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Biomedical subjects

S Gaillard

Publications and source records attributed to S Gaillard.

At least 55 records · Page 3Linked to original sources
PubMed1997

[Acquired hemophilia caused by autoantibodies against factor VIII coagulation activity. Clinical, biological study and therapeutic indications. Experience based on a study of 9 cases].

STUDY DESIGNS: To describe retrospectively the experience of the Internal Medicine and Clinical Hematology Departments of a University Hospital on adult acquired hemophilia (AH) caused by autoantibody against factor VIII coagulant (f.VIII:C) activity. Diagnosis, clinical datas, associated diseases, treatment and final outcome are described and compared to the published literature. MATERIAL AND METHODS: All cases admitted in both departments since 1989 were enrolled in the study. Clotting analyses comprised clotting times (activated partial thromboplastin time, prothrombin and thrombine times), measurements of f.VIII:C level, antifactor VIII detection and measurement by the Bethesda method assay, Search for an etiologic factor could not be standardized. All patients were followed until cure, sustained improvement, or death. RESULTS: From 1989 to 1996, AH was diagnosed in nine adult patients. Mean age was 76 +/- 24.6 years (range : 65-89) and sex ratio male to female was 2. Eight bleeding episodes occurred in seven patients, resulting consistently in severe hemorrhagic anemia and leading to hemodynamic failure in two, while two others remained asymptomatic for prolonged periods. The initial levels of f.VIII:C ranged from less than 1% to 20%, and the titers of inhibitors ranged from 0.5 to 100 Bethesda units. An underlying disease, to which the appearance of their inhibitor could be related, either concomitantly or up to 1 year later, was found in four cases including (one case each): rheumatoid arthritis, lupus erythematosus with antiphospholipid syndrome, followed by non-Hodgkin malignant lymphoma, relapsing carcinoma and, biliary tract surgery. Six acute bleeding episodes necessitated symptomatic measures, based on activated prothrombin complex concentrates in four instances, with a good response in all cases. Preparation to minor surgical operations was achieved in two asymptomatic subjects by either highly purified factor VIII concentrations infusion or intravenous 1-desamino-8-D-arginine vasopressin, with a good control of local hemostasis in each case. Three received intravenous immunoglobulins, which resulted in success in one, failure in one and, questionable response in the latter. Immunosuppression, mainly with corticosteroids, cyclophosphamid, or both, was given to seven, resulting in disappearance of inhibitor in five (delay to cure ranged from 2 weeks to 10 months), improvement in one, and failure in one (in this latter case, cure was eventually achieved with the anti-Hodgkin disease MOPP chemotherapy). After a 27-month mean follow-up, six patients experienced a sustained complete response and one a sustained partial response to immuno-suppression, two untreated patients remained asymptomatic, two died later from malignancy (carcinoma and myelodysplastic syndrome). CONCLUSION: AH usually presents as a severe or even a life-threatening disease, necessitating prompt and thorough symptomatic measures directed at the cessation of bleedings and prevention of their relapse. In our experience, no death was attributable to AH or its treatment. Immunosuppression is useful in selected cases, but must be carefully discussed, since it can be highly toxic, especially in the elderly. Given the possibility of a delayed onset of some etiologic factors, a prolonged surveillance of each case of idiopathic AH is mandatory.

Aged↗
PubMed1997

[Sacral nerve root cysts. Discussion on the mechanism of nerve root suffering. Apropos of 4 cases].

Low back pain, sciatia or perineal chronic pain are sometimes related to perineural sacral cysts. Surgical treatment is difficult and may lead to pain or neurological worsening. We report four cases of symptomatic perineural cysts; three of them where operated on with two good results and one increasing perineal pain. Anatomical and radiological description are reviewed. From a therapeutical point of view, we can distinguish two clinical types of radicular suffering. Perineural cyst can cause a commun radicular extrinsic compression; in such a case surgical operation will improve radicular pain. The cystic nerve root can present an intrinsic suffering because of on intradural dilaceration. Then surgery must be avoided specially when many roots are involved because it may worsen the pluriradicular suffering.

