Epidemiology of visceral leishmaniasis in Atbara River area,eastern Sudan: the outbreak of Barbar El Fugara village (1996-1997)

An outbreak of visceral leishmaniasis (VL) started in 1995 in the Atbara River area in eastern Sudan. This article reports on this outbreak and on the clinical and immunological studies that were carried out in a village, with the highest incidence of VL cases, from 1996 to 1997. A significant increase in VL incidence was recorded in a dozen villages in this area; one village, Barbar El Fugara accounted for half of the total number of cases recorded at the regional hospital. A total of 152 VL and 61 post kala-azar dermal lesion (PKDL) cases were diagnosed and treated in Barbar. Household (n = 671) and school (n = 276) surveys were performed using the leishmanin skin test (LST) and the direct agglutination test (DAT). LST positivity was 23.1 and 15.7%, whereas DAT positivity was 8.9 and 26.4% in both surveys, respectively. No gender differences were observed in either test. Unlike DAT, LST positivity was predominant in the higher age groups that also exhibited lower prevalence of VL. Few individuals were positive by both tests (1.3%, 5.2%) while the majority (68.8%, 64.8%) had no evidence of acquired immune response, suggesting either a role of innate immunity in preventing parasite establishment or, unexpectedly, lack of exposure to Leishmania. Subclinical parasitism was also demonstrated, as evidence of both acquired humoral and cellular immune responses was observed in individuals with no past history of the disease. The wide spectrum of L. donovani/human interactions may be explained by differential exposure to environmental risk factors, parasite strain polymorphisms or host genetic makeup.     

Within-night variation in respiratory effort preceding apnea termination and EEG delta power in sleep apnea

We studied the within-night variability of themaximum esophageal pressure deflection before apnea termination(DP_max) in nine patients withsevere obstructive sleep apnea as an index of the arousal threshold andthe mean electroencephalogram (EEG) delta power for each 30 s as anindex of the timing of sleep cycles. Periodicity in the time variationof delta power and DP_max was analyzed by determining their power spectral density and their relationship determined by cross correlation.DP_max and delta power variedcyclically and in phase with a major periodicity (major peak in powerspectral density) of 117.6 ± 8.8 (SE) min. The correlation betweenthe values of DP_max and deltapower was significant (P < 0.001) ineach subject (mean r = 0.47 ± 0.03), and the coherence betweenDP_max and delta power at theirdominant frequency was high. Within cycles of non-rapid-eye-movementsleep, DP_max and delta powerincreased, reaching peak values on average at or after midcycle. Thesefindings suggest that the arousal threshold to airway occlusion inpatients with obstructive sleep apnea varies cyclically during thenight synchronous to the underlying cycles of sleep.

     

Regulation of adherens junction protein p120(ctn) by 10 nM CCK precedes actin breakdown in rat pancreatic acini

The initial pathophysiological events that characterize CCK-hyperstimulation pancreatitis include the breakdown of the actin filament system and disruption of cadherin-catenin protein complexes. Cadherins and catenins are part of adherens junctions, which may act as anchor for the cellular actin filament system. We examined the composition and regulation of adherens junctions during CCK-induced acinar cell damage. Freshly isolated CCK-stimulated rat pancreatic acini were examined for actin filaments and functional adherens junctions by immunocytology and laser confocal scanning microscopy or by coprecipitation and immunoblotting for E-cadherin, beta- and alpha-catenin, p120(ctn), and phosphotyrosine. In addition to E-cadherin and beta-catenin, acinar cells express the cadherin-regulatory protein p120(ctn) and the attachment protein alpha-catenin. Both colocalize and coimmunoprecipitate with E-cadherin in one complex, and all colocalize with the terminal actin web. Supramaximal secretory CCK concentrations (10 nM) initiated tyrosine phosphorylation of p120(ctn) but not of beta-catenin within 2 min, preceding the breakdown of the terminal actin web by several minutes. Under these conditions, the cadherin-catenin association within the adherens junction complex remained intact. We describe for the first time supramaximal CCK-dependent tyrosine phosphorylation of the adherens junction protein p120(ctn) and demonstrate the presence of an intact adherens junction protein complex in acinar cells. p120(ctn) may participate in the actin filament breakdown during experimental conditions mimicking pancreatitis.     

Distinct expression patterns of two zebrafish homologues of the human APP gene during embryonic development

The human amyloid protein precursor (APP) gene correlates with early onset of Alzheimer's disease in humans. We have identified two APP homologues in zebrafish, which we call appa and appb. They show a high degree of identity to human APP particularly in the beta APP42 and the transmembrane domain. Widespread expression of both appa and appb was detected from mid-gastrulation until the bud stage. During segmentation, the two genes diverged in their pattern of expression: at 14 h post-fertilisation (hpf) and 18 hpf both genes were expressed rostrally in the prospective CNS, but only appa was found caudally in the paraxial segmental plate and presomitic mesoderm, excluding the midline. In contrast, appb was found caudally in the neural rod at 14 hpf and the developing spinal cord at 18 hpf. Later, at 24 hpf both genes shared common expression domains, namely the telencephalon, the ventral diencephalon, the trigeminal ganglia, and the posterior lateral line ganglia. Unique expression domains for appa were the lens, the otic vesicles and the somites, while appb was expressed in a serially repeated set of nuclei within the hindbrain, the ventral mesencephalon and the motoneurones of the developing spinal cord.     

