Pearl Formation Research Articles

Anatomy of the clitoris: the corona of the glans clitoris, clitoral coronal papillae, and the coronopreputial frenulum.

The corona of the glans clitoris is a clinically important yet poorly understood anatomical structure. There has been longstanding confusion regarding the prevalence of the corona of the glans clitoris and, moreover, its very existence. Therefore, this anatomical study assesses the prevalence of the corona of the glans clitoris and the gross anatomy of the proximal glans clitoris. Anatomy was assessed in 104 female donor bodies ranging in age from 50 to 102 years with an average age-at-death of 78.1±10.9 years (mean±SD). All clitorises (100%; 104:104 dorsums and 100%; 208:208 sides) were found to have a well-defined clitoral corona. Three of 104 (2.9%) coronas possessed grossly visible, outward-projecting, bluntly rounded papillae. Some donors possessed a coronopreputial frenulum. Clitoropreputial adhesions were common and associated with clitoral pearls. Clitoral pearls were identified in 37.8% (14:37) of unembalmed donors and observed to create clitoral craters, structural deformations in the surface of the corona and glans. The results of this study suggest that the corona of the glans clitoris is a ubiquitous anatomical structure. The clitoral coronal papillae and coronopreputial frenulum are novel, previously undescribed, anatomical structures. This study identifies that the corona of the glans clitoris is prone to pathological processes such as clitoral pearl formation and clitoral deformation. In addition to novel anatomical findings, the results of this study call attention to the need for life-long clitoral examinations. Furthermore, the corona of the glans clitoris should be regularly included in anatomical texts and accurately depicted in anatomical illustrations.

Influence of geographical origin and shell positions on nacre color and thickness in mabé pearl oysters Pteria penguin

To examine variations in nacre color and thickness in Pteria penguin oysters obtained from Tonga and Japan, a novel approach with a focus on their potential for mabé pearl production was used. Detailed analyses of color and microstructure revealed that the middle position of the right-valve nacre (position 1) primarily showed a reduction in yellow pigmentation. This was indicated by a decrease in the yellowness index (YI) and an increase in the whiteness index (WI). In contrast, the anterior and middle positions of the left-valve nacre (positions 2 and 3) consistently displayed a higher level of yellow pigmentation. A comparison of oysters from different geographical origin found that Tonga wild-caught oysters had significantly thicker nacre than Tonga culture-site oysters, suggesting the influence of probable genetic diversity and environmental factors on nacre formation. Notably, nacre at position 1 was generally thinner, while at positions 2 and 3 it was thicker, which would influence the resultant pearl quality and attributes. We demonstrate the significance of the nacre position on the valve for mabé pearl production: position 1 tended to produce white pearls with pronounced interference colors, whereas position 2 tended to yield gold pearls. Furthermore, our findings highlight the significant impact of the oysters' geographic origin on mabé pearl color and quality. This study emphasizes the importance of considering the position of shell nacre and the potential influences of the oysters' genetic origins and environmental factors on mabé pearl formation.

Gingival squamous cell carcinoma in 2 lions under managed care.

Neoplasia is one of the main causes of euthanasia in geriatric captive nondomestic felids. However, few studies have examined oral tumors in these animals. We describe here the clinicopathologic features of gingival squamous cell carcinoma (SCC) in 2 lions (Panthera leo) from separate zoologic collections. In both cases, the lions had a history of sialorrhea, bloody oral discharge, and anorexia. Autopsy findings in both lions were similar and were characterized by poorly circumscribed, friable, and bloody gingival masses with grossly apparent invasion of the mandibular bone; a pathologic fracture was observed in 1 case. Histologically, the masses consisted of poorly circumscribed, unencapsulated, densely cellular proliferations of neoplastic epithelial cells arranged in irregular islands, cords, and anastomosing trabeculae with formation of keratin pearls, which, coupled with positive immunohistochemistry for pancytokeratin, were diagnostic for SCC. Although no metastases were found in either animal, both lions were ultimately euthanized because of poor prognosis.

A Comparative Study of Button Hole Technique Versus Underlay Technique in Type 1 Tympanoplasty.

