Mucispirillum schaedleri: Biofilm Architecture and Age-Dependent Pleomorphy

Round bodies in spirochete cultures have been a controversial subject since their description seven decades ago. We report the existence of round bodies (spherical cells) in cultures of Mucispirillum schaedleri, a spiral bacterium phylogenetically distant from spirochetes. Furthermore, when grown in biofilms, M. schaedleri demonstrates a unique morphology known as cording, which has been previously described only in mycobacteria. Thus, M. schaedleri has two distinct features, each previously thought to be unique to two different phylogenetically distant groups of bacteria.

Fibroblastic osteosarcoma: A perplexing entity

Osteosarcoma (OS), also referred to as osteogenic sarcoma, is the most common primary malignant tumour affecting long bones, characterised by the proliferation of osteoblastic precursor cells and the production of osteoid or immature bone. OSs of the head and neck region have unique biology, exhibiting a clinical behaviour and a natural history that are distinct from OSs of the trunk and extremities. Similarly, their radiological appearance and histological growth pattern can be quite diverse proving to be a challenge to histopathologists to arrive at a diagnosis. Hence, OSs of the jaw remain enigmatic, and a number of difficulties related to their diagnosis and treatment are yet to be resolved. This article reports on a case of advanced OS of the mandible in a 45-year-old woman who came for the evaluation of swelling. This case illustrates the various modalities of diagnosis, such as radiology, histopathology and immunohistochemistry for the confirmation of the variants of OS, leading to an enormously improved quality of life by offering an improved opportunity for cure and treatment.

Pleomorphic undifferentiated sarcoma of the mediastinal thymus: A case report and literature review

Pleomorphic undifferentiated sarcoma (PUS) of the mediastinal thymus is a rare type of cancer. In the present case report, a 67-year-old female patient presenting a mediastinal mass for >1 year was assessed for clinical characteristics, histopathological, immunohistochemical expression and gene mutation using fluorescence in situ hybridization (FISH), and relevant literature was reviewed. Histological analysis revealed nodular changes of different sizes in the thymus, which consisted of a mixture of pleomorphic and spindle cells. The pleomorphic cells with distinct atypia were giant cells and multinucleated cells with large cell sizes and frequent nuclear divisions. The spindle cells were mild to moderate atypical and arranged in a woven pattern, and nuclear division was rare. Immunohistochemical analysis indicated that vimentin was diffusively expressed in tumor cells. No amplification was found in CDX2 and MDM4 genes using the FISH analysis. In conclusion, mediastinal thymus neoplasm should be considered in the presence of PUS and it is an exclusionary diagnosis based on clinical and pathological examination of the patient.

Pituicytoma with pleomorphism: A case report with cytological findings

Pituicytoma is a rare neoplasm, arising in the posterior pituitary or in the hypophyseal stalk, and its cytological findings have not yet been well-described. We have experienced a case of pituicytoma, which was difficult to diagnose intraoperatively, because of its cellular pleomorphism. A tumor measuring 18 mm in maximum diameter was found at the sella turcica in a Japanese woman in her forties. Both intraoperative crush cytology and histology of the resected tumor showed pleomorphic spindle or round cells, including multinucleated cells. Tumor cells were positive for TTF-1, S-100 protein, and vimentin, partially positive for glial fibrillary acidic protein and epithelial membrane antigen, and negative for synaptophysin, hormones of the anterior pituitary gland, CD34, Olig2, PAX8, and napsin A. Ki-67 labeling index was 2.0%. Tumors included in the differential diagnosis in general are pituitary adenoma, craniopharyngioma, germinoma, and metastatic tumor on the radiological standpoint, and pilocytic astrocytoma and meningioma on the cytological standpoint. However, our case was difficult to differentiate especially from high-grade glioma only by morphology, and immunohistochemistry including TTF-1 was helpful.

A Pleomorphic Puzzle: Heterogeneous Pulmonary Vascular Occlusions in Patients with COVID-19

Vascular occlusions in patients with coronavirus diseases 2019 (COVID-19) have been frequently reported in severe outcomes mainly due to a dysregulation of neutrophils mediating neutrophil extracellular trap (NET) formation. Lung specimens from patients with COVID-19 have previously shown a dynamic morphology, categorized into three types of pleomorphic occurrence based on histological findings in this study. These vascular occlusions in lung specimens were also detected using native endogenous fluorescence or NEF in a label-free method. The three types of vascular occlusions exhibit morphology of DNA rich neutrophil elastase (NE) poor (type I), NE rich DNA poor (type II), and DNA and NE rich (type III) cohort of eleven patients with six males and five females. Age and gender have been presented in this study as influencing variables linking the occurrence of several occlusions with pleomorphic contents within a patient specimen and amongst them. This study reports the categorization of pleomorphic occlusions in patients with COVID-19 and the detection of these occlusions in a label-free method utilizing NEF.

