Papers by Antonio Lorenzo
Comparative Biochemistry and Physiology Part A: Physiology, 1989
Ahatract-1 . The influx and transepithelial movements of L-methionine and its effects on the elec... more Ahatract-1 . The influx and transepithelial movements of L-methionine and its effects on the electrophysiology and Na-Cl-transport in upper and lower intestine of the cultured fish, Sparus aurafa, were measured.
Ahatract-1 . The influx and transepithelial movements of L-methionine and its effects on the elec... more Ahatract-1 . The influx and transepithelial movements of L-methionine and its effects on the electrophysiology and Na-Cl-transport in upper and lower intestine of the cultured fish, Sparus aurafa, were measured.
Journal of Neuropathology and Experimental Neurology, 1989
Approximately 20% of preterm rabbit pups develop spontaneous germinal matrix hemorrhages (GMH). T... more Approximately 20% of preterm rabbit pups develop spontaneous germinal matrix hemorrhages (GMH). To understand better the pathogenesis of GMH we studied the ultrastructure of germinal matrix (GM) blood vessels in rabbits delivered at gestational day 28. Regardless of luminal size, the walls of most GM vessels had the structural characteristics associated with a blood-brain barrier (BBB) and consisted of endothelial cells and pericytes, surrounded by GM cell processes. Endothelial cells ranged from voluminous to attenuated, with some cells containing intracytoplasmic, membrane-bound vacuoles, and luminal as well as abluminal cytoplasmic projections. Some short interendothelial junctions had no puncta adherentia, whereas long ones often possessed intermittent pores. In two animals with GMH, intact endothelial cells were separated by narrow and wide gaps filled with luminal contents that occasionally extended beyond the interendothelial opening. The basal lamina (BL) was ill-defined, thin, often discontinuous and of low electron density. Smooth muscle cells and collagen were not present, which precluded any classification into arteries, capillaries and veins. Germinal matrix cell processes lacking both micro- and intermediate filaments were haphazardly disposed around the blood vessel walls in place of astrocytic endplates. Recent reports indicate that an astrocytic environment may be necessary for the development of the interendothelial tight junctions and BL. The presence of "glial foot" processes that lack ultrastructural characteristics of mature astrocytes suggests that interendothelial junctions and basal laminae in the vessels of the ganglionic eminence may not have the necessary structural and functional potential to withstand the transmural pressures or the pathophysiological influence of hypertension, hyperosmolarity, sepsis, and other factors known to open the BBB and to contribute to GMH.
Journal of Neurosurgery, 1974
... Howard M. Eisenberg, MD, J. Gordon McComb, MD, and Antonio V. Lorenzo, Ph.D. Departments of N... more ... Howard M. Eisenberg, MD, J. Gordon McComb, MD, and Antonio V. Lorenzo, Ph.D. Departments of Neurosurgery and Neurology, Children's Hospital Medical ... Abstract | Full Text | PDF (207 KB). Michael J. Albeck, MD, Svend E. Børgesen, MD, Ph.D., Flemming Gjerris, MD, Ph.D ...
Brain, 1970
INTRODUCTION IT is generally considered that under normal conditions almost all the cerebro-spina... more INTRODUCTION IT is generally considered that under normal conditions almost all the cerebro-spinal fluid (CSF) is formed by the ventricular choroid plexuses. The fluid passes out of the ventricles by way of the foramen of Luschka and Magendie into the subarach-noid ...
Journal of Neurosurgery, 1989
To better understand the role of myelin-associated water in the differentiation of white and gray... more To better understand the role of myelin-associated water in the differentiation of white and gray matter in magnetic resonance (MR) imaging, changes in MR relaxation processes were studied in rabbits during myelination and after induction of cytotoxic edema with triethyltin (TET). Normal rabbits were killed at various age intervals ranging from premature (28 days' gestation) to adult, and changes in MR relaxation times (T1 and T2) and in water and electrolyte content were determined for various areas of brain and muscle. Similar measurements were made in rabbits of comparable age exposed to TET. Light and electron microscopy and MR imaging were used to follow myelin development and morphological changes induced by TET. During the first 30 postnatal days, both T1 and T2 declined by 50% in normal rabbits, a fall that paralleled the loss in brain water and sodium that occurred during the same period. Exposure to TET prolonged T1 and T2 in white but not gray matter, reflecting the accumulation of sodium and water (edema fluid) in white matter areas. Multiexponential analysis revealed a second, longer component in T2 magnetization decay of TET-exposed white matter, presumably attributable to accumulation of non-ordered water within intramyelinic vacuoles, a supposition consistent with electron microscopic and MR imaging findings. In contrast to reports by others, changes in T1 (but not T2) closely correlated with alterations in brain water (r = 0.93, df = 39). The absence of tissue disruption in the animals in the present study may account for these differences, but further studies will be required both to resolve this question and to fully understand MR images of white matter edema in mature and immature brain.