Tympanoplasty is the most common operation performed by an Otolaryngologist worldwide.Type 1 tympanoplasty involves repair of pars tensa of tympanic membrane, when the middle ear is normal. The most widely used method is underlay technique using temporalis facia. In buttonhole tympanoplasty, the temporalis fascia is anchored to the handle of malleus through the buttonhole. To compare and analyze graft uptake and hearing outcome in button hole technique and underlay technique. It is a comparative study done at tertiary care center, where patients suffering from tubotympanic type of chronic otitis media with medium sized perforation with moderate conductive hearing loss, within age group of 18-60 years,were selected. In Button hole tympanoplasty group the mean hearing gain was 9.3dB, and 8.17 dB in Underlay tympanoplasty group which was statistically significant (p < 0.05) but P value between Button hole and Underlay tympanoplasty was not statistically significant.With regard to graft uptake 96.7% showed graft uptake in Buttonhole tympanoplasty group and in underlay tympanoplasty the graft uptake was 93.3%. Buttonhole technique is better in terms of graft uptake since the graft is anchored to the handle of malleus, and postoperatively medialisation of graft and other complications like lateralization of graft, epithelial pearl formation and anterior blunting is prevented. Both techniques are good in terms of hearing improvement for chronic otitis media with medium sized perforation with moderateconductive hearing loss.

Expression of bone morphogenetic protein 10 and its role in biomineralization in Hyriopsis cumingii

Shells and pearls are the products of biomineralization of shellfish after ingesting external mineral ions. Bone morphogenetic proteins (BMPs) play a role in a variety of biological function, and the genes that encode them, are considered important shell-forming genes in mollusks and are associated with shell and pearl formation, embryonic development, and other functions, but bone morphogenetic protein 10 (BMP10) is poorly understood in Hyriopsis cumingii. In this study, we cloned Hc-BMP10 and obtained a 2477 bp full-length sequence encoding 460 amino acids with a conserved TGF-β structural domain. During the embryonic developmental stages, the cleavage stage had the highest expression of Hc-BMP10, followed by juvenile clams; the expression in the mantle gradually decreased with increasing mussel age. A strong signal was detected on epidermal cells on the mantle edge by in situ hybridization. In both the shell notching and inserting operations of the pearl fragment assay, we found that the expression of Hc-BMP10 increased after the above treatments. RNA interference assays showed that the silencing of Hc-BMP10 resulted in a change in the morphology of the prismatic layer and nacreous layer, with the prismatic layer less closely aligned and the disordered aragonite flakes in the nacreous layer. These findings indicate that Hc-BMP10 is involved in the growth and development of H. cumingii, as well as the formation of shells and pearls. Therefore, this study provides some reference for selecting superior species for growth and pearl breeding of H. cumingii at a molecular level and further investigation of the molecular mechanism for biomineralization of Hc-BMP10.

Effect of elevated temperature, sea water acidification, and phenanthrene on the expression of genes involved in the shell and pearl formation of economic pearl oyster (Pinctada radiata)

Our study aims to examine the effect of some stressors on the gene expression levels of shell matrix proteins in a pearl oyster. Oysters were exposed to the different combinations of the temperature, pH, and phenanthrene concentration is currently measured in the Persian Gulf and the predicted ocean warming and acidification for 28 days. The expression of all the studied genes was significantly downregulated. Time and temperature had the greatest effects on the decreases in n19 and n16 genes expression, respectively. Aspein and msi60 genes expression were highly influenced by pH. Pearlin was affected by double interaction temperature and phenanthrene. Moreover, a correlation was observed among the expression levels of studied genes. This study represents basic data on the relationship between mRNA transcription genes involved in the shell and pearl formation and climate changes in pollutant presence conditions and acclimatizing mechanism of the oyster to the future scenario as well.

