Biomedical subjects

J Berkhout

Publications and source records attributed to J Berkhout.

16 recordsLinked to original sources

PubMed2003

Clinical pharmacokinetics of cefamandole and ceftazidime administered by continuous intravenous infusion.

In view of the results of animal studies as well as theoretical considerations, continuous administration of beta-lactam antibiotics should be superior to intermittent administration because of the close relationship between efficacy and the duration of time in which the concentration of unbound antibiotics in plasma remains above the MIC. The aim of the present study was to establish the pharmacokinetic parameters of cefamandole and ceftazidime for patients receiving these cephalosporins by continuous infusion. The interindividual differences in the concentrations in plasma at the steady state were mainly attributable to variations in renal function, as estimated by the rate of creatinine clearance. Using these results, we derived formulas for both cephalosporins that can be used to determine on an individual basis the total daily dose needed to obtain a therapeutic concentration in plasma. These formulas were tested with a group of subsequent patients and proved to be practical and fairly reliable. For some patients, a correction for a possible underestimation of the renal clearance at presentation might be required.

Adult↗

PubMed2001

Microparticles from patients with multiple organ dysfunction syndrome and sepsis support coagulation through multiple mechanisms.

AIM: We investigated the occurrence and thrombin generating mechanisms of circulating microparticles (MP) in patients with multiple organ dysfunction syndrome (MODS) and sepsis. METHODS: MP, isolated from blood of patients (n = 9) and healthy controls (n = 14), were stained with cell-specific monoclonal antibodies (MoAbs) or anti-tissue factor (anti-TF) MoAb and annexin V, and analyzed by flow cytometry. To assess their thrombin-generating capacity, MP were reconstituted in normal plasma. The coagulation activation status in vivo was quantified by plasma prothrombin fragment F1+2- and thrombin-antithrombin (TAT) measurements. RESULTS: Annexin V-positive MP in the patients originated predominantly from platelets (PMP), and to a lesser extent from erythrocytes, endothelial cells (EMP) and granulocytes (GMP). Compared to healthy controls, the numbers of annexin V-positive PMP and TF-exposing MP were decreased (p = <0.001 for both), EMP were decreased (E-selectin, p = 0.003) or found equal (CD144, p = 0.063), erythrocyte-derived MP were equal (p = 0.726), and GMP were increased (p = 0.008). GMP numbers correlated with plasma concentrations of elastase (r = 0.70, p = 0.036), but not with C-reactive-protein or interleukin-6 concentrations. Patient samples also contained reduced numbers of annexin V-negative PMP, and increased numbers of erythrocyte-derived MP and GMP (p = 0.005, p = 0.021 and p <0.001, respectively). Patient MP triggered thrombin formation, which was reduced compared to the healthy controls (p = 0.008) and strongly inhibited by an anti-factor XII MoAb (two patients), by anti-factor XI MoAb (eight patients) or by anti-TF MoAb (four patients). Concentrations of F1+2 and TAT were elevated (p = 0.005 and p = 0.001, respectively) and correlated inversely with the number of circulating MP (and r = -0.51, p = 0.013, and r = -0.65, p = 0.001, respectively) and their thrombin generation capacity (F1+2: r= -0.62, p = 0.013). CONCLUSIONS: In patients with MODS and sepsis relatively low numbers of MP are present that differ from controls in their cellular origin, numbers and coagulation activation mechanisms.

Acute-Phase Proteins↗

PubMed1994

Boys' and girls' perceptions of peers in middle childhood: differences and similarities.

Gender differences and similarities in children's person perception in middle childhood were studied. Free descriptions of a same-sex liked peer written by third to sixth grade boys (N = 254) and girls (N = 254) were studied from a cognitive-developmental perspective and with regard to content. Boys' and girls' descriptions did not differ in egocentrism, level of abstraction, or level of organization. Girls' descriptions, however, were cognitively more complex (i.e., more diverse in content). This might be related to girls' more intense dyadic forms of relationships with liked peers. Content analysis revealed that boys tend to focus on the peers themselves (content categories: achievements, preferences and aversions, personality characteristics) as distinct from their environment, whereas girls tend to perceive their liked peers as embedded in their contexts (background information, family, and kinship). This difference seems to reflect the more instrumental character of boys' relationships with peers and the more personalized character of girls' relationships.

Adolescent↗

PubMed1983