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Biomedical subjects

J C Gautier

Publications and source records attributed to J C Gautier.

At least 19 recordsLinked to original sources
PubMed1992

[VVI mode cardiac pacing: cause or risk factor of cerebral embolism?].

Epidemiological studies suggest that VVI pacing is associated with a higher risk of embolic complications than atrial or dual chamber pacing. However, no studies have been performed on pacemaker patients admitted to a neurological department with a cerebral embolism. The authors report the cases of 8 patients (6 men and 2 women) with an average age of 74 years and having the following characteristics: 1) a cerebral embolism, 2) a permanent cardiac pacemaker (7 VVI and 1 DDD mode). The average delay between implantation of the pacemaker and the neurological complication was 31 months. Cardiological investigations at the time of admission showed: a clinically evident cause of cardiac embolism in 3 cases (2 with VVI and 1 with DDD pacing); paroxysmal or permanent atrial fibrillation in 4 cases with VVI pacing at the time of the embolic event (in only one case at the time of implantation); various echocardiographic abnormalities in 6 of the 7 patients who underwent this examination, mainly left atrial dilatation (6/7), septal wall motion abnormalities in all related to ventricular pacing and unexplained left ventricular dilatation in 2 patients with VVI pacemakers. These results suggest that although the etiology of cerebral embolism was probably multifactorial in some patients, VVI packing probably a predisposing role, though not the only cause, and could be considered to be an embolic risk factor as suggested by previous epidemiological studies. These preliminary retrospective data should be interpreted cautiously taking into account the small population size. Prospective studies on pacemaker patients with cerebral embolism are required.

Aged↗
PubMed1992

[Cerebral infarction, placoid epitheliopathy and sarcoidosis].

We report a case of cerebral infarction in the basal territory of the left middle cerebral artery, associated with acute posterior multifocal placoid pigment epitheliopathy, most probably due to sarcoidosis. Neurological symptoms resolved spontaneously without sequelae. We discuss the relationship between acute posterior multifocal placoid pigment epitheliopathy, sarcoidosis and cerebral granulomatous angiitis.

Adult↗
PubMed1992

Anti-liver microsomes autoantibodies and dihydralazine-induced hepatitis: specificity of autoantibodies and inductive capacity of the drug.

Anti-liver microsomes (anti-LM) autoantibodies in patients with dihydralazine-induced hepatitis were found to react specifically with cytochrome P4501A2 (P4501A2) but not with P4501A1 expressed in yeast and bacteria. These results were confirmed by immunoinhibition of methoxyresorufin-O-demethylase activity (supported by the P4501A subfamily); anti-LM antibodies more strongly inhibited this activity in yeast expressing P4501A2 than in yeast expressing P4501A1. Anti-LM were shown to be specific to the disease; in three cases, these autoantibodies were present at high titers during disease, whereas the titers decreased upon recovery and became undetectable a few months after recovery. Thus, there exists a time-dependent relationship between the disease and the autoantibodies, which does not prove that the autoantibodies are causative of the hepatitis; they might only be a marker. The inductive capacity of dihydralazine toward P450 was also studied. In rats treated in vivo and in human hepatocytes treated in vitro with dihydralazine, a 2-fold increase in P4501A2- and P4501A-supported monooxygenase activities was found. The levels of the other P450 isoforms tested were unchanged during treatment, both in vivo in rats and in vitro in cultures of human hepatocytes. In human hepatocytes, dihydralazine produced a dose-dependent increase in the level of P4501A up to 0.1 mM; induction of P4501A was less strong at 0.2 mM and disappeared at 0.5 mM. The same treatment did not change the level of P4503A4, taken as control. The strong heterogeneity in the expression of P4501A enzymes in human liver and the capacity of these enzymes for induction by dihydralazine and by other compounds might be predisposing factors in this autoimmune disease.

