Biomedical subjects
M Critchley
Publications and source records attributed to M Critchley.
Liver volume and uptake assessment using 123I-BSP tomography.
Liver volume and parenchymal cell uptake of 123I-bromosulphthalein (BSP) has been assessed using the technique of single photon emission tomography (SPET). These results have been compared with a clinical scoring of disease severity and also with results for liver volume and tomographically assessed uptake of 99Tcm-sulphur colloid (SC). Comparisons of volume estimation, geometric mean (GM) uptake curves and a distribution index derived by a mapping technique with both radiopharmaceuticals, show that 123I-BSP tomography is feasible. A short acquisition time is required in order to obtain tomographic information before there is significant biliary excretion. There was a significant difference between the mean percentage uptake of 123I-BSP in the three groups of liver disease severity (P less than 0.002). This technique merits further evaluation in the study of the assessment of functional liver impairment.
Relationship between gastric emptying of solids and gall bladder emptying in normal subjects.
Very little is known about the normal temporal and quantitative relationships between gastric emptying and gall bladder emptying. Using a non-invasive double isotope technique these relationships were investigated in 22 normal healthy adults. 99Tcm EHIDA was used as the biliary tracer and 113Inm labelled bran as the gastric content tracer. Gastric emptying was monoexponential with a t1/2 of 45 +/- 3 minutes (mean +/- SEM). In 15 subjects the gall bladder emptied in relation to eating according to a double exponential function. In these subjects 15.0 +/- 1.6% of gall bladder contents emptied before gastric emptying began. They could be further divided into two clear cut types (p less than 0.001), according to the ejection fraction at 10 minutes and the t1/2 of the first exponential. Emptying of the gall bladder was faster and more of its contents were ejected in subjects with a type I response (n = 9) than in subjects with a type II response (n = 6). In the remaining seven subjects the gall bladder began to empty spontaneously, unrelated to eating. These observations suggest that gall bladder emptying: (a) may have a cephalic phase, (b) can be expressed as a double exponential function, (c) may occur unrelated to eating, (d) which occurs only in relation to eating would appear to be either fast (type I) or slow (type II).
And all the daughters of musick shall be brought low. Language function in the elderly.
Language, including articulated speech and also, communication of ideas in writing, is liable to progressive alteration with advancing years. This process may appear early or late and may advance throughout the presenescent-senescent-senility continuum. An attempt is made to discuss these changes objectively, and from the standpoint of linguistics, their possible bearing upon the more fundamental problem as to the nature of the aging process is mentioned.
Histological evaluation of quantitative scintigraphy of the salivary glands in a primate model.
To assess the accuracy with which quantitative scintigraphy reflects the true extent of parenchymal losses in diseased salivary glands, the parotid glands of vervet monkeys were unilaterally subjected to experimental injury and studied by scintigraphy and histomorphometry. The glandular 99Tcm pertechnetate uptake, relative to a standard dose, was expressed as the ratio of operated to unoperated sides. This was compared with the equivalent ratios of the weights of various salivary component tissues, morphometrically determined at necropsy. Our results suggest that uptake levels of 99Tcm pertechnetate are influenced predominantly by the mass of acinar rather than ductal tissue present. Furthermore, in comparisons between scans, because of the inherent variability in the results, quantitative scintigraphy is sensitive only to differences exceeding 25% of the gland mass.
The history of Huntington's chorea.
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Aphasiology: present status and trends.
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Technetium-99m labelled bran: a new agent for measuring gastric emptying.
Bran was labelled with 99mTc-pertechnetate, ingested as part of a normal meal and used to measure gastric emptying in 15 normal subjects and in 15 patients with ulcerative colitis. There was no significant difference between the gastric emptying curves of the normal subjects and the patients, suggesting that rapid gastric emptying does not contribute to diarrhoea in ulcerative colitis.
Portal scanning for liver metastases in colorectal carcinoma.
In a prospective study over 2 years, 14 patients suffering from colorectal cancer had radionuclide liver scans performed via the portal route. Technetium-99m-labelled macro-aggregates of human serum albumen were injected via the cannulated umbilical vein, distributed through the portal system of the liver and their presence recorded by a gamma camera. Of 11 patients with clinically normal livers and no metastases found at laparotomy, five had abnormal portal scans, two of these dying from multiple liver metastases during follow-up. None of the patients with normal portal scans died with liver metastases within the 2-year study period.
How much does aphasia contribute to the localization of language?
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Defective pictorial interpretation: a pervading deficit in patients with higher nervous dysfunction.
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Radionuclide assessment of extravascular lung water in minimal pulmonary oedema.
Extravascular lung water (EVLW) has been measured by a non-invasive technique using 123I-antipyrine and 113Indiumm-transferrin, as diffusible and non-diffusible indicators, and a gamma-camera computer system. Group A patients were normal radiologically and clinically. Group B patients were radiologically normal, clinically normal but were previously in heart failure and are currently on diuretics. Group C patients were radiologically normal, currently on diuretics with signs of pulmonary oedema. EVLW per unit blood flow and per unit blood volume were normal in groups A and B but raised in Group C patients. The peak height to equilibrium ratio of the 123I-antipyrine first pass curve was itself a useful discriminator in minimal pulmonary oedema.
The clinical significance of dysprosody.
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Assessment of renal transplantation using a gamma camera computer system.
Five hundred eleven isotope studies were performed following renal transplantation in 130 patients, using a standard technique and a gamma camera computer system in a nuclear medicine department situated half a mile away from the renal transplant unit. A comprehensive picture of renal function is obtained from perfusion studies, renography, effective renal plasma flow, I-131-Hippuran uptake, and excretion measurements.
An equilibrium radionuclide technique to assess the effect of propranolol on left ventricular function in thyrotoxicosis.
Radionuclide imaging of the left ventricular blood pool provides a convenient non-invasive method of monitoring left ventricular function. Left ventricular function is characterised by the left ventricular curve which represents all phases of the cardiac cycle and is obtained by a multiple gated equilibrium method (MUGA). Volume curves were obtained over a minimum 1 1/2 h period in 15 normal subjects and in 20 thyrotoxic patients. Changes in left ventricular ejection fraction (LVEF), maximum ejection fraction rate and total electromechanical time interval were recorded from volume curve data. To assess the effect of pharmacological intervention, serial measurements of LVEF were made before and after 40 mg oral propranolol. In thyrotoxic patients, LVEF decreased by 17% of the initial value and in normal subjects by less than 10% following propranolol. This method can be extended to assess the effects of physiological or pharmacological intervention on left ventricular function in other disease states.
Ergotamine tartrate overdosage.
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In memoriam. A. R. Luria.
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