Serum microRNAs Catalog Asthma Patients by Phenotype.

BACKGROUND AND OBJECTIVES: Asthma is a chronic inflammatory condition of the airways with a complex pathophysiology. Stratification of asthma subtypes into phenotypes and endotypes should move the field forward, making treatment more effective and personalized. Eosinophils are the key inflammatory cells involved in severe eosinophilic asthma. Given the health threat posed by eosinophilic asthma, there is a need for reliable biomarkers to identify affected patients and treat them properly with novel biologics. microRNAs (miRNAs) are a promising diagnostic tool. The aim of this study was to identify serum miRNAs that can phenotype asthma patients. METHODS: Serum miRNAs of patients with eosinophilic asthma (N=40) and patients with noneosinophilic asthma (N=36) were evaluated using next-generation sequencing, specifically miRNAs-seq, and selected miRNAs were validated using RT-qPCR. Pathway enrichment analysis of deregulated miRNAs was performed. RESULTS: Next-generation sequencing revealed 15 miRNAs that were expressed differentially between eosinophilic and noneosinophilic asthma patients, although no differences were observed in the miRNome between atopic and nonatopic asthma patients. Of the 15 miRNAs expressed differentially between eosinophilic and noneosinophilic asthma patients, hsa-miR-26a-1-3p and hsa-miR-376a-3p were validated by RT-qPCR. Expression levels of these 2 miRNAs were higher in eosinophilic than in noneosinophilic asthma patients. Furthermore, expression values of hsa-miR-26a-1-3p correlated inversely with peripheral blood eosinophil count, and hsa-miR-376a-3p expression values correlated with FeNO values and the number of exacerbations. Additionally, in silico pathway enrichment analysis revealed that these 2 miRNAs regulate signaling pathways associated with the pathogenesis of asthma. CONCLUSIONS: hsa-miR-26a-1-3p and hsa-miR-376a-3p could be used to differentiate between eosinophilic and noneosinophilic asthma.

Mimicking the temperature gradient between the sow's oviduct and uterus improves in vitro embryo culture output.

This work was designed to determine temperature conditions within the reproductive tract of the female pig and study their impact on ARTs. Temperatures were recorded using a laparo-endoscopic single-site surgery assisted approach and a miniaturized probe. Sows and gilts were used to address natural cycle and ovarian stimulation treatments, respectively. According to in vivo values, IVF was performed at three temperature conditions (37.0°C, 38.5°C and 39.5°C) and presumptive zygotes were cultured in these conditions for 20 h, while further embryo culture (EC) (21-168 h post-insemination) was maintained at 38.5°C. After 20 h, different fertility parameters were assessed. During EC, cleavage and blastocyst stages were evaluated. Sperm membrane fluidity at the experimental temperatures was studied by using differential scanning calorimetry and fluorescence recovery after photobleaching techniques. An increasing temperature gradient of 1.5°C was found between the oviduct and uterus of sows (P < 0.05) and when this gradient was transferred to pig in vitro culture, the number of poly-nuclear zygotes after IVF was reduced and the percentage of blastocysts was increased. Moreover, the temperature transition phase for the boar sperm membrane (37.0°C) coincided with the temperature registered in the sow oviduct, and sperm membranes were more fluid at 37.0°C compared with those of sperm incubated at higher temperatures (38.5°C and 39.5°C). These data suggest that there may be an impact of physiological temperature gradients on human embryo development.

Laparoscopic longitudinal pancreaticojejunostomy for chronic pancreatitis: Systematic review of the literature.

