Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Egg Shell”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,081 records · Page 60Linked to original sources
PubMed1984

Effects of vitamin D3 deficiency on estradiol-17 beta metabolism in the laying hen.

Evidence is presented that in vitamin D deficiency there are aberrations of estrogen metabolism in the laying hen. Five White Leghorn hens, 35 weeks of age, all laying soft shelled eggs as a result of complete withdrawal of supplemental vitamin D3 (D3) from the diet, were found to have a 3-fold higher molar ratio of plasma estradiol-17 beta-3-sulfate (E2 beta-3S) to estradiol-17 beta (E2 beta) compared to five control laying hens fed a D3-supplemented diet. A time course tracer study with [3H]E2 beta administered iv revealed an abnormally high accumulation of [3H]E2 beta-3S in plasma, and concomitantly, a markedly reduced formation of [3H]estradiol-17 alpha-3-sulfate [( 3H]E2 alpha-3S) compared with the control hens. This observation suggests a defect in the conversion of [3H]E2 beta-3S to [3H]E1S, previously shown to be a major pathway for E2 beta metabolism (E2 beta E2 beta-3S in equilibrium E1S E2 alpha-3S). As a result, the MCR of [3H]E2 beta from plasma of the D3-deficient hens was about 15% below normal. The calculated production rate of E2 beta was reduced even more, by 60%. However, the reduced production rate could have been related to the lengthening of the ovulatory cycle due to vitamin D deficiency. It is concluded that vitamin D deficiency affects the biosynthesis and catabolism of E2 beta in the laying hen.

Animals↗
PubMed1997

Post-transcriptional regulation of gurken by encore is required for axis determination in Drosophila.

Establishment of anterior-posterior and dorsal-ventral polarity within the Drosophila egg chamber requires signaling between the germline and the somatic cells of the ovary. The gene gurken (grk) encodes a TGFalpha-like protein that is localized within the developing oocyte and is thought to locally activate torpedo/Egfr (top/Egfr), the Drosophila homolog of the EGF receptor, which is expressed throughout the follicular epithelium surrounding the oocyte. grk-Egfr signaling is required early in oogenesis for specification of posterior follicle cell fate and later in oogenesis for dorsal follicle cell fate determination, thus establishing the axes of the egg shell and embryo. Previous studies have shown that these patterning processes are highly sensitive to changes in the levels and localization of grk mRNA. Here we show that post-transcriptional regulation of Grk protein levels is required for correct pattern formation. encore (enc), a gene that functions in the regulation of germline mitosis and maintenance of oocyte identity, is also required for the accumulation of Grk protein during oogenesis. We present evidence that enc regulates Grk post-transcriptionally to ensure adequate levels of signaling for establishment of the anterior-posterior and dorsal-ventral axes.

Animals↗
PubMed1998

The Dorsal-related immunity factor (Dif) can define the dorsal-ventral axis of polarity in the Drosophila embryo.

In Drosophila embryos, dorsal-ventral polarity is defined by a signal transduction pathway that regulates nuclear import of the Dorsal protein. Dorsal protein's ability to act as a transcriptional activator of some zygotic genes and a repressor of others defines structure along the dorsal-ventral axis. Dorsal is a member of a group of proteins, the Rel-homologous proteins, whose activity is regulated at the level of nuclear localization. Dif, a more recently identified Drosophila Rel-homologue, has been proposed to act as a mediator of the immune response in Drosophila. In an effort to understand the function and regulation of Rel-homologous proteins in Drosophila, we have expressed Dif protein in Drosophila embryos derived from dorsal mutant mothers. We found that the Dif protein was capable of restoring embryonic dorsal-ventral pattern elements and was able to define polarity correctly with respect to the orientation of the egg shell. This, together with the observation that the ability of Dif to restore a dorsal-ventral axis depended on the signal transduction pathway that normally regulates Dorsal, suggests that Dif protein formed a nuclear concentration gradient similar to that seen for Dorsal. By studying the expression of Dorsal target genes we found that Dif could activate the zygotic genes that Dorsal activates and repress the genes repressed by Dorsal. Differences in the expression of these target genes, as well as the results from interaction studies carried out in yeast, suggest that Dif is not capable of synergizing with the basic helix-loop-helix transcription factors with which Dorsal normally interacts, and thereby lacks an important component of Dorsal-mediated pattern formation.

Animals↗
PubMed2001

Sequential computed tomography images demonstrating characteristic changes in fibrous dysplasia.

