Liesegang Research Articles

Kinetics of the formation of Liesegang rings

The kinetics of the formation of Liesegang rings is considered and they are classified. The relationship between the position of the propagating diffusion front and the moments of the formation of Liesegang rings is shown. In order to describe the formation processes of the Liesegang rings a generalized model based on the diffusion equation hierarchy is proposed. The kinetics of changes in the dispersed phase sizes at the initial stage of the formation of Liesegang rings is studied.

Liesegang Rings in Apocrine Cysts of the Breast

Liesegang Rings in Apocrine Cysts of the Breast

Studies on Liesegang rings of copper molybdate in agar gel medium

The present work deals with the studies on Liesegang ring formation of copper molybdate ions using copper sulphate as an outer electrolyte and sodium molybdate as an inner electrolyte. For this purpose 1% agar gel was used and the inner electrolyte concentration was chosen to be 0.025M and 0.05M. While outer electrolyte concentration was kept 0.5M and 0.25M. Morphological characteristics of Liesegang rings such as size of the ring, number of rings per day, and spacing between rings were studied. The concentration of reacting ions in the ring was estimated by atomic absorption spectrophotometer. The obtained results are quantitatively explained on the basis of spacing law, time law and width law. All basic laws were obeyed successfully by the system. It was observed that, the morphological characteristics of the rings were affected by the concentrations of inner and outer electrolytes.

Calcifying Epithelial Odontogenic Tumor

The calcifying epithelial odontogenic tumor (CEOT) is a rare benign epithelial odontogenic neoplasm of slow growth that is locally aggressive and tends to invade bone and adjacent soft tissue. Here is reported the case of a 21-year-old female patient with a CEOT in the left mandibular posterior region. The computerized tomography in coronal plane revealed a hypodense lesion in the posterior region of the left mandibular body with hyperdense areas inside and was associated with element 37. An incisional biopsy of the lesion was performed and the histopathological analysis revealed the presence of layers of epithelial odontogenic cells that formed prominent intercellular bridges. A large quantity of extracellular, eosinophilic, and amyloid-like material and an occasional formation of concentric calcifications (Liesegang rings) were also found. The histopathological diagnosis was a Pindborg tumor. Resection of the tumor with a safety margin was performed and after 6 months of follow-up there has been no sign of recurrence of the lesion.

Non-calcifying variant of calcifying epithelial odontogenic tumor with clear cells-first case report of an extraosseous (Peripheral) presentation

AbstractCalcifying epithelial odontogenic tumor or Pindborg tumor is a rare benign odontogenic tumor that was first described by a Danish pathologist Jens Jorgen Pindborg in 1955. It is thought to arise from the epithelial element of the enamel origin and is histologically characterized by the presence of polygonal epithelial cells, amyloid globules, and Liesegang ring calcifications. A few cases have been shown to demonstrate clear cells (Langerhans cells) in the tumor. Non-calcifying epithelial odontogenic tumor (NCEOT) s very rare and only four cases have been documented in the English Language Literature to date. All these cases were present intraosseously (central). We present the first case of an extraosseous (peripheral) NCEOT with clear cells (Langerhans cells) and briefly discuss as well as review the histogenesis along with the differences in its clinicopathological and prognostic profile with respect to other variants.

3D laser ablation-ICP-mass spectrometry mapping for the study of surface layer phenomena – a case study for weathered glass

In this work, a multi-elemental 3D laser ablation-ICP-mass spectrometry mapping procedure for high-resolution depth information retrieval to investigate surface layer phenomena is presented. The procedure is based on laser drilling on a virtual grid on the surface, followed by extraction of depth maps along the z-axis (for each element monitored). Using a burst of 50 laser pulses at 1 Hz on each point of the grid, a penetration rate of ca. 150 nm per pulse (in glass) was obtained and a lateral resolution in the order of the laser beam diameter. By ultrafast ICP-MS monitoring of individual ablation pulses (58 ms for a set of 19 elements) using a laser ablation cell with fast signal washout (less than 0.5 s for whole laser pulse), the corresponding peak areas could be consistently integrated, resulting in spatial elemental data associated with individual pulses. The usual laser drilling limitations such as pulse mixing and signal tailing are avoided with this approach. After manipulation of the spatial elemental datasets and quantification, stacks of 50 2D depth maps (for each element monitored) were produced which could be visualized as volume images or time-lapse movies. As a proof of concept, this approach was successfully used to investigate the degradation mechanisms of a medieval, weathered glass artifact by colocalization analysis of selected cross-sectional 2D elemental images in arbitrary planes of the volume images. It was shown that degradation must have started as a result of dealkalinization leading to depletion of alkalis/earth alkalis in glass surface layers and enrichment of network formers (Si and Al), and subsequent worsening by cracking and formation of corrosion pits and so-called spatiotemporal Liesegang rings indicative of radial leaching.

