Search results for "Embryon"

Chromosomal and genetic changes produced in tumoral progression of embryonal rhabdomyosarcoma

2013

La distribuzione dell'attività proteasica nella blastula e nella giovane gastrula diDiscoglossus pictus

1956

Summary Protease activity has been measured in the animal and vegetal half of the blastula and in the dorsal and ventral regions of the early gastrula of Discoglossus pictus. A higher protease activity was found in the dorsal region of the early gastrula, where presumptive chordamesoderm and presumptive neuroectoderm are localized.

Highly purified chondroitin sulfate: a literature review on clinical efficacy and pharmacoeconomic aspects in osteoarthritis treatment

2020

AbstractOsteoarthritis (OA) is the most prevalent musculoskeletal disease and a major cause of negative relevant outcomes, associated with an ever-increasing societal burden. Pharmaceutical-grade chondroitin sulfate (CS) was repeatedly reported to reduce pain and improve function in patients with OA. This article aims to review the evidence for the role of highly purified (hp) CS (Condrosulf®, IBSA) in the treatment of OA. We collected and reported evidence concerning (1) efficacy of hpCS 800 mg/day in the treatment of OA affecting the knee, hand and hip; (2) efficacy and safety of hpCS 1200 mg/day also in the oral gel formulation; (3) the safety profile of hpCS; (4) the difference of hpCS …

Effects of tributyltin chloride in ascidian embryos: modulation of kinase-mediated signalling pathways

2009

We studied the effects of various TBT concentrations by assaying the activity of ERK 1/2 (p44/42) and phospho-ERK1/2 (phospho-p44/42), proteins with a key role in ascidian development, and tyrosine kinase-dependent pathway. The effects of this xenobiotic and the role of some signalling mechanisms on ascidian embryos were examined by using Western immunoblotting. The tyrosine phosphorylation pattern in the ascidians Ciona intestinalis and Phallusia mammillata development was examined and different levels of protein phosphorylation were found as a response to TBT at μM range. To determine whether another key signalling pathway was activated, the effects of TBT on the phosphorylation state of …

Primary culture of avian embryonic heart forming region cells to study the regulation of vertebrate early heart morphogenesis by vitamin A

2014

Background: Important knowledge about the role of vitamin A in vertebrate heart development has been obtained using the vitamin A-deficient avian in ovo model which enables the in vivo examination of very early stages of vertebrate heart morphogenesis. These studies have revealed the critical role of the vitamin A-active form, retinoic acid (RA) in the regulation of several developmental genes, including the important growth regulatory factor, transforming growth factor-beta2 (TGFβ2), involved in early events of heart morphogenesis. However, this in ovo model is not readily available for elucidating details of molecular mechanisms determining RA activity, thus limiting further examination o…

Cáncer en los primeros 18 meses de vida

2020

Resumen: Introducción: La enfermedad oncohematológica continúa siendo la primera causa de mortalidad no traumática en la infancia y una importante causa de morbilidad. El paciente menor de 18 meses presenta particularidades clínicas, diagnósticas y terapéuticas que es interesante conocer por todo pediatra, con el fin de lograr una mayor supervivencia y una menor comorbilidad a lo largo de su vida. Material y métodos: Estudio descriptivo retrospectivo de variables clínicas, diagnósticas y terapéuticas en pacientes menores de 18 meses diagnosticados de enfermedad oncohematológica que reciben quimioterapia en una unidad de oncología pediátrica entre enero 2007 y agosto 2019. Resultados: Setent…

Starvation tolerance of rotifers produced from parthenogenetic eggs and from diapausing eggs: a life table approach

2006

Monogonont rotifers have to cope with environmental variation by producing diapausing stages.Cyclically, parthenogenetic rotifers produce females by (i) parthenogenetic eggs and (ii) sexuallyproduced eggs. Parthenogenetic eggs hatch shortly after ovoposition, frequently while they are carriedby their mothers. Sexual eggs go into dormancy and hatch in the sediment, in response to specificenvironmental cues. Therefore, it is expected that post-diapause and parthenogenetic offspring wouldface different environments. Moreover, resource allocation is higher in diapausing eggs than inparthenogenetic eggs. In this study, the response to starvation of females obtained from partheno-genetic eggs and …

Assessing the efficacy of direct conservation interventions: clutch protection of the leatherback marine turtle in the Dominican Republic

2014

AbstractThe beaches of Jaragua National Park in the Dominican Republic are the country's last known major nesting site for the leatherback marine turtle Dermochelys coriacea. This nesting aggregation is threatened by widespread illegal egg take, and clutch relocation and artificial incubation have been carried out as protection measures since 1974. We assess the efficacy of such efforts and investigate how artificial incubation may be influencing the success and sex ratios of clutches. We compare hatching success, incubation duration and embryo mortality in in-situ clutches (n = 43) with those incubated artificially at sites in the east and west of the Park (n = 35 and n = 31, respectively)…

Hatching and viability of rotifer diapausing eggs collected from pond sediments

2006

SUMMARY 1. Planktonic rotifers inhabiting variable environments produce diapausing eggs that accumulate in the sediment of lakes and ponds, forming egg banks that may withstand adverse periods. A common assumption in zooplankton diapausing egg bank studies is to count as viable all eggs in the sediment that look healthy. This assumption should be challenged by asking how effectively ‘healthy-looking’ eggs represent viable eggs. 2. In this study, viability of more than 1100 ‘healthy-looking’ diapausing eggs belonging to the Brachionus plicatilis species complex was assessed in a laboratory hatching experiment. Eggs were collected at different depths from sediment cores obtained from 15 ponds…

Joint brood guarding in parent bugs — an experiment on defence against predation

1995

Females of Elasmucha grisea defend their eggs and small nymphs against invertebrate predators. Females sometimes guard their clutches side by side on the same birch leaf. We studied benefits of this joint guarding both in the field and in the laboratory. We found that adjacent females had significantly larger clutches than solitary females. In the laboratory, we studied the effectiveness of joint versus single defence against ant (Formica uralensis) predators. We established female pairs from initially singly guarding females by cutting off pieces of leaves with egg clutches and pasting them beside another female guarding her clutch. In the control group the females with their clutches were…