Jun'ichi Tamura

Inflammatory cytokines in vitreous fluid and serum of patients with diabetic vitreoretinopathy

To determine whether inflammatory cytokines are increased in proliferative diabetic retinopathy. We measured concentrations of interleukin-6, 8 (IL-6, 8) and tumor necrosis factor (TNF)-alpha by enzyme-linked immunosorbent assay (ELISA) in vitreous and serum from 47 patients with proliferative diabetic retinopathy and 21 patients with vitreous noninflammatory retinopathies. Vitreous concentration of IL-6 were 64.7+/-12.8 pg/ml in proliferative diabetic retinopathy, much greater (P<.005) than in noninflammatory retinopathy (2.8+/-4.5 pg/ml). Amounts of IL-8 in vitreous fluid also were greater in proliferative retinopathy than in noninflammatory retinopathy (34.0+/-11.5 vs. 6.1+/-2.0 pg/ml, P<.005). Concentrations of TNF-alpha in vitreous fluid were not statistically different in proliferative retinopathy from those in noninflammatory retinopathy. In sera, concentrations of IL-6 and IL-8 were not different between proliferative and noninflammatory retinopathy. However, serum TNF-alpha was much greater in proliferative retinopathy than in noninflammatory retinopathy (0.81+/-0.72 vs. 0.09+/-0.00 pg/ml, P<.001). Elevated TNF-alpha in serum then may be diagnostically useful in proliferative diabetic retinopathy. And inflammatory cytokines in vitreous may be pathogenically important in this concentration.

Immunomodulation by vitamin B12 : Augmentation of CD8+ T lymphocytes and natural killer (NK) cell activity in vitamin B12-deficient patients by methyl-B12 treatment

It has been suggested that vitamin B12 (vit.B12) plays an important role in immune system regulation, but the details are still obscure. In order to examine the action of vit.B12 on cells of the human immune system, lymphocyte subpopulations and NK cell activity were evaluated in 11 patients with vit.B12 deficiency anaemia and in 13 control subjects. Decreases in the number of lymphocytes and CD8+ cells and in the proportion of CD4+ cells, an abnormally high CD4/CD8 ratio, and suppressed NK cell activity were noted in patients compared with control subjects. In all 11 patients and eight control subjects, these immune parameters were evaluated before and after methyl‐B12 injection. The lymphocyte counts and number of CD8+ cells increased both in patients and in control subjects. The high CD4/CD8 ratio and suppressed NK cell activity were improved by methyl‐B12 treatment. Augmentation of CD3−CD16+ cells occurred in patients after methyl‐B12 treatment. In contrast, antibody‐dependent cell‐mediated cytotoxicity (ADCC) activity, lectin‐stimulated lymphocyte blast formation, and serum levels of immunoglobulins were not changed by methyl‐B12 treatment. These results indicate that vit.B12 might play an important role in cellular immunity, especially relativing to CD8+ cells and the NK cell system, which suggests effects on cytotoxic cells. We conclude that vit.B12 acts as an immunomodulator for cellular immunity.

Zn deficiency aggravates hypertension in spontaneously hypertensive rats: Possible role of Cu/Zn-superoxide dismutase

