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PubMedDate not supplied

Abnormal calcifications in the urinary tract.

A wide variety of calcifications may develop in the urinary tract. Calculi, the most common form of urinary tract calcification, are usually radiopaque due to their calcium content, whereas cystine stones tend to be less opaque. In cortical nephrocalcinosis, calcification may be spotty or may appear as a thin rim outlining the cortex. Intracystic calcification is usually thin and peripheral and is often described as having an "eggshell" appearance. In renal masses, pure central calcification usually indicates malignancy, although malignancy may also be present with pure peripheral calcification. An incomplete ring of calcification seen over the central portion of the kidney should suggest the presence of an abnormal vascular structure. A sloughed papilla may lead to calcification that is usually triangular or ring-shaped or has a broken rim pattern. Ureteral calculi usually have a uniform radiopacity, whereas phleboliths are often less opaque centrally. Like renal calculi, bladder calculi usually contain a calcium component; they may be laminated, faceted, spiculated, or seedlike in appearance. Urachal carcinoma is commonly associated with tumor calcification, which typically occurs at the dome of the bladder. Schistosomiasis of the bladder may produce mural calcification with a typical thin arcuate pattern and may be associated with calcification in other portions of the urinary tract. Although urinary tract calcifications may be difficult to characterize specifically, they can be classified according to location, appearance, and relation to various pathologic conditions.

Calcinosis↗
PubMedDate not supplied

Pneumoconiosis: comparison of imaging and pathologic findings.

Pneumoconiosis may be classified as either fibrotic or nonfibrotic, according to the presence or absence of fibrosis. Silicosis, coal worker pneumoconiosis, asbestosis, berylliosis, and talcosis are examples of fibrotic pneumoconiosis. Siderosis, stannosis, and baritosis are nonfibrotic forms of pneumoconiosis that result from inhalation of iron oxide, tin oxide, and barium sulfate particles, respectively. In an individual who has a history of exposure to silica or coal dust, a finding of nodular or reticulonodular lesions at chest radiography or small nodules with a perilymphatic distribution at thin-section computed tomography (CT), with or without eggshell calcifications, is suggestive of silicosis or coal worker pneumoconiosis. Magnetic resonance imaging is helpful for distinguishing between progressive massive fibrosis and lung cancer. CT and histopathologic findings in asbestosis are similar to those in idiopathic pulmonary fibrosis, but the presence of asbestos bodies in histopathologic specimens is specific for the diagnosis of asbestosis. Giant cell interstitial pneumonia due to exposure to hard metals is classified as a fibrotic form of pneumoconiosis and appears on CT images as mixed ground-glass opacities and reticulation. Berylliosis simulates pulmonary sarcoidosis on CT images. CT findings in talcosis include small centrilobular and subpleural nodules or heterogeneous conglomerate masses that contain foci of high attenuation indicating talc deposition. Siderosis is nonfibrotic and is indicated by a CT finding of poorly defined centrilobular nodules or ground-glass opacities.

Aged↗
PubMed1994

Calcium uptake by chorioallantoic membrane: effects of vitamins D and K.

The chorioallantoic membrane (CAM) of birds is an epithelial tissue that actively transports large amounts of Ca during embryonic development. In this study the effect of vitamins D and K on Ca uptake by the CAM was studied. Four dietary treatments were used to produce eggs that are the following: deficient in vitamins D and K (-D/-K), sufficient in both (+D/+K), or deficient in one and sufficient in the other (-D/+K or +D/-K). Vitamin D-deficient (-D) Japanese quail embryos (from hens fed 1,25-dihydroxyvitamin D3) do not hatch because of severe Ca deficiency resulting from their inability to obtain Ca from shell, whereas vitamin K deficiency results in only 14% reduction in hatchability. The results demonstrate that Ca uptake by CAM is vitamin D dependent and only slightly vitamin K dependent. Ca-binding activity of CAM extracts was unchanged by vitamin K deficiency, and only a small increase was provided by vitamin D treatment. Vitamin D stimulated both Ca entry and exist from the chorion cells as indicated by the increased accumulated 45Ca in +D embryos. We conclude that vitamin D is essential for the utilization of eggshell Ca by the developing embryo and hence its survival, suggesting that Ca transport across the CAM is largely a vitamin D-dependent process.

Allantois↗
PubMed1989

Adrenergic regulation of calcium-deficient hypertension in chick embryos.