BACKGROUND: Longitudinal pancreaticojejunostomy, also known as modified Puestow or Partington-Rochelle procedure, is a technique for the treatment of chronic pancreatitis. It is usually performed by laparotomy, but in a very small number of cases it has been performed using a laparoscopic or robot-assisted approach. We carried out a systematic literature review to clarify the current status of laparoscopic longitudinal pancreatojejunostomy (LLPJ). METHODS: Adhering to the PRISMA guidelines, a systematic search for LLPJ was performed in PubMed, Embase, and Cochrane Library, for articles published up to 31 December 2017. RESULTS: 357 articles were evaluated for eligibility and 17 were included for critical appraisal: eight case reports, eight retrospective case series, and one series of cases and controls without randomization. All of them had a grade of recommendation C and a level of evidence 4 according to the CEBM. Patients were relatively young (mean age 37 years), with a slight preponderance of males (ratio 1.3: 1). All had long-standing disease, ERCP prior to surgery and a dilated pancreatic duct (mean 11 mm). The surgery was usually performed laparoscopically using four trocars; the conversion rate was low (5%), bleeding was minimal, the morbidity rate was 11% and no mortality was reported. Mean hospital stay was 5.6 days. The follow-up period varied but was usually short (less than two years). The results for pain control were very good since 90% of patients reported no pain, although visual analog scales were rarely used. CONCLUSIONS: In conclusion, LLPJ seems to be a safe, feasible and effective technique in patients with chronic pancreatitis. However, the number of descriptions published to date is very small, and there are no studies with high scientific evidence comparing LLPJ with open surgery or with endoscopic treatment that would allow us to draw firmer conclusions at the present time.

Plastinated macroparasites, an alternative resource for use in practical lessons.

The plastination technique is a recently developed option to preserve biological tissues widely used in human and veterinary anatomy. This process allows one to obtain real, safe, clean, dry, resistant and permanently stable material without any additional treatment or maintenance. All these advantages are associated with the rapid expansion of plastination during recent decades in a high number of educational institutions. However, the studies of parasite conservation through plastination are scarce, although the material obtained has a high quality, as prior references have shown. In this study, 141 students of veterinary medicine and pharmacy university degrees used, in a blind study, plastinated specimens (experimental group) or wet specimens (control group) during three consecutive practical sessions. Afterwards all the students completed anonymous questionnaires on both knowledge and satisfaction. The results demonstrated that plastinated parasites are a valid and satisfactory alternative to be used as a teaching/learning tool during practical lessons. Moreover, with regard to the knowledge of morphological structures, the results from the questionnaire of assimilated knowledge showed no differences between the use of plastinated and formaldehyde-preserved parasites.

La technique de plastination est une méthode assez récente de préservation des tissus biologiques qui est désormais largement utilisée en anatomie humaine et vétérinaire. Ce procédé permet d'obtenir des préparations anatomiques réalistes, sûres, sèches, résistantes et stables qui ne nécessiteront pas de traitement ni d'entretien ultérieurs pour préserver leur durabilité. Ces avantages expliquent que le recours à la plastination se soit rapidement développé au cours des dernières décennies dans nombre d'institutions d'enseignement. Néanmoins, rares sont les études portant sur la préservation des parasites par plastination, bien que les spécimens obtenus lors de travaux antérieurs aient été jugés de très bonne qualité. Les auteurs présentent les résultats d'une enquête menée auprès de 141 étudiants préparant leur diplôme de médecine vétérinaire ou de pharmacie, à qui ont été distribués en aveugle des spécimens plastinés (groupe expérimental) et des spécimens conservés dans une solution liquide (groupe de contrôle) lors de trois séances consécutives de travaux pratiques. Il a ensuite été demandé aux étudiants de remplir anonymement un questionnaire portant sur les connaissances acquises lors de ces séances et sur leur degré de satisfaction. Les résultats ont montré que les parasites plastinés constituent une alternative valable et satisfaisante en tant que matériel pédagogique et d'entraînement pendant les leçons pratiques. Par ailleurs, s'agissant de l'étude des structures morphologiques, les résultats du questionnaire sur les connaissances acquises lors des travaux pratiques n'ont pas fait apparaître de différences entre les étudiants ayant travaillé sur des parasites plastinés et ceux ayant travaillé avec des parasites conservés dans le formol.