On-farm experiments over 5 years in a grain maize/winter wheat rotation: effect of maize residue treatments on <Emphasis Type="Italic">Fusarium graminearum</Emphasis> infection and deoxynivalenol contamination in wheat

Over the course of 5 years, different maize residue treatments were conducted on 14 zero tillage on-farm sites in Switzerland to evaluate their effect on the development of Fusarium head blight (FHB) and the contamination with the mycotoxin deoxynivalenol (DON) in winter wheat grains and wheat straw following grain maize. Two experimental series with three and five different treatments were carried out, respectively. Fusarium graminearum (Schwabe) was the predominant FHB-causing species with an overall incidence of 15% infected wheat grains. A significant correlation between symptoms in the field, F. graminearum incidence and DON content in wheat grains and wheat straw was observed. The average DON content in both wheat grains and wheat straw was approximately 5,000 μg/kg and thus several times higher than the European maximum limit of 1,250 μg/kg for unprocessed small-grain cereals for human consumption. Of all grain samples, 74% were above the maximum limit. Pooled over both experimental series, the average reduction of DON in grains through treatments of the maize residue compared with a control treatment ranged between 21 and 38%. The effect of various other factors, including the year, the wheat variety, the site, the maize hybrid and the production system was evaluated as well. The year and the wheat variety were the most important FHB influencing factors. Over all treatments, the variety Levis showed a fivefold higher average DON content compared with the variety Titlis. From different categories of maize residue particles, intact pieces of 5–15 cm length were strongly correlated with F. graminearum incidence and DON content in grains. During the time course of this study, the recommendation from a preliminary version of the internet-based DON forecasting system FusaProg to apply or to omit a fungicide treatment was correct in 32 out of 42 cases. The results are currently being used to optimise the FusaProg models. This study has shown that in a grain maize/winter wheat rotation, the DON content in wheat grains frequently exceeded the European maximum limit, even with a thorough treatment of maize residues and less susceptible wheat varieties. Hence, in order to reduce the contamination risk in a zero tillage system, the crop rotation needs to be modified.     

Genetic Diversity and Chemical Polymorphism of Some Thymus Species

To ascertain whether there are chemical and genetic relationships among some Thymus species and also to determine correlation between these two sets of data, the essential‐oil composition and genetic variability of six populations of Thymus including: T. daenensis ?elak. (two populations), T. fallax Fisch . & C.A.Mey ., T. fedtschenkoi Ronniger , T. migricus Klokov & Des .‐Shost ., and T. vulgaris L. were analyzed by GC and GC/MS, and also by randomly amplified polymorphic DNA (RAPD). Thus, 27 individuals were analyzed using 16 RAPD primers, which generated 264 polymorphic scorable bands and volatiles isolated by distillation extraction were subjected to GC and GC/MS analyses. The yields of oils ranged from 2.1 to 3.8% (v/w), and 34 components were identified, amounting to a total percentage of 97.8–99.9%. RAPD Markers allowed a perfect distinction between the different species based on their distinctive genetic background. However, they did not show identical clustering with the volatile‐oil profiles.     

Analysis of coronary angiography related psychophysiological responses

Background

Numerous studies have been conducted regarding a heartbeat classification algorithm over the past several decades. However, many algorithms have also been studied to acquire robust performance, as biosignals have a large amount of variation among individuals. Various methods have been proposed to reduce the differences coming from personal characteristics, but these expand the differences caused by arrhythmia.

Methods

In this paper, an arrhythmia classification algorithm using a dedicated wavelet adapted to individual subjects is proposed. We reduced the performance variation using dedicated wavelets, as in the ECG morphologies of the subjects. The proposed algorithm utilizes morphological filtering and a continuous wavelet transform with a dedicated wavelet. A principal component analysis and linear discriminant analysis were utilized to compress the morphological data transformed by the dedicated wavelets. An extreme learning machine was used as a classifier in the proposed algorithm.

Results

A performance evaluation was conducted with the MIT-BIH arrhythmia database. The results showed a high sensitivity of 97.51%, specificity of 85.07%, accuracy of 97.94%, and a positive predictive value of 97.26%.

Conclusions

The proposed algorithm achieves better accuracy than other state-of-the-art algorithms with no intrasubject between the training and evaluation datasets. And it significantly reduces the amount of intervention needed by physicians.