Calcified Granules Research Articles

Roles of entrapped bubbles in methanogenic granules under oscillating pressure: Respiration and embolization for intra-granular transport

Anaerobic granular sludge plays a pivotal role in the treatment of concentrated organic wastewater. However, previous studies on intra- granular transport have generally overlooked lung-like respiration that expedites transport in response to fluctuating pressure. This study explored the activities of calcified and normal granules under simulated hydrostatic pressure oscillations. The results revealed a significant enhancement in the bioactivity of calcified granules under oscillating pressure, contrasting with the comparatively lower bioactivity observed in normal granules. The hypothesis posited that the gas pockets in calcified granules facilitated respiration as the functional structure. The presence of tiny bubbles exhibited a propensity for inducing clogging, thereby diminishing the capillary connectivity essential for substrate diffusion. The proposed respiration and embolization concepts decipher the distinct roles of entrapped bubbles in the granular bioactivity across diverse fluid states. This study offers valuable insights into the impact of fluidization on microscopic transport within granule-based bed reactors.

Calcium migration inside anaerobic granular sludge: Evidence from calcium carbonate precipitation pattern

Calcification of anaerobic granule sludge caused the decrease of reactor deactivation has been focused in paper industry for decades, the mechanism of calcium immigration is still in curiosity. In this study, evidences relevant to the calcium immigration involving surface adherence, crystallite size and precipitation pattern were analyzed in a calcified granule. Crystal larger than 2 µm would be sterically stuck in the channel and calcium transfer occurred through serial deposition and resolution. Ca2+ diffusion in the confined channel through Ostwald ripening was in consisted with the Liesegang rings pattern. Thus, a hypothetical mechanism of calcium migration was proposed used to understand the calcium-precipitation control strategy in granule-based anaerobic reactor. The findings of this study are referable for the regulation of mineral precipitation during granule-based wastewater treatment system.

Mineral Trioxide Aggregate (MTA) Upregulates the Expression of DMP1 in Direct Pulp Capping in the Rat Molar.

Mineral trioxide aggregate (MTA) is an alternative endodontic material that predicts conductive or inductive calcified tissue formation from immature pulp mesenchymal stem cells (IPMSCs). The purpose of this study was to investigate whether MTA could promote reparative odontoblast differentiation via IPMSCs in the early phase of regeneration and compare with calcium hydroxide (CH). Direct pulp capping using calcium hydroxide (CH), MTA, and MTA with platelet-rich plasma (MTA + PRP) was performed on maxillary first molars of 8-week-old male Wistar rats (n = 36). After 3, 7, or 14 days, the teeth were analyzed for mineral density (MD) and volume of MD (VMD) via micro-focusing computed tomography (µCT), nestin, dentin matrix acidic phosphoprotein 1 (DMP1) immunohistochemistry, and real-time PCR for DMP1 mRNA expression. MTA stimulated the early phase differentiation of the IPMSCs into odontoblasts, with positive results for nestin and DMP1 compared with CH. Moreover, MTA + PRP stimulated calcified granule and dentin bridge formation through calcium mineral deposition, following the induction of DMP1 mRNA expression in IPMSCs. Our results suggested that the combination of MTA and PRP is an effective and clinically applicable method for activating endogenous dental pulp stem cells into odontoblasts in the early stages of pulp regeneration.

Deciphering the formation of sludge blanket structure in anaerobic granular systems from the perspective of bubble-entrapment assumption

