Search results for "Yolk"

Crustacean Hemolymph Lipoproteins

2020

Lipoproteins mediate the transport of apolar lipids in the hydrophilic environment of physiological fluids such as the vertebrate blood and the arthropod hemolymph. In this overview, we will focus on the hemolymph lipoproteins in Crustacea that have received most attention during the last years: the high density lipoprotein/β-glucan binding proteins (HDL-BGBPs), the vitellogenins (VGs), the clotting proteins (CPs) and the more recently discovered large discoidal lipoproteins (dLPs). VGs are female specific lipoproteins which supply both proteins and lipids as storage material for the oocyte for later use by the developing embryo. Unusual within the invertebrates, the crustacean yolk protein…

2021

In fish, the lipid resources of the female form a link between the environment and progeny, contributing to the contents of the egg yolk. Variation of the environmental conditions is therefore expected to affect the egg quality via maternal pathways, reflecting the female’s response to the environmental factors before spawning. We investigated the content of lipids and thyroid hormones in the ovary and eggs of the Baltic herring during 1988–2019, when salinity of the Baltic Sea first declined and then stabilized to a lower level, and winters varied between severe and mild. The total lipid resources of spawning females decreased by 40–50% during the study, and the ovarian lipid concentration…

Ovarian Endometrioid-like Yolk Sac Tumor Treated by Surgery Alone, with Recurrence at 12 Years

1999

Abstract We describe the case of a stage Ia endometrioid-like yolk sac tumor (YST) of the ovary, which was originally misdiagnosed as a malignant struma ovarii and not treated with adjuvant chemotherapy. After 12 years, a contralateral dermoid cyst was excised along with a small omental nodule of partially necrotic and calcified endometrioid-like YST. No tumor was detected in several other biopsy specimens, and a peritoneal lavage was negative for tumor cells. Since there was no evidence of remaining tumor and the serum α-fetoprotein (AFP) level was normal after the second operation, the patient was followed. Serial serum AFP levels remained normal for 4 months. At a second-look laparotomy …

Environmentally driven changes in Baltic salmon oxidative status during marine migration.

2020

The fitness and recruitment of fish stocks can be markedly affected by environmental disturbances including global warming, eutrophication and contamination. Understanding the effects of environmental stressors on salmon physiology during marine residence is of a global concern as marine survival has decreased. We present a unique combination of physiological responses - antioxidant defence and oxidative damage biomarkers, stable isotopes and contaminant exposure biomarkers - measured from adult Atlantic salmon (Salmo salar) collected at the Baltic Sea and studied in relation to environmental variables and fitness estimates. The results demonstrate that feeding populations of salmon display…

The serosa of Manduca sexta (Insecta, Lepidoptera): ontogeny, secretory activity, structural changes, and functional considerations

2001

In Manduca sexta, the blastoderm forms successively and becomes immediately cellularized as the cleavage energids reach the surface of the oocyte. Presumptive serosal cells are large and contain 2 or 4 large polyploid nuclei; presumptive embryonic cells are small and mononuclear. All parts of the blastoderm participate in the uptake and digestion of yolk material. About 10 h post-oviposition, the blastoderm breaks at the amnioserosal fold and the extraembryonic part closes above the germ band and constitutes the serosa (12 h post-oviposition, i.e. 10% development completed). At once, the serosa starts to secrete a cuticle consisting of an epi- and a lamellated endocuticle. Detachment of the…

Kinetics and metabolism of 14C-lindane and 14C-atrazine in early life stages of zebrafish (Brachydanio Rerio)

1990

Abstract Fertilized eggs, yolk sac larvae, and juveniles of zebrafish were exposed to 14C-lindane and 14C-atrazine under static conditions and the uptake was studied for a period of 48 hours. After 24 hours, a number of animals were transferred into pesticide-free running water and the elimination was examined for another 24 hours. The bioconcentration factors (BCFs) as well as the rate constants for uptake and elimination were calculated. Except for the lindane uptake by eggs and the atrazine uptake by juveniles, the steady state was reached within five hours. For all tested developmental stages the bioconcentration factor of lindane distinctly exceeded 100, whereas it was less than 10 in …

Do laboratory exposures represent field exposures? Effects of sediments contaminated by wood industry on yolk-sac fry of rainbow trout (Oncorhynchus …

2015

Purpose. Risk assessment of contaminated sediments is routinely based on laboratory exposures. The purpose of this work was to study if sediments contaminated by the chemical wood industry cause developmental defects in fish fry and how well a laboratory exposure correlates with a field exposure. Materials and methods. Newly hatched yolk-sac fry of rainbow trout (Oncorhynchus mykiss) were exposed in the laboratory and in situ. In the laboratory, the fish were placed in contact with either clean or contaminated sediment in aquaria. In the field, half of the fish were placed in contact with the lake sediment and the other half were similarly caged 2 m above it, to discern the effects of the s…

The ontogeny of the filter apparatus of anuran larvae (Amphibia, Anura)

1991

The pharynx ofBufo calamita, Rana temporaria andBombina variegata larvae (larval Types IV and III) changes considerably during the latter part of embryonic development. The entodermal regions between the visceral pockets flatten inward to form the anlagen of the filter plates. The ectoderm thrusts forward from the area of the persistent epidermal gills overlying the anlagen of the filter plates. The esophagus pushes dorsolaterally into the pharynx to give rise to the ciliary cushions. Comparison with the development ofXenopus laevis (larval Type I) reveals shared characters: (1) the filter plates are overlapped by the sensory layer of the epiderm and (2) the ciliary grooves are, like the ci…

Posters
Early pregnancy
P01First trimester normograms for a wide variety of ultrasound, hemodynamic and serum parameters

2000

Background The aim of the study was to assess prospectively the evolution of multiple clinical parameters throughout the first trimester of pregnancy. Method A transvaginal ultrasound examination and a blood test was weekly performed until the 13th gestational week in a group of healthy volunteers. A total of 25 spontaneously conceived singleton pregnant women with good pregnancy outcome finally completed the study. The evolution of 10 transvaginal ultrasound parameters, 5 Doppler measurements and 6 serum parameters was studied. Results An increasing trend with advancing gestation was evident for the mean gestational sac (MSD) and amniotic sac (AS) diameters, trophoblastic rim, CRL and seru…

F117Hystero-embryoscopic findings in early nonviable pregnancies

2000

Background A high proportion of early pregnancy losses are associated to abnormal embryo development. However, chromosomal analysis of routine curettage samples are of limited value; and histopathological examinations of the embryos are rarely performed in clinical practice. Method A transcervical hystero-embryoscopy was performed prior to the curettage in 31 nonviable first-trimester pregnancies and a control group of 5 early terminations of pregnancy. In the study group, the estimated gestational age according to the ultrasound findings was 6.7 (4–9) menstrual weeks. Direct biopsies of different gestational structures were taken during the endoscopic procedure. Results In nonviable pregna…