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Biomedical subjects

B Laurent

Publications and source records attributed to B Laurent.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Chronic peripheral neuropathies with corticosensitive heredodegenerative aspects: 2 cases].

Two cases of peripheral neuropathy beginning in childhood are reported. Both had features suggestive of HMSN with pes cavus and kyphoscoliosis. Familial history of HMSN type I was present in 9 members of the kinship in case 1. In case 2, a mild neuropathy without pes cavus was present in the father. Case 1 developed four relapses of ascending sensory-motor deficit with conduction blocks suggestive of a superimposed chronic inflammatory polyneuropathy (CIP) which improved under prednisone. In case 2, the course was progressive with a severe proximal and distal motor weakness and sensitive disturbances. CSF protein concentration was high. Nerve biopsy showed rare onion bulbs and intense demyelination. These results joint to the unspecificity of the father's neuropathy are consistent with a probable childhood. CIP which improved under prednisone. These two cases indicated that in some patients with unusual symptoms for HMSN, prednisone should be considered and that the physiopathology of these neuropathies is probably heterogeneous.

Child↗
PubMed1989

[Pure agraphia. Apropos of 2 cases].

Pure agraphia is a disorder of written language without aphasia, alexia or apraxia. Its existence has long been disputed. We report 2 cases due to a left parietal hematoma. In the first patient, with a deep precuneate lesion, agraphia included disorders in handwriting and orthographic problems in copying or writing from dictation with the two hands. The second patient, with a lesion of the postero-inferior part of the left angular gyrus, made errors in choice and combination of letters during dictation, whereas these same letters were well-written and copying was normal. The first cases of pure agraphia were ascribed to frontal lesions and then confusional states. Current opinion tends to implicate parietal lesions of various types: superior or inferior, internal or external. Findings in the present 2 cases and those reported indicate that pure parietal agraphia is heterogeneous.

Aged↗
PubMed1988

[Dissecting aneurysm of the intracranial vertebral artery. An anatomo-clinical case].

A 64 year old patient with a cardiac prosthesis and receiving antivitamin K therapy presented with a right bulbar syndrome. Based on absence of meningeal signs and hemorrhage on CT scan heparin therapy was instituted. Fatal coma developed two and a half days later. Autopsy findings included a right lateral bulbar infarct and meningeal hemorrhage, predominant around a fusiform dilatation of the end of the right vertebral artery. Serial sections showed a large dissecting aneurysm between media and adventitia communicating with an intimal tear. Among intracranial dissecting aneurysms those of vertebrobasilar localization have the peculiarity of being subadventitial in some cases, with a subsequent enhanced risk of hemorrhagic complications. The use of anticoagulants appears contraindicated in these cases, even if their clinical expression is suggestive of an infarct. Their etiology is often unknown.

Aortic Dissection↗
PubMed1987

[Amnesic ictus and cerebral blood flow].

Cerebral blood flow determinations using the Xenon inhalation test in two patients with transient global amnesia showed overall decreases during the attack with a more marked fall in temporal-inferior frontal flow in one case and in temporal flow in the other. In the latter patient the temporal anomaly was reversible after naloxone injection but clinical improvement was lacking. Blood flow determinations in a further patient with transient global amnesia, after 2 mg of ergotamine tartrate plus caffeine, showed a global decline in flow without focal anomaly, with recovery after ten days. Values obtained in two other patients 24 and 38 hours respectively after typical transient global amnesia attacks were normal. The effect of naloxone appears related to a direct neuronal action although the role of endorphins in this affection is not conclusive. Comparison of these anomalies with those noted by Reichle with position emission tomography imaging suggests a primary neuronal mechanism.

Aged↗
PubMed1987

Live poliovirus vaccine in patients with chronic glomerulonephritis: effects on renal function and specific antibody response.

