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Biomedical subjects

C Julien

Publications and source records attributed to C Julien.

At least 109 records · Page 6Linked to original sources

Measurement of urinary catecholamines and their catechol metabolites and precursor by liquid chromatography with column-switching and on-line fluorimetric and electrochemical detection.

A new method is described for the determination of catecholamines and their precursor (3,4-dihydroxyphenylalanine), and separately of their catechol metabolites (3,4-dihydroxymandelic acid, 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxyphenylethylene glycol and 3,4-dihydroxyphenylethanol) in urine. After a two-step pretreatment involving ethyl acetate extraction and adsorption onto alumina, the separation is performed by ion-pair reversed-phase high-performance liquid chromatography. A column-switching system enables complete separation of the most polar compounds without increase in the total analysis time. The column eluates are monitored with both fluorimetric and amperometric detectors, the relative responses of which are used as an index of peak purity. Reference values for twelve healthy adults are given.

Adult↗

[Acute nonmyeloid leukemia in adults. Study of membrane antigens and terminal transferase. Diagnostic and prognostic value].

Between January, 1982 and April, 1983, 92 adult patients with acute leukaemia were investigated in our department. According to classical criteria (cytology and optical cytochemistry), 34 were classified as "non-myeloid". These were further tested with a panel of monoclonal antibodies against cell membrane, including ALB1-2 (anti-CALLA), ALB6 (anti-p24), ALB7-8-9 (BA1), OKT and HLA DR; they were also tested for E rosettes, Slg and terminal transferase (TDT). When all these markers but HLA DR were negative, patients were investigated for ultrastructural peroxidases which were found to be present in 2 cases. Among all non-myeloid leukaemias, 18 (56%) were CALLA-positive and TDT-positive acute lymphoblastic leukaemias (ALL), 2 (6%) were ALL T, 7 (22%) were CALLA-negative and TDT-positive ALL and 5 (16%) were acute leukaemias null for our markers, a phenomenon the significance of which is discussed. Patients with the CALLA-negative TDT-positive phenotype were peculiar with regard to age (mean: 50 years), female predominance, L2 cytological pattern according to the FAB classification, good prognosis (complete remission in 100% of the cases) and median survival (p less than 0,03).

Adolescent↗

Stimulus--response relationships during locomotion.

Crossed hind limb responses to high intensity stimulation of the superficial peroneal nerve in the cat were studied under various conditions. In precollicularly decerebrate cats walking on a treadmill, the same stimulus train evokes a crossed extension response during the contralateral stance phase and a crossed flexion response during the contralateral swing phase. In acute spinal cats (Th 13) injected with clonidine, a similar stimulus train can evoke a crossed extension response when the limb is manually placed in flexion and a crossed flexion response when the limb is positioned in extension. During "fictive" locomotion, induced in spinal paralyzed cats by nialamide an L-DOPA, the same stimulus may increase the amplitude and (or) the duration of crossed flexor or crossed extensor activity (in-phase responses). In some instances in these preparations, the crossed responses may be out-of-phase with the central rhythm. It is concluded that crossed hind limb responses during locomotion are selected by both central and peripheral mechanisms.

Animals↗