The impact of temporal compression and space selection on SVM analysis of single-subject and multi-subject fMRI data

In the present study, we compared the effects of temporal compression (averaging across multiple scans) and space selection (i.e. selection of "regions of interest" from the whole brain) on single-subject and multi-subject classification of fMRI data using the support vector machine (SVM). Our aim was to investigate various data transformations that could be applied before training the SVM to retain task discriminatory variance while suppressing irrelevant components of variance. The data were acquired during a blocked experiment design: viewing unpleasant (Class 1), neutral (Class 2) and pleasant pictures (Class 3). In the multi-subject level analysis, we used a "leave-one-subject-out" approach, i.e. in each iteration, we trained the SVM using data from all but one subject and tested its performance in predicting the class label of the this last subject's data. In the single-subject level analysis, we used a "leave-one-block-out" approach, i.e. for each subject, we selected randomly one block per condition to be the test block and trained the SVM using data from the remaining blocks. Our results showed that in a single-subject level both temporal compression and space selection improved the SVM accuracy. However, in a multi-subject level, the temporal compression improved the performance of the SVM, but the space selection had no effect on the classification accuracy.     

The hepoxilin analog, PBT-3, inhibits growth of K-562 CML solid tumours in vivo in nude mice

PBT-3 is one of a family of stable chemical analogs of the hepoxilins, products derived from arachidonic acid. We previously showed that PBT-3 caused apoptosis in the chronic myelogenous leukemia (CML) cell line K-562 in vitro (Anti-cancer Res 23: 3617-3622, 2003). It was as effective as Gleevec, a novel agent that blocks tyrosine kinase activity during treatment of CML. We describe, herein, the growth inhibiting effects of PBT-3 in nude mice into which K-562 cells were transplanted subcutaneously. Groups of mice were treated with vehicle as control, or PBT-3, or Gleevec. PBT-3 was effective during the 8-day treatment protocol in inhibiting the growth of the tumours in vivo as was Gleevec. Analysis of the tumours demonstrated the presence of apoptosis (DNA laddering and TUNEL assay) in both the PBT-3- and Gleevec-treated groups. These results demonstrate that PBT-3 is effective in vivo in controlling tumour growth and provides a novel platform for the therapeutic control of cancer.     

Severe fetal cytomegalic inclusion disease after documented maternal reactivation of cytomegalovirus infection during pregnancy

Recurrent cytomegalovirus infection during pregnancy is considered less dangerous for the fetus than primary infection. We present a case of severe fetal cytomegalic inclusion disease after maternal reactivation of cytomegalovirus during the first trimester of pregnancy. The possibility of such fetal injury is an argument for prenatal diagnosis in seropositive pregnant women when ultrasonographic findings suggest cytomegalovirus infection.     

Cervical ganglioneuroma. Review, apropos of a case

We describe a case of cervical ganglioneuroma, an uncommon benign tumor which develops slowly, predominantly in females and infants. Ganglioneuromas have a neuroectodermic origin and are localized along the sympathetic trunk. Most are unmasked fortuitously by palpation or by high serum catecholamine levels proportional to tumor size. After radiographic exploration and surgical excision, a pathologic study of the surgical specimen is required to identify this very differentiated tumor stemming from the neural crest.     

Spike conduction properties of T-shaped C neurons in the rabbit nodose ganglion

Noradrenaline (NA) and angiotensin II (A II) were infused intravenously in conscious dogs without (series I) and with (series II) additional infusions of sodium nitroprusside at doses re-establishing normal levels of mean arterial pressure (MAP). In series I, NA infusion (1.6 g/min per kg for 30 min) initially elevated MAP by some 25 mm Hg and lowered heart rate by some 30 beats/min. Plasma concentrations of arginine vasopressin (AVP) remained constant, while those of A II and atrial natriuretic factor were slightly, but significantly, increased. Infusion of A II (10 or 20 ng/min per kg for 30 min) induced similar rises in MAP and slight reductions of heart rate and increased plasma AVP by 70% and atrial natriuretic factor by 60%. In series II, sodium nitroprusside (1–4 g/min per kg) was added for 30 min to infusions of NE (1.6 g/min per kg) and A II (20 ng/min per kg) in order to maintain MAP at its control level. This resulted in an 11-fold increase in plasma AVP during NA infusion and a 19-fold increase during A II infusion. Infusing sodium nitroprusside (4 g/min per kg) alone lowered MAP to clearly hypotensive levels, but the resulting rises in plasma AVP were less than, rather than equal to, those seen at normotensive MAP levels during the combined infusions of sodium nitroprusside with A II or NA, respectively. It is concluded that both NA and A II exert strong stimulatory actions on AVP release which are, however, counteracted by inhibitory influences arising from the hypertensive effects of NA and A II.     

A rare case of brainstem encephalitis by Listeria monocytogenes with isolated mesencephalic localization. Case report and review

We describe a case of brainstem infection by Listeria monocytogenes with right oculomotor palsy and lip drop, facial hypoesthesia, left arm paresthesia, positive blood culture, and sterile liquor in a 63-year-old man. Magnetic resonance imaging revealed an isolated mesencephalic lesion. Localization of this kind accounted for 3% of 111 cases reviewed.