Chick embryos rendered calcium deficient by long-term culture outside the eggshell develop hypertension and tachycardia (R. Tuan and H. Q. Nguyen, J. Exp. Med. 165: 1418-1423, 1987). To characterize the hypertension of cultured shell-less (SL) chick embryo, we have compared their cardiovascular response to adrenergic drugs with normal (NL) embryos at day 14 of incubation. Blood pressure and pulse rate were measured before and after administration of norepinephrine (NE), phentolamine (PA), isoproterenol (IP), and propranolol (PP). Base-line blood pressures (systolic and diastolic) were uniformly higher in SL than NL embryos. In both embryos, blood pressure was elevated by NE and PP but lowered by IP and PA; pulse rates were decreased by PP and PA and increased by NE and IP. Pharmacological sensitivity to NE and PA, based on their effective dosages and magnitude of response in blood pressure and pulse rate, was higher in SL embryos. On the other hand, the embryos did not differ significantly in their sensitivity to IP and PP. The plasma concentration of catecholamines was considerably higher in SL embryos. Although serum calcium was lower in SL embryos, myocardial calcium content was not significantly different. Thus the cardiovascular function of SL embryos is likely to be under more sensitive and potentiated alpha-adrenergic regulation, perhaps a result of different calcium handling by several tissues (e.g., myocardium). These properties of the SL chick embryo indicate that it is a novel and useful experimental system to study the relationship between calcium homeostasis and development of hypertension.

Animals↗
PubMed1998

Development of heart rate irregularities in chick embryos.

Heart rate (HR) irregularities in chick embryos were defined as large fluctuations (>10 beats/min) comprising irregular, brief deceleration and/or acceleration of instantaneous HR (IHR). IHR was determined directly from the arterial blood pressure while adequate gas exchange was maintained through an eggshell and chorioallantoic membrane. Five embryos were examined on each day from day 11 to day 19 of incubation. Baseline HR was stable until day 12-13, and on around day 13-14 transient, rapid deceleration of HR (termed V pattern) began to appear, with a subsequent increase in its frequency and magnitude. The acceleration patterns (lambda, avian omega, and periodic patterns) appeared later, and the IHR became increasingly irregular, with additional, spontaneous deceleration and acceleration patterns toward hatching. Additional experiments with intravenous administration of autonomic drugs clearly showed that rapid deceleration of HR was mediated by parasympathetic nervous function but did not always show clear relations of sympathomimetic and sympathetic blocking agents to the acceleration patterns.

Allantois↗
PubMed1985

Gas exchange and hatchability of chicken eggs incubated at simulated high altitude.

Chicken eggs laid at sea level were incubated at sea level (control conditions), at a simulated altitude of 5.5 km without any further measures (natural conditions), and at a simulated altitude of 5.7 km at optimal incubator gas composition (optimal conditions). Under optimal conditions the incubator relative humidity was 70% throughout incubation, the gas mixture supplied to the incubator contained 45% O2-55% N2, and the ventilation rate was reduced to 6% of control in order to maintain the normal air-space gas tensions and to compensate for the increased eggshell conductance at altitude. The embryos that developed under control conditions showed a normal CO2 production with 94% hatchability of fertile eggs. Under natural conditions at altitude all embryos died within a few days. Optimal conditions resulted in an almost normal gas exchange and in an improvement of hatchability from 0 to 81% of fertile eggs.

Altitude↗
PubMed2000

Late cutaneous schistosomiasis representing an isolated skin manifestation of schistosoma mansoni infection.

Ectopic late cutaneous schistosomiasis is usually preceded or accompanied by visceral schistosomiasis infection. Our patient presented the very rare case of late cutaneous schistosomiasis as an isolated skin manifestation. Perigenital lesions occurred 1 year after contact with infested water. Identification of the few eggs remaining in the late lesion among the dense cellular infiltrate was difficult. Electron-microscopic studies clearly demonstrated the characteristic eggshell ultrastructure.

Adult↗
PubMed1997

Study of the structure of struvite stones with scanning electron microscopy and energy-dispersive X-ray microanalysis.

