Application of right atrial contiguous linear lesions: an in vivo efficacy validation of multipolar ablation catheters in an animal model

Catheter ablation of atrial flutter and catheter Maze procedures require the creation of linear lesions. The efficacy of different multipolar catheters to create linear contiguous transmural lesions was studied in a sheep model. In 19 sheep a multipolar ablation catheter was inserted into the right atrium. In nine sheep a steerable 7 Fr catheter (C1) with six 6-mm electrodes and in five sheep a steerable 7 Fr catheter (C2) with four 5-mm electrodes were placed. In five sheep a 3.7 Fr catheter (C3) with eight electrodes of 6-mm length was deployed (steerable sheath). A total of 72 linear lesions were created and evaluated. Catheter types C1, C2, and C3 produced continuous lesions with at least two adjacent electrodes in 45%, 79%, and 87% of the lesions. The mean lesion length achieved by C3 was longer compared to C1 and C2 (27 +/- 14 vs 10 +/- 5 and 11 +/- 6 mm; P < 0.05). The ability to produce contiguous lesions by all available electrodes was low: C1, 5%; C2, 5%; and C3, 6%. C3 was most effective in exerting transmural lesions (93% vs C1 75% and C2 57%; P < 0.0001). Microscopic endocardial fibrinous adhesions and macroscopic mild electrode carbonizations were caused by all catheter types. In conclusion, (1) all three catheter types do not create contiguous lesions along all electrodes. Gaps of viable tissue remain in most instances; (2) lesion depths and transmurality varies with different catheters; and (3) potentially hazardous thrombotic material was observed during radiofrequency ablation with all three catheters.     

Neural oscillations in antipsychotic-naïve patients with a first psychotic episode

Objectives: In chronic schizophrenic psychoses, oscillatory abnormalities predominantly occur in prefrontal cortical regions and are associated with reduced communication across cortical areas. Nevertheless, it remains unclear whether similar alterations can be observed in patients with a first episode of psychosis (FEP), a state characterised by pathological features occurring in both late prodromal patients and initial phases of frank schizophrenic psychoses. Methods: We assessed resting-state electroencephalographic data of 31 antipsychotic-naïve FEP patients and 29 healthy controls (HC). We investigated the three-dimensional (3D) current source density (CSD) distribution and lagged phase synchronisation (LPS) of oscillations across small-scale and large-scale brain networks. We additionally investigated LPS relationships with clinical symptoms using linear mixed-effects models. Results: Compared to HC, FEP patients demonstrated abnormal CSD distributions in frontal areas of the brain; while decreased oscillations were found in the low frequencies, an increase was reported in the high frequencies (P?<?0.01). Patients also exhibited deviant LPS in the high frequencies, whose dynamics changed over increasing 3D cortico-cortical distances and increasing psychotic symptoms. Conclusions: These results indicate that in addition to prefrontal cortical abnormalities, altered synchronised neural oscillations are also present, suggesting possible disruptions in cortico-cortical communications. These findings provide new insights into the pathophysiological mechanisms of emerging schizophrenic psychoses.     

Gastrointestinal Diagnosis of Classical Whipple Disease: Clinical,Endoscopic, and Histopathologic Features in 191 Patients

Classic Whipple disease (CWD) is a systemic infection caused by Tropheryma whipplei. Different diagnostic tools have been developed over the last decades: periodic acid-Schiff (PAS) staining, T whipplei-specific polymerase chain reaction (PCR), and T whipplei-specific immunohistochemistry (IHC). Despite all these advances, CWD is still difficult to diagnose because of a variety of clinical symptoms and possibly a long time span between first unspecific symptoms and the full-blown clinical picture of the disease.Herein, we report an observational cohort study summarizing epidemiologic data, clinical manifestations, and diagnostic parameters of 191 patients with CWD collected at our institution. Gastrointestinal manifestations are the most characteristic symptoms of CWD affecting 76% of the cohort. Although the small bowel was macroscopically conspicuous in only 27% of cases, 173 (91%) patients presented with characteristic histological changes in small bowel biopsies (in 2 patients, these changes were only seen within the ileum). However, 18 patients displayed normal small bowel histology without typical PAS staining. In 9 of these patients, alternative test were positive from their duodenal specimens (ie, T whipplei-specific PCR and/or IHC). Thus, in 182 patients (95%) a diagnostic hint toward CWD was obtained from small bowel biopsies. Only 9 patients (5%) were diagnosed solely based on positive T whipplei-specific PCR and/or IHC of extraintestinal fluids (eg, cerebrospinal fluid, synovial fluid) or extraintestinal tissue (eg, lymph node, synovial tissue), respectively.Thus, despite efforts to diagnose CWD from alternative specimens, gastroscopy with duodenal biopsy and subsequent histological and molecular–biological examination is the most reliable diagnostic tool for CWD.     

Formation of benzo[a]pyrene-DNA adducts in blood monocytes from lung cancer patients with a familial history of lung cancer

Summary The in vitro formation of benzo[a]pyrene-DNA adducts was determined in peripheral blood monocytes of 22 lung cancer patients with at least one first-degree relative with lung cancer and compared to results obtained in 30 healthy controls. In patients, the mean (SEM) adduct formation was 2.8 (0.3) fmol/g DNA as compared to 2.1 (0.1) fmol/g in controls (p<0.05), and it was independent of age and smoking habits. These findings support the hypothesis that carcinogen-DNA adduct formation may be one factor of a constitutionally enhanced lung cancer risk.This work was supported by a grant from the German Minister for Research and Technology, BMFT Definition: Pack-year, 1 packet of cigarettes/day x no. years they were smoked