Sphincter of Oddi dysfunction--prolonged medical therapy or early endoscopic sphincter ablation

INTRODUCTION: Sphincter of Oddi dysfunction is a real challenge from both diagnostic and therapeutic point of view. PATIENTS AND METHODS: In the last two years the authors have performed ERCP and EST in 29 patients with positive evocative test results, who had important enzyme elevations and/or did not respond to prolonged medical treatment. RESULTS: Endoscopic findings were positive in 25/29 patients (86.2%): 8 adenoma of p. Vateri, 17 papillitis were identified, and in 4 cases the papilla was intact. Histopathology obtained in 12 patients supported the diagnosis. In 6 patients, who underwent a postpapillotomy evocative test, after an average of 10 months follow up the results have been converted from positive to negative response in all but two cases. The two patients continued to have abdominal symptoms with persistent positive provocation tests because of restenosis, were treated with repapillotomy. CONCLUSIONS: The Debray and Nardi tests are useful screening tests for hypertonic biliary or pancreatic dyskinesia. Structural endoscopic and histological findings are frequent already in the functional cases. Early sphincter ablation should be considered in failure of medical therapy for preventing the transformation of this functional disorder into an organic, potentially precancerous state.     

Comparing brain activation associated with isolated upper and lower limb movement across corresponding joints

It was shown recently that functional activation across brain motor areas during locomotion and foot movements are similar but differ substantially from activation related to upper extremity movement (Miyai [2001]: Neuroimage 14:1186-1192). The activation pattern may be a function of the behavioral context of the movement rather than of its mechanical properties. We compare motor system activation patterns associated with isolated single-joint movement of corresponding joints in arm and leg carried out in equal frequency and range. Eleven healthy volunteers underwent BOLD-weighted fMRI while performing repetitive elbow or knee extension/flexion. To relate elbow and knee activation to the well-described patterns of finger movement, serial finger-to-thumb opposition was assessed in addition. After identifying task-related voxels using statistical parametric mapping, activation was measured in five regions of interest (ROI; primary motor [M1] and somatosensory cortex [S1], premotor cortex, supplementary motor area [SMA] divided into preSMA and SMA-proper, and cerebellum). Differences in the degree of activation across ROIs were found between elbow and knee movement. SMA-proper activation was prominent for knee, but almost absent for elbow movement (P < 0.05); finger movement produced small but constant SMA-proper activation. Ipsilateral M1 activation was detected during knee and finger movement, but was absent for the elbow task (P < 0.05). Knee movement showed less lateralization in M1 and S1 than other tasks (P < 0.05). The data demonstrate that central motor structures contribute differently to isolated elbow and knee movement. Activation during knee movement shows similarities to gait-related activation patterns.     

Modelling large scale neuronal networks using 'average neurones'

Large scale neuronal network models have become important tools in studying the information transmission within the CNS. In most cases, these models use simplifying assumptions because of unavailable data (e.g. unknown exact network connectivity), and for technical reasons (to preserve numerical stability of the model). Here, we present a novel approach, based on a probabilistic connectivity principle, to this modelling problem for which no knowledge of the exact network connectivity is required. This principle makes it sufficient to compute only the typical neuronal behaviour, represented by 'average neurones', in the network. As a consequence, detailed neurone models can be employed without seriously compromising computational efficiency. Our model thus provides a viable alternative to deterministic models.     

Modelling normal tissue isoeffect distribution in conformal radiotherapy of glioblastoma provides an alternative dose escalation pattern through hypofractionation without reducing the total dose

The purpose of this study was to prove that by using conformal external beam radiotherapy (RT) normal brain structures can be protected even when applying an alternative approach of biological dose escalation: hypofractionation (HOF) without total dose reduction (TDR). Traditional 2-dimensional (2D) and conformal 3-dimensional (3D) treatment plans were prepared for 10 gliomas representing the subanatomical sites of the supratentorial brain. Isoeffect distributions were generated by the biologically effective dose (BED) formula to analyse the effect of conventionally fractionated (CF) and HOF schedules on both the spatial biological dose distribution and biological dose-volume histograms. A comparison was made between 2D-CF (2.0 Gy/day) and 3D-HOF (2.5 Gy/day) regimens, applying the same 60 Gy total doses. Integral biologically effective dose (IBED) and volumes received biologically equivalent to a dose of 54 Gy or more (V-BED54) were calculated for the lower and upper brain stem as organs of risk. The IBED values were lower with the 3D-HOF than with the 2D-CF schedule in each tumour location, means 22.7+/-17.1 and 40.4+/-16.9 in Gy, respectively (p < 0.0001). The V-BED54 values were also smaller or equal in 90% of the cases favouring the 3D-HOF scheme. The means were 2.7+/-4.8 ccm for 3D-HOF and 10.7+/-12.7 ccm for 2D-CF (p = 0.0006). Our results suggest that with conformal RT, fraction size can gradually be increased. HOF radiotherapy regimens without TDR shorten the treatment time and seem to be an alternative way of dose escalation in the treatment of glioblastoma.     