The regulatory effect of NF-κB signaling pathway on biomineralization and shell regeneration in pearl oyster, Pinctada fucata

Pinctada fucata is an important pearl production shellfish in aquaculture. The formation of shells and pearls is a hot research topic in biomineralization, and matrix proteins secreted by the mantle tissues play the key role in this process. However, upstream regulatory mechanisms of transcription factors on the matrix protein genes remain unclear. Previous studies have shown that NF-κB signaling pathway regulated biomineralization process through expression regulation of specific matrix proteins, including Nacrein, Prismalin-14 and MSI60. In this study, we systematically investigated the regulatory effect of the NF-κB signaling pathway key factor Pf-Rel and inhibitory protein poI-κB on the biomineralization and shell regeneration process. We applied RNA interference and antibody injection assays to study in vivo function of transcription factor Pf-Rel and characterized shell morphology changes using scanning electron microscopy and Raman spectroscopy. We found that transcription factor Pf-Rel plays a positive regulatory role in the growth regulation of the prismatic and nacreous layers, while the function of inhibitory protein poI-κB is to prevent excessive growth and accumulation of both layers. RNA-seq was conducted based on RNA interference animal model to identify potential regulatory genes by transcription factor Pf-Rel. Shell damage repair experiments were performed to simulate shell regeneration process, and observations of newly formed shells revealed that NF-κB signaling pathway had different functions at different times. This study provides us with a more macroscopic perspective based on transcription factors to investigate biomineralization and shell regeneration.

Patho-morphological and Immunohistochemical Studies on Bovine Horn Core Carcinoma

Background: An investigation was carried out on twelve clinical cases of neoplasm of horn in Durg, Dhamtari and Rajnandgaon districts of Chhattisgarh, suspected of bovine horn core carcinoma (squamous cell carcinoma) revealed the cytology, pathomorphology and immunohistochemical (IHC) expression of Pan-cytokeratin (Pan- CK), p53 gene, epidermal growth factor receptor (EGFR) and p16 gene in tumourous growth at horn in bovines. Methods: In this field-laboratory investigation conducted during January to June 2022, we explicate the cytological, pathological and immunohistochemical alterations in bovine horn core carcinoma from 12 tissue samples. Cytological studies includes special papaniculaou staining and immunohistochemistry was performed through Benchmark automated staining system. Result: Eight out of 12 cases (66.66%) were confirmed as SCC of horn on the basis of histopathological and immunohistochemical analysis. Papanicolaou staining revealed variation in shape and size of cells and altered nuclear details. Grossly unilateral large cauliflower like neoplastic growth at the base of the horn was observed. Differentiation of tumours were based on histopathology and Immunohistochemistry. Well differentiated SCCs (n=4; 50%) were characterized by severe keratinization of horn epithelium with concentric arrangement forming keratin pearls also called as “cell nests”. Moderately differentiated SCCs (n=2; 25%) characterized by small keratin pearl formations and mitotic figures. Poorly differentiated SCCs of horn (n=2; 25%) revealed absence of distinctive keratin pearls although deep invasion from primary site was observed. Tissue samples revealed strong immunohistochemical staining of Pan-CK, p53 and EGFR and negative to p16. Highest immunohistochemical expression was observed in Pan-CK which confirmed the tumours were of epithelial origin and EGFR immunoexpression was confirmatory for malignancy and degree of metastasis.

Molecular confirmation of pearl formation in arctic mussels (Mytilus edulis) caused by Gymnophallus bursicola (Odhner 1900) metacercariae.

In recent field studies, suspected gymnophallid metacercariae were histologically located in the mantle of mussels from the Norwegian Sea. Mussels from the sites in which that infection was detected also presented abnormally high pearl numbers. It has been previously described that gymnophallid metacercariae could cause pearl formation processes in mussels, as a host reaction to encapsulate these metacercariae. Given the pathological host reaction these parasites elicit, a study was performed to identify gymnophallid metacercariae found in mussels collected from Tromsø at morphological and molecular level and to assess, by the use of molecular tools, the relationship between the parasite and the biological material inside the pearls. As a result, Gymnophallus bursicola metacercariae infecting Norwegian Mytilus edulis were identified according to morphological characters, along with the first 18S rDNA and COI sequences for this trematode species. In addition, parasite DNA from the core of the pearls was extracted and amplified for the first time, confirming the parasitological origin of these pearls. This procedure could allow identifying different parasitic organisms responsible for the generation of pearls in bivalves.

