Mytilus galloprovincialis releases immunologically functional haemocytes to the intervalvar space in response to tissue injury and infection.

Haemocytes of Mytilus galloprovincialis represent the main component of the internal self-defence system. Although haemocytes from haemolymph are usually studied to analyse these animals' immune response, the presence of haemocytes in the intervalvar liquid, which is essentially sea water, led us to characterize them. Several functional (ROS production, phagocytosis, gene expression, travel velocity and distance) and morphological (area, size and granularity) assays were performed by applying different stimuli to the mussels (waterborne infection, shell injury and their combination). Our results revealed that intervalvar liquid haemocytes share common characteristics with haemolymph haemocytes (for instance, the cell morphology and the cell population structure divided in three main groups) but also show significant differences in size (usually smaller in the intervalvar liquid), mobility (commonly faster in the intervalvar liquid), ROS production (higher in non-stimulated intervalvar liquid cells) and gene expression (IL17, Myd88 and CathL are over expressed in liquid intervalvar cells compared to haemolymph cells). Moreover, differences were observed when mussels were subjected to the mentioned treatments. These free intervalvar haemocytes could constitute the first line of defence as external sentinels extending the immunological alert system outside of the mussel body.

Effects of short-term hyposalinity stress on four commercially important bivalves: A proteomic perspective.

Increased heavy rainfall can reduce salinity to values close to 0 in estuaries. Lethal and sublethal physiological and behavioural effects of decreases in salinity below ten have already been found to occur in the commercially important clam species Venerupis corrugata, Ruditapes decussatus and R. philippinarum and the cockle Cerastoderma edule, which generate an income of ∼74 million euros annually in Galicia (NW Spain). However, studies of the molecular response to hyposaline stress in bivalves are scarce. This 'shotgun' proteomics study evaluates changes in mantle-edge proteins subjected to short-term hyposaline episodes in two different months (March and May) during the gametogenic cycle. We found evidence that the mantle-edge proteome was more responsive to sampling time than to hyposalinity, strongly suggesting that reproductive stages condition the stress response. However, hyposalinity modulated proteome profiles in V. corrugata and C. edule in both months and R. philippinarum in May, involving proteins implicated in protein folding, redox homeostasis, detoxification, cytoskeleton modulation and the regulation of apoptotic, autophagic and lipid degradation pathways. However, proteins that are essential for an optimal osmotic stress response but which are highly energy demanding, such as chaperones, osmoprotectants and DNA repair factors, were found in small relative abundances. In both months in R. decussatus and in March in R. philippinarum, almost no differences between treatments were detected. Concordant trends in the relative abundance of stress response candidate proteins were also obtained in V. corrugata and C. edule in the different months, but not in Ruditapes spp., strongly suggesting that the osmotic stress response in bivalves is complex and possibly influenced by a combination of controlled (sampling time) and uncontrolled variables. In this paper, we report potential molecular targets for studying the response to osmotic stress, especially in the most osmosensitive native species C. edule and V. corrugata, and suggest factors to consider when searching for biomarkers of hyposaline stress in bivalves.

Mucoperiosteal exostoses in the tympanic bulla of African lions (Panthera leo).

Mucoperiosteal exostoses (MpEs) of the tympanic bulla (TB), also referred as middle-ear otoliths, have been occasionally described in dogs and cats in association with clinical signs of otitis media or as an incidental finding, but they have not been recorded in other species. In this report, we describe the radiographic, gross, and histopathologic features of MpEs in 8 African lions (Panthera leo). All animals (5 males and 3 females) were adults that had been kept in captivity and had their skeletons conserved as part of an anatomic academic collection. A radiographic study revealed mineralized structures in the TB consistent with MpEs in 7 of the 16 examined TB; a computed tomography study identified MpEs in 12 of the 16 TB. Six TB from 4 lions were sectioned, and several MpEs were demineralized for histopathologic analysis. Grossly, MpEs appeared variable in number and shape. Some were globular structures that were loosely attached to the mucosal surface of the TB; others were isolated to coalescent bone spicules extending from the mucoperiosteum. Position was also variable, but MpEs frequently developed in the hypotympanum, especially on the ventromedial aspect of the TB wall. Microscopically, MpEs were composed of osteonal bone growing from the periosteum and not by dystrophic calcification of necrotic tissue debris, as is hypothesized in dogs.

