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Biomedical subjects

M Raymond

Publications and source records attributed to M Raymond.

At least 109 records · Page 6Linked to original sources
PubMed1986

cDNA clones for liver cytochrome P-450s from individual aroclor-treated rats: constitutive expression of a new P-450 gene related to phenobarbital-inducible forms.

Differential hybridization and screening with cloned inserts was used to identify two families of cytochrome P-450 cDNA clones in libraries prepared from total liver poly(A)+RNA of individual Aroclor-treated rats. One family has cDNA inserts for the major phenobarbital-inducible P-450s, P-450b and P-450e. Two types of P-450e inserts were identified. In addition, irregular inserts were characterized from two clones (PB23 and PB24) of this group. The other family has cDNA inserts for the major 3-methylcholanthrene-inducible species, P-450c and P-450d. No coding sequence restriction site variants were detected among 26 P-450d and P-450c inserts analyzed. The restriction map of the irregular 2.2-kb PB23 insert has a P-450b-like portion, followed by a 3' extension that hybridizes to RNAs of 2.7 and 4.8 kb, which are also detectable with a classical P-450b probe. The PB23 insert and the 2.7- and 4.8-kb RNAs presumably represent 3' extensions of P-450b/P-450e mRNAs, polyadenylated at downstream sites. The 858-bp sequence of the PB24 insert encodes the carboxy-terminal portion of a P-450b/P-450e-like protein. There is approximately 20% divergence at the polypeptide level between the PB24 and P-450b/P-450e sequences; nevertheless, they share many essential features. A PB24-specific probe hybridizes to a 1.9-kb RNA species which is present in the liver of untreated rats and which is not appreciably induced by phenobarbital or Aroclor. The PB24 cDNA most likely represents a constitutive cytochrome P-450, related to phenobarbital-inducible forms.

Amino Acid Sequence↗
PubMed1985

Single-mosquito test to determine genotypes with an acetylcholinesterase insensitive to inhibition to propoxur insecticide.

A sensitive technique allowing to identify the three genotypes (AceSS, AceRR and AceRS) of the Ace gene existing in natural populations of Culex pipiens in southern France is described. The technique is based on the comparison of AChE (acetylcholinesterase) activity in 3 equal aliquots taken from the homogenate of a single mosquito (a) in absence of inhibitor (RA), (b) in presence of eserine that inhibits the AChE encoded by AceS and AceR alleles (RI) and (c) in presence of a concentration of propoxur inhibiting the AChE coded by the AceS allele but not by the AceR allele (RG). The mosquito tested is AceSS when RG = RI, AceRR when RG = RA and AceRS when RI less than RG less than RA.

Acetylcholinesterase↗
PubMed1985

Pharmacokinetics of insulin infused intra-peritoneally via portable pumps.

Plasma free insulin was measured repeatedly for 4 hours following a standardized breakfast in 20 C-peptide negative chronically pumped type I diabetic patients and 5 normal subjects. In the former group, insulin was given as a 1 u/h basal infusion and a 1h superimposed meal-dose of 6 u via a peritoneal (IP) catheter lying in the low (n = 10), or in the mid-abdomen (n = 10). The results of the IP patients were correlated with glycosylated haemoglobin and home capillary blood glucose. Fasting free insulin of IP patients was lower than those of normals (14.7 +/- 0.5 vs 21.0 +/- 1.3 mU/l, p less than 0.01). Dose-induced peak occurred similarly in IP patients and normals (70 +/- 6 vs 70 +/- 12 min.). Values tended to baseline after 165 +/- 15 and 185 +/- 22 min. in IP patients and normals (NS). Results of the mid--and low peritoneum subgroups differed only for peak values (31.5 +/- 2.9 vs 25.0 +/- 1.6 mU/l respectively) and did not correlate with diabetic control.

Adult↗
PubMed1984

Bileaflet, tilting disc and porcine aortic valve substitutes: in vivo hydrodynamic characteristics.

The St. Jude valve is a new bileaflet disc cardiac valve prosthesis designed to avoid some of the hemodynamic drawbacks of other prostheses. The in vivo flow characteristics of the St. Jude aortic valve (42 patients) were studied and compared with those of three other commonly used aortic prostheses. Björk-Shiley (12 patients), Hancock (27 patients) and Carpentier-Edwards (15 patients). The studies, performed 24 to 48 hours after surgery, included measurements at rest and during augmentation of valve flow by infusion of isoproterenol. The mean performance index for valves of all sizes is higher for the St. Jude than for either porcine valve, both at rest and during isoproterenol infusion (p less than 0.05). Utilizing data both at rest and with isoproterenol, the relation of valve flow and mean systolic gradient for each size of St. Jude valve (19 to 25 mm) indicates the occurrence of small increases in gradient (5.3 to 8.2 mm Hg) as valve flow increases, ranging from 161 to 436 ml/systolic X min. A direct comparison of valve flow and gradient data for all size 25 and 23 mm prostheses at rest indicates a tendency for a lower mean systolic gradient in both mechanical valves than in either porcine valve (p = 0.07). With isoproterenol augmentation of valve flow in 25 mm valves, the gradient is less (p less than 0.05), and the effective orifice area and performance index are larger (p less than 0.05) for the St. Jude than for either porcine valve.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Coping with transient intellectual dysfunction after coronary bypass surgery.