Images of fibrous dysplasia (FD) on computed tomography (CT) or magnetic resonance imaging (MRI) vary depending on the relative proportions of the fibrous and osseous components. Based on analysis of the literature, Camilleri suggested that structural changes revealed by conventional radiography may be indicative of the progression of FD. Here we describe the case of a boy who presented at 12 years of age with monostotic FD located in the right maxilla. The lesion first appeared as a lamellar, "onion peel"-like structure on CT; then over the course of the next five years, the structure became what has been termed an "egg-shell lesion", before eventually assuming the form of a "ground-glass lesion".

Adult↗
PubMed2005

Thermostability of refolded ovalbumin and S-ovalbumin.

Ovalbumin, a member of the serpin superfamily, is transformed into a thermostabilized form, S-ovalbumin, during storage of shell eggs or by an alkaline treatment of the isolated protein (DeltaT(m)=8 degrees C). As structural characteristics of S-ovalbumin, three serine residues (Ser164, Ser236 and Ser320) take the D-amino acid residue configuration, while the conformational change from non-thermostabilized native ovalbumin is very small. To assess the role of the structural characteristics on protein thermostabilization, ovalbumin and S-ovalbumin were denatured to eliminate the conformational modulation effects and then refolded. The denatured ovalbumin and S-ovalbumin were correctly refolded into the original non-denatured forms with the corresponding differential thermostability. There was essentially no difference in the disulfide structures of the native and refolded forms of ovalbumin and S-ovalbumin. These data are consistent with the view that the configuration inversion, which is the only chemical modification directly detected in S-ovalbumin so far, plays a central role in ovalbumin thermostabilization. The rate of refolding of S-ovalbumin was greater than that of ovalbumin, indicating the participation, at least in part, of an increased folding rate for thermodynamic stabilization.

Hot Temperature↗
PubMed1985

Fetal PCB syndrome: clinical features, intrauterine growth retardation and possible alteration in calcium metabolism.

Pregnant mothers with yusho in Fukuoka, Nagasaki and Kochi Prefectures delivered babies with a peculiar clinical manifestation which will be called fetal PCB syndrome (FPS). The birth rate incidences were 3.6% (Fukuoka Prefecture), 4% (Nagasaki Prefecture), 2.9% (Kochi Prefecture) and 3.9% (total). The manifestations consisted of dark brown pigmentation of the skin and the mucous membrane, gingival hyperplasia, exophthalmic edematous eye, dentition at birth, abnormal calcification of the skull as demonstrated by X-ray, rocker bottom heel and high incidence of light for date (low birth weight) babies. We suggest that there may be a possible alteration in calcium metabolism in these babies, related to the fragile egg shells observed in PCB-contaminated birds and to the female hormone-enhancing effect of PCB. The high incidence of low birth weight among these newborns and two other similar studies indicated that PCBs suppress fetal growth.

Calcium↗
PubMed2006

Endocrine disrupting contaminants--beyond the dogma.

Descriptions of endocrine disruption have largely been associated with wildlife and driven by observations documenting estrogenic, androgenic, antiandrogenic, and antithyroid actions. These actions, in response to exposure to ecologically relevant concentrations of various environmental contaminants, have now been established in numerous vertebrate species. However, many potential mechanisms and endocrine actions have not been studied. For example, the DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane] metabolite, p,p -DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene] is known to disrupt prostaglandin synthesis in the uterus of birds, providing part of the explanation for DDT-induced egg shell thinning. Few studies have examined prostaglandin synthesis as a target for endocrine disruption, yet these hormones are active in reproduction, immune responses, and cardiovascular physiology. Future studies must broaden the basic science approach to endocrine disruption, thereby expanding the mechanisms and endocrine end points examined. This goal should be accomplished even if the primary influence and funding continue to emphasize a narrower approach based on regulatory needs. Without this broader approach, research into endocrine disruption will become dominated by a narrow dogma, focusing on a few end points and mechanisms.

Animals↗
PubMed1991

Morphological observation of Toxocara vitulorum found in Japanese calves.

Between 1982 and 1988, ascarid nematodes were found in the feces of Japanese calves in Kyushu and Okinawa districts. Seven males and 21 females of the ascarids were observed morphologically for identification of species. Male and female ascarids were 15.64 (14.0-18.0) cm and 25.75 (16.5-34.0) cm in average length, respectively. Eggs were 81.6 microns and 71.8 microns in large and small diameters, respectively. The body of ascarids was translucent and soft. The boundary between the enlabium and prelabium of lip was clearly visible and the esophageal ventriculus was also observed. The vulva was situated at a distance of about 1/7 approximately 1/9 of body length from the anterior end of body. The surface of egg shell was relatively smooth, without rugose albuminous coat. These morphological features coincided with those of Toxocara vitulorum.

