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Biomedical subjects

S Laurent

Publications and source records attributed to S Laurent.

At least 253 records · Page 14Linked to original sources
PubMed1983

[Hemodynamic and coronary effects of molsidomine in patients with stable coronary insufficiency in the basal state, during an atrial stimulation test and a cold test].

The heart rate (HR), the cardiac output (Qc) and the coronary sinus flow rate (Qcs), the left ventricular systolic and end-diastolic pressures (LVSP, LVEDP), the femoral artery pressure (FAP) and the difference between the coronary arterial and coronary venous oxygen tension (DAVcO2) were measured in patients with stable coronary insufficiency without cardiac failure, before and 40 to 60 minutes after 2 or 3 mg of molsidomine (M). In 20 patients, these measurements were made in the basal state, in spontaneous rhythm (SP). In 8 of these patient, (including 3 receiving beta-blockers) the measurements were made during an atrial stimulation test (ST) and in 8 other patients, all receiving long-term beta-blocker therapy, the measurements were made during a cold test (CT). At the basal state in SR, a gradual reduction in the LVSP to 70% or less of its initial value was observed in the patients receiving 3 mg of M (2 of whom received beta-blocker treatment). The LVSP was immediately restored by vascular filling. In 16 patients, M decreased the LVSP, the LVEDP, the FAP, the Qc and the double product (DP = LVSP X HR). The DAVcO2 was unchanged. Qcs and MVO2 (MVO2 = Qcs X DAVcO2) were decreased. In the course of ST, the haemodynamic and coronary changes are similar to those seen in the basal state. During the Ct, the increase in the LVSP, FAP and DP was significantly reduced by M. The variations in Qcs and coronary resistance (FAP/Qcs) were also significantly different after M., with better metabolic regulation of the coronary circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1980

[Influence of hydrothermic and enzymatic treatments on the nutritive value of Faba beans: in vitro study].

In order to improve the digestibility of the Faba bean flour an hydrothermic enzymic and fermentation treatment has been thought out (US patent 395 8015, Ets Ury, M. Gay). This study aims at stemming out the nutritionnal and structural repercusions of this treatment on the Faba proteins. The nitrogen distribution is deeply changed : total nitrogen increase (47%), water soluble nitrogen decrease (41%), water soluble non-protein nitrogen increase. The treatment can enrich the flour in nitrogen but the proteins supplement is insoluble in water. The treatment changed the electrophoretic behaviour of flour proteins letting disappear precipitable pH 4,5 proteins. Amino acid composition is slightly changed, however there is an increase of lysine and methionine (15 et 25%) and a decrease of cysteine (28%). The chemical score shows sulfur amino acids and tryptophan deficiency. Enzymatic (pepsine and pancreatine mixture) liberation of all amino acids is low and is not improved by the treatment but for the lysine. Cell proteins supplement, which appeared during the treatment (61%), water insoluble, could improve nutritive value of the flour if a more complete destruction of the cell walls permitted their liberation and their solubilization.

Amino Acids↗
PubMed1977

[Anesthesia with continuous infusion of alfatesine and phenoperidine. Uses in anesthesia of aged subjects in visceral surgery].

Anaesthesia was administered to one hundred and fifty eight patients by continuous infusion of a mixture of Alfatesine and phenoperidine. The patients were divided on two groups: group A consisted in 96 patients undergoing abdominal surgery and group B of 62 cases of various types of surgery, mainly orthopedics. The average age was 63 years (range 16-96). The operative risk scored 6 or more in 71 cases. The length of operation averaged 151 minutes (S.D. +/- 15). The mixture made of alfadione 25 ml and phenoperidine 5 mg in a glucose 5 per cent 250 ml solution was administered by mechanical pump. The induction dose was 50 ml of the mixture for patients under 50 years (rate 10 ml per minute), 40 ml per patients from 50 to 70 years (5 ml per minute), and 30 ml for patients over 70 years (5 ml per minute). The maintenance dose was adjusted to weight and age and ranged from 0,11 to 0,15 ml/kg/h for alfadione and from 0,022 to 0,030 mg/kg/h for phenoperidine. Routine tracheal intubation and artificial ventilation were performed in group A. The results are studied in relation to the effectiveness of the anaesthesia mixture, its side effects and influence on recovery. Generally, the results are good and emphasize the value of the technic in abdominal surgery for elderly patients. The methods of application are discussed in terms of medical background.