Morphometric changes in the dog trochlear nerve with growth.

The objective of this work was to analyse changes in morphometric characteristics related to growth in the trochlear nerve in dogs. Twenty beagles, split into four dog age groups (A, 7 days; B, 21 days; C, 35 days; D, 49 days and E, 4 years), were used. The right intracranial portion of the nerve was analysed by light and electron microscopy. The nerve cross-sectional area was calculated. Number, diameter and cross-sectional area of unmyelinated and myelinated fibres were also calculated. In myelinated fibres, the corresponding axon area and diameter and myelin sheath thickness were also calculated. The number of myelinated and unmyelinated fibres was 1070.25±112.07 and 592.25±467.53 in group A, 1367±57.98 and 143.67±54.37 in group B, 1574.20±299.50 and 151.67±51.73 in group C, 1340.33±151 and 127±48.75 in group D and 1476±260.71 and 284±101.82 in group E. The mean diameter for myelinated and unmyelinated fibres was 4.37±0.17 µm and 0.41±0.08 µm for group A; 6.21±0.12 µm and 0.30±0.03 µm for B; 6.90±0.91 µm and 0.32±0.03 µm for C; 7.86±1.19 µm and 0.32±0.02 µm for D; 10.63±0.50 µm and 0.30±0.01 µm for E, respectively. This nerve possesses similar structural and ultrastructural features to the same nerve in other species and modifies its morphometry with growth. Results could enhance the understanding of pathological disorders.

Proteomic evidence of a paedomorphic evolutionary process within a marine snail species: a strategy for adapting to extreme ecological conditions?

The exposed and sheltered ecotypes of the marine snail Littorina saxatilis from European rocky shores are considered a key model system to study adaptation and ecological speciation. Previous studies showed that two ecotypes (RB and SU) of this species in NW Spain have adapted differently to different shore levels and microhabitats. In order to understand how this divergent adaptive process has been accomplished, we followed a quantitative proteomic approach to investigate the proteome variation in a number of different biological factors, that is, ecotype, ontogeny and their interactions. This approach allowed testing the hypothesis that one of the ecotypes has evolved by paedomorphosis, and also whether or not the molecular mechanisms related to ecotype differentiation are set up in early developmental stages. Additionally, the identification of some candidate proteins using mass spectrometry provides some functional insights into these evolutionary processes. Results from this study provided evidence of higher ontogenetic differentiation at proteome level in the RB (metamorphic) than in SU (paedomorphic) ecotype that point to the possibility of juvenile stage retention in this latter ecotype. The level of protein expression (proteome) differences between ecotypes maintained nearly constant from late embryonic stages to adulthood, although some proteins involved in these changes considerably differed in embryonic compared to other ontogenetic stages. Paedomorphosis may be the evolutionary response of the SU ecotype of solving the trade-off during sexually immaturity that is caused by the evolution of small size arising from adaptation to the wave-exposed habitat. Some potential candidate genes of adaptation related to energetic metabolism have been identified, providing a promising baseline for future functional analyses.

Peripheral insertion of double-lumen central venous catheter using the Seldinger technique in newborns.

