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PubMed1991

Application of alcohol- or acetone-fixed Schistosoma eggs as an alternative to lyophilized eggs for the circumoval precipitin test.

Antigenicity of Schistosoma mansoni and S. japonicum eggs preserved in ethanol or acetone were assessed in a circumoval precipitin (COP) assay. The egg antigens were found to retain sufficiently their COP reactivity for the diagnosis of both schistosomiasis mansoni and japonica, although their reactivity became lower than that of lyophilized eggs. These alternative preparations for COP tests have advantages, such as keeping eggs directly in fixatives soon after the egg-purification process. Furthermore, evaporation-process may cause eggshell cleavages which facilitate the reaction. The possible usefulness of those eggs in COP assays in local endemic areas is discussed.

Acetone↗
PubMedDate not supplied

Effect of a live reovirus vaccine on reproductive performance of broiler breeder hens and development of viral tenosynovitis in progeny.

A live commercial reovirus vaccine, Enterovax, was administered to adult broiler breeder hens via the drinking water to determine its efficacy in stimulation of circulating antibody. This vaccine was compared with a commercial inactivated reovirus vaccine. Only the inactivated product resulted in increased antibody as measured by a commercial enzyme-linked immunosorbent assay. However, the live reovirus vaccine caused diarrhea in the hens and decreased eggshell quality, fertility, and hatchability. In addition, the live vaccine virus was vertically transmitted from hens to their progeny, resulting in increased embryonic mortality and viral tenosynovitis.

Administration, Oral↗
PubMed1991

Occupational lung disease.

The pneumoconioses, extrinsic allergic alveolitis, lung damage due to irritant gases, fumes, and smoke constitute the occupational lung diseases that affect the lung parenchyma. The pneumoconioses are diseases resulting from the accumulation of dust in the lungs. The ILO has established a standardized system for classification of these pneumoconioses that includes both descriptions of diffuse lung opacities and pleural disease. The most common of the fibrogenic pneumoconioses are silicosis, CWP, and asbestosis. The former two entities are characterized radiographically by the presence of small rounded opacities or nodules in the lung parenchyma. Eggshell calcification may occur in lymph nodes, and eventually the diseases may be complicated by the development of large massive areas of fibrosis in the upper lung zones. Asbestosis, on the other hand, demonstrates small irregular or linear opacities usually confined to the bases of the lungs. It is associated with significant respiratory symptoms and disability. High resolution CT has proved useful in characterizing the parenchymal changes and also in identifying early disease in all of these entities. Berylliosis is a systemic disorder that in its chronic form produces granulomatous disease in the lungs. Radiographically it is characterized by the development of either small rounded or occasionally irregular linear opacities usually confined to the bases. Chemical pneumonitis results from exposure to toxic fumes. The acute reaction may produce diffuse lung injury characterized by air-space disease typical of pulmonary edema. In the chronic form, bronchiolitis obliterans supervenes. This usually is associated with either a normal radiograph or evidence of hyperinflation. Finally, hypersensitivity pneumonitis or extrinsic allergic alveolitis is a response of the lung to inhalation of antigens that may be present in the workplace. Either acute, subacute, or chronic disease may result. In the chronic form, a diffuse reticulonodular pattern with or without associated lymphadenopathy is characteristic.

Alveolitis, Extrinsic Allergic↗
PubMed1991

A model system and technique to study the effects of ultrasound irradiation on embryonic development.

To study the effects of ultrasound on development it is important to have a system which provides reliable results. We have designed a system which allows for reproducible irradiations of chick embryos in ovo. The irradiation system includes a heated sonation tank with ultrasound absorbers and a PC/AT computer-based data acquisition system for on-line monitoring of irradiations. The ultrasound detection microprobe and irradiation transducers were calibrated against an NBS traceable balance meter. An acoustic spacer was utilized to provide a more uniform profile of the irradiation beam. At the position of the embryo the ultrasound field geometry was determined. To maintain the chick embryo in its natural physiological state while minimizing ultrasonic reflections and standing-wave generation, two diametrically opposed windows were made in the eggshell along the ultrasound pathway and covered with polyethylene membranes. Using this irradiation system at intensity levels as high as 1.1 W/cm2 (spatial average, temporal average) for 10 min, the temperature rise is minimal.

