Routine botulinum toxin injection one month after a Swenson pull-through does not change the incidence of Hirschsprung associated enterocolitis.

PURPOSE: Patients with Hirschsprung disease (HD) are at risk of Hirschsprung associated enterocolitis (HAEC) following pull-through. The purpose of this study was to determine if routine Botulinum toxin (BT) injected one-month post pull-through decreases the incidence of HAEC. METHODS: We reviewed patients who underwent a primary (not redo) pull-through operation for HD between April 2014 to December 2019. Over the most recent 18 months, BT was administered routinely one-month post-pull-through procedure; these patients were compared to the prior group that did not receive routine BT. A HAEC episode was defined as one that required initiation of treatment for obstructive symptoms in the inpatient or outpatient setting with antibiotics and irrigations. Categorical variables were compared using the nonparametric chi-square test or Fisher's exact test. Continuous variables were compared using the two-tailed Student's t-test. P-value <0.05 was determined to be statistically significant. RESULTS: A total of 70 patients underwent Swenson pull-through during the study period (52% male). There were no statistically significant differences in demographics in the BT vs. non-BT group. Routine post-pull-through BT was given in 28 patients and did not significantly change HAEC incidence compared to the non-BT group (12/28, 43% vs. 16/42, 38%. P = 0.691). Of note, the BT group patients developed HAEC significantly sooner than the patients in the non-BT group (37.5 days vs. 253 days, p = 0.029). More patients in the BT group (n = 18, 64%) required at least one subsequent BT injection compared to the patients in the non-BT group (n = 11, 26%. P = 0.001). CONCLUSIONS: We conclude that routine postoperative botulinum toxin injection given one month postoperatively from Swenson pull-through did not change the incidence of HAEC. A prospective controlled study is necessary to confirm these findings.

The Association of Enhanced Recovery Pathway and Acute Kidney Injury in Patients Undergoing Colorectal Surgery.

BACKGROUND: Acute kidney injury is associated with increased postoperative length of hospital stay and increases the risk of postoperative mortality. The association between the development of postoperative acute kidney injury and the implementation of an enhanced recovery after surgery protocol remains unclear. OBJECTIVE: This study aimed to examine the relationship between the implementation of an enhanced recovery pathway and the development of postoperative acute kidney injury. DESIGN: In this retrospective cohort study, a prospectively maintained database of patients who underwent elective colorectal surgery in an enhanced recovery pathway were compared to a hospital historical National Surgical Quality Improvement Program colorectal registry of patients. SETTINGS: This study was conducted at the University of Alabama at Birmingham, a tertiary referral center. PATIENTS: A total of 1052 patients undergoing elective colorectal surgery from 2012 through 2016 were included. MAIN OUTCOME MEASURES: The development of postoperative acute kidney injury was the primary outcome measured. RESULTS: Patients undergoing an enhanced recovery pathway had significantly greater rates of postoperative acute kidney injury than patients not undergoing an enhanced recovery pathway (13.64% vs 7.08%; p < 0.01). Our adjusted model indicated that patients who underwent an enhanced recovery pathway (OR, 2.31; 95% CI, 1.48-3.59; p < 0.01) had an increased risk of acute kidney injury. Patients who developed acute kidney injury in the enhanced recovery cohort had a significantly longer median length of stay than those who did not (median 4 (interquartile range, 4-9) vs 3 (interquartile range, 2-5) days; p=0.04). LIMITATIONS: This study did not utilize urine output as a modality for detecting acute kidney injury. Data are limited to a sample of patients from a large academic medical center participating in the National Surgical Quality Improvement Program. Interventions or programs in place at our institution that aimed at infection reduction or other initiatives with the goal of improving quality were not accounted for in this study. CONCLUSION: The implementation of an enhanced recovery after surgery protocol is independently associated with the development of postoperative acute kidney injury.See Video Abstract at http://links.lww.com/DCR/B69. LA ASOCIACIÓN DE VÍA DE RECUPERACIÓN MEJORADA Y LESIÓN RENAL AGUDA EN PACIENTES DE CIRUGÍA COLORRECTAL: La lesión renal aguda se asocia con una mayor duración en la estancia hospitalaria y aumenta el riesgo de la mortalidad postoperatoria. La asociación entre el desarrollo de la lesión renal aguda postoperatoria y la implementación de un protocolo de Recuperación Mejorada después de la cirugía, sigue sin ser clara.Examinar la relación entre la implementación de una vía de Recuperación Mejorada y el desarrollo de lesión renal aguda postoperatoria.Estudio de cohorte retrospectivo, de una base de datos mantenida prospectivamente, de pacientes que se sometieron a cirugía colorrectal electiva, en una vía de Recuperación Mejorada, se comparó con el registro histórico de los pacientes colorrectales del Programa Nacional de Mejora de la Calidad Quirúrgica.Universidad de Alabama en Birmingham, un centro de referencia terciario.Un total de 1052 pacientes sometidos a cirugía colorrectal electiva desde 2012 hasta 2016.Desarrollo de lesión renal aguda postoperatoria.Los pacientes sometidos a una vía de Recuperación Mejorada, tuvieron tasas significativamente mayores de lesiones renales agudas postoperatorias, en comparación con los pacientes de Recuperación no Mejorada (13.64% vs 7.08%; p < 0.01). Nuestro modelo ajustado indicó que los pacientes que se sometieron a una vía de Recuperación Mejorada (OR, 2.31; IC, 1.48-3.59; p < 0.01) tuvieron un mayor riesgo de lesión renal aguda. Los pacientes que desarrollaron daño renal agudo en la cohorte de Recuperación Mejorada, tuvieron una estadía mediana significativamente más larga en comparación con aquellos que no [mediana 4 (rango intercuartil (RIC) 4-9) versus 3 (RIC 2-5) días; p = 0.04].Este estudio no utilizó la producción de orina como una modalidad para detectar daño renal agudo. Los datos se limitan a una muestra de pacientes de un gran centro médico académico, que participa en el Programa Nacional de Mejora de la Calidad Quirúrgica. Las intervenciones o programas implementados en nuestra institución, destinados a la reducción de infecciones u otras iniciativas, con el objetivo de mejorar la calidad, no se tomaron en cuenta para este estudio.La implementación de una Recuperación Mejorada después del protocolo de cirugía, se asocia independientemente con el desarrollo de lesión renal aguda postoperatoria.Consulte Video Resumen en http://links.lww.com/DCR/B69. (Traducción-Dr. Fidel Ruiz-Healy).

