A potent tumor-regressing activity was found in the serum of mice with S180 tumor undergoing rapid regression caused by antitumor polysaccharides. Beta (1-3) glucan including CM-TAK and lentinan and ...mannoglucan MGA induced such activity. It causes a rapid decrease in the number of tumor cells accompanied with a marked increase in neutrophiles in solid tumors. The entity of the activity was named as tumor-regressing factor (TRF) and was partially purified revealing a proteinaceous nature with an approximate molecular weight of 250,000. The factor was induced in a serum of tumor-bearing mice in various host-tumor combinations after the tumor growth had been established but only weakly in normal mice. The sensitivity of tumors to the factor was also dependent on the stage of tumor growth. The serum of normal mice or tumor-bearing mice without polysaccharide treatment exhibited similar activity as TRF after definite chromatographic step. The chromatographic behavior of the revealed activity was closely similar to that of the induced factor. It was postulated that a TRF-like activity exists in normal serum in a inactivated form being bound by antagonist(s) and the appropriate chromatography might remove the antagonist resulting in the active form of the factor. The concept was confirmed by reconstituting the chromatographic fractions, the revealed activity was again obscured after mixing with a certain fraction.
The local application of lysophosphatidyl choline (LPC) by microinjection into the region of the corpus callosum of the rabbit produced demyelinating lesions. The lesions were assessed histologically ...using the Luxol fast blue myelin stain and the Holmes silver nitrate stain for the axis cylinders. Survival times for the animals ranged from 7 to 14 days. The center of the lesion was marked by infiltration of macrophages and necrosis, but the major area of the lesion was characterized by demyelination. By consideration of anatomical factors influencing LPC diffusion and of the appropriate placement of the injection, the entire vertical extent (about 0.5 mm) of the corpus callosum could be demyelinated with minimal amounts of necrosis. Since focal demyelination was possible in the fine caliber axons of the corpus callosum which are anatomically representative of many forebrain fiber systems, and since this fiber system is amenable to chronic physiological investigation, the corpus callosum may serve as an experimental model for morpho-physiological studies of mammalian central demyelinating pathways.
Two frog egg lectins Rana catesbeiana lectin (SBL-C) and Rana japonica lectin preferentially agglutinate a large variety of human and animal tumor cells but not blood cells, lymphocytes, or ...fibroblasts. These lectins belong to the superfamily of pyrimidine base-specific RNases. The two lectins bound to a heparin-Sepharose column and were eluted from the column by an increase of NaCl molarity. Both their tumor cell-agglutinating activity and RNase activity were inhibited by heparin, and also by polyamines, such as spermine. Both lectins inhibited P388 leukemia cell proliferation. The inhibitory activity of SBL-C was blocked by addition of heparin. SBL-C inhibited protein synthesis by P388 cells, but RNase A did not. No lectin-induced antiproliferative effect was observed after sialidase treatment of cells. The antiproliferative activity of SBL-C was also inhibited by ammonium chloride treatment. These results suggest that internalization of the lectins by lectin receptor (sialoglycoconjugate)-mediated endocytosis is followed by cell death due to inhibition of protein synthesis. Administration of SBL-C i.p. delayed time to death in mice receiving i.p. transplants of Sarcoma 180 and Mep II cells.
Goshajinkigan, a herbal medicine, has long been used in Japan to alleviate the subjective symptoms of diabetic neuropathy; however, its effects have not been confirmed objectively. We evaluated its ...effects on subjective symptoms and on vibration sensation in patients with diabetic neuropathy. The oral administration of 7.5 g/day of Goshajinkigan for 3 months (treatment period) relieved subjective symptoms of numbness in 9 of 13 patients. When the drug was discontinued for 2 months as a washout period, the subjective symptom worsened in 7 of 13 patients. Chi-square analysis revealed significant effects of Goshajiniagan on subjective symptoms (P < 0.001 for numbness and P < 0.05 for cold sensation). Vibration sensation was evaluated by measuring vibratory threshold using an SMV-5 vibrometer. There were significant changes in vibratory thresholds by paired t-test (P < 0.05) both in the upper and the lower extremities during the treatment and washout periods. Chi-square analysis also revealed a significant effect of Goshajinkigan on vibratory threshold (P < 0.01). There was no significant change in glycosylated hemoglobin as a whole during the study. These observations confirm that Goshajinkigan relieves subjective symptoms and demonstrate that it improves vibration sensation in patients with diabetic neuropathy.