La técnica de la plastinación es un método de reciente aparición para conservar tejidos biológicos, utilizado con gran frecuencia en anatomía humana y veterinaria. Se trata de un proceso que permite obtener material real, inocuo, limpio, seco, resistente y con una estabilidad permanente sin necesidad de ninguna otra operación de tratamiento o mantenimiento. Todas estas ventajas explican que en los últimos decenios la técnica se haya extendido con rapidez por muy numerosas instituciones de enseñanza. Aun así, hay escasos estudios sobre la conservación de parásitos por plastinación, pese a que el material obtenido, como se desprende de referencias anteriores, es de gran calidad. Los autores describen un estudio ciego en el que 141 estudiantes universitarios en farmacia y medicina veterinaria emplearon muestras plastinadas (grupo experimental) o muestras húmedas (grupo de control) en tres clases prácticas consecutivas, tras lo cual todos los estudiantes respondieron anónimamente a un cuestionario que evaluaba tanto sus conocimientos como su nivel de satisfacción. Los resultados demostraron que los parásitos plastinados constituyen una alternativa válida y satisfactoria como herramienta para impartir y/o recibir clases prácticas. Además, desde el punto de vista del conocimiento de estructuras morfológicas, los resultados del cuestionario sobre conocimientos asimilados no pusieron de manifiesto diferencia alguna entre el uso de parásitos plastinados y el de parásitos conservados en formaldehído .

Mimicking physiological O2 tension in the female reproductive tract improves assisted reproduction outcomes in pig.

STUDY QUESTION: Is O2 tension in the pig oviduct and uterus affected by the estrous cycle stage and the animal's age, and can the outcome of in vitro embryo development be improved by mimicking these physiological values? SUMMARY ANSWER: O2 tension within the pig reproductive organs is affected by the animal's age, and values close to those measured in vivo have a positive impact on embryo development and quality when used during IVF and embryo culture (EC). WHAT IS KNOWN ALREADY: To obtain a healthy embryo in vitro, it is necessary to adopt a culture microenvironment that approximates physiological conditions. Despite advances in surgical procedures and sensitive probes that allow accurate assessment of in vivo O2 tension, few such studies have been conducted recently in mammals. In addition, no reference values of physiological O2 tension in the reproductive tract exist for large animal models such as pig, and the effect of O2 tension on ART outcomes is unknown. STUDY DESIGN, SIZE, DURATION: This study was conducted in pigs. We measured oviductal and uterine O2 tension (n = 29 and 13, respectively) and then examined how the use of the physiological values in pig IVF and EC affected pig ART output (n = 1447 oocytes). PARTICIPANTS/MATERIALS, SETTING, METHODS: The oviductal and uterine O2 tension at the different stages of the estrous cycle was monitored using a laparo-endoscopic single-site surgery (LESS) assisted approach along with a flexible and thin miniaturized luminescent probe. Two groups of pigs, Large-white × Landrace breed, were used: for the first group, 16 pre-pubertal gilts (5 months old and 95 kg) were induced to ovulate with equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG); in the second group 13 mature sows (24-48 months and 185 kg) were used. IVF and EC were performed at two different O2 tensions: Atmospheric O2 (20%) and the mean in vivo value measured (7%). At 18-20 h post-insemination (hpi), a small sample of presumptive zygotes were fixed, stained and examined under epifluorescence microscopy to assess the fertilization rates. At 48 hpi, cleavage was evaluated under the stereomicroscope. Finally, at 180 hpi, development to the blastocyst stage was quantified, blastocyst morphology was assessed, and embryos were fixed and stained to count the mean cell number per blastocyst. MAIN RESULTS AND THE ROLE OF CHANCE: The mean O2 content within the pig oviduct and uterus was always lower than in ambient air. The average O2 percentage was higher in gilts (10.0%) than in sows (7.6%) (P < 0.0001). The cleavage rate of porcine in vitro fertilized embryos maintained under 7% O2 during IVF and EC was significantly higher (60.0 ± 2.3) compared with those cultured under 20% O2 (32.0 ± 2.2) (P < 0.05). An increase in the number of cells in embryos cultured under the low O2 concentration (88.9 ± 5.9) was observed compared to those cultured under 20% O2 (59.0 ± 5.0) (P < 0.05). LARGE SCALE DATA: None. LIMITATIONS, REASONS FOR CAUTION: Although minimally invasive surgery was used the effect of anesthesia and manipulations on O2 tension within the organs are unknown. WIDER IMPLICATIONS OF THE FINDINGS: Using physiological oxygen concentrations in IVF/EC could improve ART outcomes. STUDY FUNDING AND COMPETING INTEREST(S): This study was funded by Spanish Ministry of Economy and Competitiveness (MINECO) and European Regional Development Fund (FEDER). Grants AGL2012-40180-C03-01 and AGL2015-66341-R. The authors declare no conflict of interest.

