Morphologic variations in the pineal gland of the albino rat after a chronic alcoholisation process.

We studied the effect of alcohol on the pineal gland of 48 male Wistar rats. Animals were divided into control and experimental groups. The experimental group underwent a previous progressive alcoholisation period with ethanol diluted in water at a concentration of 40%. Animals were sacrificed at 3, 6, 9 and 12 months, and the ultrastructure, karyometric indices, and number of synaptic bodies in the pineal gland were analysed. The results showed progressive morphologic alterations in the ethanol-treated animals, which culminated in fatty degeneration of the pineal parenchyma after 6 months. The karyometric indices decreased in both the central and peripheral areas compared with the control group. Moreover, the seasonal rhythmicity observed in the controls disappeared in the experimental groups, whose number of different populations of synaptic bodies (synaptic ribbons and synaptic spherules) considerably lowered with inversion of their normal seasonal rhythm. These results support that chronic alcoholisation leads to fatty degeneration of the pineal parenchyma, and a considerable alteration in nuclear functional rhythms and synaptic bodies.

Importance of the Moskowitz artery in the laparoscopic medial approach to splenic flexure mobilization: a cadaveric study.

BACKGROUND: The medial approach in laparoscopic splenic flexure mobilization is based on the entrance to the lesser sac just above the ventral edge of the pancreas (VEOP). The artery of Moskowitz runs through the base of the mesocolon, just above the VEOP. The aim of this study was to assess the incidence of the artery of Moskowitz, its route and its distance from the VEOP. METHODS: We performed a cadaveric study on 27 human cadavers. The vascular arcades of the splenic flexure were dissected, the number of vascular arches, and the origin and localization of its terminal anastomosis were recorded. The splenic flexure avascular space (SFAS) was defined as the avascular zone in the mesocolon delimited by the VEOP, middle colic artery, ascending branch of the left colic artery and the vascular arch of the splenic flexure nearest to the VEOP and was quantified as the distance between the VEOP and the most proximal arch RESULTS: The artery of Drummond was identified in 100% of the cadavers. In 5 of 27 (18%) Riolan's arch was present, and in 3 of 27 (11%) the Moskowitz artery was found. The mean distance from the VEOP to the artery of Moskowitz was 0.3 cm (SD 0.04). This vascular arch travelled from the origin of the middle colic artery to the distal third of the ascending branch of the left colic artery. The SFAS was greater (p = 0.001) in cadavers that only presented the artery of Drummond (mean 6.8 cm; SD 1.25) than in those with Riolan's arch (mean 4.5 cm; SD 0.5) CONCLUSIONS: In the medial approach for laparoscopic mobilization of the splenic flexure, when only one of the arches is present, the avascular area is an extensive and secure territory. If the artery of Moskowitz is present, the area is nonexistent and this would contraindicate the approach due to risk of iatrogenic bleeding. A radiological preoperatory study could be essential for accurate and safe surgery in this area.

Propuesta de metodología docente en vía aérea difícil. Presentación de un modelo interactivo de cadáver fresco congelado / Proposed difficult airway teaching methodology. Presentation of an interactive fresh frozen cadaver model

Antecedentes y objetivo. El objetivo del trabajo es presentar una metodología basada en el empleo de los cadáveres frescos congelados para el entrenamiento de las habilidades en el tratamiento de la vía aérea y presentar el grado de satisfacción entre los alumnos. Material y métodos. Sobre 6 cadáveres frescos congelados se estructuraron 14 estaciones de trabajo en las que los alumnos entrenaron las diferentes habilidades necesarias para el tratamiento de la vía aérea. Se explican los detalles de preparación de los cadáveres que resultan fundamentales para un adecuado trabajo. Se evaluó el grado de satisfacción de los alumnos mediante la escala de evaluación de Likert de 5 puntos sobre las 14 estaciones, la valoración global y la utilidad clínica del curso. Resultados. La valoración global y la utilidad media del curso fueron de 4,75 y 4,9 sobre 5, respectivamente. Todas las partes del curso fueron valoradas por encima de 4 sobre 5. La elevada satisfacción sobre el curso se mantuvo homogénea en las 2 ediciones analizadas. La satisfacción global del curso no fue definitiva e unívocamente determinada por ninguna de sus partes en especial. Conclusión. El modelo de cadáver fresco para el entrenamiento de los médicos en técnicas de manejo de la vía aérea constituye una propuesta docente satisfactoria para el alumno, y con un realismo que se aproxima al paciente vivo (AU)

