Stallion spermatozoa surviving freezing and thawing experience membrane depolarization and increased intracellular Na.

In order to gain insight of the modifications that freezing and thawing cause to the surviving population of spermatozoa, changes in the potential of the plasma membrane (Em) and intracellular Na+ content of stallion spermatozoa were investigated using flow cytometry. Moreover, caspase 3 activity was also investigated and the functionality of the Na+ -K+ ATPase pump was investigated before and after freezing and thawing. Cryopreservation caused a significant (p < 0.001) increase in the subpopulation of spermatozoa with depolarized sperm membranes, concomitantly with an increase (p < 0.05) in intracellular Na+ . These changes occurred in relation to activation of caspase 3 (p < 0.001). Cryopreservation reduced the activity of the Na-K+ pump and inhibition of the Na+ -K+ ATPase pump with ouabain-induced caspase 3 activation. It is concluded that inactivation of Na+ -K+ ATPase occurs during cryopreservation, an inhibition that could play a role explaining the accelerated senescence of the surviving population of spermatozoa.

Histomorphometric and immunohistochemical study of the goat abomasum during prenatal development.

This study sought to chart the morphological changes taking place in the goat abomasum during prenatal development, using histomorphometric and immunohistochemical techniques. A total of 140 goat embryos and fetuses, from the first stages of prenatal life until birth. Differentiation of the abomasum as a separate compartment of the primitive gastric tube was observed at 35 days of prenatal life (CRL 3 cm, 23% gestation). Primitive abomasal folds were first observed at 38 days (CRL 4.3 cm, 25% gestation). The muscularis mucosae was visible by 64 days (CRL 13.5 cm, 43% gestation). Transformation of pseudostratified epithelium to simple cylindrical epithelium was also observed at this stage. Differentiation of gastric pits and glands first became apparent at 75 days (CRL 17.5 cm, 50% gestation) and 84 days (CRL 20 cm, 55% gestation), respectively. Neuroendocrine cells were detected by synaptophysin (SYP) at 64 days (CRL 13.5 cm, 43% gestation), while glial cell markers (glial fibrillary acidic protein - GFAP, and vimentin-VIM) were observed at 64 days (CRL 13.5 cm, 43% gestation) and 38 days (CRL 4.3 cm, 25% gestation), respectively. Neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) were detected at 75 days (CRL 17.5 cm, 50% gestation). Gastrin-immunoreactive cells first appeared in the abomasum at 76 days (CRL 18 cm, 50% gestation). In conclusion, prenatal development of the abomasum appears to take place somewhat earlier in goats than in sheep or cattle, but at a similar rate to that reported in wild ruminants such as deer.

Ontogenesis of the reticulum with special reference to neuroendocrine and glial cells: a comparative analysis of the Merino sheep and Iberian red deer.

The present study was designed to compare the differences in the ontogenesis of the reticulum in sheep (domestic ruminant) and deer (wild ruminant). A total of 50 embryos and foetuses Merino sheep and 50 Iberian deer were used, from the first pre-natal life until birth. The appearance of the reticulum from the primitive gastric tube was earlier in the sheep (22% gestation, 33 days) than in the deer (25% gestation, 66 days). In both cases, it displayed a primitive epithelium of a stratified, cylindrical, non-ciliary type. At around 48% gestation in the sheep (72 days) and 36% (97 days) in the deer, the reticulum was configured of four clearly differentiated layers: mucosa (with epithelial layer and lamina propria), submucosa, tunica muscularis and serosa. The stratification of the epithelial layer was accompanied by modifications in its structure with the appearance of the primitive reticular ribs. The primary ribs began to be formed first in the deer, at 117 days of pre-natal life (40% gestation) and later in the sheep (79 days, 53% gestation). The differentiation of the corneum papillae in the primary ribs coincided with the appearance of secondary reticular ribs. These structures began to be formed first in the deer, at 142 days of pre-natal life (51% gestation) and later in the sheep (83 days, 55% gestation). The presence of neuroendocrine cells (non-neuronal enolase-positive cells) in the reticular mucosa was not detected until 97 days (36% gestation) in deer and 81 days (54% gestation) in sheep. The presence of glial cells (GFAP-positive cells) occurred at around 142 days (51% gestation) in deer and at 112 days (75% gestation) in sheep. In conclusion, the presence of neuroendocrine and glial cells was detected in deer at earlier stages than sheep.