Helgoland Marine Research, 2013
Captive Octopus vulgaris adults were fed three mono-diets based on pilchard, crab and squid and a... more Captive Octopus vulgaris adults were fed three mono-diets based on pilchard, crab and squid and allowed to grow until reproduction under controlled temperature. Spawns from each dietary treatment were isolated, and the embryonic development, egg length, width and wet weight, in addition to neonate dry weight, dorsal mantle length and ventral mantle length were monitored. Pilchard-diet spawns developed faster in terms of thermal time. Initial egg wet weight was higher for squid and crab diets. Irrespective of the parental diet, eggs passed through a swelling process so that egg width and wet weight increased in a nonlinear way, whereas egg length was left nearly unaffected. Egg length and initial wet weight showed a high correlation with neonate dry weight. Egg length, even at advanced incubation, can be used as a good proxy for neonate dry weight, this fact having potential implications for the ecological and aquaculture research on O. vulgaris.
Fish Physiology and Biochemistry, 2011
A feeding experiment was carried out to determine the effect of a diet lacking n-3 and n-6 highly... more A feeding experiment was carried out to determine the effect of a diet lacking n-3 and n-6 highly unsaturated fatty acids (HUFA) on lipid and fatty acid content in intestine and gills of male gilthead seabream (Sparus aurata L.) broodstock at different stages of the reproductive cycle: November (pre-spermatogenesis), March (spermatogenesis), and June (post-spermatogenesis). For this purpose, gilthead seabream broodstock were fed either a control diet (C) or an n-3 and n-6 HUFA-deficient diet (D). The results showed no changes in fatty acid content of polar lipids of intestine and gills from fish fed diet C at different stages of the reproductive cycle. However, significant changes were observed in the fatty acid content of neutral lipids in intestine but not in gills in this group. Thus, between November and March, saturates and n-3 HUFA decreased while monoenes increased. In June, the contents of these fatty acids had returned to their initial values (November). Moreover, in fish fed diet D, the fatty acid content of neutral lipid changed in both intestine and gills. In intestine NL, a decrease in saturates and n-3 HUFA and an increment in monoenes were observed from November to June. In gills, a decrease was also observed in n-3 HUFA from NL along the cycle. Nevertheless, n-6 HUFA content remained unchanged. These results show both tissue specificity in seasonal mobilization of fatty acids linked to reproductive processes and the influence of dietary fatty acids on body composition.
European Journal of Lipid Science and Technology, 2014
To establish the changes which occur during embryogenesis and early larvae development, eggs, yol... more To establish the changes which occur during embryogenesis and early larvae development, eggs, yolk-sac larvae (one day old larvae) and absorbed yolk-sac larvae (three day old larvae) of white sea bream were examined for lipid class and fatty acid composition. The development was characterized by a decrease in all lipid classes with the exception of phosphatidylserine (PS) and fatty free acids (FFA) which increased, and sphingomyelin (SM) which remained unchanged. The changes observed in lipid class content and the decrease in fatty acids in total lipid (TL) reflect the utilization and mobilization of lipids during both embryogenesis and early larvae development. Fluctuations in the relative composition of fatty acids in phosphatidylcholine (PC) during development suggest a selective bulk uptake and catabolism of fatty acids in this lipid class. Unlike PC, catabolism of triacylglycerol (TG) fatty acid appears to be non-selective. During development, the decrease in levels of polyunsaturated fatty acids (PUFA) eicosapentaenoic (20:5n-3, EPA) and docosahexaenoic (22:6n-3, DHA) in total lipid denotes their utilization as energy substrate by Diplodus sargus larvae.
