Optical coherence tomography in interventional cardiology—Research field or future daily routine?

Nowadays, optical coherent tomography (OCT) as the most precise morphologic technique is used in the increasing number of cases, both in routine clinical situations and research projects. Huang and co-workers reported the first clinical use of the 2-dimensional OCT in 1991, suggesting the principle of its use both in ophthalmology and interventional cardiology. The method has developed rapidly since that time. Interventional cardiologists benefit from its detailed intravascular imaging ability, providing real-time information of the intracoronary pathology. Researchers acknowledge the resolution, allowing detailed analysis of vessel structure. Its axial resolution level is approximately 10–15 μm, which is far from any other method used in interventional cardiology. The review will address the principle of the method and the main fields of the relatively short history of the OCT use as a routine clinical imaging method. We will summarize the main OCT milestones in the research field and its possible future as well. The review will describe OCT as the method under rapid development that should be considered as a new “gold” or even “platinum” standard for the coronary vessels imaging.     

Markedly asymmetric presentation in multiple system atrophy

BackgroundMultiple system atrophy (MSA) presents with fairly symmetrical, levodopa unresponsive parkinsonism and additional features like autonomic dysfunction, cerebellar and corticospinal tract involvement. Marked asymmetry in atypical parkinsonism suggests alternative diagnosis like Corticobasal syndrome (CBS).MethodsWe describe five unusual cases, who presented initially with markedly asymmetric parkinsonism, rigid dystonic abnormal limb posturing and subsequently developed clinical and/or radiological features consistent with probable MSA-P.ResultsUsing the internationally accepted diagnostic criteria, the patients fulfilled the diagnostic criteria for probable MSA-P after 5 years from disease onset. Case 4 and 5 had characteristic MRI features and Case 2 was pathologically confirmed.ConclusionsWe use these cases to highlight that MSA-P MSA-P can present rarely with very marked asymmetry, dystonic limb and myoclonic jerks leading to a diagnosis of CBS at onset.     

Levodopa-induced dyskinesias and continuous subcutaneous infusions of apomorphine: results of a two-year, prospective follow-up.

Twelve patients with levodopa-induced dyskinesias were treated with continuous subcutaneous apomorphine. A markedly significant reduction in peak dose dyskinesias occurred over a two-year follow-up.     

Intracerebral recording of readiness potential induced by a complex motor task.

While exploring 11 epileptic patients with intracerebral electrodes, we recorded readiness potential (RP) preceding a complex motor task. Multilead depth electrodes were positioned stereotactically into the cortex. In three patients, it was also possible to record RP from the putamen. The movement triggering the recording was the turning of a page in an architectural book. The movement was performed under two conditions: in the first condition, without looking at the pictures on the page (typical self-pacing); and in the second condition, following the inspection of the pictures. There were no significant differences in the appearance of RP under these two conditions, neither in duration nor in amplitude. That could be explained by the fact that "self-paced" does not mean "spontaneous," but covers the internal non-conscious program related to a given task. RP were present in the contralateral primary sensorimotor cortex and the bilateral supplementary motor area (SMA), and in the anterior caudal cingulate cortex. No difference between the cortical topography of RP preceding a simple motor task and the topography of RP occurring in connection with complex movement was observed.     

Assessment of the cerebral vasomotor reactivity in internal carotid artery occlusion using a transcranial Doppler sonography and functional MRI.

BACKGROUND AND PURPOSE: Several methods are being used to assess cerebral vasomotor reactivity (CVR), including transcranial Doppler (TCD) sonography and blood oxygenation level-dependent functional magnetic resonance imaging (fMRI). The aim was to assess the correlation of TCD and fMRI in the CVR assessment. METHODS: Study group consisted of 28 patients (24 males, 4 females; aged 30-82, mean 63.1 +/- 10.0 years), presenting with 29 occluded internal carotid arteries. The TCD examination, including breath-holding/hyperventilation test (BH/HV) and breath-holding index (BHI), and fMRI examination were used for the assessment of CVR. fMRI employed a bimanual motor task within both a block paradigm and an event-related paradigm. Cohen's kappa was applied when statistically assessing correlation of the methods. RESULTS: The following correlations were found--between BH/HV and BHI 58.6%, kappa= .205; BH/HV and fMRI 65.5%, kappa= .322; BHI and fMRI 58.6%, kappa= .151; TCD (consistent result of both BH/HV and BHI test) and fMRI 70.6%, kappa= .414. CONCLUSIONS: In the evaluation of CVR, there is only a minimal correlation between the particular TCD tests (both BH/HV and BHI), and fMRI examination. However, there is a moderate correlation between TCD and fMRI in the case of congruity of both TCD tests.     