Ontogenesis of the omasum: a comparative analysis of the Merino sheep and Iberian red deer.

The aim of this study is to describe differences in the ontogenesis of the omasum in sheep (domestic ruminant) and deer (wild ruminant). A total of 50 embryos and fetuses of Merino sheep and 50 Iberian deer were used, from the first stages of prenatal life until birth. For the study, the animals were divided into five experimental groups according to the most relevant histological characteristics. The appearance of the omasum from the primitive gastric tube was earlier in sheep (22% gestation, 33 days) than in deer (25% gestation, 66 days). In both cases it displayed a primitive epithelium of a stratified, cylindrical, non-ciliary type. The appearance of four laminae of different sizes was always earlier in sheep than deer. At around 36% gestation in sheep (53 days) and 36% (97 days) in deer, the omasum consisted of 4 clearly-differentiated layers: mucosa (with epithelial layer and lamina propria), submucosa, tunica muscularis and serosa. The temporal order of appearance of the four order laminae and omasal papillae was always earlier in sheep than deer. The tegumentary mucosa of the omasum was without secretion capability in the first embryonic phases. From 67 days (26% gestation) the neutral mucopolysaccharides appeared in deer and at 46 days (30% gestation) in sheep. In both cases they continued to decrease until birth, this decrease being more pronounced in deer. Finally, the presence of neuroendocrine and glial cells was detected in deer at earlier stages than in sheep.

Melatonin increases the survival time of animals with untreated mammary tumours: neuroendocrine stabilization.

The aim of this study was to evaluate the therapeutic effect of melatonin, the main hormone of the pineal gland, on rats with advanced and untreated mammary tumours. Mammary tumours were chemically induced in Sprague-Dawley rats with the carcinogen 9,10-dimethyl-1,2-bezanthracene (DMBA). After the appearance of tumours the effect of melatonin (5 mg/ml per rat per day) was then evaluated on the survival time, tumour multiplicity, and tumour volume until the death of the animals. In addition, the variations in prolactin, noradrenaline and adrenaline concentrations, and in the percentage of NK cells were evaluated after one month of the treatment with melatonin. Daily administration of melatonin increased significantly the survival time of tumour-bearing animals (p<0.05 with respect to the control non-melatonin-receiving rats). The increased survival time did not correlate, however, with changes in either tumour multiplicity or tumour growth rate. Animals with mammary tumours exhibited an increase (p<0.05 with respect to healthy animals) in prolactin and catecholamine concentrations. The administration of melatonin stabilized the hormone levels, returning them to those in the basal-healthy animals. Rats with mammary tumours also presented lower percentages of NK cells, which were not increased by the administration of melatonin. The results strongly suggest that melatonin per se is beneficial during advanced breast cancer. It increases survival time, maybe by improving the homeostatic and neuroendocrine equilibrium which is imbalanced during advanced breast cancer.

[Anti-hypertensive effect of eprosartan in diabetic patients]. / Efecto antihipertensivo del eprosartan en pacientes diabéticos.

