Standardization of an isolated pig heart preparation with parabiotic circulation: methodological considerations

In the present study we standardized an experimental model of parabiotic circulation of isolated pig heart. The isolated heart was perfused with arterial blood from a second animal as support and submitted to regional ischemia for 30 min, followed by total ischemia for 90 min and reperfusion for 90 min. Parameters for measurement of ventricular performance using different indices measured directly or indirectly from intraventricular pressure were defined as: maximum peak pressure, final diastolic pressure, pressure developed, first derivative of maximum pressure (dP/dt max), first derivative of minimum pressure (dP/dt min), systolic stress of the left ventricle (sigmas), and maximum elastance of the left ventricle. Isolated hearts subjected to regional and global ischemia presented significant worsening of all measured parameters. Less discriminative parameters were dP/dt max and dP/dt min. Elastance was the most sensitive parameter during the reperfusion period, demonstrating an early loss of ventricular function during reperfusion. The model proved to be stable and reproducible and permitted the study of several variables in the isolated heart, such as ischemia and reperfusion phenomena, the effects of different drugs, surgical interventions, etc. The model introduces an advantage over the classical models which use crystalloid solutions as perfusate, because parabiotic circulation mimics heart surgery with extracorporeal circulation.64965

A Bovine Pericardium Rigid Prosthesis For Left Ventricle Restoration: 12 Years Of Follow-up [prótese Rígida De Pericárdio Bovino Para Remodelamento Ventricular Esquerdo: 12 Anos De Seguimento]

