Changes in the P100 latency of the visual evoked potential and the saccadic reaction time during isometric contraction of the shoulder girdle elevators

We investigated changes in the P100 latency of the visual evoked potential (VEP) and the saccadic reaction time (SRT) in relation to the degree of activity of the shoulder girdle elevators. Muscle force was set in 10% increments from 0% to 50% of the maximal voluntary contraction (MVC). The VEP was derived from a midline occipital electrode with reference electrodes on the ears when the right retina was stimulated through the eyelid by light emitting diodes while the eyes were closed. The P100 latency of the VEP was defined as the time from the stimulus onset to the main positive peak. The SRT was defined as the latency until the beginning of eye movement toward the lateral target, which was moved at random time-intervals. P100 latency was shortened until 30% of the MVC, and which it lengthened. The SRT changed in a pattern similar to that observed for the P100 latency. The ratio of the shortening in P100 latency relative to that of the SRT was approximately 20%. All data is presented as the mean value, plus the standard deviation. We believe that the information processing time in the neural pathway from the retina to the visual cortex was shortened up to a certain muscle force of the shoulder girdle elevators, and then this processing time lengthened. These findings indicate that shortening of information processing time in the neural pathway beyond the visual cortex is included in the shortening of the SRT.     

Expression of matrix Gla protein and osteonectin mRNA by human aortic smooth muscle cells.

BACKGROUND: Recent data indicate that matrix proteins such as matrix Gla protein (MGP) and osteonectin (ON) influence not only mineralization of vasculature but smooth muscle cell (SMC) differentiation. METHODS: We examined whether MGP and ON are expressed by human aortic SMCs in vivo using Northern blotting, in situ hybridization and immunohistochemistry. RESULTS: MGP and ON mRNAs were strongly expressed in the aorta without atherosclerosis from newborn and four young subjects up to 10 years old. In the aorta from 15 adult cases, MGP and ON mRNAs were decreased as atherosclerosis developed. We determined cell type and distribution of the MGP- and ON mRNA-expressing cells by in situ hybridization and immunohistochemistry. In the aorta obtained from newborn and young subjects, SMCs in the media and thin intima expressed MGP mRNA and, to a lesser extent, ON mRNA. In the adult aorta with fibrous thickening, MGP mRNA was expressed by intimal SMCs and subpopulation of medial SMCs. Osteonectin mRNA was expressed mainly by intimal SMCs and few medial SMCs. Double immunohistochemical staining revealed that both MGP- and ON protein-expressing cells were positive for anti-alpha-smooth muscle actin antibody, aortic SMCs. CONCLUSIONS: These results suggested that MGP and ON expression by aortic SMCs might be regulated by the degree of atherosclerosis and SMC differentiation in human aorta.     

Anin vitro invasion model for human renal cell carcinoma cell lines mimicking their metastatic abilities

We developed a modifiedin vitro invasion assay system using monolayers of vascular endothelial cells. A type I collagen gel was formed in plastic dishes, and overlaid with type IV collagen. Calf pulmonary arterial endothelial (CPAE) cells were seeded onto these plates, and incubated until they reached confluence. Five human renal cell carcinoma cell lines with various metastatic potentialsin vivo were then seeded on the monolayer CPAE cells, and their colony formation and invasion activities were examined for 9 days. At day 4, the highly metastatic cell lines increased the number of colony foci on monolayer CPAE cells several fold higher than their poorly metastatic counterpart. The horizontal spreading patterns were also different between poorly and highly metastatic cell lines. On day 9, the number of carcinoma foci that penetrated the monolayer of CPAE cells and type IV collagen sheets into type I collagen gels in highly metastatic cell lines greatly increased as compared with that of poorly metastatic cell lines. Ourin vitro invasion assay using monolayer CPAE cells would be useful to evaluate protease activities and colony formation during invasion.     

Activities of Aeromonas hydrophila hemolysins and their interaction with erythrocyte membranes.