Using spontaneously hypertensive rats (SHR) fed a standard or a Zn-deficient diet for 4 weeks, we examined whether Zn deficiency affects systemic blood pressure (BP) levels in a genetically hypertensive state through a fall in the activity of Cu/Zn-superoxide dismutase (SOD). SHR fed a Zn-deficient diet had a progressive increase in systolic BP during the dietary conditioning. Consequently, SHR fed a Zn-deficient diet exhibited significantly increased levels of systolic BP by 2 weeks after the start of dietary treatment when compared with SHR fed a standard diet. Similarly, levels of basal mean arterial pressure (MAP) observed at the end of dietary treatment were SHR fed a Zn-deficient diet>SHR fed a standard diet. Administration of the nitric oxide synthase (NOS) inhibitor, L-NAME, caused an increase in MAP levels in the two groups of rats, demonstrating the involvement of the vasodilator, nitric oxide (NO), in the regulation of systemic BP in a genetically hypertensive state. The expression of endothelial (e) NOS mRNA and protein in the thoracic aorta paralleled basal MAP levels in the two groups of rats, suggesting the counter-regulation of eNOS against the developed hypertensive state in SHR fed a Zn-deficient diet. On the other hand, administration of the superoxide scavenger, tempol (a SOD mimetic compound), led to a decrease in MAP levels in the two groups of rats, indicating the participation of the oxygen free radical, superoxide, in an increase in systemic BP in a genetically hypertensive state. As reported recently, the mechanism involved is due likely to a decrease in the action of the vasodilator, NO, based on the formation of peroxynitrite coming from the non-enzymatic reaction of superoxide and NO. In addition, tempol treatment completely restored MAP levels in SHR fed a Zn-deficient diet to levels comparable to those observed in SHR fed a standard diet, indicating that a further increase in systemic BP levels seen in SHR fed a Zn-deficient vs. a standard diet is presumably brought by a reduction in the action of the vasodilator, NO, resulting from an increase in the action of superoxide. The activity of the superoxide scavenger, Cu/Zn-SOD, in the thoracic aorta was significantly decreased in SHR fed a Zn-deficient diet relative to SHR fed a standard diet. It appears that a decrease in the activity of Cu/Zn-SOD observed in the thoracic aorta of SHR fed a Zn-deficient diet at least in part plays a role in an increase in the action of superoxide in this model. Thus, Zn deficiency may be a factor to develop genetic hypertension presumably through the oxidative stress caused by superoxide.

Plasmodium berghei: isolation and maintenance of an irradiation attenuated strain in the nude mouse.

Abstract An attenuated strain of malaria causing limited parasitemia in mice was derived from a highly virulent strain of Plasmodium berghei (NK65) which produced 100% lethality in mice. A pool of mouse blood infected with the original highly virulent P. berghei was exposed to 40 Krad irradiation and parasites were inoculated into nude mice as well as into thymus competent normal littermates. Thymus competent mice showed no parasitemia, while one out of the five nude mice inoculated with the irradiated parasites developed a slow and progressive parasitemia. These parasites induced a self-limiting parasitemia in thymus competent mice, even when a large inoculum was administered. Maintenance of the low virulence strain required passage through nude mice. After 50 passages at two weekly intervals, reversion to virulence did not occur. A single vaccination with the attenuated strain induced immunity in mice against a challenge inoculation with the original virulent strain. Specific IgG persisted at high titer for more than 9 weeks in mice receiving a single inoculation of the attenuated strain.

Circulating interleukin-6 and interleukin-6 receptors in patients with acute and recent myocardial infarction.

Interleukin-6 (IL-6), a proinflammatory cytokine, plays a key role in the pathogenesis of coronary artery disease (CAD). We investigated circulating IL-6 and its receptors in patients with CAD. We evaluated 39 Japanese patients with CAD (30 males and 9 females aged 36–79 years), measuring their plasma levels of IL-6 and IL-6 receptors α and β (IL-6Rα, IL-6Rβ). Circulating levels of IL-6, IL-6Rα and IL-6Rβ were measured by an enzyme-linked immunosorbent assay. Blood was sampled immediately after admission and again after 1, 2, 3, 6 and 9 h, then every 12 h for 5 days. Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) were measured on day 3 after symptom onset. Plasma levels of IL-6 and IL-6Rs were significantly increased in 28 patients with acute myocardial infarction (AMI) compared with 15 normal controls. However, neither IL-6 nor IL-6Rs showed an increase in 6 patients with angina pectoris. We observed two peaks for circulating IL-6 in AMI, the first of which showed a significant correlation with ANP as well as BNP. These results may help to explain why the amount of IL-6 produced is closely related to the severity of myocardial dysfunction in patients with CAD.

