Evaluation of the effects of glucose and oxygen on the vascular endothelial cell migration.

Glucose is essential as the main energy source for living organisms. However, excessive elevation of blood sugar levels can lead to diabetes and serious complications such as arteriosclerosis. Even though blood sugar levels as well as hypoxia associated with hyperglycemia are known to be closely related to diabetes complications, the responses of vascular endothelial cells to glucose and oxygen have not been fully investigated. In this study, using a microfluidic device that can control the oxygen concentration, we observed the behavior of vascular endothelial cell monolayers while simultaneously controlling glucose and oxygen levels. Results showed that the cell migration speed was increased by high-glucose exposure in an oxygen-rich environment, but was decreased in a hypoxic environment regardless of glucose condition. The expression of vascular endothelial-cadherin at the cell periphery, which plays a role in cell-cell adhesion, was increased by hypoxic exposure, but was largely independent of glucose condition. This suggested that cell-cell adhesion is less involved in the increase in migration caused by high glucose. Furthermore, stabilization and nuclear translocation of hypoxia-inducible factor-1α, which is involved in cellular hypoxia sensing, increased 5 h after exposure to high glucose, but decreased 3 days after the exposure. This indicated that intracellular hypoxia was generated by increased oxygen consumption in mitochondria just after the high-glucose exposure, but it was moderated within 3 days.

Aerotaxis and aerokinesis of Dictyostelium discoideum under hypoxic microenvironments.

Although spatiotemporal changes of oxygen in a microenvironment are known to affect the cellular dynamics of various eukaryotes, the details are not fully understood. Here, we describe the aerotaxis and aerokinesis of Dictyostelium discoideum (Dd), which has long been employed as a model organism for eukaryotic cells. We developed a microfluidic device capable of time-lapse observation of cultured cells while controlling oxygen concentrations in microchannels. Migratory behaviors of Dd were observed and quantitatively evaluated under an oxygen concentration gradient from 0% to 21% O2, as well as in various uniform oxygen conditions. In a hypoxic region within the oxygen concentration gradient, Dd migrated toward regions of higher oxygen concentration at increased velocity, which was independent of cell density. Observed under uniform oxygen concentrations of 1%, 2%, 3%, and 21%, the migration velocity of Dd increased significantly in hypoxic environments of 2% O2 or less. Thus, Dd shows aerotaxis, directed by the oxygen concentration gradient, and simultaneously shows aerokinesis, changing the migration velocity according to the oxygen concentration itself.

The two-color analysis of the T-lymphocyte subsets in experimental allergic neuritis in rats.

We examined the T-cell subsets in the peripheral blood, spleen and lymph nodes during the course of experimental allergic neuritis (EAN) by using two-color analysis. In the acute phase, the percentages of CD4+ major histocompatibility complex (MHC)-II+ cells and CD8+ MHC-II+ cells in the lymph nodes of EAN rats were significantly higher than in the control rats. In the recovery phase, the percentage of CD4+ CD45RC+ cells and CD8+ CD45RC+ cells in the lymph nodes in EAN rats were significantly higher than in the control rats. However, significant changes of the T-cell subsets were not detected in either the spleen or the peripheral blood during the course of EAN. These results suggest that CD4+ MHC-II+ cells, CD8+ MHC-II+ cells, CD4+ CD45RC+ cells and CD8+ CD45RC+ cells may play a role in the course of EAN. The relationship between these double staining cells and EAN is discussed.

Reduced natural killer cell activity in patients with dementia of the Alzheimer type.

We examined the natural killer (NK) cell activity in 50 patients with dementia of the Alzheimer type (DAT) and 37 age-matched normal controls. The NK cell activity in DAT was significantly lower than in the normal controls. The NK cell activity induced by either interferon-alpha (IFN-alpha) or interleukin-2 (IL-2) in DAT was also significantly lower than in the normal controls. There were no significant differences in the level of serum IL-2 and IFN-alpha between the two groups. As regards NK cell subsets, two-color flow cytometric analysis showed no significant differences between the percentages of Leu-11+ Leu-7- cells, Leu-11+ Leu-7+ cells and Leu-11- Leu-7+ cells in the two groups. Our results suggest that NK cells in DAT may have functional abnormalities and may provide important clues to fundamental cellular and molecular aberrations in DAT.

Kappa/lambda ratios of IgG, IgA and IgM in the cerebrospinal fluid of patients with Guillain-Barré syndrome.

The kappa/lambda (kappa/lambda) ratios of IgG, IgA and IgM in the cerebrospinal fluid (CSF) and in the sera of 10 patients with Guillain-Barré syndrome were analyzed. The kappa/lambda ratios of IgG, IgA and IgM in the CSF and in the serum were not significantly different between the acute and the late stages of Guillain-Barré syndrome nor between Guillain-Barré syndrome and the normal controls. In the CSF, however, the concentration of albumin, IgG, IgA and IgM in the acute phases of Guillain-Barré syndrome were significantly higher than in the normal controls. These results suggest that in Guillain-Barré syndrome, the increase of immunoglobulins may not be due to intrathecal synthesis and therefore there are no significant changes in the kappa/lambda ratios in the CSF.

Lymphocyte proliferation and subpopulations in dementia of the Alzheimer type.

Lymphocyte proliferation in dementia of the Alzheimer type (DAT) was evaluated by the level of mitogen response using phytohemagglutinin, pokeweed mitogen, concanavalin A and staphylococcal protein A. Lymphocyte subpopulations in the peripheral blood were also investigated using a monoclonal antibody with a fluorescence-activated cell sorter. The mitogen response in DAT was not significantly different from that in the normal controls. Lymphocyte subpopulations (Pan T, helper T, suppressor T, B cell, HLA-DR positive cell and helper/suppressor ratio) in DAT were not significantly different from those in the normal controls. These results suggest that the lymphocyte proliferative response to mitogens and the subpopulations in DAT may be natural in the normal aging process.

Peripheral nerve involvement in HTLV-I-associated myelopathy: report of a case.

A patient came to our clinic suffering from mild sensory loss, exaggeration in knee reflexes, bilateral extensor plantar responses and elevation of the antibody level to the human T-lymphotropic virus type I (HTLV-I). Electrophysiological and pathological studies showed axonal and demyelinating neuropathy. The condition appeared to be a slowly progressive myeloneuropathy. HTLV-I may play an important role in the pathogenesis of myeloneuropathy.

Kappa/lambda ratios in IgG, IgA and IgM of cerebrospinal fluid and of sera in patients with multiple sclerosis.

Kappa/lambda (kappa/lambda) ratios of each immunoglobulin, i.e. IgG, IgA and IgM in cerebrospinal fluid (CSF) and in sera of patients with multiple sclerosis (MS) were analysed by sandwich enzyme linked immunosorbent assay. In CSF kappa/lambda ratios of IgG of MS patients were significantly (p less than 0.05) higher than those of normal controls, whereas the values of IgA and IgM did not differ significantly from those of normal controls. In sera kappa/lambda ratios of IgG, IgA and IgM did not differ significantly from those of normal controls. Our results suggest that in MS patients abnormal kappa/lambda ratios are also restricted to IgG components in CSF, as oligoclonal IgG bands are.