The comparative landscape of duplications in Heliconius melpomene and Heliconius cydno.

Gene duplications can facilitate adaptation and may lead to interpopulation divergence, causing reproductive isolation. We used whole-genome resequencing data from 34 butterflies to detect duplications in two Heliconius species, Heliconius cydno and Heliconius melpomene. Taking advantage of three distinctive signals of duplication in short-read sequencing data, we identified 744 duplicated loci in H. cydno and H. melpomene and evaluated the accuracy of our approach using single-molecule sequencing. We have found that duplications overlap genes significantly less than expected at random in H. melpomene, consistent with the action of background selection against duplicates in functional regions of the genome. Duplicate loci that are highly differentiated between H. melpomene and H. cydno map to four different chromosomes. Four duplications were identified with a strong signal of divergent selection, including an odorant binding protein and another in close proximity with a known wing colour pattern locus that differs between the two species.

The diversification of Heliconius butterflies: what have we learned in 150 years?

Research into Heliconius butterflies has made a significant contribution to evolutionary biology. Here, we review our understanding of the diversification of these butterflies, covering recent advances and a vast foundation of earlier work. Whereas no single group of organisms can be sufficient for understanding life's diversity, after years of intensive study, research into Heliconius has addressed a wide variety of evolutionary questions. We first discuss evidence for widespread gene flow between Heliconius species and what this reveals about the nature of species. We then address the evolution and diversity of warning patterns, both as the target of selection and with respect to their underlying genetic basis. The identification of major genes involved in mimetic shifts, and homology at these loci between distantly related taxa, has revealed a surprising predictability in the genetic basis of evolution. In the final sections, we consider the evolution of warning patterns, and Heliconius diversity more generally, within a broader context of ecological and sexual selection. We consider how different traits and modes of selection can interact and influence the evolution of reproductive isolation.

Multi-locus interactions and the build-up of reproductive isolation.

All genes interact with other genes, and their additive effects and epistatic interactions affect an organism's phenotype and fitness. Recent theoretical and empirical work has advanced our understanding of the role of multi-locus interactions in speciation. However, relating different models to one another and to empirical observations is challenging. This review focuses on multi-locus interactions that lead to reproductive isolation (RI) through reduced hybrid fitness. We first review theoretical approaches and show how recent work incorporating a mechanistic understanding of multi-locus interactions recapitulates earlier models, but also makes novel predictions concerning the build-up of RI. These include high variance in the build-up rate of RI among taxa, the emergence of strong incompatibilities producing localized barriers to introgression, and an effect of population size on the build-up of RI. We then review recent experimental approaches to detect multi-locus interactions underlying RI using genomic data. We argue that future studies would benefit from overlapping methods like ancestry disequilibrium scans, genome scans of differentiation and analyses of hybrid gene expression. Finally, we highlight a need for further overlap between theoretical and empirical work, and approaches that predict what kind of patterns multi-locus interactions resulting in incompatibilities will leave in genome-wide polymorphism data. This article is part of the theme issue 'Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers'.

[Salt intake profile and blood pressure in cystic fibrosis]. / Perfil ingestivo salino y presión arterial en la fibrosis quística.

BACKGROUND: High blood pressure (BP) is not considered a problem in patients with cystic fibrosis (CF). The loss of sodium in these patients may affect their sensitivity to the taste of salt. OBJECTIVES: To study the BP in a group of patients with CF and to analyse their salt intake profile and the relationship with their BP levels. PATIENTS AND METHODS: Cross-sectional analytical study with control group. Index group: 20 subjects, 4-30 years old with diagnosis of CF. CONTROL GROUP: 73 healthy subjects. Physical examination, BP measurement and specific tests to determine the salt ingestion profile. RESULTS: Systolic BP (SBP) and diastolic BP (DBP) values were lower in the CF group. SBP: 99.63+/-9.11mmHg vs. 111.94+/-10.71mmHg, P: 0.001. DBP: 57.84+/-7.40mmHg vs. 70.05+/-8.11mmHg, P: 0.001. When these values were adjusted for age, sex, weight and height of the participants, differences did not remain statistically significant. Values of the salt intake profile did not differ significantly between the two groups. While the control group showed a significant negative correlation between SBP and salt taste sensitivity (r: -0.341, P=0.003), this correlation was not confirmed in CF patients (r: -0.115 P=0.6). CONCLUSIONS: BP values and the salt intake profile values in CF patients are equivalent to the normal population values when their differences are adjusted to the potential confounding factors. There is no correlation between BP levels and salt taste sensitivity in patients with CF.

Lethal complication from insertion of nasogastric tube after severe basilar skull fracture.

An unusual complication is presented arising from the use of a nasogastric tube in a patient with a massive basilar skull fracture. Intracranial passage of the NG tube resulted. Therefore, in the presence of a severe basilar fracture and/or significant maxillofacial trauma where the integrity of the base of the skull may be in question, one should be very hesitant to insert tubes into the nasopharynx.

Sphincteric stent versus external sphincterotomy in spinal cord injured men: prospective randomized multicenter trial.