Liesegang rings of dendritic silver crystals emerging from galvanic displacement reaction in a liquid-phase solution

Liesegang rings (LR) of various types of Ag dendrite crystals are observed from an aqueous solution based on a simple galvanic displacement reaction between a Zn plate and Ag2SO4. The growth process and formation mechanism of LR of Ag dendrites are investigated in detail. The synthesised LR of Ag dendrites have been successfully employed as a Raman probe for SERS analysis of melamine.

Pindborg Tumor: Review of Literature and Case Reports

Pindborg or calcifying epithelial odontogenic tumor (CEOT) is a benign and noninvasive tumor that presents poor clinical features, a typical radiological picture and a characteristic histomorphology. CEOT is an uncommon odontogenic neoplasm, representing only 1% of all odontogenic tumors. The average age of occurrence is around 40 years with almost 1:1 gender ratio. It shows a mandible:maxilla site ratio of 2:1 and is mainly located in the molar:premolar (3:1) region. The tumor usually appears as a radiolucent area containing radiopaque masses scattered throughout. Histologically, it is characterized by densely eosinophilic cells, which tend to calcify, homogeneous eosinophilic substance believed to be amyloid and calcifications in concentric layers (Liesegang rings). Two case reports are presented here in patients aged 30 years and 14 years

Bone lid technique to enucleate bilateral mandibular pindborg tumour

Calcifying epithelial odontogenic tumour (Pindborg tumour) is a rare benign neoplasm. It is an uncommon and locally invasive benign odontogenic tumor. The most characteristic findings are the presence of amyloid-like substance and calcified concentric liesegang rings. We report an unusual case of multifocal CEOT. A 24-year-old female presented with bilateral soft, erythematous, gingival swellings localized in posterior maxilla and mandible. Radiographic findings revealed that extended radiopaque regions related impacted teeth.

Liesegang ring formation during the supramolecular hydrogelation of the chiral drug methocarbamol

The chiral drug methocarbamol, which is prone to spontaneous resolution, is an effective molecular hydrogelator as both an enantiomer and a racemate; the samples of methocarbamol having an intermediate enantiomeric composition generate clearly visible periodic structures (Liesegang rings) during the gelation process.

Medial artery calcification of uremic patients: a histological, histochemical and ultrastructural study.

Recent findings suggest that vascular calcification (VC) is an active process similar to bone mineralization, the vascular smooth muscle cells (VSMCs) undergoing phenotypic differentiation into osteoblastic cells and synthesizing calcification-regulating proteins found in bone. This study has investigated the VC process of uremic patients, with a morphologic approach. Epigastric artery samples from 49 uremic, non-diabetic patients were taken during kidney transplantation. Sections from paraffin-embedded samples were stained with hematoxylin/eosin and von Kossa. CD68 was immunohistochemically detected, and sections from frozen samples were stained with Oil Red O. Deeply calcified samples were stained with Picrosirius Red, PAS, and Alcian blue. Specimens from one patient with moderate and one with severe VC were examined under the electron microscope. None of the samples had atherosclerosis. Calcifications were found in the media of 38 patients. In 23, dot-like calcifications were irregularly scattered near the adventitia (light VC); in 11, granular calcifications formed concentric rings near the adventitia (moderate-advanced VC); in 4, zones of consolidated calcifications were found (severe VC). These zones were poor in collagen, glycoproteins and proteoglycans. In cases with moderate or severe VC, VSCMs showed necrotic changes. Matrix vesicles could be recognized in the extracellular spaces. In cases with severe VC, uncalcified or partially calcified membranous bodies were found, together with Liesegang rings. Patches of fibrin were also found. These findings point to a mainly degenerative mechanism of VC, which proceeds from the outer portion of the media. An active mechanism, however, cannot be excluded. A unifying hypothesis is suggested.

Growth and characterization of Struvite‐K crystals

AbstractStruvite‐K is the natural potassium equivalent to Struvite. Struvite‐K crystals were grown by single diffusion gel growth technique in silica hydro gel medium. Struvite‐K crystals with different morphologies having transparent to translucent diaphaneity were grown with different growth parameters. The phenomenon of Liesegang rings was also observed with some particular growth parameters. The crystals were characterized by powder XRD, FT‐IR, TGA and dielectric study. The powder XRD results of Struvite‐K confirmed the orthorhombic crystal structure. The FT‐IR spectrum proved the presence of water of hydration, metal – oxygen bond and P – O bond. The TGA, DSC and DTA were carried out simultaneously. It was found that crystals started dehydrating and decomposing from 75 °C and finally at 600 °C temperature it became 64.14% of the original weight and remained almost constant up to the end of analysis. From the thermo‐gravimetry, the numbers of the water molecules associated with the crystal were calculated and found to be 5. The kinetic and thermodynamic parameters of dehydration / decomposition process were calculated. The variation of dielectric constant with frequency of applied field was studied in the range from 400 Hz to 100 kHz, which exhibited the decreasing nature of the dielectric constant as frequency increased. The dielectric study showed that a.c. conductivity increased and consequently the a.c. resistivity decreased with the increase in frequency. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Preliminary Study of Quantitative Analysis of Ammonium Ions in a Raindrop Following Liesegang Ring Formation

