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Biomedical subjects

D Garnier

Publications and source records attributed to D Garnier.

At least 55 records · Page 3Linked to original sources
PubMed1989

[Cutaneous microvascularization after tissue expansion: experimental study in rats. Proposal of a method for monitoring the expansion by measuring the transcutaneous pressure of oxygen].

Major complications can occur during cutaneous expansion. They appear to be related to microcirculatory disorders. An experimentation in the rat demonstrated a significant difference in the results depending on the protocol adopted (slow or rapid expansion). Complications occurred in the case of rapid expansion. The results for TcPO2, histology and capillaroscopy corroborate the clinical data. The authors show that measurement of the TcPO2 has a predictive value in relation to complications. They propose the use of this technique in human clinical practice. The TcPO2 and the cutaneous oxygenation index allows control of tissue expansion in order to prevent the development of complications.

Animals↗
PubMed1989

[Pulmonary embolism and disseminated intravascular coagulation after being bitten by a Bothrops lanceolatus snake. Apropos of a case].

The authors report the case of a Bothrops lanceolatus snake bite complicated by severe pulmonary embolism a few hours after admission. This thromboembolic complication developed despite heparin therapy and was followed by disseminated intravascular coagulation (DIC). Vascular thrombosis and pulmonary embolism are rare after Bothrops lanceolatus snake bite as patients are usually hypocoagulable due to DIC. In this case, the thromboembolism was probably caused by the procoagulant effect of the thrombin-like enzymes of the snake venom which may have been injected directly into the vein of a young woman taking a contraceptive pill. A specific antivenin which has recently become available fort treatment may decrease the complications of Bothrops lanceolatus snake bite.

Adult↗
PubMed1989

[Left ventricule function and sickle-cell anemia. Echocardiographic study].

The dimensions of the cardiac chambers and left ventricular function were studied by echocardiography in 40 patients with homozygous sickle cell disease (SS) and 25 patients with heterozygous sickle cell trait (12 AS, 10 SC, 3 BS) and compared with the same parameters in 30 normal subjects. Patients with homozygous SS disease had significantly larger left atrial (32.2 +/- 6.47 mm vs 26.62 +/- 5.64 mm; p less than 0.001), left ventricular (46.4 +/- 8.49 mm vs 39.97 +/- 5.29 mm; p less than 0.001) and right ventricular (17.95 +/- 5.08 mm vs 15.5 +/- 3.17 mm; p less than 0.02) dimensions: they also had higher indexed myocardial surfaces (11.48 +/- 2.36 cm2/m2 vs 8.21 +/- 1.97 cm2/m2; p less than 0.001) and indexed end diastolic left ventricular volumes (101.84 +/- 22.74 ml/m2 vs 65.05 +/- 10.81 ml/m2; p less than 0.001), a higher cardiac index (4.77 +/- 1.33 l/mn/m2 vs 3.58 +/- 1.08 l/mn/m2; p less than 0.001) and stroke volume (71.77 +/- 32.86 ml vs 49.56 +/- 13.39 ml; p less than 0.001). Peripheral resistances were significantly lower (1341 +/- 469 vs 1626 +/- 368 dynes/s/cm-5; p less than 0.01) as were the velocities of circumferential fibre shortening (VCF) (1.11 +/- 0.20 circ/s vs 1.28 +/- 0.24 circ/s; p less than 0.01). Two thirds of homozygous SS disease patients (27/40) had appearances of an anaemic heart with eccentric left ventricular hypertrophy, normal left ventricular systolic function, an increased cardiac index (5.01 +/- 1.19 l/mn/m2) and low peripheral arterial resistances.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

[Congenital diverticulum of the right ventricle apropos of a case complicated by pulmonary endocarditis].

Congenital diverticulum of the right ventricle is an extremely rare abnormality, usually discovered by chance during evaluation of a more complex cardiac malformation. We report a case of isolated diverticulum of the right ventricle in a 14-year old boy who also had pulmonary valve endocarditis secondary to acute osteomyelitis. Owing to the evolutive risks inherent in the diverticulum and to the persistence of highly mobile pulmonary valve vegetations 5 years after the initial infectious episode, surgical treatment of the lesions had to be performed. The diagnostic, evolutive and therapeutic problems raised by right ventricular diverticula are discussed.

Child↗
PubMed1987

[Acetylcholine and the myocardium: electrophysiological aspects].