Animals↗
PubMed1992

Characterization of human lung microsomal cytochrome P-450 1A1 and its role in the oxidation of chemical carcinogens.

Rat and human lung microsomal cytochrome P-450 (P-450) enzymes have been characterized with regard to their catalytic activities towards several xenobiotic chemicals, including procarcinogens, in different microsomal preparations. Rat lung microsomal P-450s were more active than the human P-450s in catalyzing most of the monooxygenation reactions. Human lung microsomal P-450 was solubilized and purified. Human lung microsomes contain approximately 10 pmol of P-450/mg of protein, on the basis of Fe2+.CO versus Fe2+ difference spectra of the eluates obtained from an octylamino-agarose column. The partially purified P-450 preparations from two human lung microsomal samples showed high activities for the conversion of both (+)- and (-)-isomers of 7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene to genotoxic products. After DEAE-cellulose column chromatography, a partially purified P-450 fraction containing polypeptides of Mr 52,000 and 58,000 was obtained from the early fraction of the octylamino-agarose column eluate, and an electrophoretically homogeneous protein having a molecular weight of approximately 52,000 was recovered from a latter fraction. The amino-terminal amino acid sequences of the two peptides in the earlier fraction were determined; neither polypeptide appears to resemble any known P-450 protein. The protein from the latter octylamino-agarose fraction was immunoreactive with anti-rat P-450 1A2 and anti-human P-450 1A2 but not with antibodies raised against other P-450 enzymes or autoimmune antibodies that specifically recognize human P-450 1A2. A tryptic peptide was isolated from the preparation, and the amino acid sequence matched that of human P-450 1A1 perfectly (residues 31-48) but not that of human P-450 1A2. All of nine human lung microsomal samples examined contained proteins that were immunoreactive with rabbit anti-rat P-450 1A2 and catalyzed the activation of 7,8-dihydroxy-7,8-dihydrobenzo(a)pyrene. The activities could be inhibited by rabbit anti-rat P-450 1A2 and, to a lesser extent, by anti-rat P-450 1A1. The addition of 7,8-benzoflavone caused inhibition or stimulation, depending upon the particular human lung microsomal preparation. Thus, this work clearly shows that human lung microsomes contain at least two major P-450 enzymes; human P-450 1A1 is present in lungs and can actually catalyze the activation of environmental procarcinogens, including polycyclic aromatic hydrocarbons.

Animals↗
PubMed1992

[Infarcts in the region of the middle cerebral artery. Study of 501 cases in 484 patients].

We report a study of 501 infarcts in the middle cerebral artery (MCA) territory, in 484 patients. All cases had an appropriate low-density area on computed tomography. The basal (perforators) territory was involved in half the cases and the motor pathways either in the pre-rolandic area or in the internal capsule in 90%. In all locations, except for watershed infarcts, the main cause was cardiac embolism. Atrial fibrillation accounted for 59%, the two other main causes were myocardial infarction and paradoxical embolism. Atherosclerosis accounted for less than one third of the cases. Among 102 internal carotid artery occlusions less than one half were due to atherosclerosis, cardiac embolism and dissecting aneurysms accounted for 22% each. None of 34 MCA occlusions were due to atherosclerotic thrombotic occlusion. Transient ischemic attacks were recorded in 22% of the cases. Stroke-in-progression with a mean duration of 6-8 hours in hospital, was noted in nearly half the cases. In a small group of MCA infarcts paralysis began and predominated on the lower limb, fifteen contralateral old MCA infarcts were silent. Ten of these were on the right side. The 15 patients with silent infarcts were all right-handed.

Adolescent↗
PubMed1991

[Comparison between x-ray computed tomography and magnetic resonance imaging after transient ischemic accidents].