Adult↗
PubMed1997

[Value of peroperative endoscopy in treating giant lumbosacral meningocele].

Lombosacral meningocele may be responsible for sciatica, low backache, cauda equina syndrome according to their localization and size. When they are symptomatic, the surgical purpose is to close the communication between the meningeal sac and the cyst. For giant meningocele, acute localization of the communication may be difficult. In such cases, peroperative endoscopy may be useful. We present a case of sciatica related to a giant meningocele extended from L2 to S2. MRI, CT scan and myelography were unable to localize the communication. We used peroperative endoscopy for direct visualization of the communication in order to minimize the surgical approach. An intrathecal nerve root was found strangulated in the communication suggesting an original kind of nerve root suffering. The communication was only closed. The patient made an uneventful recovery with complete relief of symptoms. Magnetic resonance imaging 3 months later showed a significant decrease of the meningocele without any further radicular compression.

Adult↗
PubMed1996

Intracellular acidification mediates the proliferative response of PC12 cells induced by potassium ferricyanide and involves MAP kinase activation.

Potassium ferricyanide is known to elicit cell growth and mitogenesis in various cells by stimulating a transplasma membrane electron-transport system. When serum-starved PC12 cells were treated with potassium ferricyanide, stimulation of mitogenesis was evidenced by enhanced DNA synthesis, as well as by increased cell numbers. Intracellular pH (pH(i)) of PC12 cells was measured at 37 degrees C by microfluorimetric analysis of 2',7'-bis-(2-carboxyethyl)-5(and -6)-carboxyfluorescein (BCECF). The resting pH(i) of unstimulated cells was 7.52 (external pH 7.40). Addition of potassium ferricyanide (100 microM) decreased pH(i) by about 0.25 pH units. Lowering pH(i) to a similar extent, either by decreasing external pH (pH(o)) or by adding a weak acid, also elicited a mitogenic response, indicating that intracellular acidification by itself has growth factor-mimicking, mitogenic effects. Nerve growth factor (NGF) or basic fibroblast growth factor (bFGF) triggered proliferation without changes in pH(i). The mitogenic treatments eliciting intracellular acidification did not activate protein kinase C (PKC) but stimulated the p42/p44 mitogen-activated protein (MAP) kinase. Our results indicate that 2 distinct mitogenic pathways are active in PC12 cells: the first is independent of pH(i) and involves activation of the PKC pathway and the second requires a permissive pH(i) value around 7.25 and involves activation of the p42/p44 MAP kinase pathway.

Animals↗
PubMed1996

Evaluation of a hydrocolloid dressing.

A hydrocolloid dressing was compared to adhesive skin tapes on children's postoperative wounds. A total of 170 children of varying ages were randomised in two parallel groups, in nine centres of plastic, thoracic, gastrointestinal, urogenital and orthopaedic surgery. Skin closure was satisfactory in both groups, with 76 (89.4%) healthy closures without dehiscence in the hydrocolloid group and 81 (95.3%) in the control group; a relationship was found between partial closures/dehiscence and the type of surgical procedure. No product-related maceration, infection or adverse event was reported during the study and both groups showed very satisfactory cosmetic results.

Adhesives↗
PubMed1995

Voltage-gated ionic currents in mature oligodendrocytes isolated from rat cerebellum.

Mature rat cerebellar oligodendrocytes were isolated in culture using a serum free medium and identified using anti-galactocerebroside (GalC) and OL-1 antibodies. The morphology of such oligodendrocytes changes with time in culture from a multipolar shape at about 4 days in vitro (DIV) to a monopolar shape at about 8 DIV, a transition that has been previously described only in situ. Voltage-gated ionic currents were characterized at both oligodendrocyte developmental stages using the whole cell configuration of the patch-clamp technique. No differences between these two stages were detected, both types expressed a large K+ inward rectifying current similar to that described for oligodendrocytes from other vertebrate neuronal structures. This current could play an important role in the control of oligodendrocyte resting membrane potential. Our culture system provides a valuable model, close to the situation encountered in situ, not only to study the process of oligodendrocyte maturation, but also to identify the possible interactions between oligodendrocytes and cerebellar neurons such as granular and Purkinje cells during development.

