Platelet-activating factor in Japanese cedar pollinosis

Japanese cedar pollinosis is a typical allergic disease and has recently become a big social problem. Many population are suffering from this disease every year from the end of February to the beginning of April. In this study, we planned to examine the role of platelet-activating factor (PAF) in this disease, because PAF has been known to be one of the potent chemical mediators in allergic and inflammatory reactions and many evidences indicate that PAF is deeply involved in the pathogenesis of bronchial asthma, a typical allergic disease. We measured the concentrations of the PAF derivative (lyso-PAF) in serum from patients with cedar pollinosis during the pollen season. The level of lyso-PAF in serum from untreated patients with cedar pollinosis (87.8 +/- 8.7 unit.) was significantly higher than that in healthy control (54.9 +/- 7.7 unit.). We also tested the effect of an anti-allergic drug on the level of serum lyso-PAF of cedar pollinosis. Eighteen pairs of serum samples from patients with cedar pollinosis were employed in this study. Lyso-PAF levels after two weeks' therapy with ketotifen (2 mg/day), an anti-allergic drug, decreased the levels significantly (from 82.6 unit to 41.3 unit). These results suggest that PAF could play some important role in cedar pollinosis and that the clinical effect of anti-allergic drug could be partially due to the anti-PAF action.     

Platelet-activating factor in late asthmatic response

The role of platelet-activating factor (PAF) in the late asthmatic responses was studied. The concentrations of lyso-form of PAF in plasma were measured at 0 and 20 min, and 6 and 24 h after the antigen inhalation challenge among patients with bronchial asthma. PAF activities were measured by their aggregating ability of washed rabbit platelets after acetylation of lyso-PAF into the biological active form of PAF, when there were no detectable amounts of PAF in plasma. The concentrations of lyso-PAF were found to be significantly increased in patients with the late asthmatic response compared with patients with the single immediate response at 6 h after the antigen challenge. In contrast, lyso-PAF levels were not significantly different at 20 min after the antigen challenge between these two groups. PAF inactivator activity in plasma increased when there was a decrease in the lyso-PAF level. These results suggest that PAF may participate in the late asthmatic response and may provide a new insight into the pathogenesis and the treatment of bronchial asthma.     

Enhancing effects of oral adjuvants on anti-HBs responses induced by hepatitis B vaccine.

Hepatitis B (HB) vaccine is very promising for the prevention of HB infection. There exist, however, some non-responders to current vaccination trials. In this study, taurine, parotin and lithium were selected as adjuvants which can be administered orally. The mechanisms of these three materials as adjuvants and their effects on HB vaccine were investigated in mice. For instance, taurine induced polyclonal antibody production and exhibited adjuvant activity. Although taurine did not have any activity on the proliferation of thymocytes nor stimulate IL-2 production, taurine did induce IL-1 production by macrophages. It was considered that taurine-induced IL-1 would play an essential role in the proliferation and differentiation of B cells. Parotin also induced polyclonal antibody production and exhibited adjuvant activity. These effects of parotin were not affected even if macrophages or T cells were depleted, and parotin itself had an IL-1-like activity. Therefore, it was considered that parotin acted directly on B cells by its IL-1-like activity and mitogenic activity, resulting in the proliferation and differentiation of B cells. Lithium induced neither polyclonal antibody production, nor IL-1 or IL-2 production. However, when given with an antigen, lithium activated the humoral immune system, resulting in the augmentation of antibody production. Oral administration of taurine, parotin and lithium were capable of restoring antibody responses to HB surface antigen (HBsAg) in HBsAg-nonresponder mice. Furthermore, taurine, parotin and lithium enhanced the adjuvant effects of aluminium contained in the present HB vaccine. These observations indicate that use of these oral adjuvants may open new perspectives in the field of human HB vaccination.     

Influence of the parameters of several pulse sequences on the image contrast: comparison between the two major contrast media

We compared the influences of the parameters of several pulse sequences using two major commercially available gadolinium (Gd) contrast media for MR imaging. The phantom of Gd solutions of various concentration (0.1 - 10mmol/L) was prepared, and was scanned with a 1.5T clinical MR unit, using a spin-echo T1-weighted sequence, 2DFLASH, 3DFLASH, and 3DVIBE. The signal intensity was measured and the contrast enhancement ratio (CER) was calculated and plotted as a function of Gd concentration. The results were compared between the pulse sequences, and between the contrast media as well. Both 3DFLASH and 3DVIBE showed higher CER than other two sequences, showing similar CER curve configuration. There was no significant difference both in CER value and CER curve configuration between the two contrast media for each pulse sequence.     