Effects of pneumoperitoneum and body position on the morphology of the caudal cava vein analyzed by MRI and plastinated sections.

BACKGROUND: Pneumoperitoneum and patient positioning are essential factors during laparoscopic surgical procedures. They cause hemodynamic and anatomical changes in several abdominal organs among which the caudal cava vein (CCV) is involved. Hemodynamic changes in this vein (decreased venous return) have been described in the porcine model, but how the vein morphology and size is affected at different abdominal levels is unknown. We sought to assess the morphological and morphometrical changes in the CCV of the pig caused by pneumoperitoneum and the reverse Trendelenburg position by in vivo magnetic resonance imaging (MRI). METHODS: Six pigs were scanned via MRI under four situations: S1, control (no pneumoperitoneum); S2, control in the reverse Trendelenburg position; S3, pneumoperitoneum (14 mmHg); and S4, pneumoperitoneum in the reverse Trendelenburg position. MRI and plastinated body sections were used to evaluate the topography, morphology and cross-sectional area of the CCV. RESULTS: Two portions of the CCV were differentiated: a prehepatic portion (located between the vertebral levels L1-T15) with flat and irregular morphology, and a hepatic portion (between T14-T11) that was almost rounded. The reverse Trendelenburg position caused an increase in the lumen affecting mainly the prehepatic portion, while pneumoperitoneum caused a decrease in the total vascular lumen, exerting a greater effect on the hepatic portion. The combination of both situations resulted in a further decrease in the vascular area and global morphological changes. CONCLUSIONS: The pneumoperitoneum and reverse Trendelenburg position caused morphological and morphometrical changes in the prehepatic and hepatic portions of the CCV, which should assist in gaining a better understanding of the hemodynamic changes described in the literature.

What do we see when we do not see the bladder? Review of the main urinary diversion techniques and their complications.

OBJECTIVE: To review the different types of urinary diversion surgeries (UDS) in order to recognize the expected findings in a postoperative study, using different imaging techniques. To recognize the main postoperative complications, both early and late. CONCLUSION: UDS are surgical procedures whose purpose is to redirect urine flow after cystectomy, generally in an oncologic context. The imaging evaluation of urological surgeries is often a radiological challenge, with CT being the most commonly used image modality. Therefore, it is essential to know the main surgical techniques, the expected postoperative findings and the optimization of imaging techniques for early diagnosis and correct evaluation of postoperative complications.

Validity of insertion depth measurement in double-balloon endoscopy.

BACKGROUND AND STUDY AIMS: In double-balloon enteroscopy (DBE) the use of a reliable and practical method to calculate the insertion depth of the endoscope could help to improve diagnosis accuracy and optimize the effort and cost of the technique. The objectives of this work were to compare and evaluate two methods of estimating the insertion depth and to obtain a descriptive model capable of representing the exploration dynamics and efficiency in terms of advanced distance and time. METHODS: Oral DBE was performed in 25 pigs. Insertion depth was calculated during the procedure by: 1) estimation of time and distance for each push and pull cycle during progression; and 2) estimation of distance during withdrawal. At the maximum insertion depth a tattoo was placed, and the observed measures for the two methods were compared with the distance between the pylorus and the mark after euthanasia and necropsy of the animals 1 week after DBE. RESULTS: The average insertion depth during progression, withdrawal, and after necropsy was 324.92 cm, 317.23 cm, and 342.05 cm, respectively (P Anova = 0.72). The Pearson correlation coefficient (r > 0.85; P < 0.001) and paired Brand - Altman plots demonstrated high agreement between progression and necropsy (0.03 % difference) and between withdrawal and necropsy (6.9 % difference). The exploration dynamics and efficiency in terms of advanced distance per cycle and time fitted to potential and logarithmic regression models, respectively. CONCLUSIONS: Measurement of insertion depth in vivo was validated in the porcine model during progression and withdrawal. Estimation during progression was more accurate and allowed exploration dynamics and efficiency to be plotted, which might be used as approximate reference values for humans.

