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Biomedical subjects

G Nicolas

Publications and source records attributed to G Nicolas.

At least 73 records · Page 4Linked to original sources
PubMed1986

[Myocardial contusions. Contribution of scintigraphy using thallium-201. A prospective series].

Traumatic myocardial contusion is observed in 15% of autopsy studies; however, it is much more difficult to detect in survivors. Thirty-two consecutive, unselected patients admitted to the intensive care unit for serious thoracic injuries, underwent Th 201 myocardial scintigraphy in 2 to 4 different projections, 2 to 13 days after admission. The results were interpreted double blind and considered positive when a zone of hypofixation creating a defect greater than 25% was observed. The results were correlated with daily ECG recordings, serum CPK MB levels and echocardiography. Thirteen patients (41%) had abnormal scintigraphy. Border line appearances in 1 case excluded any severe myocardial lesions. The other investigations (56%) were normal. These results did not correlate with the ECG or echocardiographic appearances but a significant relationship was found with serum CPK MB levels (p less than 0.05). Therefore, the first investigations did detect cardiac damage but were not specific for myocardial lesions. Thallium 201 myocardial scintigraphy is superior to other non-invasive investigations. It provides information as to the size of the lesion and, by repeated studies, can differentiate simple myocardial contusion from a true traumatic myocardial infarction.

Adolescent↗
PubMed1986

[Anti-aggregating agents: for which patients?].

Platelets are at the center of the phenomenon leading to thrombus formation; they also occupy an important place in the process leading to the development of the atheromatous plaque: these two actions justify the interest taken in anti-platelets medications in cardiac pathology. In spite of the uncertainties remaining about this very controverted subject, it seems that the prescription of an anti-platelets medication is legitimate in all situations where there is a danger of formation or extension of a thrombus. Within the scope of coronary pathology, the most recent trials show a favorable action of anti-platelets medications in unstable angina, aorto-coronary by-pass or the secondary prevention of myocardial infarction. In addition, it is recommended to start the treatment as quickly as possible before surgery, as far as cardiac surgery is concerned. Finally, concerning the dispute about the optimal dose of aspirin, the current tendency is to advocate a moderate dosage.

Angina, Unstable↗
PubMed1985

Severe protein C deficiency in congenital thrombotic disease--description of an immunoenzymological assay for protein C determination.

An immunoenzymatic assay (ELISA) is described for the quantitative assay of protein C in plasma. This technique allows a safe, reliable, and sensitive assay of protein C, and is easily used for routine investigation. Using this technique, a protein C deficiency (0.16 U/ml) was discovered in a 16 year old patient with a history of very severe thrombotic disease. Protein C deficiency was also discovered in his mother (0.62 U/ml) and father (0.50 U/ml). We therefore suggest that this case could represent a homozygous deficiency of protein C.

Adolescent↗
PubMed1985

Two mucous cell types revisited after quick-freezing and cryosubstitution.

The ultrastructures of mucous cell from mouse colon and quail oviduct were revisited after quick-freezing followed by cryosubstitution and compared with results from standard fixation. After quick-freezing, the mucous cells of both models do not show the classical aspect of the goblet cell. The secretory granules which contain a dense product do not swell and coalesce as observed after standard fixation. The large condensing vacuoles which are formed in the Golgi region can be discriminated from mature granules only after quick-freezing. Cytoplasmic organelles and cytoskeletal elements are observed between the secretory granules. The nucleus is ovoid and contains dispersed chromatin, whereas it has a reduced volume and contains condensed chromatin after standard fixation. It is assumed that during standard fixation, the membrane of mucous granules becomes permeable to water inducing hydration of mucous and swelling of granules. The term "goblet cell" could be descriptive of a fixation artefact.

Animals↗
PubMed1985

[Magnesium, calcium, zinc, potassium, total and HDL cholesterol and total creatine kinase in 37 cases of instable angina: a correlation study].