The activity of hemolysin produced by Aeromonas hydrophila CA-11, isolated from an environmental source, was more sensitive to temperature than that of hemolysin produced by strain AH-1, isolated from a diarrheal case. CA-11 hemolysin failed to elicit hemolysis below 10 degrees C. Immunoblotting analyses showed that both hemolysins formed into oligomers in rabbit erythrocyte membrane even when no hemolysis occurred. suggesting that the binding and the subsequent oligomerization are temperature independent. Sodium salicylate inhibited lysis of rabbit erythrocytes by both hemolysins, but selected monosaccharides and oligosaccharides did not. Thin-layer immunostaining indicated that both hemolysins bound to phosphoglycerides with net negative charge but weakly to the ones with no net negative charge. Neither sphingomyelin nor lysophosphoglyceride reacted with the hemolysins, whereas the hemolysins bound to free fatty acids. These results suggest that the binding of either hemolysin to the membrane component, probably phospholipid, requires both negative charge of the polar head group and suitable hydrophobicity of the nonpolar tails.     

Suitable image parameters and analytical method for quantitatively measuring cerebral blood flow volume with phase-contrast magnetic resonance imaging

The aim of this study was to determine suitable image parameters and an analytical method for phase-contrast magnetic resonance imaging (PC-MRI) as a means of measuring cerebral blood flow volume. This was done by constructing an experimental model and applying the results to a clinical application. The experimental model was constructed from the aorta of a bull and circulating isotonic saline. The image parameters of PC-MRI (repetition time, flip angle, matrix, velocity rate encoding, and the use of square pixels) were studied with percent flow volume (the ratio of actual flow volume to measured flow volume). The most suitable image parameters for accurate blood flow measurement were as follows: repetition time, 50 msec; flip angle, 20 degrees; and a 512 x 256 matrix without square pixels. Furthermore, velocity rate encoding should be set ranging from the maximum flow velocity in the vessel to five times this value. The correction in measuring blood flow was done with the intensity of the region of interest established in the background. With these parameters for PC-MRI, percent flow volume was greater than 90%. Using the image parameters for PC-MRI and the analytical method described above, we evaluated cerebral blood flow volume in 12 patients with occlusive disease of the major cervical arteries. The results were compared with conventional xenon computed tomography. The values found with both methods showed good correlation. Thus, we concluded that PC-MRI was a noninvasive method for evaluating cerebral blood flow in patients with occlusive disease of the major cervical arteries.     

Characterization of Aeromonas sobria hemolysin by use of monoclonal antibodies against Aeromonas hydrophila hemolysins.

Aeromonas sobria produces hemolysin in a form activable with trypsin under defined cultural conditions. In immunoblotting analyses with the culture supernatant of A. sobria, the monoclonal antibody reacting specifically to Aeromonas hydrophila CA-11 hemolysin bound to the 53,000- and 49,000-dalton bands before and after trypsinization, respectively. The monoclonal antibody reacting to A. hydrophila AH-1 hemolysin did not bind either band. A. sobria hemolysin is, therefore, related antigenically to CA-11 hemolysin, while the molecular weights before and after activation differ from those of A. hydrophila hemolysins, being 54,000 and 51,000, respectively. The hemolytic and enterotoxigenic activities of A. sobria hemolysin were both neutralized by the monoclonal antibody against CA-11 hemolysin. It seems, therefore, that the same site on A. sobria hemolysin is responsible for both biological activities.     

Elevated expression of ETS-1 gene in a metastatic, tumorigenic human prostate epithelial cell line transformed by the v-Ki-ras oncogene

We investigated the inhibitory effects of intrasplenic combination therapy with OK-432 and recombinant interleukin-2 (IL-2) on liver metastasis of colorectal carcinoma. Intrasplenic administration group significantly inhibited the development of liver metastasis compared with subcutaneous administration group (p<0.05). Combination therapy significantly inhibited the development of subclinical liver metastasis compared with that in the control group. Combination therapy decreased the percentage of cells expressing CD8a, which may be a part of effective factors of combination therapy, and improved overall survival rate. These findings suggested intrasplenic combination therapy with OK-432 and IL-2 might be effective in inhibiting liver metastasis of colorectal carcinoma.     

Use of the sandwich method with an ultra-high-molecular-weight polyethylene prosthesis and Marlex mesh in sternal reconstruction: Report of a case

A 52-year-old Japanese man with a slow-growing chondroma originating from the sternal bone was referred to our hospital. A subtotal resection of the sternum was performed, hereafter termed the sandwich method, and an originally designed prosthesis made from ultra-high-molecular-weight polyethylene and Marlex mesh was used for reconstruction. The postoperative course was uneventful without any symptoms due to paradoxical movement of the chest or regional abscess, and no disturbance in the movement of the upper limbs, such as a surgical sequelae, was observed.