Maria Gardberg

Diagnostic accuracy of parkinsonism syndromes by general neurologists

INTRODUCTION Movement disorder specialists can achieve a high level of accuracy when clinically diagnosing parkinsonism syndromes. However, data about the diagnostic accuracy among general neurologists is limited. OBJECTIVES This study investigated the recent diagnostic accuracy of parkinsonism syndromes by general neurologists. METHODS A retrospective examination of 1362 post-mortem cases diagnosed in the years 2000-2012 by neuropathologists was performed. Out of these cases, we identified 111 patients who received a clinical parkinsonism diagnosis during life and 122 patients who received a neuropathological diagnosis of a parkinsonism syndrome post-mortem including 11 incidental cases. RESULTS Fifty-eight (75.3%) of the 77 patients who had received clinical Parkinsons disease (PD) diagnoses were confirmed after the neuropathological examination. The sensitivity of the clinical diagnosis for idiopathic Parkinsons disease (PD) was 89.2% and the specificity was 57.8%. The corresponding numbers for progressive supranuclear palsy (PSP) were 52.9% and 100%, and for multiple system atrophy (MSA) were 64.3% and 99.0%, respectively. CONCLUSIONS Parkinsons disease is heavily overdiagnosed by general neurologists, whereas parkinsonism plus syndromes are underdiagnosed. Despite improvements in the diagnostic methods during recent decades and the development of diagnostic clinical criteria for parkinsonian syndromes, the diagnostic accuracy of Parkinsons disease remains relatively low, and 1/4 of diagnoses are incorrect.

FHOD1, a Formin Upregulated in Epithelial-Mesenchymal Transition, Participates in Cancer Cell Migration and Invasion

Cancer cells can obtain their ability to invade and metastasise by undergoing epithelial-to-mesenchymal transition (EMT). Exploiting this mechanism of cellular plasticity, malignant cells can remodel their actin cytoskeleton and down-regulate proteins needed for cell-cell contacts. The mechanisms of cytoskeletal reorganisation resulting in mesenchymal morphology and increased invasive potential are poorly understood. Actin nucleating formins have been implicated as key players in EMT. Here, we analysed which formins are altered in squamous cell carcinoma related EMT. FHOD1, a poorly studied formin, appeared to be markedly upregulated upon EMT. In human tissues FHOD1 was primarily expressed in mesenchymal cells, with little expression in epithelia. However, specimens from oral squamous cell cancers demonstrated consistent FHOD1 upregulation in mesenchymally transformed cells at the invasive edge. This upregulation was confirmed in an oral squamous carcinoma model, where FHOD1 expression was markedly increased upon EMT in a PI3K signalling dependent manner. In the EMT cells FHOD1 contributed to the spindle-shaped morphology and mesenchymal F-actin organization. Furthermore, functional assays demonstrated that FHOD1 contributes to cell migration and invasion. Finally, FHOD1 depletion reduced the ability of EMT cancer cells to form invadopodia and to degrade extracellular matrix. Our results indicate that FHOD1 participates in cytoskeletal changes in EMT. In addition, we show that FHOD1 upregulation occurs during cancer cell EMT in vivo, which indicates that FHOD1 may contribute to tumour progression.

