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At least 721 records · Page 40Linked to original sources
PubMed1985

Biological activity of the three mono-beta-D-glucopyranosides of 1,25-dihydroxycholecalciferol.

The biological activity of the three mono-beta-D-glucopyranosides (mono-glucosides) of 1,25-dihydroxycholecalciferol [1,25(OH)2D3] synthesized chemically has been studied in chicks and Japanese quails. While the 1- and the 3-glucoside showed no or only little effect on serum calcium, bone weight, calcium binding protein (CaBP) or calcium deposition in the egg shell, the 25-glucoside was found to be more than half as active as the aglycone 1,25(OH)2D3. The bioactivity of this glucoside parallels a higher binding constant to the intestinal 1,25(OH)2D3 receptor compared to those of the two other glucosides.

Animals↗
PubMed1989

Adenosine triphosphatase in the uterus and duodenum of chicken hens during eggshell formation.

Plasma calcium concentration and uterine and duodenal adenosine triphosphatase (ATPase) activities were determined during shell formation for high (H) and low (L) shell strength lines of hens selected from the last of four consecutive generations. The H and L lines were divided into three groups according to shell formation at 0, 15, and 22 h following oviposition. Plasma total calcium was determined from blood samples collected from the common carotid artery. Activity of ATPase was determined in uterine and duodenal mucosa. Shell strength, shell weight, percentage of shell per egg and shell thickness of the H line hens significantly exceeded those of the L line. During shell formation, no significant fluctuation in plasma calcium levels was observed within a line, but overall mean plasma calcium concentrations were higher in the H line than L line. Uterine ATPase activity increased with time after oviposition in both lines, with that of the H line being greater. Duodenal ATPase activity of H line hens remained fairly constant throughout the period, but this value showed fluctuations in the L line hens. It thus appears that laying hens with high and low shell strength may vary in their ability to use calcium for shell formation.

Animals↗
PubMed1984

The resorption of biological and non-biological substrates by cultured avian and mammalian osteoclasts.

Mammalian and avian osteoclasts were isolated mechanically from long bones, seeded on to either untreated, unmineralized, anorganic or surface-demineralized mammalian dental tissues, and cultured for 1-6 h or up to 9 days in medium with added serum (10% heat-inactivated FCS). All substrates showed Howship's resorption lacunae which varied in detail with the composition and structural organization of the tissue. There was no species or substrate specificity. Osteoclasts also adhered, spread, migrated and resorbed in the absence of serum. In addition, osteoclasts resorbed avian egg shell and mollusc shell containing calcite and aragonite. When given the opportunity, osteoclasts are thus biochemically competent to resorb a much wider range of substrates than they usually do in vivo. Access to the substrate and attraction or deliverance of osteoclast precursors to it must be curtailing factors in in vivo resorption.

Absorption↗
PubMed1996

An outbreak of thiram poisoning on Spanish poultry farms.

Thiram-contaminated poultry feed caused soft egg shells, depressed growth and leg abnormalities in about 1 million birds. Corn previously treated with thiram and colored red was the source of the contamination as detected by gas chromatography and mass spectroscopy examinations. Standardized color-recognition for treated grain products could have avoided this situation and speaks to the international adoption of such standards.

Abnormalities, Drug-Induced↗
PubMed1986

Biological activity of fluorine-substituted 1,25-dihydroxyvitamin D3 in rats, in chicken and in Japanese quails.

The biological activity of two fluorinated analogs of 1,25(OH)2D3 was compared with 1,25(OH)2D3 in various vitamin D assays. The effect of 24,24-F2-1,25(OH)2D3 on plasma calcium, bone weight and duodenal calcium binding protein in chicken, on calcium excretion via egg shell in Japanese quails and on mobilization of calcium from the bone in rats was twice as high as the effect of the most potent naturally occurring vitamin D3 metabolite 1,25(OH)2D3. In contrast, 24R-F-1,25(OH)2D3 has less than 50% of the potency of 1,25(OH)2D3. Due to the wider therapeutic dosage range, this compound might be of clinical value.