Immunological abnormalities in splenic marginal zone cell lymphoma

The clinical features of patients with splenic marginal zone cell lymphoma (SMZCL) have rarely been reported. In the present study, immunological abnormalities, particularly hematological abnormalities, observed in SMZCL were described. Autoimmune hemolytic anemia, immune thrombocytopenia, and appearance of lupus anticoagulant were observed in 2 of 3 patients with SMZCL. Other abnormal data including monoclonal gammopathy and cold agglutinin were also observed in 2 of the 3 patients. Immunological abnormalities may be characteristic complications in patients with SMZCL and must be followed carefully, since they may be a reliable marker of this type of lymphoma activity. Am. J. Hematol. 56:173–178, 1997.

A transient rise in plasma β-endorphin after a traditional 47°C hot-spring bath in Kusatsu-spa, Japan

Abstract To clarify the mechanism of the intoxicating feeling attained after a traditional 47°C hot-spring bath called ‘jikan-yu’ in Kusatsu-spa, Japan, we examined the change in plasma levels of β-endorphin and methionine enkephalin in 7 healthy subjects. The mean sublingual temperature rose from 36.8°C to 38.6°C and the plasma β-endorphin level from 16.2 pg/ml to 49.5 pg/ml 2 minutes after completing a 3-minute bath in 47°C hot-spring water. However, the plasma methionine enkephalin level was not changed. This feeling of intoxication may be explained by the transient rise in plasma β-endorphin level.

Ligand-induced downregulation of TrkA is partly regulated through ubiquitination by Cbl

c‐Cbl physically interacts with TrkA by anti bait coimmunoprecipitation (View interaction)

Improvement of extrathymic T cell type of large granular lymphocyte (LGL) leukemia by cyclosporin A: the serum level of Fas ligand is a marker of LGL leukemia activity

Abstract: We report a case of γδ T‐cell‐type large granular lymphocyte (LGL) leukemia (CD3+,CD8+, CD57+,TCR γδ+), which was accompanied by pure red cell aplasia, neutropenia and thrombocytosis. Southern blotting analysis of the T‐cell receptor β gene showed the germline configuration, but clonal TCR J γ rearrangements were identified. These granular lymphocytes demonstrated non‐major histocompatibility complex‐restricted cytotoxicitity. The serum‐soluble FasL (sFasL) concentration of this patient was very high, whereas the serum levels of tumor necrosis factor alpha (TNF‐α), interferon gamma (IFN‐γ), interleukin‐1 beta (IL‐1β), interleukin‐2 (IL‐2) and thrombopoietin were normal. After treatment with cyclosporin A, anemia and thrombocytosis were improved, and LGL and the elevated sFasL concentration decreased. These observations suggested that FasL may have played a role in the establishment of the clinical symptoms of this patient and could be useful as an indicator of disease activity.

The behaviour of red cells in narrow tubes in vitro as a model of the microcirculation

To investigate the behaviour of red cells in the microcirculation, we established a new capillary method using narrow fluorinated ethylenepropylene copolymer tubes with internal diameters of 12.5 and 25.0 μm. Red cell flow in the tubes under a given range of pressure was analysed through a video system connected to a microscope. The experimental condition was adjusted so that the velocity of the control normocytes would be compatible with that in corresponding vessels in vivo, 0.5–1.5 mm/s. In the 12.5 μm tube, normocytes obtained from 12 young normal volunteers ran in an axisymmetric edge‐on orientation with a folded shape at higher pressures, but rolled along freely without deformation at lower pressures. Deformation during the passage of the microcytes obtained from four patients with polycythaemia vera complicated with iron‐deficient microcytosis and 10 patients with iron deficiency anaemia was relatively mild, whereas that of the macrocytes obtained from eight patients with refractory anaemia was marked. Even after the screening effect at the tube entrance was taken into consideration, the velocities of both microcytes and macrocytes were found to be significantly lower than the control normocytes. Therefore this method may be a new way to investigate the flow properties of red cells in the microcirculation.