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Biomedical subjects

F Dubas

Publications and source records attributed to F Dubas.

At least 73 records · Page 4Linked to original sources

[Sensory nerve involvement in X-linked bulbospinal amyotrophy (Kennedy syndrome). Contributions of electrophysiologic and histologic data].

Two new cases of X-chromosome linked bulbospinal muscular atrophy associated with gynecomastia (described by Kennedy in 1968) are reported. In one patient, an electrophysiological study and a muscle nerve biopsy were performed. Motor nerve conduction studies were normal but sensory action potentials were small or unrecordable in the absence of clinical sensory loss. Superficial peroneal nerve biopsy showed axonal lesions. These findings suggest that this disease is not purely due to degeneration of spinal motor neurons and is also associated with an axonopathy.

Electromyography↗

[Clinico-pathologic case of slowly progressive herpes simplex encephalitis without temporal necrosis].

A case of herpes simplex encephalitis (HSE) is reported. The patient experienced short term memory disorders and irritability progressing over 3 months, without seizures or fever. The CSF was normal. CT showed a small low density area in the right posterior orbito-frontal region. At post-mortem examination, one month later, the temporal cortex appeared largely spared by necrosis, which involved the posterior orbito-frontal areas. Cowdry type A inclusions, herpes virus like particles and fluorescent reaction with HSV1 monoclonal antibodies strongly supported the diagnostic. Such atypical cases of long duration have apparently seldom been reported. They suggest that HSE should be considered in the differential diagnosis of a subacute encephalopathy.

Aged↗

[Progressive spinal muscular atrophy and parathyroid adenoma. Clinico-pathologic study of a case].

A 82 year-old man died 6 years after the onset of a progressive spinal muscular atrophy. Post-mortem examination disclosed a parathyroid adenoma. Weakness and wasting were prominent in the proximal lower limbs. There were no fasciculations. Involvement of the medulla was mild and late. These clinical features were also present in 16 reported cases, which were improved by treatment of primary or secondary hyperparathyroidism. Our patient differs by the involvement of the hand muscles and the loss of tendon reflexes. Neuropathological study, as in one other reported case, showed a loss of anterior horn cells. Such cases underline that calcium metabolism must be studied in syndromes of spinal muscular atrophy.

Adenoma↗

[Ultrasonic study of 22 cases of carotid artery dissection].

The purpose of this study was to assess the value of duplex scanning and continuous wave Doppler velocimetry in the diagnosis and follow-up of ICA dissections. Between 1975 and 1988, 20 patients (11 women and 9 men; mean age 45 years) were admitted to the University Hospital of Angers for dissection of the ICA confirmed by angiography. The dissections were unrelated to direct cervical injury and were unilateral in 18 cases and bilateral in 2 cases. Six patients experienced transient cerebral ischaemic accidents (later completed in 2 cases) and 2 patients merely complained of ocular disorders of sympathetic origin. Fourteen patients were treated with heparin. All patients were examined by continuous wave Doppler ultrasound followed by duplex scanning. These examinations were performed 10 days on average before angiography. Continuous wave Doppler revealed signs of obstruction of the ICA in 95% of the cases: occlusion in 4 cases, tight stenosis in 13 cases and marked slowing of blood flow in the carotid and ophthalmic arteries in 4 cases. The acoustic signs of high or extensive ICA stenosis with reduced or retrograde ophthalmic artery blood flow were fairly suggestive of dissection. These results were completed by mode B which showed signs of dissection in 61% of the cases (tapering stenosis or occlusion, tubular ICA, separation of the vascular walls on rare occasions) and excluded atheromatous lesions in 81% of the patients. The tubular ICA image being non-specific was interpreted in relation to the clinical context and haemodynamic data, after discussion and exclusion of fibromuscular dysplasia, intracranial carotid stenosis causing severe reduction of blood flow and the exceptional hypoplasia of the ICA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Singular clinical form of intramedullary cavity revealed by a loss of proprioceptive sensation in the upper limbs].

A 47-year-old woman developed a progressive sensory deficit of the upper limbs. She lost perception of joint position, vibratory sense, skin-writing and stereognosis. Repeated tests by several examiners, up to 10 years after the onset, demonstrated normal pain and temperature sensation. The right hypoglossal nerve was involved at a late stage of the disease. CT and MRI showed an intramedullary cavity from C1 to T7. Somato-sensory evoked potentials from stimulation of the median nerves confirmed the bilateral impairment of the lemniscal pathways.

Arm↗

Ionic currents of smooth muscle cells isolated from the ctenophore Mnemiopsis.

