Magnetic probe array with high sensitivity for fluctuating field.

A magnetic probe array is constructed to measure precisely the spatial structure of a small fluctuating field included in a strong confinement field that varies with time. To exclude the effect of the confinement field, the magnetic probes consisting of figure-eight-wound coils are prepared. The spatial structure of the fluctuating field is obtained from a Fourier analysis of the probe signal. It is found that the probe array is more sensitive to the fluctuating field with a high mode number than that with a low mode number. An experimental demonstration of the present method is attempted using a field-reversed configuration plasma, where the fluctuating field with 0.1% of the confinement field is successfully detected.

Enhanced transdermal delivery of phenylalanyl-glycine by chemical modification with various fatty acids.

We synthesized three novel lipophilic derivatives of phenylalanyl-glycine (Phe-Gly), C4-Phe-Gly, C6-Phe-Gly and C8-Phe-Gly by chemical modification with butyric acid (C4), caproic acid (C6) and octanoic acid (C8). The effect of the acylation on the stability, permeability and accumulation of Phe-Gly in the skin was investigated by in vitro studies. The stability of Phe-Gly in skin homogenates was low, but was significantly improved by the acylation. In the transport studies, a Franz-type diffusion cell was used for the permeability experiments with Phe-Gly and its acyl derivatives. The permeability of acyl-Phe-Gly derivatives across the intact skin was higher than that of native Phe-Gly. Of all the acyl-Phe-Gly derivatives, C6-Phe-Gly was the most permeable compounds across the intact skin. On the other hand, the permeability of acyl-Phe-Gly derivatives across stripped skin was less than that of native Phe-Gly in the initial time period of transport studies, but their permeability was higher than that of native Phe-Gly at the end of the transport studies. When the skin was pretreated with ethanol, which could inactivate the peptidases responsible for the degradation of Phe-Gly, the permeability of native Phe-Gly was higher than that of acyl derivatives. These findings indicated the involvement of peptidases on the permeability of Phe-Gly across the skin. The relationship between the lipophilic indexes of Phe-Gly derivatives and the permeability coefficients indicated that there is an optimal carbon number of fatty acid for improving the transdermal permeability of Phe-Gly by the acylation. A good correlation was found between the accumulation of these acyl-Phe-Gly derivatives in the intact skin and their lipophilicity. These results suggest that the stability and permeability of Phe-Gly were improved by chemical modification with fatty acids and this enhanced permeability of Phe-Gly by the acylation may be attributed to the protection of Phe-Gly from the enzymatic degradation in the skin and the increase in the partition of Phe-Gly to the stratum corneum.

Hematologic findings associated with thrombocytopenia during the acute phase of exanthem subitum confirmed by primary human herpesvirus-6 infection.

PURPOSE: To elucidate the mechanism underlying thrombocytopenia during the acute phase of exanthem subitum (ES), the associated hematological findings were investigated. PATIENTS AND METHODS: Five infants with thrombocytopenia during the acute phase of ES serologically confirmed by primary human herpesvirus-6 (HHV-6) were examined and followed-up. RESULTS: Thrombocytopenia was accompanied by neutropenia, leukopenia, and decreased reticulocyte fraction during the acute phase. These changes were self-limiting, and the sequential changes of platelet, neutrophil count, and reticulocyte fraction were closely linked. Slight but significant decreases in hemoglobin in the convalescent phase and mild increases in atypical lymphocytes after subsidence of the fever were observed. Hemophagocytosis and increase in atypical lymphocytes in the bone marrow suggested that bone marrow cells were influenced by primary HHV-6 infection. Platelet-associated immunoglobulin G and indirect antiplatelet antibody were negative. Plasma levels of fibrinogen and D-dimer of fibrinogen degradation products were within normal ranges. CONCLUSIONS: Thrombocytopenia is a complication of ES, and this may result from bone marrow suppression rather than from immune-mediated peripheral consumption seen in acute idiopathic thrombocytopenic purpura or from disseminated intravascular coagulation.