VENOUS AND ARTERIAL ACID-BASE ANALYSIS OF MAGELLANIC PENGUINS (SPHENISCUS MAGELLANICUS), AWAKE AND ANESTHETIZED BY ISOFLURANE.

This study aimed to compare the venous acid-base status of healthy awake versus anesthetized Magellanic penguins (Spheniscus magellanicus). Ten nonanesthetized penguins were manually restrained, and a venous blood sample was collected. Six of these penguins were anesthetized by 2% isoflurane and, after an anesthetic stabilization period, both venous and arterial blood samples were simultaneously withdrawn. Using an i-STAT analyzer, partial pressure of carbon dioxide (PCO2), partial pressure of oxygen (PO2), pH, standard bicarbonate concentration (HCO3-), total carbon dioxide (ctCO2), oxygen saturation (SO2), base excess (BE), Na+, and K+ levels were measured in venous blood samples of awake (Gawake) penguins and in venous (Gven) and arterial blood (Gart) samples of anesthetized penguins. There were no significant differences between groups in pH, BE, or Na+. Venous carbon dioxide pressure, HCO3-, and venous ctCO2 were higher in Gven than Gawake penguins, whereas PCO2 was higher in Gven than Gart penguins. PO2 and SO2 were higher in the Gart group than in the other groups. Both venous and arterial blood samples may be used to evaluate the acid-base profile of Magellanic penguins.

Arterial tissue and plasma concentration of enzymatic-driven oxysterols are associated with severe peripheral atherosclerotic disease and systemic inflammatory activity.

INTRODUCTION: Cholesterol undergoes oxidation via both enzymatic stress- and free radical-mediated mechanisms, generating a wide range of oxysterols. In contrast to oxidative stress-driven metabolites, enzymatic stress-derived oxysterols are scarcely studied in their association with atherosclerotic disease in humans. METHODS: 24S-hydroxycholesterol (24S-HC), 25-hydroxycholesterol (25-HC), and 27-hydroxycholesterol (27-HC) were assessed in plasma and arteries with atherosclerotic plaques from 10 patients (54-84 years) with severe peripheral artery disease (PAD) as well as arteries free of atherosclerotic plaques from 13 individuals (45-78 years, controls). RESULTS: Plasma 25-HC was higher in PAD individuals than in controls (6.3[2] vs. 3.9[1.9] ng/mgCol; p = 0.004). 24S-HC and 27-HC levels were, respectively, five- and 20-fold higher in the arterial tissue of PAD individuals than in those of the controls (p = 0.016 and p = 0.001). Plasma C-reactive protein correlated with plasma 24-HC (r = 0.51; p = 0.010), 25-HC (r = 0.75; p < 0.001), 27-HC (r = 0.48; p = 0.015), and with tissue 24S-HC (r = 0.4; p = 0.041) and 27-HC (r = 0.46; p = 0.023). CONCLUSION: Arterial intima accumulation of 27-HC and 24S-HC is associated with advanced atherosclerotic disease and systemic inflammatory activity in individuals with severe PAD.

Asociación patomorfológica y morfométrica de la lesión aterosclerótica en siete diferentes sectores arteriales / Pathomorphological and morphometric association of the atherosclerotic lesion in seven different arterial sectors

Se investigaron 460 necropsias de pacientes procedentes del Hospital Docente Dr Carlos J Finlay, realizadas entre 1999 y 2003. Se analizaron 18 arterias procedentes de los siete sectores vasculares siguientes: el polígono de Willis, considerado como una sola arteria, las tres coronarias epicárdicas (derecha, descendente anterior y circunfleja izquierda), la aorta (torácica y abdominal), las renales, las ilíacas y las femorales. Para el estudio patomorfológico y morfométrico se utilizó el sistema aterométrico. Las arterias se disecaron, se fijaron, se colorearon y se les realizaron los análisis cualitativo y cuantitativo para el estudio estadístico mediante la correlación canónica. Entre los resultados más relevantes se observaron muy fuertes correlaciones entre la estría adiposa, la placa fibrosa y la placa grave en los análisis entre todas las arterias investigadas, con algunas excepciones. El conjunto de estos resultados sugiere que la aterosclerosis es un proceso de distribución sistémica.