The cardiac inhibitory effects (negative inotropic and chronotropic) of muscarinic cholinergic stimulation by acetylcholine (ACh) are well established. They are due to electrophysiological modifications involving (1) the activation of the resting K+ channel showing inward going rectification properties; (2) the reduction of the inward calcium current (I Ca). Recent works on isolated myocardial cells allowed to investigate the molecular mechanisms involved between muscarinic cholinergic receptors activation and effector (the ionic channel). The results indicate that muscarinic receptor communicates with the K+ channel, via GTP-binding protein (Ni, o or G) and that does not involve adenylate-cyclase. In contrast to the direct muscarinic activation of K+ channel, ACh decreases I Ca by inhibiting, via Ni, the cAMP production. The inhibition of I Ca is larger in the beta-stimulated cells.

Acetylcholine↗
PubMed1985

Photochemically produced intracellular concentration jumps of cAMP mimic the effects of catecholamines on excitation-contraction coupling in frog atrial fibers.

Previously, we reported that concentration jumps of cAMP produced by light flashes in the presence of a photosensitive analogue of cAMP increase the amplitude of the slow inward current (Isi) in isolated bullfrog atrial trabeculae (Nargeot et al. 1983). Here, using newly designed photolabile cyclic nucleotides (Nerbonne et al. 1984a), we have examined the effects of intracellular concentration jumps of cAMP and cGMP on excitation-contraction coupling in frog heart. Concentration jumps of cAMP increase the amplitude and the duration of action potentials, increase Isi and twitch tension. Following single flashes, maximum responses are observed in 10-30 s and recovery times are 30-120 s. The time courses of the cAMP-induced increases in Isi and phasic tension amplitudes are parallel, implying a direct correlation between Ca2+ influx through the slow channels and the development of phasic tension. Although the amplitudes are increased severalfold, cAMP jumps do not measurably alter the kinetics or voltage dependences of the current or tension. cAMP concentration jumps increase the delayed K+ current (IK) and decrease tonic tension; relaxation of contraction is not, however, influenced by cAMP jumps. Concentration jumps of cGMP, on the other hand, have no measurable effects on the action potential, Isi, IK or tension in this preparation.

Action Potentials↗
PubMed1985

[Changes in levels of plasma fibronectin after surgery for digestive cancer].

Fibronectin is a large, adhesive glycoprotein, also called opsonic alpha 2 surface-binding glycoprotein. This glycoprotein which participates in all adhesions may modulate wound healing; plasma fibronectin, because it is opsonically active, may mediate reticulo-endothelial activity. Citrated plasma samples were analysed from twenty surgical patients with digestive cancer. The samples were obtained preoperatively and on 1st, 3rd, 7th, 14th and 28th postoperative days. Fibronectin assay was made by laser immunonephelometry. Other samples were obtained from a population of 340 healthy male and female subjects whose age ranged from 10 to 70 years, so that reference could be made to the standard mean of fibronectin related to the age of each patient. In the surgical patients, there was a significant decrease in fibronectin from the first to the third postoperative day. On the 7th day, there was a secondary increase of fibronectin levels which exceeded the preoperative values at the 14th and 28th days. There was no plasma dilution when the samples were collected, this being shown by protidaemia, osmolarity and haematocrit which were measured at the same time. "Septic" and "non septic" patients were compared. For septic patients, fibronectin levels were lower and the secondary increase occurred later than in the non septic patients. Patients with no secondary increase did not recover and died. Fibronectin levels were compared with other classical parameters of nutritional assessment, i.e. albumin, prealbumin, transferrin and urinary creatinine indexes. These parameters were not well correlated. However, this study may indicate the usefulness of fibronectin as an indicator of nutritional status and of non specific host defence.

Aged↗
PubMed1985

Vasoactivity of trimetazidine on guinea-pig isolated ductus arteriosus.

The effect of trimetazidine (TMZ), an anti-anginal drug, on the mechanical response of the guinea-pig ductus arteriosus placed under conditions of mild hypoxia (PO2 approximately equal to 75 mmHg) was investigated. When the PO2 of the bathing solution was 75 mmHg, TMZ caused a dose-dependent increase in tension. The median effective dose (ED50) for the drug was 8 X 10(-5)M. TMZ-induced increase in tension was not significantly affected by pretreatment of the preparation with adrenoceptor blocking agents, or indomethacin. The amplitude of the PO2-dependent tension was significantly augmented by exposure of the strip to TMZ 10(-4)M, whereas neither the resting tone (low PO2), nor the oxygen-induced contraction (high PO2) were altered. This ability of TMZ to increase the tension response during hypoxia was dependent on the external calcium concentration. Under low PO2 conditions, a contractile activity of 10(-4)M TMZ was unmasked in preparations perfused with 18 mM K+-PSS medium. This response to TMZ disappeared after the removal of calcium from the bath. At the maximally effective dose of 10(-3)M, and during low PO2, the TMZ-induced contractile response changed to a relaxation response when the external K+ concentration was raised more than five fold. The possibility that TMZ stimulates the mechanism by which oxygen normally controls the concentration of free intracellular calcium in the ductus arteriosus is proposed.

