development is complex. These structures are composed of a number of disparate embryonic cell types: ectoderm, endoderm, neural crest and mesoderm, whose development must be coordinated to generate the functional adult apparatus. In the past, most studies have emphasised the role played by the neural crest, which generates the skeletal elements of the arches, in directing pharyngeal arch development, but it has also become apparent that the endoderm plays a prominent role in directing arch development. Neural crest cells are not required for arch formation, their regionalisation nor to some extent their sense of identity. Furthermore, the endoderm is the major site of expression of a number of important signalling molecules, and this tissue has been shown to be responsible for promoting the formation of particular components of the arches. Thus vertebrate pharyngeal morphogenesis can now be seen to be a more complex process than was previously believed, and must result from an integration of both neural crest and endodermal patterning mechanisms. Interestingly, this also mirrors the fact that the evolutionary origin of pharyngeal segmentation predates that of the neural crest, which is an exclusively vertebrate characteristic. As such, the evolution of the vertebrate pharynx is also likely to have resulted from an integration between these 2 patterning systems. Alterations in the interplay between neural crest and endodermal patterning are also likely to be responsible for the evolutionary that occurred to the pharyngeal region during subsequent vertebrate evolution.