Antitumor immune response by CX3CL1 fractalkine gene transfer depends on both NK and T cells

The CX3C chemokine fractalkine (CX3CL1) exists as both a membrane-bound form promoting firm cell-cell adhesion and a soluble form chemoattracting leukocytes expressing its receptor CX3CR1. When adenoviral vector expressing mouse fractalkine (AdFKN) was transduced to the tumor cells, fractalkine was expressed as both membrane-bound form on the tumor cells and soluble form in the supernatant in vitro. Intratumoral injection of AdFKN (1 x 10(9)PFU/tumor) into C26 and B16F10 tumors resulted in marked reduction of tumor growth compared to control (C26: 86.5%, p<0.001; B16F10: 85.5%, p<0.001). Histological examination of tumor tissues revealed abundant infiltration of NK cells, dendritic cells, and CD8(+) T lymphocytes 3 and/or 6 days after treatment with AdFKN. Splenocytes from mice treated by AdFKN developed tumor-specific cytotoxic T cells, and thereby protected from rechallenging with parental tumor cells. Antitumor effects by AdFKN were completely abrogated in both NK cell-depleted mice and CD8(-/-) mice, and partially blocked in CD4(-/-) mice. These data indicated that fractalkine mediates antitumor effects by both NK cell-dependent and T cell-dependent mechanisms. This study suggests that fractalkine can be a suitable candidate for immunogene therapy of cancer because fractalkine induces both innate and adaptive immunity.     

Critical spectral regions for vowel identification

The first two formant frequencies (F1 and F2) are the cues important for vowel identification. In the categorization of the naturally spoken vowels, however, there are overlaps among the vowels in the F1 and F2 plane. The fundamental frequency (F0), the third formant frequency (F3) and the spectral envelope have been proposed as additional cues. In the present study, to investigate the spectral regions essential for the vowel identification, untrained subjects performed the forced-choice identification task in response to Japanese isolated vowels (/a, o, u, e, i/), in which some spectral regions were deleted. Minimum spectral regions needed for correct vowel identification were the two regions including F1 and F2 (the first and fourth in the quadrisected F1-F2 regions in Bark scale). This was true even when phonetically different vowels had a similar combination of F1 and F2 frequency components. F0 and F3 cues were not necessarily needed. It is concluded that the relative importance in the spectral region is not equivalent, but weighted on the two critical spectral regions. The auditory system may identify the vowels by analyzing the information of the spectral shapes and the formant frequencies (F1 and F2) in these critical spectral regions.     

Novel immunosuppressive effect of FK506 by augmentation of T cell apoptosis

We have recently reported the accumulation of oligoclonal activated T cells in the spontaneously developed autoimmune pancreatitis in aly/aly mouse. In this study, we examined the effects of FK506 in this mouse model in preventing autoimmune pancreatitis and investigated its action on calcium signalling apoptosis of alymphoplasia (aly) lymphocytes in vitro. Mice were treated with FK506 from 8 to 25 weeks of age. At the age of 15 weeks, minimal mononuclear cell infiltration was observed in the pancreas in both the FK506 treated group and the control group. Furthermore, a marked cell infiltration associated with destruction of acini and partial fatty changes were observed in 25-week-old control mice. In contrast, FK506 treated mice showed almost no tissue destruction or mononuclear cell infiltration at the age of 25 weeks. Furthermore, at 15 weeks of age, most mononuclear cells in FK506-treated mice were TUNEL positive, whereas only a few were positive in control mice. This augmentation of T cell apoptosis by FK506 was confirmed using naive splenocytes activated by PMA and ionomycin in vitro. Finally, a suppressive effect of FK506 on Bcl-2 production but not on Bax production was confirmed by Western blotting. This unique effect of FK506 on the augmentation of T cell apoptosis is probably one of the mechanisms explaining its beneficial effect on aly autoimmune pancreatitis.     

Immunocytochemical characteristics of human osteosarcoma cell line HS-Os-1: possible implication in apoptotic resistance against irradiation

In our previous study, we examined reactive oxygen species (ROS) formation in T lymphocytes following 5 Gy irradiation. We found that ROS formation occurred immediately after irradiation, continued for several hours, and resulted in oxidative DNA damage. Therefore, the origin of the hyper-radiosensitivity of T lymphocytes seemed to be the high production of ROS in the mitochondrial DNA following irradiation. In the succeeding study, we examined radiation-induced ROS formation, oxidative DNA damage, early apoptotic changes, and mitochondrial membrane dysfunction in the human osteosarcoma cell line HS-Os-1. We found that ROS formation and oxidative DNA damage were actually scarcely seen after irradiation of up to 30 Gy in these cells, that mitochondrial membrane potential was preserved, and that apoptotic changes were not demonstrated despite the relatively high-dose irradiation of 30 Gy. In the present study, we examined the immunocytochemical characteristics of the apoptotic-resistance of the HS-Os-1 cell line against irradiation in order to clarify its possible implications regarding radiosensitivity. The results showed that these cells lack P53 and Bax protein expression, and strong peroxidase activity was confirmed in the nuclei of the cells. Moreover, SODII (manganese superoxide dismutase II) protein expression was gradually increased in spite of irradiation of up to 30 Gy. Therefore, it is concluded that HS-Os-1 cells are originally apoptotic-resistant and that the cells possess a strong ability to scavenge for free radicals. To convert these cells to a state of apoptotic-susceptibility, a powerful oxidant such as hydrogen peroxide might exert such an effect in terms of the production of hydroxyl radicals in lysosomes in the cells as shown in our previous studies. The origin of the radioresistance of the human osteosarcoma cell line HS-Os-1 is considered to to be low degree of ROS formation following irradiation, reflecting the strong scavenging ability of these cells for free radicals including hydroxyl radicals.     

