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Biomedical subjects

L Picard

Publications and source records attributed to L Picard.

At least 91 records · Page 5Linked to original sources
PubMed1994

Lung and systemic oxidant and antioxidant activity after graded smoke exposure in the rat.

We wanted to determine the effect of a graded smoke inhalation on lung and systemic oxidant stress, and its relationship to physiological and histological change. Male Wistar rats were given 12 breaths of 10 ml/kg (n = 8) (group 1) or 20 ml/kg (n = 8) (group 2) tidal volume, using cotton toweling smoke through the trachea using positive pressure. Rats were monitored, then killed at 24 hr. Data were compared to controls (n = 8). Peak group 1 and group 2 carboxyhemoglobins were 22 +/- 6 and 46 +/- 6%, with a mortality prior to 24 hr of 14% and 50%, respectively. Group 1 rats showed only moderate lung dysfunction but with severe airway inflammation and edema, alveolar inflammation and atelectasis, with a decrease in PaO2 from the control of 96 +/- 4 to 72 +/- 5 torr. No increase in lung, liver, or kidney oxidant-induced lipid peroxidation, measured as malondialdehyde lung, liver, or kidney oxidant-induced lipid peroxidation, measured as malondialdehyde (MDA), or decrease in the antioxidant defenses catalase was noted. Group 2 rats demonstrated severe airways edema, alveolar atelectasis, and alveolar edema, and a PaO2 decreasing below 60 torr, corresponding with a 3-fold increase in lung tissue MDA and 35% decrease in catalase. In addition, liver and kidney tissue MDA doubled, and catalase activity decreased by 40%. Increased oxygen consumption was also demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1994

Dissection of intracranial vertebral arteries revealed by subarachnoidal haemorrhage. Report of seven cases.

Between April 1986 and April 1991, seven cases of meningeal haemorrhage consecutive to dissection of the 4th segment of a vertebral artery were observed at the Neuroradiology Department of the Nancy University Hospital. Four of the 7 patients were men, and 3 were women; mean age varied from 45 to 61 years. The clinical presentation was not suggestive, except in one case where the haemorrhagic episode was associated with Wallenberg's syndrome, pointing to the aetiological diagnosis. The outcome was variable. Two patients died of early complications of the haemorrhage which occurred before treatment could be given. In 2 others patients treated with antiplatelet agents the outcome was favourable; however, at angiography the lesions regressed in one of these two patients, but they progressed in the other with formation of a false aneurysm. The remaining 3 patients were treated by endovascular occlusion of the lesion-bearing vessel: one died of complications of a haemorrhage-induced vasospasm; the other two are symptomless after a 2 to 6 months follow-up.

Aortic Dissection↗
PubMed1994

[Pericranial sinus].

This study concerns four cases of sinus pericranii observed at the Neurological Department of Nancy. Sinus pericranii is a direct communication between the outer surface of the skull and the intracranial venous sinuses. It may be congenital, acquired or traumatic. This abnormality, usually located in the midline and often in the frontal region, is usually symptomless, but some patients complain of headache, nausea and vertigo. Sinus pericranii shows as a fluctuating non pulsatile mass of reddish or bluish colour, expanding when the patient bends his head down. Radiography usually shows one or several bone defects opposite the lesion found at CT bone window. On soft tissue window the mass is not calcified and usually enhanced by contrast injection. It is sometimes possible to visualize the vascular communication between the extracranial region and the underlying dural sinus. When visualization is blurred, or CT shows intracerebral abnormalities, MRI examination is required. Angiography with subtraction in venous phase (40 to 60 seconds after the injection), sometimes aided by films taken in head down position. It is of interest only in cases where CT and MRI have shown associated vascular abnormalities. Otherwise, direct injection of contrast medium into the malformation makes it possible to assert the diagnosis of sinus pericranii and to determine the flow rate within the malformation, which to some extent commands the the therapeutic technique. In patients with small and asymptomatic sinus pericranii absention is the rule. When the sinus is of moderate size, and the flow rate not rapid and when there is no significant communication with the cerebral veins, endovascular sclerosis may be advocated. In all other cases, surgical removal is recommended and is usually easy.

Angiography, Digital Subtraction↗
PubMed1993

Relationship of burn-induced lung lipid peroxidation on the degree of injury after smoke inhalation and a body burn.