Direct catecholaminergic-cholinergic interactions in the basal forebrain. III. Adrenergic innervation of choline acetyltransferase-containing neurons in the rat

The central adrenergic neurons have been suggested to play a role in the regulation of arousal and in the neuronal control of the cardiovascular system. To provide morphological evidence that these functions could be mediated via the basal forebrain, we performed correlated light and electron microscopic double-immunolabeling experiments using antibodies against phenylethanolamine N-methyltransferase (PNMT) and choline acetyltransferase, the synthesizing enzymes for adrenaline and acetylcholine, respectively. Most adrenergic/cholinergic appositions were located in the horizontal limb of diagonal band of Broca, within the substantia innominata, and in a narrow band bordering the substantia innominata and the globus pallidus. Quantitative analysis indicated that cholinergic neurons of the substantia innominata receive significantly higher numbers of adrenergic appositions than cholinergic cells in the rest of the basal forebrain. In the majority of cases, the ultrastructural analysis revealed axodendritic asymmetric synapses. By comparing the number and distribution of dopamine beta-hydroxylase (DBH)/cholinergic appositions, described earlier, with those of PNMT/cholinergic interactions in the basal forebrain, it can be concluded that a significant proportion of putative DBH/cholinergic contacts may represent adrenergic input. Our results support the hypothesis that the adrenergic/cholinergic link in the basal forebrain may represent a critical component of a central network coordinating autonomic regulation with cortical activation.     

Reduced thrombomodulin in human peripheral nerve microvasculature

Thrombomodulin (TM), a vascular endothelial receptor, terminates the actions of thrombin and accelerates activated protein C formation. TM is ubiquitous throughout the systemic microcirculation but is reduced in brain regions predisposed to lacunar infarction. We investigated whether TM is present within human nerve and differentially expressed according to vessel caliber and proximity to the blood-nerve barrier. Vascular endothelial TM was detected on sural nerve biopsies with immunohistochemistry. The proportion of TM-positive microvessels was expressed relative to total von Willebrand factor (vWF)-positive vessels. Although vWF was detectable in all microvessels, TM expression was absent from the perineurial vessels. TM was detected in 47% (15-80%, 95% confidence level) of larger epineurial arterioles, in 43% (30-61%) of smaller epineurial vessels, and in 30% (19-47%) of endoneurial vessels. These findings demonstrate that TM is present in human nerve microvasculature but is regionally deficient in proximity to the blood-nerve barrier, which may predispose nerve to microvascular ischemia in inflammatory/prothrombotic conditions.     

Findings from the Global Youth Tobacco Survey (GYTS) in Czech Republic, Hungary, Poland and Slovakia – smoking initiation, prevalence of tobacco use and cessation

Objectives  

To show selected findings from the Global Youth Tobacco Survey (GYTS) conducted in Czech Republic, Hungary, Poland and Slovakia.     

Improving diagnostic accuracy of prostate carcinoma by systematic random map-biopsy

Systematic random rectal ultrasound directed map-biopsy of the prostate was performed in 77 RDE (rectal digital examination) positive and 25 RDE negative cases, if applicable. Hypoechoic areas were found in 30% of RDE positive and in 16% of RDE negative cases. The score for carcinoma in the hypoechoic areas was 6.5% in RDE positive and 0% in RDE negative cases, whereas systematic map biopsy detected 62% carcinomas in RDE positive, and 16% carcinomas in RDE negative patients. The probability of positive diagnosis of prostate carcinoma increased in parallel with the number of biopsy samples/case. The importance of systematic map biopsy is emphasized.