[Vasomotor activity and coronary insufficiency]

Provocative testing has provided a method of evaluating the important role of vasomotor tone in coronary artery disease. The most sensitive test is the ergonovine (Methergin) test. This is a specific and reliable method of defining the clinical situations in which coronary spasm is common: --focal coronary artery spasm is mainly observed in resting angina alone or in association with effort angina. The prognosis of spasm is excellent with calcium antagonist therapy provided there is no other associated pathology such as left ventricular failure or triple vessel disease; --in the six weeks following myocardial infarction, focal coronary artery spasm is a common event: 20% of coronary angiographies. After six weeks, spasm is much less frequent. It does not influence the prognosis. This type of spasm is probably related to the scarring process; --coronary artery spasm is frequently associated with restenosis after coronary angioplasty, a process which is histologically related to proliferation of smooth muscle; --diffuse increase in coronary vasomotor tone is a much rarer pathology, perhaps related to global changes in vascular tone as its association with the Raynaud syndrome and with migraine would suggest. It presents clinically with resting angina and sometimes by typical Prinzmetal angina; --finally, vosomotor tone plays an important role in the daily life of coronary patients. Holter recordings for the detection of silent myocardial ischemia have shown episodes of myocardial ischemia at lower myocardial oxygen consumption levels than those usually recorded during exercise stress testing, which suggests a reduction in oxygen supply, that is to say coronary vasoconstriction. Changes in coronary vasomotor tone can modify the diameter of healthy coronary arteries by 100%.(ABSTRACT TRUNCATED AT 250 WORDS)

A new radioimmunoassay for the determination of the angiotensin-converting enzyme inhibitor perindopril and its active metabolite in plasma and urine: advantages of a lysine derivative as immunogen to improve the assay specificity

A new radioimmunoassay (RIA) was developed for the direct measurement of perindoprilate (PT), the active metabolite (diacid) of Perindopril (P), an angiotensin-converting enzyme (ACE) inhibitor. Antibodies were raised in rabbits against the lysine derivative of PT conjugated to bovine serum albumin. The p-hydroxyphenyl derivative of the lysine analogue was used for preparation of the radioligand by iodination (125I). Cross-reactivities for the glucuronide metabolites of P and PT are low (0.25 and 3.5%, respectively). The theoretical limit of detection is 0.2 nM, the sensitivity attainable with random samples is about 0.5 nM. Within- and between-assay variabilities observed were 4.2-6.7 and 2.8-5.9%, respectively (concentration range 2.1-41.7 nM). Serial dilution of plasma and urine samples showed excellent parallelism (r greater than 0.95; P less than 0.001). Recoveries of PT spiked to urine and plasma samples were 90-120%. The prodrug P can be measured in the same sample (plasma/urine) after chromatographic separation on a Dowex AG 1 x 2 anion-exchange column and quantitative alkaline hydrolysis of the P-containing fraction. It is concluded that the specificity and sensitivity of this assay are amply sufficient for pharmacokinetic studies and in patient monitoring.

The metabolic pathways of tianeptine, a new antidepressant, in healthy volunteers

The metabolism of tianeptine, a novel antidepressant that presents original neurochemical properties, was studied after a single oral administration of radioisotopically (14C) labeled compound to six healthy male volunteers. After 7 days, approximately 66% of the dose was eliminated by renal excretion (55% during the first 24 hr). Tianeptine is extensively metabolized, and 24 hr after the administration, the unchanged molecule contributed in urine for less than 3% of the administered dose. Chromatographic and mass spectral studies showed that beta-oxidation of the amino acid side chain is the major route of biotransformation for tianeptine. Three major metabolites, accounting for 29% of the dose, were products of beta-oxidation. The metabolite profiles of tianeptine in feces and plasma were qualitatively similar to that in urine.

Interspecies comparison of the metabolic pathways of perindopril, a new angiotensin-converting enzyme (ACE) inhibitor

1. The metabolism of perindopril (non-thiol angiotensin-converting enzyme inhibitor) was studied in rat, dog and monkey after single oral and i.v. administration of 14C-perindopril, and in man after a single oral dose. 2. Six biotransformation products of perindopril from urine, faecal and plasma samples (bile only for rats) were identified. 3. The main route of biotransformation in all species is the hydrolysis of the carboxylic ethyl ester side-chain, with the formation of perindoprilate, the active metabolite. 4. A minor route of biotransformation led to the acyl glucuronides of perindopril and perindoprilate. 5. Internal dehydration of perindopril and perindoprilate into cyclic lactam structures occurs. This route of metabolism is of minor importance except in humans.