Granular sludge is the basic unit of anaerobic granular systems, and the hydrodynamics of the sludge blanket is significantly governed by the granule characteristics. Although trapped bubble was one of the reasons to trigger granule floatation, until now, consensus has not been reached about the impact of bubble-entrapment on granule behavior and their spatial distribution in granular system. Besides, anaerobic granular sludge subjected to calcium-rich wastewater usually faced serious operational problems, leading to granule deactivation and sludge bed cementation. Bubble entrapment and calcium precipitation in granule change particle characteristics in opposite ways. In this study, a bubble entrapment model was proposed to infer the granule floatability based on the force balance between bubble-induced buoyancy and calcium precipitation-induced gravity. The results of the stratified sludge bed characterization conducted in two full-scale anaerobic reactors clearly present their diversified granule features in the vertical direction. The result shows that the lower boundary density for calcified granule was 1.10 × 103 kg/m3 and the most dynamic granules had a density ranged from 1.10 to 1.20 × 103 kg/m3. The comparative analysis of AnGS fluidization behavior and spatial distribution confirmed the reliability of the probabilistic prediction model of theoretical granule interception. Overall, these results contribute to an educated assumption into the understanding of the impact of granule density variation caused by biogas production and calcification on the formation of stratified sludge bed structure in anaerobic granular system.

Uncover the secret of granule calcification and deactivation in up-flow anaerobic sludge bed (UASB) reactor with long-term exposure to high calcium

Calcification of anaerobic granular sludge causing the decrease of microbial activity has been focused for several decades, but the mechanism of calcification and deactivation of calcified granule are still lacking. In this study, the calcification process of anaerobic granular sludge was analyzed in the UASB reactor with long-term exposure to a high calcium level of 2 gCa2+L−1. Greyish-white calcified granules with larger size and density first appeared at the bottom of sludge bed. Characterization of granular surface demonstrated that calcified granules had smaller specific surface area and pore volume with the disappearing channels in granules visualized over calcification. The coverage of calcite on granular surface with a thickness of 500–600 µm was observed by a microscope, which is responsible for the blockage of channels for substrate diffusion and transport. The evaluation of mass transfer showed that the ‘effectiveness factor’ η of calcified granules was higher than 1.23, proving the existence of mass transfer resistance. Furthermore, the interactions between calcium and extracellular polymeric substances (EPS) revealed the possible mechanism of calcite location at the outer layer of anaerobic granular sludge: The bulk calcite directly binds the EPS such as humic acids via charging functional groups, and bulk CO32− could react easily with Ca2+ bound to EPS according to thermodynamic analysis.

Endoscopic Diagnosis of Calcifying Fibrous Tumor of the Ileum

CASE REPORT A 47-year-old woman was admitted to our hospital with right lower abdominal pain persisting over 2 months. She was a nondrinker and a never-smoker, and she'd had an appendectomy 23 years previously. Except for right lower abdominal pain, no remarkable findings were recognized on physical examination. Blood tests were also unremarkable. The cause of abdominal pain could not be determined by ordinary physical and laboratory examinations, so we performed a lower gastrointestinal (GI) endoscopy. It revealed a submucosal tumor (20 mm) at the terminal ileum (Figure 1). The tumor was smooth and spherical, and it showed no surface ulceration or hemorrhage, suggesting that it was not highly malignant. Cushion sign was negative, and lipoma was ruled out. Endoscopic ultrasonography (EUS) showed foci of calcification in the tumor (Figure 2). Image resolution of the thin EUS probe was not sufficient to observe in detail, but the origin of the tumor appeared to be the fourth layer, namely, the muscular layer. Whole-body computed tomography (CT) found no other neoplastic lesions. CT images showed that the ileal tumor was a mass lesion with coarse calcification. The characteristic calcification of the tumor led to a diagnosis of probable calcifying fibrous tumor (CFT). Physicians recommended surgical removal because of persistent pain and the small possibility of it being a GI stromal tumor (GIST) that might present calcification.Figure 1.: Lower gastrointestinal endoscopy showing a spherical submucosal tumor in the terminal ileum.Figure 2.: Endoscopic ultrasound revealing granular calcification in the tumor (arrows).The tumor was removed with ileocecal resection. The resected tumor was elastic and well-circumscribed, and its cut surface was off-white in color (Figure 3). Histologically, it consisted a combination of abundant hyalinized collagen and sparse spindle cells (Figure 4). Scattered psammoma bodylike calcified granules were seen in the tumor. These histopathological features were consistent with reported CFT.1-4 The patient's postoperative course was uneventful, and no recurrent tumors have been reported.Figure 3.: Cut surface of the surgical specimen showing an off-white submucosal tumor.Figure 4.: Microscopic slide (hematoxylin and eosin) showing that the tumor consisted mainly of abundant hyalinized collagen and contains calcified granules (arrows).CFT is a rare benign mesenchymal neoplasm, which arises in various organs and tissues including the GI tract.1-3 Most intestinal tumors are detected incidentally during abdominal surgical procedures for disorders other than CFT.2-4 Despite their entirely benign biological nature, surgical removal is recommended for intestinal CFTs because they may cause critical GI complications, such as ileus and intussusception.2-4 If possible, endoscopic resection may be of enormous benefit for patients.2 As this case shows, EUS provides important information to make the correct preoperative diagnosis of CFT. Distinguishing CFT from calcified GIST is crucial in the diagnosis of CFT, although the calcifying patterns of GIST (patchy or marginal) are considerably different from that of CFT (granular).5 DISCLOSURES Author contributions: All authors contributed equally to the writing and editing of this manuscript. Y. Ikura is the article guarantor.

