Evaluation of the anorectal motor response after percutaneous stimulation of the posterior tibial nerve in patients with fecal incontinence.

BACKGROUND: The effect of posterior tibial nerve stimulation (PTNS) on the mechanisms of anal continence has not been fully demonstrated. The aim of this study was to assess the anal manometric response after percutaneous PTNS in patients with fecal incontinence (FI). METHODS: This was a prospective study in patients with FI undergoing 1 weekly session of percutaneous PTNS for 8 weeks. A clinical assessment (Wexner scale) and a complete study of up to 22 manometric parameters were carried out prior to treatment and 2-4 weeks after the end of treatment. RESULTS: A total of 32 patients were evaluated. After therapy, there was a decrease in the average Wexner score [12.6 (± 5.2) to 9.5 (± 5.2) (P < 0.005)] and an increase in the "anal canal length at rest" [4.55 (± 0.60) to 4.95 (± 0.21) P = 0.004], without observing variations in other manometric parameters. The decrease in the Wexner score was significantly correlated with an increase in the "pressure at 5 cm at rest" after therapy (r = 0.464 P = 0.030). CONCLUSIONS: In our study, PTNS was associated with a significant decrease in the Wexner score and with an increase in the functional length of the anal canal at rest. The improvement in the Wexner scale was correlated with an increase in pressure at rest in the theoretical area of the anorectal junction.

In-droplet cell lysis of AC16 human cardiomyocyte cells via surface acoustic waves.

Although several lysis methods are available, biomedical applications are pushing the demand for miniaturised systems and thus for new ways to lyse cells in small volumes. In this work, we demonstrate in-droplet cell lysis of AC16 human cardiomyocyte cells in 20 µL droplets using high frequency surface acoustic waves. The acoustic streaming leads to high shear flow creating porous or breaking the cell membrane and releasing intracellular material. Contrary to previous work where the lysis efficiency is measured by a cell-permeant dye that can be used to determine cell viability, here we propose to quantify the DNA extracted from the cells as a measure of the lysis efficiency. This reagent-free method provides a valuable cell lysis alternative for many biological and biomedical applications, particularly for the development of point-of-care platforms.

Effect of the shear rate and residence time on the lysis of AC16 human cardiomyocyte cells via surface acoustic waves.

The efficient breakage of one cell or a concentration of cells for releasing intracellular material such as DNA, without damaging it, is the first step for several diagnostics or treatment processes. As the cell membrane is easy to bend but resistant to stretching, the exposure of the cell to a shear rate during a short period of time can be sufficient to damage the membrane and facilitate the extraction of DNA. However, how to induce high shear stresses on cells in small microliter volumes samples has remained an elusive problem. Surface acoustic waves operating at high frequencies can induce acoustic streaming leading to shear rates sufficient to cell lysis. Lysis induced by acoustic streaming in sessile droplets has been investigated in the past from the lysis efficiency point of view. However, the effects of the velocity field and shear rate induced by acoustic streaming on the lysis process remain unexplored. Here, we study the lysis of AC16 human cardiomyocytes in microliter droplets under the effect of the shear rate induced by acoustic streaming. It is identified that for a given shear rate, the extracted DNA is also affected by the actuation period which can be attributed to a cycling process that leads to an accumulation of damage on the cell membrane.

Synthesis and characterization of PbSe nanoparticles obtained by a colloidal route using Extran as a surfactant at low temperature.

Lead selenide nanoparticles (PbSe NPs) have been obtained through an easy and low cost route using colloidal synthesis in aqueous solution. The synthesis was carried out at room temperature using Extran (Na5P3O10, NaOH and H2O) as surfactant. Hydrochloric acid (HCl) was used to eliminate the generated by-products. The size of PbSe NPs was varied by changing the Pb:Se molar concentration. The PbSe NPs were characterized by powder x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX), high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopy. The XRD measurements showed that the PbSe NPs have the face-centered cubic phase structure. The crystal size was found to be between 14 and 20 nm as calculated from the XRD patterns and these values were corroborated with SEM and TEM. Additionally, HRTEM micrographs showed crystalline planes at (200), (220) and (111) of the PbSe NPs, in agreement with the XRD results.

