Gnetales, one of the extant gymnosperm orders, has traditionally been recognized to be most closely related to flowering plants, because the reproductive organ of Gnetales has some morphological characteristics similar to flowering plants. Most recent molecular phylogenetic studies do not support the sister relationship of the Gnetales and flowering plants, but instead support a close relationship between Gnetales and other extant gymnosperms. The MADS genes are transcription factors, some of which are involved in reproductive organ development in flowering plants. To resolve the discrepancy in phylogenetic inferences, and to provide insights into the evolution of reproductive organs in seed plants, four MADS genes (GpMADS1-4) were cloned from Gnetum parvifolium. GpMADS2 is likely to be a pseudogene and the other three genes were characterized. A MADS gene tree based on partial amino acid sequences showed that GpMADS3 is included in the AGL6 group, but the other two genes do not cluster with any previously reported MADS gene. The three GpMADS genes were expressed during the early stage of ovule development in the differentiating nucellus and three envelopes. A comparison of MADS gene expression among conifers, Gnetum, and flowering plants suggests that the comparable reproductive organs in Gnetum and flowering plants evolved in parallel, and is likely to support the homology between the ovule-ovuliferous scale complex of conifers and the Gnetum ovules, including the three envelopes.

Amino Acid Sequence↗

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False aneurysms after aortic operations.

Between 1980 and August 1991, we encountered 11 non-infected aortic pseudoaneurysms after aortic surgery. The interval between the initial operation and revision varied from 1.8 to 26.8 years (mean 15.2 years). Three were found more than 20 years after operation. Pulling off of and degrading of the silk sutures were considered to be the causes. All patients underwent operative correction without mortality. In thoracic aortic pseudoaneurysm repair, a temporary bypass between the right axillary artery and left external iliac artery was generally adopted. There was no need for heparinization with this technique.

Adult↗

PubMedDate not supplied

Esmarch's bandage technique in distal bypass surgery.

Esmarch's rubber bandage technique has been applied to 49 distal bypass surgeries in 46 patients during the past ten years. The primary and secondary patency rates at 5 years after femoro-tibial bypass surgery were 82% and 92%, respectively. This technique has the following advantages: (1) it minimizes surgical injury of the arterial wall because there is less dissection around the anastomotic site; (2) it decreases scar formation in the anastomotic area after surgery; (3) it maintains abundant muscular blood flow by preserving small branches to muscles, and (4) it provides a bloodless surgical field and easy handling for fine sutures without using vascular clamps. We consider that the avoidance of long circumferential dissection of the artery may play an important role in improving long-term patency in distal bypass surgery.

Adult↗

PubMedDate not supplied

Perianastomotic findings in canine endothelial cell seeded grafts at 3 months.

Endothelial cell seeding is one of the methods commonly used to prepare an antithrombogenic surface for small caliber vascular prostheses. In this study, we investigated the perianastomotic tissue reaction of seeded grafts, using a canine model. Eight dogs were used to harvest endothelial cells (ECs) enzymatically from their external jugular veins, with one dog being excluded because of infection. ECs were cultured and seeded, using a rotation method, onto a small caliber prosthesis woven with ultrafine polyester fibers. Each graft was implanted into the carotid artery of its cell donor dog, with another implanted contralaterally as a non seeded control. Two of seven seeded grafts were patent at 3 months, while all controls were occluded. Histologic examination revealed a continuous lining of ECs in the patent grafts, but thickening of the intima at the anastomoses was also observed. The occluded seeded grafts had organized hard thrombi and thick fibrosis at the perianastomotic area, however, with few thrombi in the midportion. These observations suggest that the investigation of a small caliber prosthesis with the ultimate aim of producing better patency should focus not only on antithrombogenicity of the surface of the lumen, but also on the perianastomotic biologic reaction.

Animals↗