266 research outputs found
Immunopresence and functional activity of prostaglandin-endoperoxide synthases and nitric oxide synthases in bovine corpora lutea during diestrus
The aim of this study was to evaluate the occurrence and the activity of prostaglandin-endoperoxide synthase 1 (PTGS1), PTGS2, and endothelial, neuronal, and inducible nitric oxide synthase (e-, n-, and iNOS) in early, mid, late, and regressive corpora lutea (CL) of bovines during diestrus. PTGS1 immunoreactivitywas localised mainly in the cytoplasm of small luteal cells, whereas PTGS2 was detected in the cytoplasm of large luteal cells during early, mid, and late stages. The immunoexpression of all NOS isoforms was observed in the nuclei of luteal cells in the CL stages examined. PTGS1 enzyme activity was higher in late CL and lower in regressive ones; PTGS2 increased from early to late CL andlowered in regressive ones. Constitutive NOS enzymatic activity (eNOS plus nNOS) was higher in late CL and lower in regressive ones; iNOS was lower in regressive CL. These results support the idea that PTGSs and NOSs regulate the bovine CL life span mainly during the transition from the luteotrophic to the luteolytic phase
Apoptotic cell death in canine hair follicle
Apoptotic cell death is an essential homeostatic mechanism involved in the control of cellular turnover in a variety of adult tissues. Cytoplasmic and nuclear condensation morphologically define this process whose biochemical hallmark is extensive DNA fragmentation into discrete oligonucleosomic units. Hair follicle growth and regression has been shown to be correlated with apoptosis in humans, mice, rats and guinea pigs. The present study was carried out to evaluate its implication in canine hair biology in order to define the spatio-temporal relationship between apoptosis and the hair cycle in dogs. As assessed by terminal deoxy-nucleotidyl transferase-mediated d-UTP nick-end-labelling (TUNEL) and by basic histological and ultrastructural assays, apoptotic cells appeared both in the growing and in the regressing follicle epithelium showing the well characterized morphological features described in the previous relevant literature
Topographical localisation of glucidic residues and their variations in the canine zona pellucida during folliculogenesis.
In the present ultrastructural study, horseradish peroxidase-labelled lectins, in conjunction with antiperoxidase antibody and protein A-gold, were used to characterise and localise the oligosaccharide sequences of zona pellucida glycoproteins at different stages of follicular development in the canine ovary. Deacetylation and sialidase digestion were also performed before lectin cytochemistry. The zona pellucida of oocytes present in unilaminar primary follicles reacts with WGA- and RCA-I-lectins. The zona pellucida of oocytes present in bilaminar and trilaminar secondary follicles displays positivity to WGA, RCA-I, Con-A, UEA-I, and sialidase/SBA. This labelling pattern persists in the zona pellucida of oocytes present in antral tertiary follicles with the exception of WGA and RCA-I reactive sites which are differently distributed throughout the zona pellucida. The topographical distribution of these carbohydrates is not uniform throughout the zona pellucida, indicating the regionalization of oligosaccharide chains within three concentric bands of the zona matrix: an inner surface close to the oocyte plasma membrane, an intermediate portion and an outer layer in contact with the follicular cells. Our results demonstrated variations in the presence and distribution of the carbohydrate residues in the canine zona pellucida during different stages of follicular growth. We also observed the presence of vesicles in both the ooplasm and granulosa cells, showing a similar lectin binding pattern to that of the zona pellucida
Intrinsic direct role of dopamine in the regulation of rabbit (Oryctolagus cuniculus) corpora lutea: in vitro study
Dopamine (DA) is a catecholamine neurotransmitter that is distributed
in the brain and also in different peripheral organs. In particular,
DA receptors (DR) are expressed in luteal cells of various species, but
the intrinsic role of the DA/DRs system on corpora lutea (CL)
function is still unclear. The main objectives of the present study were