Multiple-level ossification of the ligamentum flavum in the cervical spine combined with calcification of the cervical ligamentum flavum and posterior atlanto-axial membrane

Ossification of the ligamentum flavum (OLF) is rarely identified in cervical spine and its pathogenesis has not been established. We report a case of multiple-level OLF, combined with the calcification of the cervical ligamentum flavum and posterior atlanto-axial membrane. A 42-year-old man without any systemic background presented with one month history of pain from the neck to the right shoulder and right leg numbness. Cervical computed tomography demonstrated OLF from C2 to C5, a small area of calcification of the ligamentum flavum (CLF) from C5/6 to C7/T1 and extensive calcification of the posterior atlanto-axial membrane, resulting in spinal canal stenosis. Magnetic resonance imaging showed spinal canal stenosis and severe spinal cord compression from C2 to C5. Thoracic X-ray also showed ossification of the posterior longitudinal ligament (OPLL). We performed laminectomy from C1 to C5 and resected the calcified posterior atlanto-axial membrane and OLF. Histopathological examination demonstrated calcified granules within degenerated fibrous tissue in the posterior atlanto-axial membrane and mature bony trabeculae, bone marrow and residual ligament tissue in the OLF. Simultaneous development of cervical OLF and CLF in this case seems unlikely to have occurred coincidentally and suggests that the pathogenesis of OLF and CLF may share a common initiation factor.

Nutrition of the Developing Embryo and Hatchling

Nutrient needs central to satisfactory egg incubation well-being undergo several major changes from fertilization until the reliance of the chick on feed. Glucose is central, with the initiation of incubation until the chorioallantois accesses O2 to use for fatty acid oxidation. Nutrient recovery from albumen and yolk is largely commensurate with body assembly through to completion of the embryo by 14 d. Remaining albumen mixes with the amniotic fluid and is orally consumed until initiation of emergence. A portion of the albumen is absorbed by the small intestine to expand body glycogen reserves. The residual not absorbed contains digestive enzyme contributions and enters the yolk sac through its stalk at the jejunum and ileum. Interaction of the albumen-amnion digestive enzyme mixture with yolk sac contents leads to diverse alterations that influence subsequent use of lipids. Rapid removal of very low-density lipoprotein ensues, until pipping with triglycerides, expanding body fat depots while cholesterol deposits in the liver. A concurrent translocation of Ca from shell mineralizes the skeletal system while also crossing yolk sac villi for deposition on phosvitin-based granules accruing in its lumen. Loss of chorioallantois with pipping and the start of pulmonary respiration predispose a dependence on glycolysis to support emergence. Small intestinal villi progressively reorient their enterocytes from macromolecule transfer to competence at digestion and absorption after hatching. Mobilization of body fat complements contributions from the yolk sac to provide fatty acids for generating energy, heat, and water while also combining with hepatic cholesterol for membrane expansion and continued development. Calcified granules evacuate the yolk sac to further skeletal mineralization in the absence of shell contributions. Egg mass, its interior quality, and turning during early incubation directly influence the ability of the embryo to access nutrients and provide resources to support emergence and the transition of the chick to self-sufficiency.

