Search results for "Cyst"
showing 10 items of 1960 documents
Polycystic ovary and gonadoblastoma in Turner's syndrome.
2007
Turner's syndrome (TS) is characterized by typical facial features, short stature, hypergonadotropic hypogonadism, streak gonads, infertility, hearth and kidney malformations. Typical karyotype is 45,X0; however, 6% of TS have mosaic patterns including Y chromosome or fragments of Y. This karyotype is a risk factor of developing a dysgerminoma in dysgenic gonads. Furthermore, rare cases of polycystic ovary are described in young-adult patients with TS. We describe the clinical case of a 12-year-old girl with TS treated with GH who showed a good response to treatment. She developed an ovary with histological polycystic pattern and a contralateral gonadoblastoma in the streak gonad. Laparosco…
Mature cystic teratoma of the ovary with struma and benign Brenner tumor: a case report with immunohistochemical characterization.
2002
Polycystic ovary syndrome
2016
Polycystic ovary syndrome (PCOS) affects 5-20% of women of reproductive age worldwide. The condition is characterized by hyperandrogenism, ovulatory dysfunction and polycystic ovarian morphology (PCOM) - with excessive androgen production by the ovaries being a key feature of PCOS. Metabolic dysfunction characterized by insulin resistance and compensatory hyperinsulinaemia is evident in the vast majority of affected individuals. PCOS increases the risk for type 2 diabetes mellitus, gestational diabetes and other pregnancy-related complications, venous thromboembolism, cerebrovascular and cardiovascular events and endometrial cancer. PCOS is a diagnosis of exclusion, based primarily on the p…
The Androgen Excess and PCOS Society criteria for the polycystic ovary syndrome: the complete task force report.
2009
Abstract OBJECTIVE: To review all available data and recommend a definition for polycystic ovary syndrome (PCOS) based on published peer-reviewed data, whether already in use or not, to guide clinical diagnosis and future research. DESIGN: Literature review and expert consensus. SETTING: Professional society. PATIENTS: None. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): A systematic review of the published peer-reviewed medical literature, by querying MEDLINE databases, to identify studies evaluating the epidemiology or phenotypic aspects of PCOS. RESULT(S): The Task Force drafted the initial report, following a consensus process via electronic communication, which was then reviewed and c…
Selective and sensitive colorimetric detection of the neurotransmitter serotonin based on the aggregation of bifunctionalised gold nanoparticles
2018
[EN] We report a simple, sensitive and selective method for the colorimetric detection of serotonin (5-HT) in aqueous media using bifunctionalized gold nanoparticles (AuNPs). The probe (1) consisted of AuNPs functionalised with dithiobis(succinimidylpropionate) (DSP) and N-acetyl-l-cysteine (NALC). DSP was chosen to react with the amino group of 5-HT, whereas NALC was chosen to bind the hydroxyl group in 5-HT through hydrogen bonding and electrostatic interactions. A double interaction between nanoparticles and the hydroxyl and the amino group of serotonin led to interparticle-crosslinking aggregation. This, resulted in a colour change from red to blue that can be observed by the naked eye.…
Redox regulation of enzymatic activity and proteolytic susceptibility of ribulose-1,5-bisphosphate carboxylase/oxygenase fromEuglena gracilis.
1992
The activity of ribulose-1,5-bisphosphate carboxylase/oxygenase fromEuglena gracilis decays steadily when exposed to agents that induce oxidative modification of cysteine residues (Cu(2+), benzofuroxan, disulfides, arsenite, oxidized ascorbate). Inactivation takes place with a concomitant loss of cysteine sulfhydryl groups and dimerization of large subunits of the enzyme. 40% activity loss induced by the vicinal thiol-reagent arsenite is caused by modification of a few neighbor residues while the almost complete inactivation achieved with disulfides is due to extensive oxidation leading to formation of mixed disulfides with critical cysteines of the protein. In most cases oxidative inactiva…
C172S Substitution in the Chloroplast-encoded Large Subunit Affects Stability and Stress-induced Turnover of Ribulose-1,5-bisphosphate Carboxylase/Ox…
1999
Previous work has indicated that the turnover of chloroplast ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1. 39) may be controlled by the redox state of certain cysteine residues. To test this hypothesis, directed mutagenesis and chloroplast transformation were employed to create a C172S substitution in the Rubisco large subunit of the green alga Chlamydomonas reinhardtii. The C172S mutant strain was not substantially different from the wild type with respect to growth rate, and the purified mutant enzyme had a normal circular dichroism spectrum. However, the mutant enzyme was inactivated faster than the wild-type enzyme at 40 and 50 degrees C. In contrast, C172S mutant …
Cysteines 449 and 459 modulate the reduction-oxidation conformational changes of ribulose 1.5-bisphosphate carboxylase/oxygenase and the translocatio…
2006
The role of cysteines 449 (Cys449) and 459 (Cys459) from the large subunit (LS) of ribulose 1-5-bisphosphate carboxylase/oxygenase (Rubisco) in the reduction-oxidation (redox) regulation of the enzyme was assessed by site-directed mutagenesis of these residues and chloroplast transformation of Chlamydomonas reinhardtii. In vitro studies indicated that mutations C449S, C459S or C449S/ C459S do not affect the activity and proteolytic susceptibility of the enzyme in the reduced state. However, when oxidized, the mutant enzymes differed from the wild type (WT), showing an increased resistance to inactivation and, in the case of the double mutant (DM), an altered structural conformation as refle…
Modification of the proteolytic fragmentation pattern upon oxidation of cysteines from ribulose 1,5-bisphosphate carboxylase/oxygenase.
2003
The proteolytic susceptibility of the native CO 2 -fixing photosynthetic enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (EC 4.1.1.39, Rubisco) has been shown to increase in vitro after oxidative treatments that affect cysteine thiols. A limited incubation of oxidized (pretreated with the disulfide cystamine) Rubisco from Chlamydomonas reinhardtii with subtilisin or proteinase K generated fragments of molecular mass about 53 kDa (band I in SDS-PAGE) and 47 kDa (band II) derived from the large subunit (55 kDa) of the enzyme. In contrast, proteolysis of the reduced Rubisco (pretreated with the free thiol cysteamine) produced only the 53 kDa band. The same fragmentation pattern was repr…
Increased susceptibility of ribulose-1,5-bisphosphate carboxylase/oxygenase to proteolytic degradation caused by oxidative treatments
1990
The susceptibility of the chloroplastic enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase to proteolysis by trypsin, chymotrypsin, proteinase K, and papain is enhanced by oxidative treatments including spontaneous oxidation of cysteines. Proteinases exhibit a high specificity for the oxidized inactive form of the carboxylase, cleaving its large subunit. Treatment of the inactive enzyme with dithiothreitol results in partial recovery of both carboxylase activity and resistance to proteolysis. This behavior may explain the specific degradation of ribulose-1,5-bisphosphate carboxylase/oxygenase that occurs in vivo during leaf senescence.