Tachycitin is an invertebrate chitin-binding protein with an amidated C-terminus, and possesses antimicrobial activity against both fungi and bacteria. The 1H-NMR-based tertiary structure of ...tachycitin was recently determined Suetake et al. (2000) J. Biol. Chem., 275, 17929–17932. In order to examine the structural and functional features of tachycitin more closely, we performed for the first time, gene expression, refolding, 15N-NMR-based characterizations, and antimicrobial activity measurements of a recombinant tachycitin (rTcn) that does not have the amide group at the C-terminus. The NMR analysis indicated that rTcn possesses the same structural construction as the native tachycitin. The backbone 15N relaxation measurements showed that the molecular motional correlation time of rTcn increases as its concentration increases, indicating that tachycitins have a tendency to aggregate with each other. rTcn exhibits antimicrobial activity against fungi but not against bacteria. The cell surface of fungi contains chitin as an essential constituent, but that of bacteria does not. These results suggest that not only the chitin-binding region but also the C-terminal amide group of tachycitin plays a significant role in its antimicrobial properties.
The diagnostic accuracy of cardiac FDG imaging obtained with the dual-head coincidence gamma camera (DHC) is impaired by artifacts induced by nonuniform attenuation. This study proposed a new method ...(registration and segmentation method for attenuation correction AC-RS) to correct these attenuations in the chest region without the need for additional hardware or expensive transmission scanning equipment.
Before DHC imaging, 99mTc-tetrofosmin SPECT was performed using dual-energy acquisition from both the photopeak and Compton scatter windows. The scatter window images of the 99mTc-tetrofosmin were then registered 3-dimensionally with the cardiac DHC images and segmented into anatomic regions to obtain body and lung contours by applying the optimal threshold method on localized histograms. Theoretic attenuation coefficient values were assigned to the corresponding anatomic regions, and the DHC emission images were reconstructed using these attenuation correction factors. The results were quantitatively evaluated by imaging a cardiac phantom filled with a uniform solution and placed in a chest phantom. Eight nondiabetic subjects were also examined using this technique, and the results were compared with those of measured attenuation-corrected PET images.
Use of this technique in phantom and clinical studies decreased the degree of artifacts seen in the inferior wall activity and corrected the emission images. When the results were compared with those of PET scans, the regional relative counts of the uncorrected DHC scan did not correlate with the results of the PET scan. However, the regional relative counts of the AC-RS-corrected DHC scan exhibited a linear correlation with the results of the PET scan (r = 0.73; P < 0.001).
Reasonably accurate attenuation-corrected cardiac DHC images can be obtained using AC-RS without the need for transmission scanning.
We describe an online ADR (Alternative Disputation Resolution) System using a tool for generating facial expressions of animated agents. In this system, a participant of ADR disputes against an ...opponent through a computer network. The participant agent searches similar cases of arguments and supports the participant by showing the similar cases. The participant edits the next proposal by referring to the cases. And the agent learns the participant's tendency to select facial expressions, based on an emotional model, and generates the facial expression. The participant can reduce the cost of the dispute by using the participant agent.
Since the kidney is one of the major sites of action for atrial natriuretic peptide (ANP) and immunoreactive ANP has been detected in tissue extract by radioimmunoassay, we have applied the ...immunohistochemical technique by using the avidin-biotin complex method to investigate ANP binding sites in the rat kidney. Although no immunostaining was observed in the kidney of control rats, immunoreactive ANP was present in the juxtaglomerular cells, the vascular walls of interlobular arteries, arcuate arteries, arterioles including vas afferens and vas efferens, and the medullary peritubular capillary of ANP-pretreated rats. In contrast, no tubular structure was stained. These results suggest that ANP may affect renin secretion via its direct action on the juxtaglomerular cells and that it predominantly induces natriuresis by its effects on renal hemodynamics.
PDF
