Spatiotemporal expression of C-CAM in the rat placenta

We investigated the expression of the immunoglobulin superfamily cell adhesion molecule, C-CAM, in developing and mature rat placenta. By immunohistochemical staining at the light microscopic level, no C-CAM-expression was seen before Day 9 of gestation, when it appeared in the trophoblasts of ectoplacental cones. On Day 10.5, spongiotrophoblasts and invasive trophoblasts around the maternal vessels of the decidua basalis were stained positively. On Day 12.5, C-CAM was detected in the spongiotrophoblasts of the junctional layer, but labyrinth trophoblasts and secondary giant trophoblasts were not stained. On Day 17.5, C-CAM was found only in the labyrinth and lacunae of the junctional layer. At this stage, both the labyrinth cytotrophoblasts of the maternal blood vessels and the endothelial cells of the embryonic capillaries were strongly stained. Placental tissues from gestational Days 12.5 and 17.5 were analyzed by immunoelectron microscopy to determine the location of C-CAM at the subcellular level. On Day 12.5, positive staining of the spongiotrophoblasts was observed, mainly on surface membranes and microvilli between loosely associated cells. On Day 17.5, staining was found primarily on the microvilli of the maternal luminal surfaces of the labyrinth cytotrophoblasts, and both on the luminal surface and in the cytoplasm of endothelial cells of the embryonic vessels. RT-PCR analysis and Southern blotting of the PCR products revealed expression of mRNA species for both of the major isoforms, C-CAM1 and C-CAM2. Immunoblotting analysis of C-CAM isolated from 12.5-day and 14.5-day placentae showed that it appeared as a broad band with an apparent molecular mass of 110-170 kD. In summary, C-CAM was strongly expressed in a specific spatiotemporal pattern in trophoblasts actively involved in formation of the placental tissue, suggesting an important role in placental development. In the mature placenta, C-CAM expression was confined to the trophoblastic and endothelial cells lining the maternal and embryonic vessels, respectively, suggesting important functions in placental physiology.     

Minimally invasive cardiac surgery: current status and perspective

This study investigated the features of calf deep vein thrombosis (DVT) as a pulmonary embolic source. Fifty-eight lower limbs in 29 patients who were suspected of having DVT distal to the popliteal vein were screened by ultrasonography. Then, ascending venography was performed to confirm the diagnosis. Pulmonary embolism (PE) was diagnosed in suspected patients by use of pulmonary perfusion scanning or pulmonary angiography. Venography revealed calf DVT in 33 limbs in 28 patients. Of 28 patients, six had symptomatic PE. Thrombosis was found in the muscle veins in 18 limbs, the trunk veins in 11, and both veins in four. Isolated single vein thrombosis was found in the soleal vein in 14 limbs (42%), the posterior tibial vein in eight, the peroneal vein in two, and the gastrocnemius vein in two. The overall percentage of soleal vein thrombi was 61%. All six patients with symptomatic PE had isolated soleal vein thromboses. Calf DVT was a pulmonary embolic source when isolated thrombosis of the large soleal vein was more than 7 mm in diameter. Soleal veins were the most frequent and important location of calf DVT, suggesting that these were an occasional embolic source of critical PE.     

The earlier detection of myocardial damage in open heart surgery using serum human heart fatty acid-binding protein

Human heart fatty acid-binding protein (HH-FABP), which is a low molecular weight protein and abundant in the cytoplasm of myocardial cells, is reported to be released into the circulation shortly after the onset of acute myocardial damage. However, the changes in serum HH-FABP levels in open heart surgery have not been elucidated. To determine whether HH-FABP enables the earlier detection of myocardial damage caused by ischemia-reperfusion in open heart surgery, we measured the serial levels of serum HH-FABP, CK-MB and Troponin T (TnT) at every 15 min for 48 hours after reperfusion in 10 adult patients with coronary artery bypass graft. The serum HH-FABP levels reached the peak within 60 min after reperfusion (mean +/- SD; 49 +/- 7 min), and this was significantly (p < 0.001) earlier than CK-MB (212 +/- 108 min) and TnT (244 +/- 150 min). The peak value of serum HH-FABP had a significant correlation to the peak value of serum CK-MB or TnT (r = 0.815, p = 0.02; r = 0.925, p = 0.0001, respectively). These results indicate that serum HH-FABP enables the earlier detection of myocardial damage than the other markers in the patients with open heart surgery.     

Expression of glucose transporters in rat brain following transient focal ischemic injury

To better understand genetic diversity of mammalian reoviruses, we studied sequence variability in the S3 gene segment of 17 field-isolate reovirus strains and prototype strains of the three reovirus serotypes. Strains studied were isolated over a 37-year period from different mammalian hosts and geographic locations. A high degree of variability was observed in the nucleotide sequences of the S3 gene, whereas the deduced amino acid sequences of the S3 gene product, sigma NS, were highly conserved. When variability among the S3 nucleotide sequences was analyzed using pairwise comparisons, we found that 5' and 3' noncoding regions were significantly more conserved than the remainder of the gene. This high degree of sequence conservation was also observed within the first 15 nucleotides of the 5' coding region. Phylogenetic analyses showed that multiple alleles of the S3 gene cocirculate and that genetic diversity in the S3 gene does not correlate with host species, geographic locale, or date of isolation. Phylogenetic trees constructed from variation in the S3 sequences are distinct from those previously generated from sequences that encode attachment protein sigma 1, core protein sigma 2, and outer capsid protein sigma 3, which supports the hypothesis that reovirus gene segments reassort in nature. These findings suggest that reovirus gene segments are well-adapted to mammalian hosts and that reovirus evolution has reached an equilibrium.     