骨形成を伴ったＷａｒｔｈｉｎ腫瘍の１例

We report a rare case of Warthin tumor accompanied by bone formation. A 57-year-old woman with pus discharge in the right mandibular gingiva visited our hospital in August 1995. Several fistulas in the right mandibular gingiva and a rough-surfaced tumor 1.5 cm in diameter on the right side of the tongue were found. The clinical diagnosis was osteomyelitis of the mandible and tongue cancer. Sequestrotomy of the mandible and partial glossectomy were performed in October 1995. At that time, a computed tomographic (CT) scan showed 1-cm-diameter lesion in the right parotid gland; however, she hesitated to undergo surgery. In April 2001, a CT scan revealed a bilateral mass 1.2 cm in diameter near the parotid glands, and the mass in the right parotid gland increased to 2 cm in diameter and possessed a small calcified granule inside. 99mTc scintigraphy of the salivary glands showed a hot spot in the both parotid glands, consistent with the tumor. In March 2002, she underwent extirpation of the tumors arising in the both parotid glands. Histopathological examination showed a typical Warthin tumor appearance, with bone formation in the hyalinized structure of the tumor. At present, the patient has no evidence of disease.

Selective calcification of rat brain lesions caused by systemic administration of kainic acid.

Dystrophic calcification of previously damaged areas of nervous tissue occurs in a wide range of human diseases. The relationship between astroglial and microglial reactions and deposits of calcium salts was studied for up to five months in rats with a brain lesion produced by systemic administration of kainate. The morphology and atomic composition of the calcium salt deposits was also studied. Two types of lesions, sclerotic and liquefactive, were observed. In sclerotic lesions hyperplasia and hypertrophy of astrocytes partially substituted for the lost neurons, reaching a maximum in about twenty-five days after treatment. In liquefactive lesions, the astrocytic reaction occurred only around the liquefactive area. Microglial reaction was similar in both types of lesion and reached its highest expression in about twenty-five days. Calcium deposits were observed in the sclerotic but not in the liquefactive lesions. Clearly distinguishable granules of calcium salts were observed in sclerotic lesions under scanning electron microscopy after only five days post-injection. The size of calcified granules increased with time reaching 40 micro m or more in diameter at five months. The atomic composition of these deposits, studied by X-ray microanalysis, showed a time-dependent increase in calcium concentration. While there was no clear relationship between astroglial and microglial reactions and calcium salt deposits, the systemic injection of kainate produced progressively larger and more concentrated calcium deposits in sclerotic, but not in liquefactive lesions.

Microscopic structure of the mantle and palps in the freshwater mussels velesunio ambiguus and hyridella depressa (Bivalvia: Hyriidae)

There has been increasing interest in freshwater mussels (order Unionoida) in recent years because their numbers are declining in many parts of the world and also because they have potential as monitors of pollution. Most studies have been performed on the families Unionidae and Margaritiferidae from North America and Europe, and comparatively little is known of the Hyriidae from Australasia. The present study describes the microscopic structure of tissues in the mantle and palps of two hyriid mussels, namely Velesunio ambiguus and Hyridella depressa, as viewed by light and electron microscopy. The two mussels show similarities with the unionids and margaritiferids, particularly the presence of extracellular mineralised granules. The mantle and palps of V. ambiguus and H. depressa consist of flaps of tissue bordered on the inner and outer surfaces by simple epithelia. The intervening tissue is dominated by connective tissue containing vesicular cells, muscle, nerves and blood spaces with haemocytes. Orange–yellow extracellular calcified granules are a prominent feature of the interstitial tissues. The abundance of calcified granules in the mantle of H. depressa is greater than that in V. ambiguus and there are differences in the appearance of the apical vesicles in epithelial cells.