High-grade transformation of pancreatic neuroendocrine tumor associated with TP53 mutations: A diagnostic pitfall mimicking neuroendocrine carcinoma

Among pancreatic neuroendocrine neoplasms, mutations in ATRX, DAXX, and MEN1 are specific to neuroendocrine tumors (NETs), whereas TP53 and RB1 mutations are characteristic of neuroendocrine carcinomas (NECs). We report a case of pancreatic NET that underwent high-grade transformation associated with acquisition of TP53 mutations. The primary pancreatic tumor consisted of conventional grade 2 NET with loss of alpha-thalassemia/mental retardation, X-linked expression and wild-type TP53, with a small focus exhibiting significant pleomorphism and increased mitotic activity of the neoplastic cells with two pathogenic TP53 mutations. Two years later, multiple liver metastases developed and were surgically resected. The metastatic tumors showed marked pleomorphism with increased mitotic activity (17/2 mm² ) and TP53 mutations identical to the small area with TP53 mutations in the primary tumor. Liver metastases with a single TP53 mutation were also noted. Notably, hormonal phenotype has changed during progression with decreased glucagon and increased insulin expression in the metastases. Our observations suggest that TP53 mutation can occur in pancreatic NETs during progression and can be associated with phenotypic transformation. Importantly, increased pleomorphism, mitotic activity, as well as TP53 mutations could be diagnostic pitfalls leading to an overdiagnosis of NEC.

Lineages Derived from Cryptococcus neoformans Type Strain H99 Support a Link between the Capacity to Be Pleomorphic and Virulence

The pathogenic yeast Cryptococcus neoformans causes nearly 200,000 deaths annually in immunocompromised individuals. Cryptococcus cells can undergo substantial morphological change during mammalian infection, including increased capsule and cell size, the release of shed capsule, and the production of titan (>10 μm), micro (<2 μm)-, and irregular cells. We examined phenotypic variation under conditions designed to simulate in vivo stress in a collection of nine lineages derived from the C. neoformans type strain H99. These lineages are highly genetically similar but have a range of virulence levels. Strains from hypervirulent lineages had a larger average capsule size, greater variation in cell size, and an increased production of microcells and shed capsule. We tested whether disruption of SGF29, which encodes a component of the SAGA histone acetylation complex that has previously been implicated in the hypervirulence of some lineages, also has a role in the production of morphological variants. Deletion of SGF29 in a lineage with intermediate virulence substantially increased its production of microcells and released capsule, consistent with a switch to hypervirulence. We further examined SGF29 in a set of 52 clinical isolates and found loss-of-function mutations were significantly correlated with patient death. Expansion of a TA repeat in the second intron of SGF29 was positively correlated with cell and capsule size, suggesting it also affects Sgf29 function. This study extends the evidence for a link between pleomorphism and virulence in Cryptococcus, with a likely role for epigenetic mechanisms mediated by SAGA-induced histone acetylation.

Pleomorphic Sarcoma of the Oral Cavity: A Rare Case Entity

Pleomorphic sarcomas are extremely rare in the oral cavity, representing only 5% of all soft tissue sarcomas in the extremities of adults. They form a group of highly undifferentiated pleomorphic malignant tumors. A 36-year-old male reported to the OP with a chief complaint of a tooth ache in the right lower quadrant for the past 6 months. The patient gave a history of extraction of a mobile tooth in that region. A radiograph of the region was advised. An incisional biopsy was also done and sent for histopathological examination. The microscopy revealed the presence of spindle-shaped cells showing dysplastic features. A panel of immunohistochemical markers were performed to identify the tissue of origin of the lesion. The article details the clinical, radiographic, and microscopic features of a pleomorphic soft tissue lesion along with the array of immunohistochemical markers, leading to the final diagnosis of such enigmatic lesions.

The Prognostic Significance of Pleomorphism in Gastrointestinal Stromal Tumors

AIMS

Gastrointestinal stromal tumors (GISTs) typically show uniform nuclear morphology, with spindle cell, epithelioid, or mixed histology. Risk of progression in GIST is estimated based on anatomic site, tumor size, and mitotic index. Pleomorphic GISTs are rare and have not been systemically investigated. We evaluated the prognostic significance of pleomorphism in GIST.

METHODS AND RESULTS

In total, 108 of 2517 (4.3%) GISTs reviewed between 2000-2021 were reported to show pleomorphism. Seventeen cases underwent mutational testing. Pleomorphism was noted prior to therapy in 37 GISTs, affecting 18 males and 19 females with a mean age of 55.4 yrs. Most tumors arose in the stomach (n=15) or small intestine (n=19), with a mean size of 9.2 cm and a median mitotic rate of 7 per 5 mm² ; the median follow-up was 5.7 yrs. Immunohistochemistry for KIT was positive in 36 (97.3%) tumors. Mutational testing revealed KIT and PDGFRA mutations in 68.4% and 21.0% of cases, respectively; no SDHX, KIT, or PDGFRA alterations were found in two cases (one of which was succinate dehydrogenase-deficient). According to standard risk assessment criteria for progressive disease, 18 tumors were high-risk, 5 were moderate-risk, 4 were low-risk, 5 were very low-risk, and 1 had no risk. Disease progression was exclusive to high-risk tumors (79%; p<0.001).