Anatomical changes due to pneumoperitoneum analyzed by MRI: an experimental study in pigs.

PURPOSE: Different effects on cardiovascular and respiratory systems and liver are associated with pneumoperitoneum. This study aimed to determine the morphological changes in the abdominal anatomy as a result of increased intra-abdominal pressure due to pneumoperitoneum using MRI. METHODS: Ten healthy female pigs were used in this study. MRI studies of the abdomen in supine position were made before the creation of pneumoperitoneum and 1 h after increasing the pressure to 14 mmHg. Changes in area, volume, and longitudinal and transverse length of the liver were measured. The diameters of the lumen of the abdominal aorta, the inferior vena cava and portal vein were observed in three positions along the abdominal cavity. The position of the diaphragm after the induction of pneumoperitoneum was also analyzed. RESULTS: After induction of pneumoperitoneum, volume and transverse length of the liver was significantly increased, while peak area was decreased. Stenosis in the aortic lumen was observed (P < 0.05). Longitudinal and transverse diameters of the portal lumen were reduced, but significant differences were only found in the longitudinal diameter. Alterations in the diameter of the inferior vena cava lumen were obtained in three analyzed positions, but differences were significant only in two of them. A mean cranial displacement of the diaphragm equal to 25 mm was also observed. CONCLUSION: Increasing abdominal pressure up to laparoscopic pressure (14 mmHg) provokes morphological changes in the liver, vascular structures and diaphragm. These changes could be related to functional alterations that different organs experience after the induction of pneumoperitoneum.

[Novelities in resuscitation training methods]. / Novedades en métodos formativos en resucitación.

The importance of cardiac arrest as a health problem makes training in resuscitation a topic of great interest. It is necessary to enhance resuscitation training for all citizens, starting in schools and institutes, targeting teachers and nurses for training, to in turn become future trainers. The model of short courses with video-instruction and the use of mannequins is useful for the dissemination of resuscitation techniques. Liberalization of the use of automated external defibrillators (AED) and reduction of the training requirements in basic life support and AED for those non-health professionals who can use them, seems appropriate. Training must be improved in schools of medicine and nursing schools at undergraduate level. Health professionals should be trained according to their needs, with emphasis on non-technical skills such as leadership and teamwork. The model based on the use of trainers and low-fidelity mannequins remains a basic and fundamental element in training. Training through performance evaluation is a technique that should be implemented in all areas where cases of cardiac arrest are seen and the healthcare team has intervened. Simulation appears to be defined as the current and future modality for training in various medical areas, including of course the important field of resuscitation. Lastly, research in resuscitation training should be considered an example of translational science, where rigorous studies of skill acquisition with outcome measures serve to transfer the results to the clinical environment for analysis of their impact upon patient care.

Reproductive fluids, used for the in vitro production of pig embryos, result in healthy offspring and avoid aberrant placental expression of PEG3 and LUM.

BACKGROUND: In vitro embryo production (IVP) and embryo transfer (ET) are two very common assisted reproductive technologies (ART) in human and cattle. However, in pig, the combination of either procedures, or even their use separately, is still considered suboptimal due to the low efficiency of IVP plus the difficulty of performing ET in the long and contorted uterus of the sow. In addition, the potential impact of these two ART on the health of the offspring is unknown. We investigated here if the use of a modified IVP system, with natural reproductive fluids (RF) as supplements to the culture media, combined with a minimally invasive surgery to perform ET, affects the output of the own IVP system as well as the reproductive performance of the mother and placental molecular traits. RESULTS: The blastocyst rates obtained by both in vitro systems, conventional (C-IVP) and modified (RF-IVP), were similar. Pregnancy and farrowing rates were also similar. However, when compared to in vivo control (artificial insemination, AI), litter sizes of both IVP groups were lower, while placental efficiency was higher in AI than in RF-IVP. Gene expression studies revealed aberrant expression levels for PEG3 and LUM in placental tissue for C-IVP group when compared to AI, but not for RF-IVP group. CONCLUSIONS: The use of reproductive fluids as additives for the culture media in pig IVP does not improve reproductive performance of recipient mothers but could mitigate the impact of artificial procedures in the offspring.