Four hundred and sixty necropsies of patients from Carlos J Finlay Hospital performed between 1999 and 2003 were investigated. Eighteen arteries from the following seven vascular arteries were analyzed: Willis circle, considered as only one artery, the three epicardial coronaries (right, anterior descending and left circumflex), the aorta (thoracic and abdominal); the two renal, the iliac and the phemoral. An atherometric system was used for the pathomorphological and morphometric study. The arteries were dissected, fixed and coloured. A qualitative and quantitative analysis was made for the statistical study by canonical correlation. Among the most important results there were observed very strong correlations between the adipose stria, the fibrous plaque and the severe plaque in the analyses of all among all the investigated arteries, with a few exceptions. All these results strongly suggest that atherosclerosis is a process of systemic distribution.

Efecto de la vitamina C, sobre la actividad de glutation peroxidasa y la formación de ateromas, en conejos expuestos a dieta hiperlipidémica / Effects vitamin C, on glutathione peroxidase activity and atheroma formation, in rabbits exposed to a hyperlipidaemic diet

El estrés oxidativo juega un papel muy importante en la aterosclerosis; de hecho existe evidencias que indican que los antioxidantes son moléculas capaces de retardar y/o revertir el proceso aterosclerótico. El objetivo del presente estudio fue comparar el efecto de la vitamina C (Vit C), sobre la actividad de la Glutation peroxidasa (GPx) y la formación de ateromas en conejos. Se estudiaron 36 conejos divididos en 3 grupos: Grupo 1 (Control): conejarina, Grupo 2: huevo y conejarina, Grupo 3: huevo, conejarina y Vit C (100mg/diarios). el período experimental duró 12 semanas. Se determinó perfil lipídico por métodos enzimáticos y la actividad de GPx por cinética en 0 y 12va semana. Los conejos fueron sacrificados y se les realizó estudio histológico de su aorta. Los resultados revelaron un incremento en la actividad de la GPx en los grupos 2 y 3 con respecto al control en la 12va semana de experimentación (p<0,05). Hubo inhibición de lesiones ateroscleróticas en los conejos del grupo 3. En conclusión en condiciones de hiperlipidemia con o sin suplementación de Vit C, existe incremento en la actividad de GPx. Por otra parte, la Vit C disminuye y evita la progresión de ateromas.

Oxidative stress plays an important role in artherosclerosis; so antioxidants are molecules have been used to slow down or inihibit atherosclerosis. The objetive of the presents study was to compare the effect of Vitamin C (Vit C), on serum Glutathione peroxidase activity (GPx) and on the formation of aortic lesions in rabbits. 36 rabbits were studied: Group 1: "conejarina" (commercial rrabit food); Group 2: egg and conejarina, Group 3: egg, conejarina and Vit C (100mg/day). The experimental lasted 12 weeks. Lipid profile was done by enzymatic methods and GPx by kinetic method in weeks 0 and 12. Histological study of rabbit's aorta was done. GPx activity in groups 2 and 3, increased compared with controls, from weeks 12 of experimentation (o<0,05). There was inihition of aortic lesions in groups 3. In conclusion, under hyperlipidemic conditions, with or without Vit C supplementation, activity of GPx there is increase. Vit C reduces and prevents the progression of atheromas.

Vascular organization of the hystricomorph placenta: a comparative study in the agouti, capybara, guinea pig, paca and rock cavy.

The placental vasculature of five hystricomorph rodents was examined by latex injection of the blood vessels, immunohistochemistry and scanning electron microscopy of vessel casts. The pattern of branching of the vessels is described at the level of fine structure. The placenta is divided into lobes separated by interlobular trophoblast. Fetal arteries course through the interlobular areas and give rise to capillaries from which blood drains into veins at the centre of the lobes. Maternal blood reaches the placenta through spiral arteries that pass around the perimeter of the subplacenta. They supply large maternal blood sinuses, lined by trophoblast, which run through the interlobular areas and into the centre of the lobes. Here they supply fine channels that run parallel to the fetal capillaries, so that maternal blood flows from the centre of the lobe to the periphery. This arrangement provides the morphological basis for countercurrent exchange. The maternal channels of the labyrinth drain into spaces formed by the latticework of the interlobular trophoblast and thence through venous lacunae to a basal venous lacunar ring. The subplacenta is supplied by a single fetal artery. The vessels within the subplacenta pursue a tortuous course with dilatations and constrictions as in an endocrine gland.

