Search PubMed⌕ Search

Biomedical subjects

M Lamy

Publications and source records attributed to M Lamy.

At least 199 records · Page 11Linked to original sources
PubMed1986

Laser Doppler flowmetry: muscular microcirculation in anaesthetized horses.

Muscular microcirculation was studied in seven halothane anaesthetised horses in lateral recumbency using a laser Doppler flowmeter. A significant difference between the dependent and the uppermost triceps brachii was recorded. In the dependent muscles, microflow at first decreased and then increased up to the starting value. In the uppermost muscles, a significant rise of the microflow was measured.

Anesthesia, General↗
PubMed1986

The value of serum CK-MB and myoglobin measurements for assessing perioperative myocardial infarction after cardiac surgery.

In 41 patients who underwent coronary bypass surgery, creatine kinase (CK)-MB mass concentration was repeatedly measured in serum during and after the intervention using a new two-site immunoenzymetric assay (IEMA). Serum CK-MB activity was determined with the use of four different techniques: immunoinhibition, immunoinhibition-immunoprecipitation, column chromatography and electrophoresis. Myoglobin (Mb) was also measured in each specimen by radioimmunoassay. In the 33 patients who followed a completely uneventful postoperative course, the cumulated CK-MB release was, on the average, 12.2-fold less than after acute myocardial infarction. The CK-MB peak concentrations using the IEMA were 33 +/- 3 micrograms/l (X +/- SEM) and occurred 6.4 +/- 0.5 h after the intervention was started; CK-MB levels had decreased to 2.9 +/- 0.4 micrograms/l at the end of the first postoperative day. The evolution of the CK-MB concentration was parallel to that of the enzyme activity. The serum Mb maximum concentrations (518 +/- 39 micrograms/l) were reached after 3.3 +/- 0.1 h. The other eight patients developed perioperative myocardial infarction (PMI); in this group, the cumulated CK-MB release was higher, and the serum CK-MB postoperative curves were of three different types. The patients with delayed CK-MB peaks (type I pattern) or sustained elevations (type III) of this isoenzyme also showed increased serum Mb levels at the end of the first postoperative day. The PMI patients with early (10 h) CK-MB elevations (type II) did not demonstrate abnormal serum Mb levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Consumption of pentane by hepatic microsomes and consequences on pentane measurement in exhaled gases.

Pentane measurement in exhaled gases was proposed as a safe method to evaluate the importance of lipoperoxidation in vivo, in man and in animals. However we have observed that pentane, which arises from lipoperoxide decomposition, is significantly consumed by cytochrome P-450-rich liver microsomes. This pentane consumption is completely inhibited after heating the microsomes at 100 degrees C, and is considerably reduced by metyrapone, a cytochrome P-450 inhibitor. Hepatic metabolism of pentane, particularly after cytochrome P-450 induction, constitutes a risk of error, when pentane exhalation is taken as an index of lipoperoxidation in vivo.

Animals↗
PubMed1986

Prostaglandin E2, prostacyclin, and thromboxane changes during nonpulsatile cardiopulmonary bypass in humans.

To study the effect of lung bypass on the production of prostaglandin E2, prostacyclin, and thromboxane A2, we measured simultaneously arterial and venous plasma concentrations of prostaglandin E2, 6-keto-prostaglandin F1 alpha (stable metabolite of prostacyclin), and thromboxane B2 (stable metabolite of thromboxane A2) before, during, and after cardiopulmonary bypass. Seventeen patients (age range 46 to 69 years) undergoing aorta-coronary bypass grafts were investigated. The prostaglandin E2 production rose sharply immediately after the onset of bypass (baseline: 9.7 +/- 2.9 pg/ml to 85 +/- 16.6 pg/ml in venous and 87 +/- 12 pg/ml in arterial plasma, p less than 0.03) and rapidly decreased after pulmonary reperfusion (53 +/- 6.4 and 57 +/- 20 pg/ml, respectively, in venous and arterial plasma at the end of bypass). The increase in prostaglandin E2 was influenced by the heart-lung machine itself (as demonstrated by a closed "bypass" circuit) and by lung bypass. Pulmonary metabolism of prostaglandin E2 was maintained after bypass. The prostacyclin production rose significantly at the beginning of bypass (154 +/- 26 pg/ml venous prebypass level to 361 +/- 94 pg/ml after aortic clamping, p less than 0.03). Prostacyclin decreased progressively during rewarming of the patient, pulmonary reperfusion, and discontinuation of bypass. When prostacyclin decreased, thromboxane B2 production rose significantly and reached peak arterial levels when the lungs were reperfused (112 +/- 33 pg/ml prebypass levels to 402 +/- 101 pg/ml, p less than 0.01). Except for prostaglandin E2, there were no significant differences between arterial and venous plasma levels of these substances. The same prostanoids were also measured in five patients undergoing major orthopedic operations, and no significant changes in prostanoids were observed. Our data demonstrate significant production of prostaglandin E2 in the systemic circulation during cardiopulmonary bypass in humans. They further indicate that lung bypass disturbs the plasma prostaglandin/thromboxane balance.

