193 research outputs found
Histochemical analysis of glycoconjugates in the domestic cat testis
The localization and characterization of
oligosaccharide sequences in the cat testis was
investigated using 12 lectins in combination with the ßelimination
reaction, N-Glycosidase F and sialidase
digestion. Leydig cells expressed O-linked glycans with
terminal aGalNAc (HPA reactivity) and N-glycans with
terminal/internal aMan (Con A affinity). The basement
membrane showed terminal Neu5Aca2,6Gal/GalNAc,
Galß1,3GalNAc, a/ßGalNAc, and GlcNAc (SNA, PNA,
HPA, SBA, GSA II reactivity) in O-linked oligosaccharides,
terminal Galß1,4GlcNAc (RCA120 staining)
and aMan in N-linked oligosaccharides; in addition,
terminal Neu5Aca2,3Galß1,4GlcNac, Forssman
pentasaccharide, aGal, aL-Fuc and internal GlcNAc
(MAL II, DBA, GSA I-B4, UEA I, KOH-sialidase-WGA
affinity) formed both O- and N-linked oligosaccharides.
The Sertoli cells cytoplasm contained terminal Neu5Ac-
Galß1,4GlcNAc, Neu5Ac-ßGalNAc as well as internal
GlcNAc in O-linked glycans, aMan in N-linked
glycoproteins and terminal Neu5Aca2,6Gal/
GalNAc in both O- and N-linked oligosaccharides.
Spermatogonia exhibited cytoplasmic N-linked
glycoproteins with aMan residues. The spermatocytes
cytoplasm expressed terminal Neu5Aca2,3Galß1,4
GlcNAc and Galß1,3GalNAc in O-linked oligosaccharides,
terminal Galß1,4GlcNAc and a/ßGalNAc
in N-linked glycoconjugates. The Golgi region showed
terminal Neu5aca2,3Galß1,4GlcNac, Galß1,4GlcNAc,
Forssman pentasaccharide, and aGalNAc in O-linked
oligosaccharides, aMan and terminal ßGal in N-linked
oligosaccharides. The acrosomes of Golgi-phase
spermatids expressed terminal Galß1,3GalNAc,
Galß1,4GlcNAc, Forssmann pentasaccharide,
a/ßGalNAc, aGal and internal GlcNAc in O-linked
oligosaccharides, terminal a/ßGalNAc, aGal and
terminal/internal aMan in N-linked glycoproteins. The
acrosomes of cap-phase spermatids lacked internal
Forssman pentasaccharide and aGal, while having
increased a/ßGalNAc. The acrosomes of elongated
spermatids did not show terminal Galß1,3GalNAc,
displayed terminal Galß1,4GlcNAc and a/ßGalNAc in
N-glycans and Neu5Ac-Galß1,3GalNAc in O-linked
oligosaccharides
High-Sensitivity C-Reactive Protein and Acute Kidney Injury in Patients with Acute Myocardial Infarction: A Prospective Observational Study
Background. Accumulating evidence suggests that inflammation plays a key role in acute kidney injury (AKI) pathogenesis. We explored the relationship between high-sensitivity C-reactive protein (hs-CRP) and AKI in acute myocardial infarction (AMI). Methods. We prospectively included 2,063 AMI patients in whom hs-CRP was measured at admission. AKI incidence and a clinical composite of in-hospital death, cardiogenic shock, and acute pulmonary edema were the study endpoints. Results. Two-hundred-thirty-four (11%) patients developed AKI. hs-CRP levels were higher in AKI patients (45 \ub1 87 vs. 16 \ub1 41 mg/L; p < 0.0001). The incidence and severity of AKI, as well as the rate of the composite endpoint, increased in parallel with hs-CRP quartiles (p for trend <0.0001 for all comparisons). A significant correlation was found between hs-CRP and the maximal increase of serum creatinine (R = 0.23; p < 0.0001). The AUC of hs-CRP for AKI prediction was 0.69 (p < 0.001). At reclassification analysis, addition of hs-CRP allowed to properly reclassify 14% of patients when added to creatinine and 8% of patients when added to a clinical model. Conclusions. In AMI, admission hs-CRP is closely associated with AKI development and severity, and with in-hospital outcomes. Future research should focus on whether prophylactic renal strategies in patients with high hs-CRP might prevent AKI and improve outcome
Brain morphology and immunohistochemical localization of the gonadotropin-releasing hormone in the bluefin tuna, <i>Thunnus thynnus</i>
The present study was focused on the morphology of the
diencephalic nuclei (likely involved in reproductive functions)
as well as on the distribution of GnRH (gonadotropin-releasing
hormone) in the rhinencephalon, telencephalon and the
diencephalon of the brain of bluefin tuna (Thunnus thynnus)
by means of immunohistochemistry. Bluefin tuna has an
encephalization quotient (QE) similar to that of other large
pelagic fish. Its brain exhibits well-developed optic tecta and
corpus cerebelli. The diencephalic neuron cell bodies
involved in reproductive functions are grouped in two main
nuclei: the nucleus preopticus-periventricularis and the
nucleus lateralis tuberis. The nucleus preopticus-periventricularis
consists of the nucleus periventricularis and the nucleus
preopticus consisting of a few sparse multipolar neurons
in the rostral part and numerous cells closely packed and
arranged in several layers in its aboral part. The nucleus lateralis
tuberis is located in the ventral-lateral area of the
diencephalon and is made up of a number of large multipolar
neurones.