CONCLUSIONS

Pleomorphism is present prior to therapy in approximately 2% of GISTs and is most prevalent in high-risk gastric and small intestinal GISTs. Pleomorphism appears to have no prognostic significance beyond conventional risk stratification.

Anti-tachycardia pacing for non-fast and fast ventricular tachycardias in individual Japanese patients: From Nippon-storm study

BACKGROUND

Anti-tachycardia pacing (ATP) delivered from an implantable device is a useful tool to terminate ventricular tachycardia (VT). But its real-world efficacy for those patients having multiple VTs with varying VT rates has not been fully studied.

METHODS

Using the Nippon-storm study database, efficacy of patient-by-patient basis ATP programing for Japanese patients having both non-fast (120-187 bpm) and fast VT (≥188 bpm) was assessed. According to the useful criteria of ≥50% success termination by ATP, patients were divided into three subgroups; success ≥50% for both non-fast and fast VT (both useful), ≥50% only for non-fast VT (non-fast VT useful), or ≥50% for neither non-fast nor fast VT (neither useful).

RESULTS

During a median follow-up of 28 months, ATP terminated 184 of the 203 non-fast VT episodes (91%) and 86 of the 113 fast VT episodes (76%) in all 41 patients. In the patient-by-patient analysis, efficacy of ATP was not different between non-fast and fast VT in most of the patients (36/41 = 88%); 32 patients were in the both useful and four other patients in the neither useful. Neither ischemic nor non-ischemic structural heart disease was associated with the ATP efficacy, whereas LVEF more than 37.0% and non-prescribed amiodarone were characteristics of the patients classified into the both useful.

CONCLUSIONS

ATP well terminated both non-fast and fast VT occurring in individual Japanese patients with various structural heart diseases in the real-world device treatment and this finding further supports ATP programing for all device tachycardia detection zones in most patients with multiple VTs.

Growth Phase Dependent Cell Shape of Haloarcula

Several haloarchaea are reported to be pleomorphic, while others exhibit remarkable shapes, such as squares. Recently, Haloferax volcanii was found to alter its morphology during growth. Cells are motile rods in early exponential phase, and immotile plates in stationary phase. It is unknown if this growth phase dependent cell shape alteration is a specific feature of Hfx. volcanii, or conserved amongst haloarchaea. Here, we studied the cell shape and motility of two haloarchaea species Haloarcula hispanica and Haloarcula californiae. With a combination of light and electron microscopy, we observed that both strains undergo a growth phase dependent morphological development, albeit in a slightly different fashion as Hfx. volcanii. For both Haloarcula strains, the cell size is changing throughout growth. Cell shape seems to be related with motility, as highly motile cells on semi-solid agar plates are predominantly rod-shaped. We conclude that the growth phase dependent cell morphology alteration might be a common feature amongst haloarchaea, and that cell shape is generally linked with a motile life style. The conservation of this phenomenon underscores the importance of studies of the molecular mechanisms regulating cell shape in archaea.

Ionic Strength-Dependent, Reversible Pleomorphism of Recombinant Newcastle Disease Virus

A genetically modified, recombinant form of Newcastle disease virus (rNDV) undergoes ionic strength-dependent changes in morphology, as observed by cryo-electron microscopy (cEM). In hypotonic solutions with ionic strengths ranging from < 0.01 to 0.02 M, rNDV virions are spherical or predominantly spherical. In isotonic and hypertonic solutions, rNDV displays pleomorphism and contains a mixed population of spherical and elongated particles, indicating that a change from spherical to elongated shape is induced with increasing salt concentration. This ionic strength-dependent transition is largely reversible, as determined by cEM. Concomitantly, we measured infectious titers of these same rNDV samples at different ionic strengths using a fluorescent focus assay (FFA). The infectivity of oncolytic rNDV was found to be independent of ionic strength, ranging from 0.01 M to approximately 0.5 M. These structural and functional observations, in combination, suggest that infectivity (and, by inference, oncolytic activity) of rNDV virions is fully maintained in their pleomorphic forms.IMPORTANCE Oncolytic viruses are being developed for cancer therapy, as they selectively target, infect, and kill cancer cells. NDV is particularly attractive because while it is pathogenic to avians (e.g., chickens), it does not cause significant viremia in humans. We have developed a genetically modified recombinant NDV (rNDV) that has much reduced pathogenicity in chickens but is highly oncolytic. The morphology of rNDV transitions from spherical at very low salt concentrations to a heterogeneous population of spherical and elongated virions in isotonic (physiologic salt concentration) and hypertonic solutions. The infectivity (cell-killing activity by infecting cells) of rNDV is unaltered by changes in salt concentration despite morphological changes. These observations are significant for purification and formulation of rNDV, as exposure to different salt concentrations may be needed. Importantly, at physiological salt concentration, relevant to clinical testing, infectivity and, therefore, oncolytic activity will not be compromised despite morphological heterogeneity.