Animals↗
PubMed1995

[Long-term results of the surgical treatment of spheno-orbital osteomeningioma].

The authors report a series of 21 cases of spheno-orbital "en plaque" meningiomas operated on between 1981 and 1993. All patients underwent surgery via fronto-temporal approach with orbito-zygomatic removal, followed by bone reconstruction. A complete tumor resection was performed in 15 cases. In the remaining patients, tumor resection remained subtotal, as the cavernous sinus was involved. Histological examination disclosed a low grade meningioma in 17 cases, high grade meningioma in the other patients. Radiation therapy was performed in 5 patients, when the tumoral resection was incomplete or for high grade meningiomas. The mean follow up was 7 years. One patient died in the post-operative course. Transient ophthalmoparesis occurred in 9 cases, 2 patients had pre-operative oculomotor palsy related to tumoral extension in the cavernous sinus and remained unchanged. Visual acuity remained unchanged after surgery in all patients who presented with normal visual acuity. It was unchanged or improved in 63% of patients who presented with moderate visual impairment. Despite the extent of the bone resection, the cosmetic results were good or excellent in 75% of patients, fair in 17%, and bad in 8%. Recurrence of the tumor occurred in 3 patients, with high-grade meningiomas (2 cases) or after subtotal removal of a low-grade meningioma (1 case). Orbito-fronto-temporal approach is necessary to complete the resection of the tumor extended in the orbit, the orbital fissures or the optic canal. Early operation allows a complete tumor resection before the tumor extends to the cavernous sinus.

Adult↗
PubMed1994

[Pneumopathy induced by pirindopril. A case report].

Cough is known to be the major respiratory side effect of treatment with angiotensin converting enzyme inhibitors (ACEI). Recently, ACEI have been implicated in drug-induced lung disease. We report a new case of diffuse pneumonitis which occurred during treatment with ACEI. A 73-year-old man was admitted for cough, dyspnea at rest, fever and weight loss. The patient had been treated with the ACEI pirindopril during 6 months for systemic hypertension. Chest radiographs showed reticular infiltrates in the upper lung fields. A CT scan confirmed the infiltrates and showed pleural thickening and airspace opacities. White blood cell counts showed 15,700/mm3 leucocytes with 940 eosinophils/mm3. Transbronchial biopsy was consistent with infiltration of the lung with eosinophils. There was no evidence for another etiology. Once the drug was withdrawn, clinical and radiological abnormalities improved but steroids were required to control symptoms. This report suggests that pirindopril, as captopril, can induce the picture of drug-induced pulmonary disease.

Aged↗
PubMed1993

[A neoclassical four-sector model for estimating the structural effects of liberalization of the labor market].

"This paper describes the basic set-up of a macroeconomic model disaggregated into 4 sectors. The purpose of the model is to analyze the structural effects of immigration policy. In a first section, the working of the model is illustrated by computing multipliers for various exogenous changes. In particular, the sensitivity of the multipliers with respect to the parameter values is discussed. The next section deals with the incorporation of the labour market and presents some simulation results based on theoretically plausible parameter values." The geographical focus is on Switzerland. (SUMMARY IN ENG AND FRE)

Developed Countries↗
PubMed1992

Dantrolene inhibits halothane-induced membrane reorganization. A study using 31P-NMR and differential scanning calorimetry.

The action of the relaxing agent dantrolene on dipalmitoylphosphatidylcholine (DPPC) model membranes in the presence and absence of the general anesthetic halothane has been investigated by DSC and 31P-NMR. Dantrolene has a weak effect on both the thermodynamic and NMR parameters of the pure model membrane. When halothane is present in the system, the relaxing agent acts to counterbalance the strong anesthetic-induced membrane perturbation. This is reflected in DSC experiments by a change of the enthalpy variation (delta H) and of the main gel-to-fluid phase transition temperature (Tc) towards the values of the pure lipid system. The amount of halothane-induced small tumbling vesicles, as detected by 31P-NMR by the superposition of an isotropic line on a lamellar-type powder spectrum, is considerably reduced upon dantrolene addition. This means that the relaxing agent "cures" the membrane de-structuring action promoted by halothane. Membranes first treated with dantrolene are also protected from the halothane perturbation. So, the relaxing agent is both "curative" and "preventative" against halothane. The optimum effect is obtained for 1 dantrolene molecule per ca 34 halothane molecules. The mechanisms of action were discussed in relation to membrane fluidity.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1992