Characterization of Diaphanous-related formin FMNL2 in human tissues

BackgroundDiaphanous-related formins govern actin-based processes involved in many cellular functions, such as cell movement and invasion. Possible connections to developmental processes and cellular changes associated with malignant phenotype make them interesting study targets. In spite of this, very little is known of the tissue distribution and cellular location of any mammalian formin. Here we have carried out a comprehensive analysis of the formin family member formin -like 2 (FMNL2) in human tissues.ResultsAn FMNL2 antibody was raised and characterized. The affinity-purified FMNL2 antibody was validated by Western blotting, Northern blotting, a peptide competition assay and siRNA experiments. Bioinformatics-based mRNA profiling indicated that FMNL2 is widely expressed in human tissues. The highest mRNA levels were seen in central and peripheral nervous systems. Immunohistochemical analysis of 26 different human tissues showed that FMNL2 is widely expressed, in agreement with the mRNA profile. The widest expression was detected in the central nervous system, since both neurons and glial cells expressed FMNL2. Strong expression was also seen in many epithelia. However, the expression in different cell types was not ubiquitous. Many mesenchymal cell types showed weak immunoreactivity and cells lacking expression were seen in many tissues. The subcellular location of FMNL2 was cytoplasmic, and in some tissues a strong perinuclear dot was detected. In cultured cells FMNL2 showed mostly a cytoplasmic localization with perinuclear accumulation consistent with the Golgi apparatus. Furthermore, FMNL2 co-localized with F-actin to the tips of cellular protrusions in WM164 human melanoma cells. This finding is in line with FMNL2s proposed function in the formation of actin filaments in cellular protrusions, during amoeboid cellular migration.ConclusionFMNL2 is expressed in multiple human tissues, not only in the central nervous system. The expression is especially strong in gastrointestinal and mammary epithelia, lymphatic tissues, placenta, and in the reproductive tract. In cultured melanoma cells, FMNL2 co-localizes with F-actin dots at the tips of cellular protrusions.

Dopamine transporter imaging does not predict the number of nigral neurons in Parkinson disease

Objective: To examine possible associations between in vivo brain dopamine transporter SPECT imaging and substantia nigra pars compacta (SNc) neuronal survival in Parkinson disease (PD). Methods: Nigral neuron numbers were calculated for 18 patients (11 patients with neuropathologically confirmed PD) who had been examined with dopamine transporter (DAT) SPECT before death. Correlation analyses between SNc tyrosine hydroxylase (TH)–positive and neuromelanin-containing neuron counts and DAT striatal specific binding ratios (SBRs) were performed with semiquantitative region of interest–based and voxel-based analyses. Results: Mean putamen SBR did not correlate with the number of substantia nigra TH-positive (r = −0.11, p = 0.66) or neuromelanin-containing (r = −0.07, p = 0.78) neurons. Correlations remained clearly nonsignificant when the time interval between SPECT and death was used as a covariate, when the voxel-based analysis was used, and when only patients with PD were included. Conclusions: This cohort study demonstrates that postmortem SNc neuron counts are not associated with striatal DAT binding in PD. These results fit with the theory that there is no correlation between the number of substantia nigra neurons and striatal dopamine after a certain level of damage has occurred. Striatal DAT binding in PD may reflect axonal dysfunction or DAT expression rather than the number of viable neurons.

Comparison of Somatostatin Receptor 2-Targeting PET Tracers in the Detection of Mouse Atherosclerotic Plaques

PurposeRupture-prone atherosclerotic plaques are characterized by accumulation of macrophages, which have shown to express somatostatin type 2 receptors. We aimed to investigate whether somatostatin receptor-targeting positron emission tomography (PET) tracers, [68Ga]DOTANOC, [18F]FDR-NOC, and [68Ga]DOTATATE, can detect inflamed atherosclerotic plaques.ProceduresAtherosclerotic IGF-II/LDLR−/−ApoB100/100 mice were studied in vivo and ex vivo for tracer uptake into atherosclerotic plaques. Furthermore, [68Ga]DOTANOC and [68Ga]DOTATATE were compared in a head-to-head setting for in vivo PET/X-ray computed tomography (CT) imaging characteristics.ResultsEx vivo uptake of [68Ga]DOTANOC and [68Ga]DOTATATE in the aorta was higher in atherosclerotic mice compared to control C57Bl/6N mice, while the aortic uptake of [18F]FDR-NOC showed no genotype difference. Unlike [18F]FDR-NOC, [68Ga]DOTANOC and [68Ga]DOTATATE showed preferential binding to atherosclerotic plaques with plaque-to-wall ratio of 1.7 ± 0.3 and 2.1 ± 0.5, respectively. However, the aortic uptake and aorta-to-blood ratio of [68Ga]DOTANOC were higher compared to [68Ga]DOTATATE in in vivo PET/CT imaging.ConclusionOur results demonstrate superior applicability for [68Ga]DOTANOC and [68Ga]DOTATATE in the detection of atherosclerotic plaques compared to [18F]FDR-NOC.

