Eggshell Calcification Research Articles

Relationship between eggshell strength and keratan sulfate of eggshell membranes

Eggshell strength is an important factor in an effort to minimize eggshell breakage, which is a significant problem in the egg production industry. In the current study, we isolated and quantified the specific glycosaminoglycans (GAGs) from the calcified eggshell and shell membranes, which are related to eggshell strength. Our data suggest that GAGs exist in calcified eggshell may influence morphology of shell but do not affect on increase of shell amount while GAGs of shell membranes are maybe highly associated with shell strength with an increase of shell weight. Shell strength showed a strong correlation with the content of GAGs (r=0.942, p<0.0005) and a weak relationship with uronic acid content (r=0.564, p=0.056) in shell membranes. Monosaccharides in shell membranes were determined by Bio-LC analysis for the identification of any specific GAGs related with shell strength. It indicates that the galactose content as a component of keratan sulfate (KS) has a significant correlation with eggshell strength (r=0.985, p<0.0005). These results suggest that eggshell strength is proportional to the KS content of eggshell membranes with an increase of eggshell weight.

Cloning of Ovocalyxin-36, a Novel Chicken Eggshell Protein Related to Lipopolysaccharide-binding Proteins, Bactericidal Permeability-increasing Proteins, and Plunc Family Proteins

The avian eggshell is a composite biomaterial composed of noncalcifying eggshell membranes and the overlying calcified shell matrix. The shell is deposited in a uterine fluid where the concentration of different protein species varies at different stages of its formation. The role of avian eggshell proteins during shell formation remains poorly understood, and we have sought to identify and characterize the individual components in order to gain insight into their function during elaboration of the eggshell. In this study, we have used direct sequencing, immunochemistry, expression screening, and EST data base mining to clone and characterize a 1995-bp full-length cDNA sequence corresponding to a novel chicken eggshell protein that we have named Ovocalyxin-36 (OCX-36). Ovocalyxin-36 protein was only detected in the regions of the oviduct where egg-shell formation takes place; uterine OCX-36 message was strongly up-regulated during eggshell calcification. OCX-36 localized to the calcified eggshell predominantly in the inner part of the shell, and to the shell membranes. BlastN data base searching indicates that there is no mammalian version of OCX-36; however, the protein sequence is 20-25% homologous to proteins associated with the innate immune response as follows: lipopolysaccharide-binding proteins, bactericidal permeability-increasing proteins, and Plunc family proteins. Moreover, the genomic organization of these proteins and OCX-36 appears to be highly conserved. These observations suggest that OCX-36 is a novel and specific chicken eggshell protein related to the superfamily of lipopolysaccharide-binding proteins/bactericidal permeability-increasing proteins and Plunc proteins. OCX-36 may therefore participate in natural defense mechanisms that keep the egg free of pathogens.

Eggshell calcification of kidney in ureteropelvic junction obstruction

Eggshell calcification of kidney in case of ureteropelvic junction obstruction (UPJO) is an uncommon finding with only a few cases reported in literature. We report a thirty-year-old symptomatic man with curvilinear calcification in hydronephrotic right kidney. Thorough investigations to rule out genitourinary tuberculosis and hydatid disease of kidney were performed prior to the definitive management by laparoscopic approach.

MDCT detection of an atherosclerotic coronary artery aneurysm: Evaluation by Plaque Map