PURPOSE: In a prospective randomized multicenter trial we compared the treatment results of conventional external sphincterotomy with those of UroLume sphincteric stent prosthesis placement in men with spinal cord injury and external detrusor-sphincter dyssynergia. MATERIALS AND METHODS: We randomized 57 men with spinal cord injury in whom urodynamics verified external detrusor-sphincter dyssynergia into 2 groups to undergo either sphincter defeating procedure. We compared the primary urodynamic parameter of maximum detrusor pressure, and secondary urodynamic parameters of bladder capacity and post-void residual urine volume in men who underwent sphincterotomy or sphincteric stent placement. Parameters were measured preoperatively, and 3, 6, 12 and 24 months postoperatively. Patients completed questionnaires regarding voiding sensation and quality of life issues at each followup visit. RESULTS: Demographic data of the 26 patients treated with sphincterotomy and the 31 treated with sphincteric stent placement were statistically similar. Preoperatively mean maximum detrusor pressure plus or minus standard deviation in sphincterotomy and stent cases was 98.3 +/- 27.6 and 95.7 +/- 27.7 cm. water, respectively (p = 0.73). At 12 months mean maximum detrusor pressure decreased to 48.9 +/- 16.4 and 52.6 +/- 31.6 cm. water in the sphincterotomy and stent groups, respectively (p = 0). Preoperatively mean bladder capacity in sphincterotomy and stent cases was 245 +/- 158 and 251 +/- 145 ml., respectively (p = 0.87). Bladder capacity did not change significantly in either treatment group throughout followup. Preoperatively mean post-void residual urine volume in the sphincterotomy and stent groups was 212 +/- 163 and 168 +/- 114 ml., respectively (p = 0.33). Residual urine volume decreased in each group at some but not all followup evaluations. The duration of hospitalization was greater for sphincterotomy than stenting (p = 0.036). Six stents required explantation. CONCLUSIONS: The UroLume stent is as effective as conventional external sphincterotomy for treating external detrusor-sphincter dyssynergia. However, sphincteric stent placement is advantageous because it involves shorter hospitalization and is potentially reversible.

Perfil ingestivo salino y presión arterial en la fibrosis quística / Salt intake profile and blood pressure in cystic fibrosis

Introducción: La hipertensión arterial no se ha considerado un problema en el seguimiento de los pacientes con fibrosis quística (FQ). Las pérdidas de sodio en estos pacientes condicionan deshidrataciones hiponatrémicas que pueden repercutir en su sensibilidad gustativa a la sal. Objetivo: Estudiar los valores de presión arterial (PA) y analizar el perfil ingestivo salino y su relación con la PA en un grupo de pacientes con FQ. Pacientes y métodos: Estudio transversal analítico con un grupo control: grupo de estudio de 20 sujetos de 4 a 30 años con diagnóstico de FQ y grupo control de 73 sujetos sanos. Realización de examen físico, medición de PA y test específicos para determinar el perfil ingestivo salino. Resultados: Los valores de PA sistólica (PAS) y de PA diastólica (PAD) fueron significativamente menores en el grupo de pacientes con FQ (PAS de 99,63±9,11mmHg frente a 111,94±10,71mmHg, p=0,001; PAD de 57,84±7,40mmHg frente a 70,05±8,11mmHg, p=0,001). Al ajustar estos valores por edad, sexo, peso y talla, las diferencias no mantuvieron significación estadística. Los valores del estudio del perfil ingestivo salino no presentaron diferencias significativas entre ambos grupos. Mientras que el grupo control presentó una correlación negativa entre la PAS y la sensibilidad gustativa a la sal (coeficiente de correlación de Pearson [r] de −0,341; p=0,003), en el grupo de pacientes con FQ esta relación no se confirmó (r de −0,115; p=0,6). Conclusiones: Los valores de PA y los valores de estudio del perfil ingestivo salino de los pacientes con FQ son equivalentes a los valores de la población normal cuando se ajustan sus diferencias por los posibles factores de confusión. No hay correlación entre los valores de PA y la sensibilidad gustativa a la sal en los pacientes con FQ (AU)

Background: High blood pressure (BP) is not considered a problem in patients with cystic fibrosis (CF). The loss of sodium in these patients may affect their sensitivity to the taste of salt. Objectives: To study the BP in a group of patients with CF and to analyse their salt intake profile and the relationship with their BP levels. Patients and methods: Cross-sectional analytical study with control group. Index group: 20 subjects, 4–30 years old with diagnosis of CF. Control group: 73 healthy subjects. Physical examination, BP measurement and specific tests to determine the salt ingestion profile. Results: Systolic BP (SBP) and diastolic BP (DBP) values were lower in the CF group. SBP: 99.63±9.11mmHg vs. 111.94±10.71mmHg, P: 0.001. DBP: 57.84±7.40mmHg vs. 70.05±8.11mmHg, P: 0.001. When these values were adjusted for age, sex, weight and height of the participants, differences did not remain statistically significant. Values of the salt intake profile did not differ significantly between the two groups. While the control group showed a significant negative correlation between SBP and salt taste sensitivity (r: −0.341, P=0.003), this correlation was not confirmed in CF patients (r: −0.115 P=0.6). Conclusions: BP values and the salt intake profile values in CF patients are equivalent to the normal population values when their differences are adjusted to the potential confounding factors. There is no correlation between BP levels and salt taste sensitivity in patients with CF (AU)