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Biomedical subjects

P Lacroix

Publications and source records attributed to P Lacroix.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Teaching targets in vascular medicine].

The reference list presented here is a selection of educative objectives performed by the French "Collège des Enseignants de Médecine Vasculaire" for the different levels of the medical initial education course. It was produced through a collective procedure, after selecting the most relevant topics and setting up writing rules based upon docimology, and favoring practical rather than theoretical objectives. The main topics are peripheral obstructive arterial disease, polyatherosclerosis, atherosclerosis risk factors, venous thromboembolic disease, thrombophilia, chronic venous insufficiency, lymphatic insufficiency, leg ulcers, vascular acrosyndromes, cerebrovascular diseases and connective tissue diseases, vascular occupational diseases, vascular adverse effects of drugs, diabetic vascular disease, the vascular consequences of hypertension, vascular malformations and angiodysplasia, inflammatory arterial diseases, and vascular explorations. As a whole they include about 300 objectives for the five teaching levels. We hope that this list will help stimulate production of training courses and documents strongly needed in this field.

Education, Medical↗
PubMed2000

[French translation and validation of the Edinburgh Questionnaire for the diagnosis of intermittent claudication].

Obliterative arterial disease of the lower limbs is diagnosed by simple, reproducible, sensitive and non-invasive methods. One of these, a questionnaire for the diagnosis on intermittent limping, is a method of choice. Until recent years, the only validated questionnaire was the one proposed by the World Health Organisation. This was criticised a lot, especially for its lack of sensitivity. Recently, a Scottish group proposed an improvement in the diagnostic performance of this questionnaire by carrying out several changes. This new version, called the Edinburgh Questionnaire, has promising diagnostic qualities. The authors present a French version of this questionnaire. This French translation was validated in 105 patients referred for diagnosis of obliterative lower limb arterial disease. A sensitivity of 86.5%, a specificity of 95.6%, a positive predictive value of 91.4% and a negative predictive value of 92.9% of this French version are comparable to the results obtained with the English version. Therefore, the authors suggest using this questionnaire in epidemiological and public health studies in France.

Aged↗
PubMed2000

[Long-term survival of elderly amputated vascular patients].

The object of this study was to assess the 10 year outcome of patients over 70 years of age who underwent amputation for vascular diseases. The secondary objective was to determine the prognostic risk factors. One hundred and four consecutive patients having undergone a leg (16 cases) or through-thigh amputation (88 cases) were reviewed. The average age at the time of surgery was 80.7 years (+/- 6.5 years, range 70-98 years). At the time of the enquiry, there were 4 survivors (operated on average 107.7 months previously +/- 14.6 months). The survival rates at one, six, twelve months and two years were 74.1%, 48.1%, 38.5% and 27% respectively. The mean survival time was 19.2 months with a median of 6 months. Univariate analysis showed the following criteria to be statistically correlated with a poor prognosis: female gender (p = 0.008), previous psychiatric disease (p = 0.007), cachexia (p = 0.004), age of 80 or over (p = 0.025), absence of diabetes (p = 0.025). Multivariate analysis showed that men had a lower risk of death (RR: 0.591--95% CI: 0.394-0.888--p = 0.011). The comparison of subjects who died during the first year with the survivors, showed a deleterious effect of proximal amputations (p = 0.032) and absence of diabetes (p = 0.021). These results confirm the very mediocre prognosis of elderly amputated vascular patients during the first postoperative year. Thereafter, the outlook is not as bad. Female gender would seem to be a poor prognostic factor whereas the presence of diabetes could identify a subgroup with a better outlook.

Aged↗
PubMed1999

Cluster organization of the genes of Streptomyces pristinaespiralis involved in pristinamycin biosynthesis and resistance elucidated by pulsed-field gel electrophoresis.

Streptomyces pristinaespiralis synthesizes pristinamycin, a member of the streptogramin antibiotic family which consists of a mixture of two types of chemically unrelated compounds named pristinamycins I and pristinamycins II. In order to estimate the size of the Strep. pristinaespiralis chromosome and to elucidate the organization of the pristinamycin biosynthetic and resistance genes already identified, it was decided to use the pulsed-field gel electrophoresis technique. Results indicate that the Strep. pristinaespiralis chromosome is linear and about 7580 kb, as previously shown for several other Streptomyces species. By hybridization, it could be shown that the biosynthetic and resistance genes for pristinamycins I and pristinamycins II, except for the multidrug resistance gene ptr, are interspersed and seem to be organized as a single large cluster, covering less than 200 kb corresponding to 2.6% of the total size of the chromosome. The consequences and significance of such a genetic organization are discussed.