Pearl shape classification using deep convolutional neural networks from Tahitian pearl rotation in Pinctada margaritifera

Tahitian pearls, artificially cultivated from the black-lipped pearl oyster Pinctada margaritifera, are renowned for their unique color and large size, making the pearl industry vital for the French Polynesian economy. Understanding the mechanisms of pearl formation is essential for enabling quality and sustainable production. In this paper, we explore the process of pearl formation by studying pearl rotation. Here we show, using a deep convolutional neural network, a direct link between the rotation of the pearl during its formation in the oyster and its final shape. We propose a new method for non-invasive pearl monitoring and a model for predicting the final shape of the pearl from rotation data with 81.9% accuracy. These novel resources provide a fresh perspective to study and enhance our comprehension of the overall mechanism of pearl formation, with potential long-term applications for improving pearl production and quality control in the industry.

RECURRING AMELOBLASTOM INJURY IN THE ANTERIOR REGION OF JAW

An 86-year-old female patient complained of a lesion in the anterior region of the mandible with five previous surgical procedures and recurrences in all of them. Clinical examination revealed a hardened consistency, firm to palpation and normochromic color. Computed tomography showed a multilocular hypodense lesion with cortical bone destruction. The histopathological analysis showed a neoplastic lesion of odontogenic origin, characterized by the proliferation of epithelial cells grouped in a follicular pattern, and a peripheral palisade with nuclei exhibiting inverted polarity in the center of these enamel islands. The centers of these islands often show squamous metaplasia with the formation of keratin pearls, characterizing an acanthomatous pattern. The diagnosis of Ameloblastoma was established. The patient is awaiting surgical excision of the lesion. An 86-year-old female patient complained of a lesion in the anterior region of the mandible with five previous surgical procedures and recurrences in all of them. Clinical examination revealed a hardened consistency, firm to palpation and normochromic color. Computed tomography showed a multilocular hypodense lesion with cortical bone destruction. The histopathological analysis showed a neoplastic lesion of odontogenic origin, characterized by the proliferation of epithelial cells grouped in a follicular pattern, and a peripheral palisade with nuclei exhibiting inverted polarity in the center of these enamel islands. The centers of these islands often show squamous metaplasia with the formation of keratin pearls, characterizing an acanthomatous pattern. The diagnosis of Ameloblastoma was established. The patient is awaiting surgical excision of the lesion.

The Puzzle of the Thinly Coated Pearl

This article takes animal materials as contested elements of ecological knowledge production. The focus is on Ago Bay, a Japanese inlet at the mid-twentieth-century global epicenter of demand for “cultured” pearls that formed inside surgically manipulated shellfish. In 1950s Ago, long-established pearl cultivators complained that their pearls had thinner outer coatings than they expected. Tracing shifting ideas about shellfish stocking densities, smallholder aquaculture, rates of pearl formation, and the accumulation of organic wastes in water over time, this article reconsiders the puzzle of the thinly coated pearl. In its guise as host to thousands of working pearl farms and a network of researchers studying the effects of intensive pearl cultivation, Ago Bay is a rich site from which to think about aquaculture’s ecological and infrastructural limits. The bay was not simply a natural receptacle that housed pearl cultivation. The shore, water, seafloor, and floating pearl oyster raft-and-cage systems could be—and were—defined as infrastructure that could undergo regulation and rearrangement. Pearl cultivation did not just happen in the bay; it was part of the bay—and it reshaped ideas about the bay. This paper is part of a special issue entitled “Making Animal Materials in Time,” edited by Laurence Douny and Lisa Onaga.