Twenty-one patients with chronic glomerulonephritis (GN) (5 with renal failure) received three doses of live trivalent poliovirus vaccine administered orally. The effect of the polio vaccination on the renal function and the titers of antibodies to poliovirus were studied. No significant consequence was observed in renal disease. Before vaccination, titers of poliovirus type 1 and 3 antibodies were significantly decreased as compared to healthy adult subjects. After vaccination, the patients exhibited a significant rise in poliovirus antibody titers for the three serotypes, although some of them failed to develop a fourfold or greater antibody rise to at least one of the three serotypes, especially in the group of patients with renal failure. These results indicate that live poliovirus vaccination is not deleterious in patients with GN and can provide a good protection.

Adolescent↗
PubMed1986

[X-ray computed tomography in central pontine myelinolysis. 2 cases].

Two cases of central pontine myelinolysis were studied by computerized tomography (CT). One patient had chronic alcoholism, the other porphyria variegata; both initially presented with water-and-electrolyte disorders, notably hyponatraemia. The neurological disorders consisted of acute pseudobulbar syndrome which totally regressed within 15 days to 1 month. CT demonstrated a low density area in the pons, extending to the mesencephalon in one case. Despite clinical cure, this low density persisted for 16 and 20 months respectively, counting from the onset of neurological symptoms. In central pontine myelinolysis, CT images only are of diagnostic value in cases with suggestive neurological symptoms and aetiology. CT can recognize minor forms of the disease and confirms that in some cases severe forms may follow a regressive course.

Adult↗
PubMed1986

Cerebrospinal fluid and serum immune complex in acute inflammatory polyneuritis. Detection by Clq binding assay.

Immune complexes (IC) were assessed in serum and CSF from 11 patients with acute inflammatory polyneuritis (AIP). An 125 I-labeled Clq binding assay (Clq BA) was used. IC were present in the sera of four patients and in the CSF of six. CSF-Clq BA of AIP (Group 1) were compared with 12 patients with other inflammatory neurological diseases (Group 2) and 22 patients with non-inflammatory neurological diseases (Group 3). There was only a significant difference between Group 1 compared to Group 3 (p less than 0.05). Serum and CSF IC did not correlate either with blood-brain barrier lesions or with immunoglobulin deposits in sural nerve biopsy.

Acute Disease↗
PubMed1986

IgA mesangial deposits in C3H/HeJ mice after oral immunization with ferritin or bovine serum albumin.

In order to study an experimental model of IgA nephropathy, C3H/HeJ mice which are high IgA responders were strongly immunized orally with ferritin and compared to syngeneic C3H/eB. C3H/HeJ exhibited a significant increase of total IgA level in the serum and of IgA deposits in the mesangium. However the low level of IgA antibody to ferritin detected in the serum and the unsuccessful search for ferritin and antibody to ferritin in the glomeruli suggest that strong oral immunization of C3H/HeJ mice leads to high level of non specific IgA in the serum and deposition of IgA in the kidney.

Animals↗
PubMed1986

[Thalamic pain: critical study of 43 cases].

Apart from hyperpathia, which is an entity in itself, thalamic pain presents a clinical spectrum of variable quality and intensity that justifies the description of "thalamic pains". Their mechanisms can be related to two basic mechanisms. The first involves the dependence of the thalamus to the afferent spinothalamic system. A lesion of the lemniscal system resulting from lesions of the thalamic sensory nuclei--capable of provoking a syndrome of paresthesia-hyperpathia (P-HI)--provokes a loss of gate control normally ensured by this discriminatory system and thus releases the pathologic nociceptive reactivity. Some authors think that the thalamic lesion alters the activity of control of the VPL nucleus on the lumbosacral spinothalamic tract. This concept considers thalamic pain as identical with brain stem spinothalamic pain provoked by exclusion of the control system arising in the giant-cell reticular nucleus and projecting onto onto the posterior horns. However, most cases of thalamic pain appear to be dependent on another mechanism involving the thalamocortical loop. In this case the thalamic sensory nucleus lesion is involved insofar as it implicates the reciprocal thalamocortical connections and the reticular nucleus. Involvement of the Th-C-Th loop as the ultimate representative of the lemniscal gate control is supported by "pseudo-thalamic" pains related to cortico-subcortical lesions with abolished SEP. But the numerous cases of painful thalamic syndromes with lemniscal sparing and normal SEP lead to incriminate a lesion of a specific thalamocortical control system for pain.(ABSTRACT TRUNCATED AT 250 WORDS)

Afferent Pathways↗
PubMed1985

Cellular retinoid binding proteins.

