Search

Myxofibrosarcoma (MFS) and undifferentiated pleomorphic sarcoma (UPS) frequently display infiltrative growth into the adjacent normal soft tissue. In this study, we aimed to determine whether the microscopic extension into surrounding normal tissue can influence the local recurrence of MFS and UPS. A total of 42 cases (22 MFS and 20 UPS) were examined. The length of the microscopic extension was measured from the edge of the main tumor mass to the end of infiltration. The length of 5.5 mm was selected as the optimal cut‐off value that could predict local recurrence using the receiver operating characteristic (ROC) curve and Youden index. Longer length of microscopic extension was significantly correlated with the status of resection margin (P = 0.032). The group with longer length of microscopic extension (>5.5 mm) had significantly worse recurrence‐free survival than the group with shorter length of microscopic extension (≤5.5 mm) (P = 0.000). Multivariate analysis revealed that the length of microscopic extension was independent predictors of recurrence‐free survival (P = 0.018). In conclusion, microscopic extensions at the edge of the main mass into the surrounding normal tissue were observed in most MFS and UPS patients, and the length of microscopic extension was associated with local recurrence. [ABSTRACT FROM AUTHOR]

Abstract: Pleomorphic xanthoastrocytoma (PXA) is a rare localized glioma characterized by frequent BRAF V600E mutation and CDKN2A/B deletion. We explored the association of copy‐number variants (CNVs) with BRAF mutations, tumor grade, and patient survival in a cohort of 41 PXA patients using OncoScan chromosomal microarray. Primary resection specimens were available in 38 cases, including 24 PXA and 14 anaplastic PXA (A‐PXA), 23 BRAF V600E mutant tumors (61%). CNVs were identified in all cases and most frequently involved chromosome 9 with homozygous CDKN2A/B deletion (n = 33, 87%), a higher proportion than previously detected by comparative genomic hybridization (50%–60%) (37). CDKN2A/B deletion was present in similar proportion of PXA (83%), A‐PXA (93%), BRAF V600E (87%), and wild‐type (87%) tumors. Whole chromosome gains/losses were frequent, including gains +7 (n = 15), +2 (n = 11), +5 (n = 10), +21 (n = 10), +20 (n = 9), +12 (n = 8), +15 (n = 8), and losses −22 (n = 11), −14 (n = 7), −13 (n = 5). Losses and copy‐neutral loss of heterozygosity were significantly more common in A‐PXA, involving chromosomes 22 (P = 0.009) and 14 (P = 0.03). Amplification of 8p and 12q was identified in a single tumor. Histologic grade was a robust predictor of overall survival (P = 0.003), while other copy‐number changes, including CDKN2A/B deletion, did not show significant association with survival. Distinct histologic patterns of anaplasia included increased mitotic activity in an otherwise classic PXA or associated with small cell, fibrillary, or epithelioid morphology, with loss of SMARCB1 expression in one case. In 10 cases, matched specimens were compared, including A‐PXA with areas of distinct low‐ and high‐grade morphology (n = 2), matched primary/tumor recurrence (n = 7), or both (n = 1). Copy‐number changes on recurrence/anaplastic transformation were complex and highly variable, from nearly identical profiles to numerous copy‐number changes. Overall, we confirm CDKN2A/B deletion as key a feature of PXA not associated with tumor grade or BRAF mutation, but central to the underlying genetics of PXA. [ABSTRACT FROM AUTHOR]

ALK rearrangements occur in up to 10% of spitzoid melanocytic neoplasms. No reported cases have shown homozygous deletion of 9p21 (CDKN2A) or gains of 6p25 (RREB1) or 11q13 (CCND1), which have been associated with aggressive clinical behavior. Here we report 2 unique cases. Case 1 occurred in a 9‐year‐old male with a 14‐mm nodule on the anterior left thigh. Biopsy revealed an ALK‐positive Spitz tumor containing an irregular nodule of densely packed melanocytes with increased mitoses and loss of p16 immunoreactivity. FISH analysis showed homozygous deletion of 9p21 and gain of 6p25. Sentinel lymph node biopsy revealed small subcapsular foci of tumor. Case 2 occurred in a 7‐year‐old female with a 12‐mm nodule on the anterior right ankle. Biopsy revealed an ALK‐positive Spitz tumor containing an expansile nodule of pleomorphic epithelioid melanocytes with numerous mitoses and loss of p16 immunoreactivity. By FISH, the nodule showed homozygous deletion of 9p21 and gains of 6p25 and 11q13. Our cases show the transformation of tumors produced by an activating kinase fusion gene (ALK) through secondary genetic changes including loss of tumor suppressor activity (CDKN2A). Long‐term follow up will be important to further define the behavior of these unique Spitz tumors. [ABSTRACT FROM AUTHOR]