Journal Article↗
PubMed1999

Sleep apnoea syndrome and the extent of atherosclerotic lesions in middle-aged men with myocardial infarction.

BACKGROUND: To determine whether extended atherosclerotic lesions are correlated to the presence of sleep breathing disorders. METHODS EXPERIMENTAL DESIGN: A prospective clinical study. SETTING: A tertiary regional referral center. PATIENTS: 40 male patients < or =65 years consecutively admitted to the cardiac care unit for an acute myocardial infarction with serous creatinine phosphokinase (CPK) > or =350 IU/l and a CPK-MB fraction > or =10%. Exclusion criteria were: cardiac surgery on emergency, stroke, major neurological and/or psychiatric disturbances, alcohol consumption >50 g/day, toxicomania, clinical or biological hypothyroidism, clinical acromegaly and chronic obstructive pulmonary disease. MEASURES: Duplex ultrasonography was performed on carotid arteries, femoral arteries and their bifurcations. An overnight polysomnography was performed after hospital discharge. Patients with an apnoea index >5/hour or apnoea-hypopnea index >10/hour of sleep are considered to have sleep apnoea syndrome (SAS). Patients with additive peripheral atherosclerotic lesions are compared to patients with normal carotid and femoral arteries, regarding to standard cardiovascular risk factors and apnoeas or hypopnoeas during sleep. RESULTS: Duplex revealed in 18 patients carotid and/or femoral atherosclerotic lesions. The prevalence of SAS in patients with at least one peripheral arterial lesion was significantly higher (61% vs 18%, p<0.01). A nearly significant difference was also noted in patients with carotid lesions alone compared to those with normal carotid arteries (57% vs 27%, p=0.06). CONCLUSIONS: These results suggest a possible link between sleep breathing disorders and the pathogenesis of atherosclerotic lesions.

Aged↗
PubMed1999

[Ischemic neuropathy in occlusive lower limb arterial disease at the state of ischemia on effort].

Acute or chronic prolonged ischaemia of the limbs may cause lasting neurological damage. This has been shown in clinical, electrophysiological and anatomopathological studies. The aim of this study was to search for signs of neurological suffering during ischaemia of effort. Twenty patients with occlusive lower limb arterial disease with ischaemia of effort were studied. None of the patients had other causes of neuropathy: none of the patients had potentially neurotoxic therapy. All underwent haemodynamic assessment (Doppler ultrasonography treadmill test, transcutaneous oxygen diffusion) and electrophysiological study (nerve conduction studies and an electromyogramme). Ten patients had abnormalities during stimulation-detection and on electromyography. These abnormalities were always observed in the limbs with the poorest blood flow. The pressure index and transcutaneous oxygen diffusion in lying position were significantly lower (pressure index: 0.43 vs 0.72, p < 0.03; TcPO2: 20.3 vs 27.2, p < 0.04). The authors consider that effort ischaemia is associated with neurological damage. Repeated transient episodes of ischaemia could cause neuropathy.

Adult↗
PubMed1998

Diagnosis and management of entrapped embolus through a patent foramen ovale.

The diagnosis of impending paradoxical embolus by echocardiography is exceptional and its management remains unclear. Through a personal case, we performed an exhaustive review of the medical literature of this rare finding. Since the first report, only 43 cases have ever been reported. The superiority of transesophageal echocardiography is underlined. The clinical features are complex. The classical simultaneous pulmonary and paradoxical embolism is often absent. Therapeutic options are cardiac surgery, thrombolysis or anticoagulation. The early mortality rate is high (21%). In addition, recurrent embolisms are reported when a medical treatment is chosen. The cumulative results of each possibility are described.

Aged↗
PubMed1998

[Predictive factors of smoking cessation after myocardial infarction. Review of the literature].

This paper reviews the current state of knowledge about smoking after myocardial infarction in smokers. After presenting results emphasizing the value of post-infarction smoking cessation, all of the predisposing factors to smoking cessation are analysed. The objective of this review of the literature is to recognize these factors in order to more precisely define the various medical, psychological and social aspects of an assistance programme adapted to post-infarction smoking cessation.