Animals↗
PubMed1978

Gas exchange of the fertile hen's egg: components of resistance.

The resistance to diffusion of respiratory gases falls by 50% from day 10 to day 18 in the incubating fertile hen's egg (Temple and Metcalfe, 1970). We have calculated the change in the components of this resistance with respect to incubation age. The egg shell resistance remains unchanged. The chorioallantoic membrane (including capillary endothelium) resistance decreases dramatically from day 10 to day 14 and then remains relatively unchanged. The resistance offered by the blood is unchanged from day 10 to day 12, it decreases by day 14 due to an increase in oxygen capacity and continues to decline at days 16 and 18 because of the combined effects of a continued increase in oxygen capacity and an increase in capillary volume.

Allantois↗
PubMed1979

[Distribution of organic and inorganic carbon in tissues containing calcium carbonate by secondary ion emission microanalysis].

The differences of emissivity of secondary ions at masses 12 (C+ and C-), 24 (C2-) and 26 (C2H2- or CN-) of organic moitie and CO3Ca of semi thin sections of egg shell of quail allow the distinction between organic and inorganic carbon on images obtained with Secondary Ion Mass Spectroscopy. There differences of emissivity do not correspond only to the difference of concentration but to the difference of ionic yield. The emissivity at mass 26 (C2H2- or CN-) is higher than those obtained at mass 24 (C2-) in glycoproteinic material (rich in Nitrogen) and lower in the embedding material (Araldite, poor in Nitrogen). This result indicates that the ion present at mass 26 could by CN- rather than C2H2-.

Animals↗
PubMed2006

Salicylic acid permeation: a comparative study with different vehicles and membranes.

Considering the skin's function, different dermal pharmaceutical forms can be developed according to the type of therapeutic activity, active principle and excipients involved in the formulation, such as "transdermal preparations". In the present study, the permeation parameters of the non-steroidal anti-inflammatory drug, salicylic acid (SA) through synthetic membrane, polyvinyliden difluoride, and a biological membrane, egg shell membrane, with different vehicles, propylene glycol, isopropyl alcohol and carbopol gel, were determined. The reported physicochemical parameters of SA from CG were significantly higher than those obtained using PG and IP. This is attributed to the lipophilic nature of the vehicle that facilitates the release and penetration of the active principle, thus acting sinergically. The permeation profiles of SA allow us to state that permeation kinetics is of first order, so that the flux values obtained are in direct proportion to the specific rates of drug release.

2-Propanol↗
PubMed1980

The influence of gas composition in the air cell on pipping and liver metabolism in embryonic chicks.

In chick embryos, time of pipping is accelerated after repeated gassing the air cell with N2, CO2, or by sealing the egg shell in the area of the air cell with glue. Gassing the air cell with 95% O:2-5% CO2, or pure O2, was followed by a retardation of pipping. Furthermore, gassing with N2, or sealing the air cell with glue, exerted an accelerating effect on the decrease of hepatic glycogen and ATP. Following gassing with 95% O2-5% CO2, the reverse effect on glycogen and ATP was observed. It is suggested that the increase of the CO2/O2 ratio, occurring in the air cell at the end of incubation, acts as a stimulus for both pipping and metabolic changes in the liver.

Animals↗
PubMed1996

Effect of mebendazole and ivermectin in experimental hepatic capillariasis B: histopathological and ultrastructural studies.