Animals↗
PubMed1990

Biliary calcium and gallstone formation.

The purpose of this paper is to present a brief overview of the current status of the field of biliary calcium and the role of calcium in the formation and maturation of gallstones. The study of free Ca+(+) ions in bile by electrochemical potentiometric measurements using Ca+(+)-selective ion-exchange electrodes is a relatively new field, but much progress has been made in the past few years. Using this powerful analytical tool, new concepts and findings have arisen in almost every aspect of biliary calcium. Although the current symposium is targeted primarily toward cholesterol gallstones, there are several areas in which understanding of biliary calcium may significantly contribute to a better understanding of the pathogenesis of cholesterol, as well as "pigment" (calcium salt), gallstones. Five broad areas are considered in relation to biliary calcium: (a) physiology (calcium entry into bile), (b) biophysics (the regulation of biliary free [Ca+(+)] as related to Gibbs-Donnan equilibria, (c) physical chemistry (the physicochemical state of calcium in bile, (d) thermodynamics (calcium solubility in bile), and (e) kinetics (pronucleating and antinucleating factors and metastable states). With more specific reference to cholesterol stones, consideration is also made of (a) the calcium salt "seed" hypothesis in cholesterol stone pathogenesis; (b) the interactions of Ca+(+) with phospholipid-cholesterol vesicles, with consideration of possible structural requirements and (c) thermodynamic and kinetic factors as related to peripheral or "eggshell" calcification of existing cholesterol stones.

Animals↗
PubMed1990

Unconjugated bilirubin and cholesterol gallstone formation.

Cholesterol gallstones usually have small amounts of pigment at their centers and often have diffuse pigmentation or pigmented layers alternating with cholesterol layers and/or pigmented rims associated with calcium carbonate (eggshell calcification). The pigments are primarily monomeric calcium salts of unconjugated bilirubin anions and/or an insoluble, black, network polymer of tetrapyrroles. Bilirubin presumably can precipitate only if bile is supersaturated with calcium bilirubinates. Among various in vitro model systems, the aqueous solubilities and pK'a values for unconjugated bilirubin differ greatly. It is therefore not known whether normal bile is saturated with unconjugated bilirubin. However, all systems indicate that unconjugated bilirubin is solubilized by binding to bile salt monomers and oligomers, as well as micelles; marked metastable supersaturation of unconjugated bilirubin can occur in the presence of bile salt micelles, and both pK'a values of unconjugated bilirubin are greater than 6.0, probably because of internal hydrogen-bonding of the--COOH groups. Lecithin decreases equilibrium solubilization of unconjugated bilirubin crystals but enhances metastable supersaturation of unconjugated bilirubin. Calcium ions form insoluble salts with unconjugated bilirubin monoanions and dianions but soluble complexes with bilirubin conjugates. The solubility products of the calcium bilirubinate salts suggest that normal hepatic bile is not saturated with CaB or Ca(HB)2 but that gallbladder bile may be supersaturated with Ca(HB)2.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Pathogenesis of Salmonella enteritidis infection in laying chickens. I. Studies on egg transmission, clinical signs, fecal shedding, and serologic responses.

Laying hens were inoculated orally, intracloacally (IC), or intravenously (IV) with Salmonella enteritidis phage type 8 isolates from a human (E700-87) eggs (Y-8P2), or the ovary of a hen (27A). Oral or IV inoculation of 2 x 10(8) to 4 x 10(8) colony-forming units (CFU) of E700-87 caused depression, anorexia, reduced egg production, diarrhea, and some mortality. Lower doses resulted in milder clinical signs. S. enteritidis was cultured from the shells of a few eggs but not from egg contents. Fecal shedding persisted for up to 6 weeks in some birds. Isolate Y-8P2 (10(6) CFU) also caused anorexia, diarrhea, and a drop in egg production. Hens inoculated orally or IC were less severely affected than those inoculated IV. Fecal shedding was intermittent and lasted up to 18 days. Eggshells from the IC-inoculated birds had the highest rate of contamination, and S. enteritidis was isolated from the albumen of 11 and yolk of three of 726 eggs. Oral inoculation of 10(6) CFU of isolate 27A resulted in a bacteremic infection with seeding of the liver, spleen, peritoneum, ovule, and oviduct. However, the birds remained clinically normal with normal egg production. S. enteritidis was cultured from the yolk and albumen of a small number of eggs until 11 days postinfection. Antigen prepared from S. enteritidis detected antibody in more sera than did commercially available S. pullorum antigen in agglutination tests.