In summary, we believe that the impact of our findings on the patient and clinician includes recognition and acknowledgment that transient cognitive dysfunction frequently follows coronary bypass surgery. With this recognition comes the reassurance to the patient and his family that it is a temporary phenomenon that should resolve in time. To help the patient comply with his postoperative instructions during this difficult time period, there should be individual, slow-paced presentation of material with intentional repetition of information to help him remember the specific details of his postoperative instruction; the individual most involved with assisting in the patient's postoperative recovery should be included in all teaching sessions; and instructive audiovisual material should be used in postoperative home care.

Adaptation, Psychological↗
PubMed1982

Preoperative prediction of reversible myocardial asynergy by postexercise radionuclide ventriculography.

Myocardial asynergy is sometimes reversed by coronary bypass, and a noninvasive method of predicting which assess are reversible would be desirable. To assess whether changes in myocardial wall motion observed immediately after exercise can differentiate reversible from nonreversible myocardial asynergy, we evaluated 53 patients by radionuclide ventriculography before and after exercise and again at rest after coronary bypass surgery. Preoperative improvement in wall motion immediately after exercise was highly predictive of the surgical outcome (average chance-corrected agreement, 91 per cent). At surgery the asynergic segments that had improved after exercise were free of grossly apparent epicardial scarring. The accuracy of these predictions for postoperative improvement was significantly greater (P less than 0.01) than that of analysis of Q waves on resting electrocardiography (average chance-corrected agreement, 40 per cent). In contrast, preoperative changes in left ventricular ejection fraction after exercise were not predictive of postoperative resting ejection fraction. We conclude that postexercise radionuclide ventriculography can be used to identify reversible resting myocardial asynergy. This test should prove effective in predicting which patients with myocardial asynergy are most likely to benefit from aortocoronary revascularization.

Adult↗
PubMed1982

Effects of digoxin on myocardial oxygen supply and demand in patients following coronary artery bypass surgery.

Although digoxin is used frequently in patients in the prophylaxis of postoperative supraventricular tachyarrhythmias, the effects of the drug on myocardial oxygen supply and demand after coronary bypass have not been described. Seven adult patients with good ventricular function who underwent myocardial revascularization were studied before and three hours after digoxin (0.5 mg, iv). There were no significant changes observed in any measured systemic hemodynamic variable. Evaluation of global myocardial metabolism showed an increase in myocardial oxygen consumption (P less than 0.05) which was compensated satisfactorily, as no significant alteration was noted in the coronary sinus oxygen content, or in the lactate gradient across the myocardium. Since the authors studied the effects of only one dose of digoxin, the effects of full digitalization in these patients remains to be defined.

Aged↗
PubMed1982

Myocardial metabolism and hemodynamic responses to halothane or morphine anesthesia for coronary artery surgery.

Eighteen patients having coronary artery bypass grafts were randomly anesthetized with morphine (1 mg/kg) or halothane and oxygen. Central and peripheral pressures were measured serially, plus cardiac output and total coronary sinus blood flow, both by thermodilution catheters, starting before induction of anesthesia and continuing until completion of sternotomy. No significant differences in hemodynamic responses were seen between the two anesthetic techniques during induction: blood pressure and peripheral vascular resistance decreased significantly, but not cardiac output or coronary flow. Myocardial oxygen consumption decreased significantly with induction as oxygen content of coronary sinus blood increased, indicating preservation of oxygen balance. Heart rate and blood pressure increased after sternotomy in the patients given morphine, with the myocardium producing lactate in two of six patients and with nitroprusside being required in four patients to decrease arterial pressure. Halothane-oxygen anesthesia effectively controlled autonomic responses to sternotomy, although one of 12 patients had myocardial lactate production at that time. Neither rate-pressure product or ST segment changes were useful predictors of the ratio between myocardial oxygen consumption and supply. Myocardial oxygen balance can be maintained in coronary patients before cardiopulmonary bypass if pulse rate and blood pressure are kept at less than awake levels.