Although, rodents are the principle hosts of C. hepatica both true and spurious human infections have been reported. Over half of the reported cases, resulted in death with hepatic capillariasis being discovered at autopsy; even in cases which the infection was detected at laparotomy or liver biopsy, the patient died due to the lack of suitable treatment. Therefore, studies on experimental C. hepatica in mice were carried out on the way of reaching a full program for treatment. The drugs used were mebendazole and ivermectin. The alterations noted in the egg shell by TEM suggest the effectiveness of the drugs used, the eggs appeared to be deformed; the outer shell was broken and distorted in several places. Many pillars were fragmented. The inner layer was also affected, where it showed destruction of its outer lamellae. Ultrastructural changes in the liver cells showed dysplastic changes. It may be a sequelae of mechanical injury or direct antigenic insult of the parasite or their toxins on the liver cells. During the course of the present work, it was noticed that most of the granulomata were in the fibrotic stage denoting acceleration in the process of healing of the lesions and no freshly deposited ova and hence no active cellular granuloma.

Animals↗
PubMed1989

Restricted feeding in early and late-feathering chickens. 2. Reproductive responses.

Reproductive traits of females from a broiler-breeder parent stock segregating for early and late feathering were measured under four feeding regimens. Feeding regimens consisted of ad libitum (AL, feed was always available), ad libitum restricted (ALR, feed restricted daily to control body weight), and skip-one-day and skip-two-days (SOD and STD, given two or three times ALR allowance on Day 1 and not fed on the next 1 or 2 days, respectively). At 160 days of age, pullets on SOD and STD were changed to ALR feeding, and daily feed allowances were increased to 135 g by Day 180 and 138 g by Day 250. Early and late feathering chickens responded similarly, except that hen-day ovulation rates, relative egg shell weights, and incidences of extracalcified and compressed eggs were greater for the former than the later. For most traits measured, differences among restricted feeding regimens were minor, but considerable differences were noted between them and the AL regimen. Females fed AL reached sexual maturity approximately 60 days earlier than those whose feed intake was restricted. Also, body weights at onset of lay were about 1,200 g greater for AL than for feed-restricted females. Percentages of hen-day ovulation, normal egg production, and duration of fertility were lower, whereas incidence of defective eggs was higher for AL than for feed-restricted chickens.

Animal Husbandry↗
PubMedDate not supplied

Presence and recovery of Ascaridia dissimilis ova on the external shell surface of turkey eggs.

Ascaridia dissimilis, a roundworm in turkeys, has been noted with increased frequency in commercial turkeys. Because infected turkeys can shed A. dissimilis ova in their feces, the potential exists for the external surface of turkey eggshells to be contaminated with A. dissimilis ova. The objectives of this study were to determine the presence of and recover A. dissimilis ova on the external surface of the turkey egg. In Experiment 1, turkey eggs were collected from naturally infected flocks, and eggs were processed by a sodium hydroxide procedure to recover any A. dissimilis ova on the external egg surface. In Experiment 2, the external surface of the turkey eggs was inoculated with 116 A. dissimilis ova/g feces, and eggshells were sampled every 3 days until 28 days of incubation to assess the recovery of A. dissimilis ova from the eggshell. In Experiment 1, of the 36 eggs examined from a flock naturally infected with A. dissimilis, one egg had an A. dissimilis ovum on its external eggshell surface. Experiment 2 demonstrated that A. dissimilis ova can be recovered from the external egg surface after a 28-day incubation period in the incubator. Ova recovery declined from an average of 62 A. dissimilis ova/turkey egg at day 2 of incubation to an average of 3 A. dissimilis ova/turkey egg at day 28 of incubation.

Animals↗
PubMed1983

Mechanism of action of praziquantel on the eggs of Schistosoma japonicum.

The mode of action of praziquantel on Schistosoma japonicum eggs was examined in mice and in vitro. In a long term oogram observation of mouse intestine, lasting from 1 to 56 days after oral administration of 100 mg/kg 4 times in one day, many empty egg shells were observed from the next day. Immature eggs, however, were not killed, but developed into miracidia that later degenerated into granulated and calcified eggs. In the oograms of mouse, from 5 to 240 minutes after a single oral dose of 100 mg/kg of praziquantel, miracidium hatching occurred 5 minutes in the tissues after treatment. In the in vitro experiment, miracidia in eggs from cut pieces of intestine began to hatch starting 5 minutes after exposure to praziquantel at least at a concentration of 1 ng/ml and reached maximum hatching at 30 minutes and died in several minutes after hatching.