Conditions for complete self-healing breakdown in glow discharge polymerized styrene films

Breakdown patterns of glow discharge polymerized styrene film sandwiched between the top and base electrodes and fabricated on a glass substrate have been observed with a microscope. The breakdown patterns can be classified into three types: a broad ring of partly vanishing top electrode metal occuring around the breakdown hole in the dielectric (type A); a large hole made through the three layers (one dielectric and two metal layers), the dielectric film and the top electrode being folded back together at the periphery of the hole and the base electrode being melted over the hole area (type B); successive breakdown around the periphery of previous breakdown spots (type P). These patterns are interpreted in terms of the action of an arc across an extremely short gap as well as joule heating. Type A is preferable for attaining complete self-healing and the conditions that most favour the occurrence of type A holes are (a) the application of a positive voltage to the top electrode and (b) the top electrode being thin compared with the base electrode.     

Transfer to a nitrocellulose membrane allows of the bone forming activity of bone morphogenetic protein

When we purify bone morphogenetic protein (BMP), its activity diminishes, and the quantity we are able to extract decreases. It is difficult to evaluate the effects of each of the processes involved in BMP purification because it is unstable. In order to resolve the problem, a modified bioassay method using only slight quantities of BMP which do not decrease its bone-forming activity, is needed. We transferred BMP separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE) onto nitrocellulose membranes (NC) and cut out the bands. Then we used each band as implanted material. The NC membrane firmly bound the BMP activity fraction and held it in the implantation area of the mouse thigh. No formation of bone-like tissue was detected histologically at 14 days after the implantation, but, by 21 days after implantation, cartilage like tissue had clearly formed and newly formed bone was seen by 28 days. By implanting BMP transferred to individual NC membranes, we could perform a bioassay easily with small amounts of BMP without any reduction in activity.     

An application of the residual voltage for diagnoses for detecting irradiated degradation of insulating materials

Electrical cables in nuclear power generating stations must be highly reliable. For further improvement of reliability, the development of nondestructive diagnoses seems desirable for cable maintenance. The authors have been studying residual voltage for developing a diagnosis of electrical cables. The purpose of this paper is to give a foundation for development of diagnostic technology for detecting the irradiated degradation; the relations between γ-irradiation dose and the leakage current, the discharge current, and the residual voltage were studied and attempts made to calculate the amount of polarized charge and characteristic dielectric relaxation times by using data on the residual voltage. The calculated results agreed with the results obtained from the leakage current and the discharge current. These results suggest that the residual voltage in diagnostic technology for detecting the irradiated degradation can be employed.     

Reliability and maintainability of a multicomponent series-parallel system with simultaneous failure and repair priorities

This paper considers a system consisting of two subsystems connected in series with a single repair facility. One subsystem is K-out-of-N:G system consisting of N identical units, while the other consists of M different units connected in series. The life-times of the active units depend on each other in having simultaneous failure of all the operating units and repair times are distributed quite generally. The system breaks down if more than (N?K+1) units in the parallel group are simultaneously in the failed states or if any failure occures in the series group. The availability and reliability function of the system are obtained simultaneously. Explict expressions for the steady state availability of the system and the mean time to the first system failure are obtained.     

Coexpression of platelet-derived growth factor receptor alpha and fetal liver kinase 1 enhances cardiogenic potential in embryonic stem cell differentiation in vitro

Nascent mesodermal cells derived from EB5 embryonic stem (ES) cells were sorted in terms of cardiogenic potential on the basis of their expression levels of platelet-derived growth factor receptor alpha (PDGFRalpha) and fetal liver kinase 1 (Flk-1). The sorted cells were cocultured with OP9 stromal cells to induce terminal differentiation into contractile cardiac colonies. A significant number of cardiac colonies were found in the Flk-1+/PDGFRalpha+ fraction. The enrichment double-positive fraction produced approximately fivefold more cardiac colonies than the Flk-1+/PDGFRalpha- fraction and 10-fold more than the Flk-1-/PDGFRalpha+ fraction. To investigate the involvement of these markers in embryonic cardiogenesis, the cells that disseminated from the E7.5-7.75 embryos were fractionated and seeded on OP9 cells. The cardiogenic potential was markedly enhanced in the Flk-1+/PDGFRalpha+ fraction. These results suggest that some of the precursor cells coexpressing these markers are selectively involved in cardiogenic events, and that the identification of ES-cell-derived precursors with these markers will contribute to the effective production of cardiomyocytes for cell therapies.