to examine in rabbit CL the gene expression of DRs and DA and their
immunolocalization, as well as the in vitro effects of DA on the
production of progesterone, PGE2, and PGF2a during early, mid, and
late luteal stages of pseudopregnancy. Immunoreactivity and gene
expression for DR type 1 (D1R) decreased while that for D3R
increased in luteal and blood vessel cells from early to late pseudopregnant
stages. DA immunopositivity was evidenced only in luteal
cells. DA and D1R agonist increased in vitro release of progesterone
and prostaglandin E2 (PGE2) by early CL, whereas DA and D3R
agonist decreased progesterone and increased PGF2a in vitro release by
mid and late CL. These results provide evidence that the DA/DR
system exerts a dual modulatory function in controlling the lifespan of
CL: the DA/D1R is luteotrophic, while the DA/D3R is luteolytic. The
present data shed new light on the physiological mechanisms regulating
luteal activity that might improve our ability to optimize
reproductive efficiency in mammal species, including humans
Severe postpartum sepsis with prolonged myocardial dysfunction: a case report
<p>Abstract</p> <p>Introduction</p> <p>Severe sepsis during pregnancy or in the postpartum period is a rare clinical event. In non obstetric surviving patients, the cardiovascular changes seen in sepsis and septic shock are fully reversible five to ten days after their onset. We report a case of septic myocardial dysfunction lasting longer than ten days. To the best of our knowledge, this is the first report of prolonged septic myocardial dysfunction in a parturient.</p> <p>Case presentation</p> <p>A 24 year old Hispanic woman with no previous medical history developed pyelonephritis and severe sepsis with prolonged myocardial dysfunction after a normal spontaneous vaginal delivery.</p> <p>Conclusions</p> <p>Septic myocardial dysfunction may be prolonged in parturients requiring longer term follow up and pharmacologic treatment.</p
Enhanced insulin sensitivity associated with provision of mono and polyunsaturated fatty acids in skeletal muscle cells involves counter modulation of PP2A
International audienceAims/Hypothesis: Reduced skeletal muscle insulin sensitivity is a feature associated with sustained exposure to excess saturated fatty acids (SFA), whereas mono and polyunsaturated fatty acids (MUFA and PUFA) not only improve insulin sensitivity but blunt SFA-induced insulin resistance. The mechanisms by which MUFAs and PUFAs institute these favourable changes remain unclear, but may involve stimulating insulin signalling by counter-modulation/repression of protein phosphatase 2A (PP2A). This study investigated the effects of oleic acid (OA; a MUFA), linoleic acid (LOA; a PUFA) and palmitate (PA; a SFA) in cultured myotubes and determined whether changes in insulin signalling can be attributed to PP2A regulation. Principal Findings: We treated cultured skeletal myotubes with unsaturated and saturated fatty acids and evaluated insulin signalling, phosphorylation and methylation status of the catalytic subunit of PP2A. Unlike PA, sustained incubation of rat or human myotubes with OA or LOA significantly enhanced Akt-and ERK1/2-directed insulin signalling. This was not due to heightened upstream IRS1 or PI3K signalling nor to changes in expression of proteins involved in proximal insulin signalling, but was associated with reduced dephosphorylation/inactivation of Akt and ERK1/2. Consistent with this, PA reduced PP2Ac demethylation and tyrosine 307 phosphorylation-events associated with PP2A activation. In contrast, OA and LOA strongly opposed these PA-induced changes in PP2Ac thus exerting a repressive effect on PP2A.Conclusions/Interpretation: Beneficial gains in insulin sensitivity and the ability of unsaturated fatty acids to oppose palmitate-induced insulin resistance in muscle cells may partly be accounted for by counter-modulation of PP2A
Determinants of weight, psychological status, food contemplation and lifestyle changes in patients with obesity during the COVID-19 lockdown: a nationwide survey using multiple correspondence analysis
