[Thrombopenia and fatal intracerebral hemorrhage caused by pentosan polysulfate].
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Aged↗
Biomedical subjects
P Benoit
Publications and source records attributed to P Benoit.
Calcitonin gene-related peptide enhances the rate of desensitization of the nicotinic acetylcholine receptor in cultured mouse muscle cells.
Calcitonin gene-related peptide (CGRP) is a neuropeptide that coexists with acetylcholine in spinal cord motoneurons. The effects of CGRP on the functional properties of the nicotinic acetylcholine receptor (AcChoR) were examined by electrophysiological methods. Using the whole-cell patch-clamp technique and a mouse cell line derived from soleus muscle, we found that CGRP produces a progressive and reversible enhancement of the rapid-decay phase of AcChoR desensitization. Single-channel data further show that CGRP decreases acetylcholine-activated channel opening frequency. This decrease occurs when CGRP and acetylcholine are applied on different cell-surface areas and thus is likely mediated by a second-messenger system. CGRP is also shown to increase cAMP accumulation in this cell line. The effects of CGRP on macroscopic acetylcholine-activated currents are mimicked by external application of forskolin (10 microM) or by internal perfusion of the cell with cAMP (1 microM). In both these cases, further application of CGRP produces no additional enhancement of AcChoR desensitization. These results suggest that, on mouse muscle cells, CGRP regulates AcChoR desensitization by a mechanism that involves, at least in part, cAMP-dependent phosphorylation of the AcChoR.
Animals↗
CD9 antigen: will platelet physiology help to explain the function of a surface molecule during hemopoietic differentiation?
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Antigens, CD↗
[Hemodynamic effects on intravenous propafenone in hypertrophic myocardiopathy].
None of the medical treatments of hypertrophic cardiomyopathy is perfect. In the present study conducted on 11 patients with hypertrophic cardiomyopathy in whom the usual treatments were either ineffective or badly tolerated, the haemodynamic effects of propafenone administered intravenously were investigated. The drug was injected centrally in doses of 2 mg/kg over 10 minutes, then by continuous intravenous infusion of 1.5 mg/min during 30 minutes. Various parameters were recorded before and after propafenone treatment by right and left cardiac catheterization. This anti-arrhythmic drug, which has beta-blocking and amiodarone-like properties, reduced left intraventricular obstruction but had no beneficial effect on diastolic function. The baseline and induced left intraventricular gradients were reduced from 30.4 to 17.7 mmHg and from 74 to 43 mmHg respectively. Diastolic function values showed a fall in dp/dt min from 1470 to 1307 mm/sec and an increase in T value from 0.066 to 0.084. The use of propafenone in hypertrophic cardiomyopathy must be accurately determined by long-term oral studies.
Adolescent↗
[Borrelian meningoencephalomyelitis. A case].
A 22-year old man had spastic paraparesis and cerebellar syndrome of 5 months duration. CSF showed lymphocytosis, elevated protein content, hypoglycorachia, hypochlorurachia and oligoclonal banding. CT scan and MRI were normal. Extensive laboratory procedures disclosed no bacterial, viral, fungic, parasitic or inflammatory disease. Anti-Borrelia burgdorferi antibodies were present in blood (1/4000) and in CSF (1/1024). With antibiotics (penicillin G 20 millions units per day for 10 days, followed by latamoxef 1.5 g per day for 3 months) and prednisone (50 mg per day for 2 months), the cerebellar signs disappeared, the paraparesis improved and the CSF abnormalities disappeared; blood and CSF anti-Borrelia antibody levels decreased. This case is an example of a severe form of CNS impairment by Borrelia burgdorferi. In Europe, most reports show progressive para- or tetraparesis with, sometimes, intellectual, cerebellar or cranial nerve impairment. In some cases, the signs are less diffuse or more acute. Lymphocytic meningitis is present with hyperalbuminorachia and oligoclonal banding; hypoglycorachia is mentioned in only one other report. Diagnosis is made by high blood and CSF antibody titers and demonstration of local synthesis. As in syphilis, borrelian meningoencephalomyelitis could be the third stage of the disease. Its treatment, often disappointing, consists of antibiotics (penicillin G or latamoxef) and in some cases corticosteroids.
Adult↗
Mechanisms of the mAb ALB6(CD9) induced human platelet activation: comparison with thrombin.
A CD9 monoclonal antibody described to aggregate human platelets was studied on different platelet functions in order to determine its mechanism of action. After a lag phase of 35 sec the mAb ALB6 induced a transient decrease in 32P-polyphosphoinositides, synthesis of 32P-phosphatidate (PA), phosphorylation of myosin light chain (P20) and of 43 KDa protein (P43) and the release reaction. Final biological and metabolic effects of ALB6 thus appear similar to that of thrombin but three differences bring additional information: (i) the lag phase, (ii) the kinetic of ALB6-induced release is identical for all granules whereas the release of dense granules is faster when induced by thrombin. (iii) no external Ca++ is required for ALB6 induced-activation.
Antibodies, Monoclonal↗
Renal metastases from neuroblastoma. Report of two cases.
Neuroblastoma is one of the pediatric cancers that has the most unpredictable evolution. It can metastasize to almost any organ, but intrarenal metastases have never been reported. We report 2 such cases: the first patient had a left adrenal neuroblastoma completely resected 10 months before routine follow up ultrasound and CT scan demonstrated 3 right intrarenal metastases. The second patient was being investigated for a left abdominal mass when one left intrarenal metastasis was found during the same CT scan. An intrarenal mass found during investigation for staging or follow up of neuroblastoma should then be considered as a metastase until proven otherwise.
Adrenal Gland Neoplasms↗
Evidence for a multiple innervation of cerebellar Purkinje cells by climbing fibers in adult ferrets infected at birth by a mink enteritis virus.
