87 research outputs found
Efectul sinergic al obezității asupra sistemului limfatic
Catedra Histologie, citologie și embriologie , USMF „Nicolae
Testemiţanu” Chișinău, Republica MoldovaIntroducere
Sistemul limfatic - deține un rol important
în homeostazia fluidelor, transportarea
macromoleculelor, reglarea și modelarea
răspunsului imun. Scopul lucrării
Studierea literaturii de specialitate referitoare la morfologie
și modificări ale sistemului limfatic în obezitate.
Materiale și metode
Au fost analizate 20 articole din bazele de date Pubmed,
CrossRef, folosind cuvintele de căutare „lymphatic vessels
in obesity”, „lymphatics in adipose tissue”.
Rezultate
Examenul histopatologic al șoarecelui
normostenic și a celui obez a pus în evidență
faptul că
disfuncția limfatică
cauzată de obezitate
sporește inflamația
și depozitele de
Adipocite. Concluzii
Actualmente este demonstrată relația de interdependență între
obezitate și disfuncție limfatică
Late Holocene microfaunal and nannofloral assemblages of the NW Black Sea
Abstract. This study describes the fluctuation pattern in Late Holocene microfaunal (i.e. foraminifera and ostracods) and nannofloral assemblages of
two cores collected from the Romanian Black Sea shelf, at a water depth of 28 and 66 m, respectively. The lithology of the cores is mainly characterised by
blackish muds, alternating with thin, centimetres-thick sand and coquina layers. The microfaunas are dominated by brackish foraminiferal and ostracod
assemblages that are still common in the actual Black Sea communities, living nowadays at water salinity lower than 18 ‰. In the shallower water Site EF
08-01, the abundance ratio between Caspian and Mediterranean ostracods is 0.7, while in the deeper water Site BS 08-055, the abundance ratio between
Caspian and Mediterranean ostracods is 0.01. These data argue for the dominance of Mediterranean ostracod fauna with lower abundance in shallower
environments of the Black Sea and with a very high abundance in the deeper parts of the internal shelf, i.e., at a water depth of 66 m. Based on the calcareous
nannoplankton fluctuation, four Nannofloral Intervals were identified, which indicate a gradual salinity increase of the surface waters during the
deposition of the Late Holocene Shallow Unit. In the same interval, the benthic microfaunas (ostracods and foraminifers) argue for a more stable salinity
environment in the two studied cores from the Black Sea inner shelf
First record of Oceanic Anoxic Event 2 in the Eastern Carpathians: implications for chemostratigraphic and biostratigraphic correlations
This study aims to investigate a marlstone and claystone succession located at the southern end of the Eastern Carpathians, a region where oceanic anoxic event 2 (OAE2) has not been pointed out so far. Toward the upper half of this succession, a 17-cm-thick black shale was identified. The investigated depositional interval lies within the late Cenomanian–early Turonian, encompassing the UC3d up to UC7 nannofossil zones. The δ13C values fluctuated between 2.06‰ and 3.89‰, showing a positive isotope excursion that was assigned to OAE2. The δ13C isotope curve displays the following intervals: pre-excursion, first build-up, trough, second build-up, plateau, and post-excursion. Within the second build-up interval of OAE2, a substantial shift in CaCO3 values, accompanied by high concentrations of total organic carbon and a significant decline in the abundance and diversity of calcareous nannofossil assemblages, was observed. The nannofossil turnover related to OAE2 climax revealed predominance of Watznaueria barnesiae and temporary disappearance from the record of surface-water higher fertility taxa, such as Biscutum constans, Zeugrhabdotus erectus, and Discorhabdus ignotus. Above OAE2, peaks of Eprolithus floralis, followed by increased abundance of Eiffellithus turriseiffelii and Nannoconus spp., were identified. In the lower part of the studied succession (i.e., the upper Cenomanian UC3d nannofossil subzone), during the pre-excursion characterized by low δ13C values and less negative δ18O values, a small group of nannofossils more related to mid- and high-paleolatitudes, such as Crucibiscutum salebrosum, Repagulum parvidentatum, and Seribiscutum primitivum, is present, always showing a low abundance
Lago Mare and the Messinian Salinity Crisis: Evidence from the Alboran Sea (S. Spain)
