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Biomedical subjects

M O'Neil

Publications and source records attributed to M O'Neil.

15 recordsLinked to original sources
PubMed1994

The option to withdraw from chronic dialysis treatment.

This multidisciplinary discussion focuses on the case of a young diabetic woman who chose to stop chronic hemodialysis during a long and complicated illness. The perspective presented here include an academic lawyer's view of such medical decisions; a hospital chaplain's view of the religious framework for end-of-life situations; a clinical psychiatrist's considerations when consulted to evaluate patients in such straits; a transplant nurse's view of the opportunities for personal interaction that such clinical situations present; and a renal social worker's approach to chronic illness, advance directives, and death in the dialysis patient population. The discussion is intended to address objectively some important issues associated with death in this population, aimed at increasing our willingness to discuss these issues more openly with patients and with our colleagues.

Adult↗
PubMed1994

Age-related changes in oxygen saturation over the first year of life: a longitudinal study.

Stability of oxygen saturation depends on maturation and function of individual components of the respiratory system. The aim of this study was to record and analyse comprehensive oxygen saturation data in a longitudinal study over the first year of life. Detailed sleep studies were performed on 15 normal infants eight times in the first year of life. The accrued oxygen saturation data were analysed on a computerized oximetry data analysis system. Results show the mean sleep saturation levels trending upwards and stabilizing by 185 days. There was an inverse curvilinear relationship between mean age and median desaturation time and the median number of desaturations at < or = 95, < or = 92 and < or = 90% saturation. The mean cumulative desaturation time < or = 90% in the first 4 months was 11.08 min (range 2.5-36.57 min). This study demonstrates monotonic patterns of increasing saturation and decreasing number and time of desaturations < or = 95% and < or = 90% but a random pattern of desaturations < or = 85% occurs across the first 6 months of life. Cumulative desaturation times over the first 4 months of life were high and could be important to the development of maturity of the respiratory system. After 6 months, all indices of saturation and desaturation point to a stable and mature respiratory system.

Aging↗
PubMed1990

Coagulation abnormalities in chronic peritoneal dialysis.

To determine whether children treated with chronic peritoneal dialysis have a hypercoagulable state, various coagulation and fibrinolytic factor concentrations or activities were measured in 17 children undergoing chronic peritoneal dialysis. The patients had significantly increased activities of factors VII and VIII, and increased concentrations of von Willebrand factor (vWF), fibrinogen, factor XIIIA and factor XIIIS compared to reference values (P less than 0.001 in each case). The activated partial thromboplastin time was prolonged (P less than 0.001) and the thrombin clotting time was decreased (P less than 0.05) in these children. The prothrombin time and activities of factors XII, XI, IX, X, V and II were not significantly different from control values. Protein C concentrations were similar to normal, but antithrombin III concentrations were increased (P less than 0.05). Within the fibrinolytic pathway, decreased concentrations of plasminogen were found (P less than 0.001) and the concentrations of alpha-2-antiplasmin were increased (P less than 0.001). The plasma albumin concentration was below 33 g/l in 13 of the 17 children. The duration of treatment with peritoneal dialysis was directly correlated with vWF concentrations (P less than 0.001) and inversely correlated with factor VII concentrations (P less than 0.01). Of these patients 2 have since had clinical thrombotic episodes. The coagulation abnormalities found may have a role in the occurrence of thrombosis complicating renal transplantation.

Adolescent↗
PubMed1990

Management of foreign-body bronchial obstruction using endoscopic laser therapy.

A case is presented in which the Nd:YAG laser obviated the need for a major thoracic procedure. A 7-year-old boy presented with an 18-month history of persistent nonproductive cough, preceded by a choking spell while eating pistachio nuts. High-grade left mainstem bronchial obstruction was caused by friable granulation tissue secondary to an underlying foreign body. By advancing a laser fiber through the working channel of a 5-mm Storz ventilating bronchoscope, the granulation tissue was vaporized, showing an irregular piece of pistachio nut shell embedded within the bronchial wall. After retrieval of the foreign body, bronchial patency was restored. Recovery was complete and uneventful. The bronchoscopic laser permits the delivery of precise and effective treatment to lesions within confined areas, and has a useful role in the management of some central airway lesions in children.

Airway Obstruction↗
PubMed1989

Schizophrenia and the perception of emotions. How accurately do schizophrenics judge the emotional states of others?

