Loss of the Parkinson's disease-linked gene DJ-1 perturbs mitochondrial dynamics.

Growing evidence highlights a role for mitochondrial dysfunction and oxidative stress as underlying contributors to Parkinson's disease (PD) pathogenesis. DJ-1 (PARK7) is a recently identified recessive familial PD gene. Its loss leads to increased susceptibility of neurons to oxidative stress and death. However, its mechanism of action is not fully understood. Presently, we report that DJ-1 deficiency in cell lines, cultured neurons, mouse brain and lymphoblast cells derived from DJ-1 patients display aberrant mitochondrial morphology. We also show that these DJ-1-dependent mitochondrial defects contribute to oxidative stress-induced sensitivity to cell death since reversal of this fragmented mitochondrial phenotype abrogates neuronal cell death. Reactive oxygen species (ROS) appear to play a critical role in the observed defects, as ROS scavengers rescue the phenotype and mitochondria isolated from DJ-1 deficient animals produce more ROS compared with control. Importantly, the aberrant mitochondrial phenotype can be rescued by the expression of Pink1 and Parkin, two PD-linked genes involved in regulating mitochondrial dynamics and quality control. Finally, we show that DJ-1 deficiency leads to altered autophagy in murine and human cells. Our findings define a mechanism by which the DJ-1-dependent mitochondrial defects contribute to the increased sensitivity to oxidative stress-induced cell death that has been previously reported.

A functional outcome study comparing total ankle arthroplasty (TAA) subjects with pain to subjects with absent level of pain by means of videofluoroscopy.

BACKGROUND: Total ankle arthroplasty (TAA) subjects often suffer pain on the anteromedial side of their ankle joint. Whether this prevalent pain is caused by a changed motion pattern of the TAA is unclear. Therefore, this study assessed the kinematic differences in the motion of the TAA components during gait, comparing TAA subjects with elevated versus absent levels of pain. METHODS: Eleven TAA subjects (5 with pain vs. 6 without pain), all with unilateral Mobility™ TAA and at least two years post-operation, were recruited and stratified based on standard clinical assessed patient data. The 3D motion of the TAA was assessed by means of videofluoroscopy during level, uphill and downhill walking. RESULTS: The hypothesis that the pain group shows a different kinematic motion pattern than the no pain group could not be confirmed. CONCLUSIONS: The same kinematic motion pattern causes pain in some patients, but not in others. Further investigation concerning ligament stresses is needed.

[Total ankle replacement in rheumatoid arthritis]. / Sprunggelenkprothese bei chronischer Polyarthritis.

Rheumatoid arthritis is a systemic disease directly involving multiple joints and indirectly damages bone due to specific medicinal therapy. When deciding on the optimal surgical treatment of inflammatory ankle arthritis (fusion versus arthroplasty), specific factors have to be considered. This review discusses the advantages and disadvantages of total ankle arthroplasty for patients with rheumatoid arthritis and highlights important surgical aspects related to this disease.

[Total ankle arthroplasty with simultaneous subtalar fusion]. / Endoprothese des oberen Sprunggelenks mit simultaner Subtalararthrodese.

OBJECTIVE: Pain free weight bearing ability with orthograde hindfoot position and preserved tibiotalar motion. INDICATIONS: Symptomatic arthritis of the ankle and subtalar joint, additional subtalar hindfoot malalignment. CONTRAINDICATIONS: Absolute: acute infection, noncorrectable ligamentous instability or bony defects, restricted perfusion, diabetic foot syndrome. Relative: inability to comply with postoperative partial weight bearing, only moderate symptoms of subtalar arthritis, smoking, intricate soft tissue situation. SURGICAL TECHNIQUE: Lateral approach to the subtalar joint. Removal of residual cartilage. The joint surfaces are deeply feathered while preserving anatomic congruency. Now tibia and talus are prepared for implantation of a total ankle arthroplasty via an anterior approach. With trial implants in the ankle joint, hindfoot position is evaluated and, if necessary, corrected. Definite fixation of the subtalar joint with 5-10° valgus by one or more compression screws. Final check of ligamentous balance of the ankle and implantation of the definite components. POSTOPERATIVE MANAGEMENT: Immobilization in a cast for 1 week, then removable walker boot for another 5 weeks with partial weight bearing (15 kg) and mobilization in the sagittal plane under physiotherapeutic instruction. With radiologic proof of consolidation weight bearing can be allowed after 6 weeks, with cortical iliac crest bone graft after 8 weeks. RESULTS: From 1998-2016, 41 total ankle replacements with simultaneous isolated subtalar fusion were performed. The consolidation rate was 92.6%. The mean AOFAS Ankle-Hindfoot Score rose from 51.6 preoperatively to 79.7 one year postoperatively. The mean total range of motion (ROM) was 32.3° (range 14-50°) one year after surgery.

