THE LIMA SUCCESS STORY — WHITHER OTHER ARTERIAL GRAFTS — ARE VEIN GRAFTS OBSOLETE ?

SUMMARY The long-term benefit of myocardial revascularisation depends largely upon the continued patency of bypass grafts, but the long-term patency of vein grafts is poor. To improve the results of myocardial revascularisation, either measures to increase the patency of saphenous vein grafts or alternative conduits are required. Use of the left internal mammary artery as a graft is known to increase survival, and this has prompted wider use of other arterial grafts in the expectation that they will further enhance the long-term results of coronary artery bypass. This policy is based upon sound theory, but convincing evidence that it improves survival is lacking. Meanwhile, advances in the understanding of the pathology of vein graft occlusion have given rise to new methods of increasing vein graft patency. While these techniques are, as yet, only experimental, if translated into clinical practice, the places of arterial and venous grafts may require further assessment.     

Adhesion of committed human hematopoietic progenitors to synthetic peptides from the C-terminal heparin-binding domain of fibronectin: cooperation between the integrin alpha 4 beta 1 and the CD44 adhesion receptor

Close interaction of human hematopoietic progenitors with the bone marrow microenvironment is important for the ordered progression of human hematopoiesis. Progenitor cell adhesion to stroma has a complex molecular basis, involving various cell-extracellular matrix and cell- cell interactions. We have previously shown that adhesion of colony- forming cells (CFC) to fibronectin, present in stromal extracellular matrix, involves multiple sites, including two heparin-binding synthetic peptides (FN-C/H I and FN-C/H II) and the alpha 4 beta 1 integrin-binding peptide CS1. These synthetic peptides are located in close proximity in the type III repeat 14 and the immediately adjacent type IIIcs region of fibronectin. In the current study, we evaluate receptors expressed by CFC responsible for their adhesion to fibronectin. We show that the alpha 4 beta 1 integrin mediates adhesion to CFC to the peptides FN-C/H I and CS1. Adhesion of CFC to fibronectin is also mediated by proteoglycans, because removal of cell surface chondroitin-sulfate proteoglycans resulted in decreased adhesion of CFC to FN-C/ I and FN-C/H II. The core protein of this proteoglycan was identified by immunoprecipitation as a 90-kD member of the CD44 group of adhesion molecules. Interestingly, although the proteoglycan core protein failed to adhere to FN-C/H II affinity columns, anti-CD44 monoclonal antibodies blocked CFC adhesion to FN-C/H II, indicating that these monoclonal antibodies may interfere with core protein- mediated intracellular signalling. Finally, we show that CD44 and alpha 4 beta 1 may cooperate in establishing progenitor adhesion, because anti-CD44 antibodies potentiated the adhesion-inhibitory effects of suboptimal concentrations of anti-alpha 4 or anti-beta 1 monoclonal antibodies. These results provide a working model for progenitor cell recognition of fibronectin (and possibly the marrow micro-environment) in which the coordinated action of integrins and cell surface proteoglycans is necessary for cell adhesion. This model can now be used to study the complex relationship between progenitor cell adhesion and the regulation of their proliferation and differentiation.     

Pregnancy after uterine artery embolization for the treatment of myomas: a case series

Purpose

Uterine artery embolization (UAE) has become an alternative therapy for the treatment of symptomatic myomas. The questions of fertility and pregnancy outcome after uterine artery embolization are still not answered. The study presents the results of pregnancies after UAE. The main goal was to evaluate the course of these pregnancies and concentrate on possible complications.

Methods

This was a prospective study from June 2009 till October 2011. Patients with symptomatic uterine myomas were included. The evaluation of the symptoms was done by quality of life questionnaire and bleeding charts. UAE was performed by superselective microcatheterization technique. Women still planning pregnancy were included in the study after signing detailed informed consent. Pregnant women after UAE were followed as high-risk pregnancies.

Results

A total of 98 patients underwent uterine artery embolization for symptomatic myomas; 21 expressed their wish to become pregnant, out of which 6 had successful spontaneous conception (23.08 %) and 1 patient was pregnant twice, and altogether there were seven pregnancies. During gestation and delivery, there was no serious complication. There was one missed abortion and one placental retention. Myomas did not show growth pattern during pregnancy.

Conclusions

Data from further prospective, randomized trials comparing fertility and pregnancies after UAE with other treatment modalities are needed. UAE, with the new techniques of superselective microcatheterization, could be, in the future, a possible approach even in women with future maternity plans.     

Tracheobronchial tree and pulmonary arteries: MR imaging using electronic axial rotation

Standard coronal magnetic resonance (MR) imaging cannot depict long segments of the tracheobronchial tree and left pulmonary artery owing to the normal thoracic kyphosis and posteriorly angled course of these structures. By the use of electronic axial rotation (EAR), however, MR is capable of imaging any plane. We used EAR in 25 patients undergoing MR examinations of the thorax. This technique allowed superior definition of the longitudinal axis of the tracheobronchial tree and left pulmonary artery. The right pulmonary artery was satisfactorily imaged by the standard coronal plane.     

Brain lactate in preterm and growth–retarded neonates

Glucose is the predominant cerebral energy source under physiological conditions, although other substrates may support cerebral metabolism. The present study was undertaken to determine if lactate is present in the immature human brain, and if so, whether or not concentrations of lactate differ between small–for–gestational–age and appropriate–for–gestational–age infants. Thirty stable, healthy infants with normal brains were investigated. As the only nutrient, all received milk enterally prior to the investigation, which was carried out without sedation. Mean gestational age was 35 completed weeks (range 28–41 weeks) and mean birth weight was 2170g (range 855–4100 g). Proton nuclear magnetic resonance spectra from the striatal region were obtained while the infants were sleeping quietly. Lactate was present in all 10 preterm small–for–gestational–age and 10 of 13 preterm appropriate–for–gestational–age infants, and the concentration was inversely related to postmenstrual age ( p < 0.002). In addition, lactate increased with the degree of growth retardation ( p < 0.01). At present the significance of lactate is unclear. Lactate may be produced locally or in peripheral tissues, and may support brain metabolism.