Solitary Fibrous Tumor of Pancreas With Unusual Features: A Case Report

Solitary fibrous tumor (SFT) is an uncommon fibroblastic neoplasm that is most commonly associated with the pleura but has also been reported in almost all anatomic sites. Although the majority of SFTs are benign, few cases follow a malignant clinical course and may recur and/or metastasize after several years of their original occurrence. Only 16 cases of pancreatic SFTs are reported so far, and only one has metastasized to lung and subcutis. Pancreatic SFT resembles more common neuroendocrine tumor and gastrointestinal stromal tumor (GIST) radiographically and is at times almost indistinguishable from GIST histologically. Diagnosis of SFTs particularly, if attempted on biopsied specimens, can be very challenging due to its rare occurrence and nondescript morphology. It is imperative to understand the pathological spectrum of this entity to avoid misdiagnosis. We report a case of pancreatic SFT in a 43-year-old male with some unusual morphologic and immunohistochemical features including pseudoangiomatous growth pattern, a hypercellular area demonstrating nuclear pleomorphism, and only focal positivity for cluster of differentiation (CD)34. These atypical features can pose even more diagnostic challenge by causing additional confusion with other malignancies like dedifferentiated liposarcoma and vascular tumors. The potential diagnostic pitfalls are discussed.

Giant cell-rich osteosarcoma - A rare case

Giant cell-rich osteosarcoma (GCRO) is an exceedingly rare histological variant of conventional primary osteosarcoma. It constitutes about 1%-3% of all osteosarcomas, and is extremely uncommon in the maxillofacial region. The unusual histopathological appearance and the rarity of the lesion poses a great diagnostic challenge. This article aims to present a rare case of GCRO involving the mandible in a 52-year-old male patient.

Phenotypic Variability Correlates with Clinical Outcome in Cryptococcus Isolates Obtained from Botswanan HIV/AIDS Patients

Pathogenic species of Cryptococcus cause hundreds of thousands of deaths annually. Considerable phenotypic variation is exhibited during infection, including increased capsule size, capsule shedding, giant cells (≥15 μm), and micro cells (≤1 μm). We examined 70 clinical isolates of Cryptococcus neoformans and Cryptococcus tetragattii from HIV/AIDS patients in Botswana to determine whether the capacity to produce morphological variants was associated with clinical parameters. Isolates were cultured under conditions designed to simulate in vivo stresses. Substantial variation was seen across morphological and clinical data. Giant cells were more common in C. tetragattii, while micro cells and shed capsule occurred in C. neoformans only. Phenotypic variables fell into two groups associated with differing symptoms. The production of "large" phenotypes (greater cell and capsule size and giant cells) was associated with higher CD4 count and was negatively correlated with intracranial pressure indicators, suggesting that these are induced in early stage infection. "Small" phenotypes (micro cells and shed capsule) were associated with lower CD4 counts, negatively correlated with meningeal inflammation indicators, and positively correlated with intracranial pressure indicators, suggesting that they are produced later during infection and may contribute to immune suppression and promote proliferation and dissemination. These trends persisted at the species level, indicating that they were not driven by association with particular Cryptococcus species. Isolates possessing giant cells, micro cells, and shed capsule were rare, but strikingly, they were associated with patient death (P = 0.0165). Our data indicate that pleomorphism is an important driver in Cryptococcus infection.IMPORTANCE Cryptococcosis results in hundreds of thousands of deaths annually, predominantly in sub-Saharan Africa. Cryptococcus is an encapsulated yeast, and during infection, cells have the capacity for substantial morphological changes, including capsule enlargement and shedding and variations in cell shape and size. In this study, we examined 70 Cryptococcus isolates causing meningitis in HIV/AIDS patients in Botswana in order to look for associations between phenotypic variation and clinical symptoms. Four variant phenotypes were seen across strains: giant cells of ≥15 µm, micro cells of ≤1 µm, shed extracellular capsule, and irregularly shaped cells. We found that "large" and "small" phenotypes were associated with differing disease symptoms, indicating that their production may be important during the disease process. Overall, our study indicates that Cryptococcus strains that can switch on cell types under different situations may be more able to sustain infection and resist the host response.

Comparative Evaluation of Corneal Endothelium in Diabetic Patients Undergoing Phacoemulsification

PURPOSE

To determine if phacoemulsification with intraocular lens implantation has a greater impact on the corneal endothelium of type 2 diabetic patients as compared to nondiabetics.

MATERIALS AND METHODS

This study compared the endothelial status in 60 diabetics with good glycemic control and 60 nondiabetics before and after uneventful phacoemulsification. Central corneal endothelial cell density, percentage hexagonality and percentage coefficient of variation (%CV) were measured using a specular microscope.