OBJECTIVE: We compared the effect of a modest smoke inhalation injury, a burn injury alone, and a smoke inhalation injury plus a body burn, on the degree of lung oxidant-induced lipid peroxidation and lung injury. DESIGN: Prospective animal study with concurrent controls. SETTING: An animal laboratory. SUBJECTS: Forty-four adult yearling female sheep (weight range 45 to 50 kg). INTERVENTIONS: Forty-four sheep were prepared with lung and prefemoral (soft tissue) lymph fistulas. Twelve breaths of cooled smoke with tidal volume of 10 mL/kg body weight were given to 24 sheep, producing a peak blood carboxyhemoglobin of 25% to 30%. Twelve sheep also received a 15% total body surface third-degree burn. Sheep were killed at 4 or 24 hrs. MEASUREMENTS AND MAIN RESULTS: Circulating lipid peroxidation was monitored as conjugated dienes and tracheobronchial mucosal and lung parenchyma as malondialdehyde. Antioxidant defenses were monitored by catalase activity. Lung physiologic and histologic changes were compared. We noted intense airways inflammation in both smoke inhalation groups and lung parenchymal inflammation in all groups. Lung lymph flow was modestly increased (two-fold) in the smoke inhalation groups. Alveolar water content was not significantly increased after any injury. PaO2 was decreased at 24 hrs after the smoke insult alone. Parenchymal malondialdehyde content did not increase with the smoke insult alone, but did increase from a control value of 110 +/- 20 to 270 +/- 24 nmol/g tissue by 4 hrs in the combined burn and smoke injury group, while catalase activity decreased. Airway mucosal malondialdehyde did not increase in any group. CONCLUSIONS: We conclude that alveolar capillary permeability is not increased early after a moderate smoke injury or smoke injury with burn. Lipid peroxidation is not increased in large airway or lung parenchyma with early after-smoke exposure. The addition of a burn significantly increases lung parenchymal lipid peroxidation, but the oxidant changes do not correspond with the degree of early lung dysfunction.

Animals↗
PubMed1992

Sex-dependent loss of bisected bovine morulae after culture and freezing.

The objective of this study was to determine the post-transfer survival rate of bovine embryos cultured between the time of bisection and freezing. In this experiment 158 morulae were bisected and both portions were cultured for 24-44 h either in vivo after transfer to sheep oviducts (n = 80 morulae) or in vitro (n = 78 morulae) in Ham's F10 medium with 20% fetal calf serum, with bovine oviduct cells or in medium collected from oviduct cultures (conditioned medium). After culture, half of each morula was fixed for cytogenetic sex determination (n = 125) and the other half was frozen. The frozen halves were later thawed and transferred (n = 115) to recipients, who were, if pregnant, slaughtered to determine the sex of the fetus. The culture resulted in better pregnancy rates than those previously reported for embryos frozen immediately after bisection. The sex of 49 (33 males, 16 females) of the fixed demi-morulae was determined, and 38 of the transferred demi-morulae established pregnancies (23 males, 10 females and 5 fetuses that were not recovered). The male:female ratio in in vivo and in vitro culture groups was significantly different from the expected ratio of 1:1 and suggests that manipulation and culture of embryos results in a preferential loss of female embryos.

Animals↗
PubMed1992

[MRI exploration of the hypothalamo-hypophyseal axis].

MR Imaging has become the procedure of choice for the exploration of the pituitary region. MR contrast resolution is far better than the finest CT examination, especially concerning the microadenomas and the neurohypophysis. The present paper concerns, at first the major principles of magnetic resonance imaging, its application for the study of the pituitary region including the use of contrast agent (Gadolinium). Lastly, MR anatomy and physiological variations are presented.

Adolescent↗
PubMed1992

[Transluminal angioplasty in the treatment of vasospasm. Value of transcranial Doppler in the diagnosis and follow-up].

Vasospasm (V.S.) transluminal angiographic treatment (T.L.A.) is recommended in case of symptomatic V.S. before or after surgery. V.S. diagnosis and follow up after T.L.A. rely on clinical and transcranial doppler (T.C.D.) data. Before T.L.A. angiography (A degrees) demonstrates V.S. degree and location. T.L.A. technic is described. The authors report 14 cases of T.L.A. (7 before and 7 after surgery). Before surgery in 4 cases patients exhibited ischemic symptoms from V.S.: 2 died (one from reanimation problems the other from a new hemorrhage). After surgery of 7 patients one died from artery rupture, one from extra-neurologic complication. T.C.D. capacity to follow up V.S. is emphasized. As soon as T.L.A. is performed the mean cerebral blood flow (C.B.F.) decreases (< 100 cm/s) and does not increase anymore. At the level of non dilated arterial segments V.S. may increase after T.L.A.: it is then recommended to dilate all the spastic arteries, as far as it is possible. After T.L.A. C.B.F. may decrease in arteries far from the dilated ones probably because arterial supplies are no more necessary.

