Sequential EEG mapping may differentiate "epileptic" from "non-epileptic" rolandic spikes.

Sequential topographic mapping was performed to differentiate "epileptic" from "non-epileptic" rolandic spikes. Twenty-four children without any indication of organic brain lesion were divided into a group with epilepsy and a group without epilepsy. The group with epilepsy was subdivided into "classical BECT" (benign focal epilepsy of childhood with centro-temporal spikes) and "non-classical BECT." Sequential mapping of the rolandic spikes revealed two different topographic patterns: a pattern of stationary potential fields and a pattern of non-stationary potential fields. The topographic pattern of stationary potential fields was morphologically represented by a single spike-and-wave complex whereas that of non-stationary potential fields was morphologically represented by a "double" spike-and-wave complex. Among the non-stationary topographic patterns represented by a "double" spike, one specific sequence of changes of potential fields was found. This sequence started with a dipolar field, with the negative pole in the frontal region and the positive pole in the centro-temporal region, morphologically represented by the small first spike of the "double" spike-and-wave complex. This dipolar field, changes to a unipolar or dipolar field, with a negative potential field in the centro-temporal region and, sometimes, a simultaneous positive potential field in the frontal region, morphologically represented by the prominent rolandic spike. This characteristic pattern was found to be significantly related to classical BECT.     

Effects of water-borne cadmium on the skin of the common carp (Cyprinus carpio)

The skin of carp, Cyprinus carpio, was studied at the ultrastructural level after exposure of the fish to low and high concentrations of cadmium in the water (22 and 560 g/L, respectively) for different periods. The effects of the low concentration of cadmium were similar to those of the high concentration, although they appeared later. The basal lamina and the skin surface became highly undulating. Chloride cells appeared between the pavement cells. Necrotic pavement cells were seen from the first day on, while apoptotic pavement cells appeared after several days. Filament cells contained many electron-transparent and electron-dense secretory vesicles. Mitotic cells were commonly seen, mainly in cells adjacent to club cells or close to the epidermal surface. Mucous cells differentiated close to the skin surface. They became elongated and synthesized highly electron-dense mucosomes. The epidermis became infiltrated by many leucocytes. As the experiment progressed, many leucocytes degenerated, and their remnants were found within macrophages and club cells. Fibroblasts displayed intense synthesis and, in fish from the low cadmium concentration, deposited a dense network of collagen fibers in the dermis. Melanosomes were located in the extensions of melanocytes. In these cells aggregation of melanosomes and apoptotic processes were common. Several of these changes were observed earlier under the impact of stressors other than cadmium. Some changes, such as the appearance of tumorlike bodies at the skin surface, the appearance of Merkel cells throughout the epidermis, and the coupling of leucocytes, may be specific for cadmium.     

lschaemic heart disease: Non-invasive prediction of reperfusion and coronary artery patency by continuous ST segment monitoring in the GUSTO-I trial

In the GUSTO-I ECG ischaemia monitoring substudy, 1067 patientsunderwent continuous ST segment monitoring, using vector-derived12-lead (406 patients), 12-lead (373 patients) and 3-lead Holter(288 patients) ECG recording systems. Simultaneous angiogramsat 90 or 180 min following thrombolytic therapy were performedas a part of the prospective study in 302 patients. Infarct vessel patency was established as TIMI perfusion grades2 or 3 and occlusion as TIMI perfusion grades 0 or 1. Coronaryartery patency was predicted from ST trends up to the time ofangiography. Predictive values at 90 and 180 min after the startof thrombolysis were 70% and 82% for patency and 58% and 64%for occlusion, respectively. In retrospect, accuracy appearedgreatest (79–100%) in patients with extensive ST segmentelevation (400 µV), if both speed of ST recovery and extentof ST segment: elevation were taken into account. Although thethree recording systems differed considerably in signal processing,no significant difference in accuracy was demonstrated amongthese systems. We conclude that continuous ECG monitoring may help select highrisk patients without apparent reperfusion who may benefit fromadditional reperfusion therapy. As ST recovery may occur earlyafter the start of thrombolytics and accuracy of the test isrelated to peak ST levels, the use of on-line ECG monitoringdevices on emergency wards and cardiac care units is recommended.(Eur Heart J 1996; 17: 689–698)     

An Optimal Measurement of Fixation Disparity Using Ogle’s Apparatus

ABSTRACT

Purpose: Fixation disparity (FD) is a small misalignment of the eyes within the normal alignment when viewing under binocular condition. Ogle’s apparatus measures FD. Standards of procedures vary, which may lead to different outcomes.

Methods: Students with normal ocular alignment, stereopsis ≤60 seconds of arc and visual acuity <0.1 logMAR, were included in this prospective comparative study. Four procedures (P1-P4) of measuring FD with Ogle’s apparatus were performed with divergent placement of the line (P1 and P3), or the line moving from subjective zero (P1 and P2: prisms of ascending strength; P3 and P4: prisms alternating base in base out; combined and P4). Differences in the FD curve were determined by looking at point zero, motor fusion amplitude, and the degree of FD.

Results: Twenty-six participants were examined by these 4 procedures. Point zero showed a significant difference between P1-P2 (P=0.006) and P3-P4 (P=0.001). P1 and P3 indicated the highest point zero: median of -1 and -1.5 minutes of arc exodisparity. Motor fusion amplitude showed a significant difference between P1-P2 (P=0.037), P1-P3 (P=0.004), and P2-P4 (P=0.002). P1 revealed the highest motor fusion amplitude (median of 34Δ) and P4 the lowest amplitude (median of 28Δ). No significant differences were found in esodisparity. In exodisparity there was a significant difference comparing P1-P2 (P=0.000), P3-P4 (P=0.000), and P1-P3 (P=0.021). P1 gave the highest exodisparity (median 22 minutes of arc) and P4 the lowest (median 10 minutes of arc).

Conclusion: Clinically relevant differences were found in exodisparity, mainly caused by difference in line shifting. Exodisparity was significantly lower, moving the line from subjective zero. The most accurate procedure is using prisms of ascending strength combined with divergent placement of the line (P1). These findings standardize a reliable procedure of measuring the FD curve for clinical use. Patients will not be misdiagnosed with reduced FD.     

The influence of clan structure on the genetic variation in a single Ghanaian village

Socioeconomic and cultural factors are thought to have an important role in influencing human population genetic structure. To explain such population structure differences, most studies analyse genetic differences among widely dispersed human populations. In contrast, we have studied the genetic structure of an ethnic group occupying a single village in north-eastern Ghana. We found a markedly skewed male population substructure because of an almost complete lack of male gene flow among Bimoba clans in this village. We also observed a deep male substructure within one of the clans in this village. Among all males, we observed only three Y-single-nucleotide polymorphism (SNP) haplogroups: E1b1a*-M2, E1b1a7a*-U174 and E1b1a8a*-U209, P277, P278. In contrast to the marked Y-chromosomal substructure, mitochondrial DNA HVS-1 sequence variation and autosomal short-tandem repeats variation patterns indicate high genetic diversities and a virtually random female-mediated gene flow among clans. On the extreme micro-geographical scale of this single Bimoba village, correspondence between the Y-chromosome lineages and clan membership could be due to the combined effects of the strict patrilocal and patrilineal structure. If translated to larger geographic scales, our results would imply that the extent of variation in uniparentally inherited genetic markers, which are typically associated with historical migration on a continental scale, could equally likely be the result of many small and different cumulative effects of social factors such as clan membership that act at a local scale. Such local scale effects should therefore be considered in genetic studies, especially those that use uniparental markers, before making inferences about human history at large.