A 54-year-old man who had history of hypertension was admitted to our hospital complaining of exertional chest pain. He did not have episodes of Kawasaki disease. Electrocardiogram showed q waves in III and aVF. Echocardiogram revealed dilatation of the left ventricle (LVDd/s 74/56 mm) and akinesis in the inferior and posterolateral left ventricular segments. Exercise thallium-201 scintigram demonstrated a fixed defect in the inferior and posterolateral left ventricular segments, indicating infarction in the right coronary artery territory. Multidetector-row computed tomography (MDCT) was performed using a LightSpeed Ultra (GE Systems, USA) with the slice thickness of 1.25 mm; pitch of 0.3:1; gantry rotation time of 0.5 s; temporal resolution of 125 ms and the trigger point of 70–80% R-R. The 80 ml of contrast medium (Omnipaque 300; Daiichi Pharmaceutical Co., Ltd., Tokyo, Japan) was used. Curved multiplanar reformation (MPR) image showed coronary aneurysm in the left anterior descending artery (Fig 1). Cross-sectional images of the aneurysm were converted into Plaque Map [ 1 Komatsu S. Hirayama A. Omori Y. et al. Detection of Coronary Plaque by Computed Tomography with the Novel Plaque Analysis System “Plaque Map” and Comparison with Intravascular Ultrasound and Angioscopy. Circ J. 2005; 69: 72-77 Crossref PubMed Scopus (88) Google Scholar , 2 Komatsu S. Omori Y. Murakawa T. et al. Detection of Plaque of Saphenous Vein Graft by Multislice Computed Tomography and Comparison with Gray-scale/Virtual Histology Intravascular Ultrasound. Int J Cardiol. 2005; ([Electronic publication, December 22]) Google Scholar ] which disclosed an eccentric CT-low-dense layer suggesting an atherosclerotic plaque (Fig. 1B). Egg-shell like calcification typical to Kawasaki disease [ [3] Kanamaru H. Sato Y. Takayama T. et al. Assessment of coronary artery abnormalities by multislice spiral computed tomography in adolescents and young adults with Kawasaki disease. Am J Cardiol. 2005; 95: 522-525 Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar ] was not observed. Left coronary angiogram showed a spindle-shaped aneurysm in the left anterior descending artery and occlusion in the left circumflex artery (Fig. 1C) and right coronary angiogram disclosed high-grade stenosis (Fig. 1D). For further analysis of the aneurysm texture, intravascular ultrasound (IVUS) and coronary angioscopy were performed. IVUS revealed an eccentric, hypoechoic layer (Fig. 2A ) and coronary angioscopy demonstrated a grade 3 [ [4] Ueda Y. Asakura M. Yamaguchi O. et al. The healing process of infarct-related plaques. Insights from 18 months of serial angioscopic follow-up. J Am Coll Cardiol. 2001; 38: 1916-1922 Abstract Full Text Full Text PDF PubMed Scopus (111) Google Scholar ] yellow plaque (Fig. 2B), findings consistent with a lipid-rich atherosclerotic plaque. The patient underwent stent implantation in the right coronary artery. Anticoagulation therapy with warfarin was started for preventing further thrombus formation within the aneurysm. Fig. 2(A) Intravascular ultrasound images in the proximal (left) and middle (right) portions of the aneurysm showing an eccentric hypoechoic layer (arrows). (B) Coronary angioscopic images showing a grade 3 yellow plaque (arrows). View Large Image Figure Viewer Download Hi-res image

Transbrachial insertion of a 7.5-Fr intra-aortic balloon pump in a severely atherosclerotic patient*

Preoperative intra-aortic balloon pumping (IABP) improves the results of complex coronary surgery. However, its insertion may be harmful or contraindicated in cases of severe and diffuse atherosclerosis of the descending aorta and peripheral arteries. We sought to evaluate the efficacy and safety of transbrachial insertion of the new 7.5-Fr IABP to support a severely ill patient with eggshell distal aorta and femoro-iliac arteries undergoing coronary artery bypass grafting (CABG). Case report. An 18-bed adult cardiac surgery unit at a university hospital. A 68-yr-old man with ongoing unstable angina, left main disease, and eggshell calcification in the abdominal aorta and iliaco-femoral arteries, needing IABP for CABG. Percutaneous sheathless right transbrachial insertion of 7.5-Fr IABP, followed by CABG. Fluoroscopy and chest radiograph were used to confirm the exact position of the IABP, in the preoperative and postoperative time, respectively. A digital pulse oximeter was applied to monitor distal perfusion. Anticoagulation consisted of nadroparin 4000 IU daily until the second postoperative day, followed by 150 mg of aspirin daily thereafter. Transbrachial IABP support allowed uneventful CABG and postoperative course, without IABP-related complications. Pulse oximetry demonstrated constant good values, the radial artery pulse was always present, and the hand appeared constantly warm. IABP was withdrawn 20 hrs following surgery, and the patient was discharged home on the ninth postoperative day. The miniaturization of IABP, with the recent introduction of a 7.5-Fr balloon catheter, opens the door for the safe, effective transbrachial method of insertion in patients with severe peripheral atherosclerosis.