Mechanisms involved in the water intake-related pressor response in the rat.

OBJECTIVE: In this study we aimed to characterize and clarify the mechanisms involved in the acute blood pressure increase observed concomitantly with water intake in moderately dehydrated rats. DESIGN: Short-term water deprivation was employed as a model to induce controlled water intake to study concomitant cardiovascular responses in the rat. METHODS: Male Wistar rats were deprived of water for 18-24 h before the experiments and were allowed to drink for 20 s periods during the experimental session. During these periods water intake was accompanied by steady arterial pressure increases. This pressor response was unaffected by topical anesthesia of the oral cavity. Direct administration of water into the stomach did not cause pressor responses. The pressor response was not affected by bilateral adrenal demedullation or by pretreatment with diazepam, homatropine methyl bromide, d(CH2)5 Tyr(Me)AVP, losartan or RX821002. The pressor response was significantly reduced by ganglionic blockade with mecamylamine or pretreatment with the alpha1-adrenoceptor antagonist, prazosin. CONCLUSIONS: Our results show that: (1) short-term dehydration can be used as a model to study cardiovascular responses associated with water intake in rats; and (2) the sympathetic nervous system and vascular smooth muscle alpha1-adrenoceptors are involved in the pressor response to water intake by dehydrated rats.

Pathological mineralizations: calcifications and Si-bearing particles in soft tissues and their eventual relationship to different prostheses.

Polarizing microscopy (PM), scanning electron microscopy (SEM), x-ray dispersive analysis (EDAX), x-ray diffraction (XRD), and infrared spectrometry (IR) were used to study the following pathological mineralizations: calcifications and silicon(Si)-bearing mineralizations in cerebral tissue from an epileptic child; traces of Si-bearing particles in periprosthesic mammarian tissue, and calcifications in capsular mammarian tissue from a patient with a silicone gel mammarian implant, and 2 calcium-bearing compounds, a typical apatitic calcification, and a nonphosphorous-bearing calcification in arterial tissues. In this tissue we also found Si-bearing particles due to an artifact from glassware.

Distribuição comparativa dos glicosaminoglicanos em artérias e veias de diferentes mamíferos / Comparative distribution of glycosaminoglycans in arteries and veins of different mammals

Foi realizada análise comparativa sobre a distribuição dos glicosaminoglicanos de artérias e veias em ratos, cachorros e humanos. Os nossos resultados demonstraram que dermatam sulfato foi o principal glicosaminoglicano encontrado tanto para as artérias quanto para as veias estudadas. Entretanto, a proporção de dermatam sulfato foi maior nas veias do que nas artérias nas três espécies analisadas. Este aumento pode estar associado às diferenças estruturais e funcionais encontradas na parede destes dois tipos de vasos sangüíneos (nas veias a pressão sangüínea é significativamente mais baixa). Além disso, a quantidade total dos glicosaminoglicanos foi maior nas artérias do que nas veias, sendo as maiores concentrações encontradas nas aortas independentemente da espécie animal estudada. Estes achados abrem perspectiva para o melhor conhecimento das alterações das macromoléculas que possam estar relacionadas ao processo degenerativo vascular, especialmente nas transformações estruturais que as veias safenas sofrem, quando empregadas como enxertos na revascularização do miocárdio

Intracellular calcium stores and oscillatory contractions in arteries from genetically hypertensive rats.

Strips of tail artery from stroke-prone spontaneously hypertensive rats (SHRSP), but not from normotensive Wistar Kyoto (WKY) rats, exhibit oscillatory activity after stimulation with norepinephrine. In addition, oscillatory activity is observed in response to tetraethylammonium (TEA) in vessels from both SHRSP and WKY rats. Mechanistically, the oscillatory contractions are associated with calcium (Ca2+)-driven action potentials. We have tested the hypothesis that intracellular Ca2+ stores participate in the generation of norepinephrine-induced oscillatory contractions in tail arteries from SHRSP. Additionally, the role of intracellular Ca2+ stores on TEA-induced contractions were evaluated. Contractile force in strips of tail artery from SHRSP and WKY rats was measured, using standard muscle bath procedures, and the effect of interventions that affect the storage of intracellular Ca2+ on the oscillatory contractions was evaluated. Depletion of intracellular Ca2+ stores, with ryanodine, or inhibition of Ca2+ uptake into the sarcoplasmic reticulum (SR), with thapsigargin and cyclopiazonic acid (CPA), did not inhibit oscillatory contractions induced by norepinephrine in SHRSP vessels. However, these agents inhibited the amplitude of TEA-induced contractions in WKY strips. Bay K 8644 and A23187 inhibited TEA-induced oscillatory contractions in WKY vessels. In SHRSP tail artery Bay K 8644 inhibited both norepinephrine and TEA-induced contractions, while A23187 did not have any effect. The phospholipase C inhibitor, NCDC (3X 10(-5) M), blocked oscillatory activity induced by norepinephrine in SHRSP tail artery and TEA-induced oscillations both in SHRSP and WKY vessels. These observations suggest that Ca2+ release and Ca2+ uptake into intracellular Ca2+ stores are not involved in the contraction-relaxation cycles that characterize norepinephrine-induced oscillatory activity in SHRSP tail artery. Similarly, SR Ca2+ stores may modulate but are not essential for TEA-induced oscillatory contractions.