RESULTS

Data were age and sex matched. Diabetics showed significantly higher loss in endothelial cell count as compared to nondiabetics. At the end of 3 months, there was a decline of 157 endothelial cell (standard deviation [SD] 90) in the diabetic group and 121 (SD 50) in the control group. This was statistically significant (P = 0.008). Furthermore, the diabetics showed a slower recovery trend in the endothelial healing response as evidenced by lower change in the %CV. The change in %CV was 4.5 in the control group and 3.1 in diabetic group which was statistically significant (P = 0.016). Significant correlation was found between energy used and change in endothelial count as well as %CV in nondiabetics only.

CONCLUSION

In spite of good glycemic control, diabetics have significantly more endothelial damage in comparison to nondiabetics with similar nuclear grading and phaco energy used. This warrants a more careful use of phaco energy in diabetics.

Comprehensive and Integrated Genomic Characterization of Adult Soft Tissue Sarcomas

Sarcomas are a broad family of mesenchymal malignancies exhibiting remarkable histologic diversity. We describe the multi-platform molecular landscape of 206 adult soft tissue sarcomas representing 6 major types. Along with novel insights into the biology of individual sarcoma types, we report three overarching findings: (1) unlike most epithelial malignancies, these sarcomas (excepting synovial sarcoma) are characterized predominantly by copy-number changes, with low mutational loads and only a few genes (TP53, ATRX, RB1) highly recurrently mutated across sarcoma types; (2) within sarcoma types, genomic and regulomic diversity of driver pathways defines molecular subtypes associated with patient outcome; and (3) the immune microenvironment, inferred from DNA methylation and mRNA profiles, associates with outcome and may inform clinical trials of immune checkpoint inhibitors. Overall, this large-scale analysis reveals previously unappreciated sarcoma-type-specific changes in copy number, methylation, RNA, and protein, providing insights into refining sarcoma therapy and relationships to other cancer types.

Usefulness of FTIR spectroscopy to distinguish rough and smooth variants of Lactobacillus farciminis CNCM-I-3699

In this study, the potential of Fourier transform infrared (FTIR) spectroscopy for assessing putative biochemical and structural differences between the two variants, rough (R) and smooth (S), of Lactobacillus farciminis CNCM-I-3699, a pleomorphic strain, was investigated. The main differences observed were localized in the polysaccharide (1200-900 cm-1) and protein (1700-1500 cm-1) regions. Based on spectral information in these two spectral ranges, clustering resulted in a dendrogram that showed a clear discrimination between both morphotypes. Significant increases in favor of morphotype S compared to R at specific wavenumbers for polysaccharides (22.18% vs. 5.24% at 1068 cm-1) and capsular polysaccharides (16% vs. 13.17% at 1048 cm-1) were recorded. Compared to S, the morphotype R exhibits a 1.27-fold higher signal at the wavenumber of 1637 cm-1 assigned to the amide I β-sheet and a 2.71-fold higher signal at the wavenumber of 1513 cm-1 assigned to the tyrosine involved in the β-sheet arrangement of proteins. The FTIR analysis is efficient to separate and give data on mainly surface component differences observed previously between S colony morphotype (ropy and exopolysaccharide positive) and the R colony morphotype (non-ropy but highly autoaggregative).

The Molecular Basis of Noncanonical Bacterial Morphology

Bacteria come in a wide variety of shapes and sizes. The true picture of bacterial morphological diversity is likely skewed due to an experimental focus on pathogens and industrially relevant organisms. Indeed, most of the work elucidating the genes and molecular processes involved in maintaining bacterial morphology has been limited to rod- or coccal-shaped model systems. The mechanisms of shape evolution, the molecular processes underlying diverse shapes and growth modes, and how individual cells can dynamically modulate their shape are just beginning to be revealed. Here we discuss recent work aimed at advancing our knowledge of shape diversity and uncovering the molecular basis for shape generation in noncanonical and morphologically complex bacteria.

Pleomorphism and Viability of the Lyme Disease Pathogen Borrelia burgdorferi Exposed to Physiological Stress Conditions: A Correlative Cryo-Fluorescence and Cryo-Scanning Electron Microscopy Study

To understand the response of the Lyme disease spirochete Borrelia burgdorferi exposed to stress conditions and assess the viability of this spirochete, we used a correlative cryo-fluorescence and cryo-scanning microscopy approach. This approach enables simple exposition of bacteria to various experimental conditions that can be stopped at certain time intervals by cryo-immobilization, examination of cell viability without necessity to maintain suitable culture conditions during viability assays, and visualization of structures in their native state at high magnification. We focused on rare and transient events e.g., the formation of round bodies and the presence of membranous blebs in spirochetes exposed to culture medium, host sera either without or with the bacteriolytic effect and water. We described all crucial steps of the workflow, particularly the influence of freeze-etching and accelerating voltage on the visualization of topography. With the help of newly designed cryo-transport device, we achieved greater reproducibility.

