255 research outputs found
Postcranial remains of Fabrosauridae (Reptilia: Ornithischia) from the Stormberg of southern Africa
The postcranial skeletons of three fabrosaurids from the upper Elliot Formation "Red Beds" of the Stormberg Group in southern Africa are described. The material demonstrates details of fabrosaurid anatomy previously unknown, particularly a short, deep prepubic process which is undoubtedly primitive for the Ornithischia. Besides the short prepubis, fabrosaurids are characterized by 1) a reduced manus; 2) an ilium having a lateral extension of the supra-acetabular margin and a deep nearly vertical brevis shelf; and 3) an elongated hindlimb. Postcranial morphology excludes the fabrosaurids from the ancestry of the contemporaneous heterodontosaurids. Neither can the fabrosaurids be considered ancestral to the 'juvenile scelidosaurid' (BMNH R6704) as has been suggested. On the contrary, the 'scelidosaurid' is more primitive in structure than fabrosaurids. The assignment of Nanosaurus agilis Marsh to the Fabrosauridae is not substantiated after morphological comparisons between the postcranial material of both. The taxonomic status of Scutellosaurus lawleri is regarded as uncertain. The fabrosaurids are more similar to the Morrison Formation camptosaurids, than to Hypsilophodon. Finally, it is argued that ornithopods were not a basal stock for the phylogenesis of non-ornithopods but represent an independent radiation comparable to the other ornithischian suborders. The fabrosaurids were an early development of the ornithopod radiation itself
Impaired release of Vitamin D in dysfunctional adipose tissue: New cues on Vitamin D supplementation in obesity
Context:
Vitamin D accumulates in adipose tissue (AT) and vitamin D deficiency is frequent in obesity.
Objective:
We hypothesize that trafficking of vitamin D is altered in dysfunctional AT.
Design, Patients, Settings:
54 normal-weight and 67 obese males were recruited in a prospective study and randomly assigned to supplementation with 50 \ub5g/week 25-hydroxyvitamin-D3 (25(OH)D) or 150 \ub5g/week vitamin D3 for 1 year, raising dosage by 50% if vitamin D-sufficiency (serum 25(OH)D>50 nomol/l), was not achieved at 6 months; 97 subjects completed the study.
Methods:
Vitamin D3 (D3) and 25(OH)D were quantified by HPLC-MS in control and insulin-resistant (IR) 3T3-L1 cells and subcutaneous AT (SAT) from lean and obese subjects, incubated with or without adrenaline; expression of 25-hydroxylase (CYP27A1), 1\u3b1-hydroxylase (CYP27B1) and vitamin D receptor (VDR) were analysed by real-time PCR.
Results:
In IR adipocytes the uptake of D3 and 25(OH)D was higher, but after adrenaline stimulation, the decrement in D3 and 25(OH)D was stronger in control cells, which also showed increased expression of CYP27A1 and CYP27B1 and higher levels of 25(OH)D. In SAT from obese subjects, the adrenaline-induced release of D3 and 25(OH)D was blunted; in both IR cells and obese SAT, protein expression of \u3b22-adrenergic receptor was reduced. Supplementation with 25-hydroxyvitamin-D3 was more effective in achieving vitamin D sufficiency in obese, but not in normal weight subjects.
Conclusion:
Dysfunctional AT shows a reduced catecholamine-induced release of D3 and 25(OH)D, and altered activity of vitamin D-metabolizing enzymes, for these reasons supplementation with 25-hydroxyvitamin-D3 is more effective in obese individuals
Heat Sensing Receptor TRPV1 Is a Mediator of Thermotaxis in Human Spermatozoa
The molecular bases of sperm thermotaxis, the temperature-oriented cell motility, are currently under investigation. Thermal perception relies on a subclass of the transient receptor potential [TRP] channels, whose member TRPV1 is acknowledged as the heat sensing receptor. Here we investigated the involvement of TRPV1 in human sperm thermotaxis. We obtained semen samples from 16 normozoospermic subjects attending an infertility survey programme, testis biopsies from 6 patients with testicular germ cell cancer and testis fine needle aspirates from 6 patients with obstructive azoospermia undergoing assisted reproductive technologies. Expression of TRPV1 mRNA was assessed by RT-PCR. Protein expression of TRPV1 was determined by western blot, flow cytometry and immunofluorescence. Sperm motility was assessed by Sperm Class Analyser. Acrosome reaction, apoptosis and intracellular-Ca2+ content were assessed by flow cytometry. We found that TRPV1 mRNA and protein were highly expressed in the testis, in both Sertoli cells and germ-line cells. Moreover, compared to no-gradient controls at 31°C or 37°C (Ctrl 31°C and Ctrl 37°C respectively), sperm migration towards a temperature gradient of 31-37°C (T gradient) in non-capacitated conditions selected a higher number of cells (14,9 ± 4,2×106 cells T gradient vs 5,1± 0,3×106 cells Ctrl 31°C and 5,71±0,74×106 cells Ctrl 37°C; P = 0,039). Capacitation amplified the migrating capability towards the T gradient. Sperms migrated towards the T gradient showed enriched levels of both TRPV1 protein and mRNA. In addition, sperm cells were able to migrate toward a gradient of capsaicin, a specific agonist of TRPV1, whilst capsazepine, a specific agonist of TRPV1, blocked this effect. Finally, capsazepine severely blunted migration towards T gradient without abolishing. These results suggest that TRPV1 may represent a facilitating mediator of sperm thermotaxis