Calcification of Experimental Valve Bioprostheses

Bovine pericardial strips, porcine valve strips, and canine valve strips were treated with 0.625% glutaraldehyde and implanted subdermally in rats. Weight and calcium content were examined 9 weeks later. Bovine pericardial strips underwent calcification after implantation; electron microscopy showed concentric electron-dense calcified deposits in the collagen fibers. Implanted porcine valve strips also underwent calcification; electron microscopy showed concentric electron-dense calcified deposits in the interstitium. Calcification was also detected in canine valve strips after implantation, but the proportion of calcium was lower than in the other tissues; electron microscopy showed collagen bundles with speckled calcified granules. The process of calcification started on the surface of the collagen fibrils and in the interfibrillar space. It was concluded that preservation of collagen fibers would be helpful in preventing calcification. The use of canine cardiac valves might improve the durability of bioprostheses.

Ultrastructural study of direct bone formation induced by BMPs-collagen complex implanted into an ectopic site.

Some authors have reported that direct bone formation is ectopically induced by bone morphogenetic proteins (BMPs) independently of cartilage formation when type I collagen is used as a carrier. This study ultrastructurally investigated the mechanism of direct bone formation by BMPs-collagen complex. Partially purified BMPs were combined with atelopeptide type I collagen (AC) and were implanted into the calf muscles of rats (n = 20). Tissue specimens were removed on days 7, 10, 14, and 21 after implantation. Ultrastructurally, several regions near the pellet rim showed evidence of early calcification on day 10. In the uncalcified regions, mitochondrial calcification was seen in mesenchymal cells near AC fibers. The initially calcified regions contained numerous calcified granules deposited in the AC fibers. Some of these granules adhered to the cell membrane of osteogenic cells. In the highly calcified regions, some osteogenic cells secreted uncalcified matrix and deposited needle-like crystals and calcified collagen microfibrils on the AC fibers. This study suggests that the mesenchymal cells invading BMPs-AC complex closely contacted the AC fibers, differentiated into osteogenic cells, and deposited calcified matrix on the AC fibers, resulting in direct osteoinduction without cartilage formation.

Oxalosis and Pigmentation in Aspergillosis of the Maxillary Sinus

The fungus ball of aspergillosis in the maxillary sinus -with calcification and brown pigmentation was investigated by means of histopathologically, histochemically and electron probe microanalytically. The central area of the mass was composed of necrotized tissues containing brown pigments and calcified granules while in the peripheral region septate fungal hyphae and conidial heads resembling Aspergillus nigar were observed. The calcified granules were manifested as calcium oxalate histopathologically and did not contain phosphorous but calcium suggesting also calcium oxalate electron probe microanalytically.

The fine structure and development of calcified skeletal elements in the body wall of holothurian echinoderms.

The calcareous ossicles and iron-rich calcified granules in the integument of sea cucumbers (Echinodermata: Holothuroida) have been examined by light and electron microscopy. Most ossicles are perforated, platelike structures that measure 100-500 μm long and consist of magnesium-rich calcite. The formation of ossicles occurs within multinucleated syncytia of sclerocytes that are situated in the dermal layer of the body wall. Sclerocytes possess fairly large numbers of mitochondria and are characteristically enveloped by an external lamina. Each ossicle arises as a minute rodlike spicule that branches and develops into a fenestrated skeletal element. When viewed by SEM, fully developed ossicles appear non-crystalline. Following decoration with synthetically grown calcite seeds, however, each ossicle reveals an ordered array of crystallites that seem to be aligned perpendicular to the ossicle's original plane of growth. Examinations of sectioned ossicles indicate that the mineral phase in each skeletal element lacks a well developed matrix of EDTA-insoluble organic substances. Ossicles first arise in the ciliated, lecithotrophic larvae of Eupentacta quinquesimita at about 1 week postfertilization. Two-week-old specimens adopt an epibenthic existence and subsequently become enveloped by imbricated ossicles that are secreted by sclerocytes resembling those found in adults. In molpadiid holothurians, the adult body wall contains numerous reddish-brown granules that are chiefly composed of iron-rich subunits. The dermal granules differ from calcitic ossicles in developing extracellularly in association with finely filamentous material.