Animals↗
PubMed1980

Effects of DDE, TDE, and PCBs on shell thickness of western grebe eggs, Bear River Migratory Bird Refuge, Utah--1973-74.

DDE, TDE, and polychlorinated biphenyls (PCBs) as Aroclors 1260 and 1254 were detected in low concentrations in eggs of western grebes (Aechmophorus occidentalis) from Bear River Migratory Bird Refuge, Utah. DDE was the only contaminant which was both negatively correlated with eggshell thickness and a significant variable in a multiple regression model for predicting eggshell thickness. The eggshell thickness index for western grebe decreased 2.3 percent from pre- to post-DDT-use periods. Incubation stage appeared to have no measurable correlation with eggshell thickness. The small amount of eggshell thinning seen in western grebe eggs at Bear River Migratory Bird Refuge appeared to have no detectable effect on reproduction.

Animals↗
PubMed1989

Effect of blood meal and mating on the genital tract ultrastructure in the female camel tick Hyalomma (Hyalomma) dromedarii (Ixodoidea: Ixodidae).

The genital tract ultrastructure in the female Hyalomma (Hyalomma) dromedarii is described during feeding and mating and up to oviposition. The vagina, consisting of vestibular (VV) and cervical (CV) regions, is formed of an epithelium lined internally with a folded cuticular layer and surrounded externally by muscle layers. These facilitate the passage of endospermatophores containing sperm into the receptaculum seminis (RS), and ova to the exterior. A pair of tubular accessory glands (AG) opening at the junction of VV and CV consist of an epithelial layer of undifferentiated cells. As feeding progresses, these cells synthesise their granular secretion which lubricates the egg surface during its passage through VV. The RS, opening anteriorly into the CV, consists of cuboidal cells lined with a thin cuticular layer. These cells become rich in glycogen and lipid vacuoles, possibly acting as a source of energy for various cell activities including granule synthesis and exocytosis. The granules discharge their contents into intercellular spaces distributed throughout the RS wall and communicate with the main lumen via narrow channels. The cell secretion may dissolve the endospermatophore wall to release sperm, while their lysosome-like structures may function in the breakdown of endospermatophoric material taken up by pinocytosis. The connecting tube (CT) opens into the CV anterodorsally and leads into the common oviduct (COV) posteriorly. It consists of an epithelium lined by a closely-adhering cuticular layer, giving the tube lumen the appearance of an undulate labyrinth with a complicated configuration. No secretory activity in the CT has been observed before, during, or after feeding. The paired, non-cuticular oviducts, extending from the ovary and fusing anteriorly to form COV, consist of an epithelium poor in cell organelles. At the final stages of feeding the cell cytoplasm contains large, phagosomal vacuoles penetrated by sperms, in addition to micropinocytotic vesicles which serve to break down the seminal fluid and other materials. The basal membrane is infolded giving characteristic features, which increase dramatically during oviposition, of epithelia involved in ion and water transport. The oviducal secretion may function as a tanning agent to harden the egg-shell and may also act as a lubricant for egg passage.

Animals↗
PubMed1980

Eosinophils as effector cells in the destruction of Schistosoma mansoni eggs in granulomas.

Histopathological sections of wedge-biopsied liver and surgically removed gallbladder of a schistosomiasis mansoni patient were studied for the eosinophil-mediated destruction of eggs in granulomas. Apparent degranulation of eosinophils on the eggs in the granulomas and concomittant deterioration of miracidia were observed. It was construed that granule-associated enzymes may be released upon the degranulation of eosinophils, pass through the micropores of the egg shell and cause death of the miracidium inside the egg.

Eosinophils↗