Magnetic resonance imaging of the equine temporomandibular joint anatomy.

REASONS FOR PERFORMING STUDY: In human medicine, magnetic resonance imaging (MRI) is considered the 'gold standard' imaging procedure to assess the temporomandibular joint (TMJ). However, there is no information regarding MRI evaluation of equine TMJ. OBJECTIVES: To describe the normal sectional MRI anatomy of equine TMJ by using frozen and plastinated anatomical sections as reference; and determine the best imaging planes and sequences to visualise TMJ components. METHODS: TMJs from 6 Spanish Purebred horse cadavers (4 immature and 2 mature) underwent MRI examination. Spin-echo T1-weighting (SE T1W), T2*W, fat-suppressed (FS) proton density-weighting (PDW) and fast spin-echo T2-weighting (FSE T2W) sequences were obtained in oblique sagittal, transverse and dorsal planes. Anatomical sections were procured on the same planes for a thorough interpretation. RESULTS: The oblique sagittal and transverse planes were the most informative anatomical planes. SE T1W images showed excellent spatial resolution and resulted in superior anatomic detail when comparing to other sequences. FSE T2W sequence provided an acceptable anatomical depiction but T2*W and fat-suppressed PDW demonstrated higher contrast in visualisation of the disc, synovial fluid, synovial pouches and articular cartilage. CONCLUSIONS: The SE T1W sequence in oblique sagittal and transverse plane should be the baseline to identify anatomy. The T2*W and fat-suppressed PDW sequences enhance the study of the articular cartilage and synovial pouches better than FSE T2W. POTENTIAL RELEVANCE: The information provided in this paper should aid clinicians in the interpretation of MRI images of equine TMJ and assist in the early diagnosis of those problems that could not be diagnosed by other means.

[Hypokalemic periodic paralysis: a systematic review of published case reports]. / Parálisis periódica hipocaliémica: revisión sistemática de casos publicados.

INTRODUCTION: Hypokalemic periodic paralysis is a neuromuscular disease characterized by a combination of flaccid paralysis episodes (or muscular weakness) that are related to low levels of potassium in blood. As a consequence of its low prevalence, there are still clinical and management aspects to characterize. PATIENTS AND METHODS: A systematic review of the clinical cases published in the last decade has been developed by analyzing demographic and genetic features, the episodes' characteristics, the received treatments, the response to them and also, the differences and evolution of patients depending on the most prevalent genetic alterations: CACNA1S and SCN4A. RESULTS: A total of 33 articles were included, allowing 40 individuals to be reviewed. The average age of onset of symptoms was 15.3 ± 9.7 years. The most frequent altered gene was CACNA1S in 20 (60.5%) cases. It was observed that subjects presenting an alteration of the gene responsible for the calcium channel, CACNA1S, presented lower serum potassium levels, own triggers and a higher proportion of subjects showing dyspnea during the crisis. Only 50% of the subjects respond to classical oral treatment with acetazolamide. Potassium-sparing diuretics and antiepileptics drugs emerge as an alternative. CONCLUSION: Hypokalemic periodic paralysis has an heterogeneous clinical expression with phenotypic differences linked to different genetic mutations. The common preventive treatment response is suboptimal. Prospective studies are needed to discern the best therapeutic option based on genetic load.