Silicon contents in normal, fatty streaks and atheroma of human aortic intima: its relationship with glycosaminoglycans

The silicon (Si) content and glycosaminoglycans (GAG) of normal, fatty streaks and atheroma of human aortic intima was measured. The Si content in fatty streaks and/or atheroma was significantly higher than in normal human aortic intima (P less than 0.05). The GAG content in human aortic intima was inversely correlated with the severity of atherosclerosis as described in many reports. However, the percentage composition of dermatan sulphate (DS) in total GAG was found to increase with the advance of atherosclerosis, and was significantly higher than that in normal and fatty streaks (P less than 0.001, P less than 0.01, respectively). In human aortic intima, a significant negative correlation was seen between Si content and the content of each GAG except GlcUA-GalNAc-6-sulphate (CS-6-S), and a significant positive correlation was noted between Si content and the content of each lipid. Interestingly, the percentage composition of DS in total GAG showed a significant positive correlation with Si content in human aortic intima (r = 0.603, P less than 0.005). These results suggest the increase in Si in the aortic intima is related to the occurrences and/or progression of atherosclerosis, whether primary or secondary.     

A role of fibrinolytic activity in angiogenesis. Quantitative assay using in vitro method

The functional role of the fibrinolytic system in capillary growth was investigated using bovine capillary endothelial cells (BCEs) cultured on a Type I collagen gel matrix, into which the cells migrated to form capillary-like tubular structures. The length of the tubes formed were measured morphometrically using an image analyzer in the absence and presence of fibrinolytic proteases, namely plasminogen, plasminogen activators (PAs) and PA inhibitor (PAI). The addition of plasminogen (25 micrograms/ml) to the gel matrix significantly increased the length of BCE tubes found on the 9th day of culture (p less than 0.01), with a dose-dependent tendency. The simultaneous addition of a basic fibroblast growth factor (bFGF, 10 ng/ml) enhanced this tube formation as early as the 3rd day of culture (p less than 0.01). Cultured BCEs secreted both tissue-type and urokinase-type PAs (tPA and uPA) and PAI-1 into the culture medium, and the secretion of both PAs was enhanced by the addition of bFGF. However, the secreted tPA was composed mostly of an inactive form of tPA.PAI-1 complex, and the PA activity was derived mostly from uPA. Inhibitors of plasmin suppressed the enhancing effect of plasminogen on angiogenesis. In addition, anti-uPA IgG markedly inhibited the enhancing effect of plasminogen on the 4th and 7th days of culture (p less than 0.01), whereas anti-tPA IgG showed an inhibitory tendency only on the 4th day of culture (p less than 0.05). These findings indicate that the plasminogen-PAs system, especially uPA synthesized and secreted by BCEs, plays an important role in regulating angiogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Needle tract implantation of thymoma after transthoracic needle biopsy.

A 73 year old woman was admitted to hospital because of an anterior mediastinal mass. For definite diagnosis, needle biopsy was performed under fluoroscopic observation. The histopathological diagnosis was thymoma and combination chemotherapy was given. The tumour almost completely disappeared and the patient was discharged. But the tumour recurred in the left anterior chest wall four months later. It is suggested that the thymoma tissue had been implanted in the needle tract.     

Relationships between muscle lactate accumulation and surface EMG activities during isokinetic contractions in man

Summary In order to investigate the relationship between metabolic state and myoelectrical activity in working muscle during short term intense exercise, eleven healthy males performed isokinetic knee extensions at an angular velocity of 180 deg · sec^–1 for 30 and 60 s. The median frequency (MF) of the surface electromyogram (EMG) recorded from vastus lateralis was decreased while the time lag of torque production after the onset of electrical activity (EMD) was increased during exercise. These changes (MF and EMD) corresponded well to muscle lactate accumulation in the same muscle. Over the exercise period, the integrated EMG/knee extension peak torque ratio (E/T ratio) was increased, which indicated a decrease in the efficiency of electrical activity. It was concluded that the changes in the frequency components of the EMG and in the contractile property of the muscle during short term intense exercise correlated with lactate accumulation in the identical muscle, and that the decrease in efficiency of the electrical activity in the muscle suggested peripheral fatigue.     

Isoelectric focusing spectra of anti-bacterial alpha-amylase antibody unique for antigen-induced suppression.

The effect of intravenous (i.v.) administration of bacterial alpha-amylase (B alpha A) on the IgG antibody response to a subsequent challenge with B alpha A in incomplete Freund's adjuvant (IFA) varied with the difference in responsiveness of the parental strains. High-responder C3H/He (C3) mice given injections of either 200 or 4 micrograms of B alpha A, which alone were unable to trigger a detectable IgG antibody response, generated an enhanced response to an immunogenic challenge given 25 days after the last i.v. injection. The response of low-responder C57BL/6 (B6) mice previously exposed to B alpha A, following a different kinetic course depending on the exposing dose, reached a plateau lower than the levels of control responses (tentatively designated as high- and low-zone suppression). Prior exposure of (B6 X C3)F1 hybrids to 200 micrograms led to the enhanced response, whereas pretreatment with 4 micrograms rendered them partially tolerant to a subsequent challenge. These results suggest that the capacity to achieve low-zone suppression is inherited as a dominant trait. Isoelectric focusing (IEF) analysis revealed that these enhanced responses expanded antibody heterogeneity in a strictly restricted, strain-specific manner as observed during the normal antibody response, although the rate of expansion was accelerated. The specific antibodies produced by individual high-zone suppressed B6 mice were focused as a limited set of bands in a narrow pH range where the specific antibodies produced early in the normal response were focused. In contrast, the response of low-zone suppressed B6 and F1 hybrid mice was characterized by a unique process of heterogeneity expansion.