Adult↗
PubMed1976

[Effect of prolonged glucidic starvation on the contents of starch and tannins of Blechnum brasiliense L. gametophytes].

Some Blechnum brasiliense gametophytes have been maintained in darkness, in a purely mineral medium, for the purpose of investigating the effect of prolonged glucidic starving on the amount of tannins and starch that they contain. During the first two months the tannin contents undergoes a fast decrease. The starch variations are different : a transitory increase simultaneous with the fall in tannin; a decrease after the disappearance of 3/4 of the tannin contents; and lastly, a new amylogenese which precedes the prothallus necrosis. It seems that the gametophytes, in order to survive, degrade first their tannoidic reserves, and they utilize the starch that they contain only with difficulty. This behaviour can be explained by the distribution of the two metabolites; by the acid pH of the medium, which is not very propitious to the phosphorylases activity and lastly by the presence of chlorogenic acids, which are inhibitors of those enzymes.

Cells, Cultured↗
PubMed1975

[Comparative study of different extraction methods and assays of tannins in some pteridophytes].

Various processes of extraction and quantitative analysis of a condensed tannin in a plant extract, which also includes some chlorogenic acids, have been examined. 60% methanol, at 50 degrees C, proved the most efficient extraction solvent. Several methods of analysis have been tried. The measure of the colour intensity obtained by the action of sulphuric vanilline on flavanols cannot be used because it depends on the tannin condensation stage. It is impossible to separate tannin from chlorogenic acids using the methods of adsorption by skin or nylon powders, or precipitation by polyvinylpyrrolidone. Only paper chromatography, followed by the distinct elution of the various phenolic compounds, allows the tannin evaluation by subtraction; but owing to the variability of the results, many more experiments are necessary. Some other processes are being studied.

Chlorogenic Acid↗
PubMed1975

[Anesthesia in reoperations in abdominal surgery].

Fifty one patients from different surgical units, hence anesthetized by different anaesthesists, underwent reinterventions in abdominal surgery. The indications for the first intervention essentially involved the supra-mesocolic region of the abdomen (62 out of 100 cases). The operative risk during the first intervention was on the average 18 pour cent. The protocol of the first anaesthesia which was known in 42 cases, was of the narco-ataralgestic type. The date of the return to the operation table varied from 1 to 60 days. The state of the patients was in general catastrophic (organic renal failure, acute respiratory failure). Here again the anaesthesia was of the narco-ataralgesic type but the choice of drugs varied depending on the patients' state. However non significant difference was noted in the average hourly drug consumption between the two interventions. Apart from one circulatory arrest during induction, in one patient with hemorrhagic shock, no death was attributable to the anesthetic technique. The authors, using these findings, attempt to pick out a practical line of behaviour.

Abdomen↗
PubMedDate not supplied

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for colorectal peritoneal carcinomatosis: higher complication rate for oxaliplatin compared to Mitomycin C.

BACKGROUND: Peritoneal carcinomatosis (PC) from colo-rectal cancer carries a very poor prognosis with a mean and median overall survival times of 6.9 and 5.2 months. It has been proved that a locoregional therapeutic approach of this disease with cytoreduction followed by hyperthermic intraperitoneal chemotherapy (HIPEC) improved survival of these patients. However, this combined treatment presents a high complication rate. METHODS: 21 patients with PC of colorectal origin underwent complete cytoreduction followed by HIPEC using Mitomycin-C (13 patients) or oxaliplatin (8 patients) and the open coliseum technique. For each case the medical datas were retrospectively analysed to determine feasibility, morbidity, mortality, survival time and prognostic factors. RESULTS: All patients presented a Sugarbaker's Peritoneal Cancer index inferior to 15. The mean operating time was 453 minutes. After a median follow-up of 24.9 months, actuarial disease-free survival was 36.6% at 5 years. The median survival time was 34 months. The morbidity rate was 33.3% with a significant higher complication rate in the oxaliplatin group (5/8) than in the Mytomycin-C (MMC) group (2/13). One patient (4.7%) died two months after treatment with MMC (endocarditis). CONCLUSIONS: This series confirm positive impact of cytoreduction and HIPEC on PC. We obtained a moderated complications rate thanks to a high degree of selection of the patient. Oxaliplatin scheme is responsible of a higher morbidity than in MMC group. Phase III trial comparing these two drugs is needed.