Topographic features of eight struvite calculi were investigated with scanning electron microscopy (SEM) equipped with energy-dispersive X-ray microanalysis (EDX). Perpendicularly cracked fragments showed concentric laminations composed of compact and loosely packed strata alternately. Magnesium and phosphorus were detected in the compact strata with their characteristic dispersive X-ray spectra. There existed numerous spherular crystals with smooth or porous surfaces and scattered penta- or hexa-hedral coffin-lid shaped crystals in the loosely packed strata. The former crystals showed the dispersive X-ray spectra of calcium and phosphorus, and were estimated to be calcium phosphate (CaP). The latter ones were presumed to be magnesium ammonium phosphate (MAP) with EDX. The surfaces of the fragments were cracked like eggshells and displayed numerous CaP crystals and scattered MAP crystals in most cases, while in only 1 case some faces of pieces demonstrated wavy MAP phases, sundry areas which were rimmed with aggregated CaP spherulites. The mean molar ratios of Mg/P and Ca/P in each case were 0.88-1.03 and 1.25-1.52, respectively. Though EDX was inadequate to determine the accurate chemical formula of CaP and MAP crystals by detecting their molar ratios of Ca/P and Mg/P with EDX, SEM/EDX is useful to observe these urolith crystals and to surmise them to be CaP or MAP crystals by detecting their atomic elements with EDX.

Adult↗
PubMed1980

Sarcoidosis of anterior mediastinal nodes, pancreas, and uterine cervix: three unusual sites in the same patient.

Sarcoidosis rarely involves anterior mediastinal nodes, pancreas, or uterine cervix. A 47-yr-old woman with sarcoidosis was found to have enlargement of the anterior mediastinal lymph nodes with "eggshell" calcifications on a lateral chest roentgenogram. This finding was confirmed by lateral tomography and thoracic computerized tomography. A review of 100 lateral chest roentgenograms of patients with documented sarcoidosis failed to reveal other examples of anterior mediastinal node enlargement. At laparotomy for total abdominal hysterectomy, a mass in the head of the pancreas and diffuse, nodular enlargement of this organ was found. A pathologic study of the pancreas and uterine endocervix demonstrated noncaseating granulomas. Sarcoidosis in these 3 unusual sites is discussed.

Female↗
PubMed2004

Interaction of glass-ionomer cements with moist dentin.

Glass-ionomer cements (GICs) are regarded as aqueous gels made up of polyalkenoic acid salts containing ion-leachable glass fillers. The consequence of water permeation across the GIC-dentin interface is unknown. This study used SEM, field-emission/environmental SEM (FE-ESEM), and TEM to examine the ultrastructure of GIC-bonded moist dentin. Dentin surfaces bonded with 6 auto-cured GICs were examined along the fractured GIC-dentin interfaces. Additional specimens fractured 3 mm away from the interfaces were used as controls. SEM revealed spherical bodies along GIC-dentin interfaces that resembled hollow eggshells. FE-SEM depicted similar bodies with additional solid cores. Energy-dispersive x-ray analysis and TEM showed that the spherical bodies consisted of a silicon-rich GIC phase that was absent from the air-voids in the controls. The GIC inclusions near dentin surfaces result from a continuation of the GI reaction, within air-voids of the original polyalkenoate matrix, that occurred upon water diffusion from moist dentin.

Adhesiveness↗
PubMed2001

Calcium dynamics during fertilization in C. elegans.

BACKGROUND: Of the animals typically used to study fertilization-induced calcium dynamics, none is as accessible to genetics and molecular biology as the model organism Caenorhabditis elegans. Motivated by the experimental possibilities inherent in using such a well-established model organism, we have characterized fertilization-induced calcium dynamics in C. elegans. RESULTS: Owing to the transparency of the nematode, we have been able to study the calcium signal in C. elegans fertilization in vivo by monitoring the fluorescence of calcium indicator dyes that we introduce into the cytosol of oocytes. In C. elegans, fertilization induces a single calcium transient that is initiated soon after oocyte entry into the spermatheca, the compartment that contains sperm. Therefore, it is likely that the calcium transient is initiated by contact with sperm. This calcium elevation spreads throughout the oocyte, and decays monotonically after which the cytosolic calcium concentration returns to that preceding fertilization. Only this single calcium transient is observed. CONCLUSION: Development of a technique to study fertilization induced calcium transients opens several experimental possibilities, e.g., identification of the signaling events intervening sperm binding and calcium elevation, identifying the possible roles of the calcium elevation such as the completion of meiosis, the formation of the eggshell, and the establishing of the embryo's axis of symmetry.

Animals↗
PubMed2005

Microsatellite mapping of QTL affecting growth, feed consumption, egg production, tonic immobility and body temperature of Japanese quail.