Background: The authors hypothesized that histogenetic classification of salivary duct carcinoma (SDC) could account for de novo tumors and those with morphologic or molecular evidence (pleomorphic adenoma gene 1 [PLAG1], high-mobility group AT hook 2 [HMGA2] rearrangement, amplification) of pleomorphic adenoma (PA).Methods: SDCs (n = 66) were reviewed for morphologic evidence of PA. PLAG1 and HMGA2 alterations were detected by fluorescence in situ hybridization (FISH). PLAG1-positive tumors were tested by FISH for fibroblast growth factor receptor 1 (FGFR1) rearrangement. Thirty-nine tumors were analyzed using a commercial panel for mutations and copy number variations in 50 cancer-related genes.Results: On the basis of combined morphologic and molecular evidence of PA, 4 subsets of SDC emerged: 1) carcinomas with morphologic evidence of PA but intact PLAG1 and HMGA2 (n = 22); 2) carcinomas with PLAG1 alteration (n = 18) or 3) HMGA2 alteration (n = 12); and 4) de novo carcinomas, without morphologic or molecular evidence of PA (n = 14). The median disease-free survival was 37 months (95% confidence interval, 28.4-45.6 months). Disease-free survival and other clinicopathologic parameters did not differ for the subsets defined above. Combined Harvey rat sarcoma viral oncogene homolog/phosphatidylinositol-4,5-biphosphate 3-kinase, catalytic subunit α (HRAS/PIK3CA) mutations were observed predominantly in de novo carcinomas (5 of 8 vs 2 of 31 tumors; P = .035). Erb-B2 receptor tyrosine kinase 2 (ERBB2) copy number gain was not observed in de novo carcinomas (0 of 8 vs 12 of 31 tumors; P = .08). Tumor protein 53 (TP53) mutations were more common in SDC ex pleomorphic adenomas than in de novo carcinomas (17 of 31 vs 1 of 8 tumors; P = .033).Conclusions: The genetic profile of SDC varies with the absence or presence of pre-existing PA and its cytogenetic signature. Most de novo SDCs harbor combined HRAS/PIK3CA mutations and no ERBB2 amplification. Cancer 2016;122:3136-44. © 2016 American Cancer Society. [ABSTRACT FROM AUTHOR]

In accordance with recent terminology, it is proposed that malignant mesenchymoma should be renamed 'composite sarcoma' and defined as 'a sarcoma composed of two or more cellular types each of which is sufficiently differentiated to permit clear recognition of its histogenetic type microscopically, immunohistochemically or ultrastructurally; excluding fibrosarcomatous and high-grade pleomorphic undifferentiated sarcomatous component, dedifferentiated sarcoma and the combination of osteosarcoma and chondrosarcoma which is regarded as a single histogenetic type'. Four cases of primary osseous composite sarcoma ( POCS) were identified among 928 primary bone sarcomas. Their age ranged from 10 to 87 years, peak incidence in the second decade with equal sex distribution. Most presented with pain, commonest in the knee, affecting the metaphysis, appearing radiologically as expansile infiltrative osteolytic lesions with cortical erosion, periosteal reaction, variable extent of osteoblastic areas and soft tissue extension. All contained variable amounts of conventional high-grade osteosarcoma with or without chondrosarcoma component; the other constituents were liposarcoma, rhabdomyosarcoma and leiomyosarcoma. In all cases, Ki67 proliferative index was over 35%, there was no CDK4 and MDM2 amplification. The absence of low-grade component supported the de novo origin of POCS rather than derivation from divergent dedifferentiation. The two older patients with hitherto undescribed osteoleiomyosarcoma died 2 and 10 months after operation, whereas the two younger with osteorhabdomyosarcoma and osteoliposarcoma enjoyed disease-free survival at 16 and 6 years after chemotherapy despite the latter showing lung metastasis at presentation. Identification of the different lines of differentiation together with their approximate amounts and histological grades is therefore mandatory for POCS as multi-agent chemotherapy catered for each sarcoma component might offer hope for long-term disease-free survival. [ABSTRACT FROM AUTHOR]