The cellular retinol-binding protein (CRBP) and the cellular retinoic acid binding protein (CRABP) have similar physicochemical characteristics. The amino acid sequences of rat CRBP and bovine CRABP have been elucidated and they display 40% sequence identity. Both protein sequences appear to be evolutionarily highly conserved. The amino acid sequence of human CRBP, deduced from a cDNA-clone, is 96% identical to the rat CRBP sequence. CRBP and CRABP are members of a protein family, all members of which may bind hydrophobic ligands and interact with membrane components. All members of the protein family are probably related in tertiary structure and might interact with membrane components through two regions with a high probability for alpha-helix. The tissue distribution of CRBP and CRABP, together with their relation to lipid transporting proteins suggests that CRBP and CRABP are cellular transporting proteins for retinol and retinoic acid, respectively.

Amino Acid Sequence↗
PubMed1985

Sulfate and glucuronide conjugates of 3-methoxy-4-hydroxyphenylglycol (MHPG) in urine of depressed patients: central and peripheral influences.

A number of arguments support the hypothesis that changes in urinary levels of MHPG sulfate and MHPG glucuronide respectively reflect central and peripheral norepinephrine metabolism (NE) in man. In this line, the daily excretion of both conjugates was determined in 36 depressed women comparatively to 23 healthy women in order to assess the extent and the central or peripheral location of their possible NE dysfunction. About 80% of the patients suffering from depression (6 endogenous, 19 neurotic, 11 reactive depressions) exhibited a central NE defect, as evidenced by low MHPG sulfate, and many of them had probably also diminished sympathetic activity, as suggested by low MHPG glucuronide. Clinical symptoms possibly related to the psychic state (mood alteration) or associated to sympathetic changes (anxiety, motor activity) respectively altered sulfate or glucuronide excretion. Sulfate (S) and glucuronide (G) MHPG excretions were significantly correlated in healthy subjects (r = 0.53, p = 0.01), thus supporting the concept of the functional link between central NE activity and sympathetic function. Such a correlation was not found in depressive patients. However the lack of significant changes in the mean ratio S/G in the patient sub-groups suggests that as in normal subjects, central and peripheral NE activity are linked in depressed patients, but other factors may also modify sympathetic function. Taken together our data show that the separate assay of sulfate and glucuronide MHPG provides a better picture of NE dysfunction in depression than total MHPG measurement.

Adjustment Disorders↗
PubMed1985

[Lymphocyte subpopulations of the blood and cerebrospinal fluid in acute polyradiculoneuritis. Study of 14 cases using monoclonal antibodies].

The T lymphocytes in blood and CSF of 14 patients with acute polyradiculoneuritis were studied using the OKT series of monoclonal antibodies. Results were compared with findings in two control groups. Three patients with cytomegalovirus infection showed elevation of circulating OKT 8. A significant increase in the mean ratio OKT 4/OKT 8 was noted in all other cases, corresponding in 4 of the 11 patients to a reduction in number of OKT 8 lymphocytes. The CSF was normal in 3 of the 14 cases.

Acute Disease↗
PubMed1985

[Benign acute cerebral angiopathy. 4 cases].

Presenting symptoms in 4 patients with acute benign cerebral angiopathy were headaches over several days, with a transient neurologic disorder in two cases. Angiography showed diffuse and segmental distal narrowing alternating with dilatations. In one patient, the radiologic anomalies persisted to a milder degree in the same region 2 months later, while the reduced cerebral blood flow failed to return to normal. The pathophysiology of this syndrome would appear to result initially of vasospasm in particularly reactive subjects, especially young women. Its cause appears to vary from one case to another: post-partum disorders, infection or inflammation, meningeal hemorrhage, paroxysmal hypertension. Adjuvant factors could be unusual effort, medication or a migraine context. In spite of this pathogenetic uncertainty this angiopathy in usually considered as an isolated, benign and non-relapsing disease.

Acute Disease↗