Normal dopamine transporter SPECT in neuropathologically confirmed corticobasal degeneration.

The role of dopamine transporter imaging in the diagnosis of corticobasal syndrome (CBS) is unclear. In the largest clinical study so far, Cilia et al. [1] presented data from 36 patients with clinically probable corticobasal degeneration (CBD) with [I]FP-CIT (CIT-SPECT) and compared the results to patients with Parkinson’s disease and healthy controls. Their results showed high variability in dopamine transporter binding, and four of the clinically probable CBD patients had normal scans. As the authors acknowledged, the interpretation of the findings was limited by the lack of pathological confirmation of the diagnoses. There is one previously reported patient with ante mortem CIT-SPECT and post mortem confirmation of CBD diagnosis. O’Sullivan et al. [2] reported a 65-year-old woman who had typical symptoms and a clinical diagnosis of CBD together with normal CIT-SPECT 4 years after clinical onset. Here we report a 70-year-old woman, who was referred to a neurologist in 2006 due to symptoms in her left upper extremity that had started 6 months earlier. She complained that her left arm was making ‘‘strange movements’’ and she was not always aware of where her left arm was. The family history was unremarkable. A 1.5 T MRI scan of the brain in 2006 did not show clinically significant findings. Clinical examination showed bilateral apraxia and mild rigidity in the upper extremities, her left arm moved constantly during examination and there was left-sided dysdiadochokinesia. The patient also had mild hypokinesia and walking slowness. A diagnosis of CBS was suspected. CIT-SPECT was performed approximately 9 months after symptom onset and the striatal binding was visually estimated as normal although a retrospective semi-automated analysis (BRASS, Hermes Medical Solutions, Stockholm, Sweden) showed some asymmetry (Fig. 1a). Two years later the disease had clearly progressed: the patient was unable to walk without help, her left arm was now rigid without involuntary movements, and the right arm was constantly moving during examination. There was flexion contracture in the left hand, general hypokinesia and clear hypomimia and rigidity. Levodopa treatment was initiated at a dose of 300 mg/day. This dose did not have significant effects on clinical symptoms, and the patient died 7 months later before dose increases were possible. At autopsy, acute bronchopneumonia was found to be the immediate cause of death. In the neuropathological examination, the macroscopic findings included cerebral atrophy (brain weight 1,240 g), with the most atrophic gyri present in the frontal lobes. There was pallor of the substantia nigra and locus coeruleus. Microscopic examination showed widespread pathology of the cortex. This included neuronal loss, mild vacuolation and ballooned achromatic neurons. Additionally, astrocytic plaques were present (Fig. 1b). In the substantia nigra, there was a loss of pigmented neurons, and V. Kaasinen (&) M. Paivarinta Division of Clinical Neurosciences, Department of Neurology, University of Turku and Turku University Hospital, POB 52, 20521 Turku, Finland e-mail: valtteri.kaasinen@tyks.fi

Characterization of Leukocyte Formin FMNL1 Expression in Human Tissues

Formins are cytoskeleton regulating proteins characterized by a common FH2 structural domain. As key players in the assembly of actin filaments, formins direct dynamic cytoskeletal processes that influence cell shape, movement and adhesion. The large number of formin genes, fifteen in the human, suggests distinct tasks and expression patterns for individual family members, in addition to overlapping functions. Several formins have been associated with invasive cell properties in experimental models, linking them to cancer biology. One example is FMNL1, which is considered to be a leukocyte formin and is known to be overexpressed in lymphomas. Studies on FMNL1 and many other formins have been hampered by a lack of research tools, especially antibodies suitable for staining paraffin-embedded formalin-fixed tissues. Here we characterize, using bioinformatics tools and a validated antibody, the expression pattern of FMNL1 in human tissues and study its subcellular distribution. Our results indicate that FMNL1 expression is not restricted to hematopoietic tissues and that neoexpression of FMNL1 can be seen in epithelial cancer.