Background: Myocardial infarction might result in dilated left ventricle and numerous techniques have been described to restore the original left ventricle shape and identify tools for late survival assessment. The aim of this study is to compare our experience with a modified Dor procedure using a rigid prosthesis to the septal anterior ventricular exclusion procedure (SAVE) for left ventricle restoration. The EuroScore index for prediction of late follow up survival was evaluated. Methods: We evaluated 80 patients who underwent left ventricle restoration between 1999 to 2007 and eight patients were excluded with incomplete data. A modified Dor procedure with rigid prosthesis (MD group) was performed on 53 patients and 19 underwent the septal anterior ventricular exclusion procedure (SAVE group). The patients were classified according their left ventricle shape as type I, II or III. Kaplan-Meier and Cox proportional hazard ratio regressions analysis were performed to assess survival after both techniques and expected surgical mortality using EuroScore index ranking after 12 years of follow up. Results: The operative mortality was comparable in both groups ranked by EuroScore index. The groups were comparable for all clinical data, except the MD group had more patients using intra-aortic balloon pumps before surgery, (5.7% vs. 0; P<0.01). Kaplan Meier analysis by left ventricle shape showed comparable survival for all patients, with slightly higher survival for type I. Kaplan Meier analysis of all death showed equivalent survival curves for both techniques after 12 years of follow up (71.5 ± 12.3 vs. 46.6 ±20.5 years; P=0.08). Kaplan Meier analysis of EuroScore index for all patients showed a difference between the three ranked categories, i.e., 0 to 10%, 11 to 49% and higher than 50% expected surgical mortality after 12 years of follow up (70.9 ± 16.2 vs. 67.5 ± 12.7 vs. 53.0 ± 15.5; P=0.003). Conclusion: The MD procedure showed consistent ejection fraction improvements after long term follow up. Survival was comparable for all ventricular types and for the MD and SAVE procedures. The EuroScore index is a useful index for late survival assessment of ventricular restoration techniques.262164172Cooley, D.A., Hallman, G.L., Henly, W.S., Left ventricular aneurysm due to myocardial infarctionexperience with 37 patients undergoing aneurysmectomy (1964) Arch Surg, 88, pp. 114-121Jatene, A.D., Left ventricular aneurysmectomy. Resection or reconstruction (1985) J Thorac Cardiovasc Surg, 89 (3), pp. 321-331Dor, V., Saab, M., Coste, P., Kornaszewska, M., Montiglio, F., Left ventricular aneurysm: A new surgical approach (1989) Thorac Cardiovasc Surg, 37 (1), pp. 11-19Dor, V., Sabatier, M., di Donato, M., Montiglio, F., Toso, A., Maioli, M., Efficacy of endoventricular patch plasty in large postinfarction akinetic scar and severe left ventricular dysfunction: Comparison with a series of large dyskinetic scars (1998) J Thorac Cardiovasc Surg, 116 (1), pp. 50-59Braile, D.M., Mustafa, R.M., Ardito, R.V., Zaiantchick, M., Coelho, W.M., (1991) Correction of the Left Ventricle Geometry with Semi Rigid Bovine Pericardial Prosthesis Rev Bras Cir Cardiovasc, 6 (2), pp. 109-115Isomura, T., Horii, T., Suma, H., Buckberg, G.D., Septal anterior ventricular exclusion operation (Pacopexy) for ischemic dilated cardiomyopathy: Treat form not disease (2006) Eur J Cardiothorac Surg, 29 (SUPPL. 1), pp. S245-S250. , RESTORE GroupJones, R.H., Velazquez, E.J., Michler, R.E., Sopko, G., Oh, J.K., O'Connor, C.M., Coronary bypass surgery with or without surgical ventricular reconstruction (2009) N Engl J Med, 360 (17), pp. 1705-1717di Donato, M., Castelvecchio, S., Kukulski, T., Bussadori, C., Giacomazzi, F., Frigiola, A., Surgical ventricular restoration: Left ventricular shape influence on cardiac function, clinical status, and survival (2009) Ann Thorac Surg, 87 (2), pp. 455-461Najafi, M., Sheikhvatan, M., Montazeri, A., Sheikhfathollahi, M., Predictors of quality of life among patients undergoing coronary artery bypass surgery (2008) Acta Cardiol, 63 (6), pp. 713-721Messaoudi, N., de Cocker, J., Stockman, B.A., Bossaert, L.L., Rodrigus, I.E., Is EuroSCORE useful in the prediction of extended intensive care unit stay after cardiac surgery? (2009) Eur J Cardiothorac Surg, 36 (1), pp. 35-39Santarpino, G., Onorati, F., Rubino, A.S., Abdalla, K., Caroleo, S., Santangelo, E., Preoperative intraaortic balloon pumping improves outcomes for high-risk patients in routine coronary artery bypass graft surgery (2009) Ann Thorac Surg, 87 (2), pp. 481-488Nashef, S.A., Roques, F., Michel, P., Gauducheau, E., Lemeshow, S., Salamon, R., European system for cardiac operative risk evaluation (EuroSCORE) (1999) Eur J Cardiothorac Surg, 16 (1), pp. 9-13Dor, V., Sabatier, M., di Donato, M., Maioli, M., Toso, A., Montiglio, F., Late hemodynamic results after left ventricular patch repair associated with coronary grafting in patients with postinfarction akinetic or dyskinetic aneurysm of the left ventricle (1995) J Thorac Cardiovasc Surg, 110 (5), pp. 1291-1299Athanasuleas, C.L., Buckberg, G.D., Stanley, A.W., Siler, W., Dor, V., Didonato, M., RESTORE Group. Surgical ventricular restoration: The RESTORE Group experience (2004) Heart Fail Rev, 9 (4), pp. 287-297Salati, M., di Biasi, P., Paje, A., Santoli, C., Left ventricular geometry after endoventriculoplasty (1993) Eur J Cardiothorac Surg, 7 (11), pp. 574-578Buckberg, G.D., Coghlan, H.C., Torrent-Guasp, F., The structure and function of the helical heart and its buttress wrapping. VI. Geometric Concepts of Heart Failure and Use For Structural Correction (2001) Semin Thorac Cardiovasc Surg, 13 (4), pp. 386-401di Donato, M., Sabatier, M., Dor, V., Gensini, G.F., Toso, A., Maioli, M., Effects of the Dor procedure on left ventricular dimension and shape and geometric correlates of mitral regurgitation one year after surgery (2001) J Thorac Cardiovasc Surg, 121 (1), pp. 91-96Suma, H., Horii, T., Isomura, T., Buckberg, G., A new concept of ventricular restoration for nonischemic dilated cardiomyopathy (2006) Eur J Cardiothorac Surg, 29 (SUPPL. 1), pp. S207-S212. , RESTORE GroupForm versus disease: Optimizing geometry during ventricular restoration (2006) Eur J Cardiothorac Surg, 29 (SUPPL. 1), pp. S238-S244. , RESTORE GroupKieser, T.M., The left ventricle: To reconstruct or not: Lessons from the STICH trial (2009) J Thorac Cardiovasc Surg, 138 (3), p. 784Suma, H., Isomura, T., Horii, T., Buckberg, G., Role of site selection for left ventriculoplasty to treat idiopathic dilated cardiomyopathy (2004) Heart Fail Rev, 9 (4), pp. 329-336. , RESTORE GroupDancini, J.L., Rodrigues, J.J., Santos, J.S., Pinto, R.F.A., Burgos, F.J.C., Conforti, C.A., Left ventricular aneurysmectomy: Late followup (1996) Rev Bras Cir Cardiovasc, 1 (11), pp. 23-29Almeida, R.M.S., Lima, J.D., Bastos, L.C., Carvalho, C.T., Loures, D.R., Endoventricular circular patch plasty with septal exclusion: Initial experience (2000) Rev Bras Cir Cardiovasc, 4 (15), pp. 302-307Campagnucci, V.P., Rivetti, L.A., Pinto e Silva, A.M.R., Gandra, S.M.A., Pereira, W.L., Aneurismectomia de ventrículo esquerdo com o coração batendo ininterruptamente: Resultados imediatos (2006) Rev Bras Cir Cardiovasc, 21 (1), pp. 55-61Herrera, C.B., Insalralde, A., Brandi, A.C., Santos, C.A., Herrera, D.D., Soares, M.J.F., Correção de aneurisma de ventrículo esquerdo em paciente chagásico empregando prótese de pericárdio bovino (2000) Rev Bras Cir Cardiovasc, 15 (1), pp. 72-74Sgarbi, C.J., Ardito, R.V., Santos, R.C., Bogdan, R.A.B., Arruda Jr., F.V., Silva, E.M., Correção cirúrgica do aneurisma de ventrículo esquerdo: Comparação entre as técnicas de sutura linear e reconstrução geométrica (2000) Rev Bras Cir Cardiovasc, 15 (4), pp. 293-301Versteegh, M.I., Lamb, H.J., Bax, J.J., Curiel, F.B., van der Wall, E.E., de Roos, A., MRI evaluation of left ventricular function in anterior LV aneurysms before and after surgical resection (2003) Eur J Cardiothorac Surg, 23 (4), pp. 609-613Use of cardiac magnetic resonance imaging in surgical ventricular restoration (2006) Eur J Cardiothorac Surg, 29 (SUPPL. 1), pp. S216-S224. , Buckberg GD;RESTORE GroupWalker, J.C., Guccione, J.M., Jiang, Y., Zhang, P., Wallace, A.W., Hsu, E.W., Helical myofiber orientation after myocardial infarction and left ventricular surgical restoration in sheep (2005) J Thorac Cardiovasc Surg, 129 (2), pp. 382-39