An iron-oxygen intermediate formed during the catalytic cycle of cysteine dioxygenase.

Cysteine dioxygenase is a key enzyme in the breakdown of cysteine, but its mechanism remains controversial. A combination of spectroscopic and computational studies provides the first evidence of a short-lived intermediate in the catalytic cycle. The intermediate decays within 20 ms and has absorption maxima at 500 and 640 nm.

An investigation of bubble coalescence and post-rupture oscillation in non-ionic surfactant solutions using high-speed cinematography.

Most processes involving bubbling in a liquid require small bubbles to maximise mass/energy transfer. A common method to prevent bubbles from coalescing is by the addition of surfactants. In order to get an insight into the coalescence process, capillary bubbles were observed using a high speed cinematography. Experiments were performed in solutions of 1-pentanol, 4-methyl-2-pentanol, tri(propylene glycol) methyl ether, and poly(propylene glycol) for which information such as the coalescence time and the deformation of the resultant bubble upon coalescence was extracted. It is shown in this study that the coalescence time increases with surfactant concentration until the appearance of a plateau. The increase in coalescence time with surfactant concentration could not be attributed only to surface elasticity. The oscillation of the resultant bubble was characterised by the damping of the oscillation. The results suggested that a minimum elasticity is required to achieve an increased damping and considerable diffusion has a detrimental effect on the dynamic response of the bubble, thereby reducing the damping.

Chlorine dioxide oxidation of dihydronicotinamide adenine dinucleotide (NADH).

The oxidation of dihydronicotinamide adenine dinucleotide (NADH) by chlorine dioxide in phosphate buffered solutions (pH 6-8) is very rapid with a second-order rate constant of 3.9 x 10(6) M(-1) s(-1) at 24.6 degrees C. The overall reaction stoichiometry is 2ClO2(*) per NADH. In contrast to many oxidants where NADH reacts by hydride transfer, the proposed mechanism is a rate-limiting transfer of an electron from NADH to ClO2(*). Subsequent sequential fast reactions with H(+) transfer to H2O and transfer of an electron to a second ClO2(*) give 2ClO2(-), H3O(+), and NAD(+) as products. The electrode potential of 0.936 V for the ClO2(*)/ClO2(-) couple is so large that even 0.1 M of added ClO2(-) (a 10(3) excess over the initial ClO2(*) concentration) fails to suppress the reaction rate.

Molecular analysis of two cytochrome P450 monooxygenase genes required for paxilline biosynthesis in Penicillium paxilli, and effects of paxilline intermediates on mammalian maxi-K ion channels.