Health Knowledge, Attitudes, Practice↗
PubMed1997

[Raynaud syndrome complicated by digital gangrene during treatment with interferon-alpha].

In a 43-year old male suffering from idiopathic hypereosinophilic syndrome (HES) since 1984, successfully treated with alpha interferon (alpha IFN) for 32 months, a severe Raynaud's phenomenon of the four extremities occurred and eventually evolved into digital necrosis within a few weeks. The arterial echography/doppler and plethysmography patterns were suggestive of isolated small-to medium-size digital artery occlusions. An extensive search for an aetiology of digital necrosis, including complete tests of autoimmunity, remained negative. Two months later, despite alpha IFN withdrawal and intravenous infusions of ilomedin, the digital ischemia evolved to extensive necrosis that necessitated several amputations and a definitive spinal chord stimulation. Pathologic examination of arteries showed no vasculitis but diffuse arterial occlusions by thrombi.

Adult↗
PubMed1997

Obtaining maximal use of expanded scalp rotation flaps via an experimental model.

The relative inelasticity of scalp skin and the irregular convexity of the cranial vault necessitate careful planning in the design and mobilization of scalp flaps. Rotation flaps adapt particularly well to the curves of the cranial vault. An experimental model has enabled us to study the design and mobilization of expanded scalp rotation flaps and to obtain maximal efficiency from the tissue expansion process. The use of a round tissue expander situated immediately adjacent to a scalp defect is an excellent method for the creation of a rotation flap. To optimize the use of the expanded tissues, the flap should be designed so that its border passes along the periphery of these expanded tissues. In cases in which it is advisable to separate the expander from the defect, such as when the defect is highly contaminated, efficient use of the expanded tissues can still be obtained by placing the expander at the site of a rotation flap backcut. Furthermore, although this study focuses on rotation flaps only, this same model can be used to examine and compare different closure methods using other types of flaps as well.

Child, Preschool↗
PubMed1997

S 15535, a novel benzodioxopiperazine ligand of serotonin (5-HT)1A receptors: I. Interaction with cloned human (h)5-HT1A, dopamine hD2/hD3 and h alpha2A-adrenergic receptors in relation to modulation of cortical monoamine release and activity in models of potential antidepressant activity.

The novel, potential anxiolytic, S 15535 (4-(benzodioxan-5-yl)1-(indan-2-yl)piperazine), is an agonist and antagonist (weak partial agonist) at pre- and postsynaptic serotonin (5-HT)1A receptors, respectively. Herein, we characterized its influence on dialysate levels of 5-HT, dopamine (DA) and NAD simultaneously determined in single samples of the frontal cortex (FCX) of freely moving rats, and compared its activity in several other models of potential antidepressant (AD) properties with those of the 5-HT reuptake inhibitor (SSRI), fluoxetine. S 15535 displayed high affinity at cloned human (h) 5-HT1A receptors (Ki = 0.7 nM) and >250-fold lower affinity at cloned hD2 (400 nM), hD3 (248 nM) and h alpha2A-adrenergic (AR) (190 nM) receptors. S 15535 (0.08-5.0 mg/kg s.c.) markedly and dose-dependently suppressed dialysate levels of 5-HT in the FCX, nucleus accumbens and striatum of freely moving rats, whereas fluoxetine (10.0 mg/kg s.c.) elevated levels of 5-HT in each structure. In contrast to 5-HT, dialysate levels of DA and NAD in the FCX were dose-dependently increased by S 15535, and this effect was mimicked by fluoxetine. The influence of S 15535 and fluoxetine on FCX levels of DA was regionally specific inasmuch as dialysate levels of DA in the accumbens and striatum were not modified. The selective 5-HT1A antagonist, WAY 100,635 (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexanecarboxamide (0.16) transiently elicited a slight increase in cortical levels of 5-HT, an action opposite to that of S 15535. Further, in the presence of WAY 100,635 (0.16), the influence of S 15535 (0.63) on cortical levels of 5-HT, DA and NAD was markedly attenuated. Upon chronic administration of S 15535 or fluoxetine (10.0 mg/kg s.c. daily for 14 days, in each case), there was no significant alteration in the density of beta-AR receptors in the FCX. However, in contrast to fluoxetine, S 15535 elicited a significant (25%) decrease in the density (Bmax) of 5-HT2A receptors labeled by [3H]ketanserin in the cortex; there was no alteration in Kd. In a learned helplessness paradigm in rats, S 15535 (0.63-40.0 mg/kg p.o.) markedly reduced escape deficits on each of three consecutive days of testing. Fluoxetine (2.0-8.0 mg/kg i.p.) was also active in each session, but presented a biphasic dose-response curve. Finally, under the conditions used, neither S 15535 (0.63-10.0) nor fluoxetine (0.63-10.0) decreased immobility time in the forced swim test. In conclusion, S 15535 is a selective ligand of cloned, h5-HT1A receptors. Its agonist actions at 5-HT1A autoreceptors underlie its ability to decrease extracellular levels of 5-HT in the FCX, and likely contribute to the increase in extracellular levels of DA and NAD evoked by S 15535 in this structure. Further, S 15535 is active in several other, although not all, models of potential AD activity. Thus, although S 15535 is under development as an anxiolytic agent, a further characterization of its putative AD actions would be of interest.