Pleomorphic adenoma, I: Ultrastructural organization of "epithelial" regions.

Twenty-four major and minor salivary gland pleomorphic adenomas were studied ultrastructurally to determine the growth patterns, organization, and cytologic modifications of the proliferating neoplastic cells. In compact and highly cellular regions, two cell types--luminal epithelial and myoepithelial--could often be identified; their organization mimicked that of the normal salivary gland duct or acinar unit. Results of the study indicate that the principal proliferating tumor cell is a structurally modified myoepithelial cell that frequently shows squamous differentiation. At the immediate margins of cellular regions of many tumor cells, gradual dedifferentiation of modified myoepithelial cells with a loss of squamous features occurs, although in some cells the squamous features are retained to varying degrees. Within cellular regions, the earliest development of matrix occurs in relation to small, basal lamina-lined extracellular spaces between myoepithelial-like cells. Modifications of such intercellular spaces are helpful in tracing the development of myxoid zones and the evolution of cell types in this unique region. The authors postulate that salivary gland pleomorphic adenomas result from the neoplastic transformation of the complete ductal-acinar unit rather than from one particular ductal "reserve" cell.

Pleomorphic adenoma, II: Ultrastructural organization of "stromal" regions.

Findings from an ultrastructural study of 24 major and minor salivary gland pleomorphic adenomas suggest that the principal cell type in the myxoid and chondromyxoid regions of these tumors is a structurally modified myoepithelial cell. This interpretation is based on findings in the transitional zone between myxoid regions and compact cellular areas that have a ductal-acinar organization, that is, are composed of luminal epithelial and modified myoepithelial cells. Survey-type low-power electron micrographs allowed appreciation of the original orientation of the major proliferating component of these tumors to the perimeter of ductal-acinar units. The low-power electron micrographs also revealed residual features of this organization, the early development and subsequent sequential alteration of matrix compartments as tumor cells became increasingly separated by extracellular products, and a variety of myoepithelial cell modifications, such as squamous and chondroid metaplasia, resulting from neoplastic induction. According to the authors' interpretation, modified myoepithelial cells in myxoid and chondromyxoid regions form a continuum with similar tumor cells in transitional and solid areas, forming what can be visualized as markedly expanded and merging ductal-acinar units that tend to converge with similarly altered adjacent neoplastic ductal-acinar units. Thus, a multiplicity of processes are involved in the formation of the complex and varied histologic patterns that characterize pleomorphic adenomas.

Characterization of epimyoepithelial islands in benign lymphoepithelial lesions of major salivary gland: an immunohistochemical and ultrastructural study.

Knowledge of the processes leading to the development of epimyoepithelial islands bears on histogenetic and morphogentic processes in salivary gland tumors. Immunohistochemical and ultrastructural investigations of the cellular composition of epimyoepithelial islands were carried out on three examples of benign lymphoepithelial lesions with varying histologic features. The monoclonal anti-keratin antibody 312C8-1, which specifically decorates myoepithelial cells of the normal salivary gland, also stains the myoepithelial cells surrounding residual acini and intercalated ducts in benign lymphoepithelial lesions and the cell population of epimyoepithelial islands, with the exception of persisting luminal epithelial cells. Ultrastructurally, the myoepithelial cells of involuting acini and ducts and the modified myoepithelial cells of epimyoepithelial islands, identified in both locations by the monoclonal antibody 312C8-1, show an increasing complement of tonofilament bundles. In addition, persisting lumens (often distended with lymphocytes) and definite luminal epithelial cells can be seen in electron micrographs of some epimyoepithelial islands. The designation for this characteristic epithelial feature of benign lymphoepithelial lesions is therefore appropriate.

