Molecular identification, phylogenetic analysis and histopathological study of pathogenic free-living amoebae isolated from discus fish (Symphysodon aequifasciatus) in Iran: 2020-2022

Free-living amoebae (FLA) are capable of inhabiting diverse reservoirs independently, without relying on a host organism, hence their designation as "free-living". The majority of amoebae that infect freshwater or marine fish are amphizoic, or free-living forms that may colonize fish under particular circumstances. Symphysodon aequifasciatus, commonly referred to as the discus, is widely recognized as a popular ornamental fish species. The primary objective of the present study was to determine the presence of pathogenic free-living amoebae (FLA) in samples of discus fish. Fish exhibiting clinical signs, sourced from various fish farms, were transferred to the ornamental fish clinic. The skin, gills, and intestinal mucosa of the fish were collected and subjected to culturing on plates containing a 1% non-nutrient agar medium. The detection of FLA was conducted through morphological, histopathological and molecular methods. The construction of the phylogenetic tree for Acanthamoeba genotypes was achieved using the maximum likelihood approach. The molecular sequence analysis revealed that all cultures that tested positive for FLA were T4 genotype of Acanthamoeba and Acanthamoeba sp. The examination of gill samples using histopathological methods demonstrated the presence of lamellar epithelial hyperplasia, significant fusion of secondary lamellae, and infiltration of inflammatory cells. A multitude of cysts, varying in shape from circular to elliptical, were observed within the gills. The occurrence of interlamellar vesicles and amoeboid organisms could be observed within the epithelial tissue of the gills. In the current study, presence of the Acanthamoeba T4 genotype on the skin and gills of discus fish exhibiting signs of illness in freshwater ornamental fish farms was identified. This observation suggests the potential of a transmission of amoebic infection from ornamental fish to humans, thereby highlighting the need for further investigation into this infection among ornamental fish maintained as pets, as well as individuals who interact with them and their environment.

Mechanical removal of epithelial hyperplasia leads to successful treatment of irregular astigmatism

BACKGROUND

Corneal epithelium remodeling in response to changes in the anterior corneal surface (keratoconus, corneal refractive surgery) is well-documented in the literature. However, several conditions may induce a different behavior of the epithelium, in which focal areas of epithelial thickening induce irregular astigmatism. This case report presents a highly unusual case of irregular astigmatism induced by an epithelial hyperplasia of unknown etiology, which was treated by the mechanical removal of only the epithelium.

CASE PRESENTATION

A 29-year-old woman underwent implantable collamer lens implantation to correct myopia. The patient provided written informed consent. The procedure was uneventful in both eyes. Twenty months later, she complained of decreased visual acuity in the left eye (uncorrected distance visual acuity (UCDVA) was 20/30; corrected distance visual acuity was 20/20 with + 1.00 -2.25 × 170). Corneal topography revealed a nasal steepening in the left eye. Although the corneal thickness map was normal, epithelial thickness mapping revealed a localized nasal area of epithelial hyperplasia in the left eye that matched the area of steepest curvature. Slit lamp examination showed a total clear cornea with no signs of abnormality. The patient´s medical history was unremarkable and a case of epithelial hyperplasia of unknown etiology, without active inflammation, was considered. The decision was made to perform a mechanical removal of the corneal epithelium after application of diluted alcohol. One month after the procedure, the topography of the epithelized cornea showed a regular bow tie pattern and UCDVA improved to 20/20. No recurrence of the epithelial hyperplasia was detected after twenty-one months.

CONCLUSIONS

Focal epithelial hyperplasia may induce irregular astigmatism. Epithelial thickness mapping is a very helpful technological tool to assess cases with irregular topography. De-epithelization as an isolated procedure may be useful for the successful management of these cases. Further research is required to understand the mechanism that triggers the spontaneous development of a focal epithelial hyperplasia.

Vocal-fold leukoplakia and dysplasia. Mini-review by the French Society of Phoniatrics and Laryngology (SFPL)

Vocal-fold leukoplakia and dysplasia are together designated "epithelial hyperplastic laryngeal lesions" (EHLL). Work-up and follow-up are founded on optical examination with high-definition imaging, stroboscopy and narrow-band imaging. Diagnosis is based on pathology, using the new 2017 WHO classification, dichotomizing "low grade" and "high grade". Statistically, the risk of cancerous progression is 20% within 5 to 10 years of diagnosis, or more in over-65 year-old males; risk for any given patient, however, is unpredictable. Research focuses on the genetic criteria of the lesion and characterization of the tumoral microenvironment. Treatment is exclusively microsurgical. Resection depth is adjusted according to infiltration. EHLL is a chronic disease, necessitating long-term follow-up, which may be hampered by residual dysphonia and surgical sequelae in the vocal folds. Sequelae need to be minimized by good mastery of microsurgical technique and indications. When they occur, biomaterials such as autologous fat and hyaluronic acid can be useful. Tissue bio-engineering is a promising field.

