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Biomedical subjects

M Casey

Publications and source records attributed to M Casey.

At least 37 records · Page 2Linked to original sources

GFR measurement by simulating constant infusion with data acquired using a CdTe detector. A feasibility study.

Conventional nuclear medicine methods for measuring glomerular filtration rate, GFR, are invalidated if the initial injection of radiopharmaceutical is tissued. An analytical method proposed by Veall and Gibbs in 1982 overcomes this difficulty but does require multiple blood samples. This paper investigates whether it is feasible to use the analytical method on data acquired with a CdTe detector system and thereby reducing to one the number of blood samples required. Synthetic data were used to investigate the effect of (a) duration of sampling (b) statistical noise and (c) non-stationarity on the GFR values derived by the Veall and Gibbs method. A sampling duration of 100 min is shown to be adequate and statistical noise is not a limiting factor. However, data fluctuations, mainly due to detector motion, do reduce the accuracy of the method. When the analytical technique is applied to data obtained using a CdTe detector on 40 patients the GFR values are similar to those derived by the conventional method (r = 0.957, Syx = 9.1 ml min-1). The technique is sufficiently attractive to warrant further studies to establish its absolute accuracy.

Computer Simulation

Effects of an inverted position on blood pressure, pulse rate, and deep tendon reflexes of healthy young adults.

This study reports the effects of an inverted position on pulse rate, blood pressure, and deep tendon reflexes of the biceps muscle, triceps muscle, and Achilles tendon. Twenty healthy adults were used as subjects. We collected data both before and after the subjects were in the inverted position for eight minutes on a specially designed tonic labyrinthine inverted table. A significant decrease in systolic blood pressure and all tendon reflexes was observed along with a significant increase in diastolic blood pressure (p less than .05). Pulse rate showed no change. The findings indicate that the inverted position is likely to be effective for decreasing muscle tone and systolic blood pressure. Although this study used healthy subjects, the inverted position may be used as a therapeutic technique, provided the clinician monitors closely the physiological effects on patients.

Achilles Tendon

Measurement of secretory IgA in serum by radioimmunoassay in patients with chronic nonalcoholic liver disease or carcinoma.

The authors describe the development of a double antibody radioimmunoassay specific for human secretory IgA (sIgA), and they report the results of measurements of serum sIgA concentrations in patients with chronic, nonalcoholic liver disease or carcinoma. Above-normal sIgA concentrations (greater than 25 micrograms/mL) were found in 22 of 38 sera from patients with chronic active liver disease and in 37 of 40 sera from patients with primary biliary cirrhosis. Markedly increased concentrations (greater than 118 micrograms/mL) were specific for primary biliary cirrhosis. Above-normal sIgA concentrations were found frequently in patients with colorectal (29/86, 34%), pancreatic (38/70, 54%), gastric (11/30, 37%), or mammary (6/46, 13%) carcinoma. An above-normal concentration of sIgA was more specific for hepatic metastases than an above-normal alkaline phosphatase activity in each type of carcinoma. The authors conclude that measurement of sIgA in serum is a useful diagnostic test in patients with chronic liver disease suspected of having primary biliary cirrhosis or in patients with carcinoma suspected of having hepatic metastases.

Adult

Alcohol consumption and cognitive functioning in college students.

Decreased cognitive performance was significantly correlated with increased quantity of alcohol per occasion and with total lifetime consumption in both women and men college students tested while sober. In men, however, increased performance on some tasks was also significantly correlated with increased frequency of drinking.

Adult

Quantitative measurement of activity in small sources containing medium energy radionuclide: comparison of the gamma camera and the rectilinear scanner.

The response of a gamma camera and a rectilinear scanner to small sources containing 131I was assessed from the point of view of thier suitability for measuring the activity of a source, as opposed to their capacity to produce well-resolved images. The influence of the size of the area over which counts were integrated, and of the size and depth of hte source, were investigated for both instruments. The results indicate that both instruments are dependent on these variables, though with the particular instruments investigated the dependence of the gamma camera is much more complex and difficult to define. The conclusions indicate that with these systems quantitative activity measurements are more readily achievable with the scanner than with the camera.

Iodine Radioisotopes

Serum acid phosphatase activities in patients with lung cancer: a biochemical and immunohistochemical analysis of 25 cases.

A series of 25 cases of lung cancer are presented in which total (TAcP) and nonprostatic serum acid phosphatase (NPAcP) activities were measured. Of these cases, 36% had raised TAcP and NPAcP activities in their serum. However, the serum activities of TAcP and NPAcP did not correlate with either the presence of lung cancer nor with the morphological tumour type. This fact indicates that, despite isolated reports of raised serum acid phosphatase activities in cases of lung cancer, acid phosphatase is of no value as a marker for lung cancer. We sought alternative explanations for the raised TAcP and NPAcP activities observed in our series in the hope that this enzyme might prove useful as a marker for early metastatic disease in lung cancer patients. This possibility is not substantiated, and the findings are analyzed and discussed. It is tentatively suggested that raised NPAcP activities in patients with lung cancer may relate to haemostasis.

Acid Phosphatase

An infertility data registry.

A computerized infertility data registry form has been developed in order to facilitate the storage of a large amount of reproductive data to allow subsequent analyses pertinent to the managment of the infertile couple. This abstract form of the patients' medical records had been readily applied to computer analysis using the SPSS reporting system. The abstract can be utilized both for the facilitation of patient management and as a means for obtaining a standardized, objective, retrospective review of clinical data. Through the evaluation and standardization of the therapeutic techniques frequently utilized by physicians, the treatment of infertile couples should be improved. Such an approach is essential for anyone involved in today's health care system.

Female

The root canal game.

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Evaluation Studies as Topic

Iron-dependent binding of 8-anilinonaphthalene-1-sulphonate by both lactoferrin and transferrin.

Fluorescence of 8-anilinonaphthalene-1-sulphonate is enhanced by both lactoferrin and transferrin. The enhancement is relatively low between pH 4 and 8, and high at below pH 4. At physiological pH the fluorescence enhancement is higher with the iron-deprived than with the iron-saturated proteins. Binding of iron by lactoferrin is associated with lowering affinity for the dye.

Anilino Naphthalenesulfonates

Performance evaluation of the positron scanner ECAT EXACT.

The Cologne Special is a prototype of the ECAT EXACT (model 921), a new generation of Siemens-CTI PET scanners. It consists of three rings of 48 BGO block detectors each, covering an axial field of view of 16.2 cm with a patient port of 56.2 cm diameter. This results in a total of 24 rings with 384 crystals each, giving 47 contiguous image planes in two-dimensional (2D) mode. Total system sensitivity is 216 kcps/microCi/ml for a 20 cm cylinder phantom in 2D. This increases to 1.5 Mcps/microCi/ml in 3D. Data are acquired in the stationary mode only (no wobble motion), resulting in a transaxial spatial resolution of better than 6 mm full width at half-maximum (FWHM) at the center, which degrades to 7.5 mm tangentially and 9.6 mm radially at a radius of 20 cm. Average axial resolution changes from 5.0 mm FWHM at the center to 8.1 mm at R = 20 cm. Count rate performance was investigated at different low energy discriminator settings and found to be linear up to 2.5 microCi/ml with a 20 cm phantom. The magnitude and distribution of scatter were evaluated for both septa-extended and septa-retracted conditions for a range of energy thresholds. Brain, heart, and whole-body studies with the new tomograph demonstrate the versatility of its applications without compromising on physical performance.

Equipment Design