Superior vena cava syndrome: relief with a modified saphenojugular bypass graft.

Superior vena cava (SVC) syndrome is a disabling and potentially life-threatening complication. SVC revascularization can be achieved by means of endovascular or direct surgical reconstructions. In the patient on whom we report, these two options were not possible, and a peripheral venous bypass grafting procedure was done with a technical innovation. Right upper-extremity swelling developed in a 55-year-old woman after radiation therapy for lung carcinoma. A left subclavian vein Port-A-Cath induced extensive thrombosis of the left innominate, axillosubclavian, and jugular veins. She was referred to our institution with very symptomatic SVC syndrome after two failed endovascular interventions. The occlusion of both innominate veins and chronic thrombus extending into the left axillosubclavian and internal jugular veins was confirmed by means of a venogram. A third endovascular attempt failed. The presternal skin had severe radiation-induced damage precluding direct SVC reconstruction. A bypass grafting procedure from the right internal jugular to the femoral vein was performed with spliced bilateral greater saphenous veins tunneled inside an externally supported expanded polytetrafluoroethylene graft. Postoperatively, the patient had no symptoms, and graft patency was confirmed by means of duplex ultrasound scanning. A saphenojugular bypass grafting procedure can offer prompt and durable relief of SVC syndrome when endovascular or direct surgical reconstructions are not possible. This rarely used peripheral venous bypass grafting procedure was modified by tunneling the vein graft inside an externally supported polytetrafluoroethylene graft to prevent kinking or compression.

Aortic fenestration for acute or chronic aortic dissection: an uncommon but effective procedure.

BACKGROUND: Aortic fenestration is rarely required for patients with acute or chronic aortic dissection. To better define its role and the indications for its use and to evaluate its success at relieving organ or limb malperfusion, we reviewed our experience with direct fenestration of the aorta. METHODS: A retrospective analysis of all consecutive aortic fenestrations performed between January 1, 1979, and December 31, 1999, was performed. Fourteen patients, 12 men and two women (mean age, 59.6 years; range, 43-81), underwent fenestration of the aorta. All patients were hypertensive and had a history of tobacco use. By Stanford classification, there were three type A and 11 type B patients. In the acute dissection group (n = 7), indications for surgery were malperfusion in six patients (leg ischemia, 4; renal ischemia, 5; bowel ischemia, 3) and intra-abdominal bleeding from rupture in two. In the chronic dissection group (n = 7), indications for surgery were abdominal aortic aneurysm in 4 patients (infrarenal, 3; pararenal, 1), thoracoabdominal aneurysm in 1, hypertension from coarctation of the thoracic aorta in 1, and aortic occlusion with disabling claudication in 1. RESULTS: Emergency aortic fenestration was performed in seven patients (surgically for 6 and percutaneously for 1). Fenestration level was infrarenal in four and pararenal in three. Concomitant abdominal aortic graft replacement was performed in four patients, combined with ascending aortic replacement (n = 1) and bilateral aortorenal bypasses (n = 1). In two patients, acute fenestration was performed for organ malperfusion after prior proximal aortic replacement (ascending aorta, 1; descending thoracic aorta, 1). Seven elective aortic fenestrations were performed for chronic dissection (descending thoracic aorta, 2; paravisceral aorta, 2; infrarenal aorta, 2 and pararenal aorta, 1). Concomitant aortic replacement was performed in six patients (abdominal aorta, 5; thoracoabdominal aorta, 1). Fenestration was successful at restoring flow in all 10 patients with malperfusion. Operative mortality for emergency fenestration was 43% (3/7). The three deaths that occurred were of patients with anuria or bowel ischemia, or both. There were no postoperative deaths for elective fenestration. At a mean follow-up of 5.1 years, there were no recurrences of malperfusion and no false aneurysm formations at the fenestration site. CONCLUSION: Fenestration of the aorta can effectively relieve organ or limb ischemia. Bowel ischemia and anuria are indicators of dismal prognosis and emergency fenestration in these patients carries a high mortality. Elective fenestration combined with aortic replacement can be performed safely in chronic dissection. Aortic fenestration is indicated for carefully selected patients with malperfusion and offers durable benefits.