We studied 18 patients with transient ischemic accidents (TIA) and normal CT scan during the first 24 hours. MRI was performed 9 days later on average. MRI revealed abnormalities in 10 patients (56 p. 100), but only 5 of them (27 p. 100) had lesions corresponding to TIAs, and in every case these were in the carotid territory. In the 7 patients with clinical signs of TIA in the vertebro-basilar territory, MRI was always negative. In 5 patients (27 p. 100), MRI showed abnormalities that were unrelated to TIA. This study suggests that MRI is of limited value in detecting brain tissue abnormalities and is perhaps not more sensitive than CT in vertebro-basilar TIA. However, in view of the small number of patients these results must be interpreted with caution.

Humans↗
PubMed1991

[Thrombolytic agents in cerebral infarctions].

Thrombolytic agents are aimed at restoring arterial patency thus reducing the risk of cerebral infarction in case of arterial occlusion by blood thrombus or embolus. A review of data from the literature is presented, and the authors have tried to answer the following questions: 1) What are the probabilities of early mortality (first 30 days) and of morbidity due to untreated or medically (thrombolysis excluded) treated cerebral infarction? 2) What are the morbidity and mortality rates after systemic thrombolysis or selective intraarterial thrombolysis? 3) Are the results of thrombolysis affected by the site of arterial occlusion (carotid or vertebrobasilar system)? 4) Does thrombolysis increase the risk of cerebral haemorrhage? 5) Can thrombolysis be regarded as an effective treatment and, if so, in which cases? This study of systemic thrombolysis yielded a mean mortality rate of 22.2%, with satisfactory functional outcome in 58.2% of the survivors. The corresponding figures for selective intraarterial thrombolysis were 29.7% and 84.5% respectively. However when the arterial territories occluded were taken into account, they became 10.4% and 84.4% respectively in the carotid system and 61.5% and 85.00% in the vertebrobasilar system. Comparisons between the natural history of cerebral infarctions, as far as it is known, and the results of thrombolysis suggest that thrombolytic agents are: 1) probably justified by the selective intraarterial route when the occlusion lies in the carotid system; 2) not indicated by the systemic route with urokinase or streptokinase but trials with tPA are being performed. These conclusions, however, must be interpreted with caution as they rest on general data leaving out a number of factors that are often neglected in reports particularly the exact site of arterial occlusion, chiefly in the vertebrobasilar system. From 3 limited cohorts it was possible to evaluate at about 14% the mortality rate in thrombolysis for basilar artery occlusion. This figure, compared with the 70-80% estimate found in the literature for untreated occlusions, suggests that the selective intraarterial thrombolysis may perhaps be indicated also in basilar artery occlusions. It must be noted that selective intraarterial thrombolysis is still an exceptional treatment which requires sophisticated techniques, highly qualified neuroradiologists and prompt application i.e. emergency stroke units.

Cerebral Infarction↗
PubMed1990

Arterial pathology in cerebellar infarction.

We reviewed 88 pathologically proven cerebellar infarcts, examining the entire thoracocervical arterial system (including the spinal part of the vertebral artery, the intracranial arteries, and the heart) in all cases. For 50 infarcts, we found an arterial occlusion. The intracranial part of the vertebral artery was involved in 38 infarcts (76%), the basilar artery in 20 infarcts (40%), and a cerebellar artery in 12 infarcts (24%). Eight infarcts were due to bilateral distal vertebral artery occlusions. For the 50 infarcts, the cause of the occlusion was atherosclerosis in 28 (56%) and a cardiac embolism in 12 (24%). For the remaining 38 infarcts, we found no arterial occlusions on postmortem examination. Of these 38 infarcts, 26 (68%) were associated with a cardiac source of emboli. For the entire group of 88 infarcts, atherosclerosis was the cause in 31 (35%), while a cardiac embolism was proven or presumed in 38 (43%). Dissecting aneurysms, atherosclerotic artery-to-artery embolism, or hemodynamic mechanisms could have been responsible for a few infarcts. We conclude that cerebellar infarcts often arise from cardiogenic embolism.