Audiovisual tapes of emotional situations were shown to 34 schizophrenics and 15 controls who were asked to rate the emotional content of the scenes using an adjective check-list. The schizophrenic patients failed to detect the dominant character of the scenes, and perceived the opposite emotions to those perceived by the controls. Such deviant responses were not related to paranoid symptoms, flattened affect, formal thought disorder, general level of morbidity, or duration of in-patient stay.

Adult↗
PubMed1987

Murine cytomegalovirus infection of reaggregate cultures of fetal mouse brain.

We used cultures of reaggregate embryonic mouse brain cells to study murine cytomegalovirus (MCMV) infection of neural tissues. After 21 to 28 days in culture, aggregates were infected with MCMV and studied sequentially for 14 days using virus assay, electron microscopy and indirect immunofluorescence. Infectious virus could be recovered from aggregate cultures beginning three days after infection, and peak virus titers were observed on day 7 in aggregate tissues and on day 14 in culture fluids. By transmission electron microscopy, intranuclear viral nucleocapsids were identified in neural cells at the periphery of the aggregates on day 3. Infection then spread centripetally into aggregate tissues so that by day 14 the majority of neural cells contained intranuclear inclusions, numerous nucleocapsids, and mature virus particles. Virion production in neural cells was the result of a sequence of events that included budding of nucleocapsids from the nucleus and envelopment of cytoplasmic virus particles by membranes of the Golgi apparatus. These studies indicate that MCMV infection of murine brain aggregate cultures is a potentially useful in vitro system for the study of CMV infections of neural tissue.

Animals↗
PubMed1983

Clinical aspects of non-Hodgkin's lymphomas presenting with discordant histologic subtypes.

From July 1971 to December 1980, 323 cases of non-Hodgkin's lymphoma were randomized into prospective clinical trials at Stanford University Medical Center. Analysis of these cases revealed 30 patients (9.3% of the total) with disease of different histologic subtypes at separate anatomic sites (discordant lymphomas). On further analysis, 16 of these patients (4.8% of the total) were found to have disease of different histological and prognostic types. Recommendation is made that initial therapy be directed at the poor-prognosis component of these tumors. Relapses of both favorable prognostic types and unfavorable histologic types were seen, and further biopsy at the time of relapse is recommended in these cases.

Adult↗
PubMed1979

Effect of protein depletion and repletion on liver structures, nitrogen content and serum proteins.

The data presented in this paper demonstrate that a liver which has been severely damaged by protein malnutrition can be restored to normal composition, anatomy and functional capability by central venous feeding. An atypical serum protein electrophoretic pattern characterizes protein malnutrition. TPN repletion restores all of the protein fractions back to normal except for the gamma globulin levels. Liver nitrogen is a very sensitive index of both protein malnutrition and TPN repletion. The liver is dramatically effected by protein malnutrition and its return toward normal can be achieved by TPN support as demonstrated in this paper.

Animals↗
PubMed1977

Cardiac monitoring.

Explore the source record for details and available documents.

Electrocardiography↗
PubMedDate not supplied

Evaluating and validating very large knowledge-based systems.

Most knowledge-based systems for use in medicine have been developed in response to specific problems such as the diagnosis of abdominal or chest pain in an accident and emergency department, or the diagnosis and treatment of meningitis. There is a role for a general decision support system capable of answering queries about any aspect of medicine, particularly in primary care. However, evaluating such a knowledge base requires more elaborate methodology than a simple iterative test and refine cycle. At the design stage an adequate knowledge base structure is required to allow focused modification of the knowledge base when errors are discovered. During the prolonged evaluation cycle the partially formed knowledge base must be tested with such techniques as validation checks for consistency and completeness and examination of characteristics of problem-solving procedures. Finally a variety of criteria that represent the performance, robustness, flexibility, predictability, validity, coverage, relevance and congruity of the knowledge base are needed for a full description of the system's worth. Two case studies from the Oxford System of Medicine project are provided as examples of this philosophy: validating specific medical facts and comparing two methods for aggregating reasoning for and against a decision option.

Artificial Intelligence↗
PubMedDate not supplied

Cholinergic actions of metrizamide.

In a study of the possible mechanisms of the clinical side effects of metrizamide, it was applied to several in vitro model preparations. It was shown that, although high metrizamide concentrations are without noticeable effect on many basic neuronal functions, metrizamide does interfere with cholinergic mechanisms. At concentrations equivalent to, or significantly lower than, those probably achieved during clinical procedures, metrizamide is both an inhibitor of the enzyme acetylcholinesterase and an antagonist of cholinergic transmission. These data suggest the possibility that some of the side effects resulting from clinical procedures employing metrizamide may be explained by its actions on cholinergic synapses.

Acetylcholine↗