BACKGROUND: The Japanese quail (Coturnix japonica) is both an animal model in biology and a commercial bird for egg and meat production. Modern research developments with this bird, however, have been slowed down by the limited information that is available on the genetics of the Japanese quail. Recently, quail genetic maps with microsatellites and AFLP have been produced which open the way to comparative works with the chicken (Gallus gallus), and to QTL detection for a variety of traits. The purpose of this work was to detect for the first time QTL for commercial traits and for more basic characters in an F2 experiment with 434 female quail, and to compare the nature and the position of the detected QTL with those from the first chicken genome scans carried out during the last few years. RESULTS: Genome-wide significant or suggestive QTL were found for clutch length, body weight and feed intake on CJA01, age at first egg and egg number on CJA06, and eggshell weight and residual feed intake on CJA20, with possible pleiotropy for the QTL affecting body weight and feed intake, and egg number and age at first egg. A suggestive QTL was found for tonic immobility on CJA01, and chromosome-wide significant QTL for body temperature were detected on CJA01 and CJA03. Other chromosome-wide significant QTL were found on CJA02, CJA05, CJA09 and CJA14. Parent-of-origin effects were found for QTL for body weight and feed intake on CJA01. CONCLUSION: Despite its limited length, the first quail microsatellite map was useful to detect new QTL for rarely reported traits, like residual feed intake, and to help establish some correspondence between the QTL for feed intake, body weight and tonic immobility detected in the present work and those reported on GGA01 in the chicken. Further comparative work is now possible in order to better estimate and understand the genetic similarities and differences of these two Phasianidae species.

Animals↗
PubMed2003

Developmental defects observed in hypomorphic anaphase-promoting complex mutants are linked to cell cycle abnormalities.

In C. elegans, mutants in the anaphase-promoting complex or cyclosome (APC/C) exhibit defects in germline proliferation, the formation of the vulva and male tail, and the metaphase to anaphase transition of meiosis I. Oocytes lacking APC/C activity can be fertilized but arrest in metaphase of meiosis I and are blocked from further development. To examine the cell cycle and developmental consequences of reducing but not fully depleting APC/C activity, we analyzed defects in embryos and larvae of mat-1/cdc-27 mutants grown at semi-permissive temperatures. Hypomorphic embryos developed to the multicellular stage but were slow to complete meiosis I and displayed aberrant meiotic chromosome separation. More severely affected embryos skipped meiosis II altogether and exhibited striking defects in meiotic exit. These latter embryos failed to produce normal eggshells or establish normal asymmetries prior to the first mitotic division. In developing larvae, extended M-phase delays in late-dividing cell lineages were associated with defects in the morphogenesis of the male tail. This study reveals the importance of dosage-specific mutants in analyzing molecular functions of a ubiquitously functioning protein within different cell types and tissues, and striking correlations between specific abnormalities in cell cycle progression and particular developmental defects.

Amino Acid Sequence↗
PubMed2004

Expression and release patterns of neuropeptides during embryonic development and hatching of the green shore crab, Carcinus maenas.

Crustacean ecdysis is controlled by at least three neuropeptides: moult-inhibiting hormone (MIH), which represses ecdysteroid synthesis; crustacean hyperglycaemic hormone (CHH), which not only influences ecdysteroid synthesis but also water uptake during moulting; and crustacean cardioactive peptide (CCAP), which is involved in stereotyped ecdysis behaviour. During embryonic development, moulting takes place in the egg, but there is little information regarding developmental expression of these neuropeptides during this period or during hatching--an event that is analogous to eclosion in insects. To address this problem, we determined expression profiles of MIH and CHH mRNA by quantitative RT-PCR, together with developmental peptide expression studies [confocal immunocytochemistry (ICC) and radioimmunoassay (RIA)]. Likely homologous events relating to neuropeptide surges of both CHH and CCAP were seen during larval hatching, when compared to the adult moult, and cell-specific copy concentration of both MIH and CHH mRNAs was identical to that of the adult during late embryonic development. We measured parallel mRNA and peptide expression of two neuropeptides (red pigment-concentrating hormone RPCH) and pigment-dispersing hormone (PDH) during development, as these have roles as neuromodulators and as classical neurohormonal roles. For MIH and CHH, gene expression was in accordance with peptide expression, but novel sites of CHH expression were found (abdominal peripheral neurones), the expression and release patterns of which may be related to larval eclosion and water uptake necessary for eggshell rupture and hatching. For RPCH and PDH, gene transcription and peptide expression were not in accordance. A significant contribution of maternally derived (non-translated) PDH mRNA to the embryo was seen, and for RPCH, high-level mRNA and peptide expression during late embryogenesis is related to a long ignored, but potentially important release site--the enigmatic post-commissural organs--which are the most prominent structures expressing RPCH during late embryogenesis.