Animals↗
PubMed1995

Invasion and viability of Campylobacter jejuni in experimentally contaminated Japanese quails' eggs.

In Japanese quail eggs experimentally immersed in a suspension of Campylobacter jejuni from human patients (Y6817, Y6878), strain Y6817 was recovered from 15 (18.8%) eggs among 80 between 0.5 hr and 72 hr after immersion. Invasion of the eggs by strain Y6878 was also seen in 10 (12.5%) of 80 eggs between 0.5 hr and 24 hr after immersion. When egg yolk was inoculated with both strains and held at 4 degrees C, the organisms were detectable for a longer time than the ones kept at 20 degrees C. On the other hand, when albumen was inoculated with both strains, the organisms died within 96 hr at 4 degrees C and within 24 hr at 20 degrees C.

Animals↗
PubMed2006

Fluorescent reporter methods.

The identification and cloning of the green fluorescent protein (GFP) from jellyfish marks the beginning of a new era of fluorescent reporters. In Caenorhabditis elegans, genetically encoded markers like the fluorescent proteins of the GFP family became the reporter of choice for gene expression studies and protein localization. The small size and transparency of the worm allows the visualization of in vivo dynamics, which increases the number of potential applications for fluorescent reporters tremendously. In combination with subcellular tags, GFP can be used to label subcellular structures like synapses allowing novel approaches to study developmental processes like synapse formation. Other fluorescent labels like small organic dyes, which are in widespread use in cell culture systems, are rarely used in C. elegans owing to difficulties in applying these labels through the impenetrable cuticle or eggshell of the animal. A notable exception is the use of lipophilic dyes, which are taken up by certain sensory neurons in the intact animal and can be introduced into the embryo after puncturing of the egg shell. This chapter covers the use of fluorescent dyes and fluorescent proteins in C. elegans. Emphasis is placed on microscopic techniques including wide field and confocal microscopy as well as time-lapse recordings. The use of fluorescent proteins as transgenic markers and image processing of fluorescence images are briefly discussed.

Animals↗
PubMed1987

Changes in oviducal vascularity during the reproductive cycle of three oviparous lizards (Eumeces obsoletus, Sceloporus undulatus and Crotaphytus collaris).

Histologically derived estimates and ink suspension vascular casts were used to examine oviducal vascular changes. Vascularity peaked during gravidity and was correlated with maximal plasma progesterone concentrations. The vascular increase in the oviducal tissue was attributed exclusively to increased capillary densities. The greatest change occurred in the anterior uterus where incubation and egg shell secretion occur. Similar patterns of change in vascularity occurred in the infundibulum, although not as extreme as that seen in the anterior uterus, whereas no significant alterations were noted in the posterior uterus. These modifications mimic the pattern of vascular change occurring in viviparous lizards during simple placentation. We suggest that major changes in uterine vascularity may not be required for the evolution of simple chorioallantoic placentae in lizards.

Animals↗
PubMed1998

[Food borne disease outbreaks caused by Salmonella enteritidis].

OBJECTIVE: It is to describe outbreaks of salmonellosis reported from July 1993 through June 1997 in the Northwest region of S. Paulo State, Brazil, one of the areas where several foodborne outbreaks of salmonellosis have been recently detected. METHOD: Data of 19 epidemiological investigations were analysed; 87 stool specimens and 38 food samples (including 12 of shell eggs) were processed for microbiological analysis. Salmonella strains were identified by serotyping, phagetyping and antimicrobial susceptibility testing. RESULTS: There were 906 ill persons including 295 hospitalized patients. Phage type 4 (PT 4) Salmonella Enteritidis strains were isolated from 80.5% of stool samples, from all food samples and from 41.7% of eggs. Of the outbreaks, 95.7% were associated with the consumption of food containing raw or undercooked eggs. All strains were susceptible to the 13 antimicrobials, except the strains from the nosocomial outbreak. CONCLUSIONS: The results obtained show the need for the implementation of control measures regarding egg and storage, as well as for guidance to the public as to the risks involved in the consumption of inadequately prepared eggs.

Aged↗
PubMedDate not supplied

[Natural infection of Speothos venaticus (Carnivora: Canidae) by adult stages of Lagochilascaris sp].

