[Use of structured lights in the evaluation of thoracic deformity bound with cardiac activity. Study of apical impulse using Moiré technics]. / Utilisation des lumières structurées dans l'évaluation de la déformation thoracique liée à l'activité cardiaque. Etude de l'impulsion apicale à l'aide des techniques du Moiré.

Chest deformation due to cardiac activity can be studied with the use of techniques based on Moiré principle. The shadow technique allows to obtain well contrasted fringes, whereas the technique of projected Moiré allows an easier taking of camera pictures. The fringes in this case, although less contrasted, allow to recognize level differences of the order of 0.17 mm with a network of 20 traits/mm in the present configuration of our material. The best criteria of registration have been set up after the study of 10 young subjects. In the presented case topographic measurements allowed a quantitative evaluation of the apical impulse. The telesystolic image after treatment allowed a tridimensional reconstruction of chest deformation.

Evaluation of chest wall distortion related to cardiac activity by structured lights. A study of the apical impulse by the Moiré technique.

The use of structured lights and especially of the Moiré technique to evaluate chest wall distortion in front of the apical impulse allows a topographic study of the precordial movement in relation with cardiac activity. Shade Moiré technology offers the possibility to study a reduced area of the chest with a good enlargement effect and well contrasted fringes. Projected Moiré allows the study of an increased area of the chest (40 cm2) and provides less contrasted pictures with a reduced enlargement effect. Both techniques offer the possibility of automatic imaging. The study of a normal subject is realized with a topographic evaluation of the chest wall distortion on a endsystolic frame. 3D representation of the chest wall deformation is performed after image treatment on a endsystolic print.

Population dynamics of arterial cells. XIV. Evidence for no significant G2 arrest of intimal and medial cells in young nonatherosclerotic swine.

In an earlier study of swine results from analysis of tritiated thymidine data by an "ancestor table" method suggested a substantial arrest of arterial cells in the G2 phase of the cell cycle. A later study with a cytofluorometric method gave contradictory results with no evidence for significant G2 arrest. On reexamination of the earlier data with the ancestor table method in the light of current knowledge, it was found that the fact that nuclei in the S and G2 phases prior to division are larger than those in G1 after division had not been taken into account. The main purpose of the current study was to find out whether the evidence for G2 arrest would entirely disappear if adjustments were made for differences in nuclear sizes before and after division. A baseline group sacrificed 2 hr after tritiated thymidine injection and two experimental groups (one fed hyperlipidemic diet and the other given cholesterol-free mash) sacrificed 47 hr after injection were studied. Using the ancestor table method it was found that virtually all labeled arterial cells divided in both groups; thus there is no evidence for G2 arrest. The data was also analyzed with a form of the "mean grain count halving" method and this also showed all labeled cells dividing.

Population dynamics of arterial cells during atherogenesis. XIII. Mitogenic and cytotoxic effects of a hyperlipidemic (HL) diet on cells in advanced lesions in the abdominal aortas of swine fed an HL diet for 270-345 days.

The abdominal aortas of five groups of young male Yorkshire swine were studied: (1) 0-day baseline group; (2) hyperlipidemic (HL) group with ballooning; (3) mash group with ballooning; (4) mash group without ballooning; and (5) HL group without ballooning. The last four groups were injected with [3H]thymidine at 270 days and sacrificed subsequently in subsets at intervals up to 75 days in order to study births and deaths (or loss by migration) among cells over the period 270-345 days. However, only in the HL-ballooned group were there enough swine for the isotopic data to be useful for most purposes. In the 0-day baseline group there were 6 +/- 2 X 10(6) cells in intimal cell masses (ICM); in the 270- to 345-day mash group without ballooning the number was 10 +/- 2 X 10(6), which is not a statistically significant increase over 0-day. This supports the hypothesis that in the normal state births and deaths (or loss by migration) among cells in ICM are nearly balanced at least up to 1 year of age. In the 270- to 345-day mash group with ballooning there were 61 +/- 12 X 10(6) cells in the ICM. Thus a single episode of deendothelialization results in tremendous hyperplasia of ICM. However, even the largest ICM (atherosclerotic lesion) in this group showed essentially no necrosis. In the 270- to 345-day HL group with ballooning there were 108 +/- 17 X 10(6) cells in the ICM turned atherosclerotic lesions. In addition an average of one-third of the lesion volume was occupied by lipid-rich, calcific necrotic debris. Thus the HL diet appears to have associated with it both mitogenic and cytotoxic influences on ICM cells. In the 270- to 345-day HL group not ballooned there were 130 +/- 30 X 10(6) lesion cells and lesions were somewhat more extensive and necrotic than in the HL-ballooned group, probably because the former group included by chance more hyperresponders (as regards serum cholesterol values) to the HL diet than the latter. Regardless of this, the data suggest that in this particular model of advanced atherosclerosis the balloon-injury stimulus to proliferation and the HL-diet stimulus are neither additive nor synergistic.(ABSTRACT TRUNCATED AT 400 WORDS)