OBJECTIVE: To report the experience of peripheral insertion of double-lumen central catheters (PIDLCC) in preterm and term newborn infants and to analyze the technical characteristics of the procedure and any observed complications. STUDY DESIGN: Retrospective review of 61 newborns that had a PIDLCC between 2003 and 2006. The study comprised clinical data analysis, anthropometrics, indications, duration, complications and reasons for withdrawal of the catheters. RESULT: Weight of the patients was <1 kg in 10%, and >2 kg in 75%. Catheters tip placement was as aimed, mostly superior cava vein (SCV), in 65.5%, and subclavian vein in remaining 34.5% and average duration of catheterization was 13.5+/-9.6 and 8.9+/-5.8 days, respectively. Blood sampling through both lumens was possible especially when the tip was at SCV. Reasons for catheter withdrawal were end of indication (45.9%), phlebitis/edema (21.3%), suspected infection (3.2%), accidental withdrawal (3.2%) and rupture of proximal end (3.2%). In three (4.9%) patients, withdrawal was due to serious complications (two cases of pleural leakage of infusion fluid and one breakage of the metallic guide). About 16.3% of the patients died with the catheter still in situ. Infection findings were positive tip culture (14.7%) and catheter-related sepsis (3.2%). CONCLUSION: Insertion of PIDLCC is possible in neonates. The incidence of complications, mostly mechanical, requires careful evaluation of indications, and strict adherence to the procedure of insertion and manipulation.

Catéteres centrales en pediatría / Central catheters in pediatrics

Se estudian las indicaciones de la colocación de catéteres centrales en pediatría. Se describen las téncicas de colocación y retirada de los catéteres umbilicales en el neonato por vía venosa y arterial. Se detalla la canalización percutánea venosa central y la técnica de Seldinger para accesos vasculares centrales

The indications for placement of central catheters in pediatrics are studied. Venous and arterial placement and removal techniques of the umbilical catheters in the newborn are described. Central venous percutaneous canalization and the Seldinger technique for central vascular accesses are detailed

Structural and ultrastructural study of the intracranial portion of the oculomotor, trochlear and abducent nerves in dog.

The right intracranial portion of the oculomotor, trochlear and abducent nerves were removed from six adult German shepherd dogs and analysed by light and electron microscopy. In all cases the nerve sectional area was calculated. Unmyelinated and myelinated fibres were analysed and number, diameter and cross-sectional area were calculated. In myelinated fibres, also calculated were the corresponding axon area and diameter, and myelin sheath thickness. The mean number of myelinated fibres was 8543.50 +/- 1231.85 being the unmyelinated 1402 +/- 241.58 in the oculomotor nerve; 1509 +/- 223.17 and 287.67 +/- 72.28 in the trochlear nerve and 2473.00 +/- 211.41 and 231.25 +/- 92.67 respectively in the abducent. The mean diameter was 10.23 +/- 0.68 microm in myelinated and 0.43 +/- 0.21 for unmyelinated in oculomotor nerve, 10.53 +/- 0.55 microm and 0.33 +/- 0.04 for the trochlear, and 10.45 +/- 1.27 microm and 0.47 +/- 0.09 in the abducent nerve respectively. This study reveals that oculomotor, trochlear and abducent nerves of the dog show structural and ultra-structural features similar to the same nerves in other species.

[Effect of hygiene interventions on the thermal stability of extremely low-birth-weight newborns in the first two weeks of life]. / Repercusión del aseo en la estabilidad térmica del recién nacido de extremado bajo peso durante las primeras dos semanas de vida.