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.

Assessing substitution patterns, rates and homoplasy at HVRI of Steller sea lions, Eumetopias jubatus.

Despite the widely recognized incidence of homoplasy characterizing this region, the hypervariable region I (HVRI) of the mitochondrial control region is one of the most frequently used genetic markers for population genetic and phylogeographic studies. We present an evolutionary analysis of HVRI and cytochrome b sequences from a range-wide survey of 1031 Steller sea lions, Eumetopias jubatus, to quantify homoplasy and substitution rate at HVRI. Variation in HVRI was distributed across 41 variable sites in the 238-bp segment examined. All variants at HVR1 were found to be transitions. However, our analyses suggest that a minimum of 101 changes have actually occurred within HVRI with as many as 18 substitutions occurring at a single site. By including this hidden variation into our analyses, several instances of apparent long-range dispersal were resolved to be homoplasies and 8.5-12% of observed HVRI haplotypes were found to have geographic distributions descriptive of convergent molecular evolution rather than identity by descent. We estimate the rate of substitution at HVRI in Steller sea lions to be approximately 24 times that of cytochrome b with an absolute rate of HVRI substitution estimated at 27.45% per million years. These findings have direct implications regarding the utility of HVRI data to generate a variety of evolutionary genetic hypotheses.

Three-dimensional location of the imperatoxin A binding site on the ryanodine receptor.

Cryo-electron microscopy and three-dimensional, single-particle image analysis have been used to reveal the specific binding site of imperatoxin A (IpTx(a)) on the architecture of the calcium release channel/ryanodine receptor from skeletal muscle (RyR1). IpTx(a) is a peptide toxin that binds with high affinity to RyR1 and affects its functioning. The toxin was derivatized with biotin to enhance its detection with streptavidin. IpTx(a) binds to the cytoplasmic moiety of RyR1 between the clamp and handle domains, 11 nm away from the transmembrane pore. The proposed mimicry by IpTx(a) of the dihydropyridine receptor (DHPR) II-III loop, thought to be a main physiological excitation-contraction trigger, suggests that the IpTx(a) binding location is a potential excitation-contraction signal transduction site.

Physicochemical conditions for ZnO films deposited by microwave chemical bath deposition.

Physicochemical analysis was carried out to obtain the species distribution diagrams (SDDs) for the deposition of ZnO films as a function of OH- ion concentration ([OH-]) in the reaction solution. The study of SDDs predicts nucleation and ZnO film growth by means of the dominant species at a given pH value. To confirm this, a series of experiments were made varying the [OH-] in the reaction solution and keeping the others parameters constant. Structured zinc oxide (ZnO) films were obtained on glass substrates by microwave chemical bath deposition (MWCBD). Structural, optical and morphological ZnO film properties were investigated as a function of [OH-]. X-Ray diffraction technique (XRD) measurements show multiple diffraction peaks, indicating the polycrystalline nature of ZnO films. Scanning Electron Microscopy (SEM) images of ZnO structures showed morphological changes with the variation of [OH-]. The stoichiometry of the structures changed as the [OH-] was varied in solution. From Raman spectra, it was observed that the [OH-] of the reaction mixture strongly affects the crystal quality of ZnO structures. A reaction pathway for the synthesis of ZnO structures based on our results is proposed. Experimental results are consistent with the physical-chemical analysis.

Infección por bartonella henselae en pacientes pediátricos. Lesión pseudotumoral de calota. Reporte de caso

Los tumores de calota en pacientes pediátricos poseen múltiples etiologías. Dentro de las causas pseudotumorales, las infecciones juegan un rol importante, siendo la osteomielitis por Bartonella henselae (Enfermedad por Arañazo de Gato) una posibilidad diagnóstica rara, pero que debe ser estudiada y descartada. Se presenta el caso de una lactante de 1 año, con lesión expansiva de calota, a nivel frontal derecho, hipervascularizada e infiltrativa. Se realizó estudio con ultrasonido, tomografía cerebral y cintigrama óseo. Se realizó resección quirúrgica completa de la lesión, con preservación de la duramadre y zona fontanelar, además de un cuidadoso trato con el seno sagital superior. Evolucionó sin complicaciones perioperatorias. El resultado de la biopsia fue compatible con proceso inflamatorio crónico, osteomielitis supurada. Tinción de Warthin Starry positiva sugerente de Bartonella henselae. Se descartó etiología tuberculosa y fúngica. Serología positiva para Bartonella henselae. La paciente completó antibioticoterapia, azitromicina y cotrimoxazol, con evolución clínica favorable.

