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Biomedical subjects

J R Cox

Publications and source records attributed to J R Cox.

At least 19 recordsLinked to original sources
PubMed1992

Teleradiology via narrow-band integrated services digital network (N-ISDN) and Joint Photographic Experts Group (JPEG) image compression.

The importance of remote access to both radiological images and medical information has stimulated many demonstration projects that use a variety of telecommunications providers' offerings. Teleradiology, through modest cost channels, can achieve adequate response times using a combination of narrow-band integrated services digital network (N-ISDN) and data compression. A demonstration project, developed in collaboration with Southwestern Bell Technology Resources, Inc, uses the aggregate bandwidth of two B channels (achieving a rate of 120 kilobits per second) and a block-oriented discrete cosine transform compression/decompression implementation based on the Joint Photographic Experts Group Standard for Still Image Compression. System response measurements for an Inquiry and Display Station accessing the Mallinckrodt Institute of Radiology's Radiology Image and Information Management Testbed via the N-ISDN connection show response times to be within 20 seconds. Viewing applications have been shown at sites within St Louis and at Radiological Society of North America, 1990, in Chicago.

Computer Communication Networks↗
PubMed1987

Computer technology: state of the art and future trends.

Computer technology and, more broadly, information technology, are bringing about a fundamental transformation in our society from an industrial economy to an information economy. A review of the short history and present state of information technology identifies two major undercurrents: the miniaturization of computer components, which has produced a millionfold increase in the complexity possible in a single chip of silicon, and the integration of four previously separate areas of information technology: computation, communication, databases and the user interface. Microelectronics, computer networks, data storage and user amenities are the basic technologies that support these four areas and stimulate their progress. Future trends in speech recognition, voice synthesis, artificial intelligence, expert systems, computational imaging and scientific workstations are also examined.

Artificial Intelligence↗
PubMed1984

Potassium supplements and total body potassium in elderly patients.

Total body potassium (TBK) and serum potassium measurements have been obtained in nine elderly patients in controlled heart failure on differing diuretic regimens. The patients were randomly maintained on a potassium-sparing diuretic, on frusemide, and on frusemide with potassium supplements (48 mmol/day) for a minimum of one month. TBK levels increased by a mean of 128 mmol on frusemide with potassium supplements compared with no supplements (P less than 0.001), a 7% increase in TBK. Serum potassium levels increased, similarly, from 4.1 mmol/l to 4.8 mmol/l (P less than 0.01). The potassium-sparing diuretic had the same effect as frusemide with supplements in increasing TBK in six patients. However, in three cases there was no increase in TBK compared with frusemide alone. The results demonstrate that potassium supplements are effective in raising TBK levels and serum potassium levels in elderly patients with heart failure.

Aged↗
PubMed1982

Osteogenesis imperfecta and associated hearing loss in five kindreds.

We examined audiometric data of 30 medically confirmed cases of osteogenesis imperfecta, evaluating pure tone threshold and impedance data to determine the prevalence, type, and degree of hearing loss in five kindreds. Nineteen of the 30 individuals evaluated had normal hearing bilaterally, while 11 had hearing losses of various types and degrees. The results of pure tone testing, tympanometry, and acoustic reflex measurements suggest no clearly established pattern of hearing loss in this population. However, the presence of air-bone gaps and absent acoustic reflexes during the first and second decades support the findings of others, indicating that conductive hearing loss is most prevalent in younger individuals with osteogenesis imperfecta.

Acoustic Impedance Tests↗
PubMed1981

Differences between scorers on selected language measures.

Differences in scores assigned by five speech-language pathologists were determined for 96 language samples utilizing assessments of total words, total sentences, words per sentence, syntax quotient (usage and endings), syntax quotient (structures), and an abstract-concrete scale. Results of the study showed statistically significant interscorer differences for words per sentence, syntax quotient (usage and endings), and the abstract-concrete scale. Although the mean differences between scorers for total words, total sentences, and syntax quotient (structures) were not statistically significant, substantial absolute differences between scorers were found on all six measurement procedures.

Child↗
PubMed1981

Immunoglobulin concentrations in children receiving treatment for acute lymphoblastic leukaemia.

As part of a wider survey of infections and defence mechanisms, concentrations of serum immunoglobulins IgG, IgA, and IgM were measured regularly by single radial immunodiffusion in a group of children receiving treatment for acute lymphoblastic leukaemia while in their first remission. IgM concentrations were often markedly raised at diagnosis, and IgG and IgA concentrations both began falling within one month of diagnosis. Four months after diagnosis all three had fallen significantly, but this tendency stopped after six months. Only IgG partially recovered, and non returned to pretreatment concentrations even in children followed for two years. The results suggest that vincristine and prednisone are the major factors that initiated the fall in IgG and IgA. Lowered IgM concentrations may have been due to cranial irradiation or continuous maintenance treatment, or both.