Plasma and erythrocyte magnesium (P-Mg, E-Mg), zinc (P-Zn, E-Zn) and potassium (P-K, E-K), plasma calcium (P-Ca), HDL-cholesterol and total cholesterol and total creatine kinase (TCK) were determined in 37 cases (26 men, 11 women) of unstable angina pectoris (UAP) on the first day of hospitalization. The same variables, except P-K and TCK, were measured in 58 male and 53 female reference subjects. The methods of measurement were emission spectrometry for K, atomic absorption spectrometry for Mg, Ca and Zn, and the R CK NAC-activated Merckotest for TCK. According to the normality of distributions, statistical analysis of results was performed either by parametric or nonparametric tests. Multiple (R), simple (r) and Spearman (rs) correlation coefficients were calculated, and only significant correlations (p less than or equal to 0.05) were accepted. There was no significant R for UAP patients. For UAP men, r was negative and significant between P-Mg and E-K, but positive between P-Ca and P-Zn, as for reference subjects; and rs was negative and significant between P-Zn and TCK. For UAP women, only rs was positive and significant, between P-Mg and TCK. In the UAP population, contrary to the reference population, there were no significant differences relative to sex. In comparison with reference men, UAP men presented a significant (p less than 0.005) increase in E-Mg and significant (p less than 0.001) decreases in P-Ca and P-Zn.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

A monitoring study of cardiotonic treatment by immunoenzymologic measurement of digoxinemia (emit).

We performed a study on 96 patients to compare monitoring by immunoenzymologic measurement (EMIT) of digoxinemia. In doing so, we uniquely relied on clinical and electrocardiographic results. Compliance was good because only 9 patients had a digoxinemia equal or below 0.8 ng/ml, but we emphasize that our patients were hospitalized. Correlation between intoxications and plasmatic levels shows that 5 patients presented clinical or electrocardiographic signs indicative of digitalis intoxication with a digoxinemia less than 2.5 ng/ml and 14 patients without intoxication with a digoxinemia higher than 2.5 ng/ml. We point out in this study that for EMIT immunoassay it is better to take 2.5 ng/ml as the concentration limit to be sure to avoid intoxication.

Adult↗
PubMed1984

[Ontogenetic changes of effects of carbon dioxide on the electroretinographic responses of Locusta migratoria cinerascens: influence of the animal breeding conditions].

Short term exposition of locusts to CO2 (1 min) greatly reduces the amplitude of electroretinographic responses induced by a lengthened light stimulation (5 s). The effects are significant immediately at the end of the treatment and may alter the visual responses for a prolonged period (10 min up to 60 min). In the course of ontogenesis, the reactivity of animals to CO2 decreases as shown by the increased delay necessary to obtain the maximum effect and by the reduction of the time-course of the effects. The breeding condition of locusts influences their responsiveness to CO2. Animals bred in grouping are less sensitive to CO2 action than isolated animals or crowded ones submitted to a daily CO2 narcosis. Discussion of the results is developed in relation with the CO2 action mechanisms and the functioning of the compound eye of the insect as well as in relation with the inhibition of the effects of crowding induced by CO2, possibly as a result of the reduction of the "sensorial flux" in high density population.

Aging↗
PubMed1983

[Biological study of a case of analbuminemia].

A new case of analbuminemia in a fifty-four-year-old French woman is described. The patient was admitted to a hospital cardiology department for thoracic pain. Consanguinity between the patient's parents was established. Proteins were studied both during the acute phase and the subsequent remission. Total serum protein concentrations were stable, around 5.3 g. Hypoalbuminemia was compensated initially by alpha-2-globulins and subsequently by beta globulins. Increases in serum cholesterol and serum beta lipoproteins were recorded. Hydroelectrolytic balance was normal. Orthostatic renin and aldosterone release was significantly increased, denoting response to lowered hydrostatic pressure. A minor increase in serum thyroxin was recorded, probably because of the increase in thyroxin binding globulin.

Bilirubin↗
PubMed1983

Are rhoptries of Coccidia really extrusomes?

Some evidence that rhoptries of invasive stages of Coccidia are extrusive organelles has been found in a study of Toxoplasma, after conventional electron microscopy, cryosubstitution preparations, and freeze-fracture. Periodic rows of intramembranous particles were seen in the membrane of the rhoptries. The ducts of the organelles are positioned by two microtubules, and joined to an apical vesicle, through the conoid. Above the vesicle in the plasmalemma, there is sometimes a "rosette" of intramembranous particles. Extrusion of a dense substance was seen at the same time as an anterior vacuole. This represents degenerative "empty" rhoptries. This paper discusses whether rhoptries of Coccidia can be put in the group of extrusomes of protists.