Neck pain: an unusual presentation of a common disease

A 68-year-old man presented with 1 month history of neck pain, progressively worsening sensory dysfunction in the right hand, weakness of both hands and difficulty walking. On clinical examination he was found to have reduced power in both upper and lower limbs, with upgoing plantar reflexes. MRI was performed using a Philips Gyroscan 1.5 T machine using sagittal T1 weighted turbo spin echo (TSE; repetition time (TR) 400/echo time (TE) 10, matrix 512, field of view (FOV) 2556255, slice thickness 3.0 mm/ 0.3 mm, number of signal averages (NSA) 4), T2 weighted TSE (TR 3500/TE 120, matrix 512, FOV 2556255, slice thickness 3.0 mm/0.3 mm, NSA 4) and axial T2 weighted turbo field echo (TFE, TR 7.8/TE 3.9, flip angle 45 , matrix 512, FOV 2256225, slice thickness 3.5 mm/21.8 mm, NSA 3) sequences. Post-contrast sagittal (as above) and axial T1 weighted TFE (TR 9.4/ TE 4.6, flip angle 25 , matrix 512, FOV 24562.4, slice thickness 4.0 mm/22.0 mm, NSA 4) sequences were also performed from C3 to D1 level. MRI demonstrated a destructive lesion involving the right facet joint of C4/5 associated with a medially placed extradural mass of intermediate signal on T1 weighted images, intermediate heterogeneous signal on T2 weighted images which showed peripheral contrast enhancement postgadolinium (Figure 1). Enhancement was also present in the joint and surrounding soft tissues. The soft tissue mass was compressing and displacing the spinal cord and intrinsic high signal was present in the cord on T2 weighted sequences. Similar but less severe changes were also present in the right C2/C3 facet joint. A CT scan performed to look for bony changes revealed subtle eggshell calcification noted around the extradural mass and well-defined erosive changes involving the facets of C2/C3, C3/C4 and C4/C5 (Figure 2). What is the differential diagnosis? Address correspondence to: Dr Tufail Patankar, 30 Windy Hill Drive, Bolton BL3 4TH, UK. The British Journal of Radiology, 79 (2006), 537–539

2167: Thyroid nodule with peripheral rim (eggshell) calcification. Is It the most reliable sign of a benign nodule?

Objectives: To assess benignity of peripheral rim (eggshell) calcification in thyroid nodule.Methods: Consecutive US guided FNA was performed in 33 thyroid nodules with peripheral rim (eggshell) calcification in 32 patients from September 2002 to October 2005. Follow up FNA was performed two to four times in seven patients.Results: FNA cytology results were 7 (21.2%) malignant (papillary carcinoma), 24 (72.7%) benign, and 2 (6.0%) no follicular cell. One malignant nodule was diagnosed at follow up FNA cytology (at first, benign). One nodule underwent four times of US-guided FNA showed atypical cell two times and benign two times, and this nodule was included in benign group. The mean long diameters of the nodules on sonogram were 9.1 mm (5 mm to 15 mm) in malignant, 9.1 mm (4 mm to 17 mm) in benign and 12.5 mm (10 mm to 15 mm) in no follicular cell groups.Conclusions: Peripheral rim (eggshell) calcification was not the most reliable sign of benign thyroid nodule. Objectives: To assess benignity of peripheral rim (eggshell) calcification in thyroid nodule. Methods: Consecutive US guided FNA was performed in 33 thyroid nodules with peripheral rim (eggshell) calcification in 32 patients from September 2002 to October 2005. Follow up FNA was performed two to four times in seven patients. Results: FNA cytology results were 7 (21.2%) malignant (papillary carcinoma), 24 (72.7%) benign, and 2 (6.0%) no follicular cell. One malignant nodule was diagnosed at follow up FNA cytology (at first, benign). One nodule underwent four times of US-guided FNA showed atypical cell two times and benign two times, and this nodule was included in benign group. The mean long diameters of the nodules on sonogram were 9.1 mm (5 mm to 15 mm) in malignant, 9.1 mm (4 mm to 17 mm) in benign and 12.5 mm (10 mm to 15 mm) in no follicular cell groups. Conclusions: Peripheral rim (eggshell) calcification was not the most reliable sign of benign thyroid nodule.

