Beating-heart mitral valve surgery in patients with poor left ventricular function.
Mitral valve surgery in the presence of poor left ventricular (LV) function is associated with higher mortality. One surgeon's (S. K. N.) evolving practice of mitral valve surgery on the beating heart using normothermic cardiopulmonary bypass (CPB) in a cohort of patients is described.



Between July 2000 and December 2002, 23 patients (13 men, 10 women; mean age 68.6 +/- 4.8 years; range: 54-81 years) with mitral regurgitation and LV ejection fraction <30% undergoing isolated mitral valve repair (n = 4) or replacement (n = 19) were investigated. All patients received maximal drug therapy. Among patients, 17 were in NYHA class III, and six in class IV.



The mean duration of follow up was 17 +/- 14 months, and was complete for all survivors. The visual field of the on-pump beating heart was equal to that of conventional valvular surgery, and technical accuracy was not compromised. The mean ICU and hospital stays were 2.4 +/- 1.3 days and 8.9 +/- 2.6 days, respectively. Mean CPB time was 74.3 +/- 14.8 min. Thirty-day mortality was significantly lower (8.7%) when compared to mean Euroscore-predicted mortality for this high-risk group (16.9%; p <0.001). The medium-term one- and two-year survivals were 87% and 78%, respectively. Mean NYHA class was improved, from 3.6 +/- 0.5 preoperatively to 1.9 +/- 0.7 at follow up (p = 0.037).



On-pump, beating-heart mitral valve surgery is a good option in patients with poor LV function, and is advantageous as conditions for the heart are more physiological with a beating tonus than with cardioplegia.

title: Pulmonary adenocarcinoma is associated with poor long-term survival after surgical resection. Effect of allogeneic blood transfusion.
abstract: The significance of allogeneic blood transfusion in the prognosis of patients with nonsmall lung carcinoma (NSCLC) remains controversial. Reports have suggested that patients with adenocarcinoma have a worse prognosis from cancer than patients with squamous cell carcinoma (SCC), but this evidence is lacking in NSCLC. The objective of the current study was to elucidate the correlation between perioperative allogeneic blood transfusion and the prognosis in patients with adenocarcinoma and SCC.



The study group comprised 329 consecutive patients (172 men and 157 women) with a mean age of 67 years who underwent lung resection between 1996 and 2003 in 1 unit. The clinicopathologic and survival data were compared between 62 patients (42.7%) with adenocarcinoma and 58 patients (48.3%) with SCC who received a perioperative blood transfusion and 83 patients (57.3 %) with adenocarcinoma and 126 patients (61.3%) with SCC who did not.



The overall surgical mortality rate was 3.9% (13 deaths). The median surgical blood loss was 380 mL (range, 125-4500 mL). The mean blood transfusion received was 1.9 U (range, 0-8 U). The overall actuarial 1, 3, and 5-year survival rates in the adenocarcinoma and SCC groups were 82.3%, 49.6%, and 19.4% and 87.9%, 71.7%, and 32.7%, respectively (P = 0.021). Multivariate analysis demonstrated that the factors that appeared to be independent prognostic factors in both groups were T-classification (P < 0.001), lymph node metastasis (P < 0.001), and postoperative complications (P = 0.029). Perioperative blood transfusion was not an independent prognostic indicator in either group.



The current study demonstrated that long-term survival in patients with adenocarcinoma of the lung was significantly worse compared with patients with SCC, but was independent of allogeneic perioperative blood transfusion. The results reaffirmed the importance of tumor invasion and lymph node involvement in the overall poor prognosis of these patients.

title: Cardiac memory in patients with Wolff-Parkinson-White syndrome: noninvasive imaging of activation and repolarization before and after catheter ablation.
abstract: Cardiac memory refers to a change in ventricular repolarization induced by and persisting for minutes to months after cessation of a period of altered ventricular activation (eg, resulting from pacing or preexcitation in patients with Wolff-Parkinson-White syndrome). ECG imaging (ECGI) is a novel imaging modality for noninvasive electroanatomic mapping of epicardial activation and repolarization.



Fourteen pediatric patients with Wolff-Parkinson-White syndrome and no other congenital disease, were imaged with ECGI a day before and 45 minutes, 1 week, and 1 month after successful catheter ablation. ECGI determined that preexcitation sites were consistent with sites of successful ablation in all cases to within a 1-hour arc of each atrioventricular annulus. In the preexcited rhythm, activation-recovery interval (ARI) was the longest (349+/-6 ms) in the area of preexcitation leading to high average base-to-apex ARI dispersion of 95+/-9 ms (normal is approximately 40 ms). The ARI dispersion remained the same 45 minutes after ablation, although the activation sequence was restored to normal. ARI dispersion was still high (79+/-9 ms) 1 week later and returned to normal (45+/-6 ms) 1 month after ablation.



