Aquagenic Keratoderma: Treatment Update. / La queratodermia acuagénica: actualización terapéutica.

Aquagenic keratoderma is an uncommon acquired dermatosis characterized by edema and whitish-translucent papules triggered by immersion or contact with water. Cases have been described in association with certain medications, hyperhidrosis, and cystic fibrosis. The aim of this review is to evaluate the effectiveness of different treatments for aquagenic keratoderma. We reviewed the literature and analyzed treatments for aquagenic keratoderma described in case series and reports. Aquagenic keratoderma associated with hyperhidrosis can be treated effectively. Tap water iontophoresis, endoscopic thoracic sympathectomy, botulinum toxin injections, and oxybutynin are effective against refractory forms. Topical salicylic acid and aluminum salts are effective, but of little value as maintenance therapy. Oral oxybutynin 5 mg/d is probably the best option for treating aquagenic keratoderma. The reported pathophysiological effects of nonsteroidal anti inflammatory drugs in this setting suggest that the use of prostaglandins might be justified. Additional studies are needed to investigate these hypotheses and resolve other questions.

Dynamics of Fattening and Thinning 2D Sessile Droplets.

We investigate the dynamics of a droplet on a planar substrate as the droplet volume changes dynamically due to liquid being pumped in or out through a pore. We adopt a diffuse-interface formulation which is appropriately modified to account for a localized inflow-outflow boundary condition (the pore) at the bottom of the droplet, hence allowing to dynamically control its volume, as the droplet moves on a flat substrate with a periodic chemical pattern. We find that the droplet undergoes a stick-slip motion as the volume is increased (fattening droplet) which can be monitored by tracking the droplet contact points. If we then switch over to outflow conditions (thinning droplet), the droplet follows a different path (i.e., the distance of the droplet midpoint from the pore location evolves differently), giving rise to a hysteretic behavior. By means of geometrical arguments, we are able to theoretically construct the full bifurcation diagram of the droplet equilibria (positions and droplet shapes) as the droplet volume is changed, finding excellent agreement with time-dependent computations of our diffuse-interface model.

Characterization and treatment of enuresis in overactive bladder patients. / Caracterización y tratamiento de la enuresis en pacientes con vejiga hiperactiva.

OBJECTIVE: To define the types of overactive bladder (OAB) patient enuresis and study daytime bladder treatment response. MATERIALS AND METHODS: A prospective, multi-center study of OAB patients with enuresis treated with anticholinergics or neuromodulation over 3 months from 2019 to 2021 was carried out. Variables achieved from the voiding calendar and PLUTSS (Pediatric Lower Urinary Tract Score System), as well as enuresis-related variables, were collected. Two study groups were created -primary enuresis (PE) and secondary enuresis (SE). Partial enuretic response (PER) was defined as a > 50% reduction in baseline enuresis, and complete enuretic response (CER) as a 100% reduction. A multivariate analysis was eventually conducted to detect CER independent predictive factors. RESULTS: 152 OAB patients were included. 109 of them (71.7%) had enuresis -29 (26.7%) SE and 80 (73.3%) PE. PLUTSS score was higher in PE patients than in SE patients (20.8 vs. 17.2; p= 0.001). PER and CER were significantly higher in the SE group (55.2% vs. 15%; p= 0.000 in PER, and 48.3% vs. 5%; p= 0.000 in CER). In the multivariate analysis, SE patients demonstrated to have a 50-fold increased probability of responding to daytime bladder treatment than PE patients (OR: 49.79; 95%CI: 6.73-36.8). CONCLUSIONS: Most OAB children have PE and not SE, which explains why enuresis does not typically respond to daytime bladder treatment. Characterizing the type of enuresis in OAB children is important to adequately approach treatment.

OBJETIVOS: Definir los tipos de enuresis de los pacientes con vejiga hiperactiva (VH) y estudiar su respuesta al tratamiento vesical diurno. MATERIAL Y METODOS: Estudio prospectivo y multicéntrico: pacientes con VH y enuresis, tratados con anticolinérgicos o neuromodulación durante 3 meses (2019-2021). Recogimos variables obtenidas del calendario miccional, cuestionario PLUTSS (Pediatric Lower Urinary Tract Score System), y relacionadas con la enuresis. Generamos 2 grupos de estudio: enuresis primaria (EP) y enuresis secundaria (ES). Consideramos respuesta parcial enurética (RPE) a la reducción del valor de enuresis inicial en más de un 50% y respuesta completa (RCE) el 100%. Finalmente realizamos un análisis multivariante para detectar factores predictivos independientes de RCE. RESULTADOS: Incluimos 152 pacientes con VH, 109 de los cuales presentaban enuresis (71,7%): 29 ES (26,7%) y 80 EP (73,3%). El valor PLUTSS fue mayor en pacientes con EP que en ES (20,8 vs. 17,2, p= 0,001.) La RPE y la RCE fueron significativamente mayores en el grupo de ES (55,2% vs. 15%, p= 0,000 en RPE y 48,3% vs. 5%, p= 0,000 en RCE). En el análisis multivariante se identificó que los pacientes con ES tienen una probabilidad de responder al tratamiento vesical diurno 50 veces superior que los pacientes con EP (OR 49,79, IC95% 6,73-36,8). CONCLUSIONES: La mayoría de niños con VH tienen una EP y no secundaria, por lo que generalmente la enuresis de estos pacientes no responde al tratamiento vesical diurno. Es importante caracterizar el tipo de enuresis de los niños con VH para plantear su tratamiento de forma adecuada.

