Influence of the distribution of collateral circulation on left ventricular segmental kinetics

Correlations between left ventricular segmental kinetics and collateral circulation patterns were studied in 292 patients with coronary disease (182 women, 274 men: mean age 54 years). Left ventricular segmental kinetics were analyzed qualitatively by angiography (10 segments were individualized on RAO and LAO projections) and rated as normal, hypokinetic, akinetic or aneurysmal. The type of collateral circulation observed (contralateral, homocoronary and homolateral) and the number of collateral vessels were recorded. Collateral circulation was present in 49 p. 100 of the patients and in 29 p. 100 of the 587 pathological arteries (i.e. more than 50 p. 100 stenosis) identified. 89 p. 100 of the occluded arteries were revascularized by collateral circulation, the latter being effected by 213 collateral vessels (mean: 1.41 +/- 0.36 vessel per occluded artery). Collateral circulation through 1, 2 or 3 collateral vessels was noted in 62 p. 100, 35 p. 100 and 3 p. 100 respectively of the cases. Collateral circulation was contralateral in 51 p. 100, homocoronary in 33 p. 100 and homolateral in 16 p. 100 of the cases. Normal or hypokinetic segments in the territory of an occluded artery were more frequent in the presence (43 p. 100) than in the absence (31 p. 100) of collateral circulation, but the difference was not significant. They were also more frequent in three-vessel patients (59 p. 100) than in one-vessel (21 p. 100; p less than 0.01) or two-vessel (37 p. 100; p less than 0.05) patients in the presence of collateral circulation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Primary and transitional progressive MS: a clinical and MRI cross-sectional study

BACKGROUND: Ten percent of patients with MS have a progressive course from onset with no history of relapses or remissions. A smaller subgroup follow a similar progressive course but have a single relapse at some point (transitional progressive [TP] MS). To date these patients have been excluded from receiving licensed treatments for MS and from most therapeutic trials. OBJECTIVE: To document the clinical and MRI characteristics of a large cohort of progressive patients, including 158 with primary progressive (PP) MS and 33 with TPMS. Data from a small reference group of 20 patients with secondary progressive (SP) MS are also presented for reference. METHODS: Patients were recruited from six European centers. All underwent a clinical assessment including scoring on the Expanded Disability Status Scale (EDSS) and MRI of the brain and spinal cord. RESULTS: The men-to-women ratio was 81:77 (51% men) in the PP group, 14:19 (42% men) in the TP group, and 5:15 (25% men) in the SP group. The mean age at disease onset was significantly higher in the PP group than it was in the other two groups (PP 40.2 years, TP 34.9 years, SP 28.7 years). On MRI the PP group had lower mean brain T2 and T1 hypointensity lesion loads than the SP group (T2 12.02 versus 27.74 cm3, p = 0.001; T1 4.34 versus 7.04 cm3, p = 0.015). The SP and TP cohorts had significantly more T2-weighted lesions in the spinal cord than the PP patients, and the SP cohort had the greatest degree of atrophy. There was a correlation in the PP and TP patients between EDSS score and brain and spinal cord atrophy (r = 0.3, 0.2, p < or = 0.006) but not with brain lesion load. The PP and TP patients who presented with spinal cord pathology had significantly lower brain T2 and T1 lesion loads than those with non-spinal cord presentations (p = 0.002). CONCLUSIONS: The monitoring of disease progression in PPMS is difficult, although measures of atrophy correlate with the EDSS and appear most promising. This study increases our understanding of this unique patient group, which will be further expanded with the acquisition of serial data.     

Ginkgo biloba extract EGb761 reduces the development of amphetamine-induced behavioral sensitization: effects on hippocampal type II corticosteroid receptors

Pretreatment of rats with the extract of Ginkgo biloba termed EGb761 reduced the behavioral sensitization induced by successive -amphetamine administrations (0.5 mg/kg) as estimated by increasing values of locomotor activity. EGb761 pretreatment also prevented the reduced density of [³H]dexamethasone binding sites in the dentate gyrus and the CA1 hippocampal regions of -amphetamine treated animals. These observations suggest that EGb761, by reducing glucocorticoid levels, could modulate the activity of the neuronal systems involved in the expression of the behavioral sensitization.     

Imaging microdomain Ca2+ in muscle cells

Ca2+ ions passing through a single or a cluster of Ca2+-permeable channels create microscopic, short-lived Ca2+ gradients that constitute the building blocks of cellular Ca2+ signaling. Over the last decade, imaging microdomain Ca2+ in muscle cells has unveiled the exquisite spatial and temporal architecture of intracellular Ca2+ dynamics and has reshaped our understanding of Ca2+ signaling mechanisms. Major advances include the visualization of "Ca2+ sparks" as the elementary events of Ca2+ release from the sarcoplasmic reticulum (SR), "Ca2+ sparklets" produced by openings of single Ca2+-permeable channels, miniature Ca2+ transients in single mitochondria ("marks"), and SR luminal Ca2+ depletion transients ("scraps"). As a model system, a cardiac myocyte contains a 3-dimensional grid of 104 spark ignition sites, stochastic activation of which summates into global Ca2+ transients. Tracking intermolecular coupling between single L-type Ca2+ channels and Ca2+ sparks has provided direct evidence validating the local control theory of Ca2+-induced Ca2+ release in the heart. In vascular smooth muscle myocytes, Ca2+ can paradoxically signal both vessel constriction (by global Ca2+ transients) and relaxation (by subsurface Ca2+ sparks). These findings shed new light on the origin of Ca2+ signaling efficiency, specificity, and versatility. In addition, microdomain Ca2+ imaging offers a novel modality that complements electrophysiological approaches in characterizing Ca2+ channels in intact cells.     

Detection of coronary disease before valve surgery. Contribution of myocardial scintigraphy with dipyridamole

The detection of coronary disease before valve surgery remains difficult in the absence of coronary arteriography. The contribution of myocardial scintigraphy with dipyridamole (MS-DP) was studied in 34 consecutive patients with valve disease (11 mitral and 23 aortic) with a mean age of 63 +/- 11 years having undergone coronary arteriography before valve surgery. Coronary arteriography was performed because of angina (21 cases) or age (women greater than 50, men greater than 40). Positive criteria of coronary disease were the presence of at least one frank and clearly visible fault of myocardial perfusion (MS-DP positive) and at least one stenosis of greater than 70 per cent by coronary arteriography. Coronary disease existed in 13 patients (38 per cent). Ten patients (29 per cent) had a positive MS-DP. The sensitivity and specificity of MS-DP in detecting coronary disease were 69 per cent and 95 per cent respectively. Its positive predictive value was 90 per cent. MS-DP was negative in all asymptomatic patients (19 per cent of them having coronary disease) and in 11 symptomatic patients (18 per cent of them having coronary disease). The low positive predictive value of angina (52 per cent) increased to 90 per cent when combined with a positive MS-DP. Because of relatively low sensitivity, basing indications for coronary arteriography before valve surgery on the results of MS-DP cannot be advised.     

Colonic motility diagnosis based on colonic pressure

Manometry of the alimentary tract is a valuable and widely used means to evaluate and diagnose the function of the alimentary tract. However, the measurement can be inconvenient due to the invasive method used, and the many factors affecting results. Research on colonic pressure data is even more insufficient. This paper deals with colonic pressure data via an improved method ensuring that pressure data of the whole colon is available. The data is analysed based on the learning vector quantization (LVQ) method. Testing results show that this method distinguishes the normal data and the abnormal data, consistently with the original diagnoses. This method can serve as an assistant diagnosis of colonic motility and contributes to further research on colonic motility based on pressure data.