Light and electron microscopy of the pagetoid spread of germ cell carcinoma in the rete testis: morphologic evidence suggestive of field effect as a mechanism of tumor spread.

The purpose of this study is to investigate the mechanism of tumor spread in the pagetoid spread of germ cell tumors in the rete testis (PSRT). Twenty consecutive cases of germ cell tumor of the testis (9 seminomas, 3 embryonal carcinomas, and 8 teratocarcinomas) were retrieved to identify the cases with PSRT. The areas of pagetoid spread were examined by the serial sectioning of the entire thickness of the tissue block. Available fresh tissue was submitted for electron microscopic study. Ten cases were associated with PSRT and had focal or extensive areas of intratubular germ cell neoplasia (IGCN) in the proximity of the tumor and the rete testis (RT). In the remaining 10 cases, 6 were associated with IGCN distant from the RT and the last 4 were not associated with IGCN. Seminiferous tubules with IGCN were seen connecting with the RT with pagetoid spread. Isolated single intraepithelial tumor cells also were identified at the periphery of the areas with PSRT. Electron microscopic study of the RT of 4 cases with PSRT (2 seminomas, 1 embryonal carcinoma, and 1 teratocarcinoma) revealed desmosome-type junctions between tumor cells with RT epithelial cells. Direct tumor expansion and cell motility as mechanisms of tumor spread in PSRT does not explain the presence of isolated cells and desmosome-type junctions of the tumor cells as demonstrated in this study. The authors believe that the field effect plays an important part in the pathogenesis of this pagetoid spread in the RT. It is likely that this field effect is induced by the germ cell tumor and is operated through the immature germ cells or undifferentiated epithelial cells in the RT adjacent to the tumor cells.

Differentiating neuroblastoma of pituitary gland: neuroblastic transformation of epithelial adenoma cells. Case report.

The authors report the case of a 40-year-old woman with a 12-year history of irregular menses, amenorrhea, infertility, galactorrhea, a slightly elevated prolactin level, and a slowly growing pituitary adenoma. She developed recent onset of visual symptoms, prompting craniotomy for removal of an intrasellar tumor. Following surgery, her vision and prolactin levels returned to normal. Light microscopic and immunohistochemical examination of the tumor revealed it to be a neuroblastoma, which was immunohistochemically positive for synaptophysin, S-100 protein, and oxytocin. The neoplasm contained prolactin-positive neuroblastic and pituitary epithelial cells. No other pituitary hormones were found. Electron microscopy demonstrated two cell types: one with frequent neuritic processes containing neurosecretory granules and showing synaptic specialization, and another one compatible with epithelial adenohypophyseal cells. A few cells had ultrastructural features that were transitional between neuronal cells and granulated epithelial cells. Agranular folliculostellate cells were also identified. Immunoelectron microscopy demonstrated prolactin granules in the cytoplasm of the epithelial cells, in a few transitional cells, and in scattered neuritic processes. Ultrastructural and immunohistochemical features of the tumor suggested a transformation of pituitary epithelium to neuroblastic cells. Hyperprolactinemia and associated clinical symptoms may in part be attributed to selective prolactin secretion by neoplastic cells that were differentiating into adenomatous pituitary cells and, to a lesser extent, to cells differentiating into a neuroblastic line. Compression of pituitary stalk might also have been a contributory factor to the increased prolactin levels. Moreover, the oxytocin produced by the neuroblastic cells was considered an additional stimulus for prolactin secretion by neoplastic cells or by the normal pituitary.

Evaluation of apoptosis in four human tumour cell lines with differing sensitivities to cisplatin.