31P NMR and freeze fracture studies of sarcoplasmic reticulum membranes from normal and malignant hyperthermic pigs: effect of halothane and dantrolene.

The effects of halothane and dantrolene on sarcoplasmic reticulum membranes isolated from normal and malignant hyperthermia pig muscle have been investigated using 31P NMR and freeze fracture electron microscopy. The dynamical and structural changes are estimated from the second moment, as calculated from 31P NMR spectra. For both membranes, addition of halothane induces a similar decrease in the spectral second moment. At high concentration of halothane, freeze fracture replicas show small unilamellar vesicles or mixed micelles, uniformly sprayed in the case of malignant hyperthermia membranes but mainly aggregated for the normal ones. The effect of halothane on both membranes is partially inhibited by adding dantrolene. These results suggest that (i) the malignant hyperthermia syndrome is not directly related to the polar heads of phospholipids and (ii) dantrolene counteracts unspecifically the disturbing effect of halothane at the lipid level.

Animals↗
PubMed1991

Halothane-induced membrane reorganization monitored by DSC, freeze fracture electron microscopy and 31P-NMR techniques.

The effect of the volatile anaesthetic halothane on the structure and dynamics of lipid multilayers (dimyristoyl- and dipalmitoylphosphatidylcholine, DM- and DP-PC, aqueous dispersions) was studied using Differential Scanning Calorimetry (DSC), Freeze Fracture Electron Microscopy and solid state phosphorus-31 Nuclear Magnetic Resonance (31P-NMR). The action of the drug depends upon the halothane-to-lipid molar ratio, Ri, and temperature. With DPPC lipids, three main regions can be distinguished: i) 0 less than Ri less than 0.7, ii) 0.7 less than Ri less than 2 and iii) Ri greater than 2. As Ri increases in the first region, a linear decrease in the main gel-to-fluid phase transition temperature (Tc), a broadening in the DSC transition peak and a lowering in the enthalpy variation (delta H), are observed. A minimum in delta H is reached at Ri = 0.7. In this region, 31P-NMR spectra indicate that the multibilayer structure is maintained. In the second region, Tc still decreases with the same slope, but delta H increases up to a plateau value for Ri = 2. In the lipid fluid phase, an isotropic NMR line appears superimposed on the powder pattern that corresponds to a lamellar phase. For Ri greater than 2, Tc and delta H remain almost constant. At values of temperature that are greater than Tc, a growing isotropic line occurs in 31P-NMR spectra. This means a new supramolecular structure made of lipids and halothane is stabilized. This structure has been characterized as small vesicles of about 400 A to 600 A diameter by Freeze Fracture electron microscopy observations. With DMPC and low ratios (Ri less than or equal to 2), DSC and NMR results are similar to those obtained for DPPC. However, the minimum delta H is reached at Ri = 0.2 and the decrease in Tc is faster than for DPPC when Ri increases from 0. For Ri greater than 2, while Tc and delta H remain constant as in the case of DPPC, 31P-NMR spectra of DMPC systems show a superimposition of an isotropic line and two powder patterns, which correspond to small tumbling vesicles, a possible hexagonal phase and a lamellar phase respectively. Halothane, thus acts on model membranes in two different steps: at low Ri the bilayer is disturbed but keeps its structure. Whereas for higher drug concentrations, a new organization of lipids seems to be stabilized for T greater than Tc.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1991

[Pulmonary hemosiderosis. Hemodynamic or idiopathic origin? Diagnostic contribution of imaging and review of the literature].