Role of miR-200c in myogenic differentiation impairment via p66Shc: implication in skeletal muscle regeneration of dystrophic mdx mice
Duchenne muscular dystrophy (DMD) is a genetic disease associated with mutations of Dystrophin gene that regulate myofiber integrity and muscle degeneration, characterized by oxidative stress increase. We previously published that reactive oxygen species (ROS) induce miR-200c that is responsible for apoptosis and senescence. Moreover, we demonstrated that miR-200c increases ROS production and phosphorylates p66Shc in Ser-36. p66Shc plays an important role in muscle differentiation; we previously showed that p66Shc(-/-) muscle satellite cells display lower oxidative stress levels and higher proliferation rate and differentiated faster than wild-type (wt) cells. Moreover, myogenic conversion, induced by MyoD overexpression, is more efficient in p66Shc(-/-) fibroblasts compared to wt cells. Herein, we report that miR-200c overexpression in cultured myoblasts impairs skeletal muscle differentiation. Further, its overexpression in differentiated myotubes decreases differentiation indexes. Moreover, anti-miR-200c treatment ameliorates myogenic differentiation. In keeping, we found that miR-200c and p66Shc Ser-36 phosphorylation increase in mdx muscles. In conclusion, miR-200c inhibits muscle differentiation, whereas its inhibition ameliorates differentiation and its expression levels are increased in mdx mice and in differentiated human myoblasts of DMD. Therefore, miR-200c might be responsible for muscle wasting and myotube loss, most probably via a p66Shc-dependent mechanism in a pathological disease such as DMD
SHBG(141-161) Domain-Peptide Stimulates GPRC6A-Mediated Response in Leydig and \u3b2-Langerhans cell lines
GPRC6A is acknowledged as a major regulator of energy metabolism and male fertility through the action of undercarboxylated osteocalcin (ucOCN), representing a possible therapeutic target. We recently showed that the sex hormone-binding globulin (SHBG) binds to GPRC6A through the likely involvement of the 141-161 domain. To confirm this model, here we investigated the possible binding and agonist activity of SHBG(141-161) domain-peptide (SHBG141-161) on GPRC6A. The binding of SHBG141-161 to GPRC6A and downstream dissociation from G\u3b1i(GDP) protein was computationally modelled. SHBG141-161 was obtained by solid-phase synthesis, characterized by circular dichroism (CD) and the receptor binding was assessed by displacement of ucOCN on HEK-293 cells transfected with GPRC6A gene. Agonist activity of SHBG141-161 was assessed on Leydig MA-10 and Langerhans \uf062-TC6 cell lines through the GPRC6A-mediated release of testosterone (T) and insulin. SHBG141-161 was predicted to bind to GPRC6A and to reduce the affinity for G\u3b1i(GDP) at computational level. Conformational properties and binding to GPRC6A of the synthetic SHBG141-161 were confirmed by CD and displacement experiments. SHBG141-161 stimulated cell secretion of T and insulin, with dose dependency from 10-13 to 10-11M for T release (respectively P=0,041 10-13M; P = 0,032 10-12M; P = 0,008 10-11M vs basal) and for 10-12 to 10-10M for insulin (respectively P=0,041 10-12M; P=0,007 10-11M; P=0,047 10-10M; P=0,045 vs basal). Blockade with anti GPRC6A IgG abolished the response to SHBG141-161, suggesting agonist specificity. SHBG141-161 showed stimulating activity on GPRC6A, representing a template peptide with possible therapeutic use for metabolic and endocrine disorder
Soil thermal conductivity from early TRT logs using an active hybrid optic fibre system
At the Molinella test site in Italy, a monitoring well has been equipped with a hybrid active optical fibre cable down to the depth of 100 m sealed with geothermal grouting. The cored borehole provided a full stratigraphic sequence of unconsolidated alluvial deposits. The cored material has been classified from a geotechnical point of view, and the thermal parameters of the most relevant lithologies have been directly measured. Active heating of the optical fibre cable has been provided by a constant heating power injected through copper wires contained within the cable structure. This way, not only the equivalent thermal conductivity of the entire stratigraphy but also the thermal conductivity at a spatial resolution of 1 m have been obtained. For each investigated layer, the thermal conductivity obtained from the distributed temperature measurements and the ones acquired using direct measurements are interpreted and compared
Dynamics of cellular states of fibro-adipogenic progenitors during myogenesis and muscular dystrophy