Calvarial tumors in pediatric patients have multiple etiologies. Among the pseudotumoral causes, infections play an important role, being Bartonella henselae osteomyelitis (Cat Scratch Disease) a rare diagnostic possibility, but it should be studied and ruled out. We present the case of a 1 year old infant, with an expansive lesion of the calvaria, at right frontal level, hypervascularized and infiltrative. Ultrasound, brain tomography and bone scintigram were performed. Complete surgical resection of the lesion was performed, with preservation of the dura mater and fontanel area, in addition to a careful treatment with the superior sagittal sinus. The patient evolved without perioperative complications. The biopsy result was compatible with a chronic inflammatory process, suppurative osteomyelitis. Positive Warthin Starry stain suggestive of Bartonella henselae. Tuberculous and fungal etiology was ruled out. Positive serology for Bartonella henselae. The patient completed antibiotic therapy, azithromycin and cotrimoxazole, with favorable clinical evolution.

Manejo anestésico en cirugía de craneosinostosis / Anesthesia for Craniosynostosis surgery

Craniosynostosis is a congenital disorder whose surgical management includes extensive surgeries with high rates of bleeding and transfusión. Anesthetic management is a challege both due to the characteristcs of the patients and due to complications secondary to surgery. OBJECTIVE: To describe the anesthetic management and the behavior of its variables in patients undergoing craniosynostosis remodeling at the Hospital Clínico Regional Concepción (HCRC), Chile. CONCLUSIONES: Blood transfusión in these patients is frequent.

La craneosinostosis es un desorden congénito cuyo manejo quirúrgico comprende extensas cirugías con altas tasas de sangrado y transfusión. El manejo anestésico es un desafío tanto por las características propias de los pacientes como por las complicaciones secundarias a la cirugía. OBJETIVO: Describir el manejo anestésico y el comportamiento de sus variables en pacientes sometidos a remodelación de craneosinostosis en el Hospital Clínico Regional Concepción (HCRC), Chile. MÉTODO: Estudio observacional de cohorte retrospectivo en pacientes intervenidos entre el 1 de agosto de 2015 y el 1 de junio de 2019 en el HCRC. Los datos fueron extraídos de historias clínicas y registros anestésicos. RESULTADOS: El sangrado promedio fue de 18,4 ml/ kg. Se realizó transfusión de glóbulos rojos en el 75,7% de los pacientes con un promedio de 16 ml/kg. Se constata una mayor asociación de sangrado y transfusiones en cirugías de trigonocefalia, braquicefalia o craneosinostosis múltiple, también en pacientes que presentaron hipotermia y cirugías prolongadas. La técnica anestésica no presentó diferencias significativas en cuanto al sangrado. El uso de ácido tranexámico se asoció a menor tasa de transfusiones. CONCLUSIONES: La transfusión sanguínea en estos pacientes es frecuente.

Characterization of the hepatic insulin receptor undergoing internalization through clathrin-coated vesicles and endosomes.

Administration of insulin to rats caused a transient increase in the amount of hepatic insulin receptor present in clathrin-coated vesicles and endosomes. However, the total 'in vitro' insulin stimulated tyrosine kinase activity of the receptor present in endosomes did not vary when expressed per mg of protein and decreased when expressed per beta-subunit content. A decrease in the endogenous phospho tyrosine content of the receptor beta-subunit was observed in endosomes in response to insulin. This indicates that a fraction of the internalized receptor is dephosphorylated in endosomes, which renders it unable to become stimulated by insulin 'in vitro'.

Dissociation of the hepatic insulin receptor favours its phosphorylation by casein kinase 2.