PCBs and OCPs in sediments from Hongfeng Reservoir in Guizhou Province, China

Background: Radiographic signs of Pneumoconiosis found in farming Ladakhi despite absences of mines and industries were believed to be due to exposure to frequent dust storms and domestic fire pollutions. Seasonal Koilonychia (spoon nail) occurring predominantly in farming women in absences of iron deficiency anaemia was thought to arise from exposure to water made alkaline by weathering of hornblende minerals. The relation of these health conditions to environmental geohydrochemistry is postulated as the source of irrigation water in the affected population originates from glaciers in trans-Himalaya range of sedimentary geology and steep landscape favouring flushing of silica/silicate containing silts. Methods and results: Survey in two central Ladakh villages revealed radiographic evidence of silicosis in all middle aged women and half in middle aged men. In a large-scale study of 3105 subjects aged over 30 years from three villages; 101 (22.5%) of the 449 radiographed showed signs of pneumoconiosis (ILO 1980 criteria) including eggshell calcification of hilar gland and progressive massive fibrosis. Indoor dust analyzed using Philips 400T electron microscope with energy dispersive analysis system attached showed SiO2 levels upto 53.27% with particle size of 0.5 to 5.0 microns and the concentration during cooking period in the worst affected area was 7.495 mg/m 3. Microscopy and histopathology from the subject was characteristic of pneumoconiosis. Analysis of the inorganic dust in the lung showed 40.2% muscovite, 37.3% quartz with the extracted dust wt 147.9 mg/gm of dry tissue. Prevalence of chronic cough with chronic phlegm and percentage of villagers with FEV1/FVC ratio of less than 65% rose with age. Of 70 subjects studied 19 women and 2 men had Koilonychia with incidence being highest in summer. Absence of seasonal Koilonychia in villages fed by water derived from northern mountain range glaciers with mainly igneous geology supports our hypothesis. Conclusions: Clinical, epidemiological, radiological, environmental and histopathological studies and analysis of dust samples in the lungs proved beyond doubt that high prevalence of pneumoconiosis in central Ladakh is due to inhalation of respirable particles of SiO2 and soot. Seasonal Koilonychia in the study area with high pH and siliceous content of the soil in absence of iron deficiency anaemia support our hypothesis.

Environmental geohydrochemistry and health of the high altitude population in Ladakh

Background: Radiographic signs of Pneumoconiosis found in farming Ladakhi despite absences of mines and industries were believed to be due to exposure to frequent dust storms and domestic fire pollutions. Seasonal Koilonychia (spoon nail) occurring predominantly in farming women in absences of iron deficiency anaemia was thought to arise from exposure to water made alkaline by weathering of hornblende minerals. The relation of these health conditions to environmental geohydrochemistry is postulated as the source of irrigation water in the affected population originates from glaciers in trans-Himalaya range of sedimentary geology and steep landscape favouring flushing of silica/silicate containing silts. Methods and results: Survey in two central Ladakh villages revealed radiographic evidence of silicosis in all middle aged women and half in middle aged men. In a large-scale study of 3105 subjects aged over 30 years from three villages; 101 (22.5%) of the 449 radiographed showed signs of pneumoconiosis (ILO 1980 criteria) including eggshell calcification of hilar gland and progressive massive fibrosis. Indoor dust analyzed using Philips 400T electron microscope with energy dispersive analysis system attached showed SiO2 levels upto 53.27% with particle size of 0.5 to 5.0 microns and the concentration during cooking period in the worst affected area was 7.495 mg/m 3. Microscopy and histopathology from the subject was characteristic of pneumoconiosis. Analysis of the inorganic dust in the lung showed 40.2% muscovite, 37.3% quartz with the extracted dust wt 147.9 mg/gm of dry tissue. Prevalence of chronic cough with chronic phlegm and percentage of villagers with FEV1/FVC ratio of less than 65% rose with age. Of 70 subjects studied 19 women and 2 men had Koilonychia with incidence being highest in summer. Absence of seasonal Koilonychia in villages fed by water derived from northern mountain range glaciers with mainly igneous geology supports our hypothesis. Conclusions: Clinical, epidemiological, radiological, environmental and histopathological studies and analysis of dust samples in the lungs proved beyond doubt that high prevalence of pneumoconiosis in central Ladakh is due to inhalation of respirable particles of SiO2 and soot. Seasonal Koilonychia in the study area with high pH and siliceous content of the soil in absence of iron deficiency anaemia support our hypothesis.