Brain 18F-FDG and 11C-PiB PET findings in two siblings with FTD/ALS associated with the C9ORF72 repeat expansion

The C9ORF72 hexanucleotide expansion is a major pathological expansion pattern found in patients with frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (C9FTD/ALS). We describe a patient in whom early clinical evaluation, MRI and fluorodeoxyglucose (FDG) positron emission tomography (PET) findings failed to definitively differentiate between FTD and Alzheimer’s disease (AD), whereas 11C-Pittsburgh compound B (PiB) PET was negative for amyloid pathology. He later developed ALS symptoms, and post mortem neuropathological findings were diagnostic of FTD-ALS, while no findings suggested AD. His sister was diagnosed with FTD, and the C9ORF72 expansion was detected in both siblings. We conclude that 11C-PiB PET imaging may help the early differential diagnosis between AD and FTD, including C9FTD/ALS.

FMNL2/FMNL3 formins are linked with oncogenic pathways and predict melanoma outcome

While most early (stage I‐II) melanomas are cured by surgery, recurrence is not uncommon. Prognostication by current clinicopathological parameters does not provide sufficient means for identifying patients who are at risk of developing metastases and in need of adjuvant therapy. Actin‐regulating formins may account for invasive properties of cancer cells, including melanoma. Here, we studied formin‐like protein 2 and 3 (FMNL2 and FMNL3) in melanoma by analysing their role in the invasive properties of melanoma cells and by evaluating whether FMNL2 expression is associated with melanoma outcome. Immunohistochemical characterization of FMNL2 in a cohort of 175 primary cutaneous stage I‐II melanomas indicated that high FMNL2 reactivity correlates with poor outcome as evaluated by recurrence free survival (p < 0.0001) or disease specific survival (p < 0.0001). In multivariate analysis, Breslows thickness (p < 0.05) and FMNL2 expression (p < 0.001) remained as independent prognostic factors. Cellular studies revealed that FMNL2 is a component of filopodia in many melanoma cell lines. Inhibition of either FMNL2 or the closely related FMNL3 affected the maintenance of melanoma cell morphology and reduced migration. Finally, inhibition of the BRAF, PI3K and MAPK oncogenic pathways markedly reduced expression of both FMNL2 and FMNL3 in melanoma cells. The results suggest a major role for FMNL2/FMNL3 formins in melanoma biology and raise the possibility that the novel targeted melanoma drugs may interfere with the cellular properties regulated by these formins.

Somatostatin receptor 2A in gliomas: Association with oligodendrogliomas and favourable outcome

Somatostatin receptor subtype 2A (SSTR2A) is a potential therapeutic target in gliomas. Data on SSTR2A expression in different glioma entities, however, is particularly conflicting. Our objective was to characterize SSTR2A status and explore its impact on survival in gliomas classified according to the specific molecular signatures of the updated WHO classification. In total, 184 glioma samples were retrospectively analyzed for SSTR2A expression using immunohistochemistry with monoclonal antibody UMB-1. Double staining with CD68 was used to exclude microglia and macrophages from analyses. SSTR2A staining intensity and its localization in tumor cells was evaluated and correlated with glioma entities and survival. Diagnoses included 101 glioblastomas (93 isocitrate dehydrogenase (IDH) -wildtype, 3 IDH-mutant, 5 not otherwise specified (NOS)), 60 astrocytomas (22 IDH-wildtype, 37 IDH-mutant, 1 NOS), and 23 oligodendrogliomas (19 IDH-mutant and 1p/19q-codeleted, 4 NOS). SSTR2A expression significantly associated with oligodendrogliomas (79% SSTR2A positive) compared to IDH-mutant or IDH-wildtype astrocytomas (27% and 23% SSTR2A positive, respectively), and especially glioblastomas of which only 13% were SSTR2A positive (p < 0.001, Fishers exact test). The staining pattern in glioblastomas was patchy whereas more homogeneous membranous and cytoplasmic staining was detected in oligodendrogliomas. Positive SSTR2A was related to longer overall survival in grade II and III gliomas (HR 2.7, CI 1.2–5.8, p = 0.013). In conclusion, SSTR2A expression is infrequent in astrocytomas and negative in the majority of glioblastomas where it is of no prognostic significance. In contrast, oligodendrogliomas show intense membranous and cytoplasmic SSTR2A expression, which carries potential diagnostic, prognostic, and therapeutic value.