Adult↗
PubMed1982

Cardiovascular effects of morphine in patients with coronary arterial disease.

Large doses of morphine sulfate have been reported to cause myocardial lactate production and reduction in coronary blood flow in animals. Similar effects with clinical doses in man would significantly alter the management of cardiac patients. Eleven adult patients with significant coronary arterial disease and normal left ventricular ejection fraction were studied before and 30 minutes after infusion of morphine (0.25 mg/kg IV). Evaluation of myocardial metabolism showed an increase in coronary sinus oxygen content (p less than 0.001) and a reduction in myocardial oxygen consumption. Myocardial lactate extraction was not altered. No change in coronary sinus blood flow was seen. It is concluded that infusion of morphine sulfate, 0.25 mg/kg IV, does not produce global myocardial ischemia in patients with coronary artery disease and normal ventricular function.

Aged↗
PubMed1982

Effects of protamine sulfate on myocardial oxygen supply and demand in patients following cardiopulmonary bypass.

The effect of protamine sulfate on myocardial oxygen supply and demand was studied under clinical conditions in nine patients following cardiopulmonary bypass. Before surgery, the patients had severe coronary artery disease with good ventricular function. The patients required no vasoactive drugs, but only blood volume adjustments when weaned off bypass, and were hemodynamically stable at the time of study. The protamine dose of 196 mg (2.5 mg/kg) was infused over 4 +/- 1 minutes. Although modest variation in hemodynamic function occurred in individual patients after administration of protamine, there were no significant hemodynamic alterations for the group. No significant alteration in global myocardial metabolism was observed. Protamine caused a small decrease in measured coronary blood flow, resulting in a corresponding reduction in calculated myocardial oxygen consumption as coronary sinus oxygen content remained unaltered. Myocardial lactate extraction showed no significant alteration. It is concluded that protamine sulfate, given at rapid infusion rates in hemodynamically stable patients, is not associated with an adverse alteration in hemodynamics or global myocardial metabolism.

Aged↗
PubMed1981

Use of thallium-201 redistribution scintigraphy in the preoperative differentiation of reversible and nonreversible myocardial asynergy.

Thallium-201 (201Tl) redistribution scintigraphy might differentiate reversibly from nonreversibly asynergic myocardial segments and thus predict the response of these segments to coronary artery bypass grafting (CABG). To test this hypothesis, 25 consecutive patients undergoing CABG, preoperative stress-redistribution 201Tl scintigraphy, and both pre- and postoperative resting equilibrium radionuclide ventriculography were evaluated. For both types of scintigraphic study, each patient was imaged in the same three views. Because of the effects of CABG on septal motion, this region was considered separately. Postoperative improvement was noted in 54% of 72 preoperative asynergic segments. Improvement was common not only in hypokinetic but also in akinetic and dyskinetic segments, and occurred in a similar proportion of studies performed early (less than 2 weeks) or late (3-6 months) after CABG. Thallium-201 redistribution scintigraphy was highly predictive of the pattern of postoperative asynergy: The redistribution pattern was normal in 90% of segments with reversible asynergy and abnormal in 76% of segments with nonreversible asynergy. The presence or absence of pathologic Q waves was less sensitive in this differentiation. Septal segments, however, frequently demonstrated abnormal wall motion postoperatively, despite normal 201Tl redistribution scintigraphy. Resting left ventricular ejection fraction (LVEF) was generally unchanged postoperatively, but in some patients with multiple areas of reversible asynergy it did improve. Thus, 201Tl redistribution scintigraphy appears to reliably distinguish viable from nonviable asynergic myocardial zones, and predicts the response of these segments to CABG.

Coronary Artery Bypass↗
PubMed1976

The lipid composition of sebaceous glands as a reflection of gland size.

Following 4 h incubation in vitro, the patterns of incorporation of [I-14C] acetate into the lipid classes of human sebaceous glands which were dissected from small skin biopsies have been established for glands of different size. It has been shown that in the larger sebaceous glands proportionately more of the labelled acetate is incorporated into squalene at the expense of triglycerides. Experiments are presented as a result of which we conclude that this in vitro phenomenon, observed with [I-14C] acetate incorporation, does reflect parallel changes in the proportions of these lipids actually present in glands of different size. It is suggested that the larger sebaceous glands of the acne patient elaborate sebum which has an enhanced potential for inducing comedo formation by virtue of an increased concentration of squalene. This work also demonstrates that, in the interpretation of in vitro studies of sebaceous gland lipogenesis utilizing labelled precursors, the size of the sebaceous glands must be carefully considered whenever patterns of incorporation are being compared.

Acne Vulgaris↗