Fibro-adipogenic progenitors (FAPs) are currently defined by their anatomical position, expression of non-specific membrane-associated proteins, and ability to adopt multiple lineages in vitro. Gene expression analysis at single-cell level reveals that FAPs undergo dynamic transitions through a spectrum of cell states that can be identified by differential expression levels of Tie2 and Vcam1. Different patterns of Vcam1-negative Tie2highor Tie2lowand Tie2low/Vcam1-expressing FAPs are detected during neonatal myogenesis, response to acute injury and Duchenne Muscular Dystrophy (DMD). RNA\ua0sequencing analysis identified cell state-specific transcriptional profiles that predict functional interactions with satellite and inflammatory cells. In particular, Vcam1-expressing FAPs, which exhibit a pro-fibrotic expression profile, are transiently activated by acute injury in concomitance with the inflammatory response. Aberrant persistence of Vcam1-expressing FAPs is detected in DMD muscles or upon macrophage depletion, and is associated with muscle fibrosis, thereby revealing how disruption of inflammation-regulated FAPs dynamics leads to a pathogenic outcome
Potency of Netilmicin against Staphylococci Compared to Other Ophthalmic Antibiotics
Netilmicin is a potent and safe antibiotic with a very low incidence of resistance used as a topical ophthalmic medication in bacterial ocular infections. The aim of this study was to compare netilmicin’s Quotient of Inhibitions (QIs) and killing kinetics vs Staphylococci with other ophthalmic antimicrobials. Conjunctival and corneal QIs of netilmicin formulations, in single and multiple doses of administration, were compared with those of tobramycin, ofloxacin, levofloxacin and azithromycin preparations. The same analysis was performed in human tears, comparing netilmicin eye drops solution with tobramycin ofloxacin and levofloxacin. Furthermore, killing kinetics against Staphylococci (ATCC strains and ocular isolates) of the above-cited antibiotics, as well as chloramphenicol, were compared at different time points. QI results showed that in the conjunctiva, netilmicin, in both single and multiple doses of administration, is highly effective against all staphylococcal strains tested, while in the cornea it was particularly active against methicillin-resistant Staphylococci strains. Moreover, in human tears, netilmicin eye drops solution showed a more favourable QI against Staphylococci than tobramycin, ofloxacin and levofloxacin all in single-dose administration regimen. Killing kinetic results showed that netilmicin has a great bactericidal activity vs all the microbe strains tested as netilmicin showed to be almost the most active antibiotic. Results suggest that netilmicin has one of the most favourable killing kinetic and tissue inhibitory effects against Staphylococci than the principal ophthalmic antibiotics on the market
The Anatomy of Asilisaurus kongwe, a Dinosauriform from the Lifua Member of the Manda Beds (~Middle Triassic) of Africa
The diagnosis of Dinosauria and interrelationships of the earliest dinosaurs relies on careful documentation of the anatomy of their closest relatives. These close relatives, or dinosaur “precursors,” are typically only documented by a handful of fossils from across Pangea and nearly all specimens are typically missing important regions (e.g., forelimbs, pelves, skulls) that appear to be important to help resolving the relationships of dinosaurs. Here, we fully describe the known skeletal elements of Asilisaurus kongwe, a dinosauriform from the Middle Triassic Manda Beds of the Ruhuhu Basin of Tanzania. The taxon is known from many disarticulated and partially articulated remains and, most importantly, from a spectacularly preserved associated skeleton of an individual containing much of the skull, pectoral and pelvic girdles, forelimb and hindlimb, and parts of the vertebral column including much of the tail. The unprecedented detail of the anatomy indicates that Asilisaurus kongwe had a unique skull that was short and had both a premaxillary and dentary edentulous margin, but retained a number of character states plesiomorphic for Archosauria, including a crocodylian-like ankle configuration and a rather short foot with well-developed metatarsals I and V. Additionally, character states present across the skeleton of Asilisaurus kongwe suggest it is more closely related to Silesaurus opolensis than to dinosaurs; thus suggesting high homoplasy and parallel trends within Silesauridae and within lineages of early dinosaurs. The anatomy of Asilisaurus kongwe and detailed description of early members of clades found outside Dinosauria are clearly needed to untangle the seemingly complex character evolution of the skeleton within avemetatarsalians.Fil: Nesbitt, Sterling J.. Virginia Polytechnic Institute; Estados UnidosFil: Langer, Max C.. Universidade de Sao Paulo; BrasilFil: Ezcurra, Martin Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin
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