Differentiation, ageing, and terminal differentiation: a semantic analysis.

The largely unsolved problems in the theoretical analysis of differentiation and ageing involve a substantial component of linguistic (semantic) difficulties. Some of these are simple traps of ambiguity, resulting from metaphorical or analogical employment of established terms--for example, "terminal differentiation" (loss of division potential in vitro) as a borrowing from "differentiation" as used by developmental biologists, or "commitment" by analogy with "determination". Some difficulties represent a failure to adopt (at least provisionally) an operational (empirical) view--for example, failure to ask what is the nature of the evidence for the view that a fertilized ovum is totipotential, or to scrutinize the evidence for the view that cells "terminally differentiated" in vitro in a conventional medium are in fact moribund under all conditions, or to examine more closely the view that the differentiated state and the cycling state are mutually exclusive. With respect to the problem of ageing, we review some of the critical experiments on "terminal differentiation" or "clonal senescence". We then proceed to consider some of the models that have been proposed, including a molecular model proposed by the author which appears to overcome some of the objections to other models. Some of the models exemplify the results of what are ultimately semantic vices. The problems with which these remarks began should indeed yield to the immense and novel resources of molecular biology. But the development of complete analyses demands not only good luck and delicate technique but also critical semantic clarity and severity. Given the best tools, we shall solve major theoretical problems only if we understand quite fully what problem it is that we are trying to solve--and the history of science illustrates that this is not as elementary a matter as it sounds.(ABSTRACT TRUNCATED AT 250 WORDS)

Circadian variation of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity in swine liver and ileum.

The temporal variation of HMG-CoA reductase activity in the liver and intestine of swine was investigated. The thin-layer chromatographic method widely used in the assay of the reductase was successfully applied to the porcine enzymes. Parallel circadian rhythms were demonstrated in both hepatic and ileal reductases from mash-fed animals. Peak activity occurred approximately 6 hr after feeding, 2.7-fold over the basal level in the liver, and 1.6-fold in the ileum. A milk-cholesterol diet caused a marked depression of both rhythms (90% in liver, 50% in ileum); however, the hourly variation in activity persisted in both organs. Cholestyramine was found to elevate hepatic activity (2.7-fold throughout the rhythm) without affecting that of the intestine. Clofibrate had no effect on either enzyme at any time during the cycle despite a 34% reduction in serum cholesterol concentrations.

Evans blue dye. Accumulation in swine aortic intimal cell collections and atherosclerotic lesions.

A two-part study concerned the accumulation of intravenously injected Evans blue dye in the abdominal aorta of swine. In normolipidemic swine weighing up to 90 kg each, Evans blue accumulated predominantly in areas of the aorta that were the site of intimal smooth muscle cell collections. The second part of the study dealt with Evans blue accumulation in swine with advanced atherosclerosis. The extent of blue staining in these animals was not significantly different than in normolipidemic, nonatherosclerotic swine of the same size. The dye showed a predilection for raised atherosclerotic lesions, but only one quarter of the surface of these lesions was stained. Histologic studies of the uppermost portion of blue and nonblue lesion areas showed that the dye preferentially accumulated in regions with lower concentrations of foam cells. Injected isotopic cholesterol tended to accumulate in the blue rather than the nonblue areas.