An adult male Speothos venaticus Lund (bush dog) was found killed on a rural road in the Northeast of Bolívar State, in a locality where a patient with lagochilascariasis has lived for the past 16 years. The animal was frozen for 1 month, and after removal of the head and skin, was autopsied. Two adult gravid females of Lagochilascaris sp. were found in the trachea. Certain morphological characteristics of the soft parts differed from the description given for Lagochilascaris minor Leiper, 1909; however, stable characters, such as the form of the interlabials, the location of the vulva, and particularly the size and number of depressions of the egg shell appear to indicate that the worms are of the above mentioned species. Unfortunately, no males were found for study of the spicules and ejaculatory duct. In histological sections of the larynx and the trachea from the deep tissues, parts of degenerated worms were found, with characteristics attributable to Lagochilascaris sp.

Animals↗
PubMedDate not supplied

Changing patterns of Salmonella serovars: increase of Salmonella enteritidis in São Paulo, Brazil.

Serovars of a total of 5,490 Salmonella strains isolated during the period of 1991-95, from human infections (2,254 strains) and from non-human materials (3,236 strains) were evaluated. In the studied period, 81 different serovars were determined among human isolates. Salmonella Enteritidis corresponded to 1.2% in 1991, 2% in 1992, 10.1% in 1993, 43.3% in 1994, and 64.9% in 1995 of all isolates. A significant rise on the isolation of this serovar was seen since 1993 linked to food poisoning outbreaks. It is reported also an increase on the isolation of S. Enteritidis from blood cultures, associated mainly with patients with immunodeficiency syndrome. S. Enteritidis was prevalent among one hundred and thirty different serovars isolated from non-human sources. Increasing number of isolation of this serovar was seen from shell eggs, breeding flocks and from environmental samples. It is also reported a contamination of commercial feed stuffs by S. Enteritidis which represents a major concern for Brazilian poultry industry.

Animals↗
PubMed1989

Regulation of gene expression in the Schistosoma mansoni female.

The maturation of females of S. mansoni is a process which depends on the presence of male parasites. Preliminary results indicated that the males may secret hormones, possibly steroid or steroid-like compounds, which regulate the expression of genes directly connected to events pertaining to oogenesis. Because the eggs are important agents in the pathology of schistosomiasis, it is of interest to elucidate the biochemical events associated to this developmental stage. The present work describes the efforts to characterize proteins which regulate the expression of a gene encoding a major protein precursor of egg shells and which is only transcribed by adult females. It is hoped that the receptor for the male hormone will be detected among these regulatory proteins.

Animals↗
PubMed1998

[Alternative foods: a critical analysis of a proposal for nutritional intervention]

The nationwide use of a 'Multimixture' a formula based on alternative foods such as rice and/or wheat bran, sesame and squash seeds, cassava, beet and carrot leaves, several indigenous leafy vegetables, and ground egg shells has been proposed by the National Institute of Food and Nutrition (INAN) as an official solution to fight hunger among poor Brazilians. The fragile nutritional state of the target population may make technical or ethical questions appear purely academic, yet nutritional, toxicological, and practical feasibility considerations appear to warrant a revision of the INAN proposal. While the Multimixture approach may prove valid as a temporary solution in cases of extreme poverty, it is not universally applicable for the intended use, failing to take into account the age and nutritional status of the subjects or duration of the intervention.

Journal Article↗
PubMed2005

[Comparison of imaging methods for diagnosis of renal tumors and their calcifications].

BACKGROUND: To establish the best methodology for diagnosis and management of patients with solid and complex renal masses by comparing the costs and benefits of different imaging methods and to improve differential diagnosis of these benign and malignant lesions, particularly by investigating tumour calcifications. METHODS: We performed a prospective study on 31 patients with solid or complex masses by submitting them to Abdominal Ultrasonography (US), Doppler Ultrasonography of the renal mass (US Dop), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI). RESULTS: We found 28 patients with malignant and three with benign masses. Of the 28 malignant, 17 showed calcifications at CT; 16 central and one was of the pure peripheral curvilinear type (egg shell). Excretory Urography (IVP) had a significantly lower detection rate for central calcifications than both US and CT. Benign and malignant masses appeared as described in literature, with US, CT and MRI showing high sensitivity and specificity in renal tumor diagnosis. The exception was US Dop where we obtained lower sensitivity for the characterization of malignant tumor flow. CONCLUSIONS: In this series we were surprised to find that CT revealed central calcifications in 51.6% of patients, all with malignant lesions, while, literature reports a frequency of calcification in renal cell carcinoma between 8 and 22%, in studies using abdominal films and EU (IVP). This finding is of great importance when we consider that these calcifications occur particularly in malignant neoplasms. As a result of comparing these different imaging methods we have developed a better methodology for renal tumor investigation.

Adult↗