INTRODUCTION: A prospective study was performed of a cohort of extremely low-birth-weight (ELBW) premature neonates (birth weight 500 to 1,000 g) consecutively admitted to the neonatal intensive care unit. The aim of this study was to examine the thermal changes that occur during all the hygiene-related interventions in ELBW infants in the first 2 weeks of life. PATIENTS AND METHODS: The study was carried out for 10 consecutive months in the Neonatology Service of La Paz University Hospital. We studied all consecutively admitted ELBW infants who satisfied the following criteria: a) adequate weight for gestational age; b) survival for at least 1 week, and c) no major congenital malformations or dysmorphic features. The infants included in the study were managed according to a standard care protocol for maintaining thermal stability and preventing cold-induced stress. Central temperature (Tc) was measured in the axilla and peripheral temperature (Tp) was measured on the sole of the foot. Both temperatures were continuously monitored for a) a period of scheduled non-handling--baseline period--and b) during and after a series of "hygiene interventions". In each of these periods, Tc and Tp were continuously monitored and recorded at 10 min intervals for the first 30 minutes and then at 30 min intervals until completing a 180 min period. RESULTS: Although incubator temperature was raised by a mean of 3 degrees C during hygiene interventions, hygiene was accompanied by a change in body temperature that remained fairly constant throughout the study period; Tc and Tp decreased by a mean of 1 degrees C with respect to baseline temperature. A fall in axillary temperature to less than 36.5 degrees C was observed in 87.4 % of recordings and a fall to less than 36 degrees C was observed in 45.5 %; axillary temperature remained below 36.5 degrees C for a mean duration of almost 1 hour. The differential temperature (Td 5 Tc - Tp), an indicator of thermal stress, was more than 1 degrees C for a mean duration of more than 80 min and > 2 degrees C for more than 20 minutes in both the first and second weeks of life. CONCLUSIONS: During hygiene interventions, ELBW infants experienced a sharp fall in central and peripheral body temperature. After hygiene interventions, these neonates had a Td suggestive of prolonged thermal stress, despite the use of standardized care protocols designed to avoid or minimize the potential effects of hygiene interventions on neonatal temperature.

Repercusión del aseo en la estabilidad térmica del recién nacido de extremado bajo peso durante las primeras dos semanas de vida / Effect of hygiene interventions on the thermal stability of extremely low-birth-weight newborns in the first two weeks of life

El objetivo del estudio fue examinar los cambios térmicos que tienen lugar durante un conjunto de acciones agrupadas en relación con el aseo corporal en los RNEBP durante las primeras 2 semanas de vida. Pacientes y métodos. El estudio se realizó durante 10 meses consecutivos en el Servicio de Neonatología del Hospital Universitario La Paz. Se estudiaron todos los RNEBP ingresados consecutivamente que cumplieron los siguientes criterios: a) peso adecuado a la edad gestacional; b) sobrevivir al menos una semana, y c) no presentar malformaciones congénitas mayores o rasgos dismórficos. Los niños incluidos en el estudio fueron manejados según los protocolos de cuidado estándar dirigidos a mantener la estabilidad térmica y evitar el estrés por frío. La temperatura central (Tc) se midió en el hueco axilar y la periférica (Tp) en la planta de un pie. Ambas temperaturas se monitorizaron de forma continua durante: a) un período de no manipulación programada (período basal), y b) durante y después de un conjunto de intervenciones agrupadas que denominamos "aseo". Durante ambos períodos se monitorizaron de forma continua la Tc y la Tp, registrándose a intervalos de 10 min durante los primeros 30 min y posteriormente cada 30 min hasta completar un período de registro de 180 min. Resultados. A pesar que durante el aseo la temperatura de la incubadora se incrementó casi 3 °C por término medio, el aseo conllevó un patrón de cambio en la temperatura corporal similar durante todo el período de estudio; la Tc y la Tp descendieron aproximadamente 1 °C por término medio respecto a la temperatura basal. Se observó una caída de la temperatura axilar por debajo de 36,5 °C en el 87,4 % de los registros y por debajo de 36 °C en el 45,5 % y la temperatura axilar permaneció inferior a 36,5 °C durante prácticamente una hora por término medio. Además, la temperatura diferencial (Td 5 Tc ­ Tp), un indicador de estrés térmico, fue superior a 1 °C durante más de 80 min y a 2 °C durante más de 20 min por término medio, tanto en la primera como en la segunda semana de vida. Conclusiones. Durante el aseo de los RNEBP tiene lugar un marcado descenso de la temperatura corporal, tanto central como periférica. Tras el aseo, estos recién nacidos presentan una Td indicativa de estrés térmico, durante períodos prolongados. Estos cambios térmicos tienen lugar aun siguiendo protocolos de aseo estandarizados dirigidos a evitar o aminorar la potencial repercusión de este en la temperatura del recién nacido