The ionic currents of smooth muscle cells isolated from the ctenophore Mnemiopsis were examined by using conventional two-electrode voltage clamp and whole-cell patch clamping methods. Several separable currents were identified. These include: (1) a transient and (2) a steady-state voltage-activated inward current; both are tetrodotoxin (TTX) and saxitoxin (STX) insensitive, partly reduced by decreasing external Ca2+ or Na+ or by addition of 5 mM Co2+, D-600 or verapamil and are totally blocked with 5 mM Cd2+; (3) an early, transient, cation-dependent, outward K+ current (IKCa/Na); (4) a transient, voltage-activated, outward K+ current provisionally identified as IA; (5) a delayed, steady-state, voltage-activated outward K+ current (IK) and (6) a late, transient, outward K+ current which is blocked by Cd2+ and evident only during long voltage pulses. Despite their phylogenic origin, most of these currents are similar to currents identified in many vertebrate smooth and cardiac muscle preparations, and other excitable cells in higher animals.

Action Potentials↗

[Polyneuropathies with IgM monoclonal gammopathy. 12 cases].

12 cases of polyneuropathy with IgM monoclonal gammapathy are reported. An analysis of the clinical, electrophysiological, histological and immunological features of these cases and of those reported in the literature allows to distinguish 2 groups. In the first group (8./12 cases), the neuropathy showed clinical and electrophysiological features of a mainly demyelinating mechanism involving large fibers. Electromicroscopy disclosed a widening of the spaces between the lamellae of the myelin in half of these cases. A monoclonal deposit of IgM was demonstrated by direct immunofluorescence, on the remaining myelinated fibers in most cases. In this first group, the M-component always reacted with the myelin sheaths of a monkey's peripheral nerve. The results of indirect immunofluorescence were closely correlated with those of immunoblotting, which revealed an anti-M.A.G. (Myelin Associated Glycoprotein) activity. The second group is more heterogeneous: there was an predominantly motor neuropathy (1 case), an asymmetrical and painful neuropathy with an endoneural deposit of IgM (1 case). In 2 other cases which in no other ways differed from those of the first group, the M-component seemed devoid of antimyelinic activity. Nevertheless, the presence of IgM on the myelin sheaths of these 2 cases suggested a relationship between the neuropathy and the gammapathy. In both groups, results from the association of apheresis and chlorambucil were difficult to assess and vary greatly. Therapy appeared beneficent in half of the cases, but only one patient was markedly improved.

Adult↗

[Familial distal progressive spinal amyotrophy with asymmetry of the lower limbs].

Two cases of spinal muscular atrophy, localized on the lower limbs and strictly unilateral, in two half brothers, are reported. Such a distribution of clinical changes and such a hereditary transmission appear to be unusual in hereditary motor-neuronopathies. A recessive heterotopic transmission may be suspected. To our knowledge, it has been reported in Kennedy's disease only.

Adolescent↗

Chromatophore motoneurons in the brain of the squid, Lolliguncula brevis: an HRP study.

The location of the motoneuron somata controlling activity of the chromatophore muscles was studied in the squid Lolliguncula brevis. Retrograde transport of horseradish peroxidase from injection sites in the skin or in the mantle muscle established that the chromatophore motoneurons are situated in the subesophageal mass of the brain while at least some of the mantle muscle motoneurons are in the stellate ganglia. Motoneurons to chromatophores in the mantle have their somata in the posterior subesophageal mass, mainly in the chromatophore or fin lobes. Motoneurons to chromatophores in the head are located in the anterior pedal lobes and those to the chromatophores in the arms project mainly from the anterior chromatophore lobes. However, some neurons in the posterior chromatophore lobes project to the head or arm regions. A few cells in both the anterior and posterior chromatophore lobes project contralaterally. Somata in other lobes of the subesophageal mass are also labelled by injections in the skin or in the mantle muscle. Evidence presented here suggests that some of the neurons labelled outside the chromatophore lobes are chromatophore motoneurons.

Animals↗

Neural generator of P14 far-field somatosensory evoked potential studied in a patient with a pontine lesion.

Somatosensory evoked potentials (SEPs) to electrical stimulation of the right and the left median nerves were studied in a patient with a pontine lesion. At first there was mainly right medial lemniscus involvement. Four months later the left medial lemniscus was found to be also involved. SEPs to stimulation of the right median nerve had normal wave forms and latencies while N20 was lacking and P14 was abnormal after stimulation of the left median nerve in the first SEP record. N20 and P14 were absent with preservation of P9 and P11 after stimulation of both left and right median nerves in the second SEP record. Therefore the P14 component has been found abnormal, then absent, in a patient with a pontine lesion.