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 1998
Gilthead seabream intestine contains both a Mg2+-dependent Na+–K+-ATPase which is completely inhi... more Gilthead seabream intestine contains both a Mg2+-dependent Na+–K+-ATPase which is completely inhibited by 1×10−3 M ouabain, and also a residue-ATPase activity that is entirely ouabain-insensitive. The maximal activity of intestinal Na+–K+-ATPase (35.15 μmol inorganic phosphate (Pi) mg protein−1 h−1) was observed in the microsomal fraction at 35°C, pH 7.5, 2–5 mM MgCl2, 5 mM ATP, 10 mM K+ and 200
Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology, 2004
Total lipids (TL), lipid classes, and their associated fatty acids from muscle and liver of capti... more Total lipids (TL), lipid classes, and their associated fatty acids from muscle and liver of captive and wild mature female broodstocks were investigated in order to estimate the fatty acid requirements of white seabream (Diplodus sargus). The results showed that the percentage of triacylglycerol was higher in liver and muscle of captive fish than in wild fish. The distribution of phospholipid classes in liver and muscle of both fish groups was similar, phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol being the predominant lipid classes. The general pattern of fatty acid distribution in total lipid of liver and muscle from captive and wild fish was similar. However, the relative percentage of specific fatty acids differed in captive and wild fish. The most noteworthy difference was the lower proportion of arachidonic acid (20:4n-6, AA) and the higher proportion of eicosapentaenoic acid (20:5n-3, EPA) in liver and muscle of captive fish with respect to those of wild fish. The proportion of docosahexaenoic acid (22:6n-3, DHA) did not differ between the two fish groups. The differences in EPA and AA proportions between captive and wild fish implied that captive fish presented a higher EPA/AA ratio and a lower DHA/EPA ratio than wild fish. In general terms, in both liver and muscle, the differences in fatty acid composition observed for TL were extended to all lipid classes. The results suggest that the different AA, EPA and DHA proportions in liver and muscle between captive and wild broodstocks are attributed to different levels of these fatty acids in broodstock diets.
Aquaculture Research, 2011
The present study examines the total lipid (TL) and fatty acid (FA) composition in eggs of brill ... more The present study examines the total lipid (TL) and fatty acid (FA) composition in eggs of brill Scophthalmus rhombus L. and the possible relationships with their quality parameters. Wild broodstocks were caught and maintained in captivity until eggs were collected. A lipid characterization of each egg batch was conducted in TL, lipid classes (LC) and FA of TL. The TL content was lower than the values reported for other £at¢sh species, showing high levels of sterol esters (SE). High viability rates were related to higher lipid reserves. Higher cholesterol (CHO) was linked to higher egg viability, whereas SE could have an opposite e¡ect. Comparison of female quality showed that lipid composition was more related to egg batches than to individual females. However, multivariate analysis did not show a clear correlation between lipid composition and brill egg quality, neither as individual components nor as a whole pro¢le of LC or FA. Our results suggest that some lipid components (phosphatidylcholine, CHO, SE, monounsaturated, eicosapentaenoic acid) could be related to di¡erences in spawning quality, although these were not the only factors involved in these di¡erences. Thus, these lipid components could be considered to be descriptors of the di¡erences found in the rates of brill quality.
Aquaculture Research, 2012
ABSTRACT Brill (Scophthalmus rhombus L.) is a flatfish considered of special interest for aquacul... more ABSTRACT Brill (Scophthalmus rhombus L.) is a flatfish considered of special interest for aquaculture diversification, but the high mortality observed during the early larval rearing is the main obstacle to commercial culture. The objective of this study was to contribute to the knowledge of nutrient utilization of early‐hatched larvae, characterizing the changes in lipid and protein contents during embryogenesis and the yolk‐sac larval stage of S. rhombus. Total lipid, lipid classes and fatty acid contents remained constant during embryogenesis and yolk‐sac larval development, except for phosphatidylethanolamine and phosphatidylinositol, which increased in quantity during the yolk‐sac larval stage. On the other hand, total protein (including non‐protein nitrogen) and amino acids decreased their contents in both periods, especially at hatching. The decrease only in the serine, glutamic acid, proline and lysine contents during embryogenesis suggests a selective use of amino acids during this phase. Unlike embryogenesis, amino acids loss during hatching appears to be non‐selective, and almost all amino acids (essential and non‐essential) decreased. Our results suggest that there is higher catabolism of protein vs. lipid during embryogenesis and the yolk‐sac larval stage of S. rhombus.
Aquaculture Nutrition, 2009
ABSTRACT The effects of feeding three natural frozen diets, grass shrimp (Palaemonetes sp.), cray... more ABSTRACT The effects of feeding three natural frozen diets, grass shrimp (Palaemonetes sp.), crayfish (Procambarus clarkii) and fish (Sardina pilchardus) and two semi-humid artificial diets (based on fish or shrimp powder) to the cuttlefish, Sepia officinalis, were analysed. Growth rate and feeding rate [FR; % body weight (BW) day−1] and food conversions (FC, %) were determined. Cuttlefish fed shrimp grew larger (3.8% BW day−1) and had the highest FC, followed by those fed crayfish, and sardine. The highest FR was obtained for cuttlefish fed crayfish (10.5% BW day−1). Although both artificial diets were accepted, none produced growth. Digestive gland-to-body weight ratio (DG/BW ratio) was calculated for animals fed each diet. A positive correlation (r = 0.94) between cuttlefish ingestion FR and DG weight was obtained. Mortality occurred mainly during the last week, and some cannibalism occurred among cuttlefish fed artificial diets. Finally, lipid composition of diets, DG and mantle of each group were analysed. Sardine diet was characterized by high levels of triacylglycerol (TG), whereas the main difference between shrimp and crayfish was the higher n-3/n-6 ratio found in shrimp. Changes in the lipid composition of DG were related to diet, but did not correlate with growth data. A strong loss of TG in the DG of artificial diets groups was notable. No differences in mantle lipid composition among the natural diets were found, but artificial diet groups showed higher contents of neutral lipids in their mantle respect to natural diets. According to results obtained, crayfish (P. clarkii) could be used as an alternative prey for rearing S. officinalis compared with shrimp. Artificial diets showed the worst effects in growth and mortality as well as the stronger influence on DG and mantle lipid composition of cuttlefish.