Animals↗
PubMed1997

M-CSF serous rate evolution during post-transplantation days in a heterotopic heart graft model mice.

BACKGROUND: On heterotopic heart graft in mice, aged 7 weeks (C3H and B57), we investigate the variations of Macrophage Colony stimulating factor serous rate. The macrophage colony stimulating factor (M-CSF) is a cytokine involved in the immune response during transplantation. METHODS: Five groups were determined, group 1 with a heterotopic transplant without immunosuppressive treatment (N=24); group 2 with a heterotopic transplant and Corticoid treatment after the graft (N=29); group 3 with a heterotopic transplant and cyclosporine treatment after the graft (N=34); group 4 with an isogenic transplant (N=31) and group 5 undergoing a laparotomy (N=31). The mice are sacrificed at D4, D7, D10 or D14 and the M-CSF dosage are done by ELISA method. RESULTS: The serous rate of M-CSF is stable in the group with an isogenic transplant or with only a laparotomy. But in the group with a heterotopic transplant the M-CSF values increase (x1.5). If we use an immunosuppressive treatment the raising of M-CSF is less important. When we have a rejection graft, the serous rate of M-CSF increases but not significantly (Mann-Whitney test). CONCLUSIONS: We conclude M-CSF seems to be a reliable index of disorder during immune response, but is not a good marker of the rejection.

Animals↗
PubMed1996

Effects of dimethylformamide on in vivo fatigue and metabolism in rat skeletal muscle measured by 31P-NMR.

Dimethylformamide (DMF) is widely used as an industrial solvent in spite of well-established hepatotoxicity and adverse effects on in vitro muscle contractility. The doses used in the studies describing these effects were higher than the doses required to solubilize drugs to be injected at very low levels and the potential effects of DMF at very low levels has not yet been explored. The goal of this work was to study the effects of an acute, low dose of DMF (3 mu/100 g body weight, administered i.p.) on mechanical parameters and energy metabolism of contracting rat skeletal muscle. Metabolic changes were followed by 31P nuclear magnetic resonance spectroscopy. Tension was significantly lower during the fatigue test in DMF-treated rats than in controls. Phosphomonoesters and inorganic phosphorus level were lower, and intracellular pH was higher in DMF-treated rats than in controls, showing that energy metabolism was activated to a lesser degree, in relation with the lower mechanical performance, after DMF. Skeletal muscle is a target organ for dimethylformamide which has a major effect on muscle contractility by decreasing the tension developed. The effects of DMF suggest that it is unsuitable for use as a drug vehicle for in vivo injections, even at a very low nonhepatotoxic doses.

Animals↗
PubMed1996

Renal infarction and thrombosis of the infrarenal aorta in a 35-year-old man with primary antiphospholipid syndrome.

Renal manifestations of the "primary" antiphospholipid syndrome are rare. We report the case of an athletic 35-year-old man with an unremarkable medical history who suddenly developed hypertension and a renal infarction. Laboratory and radiological investigations showed a complete thrombosis of the infrarenal aorta, extensive collateral circulation arising from the superior mesenteric artery, and the primary antiphospholipid syndrome. Eight cases of renal infarction have previously been reported in the primary antiphospholipid syndrome. To our knowledge, this represents the first case of an infrarenal aortic thrombosis attributable to this syndrome.

