Serum levels of thrombopoietin, IL-11, and IL-6 in pediatric thrombocytopenias.

We measured serum levels of thrombopoietin (TPO), interleukin (IL)-11, and IL-6 in 90 different samples from 67 pediatric patients with thrombocytopenia (TP). The cytokine levels were determined by enzyme-linked immunosorbent assays (ELISA), and the biological activity of TPO was measured using a cell line transfected with human c-mpl. In patients with impaired megakaryocytopoiesis, as found in diseases such as aplastic anemia, amegakaryocytic TP, or TP with absent radii, we found TPO levels which were highly elevated compared with normal values (mean=261 AU/ml, n=52, vs. 22 AU/ml in healthy controls). In contrast, patients suffering from idiopathic thrombocytopenic purpura (mean=16 AU/ml, n=31) or platelet function defects (mean=23 AU/ml, n=7) demonstrated normal TPO levels. The biological activity tested in the bioassay correlated well with the ELISA data. However, sera of some patients with amegakaryocytic TP demonstrated a remarkably higher biological activity of TPO than expected from the ELISA data. Within the different groups there was no correlation between platelet counts and TPO levels. Only 27% of all samples had elevated levels of IL-11 (mean=450 pg/ml, n=20). Elevated IL-6 serum levels were detected in only 13% of all samples analyzed (mean=42 pg/ml, n=12). We conclude that megakaryocytopoiesis is regulated mainly by TPO, that it is dependent on the platelet and the megakaryocytic mass, and that IL-11 plays an additional role in supporting the platelet production. IL-6 does not appear to be up-regulated in children with thrombocytopenia.

Evaluation of five devices for self-monitoring of blood glucose in the normoglycaemic range.

Although hypoglycaemia is a serious risk of intensive insulin therapy, studies on the accuracy of devices for self-monitoring of blood glucose (SMBG) include only a few values below 100 mg/dl. This study evaluated five SMBG devices in the normal range of blood glucose. In three separate series, capillary blood was taken from 207, 214 and 49 healthy subjects and was analysed with the SMBG devices and a laboratory method. Mean (+/- standard deviation) blood glucose values were 86+/-13 mg/dl, 83+/-12 mg/dl and 90+/-16 in series 1-3. All measurements with SMBG devices differed significantly from the laboratory method. The relative deviation from the laboratory method was 5.5% (2.4-10.5%, median and interquartile range) for Accutrend, 7.1% (3.6-12.6%) for Precision QID, 7.5% (3.7-13.7%) for Accu-Chek III, 14.1% (6.2-22.2%) for Companion 2 and 15.2% (10.3-21.3%) for One Touch II (p < 0.05). In conclusion, this study shows important differences in the accuracy of five SMBG devices in the normoglycaemic range. Accutrend and--to a lesser degree--Accu-Chek III and Precision QID obtained better results and can be recommended for SMBG in patients treated with intensive insulin therapy.

Cryptobia salmositica: susceptibility of infected rainbow trout, Salmo gairdneri, to environmental hypoxia.

Using the sealed jar technique (also called residual oxygen bioassay), rainbow trout fry infected with Cryptobia salmositica were more susceptible than non-infected fish to environmental hypoxia. The Winkler technique (azide modification) was used to determine the residual dissolved oxygen in the water. Susceptibility of infected fish increased with 1) time after infection and was most evident in 3-7 wk infections, 2) the severity of anemia, and 3) increasing parasitemia. In prolonged infections, susceptibility was reduced when there were decreases in anemia and parasitemia; however, these infected fish were still more susceptible than non-infected fish. The increase in susceptibility of infected fish to hypoxia may be an important contributing factor to mortality of fish in hatcheries where there is inadequate water flow and overcrowding. The sealed jar technique is recommended in future studies on the pathogenesis of parasitic fish diseases, especially if the metabolic and/or respiratory systems are affected by the infection.

In vivo and in vitro studies on the host specificity of Trypanoplasma salmositica.

The host specificity of Trypanoplasma salmositica was studied by experimental inoculation into 13 species of common teleosts (Notropis cornutus, Notropis heterolepis, Notropis spiloperus, Nocomis biguttatus, Rhinichthys atratulus, Semotilus atromaculatus, Carassius auratus, Ambloplites rupestris, Lepomis gibbosus, Etheostoma nigrum, Hypentelium nigricans, Ictalurus melas, and Eucalia inconstans). T. salmositica was not recovered at 14 and 40 days post inoculation. However, large numbers of the parasite were recovered from Salmo gairdneri and Cottus cognatus, thus indicating that sculpins might be reservoir hosts in certain areas where salmonids and sculpins occur in close proximity. Using a modified In Vitro Plasma Incubation Technique, it was shown that the plasma of refractory fishes had lytic ability and the titer ranged from 1:4 to 1:8. Undiluted fresh plasma of goldfish and of the northern hog sucker lysed about 500 parasites within 30 to 60 mins at 4 C. This lytic ability of fresh plasma was heat labile and partial coagulation of the blood also reduced the lytic titer. This study showed that Trypanoplasma salmositica was more host specific than orginally reported. It was suggested that the mechanism responsible for providing the innate immunity to this parasite in some fishes was the Alternate Pathway of Complement Activation.