Animals↗
PubMed1986

Demonstration of anti-cuticular antibodies by immuno-electron microscopy in sera of mice immunized with cuticular extracts and isolated cuticles of adult Dipetalonema viteae (Filarioidea).

The immunogold technique was used for the ultrastructural localization of antibody-binding sites on thin sections of Lowicryl K4M embedded adult females, infective larvae and pieces of adult cuticles of Dipetalonema viteae insoluble in SDS-2-ME. The antisera used were either produced against SDS-2-ME extracts of cuticles or the insoluble pellet after SDS-2-ME extraction. With both types of antisera a labelling of epitopes on fibers was achieved in intact cuticles. In isolated cuticles the corresponding structures were absent. The same sera crossreacted with the larval and microfilarial cuticle as well as with somatic structures of all three stages. The only serum against isolated cuticle, which did not recognize cuticle fibers also did not crossreact with somatic structures. The recognition of the electron dense cortical layer insoluble in SDS-2-ME depended on the number of immunizations. A labelling of the filarial surface was never achieved. A dense labelling of the apical membrane enfoldings of the hypodermis pointed to an involvement in the synthesis of the nematode cuticle. The rough endoplasmic reticulum in the apex of the epithelial cells of the uterus, the content of the nutrient channels, and the substance between eggshell and microfilariae crossreacted with most of the antisera. This led to the conclusion that these substances are partly produced by the uterus epithelium.

Animals↗
PubMed1989

[Uncommon calcification of a pheochromocytoma: a case report].

A 62-year-old man with a 2-year history of hypertension was referred for evaluation of severe back pain, but his blood pressure was normal during his hospital stay. Plain radiography and excretory urography demonstrated central and eggshell-like calcification in the left suprarenal area. Computed tomographic scan confirmed similar shapes for the left adrenal calcifications. Laboratory examination revealed that the urinary normetanephrine was elevated. Left adrenal venography showed that the mass was in the middle to lower portion of the left adrenal gland. The most likely diagnosis was, calcified pheochromocytoma. The left adrenal tumor was removed surgically through a thoracolumbar incision on September 19, 1985. The blood pressure rose to 186/102 mmHg at the time of tumor manipulation. The tumor was a markedly hard mass, which was 3.5 x 3.5 x 3.0 cm and weighed 20 g. The histopathologic diagnosis was calcified pheochromocytoma. The patient remained symptomless after the operation.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Adapting fixed prosthodontics principles to screw-retained restorations.

Implant restorations may be visualized clinically using a provisional fixed partial denture and in the laboratory with a fully contoured waxing on the master cast. The benefits of eggshell restorations for provisional restorations are as valid in implant prostheses as in conventional restorations. A technique is presented using the plastic laboratory sleeves to provide reliable anchorage as well as protection and preservation of the abutments. A fully contoured waxing on the master cast predictably determines the most appropriate design for screw-retained restorations. When unfavorable implant placement would create compromised morphology, a retrievable auxiliary substructure is indicated.

Dental Abutments↗
PubMed1987

Lectin binding to the developing forms of Onchocerca gutturosa microfilariae.

Uterine and skin derived forms of microfilariae (mf) and earlier developing stages of the cattle filarial nematode Onchocerca gutturosa were examined for the lectin binding properties of their external surfaces (ie. egg shell and microfilarial cuticle). Both the uterine and skin derived forms of mf failed to bind any of the lectins tested. Incubation in known microfilaricides did not promote any binding of lectins to these parasites. Peanut agglutinin (PNA) was the only lectin found to bind specifically to earlier developing stages (i.e. the shells of freshly obtained eggs). Diethylcarbamazine (DEC) did not alter the binding pattern from that observed in untreated eggs. Ivermectin eliminated PNA binding but increased Ricinus communis lectin (RCA-1) positivity. Trypsin, collagenase and protease enzymes all affected the binding; chitinase however did not have any effect. These results support the concept that the eggshells of filariae can interact with the host defence responses.