Effects of thymol on the electrical and mechanical properties of the guinea-pig taenia coli

Effects of thymol (0.02-2 mM) on the electrical and mechanical activities of the smooth muscle cells of the guinea-pig taenia coli were investigated with either micro-electrode or double sucrose gap methods.1. Thymol, in a concentration of more than 0.03 mM, reduced the amplitude and maximum rate of rise of the spikes without any change of the membrane potential. When the concentration was increased to 0.3 mM, thymol completely blocked the spontaneous and evoked spike activities. In a concentration of more than 0.1 mM, thymol reduced the membrane resistance in proportion to the concentration without any change of the membrane potential.2. Ionic mechanisms involved in the effects of thymol on the membrane resistance were investigated in various ionic environments. The results showed that in concentrations below 0.5 mM thymol might selectively increase the Cl-conductance of the membrane. Participations of Na and K ion in the effects of thymol on the membrane resistance could be eliminated. However, at more than 1 mM, thymol increased the membrane conductance non-selectively. Excess Ca in the external solution partly suppressed the action of thymol on the taenia coli.3. Potentiation of the twitch tension was not observed on treatment with any concentration of thymol.4. After pre-treatment with thymol (0.5 mM), isotonic K Krebs solution depolarized the membrane and reduced the membrane resistance as observed in the absence of thymol. However, thymol completely suppressed the K-induced contracture.5. Application of excess Ca and acetylcholine during the maintained contracture evoked by isotonic K Krebs solution induced further development of the contracture. However, on pre-treatment with thymol, neither excess Ca nor acetylcholine could evoke a mechanical response in isotonic K Krebs solution.6. The results obtained from the present experiments are discussed in relation to the roles of Ca on the smooth muscle cells.     

Microradiography with an x-ray image magnifier: application to dental hard tissue

The superior spatial resolution obtained with parallel-beam microradiography over conventional contact microradiography has allowed us to image microstructural features of dental hard tissue not previously reported. Our efforts to extend these techniques to provide a real-time capability for viewing in situ demineralization and remineralization effects, at and below the 1-micron level, have resulted in an instrument with several novel and unique features. Using a synchrotron radiation source of x rays and diffraction image magnification, we are now able to change magnification at will (x-ray zoom lens). In addition, the energy range over which the instrument operates gives one considerable flexibility in optimizing image contrast. The techniques of parallel-beam microradiography, and diffraction image magnification are applicable to problems in many other areas of science. Using examples within dental research, the uniqueness and versatility of these new techniques are discussed.     

Electron-dense deposition patterns and the outcomes of idiopathic membranous nephropathy in Japanese

A considerable diversity in prognosis is seen with membranous nephropathy (MN). In terms of pathological findings, the presence of tubulointerstitial lesions was emphasized as a poor prognostic factor. However, the glomerular factors affecting the long-term outcome of idiopathic human MN have remained unclear. We reviewed the initial clinicopathological factors affecting the primary and secondary outcomes in 105 patients with primary MN, as well as reviewing previous reports. Based on electron microscopic (EM) findings, we could divide patients into two subtypes and one subgroup; i.e., homogeneous type with a synchronous phase of electron-dense deposits, with large dense deposits (deep subgroup) and heterogeneous type with various phases of dense deposits. The homogeneous type showed no endstage renal failure, and had earlier remission as compared with the heterogeneous type. For the secondary outcome, heterogeneous type and deep subgroup were also independent risk factors. However, there was no significant difference in the final primary or secondary outcome for any treatment subgroups. These results indicated that our category of EM findings was a beneficial marker of the primary and secondary outcomes in MN; the homogeneous type of MN with synchronous phase of electron-dense deposits (except for the "deep" subgroup) had a good outcome.     

Anaplastic Ependymoma of the Spinal Cord in Childhood A Case Report

We report a 6-year-old girl with anaplastic ependymoma probably originating in the region of the conus medullaris and probably spreading retrogradely to the region of the interventricular foramen (Monro) through the cere-brospinal fluid (CSF). Since ependymoma of the spinal cord rarely occurs in children, and retrograde spreading is extremely rare, the histological features and mechanism of metastasis of the tumor are discussed.