Introduction. A prospective study was performed of a cohort of extremely low-birth-weight (ELBW) premature neonates (birth weight 500 to 1,000 g) consecutively admitted to the neonatal intensive care unit. The aim of this study was to examine the thermal changes that occur during all the hygiene-related interventions in ELBW infants in the first 2 weeks of life. Patients and methods. The study was carried out for 10 consecutive months in the Neonatology Service of La Paz University Hospital. We studied all consecutively admitted ELBW infants who satisfied the following criteria: a) adequate weight for gestational age; b) survival for at least 1 week, and c) no major congenital malformations or dysmorphic features. The infants included in the study were managed according to a standard care protocol for maintaining thermal stability and preventing cold-induced stress. Central temperature (Tc) was measured in the axilla and peripheral temperature (Tp) was measured on the sole of the foot. Both temperatures were continuously monitored for a) a period of scheduled non-handling ­baseline period­ and b) during and after a series of "hygiene interventions". In each of these periods, Tc and Tp were continuously monitored and recorded at 10 min intervals for the first 30 minutes and then at 30 min intervals until completing a 180 min period. Results. Although incubator temperature was raised by a mean of 3 °C during hygiene interventions, hygiene was accompanied by a change in body temperature that remained fairly constant throughout the study period; Tc and Tp decreased by a mean of 1 °C with respect to baseline temperature. A fall in axillary temperature to less than 36.5 °C was observed in 87.4 % of recordings and a fall to less than 36 °C was observed in 45.5 %; axillary temperature remained below 36.5 °C for a mean duration of almost 1 hour. The differential temperature (Td 5 Tc ­ Tp), an indicator of thermal stress, was more than 1 °C for a mean duration of more than 80 min and > 2 °C for more than 20 minutes in both the first and second weeks of life. Conclusions. During hygiene interventions, ELBW infants experienced a sharp fall in central and peripheral body temperature. After hygiene interventions, these neonates had a Td suggestive of prolonged thermal stress, despite the use of standardized care protocols designed to avoid or minimize the potential effects of hygiene interventions on neonatal temperature

Análisis morfométrico de las fibras nerviosas del nervio abducente del perro / Morphometric analysis of the nerve fibers of the abducent nerve in dog

Para nuestro estudio hemos analizado la porción intracraneal de los nervios abducentes derechos extraídosde seis perros adultos, de raza pastor alemán. Los nervios fueron analizados con microscopia óptica y microscopiaelectrónica. En todos los nervios hemos calculado su área y analizado las fi bras mielínicas y amielínicas.En ambos tipos de fibras hemos determinado su número, diámetro y área, así como el área y el diámetro delaxón correspondiente y el grosor de la vaina de mielina en las fibras mielínicas. El número medio de fibras esde 2473,00 ± 211,41 mielínicas y 231,25 ± 92,67 amielínicas. El diámetro medio fibrilar fue de 10,45 ± 1,27 mm para las fibras mielínicas y 0,47 ± 0,09 mm para las amielínicas. Nuestro estudio sobre el nervio abducentemuestra que este nervio, en el perro, presenta características estructurales y ultraestructurales semejantes a la de otros nervios y otras especies

The intracranial portion of the abducent nerve was studied in dogs. The nerves were dissected from sixadult German shepherd dogs. The nerves were analysed by both light and electron microscopy. In all nerveswe calculated their area and analysed both myelinated and unmyelinated fibers. In both we determined theirnumber, diameter and area; also the area and diameter of the correspondent axon, and the thickness of the myelinsheath. The mean number of fibers was 2473.00±211.41 for myelinated and 231.25±92.67 for unmyelinatedones. The average fiber diameter was 10.45±1.27 mm for myelinated and 0.47±0.09 mm for unmyelinated. Thisstudy on the abducent nerve demonstrated that dogs shows structural and ultrastructural characteristics similartothose of another nerves and other species

Estudio estructural y ultraestructural de la porción intracraneal del nervio troclear del perro / Structural and ultrastructural study the intracranial portion of the trochlear nerve in the dog