Angioplasty, Balloon↗
PubMed1991

The sex ratios of bovine embryos produced in vivo and in vitro.

The male:female ratio of developing bovine embryos produced and allowed to develop in vitro and in vivo was determined retrospectively from the cytogenetic analysis of 804 embyos. The overall male:female ratio of the 307 (38%) embryos that could be sexed was 162 (52.8%):145 (47.2%) and did not differ (P>0.05) from the expected 1:1 ratio. Among premorula stage embryos produced in vivo (n = 66) and in vitro (n = 30), the ratios were 1.2:1 and 0.76:1, respectively. Among morulae and blastocysts produced in vivo (n = 74), produced and cultured in vitro (n = 106, and produced in vitro and cultured in vivo (n = 31), the ratios were 1.11:1, 1.3:1 and 0.94:1, respectively, none of which differed significantly from 1:1. There was no difference (P>0.05) in the number of cells or mitotic index between male and female morulae and blastocyst, respectively.

Journal Article↗
PubMed1991

Radio-contrast enhancement of urinary tract stones.

Most urologists treating stone disease with any method (ESWL, PCL, URS) have encountered problems of poor stone visualization with fluoroscopy. This difficulty to localize urinary tract (UT) stones or fragments may result in incomplete stone extraction, prolonged surgery and increased risk of recurrence and post-operative complications. We have sought and found means to increase the radioopacity of mineral UT stones by a simple pre-operative perfusion technique. The capacity of radioopacification has first been demonstrated in in vitro incubations of fragments of human mineral stones with aqueous solutions of barium, of the lanthanides and of the two natural actinides. Most of the incubations led to considerable radio-contrast enhancement and heavy metal incorporation, measured by X-ray fluorescence analysis. Dogs with implanted human stone fragments were used as an in vivo model. The UT were perfused through a retrograde pyelic catheter with heavy metal salts solutions, the ensuing radioopacification of the implanted UT-stones was estimated by abdominal radiographies and the metal incorporation was measured on the retrieved stones. Considerable radioopacity enhancement together with heavy metal incorporation was observed for the following elements: Sr, Ba and the lanthanides Gd and Yb. The pathological evaluation of the urothelial linings from animals treated with lanthanide salt showed no toxic effects.

Animals↗
PubMed1991

Cervical cord compression in scleroderma. One case.

The cervical spine is rarely involved in scleroderma. The lesions reported here consisted of osteolysis of the posterior arches disturbing vertebral statics, and exuberant calcifications responsible for spinal cord compression by stenosis of the vertebral canal.

Calcinosis↗
PubMed1990

Production of chimaeric bovine embryos and calves by aggregation of inner cell masses with morulae.

Bovine inner cell masses (ICMs) were isolated by immunosurgery at day 8 or 10, or by dissection at day 14, and combined with day-5.5 morulae. Aggregation was obtained between 89%, 62%, and 0% of the day-5:day-8, day-5:day-10, day-5:day-14 composites, respectively. Chromosome analysis of composites, respectively. Chromosome analysis of composites potentially carrying the 1/29 translocation as a chromosome marker and temporarily transferred to the bovine uterus for 8 days showed that chimaeric day-14 embryos can be obtained from day-5:day-8 aggregation. The definitive transfer of eight day-5:day-8 and 11 day-5:day-10 composites resulted in the birth of six and four calves, respectively; five of the six, but none of the four, were chimaeric. The five chimaeras showed mostly the ICM phenotype. The morphological differences between ICMs at different stages of development were examined by electron microscopy and related to the success of the aggregation technique. It is concluded that bovine embryonic cells can regulate for at least 3 days difference in development but not 5 days even though aggregation is still possible.

Animals↗
PubMed1990

Role of angioplasty in the treatment of symptomatic vascular spasm occurring in the post-operative course of intracranial ruptured aneurysms.

Angioplasty of vascular spasm (VS), related to subarachnoid hemorrhage (SAH) has been recently introduced to the medical field. The authors report 5 cases treated by this mean in the postoperative period. These patients were all symptomatic from their VS inspite of early surgery and of the preventive treatment by Nimodipine. In all cases, obtained increase in the caliber of the spastic vessels was followed by a rapid clinical improvement coupled with a significant decline of the flow rates as confirmed by transcranial Doppler (TCD). No recurrence of VS has been observed. This technique appears quite effective provided that it is performed as early as the clinical symptoms come out in correlation with important acceleration of flow rates on TCD.