Specific metal binding sites on calcified concretions in epithelial cells of the clam kidney

Calcified granules (concretions) in the kidneys of bivalve molluscs are able to absorb metals from solution and this ability is the result of the existence of saturable, medium affinity metal binding sites on the concretions. In addition different metals may compete for the same sites so that some metals will be accumulated preferentially over others.

Experimental coxsackie B-3 virus myocarditis in golden hamsters. Light and electron microscopy findings in a long-term follow-up study.

Following intraperitoneal inoculation with coxsackie B3 virus all weaning Syrian golden hamsters (60 animals) developed severe myocarditis. In the acute phase, light and electron microscopy revealed massive cellular infiltration and myocytolysis in the myocardium which were most prominent on the 5th day and least obvious in 3 weeks. In the necrotic myocytes, mitochondria contained moderately electron dense inclusions different from the calcified granules seen in the myocardium of mice with coxsackie B3 virus myocarditis. Macrophages ingested and digested necrotic cell debris, leaving moderate fibrosis but no calcification in the myocardium. Viruses were isolated from the myocardium on the 3rd to 9th day, and virus particles were seen in a necrotic cardiocyte on the 9th day. In the chronic phase, most animals developed no cardiomegaly; light microscopy revealed minimal myocardial fibrosis; electron microscopy showed various degenerative changes in some cardiocytes. A few animals (two animals) developed significant cardiomegaly with moderate to marked myocardial fibrosis in the 6th and 14th month. In one heart there was marked biventricular dilatation. In these animals with cardiomegaly, ultrastructural changes of the myocardial cells were similar to those described in congestive cardiomyopathy in man. Golden hamsters appear to be a unique model for a study of the possible relationship between viral myocarditis and idiopathic cardiomyopathy in man.

Carbonic anhydrase and mobilisation of calcium reserves in the mantle of lamellibranchs.

A study of the mechanism of exchange regulation between the different calcium pools in freshwater lamellibranch mantle shows: 1) that the substances concerned in this regulation, namely the calcium reserves and carbonic anhydrase, must be topographically in close proximity, 2) that the calcium reserves occur as small extracellular calcified granules localised in the interstitial tissue of the mantle (evidence both from experiments on homogenates and from histological examination), and 3) that observations on the sedimentation in mantle homogenates suggest that the enzyme is bound to the calcified granules. The role of such an enzyme-substrate unit is discussed.

I.—On the Structure of the Frontal Spine and the Rostrolabial Cartilages of Squaloraja and Chimæra

The remarkable frontal spine of Squaloraja has always been described as a dermal structure by those who have referred to it, and has been classed with the shagreen-granules and dentition. After the systematic position of the genus had been determined, its frontal spine was rightly recognized as identical with the spine-like frontal process in Chimæra and fossil Holocephala, with which it was formerly compared by W. Davies and A. S. Woodward. Both these processes were regarded as dermal structures by von Zittel, Jaekel, and A. S. Woodward, and treated as true ichthyodorulites, i.e. as if consisting of dentine or vasodentine. In 1890 the present writer briefly pointed out that the frontal spine of the Jurassic Chimæroid, Ischyodus avita, consisted of extremely calcified fibro-cartilage, resembling that of the so-called “claspers” of all male Elasmobranchs. The microscopical structure of these parts differs conspicuously from that of the calcified granules in the common (hyaline) cartilage of the internal skeleton, and its ontogenetic development is different.