Adult↗

Nerve and muscle microvasculitis in peripheral neuropathy: a remote effect of cancer?

In a series of 50 cases in which nerve and/or muscle microvasculitis was seen on biopsy, seven were associated with malignancy. In two cases, the cancer was found after the discovery of microvasculitis. All patients exhibited sensory-motor neuropathy, which was often painful and asymmetrical, with a progressive course. ESR and CSF protein levels were always elevated. Motor conduction velocity was slightly reduced in three cases, unmeasurable in one case, and normal in three. Cancers involved were adenocarcinoma in five cases (three prostate and two lung), Hodgkin's disease in one and immunoblastic lymphadenopathy in one. A thorough search for cancer should be performed when microvasculitis is seen in nerve or muscle biopsy specimens, especially when ESR and CSF protein levels are elevated.

Adenocarcinoma↗

Localization and stimulation of chromatophore motoneurones in the brain of the squid, Lolliguncula brevis.

The relatively simple chromatophore system of the squid, Lolliguncula brevis, was studied with combined behavioural, morphological and electrophysiological methods in order to understand how the chromatophore patterns in the skin are organized at the level of the posterior chromatophore lobes (PCL). There are nine simple chromatic components of patterning in L. brevis. Retrograde transport of horseradish-peroxidase from chromatophores in the mantle skin established that the chromatophore motoneurones are located in the PCL. Focal threshold stimulation of the PCL in perfused, semi-intact preparations showed that the motor fields of individual chromatophore motoneurones are compact, including 2-60 chromatophores, generally of the same colour. Adjacent motoneurones in the lobe do not necessarily have adjacent motor fields in the skin.

Animals↗

Leukoencephalopathy in diffuse hemorrhagic cerebral amyloid angiopathy.

We have studied 12 patients with diffuse hemorrhagic cerebral amyloid angiopathy clinically and at postmortem examination. The brains in 8 patients had diffuse bilateral loss of myelin in the hemispheric white matter sparing the U fibers, corpus callosum, and internal capsules. The periventricular areas were predominantly affected. Microscopic examination of the white matter showed an association with subacute or chronic edematous lesions: spongiosis, swollen oligodendroglia, widening of the perivascular spaces with edema fluid or siderophages, hyalinization of the blood vessel walls, incomplete myelin loss, and astrocytic gliosis. Three of 8 autopsied patients had undergone computed tomographic examination, which showed bilateral hypodensity of the hemispheric white matter. The brains of 4 patients with illnesses of shorter duration showed only discrete but similar lesions in the centrum semiovale. These white matter changes are similar to those observed in Binswanger's subcortical encephalopathy. We suggest that a common mechanism of hypoperfusion of the distal white matter causes the leukoencephalopathy.

Aged↗

Evidence for L-glutamate as a transmitter substance of motoneurons innervating squid chromatophore muscles.

Motor nerve branches were stimulated in the dermis layer prepared from isolated pieces of dorsal mantle skin of the squid Lolliguncula brevis and the contractions of chromatophore muscle fibers were recorded with the aid of a photo-electric transducer. L-Glutamate (L-Glu), kainate and quisqualate caused a contracture and often repetitive twitch-like contractions. These effects were readily reversible. In the case of L-Glu application, twitches induced by single stimuli applied to motor nerves were enhanced and prolonged. The glutamate antagonists glutamic acid gamma-methyl ester, glutamic acid diethyl ester, D,L-2-amino-4-phosphonobutyrate and gamma-D-glutamylglycine prevented both nerve induced and L-Glu induced contractions. The NMDA-receptor agonists N-methyl-D-aspartate, L-aspartate and D-glutamate, and their antagonists alpha-aminoadipate and D,L-2-amino-5-phosphonovalerate were found ineffective. With the aid of saline media of different Ca and Mg content, it was possible to selectively eliminate one or all components of the effect of L-Glu. Tetrodotoxin abolished nerve induced contractile responses but did not interfere with the contracture caused by L-Glu. Intracellular electrical recording indicated that nerve stimulation causes EPSPs which do not give rise to spike discharges. The results are compatible with the hypothesis that L-Glu is a transmitter substance of the motoneurons that innervate chromatophore muscle fibers.

Animals↗

[Arteriopathic leukoencephalopathy (17 anatomo-clinical cases)].