International audienceThis paper provides a new environmental, sedimentological and stratigraphic context of the Lago Mare deposits from the North Alboran region and clarifies their chronologic location with respect to the Messinian Salinity Crisis. We present new micropaleontological data (dinoflagellate cysts, calcareous nannoplankton, planktonic foraminifers), correlated with field observations and offshore seismic interpretations. We show that the Lago Mare event known in three onshore localities (Río Mendelín near Malaga, Zorreras near Sorbas, Gafares near Níjar) follows the marine reflooding of the Mediterranean Basin which ended the Messinian Salinity Crisis. Chronologically, these Lago Mare deposits last from the latest Messinian to the early Zanclean. In fact, the first influx of Paratethyan- organisms is revealed by the dinoflagellate cyst record from near Malaga within a Gilbert-type fan delta overlying the Messinian Erosional Surface. Invading molluscs and/or ostracods may have persisted in lagoonal coastal areas more or less affected by discontinuous marine influxes (Sorbas and Níjar). The Malaga area is convenient for a paleogeographic and sedimentary reconstruction which shows the prevalent forcing of sea level changes during the time-interval 5.600-5.332 Ma at the difference of the usually solicited prevalent tectonics. The studied Lago Mare event is the third episode resulting in such a paleobiological assemblage in the Mediterranean region and corresponds to the final two-way water exchange at high sea level between the Mediterranean and the former Paratethys. It documents the onset of the modern marine circulation in the Mediterranean after the reflooding ending the Messinian Salinity Crisis
The legacy of the Tethys Ocean: Anoxic seas, evaporitic basins, and megalakes in the Cenozoic of Central Europe
At the end of the Eocene, the demise of the Tethys Ocean led to the formation of one of the largest anoxic seas in the last 50 million years of Earth history. This long-lived anoxic water body, named Paratethys, covered large parts of central Eurasia and functioned as a major carbon sink for 15-20 million years, characterised by the deposition of cherts, anoxic turbidites and black shales. The anoxic episode was followed by a phase of instable connectivity where full marine episodes alternated with evaporitic crises and lacustrine episodes, resulting in the deposition of marine molasses, evaporites and continental-lacustrine sediments. Finally, Paratethys transformed into a megalake that progressively filled with clastic sediments from the neighbouring mountain ranges. Paratethys was tectonically fragmented in numerous sub-basins that spread W-E from the Alpine and Carpathian orogens to the East European Platform. Most Paratethyan stratigraphic records from Central and Eastern European tectonically-active regions are not complete and thus hamper paleogeographic and paleoenvironmental reconstructions. The only exception is the Outer Carpathian Basin, located in the external part of the Carpathian arc in Central Europe, that preserved a complete record of Tethys demise and the rise and fall of Paratethys. The Outer Carpathians sedimentary successions show various lithologies that reflect an interplay of interbasinal connectivity and water exchange with the global ocean. Here we review the stratigraphic schemes of the different tectonic domains of the Outer Carpathians and describe the most complete records to produce a Carpathian-wide framework for the Eocene to Miocene evolution of Paratethys, the lost sea of Eurasia. Finally, we focus on the paleogeographic reconstructions of the interbasinal Paratethys connections and discuss how marine connectivity influenced anoxia and hypersalinity and impacted the Cenozoic depositional environments in central Europe
New Insights on the Sorbas Basin (SE Spain): the onshore reference of the Messinian Salinity Crisis