Four human tumour cell lines were evaluated for their ability to undergo apoptosis when subjected to cisplatin or hyperthermia treatment. In an ovarian carcinoma line (A2780s) and its derivative cisplatin resistant line (A2780cp) the variation in response was expressed for both the colony survival endpoint and the apoptosis endpoint. Apoptosis was measured by the number of floating cells, DNA agarose gels, and electron microscopy. In fact, cisplatin resistance was expressed to a higher level for apoptosis, than colony survival in the A2780cp cell line compared to the A2780s line. The melanoma cell line (Sk Mel-3) also showed induced apoptosis by cisplatin treatment while the glioma line (U87MG) showed little to no apoptosis in response to cisplatin treatment. Hyperthermia (43 degrees C for 1 hour) induced apoptosis in the human melanoma cell line but not in the glioma cell line. These data indicate that, while both cisplatin and hyperthermia can induce apoptosis in human tumour cell lines, the degree of induction is highly cell line dependent.

Unusual immunostaining pattern of chromogranin in normal urothelium and in transitional cell neoplasms.

We report an unusual pattern of immunostaining for chromogranin A in 24 transitional cell carcinomas (TCC). Positive immunostaining was seen with chromogranin A antisera in 10 of 16 urinary bladder TCC, neither of 2 prostatic TCC, 3 of 3 ureteral TCC and 2 of 3 metastatic TCC. This staining was demonstrated within the cytoplasm of transitional cells at all levels of the neoplastic epithelium, including cells near the basement membrane and at the free surface (umbrella cells). In 5 of 7 cases there was also immunoreactivity of the non-neoplastic urothelium. Immunostaining with neuron-specific enolase and synaptophysin was negative in all of these cases and no neuro-secretory granules were identified in 7 cases examined by electron microscopy. This pattern of immunostaining is probably due to reactivity with chromogranins or certain chromogranin-like proteins in the transitional cells, particularly in the umbrella cells.

Diagnostic value of microvillus-matrix associations in tumors.

Until now microvillus-matrix associations have been reported to occur only in mesotheliomas and hence this phenomenon is thought to be of value in distinguishing mesothelioma from pulmonary adenocarcinoma. We report here the occurrence of microvillus-matrix associations in two pulmonary adenocarcinomas which reduces the value of this phenomenon in the differential diagnosis of these tumors.

Promyelocytic leukaemia-immunoreactive neuronal intranuclear rodlets in the human brain.

In a previous study, we demonstrated immunoreactivity of a subset of neuronal intranuclear rodlets (INRs) in the human substantia nigra for promyelocytic leukaemia (PML) protein, the signature protein of PML bodies. In the present study, we extend these observations and describe the ultrastructural features, immunohistochemical staining characteristics, and topographical pattern of distribution of PML-immunoreactive intranuclear rodlets (PML-INRs). Consistent with a purported role for PML bodies in nuclear proteolysis and/or transcriptional regulation, PML-INRs are immunoreactive for components of the ubiquitin-proteasome system, the transcriptional regulator CREB-binding protein, acetylated histone H4, and the eukaryotic translation initiation factor eIF4E. Immunoelectron microscopy reveals that they all possess a filamentous core and, in some, this is surrounded by a granular shell. We further demonstrate that a proportion of INRs in extranigral sites also show partial immunoreactivity for PML. These observations indicate an intimate association between two neuronal nuclear bodies, PML bodies and INRs. Because both of these structures have been implicated in neurodegenerative disease, PML-INRs may provide a tool with which to study changes in nuclear substructure in disease.

Reliability of criteria for ultrastructural identification of neuroendocrine granules.

For full diagnostic use to be made of the neurosecretory granule, the range of sizes, forms, and staining qualities for this cytoplasmic organelle, along with the extent of its expression in various neoplasms, must be established. Neurosecretory type granules occasionally occur in nonneuroendocrine tumors. A series of carcinoids of the lung provides a model for assessing the morphologic types of cytoplasmic granules identified by antibodies to chromogranin A and immunogold labeling. The results show that granule structure in tumors is pleomorphic. Despite having sizes within the expected range, many labeled and, indeed, unlabeled secretory granules are atypical, particularly in structural form. Cell-to-cell variation in the proportion of even typical neurosecretory granules labeling for chromogranin A is the rule. Studies correlating biochemical, immunohistochemical, electron microscopic, and perhaps in situ hybridization characteristics are required to define better the criteria for unequivocal identification of neurosecretory granules in tumors.

