Intrusion of Oceanic-type Basaltic Melts Precedes Continental Break up in the Red Sea Rift

The role of magmatism in continental rifting and break up and in the birth of a new ocean are not well understood. Continental break up can take place with intense and voluminous volcanism, as in the Southern Red Sea/Afar Rift, or in a relatively amagmatic mode, as in the Mesozoic Iberian Atlantic rift. Studies of gabbros from the Brothers and Zabargad islands suggest that continental break up in the northern Red Sea, a relatively non-volcanic rift, is preceded by intrusion of oceanic-type basaltic melts that crystallize at progressively shallower crustal depths as rifting progresses towards continental break-up. A seismic reflection profile running across the central part of the southern Thetis basin, shows a ∼5 km wide reflector ∼1.25 s below the axial neovolcanic zone. We interpret it as marking the roof of a magma chamber or melt lens, similar to those identified below several mid-ocean ridges. Assuming a 4.5 km/s acoustic velocity for the upper oceanic crust at Thetis, this reflector is ∼3.5 km below the seafloor. The presence of a few kilometers deep subrift magma chamber soon after the initiation of oceanic spreading implies the crystallization of lower oceanic crust intrusives as a last step in a sequence of basaltic melt intrusion from pre-oceanic continental rifting to oceanic spreading. Thus, oceanic crust accretion in the Red Sea rift starts at depth before continental break up, emplacement of oceanic basalt at the sea floor, and development of Vine- Matthews magnetic anomalies, pointing to a rift model, where the lower continental lithosphere has been replaced by upwelling asthenosphere before continental rupturing. This model would imply depth-dependent extension due to decoupling between the upper and lower lithosphere with mantle-lithosphere-necking breakup before crustalnecking breakup. This mode of initial oceanic crust accretion may have been common in Mesozoic Atlantic-type rifts, in addition to wider, amagmatic, Iberian-type continent-ocean zones of transition

The neuron-astrocyte-microglia triad in a rat model of chronic cerebral hypoperfusion: Protective effect of dipyridamole

Chronic cerebral hypoperfusion during aging may cause progressive neurodegeneration as ischemic conditions persist. Proper functioning of the interplay between neurons and glia is fundamental for the functional organization of the brain. The aim of our research was to study the pathophysiological mechanisms, and particularly the derangement of the interplay between neurons and astrocytes-microglia with the formation of triads, in a model of chronic cerebral hypoperfusion induced by the 2-vessel occlusion (2VO) in adult Wistar rats (n=15). The protective effect of dipyridamole given during the early phases after 2VO (4 mg/kg/day i.v., the first 7 days after 2VO) was verified (n=15). Sham-operated rats (n=15) were used as controls. Immunofluorescent triple staining of neurons (NeuN), astrocytes (GFAP) and microglia (IBA1) was performed 90 days after 2VO. We found significantly higher amount of ectopic neurons, neuronal debris and apoptotic neurons in CA1 Str. Radiatum and Str. Pyramidale of 2VO rats. In CA1 Str. Radiatum of 2VO rats the amount of astrocytes (cells/mm2) did not increase. In some instances several astrocytes surrounded ectopic neurons and formed a micro scar around them. Astrocyte branches could infiltrate the cell body of ectopic neurons, and, together with activated microglia cells formed the triads. In the triad, significantly more numerous in CA1 Str. Radiatum of 2VO than in sham rats, astrocytes and microglia cooperated in the phagocytosis of ectopic neurons. These events might be common mechanisms underlying many neurodegenerative processes. The frequency to which they appear might depend upon, or might be the cause of, the burden and severity of neurodegeneration. Dypiridamole significantly reverted all the above described events. The protective effect of chronic administration of dipyridamole might be a consequence of its vasodilatory, antioxidant and anti-inflammatory role during the early phases after 2VO

Combined Orthoplastic Approach in Fracture-Related Infections of the Distal Tibia

This series reports on the treatment of distal tibia (DT) fracture-related infections (FRI) with a combined orthoplastic approach. Thirteen patients were included. In eight patients with extensive bone involvement and in those with a non-healed fracture, the DT was resected ("staged approach"). In five cases, the DT was preserved ("single-stage approach"). A wide debridement was performed, and the cavity was filled with antibiotic-loaded PerOssal beads. All patients had a soft-tissue defect covered by a free vascularized flap (anterolateral thigh perforator flap in eight cases, latissimus dorsi flap in five). At the final follow-up (mean 25 months, range, 13-37), no infection recurrence was observed. In one patient, the persistence of infection was observed, and the patient underwent a repeated debridement. In two cases, a voluminous hematoma was observed. However, none of these complications impacted the final outcome. The successful treatment of FRI depends on proper debridement and obliteration of dead spaces with a flap. Therefore, when dealing with DT FRI, debridement of infected bone and soft tissues must be as radical as required, with no fear of the need for massive reconstructions

Reactive astrocyte COX2-PGE2 production inhibits oligodendrocyte maturation in neonatal white matter injury.