NH(4)(+) concentration in an individual droplet was determined by forming a Liesegang ring on a gelatin film containing NaB(C(6)H(5))(4). The NH(4)(+) concentration (mol L(-1) abbreviated to M) was calculated from the NH(4)(+) amount (mol) ascertained in a droplet using pixel count measurements. The droplet volume (L) was calculated by measurement of the diameter of a droplet print on the gelatin film. For rainwater, the NH(4)(+) concentration estimated using this method corresponded with results obtained using ion chromatography.

Formation of Concentric Multilayers in a Chitosan Hydrogel Inspired by Liesegang Ring Phenomena

Liesegang rings, periodical bands or ring patterns formed by inorganic precipitation in polymer gel medium, have attracted lots of interest of researchers aiming to construct ordered structures. Inspired by the Liesegang ring phenomena, chitosan, instead of inorganic species, was used as building block to construct a chitosan hydrogel with concentric multilayers in a protonated chitosan/NaOH reaction system by alternate soaking in NaOH solution and water. The morphology of concentric multilayers structure was characterized by environmental scanning electron microscopy. The upload and release behavior of isoniazid was also investigated. The quantitive rules of the concentric layer position/the square root of reaction time and the position of the consecutive concentric layer coincide with the time law and space law of the classical Liesegang ring phenomena, respectively. The chitosan solution converts into a hydrogel accompanied by remarkable volume shrinkage due to hydrogen bonds reconstruction and electrostatic repulsion disappearance. The separated concentric multilayers can be formed due to the fluctuation of hydroxide ions concentration when the neutralization is interrupted by alternate soaking in NaOH solution and water. The major difference of the concentric multilayers in chitosan hydrogel from the classical Liesegang ring phenomena occurring in inorganic precipitation systems is that chitosan not only plays the role of reactant in chitosan hydrogel formation, but also acts as supporting reaction medium to control the diffusion behavior of hydroxide ions. The porosity and equilibrium swelling ratio of the chitosan xerogel are 63% and 1100%, respectively, which is feasible for drug uploading through diffusion or absorption. The isoniazid release kinetics are dominated by the diffusion–erosion model. The chitosan hydrogel with concentric multilayers structure loaded with isoniazid will have wide applications in treatment of bone tuberculosis.

Co-expression of BMP-2 and -7 in the Tumoral Epithelium of CEOT with Selective BMP-7 Expression in Amyloid Materials

The calcifying epithelial odontogenic tumor (CEOT) is a benign but locally-invasive odontogenic neoplasm believed to take origin from the stratum intermedium of the developing tooth germ. Bone morphogenetic proteins (BMPs) are multifunctional signaling molecules that regulate diverse cellular processes including epithelial-mesenchymal interactions during odontogenesis. Aberrant BMP activity has been enumerated in the ameloblastoma but information about its distribution in the CEOT remains limited. The aim here was to investigate BMP expression in CEOT and to speculate on its significance. Immunolabelling for BMP-2 and BMP-7 was performed on archival tissues of six CEOT cases and the level of expression was quantified as negative (0), mild (+), moderate (2+) and strong (3+). Results disclosed that CEOT epithelium demonstrated co-expression of BMP-2 and -7 suggesting upregulation of these proteins at sites of tumor differentiation. Distribution patterns were distinct with some overlap. Their localizations were largely membranous and/or cytoplasmic. Amyloid-like materials strongly expressed BMP-7 but were nonreactive for BMP-2, implicating that these signaling proteins play differential roles in the formation of these extracellular products. Mineralized substances including Liesegang rings were mostly negative for both BMPs suggesting that calcification process is associated with repression of these molecules. Stromal endothelium and fibroblasts were stained variably positive. BMP was heterogeneously detected in the CEOT epithelium at the tumor advancing front suggesting their upregulation at active sites and downregulation in quiescent areas. Present findings suggest that BMP-2 and BMP-7 most likely play differential roles in the cellular differentiation and progression of CEOT. BMP-7 accumulation within amyloid-like protein is a novel finding.