Animals↗
PubMedDate not supplied

Computed tomography of anterior mediastinal tumors. Differentiation between thymoma and germ cell tumor.

Computed tomographic (CT) features in 10 patients with germ cell tumor of the mediastinum and 15 with thymoma were compared with surgically resected specimens. The CT findings of the internal structure of tumors were the most important factor for specific diagnosis. Germ cell tumors showed a round mass without distinct lobulation, frequently with calcification appearing as a globular shape, and especially in benign tumors as an arched shape along the wall. Homogeneous low density masses (near-water) with a thick wall were benign and non-homogeneous density masses (a mixture of near-water and soft tissue) were malignant. Thymoma usually showed a solid mass with lobulation and sometimes had an eggshell type of calcification in the tumor. Therefore, CT is of importance in the diagnosis of anterior mediastinal masses.

Calcinosis↗
PubMed1987

Pores and gas exchange of avian eggs: a review.

Pores of the avian eggshell provide the only communicating channels for the exchange of molecules between the developing embryo and the external environment. These trumpet-shaped ducts are microscopic. Their number and effective pore radius increase with egg mass from ca. 300 and 3 microns in 1 gm eggs to about 30,000 and 13 microns, respectively, in 500 gm eggs (Ar and Rahn, Respir. Physiol. 61:1-20, 1985). The total volume of all the gases that diffuse through these pores is large. For example, up to the time when internal pipping takes place, when pulmonary ventilation is initiated, about 20 liters (O2 + CO2 + water vapor) have passed through 10,000 pores of an 80 gm egg. The rules governing this exchange of gases are best described by Fick's first law rather than by Stefan's law, which describes the transfer of gases across stomata of plants. Data are presented for those species for which the water vapor conductance, the oxygen flux at the preinternal pipping stage, the rate of incubation water loss, and the number of pores in the egg have been established. These conductances and flux rates are directly proportional to the number of pores. These relationships suggest that, in spite of differences in egg mass and incubation time, in most birds the average conductance of individual pores is similar, namely, 1.5 microgram (d X torr)-1 and that the average O2 and water vapor flux per pore are 60 and 54 microliters X d-1, respectively. These values are similar to the estimates previously presented (Ar and Rahn, '85).

Animals↗
PubMed1987

Endocytosis in the embryonic chick chorionic epithelium.

The chorionic epithelium of the developing chick embryo consists of two major cell types, villus cavity (VC) and sinus-covering (SC) cells. Ultrastructurally, VC cells contain apical microvilli with numerous underlying vesicles, whereas SC cells possess thin cytoplasmic processes (containing occasional vesicles) overlying adjacent blood sinuses. This study was performed to determine whether vesicles observed in VC and SC cells are endocytic in nature and whether endocytosis is limited to either VC or SC cells. Exposure of air space chorionic epithelium in ovo to microperoxidase (MRP-11) resulted in endocytic uptake of marker by the thin cytoplasmic processes of 70% of SC cells. Vesicles containing MRP-11 reaction product were also observed in approximately 20% of VC cells. Exposure of the chorionic epithelium of shell-less cultured embryos to horseradish peroxidase (HRP) resulted in endocytic uptake of HRP in approximately 80% of SC cells and in 33% of VC cells. Thus, VC and SC cells demonstrate endocytic activity both in ovo and in shell-less culture. In ovo, endocytosis may be involved in the recovery of water and/or ions from the eggshell or shell membranes.

Animals↗
PubMed1987

Shell conductance, daily water loss, and water content of Andean gull and Puna ibis eggs.