The alpha beta heterodimeric form of untreated hepatic insulin receptor was a substrate for casein kinase 2, whereas the alpha 2 beta 2 heterotetramer was not. On the contrary, autophosphorylation was detected only in the heterotetramer. Dissociation of the receptor by treatment with dithiothreitol decreased its autophosphorylation but favoured phosphorylation of its beta-subunit by casein kinase 2.

Protein kinase CK2 is altered in insulin-resistant genetically obese (fa/fa) rats.

Hepatic insulin receptor levels in 6-week-old obese (fa/fa) rats were about 2-fold lower than those from lean (Fa/-) rats, which agrees with their insulin-resistant state. Nuclear protein kinase CK2 activity and protein content in livers from obese (fa/fa) rats were similar to those of lean (Fa/-) animals but the cytosolic levels were reduced to half, due to a decrease in the 39-kD)a catalytic subunit. Marked increases in activity, due to rises in the 44-kDa and 39-kDa catalytic subunits, were seen in the 16000 x g sediments (M1) from insulin-resistant rats, with moderate changes in the 100000xg sediments (M2). The increase in CK2 binding to M1 did not require increases in the molecular chaperone grp94, which was unaltered in insulin-resistant rats.

Charge exchange and threshold effect in the energy loss of slow projectiles

In this Letter, we study charge exchange and energy loss of protons, taking into account the dynamics of both nuclei and electrons during the collision with atomic hydrogen, helium, and neon targets. We obtain the nuclear and electronic contributions to the energy loss as well as the charge exchange probability, and the total cross section for charge exchange. We find a low-energy threshold in the electronic energy loss due to the quantization of excited states. We find that the electronic stopping cross section is not proportional to the velocity of the projectile at very low velocities (energies), as is predicted by electron gas theory. This confirms recent experimental results.

Partial antagonism of 8-OH-DPAT'S effects on male rat sexual behavior with a D2, but not a 5-HT1A, antagonist.

The serotonin agonist 8-hydroxy-di-propylaminotetralin (8-OH-DPAT), injected systemically or directly into the medial preoptic area (MPOA), reduces the ejaculatory threshold in male rats. While 8-OH-DPAT has been characterized as an agonist at the 5-HT1A receptor, it also acts at other receptor sites including the dopamine D2 receptor. The current experiments investigated whether 8-OH-DPAT injected into the MPOA facilitates male sexual behavior through stimulation of the 5-HT1A receptor or the dopamine D2 receptor. Experiment 1 co-administered 8-OH-DPAT (6 microgram) with either the 5-HT1A antagonist 4-iodo-N-[2-[4-(methoxyphenyl)-1-piperazinyl]ethyl]-N-2-pyridinyl-ben zamide hydrochloride (MPPI) (10 microgram) or the D2 antagonist raclopride (10 microgram). Raclopride blocked 8-OH-DPAT's facilitative effects on ejaculation frequency and latency, while the 5-HT1A antagonist was ineffective. In Experiment 2, 8-OH-DPAT (500 microM), retrodialyzed into the MPOA through a microdialysis probe, enhanced male copulatory behavior similarly to the microinjection, increasing ejaculation frequency and decreasing ejaculation latency, postejaculatory interval and mount frequency. Retrodialyzing 8-OH-DPAT through a microdialysis probe in the MPOA had been previously shown to increase extracellular levels of dopamine and serotonin. The data from the present studies suggest that the effects of 8-OH-DPAT in the MPOA on male rat copulatory behavior may be mediated, at least in part, either directly through 8-OH-DPAT's activity at D2 receptors or indirectly through 8-OH-DPAT's ability to increase extracellular dopamine.

[3H] gamma-aminobutyric acid transport in rat substantia nigra pars reticulata synaptosomes: pharmacological characterization and phorbol ester-induced inhibition.