Introduction The corona virus disease 2019 (COVID-19) pandemic forced most of the Italian population into lockdown from 11 March to 18 May 2020. A nationwide survey of Italian Clinical Nutrition and Dietetic Services (Obesity Centers or OCs) was carried out to assess the impact of lockdown restrictions on the physical and mental wellbeing of patients with obesity (PWO) who had follow-up appointments postponed due to lockdown restrictions and to compare determinants of weight gain before and after the pandemic. Methods We designed a structured 77-item questionnaire covering employment status, diet, physical activity and psychological aspects, that was disseminated through follow-up calls and online between 2 May and 25 June 2020. Data were analyzed by multiple correspondence analysis (MCA) and multiple linear regression. Results A total of 1,232 PWO from 26 OCs completed the questionnaires (72% female, mean age 50.2 +/- 14.2 years; mean BMI 34.7 +/- 7.6 kg/m(2); 41% obesity class II to III). During the lockdown, 48.8% gained, 27.1% lost, while the remainder (24.1%) maintained their weight. The mean weight change was +2.3 +/- 4.8 kg (in weight gainers: +4.0 +/- 2.4 kg; +4.2% +/- 5.4%). Approximately 37% of participants experienced increased emotional difficulties, mostly fear and dissatisfaction. Sixty-one percent reduced their physical activity (PA) and 55% experienced a change in sleep quality/quantity. The lack of online contact (37.5%) with the OC during lockdown strongly correlated with weight gain (p < 0.001). Using MCA, two main clusters were identified: those with unchanged or even improved lifestyles during lockdown (Cluster 1) and those with worse lifestyles during the same time (Cluster 2). The latter includes unemployed people experiencing depression, boredom, dissatisfaction and increased food contemplation and weight gain. Within Cluster 2, homemakers reported gaining weight and experiencing anger due to home confinement. Conclusions Among Italian PWO, work status, emotional dysregulation, and lack of online communication with OCs were determinants of weight gain during the lockdown period
High doses of medroxyprogesterone as the cause of disappearance of adherence of the zona pellucida to an oocyte
The zona pellucida (ZP) is an external glycoprotein membrane of oocytes of mammals and embryos in the early stage of their development. ZP first appears in growing ovarian follicles as an extracellular substance between the oocyte and granular cells. The zona pellucid markedly affects the development and maturation of the oocyte. The morphology of the ZP-oocyte complex allows a more precise determination of the oocyte maturity. According to numerous experimental studies, ZP is essential for preimplantation embryonic development of humans and other mammals. It prevents dispersion of blastomeres and enhances their mutual interactions. ZP is a dynamic structure responsible for the provision of nutrients to early forms of oocytes in mammals. The aim of the present study was untrastructural evaluation of the ZP-oocyte contact during inhibited ovulation. Female white rats (Wistar strain) received a suspension of medroxyprogesterone acetate (MPA) in incremental intramuscular bolus doses of 3.7 mg (therapeutic dose), 7.4 mg and 11.1 mg. The animals were decapitated 5 days after the administration of MPA. Ovarian sections were evaluated under a transmission electron microscope (TEM) Zeiss EM 900. Morphometric analysis of ZP was conducted using the cell imaging system by Olympus. In females exposed to therapeutic doses of MPA, ZP showed the structure of granular-fibrous reticulum of a medium electron density with single cytoplasmic processes originating from the surrounding structures. The oocyte cell membrane generated single, delicate processes directed toward ZP. Microvilli of the oocyte were short and thin. In the group receiving 7.4 mg of MPA, ZP had the structure of a delicate, loose granular-fibrous reticulum, and the oocyte cell membrane generated single microvilli directed toward ZP. In both those groups, the close ZP-oocyte contact was observed. Otherwise, in the group exposed to the highest MPA doses (11.1 mg), thicker and more numerous oocyte microvilli were found, which did not penetrate ZP matrix. They were dense, irregularly separated contour, forming a barrier between ZP and oocyte. The present findings are likely to suggest that MPA has inhibiting effects on the synthesis of binding proteins and causes the loss of the oocyte contact with ZP
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