En el presente trabajo se han extraído, de seis perros adultos, de 40-50 kilogramos de peso, los nervios trocleares derechos en su porción intracraneal. Los nervios fueron analizados con microscopia óptica y microscopia electrónica. Hay que destacar la presencia de fibras no mielinizadas en todos los nervios analizados. De las fibras mielinizadas hemos determinado su número, diámetro, área y densidad , así como el área y el diámetro del axón correspondiente y el grosor de la vaina de mielina. El número medio de fibras mielínicas contabilizadas fue de 1482,25. El histograma de frecuencias relativo al grosor de la vaina de mielina y al tamaño fibrilar muestran una distribución bimodal, siendo 10,8 μm el valor medio de discriminación de las dos poblaciones fibrilares. Se aprecia una proporción similar de fibras grandes (47,45%) y pequeñas (52,55%). La población de fibras pequeñas presentan un tamaño medio de 6,44 μm y ocupan un 12,10% de la superficie total del nervio, por el contrario las fibras grandes, con un tamaño medio de 15,34 μm ocupan el 60,20% del nervio (AU)

In the present investigation, the right intracranial portion of the trochlear nerves was removed from six adult dogs weighing 40-50 kg and analyzed by light and electron microscopy. A significant number of unmyelinated fibers were observed in the analyzed nerves. Number, diameter, area and density of myelinated fibers were determined as were corresponding axon area and diameter and myelin sheath thickness. Myelinated fibers count produced a mean of 1482,25. Frequency histograms of myelin sheath thickness and fiber size show a bimodal distribution being 10,8 μm the mean value of discrimination of the two populations. A similar proportion of large (47,45%) and small fibers (52,55%) is appraised. The small fibers population was present in a size mean of 6,44 μm and occupies a 12,10% of the total surface of the nerve, on the contrary the large fibers, with size mean of 15,34 μm ocupy a 60,20% of the nerve (AU)

Changes due to age in the kinematics of trotting Andalusian foals.

The purpose of this study was to evaluate the effect of growth on biokinematic characteristics at the trot in a group of 9 Andalusian foals from age 12 to 36 months in order to identify which stride variables change or remain invariable. Biokinematic analysis was performed by using a computer-assisted videography system (25 Hz frame rate). An increase in stride length as well as the fore- and hindlimb stride duration was found. A tendency to increase flexion of the shoulder, elbow and carpal joints was observed while the forelimb fetlock increased its maximal extension. In the hindlimb, most of the differences were exhibited by the hip and stifle joints, which showed a tendency to a lesser flexion with age. However, at landing the extension was bigger. The hindlimb fetlock extended more in older foals, whereas flexion decreased. Significant differences in the maximal extension and flexion instants in the forelimb joints were not detected (except in the elbow joint). The same was found in the angular range of motion (ARM) of the scapula inclination and the shoulder and forelimb fetlock joints. Differences in retraction-protraction angles in both the fore- and hindlimbs were very slight, and ARM values for these parameters were similar in all age groups. It can be concluded that Andalusian horses modified their locomotor pattern at the trot between age 12 and 36 months, particularly up to 24 months, by increasing stride length as well as shoulder, elbow and carpus flexion, while hip and stifle flexion decreased and hindlimb joints were more extended during the stance phase. One of the most striking features was that maximal retraction and protraction angles did not change in foals age 12-36 months in either fore- or hindlimbs. These results could be useful for the prediction of some kinematic parameters of mature horses from data obtained at younger ages.

Influence of training on the biokinematics in trotting Andalusian horses.

The aim of this study was to determine the influence of a 10-month training programme on the linear, temporal and angular characteristics of the fore and hind limbs at the trot in the Andalusian horse, using standard computer-aided videography. Sixteen male Andalusian horses were observed before and after training. Six strides were randomly selected for analysis in each horse and linear, temporal and angular parameters were calculated for fore and hind limbs. The training programme used here produced significant changes in kinematic parameters, such as shortening of stride length, and increase in swing duration and a decrease in hind limb stance percentage. No significant differences were recorded in the angular values for the forelimb joints. In trained horses, the more proximal joints of the hind limb, especially the hip and stifle, had a greater flexion while the fetlock showed a smaller extension angle. At the beginning of the swing phase, hip and stifle joints presented angles that were significantly more flexed. When the hind limbs came into contact with the ground, all the joints presented greater flexion after training.