(135) Keratin Pearl Excision for Clitorodynia and Female Sexual Dysfunction

Abstract Introduction Clitoral adhesions occur when the clitoral prepuce adheres to the glans clitoris. This can cause accumulation of desquamated epithelial cells under the prepuce, resulting in the formation of smegmatic pseudocysts and keratin pearls. A keratin pearl is a focus of central keratinization within concentric layers of squamous cells. Presence of these firm, millimeter-sized masses can lead to clitoral irritation and hypersensitivity (similar to a grain of sand in the eye). Although keratin pearls have been described in the literature, there is little known about their clinical presentation or association with female sexual dysfunction (FSD). Objective Investigate the effectiveness of keratin pearl excision as a treatment for clitoral pain and female sexual dysfunction. Methods A retrospective chart review was conducted in two metropolitan gynecology clinics specializing in vulvar pain between January 2017 and December 2021. Patients presenting with clitoral pain (clitorodynia) were identified in the electronic medical record through a search of physician-entered diagnoses and confirmed via review of the clinical notes. Adult patients with documented clitoral pain as well as clitoral adhesions (clitoral phimosis) and keratin pearls noted on exam were included in the study. Female Sexual Dysfunction (FSD) was measured with the Female Sexual Function Index (FSFI) and Female Sexual Distress Scale-Revised (FSDS-R). Prospective data was collected via an electronic follow-up survey. Data were presented in means and percentages. Results Fifty-eight patients met inclusion criteria. Average age at presentation was 35 years (range 19-73 years). Self-reported ethnicity of the study population was 81% White, 7% Hispanic, 5% Asian, 2% Black, with no response from 5% of participants. Preliminary results show that patients reported a 66% decrease in mean clitoral discomfort (p &amp;lt; 0.0001) and a 52% reduction in mean difficulty with orgasm (p = 0.019) after excision of keratin pearls. Patients who completed the follow-up questionnaire (n = 18) had a mean FSFI total score of 18.3 compared to mean total baseline FSFI of 13.11 (p = 0.03). The mean FSFI score for pain was 2.85 at follow up compared to 1.52 at baseline (p = 0.01). The mean FSFI score for orgasm was 3.36 at follow up compared to 2.16 at baseline (p = 0.03). Although not statistically significant, most likely because of a small sample size, the mean FSFI score was higher at follow-up than at baseline for lubrication (45%), arousal (42%), satisfaction (19%), and desire (17%). Patients had no change in mean FSD-R score from baseline to follow up. Conclusions Clitorodynia associated with clitoral adhesions and keratin pearls occurs in women of all ages. Excising keratin pearls may reduce female sexual dysfunction. These preliminary results suggest that excising keratin pearls may improve clitoral discomfort and reduce difficulty with orgasm. Excising keratin pearls may also lead to an improvement in overall female sexual function. Disclosure No

Disordered dolomite as an unusual biomineralization product found in the center of a natural Cassis pearl.

Natural pearls are produced without human intervention, mainly due to various irritations from the surrounding environment to their mantle tissues. Pearls usually possess similar mineral compositions to the host shells, which means they are also dominated by aragonite and calcite. In this study, we report a natural pearl from a Cassis species mollusk containing granular central structures. Raman spectroscopy, laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS), energy dispersive X-ray spectroscopy (EDS) coupled with scanning electron microscope (SEM), and X-ray diffraction (XRD) analyses were carried out in order to characterize the mineral composition in the center region of this pearl. Our results showed that this pearl's center was made of mostly disordered dolomite (Ca0.53Mg0.47CO3) mixing with small amount of aragonite and high magnesium-calcite. To the best of our knowledge, this is the first time disordered dolomite was conclusively identified inside of a natural pearl and such information expanded our knowledge on internal growth structures and formation of natural pearls.

Droplet entrapment on inclined substrates by enforcement of pearl formation

Sliding droplets on an inclined substrate may deposit a residual liquid termed as pearling. This three-dimensional mechanism can be observed even on near-perfect surfaces, and it is mainly affected by the Bond number, inclination angle, and capillary number. However, specifically designed surfaces can alter the dynamic contact line and enforce droplets to deposit a pearl. We model three-dimensional droplet motion under long-wave assumption with a precursor film model for such substrates where the surface is designed as a continuous function and integrate governing equations using quadratic finite element method with adaptive mesh refinement. For various surface structures, energies, and inclination angles, we show the expedition/promotion of pearl formation alongside its mechanism, and how to periodically trap droplets inside the grooves. Finally, we discuss the volume control of entrapped droplets.

Exploration of the Mechanism and Process of Pearl Formation

Exploration of the Mechanism and Process of Pearl Formation

A Squamous Cell Carcinoma Presenting as a Giant Cutaneous Horn over the Lower Lip in a Patient with Chronic Disseminated Lupus Erythematosus.