Animals↗
PubMed2006

spn-F encodes a novel protein that affects oocyte patterning and bristle morphology in Drosophila.

The anteroposterior and dorsoventral axes of the Drosophila embryo are established during oogenesis through the activities of Gurken (Grk), a Tgfalpha-like protein, and the Epidermal growth factor receptor (Egfr). spn-F mutant females produce ventralized eggs similar to the phenotype produced by mutations in the grk-Egfr pathway. We found that the ventralization of the eggshell in spn-F mutants is due to defects in the localization and translation of grk mRNA during mid-oogenesis. Analysis of the microtubule network revealed defects in the organization of the microtubules around the oocyte nucleus. In addition, spn-F mutants have defective bristles. We cloned spn-F and found that it encodes a novel coiled-coil protein that localizes to the minus end of microtubules in the oocyte, and this localization requires the microtubule network and a Dynein heavy chain gene. We also show that Spn-F interacts directly with the Dynein light chain Ddlc-1. Our results show that we have identified a novel protein that affects oocyte axis determination and the organization of microtubules during Drosophila oogenesis.

Animals↗
PubMed2006

Capicua regulates follicle cell fate in the Drosophila ovary through repression of mirror.

The dorsoventral axis of the Drosophila egg is established by dorsally localized activation of the epidermal growth factor receptor (Egfr) in the ovarian follicular epithelium. Subsequent positive- and negative-feedback regulation generates two dorsolateral follicle cell primordia that will produce the eggshell appendages. A dorsal midline domain of low Egfr activity between the appendage primordia defines their dorsal boundary, but little is known about the mechanisms that establish their ventral limit. We demonstrate that the transcriptional repressor Capicua is required cell autonomously in ventral and lateral follicle cells to repress dorsal fates, and functions in this process through the repression of mirror. Interestingly, ectopic expression of mirror in the absence of capicua is observed only in the anterior half of the epithelium. We propose that Capicua regulates the pattern of follicle cell fates along the dorsoventral axis by blocking the induction of appendage determinants, such as mirror, by anterior positional cues.

Animals↗
PubMed1992

The Drosophila retinoid X receptor homolog ultraspiracle functions in both female reproduction and eye morphogenesis.

Ultraspiracle (usp) encodes the Drosophila cognate of RXR, the human retinoid X receptor. To examine how RXR subfamily members function in development, we have undertaken a phenotypic analysis of usp mutants. usp is required at multiple stages of development for functions that occur in a wide variety of tissues. usp is required in the eye-antennal imaginal disc for normal eye morphogenesis and in the somatic and germline tissues of adult females for fertilization, eggshell morphogenesis and embryonic development. An unusual sunken eye phenotype with marked ventral-dorsal polarity appears to be caused by a lack of usp function in the imaginal disc cells that reside between the eye and antennal anlage. The usp functions include cell autonomous and non-cell autonomous components, suggesting that usp controls the production of factors important for both cell-cell communication and cellular differentiation. These usp signalling pathways have mechanistic parallels to steroid and retinoid action in developing vertebrate tissues.

Animals↗
PubMed1994

Diaphanous is required for cytokinesis in Drosophila and shares domains of similarity with the products of the limb deformity gene.

We show that the Drosophila gene diaphanous is required for cytokinesis. Males homozygous for the dia1 mutation are sterile due to a defect in cytokinesis in the germline. Females trans-heterozygous for dia1 and a deficiency are sterile and lay eggs with defective eggshells; failure of cytokinesis is observed in the follicle cell layer. Null alleles are lethal. Death occurs at the onset of pupation due to the absence of imaginal discs. Mitotic figures in larval neuroblasts were found to be polyploid, apparently due to a defect in cytokinesis. The predicted 123 x 10(3) M(r) protein contains two domains shared by the formin proteins, encoded by the limb deformity gene in the mouse. These formin homology domains, which we have termed FH1 and FH2, are also found in Bni1p, the product of a Saccharomyces cerevisiae gene required for normal cytokinesis in diploid yeast cells.

Amino Acid Sequence↗