Four different polyclonal primary antibodies against salmon
(s)GnRH, chicken (c)GnRH-II (cGnRH-II 675, cGnRH-II 6)
and sea bream (sb)GnRH were employed in the immunohistochemical
experiments. No immunoreactive structures were
found with anti sbGnRH serum. sGnRH and cGnRH-II antisera
revealed immunoreactivity in the perikarya of the olfactory
bulbs, preopticus-periventricular nucleus, oculomotor
nucleus and midbrain tegmentum. The nucleus lateralis
tuberis showed immunostaining only with anti-sGnRH serum.
Nerve fibres immunoreactive to cGnRH and sGnRH sera were
found in the olfactory bulbs, olfactory nerve and neurohypophysis.
The significance of the distribution of the GnRHimmunoreactive
neuronal structures is discussed
Wanted dead or alive : high diversity of macroinvertebrates associated with living and ’dead’ Posidonia oceanica matte
The Mediterranean endemic seagrass Posidonia
oceanica forms beds characterised by a dense leaf canopy
and a thick root-rhizome ‘matte’. Death of P. oceanica
shoots leads to exposure of the underlying matte, which
can persist for many years, and is termed ‘dead’ matte.
Traditionally, dead matte has been regarded as a degraded
habitat. To test whether this assumption was
true, the motile macroinvertebrates of adjacent living
(with shoots) and dead (without shoots) matte of
P. oceanica were sampled in four different plots located
at the same depth (5–6 m) in Mellieha Bay, Malta
(central Mediterranean). The total number of species
and abundance were significantly higher (ANOVA;
P<0.05 and P<0.01, respectively) in the dead matte
than in living P. oceanica matte, despite the presence of
the foliar canopy in the latter. Multivariate analysis
(MDS) clearly showed two main groups of assemblages,
corresponding to the two matte types. The amphipods
Leptocheirus guttatus and Maera grossimana, and the
polychaete Nereis rava contributed most to the dissimilarity
between the two different matte types. Several
unique properties of the dead matte contributing to the
unexpected higher number of species and abundance of
motile macroinvertebrates associated with this habitat
are discussed. The findings have important implications
for the conservation of bare P. oceanica matte, which
has been generally viewed as a habitat of low ecological
value.peer-reviewe
PCSK9 deficiency reduces insulin secretion and promotes glucose intolerance: the role of the low-density lipoprotein receptor
Aims
PCSK9 loss of function genetic variants are associated with lower low-density lipoprotein cholesterol but also with higher plasma glucose levels and increased risk of Type 2 diabetes mellitus. Here, we investigated the molecular mechanisms underlying this association.
Methods and results
Pcsk9 KO, WT, Pcsk9/Ldlr double KO (DKO), Ldlr KO, albumin AlbCre+/Pcsk9LoxP/LoxP (liver-selective Pcsk9 knock-out mice), and AlbCre-/Pcsk9LoxP/LoxP mice were used. GTT, ITT, insulin and C-peptide plasma levels, pancreas morphology, and cholesterol accumulation in pancreatic islets were studied in the different animal models. Glucose clearance was significantly impaired in Pcsk9 KO mice fed with a standard or a high-fat diet for 20\u2009weeks compared with WT animals; insulin sensitivity, however, was not affected. A detailed analysis of pancreas morphology of Pcsk9 KO mice vs. controls revealed larger islets with increased accumulation of cholesteryl esters, paralleled by increased insulin intracellular levels and decreased plasma insulin, and C-peptide levels. This phenotype was completely reverted in Pcsk9/Ldlr DKO mice implying the low-density lipoprotein receptor (LDLR) as the proprotein convertase subtilisin/kexin Type 9 (PCSK9) target responsible for the phenotype observed. Further studies in albumin AlbCre+/Pcsk9LoxP/LoxP mice, which lack detectable circulating PCSK9, also showed a complete recovery of the phenotype, thus indicating that circulating, liver-derived PCSK9, the principal target of monoclonal antibodies, does not impact beta-cell function and insulin secretion.