A Squamous Cell Carcinoma Presenting as a Giant Cutaneous Horn over the Lower Lip in a Patient with Chronic Disseminated Lupus Erythematosus.

Utilization of artificial intelligence-assisted histopathological detection in surveillance of oral squamous cell carcinoma staging: A narrative review

Background: Oral squamous cell carcinoma (OSCC) is defined as an oral malignancy with worldwide prevalence of 90%. In 2018, the number of cases observed is 354.864 with 177.384 deaths globally. Early diagnosis for determining OSCC stage due to histopathological examination is required to sustain prognosis and minimize mortality. Determining the stage is mostly done manually and highly dependent on skill and experiences of the pathologist thus having a high tendency of misdiagnosis. Artificial intelligence (AI) is a technology that modifies machines with human-like intelligence thus making them able to solve the tasks. Utilization of AI in analyzing histopathological samples is known to give such a precision analysis then diagnosing the OSCC stage accurately Purpose: This study describes utilization of AI-assisted histopathological detection in determining OSCC staging. Review: Developmental process of OSCC begins with gene damage causing disruption of cell regulation, manifesting in impaired differentiation and proliferation of keratinocytes in the epithelium which is characterized by keratin pearl formation. AI-assisted histopathological detection is able to identify the percentage of keratinization and keratin pearls in histopathological images by convolutional neural network (CNN). CNN is a deep learning architecture specifically designed to recognize two-dimensional visual patterns with minimal preprocessing. CNN works by analyzing input in the form of visual images from histopathological images and producing output as keratinization percentage in related samples then being used to determine the staging of OSCC. Conclusion: AI-assisted histopathological detection may potential to be used in determining OSCC staging.

Pearl formation associated with gymnophallid metacercariae in Mytilus galloprovincialis from the Northwestern Adriatic coast: Preliminary observations

Gymnophallids of the genus Parvatrema are small trematodes infecting waterbirds in their adult stage. Several species of clams and mussels have been found to act as first and second intermediate hosts, in which the trematode larval stages induce the formation of pearls. In this study, a wild population of Mytilus galloprovincialis was sampled along the Northwestern coast of the Adriatic Sea to evaluate the origin and extent of visible pearls. Parasitological investigations, including morphological and molecular analyses, and histopathology were carried out on a representative sample of mussels (n = 158) from June to September 2021. The overall prevalence of infection reached 75.3 %, and the intensity of infection ranged from a few trematodes to thousands per mussel, mostly occurring in the mantle and surrounded by variable numbers of conchiolin layers. Morphological studies allowed classification of the metacercariae as belonging to the genus Parvatrema, and the pairwise comparison of the obtained sequences, encompassing the internal transcribed spacer (ITS) region, revealed a genetic similarity (96.8 %) to Parvatrema duboisi. However, the phylogenetic analysis demonstrated the independent clustering of the obtained ITS sequences compared to other available Parvatrema species. For the relevant commercial impact that pearl formation may have on farmed mussels, ecological and epidemiological aspects of this infection would deserve further investigation in the area.

Study of the influence of the parameters of preparation of polymeric solutions obtaining nanofibers by electrospinning

The technique of electrospinning polymeric nanofibers has been emerging in the academic environment due to its well-parias and low operational, but the production of these nanofibers finds challenges regarding homogeneity and reproduction of obtained results. As properties of polymeric solutions are important for the determination of electrospinning parameters, such as the applied electrical voltage and injection rate. Seeking rheological behavior of polymeric solutions; which may be affected by the concentration of the polymeric solution and the preparation temperature of these solutions. This way this work studied the effect of the production temperature of polyacrylonitrile and methyl acrylate copolymer solutions and related them to the nanofibers produced at the same injection rates and electrical stresses. It was observed the inversely proportional behavior between the temperature of preparation of the solutions and the viscosity of the solutions at room temperature, which reflects in the integrity and homogeneity of the fibers formed, with the formation of pearls in the nanofibers produced to more viscous solutions.&#x0D;