Paraneoplastic cerebellar degeneration secondary to ovarian carcinosarcoma: a cerebellar conundrum.

We present a case of an elderly female patient who presented with a 6-month history of progressive slurred speech, vertigo, unsteadiness and falls. She underwent an extensive battery of neurological and cardiovascular investigations, none of which demonstrated a diagnostic cause for her symptoms. She was referred to the stroke and neurology teams and was started on treatment for presumed anxiety. As her symptoms continued to progress, she was referred to the falls service. Following a multidisciplinary team discussion, she was reviewed by the consultant geriatrician who felt this may be due to a malignancy so the consultant geriatrician arranged blood testsand CT scan of her chest, abdomen and pelvis. These demonstrated a large left adnexal mass and a raised Ca-125 level. The patient was diagnosed with an ovarian tumour, which was treated surgically. A provisional diagnosis of paraneoplastic cerebellar degeneration, secondary to ovarian carcinosarcoma, was made.

Stochasticity of manganese superoxide dismutase mRNA expression in breast carcinoma cells by molecular beacon imaging.

Visual and quantitative monitoring of cell-to-cell variation in the expression of manganese superoxide dismutase (MnSOD) mRNA by using novel ratiometric imaging with molecular beacons (MB) reveals a distinct change in patterns following induction of human breast-carcinoma cells with lipopolysaccharide. Interestingly, the pattern of cell-to-cell variation in a cell line stably transfected with a plasmid bearing a cDNA clone of MnSOD and overproducing the enzyme is significantly different from the pattern associated with MnSOD induction. The levels and the patterns of cell-population heterogeneity for beta-actin mRNA expression do not show distinct changes either following induction or in stably transfected cells. These results are significant in light of the reported relationship between this enzyme and malignant phenotype of breast-carcinoma cells. Use of MBs in ratiometric image analyses for cytoplasmic mRNAs represents a novel means of directly examining the stochasticity of transcription of MnSOD and other genes implicated in cellular phenotype regulation.

Synthetic DNA aptamers to detect protein molecular variants in a high-throughput fluorescence quenching assay.

Real-time protein detection in homogeneous solutions is necessary in many biotechnology and biomedical studies. The recent development of molecular aptamers, combined with fluorescence techniques, may provide an easy and efficient approach to protein elucidation. This report describes the development of a fluorescence-based assay with synthetic DNA aptamers that can detect and distinguish molecular variants of proteins in biological samples in a high-throughput process. We used an aptamer with high affinity for the B chain of platelet-derived growth factor (PDGF), labeled it with a fluorophore and a quencher at the two termini, and measured fluorescence quenching by PDGF. The specific quenching can be used to detect PDGF at picomolar concentrations even in the presence of serum and other cell-derived proteins in cell culture media. This is the first successful application of a synthetic aptamer for the detection of tumor-related proteins directly from the tumor cells. We also show that three highly related molecular variants of PDGF (AA, AB, and BB dimers) can be distinguished from one another in this single-step assay, which can be readily adapted to a microtiter plate assay for high-throughput analysis. The use of fluorescence quenching as a measure of binding between the DNA probe and the target protein eliminates potential false signals that may arise in traditional fluorescence enhancement assays as a result of degradation of the DNA aptamer by contaminating nucleases in biological specimens. This assay is applicable to proteins that are not naturally DNA binding. The excellent specificity, ultrahigh sensitivity, and simplicity of this one-step assay addresses a growing need for high-throughput methods that detect changes in the expression of gene products and their variants in cell cultures and biological specimens.