Elastic Laminar Reorganization Occurs with Outward Diameter Expansion during Collateral Artery Growth and Requires Lysyl Oxidase for Stabilization.

When a large artery becomes occluded, hemodynamic changes stimulate remodeling of arterial networks to form collateral arteries in a process termed arteriogenesis. However, the structural changes necessary for collateral remodeling have not been defined. We hypothesize that deconstruction of the extracellular matrix is essential to remodel smaller arteries into effective collaterals. Using multiphoton microscopy, we analyzed collagen and elastin structure in maturing collateral arteries isolated from ischemic rat hindlimbs. Collateral arteries harvested at different timepoints showed progressive diameter expansion associated with striking rearrangement of internal elastic lamina (IEL) into a loose fibrous mesh, a pattern persisting at 8 weeks. Despite a 2.5-fold increase in luminal diameter, total elastin content remained unchanged in collaterals compared with control arteries. Among the collateral midzones, baseline elastic fiber content was low. Outward remodeling of these vessels with a 10-20 fold diameter increase was associated with fractures of the elastic fibers and evidence of increased wall tension, as demonstrated by the straightening of the adventitial collagen. Inhibition of lysyl oxidase (LOX) function with ß-aminopropionitrile resulted in severe fragmentation or complete loss of continuity of the IEL in developing collaterals. Collateral artery development is associated with permanent redistribution of existing elastic fibers to accommodate diameter growth. We found no evidence of new elastic fiber formation. Stabilization of the arterial wall during outward remodeling is necessary and dependent on LOX activity.

Effect of Valvular Surgery in Carcinoid Heart Disease: An Observational Cohort Study.

CONTEXT: Carcinoid heart disease (NET-CHD) is associated with the development of symptom-limited exercise capacity and high rates of morbidity and mortality. OBJECTIVE: This study sought to determine the survival, cardiac function, and functional class following surgery. DESIGN AND SETTING, AND PATIENTS: This was a retrospective observational cohort study between 2005 and 2015 at a European Centre of Excellence for Neuroendocrine Tumours, Queen Elizabeth Hospital Birmingham. England consisting of 62 consecutive patients referred to the NET-Cardiology Service. INTERVENTIONS: Subjects were assessed at referral using transthoracic echocardiography (with saline contrast) and transesophageal echocardiography, and 77% with confirmed NET-CHD underwent cardiovascular magnetic resonance imaging. Symptomatic patients with concomitant severe valvular dysfunction were referred for surgery with stable NET disease. MAIN OUTCOME MEASURE: Survival of patients with proven NET-CHD following medical and surgical treatments was measure. RESULTS: In total, 47/62 patients were diagnosed with NET-CHD. Thirty-two patients (68%) underwent surgery with bioprosthetic valve replacements in all subjects; tricuspid, n = 31; pulmonary, n = 30; mitral, n = 3; and aortic, n = 3. Four patients underwent concomitant coronary artery bypass grafting. There were 4 (13%) early post-operative deaths. One- and 2-y survival rates after surgery were 75 and 69% compared with 45 and 15% in un-operated patients. Post-operatively, functional class was improved (pre-New York Heart Association Classification [NYHA], 2.6 [0.5] vs post-NYHA, 1.7 [1.1]), P < .05, right-ventricular (RV) size was reduced (136 ml/m(2) [25] vs 71 ml/m(2) [7]; P < .01) with preserved RV ejection fraction (61% ± 9 vs 55% ± 10; P = .26). CONCLUSION: Valve surgery improved functional class and resulted in RV reverse remodelling with improved survival rates at 2 y compared with those not proceeding to operation. These data highlight the importance of close collaboration between NET clinicians, cardiology, and cardiothoracic surgery teams. Early referral can improve functional capacity but more research is needed to define the selection of appropriate candidates and randomized data are needed to define the effect of surgery on prognosis.

Synthesis and pharmacological activity of aminoindanone dimers and related compounds.

A series of N-substituted 3-aminoindanones were synthesised and evaluated for smooth muscle relaxant activity and mediator release inhibition effects. A low level of smooth muscle relaxant activity has been identified in all derivatives. Data have revealed that the significant mediator release inhibition effects observed are related to the nature of the amine substituents. A structure activity relationship is proposed.

Bifunctional antibodies and their potential clinical applications.

Bifunctional antibodies are monovalent, bispecific, antibody-derived molecules. They have been produced by both chemical and biological means. They are thought to have several advantages over monoclonal antibodies in both immunotherapy and immunodiagnosis. Bifunctional antibodies have been shown to be efficient in the targeting of drugs, toxins, radiolabelled haptens and effector cells on to diseased tissues, primarily cancer cells. In addition, bifunctional antibodies have been used to develop novel immunoassays. The full potential of bifunctional antibodies has yet to be realised.

Bifunctional antibodies: concept, production and applications.

Immunoglobulins, or antibodies, are monospecific, bivalent antigen-binding molecules. Bifunctional antibodies are bispecific, with each arm binding to a different antigen, and may be produced by biological or chemical methods. Biological production involves the fusion of two monoclonal antibody-producing hybridomas or of an immunised spleen cell and a hybridoma. The resulting hybrid hybridomas (quadromas or triomas) secrete a mixture of parenteral monoclonal antibodies and bifunctional antibody. In chemical production, the parental monoclonal antibodies can be 'chopped up and reconstituted' to produce the bifunctional antibody only. Bifunctional antibodies have a variety of potential uses. They were originally proposed as an aid to cancer chemotherapy where one of the arms of the antibody would bind to a tumour marker and the other to a drug, toxin, or cytotoxic cell. Functional agents can thus be target directly onto tumour cells, accumulating with higher density, yet with reduced side effects for the patient. Further applications have been proposed involving enzyme immobilization and novel immunoassay techniques. This review describes developments that have taken place in bifunctional antibody technology to date.