Primary intracranial pleomorphic angioleiomyoma--a new morphologic variant. An immunohistochemical and electron microscopic study.

BACKGROUND: Angioleiomyomas usually are benign subcutaneous neoplasms that occur most often in extremities of middle-aged individuals. Very few cases have been described in other locations; none along the neuroaxis. An intracranial example of angioleiomyoma displaying unusual morphologic features not seen in the typical peripheral variants of this tumor is described. METHODS: The tumor was studied with conventional histology, immunohistochemistry with morphometric calculation of proliferation index, immunoelectron microscopy, and DNA flow cytometry. RESULTS: The tumor was composed of large epithelioid and pleomorphic cells filled with intermediate filaments positive for desmin and vimentin. Scattered cells also expressed myosin and muscle-specific actin. Smooth muscle cell differentiation was confirmed by ultrastructural demonstration of subplasmalemmal dense bodies, attachment plaques, and discontinuous basal lamina. The proliferation index with proliferating cell nuclear antigen (PCNA) monoclonal antibody was 75.78%, whereas it was only 4.22% with Ki67 monoclonal antibodies adopted to paraffin material (MIB-1). CONCLUSION: The tumor represents a unique morphologic variant of a pleomorphic angioleiomyoma. Cellular pleomorphism and a strong reaction for PCNA in numerous cells suggested that the lesion was malignant. However, the absence of mitotic figures, a small number of Ki-67-positive cells, a diploic DNA pattern, and a low proliferation index in flow cytometry all supported the concept that this neoplasm represented an unusual histologic variant of benign angiogenic leiomyoma. Encapsulation and demarcation of the surgical specimen and the survival of the patient for more than 4 years without recurrence after resection support this interpretation.

Low magnification transmission electron microscopy in diagnostic pathology.

Transmission electron microscopy examination of selected diagnostic specimens, that is, renal and nerve biopsies, can be greatly facilitated by the implementation of slot grid preparations that are inherently devoid of any grid bars. Such preparations are conducive to screening and photography at both low and intermediate modes of magnification without any apparent loss of resolution. The use of this technique in diagnostic electron microscopy is simplified by sequential en bloc staining with both uranyl and lead salts.

Compression arthrodesis of the rheumatoid ankle and hindfoot.

The reported frequency of involvement of the rheumatoid ankle and hindfoot varies between 9% and 70%. Fusion of the ankle joint, the subtalar, talonavicular, or calcaneocuboidal joint (Chopart's joint) or all of them is the preferred method of treatment for severe rheumatoid involvement causing pain, instability, and/or severe deformity. Ankle arthroplasty is indicated rarely. Pantalar arthrodesis is performed more frequently than talonavicular fusion or ankle fusion. Reported rates of fusion after compression arthrodesis of the ankle joint vary from 65% to 90%, averaging 80% to 85%. Higher success rates of as high as 95% were obtained with internal lag screw fixation as proposed by Wagner. The result of various combinations of arthrodesis (n = 54) of the ankle joint, the subtalar joint, and Chopart's joint in 43 patients with rheumatoid arthritis operated on in a 10-year period from 1984 through 1993 are presented. In all cases internal fixation by lag screws according to Wagner was used with a modified lateral approach incorporating osteotomy of the distal fibula. The technique is described in detail. Solid fusion was obtained in 21% of the cases after 8 weeks, in 9% of the cases after 12 weeks, and in 92% of the cases after 16 weeks. In 8% (3 patients) revision because of delayed union or nonunion eventually led to bony fusion. Postoperative pain, walking capacity, gait, and the subjective outcome were assessed. Complications occurred in 16%, revision was performed in 11.6% of the cases; in all cases healing was obtained. Overall patient satisfaction was 93%.

Angiogenic histogenesis of stromal cells in hemangioblastoma: ultrastructural and immunohistochemical study.