Adult↗
PubMed1990

Long term hemodialysis spondylarthropathy: an atlanto-occipital location.

A 41 years old patient on hemodialysis for 17 years with a clinical and radiological picture of osteoarticular beta 2 microglobulin amyloidosis, is presented. The patient had skeletal involvements, included cystic lesions of the left hip and both humeral heads and a C5/C6 spondylarthropathy. She had also associated carpal tunnel syndrome. Radiological exploration of the atlanto-occipital articulation demonstrated destructive changes. Histology documented osseous and periarticular deposition of beta 2 microglobulin derived amyloid. This is an unusual location of destructive spondylarthropathy in a patient on chronic hemodialysis.

Adult↗
PubMed1990

Dural fistulae of the tentorium cerebelli. Radioanatomical, clinical and therapeutic considerations.

Among the 84 intracranial dural fistulae treated in the Neuroradiology department of the University Hospital Centre of Nancy between August 1983 and April 1990, 10 (11.9%) were located on the tentorium cerebelli. The patients were 7 men and 3 women aged from 41 to 61 years at the time of diagnosis. All tentorial dural fistulae showed an exclusively cortical drainage, and only one of them was associated with probable thrombosis of a major sinus. Nine patients presented with at least one episode of neurological deficit (including 2 with progressive ascending myelopathy) associated with a cerebro-meningeal haemorrhage in 6 cases. In all patients the initial treatment was an endovascular one, subsequently reinforced by surgery in 2 patients. In every case the clinical condition was improved or stabilized and no recurrent haemorrhage was observed, but radioanatomical cure was obtained in only 3 patients: 1 treated by the endovascular route and 2 by embolization combined with surgery. The anatomical, physiopathological and clinical aspects of these particular fistulae and the different possible therapeutic approaches are discussed.

Adult↗
PubMed1990

Pelizaeus-Merzbacher disease. Contribution of magnetic resonance imaging to an early diagnosis.

The lesions of the cerebral white matter which characterize Pelizaeus-Merzbacher disease are classically observed at pathological examination. An early diagnosis can now be obtained by magnetic resonance imaging (MRI). In an eutrophic first son born at term, stridor, nystagmus-like eye movements and axial hypotonia were noted immediately after birth and pyramidal signs appeared at 2 months, the only extra-clinical finding at that age being prolonged latencies of evoked visual potentials. An MRI exploration, performed at 3 months, showed that compared with the grey matter the white matter emitted a low-intensity signal on the T1-weighted sequence and a high-intensity signal on the T2-weighted sequence (signal inversion), such diffuse and symmetrical MRI abnormalities being typical of dysmyelination. When combined with suggestive clinical signs, these abnormalities confirm the diagnosis of Pelizaeus-Merzbacher disease, even in the absence of a familial history, and make it possible to warn the parents of the poor prognosis and the risk of recurrence among future sons.

Brain↗
PubMed1990

Effects of a choline-deficient ethionine-supplemented diet on phospholipase C activity in mouse pancreatic acinar cell membranes and in electropermeabilized mouse pancreatic acini.

The nonhydrolyzable guanyl nucleotide GTP gamma S stimulated phosphoinositidase C activity in two preparations obtained from mouse pancreatic acini labeled with myo[2-3H]inositol: a cell-free membrane fraction and intact electropermeabilized acini. This action was dose-dependent, was shared by other nonhydrolyzable guanyl nucleotides such as GMP-phencyclidine hydrochloride and GMP-PMP, as well as by fluoride, and was calcium-independent. Contrarily, no effect was observed even at doses of GTP gamma S as high as 10 microM when the same protocol was repeated on identical acinar preparations from mice fed a choline-deficient, ethionine-supplemented diet. This regimen is known to uncouple secretagogue-receptor occupancy from inositol 1,4,5-trisphosphate generation in pancreatic acinar cells and lead to necrotizing hemorrhagic pancreatitis. These data lead us to conclude that the ethionine-induced inactivation of guanyl nucleotide-dependent pancreatic phosphoinositidase C in pancreatic acinar cells is not the result of either a decrease in GTP level or a decrease in GTP availability. These findings further confirm previous work from this laboratory, which has shown that the biochemical lesion induced by this diet occurs after the agonist-receptor binding step. The diet-induced lesion could be either at the level of the G-protein that couples the enzyme with the receptor or at the level of the phospholipase itself.

Animals↗