Effects of a 3 month endurance training programme on skeletal muscle histochemistry in Andalusian, Arabian and Anglo-Arabian horses.

Twenty adult (5 to 14 years old) sedentary stallions of several breeds (8 Andalusians, 7 Arabians and 5 Anglo-Arabians) were endurance-trained for 3 months. Duplicate biopsies from 2 different depths (20 mm, superficial sampling site; 60 mm, deep sampling site) of the gluteus medius muscle were collected before and after training and after 3 months of detraining. Few significant changes in muscle fibre type composition were recorded in response to training. The percentage of type I fibres in the deep sampling site of the muscle in Andalusian horses and of type IIB oxidative fibres in the superficial region in Anglo-Arabians had increased significantly (P < 0.05) after training. The mean type I and IIA cross-sectional area was increased significantly (range P < 0.05 to P < 0.01) after 3 months' training in the deep site of the muscle in Arabian and Andalusian horses, but not in Anglo-Arabians. The changes seen in fibre sizes disappeared after the detraining period. The mean number of capillaries adjacent to type I fibres in the superficial sampling site of the muscle had increased significantly (P < 0.05) in response to training in Andalusian and Arabian horses. However, a significant decrease in the mean number of capillaries in contact with each fibre type relative to the mean area of that fibre type was observed associated with training in the deep region of the muscle for type I and IIA fibres in Arabians (P < 0.01) and for type I fibres in Andalusian horses (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

[Histochemical and morphometric characteristics of some extraocular muscles of the dog]. / Caracteristicas histoquimicas y morfometricas de algunos musculos extraoculares del perro.

This investigation was carried out on retractor bulbi, lateral and medial rectus muscles of six adult dogs. Tissues were collected from near the center of individual muscle bellies. These were stained for m-ATPase at varying pHs during preincubation, NADH-TR, Alpha-GPDH, Modified Mason trichrome and Hematoxyline and Eosin. Muscle fibers were classified as type I and type II, based on their reaction for m-ATPase. The retractor bulbi muscle was composed entirely of type II, oxidative, muscle fibers, with no glycolytic fibers. The rectus muscles presented a stratified composition, with superficial muscle fiber bundles containing a mixture of type II fibers oxidative and glycolytic, and central bundles of type I, mixed with type II. It was observed that there was less interstitial tissue in the center of the muscle bellies. Large diameter nerve fibers were also observed in the central layers.

Enzyme-histochemical profiles of fiber types in mature canine appendicular muscles.

The histochemical characteristics of skeletal muscle were assessed using a range of samples from 7 appendicular muscles taken from adult mixed-breed dogs (1.5 to 3 years of age). Two slow-twitch fiber subtypes (IA and IB) and three II subtypes (IIA, IIB and IIC) were identified according to myofibrillar myosin adenosine triphosphatase reaction after acid and alkaline preincubation. Type IIB fibers were not found in all muscles, and were only biologically significant in m. semitendinosus. The metabolic potential of these fibers is fairly similar to that of IIA fibers, but significantly different to that of IIB fibers in other mammals, suggesting that they may be designed to play a different functional role during locomotion. All canine muscle fibers have moderate to high oxidative capacity, which may be related to the extraordinary athletic capability of the species.

[Sexual models in adolescents and adults]. / Modelos sexuales en jóvenes y adultos.

Findings of a research that has been carried over among 13- to 19-year-old young people, their parents, and their teachers with regard to sex models of all involved are presented. Subjects were from the city of Buenos Aires, Argentina. Social representations of the three subject samples involved about sex behavior, certain values linked to sexuality, and certain gender patterns are discussed.