Cell Pleomorphism and Cytoskeleton Disorganization in Human Liver Cancer

BACKGROUND/AIM

Nucleoskeleton maintains the framework of a cell nucleus that is required for a variety of nuclear functions. However, the nature of nucleoskeleton structure has not been yet clearly elucidated due to microscopy visualization limitations. Plectin, a nuclear pore-permeable component of cytoskeleton, exhibits a role of cross-linking between cytoplasmic intermediate filaments and nuclear lamins. Presumably, plectin is also a part of nucleoskeleton. Previously, we demonstrated that pleomorphism of hepatoma cells is the consequence of cytoskeletal changes mediated by plectin deficiency. In this study, we applied a variety of technologies to detect the cytoskeletons in liver cells.

MATERIALS AND METHODS AND RESULTS

The images of confocal microscopy did not show the existence of plectin, intermediate filaments, microfilaments and microtubules in hepatic nuclei. However, in the isolated nuclear preparation, immunohistochemical staining revealed positive results for plectin and cytoskeletal proteins that may contribute to the contamination derived from cytoplasmic residues. Therefore, confocal microscopy provides a simple and effective technology to observe the framework of nucleoskeleton. Accordingly, we verified that cytoskeletons are not found in hepatic cell nuclei. Furthermore, the siRNA-mediated knockdown of plectin in liver cells leads to collapsed cytoskeleton, cell transformation and pleomorphic nuclei.

CONCLUSION

Plectin and cytoskeletons were not detected in the nuclei of liver cells compared to the results of confocal microscopy. Despite the absence of nuclear plectin and cytoskeletal filaments, the evidence provided support that nuclear pleomorphism of cancer cells is correlated with the cytoplasmic disorganization of cytoskeleton.

A novel method for morphological pleomorphism and heterogeneity quantitative measurement: Named cell feature level co-occurrence matrix

Background:

Recent developments in molecular pathology and genetic/epigenetic analysis of cancer tissue have resulted in a marked increase in objective and measurable data. In comparison, the traditional morphological analysis approach to pathology diagnosis, which can connect these molecular data and clinical diagnosis, is still mostly subjective. Even though the advent and popularization of digital pathology has provided a boost to computer-aided diagnosis, some important pathological concepts still remain largely non-quantitative and their associated data measurements depend on the pathologist's sense and experience. Such features include pleomorphism and heterogeneity.

Methods and Results:

In this paper, we propose a method for the objective measurement of pleomorphism and heterogeneity, using the cell-level co-occurrence matrix. Our method is based on the widely used Gray-level co-occurrence matrix (GLCM), where relations between neighboring pixel intensity levels are captured into a co-occurrence matrix, followed by the application of analysis functions such as Haralick features. In the pathological tissue image, through image processing techniques, each nucleus can be measured and each nucleus has its own measureable features like nucleus size, roundness, contour length, intra-nucleus texture data (GLCM is one of the methods). In GLCM each nucleus in the tissue image corresponds to one pixel. In this approach the most important point is how to define the neighborhood of each nucleus. We define three types of neighborhoods of a nucleus, then create the co-occurrence matrix and apply Haralick feature functions. In each image pleomorphism and heterogeneity are then determined quantitatively. For our method, one pixel corresponds to one nucleus feature, and we therefore named our method Cell Feature Level Co-occurrence Matrix (CFLCM). We tested this method for several nucleus features.

Conclusion:

CFLCM is showed as a useful quantitative method for pleomorphism and heterogeneity on histopathological image analysis.