Aged↗
PubMed1990

[Paradoxal cerebral embolism: role of patent oval foramen].

A patent foramen ovale (PFO) is present in 25-35% of people at all ages of life and its size tends to increase with age. It is now possible to detect PFO's by contrast echocardiography and it has been shown that there exists quite frequently a spontaneous transient right-to-left shunt during systole and, moreover, a right-to-left shunt during Valsalva maneuver and coughing. Acute or chronic pulmonary hypertension are also causes of shunt. Besides, a highly statistical correlation has been found between PFO's and strokes of uncertain or absent cause. From 1984 to 1990 the authors have collected 29 cases with 47 embolic cerebral events. Twenty-five cases with 30 embolic cerebral events and a neurological report have been found in the literature from 1930 to 1986. The analysis of these 77 cerebral embolic events is presented. All ages and both sexes are equally affected. Several symptoms and signs can suggest the diagnosis: onset of the neurological disorders during an activity implying a Valsalva maneuver; onset during a recognized phlebitis of the legs of pelvis or, more often, in a clinical setting suggesting the possibility of phlebitis without overt symptoms and signs: post-partum, post-operative conditions with prolonged bed rest; concomitant pulmonary and cerebral embolism. In the authors series of 227 cerebral emboli, such paradoxical emboli account for 12.8% of the cases ant it is likely that the condition is still underdiagnosed.

Adult↗
PubMed1989

[Cerebellar infarction in the area of the posterior cerebellar artery. Clinicopathology of 28 cases].

We report a neuropathological study of cerebellar infarctions involving the territory of the posterior inferior cerebellar artery (PICA) in 28 cases. Fifteen cases involved the PICA territory only. In 13 cases infarctions in the anterior inferior cerebellar artery (AICA) territory and/or in the superior cerebellar artery (SCA) territory were also present. A thorough post-mortem study of the arterial supply of the brain from the heart up to the cerebellar arteries, including the cervical spine segment of the vertebral arteries was performed in 27 cases. The territory of the cerebellar infarcts has been ascertained. In 15/28 cases (54 percent), infarction involved the PICA territory only (17 infarcts). All of these cases had a benign outcome and death was due to another cause. Six of these were recent infarctions. None had evidence of swelling and tonsillar herniation. Infarcts were generally of small size and involved the entire PICA territory in only 2 cases. Most of these cases were unexpected discovered at autopsy. Cerebellar infarction in the territory of the medial branch of the PICA (9/17 infarcts) drew grossly a set square with a dorsal base and a ventral top headed for the IVth ventricle. Five out of these cases were associated with infarction in the dorsal and lateral medullary territories. Retrospective clinical study showed that they had been unnoticed or overshadowed by other neurological disorders (4 cases), or presented as Wallenberg's syndromes (4 cases), or as a pure vestibular syndrome (due to an infarction involving only the cerebellum) mimicking an acute labyrinthine disorder (1 case). Infarctions in the territory of the lateral branch of the PICA (5/17 infarcts) always occurred without medullary involvement. All of them were unexpectedly discovered at autopsy, and were unnoticed during the life (3 infarcts) or were overshadowed by other neurological disorders (2 infarcts). That was also the case in 2 cases of infarction in the whole PICA territory (3/17 infarcts). Thus infarctions strictly localized to the entire PICA territory only were rare. Thirteen/28 cases (46 p. 100) of infarction in the whole PICA territory were associated with infarction in the AICA and/or the SCA territories. This resulted from an association with other infarctions and not from an abnormally large territory of the PICA. Cerebellar swelling with brain stem compression and tonsillar herniation occurred 8/13 cases (62 p. 100). There were other massive median and paramedian brain stem infarctions involving midbrain, pons or medulla in 55 p. 100 of 13 cases.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1989

[Homografts in the human brain. Current data].