Newborn ferrets were inoculated with Mink Enteritis virus (parvovirus). They developed a cerebellar hypoplasia and presented severe ataxia. Electrophysiological study by intracellular recordings in the cerebellar cortex demonstrates that in these ferrets, like in other mammals, Purkinje cells deprived from granule cell input during development remain multiply innervated by climbing fibers in the adult.
Animals↗
Lateral gaze disturbance in a case of Wallenberg's syndrome.
A 63-year-old Caucasian man was admitted for Wallenberg's syndrome following a left vertebral artery thrombosis. In addition to the classical symptoms, an axial lateropulsion to the left and ocular motor disorders (vertical diplopia, tonic deviation of the gaze to the left, skew deviation and horizonto-rotatory nystagmus) were present. These clinical signs are unusual, but in common Wallenberg's syndrome, neurophysiological tests often reveal slight abnormalities of oculomotor function: impairment of jerks, skew deviation, lateral deviation of the gaze in darkness. Interruption of cerebellar pathways is thought to be the cause of these symptoms. Their existence does not seem to change the outcome of these cases.
Eye Movements↗
Chondroma of the cervical spine. Case report.
The authors report a case of cervical chondroma presenting with a syndrome of spinal cord compression in a 76-year-old woman. Total surgical removal of the lesion was followed by partial neurological recovery. Chondromas of the vertebral column are rarely reported in the literature.
Aged↗
[Propafenone in ventricular extrasystole in elderly patients. Tolerance and efficacy].
The tolerance and efficacy of propafenone were studied in cases of chronic ventricular extrasystoles of the elderly (age greater than 70 years). Only patients presenting more than 1,000 extrasystoles per day and requiring a treatment, were included in this study. Patients presenting non-compensated cardiac insufficiency, hypotensive patients, patients with conduction disorders without pacemakers as well as patients presenting a severe renal or hepatic insufficiency, were excluded. After making sure that the rhythm disorder was chronic, a control Holter was performed, then, 600 mg of propafenone per day, in 3 doses were prescribed for 5 days. On the 5th day, a Holter was performed as well as a blood propafenone level. Some patients received then 900 mg per day with a new Holter and plasma propafenone titration on the 10th day. 11 patients were studied in this fashion. The tolerance to 600 mg was good in 10 out of 11 cases. The efficacy, appreciated by the decrease of the number of isolated ventricular extrasystoles (-69%), doublets (-95%), triplets (-98%) and salvos of ventricular tachycardias (-100%), was excellent in 6 cases, average in 2 cases and mediocre in 3 cases. Increase of the dosage to 900 mg does not improve significantly the anti-arrhythmic efficacy while the side effects seem more frequent. It is not possible to establish a relationship between plasma concentrations and efficacy. At a dosage of 600 mg per day, propafenone is therefore effective in the treatment of ventricular extrasystoles in elderly patients and its tolerance is good. Higher doses are not advisable as they seem much less well tolerated without any additional advantage.
Aged↗
[Dilated cardiomyopathy: electrocardiographic forms].
The shape of the QRS complex was analyzed in 90 cases of dilated cardiomyopathy and was divided into 6 electrocardiographic types which may be interpreted as follows: A predominant S wave in V2, V3 and V4 leads, surrounded by a reduced QRS voltage in the other leads was the most frequent characteristic pattern, being found in 31 cases (34.4%). This pattern coexisted with a lack of R wave progression from V1 to V4, with primary disorders of ST-T and with alterations in P wave. The deep S wave is probably due to a growth of vectors in the base of the left ventricle and in the septum in response to lesions in the rest of the myocardium. Second in frequency (22.2%) came left bundle branch block, with 20 cases. If to these are added the 19 cases of left anterior half-block observed, dilated cardiomyopathy appears as the major cause of the cardiac pathology that partially or completely interrupts the left branch. These cases also show that the lesions predominate in the left ventricle. The 14 cases (15.5%) of QS with elevated and convex ST-T betray extensive areas of fibrosis or necrosis. This pattern is characteristically located at the apex of the heart and associated with ventricular tachycardia. In 11 cases (12.2%) the QRS complex was normal in shape but associated with depressed ST-T and atrial disorders. This shows that the ventricular myocardium which produces QRS is neither badly damaged nor hypertrophic, but that repolarization is highly sensitive to the constant alterations of the subendocardial layers observed in dilated cardiomyopathy. Left ventricular hypertrophy was seen in 9 cases (10%).(ABSTRACT TRUNCATED AT 250 WORDS)
Arrhythmias, Cardiac↗
[Aspects of the development of multiple sclerosis].
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Humans↗
[Hypokalemia with severe rhythm disorders induced by Vichy water].
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Arrhythmias, Cardiac↗
Increase of neurite-promoting activity for spinal neurons in muscles of 'paralysé' mice and tenotomised rats.
Various lines of evidence from in vivo and in vitro experiments suggest that muscle-derived factors may enhance the survival and axonal outgrowth of spinal neurons. Our previous results using cultures of embryonic spinal neurons showed that denervation of skeletal muscle increased levels of a neurite-promoting activity in soluble muscle extracts. Here, two other experimental models in which muscle activity was also lowered were investigated. The mutant mouse 'paralysé' exhibits a spontaneous regression of motor nerve endings, with concomitant paralysis. In 'paralysé' mutant muscle extracts, specific neurite-promoting activity was up to 10-fold higher than in extracts prepared from control littermates. Tenotomy is known to retard the regression of polyneuronal motor innervation in skeletal muscle from neonatal rats. Three days after operation, levels of neurite-promoting activity were increased 2-fold with respect to total protein. These results suggest that skeletal muscle activity might regulate the synthesis of molecules affecting nerve growth.
Age Factors↗