Aims Metastasizing pleomorphic adenoma ( MPA) is a rare tumour, and its mechanism of metastasis still is unknown. To date, there has been no study on MPA genomics. We analysed primary and secondary MPAs with array comparative genomic hybridization to identify somatic copy number alterations and affected genes. Methods and results Tumour DNA samples from primary (parotid salivary gland) and secondary (scalp skin) MPAs were subjected to array comparative genomic hybridization investigation, and the data were analysed with NEXUS COPY NUMBER DISCOVERY. The primary MPA showed copy number losses affecting 3p22.2p14.3 and 19p13.3p123, and a complex pattern of four different deletions at chromosome 6. The 3p deletion encompassed several genes: CTNNB1, SETD2, BAP1, and PBRM1, among others. The secondary MPA showed a genomic profile similar to that of the primary MPA, with acquisition of additional copy number changes affecting 9p24.3p13.1 (loss), 19q11q13.43 (gain), and 22q11.1q13.33 (gain). Conclusion Our findings indicated a clonal origin of the secondary MPA, as both tumours shared a common profile of genomic copy number alterations. Furthermore, we were able to detect in the primary tumour a specific pattern of copy number alterations that could explain the metastasizing characteristic, whereas the secondary MPA showed a more unbalanced genome. [ABSTRACT FROM AUTHOR]

Subcutaneous panniculitis-like T-cell lymphoma ( SPTCL) is a type of skin lymphoma. Pleomorphic T-cells infiltrate the subcutaneous tissue and mimic lobular panniculitis. We report a case occurring in a 12-year-old Chinese boy who presented with multiple indolent erythematous subcutaneous nodules on both extremities without systemic symptoms. He had a protracted course of multiple erythematous subcutaneous nodules for 1 year and underwent biopsy of lesional skin for histology and T-cell receptor ( TCR) gene analysis. Histopathology showed infiltration of medium to large atypical pleomorphic cells involving the subcutis with characteristic rimming of fat spaces. TCR gene rearrangement shows monoclonal rearrangements of the TCR β and γ chains. Immunophenotypic studies showed that CD3, CD4, and CD8 were strongly and diffusely positive in lesional cells and that CD56 was focally positive. In contrast, these cells were negative for CD20, CD30, and CD68. The combined morphology, characteristic histologic features, and positive T-CR gene rearrangement supported a diagnosis of SPTCL. He is being treated with combination chemotherapy of cyclophosphamide, doxorubicin, vincristine, and prednisolone. [ABSTRACT FROM AUTHOR]

In virtually all bacteria, the cell wall is crucial for mechanical integrity and for determining cell shape. E scherichia coli's rod-like shape is maintained via the spatiotemporal patterning of cell-wall synthesis by the actin homologue MreB. Here, we transiently inhibited cell-wall synthesis in E . coli to generate cell-wall-deficient, spherical L-forms, and found that they robustly reverted to a rod-like shape within several generations after inhibition cessation. The chemical composition of the cell wall remained essentially unchanged during this process, as indicated by liquid chromatography. Throughout reversion, MreB localized to inwardly curved regions of the cell, and fluorescent cell wall labelling revealed that MreB targets synthesis to those regions. When exposed to the MreB inhibitor A22, reverting cells regrew a cell wall but failed to recover a rod-like shape. Our results suggest that MreB provides the geometric measure that allows E . coli to actively establish and regulate its morphology. [ABSTRACT FROM AUTHOR]

In possible scenarios on the origin of life, protocells represent the precursors of the first living cells. To study such hypothetical protocells, giant vesicles are being widely used as a simple model. Lipid vesicles can undergo complex morphological changes enabling self-reproduction such as growth, fission, and extra- and intravesicular budding. These properties of vesicular systems may in some way reflect the mechanism of reproduction used by protocells. Moreover, remarkable similarities exist between the morphological changes observed in giant vesicles and bacterial L-form cells, which represent bacteria that have lost their rigid cell wall, but retain the ability to reproduce. L-forms feature a dismantled cellular structure and are unable to carry out classical binary fission. We propose that the striking similarities in morphological transitions of L-forms and giant lipid vesicles may provide insights into primitive reproductive mechanisms and contribute to a better understanding of the origin and evolution of mechanisms of cell reproduction. Editor's suggested further reading in BioEssays Synthesizing artificial cells from giant unilamellar vesicles: State-of-the art in the development of microfluidic technology [ABSTRACT FROM AUTHOR]

