Increased frequency of cardioembolism and patent foramen ovale in patients with stroke and a positive travel history suggesting economy class stroke syndrome

OBJECTIVE

To investigate the frequency of acute stroke in patients with a recent travel history and to analyse risk factors, stroke patterns and presence of a patent foramen ovale (PFO) in this patient group.

DESIGN

One-year prospective observational study.

SETTING

Single-centre study.

METHODS

Enrolling all patients presenting with a first cerebral ischaemia and complementing the usual history with a standardised travel history.

RESULTS

Of 338 patients with acute stroke, 42 had a positive travel history (PTH) (12.4%). Patients with a PTH were significantly younger (56.6 (SD 13) years) than patients (66.9 (13.2) years, p = 0.0001) with a negative travel history (NTH). Frequency of PFO in the PTH group (13; 44.8%) was significantly higher than in the NTH group (7; 10.8%) (p = 0.0001), even after patients were dichotomised into two age groups (younger and older than median of all

PATIENTS

31% v 6.1%, p = 0.007 and 13.8% v 4.6%, p = 0.022, respectively). PTH patients had fewer stroke risk factors (2.2 (1.4) v 3.3 (1.6), p = 0.0001) and a different risk profile with a lower frequency of diabetes (11.9% v 31.4%, p = 0.009), hypertension (52.4% v 78.7%, p = 0.0001), atrial fibrillation (7.1% v 22%, p = 0.025) and others (16.7% v 38.9%, p = 0.005). In contrast, PTH patients had significantly more cardioembolic (35.7% v 19.3%, p = 0.023) and cryptogenic strokes (50% v 19.9%, p = 0.0001) and more often ischaemia in the territory of the posterior cerebral artery (29.6% v 6.3%, p = 0.0001).

CONCLUSIONS

The finding that more PTH patients had a PFO and a cardioembolic stroke pattern but that fewer had other typical stroke risk factors led to the hypothesis that PFO is a risk factor for economy class stroke syndrome.

Highly functionalized five-membered carbocycles from (3-dialkylamino-1-ethoxyalkenylidene)pentacarbonylchromium complexes and alkynes: the effects of substituents, solvents, ligand additives, and reagent concentrations on the product distribution

The cocyclization reaction of pentacarbonyl(beta-amino-1-ethoxyalkenylidene)chromium complexes 1 with alkynes has been studied with respect to the effects of substituents, solvents, ligand additives, and reagent concentrations upon the product distribution. This reaction proceeds either as a formal [2 + 2 + 1] cycloaddition to give 5-(1'-dialkylaminoalkylidene)-4-ethoxycyclopent-2-enones 8 or a formal [3 + 2] cycloaddition to give 5-dialkylamino-3-ethoxy-1,3-cyclopentadienes 9. A working hypothesis for the mechanism of this reaction is proposed on the basis of that previously determined for the Dötz reaction. The effects of the aforementioned parameters upon the product distribution of this current reaction are explained in terms of this model. A pronounced ligand-induced allochemical effect has been observed. Conditions for the selective preparation of both classes of cycloadducts 8 and 9 have been determined.

Fischer Carbene Complexes as Chemical Multitalents: The Incredible Range of Products from Carbenepentacarbonylmetal alpha,beta-Unsaturated Complexes

The metal carbene complexes, discovered by E. O. Fischer at the start of the 1960s and carrying his name, have since proved themselves to be irreplaceable building blocks for organic synthesis. In particular, since the discovery of the Dötz reaction, a formal cycloaddition of Fischer alpha,beta-unsaturated carbene complexes to alkynes with CO insertion, this area of chemistry has become increasingly interesting to organic chemists. In spite of the considerable diversity of reactions performed with these complexes, proper selection of substrates and careful adjustment of the reaction conditions have allowed, in most cases the perfectly selective preparation of individual compounds of this enormous range of products. The spectrum of new successes begins with the conventional Diels-Alder reaction of alkynylcarbene complexes and the formal regioselective [3+2] cycloaddition of alkenylcarbene complexes to alkynes. It extends much further, however, from cascade reactions with the formation of oligofunctional and oligocyclic products of impressive molecular complexity to complex, formal [3+6] cocyclizations in which six bonds are formed in a single operational step. Beyond doubt, the methodological arsenal of preparative organic chemistry cannot be imagined any more without the valuable transformations of the Fischer carbene complexes; it only remains to be seen whether one or other of the numerous new types of cocyclization products of these complexes can establish itself as a lead structure in the search for biologically active compounds.

Normative values of vibratory perception in 530 children, juveniles and adults aged 3-79 years

Impaired vibratory perception is an early and frequent finding in various neuropathies. Quantitative vibratory threshold assessment refines the diagnosis of neuropathies but is based on psychophysical techniques requiring patient cooperation. Large, age and sex matched normative data bases are needed to better identify abnormal vibratory perception. In this study vibratory perception was tested at the second metacarpal bone and above the first metatarsal bone of 530 children, juveniles and adults aged 3.3-79.2 years. Thresholds assessed with a 128 Hz graded Rydel-Seiffer tuning fork, TF, were compared to three Vibrameter values, the vibration perception thresholds, VPT, determined with increasing vibration stimuli, the vibration disappearance threshold, VDT, determined with decreasing supraliminal stimuli, and the vibration threshold VT which equals the mean of VPT and VDT. The influence of gender, age, body height, weight and skin temperature at the tested site on thresholds was studied. Retest reliability was tested in 73 children aged 3.3-6.9 years and in 20 volunteers aged 5.2-66.1 years who were also tested for the influence of pretest skin warming on thresholds and for differences between results of the left and right body side. TF, VPT, VDT, VT were closely correlated with each other (Spearman: -0.67<Rs<-0.47; P<0.01). The skin temperature, body side, weight and height did not influence thresholds. In adults, thresholds increased with age and were higher in men above the age of 50 than in women of the same age. Thresholds at the feet were higher than at the hands (Wilcoxon: P<0.001). Retest reliability was high and did not depend on the retest interval. The study provides important normative data for the widespread use of quantitative vibration testing.

Detection of colon cancer by monitoring the intracellular fluorescein fluorescence polarization changes in lymphocytes

Structuredness of the cytoplasmic matrix (SCM)-responding lymphocytes from healthy donors can be differentiated from SCM-responding lymphocytes of patients with malignant disease on the basis of the change in the intracellular fluorescein fluorescence polarization (IFFP) induced by their exposure to various antigens. We have found that the overall sensitivity, specificity and positive and negative predictive values of the test were 92.0, 92.6, 96.3, and 84.7%, respectively. We demonstrated the capability of the test to distinguish between healthy people and colorectal cancer patients per stage of the disease. We also found a significant difference in IFFP values between Dukes' C patients and patients with metastatic disease, rendering the test potentially helpful in follow-up.