Pea compound leaf architecture is regulated by interactions among the genes UNIFOLIATA, cochleata, afila, and tendril-lessn.

The compound leaf primordium of pea represents a marginal blastozone that initiates organ primordia, in an acropetal manner, from its growing distal region. The UNIFOLIATA (UNI) gene is important in marginal blastozone maintenance because loss or reduction of its function results in uni mutant leaves of reduced complexity. In this study, we show that UNI is expressed in the leaf blastozone over the period in which organ primordia are initiated and is downregulated at the time of leaf primordium determination. Prolonged UNI expression was associated with increased blastozone activity in the complex leaves of afila (af), cochleata (coch), and afila tendril-less (af tl) mutant plants. Our analysis suggests that UNI expression is negatively regulated by COCH in stipule primordia, by AF in proximal leaflet primordia, and by AF and TL in distal and terminal tendril primordia. We propose that the control of UNI expression by AF, TL, and COCH is important in the regulation of blastozone activity and pattern formation in the compound leaf primordium of the pea.

The relationship between genetic and cytogenetic maps of pea. II. Physical maps of linkage mapping populations.

A cytogenetic analysis of inbred lines that have been used to generate genetic maps of pea is presented. Mitotic karyotyping of the inbred lines and meiotic studies of their F1 hybrids have been used to test the prediction that structural differences exist between the parental lines. The results are not compatible with the previously published molecular data. A reordered and updated linkage map of pea is presented that is consistent with the cytogenetic data.

Isolation by PCR of a cDNA clone from pea petals with similarity to petunia and wheat zinc finger proteins.

The C2H2 TFIIIA/Krüppel class of zinc finger proteins are an important group of regulatory nucleic acid binding factors and have been extensively studied in humans, Drosophila and yeast. We have employed 3' RACE PCR, using a highly degenerate oligonucleotide primer, for the facile isolation of a C2H2 zinc finger protein cDNA (Pszf1) from pea petals. The Pszf1 cDNA open reading frame potentially encodes a protein with two widely separated zinc fingers similar to zinc finger proteins from petunia and wheat. This class of two-fingered zinc finger proteins, possessing a wide and variable linker sequence, appears to be unique to plants. Three regions outside the zinc finger domains are also conserved between the members of the plant zinc finger protein family and one of these regions is a candidate nuclear localisation signal. The Pszf1 amino acid sequence is most similar to that of the petunia Epf1 protein, they possess an interfinger linker sequence of approximately the same length and they have a similar expression pattern with maximal transcript accumulation in mature petals, suggesting that Pszf1 may be the pea homologue of the petunia Epf1 zinc finger gene.

Coordinate regulation of replication and virion sense gene expression in wheat dwarf virus.

We have investigated the relationship between viral DNA replication and virion sense gene expression in wheat dwarf virus (WDV), a member of the geminivirus group, by testing a series of deletion mutants in transfected Triticum monococcum (einkorn) protoplasts. Mutants contained a transcription fusion of the chloramphenicol acetyltransferase coding sequence to the virion sense promoter that replaced the viral coat protein coding sequence. The deletion analysis revealed that WDV replication and virion sense transcription can proceed independently and are controlled in part by nonoverlapping elements in the large intergenic region. These data and those from a C2 open reading frame (ORF) frameshift mutant also showed that the product of the C2 ORF (C1-C2 protein) is independently involved in both DNA replication and activation of the virion sense promoter. The amino acid sequences encoded by C2, which are highly conserved in the geminivirus group, show some homology to the DNA binding domain of the myb-related class of plant transcription factors. The possible involvement of the host in controlling the function of the C1-C2 protein and the implication of these data for the development of WDV-based gene vectors are discussed.