Background and objective. The aim of this paper is to present a methodology based on the use of fresh-frozen cadavers for training in the management of the airway, and to evaluate the degree of satisfaction among learning physicians. Material and methods. About 6 fresh-frozen cadavers and 14 workstations were prepared where participants were trained in the different skills needed for airway management. The details of preparation of the cadavers are described. The level of satisfaction of the participant was determined using a Likert rating scale of 5 points, at each of the 14 stations, as well as the overall assessment and clinical usefulness of the course. Results. The mean overall evaluation of the course and its usefulness was 4.75 and 4.9, out of 5, respectively. All parts of the course were rated above 4 out of 5. The high level of satisfaction of the course remained homogeneous in the 2 editions analysed. The overall satisfaction of the course was not finally and uniquely determined by any of its particular parts. Conclusion. The fresh cadaver model for training physicians in techniques of airway management is a proposal satisfactory to the participant, and with a realism that approaches the live patient (AU)

[Proposed difficult airway teaching methodology. Presentation of an interactive fresh frozen cadaver model]. / Propuesta de metodología docente en vía aérea difícil. Presentación de un modelo interactivo de cadáver fresco congelado.

BACKGROUND AND OBJECTIVE: The aim of this paper is to present a methodology based on the use of fresh-frozen cadavers for training in the management of the airway, and to evaluate the degree of satisfaction among learning physicians. MATERIAL AND METHODS: About 6 fresh-frozen cadavers and 14 workstations were prepared where participants were trained in the different skills needed for airway management. The details of preparation of the cadavers are described. The level of satisfaction of the participant was determined using a Likert rating scale of 5 points, at each of the 14 stations, as well as the overall assessment and clinical usefulness of the course. RESULTS: The mean overall evaluation of the course and its usefulness was 4.75 and 4.9, out of 5, respectively. All parts of the course were rated above 4 out of 5. The high level of satisfaction of the course remained homogeneous in the 2 editions analysed. The overall satisfaction of the course was not finally and uniquely determined by any of its particular parts. CONCLUSION: The fresh cadaver model for training physicians in techniques of airway management is a proposal satisfactory to the participant, and with a realism that approaches the live patient.

Efficacy of three drugs for protecting against gentamicin-induced hair cell and hearing losses.

BACKGROUND AND PURPOSE Exposure to an ototoxic level of an aminoglycoside can result in hearing loss. In this we study investigated the otoprotective efficacy of dexamethasone (DXM), melatonin (MLT) and tacrolimus (TCR) in gentamicin (GM)-treated animals and cultures. EXPERIMENTAL APPROACH Wistar rats were divided into controls (treated with saline); exposed to GM only (GM); and three GM-exposed groups treated with either DXM, MLT or TCR. Auditory function and cochlear surface preparations were studied. In vitro studies of oxidative stress, pro-inflammatory cytokine mRNA levels, the MAPK pathway and caspase-3 activation were performed in organ of Corti explants from 3-day-old rats. KEY RESULTS DXM, MLT and TCR decreased levels of reactive oxygen species in GM-exposed explants. The mRNA levels of TNF-α, IL-1ß and TNF-receptor type 1 were significantly reduced in GM + DXM and GM + MLT groups. Phospho-p38 MAPK levels decreased in GM + MLT and GM + TCR groups, while JNK phosphorylation was reduced in GM + DXM and GM + MLT groups. Caspase-3 activation decreased in GM + DXM, GM + MLT and GM + TCR groups. These results were consistent with in vivo results. Local treatment of GM-exposed rat cochleae with either DXM, MLT or TCR preserved auditory function and prevented auditory hair cell loss. CONCLUSIONS AND IMPLICATIONS In organ of Corti explants, GM increased oxidative stress and initiated an inflammatory response that led to the activation of MAPKs and apoptosis of hair cells. The three compounds tested demonstrated otoprotective properties that could be beneficial in the treatment of ototoxicity-induced hearing loss.

Review of the anatomic concepts in relation to the retrorectal space and endopelvic fascia: Waldeyer's fascia and the rectosacral fascia.