The study demonstrates that ECGI can noninvasively localize ventricular insertion sites of accessory pathways to guide ablation and evaluate its outcome in pediatric patients with Wolff-Parkinson-White syndrome. Wolff-Parkinson-White is associated with high ARI dispersion in the preexcited rhythm that persists after ablation and gradually returns to normal over a period of 1 month, demonstrating the presence of cardiac memory. The 1-month time course is consistent with transcriptional reprogramming and remodeling of ion channels.

title: Social deprivation and primary hyperparathyroidism.
abstract: To investigate the potential relationship between social status or deprivation and the prevalence of primary hyperparathyroidism (PHPT).



We retrospectively identified a cohort of patients diagnosed as having PHPT between 1981 and 2007 from the Scottish Morbidity Records database. The Scottish Index of Multiple Deprivation (SIMD) 2006 quintiles were derived for these patients by using the postal codes. The distribution of the SIMD quintiles was examined to determine the possible influence of deprivation on the incidence of PHPT.



In Scotland between 1981 and 2007, 3,039 patients were diagnosed as having PHPT, in accordance with the International Classification of Diseases code for PHPT. The distribution of the PHPT cohort across the SIMD 2006 quintiles was significantly different from that expected, with a higher representation (27.2%) among the most deprived and a lower representation (14.5%) in the least deprived quintile, in comparison with the 20% expected in each quintile (P<.0001).



The findings in this study suggest that socioeconomic deprivation is associated with an increased risk of developing PHPT.

title: Dissecting the correlation structure of a bivariate phenotype: Common genes or shared environment?
abstract: High correlations between two quantitative traits may be either due to common genetic factors or common environmental factors or a combination of both. In this study, we develop statistical methods to extract the genetic contribution to the total correlation between the components of a bivariate phenotype. Using data on bivariate phenotypes and marker genotypes for sib-pairs, we propose a test for linkage between a common QTL and a marker locus based on the conditional cross-sib trait correlations (trait 1 of sib 1—trait 2 of sib 2 and conversely) given the identity-by-descent (i.b.d.) sharing at the marker locus. We use Monte-Carlo simulations to evaluate the performance of the proposed test under different trait parameters and quantitative trait distributions. An application of the method is illustrated using data on two alcohol-related phenotypes from a project on the collaborative study on the genetics of alcoholism.

title: Interfacial and self-aggregation of binary mixtures of anionic and nonionic amphiphiles in aqueous medium.
abstract: Interfacial and bulk properties of sodium dodecyl sulfate (SDS), polyoxyethylene (20) sorbitan monooleate (Tween-80), and their binary mixtures in aqueous medium have been investigated using surface tension, conductance, and fluorescence measurements at different temperatures. The critical micelle concentration (CMC), counterion binding, polarity index, aggregation number, thermodynamics of interfacial adsorption, and micellization are evaluated. The entropic contribution is found to be the predominant factor in micelle formation. The aggregation number and the polarity index of the micelle interior estimated by the pyrene fluorescence technique show interesting temperature dependence. The size and composition of the mixed micelles vary with the total concentration. The micellar compositions, activities of the individual components in the mixed species, and intersurfactant interactions are also estimated following regular solution theory, excess thermodynamic functions, and a molecular thermodynamic model. The surfactant mixtures are found to be nonideal with a lower degree of counterion binding compared to the individual members. Mixed micelles are nonspherical in nature at all temperatures when the mole fraction (α) of the ionic part in mixtures is high but transform to spherical when α(SDS) is ≤0.50.

title: Elimination of Mercury and Organomercurials by Nitrogen-Fixing Bacteria
abstract: Bacteria isolated from mercury-polluted environments are often resistant to mercuric ions (Hg{sup 2+}) and organomercurials. Plasmids determining mercury resistance have been well characterized in gram-negative system. However, in Staphylococcus aureus mercury resistance has been found to be chromosomally determined. The known mechanism of bacterial Hg{sup 2+}-resistance is detoxification of the toxic Hg{sup 2+} by its enzymatic transformation by mercuric reductase to Hg (o). Organomercurial lyase mediates the degradation of organomercurial compounds to Hg{sup 2+}. Mercury and organomercurial resistances have been studied in different bacterial genera. There is little information on Hg-resistance in N{sub 2}-fixing soil bacteria, however, in many developing countries, including India, mercury pollution is still a problem because Hg-based pesticides and fungicides are still used routinely as seed-dressers in agriculture to control soil-borne and seed-borne fungal diseases. Volatilization of Hg from laboratory media by mercury-resistant bacteria containing low levels of mercury has been reported by several workers. It is interesting to note that N{sub 2}-fixing, Hg-resistant soil isolates could volatilize Hg from medium containing very high amounts of HgCl{sub 2}. In the present paper we report the volatilization patterns of five N{sub 2}-fixing bacterial strains, the effect of different inducers on mercuric reductase, and the pattern of substratemore » utilization by organomercurial lyase. In the presence of a low concentration of HgCl{sub 2}. enzymatic detoxification is sufficient to combat the adverse situation created by the presence of Hg{sup 2+} ions. In the presence of a high concentration of HgCl{sub 2}, intracellular sequestration by Hg{sup 2+} binding components may play an additional role in counteracting Hg-toxicity.« less