Inflammation is a major risk factor for neonatal white matter injury (NWMI), which is associated with later development of cerebral palsy. Although recent studies have demonstrated maturation arrest of oligodendrocyte progenitor cells (OPCs) in NWMI, the identity of inflammatory mediators with direct effects on OPCs has been unclear. Here, we investigated downstream effects of pro-inflammatory IL-1β to induce cyclooxygenase-2 (COX2) and prostaglandin E2 (PGE2) production in white matter. First, we assessed COX2 expression in human fetal brain and term neonatal brain affected by hypoxic-ischemic encephalopathy (HIE). In the developing human brain, COX2 was expressed in radial glia, microglia, and endothelial cells. In human term neonatal HIE cases with subcortical WMI, COX2 was strongly induced in reactive astrocytes with "A2" reactivity. Next, we show that OPCs express the EP1 receptor for PGE2, and PGE2 acts directly on OPCs to block maturation in vitro. Pharmacologic blockade with EP1-specific inhibitors (ONO-8711, SC-51089), or genetic deficiency of EP1 attenuated effects of PGE2. In an IL-1β-induced model of NWMI, astrocytes also exhibit "A2" reactivity and induce COX2. Furthermore, in vivo inhibition of COX2 with Nimesulide rescues hypomyelination and behavioral impairment. These findings suggest that neonatal white matter astrocytes can develop "A2" reactivity that contributes to OPC maturation arrest in NWMI through induction of COX2-PGE2 signaling, a pathway that can be targeted for neonatal neuroprotection

New insights on Celtic migration in Hungary and Italy through the analysis of non-metric dental traits

The Iron Age is characterized by an extended interweaving of movements by Celts in Europe. Several waves of Celts from Western and Central Europe migrated southeast and west from the core area of the La Téne culture (between Bourgogne and Bohemia). Through the analysis of non-metric dental traits, this work aims to understand the biological relationship among Celtic groups arrived in Italy and the Carpathian Basin, as well as between local populations and Celtic newcomers. A total of 10 non-metric dental traits were analyzed to evaluate biological affinities among Celts (Sopron-Krautacker and Pilismarót-Basaharc) and Scythians-related populations from Hungary (Tápiószele), Celts from continental Europe (Switzerland and Austria), two Iron Age Etruscan-Celtic sites from northern Italy (Monterenzio Vecchio and Monte Bibele), 13 Iron Age central-southern Italic necropolises, and the northern Italian Bronze Age necropolis of Scalvinetto. Strontium isotopes were measured on individuals from the necropolis of Monte Bibele to infer their local or non-local origin. Results highlight the existence of statistically significant differences between Celts and autochthonous Italian groups. Celtic groups from Hungary and Italy (i.e., non-local individuals of Monterenzio Vecchio and Monte Bibele) share a similar biological background, supporting the historical records mentioning a common origin for Celts migrated to the eastern and southern borders of today’s Europe. The presence of a supposed Steppean ancestry both in Celts from Hungary and Celts from northern Italy corroborates the hypothesis of the existence of a westward migration of individuals and genes from the Steppe towards northern Italy during the Bronze and Iron Age, which contributed to the biological variability of pre-Celtic and later Celtic populations, respectively. Conversely, individuals from central-southern Italy show an autochthonous pre-Iron Age background. Lastly, this work supports the existence of Celtic migratory routes in northern Italy, as shown by biological and cultural admixture between Celts and Italics living together.E.P. was funded from the Erasmus+ Traineeship Program/KA103, Agreement n. 2020-1-IT02-KA103-078332. T.H. and K.G. were supported by the Hungarian Scientific Research Fund (FK128013), the Bolyai Scholarship granted by the Hungarian Academy of Sciences and the ÚNKP-22-5 New National Excellence Program of the Ministry for Culture and Innovation from the source of the National Research, Development and Innovation Fund. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Vitamin D and Its Relationship with Obesity and Muscle

The skin synthesis of vitamin D represents the first step of a metabolic pathway whose features have been extensively studied and clarified in the last decades. In particular, the production of active and inactive forms of the hormone and the actions of the corresponding enzymes have offered new insights into the knowledge of vitamin D metabolism. Additionally, the description of the different organs and tissues expressing the vitamin D receptor and its possible functions, as well as its genetic determinants, have allowed focusing on the interrelationship between vitamin D and many physiological and pathological functions. In this context, many studies reported the association between vitamin D and adipose tissue metabolism, as well as the possible role of the hormone in obesity, weight, and fat mass distribution. Finally, many reports focused on the vitamin D-related effects on skeletal muscle, particularly on the mechanisms by which vitamin D could directly affect muscle mass and strength. This paper is mainly aimed to review vitamin D metabolism and its relationship with obesity and skeletal muscle function