The gene cluster required for paxilline biosynthesis in Penicillium paxilli contains two cytochrome P450 monooxygenase genes, paxP and paxQ. The primary sequences of both proteins are very similar to those of proposed cytochrome P450 monooxygenases from other filamentous fungi, and contain several conserved motifs, including that for a haem-binding site. Alignment of these sequences with mammalian and bacterial P450 enzymes of known 3-D structure predicts that there is also considerable conservation at the level of secondary structure. Deletion of paxP and paxQ results in mutant strains that accumulate paspaline and 13-desoxypaxilline, respectively. These results confirm that paxP and paxQ are essential for paxilline biosynthesis and that paspaline and 13-desoxypaxilline are the most likely substrates for the corresponding enzymes. Chemical complementation of paxilline biosynthesis in paxG (geranygeranyl diphosphate synthase) and paxP, but not paxQ, mutants by the external addition of 13-desoxypaxilline confirms that PaxG and PaxP precede PaxQ, and are functionally part of the same biosynthetic pathway. A pathway for the biosynthesis of paxilline is proposed on the basis of these and earlier results. Electrophysiological experiments demonstrated that 13-desoxypaxilline is a weak inhibitor of mammalian maxi-K channels (Ki=730 nM) compared to paxilline (Ki=30 nM), indicating that the C-13 OH group of paxilline is crucial for the biological activity of this tremorgenic mycotoxin. Paspaline is essentially inactive as a channel blocker, causing only slight inhibition at concentrations up to 1 microM.

Viscosity effect on the structural compactness of latex flocs formed under weak depletion attractions.

Dilute aqueous dispersions of colloidal polystyrene latex spheres were flocculated by adding a nonadsorbing polymer sample, poly(acrylic acid). The structural compactness of the flocs thus formed was characterized in terms of their mass fractal dimension using the small-angle static light scattering technique. It was found that with low poly(acrylic acid) concentrations and thus weak depletion attraction forces, the dispersion medium viscosity had a marked effect on the floc structure. An increase in the viscosity led to formation of denser flocs. This was revealed in three sets of depletion flocculation experiments: (a) adjusting the background electrolyte concentration at a fixed level of poly(acrylic acid), (b) using water and 30% (w/w) glycerol as the respective solvents, and (c) inducing latex flocculation with two poly(acrylic acids) of different molecular weights at the respective critical polyacid concentrations. Direct force measurements were made with atomic force microscopy to isolate the influence of viscosity on floc structure from that of interparticle interaction energies. We conclude that the formation of denser flocs with increasing medium viscosity can be attributed to the reduced diffusivity of particles in the solution. The latter resulted in an enhanced rate of floc restructuring (through relaxation of attached particles) relative to floc growth.

Substrate deactivation of phenylalanine-sensitive 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase by erythrose 4-phosphate.

3-Deoxy-D-arabino-heptulosonate 7-phosphate synthase (DAH7PS, EC 4.1.2.15) catalyzes the condensation of phosphoenolpyruvate (PEP) with erythrose 4-phosphate (E4P) to give DAH7P via an ordered sequential mechanism. In the absence of PEP (the first substrate to bind), E4P binds covalently to the phenylalanine-sensitive DAH7PS of Escherichia coli, DAH7PS(Phe), deactivating the enzyme. Activity is restored on addition of excess PEP but not if deactivation was carried out in the presence of sodium cyanoborohydride. Electrospray mass spectrometry indicates that a single E4P is bound to the protein. These data are consistent with a slow, reversible Schiff base reaction of the aldehydic functionality of E4P with a buried lysine. Molecular modeling indicates that Lys186, a residue at the base of the substrate-binding cavity involved in hydrogen bonding with PEP, is well placed to react with E4P forming an imine linkage that is substantially protected from solvent water.

Superimposed saddle and ruffled distortions of the porphyrin in iodo(pyridine-N)(5,10,15,20-tetraphenylporphyrinato-kappa(4)N)rhodium(III) toluene solvate.

In the title compound, [RhI(C(44)H(28)N(4))(C(5)H(5)N)].C(7)H(8), the porphyrin ring experiences significant distortion from planarity (a saddle conformation with a superimposed ruffling), as a result of steric interactions with the 2,6-H atoms of the axial pyridine ligand. This also leads to a slight lengthening of the Rh-pyridine bond [Rh-N 2.102 (7) A] relative to those seen in other pyridine adducts of six-coordinate Rh(III). The metric parameters of the porphyrin core are comparable with those of related metalloporphyrin derivatives. No significant intermolecular interactions are observed between the metalloporphyrin and disordered solvate species.