ABSTRACT Background and aim: Breast lesions, though more common than most other organ lesions, still deserve a special place in every pathologists mind because of their diversity. Lesions in the breast vary from simple fibroadenoma to various commoner carcinomas like infiltrating ductal carcinomas, to rarer entities, such as angiosarcoma, hemangiopericytoma, nodular hidradenoma, pleomorphic variant of lobular carcinoma, medullary carcinomas and carcinoid tumors; which can be compared to 'an oasis in the desert'. Methods: A 3-year retrospective study was carried out to evaluate the incidence and pattern of rare breast lesions in an upcoming teaching hospital, along with clinicohistopathological correlation. Specimens were preserved in 10% formalin and processed in a routine manner. Hematoxylin-eosin sections were studied and a morphological diagnosis was reached. Results: Some rare entities, namely pleomorphic variant of lobular carcinoma, medullary carcinoma, mucinous carcinoma, tubular carcinoma, apocrine carcinoma, cribriform carcinoma, anaplastic carcinoma, occult breast carcinoma, hemangiopericytoma, angiosarcoma, carcinoid tumor and nodular hidradenoma, were diagnosed. A brief review of published work of the various rare entities encountered in the present study was also made. Conclusions: It is imperative to be vigilant during microscopic diagnosis so that rare tumors are not missed. [ABSTRACT FROM AUTHOR]

Vitamin D research is discussed in light of the hypothesis that the lower average levels of vitamin D frequently observed in autoimmune disease are not a sign of deficiency. Instead, it is proposed that the lower levels result from chronic infection with intracellular bacteria that dysregulate vitamin D metabolism by causing vitamin D receptor (VDR) dysfunction within phagocytes. The VDR dysfunction causes a decline in innate immune function that causes susceptibility to additional infections that contribute to disease progression. Evidence has been accumulating that indicates that a number of autoimmune diseases can be reversed by gradually restoring VDR function with the VDR agonist olmesartan and subinhibitory dosages of certain bacteriostatic antibiotics. Diseases showing favorable responses to treatment so far include systemic lupus erythematosis, rheumatoid arthritis, scleroderma, sarcoidosis, Sjogren's syndrome, autoimmune thyroid disease, psoriasis, ankylosing spondylitis, Reiter's syndrome, type I and II diabetes mellitus, and uveitis. Disease reversal using this approach requires limitation of vitamin D in order to avoid contributing to dysfunction of nuclear receptors and subsequent negative consequences for immune and endocrine function. Immunopathological reactions accompanying bacterial cell death require a gradual elimination of pathogens over several years. Practical and theoretical implications are discussed, along with the compatibility of this model with current research. [ABSTRACT FROM AUTHOR]

The predictive value of cadherin-11, tenascin, fascin, and mucin-1 as markers for the likelihood of recurrence in pleomorphic adenoma of the parotid gland was examined. In this retrospective study we analysed 20 tumours from16 patients by immunohistochemistry. Staining intensities were measured using a semiquantitative scoring approach; localisation (tumour centre vs border) as well as clinical data were analysed and correlated with follow-up. Cadherin-11 was increased in recurrent tumours. However, no changes of fascin, tenascin or mucin-1 were observed. Cadherin-11 and fascin were increased in primary tumours of patients with later recurrence, with fascin upregulation restricted to the tumour border. In conclusion, cadherin-11 and fascin should be further analysed for their value as markers for later recurrence in pleomorphic adenoma. Our observations might reflect dysregulation of cellular pathways contributing to cellular dissemination, which might potentially result in later recurrence. [ABSTRACT FROM AUTHOR]

The blood of 21 adult South American mouse opossums ( Thylamys elegans) captured from April through August of 2005 in central Chile was examined for parasites. Light microscopic analysis of blood smears initially suggested that a highly pleomorphic Hepatozoon species typical of American opossums was infecting erythrocytes. Unexpectedly, amplification by PCR and sequencing of a DNA fragment of the small subunit rDNA combined with phylogenetic analyses indicated that the parasite is not a member of the suborder Adeleorina, which includes the Haemogregarina and Hepatozoon species, but that it is a clearly distinct member of the suborder Eimeriorina, which includes the cyst-forming family Sarcocystidae. Therefore, a reclassification of this unusual intraerythrocytic apicomplexan will require additional life cycle, microscopic, and molecular analyses. [ABSTRACT FROM AUTHOR]