Conclusion
PCSK9 critically controls LDLR expression in pancreas perhaps contributing to the maintenance of a proper physiological balance to limit cholesterol overload in beta cells. This effect is independent of circulating PCSK9 and is probably related to locally produced PCSK9
Vitamin d plasma levels and in-hospital and 1-year outcomes in acute coronary syndromes : a prospective study
Deficiency in 25-hydroxyvitamin D (25[OH]D), the main circulating form of vitamin D in blood, could be involved in the pathogenesis of acute coronary syndromes (ACS). To date, however, the possible prognostic relevance of 25 (OH)D deficiency in ACS patients remains poorly defined. The purpose of this prospective study was to assess the association between 25 (OH)D levels, at hospital admission, with in-hospital and 1-year morbidity and mortality in an unselected cohort of ACS patients.We measured 25 (OH)D in 814 ACS patients at hospital presentation. Vitamin D serum levels >30\u200ang/mL were considered as normal; levels between 29 and 21\u200ang/mL were classified as insufficiency, and levels\u200a<\u200a20\u200ang/mL as deficiency. In-hospital and 1-year outcomes were evaluated according to 25 (OH)D level quartiles, using the lowest quartile as a reference.Ninety-three (11%) patients had normal 25 (OH)D levels, whereas 155 (19%) and 566 (70%) had vitamin D insufficiency and deficiency, respectively. The median 25 (OH)D level was similar in ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) patients (14.1 [IQR 9.0-21.9] ng/mL and 14.05 [IQR 9.1-22.05] ng/mL, respectively; P\u200a=\u200a.88). The lowest quartile of 25 (OH)D was associated with a higher risk for several in-hospital complications, including mortality. At a median follow-up of 366 (IQR 364-379) days, the lowest quartile of 25 (OH)D, after adjustment for the main confounding factors, remained significantly associated to 1-year mortality (P\u200a<\u200a.01). Similar results were obtained when STEMI and NSTEMI patients were considered separately.In ACS patients, severe vitamin D deficiency is independently associated with poor in-hospital and 1-year outcomes. Whether low vitamin D levels represent a risk marker or a risk factor in ACS remains to be elucidated
Spawning Behaviour and Post-spawning Migration Patterns of Atlantic Bluefin Tuna (Thunnus thynnus) Ascertained from Satellite Archival Tags
Versión del editor
Fin Spine Bone Resorption in Atlantic Bluefin Tuna, Thunnus thynnus, and Comparison between Wild and Captive-Reared Specimens
Bone resorption in the first spine of the first dorsal fin of Atlantic bluefin tuna (ABFT) has long been considered for age estimation studies. In the present paper spine bone resorpion was assessed in wild (aged 1 to 13 years) and captive-reared (aged 2 to 11 years) ABFT sampled from the Mediterranean Sea. Total surface (TS), solid surface (SS) and reabsorbed surface (RS) were measured in spine transverse sections in order to obtain proportions of SS and RS. The spine section surface was found to be isometrically correlated to the fish fork length by a power equation. The fraction of solid spine bone progressively decreased according to a logarithmic equation correlating SS/TS to both fish size and age. The values ranged from 57% in the smallest examined individuals to 37% in the largest specimens. This phenomenon was further enhanced in captive-reared ABFT where SS/TS was 22% in the largest measured specimen. The difference between the fraction of SS of wild and captive-reared ABFT was highly significant. In each year class from 1- to 7-year-old wild specimens, the fraction of spine reabsorbed surface was significantly higher in specimens collected from March to May than in those sampled during the rest of the year. In 4-year-old fish the normal SS increase during the summer did not occur, possibly coinciding with their first sexual maturity. According to the correlations between SS/TS and age, the rate of spine bone resorption was significantly higher, even almost double, in captive-reared specimens. This could be attributed to the wider context of systemic dysfunctions occurring in reared ABFT, and may be related to a number of factors, including nutritional deficiencies, alteration of endocrine profile, cortisol-induced stress, and loss of spine functions during locomotion in rearing conditions.Versión del editor4,411
Terrestrial biosphere changes over the last 120 kyr
A new global synthesis and biomization of long (> 40 kyr) pollen-data records is presented and used with simulations from the HadCM3 and FAMOUS climate models and the BIOME4 vegetation model to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial–interglacial cycle. Simulated biome distributions using BIOME4 driven by HadCM3 and FAMOUS at the global scale over time generally agree well with those inferred from pollen data. Global average areas of grassland and dry shrubland, desert, and tundra biomes show large-scale increases during the Last Glacial Maximum, between ca. 64 and 74 ka BP and cool substages of Marine Isotope Stage 5, at the expense of the tropical forest, warm-temperate forest, and temperate forest biomes. These changes are reflected in BIOME4 simulations of global net primary productivity, showing good agreement between the two models. Such changes are likely to affect terrestrial carbon storage, which in turn influences the stable carbon isotopic composition of seawater as terrestrial carbon is depleted in 13C
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