Recommended names for pleomorphic genera in Dothideomycetes

This paper provides recommendations of one name for use among pleomorphic genera in Dothideomycetes by the Working Group on Dothideomycetes established under the auspices of the International Commission on the Taxonomy of Fungi (ICTF). A number of these generic names are proposed for protection because they do not have priority and/or the generic name selected for use is asexually typified. These include: Acrogenospora over Farlowiella; Alternaria over Allewia, Lewia, and Crivellia; Botryosphaeria over Fusicoccum; Camarosporula over Anthracostroma; Capnodium over Polychaeton; Cladosporium over Davidiella; Corynespora over Corynesporasca; Curvularia over Pseudocochliobolus; Elsinoë over Sphaceloma; Excipulariopsis over Kentingia; Exosporiella over Anomalemma; Exserohilum over Setosphaeria; Gemmamyces over Megaloseptoria; Kellermania over Planistromella; Kirschsteiniothelia over Dendryphiopsis; Lecanosticta over Eruptio; Paranectriella over Araneomyces; Phaeosphaeria over Phaeoseptoria; Phyllosticta over Guignardia; Podonectria over Tetracrium; Polythrincium over Cymadothea; Prosthemium over Pleomassaria; Ramularia over Mycosphaerella; Sphaerellopsis over Eudarluca; Sphaeropsis over Phaeobotryosphaeria; Stemphylium over Pleospora; Teratosphaeria over Kirramyces and Colletogloeopsis; Tetraploa over Tetraplosphaeria; Venturia over Fusicladium and Pollaccia; and Zeloasperisporium over Neomicrothyrium. Twenty new combinations are made: Acrogenospora carmichaeliana (Berk.) Rossman & Crous, Alternaria scrophulariae (Desm.) Rossman & Crous, Pyrenophora catenaria (Drechsler) Rossman & K.D. Hyde, P. dematioidea (Bubák & Wróbl.) Rossman & K.D. Hyde, P. fugax (Wallr.) Rossman & K.D. Hyde, P. nobleae (McKenzie & D. Matthews) Rossman & K.D. Hyde, P. triseptata (Drechsler) Rossman & K.D. Hyde, Schizothyrium cryptogamum (Batzer & Crous) Crous & Batzer, S. cylindricum (G.Y. Sun et al.) Crous & Batzer, S. emperorae (G.Y. Sun & L. Gao) Crous & Batzer, S. inaequale (G.Y. Sun & L. Gao) Crous & Batzer, S. musae (G.Y. Sun & L. Gao) Crous & Batzer, S. qianense (G.Y. Sun & Y.Q. Ma) Crous & Batzer, S. tardecrescens (Batzer & Crous) Crous & Batzer, S. wisconsinense (Batzer & Crous) Crous & Batzer, Teratosphaeria epicoccoides (Cooke & Massee) Rossman & W.C. Allen, Venturia catenospora (Butin) Rossman & Crous, V. convolvularum (Ondrej) Rossman & Crous, V. oleaginea (Castagne) Rossman & Crous, and V. phillyreae (Nicolas & Aggéry) Rossman & Crous, combs. nov. Three replacement names are also proposed: Pyrenophora grahamii Rossman & K.D. Hyde, Schizothyrium sunii Crous & Batzer, and Venturia barriae Rossman & Crous noms. nov.

Diversity of Histologic Patterns and Expression of Cytoskeletal Proteins in Canine Skeletal Osteosarcoma

Osteosarcoma (OS), the most common bone tumor, includes OS of the head (OSH) and appendicular OS (OSA). In dogs, it is classified into 6 histologic subtypes: osteoblastic, chondroblastic, fibroblastic, telangiectatic, giant cell, and poorly differentiated. This study investigated the significance of the histologic classification relevant to clinical outcome and the histologic and immunohistochemical relationships between pleomorphism and expression of cytoskeletal proteins in 60 cases each of OSH and OSA. Most neoplasms exhibited histologic diversity, and 64% of OS contained multiple subtypes. In addition to the above 6 subtypes, myxoid, round cell, and epithelioid subtypes were observed. Although the epithelioid subtypes were observed in only OSH, no significant difference in the frequency of other subtypes was observed. Also, no significant relevance was observed between the clinical outcome and histologic subtypes. Cytokeratin (CK) was expressed in both epithelioid and sarcomatoid tumor cells in various subtypes, and all CK-positive tumor cells also expressed vimentin. Vimentin and α-smooth muscle actin (SMA) were expressed in all subtypes. A few SMA-positive spindle-shaped tumor cells exhibited desmin expression. Glial fibrillary acidic protein-positive tumor cells were observed in many subtypes, and some of these cells showed neurofilament expression. Although OSH exhibited significantly stronger immunoreactivity for SMA than OSA, no significant difference in other cytoskeletal proteins was observed. Some tumor cells had cytoskeletal protein expression compatible with the corresponding histologic subtypes, such as CK in the epithelioid subtype and SMA in the fibroblastic subtype. Thus, canine skeletal OS is composed of pleomorphic and heterogenous tumor cells as is reflected in the diversity of histologic patterns and expression of cytoskeletal proteins.

Comparison of the findings of endothelial specular microscopy before and after corneal cross-linking

Background:

To report the long-term findings of corneal cross-linking (CXL) with riboflavin drops on the corneal endothelial cell.

Materials and Methods:

In this prospective non-randomized study, we aim to assess the long-term safety of CXL on the corneal endothelium for the treatment of progressive keratoconus, by endothelial specular microscopy. A total of 68 eyes of 42 keratoconus patients were selected. We checked the corneal thickness (with ultrasonic pachymetry), endothelial cell density, pleomorphism, and polymegathism (with specular microscopy) of the endothelial cells, before CXL and one year after this procedure.

Results:

The mean ± SD of the preoperative and postoperative corneal thicknesses were 470 ± 40 μm and 469.8 ± 42 μm, respectively (p-value = 0.591). The mean ± SD of the preoperative and postoperative endothelial cell densities were 2753 ± 230 cells/mm[2] and 2699 ± 210 cells/mm,[2] respectively (p-value = 0.004). We found reduction in the endothelial cell density after CXL, but this reduction was less significant in a corneal thickness of less than 400 μm (which was treated with hypo-osmolar riboflavin 0.1% drops) compared to the corneal thickness of more than 450 μm. We did not find any significant differences in the cell shapes (pleomorphism) (p-value = 0.517), but the cell sizes (polymegathism) were changed after the procedure (p-value = 0.021).

