Progression of diffuse esophageal spasm to achalasia: incidence and predictive factors.

The progression of certain primary esophageal motor disorders to achalasia has been documented; however, the true incidence of this decay is still elusive. This study aims to evaluate: (i) the incidence of the progression of diffuse esophageal spasm to achalasia, and (ii) predictive factors to this progression. Thirty-five patients (mean age 53 years, 80% females) with a manometric picture of diffuse esophageal spasm were followed for at least 1 year. Patients with gastroesophageal reflux disease confirmed by pH monitoring or systemic diseases that may affect esophageal motility were excluded. Esophageal manometry was repeated in all patients. Five (14%) of the patients progressed to achalasia at a mean follow-up of 2.1 (range 1-4) years. Demographic characteristics were not predictive of transition to achalasia, while dysphagia (P= 0.005) as the main symptom and the wave amplitude of simultaneous waves less than 50 mmHg (P= 0.003) were statistically significant. In conclusion, the transition of diffuse esophageal spasm to achalasia is not frequent at a 2-year follow-up. Dysphagia and simultaneous waves with low amplitude are predictive factors for this degeneration.

Spontaneous rupture of a giant hepatic hemangioma. Sequential treatment with preoperative transcatheter arterial embolization and conservative hepatectomy.

Hemangioma is the most common benign tumor of the liver and it is often asymptomatic. Spontaneous rupture of liver hemangiomas is a rare but potentially lethal complication. Emergent hepatic resection has been the treatment of choice but carries high operative morbidity and mortality. Recently, preoperative transcatheter arterial embolization (TAE) has been used successfully for the management of bleeding ruptured liver tumors and non-operative treatment of symptomatic giant liver hemangiomas. We report a case of spontaneous rupture of a giant hepatic hemangioma that presented with thoracic and abdominal pain and shock due to hemoperitoneum. Once proper diagnosis was made the patient was successfully managed by TAE, followed by conservative hepatic resection.

Mechanism of 1,4,5,8-naphthalene tetracarboxylic acid dianhydride hydrolysis and formation in aqueous solution.

The study of highly conjugated, carbonyl-containing molecules such as 1,4,5,8-naphthalene tetracarboxylic dianhydride, III, is of interest since reactivity differences and transmission of electronic effects through the conjugated framework can be evidenced. The kinetics of hydrolysis of III in aqueous solution were determined from 5 M acid to pH 10. In basic solution hydrolysis of III yields, sequentially, 1,4,5,8-naphthalene diacid monoanhydride, II, and 1,4,5,8-naphthalene tetracarboxylic acid, I. The second order rate constant for alkaline hydrolysis is 200 fold higher for the first ring opening. The water-catalyzed hydrolysis of III yields a pH-dependent mixture of ionic forms of I and II. The rate constant for water-catalyzed hydrolysis of III is 25 fold higher than that for II. In concentrated acid the rates for reaching equilibrium (I, II and III) increase and III is the major product. The pK(a)s of I (3.24, 5.13 and 6.25) and II (3.05, 5.90) were determined by potentiometric, fluorescence and UV spectroscopy titrations and by quantitative fit of the kinetic and equilibrium data. The apparent, pH-dependent, equilibrium constants, K(EqII), for anhydride formation between I and II were obtained from the UV spectra. The quantitative fit of kinetic and equilibrium data are consistent with the assumption that anhydride formation only proceeds with the fully protonated species for both I and II and permitted the estimation of the equilibrium constants for anhydride formation, K(EqII). The value of K(EqII) (I <==> II) between pH 1 and 6 was ca. 5. Geometry optimization calculations in the gas phase of the reactions of III in alkaline, neutral and acid conditions, at the DFT level of theory, gave electronic distributions that were qualitatively consistent with the experimental results.

Predicting hydration free energies of neutral compounds by a parametrization of the polarizable continuum model.