The Sorbas Basin is the land reference of the Messinian Salinity Crisis (MSC) that affected the Mediterranean Sea in the latest Miocene. Its stratigraphy has been re-visited using calcareous nannofossils and planktonic foraminifers, which provide a reliable biostratigraphic frame and lead to particularly specify the relationships between the Sorbas and Zorreras members with Yesares evaporites. The evaporites overlie a shallowing upward sequence ending with the deposition of the Reef Unit and Terminal Carbonate Complex (TCC) on the periphery of the basin. The reefal carbonates of the TCC are overlain by clastic deposits that are foreset beds of post-MSC Gilbert-type fan deltas developed on the northern edge of the basin. These sedimentary structures are separated from reefal carbonates and the Reef Unit by the Messinian Erosional Surface (MES). The various facies of the Sorbas Member have been correlated with the bottomset beds of the Gilbert-type fan deltas despite some differences in palaeobathymetry. In the southeastern periphery of the basin, the MES separates the Sorbas Member from the Yesares gypsums. In the central part of the basin, a hiatus characterizes the contact between these members. The Zorreras Member postdates the MSC and entirely belongs to Zanclean. Its white "Lago Mare" layers are lagoonal deposits, the fauna of which is confirmed to result from Mediterranean-Paratethys high sea-level exchange after the post-MSC marine reflooding of the Mediterranean Basin. This study allows to re-assert the two-step scenario of the MSC (Clauzon et al., 1996) with the following events: - at 5.971-5.600 Ma, minor sea-level fall resulting in the desiccation of this peripheral basin with secondary fluctuations; - at 5.600-5.460 Ma, significant subaerial erosion (or lack of sedimentation) caused by the almost complete desiccation of the Mediterranean Sea; - instantaneous marine reflooding, accepted at 5.460 Ma, followed by continuing sea-level rise
New insights on the Sorbas Basin (SE Spain): the onshore reference of the Messinian Salinity Crisis
International audienceThe Sorbas Basin is the land reference of the Messinian Salinity Crisis (MSC) that affected the Mediterranean Sea in the latest Miocene. Its stratigraphy has been re-visited using calcareous nannofossils and planktonic foraminifers, which provide a reliable biostratigraphic frame and lead to particularly specify the relationships between the Sorbas and Zorreras members with Yesares evaporites.The evaporites overlie a shallowing upward sequence ending with the deposition of the Reef Unit and Terminal Carbonate Complex (TCC) on the periphery of the basin. The reefal carbonates of the TCC are overlain by clastic deposits that are foreset beds of post-MSC Gilbert-type fan deltas developed on the northern edge of the basin. These sedimentary structures are separated from reefal carbonates and the Reef Unit by the Messinian Erosional Surface (MES). The various facies of the Sorbas Member have been correlated with the bottomset beds of the Gilbert-type fan deltas despite some differences in palaeobathymetry. In the southeastern periphery of the basin, the MES separates the Sorbas Member from the Yesares gypsums. In the central part of the basin, a hiatus characterizes the contact between these members. The Zorreras Member postdates the MSC and entirely belongs to Zanclean. Its white “Lago Mare” layers are lagoonal deposits, the fauna of which is confirmed to result from Mediterranean–Paratethys high sea-level exchange after the post-MSC marine reflooding of the Mediterranean Basin.This study allows to re-assert the two-step scenario of the MSC (Clauzon et al., 1996) with the following events:- at 5.971–5.600 Ma, minor sea-level fall resulting in the desiccation of this peripheral basin with secondary fluctuations;- at 5.600–5.460 Ma, significant subaerial erosion (or lack of sedimentation) caused by the almost complete desiccation of the Mediterranean Sea;- instantaneous marine reflooding, accepted at 5.460 Ma, followed by continuing sea-level rise
Efectul sinergic al obezității asupra sistemului limfatic
Department of Histology, Cytology and Embryology, Nicolae Testemitanu SUMPhBackground. The lymphatic system is a component of the cardiovascular system, it plays an important
role in fluid homeostasis, macromolecules transport, regulation, and modulation of the immune
response, as well as in fat absorption and cholesterol metabolism. Objective of the study. Review of
the scientific literature on morphology and changes of the lymphatic system in obesity. Material and
Methods. 20 articles from the Pubmed, CrossRef databases were analyzed using the search words
"lymphatic vessels in obesity", "lymphatics in adipose tissue". Results. Experimental studies have
shown that in obese mice there is a decreased density of lymphatic vessels in subcutaneous adipose
tissue, reduced proliferation of endothelial lymphatic cells, and decreased clearance of macromolecules.
