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Biomedical subjects

C Quincy

Publications and source records attributed to C Quincy.

8 recordsLinked to original sources
PubMed1991

Increased serotonin platelet uptake after tianeptine administration in depressed patients.

Tianeptine is a new antidepressant drug reported to enhance serotonin (5-hydroxytryptamine [5-HT]) uptake in rat brain. The effect of tianeptine on 5-HT platelet uptake was studied in 10 depressed patients treated for 28 days. Tianeptine increases Vmax of 5-HT platelet uptake during treatment without inducing any change in Km. As early as 2 hr after the first administration, Vmax increased significantly (+23%, alpha = 0.01). Although of a lesser magnitude, 5-HT platelet uptake remains increased after chronic administration (+14% on day 10 and +13% on day 28). This suggests that tianeptine affects 5-HT platelet uptake sites, either directly or via an action on modulators of 5-HT uptake. These results, in contrast with the action of other tricyclic antidepressants, confirm the original action of tianeptine on 5-HT platelet metabolism.

Adolescent↗
PubMed1991

[Platelet serotonin concentration in children under 5 years of age].

High platelet serotonin concentrations have been reported in children with early infantile autism. However, as yet there are no reference values regarding platelet serotonin in normal infants and young children so that it remains difficult to define the exact significance of this finding. We report here with the platelet serotonin concentration found in 57 infants and children (20 girls, 37 boys) ranging in age from 10 days to 5 years old. Our results show that mean platelet serotonin concentrations in infants and young children are significantly greater than mean values obtained in older children (+11%) and neonates in the umbilical cord (+64%). No significant variations were found relating to sex, leucocyte count and platelet count. There therefore appears to be a physiological elevation of platelet serotonin concentration in infants and young children, and this has to be taken into consideration in the interpretation of the elevated values found in cases of infantile autism.

Aging↗
PubMed1990

Determination of reference values for serotonin concentration in platelets of healthy newborns, children, adults, and elderly subjects by HPLC with electrochemical detection.

We adapted a high-performance liquid chromatographic method with electrochemical detection (Clin Chim Acta 1984;139:1-12) to the determination of platelet serotonin. We used this method to determine platelet serotonin reference values in a healthy population, measuring platelet serotonin concentration in the following subjects: 31 newborns (16 girls, 15 boys); 41 children (11 girls, 30 boys), ages 20 months to 15 years; 56 adults (26 women, 30 men), ages 20 to 58 years; and 20 elderly subjects (16 women, four men), ages 65 to 94 years. There was no significant difference in platelet serotonin concentration between sexes in each age group. However, significant changes (P less than 0.001) were observed between the newborns (mean +/- SD: 1.67 +/- 0.74 nmol/10(9) platelets) and the children (4.09 +/- 1.04) or the adults (3.81 +/- 0.87). Moreover, the platelet serotonin concentration in the elderly subjects (2.57 +/- 1.12) was significantly (P less than 0.001) lower than in the adults and children and significantly higher (P less than 0.01) than in the newborns. Such age-related differences must be taken into consideration when data from neurological or psychiatric patients and control subjects are compared.

Adolescent↗
PubMed1979

[Sensitive method for continuous detection of peptides and proteins using the biuret reaction and a copper-Sephadex reactor (author's transl)].

We describe a detection method relying both on the copper displacement from a Sephadex gel by peptides and proteins, and on the subsequent colorimetric determination of the complexed copper. The system described is fully automated and it permits a continuous analysis of column effluents. The choice of cuprizone as a detecting reagent for copper, enables one to bring the detection limit down to 200 ng for albumin and 60 ng for alanylglycylglycin. The specificity of the method is the same as the biuret reaction. Some examples of the possible applications are given.

Biuret Reaction↗
PubMed1976

[Multiple sclerosis with reduced and with normal levels of complement in the blood. Clinical and genetic correlation].

The authors describe the results of immunological assay of complement factors C3, C4 (the usual path of activation of complement) and of B factor (the alternate path of activation) in 61 multiple sclerosis patients not receiving corticoids, 52 normal controls and 217 patients with other neurological disorders. Hypocomplementaemia (fall in factor C3 related to a fall in total haemolytic activity) was found in 29.5 p. 100 of the patients not on corticotherapy at the first assay, and in 36 p. 100 of the patients when repeated assays were carried out. Hypocomplementaemia is significantly more frequent in multiple sclerosis than in the normal population (0 p. 100) and in neurological patients (9.6 p. 100). In 13.1 p. 100 of the multiple sclerosis patients there was a decrease in B factor: 50.3 p. 100 of the multiple sclerosis patients exhibited no quantitative abnormality of the main factors of complement (normocomplementary multiple sclerosis). The group of multiple sclerosis patients with hypocomplementaemia was characterized by the incidence of other abnormalities in the complement system: cleavage of the C3 factor and a fall in B factor in 60 p. 100 of the cases. A more frequent increase in IgE and measles antibodies was found also while the normocomplementary multiple sclerosis patients more frequently had higher levels of IgA. Genetically, the group with hypocomplementaemia is related to a significant increase in the incidence of the HL-A W18 group while the normocomplementary multiple sclerosis patients appear closely related to the HL-A7 group. Familial investigations show that hypocomplementaemia is usually present in the ascendents and collaterals and that it seems to be transmitted with the HL-A haplotypes. Four families gave evidence of transmission with the W18 group. This transmission sometimes occurs together with transmission of an increase in IgE and/or of measles antibodies. In two pedigrees, one of the ascendents carried in his serum an activator of the alternate path of complement. There does not appear to be any prognostic difference between the two groups. In multiple sclerosis with hypocomplementaemia, the facts suggest a complex immunological abnormality, transmitted genetically to the subject and existing prior to the illness, comprising both elements of deficient and excessive immune response. The recognized presence of a gene of immunological reactivity and of genes of synthesis of complement on the 6th chromosome, in proximity with genes of histocompatability (HL-A and M.L.C.) provides a theoretical basis for this supposition.

Adult↗