Identification of patients with ventricular tachycardia after myocardial infarction: signal-averaged electrocardiogram, Holter monitoring, and cardiac catheterization

Electrocardiographic signal averaging techniques have demonstrated a low-amplitude late potential and a long filtered QRS complex in patients with ventricular tachycardia (VT) after myocardial infarction. Complex ventricular ectopy and left ventricular aneurysms have also been associated with VT. The purposes of this study were (1) to determine whether the findings from the signal-averaged electrocardiogram (ECG) were independent of those from Holter monitoring and cardiac catheterization and (2) to determine the combination of findings from the signal-averaged ECG, cardiac catheterization, and Holter monitoring that best characterize patients with VT after myocardial infarction. We studied 174 patients after myocardial infarction, 98 of whom had recurrent sustained VT. By multivariate logistic regression only three parameters were found to be independently significant, listed in order of power: positive signal-averaged ECG (presence of a late potential or a long filtered QRS duration), peak premature ventricular contraction greater than 100/hr, and presence of a left ventricular aneurysm (p less than .001). The signal-averaged ECG provides independent information in identifying patients with VT after myocardial infarction.     

The selective gating of the N30 cortical component of the somatosensory evoked potentials of median nerve is different in the mesial and dorsolateral frontal cortex: evidence from intracerebral recordings.

OBJECTIVE: The somatosensory evoked potentials of the median nerve (SEP) were registered intracerebrally in 12 subjects to elucidate the origin of N30 component and its behavior in the motor 'gating' tasks. METHODS: The recordings were done from the electrodes which were inserted within the cortex of frontal lobe in the pre-surgical phase of epilepsy surgery. The registrations focused on the precentral N30 SEP component and its behaviour under the 'gating' paradigms. Two different 'gating' paradigms, motor and mental, were used and the SEP then were recorded in 3 conditions: (1) normal (N) paradigm, during which the subjects were instructed not to perform any movement by the stimulated hand, or to mentally simulate the movement; (2) active movement (AM) paradigm, during which the subjects were instructed to perform the active movement as the internal motor sequence test by the fingers of the hand of the stimulated limb; (3) mental movement simulation (MMS), during which the subjects were instructed to only mentally simulate the movements performed in the previous paradigm, and this 'virtual' movement also involved the hand of the stimulated limb. The recordings were done at least twice in each paradigm and averaged runs of 2000 artefact-free sweeps were used for the analysis. RESULTS: The results demonstrated that the precentral N30 component of SEP is generated only in the pre-motor area, either dorsolaterally or mesially, which consists of Brodmann's areas 6 and 8, and their borders. Only the N30 potentials recorded there in 7 subjects had a shape and character of 'near-field' potential. The behaviour of the N30 component when recorded in the AM and MMS paradigms was different depending on the fact of whether they were recorded dorsolaterally or mesially. When there was a clear 'near-field' N30 potential recorded mesially, there was a certain gating present during the AM paradigm, i.e. during the performance of movement. However, the gating caused by the mental movement simulation in the MMS paradigm was substantially more expressed, and the N30 wave practically disappeared in some cases. On the contrary, the gating of the N30 wave, recorded in the frontal dorsolateral premotor cortex (DLPC), was almost complete when the AM (active movement) paradigm was employed, and it was only partial when the MMS paradigm (mental movement simulation) was employed. CONCLUSIONS: The results of N30 registrations in our group of patients strongly support the theory of separate generator (or generators) of the N30 wave within the premotor cortex. They also brought forward evidence that the dorsolateral premotor cortex (Brodmann's areas 6 and 8) serves as the substrate of the 'motor execution' process, and the mesial frontal cortex (Brodmann's area 6) serves as the substrate of the 'motor planning' process. Further research should focus on the mutual registration of neurophysiological phenomena and imaging phenomena to obtain new data, which will be able to more precisely elucidate the workings of the premotor cortex during the whole process of motor performance.     

Peptides from the amino terminal mdm-2-binding domain of p53, designed from conformational analysis, are selectively cytotoxic to transformed cells

We have synthesized three peptides from the mdm-2 binding domain of human p53, residues 12-26 (PPLSQETFSDLWKLL), residues 12-20, and 17-26. To enable transport of the peptides across the cell membrane and at the same time to maximize the active mdm-2 binding alpha-helical conformation for these peptides, each was attached at its carboxyl terminus to the penetratin sequence, KKWKMRRNQFWVKVQRG, that contains many positively charged residues that stabilize an alpha-helix when present on its carboxyl terminal end. All three peptides were cytotoxic to human cancer cells in culture, whereas a control, unrelated peptide attached to the same penetratin sequence had no effect on these cell lines. The same three cytotoxic peptides had no effect on the growth of normal cells, including human cord blood-derived stem cells. These peptides were as effective in causing cell death in p53-null cancer cells as in those having mutant or normal p53. Peptide-induced cell death is not accompanied by expression of apoptosis-associated proteins such as Bax and waf(p21). Based on these findings, we conclude that the antiproliferative effects of these p53-derived peptides are not completely dependent on p53 activity and may prove useful as general anticancer agents.