OBJECTIVE: Diabetes mellitus seems to induce an special difficulty to control the high blood pressure. This effect is more severe on the SBP. Previous reports suggest that a new angiotensin receptor blocker, eprosartan, might have a higher efficacy to reduce SBP. It has been evaluated the BP decrease obtained with eprosartan in a group of diabetics patients compared to non diabetic patients. MATERIAL AND METHODS: 81 patients were recruited of whom 65 have ended follow-up. 34 patients were diabetics (mean age 66.7+/-10.7 years, 15 men and 19 women) and 31 were non diabetics control patients (mean age 61.8+/-12,8 years, 13 men and 18 women). All patients were treated with (600 mg) once daily. The doses was ingested in the morning. They were made three follow up visits (1, 3 and 6 mo after the first visit). RESULTS: SBP was significantly decreased both in diabetics (baseline 170.9+/-12.0, final 139.1+/-13.0 mmHg, p < 0.001) and in non diabetics group (baseline 169.9+/-18.0, final 142.0+/-13.3 mmHg, p < 0.001). DBP was also reduced in both groups (diabetics: baseline 92.9+/-9.7, final 78.4+/-8.5 mmHg, p < 0.001; non diabetics: baseline 95.6+/-7.9, final 79.1+/-7.4 mmHg, p < 0.001). Differences between the groups were not significant in any visit. Final BP reduction reached was -31.7/-14.6 mmHg in diabetics vs -27,6/-16,5 mmHg in non diabetics patients (difference is not significant) Pulse pressure changes were not different between the two groups (diabetics, 17.8+/-14.5, vs non diabetics, 11.1+/-13.2 mmHg). Two diabetic patients need a second drug to achieve BP goal and no one in non diabetic group. No adverse effects were reported. CONCLUSIONS: Eprosartan seems to be an effective drug to reduce SBP, DBP and pulse pressure with the same effectiveness in diabetics and non diabetic patients.

Efecto antihipertensivo del eprosartan en pacientes diabéticos / Anti-hipertensive effect of eprosartan in diabetic patients

Objetivo: La presencia de diabetes mellitus parece conferir una dificultad especial en el control de la HTA incidiendo particularmente sobre el componente sistólico de la PA. Estudios previos sugieren que un nuevo antagonista de los receptores de angiotensina, eprosartan, podría tener una mayor eficacia en la reducción de la PAS. Se ha evaluado de forma comparativa la reducción de la PA obtenida con eprosartan en un grupo de pacientes diabéticos y sin diabetes mellitus. Material y métodos: Se reclutaron para el estudio 81 pacientes de los cuales 65 habian terminado el periodo de seguimiento. De ellos, 34 pacientes eran diabéticos (edad 66,7 ± 10,7, 15 hombres y 19 mujeres) y 31 no padecían diabetes (edad 61,8 ± 12,8, 13 varones y 18 mujeres). Todos los pacientes fueron tratados con eprosartan (600 mg) en dosis única matutina. Se realizaron visitas de revisión al mes, a los 3 meses y a los 6 meses de la primera consulta. Resultados: La PAS se redujo significativamente tanto en el grupo de diabéticos ( inicial 170,9 ± 12,0, final 139,1 ± 13,0 mmHg, p < 0,001) como en el grupo sin diabetes (inicial 169,9 ± 18,0, final 142,0 ± 13,3 mmHg, p < 0,001). Lo mismo ocurrió con la PAD tanto en diabéticos (inicial 92,9 ± 9,7, final 78,4 ± 8,5 mmHg, p < 0,001) como en pacientes sin diabetes (inicial 95,6 ± 7,9, final 79,1 ± 7,4 mmHg, p < 0,001). Las diferencias entre ambos grupos no fueron significativas ni en la visita inicial ni en ninguna de las visitas de revisión. La reducción final obtenida fue -31,7 / -14,6 mmHg en diabéticos y -27,6 / -16,5 mmHg en paciente sin diabetes (diferencia sin significación). La reducción final en la presión de pulso no fue diferente entre ambos grupos (diabéticos, 17,8 ± 14,5, frente a pacientes sin diabetes, 11,1 ± 13,2 mmHg). Dos pacientes diabéticos necesitaron añadir otro fármaco al tratamiento para conseguir el control de la PA y ninguno en el grupo de pacientes sin diabetes. No se han detectado efectos secundarios. Conclusiones: El eprosartan demostró ser un fármaco efectivo para reducir ambos componentes de la PA, sin perder eficacia en los pacientes que padecen diabetes mellitus (AU)

Day-night changes in plasma melatonin levels, synaptophysin expression and ultrastructural properties of pinealocytes in developing female sheep under natural long and short photoperiods.