A parametrization of the polarizable continuum model (PCM) is presented having the experimental hydration free energies of 215 neutral molecules as target. The cavitation and dispersion contributions were based on the Tuñon-Silla-Pascual-Ahuir (Tuñon; et al. Chem. Phys. Lett. 1993, 203, 289) and Floris-Tomasi (Floris, F.; Tomasi, J. J. Comput. Chem. 1989, 10, 616) expressions, respectively. Both the polar and nonpolar contributions were evaluated on the same solvent-excluding molecular surface that used unscaled Bondi atomic radii. The parametrization was provided for the HF, Xalpha, LSDA, B3LYP, and mPW1PW91 methods at the 6-31G(d) basis set, and the results are in fair agreement with the experimental data. For the sake of comparison, the PCM(UAHF) and our parametrization (PCM2), both at HF level, have produced DeltaG(PCM(UAHF)) = aDeltaGexp (a = 1.02 +/- 0.02, r = 0.945, sd = 0.987, Ftest = 1778) and DeltaG(PCM2) = aDeltaGexp (a = 0.95 +/- 0.02, r = 0.952, sd = 0.843, Ftest = 2070), respectively. The mean absolute deviations from experimental data were 0.67 and 0.68 kcal/mol for PCM(UAHF) and PCM2, respectively.

Acción de los cambios hormonales sobre los valores hematimétricos, hemostasia, coagulación y fibrinolisis / Intervention of the hormonal changes in hematimetric hemostatic, coagulation and fibrinolysis values

Determinamos la acción de los cambios hormonales, progesterona y estrogeno sobre la hematopoyesis, hemostasia, coagulacion y fibrinolisis, en mujeres nativas de la altura. Se estudio 50 casos, con se respectiva ficha clinica, antes y despues de ciclo menstrual. Se correlacionaron factores geneticos (Grupos, sanguineos: A, B, O). Los sujetos del grupo O y AB, mostraron disminucion significativa de sus reticulocitos (p<0.001). En cambio, los del grupo A y B, aumentaron el numero de estas celulas (p<0.001). Ademas en el grupo sanguineo O, se observo que hacen uso de las reservas de Fe (Protoporfirina), a diferencia de los otros grupos. Referente a la hemostasia, el estudio cuantitativo y cualitativo (numeracion, agragacion y fragilidad capilar), mostraron una disminucion significativa (p<0.05 - p<0.001). En la coagulacion se observo una disminucion significativa en cuanto a la actividad protrombinica y del tiempo de tromboplastina parcial, (p<0.005 y 0.0001). Esto expliacria los sangrados menstruales prolongados y abundantes. Finalmente, la fibrinolisis tuvo valores superiores a 3 horas, en relacion a os valores normales (12 hrs. 30 min). De este trabajo concluimos, que los factores geneticos influyen en la Eritropoyesis, la Hemostasia, Coagulación y Fribrinolisis, en los sujetos de la altura, lo que nos permitira continuar estos estudios, referentes a la Eritrocitosis de nuestro medio.

Sistema adrenérgico en los residentes de grandes alturas / Adrenergic system at high altitude population

Heart rate (FC) response to perfusion with isoprenaline is decreased in sealevel natives on expuser to high altitude hypoxia. Since noredraline concentration in plasma is elevated under these condition as phenomenon of downregulation of the betareceptors (BAR) cuold be evoked. For the fisrt time, this aspect was explored in a population native from and residing at 3600 m consisting of normocythemics (HAN) and polycythemics (HAP). the results were compared to those obtained from a sealevel population, exmined in normoxia (SLN) at 4800 m (J. Appl. Physiol. 65:1975-61, 1988). The dose necessary to increase FC by 25 beats per min (125) was identical for HAN and HAP as well as SLN. This iondicates that the chronotropic responses is igual in the two populations when they are studied in their habitual environment; to the contrary, this response is diminished in SLH, thus correlating to the phenomenon of downregulation.