TITLE: Parálisis periódica hipocaliémica: revisión sistemática de casos publicados.Introducción. La parálisis periódica hipocaliémica es una enfermedad neuromuscular hereditaria que se caracteriza por presentar episodios de parálisis flácida o debilidad muscular relacionados con niveles bajos de potasio en sangre. Como consecuencia de su baja prevalencia, todavía hay aspectos clínicos y de manejo por caracterizar. Pacientes y métodos. Se desarrolla una revisión sistemática de los casos clínicos publicados en la última década, analizando las características demográficas y genéticas, las características de los episodios, los tratamientos recibidos y su respuesta, y las diferencias y evolución de los pacientes en función de las mutaciones de los genes más prevalentes: CACNA1S y SCN4A. Resultados. Se incluyeron 33 artículos, que permitieron revisar a 40 sujetos. La edad media del inicio de los síntomas fue de 15,3 ± 9,7 años. El gen alterado con mayor frecuencia fue CACNA1S en 20 (60,5%) casos. Se observó que los sujetos con alteración del gen del canal de calcio CACNA1S presentaron niveles de potasio sérico inferiores, factores desencadenantes propios y una mayor proporción de sujetos con disnea en las crisis. La respuesta al tratamiento oral clásico con acetazolamida sólo alcanzó el 50%. Los diuréticos ahorradores de potasio y los fármacos antiepilépticos emergieron como una alternativa. Conclusiones. La parálisis periódica hipocaliémica tiene una expresión clínica heterogénea con diferencias fenotípicas ligadas a las diferentes mutaciones genéticas. La respuesta al tratamiento preventivo habitual es subóptima. Son necesarios estudios prospectivos para poder discernir la mejor opción terapéutica en función de la carga genética.

Influence of cholesterol on water penetration into bilayers.

X-ray diffraction and capacitance measurements have been used to calculate the depth to which water penetrates in fully hydrated bacterial phosphatidylethanolamine bilayers in the presence and absence of cholesterol. The data indicate that cholesterol decreases in depth of water penetration by about 2.5 angstroms.

Acute activation of Maxi-K channels (hSlo) by estradiol binding to the beta subunit.

Maxi-K channels consist of a pore-forming alpha subunit and a regulatory beta subunit, which confers the channel with a higher Ca(2+) sensitivity. Estradiol bound to the beta subunit and activated the Maxi-K channel (hSlo) only when both alpha and beta subunits were present. This activation was independent of the generation of intracellular signals and could be triggered by estradiol conjugated to a membrane-impenetrable carrier protein. This study documents the direct interaction of a hormone with a voltage-gated channel subunit and provides the molecular mechanism for the modulation of vascular smooth muscle Maxi-K channels by estrogens.

Transesophageal access to the cardiac cavities and descending thoracic aorta via echoendoscopy. An experimental study.

OBJECTIVE: The applications of endoscopic ultrasonography have diversified over recent years. The possibility of reaching cardiac territory has been successfully explored in experimental models, opening up a new field of possibilities for diagnostic and therapeutic interventions that were unthinkable until very recently. The aims set out in this study are to evaluate cardiac anatomy, its approach, the safety of the experimental procedure and the resulting morphological and histological changes after the procedure. MATERIAL AND METHODS: The study has been performed on two adult pigs. They have undergone different surgical approaches to the cardiac cavities and descending thoracic aorta with excellent results. RESULTS: Different cardiac structures have been identified and operated upon (right auricle, left auricle, left ventricle, cardiac valves), as well as major vessels. The use of contrast, both intracavitary and from a peripheral vein, enabled us to verify the anatomical spaces studied. During the procedures we monitored for arrhythmias, hemodynamic behavior, possibility of infection by obtaining sample hemocultures before and after procedures, and response to punctures. CONCLUSIONS: The present study has enabled us to evaluate access to the heart from the esophageal lumen using endoscopic ultrasonography, with results that are very similar to those described in the current bibliography. However, we offer two novelties: puncture of the right auricle through the interauricular partition and puncture of the descending thoracic aorta, both performed with ease and apparent safety.

Internal blockade of a Ca(2+)-activated K+ channel by Shaker B inactivating "ball" peptide.