The aim of the present study was to analyze the 24-h rhythm in plasma melatonin concentration and the day-night differences in synaptophysin expresion and ultrastructural characteristics of the pinealocytes in developing female sheep. Ewes of three different ages were examined: infantile (1-6 months old), pubertal and early fertile age (9-24 months old) and adult (36-60 months old). Experiments were conducted under natural non-stimulatory (long) and stimulatory (short) photoperiods. The obtained results were similar for both analyzed photoperiods. Plasma melatonin concentration, measured in samples obtained every 4 h, showed a similar pattern in the three age groups, with peak values at 02:00 h and troughs at 14:00 h. Mean value of plasma melatonin levels in 9-24 month-old sheep was significantly greater than that in younger or older sheep. The weight of pineal glands obtained at night (02:00 h) was significantly higher than in daylight (14:00 h). Pubertal and early fertile sheep had the largest pineal glands. The pineal volume, and the total number of pinealocytes per gland of 9-24 months-old sheep differed significantly from that of younger or older sheep. The pineal volume, and the mean volume of pinealocytes was significantly greater in animals killed at night. Number of pinealocytes did not vary between animals killed during daylight or at night. The mean volumen of pinealocytes did not show statistical differences between the age groups. In quantitative ultrastructural analysis of pinealocyte cells, the relative volume of mitochondria, rough endoplasmic reticulum and Golgi complexes was significantly greater in 9-24 month-old sheep and in animals killed at night. The relative volume of lipid droplets was highest in older sheep. Collectively, the data support the existence of developmental changes in pinealocyte morphology and quantity, partially in coincidence with a higher melatonin secretion rate.

Postnatal development of female sheep pineal gland under natural inhibitory photoperiods: an immunocytochemical and physiological (melatonin concentration) study.

The purpose of this study was to determine structural and immunocytochemical changes taking place during the day and at night in developing sheep pineal gland under natural non-stimulatory photoperiods (summer solstice). Additionally, the diurnal cycle of plasma melatonin levels was charted and differences between diurnal and nocturnal pineal melatonin concentrations were analyzed. 36 ewes of three different ages were examined: infants (1-6 months old), pubertal and early fertile age (9-24 months old) and adults (36-60 months old). Plasma and pineal gland melatonin levels were higher in pubertal sheep than in infants or adults. Pubertal sheep pineal glands were also heavier, contained a larger number of pinealocytes and interstitial cells and displayed more evident innervation and vascularisation than infants or adults. There was no difference in the number of pinealocytes and interstitial cells between animals killed during daylight or at night. Gland weight, pinealocyte nuclear profile areas and plasma melatonin concentrations were all significantly higher at night than during the day.

Lesions induced by 2,4-D and chlorpyrifos in tench (Tinca tinca L.): implication in toxicity studies.

This study was undertaken to demonstrate the toxicity of two pesticides, chlorpyrifos (O,O-diethyl 0-3,5,6-trichloro-2-pyridyl phosphorothioate) and 2,4-D (Dichlorophenoxyacetic acid) to tench (Tinca tinca Linnaeus). Pathological samples of damaged tench kidney showing lesions were taken for statistical analysis in order to quantify different parameters. Analysis revealed differences in the action and/or action time of the two pesticides. These differences were more acute in the case of 2,4-D thereby indicating a greater toxicity. These differences, expressed by mathematical formulae of numerical variables, would enable, a priori, the identification of the responsible pesticide and the time of acting in new natural cases of poisonings with these substances.

Acute 2,4-D poisoning in tench (Tinca tinca L.): lesions in the hematopoietic portion of the kidney.