In synaptosomes from rat substantia nigra pars reticulata, [3H] gamma-aminobutyric acid (GABA) uptake was inhibited by GABA, (+/-)-nipecotic acid, beta-alanine and SKF 89976-A. Inhibition was concentration-dependent and monophasic, with IC50 values that agree with those reported for the cloned rat GABA transporter GAT-1. [3H]GABA uptake was modestly, but significantly, reduced (21 +/- 3% inhibition) by 100 nM phorbol 12-tetradecanoyl-13-acetate (TPA), an activator of protein kinase C (PKC). The inhibitory action of TPA was reversed by the PKC inhibitor staurosporine (100 nM). Saturation analysis revealed that TPA reduced the maximum capacity of transport with no change in the affinity for GABA. [3H]GABA uptake was unaffected by either forskolin (10 microM) or 8-bromo-cAMP (500 microM). These results indicate that SNr GABAergic afferents express the GAT-1 transporter whose activity can be regulated by a PKC-mediated mechanism.

Histamine H1 receptors and inositol phosphate formation in rat thalamus.

In membranes of rat thalamus the density of histamine H1 receptors, as estimated from saturation curves with [3H]mepyramine, was 66 +/- 5 fmol.mg protein-1 (Kd 1.3 +/- 0.1 nM). Specific [3H]mepyramine binding was inhibited by mepyramine (best fit to one-site model, Kd 2.2 +/- 0.2 nM) and by histamine (best fit to a two-site model, Ki high 0.35 +/- 0.04 microM and 54 +/- 7% of binding sites; Ki low 7.0 +/- 1.1 microM). In the presence of 300 microM GppNHp (5'-guanylylimidodiphosphate) the inhibition curve for histamine best-fit to a one-site model (Ki 3.1 +/- 0.3 microM). In cross-chopped slices and in the presence of 10 mM LiCl, histamine stimulated the accumulation of total [3H]inositol phosphates ([3H]IPs) with a maximum effect of 163 +/- 3% of basal accumulation, EC50 of 8 +/- 2 microM and Hill coefficient (nH) of 0.8 +/- 0.1. [3H]IPs accumulation induced by 100 microM histamine was inhibited by the selective H1 antagonist mepyramine (1 microM, 90 +/- 8% inhibition; Ki 2.1 +/- 0.4 nM) but not by 10 microM ranitidine (a selective H2 antagonist) or 1 microM thioperamide (a selective H3 antagonist). These results show the presence in rat thalamus of functional H1 receptors coupled in inositol phosphate accumulation.

Congenital esophageal cysts--two cases in adult patients.

Esophageal cysts are a rare clinicopathological condition. They usually cause respiratory symptoms in children, while they are often asymptomatic in adults. Two cases of esophageal cysts in adults, recently diagnosed and treated in our department, are reported. In the 1st case (a 52 year-old woman) dysphagia was the main symptom. In the 2nd one (a 39 year-old woman) the patient was asymptomatic. Both were surgically excised by enucleation, with no post-operative complications. The histological study showed both cysts to be lined with ciliated cylindrical epithelium, and they were therefore considered to be congenital. Smooth muscle was only seen in the cyst wall in the 2nd case, but it was not organized in 2 layers, as is typical of duplication cysts. Cartilage or respiratory glands, the pathognomonic features of bronchogenic cysts, were not identified in either of them. Therefore, the diagnosis was inclusion cysts in both cases.

The value of D1 lymphadenectomy as prognostic marker in gastric cancer.

BACKGROUND/AIMS: To assess if the study on the involvement of perigastric lymph nodes, the only ones resected in D1 lymphadenectomy, is a valid prognostic marker in patients undergoing curative resection for gastric cancer. METHODOLOGY: A retrospective study was performed in 101 patients with gastric cancer, 34 women and 67 men, with a mean age of 61 years, undergoing curative resection by gastrectomy and D1 lymphadenectomy. Tumor size, the depth of tumoral invasion of the wall, nodal involvement and 5-year survival were assessed. RESULTS: Both tumor size and the depth of tumoral invasion of the wall were significantly related to metastatic involvement of perigastric lymph nodes. Similarly, tumoral involvement of the first-level lymph nodes was significantly associated with survival. CONCLUSIONS: D1 lymphadenectomy can provide adequate prognostic information in patients with gastric cancer undergoing curative resection.