New stochastic mode reduction strategy for dissipative systems.

We present a new methodology for studying non-Hamiltonian nonlinear systems based on an information theoretical extension of a renormalization group technique using a modified maximum entropy principle. We obtain a rigorous dimensionally reduced description for such systems. The neglected degrees of freedom by this reduction are replaced by a systematically defined stochastic process under a constraint on the second moment. This then forms the basis of a computationally efficient method. Numerical computations for the generalized Kuramoto-Sivashinsky equation support our method and reveal that the long-time underlying stochastic process of the fast (unresolved) modes obeys a universal distribution that does not depend on the initial conditions and which we rigorously derive by the maximum entropy principle.

Hyaluronic acid-silica nanohybrid gels.

Excessive water sorption and low mechanical properties are a severe drawback in some biomedical applications of hyaluronic acid (HA). A way to improve these properties is here explored through the novel concept of nanohybrid hydrogels consisting of a HA matrix including different amounts of silica-derived species. This inorganic filler phase controls the mechanical and swelling properties of HA cross-linked matrices. Below a 2 wt % of silica in the systems, nanoparticle aggregates of tens of nanometers and silica oligomers are distributed more or less homogeneously throughout the organic matrix, without percolating. This morphology of the silica phase is accompanied by an increased swelling degree of the composite when compared with pure HA. For higher silica mass ratios in the composites the inorganic counterpart coalesces, leading to a continuous inorganic silica network interpenetrated with the organic HA network, which coexists with a dispersed phase of silica-nanoparticle aggregates. Silica oligomers originating in the exposition of the nanoparticles to reactives during the composite preparation procedure contribute to the continuity of the silica network. For these compositions, swelling is reduced three times when compared with pure HA, and a significant improvement of the mechanical properties occurs. Water-containing samples of these materials exhibited a glass transition, which pure dry HA does not. None of the compositions studied showed any cytotoxicity. Thus, the materials could be of use in tissue engineering applications where these properties of HA need to be modulated.

Efficacy of sacral transcutaneous electrical nerve stimulation in patients with overactive bladder refractory to anticholinergic treatment: a prospective multi-center study. / Eficacia de la electroestimulación transcutánea sacra en pacientes con vejiga hiperactiva refractarios a fármacos anticolinérgicos. Estudio prospectivo y multicéntrico.

OBJECTIVE: To determine whether sacral transcutaneous electrical nerve stimulation (S-TENS) is an effective treatment in patients refractory to anticholinergic drugs (Achs). MATERIALS AND METHODS: A prospective multi-center study of patients with overactive bladder (OB) refractory to Achs treated with S-TENS from 2018 to 2021 was carried out. S-TENS was applied over 3 months. Symptom progression was assessed using the voiding calendar and the Pediatric Lower Urinary Tract Symptoms Score (PLUTSS), excluding questions 3 and 4 -referring to enuresis- so that progression of daytime symptoms only (LUTS variable) was analyzed. RESULTS: 66 patients -50% of whom were female- were included, with a mean age of 9.5 years (range: 5-15). S-TENS significantly lowered PLUTSS (19.1 baseline vs. 9.5 final, p< 0.001) and LUTS (13.1 baseline vs. 4.8 final, p< 0.001). It also reduced the number of mictions (8.5 baseline vs. 6.4 final, p< 0.001), while increasing urine volume in the voiding records (214 ml baseline vs. 258 ml final, p< 0.001). Enuresis was the only variable refractory to S-TENS. Complication rate was 3% (2 patients with dermatitis in the S-TENS application area). CONCLUSIONS: S-TENS is effective and safe in the short-term in patients with OB refractory to Achs. Further studies assessing long-term efficacy and potential relapses are required.