Cytologic pleomorphism has been described in a limited number of benign pineal tumors, namely pineocytoma (PC) and pineal parenchymal tumors (PPTs) of intermediate differentiation (PPTID). We examined the clinicopathologic features in a retrospective series of 14 cases (seven females and seven males aged from 10 to 65 years) of pleomorphic PPT. Seven cases were PC, with no mitoses and with areas of tumoral cells forming large pineocytomatous rosettes and other areas with giant cells containing hyperchromatic nuclei. The other seven were PPTID, presenting few mitoses (≤2), a Ki67 proliferation index between 3% and 7%, and predominantly composed of small neoplastic cells and scattered giant cells, sometimes multinucleated. In the 14 tumors, the proportion of pleomorphic areas was variable. Most tumoral cells showed extensive neuronal differentiation with strong expression of neuron-specific enolase, synaptophysin and neurofilaments. Some of the neoplastic cells expressed S100 protein. The follow-up period ranged from 1.2 to 13 years and only one PC and one PPTID progressed after stereotactic biopsy or incomplete resection. The lack of invasiveness and the low proliferation index of these tumors suggest a benign clinical course despite the marked pleomorphism, the latter of which can lead to upgrading. [ABSTRACT FROM AUTHOR]

Although uncommon, many variants of lipomatous lesions in or around salivary glands have been reported in the literature. We report a series of three such cases in the minor salivary gland region. The first case (oral floor) is a well-circumscribed lipocytic lesion admixed with glandular components (mucous acini, serous demilunes and ducts). The second case (alveolar mucosa) is a diffuse lipomatous proliferation with entrapped salivary glandular elements, muscles and blood vessels. The third case (palate) is similar to the first case but the gland is located at the periphery of the lesion. The purpose of the article was to report these three lesions and discuss in relation to other pertaining lipomatous lesions (sialolipoma, lipoadenoma, lipomatosis, lipometaplasia in pleomorphic adenoma and infiltrating lipoma). [ABSTRACT FROM AUTHOR]

Gp26 is one of three phage P22-encoded tail accessory factors essential for stabilization of viral DNA within the mature capsid. In solution, gp26 exists as an extended triple-stranded coiled-coil protein which shares profound structural similarities with class I viral membrane-fusion protein. In the cryo-EM reconstruction of P22 tail extracted from mature virions, gp26 forms an ∼220 Å extended needle structure emanating from the neck of the tail, which is likely to be brought into contact with the cell's outer membrane when the viral DNA-injection process is initiated. To shed light on the potential role of gp26 in cell-wall penetration and DNA injection, gp26 has been crystallized at acidic, neutral and alkaline pH. Crystals of native gp26 grown at pH 4.6 diffract X-rays to 2.0 Å resolution and belong to space group P21, with a dimer of trimeric gp26 molecules in the asymmetric unit. To study potential pH-induced conformational changes in the gp26 structure, a chimera of gp26 fused to maltose-binding protein (MBP-gp26) was generated. Hexagonal crystals of MBP-gp26 were obtained at neutral and alkaline pH using the high-throughput crystallization robot at the Hauptman–Woodward Medical Research Institute, Buffalo, NY, USA. These crystals diffract X-rays to beyond 2.0 Å resolution. Structural analysis of gp26 crystallized at acidic, neutral and alkaline pH is in progress. [ABSTRACT FROM AUTHOR]

Pleomorphic lipoma is an uncommon variant of lipoma, which microscopically may resemble a liposarcoma. However, it is a slow-growing and well-circumscribed lesion with a benign behavior. Therefore, recognizing this entity is extremely important to perform the proper treatment. We present an additional case of pleomorphic lipoma in the face, which to our knowledge seems to be the 11th case reported in the English-language literature. [ABSTRACT FROM AUTHOR]

Ralstonia solanacearumis an important plant pathogen in tropical and subtropical countries. Here, we describe the inhibition ofR. solanacearumas a result of increased phenols induced locally or systemically by an arbuscular mycorrhizal (AM) fungus. In pot cultures,R. solanacearumpopulations in the rhizosphere, on root surfaces and in the xylem were decreased by 26.7, 79.3 and 81.7%, respectively, following inoculation of tomato plants (Lycopersicon esculentumMill.) withGlomus versiformeBerch. Colonization of the plants by bothR. solanacearumandG. versiformeincreased the contents of soluble phenols and cell-wall bound phenols in root tissue, but with different patterns. WhereasR. solanacearumpreferably promoted the cell-wall bound phenol content,G. versiformepreferably enhanced the soluble phenol content. Split root experiments revealed thatR. Solanacearumwas inhibited byG. versiforme, and thatG. versiformealso increased the phenol content systemically, but to a lesser extent than locally. [ABSTRACT FROM AUTHOR]