OBJECTIVE: A precise anatomical study of the fascias within the retrorectal space is reported, analyzing and clarifying the anatomical concepts previously employed to describe Waldeyer's and the rectosacral fascia. METHOD: The pelvis was dissected in 15 cadavers (10 males and five females). All specimens were divided in the median sagittal plane including the middle axis of the anal canal, to allow a correct visualization of and access to the retrorectal space. RESULTS: The retrorectal space was limited anteriorly by the rectum and posterior mesorectum covered by a fine visceral fascia, and posteriorly by the sacrum covered by the parietal presacral fascia. The rectosacral fascia divided the retrorectal space into inferior and superior portions in 80% of the male and 100% of the female specimens. It originated from the presacral parietal fascia at the level of S2 in 15%, S3 in 38% and S4 in 46% of specimens. In all cases it passed caudally to join the rectal visceral fascia 3-5 cm above the anorectal junction. As described by Waldeyer, the floor of the retrorectal space is formed by the fusion of the presacral parietal fascia and the rectal visceral fascia and lies above the levator ani muscle at the level of the anorectal junction. CONCLUSION: The rectosacral fascia divides the retrorectal space into inferior and superior portions. This must be differentiated from Waldeyer's description of the fascia lying in the inferior limit of the retrorectal space, formed by the fusion of the rectal visceral and parietal fascias.

Effect of contact lens wear on the anatomic values of the corneal thickness

The aim was to analyze the changes in centralcorneal thickness values due to soft contact lens wear. We analyzed the central corneal thickness values (baseline measurements) of 15 myopic adolescent soft contact lens wearers (15 eyes; aged 15 to 16 years old). Three years later, the central corneal thickness wasmeasured again. We also measured the central corneal thickness of 31 myopic adolescents who did not use contact lenses (31 eyes; aged 15 to 16 years old) and 34 myopic contact lens wearers aged between 25 and 40 yearsold (34 eyes). We obtained the mean of fivemeasurements using the Orbscan Topography System II (Orbscan, Inc., Salt Lake City, UT,USA). In the later measurements (three years)there was a significant decrease in the central corneal thickness values (p=0.012) of the adolescent contact lens wearers and the contact lens subjects aged 25 to 40 years old(p<0.001). This decrease was not found in theadolescent non-contact lens wearers (p=0.476). The central corneal thickness values of the adolescent contact lens wearers were significantly lower than the baseline values up to four weeks after removal of theircontact lenses (p=0.201). In conclusion, therewas a significant reduction in the anatomic values of corneal thickness associated with soft contact lens wearers, although baseline thickness values recovered to normal levels approximately one month after the use of contact lenses had ceased (AU)

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Anatomic differences between a normal and two keratoconus corneas

Keratoconus is an anatomic deformity of the cornea characterized by progressive thinning and a cone-shaped protrusion of the central cornea. Thinning corneal disorders, such as keratoconus, should be identified before excimer laser refractive surgery.An Orbscan System (Orbscan Corneal Topography System II, Orbscan Inc., Salt Lake City, UT, USA) was used to analyse and compare corneal thickness values and the anterior and posterior corneal elevation maps of three subjects who wished to undergo excimer laser refractive surgery. The quantitative differences between the minimum thickness value of the entire cornea and the values obtained in the central and paracentral cornea of the subjects were also analysed.Analysis of corneal thicknessess revealed that normal corneas had higher central and paracentral values. Greater differences were found between the thinnest site of the entire cornea and the paracentral areas in the keratoconic corneas than in the normal cornea. Thecone-shaped protrusion was detected in the anterior and posterior corneal elevation maps of one subject but only in the posterior elevation map of the other keratoconus subject.The detection of corneal anatomic deformities,such as keratoconus, should include the analysisof corneal thickness values and the analysisof both anterior and posterior corneal elevationmaps (AU)

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Quantitative ocular anatomy in vivo: comparison of axial length and anterior chamber depth values obtained by a single observer by means of optical biometry and immersion and applanation ultrasound biometry

The aim of the present work was to analyzeand compare axial length and anterior chamberdepth values obtained by means of IOLMaster™, immersion and applanationultrasound. Axial length and the anteriorchamber depth measurements were carriedout by a single observer in 30 volunteers(n=30; mean age, 68±10.7 years of age; range44 to 83 years) using IOLMaster™ (ZeissHumphrey System, CA, USA), immersion andapplanation ultrasound biometry. Ultrasoundmeasurements were carried out with the CompuscanA-B Storz (San Louis, MO, USA). TheIOLMaster™ provided axial length measurementsthat were 0.04 mm (p=0.936) and 0.13mm (p=0.606) higher than those fromimmersion and applanation ultrasound respectively.The mean difference between the opticaland applanation measurements was -0.11mm, and -0.03 mm between the optical andimmersion measurements. In conclusion,there are no significant differences betweenIOLMaster™, immersion and applanationultrasound axial length and anterior chamberdepth values (AU)