Seventeen clinico-pathological cases of leukoencephalopathy due to vascular diseases are reported. All of them had diffuse, often spotty demyelination sparing the U fibers, the corpus callosum, the internal capsule and the optic radiations. Microscopic examination of the white matter showed the association of the following lesions: oedema, swollen oligodendroglia, spongiosis, incomplete loss of myelin, astrocytic gliosis with Rosenthal's fibers, widening of the perivascular spaces with oedema fluid or hemosiderin laden macrophages, thickening and hyalinization of the blood vessels walls. Among those cases, 8 were consistent with Binswanger's subcortical encephalopathy (5 males, 3 females, mean age at death: 64 years, mean illness duration: 6, 7 years); all of them were hypertensive and had lacunae in the basal ganglia, hemispheric white matter and pons. Another case could be considered as a cortico-subcortical chronic hypertensive encephalopathy (77 y.o., female, illness duration: 4 years); she was hypertensive and had small cortical infarcts and perivascular bleedings, lobar and cerebellar hematomas, but no amyloid deposits in the blood vessels walls. Eight patients (5 males, 3 females mean age at death: 72 years, mean illness duration: 5, 4 years, 6 normotensive, 2 hypertensive) had diffuse meningocortical amyloid angiopathy with multiple small cortical infarcts, small cortical perivascular bleedings, slit haemorrhages and one or more lobar hematomas. Four of them had numerous senile plaques and neurofibrillary tangles. To our knowledge such a leukoencephalopathy in cerebral amyloid angiopathy has not been yet pointed out. It was present in 8 out of 12 cases of diffuse haemorrhagic form of cerebral amyloid angiopathy observed in the Charles Foix Laboratory of la Salpêtrière, during the last 10 years. A common mechanism with hypoperfusion of the distal white matter and alteration of the blood brain-barrier is suggested for this leukoencephalopathy.

Aged↗

[Nerve and muscle microvasculitis: 50 cases].

Fifty consecutive cases of nerve and muscle microvasculitis (MV) seen on nerve and muscle biopsies were studied. These were observed in a 5 years period, among 1076 nerve and/or muscle biopsies performed in adult patients in the Laboratoire de Neuropathologie Charles Foix. The systemic necrotizing vasculitides, in which the arteries of diameter greater than 70 microns are involved, acute polymyositis, sarcoidosis and acute polyneuritis were not considered in this study. Mononuclear cell infiltration was the rule. It was associated to leukocytoclasis in 2 cases. No fibrinoid necrosis was seen. These changes were highly diagnostic when seen in the nerve or the connective tissue of the epi or perimysium. The etiology of these microvasculitides was mainly connective tissue diseases (42 p. 100) and, overall, panarteritis nodosa (16 p. 100), or malignancies (28 p. 100) which comprise 7 solid tumors and 4 lymphomas. Other cases were related either to systemic diseases (thromboangiitis obliterans, monoclonal dysglobulinemia, cholesterol embolus) or to local trauma. The relationship between MV and peripheral neuropathy was less obvious in 3 cases of mononeuritis multiplex associated with diabetes mellitus and in 3 cases of acute idiopathic and regressive mononeuritis multiplex. In 5 cases, no cause was found.

Adult↗

[Retinal, muscular and cutaneous cholesterol emboli. Progressive encephalopathy].

A 73 year-old man experienced left monocular blindness and transient right hand clumsiness. A left carotid arteriogram was performed 4 days after admission. Immediately following arteriography, there was a right hemiparesia and dysphasia. After 24 hours, the abnormalities resolved. The patient was treated with heparin. During the following weeks, he became gradually drowsy and confused. Pseudo-bulbar palsy and astasia appeared after a fluctuating but progressive neurological course. The combination of systemic symptoms, high sedimentation rate, renal failure, livedo reticularis and purple toes suggested necrotizing angiitis. With corticosteroid treatment, there was a slight improvement of systemic symptoms. Cholesterol emboli were seen in both fundi. Cholesterol embolization was proved by identifying the biconcave cholesterol crystal clefts in muscle and skin biopsies. The subsequent course was marqued by continuous neurological deterioration. The patient became stuporous and died 7 months after admission. Despite the lack of central nervous system pathological study, the clinical picture was highly suggestive of cerebral cholesterol embolism. A few cases have been reported, with only eight well-documented clinical descriptions. Clinical signs and symptoms were closely similar to those of the present case. Anticoagulant therapy of cholesterol emboli has been unsuccessful. In the present case, the onset of embolization was temporally related to anticoagulation.

Aged↗