OBJETIVOS: Determinar si la electroterapia nerviosa transcutánea a nivel sacro (TENS-S) es un tratamiento efectivo en pacientes refractarios a fármacos anticolinérgicos (Ach). MATERIAL Y METODOS: Estudio prospectivo y multicéntrico: pacientes con VH refractaria a Ach tratados con TENS-S entre 2018-2021. El TENS-S se aplicó durante 3 meses. La evolución sintomática fue evaluada utilizando el calendario miccional y el cuestionario PLUTSS (Pediatric Lower Urinary Tract Symptoms Score), pero excluyendo sus preguntas 3 y 4 (referidas a la enuresis) para analizar solamente la evolución de la sintomatología diurna (variable LUTS). RESULTADOS: Fueron incluidos 66 pacientes (50% niñas), con una edad media de 9,5 años (rango: 5-15). El TENS-S disminuyó significativamente el PLUTSS (19,1 inicial vs 9,5 final, p< 0,001) y el LUTS (13,1 inicial vs 4,8 final, p< 0,001). Además, redujo el número de micciones (8,5 inicial vs 6,4 final, p< 0,001) y aumentó el volumen de orina en los registros miccionales (214 ml inicial vs 258 ml final, p< 0,001). La enuresis fue la única variable refractaria al TENS-S. La tasa de complicaciones fue del 3% (2 pacientes, dermatitis en el área de aplicación del TENS-S). CONCLUSIONES: El TENS-S es efectivo y seguro a corto plazo en pacientes con VH refractarios a los Ach. Deben realizarse estudios para evaluar la eficacia a largo plazo y posibles recaídas.

Noise induced state transitions, intermittency, and universality in the noisy Kuramoto-Sivashinksy equation.

Consider the effect of pure additive noise on the long-time dynamics of the noisy Kuramoto-Sivashinsky (KS) equation close to the instability onset. When the noise acts only on the first stable mode (highly degenerate), the KS solution undergoes several state transitions, including critical on-off intermittency and stabilized states, as the noise strength increases. Similar results are obtained with the Burgers equation. Such noise-induced transitions are completely characterized through critical exponents, obtaining the same universality class for both equations, and rigorously explained using multiscale techniques.

Pinning and avalanches in hydrophobic microchannels.

Rare events appear in a wide variety of phenomena such as rainfall, floods, earthquakes, and risk. We demonstrate that the stochastic behavior induced by the natural roughening present in standard microchannels is so important that the dynamics for the advancement of a water front displacing air has plenty of rare events. We observe that for low pressure differences the hydrophobic interactions of the water front with the walls of the microchannel put the front close to the pinning point. This causes a burstlike dynamics, characterized by series of pinning and avalanches, that leads to an extreme-value Gumbel distribution for the velocity fluctuations and a nonclassical time exponent for the advancement of the mean front position as low as 0.38.

Regenerative and Resorbable PLA/HA Hybrid Construct for Tendon/Ligament Tissue Engineering.

Tendon and ligament shows extremely limited endogenous regenerative capacity. Current treatments are based on the replacement and or augmentation of the injured tissue but the repaired tissue rarely achieve functionality equal to that of the preinjured tissue. To address this challenge, tissue engineering has emerged as a promising strategy. This study develops a regenerative and resorbable hybrid construct for tendon and ligament engineering. The construct is made up by a hollow poly-lactic acid braid with embedded microspheres carrying cells and an anti-adherent coating, with all the parts being made of biodegradable materials. This assembly intends to regenerate the tissue starting from the interior of the construct towards outside while it degrades. Fibroblasts cultured on poly lactic acid and hyaluronic acid microspheres for 6 h were injected into the hollow braid and the construct was cultured for 14 days. The cells thus transported into the lumen of the construct were able to migrate and adhere to the braid fibers naturally, leading to a homogeneous proliferation inside the braid. Moreover, no cells were found on the outer surface of the coating. Altogether, this study demonstrated that PLA/HA hybrid construct could be a promising material for tendon and ligament repair.

Dynamical scaling of imbibition in columnar geometries.

Recent experiments on imbibition in columnar geometries show interfacial fluctuations whose dynamic scaling is not compatible with the usual nonlocal model governed by surface tension that results from a macroscopic description. To explore this discrepancy, we exhaustively analyze numerical integrations of a phase-field model with dichotomic columnar disorder. We find that two distinct behaviors are possible depending on the capillary contrast between the two values of disorder. In a high-contrast case, where interface evolution is mainly dominated by the disorder, an inherent anomalous scaling is always observed. Moreover, in agreement with experimental work, the interface motion has to be described through a local model. On the other hand, in a lower-contrast case, the interface is dominated by interfacial tension and can be well modeled by a nonlocal model. We have studied both spontaneous and forced-flow imbibition situations, giving a complete set of scaling exponents in each case, as well as a comparison to the experimental results.