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.

Regional and developmental variations of blood vessel morphometry in the chick embryo chorioallantoic membrane

Avian eggs contain all the necessary materials for embryonic development except for oxygen, which diffuses in from the environment via pores in the hard, calcified eggshell to the chorioallantoic membrane (CAM), the respiratory organ, which is rich in blood vessels. An air cell is formed at the blunt pole of the egg between the two membranes of the eggshell and enlarges during incubation due to water vapor loss. In this study of the CAM of chicken eggs, we compared blood vessel numerical density [N(A(v))], area fraction of blood vessels [A(A(v))], CAM thickness (D(CAM)), total length of blood vessels (L) and surface area of the CAM attached to the eggshell (CAMre) with those under the air cell (CAMac) during incubation. We found that N(A(v)), A(A(v)), D(CAM) and L of the CAM increase with embryonic age and development. The N(A(v)), A(A(v)) and L under the air cell were higher in relation to the rest of the CAM at all ages tested, while the D(CAM) under the air cell was always lower than around the rest of the egg. Since the eggshell over the air cell has a relatively greater porosity, and the respiratory gas exchange ratio there is higher than at other areas of the egg, there is a correlation between all the above morphometric data and the eggshell porosity. This suggests optimization of embryonic gas exchange in the chicken egg. We would like to propose that, during natural incubation, an increased gas diffusion under the air cell, together with increased blood vessel numerical density, may compensate for covering of the central part of the eggshell by the incubating parent.

Eggshell calcification in follicular thyroid carcinoma

Eggshell calcification in follicular thyroid carcinoma

Structure−Function Relationship of Avian Eggshell Matrix Proteins: A Comparative Study of Two Major Eggshell Matrix Proteins, Ansocalcin and OC-17

The role of individual matrix proteins in avian eggshell calcification is poorly understood despite numerous attempts to characterize and localize their presence in the eggshell matrix. Ansocalcin, the major matrix protein from goose eggshell, was found to induce the formation of calcite crystal aggregates under in vitro. Owing to its high similarity with the chicken eggshell matrix protein ovocleidin 17 (OC-17), a comparative investigation has been carried out to understand the structure-function relationship. RP-HPLC shows that ansocalcin is the major component in extracts of goose eggshells before and after bleach treatment. However, OC-17 was observed in minute quantities in the extract of bleach-treated chicken eggshells. In vitro crystal growth experiments showed that OC-17 and ansocalcin interact differently with the calcite crystals formed. Circular dichroism, intrinsic tryptophan fluorescence, and dynamic light scattering studies showed that, under the conditions used in our experiments, OC-17 does not aggregate in solution or induce the nucleation of calcite aggregates in the concentration range used. These observations indicate that OC-17 and ansocalcin play different roles in the eggshell calcification. To our knowledge, this is the first report on the comparison of properties of homologous eggshell proteins that belong to the same phylogeny.