Comparison of isoflurane with sodium nitroprusside for controlling hypertension during thoracic aortic cross-clamping

The aims of this randomized study were (1) to determine if isoflurane is effective in controlling blood pressure during thoracic aortic cross-clamping, and (2) to compare its effects on hemodynamics and oxygen transport to those of sodium nitroprusside. Sodium nitroprusside (SNP group, n = 10) or isoflurane (ISO group, n = 10) was started 2 minutes before cross-clamping and was adjusted to maintain systolic arterial pressure as near as possible to preinduction values. The duration of thoracic aortic cross-clamping was 26 +/- 4 minutes in the SNP group and 30 +/- 4 minutes in the ISO group. Administration of isoflurance and sodium nitroprusside was stopped 2 minutes before unclamping. The same anesthetic technique using fentanyl, 6 micrograms/kg, flunitrazepam, 0.02 mg/kg, pancuronium, 0.1 mg/kg, and 50% N2O was used for all patients. At the time of clamping, either isoflurance (maximal expired concentration, 2.5% +/- 0.3%) or sodium nitroprusside (cumulative dose, 11.1 +/- 1.0 mg) was effective in maintaining the systolic blood pressure below 160 mm Hg, whereas the pulmonary capillary wedge pressure did not change. However, only SNP was able to bring the arterial pressure above the cross-clamp back to postinduction levels. During clamping, stroke index values were similar in both groups, but cardiac index increased only in patients receiving SNP. In both groups, at clamping and unclamping, PvO2 was higher than postinduction values, indicating that throughout the study the oxygen needs of the perfused area were adequately met. There was no evidence of acute left ventricular decompensation because pulmonary capillary wedge pressures did not abruptly increase, nor did pulmonary edema occur.(ABSTRACT TRUNCATED AT 250 WORDS)

Prospective randomized comparison of fluorouracil versus fluorouracil and high-dose continuous infusion leucovorin calcium for the treatment of advanced measurable colorectal cancer in patients previously unexposed to chemotherapy

Seventy-nine patients with advanced, measurable, metastatic colorectal cancer previously unexposed to chemotherapy were randomly assigned to treatment with either fluorouracil (FUra) administered intravenously at a dose of 370 mg/m2/d for 5 days or the combination of FUra in the same dose and schedule with high-dose continuous infusion leucovorin calcium (500 mg/m2/d) beginning 24 hours before the first dose of FUra and continuing for 12 hours after the completion of FUra therapy. Patients whose disease progressed on treatment with FUra alone were, if eligible, crossed over to receive leucovorin and FUra. Three patients on the FUra plus leucovorin arm of the study were excluded from the analysis because they did not meet eligibility requirements. The treatment arms were well balanced for prognostic criteria including performance status, age, prior radiotherapy, distribution of metastatic sites, and on-study carcinoembryonic antigen (CEA), lactic dehydrogenase, and serum albumin. FUra plus leucovorin was superior to FUra alone for response (P = .0019) and for time to progression or death (log-rank, P = .045). Response rates were 16 of 36 (44%) versus five of 40 (13%), and median time to progression or death was 164 versus 120 days in the two arms of the trial, respectively. Overall survival, however, while longer in the FUra and leucovorin arm was not significantly so. An analysis of the toxicities experienced by the patients in the two treatment groups showed that, except for significantly more stomatitis in the leucovorin arm of the study, the side effects experienced by patients treated with either regimen were comparable. These results suggest that the efficacy of FUra in patients with advanced, measurable, metastatic colorectal cancer can be enhanced significantly by administration of a continuous high-dose infusion of leucovorin calcium.

[Venous catheterization and congenital abnormalities of the superior vena cava]

Persistent left superior vena cava is encountered in about 0.3 to 0.4% of human beings. It derives from remnants of the left cardinal vein system. This results in either a duplication of the superior vena cava or in a single left vena cava. The diagnosis is easy in case of associated cardiovascular anomalies. Two cases of single left vena cava and one case of duplication of the superior vena cava are described. All were identified owing to repeatedly aberrant courses of central venous catheters. Diagnosis was easily provided by angiography. Clinical course was uneventful. Despite its usual good tolerance, the persistence of a left vena cava, as an isolated anomaly, must not be neglected as it carries many practical implications which are reviewed.