Shaker B inactivating peptide ("ball peptide", BP) interacts with Ca(2+)-activated K+ (KCa) channels from the cytoplasmic side only, producing inhibition of channel activity. This effect was reversible and dose and voltage dependent (stronger at depolarized potentials). The inhibition of KCa channels by BP cannot be mimicked by an inactive point mutation of the BP, L7E. BP binds to KCa channels in a bimolecular reaction (dissociation constant of 95 microM at +40 mV). The binding site is probably located in the internal "mouth" or conduction pathway, since both external K+ and internal tetraethylammonium relieve BP-induced inhibition. These results suggest that KCa channels possess a binding site for the BP with some properties similar to the ball receptor found in Shaker B K+ channels.

Computed tomographic anatomy of the temporomandibular joint in the young horse.

REASONS FOR PERFORMING STUDY: The equine temporomandibular joint (TMJ) and its surrounding structures can be difficult to investigate in cases with a clinical problem related to the region. Little previous attention has been given either to a computed tomographic (CT) imaging protocol for the joint or an interpretation of the structures displayed in CT images of the normal joint. OBJECTIVES: To provide a CT atlas of the normal cross-sectional anatomy of the equine TMJ using frozen and plastinated sections as anatomical reference. METHODS: Eight TMJs from 4 immature pure-bred Spanish horses were examined by helical CT. Scans were processed with a detailed algorithm to enhance bony and soft tissue. Transverse CT images were reformatted into sagittal and dorsal planes. Transverse, sagittal and dorsal cryosections were then obtained, photographed and plastinated. Relevant anatomic structures were identified in the CT images and corresponding anatomical sections. RESULTS: In the CT images, a bone window provided excellent bone detail, however, the soft tissue components of the TMJ were not as well visualised using a soft tissue window. The articular cartilage was observed as a hyperattenuating stripe over the low attenuated subchondral bone and good delineation was obtained between cortex and medulla. The tympanic and petrous part of the temporal bone (middle and inner ear) and the temporohyoid joint were seen in close proximity to the TMJ. CONCLUSIONS: Helical CT provided excellent images of the TMJ bone components to characterise the CT anatomy of the normal joint. POTENTIAL RELEVANCE: Detailed information is provided that may be used as a reference by equine veterinarians for the CT investigation of the equine TMJ and serve to assist them in the diagnosis of disorders of the TMJ and related structures (middle and inner ear). The study was performed at an immature stage and further studies of mature individuals are required in order to confirm that the clinical interpretation is not affected by changes occurring with age.

In search of clinical truths: equine and comparative studies of anatomy.

The importance of correlating anatomical studies with diagnostic and therapeutic approaches in practice has long been recognised. Such studies in the horse have, until recently, lagged behind this discipline in human medicine and surgery. Clinical techniques by which this correlation is achieved include radiography, ultrasound, computed tomography and magnetic resonance imaging. This review presents published literature on the subject and, in addition, describes the part played by plastination, a recently developed technique for the preservation of biological specimens. In this, tissue fluids and part of the lipids are replaced by certain polymers yielding specimens that can be handled without gloves, do not smell or decay, and even retain microscopic properties of the original sample. The technique has proved to be a useful tool to correct previously presented anatomical descriptions and is one now favoured by human surgeons. Studies of the horse employing this technique include those of the temporomandibular joint and tarsus. The aim of the review is to stimulate further correlations of anatomical structure and equine medical and surgical procedures, thereby advancing knowledge and understanding in practice and teaching.

Double-balloon enteroscopy in two dogs.

It is difficult to insert a flexible endoscope deep into the small intestine. A new method, double-balloon enteroscopy, has been developed to improve access to the small intestine, and the aim of this study was to evaluate its usefulness for examination of the small intestine of dogs. The method uses two balloons, one attached to the tip of the endoscope and another attached to the tip of an overtube. The double-balloon endoscope is advanced through the intestine by being held alternately by the balloon on the endoscope and the balloon on the overtube. The technique was applied in two dogs of medium size, using both oral and anal approaches, and it was possible to examine the whole surface of the mucosa of their small intestines.