Search results for "Actine"

Bio-Sintering/Bio-Fusion of Silica in Sponge Spicules

2012

The synthesis of siliceous spicules in both demosponges and hexactinellids is enzymatically driven via silicatein. This enzyme exists both intra-spicularly and in the extra-spicular space. It catalyzes the formation of bio-silica constituting the silica lamellae that are formed during the appositional (layer-by-layer) growth of the spicules. The extent of (bio-silica forming) activity of silicatein from the demosponge Suberites domuncula measured in vitro reflects the amount of bio-silica required for the formation of spicules in vivo. It is shown that during growth and maturation of the spicules in demosponges a bio-fusion process occurs that results in an intra-spicular sintering of the s…

Flashing light in sponges through their siliceous fiber network: A new strategy of “neuronal transmission” in animals

2012

Sponges (phylum Porifera) represent a successful animal taxon that evolved prior to the Ediacaran-Cambrian boundary (542 million years ago). They have developed an almost complete array of cell- and tissue-based interaction systems necessary for the establishment of a functional, multicellular body. However, a network of neurons, one cell/tissue-communication system is missing in sponges. This fact is puzzling and enigmatic, because these animals possess receptors known to be involved in the nervous system in evolutionary younger animal phyla. As an example, the metabotropic glutamate/GABA-like receptor has been identified and cloned by us. Recently, we have identified a novel light transmi…

Impact of NTRK2, DRD2 and ACE polymorphisms on prolactin levels in antipsychotic-treated patients with first-episode psychosis.

2018

Background: Hyperprolactinemia is a common side-effect of antipsychotics (APs), which may trigger serious secondary problems and compromise the adherence to treatment which is crucial for prognosis, especially in patients presenting with a first-episode of psychosis (FEP). Aims: We evaluated, in some cases for the first time, the effect of polymorphisms in multiple candidate genes on serum prolactin (PRL) levels in an AP-treated FEP cohort recruited in the multicenter PEPs study (Phenotype − genotype and environmental interaction; Application of a predictive model in first psychotic episodes). Methods: PRL concentration was measured in serum from 222 patients. A total of 167 polymorphisms w…

Effect of Cabergoline on Metabolism in Prolactinomas.

2013

<b><i>Introduction:</i></b> Hyperprolactinemia has been implicated in the pathogenesis of obesity and glucose intolerance and is reportedly associated with an impaired metabolic profile. The current study aimed at investigating the effects of 12- and 60-month treatment with cabergoline (CAB) on metabolic syndrome (MetS) in patients with prolactinomas. <b><i>Patients and Methods:</i></b> 61 patients with prolactinomas (13 men, 48 women, 41 with microadenoma, 20 with macroadenoma), aged 34.4 ± 10.3 years, entered the study. In all patients, prolactin (PRL) and metabolic parameters were assessed at diagnosis and after 12 and 60 months of continuo…

GRANULOMATOUS MASTITIS DURING CHRONIC ANTIDEPRESSANT THERAPY: IS IT POSSIBLE A CONSERVATIVE THERAPEUTIC APPROACH?

2012

Granulomatous mastitis is a rare benign inflammatory disease of the breast with multiple etiologies such as tuberculosis, sarcoidosis, foreign body reaction, and mycotic and parasitic infections. In contrast, idiopathic granulomatous mastitis (IGM) is characterized by the presence of chronic granulomatous lobulitis in the absence of an obvious etiology. Clinically and radiologically it may mimic breast carcinoma and so awareness of surgeons, pathologists, and radiologists is essential to avoid unnecessary mastectomies. Cases of IGM are reported during antidepressant therapy in patients also showing high levels of prolactinemia. In these cases, we believe that surgical excision must be avoid…

Espressione di galactine nell'infiammazione e nella larva natante di Ciona intestinalis

2010

Molecular and functional analysis of the (6-4) photolyase from the hexactinellid Aphrocallistes vastus.

2003

The hexactinellid sponges (phylum Porifera) represent the phylogenetically oldest metazoans that evolved 570-750 million years ago. At this period exposure to ultraviolet (UV) light exceeded that of today and it may be assumed that this old taxon has developed a specific protection system against UV-caused DNA damage. A cDNA was isolated from the hexactinellid Aphrocallistes vastus which comprises high sequence similarity to genes encoding the protostomian and deuterostomian (6-4) photolyases. Subsequently functional studies were performed. It could be shown that the sponge gene, after transfection into mutated Escherichia coli, causes resistance of the bacteria against UV light. Recombinan…

Phylogenetic Position of the Hexactinellida Within the Phylum Porifera Based on the Amino Acid Sequence of the Protein Kinase C from Rhabdocalyptus d…

1998

Recent analyses of genes encoding proteins typical for multicellularity, especially adhesion molecules and receptors, favor the conclusion that all metazoan phyla, including the phylum Porifera (sponges), are of monophyletic origin. However, none of these data includes cDNA encoding a protein from the sponge class Hexactinellida. We have now isolated and characterized the cDNA encoding a protein kinase C, belonging to the C subfamily (cPKC), from the hexactinellid sponge Rhabdocalyptus dawsoni. The two conserved regions, the regulatory part with the pseudosubstrate site, the two zinc fingers, and the C2 domain, as well as the catalytic domain were used for phylogenetic analyses. Sequence al…

Bio-sintering processes in hexactinellid sponges: Fusion of bio-silica in giant basal spicules from Monorhaphis chuni☆

2009

The two sponge classes, Hexactinellida and Demospongiae, comprise a skeleton that is composed of siliceous skeletal elements (spicules). Spicule growth proceeds by appositional layering of lamellae that consist of silica nanoparticles, which are synthesized via the sponge-specific enzyme silicatein. While in demosponges during maturation the lamellae consolidate to a solid rod, the lamellar organization of hexactinellid spicules largely persists. However, the innermost lamellae, near the spicule core, can also fuse to a solid axial cylinder. Similar to the fusion of siliceous nanoparticles and lamella, in several hexactinellid species individual spicules unify during sintering-like processe…

Alterations of peripheral testosterone metabolism after induced hypoprolactinemia in patients with prostatic carcinoma

1979

In 12 patients with advanced prostatic carcinoma the effect of bromocriptine-induced hypoprolactinemia on the peripheral androgen metabolism was investigated after 3H-testosterone injection under conditions that each individual served as his own control. After a 5-day significant prolactin suppression, the elimination of 3H-label 1 h after testosterone injection was about 45% and equal to pre-bromocriptine values. The recovery of dihydrotestosterone separated by silica gel T.L.C., however, was significantly augmented, resulting in a marked decrease of the testosterone/dihydrotestosterone ratio from 12.2 to 6.3. This induced 5alpha-reductase activity after prolactin suppression is in accorda…