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Morphometric differences between normal and dry eyes

The aim of the study was to quantify the anatomicdifferences in central corneal thickness, anteriorocular chamber depth, lens thickness, vitreouschamber depth, and ocular axial length betweennormal and dry-eyes. Central corneal thickness(CCT), ocular anterior chamber depth (ACD), lensthickness (LT), vitreous chamber depth (VCD)and ocular axial length (AL) were measured in 70normal subjects and in 58 subjects with dry-eyes.Central corneal thickness was measured withscanning-slit corneal topography while ocularanterior chamber depth, lens thickness, vitreouschamber depth and ocular axial length were measuredwith applanation ultrasound biometry.Central corneal thickness was 0.558±0.30 mmand 0.532±0.34 mm in normal and dry-eyes,respectively (p<0.001). Mean ocular anteriorchamber depth was 3.17±0.23 mm and 2.93±0.35mm in normal and dry-eyes, respectively(p=0.002). Lens thickness was 4.49±0.42 mm inthe dry-eye patients and 4.71±0.32 mm in thenormal subjects (p=0.022). Vitreous chamberdepth was 16.75±1.75 mm and 15.54±1.34 mm innormal and dry-eyes, respectively (p=0.001).Ocular axial length was 24.58±1.73 in normalsubjects and 23.07±1.48 in dry-eye subjects(p<0.001). We conclude that quantitative ocularanatomy values are lower in dry-eye subjects (AU)

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Quantitative central corneal anatomy and anaesthetic eye drops effects: Comparison between 0.4% oxybuprocaine and a combination of 0.1% tetracaine and 0.4% oxybuprocaine

We aimed to analyse the changes in central cornealthickness values following the instillation of0.4% oxybuprocaine eye drops and following acombination of 0.1% tetracaine and 0.4% oxybuprocaineeye drops.Orbscan pachymetry (Orbscan II CornealTopography System; Orbscan, Inc., Salt LakeCity, UT, USA) was carried out before andthree minutes after the instillation of 0.4% oxybuprocaineeye drops, and before and threeminutes after the instillation of a combinationof 0.1% tetracaine and 0.4% oxybuprocaine eyedrops in 35 healthy subjects (n=35; aged 20-30years). After the instillation of 0.4% oxybuprocaineeye drops there was a mean increase incentral corneal thickness of 25±11 microns.After the combination of 0.1% tetracaine and0.4% oxybuprocaine eye drops it rose to 48±20microns. The combination of 0.1% tetracaineand 0.4% oxybuprocaine anaesthetic eye dropscauses higher increases in central cornealthickness values than 0.4% oxybuprocaine eyedrops (AU)

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Corneal endothelial cell density decreases with age in emmetropic eyes.

PURPOSE: To analyze the corneal endothelial cell density in healthy adult emmetropic subjects. METHODS: We analyzed the corneal endothelial cell density of a group made up of 225 emmetropic subjects (n=225). As age-matched control groups we analyzed two other groups, one made up of myopic subjects (n=209) and the other made up of hyperopic subjects (n=203). We recorded the mean of three consecutive measurements of the corneal endothelial cell density using the Topcon SP-2000P non-contact specular microscope (Topcon Corp., Tokyo, Japan). RESULTS: The mean age was 38.6+/-11.8 years, 40.7+/-12.2 years, and 39.2+/-10.5 years for emmetropic, myopic and hyperopic subjects respectively (p=0.994). No significant differences (p=0.920) in endothelial cell density values were found between emmetropic (2985+/-245 cells/mm2), myopic (2936+/-258 cells/mm2) and hyperopic eyes (2946+/-253 cells/mm2). Lower corneal endothelial cell density values were found in older emmetropic (p<0.001), myopic (p<0.001), and hyperopic subjects (p<0.001). A significant correlation between endothelial cell density and age was found in emmetropic (r=-0.958; p<0.001), myopic (r= -0.954; p<0.001) and hyperopic subjects (r= -0.948; p<0.001). CONCLUSIONS: In healthy emmetropic subjects there is a reduction in corneal endothelial cell density with age although there are no differences in corneal endothelial cell density values between emmetropic, myopic and hyperopic subjects.