6-Ketoprostaglandin F1 alpha↗
PubMed1985

[Thaumetopoein, an urticating protein of the processionary hairs of the caterpillar (Thaumetopoea pityocampa Schiff) (Lepidoptera, Thaumetopoeidae)].

The irritating fraction extracted from processionary caterpillar hairs contains soluble proteins which were separated by various electrophoretic and immuno-electrophoretic techniques. Some of these proteins are present also in cuticle and haemolymph. One protein of 28,000 daltons, formed of two subunits (13,000 and 15,000 daltons) is hair specific and causes a reaction in pig skin identical to that produced by hair extract. It is therefore an urticating protein and which we have named "Thaumetopoein".

Animals↗
PubMed1984

Acquired immunodeficiency syndrome in African patients.

Between May 1979 and April 1983, 18 previously healthy African patients were hospitalized in Belgium with opportunistic infections (cryptococcosis, Pneumocystis carinii pneumonia, central-nervous-system toxoplasmosis, progressive cutaneous herpes simplex virus infection, disseminated cytomegalovirus infection, candidiasis, or cryptosporidiosis) or Kaposi's sarcoma, or with both. Ten of them died. During the same period five other patients were hospitalized with an illness consistent with a prodrome of the acquired immunodeficiency syndrome (chronic lymphadenopathy, fever, weight loss, and diarrhea). All patients tested had a marked decrease in helper T cells; an inversion of the normal ratio of helper to suppressor T cells, and a decreased or absent blastogenic response of lymphocytes to mitogens. Twenty patients had anergy. There was no evidence of an underlying immunosuppressive disease and no history of blood-product transfusion, homosexuality, or intravenous-drug abuse. This syndrome in patients originating in Central Africa is similar to the acquired immunodeficiency syndrome reported in American patients.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Immunoreactive trypsin in the adult respiratory distress syndrome.

With the purpose of studying the role of proteinases in the development of ARDS, plasma levels of immunoreactive trypsin (IRT) and amylase were measured in 43 intensive care patients at risk of developing ARDS (22 polytrauma, seven abdominal surgery, four burns, two DIC and eight pancreatitis). Twenty four of these 43 patients developed ARDS and 31 presented abnormal IRT values (above 70 micrograms/L). Twenty-one of these 31 patients had ARDS; a significant correlation thus appeared between ARDS and abnormal IRT values. In nine patients, IRT values were higher than 800 micrograms/L and remained high for 3 to 4 days. A statistically significant correlation also appeared between abnormal IRT and septic phenomena: 20 patients with high IRT values presented septic problems. When IRT values were high, amylase values were often also abnormal: 12 of 23 patients with high IRT had abnormal amylase levels (the eight patients with documented pancreatitis were excluded); no other clinical signs or symptoms of pancreatitis were present in these patients. IRT could be one of the mediators of ARDS in septic patients. It is not clear that the pancreas is the origin of IRT in all cases.

Abdomen↗
PubMed1984

Complement activation in patients at risk of developing the adult respiratory distress syndrome.

In this prospective study of 50 patients, 36 of whom developed the adult respiratory distress syndrome (ARDS), early and intense complement activation was demonstrated. These patients were at risk of the ARDS because of multiple injuries, major abdominal surgery, acute pancreatitis, severe burns, or disseminated intravascular coagulation. Abnormal C3 consumption (as measured by the C3d/C3 ratio) and elevated plasma C5a-like activity (as measured by a leukocyte aggregation assay) were associated with, respectively, 84 and 86% of cases of ARDS. Both tests were more sensitive indicators of complement consumption than were assays of total hemolytic complement activity (CH50) or total C3. The C3d/C3 ratio showed a close, inverse correlation with CH50 in 47 healthy subjects, and was increased in 12 control patients after minor surgery. The C5a-like activity was found only in patients at risk of ARDS; it was highly associated with clinical conditions that predispose to the ARDS, but it cannot be considered as a real predictor of ARDS occurrence in these patients. Sequential samples from both sides of the pulmonary circulation showed initial pulmonary clearance followed by the release of C5a-like activity. No simultaneous changes in C3 levels were found, suggesting the possible presence of modulating factors. These observations suggest that other factors (e.g., hypoxia and metabolic cascades) may influence the development of ARDS.

Complement Activation↗
PubMed1983

Irritating substance extracted from the Thaumetopoea pityocampa caterpillar; mechanism of action.