Child↗
PubMed1977

Lithium in depression: a biochemical study.

Two groups of depressed subjects, one with a history of recurrent depression, the other with a history of persistent apathy, were given lithium carbonate 1,200 mg q.i.d. and supplementart potassium 1,200 mg t.d.s. for 1 week. Measurements were made before and after the lithium treatment of total body water (tritium space), extracellular fluid (sulphate space), total exchangeable sodium (Nae) and total exchangeable potassium (Ke) using sodium-24 and potassium-42 multiple isotope dilution techniques. Prior to treatment when compared with a group of normal subjects, both depressed groups showed changes in body fluid volumes and electrolyte levels. Total body water, intracellular fluid and intracellular potassium were lowered, while electrolyte levels. Total body water, intracellular fluid and intracellular potassium were lowered, while intracellular sodium was raised. After treatment with lithium the values in the apathetic group showed little change but the group with recurrent depression showed a significant increase in intracellular fluid (p less than 0.025), Ke (p less than 0.001), intracellular potassium (p less than 0.025) and a significant decrease in Nae (p less than 0.05). There was a marked increase in mood in the group with recurrent depression but not in the apathetic group following lithium treatment. These findings suggest that recurrent depression, both in clinical improvement, mood and also correction of water and also correction of water and electrolyte disturbances arise, but not in patients with long-standing apathy.

Aged↗
PubMed1976

Anisocytosis and the C-1000 Channelyzer in macrocytic anaemia.

Red cell anisocytosis as assessed using the Coulter Channelyzer C-1000 showed an increase with progressive anaemia in 25 patients with macrocytosis due to B12 and/or folate deficiency. In deficiency of a single factor, the degree of anisocytosis increased with progressive anaemia. In five cases with B12 and folate deficiency combined, anisocytosis was markedly increased out of proportion to the degree of anaemia present. Iron stores were also reduced in four of these cases. It is suggested that objective measurement of anisocytosis is of early diagnostic value in the assessment of multiple haematinic factor deficiency, for example, in macrocytic anaemia associated with malabsorption states and unexpected multiple deficiency states.

Anemia, Macrocytic↗
PubMed1976

Relations between enzymatically estimated myocardial infarct size and early ventricular dysrhythmia.

The relation between ventricular dysrhythmia during the first 20 hours after hospitalization for acute myocardial infarction and enzymatically estimated infarct size was studied prospectively. The duration of dyshythmia was measured by the total time during which the average premature ventricular depolarization (PVC) rate was above 25 PVCs/hr. This index was significantly correlated with infarct size index (ISI) and the strength and significance of the correlation increased when patients with previous, remote myocardial infarction were excluded. An initially expected correlation between PVC frequency and average heart rate was not observed. In a subset of patients selected to include the entire range of ISI, median PVC coupling interval did not correlate with ISI or heart rate. Our results confirm the general reduction of PVC frequency with time after hospital admission. An analysis of total lidocaine administered for therapeutc purposes and dysrhythmia evaluated by retrospective computer analysis disclosed a moderately strong and significant correlation. These findings indicate that persistence and severity of ventricular dysrhythmia in the first 20 hours after hospitalization for myocardial infarction are related to enzymatically estimated infarct size.

Adult↗
PubMed1975

Body weight and body water in chronic cor pulmonale.

1. Body weight was measured through forty consecutive illnesses in seventeen patients with oedema in association with chronic bronchitis and hypoxia. All patients were taking diuretic drugs at the time. 2. Body weight increased little as peripheral oedema and a raised jugular venous pressure appeared. The subsequent weight-loss during treatment was usually greater than the pre-treatment weight-gain. Body weight increased slowly in convalescence to equal or exceed hospital admission weight without a deterioration of general health or reappearance of oedema. 3. Total body water, exchangeable sodium and exchangeable potassium were measured in patients after treatment of the acute illness and clearance of oedema and again in six patients of the group 2-3 months later in convalescence. Total exchangeable sodium was normal or slightly reduced after treatment of oedema and in convalescence between recurrent acute illnesses. Even when gross oedema was present exchangeable sodium was substantially increased in only one of three patients studied at this stage. Total exchangeable potassium was invariably severely depressed. 4. Large changes of body tissue weight without comparable change in exchangeable sodium support previous evidence that oedema in hypoxic bronchitis is not simply a further form of congestive cardiac failure. 5. It is suggested that at least some of the tissue loss in acute exacerbations is a direct result of hypoxaemia and similar to that observed at high altitude. Part of the oedema fluid is thought to be derived from intracellular water released during dissolution of tissue matrix.

Aged↗