Gender differences in corneal thickness values

The aim was to study gender differences in corneal thickness. We analysed the corneal thickness of 100 corneas of 100 healthy subjects (mean age 30.87±7.76 years; range, 19 to 54 years old) with the Orbscan Topography System II (Orbscan, Inc., Salt Lake City, UT. USA). The means of five consecutive measurements of the central and paracentral corneal thickness were obtained. No significant differences in mean corneal thickness between women and men at central (p=0.477), nasal (p=0.247), superonasal (p=0.242), inferonasal (p=0.554), temporal (p=0.538), superotemporal (p=0.524) and inferotemporal (p=0.860) corneal locations were found. In sum, there are no differences in mean central and paracentral corneal thickness values between women and men (AU)

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The effect of a combination of 0.1% tetracaine HCl and 0.4% oxybuprocaine HCl on human central corneal thickness measurements

A combination of 0.1% tetracaine HCl and 0.4% oxybuprocaine HCl is used when carrying out morphometrical corneal studies in vivo by means of ultrasound pachymetry. The aim of this was to determine the effect of a combination of 0.1% tetracaine HCl and 0.4% oxybuprocaine HCl anesthetic eye drops on central corneal thickness values. We carried out a prospective study involving 30 eyes of 30 healthy subjects. The mean age of the subjects was 26.13±2.62 years (age ranged from 20 to 30 years old). Central pachymetry was carried out prior to and three minutes after the instillation of two saline solution eye drops, and three minutes after the administration of a combination of 0.1% tetracaine HCl and 0.4% oxybuprocaine HCl anesthetic eye drops. The mean of three consecutive measurements of the central corneal thickness obtained with the Orbscan Topography System II (Orbscan, Inc., Salt Lake City, UT. USA) was used as the corneal thickness value. No significant differences were found (p=0.714) in the mean central corneal thickness values before and three minutes after saline solution eye drops had been instilled. Nevertheless, after anesthesia there was a significant increase in mean central corneal thickness (p<0.001). Increases ranged from 22 to 131 micrometers, with a mean of approximately 47 micrometers. Following the instillation of a combination of 0.1% tetracaine HCl and 0.4% oxybuprocaine HCl eye drops corneal thickness increase. Researchers must be aware of this effect of topical anesthetic eye drops on corneal morphometry in order to analyze corneal thickness results correctly (AU)

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Intraobserver reproducibility of retinal nerve fiber layer measurements using scanning laser polarimetry and optical coherence tomography in normal and ocular hypertensive subjects.

PURPOSE: To evaluate quantitatively the intraobserver reproducibility of measurements of the retinal nerve fiber layer (RNFL) in healthy subjects and an ocular hypertensive population using two nerve fiber analyzers. METHODS: Sixty eyes of normal (n=30) and ocular hypertensive subjects (n=30) were consecutively recruited for this study and underwent a complete ophthalmologic examination and achromatic automated perimetry. RNFL were measured using scanning laser polarimeter (GDx-VCC) and optical coherence tomography (OCT Model 3000). Reproducibility of the RNFL measurements obtained with both nerve fiber analyzers were compared using the coefficient of variation. RESULTS: In both groups the authors found fair correlations between the two methods in all ratio and thickness parameters. The mean coefficient of variation for measurement of the variables ranged from 2.24% to 13.12% for GDx-VCC, and from 5.01% to 9.24% for OCT Model 3000. The authors could not detect any significant differences between healthy and ocular hypertensive eyes, although in normal eyes the correlations improved slightly. Nevertheless, the test-retest correlation was slightly better for GDx-VCC than for OCT Model 3000 (5.55% and 7.11%, respectively). CONCLUSIONS: Retinal mapping software of both nerve fiber analyzers allows reproducible measurement of RNFL in both healthy subjects and ocular hypertensive eyes, and shows fair correlations and good intraobserver reproducibility. However, in our study, GDx showed a better test-retest correlation.

Human corneal thickness using a noncontact specular microscope

The aim of this work was to study the central corneal thickness values and interobserver variability using a noncontact specular microscope. Methods: 62 eyes from 31 healthy subjects were studied with the Topcon SP-2000P noncontact specular microscope (Topcon Corp., Tokyo, Japan). 16 (51.61%) were females, and 15 (48.38%) were males. The mean age of the sample was 31.83±5.68 years. The mean of three consecutive measurements of the central corneal thickness was recorded by two investigators. Results: Mean central corneal thickness was 497±53 ?m for physician I and 497±51 ?m for physician II (p=0.982). No significant differences were found between the left and right corneas (p=0.999), between females and males (p=0.756), between ? 29-years-olds and ? 30-years-olds (p=0.945) or between myopic and hyperopic eyes (p=0.994). Conclusion: Noncontact specular microscopy is a recently introduced anatomical tool that can be used to study the human cornea in vivo (AU)

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