The emergence of the cortisol circadian rhythm in monozygotic and dizygotic twin infants: the twin-pair synchrony

OBJECTIVE: Studies on the influence of genetic factors on the ontogeny of cortisol circadian rhythm in infants are lacking. This study evaluated the influence of twinning and the heritability on the age of emergence of salivary cortisol rhythm. DESIGN AND SUBJECTS: A longitudinal study was performed using salivary samples obtained during morning and night, at 2, 4, 8, 12, 16, 20 and 24 weeks of postnatal life in 34 infants, 10 monozygotic (MZ) and 7 dizygotic (DZ) twin pairs. Salivary cortisol was determined by radioimmunoassay (RIA). Zigosity was verified by DNA analysis of at least 13 short tandem repeat polymorphisms. Difference of the emergence of cortisol circadian rhythm, within each twin pair, the intraclass correlation coefficient and the heritability index (h(2)) were calculated. RESULTS: The mean (± SEM) age of emergence of salivary cortisol circadian rhythm was similar in MZ and DZ (7·8 ± 1·0 vs 7·4 ± 1·3 weeks). Seven pairs showed coincidence of the emergence of cortisol rhythm. Ten pairs were not coincident; among them the within-pair difference of emergence of salivary circadian rhythm was similar in both MZ and DZ groups. The intraclass correlation coefficients were rMZ = 0·60, P = 0·02; and rDZ = 0·65, P = 0·03, respectively. The heritability index (h(2)) was 0·21 (ns). CONCLUSIONS: Salivary circadian rhythm appeared at the same postnatal age in MZ and DZ twin infants. Although several physiological aspects might be involved, the heritability index, obtained in the present study, suggests less genetic than environmental impact on the age of the onset of the cortisol circadian rhythm. Our data also indicated that each twin-pair show synchrony because they probably shared prenatal and postnatal environmental synchronizers