[Obstructive renal lithiasis, hypercalcemia, parathyroid adenoma and term pregnancy. Report of a case]

The authors report an observation of primitive hyperparathyroidism by adenoma diagnosed at the time of a bilateral urinary lithiase, obstructive on the left, with hypercalcemia in young pregnant woman near of the term.

Perioperative cardiac complications of surgical repair of infrarenal aortic aneurysms

From 1985 to 1987, 261 patients (241 male, 20 female; mean age 66.5 years, range 38-90 years) were hospitalized for elective repair of infrarenal aortic aneurysms. One-hundred forty seven patients (56%) had coronary artery disease, attested to by past history of myocardial infarction or angina pectoris, electrocardiographic signs at rest, or abnormalities of dipyridamole thallium scintigraphy (performed in 72 patients). Ten patients had coronary arteriography and one patient then underwent aortocoronary bypass. Only two patients were not offered operation. All patients operated on had perioperative monitoring using Swan-Ganz catheters. Forty-five patients (17.5%) had a total of 62 postoperative events related to coronary artery disease. These included 40 cases of myocardial ischemia (15%), 16 cases of left heart failure (6%), and six myocardial infarctions (2%). There were nine (3.4%) postoperative deaths, four of which were due to cardiac causes (1.5%). In spite of the frequency of preexisting coronary artery disease and of intra- or postoperative myocardial ischemia, surgical repair of abdominal aortic aneurysm was not responsible for increased perioperative cardiac morbidity or mortality. In this population of aged patients, abdominal aortic aneurysm repair does not necessitate extending the indications for preoperative coronary arteriography or aortocoronary bypass.

Protective effect of a purified flavonoid fraction against reactive oxygen radicals. In vivo and in vitro study

S 5682 is a purified flavonoid fraction containing 90% diosmin (flavone derivative) and 10% hesperidin (flavanone derivative). In this study the scavenging properties of S 5682 on active oxygen radicals were demonstrated in vivo and in vitro. The activity of intravenous S 5682 was evaluated in the rat by measuring the degree of hyperglycemia provoked by an intravenous injection of alloxan, the metabolism of which produces active oxygen radicals which are toxic to B cells of the pancreas. S 5682 produced a decrease in the hyperglycemia in a dose-dependent manner (25 mg/kg and 50 mg/kg). The production in vitro of active oxygen radicals during phagocytosis by polymorphonuclear cells and macrophages is accompanied by emission of photons which can be amplified in the presence of luminol. Measurement of this chemiluminescence is a way of determining the quantity of active oxygen radicals generated in the medium, this may be reduced either by a decrease in production or by an increase in neutralisation through a reducing effect. Results demonstrated that S 5682 had a scavenging effect on active oxygen radicals for concentrations between 2 x 10(-8) mol/l and 2 x 10(-4) mol/l. The concentration of S 5682 reducing the chemiluminescence by 50% was 1.6 x 10(-5) mol/l. These scavenging properties imply that S 5682 has a pharmacological action on capillary hyperpermeability as well as an anti-inflammatory and anti-oedematous action.

Refractory metastatic breast cancer: salvage therapy with fluorouracil and high-dose continuous infusion leucovorin calcium

Sixty women with metastatic breast cancer refractory to at least one chemotherapeutic regimen were treated with fluorouracil (FUra) and high-dose continuous infusion folinic acid (leucovorin calcium). One complete remission lasting 8.7 months and nine partial remissions ranging in duration from 1.3 to 12.8 months were observed, for an objective response rate of 17% (95% confidence interval for response, 8% to 27%). Nine of the ten responding patients had metastatic disease that had objectively progressed on previous chemotherapy with a FUra-containing regimen. This program was well tolerated, with toxicities consisting mainly of stomatitis and granulocytopenia. These results suggest that augmentation of the reduced folate levels of metastatic breast carcinomas may enhance the effectiveness of the fluoropyrimidines in this disease.