Since 1982, grafting of human nervous tissue on human central nervous system has been realized, mainly in Parkinson's disease. The present article reviews the theoretical basis of such procedures, i.e., the remarkable experimental work that began around the turn of the century. New approaches, e.g., using hydroxydopamine or MTPP, have greatly enlarged the field of experimental research. In man, grafts of adrenal medulla and, in a few cases, of fetal substantia nigra, have been realized in several hundreds of patients. The known results invite great caution. Brain grafting has also been considered in Huntington's chorea, trauma of the spinal cord and even schizophrenia. In animals, transplants of hypothalamus and pre-optic area have counteracted genetic endocrine disorders. Experimental researches are of high interest but their application to man raises major problems of efficiency and fundamental ethical and legal questions.

Animals↗
PubMed1989

[Cerebral vascular accidents in young subjects. A study of 133 patients 9 to 45 years of age].

We report 133 cases of strokes in patients aged 9-45 (male: 68, female: 65), mean age: 33.5 years. There were 112 arterial infarcts (84%), 9 venous infarcts (7%), 12 hemorrhages (9%). Among the arterial infarcts, 23 (20.5%) were due to a dissecting aneurysm, 17 (15%) to atherosclerosis, 13 (12%) to cardiac embolism. Echocardiography with contrast was performed in 69 patients showing a patent foramen ovale in 15. Mitral valve prolapse was present in 8, among which 5 had in addition a patent foramen ovale. Among 16 migrainous patients there were 7 dissecting aneurysms and 3 patent foramen ovale. Twenty two of 65 women were taking oral contraceptives at the time of the stroke. Strokes in patients taking oral contraceptives or during the puerperium accounted for 43% of the strokes in women. Ten cases (9%) have had no explanation. Venous infarctions were mainly due to puerperium and oral contraceptives. Hemorrhages were mainly due to arterial hypertension. No cause was found in 4/12 cases. The most useful investigations were angiography and echocardiography with contrast. This study confirms that extensive and early investigations are necessary in strokes in the young and particularly in women taking oral contraceptives, migraine patients and patients with mitral valve prolapse.

Adolescent↗
PubMed1988

Acquired ocular motor apraxia due to bilateral frontoparietal infarcts.

A case of acquired ocular motor apraxia in a 78-year-old man is reported. Disordered saccades and pursuit movements in the horizontal and vertical planes were recorded electro-oculographically. Magnetic resonance imaging showed bilateral border-zone infarcts, involving the frontal lobes and the superior part of the inferior parietal lobules.

Aged↗
PubMed1988

[Dolichoectatic intracranial arteries. Association with aneurysms of the abdominal aorta].

Dolichoectatic intracranial arteries (DIA) have been given several names, e.g. fusiform aneurysms, dolichomega-arteries. It is not an uncommon condition and it raises interesting points: 1) symptoms and signs result from compression (cranial nerve palsies; hydrocephalus) from ischemic or hemorrhagic episodes; 2) the diagnosis is made easier with CT since the arterial wall is often calcified; 3) the pathophysiology has long been assumed to be atherosclerotic in nature, but controversial assumptions are discussed; 4) associated arterial abnormalities are common: one of our cases and approximately half of the post mortem reported DIA were associated with aneurysm of the abdominal aorta. Two cases are reported here: 1) A 56 y/o male presented with progressive gait disorder, deafness and ischemic episodes. CT showed DIA and hydrocephalus. DIA involved the basilar artery, both intracranial carotid arteries, the abdominal aorta and probably one renal artery. A ventriculo-atrial shunt was performed unsuccessfully. Post mortem findings are reported; 2) A 52 y/o male had suffered from trigeminal neuralgia for about one year and from trigeminal permanent pain for two weeks. He had developed left hemiparesis and dysarthria. DIA involved the basilar artery and the left intracranial internal carotid artery. The right internal carotid artery and the right vertebral artery were hypoplastic. Clinical, radiographical and pathophysiological features are reviewed.

Aorta, Abdominal↗