Hairs of the Thaumetopoea pityocampa caterpillar (Lepidoptera) cause cutaneous reactions in men and animals. A soluble substance extracted from the hairs has been shown to cause a reaction in guinea-pig skin, probably caused by mediators released by mast cells. A direct effect of this substance on mast cells has been shown. Degranulation of mast cells was found to be dose-dependent. Heating of this substance greatly reduced its effects. Proteins fractions are currently being extracted and will be submitted to the same tests.

Animals↗
PubMed1983

[Serum activity of angiotensin converting enzyme during extracorporeal circulation in man].

Serum activity of angiotensin converting enzyme (ACE) were measured during extra-corporeal circulation in five patients undergoing aorto-coronary bypass surgery. We observed a significant decrease of serum ACE levels in the absence of pulmonary circulation, suggesting that in man the lungs were the major source of circulating ACE. An effective extra-pulmonary liberation of ACE could take place during cardiopulmonary bypass. The levels of serum ACE increased with pulmonary recirculation, but preoperative levels were not reached 24 h later.

Aged↗
PubMed1983

Continuous intravenous administration of drugs.

Continuous intravenous administration of drugs may be a problem in clinical practice; for several reasons patients do not always receive the dose of drug intended for them. Problems of parenteral fluid composition are related to the solvent, dilution and drug interactions. Physical factors influencing drug stability are light and adsorption onto perfusion sets. Examples are reported for each problem. A practical solution, based on personal experimentation, is proposed for diazepam and nitroglycerin administration.

Adsorption↗
PubMed1983

[French Guiana "papillonite" (lepidopterism). Clinical and epidemiological study].

Clinical studies by Dr R. Pradinaud (Cayenne) has given prominence to the symptoms of "papillonite": its primary and secondary cutaneous lesions, their localisation and evolution as well as its accompanying symptoms such as respiratory pathology. Epidemiologic survey shows a parallelism between the occurrence of papillonite and the presence of the moth Hylesia urticans. The urticant apparatus of this moth was studied with the scanning electron microscope. "Arrow" (fléchettes) were found and they more or less resemble the urticant apparatus of Thaumetopoea pityocampa Schiff caterpillar. The mechanism of action has been studied in the animal and in humans. Extracts prepared from the "arrows" have been rested in vivo guinea-pigs (bleu Evans, Liacopoulos et al.). The findings seem to incriminate an histamino-liberation.

Animals↗
PubMed1982

[Quantified EEG and CNV changes during inhalation of nitrous oxide].

The present study constitutes an approach to the action mechanisms of nitrous oxide (N2O) by assessing both the subjective effects induced by the inhalation of this anaesthetic gas, and their electrophysiological correlates, i.e., spontaneous EEG, analyzed by a Fourier algorithm, AEP and CNV. The experiment was conducted single blind in 9 volunteers under 3 recording conditions: inhalation of air, of a mixture of 25% N2O--75% O2, and of a mixture of 50% N2O--50% O2. A latin-square design was used. Polymorphic effects of N2O were evidenced on behaviour and on CNS: some of the behavioural manifestations could evoke a depression of SNC: muscle relaxation with difficulty of motor initiation, psychomotor slowing, slower EEG with diminution of the percent alpha component and increase in the percent theta and delta, loss of amplitude of both exogenous (N1) and endogenous (P300) components of the AEP. Conversely, other manifestations were observed that are compatible with an activation of the CNS: increase of sensory perceptions, appearance of perceptual illusions, maintenance of a high CNV amplitude and lengthening of its duration. This dual effect of N2O suggests a dissociative action at the different levels of the CNS.

Adult↗
PubMed1982

Techniques of ventilatory therapy in the adult respiratory distress syndrome (ARDS).

Techniques of respiratory support in ARDS are becoming more and more complex. New modes of ventilatory therapy like continuous positive airway pressure (CPAP), appeared during the last years and became popular; other ones are now under investigation, high frequency ventilation and extracorporeal CO2 removal, for instance. A lot of abbreviations are actually commonly used by physicians involved in intensive care as well as by ventilator industries. The purpose of this article is to review these different modes of respiratory assistance in ARDS, as well as their indications. They are grouped into four categories: mechanical ventilation, spontaneous breathing with positive pressure, a "mature" of both, also called intermittent mandatory ventilation (IMV) and finally extracorporeal support. The respective use of these different modes in our Center of Intensive Care at the University of Liège during recent years is analysed. It appears that mechanical ventilation, especially with positive end expiratory pressure (PEEP) keeps a place of choice and that spontaneous breathing with positive pressure (CPAP) represents one of the best improvements of the late years in respiratory intensive care. Last but not least is the absolute necessity to start respiratory assistance with positive pressure as soon as possible, once the diagnosis of ARDS is suspected.

Adult↗