Crystal Structure of Ovocleidin-17, a Major Protein of the Calcified Gallus gallus Eggshell: IMPLICATIONS IN THE CALCITE MINERAL GROWTH PATTERN

Ovocleidin-17 (OC17) from Gallus gallus is one of the best candidates to control and regulate the deposition of calcium carbonate in the calcified eggshell layer. Here, the crystal structure of monomeric OC17, determined at a resolution of 1.5 A, was refined to a crystallographic R-factor of 20.1%. This is the first protein directly involved in a non-pathological biomineralization process resolved by x-ray diffraction to date. The protein has a mixed alpha/beta structure containing a single C-type lectin-like domain. However, although OC17 shares the conserved scaffold of the C-type lectins, it does not bind carbohydrates. Nevertheless, in vitro OC17 modifies the crystalline habit of calcium carbonate (CaCO3) and the pattern of crystal growth at intervals of 5-200 microg/ml. Determining the three-dimensional structure of OC17 contributes to a better understanding of the biological behavior of structurally related biomolecules and of the mechanisms involved in eggshell and other mineralization processes.

Ostrich ( Struthio camelus) eggshell matrix contains two different C-type lectin-like proteins. Isolation, amino acid sequence, and posttranslational modifications

In contrast to chicken and goose, the ostrich calcified eggshell layer matrix contained two different C-type lectin-like proteins as major components. These proteins, named struthiocalcin-1 (SCA-1) and struthiocalcin-2 (SCA-2), were isolated and their amino acid sequence was determined. SCA-1 clearly was the ortholog of goose eggshell ansocalcin. Its amino acid sequence had the same length as that of ansocalcin (132 aa) and showed 65% sequence identity with the goose eggshell protein compared to 41% with chicken eggshell ovocleidin-17. Furthermore, as ansocalcin and unlike ovocleidin-17, it contained an additional, seventh, cysteine that was, however, located close to the C-terminus of SCA-1 and not in the N-terminal third of the sequence as in ansocalcin. SCA-2 showed features of both ansocalcin and chicken eggshell ovocleidin-17 (OC-17). Its sequence was 46% identical to that of ansocalcin and 36% identical to OC-17. It contained the same stretches of negatively charged amino acids conserved in ansocalcin and SCA-1, which are absent in OC-17. On the other hand, its length of 142 amino acids was identical to that of OC-17 and it contained only the usual set of six cysteines conserved in most C-type lectin-like proteins. The presence of three phosphorylated serines located at exactly the same region of the sequence as the two phosphoserines of OC-17 further stressed the similarity between SCA-2 and OC-17.

Localization of osteopontin in oviduct tissue and eggshell during different stages of the avian egg laying cycle

The avian eggshell is an acellular bioceramic containing organic and inorganic phases that are sequentially assembled during the time the egg moves along the oviduct. As it has been demonstrated in other mineralized tissues, mineralization of the eggshell is regulated by extracellular matrix proteins especially the anionic side chains of proteoglycans. Among them, osteopontin has been found in the avian eggshell and oviduct. However, its precise localization in the eggshell or in different oviduct regions during eggshell formation, nor its function have been established. By using anti-osteopontin antibody (OPN 1), we studied its immunolocalization in the isthmus, red isthmus and shell gland of the oviduct, and in the eggshell during formation. In the eggshell, osteopontin was localized in the core of the non-mineralized shell membrane fibers, in the base of the mammillae and in the outermost part of the palisade. In the oviduct, OPN 1 was localized in the ciliated epithelial but not in the tubular gland cells of the isthmus, in the ciliated epithelial cells of the red isthmus, and in the non-ciliated epithelial cells of the shell gland. The occurrence of osteopontin in each of the oviduct regions, coincided with the concomitant presence of the egg in such region. Considering the reported inhibitory function of osteopontin in other mineralized systems, together with its main occurrence in the non-mineralized parts of the eggshell and at the outermost part of the shell, suggests that this molecule could be part of the mechanism regulating the eggshell calcification.