Liesegang rings in an apocrine hidrocystoma: a case report and review of literature

Liesegang rings represent an in vivo chemical precipitation phenomenon representing a potential diagnostic pitfall for misdiagnosis as parasitic infections. These acellular patterns of lamellar concretions are rare in human tissue. The authors report a case of Liesegang rings observed within an intradermal apocrine hidrocystoma and review the literature for reports of these structures, with particular emphasis on mucocutaneous lesions.

Liesegang Rings in Paratubal Cysts: Case Report and Literature Review

Liesegang rings (LRs) are laminated precipitation structures well recognized in the field of chemistry. I present a rare case of a 53-year-old female who consulted for pelvic pain and abnormal uterine bleeding. The pelvic ultrasound revealed intramural and submucous uterine leiomyomas, and she underwent hysterectomy and bilateral salpingo-oophorectomy. Gross examination showed several paratubal cysts, which contained multiple eosinophilic concentrically spherical and oval structures of variable size compatible with LRs. In the female genital tract only 8 cases with LRs have been reported. This is the first documented case of LRs appearing in paratubal cysts. LRs formation should be taken into account during the histopathologic examination of paratubal cysts and not be misdiagnosed as a parasitic infection or foreign material within the female genital tract.

Liesegang Rings in Xanthogranulomatous Pyelonephritis: A Case Report

Liesegang rings are concentric noncellular lamellar structures, rarely seen in vivo, occurring as a consequence of the accumulation of insoluble products in a colloidal matrix. These characteristic structures are a rare phenomenon usually found in association with cystic or inflammatory lesions and may be mistaken for parasites. The authors examined Liesegang rings from an inflammatory kidney lesion identified previously as a tumoral lesion on computerized tomography. On microscopic evaluation, Liesegang rings can be mistaken for eggs and larvae of parasites, psammoma bodies and calcification. Special stains like PAS, Grocott, von Kossa and Masson's trichrome facilitate the diagnosis.

Immunohistochemical Study of Notch Signaling Proteins in the Calcifying Epithelial Odontogenic Tumor (Pindborg Tumor)

Notch signaling pathway mediates diverse biological processes including cell fate decisions during odontogenesis. Dysregulation of Notch has been implicated in the tumorigenesis of some odontogenic neoplasms but its role in the calcifying epithelial odontogenic tumor (CEOT) remains unclarified. The aim here was to investigate Notch expression in CEOT and to speculate on its significance. Receptors Notch1-4 and their ligands (Jagged1, Jagged2 and Delta1) were examined immunohistochemically in six CEOT cases. Expression levels were quantified according to the percentage of positive tumor cells, amyloid-like proteins and calcifications: (-), negative staining; (+), mild and focal positivity 50. CEOT epithelium demonstrated variable expression levels for Notch1, 3, 4, Jagged1 and Delta1 suggesting upregulation of these molecules at sites of tumor differentiation. Distribution patterns were distinct with some overlap. Their localizations were largely membranous and/or cytoplasmic. Notch2 and Jagged2 were absent. Amyloid-like materials strongly expressed Jagged1 but variably Notch1, 3 and Delta1 implicating that these signaling proteins maybe competitive substrates with CEOT amyloid-like proteins for proteolysis. Notch2, 4 and Jagged2 were absent. Mineralized substances including Liesegang rings were negative for Notch receptors and ligands suggesting that calcification process is associated with downregulation of these molecules. Stromal endothelium and fibroblasts were stained variably positive. Taken together, current data suggest that Notch receptors and their ligands may play differing roles in the acquisition of cell fates in CEOT. Notch accumulations within amyloid-like protein suggest impaired proteolysis.

Biliary deposition of Liesegang rings presenting as a polypoid mass in the liver: Previously unrecognized lesion

Liesegang rings (LR) are acellular, laminated structures that may be deposited within and around cysts and inflamed or necrotic tissue. Previous reports have shown that the kidney and breast are commonly affected organs of LR. Herein is reported a rare case of biliary deposition of LR presenting as a tumor-like polypoid mass in the liver. A 70-year-old man was found to have a cystic lesion, measuring 3.0 cm in diameter, in the lateral segment of the liver. The lesion was accompanied by a solid mass, 1.8 cm in diameter, within the cystic cavity. Lateral segmentectomy of the liver was performed because clinical examinations could not exclude the possibility of hepatobiliary cystadenoma or cystadenocarcinoma. Pathology of the resected specimen indicated a soft polypoid mass, connecting to the cystically dilated bile duct with elongated stalk-like structures. Histologically the surface of the mass was covered by non-neoplastic biliary-type epithelium. Beneath the epithelium, extensive deposition of numerous ring-like laminated structures, which exhibited an identical appearance to LR, was observed. This is a unique and previously unrecognized lesion involving the occurrence of LR deposition in the hepatobiliary tracts, which further formed a grossly visible mass resembling a hepatic tumor.