Adult↗
PubMed1996

[Paraneoplastic arterial thrombosis. Apropos of 2 cases].

The search for a cancer is part of the classical investigation of unexplained venous thrombosis. Arterial thrombosis associated with neoplasia is more rare. The authors report two cases in which arterial thrombosis was the final event of their malignant disease. The first case had abacterial thrombotic endocarditis and disseminated intravascular coagulation at the origin of multiple thrombotic complications. The initially unknown cancer was a pancreatic adenocarcinoma. The second case presented with acute occlusion of the iliac artery after ablation of a malignant melanoma. Despite embolectomy with a Fogarty catheter and effective anticoagulation, the thrombosis recurred several times at the same site. The clinical features and the mechanisms of these two cases suggestive of Trousseau's syndrome are discussed.

Adenocarcinoma↗
PubMed1996

[Postoperative transparietal Doppler ultrasonographic study of the internal mammary artery graft flow with respect to quality of the underlying myocardium].

The authors studied flow in the internal mammary artery by Doppler ultrasonography after bypass surgery of the left anterior descending artery to determine the correlation between the flow pattern and the quality of the distal run off. A pulsed Doppler was used to record flow from the right and left internal mammary arteries in the first, second and third intercostal spaces and the supraclavicular fossa. Only the best quality recordings with the highest amplitudes were retained for analysis. Forty-nine patients (average age 61 +/- 10 years), 43 men and 6 women, were included and were examined between the 10th and 15th postoperative days. All had stenosis of the left anterior descending on coronary angiography: three subgroups were identified ad the time of evaluation: (I) revascularisation of an infarcted zone with important angiographic and echographic sequellae. (II) revascularised zones with slight wall motion abnormalities. (IIIa) revascularisation of myocardium with no abnormality (including a subgroup of 5 patients (IIIb) characterised by a postoperative low output state and echocardiographic changes not present before surgery). Significant changes were observed in the flow patterns of the different groups. (I) an exclusively systolic flow (diastolic velocity time integral = 2.85 cm), (II) systolodiastolic flow (diastolic velocity time interval = 9 cm) similar to that in group IIIb, and IIIa predominantly diastolic flow (diastolic velocity time integral = 15.2 cm). The amplitude of diastolic flow in the mammary artery graft was therefore related to previous ischaemia of the revascularised myocardium; detection of stenosis by Doppler ultrasonography should therefore take into account the previous history of the patient.

Adult↗
PubMed1995

Cloning and analysis of structural genes from Streptomyces pristinaespiralis encoding enzymes involved in the conversion of pristinamycin IIB to pristinamycin IIA (PIIA): PIIA synthase and NADH:riboflavin 5'-phosphate oxidoreductase.

In Streptomyces pristinaespiralis, two enzymes are necessary for conversion of pristinamycin IIB (PIIB) to pristinamycin IIA (PIIA), the major component of pristinamycin (D. Thibaut, N. Ratet, D. Bisch, D. Faucher, L. Debussche, and F. Blanche, J. Bacteriol. 177:5199-5205, 1995); these enzymes are PIIA synthase, a heterodimer composed of the SnaA and SnaB proteins, which catalyzes the oxidation of PIIB to PIIA, and the NADH:riboflavin 5'-phosphate oxidoreductase (hereafter called FMN reductase), the SnaC protein, which provides the reduced form of flavin mononucleotide for the reaction. By using oligonucleotide probes designed from limited peptide sequence information of the purified proteins, the corresponding genes were cloned from a genomic library of S. pristinaespiralis. SnaA and SnaB showed no significant similarity with proteins from databases, but SnaA and SnaB had similar protein domains. Disruption of the snaA gene in S. pristinaespiralis led to accumulation of PIIB. Complementation of a S. pristinaespiralis PIIA-PIIB+ mutant with the snaA and snaB genes, cloned in a low-copy-number plasmid, partially restored production of PIIA. The deduced amino acid sequence of the snaC gene showed no similarity to the sequences of other FMN reductases but was 39% identical with the product of the actVB gene of the actinorhodin cluster of Streptomyces coelicolor A(3)2, likely to be involved in the dimerization step of actinorhodin biosynthesis. Furthermore, an S. coelicolor A(3)2 mutant blocked in this step was successfully complemented by the snaC gene, restoring the production of actinorhodin.

Amino Acid Sequence↗