The lymph nodes are also changed with T lymphocyte damage. Histopathological examination of the
normal weight and obese mice revealed that lymph vessel dysfunction caused by obesity increases the
degree of inflammation and deposition of adipocytes. Conclusion. The interdependent relationship
between obesity and lymphatic dysfunction is currently being demonstrated. The perception of these
mechanisms would allow the regulation of lymphatic functions and the development of a treatment that
will have a major impact on obese patients.Introducere. Sistemul limfatic - o componentă a sistemului cardiovascular, deține rol important în
homeostazia fluidelor, transportarea macromoleculelor, reglarea și modelarea răspunsului imun,
absorbția grăsimilor și metabolismul colesterolului. Scopul lucrării. Studierea literaturii de specialitate
referitoare la morfologia și modificările sistemului limfatic în obezitate. Material și Metode. Au fost
analizate 20 articole din bazele de date Pubmed, CrossRef, utilizând cuvintele de căutare „lymphatic
vessels in obesity”, „lymphatics in adipose tissue”. Rezultate. Studiile experimentale au demonstrat că,
la șoarecii obezi a scăzut densitatea limfatică în țesutul adipos subcutanat, s-a redus proliferarea celulelor
limfatice endoteliale, a scăzut clearance-ul macromoleculelor. S-au modificat și ganglionii limfatici, cu
afectarea limfocitelor T. Examenul histopatologic al șoarecelui normostenic și a celui obez a pus în
evidență faptul că disfuncția limfatică, cauzată de obezitate, amplifică inflamația și depozitele de
adipocite. Concluzii. Actualmente este demonstrată relația de interdependență între obezitate și
disfuncția limfatică. Perceperea acestor mecanisme ar permite reglarea funcțiilor limfatice și dezvoltarea
tratamentului, care va avea un impact major asupra pacienților obezi
CRETACEOUS-CENOZOIC PALEOBIOGEOGRAPHY OF THE SOUTHERN ROMANIAN BLACK SEA ONSHORE AND OFFSHORE AREAS
Abstract. Investigations carried out on 22 drillings on the Southern onshore area of the Romanian Black Sea and on one drilling from the Southern offshore area of the Romanian Black Sea are presented here. The lithological/sedimentological investigations and the micropalaeontological (calcareous nannoplankton) quantitative and qualitative analyses revealed several depositional sequences. The oldest identified sedimentary cycle is latest Jurassic Tithonian) - Early Cretaceous (Berriasian - Valanginian) in age and composed of marine shallow water carbonates. The next cycle, in stratigraphic order, is Barremian - Early Aptian in age, composed of marine shallow water carbonates. A fluvial-lacustrine formation, Middle - Late Aptian in age, was observed only in the drillings from onshore area. The youngest Cretaceous cycle (Santonian – Maastrichtian) is mainly composed of chalks, with intercalations of glauconitic sands towards the base. In the chalk offshore deposits of the Black Sea, a continuous sedimentation took place within the Cretaceous/Tertiary boundary interval. The Paleogene deposits (Middle – Late Eocene) are characterized by the presence of marlstones and claystones. These are overlain by Oligocene black shales, rich in organic matter and fish remains. Miocene, Pliocene and Pleistocene deposits were sedimented in a brackish environment, but several marine influxes probably occured (based on the nannofloras encountered) within the Middle Miocene, latest Miocene-earliest Pliocene and Late Pleistocene. The Cretaceous-Eocene nannofloras are dominated by warm water taxa (Tethyan nannofloras). The occurrence of the Cretaceous calcareous nannoplankton confined to high latitudes (Boreal taxa) within the Late Valanginian, the Barremian - Aptian boundary interval and the latest Maastrichtian, indicate cooler water surfaces. A more significant cooling could be assumed in the Early Oligocene, occuring at the same time with the separation of the Paratethys Realm, and with the appearance of endemic nannofloras in the Black Sea offshore area
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