Animals↗
PubMed1984

Dynamic changes in plasma luteinizing hormone and testosterone after stress in the male rat. Influence of adrenalectomy.

In 60-day old intact male rats, stress imposed by a strange environment increased the levels of plasma LH and testosterone. Adrenalectomy, performed at 50 days of age, decreased plasma level of testosterone in basal conditions. However, without affecting the plasma level of LH significantly, stress increased plasma testosterone, albeit to a lesser extent, in the adrenalectomized rats. Stimulation of the testicular secretion by the high level of ACTH seems to be the most likely explanation for the observed testosterone peak in the adrenalectomized rat.

Adrenalectomy↗
PubMed1983

[Localized tetanus after esophagogastrectomy].

Post-operatory partial tetanus is a more and more rare event. It can outcome after any type of surgery but especially after abdominal surgery. The contamination is usually endogenous through the digestive bacteria and it develops in anaerobic context. These different factors were united in this report. The diagnosis is difficult if not keep in mind. The treatment is usual, but prevention might be pointed out.

Esophagus↗
PubMed1983

[Anticipation of surgical results in calcified aortic stenosis as a function of age].

The effects of age on the risks and results of heart valve replacement are often discussed in aortic stenosis, a degenerative condition of elderly patients. We assessed this factor in a study based on two groups of patients operated consecutively between 1968 and 1980. Group A comprised 127 patients of over 65 years of age (range 66 to 79 years, mean 70 +/- 3 years), and Group B: 259 patients of less than 65 years of age (21 to 65 years, mean 53 +/- 9 years). Preoperative assessment showed a higher proportion of women and significantly more severe lesions in Group A: a greater number of patients in functional class 3 or 4, cases of congestive cardiac failure, greater cardiac volumes, lower cardiac index. The incidence of coronary artery disease was also higher. A greater number of aortic valve bioprostheses was used in Group A. Operative mortality was significantly higher in Group A (15 p. 100, compared to 6 p. 100 in Group B: p less than 0.01). The influence of age was independent of other risk factors as shown by a multifactorial analysis taking several prognostic factors into account simultaneously. Long term survival was significantly lower in Group A, but their life expectancy did not differ from that of a control group. The causes of postoperative or late death were the same in both groups. At the end of the 6th year, 66 p. 100 of the survivors of surgery in Group A were in functional classes I or II compared to 77 p. 100 in Group B (NS). These results justify this type of surgery in elderly patients, even at advanced stages of their disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1982

Identification of N- and C-terminal corticotropin peptides in the Mr 80000 form of neurophysin.

The 125I-labeled Mr 80000 form of neurophysin has been purified from bovine neurohypophysi. Tryptic digests of this species were analyzed, prior to or after treatment with carboxypeptidase B, by high-pressure liquid chromatography followed by isoelectric focusing and the fragments compared with those generated by a similar treatment of reference bovine 1-39 adrenocorticotropin. The ACTH peptides 22-39 and 1-8, as well as the 1-7 derivative of the latter were identified by those two independent criteria. This provides chemical evidence supporting the hypothesis [8] that high Mr neurophysin may contain the sequence of ACTH.

Adrenocorticotropic Hormone↗
PubMed1981

Analysis of the negative inotropic effect of acetylcholine on frog atrial fibres.

Voltage-clamp experiments have been performed on frog atrial preparations in order to study the mechanism of the inotropic effect of acetylcholine (ACh) at various concentrations. The amplitude of the slow inward current (Is) is reduced even at low ACh concentrations; such low concentrations have little or no effect on potassium permeability. Dose-effect relationships for Is inhibition (Is/Is max) by ACh show a half amplitude dose (K0.5 around 8 X 10(-8) M ACh. The reduction of Is is attributed largely to a decrease of the maximal conductance of the slow channel (gs). Steady-state activation and inactivation parameters are not affected by ACh. Experiments in a Na-free solution (Na replaced by Li ions) or in a Ca-free solution (with EGTA) indicate that the "slow sodium current" is more sensitive to ACh than the "slow Ca current", although these two currents both seem to flow through the slow channel. The decrease of the phasic component of contraction observed in the presence of ACh is very well correlated with the decrease of Is (K0.5 = 8 X 10(-8) M ACh), while the increase of the tonic tension may be related to the outward potassium current induced by high concentrations of ACh. The significant difference between the half amplitude dose (K0.5) observed in the dose effect curves with ACh for Is inhibition (K0.5 = 8 X 10(-8) M) and for ACh-induced extra-current (K0.5 - 10(-6) M) may indicate the presence of two muscarinic receptors.

Acetylcholine↗