Compositional and structural alterations of arterial glycosaminoglycans associated with the complications brought about by thalassemia major. A case report.

A biochemical analysis of glycosaminoglycans was performed in arteries of a fifteen-year old white male who died of beta thalassemia major. The patient presented the severe clinical complications resulting from hemochromatosis, which was evidenced at autopsy and by histologic examination. The arteries under study comprised the thoracic and abdominal aortas and the iliac and pulmonary arteries, which were compared with the same arteries from normal individuals. Data on total glycosaminoglycan and total collagen, including the determination of the relative contents of the different glycosaminoglycans, suggest an as yet undescribed fibrotic process in the thalassemic arteries. Also altered were the proportions of the disaccharides making up chondroitin sulfate and heparin sulfate. A reduction in the molecular weight of arterial heparin sulfate, presumably with free radical involvement, was also detected. All these changes in the extracellular matrix may be ascribed to the presence of large amounts of iron in the tissue, and as such they should be expected in other disorders with chronic iron overload.

Arterial connective tissue alterations in thalassemia major: a biochemical study of a case with severe iron overload.

A biochemical analysis of glycosaminoglycans and collagen was performed in arteries of a 15-year old teenager who died of beta thalassemia major. The patient presented the severe clinical complications resulting from hemochromatosis, which was evidenced at autopsy and by histological examination. The arteries under study comprised the thoracic and abdominal aortas and the iliac and pulmonary arteries, which were compared with the same arteries from normal individuals. Data on total glycosaminoglycan and total collagen, including the determination of the relative contents of the different glycosaminoglycans, suggest an as yet undescribed fibrotic process in the thalassemic arteries. Also altered were the proportions of the disaccharides making up chondroitin sulfate and heparan sulfate. A reduction in the molecular weight of arterial heparan sulfate, presumably with free radical involvement, was also detected. These changes in the extracellular matrix may be ascribed to the presence of large amounts of iron in the tissue, and as such they should be expected in other disorders with chronic iron overload.

Glycosaminoglycan fractions from human arteries presenting diverse susceptibilities to atherosclerosis have different binding affinities to plasma LDL.

The topographic distribution of atherosclerotic lesions is influenced by biochemical factors intrinsic to the arterial wall. In the present work we have investigated whether the composition/chemical structure of glycosaminoglycans constitutes one of these factors. Normal human arteries were obtained at necropsy, and in order of decreasing susceptibility to atherosclerosis, consisted of the abdominal and thoracic aortas and the iliac and pulmonary arteries. The results showed similar concentrations of total glycosaminoglycan and collagen. Of the glycosaminoglycans known to interact with low-density lipoprotein (LDL), dermatan sulfate was present in all arteries in comparable concentrations, but the aortas had a 30% higher content of chondroitin 4/6-sulfate, which in turn was slightly enriched in 6-sulfated disaccharide units. LDL-affinity chromatography with dermatan sulfate+chondroitin 4/6-sulfate fractions demonstrated that increasing affinity to LDL matched an increasing susceptibility to atherosclerosis. Analysis of glycosaminoglycans in the eluates indicated a positive correlation between affinity to LDL and increasing molecular weight and the existence of a fraction of glycosaminoglycans of high affinity to LDL in the aortas only. These results suggest that arterial glycosaminoglycans participate in the multifactorial mechanisms that modulate the differential localization of atherosclerotic lesions.