This study investigated the immunolocalization of small and large proteoglycans (PGs), including decorin, biglycan, PG-M/versican and aggrecan, in salivary pleomorphic adenoma (PA) using monoclonal and polyclonal antibodies. In addition, a polyclonal antibody, A0082, recognizing blood vessels was also used to help identify truly mesenchymal tissues in PA. Decorin reactivity was detected only in tumor capsule and interstitial tissue of non-neoplastic salivary gland, but not in the tumor tissue. Biglycan was frequently revealed throughout the matrix of small chondroid regions and in the peripheral portion of larger chondroid regions. PG-M/versican was mainly localized to the truly mesenchymal tissues in PA and the innermost portion of tumor capsule. On the contrary, aggrecan was extensively expressed in the non-luminal epithelial areas as well as in the myxoid and chondroid areas, but not in the truly mesenchymal tissues. These findings suggest that aggrecan is the most widely distributed PG in PA and may be produced mainly by non-luminal tumor cells. The absence of aggrecan from the truly mesenchymal tissues argues against its origin from this source. Both aggrecan and biglycan may play important roles in the chondroid differentiation and morphogenesis of PA. [ABSTRACT FROM AUTHOR]

A little leaf disease has been observed in several plants of Eucalyptus microtheca Muell. grown in Wad Medani area, Sudan. The disease is characterized by general plant stunting, reduction in diameter and height of trunks of affected trees, yellowing and reduction in leaf size, shortening of internodes together with excessive proliferation of axillary shoots. Electron microscope observations on ultrathin sections have revealed the presence of pleomorphic bodies in the sieve elements of diseased but not of healthy plants. These bodies possess DNA strands, ribosome-like granules and a three-layered unit membrane well defined at high magnifications (>100,000) suggesting a mollicute nature of these bodies. Studies using semi-thin sections revealed the absence of helical forms. Thus, a mycoplasma-like organism (MLO) is suspected to be the agent responsible for the disease. The results are discussed with reference to the economic and environmental importance of this tree species in the Sudan and the possible threat of the disease to its cultivation. [ABSTRACT FROM AUTHOR]

These results provide the first account of the breakdown and utilization of DNA by an ericoid mycorrhizal fungus, and of its phosphodiesterase activity in vitro. Hymenoscyphus ericae (Read) Korf & Kernan grew well on DNA as a sole source of phosphorus (P), achieving greater mycelium dry weight than on an equivalent concentration of P supplied as orthophosphate. Some characteristics of the production and activity of extracellular (culture filtrate) and cell-wall bound phosphodiesterase in H. ericae are reported. At least part of the phosphodiesterase activity is attributed to the exonuclease 5' nucleotide diesterase on the basis of its high affinity for a specific substrate of this enzyme. The pH optima for extra-cellular and cell-wall-hound diesterase are acidic (pH 4.0-5.5), with considerable activity maintained in the pH range typical of organic soils under ericaceous plants (pH 3.0-4.5). The production of phosphodiesterase was not substrate-induced, since highest specific activity for wall-bound enzyme was found in culture grown without organic or inorganic P. The results are discussed in relation to the ecology and biology of acid organic soils on which ericaceous plants are dominant. [ABSTRACT FROM AUTHOR]