Aquaculture Nutrition, 2009
The present work reports a characterization of mean wet weight and moisture, the lipid class and ... more The present work reports a characterization of mean wet weight and moisture, the lipid class and fatty acid (FA) composition from the total lipids (TL), of both culture and wild eggs of the cuttlefish, Sepia officinalis, throughout the embryonic development. Additionally, reproductive data, such as the number of spawnings, number and mean weight of eggs and duration of spawning period of cultured cuttlefish is provided. Both types of eggs were similar in mean wet weight, moisture content, TL content and lipid composition throughout embryonic development. Females from the cultured group spawned 13 times and laid 8654 eggs in 64 days, with a mean weight of 0.607 ± 0.179 g. A sex ratio of 1.57 (11$ for 7#) promoted an individual fecundity of 787 eggs/$ (the biggest until now on our culture facilities), which might be related to increased bottom areas. The TL increased with day/stage of embryonic development (P < 0.05) only in the cultured egg group. However, no differences were found on TL between culture and wild eggs at the same day/stage (P > 0.05). Eggs displayed predominant levels of phosphatidylcholine, phosphatidylethanolamine (PE), cholesterol and triacylglycerol at the end of embryonic development. Polar and neutral lipids of both eggs groups remained consistently proportional (50% for each lipid fraction) and a significant increase (P < 0.05) was observed in phosphatidylserine, PE and free FA throughout the embryonic development. In either egg type and day, 16:0, 18:0, 20:5n-3 and 22:6n-3 accounted for approximately 70 g Kg )1 of all FA and saturated and n-3 totals seemed to have the same proportion in the cuttlefish eggs. The present results suggest that lipids are not used as energetic substrate but as structural components in cuttlefish egg.
Aquaculture, 2006
In the present study, cuttlefish (Sepia officinalis) aged 60-day-old (age-group I) and 120-day-ol... more In the present study, cuttlefish (Sepia officinalis) aged 60-day-old (age-group I) and 120-day-old (age-group II) were fed with live shrimp and live fish fry for 60 days, in order to study the diet influence on growth, mantle lipid composition, and astaxanthin content in the skin. The most noteworthy difference was the higher growth observed in shrimp-fed cuttlefish with respect to fishfed cuttlefish in both age groups. Total lipids (TL), lipid classes (LC) and their associated fatty acids (FA) from both diets and mantle of cuttlefish were analysed. The lipid profiles of both diets were clearly different in their LC distribution, with higher levels of Polar Lipids (PL) in shrimp with respect to fish fry. However, both diets did not show outstanding differences in the FA composition of TL except for 20:5n-3 (EPA), which was higher in shrimp than in fish fry. With respect to lipid composition of cuttlefish mantle, the TL content and cholesterol (CHO) percentage increased with age, while phosphatidylinositol (PI) and phosphatidylcholine (PC) percentage decreased. On the other hand, phosphatidylserine (PS), phosphatidylethanolamine (PE) and PC percentages in both cuttlefish age groups were also affected by the different diets, although this difference was higher in agegroup I. The general pattern of fatty acid composition of TL in the mantle of cuttlefish was similar in all groups studied. It is remarkable the low levels of monoene FAs in both age-group cuttlefish mantle, despite of the high level of this FA group in both diets, which suggests that these FAs are not stored in the mantle. An opposite tendency was observed regarding the n-3 HUFA, especially 22:6n-3 (DHA) which remained constant despite the different age or diet. High levels of astaxanthin were found in shrimp with respect to fish, but this was only reflected on skin accumulation in age-group I, showing no differences in age-group II. This suggests differences in the astaxanthin metabolism according to the age. The results suggest that the growth differences observed in shrimp-fed cuttlefish with respect to fish-fed cuttlefish were not reflected in outstanding differences in mantle composition.
Aquaculture, 2003
The fatty acid composition of ovaries from wild white sea bream and ovaries and eggs of captive w... more The fatty acid composition of ovaries from wild white sea bream and ovaries and eggs of captive white sea bream were investigated to estimate the fatty acid requirements of this species. The total lipid (TL) content in wild fish ovaries was similar to that found in ovaries and eggs ...
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Papers by Antonio Lorenzo