Conclusion:

We found a significant decrease in endothelial corneal cell density after CXL, but this reduction was low; also the size of these cells increased after CXL. We believe that other parameters besides the corneal thickness may be the determinant factors for the changing of cell density and cell size in corneal endothelial cells.

Candida albicans morphologies revealed by scanning electron microscopy analysis

Scanning electron microscope (SEM) observations were used to analyze particular morphologies of Candida albicans clinical isolate (strain 82) and mutants defective in hyphae-promoting genes EFG1 (strain HLC52) and/or CPH1 (strains HLC54 and Can16). Transcription factors Efg1 and Cph1 play role in regulating filamentation and adhesion of C. albicans’ morphologies. Comparative analysis of such mutants and clinical isolate showed that Efg1 is required for human serum-induced cell growth and morphological switching. In the study, distinct differences between ultrastructural patterns of clinical strain’s and null mutants’ morphologies were observed (spherical vs tube-like blastoconidia, or solid and fragile constricted septa vs only the latter observed in strains with EFG1 deleted). In addition, wild type strain displayed smooth colonies of cells in comparison to mutants which exhibited wrinkled phenotype. It was observed that blastoconidia of clinical strain exhibited either polarly or randomly located budding. Contrariwise, morphotypes of mutants showed either multiple polar budding or a centrally located single bud scar (mother-daughter cell junction) distinguishing tube-like yeast/pseudohyphal growth (the length-to-width ratios larger than 1.5). In their planktonic form of growth, blastoconidia of clinical bloodstream isolate formed constitutively true hyphae under undiluted human serum inducing conditions. It was found that true hyphae are essential elements for developing structural integrity of conglomerate, as mutants displaying defects in their flocculation and conglomerate-forming abilities in serum. While filamentation is an important virulence trait in C. albicans the true hyphae are the morphologies which may be expected to play a role in bloodstream infections.

Structure, biochemical characterization and analysis of the pleomorphism of carboxylesterase Cest-2923 from Lactobacillus plantarum WCFS1

The hydrolase fold is one of the most versatile structures in the protein realm according to the diversity of sequences adopting such a three-dimensional architecture. In the present study, we clarified the crystal structure of the carboxylesterase Cest-2923 from the lactic acid bacterium Lactobacillus plantarum WCFS1 refined to 2.1 Å resolution, determined its main biochemical characteristics and also carried out an analysis of its associative behaviour in solution. We found that the versatility of a canonical α/β hydrolase fold, the basic framework of the crystal structure of Cest-2923, also extends to its oligomeric behaviour in solution. Thus, we discovered that Cest-2923 exhibits a pH-dependent pleomorphic behaviour in solution involving monomers, canonical dimers and tetramers. Although, at neutral pH, the system is mainly shifted to dimeric species, under acidic conditions, tetrameric species predominate. Despite these tetramers resulting from the association of canonical dimers, as is commonly found in many other carboxylesterases from the hormone-sensitive lipase family, they can be defined as 'noncanonical' because they represent a different association mode. We identified this same type of tetramer in the closest relative of Cest-2923 that has been structurally characterized: the sugar hydrolase YeeB from Lactococcus lactis. The observed associative behaviour is consistent with the different crystallographic results for Cest-2923 from structural genomics consortia. Finally, the presence of sulfate or acetate molecules (depending on the crystal form analysed) in the close vicinity of the nucleophile Ser116 allows us to identify interactions with the putative oxyanion hole and deduce the existence of hydrolytic activity within Cest-2923 crystals.

Cellular pleomorphism in papillary tumors of the pineal region

Papillary tumor of the pineal region (PTPR) is a recently recognized entity. We present the pathologic findings of two cases of PTPR as examples, and discuss the presence of cellular pleomorphism in these tumors. Patient 1 is a 48-year-old man with a pineal region mass. The tumor had unique biphasic patterns, papillary/pseudopapillary areas, and increased mitotic activity. Juxtaposed areas had marked pleomorphism, including nuclear enlargement, smudgy chromatin, nuclear pseudoinclusions, and cytoplasmic vacuolation. Mitoses were absent in these areas. Immunohistochemical staining revealed strong S100 expression. CAM 5.2 and CK18 were strongly positive in a patchy fashion. MIB1 labeling indices were high in classic PTPR regions but very low in pleomorphic areas. Patient 2 was a 35-year-old male with a pineal region tumor characterized by papillary architecture and overall cellular monotony, rare mitoses, and pleomorphism as a more isolated finding, with associated nuclear enlargement and crowding. S100 and CAM 5.2 labeling were present, and MIB1 labeling index was very low throughout the tumor. We discuss the pathologic and phenotypic features of PTPR. Variable pleomorphism may be present, reflected in size variation and nuclear hyperchromasia, but was not accompanied by increased proliferative activity in these cases, suggesting a degenerative phenomenon.