Fatty tissue breast lesions

Hamartoma, lipoma and fat necrosis are benign fatty tissue lesions that may present as breast lumps. The mammographic appearance may be distinctive allowing imaging diagnosis without biopsy. The characteristic feature of hamartoma is that of a compressible mass containing radiolucent fat interchanged with dense fibrous connective tissue surrounded by a thin radioopaque pseudocapsule. Lipomas are radiolucent with well-defined thin smooth capsule. Twenty-seven percent of fat necrosis appears as discrete round or oval radiolucent oil cyst with thin capsule and egg-shell calcification.

Purification of Ovocalyxin-32, a Novel Chicken Eggshell Matrix Protein

The eggshell is a highly ordered structure resulting from the deposition of calcium carbonate and an organic matrix from the acellular uterine fluid. Characterization of the individual matrix components is necessary to determine their influence upon calcite crystal shape, size, and orientation during eggshell calcification. We have purified and sequenced a novel 32-kDa protein, ovocalyxin-32 (OCX-32), which is present at high levels in the uterine fluid during the terminal phase of eggshell formation, and is localized predominantly in the outer eggshell. Database searches identified expressed sequence tags (ESTs) whose alignment yielded the complete cDNA. OCX-32 protein possesses limited identity (32%) to two unrelated proteins: latexin, a carboxypeptidase inhibitor expressed in rat cerebral cortex and mast cells, and to a skin protein that is encoded by a retinoic acid receptor-responsive gene, TIG1. The timing of OCX-32 secretion into the uterine fluid suggests that it may play a role in the termination of mineral deposition.

Purification, Characterization, and in VitroMineralization Studies of a Novel Goose Eggshell Matrix Protein, Ansocalcin

Biomineralization is an important process in which hard tissues are generated through mineral deposition, often assisted by biomacromolecules. Eggshells, because of their rapid formation via mineralization, are chosen as a model for understanding the fundamentals of biomineralization. This report discusses purification and characterization of various proteins and peptides from goose eggshell matrix. A novel 15-kDa protein (ansocalcin) was extracted from the eggshell matrix, purified, and identified and its role in mineralization evaluated using in vitro crystal growth experiments. The complete amino acid sequence of ansocalcin showed high homology to ovocleidin-17, a chicken eggshell protein, and to C-type lectins from snake venom. The amino acid sequence of ansocalcin was characterized by the presence of acidic and basic amino acid multiplets. In vitro crystallization experiments showed that ansocalcin induced pits on the rhombohedral faces at lower concentrations (<50 microg/ml). At higher concentrations, the nucleation of calcite crystal aggregates was observed. Molecular weight determinations by size exclusion chromatography and sodium dodecyl sulfate -polyacrylamide gel electrophoresis showed reversible concentration-dependent aggregation of ansocalcin in solution. We propose that such aggregated structures may act as a template for the nucleation of calcite crystal aggregates. Similar aggregation of calcite crystals was also observed when crystallizations were performed in the presence of whole goose eggshell extract. These results show that ansocalcin plays a significant role in goose eggshell calcification.

Mechanical strain regulation of the chicken glypican-4 gene expression in the avian eggshell gland.

Comparison of RNA fingerprinting of the avian eggshell gland (ESG) without and with an egg revealed upregulation of a 382-bp cDNA fragment that showed high homology to the mammalian glypican 4 (GPC-4). The gene sequence revealed a conserved glypican signature, a glycosyl phosphatidyl inositol-anchorage site, and cystein residues, most of which were conserved. GPC-4 was expressed in the ESG in a circadian fashion only during the period of eggshell calcification, when maximal mechanical strain was imposed. Removal of the egg just before to its entry into the ESG, with consequent elimination of the mechanical strain, caused reduction in the gene expression. Artificial application of the mechanical strain induced expression of the GPC-4 gene that was related to the level of the strain. GPC-4 expression was strain dependent in other parts of the oviduct. In the ESG, GPC-4 was expressed exclusively by the glandular epithelium and not by the pseudostratified epithelium facing the lumen. In summary, we cloned the avian homologue of GPC-4, established its pattern of expression in the avian ESG, and demonstrated for the first time that this gene is regulated by mechanical strain.