The pleomorphic bacterium Gardnerella vaginalis releases in the culture broth a haemolytic exotoxin (Gvh) which is probably a virulence determinant of this unique bacterium, implicated in gynecological and urological disorders. This 59kDa cytolysis was purified to homogeneity in just one chromatographic step directly from the culture supernatant, a final specific activity up to 1.9 x 106 HU mg-1 being obtained. The toxin-induced lesion on human erythrocytes results from the formation of a pore whose radius is approximately 2.4 nm. The damage is inhibited by osmotic protectants and shows a sigmoidal dose-response profile suggesting an aggregation process of haemolysin molecules on the target membrane to create the functional lesion. The extent and the kinetics of haemolysis are strongly dependent on temperature and an activation energy of 64.0 kJ mol-1has been derived. Lipid membranes can be very efficient inhibitors of Gvh-haemolysis, being able to bind the toxin quite avidly. The inhibitory effect requires the presence of cholesterol and it is stronger when cholesterol is mixed with negatively charged phospholipids rather than with zwitterionic phospholipids, suggesting that a negative surface potential increases the affinity of the toxin for the lipid bilayer. The functional properties of Gvh have been compared with those of Clostridium perfringens thetatoxin (PFO) and Escherichia coli haemolysin (HlyA), which are representative of widespread haemolysins produced by Gram-positive and Gram-negative bacteria, respectively. The toxin shares several features with the family of the so-called 'sulphydryl-activated' cytolysins produced by Gram-positive bacteria, although Gvh does not truly belong to this family, being deactivated by β-mercaptoethanol and being antigenically distinct from them. We report here for the first time the detection in the vaginal fluid of infected women of a specific IgA... [ABSTRACT FROM AUTHOR]

Spindle cell/pleomorphic lipoma is an infrequently seen benign adipose tissue tumor. This tumor, mostly arising from the subcutaneous tissue, usually affects male patients and occurs in back, shoulders, head and neck area. It is rarely localized to dermis. Cutaneous spindle cell/pleomorphic lipoma differs from its subcutaneous counterpart by wider anatomical distribution, female predilection and infiltrative margins. We here present a pedunculated type, cutaneous pleomorphic lipoma case localized to the nasolabial region of 59-year-old man. Gurel D, Kargı A, Lebe B. Pedunculated cutaneous spindle cell/pleomorphic lipoma. [ABSTRACT FROM AUTHOR]

The article discusses on cell-wall-less bacterial variants or L-forms. The study of L-forms proved to be significant specifically because of its effect on the human health where its formation is a consequence of specific antibiotic treatments and its potential involvement in persistent and relapsing infections. Recent observations led by Richard d'Ari suggests that E.coli L-forms induced by beta-lactam antibiotics contain small amounts of peptidoglycan, which is essential in cell division.

Purpose: To analyse retrospectively 32 cases of pleomorphic adenoma of the lacrimal gland diagnosed over a 10-year period in a tertiary referral eye centre from North India.Methods: The clinical features of 32 cases of pleomorphic adenomas diagnosed between 1991 and 2000 were analysed and the histopathological features reviewed light microscopically.Results: Among the clinical features, a marked male predominance with younger age of presentation and left-sided dominance was noted. The duration of symptoms was less than 10 months in 28% cases. Histopathologically, the features included presence of cystic degeneration (15.6%) and squamous metaplasia (18.7%). Calcification, osteoid formation and malignant transformation (3.1% each) were occasionally observed.Conclusions: Pleomorphic adenomas of the lacrimal gland may present with duration of symptoms of less than 10 months. Cystic degeneration, squamous metaplasia, calcification or ossification may be observed in lacrimal gland pleomorphic adenomas, as has been described in pleomorphic adenomas of salivary glands. However, the presence of calcification and bone erosion radiologically in a lacrimal gland tumour does not necessarily indicate malignancy. [ABSTRACT FROM AUTHOR]

The article presents information on a study that focuses on isolation of infectious pancreatic necrosis virus from an epizootic occurring in cultured striped bass, morone saxatilis. Histopathological examination of the larvae showed marked multifocal degeneration of the basal layer of the epidermis. Individual cells appeared rounded with pale grey cytoplasmic inclusions and many cells were pleomorphic. Also , the study showed the presence of a mild to moderate pancreatic inflammation characterized by interstitial infiltrates of mononuclear cells around foci of necrotic pancreatic acini.

Malakoplakia is a rare, chronic disease with pleomorphic presentation. It occurs most frequently in immunocompromised patients. It is believed that this entity represents an unusual response to bacterial infection in which macrophages fail to phagocytose them properly. It involves many organs, particularly the urinary and gastrointestinal tracts. It is uncommon on the skin and less common in children. The diagnosis is usually based on histopathologic findings. [ABSTRACT FROM AUTHOR]

The diatom Phaeodactylum tricornutum Bohlin is known to be pleomorphic. Previously it was considered that growth on medium solidified with agar produced ovate cells, whereas growth in liquid medium gave rise to fusiform cells. We have shown that ovate cells can be propagated in liquid medium if the calcium content of the medium is below 15 mg/liter. If the concentration of calcium is raised, fusiform cells develop. [ABSTRACT FROM AUTHOR]