Search results for "Yolk Sac"

Multiple Receptors Mediate apoJ-Dependent Clearance of Cellular Debris into Nonprofessional Phagocytes

2001

Phagocytosis of apoptotic, senescent, and dying cells by macrophages is a well characterized process. More recently it has been shown that in addition to macrophages vital neighboring cells in the affected tissue participate in the cellular clearance. While scavenger receptors have been shown to mediate uptake into macrophages, it is poorly understood how cellular debris is internalized by nonprofessional phagocytes. We here analyze the endocytic activity of vital fibroblasts and epithelial cells exposed to cellular debris and membrane remnants. We show a mutual stimulation in the endocytosis of debris and apolipoproteinJ (clusterin) in these cells. Experiments using RAP (receptor-associate…

YOLK SAC DEL TESTICOLO: Raro Caso con Metastasi Gigante Retroperitoneale

1989

The authors restorate a case of primary testis tumor (Yolk Sac Tumor) and giant retroperitoneal metastasis clinically evident as a voluminous abdominal mass (23 cm) and associated virilizing syndrome. the diagnostic and therapeutic procedure performed is described.

Bioconcentration and metabolism of 3,4-dichloroaniline in different life stages of guppy and zebrafish

1993

Abstract Bioconcentration factors (BCF) and metabolism of 3,4-dichloroaniline in different life stages of guppy (Poecilia reticulata Peters ) and zebrafish (Brachydanio rerio Hamilton-Buchanan ) were investigated. The results prove that embryos of zebrafish, four-day-old yolk sac larvae, 17-day-old larvae and adult zebrafish are able to transform the chemical to 3,4-dichloroacetanilide. Bioconcentration factors in these life stages are between 30 and 42, exept yolk sac larvae showing a BCF of 86. 3,4-Dichloroacetanilide was also detected in extracts of newborn and adult guppies, but they are able to form an additional, yet unknown metabolite. The BCF varies from 34 in six-month-old guppies …

Cabut, a C2H2 zinc finger transcription factor, is required during Drosophila dorsal closure downstream of JNK signaling.

2005

AbstractDuring dorsal closure, the lateral epithelia on each side of the embryo migrate dorsally over the amnioserosa and fuse at the dorsal midline. Detailed genetic studies have revealed that many molecules are involved in this epithelial sheet movement, either with a signaling function or as structural or motor components of the process. Here, we report the characterization of cabut (cbt), a new Drosophila gene involved in dorsal closure. cbt is expressed in the yolk sac nuclei and in the lateral epidermis. The Cbt protein contains three C2H2-type zinc fingers and a serine-rich domain, suggesting that it functions as a transcription factor. cbt mutants die as embryos with dorsal closure …

Trisomy 12 and translocation (7;9) in an ovarian immature teratoma.

1989

We report a case of an immature malignant ovarian teratoma with peritoneal implants diagnosed in an 18-year-old woman. The tumor was brought into remission after surgery (three laparotomies) and adjuvant chemotherapy. A residual peritoneal implant showed a mature epithelial and glial configuration. Histologically, the neuroectodermal component was dominant in the original tumor as well as in the metastases, being confirmed by immunohistochemistry and electron microscopy. A stem cell line has been obtained with cell culture, having a germ cell character and a yolk sac configuration. This line possessed a trisomy 12 and a translocation (7;9) similar to other chromosomal abnormalities describe…

Toxicity effects of the organic UV-filter 4-Methylbenzylidene camphor in zebrafish embryos

2019

Abstract Ultraviolet (UV) filters are widely used in personal care products and due to their lipophilicity these chemicals tend to bioaccumulate in the aquatic biota. 4-Methylbenzylidene camphor (4-MBC) is one of the most used UV-filters, and it is commonly detected in freshwater fish tissues. This substance is suspected to be an endocrine disruptor due to its interaction with Hypothalamus-Pituitary-Gonadal (HPG) and HP-Thyroid (HPT)-axis. The main objective of this study was to evaluate the effects of 4-MBC on apical endpoints, biochemical markers and on genes involved in endocrine pathways in Danio rerio. Zebrafish embryos were exposed to 4-MBC (0.083–0.77 mg/l) from 0 to 96 h post-fertil…

Acute hepatotoxicity induced by quetiapine fumarate in larval zebrafish

2016

Specific, concentration-dependent uptake of vitellin by the oocytes ofNereis virens (Annelida, Polychaeta) in vitro

1991

One purpose of this study was the development of methods for radioactive labeling and handling of the yolk protein of Nereis virens, another, the utilization of this tracer in nereid oocyte cultures to describe the kinetics and specificity of yolk protein uptake. Accumulation of labeled yolk protein by growing oocytes is linear over time, specific for yolk protein, and dependent on tracer concentration in the medium. Incorporation of yolk protein follows saturation kinetics which allows us to reproducibly determine the characteristics of this process. The apparent KM of ∼ 1 × 10−8 M indicates the high affinity of the transport system; the Vmax (160–400 pg protein/day × oocyte) reveals that …

Antiphosphatidylserine Antibodies Affect Rat Yolk Sacs in Culture: a Mechanism for Fetal Loss in Antiphospholipid Syndrome

2004

PROBLEM: A variety of reproductive impairments have been reported in the context of the antiphospholipid syndrome (APS). APS is associated with the presence of antibodies to negatively charged phospholipids that may affect the outcome of pregnancy. METHOD OF STUDY: Rat embryos were cultured within their yolk sacs. The effects of two antiphosphatidylserine monoclonal aPS antibodies (HL5B, RR7F) regarding their influence on growth and apoptotic events of the yolk sacs, as well as on growth and the morphology of the embryos, were studied. RESULTS: Exposure of rat embryos and their yolk sacs to aPS inhibited yolk sac growth. Moreover, increased number of apoptotic events of giant cells in the a…