Apolipoprotein B immunochemical heterogeneity in dialysed patients with chronic renal failure and patients with coronary artery stenosis

Serum cholesterol, triglyceride, apolipoprotein B (apo B) and the cholesterol and phospholipid content of apo-B-containing particles was determined in 41 male patients on dialysis for chronic renal failure, in 41 male patients with coronary artery disease selected on the basis of a total cholesterol level below 6.72 mmol/l and in 41 male control subjects of similar age. Apo B was assessed as total B protein determined using polyclonal antibodies and also by measuring the expression of epitopes recognized by three different monoclonal antibodies (BL3, BL5 and BL7). Triglyceride was increased (p less than 0.01) and cholesterol was decreased (p less than 0.01) in the dialysed patients with chronic renal failure. Total apo B was similar in the three tested groups while the expression of the BL7 epitope was increased in the group of dialysed patients with chronic renal failure (p less than 0.001). The expression of BL3 and BL5 epitopes was increased in patients with coronary artery disease (BL3: p less than 0.05; BL5: p less than 0.02) but not in dialysed patients with chronic renal failure. These results suggest an abnormal composition and an immunological heterogeneity of apo-B-containing lipoprotein particles in patients with coronary artery stenosis and in dialysed patients with chronic renal failure.

Restoration of the velocity field of the heart from two-dimensional echocardiograms

A method to quantify the motion of the heart from digitized sequences of two-dimensional echocardiograms (2-D) echos was recently proposed. This method computes on every point of the 2-D echoes, the 2-D apparent velocity vector (or optical flow) which characterizes its interframe motion. However, further analysis is required to determine what part of this motion is due to translation, rotation, contraction, and deformation of the myocardium. A method to locally obtain this information is presented. The proposed method assumes that the interframe velocity field U(xy), V(x,y) can be locally described by linear equations in the form U(x,y)=a+Ax+By; V(x,y)=b+Cx+Dy. The additional constraint was introduced in the computation of the local velocity field by the method of projections onto convex sets. Since this constraint is only valid locally, the myocardium must be first divided into sectors and the velocity fields computed independently for each sector.

[Baroreflex activity in carotid endarterectomy during general anesthesia]

The baroreceptor reflex was studied in eleven patients, aged 69 +/- 6 years, scheduled for carotid endarterectomy under general anaesthesia. Nine were hypertensive. The anaesthetic protocol was the same for all the patients: premedication with morphine and scopolamine, induction with 5 mg.kg-1 thiopentone, 6 micrograms.kg-1 fentanyl and 0.01 mg.kg-1 pancuronium bromide. All the patients were intubated and ventilated with a mixture of nitrous oxide and oxygen. Fentanyl, 100 micrograms, was routinely given at the time of incision. Baroreflex sensitivity was tested using Smyth's method, with a bolus of 75 micrograms trinitrin and plotting changes in heart rate against those in systolic blood pressure. Electrocardiogram, invasive arterial blood pressure and airway pressure were simultaneously recorded. PaCO2 and PaO2 were measured during arterial clamping. The tests were carried out before clamping, 2 min later and 10 to 20 min after the last injection of fentanyl. In the seven patients for whom clamping lasted more than 15 min, a further test was carried out after administration of 0.4 +/- 0.05 vol% halothane (Datex analyser) for 5 min. During anaesthesia, baroreflex sensitivity was low (1.8 +/- 0.3 ms.mmHg-1). After clamping, there was only a significant change in Pasys, with no changes in heart rate or blood gas values (129 +/- 8 mmHg before clamping; 167 +/- 12 mmHg after clamping; n = 8; p less than 0.01). After halothane administration, the sensitivity slope decreased, but not significantly. Moreover, halothane decreased the R-R intervals (1140 +/- 84 after clamping; 963 +/- 76 under halothane; n = 6; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement of diaphragmatic function by a thoracic extradural block after upper abdominal surgery

The effects on diaphragmatic function of a thoracic epidural block were assessed in 13 patients after upper abdominal surgery (UAS). Lung volumes and tidal changes in chest wall circumferences and gastric (delta Pgas) and esophageal (delta Pes) pressures were measured pre- and postoperatively. Volume displacement of the abdomen divided by tidal volume (delta VAB/VT) and delta Pgas/delta Pes were taken as indices of the diaphragmatic contribution to tidal breathing. These respiratory variables were obtained in the postoperative period, before and after epidural injection of 0.5% plain bupivacaine to achieve a block up to the T4 segment. UAS was constantly associated with a decrease in VT, delta VAB/VT, delta Pgas/delta Pes, and forced vital capacity (FVC). Epidural block was associated with an increase in VT, delta VAB/VT, and FVC. delta Pgas and delta Pgas/delta Pes returned to their preoperative values. It is concluded that: 1) diaphragmatic dysfunction observed after UAS is partially reversed by thoracic epidural block; and 2) that inhibitory reflexes of phrenic activity arising from the abdominal compartment (abdominal wall and/or viscera) could be involved in this diaphragmatic dysfunction.