Stable isotope dilution ultra-high performance liquid chromatography-tandem mass spectrometry quantitative profiling of tryptophan-related neuroactive substances in human serum and cerebrospinal fluid.

Many compounds related to L-tryptophan (L-TRP) have interesting biological or pharmacological activity, and their abnormal neurotransmission seems to be linked to a wide range of neurodegenerative and psychiatric diseases. A high-throughput method based on ultra-high performance liquid chromatography connected to electrospray tandem mass spectrometry (UHPLC-ESI-MS/MS) was developed for the quantitative analysis of L-TRP and 16 of its metabolites in human serum and cerebrospinal fluid (CSF), representing both major and minor routes of L-TRP catabolism. The combination of a fast LC gradient with selective tandem mass spectrometry enabled accurate analysis of almost 100 samples in 24h.

Tau protein, beta-amyloid₁₋₄₂ and clusterin CSF levels in the differential diagnosis of Parkinsonian syndrome with dementia.

Background: Parkinson's disease (PD), PD with dementia (PDD) and Lewy body dementia (DLB) are synucleinopathies. PDD and DLB are sometimes considered a transition between PD and Alzheimer dementia (AD). Finding in vivo markers or their combination could help in the differential diagnosis of these neurodegenerative (ND) diseases.

Cerebrospinal fluid levels of chromogranin A in the treatment-naïve early stage Parkinson's disease: a pilot study.

Chromogranin A (CgA) levels in cerebrospinal fluid (CSF) have been reported to be significantly reduced in the later stages of Parkinson's disease (PD). There are only limited data regarding its levels in the early stages, so its significance as a potential biomarker in the diagnosis of PD cannot be established. The aim of our study was to establish the level of CgA in a cohort of treatment-naïve patients with early stage PD.

Effect of entacapone on plasma homocysteine levels in Parkinson's disease patients.

Peripheral metabolism of L-DOPA via enzyme catechol-O-methyltransferase (COMT) is one of the possible sources of homocysteine (HCY). The aim of this study was to assess plasma HCY levels in L-DOPA-treated Parkinson's disease (PD) patients and its influence by adding the inhibitor COMT (entacapone). Patients were divided into two groups: (1) patients long term treated with L-DOPA but were naïve to entacapone, (2) L-DOPA naïve patients, in whom a combined treatment with L-DOPA and entacapone was started.

Identification of viscoelastic parameters of skin with a scar in vivo, influence of soft tissue technique on changes of skin parameters.

The goal of the experiment was to develop an identification method capable of objective detection of changes of viscoelastic properties of skin with a scar remaining after a modified radical mastectomy. We compared the intact skin and the skin with a scar, a scar before and after physiotherapy. We used two methods.