Early pair housing increases solid feed intake and weight gains in dairy calves

Dairy calves have traditionally been kept in individual pens throughout the milk-feeding period. Social rearing is associated with increased solid feed intake and hence higher weight gains before and after weaning. Little is known about the effect of the age at which social housing begins. The aim of this study was to assess the effects of early versus late pairing on feeding behavior and weight gain before and after weaning. Holstein bull calves were reared individually (n=8 calves), or paired with another calf at 6 ± 3 d (n=8 pairs) or 43 ± 3 d of age (n=8 pairs). All calves were fed 8 L of milk/d for 4 wk, 6 L/d from 4 to 7 wk and then milk was reduced by 20%/d until calves were completely weaned at 8 wk of age. Calves were provided ad libitum access to calf starter and a total mixed ration (TMR). Body weight and feed intake were measured weekly from 3 to 10 wk of age. Intake of calf starter was significantly higher for the early-paired calves than for individually-reared and late-paired calves throughout the experimental period. At 10 wk of age, starter dry matter intake (DMI) averaged 2.20 ± 0.22 kg/d, 1.09 ± 0.25 kg/d and 1.26 ± 0.33 kg/d for early pair, late pair and individually housed calves, respectively. Intake of TMR did not differ among treatments, TMR dry matter intake (averaged 3.27 ± 0.72 kg/d, 3.08 ± 0.46 kg/d, and 2.89 ± 0.54 kg/d for the same three treatments). Calves in the early pair treatment also showed significantly higher average daily gain (ADG) over the experimental period (0.89 ± 0.04 kg/d versus 0.76 ± 0.04 kg/d and 0.73 ± 0.04 kg/d for the early paired, individual and late-paired calves, respectively). These results indicate that social housing soon after birth can increase weight gains and intake of solid feed

Spectra of weighted algebras of holomorphic functions

We consider weighted algebras of holomorphic functions on a Banach space. We determine conditions on a family of weights that assure that the corresponding weighted space is an algebra or has polynomial Schauder decompositions. We study the spectra of weighted algebras and endow them with an analytic structure. We also deal with composition operators and algebra homomorphisms, in particular to investigate how their induced mappings act on the analytic structure of the spectrum. Moreover, a Banach-Stone type question is addressed.Comment: 25 pages Corrected typo

Stabilities of nanohydrated thymine radical cations: insights from multiphoton ionization experiments and ab initio calculations

Multi-photon ionization experiments have been carried out on thymine-water clusters in the gas phase. Metastable H2O loss from T+(H2O)n was observed at n ≥ 3 only. Ab initio quantum-chemical calculations of a large range of optimized T+(H2O)n conformers have been performed up to n = 4, enabling binding energies of water to be derived. These decrease smoothly with n, consistent with the general trend of increasing metastable H2O loss in the experimental data. The lowest-energy conformers of T+(H2O)3 and T+(H2O)4 feature intermolecular bonding via charge-dipole interactions, in contrast with the purely hydrogen-bonded neutrals. We found no evidence for a closed hydration shell at n = 4, also contrasting with studies of neutral clusters

Superconductivity in the SU(N) Anderson Lattice at U=\infty

We present a mean-field study of superconductivity in a generalized N-channel cubic Anderson lattice at U=\infty taking into account the effect of a nearest-neighbor attraction J. The condition U=\infty is implemented within the slave-boson formalism considering the slave bosons to be condensed. We consider the $f$-level occupancy ranging from the mixed valence regime to the Kondo limit and study the dependence of the critical temperature on the various model parameters for each of three possible Cooper pairing symmetries (extended s, d-wave and p-wave pairing) and find interesting crossovers. It is found that the d- and p- wave order parameters have, in general, very similar critical temperatures. The extended s-wave pairing seems to be relatively more stable for electronic densities per channel close to one and for large values of the superconducting interaction J.Comment: Seven Figures; one appendix. Accepted for publication in Phys. Rev.