Controversy regarding the origin of characteristic stromal cells (SC) is responsible for the placement of hemangioblastoma as a single entity in the category of "tumors of uncertain histogenesis" in the current WHO classification of brain tumors. This subclassification of hemangioblastoma is, to a large extent, a consequence of a remarkable antigenic heterogeneity of SC demonstrated in many, often contradictory immunohistochemical studies. In contrast, most of the electron microscopic studies demonstrated a number of features indicating angiogenic nature of SC and, therefore, hemangioblastoma. This study reevaluated the histogenesis of SC, applying immunohistochemistry as well as electron microscopy and immunoelectron microscopy. Immunohistochemical studies confirmed most of the previous results indicating a very frequent expression of vimentin, S-100 protein, neuron-specific enolase, and cytokeratins. SC were less commonly immunoreactive for desmin, factor XIIIa, and Ricinus communis lectin receptors, and only occasionally for factor VIII and Ulex europeus lectin. They were negative for other markers of endothelial, neuronal, glial, neuroendocrine, and smooth muscle differentiation. Approximately 1% of SC showed Ki67 immunoreactivity, indicating their slight proliferative activity, consistent with the benign nature of the tumor. In contrast to the inconclusive results of the immunohistochemistry, electron microscopy demonstrated a clear relationship of SC to endothelial cells, smooth muscle cells, and pericytes. Occasional SC were found within the vascular lumina. SC often showed intracellular caveolae consistent with the formation of early capillary lumina. Moreover, occasional SC contained small Weibel-Palade bodies positive for factor VIII in immunoelectron microscopy. SC represent a heterogeneous population of abnormally differentiating mesenchymal cells of angiogenic lineage, with some morphological features of endothelium, pericytes, and smooth muscle cells. Occurrence of SC in hemangioblastoma could be related to a limited ability of angioformative stromal cells to develop an architecture of capillary lumina integrated with the vascular network of the tumor. Hemangioblastoma should be reclassified and included together with other vascular tumors of the central nervous system.

Myopathy with hexagonally cross-linked tubular arrays: a new autosomal dominant or sporadic congenital myopathy.

We describe a slowly progressive myopathy with unique crystalloid inclusions in type 2 muscle fibers in a father and his son, as well as one more unrelated individual. The inclusions were strongly eosinophilic and purple by the Gomori method. They were composed of vesicular profiles, approximately 20 nm in cross-diameter, connected by radially arranged double spokes arising at 60 degrees angles. The inclusions were not related to any normal cellular organelle. Extensive immunohistochemical studies failed to reveal their chemical nature. It is suggested that this is a new congenital myopathy with characteristic intracytoplasmic inclusions, occurring sporadically or with an autosomal dominant pattern of inheritance.

Immunoelectron microscopy of Rosenthal fibers.

Seventeen intracerebral gliomas containing Rosenthal fibers (RF) were studied by an immunoperoxidase method for localization of ubiquitin (UB), glial fibrillary acidic protein (GFAP), desmin and vimentin (VIM). The majority of RF showed an immunohistochemically negative core surrounded by a ring of overlapping reactions for UB, GFAP and VIM. Many RF were entirely negative for UB and intermediate filaments (IF). Immunoelectron microscopic localization of UB and GFAP was performed on seven selected tumors. UB was found in all RF and on IF in the proximity of RF. GFAP reaction was localized on astrocytic IF, including those trapped within RF, and within the granular component of some RF. In contrast to the light microscopic studies, neither GFAP- nor UB-negative RF were found on immunoelectron microscopy. VIM reaction on IF and a few RF was demonstrated in one tumor processed at low temperature into Lowicryl; it was much weaker than that for GFAP. Many cells with RF contained lysosome-like inclusions with material displaying electron density similar to adjacent RF; few of these inclusions were reactive for UB. It is concluded that RF formation is associated with ubiquitination of astrocytic IF. GFAP- and VIM-immunoreactive IF and products of their disintegration contribute to RF material. It is also suggested that the lysosomal system of astrocytes partially degrades RF.