An experimental model was designed to study the acute lesions caused by a continuous exposure to 2,4-dichlorophenoxyacetic acid (2,4-D) disolved in water (400 mg/L) in hematopoietic kidney tissue in tench (Tinca tinca L). Fifty fish were used in this study, 15 for calculating LC50 and 35 were euthanized 1, 2, 5, 8, and 12 days postpoisoning (five treated and two controls each time). Tissue samples, fixed in 5% glutaraldehyde in 0.1 M phosphate buffer (pH 7. 2) for histopathological examination, revealed marked alteration of hematopoietic tissue, characterized by progressive swelling and cell necrosis, activation of the phagocyte system, and subsequent formation of myelin figures. Variations recorded in hematocrit and hemoglobin levels in blood samples indicated changes in membrane permeability, complementing the findings on hematopoietic tissue. The lethal dose (LC50) at 96 h demonstrated the importance of the species and chemical form used as factors in calculating a product's toxicity.

Structure of the ovine pineal gland during prenatal development.

The structure of the pineal gland of 32 clinically healthy ovine embryos at different stages of development was studied. Embryos were arranged in four age groups, each containing eight embryos (four males and four females), defined in terms of the most relevant histological features: group 1 (27 to 69 days of prenatal development), group 2 (70 to 97 days), group 3 (98 to 116 days), and group 4 (117 to 150 days). At around 30 days of prenatal life, according to topographic criteria, the pineal outline begins to differentiate into a dorsal evagination of the diencephalic medium line, close to the anterior and posterior commissures. The growth of the pineal is biphasic. The ontogenic-proliferative phase begins at 30 days and includes the invasion of ependymal cells and the proliferation of the pineal parenchyma cells. The hypertrophic-differentiation phase includes the volume increment of the pinealoblasts and their differentiation into pinealocytes; this occurs at around 118 days. At around 98 days, the gland acquires its definitive compact appearance due to 1) glandular growth in constant volume and 2) the obliteration of pineal recess. The glandular structure displays a parenchyma made up of pinealoblasts, interstitial cells, and cells containing pigment. The pineal stroma is structured in pseudolobes formed by reticular and collagen fiber septae, which constitute together the interstitial cell prolongation net, which is the support structure of the whole glandular cytology. Capillaries are detected all over the glandular surface, being more abundant in the medullary zone. At around 98 days of prenatal development, VIP (Vasoactive Intestinal Peptide) positive fibers, distributed around blood vessels and among pinealoblasts were detected.

[Volvulus of the transverse colon: a rare cause of intestinal obstruction]. / Vólvulo de colon transverso: una causa poco frecuente de obstrucción intestinal.

Volvulus of the transverse colon is rare, given its short and fixed mesentery and the normal fixation of the hepatic and splenic flexures of the colon. The case reported herein brings the total of reported cases to 72. Various predisposing factors have been identified, most notably congenital abnormalities, physiologic disturbances and mechanical obstruction; in our case these three factors were present. The possible role of colonoscopy in diagnosis and/or therapy is unclear. In our patient, colonoscopy proved to be of no use for diagnosis or treatment.

Adenocarcinoma of the ethmoid olfactory mucosa: a histopathological and ultrastructural study with evidence of virus-like particles.

A histopathological, morphometric and ultrastructural study was made of enzootic nasal neoplasia in a group of 25 Verata goats. A nasal adenocarcinoma was diagnosed. The neoplasm contained two clearly defined zones, one cystic and the other compact. The tumour stroma was composed of abundant loose connective tissue, in which mononuclear infiltrate was clearly identifiable. The observed viral particles were morphologically similar to Visna-Maedi. These particles had an eccentrically located electrodense core. The diameter of the virus was about 90 nm and it showed envelope numerous spikes on the surface. The virus is assumed to be the causative primary agent of the tumour.

Morphometric, structural, and ultrastructural studies of tench (Tinca tinca L.) hepatocytes after copper sulfate administration.

A structural, ultrastructural, and morphometric study was made of the liver parenchyma of 12 adult tench (Tinca tinca, L.) subjected to acute experimental copper sulfate poisoning. The lesions observed were characterized by the accumulation in the cytoplasm of large amounts of hemoglobinemic pigment produced by intense hemolysis, initially in Kupffer cells and by the last stage of the experiment in hepatocytes. This process became increasingly severe, and culminated in the massive necrosis of large areas of liver parenchyma, which led to the death of tench 12 days after the start of the experiment.