The molecular-based differentiation of Heck's disease from its mimics including oral condyloma and white sponge nevus

Heck's disease (focal or multifocal epithelial hyperplasia) is a benign, rare condition of the skin and mucous membranes induced by human papillomavirus (HPV) infection. Other entities that can induce large papillomatous lesions that involve the mucous membranes and skin include condyloma acuminatum, which is sexually transmitted, and white sponge nevus, often due to a mutation of cytokeratin 4 or 13. Six cases diagnosed as either Heck's disease (n = 2) or white sponge nevus (n = 4) and 6 oral condyloma were compared on histologic grounds and analyzed in situ for HPV DNA, including HPVs 6,11, and 13, as well as cytokeratins 4 and 13. Each case showed marked acanthosis, and para/hyperkeratosis. More variable histologic findings included rete ridge elongation, keratinocyte degeneration, and perinuclear halos. High copy HPV 13 DNA was evident in the squamous cells towards the surface in the two cases diagnosed as Heck's disease and in two cases diagnosed as white sponge nevus on clinical grounds. HPV 6/11 was found in each of the six condyloma. Marked decrease in either cytokeratin 4 or 13 was evident in the two cases diagnosed as white sponge nevus that were HPV DNA negative. It is concluded that in situ hybridization analyses including HPVs 6, 11, and 13 as well as immunohistochemistry for cytokeratins 4 and 13 can differentiate Heck's disease from condyloma and white sponge nevus, which can be difficult to differentiate on clinical and histologic grounds.

Cyclosporine A - Induced gingival overgrowth and proliferating cell nuclear antigen expression in experimental periodontitis

The most important microscopic characteristic of Cyclosporine A-induced gingival overgrowth is fibroepithelial hyperplasia.

OBJECTIVE

The objective was to investigate the influence of previous exposure to Cyclosporine A over gingival epithelium in experimental periodontitis in rats.

METHODS

Twenty Wistar rats with 12 weeks-old were divided into four groups with 5 animals each: Control Group (CG); Cyclosporine Group (CsAG); Ligature group (LG) and Cyclosporine and Ligature Group (CsALG). Daily doses of CsA (10 mg/kg) were applied to CsAG and CsALG during 60 days since the beginning of the experiment and, a ligature was placed in LG and CsALG 30 days after the beginning of the experiment. After 60 days, animals were euthanized and gingival tissue was processed to histomorphometric analysis of epithelial thickness (mm²), immunohistochemical expression of PCNA (%) and inflammatory response. Data were analyzed by Kruskal-Wallis and Mann Whitney at 0.05 significance level.

RESULTS

Considering epithelial thickness, CG was thinner than all groups, CsALG was the largest and CsAG and LG were similar between each other. Regarding the PCNA expression CG (16.46 ± 9.26) was similar to CsAG (34.47 ± 19.75) and, LG (59.02 ± 10.33) was similar to CsALG (40.59 ± 18.25). Significant difference (p < 0.05) occurred only in inflammation presence comparing CG/LG and CsAG/CsALG. A weak positive correlation between the number of PCNA+ and inflammatory cells (p = 0.001; r = 0.611) was observed.

CONCLUSION

Based on these results it was concluded that the enlargement of gingival epithelium observed in experimental periodontitis can be increased by previous exposition to CsA and inflammatory conditions enhanced proliferative activity of the keratinocytes.

Synchronous Occurrence of Primary Cutaneous Anaplastic Large Cell Lymphoma and Squamous Cell Carcinoma

CD30+ lymphoproliferative disorders (LPD) represent a spectrum of T-cell lymphoma including lymphomatoid papulosis and anaplastic large cell lymphoma (ALCL). Epidermis overlying cutaneous CD30+ LPD often shows epidermal hyperplasia, hyperkeratosis, crusting, and ulceration and it is difficult to distinguish from carcinoma such as keratoacanthoma (KA) or squamous cell carcinoma (SCC). Several cases of pseudocarcinomatous hyperplasia mimicking KA or SCC in CD30+ LPD have been reported. The relationship between CD30+ LPD and epithelial proliferations has not yet well understood. It was reported that a variety of mediators, including epidermal growth factor (EGF), transforming growth factor-α and EGFR from CD30+ LPD could attribute to epidermal hyperplasia. However, separate and distinct SCC occurring in CD30+ LPD has rarely been reported. Herein, we present a rare case of coexistence of SCC and cutaneous ALCL located on the same region.

Glomerular epithelial cell phenotype in diffuse mesangial sclerosis: a report of 2 cases with markedly increased urinary podocyte excretion

We report 2 cases of diffuse mesangial sclerosis (DMS) accompanied by severe podocyte excretion in urine. Patient 1 was a 9-day-old girl with a WT1 mutation who developed Wilms tumor at 6 months of age and was subsequently diagnosed with Denys-Drash syndrome. Patient 2 was a 1-year-old boy without a WT1 abnormality but presenting with heavy proteinuria. In both patients, histological examination showed findings of DMS. Immunohistochemical staining for synaptopodin (a podocyte marker) revealed a reduced number of podocytes in the glomeruli with severe sclerosis; however, podocytes persisted in the relatively intact glomeruli. Some glomeruli were accompanied by sclerotic lesions surrounded by proliferating cells; immunofluorescence staining revealed a majority of these proliferating cells to be positive for claudin-1 (a parietal cell marker) but negative for synaptopodin. These findings suggest that podocyte loss and the consequent proliferation of parietal cells are common processes in the pathogenesis of DMS.