Adult↗
PubMedDate not supplied

Comparative effects of captopril and isosorbide dinitrate on the arterial wall of hypertensive human brachial arteries.

Blood pressure, diameter, volume distensibility, and compliance of brachial artery were measured noninvasively in patients with sustained essential hypertension before and after Captopril in 11 patients and before and after isosorbide dinitrate (ISDN) in 11 other patients. Both drugs caused a similar significant decrease in mean arterial pressure (MAP) (p less than 0.001) and increase in arterial compliance (p less than 0.001), defined as the product of arterial volume by distensibility. ISDN increased arterial compliance through a dominant increase in arterial diameter (0.524 +/- 0.029 vs. 0.455 +/- 0.022 cm; p less than 0.001) and hence volume, whereas Captopril increased compliance through an increase in volume distensibility (0.20 +/- 0.02 vs. 0.12 +/- 0.02% change volume/mm Hg; p less than 0.001) with minimal changes in arterial diameter. The study provided evidence that of the two vasodilating drugs, ISDN and Captopril, only Captopril caused a predominant pharmacological relaxing effect on the wall of hypertensive human brachial arteries studied in situ.

Adult↗
PubMedDate not supplied

Growth and growth hormone therapy in hypochondroplasia.

The growth of 84 patients with hypochondroplasia (56 male, 28 female) was studied. A wide spectrum of severity was found from quite severe short limbed dwarfism to short apparently normal prepubertal children who manifested disproportion only at puberty when growth failed. The onset of puberty was at the normal time but the pubertal growth spurt appeared not to materialize and it is this lack which resulted in severely compromised adult heights of 145-165 cm in boys and 133-151 cm in girls. Twenty (12 M, 8 F) hypochondroplastic children aged between 4.3 and 12.8 years were recruited to a study of the effects of biosynthetic growth hormone. All had normal growth hormone responses (greater than 15 mU/l) to a pharmacological test of growth hormone secretion. Biosynthetic growth hormone in doses between 12-32 mu/m2/week produced a significant acceleration in height velocity standard deviation score (SDS) for chronological age (CA) from a pretreatment mean of -1.66 (SD 1.36) to +1.62 (SD 1.52) (p less than 0.001). Significant increases were also observed in the height SDS for bone age (BA), sitting height (SH) SDS and subischial leg length (SILL) SDS. A longer period will be required to assess the effect of treatment on adult height prognosis.

Adolescent↗
PubMedDate not supplied

Noninvasive measurement of medium-sized artery intima-media thickness in humans: in vitro validation.

Recent research in ultrasound technology has led to the development of a high-resolution echo-tracking device. The present study was performed to evaluate the accuracy in the measurement of human radial artery intima-media thickness with this new device. We determined the correlation between histological and ultrasonic measurements of intima-media thickness in 15 radial artery segments obtained from the distal end of the wrist-elbow harvest for coronary bypass grafting in patients with coronary heart disease. For arterial intima-media thickness, a positive correlation was observed between ultrasonic and histological measurements (r = 0.618; p < 0.014), and the difference between ultrasound and histology measurements was 41 +/- 66 microns, with the higher measurements found by the ultrasonic device. In a subgroup of 11 patients, we determined the correlation between in vivo ultrasonic measurements of radial artery intima-media thickness at the preoperative stage and in vitro ultrasonic measurements of intima-media thickness obtained postoperatively in the same arterial segments. Internal diameter was larger in vivo than in vitro, and intima-media thickness was smaller in vivo than in vitro. The cross-sectional area of the arterial wall was calculated from internal diameter and intima-media thickness. In vitro wall cross-sectional area was correlated with in vivo wall cross-sectional area (r = 0.929; p < 0.0001). Repeatability of in vivo intima-media thickness measurements was investigated in 10 subjects through the calculation of the repeatability coefficient as defined by the British Standards Institution.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation Studies as Topic↗