Is vertical vein ligation necessary in repair of total anomalous pulmonary venous connection?

BACKGROUND: In the repair of total anomalous venous connection, vertical vein ligation is recommended to eliminate left-to-right shunting. However, the small left heart chambers may not always tolerate the immediate increase in blood flow after combined repair and vein ligation. METHODS: A retrospective review of 23 infants and children undergoing correction of total anomalous pulmonary venous connection was undertaken to determine whether vertical vein ligation is a necessary component of successful surgical repair. In 14 patients this vein was ligated, whereas in 9 it was left patent. Six patients who underwent ligation and 5 who did not had pulmonary venous obstruction before operation. RESULTS: The operative mortality rate was 36% (5 of 14 patients) for the ligated group compared with 0% (0 of 9 patients) for the nonligated group (p = 0.06). All deaths occurred in patients with preoperative obstruction and a low mean left atrial pressure, and four of the deaths were directly attributable to left heart failure. Follow-up echocardiography in patients in whom the vertical vein was not ligated revealed adequate cardiac function and no residual left-to-right flow through the previously patent venous conduit. CONCLUSION: Vertical vein ligation during the repair of total anomalous pulmonary venous connection is not routinely necessary and actually may be undesirable in patients with preoperative obstruction, in whom the left heart chambers are particularly small.     

The value of colonic exfoliative cytology in the diagnosis of carcinoma of the large intestine

We have attempted to summarize the current controversies regarding risk factors and preventive measures for control of arteriosclerosis and coronary heart disease. Recognizing that the genesis and development of the disease process are extremely complex and the basic knowledge is limited, it is not likely that conclusive answers to questions will be forthcoming soon which will provide more effective preventive or therapeutic measures. It might be desirable to institute educational and control program aimed at curtailing, at a young age, known AS risk factors such as heavy smoking, particularly if the family history indicates severe risk. Few will question the normal approaches to the treatment of complications of coronary heart disease by control of hypertension, elevated cholesterol, and smoking. However, great caution must be exercised when trying to institute large scale modifications in prevailing life patterns, particularly when based on indefinite risk factor studies and in the face of potentially profound and frequently unknown consequences. The unknowns of atherosclerotic heart disease risk factors, coupled with uncertainties and even doubts about protracted and expensive population studies, lead us to propose an emphasis on alternate selective approaches. We strongly believe that fundamental to progress in the field of arteriosclerosis is an amplification of preventive research efforts with stronger attention focused upon influencing the atherosclerotic processes within the arterial wall. But, more immediately, we urge systematic gathering and careful evaluation of patient data in particular population subsets which exhibit and accelerated mode of arteriosclerosis. Comparative studies of patients, particularly twins, families, and ethnic populations with redilection to early or accelerated arteriosclerosis may be extremely rewarding. Our repeated review of the enormous literature suggests that worldwide collaboration is needed to perfect more meaningful protocols as well as to correlate and critically evaluate existing data provided by population studies of this insidious disease process which represents an evermounting burden to society.     

Effects of annealing in O2 and N2 on the electrical properties of tantalum oxide thin films prepared by electron cyclotron resonance plasma enhanced chemical vapor deposition

The tantalum oxide thin films with a thickness of 14 nm were deposited at 95°C by electron cyclotron resonance plasma enhanced chemical vapor deposition (ECRPECVD), and annealed at various temperatures (700∼850°C) in O₂ and N₂ ambients. The microstructure and composition of the tantalum oxide thin films and the growth of interfacial silicon oxide layer were investigated and were related to the electrical characteristics of the film. Annealing in an O₂ ambient led to a high dielectric constant (ε_r(Ta₂O₅) = 24) as well as a small leakage current (E_bd = 2.3 MV/cm), which were due to the improved stoichiometry and the decreased impurity carbon content. Annealing in an N₂ ambient resulted in poor and nonuniform leakage current characteristics. The as-deposited tantalum oxide films were crystallized into δ-Ta₂O₅ after annealing at above 750°C regardless of the ambient. The leakage current of the film abruptly increased after annealing at 850°C probably because of the stress caused by thermal expansion or contraction.     

Novel synthetic inhibitors of selectin-mediated cell adhesion: synthesis of 1,6-bis[3-(3-carboxymethylphenyl)-4-(2-alpha-D- mannopyranosyloxy)phenyl]hexane (TBC1269)

Reports of a high-affinity ligand for E-selectin, sialyl di-Lewis(x) (sLe(x)Le(x), 1), motivated us to incorporate modifications to previously reported biphenyl-based inhibitors that would provide additional interactions with the protein. These compounds were assayed for the ability to inhibit the binding of sialyl Lewis(x) (sLe(x), 2) bearing HL-60 cells to E-, P-, and L-selectin fusion proteins. We report that dimeric or trimeric compounds containing multiple components of simple nonoligosaccharide selectin antagonists inhibit sLe(x)-dependent binding with significantly enhanced potency over the monomeric compound. The enhanced potency is consistent with additional binding interactions within a single selectin lectin domain; however, multivalent interaction with multiple lectin domains as a possible alternative cannot be ruled out. Compound 15e (TBC1269) showed optimal in vitro activity from this class of antagonists and is currently under development for use in the treatment of asthma.     

Root caries in a sample of elderly persons

With the anticipated increase in the aged adult population and the associated gingival recession, the prevalence of root caries is expected to increase. The purpose of this study was to determine the experience and distribution of root caries in a group of aged adults living in Kayelitsha. All non-institutionalized elderly black adults participating in a community geriatric programme were examined. Root caries was recorded using visual and tactile criteria and expressed as the root caries index (RCI) rate. The mean age of the subjects was 65.2 years, the mean number of teeth present was 17.3 and the mean RCI rate was 2.2 per cent. All subjects had gingival recession while only 23.8 per cent had root caries. No surfaces with restored root caries lesions were found. In the maxilla the highest RCI rate was observed on the interproximal surfaces of the posterior teeth (4.4 per cent) but in the mandible the buccal surfaces of the posterior teeth had the highest RCI rate (4.2 per cent). In both the maxilla and the mandible the lingual surfaces of the anterior teeth showed no root caries. Maxillary teeth did not have a significantly higher root caries attack rate than mandibular teeth. Root caries does not appear to be a public health problem in the sampled population.     

Association of beta-agonists with corresponding beta 2- and beta 1-adrenergic pentapeptide sequences

Synthesized beta 1- and beta 2-pentapeptide sequences corresponding to published adrenoceptor transmembrane activation site subtypes were investigated in vitro for selectivity in association for drug ligands of known selectivity. Both nuclear magnetic resonance spectroscopy and molecular mechanics demonstrated that structural differences among the corresponding pentapeptide activation-site sequences can explain agonist selectivity. Results suggest the agonists bind across the activation site loop on the second transmembrane alpha-helix by dipole/dipole interactions between a ligand and the peptide. Since electrostatic interactions within the membrane may determine the rate of intercellular ion flux, agonist association across the activation site sequence could thereby decrease electrostatic resistance to positive ion flux into the cell. Interactions between the peptides and the ligands may provide insight into the structures and mechanisms involved in association of ligands for the identical sequences on the beta-adrenoreceptors.