Animals↗
PubMed1983

[Strategy of the medical treatment of angina pectoris].

The first objective is to correct any existing coronary risk factors but this must be achieved with discrimination. Smoking should be strictly forbidden, hypertension reduced and a more active life style encouraged. However, a more nuanced approach should be adopted towards dietetic problems, obesity and disorders of lipid metabolism. It is also very important to teach the patient to use glyceryl trinitrate correctly in the double objective of relieving pain as quickly as possible and of preventing pain by using it in certain critical situations. Clinical practice shows that patients often use glyceryl trinitrate too sparingly. When these general measures have been settled, treatment must be adapted to each particular situation. The patient's age, the frequency of attacks, trigger factors, the repercussions of the disease on the patient's life all have to be considered before deciding on the individual's treatment. In younger patients, a controlled exercise ECG is essential for selecting patients for surgery. The drugs of choice for stable angina are the betablockers which have been shown to be effective and well tolerated. When this group of drugs cannot be used or is ineffective, other major anti-anginal drugs may be chosen according to the individual terrain and their known secondary effects.

Adrenergic beta-Antagonists↗
PubMed1983

[Comparison of the cardiotoxicity of adriamycin and aclacinomycin A in the rat. Optical and electron microscopic study].

Adriamycin (ADM) is a very effective antimitotic agent but its use is limited by its cardiotoxicity. New anthracycline drugs such as aclacinomycin A (ACMA) have been developed and have to be compared with ADM after chronic experimental intoxication. Three groups of randomised rats were compared: the ADM group receiving 2 mg/kg/week X 13 by intraperitoneal injection; the ACMA group receiving 4 mg/kg/week X 13 and a control group: 7 rats. The rats were autopsied at the 20th week. The heart was stopped in diastole and fixed by aortic retroinfusion of glutaraldehide for electronic microscopy (EM). In the ADM group, mean weight fell from the 4th week and mortality was 11/16 at 20 weeks. Voluminous haemorrhagic ascites was associated with peritoneal fibrosis in 12/16. Cardiac failure was observed in 4 cases but on light microscopy (LM) myofibril degeneration was constant and focal without sarcoplasmic reticulum or mitochondrial changes on EM. In the ACMA group the loss of weight occurred at 10 weeks and mortality due to toxicity was nil. There was no cardiac failure; myocytolysis was absent on LM and slight in 4/13 cases on EM with a moderate dilatation of the sarcoplasmic recticulum and presence of numerous residual bodies in the striated skeletal fibres in 5/15 cases. In this study, the ACMA had very little cardio and general toxicity in comparison with ADM. The technique of fixing the heart by retrograde infusion prevents, as far as possible, artefacts on EM affecting mainly the mitochondria.

Aclarubicin↗
PubMed1983

[Endomyocardial biopsy as a method of surveilling adriamycin cardiac toxicity. 28 biopsies in 26 patients].

The aim of this study was to evaluate the role of endomyocardial biopsy in the surveillance of toxic, latent cardiomyopathy secondary to adriamycin (ADM) therapy, and to assess its value by comparison with non-invasive investigations such as echocardiography. Twenty six patients underwent endomyocardial biopsy and echocardiographic measurement of the fractional shortening of the left ventricular internal diameter after a total dose of 150 to 520 mg/m2 of ADM. Interstitial fibrosis was observed in 8 of the 20 interpretable cases on light microscopy (6 moderate, 2 severe). There were no cellular changes. Slight focal myofibril degeneration was observed in 8 cases, and vacuolisation corresponding to mild dilatation of the sarcoplasmic reticulum was observed in 9 cases out of the 22 technically interpretable cases on electron microscopy. In contrast to the findings of interstitial fibrosis, cellular degeneration correlated significantly with the total dose of ADM (p less than 0,01). We conclude that this histological study confirms the fact that myocardial changes are rare and slight with doses of less than 520 mg/m2 of ADM and that non-invasive techniques are adequate for follow-up until this dose is reached.

Adult↗