Showing papers by "St Thomas' Hospital published in 1968"

Prednisolone‐Induced Granulocytosis

Abstract: A neutrophil granulocytosis with peak response at 5 hours develops after the administration of 40 mg. prednisolone tablets. In normal people the increment is greater than 2000 granulocytes per cu.mm. The response declines with advancing age, but is unrelated to sex, height, weight, surface area and initial neutrophil count. The largest responses are seen in young splenectomized people. Of 21 subjects with abnormal marrows only two gave normal responses. The results of this preliminary study suggest that the granulocyte increment following a single oral dose of prednisolone may prove to be a useful index of marrow function. Further studies, particularly serial observations in selected patients, are necessary to establish its validity and to define the role of age and the spleen.

The pattern of glycogen distribution in the liver.

Abstract: The behaviour of glycogen in the rat liver under conditions of fasting, refeeding, and cortisone administration has been investigated in a combined chemical and histochemical study. In contrast to the observations of others the distribution of glycogen in the liver was found to be reasonably uniform. Histochemically, the periodic acid-Schiff reaction was considered to be the method of choice for the assessment of glycogen, particularly at low levels. In sections from frozen dried liver, however, reasonably good results could also be obtained with Best's carmine stain, although this stain was not very sensitive at the lower, and was thought to be too dense for accurate visual assessment at the higher levels of glycogen. As far as the intralobular distribution of glycogen was concerned, no fixed zones of “glycogen deposition” and “glycogen withdrawal” were found, since the intralobular gradient could be altered by varying the experimental conditions. This observation led to the postulate of a “glycogenic wave,” which not only helps to explain some of the contradictory findings in the literature on the localization of glycogen in the liver, but which can also be reconciled with the traditional concept of the liver lobule. The “heterogeneity of the cell population” in the liver lobule was considered to be a function of time rather than of fixed anatomical features.

The structure of a feline picornavirus and its relevance to cubic viruses in general.

Abstract: Using the negative staining technique the pattern of subunits (capsomeres) on the surface of cubic viruses can be revealed as either white projections against a dark background (“posimeres”),e.g. adenoviruses, or as dark hollows surrounded by a lighter rim (“negameres”),e.g. reoviruses. A symmetrical pattern of 32 “negameres” has been demonstrated for some recently isolated feline picornaviruses and from an extension of these studies, based on radiographs of foam-rubber models, it is postulated that “posimere” or “negamere” formation may be obtained by relatively minor variation of a basic structure unit.

Deoxyrtbonucleic acid (dna) loss, cell loss and cell turnover in exfoltative psoriasis

Abstract: SUMMARY. DNA was measured in the naturally exfoliated skin scales from 2 patients with generalized exfoliative psoriasis. The mean DNA values indicated that the rate of loss of cells from the skin in these 2 patients was approximately 4 million/min. No DNA was found in skin scales from 3 patients with ichthyosis vulgaris. The difference in DNA content of scales in these disorders appeared to reflect the fact that psoriatic scales were nucleated, whereas the ichthyotic ones were not. It is suggested that the DNA content of psoriatic scales is a reflection of the high turnover of epithelial cells in this condition.

The effect of respiratory manoeuvres upon skin oxygen tension and blood flow.

Abstract: SUMMARY.— Oxygen tension at the surface of inflamed skin and alveolar oxygen tension were measured polarographically. Changes in blood flow were indicated by a water perfused thermocouple disc resting on the skin. Breath holding, voluntary hyperventilation, Valsalva's manoeuvre, coughing, Muller's manoeuvre and arterial occlusion all produced transient changes in skin oxygen tension. These could largely be explained in terms of the observed changes in alveolar oxygen tension and skin blood flow.

Mechanism of Excretion of Iron by the Small Intestine: an Experimental Study in Rats with Normal and Abnormal Mucosae

Abstract: The findings in the present study have demonstrated the presence of two distinct mechanisms of iron excretion by the small intestine in rats. Loss of cell bound iron is the principal pathway of excretion and takes place as epithelial cells are shed off from the tips of villi. The available evidence suggests that the epithelial cells of the mucosa sequestrate iron from a storage pool which might be identical to the labile iron store in man. Transferrin bound iron makes a small contribution to the total loss. An abnormally large amount of iron was excreted in the small intestine of rats infested with Nippostrongylus brasiliensis. At the same time an unduly large amount was also sequestrated by the intestines of these rats. These facts were attributed to increased population of maturing cells in the crypts and the rapid rate of renewal of the villous epithelium. The morphological appearances of the intestinal villi of the infested rats have a resemblance to those in human subjects with coeliac disease. It is, therefore, suggested that these observations may have some bearing on the status of iron balance in patients suffering from coeliac disease.

Use of a Local Indicator Dilution Technique for the Measurement of Oscillatory Flow

Abstract: An indicator dilution method for measuring oscillatory flow in a vessel is analyzed in terms of a mixing chamber with a constant volume For the correct measurement of mean flow, the time constant of detection of the indicator should be very much shorter than the shortest time constant of the mixing volume The performance of such a system was examined with a thermal indicator Although the apparent mixing volume was found not to be constant but to vary with flow, the method showed no significant error in the measurement of mean flow There was no significant "distance distortion error" when the indicator was detected at two different points downstream from the site of infusion; this was attributed to the pattern of mixing, with detection within or close to the limits of the mixing volume It is concluded that a properly designed indicator dilution system can measure mean blood flow without significant error, even when there is an socillatory component

Measurement of a Labile Iron Store

Abstract: Summary. A method for the quantitative measurement of a labile iron store has been described. The validity of the method was established by demonstrating quantitative differences between normal individuals, patients with iron deficiency and patients with iron overload. The method does not measure total body iron, but appears to give reproducible estimates of a labile fraction. Evidence has also been presented to show that the iron present in this labile store is immediately available for haemoglobin synthesis and that iron derived from immediate haemoglobin breakdown enters this labile iron store.

Copper-tellurite-copper thermocouples for measuring acute changes in skin blood flow.

Abstract: SUMMARY. Heat flux across the surface of human skin may be measured with copper-tellurite-copper thermocouple discs perfused on one side by water at a constant temperature. If the water is at about 45° C., inflammation develops in the skin under the disc within 15 min., and the changes in e.m.f. corresponding to acute changes in skin blood flow can be recorded. With a water temperature of 33° C., these blood flow changes are not easily followed.