Characteristics of Andean gull (Larus serranus) and Puna ibis (Plegadis ridgwayi) eggs laid at 4,400 m in the Peruvian Andes were studied to determine how the conflicting requirements of maximizing O2 availability to the embryo while minimizing excessive losses of water vapor and CO2 have been met by avian populations breeding at high altitudes. Egg masses, linear dimensions, and surface areas of these montane eggs were similar to those of Heermann's gull (Larus heermanni) and glossy ibises (Plegadis falcinellus), but conductance to water vapor (GH2O, standardized to 760 torr) of Andean gull and Puna ibis eggs averaged 74.5% and 68.4%, respectively, of lowland values. The difference in GH2O of Andean gull eggs was caused primarily by a reduction in the number of pores per egg; both an increased shell thickness and a smaller number of pores reduced GH2O of Puna ibis eggs. Since the reduction of GH2O of montane eggs did not fully compensate for the change in barometric pressure (59% of sea level) and the increase in gaseous diffusion coefficients at 4,400 m, the "effective" conductance of the eggs at that altitude was greater than at sea level. Therefore, the eggs lost substantially more water during incubation than did lowland eggs. The modifications in eggshell characteristics of montane eggs may have resulted from selection to increase O2 availability to the embryo.

Altitude↗
PubMed1987

Effect of two gas mixtures on growth of the domestic fowl embryo from days 14 through 17 of incubation.

Eggs weighing 62.5 +/- 0.5 gm when fresh were incubated in air in a forced-draft incubator for 13 days during which time their shell conductance to water vapor (GH2O) was determined. Eggs whose shells represented the entire range of GH2O values present in the population were then incubated for a further 4 days in either air or an experimental gas mixture. Embryo dry weights were determined after a total of 408 hr of incubation to assess the affect of the experimental gas mixture on embryonic development. Embryo growth was found to be stimulated for all eggshell conductances by 4 days incubation in a 50% oxygen/50% nitrogen mixture. This suggests that the decrease in oxygen within the egg that occurs during development normally limits embryonic growth. Growth of the embryo was unaffected by 4 days incubation in a mixture of 17% oxygen/83% helium. This mixture reduced the carbon dioxide tension in the airspace but did not affect the oxygen tension relative to eggs incubated in air. It is suggested, therefore, that the carbon dioxide that builds up within eggs during incubation does not limit embryo growth.

Animals↗
PubMed1985

A reliable, efficient, microinjection apparatus and methodology for the in vivo exposure of rainbow trout and salmon embryos to chemical carcinogens.

A modular apparatus and technique for the injection of salmonid fish embryos with chemical carcinogens are described. A key feature of the methodology is the relative ease of routine through-the-eggshell injection, into the yolk sac of living salmonid fish embryos, inside the "eyed-stage" egg. The procedure is sufficiently rapid that 2 persons working as a team can give injections to 200 embryos per hour. The injection per se induces low mortality, i.e., optimal net survival rates (controls given an injection of dimethyl sulfoxide vs. those not given an injection) in the range of 70-90%. Because only small amounts of chemical are handled in relatively dilute form, the exposure method poses low risks to both the experimentalist and the environment. Preliminary results in a test of 4 carcinogens that differed widely in their structures and requirements for metabolic activation indicated that hepatocellular neoplasms were induced in rainbow trout (Salmo gairdneri) in response to 100 ng aflatoxin B1 (CAS: 1162-65-8)/egg, 1 microgram N-methyl-N'-nitro-N-nitrosoguanidine (CAS: 70-25-7)/egg, and 10 micrograms benzo[a]pyrene (CAS: 50-32-8)/egg. Nine months after exposure, liver neoplasms were observed in 25, 21, and 9%, respectively, of the rainbow trout, but no neoplasms were observed in rainbow trout exposed to 100 micrograms dimethylnitrosamine (CAS: 62-75-9)/egg. Liver neoplasms were also induced in 17% of coho salmon (Oncorhynchus kisutch) given an injection as embryos of 90 ng aflatoxin B1/egg or 5 micrograms N-methyl-N'-nitro-N-nitrosoguanidine/egg.

Aflatoxin B1↗
PubMed1979

Computed tomography of a carotid body tumor.

A patient with a carotid body tumor was evaluated by computed tomography. The tumor demonstrated an enhanced rim and a central lower density. This corresponds to the "eggshell" appearance described angiographically in carotid body tumors.

Adult↗