We report two cases of Pulmonary Hemosiderosis. The first patient (adult male) had an angiosarcoma of the left auricle and developed pulmonary arterial hypertension, was treated by surgery and chemotherapy. The other patient (adult female) suffered from Idiopathic Pulmonary Hemosiderosis (IPH) and had been treated by corticosteroids for fifteen years, with one acute episode during this period. We discuss the etiological diagnosis and the contribution of chest radiographs, CT-scan and MR Imaging in this rare illness according to literature. IPH occurs mostly in childhood with acute and fatal issue, whereas presents as a chronic form in adults. Assessment of IPH requires large investigations to eliminate hemodynamic, hemato-, immuno-, carcinological disorders, and infectious agents as well. Review.

Adult↗
PubMed1990

Ionic control of intracellular pH in rat cerebellar Purkinje cells maintained in culture.

1. Intracellular pH (pHi) was measured in single rat cerebellar Purkinje cells maintained in primary culture using microspectrofluorescence analysis of the intracellularly trapped pH-sensitive dye 2',7'-bis-(2-carboxyethyl)-5 (and -6)-carboxyfluorescein (BCECF). 2. The ratio of the fluorescence signals measured at 530 nm in response to an alternating excitation at 450 and 490 nm was calibrated using the K(+)-H+ ionophore nigericin. This calibration gave a steady-state pHi of 7.06 +/- 0.02 (S.E.M., n = 17) when cells were perfused by a 5% CO2-25 mM-HCO3(-)-buffered solution at an external pH of 7.40 at 37 degrees C. 3. Replacement of external chloride with gluconate in the presence of bicarbonate induced a cytoplasmic alkalinization of about 0.3 pH unit. This alkalinization was independent of external sodium and was greatly reduced by 0.5 mM-DIDS, indicating the presence of a chloride-bicarbonate exchange. 4. In bicarbonate-free (HEPES-buffered) solution the steady-state pHi was 7.37 +/- 0.02 (n = 19), significantly higher than in bicarbonate-buffered solution. Recovery from an intracellular acid load brought about by the ammonium chloride pre-pulse technique was blocked by the removal of external sodium or the addition of 1.5 mM-amiloride, indicating the presence of a sodium-hydrogen exchange. 5. In bicarbonate-buffered solution pHi recovery after an acid load was also completely blocked by addition of 1.5 mM-amiloride indicating the absence of a bicarbonate-dependent acid extrusion mechanism. 6. Addition of 12-O-tetradecanoylphorbol-13-acetate (TPA, 100 nM) induced an amiloride-sensitive alkalinization of about 0.3 pH unit in bicarbonate-buffered solution but had no effect in HEPES-buffered solution. This observation suggests that in cultured Purkinje cells the sodium-hydrogen exchanger could be activated through a protein kinase C pathway only when pHi is maintained at a low physiological value by the activity of the chloride-bicarbonate exchange.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1990

[Congenital anomaly of the inferior vena cava with hemiazygos continuation. Ultrasonic diagnosis].

Congenital anomaly of the inferior vena cava with hemiazygos continuation: ultrasonic diagnosis. We report a case of agenesis of the retro-hepatic segment of the inferior vena cava in an asymptomatic 18 year old woman, found on a routine chest-ray. This rare illness was suspected on the findings of conventional radiology and was assessed by ultrasonography that shows direct termination of hepatic veins in the right auricle, and the hemi-azygos vein behind the aorta. Our radiological and ultrasonographic findings are confirmed by the literature. In the absence of any clinical signs, CT-scan and MR Imaging were note used in investigations. Nevertheless their usefulness has been extensively reported by many authors. Cavography remains useful before surgery.

Adolescent↗
PubMed1990

[Radiologic aspect of benign pleural fibrous mesothelioma. Reports of 4 cases].

Solitary fibrous tumor or pleural fibroma is a rare tumor. It grows slowly and has a good prognosis after surgical resection. Pleural features, staging and even the fibrous nature are analysed by radiological findings. Ultrasonic diagnosis, CT-Scan and MR Imaging are very useful but non specific: the differential diagnosis between benign and malignant tissue is still based on histological study of the whole surgical specimen. Review of the literature.

Adult↗